1
compact memories have flexible capacities  a digital data storage
system with capacity up to bits and random and or sequential access
is described
   /
2
an electronic analogue computer for solving systems of linear equations
mathematical derivation of the operating principle and stability
conditions for a computer consisting of amplifiers
   /
3
electronic coordinate transformer  circuit details are given for
the construction of an electronic calculating unit which enables
the polar coordinates of a vector modulus and cosine or sine of the
argument to be derived from those of a rectangular system of axes
   /
4
the british computer society  report of a conference held in cambridge
june
   /
5
millimicrosecond digital computer logic  a system of fast pulse
logic is described which combines the efficiency of transformer coupled
stages with digit delay tolerances approaching that of dc coupled
systems  logical circuits for or and inverter and reclock are shown
together with a driver which permits a fan out factor of  transistor
circuits are used through
   /
6
binary circuits count backwards or forwards  a transistorized module
is described that can be used to build logical circuits  a complete
reversible counter measures
   /
7
d packaging reduces size of electronic units  greater component densities
are obtainable using a module technique in which miniature circuit
elements are placed side by side with electrical connection mace on
a three dimensional basis by a spotwelding process
   /
8
the square loop ferrite core as a circuit element  the shape of the
output waveforms when the cores are switched is explained by a quantitative
theory which takes into account the residual loss reasonable
agreement with experimental evidence is shown
   /
9
switching circuits using bidirectional nonlinear impedances  a general
review of circuit logic is developed for a bidirectional nonlinear
switching element  the design of pnp transistor driver sriver stages
is considered  a binary octal decoder circuit and a simple binary
full adder circuit are discussed as examples
   /
10
highspeed microwave switching of semiconductors part
   /
11
design of bistable switching circuits using junction transistors
the relations between the different parameters which affect the switching
circuit may be obtained by plotting on the same diagram a load
line and the theoretical curve of the static characteristic of the
circuit
   /
12
perturbation of waveguides and cavities by spheres and cylinders
   /
13
on the theory of the cavity resonator comprising two confocal paraboloids
of revolution  a solution is found for a system of equations given
by buchholz
   /
14
the excitation of cavity resonators by secondary electron resonance
multiplication  experimental investigation of the suitability for
frequency multiplication of the process analysed in below
   /
15
some generalizations of duhamels integral for quadripoles
   /
16
the stable and unstable image parameters in quadripole theory  the
definition of stable and unstable image impedances by edldtkeller
is extended to related parameters and their position in the complex
plane is determined
   /
17
matching quadripoles  design formulae are derived for ii andt sections
and groups of curves are given from which practical design parameters
can be obtained
   /
18
optimum tchebycheff third order filters  a theoretical analysis is
given of a design for the detection of rectangular pulsed signals
on a background of white noise and it is shown that resulting signal
noise ratios are smaller than those obtained by the use of optimum
butterworth filters
   /
19
cascade directional filter
   /
20
transient response of bandpass filters to modulated signals  laurents
low pass band transformation is used with suitable approximations
to obtain the response to a suddenly applied carrier the derived
filter is analysed
   /
21
the order of complexity of electrical networks  an expression for
the order i  e  the number of natural frequencies is derived for
a rlc network  complete sets of dynamically independent network variables
are obtained from the network equations
   /
22
the stability criteria for linear systems  the various criteria can
be obtained and interrelated by means of continued fractions  the
hurwitz determinants are condensed to about half thei original order
   /
23
the efficiency of a ferrite as a microwave mixer  it is shown theoretically
that a polycrystalline ferrite should behave like a single crystal
sample  magnetization measurements taken previously are explained
by assuming a basic permeability line width of a few gauss and a spread
in resonant fields from point to point  the efficiency appears to
be lower than for a conventional crystal mixer
   /
24
selective properties of an oscillator system synchronized by a harmonic
signal  theoretical investigation of the dependence of the amplitude
and phase oscillations of an oscillator on the interference of a quasiharmonic
e  m  f  the effect on the system of harmonic and fluctuation
noise is briefly examined
   /
25
on the amplitude fluctuation of oscillations of a selfexcited vale
oscillator  mathematical analysis of the amplitude fluctuations of
an oscillator due to thermal noise and shot effect for the case of
weak and strong modes of excitation
   /
26
short time stability of a quartz crystal oscillator as measured with
an ammonia maser  appreciable improvement in the short time stability
is achieved by immersing the crystal in liquid helium  control of
the pressure of the gas above the liquid improves the long time stability
though adversely affecting the short time stability
   /
27
the reactance characteristics of concentric line circuits with interrupted
inner conductor  oscillator circuits in which the inner conductor
is interrupted e  g  those comprising diskseal valves are investigated
to determine the reactance as a function of gap and line section lengths
normally the higher resonant frequencies of the circuit are not harmonics
of the fundamental frequency
   /
28
application of delayed feedback in electronic circuits  a short general
theory is given of a method of generating periodic signals of controlled shape
two simple applications of a delay line aa feedback loop
are given  the signal frequency depends on the delay time and under
certain conditions on the triggering frequency and this provides a method
measuring the delay time of an element in the feedback loop
   /
29
use of relaxation oscillators in the generation of frequency modulated
oscillations  an analysis of the operation of a relaxation oscillator
as a frequency modulator with a series of diode circuits for transformation
of the triangular waveform into sinusoidal form
   /
30
millimicrosecond pulse generator capable of million pulses per second
the generator has a repetition rate of up to sec pulse rise time
less than and pulse widths from to  the negative output pulse is
adjustable over a range of to into a load  there are facilities for
gating single pulses and triggering from an outside source
   /
31
electronic probability generator  description of a random pulse generator
simulating the tossing of a coin times per second  the probability
of a particular side of the coin can be varied
   /
32
on the problem of starting conditions of the avalanche process in
relaxation oscillators on poinoscillators on point contact triodes
it is shown that the oscillators can be considered as nonlinear voltage
or current amplifiers  conditions governing the formation of the
avalanche process are given and fomulae are derived for coefficients
of voltage and current amplification  circuits are shown
   /
33
frequency divider with direct locking  investigation is carried out
by the phase pulse method  the effect of phase shift in the feedback
circuit  nd of anode reaction on the divider regime is considered
the effect of the shape of the synchronized and pedestal pulses on
the divider is also examined  theoretical data are verified by experimental
results
   /
34
generations of harmonics and subharmonics at microwave frequencies
with pn junction diodes  the performances of a nonlinear resistance
and a nonlinear capacitance in a wideband harmonic generator circuit
are analysed  the nonlinear capacitance is shown to have a considerably
higher efficiency  results of experiments with a graded junction si
nonlinear capacitance diode are given
   /
35
a new microwave harmonic generator  microwave power is used to maintain
a very short mercury arc between a pool cathode and a tungsten wire
anode  with an estimated input power of a few watts at kmcs an output
in excess of mw was obtained at kmcs a strong signal at kmcs was
detected by a spectrum analyser placed close to the arc tube
   /
36
improved diode for the harmonic generation of millimetre and submillimetre
waves
   /
37
the stability factor and static gain of transistor amplifiers  a
general method relating the stability factor of disturbances of thermal
origin to static gain is described
   /
38
use of the silicon resistor in the d  c stabilization of transistor
circuits  stabilization of ground emitter small signal stages over
a wide range of temperatures is achieved with a si resistor of high
positive temperature coefficient in the emitter circuit
   /
39
local feedback in transistor amplifiers  the effects of negative
feedback on common emitter amplifiers are calculated and compared
with the measured results
   /
40
proposal for a tunable millimetrewave molecular oscillator and amplifier
   /
41
the molecular amplifier  the principles of molecular amplification
and the main characteristics of the various types of maser are reviewed
   /
42
theory of maser oscillation  the experimentally observed amplitude modulated
nature of the signal from an inverted spin system undergoing
maser oscillation or coherent spontaneous emission is explained
   /
43
silvered ruby maser cavity  preparation and properties are described
   /
44
noise figure of reactance converters and parametric amplifiers  a
simple derivation of noise figure correcting a formula of heffner
wade
   /
45
phase considerations in degenerate parametric amplifier circuits
a theoretical examination of the negative resistance in the signalling
circuit as a function of the phase angle between the pump and signal
voltages
   /
46
selfquenching in superregenerative parametric amplifiers  a qualitative
reasoning of the behaviour of cavity time parametric amplifiers in
the u  h  f  range using ge diodes is given for the condition of
selfbias or external bias with high internal resistance applied to
the diode  increase in pump power makes frequency response multipeaked
as with regenerative valve amplifiers in the coherent state
   /
47
use of the principles of conservation of energy and momentum in connection
with the operation of wavetype parametric amplifiers  some limitations on
operation are explained in simple terms and certain general
relations governing behaviour including the manleyrowe relation are
derived
   /
48
the quadrupole amplifier a low noise parametric device
   /
49
analysis of a negative conductance amplifier operated with a non deal
circulator
   /
50
the gain of travelling wave ferromagnetic amplifiers  the gain of
an amplifier using a circular waveguide and axial ferrite rod of
small cross section is determined by a general perturbation method
methods for overcoming the low efficiency are discussed and other
possible waveguide configurations and practical aspects of construction
are described
   /
51
two maser experiments to test general relativity  a comparison of
the velocities of light in two directions can be made to an accuracy
within using maser techniques  the two experiments involve such comparisons
to test the principle of equivalence and the local isotropy of
the spacet me continuum respectively
   /
52
a model of phosphors on the basis of quantum mechanics transition
probabilities with constant defects and a discrete spectrum
   /
53
the quantum mechanical theory of the dielectric orientation polarization
of gases the orientation of a dipolar gas consisting of symmetric
spin molecules in an attenuating electric field
   /
54
influence of the thomson effect on the relationship for a constrictive
resistance in thermal equilibrium
   /
55
investigation of a highfrequency resonant discharge  an experimental
study of a discharge in a magnetic field in the frequency range
a theoretical and experimental analysis is made of the breakdown
conditions and characteristics and the properties of the plasma in
the discharge
   /
56
the application of schottkys diffusion theory to discharges with several
types of ions and excited neutral particles
   /
57
the low pressure plane symmetric discharge
   /
58
pulse technique for probe measurements in gas discharges
   /
59
frequency multiplication by secondary electrons in the centimetre wavelength
range  fourier analysis of the electron current produced by secondary electron
resonance multiplication shows that many harmonics are
generated so that the process appears suitable for frequency multiplication
in the cm range
   /
60
theory of spatially growing plasma waves
   /
61
on the growth of longitudinal waves propagating in plasma  an analytical
treatment based on a single solution of the one dimensional linear
kinetic equation describing the propagation of highfrequency signals
produced by a given external force  it is shown that for a low temperature
of the electron gas it is possible to use the ordinary single velocity
approximation  the analysis of the results permits a determination
of the direction of propagation of natural waves in a plasma and a
solution of the problem of the existence of increasing waves in a
rectilinear electron beam
   /
62
anomalous skin effect in ferromagnetics  a brief mathematical analysis
of the anomalous skin effect which is present in ferromagnetic materials
at resonance at low temperature and at high frequencies when the depth
of the skin layer is of the order of the length of a free path of
the conduction electrons
   /
63
on the singular electromagnetic field in the borniefeld theory  it
is shown thet for this singular case the borniefeld theory gives
the same results as maxwells theory
   /
64
simple derivation of sommerfelds formula for the dipole function
   /
65
transmission and reflection by a parallel wire grid  experimental
results are given for the transmission and reflection coefficients
of a plane grid of parallel wires at frequencies near kmcs  the results
are compared with theory
   /
66
diffraction by a slit  several methods of calculation of the aperture
field are compared
   /
67
diffraction of electromagnetic waves by smooth obstacles for grazing
angles  the diffraction of electromagnetic waves by a convex cylindrical
suface is considered  attention is confined primarily to the region
near the lightshadow boundary  the complex integral representation
for the field is utilized to obtain a correction to the kirchhoff
theory  numerical results are presented which illustrate the influence
of surface curvature and polarization on the diffraction pattern
good agreement with the experimental results of bachynski neugebauer
is obtained  the effect of finite conductivity is also considered
   /
68
the scattering of electronmagnetic waves by a corrugated sheet  the
physical optics method is used to determine the scattering of a plane
wave by a perfectly conducting sheet having sunusoidal corrugations
   /
69
microwave conductivity of slightly ionized air  values computed from
experimental data are compared with others derived from simple formulae
   /
70
cavity resonators for dielectric spectroscopy of compressed gases
tunable sealed off resonators for frequencies and kmcs at pressures
are described
   /
71
dispersion measurements on nacl kcl and kbr between and mm wavelength
report of tests made with the spectrometer described in below
   /
72
a grating spectrometer for the far infrared range and short microwaves
a special diffraction grating is incorporated in the equipment described
which covers the wavelength range mm  for measurements blow mm the
source is a mercury vapour lamp above mm a klystron with frequency
multiplier is used
   /
73
negative and oscillatory longitudinal magnetoresistance  a report
on the result of numerical calculations of semiconductors and semimetals
for the case in which electron scattering is due to the acoustic
modes of the lattice vibrations and the magnetic field is so large
that the quantization of the electron orbit is important
   /
74
methods of improving the stability in devices based on the hall effect
the investigation shows that the main reasons for the temperature
instability in these devices are the inhomogeneity of the crystal
lattices of the sample the rectification and the insufficient equipotentiality
of the hall contacts
   /
75
a comparison of the charges of the electron proton and neutron  a
report of experiments to determine whether matter in which there
is an excess of neutrons is electrically neutral  for a comment by
h bondi r a lyttleton see sept vol supplement
   /
76
measurement of cosmic noise at low frequencies above the ionosphere
a description of the basic design features of a mcs frequency sweep
radiometer  the equipment is to be launched as an artificial satellite
for the measurement of cosmic noise
   /
77
solar investigations in japan  a description of interferometric investigations
carried out during teh igy by tokio observatory in the range
mcs of the intensity distribution over the solar disk  the radio
noise on mcs seems to originate in the solar atmosphere km above
the visible solar surface  recordings of radio noise between mcs
are shown and the relations of solar flares magnetic storms and radiowave
attenuation are considered
   /
78
observations of the fine structure of enhanced solar radio radiation
with a narrow band spectrum analyser  an extension of the work described
earlier
   /
79
association of radio outbursts with solar flares  data covering the
period july december have been examined for a relation between rf
bursts and flares  a greater than normal percentage of impulsive flares
of importance were accompanied by rf bursts
   /
80
distribution of flares on the solar disk associated with noise  results
for periods between june and july indicate that present conditions
in the solar corona favour noise emission at vhf from flares occurring
in the northwest quadrant of the solar disk
   /
81
eclipse observations of microwave radio sources on the solar disk
on april  results are given of observations of flux density polarization
and brightness distribution made in japan four frequencies in the
range
   /
82
on the relation of solar eruptions to geomagnetic and ionospheric
disturbances  a statistical analysis of data indicates that the characteristics
of solar rf bursts can be related to s type storms shortwave
fades or a combination of both types of disturbance
   /
83
red shift absorption spectrum of the cygnusa radiosource  results do
not confirm the observations of lilley mcclain
   /
84
terrestrial corpuscular radiation  a note on the two van allen zones
which are attributed to charged particles moving in closed trajectories
formed by magnetic traps due to the earths magnetic field  a graph
based on american and russian rocket data shows the variation of
the intensity of these zones with height  a maximum intensity is
recorded at a distance between km from the centre of the earth
   /
85
fermi acceleration of electrons in the outer van allen belt
   /
86
the physical nature of the surface of the moon  evidence concerning
the structure of the lunar rock is reviewed  it is probable that
it is vesicular in nature
   /
87
apparent observation of solar corpuscular clouds by direct continuous wave
reflexion  a report of observations in ohio of doppler signals centred
on mcs which were first recorded at ut on april  the observations
are discussed in relation to a solar flare of importance which reached
a maximum at about ut on april
   /
88
kellogg and neys model of the solar corona  critical comment on of
and authors reply
   /
89
some results obtained by measuring the magnetic field at the earth
with a space rocket  results obtained using magnetometers with a
range of and a telemetry channel sensitivity of v where oersted indicate
that at a distance of earth radii the magnetic field does not depend
only on the earthpotential but also on external sources such as charged
solar particles  measured values recorded by space rocket are lower
than calculated ones  the difference between these values reaches
a maximum at km and a minimum at km
   /
90
the analytical representation of the geomagnetic field  the representation
of the geomagnetic field for the epoch by series of spherical
functions up to order are discussed  within the limits of accuracy
reached the permanent geomagnetic field may be derived only with
respect to sources within the earth
   /
91
on the characteristic intervals of pulsations of diminishing periods
in the electromagnetic field of the earth and their connection with
phenomena in the upper atmosphere  investigation by highspeed recording
of the daily variation of the earths em field has shown that during
strong magnetic storms characteristic intervals of pulsation occur
the decreasing period of these pulsations can be directly correlated
with the sharp atmospheric disturbances and the development of aurora in
lower latitudes  records obtained during two severe magnetic storms
in are discussed
   /
92
evidence concerning instabilities of the distant geomagnetic field
pioneer i  a report of some preliminary observations suggesting directional
instability in the field
   /
93
measurement of the rapid fluctuations of the earths magnetic field
a ferroxcube probe in circuit with a photoelectric fluxmeter of sauzade
may be used to observe fluctuations at frequencies up to cs
   /
94
geomagnetic storms and the earths outer atmosphere  re  hydromagnetic
oscillations of the ionized outer atmosphere are considered theoretically
and discussed in relation to observations of geomagnetic pulsations
the geomagnetic storm on february is analysed in terms of hydromagnetic
disturbances in the outer atmosphere  during such storms a corpuscular
cavity earth radii in size is formed enclosing the earths magnetic
field  a model of the interplanetary space is proposed  references
   /
95
on the electric field of the polar magnetic storm  it is suggested
that proton and electron streams rushing into the ionosphere have
a common powerful polarized field between them which might give rise
to the currents associated with polar magnetic storms
   /
96
the laws of motion of artificial celestial bodies  the critical velocities
of artificial satellites are discussed and the observed trajectory
of the first cosmic rocket launched on the january is examined  a
rocket designed to reach the moonmust have an initial velocity of
approximately ms
   /
97
an application of dynamic programming to the determination of optimal
satellite trajectories
   /
98
orbits of artificial satellites  orbits are specified by three nondimensional
parameters at rocket burnout and expressions giving the periods
of closed orbits in terms of the parameters are derived
   /
99
the continued progress of satellite sputnik  report of the progress
of the satellite since november and of the methods used for predicting
its flight at the radio research station slough  earlier progress
has been reviewed by kinghele
   /
100
satellite observations of electrons artificially injected into the
geomagnetic field  the geomagnetically trapped electrons resulting
from the high altitude nuclear detonations of the argus experiment
have been observed on four radiation detectors in satellite explorer
the measurements for several satellite passes through the argus shells
are described and the significance of the results is summarized
   /
101
mass spectrometer measurements of the ionic composition of the atmosphere
by the third artificial earth satellite  discussion of results
obtained from an analysis of mass spectrograms taken between the
may at heights of km in the latitude interval  graphs show the variations
of relative ionic intensity as a function of height and latitude
above km molecular ions are on longer observed
   /
102
the faraday fading of radio waves from an artificial satellite  faraday
fading of signals from an artificial satellite is analysed in terms
of the difference between the doppler shifts of the ordinary and
extraordinary components in the ionosphere  a procedure is outlined
for determining the vertical distribution of electron density in the
upper ionosphere  explanations are given forthe apparently excessive
values of electron content yielded by measurements of faraday fading
and for the observation that the rate of faraday fading is not exactly
inversely proportional to the square of the wave frequency
   /
103
radio detection of silent satellites  t brief description of the
characteristics of reflected signals from a standard frequency transmitter
within the skin distance received on mcs  see also ofkraus dreese
   /
104
diurnal and semidiurnal variations of wind pressure and temperature
in the troposphere at washington dc
   /
105
turbulence at meteor heights  an outline of a new method of studying
motions at meteor heights by assuming that they are perturbations
associated with oscillating waves propagated through the atmosphere
   /
106
study of the new model of the ionosphere  the variation with height
of the electron density is calculated for three cases and good agreement
is obtained between the model and the results of moon echo observations
   /
107
effect of small irregularities on the constitutive relations for
the ionosphere  a theoretical treatment of the modification of refractive
index due to small irregularities  the latter may play an important
part in the propagation of vlf radio waves
   /
108
stratification in the lower ionosphere  a survey of the evidence for
stratification at heights below km  over references
   /
109
electron collision frequencies in nitrogen and in the lower ionosphere
by using an improved version of the electron drift velocity tube in
the laboratory measurements and an improved analysis of rocket data
the two sets of results are brought into agreement  reevaluation
of the rocket data involves the energy dependence of the electron
collision frequency
   /
110
the possible occurrence of negative nitrogen ions in the atmosphere
if negative ions are formed and laboratory experiments show that they
may be a strong pressure dependence of the electron ion recombination
coefficient is to be expected  at the very low f region pressures
the rate of disappearance of free electrons could follow an attachment
law
   /
111
tides in the f ionospheric layer  a brief report of the results of
a harmonic analysis of the mean diurnal variation of the layer semithickness
during the period at leopoldvillebinza belgian congo
   /
112
a theory of spread f based on a scattering screen mod  oblique rays
from the sounder are scattered by a scattering screen into the f
region whence they are reflected back to the sounder  for frequencies
appreciably higher than the f region penetration frequency there
is a linear relation between the minimum virtual height of the returned
signal and the operating frequency  all virtual heights above this
minimum value and below the normal vertical incidence value are possible
this fact accounts for spread echoes being enclosed by two sharp
defined boundaries  this hypothetical picture agrees with that obtained
from actual ionograms but requires that the screen be above e region
heights
   /
113
magnetic control of the variations of the critical frequency of the
f layer of the ionosphere  the true magnetic latitude reference is
shown to give more satisfactory results than the idealized geomagnetic
latitude reference when considering diurnal and latitudinal variations
of f at low latitudes
   /
114
measurement of ionospheric electron densities using an rf probe technique
the probe consists of a dipole operating at mcs and has been flown
in a rocket over fort churchill  above km it behaves as a capacitor
the capacitance of which is telemetered to the ground  the local
electron density in the ionosphere may be calculated from these values
by using a simplified form of the appleton hartree equation  the electron
densities obtained using such probes are in good agreement with
those obtained by normal methods
   /
115
investigation of winds and inhomogeneities in the ionosphere using
a radioastronomy method  description of measurements made using three
parabolic meshtype reflectors of area spaced approximately apart
and operating at a wavelength of m  ionospheric wind velocities
of ms were recorded
   /
116
ionospheric investigations using the sweep frequency pulse technique
at oblique incidence  a review of oblique incidence investigations
especially those carried out at the national bureau of standards
showing diurnal and seasonal variations on two eastwest paths of
km and km  there is a discrepancy of about between the observed and
calculated muf
   /
117
the d region of the ionosphere
   /
118
the argus experiment  a geophysical experiment on global scale was
conducted last fall  three small abombs were detonated beyond the
atmosphere at a location in the south atlantic  the purpose of the
experiment was to study the trapping of the relativistic electrons
produced by the decay fission fragments in the geomagnetic field
the released electrons are trapped by this field oscillating along
the magnetic lines between two mirror points  in addition to this
motion the electrons drift eastward creating a thin electron shell
around the earth  the lifetime and location of the thus created global
electron shell were measured by satellite and rocket borne instruments
auroral luminescence was observed at the conjugate points  the electron
shell exhibited remarkable stability during its lifetime  no motion
of the shell or change in its thickness was detected
   /
119
optical electromagnetic and satellite observations of high altitude
nuclear detonations part  after each of the high altitude detonations
in the argus experiment visual auroras were observed in the detonation
area  after the third event an aurora was observed in the conjugate
area  after the second and third events signals attributed to hydromagnetic
waves were detected in the conjugate region these signals had
a periodicity of about cs  the maximum change in the magnetic field
was about gamma  io propagated along the magnetic line of force the
velocity was about km sec  sporadic e was observed after the third
event in the conjugate area  comparative records of the and lines
were obtained in the detonation area
   /
120
optical electromagnetic and satellite observations of high altitude
nuclear detonations part  the radio effects of the argus detonations
were measured using mcs radars designed to obtain echoes from the
aurora or from the earths surface mirrored in an enhanced ionospheric
layer vlf receivers for monitoring distant transmitters or atmospheric
noise sources in search of changes in signal strength riometers for
recording cosmic noise absorption or vhf shot created noise at and
mcs  results included auroral echoes in the vicinity of the launch
point after all three shots and near the conjugate points after the
first and th d shot sudden depressions of to db of the signal from
england at madrid and the azores no ionospheric absorption at the
conjugate location
   /
121
project jason measurement of trapped electrons from a nuclear device
by sounding rockets  highaltitude sounding rockets have been used
to observe electrons injected into the geomagnetic field from the
highaltitude nuclear detonations of the argus experiment  the results
of these observations agree with those measured by satellite explorer
the trapping of neutron decay particles from large yield highaltitude
explosions in the pacific was also observed
   /
122
theory of geomagnetically trapped electrons from an artificial source
the history of electrons resulting from the highaltitude nuclear
detonations of the argus experiment is treated theoretically and
the results are compared with the jason rocket data and the explorer
satellite data
   /
123
modern theories of thunderstorm electrification  critical comparison
of theories eg of wilson  suggestions are made for investigations
to determine the correctness of convection theories  references
   /
124
very low frequency radiation spectra of lightning discharges  an analysis
is given of the ground wave portion of sferics waveforms recorded
from cloud to ground discharges between and km from boulder colorado
frequencies of peak energy lie between and kcs
   /
125
diurnal variation of aurora and geomagnetic disturbance at new zealand
antarctic stations  a relation exists between aurora and geomagnetic
disturbance but the main features of diurnal variation of auroral
incidence are not related to local geomagnetic variations
   /
126
low frequency radio noise from the aurora  strong rf noise recorded
on one occasion at frequencies up to kcs is reported
   /
127
auroras magnetic bays and protons  observational evidence indicates
that aurorae and magnetic bays both have the same cause and occur
at the same geographic location  calculations show that these bays
can be explained by a wind movement of positive ions generated by
incoming solar protons
   /
128
observations of whistlers and very low frequency phenomena at godhavn
greenland
   /
129
a digital remote position control  a description of a servo shaft position
control system using digital techniques throughout  the logical circuit arrangements
and methods of stabilizing are discussed together with
the design procedure
   /
130
inverse feedback stabilizes drycell current sources  a transistor
emitter follower circuit enables constant heavy currents to be drawn
from dry cells despite variations in cell voltage
   /
131
power supply design using silicon diodes
   /
132
constant current coup transistor power supply  by feeding a constant
current through a fixed resistor across the supply output an unattenuated
error voltage can be applied to the error correcting amplifier
of a series regulated power supply
   /
133
designing highly stable transistor power supplies  design techniques
are summarized and a circuit is described with overall stability
and drift
   /
134
transistors and saturable core transformers as square wave oscillators
the use of transistors as switches for the dc supply to saturable
core transformers is described and it is shown that by this means
small and efficient convertors and invertors can be constructed
the common base common emitter and common collector configurations
are considered and methods of obtaining a multiphase output are described
   /
135
a method of reducing the time lag of transducers which have an exponential
response  the response of a transducer such as a thermocouple is
corrected for phase and amplitude by adding its output voltage to
its amplified derivative  details of a drift corrected dc amplifier
and highly stable power supply are given
   /
136
the stabilization of dc voltages by switched transistors  stabilizing
circuits are discussed in which transistors function as continuous control
devices or as switches driven by a schmitt trigger circuit  comparison
is also made with a transistor switched rectifier circuit
   /
137
method of amplitude control of ac signals  a circuit for controlling
the rms value of an ac signal is analysed and practical results are
discussed  the speed of response is such that for rates of change
of per second the output is controlled continuously within  an alternative
arrangement for maintaining at a preset level the peak value of repetitive
pulses is also given
   /
138
zener diodes as reference sources in transistor regulated power supplies
a summary of the relevant properties of zener diodes including
a figure of merit representing the maximum value by which supply
variation may be reduced  methods for controlling the overall temperature
coefficient are considered
   /
139
ammonia vapour activated batteries
   /
140
the simulation of equations with analogue computers  detailed description
of the principles of operation of the various computer elements
giving examples of programming and computation with reference to
an american electronic analogue computer
   /
141
some aspects of the logical and circuit design of a digital field
computer  a new type of digital computer for the solution of field
problems is described  by making calculations at all the lattice
points of the field simultaneously computation time is greatly reduced
an experimental design of a basic unit for potential and other problems
is presented
   /
142
the a c writing method for magnetic core matrices  description of
a writing method suitable for operation in a system using parametron
devices  two alternating currents of frequency respectively produce
an asymmetrical field in a toroidal core  one of the writing currents
is also used for reading
   /
143
function generation with operational amplifiers errors in analogue
computers caused by diode limiters can be reduced by using accurate
electronic switches with high gain d c amplifiers and voltage feedback
applications of the techniques for comparators multivibrators and
integrator reset circuits are described and future applications are
indicated
   /
144
reading of recorded signals with a low frequency parametron  description
of a tape recording system in which parametron devices replace valves
to increase the storage capacity some form of multiplex system is
required
   /
145
high density recording on magnetic tape  a self clocking technique
is used to bypass problems of digital recording at a density of
bits  high reliability is obtained with no information drop out
   /
146
the application of a pattern recognition technique to the synthesis
of coding circuits  if the coding processes considered are regular
and predictable then corresponding translating circuits can be determined
to illustrate the technique a pattern recognition method is applied
to two coding problems
   /
147
the synthesis of a parallel adder circuit using a pattern recognition
technique  besides the synthesis a comparison with a conventional
adder circuit is given
   /
148
lens designing by electronic digital computer  a description of the
program used and the results achieved
   /
149
miniaturization and microminiaturizatio  description of new techniques
giving increased reliability together with a preliminary evaluation
of their performance compared with existing techniques
   /
150
signal converter by magnetic cores for parametron device  input signals
for a parametron device may be switched using ferromagnetic cores
whose permeability is controlled by direct voltage
   /
151
transistor switching speed  theoretical treatment of the limitations
of transistors in high speed switches together with some methods
of improving performance by decreasing switching time
   /
152
the breakdown strength of capacitors  a formula for breakdown field
strength is derived which contains the coefficient of thermal conductivity
the dielectric constant and a factor giving carrier mobility
   /
153
the temperature and voltage dependence of the length of life of capacitors
the process of deterioration of the dielectric material under
various operating conditions is discussed on a theoretical basis
and with reference to life tests on paper capacitors
   /
154
contribution to the theory of general quadripoles  the matrix characteristics
of general linear quadripoles are investigated and a strict
definition of a lossless quadripole is given  an equivalent circuit
of the quadripole formed by three partial quadripoles connected in
tandem is derived matching problems and a formula for power gain
are discussed
   /
155
design of attenuators of given characteristics  design formulae for
quadripole attenuating networks are tabulated
   /
156
a reciprocal theorem on quasilinear wave filters  under certain conditions
the power of an intermodulation product measured at one pair
of terminals of a filter equals that measured at the other pair when
all signals are transmitted in the opposite direction but at unchanged
levels
   /
157
electromechanical filters for use in telecommunication equipment
includes descriptions of construction and performance of reed type
magnetostrictive and piezoelectric filters
   /
158
a practical electromechanical filter  details of materials and fabrication
techniques are given for narrow band torsional filters
   /
159
a theoretical analysis of the torsional electromechanical filters
the mechanical properties of a torsional system are expressed in
terms of electrical equivalents  by introducing a transducer transfer
ratio with the dimensions of charge a method is developed for the
design of electromechanical filters based on equivalent electrical
networks  pass band ripple spurious modes and transducer matching
are discussed
   /
160
digital input for precision variable oscillators  details are given
of a signal generator for the frequency range  the drive unit is
a voltage controlled oscillator regulated by the difference in width
between standard pulses and pulses whose duration is that of the
time required for the oscillations fed to a counter unit to equal
a preset number
   /
161
a method of generating pairs of millimicrosecond current pulses separated
by a variable interval  the first pulse is formed by the discharge
of a coaxial line l through a spark gap into a variable length section
of identical line  a second pulse is produced by the return of the
first pulse after reflection at the short circuited end
further reflections from the
other end of l are prevented by a clipping valve
   /
162
frequency stable oscillators for current and voltage  the suitability
of bridge type oscillators as current or voltage source under optimum
frequency stability conditions is discussed
   /
163
wien bridge oscillators  theoretical analysis of wien bridge oscillators
and procedure for practical design together with an example of thermistor
stabilization
   /
164
pulse modulators using transistors and switching reactors  a regenerative
circuit is described which uses a power transistor to control
the charging of a pulse forming network through a transformer with
a sharply saturating core
   /
165
point contact transistor relaxation oscillators  the plotting of
phase curves for oscillators with emitter collector and collector
capacitance are shown and possible operating modes investigated
expressions are given for deriving the pulse parameters  conditions
are expressed for the appearance of step discontinuities as well
as for a self oscillatory mode
   /
166
approximate waveform solutions for diodes in pulse circuits  with
an approximate representation of a diode solutions are obtained for
the response of simple circuits to a rectangular wave input  applications
of the results are discussed
   /
167
an investigation into some aspecst of diode quantizing circuits
quantization is defined and work in the field is reviewed  three
circuits are compared theoretically and by measurement and possible
applications are described
   /
168
harmonic generation in a cyclotron resonant plasma  the harmonic
conversion efficiencies are comparable to those for crystals and
over the same power range superior to those for ferrite multipliers
   /
169
a transistor blocking oscillator frequency divider  this includes
the design of a staircase waveform generator in which all the voltage
increments are equal in amplitude
   /
170
design of pulse amplifier  a relation between gain overshoot and
risetime is derived and applied in the design of a single stage valve
amplifier
   /
171
distortion in pentode voltage amplifiers  characteristics are given
which show that for a fixed screen voltage the distortion varies
rapidly with changes in grid bias whilst if the screen voltage is
supplied via a series resistance there is a compensating action which
maintains the distortion at an almost constant value
   /
172
rc amplifier with bandwidth  the effect of stray capacitance is compensated
by a cathode follower circuit
   /
173
cathode coupled push pull output stage  a theoretical investigation
of linear operation shows that for large common cathode resistances
the ratio of anode currents in each valve approximates to unity
   /
174
how magnetic amplifier controls transconductance
   /
175
transistor amplifiers for sound broadcasting  the application of
ge p n p junction transistors to various types of high quality amplifier
is described  an assessment is made of the suitability of transistors
for this field
   /
176
transistors in low frequency amplifiers  design formulae are derived
and the relations between circuit parameters for the three basic
transistor configurations are tabulated  the main types of feedback
and their effects are discussed
   /
177
possible low noise electron beam plasma amplifier
   /
178
cavity maser experiments using ruby at s band  a three level solid
state maser was used
   /
179
a double pumping scheme applicable to low frequency masers  note
on a parallel pumping system of importance for low frequency operation
of a ruby maser
   /
180
semiconductor varactors using surface space charge layers
   /
181
alloyed thin base diode capacitors for parametric amplification
the design principles are ghven
   /
182
electroluminescent cell applications  an account of investigations
of the combination of electro luminescent cells and photo receptors
as elements in amplifier oscillator demodulation amplifier and bistable
multivibrator circuits  measurements of the variation of efficiency
with frequency and a theoretical analysis of photoconductor amplifier
time constants are also ghven
   /
183
diode phase sensitive detectors with load  a theoretical and experimental
investigation of the nonlinearity introduced by loading a simple
diode pushpull phase detector
   /
184
new experimental test of special relativity
   /
185
two coordinate colour
   /
186
on the screening of impurity potential by conduction electrons  a
modified thomas fermi method is used to calculate the impurity potential
and it is shown that similar results are obtained by the method of
nakajima and bardeen and pines
   /
187
the effect of field configuration on gas discharge breakdown in microwave
cavities at low pressure  a new regime of gas discharge breakdown
in microwave cavities is shown to be due to gradients in the electric
field amplitude  experimental results are given
   /
188
necessary and sufficient trajectory conditions for dense electron
beams  gives conditions for flow in the direction of one coordinate
in a number of coordinate systems
   /
189
two alternative definitions of small signal r f power of electron
beams  lagrangian or eulerian definition is chosen according to the
type of problem or method of calculation
   /
190
comments on kluvers paper entitled small signal power conservation
theorem for irrotational electron beams
   /
191
measurement of plasma temperature and electron density
   /
192
electron and ion runaway in a fully ionized gas  hydrodynamic equations
are used to describe the flow of the electrons and ions of a fully
ionized gas under the action of an electric field of arbitrary magnitude
   /
193
ionization phenomena in gases  report of a conference at uppsala
sweden
   /
194
effect of relatively strong fields on the propagation of e m waves
through a hypersonically produced plasma
   /
195
possible low noise electron beam plasma amplifier  low noise amplification
of space charge waves should be achieved by interaction between
electron beam and plasma in the negative glow region of a cold cathode
discharge
   /
196
plasma configurations with surface currents which are held in equilibrium
by a magnetic field  the conditions for the existence of various
plasma configurations in equilibrium with an external magnetic field
are investigated
   /
197
remarks on magnetically dilute systems  a re examination of the problem
using an ising model
   /
198
a scalar representation of electro magnetic fields  ghves transformation
properties and the physical energy momentum tensor appropriate to
green and wolfs theory
   /
199
a scalar representation of electro magnetic fields  extens work in
an earlier paper to deal with energy transport
   /
200
diffraction of a dipole field by a unidirectionally conducting semi
infinite screen  an exact solution of the diffraction problem for
a dipole is obtained
   /
201
diffraction of electromagnetic waves in a band of finite width  brief
mathematical analysis based on a new method for solving integral
equations similar to the fredholm equations
   /
202
induced and spontaneous emission in a coherent field  the interaction
between the electromagnetic field and a number of identical atomic
systems individually characterized by an electric dipole moment and
tow energy levels is analysed for the case where the atomic systems
are inside a lossy cavity and exposed to a coherent driving field
resonance being assumed between atomic system cavity and driving
field
   /
203
square wave modulator and receiver for stark effect microwave spectrometers
   /
204
superexchange interaction and symmetry properties of electron orbitals
a search for neutral atomic hydrogen in globular clusters
   /
205
the relation of cosmic radio emission to the electronic component
of cosmic rays  the similarity between the spectra of cosmic rays
and of the relativistic electrons responsible for cosmic radio waves
suggests that the electrons may derive from the collisions of primary
cosmic rays with the interstellar gas  the relation to be expected
from this process is examined
   /
206
the brightness distribution within the radio sources cygnus a and
cassiopeia a
   /
207
the source of radiation from jupiter at decimetre wavelengths  electrons
from the sun which are trapped in jupiters magnetic field may be
the source
   /
208
radio emission in the outer corona
   /
209
correlation between the intensity of the umbra of sunspots and enhanced
radiation  from observations made in norway since april a high correlation
is shown to exist between the darkness of the umbra and noise
activity of sunspots
   /
210
geomagnetic disturbance and velocity of slow drift solar radio bursts
   /
211
a radio astronomical test of the ballistic theory of light emission
a comparison between optical and radio interferometer measurements
of the declination of radio star cygnus a is put forward as proof
that the ballistic theory of light emission is untenable
   /
212
on the possibility of detecting synchrotron radiation from electrons
in the van allen belts
   /
213
proton component of the primary cosmic radiation  the proton component
has been studied at high altitudes on a series of balloon flighst
at various latitudes using the cerenkov scintillation counter technique
results are discussed
   /
214
unusual cosmic ray fluctuations  a large forbush decrease of cosmic
ray intensity which coincided with a magnetic storm exhibited rapid
changes of neutron intensity  it is diffult to account for these
changes on the basis of existing theories of the modulation of cosmic
radiation
   /
215
radio echo observations of venus  a description of the equipment
used and a discussion of the results of observations at kodrell bank
no echoes stronger than the noise level of the receiver were observed
an analysis of the signals received was therefore made with integrating
equipment and the results compared with those of price et al
   /
216
the effect of trail irregularities on the interpretation of meteor
echoes  a brief discussion of some points raised in a recent paper
by manning on obliquely scattered meteor echoes is followed by the
suggestion that the initial distribution of ionization along a typical
meteor trail is markedly irregular  several tentative hypotheses
are advanced to account for the irregularities
   /
217
variations in the geomagnetic field at ibadan nigeria
   /
218
effects of the earths oblateness on the orbit of an artificial satellite
a mathematical analysis of the perturbations of the radius vector
the displacement of the nodal and apsidal lines and the variation
of the inclination with latitude  a rigorous solution to the second
order differential equation is given for an equatorial orbit taking
account of the first order effects of the earth oblateness  some
second order effects on the equatorial orbit and the relativistic
effect of the apsidal line displacement are considered
   /
219
density of the upper atmosphere from analysis of satellite orbits
further results  a method described earlier has been refined to take
into account atmospheric rotation
   /
220
the ion trap results in exploration of the upper atmosphere with
the help of the third soviet sputnik  the interpretation of the data
given b  krassovsky is queried and an analysis presented which leads
to lower values of vehicle potential and electron temperature
   /
221
unusual propagation of satellite signals
   /
222
multiplexing techniques for satellite applications
   /
223
radiosondes for measurements of atmospheric electricity  four types
of radiosonde are described
   /
224
the earth in the suns atmosphere  the extent nature and interrelation
of the solar and terrestrial atmospheres are considered
   /
225
solar activity and the altitude of the tropopause near the equator
   /
226
molecular oxygen densities in the mesosphere at fort churchill
   /
227
a contribution to the theory of the motion of weak irregularities
in the ionosphere  if diffusion is neglected any one dimensional
irregularity travels unchanged with a constant velocity which depends
on the magnitude and direction of the ionospheric e s and magnetostatic
fields  in the same way a weak two dimensioal irregularity which
is parallel to the direction of the magneto static field travels
with a constant velocity and preserves its shape more complicated
irregularities do not preserve their shape
   /
228
a discussion of the motion in nitrogen of free electrons with small
energies with reference to the ionosphere  it is found that the collision
cross section of electrons is proportional to their velocity
from this result an accurate expression is derived for the velocity
of electron drift in terms of the mean energy of the electrons  the
energy losses are found to be mainly due to excitation of the rotational
states of the nitrogen molecules
   /
229
a theory of electrostatic fields in t horizontally stratified ionosphere
subject lo a vertical magnetic field  a discussion of a possible
explanation of spread f and radio star scintillation
   /
230
new methods and some results concerning true ionospheric height calculations
   /
231
transient fine structure of the e layer  a note on the fine structure
of the e layer and its variability as observed using an ionosonde
with high power and slow frequency variation
   /
232
the ionospheric e layer at cape hallett  ionograms were examined
and the e layer critical frequencies of those unaffected by ionization
movements were compared with those expected on a simple chapman model
agreement was good when an electron recombination process was considered
for the model
   /
233
the gyro frequency in the e layer above slough england
   /
234
the early morning e layer and some evidence of pre sunrise f layer
splitting  observations at haringhata india show that cusps and ridges
are regular sunrise phenomena at that location with marked seasonal
variations in character and frequency of occurrence  a splitting
of the f layer during early morning in winter is also observed and
the possible bearing of this on the e layer phenomena observed is
discussed
   /
235
annual distribution of sporadic e
   /
236
sporadic e ionization over lindau harz during last year
   /
237
annual wave in the world wide f region ionization
   /
238
note on the cause of ionization in the f region
   /
239
a new theoretical model of the composite f layer  it is suggested
that bifurcation of the f layer is caused by a fairly rapid variation
in temperature gradient and that tidal variations have only secondary
effects
   /
240
single and double inflexions on the f arace  an attempt is made to
explain the bifurcation of the daytime f layer in terms of the appleton
lyon theory of the height lag  f layer models are considered and
since the height lag decreases through the day bifurcation lakes
place
   /
241
anomalous ionospheric reflection during solar eclipses  analysis
of electron densities during an eclipse shows that while the slope
and curvature of layer strata are mostly very small effective discontinuities
can occur which would produce complexities in ionograms  these
complexities are due to rays reflected along paths inclined to the
vertical
   /
242
on artificial geomagnetic and ionospheric storms associated with
high altitude explosions  the electron density in the outer ionosphere
sudden changes in the virtual height of radio waves reflected from
the e region of the ionosphere  it is shown that the lower level
reflections are from thin layers within the normal e region  the
changes in amplitude are used to deduce the thickness of these layers
and the electronic collision frequency in the e region
   /
243
the interpretation of sudden field anomalies in the long wave range
during solar flare effects
   /
244
the height of f layer irregularities in the arctic ionosphere
   /
245
observations of the ionosphere over the south geographic pole
   /
246
motions in the magnetosphere of the earth  the magnetosphere is defined
as the region above the ionosphere in which the earths magnetic field
has dominant control over the motions of gas and fast charged particles
conditions in the magnetosphere and the mymamical behaviour of its
constituents are discussed
   /
247
horizontal movements of visual auroral features
   /
248
existence of an inner auroral zone  study of a population of aurora
which seems to form an inner auroral zone
   /
249
type b aurora in the antarctic  the results of auroral observations
are discussed and an excitation mechanism is suggested to explain
the type b spectrum
   /
250
v h f and u h f radar observations of the aurora at college alaska
   /
251
directional observations of radio noise from the outer atmosphere
   /
252
spaced observations of radio noise from the outer atmosphere
   /
253
location of initial sferics of long whistlers  sources of atmospherics
were located by a u s s r research vessel in the vicinity of ireland
in december and coincidences with long whistlers were observed  one
of the records is analysed
   /
254
synthesis of the waveforms of atmospherics and effective parameters
of the lower ionosphere at low frequencies
   /
255
using digital techniques in time encoders  a decimal indication of
the elapsed time is given every twenty seconds  the output is suitable
for either magnetic tape or paper chart recorders
   /
256
the design of transistor push pull d c converters  the circuit least
affected by external influences is a square wave oscillator controlled
by a saturating transformer  design formulae are given
   /
257
equations for designing transistor power supplies  basic design equations
and graphs for transistor d c d c converters are given
   /
258
operational and storage life of silicon rectifiers  results are given
of life test measurements of forward voltage drop and reverse current
   /
259
controlled rectifiers drive a c and d c motors  by using saturable
magnetic core firing circuits the size and weight of switching devices
are reduced  half wave and full wave push pull circuits are described
   /
260
contribution to the problem of limiting values for semiconductor
circuit elements  the danger of exceeding the permissible voltage
limits in series connected power rectifier elements is discussed
this difficulty can be overcome by the use of parallel resistors
or capacitors as shown in the reverse voltage time curves given
   /
261
voltage and current stabilization with power transistors  basic circuits
and design data and details of two power units are given
   /
262
new digital computer techniques  a report of specialist discussion
meetings of the measurement and control section of the i  e  e  dealing
with character recognition peripheral equipment low temperature storage
and switching devices and special aspects of logical design
   /
263
study of certain errors in analogue computers  linear and nonlinear
imperfections in adding and integrating circuits are related to errors
in the solution of differential equations  analogue computers using
only a  c  amplifiers are shown to be a practical proposition
   /
264
electronic rotor  a method is described for introducing the concepts
of bearing and angle into fast cartesian analogue computations without
the use of mechanical shafts and servomechanisms
   /
265
microwave computer circuits  examples of the use of microwave components
and techniques in the construction of simple high speed computing
elements are given  main problems are the cost and complexity of
the waveguide systems required
   /
266
use of a diode ring as a four quadrant multiplier  the operation
of a diode ring as a passive analogue multiplier is analysed
   /
267
electronic digital computers
   /
268
noise of resistors and resistor combinations without and with load
noise due to current flow in carbon film type resistors is particularly
considered  the increase over thermal noise is controlled by a factor
which depends on loading film dimensions and the construction of
the resistor from this a formula is derived which contains a constant
dependent on film material
   /
269
the impedance of non quasi stationary annular plate capacitors  the
maximum permissible dimensions for the avoidance of self resonance
are calculated for high frequency grid stopper and lead through capacitors
   /
270
the reliability and life of impregnated paper capacitors  the construction
of paper capacitors and the problems associated with failure
in them are reviewed  possible methods of prolonging life and reducing
failures are discussed
   /
271
coaxial resonators with helical inner conductor  resonators of small
size can be designed for the v  h  f  and h  f  ranges  design formulae
are simple and have been confirmed by experiment
   /
272
general energy relations in nonlinear reactances  an alternative
derivation to that used earlier is based on conservation of energy
and the properties of the device
   /
273
a simplified derivation of the manley and rowe power relationships
   /
274
the determination of canonical reactance quadripoles with prescri
ed iterative matrix  the iterative matrix of any reactance quadripole
is realized by means of canonical circuits  the method consists in
developing a two pole function into a continued fraction  this function
represents the impedance of the two pole network which results from
terminating by unity resistance the output of a quadripole realizing
the given matrix
   /
275
applications of wave matrices for calculations over terminal networks
with transverse symmetry  an extension of the method used in the
classical theory of linear networks and based on bisecting the four
terminal network
   /
276
modern network theory in electrical engineering  report of a conference
held by the department of electrical engineering of the university
of birmingham
   /
277
some considerations on the stability of electrical circuits  a definition
of stability based on an integral equation is proposed  it is
considered to be more general in applicability than the definitions
of bode and james and weiss
   /
278
multistage amplifier stability design criteria  the stability of
a cascade amplifier is considered for the two cases where the stability
factors of all the stages are equal a  before cascading and b  after
cascading  a short discussion of the results is given
   /
279
push pull amplifier balance  negative voltage feed back may be applied
independently to the two sides of a push pull amplifier circuit by
the insertion of an inductance and shunt resistance network in the
lead to the primary centre tap of the output transformer
   /
280
reducing amplifier distortion  a method is described for correcting
the nonlinear distortion in valve amplifiers using metallic rectifiers
as nonlinear resistances  examples of corrected single ended and
push pull amplifiers are given
   /
281
some design considerations for high frequency transistor amplifiers
the interaction between output and input due to internal feedback
in the transistor is illustrated and design data are developed for
networks used to overcome this  many practical amplifiers are simple
and require a minimum of design effort
   /
282
spin spin energy transfer and the operation of three level masers
   /
283
construction of a strong field maser type self oscillator  proton
spin resonance in a current of magnetically polarized water is applied
in the design of a maser which operates in stable conditions without
parasitic modulation
   /
284
operation of a zero field x band maser
   /
285
operating characteristics of an ammonia beam maser  the simple theory
is expanded to predict the angular distribution of the molecules
leaving the collimator and the effect of the focuser on the velocity
distribution  comparison with experimental data shows the importance
of collisions and beam divergence
   /
286
parametric amplification and conversion in propagating circuits using
nonlinear reactances  the case of a time varying reactance coupling
three propagating circuits is analysed
   /
287
noise figure for a travelling wave parametric amplifier of the coupled
mode type
   /
288
an extremely low noise six kmc s parametric amplifier using gallium
arsenide point contact diodes  variation of excess noise temperature
with diode temperature has been measured a range of values comparable
to that for a maser has been obtained
   /
289
x band parametric amplifier noise figures  two types of gaas point
contact diode with improved gain bandwidth properties have been examined
   /
290
low noise parametric amplifier using germanium p n junction diode
at six kmc s  experimental arrangements and results are given for
noise figure measurements at various bias voltages and temperatures
   /
291
subjective colour tests  land colour is found to depend on subjective
effects and picture composition to convey the colour information
to the mind of the observer  it does not therefore offer a practical
system for colour television
   /
292
crystal stability and the theory of ferroelectricity
   /
293
influence of an electric field on an optical absorption edge  the
absorption edge displacement in a crystal with external field strength
of the order is interpreted
   /
294
deviation from matthiessens rule and lattice thermal conductivity
of alloys  the difference in the ideal electronic thermal conductivity
between an alloy and a pure metal can be estimated from the corresponding
difference in the ideal electrical resistivity using the wiedemann
franz law
   /
295
the inverse skin effect  the axial current density in an infinite
cylindrical conductor is calculated as a function of radius and time
rigid and radially expanding conductors are treated current density
distributions are obtained which sometimes have no resemblance to
the normal skin effect
   /
296
irreversible thermodynamics and kinetic theory in the derivation
of thermoelectric relations  considerations of irreversible thermodynamics
simplify the determination of thermoelectric coefficients using
kinetic theory arguments based on boltzmanns equation  a new expression
for thomsons coefficient has been derived  only simple models lave
been used but the theory is capable of extension to more complex
ones
   /
297
the structure of a stream of electrons and ions drifting and diffusing
in a gas when ionization by collision and molecular attachment are
present
   /
298
calculation of the thermal conductivity of an ionic current  a th
rmal conductivity tensor for the ionic part of a plasma is derived
from kinetic theory
   /
299
electric field distributions in an ionized gas  a method for improving
systematically the holtsmark distribution is described  it is then
applied to the calculation of the distribution of the high frequency
component of the electric field in an ionized gas in thermal equilibrium
   /
300
space charge waves in cylindrical plasma columns  the existence of
space charge waves in stationary plasmas of finite cross section
has been demonstrated theoretically and experimentally  in addition
to forward waves a plasma can support backward waves when there is
a finite axial magnetic field  this makes possible the design of
a back ward wave oscillator in which the plasma is the slow wave
circuit  other possible applications are noted
   /
301
electromotive force in a highly ionized plasma moving across a magnetic
field  the e  m  f  is proportional to the flow speed  oscillographic
probe measurements of flow velocity and plasma resistance are described
   /
302
statistical mechanical theory of a random ferromagnetic system  study
of the behaviour of solid solutions of paramagnetic impurities which
are exchange coupled in a nonmagnetic substrate yields a considerable
amount of information about the nature of the exchange coupling and
the temperature dependence of the spin system
   /
303
study of the paramagnetic faraday effect  from a study of propagation
in a gyromagnetic medium the magnitude of the faraday effect is determined
as a function of the constant of the medium  the theory is applied
to rotation in paramagnetic salts and curves are derived for the
rotation angle as a function of the applied field  a description
is given of experimental apparatus and results of measurements on
mn and fe salts at wave lengths of one and ten cm are compared with
theoretical calculations
   /
304
structure of the electromagnetic field  a mathematical study of the
structure of a curved space time in which a source free e  m  field
is present
   /
305
helical fields  simple analytic helically invariant solutions of
the laplace equation are given and combined to describe the e  s
field of a charged helix and the magnetic field of a helical electric
current  certain graphical flux plotting methods are out lined and
illustrated and network analogies are suggested for solving these
fields
   /
306
significance of electromagnetic potentials in the quantum theory
contrary to the conclusions of classical mechanics there exist effects
of potentials on charged particles even in the region where all the
fields vanish  the significance of this is discussed
   /
307
microwave magnetic field near a conducting perturbation  experiments
are described to show that locally intense microwave magnetic field
strengths can be obtained with low power levels by using a conductor
to perturb the microwave electric field of a resonant cavity
   /
308
radiation produced by the transit of charged particles near ideally
conducting bodies  expressions are obtained for the energy and radiation
spectrum  the excitation of oscillations by electrons entering a
circular waveguide from an open half space is discussed
   /
309
radiation from particles exceeding the velocity of light and several
applications of it in experimental physics  the history of the discovery
and interpretation of cerenkov radiation is outlined  the application
of radiation measurements in the investigation of cosmic ray showers
is discussed
   /
310
vertex excited surface waves on both faces of a right angled wedge
   /
311
diffraction by an infinite slit  a rigorous analysis of the problem
for plane waves with special emphasis on short wavelengths and grazing
incidence
   /
312
construction of a strong field maser type self oscillator
   /
313
on the asymptotic series expansion of the motion of a charged particle
in slowly varying fields
   /
314
self consistent field approach to the many electron problem  the
self consistent field method in which a many electron system is described
by a time dependent interaction of a single electron with a self
consistent e  m  field is shown for many problems to be equivalent
to the many body treatment
   /
315
electrodynamics of charge carriers of negative effective mass in
crystals  the transport properties of negative effective mass carriers
in crystals are studied  the electrical conductivity of a sample
in which the electron distribution function is weakly perturbed from
its thermal equilibrium value is always positive even in the presence
of a magnetic field  cyclotron resonance experiments in equilibrium
should therefore display energy absorption
   /
316
optical pumping in crystals  an estimate is made of the expected
population change in the ground state of a crystal due to optical
pumping
   /
317
the coupling of a spin system to a cavity mode  a wave mechanics
treatment is given in which the expectation value of the component
of total spin angular momentum is determined  this problem has become
important with recent developments in maser technology
   /
318
the determination of the electron density in interplanetary space
the average electron density and the arc length of the ray path from
a space vehicle to the ground can be measured by transmitting a pulse
to the vehicle on one very high frequency and receiving pulses emitted
from a transponder in the vehicle on this and on a different frequency
in this way electron densities of the order of hundred electrons
cm can be estimated
   /
319
the temperature required for nuclear reactions in cosmical electrical
discharges
   /
320
technical and astronomical measurements with the bonn twenty five
m radio telescope  details are given of operational tests on the
receiving installation of the bonn university radio telescope on
the stockert  additions to the receiving equipment and the calibration
of the aerial by series of astronomical measurements and comparisons
with results from other radio telescopes are also described
   /
321
the positional accuracy of the twenty five m radio telescope of the
bonn observatory  the tracking system and its adjustment and control
are described  details are also given of the alignment of the telescope
axes and the correction of mechanical inaccuracies of the reflector
structure
   /
322
radio star scintillations and ionospheric disturbances  spread f
phenomena are not adequate to explain scintillations at fifty three
mc s at ottawa and precipitation of solar particles seems to be involved
at high latitudes
   /
323
cosmic radio noise absorption on twenty five mc s and f scatter
a close connection is suggested between the observed anomalous enhancement
of scattered v  h  f  signals and the post sunset increase in
the attenuation of cosmic noise
   /
324
observation of the central regin of the galaxy at cm with the large
radio telescope of the g  a  o
   /
325
observation of the sagittarius a radio source at high resolution
description of observations carried out in april by the pulkovo radio
telescope  graphs show the complex structure of the source
   /
326
neutral hydrogen gas in the taurus orion region observed with a
multi channel twenty one cm line receiver
   /
327
solar radio bursts and low energy cosmic rays  events following a
solar flare are elucidated from a study of the relation between continuum
radiation and the occurrence of enlanced proton flux at the earth
   /
328
on the correlation of solar noise fluctuations in harmonically related
bands  a method is proposed for the study of the solar corona a delayed
correlation between rapid fluctuations of enhanced solar radio emission
type two in harmonically related frequency bands would be observed
   /
329
occultations of the crab nebula by the solar corona in june  the
distribution of radiation on days when the angular separation is
less than ten solar radii is not consistent with a symmetrical scattering
process better agreement is obtained by postulating the existence
of scattering and regular refraction of comparable magnitude
   /
330
energy spectrum of the leavy nuclei in the cosmic radiation
   /
331
the onset times of forbush type cosmic ray intensity decreases
   /
332
a comparison of the cosmic ray intensity at high altitudes with the
nucleonic component at ground elevation  results of balloon borne
soundings with single geiger tubes are compared with those made by
a nucleonic detector on mount washington
   /
333
on the structure of extensive cosmic ray air showers the penetrating
component
   /
334
absence of craters on the far side of the moon  the reported lower
incidence of craters on the far side of the moon may be explained
by the effect of the earths gravitational field on meteoric material
in orbit about the sun
   /
335
observations related to the impact of lunik two  a table is given
of the results of a number of independent observations of the impact
of lunik two with the moon
   /
336
first results derived from the photographs of the moons far side
photographs taken by the third soviet cosmic rocket launched october
are shown  during forty min of cam  ra operation numerous photographs
were taken of the moons far side at distances from its surface
   /
337
the temporal variation of the heights of reflection points of meteor
trails  there is no significant seasonal variation in either the
mean height or the width of the height distribution  the mean height
alone shows a diurnal variation with maximum height near midnight
both height parameters depend on the zenith angle of the apex of
the earths way
   /
338
air motions and the the mading diversity and aspect sensitivity of
meteoric echoes  a theory is given of meteoric reflection from distorted
trails  experimental results confirm the predictions and facilitate
a determination of the principal properties of the wind profile
   /
339
meteor radiant distributions and the radio echo rates observed by
forward scatter  the diurnal variations observed by forward scatter
over three different paths are found to be in reasonable agreement
with predictions made using a simplified model distribution based
on the radar data of hawkins
   /
340
turbulence at altitudes of km and its effects on long duration meteor
echoes  the characteristics of the echoes can be readily explained
in terms of multiple reflections from overdense columns of ionization
and are not consistent with the theory of incoherent scattering from
under dense columns
   /
341
prediction of sunspot numbers for cycle twenty
   /
342
note on conjugate points of geomagnetic field lines for some selected
auroral and whistler stations of the i  g  y  a method of deriving
conjugate points of some auroral and magnetic stations of the i
g  y
   /
343
geomagnetic oscillations at middle latitudes parts one and two  observations
of geomagnetic fluctuations in the frequency range cs are discussed
based on measurements at tucson arizona  the results favour the
hypothesis of intralayer hydromagnetic resonance in the ionosphere
as the source mechanism
   /
344
geomagnetic activity at halley bay on disturbed days  diurnal variations
of geomagnetic activity on disturbed days are related to auroral
and ionospheric effects  an analysis of five world wide sudden storm
commencements ssc shows positive departures of the horizontal field
before midnight and negative departures after midnight
   /
345
the relation between h and z variations near the equatorial electrojet
small fluctuations in h and z are strongly correlated particularly
during daylight hours  the ratio of the amplitudes of the components
during these fluctuations shows a marked diurnal variation but is
almost constant during the day
   /
346
note on the tidal theory of the sq magnetic field  the solar quiet
day magnetic field has a diurnal component which is roughly a thousand
times greater than expected on tidal theory  possible explanations
are given
   /
347
hydromagnetic propagation of sudden commencements of magnetic storms
a brief analysis of hydromagnetic propagation whih gives an expression
for the transit time of waves travelling in the earths equatorial
plane
   /
348
the international geophysical year  research carried out during the
i  g  y  in different branches of geophysics is reviewed  attention
is drawn to new concepts already established and to those probably
true
   /
349
space probes and satellites  a summary of the main details of all
satellite and space vehicle launchings up to april
   /
350
temperature stabilization of highly reflecting spherical satellites
   /
351
a correction necessary for the application of the doppler effect
to the measurements of distances to satellites  the use of spherical
earth geometry gives a value for minimum passing range considerably
lower than that obtained from plane earth geometry
   /
352
the fluctuations of the acceleration of satellites  the fluctuations
are associated with changes in air density at perigee height  these
density variations may be associated with changes in sunspot activity
they are in any case certainly due to variable heating at the perigee
height
   /
353
a method for measuring local electron density from an artificial
satellite  a proposal for a satellite equipped to measure the electric
and magnetic fields in the radio wave set up in the neighbourhood
of the satellite by whistler mode transmission from a grou d based
v  l  f  transmitter  from the wave impedance given by the ratio
of the fields the local electron density could be deduced
   /
354
applications of the molecular refractivity in radio meteorology
a discussion of the advantages of molecular refractivity as a significant
parameter in studies of climatic differences and air mass characteristics
   /
355
radio refractive index climate near the ground  world wide m  ps
of refractive index contours are given  the index varies systematically
with climate and is most accurately deduced from charts of the reduced
to sea level index
   /
356
central radio propagation laboratory exponential reference atmosphere
a model for the variation of atmospheric refractive index with height
is proposed which gives more accurate radio ray profiles than the
earth radius treatment  a sample table of ray profiles is given
   /
357
analytic and experimental electrical conductivity between the stratosphere
and the ionosphere  results for the height ran  e km obtained
from rocket soundings are compared with predicted values based on
ion equilibrium and ionization by cosmic rays only
   /
358
detection of an electrical current in the ionosphere above greenla
d  a description of measurements made on august using a rocket borne
magnetometer  the average current density of the layer detected was
about eleven a km
   /
359
langmuir probe measurements in the ionosphere  measurements are described
of electron temperature and positive ion number density of the
e layer above fort churchill manitoba on november
   /
360
note on quiet day vertical cross sections of the ionosphere along
geographic meridian  a discussion of results now being obtained from
stations on the meridian
   /
361
gyro frequency in the ionospheric regions  experimental results show
that the magnetic fields calculated from gyro frequencies in the
e f and f regions are higher than expected  the e region gyro frequency
las a marked semidiurnal variation with a minimum at midday
   /
362
an investigation of the ionospheric d region  a model of the lower
ionosphere is obtained from the observation of weak echoes from the
d region and the measurement of ionospheric wave interaction
   /
363
some measurements of collision frequency in the e region of the ionosphere
measurements are made by observing how the deviative absorption
of a radio echo varies with changes in its group path as a critical
frequency is approached collision frequency at a fixed height seems
to increase with solar activity
   /
364
e region winds  the suggestion that heating of the e region by the
sun is responsible for e region winds is supported by some experimental
results
   /
365
a relation between giant travelling disturbances and sporadic e ionization
ionosonde records for the july show a relation between e anomalies
and travelling disturbances  sequential e and f cusp type anomalies
are also discussed in relation to these disturbances
   /
366
two anomalies in the behaviour of the f layer of the ionosphere
report of a study of electron density data at a number of widely
distributed observatories during equinox in a year of high sunspot
activity  results show that the geomagnetic anomaly described by
appleton extends much farther from the magnetic equator as lower
heights are investigated  a diurnal asymmetry also exists with forenoon
electron densities greater than corresponding afternoon ones
   /
367
some remarks on motion of ionospheric irregularity  the relative
motion between irregularities in electron density and their surroundings
is discussed  two treatments of the problem are considered the surrounding
ionization being assumed to be a  a hydromagnetic fluid and b
a fully ionized gas
   /
368
the motion of irregularities in the ionosphere  the mean velocity
of irregularities in electron density is determined using simple
turbulence theory  the irregularities move with the same velocity
as the winds in the e region but there is a marked difference from
wind velocity in the f region
   /
369
world wide measurements of horizontal ionospheric drifts  a critical
survey is made of radio techniques for measuring horizontal drifts
a comparison is then made of results obtained during the i  g  y
using the closely spaced receiver method which discloses seasonal
and latitudinal differences in the diurnal variation of drifts  tentative
explanations of these results are given
   /
370
ionospheric drifts at xamagawa in japan  drift speeds diurnal variations
of the drift vector and the relation between speed and geomagnetic
activity are discussed using results obtained during about one year
from august
   /
371
ionized irregularities and wing motion in the ionosphere  the motion
of irregularities in electron density are studied on the basis of
a three dimensional model  electrodynamic effects are slight in the
e region under magnetically quiet conditions but are appreciable
in the f region and even in the e region for disturbed conditions
at high latitudes  a general discussion on the stability and lifetime
of regions of irregular electron density is given
   /
372
horizontal winds and ionization drifts in the ionosphere  from a
study of geomagnetic observations during the international polar
year it is concluded that ionization drifts in the f region are due
to an applied electric field and not to air movement while in the
e region the ionization drift is almost the same as the air movement
   /
373
horizontal drifts in the e region at waltair  results of an analysis
of data obtained over a two year period  a twenty four hourly east
west component predominates
   /
374
study of winds in the f region of the ionosphere during the unusual
days in the i  g  y  calendar  fading records were taken at mc s
on three spaced receivers at banaras  the experimental results are
described and the fading records discussed with reference to the
random and steady movement of irregularities
   /
375
a theory for determining upper atmosphere winds from radio observations
on meteor trails
   /
376
the effects of a solar eclipse on a stratified ionosphere  the form
of the isoelectronic surfaces in a three layer ionosphere during
an eclipse have been calculated  tilts in these surfaces may lead
to difficulties in the interpretation of ionograms
   /
377
the behaviour of the ionosphere over cape town and johannesburg during
the annular solar eclipse of december  it was not possible to explain
the ionospheric changes at cape town johannesburg and grahamstown
in terms of a single solar brightness model  oblique reflections
may have affected the ionograms
   /
378
the frequency dependence of ionospheric absorption  the total absorption
was formerly expressed as a function of nondeviative d layer plus
deviative e layer absorption  the expression has been modified to
include the effect of a thin e layer experimental data are discussed
in the light of the new theory
   /
379
the absorption of short radio waves in the d e and f regions of the
ionosphere  values of noon absorption at slough have been analysed
the electron collision frequencies for the e and f regions have been
calculated and the variations of d region absorption with sunspot
number examined  the significance of the results is discussed
   /
380
the use of full wave solutions in the interpretation of ionospheric
absorption measurements  a full wave correction is given which can
be made to the usual appleton hartree absorption calculation  examples
show that for a frequency of two mc s this correction cannot be neglected
   /
381
measurements of ionospheric electron content by the lunar radio technique
measurements of the faraday rotation of lunar radio echoes are
used to determine the time variation in the total ionospheric electron
content  absolute values of electron content are derived from data
on the electron content below the f peak computed from vertical incidence
experiments
   /
382
excitation mechanisms of the oxygen emission in the upper atmosphere
photochemical reactions affected by mass motions and direct excitation
due to mass motions are examined
   /
383
auroral and night glow observations at as norway  more precise wavelength
measurements are given for bands of the meinel oh system in the night glow
   /
384
photometric observations of subvisual red auroral arcs at middle
latitudes  the arcs have been observed on the night following a bright
visual aurora at a time whe the magnetic disturbance index had fallen
to five or less
   /
385
the southern auroral zone in geomagnetic longitude sector  visual
auroral observations at antarctic bases are tabulated to show the
variation of the frequency of aurora occurrences with geomagnetic
latitude
   /
386
antarctic auroral observations ellsworth station  a summary of auroral
observations made during the antarctic winter  evidence is obtained
of a spiralling zone of maximum auroral activity
   /
387
spectroscopic observations of the great aurora of february  spectrograms
show an enhancement of vibrational excitation which can be attributed
to a charge exchange process in a strong proton shower  these spectrograms
also show a large number of atomic lines seldom seen
   /
388
a monochromatic low latitude aurora  a particular monochromatic auroral
arc which occurred over colorado is described  it seems to have been
a continuation of a similar one observed in france
   /
389
telluric origin of the whistler medium  arguments are presented to
show that the medium cannot be of solar or interplanetary origin
and a mechanism is suggested for a telluric origin
   /
390
effect of latitude on the diurnal maximum of dawn chorus  observations
of the local time of diurnal maximum have been made at sixteen stations
analysis based on an eccentric dipole field is useful when considering
dawn chorus theories
   /
391
cosmic electrodynamics  this book bearing a similar title to that
by alfven indicates the progress and consolidation achieved in the
field during the intervening decade
   /
392
electronic line storage device for the compression of the frequency
band of periodically recurring signals particularly of radar displays
the operation of a c  r  tube line storage system is discussed  equipment
is described for measuring the integrating characteristics of
such storage devices
   /
393
a small high voltage regulated power supply with variable output
the design of a regulating circuit operating in the range is described
which uses a beam tetrode as a series regulator and two double triodes
in the feedback circuit
   /
394
a transistorized l  t  regulator
   /
395
computers and computer equipment design  a group of nine papers on
practical aspects of digital computer design and recently developed
techniques
   /
396
electronic computers and the electronic computer study centre at
pisa  outline of the program and future development of the centre
with details of available equipment
   /
397
solid state digital code to cede converter  gray code can be changed
to normal binary code by means of the converter described  the basic
building block is a circuit comprising a magnetic core a junction
transistor and a delay network  thyratrons are used for the readout
display
   /
398
a high speed ferrite storage system  a read write cycle time can
be achieved in the small store described
   /
399
the magnetic drum store of the mercury computer  explanatory circuit
diagrams mechanical drawings and performance data of the type drum
are given
   /
400
approximation errors in diode function generators  errors resulting
from fitting a piecewise linear function to a smooth curve are discussed
in relation to analogue computor applications  a simple integral
based on best fis criteria will give the relation between number
of segments and error and also the breakpoints between segments
numerical results are given for typical functions
   /
401
theoretical study and method of operation of a logarithmic integrator
description of a computer circuit based on a diode pump action
   /
402
the construction of a digital computing system from a basic transistor
circuit  the computer uses identical basic circuits to convert decimal
numbers to and from the binary scale  diagrams of the basic circuit
and the system are given  printed circuits are used
   /
403
light pen links computer to operator  using a photodiode to read dots
produced on a  r tube enables an operator to control an associated
computer  by pointing the light pen at certain dots information can
be written into the computer
   /
404
computers aid propagation studies
   /
405
automatic character recognition  limitations and future developments
of existing machines are discussed  further analysis of the semantic
features of character patterns and of their recongnition timits leads
to a semantic pattern definition which is sufficiently general to
permit recognition of nearly illegible characters
   /
406
how analogue networks solve air conditioning problems  the thermal
properties of a unit area of the structural elements are represented
by an equivalent electrical circuit  a complelt block diagram shows
how these are used to simulate the thermal behaviour of a room and
its air conditioning system  some detailed circuitry is given
   /
407
three approaches to microminiaturizatio  construction methods for
extremely small electronic circuits are detailed
   /
408
british appreaches to microminiaturizatio
   /
409
the properties of ferrite u cores for horizontal deflection vut put
transformers  the results of measurements made with a special core
are given and discussed
   /
410
steering circuits control reversible counters  a four stage bistable
multivibrator system is used to provide decade counting  complementary
outputs from each stage dre switched to succeeding stages to give
either addition or subtraction
   /
411
approximate calculation of bistable switching circuits using junction
transistors  case of switching circuits with common emitter resistance
application of the method described earlier for the case of double
bias operation january
   /
412
dielectric devices  report of a conference held in the electrical
engineering department of the university of birmingham
   /
413
on stochastic linear systems  systems governed by nth order linear
differential equations having random coefficients are studied and
the methods developed are applied to a r l c circuit having random
capacitance variations
   /
414
design of open ended microwave resonant cavities  two types of cavity
for refractive index measurements are described one rectangular in
cross section the other cylindrical  the cavities are termin ted
in short sections partitioned so that each sub division is a waveguide
operating below the cut off frequency of the cavity
   /
415
plastic microwave cavities for epr  an x band plastic cavity for
studies of relaxation in electron par magnetic resonance is described
   /
416
generalization to nonlinear net works of a theorem due to heaviside
a theorem enunciated by heaviside and proved by lorentz for linear
electromagnetic systems subjected to a suddenly impressed constant
electric force is extended to electrical net works comprising nonlinear
reactances and linear resistance
   /
417
classes of four pole networks having nonlinear transfer characteristics
but linear iterative impedances  a graphical representation is introduced
which simplifies the analysis of networks containing nonlinear elements
the properties of dual nonlinear resistances in which the relation
for one resistance is the same as the relation for the other are
considered such duals if realizable would permit the design of nonlinear
four poles having linear iterative impedances which could be cascaded
   /
418
theory of noisy two pors networks  the geometric analytic theory
presented is based on the isometric sphere metred and on a three
dimensional conformal transformation
   /
419
impedance transformations through lossless two ports represented
by fractional linear transformations of the unit circle  the automorphism
of a unit circle corresponding to an impedance transformation
is characterized by three parameters and can be represented by three
successive elementary transformations  this leads to a simple graphical
method using caoter or smith charts for the determination of the
transformed impedance and for the treatment of cascades of lossless
two ports
   /
420
constant resistance all pass networks with maximally flat time delay
practical design tables are given and their use is illustrated by
examples
   /
421
the loss attenuation in the pass band of wave filters with differing
coil factors  the loss contributions of the individual coils are
summed using weighting functions  application of the method to a
crystal filter half section is explained
   /
422
an analysis of a type of comb filter  a theoretical analysis and
discussion of practical devices for use in radar as moving target
indicators and signal integrators
   /
423
calculation of the static characteristic of a nonlinear multipole
without inertia when the dynamic characteristic is known
   /
424
high frequency transistor filter synthesis  two canonical ladder
structures of hybrid two and hybred t type are considered  the intrinsic
feedback factor is ignored  examples of cascaded structures are given
   /
425
the effect of cathode impedance on the frequency stability of linear
oscillators  long term frequency instability due to the growth of
an interface layer between oxide coating and cathode may be reduced
by suitably adjusting the ratio of anode to grid voltages
   /
426
voltage sensitivity of local oscillators  the dependence of the oscillation
frequency of valve oscillators on certain operating conditions
is discussed and defined mathematically in terms of independent variables
   /
427
how to generate accurate sawtooth and pulse waves  two circuits giving
stable sawtooth and rectangular pulse outputs are described in which
a high speed switching transistor is controlled by a zener diode
pulse width and amplitude and waveform timing are independent of
active elements in the circuit
   /
428
a method of combining two frequencies  a new method of frequency
synthesis is described in which two equal amplitude tones are combined
by limiting phase inverting and selecting the correct polarity at
a control gate
   /
429
the definition of noise factor when applied to systems containing
negative resistance elements  the concept of available power and
the definition of noise factor are extended to include negative resistance
by using the idea of exchangeable power
   /
430
wide band analysis of valve phase splitting circuits  accurate and
approximate design data are developed and compared with results of
measurements  near ideal operating conditions can be obtained up
to a fow megacycles with suitable load impedances
   /
431
analysis of the transistor cascade configuration  neutralization
is not necessary more gain per unit volume and weight is achieved
than in other transistor configurations while cost per unit gain
is about equal to that of more conventional circuits
   /
432
transistor constant volume amplifier  design and circuit details
of a microphone amplifier providing substantially similar output
signal levels for various speech input levels
   /
433
transistors in video equipment  the importance of the product current
gain bandwidth is discussed  a new design method is described which
gives greater gain bandwidth factors  the conditions for maximum
signal noise ratio are determined and confirmed experimentally  signal
noise ratios aad gain bandwidth factors are comparable to those of
valves
   /
434
transistorized distributed amplifier  the characteristic impedance
of both the base and collector transmission lines
   /
435
solid state maser amplifier  the principles of maser operation are
introduced and the essential details of a practical cavity maser
system are described
   /
436
maser operation with signal frequency higher than pump frequency
an x band solid state maser is described using the four zeeman levels
in ruby
   /
437
investigation of the oscillation voltage of a strong field maser
type self oscillator  investigation of a maser of the type described
earlier of march in which tie macroscopic polarization of the protons
is made antiparallel to the directive field  experimental and theoretical
curves are thown for different rates of flow
   /
438
experimental verification of parametric amplifier excess noise using
transformer coupling  a method is described for measuring noise temperature
at frequencies where circulators aoe not available
   /
439
an analysis of parametric amplification in periodically loaded transmission
lines  the propagating structure is considered as a lossless
transmission line periodically loaded with nonlinear capacitance
in the form of back biased semiconductor diodes  information is given
about the relation of diode parameters spacing and circuit parameters
to the gain and bandwidth of the structure
   /
440
fast wave couplers for longitudinal beam parametric amplifiers
   /
441
three level maser detector for ultra microwaves  note on the principles
of a device similar to the spectrometer described earlier  the absorption
at ultra microwave frequencies changes the population of levels
and results in an increase or decrease of absorption at a lower microwave
frequency
   /
442
mode theory of lossless periodically distributed parametric amplifiers
   /
443
reactance transistor  frequency deviation curves calculated from
the theoretical output admittance are compared with measurements
for oscillator circuit
   /
444
on explanations of electric and magnetic constants and units  using
dimensional methods the relation of freespace dielectric constant
and magnetic permeability constant to four fun  amental quantities
is considered  other constants are also analysed to obtain methods
of understanding the submicroscopic nature of electric and magnetic
phenomena
   /
445
variational approach to deviations from ohms law  kohlers variational
method has been used to obtain deviations from ohms law for a nondegenerate
electron gas  two important applications of the method are discussed
   /
446
many particle approach to the one electron problem of insulators
and semiconductors  motion of an electron near the bottom of the
conduction band in the presence of external electric and magnetic
fields whose variation over one lattice spacing is small is governed
by a simple schrodinger equation
   /
447
energy levels of conduction electrons in a magnetic field  the energy
levels can be obtained simply if the spherical approximation is made
for the band structure  the free energy due to small departures from
this assumption may be estimated using perturbation theory  inclusion
of spin orbit coupling gives the factor as a function of position
in the band
   /
448
the current sheet in a gas discharge  deals with the trapping of
cold gas in the sheet
   /
449
studies of cold cathode discharges in magnetic fields  mass spectrometer
measu  ements were made to determine the ion energies  the mechanism
of the discharge is discussed
   /
450
theory of secondary electron emission of metals the excitation process
   /
451
theory of secondary electron emission metals the transport process
   /
452
conductivity of a warm plasma  a theory for obtaining the conductivity
of a uniform plasma as a function of frequency and temperature is
presented and compared with a number of recent treatments
   /
453
experiments with plasma rings  a brief description is given of a
plasma gun discharging into a glass drift tube  measurements have
been made of the circuit current and the magnetic flux carried by
the plasma
   /
454
oscillations in plasma part two  discrete oscillations reported are
studied in detail  oscillations at the higher frequency are generated
by the convergent beam in the central part of the tube while those
at the lower frequency seem to be generated near the wall of the
tube by the divergent beam  another oscillation having an intermediate
frequency is often observed
   /
455
occurrence of vavilov cerenkov radiation in a high temperature plasma
analytical results indicate that radiation is not emitted by a particle
moving through a high temperature plasma at a velocity lower than
the mean thermal velocity of plasma electrons
   /
456
longitudinal and transverse waves in a lorentz plasma  the triple
refraction in inhomogeneous plasma is dis  ussed
   /
457
radial hydromagnetic oscillations  the equation of motion of radial
hydromagnetic oscillations of a plasma confined by an axial magnetic
field is integrated and shown to give good agreement with experiment
   /
458
discharge phenomena in lorentz type plasmas investigation of electron
distribution in the presence of a magnetic field  a partial differential
equation derived by kahan and jancel is integrated for the case where
the collision frequency is constant
   /
459
the half plane diffraction problem for harmonic time dependence
greens functions are obtained for the boundary value problems of
mixed type describing the general two dimensional diffraction problems
at a screen in the form of a half plane sommerfelds problem applicable
to acoustically rigid or soft screens and to the full electromagnetic
field at a perfectly conducting screen
   /
460
the diffraction of scalar waves on paraboloids of revolution
   /
461
diffraction by an imperfectly conducting right angled wedge  an exact
solution is given for the diffraction of the fie d of an electric
line current by an imperfectly conducting wedge of exterior angle
   /
462
diffraction of an e polarized plane wave by an imperfectly conducting
wedge  a new and exact solution is obtained for arbitrary wedge angle
   /
463
propagation of electromagnetic waves in a multistream medium at gyromagnetic
resonance  formulae are derived for the dispersion and the
gyromagnetic resonance effects
   /
464
measurement broadening in magnetic resonance  phase detection techniques
cause broadening a method for correcting observed widths is described
   /
465
form effect in magnetostriction
   /
466
a simplified theory of two carrier space charge limited current flow
in solids
   /
467
zeeman splitting of paramagnetic atoms in crystalline fields  energy
levels of paramagnetic ions in crystalline surroundings are treated
as a function of magnetic field
   /
468
theory of bloch electrons in a magnetic field the effective hamiltonian
for a no degenerate band the eigenstates of the hamiltonian of a
bloch electron in a static magnetic field can be calculated from
an equivalent hamiltonian whose properties and formulation are discussed
   /
469
symposium on the exploration of space  the text is given with subsequent
discussion of twelve papers read at a symposium in washington
   /
470
national radio astronomy observatory  the history and development
of the radio observatory at green bank west virginia are reviewed
   /
471
the mullard radio astronomy observatory  two aperture synthesis radio
telescopes installed near cambridge are described and an outline
is given of the present research program
   /
472
tie six hundred radio telescope  description of of the steerable
telescope under construction in west virginia
   /
473
observations on the solar eclipse of october  a report of measurements
made simultaneously at hamilton  at this location the sun rose partially
eclipsed nd was totally eclipsed at an elevation
   /
474
nature of corpuscular radiation of the upper atmosphere  the concentration
of particles in the solar corpuscular stream is sufficient to
renew the corpuscles of the outer radiation belt over a period of
only a few hours  an estimation is made of the energy spectrum of
protons and the velocity of generation of hard corpuscles in the
inner belt
   /
475
heavy primary cosmic rays at geomagnetic latitude  results from nine
balloon flights at heights charge spectra flux mean free paths and
angular distributions are given
   /
476
primary cosmic ray proton and alpha particle intensities and their
variation with time  results of a series of high altitude balloon
flights made primarily to investigate the short term variations of
primary protons and alpha particles
   /
477
cosmic ray measurements in the vicinity of planets and some applications
part one primary cosmic radiation  the variation of the primary cosmic
ray intensity is calculated as a function of distance from a dipole
in its equatorial plane  scientific applications indicated include
the determination of magnetic fields of the moon and planets
   /
478
low energy cosmic ray events associated with solar flares  details
are given of events during the period which have been detected by
the measurement of ionospheric absorption in arctic regions
   /
479
the apparent sidereal daily variation of cosmic ray intensity during
the recent sunspot minimum
   /
480
magnetic cut off rigidities of charged particles in the earths field
at times of magnetic storms  cut off rigidities are calculated for
charged particles at various locations and for different distances
of the storm sloud from the earth
   /
481
the transmission of geomagnetic disturbances through the atmosphere
and interplanetary space  the theory of the propagation of slowly
varying disturbances through partially ionized gas is developed and
applied to the earths atmosphere and interplanetary space  the medium
is considered as two separate co existing gasses an electron ion
plasma and neutral atoms which move to some extent independently
quantitative results are given for a model atmosphere extending to
several earth rad
   /
482
studies of magnetic field micropulsations with periods of seconds
the studies were carried out in southern california
   /
483
geomagnetic storms and ionospheric disturbances  a collection of
papers covering the morphology of geomagnetic and ionospheric storms
an application of the atmospheric dynamo theory to geomagnetic variations
uring disturbances and a study of hydromagnetic oscillations
of the ionized upper atmosphere
   /
484
the relationship between geomagnetic variations and the circulations
a statistical study for a five year period leads to the conclusion
that there is no obvious relation between the two sets of data
   /
485
radio and the i g y summaries of the data collected the analyses
used and the knowledge obtained about the ionosphere an outer space
during the i  g  y  proceedings of fourth meeting of the joint commission
on radio meteorology  the tept is given of papers presented at
the meeting held in new york
   /
486
artificial earth satellites and space travel part one  the satellite
orbits and their changes with time  a table is included giving full
details of earth satellites and moon probes successfully launched
up to september
   /
487
lunar and solar perturbations on satellite orbits  the lunar and
solar effects on perigee height for satellite orbits of large eccentricity
are investigated
   /
488
determination of the true distribution of electron density in the
ionosphere part two  the accuracy of the methods summarized in part
one  results obtained with out consideration of the geomagnetic field
are found to be completely uncertain
   /
489
on the seasonal and nonseasonal annual variations and the semiannual
variation in the noon and midnight electron densities of the layer
in middle latitudes part two  previous work is continued using two
groups of relatively high and low latitude stations  the seasonal
variation for the high latitude stations is markedly different from
that of the low latitude group while the nonseasonal variations do
not show great differences between the groups  the semi annual variations
in the two graphs are also not markedly different
   /
490
a statistical study of world whde occurrence probability of spread
f parts one and two  diurnal seasonal and latitudinal variations
in the occurrence of spread f during the i g y are analysed  marked
differences between high and low latitudes suggest an essentially
different origin for the phenomenon in the two regions  the correlation
of spread f with geomagnetic activity is discussed and abnormal occurrences
during magnetic storms are examined in detail
   /
491
proceedings of fifth meeting of the mixed commission on the ionosphere
of i c s u  the text is given of papers presented at the meeting
held in new york
   /
492
the ionospheric faraday effect and its applications  measurements
of ionospheric characteristics by means of lunar radio reflections
and satellite radio transmissions using the faraday effect are discussed
   /
493
influence of absorption on the reflection coefficient of the ionosphere
the reflection coefficient of a stratified layer is considered assuming
that electron concentration varies linearsy with height absorption
is represented by a viscous resistance proportional to the velocity
of free electrons
   /
494
pre s c polar cap ionospheric black out and typeiv solar radio outburst
short wave radio blackouts in polar cap regions are often found to
occur well before the sudden commencement magnetic storms and this
phenomenon is closely correlated with the occurrence of type iv solar
bursts  a possible explanation of these effects is given which is
consistent with other related phenomena such as cosmic ray storms
   /
495
ionosphere review  comparison of the condition of the ionosphere
with that of previous years and deduction of the probable state
   /
496
global hydromagnetic wave ducts in the exosphere  magnetic field
perturbations originating from a high altitude explosion have been
observed at a number of stations  an analysis of results indicates
that hydromagnetic waves at high altitudes travel along great circle
paths in ducts which are concentric shells about the earth  slow and
fast signals are identified respectively with transverse and longitudinal
hydromagnetic wave modes
   /
497
aurora like radar echoes observed from latitude  a note on anomalous
echoes observed regularly at a shipborne radar located in british
west indies
   /
498
correlation of audio frequency electromagnetic radiation with auroral
zone micropulsations  a spectrum analysis has been made of recordings
obtained during three one month periods near kiruna sweden  there
is excellent correlation between auroral zone micropulsations and
radiation  two distinct frequency bands have been identified
   /
499
rare hiss earth current and micropulsations on november  brief report
of hiss and micropulsations associated with a sudden commencement
at alaska
   /
500
direction findings on whistlers  the use of a crossed loop type of
direction finder and the information on whistlers to be obtained
from it are described
   /
501
the magneto ionic theory and its application to the ionosphere
   /
502
a transistor quadrature suppressor for a c servo systems  the spurious
quadrature component rn the error signal of an a c servo system is
cancelled by a self balancing circuit including thermistors
   /
503
photoece tronic chart reader of recorded ink line  design and construction
tion details are given of an equipment which samples the level of
a recorded line once every second and produces an integrated analogue
output voltage
   /
504
transistor regulated converter  regulation is controlled by a blocking
oscillator whose frequency varies as a function of the error voltage
   /
505
on the nonisothermal diffusion theory of rectifiers  a general theory
is developed from formal conduction theory the rectification equation
obtained depends upon temperature distributions in a barrier  values
of the dielectric constant of barrier determined by analysis of experimental
results using the new theory tend to approach those of the
bulk materials
   /
506
stabilization of a direct current or a magnetic field by paramagnetic
resonance  description of a system for current stabilization based
on electron resonance in a sample of paramagnetic material such as
diphenyl picryl hydrazyl
   /
507
a simple current stabilizer for electromagnets  the design of a stabilizing
circuit operating with an amplidyne generator is described
   /
508
a transistorized current stabilizer for an electromagnet
   /
509
computers head for operation  report of recent developments in phase locked
oscillators tunnel diodes and cross film cryolrons based on papers
presented at the computer conference
   /
510
low temperature storage elements  very high speeds and compactness
are features of the crowe cell in which a persistent current is set
up around an aperture in a thin superconducting film
   /
511
pulse height to digital signal converter  a transistorized analogue
digital converter provides digit binary outputs for an input at a
maximum sampling rate fo pulses
   /
512
supersonic delay line memory device for parametron signal  results
obtained with an experimental brass wire delay line are given  suitable
coupling circuits are shown
   /
513
factors influencing the applications of magnetic tape recording to
digital computers
   /
514
a magnetic disk random access memory  alphanumeric characters can
be stored with average access time
   /
515
magnetic film file for computer storage  oxide coated film store is
described in which the pickup head is not in contact with the oxide
the high quality backing medium gives complete freedom from drop outs
   /
516
high speed digital storage using cylindrical magnetic films  digital
stores consisting of closed magnetic circuits deposited on long glass
tubes are described
   /
517
a high density file drum as a computer store  a packing density has
been obtained using specially designed heads floating on an oil film
which automatically maintains a head track spacing
   /
518
analysis of quality factor of annular core inductors  a summary of
formulae used to determine factor is supplemented with a discussion
of optimum design procedures  in particular eddy currents and dielectric
losses and the effects of distributed capacitance are considered
   /
519
the ferreed a new switching device  properties of a magnetic reed
switch responsive to the resonant field of a ferrite are considered
switching times are in the microsecond range and dual wanding facilitates
coincident pulse control  the application to switching arrays is
discussed
   /
520
binocular type parametron  the method of manufacture and characteristics
of a parametron with a new type of ferrite core comprising a segmented
disk with two apertures aoe described  power consumption is about
one quarter that of the toroidal core type
   /
521
microwave switching with computer diodes  characteristics are given
of single and double throw junction diode switches  satisfactory
tests have been made on a coaxial switch
   /
522
an oscillating capacitor of high stability  the precision unit described
is designed for use with highresistance or direct voltage measuring
equipment where high stability is required  currents of were detected
with an input resistance
   /
523
certain asymptotic relations between frequency and time functions
the relations are considered with reference to networks to which
a transaent is applied and including the effect of group delay
   /
524
linear network synthesis  the rational fraction approximation is
obtained dire  tly in terms of the pole zero locations in the plane
by a process of successive approximation  the method differs from
others known successive approximation techniques in being purely
graphical apart from a final numerical relaxation process  a simple
step by step account is given of the practical procedure
   /
525
low pass filter for subaudio frequencies  details are given of a
low pass filter suitable for use in a missile borne telemetry system
the filter incorporates a transistor feedback amplifier and has a
flat response from an attenuation slope of octave
   /
526
immittance properties of nonreciprocal networks  certain known networks
are described in terms of the unitor a nonreciprocal circuit element
these include lhe batt duffin immittance synthesizing cycle impedance
inversion and conversion circuits and the symmetrical lattice network
   /
527
negative feedback in frequency changers  two different forms of negative
feedback are discussed one has only passive elements in the feedback
path and thk other has an active element with characteristics identical
to those of the forward path  their application to frequency changers
is considered with reference to gain stability
   /
528
the quality of oscillators with differently located losses  network
oscillator with parallel and series losses is investigated to determine
whether the factor can be improved by a reduction of load impedance
in conjunction with an appropriate increase in oscillator gain  the
reduction of load impedance is effected by considering the loss impedance
to be added in parallel with thk load
   /
529
a voltage tuned resistance capacitance oscillator  a circuit is given
for an oscillator whose frequency of oscillation is dependent on
an applied potential by vartue of the variable capacitance of selenium
drydisk rectifiers with reverse bias  the characteristics of suitable
rectifiers are discussed
   /
530
the generation of short high power pulses by means of spark gap switches
the characteristics of the discharge current in spark gap circuits
aoe calculated  tests were made on a triggered pulse generator caicuit
comprising two series connected spark gaps equipment used and results
obtained are described
   /
531
parametric oscillations with point contact diodes at frequencies higher
than pumping frequency  the signal and idler frequencies are symmetrically placed
with respect to a multiple of the pumping frequency  the
results are consistent with the manley rowe relations
   /
532
designing high power transistor oscillators  a step by step procedure
is ghven for the design of oscillators for operation at frequencies
   /
533
a high speed binary counter based on frequency script techniques
an extension of previous experimental investigations into bistable
oscillators fast counting circuits using eit tubes  a theoretical investigation
into the use of type eit counter tubes at pulse repetition
frequencies up together with a practical design of circuit
   /
534
efficient harmonic generation  practical harmonic generators are
reviewed briefly and the most efficient is shown to be the rectifier
amplifier type  a transistor amplifier provides best efficiency at
low powers
   /
535
a stabilized locked oscillator frequency divider the results of an
analysis of the divider are presented in a graphical form suitable
for design purposes
   /
536
negative capacitance amplifier noise  the inheret limitations of
negative capacitance feedback due to the finite time constant and
internal noise of an actual amplifier are discussed  it is shown
that the limitation caused by noise applies to any circuit that is
designed to reduce the input time constant
   /
537
ferromagnetic amplifiers  note on an absorption of microwave power
observed with a magnetized garnet sphere in a microwave field at
a frequency approximately twice that corresponding to the magnetization
   /
538
maser behaviour temperature and concentration effects  maser action
has been achieved with ruby at temperatures up to results are ghven
for operation
   /
539
a tunable x band ruby maser  performance figures and details of simplified
tuning arrangements are given
   /
540
the parametric amplifier  the mode of operation of parametric devices
is explained and generate features of semiconductor diode ferrite
and beam type amplifiers are discussed
   /
541
noise consideration of the variable capacitance parametric amplifier
a simplified theory assuming the noise source is a resistance in
series with the variable capacitance gives calculated gain and noise
figures agreeing with measured values for diodes
   /
542
some possible causes of noise in adler tubes
   /
543
wide band with capacitance diodes  two circuits are described using
voltage variable capacitors to modulate a valve oscillator
   /
544
mathematical problems of the quantum theory of particles and fields
the text is given in english of papers presented at an international
course held at varenna
   /
545
approximation formulae for the electrostatic energy of a space charge
an asymptotic approximation for the potential is derived which does
not contain terms denoting the number and magnitude of the individual
charges making up a space charge cloud
   /
546
the electromagnetic energy stored in a dispersive medium  an expression
for energy is derived by treating the dielectric as a two terminal
network having a frequency dependent admittance
   /
547
damping method in the theory of electrical conductivity  a method
as suggested for calculating the conductivity tensor similar to the
time fluctuation method used in quantum field theory
   /
548
a more precise theory of plasma recombination  recombination coefficients
are derived for two models deep traps and third and fifth group
impurity traps in ge and si
   /
549
theory of the method of thermal conductivity measurement proposed
by a  v  ioffe and a  f  ioffe
   /
550
build up of a discharge in argon  measurements of the rate of build
up at pressures and theoretical interpretation of results
   /
551
time dependent electron flow  general relations are given from which
a single vector differential equation can be deduced which determines
all possible solutions in the case of a constant uniform magnetic
field  the application of certain time variant solutions of this
equation to anomalous behaviour in various magnetron type devices
is considered
   /
552
double scattering of electrons with a dipole moment  quantum mechanical
analysis of the case where magnetic and electric fields are present
between the two targets gives the same results as are obtained by
treating the electrons as classical spinning tops with magnetic moments
and classical electric dipoles  interaction between electron beam
and magnet  the diffraction effect noted when an electron beam grazes
a sharp edge of a magnet is described and interpreted
   /
553
the time constant of secondary emission
   /
554
transport phenomena in slightly ionized gases low electric fields
calculation of transport properties in the presence of a magnetic
field  for low electric field the results can be expressed as linear
functions
   /
555
asymmetrical triple probe method for determining energy distribution
of electron in plasma  the method is an improvement on one previously
given  a much greater range of electron energies can be used in electrodeless
discharges
   /
556
action of a electric field on a plasma establishment of the equation
giving the distribution function
   /
557
excitation of oscillations in a plasma layer  application of theory
developed earlier to the excitation of standing waves in a uniform
plasma
   /
558
oscillations of a cylindrical cavity in a completely ionized plasma
investigation of the oscillations of a cylindrical cavity in a perfectly
conducting plasma with applied magnetic field  the system is shown
to be stable and under certain conditions waves cannot propagate
along the cavity
   /
559
sealed room experiments on the equilibrium of ionization in air
an attempt to determine the correct form of the equation by making
measurements of as many of the quantities appearing in the equation
as possible
   /
560
possible explanation of the coexistence of ferromagnetism and superconductivity
a discussion based on the suggestion that superconducting
regions extend only through the thicknesses of the ferromagnetic
domain walls
   /
561
electromagnetic energy momentum tensor in the presence of charged
matter
   /
562
the method of group numbers nombres combinatifs in the study of electromagnetic
fields  maxwells field equations and poyntings theorem are
given in group number form  the method is proposed for problems where
the use of complex numbers would give an ambiguous result
   /
563
radiation from a current carrying ring which moves uniformly in a
plasma located in a magnetic field  estimation of losses due to vavilov
cherenkov radiation for a current carrying ring which moves uniformly
in a plasma perpendicular to its plane and parallel to an external
magnetic field
   /
564
radiation from high speed particles
   /
565
general characteristics of vavilov cherenkov radiation  the application
of the theory of cherenkov radiation to problems of plasma physics
is considered
   /
566
the exactness of the solution of a radiation or diffraction problem
criteria of uniqueness may be applied to various problems of propagation
in media satisfying linear equations
   /
567
diffraction of a plane electromagnetic wave by a perfectly conducting
paraboloid of rotation  exact solution for arbitrary angle of incidence
and polarization  asymptotic formulae for the surface current distribution
are derived for wavelengths small compared with the focal length
of the paraboloid
   /
568
approximate calculations of the diffraction of plane electromagnetic
waves by some metallic bodies  application of the approximate method
described in part one to diffraction of a plane wave by a perfectly
conducting disk or cylinder  results are shown graphically and compared
with experimental data
   /
569
scattering by nonspherical particles  the small angle scattering
approximation of schiff is applied to several nonspherical body sharpes
effects of orientation and elongation are discussed
   /
570
signal to noise ratio in nuclear magnetic resonance  the amplifier
noise is expressed in terms of an equivalent input grid resistance
rather than in terms of a noise figure
   /
571
absorption and dispersion of microwaves in flames  the dependence
of the high frequency electric conductivity and the optical constants
of a weakly ionized gas of the microwave frequency the electron molecule
collision frequency the electron concentration and an external magnetic
field are discussed
   /
572
the influence of lattice vebrations on energy and lifetime of the
exciton  the exciton is treated as a system of two particles with
coulomb potential interaction which are coupled to the quantized
field of lattice vibrations
   /
573
new method for calculating wave functions in crystals and molecules
advantage is taken of crystal symmetry to construct wave functions
which are best described as the smooth part of symmetrized bloch
functions
   /
574
interferometer using two aerials with variable spacing at the nancay
radio astronomy station  radiation it received by two parabolic reflectors
which can be moved along a track  a signal from a common lacal
oscillator is transmitted by coaxial cables to the aerial sites multiplied
and mixed with the received signals  resulting signals are conveyed
via the same caeles to a correlator detector  results obtained with
the apparatus are shown
   /
575
resolving power of three antenna patterns derived from the same aperture
   /
576
absorption refraction and scintillation measurements with a travelling
wave tube radiometer  a report of measurements of solar radiation
at sunrise during july with a note on the equipment used  this consisted
of a dicke type radiometer a tuned receiver and a parabola aerial
on an altazimuth mount
   /
577
the correlation of bursts of solar radio emission in the centimetre
range with flares and sudden ionospheric disturbances  statistical
investigations of observations during the first six months  reveal
a close correlation between bursts in the range  it is concluded
that both the radiation and the ionizing radiation responsible are
generated by super thermal electrons
   /
578
sudden increase of cosmic ray intensity  report on simultaneous observations
in u  s  a  and new zealand which are not in accord with simple
solar impact zone theory
   /
579
primary heavy cosmic ways near the geomagnetic equator
   /
580
the sun as a source of cosmic rays of intermediate energies  cosmic
ray intensity as measured with a narrow angle telescope and thick
absorber shows a sunspot cycle variation  correlations with layer
ionization and solar flux are shown
   /
581
primary cosmic ray intensity near solar maximum  results of measurements
of proton and particle fluxes and energy spectra are given  comparison
is made with an electric field model
   /
582
cherenkov radiation in the atmosphere  a review of theoretical and
experimental work
   /
583
ambipolar diffusion of a meteor trail and its relation with height
regression lines have been derived for the relation between log and
height where the ambipolar diffusion coefficient
   /
584
a daily index of solar activity based on e layer ionization  the
electron density in a chapman layer can be related to the intensity
of the incident solar ionizing radiation  this relation has been
adopted as the basis for computing a daily index of the radiation
intensity using the critical frequency of the e layer at slvugh
precautions have been taken to minimize errors due to irregularities
in the behaviour of the layer and to the difficulty in identifying
the e layer cusp  the standard deviation of the residual errors in
the index is estimated to be twv per cent
   /
585
rapid fluctuations during magnetic disturbance  a numerically simple
ratio is defined and used to examine space relationships of rapid
geomagnetic  fluctuations during disturbance
   /
586
germagnetic effects of high altitude nuclear explosions  the observations
discussed were made after the two johnston island explosions
effects at the first four observatories are attributed to overhead
currents caused by increased ionization by rays while effects at
apia are explained as being caused by artificial auroras
   /
587
simultaneous recordings in france at the equator and in the antarctic
of magnetic effects caused by the argus experiment  geomagnetic disturbances
were observed at french i  g  y  stations for all three explosions
   /
588
symposium on pulsations and rapid variations in geomagnetism and
earth currents  the text is given of the following papers read at
a symposium in tokyo  a  ionizations in the outer atmosphere inferred
from whistling atmospherics  b  hydromagnetics in the earths outer
atmosphere  c  the acceleration of particles in the outer atmosphere
d  morphology of s s c and s s c  e  some remarks on the morphology
of geomagnetic bays  f  some characters of geomagnetic pulsation
and accompanied oscillation  g  morphology of the germagnetic pulsation
h  particles of aurorae and geomagnetic pulsations  i  hydromagnetic
oscillation of the outer ionosphere and geomagnetic pulsation  j
germagnetic pulsation accompanying the intense solar flare  k  on
the frequency of geomagnetic pulsation  i  studies of the local character
of the geomagnetic pulsation  m  preliminary studies on the daily
behaviour of rapid pulsation
   /
589
micropulsations in the earths magnetic field simultaneous with pulsating
aurora  preliminary results are given
   /
590
hydromagnetic theory of geomagnetic storms  the sudden commencement
of a magnetic storm is attributed to the collision of solar plasma
with the geomagnetic field the disturbance being propagated to earth
by a hydromagnetic wave  the initial positive phase is attributed
te sustained pressure by the plasma the main negative phase by breakup
and diffusion of the plasma which is trapped in orbits in the van
allen belt and the recovery by conversion of trapped protons into
neutral hydrogen
   /
591
rockets and satellites a report on the moscow meetings august  a
report of the technical symposia on rockets and satellites which
formed part of the proceedings of the fifth meeting in moscow
   /
592
artificial earth satellites and space travel part two satellite and
moon probe design  a comparison is made of the design of satellites
and moon probes  and details of their instrumentation are given
   /
593
application of hansens theory to the motion of an artificial satellite
in thn gravitational field of the earth  a numerical theory suitable
for solution by computer which has been applied in the vanguard program
   /
594
reentry of the sputnik rocket
   /
595
decay of spin in sputnik  a secular change in spin fading rate which
occurred during the period october
   /
596
magnetic damping of rotation of satellite  from radio observation
of vanguard i eddy current induction theory gives a value for the
mean magnetic field normal to the spin apis of the satellite
   /
597
geomagnetic rotational retardation of satellite  radio observations
indicated a rapid exponential retardation of satellite rotation
analysis of couples acting on the conducting and magnetic parts of
the satellite gives a value for the mean ambient geomagnetic field
and confirms the eddy current theory applied to vanguawd
   /
598
study of the cosmic ray soft component by the soviet earth satellite
   /
599
measurement of solar and diurnal effects in the high atmosphere by
artificial satellites
   /
600
observations of the russian satellites and the structure of the outer
terrestrial atmosphere  radio and optical observations are analysed
   /
601
the determination of the electron distribution in the upper ionosphere
from satellite doppler observations  by simultaneous reception at
two frequencies one of which is an approximate multiple of the other
a monotonic electron distribution can be determined exactly  the
method is illustrated for sputnik one
   /
602
derivation and analysis of atmospheric density from observations
of satellite epsilon
   /
603
the density distribution in the upper atmosphere  the results of
measurements of atmospheric density made by earth satellites are
plotted as a function of altitude in comparison with curves for two
model atmospheres
   /
604
absorption and electron distribution in the layer determined from
measurements of transmitted radio signals from earth satellites
a comparison is made between measured and theoretically derived values
of field strength of received signals  when the satellite is in the
region of maximum electron concentration and in regions above and
below this level  field strength curves for distances are given
   /
605
measurement of the doppler fizeau effect with artificial satellites
a simple method is described for measuring the doppler frequency
within comparison with the signal from a calibrated oscillator
   /
606
the scintillation of radio signals from satellites  signals from
satellites recorded during a twenty month period are analysed for
evidence of scintillation
   /
607
observations of ionization induced by artificial earth satellites
major enhancements of signals occur before and after the time of
nearest approach  radar echoes which appear to originate at the range
of are discussed
   /
608
energy sources of the upper atmosphere  variable heating of the upper
atmosphere is considered to be caused by electric currents which
are induced by magnetic fields frozen into the corpuscular streams
   /
609
an interim atmosphere derived from rocket and satellite data  a model
atmosphere is proposed for temperate latitudes at altitudes
   /
610
large scale movements of ionization in the ionosphere  an instability
mechanism for deviations in ionization density is suggested for which
the predicted temporal and spatial morphologies appear to be consistent
with those of the occurrence of sporadic spread and radio star scintillations
   /
611
fall day auroral zone atmospheric stu  ture measurements  atmospheric
density and pressure profiles aoe obtained using measurements made
with ro  ket borne ionization gauges
   /
612
a relationship between the lower ionosphere and the night glow emission
correlation is found between the emission and radio echoes obtained
with a ionosonde
   /
613
the electron density distribution in the region of the ionosphere
a theory of electron loss in the ionosphere of is examined in numerical
detail  under certain conditions which are well defined the theory
leads to the type of curve observed in practice for the lower region
   /
614
ionization below the night time layer  using the method described
the low lying ionization for slough and watheroo has been studied
throughout summer and winter nights during periods of maximum and
minimum solar activity  the decay of ionization was consistent with
an effective recombination coefficient
   /
615
travelling disturbances originating in the outer ionosphere  the
vertical velocity component of travelling disturbances coming from
outside and propagation through the ionosphere is determined  oscillation
like phenomena have a large range of quasi periods
   /
616
international symposium on fluid mechanics in the ionosphere  review
and verbatim report of the transactions of a symposium held in new
york  some of the papers presented are listed below others have been
abstracted separately  a  constitution of the atmosphere at ionospheric
levels  b  ionizations and drifts in the ionosphere  c  measurements
of turbulence in the region from the radio echo observations of meteors
d  scattering of waves and microstructure of turbulence in the atmosphere
e  effect of a magnetic field on turbulence in an ionized gas
f  note on some observational characteristics of meteor radio echoes
g  on the spectrum of electron density produced by turbulence in
the ionosphere in the presence of a magnetic field  h  evidence of
elongated irregularities in the ionosphere  i  geomorphology of spread
and characteristics of equatorial spread  j  an interpretation of
certain ionospheric  motions in terms of atmospheric  k  on the influence
of the magnetic field on the character of turbulence in the ionosphere
l  magnetohydrodynamic of the small scale structure of the region
m  electrodynamic stability of a vertically drifting ionospheric
layer  n  turbulent spectra in a stably stratified atmosphere  o
relation of turbulence theory to ionospheric scatter propagation
experiments
   /
617
geomagnetic distortion of the region on the magnetic equator part
two  an extension of work described earlier to study the relation
between diurnal variations of years of different sunspot number and
the phase of germagnetic variations  region distortion is explatned
by vertical ionization drift due to the field extended from the region
   /
618
constant ionosphere height for audio frequency propagation  from an
analysis of smooth type waveforms of a constant height has been estimated
for winter storms  there was no systematic variation with the onset
of night time conditions
   /
619
the use of the extraordinary ray in the analysis of ionospheric records
it is shown that by using the ordinary and extraordinary traces estimates
may be made of the electron content and also the electron density
distribution in the region represented by reflections at frequencies
in the valley between the layers
   /
620
an example of heavy absorption in the v h f band in the arctic ionosphere
observations of meteor echoes and noise from the cassiopeia source
in the band show very heavy absorption in the early morning of july
   /
621
observations of unusual radio frequency noise emission and absorption
the noise enhancements observed during periods of solar activity
are classified as smooth or abrupt  while smooth changes occur in
both day and night hours the abrupt increases are observed only near
local midnight  the smooth enhancements occur almost simultaneously
with the absorption of radiation in a sector of the northern sky
   /
622
hydrogen emission and two types of auroral spectra  various characteristics
of auroral activity including radio reflections have been correlated
with the hydrogen emission
   /
623
auroral ionization and the absorption and scintillation of radio
stars  the absorption of radiation from cygnus when observed at low
latitudes and radar back scatter echoes are related to a layer associated
with auroral activity
   /
624
artificial auroras resulting from johnston island nuclear explosions
   /
625
a daytime maximum of oblique auroral reflexions observed in the auroral
zone  observations made over the period march and june show a daytime
maximum
   /
626
observed characteristics of an ultra high frequency signal traversing
an auroral disturbance
   /
627
a comparison of sferics as observed in the very low frequency and
extremely low frequency bands  the component is almost always followed
by a component of extremely low frequency but about one third of
these components are not preceded by components  positive polarity
wave forms predominant during daytime and their median amplitudes
always exceed those of the negative polarity waveforms which predominate
at night
   /
628
sweepers  sweepers are atmospherics which are present in the h f
many of them occur in trains where the period between successive
sweepers is nearly const nt
   /
629
the propagation of electromagnetic waves in ionized gases
   /
630
more bandwidth for magnetic recorders  details are given of the design
of recorder circuits having a bandwidth to take advantage of recent
increases in recording head response
   /
631
some performance parameters of silicon junction power rectifiers
the temperature dependence of the characteristics of rectifiers
and temperature control in terms of thermal resistance are discussed
a method is given for the calculation of power dissipation and ratings
   /
632
compensation of the effect of temperature on the reference voltage
of transistor stabilized power supplies  the voltage temperature
characteristic of the reference is compensated by that of the base
emitter region of the transistor error amplifier
   /
633
a transductor regulator for stabilized power supplies  a description
is given of a single core full wave transductor circuit and its mode
of operation  a valve type regulator to deal with rapid disturbances
is also described  both regulators are incorporated in a stabilized
power supply
   /
634
economy in the series stabilizer  consideration of the efficiency
of series stabilizer circuits under almost constant load conditions
a resistive shunt to the series element can improve efficiency
   /
635
generators and storage devices for functions of the form  comprehensive
review up to the end of function devices for use in analogue computers
   /
636
relaxation times in lead film superconductive storage elements  an
experiment is described to measure the critical current of a pb film
crowe cell during the first microsecond after switching different
substrates are used
   /
637
ferroresonant systems of circuit logic  characteristics for coupled
inductors are presented and and computer circuits based on these
elements are described with oscillograms illustrating practing operation
   /
638
ferroelectric memory in the parametron circuits  difficulties experienced
in the use of ferroelectric materials in pulse type storage systems
are shown to be partly overcome in parametron circuits  the present
limitation is due to unsuitable ferroelectric materials batio shows
a high fatigue phenomenon and triglycine sulphate a low switching
velocity
   /
639
direct digital conversion of pulse width multiplexed data
   /
640
an analogue elctronic multiplier using transistors as square wave
modulators  the multiplier is designed for high speed operation at
reasonable cost  protection circuits for the transistors are provided
   /
641
indicator triode for direct data read out  the triode combines amplifier
and indicator in one envelope  a triode and transistor bistable circuit
is described with a required input trigger level and also a shift
register in which these circuits are cascaded
   /
642
character generator for digital computers  a monoscope lube apparatus
is described which operates in the speed range of computers and storage
devices and provides read out directly on a c  r  o  or on paper
   /
643
simulation vf inductance by an integrating circuit  an operational
amplifier used as integrator has an inductive input impedance when
a resesthve feedback loop is added between input and output  theoretical
and measured ualues of inductance qfactor and selfcapacitance are
given and the possibility of raising q by positive feedback is examined
   /
644
design considerations for integrated electronic devices  discussion
of fundamental factors affecting the design of integrated electronic
devices with consideration of the effect of shrinkage and methods
of overcoming it
   /
645
printed circuits in radio and television receivers  review of printed
circuit design features in german receivers
   /
646
the climatic fitness of carbon film resistors for use in electrical
communications and measurements  equipment for climatic tests is
described effects observed in resistors subjected to such tests are
discussed
   /
647
coils and transformers under normal room climatic conditions  the
influence of environmental conditions on the operating characteristics
of wire wound components with magnetic cores is investigated  methods
of reducing inductance and q factor changes caused by climatic effects
are considered
   /
648
on the problem of brownian motion of nonlinear systems  a kinetic
derivation is given of the spectral noise intensity in firstorder
approximation and for relatively high frequencies for a nonlinear
rc circuit consisting of an idealized diode valve in thermal equilibrium
and a capacitor  the discrepancy with the rusults obtained by macdonald
   /
649
filter crystals for the frequency range  the requirements for crystals
used in filter networks are considered  for atcut crystals operating
in the range a triangular shape gives a satisfactory reduction of
unwanted modes
   /
650
the stability of negative resistance two poles  stability conditions
are considered on the basis of the static characteristics of the
two pole
   /
651
fundamental and harmonic distortion of waves frequency modulated
with a tingle tone
   /
652
echostant matching a new method of matching image parameter filters
with the type of impedance matching described better matching conditions
are obtained and fewer reactance elements are required than with
the use of double m derived image impedances  the simulation of tchebycheff
type insertion loss and the compensation of losses by ihis method
are also considered
   /
653
unified formulae for filters with tchebycheff type insertion loss
formulae are derived for the determination of zeros and poles of
the transfer function based on the tchebycheff polynomial or on cauer
parameters  the characteristics and treatment of elliptic functions
are discussed and curves are given for relating the insertion loss
requirements to the parameters of the transfer function
   /
654
the image parameter theory as a simple aid to the realization of
crystal band pass filters of branch network type  design formulae
and curves are given for ladder type networks with the crystal in
the shunt arms
   /
655
a new coaxial resonator filter  a band pass filter with an m derived
type of characteristic is described consisting of loop coupled coaxial
resonators in a reentrant arrangement  performance may be described
in terms of an equivalent lattice network  good agreement is shown
between the experimental and theoretical insertion loss characteristics
   /
656
analysis of active networks by admittance matrices  admittance matrices
of valves and transistors are derived directly and from their indefinite
admittance matrices
   /
657
considerations on oscillator stability  methods of reducing microphony
effects and temperature dependence of oscillators in television tuners
   /
658
a procedure for tuning a bridge stabilized crystal oscillator  a
meacham bridge circuit is used in which the lamp is replaced by a
thermistor and a second thermistor is added to compensate for ambient
temperature fluctuations  a sensitive method of tuning input and
output transformers in this circuit is described
   /
659
theoretical investigation of a tuning procedure for bridge stabilized
crystal oscillators  the tuning method described above is analysed
   /
660
pulse generator for the production of a spectrum with constant amplitude
in the frequency range  the equipment described conforms to the german
specifications for radio interference measuring sets  five different
pulse repetition frequencies can be selected in the range
   /
661
on the regenerative pulse generator  an analysis of the mus pulse
generator of cutler as a multimode oscillator
   /
662
direct digital conversion of pulse width multiplexed data  pulse
width data are converted to a binary form by relating the incidence
of leading and trailing pulse edges to the state of a counter driven
by an asynchronous oscillator
   /
663
a further method of coupling loudspeakers to a so called transformerless
push pull output stage  in the single ended push pull circuit described
two pairs of series connected loudspeakers or loudspeaker groups
are connected across screen grid and anode of the output pentodes
   /
664
parallel connected magnetic amplifier  a mathematical analysis of
parallel connected magnetic amplifiers with an inductive and capacitive
load is presented  the analysis is based on the representation of
the normal magnetization curve of the core material by polynomials
of thiod and fifth degree respectively
   /
665
the dynamic hysteresis loop as a cause of the free demagnetization
in magnetic amplifiers  self demagnetization effects are considered
with reference to a hysteresis loop modified as a result of eddy
current losses
   /
666
design of transistor i  f  amplifier detector stages with stabilized
band pass characteristics  an extension of work described earlier
   /
667
junction transistor circuits  a method is described for calculating
current drift due to changes of junction temperature in a direct
coupled transistor circuit with series negative feed ba  k  the design
of drift compensating circuits is considered and a brief comparison
is made with parallel feedback circuits
   /
668
the noise and gain properties of molecular and parametric amplifiers
analysis is sufficiently general to include both types of amplifier
as special cases  the concepts of negative noise temperature and
negative quality factor are introduced by analysing the energy exchange
between a general sample of masser and a quantized cavity field
the three level maser of bloembergen and the ferrimagnetic amplifier
of suhl are discussed in some detail
   /
669
the present state of solid state molecular amplifiers  the principles
and properties of solid state masers with two and three energy levels
are discussed  recent developments and future applications are considered
   /
670
operating characteristics of a molecular beam maser  general expressions
for the emitted power and the frequency pulling in an ammonia maser
have been deduced  the operating  characteristics of the maser have
been deduced by introducing a mean square time of flight of molecules
in the cavity
   /
671
ammonia maser oscillator  the principle of operation and constructional
details of an ammonia maser are described  four parameters affecting
the frequency of operation have been investigated ammonia flow separator
voltage magnetic fields and cavity tuning
   /
672
noise temperature measurement on a travelling wave maser preamplifier
   /
673
pulsed field millimetre wave maser  the frequency range of the pulsed
field ruby maser has been extended and the peak output power has
been increased to several mw
   /
674
submillimetre wave maser
   /
675
some possible arrangements of parametric amplifiers employing lower
frequency pumping  two arrangements are analysed in desail a  combination
of a mixer and an amplifier using one pump and two idlers b  combination
of a mixer and an amplifier using two pumps and two idlers
   /
676
theory of the travelling wave parametric amplifier  the theory is
based on a nonlinear distributed capacitance excited by a travelling
wave  losses in lhe capacitance and the effects of saturation on
large signals are considered
   /
677
saturation effects in a travelling wave parametric amplifier  equations
of voltage distribution are solved in terms of elliptic functions
and an expression for the maximum power gain is derived  the positions
of gain maxima are calculated
   /
678
theory of fast wave parametric amplification
   /
679
a microwave adler tube
   /
680
double push pull modulator with valves
   /
681
rectifier modulators  a method for reducing the complexity of equations
for the series rectifier modulator without undue loss of accuracy
is postulated  the simplified equations are shown to be soluble by
successive approximations  the process is applied to a modulator
with a  constant resistance termination b  purely capacitive termination
   /
682
the frequency modulation of tuned circuit and relaxation oscillators
the problem of distortionless frequency modulation of oscillators
for any modulating frequency is considered  the conditions for an
ideal nonlinear frequency modulator are formulated and aoolied to
the constant amplitude and relaxation oscillator
   /
683
classical electrodynamic equations of motion with radiation reaction
a physically reasonable solution for the equations exists for any
force field that satisfies certain conditions
   /
684
sauter theory of the photoelectric effect  the photoelectric effect
cross section for arbitrary x ray polarization and arbitrary initial
and final orientations of electron spin is expressed in the form
of a transition matrix  approximation shows its relation to bremsstrahlung
theory
   /
685
higi frequency limit of bremsstrahlung in the sauter approximation
the photoelectric process is shown to be inverse to the process of
x ray emission at the high frequency limit of the spectrum
   /
686
interference of orbital and spin currents in bremsstrahlung and photoelectric
effect  interpretation of angular distribution x ray polarization
and spin orientation in terms of interference between orbital and
spin currents
   /
687
bremsstrahlung and the photoelectric effect as inverse processes
a detailed theoretical examination of the inverse processes of the
photoelectric effect and of bremsstrahlung at the high frequency
limit of the spectrum
   /
688
the motion of an electron in a crystal located in an external field
extension of an earlier analysis to the case of uniform magnetic
and arbitrary electric fields
   /
689
exclusion factors in transport theory
   /
690
the problem of the optical constants of conductors  a mathematical
analysis showing that the optical constants of an isotropic conductor
comprise in addition to the index of refraction and of the absorption
coefficient two real quantities corresponding to a complex boundary
impedance  the real part of this boundary impedance represents the
surface losses in the conductor and the imaginary part of the dielectric
constant the volume losses
   /
691
high current superconductivity  the barden cooper and schrieffer
theory of superconductivity is extended to the case of high current
densities by explicitly including in the phonon induced electron
electron attraction the modification of the phonon spectrum in a
moving coordinate system  this modification results from the doppler
effect
   /
692
investigation of the high frequency spectrum of periodic discharges
the frequency spectrum of h  v  corona pulse discharges is investigated
   /
693
electric field in a microwave plasma as a function of time  investigation
of the transient state in a pulsed discharge in deuterium at pressures
field strength was determined bi an optical method of noting
the stark effect on the balmer lines in the external oscillating
field
   /
694
the plasma capacitor  the measurements of dattner on a plasma resonator
are discussed
   /
695
electron temperature in electrodeless discharge subjected to a transverse
magnetic field
   /
696
ion energies in a cold cathode discharge in a magnetic field  the
current flow after a discharge revealed an approximately maxwellian
distribution of velocities at the cathodes with a temperature  this
gives an ion density in the discharge
   /
697
microwave study of afterglow discharge in water vapour  electron
loss processes prevailing in decaying water vapour plasmas are interpreted
   /
698
possibility of determining the potential distribution of a plasma
from the characteristics of the noise generated in a gaseous discharge
a note of noise measurements made on oxide cathode discharges in
krypton at pressures and at discharge currents  the variation of
potential along the axis of the discharge is in close agreement with
results obtained by conventional probe methods
   /
699
scattering potential in fully ionized gases  a discussion of recent
methods for calculating a  the scattering potential and b  the probability
that a test particle experiences an electrical field of magnitude
   /
700
the stability of plasma configurations of cylindrical symmetry with
volume currents  the stability is investigated by the method of small
perturbations
   /
701
energy losses of charged particles due to excitation of platma oscillations
a kinetic equation is derived describing the interaction between
beam elements and plasma under equilibrium conditions  for non equilibrium
conditions a nonlinear theory of plasma oscillations excited
by an electron beam is developed and results are applied to account
for the rapid energy transfer from the beam
   /
702
collision damping of space charge waves in a plasma  the general
determinantal equation applicable to the propagation of space charge
waves including the effect of collisions in the absence of a velocity
distribution in a plasma is derived  suggestions arising from the
solutions are discussed
   /
703
absorption and reflection spectrum of a plasma  a re evaluation of
the experimental results of rommel and dattner and a development
of theory to account for additional resonance peaks
   /
704
penetration of an electromagnetic field into a plasma  calculation
of the penetration depth for a semi infinite plasma located in a magnetic
field perpendicular to the plasma boundary
   /
705
incoherent microwave radiation from plasmas  a study of incoherent
radiation from an isotropic qxiscent plasma of a low degree of ionization
the three cases of transparent semi opaque and opaque plasmas
are considered theoretically  good experimental agreement is obtained
xsing d  c  glow discharges in helium and hydrogen
   /
706
microwave determination of plasma density profiles  a method for
the rapid determination of the average electron density and of the
spatial electron density distribution in plasmas is presented  the
technique employed permits time resolved measurements over a wide
range of electron densities introducing little or no perturbation
into the gaseous discharge
   /
707
structure of a magnetohydrodynamic sho  k wave in a partially ionized
gas  an approximate solution of the equation for the transition zone
is given for some special cases
   /
708
the structure of hydromagnetic sho  k waves part one nonlinear hydromagnetic
waves in a cold plasma  waves in a quasi neutral gas consisting
of ions and electrons are investigated neglecting collisions but
not the inertial effects of the electric current  the relation of
these waves to hydromagnetic shock waves in low density plasmas is
considered
   /
709
electromagnetic properties of high temperature air  if the parameters
are normalized the e  m  characteristics of plasmas can be represented
in a universal form in the complex dielectric coeficcient plane or
the complex propagation constant plane
   /
710
fine structure in the decline of the ferromagnetic resonance absorption
with increasing power level  a theory of ferromagnetic resonance
at high signal powers is developed which accounts quantitatively
for observed effects
   /
711
on the phenomenological theory of the voigt effect in paramagnetics
a microscopic calculation of the voigt effect in paramagnetic media
at centimetre wavelengths
   /
712
influence of exchange interaction on paramagnetic relaxation times
   /
713
relaxation effects in a maser material  the rate equations for the
occupation of spin levels are augmented to include cross relaxation
processes which can impair maser action
   /
714
radiation produced by an electron beam passing through a dielectric
medium  an electron beam passing through a dielectric medium may
produce an instability that is associated with the growth of longitudinal
waves having a velocity close to the velocity of the beam  if
homogeneities are present these longitudinal waves may be converted
into transverse waves and radiated into space  thus there is a possibility
of a luminous effect at bohr frequencies that differ from the
vavilov cherenkov frequencies
   /
715
on the doppler effect in an anisotropic and gyrotropic medium  investigation
of the doppler effect during the motion of an oscillator along
the axis of a gyrotropic anasotropic crystam  expressions are derived
for the radiation energy applicable to the cherenkov radiation field
of an electron and of a dipole
   /
716
the increase ie frequency bandwidth of thin four layer absorbers
for centimetre electromagnetic waves  a type of absorber is investigated
which can be made thinner than one thirty of the wavelength in free
space  if the dielectric constant or permeability of the lossy material
is independent of frequency the effective bandwidth of the absorber
decreases with absorber thickness  to obtain a thin absorber covering
a frequency range of ratio one  two  bielectric constant or permeability
would have to follow a frequency law of the type given but no practical
material is known which meets these requirements
   /
717
a note on diffraction by an infinite slit  previous results for plane
waves at longer wavelengths are extended to obtain transmission coefficients
at oblique angles of incidence  cylindrical waves are considered
briefly
   /
718
diffraction by a spheroid  the diffracted field is determined by
two methods for wavelengths small compared to the spheroid  results
are applied to evaluate the back scattered fields
   /
719
investigations on artificial dielectrics at microwave frequencies
part two  the expression for the phase change in transmission of
an e  m  wave incident on a parallel plate type artificial dielectric
as a function of the plate spacing has been verified experimentally
   /
720
on the reflection of electromagnetic waves from a medium excited
by acoustic waves  theory is developed for the variation of density
and temperature in a liquid caused by an acoustic wave generating
regions of maximum and minimum dielectric constant  modulation of
a wave reflected from an acoustically disturbed water surface is
observed
   /
721
confinement of charged particles by plane electromagnetic waves in
free space  confining forces associated with nonuniform fields are
shown to occur when twr plane waves intersect in free space
   /
722
nuclear resonance absorption circuit  the principles of detecting
nuclear resonance absorption in a specimen surrounded by a coil forming
part of a tuned circuit are discussed in detail and various methods
are compared  a new circuit is described and two practical designs
are given for operation
   /
723
correlation effects in impurity diffusion
   /
724
the shielding of a fixed charge in a high density electron gas  a
corsed expression for the density of displaced electrons is derived
by a systematic application of the many body perturbation theory
   /
725
magnetoplasma reflection in solids  the splitting of the reflection
edge at the plasma frequency in the presence of a magnetic field
has been used to measure the effective mass of the electrons
   /
726
development of highly directive aerials in radio astronomy
   /
727
on the long term variation in the cosmic radiation  the variation
seems to occur in a series of sudden decreases rather than gradually
a possible solar modulating mechanism is discussed
   /
728
decrease of cosmic ray intensity on february  the sudden decrease
followed by a temporary recovery is attributed to disordering of
the outer geomagnetic field by the increase of the solar wind
   /
729
geomagnetic effects on cosmic radiation for observation points above
the earth  stormer and lemaitre vallarta theories of the principal
shadow cone have been adapted for observational points above the
earths surface
   /
730
question of the existence of a lunar magnetic field  a lunar magnetic
field would be distorted by solar corpuscular radiation  on the sunlit
side it would not extend to high altitudes and would be difficult
to detect
   /
731
observations on the general solar plasma instability  suggestions
are made for satellite experiments during occasional very intense
solar streams to determine the nature and geometry of the plasma
barrier
   /
732
a relationship between the life of m regions and the rate of change
of solar activity  an inverse relation is established between the
rate of decay of the cycle of solar activity and the lifetime of
m regions as manifested by the persistence of recurrence of magnetic
storms
   /
733
small effects of solar flares and the energy spectrum of the primary
variation of cosmic rays  investigation of the relation between small
solar flares and the intensity of cosmic oay neutrons at four stations
at different latitudes
   /
734
survey of number of solar flares observed during the international
geophysical year  the i  g  y  flare data show a very high rate of
occurrence  many of these flares would probably have been classified
as subflares by photographic observers
   /
735
motion of geomagnetic field lines  motion of the impact regions of
the upper atmosphere can only be very slow since the high conductivity
of the earths interior limits the field distortion this is at variance
with the hypothesis of rees and reid
   /
736
current systems in the vestigial geomagnetic field explorer sixth
the results indicate the existence of a temporally variable current
system at earth radii
   /
737
some  characteristics of the upper air magnetic field and ionospheric
currents  magnetic scalar intensity from rocket data is compared
with that derived by extrapolation from the surface vector field
the agreement is good for equatorial regions but is only fair for
white sands new mexico
   /
738
a radial rocket survey of the distant geomagnetic field
   /
739
fluctuations in the geomagnetic horizontal field near the magnetic
equator  earlier work is continued to cover the diurnal characteristics
of fluctuations and to examine how they compare with fluctuations
due to solar flare effects
   /
740
occurrence frequency of geomagnetic micropulsations pc  analysis
of the diurnal occurrence frequency shows that a  the frequency increases
and time of maximum occurrence gets earlier as the turoral zones
are approached b  the diurnal distribution of frequency depends on
universal time as well as local time
   /
741
a giant geomagnetic pulsation  the characteristics of the event of
july are studied from magnetograms recorded at a large number of
european observatories  observed effects are compared with existing
theories of the cause of gians pulsations
   /
742
on the theory of giant pulsations  a mathematical analysis of the
propagation of a magneto ionic disturbance originating in the exosphere
shows that only the rotational movement perpendicular to the geomagnetic
field is propagated without great loss of energy  the observed characteristics
of giant pulsations suggest that they are mainly caused by
this rotational component of the primary disturbance
   /
743
geomagnetic storm theory  the penetration of solar ions into the
geomagnetic field during the main phase of storms is discussed  a
model is suggested the principal feature of which is a magnetic tail
extending from the earth on the dark side  this model would help
to explain the gegenschein electrons with auroral energies the position
of the van allen zones and diurnal cosmic ray variations
   /
744
the simultaneity of sudden commencements of magnetic storms  geographic
analysis of magnetograms shows that a  sudden commencements always
occur first in high or middle latitudes b  the average values of
their apparent propagation velocity round the magnetic equator
   /
745
charge and magnetic field interaction with satellites  when satellite
motion is parallel to a magnetic field the satellite will become
negatively charged to a potential  for motion perpendicular to the
field this will be modified by an induced e  m  f  which may be as
large as per metre of satellite length  the drag caused by induced
currents is found to be negligible except for very large satellites
   /
746
satellite orbits in an oblate atmosphere
   /
747
variation of upper atmosphere density with latitude and season  further
evidence from satellite orbits
   /
748
atmospheric tides and ionospheric electrodynamics  a semi empirical
treatment of winds in the height range showing their dependence on
latitude and height  the extension of modern tidal theory into the
dynamo region is discussed
   /
749
electron density of the ionosphere utilizing high altitude rockets
   /
750
the comparison method of the station lindau harz for the determination
of the true distribution of electron density in the ionosphere  an
extension of the method described earlier is discussed  the advantages
of using the extraordinary ray traces for comparisons are shown
details are given of the method of calculation and the equipment
used for analysis the tables included are calculated for a geomagnetic
inclination
   /
751
group refractive index of the ionosphere at low frequency  a general
expression for the group refractive index at l  f  is obtained which
for the limiting case when electron collisional frequency is small
is identical with an approximate expression due to gibbons and rao
   /
752
a theoretical current density ansatz for the quiet day solar semidiurnal
tidal mode of oscillation of the ionosphere  theoretical expressions
which embody the generalized atmospheric dynamo mechanism of the
origin of upper atmospheric current systems are derived for the current
density vector  by numerical integration methods approximate expressions
may be obtained for the current density over an ionized shell concentric
with the earth
   /
753
use of greens function in the solution of ionospheric diffusion problems
the mathematical analogy between diffusion of ions in the ionosphere
and heat conduction in a rod is used to solve the problem of diffusion
with an attachment type law of electron loss
   /
754
diffusion of ions in a static f region  the vertical diffusion of
ions under the action of gravity and a rate of electron loss which
decreases exponentially with height is shown to correspond to heat
conduction in a rod with a heat source distribution and radiation
from the lateral surface  electron density is determined as a time
periodic function of the height and is expressed in the form of an
infinite series
   /
755
a model of the f region above h f  the electron density distribution
above the f layer maximum is approximated using a chapman distribution
the scale height has been chosen to agree with the sparse data available
for this region  this approximation has been used to extrapolate
vertical incidence ionospheric data for a chain of observatories
   /
756
correlation of spread f activity with f region height changes  the
analysis employs a new index of spread f activity suited to equatorial
phenomena
   /
757
ionospheric effects associated with the solar flare of july  report
of observations made in singapore of ionospheric effects associated
with the flare  a positive pulse in the measured values f similar
to that studied by minnis and bazzard was observed immediately after
the period of high absorption
   /
758
variation of electron density in the ionosphere with magnetic dip
extension of work described earlier to include the northern winter
solstice  results show a sharp maximum in the average electron density
   /
759
the electron content and distribution in the ionosphere  electron
content and distribution are determined from an analysis of measurements
of the faraday rotation rate on transmissions received near colombus
ohio
   /
760
some observations of ionospheric faraday rotation  a comparison with
vertical incidence ionosonde data suggests that the ratio of the
electron contents above and below the level of maximum ionization
of the f region does not remain constant between sunrise and noon
   /
761
measurement of the ionospheric absorption at ahmedabad  the mean
monthly values of the absorption plotted against cos x for each month
from august to july obeyed a relation of the type log  the results
are in agreement with those obtained by appleton and piggott
   /
762
on the rotation of the polar ionospheric regions  the depth to which
the drag of the interplanetary gas might be expected to penetrate
is examined  levels as low as the e region may be involved
   /
763
the thermal radio emission of the ground and the atmosphere and its
influence on aerial nrise  the measurements of radio noise discussed
were made with the radio telescope on the stockert  a radio image
of the horizon is obtained from the thermal emission and compared
with the optical image
   /
764
the electrical sandstorm and related phenomena  the mechanism of
electrical charge generation in sandstorms and volcanic eruptions
is discussed with reference to thunderstorm phenomena  the world
wide distribution of thunderstorms is examined and related to the
distribution of land masses over the globe and to the daily fluctuations
of atmospheric electricity
   /
765
polar auroral geomagnetic and ionospheric disturbances  an integral
invariant of auroral particle motion which appeared to predict successfully
features associated with auroral isochasms
   /
766
the nightly variation of auroras at a subauroral station  the maximum
frequency of auras occurs near local magnetic midnight  the problem
of particle bombardment on the dark hemisphere is considered
   /
767
doppler shifted cyclotron frequency radiation from protons in the
exosphere  these protons are a possible source of v  l  f  dawn chorus
and hiss  making reasonable assumptions regarding the physical processes
in the outer ionosphere theoretical dispersion curves are obtained
which are similar to those observed
   /
768
observations on atmospheric radio noise  observations made at camden
n  s  w  show that the start of noise bursts usually coincides with
bay like variations in the magnetic field
   /
769
correlation of occurrence of whistlers with geomagnetic activities
the frequency of occurrence of whistlers has a seasonal variation
upon which are superposed daily variations which reach a maximum
on the second day after a geomagnetic disturbance
   /
770
thermoelectric temperature stabilization of electrical circuit elements
the application of the peltier effect to the cooling of semiconductor
rectifiers and transistors is discussed
   /
771
low noise electronic voltage stabilizers with low internal resistance
the design of low output impedance stabilizers for voltages
   /
772
an eight digit word generator  the theory of operation and the design
of a binary word generator using surface barrier transistors and
a direct coupling technique are given
   /
773
solving noise problems in digital computer memories  details are
given of a coincident current storage system in which strobe pulses
are obtained directly from driven cores
   /
774
optical analogue computers  a general theory of optical analogue
computers based on characteristics of the photographic process is
developed and applications of photosensitive materials and photocells
for performing mathematical operations are reviewed
   /
775
integrated magnetic circuits for synchronous sequential logic machines
two approaches to the problems of storage gain and unidirectional
transfer of a sequence of bits in a system with a minimum of nonmagnetic
components are outlined  examples are given of experimental synchronous
sequential circuits using commercially available multiaperture cores
   /
776
computer switching with high power transistors  a method for selecting
the most suitable type of power transistor for particular switching
applications is given
   /
777
the digitron a cold cathode character display tube
   /
778
an analogue computer for investigating the directivity characteristics
of complex arrays of unit aerials
   /
779
an approximation to the harmonic response of saturating devices
an exponential curve is used to approximate the system characteristics
   /
780
electrical and thermal relaxation effects in current carrying metallic
conductors  the a  c  admittance of conductors carrying d  c  is
calculated and a relation is found for determining the frequency
dependent thermal conductivity  results of measurements on lamp filaments
confirm this relation
   /
781
some results on the cross capacitances per unit length of cylindrical
three terminal capacitors with thin dielectric films on their electrodes
the concept of power at complex frequencies  the significance of
the term negative resistance is discussed with regard to two different
aspects  one is the behaviour of twopole networks with sinusoidal
oscillators and a negative slope characteristic the other is the case
of exponentially decaying oscillations where phase shifts greater
between current and voltage may arise
   /
782
a method of synthesis of linear passive networks for transient conditions
a method of synthesis is described for networks wrth transient
response of unit function or dirac function type
   /
783
frequency jumps and pulling effects in coupled circuits  the admittance
equations for two coupled tuned circuits are formulated and the conditions
of oscillation established  the minimum width of the frequency
jump is derived as a function of coupling and in relation to the
pulling properties of the oscillator  the limiting conditions for
freedom from frequency jumps are given
   /
784
the optimization of a class of nonlinear filters  a mathematical
treatment shows that use of the nonlinear filter gives a significant
improvement in mean square error even when signal and noise have the
same spectral densities  optimization is not unduly difficult
   /
785
the influence of the time dependent series resistance of a capacitance
diode in a mavar up converter  an amplifying frequency converter
for conversion is investigated theoretically  the variable reactance
is a semiconductor diode of the type described by uhlir  the effect
of the loss resistance of this diode on converter stability and band
width is evaluated
   /
786
dual frequency oscillator design  basic design details are given
of circuits in which hartley and colpitts oscillators are combined
   /
787
simultaneous oscillation at three natural frequencies in nonlinear
feedback circuits  the steady states of a nonlinear feedback loop
with three degrees of freedom are investigated under the assumption
of quasilinearity with reference to the theory of multimode oscillators
experimental results and practical applications of the effect are
discussed
   /
788
transfluxor oscillator gives drift free output  a voltage controlled
transistor multivibrator circuit incorporating a transfluxor magnetic
core is described a feature of the arrangement is the stability of
the output frequency after removal of the control signal
   /
789
a simple pulse generator and a pulse distribution unit using transistors
circuit and performance details are given of equipment for use
rn television studio installations
   /
790
time to pulse height converter of wide range  the converter is designed
to plug in to commercial oscilloscopes and can time several events
per time scan relative to one starting event  counting losses can
be reduced by negative time scanning  the circuit diagram is given
   /
791
fast coincidence circuit for slow pulses  for pulse timing particularly
in coincidence spectroscopy applications
   /
792
practical decimetre wavelength harmonic generator  a frequency stable
coaxial type harmonic generator is described whose design is based
on the rod wavemeter  four patterns are available covering different
fundamental wavelength ranges the highest usable harmonic frequency
   /
793
harmonic generation using idling circuits  a theoretical examination
of the conditions necessary for efficient harmonic generation using
an element with a square law characteristic
   /
794
tunnel diode as an interstage gain device  application of the tunnel
diode as a coupling element to provide impedance transformation and
power gain between each stage of an i  f  amplifier
   /
795
distortion in class ab push pull amplifiers  fourier coefficients
of the current waveform for a single valve or transistor working
under varying bias conditions are evaluated as a function of the
angle of flow of the output current  from these results the harmonic
distortion is determined for a balanced push pull system and it is
shown that small degrees of unbalance can be responsible for large
contributions to the overall distortion principally by the introduction
of second harmonics
   /
796
compensation of direct coupled amplifiers against drift caused by
heater voltage fluctuations  the output from a thermopile heated
from the source which supplies the valve heaters of an amplifier
is fed back either to the input or to the indicator to compensate
for zero drifts  the drift is reduced by two thirds without loss
of amplifier sensitivity
   /
797
self balancing push pull circuits  theoretical aspects of self balancing
circuits are discussed and a method is described for making a push
pullamplifier self balancing by applying overall push push negative
feedback no close tolerance components are needed
   /
798
the new isodyne phase splitter  details are given of an amplifier
in which the phase splitter is directly coupled and the output to
the final stage is taken from a cathode follower
   /
799
unity gain amplifier offers high stability  design equations are
given for a double triode output stage the gain stability factor
of which is the reciprocal of the products of the two gains
   /
800
an overmodulation effect in negative feedback valve amplifiers  if
the final stage of a multistage rc coupled feedback amplifier is
driven into grid current through over loading there is a difference
between the input levels at which grid current sets in and that at
which it ceases  the distortion caused by this effect is investigated
measures to eliminate it are discussed but are not considered worth
undertaking for multichannel carrier systems
   /
801
temperature stabilization of transistors in class b amplifiers  factors
affecting stability are discussed and a graphical method is described
for estimating the maximum temperature for stable operation  experimental
results obtained using a thermistor to improve stability are in
good agreement with theory
   /
802
transistor circuit design using modified hybrid parameters  methods
are described for calculating modified hybrid parameters and approximate
expressions applicable to the design of practical one and two stage
amplifiers with feedback are given
   /
803
masers or parametric amplifiers  the main features of the various
types of amplifiers in each group are summarized and their relative
performance in practical systems is discussed
   /
804
on the theory of masers  preliminary note dealing with the effects
of phase distribution in the microwave field
   /
805
on the possibility of maser action in nuclear quadrupole systems
   /
806
operation of a chromium doped titania maser  brief description of
a maser which has been operated at several frequencies
   /
807
parametric amplification along nonlinear transmission lines  a pump
signal propagating along a dispersionless transmission line with
a distributed nonlinear capacitance is subject to deformation since
different parts of the signal move with different velocities  the
deformation will affect the parametric amplification process so that
in general a sinusoidal will not be increased inits fundamental frequency
bi travelling down the line
   /
808
extension of longitudinal beam parametric amplifier theory
   /
809
note on the noise figure of negative conductance amplifier  the noise
figure is calculated for the case when the negative conductance amplifier
stage is connected directly to a receiver and when it is connected
via a lossless step down transformer
   /
810
noise performance theory of esaki tunnel diode amplifiers  theory
indicates that low noise figures can be achieved only with some sacrifice
in gain stability or bandwidth
   /
811
thin film balanced modulator  passive balanced modulator circuits
are evolved using single domain permalloy film which is vacuum deposited
in a magnetic field
   /
812
the use of silicon diodes in d  c  modulators and their applications
to drift correctors for computing amplifiers  advantages over the
conventional relay modulator include good high frequency response
low noise level low switching power requirements and an operational
life limited only by the thermionic valves  zero stability is comparable
wite that of the conventional relay
   /
813
explicit form of f  m  distortion products with white noise modulation
expressions are derived for frequency and amplitude distortion of
the output of a network whose phase or amplitude characteristics
vary nonlinearly with frequency  the evaluation of these expressions
using a digital computer is illustrated for the case of fourth order
distortion associated with terms in the discriminator amplitude characteristic
up to the sixth degree
   /
814
frequency modulation of a transmitter by inductance variation  the
use of a ferrite cored variable inductor is proposed and its advantages
over a reactance valve circuit are discussed  an experimental f
m  master oscillator is described
   /
815
the single ended diode phase sensitive detector  the transform ratios
for the two diodes are found to vary with signal level  the nonlinearity
in the output is evaluated and a table is given for assessing
the performance of a given detector
   /
816
theoretical considerations on the experimental determination of spontaneous
photon fluctuations  a method is indicated for measuring fluctuations
with a suitable photon detector
   /
817
theory and application of thermally stimulated currents in photoconductors
explicit solutions are obtained in the limits of slow and fast
retrapping  a method of obtaining the ionization energy of the relevant
traps is discussed
   /
818
photon momentum effects in the magneto optics of excitons  two magneto
optic effects due to the small but finite wave vector of light are
described
   /
819
an approximation method for the treatment of spherical aberration
of objectives using the methods of communication theory  the surface
of the objective is divided into zones and a simple formula is derived
for evaluating the brightness distribution in the image plane
   /
820
charged sphere in cylinder  the charge density potential and capacitance
of the sphere are calcuotential and capacitance of the sphere are
calculated to an accuracy within one part in ten using the method
described earlier
   /
821
wave functions and effective hamiltonian for bloch electrons in an
electric field
   /
822
transport phenomena in elastically anisotropic metals
   /
823
statistical theory of kinetic phenomena  general expressions are
derived for kinetic coefficients which are used to obtain approximate
formulae for the case of weak electron phonon inter action  the derived
formulae are used for investigating the thermoconductivity and thermo
e  m  f  of semiconductors
   /
824
a dielectric approach to impurity conduction  the problem of impurity
conduction in valence crystals is formulated on a dielectric basis
calculations are made of a  the contribution to the permittivity
arising from the hydrogenic donor atoms b  the donor activation energy
and c  the effect of screening by conduction electrons
   /
825
on the theory of superconductivity  an exact treatment of the strong
coupling approximation in the theory of bardeen et al and discussion
of the meissner effect
   /
826
development of space charge and growth of ionization in the transient
townsend discharge  an extension of earlier work
   /
827
cathode work function sparking potentials and secondary ionization
coefficients for oxide coated cathodes in hydrogen  the contact potential
difference between oxide coated cathodes and a gold reference
surface has been measured using the kelvin technique
   /
828
influence of the cathode work function on the sparking potential
in hydrogen  the kelvin vibrating electrode method of measuring contact
potential differences has been used to follow changes in work function
of evaporated metallic films in a parallel plate electrode system
in hydrogen
   /
829
ultimate and secondary electron cold cathode discharge in helium
   /
830
equation of state of high temperature plasma  fully ionized plasmas
at high temperatures are investigated on the basis of quantum theory
and a correction to the debye huckel approximation is evaluated for
the free energy and the equation of state
   /
831
electron and ion runaway in a fully ionized gas part two  an extension
of the treatment presented in part one to give a more exact estimate
of the runaway rate under the action of a weak electric field
   /
832
electron velocity distributions in a partially ionized gas  investigation
of the transition from the non maxwellian distribution characteristic
of a poorly ionized gas to the maxwellian distribution as the degree
of ionization rises
   /
833
plasma containment by r  f  and d  c  field combinations  the advantages
are discussed of supplementing d  c  with r  f  fields which are
sometimes more effective and possibly more stable  the design of
r  f  plugs for sealing the ends of a plasma column contained by
a d  c  magnetic field is given in some detail
   /
834
propagation of plasma waves across a density discontinuity  when
longitudinal waves are incident on a plasma density or temperature
discontinuity energy can be converted to transverse waves  the inverse
process also occurs
   /
835
radio emission by plasma oscillations in nonuniform plasmas  equations
of motion for small amplitude plasma oscillations interacting with
the e  m  field in slowly varying density or temperature gradients
are established  the r  f  noise excited by a wave packet of plasma
oscillations traversing such gradients is calculated using the wkb
approximation  a similar calculation is made for a density discontinuity
   /
836
the radiation emitted within ionized gas in the presence of a magnetic
field
   /
837
electrohydromagnetic waves in a fully ionized gas part one  transport
equations are used to determine coefficients which are generalizations
for any frequency of electric field of the parallel pedersen and
hall conductivities  applications are discussed
   /
838
potential distribution between two plane emitting electrodes  equations
are derived for two plane parallel electrodes made from different
materials and kept at different temperatures  numerical calculations
are given for electrodes at the same temperature with an external
potential difference between them  all possible potential distributions
are shown to be represented by a family of curves
   /
839
theory of spin wave interactions in ferro and antiferro magnetism
mathematical treatment of spin wave theory for a ferromagnetic model
giving results in agreement with dysons
   /
840
geometrical representation of the maxwell field in minkowski space
the electromagnetic field tensor of a classical charged particle
is associated with the orientation and density of a family of two
dimensional surfaces radially distributed about the world line of
the particle in minkowski space
   /
841
on the production of high intensity magnetic fields of short duration
the design of capacitor discharge apparatus for pulsed fields is
discussed  calculations are compared with experimental data for coils
producing fields
   /
842
production of very high magnetic fields by implosion  fields in the
ten fifteen mg range are obtained by use of high explosives which
effectively compress the flux inside a metallic cylinder
   /
843
microwave whistler mode propagation in a dense laboratory plasma
the thermonuclear machine zeta at harwell is being used for plasma
diagnostics  measurements of refractive index and attenuation rate
at two frequencies will be attempted
   /
844
focusing molecular beams of nh  a study of the formation of molecular
beams for use in nh masers is described  the design and performance
of nonuniform focusers and of effusers is considered  the operation
of a system is described in which lower state molecules produced by
maser oscillation may be detected
   /
845
molecular beam formation by long parallel tubes  the characteristics
of molecular beams formed by sources consisting of long tube arrays
are measured for several sources  the results agree well with theory
some considerations in source design are also discussed
   /
846
analysis of focuser for maser oscillators  a mathematical study of
the characteristics of eight pole four pole and square well focusers
the main conclusions refer to the focusing length and the influence
of the velocity distribution in the beam
   /
847
on the possibility of maser action in nuclear quadrupole systems
analysis of an apparently promising system shows that the gain in
the material is not sufficient to overcome circuit losses
   /
848
allowed and forbidden regions in the motion of electrically charged
particles in axially symmetric magnetic fields  diagrammatic methods
are applied to the case of motion in the field of a magnetic dipole
and of a circular line current
   /
849
the motion of charged particles in the magnetic field of a straight
current carrying wire  the calculated velocity of a particle in the
field along an infinitely long wire is in agreement with alfvens
approximation
   /
850
quantum theory of transport in a magnetic field
   /
851
comparison of the charges of the electron proton and neutron  experimental
details are clarified in reply to criticism by bondi and lyttleton
   /
852
systematic study of electron binding energies of some fourth and
sixth period elements by means of the photo electron method
   /
853
theory of internal field emission  difficulties in the solution of
the schrodinger equation in the quantum mechanical treatment of internal
field emission are avoided by the use of bloch functions instead
of those based on houstons theory
   /
854
on the magnetic field of the galaxy
   /
855
on the interplanetary gas and its magnetic field  proposed models
of the interplanetary magnetic field are critically examined in relation
to known physical phenomena
   /
856
existence of net electric charges on stars  this hypothesis accounts
for the known orders of magnitude and directions relating to a number
of phenomena such as the magnetization of the earth and the outer
van allen belt and leads te a simplle qualitative or semi quantitative
explanation for others  possible sources of the stellar net charge
and possible criticisms of the hypothesis are discussed  the simultaneous
observation of radio star scintillations on different radio frequencies
with increasing scintillation activity the amplitude and rate
have distributions which contain discontinuities
   /
857
apparent radio radiation at eleven m wavelength from venus  from
further observation and subsequent analysis it appears definite that
signals previously reported were not from venus but were interference
of terrestrial origin
   /
858
the freiburg radio spectrograph  the design of the solar spectrograph
described is based on that of wild and mccready
   /
859
the association of solar radio bursts with auroral stoaems  analysis
of two years observations of type two radio bursts shows a correlation
with auroral and magnetic storms with a mean time delay
   /
860
determination of the extinction in the earths atmosphere of radiation
discussion of the results of microwave absorption measurements on
solar radiation made at sunset and sunrise in berlin and on rugen
in the baltic
   /
861
the thermal radiation of the moon  a radiation temperature has been
measured showing no variation with the phase of the moon
   /
862
the radio emission from normal galaxies part one
   /
863
changes in the differential rigidity spectrum of primary cosmic rays
associated long term and short term intensity variations
   /
864
some properties of the van allen radiation  observations of the electron
bllt made with explorer four and explorer six are inconsistent with
the solar injection hypothesis the electrons released in the decay
of cosmic ray neutron albedo may represent a satisfactory source
for the outer zone
   /
865
measurement of radiation in the lower van allen belt  the maximum
of the belt occurred at fifteen n
   /
866
cosmic ray intensity in interplanetary space  cosmic ray intensity
has been calculated as a function of distance from the sun in the
region between the orbits of mars ane venus
   /
867
cosmic ray orbits in interplanetary magnetic fields  cosmic ray orbits
have been calculated in the interplanetary field suggested by alfven
the results are briefly discussed and compared with cosmic ray observations
   /
868
combined photographic and radio echo observations of meteors  measurements
have been made on a bright geminid meteor by means of a meniscus
schmidt camera and two pulsed radio transmitters operating at frequencies
near thirty six mcs  the radio echo duration is found to be several
orders of magnitude less than would be expected from simple diffusion
theory  this behaviour is explained in terms of the attachment of
electrons to neutral oxygen molecules to form negative ions and a
value for the attachment coefficient is determined
   /
869
the azimuth distribution of oblique reflections from meteor trails
and its relation to meteor radiant distributions  the measurements
refer to a north south path  the distribution of radiants which best
fits the observations is a heliocentric distribution uniform over
the celestial sphere
   /
870
the effect of attachment on radio echo observations of meteors  the
observed relation between visual meteor magnitude and echo duration
is explained by this mechanism as are the departures from the wavelength
squared variation of echo duration predicted by diffusion theory
attachment processes also account for the observation that the final
heights of enduring meteor echoes all centre about ninty five km
even though bright meteors may show a maximum in light intensity
below eighty km
   /
871
the character of the next sunspot maximum  from an application of
probability laws previously used it is concluded that the next sunspot
maximum may be weak  during the next eleven year cycle
   /
872
an estimate of the peak sunspot number  there is a probability that
the next smoothed peak sunspot number will be in the range
   /
873
on the origin of solar flares  the high concentration of energy stored
in the chromosphere can be accounted for by a particular class of
magnetic field whose lines of force have the general shape of twisted
loops protruding above the photosphere  when loops of opposite sense
and twist meet energy is dissipated in the form of a solar flare
   /
874
effects of the solar flares  an analysis of observations made at
kiruna sweden of ionospheric and geomagnetic disturbances following
flares
   /
875
lines of force of the germagnetic freld in space  the lines of force
from points in the northern hemisphere are traced to the southern
hemisphere using the first nine gauss coefficients with particular
reference to the auroral zones
   /
876
the ring current and the outer atmosphere  by hydromagnetic wave
propagation through the ionosphere  changes in the geomagnetic field
at ground level would be delayed less than one min after ring current
changes at several earth radii  the electric current associated with
particle motions in the van allen belts is examined
   /
877
correlated micropulsations at magnetic sudden commencements  using
wire loops fifty two square miles in area micropulsations were recorded
simultaneously in arizona and new jersey during the initial phase
of a magnetic storm  cross correlation between the two records shows
a time difference of two to three seconds which corresponds to that
for the sudden commencement
   /
878
diurnal and annual variations of the normalized amplitudes of sudden
commencements of magnetic storms at tamanrasset  an extension of
earlier work
   /
879
three dimensional consideration for current system of geomagnetic
variations part one current flow for polar elementary storm within
a spherical conducting shell
   /
880
effects of solar radiation pressure on earth satellite orbits  calculations
show that at a mean altitude radiation pressure can displace
the orbit echo balloon  for certain resonant conditions this effect
accumulates drastically affecting the satellites lifetime
   /
881
perturbations in perigee height of vanguard one  the effect of solar
radiation pressure on the perigee height of satellite is considered
the inclusion of this effect leads to closer agreement between observed
orbital data and theoretical results
   /
882
a doppler cancellation technique for determining the altitude dependence
of gravitational red shift in an earth satellite  description of
a technique by which the frequency of a moving source is corrected
for first order doppler shifts
   /
883
profile of upper atmosphere air density at the height derived from
the orbit of sputnik three
   /
884
satellite orbits and atmospheric densities at altitudes obtained
from the vanguard orbit determination program  the program is outlined
results of vanguard one measurements show that the minitrack and
computing systems can be operated with an overall accuracy within
one milliradian  atmospheric density results are discussed
   /
885
on an aspect of the relations between mechanics and artificial earth
satellites  it is suggested that satellites which orbit equatorially
may offer an opportunity to study fundamental laws of mechanics
   /
886
a report on the symposium on the use of space vehicles at the u
r  s  i  meeting  a discussion of possible experiments in the following
classes a  v  l  f  satellite measurements b  ion probes c  faraday
rotation measurements d  topside ionospheric sounders e  studies
of anomalous propagation
   /
887
ionizing radiation detected by pioneer two  the total ionizing component
of cosmic radiation was measured it shows a steady decrease near
this height
   /
888
altitude dependence and time variation of the radiation intensity
observed by u  s  satellite
   /
889
solar activity and deceleration of earth satellites  a correlation
between the irregularities of the orbital period of satellite and
solar radio emission during the period december january is discussed
   /
890
the satellite ionization phenomenon  evidence is given of ionization
effects due to the passage of satellites they are most noticeable
a day or so after large solar flares
   /
891
radiative cooling of satellite borne electronic components  the basic
principles of radiative cooling in a satellite are discussed it is
considered feasible that temperatures could be maintained provided
the proper skin coating is used
   /
892
ionospheric scintillations of satellite signals  results showing
variations from a smooth doppler shift curve for various frequencies
and orbits give a measure of frequency scintillation occurring and
hence the roughness of the intervening ionospheric path
   /
893
thermal and gravitational atmospheric oscillations ionospheric dynamo
effects included  the resonance theory of gravitational and thermal
oscillations in a rotating atmosphere is extended to include an electron
and positive ion gas with a permanent magnetic field superposed
expressions are obtained for the variation with height of the electric
field current density and ion drift velocitile  some comparisons
are made with observed ionospheric data
   /
894
atmospheric densities from satellites and rocket observation  current
data suggest revision of the a  r  d  c  model atmosphere to lower
densities  a revised model is presented
   /
895
artificial electron clouds part one  a summary report of the methods
techniques and operating procedures used in a series of eight rocket
experiments in which artificial electron clouds were produced in
the upper atmosphere
   /
896
artificial electron clouds part two  theoretical and practical considerations
in the creation of artificial clouds are presented  the altitude
limits for the generation of long lived dense clouds  part one above
   /
897
artificial electron clouds part three  a cloud was formed by the
release of atomic potassium from an aerobee rocket  an analysis of
results gave approximate values for wind velocity diffusion constant
thermal ionization efficiency and initial half width of the cloud
part two above
   /
898
the mesopause region of the ionosphere  a proposition by gregory
that the layer is formed by photo ionization of dust particles is
considered to be untenable
   /
899
strongly absorbing layers below fifty km  measurements at kiruna
sweden during the summer showed the height of the ionized layer causing
long duration absorption to be about fifty km  this supports the
hypothesis that the ionization is produced by protons  see below
   /
900
on some characteristics of the e layer  some aspects of the dependence
of e ionization on the geomagnetic field are discussed  an attempt
is made to deduce the mean world wide drift direction of e in summer
by using the time displacement that occurs for the daily maxima of
the hourly median values of e
   /
901
an attempt to measure the collision frequency of electrons in the
f region of the ionosphere  measurem  nts have been made of the change
in the f layer reflection coefficient with change in group path
results indicate that values of collision frequency obtained from
this type of measurement are unreliable but an upper limit is deduced
   /
902
abnormal features of the f region of the ionosphere at some southern
high latitude stations  the diurnal variation of f at port lockroy
shows a maximum near midnight and a minimum near noon during the
summer months  this abnormal variation is characteristic of the southern
west zone only and is not observed at other high latitude stations
in either the south or the north
   /
903
generalization of the appleton hartree magneto ionic formula  recent
laboratory results show that it is not valid to neglect the effect
of the electron velocity distribution function  an applicable generalized
expression for the complex refractive index is obtained
   /
904
the ion distribution above the f maximum  recombination is important
up to this height the ion distribution is controlled by diffusion
protons produced by charge exchange between hydrogen atoms and oxygen
ions move upward along the magnetic field lines with an equal number
of electrons and produce a medium for the propagation of whistlers
   /
905
on the interpretation of ionization in the lower ionosphere occurring
on both day and night side of the earth within a few hours after
some solar flares  the absorption effect following solar flares may
be interpreted as being caused by a high energy ion beam of very
small density emitted from the sun the ions moving in stormer orbits
   /
906
large scale irregularities in high altitude winds
   /
907
enhanced ionization in the polar ionosphere caused by solar corpuscular
emissions  enhanced ionization which follows several hours after
a large solar flare is considered to be caused by high energy protons
   /
908
polar blackouts associated with severe geomagnetic storms on sept
and feb
   /
909
on the shape of the auroral zones  model experiments on alfvens theory
of aurorae performed earlier have been extended to study auroral
zone eccentricity and include measurements of space charges and the
influence of the terrella potential  results show that the theory
is applicable to the model experiments
   /
910
geometry of the southern auroral zone and the evidence for the existence
of an inner zone
   /
911
studies of the upper atmosphere from invercargill new zealand part
one characteristics of auroral radar echoes at fifty five mc s  full
report of work briefly described earlier
   /
912
studies of the upper atmosphere from invercargill new zealand parts
two and three  analysis of data shows that a  the probability of
occurrence of radar echoes increases with an increase in local magnetic
k index b  a radar auroral zone exists whose size is related to the
k index c  echoes are observed in the daytime to less extent than
suggested by the diurnal variation of local k index d  there is no
direct relation between radar echo regions observed at fifty five
mc s and visual aurorae  part one above
   /
913
a four year summary of whistler activity at washington d  c  results
are analysed and presented in the form of curves of diurnal and month
to month variations of whistlers hiss and dawn chorus
   /
914
the relation between lightning discharges and whistlers  observations
made near uppsala show that whistler producing atmospherics contain
strong components around five kc s and often show multiple discharges
atmospherics not producing whistlers often show irregular constitution
and a gingle discharge but those giving rise to high field strengths
are always followed by whistlers
   /
915
low frequency electromagnetic radiation associated with magnetic
disturbances  continuous observation of naturally occurring radiation
in the band at sydney australia shows major bursts to be associated
with strong auroral and magnetic activity
   /
916
effect of temperature on photo voltaic solar energy conversion  theoretical
investigation of the behaviour of materials with band gaps varying
over a temperature range show that the best conversion performance
is obtained for the ideal junction current it is degraded by the
presence of recombination current  experimental data are given for
si gaas and cds cells and are compared with theoretical expectations
   /
917
investigation of selenium rectifiers under pulse conditions  to investigate
the voltage dependence of the resistance in the reverse direction
pulse measurements have been made of back resistance capacitance
barrier layer thickness and electric field intensity as functions
of the applied voltage
   /
918
stabilization of the magnetic field of an electromagnet  a system
is described for controlling both rapid and slow variations of the
magnetic field by means of a transistorized control stage and feedback
winding  slow variations are detected by the magnetic resonance of
protons in a ferric nitrate solution using a technique similar to
that described earlier
   /
919
precision thermostat  a temperature sensitive resistance bridge controls
a crystal oven to give a short period temperature stability
   /
920
a stable thermostat for the measurement of the noise and drift of
semiconductor circuit elements  the rectified output of a bridge
circuit containing a resistance thermometer is used to control the
heating of a stirred oil bath  the noise voltage of transistors in
a power supply circuit and of a zener reference diode have been measured
at very low and audio frequencies using the apparatus described
   /
921
an experimental impedance relay using the hall effect in a semiconductor
description of a definite impedance relay for the protection of
power transmission systems  the hall output voltage from an insb
crystal is balanced by a voltage from a rectifier unit when a fault
occurs in the system an out of balance voltage is produced which
operates an electromagnetic relay
   /
922
analogue division circuit  the circuit contains only magnetic cores
and windings and is suitable for use under severe environmental conditions
a detailed analysis is given
   /
923
all transistos magnetic core memories  the properties of special
small ferrite cores developed for use in high speed transistor drive
storage systems are discussed
   /
924
high speed track selection for a magnetic drum store  a survey of
mechanical and electronic relay switching systems is given and the
advantages of transistor switches are discussed
   /
925
high inductance simulation  describes a circuit which eliminates
the resistance component in a pentode reactance valve giving a simulated
inductance of infinite
   /
926
the application of printed wiring to development and small batch
production with particular reference to television equipment
   /
927
an equivalent circuit for transformers in which nonlinear effects
are present  inductive parameters of a transformer are better represented
by the two type than by the t type equivalent circuit
   /
928
analysis of series connected saturable reactor with capacitive loading
and finite control resistance by use of difference equations  observation
of transients in the series connected saturable reactor with high
impedance control source  details are given of apparatus for observing
the effects of transients introduced into a reactor operating in
the proportional mode
   /
929
the diffusion of moisture in electrical capacitors and their insulation
resistance  the laws of moisture diffusion are derived mathematically
and investigated experimentally on paper capacitors  the effect of
moisture on the insulation resistance of the dielectric is calculated
and comparison is made with measurements on plastic covered capacitors
stored under conditions of high humidity
   /
930
the optimum formula for the gain of a flow graph or a simple derivation
of coates formula  an independent derivation of coates formula based
on determinants is given  the difference between masons and coates
flow graphs is discussed and it is shown how one is obtained from
the other
   /
931
the use of iterated laplace transformations in the solution of combined
circuit field problems
   /
932
the characteristics of different types of coupling of two coupled
undamped electrical oscillating systems without an impressed voltage
the effect of various types of coupling on the parameters of oscillatory
circuits are considered
   /
933
statistical spectral output of powerlaw nonlinearity  methods are
given for calculating the output power and the error power for nonlinearities
which can be described by power series for gaussian and for
certain other special kinds of input signals
   /
934
spectral output of piecewise linear nonlinearity  the transference
or effective gain of a piecewise linear component is derived
   /
935
topological evaluation of network functions  the results are given
of an investigation of various combinations of linear passive quadripoles
by means of topological identities
   /
936
the analogy between the weissfloch transformer and the ideal attenuator
reflection coefficient transformer and an extension to include the
general lossy two port
   /
937
matching and bandwidths  formulae and curves are given for the bandwidth
of different arrangements for input and output matching of single
stage and band pass filters
   /
938
the structure of the iterative matrix of reactance quadripoles with
a given derived circuit or a given characteristic function  the relations
between the structure of the characteristic function the irerative
matrix and the derived circuit or canonical ladder network are established
and the results are tabulated
   /
939
nomenclature of band filters and of band filter design  the principal
design formulae and symbols and definitions of filter characteristics
are summarized in tabular form
   /
940
solution to the realizability problem for irredundant boolean branch
networks  this type of network is defined for the two terminal and
the n terminal case and a general solution is given for the existence
and realizability problem
   /
941
basic concepts of the multidimensional space filters  the establishment
of the basic tensors of a space filter is illustrated by means of
a tetrahedron
   /
942
single control element wien bridge  the theory of operation of two
modified forms of the wien bridge is described  the network may be
controlled by a single variable l c or r and has applications as
a frequency bridge oscillator or selective amplifier
   /
943
a wide band phase shifter  a method is described for obtaining a
phase shift over a bandwidth determined by the characteristics of
the filter used
   /
944
low noise tunnel diode down converter having conversion gain  the
nonlinearity of the negative resistance characteristic of the tunnel
diode can be used for frequency conversion
   /
945
simple amplitude stabilized twin t audio oscillator  the stabilization
is achieved by a clipping feedback loop
   /
946
electromechanical low frequency oscillator  the sinusoidal linear
movement of a slider is converted to a sinusoidal angular motion
of a rotary potentiometer contact arm to provide electrical oscillations
   /
947
frequency control of an oscillator by nuclear magnetic resonance
a description of a simple superregenerative oscillator that produces
a coherent signal at the magnetic resonance frequency of a sample
in its coil
   /
948
design problems of multivibrators  design calculations for free
running and for cathode coupled and anode coupled monostable multivibrator
circuits are discussed
   /
949
blocking oscillator circuit for very short pulses of high repetition
frequency  the design of a double triode circuit is given which is
capable of generating pulses
   /
950
some recent improvements in low power pulse generators  three miniature
thyratron circuits used as submodulators for radar transmitters are
described  high stability free running and triggered versions are
discussed with methods of overcoming duty ratio limitations of the
valves used
   /
951
theory of a fast switching electron beam frequency coherence and bandwidth
of a gas discharge harmonic generator  long time delays from a single
magnetic storage core  time delays up to several minutes can be accurately
achieved using an assymetrical bidirectional core voltage  the
delay may be controlled by a d  c  voltage or current change or by
a change of resistance
   /
952
analysis and design of a transistor linear delay circuit  an analysis
of the emitter coupled linear delay circuit is given  maximum to minimum
output pulse width ratios of several hundred have been obtained
   /
953
the anode cathode follower  a two stage circuit of near unity gain
which inverts negative pulsesis described
   /
954
analysis of magnetic amplifiers without diodes  a general method
of magnetic amplifier analysis is developed
   /
955
analysis of magnetic amplifier with diodes  an analysis restricted
to amplifiers terminated in a resistive load and to voltage waveforms
typical of such amplifiers
   /
956
graphical evaluation of magnetic amplifier performance based on constant
voltage reset test  core characteristics for various reset fluxes
are determined experimentally leading to a graphical evaluation of
the performance of a two core self saturating magnetic amplifier
   /
957
capacitively coupled magnetic amplifiers  the amplifier described
operates at a high carrier frequency with capacitive coupling of
the signal to the load  this technique realizes the advantages of
true a  c  amplification  an experimental three stage amplifier is
described
   /
958
the winding capacitances in magnetic amplifiers  the distributed
winding capacitance can be replaced by a lumped capacitance for which
an empirical formula is found
   /
959
calculations and measurements for the optimum design of low noise
transistor amplifiers  the conditions for making the transistor noise
factor a minimum are calculated for white noise  equations are given
for the most favourable combination of source impedance and emitter
current  measurements were made of these optimum values as a function
of various transistor parameters and of temperatures
   /
960
transistor amplifier has hundred megacycle bandwidth
   /
961
analysis of the split load stage transistorized  expressions are
derived for the current and voltage gain output impedance and output
return loss of a single stage negative feedback circuit  results
are incorporated in an analysis of a three stage feedback amplifier
with split load output
   /
962
contribution on the stabilization of the operating point of transistors
direct current positive and negative feedback over two or more stages
in earthed emitter transistor amplifiers provides effective stabilization
against temperature variations and differences in transistor characteristics
   /
963
the optimum line width for the transition used in a reflection cavity
maser amplifier  the line of the amplifying transition in a reflection
cavity maser is shown to have an optimum value which will give maximum
amplification bandwidth at a fixed gain  difficulties associated
with achieving the optimum line width in practice for the paramagnetic
maser are briefly discussed
   /
964
relaxation time and multiple pumping effects in masers  optimization
of relaxation times combined with multiple pumping cannot by itself
extend the operation of masers past the liquid nitrogen range without
degrading the performance below that now attainable at liquid helium
temperatures with three level masers
   /
965
packaged tunable l band maser system  a maser tunable with a voltage
gain bandwidth product is combined with an l band circulator and
auxiliary equipment into an operational unit
   /
966
spontaneous emission from an inverted spin system  a summary of results
of calculations made in an attempt to explain the origin of the observed
modulation effects in two level masers
   /
967
c  w  millimetre wave maser  characteristics are summarized and some
useful properties of the paramagnetic material are described  results
indicate that the material will be useful far beyond the frequency
range investigated
   /
968
some notes on the history of parametric transducers
   /
969
a ferromagnetic amplifier using longitudinal pumping  describes early
experimental results indicating a gain with an x band pump power
   /
970
parametric phase distortionless l band limiter  the diode loaded
helix as a microwave amplifier  application of the sampling function
to circuit analysis of modulators and demodulators using diodes
takes into account the forward and reverse resistance of the diodes
   /
971
a broad band cyclotron resonance r  f  detector tube  operation is
based on the cyclotron resonance of an electron beam in a static
magnetic and r  f  electric field  in the pencil beam tube described
spiralling electrons are detected by a honeycomb mesh grid the current
intercepted by the grid is greatest at resonance and is proportional
to the r  f  signal power  mechanical details and operating conditions
are given  a simplified energy transfer analysis enables the electrical
characteristics to be predicted
   /
972
universal units of magnetism mechanics and temperature
   /
973
some new aspects of colour perception  computed theoretical figures
based on mathematical analysis are shown to be in good agreement
with empirical results of land  an explanation is given in terms
of classical colour perception theories in conjunction with the experimental
psychological phenomenon of colour transformation
   /
974
efficiency of field ionization at a metal surface  theoretical analysis
of the dependence of the field ion current on various parameters
   /
975
variational principle for transport phenomena  the variational principle
for interband scattering is derived and generalized by the introduction
of an external magnetic field and lattice vibrations
   /
976
quasi particles and gauge invariance in the theory of superconductivity
theory of electrical conduction in high magnetic fields  the role
of space charge in gas break through between equal parallel plane
electrodes below the paschen p d minimum  the paschen characteristic
for discharges is discussed in detail and some explanations are found
with the help of the field emisson theory
   /
977
sim litude and anode material effects in h and d discharges below
the critical pressure  the breakdown potentials of h and d gases
were determined below the critical pressure in two similarly shaped
discharge valves of different size  with stainless steel anodes and
cathodes both gases obeyed paschens law  when the anodes were made
of pb or al some deviations were observed possibly resulting from
deposition of anode material on the cathode
   /
978
microwave noise from low pressure arcs  experimental data indicate
that the ignition of an arc discharge is accompanied by considerable
microwave noise
   /
979
solutions of the equations of space charge flow for radial flow between
concentric spherical electrodes  the solutions are formulated so
that arbitrary initial conditions may be introduced  by this means
a variety of physical problems can be solved with the aid of a table
of airy functions
   /
980
some solutions to the equations of steady space charge flow in magnetic
fields  earlier analysis is extended to include the case of magnetic
field components perpendicular to the cathode  sets of solutions
are given for the flow from conical and cylindrical cathodes for
a broad class of magnetic field configurations
   /
981
the possibility of electron total energy distribution analysis in
a quasi spherical capacitor  the energy distribution of electrons
emitted at various angles from a plane disk shaped target at the
centre of a spherical collector is determined from an analysis of
electron trajectories  the discrepancy between these and those for
a spherical capacitor does not exceed one per cent  the provision
of an aperture in the collector for an electron gun results in a
five per cent error
   /
982
the formulation of electron diffraction by means of a scattering matrix
and its practical applicability  electron diffraction by a crystal
plate is treated by dynamic diffraction theory
   /
983
apparatus for direct observation of low energy electron diffraction
patterns  the equipment designed for high vacuum gives the diffraction
pattern on a fluorescent screen
   /
984
on the magnetic perturbation of an electron beam
   /
985
a new method for measuring the attachment of slow electrons in gases
simultaneous measurements of attachment coefficient and the ratio
of drift velocity to diffusion coefficient are reported
   /
986
measurement of plasma temperature and electron density  the value
of electron density deduced earlier is twice the true value
   /
987
microwave investigation of plasma in shock tube  experimental details
and results obtained
   /
988
on the diffraction of electromagnetic pulses by curved conducting
surfaces  starting with the known steady state solutions for diffraction
by a perfectly conducting convex surface the corresponding transient
responses are derived using fourier laplace inversion  explicit results
are given for an incident wave which varies with time as a step function
   /
989
total electromagnetic cross sections of imperfectly conducting cylinders
experimental and theoretical results are discussed for the case
of scattering from cylinders with length comparable to and with diameter
small compared with the wavelength of illumination
   /
990
use of chebychev polynomials in thin film computations  from herpins
expression for the mth power o a multilayer matrix very simple closed
formulas are derived for the matrices and optical constants of any
multilayer with a periodic structure
   /
991
high resolution n  m  r  spectrometer with the radio frequency controlled
by the magnetic field
   /
992
prec sion zeeman modulation microwave spectrometer  a spectrometer
is described for measuring the rotational fine structure of oxygen
   /
993
anomalies in the absorption of radio waves by atmospheric gases
reasonable agreement is shown between the losses predicted by van
vleck and recent measurements for oxygen but for water vapour the
measured loss is greater  reasons for the discrepancy are discussed
   /
994
remarks on the mass energy and momentum of photons electrons and
other elementary particles  relations between the corpuscular velocity
of a particle and the phase velocity of the corresponding wave are
considered and the theoretical equivalence of particle and wave are
discussed with reference to a possible experimental verification
of the particle concept
   /
995
a note on the polar absorption event of may  galactic noise measurements
at five stations showed an increase rn absorption lasting up to thirty
six h  possible solar control mechanisms are discussed
   /
996
extraordinary noise disturbance following a mogel dellinger effect
during the large solar eruption of march an initial decrease of cosmic
noise intensity observed was followed by a high intensity noise burst
lasting several hours
   /
997
a relation between solar radio emission and polar cap absorption
of cosmic noise  a statistical study has been made of the relation
it appears that the polar cap absorption events are closely associated
with the occurrence of wide band cm wave outbursts of type four events
and their duration is related to the presence on the sun of active
regions of noise storms
   /
998
radio astronomical measurements of the sun with particular regard
to the phenomena during chromospheric eruptions  survey of the measurements
of solar r  f  emission in relation to various types of solar
disturbance
   /
999
a shell source of radio emission  report of observations made with
the mc s interferometer at the mullard radio astronomy observatory
cambridge
   /
1000
the eta carinae nebula and centaurus a near mc s part one
   /
1001
a twenty one cm survey of the southern milky way
   /
1002
elementary particles in cosmic radiation  review of present state
of knowledge and measurement techniques
   /
1003
cosmic radiation intensity decreases observed at the earth and in
the nearby planetary medium  measurements made simultaneously at
earth radii at balloon altitudes and on the earths surface at the
time of a large forbush decrease show the same magnitude of decrease
of primary cosmic radiation  these results do not therefore agree
with hypotheses which invoke the presence of the earth and the geomagnetic
field to account for the forbush decrease
   /
1004
maximum total energy of the van allen radiation belt  the results
of the spherical harmonic analysis of the geomagnetic field show
an upper limit for the ener  y that can be stored in the van allen
radiation belt
   /
1005
distribution of trapped radiation in the geomagnetic field  an examination
of the altitude dependence of trapped radiation from explorer
one measurements shows that the radiation intensity data in the vicinity
of the magnetic equator can be well represented by the scalar intensity
b of the real geomagnetic field  the value of b at the lower boundary
of the inner zone increases with magnetic dip latitude
   /
1006
magnetic storms and the van allen radiation belts observations from
satellite explorer fourth  a marked decrease in intensity of particles
in the outer belt was observed during magnetic storms  it is suggested
that this is due to atmospheric heating and expansion at fairly high
latitudes  the absence of intensity changes in the inner belt is
consistent with a cosmic ray albedo neutron origin of inner zone
protons
   /
1007
radio frequency scattering from the surface of the moon  sensitive
radars show the presence at mc s of a scattered component in addition
to the quasi specular high light from the moon centre
   /
1008
measurements of lunar reflectivity using the millstone radar  highly
stable coherent pulse measurements made at mc s enable range doppler
frequency contours to be plotted for the rotating moon  a precision
of two parts in ten for the observed doppler frequency has been obtained
a number of measurements are described substantial echoes are
observed out to the lunar limbs
   /
1009
lunar echoes received on spaced receivers  results obtained imply
that a minimum diversity distance of about one km on the earths surface
is adequate to achieve diversity reception for communications via
the moon
   /
1010
radar echoes from the sun  details are given of tests made in april
transmitter operating with an aerial system consisting of four rhombics
in broadside array covering a rectangular area  data were analysed
by computer cross correlation curves are reproduced and discussed
   /
1011
solar limb surges accompanied by x ray emission  simultaneous observations
of hx radiation and recordings of atmospherics at twenty seven
kc  s indicate a pronounced coincidence in time of sudden enhancements
of atmospherics with surge appearances  the sudden enhancements could
be interpreted as x radiation emitted by an adjacent region of the
solar corona
   /
1012
correlation in geophysics  the advantages of using a correlation
number based on a counting process are discussed in comparison with
the limitations inherent in the use of a correlation coefficient
examples are given of the correlation of ionospheric data
   /
1013
earths main magnetic field to one hundred and fifty two kilometres
above fort churchill  a report on rocket flight measurements under
magnetically quiet conditions in the daytime
   /
1014
rockets and satellites in the service of geophysics  a review of
measurements made by artificial satellites with an outline of future
plans
   /
1015
space science  a report of the international space science symposium
held in nice reviewing in particular the results of earth satellite
and lunar probe measurements
   /
1016
magnetic damping of rotation of the vanguard one satellite  comment
on an error in calculations given of may and authors reply
   /
1017
density of the upper atmosphere and its dependence on the sun as
revealed by satellite orbits  an extension of earlier work
   /
1018
triangulation a precise method for satellite tracking  the theory
of triangulation is described and applied to a photographic system
   /
1019
determination of corrections to mark two minitrack station coordinates
from artificial satellite observations  corrections may be deduced
from a comparison of radio observations with the predicted orbit
   /
1020
radio observations during the decay period of the soviet satellite
delta two  measurements made at jreisach west germany on sputnik
three during the period march april show irregularities in the period
of revolution
   /
1021
faraday effect in the transmissions from fast spinning satellites
a note on signal strength variations for the case of a satellite
rotation period small compared to the faraday fading period
   /
1022
scintillations of the twenty mc s signal from the earth satellite
information on the structure and movements of ionospheric irregularities
has been obtained by studying fading patterns on spaced receivers
   /
1023
electron density measurements in the upper ionosphere using the faraday
rotation of radio signals from artificial satellites  agreement between
observations and the calculated faraday rotation curve is improved
when account is taken of horizontal variations of the ionosphere
estimated from hourly ionograms
   /
1024
the vector field proton magnetometer for i  g  y  satellite ground
stations  vector magnetic field measurements of high accuracy can
be obtained by applying homogeneous bias fields to a proton precessional
magnetometer
   /
1025
radiation damage and transistor life in satellites
   /
1026
artificial electron clouds part four  report of radio radar and optical
observations of an electron cloud created by the night time release
of caesium at km from a nikecajun rocket  an analysis of experimental
data indicates that the electrons observed can reasonably be ascribed
to thermal ionization
   /
1027
a theory of electrostatic fields in the ionosphere at nonpolar geomagnetic
latitudes  es coupling between the dynamo and f regions and between
magnetically conjugate parts of the regions themselves the electric
source field produced by winds in the dynamo region and the possibility
of significant electron density variations in the f region due to
es fields are examined
   /
1028
development of the maximum electron density of the e layer at leopoldville
binza  e layer data obtained during the period february december
are analysed  the diurnal variation of maximum electron density conforms
closely to chapmans law
   /
1029
sporadic e as observed by back scatter techniques in united kingdom
using a rotating aerial back scatter sounder during the i  g  y
diurnal seasonal and geographical e characteristics have been obtained
on particular occasions the movement of e clouds has been tracked
and their size and ionization determined
   /
1030
peculiarities of the ionosphere in the far east a report on i  g
y  observations of sporadic e and f region scatter  oblique incidence
observations at fifty mcs show that for any given transmission loss
sporadic e is three to five times more prevalent in the far east
than in the caribbean
   /
1031
height and thickness parameters for region f of the ionosphere  more
useful parameters may be obtained by replacing measurements of hm
by measurements of heights at fixed submultiples of the maximum density
   /
1032
theoretical world curves of maximum ion density in a quiet f region
the curves plotted in terms of latitude and local time for solstice
and equinox conditions are generally the same as those obtained from
ionosonde date  the analysis shows that diffusion plays a significant
part in controlling f ionization
   /
1033
asymmetry between the f region of the ionosphere in the northern
and southern hemispheres  an explanation is sought of the asymmetry
in the seasonal variations of the critical frequency of the f layer
at high latitude stations in the northern and southern hemispheres
during years of minimum sunspot number  an extensive survey suggests
that horizontal wind systems in the f region may be the cause
   /
1034
spread f in baguio through half a solar cycle  a statistical survey
over six years shows that the occurrence of spread f is associated
with periods of downward movement of ionization  the seasonal and
diurnal variation of occurrence is also markedly different between
periods of high and low solar activity
   /
1035
critical remarks on the description of the ionization in the ionospheric
e layer  changes from nominal value in the exponent of the cos law
of e layer ionization are discussed these are necessitated by the
difference between seasonal and daily variation of e layer noon values
harnischmachers empirical formult for this exponent is not confirmed
by an analysis of data  the derivation of a world wide e layer character
figure from data obtained at one locality is considered impossible
in view of geographic differences in ionization characteristics
   /
1036
some abnormalities in the variations of f layer critical frequency
during the period of high solar activity of solar cycle  the values
of taipet become independent of sunspot numbers at high solar activity
this saturation effect is related to other abnormalities in the variations
at this station
   /
1037
the ionosphere and solar activity  the correlation between monthly
median critical frequencies and solar activity was determined for
washington d  c  results were compared with those from a similar
study made for six arctic stations  for noon data a greater value
at zero sunspot number and a slightly greater slope were obtained
for washington than for the arctic locations  the influence of increased
solar activity on the behaviour of the midnight ionosphere is discussed
   /
1038
the valley effect in the interpretation of ionospheric eclipse records
the spurious maxima in electron density curves at fixed heights can
be explained by the presence of a valley between the f and f layers
effect of annular solar eclipse of april at sunrise on the f layer
of the ionosphere  results are given of observations made at three
stations in south india  a marked decrease in ionization density
with the progress of the eclipse was observed
   /
1039
a theory of the origin and geomagnetic control of two types of high
latitude e  the auroral belt type of e may be caused by electrons
from a region of trapped particles indicated by the extent of a night
time peak in f type es  thule type es may be caused by an influx
of electrons approaching from the direction of the sun at geomagnetic
noon
   /
1040
outline of a theory of magnetic separation of auroral particles and
the origin of the sd field  diurnal variations of sporadic e ionization
at macquarie island are identified with magnetic separation of incoming
protons and electrons  associated visual aurorae are discussed
   /
1041
geomagnetic and current control of e region absorption
   /
1042
magnetic storm effects on the f region of the ionosphere  a preliminary
report on the results of a true height analysis carried out for washington
d  c  during three severe sc type magnetic storms
   /
1043
ionospheric thermal radiation at radio frequencies in the auroral
zone  the temperature of the lower ionosphere is estimated for observations
of radio noise at two mc s  temperature range and seasonal variation
of temperature are the same as for temperate latitudes
   /
1044
an unusual ionospheric disturbance in the antarctic on june to july
unusually high values were obtained for twelve hours at two ionospheric
observatories during a magnetic storm
   /
1045
auroral research at the hillhead experimental station  general information
is given about the paraboloid installed at hillhead scotland
to study the effects of aurora on the propagation of radio waves
   /
1046
a theory of trapping of whistlers in field aligned columns of enhanced
ionization  using ray theory it is shown that the condition for whistler
propagation in ducts depends on the ratio of the electron density
in the column to that of the background  the theory explains part
of the variation of whistler rate with latitude
   /
1047
directional observations of five kc s radiation from the earths outer
atmosphere  an account is given of the estimation of the position
and size of sources of l  f  noise bursts associated with geomagnetic
disturbances
   /
1048
h  f  noise radiators in ground flashes of tropical lightning  a
detailed analysis of h  f  noise sources in tropical ground flashes
v  l  f  phase characteristics deduced from atmospheric waveforms
   /
1049
a z transform describing function for on off type sampled data systems
the derivation of the function for a sinusoidal error signal is fully
described
   /
1050
a note on the steady state response of linear time invariant systems
to general periodic input
   /
1051
a class of optimum control systems  a class of optimum control systems
is defined and investigated with special emphasis on time domain
concepts  this class is particularly suitable for feed back control
applications where adaptability to changing conditions is desired
   /
1052
linear circuits regulate solid state inverter
   /
1053
a more stable three phase transistor core power inverter  a square
wave inverter for driving gyroscope motors is described which could
provide up to one kw continuous power
   /
1054
a circuit for the protection of a stabilized transistor power supply
details are given of a transistorized protection circuit providing
switch off times and activated by currents below the full load value
   /
1055
small universal computing machine with magnetic ferrite elements
lem one  description of the development and operation of a digital
computer using contactless ferrite core storage and logic elements
and a capacitive permanent store
   /
1056
chemically deposited nico layers as high speed storage elements
   /
1057
direct metering for a transformer analogue computer  descriptions
are given of the phase shift and combining networks of the witton
network analyser wina
   /
1058
procedure for designing reciprocal computer circuits  circuits with
outputs approximately inversely proportional to their inputs can
be constructed with diodes resistors and d  c  supplies
   /
1059
semiconductor networks for microelectronics  both active and passive
components are fabricated in a single crystal semiconductor wafer
the development from a circuit diagram by combining vxide masking
diffusion metal deposition alloying and surface shaping is described
   /
1060
inductive elements for solid state circuits  a resonant circuit is
described in which a ge diffused base transistor with an open circuit
base connection functions as a negative resistance diode with an
effective inductance of fifteen uh  the low frequency noise generated
by the diode is attributed to avalanche multiplication occurring
in localized non stationary areas
   /
1061
clear method for the determination of transformer equivalent circuit
diagrams  the electrical equivalent circuits are derived directly
from the magnetic equivalent circuit using principles of circuit
duality
   /
1062
the variation of cryotron current amplification factor with temperature
the factor increases as the penetration depth decreases and there
is probably a lower limit to the film thickness which can be used
   /
1063
monitoring multiple inputs simultaneously  description of an electronic
switch and sensing circuit which may be used for detecting a signal
or absence of signal on one of many channels
   /
1064
u  h  f  resonator with linear tuning
   /
1065
a different approach to the approximation problem  an approximation
method for the synthesis of network curves
   /
1066
a constant resistance network
   /
1067
general properties of the propagation constant of a nonreciprocal
iterated circuit  formulae are given and the use of such circuits
in travelling wave valves is considered
   /
1068
method for simplifying filter design  using cauer parameters zobel
filters may be simply designed with a minimum number of elements
   /
1069
narrow band filtering of random signals  shows that the output of
a narrow band filter is not necessarily more gaussian than the input
   /
1070
selecting rc values for active filters  the circuit configuration
described facilitates the design of filters with zero transmission
at either infinite or zero frequency  component values are determined
from the symmetry of the network voltage transfer function by the
technique of coefficient matching
   /
1071
theory of a frequency synthesizing network  by the introduction of
sideband algebra and a frequency symbolic network a formal method
of designing frequency combining and selecting circuits is developed
   /
1072
general n port synthesis with negative resistors
   /
1073
noise spectrum of phase locked oscillators
   /
1074
voltage tuning in tunnel diode oscillators
   /
1075
high frequency negative resistance circuit principles for esaki diode
applications
   /
1076
phase shift oscillator  an analysis based on the describing function
method for nonlinear control systems which takes account of the nonlinear
limiting process and allows the oscillator to be designed to give
specific values of harmonic distortion
   /
1077
a voltage modulated variable pulse rate generator  a pulse generator
is described the output frequency of which is a linear function of
the input voltage  the circuit is a screen coupled double phantastron
pulse circulating system with suitable modifications to improve the
accuracy of transfer at low output frequencies  achieving stable
discriminator levels with a biased input diode
   /
1078
counting and timing circuits use saturable reactors  method of frequency
division using a controlled rectifier and saturable reactor are described
   /
1079
the application of phase locking techniques to the design of apparatus
for measuring complex transfer functions  the principles of phase
lock synchronization are described and details of two instruments
for measuring complex voltage ratios
   /
1080
nonlinear distortion including cross modulation in high frequency
transistor stages  harmonic distortion and cross modulation are calculated
for the earthed base transistor treated as a nonlinear quadripole
and assuming low current densities  the solutions obtained are applied
to the earthed emitter configuration and experimental results of
tests on earthed emitter circuits confirm the theory even for relatively
high collector currents  an interpretation is given of a pronounced
minimum in cross modulation depth as a function of collector current
   /
1081
negative l and c in solid state masers  gives an equivalent circuit
for a maser which includes negative l and c components
   /
1082
effect of nuclear polarization on the behaviour of solid state masers
an account is given of experiments conducted on a ruby sample placed
in a doubly resonant microwave cavity  with bloembergen stimulation
the application of r  f  power to a coil round the sample produced
an increase in amplifier gain the effect being greatest at the resonance
frequency of the free ai nuclei
   /
1083
proposed molecular amplifier and coherent generator for millimetre
and submillimetre waves  the difficulties of obtaining maser action
increase with frequency owing to the increasing number of energy
sublevels and to decreasing sensitivity of molecules to field gradients
a proposed method of avoiding these difficulties is to use special
types of stimulated emitter and to separate molecules with different
energy levels by a combination of inhomogeneous and homogeneous fields
respectively outside and inside the cell
   /
1084
can the landau levels of free carriers be utilized for a submillimetre
wave semiconductor maser  of using cyclotron resonance in semiconductors
for obtaining maser action is discussed  the difficulty of having
signal and pumping frequencies of the same order can be overcome
with the aid of the oscillatory magneto absorption effect
   /
1085
theory of a negative resistance transmission line amplifier with
distributed noise generators  a transmission line with distributed
positive and negative resistances as well as with distributed noise
factor are derived as a function of boundary conditions matching
conditions and distributed noise  it is found that low noise amplification
can be achieved on such a line provided the lien is characterized
by high gain per unit length high total gain good matching and low
distributed noise  a distortionless active line for such low noise
amplifiers appears attractive
   /
1086
comparison of gain bandwidth and noise figure of variable reactance
amplifiers and converters  it is shown theoretically and experimentally
that the converter has a greater bandwidth than the amplifier for
the same gain and noise figure
   /
1087
theoretical limitations to ferromagnetic parametric amplifier performance
   /
1088
microwave parametric amplifier using silver bonded diode
   /
1089
operation of an esaki diode microwave amplifier
   /
1090
a technique for cascading tunnel diode amplifiers  the simple tunnel
diode amplifier does not lend itself readily to cascading but the
addition of a second tunnel diode to each stage gives an amplifier
which can easily be cascaded
   /
1091
an extension of the mode theory to periodically distributed parametric
amplifiers with losses
   /
1092
rectifier modulators with frequency selective terminations  the effects
of even order modulation products are examined and the conditions
for the elimination of such products determined  the theory is confirmed
by experimental results
   /
1093
the input impedance of rectifier modulators  the impedance is calculated
for a number of cases of shunt series and ring type modulators
   /
1094
a pulse width modulator  modulation is achieved using the hole storage
effect in a junction transistor
   /
1095
on the additivity of photocurrent and secondary electron current
measurements on ai provide confirmation of the existence of additivity
as asserted by ekertova and contrary to the findings of dember which
may have been affected by an internal photoeffect in the oxide layer
of the target
   /
1096
nonlocal current field relationship in metals  chambers analysis
of the response of the conduction electrons in a metal to an internal
electric field is extended to cover the case of longitudinal fields
   /
1097
the theory of elementary excitations in atomic semiconductors  the
simplest model of an atomic semiconductor is considered in which
every atom has a saturated valence shell with two electrons  electrons
holes ortho and para exitons are considered as elementary excitations
and the hamiltonian describing the system is derived taking account
of interaction between them
   /
1098
charge localization on the surface of oxide coated cathodes  anomalous
results obtained while using the kelvin method of determining contact
potential differences are investigated  very high contact potential
differences which occur only after the passage of a discharge are
attributed to both positive ions and electrons which remain on the
oxide surface for long periods depending on the conductivity of the
oxide
   /
1099
plasma stability and boundary conditions
   /
1100
an approximate solution of a problem concerning the motion of a conducting
plasma  a new method for the asymptotic integration of linear
differential equations with partial derivatives of the hyperbolic
type has been applied to the integration of equations of plasma oscillations
   /
1101
theory of electron oscillations in nonuniform plasmas  deals with
the case of an externally injected electron beam in a plasma
   /
1102
excitation of plasma oscillations  the apparent paradox between the
theory of bohm and gross and the experiments of looney and brown
on the excitation of plasma oscillations by the two stream mechanism
is resolved
   /
1103
experimental two beam excitation of electron oscillations in a plasma
without sheaths  coherent standing waves of longitudinal electron
oscillations have been excited in a plasma bx two independent oppositely
directed electron beams whose axes coincided  there were no sheaths
on the electrodes from which the electron stream entered the plasma
results of single beam experiments looney and brown using either
equal or unequal sheaths are verified
   /
1104
influence of negative ions on ambipolar diffusion of electrons  a
note on microwave measurements of the afterglow properties of plasmas
in ne ar mixtures
   /
1105
propagation of acoustic and electromagnetic waves in a half space
a half space is considered in which the impedance at the boundary
is given in the form of an arbitrary complex number and a general
solution of the wave equation is formulated by introducing a function
which reverts to zero at the boundary  expressions for the acoustic
and e  m  potential are derived in terms of this function
   /
1106
the diffraction at apertures in nonplanar screens  the approximation
method given is applied to the case of a circular aperture in a funnel
shaped screen for a scalar plane wave and for an e  m  plane wave
propagating in the axial direction
   /
1107
diffraction of electromagnetic waves according to braunbeks approximation
braunbeks approximation method is applied to problems of e  m
wave diffraction in particular to that of a linearly polarized plane
wave normally incident on a circular aperture in a perfectly conducting
plane screen and on a perfectly conducting plane circular disk  the
near field distribution is calculated and compared with results of
the rigorous method of solution and of kirchhoffs approximation
other approximation methods are discussed
   /
1108
diffraction by a unidirectionally conducting half plane  a solution
is obtained by transform methods for diffraction of a plane e  m
wave
   /
1109
second approximation in the method of small perturbations  the propagation
of a plane wave in a medium containing random inhomogeneities
is considered  a second approximation in the perturbation method
is obtained assuming that the correlation coefficient of refractive
index fluctuations is gaussian  this is applied to determine the
form of the normalizing factor in the wave equation
   /
1110
the scattering of a olane wave by a row of small cylinders
   /
1111
variational method for the propagation of electromagnetic waves in
a plasma  using a variationalprinciml a first approximation is obtained
for the propagation constant of the te mode in a rectangular waveguide
containing a thin layer of gyroelectric plasma
   /
1112
action of a progressive disturbance on a guided electromagnetic wave
a method of approximations is applied to the investigation of the
modes of action of a medium on a guided e  m  wave  the results are
discussed in relation to parametric amplification
   /
1113
the relation between the polarization and the magnetic field intensity
in the exiton absorption region  extension of pekars electromagnetic
wave theory to molecular crystals with a weak interaction between
the exciton and the lattice vibrations
   /
1114
giant spin density waves  an analytical treatment of energy states
in an electron gas in which the lowest energy state is proved not
to be the hertree fock ground state but to have a spiral antiferromagnetic
structure  implications of this are discussed
   /
1115
interplanetary space and the earths outermost atmosphere
   /
1116
radar astronomy symposium report  the subjects were radar studies
of the moon the planets the sun meteors and aurorae and the exosphere
and interplanetary medium
   /
1117
radio astronomical measurements from earth satellites  ionospheric
and atmospheric absorption limit measurements made on earth  a summary
is given of some of the problems whose solution can best be sought
by measurements with apparatus mounted in earth satellites
   /
1118
polarization and angular extent of radiation from jupiter  it is
found that the source is strongly linearly polarized especially in
the outer regions which extend to about three times the diameter
of the planet
   /
1119
on the polarization of sources of solar activity on three cm wavelength
about sixty per cent of the bursts observed were polarized the probability
of observing a polarized burst being greater when the source
had a small diameter  great bursts associated with metre wave bursts
of type four have been found in most cases to be polarized
   /
1120
solar radio bursts and cosmic rays  the correlations between the
various types of bursts are discussed
   /
1121
periodicities in solar radio noise emission  attention is drawn to
the presence of sweeper trains gerson and gossard in the work of
roberts
   /
1122
on the theory of protons trapped in the earths magnetic field
   /
1123
the unusual cosmic ray events of july  intensity variations recorded
at six stations are discuss the cosmic ray increase of july  variations
in the intensity of ionospheric scatter signals for the paths iceland
england and massachusetts labrador are plotted  decreases in intensity
indicate a large excess of ioniging particles with rigidities above
geomagnetic cut off at the path mid points
   /
1124
roughness of the moon as a radar reflector  measurements have been
made at a wavelength of ten cm and pulse duration of five of the
angular scattering properties of the moons surface  from the results
a law of scattering has been obtained which is consistens with scattering
from a rough surface which has irregularities much greater than
a wavelength and a horizontal scale equivalent to about twenty times
the vertical deviations
   /
1125
electric discharge caused by meteorites moving in the earths atmosphere
the passage of meteorites through the atmosphere is followed by the
formation of a trail of ionized gas about ten km long and of five
m radius  the luminosity of the meteorite is attributed to a corona
discharge in the front of the trail and in the case of bright meteorites
in strong electric fields this discharge becomes a spark discharge
of the lightning type
   /
1126
relations between the electric and magnetic fields of very long period
induced in a medium of variable conductivity  a model of ground conductivity
distribution is derived which closely represents the conditions
indicated by observations of geomagnetic and geoelectric pulsations
   /
1127
magnetic storms and cosmic radio noise  in addition to changes in
absorption due to the d layer nd to the proximity of the f layer
critical frequency a storm time variation was found the magnitude
of which depends on local time
   /
1128
solar terrestrial relationships  a note on the proton density in
interplanetary space required to explain geomagnetic disturbances
in terms of the hydromagnetic wave theory
   /
1129
some radio aspects of the international geophysical year  a brief
review of the results of investigations into long distance radio
propagation polar regions of the ionosphere and rocket and satellite
measurements of electron density in the upper atmosphere
   /
1130
amateur radio participation in the i  g  y  outline of the u  k
amateur program and a brief report of some results obtained from
studies of auroral propagation
   /
1131
radiation measurement during the flight of the second cosmic rocket
the equipment used consisted of tix gas discharge counters and four
scintillation counters  measurements were carried out from the centre
of the earth and from the surface of the moon  graphs show the trajectories
of the first and second rocket in the earths magnetic field
the space location of the radiation belt is examined and the dependence
of the radiation intensity on the distance from the earth considered
   /
1132
motion of a satellite in the earths gravitational field  the equations
of motion of a satellite are given in a general form taking account
of the precession and nutation of the earth
   /
1133
secular and periodic motions of the node of an artificial earth satellite
   /
1134
analysis of the orbits of the ruttian satellites
   /
1135
experiments on cosmic radiation by means of artificial satellites
   /
1136
radiation information  the data indicate that the radiation intensity
varies with altitudes
   /
1137
corpuscular radiation experiment of satellite iota  the equipment
including the calibration of the detectors and the telemetry code
are described and samples of recordings are shown  international
participation in recording the signals is invited
   /
1138
the determination of ionospheric electron content and distribution
from satellite observations  the theory of the determination is given
for measurements of total rotation of angle of polarization and also
of its rate of rotation  modifications to the simple theory and sources
of errors are discussed  observations made using sputnik three have
disclosed a diurnal variation in totol electron content and data
relating to the proportion of the total content which lies below
the f layer peak  the effect of magnetic disturbances is described
   /
1139
statistical consideration of the structure of atmospheric refractive
index
   /
1140
artificial electron clouds  values have been derived for diffusion
coefficients chemical yield thermal ionization efficiency and wind
velocity and shear
   /
1141
the origin of nitrogen ionization in the upper atmosphere
   /
1142
some problems concerning the terrestrial atmosphere above about the
hundred km level  rocket and satellite data are considered in a survey
concerned with the general structure of the thormosphere
   /
1143
measurement of positive ion density in the ionosphere  the design
of a suitable rocket borne probe is discussed and a small meshed
spherical type is adopted  laboratory experiments designed to investigate
the characteristics of such a probe are described
   /
1144
vertical transport of electrons in the f region of the ionosphere
an expression is developed for the velocity and can be evaluated using
n profiles  the results for equatorial stations show that the velocity
is mainly downwards at night and upwards by day
   /
1145
on the question of the continental effect of the f layer  analysis
of f data indicates an increase in day time ionization during the
summer months observed by u  s  s  r  stations in central asia compared
with data obtained by west european stations  the evening rise in
f appears much less pronounced for stations in central asia where
the maximum usually occurs at local noon  this continental effect
causes difficulties in the interpolation required for the preparation
of m  u  f  charts
   /
1146
further studies of spread f at brisbane  vertical incidence ionograms
and directional measurements on oblique incidence signals indicate
that the spread f phenomenon is due to large ripples with a wavelength
of twenty to over one hundred km  seasonal and sunspot variations
in the phenomenon are described  model ionization distributions are
constructed and ray paths drawn which may explain various types of
spread f  the amplitude of the ripples seems to increase with the
height of the f layer
   /
1147
ionospheric absorption investigations at hawaii and johnston island
the absorption of cosmic noise at thirty mcs varies in such a way
as to suggest that the patches of absorption are less than one thousand
km in size  the variations are not correlated with the spread f or
with the sporadic e phenomena but are correlated with f suggesting
partial reflection of the cosmic noise by the f layer
   /
1148
radio wave propagation characteristics of a simple ionospheric model
based on rocket data
   /
1149
the reflexion of radio waves from a stratified ionosphere modified
by weak irregularities part two
   /
1150
entry of high energy particles into the polar ionosphere
   /
1151
the height of f layer irregularities in the arctic ionosphere
   /
1152
the exploration of the terrestrial exosphere  a review of scientific
investigations of the composition and structure of the exosphere
dealing particularly with the observation of whistlers and with results
obtained from satellite and rocket measurements
   /
1153
properties of the upper atmosphere and their relation to the radiation
belts of the earth  a new theory is outlined which gives the distribution
of density with altitude for a planetary exosphere in the absence
of thermodynamic equilibrium  the results differ considerably from
those based on a hydrostatic equation
   /
1154
a comparison of intracloud and cloud to ground lightning discharges
experimental results are discussed together with possible discharge
mechanisms
   /
1155
atmospherics on twenty kcs at the time of local aurorae  atmospherics
have been recorded on each of the thirty occasions when a strong
aurora has been observed  this enhancement is attributed to reflections
from ionized strips associated with the aurorae
   /
1156
controlled rectification using transistors  the suitability of a
transistor as a switching device is discussed in terms of its operating
characteristics and an equivalent circuit is derived  a switched
rectifier circuit for use in a chopper type d  c  amplifier is described
which incorporates a transistor oscillator providing the control
frequency
   /
1157
electronic computers  annual review of international developments
in digital and analogue computer design and installations
   /
1158
physical versus logical coupling in memory systems  an evaluation
is made of the optimum size of cell for maximum information storage
   /
1159
a small high speed transistor and ferrite core memory sistem  a
description is given of the design and operation of a four hundred
bit storage system used in a time division switching system where
the number of circuits controlled required a simultaneous read out
of twenty bits
   /
1160
the persistor a superconducting memory element  the persistor consists
of a superconducting inductor in parallel with a normally superconducting
element  a current pulse causes a current to be established in
the persistor another similar pulse causes no change but one of opposite
sign reverses the current
   /
1161
tunnel diode logic circuits  equations tre derived relating diode
tolerances to those of tther circuit components for analogue threshold
logic and majority logic use  practical lunnel diode logic circuits
are believed to be possible
   /
1162
a new class of switching devices and logic elements  with switching
devices employing microwave valve elements switching at one mus intervals
becomes possible  an experimental travelling wave interaction
type valve has been built to demonstrate the ability of one microwave
signal to control another
   /
1163
parametron computer circuits  the characteristics of parametrons
and applications are discussed
   /
1164
ripple type time delay networks using elliptic functions  the design
of simulation networks in the frequency domain is presented
   /
1165
magnetic amplifier binary to analogue conversion  three saturable
reactors are used to convert a ten digit input to an analogue voltage
driving a servo magnetic amplifier
   /
1166
composing with electronic computers  twr basic methods of musical
composition by computer are discussed to illustrate the simulation
of luman thought processes
   /
1167
synthesis of switching functions by linear graph theory
   /
1168
survey of thermistor characteristics  characteristics and applications
are tabulated for different constructions of the two basic types
of thermistor
   /
1169
the long term stability of fixed resistors  an investigation of the
causes of long term failure nder practical conditions of use or storage
test methods are critically discussed
   /
1170
a mathematical model for a magnetic amplifier reactor core  form
domain theory a model for the prediction of core behaviour is proposed
   /
1171
two step switching of saturable reactors  the performance of the
mathematical model of woodson when subjected to abrupt flux reversals
is compared with experimental data for orthonol cores
   /
1172
d  c  charged magnetic pulse modulator  design details and performance
results are quoted for an experimental modulator consisting of one
charging and two pulse modulating stages and capable of delivering
a peak power output with a pulse width into a restive load
   /
1173
the persistor a superconducting memory element
   /
1174
some mechanisms of failure of capacitors with mica dielectrics  an
analysis of failures with a description of some methods of examination
and dissection giving minimum loss of evidence
   /
1175
the representation of multipoles by scattering matrix  the scattering
matrix is defined and its properties are summarized  the application
of the matrix to the calculation of multipole networks including
quadripoles is detailed with tables giving the matrices of some basic
circuits
   /
1176
differentiating and integrating circuits with positive operational
feedback  a general method of analysis and design is presented and
illustrated with a particular circuit
   /
1177
valve circuits with normalized transfer function for distortionless
electrical differentiation  the circuit parameters and operating
characteristics of several differentiating circuits for obtaining
first and second order derivatives are given
   /
1178
an equivalent circuit for transistor mixers  an equivalent circuit
is derived for the earthed emitter configuration based on giacolettos
circuit moortgat pick  experimental confirmation of the validity
of this theory is obtained
   /
1179
oscillators and their modes of oscillation  a classification of oscillators
in three types is proposed based on the parameters of the passive
frequency determining quadripole which together with an active quadripole
constitutes the oscillator  several basic circuits are analysed
in this way and the q factor of their modes of oscillation is evaluated
   /
1180
a microwave meacham bridge oscillator  a high stability microwave
oscillator has been constructed consisting of a travelling wave amplifier
cavity microwave bridge and bolometer  experimental results are
compared with theory
   /
1181
quantitative analysis of a nonlinear second order differential equation
of a self oscillating system with a limited increment region
   /
1182
stability problems in monostable multivibrators  the influence of
the amplitude of trigger pulses on multivibrator operation and the
dependence of pulse width on the trigger frequency are discussed
   /
1183
a graphical analysis of the blocking oscillator  a detailed analysis
of the circuit and its mode of operation is given and a practical
design precedure is described
   /
1184
transistor monostable circuits  cross coupled and emitter coupled
circuits are analysed to determine the circuit characteristics  results
obtained with two practical circuits show good agreement with theory
   /
1185
a passive waveform shaping circuit  an inductance and suitable semiconductor
diodes are combined  applications discussed include a  change
in phase of a square wave b  mark space ratio modulation of a square
wave c  pulse generation lengthening and delay
   /
1186
a simple circuit for producing a voltage proportional to the width
of a repetitive pulse  details are given of a circuit for deriving
a direct voltage from train pulses of width proportional to the flow
rate of a liquid  the voltage drives an integrating motor via a push
pull cathode follower
   /
1187
complementary transistor circuits  by the use of p  n  p  and n
p  n  transistors connected back to back a series of circuits become
available for which there is no valve equivalent  they are symmetrical
in operation but do not necessarily require balanced transistors
   /
1188
derivation of a frequency multiple of a variable frequency  a mask
is placed across the face of k c  r  o  displaying the variable frequency
f  the mask outline is sinusoid representing the frequency multiple
n  it is viewed by a photocell whose output varies at a frequency
nf  equations defining the mask outline for any value of n are given
   /
1189
a pulse delay system  details are given of a phase shift circuit
followed by a pulse shaping stage a maximum delay of about one ms
can be achieved
   /
1190
stagger tuned and bandpass coupled circuits in wide band i  f  valve
amplifiers  formulae are derived for the replacement of any two equally
detuned circuits in a stagger tuned amplifier by a single bandpass
coupled pair
   /
1191
a new asymmetric push pull amplifier with extremely low internal
impedance  an output amplifier circuit is described in which the
phase splitting triode is incorporated in one of the push pull arms
   /
1192
contribution on the amplifier with extremely low internal impedance
detailed investigation of the operation of a two stage valve amplifier
with combined negative voltage feedback and positive current feedback
   /
1193
elimination of coupling problems in multistage magnetic amplifiers
operational principles and design criteria are considered for two
stage half wave and full wave amplifiers with synchronous switch
coupling
   /
1194
theory of three phase bridge magnetic amplifier part one steady state
a discussion of operation at minimum load with the control circuit
either open or closed is followed by a study of conditions under
normal excitation from minimum to half load
   /
1195
miniature high frequency magnetic amplifiers or magnetic memory sensing
a report of measurements on ferrite and metal tape cores with single
turn control windings and asymmetrical excitation at frequencies
   /
1196
transistors in audio and carrier frequency amplifiers  the characteristics
of common emitter transistor amplifiers in relation to requirements
for communication systems are discussed
   /
1197
an introduction to the theory of solid state masers basic theory
is summarized and used to evaluate the engineering characteristics
of a travelling wave maser employing the comb type of slow wave guide
   /
1198
nuclear magnetic resonance maser
   /
1199
quantum mechanical semiconductor generators and amplifiers of electromagnetic
oscillations  a note of the possibility of using the electron
transitions between the conduction or valence band and the donor
or acceptor impurity levels to obtain maser action
   /
1200
theory of single resonance parametric amplifiers  a parametric amplifier
that supports a resonance at the idler frequency only is capable
of unlimited gain when operated either as a straight through amplifier
or as a lower sideband ur converter  this makes feasible a continuously
tunable parametric receiver
   /
1201
unidirectional paramagnetic amplifier design  the theory and design
of a cavity paramagnetic amplifier are given  the faraday effect
is used to obtain unidirectional amplification which can result in
noise figures an order of magnitude better than other systems
   /
1202
theory of the diode reactance amplifier with parallel circuits  detailed
treatment of the theory and design of parametric amplifiers consisting
of a variable reactance semiconductor diode coupling two resonant
circuits  minimum noise conditions are evaluated and design parameters
are tabulated for three basic types of circuit
   /
1203
low noise parametric amplifier  the n ise temperature and pump power
xsing a semiconductor diode can be accurately predicted from a measurement
of the diode and circuit parameters the ultimate lower noise
limit depends on the product of diode cut off frequency and the normalized
capacitance swing
   /
1204
space charge wave parametric amplifiers
   /
1205
diode capacitors for parametric amplification
   /
1206
limitations in squaring with simple valve circuits of wide bandwidth
the errors to be expected from squaring circuits  based on curvature
of a valve characteristic with input applied to one electrode and
b  using separate control electrodes with antiphase inputs are compared
measurements have been made on the latter type
   /
1207
network response to transient frequency modulation inputs  an approximate
method is developed for calculating the response when the input
modulation varies rapidly during short periods e  g  when television
or pulse signals are used for frequency modulation
   /
1208
modulation distortion in frequency modulation by special frequency
band  the distortion factors are calculated which arise in two three
or four double tuned critically coupled band filters used in f  m
receivers under the assumption of linearized phase characteristics
and for two different selectivity specifications  the amplitudes
of combination tones are calculated for the case of three filters
when two f  m  signals are applied
   /
1209
light waves in crystals in the region of exciton absorption and the
impurity photoeffect  in the frequency range for which the refractive
index is much less than unity the amplitudes of normal and longitudinal
waves in a cubic crystal greatly exceed the amplitude of the incident
wave  the photoionization of impurities is therefore much more intense
this explains the sharp maximum in the internal and external photoeffects
observed experimentally in the frequency range corresponding to
exciton absorption
   /
1210
experimental investigation of charge formation on a dielectric surface
under the influence of electron bombardment part two  the kinetics
of the formation of an actual charged spot produced on the surface
of a dielectric by an electron beam have been investigated  the instrument
and method are described and it is shown that the conditions
for the formation of positive and negative spots are different
   /
1211
contribution to the theory of ferroelectric polarization curves
the principles of the polarization theory for single and many domain
ferroelectric crystals with one or two curie points are developed
for weak strong and medim fields  in contrast to magnetization curve
theory rotation can be neglected in the first approximation
   /
1212
electron resonance in crossed electric and magnetic fields  a note
on the electric field dependence of the period of revolution of an
electron in a semiconductor in crossed fields
   /
1213
thermoelectric phenomena in strong magnetic fields in metals possessing
various mermi surfaces  the asymptotic variation of the thermoelectric
force peltier and thomson coefficients for metals with closed fermi
surfaces and open surfaces of the corrugated cylinder and space net
types is investigated on the basis of the quasiclassical theory of
kinetic phenomena
   /
1214
determination of the shape of a relativistic electron beam  brief
mathematical analysis of an axially symmetric thin electron beam
the cross section of which varies along the axis of the beam the
movement of the electron beam being assumed adiabatic
   /
1215
determination of trajectories of relativistic charged particles in
electric and magnetic fields by the adams method of finite differences
   /
1216
plasma oscillations of a large number of electron beams  longitudinal
oscillations of a large number of electron beams are investigated
the problem of passing to the limit of a continuous velocity distribution
is considered in detail
   /
1217
electric field distribution in an ionized gas part two  the method
described earlier baranger and mozer is used to calculate the probability
distribution of the l  f  component of the field at a neutral
point and also the distributions of the l  f  component at an ion
and of the h  f  component at an electron
   /
1218
transport phenomena in slightly ionized gases high electric fields
an investigation of the variation with electric field of a number
of transport properties in the presence of a magnetic field perpendicular
to the electric field and temperature gradient in the gas
   /
1219
the equation of state of a plasma  the free energy of a completely
ionized gas is given in the form of an expansion in terms of the
density of interacting particles
   /
1220
anomalous electron scattering and the excitation of plasma oscillations
an investigation of the interaction of an electron beam with an independently
formed plasma  the observed data can be explained by assuming
that the electrons form clusters which interact coherently with the
plasma
   /
1221
oscillations of a plasma beam in a magnetic field at frequencies
close to the cyclotron frequency  a method is described by which
plasma oscillations have been observed in hydrogen at frequencies
lower than the ion cyclotron frequencies  the absorption of r  f
power by ions which rotate in the magnetic field is detected by the
change in q of an oscillator circuit
   /
1222
hydromagnetic waves in plasmas  theoretical investigation of wave
propagation along and across a strong magnetic field in plasma taking
account of electron diffusion
   /
1223
note on perturbation of a uniform magnetic field by a cube of magnetic
material
   /
1224
on the theory of weak ferromagnetism
   /
1225
ferromagnetism of an electron gas  a study is made on the basis of
the bohm pines collective description of electron interactions
   /
1226
excitation of spin waves in ferromagnets eddy current and boundary
condition effects  the boundary condition for transverse magnetization
is derived when there is a surface anisotropy field  spinwave modes
can be excited by a uniform r  f  field and the power absorbed in
each mode in an insulator can be calculated  the eddy currents have
a large effect only on long wavelength spin waves
   /
1227
theory of paramagnetic resonance in systems containing two kinds
of magnetic moment  equations are derived for the partial magnetizations
in a weak variable magnetic field  relaxation times and resonance
frequency shift are calculated
   /
1228
spin lassice relaxation effects observed in the continuous power
saturation of paramagnetic lines  the dependence of the conventional
saturation parameter on the incident microwave power is considered
for lorentzian shaped paramagnetic lines
   /
1229
reciprocity theorems for electromagnetic fields whose time dependence
is arbitrary
   /
1230
multilayer absorbers for electromagnetic waves  the absorbing power
of structures is discussed which consist of two or more layers of
loss free dielectric and thin resistive material arranged alternately
the reflection coefficients are calculated for a number of such structures
which are treated as resonance absorbers
   /
1231
high frequency diffraction of plane waves by an infinite slit for
grazing incidence
   /
1232
high frequency diffraction of electromagnetic waves by a circular
aperture in an infinite plane conducting screen
   /
1233
reflection of an electromagnetic wave from a plasma moving through
a dielectric in a constant magnetic field  mathematical treatment
of the reflection of a retarded e  m  wave from a moving plasma in
a magnetic field directed parallel to the plasma motion  expressions
are derived for the frequency and amplitude of the reflected wave
the dependence of phase velocity on magnetic field intensity is determined
and two refracted waves are defined
   /
1234
validity of the theory of double stream amplification  recent misunderstandings
concerning the validity of the original analysis of the
interaction of moving ion or electron streams are clarified
   /
1235
theory of diffraction in microwave interferometry  the theory is
applicable to michelson and fabry perot interferometers
   /
1236
some solutions for electromagnetic problems involving spheroidal
spherical and cylindrical bodies  results are given for the l  f
response to an oscillating magnetic dipole by conducting bodies of
simple shape
   /
1237
effect of specimen shape on ferromagnetic resonance in a strong radio
frequency field  an analysis of the exact solutions of the landau
lifshits equations  an expression is derived for the threshold field
above which instability in the motion of the magnetization vector
begins  for resonance field strengths the height of the absorption
peak decreases and its width increases
   /
1238
nuclear magnetic resonance maser  a detailed investigation of a two
level weak field maser type self oscillator based on nuclear spin
rotation in a circulating liquid under conditions of rapid adiabatic
passage through resonance  applications for magnetic field and relaxation
time measurements are discussed
   /
1239
broadband millimetre wave paramagnetic resonance spectrometer  the
specimen and waveguide which can be cooled by means of a cryostat
are placed between close pole pieces giving high uniform magnetic
fields  design details and some measurements on zero field splittings
are given
   /
1240
new analysis of the polarization of radiation and the faraday effect
in terms of complex vectors  the properties of the polarization ellipse
are deduced in terms of the ratio of the cartesian components of
the complex electric vector of a beam of radiation by utilizing the
argand representation of a real two dimensional vector as a complex
number  the two components of a beam that are accepted and rejected
by a polarizer or a radio antenna are considered as orthogonal components
in the directions of two complex orthonormal vectors  the intensities
of the corresponding components of a polarized beam are derived and
represented on the poincare sphere  the methods are then applied
to the important radio case of the faraday effect in a uniform magneto
ionic medium  finally the measurable quantities characterizing a
beam of partially polarized radiation are obtained from a diagonalization
of the complex polarization tensor that specifies the beam
   /
1241
absorption and emission spectra of an electron in a one dimensional
deep trap
   /
1242
generalization of band theory to include sefl energy corrections
an investigation of the corrections to ordinary band theory due to
dielectric effects
   /
1243
maximum angular accuracy of tracking a radio star by lobe comrarison
   /
1244
the north south branch of the great interferometer of the nancay
station  a brief description of the aerial system and receiving equipment
which is being used in conjunction with the e w interferometer
for a detailed study of the sun  the n s branch operates at mc s
and has eight parabolic mirrors ten m in diameter spaced along a
track  provision is made for adjusting the declination of the beam
   /
1245
microwave absorption and emission in the atmosphere of venus  theoretical
considerations are presented suggesting that measurements in the
mm range may give information on the atmosphere below the cloud layer
of the planet
   /
1246
the source of radiation from jupiter at decimetre wavelengths part
two cyclotron radiation by trapped electrons
   /
1247
ionospheric modification of the radio emission from jupiter  the
experiment of gardner and shain has been repeated using two identical
receivers  some correlation is found between records at the two sites
but there is also evidence of serious distortion due to terrestrial
effects
   /
1248
balloon study of high altitude radiations during the international
geophysical year
   /
1249
observations of the van allen radiation regions during august and
september part one  results are given of a preliminary analysis of
data obtained from equipment flown on explorer sixth  in addition
to the inner and outer zones a stable intermediate zone was detected
the outer zone intensity showed a large decrease following a sudden
commencement but subsequently increased to be greatly in excess of
its prestorm level  comparison is made with other measurements of
the radiation zones
   /
1250
particle fluxes in the inner radiation belt
   /
1251
roughness of the moon as a radar reflector  radar observations of
the distribution of slope of the lunar surface made by hughes are
found to be in good agreement with optical measurements when the
slope angle is greater
   /
1252
radar determination of the scattering properties of the moon  results
obtained by feinstein are modified to take into account the curvature
of an irregular reflecting surface and applied to problems associated
with scattering from a lunar surface which has two dimensional corrugations
   /
1253
sporadic shower properties of very small meteors  a long term radar
survey shows sporadic meteoric particles to be distributed in a vast
number of relatively small groupings
   /
1254
observed magnetic effects from meteors  an analysis of subaudio fluctuations
in the geomagnetic field indicates that meteoric activity and
the average level of fluctuations are related
   /
1255
experimental studies of meteor echoes
   /
1256
properties of the solar wind during sunspot minimum
   /
1257
three dimensional considerations for current system of geomagnetic
variations part two sq field
   /
1258
on the position of the focus of the geomagnetic sq current system
a review of present knowledge of the sq foci discussion of the cause
of changes in the sq field and a description of problems relating
to the determination of the sq focus  the foci in the potential fields
of geomagnetic dq variations may be taken as approximately indicating
the positions of ionospheric sq current foci
   /
1259
concerning the nature of short period magnetic micropulsations  world
wide and local effects are discussed from the point of view that
the pulsations originate within the ionosphere
   /
1260
magnetic micropulsations pulsating aurora and ionospheric absorption
increases in cosmic noise absorption coincide with magnetic and auroral
pulsations
   /
1261
studies on sudden commencements of geomagnetic storms using i  g
y  data from united states stations  report of a study of geomagnetic
storm variations recorded over a period of one year from july at
a network of stations
   /
1262
three dimensional consideration for current system of geomagnetic
variations part one current flow for polar elementary storm within
a spherical conducting shell
   /
1263
preliminary results from the space probe pioneer fifth  cosmic ray
measurements show that a  forbush decreases are not dependent on
the presence of the earths field as they occur out in space b  solar
flare particles producing polar cap absorption are not stored in
the geomagnetic field and c  solar production of energetic electrons
is not restricted to periods of flare activity
   /
1264
characteristics of the extraterrestrial current system explorer sixth
and pioneer fifth  magnetometer measurements of the earths field
are consistent with a toroidal ring current flowing in the magnetic
equatorial plane
   /
1265
some preliminary results of the pioneer fifth magnetometer experiment
the sudden increase in magnetic field strength during solar activity
suggests that collisionless magnetoacoustic waves may be formed at
the boundary between the earths field and the interplanetary field
which is put at thirteen earth radii
   /
1266
induction drag on a large negatively charged satellite moving in
a magnetic field free ionosphere
   /
1267
the influence of the solar radiation pressure on the motion of an
artificial satellite  results of theoretical investigations of the
radiation pressure perturbation have been applied to orbital calculations
for vanguard one producing significant perturbations in its perigee
height  in the case of a satellite with a large area mass ratio the
major terms introduced by solar radiation pressure can reduce the
perigee distance at the rate of km day
   /
1268
final months and descent of satellite sputnik three  a report of
the progress from may until its descent on april and a brief discussion
of the main features of its lifetime  for earlier progress see january
   /
1269
the upper earth atmosphere according to satellite measurements  review
of results obtained from measurements on the first five earth satellites
   /
1270
first results of satellite observations for information on wave propagation
review of early radio and radar observations of earth satellites
and summary of results obtained relating to ionospheric phenomena
   /
1271
frequency scintillations of satellite signals before and after the
argus experiments
   /
1272
a convenient method of getting representative ionospheric heights
a simple method is described for obtaining electron density profiles
monthly median hf curves are drawn for each hour and then reduced
to true height profiles by any standard method
   /
1273
the joint use of the ordinary and extraordinary virtual height curves
in determining ionospheric layer profiles  an extension of buddens
matrix method for determining ionospheric layer profiles  errors
are reduced by using the extraordinary virtual height curve as well
as the ordinary curve
   /
1274
the formation of the d region of the ionosphere  a review of theoretical
studies of the ionization process in the d region  it is possible
to explain normal conditions of ionization by cosmic rays and lyman
radiation  conditions due to solar flares must be explained by x
rays  above km the ionization is related to the formation of the
e layer
   /
1275
field aligned ionization  field aligned ionization in the e and f
regions may result from leakage of particles from the radiation belts
   /
1276
longitude effect in temperate zone sporadic e and the earths magnetic
field  a correlation is shown to exist in both northern and southern
temperate zones between the magnitude of the horizontal component
of the earths magnetic field and the percentage of time  this is
considered with reference to the longitude effect investigated by
smith and finney and it is suggested that the movement of ionization
by winds or electric fields is the most likely source of e
   /
1277
drift measurements at kjeller on the ionospheric f region  results
are given of measurements made at kjeller norway mostly during january
and february  the mean drift velocity was found to be towards the
west at night and the east during the day  some measurements on sporadic
f echoes are reported
   /
1278
inferred temperature variations at the f peak  the scale height at
the f peak has been estimated using data on the total electron content
of the ionosphere obtained from the faraday rotation of lunar radio
echoes and data obtained from vertical incidence soundings  the scale
height varies with time probably as a result of temperature variations
the observed scale heights are in good agreement with a model atmosphere
based on rocket and satellite observations
   /
1279
vertically travelling shock waves in the ionosphere  ionospheric
phenomena at vertical incidence observed in the vicinity of ground
based atomic explosions are interpreted in terms of acoustic and
hydromagnetic wave propagation
   /
1280
oxygen red line in the night airglow and ionospheric f region  a
statistical analysis of spectroscopic data indicates that the intensity
of the red radiation and the maximum electron density of the f region
are related
   /
1281
some characteristics of the d region ionization during auroral activity
in north sweden d layer ionization during aurorae is closely associated
with sudden increases in auroral activity and extends down to about
sixty five km  the latitude variations of this layer are discussed
and it seems likely that the ionization is due both to primary electrons
and secondary x rays
   /
1282
v  l  f  propagation effects of a d region layer produced by cosmic
rays
   /
1283
a new mechanism for accelerating electrons in the outer ionosphere
an experiment is outlined to produce high energy electrons in the
ionosphere using e  m  radiation from a ground based l  f  transmitter
the principle is adaptable for use in a satellite or space probe
   /
1284
scattering of radio waves by electrons above the ionosphere  by measuring
the overall intensity of the scattered spectrum it should be possible
to estimate electron density and temperature if better resolution
were possible the atomic weights of the ions present could be obtained
   /
1285
lightning and charge storage  a lightning flash consisting of current
surges of which twenty six were leader return stroke combinations
and having a total duration of two seconds is described
   /
1286
the design and use of instruments for counting local lightning flashes
the instrument adopted as a standard for assessing local activity
triggers on a field change of three vm  the need for an international
standard is stressed
   /
1287
theory of auroral structures  a simplified theoretical examination
of the structure of visual aurorae
   /
1288
movement of auroral ionization  a ote on the apparent discrepancies
between movements deduced from visual and radar observations
   /
1289
observations of the aurora australis at new zealand antarctic stations
during i  g  y
   /
1290
correlation studies of radio aurora magnetic and earth current disturbances
the diurnal variation of the rate of auroral echo occurrence
appears to be similar to that of moderate perturbations of h  a relation
is suggested between magnetic perturbations and the reversal of direction
of auroral ionization drift from west to east at about local midnight
   /
1291
on the geometry of radio reflections from aurora  the observed characteristics
of auroral radar echoes are explained by assuming that echoes
arise by means of volume scattering from configurations of ionization
similar to those observed visually  the importance of allowing for
the radar pulse length and aerial beam width is stressed
   /
1292
the association of visible auroral forms with radar echoes  an extension
of earlier work to detect a more detailed correlation between echoes
and specific visible auroral forms
   /
1293
an analysis of some statistical properties of auroral radar reflections
and their relationships to the detection capabilities of the radar
expressions are derived from an analysis of protracted observations
relating radar parameters to echo statistics
   /
1294
very low frequency atmospherics  report on measurements of atmospherics
in the frequency range by means of specially designed equipment
the results are discussed with reference to measurements made by
others  a sinusoidal signal of about nine cs was observed which may
be due to resonance of the system earth ionosphere
   /
1295
geomagnetic noise  results of observations made are compared with
estimates of the noise intensity to be expected from a cherenkov
radiation mechanism
   /
1296
geomagnetic disturbances and five kilocycles per second electromagnetic
radiation  out of isolated noise bursts at five kcs in australia
associated with positive bays in the h component of the earths field
noise bursts followed the occurrence of thirty magnetic sudden commencements
with a delay of hours but on four occasions there was no delay
   /
1297
on the stability of random systems and the stabilization of deterministic
systems with random noise  a general theory of mean square stability
of random linear systems in which parameters may vary as white noise
processes is developed and applied to a rlc circuit  the possibility
of stabilizing unstable deterministic systems by means of random
noise is predicted
   /
1298
a condenser memory unit for improving signal to noise ratios  description
of a unit containing thirty low leakage capacitors which can store
information for periods up to several hours thirty two channels may
be scanned in ten sec  the unit has been used in investigations of
twilight spectra with photoelectric and photo conductive spectrometers
   /
1299
a sensitive transistor recording pen amplifier  details of a bridge
circuit with low temperature drift are given
   /
1300
a magnetic amplifier silicon transistor power supply for missile
application  a detailed description of a power supply system producing
seven regulated direct voltages and two r  m  s  regulated alternating
voltages  a magnetic amplifier is incorporated in each channel for
regulation and al direct voltages are derived from the same h  f
transistor inverter
   /
1301
a stabilized and programme controlled power supply using positive
feedback  a power supply for a mass spectrometer magnet is described
with an output continuously variable
   /
1302
limitations and possibilities for improvement of photovoltaic solar
energy converters part one considerations for earths surface operation
the possibilities of improving the performance of the single si solar
cell are considered as these are limited the use of other materials
and the development of a multilayer and a multiple transition cell
are examined and found to give larger theoretical efficiencies
   /
1303
the wind driven power supply for the decimetre wve radio relay station
schoneberg eifel and the experience gained with it  details are given
of the wind driven generators and ancillary equipment used in a twenty
two month trial of the system as the main power supply for radio
link stations  records of wind power availability and utilization
made by specially designed apparatus are analysed and discussed
   /
1304
the parallel and series operation of germanium rectifiers  the permissible
ratings of germanium rectifiers operated in series and parallel
connections have been calculated for the cases where load balancing
resistors are placed in parallel and in series respectively with
the individual rectifiers  transistorized power supplies for a mass
spectrometer  magnet current supply and filament emission control
circuits of low power dissipation are described
   /
1305
hall effect multipliers  the design of the hall generator comprising
between ferrite plates is given together with details of suitable
transistor amplifier circuits  curves showing the performance of
the unit for frequencies included
   /
1306
an improved film cryotron and its application to digital computers
a crossed film cryotron formed by deposition on an insulated superconductor
is described and its operation is analysed
   /
1307
electrical read out from thin ferromagnetic films  a metred of a static
coupling and amplification is described which gives a read out with
good signal noise ratio
   /
1308
electronic digitizing techniques  a  electronic digitizing techniques
b  a simple analogue to digital converter with nonlinearity compensation
c  the step by step potentiometer as a digitizer  d  an analogue
digital converter with long life  e  a wide range fully automatic
digital voltmeter  f  an all electronic four digit digital volmeter
   /
1309
three hole cores for coincident fluy memory  coincident flux operation
permits pulse currents that are not limited by coercive force threshold
shorter read write times and greater tolerance to temperature and
pulse current variations are obtained
   /
1310
conical coaxial capacitors and their advantages  in an example cited
the ratios of maximum to minimum capacitance for disk cylindrical
and conical capacitors are respectively  an approximate equation
is derived for the conical  capacitor and close agreement is shown
between computed and measured values of capacitance
   /
1311
capacitor calibration by step up methods
   /
1312
a  tive power tr  nsfor by linear quadripoles  the transfer of power
through an arbitary linear quadripole is considered as a function
of matching conditions source impedance input and output impedances
and gain of the quadripole
   /
1313
connection and measurement of transform functions on an analogue computor
the transfer function of linear systems is split into products
of partial transfer functions which facilitates the solution of network
problems by analogue computer  circuits representing the partial
functions are given and methods of measuring the frequency and time
characteristics of filter networks are described
   /
1314
three branch reactive sections for ladder filters with one or two
cut off frequencies  a graphical method is proposed for the synthesis
of three branch networks consisting of reactances which have no mutual
inductive coupling
   /
1315
dissipative networks with third order maximally flat amplitude characteristics
an analysis is made of dissipative low pass networks a simple
chande of t  e frequency variable allows the results to be applied
to bead pass networks  for the case of narrow band operation the
concept of quarter wave coupling is developed and the equivalent
triple tuned circuit conf  guration is derived
   /
1316
zig zag filters  a systematic method of calculating zig zag sections
for baedpass ladder filters is described
   /
1317
filter calculations using the template method  a part graphical method
for calculating filter characteristics is described which has been
developed using frequency transformations
   /
1318
echostant matching  systematic matching of filter ladders calculated
section by section
   /
1319
ricurrence formulae for the calculation of the characteristic function
of filters with tchebycheff pass band behaviour
   /
1320
matching of image parameter filters and associated problems
   /
1321
the physical realizability and realization of linear phase shift
networks
   /
1322
restrictions imposed upon the unit step response of linear phase
shift networks  limits are defined for the rise time and overshoot
of the unit step response of networks free from phase distortion
   /
1323
the design of delay equalizers using the analogue method  a resistance
network analogue and its application to the design of a television
circuit delay equalizer are described
   /
1324
a circuit for the electrical integration and differentiation of periodic
phenomena  integration or differentiation is carried out by means
of two independent rc or rl sections separated by a valve stage
   /
1325
synthesis of driving foint impedances with active rc networks  a
general metrod is presented for realizing any real rational driving
point function using rc networks and one type of active element leading
to a simple structure  biquadratic impedance functions are considered
in detail
   /
1326
noise in oscillators  effects of white noise of thermal of electronic
origin on the initiation of oscillations and on perturbations in
amplitude and phase of sustained oscillations are analysed
   /
1327
background noise in nonlinear oscillators  an examination of the
effects on self excited oscillators of wide bead noise at or near
the frequency of oscillation
   /
1328
the behaviour of nonlinear oscillating systems fn the presence of
noise
   /
1329
on the resolving time and flipping time of magnetoresistive flip
flops  the time constant of the exponential approach to the stable
states is shown to be a fair approximation for the flipping time
of a bridge type magnetoresistive flip flop is of the order for materials
at present available  the method of calculating flipping time
is extended to more general networks and the dependence of the flipping
time on t  e incoming pulse is considered
   /
1330
impulse governed oscillator techniques part one  the general principles
of i g o  techniques are discussed special circuits and theoretical
data will be given in subsequent issues
   /
1331
monochromaticity and noise in a regenerative electrical oscillator
expressions are derived for the departure from monochromaticity of
a regenerative oscillator represented by an equivalent rlc circuit
haing a negative resistance in parallel with r  the intensity and
band width of the thermal noise generated in the oscillator by resistance
r are also considered
   /
1332
frequency stability of a stable multivibrators using transistors
the dependence of multivibrator frequency on transistor characteristics
and operating conditions is investigated and rules for an optimum
design are derived
   /
1333
synthesis of a circuit for flywheel synchronization
   /
1334
a special effect in some pulse systems  the order of the transfer
function of pulse driven closed circuit systems can under certain
conditions be increased by one degree relative to the corresponding
steady state system  the reasons for this effect are given with experimental
confirmation
   /
1335
parametric excitation of harmonic oscillations in a linear oscillating
circuit with nonperiodic variation of its parameters with time  conditions
for harmonic generation by nonperiodic variation of r l and c
are established
   /
1336
harmonics from a microwave gas discharge
   /
1337
amplifier with stagger tuned circuits with maximum linearity of the
phase and attenuation characteristics  the design of wide band amplifiers
for signals is detailed with tabulated data on various types of
stagger txned circuit whose group delay and attenuation characteristics
are also given
   /
1338
transient analysis of the white cathode follower  the circuit provides
an output impedance and transmits pulses of either polarity with
minimum distortion  transient analysis is made and the effect of
varying circuit parameters is discussed
   /
1339
amplifier compensates for speech level variations  an automatic gain
adjusting amplifier produces constant output without peak clipping
for input variations of forty db
   /
1340
influence of fluctuations of the number of molecules on the frequency
of a molecular beam maser oscillator
   /
1341
a parametric device as a nonreciprocal element  an arrangement is
proposed for combining an up converter with a down converter to obtain
a nonreciprocal phase shifting device  measurements made at a signal
frequency on both a circulator and an isolator are discussed
   /
1342
parametric amplification power control and frequency multiplication
at microwave frequencies using cyclotron frequency devices
   /
1343
an electrostatically focused electron beam parametric amplifier
   /
1344
lower frequency pumping electron beam parametric amplifier
   /
1345
phase sensitive demodulation with interpolation  details are given
of a pulse sampling system for demodulation of a low frequency carrier
errors may be reduced by inter  olation if the general form of the
modulation envelope is known in advance
   /
1346
the calculation of static and dynamic amplitude and frequency distortion
of frequency modulated oscillations with the transmission factor
given in series form  the cases of frequency amplitude and limiting
distortion distortion due to non ideal limiting conditions are investigated
to derive general expressions for the treatment of signal distortion
   /
1347
theory of ultrasonic attenuation in metals and magneto acoustic oscillations
   /
1348
the possible role of the electrical double layer in the contact of
solids and in adhesion phenomena  calculations are made of the surface
charge density and the component of adhesive force for the case of
a  contact between a metal and a semiconductor film and b  a semiconductor
film between two metals
   /
1349
evidence for a configurational e  m  f  in a conducting medium  by
analogy with hydrodynamic effects an is expected to be associated
with a current constriction  experimental evidence for such an effect
is given
   /
1350
theory of superconducting contacts  a generalization of the bardeen
cooper schrieffer theory of superconductivity for the case of a position
dependent energy gap and application to several problems involving
supercondu  ting contacts
   /
1351
diagrams representing states of operation of a general theopocouple
for a wide range of possible thermocouples the operating characteristics
depend on the current and the junction temperatures as an example
the calculation of a cooling region of a diagram for a general couple
is given
   /
1352
pre breakdown phenomena in uniform fields  observations were made
of pre breakdown phenomena in uniform field gaps under ambient atmospheric
conditions and measured irradiation intensities in which current
and light pulses were recorded  from measurements of the current
pulse duration a value for the mobility of positive ions was obtained
at field strengths approaching the breakdown value
   /
1353
some sparkover phenomena with enclosed gaps  breakdown characteristics
of an unventilated and nonirradiated uniform gap are examined and
compared with those obtained uneer a variety of conditions of venti
ation
   /
1354
experimental determination of the individual secondary ionization
coefficients in hydrogen and their dependence on cathode work function
   /
1355
the space charge retardation of electron avalanches  the electric
field generated by the positive and negative space charge of a single
electron avalanche moving in a homogeneous electric field is calculated
a growth formula is derived which differs from the townsend formula
good agreement is obtained between the theoretical results and statistical
data given by other authors
   /
1356
negative current voltage characteristics in hydrogen at high pressure
using plane parallel electrodes  measurements of the characteristics
are described and studied theoretically
   /
1357
comments on necessary and sufficient trajectory conditions for dense
electron beams
   /
1358
high voltage electron extraction frov an arc discharge plasma  a
method is described for obtaining stable electron beams of current
densities using stable electron beams of current densities using
a magnetically confined mercury pool
   /
1359
shift of an electron interference pattern by enclosed magnetic flfx
experiments to confirm the shift are described and the results discussed
   /
1360
the propagation of oscillations in electron beams with uncompensated
space charge  mathematical treatment of an electron cloud rotating
in a uniform magnetic field
   /
1361
theory of longitudinal oscillations of an electrons ion beam  generalization
of results of earlier analysis to the case of arbitrary deformation
of the beam
   /
1362
a paraxial formulation of the equations for space charge flow in
a magnetic field
   /
1363
stability of uniform plasmas with respect to longitudinal oscillations
   /
1364
excitation of waves in plasma  mathematical analysis of plasma excitation
by external currents based on two component plasma theory applicable
to wave excitation at any frequency
   /
1365
statistical mechanical theory of ferromagnetism  high density behaviour
the partition function of the ising model of ferromagnetism is examined
in the limit of high density
   /
1366
surface magnetostatic modes and surface spin waves  the general existence
of surface wave modes in the frequency region above the spin wave
band is shown
   /
1367
on the propagation of a discontinuous electromagnetic wave  a treatment
of a variant of sommerfields problem in which the oscillating dipole
is replaced by a dipole whose moment jumps form zero to one  a solution
for the general case is given in torms of complete elliptic integrals
   /
1368
electromagnetic waves in gravitational fields  ssudy of the scattering
of plane e  m  waves by the gravitational field of an isolated physical
system
   /
1369
boundary layer problems in diffraction theory
   /
1370
planar problem of diffraction of electromagnetic waves by an ideally
conducting strip of finite width  an application of the method of
solution proposed earlier to the case of small values ts the wave
number and the half width of the strip
   /
1371
distribution of current densities on the edges oo an ideally conducting
rectangular wedge placed in the field of a plane electromagnetic
wave  simplified formulae for calculating current densities are derived
which in their final form contain only well known tabulated functions
   /
1372
high frequency diffraction of plane waves by an infinite slit parts
one and two
   /
1373
on the plane weve extinction cross section of an obstacle  the relation
between the extinction cross section of an obstacle which both absorbs
and scatters power and the amplitude and phase of a scattered time
harmonic plane wave is proved using an explicit representation of
the scattered field  the result is valid for a plane wave with arbitrary
elliptic polarization
   /
1374
electromagnetic waves in a plasma located in a magnetic field  mathematical
analysis for the case of a cylindrical plasma rod located in
an uniform external field and isolated from the metallic walls of
a waveguide  a dispersion equation is derived and the e m field configuration
is determined  it is shown that e m waves can be propagated
in the system at frequencies significantly lower than the langmuir
and larmor frequencies
   /
1375
the absorption coefficient of a plasma at radio frequencies
   /
1376
passage effect in paramagnetic resonance experiments  paramagnetic
resonance signals under various experimental conditions are classified
theoretically and some experimental checks carried out
   /
1377
study of damping by coherent radiation in nuclear magnetic resonance
the general equations derived are applied to a calculation of the
range of oscillation and frequency pulling in a maser type oscillator
   /
1378
influence of fluctuations of the number of molecules of the frequency
of a molecular beam maser oscillator
   /
1379
charged particle orbits in varying magnetic fields  a magnetic field
with time variation but with azimuthal symmetry about an axis is
considered  the movement of the charged particle is found by considering
it to move nearly in a circle about a guiding centre whose motion
can also be calculated
   /
1380
drift of a charged particle in a magnetic field of constant gradient
   /
1381
giant fluctuations in a degenerate fermi gas  arguments are presented
that for sufficientsy weak intoractions the ground states in two
or more dimensions are the familiar plane wave states
   /
1382
electronics probes nature  a general review of ppesent investigations
into space our atmosphere the earth the oceans and living matter
the instrumentation of satellites and probes successfully launched
by the united states
   /
1383
measurement of the neutron flux in space  the experimentally determined
count rate agrees well with that calculated from multigroup diffusion
theory if allowance is made for a background flux
   /
1384
the synthesis of large radio telescopes
   /
1385
the spectrum of the galactic radio emission
   /
1386
an experimental investigation of the effects of confusion in a survey
of localized radio sources  surveys of sources have been made using
total power equipment and an interferometer the results are compared
   /
1387
radio emission from the gygnus loop  good positional agreement has
been obtained between several of the radio and optical features but
an intense extended source lying south of the centre of the loop
is not correlated with any outstanding optical feature
   /
1388
a spectral analysis of the radio sources in cygnus x  the results
support the conclusions of other workers showing that the emission
is from optically thin regions except for the strongest source in
the region tie source which was found to have a nonthermal component
   /
1389
the ionosphere of jupiter  an approximate analysis based on chapman
theory suggests that jupiter may possess an ionosphere of critical
frequency existing a few hundred kilometres above the visible clouds
   /
1390
radio emission from jupiter  report on measurements made by the four
element interferometer at cambridge of the relation between flux
density and the diameter of the jupiter  comparison is made with
flux density observations of other authors
   /
1391
the planning and results of the program of observations of the department
for ionospheric research and radio astronomy of the p  t  t  radio
observations of the sun made during the recent perid of maximum solar
activity at the observatories are discussed
   /
1392
solar radio bursts of spectral sype two  an analysis of sixty spectral
type two bursts is used to review the properties of such bursts
in addition to features already well recongnized a herringbone structure
is described  statistical methods are used to study the association
of type two bursts with solar flares and geomagnetic storms
   /
1393
location of the sources of solar bursts  an improved method of observing
positions is described  from correlations with optical data the radial
distances of the radio sources from the centre of the sun have been
deduced
   /
1394
an association between solar radio bursts at metre and centimetre
wavelengths  it appears that type three events which coincide with
cm bursts are frequently followed by a wide band emission termed
type v  mechanisms for generation the cm and type v radiation are
considered
   /
1395
an investigation of the speed of the solar disturbances responsible
for type three radio bursts  simultaneous directional observations
at a number of frequencies between forty and seventy ms  s are described
the results support the hypothesis that type three bursts are
due to plasma oscillations excited in the coronal gas
   /
1396
solar radio events and geomagnetic storms  an attempt is made to
identify solar r  f  bursts of importance three plus with subsequent
sudden commencements of geomagnetic storms for the period april
   /
1397
solar radio emission of spectral type four and its association with
geomagnetic storms  a study of spectral records has been used to
distinguish between type one and sype four storms  the association
of type four storms with lvlar flares and geomagnetic storms is described
   /
1398
the eta carinae nebula and centaurus part two physical discussion
of eta carinae nebula  the temperature density and mass of the object
are inferred from observations of august and other radio data
   /
1399
the extended component of centaurus a
   /
1400
physical state of outer atmosphere and the origin of radiation belts
the trapping of high energy particles is explained by the interaction
of hot plasmas with the geomagnetic field
   /
1401
cosmic ray storms and lvlar radio outbursts  an analysis has been made
of type four r  f  bursts  results suggest that a large corpuscular
cloud with an associated strong magnetic field is emitted simultaneously
with the r  f  burst  the cloud has a small core and when this core
covers the earth cosmic ray and magnetic storms occur
   /
1402
a theory of radar scattering by the moon  a detailed discussion of
available experimental evidence leads to the theory that the scattering
is composed of a number of individual returns from twenth thirty
single scattering areas with those nearest to the earth providing
a specular return information about the material of which this area
is composed can then be obtained
   /
1403
radio elho observations of the geminid meteor stream
   /
1404
on the current system of solar flare effects  the current system
associated with large solar flares is symmetric about the magnetic
equator  it is shown that the current must flow in a region where
electron decay is due to attachment
   /
1405
coupling of the solar wind and the exosphere  possible physical processes
at the geomagnetic boundary are considered in order to resolve
the different estimates of its position obtained from rocket magnetometer
experiments and from the study of cometary tails of type one
   /
1406
interaction of the solar plasma with the earths magnetic field  cal
ulation of the reshaping and termination of the earths magnetic field
by the solar flux of protons and electrons
   /
1407
the geomagnetic field in space ring currents and auroral isechasms
the relations between positions of maximum auroral frequency and
the geomagnons of maximum auroral frequency and the geomagnetic field
lines were studied by using a spherical harmonic representation of
the field
   /
1408
steady component of the interplanetary magnetic field pioneer v
satellite magnetometer measurements suggest the existence of a galactic
interstellar field which is uniform over the solar system
   /
1409
on the magnetic damping of rotation of artificial satellites of the
earth  previous theoretical work is criticized and suggestions are
made for removing some of the analytical limitations
   /
1410
some simple formulas for latitude effects and lifetimes of satellites
empirical equations are presented and their validity checked by considering
the air drag expected
   /
1411
new petred of solution for unretarded satellite orbits  an axially
symmetric solution of laplaces equation in oblate spheroidal coordinates
is found which may be used as the gravitational potential about an
oblate planet  this potential which makes the hamilton jacobi equation
for a satellite orbit separable has an expansion in zonal harmonics
in which the amplitudes of the zeroth and second harmonics can be
adjusted to agree exactly with the values for any axially symmetric
planet and a fourth harmonic which then agrees approximately with
the latest value for that of the earth
   /
1412
the sudden discontinuity in the orbital period of sputnik four satellite
   /
1413
ionospheric information from satellite signals  results of observations
made over a two year period of the fading rate of satellite signals
are briefly described and compared with ionization profiles for the
same poriod  the fading rate changed abruptly during september form
winter to summer values within two days  this effect was preceded
by a change in the direction of travelling disturbances
   /
1414
the determination of ionospheric electron content by observation
of faraday fading  fading was observed on satellite signals  derived
electron densities agreed with those deduced form vertical incidence
soundings up to the maximum of the f layer
   /
1415
the use of geostationary satellites for the study of ionospheric
electron content and ionospheric radio wave propagation  a proposed
experiment for measuring the total electron content of the ionosphere
and for propagation studies
   /
1416
an analysis of radiosonde effects on the measured frequency of occurrence
of ducting layers
   /
1417
artificial electron clouds part six low altitude study release of
cesium  the electron clouds were detected by radar at several frequencies
and the measured duration was in reasonable agreement with theory
   /
1418
on the determination of the true height of ionization at high latitudes
the matrix metred of bubben for determining true height electron
density profiles form ionograms is modified to allow the use of the
third magneto ionic z component when the ordinary component is unsuitable
   /
1419
the general methods of the station lindau harz ffr the determination
of the true electron density distribution in the ionrsphere  three
methods assuming longitudinal propagation for the extraordinary ray
and two correction methods for the reduction of the ordinary and
extraordinary ray traces  these two metrods are used to determine
the corrections to be applied to the profile of the reference layer
previously obtained by a comparison method to obtain the true profile
   /
1420
performance of an r  f  impedance probe in the ionosphere  new values
of electron density agree with those from other techniques  earlier
data were found to be to be too low owing to distortion of the environment
by the potentials applied to the probe
   /
1421
diurnal variation of the electron distribution in the ionospheric
e layer
   /
1422
some aspects of sporadic e at midlatitudes  it is found that e ionization
often occurs where the trough and crest slope lines of f layer
irregularities meet the e layer level  this suggests that e and spread
f are caused by the same mechanism  a possible structure of e is
pro osed and its relation to the occurrence of the green line of
the airglow is discussed
   /
1423
the equatorial f region of the ionosphere  critical frequencies in
the f region at panama and chimbote are negatively correlated in
the afternoon  this phenomenon together with the diurnal variation
in height thickness and electron density of the equatorial f region
is consistent with the theory of ionization transportation from the
equator to the subtromics suggested by martyn
   /
1424
electron distribution in the f layer of the ionosphere over haringhata
calcutta on quiet and disturbed days  electron density height profiles
have been reduced and compared with similar results for sloxgh and
maui  it was found that the scale height in the model given by ratcliffe
et al
   /
1425
the geographical distribution of ionization in the f layer  existing
data are not sufficient to prove conclusively that the equatorial
trough in f exists in the western hemisphere at certain times of
the year
   /
1426
equilibrium electron distributions in the ionospheric f layer  the
equilibrium equation has been solved numerically for the daytime
f region using isothermal and actual ionospheric models  at the f
layer peak the effects of production loss and plasma diffusion are
approximately equal  below the peak diffusion is unimportant but
becomes dominant above it where the electron distribution takes on
an exponential form
   /
1427
the temperature of the f region of the upper atmosphere as deduced
from ionospheric measurements  chapmans theory has been extended
to include the variation of an attachment like loss coefficient with
height in the f region  application of the theory to data obtained
in the form of kelso distributions shows that the region may be regarded
as isothermal
   /
1428
triple splitting with the f region of the ionosphere at high and
mid latitudes  occurrence of the third z ray component is investigated
at various times of day season and sunspot cycle and at different
magnetic inclinations  a connection with the occurrence of spread
f is suggested
   /
1429
possibility of detecting ionospheric drifts from the occurrence of
spread f echoes at low latitudes  observations of the times of occurrence
of spread f echoes have been made at four stations in peru  results
suggest that ionospheric drifts may flay an important part in the
occurrence of spread f echoes at low latitudes
   /
1430
diurnal variations of density and scale height in the upper atmosphere
the radio echo meteor technique has been used to calculate the neutral
particle densities  diurnal oscillations in density are found with
amplitudes  semidiurnal oscillations are also present having approximately
half these amplitudes
   /
1431
photochemical rates in the equatorial f region from the eclipse
it is deduced tiat temperature changes and transport of electrons
were probably negligible during the eclipse  formulae are given for
the rate of photoionization and the linear recombination coefficient
as a function of height and the total rate of absorption of energy
in the f region is deduced
   /
1432
geophysical effects associated with the high altitude nuclear explosion
collected papers on observations of atmospheric and gelmageetic disturbances
associated with the explosions at johnston island on august
   /
1433
hydromagnetic wave propagation in the ionosphere  general equations
are obtained governing hydromagnetic wave propagation assuming approximations
valid for the ionosphere  for wave periods of less than one
h the equations are very similar to those for the propagation of
radio waves in the ionosphere
   /
1434
on the ionospheric heating by hydromagnetic waves connected with
geomagnetic micropulsations  heat production and consequent temperature
increase are negligible
   /
1435
the size of the moving irregularities in the f region and the spread
angle of the radio waves scattered from them  analysis of fading
patterns obtained by a three receiver method discloses an average
length of irregularity
   /
1436
incoherency of pulse echoes and the measurement of ionospheric absorption
incoherently scattered energy gives rise to errors in absorption
measured by the pulse echo method  calculations of the magnitude
of the error are confirmed by experimental observations
   /
1437
polar ionospheric disturbances associated with a severe magnetic
storm  a detailed investigation is made of the storm on october using
world wide geomagnetic and ionospheric data
   /
1438
morphology of the ionospheric f disturbances in the polar region
   /
1439
anomalous f variations in the antarctic  the daytime minimum in the
f layer critical frequency which is often observed in the antarctic
is explained on the basis of a vertical shear in the horizontal wind
and the resulting movement of charged particles in the presence of
the earths magnetic field
   /
1440
models of the atmospheric radio refractive index
   /
1441
lightning counter and results obtained in sweden during the thunderstorm
period  tests performed on a pierce golde cold triode counter show
that it records both strokes to earth and discharges between clouds
   /
1442
the electrical structure of thunderstorms  a model representing the
structure of thunderstorm electricity has been developed from an
analysis of simultaneous observations of thunderstorms in the vicinity
of kyoto japan
   /
1443
the scattering of thirty six mc  s radio waves by weak auroral ionization
   /
1444
the distribution of radio aurora in central canada  the results of
five mlnths observations using bistatic v  h  f  radio systems are
described  night time and daytime events are detected and their distributions
compared
   /
1445
association between aurorae and very low frequency hiss observed
at byrd station antarctica
   /
1446
observations of whistlers and chorus at the south pole
   /
1447
a study of chorus observed at australian stations  the variation
of occurrence with geomagnetic latitude time of day and k index has
been studied  possible movements of the generating region are deduced
   /
1448
the current jet hypothesis of whistler generation  the suggested
mechanism involves the interaction between an electron stream travelling
upwards as the result of a lightning discharge and the e  m  radiation
from a second discharge
   /
1449
some comments on the penetration of whistlers through ionospheric
layers  ionospheric irregularities smaller than the whistler wavelength
may prevent penetration of the layer and lead to the cessation of
whistlers at certain times
   /
1450
hyperbolic direction finding with sferics of transatlantic origin
description of a system for locating thunderstorms by measurement
of the time difference of arrival of atmospherics at several stations
position lines for sources in the atlantic were established from
a network in the u  s  and compared with fixes from a u  k  d  f
network
   /
1451
some measurements of atmospheric noise levels at low and very low
frequencies in canada  values are expressed in terms of mean noise
power and are compared with predictions  effects of location of source
and propagation conditions are discussed  amplitude frequency curves
are studied in detail
   /
1452
v  l  f  attenuation for east west and west east daytime propagation
using atmospherics
   /
1453
static inverter delivers regulated three phase power  silicon controlled
rectifiers in conjunction with magnetic amplifiers are used
   /
1454
the characteristics and protection of semiconductor rectifiers
   /
1455
design of static relays for signalling and control  the advantages
of static relays and the replacement of mechanical relays by semiconductor
devices are discussed  circuit diagrams are given
   /
1456
analogue multiplication using time as one variable  if one analogue
quantity appears as a time interval accurate electronic multiplication
is simplified  transistor circuits giving products proportional to
average or peak output voltage are described
   /
1457
the minimization of the effect of drift in d c analogue computers
   /
1458
the elliott sheffer stroke static switching system  a system is described
in which interconnections between a number of logic elements all
of the same type the sheffer stroke permit any logical configuration
or switching sequence
   /
1459
all purpose computer circuits automatically connected to solve specific
problems  different connections may be made automatically using a
photo conductor matrix which may also be used to detect and replace
faulty parts
   /
1460
the resistance network a simple and accurate aid to the solution
of potential problems  a method applicable to two dimensional problems
and to three dimensional problems where there is rotational symmetry
is described  in either case laplaces equation for given boundary
conditions reduces to a differential equation involving two independent
variables only
   /
1461
theory of a monolithic null device and some novel circuits  a semiconductor
structure which behaves as a twin t filter network is described
and applied to a tuned amplifier oscillator and transducer
   /
1462
the miniaturization of resistors  review of available types of carbon
and metal film resistors resistance materials and resistor cooling
systems with tabulated results of climatic tests on film type resistors
   /
1463
semiconducting diamonds as thermistors  the performance and construction
of diamond thermistors are described which have high thermal conductivity
and resistance to corrosion
   /
1464
conducting hard rubber and its use as composition resistor
   /
1465
thin film cryotrons  discussion of the characteristics of evaporated
superconductive films as applied to cryotrons and details of a thin
film cryotron made by vacuum deposition which is much smaller than
the wire wound component  the performance of this cryotron is given
and it is applied to flip flop circuits  finally its use in ring
oscillators is analysed by two different methods
   /
1466
piezoelectric voltage transformers  possible modes of operation are
considered and the design and performance of a ceramic transformer
with respect to one of these modes is examined  the advanect to one
of these modes examined  the advantages and possible applications
of such devices are discussed
   /
1467
irreversible thermodynamics of a nonlinear rc system  the solution
is compared with those of other investigators
   /
1468
i r e standards on circuits definitions of terms for linear signal
flow graphs
   /
1469
ire standards on circuits definitions of terms for linear passive
reciprocal time invariant networks
   /
1470
partial equivalence with reference to a theorem of cocci cauer  the
equivalence of two terminal networks containing r c and l elements
is discussed
   /
1471
on network synthesis with negative resistance  a procedure is outlined
which results in realizable networks with lossy elements arranged
in foster terms
   /
1472
solution of ladder networks containing nonlinear resistances  a graphical
method of solving network problems involving nonlinear and or
negative resistances is described  such networks have been used for
the solution of nonlinear differential equations
   /
1473
design of networks with prescribed delay and amplitude characteristics
a general analytic method is described for designing reactive quadripoles
with specified group delay characteristics  means of equalizing
attenuation without affecting the delay are discussed
   /
1474
image parameter theory for mechanical quadripoles in compressional
or torsional oscillation  the equivalence of the parameters of a
mechanical system transmitting compressional or torsional oscillations
and the parameters of an electrical transmission line is established
the design of mechanical filters is described and design formulae
with response characteristics are given for the basic filter sections
   /
1475
special band pass half sections  the design of crystal filters of
branch network type is described
   /
1476
a decimal attenuator  a network combining the properties of a conventional
voltage or current divider with those of a constant resistance
attenuator
   /
1477
a multiple isolated input metoork with common output  design equations
are developed for the general case of n isolated inputs with a common
output  measurements made on two input and three input units are
given
   /
1478
frequency of the three phase rc coupled oscillator part two inductive
anode load resistance
   /
1479
the optimum design of rc valve oscillators  nonlinear distortion
is analysed and optimum operating conditions are determined by means
of an analytical method using nonlinear co efficients
   /
1480
shock excitation of a radio frequency power circuit by means of a
saturable core reactor
   /
1481
circuit applications of field effect transistors  applications of
photosensitive cds transistors in sawtooth generators amplifiers
and phase shift oscillators are described
   /
1482
microwave detection and harmonic generation by langmuir type probes
in plasmas  rectification effects are obtained with co d cathode
d c discharges in he or ne
   /
1483
a travelling wave harmonic generator  a scheme is outlined in which
a series of delay line outputs displaced in phase relative to one
another are combined to deliver pulsed power at a predetermined harmonic
of the input frequency
   /
1484
systems using transistors and transductors  amplifier modulator and
switching systems are described in which transistors and transductors
are combined
   /
1485
high input impedance transistor circuits
   /
1486
linear phase transistor amplifier  the design of a simple shunt compensated
linear phase amplifier is described
   /
1487
a low drift transistor chopper type d c amplifier with high gain
and large dynamic range
   /
1488
narrow band amplification with transistors  the design formulae for
tuned circuit coupling of amplifier stages with resistance and with
reactance matching are considered and design curves are given for
optimum circuit conditions
   /
1489
a nonlinear effect in transistor amplifiers with feedback
   /
1490
inversion by fast passage in a multilevel spin system  some measurements
of adiabatic fast passage in a multilevel electron spin system are
described with particular reference to a recent proposal for a staircase
maser
   /
1491
optimum noise and gain bandwidth performance for a practical one
port parametric amplifier  analysis shows that the conditions necessary
for minimum noise temperature are compatible with those necessary
for maximum gain bandwidth product if the diode has a high self resonance
frequency  there is a characteristic figure of merit for the diode
and an optimum pump frequency  a series of design curves is given
   /
1492
symmetrical matrix analysis of parametric amplifiers and converters
expressions are derived for gain bandwidth and noise figure and by
regarding the matrix as a nodal admittance array an equivalent conductance
c rcuit is constructed  it is shown that for low no se figure
and wide bandwidth the idler frequency should be much higher than
the signal frequency
   /
1493
a transmission matrix analysis of the cavity parametric amplifier
   /
1494
interaction of two microwave signals in a ferroelectric material
   /
1495
on stabilizing the gain of varactor amplifiers  use of the varactor
d c to comtrol pump level improved the gain stability
   /
1496
an x band parametric amplifier using a silver bonded diode  a wafer
type construction is used for the silver bonded diode
   /
1497
parametric amplifier theory for plasmas and electron beams  a theory
is given for a parametric amplifier which uses a gas discharge plasma
an experimental amplifier is described
   /
1498
the theory of magnetic ring modulators  the equivalent circuit of
the magnetic ring modulator is derived for idealized b h characteristics
and the design of a modulator circuit is given
   /
1499
a new use of the junction transistor as a pulse width modulator
the base pulse current is modulated in a common emitter configuration
   /
1500
fluctuations from the nonequilibrium steady state  a macroscopic
treatment of noise is presented using markovian and stationary assumptions
   /
1501
the electrostatic energy of a space charge
   /
1502
microwave measurements of dielectric absorption in dilute solutions
   /
1503
acceleration of charged particles in travelling or stand ng electromagnetic
waves  the average lorentz force acting on a charged particle
in an e m field depends on the resonance properties of the motion
of the particles and on the spread in their transverse momentum
conditions under which continuous acceleration can be achieved by
spatial variation of the particle oscillation parameters are discussed
   /
1504
determination of the effective scattering mechanism parameter of
electron transport theory  fermilevel energy effective scattering
mechanism parameter effective mass and relaxation time can be obtained
from the magneto seebeck effect for corbino disk geometry when combined
with other transport measurements
   /
1505
an analogue solution for the static london equations of superconductivity
measurements of field distributions in the space around the normal
conductors of a growing exponential function generator provide useful
cryogen c circuit design data
   /
1506
gauge invariant formulation of the bardeen cooper schrieffer theory
of superconductivity
   /
1507
an analogy between the effects of fluctuating electric fields and
steady magnetic fields in isotropic conductors when a universal relaxation
time cannot be defined
   /
1508
propagation of perturbations in a one dimensional two beam electron
flow  using a difference kernel integral equation method a solution
is obtained for drift in two beam flow in the presence of a transverse
electric field
   /
1509
three dimensional space charge flow  gives theory and experimental
results for stationary beams allowing for e s interaction between
the particles
   /
1510
equilibrium conditions for electron beams  the conditions are determined
for a beam in which the density of secondary particles is much greater
than that of primary electrons
   /
1511
nonlinear behaviour of a modulated electron beam in the presence
of a velocity distribution  the harmonic currents in an electron
beam with a velocity distribution can be evaluated by a procedure
based on the boltzmann equation
   /
1512
the electrokinetic power theorem  the electrokinetic power theorem
is shown to be valid also for arbitrary electron velocities relativistic
conditions if certain definitions are adopted
   /
1513
on the properties of the electron beam in the presence of an axial
magnetic field of arbitrary strength  a study of the effect of an
axial magnetic field on the propagation of waves in an idealized
electron beam using small signal theory and neglecting collisional
effects  the possibility of angular asymmetric excitation is considered
and special attention is paid to the influence of the a c drift lorentz
terms and of the relativistic corrections in the derived equations
   /
1514
the electromagnetic interaction between two crossing electron streams
parts one and two  the interaction between two infinitely extended
velocity modulated streams has been studied  in part one where beam
velocities common to microwave valves are considered the lorentz
term in the equation of motion has been omitted  it is introduced
in part two for higher beam velocities  the distribution of ions
formed by attachment of electrons moving in a steady state of motion
through a gas  the distribution of ions formed by attachment of electrons
diffusing through a gas is solved exactly and the results are
compared with an approximate calculation given earlier by huxley
   /
1515
ionic conductivity of highly ionized plasmas  values of plasma resistivity
as measured by a current entering and leaving the plasma and
the flow velocity in hydrogen at various gas pressures are given
together with a discussion of the theoretical aspects of the problem
   /
1516
propagation and production of electromagnetic waves in a plasma
a general review of nonthermal mechanisms for the emission of e m
waves in a plasma
   /
1517
linearized theory of plasma oscillations
   /
1518
microwave conductivity of a plasma in a magnetic field  the boltzmann
equation for electrons in a uniform isothermal plasma is solved
the microwave conductivity is simply related to certain coefficients
of the solution
   /
1519
the transport phenomena in cylindrical discharges in the presence
of magnetic fields
   /
1520
microwave detection and harmonic generation by langmuir type probes
in plasmas
   /
1521
waves in a conducting sheet situated in a strong magnetic field
the hydromagnetic approximation is applied to the elementary linear
theory of transverse waves in a thin uniform plane conducting sheet
in which the inertia is provided by the sheet and the restoring forces
by strong vacuum magnetic fields on either side of the sheet  the
dispersion relation and damping are obtained  the waves should be
observable in the laboratory
   /
1522
nuclear spin lattice relaxation caused by paramagnetic impurities
   /
1523
on the uniqueness theorem for electromagnetic fields  resonant modes
and mixed boundary condition in the steady state are considered
   /
1524
impulse excitation of a conducting medium
   /
1525
electromagnetic transients in conducting media
   /
1526
a reciprocity theorem for the electromagnetic field scattered by
an obstacle
   /
1527
propagation at oblique incidence over cylindrical obstacles  the
effect of oblique incidence can be considered as a change in the
effective radius of curvature of the diffracting obstacle
   /
1528
diffraction by smooth conical obstacles  expressions obtained earlier
are generalized to oblique incidence and conical surfaces  the derivation
is based on a generalized concept of the greens function and on
the use of corrective factors  results are compared with scale model
measurement
   /
1529
a new method of solving the problem of the diffraction of electromagnetic
waves by a thin conducing disk  the problem is reduced to the
determination of two functions each of which satisfies a fredholm
integral equation which can be solved by numerical methods  a simple
formula for the scattering coefficient is derived
   /
1530
the planar problem of the diffraction of electromagnetic waves by
two ideally conducting strips of finite width located one below the
other  mathematical analysis based on the method of successive approximations
using special approximation formulae
   /
1531
reciprocity and scattering by certain rough surfaces
   /
1532
backscattering from a finite cone
   /
1533
the interaction between an obliquely incident plane electromagnetic
wave and an electron beam parts two and three  the work described
earlier is extended in part two to include the case where there is
no static magnetic field present  in part three results obtained
are analysed for possible resonance conditions to provide a more
direct physical interpretation of the formulae derived
   /
1534
depth of penetration as a measure of reflectivity of thin conductive
films
   /
1535
electromagnetic theory of d c effects in ferromagnetic resonance
deals with propagation through thin sheets of ferromagnetic conductors
   /
1536
paramagnetic resonance along the direction of the polarizing field
a radio frequency susceptibility along the polarizing field is observed
when the electron spin resonance of dpph is partly saturated at microwave
frequency  the variations of the real and imaginary parts as a
function of the radio frequency have been studied  theoretical calculations
are in good agreement with experiment  in some cases a negative
susceptibility appears which has been used in a molecular amplifier
experiment
   /
1537
space research  slightly abridged text of a survey paper prepared
by the national aeronautics and space administration washington on
space research techniques and recent experimental data with a summary
of a discussion by experts from n a t o countries at a meeting at
aachen
   /
1538
a new limit to the galactic magnetic field set by measurements of
the zeeman splitting of the hydrogen line  results give no positive
evidence for a magnetic field in any of the clouds studied
   /
1539
an attempt to detect the galactic magnetic field field using zeeman
splitting of the hydrogen line
   /
1540
the possibili  y of detecting a gravitational red shift in twenty
one cm radiation form the galaxy  there seems to be little possibility
of recognizing a gravitational red shift as suggested by landovitz
and marshall until the detailed structure and motions have been established
more definitely
   /
1541
on the spectra of radio sources  expressions are derived which suggest
that there should be a progressive increase in the slope of the frequency
spectrum of the flux density for more distant sources than cygnus
a
   /
1542
relation between the solar emission of cosmic rays and type four
bursts
   /
1543
influence of hall effect on the induced current in the earth owing
to magnetic disturbances  earlier theory of the origin of geomagnetism
is modified by allowing for hall effect which accelerates the build
up of induced currents in the earths crust
   /
1544
some characteristics of geomagnetic micropulsations
   /
1545
measured electrical properties of snow and glacial ice  in general
the conductivity of snow and glacial ice is much higher than that
of pure ice
   /
1546
rocket and satellite instrumentation
   /
1547
the radiation from artificial earth satellites  the various factors
affecting e m wave propagation from satellites are reviewed and discussed
with reference to results obtained by radio observations and c
r d f equipment
   /
1548
satellite perturbations from extra terrestrial gravitation and radiation
pressure  the equations of motion of a satellite are written in terms
of displacement components relative to the unperturbed elliptic orbit
a moving system of co ordinates is used which consists of an orthogonal
triad whose origin is always located at the nominal satellite position
on the elliptic orbit
   /
1549
fading of satellite transmissions and ionospheric irregularities
the orientation of the irregularities is suggested as an explanation
of the observations of kent
   /
1550
earth satellite observations and the upper atmosphere temperature
inversion in the f layer  the suggested wiggle in the curve for logarithmic
density has been derived exactly from satellite observations
   /
1551
earth satellite observations and the upper atmosphere diurnal and
seasonal density variations in the upper atmosphere
   /
1552
the use of polarization fading of satellite signals to study the
electron content and irregularities in the ionosphere  a ray tracing
program and a model ionosphere have been used to evaluate electron
content  refraction and where necessary path splitting are taken
into account
   /
1553
second order faraday rotation formulas
   /
1554
determination of satellite orbits from radar data  procedural stages
in an optimum computer routine using two orbital points and the transit
time between them incorporate a differential correction based on
short range data
   /
1555
power spectra of temperature humidity and refractive index from aircraft
and tethered balloon measurements
   /
1556
a relation between ionospheric drifts and atmospheric dynamo current
systems  geomagnetic data suggest that the focus of the atmospheric
dynamo current system moves from north to south of sydney as solar
activity increases  this would explain the reversal in the direction
of ionospheric drifts at sydney during recent years
   /
1557
effects of vertical diffusion of electrons near the magnetic equator
the effects are shown to account for the major features of the geomagnetic
anomaly discussed by croom et al  the anomaly is an excess of
ionization due to diffusion away from the equator rather than a deficiency
of ionization due to diffusion away from the equator rather than
a deficiency of ionization at the equator
   /
1558
anisotropic field aligned ionization irregularities in the ionosphere
near the magnetic equator  equatorial scatter echoes were measured
at huancayo during the i g y
   /
1559
experimental relations between ionospheric true height group height
and phase height
   /
1560
the determination of the true height of maximum ionization by the
ten point method
   /
1561
true height and thickness of the ionospheric e layer  a method proposed
by schmerling has been applied to calculations of the true height
and thickness of the e layer  results given for a single daytime
period show irregularities in the fine structure of the layer
   /
1562
nonseasonal variation in the e layer ionization  appreciably greater
ionization is found in december than in june  a relation to the van
allen radiation belts is tentatively suggested
   /
1563
the world wide semi annual cycle in the e layer of the ionosphere
the monthly mean values of the e layer character figure for eight
stations in the northern and southern hemispheres have been calculated
   /
1564
theory of spread f based on aspect sensitive back scattered echoes
a large class of spread f echoes in equatorial regions may be explained
by assuming that back scatter echoes are aspect sensitive with regard
to irregularities aligned along the earths magnetic field
   /
1565
equatorial spread f and f layer heights  extension of earlier work
to include a study of the high correlation between the rise in height
of the f layer just after local sunset and the subsequent occurrence
of spread f
   /
1566
ionospheric refraction in radio astronomy  expressions are derived
for the apparent displacements of cosmic radio sources at transit
resulting from ionospheric refraction  the theory includes the effects
of horizontal electron density gradients which often outweigh those
due to a spherically symmetrical ionosphere  the relation of ionospheric
refraction to the total thickness and the total electron content
in a vertical column are discussed
   /
1567
scintillation spread f and trans equatorial scatter  both radio star
scintillation and spread f show little dependence on magnetic activity
during sunspot minimum at sunspot maximum they are strongly negatively
correlated whilst transequatorial scatter is positively correlated
with magnetic activity
   /
1568
short term differences in the behaviour of two daily indices of solar
activity during the i g y
   /
1569
sunrise and eclipse effects on the ionosphere at brisbane
   /
1570
dynamic characteristics of the ionosphere and their coherency with
the local and planetary magnetic index
   /
1571
geomagnetic field and ionospheric drift  drift measurements at new
delhi do not show the semi diurnal periodicity which would be expected
if the drifts were in the form of lunar or solar tides  some correlation
with the magnetic index k is looked for but is not found except on
disturbed days when the northward velocity of the north south component
increases with increasing k
   /
1572
on the effect of the magnetic field of the earth on winds in the
ionosphere  a theoretical treatment of electrodynamic and hydrodynamic
processes in the ionosphere
   /
1573
ionospheric electrostatic fields and the equatorial electrojet
   /
1574
fading of c w signals as a means of spread f study
   /
1575
a study of two mc s ionospheric absorption measurements at high latitudes
from a study of the data of five stations in canada during the
i g y it is found that a the winter anomaly of noon absorption occurs
at churchill but is absent at resolute bay b the effect of solar
zenith angle as illustrated at the diurnal variation of absorption
decreases with increasing latitude c midnight absorption is a maximum
in the auroral zone but is also high over the polar cap
   /
1576
identification of mode in low frequency sweep ionospheric sounding
and interference patterns between overlapping echoes  the echo is
received on a pair of crossed coplanar horizontal dipoles and split
into its two circular components by means of a two channel receiver
the resulting video signals are electrically subtracted and applied
as brilliance modulation to a conventional c r tube where the echo
is displayed as a light or dark trace depending on its sense of rotation
the technique is convenient for observing interference fringes
and these effects are discussed
   /
1577
some magneto ionic phenomena of the arctic e region  unusual phenomena
at thule are described and are attributed to the effects of electron
collisions on radio wave propagation at high latitudes
   /
1578
vertical distribution of radio refractive index in the medium height
of atmosphere  an examination of radiosonde and captive balloon data
from japanese stations indicates an exponential variation for the
lower atmosphere but not for the upper
   /
1579
simultaneous v h f auroral back scatter measurements
   /
1580
some e l f phenomena  electric field fluctuations at frequencies
below one kcs are discussed with reference to e m changes associated
with atmospherics and e s variations in atmospheric electricity
   /
1581
energy fluxes from the cyclotron radiation model of v l f radio emission
further consideration of the cause of dawn chorus
   /
1582
an optimal discrete stochastic process servomechanism  an extension
of mills theorem
   /
1583
the influence of impurities on the strong field effect in selenium
rectifiers  the reverse i v characteristic of se rectifiers depends
chiefly on the purity of the materials used  with pure se the reversal
of the sign of the temperature coefficient is displaced towards lower
temperatures and higher voltages
   /
1584
the design of controlled rectifiers using triode transistors  polyphase
rectifiers are described with switching elements of p n p and n p
n transistors and stability conditions are investigated graphically
   /
1585
highly stable medium voltage direct and alternating voltage sources
part two  addition to earlier review dealing with short term stabilization
by valve circuits or transductors and with the reduction of long
term drift in d c power units
   /
1586
electronic computers and the engineer  an outline of the form and
function of the main units of a digital computer  the basic techniques
of programming are described
   /
1587
the physical realization of an electronic digital computer input
and output  continuation of a series of papers and back references
electromechanical input output equipment is described
   /
1588
universal tape amplifiers for digital data systems  read and write
amplifiers covering a wide range of input characteristics can be
used with both return to zero and non return to zero pulse techniques
at rates up to
   /
1589
designing ultrasonic delay lines  the significant operational characteristics
of delay lines and their influence on design are examined
   /
1590
the minimality of rectifier nets with multiple outputs incompletely
specified
   /
1591
a computer oriented toward spatial problems  a stored program computer
is described which can handle spatial problems by operating directly
on information in planar form without scanning or other methods for
transforming the problem into some other domain
   /
1592
analogue computation  a survey of the principles practice and current
applications of computers together with a tabulated analysis of british
models
   /
1593
new job for an old method capacitor storage used in analogue memory
a delay of for signals of frequency up to with negligible attenuation
and an error of can be obtained by the unit described
   /
1594
fourier analysis by a general purpose electronic analogue computer
a method for use with a high speed differential analyser is described
in which the period of the harmonic function generated by the computer
is kept constant and the period of the arbitrary function made variable
   /
1595
electron gun operates high speed printer  a method of converting
pulse code data from a shaped beam c  r  tube into printed records
on untreated paper at a rate of characters min is described
   /
1596
resistance potentiometers as function generators  the generation
of functions of a single variable by means of resistance potentiometers
is reviewed  see also
   /
1597
end fired memory uses ferrite plates  magnetic flux is induced around
corresponding holes in two adjacent plates and in this way irregularities
in the material from hole to hole do not affect the accuracy
storing and switching systems using plates are described and suitable
transistor drive and regeneration circuits are given
   /
1598
impedance matched or optimum  examples are given of situations where
matched impedance is the ideal condition and of cases in which other
impedance relations prove to be better
   /
1599
through connections for printed wiring  in the process described
a metal eyelet is passed through the printed circuit board staked
and soldered ine one operation
   /
1600
a voltage sensitive switch  the controlled dielectric breakdown of
oxide films has been investigated  a small shock resistant device
requiring no additional power supply has been developed which consists
of an oxide layer between an al base and a ag film  before breakdown
the device has a resistance of at least on switching the resistance
drops to about  some circuit applications are described
   /
1601
solving thermistor problems  the methods of designing circuits incorporating
thermistors are illustrated by giving three particular cases
   /
1602
non linear properties of carbon resistors  a method of determining
the nonlinear characteristics is proposed which is based on the measurement
of harmonics produced when a pure sinusoidal current flows through
the resistor
   /
1603
the versatile vamistor  construction specification and performance
data of a resistor incorporating the best features of wire wound
and carbon types
   /
1604
designing transistor circuits switching statics  the basic switching
properties of junction transistors are examined and examples of single
and multiple switches are given
   /
1605
an electronic transmit receive switch  incoming signals are fed via
the tank circuit to a r  f  pentode which is cut off by grid bias
when the transmitter is on  see also
   /
1606
a temperature sensitive ceramic reactance element  a sintered mixture
of and gives within the range to a nearly linear repeatable capacitance
temperature curve with a change of capacitance  the effects of different
percentages of are examined and applications are mentioned
   /
1607
a voltage variable capacitor  details of a subminiature junction
device with a variable capacitance controllable by bias voltage
are given  applications of the varicap to an f  m  transmitter an
amplifier and a variable filter are described  see also of
   /
1608
response of a capacitance resistance divider to the step function
exponential function and ramp function
   /
1609
a four pole analysis for transistors  an algebraically convenient
analysis for four pole networks is presented based upon determinant
techniques it is applied to transistor circuits and introduces two
new comprehensive parameters for the transistor
   /
1610
additional tables for design of optimum ladder networks  tables for
networks with characteristics given by butterworth tchebycheff and
bessel polynomials are presented they are classified on the basis
of the conductance ratio  see also
   /
1611
estimation of dissipative effects in tchebycheff symmetrical filters
comment on of
   /
1612
low pass rc filter with optimum response  formulae and graphs for
one and two section filters are given
   /
1613
narrow band magnetostrictive filters  filters each with a bandwidth
of are arranged with inputs in series and outputs isolated from one
another to form a bank with a centre frequency of about  design and
construction are described and applications of single resonators
and arrays are considered  temperature effects are reduced by using
cobalt substituted ferrites
   /
1614
a waveguide filter theory  on the basis of the matrix theory used
by hessel et al  formulae are derived giving insertion loss and envelope
delay for multistage filters having as parameters the ratios of the
bandwidth of the stages to the bandwidth of the total filter
   /
1615
wide range rc oscillator  a frequency range exceeding in a single
sweep can be obtained with the tone source described  elements having
continuously distributed series resistance and shunt capacitance
are used which can be made from standard high stability resistors
   /
1616
negatively biased multivibrator  description of a multivibrator which
has its grids returned to a negative bias  it has high frequency
stability and is suitable for use as a variable frequency source
or a source of special wave shapes and can be frequency modulated
the frequency varies linearly with bias voltage
   /
1617
transistor blocking oscillator circuits  circuit characteristics
are examined and methods for varying the output waveform are discussed
   /
1618
increased sensitivity of trigger circuits  in the cathode coupled
monostable multivibrator described the use of a crystal diode in
the feedback loop allows one valve to amplify the trigger pulse before
it is applied to the other valve  the circuit is sensitive to a few
millivolts
   /
1619
latching counters  the causes of low reliability of single pulse
counter chains are examined  a circuit with a multiphase output is
described which has a frequency range from d  c  to and eliminates
spurious pulses reset facilities and general design features including
the use of transistor circuits are discussed
   /
1620
sensitive single channel pulse height analyser  the analyser operates
with input pulses of amplitude and a dead time of about  the stability
over a period of several days is better than
   /
1621
harmonic generation with ideal rectifiers  the harmonic cannot be
generated with an efficiency exceeding  at least of the power converted
to d  c  and harmonics is d  c  dissipation this cannot be reduced
by an arrangement of selective circuits
   /
1622
harmonic generation with nonlinear reactances  a simple theory of
frequency multiplication using nonlinear reactances is derived and
compared withe the results obtained with the nonlinear capacitance
of a ge point contact diode  the theory and the experimental results
are in agreement at low input powers  possible reasons for the discrepancies
at high powers are mentioned
   /
1623
linear amplifier for negative pulses  a two valve amplifier is described
which has a gain of and a rise time of for outputs up to
   /
1624
three valve preamplifier  a description and performance specification
of a circuit with inputs and crystal pickups tape recorder and radio
receiver  simultaneous outputs for tape recording and for a power
amplifier are provided  see also of
   /
1625
broad band amplifier for radar and scatter  the design of a low noise
two stage amplifier and mixer for the range is described  overall
power gain is with noise figures varying from to over the frequency
band
   /
1626
design considerations for direct coupled transistor amplifiers  it
is shown that the maximum obtainable signal drift ratio of an amplifier
is achieved by choosing the optimum source resistance the signal
drift capability of a transistor and the optimum source resistance
are nearly the same for the three configurations common emitter common
collector and common base negative feedback can change the optimum
source resistance and generally degrades the signal drift ratio improved
signal drift ratio can be obtained at reduced emitter currents
   /
1627
circuit designed for high voltage gain from transistors  in the circuit
described a common emitter stage feeds into a modified common collector
stage with low output impedance
   /
1628
transistor audio amplifier  design principles are outlined for using
multiple push pull stages in series  the construction of a amplifier
for battery operation and of a low noise preamplifier is described
   /
1629
public address amplifiers using transistors  the amplifiers work
from or supplies and may be fully driven by a low impedance microphone
   /
1630
a transistor video amplifier having volts output
   /
1631
transistorized if strip design  the performance of tetrodes in grounded
emitter and grounded base circuits is compared  a nine stage if amplifier
using grounded emitter tetrodes is described with transformer
coupling between stages providing for neutralizing and matching
   /
1632
temperature stable transistor circuit based on the half supply voltage
principle  the principle is applied to the design of a transformerless
af output stage and is used in each stage of a six transistor superheterodyne
receiver  see of
   /
1633
masers and related quantum mechanical devices  theoretical aspects
are considered leading to the computation of the dielectric constant
of a gaseous medium in a form which can be directly applied to the
solution of problems in waveguides and cavities
   /
1634
behaviour of a two level solid state maser  it is shown under simplifying
assumptions that when a system of spins is in resonance with the
cavity and when damping effects caused by relaxation phenomena and
cavity losses are not excessive modulation of the cavity power output
is exactly what is to be expected on the basis of a dynamical analysis
see also of
   /
1635
proposed method for tuning a maser cavity  a method is described
for determining the small difference between the cavity resonance
frequency and the frequency of the microwave spectral line
   /
1636
circuit conditions for parametric amplification  it is shown that
signals may be amplified in a circuit which consists exclusively
of passive elements if a nonlinear or time varying reactance is present
the circuit conditions which must be satisfied are established and
the differences between parametric amplifiers and mixers or modulators
are discussed
   /
1637
parametric amplification and frequency mixing inpropagating circuits
an analysis is given of the properties of time varying distributed
reactance in propagating structures which may have positive or negative
phase and group velocities  power at different frequencies may be
converted from one frequency to the others and the amplitudes of
the waves may vary exponentially or periodically depending on the
relation of the frequencies and of the phase constants between the
propagating waves and the variable coupling reactance  applications
to wide band frequency converters frequency channel selectors wide
band amplifiers tunable narrow band amplifiers and oscillators are
described
   /
1638
gain bandwidth and noise characteristics of the variable parameter
amplifier  increased gain is achieved by raising the of the idling
resonant circuit or the amount of variation in the variable coupling
reactance  the bandwidth is inversely proportional to and to the
voltage gain and directly proportional to the ratio of idling resonance
frequency to amplifying frequency  very low noise figures should
be attained by artificially cooling the idling resonant circuit
the use of the parametric principle as applied to frequency conversion
is discussed
   /
1639
a low noise electron beam parametric amplifier
   /
1640
the mavar a low noise microwave amplifier  the operation of the maver
mixer amplification by variable reactance requires a lossless nonlinear
reactance exhibiting negative resistance under certain conditions
low noise amplification is achieved at room temperature  the performance
and the operation of the main types of parametric amplifier are outlined
   /
1641
strongly nonlinear oscillations  mathematical analysis of a special
class of nonlinear oscillations in systems without or with losses
   /
1642
a note on thermodynamics of the harmonic oscillator with radiation
damping  it is shown that the impedance of an irreversible thermodynamical
system must be positive and real the argument is based on representation
of the system by langevin equations of the second order corresponding
to the construction of any passive network from elementary rlc
circuits  the conclusion is illustrated by an examination of the
properties of the harmonic oscillator
   /
1643
theory of the cathode sheath in a low density gas discharge  the
space charge equations of a low density gas discharge are derived
and applied to the study of potential distributions in the cathode
sheath  one conclusion is that a positive column will begin to evolve
when the number of ionization mean free paths in the discharge gap
is of the same order as the square root of the ratio of electron
to positive ion mass
   /
1644
the effect of a uniform magnetic field on electrodeless discharge
in a tube and measurement of electronic mobility
   /
1645
perveance and the bennett pinch relation in partially neutralized
electron beams  the concept of perveance is extended to take account
of relativistic conditions and the effects of space charge neutralization
see also of
   /
1646
magnetic forces and relativistic speeds in stationary electron beams
comment on of
   /
1647
a variational calculation of the equilibrium properties of a classical
plasma
   /
1648
correlations in the charge density of a classical plasma
   /
1649
nonlinear theory of plasma oscillations and waves  an exact differential
equation for density oscillations is found considering only coulomb
interactions between electrons  a number of properties of plasma
oscillations are then derived including the form of stationary spherical
waves in an isotropic plasma  see also of
   /
1650
thermal diffusion in ionized gases  the thermal diffusion factor
which is less than unity in a neutral gas mixture is of order in
an ionized gas where is the ionic charge  in a mixed ionized gas
containing also a small proportion of heavy ions the factor can be
much greater and give increased heavy ion density in the hotter regions
this effect may be of importance in the solar corona
   /
1651
experimental determination of the field of a permeable alloy cylinder
placed in a uniform magnetic field parallel to its axis of revolution
   /
1652
effective parameters in ferrimagnetic resonance  the steady state
solution for the susceptibility tensor of a two sublattice system
has been found by using sublattice equations of motion which include
complete landau lifschitz relaxation terms with individual relaxation
parameters and which describe relaxation toward the instantaneous
total field acting on the sublattice
   /
1653
spherical vortices in magnetohydrodynamic
   /
1654
propagation of waves through a sheet of the medium with a cubic periodic
structure  an approximate solution to the wave equation is obtained
for the case of normal and oblique incidence of the ingoing wave
and a detailed investigation is made of the case for which the wave
equation is separable
   /
1655
some electromagnetic transmission and reflection properties of a
strip grating
   /
1656
a general theory of magnetic resonance saturation  a general theory
for describing a spin assembly due to a nearly resonant rotating
magnetic field arbitrary strength is given  two different cases are
treated dependent on the relation between the static field and the
frequency of fluctuation of the environment
   /
1657
a microwave electron spin resonance spectrometer  a general description
is given of equipment which operates in the x and k bands and has
highly stable magnetic and microwave frequency systems
   /
1658
masers and related quantum mechanical devices
   /
1659
paramagnetic resonance in copper proprionate monohydrate  results
of an investigation at cm of absorption in single crystals
   /
1660
the influence of the anomalous magnetic moment on the spin kinematics
of electrons in a uniform magnetic field  high energy particles in
a beam are considered
   /
1661
proceedings of the third symposium on cosmical gas dynamics held
at the smithsonian astrophysical observatory cambridge massachusetts
june  papers presented deal with velocity fields in the interstellar
medium cooling and condensation of interstellar matter conditions
at the ionization and shock fronts in collisions of gas clouds and
related problems
   /
1662
polarization measurements of the three spectral types of solar radio
burst  a frequency sweep technique was used in the range most data
being obtained between and  data for type and type bursts cover the
period january october and for type the years and  many type bursts
were highly polarized and there were strong indications that the
polarization was due to the radiation source
   /
1663
evidence of echoes in the solar corona from a new type of radio burst
the bursts contain two elements spaced by sec the second being a
repetition of the first with a frequency increase with time of per
sec  an explanation is derived in terms of echoes from lower levels
of the solar corona
   /
1664
evidence on the spatial distribution of radio sources derived from
a survey at a frequency of  some results from a survey of radio sources
at are available for limited regions of the sky  these are discussed
in relation to the spatial distribution of sources
   /
1665
short ray burst from a solar flare  observations of a burst of radiation
are compared with simultaneous records of solar radio emission at
and
   /
1666
a suggested improvement to the cw technique for measurement of meteor
velocities
   /
1667
a search for magnetic effects from meteors  no magnetic pulses could
be detected as a result of meteors having visual magnitudes between
and  the sensitivity of the magnetometer used allowed pulses of and
later to be recorded  see also of
   /
1668
behaviour of the present sunspot cycle
   /
1669
geomagnetic dynamos  a rigorous proof is given of the dynamo theory
of geomagnetism by postulating a velocity pattern in a sphere filled
with conducting fluid so that the arrangement acts as a dynamo producing
an external magnetic field
   /
1670
a method for analysing values of the scalar magnetic intensity  the
method uses a series for the square of the scalar intensity the terms
of which are obtained from the spherical harmonics generally applied
to each component of the intensity  those magnetic characteristics
normally given by analysis of the vector intensity are obtained
   /
1671
large amplitude hydromagnetic waves above the ionosphere  arguments
are presented for the existence of waves of amplitude about times
that of geomagnetic fluctuations at the earths surface it is assumed
that the latter are generated at six to ten earth radii and carried
to earth by the waves  it is suggested that the waves produce irregularities
in electron density which cause radio star scintillation and
that they are also responsible for high intensity particle radiation
above about km
   /
1672
scientific reports of the french polar expeditions magnetic activity
in the polar regions
   /
1673
measurement of the earths magnetic field with a rubidium vapour magnetometer
the instrument described makes use of the relationship between
the earths field and the absorption lines in rb vapour caused by
ground state zeeman transistions  an absolute accuracy of is quoted
see also of
   /
1674
geomagnetic activity and eruptions  statistical analysis of observational
data to determine the relation between various types of solar
flare and increases in geomagnetic activity
   /
1675
igy progress report  a general report of contributions made by members
of the rsgb to the igy program
   /
1676
igy vhf programme progress to date  the report compiled from observations
made by members of the rsgb deals with an analysis of the origin
of different air masses in relation to tropospheric propagation conditions
fading auroral reflection propagation and solar noise
   /
1677
hit rates of radio propagation disturbance warnings and swi warnings
in order to improve the hit rate defined as the number of hits divided
by the number of issued forecasts it is suggested that long distance
propagation characteristics should be studied to account for the
fall in hit rate in winter that forecasting should be reduced to
three or four days ahead and that although swi warnings are fairly
good there should be a further study of solar radio noise
   /
1678
gravitational torque on a satellite vehicle
   /
1679
motion of the nodal line of the second russian earth satellite and
flattening of the earth
   /
1680
air drag effect on a satellite orbit described by difference equations
in the revolution number  difference equations are derived whose
solutions express changes in orbital size and shape and give the
satellites time behaviour as functions of the revolution number
the results are obtained from a first order perturbation theory using
a small air drag parameter and assuming the air density function
to be locally exponential  see also of
   /
1681
on the reception of radio waves from russian earth satellite i  observations
of bearing and field strength are used to determine the orbit
and to estimate regions of reception taking into account the various
modes of ionospheric propagation
   /
1682
radio reflections from satellite produced ion columns  the records
of signal strength of wwv transmission on measured at the university
of illinois were examined for periodic variations due to reflection
from ion columns  the results do not indicate the presence of such
columns for extremely high satellites  see also of
   /
1683
satellite tracking its methods and purpose  radio radar and optical
techniques are discussed
   /
1684
keeping track of earth satellites  details are given of an interferometer
type aerial array having dipoles proximity coupled to a two wire
transmission line  a receiver with inputs switched at is used to
detect signals below receiver noise level  calibration methods are
described and some transit passage records accurate to within sec
are shown
   /
1685
telemetering information from satellites  the data given cover both
ussr and us satellites  channel assignments for the lyman environmental
satellites are tabulated and general notes on recording technique
are included
   /
1686
pressure and temperature variation of the electron ion recombination
coefficient in nitrogen  the variations have been investigated in
the pressure range mm hg and for electron temperatures between and
at mm hg varies from at  dissociative recombination is the most probable
mechanism
   /
1687
computations of electron density distributions in the ionosphere
making full allowance for the geomagnetic field  jacksons method
of for computing the distributions from records has been slightly
modified for use on an electronic computer  each reduction takes
about secs  it is assumed that the electron density between two layers
falls to of the lower layer value  night time distributions for brisbane
australia are found to be nearer to the chapman than to the parabolic
form
   /
1688
long term variations of the sporadic e layer in japan  statistical
analysis of layer reflections at four observatories during shows
marked diurnal and seasonal variations in  no annual variation is
observed nor any correlation with sunspot number  an analysis of
the occurrence of reflections above certain limiting frequencies
at one observatory yields similar results
   /
1689
on the influence of electron ion diffusion exerted upon the formation
of the layer  the maximum electron density of the layer and its height
are obtained theoretically as functions of latitude and solar zenith
distance  the theoretical height distributions derived are thinner
than chapman distributions and the effective recombination coefficient
decreases with height at low altitudes but becomes constant at high
altitudes  no better agreement between theory and observation is
obtained when a vertical electron ion drift velocity is considered
see also of
   /
1690
on the world wide distribution of  the coefficients a and b in the
relation where sunspot number are separated into components which
are constant and those which vary diurnally and annually see of
examination of these components for stations shows a geomagnetic
latitude control of the constant component while there is no significant
difference between control by geomagnetic or geographic latitude
for the varying components
   /
1691
solar cycle influence on the lower ionosphere and on vhf forward
scatter  seven years results at for the cedar rapids sterling path
have been analysed to determine the effect of the solar cycle  the
monthly median signal intensity for the noon and afternoon period
is found to follow the same trend as the sunspot number and the magnetic
disturbance index
   /
1692
ionospheric observations made at freiburg during the solar eclipse
of june
   /
1693
lunar tides in at brisbane
   /
1694
the magnetic field in the layer at dakar  the gyrofrequency is calculated
from observed values of and its variations as a function of reflection
height and time are analysed
   /
1695
anomalous changes in the ionosphere related to a severe magnetic
storm oct  examination of world wide geomagnetic and ionospheric
data shows the existence of a short lived electrojet stream with
associated anomalous changes in layer electron density  two possible
mechanisms are suggested the formation of a new layer due to corpuscular
streams and the vertical drift of electrons resulting from interaction
of the geomagnetic field with currents in the layer returning from
the main electrojet in the e region  see also of
   /
1696
layer deduced from the frequency spectrum of radio propagation figures
at long distance routes  the hourly radio propagation quality figures
for wwv received at many stations in canada were used as basic data
assuming a suitable height for the layer its critical frequency at
the reflection point of a transmission path could be obtained  the
values calculated compared fairly well with those obtained from vertical
incidence soundings provided the correct mode of propagation had
been used for the transmission path  this analysis was also carried
out during magnetic storms where no vertical incidence observations
were obtainable
   /
1697
thermal structures in the lowest layers of the atmosphere  temperature
variations recorded simultaneously at heights of and were examined
statistically correlation between a pair of such records was greatest
at a time displacement depending on wind speed difference between
the two heights  the evidence suggests organized thermal structures
of great vertical extent
   /
1698
the geometry of auroral ionization  new evidence is presented which
shows that vhf radio echoes from auroral ionization are reflections
from aspect sensitive columns aligned with the earths magnetic field
   /
1699
displacements of the radiant point during the auroral disturbance
of september  photographs of auroral corona enabled the position
of the radiant point and its motion to be determined accurately
the motion was unrelated to the displacement of the magnetic zenith
as determined from measurements on the ground
   /
1700
auroral radiation at  observations of rf noise emissions from aurorae
were made udring a type a red auroral display on october  this unusual
display was linked to a large flare on the sun some earlier  theoretical
considerations indicate that a large particle flux would produce
such auroral radio emission
   /
1701
a comparison of radio echoes from the aurora australis and aurora
borealis  observations of echoes on made at halley bay antarctica
for the period may october are compared with contemporary observations
made at jodrell bank  the great aurorae of the northern hemisphere
are probably accompanied by greatly enhanced simultaneous activity
of aurora australis
   /
1702
vhf observations on the aurora australis  an investigation of radar
echoes at is reported  the range exponent in the radar equation is
calculated as and a maximum value of reflection coefficient was
mechanisms of reflection are discussed and only those involving column
models are substantiated  see also of
   /
1703
some properties of lightning impulses which produce whistlers  results
obtained at stanford california and boulder colorado show that a
characteristic waveform having an intense energy peak near is frequently
associated with the impulse which produces a whistler  whistler producing
discharges appear to be more frequent over sea than over land
identification of the causative impulse should be based on waveform
analysis as well as the time of occurrence
   /
1704
polarization of atmospheric pulses due to successive reflections
from the ionosphere  explanations are offered of the more complex
patterns observed on a crossed loop cr tube direction finder for
atmospherics  in addition to the normal straight line display of
an atmospheric pulse elliptic traces or groups of straight lines
within a small angle are produced  elliptic traces are explained
by polarization at ionospheric reflection and groups by radiation
from branch points in a nearly horizontal cloud to cloud lightning
flash  see also of and of
   /
1705
solar activity and whistler dispersion  the time delay between the
occurrence of a local lightning flash and the beginning of the associated
whistler is correlated with the monthly mean sunspot number  the
correlation coefficient is greatest when the sunspot number is related
to whistler measurements made months later
   /
1706
designing transistor dc to ac converters  nomograms are presented
for the design of the basic two transistor saturable core symmetrical
circuit
   /
1707
silicon power rectifiers  a technique is described for the construction
of alloy junction rectifiers
   /
1708
germanium and silicon industrial rectifiers  a review of methods
of construction and applications
   /
1709
the theory of ballast tubes or barretters  results are given which
explain the observed behaviour of various low voltage barretters
a better combination than iron wire in hydrogen is unlikely to be
found
   /
1710
stabilization by zener diodes  elementary design principles are discussed
   /
1711
computation in the presence of noise  an analysis of the problem
of performing reliable computation with elements which are themselves
unreliable  the effects of the coding procedures on the reliability
are discussed
   /
1712
control apparatus for a serial drum memory  a detailed circuit description
of equipment used for obtaining design data for fast track switching
on a serial drum magnetic storage device
   /
1713
matrix programming of electronic analogue computers  the technique
is based on establishing a correspondence between the matrically
formed differential equations and the computer networks  this simplifies
the setting up of the computer and reduces the possibility of errors
examples are given of the use of the method
   /
1714
a magnetic drum store for analogue computing  large storage capacity
combined with relatively short access time is obtained  the drum
can be used for generating nonlinear functions and as a delay network
   /
1715
an electrical multiplier utilizing the hall effect in indium arsenide
details are given of the construction and performance of a multiplier
for computer applications in which an inas hall plate is mounted
in the gap in a ferrite core
   /
1716
multiplication by semiconductors  the modes of operation of analogue
computer multipliers using the hall effect in semiconductors are
discussed  some experimental multipliers and the results obtained
with them are described  the application of the magnetoresistive
effect is outlined
   /
1717
the design of logical circuits using transistors and square loop
ferrite cores  some basic circuits are reviewed and a range of practical
designs and design procedures is given
   /
1718
some aspects of the network analysis of sequence transducers  an
algebraic formulation is presented for use in the analysis of networks
of the synchronous type of sequence transducer  see also of
   /
1719
design and performance of air cooled chassis for electronic equipment
future electronic components  to obtain substantial reduction in
size components will probably consist of thin films of resistive
dielectric magnetic and conductive materials and film type or flat
plate semiconductor devices will be used
   /
1720
foil clad laminates in printed circuitry
   /
1721
simplified mains transformer design  the power handling capabilities
of various laminations are tabulated and the design procedure is
illustrated by an example
   /
1722
measurement of parameters controlling pulse front response of transformers
   /
1723
a study of the neon bulb as a nonlinear circuit element
   /
1724
a method of electrolytic etching of tantalum for capacitor use  etching
of foil in a bath of trichloroacetic acid sodium trichloroacetate
and methanol produced an increase of in capacitance relative to a
capacitor formed of unetched foil  the lagrange equations in electrical
networks
   /
1725
ultrasonic mercury delay lines  the construction and characteristics
of lines and transducers are discussed
   /
1726
analysis of millimicrosecond rf pulse transmission  the analysis assumes
a quadratic approximation for the complex propagation constant and
a transmitted pulse with gaussian envelope  the theory is applicable
to uniform microwave transmission systems and relates pulse shapes
with the cw properties of the system
   /
1727
fabrication techniques for ceramic x band cavity resonators  techniques
are described for constructing cavity resonators for the x band from
low thermal expansion ceramics  a variety of mechanical arrangements
is discussed  q values as high as and frequency temperature coefficients
as low as part in per have been obtained using simple processes
   /
1728
a correlation between stagger tuned and synchronously tuned coupled
circuits  application of a network theorem enunciated by green
   /
1729
time symmetric filters  methods are described for simulating filters
that have impulse responses symmetrical in time and their application
to the analysis of gliding tones is discussed  the response of a
narrow band time symmetric filter to a gliding tone is evaluated
and shown to consist of an oscillation bounded by a slowly varying
envelope  the shape is governed by a parameter involving the bandwidth
of the filter and the rate of variation of the instantaneous frequency
of the tone
   /
1730
design curves for simple filters  charts are given for the design
of simple lc ladder filters with either butterworth or tchebycheff
type of response
   /
1731
nomographs for designing elliptic function filters
   /
1732
simplified design of resonant notch filters for servo applications
data are given in graphical form for the design of stagger tuned
constant band stop filters applications to error rate damping in
servo systems are discussed
   /
1733
the reduction of low frequency noise in feedback integrators  a considerable
improvement in signal noise ratio compared with that of a conventional
direct coupled integrator is obtained either by using an error
amplifier containing a single cr coupling or by applying phase correction
to the output from a low accuracy direct coupled integrator
   /
1734
thermally compensated crystal oscillators  frequency stability is
achieved by using thermistors in a temperature sensitive phase shifting
network incorporated in the oscillator circuit  a stability of about
in is obtained over a wide frequency range without thermostats or
ovens  it is suggested that even better compensation would be achieved
by attaching the thermistor bead to the crystal
   /
1735
a quartz servo oscillator  a description of a quartz oscillator stable
to parts in with dual stabilization by resonant loop balance and
bridge operated servo control
   /
1736
checking crystal oscillators  simple measurements are suggested to
ensure that a crystal will oscillate in a specified circuit without
damage and at the required frequency
   /
1737
a constant amplitude random function generator  a generator is described
for producing a wave shape with constant peak to peak amplitude but
whose path between peaks is random  circuits for random sawtooth
triangular cosine and square waves operating in the af range are
described
   /
1738
some novel circuits employing cold cathode tubes  the circuits described
are based on cold cathode diodes and triodes the diode being used
to stabilize the anode breakdown voltage of the triodes  details
are given of a stable relaxation oscillator a voltage discriminator
trigger circuits a staircase waveform generator and decade counters
   /
1739
pulse forming networks
   /
1740
the excitation of ionic spectra by high frequency pulses  equipment
previously described has been developed and provided with a power
amplifier containing a water cooled triode  pulse powers up to approximately
are applied to a discharge tube with pulse duration and repetition
frequency sec
   /
1741
a distributed circuit pulse height analyser  a multichannel analyser
using distributed circuits and having a resolving time of is briefly
described
   /
1742
frequency dividers using transistors  regenerative frequency dividers
using junction and point contact transistors are described and results
are given of an experimental investigation
   /
1743
video amplifier design using the pcl  optimum gain is achieved by
the use of anode compensation  bias methods for this condition are
discussed
   /
1744
ultra high frequency power amplifiers  a general review of the design
and construction of power amplifiers operating in the range  travelling
wave valves designed for a bandwidth of one octave are limited in
their mean power output by overheating of the helix  backward wave
amplifiers based on crossed field interaction require a variable
beam voltage for wide band operation but have a high efficiency and
low operating voltage
   /
1745
a note on the design of transductors for maximum power transfer
magnetic amplifiers giving maximum power output for a given size
of core are designed by known graphical and numerical methods  theoretical
and experimental results are compared
   /
1746
ac controlled magnetic amplifiers  a method is described for controlling
full wave amplifiers with ac signals  the response characteristic
is similar to that of dc controlled amplifiers and high gain is achieved
with no current limiting resistors or demodulator  the method is
based on cancelling the induced emf in the control circuit
   /
1747
proposed standard terms and definitions for magnetic amplifiers
an aiee committee report on the terminology used  terms are defined
   /
1748
a sliding bias amplifier using an  the two stage circuit described
and analysed in detail gives nearly twice the output power obtainable
in conventional class a operation using a heat sink of the same size
   /
1749
videa amplifiers using alloy junction transistors  grounded emitter
video amplifier stages are analysed theoretically using compensated
and uncompensated circuits  abacs and charts are given to facilitate
design procedure for multistage amplifiers together with the practical
design of an amplifier with gain and bandwidth
   /
1750
pulse amplifier with nonlinear feedback  the transistor amplifier
described provides constant output over a range of input signals
   /
1751
transistor tape preamplifier  the play back head is used as the inductance
in a feedback inductance resistance integrating circuit  a signal
noise ratio is obtained and the frequency response is flat within
from to
   /
1752
proposal for a maser amplifier system without nonreciprocal elements
a system noise temperature of or less should be obtainable by using
two matched masers and a lossless power dividing network such as
a hybrid t
   /
1753
characteristics of the beam type maser part  an experimental investigation
of the characteristics of an ammonia maser for use as a frequency
standard  measurements of the effect of focusing voltage and cavity
tuning on frequency are compared with theory and the effect of the
velocity spread of the molecules is estimated  part of
   /
1754
parametric amplifier ups scatter range  a sidiode parametric amplifier
see of january is used and extends the range of a link from to miles
receiver noise factor is reduced from to
   /
1755
the wider scope of optics  the development and applications of new
optical and optical electronic devices are considered  references
   /
1756
the application of onsagers theory to dielectric dispersion  a new
equation for the complex dielectric constant which includes the proper
effect of the reaction field is developed for the case of an alternating
applied field  it is shown to yield results very close to those obtained
with the simple debye equation for the complex dielectric constant
   /
1757
experimental evidence for an energy gap in superconductors
   /
1758
wire cylinder electric discharges in air in relation to the space
charge field emission hypothesis  study of experimental data on wire
cylinder discharges in relation to the field emission hypothesis yields
graphical and arithmetic methods of finding the effective field at
the time of flash initiation and the space charge field at the wire
the effective field is of the order of and is interpreted as a measure
of the emission field of the cathode metal or of the ionized air
see also of
   /
1759
ultra high frequency gas breakdown between ragowski electrodes  breakdown
voltage electrode spacing electrode size and gas pressures are
observed for air and at
   /
1760
the relativistic flow of electrons in parallel and radial straight
lines with no externally imposed magnetic field  analysis is given
of the possibility of producing relativistic electron flows  it is
shown that they could not start from a cathode surface where the
electrons have zero speed  the analysis also applies to flows normally
considered nonrelativistic in diodes where the linear dimensions
of the electrode surfaces are large compared with the electrode spacing
of
   /
1761
electron cooling by heat exchange  a new method for obtaining homogeneous
electron streams is described  by making the electron stream part
of a plasma beams with densities of up to and currents exceeding
have been achieved
   /
1762
coherence requirements for interferometry  an analysis of the theory
of double beam interferometry based on that of d gabor  gabors restrictive
assumptions are clarified and generalized
   /
1763
energy spectrum of a electron beam reflected by a metallic object
the energy spectra of electrons reflected from different metallic
targets are investigated by means of a magnetic spectrograph
   /
1764
transport phenomena in a completely ionized two temperature plasma
a theoretical investigation of particle motion and heat transfer
in a plasma of electrons and positive ions under the influence of
both electric and magnetic fields the electron and ion temperatures
being considered different
   /
1765
the amplification of a magnetic field by a high current discharge
it is shown theoretically that a helical current flow discharge is
set up by a longitudinal magnetic field in which the plasma pressure
is balanced by electrodynamic forces  the direction of the helix
is such that the initial longitudinal field is amplified  some experimental
evidence supports this theory
   /
1766
transport phenomena in completely ionized gas considering electron
electron scattering  hall mobility and other transport properties
of electrons in a completely ionized gas have been investigated when
a magnetic field is applied taking into account electron electron
scattering  results have been presented for different mean ionic
charges
   /
1767
the magnetic fields of a ferrite ellipsoid  approximate expressions
are found for the internal and the adjacent external magnetic fields
of a small ferrite ellipsoid under plane wave excitation  consideration
is given to the variation of apparent susceptibility with the size
of the ferrite
   /
1768
classical electrodynamics as a distribution theory part
   /
1769
application of distributions to the equations of maxwell and helmholtz
distribution theory is applied to give a new concept of an element
of current
   /
1770
singular electromagnetic induction  extension of the concepts discussed
in of
   /
1771
algebraic study of the electromagnetic tensor in the presence of
induction  see above
   /
1772
electromagnetic radiation from electrons rotating in an ionized medium
under the action of a uniform magnetic field  the radiation is shown
to be predominantly in the extraordinary mode  at the harmonics of
the gyrofrequency of the fast electron the power radiated in the
ordinary mode is a small percentage of that in the extraordinary
mode but at the fundamental gyrofrequency it is lower by a factor
where is the velocity of the fast electron and is the velocity of
light  the gyro theory of the suns nonthermal radiation is discussed
this mechanism cannot explain the phenomena associated with noise
bursts of type and although it is conceivable that type bursts may
be of gyro origin
   /
1773
theory of electromagnetic waves in a crystal with excitons
   /
1774
the characteristics of an electromagnetic wave reflected from a moving
object
   /
1775
diffraction by a wide slit and complementary strip  the diffraction
of e and h polarized waves by an infinite slit is considered  induced
current densities aperture and far fields and the transmission coefficient
are calculated in the form of infinite series in inverse powers
of the slit width wavelength ratio  the solution for diffraction
by a strip is also obtained  a comparison is made with previous results
this method appears to provide accurate information when the slit
width is greater than a wavelength
   /
1776
variational principles in high frequency scattering  two variational
principles are formulated for two dimensional scattering by obstacles
the more successful of these treats the obstacle like an aperture
coupling two half spaces  the zero order calculation for the cross
section of a circle is found to have the correct frequency dependence
   /
1777
scattering from a small anisotropic ellipsoid  scattering of an electromagnetic
wave by a small ellipsoid having tensor permeability and
dielectric properties is dealt with by expanding the fields as power
series in  consideration has been given to the first three terms
of the expansion
   /
1778
contribution to the theory of electromagnetic wave propagation in
media with random heterogeneities of the refractive index  a correlation
function is derived which can be used in connection with em wave
diffraction problems
   /
1779
scattering of plane waves by locally homogeneous dielectric noise
when plane waves are scattered by locally homogeneous dielectric
noise random refractive index fluctuations and observed in the fraunhofer
region it is found that the local structure of the noise determines
the average scattered power received at a fixed point whereas its
overall structure determines the space correlations of the radiation
received at two different points
   /
1780
criteria determing the design and performance of a source modulated
microwave cavity spectrometer  an analysis is given of the radio
and audio frequency modulation method employed in microwave spectroscopy
the results of the theory are compared with measurements taken
on a microwave spectrometer and are found to be in close agreement
the calculations are extended to include the case where an absorbing
gas is enclosed in a resonant cavity
   /
1781
direct measurement of electron spin lattice relaxation times  a discussion
of the experimental problems encountered in making spin lattice
relaxation measurements in electron paramagnetic systems at low temperatures
gadolinium and chrome ion spin lattice relaxation times are
given  the relation of these spin lattice relaxation times to relaxation
times measured in the frequency domain by observing a saturation
parameter is discussed
   /
1782
the electron structure of transition metals and alloys and heavy
metals
   /
1783
energy spectrum of particles bombarding the earth  the estimated
fluxes of interstellar and auroral particles appear to fit the straight
line portion of the cosmic ray integral energy spectrum extrapolated
to lower energies
   /
1784
osnic radio astronomy  a brief description of the fields of exploration
opened by developments in radio astronomy
   /
1785
on the radio emission of hydrogen nebulae  random variations in electron
density and electron temperature through the nebulae are shown to
alter the optical depth  radio emission of stromgren spheres is also
discussed and an empirical method for determining stromgrens constant
is described
   /
1786
an investigation of the strong radio sources in centaurus fornax
and puppis
   /
1787
a catalogue of radio sources between declinations and
   /
1788
investigations of persistent solar sources at centimetre wavelengths
measurements of the brightness distribution and apparent size of
solar rf sources made at cm with an interferometer alon et al show
that small apparent diameters are associated with periods of eruptive
solar activity
   /
1789
the dimensions of sources of bursts of solar radiation at centimetre
wavelengths  sources are classified the growth and decay in their
apparent size are observed and their equivalent temperature estimated
on the basis of interferometer measurements at cm
   /
1790
outer corona of the sun  radio emissions from the crab nebula passing
through the corona are observed by an interferometric method  the
results indicate that the outer corona extends to a distance of sun
radii
   /
1791
amplitude scintillation of extraterrestrial radio waves at ultra
high frequency  measurements are described which show that at latitude
ionospheric scintillation effects are still significant at when the
radio star is near the northern horizon
   /
1792
electromagnetic radiation from electrons rotating in an ionized medium
under the action of a uniform magnetic field  see
   /
1793
ionizing radiation associated with solar radio noise storm  comparison
of records obtained during a storm on august from three balloon borne
detectors a single counter counter telescope and ion chamber indicates
the appearance of protons with kinetic energy of mev
   /
1794
solar brightness distribution at a wavelength of centimetres part
localized radio bright regions  observations were taken with a element
interferometer with a beam width of min of arc from july to march
sources of radio brightness were found to be closely correlated with
sunspot areas  their estimated size lay between and min of arc  sometimes
their slowly varying component showed marked changes in intensity
over periods of half an hour  the largest radio brightness temperatures
measured were about part of
   /
1795
flare puffs as a cause of type radio bursts  type bursts occur within
min of two thirds of the flare puffs  most puffs are followed by
surges and this suggests two ejections of differing velocities one
at about the velocity of light causing the burst and the other at
km sec causing the surge  see also of loughhead et al
   /
1796
optical observations of the solar disturbances causing type radio
bursts  type radio bursts have been identified with ejections having
velocities exceeding that of sound in the corona for events near
the limb and with very bright flares with dark filament activity
when the event is on the disk
   /
1797
on the great solar flare which started at february as the likely
source of geomagnetic storm february  it is shown that there is a
high probability that the flare caused the magnetic storm  experimental
evidence is given supporting a connection between the early part
of a solar noise burst and a short wave fade out and between the
late part and magnetic storm occurrence
   /
1798
radio wave propagation and soil conductivity  description of a scheme
for mapping the soil conductivity throughout the soviet union by
radio techniques
   /
1799
the external magnetic field of the earth  the discrepancy between
the equivalent geomagnetic dipole based on cosmic ray observations
and that derived from surface observations is investigated  see also
of
   /
1800
reversals of the earths magnetic field  calculations made by rikitake
have been extended by the use of a digital computer
   /
1801
balloon gear monitors cosmic radiation  the balloon with a lb load
can be flown at altitude for hours  equipment carried includes an
omnidirectional geiger counter a spherical integrating ionization
chamber and telemetry equipment
   /
1802
electron density profiles in the ionosphere during the igy  note
on a program organized by the radio research station slough england
of using electronic computers in the preparation of profiles from
ionograms obtained at four observatories
   /
1803
investigation of upper layers of the atmosphere by means of rockets
and artificial earth satellites  description of possible methods
of investigation and the nature of the instrumentation required
   /
1804
scientific investigations by means of artificial earth satellites
a description of sputnik and the scientific equipment carried by
it
   /
1805
the determination of the trajectory of artificial satellites  methods
and the arrangement of ground equipment are described
   /
1806
exact determination of the velocity of an artificial satellite  doppler
measurements enable the velocity of the satellite to be measured
to an accuracy within part in
   /
1807
doppler measurements on soviet satellites  the first two soviet satellites
were successfully tracked by means of doppler measurements alone
the apparatus and the method of analysis used are described
   /
1808
observations of radio signals from the first man made earth satellite
   /
1809
radio observations on the first russian artificial earth satellite
doppler measurements made at johannesburg at are reported  orbit
calculations are made neglecting ionospheric effects  see also of
   /
1810
radio observation of the earth satellite  describes observations
of field strength bearing and doppler shift of the signal  it is
considered that to explain anomalous field strengths and doppler
shifts propagation involving ground scattering followed by ionospheric
reflection must be considered  anomalous doppler effects include
rapidly varying shift and apparent recession when the satellite is
approaching the receiver
   /
1811
last minutes of satellite
   /
1812
cosmic rays observed by satellite  an analysis of the telemetered
cosmic ray information received in japan  except during magnetic
storm conditions the number of cosmic rays decreases exponentially
with height  diurnal and storm variations are discussed
   /
1813
effect of solar flares on earth satellite  fluctuations in the rate
of decrease of the period of the satellite are apparently connected
with variations in the total intensity of solar flares
   /
1814
faraday fading of earth satellite signals  a corrections to the existing
method of estimation of the integrated electron content of the ionosphere
from earth satellite signals is given
   /
1815
incoherent scattering of radio waves by free electrons with applications
to space exploration by radar  a powerful radar can detect the incoherent
back scatter from free electrons in and above the earths atmosphere
and the received signal is spread in frequency by the doppler shifts
associated with the thermal motion of the electrons  many practical
applications are discussed including measurements of electron density
electron temperature auroral ionization and radar echoes from the
sun venus and mars
   /
1816
main results of meteorological research done in hungary during the
years  work on the ionosphere carried out by the central meteorological
institute is noted
   /
1817
prevailing wind in the ionosphere and geomagnetic variations  it
is shown theoretically that the prevailing ionospheric wind makes
no contribution to the geomagnetic current system despite the diurnal
variation of ionospheric conductivity  see also of
   /
1818
a study of spread f ionospheric echoes at night at brisbane part
range spreading  from an examination of the variation of the amount
of range spreading produced by sweeping the gain of a fixed frequency
ionospheric recorder it is possible to gauge the degree of roughness
of ionospheric layers  the effective roughness is a function of the
separation of transmitter and receiver being less the greater the
distance between them  the intensity of z ray echoes recorded in
brisbane is consistent with elliss theory  part of
   /
1819
on the short wave transmission disturbance of
   /
1820
measurement of the size and electrification of droplets in cumuliform
clouds  charge distributions in clouds with fair weather electric
fields at a mountain site in the united states were gaussian with
symmetry about zero charge  thundercloud droplets were highly electrified
and in a given volume could be all negatively or all positively
charged or a mixture of the two
   /
1821
auroral echoes in the ionograms obtained in the minauroral region
the observation of auroral echoes on a frequency sweep ionosonde
at kokabunji in japan is reported  echoes were seen on three magnetically
disturbed days on one of which visual aurora was observed in japan
the echo range corresponds to normal incidence reflection from scattering
centres at f layer heights
   /
1822
correlation of whistlers and lightning flashes by direct and visual
observation  lightning was observed simultaneously with whistlers
at hanover nh on may but it is concluded that most lightning flashes
do not generate whistlers
   /
1823
waveforms of atmospherics  a classification and interpretation of
observed waveforms is given  see also of tantry et al and for a description
of the equipment of tantry
   /
1824
transistor stabilized power supply for  circuit details of a unit
with output resistance and output voltage variation or less for change
in input voltage
   /
1825
a transistor regulated power supply for video circuits
   /
1826
solar battery  the battery consists of silicon plates about mm thick
covered by thin boron films forming junction photo elements  the
efficiency of the battery is approximately and a possible improvement
up to is indicated
   /
1827
some basic physical properties of silicon and how they relate to
rectifier design and application
   /
1828
a constant voltage constant current stabilizer
   /
1829
current balancing reactors for semiconductor rectifiers  in both
semiconductor and mercury arc rectifiers of high current capacity
where many diodes are connected in parallel the currents in the separate
units must be balanced  balancing arrangements for semiconductor
rectifiers are described including the use of punched laminations
as strip type reactors
   /
1830
the analysis and design of constant voltage regulators
   /
1831
rapid testing of electronic direct voltage stabilizers  routine tests
of voltage stabilizers at an electron optics laboratory in toulouse
are described
   /
1832
semiconductor thermostat for self oscillators  the thermostat provides
control for an ambient temperature range of to
   /
1833
how to improve relay reliability  practical advice is given on the
choice and use of electromechanical relays
   /
1834
electronic computer exhibition  short notes on special features of
computers shown in london from november to december
   /
1835
learning machines  a conditional probability computer and character
recognition machines exhibited at the symposium on the mechanization
of thought processes held at the national physical laboratory from
to november are discussed
   /
1836
ferroelectric storage devices  the switching characteristics of ferroelectric
materials as required for use in digital storage systems are
examined  the properties of single crystal capacitors are investigated
experimentally
   /
1837
a track switching system for a magnetic drum memory
   /
1838
phase selective gate rejects quadrature  a phase reference voltage
controls two unmatched diodes which conduct only when the in phase
component is at maximum and the quadrature component at minimum
a circuit designed for a servo amplifier is described
   /
1839
transformer design for zero phase shift
   /
1840
bounds for thermistor compensation of resistance and conductance
   /
1841
an introduction to the use of transistors in inductive circuits
the mechanism of a delayed switch off effect which is due to avalanche
multiplication is described and a method of avoiding it in relay
switching circuits is given
   /
1842
transistor switch design  switching parameters are tabulated for
eight types of transistor
   /
1843
an experimental gas diode switch  the ac impedance is a stable negative
resistance of about for frequencies up to
   /
1844
dielectric films in aluminium and tantalum electrolytic and solid
tantalum capacitors
   /
1845
ferrite cored capacitors  details are given of british capacitors
with ferrite loading for improving their attenuation characteristics
   /
1846
ire standards on audio techniques definitions of terms
   /
1847
a review on the analysis of transients in electrical circuits using
the laplacian transformation
   /
1848
general power relationships for positive and negative nonlinear resistive
elements  the method developed by manley and rowe for the treatment
of reactive elements is extended to resistors  relations are derived
which yield modulation efficiency efficiency of harmonic generation
and stability criteria
   /
1849
how quickly does a twin t respond  the response to three different
input waveforms is examined using the laplace transformation  in
all cases the output transient is negligible after cycles of the
resonance frequency of the network
   /
1850
filter attenuation characteristics  the use of hyperbolic functions
is avoided aad formulae are derived which permit slide rule computation
   /
1851
the magnitude of the permissible circuit impedances of the filters
in if amplifiers for fm systems  application of results obtained
in of
   /
1852
a three band aerial combining network  three prototype filter sections
of low pass band pass and high pass characteristics respectively
for bands and are combined in a masthead unit to provide a common
output for the three aerial inputs
   /
1853
normalized input admittance curves of two stage band filters and
the smallest mismatch circles for a given frequency range
   /
1854
band filters with electronic bandwidth control  the design of a two
stage filter with amplification in the feedback line is considered
   /
1855
null point band filters and their theoretical treatment
   /
1856
the frequency and time characteristics of all pass filters for delay
equalization in television transmission  the basic circuits given
by bunemann are considered
   /
1857
some properties of a frequency stabilizing circuit
   /
1858
the wave mechanical damped harmonic oscillator  a wave mechanics
treatment is given of damped harmonic motion for the charge in a
tuned circuit and the em field in a resonant cavity  the classical
frequency appears in the time dependence of the eigenfunctions and
the classical damping as a decay in the eigenvalues
   /
1859
high q echo boxes  an investigation of the occurrence of unwanted
modes in a tunable h cylindrical cavity  suggestions for the suppression
of these modes are given
   /
1860
generations of oscillations with equally spaced frequencies in a
given band
   /
1861
the application of pulse forming networks
   /
1862
miller sweep circuit  circuits are described in which both miller
integrator and puckle flyback circuits are combined to produce a
very linear time base
   /
1863
bistable circuits using unijunction transistors  the design and operation
of various circuits are explained  use of the negative resistance
region as one stable state decreases power requirements and increases
switching speed  the application to ring counter circuits is shown
   /
1864
transistor oscillator with output  a design procedure is described
for transistor oscillators employing external feedback and an lc
resonator  an example is given which delivers an output of at and
which operates from a battery  it is suitable for use as a bias oscillator
for dictation machines
   /
1865
graphical designing of transistor oscillators  a method is described
which is simple but yields results accurate enough for most engineering
design calculations  a design example is given for a crystal controlled
oscillator to operate at
   /
1866
summary of the theory of wide band distributed amplifiers suitable
for the amplification of very short pulses
   /
1867
dc amplifiers for control systems
   /
1868
an electronic multicoupler and antenna amplifier for the vhf range
   /
1869
a triode connected pentode with stabilized anode current  drift in
dc coupled circuits caused by heater supply voltage variation is
minimized by the use of a triode connected pentode stabilized by
variation of grid current with emission
   /
1870
the influence of the output time constant of a cathode follower
a nomogram is derived for determining the maximum pulse amplitude
as a function of rise time and output time constant that may be applied
without causing positive grid current
   /
1871
a low capacitance input circuit  methods of reducing the effect of
coaxial cable capacitance are discussed  a probe containing only
passive elements is used with a single triode pentode valve feedback
amplifier to give an input capacitance of and a gain of unity over
a bandwidth of
   /
1872
properties of hook transistors in switching and amplifying circuits
an analysis is given of the most significant properties of hook and
pnpn transistors in common base common emitter and commmon collector
configurations  stagger tuned transistor video amplifiers
   /
1873
transistor circuits based on the half supply voltage principle  analysis
shows that temperature stabilization of a transistor can be effected
by a preceding dc coupled amplifying stage stabilized on the half
supply voltage principle  practical circuits are described for af
amplifiers and stabilized supply units  see also of january dammers
et al
   /
1874
analysis of the emissive phase of a pulsed maser  a discussion of
the emission from a matched cavity at paramagnetic resonance  results
are given for transverse moment output field output power and power
gain as a function of time
   /
1875
transistor circuit engineering
   /
1876
report of the meeting of the swiss physical society  the text is
given of papers read at a meeting held at neuchatel september including
the following electrical properties of silver selenide  oscillatory
magnetic resistance variation of n type insb at low temperatures
and high field strengths  the field parameters of galvano and thermo
magnetic effects in ferromagnets  hall and righi leduc effects in
ferromagnetics  effect of a cubic electric field on the fundamental
level of the gd ion  hyperfine splitting in the paramagnetic resonance
of pr in ceramic in german  improvements in an nh maser
   /
1877
magnetic susceptibility of an electron gas at high density
   /
1878
the electrostatic interaction of two arbitrary charge distributions
   /
1879
molecular theory of the dielectric constant  a theory of the static
dielectric constant is developed on a quantum mechanical basis  by
introducing the concept of local field a molecular version of the
general theory is obtained  it is shown that such a molecular theory
is fundamentally ineffective in accounting for the observed results
within the experimental accuracy
   /
1880
quantum theory of the high frequency conductivity of metals  development
of the theory of conductivity of a metal in a high frequency em field
and a constant magnetic field  the amplitude of the quantum oscillations
in the high frequency case is usually larger than in the static case
   /
1881
quantum oscillations of the high frequency surface impedance  a quantum
mechanical formula is derived and cases involving constant magnetic
fields both parallel and inclined to the surface are considered
from an experimental study of surface impedance in a strong magnetic
field the shape of the fermi surface and the velocity of the electrons
in it can be determined
   /
1882
solution to the equations of space charge flow by the method of the
separation of variables  the steady state behaviour of electron beams
with high space charge densities is analysed  the equations for irrotational
electrostatic laminar space charge flow are set up in terms
of the action function these equations are reduced by separation
of variables in cylindrical polar coordinates  the method may be
extended to include the effect of magnetic fields
   /
1883
energy spectrum of plasma electrons  brief report on results obtained
by the graphical method described earlier of
   /
1884
thermal conductivity of an electron gas in a gaseous plasma  experimental
techniques used with ne and he plasmas are described  conductivity
values obtained by two separate methods are in agreement and consistent
with theory
   /
1885
kinetic theory of magnetohydrodynamic waves  analysis of the propagation
of magnetohydrodynamic waves in an ionized gas when the wave frequency
is much greater than the frequency of short range collisions  see
also of
   /
1886
microwave method for measuring the probability of elastic collision
of electrons in a gas  a plasma in a dc magnetic field has a transverse
condductivity component whose reactive part depends on the magnetic
field  by measuring the magnetic field necessary to make the reactive
part zero the probability of the elastic collision of electrons in
he is obtained
   /
1887
scattering of microwave radiation by a plasma column  experiments
conducted by to determine the angular distribution of the em radiation
scattered by the positive column of a mercury discharge under resonant
conditions are described  results support the theory of mackinson
and slade
   /
1888
microwave faraday rotation design and analysis of a bimodal cavity
an equivalent circuit is developed for the cavity and the coupling
between degenerate modes is expressed in terms of the susceptibility
tensor of the material producing the rotation  the results are compared
with experimental data
   /
1889
propagation of plane electromagnetic waves in inhomogeneous media
the laws of propagation along the direction are derived for infinite
inhomogeneous media in which dielectric constant and electrical conductivity
are functions of and the magnetic permeability is constant
homogeneous media are treated as special cases
   /
1890
electromagnetic scattering by thin conducting plates at glancing
incidence  a large signal is scattered back from a thin plate illuminated
edge on by a field whose magnetic vector is normal to the plate
experimental measurements show that the currents in the plate are
predominant near the edges their relation to theoretical results
is discussed
   /
1891
a helical coordinate system and its applications in electromagnetic
theory  the system described enables problems involving helical symmetry
to be solved exactly
   /
1892
the edge condition in diffraction problems  the diffraction of an
em wave by a perfectly conducting solid is considered
   /
1893
theory of wave scattering on periodically uneven surfaces  description
of six approximate mathematical methods for calculating the scattering
of sound or em waves over the sea or uneven ground  references
   /
1894
magnetic double refraction of microwaves in paramagnetics  investigation
at of the rotation of the plane of polarization of an wave in a circular
waveguide containing a paramagnetic salt and its dependence on the
intensity of the static magnetic field perpendicular to the direction
of wave propagation
   /
1895
spin wave analysis of ferromagnetic resonance in polycrystalline
ferrites  dipolar interaction is taken into account by means of the
spin wave formalism  crystalline anisotropy and the polycrystalline
nature of the material cause the homogeneous mode of precession to
interact with spin waves whose wavelength is of the order of or larger
than the average linear grain size  the theory predicts a very strong
frequency and shape dependence of the line width when the homogeneous
mode is approximately degenerate with long wavelength spin waves
propagating normal to the dc field
   /
1896
paramagnetic resonance  the quantum mechanical theory of the phenomenon
is discussed with reference to results of experimental investigations
   /
1897
technical applications of microwave physics  particular reference
is made to electron resonance techniques
   /
1898
paramagnetic resonance spectrum of gadolinium in hydrated lanthanum
trichloride  the paramagnetic resonance spectrum of gd in was measured
and found to agree quite well with a spin hamiltonian with dominant
coefficients at room temperature and at liquid air temperature
   /
1899
theory of plasma resonance in solids  the modes of a confined plasma
are studied for simple geometries  modes are closely spaced in frequency
and unresolvable unless the sample size is comparable to the debye
length  observation in small samples is made difficult by line broadening
due to surface scattering but might be possible in a suitably
designed experiment
   /
1900
fourier coefficients of crystal potentials  a method is developed
for the calculation of the fourier coefficients of the electrostatic
potential of a given distribution of valence electrons in a solid
taking full account of the nonspherical character of the atomic polyhedron
   /
1901
interplanetary magnetic field and its control of cosmic ray variations
a model interplanetary magnetic field is described which may explain
some features of solar cosmic ray increases and also fluctuations
in the primary radiation  an attempt is made to show how localized
solar fields may create the field which should be largely radial
in form
   /
1902
a theorem on force free magnetic fields  a variational principle
is proved which provides a more direct and satisfactory approach
than that given in of chandrasekhar and woltjer
   /
1903
nonuniformity in the brightness of the suns disk at sunspot minimum
a comparison is made between the nonuniformity as derived from ionospheric
measurements during eclipses observed in and  the results suggest
that there are significant differences for the two epochs
   /
1904
observation of a solar flare at wavelength  scans made across the
sun on september with a radio telescope of are compared with corresponding
scans for a quiet sun
   /
1905
solar radiation on decimetre waves as an index for ionospheric studies
the solar noise radiation flux at is compared with other indices
of solar activity  it seems to be as good as any other index for
ionospheric studies on a monthly time scale and better for shorter
time intervals
   /
1906
the trapping of cosmic radio waves beneath the ionosphere  when there
is a horizontal gradient in the critical frequency of a layer incoming
extraterrestrial radiation may be trapped between the layer and the
ground and propagated over large distances  this would account for
the reception of cosmic noise at frequencies lower than the local
critical frequency
   /
1907
sudden cosmic noise absorption associated with the solar event of
march
   /
1908
the relationships between the secular change and the non dipole fields
the drift and decay contributions to the secular variation have been
estimated from isomagnetic and isoporic charts for in canada  the
westward drift in recent years was found to be significantly smaller
than the world wide average  relations are obtained between the gaussian
coefficients in the spherical harmonic analyses of the earths main
field and the secular variation  it is shown that one half of this
variation is produced by westward drift and that the decay terms
are unimportant
   /
1909
electron density profiles in the ionosphere during the igy  see of
february smith rose
   /
1910
use of artificial satellites to explore the earths gravitational
field results for sputnik
   /
1911
seasonal illumination of a circumpolar earth satellite at its extreme
latitude orbit point
   /
1912
polyhedral satellite for more accurate measurement of orbit data
of earth satellites  a face polyhedron would reflect to an observer
a light pulse of intensity more than times that from a sphere
   /
1913
rotation of artificial earth satellites  radio signals received from
sputnik were subject to deep regular fading with a semiperiod of
about probably due to free motion of the satellite about its centroid
these fluctuations were less noticeable in the field strength record
of sputnik  the advantages of a disk shaped satellite and methods
of eliminating rotational effects are discussed
   /
1914
the faraday rotation rate of a satellite radio signal
   /
1915
an irregularity in the atmospheric drag effects on sputniks and satellites
   /
1916
satellite tracking by hf direction finder  a twin channel cr df with
an adcock aerial was used on the signals from satellites and  the
results obtained and their accuracy are discussed
   /
1917
comparison of phase difference and doppler shift measurements for
studying ionospheric fine structure using earth satellites
   /
1918
on the electron production rate in the f region of the ionosphere
the region between bottom and height of maximum density is divided
into four equal columns the mean production rate in each being calculated
the results show a diurnal variation of the rate with a single
peak at about half an hour before noon
   /
1919
drift observations evaluated by the method of similar fades  a regular
interference model is considered as opposed to the usual purely random
model  some of the observed features are well explained by a model
which lies between these two views provided a finite lifetime is
assumed for the irregularities  large changes of drift velocity can
be explained by assuming small vertical velocities
   /
1920
bifurcations in the f region at baguio  a five year statistical survey
of bifurcations at baguio phillipines is presented and it is shown
that the condition for bifurcation is mainly governed by the parameters
and of the f layer depends on latitude whilst depends on solar activity
   /
1921
the diurnal variation of near the auroral zone during magnetic disturbances
   /
1922
horizontal drifts and temperature in the lower part of region e
drift velocities deduced from the fading of cw signals at oblique
incidence are related to results obtained using other techniques
a minimum velocity at km is indicated and a possible connection with
a temperature minimum at the same height is discussed
   /
1923
height gradient of electron loss in the f region  a theoretical expression
is derived for an exponential height gradient of the electron
loss coefficient in the f region on the assumption that this gradient
completely accounts for bifurcation  five models are investigated
they are second power linear cosine parabolic and quasi parabolic
distributions of electron density with height
   /
1924
the electron distribution in the ionosphere over slough part disturbed
days  the results are analysed of the distribution with height for
three months in a year of low and three months in a year of high
sunspot number  it is shown that the variation in is not a quantitative
guide to the changes in height of the layer during storms  the electron
distributions for five individual storms are thoroughly investigated
some important ionospheric changes have been noticed during a world
wide sudden impulse  part of
   /
1925
on instrument effect in ionosphere data
   /
1926
abnormal ionospheric behaviour at metres wavelength  during observations
at hyderabad india of cosmic radio noise total reflection of cosmic
noise was observed on three occasions near sunrise  the effect is
assumed to be caused by a locally high concentration of matter in
the upper ionospheric layers
   /
1927
on the approximate daytime constancy of the absorption of radio waves
in the lower ionosphere  the lower part of the d layer is due to
photo detachment of electrons from negative ions the concentration
of which is large and nearly constant from day to night  the optical
depth is small for the photo detachment radiation but large for the
radiation which can ionize neutral particles
   /
1928
ionospheric absorption over delhi  an analysis of further measurements
made at until october
   /
1929
a new antenna to eliminate ground wave interference in ionospheric
sounding experiments
   /
1930
radio reflections on low frequencies from height during intense aurora
activity
   /
1931
simultaneous recording of atmospherics on four different frequency
bands in the low frequency region  the number and intensity of atmospherics
are recorded simultaneously on four narrow bands at and  results
show atmospherics with large field strengths to be less frequent
than those with small field strengths on all bands and the field
strength of atmospherics to be a maximum in the band
   /
1932
the relationship between atmospheric radio noise and lightning  in
europe atmospherics in a bandwidth of at have median amplitude amplitude
range and frequency occurrence in accordance with that expected from
lightning discharges to the ground  in australia atmospherics from
tropical storms were found to consist of numerous pulses the largest
of which probably originated in ground strokes  the origin of the
smaller pulses is not clear  some observations on atmospherics in
the hf band are also described
   /
1933
waveforms of atmospherics with superimposed pulses recorded with
an automatic atmospherics recorder  the recorder design is briefly
outlined and observations are discussed in which stepped pulses from
one lightning discharge are superimposed on the waveform from a second
discharge  see also of tantry
   /
1934
boosting power transistor efficiency  high efficiency is obtained
by carefully controlling the instantaneous voltage and current through
the transistor
   /
1935
precision current regulator using transistors  a regulator for electromagnets
of field strength between and is described which is accurate
to within two parts in
   /
1936
transistor voltage regulators  design considerations are discussed
for series type regulators and the magnetic amplifier type designed
for the tridac computer is described
   /
1937
an electronic ratio calculator  use is made of the principle that
the amplitude ratio of two signals is approximately linearly related
to the phase angle of the sum
   /
1938
digital analogue conversion with cryotrons
   /
1939
a high speed logic system using magnetic elements and connecting
wire only  square loop magnetic elements having multi aperture or
multipath variations of the toroid shape are used to provide unilateral
information flow properties  information bit rates above have been
obtained with commercial ferrite material  advantages include simplicity
of wiring and the inherent nondestructive read out properties of
the system
   /
1940
automatic data reduction of spot diagram information  the redistribution
of energy falling on a photo cathode during scanning by a mechanical
image dissector is evaluated
   /
1941
measurements of nonlinearity in cracked carbon resistors  frequencies
used were and mcs  resistors measured ranged from w  the degree of
nonlinearity would be negligible for most purposes
   /
1942
millimicrosecond microwave ferrite modulator  description of a switching
device similar to the resonance type isolator described by enander
of but with ferrite rings placed inside the helix and with a single
straight wire along the axis carrying the modulating current
   /
1943
photoelectronic circuit applications  the characteristics of switching
circuits using combinations of electroluminescent cells and photoconductors
are discussed  applications are described in computer operations
where the highest speed is not essential
   /
1944
a temperature stabilized photo transistor relay circuit  a photo
transistor and an ordinary junction transistor are used in a long
tailed pair arrangement to reduce the variation in dark current
   /
1945
a reversible dekatron counter
   /
1946
recent advances in the solid state electrolytic capacitor
   /
1947
design of aperture coupled filters
   /
1948
network synthesis  a method is outlined for the synthesis of balanced
asymmetrical rc networks which may have a lower pad loss than the
corresponding symmetrical types
   /
1949
definition of lossy quadripoles by voltage node displacements in
the microwave range  equations are derived giving the voltage swr
and the position of the voltage node on the input line of a lossy
quadripole in terms of the position of the short circuit on its output
line
   /
1950
determination of transistor performance characteristics at vhf  an
immittance chart a development of the smith chart is described and
its application in the design of adjustable matching networks for
transistor measurements is illustrated
   /
1951
general physical relations in ladder type filters  the improvement
of filter characteristics by mismatch conditions between the ladder
sections is considered and a design method is outlined
   /
1952
minimum insertion loss filters  the generalized criterion for butterworth
and tchebycheff filters of arbitrary bandwidth is chosen for minimum
loss in the centre of the band
   /
1953
the design of two section symmetrical zobel filters for tchebycheff
insertion loss
   /
1954
a voltage controlled continuously variable low pass filter  the filter
has a octave cut off characteristic and the cut off frequency at
is continuously variable from to by a control voltage variation of
v
   /
1955
the exact design of two types of single crystal wide band crystal
filters
   /
1956
the sy metrical transfer characteristics of the narrow bandwidth
four crystal lattice filter
   /
1957
the bifilar t circuit  the circuit is critically examined using lattice
network theory  see also of hendry and mcintosh
   /
1958
the calibration of microwave attenuators by an absolute method  a
bridge method is described and results of measurements at are given
   /
1959
alternatives to the wien bridge  oscillator circuits with two gang
control having higher output voltages and greater selectivity than
the basic wien ridge circuit are described
   /
1960
a wide band voltage controlled swept frequency rc oscillator  oscillators
based on the principle of parallel network tuning are examined
new equipment using this principle is described in detail  frequency
variations can be restricted to any limits in the range and the maximum
duration of the sweep cycle can be varied from to min
   /
1961
incremental frequency control of rc oscillators  an auxiliary phase
shifting network is introduced to provide a continuously variable
incremental frequency control  a practical method is described for
systematically correcting the error which exists for large increments
   /
1962
construction and properties of high quality oscillator crystals
details are given of the shape processing and mounting of crystals
for use in quartz clock standards  the influence of various design
parameters on crystal characteristics and performance is discussed
and a method of frequency control is described  see also of scheibe
et al
   /
1963
a monostable circuit using a transistor  a pulse generating circuit
is described using a simple pulse transformer and a transistor  pulse
duration is adjustable over a wide range greatly exceeding that usually
associated with the pulse transformer used
   /
1964
crystal controlled transistor oscillators  the design of parallel
resonant circuits is considered
   /
1965
the use of dekatrons for pulse distribution  specific methods are
discussed for increasing the number of output lines available from
cold cathode selector tubes used for distributing pulses in a fixed
time sequence
   /
1966
a transistor decade counter
   /
1967
investigations on harmonic frequency dividers to determine the prerequisite
conditions for achieving high division ratios and large locking
ranges at high frequencies
   /
1968
a regenerative modulator frequency divider using transistors
   /
1969
magnetostrictive delay line for video signals
   /
1970
pulse amplifier with submillimicrosecond rise time  the rise time
is about  the dc pulses modulate a carrier and the rf pulses are
amplified by a travelling wave valve  demodulation then gives the
amplified dc pulses  the maximum power gain is and the maximum output
voltage v
   /
1971
a low noise wide band amplifier for the investigation of electron
avalances
   /
1972
low level dc amplifier with whole loop feedback  a vibrating contact
modulator and whole loop negative feedback are used and a stabilized
gain of from dc to is obtained  the zero drift is less than per hour
and less than per day
   /
1973
amplitude and phase response of an amplifier operating on an interrupted
cycle  analysis of class c amplifier characteristics
   /
1974
transistor amplifiers common base versus common emitter  the gain
stability and frequency response of the two circuits are compared
theoretically and experimentally  if a generator with a relatively
low impedance is used these characteristics need be no worse for
the common emitter than for the common base amplifier
   /
1975
transistor bias design from thermal incremental properties  explicit
formulae for design of single stage bias networks are given  two
thermal parameters need to be known  one related to and the other
to the rate of change of input current  applications and experimental
verification of the theory are included  see also of
   /
1976
an introduction to matrices and their use in transistor circuit analysis
brief details are given for analysing both simple and complex
circuits using transistors with emphasis on application to practical
circuits
   /
1977
low noise transistor amplifier stages with negative feedback  theoretical
investigation of the grounded emitter connection with feedback
resistance in the emitter circuit  the relation of source impedance
to optimum noise figure is determined
   /
1978
maser action in the region of k  a three level solid state maser
using a ruby with a cr concentration has given a stable gain of at
   /
1979
a tunable maser amplifier with large bandwidth  the bandwidth is
at gain with a bath temperature of k  the centre frequency is tunable
in the range  operation depends on a phonon saturation mechanism
in a ruby crystal
   /
1980
a chromium corundum paramagnetic amplifier and generator  note on
the operation of a paramagnetic amplifier and generator using a single
crystal of  levels characterized by the quantum numbers when the
crystalline axis is oriented parallel to the constant external magnetic
field are used  absorption lines for different power levels of the
auxiliary radiation are shown
   /
1981
molecular amplifier and generator for submillimetre waves  the rotational
transitions of nh molecules lie in the wavelength region below
mm  an amplifier can be constructed using a device in which radiation
from one horn crosses a number of molecular beams and falls on a
second horn  the maximum power obtainable is about
   /
1982
new method for pumping a fast space charge wave
   /
1983
four terminal parametric amplifier  a lumped constant model using
ge junction diodes at a signal frequency of has a gain of a bandwidth
of and a noise factor of db
   /
1984
microwave parametric amplifier by means of germanium diode  construction
and performance of an amplifier for using gold and silver bonded
ge diodes
   /
1985
the reactatron a low noise semiconductor diode microwave amplifier
two nonlinear capacitor microwave junction diodes are used in a balanced
hybrid  with a pump frequency of about twice the signal frequency
of power gains greater than with a noise figure of were obtained
for a bandwidth of
   /
1986
amplitude modulation of centimetre waves by means of ferroxcube
losses in a ferroxcube rod  caused by a modulating magnetic field
vary the amplitude of a centimetre wave reflected from it  the nature
of the losses and the maximum frequency at which they occur are examined
theoretically  an experimental circuit has been constructed operating
at with a modulation frequency of wide bandwidths are not possible
   /
1987
diode phase detectors  the general case of unequal voltages applied
to simple and balanced push pull phase detectors is studied  curves
for design and evaluation of accuracy are given  the use of a signal
greater than the reference voltage appears to be desirable in some
applications
   /
1988
the use of beam defocusing to provide a microwave detector
   /
1989
stokes equations and their application to the refractivity of thin
films  the problem of determining the microwave optical properties
of n parallel planes of artificial dielectric from the properties
of a single planar array is solved by using an extension of stokes
equations
   /
1990
oscillographic study of rf oscillations in silent electrical discharges
oscillations produced under conditions of light or darkness in iodine
vapour and hydrogen gas in discharge tubes fitted with external sleeve
electrodes are described
   /
1991
certain phenomena observed on coupling an oscillator and a tube of
ionized gas introduced in the oscillator inductance  an experimental
study is reported in which an oscillator coil carrying a current
surrounds an energized gas discharge tube  the effects of the hf
current on the discharge are considered  in particular the luminous
effects and the maintenance of the discharge after the energizing
voltage is removed
   /
1992
a new phenomenon of electron emission from thin mercury films  report
of an experimental investigation of film emission in a specially
designed discharge tube indicating that neither extremely high current
densities nor cathode evaporation are intrinsic requirements for
emission from liquid metal surfaces
   /
1993
spectral distribution of thermal noise in a gas discharge  by means
of thermodynamic considerations it is shown under which conditions
microwave noise power generated by a gas discharge can be considered
thermal  a critical analysis of mumfords hypothesis is made
   /
1994
the statistics of plasma  fundamental dynamic equations are derived
comprising a system of partial differential equations
   /
1995
calculation of fields on plasma ions by collective coordinates
   /
1996
the electrical conductivity of a plasma  the exact theory of electrical
conductivity of a plasma in the presence of a weak electric field
is obtained by the integration of boltzmanns equation for ionized
gases taking account of electron interaction
   /
1997
the structure of strong collision free hydrodynamic waves  a theoretical
study has been made of the structure of strong hydromagnetic waves
which are propagated across a magnetic field in a low density plasma
where collisions can be neglected
   /
1998
oblique shock waves in a plasma with finite conductivity
   /
1999
the fourth reflection condition for electromagnetic waves in a plasma
the introduction of a term generally neglected in applying boltzmanns
equation modifies the expression for refractive index normally used
in magneto ionic theory
   /
2000
coherent spontaneous microwave emission by pulsed resonance excitation
this paper describes an investigation of the coherent microwave emission
from pulse excited ammonia molecules  coherent and periodic pulses
of near resonance frequency and duration excited the gas from its
initial thermal condition  self induced coherent emission molecular
ringing continued after the excitation field was removed  this radiation
was observed during a period of  in an actual experiment performed
a new doppler bandwidth reduction method was used in the gas cell
the observed spectral width of the ammonia line was about  the emission
was used to stabilize the excitation signal source to a short term
frequency stability of
   /
2001
propagation of an electromagnetic field in a medium with spatial
dispersion  investigation of the propagation of a transverse wave
along a magnetic field in a plasma taking account of the thermal
motion of electrons  strong absorption occurs in the region at which
cherenkov radiation is possible
   /
2002
on the diffraction and reflection of waves and pulses by wedges and
corners  various problems arising in the theory of the excitation
of a perfectly reflecting wedge or corner by a plane cylindrical
or spherical wave are dealt with  the incident wave is represented
by a line source acoustic or electromagnetic parallel to the edge
the spherical wave is emitted by an acoustic point source or by a
hertz dipole with its axis parallel to the edge  the case of an incident
plane wave field is obtained as the limiting case for large distances
of the source from the edge of the cylindrical or spherical wave
excitation
   /
2003
the diffraction of an electromagnetic plane wave by a perfectly conducting
half plane  electromagnetic waves in isotropic and crystalline
media characterized by permittivity with spatial dispersion  the
necessity of taking account of spatial dispersion in non gyrotropic
media in relation to the permittivity tensor and also in the analysis
of longitudinal plasma waves propagating in an isotropic medium or
along the principal dielectric axes in crystals is stressed  collrvyive
energy losses and the cherenkov effect are also considered
   /
2004
attempt to interpret the shape of paramagnetic resonance signals
by the introduction of a high frequency demagnetizing field  the
theory accounts for the asymmetry of the resonance curve of organic
radicals such as diphenyl picryl hydrazyl at
   /
2005
microwave physics  discussion of resonance techniques particularly
as applied for microwave amplification with reference to three papers
read at the british association meeting held in glasgow september
   /
2006
comparison of the sensitivities of paramagnetic electron resonance
spectrographs in the band  modification of the coupling between a
waveguide and a cavity is discussed for the following cases negligible
background noise signal intensity of the same order as background
noise
   /
2007
the elastic model of lattice defects  it is showastic continuum there
is a repulsive interaction if the spheres are bonded to the medium
the effect of other boundary conditions is discussed and a simplified
method is given for calculating the interaction between various types
of defect
   /
2008
energy states of a one dimensional crystal with vacant lattice sites
   /
2009
relations between the concentrations of imperfections in solids
imperfections haeing opposite effective charges tend to increase
each others concentrations  foreign atoms are incorporated in a manner
dependent both on energy levels caused by them and on the type of
imperfection prevailing in the crystal in their absence
   /
2010
on a feature of galactic radio emission  observations of the intensity
distribution of radio emission have shown a bright belt approximately
normal to the galactic plane and passing through the the anti centre
an explanation is suggested in terms of the highly anisotropic radiation
from relativistic electrons moving in the magnetic field of the local
spiral arm  this suggestion avoids the supposition that the sun is
in a special position in the galaxy
   /
2011
a phase sensitive interferometer technique for the measurement of
the fourier transforms of spatial brightness distributions of small
angular extent  the rf interferometer described consists of three
aerial systems tuned to
   /
2012
on the power spectrum of solar radio outburst and its relation to
swf dellinger phenomenon and geomagnetic storm  solar radio outbursts
are classified according to their power spectra  those with power
spectra increasing towards lower frequencies are associated with
magnetic storms but not with sids while those with spectra increasing
towards higher frequencies are associated with sids without an accompanying
magnetic storm  outbursts with flat power spectra appear to
combine the attributes of the other two types
   /
2013
the possibility of forecasting solar phenomena and their terrestrial
repercussions by the study of the intensity of cosmic radiation
an analysis of observations made from april to march shows that a
decrease in cosmic ray intensity of occurs before chromospheric eruptions
which are followed by intense geomagnetic and ionospheric disturbances
this decrease also precedes or coincides with an increase in
solar rf noise  see also
   /
2014
discrimination between chromospheric eruptions associated with geomagnetic
disturbances during the present solar maximum  an analysis of
observations from april to march shows that some but not all solar
flares are accompanied by a marked increase of rf noise at about
mcs
   /
2015
a simple method of detecting solar flare effects in the lower ionosphere
field strength records of transmitters operating at frequencies
over a distance of provide a sensitive means of detecting and identifying
solar flare effects
   /
2016
intensities polarization and electron density of the solar corona
from photographs taken at the total solar eclipse of february
   /
2017
sudden commencements of magnetic storms at tamanrasset  an analysis
of observations made at tamanrasset from to inclusive
   /
2018
scale height of the upper atmosphere  the effect of air drag on the
orbit of an earth satellite is calculated allowing for the ellipticity
of the earth
   /
2019
sputnik as a tool for securing geodetic information
   /
2020
a possible cause of air resistance changes in satellite orbits  the
variation in the extent of the atmosphere in accordance with geomagnetic
activity particularly in the auroral zones is suggested as a possible
cause of observed changes in satellite orbital period
   /
2021
the rotation of the first russian earth satellite  fading records
obtained during transits over cambridge at about ut october have
been examined  the records show a discontinuous change in fading
rate at the time of nearest approach  this is attributed to changes
in polarization in certain aspects of the satellite relative to the
observer caused by the generation of a cone by the rotating aerial
it is concluded that the satellite rotated at rev min generating
a cone of semi angle the direction of the rotating axis being at
to the direction of the arbit at perigee
   /
2022
determination of the orbit of an artificial satellite  theory of
a method depending on doppler measurements at four stations  no initial
assumptions about the orbit are required
   /
2023
a new method of tracking artificial earth satellites  a photoelectric
method of optical tracking has been developed which appears to have
a precision comparable with astronomical observations  a record of
observations of the rocket of sputnik on july at tatsfield surrey
is shown
   /
2024
tracking orbits of man made moons  description of the minitrack interferometer
type system designed to measure satellite position to an
accuracy within seconds of arc with a time precision of one millisecond
   /
2025
doppler satellite measurements  a note on records obtained during
successful and unsuccessful launchings
   /
2026
further radio observations on artificial satellites  report on data
obtained in florence italy from radio observations of satellites
and
   /
2027
signal strength recordings of the satellite sputnik at college alaska
   /
2028
world data centre for rockets and satellites slough  it was agreed
at the recent moscow meeting of the special committee for the igy
to accept a british offer of a third centre where data from british
investigations would be collected and exchanged with the centres
in washington and moscow
   /
2029
radiosonde measurement of vertical electric field and polar conductivity
a field mill and a gerdian type conductivity apparatus are described
for use with a modified kew mk radiosonde  these are used for measuring
the electrical properties of the lower atmosphere and clouds
   /
2030
on the semi diurnal lunar variations in the critical frequency semithickness
and height of maximum ionization of the f layer in the daytime
results obtained for show reasonable agreement with those of other
workers but contradict a theory of f layer formation previously postulated
of january yonezawa  results for other parameters are doubtful
owing to statistical errors but appear to be exactly opposite in
phase to those of other workers
   /
2031
back scatter ionospheric sounding experiments  report on tests at
made near rome from august to october  large discrepancies are found
with results derived from vertical soundings  subsequent tests are
proceeding at and
   /
2032
ionospheric drift measurements in the long wave range as a contribution
to the problem of general circulation of the upper atmosphere  spaced
receiver measurements at of ionospheric drift at altitude indicate
distinct seasonal reversals in the circulation of the upper atmosphere
small diurnal variations are superimposed on the normal drifts and
an additional ns component is observed during magnetic storms
   /
2033
ionosphere review  solar activity f layer ionization and ionospheric
and magnetic disturbances were less than those recorded in
   /
2034
the ionosphere  a translation of the original ferman book see of
   /
2035
atmospheric electricity  enlarged and revised edition of an earlier
work see of
   /
2036
electronic magnetic field stabilizer with feedback  fluctuations
in the magnetizing current of an electromagnet are integrated using
a vibrator amplifier in a circuit with a time constant of ms and
the derived signal energizes a compensating coil
   /
2037
the effect of radiation on silicon solar energy converters  the solar
cells are unaffected by irradiation with ultraviolet light and x
rays  high energy electrons protons and particles produce a time
decay in such characteristics as maximum power output open circuit
voltage and short circuit current  the lifetime of the cells to of
the initial power output is estimated to be years when exposed to
the radiations assumed to exist at earth satellite orbit heights
   /
2038
forward current surge failure in semiconductor rectifiers  a semiconductor
current limiter  a constant current device is described which
uses the field effect at a junction  the reverse bias applied controls
the conductance of a thin sheet of semiconductor  various models
and a particular design are discussed and some applications to switching
and waveform generation are given
   /
2039
compensation for fluctuations in the anode current of a valve due
to heating  in the method described an antiphase rectified voltage
proportional to heater current variations is applied to the control
grid of the valve to stabilize the anode current
   /
2040
digital techniques for small computations  a special digital method
of computing simple algebraic functions with one to four variables
is described and analysed  the method is particularly suited to division
and root extraction
   /
2041
automatic failure recovery in a digital data processing system  a
program is described which automatically compensates for computer
malfunctions so that recovery from errors may be effected with a
negligible loss of operational time
   /
2042
representations grouping and processing of information in automatic
data processing
   /
2043
a sensing system for punched cards or continuous punched foil
   /
2044
logic synthesis of some high speed digital comparators  logical schemes
are derived by boolean algebra methods  circuits satisfying the synthesis
requirements and giving either exact or approximate proportional
comparison are described
   /
2045
function generator for sines or cosines  operation of the transistorized
unit described is based on the fact that the area under a sine curve
varies as a cosine function  basic components required are a linear
pulse width modulator an ideal switch two pnp transistors connected
emitter to emitter an integrator and a sine wave source
   /
2046
an analogue multiplier divider using thyrites  a new analytical method
is proposed for determining quadratic elements using thyrite resistors
a description is given of a new multiplier with thyrite units which
requires only two operational amplifiers  experimental results are
given
   /
2047
logic for a digital servo system  a cr tube beam in a photographic
storage system is positioned by comparing a binary address with a
digital indication of the present position  digital servo logic circuitry
is described for obtaining the sign and magnitude of the positional
error
   /
2048
an electron analyser of contact circuits  a description is given
of an apparatus for rapid determination of possible combinations
in the operation of a circuit comprising six relays  one of the possible
uses of the apparatus is the simplification of the existing circuits
by removing the unnecessary contacts
   /
2049
the multipurpose bias device part the efficiency of logical elements
the efficiency of a logical element can be equated with the set of
subfunctions it realizes upon biasing or duplication of inputs  various
classes of elements are considered and optimum or near optimum examples
are presented  some related areas of study are suggested  part of
   /
2050
millimicrosecond magnetic gating and storage element  the element
consists of a round glass rod which is first chemically plated with
a silver conductor and then electroplated with an fe ni film  the
element has an almost square saturation loop
   /
2051
the laddic a magnetic device for performing logic  the laddic is
a ladder like structure cut from rectangular hysteresis loop ferrite
all magnetic paths are flux limited  by controlling the actual switching
path any boolean function of n variables can be produced
   /
2052
tape recording system speeds data processing  a pwm tape recording
system is described with a capacity of digits  the tape is in wide
and carries channels  the transport mechanism is electronically controlled
and can start stop and reverse within a few milliseconds
   /
2053
an analogue computer for evaluating radar performance  describes
briefly the basic design of an analogue computer developed to evaluate
the statistical information needed to assess radar tracking performance
   /
2054
application of analogue calculation to flight simulators  computer
elements for simulating the reactions resulting from the effects
of gyration pitch and roll are described
   /
2055
the transformer as a two terminal network  the equivalent two terminal
networks are derived for various types of transformer
   /
2056
on hybrid transformers  design formulae are derived from basic assumptions
and the properties and some common uses of these circuit elements
are discussed
   /
2057
premagnetization of the core of a pulse transformer by means of ferroxdure
premagnetization to improve the loading of the core of a transformer
carrying unidirectional pulse currents is examined theoretically
a practical transformer is described
   /
2058
high power transistor dc converters  circuits are considered for
dc dc or dc ac converters using ge and si power transistors which
can give power outputs of up to w
   /
2059
saturable transformer switches  a switch using cores in a balanced
saturable transformer is considered  an on off impedance ratio adequate
for switching magnetic recording heads for reading and writing operations
can be obtained  circuits are described for operation of a matrix
selection system with a switching time of a few tens of microseconds
   /
2060
ferroelectrics tune electronic circuits  circuits are described in
which carying bias is used to change the capacitance of ferroelectric
capacitors used as tuning elements
   /
2061
direct voltage instantaneous breakdown of oil impregnated paper capacitors
as a function of area  the experimental results given show that
the variation of mean breakdown voltage with increasing area is represented
adequately by milnors equation  the coefficient of variation
appears to be independent of area but decreases with increasing thickness
of dielectric
   /
2062
a comparison of wool wax and petroleum jelly as impregnants for paper
capacitors  results given show that wool wax impregnants give about
higher capacitance without any serious loss in performance
   /
2063
the equivalent circuit of oscillating piezoelectric crystal rods
formulae are derived for calculating the circuit parameters for longitudinal
torsional and flexural oscillations taking account of internal
damping and the air gap between electrodes and crystal
   /
2064
voltage and current controlled negative resistance two poles  the
mechanism of voltage and current control in two pole networks is
discussed  equations for obtaining the equivalent circuits from direct
measurements at the network terminals are given
   /
2065
the geometrically simplest form of representation of the general
lossy quadripole  the transformation discussed is based on a construction
of four planes perpendicular to each other in pairs in a non euclidean
system  it can be represented in a drawing by stereographic projection
   /
2066
coupling coefficients of ladder networks with maximally flat amplitude
response  the coefficients are expressed in terms of the dissipations
in the input and output branches using a generalized theory of greens
method of solution
   /
2067
hf wide band electronic integrator design  compensation for distortion
of the integrated waveform due to valve output capacitances can be
introduced by the addition of a capacitor in parallel with the integrating
network resistance  an exprression is derived for calculating
the capacitance for the basic rc integrator and the miller integrator
   /
2068
impedance converters  the quadripole relations and equivalent circuits
of negative impedance converters are summarized and applied to practical
unbalanced converter circuits with valves and transistors
   /
2069
a laguerre function equalizer  a waveform corrector is described
in which the input signal is successively differentiated and the
differentials added to or subtracted from the input the waveforms
being given by laguerre functions  results are given for an experimental
equalizer which need contain only passive elements
   /
2070
constant frequency oscillators without stabilized voltage supplies
four valve oscillators controlled by thermistor bridge circuits are
described
   /
2071
the design of crystal controlled three terminal valve oscillators
design formulae for the pierce miller and pierce colpitts circuits
are derived taking account of the effect of crystal resistance on
frequency
   /
2072
stable low cost oscillator  description of a crystal controlled transistorized
oscillator with frequency stability within part in per day
at normal room temperatures  total weight of oven and oscillator
is
   /
2073
frequency stepper for radio propagation tests  full circuit details
are given of a stepped frequency exciter unit controlling a pulse
transmitter and receiver at widely separated locations  the range
is covered in steps at sec intervals  and crystals are used as reference
frequency sources and frequency control is achieved by means of a
beam deflection tube  transmitter and receiver circuits are briefly
described the transmitter radiates pulses with repetition frequency
or and output power
   /
2074
a barkhausen kurz oscillator at centimetre wavelengths
   /
2075
dual cavity microwave discriminator  intended for stabilizing reference
klystron oscillators used in doppler shift radar systems  tuning
range is thermal drift part in per and discriminator sensitivity
per
   /
2076
the generation of extremely steep pulse edges in multistage nonlinear
amplifiers  the pulse generator described incorporates three transformer
coupled amplifier stages for sharpening the multivibrator pulses
it can supply pulses with a rise time into a load
   /
2077
transistorized fm oscillator
   /
2078
the amplification of very wide frequency bands  various techniques
for amplification in bandwidths exceeding are discussed and the suitability
of cascade and distributed amplifiers is investigated  direct
and indirect methods of delay line equalization are outlined and
details are given of a seven stage distributed amplifier with gain
over a band
   /
2079
wide band amplifier design data  design data are tabulated for three
basic types of coupling  rc shunt peaked and series peaked  gain
is calculated using a series of approximations taking account of
the gain reduction factor for a number of stages
   /
2080
extended range distributed amplifier design  a distributed amplifier
employing a straight wire transmission line is described  the amplifier
has a gain of db from to and input and output impedances of  detailed
electrical and mechanical design considerations are included
   /
2081
an inexpensive ultralinear output stage  a circuit is described which
uses two cathode followers in place of a tapped output transformer
   /
2082
operational amplifier without a stabilized power supply  a new operational
amplifier is proposed in which two parallel circuits for low
and high frequencies are used with a summing amplifier and two feedback
circuits  the theory of the amplifier is discussed and some experimental
results are given  for a mains voltage variation of the output voltage
of the amplifier varies by with a drift rate of sec
   /
2083
on the theory of a half wave magnetic amplifier  a detailed theoretical
analysis is given of an amplifier proposed by ramey see and of experimental
results confirm the theoretical conclusions
   /
2084
differential amplifier features dc stability  drift in transistorized
amplifiers is analysed and circuits for reducing drift are described
for a particular amplifier  a h test showed the equivalent input
drift to be less than from to c
   /
2085
nomographs for designing transistor narrow band amplifiers
   /
2086
transistor amplifiers for dc signals  basic direct coupled and chopper
type amplifiers are examined and compared
   /
2087
a low noise transistor amplifier for acoustic measurements  the portable
equipment described has a gain of about and a frequency range of
with noise output above the theoretical minimum
   /
2088
the maser a new form of microwave oscillator  a short review of the
principles of operation of molecular beam and solid state masers
   /
2089
small signal analysis of molecular beam masers  a perturbation calculation
gives the resonance polarization of a molecule in an electric
field as a function of time  an analysis is then made of maser operation
with a divergent univelocity beam
   /
2090
three level solid state maser  the maximum values of the real and
imaginary components of the paramagnetic susceptibility of a three
level solid state maser are calculated  general expression for the
gain and bandwidth of a travelling wave maser are given
   /
2091
low noise in solid state parametric amplifiers at microwave frequencies
the principles of parametric amplification are described through
the use of simple low frequency electrical circuits and their mechanical
analogues  extension of these principles to low noise amplification
at microwave frequencies is made in a qualitative way which emphasizes
the physical processes involved  amplification is only achieved when
energy is transferred from a microwave oscillator or pump to the
signal frequency and it is shown why such a transfer may take place
in circuits exhibiting variable capacitance or inductance but not
in circuits where only a resistance is varied  major noise sources
are discussed and the special role of the image or idler frequency
is noted  finally experimental data on four different types of parametric
amplifier using semiconductor diodes and using ferrite are given
   /
2092
calculation of harmonic distortion in sinusoidal frequency modulation
cases of a waveguide of any cross section and an amplification stage
with a tuned transformer
   /
2093
potential of an electrostatic field and trajectories of charged particles
a procedure is described for calculating the electric potential
in the path of a charged particle
   /
2094
solutions for the static junction  discussion of certain classes of
solution of the nonlinear differential equation for the potential
distribution near a pn junction  an inverse series solution is developed
which is appropriate for diverse impurity distribution
   /
2095
a new method for the evaluation of electric conductivity in metals
a method is developed for evaluating the closed formal expressions
for electrical conductivity which have recently been developed  see
eg of and of greenwood
   /
2096
secondary positive ion emission from metal surfaces  secondary positive
ions ejected from surfaces of mo ta and pt under bombardment by inert
gas ions of low energy have been studied in high vacuum using a mass
spectrometer with a radius of curvature and a sector field
   /
2097
current voltage behaviour in a plasma  an exact solution for the
current voltage relation in a planar diode filled with a uniform
plasma
   /
2098
electron recombination and negative bands in afterglowing active
nitrogen  the emission of negative bands in the auroral afterglow
of nitrogen is interpreted as being due to excitation of molecular
ions this is supported by recent measurements of the decay of light
intensity of these bands
   /
2099
a note on the confinement of a plasma by rf fields  a rigorous derivation
of certain results previously obtained by boot et al  by inferior
methods
   /
2100
microwave emission from high temperature plasmas  energy losses from
cyclotron radiation are concluded to be negligible for plasma temperatures
less than and probably for those greater than  emission at the
fundamental frequency and first few harmonics is detectable and measurement
of the relative intensities offers a means of determining the
plasma temperature
   /
2101
excitation of oscillations in a plasma layer  development of a linearized
theory of plasma oscillations excited by an electron beam injected
into a uniform plasma
   /
2102
laws of magnetism and of static electricity in any given frame of
reference  a study of maxwells equations in terms of the general
theory of relativity is made as a preliminary to attempting to solve
practical electrical problems
   /
2103
on the diffraction of electromagnetic waves at infinitely thin ideally
conducting flat screens  a new method is described based on the solution
of two independent equations  as an example the case of diffraction
of a wave at an infinitely thin conducting disk is discussed
   /
2104
electromagnetic diffraction by dielectric strips
   /
2105
the analytical study of scattering by thin dielectric rings
   /
2106
a statistical model for forward scattering of waves off a rough surface
   /
2107
light scattering by small particles
   /
2108
propagation of electromagnetic waves radio location and radio astronomy
   /
2109
ionization of the upper atmosphere by low energy charged particles
from a solar flare  discussion of recordings made at thule greenland
and barrow and college alaska of cosmic noise absorption at at the
time of a class solar flare on july
   /
2110
radio observations of the planet jupiter  details are given of observations
outlined previously together with unpublished information from
earlier observations in june  correlation of the observations with
rotation polarization and frequency characteristics is discussed
most of the radio noise bursts were strongly circularly polarized
and the spectrum does not appear to be continuous over the frequencies
observed  critical reflections by an ionosphere around jupiter are
discounted
   /
2111
cosmic ray intensity variations during two solar cycles  from ionization
chamber data the decrease of cosmic ray intensity from its maxima
near sunspot minima is shown to lag a year or more behind the increase
of solar activity following sunspot minima the variability of daily
mean values was particularly great in
   /
2112
cosmic rays in the earths magnetic field  discrepancies between centre
dipole predictions using the stormer equation and experimental observations
of cosmic ray intensities and cut off phenomena are attributed
to differences between the earths real field and the dipole approximation
to it rather than to distortion of the earths outer magnetic field
by ionized interplanetary matter  an empirical expression for the
cut off phenomena is deduced which is in good agreement with experimental
results over a wide range of latitude and longitude
   /
2113
comparison of measured and computed values of the rapid fading rate
of ultra high frequency signals reflected from the moon  observations
made in august during a bistatic moon reflection experiment carried
out at are reported  they show good agreement with values calculated
from the effective libration rate of the moon
   /
2114
meteors in the ionosphere  the nature of radio reflections from the
trails of ionization produced by meteors is reviewed and the principal
uses of meteors as research tools are described  some further directions
in which meteor research may be pursued are suggested
   /
2115
concerning bookers theory of meteoric reflections  the assumption
of small scale ionospheric turbulence see of conflicts with many
known facts about meteor echoes such as the persistence of aspect
sensitivity for as long as ten seconds and the known variation with
time of the angular correlation function
   /
2116
electromagnetic scattering by low density meteor trails
   /
2117
the zurich sunspot number and its variations for  monthly and auroral
mean values of relative sunspot number are tabulated for  estimates
of annual values by wolf for the period are also given together with
derived data
   /
2118
radiation and particle precipitation upon the earth from solar flares
a brief survey in which the energies of these emissions are estimated
and their effects on the ionosphere discussed
   /
2119
centenary of melbourne toolangi magnetic observatory  brief history
of the observatory since
   /
2120
possible causes of geomagnetic fluctuations having a six second period
the fluctuations described by duffus et al may be due to small oscillations
of the earths crust microseisms or more probably atmospheric
oscillations with the same period microbaroms
   /
2121
the diurnal variation of irregular geomagnetic fluctuations part
using the eight daily k numbers three hour range indices for six
observatories in moderately low latitudes and fairly well distributed
in longitude a universal time component of the daily variation of
irregular geomagnetic fluctuations having an apparently significant
amplitude in the yearly average has been found in the data for the
nine years  it is suggested that a portion of magnetic disturbance
may be produced by dynamo action in the ionosphere and give rise
to this yearly average universal time component  for part see of
   /
2122
lunar geomagnetic tides at kodaikanal  tschus method has been applied
to the calculation of the lunar semi diurnal variation of the horizontal
intensity of the earths magnetic field at kodaikanal  the solar diurnal
variation is also determined
   /
2123
time constants in the geomagnetic storm effect  an estimate is made
of the delay between formation of a ring current round the earth
and the occurrence of a geomagnetic storm at ground level  parker
has estimated the delay as several months but by taking proper account
of the fluidity of the medium and the presence of the main geomagnetic
field the delay is found to be small enough to be consonant with
the ring current theory of geomagnetic storms
   /
2124
inadequacy of ring current theory for the main phase of a geomagnetic
storm  there appears to be insufficient dissipation to allow significant
diffusion during a magnetic storm of the magnetic fields in the vicinity
of the earth  a ring current field can therefore only increase the
horizontal component of the geomagnetic field and cannot account
for the main phase of a geomagnetic storm
   /
2125
studies on geomagnetic storm in relation to geomagnetic pulsation
for the recurring geomagnetic storm m type the cone of avoidance
model of pecker and roberts of is supported by both geomagnetic and
cosmic ray data  for the sporadically occurring storm s type a shock
front in interplanetary space may be responsible for the sudden commencement
an exhaustive study should be made to determine whether the
sudden commencement is only associated with the s type  the storm
time variation of the geomagnetic pulsation should also be measured
during world wide storms to aid the study of the shock wave
   /
2126
the international geophysical year  the organization which made possible
the large international cooperative research effort is described
and arrangements for collecting and storing the observational data
are outlined
   /
2127
the day to day coordination of igy observations  in addition to regular
observational programs the igy included special series of observations
made during outstanding solar and geophysical events  the organization
of these series and the necessary ancillary communication facilities
are described briefly
   /
2128
the earth and its environment  a general outline of the many fields
of investigation included in the igy program of observations  particular
attention is given to the earths atmosphere and the flow of heat
through it from the hot interplanetary gas
   /
2129
motion of a satellite around an unsymmetrical central body  if a
central body does not have an inversion centre the eccentricity of
a satellite orbit varies periodically with low frequency and large
amplitude  details are worked out for a central body composed of
a large spherical mass and a small point mass contained somewhere
within it
   /
2130
change of inclination of a satellite orbit  comment on of march
   /
2131
irregularities of satellite drag and diurnal variations in density
of the air  the theory is applied to satellites and
   /
2132
moon rocket tracking  a interferometer situated at lasham hampshire
was used to track the third american moon rocket on november  a satisfactory
record was obtained from to gmt
   /
2133
progress of the russian earth satellite sputnik  orbital data based
chiefly on optical observations are given for the instrument carrying
vehicle and its rocket
   /
2134
the explorers  extracts from a paper presented at the congress of
the international astronautical federation amsterdam  details are
given of the rocket firing procedure and satellite instrumentation
as well as the tracking system used during the launching of the explorer
satellites
   /
2135
instrumenting the explorer i satellite  a description is given of
the phm and mw am transistorized transmitters operating on and respectively
total power consumption was obtained from four mercury type
cells  information was transmitted on skin temperature nose cone
temperature meteorite counts and impacts and cosmic rays  details
are also given of the test program for the completed apparatus
   /
2136
earth satellite observations of the ionosphere  the various methods
of deriving integrated electron content below a satellite are critically
reviewed  although the methods are theoretically capable of giving
information of the diurnal seasonal and latitude variations of content
interpretation of the measurements is difficult because of all these
variations are present simultaneously hence some assumptions about
one or two of the variables must be made in order that the third
one may be studied
   /
2137
investigation of the ionosphere using signals from earth satellites
possible effects of the ionosphere on radio signals from artificial
earth satellites are discussed with reference to theoretical results
noted earlier of
   /
2138
exploration of the upper atmosphere with the help of the third soviet
sputnik  the instruments carried are described and some of the preliminary
results of observations are given  up to km the principal ionospheric
constituent is nitric oxide above this height ions of atomic oxygen
and nitrogen become more important  electron density falls off slowly
above the f region maximum  positive ion density at a height of km
is about ie about half the corresponding electron density  the number
of collisions with micrometeorites at heights of km is
   /
2139
the constitution and composition of the upper atmosphere  a survey
of the observational data and the theoretical problems involved
dissociation of molecular o and n diffusion in the thermosphere and
the conduction of heat through the atmosphere are discussed
   /
2140
the distribution of electrons in the ionosphere  the methods of deriving
profiles are reviewed with particular emphasis on those which include
the effects of the earths magnetic field  attention is drawn to the
use of the extraordinary ray for estimating the electron density
below the peak of the e layer  some results are given of typical
diurnal seasonal solar cycle and latitude variations in the electron
density distribution  references
   /
2141
the normal d region of the ionosphere  a discussion of low frequency
sounding of the lower ionosphere indicating the radio transmission
characteristics to be satisfied  it is suggested the recent measurements
of parameters such as reaction rates will provide an improved model
of the d layer
   /
2142
the normal e region of the ionosphere  an outline of the structure
and behaviour of the e layer with particular emphasis on how it differs
from an ideal chapman layer  the normal f region of the ionosphere
a review which includes comments on the physical conditions of the
layer as determined from rocket and satellite observations bradburys
hypothesis spread f and radio star scintillations
   /
2143
motions in the ionosphere  the theoretical factors involved in the
interpretation of observational data are discussed  particular attention
is given to tidal motions and the need for theoretical advances in
studies of drifts scintillations auroral forms turbulence and large
scale travelling disturbances
   /
2144
horizontal drift measurements in the ionosphere near the equator
drift of the e and f layers has been measured regularly at ibadan
nigeria by the spaced receiver method  the westward daytime drift
velocity in the f layer is about
   /
2145
the interpretation of night time low frequency ionograms  two types
of retardation of the extraordinary ray on passing through a region
whose frequency is below the gyro frequency are discussed  one is
observed near the critical frequency of the ordinary ray and the
other near the gyro frequency  information about the total number
and distribution of electrons below the f layer can be deduced from
them
   /
2146
rocket observations of the ionosphere  a review of the electron density
profiles obtained at fort churchill and at white sands  a comparison
of similar data obtained in russia up to km is made  the effects
of polar blackouts and of flares are discussed with particular reference
to the nature of the solar ionizing radiation  comments are also
made on the radiation which can be detected at night interplanetary
hydrogen and the electron density in interplanetary space
   /
2147
summer day auroral atmospheric structure measurements from to kilometres
density and pressure determined during a rocket flight at cst
july at manitoba canada are compared with earlier measurements
   /
2148
polar e  published ionosonde data are analysed over the period and
show three distinct types of e for northern polar stations each type
occurring in a particular geomagnetic zone  a strong correlation
between e and magnetic activity existing along the auroral belt points
to the influence of corpuscular radiation
   /
2149
abnormal ionization in the lower ionosphere associated with cosmic
ray flux enhancements  two separate abnormalities in ionization were
recognizable during the great solar event of february the early effects
observed at the time of the sudden cosmic ray enhancement and the
late effects which reached a maximum an appreciable time later  a
difference in composition between streams of solar particles of cosmic
ray energies and ordinary cosmic rays is postulated to explain the
former effect while the latter is explained in terms of ionization
at heights of km produced by the passage or stopping of solar particles
predominantly protons  the absence of auroral and magnetic effects
is consistent with these explanations  a provisional evaluation is
also made of the coefficient of collisional attachment of electrons
from negative ions and the negative ion electron ratio and effective
recombination coefficient at night between and km
   /
2150
the f region during magnetic storms  magnetic storms are investigated
using the variation of and over a wide range of latitude  it is shown
that ionization drift theory in association with the dynamo theory
is satisfactory in explaining the observed variations
   /
2151
automatic sweep frequency ionosphere recorder model c  a description
of an improved equipment for use during the igy  in addition to the
virtual height frequency records time lapse motion pictures are taken
   /
2152
the igy three frequency back scatter sounder  the equipment consists
of three transmitters operating at and each coupled to its own horizontal
yagi aerial on a single rotating pole and by a tr switch to a
receiver whose tuning is interlocked with the transmitter  a camera
records the plan position displays for the three frequencies together
with a short range display preliminary results from stations in polar
temperate and equatorial regions are discussed  phenomena reported
include sporadic e movements tilted f layer propagation large irregularities
in the f layer and echoes from field aligned ionization
   /
2153
the riometer a device for the continuous measurement of ionospheric
absorption  a description of an instrument for the measurement of
ionospheric absorption at high latitudes during the igy using the
cosmic noise method see of  the circuit details of this self balancing
equipment are given and its advantages over the system of total power
measurement are discussed
   /
2154
the night airglow  a phenomenological description of the night airglow
is presented reviewing the historical background and what is known
about height temporal and spatial variations in intensity and movements
the very important relationship to aurora and evidence for latitude
seasonal effects are examined
   /
2155
auroral phenomena  present knowledge of the formation of the aurora
is summarized  mechanisms of particle acceleration are considered
and it is emphasized that there is no consistent theory of auroral
phenomena  references
   /
2156
a man made or artificial aurora  an auroral dispplay with which were
associated radio fade outs and a magnetic storm was observed at apia
on august  these phenomena were probably due to the explosion of
a nuclear bomb over johnston island on the same date
   /
2157
auroral ionization and magnetic disturbances  the literature on radio
studies of the aurora the relation between aurora and magnetic storms
and the movements of the ionosphere and auroral forms is co ordinated
references  an average density of electrons cm is sufficient to explain
normal radar echoes  magnetic disturbances are closely related to
ionization and luminosity of the aurora  magnetic variations are
also associated with increases in the speeds of motion of the ionization
   /
2158
radio echoes from auroral ionization detected at relatively low geomagnetic
latitudes
   /
2159
the geometry of auroral communications  uhf auroral radar observations
describes auroral doppler spectra obtained at ottawa with bistatic
radars operating at and mcs  klystron amplifiers with and parabolic
reflectors were used with transmitter receiver separations of and
km  echoes indicating cross sections of several thousand square metres
were obtained on occasions at
   /
2160
a low power vhf radar for auroral research
   /
2161
the very low frequency emissions generated in the earths exosphere
types of noise other than whistlers have been examined using high
resolution spectrograms which show the frequency distribution as
a function of time  most of these noises are excited in the exosphere
by streams or bunches of high speed ionized particles trapped in
the earths magnetic field  the excitation mechanism is similar to
that of a travelling wave valve  most of the observations required
that particle velocities be about kms  a model in which the ratio
of electron density to magnetic field strength is almost constant
along a line of force in the exosphere seems to be indicated by several
types of noise
   /
2162
atmospheric whistlers  the historical background of the discovery
of whistlers and the development of an adequate theoretical explanation
of their behaviour are reviewed  the program of study during the
igy is described and some examples of results obtained are presented
and discussed
   /
2163
path combinations in whistler echoes  a note describing groups of
whistler echoes recorded at unalaska geomagnetic latitude and explaining
them in terms of a combination of alternative propagation paths and
multiple trips over each path
   /
2164
a note on whistler propagation in regions of very low electron density
calculations made on a model ionosphere indicate that nose whistlers
may exist although attenuation may prevent their observation
   /
2165
a sudden enhancement of atmospherics anomaly  on may two anomalous
solar flares caused a sharp drop in the signal level recorded at
pittsburgh pa instead of the usual enhancement  enhancements were
recorded elsewhere
   /
2166
study of the atmospheric radio noise at and at delhi  preliminary
survey of observations extending over a year with particular reference
to sudden enhancement effects
   /
2167
a simple temperature control system for transistors  a description
of a closed loop servomechanism in which a power transistor which
supplies the current for a heating coil is controlled by an error
signal produced by a temperature sensing af transistor
   /
2168
loop controls scatter power to offset fading  a closed loop servo
system is described where by the transmitted power of an uhf tropospheric
scatter link is reduced under conditions of good reception and
increased under fading conditions  a statistical analysis of the
system is given
   /
2169
converting recorders to rectilinear outputs  a computer circuit generating
variable transport time delays is described for transforming
pen recordings from arcs to straight lines  see also of massa and
massa
   /
2170
stabilized variable frequency ac instrument calibration source  a
network is described which renders a amplifier insensitive to variations
of signal input power supply and load
   /
2171
high stability mains operated valve heater supply  details are given
of a circuit using a high gain tuned amplifier with feedback controlled
by a thermistor bridge
   /
2172
a four transistor dc converter circuit for use with relatively high
voltage supplies  an experimental bridge circuit is described with
a power output of and conversion efficiency
   /
2173
digital computers available in britain  information on computers
is given in tabulated form
   /
2174
digital differential analysers  principles of operation are described
and details are given of the design of the avro dda machine addam
   /
2175
ferroelectrics and computer storage  the polarization reversal process
in ferroelectric single crystals and its application to data storage
is reviewed  an optical system for reading information from a ferroelectric
store is described
   /
2176
magnetics for computers a survey of the state of the art  a review
of the application of magnetic materials to storage and switching
devices
   /
2177
transistorized core memory
   /
2178
transistors provide computer clock signals  switching circuits capable
of high speed and controlling peak currents up to are described
   /
2179
digital storage on punched tape
   /
2180
the storage and processing of digital data on magnetic tape
   /
2181
the noise problem in a coincident current core memory
   /
2182
the printed circuit  summary of manufacturing and assembly techniques
   /
2183
circuits for ternary switching variables  applications of a ternary
switching algebra are considered and the synthesis of a ternary adder
is described
   /
2184
design of toroidal coils with ferrite cores operating in the audio
frequency range  a method of determining the optimum relation between
core dimensions is outlined  this gives the minimum coil size for
a given q factor or the maximum q factor for a given size
   /
2185
auto self excited transductors  basic circuits are examined nonmathematically
considering only resistive loads
   /
2186
coincidence diodes gate electronic switch  a transistor switching
circuit for radar indicators is described  six channels are used
in each coordinate axis of a cro presentation
   /
2187
hydromagnetic capacitor
   /
2188
accurate determination of the capacitance of rectangular parallel
plate capacitors  the subarea method is recast and applied to derive
a universal curve for a square plate capacitor values calculated
by other methods are compared
   /
2189
elements of electronic circuits part time constant and differentiation
first of a series of articles reviewing basic electronic circuits
with emphasis on physical explanations of their operation
   /
2190
analogous transistor system design and nodal methods of construction
with applications to research equipment and prototype evaluation
transistor action and circuits are described in terms of the thermionic
valve analogy  a modular technique of circuit construction based
on this principle is described in which stages are assembled individually
using a method which simplifies their interconnection
   /
2191
on the reactance theorem  any passive quadripole with foster type
short circuit and open circuit impedances at either end transforms
any foster type two terminal network into a foster type two terminal
network again  polygons consisting of foster type two terminal networks
are also considered  see also of
   /
2192
group delay and group velocity  the concepts are defined and their
relation to the transfer function of a network is given  see also
of
   /
2193
radio engineering use of the minkowski model of the lorentz space
   /
2194
the condition of passivity for the linear quadripole with complex
characteristic impedances  reciprocal and non reciprocal two port
networks are considered
   /
2195
an analysis of lossy symmetrical quadripoles in the decimetre and
centimetre wavelength ranges using voltage node displacements  see
also of
   /
2196
a combined pulse width filter for television receivers  synchronization
by means of a combined integrating and differentiating filter network
is described  performance data are tabulated
   /
2197
intermediate frequency circuits with three coupled resonators  the
operation of triple tuned wide ba d bandpass filters is analysed
and design formulae are tabulated  for data on double tuned filters
see of
   /
2198
theory of the crystal controlled inductive three terminal circuit
conditions of oscillation equivalent circuits and methods of compensation
for the crystal controlled hartley oscillator are discussed
   /
2199
transistorized crystal controlled marginal oscillator  circuit details
of a small non microphonic oscillator unit for nuclear magnetic resonance
observations
   /
2200
operating conditions of the symmetrical multivibrator  an approximate
method for the division of a multidimensional phase space into sub
spaces is described and applied to analyse the operation of a symmetrical
multivibrator taking account of parasitic capacitance and grid
current  three modes of operation are considered
   /
2201
multivibrator with negative feedback  a description is given of a
multivibrator circuit with very good frequency stability
   /
2202
improved rc oscillator  a modified version of the bridged t circuit
described by sulzer this oscillator operates at a single frequency
in the range
   /
2203
the conditions for the onset of oscillation in transistor oscillators
the condition for self oscillation is established and oscillators
are considered in two groups with frequency either dependent on or
independent of transistor parameters
   /
2204
transistorized nuclear resonance magnetic field probe  description
of a marginal oscillator type of nuclear resonance detector
   /
2205
frequency stable transistor oscillators in carrier frequency techniques
the design of a meacham bridge oscillator is given
   /
2206
reversible dekatron counter  a counter circuit is described which
has two inputs one of which allows addition to and the other subtraction
from an existing count
   /
2207
the static characteristics of the cathode coupled limiter clipper
   /
2208
cathode compensation  the design of a cathode compensated pentode
video stage is discussed particularly the selection of values for
the cathode resistor and capacitor and the use of a bleed resistor
   /
2209
response of cascaded double tuned circuits  the transient and steady
state responses are developed in terms of the location of the poles
of the transfer function  the results can also be applied to networks
with a response asymmetrical about the band centre but with a narrow
relative bandwidth
   /
2210
design of transistor rc amplifiers
   /
2211
transistor nonlinearity dependence on emitter bias current in pnp
alloy junction transistors
   /
2212
radiation damping effects in two level maser oscillators  analytical
note on the modulation effects occurring in a spontaneously radiating
inverted two level spin system
   /
2213
phase distortionless limiting by a parametric method  nearly ideal
limiting can be obtained by using the signal to be limited as the
pump frequency nonlinear capacitance amplifiers  an account of the physical
principles and the design of variable capacitance amplifiers  the
effective noise temperatures achieved are compared with those of
other low noise amplifiers and of terrestrial and extraterrestrial
noise sources
   /
2214
a three frequency electron beam parametric amplifier and frequency
converter
   /
2215
gain bandwidth and noise in a cavity type parametric amplifier using
an electron beam
   /
2216
travelling wave couplers for longitudinal beam type amplifiers
   /
2217
the physical principles of a negative mass amplifier  negative effective
masses for relatively low energies may be obtained if the energy
contours are reentrant near the edge of the frequency band as in
the case for heavy holes in germanium and certain other semiconductors
with degenerate band edges  operation at frequencies up to mm is
envisaged
   /
2218
microwave ferrite modulators for high signal frequencies  methods
are suggested for avoiding ferromagnetic resonance  skin effects
are overcome by using the waveguide as a modulating helix  performance
details of two experimental modulators for x band frequencies are
given
   /
2219
frequency modulator for a marginal oscillator  a voltage sensitive
capacitor with dc bias is used in the tank circuit of the oscillator
   /
2220
the accuracy obtainable with transistors in pulse amplitude and pulse
width modulation  the effects of ambient temperature and power supply
fluctuations on transistor pm circuits for telemetry applications
are analysed  the design of a pam pwm converter is given
   /
2221
photoconductivity as a function of optical absorption  a theoretical
analysis of the dependence of photoconductivity on optical absorption
based on the concept of a schubweg or mean range for the optically
liberated charge carriers of each sign
   /
2222
correlation function for a system of particles carrying like charges
a description of a mathematical method for the determination of correlation
functions for systems of particles carrying like charges  this
method could be extended to charges of different sign and also to
the kinetic theory of charged particles  see also of tyablikov and
tolmachev
   /
2223
a dielectric formulation of the many body problem application to
the free electron gas
   /
2224
theory of the contribution of exciton to the complex dielectric constant
of crystals
   /
2225
graphical analytical construction of the space trajectory of charged
particles in magnetic fields  two methods are described for plotting
the trajectory of relativistic charged particles an acceleration
method and the radii of curvature method
   /
2226
effect of space charge in cold cathode gas discharges  townsends
basic ionization equations for cold cathode discharges between parallel
plates are modified by poissons equation to account for space charge
effects  numerical calculations have been made for argon
   /
2227
high frequency breakdown in air at high altitudes  breakdown field
is computed for and from atmospheric data the validity of which is
discussed  considerably more power per unit area can be transmitted
at the higher frequencies
   /
2228
longitudinal oscillations of electron ion beams  investigation of
the stability of electron ion beams leads to a differential equation
that is difficult to solve  a qualitative method based on self conjugate
differential operators is used which avoids solution of this equation
   /
2229
compensation of space charge in an electron beam  measurements of
the electric field of the space charge in the beam were carried out
to evaluate the lifetime of the virtual cathode
   /
2230
calculation of the spatial and angular distribution of a stream of
particles with multiple scattering  scattering of electron beams
is considered taking account of absorption and retardation effects
   /
2231
energy spectrum of secondary electrons emitted by a metal under the
action of a fast ion beam  spectra have been analysed by means of
a magnetic spectrograph
   /
2232
solar proton stream forms with a laboratory model
   /
2233
a transit time relation for plasma electron oscillations
   /
2234
microwave propagation in hot magneto plasmas  the refractive indices
for circularly polarized waves propagating along the magnetic field
in an ionized gas at high temperature are calculated  they are found
to depend sensitively on electron density and temperature
   /
2235
conductivity of plasmas to microwaves  a new derivation of an expression
previously obtained for plasma conductivity see of and an alternative
expression which avoids previous difficulties with negative conductivities
   /
2236
hydromagnetic capacitor  very high dielectric constants can be achieved
with an ionized gas in a strong magnetic field  when an orthogonal
electric field is applied resultant particle drift stores electrical
energy  dielectric constants from to have been measured in a coaxial
capacitor using a rotating plasma disk  potential use in fast discharge
work is considered
   /
2237
on the question of quantum effects in the interaction of electrons
with high frequency fields in resonators  it is shown that the quantum
effect corresponds to the interaction of electrons with a neutral
oscillatory field in the resonator  methods of quantum mechanics
are avoided by using the nyquist formula
   /
2238
the band between microwave and infrared regions  difficulties that
have hitherto prevented microwave generation in the region are discussed
schemes which might overcome these difficulties are considered
   /
2239
multistage resonance absorbers for centimetre electromagnetic waves
a three stage dipole resonance absorber is drived from the two stage
absorber described in of schmitt by the addition of a second dipole
grid at a distance of in front of the metal surface  the frequency
characteristics of the reflection coefficient are calculated and
compared with the results of measurements
   /
2240
the absorption of centimetre electromagnetic waves in artificially
anisotropic media  two methods of equalizing the complex permeability
and dielectric coefficient of a medium to obtain absorption at are
discussed  in one case the medium consists of thin parallel layers
in the other use is made of gyromagnetic resonance in ferrite material
subjected to a static magnetic field  experimental results are given
   /
2241
the group velocity of damped waves  the group velocity is shown to
be equal to where is the component of the poynting vector along the
direction of propagation and w the energy density  the electromagnetic
energy and group velocities are calculated for a simple medium a
plasma and a dielectric with bound electrons
   /
2242
kinematics of growing waves  analytical treatment of the problem
of distinguishing between amplifying and evanescent waves
   /
2243
asymptotic development of double integrals encountered in diffraction
theory
   /
2244
a new method for the solution of a problem of diffraction of electromagnetic
plane waves at an unlimited rectilinear slit and related problems
using the method described a good approximation to the exact solution
of the diffraction problem can be obtained for normally incident
plane waves of wavelength much smaller than or equal to the width
of the slit
   /
2245
radio frequency spectra of hydrogen deuteride in strong magnetic
fields
   /
2246
steady state free precession in nuclear magnetic resonance  description
of a new technique for observing nuclear magnetic resonance
   /
2247
an x band spectrometer for the demonstration of paramagnetic resonances
a bridge type spectrometer with frequency stabilization is described
   /
2248
theory of cyclotron resonance in metals  analysis of the low temperature
case in which the mean free path of the electrons is greater than
the skin depth
   /
2249
multiple quantum transitions in paramagnetic resonance  at high rf
field strengths the normal paramagnetic resonance spectrum of in
cubic mgo is found to be modified by additional absorption lines
which are interpreted as double quantum transitions occurring between
nearly equally spaced energy levels at high rf power  calculation
of the relative absorption intensity for which transitions agrees
with experimental results
   /
2250
infrared and optical masers  theoretical aspects of maser like devices
for wavelengths much shorter than cm are discussed  the short wavelength
limit for practical devices is examined  design principles are
illustrated by a system for the infrared region using potassium vapour
   /
2251
the effective radius of the electron in crystal lattices  the effective
radius of electrons in metals determined by different methods is
found to be
   /
2252
relation between the constants characterizing the interaction of
electrons with phonons and impurities in metals  a mathematical analysis
   /
2253
unusual cosmic ray intensity fluctuations observed at southern stations
during october  the fluctuations observed have unusual features which
suggest the existence of a short lived and highly directional anisotropy
of the primary radiation during the period immediately preceding
a forbush type decrease
   /
2254
international convention on cosmic rays  the text is given of over
papers presented at a convention held at varenna  the subject matter
is divided into the following groups solar and geomagnetic effects
on cosmic rays problems of origin composition of primary radiation
air showers and interactions of cosmic radiation
   /
2255
latitude variation of day cosmic ray intensity decreases  the latitude
variation of decreases in cosmic ray intensity due to the modulation
effects of a geocentric nebula of disordered magnetic fields has
been measured  experimental data provided by neutron monitor observations
during the period of intense solar activity show that equatorial
variations exceed calculated values by a factor of two or more
   /
2256
radio observations of the lunar surface  information about the moons
surface can be obtained from a statistical consideration or radar
scattering from the surface
   /
2257
solar proton stream forms with a laboratory model  a stormertron
tube is described for simulating the streams of charged particles
in the earthsdipole magnetic field photographs of stream forms and
contacts are presented  the same techniques can be used to study
stream forms in other complicated magnetic fields
   /
2258
recurrent geomagnetic storms and solar prominences  an examination
of the association of prominence areas with days of recurrent storms
during t period the identification of m regions with solar prominences
is not confirmed
   /
2259
motion of a satellite around an unsymmetrical central body  comment
on of
   /
2260
a determination of the coefficient j of the second harmonic in the
earths gravitational potential from the orbit of satellite
   /
2261
vanguard igy satellite beta  the instrumentation used the measurements
made and the uses of the satellite are described  information on
satellite temperatures and rotation rate is given  orbital data are
being used for measuring the oblateness of the earth and for correcting
mapping errors
   /
2262
information by radio from the satellites  an account of some early
results obtained mainly from observations of satellite
   /
2263
igy conference in moscow soviet papers presented at the rocket and
satellite symposium  summary of preliminary data presented at the
general assembly of csagi moscow august
   /
2264
densities and temperatures of the upper atmosphere inferred from
satellite observations  the atmospheric density between and km altitude
appears to be appreciably higher than that derived from rocket data
the temperature in this region must therefore be higher than that
given by present model atmospheres  the density is still below that
derived from meteor data
   /
2265
investigation of the upper atmosphere by means of the third artificial
earth satellite  a brief description of geophysical investigations
carried out in ussr  the temperature variation and the distribution
of the electron density with height up to about km are discussed
and the collision of an artificial satellite with micro meteorites
is considered
   /
2266
the ionosphere and artificial earth satellites  two methods for investigating
the ionosphere are briefly described the doppler shift of
emitted signals and the observation of the times of radio rise and
radio setting of the satellites  from the difference between the
optical and the radio observations of the rising and setting the
electron concentration can be calculated
   /
2267
satellite doppler measurements and the ionosphere  simultaneous doppler
measurements of satellite at frequencies of and were shown to be
in agreement with an approximate model of the ionosphere for the
same period
   /
2268
transoceanic communication by means of satellites
   /
2269
temperatures in the high atmosphere  temperature distribution is
discussed in relation to rocket and radio observations on the assumption
that heating of the ionosphere is due primarily to solar radiation
and that temperature distribution is controlled by thermal conduction
a model is presented which indicates a very rapid temperature rise
between and km  this would produce a density distribution in agreement
with observations
   /
2270
the temperature in the atmospheric region emitting the night glow
line and in regions above faint auroral arcs
   /
2271
effect of vertical drifts on the nocturnal ionization of the lower
ionosphere  vertical ionic drifts present in quiet conditions and
enhanced during a magnetic storm result in a vertical redistribution
of ionization and thus change the apparent recombination coefficient
at a given height  the resulting n profiles are calculated and shown
to explain the sudden cessation of night time echoes of lf radio
waves at times of magnetic disturbance reported by linquist
   /
2272
a survey of the present knowledge of sporadic e ionization  discussion
of the various techniques of observi g e and the classification of
the phenomenon by geographical zones auroral temperate and equatorial
and by type as evidenced by the trace recorded on an ionogram  the
diurnal and seasonal variations in the three zones are shown to be
quite distinct  various theories of the nature of the ionization
formations and the agencies producing them are considered and the
subjects requiring special experimental and theoretical attention
are indicated  over references
   /
2273
lunar tides in the sporadic e layer at ibadan  an analysis of the
lunar semi diurnal tides in is made for ibadan  the results are presented
in the form of harmonic dials  comparisons are made between these
results and those of other stations
   /
2274
ionospheric measurements made at halley bay  graphs of the monthly
median values of at halley bay for july winter september equinox
and december summer are given  a large diurnal variation of electron
density occurs in winter  the seasonal maximum of electron density
during the day is found at the equinoxes
   /
2275
the diurnal and annual variations of over the polar regions  the
variations have been studied for about stations over a three year
period and the following results have been found the diurnal variation
is largest in winter and smallest in summer the maximum values of
occur at noon in the northern and at midnight in the southern hemisphere
there is a regular annual variation for a given time of day in northern
winter has deep minima in the morning and evening in summer the latitude
differences in are small but become large in winter up to per degree
the lines of equal critical frequency lie between circles of geographic
and geomagnetic latitude
   /
2276
ionospheric changes at singapore during the solar eclipse of december
the eclipse occurred in the late afternoon and no simple interpretation
of the changes in the e and f layers can be given  the critical frequency
of the f layer did not change but there were considerable eclipse
effects in the lower part of the f layer
   /
2277
an analysis of drifts of the signal pattern associated with ionospheric
reflections  a statistic treatment to determine the drift and random
velocity components from the signals observed on three spaced receivers
particular attention is given to the random motion in order to examine
the detailed movement of the pattern  the results suggest a ruled
pattern undergoing fluctuations in contour spacing as the pattern
drifts across the receiver site
   /
2278
triple splitting of the f echoes  polarization measurements of triple
split echoes at banaras agree with measurements at high latitudes
the process concerned in producing triple splitting at low latitudes
is discussed
   /
2279
arctic measurements of electron collision frequencies in the d region
of the ionosphere  simultaneous measurement of refractive indices
and the difference in the absorption of the two magneto ionic components
of a signal transmitted from a rocket allowed the electron collision
frequency profile to be determined  the results of two midday flights
indicate that the frequencies are lower by a factor of three than
the unpublished theoretical values calculated by nicolet
   /
2280
electric field theory of aurorae  a qualitative description of the
development of a typical auroral display following the growth of
an electric field in the ionosphere
   /
2281
an artificial aurora  the auroral display at apia reported by cullington
of could not have been caused by direct radiation from the explosion
of a nuclear bomb at johnston island which is approximately miles
away but was probably due to charged particles from the explosion
   /
2282
a bistatic radio investigation of auroral ionization
   /
2283
ire standards on static magnetic storage definitions of terms
   /
2284
magnetic head reads tape at zero speed  design details of a system
enabling recorded hf signals to be played back at speeds low enough
for the output to be fed to a pen recorder without deterioration
in signal noise ratio
   /
2285
development of the transistor inverter at using power transistors
   /
2286
physical and electrical properties of silicon rectifiers for communications
applications  small junction type diodes with a current carrying
capacity of up to a are considered
   /
2287
current integration with solion liquid diodes  the construction and
characteristics of electrochemical diodes using iodine potassium
iodide solution are described see of  these can be used as electrical
current integrators and flow or pressure detectors
   /
2288
a new concept in computing  the phase of a sine wave signal is used
as an information bearing medium which together with majority logic
permits the realization of logic operations  nonlinear reactances
are employed  computing can be carried out more rapidly than by present
techniques if microwave frequencies are used
   /
2289
a new high speed digital technique for computer use  square loop
ferrite cores and transistors are used operating at digit rates of
only two low voltage dc supplies are required and the system is not
critically dependent on voltage and component variations
   /
2290
the automatic computing engine at the national physical laboratory
   /
2291
digital memory system keeps circuits simple  a magnetic disk memory
of to words capacity using simple control and selection circuits
   /
2292
a general approach for obtaining transient response by the use of
a digital computer  adaptation of digital computers to the inverse
laplace transformation process and the fourier integral method is
shown to have major advantage in determining the transient response
of linear control systems
   /
2293
the use of hall generators in analogue multipliers  experimental
equipment incorporating an inas crystal hall generator is described
   /
2294
operating experience with a transistor digital computer  a description
of the performance of a small laboratory model digital computer over
a period of a year with analysis of service ability and transistor
failures  the failure rate of point contact transistors was higher
than expected but was of the same order as that quoted by other workers
for standard thermionic valves in digital computers
   /
2295
quadratic interpolation in tapped potentiometer function generators
the quadratic variation of the resistance to ground from the slider
of an auxiliary potentiometer interpolating between the tapping points
on the function generating potentiometer is utilized to achieve quadratic
interpolation
   /
2296
verification of the logic structure of an experimental switching
system on a digital computer  the verification problem is concerned
with the construction on a computer of a logical program which satisfies
all the design specifications prescribed for an experimental switching
system and with the process of putting calls though the computer
simulation to evaluate the systems logical structure
   /
2297
stable high speed digital to analogue conversion for storage tube
deflection  discussion of the design of access circuitry for a barrier
grid tube temporary storage system which converts a bit binary address
into the analogue voltage necessary to deflect the electron beam
to a specific storage area defined by the address  a special feedback
circuit and raster reference tube control the size and centring of
the array of storage s  study of the impedance of capacitors as a
function of frequency  strip stacked and disk type capacitors have
been studied  the natural resonant frequency is almost entirely dependent
on the capacitance value and the connections
   /
2298
solid electrolyte tantalum capacitors  the manufacturing process
is described and the temperature characteristics and results of life
tests are given
   /
2299
elements of electronic circuits part clamping or dc restoration
   /
2300
the physical realizability of a microwave junction  the conditions
are derived which must be satisfied by a matrix to represent the
admittance impedance or scattering matrix of a junction at a given
fixed frequency
   /
2301
the ferroresonant circuit  a theoretical and experimental treatment
of the resonance obtained by varying the voltage applied to a circuit
containing an iron cored inductance
   /
2302
behaviour of the ferroresonant series circuit containing a square
loop reactor
   /
2303
the present state of crystal resonator techniques  review of production
techniques with details of performance obtained in recent applications
of crystal resonators in frequency standards filters and delay lines
references
   /
2304
the expansions of electromagnetic fields in cavities
   /
2305
travelling wave resonators
   /
2306
gyrators and nonreciprocal systems  discussion of the conditions
necessary for a linear four terminal network containing only passive
elements and gyrators to have different attenuations in either direction
   /
2307
a new synthesis procedure for two terminal pair networks using the
symmetrical lattice structure
   /
2308
synthesis of lc networks  a method is outlined for the synthesis
of certain voltage transfer functions by means of asymmetrical balanced
lc networks terminated at the load end by a resistance  a simplified
analysis of transients in linear circuits caused by the frequency
modulation of an input signal  a simplified method of investigation
of transients is described with the introduction of the concept of
the transmission frequency coefficient  an explanation is provided
for the mechanism of dependence of the time constant of the frequency
transient on the frequency of modulation of the input signal  the
frequency coefficients of transmission for aperiodic and differentiating
circuits are also considered
   /
2309
wave matrices of a quadripole  th  use of scattering and transmission
matrices for cm wave quadripoles is considered and the essential
properties of these wave matrices are determined  the method is illustrated
by a practical example in which an examination is made of the
modulus and phase of the reflection coefficient of a waveguide filter
consisting of two equal inhomogeneities and separated by a section
of waveguide propagating an wave
   /
2310
interchange of infinite attenuation elements in ladder filter structures
formulae are given for interchanging series antiresonant and shunt
resonant circuits
   /
2311
branched filters  the theories of cauer and piloty relating to constant
impedance branched networks are supplemented and applied using image
attenuation functions instead of cauers insertion loss function
an eight terminal network using two low pass and two high pass filters
without a differential transformer is described
   /
2312
the reactance transformation of low pass into band pass ladder networks
the low pass network is subdivided into quadripole elements which
are then combined to form the band pass network
   /
2313
development of filter technique in france during the last ten years
   /
2314
flexural vibrations in mechanical filters  matrix methods are used
for calculating the characteristics of flexural vibrations in rods
and the results are compared with those measured by an experimental
method described  the design of mechanical filters with torsional
and longitudinal vibrations and free from flexural waves is discussed
   /
2315
mechanical filters for communications technique  english summary
the principle of operation and the design of filters consisting of
magnetostrictive transducers and mechanical resonators are described
details are given of a if band filter and a ssb filter for a carrier
frequency of
   /
2316
transistor active filters using twin t rejection networks
   /
2317
a topological investigation of network determinants  the main result
gives the determinant of the nodal admittance matrix of a rlc network
without mutual inductance or ideal transformers
   /
2318
the practical design of two phase networks  an example illustrating
the theory given in of
   /
2319
linear multitapped potentiometers with loaded outputs  an analysis
of multitapped linear potentiometers is given for the type in which
shunt resistors are connected between adjacent tapping joints and
in the presence of an output load resistance
   /
2320
a simple very low frequency oscillator  amplitude limitation is effected
by a zener diode and a selective circuit filters out the resulting
harmonics giving amplitude stabilization that is not frequency selective
   /
2321
transistorized generator for pulse circuit design  the generator
produces pulses of duration at repetition frequencies from to  the
maximum amplitude is into a load  type switching transistors are
used
   /
2322
transistor phase locked oscillators  an analysis followed by detailed
design data for two systems one operating at and the other at mcs
   /
2323
greater gain bandwidth in trigger circuits  a special series connection
of two valves produces a gain bandwidth product per stage of up to
three times that of a conventional amplifier without introducing
the unwanted time delay associated with a distributed amplifier
   /
2324
cathode follower for a dc reference level  describes the use of a
cathode follower to provide a variable reference voltage source with
a low output impedance
   /
2325
design criteria for low level second harmonic magnetic modulators
detailed analysis of a device suitable for low level dc amplification
   /
2326
how to design pulsed distributed amplifiers  principles of operation
are discussed and basic design equations are listed  details of design
procedure and performance of a power amplifier operating around are
given
   /
2327
the effect of reaction on the gain of nonlinear amplifiers  an analysis
in which it is shown that in certain conditions the nonlinear differential
equation may be reduced to a linear equation of infinite order
with constant coefficients
   /
2328
performance of class b audio amplifiers with random noise signals
two basic limitations on performance are considered average anode
power dissipation is the same as that for sinusoidal modulation
but the positive grid operation permitted is slightly different
   /
2329
construction of a logarithmic wide band amplifier  the equipment
described has a gain of about  amplification is linear for input
voltages up to and proportional within db to the logarithm of the
input voltage from to  frequency response is linear from to
   /
2330
construction of a logarithmic wide band amplifier  the equipment
described has a gain of about  amplification is linear for input
voltages up to and proportional within db to the logarithm of the
input voltage from to  frequency response is linear from to
   /
2331
variable magnetic amplifier  a method is described for varying the
current gain by means of a variable impedance in parallel with the
feedback rectifiers
   /
2332
volt second transfer efficiency in fast response magnetic amplifiers
part and control  analysis for the case of finite control circuit
resistance and non ideal core characteristics  defined as the summation
of the quotients of the square of the number of turns and the circuit
resistance for all control circuits is shown to be a basic reactor
parameter
   /
2333
on feedback in magnetic amplifiers part single feedbacks  feedback
configurations associated with two core full wave self saturating
amplifiers are analysed and compared
   /
2334
magnetic amplifiers for servo systems  tabulated comparison of seven
different combinations of push pull magnetic amplifier units
   /
2335
linear power amplifiers using dynistors or trinistors  the use of
two or three terminal semiconductor switching devices with a pulse
network in series with the output of a magnetic amplifier transducer
acting as an amplitude phase converter is described  these amplifiers
are much smaller than conventional magnetic amplifiers of comparable
maximum output power  resistive or inductive loads can be used
   /
2336
transistor amplifier for magnetic tape and drum playback  the amplifier
operates from a input over the range and from to c  rise time of
the output pulse is less than s  details are given of the design
and full performance
   /
2337
a stable direct coupled transistor servo preamplifier  capable of
dc operating point stability and high gain at
   /
2338
the three level solid state travelling wave maser  theoretical comparison
is made between the characteristics of the travelling wave maser
and those of the cavity maser and the general requirements for slow
wave structures are discussed  theoretical analysis and experimental
results are presented for the comb in waveguide slow wave structure
   /
2339
a uhf ruby maser  the maser is tunable over the range and consists
of a ruby crystal at the centre of a teflon loaded cavity which is
excited in a te pump mode
   /
2340
three level masers as heat engines
   /
2341
calculation and measurement of the noise figure of a maser amplifier
   /
2342
stimulated rf amplifiers working on hyperfine levels of paramagnetic
atoms  a note on the possibility of obtaining signal amplification
in the frequency range using crystals of salts containing bivalent
ions of the isotope  with oersteds to and number of paramagnetic
ions the stored energy for one pair of hyperfine levels will be of
the order of to ergs  for a pulse duration of sec the output power
may reach w
   /
2343
parametric devices tested for phase distortionless limiting  tests
on two devices are described one is a amplifier and the other an
s band converter both use variable capacitance diodes
   /
2344
directional bridge parametric amplifier  a description is given of
the operation and performance of a directional bridge system using
variable reactance diodes
   /
2345
gain measurements on a pulsed ferromagnetic microwave amplifier
the amplifier operates in the quasi degenerate mode in which one
cavity serves as the resonant circuit for both the signal and the
idle frequency fields  a second cavity is used for the pump signal
which is pulsed
   /
2346
low noise parametric amplifier  a note of preliminary analytical
and experimental results obtained with a cavity type amplifier for
the s band in which through variable coupling the effect of diode
losses on noise figure can be minimized at the expense of pump power
   /
2347
a comparison of the transient response of amplitude modulated and
frequency modulated signals  the performance of rc and rl circuits
filters and transmission lines is analysed
   /
2348
the diode reactance modulator  a detailed analysis of the control
of current through a capacitor by one or more diodes
   /
2349
a magnetic amplifier commutating and pulse width encoding circuit
description of a circuit designed for telemetry applications
   /
2350
acoustoelectric effect  three general approaches to the theory of
the effect are discussed and a development of the phenomenological
approach is given in detail for metals and semiconductors  see of
   /
2351
a new determination of the freespace velocity of electromagnetic
waves  a full description of the experiments briefly described in
of
   /
2352
the theory of interference modulation for double beam interference
infrared interferometry is discussed
   /
2353
spectroscopy in the far infrared by means of interference modulation
practical application of the principle discussed in above
   /
2354
a simple method of calculating electrostatic capacity  attention
is drawn to a simple theorem for evaluating the capacitance of certain
conductors in free space such as a system of two spheres in contact
with each other or a ring without hole
   /
2355
diamagnetism of conduction electrons in metals  calculation made
by using a reasonably simple form for the field independent part
of the susceptibility
   /
2356
a superconductor in a high frequency field  an equation is derived
which describes the behaviour of a superconductor in a high frequency
field and the frequency and temperature dependence of the impedance
of a bulk superconductor are evaluated
   /
2357
electrical discharges  report of a conference held by the physical
society in swansea sept
   /
2358
theoretical total energy distribution of field emitted electrons
   /
2359
experimental measurement of the total energy distribution of field
emitted electrons
   /
2360
magnetic analysis with electron beams  a device based on the lorentz
effect is used to estimate remanent magnetism  see also of
   /
2361
an extension of townsends approximation formula for ionization in
a homogeneous electric field  the use of an additional parameter
improves the approximation and extends the range of validity for
lower field strengths  a general approximation formula is proposed
for ionization dependent simultaneously on both field strength and
voltage
   /
2362
on the damping of electromagnetic waves in a plasma situated in
a magnetic field  using expressions derived by sitenko and stepanov
for the components of the permittivity tensor an expression for the
damping coefficient is obtained
   /
2363
conductivity of plasmas to microwaves  plasma conductivities for
electrons with a maxwellian energy distribution are evaluated for
the cases in which the collision cross section independent of the
velocity and inversely proportional to the velocity  the corresponding
distribution functions of relaxation times are discussed
   /
2364
microwave investigation of disintegrating gaseous discharge plasmas
the phenomenon of afterglow is investigated both theoretically and
experimentally by considering the shift of the resonance frequency
of a microwave cavity enclosing the plasma  measurements using binary
gas mixtures show the production of a considerable number of atomic
ions of the admixture even at low concentrations  the process concerned
in helium neon is a charge transfer one between a ion and a neon
atom the relevant cross section being cm  in other mixtures the atomic
ions are produced by the penning effect and possibly the charge transfer
process
   /
2365
guided propagation in a slowly varying medium  formulae are derived
for the propagation of elastic or em waves in a variable stratified
medium with particular application to underwater sound transmission
   /
2366
absorption of electromagnetic waves by means of lossy resonant slots
very thin microwave absorbers can be constructed by using a sheet
of resistive with tuned slots at a distance in front of a metal plate
the bandwidth can be increased by the insertion of a grid of dipoles
and the effects of polarization are minimized if circular slots are
used  see also of june
   /
2367
phase object diffraction patterns in microscopes and microwave fields
optical phase diffraction patterns are interpreted by analogy with
patterns obtained by a microwave technique at cm
   /
2368
velocity modulation of electromagnetic waves
   /
2369
propagation of an electromagnetic impulse in a medium with dielectric
losses
   /
2370
high q stark cavity absorption cell for microwave spectrometers
design description and performance data are given of a large pillbox
shaped stark cavity absorption cell for the region  the cavity can
be used in any mode with ranging from about to
   /
2371
theory of the anisotropy of the width of ferromagnetic resonance
absorption lines  the dependence of the width of a radio frequency
resonance absorption line on the internal field is derived from the
landau lifshits equation and examples of ferrites with single axis
and cubic symmetry are examined
   /
2372
microwave spectrometer tests electron resonance  a method of measuring
the absorption properties of paramagnetic materials in which a sample
is immersed in a dc field whose strength is varied to determine the
value at which rf energy is absorbed by the sample
   /
2373
three level masers at heat engines  it is shown that a three level
maser can be regarded as a heat engine and its limiting efficiency
is that of a carnot engine  the possibility of treating masers as
heat engines represents a fundamental difference between masers and
parametric amplifiers
   /
2374
absorption and refraction of ammonia as a function of pressure at
wavelength  description of measurements made using a resonant cavity
technique
   /
2375
exact foundations of the theory of spin waves  the validity of equations
of the type of blochs spin wave equations is proved for the multi
electron problem disregarding spin interactions
   /
2376
theory of electron phonon interactions  the theory has been formulated
for nonpolar crystals in terms of a new set of basic states whose
wave functions are essentially bloch functions that deform with the
lattice  a result of this is a generalization of the deformation
potential theorem
   /
2377
possible mechanism by which terrestrial corpuscular radiation arises
in response to the action of cosmic rays  expressions are derived
giving the total number of protons and electrons generated per second
at the equator in a tube of cross section  the dependence of the
intensity of the earths corpuscular radiation on height and latitude
is shown graphically  experiments show that the intensity near the
equator is approximately times less than that calculated which indicates
the existence of supplementary leaks from magnetic traps especially
noticeable at high latitudes
   /
2378
possible explanation of the radiation observed by van allen at high
altitudes in satellites  the possibility is considered that the radiation
is due to the decay electrons and protons from neutrons produced
by cosmic rays and stored in the earths magnetic field
   /
2379
radiation transfer and the possibility of negative absorption in
radio astronomy  conditions are discussed under which negative absorption
can arise at radio wavelengths when the medium will behave like
an amplifier to the incident radiations  the necessary conditions
can be met in cases where the dominant radiation process is due to
the cherenkov effect gyro radiation or synchrotron type radiation
   /
2380
radio interferometry at three kilometres altitude above the pacific
ocean  a lloyds mirror type of interferometer using the surface of
the sea as a mirror is described whose effective spacing changes
in a continuous manner from zero to km during about one half hour
the fluctuations caused by the ionosphere are discussed and the measurements
of the fine structure details of cassiopeia cygnus hydra the
sun and jupiter are described
   /
2381
a pencil beam survey of the galactic plane at m  a survey has been
made of the galactic plane region from through the galactic centre
to between and using the cross type aerial beamwidth min of arc near
sydney  contour diagrams of brightness temperature have been prepared
the preparation of contours is described in detail and a detailed
discussion of the accuracy of the temperatures is given
   /
2382
radio emission from the vela puppis region
   /
2383
the radio emission from centaurus a and fornax a
   /
2384
a search for radio emission at m from the local supergalaxy
   /
2385
approximations for the electron density in meteor trails  improved
approximate expressions for describing conditions near the point
of maximum electron density for both fast and slow meteors are compared
with herlofsens exact solution see
   /
2386
oblique echoes from over dense meteor trails  ray paths are computed
for waves refracted by meteor trails  curves are derived showing
how the echo duration depends on the trail orientation these curves
show that the sec law applies for overdense trails only if the plane
of propagation contains the trail axis  if not the effective secant
exponent may be as small as  the theory is in agreement with duration
measurements of mckinley and mcnamera and gives results similar to
the more complex wave solutions of keitel see of
   /
2387
investigation of the drifts of the effective point of radio reflection
along a meteor train  experimental evidence is given to support the
postulate of the drift of the effective point of reflection along
a meteor train towards the maximum echo duration level  drift velocities
tend to have higher values in the case of shorter echo durations
and vice versa  from theoretical considerations it is predicted that
maximum echo durations always occur at about km below the height
of maximum ionization  the degree of turbulence is considered to
be slightly greater than that suggested by manning but less than
that by booker and cohen  see also of rao
   /
2388
the limitations of narrow beam radio equipments in the detection
of weak meteor showers  fluctuations in background activity diffuseness
of shower radiants and the short interval over which some showers
are active are the chief limitations  a significance test for use
as a search method for weak showers is developed
   /
2389
first results on the lunar diurnal variation of the horizontal component
of the geomagnetic field at tamanrasset
   /
2390
an apparent relationship between geomagnetic disturbances and changes
in atmospheric circulation at millibars  contour length and trough
indices are used as a measures of atmospheric disturbance over north
america and the eastern pacific ocean  these features were studied
for periods following geomagnetic disturbances from to march  there
appears to be a significant relation between geomagnetic activity
and the development some days later of wave phenomena at the level
   /
2391
radio electronics and cosmic flight  a brief description of the flight
of the russian cosmic rocket launched on the january  the scientific
equipment carried in the last stage and the possibilities open to
these rockets for interplanetary space investigation are also examined
   /
2392
study of cosmic rays and terrestrial corpuscular radiation by cosmic
rocket  a preliminary examination of data obtained by the cosmic
rocket at distances between and from the centre of the earth  graphs
show that a maximum intensity of terrestrial corpuscular radiation
is found at a distance of and that at this intensity falls to zero
the density of cosmic rays was found by geiger counter to be particles
cm sec and by scintillation counter to be particles cm sec
   /
2393
methods for predicting the orbits of near earth satellites  methods
are described for predicting the times and positions of the daily
transits of a satellite and the geometry of its orbit  the methods
depend upon maintaining an accurate record of the period of revolution
from which the other orbital elements are deduced theoretically
   /
2394
the effect of the earths oblateness on the orbit of a near satellite
the equations of motion of a satellite in an orbit over an oblate
earth in vacuo are solved analytically by a perturbation method
the solution applies primarily to orbits of eccentricity or less
the accuracy of the solution for radial distance should then be about
and the error in angular travel about per revolution  a brief comparison
is made between theory and observation for sputniks and
   /
2395
earth oblateness in terms of satellite orbital periods  an equation
relating the earths oblateness to the anomalistic and nodical periods
and orbit parameters of a satellite is given
   /
2396
changes in the inclination of satellite orbits to the equator  an
extension of earlier investigations of march taking into account
the spread of atmospheric resistance around perigee  see also of
   /
2397
vanguard measurements give pear shaped component of earths figure
calculations indicate that the periodic variations in the eccentricity
of orbit of satellite can be explained by the presence of a third
zonal harmonic in the earths gravitational field
   /
2398
radio observations at of the first russian earth satellites  report
on observations in germany of satellites and  the various types of
amplitude and bearing fluctuations are interpreted and the wave propagation
mechanism is discussed
   /
2399
radio observations with satellite  the earlier discovery of the great
radiation belt around the earth has been confirmed and extended by
the use of improved detector equipment  this preliminary report suggests
that visible aurorae and other geophysical phenomena are closely
related to the reservoir of charged particles trapped by the earths
magnetic field
   /
2400
space vehicles satellites and missiles a symposium  verbatim report
of a symposium sponsored by the feedback control systems committee
of the american institute of electrical engineers buffalo new york
june
   /
2401
radio echoes from some invisible objects in the troposphere  a regular
scanning of the troposphere was carried out by the central aerology
observatory of the ussr from to at using a parabolic reflector and
a pulse transmitter  during the investigation radio echoes at heights
up to km were recorded  film recordings show the distribution of
echo sources as functions of height and time
   /
2402
variations in ionospheric f region characteristics  analysis of records
obtained by macquarie island geomagnetic latitude since
   /
2403
study of horizontal drifts in the f and f regions of the ionosphere
at waltair mag  the diurnal and seasonal changes of drifts in the
f region are given in detail  the reversal of direction relative
to movements at high latitudes is consistent with martyns drift theory
   /
2404
some measurements of horizontal movements in region f using widely
spaced observing stations  vertical incidence recordings at stations
some km apart were compared  the results show a correlation between
velocity magnitude and the degree of magnetic activity and a positive
height gradient of velocity
   /
2405
investigation of the inhomogeneous structure of the f region of the
ionosphere  results of vertical incidence soundings at kharkov from
june to may have shown that in of cases the reflection from the ionosphere
has a static character and that the regular diurnal and seasonal
variation of the degree of inhomogeneity of the f region does not
arise
   /
2406
geomagnetic influence on the f and f regions of the ionosphere effect
of solar activity  noon critical frequencies for the f and f layers
are examined for different seasons and levels of solar activity
it is found that the f layer exhibits a geomagnetic control at periods
of high solar activity only whilst the equatorial trough in is most
marked during periods of low solar activity
   /
2407
geomagnetic distortion of region e  an analysis of the behaviour of
the normal e region suggests that departures from the classical chapman
theory can be attributed to vertical drift of ionization resulting
from the interaction of the geomagnetic field and the sq current
system flowing in or near the e region  perturbations of under magnetically
disturbed conditions and near the auroral zone are also discussed
   /
2408
on the seat of the l currents causing geomagnetic tides  a note on
some ionospheric and geomagnetic data which support the view that
the seat of the l current system is situated in the f layer
   /
2409
a study of the morphology of ionospheric storms  a study of variations
of the maximum electron density in the f layer for the period at
stations between and geomagnetic latitude  storm time variations
and disturbance daily variations during each six hour period were
obtained and the changes of these with latitude were examined
   /
2410
a rapid method of obtaining accurate virtual heights from an ionogram
the variation of apparent vertical height with the amplitude of the
reflected signal depends on constants of the equipment  these constants
are used to construct a transparent slider which corrects for this
variation and enables virtual heights to be obtained accurately
   /
2411
the reflexion of radio waves from a stratified ionosphere modified
by weak irregularities  consideration is given to the scattered wave
which accompanies reflexion from a stratified ionosphere in which
there are weak irregularities  by considering these irregularities
to be confined to a thin layer near a given height the possibility
is examined that they might produce considerably enhanced scattering
if they were situated near the reflexion level calculated on the
basis of geometrical optics  it is found that they would not have
a very much greater effect at this level  it is also shown that if
the electron collision frequency is of the order likely to be encountered
in the real ionosphere there would be little enhancement by resonance
effects of the kind suggested by herlofson
   /
2412
irregularities in refraction of radio waves and large inhomogeneities
in the ionosphere  description of the method and results of measurements
of the vertical refraction of radio waves at in the ionosphere  the
irregularities of refraction are produced by inhomogeneities of dimensions
about km in the f region  the diurnal variation of inhomogeneities
is analysed and it is shown that their presence is related to solar
activity
   /
2413
ionospheric self demodulation and self distortion of radio waves
demodulation was observed only at low modulation frequencies  the
magnitude of the effect agreed with that predicted by theory and
was also what would have been expected from results obtained in cross
modulation experiments
   /
2414
preliminary results of an experiment to determine initial precedence
of organized electrification and precipitation in thunderstorms
it is shown that electrification of clouds begins before any radar
echo is observed this raises doubts about the assumption that precipitation
is the primary cause of charge generation
   /
2415
determination of the angle of arrival of auroral echoes  an interference
method is used at kjeller to measure the angle of arrival of auroral
echoes  as varies from to the range increases from to and it is shown
that the height of the reflection area must be km
   /
2416
horizontal motions in radar echoes from aurora  observations at saskatoon
at show a sytematic motion of echoes towards the west before midnight
and towards the east after midnight the mean velocity in either direction
showing a statistical relation to variations in the earths magnetic
field
   /
2417
new power sources for space age electronics  developments are described
in chemical nuclear and solar energy sources which are expected to
fulfil requirements for portable electrical power in space  output
characteristics of different types are summarized
   /
2418
a method for testing and establishing the rating of semiconductor
rectifiers under dynamic conditions
   /
2419
regulated power supplies  a brief review is made of various types
of stabilized power supply leading to the closed loop series regulator
for which design details are given
   /
2420
dry cells containing various aromatic c nitroso compounds as cathode
materials  the cells have a mg anode and an aqueous solution as electrolyte
performance characteristics compare favourably with those of
commercial leclanche type cells
   /
2421
self discharge reactions in lead acid batteries  in a theoretical
and experimental analysis the rates of seven different reactions
which contribute to the self discharge process have been determined
references
   /
2422
random number generator using subharmonic oscillators  the outputs
of two oscillators driven from a common source are combined in a
hybrid ring  the generator can produce random binary digits at a
maximum rate of digits sec
   /
2423
pulsed analogue computer for simulation of aircraft  a description
is given of the logical design of a computer for solving the nonlinear
differential equations encountered in the simulation of aircraft
performance under various flight conditions
   /
2424
summarized proceedings of a conference on solid state memory and
switching devices london september  some of the newer techniques
are discussed with reference to ferrite ferroelectric and superconducting
devices and magnetic thin films
   /
2425
transistors and cores in counting circuits  it is shown how square
loop magnetic cores and transistors can be combined to form noncritical
reliable counting circuits capable of handling input frequencies
up to
   /
2426
unifying design principle for the resistance network analogue  a
cell principle technique due to macneal is extended and generalized
as an illustration poissons equation is integrated over the volume
of a representative small cell in which form it is easier to appreciate
the analogy with the resistance network and to arrive at the relevant
design parameters
   /
2427
use of an electronic analogue computer with resistance network analogues
a method for solving partial differential equations of the elliptical
type is described  the method is iterative and adjustments are made
automatically by means of electronic storage elements and a switching
mechanism  some results are given
   /
2428
magnetic matrix stores  review of computer storage systems based
on ferrites with rectangular hysteresis loops
   /
2429
lens designing by electronic digital computer  different methods
of designing optical lenses by digital computer are considered in
the light of existing aberration theory
   /
2430
the dofl microelectronics program  some of the microminiaturizatio
techniques used at the diamond ordnance fuze laboratories are described
   /
2431
the micro module a logical approach to microminiaturizatio  a review
is given of the progress of miniaturization the advantages of the
micro module system the assembly of microelement components into
units with a specified electronic function are outlined
   /
2432
micro module design progress  details are given of the application
of a modular technique in the construction of a complete prototype
communication receiver and certain digital circuits for multiplex
equipment
   /
2433
test patterns for printed circuit materials
   /
2434
printed circuits applied to broad band microwave links  detailed
review of the characteristics and advantages of typical printed circuits
   /
2435
thermistors for linear temperature readings  two circuits are described
for deriving an error voltage which varies linearly with the difference
between actual and desired temperature
   /
2436
the performance of pyrolytic carbon resistors  the major factors
affecting performance are carbon film thickness moisture permeability
and thickness of protective coating operating temperature and the
quality of the ceramic substrate  the effect of these factors is
small if the carbon film has a thickness of at least a
   /
2437
realistic temperature power derating requirements for carbon composition
resistors  two derating methods are described based on statistical
analyses of load life data
   /
2438
rectangular hysteresis loop magnetic cores as switching elements
theoretical bases and experimental results are given for core switching
with voltage and current pulses
   /
2439
dielectric losses with periodic rectangular voltage pulses  application
of a different method to the solution of a capacitor loss problem
dealt ith by eisenlohr
   /
2440
elements of electronic circuits amplitude limiting
   /
2441
a general network theorem  the realization of the transmission factor
of a four terminal network with lumped circuit elements by a passive
symmetrical quadripole and a transformer is discussed
   /
2442
network characteristics  the common network transformation theorem
of griffiths and mole see of is shown to lack generality
   /
2443
matrix analysis of vacuum tube circuits  the equivalent four terminal
network for a feedback amplifier is derived and the criterion for
oscillation is deduced
   /
2444
tchebycheff approximation for loss free image parameter filters according
to cauer
   /
2445
passage of a nonlinear oscillatory system through resonance  a mathematical
analysis of a nonlinear oscillator with one degree of freedom
which can be described by a hamiltonian
   /
2446
improved low repetition rate millimicrosecond pulse generator  a
discharge line device using a vibrating reed type of mercury switch
in a suitable coaxial mounting provides pulse repetition rates of
up to cs
   /
2447
half cycle resonant delay circuit  a new circuit generating a rectangular
pulse of duration equal to the natural half cycle of an lc circuit
the principles are applicable to the generation of pulses
   /
2448
series diode increases multivibrator sensitivity  triggering sensitivity
of monostable multivibrators may be greatly increased by using a
semiconductor diode as a series nonlinear element in the feedback
loop  good stability can be achieved
   /
2449
multivibrator circuit using pnp and npn junction transistors  details
of an improved circuit giving low output impedance and small power
consumption
   /
2450
analysis and design of a transistor blocking oscillator including
inherent nonlinearities  the nonlinear differential equations governing
circuit performance are derived  analogue and digital computer solutions
yield pulse responses in agreement with experimental results
   /
2451
ten pulse amplitude discriminator  a pulse height discriminator has
been developed which is capable of operating at repetition rates
up to  it accepts positive input pulses with a threshold adjustable
from to  the output signal is of constant shape and amplitude  the
circuit is described and test results are given
   /
2452
a new type of ring counter  a system is described using separate
eccles jordan circuits in which any number of stages may be employed
advantages over other systems are indicated
   /
2453
how ring counters work  basic thyratron and thermionic valve circuits
are described and reference is made to the use of the circuit as
an electronic rotary switch
   /
2454
dividing wide frequency bands  a regenerative circuit is described
which will divide a sinusoidal input frequency by two over a wide
frequency range
   /
2455
some properties of mathieu and related functions exemplified by the
regenerative modulation process  a frequency divider using regenerative
modulation can be used as an analogue method for the solution of
mathieu and meissner differential equations  an experimental frequency
divider is described and a number of waveforms obtained with it are
reproduced
   /
2456
the measurement of the time delay of ultrasonic delay lines
   /
2457
quartz delay lines for radar systems  two lines are briefly discussed
the electromechanical type in which a silica or quartz bar is used
in conjunction with one or two quartz crystal transducers and the
rectangular or polygon plate type applicable to ultrasonic frequencies
delay times from to are obtainable at low power levels
   /
2458
band pass amplifiers their synthesis and gain bandwidth factor  seven
types of band pass amplifier are investigated and compared and their
design formulae are given
   /
2459
using cascading charts  charts are given for determining the number
of transitionally coupled double tuned amplifier stages needed to
provide a required gain and bandwidth  two cases are considered equal
damping of primary and secondary windings one sided damping
   /
2460
audio amplifier design cuts plate dissipation  an auxiliary signal
at ultrasonic frequency applied to the grid reduces anode dissipation
at low signal levels
   /
2461
overloading effects with cathode compensation  further details on
cathode compensation of a video stage with rc anode load including
compensation for an rc load in the anode of the preceding stage
   /
2462
application of magnetic amplifiers to engineering problems  the various
types of magnetic amplifier connection are discussed and a typical
application of each is presented
   /
2463
design of an emitter current controlled common emitter transistor
if amplifier stage  input and output impedances and their influence
on the bandpass characteristics are studied  the stage is suitable
for broadcast receivers
   /
2464
transistorized pulse amplifier  instead of pulse transformers drift
transistors with high cut off frequencies are used in diode logic
circuits  with input pulses the total rise and fall times are less
than the delay between input and output pulses varying from to according
to load conditions
   /
2465
dc operational amplifier with transistor chopper  description of
a drift compensated dc amplifier with which an accuracy of can be
achieved in airborne analogue computers  vol
   /
2466
weak field nuclear magnetic resonance maser
   /
2467
study of a weak field maser type self oscillator  characteristics
of the maser described in below are discussed
   /
2468
proposal for a staircase maser  a proposal for obtaining amplification
at approximately twice the pump frequency in which adiabatic fast
passage is used to invert successively the and levels of a three
level system
   /
2469
tunable l band ruby maser  the product of voltage gain and bandwidth
was measured over the frequency range in a maser at temperatures
of and
   /
2470
low frequency prototype travelling wave reactance amplifier  the
circuit of an amplifier with special junction diode nonlinear capacitors
in a semidistributed transmission line is described  performance
data at a signal frequency of show midband gains of with overall
effective input noise temperatures of about
   /
2471
vacuum diode microwave detection  a new wide band discriminator
a transmission line arrangement for frequency discrimination is described
output is linear for frequency deviations up to  two practical
circuits are given with centre frequency and respectively
   /
2472
surface charges produced on insulators by short and long time ionization
   /
2473
note on the motion of electrons and holes in perturbed lattices
a new set of orthogonal localized functions is discussed  the functions
bear the same relation to the functions of luttinger and kohn as
the wannier functions bear to the bloch functions  the new functions
are used to give an alternative derivation of the effective mass
equation
   /
2474
thermoelectricity at very low temperatures  review of theory and
discussion of recent experimental work at temperatures below
   /
2475
a possible mechanism of the potential variation of the joshi effect
   /
2476
a method of studying the electrical recovery of a gas after a pulse
discharge  a method devised for a triggered discharge as in a thyratron
   /
2477
on the temperature of electrons in a plasma in a variable electric
field  the investigation shows that the electron gas can exist in
two stable states with different temperatures transition from one
state to another occurs at certain critical values of the field and
is followed by a considerable change in the electron temperature
a particular type of hysteresis is noted in the dependence of the
electron temperature on the field amplitude and frequency  expressions
for the complex conductivity of the plasma are also derived
   /
2478
measurement of the attachment of slow electrons in oxygen  drift
tube measurements are extended into the termal energy range a three
body attachment process is indicated
   /
2479
theory of excited plasma waves  the excitation of oscillations in
a uniform plasma by an injected electron beam is considered and the
frequency phase velocity and time rate of growth of the excited waves
are derived as functions of the wave number
   /
2480
nonlinear electron oscillations in a cold plasma
   /
2481
production of two temperatures in an ionized gas in a magnetic field
if the electrons radiate a considerable part of their energy in a
time short compared to the relaxation time of the gas the electronic
temperature will differ considerably from the ionic temperature
   /
2482
a consistency condition for electron wave functions
   /
2483
geometrical theory of diffraction in inhomogeneous media  the theory
developed by an extension of fermats principle and considering smooth
convex bodies is applied to the calculation of the field of diffracted
rays
   /
2484
asymptotic theory of diffraction in inhomogeneous media  problems
discussed in above are treated here as boundary value problems  they
are solved exactly and the solutions are expanded asymptotically
for high frequencies
   /
2485
a note on the scattering of a plane electromagnetic wave by a small
thin walled cylindrical dielectric tube
   /
2486
nonreciprocal electromagnetic wave propagation in ionized gaseous
media
   /
2487
investigation of relaxation in magnetic resonance by the method of
forced transient precession  a method is described for measuring
directly the relaxation time in liquids
   /
2488
radiation damping in nuclear magnetic resonance  observations on
a nuclear two level maser have demonstrated the effect of radiation
damping obtained by flipping the magnetization through about
   /
2489
wide rf level rf unit for an nmr spectrometer  this unit makes use
of a crystal controlled oscillator for frequency stability and positive
feedback to increase the effective q of the sample rf coil  the circuit
is well suited to saturation studies and relaxation time measurements
in nuclear magnetic resonance investigations
   /
2490
effective ferrimagnetic resonance parameters with gilbert type relaxation
terms
   /
2491
observation of the overhauser effect in a gas in the presence of
a solid paramagnetic material  note of nuclear magnetic resonance
measurements made on propane gas in diphenyl picryl hydrazyl
   /
2492
the influence of the saturation of paramagnetic resonance absorption
on the faraday effect  experimental investigations on a crystal of
nd and discussion of results
   /
2493
weak field nuclear magnetic resonance maser  description of an instrument
for nuclear magnetic resonance investigations based on proton
spin resonance in circulating benzene
   /
2494
method of treating zeeman splittings of paramagnetic ions in crystalline
fields
   /
2495
the royal greenwich observatory  reference is made to the national
time service associated equipment and land line links with other
standards
   /
2496
low energy corpuscular radiation at high latitude  an explanation
based on an acceleration mechanism
   /
2497
origin of the radiation near the earth discovered by means of satellites
   /
2498
radiation around the earth to a radial distance of km  radiation
measurements made during the flight of pioneer on december are discussed
and a brief description is given of the two geiger muller detector
tubes used and the associated telemetry equipment
   /
2499
anomalous night time reception of a major solar radio burst  a report
of a noise burst received on five different arrays operating on frequencies
between and at march in florida  possible modes of propagation
are discussed
   /
2500
time relationship of metre wave and cm wave bursts  metre wave bursts
have an average delay of min the delay being less for bursts of small
apparent diameter
   /
2501
radar echoes from venus  report on tests made on and february using
specially coded pulse trains at and a maser type amplifier for reception
   /
2502
cosmic ray increases associated with solar flares  data from a neutron
monitor for the years have been studied
   /
2503
characteristics of solar outbursts to excite geomagnetic storms
for major outbursts a pronounced first part before the time of maximum
flare is related to short wave fade out while a large second part
will cause a geomagnetic storm  it is concluded that the second part
of the outburst provides evidence of a corpuscular cloud
   /
2504
fluctuations of temperature accompanying the solar eclipse  during
the eclipse there was a depression of the rms value of the fluctuations
which was accompanied by a temperature inversion with a steep gradient
as the eclipse passed the maximum blackout period  the rms value
of the temperature fluctuations between two points vertically separated
was found to increase with diminishing inversion and to continue
to increase as the gradients changed from positive to negative values
   /
2505
some remarks on the interaction of solar plasma and the geomagnetic
field  an explanation of the small scale of magnetic disturbances
on the earths surface is that currents flow in plasma sheets and
move along the curved magnetic lines of force  these sheets are distant
less than one earths radius from the surface and would produce perturbation
fields consistent with the size and direction necessary to explain
storm time geomagnetic variations
   /
2506
preliminary report on the effect of the solar eclipse on april on
the geomagnetic field  the changes in the d and h components are
consistent with the decrease in e layer conductivity z component
changes are influenced by earth currents
   /
2507
effect of the solar eclipse on the geomagnetic fld and earth currents
   /
2508
the suns artificial planet  general scientific information based
on a russian report of the space rocket launched on january
   /
2509
two atmospheric effects in the orbital acceleration of artificial
satellites  a discussion of oscillations in orbital acceleration
and the variations of orbital acceleration with angular distance
of the perigee from the sub solar point
   /
2510
atmospheric tides and earth satellite observations  harmonic tidal
waves are suggested as the cause of the major anomalies in orbital
observations this explanation differs from that of groves of may
who comments in reply
   /
2511
the igy optical satellite tracking program as a source of geodetic
information  a note on the visual and photographic tracking program
and the subsequent computations
   /
2512
a new value for the earths flattening derived from measurements of
satellite orbits  data obtained from observations of and have been
combined and give a value for the earths flattening of  see also
of march
   /
2513
determination of satellite orbits from radio tracking data  a computer
program has been developed which permits an approximate determination
of a satellite orbit from a minimal amount of tracking data
   /
2514
observations of sputnik  radio observations of satellite for the
period july are tabulated
   /
2515
recordings of transmissions from the satellite at the antenna laboratory
the ohio state university  irregularities in signals are attributed
to polarization effects caused by variations in magnetic field near
the observing point  some periodic fading may be caused by a defect
in the satellite aerial
   /
2516
irregularities in the density of the upper atmosphere results from
satellites  results of observations of earth satellite orbits indicate
that irregularities in air density especially at heights between
and tend to recur at intervals of about days
   /
2517
deduction of ionospheric electron content from the faraday fading
of signals from artificial earth satellites  a method is described
for determining horizontal variations in the ionosphere both above
and below maximum ionization  results are compared with values of
electron content deduced from ionograms
   /
2518
recording radio signals from earth satellites  a method is described
for presenting simultaneously on moving film the information necessary
for doppler frequency shift measurements for frequency sampling and
for the study of signal intensity variations
   /
2519
models of the atmospheric radio refractive index
   /
2520
geophysical effects associated with high altitude explosions  effects
likely to be associated with high altitude explosions are discussed
and related to observations of a nuclear and a chemical explosion
   /
2521
observations of intense ionization of long duration below km altitude
after some strong solar flares
   /
2522
turbulence in the upper atmosphere  ionospheric irregularities are
studied in terms of turbulence theory  the calculated scales of the
irregularities and their random velocities are compared with experimental
observations
   /
2523
sporadic e and the f layer  a comparison of curves of e percentage
time with curves giving seasonal fluctuations of f layer ionization
for four stations in both hermispheres indicates that sporadic e
may be caused by a downward drift of f ionization
   /
2524
a theoretical consideration of the electron and ion density distributions
in the lower portion of the f region  assuming that the photoionization
processes in the ionosphere are the physics of the lower f region
can be explained fairly well  the appearance and disappearance of
the f layer with solar zenith angle and solar activity can be understood
no values of reaction coefficients can be found which are consistent
with both the ion density distribution in the ionosphere and laboratory
estimates of the coefficients
   /
2525
occurrence of giant travelling ionospheric disturbances at night
disturbances previously thought to be confined to winter daylight
hours have been observed on night ionosonde records  characteristics
of the phenomenon are discussed
   /
2526
structure and movement of large inhomogeneities in the ionospheric
f layer  simultaneous measurements have been made using three receivers
km apart of the phase and angle of arrival of waves reflected from
the f layer  the size and shape of inhomogeneities and drift velocities
have been calculated
   /
2527
a new ionospheric phenomenon  report of an isolated event recorded
at jodrell bank at about on march by five separate receivers each
monitoring various sectors of the sky on slightly different frequencies
near  a large increase of the noise level was recorded by three receivers
a small increase by another and a decrease by another
   /
2528
radio reflexions from the moon and solar corona  the formula for
the rotation of the plane of polarization given by daniels and bauer
of is revised for the case when with low solar activity the electron
density in the ionosphere has decreased and the electrons in the
space around the earth cannot be neglected
   /
2529
a study of noon f ionization in relation to geomagnetic coordinates
earlier work of bhar of has been extended to cover data collected
between and an analysis of which indicates that for constant the
noon ionization varies with magnetic dip and geomagnetic latitude
the shape of the curve is related to the sunspot cycle and shows
two maxima spaced asymmetrically on each side of the geomagnetic
equator
   /
2530
ionospheric heating by hydromagnetic waves  the dissipation of hydromagnetic
waves in the ionosphere causes heating this heating is greatest
between heights of and km  it appears that the heating only becomes
important during magnetic storms it may explain the lifting of the
f region and the decrease in critical frequency during these periods
hydromagnetic heating cannot however explain the variations in the
horizontal component of the earths field during the main phase of
magnetic storms
   /
2531
effect of magnetic activity on drifts of the f region  an analysis
of observations made at waltair shows an approximately linear decrease
of mean drift speed with increase of magnetic activity in the range
   /
2532
sporadic e at vhf in the usa  the occurrence of sporadic e propagation
in the years on the cedar rapids sterling path at frequencies near
and has been analysed  the dependence of the received power on time
of day season of year sunspot cycle and frequency has been studied
a relation between oblique signal intensity and vertical incidence
data has been found
   /
2533
on the swf phenomenon dellinger effect and in the world wide distribution
assuming a chapman distribution of ionization for the d region
it is shown that is a function of solar zenith angle and magnetic
latitude while the increase of during a sudden ionospheric disturbance
depends on solar zenith angle only  observational results are analysed
and the effective factor by which solar radiation is increased during
a sid is estimated
   /
2534
ionospheric reflection coefficients at vlf from sferics measurements
the magnitude of the ionospheric reflection coefficient as a function
of ff frequency is calculated from individual spectral analysis of
the ground wave and the once reflected sky wave  results are compared
with those obtained using an ionospheric model  the success of the
method depends upon the accurate location of the source and the correct
selection of strokes which contain only appreciable vertical currents
in the discharge column
   /
2535
diurnal change of ionospheric heights deduced from phase velocity
measurements at vlf
   /
2536
igy observations of f layer scatter in the far east
   /
2537
auroral activity at low latitudes  spectroscopic observations made
in southern france and at tamanrasset during are described
   /
2538
movement of auroral echoes and the magnetic disturbance current system
a brief review of the findings of other investigators and a report
of observations made at invercargill new zealand on  a preliminary
analysis indicates that the ionization giving rise to vhf radar echoes
occurs in the most intense portion of the disturbance current system
and that the observed movements of electrons can account for the
magnitude of the disturbance vector
   /
2539
whistler mode echoes remote from the conjugate point
   /
2540
scientific uses of earth satellites
   /
2541
the american miniature nuclear generator snap  a note on a power
supply system for telemetry apparatus in a space rocket  the decay
energy of a radioactive po capsule is converted directly to electrical
energy by means of thermocouples giving an output of with efficiency
   /
2542
a transistor stabilized supply to feed an electromagnet used for
nuclear resonance studies  a circuit is described for a supply with
current stabilized to parts in
   /
2543
zener diodes stabilize tube heater voltages  typical applications
of zener power diodes to the regulation of ac and dc heater supplies
are described
   /
2544
internal resistance of dry cells  a description of a simple nondestructive
pulse technique for investigating the effect of a momentary or
continuous discharge on internal resistance  for a more detailed
account see
   /
2545
the design of a standard block for a digital computing system  logical
theory design considerations and practical circuit of a block based
on alloy junction transistors operating at frequencies up to
   /
2546
binary multiplication in digital computers  shows how many steps
can be eliminated from the usual process of multiplication by computer
   /
2547
computation of sin n cos n and using an electronic computer
   /
2548
rotating disk function generator for analogue computers  a variable
radius revolving lamina modulates the light incident upon the cathode
of a photomultiplier tube to produce a required voltage time function
   /
2549
a design for an automatic graph plotter  transistors and printed
circuits are used in equipment based on digital techniques  points
may be plotted at a rate of three per second with an accuracy within
   /
2550
magnetic core matrices for logical functions  some applications of
cores having a square hysteresis loop
   /
2551
the design of biased diode function generators  relations between
the number and spacing of diode sections to give minimum error are
derived
   /
2552
recent advances in potted and printed circuits  the various potting
resins are described in relation to the variation of properties with
different proportions of hardener and the effects on the parameters
of the potted components  the causes of failure of potted circuits
are discussed  design problems in the use of printed circuits are
examined with particular reference to questions of conductor thickness
and spacing  a method of sealing printed circuits by a thin polysulphide
rubber layer which is sprayed or brushed on is described
   /
2553
thermionic integrated micro modules  the construction and application
of microminiature heaterless valves resistors and capacitors using
titanium and ceramic materials are described
   /
2554
the transpolarizer an electrostatically controlled circuit impedance
with stored setting  the device operates by the controlled transfer
of polarization through two or more ferroelectric dielectric sections
in series
   /
2555
an electronic timer with voltage control of setting  a new grid controlled
bootstrap circuit with common cathode trigger provides accurately
controlled time delays up to about seconds
   /
2556
microwave switching by crystal diodes
   /
2557
tantalum printed capacitors  description of the structural features
and characteristics of capacitors using sputtered ta films as the
base for the anodized oxide film with evaporated metal counter electrodes
   /
2558
the surface enlargement of aluminium for electrolytic capacitors
various chemical and electrochemical methods are described and compared
and details are given of a method of measuring the increase in surface
area achieved
   /
2559
general solution of the symmetric iterative analysis of asymmetric
passive linear quadripoles  the asymmetric quadripole is divided
into two symmetric quadripole sections which can be treated by iterative
matrix methods
   /
2560
investigation of an apparatus for recording atmospherics  an analysis
of an integrating circuit with a long time constant and its response
to a series of pulses
   /
2561
a topological nonreciprocal network element  the element is a three
terminal device which may be used with physical elements immittances
to model the more complex nonreciprocal devices
   /
2562
traditors a new class of nonenergic nonlinear network elements  from
an analysis based on the lagrangian dynamical equations a class of
nonlinear multiport elements is defined which are characterized by
the property of neither dissipating nor storing but only transferring
energy
   /
2563
transmitting frequency converter in which gold or silver bonded diode
is used
   /
2564
one aspect of minimum noise figure microwave mixer design
   /
2565
a cryogenic oscillator  a relaxation process based on the transition
between the superconducting and conducting phases of a film is described
oscillations at frequencies around have been obtained
   /
2566
a sine wave generator with periods of hours  an inverse function
generator based on the difference amplifier is examined and examples
of its use are considered in a logarithmic voltmeter and for sine
triangle waveform transformation  triangle sine transformation can
be achieved by negative feed back a vlf triangular waveform obtained
from a cr circuit and relay is thus converted to an accurate sine
wave without transients
   /
2567
tube transistor hybrids provide design economy  a bistable cathode
follower and four stage ring counter are described  the transistors
appear in the cathode circuits of the valves
   /
2568
physical principles of avalanche transistor pulse circuits  a model
for the transistor is defined in terms of charge variables and the
physical parameters of the device  the transient performance of the
model is calculated by focusing attention on the minority carrier
charge stored in the base region and the influence of base width
modulation upon this stored charge  in the charge formulation of
the problem the physical details of the avalanche multiplication
process need not be considered multiplication is accounted for by
the boundary conditions which it imposes upon the stored charge
good agreement has been obtained between calculated and experimentally
observed data for a simple avalanche transistor relaxation oscillator
   /
2569
time to pulse height converter  a circuit is described for deriving
pulses the amplitudes of which decrease linearly with time
   /
2570
linear gate of duration  diodes with a recovery time are used in
a coincidence circuit
   /
2571
a torsional magnetostrictive delay line  an application of the wiedemann
effect using toroidal coil transducers
   /
2572
pulse amplification using impact ionization in germanium  some aspects
of the phenomena of impact ionization in an impurity doped semiconductor
at are described  control of the breakdown process is used to obtain
pulse amplification in the millimicrosecond range using two and three
terminal devices
   /
2573
reducing distortion in class b amplifiers  linearization is accomplished
by a nonlinear compensation network containing diodes  the calculations
for an af amplifier with distortion are described
   /
2574
grounded grid power amplifier design  a graphical design procedure
is described using a disk seal valve type as an example
   /
2575
single ended amplifiers for class b operation  a transistorized high
fidelity push pull amplifier is described in detail
   /
2576
single ended amplifiers for class b operation  a transistorized high
fidelity push pull amplifier is described in detail
   /
2577
designing high quality af transistor amplifiers  a seven stage amplifier
is described  one transistor push pull  an af output stage in which
the biasing condition is controlled by the rectified output
   /
2578
molecular oscillators and amplifiers  the principle and operation
of molecular beam oscillators and amplifiers are described with reference
to the ammonia beam maser  molecular amplifiers based on paramagnetic
crystals give a wider pass band and a higher output power than the
molecular beam type  the frequency stability achieved is within one
part in
   /
2579
zero field masers  solid state three level masers operating with
zero magnetic field are shown to be feasible and to have advantages
over magnetic field masers in many applications  the requirements
of the working substance are discussed and it is found that compounds
of cr fe ni and gd should be suitable  diagrams and tables of maser
properties of selected compounds are given on the basis of present
knowledge a number of amplifying frequencies between and should be
available  the range of suitable compounds which has been studied
is very small and should be extended
   /
2580
role of double quantum transitions in masers  conditions are found
in which the operation of a three level maser is governed by the
double quantum process and does nor require a true pumping stage
such a case although realizable in practice may be of doubtful technical
applicability
   /
2581
travelling wave solid state masers
   /
2582
a maser amplifier for radio astronomy at x band  the design and operating
characteristics of a maser radio meter for use in radio astronomy
at wavelength are discussed  the operating system which is described
has a bandwidth of and an input noise temperature including background
radiation into the antenna of about k  an rms fluctuation level of
about is attained using an averaging time of seconds  a discussion
of the factors determining the sensitivity of such devices is presented
   /
2583
two level maser materials
   /
2584
theory of three level paramagnetic masers  quantum theory  amplification
and oscillation  output noise power spectrum  noise figure  discussion
   /
2585
parametric amplifier receives space signals  signal amplification
was in la band and pump frequency in x band giving a noise factor
of db and bandwidth  using a paraboloid diameter feet the fraction
of a watt radiated by pioneer was received at miles
   /
2586
microwave parametric amplifiers and convertors  the inherent gain
noise and bandwidth characteristics of basic circuits are discussed
and a brief description is given of a ladder network converter in
which the output frequency is higher than the pumping frequency
   /
2587
circuit conditions for parametric amplification  correction of an
error in valdes paper
   /
2588
simplified product detector design  a circuit is described for a
pentagrid converter which may be self excited or separately excited
and which has an inter modulation balance adjustment to reduce rectification
effects
   /
2589
the modulator as a phase detector  a note on the error due to a finite
switching voltage applied to a shunt modulator
   /
2590
solution of maxwells equations in terms of a spinor notation the
direct and inverse problem  the use of spinor notation enables the
solution to be obtained in more compact form than does vector notation
   /
2591
the quantum mechanical theory of the dielectric orientation polarization
of gases part the static orientation polarization of a dipole gas
consisting of symmetric spin molecules
   /
2592
noise theory for hot electrons  nyquists theorem is extended to the
case in which the distribution of electrons is disturbed by a steady
electric field
   /
2593
transient behaviour of the ohmic contact  the behaviour of ohmic
injecting contacts is analysed for transient currents at a fixed
voltage  these occur when the free carrier density in the solid is
changed by some exciting agent as in photoconductivity or bombardment
induced conductivity
   /
2594
the calculation of the field in a homogeneous conductor with a wavy
interface  analysis showing that the perturbation of an em field
in the conductor due to the ripples is proportional to their amplitude
   /
2595
penetration of transient electromagnetic fields into a conductor
theory for a uniform electric field abruptly applied to a plane boundary
   /
2596
on the theory of the peltier heat pump  the figure of merit for a
single stage pump is optimized in the region of partial fermi degeneracy
   /
2597
the space charge field emission hypothesis applied to hayashi data
on discharges through gases
   /
2598
concerning the nature of the aberrations in electron sheet beams
a power series expansion is used to derive expressions for the aberrations
up to the third order in electron sheet beams subject to purely
electrostatic focusing  four purely geometric aberrations and four
aberrations due to chromatic effects are found
   /
2599
new hollow cathode glow discharge  current densities of can be obtained
with a cathode consisting of a refractory metal with a spherical
cavity  in neon stable characteristics at a few milliamperes are
obtained
   /
2600
new experimental results for plasma electron oscillations  study
of oscillations in low pressure mercury vapour discharges with plane
oxide coated cathodes
   /
2601
a lagrangian formulation of the boltzmann vlasov equation for plasmas
a variational principle is found which leads to a new formulation
of the problem of small oscillations about equilibrium
   /
2602
wave mechanical correction of the richardson dushman emission formula
an attempt is made to overcome the discrepancies between the spin
corrected theory of thermionic electron emission and empirical results
   /
2603
rose einstein lattice gases equivalent to the heisenberg model of
ferro antiferro and ferri magnetism  a hamiltonian is presented that
has the form of a finite series of bose operators and is equivalent
to the heisenberg model
   /
2604
formation of discontinuities in classical nonlinear electrodynamics
   /
2605
polarization and angle dependence of the reflection factor of absorbers
for centimetre electromagnetic waves  the dependence of the reflection
factor on the angle of incidence and plane of polarization of em
waves is investigated for various types of absorbers and results
are confirmed experimentally
   /
2606
transients in conducting media  the effect of incident wave fluctuations
on the mean intensity distribution near the focal point of a lens
an extension of chernovs analysis of to the case of fluctuations
of arbitrary amplitude
   /
2607
the kirchhoff young theory of the diffraction of electromagnetic
waves  a transformation is discussed which facilitates the evaluation
of kirchhoffs double integrals
   /
2608
on propagation of waves in slightly rough ducts  mathematical treatment
of acoustic and em wave propagation assuming that the heights of
the roughness peaks are small compared to the average separation
of the duct walls
   /
2609
the propagation of a variable electromagnetic field in a stratified
anisotropic medium  computation of the field on the surface of an
anisotropic conducting medium due to a dipole lying in the surface
see also of
   /
2610
on the propagation of electromagnetic waves in a medium with appreciable
spatial dispersion  brief description of a method more detailed then
that of ginzburg of april in which expansions are obtained for direct
and inverse dispersion  it is shown that in cubic crystals inclusion
of the spatial dispersion leads to a weak anisotropy of the index
of refraction
   /
2611
a general theory of magnetic double resonance  the theory describes
a system consisting of two interacting different species of spin
one being saturated by a strong resonant radiation field and the
other being detected by a weak field  see also
   /
2612
multiple quantum transitions in nuclear magnetic resonance
   /
2613
the application of magnetic resonance to solid state electronics
a description of the basic principles and techniques and an outline
of some recent applications
   /
2614
excitation of spin waves in an antiferromagnet by a uniform rf field
it is possible to excite spin waves in an antiferromagnet by a uniform
rf field provided that spins on the surface of the specimen experience
anisotropy interactions different from those acting on spins in
the interior
   /
2615
exchange effects in ferromagnetic resonance  a single dispersion
law for transverse em waves and for spin waves is derived which takes
account of both relativistic and exchange interactions
   /
2616
paramagnetic electron resonance induction  preliminary note on investigations
of induced emission at paramagnetic resonance  was used at
room temperature and a wavelength of cm
   /
2617
ferrimagnetic resonance modes in spheres  the magnetostatic solutions
of ferrimagnetic resonance in ferrite spheres are briefly derived
some experimental results are compared with the theory
   /
2618
role of double quantum transitions in masers
   /
2619
form effect in linear magnetostriction
   /
2620
electron interaction in solids  characteristic energy loss spectrum
the characteristic energy loss spectrum is analysed with the aid
of the dielectric formulation of the many body problem
   /
2621
improved measurements of the positions of intense radio stairs  observations
have been made at using the cambridge radio telescope as a
crossed axis interferometer  see also of edge et al
   /
2622
the extension of solar radio spectroscopy to decametre wavelengths
preliminary report on spectrographic investigations in the frequency
range
   /
2623
on short periodic variations in solar noise storms on  days of enhanced
solar radiation on in june july and august are investigated by an
autocorrelation method in a search for short periodic variations
with repetition times between and min  results indicate that some
noise storms are characterized by periodic variations with repetition
times differing from day to day while other noise storms exhibit
no periodic variations  it is possible that a specific noise storm
area retains its characteristics of short periodic variations in
radio emission for a solar rotation or longer
   /
2624
on the fine structure of solar bursts in the range and their drift
in frequency  high speed records have been obtained simultaneously
on and with a twin channel receiver at the harestua solar observatory
during the period february september  an analysis of the records
shows that of the bursts occur first on the lower frequency first
first on the higher frequency and simultaneously  the results are
discussed and the receiving equipment is described
   /
2625
a new high resolution interferometer for solar studies  the device
is essentially aa two element interferometer with the two aerials
aligned equatorially which permits use far from the median plane
and gives a resolving power of the order of alon et al
   /
2626
a high resolution survey of the andromeda nebula at  a report of
observations made with the jodrell bank radio telescope
   /
2627
a high resolution survey of the coma cluster of galaxies at
   /
2628
the scattering of radio waves in the solar corona  an account is
given of measurements carried out each june during the period of
the radio emission from the crab nebula at wavelengths of and m
results indicate a pronounced sunspot cycle variation in certain
regions of the corona a scatter anisotropy and the presence of refraction
effects in addition to scattering  see also of
   /
2629
theory of the radio echo meteor height distribution in a non isothermal
atmosphere  the height distribution of echoing points of shower and
sporadic meteors belonging to a homogeneous velocity group is calculated
for a model atmosphere whose scale height is a linear function of
height  experimental cut off and the theoretical approximations involved
limit the accuracy with which actual scale height and density may
be found from observed meteor trails
   /
2630
elevation height and electron density of echoing points of meteor
trails  these parameters may be evaluated by the continuous operation
of cw equipment on mcs  at least of all echoes are found to be distorted
the electron density distributions are in qualitative agreement
with known meteor mass distributions and trail shapes
   /
2631
solar activity and transient decreases in cosmic ray intensity
   /
2632
a new theory of the solar corona  it is proposed that the solar corona
consists of trapped charged particles moving in the magnetic fields
of the sun  experimental data are discussed in terms of this model
   /
2633
disturbances of the earths magnetic field considered as relaxation
variations  records of the horizontal magnetic component at elisabethville
and elsewhere show relaxation processes analogous to post disturbances
of magnetic storms and subject to the day recurrence tendency
   /
2634
possible causes of geomagnetic fluctuations having a sec period
comment on of may daniels  short and long period oscillations sometimes
preceding but more often accompanying a main train of magnetic activity
are described  they are considered to be associated and of electromagnetic
origin
   /
2635
geographical variations in geomagnetic micropulsations  significant
differences consistently occur in simultaneous data obtained at
stations miles apart
   /
2636
on a possible auroral origin of certain geomagnetic pulsations
   /
2637
the relation between the sudden disappearance of filaments and magnetic
storms  an analysis of records shows a correlation between the sudden
disappearance of filaments close to the suns central meridian and
magnetic disturbances
   /
2638
green coronal line intensity and geomagnetism  statistical analysis
indicates a minimum in geomagnetic activity following the central
meridian passage of regions of high green line intensity
   /
2639
laws of motion of an earth satellite  the principles of multistage
rocket flight are considered and formulae for rocket velocity are
derived  tables give the satellite velocity and duration of flight
for heights up to km
   /
2640
a discussion on observations of the russian artificial earth satellites
and their analysis  the he text is given of fifteen papers discussed
at a meeting in london november  these include results obtained using
radio telescopes and interferometers doppler recorders and direction
finding and field strength measuring equipment  applications are
made to the computation of orbit parameters  see also of for a similar
discussion
   /
2641
observations on the ussr earth satellites and the study of radio
wave propagation  measurements of bearing angle of elevation and
doppler frequency shift were made at and  the observed phenomena
could be explained in terms of existing knowledge of ionospheric
propagation  the derivation of orbital parameters from the observations
is discussed
   /
2642
a type of variation of the signal strength from  fluctuations of
signal strength relative to the satellite position in orbit indicate
that the satellite produces heavily ionized tracks of very long lifetime
observations have been made to test this hypothesis and results
are given
   /
2643
diurnal lapse of signals from sputnik  a brief note dated april states
that systematic observations have established that pulse modulation
is present only when the satellite is in sunlight  on very close
transits the cw signal can be detected with sufficient strength to
record the doppler shift
   /
2644
density of the atmosphere at heights between km and km from analysis
of artificial satellite orbits
   /
2645
fluctuations in the brightness of the second artificial earth satellite
these brightness fluctuations are explained by the rotation of the
satellite on its axis its maximum brightness corresponding to its
greatest cross section as seen by the observer  a graph shows these
brightness variations as recorded by the odessa observatory
   /
2646
the antipodal reception of sputnik  the mechanism of the propagation
of waves around the earth within the ionospheric layers is discussed
and the best conditions for antipodal reception are deduced  it is
concluded that at stanford calif the best conditions for frequent
reception occur from the south east during summer afternoons  this
is in agreement with observations
   /
2647
satellite measured radiation  the relevance of atomic change exchange
processes to the nature of the radiation belt is noted
   /
2648
some results of investigations on cosmic rays using artificial earth
satellites  the intensity variations of cosmic rays as recorded during
the flight of the second sputnik are shown  there were no appreciable
corresponding variations at ground level
   /
2649
corpuscular radiation and the acceleration of artificial satellites
observations of satellites and more accurate values of acceleration
have been calculated at twice the original resolution of august
correlation with cm solar radiation is higher for than probably due
to greater observational accuracy  an increased acceleration of at
the time of two major geomagnetic disturbances following flares indicates
the effect of corpuscular radiation on atmospheric density at
the km level
   /
2650
on the existence of a strong magneto ionic effect topside of the
f maximum of the kennelly heaviside layer  observations of the faraday
effect in signals from artificial satellites showed noticeable magneto
ionic effects at altitudes up to km
   /
2651
parametric amplifier receives space signals
   /
2652
radio reflections from satellite produced ionization  observations
have been made on frequencies of and two very different effects obtained
on both and are described
   /
2653
cosmic ray instrumentation in the first us earth satellite  the instrumentation
was designed for conservation of electrical power and for
stable and reliable operation over a wide range of temperatures
   /
2654
some results of investigations of the upper atmosphere  vertical
rocket investigations carried out in ussr between and showed that
contrary to established opinion above the e layer there is only a
very shallow minimum in electron density  the electron density increases
up to with a maximum at km and then slowly decreases so that at km
the density is electrons cm
   /
2655
a theoretical study of the dynamical structure of the ionosphere
a comprehensive survey of the modification to chapman theory which
are necessary to explain the actual behaviour of the ionosphere  both
the large f layer anomalies and the smaller ones for the e and f
layers are discussed  over references
   /
2656
conditions in the outer ionosphere  it is found that the electron
concentration in the outer ionosphere decreases with the height considerably
less rapidly than it increases at lower levels  the values
obtained show that at the concentrations of electrons and neutral
particles are of the order of and per cm respectively
   /
2657
investigation of the equatorial electrojet by rocket magnetometer
two layers of electrical current were detected one existing near
an altitude of and the other about higher
   /
2658
geophysical effects of high altitude nuclear explosions  a report
of observations made at hiraiso observatory on and august  fade outs
on frequencies between and an enhancement of atmospheric noise at
have been recorded  these effects are attributed to an increase in
d layer ionization extending over much greater distances than had
previously been envisaged
   /
2659
sporadic e region ionization spread f and the twinkling of radio
stairs  kinematic instability in the ionization gradient of a medium
drifting across a magnetic field is considered to be responsible
for the three phenomena
   /
2660
the effect of sudden ionospheric disturbances sids on pulse reflections
from the lower ionosphere  during a typical large sid associated
with a class or class flare the increase in ionization might vary
from at km through at km to unity at km  the amplitude recovery
of the e layer echo lagged about min behind the recovery of the lower
echoes around km  at all heights below km echo recovery occurred
simultaneously
   /
2661
rocket measurements of absorption in the lower ionosphere  results
are given of measurements of the field strength of one long wave
and two medium wave transmitters  the d layer minimum height is about
km and medium wave observations indicate maximum absorption at km
the attenuation being km for normal incidence
   /
2662
refraction of extraterrestrial radio waves in the ionosphere  expressions
are derived for estimating ionospheric refraction at low frequencies
horizontal gradients of electron density are considered  positions
of a discrete source obtained from observation at after applying
corrections for refraction are within a few minutes of arc of the
observed position at mcs
   /
2663
simultaneous occurrence of subvisual aurorae and radio noise bursts
on  records show that there is a correlation between aurorae and
noise bursts but anomalies exist which cannot be explained satisfactorily
   /
2664
auroral isochasms  observed isochasms and projections of circles
in the equational plane along the geomagnetic lines of force are
compared
   /
2665
investigation of an apparatus for recording atmospherics
   /
2666
an experimental proof of the mode theory of vlf ionospheric propagation
   /
2667
a multiple channel dc recording system  describes an am system with
tape noise cancellation enabling up to twelve channels to be recorded
on a conventional single track recorder together with speech and
timing signals
   /
2668
the thermal behaviour of semi conductor rectifiers  measurements
are described which were made on heavy current ge diodes to determine
the thermal inertia  the effect of cooling on the overload characteristic
is discussed
   /
2669
using silicon diodes in radar modulators  a peak power of kw is developed
using si diodes for charging the artificial line and for clipping
reverse voltage swtings  the diodes dissipate instantaneous powers
up to kw
   /
2670
selenium rectifiers with artificial layers of selenides of cadmium
tin bismuth and lead  the action of various selenides as barrier
layers has been investigated by measurement of the rectifier dc and
ac characteristics  cdse and snse layers play an important role in
rectification but the selenides of bi and pb seem to be unsuitable
in general the layer material should have a resistivity cm
   /
2671
current time relationship in the forward direction of electrolytic
rectifiers  qualitative explanation of the effects observed on applying
alternating rectangular and sinusoidal voltages
   /
2672
use of operational amplifiers in precision current regulators  low
drift high gain dc amplifiers in a control loop can reduce steady
state error
   /
2673
study of a digital analogue converter  a technique is described using
bistable multivibrator circuits for generating a current proportional
to the numbers on a binary scale
   /
2674
an analogue computer for the prediction of acoustic propagation in
the atmosphere  ray patterns are presented on a cr tube when air
temperature and wind velocity data are fed into the computer
   /
2675
new horizons in computing  a report of some of the computer engineering
techniques which were described in papers read at the international
conference on information processing held in paris
   /
2676
superconducting computer elements  switching elements working at
and storage elements of the persistent current type with a transition
time of have been developed under laboratory conditions  their successful
commercial possibilities depend mainly on the development of thin
metallic films of consistent quality used in the construction of
these elements
   /
2677
flux controlling type adder  experimental circuits using magnetic
cores to control switching are described
   /
2678
the cryosar a new low temperature computer component  the cryosar
is a high speed component whose operation at about is based on impact
ionization of impurities in ge two types using compensated and uncompensated
ge can be used as bistable and normal diodes respectively
turn on time is about sec  they are very small and present results
suggest excellent reliability
   /
2679
thin magnetic films for digital computer memories  characteristics
of magnetic films and ferrite cores are tabulated
   /
2680
semiconductor devices for microminiaturizatio  integrated semiconductor
devices are illustrated in which active and passive components are
incorporated in a single piece of semiconductor material with no
interconnecting metallic leads their application to logic circuits
is explained
   /
2681
design of random noise transformers  the design is developed from
basic principles and verified by experiment
   /
2682
representation of switching circuits by binary decision programs
   /
2683
the total excursion resistor  the design of resistors that will
remain within a guaranteed tolerance range throughout their life
is discussed
   /
2684
behaviour of square loop magnetic cores in circuits  the switching
time with a loaded secondary winding is derived  the behaviour of
ferrite cores under various conditions of loading and drive is shown
to agree with theory
   /
2685
high speed multiplexing with closed ring counters  the action of
a channel electronic switch which consists of semiconductor diode
gates each controlled by a flip flop circuit is explained  the switch
can sample from to voltage sources at rates as high as
   /
2686
probable life of paper capacitors  a study based on statistical laws
of probability  experimental results are in good agreement with theory
   /
2687
study of the transfer properties of a linear system based on the
concept of rate of growth of spectral energy
   /
2688
elements of electronic circuits part use of short time constant circuits
with diodes and triodes  august
   /
2689
network transformations for wave filter design  calculations are
simplified by charts which enable the configuration of two terminal
networks to be altered while retaining their impedance characteristic
and also to alter the element values without changing the configuration
or impedance characteristics
   /
2690
band pass ladder filter half sections  considering purely reactive
half sections general formulae for branch and image impedances and
reflectionless interconnections are examined
   /
2691
generalization of zobel type ladder filters  a new and simplified
method of design in which the the filter is considered as an indivisible
unit rather than a combination of elementary structures as in the
zobel method
   /
2692
physical theory and technique of electromechanical wave filters
equivalent circuits are derived and the design of some practical
filters is described with details of their performance
   /
2693
constant s equalizers  equations are derived for high medium and
low frequency equalizers based on a bridged t configuration  as equalization
is varied from step to step the point of maximum equalization
changes and the insertion loss s of unequalized frequencies remains
constant
   /
2694
tunnel diodes as high frequency devices
   /
2695
transistor applications in pulse techniques  details are included
of high speed divider circuits and a stabilized dc power unit
   /
2696
transistor circuits for a digital computer  the requirements of amplifiers
used for pulse regeneration are considered and blocking oscillators
and regenerative amplifiers employing transistors suitable for reshaping
and retiming pulses in a digital computer with a digit rate are described
some details of their practical application are given
   /
2697
simplified coincidence circuits using transistor and diodes  a simple
coincidence circuit is described which is as fast as a standard valve
circuit  the measured threshold and resolving time characteristics
are given
   /
2698
transistor circuitry for radiation counting  four instruments are
described a pulse amplifier a pulse height analyser a scaler and
a linear count rate meter
   /
2699
using divider vernier to synchronize pulses  the vernier adds or
deletes pulses at the input of frequency dividers thus enabling the
output to be precisely synchronized eg to the wwv second pulses
   /
2700
present applications of semiconductors  description of semiconductor
applications with particular reference to dc amplification for analogue
computers
   /
2701
wide band amplification at high frequencies  a transmitter incorporating
a wide band amplifier covering is described  distributed amplification
is used with artificial transmission lines in which the shunt capacitances
are provided by the interelectrode capacitances of the values
   /
2702
the design of cathode follower circuits  a detailed summary of design
principles and operating characteristics with a description of several
circuit applications
   /
2703
the fundamentals of a low noise hf preamplifier for to  the circuit
described uses a disk seal triode in grounded grid connection and
is intended for radio astronomy applications  at a wavelength of
cm and with if bandwidth the input noise figure is
   /
2704
contribution to the study of the operation of magnetic amplifiers
the operation of a basic magnetic amplifier circuit is analysed assuming
a square wave input and z rectangular hysteresis loop the area of
which is increased due to eddy currents  an equivalent circuit is
derived that is applicable for the case of a periodic or continuous
control signal
   /
2705
volt second transfer efficiency in fast response magnetic amplifiers
part  as a design parameter  the relation between volt seconds and
ampere turns is confirmed by measurements on a specially designed
magnetic amplifier  part of july
   /
2706
some aspects of feedback in transistor amplifiers  the design of
an amplifier with high input impedance is described and problems
peculiar to the use of feedback in transistor circuits are discussed
   /
2707
parametric energy conversion in distributed systems  analysis of
most types of travelling wave parametric amplifier with little or
no dispersion shows that no exponential amplification at the fundamental
frequency of an applied signal is possible  although the total n
energy increases with distance it is spread among a large number
of frequency cross products  for the beam type system amplification
of the fundamental component may become possible as dispersion increases
but a more detailed analysis is required
   /
2708
the grain boundary amplifier  the construction and characteristics
of an amplifier are described which is based on modulation of the
sheet conductance of a grain boundary in n type ge at k a power amplification
of db was obtained at a frequency of which approached zero
at
   /
2709
a new class of materials for bloembergen type masers  a class of
substances exists which have four levels degenerate in zero field
these levels show a linear zeeman effect but are not necessarily
equally spaced when a magnetic field is applied and there are allowed
transitions which are not limited to those between adjacent energy
levels
   /
2710
superregenerative reactance amplifier  the method of operation of
an l band variable reactance amplifier as a superregenerative amplifier
is described  the results indicate the feasibility of a single stage
low noise microwave receiver
   /
2711
parametric amplifiers and cancellation of ferromagnetic hysteresis
by orthogonal polarization  measurements have been made on tubular
samples of ni zn ferrites showing the effect of a uniform magnetic
field parallel to the axis on the magnetization due to alternating
current in a toroidal winding  for a sufficiently high field intensity
hysteresis becomes negligible and the magnetization curve tends
to become linear  this principle has been applied in the design of
a variable inductance parametric amplifier operating at with a gain
of
   /
2712
parametric amplifiers as superregenerative detectors  the details
of superregenerative operation are described and effects permitting
self quenching are explained  two cavity type parametric amplifiers
using semiconductor diodes are investigated one in the l band near
and the other in the s band near
   /
2713
low noise tunnel diode amplifier  an amplifier consisting of a tuned
circuit shunted by a negative conductance tunnel diode is described
and experimental gains bandwidths and noise figures obtained at are
quoted  greatly improved noise figures and microwave operation should
be possible ultimately  see below
   /
2714
ferroelectric capacitors  a vfo is described which incorporates a
ferroelectric capacitor as a frequency modulating element
   /
2715
the deflection of waves by movement of the media of propagation
optical observations of aberrations of fixed stars are held to be
inconsistent with the hypothesis that light waves are affected by
movements of the ether  this disproves datzeffs theory of which has
already been criticised see of
   /
2716
related experiments with sound waves and electromagnetic waves  analogous
situations in the propagation of sound and em waves are described
and demonstrated experimentally these include cut off effects polarization
rotation and external guiding  superdirective arrays are also
examined
   /
2717
stable orbits of charged particles in an oscillating electromagnetic
field  in the field of a cylindrical waveguide driven in the mode
the particle moves around the axis of the guide  sufficient conditions
for stable orbits are derived
   /
2718
charge penetration into a conductor in equilibrium  statistical mechanics
is used to show that the electric charge on a conductor in equilibrium
is not restricted to its surface but penetrates into the interior
in the form of a space charge density the effective penetration depth
being of the order of a few atomic distances  similarly the electric
potential in a charged conductor is not strictly constant but varies
in space which results in a small but finite potential difference
between the interior and the surface layers
   /
2719
the determination of a criterion for the surface conduction of insulating
solids  an electrode system is described for determining a curve
of the variation of specific resistance of a specimen as a function
of distance between electrodes  a criterion of surface conduction
may be deducted by extrapolation
   /
2720
electron temperature and electron noise in high frequency torch discharges
the noise temperature of an electron torch in air and nitrogen
at atmospheric pressure is measured at and found to be of which about
is due to electron temperature and to shot noise  these results and
the measurements of other plasma characteristics are interpreted
with reference to the findings of other authors  references
   /
2721
nature and role of ionizing potential space waves in glow to arc
transitions  westberg
   /
2722
influence of the diffusion angle on the energy spectrum of an electron
beam after passing through a thin film  measurements have been made
with a magnetic spectrograph on films of al ge and mn
   /
2723
the three dimensional intensity distribution near the focus of waves
diffracted by l slit and rectangular apertures
   /
2724
theory of secondary electron emission of metals
   /
2725
electron emission from the surface of pure molybdenum after bombardment
by electrons  after low energy electron bombardment for a period
of sec pure mo surface at room temperature in the dark was found
to emit electrons at energies up to  the electron current decreased
from to after
   /
2726
the excitation of molecular vibration and rotation by impact of slow
electrons  a new approximate formula is derived for the cross sections
for excitation of molecular vibration and rotation by impact of slow
electrons  account is taken of the fact that in such impacts the
incident electron is moving much faster than the nuclei in the molecule
while its wave function suffers considerable distortion by the molecular
field
   /
2727
electron energy distributions in plasmas part  report of a method
of carrying out a druyvesteyn analysis electronically  the results
show very wide deviations from the maxwellian distribution in striated
discharges and suggest that a high anomalous rate of energy exchange
between the electrons of a low pressure discharge is a much rarer
phenomenon than might be supposed
   /
2728
langevin equation and the ac conductivity of non maxwellian plasmas
   /
2729
microwave investigations of plasma  the basic theory and the experimental
details of three methods are described resonator method waveguide
method and cross modulation method  the ambipolar diffusion and recombination
coefficients and the electron collision frequency are determined
and experimental results are reported
   /
2730
excluded volume problem and the ising model of ferromagnetism
   /
2731
stimulated emission of radiation by relativistic electrons in a ma
gnetic field  an expression is derived for the transfer of energy
between an alternating electric field and electrons moving at right
angles to a magnetic field  it is shown that for relativistic electrons
a net stimulated emission is possible
   /
2732
diffraction by a smooth object  a geometrical theory of diffraction
a theory of wave propagation based on aan extension of geometrical
optics is explained and applied to diffraction problems associated
with smooth convex opaque objects
   /
2733
diffraction of a skew plane electromagnetic wave by an absorbing
right angled wedge
   /
2734
growth of electric space charge and radio waves in moving ion streams
in a medium comprising two identical interpenetrating ion streams
four different space charge phenomena may occur  two of these are
discussed an instability described as a growing ion cloud this is
thought to be the basic mechanism of a two stream amplifier and to
be important in solar rf emission an evanescent wave sometimes wrongly
interpreted as a spatially growing wave  see of and back references
   /
2735
thin absorbent films the problem of optimum thickness in connection
with a classification of these films  theoretical note on determining
the film thickness for which the absorption of an incident plane
em wave is a maximum
   /
2736
aan electronic paramegnetic resonance spectrometer influence of
the amplitude of modulation of the magnetic field on the line shape
obtained by synchronous detection
   /
2737
cross relaxation in spin systems  analysis of the transition region
of nearly equally spaced levels
   /
2738
galvanomagnetic properties of cylindrical fermi surfaces
   /
2739
on highly ionized regions of interstellar matter  a parallel is established
between the properties of heavily ionized regions and the superconducting
properties of metals at very low temperatures  this analogy
leads to a new description of certain regions of the interstellar
medium
   /
2740
principles and present results of radio astronomy
   /
2741
the nature of the cosmic radio sources  a detailed review of observational
data and discussion of theory references
   /
2742
radio emission of the sun and planets  a description of the suns
radio emissions during periods of low and high activity on and  radio
bursts are considered and the thermal and sporadic theories are discussed
radio emissions from jupiter venus and mars are also examined
references
   /
2743
radio emission following the flare of august  two types of emission
appear to have occurred  a burst at and decreasing in intensity
with decreasing frequency and a long lasting continuum on frequencies
below delayed with respect to
   /
2744
measurement of the cosmic ray intensity in the stratosphere at various
heights and latitudes  investigation of the altitude dependence of
particles of the cosmic ray soft component in the latitude range
to  results indicate that at a latitude or the majority of particles
of soft components are electrons generated by mesons  at latitude
an excess of electrons is found possessing energies vekiw cn  expressions
are derived for the primary particle energy spectrum  at latitude
the primary cosmic ray particle flux has been found equal to particles
min cm sterad
   /
2745
on recurrent variations in the intensity of primary cosmic radiation
in a period of maximum solar activity  recordings of variation in
the intensity of cosmic radiations made during the period october
to july show a cyclic variation with a stable period of mean solar
days the maximum amplitude being reached in october
   /
2746
flux and energy spectrum of cosmic ray particles during solar maximum
fluxes measured over minnesota and texas in are significantly lower
than those observed at solar minimum  a mechanism is proposed to
explain the changes
   /
2747
cosmic ray cut off rigidities and the earths magnetic field
   /
2748
some indices of solar activity based on ionospheric and radio noise
measurements  methods are described for producing indices of solar
activity based on the ionization of the e and f layers and monthly
mean figures thus derived are tabulated  the two indices are compared
with each other and with solar noise flux at and the correlation
is high  practical applications of the indices are discussed briefly
   /
2749
prediction of sunspot numbers until the end of the present cycle
a modified equation derived from recent data has been used for the
determination of sunspot numbers for the period
   /
2750
relation between type iv emissions and other forms of solar activity
observations indicate a correlation between optical centres associated
with type radio emissions see eg of and radio storm centres
   /
2751
geomagnetic activity following large solar flares  there is a marked
tendency for magnetic disturbance to follow the largest solar flares
no association was shown in the period near sunspot minimum this
confirms the negative result found by watson of for roughly the same
period
   /
2752
the propagation of world wide sudden commencements of magnetic storms
analysis of differences in the recorded time of the first impulse
at ten widely separated observatories suggests that the position
of the sun determines the hemisphere in which the sudden commencement
first occurs
   /
2753
circuits for space probes  brief description of instrumentation in
the payload stage of the pioneer vehicle and at tracking stations
   /
2754
theory of the effect of drag on the orbital inclination of an earth
satellite  it is assumed that the drag is in the direction of the
air velocity relative to the satellite and that its magnitude diminishes
so rapidly with altitude that it is appreciable only near perigee
in an elliptic orbit  results are deduced for the secular changes
in inclination up to but not including the final ballistic stage
   /
2755
optical observations of artificial earth satellites  observations
are made visually using telescopes and are also recorded photographically
an oscillographic method is described for recording the exact
instant of the opening and closing of the camera shutter  these observations
are valuable in the determination of the exact shape of the
earth
   /
2756
radio observations of the first two artificial earth satellites
review of some of the early measurements made by stations in west
germany
   /
2757
radar observations of the second russian earth satellite sputnik
an analysis of observations made with the steerable radio telescope
at jodrell bank at frequencies of and  results suggest that the observed
fading characteristics were due mainly to rotation of the satellite
and from a study of the scattering area it is concluded that the
satellite was a long object having a reradiation polar diagram with
one major and many minor lobes  there was no evidence that the satellite
produced any ionization
   /
2758
recording of sputnik on  field strength recordings taken at breisach
west germany of day time transits during the period november are
discussed
   /
2759
radio astronomical investigations by means of artificial earth satellites
the ionosphere cuts off extraterrestrial radio emissions over
a wide range of frequencies  thus observations which would not be
possible on the ground could be made from satellites
   /
2760
investigation of sola r corpuscular radiation using artificial earth
satellites
   /
2761
discovery of electrons in the upper atmosphere by means of the third
soviet earth satellite  note of electron energies recorded between
and above sea level  the maximum electron energy registered was v
   /
2762
investigations of the ionosphere by means of an artificial earth
satellite  a description of methods based on the doppler effect in
which correct results depend on the appropriate choice of the two
frequencies used
   /
2763
some deductions of ionospheric information from the observations
of emissions from satellite the theory of the analysis  the effect
of the ionosphere on the doppler shift frequency and on the frequency
of faraday fading is expressed theoretically in terms of the difference
in phase path of the waves for two positions of the satellite
   /
2764
some deductions of ionospheric information from the observations
of emissions from satellite experimental procedure and results  the
application of the approximate analysis to the small number of suitable
observations suggest that the ionization density decreases slowly
with height above the maximum of at night
   /
2765
some results of the determination of the electron concentration of
the outer regions of the ionosphere by observations of the radio
signals from the first earth satellite  the method of calculating
the path of the radio waves in the outer ionosphere is described
the electron concentrations determined for heights between and which
vary between and are tabulated
   /
2766
the indian program for the international geophysical year some results
of the program on ionosphere  a report of some ionospheric effects
particularly those observed in equatorial regions
   /
2767
a preliminary model atmosphere based on rocket and satellite data
a model atmosphere is described for the height range km and values
of density pressure and scale height are tabulated as functions of
altitude  discrepancies between data from various sources are examined
and it is estimated that they are within the limits to be expected
from latitude variations and the uncertainties of experimental observations
   /
2768
chapman behaviour in the lower ionosphere  it is shown that chapmans
relations for the variation of critical frequency and height of a
layer with solar zenith angle can be applied to any point on that
layer and that it is not necessary to assume monochromatic radiation
these results are then applied to electron density height profiles
and it is shown that chapman behaviour can be detected to a height
of being consistent with a scale height of or km
   /
2769
some wind determinations in the upper atmosphere using artificially
generated sodium clouds  results for the height range km are reported
   /
2770
coefficients for the rapid reduction of records to profiles without
computing aids  the tables of coefficients can be used for the ordinary
ray at any station having aa magnetic dip less than  the sensitivity
of the coefficients to dip angle and gyrofrequency is discussed and
comparisons are made with the profiles produced using the budden
matrix method
   /
2771
spiral occurrence of sporadic e  intense sporadic e ionization at
high latitudes in the northern hemisphere is distributed along a
curve similar to a stormer precipitation spiral for negative particles
   /
2772
an additional lunar influence on equatorial e at huancayo  the time
of first appearance of equatorial e during the period may april is
shown to vary with lunar age  this supports matsushitas hypothesis
on the relation between s currents and equatorial
   /
2773
some further analyses of e layer measurements in south africa during
the solar eclipse of december  a re examination of data see of szendrei
and mcelhinny for preliminary results suggests that the measurements
could be accounted for by assuming that of the solar radiation comes
from outside the visible disk  at the same time it is necessary to
postulate an effective recombination coefficient of cm sec
   /
2774
the electron density distribution in the outer ionosphere derived
from whistler data  a method of successive approximations is developed
to determine the electron density distribution with height in the
outer ionosphere when the variation of whistler dispersion with geomagnetic
latitude is known  the method is applied to specific whistler
data and the results infer that the electron density distribution
decreases exponentially with height in the range km  an equation
is derived for the distribution in this height range during january
may
   /
2775
some possible effects caused by strong gyro waves in the ionosphere
a theory is developed for the effect of an extremely powerful pulse
of extra ordinary gyro waves on the nocturnal e region near km and
the day time d region near km  the changes in collisional frequency
and electron density at these levels are derived with their consequent
effects on the propagation characteristics of a transverse ordinary
wave at kcs  it is shown that with radio pulses of sufficient power
observable changes may be produced in air glow meteor trails fast
particle tracks and local magnetic elements  it would also be possible
to use such a pulse to determine the coefficient of attachment at
the km and km levels
   /
2776
auroral x rays cosmic rays and related phenomena during the storm
of february  balloon observations of x ray bursts coincided with
magnetic bays radio noise absorption and auroral luminosity
   /
2777
photoelectric measurements of hydrogen emissions in aurorae and airglow
   /
2778
theory of the origin of the very low frequency radio emissions from
the earths exosphere  the gyro rotation of solar protons about the
earths magnetic field corrected for doppler shift is used to derive
a general equation of the theory see of
   /
2779
interpretation of smooth type atmospheric waveforms  accurate waveguide
or pulse reflection analysis of the regular type of smooth waveform
reveals a subdivision termed pseudo regular  this type can be satisfactorily
explained using waveguide or pulse reflection theory of propagation
when complicated source conditions are considered and the discharge
in the lightning channel is not assumed to be effectively instantaneous
   /
2780
very low frequency spectra of atmospherics propagated through the
ionosphere  a report of experimental results which support the mode
theory suggested by budden
   /
2781
transistor rectifier gives dc of either polarity  a diagonally symmetric
power transistor circuit which permits smooth load current variation
over a range of several amperes
   /
2782
transistorized three phase power supplies  a description of the circuits
required to convert a dc supply to a phase supply
   /
2783
transistor invertors and rectifier filter units  details are given
of a symmetrical push pull circuit with improved output waveform
and a bridge connection for very high output power  both operate
from a supply
   /
2784
measuring load characteristics of silicon cells  a simple test circuit
is described which can be inserted in any type of rectifier circuit
   /
2785
pn junctions in germanium  the improvement of the physical characteristics
of junctions is discussed with particular reference to power
rectifiers
   /
2786
switching vhf power with silicon diodes  a coaxial type of switch
designed for aircraft aerial systems
   /
2787
ball relays  a relay is described in which a ball or a number of
balls of a permeable material attracted to an energized core simultaneously
completes both the magnetic and the output circuits  various
forms of the basic design and their applications are given  the advantages
are long contract life low control power and simple construction
   /
2788
testing high speed digital computer circuits  a word generator providing
bit serial binary words at a rate of is described  any one of words
can be selected manually  high tetrodes are used to obtain high speed
operation
   /
2789
automatic input equipment for commercial data processing systems
magnetic equipment for reading documents with characters and symbols
printed in magnetic ink is described  with a high speed transportation
arrangement characters can be read and documents handled per second
   /
2790
a fast method of reading magnetic core memories  description of a
word bit storage system using a method of core threading suggested
by renwick of  the system includes a circuit which prevents parasitic
pulses from blocking the output amplifiers reducing the cycling time
to
   /
2791
the parametron a digital computing element which utilizes parametric
oscillation  japanese research and applications of parametric oscillation
are described  a parametron element is essentially a resonant
circuit with a nonlinear reactance oscillating at haalf the driving
frequency  a binary digit is represented by either of two stationary
phases radians apart
   /
2792
a negative resistance for dc computers
   /
2793
microwave parametric subharmonic oscillators for digital computing
a variable capacitance oscillator with output frequency is described
and its use for amplifying scaling and performing logic functions
is discussed  the advantages of carrier over base band systems for
high speed computing are mentioned  see above
   /
2794
dynamic testing of computer building blocks  a variable frequency
pulse source with repetition frequency up to is described
   /
2795
transistorizing electronic equipment  a general discussion of semiconductor
devices giving tabulated data on ge and si diodes and transistors
specifications of associatted thermistors capacitors and batteries
and a note on the construction of solid circuits
   /
2796
some broad band transformers describes the construction theory and
performance of transmission line transformers which take the form
of twisted pairs having distributed interwinding capacitance  bandwidth
ratios as high as in the range can be obtained with transformation
ratios of unity or
   /
2797
some notes on the optimum design of stepped transmission line transformers
   /
2798
double tuned transformers steady state and transient response  a
general analysis applicable to both wide and narrow band cases  all
degrees of coupling are examined and expressions are derived for
insertion loss phase shift envelope delay rise time and overshoot
   /
2799
current noise and nonlinearity in pyrolytic carbon films  a high
correlation exists between noise and nonlinearity when the variations
in film dimensions are taken into account  a balanced bridge method
for measuring nonlinearity is described
   /
2800
microwave semiconductor switching techniques
   /
2801
switching circuits for missile count downs  a transistor circuit
is described which produces a switching pulse if its input differs
by more than a predetermined amount from a given reference level
the use of nonlinear negative feedback ensures stable operation
over a wide temperature range
   /
2802
voltage variable capacitor selection guide  tabulated information
is presented to facilitate the choice of the best component for the
circuit requirements
   /
2803
elements of electronic circuits  amplitude selection and amplitude
comparison  october
   /
2804
signal flow graphs  an article in three parts covering basic theory
topological relations for network synthesis and applications to feedback
theory
   /
2805
signal flow graphs  a discussion of the application of masons technique
of circuit analysis of and of
   /
2806
dissipation loss in multiple coupled resonator filters  a simple
approximate formula enables centre frequency loss to be computed
and elsewhere loss may be computed from the prototype low pass filter
after suitable circuit modification  unsymmetrical and symmetrical
designs are considered
   /
2807
miniature resonators for uhf  an investigation of the extent of miniaturization
possible in coaxial resonators
   /
2808
a negative resistance for dc computers  a nomogram is presented for
the design of a circuit using transistors and resistors to give any
required value of negative resistance
   /
2809
some applications of non euclidean geometry in quadripole theory
a survey of literature and an attempt to correlate the work of various
authors  the treatment of impedance and noise transformations by
means of the poincare and cayley klein models of non euclidean hyperbolic
space is discussed  references
   /
2810
novel expression for the relationship between the real and imaginary
parts of the transfer function of a linear filter  lipkin
   /
2811
theory a nd design data for the synthesis of tchebycheff parameter
filters
   /
2812
microwave parametric subharmonic oscillators for digital computing
   /
2813
experiment indicating generation of submillimetre waves by an avalanching
semiconductor
   /
2814
curves obtained by van der pols method for an oscillator with cubic
nonlinearity
   /
2815
frequency control of magnetic multivibrators  a basic circuit is
developed allowing output frequency to be controlled continuously
or in steps over a wide frequency range  variations of the circuit
provide similar controls of output amplitude
   /
2816
designing transistor circuits sequential circuits parts  bistable
flip flop a stable and monostable multivibrator blocking oscillator
and negative resistance circuits and transistor reactor combinations
are discussed
   /
2817
stepping up frequency with counter circuits  precise frequency multiplication
is achieved with digital feedback counter divider circuits
and a phase comparator  the circuit described multiplies frequencies
between and by a factor of with an error of
   /
2818
reducing errors caused by power supply variations  differential amplifiers
in cascade cancel the errors
   /
2819
concertina phase splitter  the performance of the circuit is analysed
with particular regard to the frequency range of operation
   /
2820
graphical determination of the operating characteristic of a magnetic
amplifier  a method of constructing a performance characteristic
for a magnetic amplifier is described based on the equivalent circuit
derived earlier of october bernard and pio taking account of the
nonlinearity of the associated rectifier and expressing output current
as a function of current in the control circuit
   /
2821
q multiplication with transistors  two transistor circuits are described
with negative impedance stable to within over a temperature range
   /
2822
feedback design for transistor amplifier stages  equations are given
for realizing a specific input impedance or maximum feedback for
a given gain
   /
2823
avalanche controlled semiconductor amplifier  the theory of a particular
avalanche controlled semiconductor amplifier is given its hf operation
should be good
   /
2824
three level spin refrigeration and maser action at
   /
2825
method for calculating simultaneous resonance conditions in a three
level ruby maser
   /
2826
multilevel pulsed field maser for generation of high frequencies
the maser has been operated at as an oscillator at both and with
a pumping frequency of  principles of operation and characteristics
are discussed
   /
2827
low field x band ruby maser  the signal frequency used was and the
pump frequency  the low pump frequency and low magnetic field requirements
are attractive although the achievable gain bandwidth product
is lower than with other masers
   /
2828
a surface wave parametric amplifier  the proposed amplifier takes
the form of a slab of ferroelectric material between two conducting
planes  the slab is pumped with high power  useful gain would be
achieved at x band frequencies even with present ferroelectric materials
with new materials the amplifier could be used at mm
   /
2829
relaxation phenomena in diode parametric amplifiers  oscillations
have been observed in parametric amplifiers under certain conditions
with cw pump sources  the effect varies with pump power being a relaxation
oscillation at lower pump power and a stable oscillation when
this is increased
   /
2830
lumistors amplifiers of the future
   /
2831
criterion of uniqueness for the solutions of maxwells equations
a linear medium characterized by the absence of dielectric or magnetic
hysteresis is considered
   /
2832
two coordinate colour  a short discussion of the subjective and objective
characteristics of a colour and their relation to colour vision
the two colour experiments of land are summarized and their bearing
on goethes two colour theory of and granits recent experiments is
indicated
   /
2833
grapho analytical plotting of trajectories of charged particles in
variable electric and constant magnetic fields  two techniques are
described based on addition of velocities and radius of curvature
examples of plotting using these two methods are shown  errors and
means of correcting them are indicated
   /
2834
the phenomenon of depolarization in small conducting bodies in an
extensive electromagnetic high frequency field  continuation of earlier
investigations  current density and internal field are calculated
as a function of the external field  the results are discussed with
reference to measurements on ge in the temperature range at
   /
2835
role of negative effective mass in negative resistance  a theoretical
investigation of the relations between negative effective mass carrier
distribution and negative resistance
   /
2836
impurity scattering in super conductors  perturbation theory is used
to determine the reduction in super conducting transition temperature
due to scattering by impurities dissolved in the superconductor
   /
2837
the radiation from a charged particle passing through a plate  expressions
are derived for the fourier components of the radiation field
in the space in front of and behind a dielectric plate in vacuum
   /
2838
motion of a charged particle in an anisotropic medium  expressions
are derived for the em field components and the total energy losses
are determined for a charged particle moving in an anisotropic gyroelectric
and gyromagnetic medium
   /
2839
magnetic perturbation of cathode rays  the splitting of an electron
beam when it penetrates a magnet was observed with electron diffraction
apparatus  an explanation is given in terms of polarization of free
electrons
   /
2840
ion drag pressure generation  a theory of pressure build up under
unipolar ion conduction is presented and verified experimentally
constriction of the current flow leads to sizable pressures in insulating
liquids
   /
2841
on acoustic electrical phenomena in a degenerate electron ion plasma
a calculation of the absorption coefficient for ultrasonic waves
travelling in a plasma
   /
2842
low frequency oscillations of plasma in a magnetic field  mathematical
analysis of small oscillations of a plasma consisting of electrons
and singly charged ions  some limiting cases are discussed for which
a solution of the dispersion equation can be found
   /
2843
on the behaviour of a conducting gaseous sphere in a quasistationary
electromagnetic field  investigation by the perturbation method of
the stability of a homogeneous plasma sphere with an external field
   /
2844
statistical derivation of the dispersion formula of a lorentz plasma
of finite temperature
   /
2845
an investigation on plasmas in external magnetic fields steady state
varying fields  in english
   /
2846
dependence of electron mobility on magnetic field in a fully ionized
gas  analysis with tables and illustrative graphs of the variations
of drift and hall mobilities with magnetic field
   /
2847
a system of magnetic moments in a weak variable magnetic field  a
mathematical analysis of a system of magnetic moments which possesses
electric exchange and weak magnetic dipole dipole interactions and
which is located in an external magnetic field  the equation of motion
of the magnetization vector is derived and the limits of its applicability
are discussed
   /
2848
on magnetic permeability for the case of magnetization under the
action of a circular alternating field in the presence of a dc longitudinal
field  a method is described for measuring the permeability
of a torsion free iron wire  results are given for various values
of the circular alternating field the longitudinal field and the
wire tension
   /
2849
ferromagnetic resonance in a circularly polarized electromagnetic
field of arbitrary amplitude  the exact solution of the magnetization
equations of motion is examined  the dependence of the magnetization
components on the amplitudes of the magnetizing field and rf field
is determined
   /
2850
cherenkov radiation from dipoles  mathematical analysis of the cherenkov
radiation from electric and magnetic dipoles moving in a continuous
medium in a channel or a slit
   /
2851
on the cherenkov radiation of an electron moving in a medium with
spatial dispersion  an examination of the cherenkov radiation in
an isotropic medium including a consideration of spatial dispersion
the angular distribution of the radiation intensity and the escape
of the radiation through the surface of the medium are discussed
   /
2852
radio emission from an atomic explosion  in an atomic explosion which
is accompanied by asymmetric emission of quanta radio waves are emitted
due to the presence of a current in the ionized air  the duration
of the oscillation in each halfwave is of the order of  for a given
asymmetry in emission of the rays the amplitude of the oscillations
depends weakly on the total number of quanta
   /
2853
emission of radio waves from detonations  transient em waves giving
a field strength of about close to an explosion of high explosive
were recorded using a receiver tuned to  they are attributed to ionic
rather than thermal effects  see of
   /
2854
discussion of the influence of frequency in the problem of the investigation
of the optimum absorption thickness for a thin metallic film
the absorption of em waves by films so thick as to be equivalent
to the solid material and by very thin films is considered
   /
2855
spectral diffusion phonons and paramagnetic spin lattice relaxation
discussion of paramagnetic relaxation phenomena at low temperatures
by analogy with holsteins theory of trapping of resonance radiation
in gases
   /
2856
on the overhauser stationary effect in paramagnetic salts and semiconductors
discussion of the problem of obtaining stationary nuclear
polarization in nonmetals by means of a complete or partial saturation
of one or more components of the paramagnetic resonance hyperfine
structure
   /
2857
three level spin refrigeration and maser action at  positive and
negative signal spin temperatures both small compared to the ambient
temperature can be realized through three level excitation
   /
2858
optical maser design  excitation by electron impact is suggested
for a maser working in the visible region  see of june
   /
2859
possibility of production of negative temperature in gas discharges
the production of negative temperature by the excitation of atomic
levels is suggested and the difficulties of obtaining sufficient
excited atoms for maser action are considered
   /
2860
handbuch der physik encyclopedia of physics  vol  electric fields
and waves  the volume comprises the following five parts  static
fields and stationary currents  g  wendt in german  quasi stationary
a nd nonstationary currents in electric circuits  r  king in english
electromagnetic waveguides and resonators  in english  propagation
of electromagnetic waves  the dispersion and absorption of electromagnetic
waves
   /
2861
angular diameter measurements of the radio sources cygnus and cassiopeia
on a wavelength of cm  results given in each case for two directions
at right angles show that cassiopeia is circularly symmetrical and
approximately the same size at metre wavelengths while cygnus is
markedly asymmetrical with a major axis which may be slightly larger
at the shorter wavelength  the position angle of this major axis
is is  measurement equipment is described
   /
2862
aerial array operating at  an array of mirrors in diameter mounted
at equal intervals on a beam long has been erected at nancay from
for the study of rf solar radiation by interferometry  centres of
rf emission are found closely associated with optical centres
   /
2863
the radio emission from the direction of the supergalaxy  an analysis
of observations made at suggests that the band of radio emission
running perpendicular to the galactic plane at about is not associated
with the local supergalaxy
   /
2864
theory of the cosmic ray equator  the westward shift of the cosmic
ray equator from the geomagnetic equator is explained by assuming
that there exist ionized atmospheric layers which rotate more slowly
than the earth  the resultant magnetic field beyond the layers is
then a dipole field whose magnetic north pole is west of the geomagnetic
north pole
   /
2865
effect of magnetic anomaly on particle radiation trapped in geomagnetic
field  july
   /
2866
investigation of variations in cosmic radiation  the phenomena which
can be investigated by an artificial earth satellite and the measuring
instruments which can be installed in it are described
   /
2867
investigation of ultraviolet solar radiation
   /
2868
on the structure and mechanism of sunspots
   /
2869
on a possible mechanism of solar nonstable processes leading to neutron
eruptions  the hypothesis is proposed that the formation within the
sun of a nucleus with increased lithium concentration may be the
initial cause of nonstable processes of all kinds and in particular
the formation of sunspots
   /
2870
the geometry of the earths magnetic field at ionospheric heights
   /
2871
induced electromagnetic fields in the earth  a general theoretical
study of the effect of geomagnetic variations in the earth
   /
2872
geomagnetic effects of nuclear explosions  report of an analysis
of changes in the earths magnetic field which occurred when two bombs
were exploded at night at a high altitude over johnston island and
august  results indicate that the upper atmosphere at a distance
of km was ionized to near daytime intensity  field changes were detected
up to km away  for a shorter account see electronics vol
   /
2873
geomagnetic disturbances due to nuclear explosion  possible reasons
for the observed effects at honolulu on and august are discussed
   /
2874
magnetic effects resulting from two high altitude nuclear explosions
an examination of vector diagrams of geomagnetic variations in a
horizontal plane due to explosions on and august indicates that the
effects may be classified into four phases initial second main and
final
   /
2875
some geomagnetic phenomena associated with nuclear explosions  magnetograms
recorded at three station in the immediate area of the explosion
on show no disturbance of the h component of the earths field at
the time of major disturbances in z and d components  vector diagrams
of the disturbance in the vertical plane at the three stations are
compared with those for the explosion on and are found to be markedly
similar despite the different geographical positions and altitudes
of the two events in the latter event changes in the h component
were comparable with those in z and d
   /
2876
geomagnetic pulsations and the earths outer atmosphere  hydromagnetic
oscillations of the ionized outer atmosphere are considered as a
possible cause of geomagnetic pulsations  observational results are
applied to this model and the distribution of ionic density is determined
   /
2877
important contribution to international scientific collaboration
a brief report on the fifth assembly of the special igy committee
which took place in moscow august  delegates from countries were
present and some preliminary results were discussed
   /
2878
some dynamic problems of flight to the moon  trajectories for reaching
the moon or for flying round the moon and returning to the earth
are considered  the initial rocket velocities and the distances from
the earth and moon of four different orbits are tabulated  a periodic
orbit passing near the moon and earth seems to be impractical because
an error in the initial velocity of mm sec would be enough to allow
the rocket to escape into space after only four revolutions  for
a shorter account see
   /
2879
the launching of a cosmic rocket towards the moon  a short account
of the day to day progress of the cosmic rocket from to january
in the first hours it travelled to a distance of passing the moon
and entering an orbit round the sun  see below
   /
2880
the launching of cosmic rockets and astronomical problems  march
   /
2881
soviet cosmic rocket  a description of the kg rocket which was fired
on the and which passed within a distance of of the moon  the orbit
round the sun lies between the earth and mars and has a period of
months  the minimum and maximum distances from the sun will be and
km  signals were emitted from the rocket on and  the eccentricity
of the orbit is as compared with for the earth  a photograph of the
sodium cloud released at a distance of km is shown
   /
2882
satellites and space probes launched in us and ussr  a tabulated
summary of launching dates instrumentation and results
   /
2883
some variational problems connected with the launching of an artificial
earth satellite  a mathematical analysis of the best angle of elevation
for a rocket which is required to put a satellite into an orbit with
minimum fuel consumption and allowing for a variable gravitational
field and the rotation of the earth
   /
2884
determination of the lifetime of an artificial earth satellite and
study of the secular perturbations of its orbit  a general mathematical
method is described which is valid for any satellite and which takes
account of the distribution of atmospheric density with altitude
this method is based on single parameter series of integral curves
of a first order equation  from graphs and tables the satellite lifetime
and the variation of the orbital parameters with time are rapidly
calculated  the effect of atmospheric rotation on the secular variations
of the satellites orbit are found to be small
   /
2885
the motion of an artificial satellite in the noncentral field of
terrestrial gravitation in the presence of atmospheric resistance
the orbit of a fictitious satellite of weight kg and diameter has
been calculated in four hours using an electronic computer  the perigee
revolves around the earth times in days  the ascending node regresses
in the direction opposite to the earths rotation at a rate of about
per day
   /
2886
effect of geophysical factors on the motion of a satellite  the orbital
calculations based on the use of differential equations in terms
of elliptical osculating elements depend on the accurate estimation
of geophysical factors such as air resistance and gravitational anomalies
the determination of these factors from satellite observations
is considered
   /
2887
the use of artificial earth satellites for the verification of the
general theory of relativity  three main points could be examined
the rotation of the perigee of mercury which according to theory
should revolve in a century the deflection by of light rays in passing
near the sun the gravitational shift of spectral lines
   /
2888
an experimental and indirect method for determining the high atmospheres
density  an approximate method is described for calculating the density
of the atmosphere above km using as data observed life times of artificial
satellites no longer in orbit  calculated densities are compared
with those measured by means of rocket probes
   /
2889
new approach in the theory of satellite orbits  a proposed co ordinate
system is useful for investigating the motion of an earth satellite
   /
2890
short time measurement of time dilation in an earth satellite  a
method for measuring the gravitational red shift based on the variation
of the frequency difference between two oscillators as a function
of altitude
   /
2891
air density in the upper atmosphere from satellite orbit observations
the results given agree with those of king hele of
   /
2892
investigation of cosmic rays by means of artificial earth satellites
these investigations led to the discovery of a belt of charged particles
round the earth which at a height of passed at the rate of particles
per sec through an area cm  this radiation would be very dangerous
to unprotected living beings
   /
2893
ionizing radiation at altitudes of to kilometres pioneer  the total
ionizing component of cosmic radiation was measured on october by
means of an ionization chamber mounted on the pioneer lunar probe
vehicle  data were taken over an altitude range of to and a latitude
range of to  the calibration procedure and the analysis of the telemetered
data are described
   /
2894
satellite observations of solar cosmic rays  on three occasions during
august large increases in the intensity of charged particles outside
the van allen radiation zones were detected by at high magnetic latitudes
and low satellite altitudes  it is suggested that these increases
are due to solar protons associated with large solar flares
   /
2895
investigation of the earths magnetic field using an artificial earth
satellite  an investigation by means of magnetometers located on
the satellite of the space distribution of the earths magnetic field
at great heights and of inhomogeneities in the ionosphere  the effect
of the magnetic field on the polarization of radio waves reflected
from the ionosphere the latitude effect of cosmic rays and auroral
phenomena are considered
   /
2896
problems of measurement of the pressure and density of the high layers
of the atmosphere by means of artificial earth satellites  temperature
pressure density and composition between and are tabulated  the concentrations
of oxygen and nitrogen between and km are also shown
   /
2897
the density of the earths outer atmosphere according to satellite
observations  orbital data of satellites and are used to determine
atmospheric density above km  results agree closely with those obtained
from observations of satellites and  retardation effects are also
discussed  measurement of the concentration of positive ions along
the orbit of an artificial earth satellite  the surface potential
of a satellite and the distribution of charged particles around it
are discussed  instruments for measuring the ion concentration and
the transmission of results to earth by radio telemetry are described
graphs of the air temperature a t different heights are also shown
references
   /
2898
preliminary results of measurements on doppler shift of satellite
emissions  measurements of transmissions from and on and have been
analysed to investigate the influence of the propagation path on
observed data  results indicate that the wave travels about slower
than the wave
   /
2899
refraction of very high frequency radio signals at ionospheric heights
calculations relevant to the radio tracking of space vehicles show
that refractive errors due to the troposphere rapidly decrease with
increasing elevation angle while those due to the ionosphere initially
increase the with elevation angle and then decrease gradually  the
elevation angle error is plotted for realistic models of the ionosphere
and troposphere
   /
2900
work carried out under the auspices of the indian national committee
for the igy  the following papers and data are included a preliminary
report on the nature and origin of atmospherics  atmospheric electricity
observations in india during the igy  radiosonde techniques for measuring
potential gradient and conductivity  geomagnetic work at alibag
annamalainagar and trivandrum during the igy  atomic nitrogen in
the thermosphere  ionospheric disturbances at low latitudes  studies
of cosmic radio noise on at ahmedabad  meteors and ionization  rates
of fading of reflected pulses of vertically incident electromagnetic
waves at ahmedabad on and  observations on galactic radiation at
diurnal variation of ionospheric absorption on at waltair during
the igy  effect of enhanced solar activity on the f region drifts
at waltair  a new continuous wave radio method for the study of ionospheric
drifts  program of igy solar observations in india  solar control
of some unusually remarkable geophysical events  radio emission from
the sun at the  radio patrol of solar flares  optical tracking of
artificial satellites  table solar flares during july to september
table sudden enhancement of atmospherics sea during july to august
table sudden cosmic absorption sca during july  table solar flare
effects recorded during july to june
   /
2901
investigation by rockets of the composition of the atmosphere at
great heights  a description of containers designed to collect samples
of the atmosphere is given and results obtained between and are tabulated
   /
2902
measurements of the pressure in the upper atmosphere  a description
is given of a container with recording instruments which after release
from a rocket record the pressure of the upper atmosphere  a comparison
is made between pressure measurements obtained in usa and ussr at
pressure and temperature variations at different heights are shown
graphically
   /
2903
investigation of ionic composition of the ionized layers of the atmosphere
rockets and artificial satellites equipped with mass spectrometers
of the type described by bennett automatically sending results to
the earth are considered  the ionization of the atmosphere by a fast
moving satellite vehicle and the effect of the vacuum created behind
it are also examined
   /
2904
results obtained with rocket borne ion spectrometers  a description
of the instrumentation used and an analysis of the results obtained
from the three flights in which both positive and negative ion spectrometers
were flown
   /
2905
some studies of the upper atmosphere in the auroral zone  observations
show close correlation between blackouts complete blanketing of f
by e slant and geomagnetic ba y disturbances  the height of the absorbing
region responsible for the daytime polar blackout appeared to
be lower than when the event occurred at night  to explain these
results the effect on the ionosphere of x rays generated by solar
particles is discussed
   /
2906
model of the ionosphere  electron density data obtained by a russian
rocket can be correctly interpreted by the f layer model proposed
in the
   /
2907
the worldwide distribution of the f layer electron density seasonal
and nonseasonal variations and correlations with solar activity
seasonal and nonseasonal variations of the maximum electron density
in the f layer at noon are largely asymmetrical in the two hemispheres
at midnight they are symmetrical  a general circulation of the upper
atmosphere is suggested as an explanation for these and other anomalies
discussed
   /
2908
the diurnal development of the anomalous equatorial belt in the f
region of the ionosphere  a study is made of the latitudinal distribution
of for each hour of the day for the equinoctial months at sunspot
minimum and also of the diurnal variation of at a number of low latitude
stations  the observed behaviour of in both cases is suggested to
be due not only to vertical drift of ionization but also to horizontal
movement between the poles and the equator during the day
   /
2909
time and height variations in the daytime processes in the ionosphere
part  an extension of earlier work of  variations of the decay of
electron density with height are discussed for the height range km
an expression is developed for the loss coefficients over this range
for northern middle latitudes at noon
   /
2910
geomagnetic and ionospheric phenomena associated with nuclear explosions
magnetograms and ionograms recorded at stations in the central
pacific ocean have been analysed for the periods covering the explosions
on and august  some geomagnetic variation could be explained by a
dynamo effect associated with wind velocities of miles sec and a
ten fold increase in electrical conductivity
   /
2911
some effects of nuclear explosions on ionospheric vertical incidence
soundings  an analysis of observations made at tahiti maui and rarotonga
at the time of an explosion on abnormal absorption which lasted
three hours was recorded at maui and tahiti for auroral effect see
of may the  on the august the date of another explosion the onset
of abnormal absorption at maui and rarotonga appeared to be delayed
by five hours
   /
2912
sudden ionospheric disturbances caused by an atomic explosion  a
note on recordings of atmospherics and solar rf bursts made at toyokawa
japan
   /
2913
disturbance in the ionospheric region following the johnston island
nuclear explosion  from a study of time delay at various observatories
in the vicinity it is assumed that the ionospheric disturbance due
to the explosion on the august is a by product of a gaseous shock
wave propagated at a velocity considerably greater than that of sound
anomalies in this assumption are discussed
   /
2914
measurement of electrostatic fields in the upper layers of the earths
atmosphere  the charge acquired by a body located in a plasma is
examined  an instrument measuring the field potential in the ionosphere
is described  electrostatic field variations due to moving rockets
or satellites are considered
   /
2915
ionosphere electron densities and differential absorption  a review
of daytime ionosphere measurements made over new mexico using a rocket
to ground cw radio propagation method and a preliminary report of
similar measurements made in the arctic ionosphere during polar blackouts
   /
2916
on the measurement of virtual height
   /
2917
interpretation of the variation of ionospheric absorption as a function
of frequency  errors in nondeviative absorption calculations are
attributed to the presence in the e layer of a thin densely ionized
e layer  the expression used earlier has been revised  results obtained
using the new expression indicate that it allows a more detailed
study of the absorption process
   /
2918
ionospheric conditions in the circumpolar region  a preliminary analysis
of ionospheric and magnetic field measurements made from a drifting
observatory in the arctic ocean during the period may april  values
of were obtained for during the arctic night
   /
2919
investigation of the solid component of interplanetary matter by
means of rockets and artificial earth satellites  the kinetic energy
of micrometeorites is measured by an acoustic method or by a new
type of sensitive photomultiplier  results of collisions of these
particles with polished plates located on rockets are shown  tables
giving values of brightness mass radius and estimated fall out on
the earth in hours are included  particles ejected from the sun and
charged cosmic dust are also considered
   /
2920
a preliminary meteorological study of the origin of whistlers  a
possible unique source of whistling atmospherics is found to be the
presence of large cyclonic disturbances at the geomagnetic conjugate
point for the whistler receiving station  the possible role of these
cyclonic disturbances in producing narrow magneto ionic duct propagating
conditions is also discussed
   /
2921
control techniques  annual review covering investigations of control
problems methods of control and regulating equipment  references
   /
2922
silicon solar batteries as a source of electrical supply in artificial
earth satellites  experiments using si pn junctions to convert solar
radiation into electrical energy are described  photo elements having
a surface area of cm and a thickness of mm were used  at sea level
with the suns rays incident normally an efficiency of was recorded
corresponding to for an area of m  with a solar constant of a si
plate exposed to the sun showed a temperature of
   /
2923
breakdown of silicon power rectifiers  a description of a type of
breakdown which can occur when si junction rectifiers are used in
series to rectify a high frequency hv supply  the cause was traced
to minority carrier storage effects and methods of overcoming it
are described
   /
2924
elimination of the effect of thermal delay of the cathode on a valve
with grid compensation  the circuit described earlier of may is adapted
for the compensation of transient fluctuations by means of an rc
network which delays the application of the compensating voltage
to the grid
   /
2925
magnesium bismuth oxide dry cells  the cell construction and its
performance characteristics are described  after an initial voltage
drop cells have a flat voltage discharge curve slightly above
   /
2926
zinc mercuric dioxysulphate dry cell  a cell is described which has
the desirable characteristics of the mercuric oxide alkaline cell
the conventional construction of the dry cell and a relatively flat
discharge characteristic at for loads within the rated current density
   /
2927
controlling the digital computer  a non mathematical discussion of
the programming and application of computers for scientific purposes
   /
2928
an experimental arithmetic unit  detailed description of a unit which
performs a repetitive multiplication program and checks the results
for errors
   /
2929
the design of the ferranti pegasus computer  the detailed engineering
aspects of the design problem are discussed  part
   /
2930
a word magnetic core memory  the storage matrix consists of ferrite
cores and has a read write cycle of  its construction is described
together with the driver and sense amplifier circuits
   /
2931
a positive integer arithmetic for data processing
   /
2932
irredundant disjunctive and conjunctive forms of a boolean function
a thorough algebraic method is described for determining the complete
set of irredundant normal and conjunctive forms  the procedure is
mechanical and the method can be applied for programming computers
   /
2933
electronic computers  the application of analogue computers to the
solution of control system problems
   /
2934
approximating nonlinear functions by shunt loading tapped potentiometers
in analogue computing machines
   /
2935
the multipurpose bias device part the commutator transistor  a study
of the application of the rutz commutator transistor to three input
one output logical problems for handling by automatic computer systems
the rutz commutator is a single emitter amplitude sensitive device
with three separate input wires applied to the emitter  its design
will be detailed in a subsequent paper
   /
2936
two collector transistor for binary full addition
   /
2937
a mathematical model for determining the probabilities of undetected
errors in magnetic tape systems
   /
2938
the magnetic tape store for pegasus
   /
2939
the recording of digital information on magnetic drums  methods of
representing binary digital information on magnetic drums are discussed
with regard to their reliability cost and technical merits
   /
2940
international components symposium  summary of papers read at the
royal radar establishment malvern in september  reliability efficient
use of space liquid cooling techniques and optimum component shapes
for automatic assembly are discussed
   /
2941
calculation of inductance of toroids with rectangular cross section
and few turns
   /
2942
solid circuits  discussion of the international symposium on electronic
components held at malvern england  a solid circuit forming the equivalent
of several transistors connected by resistors and capacitors
is obtained by depositing films of conductive resistive and dielectric
materials on a small block of semiconductor material  the solution
of problems regarding the operation of components at high temperatures
is mentioned
   /
2943
printed circuits in receiver construction  outline of development
of the printed circuit and description of modern production techniques
   /
2944
pro and con on seven different methods of printed wiring  the basic
techniques for each method are described and compared  a table of
relevant us patents is included
   /
2945
a circuit theorem on rectification  nonlinear capacitors and inductors
cannot effect rectification unless nonlinear resistance is present
in the circuit
   /
2946
new method of evaluating ferro inductors  formulae for calculating
the insertion loss and the resistance increase due to the iron core
are derived  the practical factors governing optimum coil design
are investigated
   /
2947
cold cathode voltage transfer circuits  practical techniques used
in the application of cold cathode triodes are given in detail  a
number of circuit diagrams is included
   /
2948
charge and discharge of a nonlinear condenser through a linear nondissipative
inductance  has shown that for a capacitor with a semiconductor
as dielectric the capacitance is proportional to where is the voltage
across the capacitor and is the voltage across the capacitor and
is a constant  a circuit is analysed in which such a capacitor is
connected in series with a lossless inductance and a direct voltage
source and a comparison is made with an exponential capacitor exp
applications to the generation of rectangular and triangular waveforms
are indicated  see also of  evaluating base materials for printed
capacitors  definition of terms specifying the losses of base materials
used for printed circuits which affect the size and q factor of printed
capacitors
   /
2949
a vacuum plant for the frequency calibration of quartz vibrators
see also of
   /
2950
a network theorem  the impedance level of half a symmetrical network
can be changed without altering the frequency response the use of
this theorem for the solution of network problems is discussed and
illustrated by an example
   /
2951
noise and noise free two port networks treated by the isometric circle
method  see
   /
2952
on the design of four terminal interstages for pulse applications
the limits set by the input and output capacitance on the time response
and the conditions for no overshoot are determined  methods for achieving
the necessary pole distributions are described and circuit networks
suggested
   /
2953
the mathematical treatment of transistor feedback circuits  formulae
are tabulated giving in convenient form the parameters of transistor
networks for four types of feedback circuit
   /
2954
design and development of strip line filters
   /
2955
concentric shear mode electromechanical filter  an experimental filter
of simplified design is described which consists of four magnetostrictive
ferrite disk resonators
   /
2956
a broad band variable group delay equalizer  the equalizer has been
developed for use in fm microwave systems  it is inserted in the
signal path in long radio relay systems  the performance is adequate
for the transmission of frequency division multiplex telephony of
at least channels or subcarrier colour television transmission
   /
2957
comments on frequency pulling of maser oscillators  the physical
origin is illustrated of the theoretically predicted reduction in
frequency pulling with increasing number of beam molecules and reasons
are given for its failure to occur in practice
   /
2958
a solid state microwave amplifier and oscillator using ferrites
experimental results obtained with an oscillator based on the proposal
by suhl  the active element is a piece of magnetized ferrite at room
temperature
   /
2959
sensitivity of a self excited oscillator  theoretical and experimental
investigation of the characteristics of a valve feedback oscillator
suitable for nuclear resonance detection
   /
2960
crystal oscillators in communication receivers
   /
2961
unijunction transistor forms flip flop  the construction and performance
are described of a multivibrator circuit for a stable or monostable
operation see also  its active element is the double base diode a
terminal pn junction device
   /
2962
pulse generator uses junction transistors  a transistor circuit is
described giving pulses of duration at repetition rates of pulses
with internal delays of of
   /
2963
distortion in transistor amplifiers  an analysis of the distortion
in low level grounded emitter stages due to input circuit nonlinearity
and to variations of collector to base current gain
   /
2964
low frequency transistor oscillators  theoretical treatment of a
junction transistor oscillator for frequencies of a few  frequency
and amplitude stability conversion efficiency and the conditions
governing starting are considered  a practical circuit design is
derived and experimental results are given
   /
2965
build up of large signals with elimination of reflections in magneto
strictive storage lines  greater reliability and increased storage
capacity are obtained by substituting twelve energizing coils for
the usual one  with this arrangement a steel wire delay line can
be used  see also of
   /
2966
a transistor gating matrix for a simulated warfare computer  brief
description of a circuit devised in which used a matrix of point
contact transistors  amplification of signals was also achieved
   /
2967
signal enhanced delay line  to maintain pulse shape the high frequency
response of the delay line described is improved by selective amplification
   /
2968
pulse compression  a method is described for compressing frequency
modulated rf pulses ie shortening them and increasing their amplitude
by passing them through a delay distortion network consisting of
a chain of lattice quadripoles  the theory outlined is based on work
by caucer published posthumously  its practical application in the
field of radar should result in higher resolving power for a given
signal noise ratio
   /
2969
minimizing mismatch loss  simple formulae and curves are given
   /
2970
upper limits of output power in vacuum tube and transistor ac amplifiers
simple analysis and comparison based on idealized characteristics
   /
2971
stacked valve circuits  an analysis by means of feedback theorems
and modified equivalent circuits  application of the method to the
cascade amplifier and the cathode follower circuits is given in detail
   /
2972
single ended push pull output stages  the development of low dc resistance
pentodes and high resistance moving coil loudspeakers has made
possible the construction of transformerless output stages several
types of which are described  the paper is based on the work of w
aschermann and j rodrigues de miranda see of
   /
2973
a low frequency selective amplifier  the frequency is variable in
steps from to  the selectivity can be set up to  the amplifier is
dc coupled a twin t network shunted by a capacitor acts as a selective
network in the negative feedback line
   /
2974
pt pa unit  description of a band switching rf amplifier for and
which uses a pair of valves type pt in parallel
   /
2975
a broad band intermediate frequency amplifier for use in frequency
modulation microwave radio relay systems  a amplifier is described
which is suitable for the transmission of channel frequency division
multiplex telephony or subcarrier colour television signals in fm
microwave radio relay systems  a test tone noise ratio of is not
significantly degraded after transmission through five amplifiers
in tandem
   /
2976
watt audio amplifier  the circuit described includes small output
valves in parallel push pull connection
   /
2977
self balancing magnetic amplifiers of the differential feedback type
a magnetic amplifier for extending the range of aa moving coil ink
recorder is described
   /
2978
the use of transistors in airborne audio equipment
   /
2979
negative feedback transistor amplifiers  design data are given for
high fidelity af amplifiers
   /
2980
microwave amplification by maser techniques  elementary analysis
of maser operation including its application to wide band short
transit time amplification
   /
2981
demodulator limiter for control system signals  description of transistor
circuit for automatic control systems which acts as limiter during
modulation or demodulation
   /
2982
magnetically keyed phase sensitive demodulators  the operation and
performance of a pulse shaping circuit using magnetic reactors is
described  the properties of three types of phase sensitive demodulator
are compared  diode demodulators have linear characteristics magnetic
amplifier demodulators have high input impedance and transistor demodulators
combine good linearity with low noise level
   /
2983
transistorized phase discriminators  half wave and full wave phase
discriminators are described with two or three terminal dc outputs
an analysis of the operating characteristics of transistors in discriminator
circuits is given temperature stability and power limitations
are discussed
   /
2984
interferometry for the far infrared
   /
2985
infrared radiation and its detection  a comparison of the sensitivity
and time constant of available detectors of infrared radiation  thermal
detectors of thermocouple bolometer and pneumatic type and photoelectric
detectors are discussed
   /
2986
the lorenz number  the theory of the lorenz number of a conducting
crystal is developed for the band and one electron models of the
electron assembly  with certain approximations the lorenz number
is found to be equal to the mean square fluctuation of the thermoelectric
power
   /
2987
some scattering problems in conduction theory  an expression derived
for the scattering of electrons by inhomogeneous slowly varying strain
fields is applied to scattering by dislocations and stacking faults
   /
2988
free path formulae for the coefficient of diffusion and velocity
of drift of electrons in gases
   /
2989
free path formulae for the electronic conductivity of a weakly ionized
gas in the presence of a uniform and constant magnetic field and
a sinusoidal electric field  a general free path formula is given
for the drift velocity of electrons in a weakly ionized gas in a
sinusoidal electric field  most special cases of interest including
the magnetic deflection of an electron stream in a gas are readily
derivable from the general formula  the results find application
in microwave and ionospheric studies of the motion of electrons in
gases as well as in experiments on the magnetic deflection of an
electron stream  see also above
   /
2990
radio star ridges  the distinctive amplitude variations known as
ridges can probably be explained in terms of divergent lens effects
in the e region  see also of
   /
2991
oscillations in direct current glow discharges  experimental results
are given concerning the stable oscillations with the same period
which occur in the current and in the light emitted by the positive
column
   /
2992
mechanization in the presence of magnetic viscosity in  a mathematical
expression is derived for solving problems of magnetization of magnetically
viscous samples in particular those of cylindrical shape  see
also of
   /
2993
diffraction of electromagnetic waves by ribbon and slit  rigorous
solutions are presented for a wave incident on a plane normal to
the edge of the ribbon or slit but with arbitrary angles of incidence
and polarization  for diffraction by circular plate and hole see
of
   /
2994
diffraction of a spherical wave pulse by a half f plane screen  fourier
integral treatment for a point source
   /
2995
distortions of magnetic resonances by additional and excessive oscillatory
fields  a theoretical explanation is given of the shift of the
resonance frequency which occurs as a result of the presence of an
extraneous rf electric field  see also
   /
2996
the dependence of the amplitude of the first harmonic of nuclear
magnetic resonance absorption on the amount of detuning
   /
2997
equivalence between the line width and the rate of energy relaxation
in the inversion spectrum of ammonia
   /
2998
on the equilibrium configurations of oblate fluid spheroids under
the influence of a magnetic field
   /
2999
toroidal oscillations of a spherical mass of viscous conducting fluid
in a uniform magnetic field
   /
3000
theoretical treatment of the kinetics of diffusion limited reactions
the diffusion limited reaction has been solved for a random initial
distribution of a and b particles
   /
3001
a consideration of radio star scintillations as caused by interstellar
particles entering the ionosphere part daily and seasonal variations
of the scintillation of a radio star  part the accretion of interstellar
particles as a cause of radio star scintillations  an analysis is
made of measurements of scintillations of the rf source in cassiopeia
recorded at ottawa during at a frequency of  the data show certain
daily maxima occurring at solar times dependent on the date of the
year and grouped unsymmetrically in a way which suggests that they
are due to the infall of interstellar particles from outside the
solar system  the velocities of certain of these particles are derived
by simple applications of vector addition employing the known velocity
of the earth  see also of
   /
3002
the mullard radio astronomy observatory cambridge  the observatory
was formally opened in  two instruments then under construction were
a radio star interferometer for and a pencil beam system for investigating
continuous galactic radiation at the aperture synthesis technique
applied in the two systems is described  see also of
   /
3003
worlds largest radio telescope  an illustrated description of the
design and construction of the fully steerable paraboloid of the
jodrell bank instrument with details of the driving system and drive
control equipment
   /
3004
the distribution of the orbits of sporadic meteors  radio observations
at adelaide during are analysed  a distribution of orbits is derived
which is consistent with radar and visual observations in the northern
hemisphere
   /
3005
variations in the intrinsic strength of the quadrantid meteor shower
analysis of the occurrence rate of meteoric signals detected on a
vhf forward scatter east west path in canada  see also of
   /
3006
a theory of long duration meteor echoes based on atmospheric turbulence
with experimental confirmation  the experimental evidence is examined
with the conclusion that the theory does not accurately represent
the properties of meteoric echoes
   /
3007
meteor activity in the southern hemisphere  activity and radiants
of meteor showers are discussed and compared with similar data for
the northern hemisphere  see also above and of
   /
3008
ionospheric indices of solar activity  it is suggested that a simple
index based on e layer measurements at a single station is adequate
and that the additional effort required to provide the index based
on f layer measurements at three stations is not justified  see also
of minnis
   /
3009
observation of a new type of flare  a mass of very bright material
was ejected from a flare about from the suns limb  except for the
velocity the mass possessed all the properties of a small flare
   /
3010
the effective electrical constants of soil at low frequencies  a
possible explanation is presented for the large appa rent dielectric
constants which occur at frequencies of the order of
   /
3011
igy rocket program  an outline of the work of the igy subcommittee
of the us technical panel for rocketry  a table is given listing
organizations participating and their objectives
   /
3012
a possible troposphere ionosphere relationship  a relation is suggested
between f layer characteristics and the passage of meteorological
fronts through the troposphere  a hypothesis for dynamical coupling
between the two regions is outlined
   /
3013
electric field measurements in the stratosphere  above the exchange
layer the field decreases monotonically up to the limit of measurements
made in and  the measured and calculated values are in good agreement
   /
3014
electric field measurements above thunderstorms  in measurements
at heights of to above central florida a positive upward flowing
current of about was found
   /
3015
models of the lower ionosphere as may be inferred from absorption
results  values of deviative and nondeviative absorption and their
variations with cos are calculated for the d region models of nertney
of piggott unpublished and mitra and for the e region model of jones
of  satisfactory agreement with experimental results is found for
mitras model of the d region but not for jones model of the e region
   /
3016
a study of spread f ionospheric echoes at night at brisbane frequency
spreading  diurnal and seasonal variations in spreading of the penetration
frequency are compared with similar world wide data  the observations
are interpreted in terms of scattering from clouds of enhanced
ionization near the f layer maximum and a seasonal vertical movement
of these clouds is suggested the extent of which increases with latitude
parts
   /
3017
severe ionospheric storm  notes on the disturbances of august september
   /
3018
disturbances in the lower ionosphere observed at vhf following the
solar flare of february with particular reference to auroral zone
absorption  the effects of the flare on ionospheric scatter links
in the band at high latitudes are reported  an abrupt increase in
oblique incidence signal intensity occurring almost simultaneously
with the arrival of cosmic rays was following during during the next
three days by abnormally high levels at night and low levels during
the day  background cosmic noise measurements showed increased absorption
at night and greatly increased absorption during day light  the
penetration into the d region of moderately heavy solar atomic ions
is suggested as an explanation of the absorption phenomena
   /
3019
solar eclipse of june and its effect upon the ionosphere  the investigations
at delhi reported include vertical incidence ionospheric measurements
the recording of variations of sw and mf signals and the recording
of solar noise on  evidence of three distinct corpuscular eclipses
was obtained both on the ionization density of the f layer and on
the absorption in the nondeviating region  these were found to occur
and before the optical eclipse  theoretical arguments and past observations
indicate that these corpuscular emissions may have originated
from the so called m region of the sun
   /
3020
ionospheric research  note on signal strength changes during the
annular solar eclipse on and the control days for transmitters both
in south africa and in other countries
   /
3021
disturbances in the f and e regions of the ionosphere associated
with geomagnetic storms  the e and f layer variations which occur
during geomagnetic disturbances are examined for different phases
of the solar cycle and for a number of latitudes  the data are discussed
in relation to the electron drifts associated with geomagnetic disturbances
see also below
   /
3022
disturbances in the ionospheric f region associated with geomagnetic
storms  middle latitudes  disturbances at middle latitudes are divided
into negative and positive types characteristic of high and low latitudes
respectively  these results are discussed in terms of vertical
drift of electrons and the disturbance daily variations in the geomagnetic
field  the bearing of the dynamo current on seasonal and latitude
variations of disturbances is discussed  part of
   /
3023
ionospheric irregularities causing random fading of very low frequencies
ionospheric studies by the lunar technique  equipment operating
near ottawa comprises a transmitter keyed on for sec and off for
sec feeding a paraboloid via a horn and orthogonal dipoles with a
similar reflector feeding a dual conversion receiver and  synchronous
detection is used to give an af output signal equal in frequency
to the doppler shift of the signal reflected from the moon  preliminary
results indicate the presence of fading due to libration long and
short period faraday rotation and long term fading without faraday
rotation
   /
3024
the electrification of precipitation and thunderstorms  a review
article  cosmic rays radioactivity and other agencies produce ion
pairs which are transferred to cloud droplets or ice crystals and
establish a droplet charge distribution greatly influenced by differences
in conductivity for positive and negative ions  rain formed from
these droplets may be electrified usually both positive and negative
drops being present  processes are considered which charge this rain
and and may eventually lead to a lightning stroke  the conditions
necessary to establish gross free charge distributions by regeneration
are specified and shown to be met under frequently occurring meteorological
situations  references
   /
3025
rotational temperatures measured in aurorae at churchill manitoba
the measurements indicate there is no latitude effect  a vertical
temperature gradient of is deduced  see also of
   /
3026
a study of the audio frequency radio phenomenon known as dawn chorus
experimental evidence supports the hypothesis that dawn chorus signals
are generated by the entry into the ionosphere of clouds of positively
charged particles of solar origin  propagation appears to take place
in the extraordinary magneto ionic mode along the earths magnetic
lines of force
   /
3027
removal of heat from sealed miniature equipment  experimental investigation
has shown that the most satisfactory way of dissipating the
heat generated internally is by providing thermal conduction paths
from the heat sources to the front panel
   /
3028
utilizing the suns energy  report on progress in the development
of solar batteries of the si p n junction type with description of
experimental installations in england
   /
3029
a stabilized dc power supply using transistors  a mains operated
unit is described which provides an output voltage variable from
to at currents of up to
   /
3030
germanium rectifiers as electronic components  discussion of advantages
and applications  cooling methods and overload characteristics are
considered
   /
3031
a low voltage stabilizer employing junction transistors and a silicon
junction reference diode
   /
3032
voltage regulator uses multi vibrators  voltage changes vary the
frequency of an astable transistor multivibrator and the average
value of the load voltage is thus kept constant
   /
3033
multichannel drives for transmitters and receivers in the hf band
methods of tuning accurately to a prescribed frequency are described
as applied to a diversity oscillator with manual tuning an automatically
tuned airboard received transmitter drive
   /
3034
monitoring the modulator  a circuit for monitoring the output of
a high power modulator on a pair of headphones
   /
3035
odd binary asynchronous counters
   /
3036
a one microsecond adder using one megacycle circuitry
   /
3037
high speed computer stores megabits  design and performance details
of the lincoln computer are given
   /
3038
an iterative analogue computer for use with resistance network analogues
   /
3039
circuitry and characteristics of a repeating electronic analogue
computer  description of a computer for solving engineering problems
a hyperbolic field tube is used as multiplier
   /
3040
the error effect of the operation amplifier in analogue computers
the various errors and their sources are discussed and some methods
of automatic correction are described
   /
3041
a multiplier based on the two parabola method  the method of operation
is described and the accuracy obtainable is shown by some examples
of calculations
   /
3042
the utilization of domain wall viscosity in data handling devices
   /
3043
transistors in current analogue computing  a comparison of variable
current and variable voltage analogue computing techniques shows
that transistors are particularly suitable for the former  low power
low frequency transistors in direct coupled amplifiers which may
be used in computers are described
   /
3044
electric correlators  typical applications of electric correlating
devices are discussed and the operation of various types of these
is described  details are given of a static type translator using
transistors and crystal diodes as nonlinear switching elements
   /
3045
a time division multiplier
   /
3046
analogue multipliers and squarers using a multigrid modulator
   /
3047
a small coincident current magnetic memory
   /
3048
the role of printed wiring in high fidelity  the advantages of printed
wiring techniques are summarized
   /
3049
a design method for wide band balanced and screened transformers
in the range  leakages and winding capacitances are accurately and
independently controlled and a high degree of winding balance is
attained with an insertion loss of about db
   /
3050
simplified pulse transformer design  an outline of design techniques
for low and high power pulse transformers
   /
3051
the frequency lock afc circuit  noise free operation of the system
is analysed and its performance at low signal noise ratios is considered
a theory of the system operation under the latter conditions is
developed from an examination of the tracking errors resulting from
noise and changes in signal frequency  practical results obtained
are in agreement with this theory
   /
3052
a novel electronic transmit receive switch  a type valve capable
of withstanding between grid and cathode isolates the receiver from
the transmitter tank circuit
   /
3053
stabilization of current operated transistor switching circuits
a method is given for calculating the parameters of simple compensating
circuits
   /
3054
the transistor as a speech path switch  the suitability of transistors
is discussed and some methods of using them for this purpose in telephone
systems are described
   /
3055
complexity in electronic switching circuits
   /
3056
future circuit aspects of solid state phenomena  several phenomena
such as superconductivity molecular amplification magnetic effects
in semiconductors and the nonlinear capacitance of pn junctions are
discussed from the point of view of the circuit designer  new devices
will to an increasing extent be based on controlled inhomogeneity
   /
3057
the influence of electromagnetically coupled systems  compound systems
consisting of a primary electromagnetically coupled to a secondary
system are considered  the equations obtained are applied to examples
of magnetic coupling and a conducting diode
   /
3058
a new technique in ferrite phase shifting for beam scanning of microwave
antennas  in the device described a longitudinal magnetic field is
applied to a ferrite rod in a rectangular waveguide excited in the
te mode  phase shifts of over and variations in transmitted power
of less than have been obtained with aa field of oersteds  see also
of
   /
3059
computation of crystal admittance  the results of a digital computer
program designed to calculate the admittance of a coaxial crystal
for various values of video resistance spreading resistance and barrier
capacitance over the range are given  comparisons with available
measurements are made
   /
3060
method of obtaining pressure and temperature insensitive microwave
cavity resonators  methods using invar walls with steel or brass
end plates for te cavities are unsatisfactory due to hysteresis effects
improved techniques are described for fixed frequency resonators
which have temperature coefficients less than per  the pressure coefficient
is less than in per millibar
   /
3061
retardation effects caused by ferrite sample size on the frequency
shift of a resonant cavity  expressions are derived using perturbation
theory for the frequency shift of a circularly polarized resonant
microwave cavity due to insertion of a small ferrite sample
   /
3062
simplified design of impedance matching networks  a step by step
method of impedance transformation is described  the formation of
and networks from the basic l section and some complex matching networks
for particular applications are discussed
   /
3063
super selectivity with crystals  constructional details of a lattice
type if filter with two crystals the response curve is symmetrical
   /
3064
a frequency independent microwave attenuator with largely constant
phase shift  a waveguide attenuator of the rotary vane type is described
and calibration and error curves are given  close agreement of measured
attenuation with theoretical values was obtained in attenuators for
the range of
   /
3065
the transactor  the two terminal constant current and constant voltage
generators used in equivalent circuits of active networks are replaced
by transmission type active elements called transactors  the relations
between variants of this element are established
   /
3066
theory of two phase networks  phase splitting networks as used in
ssb modulation systems are discussed and calculations by approximation
methods are described
   /
3067
phase shift oscillator indicates radar range  firing range information
is conveyed by a variable af note
   /
3068
high order harmonics for x band oscillator stabilization  a simplified
phase locking stabilization technique for microwave oscillators
harmonic orders up to about are used
   /
3069
the simultaneous generation of two oscillations in one oscillator
and the stability of the difference frequency  the operating conditions
are determined which are required for the simultaneous generation
of two different frequencies in a valve feedback oscillator see
experimental results are discussed
   /
3070
grid diode sawtooth generator  description of a simple timebase circuit
with wide frequency range
   /
3071
experimental and theoretical investigation of semiconductor hall
effect generators
   /
3072
silicon transistor crystal oscillators have high temperature stability
outline of circuit design considerations and discussion of experimental
results
   /
3073
difference counters  two examples are given with maximum counting
rates pulses and pulses  the design of a decimal difference counter
is outline
   /
3074
direct coupled amplifiers  a method is described of artificially
matching valves to obtain improved mutual compensation for the effects
of normal heater supply voltage changes  adjustment is easier than
selecting naturally matched pairs of valves and considerably better
balance is obtained
   /
3075
a if amplifier for wide band microwave links
   /
3076
direct coupled amplifiers with junction transistors  a balanced dc
amplifier circuit is analysed and the theory of its operation is
developed on the basis of the work by abers and moll  the problem
of balancing the circuit with ideal and with commercial type transistors
is considered and practical design formulae are derived
   /
3077
masers and reactance amplifiers basic power relations  an alternative
derivation based on circuit theory of the expressions of manley and
rowe  the power relations involve only the source and load frequencies
and are independent of the specific characteristics of the nonlinear
device
   /
3078
maser noise measurement
   /
3079
new ferrite microwave amplifier  an experimental solid state amplifier
using a ferrite material as the active element is described  the
device is suitable as an amplifier of very weak microwave signals
see also of
   /
3080
the reaction field and its use in some solid state amplifiers  the
theory of the maser is presented in terms of the radiation reaction
field produced in a cavity or waveguide by the presence of the electromagnetic
moment of the sample being investigated  two amplifiers are
discussed which use the reaction field in different ways from the
usual solid state maser
   /
3081
the pn junction on a variable reactance device for fm production
a transistor modulator for a carrier frequency is described which
gives good fm with negligible am change in modulating signal produces
a deviation of
   /
3082
the influence of a strong magnetic field on the dielectric constant
of a diamagnetic fluid
   /
3083
formulae for dielectric constant of mixtures  formulae are tabulated
with references and shown to be special cases of a general fundamental
formula  an exception is the lichtenecker type of formula possibly
owing to incorrect assumptions
   /
3084
the second order effect of free electrons on lattice conduction
second order perturbation theory in conjunction with the usual treatment
of electron phonon interaction allows us to calculate the correction
to the first order result for the scattering of phonons by electrons
it is shown that the second order term is much smaller and therefore
negligible  this justifies the use of the first order theory in the
treatment of the interaction in metals and semiconductors
   /
3085
a method of calculation of electrical conductivity  using relaxation
theory a general solution is obtained for the electric current density
irreversibility is then introduced so that practical cases may be
considered  a perturbation approximation gives the same result as
that based on the bloch theory
   /
3086
a note on the energy gap model of superconductivity
   /
3087
gauge invariance and the energy gap model of superconductivity  on
the elementary theory of thermoelectric phenomena  all the relations
between the thermoelectric parameters are deduced from physical properties
rather than by means of mathematical transformations  the sources
of the heat and emf developed are indicated
   /
3088
the plasma resonator  the interaction between an ionized gas column
and an electromagnetic wave in a waveguide is studied at cm  effects
examined include the influence of the discharge current gas collisions
decay times of electron density and modulation of the rf power
   /
3089
new effects of an anxiliary electrode on a discharge at low pressure
an auxiliary electrode close to the cathode provides a means of sensitive
control of the discharge  optimum operational conditions were
found for a range of discharge parameters  low frequency noise may
be suppressed by an electrode of wire gauze
   /
3090
theory of secondary emission  the elementary theory of secondary
electron emission has been generalized and modified to incorporate
results of recent measurements of the range energy relation and the
dissipation of energy by slow electrons iin solids  these modifications
give considerably improved agreement between the theoretical and
experimental universal reduced yield curves
   /
3091
satellite electron theory of ferromagnetism  antiferromagnetism and
related phenomena  a theory based on classical concepts is developed
to show the electronic nature of ferromagnetism  magnetic properties
of transition metal oxides are briefly discussed
   /
3092
a note on the ground state of antiferromagnetism  kasteleijns method
of obtaining the lowest energy state is generalized for the cases
of two and three dimensional lattices
   /
3093
on the reflection and refraction of magnetohydrodynamic waves
   /
3094
asymptotic formulas for diffraction by parabolic surfaces  asymptotic
solutions to the wave equation are found at a boundary consisting
of a paraboloid of revolution or a parabolic cylinder  the results
are applied to the reflection at such surfaces of incoming plane
waves or divergent waves from a point or line on the axis of the
surface
   /
3095
double modulation system for narrowing electron resonance absorption
lines  a method for observing electron resonance absorption on an
oscilloscope screen by modulating both the magnetic field and the
klystron frequency  the apparent line width can be reduced by a factor
of relative to the true line width
   /
3096
microwave studies of the internal motion and the structure of methyl
amine
   /
3097
potential barrier and molecular structure of methyl mercaptan from
its microwave spectra
   /
3098
microwave spectrum of and dependence of quadrupole coupling constant
on the vibrational state
   /
3099
proposal for a nuclear quadrupole maser  it is suggested that certain
substances exhibiting pure quadrupole transitions have the requisite
properties for maser operation  the differences between masers based
on these substances and on paramagnetic solids are discussed
   /
3100
fluctuations in amplification of quanta with application to maser
amplifiers  expressions for the probability distribution of quanta
for the average values and for the fractional fluctuation are developed
and applied to maser type amplifiers
   /
3101
the reaction field and its use in some solid state amplifiers
   /
3102
radio frequency zeeman effect in o  by the molecular beam magnetic
resonance method the ratio of the value of the rotational magnetic
moment to that of the electron spin moment is found to be the ratio
of the g value of the unpaired electron spin moments in to that of
the free electron spin moment is
   /
3103
the cloud chamber  the theory and application of the wilson cloud
chamber are outlined and its m modification by gabor and hampton
is briefly described
   /
3104
sources of radio noise on the planet jupiter  daily records made
from december to march at gainesville florida at suggest that there
are two localized sources on jupiter and that jupiter is surrounded
by an ionosphere of electron density ie comparable with that of the
earths ionosphere
   /
3105
radio emission from the comet  report of observations carried out
at the radio observatory stockert
   /
3106
a consideration of radio star scintillations as caused by interstellar
particles entering the ionosphere part the kind number and apparent
radient of the incoming particles  discussion of results given earlier
indicates that the interstellar particles must be hydrogen atoms
   /
3107
the proportion of umbra in large sunspots  the ratio of umbral area
to whole spot area is evaluated and shown to vary significantly with
the position of the sunspot in the solar cycle
   /
3108
detection of submillimetre solar radiation  preliminary results are
presented which indicate regions of transmission in the wavelength
range
   /
3109
short time transients in solar noise  histograms have been made from
observations at dwingeloo holland  rebers theory that there is a
linear relation between wavelength and duration of pips is not confirmed
at this frequency
   /
3110
a review of recent investigations into sunspot cycles  summaries
of and comments on selected published papers and ccir documents relating
to predictions of solar activity for use in ionospheric work
   /
3111
occultation of a radio source by the solar corona  measurements of
radio noise flux from taurus a when its angular separation from the
sun is very small suggest that partial wide angle scattering has
occurred due to electron density irregularities in the solar corona
   /
3112
a solar flare on november  visual and radio observations during the
flare are presented  anomalies in the radio observa tions are accounted
for by small regions of the flare remaining enhanced for several
hours after the main effect had subsided
   /
3113
centimetre wave observations of the solar eclipse of june  radiation
measurements at disclose an ellipticity in the brightness distribution
of the suns disk with the greatest extent in the equatorial plane
   /
3114
proper and improper use of statistics in geophysics  a discussion
of some of the peculiarities of the geophysical sciences together
with their implications for statistical methods particularly for
the correlation coefficient is given  the discussion is illustrated
by an analysis of a recently published paper  in conclusion some
advice e on the use of correlations is offered
   /
3115
hydromagnetics and the earths inner core  it is suggested that the
terrestrial magnetic field is produced in an inner liquid core permeated
by a magnetic field of  secondary motions partly hydromagnetic occur
in an outer surrounding liquid region and the field emerging from
the complete core is the small field measured at the earths surface
   /
3116
method of magnetic storm forecasting from the activities of flares
accompanied by the solar radio noise outbursts  a statistical examination
has been made of the occurrence of magnetic storms solar flares
and radio noise outbursts on  the correlations discovered are applied
to the problem of forecasting magnetic storms during the igy
   /
3117
ionospheric studies in india during the international geophysical
year
   /
3118
propagation and the international geophysical year  summary of phenomena
which affect hf and vhf propagation  some methods of observation
are suggested to the radio amateur
   /
3119
artificial satellites of the earth  extracts are given from radio
published before the launching of the ussr satellites see eg of and
results of observations made at various stations in the uk are summarized
   /
3120
tracking the man made satellite  an outline of the preparations for
launching and observing the us satellite including the use of an
electronic computer for calculating the orbit from observational
data
   /
3121
the use of surface weather observations to predict the total atmospheric
bending of radio rays at small elevation angles
   /
3122
the detection and measurement of water droplets  a method of obtaining
a permanent record of drop size is described it can be used for droplets
of less than diameter
   /
3123
the threefold structure of the atmosphere and the characteristics
of the tropopause  the atmosphere in the northern hemisphere is divisible
into three regions north of the polar front jet south of the sub
tropical jet and the region between the jets  each region has a typical
vertical temperature structure in the stratosphere and troposphere
and a characteristic tropopause height
   /
3124
the effect of the equatorial electro jet on the ionospheric e and
f layers  the occurrence of low values of at ibadan is correlated
with variations in the horizontal and vertical components of the
earths field and with f layer parameters  an immediate relation is
indicated between the electrojet the production of equatorial e
and vertical drifts in the f layer
   /
3125
dynamical structure of the ionospheric f layer  formulae giving diffusion
velocity and its divergence are derived for the electron ion gas
in the ionosphere on the assumption of a linear temperature gradient
the change in electron density distribution is then calculated using
these formulae for different models of the ionosphere  comparisons
of the calculated and observed changes in the f layer show that bradburys
rather than chapmans theory is more appropriate
   /
3126
on the occurrence of the f layer in japan part  a statistical analysis
based on vertical incidence soundings over a sunspot cycle shows
annual seasonal and diurnal variations  good correlation is demonstrated
between frequency of occurrence and sunspot number
   /
3127
some further observations from aircraft of frost point and temperature
up to  measurements at various altitudes taken in flights over southern
england in are tabulated  good general agreement is obtained with
measurements
   /
3128
variation with height of rainfall below the melting level  radar
measurements in warm front conditions suggest that there is uniformity
of drop size distribution and rate of rainfall with height once meeting
is complete and terminal velocity has been attained
   /
3129
on a special aspect of the condensation process and its importance
in the treatment of cloud particle growth  the distribution of water
vapour around a droplet depends upon the ratio of droplet size to
a factor determined by the equilibrium rate of exchange of molecules
between the water surface and the water vapour
   /
3130
electric charge separation in subfreezing cumuli  a theory of the
electrification of thunderclouds on charge separation occurring when
supercooled droplets impinge on ice particles the theory can explain
observed charge separations without assuming the presence of large
hailstones
   /
3131
the measurement of world wide thunderstorm activity at a single locality
counts of atmospheric impulses received in england in the band
are found to be similar to records of integrated noise in california
in the band see  it is inferred that world wide thunderstorm activity
was recorded in both experiments
   /
3132
preliminary discharge processes in lightning flashes to ground  the
first return stroke is usually preceded by three successive and distinct
discharge processes lasting several hundred milliseconds  the characteristics
of the field changes in these preliminary stages are analysed
in terms of the distance of the source  probable mechanisms are discussed
   /
3133
the accuracy of the determination of reflection heights and distances
of atmospherics on the basis of their waveform  the errors in calculating
reflection height h and distance d of atmospherics are investigated
as a function of the ratio hd and of the reflection modes  a recorded
waveform is analysed and results are tabulated  see also
   /
3134
diurnal variation in the occurrence of dawn chorus  a histogram of
observations made at frequencies between and on days between january
and july at college alaska shows a maximum at local time which appears
to be related to geomagnetic latitude
   /
3135
choke or capacitor input  basic differences of operation and application
of the two systems of power supplies are explained
   /
3136
design of transistor regulated power supplies  two applications of
the circuit are described one giving at and the other at  output
resistance is about and ripple on full load is less than it
   /
3137
germanium and silicon power rectifiers
   /
3138
a multipurpose electronic switch for analogue computer simulation
and autocorrelation applications  abstract
   /
3139
an error analysis of electronic analogue computers  abstract
   /
3140
a wide band multiplier using crystal diodes  the quarter square multiplication
is used the squaring being performed by networks of biased
ge diodes in the feed back paths of standard computing amplifiers
these networks have phase shifts of less than at and the errors of
the multiplier are less than of maximum output
   /
3141
a new storage element suitable for large sized memory arrays the
twistor  use is made of the wiedemann effect whereby a torsion applied
to a magnetic wire shifts the preferred direction of magnetization
into a helical path  there three modes are suggested in using the
effect for storage cells the coincidence of circular and longitudinal
magnetic fields inserts information into the wire as a polarized
helical magnetization operation similar to the coincident current
toroid with the wire acting as its own sensing winding the wire is
not twisted but the screw sense of the flux path is related to the
current polarities  equations relating to the switching performance
of a twistor are derived and a description of an experimental bit
array is given
   /
3142
the ibm edpm memory system
   /
3143
a new type of ferroelectric shift register  ferroresonant circuits
for digital computers  an analysis of bistability in ferroresonant
circuits and the practical application to high frequency operation
present limit  circuits are shown for a shift register stage binary
counter and input logical adder
   /
3144
logic circuits for a transistor digital computer
   /
3145
junction transistor switching circuits for high speed digital computer
applications
   /
3146
an electrolytic tank as an analogue computing machine for factorizing
high degree polynomials  by means of simple measurements all the
roots of a polynomial as high as the degree can be located to within
about
   /
3147
pulse generator and high speed memory circuit
   /
3148
the development of a new method of circuit analysis in ladder networks
the method outlined is applied to networks consisting of tandem connected
l sections calculations are simpler than in conventional methods
   /
3149
explicit formulas for tschebyscheff and butterworth ladder networks
a new set of simple formulae has been found for the element values
in a tchebycheff or butterworth ladder network which apply when the
degree of the denominator of the transfer function is odd and the
reflection coefficient has zeros alternating in the left and right
half planes
   /
3150
rc filters and oscillators using junction transistors
   /
3151
the distortion of frequency modulated oscillations caused by rc networks
general remarks on distortion factors of filters not accurately
tuned to the carrier which have a skew symmetric phase characteristic
and a mirror symmetric amplitude characteristic
   /
3152
mutual correlation of fluctuation type interference at the output
of frequency filters  the method is discussed of determining the
interference correlation function for two filters forming the loads
of a two frequency channel receiving system with or without detector
   /
3153
proposal for a solid state radio frequency maser  a brief comment
on conditions which are necessary to construct a maser using zeeman
levels of the pure quadrupole spectrum
   /
3154
characteristics of the beam type maser  velocity distribution of
molecules in a beam type maser is analysed by an approximate method
the average velocity of the molecules is much less than the most
probable velocity when the power level and focusing voltage are low
the relations between amplitude focuser voltage and frequency agree
well with experimental results to be detailed in part
   /
3155
solid state oscillator for microwave frequencies  an experimental
solid state device using gadolinium ethyl sulphate an ionically bound
paramagnetic salt as the active element is described  see of scovil
et al
   /
3156
the influence of a high frequency gas discharge on the frequency
of a self excited short wave oscillator stage  continuing earlier
investigations further tests were made with a oscillator under various
conditions of discharge coupling and magnetic field  characteristic
curves indicating a linear relation between frequency and anode voltage
are obtainable  the interpretation of the observations is discussed
   /
3157
polyphase oscillators  the frequency stability and freedom from harmonics
is greater for single phase than for symmetrical polyphase oscillators
   /
3158
phase generator has resistive shifter  the generator operates over
a frequency range and supplies a pair of sinusoidal voltages with
an accurately known phase relation that is continuously adjustable
over
   /
3159
designing oscillators for greater stability  methods of improving
the frequency stability of an oscillator which can be divided into
an amplifier and a feedback network are described and examples are
given
   /
3160
simultaneous pulled oscillations in a triode oscillator incorporating
two oscillatory circuits  simultaneous oscillation at two frequencies
is possible and owing to mutual pulling both frequency and amplitude
modulation occur  a physical explanation of the pulling of a nonlinear
oscillator by an external input signal is given
   /
3161
second order nonlinear systems  in these systems where time is not
explicitly shown the four space is split into a displacement subspace
and a velocity subspace the two being related by a hypercone in a
transformation  singularities of integral curves and certain shock
phenomena are discussed and the analysis is applied to two types
of multivibrator
   /
3162
pulse generator and high speed memory circuit
   /
3163
cathode coupled flip flop  a reliable design procedure
   /
3164
analysis of cathode coupled free running multivibrator  a quantitative
equivalent circuit analysis valid for frequencies where the interelectrode
capacities can be neglected gives results in good agreement with
experiment
   /
3165
high speed flip flops for the millimicrosecond region
   /
3166
transient analysis of second order flip flops  a mathematical analysis
of the trigger sensitivity and switching speed of flip flop circuits
whose action can be represented by a second order differential equation
the method is applied to a point contact emitter input transistor
flip flop
   /
3167
a sawtooth crystal calibrator  circuit and construction details of
a sawtooth generator triggered from a crystal and giving detectable
harmonics up to
   /
3168
feedback coupling in circuits with crystal triodes  circuit design
methods are described and the formulae derived are tabulated
   /
3169
binary decimal counter operates at mcs  a design of counter which
produces one output pulse for every ten input pulses is described
it uses logical and gates in a feedback loop
   /
3170
statistical fluctuations and optimum transfer functions of a counting
rate meter  equations are derived to obtain the optimum response
conditions and suitable circuits are described
   /
3171
an amplifier for ac bridges  the requirements of an amplifier for
ac bridges working to an accuracy of one part in ten thousand or
better from power frequencies to audio frequencies are discussed
an amplifier to meet in part these requirements is described and
figures are given for its performance
   /
3172
a uhf wide band amplifier  description of the design of a amplifier
with bandwidth about for program distribution
   /
3173
a feedback circuit equivalence  transfer network representations
and their transformations are used to show that the feedback in
a bootstrap amplifier with shunt feedback may be considered either
positive or negative without inconsistency
   /
3174
a simple shaft digitizer and store  a shaft position encoder of simple
construction for analogue to digital conversion is described
   /
3175
some applications of square loop ferrite cores to telecommunication
switching
   /
3176
high speed gating circuit using the beam deflection tube
   /
3177
the approximation of special frequency laws by means of tables of
frequency functions  an approximation method facilitating the synthesis
of two pole and quadripole networks is described
   /
3178
admittance impedance and scattering matrices  the concepts and their
interrelation are defined
   /
3179
analysis and synthesis of electrical circuits by means of an electrolyte
tank  experimental procedure for solving network problems is described
   /
3180
effects of x ray irradiation on the frequency temperature behaviour
of at cut quartz resonators  results for resonators fabricated from
natural quartz synthetic quartz grown on several different cuts of
seed plates and synthetic quartz containing al or ge impurity are
reported
   /
3181
tolerances of quartz crystals for filters and their measurement
methods for measuring series resonance and crystal inductance are
indicated
   /
3182
negative impedances and gyrators  survey of characteristics and classification
of the various types of impedance inverter and gyrator  their
realization in the form of transistor circuits is discussed  see
of
   /
3183
stability criteria for linear systems and realizability criteria
for rc networks  a new set of stability criteria in linear systems
is drived about half of the hurwitz criteria can be neglected when
certain of the coefficients of the characteristic equation are positive
the conditions for realizability of rc networks are closely related
to the stability and aperiodic criteria and are given in the form
of polynomial coefficients
   /
3184
basic properties and characteristics of a synchronous filter  the
operation of integrating devices used for improving signal noise
ratio is discussed  a simple circuit with a long open circuited
line as store is analysed
   /
3185
dynamic core behaviour and magnetic amplifier performance  discrepancies
between theoretical analyses and measurements of magnetic amplifier
performance are attributed to excessively simplified representations
of core behaviour  experimentally acquired knowledge of core flux
characteristics is used to predict the operation of amplifier systems
   /
3186
reduction of the distortion of pulse fronts in transistor video amplifiers
methods are described for reducing the distortion of leading
edges caused by diffusion and other effects in the transistor base
region  compensating circuits are analysed and phase and amplitude
response curves are given
   /
3187
compensation for changes in base to emitter voltage with temperature
an economical method of compensating power transistor circuits consists
including in the emitter circuit metallic resistors having small
positive temperature coefficients
   /
3188
dc amplifier using transistors and a silicon bridge modulator  matched
si junction diodes are used in a bridge modulator to convert the
input to ac which is then amplified by transistors and detected
the design is suitable for measuring dc inputs of mv and or more
   /
3189
transistor class b push pull stages  the relative merits of single
ended and symmetrical output stages are discussed  in general the
single ended circuit offers considerable advantages
   /
3190
feedback arrangements in transformerless push pull output stages
different methods of applying negative feedback to single ended and
symmetrical class b circuits are discussed
   /
3191
measurement of noise in a maser amplifier  measurements on an beam
maser whose cavity and input and output loads were cooled to near
liquid nitrogen temperature yielded a noise figure of based on room
temperature as compared with a theoretical figure of
   /
3192
computation of noise figure for quantum mechanical amplifiers  an
expression is derived in terms of the physical quantities of the
electromagnetic structure and of the paramagnetic salt used
   /
3193
theory of a three level maser
   /
3194
gain bandwidth and noise in maser amplifiers  a theoretical study
reveals that the optimum gain bandwidth product of the two port maser
is only half that of the circulator maser for the same basic cavity
the optimum noise figure is the same if some bandwidth is sacrificed
in the two port maser  practical considerations may however make
the latter competitive
   /
3195
experimental determination of the noise figure of an ammonia maser
an outline of the technique of measurement is given
   /
3196
modified wkb approximation for bothes differential equation in diffusion
theory
   /
3197
equipartition of energy and local isotropy in turbulent flows  homogeneous
turbulence was produced experimentally and experiments showed
that the turbulence became isotropic at a faster rate than equipartition
of energy occurred  other experiments where approximately isotropic
turbulence was subjected to deformation indicated that even at high
reynolds number the deformation in a shear flow can cause anisotropy
the connection of the investigation with turbulent flows in general
is discussed
   /
3198
barrier layer photo emf of photo electric elements with dyestuffs
tests were made on photo elements consisting of dye stuffs deposited
on a quartz plate clamped between semi transparent electrodes of
pt au or rh  three different types of assembly were transversely
illuminated in most cases a positive photo emf was obtained
   /
3199
on the nature of the electron  in this paper the concept of the electron
as a fundamental particle of modern physics is discussed in relation
to paulis exclusion principle wave mechanics the uncertainty principle
and relativity
   /
3200
the charge density near a sharp point on a conductor  the idea that
surface charge tends to infinity at convex sharp points on conductors
and to zero at convace points is investigated on electrostatic principles
it is found that the problem has not been solved a new attempt
is made using potential theory methods from which a fairly general
solution is obtained
   /
3201
evaluation of transport integrals for mixed scattering and application
to galvanomagnetic effect  the johnson whitesall evaluations of the
conductivity integrals for mixed scattering have been extended to
allow their application to the high mobility semiconductors  applications
in the analysis of hall effect corbino magnetoresistance and thermomagnetic
phenomena as functions of magnetic field are illustrated
   /
3202
interaction between waves and electrons with some remarks on superconductivity
discussion of interactions occurring between elastic waves
and free electrons in metal particularly below the debye temperature
   /
3203
silent electric discharge at low frequency in air using insulating
electrodes  note on the joshi effect and the variation or discharge
current as a function of applied voltage using beeswax electrodes
in dry air irradiated by light
   /
3204
three dimensional potential well  the possibility of generating potential
wells having depths of the order of thousands of electron volts
is discussed
   /
3205
variation of inductance by dielectrics in particular plasmas  a qualitative
interpretation of the frequency changes in oscillatory circuits
which are coupled to electrodeless gas discharges  see eg above
   /
3206
analysis of multivelocity electron beams by the density function
method  mathematical techniques useful in the solution and interpretation
of the density function equations as applied to multivelocity
electron beam problems are presented with some conclusions about
the nonconservative nature of signal or noise propagation along a
multivelocity beam  the paper serves as a background for a detailed
calculation of noise propagation through the gun region of an electron
beam
   /
3207
density function calculations of noise propagation on an accelerated
multivelocity electron beam  the propagation of noise fluctuations
through the low voltage multivelocity region immediately in front
of the potential minimum of a diode or electron beam has been computed
despite the absence of any conventional loss elements two noise
parameters or measures of the noise fluctuations when the beam is
passed through a multivelocity region are significantly different
at the output from those at the input  changes are such as to lower
significantly the minimum noise figure of a microwave valve
   /
3208
the elastic scattering of electrons  an examination of basic theory
in particular the rutherford formula with reference to experimental
results
   /
3209
theory of secondary electron emission by high speed ions  a new theoretical
treatment shows that the yield of secondaries is proportional
to the rate of energy loss of the incident particles and is independent
of work function conductivity and other bulk properties of the metal
the theory explains the experimental observations and its application
to general problems of electron escape and capture is discussed
   /
3210
estimate of the time constant of secondary emission  energy considerations
allow a simple estimate to be made of the time constant of secondary
emission
   /
3211
ionization by positive ions  a method of measuring the ionization
cross section of atoms is described in which electrons are collected
from single collisions of an ion beam passing through a gas at low
pressures  measurements are given for twenty three cases over energy
ranges approximately and to
   /
3212
plasma oscillations in a steady magnetic field circularly polarized
electromagnetic modes  the propagation of em waves in the direction
of the field is considered  by taking account of the thermal motion
of electrons results are derived which differ markedly from those
of the appleton hartree electromagnetoionic theory near the cyclotron
resonance frequency
   /
3213
notes on the ground state of anti ferromagnetism  the conclusions
reached by earlier investigators are compared with those which result
from the spin wave theory see  the discrepancies are briefly discussed
   /
3214
general solutions of equations of a classical nonconservative electromagnetism
   /
3215
electromagnetic potentials in a heterogeneous nonconducting medium
for em fields in a stationary nonconducting medium isotropic or anisotropic
the dielectric constant and permeability of which are given
point functions the general theory of representations in terms of
scalar and vector potentials and of hertzian potentials is developed
   /
3216
tensor theory of gyromagnetic power  general linear relations for
non absorbing media are derived  the influence of symmetry upon tensor
equations and the effect of magnetic anisotropy on em wave propagation
is examined
   /
3217
electromagnetic waves in nearly periodic structures  the theory of
simple harmonic electromagnetic waves in a nearly periodic structure
of the type used in linear accelerators is discussed by an expansion
in a series of appropriately defined transmission modes of the field
in a unit cell of the structure  the possibility of the expansion
being assumed it is shown that the coefficients can be expressed
as integrals of the field over the input or output apertures of the
cell  the modification to the corresponding solution in the strictly
periodic structure can be calculated by perturbation theory  in the
first approximation the structure can be represented by a series
of four terminal networks and the voltages and currents in these
can be defined in such a way that the relevant parameters vary smoothly
in the neighbourhood of resonance
   /
3218
optical detection of magnetic resonance in alkali metal vapour  the
apparatus is described together with experimental conditions under
which signals have been observed  a possible application of the technique
is the measurement of weak magnetic fields
   /
3219
heterodyne detection of free precession in nuclear magnetic resonance
details of a method applied to proton resonance in solutions
   /
3220
narrowing effect of dipole forces on inhomogeneously broadened lines
observations of the effect in mn ferrite and yttrium iron garnet
are described  the theory for cases in which the spatial period of
the inhomogeneity is large compared to atomic distances and is either
short or comparable to sample size is discussed and its applications
are considered
   /
3221
dielectric rod waveguide cells for microwave spectroscopy  the calculation
of the distribution of microwave power around a quartz rod excited
in the dipole mode enabled rod sizes to be selected for cells covering
the range  teflon windows were found to be satisfactory  see also
of the
   /
3222
theory of a three level maser  a complete theory is discussed for
a gaseous system with an extension to paramagnetic solids
   /
3223
an attempt to detect linearly polarized radio emission from the galaxy
a paraboloidal reflector was used at a frequency of with receiver
bandwidth of  plots of position angle of the plane of polarization
against time are given for regions near and show that its variation
is in the direction to be expected from the ionospheric data
   /
3224
relative intensities of the four principal rf sources observed at
a wavelength of cm note on rf source sagittarius a  some rf sources
have been located during observations of the milky way region made
by means of the new radio telescope at dwingeloo netherlands  special
studies have been made of five of these in class a cygn a taur a
virg a and sgtr a and the equivalent temperatures have been determined
   /
3225
the effects of incomplete resolution on surface distributions derived
from strip scanning observations with particular reference to an
application in radio astronomy  the limitations of one dimensional
scanning methods for measuring surface distribution particularly
that of radio brightness over the suns disk are discussed
   /
3226
tests on a model of an aerial for use in radio astronomy
   /
3227
radio emission from the remnants of the supernovae of and  measurements
at are compared with previous radio and optical observations see
of
   /
3228
the cosmic radiation and solar terrestrial relationships  paper presented
at the assembly of the union geodesique et geophysique internationale
rome september reviewing the properties of cosmic radiation and
its association with solar and geophysical processes and including
a description of experimental methods developed to study low energy
cosmic ray particles
   /
3229
the incidence of meteor particles upon the earth  radio echo rates
for both shower and sporadic meteors measured at adelaide with cw
equipment are applied to the calculation of the incident flux above
limiting brightnesses in the region of  dependence of ionizing probability
on velocity is discussed and the fluxes and densities agree reasonably
well with independent evaluations from visual meteor rates
   /
3230
a prediction of a meteor orbital period  the probable orbital period
of a meteor shower observed on is predicted from examination of
snowfall records in japan assuming the suggested correlation between
precipitation and occurrence of meteor showers to be real
   /
3231
analysis of the sinusoidal variation of magnetic declination of april
and  analysis of magnetograms of european stations suggests the development
of a counter clockwise vortex like perturbation in the ionosphere
bordering on the southern limits of the auroral zone and lasting
less than
   /
3232
radar in the rain  an outline of radar investigations into cloud
structure
   /
3233
radiosonde trials at payerne  report of trials in switzerland in
may and june in which types of radiosonde from various countries
were compared
   /
3234
investigation of the upper layers of the atmosphere  measurements
of composition pressure density and temperature up to a height of
miles were made by means of containers which collected samples of
air after being automatically released from rockets  experimental
data are tabulated and some results obtained in the usa and ussr
compared  references
   /
3235
ionospheric drifts at brisbane  measurements over a year period show
that speeds are less than those observed at higher altitudes  the
e region and solar harmonics show large seasonal phase changes in
the northward component the phase for the northward component in
summer is in fair agreement with higher latitudes  the f region harmonic
seasonal change is greater in the eastward than in the northward
component
   /
3236
measurement of ionospheric winds  experiments made at domont france
by the three receiver method are described  the electron displacements
deduced from observations correspond to some extent with those necessary
to account for the daily variations in the earths magnetic field
   /
3237
some possible relations between the nightglow and the ionosphere
ionospheric data from stanford california are compared with nightglow
data from cactus peak california  the nocturnal variation of the
brightness of the green line of is found to be similar to the variation
of height of thd f region  the nocturnal variation of the brightness
of the red lines of is found to be similar to that of the electron
density of the f region  the possibility that the red lines are produced
by radiation following dissociative recombination of electrons with
o ions is discussed  paper presented at the assembly of the union
geodesique et geophysique internationale rome september
   /
3238
the reflection coefficient of ionospheric layers  experiments made
at and show that the reflection coefficient which is nearly unity
for the f layer falls to a very low value for the e layer and that
loss of energy due to reflection from the latter is of the same order
as the nondeviative absorption
   /
3239
the scattering of radio waves of very high frequency in the ionosphere
   /
3240
radar echoes from inter stroke processes in lightning  radar echoes
at were used to investigate interstroke lightning processes  the
most intense activity of junction streamers is between heights of
these junction streamers may sometimes grow in height up to although
their activity decreases with height the lowest level at which they
occur remains constant throughout flashes and their horizontal extent
is about to km  echoes from these junctions always decrease before
the onset of a flash
   /
3241
theory of the auroral spectrum  paper presented at the assembly of
the union geodesique et geophysique internationale rome september
the main luminescence observed is due to inelastic collisions made
by the incident particles and by the ejected electrons degradation
of the ultraviolet radiation emitted and scattering of solar radiation
thermal processes such as dissociative recombination
   /
3242
the work of soviet scientists on the luminescence of the night sky
and aurorae  a review of the research carried out in the last years
with particular reference to the igy in a network of stations all
over the ussr references
   /
3243
a method for interpreting the dispersion curves of whistlers  an
analytical solution to the problem of determining the dispersion
of a whistler from a known electron density in the outer atmosphere
is formulated  the results are then applied to the inverse problem
of deducing the variation in electron density from the dispersion
curve  a numerical example is given
   /
3244
calibration of narrow sector radiogoniometers for atmospherics
   /
3245
the balanced transistor dc convertor  a theoretical analysis of operation
is given
   /
3246
current capacitance characteristics of metal rectifiers  report of
measurements and discussion of the reverse current voltage and capacitance
voltage characteristics of metal rectifiers at room and liquid
air temperatures
   /
3247
silicon rectifiers  the characteristics are given of an experimental
rectifier unit rated at and peak inverse voltage  it is hermetically
sealed in a metal case of mm diameter
   /
3248
the influence of the copper raw material on the properties of copper
oxide rectifiers  the characteristics of rectifiers were investigated
as a function of manufacturing conditions and degree of purity of
the copper used  results are tabulated and show that rectifier characteristics
are considerably affected by the oxygen content of the copper
   /
3249
logical design of a computer for business use  paper presented at
the convention on electronics in automation cambridge england june
describing an emi serial machine operating at a clock rate of with
magnetic drum storage
   /
3250
torsional waves in wires disk loading increases computer memory
note on the characteristics of a disk loaded delay line machined
from a solid brass rod
   /
3251
digital analogue converter provides storage  a transistorized converter
changes eight binary bits received in parallel from a shift register
to steps in amplitude of a sine wave  one binary bit is used to obtain
phase information  operation  operation is performed within a sampling
period occurring at an average rate of
   /
3252
analogue and digital computers in nuclear engineering  a group of
articles outlining the principles of operation and giving a survey
of application in the usa
   /
3253
ada a transistor decimal digital differential analyser  circuit techniques
and assembly and construction methods are discussed  the specification
of the machine is summarized and some typical problems are considered
   /
3254
signals from switched ferroelectric memory capacitors
   /
3255
electric nonlinear computation performed by linear elements
   /
3256
application of junction transistors to carrier frequency computing
amplifiers  a discussion of the properties required by a transistorized
summing amplifier in a carrier frequency analogue computer  details
are given of a practical amplifier using standard commercial transistors
   /
3257
moulding moves in on printed circuits  the moulding process described
permits the use of heavy gauge conductor material in circuits of
high current carrying capacity
   /
3258
an automatic gain control system for microwaves
   /
3259
wide band balun transformer  description of a balun transformer developed
for use with a cro deflection amplifier  bandwidth extends from
below to above  input impedance data and pulse response characteristics
are shown  one balun coil can be used alone as a passive wide band
pulse inverter
   /
3260
design of wide band rf transformers utilizing a synthesized equivalent
network
   /
3261
signals from switched ferroelectric memory capacitors  the equivalent
circuit for a bistable storage capacitor is a current generator with
a resistance in parallel  the properties of the output signals from
switched and unswitched stores are discussed using this model
   /
3262
high speed microwave switching of semiconductors  a microwave switch
using an n type ge diode has been shown to give pulse rise and decay
times as low as
   /
3263
transistor nor circuit design  a nor circuit gives a signal output
only when no input signal is present in  examination of transistor
characteristics gives a stable design for an arbitrary number of
inputs and outputs on a single type transistor  crosstalk factor
and speed of operation are considered
   /
3264
a new family of transistor switching circuits  two pairs of output
levels are obtained from the dual range circuits described which
incorporate both npn and pnp transistors  the possibility of lower
stand by power dissipation and greater switching speed than the dctl
circuits see of is offered
   /
3265
transistor terminal switches  discussion showing how the blocking
voltage concept may be applied to obtain negative resistance characteristics
using a junction transistor a point contact transistor a modified
double base diode or a modified tetrode  a few applications mainly
in telephone systems are indicated
   /
3266
a note on noise temperature  expressions are given for the effective
noise temperature of a lossy passive network with internal noise
sources  their application in different receiving systems is discussed
   /
3267
recent advances in finline circuits
   /
3268
equivalent admittance impedance and scattering matrices
   /
3269
electric nonlinear computation performed by linear elements  simple
linear circuits are shown for performing multiplication division
and inversion and forming powers positive and negative roots logarithms
antilogarithms and hyperbolic functions
   /
3270
interpretation of network theorems in terms of laplace transforms
   /
3271
greater selectivity with the cw clipper filter  a two stage amplifier
with variable bandwidth
   /
3272
charts simplify passive lc filter design  universal design data permit
design of butterworth and tchebycheff filters of prescribed steady
state insertion loss characteristics  design of band pass prototypes
of lumped element configuration is given
   /
3273
a travelling wave directional filter
   /
3274
design and manufacture of practical filter circuits  discusses the
effects of distributed capacitance component proximity encapsulating
material and impedance mismatch
   /
3275
travelling wave tube limiters
   /
3276
a phasor method of nonlinear network analysis  the network is represented
by the sum of a finite number of simple sinusoidal functions with
time chosen from a knowledge of the network experiment and preliminary
analysis  an appendix illustrates stability tests and an application
of the method to a typical problem
   /
3277
fine structure of response curves of frequency entrained oscillations
jump and hysteresis phenomena suggested by cartwright see of together
with a dependence of entrainment range on forcing amplitude have
been observed in an electromechanical analogue of a forced self excited
system
   /
3278
a low frequency random signal generator  the and noise components
each in an overall bandwidth of are selected from the noise output
of an argon filled thyratron operating in a magnetic field  after
peak rectification the resulting noise signals are added so that
their dc components cancel  the amplitude distribution of the resultant
output then approximates very closely to a gaussian distribution
the output noise spectrum is flat from zero frequency up to  a full
circuit diagram is given
   /
3279
measurements of the quality of very low frequency rc oscillators
a figure of merit is calculated for a number of different rc networks
and the experimental determination of this coefficient is described
   /
3280
double excitation in decimetre wave oscillators with coaxial lines
the simultaneous oscillation at a frequency corresponding to a setting
of about in a disk seal triode oscillator tuned to is investigated
and the calculations are verified by experiment
   /
3281
monovibrator has fast recovery time  use of complementary transistors
decreases recovery time of monostable multivibrator  this prevents
erratic operation when circuit is used in a television sync generator
since both transistors are off during timing cycle circuit is relatively
insensitive to transistor variations and operates reliably from to
for input frequencies from to
   /
3282
a simple rectangular pulse generator  the cathode coupled multivibrator
circuit discussed produces pulses of up to amplitude with rise times
from to
   /
3283
method of obtaining integral mark space ratios of high accuracy with
a continuously variable control frequency  a pulse generator circuit
is described in which the mark space ratio can be adjusted to within
over the range to for control frequencies from to
   /
3284
increasing quartz oscillator stability  brief description of a quartz
servo oscillator forming part of frequency standard equipment type
a frequency error of less than in occurs for a change in supply voltage
or change in temperature
   /
3285
fast gray wedge analyser for high input rates  a full description
is given of the circuits and operation of a pulse height analyser
designed for positive input pulses at rates up to with less than
distortion of the spectrum  the resolution is approximately
   /
3286
pulse compression part  description of an experimental realization
of the method discussed in of january
   /
3287
the time behaviour of logarithmic amplifier input circuits  the nonlinear
nature of the logarithmic amplifier input circuit causes the time
constant to vary with current and three definitions of effective
time constant are examined based on an analysis of the time behaviour
of the input circuit to a step change of input current
   /
3288
new types of dc amplifier  the cascade balance system  owen prinz
method of zero drift correction is applied to the first of two identical
amplifier stages the residual drift is then balanced against that
of the second stage  the overall drift is reduced times as compared
with the parallel balance system  a practical design is fully discussed
   /
3289
new types of dc amplifier the reflex monitor system  a correcting
amplifier or monitor identical to the input stage of the main amplifier
corrects alternately its own drift and that of the main amplifier
a differential input is used which rejects in phase drift components
and residual drifts are balanced between the two amplifiers  full
details are given of a practical circuit which has certain advantages
over the simpler cascade balance system described in part above
   /
3290
push pull amplifier design  a method of designing class ab push pull
amplifiers which eliminates the need to plot composite characteristics
is discussed and some examples are given which compare favourably
with practical results
   /
3291
total differential feedback  a device for squaring the effective
possible feedback in a feedback amplifier
   /
3292
the simple reactor circuit its operation and mode transition
   /
3293
the series magnetic amplifier  a theoretical analysis is given of
the steady state operation of the amplifier for saturation states
of the cores  the control circuit impedance and control voltage relations
determining the mode of operation are established and the gain
characteristic and time constant are considered
   /
3294
analysis of the full wave magnetic amplifier circuits considering
the change of the width of the dynamic hysteresis loop
   /
3295
the operation of the current type self balancing magnetic amplifier
a theoretical analysis giving the voltage gain and time constant
in terms of the circuit parameters  within the range of ideal components
the input impedance is zero
   /
3296
high frequency amplification using junction transistors  the maximum
possible stage gain of a unilateralized grounded emitter narrow band
amplifier stage is calculated and the design of interstage coupling
transformers is described  a typical if amplifier stage is designed
and its stability factor calculated
   /
3297
an analysis of transient response of junction transistor amplifiers
an exact solution of the one dimensional diffusion equation is obtained
by the method of laplaces transform  the short circuited output collector
current is calculated for a step input forcing function  experimental
results agree with the theory and for ordinary conditions the physical
process underlying transistor transistor action must be diffusion
of minority carriers across the base region
   /
3298
how transistors operate under atomic radiation  results of tests
on an amplifier detector system show that degrading effects of irradiation
can be controlled to some degree by negative feedback  measurements
were also made on a single separate transistor and a coaxial cable
   /
3299
internal noise of transistor amplifiers  the internal noise levels
of two commercial transistor amplifiers were measured for various
input impedances and the results are shown graphically
   /
3300
transistors in speech equipment  the use of transistors in af circuits
is described and constructional details are given of a speech amplifier
   /
3301
theory of the ferromagnetic microwave amplifier  all three possible
types of operation using respectively two electromagnetic cavity
modes two sample modes and one sample and one cavity mode are discussed
one especially simple case that of a sphere in the first type of
operation is treated separately  thereafter all three cases are discussed
in terms of scalar and vector potentials  an appendix deals with
the gain bandwidth problem and gives an expression for the equivalent
negative q of the sample
   /
3302
twin cavity for nh masers  a system of two coupled cavities is described
replacing the single cavity of an nh maser  using this system the
curve of the oscillation frequency against cavity temperature presents
a plateau thus reducing considerably the pulling effects of the cavity
   /
3303
maser noise considerations  a discussion of the effect of the saturation
rf field on the noise figure of a three level maser  for the conditions
considered the effect is small  the spontaneous emission equivalent
temperature for a free electron vacuum tube amplifier is one half
that of a maser  in principle more general quantum mechanical amplifiers
can be constructed which will not have spontaneous emission noise
   /
3304
compact microwave single sideband modulator using ferrites  see also
of
   /
3305
foster seeley discriminator  a detailed analysis is given of the
circuit and the use of the design formulae is illustrated  with the
circuit arrangement described a sensitivity of af signal per can
be obtained with less than second harmonic distortion at modulation
   /
3306
statistical properties of an isotropic random surface
   /
3307
possibility of luminescent quantum yields greater than unity  it
is shown that an excited sensitizer can transfer its energy simultaneously
to two activators under suitable conditions leading to two emitted
photons per incident higher energy photon  the probability of this
transfer process is computed and the process is shown to be experimentally
feasible
   /
3308
physics and the new electronics  vacuum electronics and the new crystalline
solid electronics are compared  a brief account of recent work
on semiconductors and maser amplifiers is given and the effect of
these new developments on the training of electronic engineers is
discussed
   /
3309
some remarks about electron correlation  a comparison is made between
theories representing different approaches to the inclusion of correlation
in the wave mechanics treatment of a free electron gas
   /
3310
correlation energy of an electron gas at high density plasma oscillations
an analysis of the contribution made by zero point oscillations
to the correlation energy of an electron gas at high density  this
contribution is expressed in terms of that from the scattering states
by using the analytic properties of the scattering amplitudes  the
results are compared with those of bohm pines of
   /
3311
correlation energy of a high density gas plasma coordinates  the
model hamiltonian of sawada which describes electron correlation
at high density is examined  it is shown that the set of scattering
modes for momentum transfers below a certain is not complete  it
is completed by the plasma mode  is the natural debye length of the
theory
   /
3312
characteristic energy loss of electrons passing through metal foils
momentum exciton model of plasma oscillations  previous work is extended
to obtain a unified theory of collective and individual electron
effects in the excitation of a degenerate electron gas by fast incident
electrons the theory is equivalent to the screening out by the incident
electrons
   /
3313
quantum theory of electrical transport phenomena  using a simple
model a technique is developed which gives the entire density matrix
of the system of charge carriers in the steady state  the model consists
of noninteracting free or bloch electrons scattered by random rigid
impurity centres  the density matrix is developed in ascending powers
of the strength of the scattering potential  the boltzmann transport
equation represents an approximation valid in the limiting cases
of very weak or very dilute scatterers  higher order corrections
are given
   /
3314
the specific heat of the electrons of metals  a new approximation
method is used to calculate the specific heat for low temperatures
taking account of electron interaction  results are compared with
those obtained by other methods
   /
3315
exact nonlinear plasma oscillations  a solution is given for the
problem of a one dimensional stationary nonlinear electrostatic wave
in a plasma free from inter particle collisions  in the limiting
case of small amplitude waves the linearized theory can still be
applied by using singular first order distribution functions
   /
3316
contribution to the diffusion oscillations in gas discharge plasma
   /
3317
quenching of the negative glow by microwaves in cold cathode gaseous
discharges  a discussion of results obtained in he at a pressure
of mm hg using pulse at  enhanced emission was observed in ne a and
xe discharges at mm hg
   /
3318
the theory of the surface effect of secondary emission  for primary
energies of about of the secondary electron yield in light metals
can be ascribed to surface effects  for higher energies and heavier
metals surface effects can be neglected
   /
3319
effective electron electron and electron ion cross sections in plasmas
cross sections for elastic scattering are infinite for strictly coulomb
interaction but finite values are found by using debyes theory of
electrolytes
   /
3320
report on the course of the international school of physics of the
italian physical society varenna july august  report of the proceedings
of the course on magnetic properties held at the villa monastero
varenna  the text is given of lectures and communications including
the following  paramagnetism in crystals  magnetic properties of
metals  paramagnetic relaxation  ferromagnetism  metamagnetics or
critical field antiferromagnetic materials  nuclear magnetism and
nuclear relaxation  line breadths and the theory of magnetism  the
influence of electrons on nuclear spin resonance in diamagnetic materials
chemical displacement and indirect interaction  stochastic theory
of magnetic resonance  the concept of temperature in magnetism  magnetism
at very low temperatures and nuclear orientation  cyclotron resonance
in crystals  optical methods for radio frequency resonance  magnetic
properties of super conductors  hall effect in ferromagnetics  critical
scattering of neutrons from ferromagnets  the van vleck model of
ferromagnetism  influence of the apparatus on nuclear magnetic resonance
paramagnetic resonance of impurities in a semiconductor  the electric
analogue to antiferromagnetism antiferroelectricity  magnetic susceptibility
of electrons in periodic fields
   /
3321
equivalence theorems for electromagnetic fields  theorems are considered
with reference to electric and magnetic surface currents
   /
3322
forces and stresses in an electromagnetic field  the theories of
faraday larmor and livens and the energy method are compared and
applied to some illustrative examples  the three theories may lead
to different results for nonrigid magnetic materials and the larmor
and livens theory may not be applicable to magnetostriction  a discussion
by r  m  lichtenstein giving a further thermodynamic method is
included
   /
3323
coils for the production of high intensity pulsed magnetic fields
the design performance and applications of a pulsed field system
for are described  it consists of a capacitor bank charged to which
is discharged through a be cu helix of in  internal diameter and
long  detailed design data are also given for a range of coils giving
increased volume and field uniformity at lower field intensities
and include a coil providing transverse access to the field
   /
3324
production and use of high transient magnetic fields par  the mechanical
and thermal limitations of solid metal coils are discussed and illustrated
by experiment  these limitations can be removed by force free
coil designs  part of
   /
3325
variable and reversible magnetic fields obtained from a permanent
magnet  a permanent magnet forms the core of a cylinder whose surface
is made of two armco iron shoes and two brass shoes  rotation of
the cylinder directs the flux either to a shunt or across the gap
of the magnet for deflection of an atomic beam
   /
3326
oscillations of electron cloud in external fields  the density fluctuations
are analysed in a pure electron gas not neutralized by positive
ions and under the influence of an external magnetic field
   /
3327
a semi infinite array of parallel metallic plates of finite thickness
for microwave systems
   /
3328
on the line width in ferromagnetic resonance  it is suggested that
the line width is modified by a nonuniformity of the demagnetization
field throughout the specimen  it is shown that the broadening is
greater for a disk magnetized normal to its plane than for one magnetized
in its plane and also that the effect would be greater for ferrites
than metals both results are in agreement with experiment
   /
3329
theory of the ferromagnetic microwave amplifier
   /
3330
high temperature molecular beam microwave spectrometer  a description
of measurements at on the rotational transition of kcl
   /
3331
effective magnetic anisotropy and magnetostriction of monocrystals
a nine constant expression is derived which describes empirically
the spontaneous magnetostriction to the sixth order in the direction
cosines of the magnetization  the relation between the effective
anisotropy in domains and domain walls is also studied
   /
3332
diffusion of charged particles in a homogeneous electromagnetic field
an approximate solution is considered
   /
3333
the elastic impurity centre model  an approximation between two extraneous
atoms in a crystal lattice
   /
3334
radio astronomy  the main part of this issue is devoted to a group
of papers dealing with practical and theoretical aspects of radio
astronomy  abstracts of some of the papers are given individually
titles of others are as follows  introduction to radio astronomy
the discovery and identification by karl guthe jansky of electromagnetic
radiation of extraterrestrial origin in the radio spectrum  early
radio astronomy at wheaton illinois  the telescope program for the
national radio astronomy observatory at green bank west virginia
noise levels at the national radio astronomy observatory  radio astronomy
at the meudon observatory  a high resolution radio telescope for
use at  the sydney radio telescope  measurements of solar radiation
and atmospheric attenuation at millimetres wavelength  scanning the
sun with a highly directional array  a wide band antenna system for
solar noise studies  the radio spectrum of solar activity  a swept
frequency interferometer for the study of high intensity solar radiation
at metre wavelengths  the cornell radio polarimeter  a time sharing
polarimeter at a polarimeter in the microwave region  radio sources
and the milky way at  flux measurements of cassiopeia a and cygnus
a between and it  the distribution of cosmic radiation background
radiation  a galactic model for production of cosmic and radio noise
hydrogen line study of stellar associations and clusters  extragalactic
line studies  measurements of planetary radiation at centimetre wavelengths
planetary and solar radio emission at metres wavelength  radio
emission from comet on  lunar thermal radiation at  lunar radio echoes
radar echoes from the moon at a wavelength of cm  a phase tracking
interferometer  radio astronomy measurements at vhf and microwaves
cosmical electrodynamics
   /
3335
spectral lines in radio astronomy  a review of atomic and molecular
resonance lines occurring in the radio spectrum  it is shown how
radiation from the galaxy is modified by interstellar gas
   /
3336
radio astronomy polarization measurements  a survey of possible techniques
for measuring polarization and for studying the faraday effect
shows which components should be measured  methods for deducing the
electron density along the path are discussed and applied to data
on radiation from the sun and the crab nebula
   /
3337
absorption techniques as a tool for cm research  absorption lines
in the spectra of radio stars are used to study the distribution
of interstellar gas minimum distances to radio stars and problems
related to cosmology
   /
3338
excitation of the hydrogen line  the influences of certain mechanisms
on the spin temperature such as electron collision and interaction
with light are considered and their importance to radio observations
is discussed  the deuterium line at is also considered
   /
3339
restoration in the presence of errors  a discussion of the relationship
between observed aerial temperatures and the true distribution of
a celestial source  techniques for allowing for certain errors are
described
   /
3340
a broad band microwave source comparison radiometer for advanced
research in radio astronomy
   /
3341
a method of calibrating centimetric radiometers using a standard
noise source
   /
3342
a radio telescope
   /
3343
an antenna array for studies in meteor and radio astronomy at metres
   /
3344
radio telescope antennas of large aperture
   /
3345
mark minitrack base line components
   /
3346
the large scale structure of the galaxy  observations at are being
made at sydney australia using an aerial of diameter and beam width
and a receiver with bandwidth of  a composite diagram of the galaxy
is shown based on these observations and similar observations at
leyden netherlands
   /
3347
radio observations of the comet arend roland  observations made at
cambridge between march and may at and using different instruments
gave negative results  emission at and has previously been reported
elsewhere
   /
3348
duration of transients in solar radio noise  histograms of observations
made at oslo are given  rebers theory see of is confirmed for this
frequency see also of february  please note change of number
   /
3349
frequency drift of short time transients in solar radio noise  an
analysis of records made at oslo on a two channel receiver is being
made to give a detailed study of solar noise storm bursts  channels
are centred on and bandwidth is time constant and noise factor about
it is suggested that the transients in most cases have a frequency
drift in either direction ranging from about to higher values
   /
3350
discussion of solar radio flux measurements and an estimation of
the accuracy of observations  revision of previously published data
is recommended
   /
3351
critical frequency refractive index and cone of escape in the solar
corona  nomograms give refractive index governing radio propagation
in the solar corona and the semivertical angle of the cone of escape
   /
3352
studies at the mc math hulbert observatory of radio frequency radiation
at the time of solar flares  records of radiation at and during several
hundred flares are compared with associated data obtained from spectroheliograms
   /
3353
a dynamic spectrum analyzer for solar studies  the range is swept
three times a second in three overlapping bands  results appear as
a frequency intensity display on film
   /
3354
radio interferometry of discrete sources  salient features of the
theory and practice of radio interferometry are presented with special
attention to assumptions and to the specifically two dimensional
aspects of the subject  a theorem is proved according to which only
certain discrete stations on a rectangular lattice need be occupied
for full determination of a discrete source distribution  procedures
in interferometry are discussed in the light of this result and an
optimum procedure is deduced  current practice is considered over
conservative eg independent data in the case of the sun are obtainable
only at station spacings of about wavelengths on the ground a fact
which has not hitherto been taken into account
   /
3355
preliminary report of geomagnetic observations at prince harald coast
antarctica  the results of geomagnetic observations during the first
japanese antarctic research expedition are briefly summarized  the
geomagnetic total intensity was found to be less than the value in
vestines world map  correlations between geomagnetic and ionospheric
phenomena are discussed
   /
3356
apsidal motion of an igy satellite orbit  an error in previous work
is corrected concerning the movement of the line of apsides relative
to a node  please note change of udc number
   /
3357
winds and temperatures between a review  the results of measurements
by various methods of temperature and wind velocity in the northern
hemisphere and briefly outlined  the results are used to obtain consistent
systems of zonal wind and temperature for the winter and summer
seasons  a standard atmosphere is suggested for northern latitudes
to a height of km extended to km for latitudes to for both seasons
   /
3358
the use of radio stairs to study irregular refraction of radio waves
in the ionosphere  information from various sources on the amplitude
and phase scintillation of radio star radiation is reviewed and the
experimental data compared with theory  there is general agreement
on most but not all of the characteristics of the scintillation and
its variation with time and zenith angle  the rate of scintillation
increases under magnetically disturbed conditions  there is good
correlation with spread f ionospheric reflections and some with sporadic
e reflections  the scale of the irregularities causing the scintillation
is of the order of a kilometre  the most puzzling problem is the
cause of the night time maximum in scintillation  references
   /
3359
some measurements of high latitude ionospheric a theory of absorption
and a technique of measurement are described  observations at have
shown that marked differences can occur in disturbed periods between
stations km apart  most of the absorption occurs below the e region
and it correlates well with the geomagnetic k index
   /
3360
ionosphere review  sunspot activity has reached unprecedented high
values average f layer critical frequencies have increased by a factor
of just over two since monthly mean values for noon and midnight
were considerably higher that at last sunspot maximum  muf as high
as have been reported and examples of long distance reception at
and are noted  though sunspot maximum may have occurred before the
end of little change in propagation conditions is expected over various
paths in as compared with those during similar months of  quasi maximum
conditions may well prevail throughout and
   /
3361
transistor relays have low idling current  two transistor circuits
for remote control are shown which operate a or electromechanical
relay from the output signal of a receiver  this may be a carrier
modulated at or a pulsed microwave signal  using si transistors the
idling current is a few microamps
   /
3362
magnetic regulation transistor power supply  the method uses saturable
reactors in the input and load circuit of the supply  for close regulation
a silicon diode reference voltage may be used
   /
3363
compact supplies have wide range regulation  use of solid state rectifiers
and high current regulator tubes eliminates power transformer
and reduces size and cost of power supplies  units have regulation
better than ripple of and stacking factor of about capacity per inch
of rack space
   /
3364
a method of designing small power transformers for communication
equipment
   /
3365
the effect of capacitance on power supply filter bounce  a discussion
on the design of power supply filters
   /
3366
regulated supply for transistor amplifiers
   /
3367
semiconductor rectifiers  summary of characteristics and review of
industrial applications of si ge se and copper oxide rectifiers
   /
3368
a new coltage divider circuit for semiconductor rectifiers  auxiliary
transformers divide the inverse voltage across high power rectifiers
   /
3369
the fused silicon rectifier  a comprehensive review dealing with
rectification theory basic fabrication techniques and the properties
of si the counter electrode alloy solder the base solder and the
base electrode encapsulation and heat dissipation theoretical and
experimental properties of si rectifiers
   /
3370
rating and application of germanium and silicon rectifiers  a discussion
of the factors limiting the life and rating of semiconductor rectifiers
practical design criteria are considered including fusing surge voltage
protection and parallel and series operation
   /
3371
direct water cooled germanium power rectifier  a description of the
development performance and operation of various types of water cooled
unit
   /
3372
a unique approach to computer versatility  the need for a computer
which can perform specialized computations as well as general data
processing is met by the integration of a general purpose computer
with a digital differential analyzer  the design involves shared
storage system and special input output facilities
   /
3373
description of a large electronic computer  description of the ibm
type computer which comprises storage units of magnetic tape core
and drum type
   /
3374
cycle and delay time considerations in a real time digital computer
considerable improvement in a computer program can be obtained by
careful selection of cycle and delay times  the criterion of information
handling efficiency provides a basis for comparing the quality of
various programs
   /
3375
recording and read out circuits for binary numbers in a magnetic
drum storage system  details of the storage system used in the computer
type at the milan polytechnic  see also of
   /
3376
a swiss analogue computer  an electromechanical system is described
in which quantities are represented by ac voltage amplitudes and
by the angle of rotation of shafts in a servo system
   /
3377
trapped flux superconducting memory  a memory cell based on trapped
flux in superconductors has been built and tested  the cell is constructed
entirely by vacuum evaporation of thin films and can be selected
by coincident current or by other techniques with drive current requirements
less than  the short transition time of the trapped flux cell
indicates its possible use in high speed memories  the superconductive
film memory does not exhibit the problems of delta noise in core
memories resulting from the difference in half select pulse outputs
   /
3378
an analysis of a persistent super current memory cell  a theoretical
model of a storage cell based on thin films of superconductors is
discussed  an experimental device built to resemble the model was
found to have the predicted behaviour
   /
3379
a binary weighted current decoder  a method for driving cr rubes
from digital equipment is described in which the deflection yoke
is fed directly from binary weighted constant current sources  design
considerations are outlined and a comparison is made with other methods
   /
3380
radio interference control as applied to business machines
   /
3381
negative impedances transistors and feedback circuits and their interrelations
the use of transistors in negative impedance feedback circuits
is investigated and the influence of transistor characteristics on
the network parameters is determined theoretically and by measurement
some practical difficulties are discussed
   /
3382
mechanics of electronics  some suggestions for layout and mechanical
design of equipment
   /
3383
the influence of the coefficients of the transfer function of a transmission
system on the output characteristics as a function of time
the input considered is in the form of a step function
   /
3384
on the use of ferrites in wide band hf transformers  design problems
encountered using ferrite cores in hf power transformers are discussed
including methods of heat dissipation  characteristics of two commercially
available designs are given
   /
3385
electronic switch doubles as cathode follower  basic two way electronic
switch may be expanded to multiway unit by adding input selector
circuits or may be used as a precision cathode follower by eliminating
the selector  circuit has near infinite input impedance and near
zero output impedance  comparator compensation permits accuracy of
over
   /
3386
an electronic transmitter receiver antenna switch description of
a twin triode circuit for instantaneous break in operation
   /
3387
miniaturized tantalum solid electrolytic capacitors  the replacement
of an aqueous electrolyte by an oxide film results in an improvement
in the low temperature characteristics and an extension of the frequency
range  these capacitors also have the advantage of storing more charge
per unit volume than previous types
   /
3388
theory of electrical networks with nonlinear elements  mathematical
treatment making use of almost periodic functions
   /
3389
the occurrence of abnormal states in certain ferroresonant circuits
two identical parallel resonance circuits incorporating coils with
iron cores are connected in series  conditions are examined under
which an applied alternating voltage is not equally distributed between
the circuits  see also of
   /
3390
the problem of increasing the frequency stability of crystal oscillators
by means of compensation  herzogs method of improving the pierce
oscillator by including a compensating resistance is investigated
the dependence of the oscillator frequency on the circuit parameters
with or without compensation is calculated  the advantages of compensation
are offset by serious drawbacks especially in crystal clock applications
   /
3391
the calculation of linear circuits  circuit components which may
include valves transistors and transformers are set up in the form
of a multipole admittance matrix from this five determinants are
obtained
   /
3392
theory of networks of linearly variable resistances  a network of
fixed resistances and linear rheostats driven by a common shaft can
replace nonlinear elements  such networks are amendable to good design
techniques and can be described in a mathematical form analogous
to that of fixed rl networks
   /
3393
theoretical and experimental investigation of distortion in low frequency
junction transistor quadripoles  expressions are derived for calculating
distortion by differentiating the quasilinear hybrid parameters
of the quadripole  methods are described of measuring distortion
in junction transistor quadripoles in earthed base earthed emitter
and earthed collector circuits  calculated and measured results are
compared for the earthed emitter circuits close agreement is found
the application of the results of the investigation to the design
of transistor amplifiers is discussed  see also of
   /
3394
high frequency crystal filter design techniques and applications
commercially available hf crystal filters exhibit performance characteristics
previously attainable only at lower frequencies  filters normally
consist of from two to eight quartz resonators in a lattice or bridge
network and are characterized by high q and stability under extreme
environmental conditions  normal values of q for filter components
in the range are from to in certain filters element qs exceed by
eliminating the need for multiple frequency conversions the small
rugged filters are useful in many am ssb and fm receivers as well
as single sideband generators
   /
3395
low pass filters for mobile use  constructional details are given
of simple compact filters for the suppression of radiation at television
frequencies from mobile transmitters operating at frequencies below
and in the range
   /
3396
transmission line low pass filters  the networks consist of sections
of line with suitably constructed lumped shunt capacitance  design
curves are given and practical models are illustrated
   /
3397
design of three resonator dissipative band pass filters having minimum
insertion loss  comment on of and authors reply
   /
3398
band pass filter design technique  universal curves provide design
information for butterworth and tchebycheff stagger tuned filter
networks for band pass amplifiers  required number of stages centre
frequency cut off frequencies and stage gain requirements can be
determined
   /
3399
galvanomagnetic oscillators  the type of hall effect oscillator described
has an efficiency of
   /
3400
an ultrastable keyed vfo  high stability is achieved by constructing
the variable tuned circuit which has a high q and is of rigid construction
as a single unit separate from the remainder of the oscillator
clickless keying is obtained by a relatively small change in screen
grid potential
   /
3401
self oscillatory systems with two degrees of freedom at multiple
frequencies  mathematical analysis of the operation of an oscillator
using two coupled tuned circuits resonating at frequencies one of
which is an approximate multiple of the other  expressions are derived
for the oscillator frequencies and their instability as a function
of the instability of the tuned circuits and the supply voltages
   /
3402
idealized treatment of relaxation oscillator circuits  topological
analysis of idealized circuits with the introduction of critical
point notation  a correct solution can only be obtained if the system
oscillates
   /
3403
transistor oscillator supplies stable signal  colpitts circuit employing
one germanium transistor and one zener diode operates from a laboratory
regulated power supply to maintain a sine wave voltage of precise
amplitude
   /
3404
determination of the frequency of a transistor multivibrator between
and to  experimental and theoretical results supplement those of
mc duffie of for the pulse duration and repetition rate of astable
transistor multivibrator circuit
   /
3405
pulse height selector with constant analysis time  a single channel
pulse height selector with a analysis time constant to within independent
of the pulse height is described
   /
3406
unusual transistor circuits  the main features of design and a physical
explanation of the action are given for voltage catching transistor
pump emitter squared follower and transistor gating circuits
   /
3407
millimicrosecond pulses in the millimetre wave region  a technique
is described for the generation amplification and detection of pulses
in the mm region  the pulses are wide at the base with a peak power
of a few milliwatts
   /
3408
forty megacycle scaler  the scaler has a scale of eight and uses
a fast flip flop as a basic element  the latter can be triggered
at a rate higher than and has a double pulse resolution of
   /
3409
decade decimal counter speeds printed read out  high speed circuit
uses magnetron beam switching tubes to sample store and provide multi
output functions without stopping the original count or losing input
information during read out
   /
3410
amplifier low frequency compensation  general expressions are deduced
for the indicial response ie response to unit step input and gain
frequency and phase frequency response leading to conditions for
maximal flatness  compensation is then considered together with the
effects of negative feedback  multistage amplifiers are also discussed
   /
3411
pulse method for the amplification of af oscillations  the advantages
and efficiency of a pwm method are discussed
   /
3412
dynamic range of negative feed back pulse amplifiers  analysis of
the limiting conditions for grid current in two or three stage amplifiers
   /
3413
more transformerless amplifiers  a review of recent work published
since an earlier article of  single input series connected and petersen
sinclair output stages of are discussed
   /
3414
practical circuits of video amplifiers using junction transistors
practical circuits with two two types of russian transistor are described
complex feedback is used in order to reduce the distortion of
the leading edges of the pulses
   /
3415
noise temperature measurement on a solid state maser  noise measurements
have been made on a three level maser operating at with sufficient
accuracy to establish that its noise temperature does not exceed
it
   /
3416
a parametric electron beam amplifier
   /
3417
the optimum design of a tunable multiplier for frequency modulated
oscillations  the design of tunable frequency multipliers containing
simple one or two stage filters in the individual multiplier stages
is investigated  adjacent channel attenuation and distortion can
be achieved if the multiplication per stage does not exceed  the
fundamental frequency should not be less than about
   /
3418
combined limiter and discriminator  the limiter incorporates a harmonic
rejector in series with the diode  distortion less than of any harmonic
is easily obtained and stray capacitances are small leading to high
sensitivity and output
   /
3419
pulse detector with an inductance capacitance filter  an ideal detector
with an lcr filter is considered taking into account the internal
impedance of the current source  a method is proposed for calculating
the voltage at the load when detecting pulses of arbitrary shape
and the necessary formulae are derived
   /
3420
the ether and the special theory of relativity  an ether which is
immobile in its immediate surroundings but capable of a movement
of translation is suggested  it is hoped that this hypothesis will
provide a physical explanation of electrodynamic and other phenomena
and will not be inconsistent with the results of the special theory
of relativity
   /
3421
polarimetry in the infrared
   /
3422
connection between electron temperature determination by means of
the langmuir probe method and the two probe method
   /
3423
the lamb shift  an elementary account of present day knowledge concerning
the electron and a discussion of lamb and rutherfords experiment
see egin relation to the anomalous magnetic moment of the electron
   /
3424
use of complex conductivity in the representation of dielectric phenomena
a representation for complex conductivity is proposed in which
a simple debye mechanism results in a semicircular locus  a non zero
value of dc conductivity does not cause this plot to lose its unique
shape in the low frequency range
   /
3425
theory of superconductivity
   /
3426
temperature rise of solid junctions under pulse load  the magnitude
and duration of current pulses are correlated with temperature rise
in the junction  use of successive approximations assuming that
various parts of a body are not yet subjected to a temperature increase
or have already reached a temperature differential corresponding
to the steady state reduces the problem to a simple case of heat
diffusion
   /
3427
charged particles in a nonuniform radio frequency field  under certain
conditions particles of either sign will experience an acceleration
towards the position of least field strength  such an acceleration
is demonstrated in a slotted magnetron having no magnetic field and
a cold cathode
   /
3428
theory of ferromagnetic anisotropy  by means of a virial theorem
and perturbation theory the anisotropy energy of a ferromagnetic
crystal is expressed in terms of the coulomb energy alone  this is
approximated by a multipole expansion and the anisotropy constants
are given in terms of electric multipole moments and crystalline
potential constants  the multipole moments which arise from the orbital
angular momentum induced by spin orbit coupling have been estimated
from the known values of angular momentum
   /
3429
effect of crystalline electric fields on ferromagnetic anisotropy
the effect of the electrostatic crystalline field has been considered
for a magnetic crystal in which the ions are strongly coupled by
ferromagnetic exchange  on the basis of the one ion approximation
that the exchange can be represented by a weiss molecular field expressions
for the anisotropy constants have been derived  the treatment
assumes that the magnetic electrons can be considered as localized
on the individual ions and thus applies primarily to nonmetallic
substances such as ferrites
   /
3430
the time sequence and amplitude distribution of barkhausen jumps
report on discussion of results obtained in investigations of the
magnetization of fe ni alloy wire specimens to determine the dependence
of barkhausen jump characteristics on field strength and specimen
shape
   /
3431
some new aspects of the reflection of electromagnetic waves on a
rough surface  the roughness is represented by electromagnetically
interacting hemispherical bosses whose radii and mutual distances
are small relative to the wavelength  the effects of such a surface
on both vertically and horizontally polarized radiations are considered
as functions of the angle of incidence
   /
3432
apparatus for the experimental study of the diffraction of centimetre
waves  apparatus operating at is described for determining the phase
and intensity at any point of the em field  two versions are presented
one for the investigation of diffraction near the axis and the other
for the distant diffraction field  the effect of diffracting bodies
less than in size can be detected
   /
3433
diffraction of cm electromagnetic waves by dielectric rods part lucite
diameter semicylinder fields very close to surface  the diffraction
field is examined very close to the surface of a lucite semicylindrical
rod with its plane surface at various orientations relative to the
axis of propagation of the incident wave  parts of
   /
3434
the microwave spectrum of and in the cm and bands
   /
3435
the characteristic frequencies of negative molecular ions of oxygen
between and observed in ionized air discharge tubes  absorption frequencies
are determined from the current variations in a coil round a
discharge tube containing pure air supplemented in some cases by
at pressures of  absorption frequencies above give rise to strong
absorption at pressures below mm hg
   /
3436
noise temperature measurement on a solid state maser
   /
3437
radio pictures of the sun  a radioheliograph erected at sydney australia
combines the principles of the multi element or grating interferometer
and the mills cross  it consists of two rows of parabolic aerials
of diameter arranged in the form rm of a cross each row being long
diagrams of the lower corona have been prepared from observations
of radiation
   /
3438
investigation of scintillation of the sun observed at a wavelength
of cm  results of observations including simultaneous measurements
at and cm indicate that scintillations are of atmospheric origin
and are related to zenithal height solar activity and wavelength
the apparent diameter of the sun also fluctuates
   /
3439
investigation of the scintillation of the sun observed using several
aerials on a wavelength of  results of measurements of scintillation
made with three receivers at variable distances show that the average
dimension of the ground shadows is their velocities are compared
with those of winds at the altitude of the tropopause
   /
3440
polarization of solar radio outbursts  changes in the polarization
of rf emission at were recorded at tokyo on july during a solar flare
   /
3441
the scattering of radio waves by the moon  measurements of the rapid
fading of echoes at a frequency of show that the effective scattering
region has a radius of about one third of the lunar radius and is
located at the centre of the visible disk  range measurements indicate
that the echo is returned from the front edge with a power reflection
coefficient of  see also of browne et al
   /
3442
sweets mechanism for merging magnetic fields in conducting fluids
the mechanism is investigated in a semi quantitative manner  if two
oppositely directed sunspot fields having scales of about km were
brought together sweets mechanism would allow them to merge in about
two weeks  the mechanism gives a means of altering quickly the configuration
of magnetic fields in ionized gases and converting magnetic
energy into kinetic energy of the fluid
   /
3443
the solar flare of february its cosmic and geophysical effects  records
of the intensity of cosmic rays and of atmospherics show that a sudden
large increase in the former at was accompanied by a sudden decrease
in vlf atmospherics particularly as observed at bagneux at km
   /
3444
the earth and its magnetic field  review of modern theory which attempts
to explain the presence and properties of the observed magnetic field
in terms fully compatible with the structure of the earth determined
independently  references
   /
3445
the effect of solar flares on the the geomagnetic field  the dynamo
equation is solved for a conductivity produced by solar flare ultraviolet
radiations from the sun  the crochet amplitudes in horizontal
field components are then computed and compared with observed results
it is found that fair agreement exists between the theoretical and
experimental values only if the seat of the crochet current system
is within a few kilometers of the current system producing the quiet
day solar variation
   /
3446
sudden commencements of magnetic storms and atmospheric dynamo action
statistical analysis of world wide magnetic data discloses an appreciable
diurnal change in the amplitude of scs  the average electric current
system for the disturbance diurnal variation shows marked concentrations
in polar regions and suggests that the system exists within the earths
atmosphere while the current system of the storm time variation would
appear more likely to be of extra terrestrial origin  a dynamo theory
is applied to explain the atmospheric part of magnetic disturbances
and a consistent wind system is obtained to produce current systems
for magnetically quiet and disturbed days  this system contains diurnal
and semi diurnal terms and its order of magnitude agrees with recent
ionospheric wind observations
   /
3447
the geophysical year and the ionosphere  discussion of the organization
and program of the igy with particular reference to ionospheric measurements
and techniques
   /
3448
radio observations of the russian earth satellite  observations were
made at and at the mull rd radio observatory cambridge using interferometer
and doppler techniques  details of the calculation of the orbit
are given and possible new methods of finding the distribution of
electron density with height are suggested
   /
3449
observations on the orbit of the first russian earth satellite  report
of calculations carried out at the royal aircraft establishment farnborough
hants to determine orbit constants from interferometer and doppler
measurements  observations of signal amplitude and fading indicate
that the ray path of long distance transmission from the satellite
to a receiving station is complicated
   /
3450
radar observations of the first russian earth satellite and carrier
rocket  a note of instruments used and observations made at jodrell
bank at frequencies of and with pulse durations of and respectively
   /
3451
further radio observations of the first satellite  reports of interferometer
measurements at made at urbana illinois and doppler measurements
at made at chelmsford
   /
3452
charge transfer reactions  an improved method for determining charge
transfer cross sections is applied to symmetric and unsymmetric reactions
for a large number of gases and gives higher values than originally
reported  a comparison of the rates of collisional processes in the
d e and f region shows that the charge transfer rate is much larger
than that for any other collisional process in the upper atmosphere
see of
   /
3453
an appraisal of photon counter measurements of upper atmosphere parameters
a model atmosphere has been computed from measurements of density
and o concentration using rocket borne photon counters near km  inconsistencies
have appeared and it is concluded that the density at km
is higher than that found using photon counters
   /
3454
calculation of group indices and group heights at low frequencies
a formula is derived from which the group index designated for normal
incidence including collision effects can be easily computed as a
function of the real and imaginary parts of the refractive index
for frequencies below a set of curves can then be prepared from which
the group height to be expected from a given electron density profile
can be quickly determined by graphical methods
   /
3455
the movements of sporadic e layer clouds  the drift speed of isolated
clouds was measured by observing the beat between a ground wave signal
from a cw  transmitter and the sky wave reflected from the moving
cloud  comparison of these observations made at night with other
evidence suggests that scattering is greater than in the day  a method
for determining the direction of drift is suggested
   /
3456
relation between virtual and actual heights in the ionosphere  a
mathematical discussion of the various methods of determining the
distribution of electron density with height in the ionosphere and
a treatment of the comparison and integral methods  an annotated
bibliography with references is given
   /
3457
the coefficient of diffusion of ions in the f regions  the application
of sutherlands molecular model to the f region gives too large a
coefficient of diffusion if recent rocket estimates of f layer molecular
density are correct  if langevins formula for the diffusion coefficient
is used instead the discrepancy is less but for an f region in which
diffusion is in inappreciable calculated values of the coefficient
are still about times too large  possible influencing factors are
discussed
   /
3458
the origin of the ionospheric irregularities responsible for radio
star scintillations and spread f part  the present state of knowledge
about the irregularities responsible for radio star scintillations
is summarized and the existing theories of the origin of these irregularities
are discussed  all of the suggestions are shown to be inadequate
to explain the observed features of scintillations and spread f
it is shown that any i nizing agent from outside the earths atmosphere
is unlikely to be responsible for the ionospheric irregularities
that cause radio star scintillations and that the mechanism for their
production must be sought in the terrestrial atmosphere
   /
3459
the origin of the ionospheric irregularities responsible for radio
star scintillations and spread f part  a theory is presented which
attributes the occurrence of ionospheric irregularities in the f
region to turbulent wind motion in the dynamo region at a height
of km  the resulting turbulent component of the electric potential
field produced is communicated to the f region as suggested by martyn
where magneto electric forces then cause the ionization to form eddies
it is suggested that the absence of daytime scintillations is due
to the inhibition of turbulent flow by large temperature gradients
during the day  the theory is then shown to explain the major features
of radio star scintillations together with the long term correlation
of scintillation amplitude with magnetic activity and the variation
of spread f and scintillations at different parts of the earth over
the sunspot cycle
   /
3460
diurnal absorption in the d region  an analysis of the diurnal variation
of cosmic noise at from which are derived the d region electron density
and an exponential approximation to the vertical distribution of
nitric oxide
   /
3461
the electron content of the ionosphere  report of an investigation
noted earlier using radio echoes from the moon to determine the electron
content  the apparatus and the methods of analysis are described
results for seven periods between october and september are given
an almost constant ratio is found between observed electron content
and that expected in a parabolic layer  there is some evidence for
tidal effects
   /
3462
a critical discussion about special ionospheric characteristics
twelve month running means of f and r are compared for locations
and linear relations between the two are apparent for limited regions
deviations from linearity may be genuine at some locations and due
to magnetic effects but may arise from observational errors and inconsistencies
at others  present data are inadequate for examination of
m factors on a world wide basis
   /
3463
the sunspot cycle and radio communications
   /
3464
some problems of the physics of the ionosphere part fluctuation of
the electron density and scattering of radio waves  electron density
usw scattering and turbulence of the ionosphere are discussed and
experimental results are analysed  references
   /
3465
curvature induced error in the analysis of fading records  curvature
of lines of maximum amplitude in a radio field strength pattern drifting
cross an array of three receivers can introduce an error into the
estimate of the drift velocity but the error is expected to be large
only infrequently the mean error is sm ller for an array of receivers
at the corners of an equilateral triangle than for one at the corners
of a right n angled triangle
   /
3466
radar observations of lightning on metres  the echo cross section
was approximately m the visually estimated echo duration approximately
and the horizontal extent several miles  the associated atmospherics
are described
   /
3467
me surements of the absolute intensity of the aurora and night airglow
in the region
   /
3468
ra  io reflections from aurorae  a further study o fradio echoes
at following earlier work by bullough and kaiser  good correlation
is found between the daily frequency distribution of echoes and the
mean daily variation in magnetic disturbance at eskdalemuir  results
and conclusions conflict with the chapman ferraro martyn theory
   /
3469
uhf radar observations of aurora  radar echoes have been obtained
on a frequency of at south dartmouth mass  the diurnal and seasonal
variations in the occurrence of echoes is discussed and also the
conditions required to obtain echoes
   /
3470
the waveforms of atmospherics and the propagation of very low frequency
radio waves
   /
3471
vh radar echoes associated with atmospheric phenomena  during observations
with radar equipment at echoes were obtained which could not
be attributed either to aurorae or to meteors  the characteristics
of these echoes suggest that they may be due to upward discharges
from the troposphere to the ionosphere which may be triggered off
by meteors
   /
3472
semiconductors shrink servo system size  a velocity type servo
system in which the network design is based on the constant current
driving source and low impedance load conditions imposed by transistor
operation  output impedance is reduced considerably by using a double
common collector power stage with inverse feedback
   /
3473
th effects of dust and force upon certain very li  ht electrical
contacts  a quantitative relation is established between dust concentration
and contact failure  an examination of contact loading  shows
that contact resistance may rise rapidly at loadings less than mg
unless surface films can be permanently removed
   /
3474
progress report on semiconductor rectifiers  findings indicate that
silicon and germanium rectifiers are more desirable in high temperature
areas while selenium retains its superiority in high c rrent uses
   /
3475
de ign of magnetic circuits for miniature relays  the polarized type
of relay with a rotary armatur is suggested as the most suitable
type for miniaturization
   /
3476
the solion an electrochemical transducer  the operation of this device
is based on concentration polarization where an electric current
passing through an electrochemical system is limited by dif  usion
and convection variables such as fluid f ow  the solion consists
of a small cylinder of p  astic material containing a potassium iodide
solution in which two or more electrodes are immersed polarization
is effected by a battery  when the unit is stimulated by light heat
sound pressure or movement the resultant hydraulic flow within the
cell produces a current output  these r  actions are reversible
   /
3477
wa xelectrolyte batteries  two types of punched cell battery have
been developed  they are long and respectively and in diameter with
short ci cuit current and  a cell is stamped from a three layer sandwich
consisting of a zn sheet a conductive vinyl film and between the
two layers a separator impregnated with a zncl polythylene glycol
mixture
   /
3478
self setting servo gate  simple circuit used in ionospheric pulse
experiments picks out pulses transmitted at a fixed repetition frequency
in the pres ce of random noise and improves reliability of synchronizing
link by factor of
   /
3479
basic magnetic logic circuits in computers  classification of fundamental
circuits which can be realized by means of square loop ferromagnetic
cores
   /
3480
the design of the control unit of an electronic digital computer
the design of the control or sequencing unit is discussed  in one
system the order code is determined by the arrangement of the diodes
in a diode matrix and in another by the threading of wires through
a matrix of ferrite cores
   /
3481
analogue multiplier based on the hall effect  discussion of the application
of the hall effect for electronic multiplication of voltages
an investigation of semiconductors shows si to be the best for accurate
multiplication  the choice of crystal dimensions is discussed with
reference to the solution of a potential problem with skew boundary
conditions which determines the hall voltage
   /
3482
an accurate electroluminescent graphical output unit for a digital
computer  the unit is fabricated from a uniform layer of electro
luminescent phosphor with parallel conducting strips on either side
these sets of strips being at right angles to form a matrix of conductors
a changing electric field between selected strips of both sets
causes fluorescence at their intersection  intersections are selected
in turn and the pattern is recorded photographically  details of
some prototype matrices are given
   /
3483
the design of function generators using silicon carbide nonlinear
resistors  the effective current vol  ge characteristics of sic resistors
are modified by linear resistors placed in series and parallel
such modified resistors are then used as input or feedback components
in amplifiers to give nonlinear functions  design details are given
of squie law and sine function generators using this device
   /
3484
magnetic switching circuits for the representation of logical relations
a design method is derived for obtaining the number of cores and
the number of turns required on each core for a given sw itcing function
results of a systematic investigation are given for switching functions
with two and three variables
   /
3485
a bista able element suitable for use in digital computers parts
the development of a trigger c ircui using pnp and npn transistors
is described  switch on and switch off times of are achieved with
a high current carrying capacity enabling several other circuits
to be driven from it  th transient response of the circuit to a voltage
rap input at either the turn on or turn off terminals is analysed
mathematically  the results thus obtained assuming certain operating
conditions show good agreement with experimental observations a decimal
adder using a stored additional table  a description of a serial
decimal adder which accepts numbers in binary coded form  the binary
digits are decoded into a set of pulses which actuate a built in
addition table storing all the po sible sums
   /
3486
word generator for digital testing  a beam switching tube supplies
arbitrary nine bit words at pulse rates from a few to for testing
and evaluating digita systems  pulse shape can be varied from spike
to square wave by changing plug in capacitors
   /
3487
the reactance valve at audio frequencies  the reactance valve circuit
is analysed to derive circuits producing an inductive impedance at
af with pa ticular reference to obtaining a a large q fac tr
   /
3488
approximate relations between transien and frequency response  an
existing graphical method for deriving the transient response of
a linear netwo  k from the sinusoidal frequency response and vic
eversa is extended to cover certain difficult cases  typical examples
are illustrated
   /
3489
the application of printed circuit techniques to the design of microwave
components
   /
3490
developments in printed microwave components
   /
3491
the locking band for the automatic phase control of frequency  formulae
are derived relating the locking band to the filter parameters and
the delay time of the circuits
   /
3492
des  gning transformers for blocking oscillators  design procedure
based on four common circuits is given the pulse shape is calculable
and a size reduction over previous units is obtained with a type
core
   /
3493
an extened general network theorem on rectification  extension of
gewartowskis theorem
   /
3494
a new type of construction for high grade transductor cores  improvements
of laminated core design and assembly are discussed which permit
a better utilization of the qualities of the material
   /
3495
calculation of the duration of a quasi equilibrium state in a phantastron
circuit  a formula is derived and typical operating conditions
of phantastron circuits are considered
   /
3496
transistor circuits for use with gas filled multicathode counter
valves  transistors are used in conjunction with dekatrons to provide
a logical circuit the combination is run off a low voltage supply
the hv to the dekatrons being supplied by a transistor dc converter
a block of these circuits is made to function successfully in a telephone
exchange register
   /
3497
ceramic capacitors a complete substitute for paper and mica capacitors
the electrical characteristics of paper mica and ceramic capacitors
are compared  performance tests on receivers before and after substituting
ceramic for paper capacitors show no significant difference
   /
3498
the sense of rotation and curvature of the impedance loci of real
and ideal two poles  the impedance of a two terminal network as represented
on thegauss number sphere describes a closed curve revolving
completely at least once in a clockwise direction for a frequency
variation from  a method is given for synthesizing two poles which
h  ve impedance loci turning anticlockwise in places
   /
3499
design of complex resonators  an investigation of resonators consisting
of several uniform coaxial line sections with different characteristic
impedances
   /
3500
microwave high power simulator  by periodically injecting energy
from a directional coupler into a waveguide cavity made in the form
of a closed loop much higher power levels can be achieved than are
available from microwave power generators  energy is stored in a
circulating or travelling wave  see also of
   /
3501
the scattering matrix in network theory
   /
3502
frequency transformations in filter design
   /
3503
optimum filters with monotonic response  the amplitude characteristic
has no ripple in the pass band and a high rate of attenuation in
the stop band and combines the desirable features of the butterworth
and tchebycheff response
   /
3504
a twin t variable slope filter  by suitable modification a twin t
notch filter is converted into a low pass filter in which the rate
of attenuation up to a specified upper frequency is controlled by
a single potentiometer  design data are given and a detailed circuit
is described
   /
3505
filters built from coaxial conductors  zobels method of filter design
is applied to coaxial line filters considering the impedance of the
line as a function of frequency  characteristics can therefore bermined
for the entire frequency range  design data are shown in a series
of tables and four types of filter section are discussed in detail
   /
3506
a filter with characteristics approximating to those of an ideal
low pass filter  the design and construction of a filter are described
whose characteristics conform closely to those of the idea l lw pass
filter specified by kupfmuller  the variations of its amplitude response
up to cut of  at are less than  at cut off the response is of its
maximum value and the fluctuations of grou  delay are less than
   /
3507
rc and lc resonant filters and their application i  selective amplifiers
the design of a narrow b nd amplifier with a centre frequency
of about is discussed following a comparison of circuits with different
types of filter elements  a two stage circuit with negative feedback
and incorporating a rc band stop filter was the design adopt  d or
use in the measurement of the solar magnetic field
   /
3508
an approach to the design of constant resistance amplitude equalizer
networks  a method of designi  g constant resistance amplitude equalizers
to give a desired frequency response characteristic over a given
range is suggested  a typical example illustrates the method of adjusting
the response of a velocity type pick up over part of the af spectrum
   /
3509
a treatment of cascaded active four terminal networks and with application
to transistor circuits
   /
3510
self oscillator with large circuit attenuation  the optimum operating
conditions for power transfer to the load and the efficiency of the
oscillator are discussed  equations are derived and graphs show the
grid voltage variations for different values of attenuation
   /
3511
amplitude stabilized low frequency oscillator  the performance of
a vlf oscillator for the range with the output stabilized by biased
diodes or lamps is analysed  formulae for the harmonic content with
different initial damping are deduced and means of reducing it are
indicated  a circuit for measuring the harmonic content is described
   /
3512
double tetrode oscillator  the oscillator covers a frequency range
of and can be anode modulated with pulses repeated at a rate of about
constructional details are given
   /
3513
crystal oscillator has variable frequency  a maximum frequency deviation
of is obtained from a two stage crystal feedback amplifier operating
at with a long term frequency stability within a few parts per million
   /
3514
frequency stabilization of usw oscillators by using harmonics for
the excitation of the quartz crystal  modern methods of direct stabilization
of d  rect stabilization of usw oscillators by quartz crystals
are reviewed  circuits are described in which the static capacitance
of the crystal is compenated by inductance  simple bridge circuits
for operation over a range of frequencies are also described in which
the crystal is excited by high order harmonics  uncompensated circuits
are also considered and comparison is made between the various types
of circuit
   /
3515
a three phase three valve multivibrator  a three valve circuit in
which each amode is capacity coupled to the other two grids is described
frequencies up to are obtained using miniature rf pentodes
   /
3516
generation of bell shaped pulses  a pulse generating circuit is described
for producing pulses to long at a repetition frequency of
   /
3517
transients in pulse circuits with point contact transistors  analysis
based on the dynamic characteristics of transistors  transient processes
in relaxation oscillators and triggering circuits are examined
   /
3518
a carrier energized bistable circuit using variable capacitance diodes
a variable capacitance junction diode when used in a simple circuit
driven from a high frequency source can cause that circuit to have
a bistable characteristic suitable for dynamic storage or to have
a sensitive output input characteristic suitable for control or detection
purposes
   /
3519
adjustable electronic delay circuit for the microsecond range  a
modification of a pulse discriminator circuit of a type described
by moody et al using secondary emission pentodes is described  by
means of an adjustable capacitance coupling dynode and grid the time
interval between successive negative and positive pulses derived
in the circuit can be adjusted between and for an application of
the method in a delayed coincidence circuit see
   /
3520
binary frequency divider with unction transistors
   /
3521
limited gain operational amplifiers  the effect of finite gain can
be allowed for by assuming infinite amplifier gain and then adding
fictitious elements to the feedback network to reduce the gain to
its actual value  this leads to a more convenient equivalent network
of which simple examples are given
   /
3522
parallel t rc selective amplifiers  the operation of a less familiar
form of selective amplifier with low impedance input is analysed
in which the signal is injected at the null point of the parallel
t network in the feedback loop  design equations are derived and
applied as an example to a fixed tuned amplifier with a square wave
input
   /
3523
electronic equalizer  description of an af amplifier with variable
boost or attenuation at both the low and high frequency ends of the
response characteristic  typical response curves of the amplifier
are shown
   /
3524
hum in audio stages  a design procedure based on measurements on
typical valve types for reducing hum in the audio stages of ac dc
equipment
   /
3525
design of feedback amplifiers for prescribed closed loop characteristics
   /
3526
modified rice neutralization  the theory of rice and modified rice
neutralization are discussed an formulae are derived for maximum
stability with no feedback voltage on the grid  the conditions for
positive and negative feedback are also derived
   /
3527
subminiature magnetic amplifiers  a description of circuits using
a new ferristor fast saturable reactor which may be used as a magnetic
amplifier or as a bistable ferroresonant element
   /
3528
transistor bias circuits  a detailed comparison of four bias circuits
with reference to performance and the operating point stability
a practical stability factor is derived together with general design
formulae for bias components  the
   /
3529
the use of universal curves in the design of transistor amplifier
stages  design curves are derived from the principal transistor parameters
for linear operation at low frequencies
   /
3530
dc transistor amplifier for high impedance input  a short discussion
and circuit diagram of an amplifier using a double emitter follower
and grounded emitter voltage amplifier  temperature compensation
gives short term drift stability  the input impedance is and the
current gain
   /
3531
theory of parametric amplification using nonlinear reactances  the
parametric amplifier is analysed phenomenologically in terms of
an equivalent circuit model  the model consists of a signal circuit
resonant at an idling circuit at and a pumping circuit at these three
circuits being coupled across a nonlinear inductance  the analysis
is general enough to delineate the conditions on the signal level
and circuit parameters which lead to distortionless amplification
expressions are derived for power gain bandwidth and noise factor
for the case in which the signal and idling frequencies are well
separated and for the degenerate case in which these two frequencies
are equal
   /
3532
solid state maser amplifier  the operation of a solid state maser
amplifier at is described  a dual frequency cavity containing paramagnetic
potassium chromicyanide in an isomorphous cobalt diluent is used
at k  the upper three of the four energy levels of the cr ion are
used  spin state populations are inverted by saturating the resonance
absorption at  the experimental observations of the maser both as
an amplifier and as an oscillator are compared with theory
   /
3533
new approaches to the amplification of microwaves  the basic principles
governing the operation of two new types of molecular microwave amplifier
the maser and the parametric amplifier are described  both types
of amplifier have relatively narrow bandwidths but excellent noise
properties
   /
3534
ferrite microwave detector  it is shown theoretically that second
order terms in one component of the magnetization of a ferrite under
the action of a rf field may be used to produce magnetostriction
in the ferrite and so to detect an am microwave signal  an experimental
technique is described in which the detector consists of a long thin
ferrite rod in a waveguide  magnetostriction vibrations are observed
by means of a polarized ceramic rod bonded to the ferrite  the qualitative
results agree with theory and factors which are expected to improve
performance are discussed
   /
3535
noise output of balanced frequency discriminator  a mathematical
analysis for gaussian noise input assuming no limiter action
   /
3536
a conductivity storage transistor pulse width modulator  transistors
of both point contact and junction types exhibit in certain pulse
applications prolonged conduction generally ascribed to hhole storage
this can be controlled in a circuit to provide a simple means of
pulse width modulation for time division multiplex  the technique
is described for use with selected point contact transistors
   /
3537
thermoelectric effects  the basic principles of thermoelectricity
are reviewed recent achievements are outlined in terms of specific
practical applications n and the present status of the more detailed
theoretical treatments is discussed in a nonmathematical fashion
useful equations describing important parameters are tabulated  over
references
   /
3538
optical theory of thermal velocity effects in cylindrical electron
beams  the present theory is based on a nonlaminar optical model
which treats thermal velocities as an integral part of the motion
a maxwellian distribution of initial transverse velocities is assumed
at the cathode and a first order focusing theory is applied in order
to calculate trajectories at any point in the beam  it is shown that
whenever a long beam is confined by a focusing field images of the
cathode are formed repeatedly along the axis  when applied to uniform
magnetic focusing fields the theory predicts the periodic formation
along the axis of cathode images and crossovers and a relative rotation
of successive images  such effects have been reported
   /
3539
effect of variation of dc current in a modulated electron beam  experiments
indicate that existing theory needs correction  an empirical
formula satisfying all experimental observations is difficult to
obtain
   /
3540
oscillations in plasma part  a sensitive super regenerative detector
was used to study oscillations in a looney brown tube without auxiliary
electron beams  oscillations were detected by a small external aerial
   /
3541
nonlinear effects in electron plasmas  a mathematical study of three
groups of effects namely the excitation of harmonics coherent interaction
and incoherent interaction  complications of finite boundaries
external fields non zero temperature multistream flow and collisions
are ignored  the main interest is in the incoherent interaction which
results in spectral decay and damping effects are compared with experimental
data
   /
3542
waves in a plasma in a magnetic field  an analysis of the small amplitude
oscillations of a fully ionized quasi neutral plasma in a uniform
externally produced magnetic field  no self excitation of waves around
thermal equilibrium is predicted  in contrast to the results of gordeyev
for longitudinal electron oscillations propagated perpendicularly
to the constant magnetic field there are gaps in the spectrum of
allowed frequencies at multiples of the electron gyration frequency
but zero landau damping  when the ion dynamics are included two classes
of low frequency oscillations are found and the results for the propagation
of em waves in an ionized atmosphere are also derived
   /
3543
conductivity of plasmas to microwaves  the complex conductivity is
calculated for a neutral plasma with electrons having a distribution
in space and velocity which does not change over a time interval
long compared with the period of the microwave field  the conductivity
is derived for velocity distributions given by the dirac function
a step function and a maxwellian distribution
   /
3544
plasma diffusion in a magnetic field  the equations governing the
diffusion of a fully ionized plasma across a magnetic field are derived
it is assumed that macroscopic quantities vary slowly across an ion
radius of gyration and that the interparticle collision frequency
is much less than the gyration frequency  the relevant transport
coefficients electrical resistivity thermal conductivity and thermoelectric
coefficient are derived  some similarity solutions of the equations
are found
   /
3545
nonlinear electromagnetism and photons in the functional theory of
particles
   /
3546
new tables of total mie scattering coefficients for spherical particles
of real refractive indexes  k the total mie scattering coefficient
is defined as the total flux scattered by the particle divided by
the flux incident on its cross section the size parameter the theory
applies only to a very dilute aerosol of randomly arranged spheres
and does not allow for coherence in the field or for multiple scattering
has been calculated on an electronic computer for in steps of
and for and
   /
3547
scattering of electromagnetic waves by lo  g cylinders  the field
scattered by a metal or dielectric cylinder when excited by a wave
propagated in a direction normal to the cylinder axis is discussed
theoretically for plane and cylindrical waves  the radius of the
cylinder is comparable with the wave length  the dielectric cylinder
is a resonant structure
   /
3548
propagation through a dielectric slab  propagation from a point source
through an infinite slab is considered theoretically with particular
reference to the apparent source and its modified polar diagram
an appreciable change in polar diagram can be produced by even a
thin sheet of dielectric
   /
3549
the microwave spectrum and structure of trichloracetonitril  the
microwave spectrum of as been studied in the range using a stark
modulation microwave spectrometer
   /
3550
nuclear magnetic resonance  the phenomenon is briefly discussed and
the pound system for its detection is described  for high resolution
work the bloch spectrometer is particularly suitable
   /
3551
audio frequency nuclear resonance echoes  a spin e ho technique for
determining nuclear magnetic resonance by experiments in the earths
magnetic field is described  it is possible to derive the true spin
spin relaxation time even if the field is not homogeneous
   /
3552
the radio telescope at the royal radar establishment malvern
   /
3553
radio noise from planets  a comparison is made of hf radio noise
from jupiter and venus and from terrestrial lightning  the hypothesis
that radio noise from the two planets is due to electrical discharges
analogous to terrestrial lightning requires modification
   /
3554
the distribution of radio brightness over the solar disk at a wavelength
of centimetres part the s  owly varying component  the emitting regions
were studied individually using a element interferometer producing
fringes of arc in width  during the radio sources were found to lie
about above and to have the same size as plages faculaires  the angular
distribution of radio flux follows approximately a cosine law suggesting
that thet the source is a thin shell parallel to the suns  surface
the correlation between radio flux and sunspot areas is discussed
part
   /
3555
meteor radiant determination from high echo rate observations  a
simplified analysis is given of the clegg method for delineating
meteor radiants from radar observations see of  a further analysis
reveals a new and faster method of interpreting the data contained
in meteor echo records  this method is applicable when sensitive
equipment is employed and the resulting echo rate is very high
   /
3556
the association of solar radio bursts of spectral type with chromospheric
flares  simultaneous optical and radio observations were made
for over flares of which were of class and of which are associated
with type events  of the bursts were recorded during the life of
the flare usually near the beginning  the probability of a burst
accompanying a flare is greater for large flares and is the same
for flares on the east limb as for those in the centre of the disk
this implies a wide cone of escape for type radiation
   /
3557
a new effect of chromospheric eruptions
   /
3558
bureau of standards role in igy  a short summary of the work undertaken
   /
3559
radio research and the igy  the objectives and organization of the
igy are outlined  the programs of observations which are of particular
interest to radio engineers and the users of rockets and satellites
are described
   /
3560
artificial earth satellites
   /
3561
radio observations on the russian satellites  the following short
contributions were presented at a meeting of the radio and telecommunication
section of the iee london november  observations at cambridge
apparatus used at the royal aircraft establishment  some direction
finding observations on the signal  observations of bearing and angle
of elevation of satellite i  estimating the height of the first satellite
from radio interferometer records  precise frequency measurements
on first russian satellite  analysis of doppler data from earth satellites
radio observations of the signal characteristics of satellite
radar observations of the russian earth satellites and carrier rocket
observations at the royal radar establishment  discussion
   /
3562
ranging the satellite by doppler shift observation  an experimental
m  thod using simple apparatus
   /
3563
unusual propagation at from the ussr satellite  interferometry recordings
were obtained in washington on a few occasions during october
when the satellite was on the opposite side of the earth near an
antinodal point
   /
3564
a note on some signal characteristics of sputnik
   /
3565
detection of sputniks and by cw reflection  the method described
is based on the reception of the transmission of wwv at a distance
of about miles
   /
3566
the last days of sputnik  deductions are based on radio reflection
records using wwv transmissions on
   /
3567
proceedings of the polar atmosphere symposium held at oslo july part
ionospheric section  the text is given with ensuing discussions of
papers presented at the symposium  abstracts of some of these are
given individually  titles of others are as follows results of ionospheric
drift measurements in the united states  results of ionospheric
drift measurements in norway  movements of ionospheric irregularities
observed simultaneously by different methods  turbulence in the ionosphere
with applications to meteor trails radio star scintillations
auroral radar echoes and other phenomena  geographic distribution
of geophysical stations on the polar cap  a theory of long duration
meteor echoes based on atmospheric turbulence with experimental confirmation
   /
3568
theoretical views on drift measurements  the conversion of the amplitude
pattern drift at the ground as sampled by three closely spaced receivers
to the true drift in the ionosphere requires the ionosphere requires
the determination of auto and cross correlation functions  problems
in relating ground pattern drift to ionospheric drift are stated
   /
3569
the drift of an ionized layer in the presence of the geomagnetic
field  the efficiency of air winds in causing ionization drift decreases
with atmospheric pressure  thus in the f region electric fields may
be the main cause of drift in the region electric fields may contribute
equally with air winds in the d region air winds would be the main
cause  the effect of winds and fields is causing drifting of cylindrical
irregularities in each region is given
   /
3570
the height variation of horizontal drift velocities in the e region
the drift was measured on two adjacent frequencies corresponding
to heights of reflection differing by about km  the diurnal change
in the ns and ew velocity components differs in phase at the two
heights
   /
3571
large scale movements of the layers  moving wavelike disturbances
with appear to travel with inclined wavefronts having both horizontal
and vertical motions which are often of similar magnitudes and the
with varying direction  the effects are independent of magnetic activity
and are probably not caused by atmospheric winds  a travelling compressional
wave is suggested as an alternative to motion caused by electric
fields
   /
3572
electron distribution in a new model of the ionosphere  rocket measurements
between and for pressure density and temperature are used to
derive a new empirical model for temperature and electron density
in the ionosphere  this model agrees well with the theory of temperature
variation and radio measurements of electron density
   /
3573
some implications of slant e  slant e is common in polar regions
the virtual height of traces rising from up to  a linear characteristic
passing through the origin relates virtual height and frequency
it is suggested that slant e is due to back scatter from e  four
modes of propagation are possible direct back scatter reflected back
scatter single reflected scatter double scatter experiments are suggested
which would distinguish between them
   /
3574
an easily applied method for the reduction of hf records to nh profiles
including the effects of the earths magnetic field  the method depends
on sampling h at fixed submultiples of the frequencies at which true
heights are required  the latt r are then obtained by averaging the
values of h  a complete computation is presented for washington dc
and the results checked against an analysis of curves for known profiles
   /
3575
the electron distribution in the ionosphere over slough part quiet
days  the distribution of elect  on density with height is calculated
from records using an electronic computer  the method assumes sumes
that the curve increases monotonically and allows for the effect
of the earths magnetic field  the height of maximum electron density
in the f layer is found to be considerably lower than previously
supposed particularly in the summer and equinox months
   /
3576
the height variation of drift in the e region  simultaneous observations
at and of drift velocities show significant differences and it is
deduced that they refer to different heights  the velocities rotated
through at a nonuniform rate during daylight hours the nonuniformity
is due to the variation of reflection height  in the winter months
the rotation at the smaller height lagged with respect to that at
the larger  rapid changes in drift were observed during september
and october  the results agree with those deduced by greenhow and
neufeld of from meteor trail observations if allowance is made for
the height differences
   /
3577
solar tidal effects in the f region of ionosphere over delhi  harmonic
analysis of and shows the existence of semi diurnal and seasonal
solar tidal effects in the f layer at delhi  vertical drifts of in
summer in winter and at the equinoxes are calculated from ionization
density variations  attachment coefficients including these tidal
effects worked out for different seasons are in agreement with those
obtained by ratcliffe et al
   /
3578
a study of the ionospheric irregularities which cause spread f echoes
and scintillations of radio stars  a discussion of the correlation
between the occurrence of spread f echoes at slough inverness and
oslo  the irregularities responsible for the spreading occur in bands
which lie along parallels of latitude and have a width of the order
of km  it is suggested that the irregularities occur at heights near
km
   /
3579
ionospheric records of solar eclipses  the horizontal gradients of
ionization produced during an eclipse introduce curvature into the
isoinic contours so that the ionosonde soundings are effectively
oblique  the resultant errors in the deduced ion distributions assuming
vertical soundings give rise to many of the apparent abnormalities
in c eclipse records
   /
3580
travelling disturbances in the ionosphere changes in diurnal variation
the mean diurnal variation in the direction of horizontal movement
of travelling ionospheric disturbances is plotted for january and
for january in the years of  the main feature of the former is an
unusually large change of direction about midday possibly associated
with high sunspot activity
   /
3581
progress in the field of ionospheric research and tropospheric wave
propagation  report based on papers presented at a conference held
at kleinheubach germany october and organised by the german ursi
committee and the nachrichtentechnisch gesellschaft
   /
3582
ionospheric true height and muf calculations  mufs calculated from
the more accurate determinations of the electron density distribution
see above are consistently higher than the slough bulletin values
   /
3583
the spectrum of the electron density fluctuations in the ionosphere
the fluctuations are assumed to arise from the vertical transport
of small pockets of air in the presence of a non adiabatic temperature
gradient and vertical gradients o mean electron density  a preliminary
account of the theory of the spectrum o the fluctuations is given
with references to the application of the results to ionospheric
and tropospheric scattering of radio waves  see also of
   /
3584
polar disturbances  disturbances in the ionosphere and geomagnetic
field and also auroral behaviour are usually treated statistically
in this paper an attempt is made to investigate what occurred in
a few specific cases  there is some evidence for a spiral auroral
zone
   /
3585
statistical results and their short comings concerning the ionosphere
within the auroral zone  the difficulties of obtaining significant
data from high latitude curves are discussed together with the statistical
treatment of such data  these difficulties could be minimized
by the adoption of the recommendations of the ursi high latitude
committee
   /
3586
measurements of irregularities and drifts in the arctic ionosphere
using airborne techniques  special supplement part an ionospheric
recorder was installed in an aircraft and flights were made in north
polar regions  the interpretation of the experimental data in terms
of ionospheric structure is discussed  some drift measurements were
made at the north pole  see also of and
   /
3587
quantitative measurements of absorption in the auroral zone  the
various alternative methods of measuring ionospheric absorption are
discussed and the results compared with particular reference to the
north polar region
   /
3588
echoes from the lower ionosphere during polar blackouts
   /
3589
polar blackout occurrence patterns  a brief survey of the geographical
distribution of the probability of the occurrence of black outs in
north polar regions  difficulties in interpretation of the data are
discussed
   /
3590
classification of atmospheric waveforms  the desirability and requirements
of a systematic classification of atmospheric waveforms are discussed
an observational scheme is suggested and interpreted in terms
of known properties of the discharge and propagation mechanisms
these data are reviewed to clarify application of the scheme to individual
waveforms  the relation between the classification and previous
inadequate groupings is indicated
   /
3591
heat transfer in power transistors  a general discussion of thermal
problems in operating power transistors between and
   /
3592
power supply and suppression in portable mobile working  practical
details of the use of car batteries or petrol electric sets for power
supply
   /
3593
stabilized the unit  design of a compact equipment for anode supplies
of
   /
3594
improved control circuit for regulated power supplies  a cathode
follower is inserted between the control valve and the regulator
valve in an electronic voltage regulator to increase the current
range over which regulation may be maintained
   /
3595
digital codes in data processing systems  the design of digital coding
systems including error detecting and error correcting codes is discussed
   /
3596
a new cycle counting instruction for a three address electronic digital
computer
   /
3597
an electrical apparatus for solving polynomial equations  the analogue
equipment described can be used for solving equations of up to degree
with real coefficients
   /
3598
computation of arc tan n for using an electronic computer
   /
3599
the application of square hysteresis loop materials in digital computer
circuits  theories and the practical design of shifting registers
are explained  core matrix storage systems are reviewed  a description
is given of a store in which a shifting register is used to convert
the parallel output into serial form this register is also used during
the writing process
   /
3600
a decimal product accumulator  dekatrons enable the correlation between
two series of numbers to be found if all terms are positive  given
pairs of numbers of two decimal digits each the machine accumulates
products per minute
   /
3601
british built computers  a review of digital and analogue computers
with details of specifications special features and applications
   /
3602
analysis of current pulses  an approximate method of analysis used
earlier is extended to include nonlinear characteristics and its
application to a class c amplifier circuit is described
   /
3603
printed circuits and high quality amplifiers  printed circuits are
suited to equipment where standardization is essential  inherent
in this type of circuitry is improved performance special production
methods are needed to ensure reliability
   /
3604
etched if amplifier pares colour tv cost
   /
3605
simple variable voltage power supply  design details of a circuit
giving an output of at currents up to
   /
3606
electromagnetic fields in a ferromagnetic medium with particular
reference to harmonic distortion due to hysteresis  the frequency
dependence of the third order distortion factor of an inductor at
low flux densities is studied theoretically  an analogue method is
described which enables the study to be extended experimentally to
large flux densities and complex input waveforms
   /
3607
a numerical graphical method for synthesizing switching circuits
economical circuit arrangements can be rapidly developed by systematic
application of three simple rules to a numerical representation
of a boolean function  simple examples ar egiven
   /
3608
minimum energy triggering signals  the optimum signat is defined
as that which produces a given current through or a voltage across
a resistive output element at a given time while requiring a minimum
of energy from the generator  the solution of this problem is discussed
and illustrated by a simple case
   /
3609
controlled saturation in transistors and its application in trigger
circuit design  carrier storage of charge in transistors has a maximum
which is defined as controlled saturation this depends only on the
base current  this idea is used to develop a trigger circuit of good
resolving time whose output terminal is able to handle heavy currents
and presents a low impedance
   /
3610
fast transistor relay  describes a push pull switching circuit incorporating
zener diodes having a rise time of and capable of handling
currents up to
   /
3611
ge  eralized operators for the approximate steady state analysis
of linear and nonlinear circuits  the method is a periodic analogue
of the time series technique by which waveforms are represented by
an component operator giving values at each of ordinates  a shift
operator translates any waveform by of the appropriate sample period
for linear circuits the method is advantageous wher ethe periodic
input is known and a similar description of the output is required
without recourse to fourier analysis  for nonlinear circuits the
output is obtained by a series of approximations applied to the
steady state condition
   /
3612
signal theory
   /
3613
system theory as an extension of circuit theory
   /
3614
derivation of the phase characteristic from the attenuation curve
in minimum phase systems  the graphical method described is illustrated
by numerical examples
   /
3615
stable crystal filter is parallel resonant  a high q unbalanced crystal
circuit is similar to a parallel tuned circuit with a low lc ratio
over an appreciable frequency range  it is readily adaptable for
use in fm oscillators signal generators and variable bandwidth filters
   /
3616
the concept of heterogeneous surface impedance and its application
to cylindrical cavity resonators  formulae are developed relating
the q factor and the resonant frequency of a cavity to its dimensions
and the fourier components of the surface impedance function  the
cases of circumferential and axial heterogeneity are analysed in
detail  in general a unique value of surface impedance cannot apply
to an unbounded periodic sheet unless the period is small compared
with
   /
3617
synthesis of tchebycheff impedance matching netwg networks filters
and interstages
   /
3618
two theorems concerning group delay with practical application to
delay correction  two theorems a  e stated which enable properties
of group delay to be expressed directly in terms of the transfer
function of a linear transmission system  examples are given to show
how the results might be usefully applied to certain problems of
delay correction
   /
3619
linear pulse forming circuits  synthesis of delay line networks
description of synthesis procedure for delay systems used in processing
continuous trace radar information
   /
3620
the network synthesis on the insertion loss basis  methods of synthesis
of most important network functions are derived in terms of the steady
state network performance realization procedures are explained and
expressed in explicit formulae for direct application to the design
of conventional ladder structures with an arbitrary number of branches
the symmetrical and the inverse impedance low pass networks are solved
in detail
   /
3621
exact ladder network design using low q coils
   /
3622
conditions for the impedance and admittance matrices of n ports without
ideal transformers
   /
3623
equivalent circuits of noisy networks  equivalent circuits for a
combination of amplifiers attenuators and terminations are presented
and a new method for the precision measurement of noise figure is
described
   /
3624
small signal heterodyne mixers with excessive injection amplitudes
the theory of small signal heterodyne mixers operating with very
large injection potentials is described  the mixer properties investigated
are the conversion transconductance the relative amplitudes of
the difference freq  ency and injection frequency components in the
output and the amplitude of the injection modulation frequency component
in the output in the case where the injection potential is amplitude
modulated to a small degree  a set of universal performance curves
is obtained for mixers of a particular class chosen to illustrate
the method
   /
3625
vxo a variable crystal oscillator  description of a stable oscillator
which covers the range and uses six crystals
   /
3626
flip flop stability  modifications to the circuit described earlier
including the use of a different type of valve do not affect its
stability in respect of pulse duration
   /
3627
transient processes in a trigger circuit with a transistor  transient
processes in a common base circuit using a point contact transistor
are considered  expressions for the currents are derived and the
speed of operation of the circuit is estimated  requirements are
formulated for point contact transistors to be used in high speed
trigger circuits  see also of
   /
3628
high sensitivity transistor pulse trigger circuit  a ge diode and
a differential negative resistance of high stability consisting of
a transistor amplifier with positive feedback u is used
   /
3629
transistorized rc phase shift power oscillator  data on the performance
of a phase shift circuit operating at frequencies around are given
   /
3630
a theorem concerning noise figures  see
   /
3631
stagger tuned band pass amplifiers  a procedure is given for designing
narrow band amplifiers with either bandwidth or rise time are specified
data are included for single tuned cascades with up to five stages
see also of
   /
3632
stability and the effects of valve input conductance in wide band
if amplifiers  an analysis of the effects of small variations of
circuit parameters and of valve input conductance on amplitude and
group delay response of double tuned interstage amplifiers  see also
of
   /
3633
some studies on delayed feedback circuits  by inserting delayed signals
along with the main signal to be observed an improvement in signal
noise ratio can be achieved  other applications of this circuit are
for producing artificial reverberation as a narrow band filter and
as a short time storage circuit
   /
3634
bootstrapped differential amplifier with reduced common mode effects
a common mode signal of changes the differential gain of the circuit
by or less  full scale deflection can be obtained on a recorder with
input
   /
3635
push pull audio amplifier theory  a mathematical analysis is given
applicable to all classes of th epush pull amplifier assuming nonlinear
valve characteristics
   /
3636
two valve pre amplifier  the performance of the amplifier is discussed
when used with magnetic and crystal pickups tape recorder play back
heads and microphone and radio inputs
   /
3637
straight pa for centimetres  design and operating details for a rf
amplifier on using a double tet  ode
   /
3638
a nonlinear low frequency instability phenomenon in audio amplifiers
under certain conditions af amplifiers with feedback may show instability
at low frequencies which is not predictable by conventional linear
analysis  the problem is analyzed theoretically with supporting experimental
results and a technique given for reducing the nonlinear effect
   /
3639
some augmented cathode follower circuits  direct coupled cathode
follower circuits with very high input and low output impedance are
described suitable for driver stages see of buffer stages and frequency
selective amplifiers
   /
3640
magnetic amplifiers basic principles and applications  a basic qualitative
description of the prin  iples of operation
   /
3641
transistor high gain tuned amplifier  particular attention has been
paid to stability of gain and bandwidth against transistor variations
over a period of months the maximum gain of about db has changed
by only with no measurable change in bandwidth  the amplifier has
been designed principally for use as a bridge detector and general
purpose amplifier but provision has also been made for transistor
noise figure measurements by the addition of a stage at the input
in which the transistor under test provides sufficient gain to make
the effective noise figure of the amplifier negligible for most purposes
   /
3642
a stable gain transformer coupled transistor af amplifier  the amplifier
is designed primarily for use with dc choppers giving a square wave
output at cs  circuit diagrams are given and the performance is illustrated
by graphs  changes in the transformer design for use at other
frequencies are discussed
   /
3643
a transistorized decade amplifier for low level audio frequency applications
national electronics conference paper
   /
3644
a generalized theory of transistor bias circuits  a general method
of analysing bias circuits is presented  almost all three terminal
bias circuits can be reduced to the same standard form for which
the analysis is given  an example from current practice shows the
unifying concepts resulting from the general theory
   /
3645
transistor amplifier stages operating from and  a description of
low level stages using a type transistor which can be used to build
rc coupled amplifiers operating in ambient temperatures up to
   /
3646
direct coupled transistor audio amplifier  description of a design
procedure for a three stage amplifier in which the collector of one
stage is di  ectly connected to the base of the following stage
see of february
   /
3647
parametric amplification using low frequency pumping  describes how
low frequency pumping is possible if two pumping sources are used
in conjunction with a nonlinear reactance having an odd order nonlinearity
an analysis of the equivalent circuit is given
   /
3648
a travelling wave ferromagnetic amplifier  amplification of signal
power can be obtained in a propagating structure which is partially
or totally embedded in a ferromagnetic medium  it is shown that one
form of the structure possesses two propagating modes and can also
support a travelling wave supplied by a local oscillator which provi
es through the magnetic changes a time varying coupling between the
two propagating modes  the principle of operation is illustrated
by a simple transmission line model
   /
3649
contribution to the theory of the molecular generator  the resonance
interaction between an electromagnetic field and a molecular beam
and self oscillatory processes in a molecular oscillator are investigated
for the case of a single velocity beam  results obtained taking
account of nonmonochromatic molecules in the beam are considered
qualitatively
   /
3650
operation of three level solid state maser at  a three level paramagnetic
solid state maser has been operated both as an amplifier and as
an oscillator at  a single crystal of about of containing as active
element is used
   /
3651
parametric amplification of space charge waves
   /
3652
the magnetic ring modulator and demodulator  advantages and disadvantages
are outlined with reference to the equivalent circuit and to a
practical modulator for use with a carrier frequency
   /
3653
multiplication of frequency modulated oscillations over an extremely
wide frequency range  the problem of multiplying in a ratio with
a fundamental frequency of is discussed with reference to the performance
of a serrasoid modulator  see also of may
   /
3654
frequency modulation by inductance variation a frequency modulation
by inductance variation a magnetically stable ferrite modulator
the operation of modulators incorporating a reactance valve or a
variable inductance is summarized  the losses in the magnetic core
of the inductance modulator are considerably reduced by using magnetic
ferrites and details of this type of modulator are given  it can
be used in simple variable frequency circuits up to
   /
3655
simple circuit stabilizes ferrite fm modulator  stabilization over
a range of frequencies is achieved by the use of an auxiliary fixed
frequency oscillator and associated feedback control circuit
   /
3656
multichannel pulse height analysers  proceedings of an informal conference
held at gatlinburg tennessee september
   /
3657
transistor af amplifiers
   /
3658
a variational principle for classical field theories
   /
3659
the definition of current charge and electric force in the unified
field theory
   /
3660
on the deduction of the lorentz einstein transformation from maxwells
electromagnetic field equations
   /
3661
precision determination of the velocity of electromagnetic waves
using an interferometer of improved performance operating at a value
has been obtained
   /
3662
investigations by microscope and oscillograph of the electroluminescence
of nonconducting diamonds  the electroluminescence is investigated
at fields strengths above cm  with very strong fields and high current
densities graphite whiskers form in the diamond at the electrodes
and the electroluminescence is thereby enhanced  oscillograms indicate
that recombination processes are a contributory cause of electroluminescence
   /
3663
magnetic interaction of electrons and anomalous diamagnetism
   /
3664
on the theory of skin effect in metals  the coefficient of em wave
transmission through a sufficiently thick film is calculated taking
into account a small slowly damped addition derived from the evaluation
of the spin magnetic moment
   /
3665
critical current for superconducting films  mathematical analysis
of critical currents for superconducting films thick
   /
3666
emission mechanism of cold cathode arcs  a new theory is proposed
in which excited atoms play a predominant role as a source for ion
generation in the vicinity of the cathode surface  the processes
of resonance ionization and of ionization in the strong electric
field at the cathode surface are considered
   /
3667
a general theorem for dense electron beams  a sufficient condition
for the existence of any particular set of trajectories is derived
for pierce type dense electron beams
   /
3668
energy loss by a charged particle passing through a laminar dielectric
part  a general expression has been obtained for losses of a particle
moving in an unbounded laminar medium or a waveguide filled with
a dielectric  polarization losses are examined and an expression
for the spectral distribution of parametric cherenkov radiation is
derived
   /
3669
electron electron interaction and heat conduction in gaseous plasmas
the thermal conductivity in low gas pressure ne and xe plasmas has
been shown experimentally to be determined chiefly by heat flow in
the electron gas of the plasma  the experimentally determined values
of the thermal conductivity are in agreement within less than one
order of magnitude with those given by the theory of spitzer n harm
   /
3670
energy exchange between electron and ion gases through coulomb collisions
in plasmas  the general aspects of energy exchange between the
electron ion and molecular constituent gases and their energy transfer
to the boundary have been examined experimentally for a partially
ionized gas  coulomb collisions between electrons and ions are shown
to contribute significantly to thermal energy transfer from the electron
gas even in weakly ionized gases  in a plasma produced in ne gas
at hg at the characteristic time for equipartition of excess mean
electron energy with the ion gas varies from to as the ion concentration
increases from to cm
   /
3671
theory of electric waves in inhomogeneous plasmas  dispersion functions
are derived for longitudinal waves in plasmas of variable electron
density  the special case of a quasi neutral electron beam of spatially
variable density is discussed
   /
3672
simplification of equations for the distribution function of electrons
in a plasma  an analysis based on the boltzmann kinetic equation
considering initially a spatially homogeneous plasma located in electric
and magnetic fields
   /
3673
contribution to the theory of transport processes in a plasma located
in a magnetic field  the mean statistical characteristics such as
velocity heat flow and stress tensor are determined
   /
3674
space charge field emission and the ionic condenser  high es fields
measured at the electrodes during gas discharge experiments in h
indicate that the mechanism initiating a flash of intermittent glow
is field emission from the cathode or from the negative space charge
the hypothesis is applied to the experimental results of other workers
and is confirmed  it is shown to provide simple explanations for
many gas discharge phenomena  it is suggested that the measured high
fields are due to concentrated space charges forming ionic condensers
with the electrodes or within the gas itself in the form of stationary
striations
   /
3675
statistical broadening of spectral lines emitted by ions in a plasma
   /
3676
ponderomotive force in localized plasma in the electromagnetic field
of a plane wave  a sphere of uniformly ionized gas is considered
as a rough model of localized plasma  the radius of this sphere is
smaller than the wavelength of the field in vacuum or in plasma
expressions for the internal and surface intensities of the ponderomotive
force are derived
   /
3677
excitation of plasma oscillations and growing plasma waves  report
of preliminary results of a new experiment in which the beam is modulated
by a microwave signal before it interacts with the plasma  a very
strong interaction is observed which shows essentially the theoretically
predicted form of behaviour
   /
3678
movements of rarefied plasma in an alternating magnetic field  an
expression is derived showing that even with constant current the
energy of rotation of plasma particles can increase many times in
consequence of the decrease of the radius
   /
3679
contribution to the theory of anisotropy of ferromagnetic single
crystals  a mathematical analysis based on dysons theory of spin
wave interaction is applied to the investigation of anisotropic ferromagnets
of hexagonal symmetry
   /
3680
paramagnetic resonance and polarization of nuciei in metals  a theory
of paramagnetic resonance is proposed based on simultaneous solutions
of maxwells equations and the kinetic equation for the density operator
it is shown that the polarization varies with depth and also that
the paramagnetic resonance gives rise to selective transparency in
metallic films
   /
3681
basic features of neels theory of impurity atom after effects  exposition
in simple terms of neels theory of magnetic diffusion after effects
of  the equivalent circuit of a bloch wall is derived which allows
for the influence of impurity atoms
   /
3682
two dimensional problems of the decay of magnetic fields in magnetohydrodynamic
the normal modes of decay of magnetic fields in conducting
fluids are studied for different classes of steady motion  see of
and
   /
3683
on a macroscopic measurement of the spin of electromagnetic radiation
the spin of em radiation may be deduced from the torque exerted at
microwave frequencies by a circularly polarized wave upon a screen
which can conduct current only parallel to a given direction see
of  calculations are made of the angular momentum and scattering
cross sections of the screen and the feasibility of an accurate experiment
is discussed
   /
3684
the cherenkov effect in composite isotropic media  a theoretical
investigation based on the invariance of maxwells equations  the
case of two coaxial dielectrics and permeable cylinders with a common
cylindrical interface and a charged particle moving along their common
axis is considered  results are discussed with particular reference
to cherenkov radiation at radio and microwave frequencies  the effect
of coherence on the output of the emitted radiation is outlined
   /
3685
radiation from a point charge moving uniformly along the surface
of an isotropic medium  energy emitted per unit of time by a particle
moving along a surface in a nondispersive is calculated  relativistic
conditions and for magnetic and fe expressions are derived for relativistic
and norrite type media  see also
   /
3686
diffraction by cylindrical reflectors  measurements of the near zone
diffracted field of a cylindrical reflector with a line source at
the centre agree with calculations using geometrical optics current
the equivalent line currents give slightly better agreement
   /
3687
the propagation of slow electromagnetic waves along inhomogeneous
plasma layers  on the basis of schumanns work the special case of
surface waves of the plasma and the adjoining layers of air is considered
   /
3688
molecular beam resonances in oscillatory fields of nonuniform amplitudes
and phases  the transition probability equations are reduced to forms
which are suitable for digital computer calculations  a computer
program for the calculation of the shapes of the resonances is described
   /
3689
quantum theory of galvanomagnetic effects  a study is made of the
effect of the quantization of the electron orbits in a magnetic field
on the galvanomagnetic properties of an isotropic semiconductor or
semimetal in the phonon scattering range  the conductivity tensor
is calculated using the quantum mechanical density operator  the
hall coefficient and transverse resistivity are studied for a number
of different sets of conditions for electron density magnetic field
and temperature
   /
3690
theoretical investigation of the electronic energy band structure
of solids  a review including sections dealing with the elements
of energy band theory the uses of group theory and perturbation theory
a survey or numerical methods for solving the crystal wave equation
examples illustrating complex energy band structures  a representative
list of about references is given  experimental techniques are discussed
by lax below
   /
3691
experimental investigations of the electronic band structure of solids
experiments are discussed which have been of value in contributing
to current knowledge of the band structure of many materials of importance
at present  the experiments mentioned including those involving
the de haasvan alphen effect cyclotron resonance the galvanomagnetic
effect and infrared absorption
   /
3692
electron interaction in solids general formulation  a general hamiltonian
formalism is developed to treat from first principles the motion
of electrons in solids including their mutual coulomb interaction
it is shown that under suitable circumstances plasmons the quanta
of the plasma oscillations represent a well defined elementary excitation
of the solid  the existence criterion for plasmons is found to
be a high electronic polarizability  after the plasmon modes are
separated out the remaining electron interaction is found to be screened
with a range of the order of the interelectron spacing  the usefulness
of this effective hamiltonian for the calculation of the electronic
energy levels and cohesive energy in solids is discussed briefly
   /
3693
electron interaction in solids  collective approach to the dielectric
constant  a quantum theory of the dielectric constant for solids
of both low and high polarizability is developed from first principles
in the latter case the approach used is collective in that the long
range part of the electron interaction is described by the plasmon
field  both the static and frequency dependent dielectric constant
are derived  it is shown that the interaction between electrons may
be described in terms of the dielectric constant of the solid provided
the electrons in question form a small minority group which can be
isolated from the much larger majority electron group
   /
3694
electron interaction in solids  the nature of elementary excitations
possible elementary excitations in solids are studied with the aid
of the general theoretical approach developed in the preceding papers
of this series and above  particular attention is paid to the basic
theoretical justification for the individual particle like elementary
excitation effective electrons  it is concluded that good qualitative
arguments could now be given for the existence of effective electrons
in solids  the presence of an energy gap is shown to be a necessary
condition for the existence of strong spatial correlations between
minority carriers in solids and the nature of such correlated minority
electron excitations is discussed
   /
3695
approximate theory of ferrimagnetic spin waves  the wave functions
and the energy spectrum for the spin wave problem in a normal spinel
are found by means of a straightforward extension of andersons approach
to antiferromagnetism on  only ab exchange is assumed to exist and
the calculation is carried to second order in the magnitude of the
propagation vector k  five distinct energy surfaces are found two
of which are identical in the classical limit to the ones previously
reported by h  kaplan
   /
3696
propagation of radio waves from cosmical sources  a formula is given
for the refraction of radio waves reaching the earths atmosphere
from outside  the formula may be applied to waves from artificial
earth satellites
   /
3697
a new spectral characteristic in solar radio emission  equipment
at frot davis texas covers the band and comprises a diameter parabolic
aerial with three broadband primary arrays coaxially mounted at its
focus see of april et al  a new type of last burst having a frequency
time graph in form of an inverted u and for duration is reported
and the possible origin of these bursts is discussed
   /
3698
effective magnetic meridian for cosmic rays  observations of the
cosmic ray meridian made with neutron intensity monitors at melbourne
australia are reported  doubts are expressed about the equivalent
dipole theory of the earths magnetic field see of
   /
3699
scientific observations of the artificial earth satellites and their
analysis  report of a discussion held by the royal society on
   /
3700
lifetime of an artificial russian satellite  a simple formula for
the calculation of lifetime from data on the initial orbit is given
it was applied to observations made at johannesburg of the doppler
effect on signals received at from the first russian satellite
   /
3701
interception of radio signals transmitted by the satellite sputnik
i  brief outline of apparatus and methods used some recordings of
the and transmissions obtained in florence are reproduced
   /
3702
observations in australia of radio transmissions from the first artificial
earth satellite  observations of the strength of and signals
were made at bringelly near sydney australia  the rate of fading
appears to be a minimum when the direction of propagation of the
wave is nearly perpendicular to the earths magnetic field
   /
3703
ionospheric drift in the f region near the magnetic equator  graphs
of the diurnal variations of drift in the f layer based on observations
made at singapore from september to august suggest that the drift
is predominantly in an ew direction and has a maximum value of about
   /
3704
artificial aurora  the luxembourg effect is explained and the possibility
of using it to produce a luminous discharge in the e layer is
discussed
   /
3705
determination of auroral height by radar  preliminary report of observations
made during the igy at a radar station erected at above sea
level at bluff in the south island of new zealand  echoes have been
recorded at from heights of about km and ranges up to about km to
the south
   /
3706
atmospheric radio noise
   /
3707
a note on the evaluation of the response of a nonlinear element to
sinusoidal and random signals  a method is developed based upon a
mathematical technique described by lewis which is particularly useful
for the analysis of nonlinear control systems  simple cursors may
be constructed to determine the effective gain of the nonlinear unit
the application to hysteretic nonlinearities and the response to
random signals is illustrated
   /
3708
statistical design theory for strictly digital sampled data systems
present design theories are based on system response to inputs of
known shape and little attention is given to situations in which
only the statistical properties of the inputs are known  the basis
of a statistical design theory is presented and applied to the optimum
design of a strictly digital system  the new theory forms a close
parallel to wieners theory of optimum filtering and prediction and
its various manifestations in applications to continuous feedback
control systems
   /
3709
a correlation between the transient and frequency responses in servomechanisms
statistical evidence is used to relate time and frequency
response parameters  these empirical relations together with a new
theoretical relation for the delay time enable the step response
to be sketched given the open loop response  some nontypical closed
loop responses may be broken down into two subtransient step responses
which are separately determinable
   /
3710
fundamental equations for the application of statistical techniques
to feedback control systems
   /
3711
direct drive amplifier for two speed servos  a five transistor servo
amplifier drives a standard motor without using an output transformer
for a two speed system the amplifier contains a switching circuit
incorporating zener diodes and a three stage feedback network
   /
3712
automatic power plant for telecommunications installations  the development
of multichannel radio telephone services capable of unattended
operation for long periods has led to the need for automatic generators
of electric power  some of the factors in the design of diesel power
plants are considered  both mains standby and dual alternator systems
are discussed
   /
3713
hot transformers  brief note on two experimental types of transformer
designed for operation at c  one housed in an evacuated stainless
steel case is rated at the other is of open construction with a nominal
rating of at
   /
3714
magnetic inverter uses tubes or transistors  a means of producing
ac from dc  the collector and emitter coil windings of the on transistor
of a multivibrator are differentially connected across the input
voltage so that the drive winding partially determines the frequency
of oscillation
   /
3715
simulation of nonlinear field problems  some three dimensional problems
can be solved by using a resistance network in conjunction with a
single ac amplifier a function generator a scanning switch and a
number of simple analogue storage units
   /
3716
matrix analysis of logical networks  a novel method of matrix algebra
is derived for the analysis of networks representing logical systems
too complex for conventional approaches using boolean algebra  it
is shown that truth tables of system blocks may be treated as matrices
and that logical operations on such matrices can be performed efficiently
   /
3717
an analogue computer for fourier transforms
   /
3718
analogue computers in the nuclear power programme
   /
3719
new applications of impedance networks as analogue computers for
electronic space charge and for semiconductor diffusion problems
the general second order partial differential equation is transformed
to the equivalent equation of finite differences and hence relations
for analogue impedance networks are derived  resistance chains are
applied to the case of one dimensional high vacuum diodes yielding
results within about of the exact solutions  rc networks are applied
to semiconductor diffusion with space and surface recombination giving
some new results for pn diodes  a plane resistance network applied
to a triode with space charge gices the anode current grid voltage
curve within a few per cent of the published value  see also of may
   /
3720
a basic transistor circuit for the construction of digital computing
systems  a circuit comprising one transistor one capacitor and three
resistors forms the basis of a complete digital computing system
for use where high operation speed is not essential  the construction
of well known computer circuits from the basic circuit is described
and a complete logical computing system using circuits is developed
to demonstrate their application
   /
3721
printed wiring  an assessment and detailed description of processes
in the production of photo etched circuits  the properties of the
copper foil used are examined and particular attention is paid to
the photographic and enamelling techniques and to dip soldering
   /
3722
small transformers with low magnetic leakage  the external field
characteristics of various types of laminated and c core transformers
are examined to determine the form of construction with lowest leakage
   /
3723
wide band transformer characteristics  a parameter is defined for
wide band transformers which represents the series resonance of the
leakage inductance and the primary and secondary stray capacitances
it is shown that this parameter may be determined from the low frequency
requirements on the transformer and then used as a guide to the attainable
high frequency response
   /
3724
terminal properties of magnetic cores  the terminal properties of
the cores can be obtained from their dynamic step response it is
shown that for thick mils or more thin mil and intermediate sized
cores there is a unique relation between the flux in the core and
the applied coulomb turns  the analysis is verified by experiment
   /
3725
new techniques for winding subminiature coils  details of a method
for winding self supporting coils of adhesive coated wire
   /
3726
solid state thyratron switches kilowatts  the opation of a controlled
silicon rectifier and its application in various switching circuits
and converters are described
   /
3727
broad band balanced duplexers
   /
3728
research of condensers and its results  voltage temperature and frequency
characteristics are given for a number of types of capacitor particularly
the batio and silvered mica types
   /
3729
accelerated life testing of capacitors
   /
3730
precision variable capacitors for high grade electronic equipment
two types of small variable capacitor are described which were designed
to meet stability and accuracy specifications comparable with larger
types  one gives a linear frequency variation over of shaft rotation
the other gives a sinusoidal variation of frequency about a mean
value as the rotor shaft is turned continuously
   /
3731
excitation of higher order modes in spherical cavities
   /
3732
some general properties of nonlinear elements part small signal theory
the analysis of nonlinear capacitor modulators demodulators and negative
conductance amplifiers with only two signal frequencies present gives
results that agree with the general energy relations of part of
in addition the gain bandwidth terminal admittances and sensitivity
to changes in terminal admittances or in local oscillator drive are
given together with their dependence upon the amount of nonlinearity
generally the bandwidth of these devices approaches zero as the nonlinearity
approaches zero
   /
3733
general properties of frequency converting networks  a generalized
analysis of frequency converting systems consisting of networks containing
nonlinear inductors capacitors and resistors and including also
nonlinear l c and r coupling elements  the mesh and nodal equations
for a general nonlinear network are given and it is assumed that
a certain high voltage and current distribution the so called fundamental
state results from the presence of carrier current and voltage
sources  first order perturbational equations are then derived corresponding
to the disturbance of the disturbance of the fundamental state
by small signal voltage or current sources  linear differential equations
with time dependent coefficients are obtained which yield for
a periodic fundamental state equations in matrix form  methods of
simplifying the matrices are shown and the method is used to examine
stability conversion gain and loss  an example a polyphase magnetic
modulator is analysed
   /
3734
parallel four terminal networks  a simple relation exists between
the output input voltage ratio for any number of four terminal networks
in parallel and their parameters of output admittance and short circuit
transfer admittance  the relation enables the voltage ratio to be
stated without solving the networks
   /
3735
a wide band multiplier unit  capacitive coupling leads to easily
adjustable wide band couplers  a practical design of a wide band
frequency multiplier unit incorporating these and covering all bands
from to is given
   /
3736
ceremic if filters match transistors  resonant filters can replace
if transformers with improvement in size cost ruggedness and insertion
loss  their input and output impedances are compatible with those
of transistors
   /
3737
transient phenomena in band filters  analysis of a filter consisting
of two coupled circuits
   /
3738
simultaneous asynchronous oscillations in class c oscillators  it
is shown theoretically and practically that self starting asynchronous
oscillations are possible in a class c pentode oscillator  transient
and steady state solutions are obtained for such an oscillator with
one and two degrees of freedom
   /
3739
shf frequency standard uses double conversion
   /
3740
simultaneous oscillations at two frequencies in a self oscillatory
system with automatic bias  an investigation of the self biasing
by grid current in an oscillator confirms that oscillations at two
different frequencies may occur  see also of may
   /
3741
an atomic reference oscillator
   /
3742
frequency stabilization of a microwave oscillator with an external
cavity
   /
3743
multivibrator circuit for millimicrosecond pulses  pulse rise times
of about and a repetition frequency of several can be achieved with
the value circuit described  pulse width can be adjusted continuously
without affecting the rise time
   /
3744
precision pulse generator
   /
3745
dekatrons and electromechnical registers operated by transistors
transistor circuits are described for driving cold cathode decade
tubes and electromechanical counters  in both cases the transistor
circuit combines the waveform shaping properties of the thermionic
valve with the economy of power achieved with the cold cathode valve
high reliability of performance is also attained
   /
3746
magnetic core dividers for itv sync generators  an accurate and stable
digital divider can be made with a pair of magnetic cores having
rectangular hysteresis loops  division by factors up to has been
obtained in a single stage in the frequency range
   /
3747
on the problem of synthesis of amplifier circuits  a new mathematical
method is described for the analysis of transients in amplifiers
and a means of synthesis is suggested for multistage systems considering
different types of distortion
   /
3748
design of conditionally stable feedback systems  conditionally stable
systems are shown to have a greater feedback than that obtainable
from unconditionally stable feedback circuits  the design of such
systems is analysed mathematically and a practical method for automatically
preventing oscillation occurring in them is suggested  experimental
results obtained with a suitable circuit are presented
   /
3749
some aspects of half wave magnetic amplifiers  the performance of
half wave magnetic amplifiers is analysed and a theory presented
which allows for a finite control circuit resistance or rectifier
reverse conductance and imperfect core properties  experimental results
obtained with amplifiers using different cores show good agreement
with theory  various methods of bias are reviewed and a conductance
controlled amplifier is described
   /
3750
a fast response full wave magnetic amplifier
   /
3751
the effective feedback factor of self balancing magnetic amplifiers
   /
3752
three output immittance theorems  a discussion of various theorems
having practical application in the analysis of transistor circuits
   /
3753
nonlinear distortion in transistor amplifiers  following an analysis
of the causes of distortion in common emitter circuits the distortion
factor is derived from the static characteristics  the dependence
of distortion on temperature collector bias input signal level and
load resistance is determined and calculated values are compared
with results of measurements
   /
3754
some transistor input stages for high gain dc amplifiers  several
types of input stage are investigated and methods of reducing drift
are suggested  it is shown that drift of operating point in transistor
dc amplifiers depends on the type of circuit the lowest drift being
obtained using the transistor as a chopper
   /
3755
a transistor high gain chopper type dc amplifier  a modulated system
is employed consisting of a transistor input chopper a high gain
transistor ac amplifier and an output chopper  the system has an
open loop gain of with a band extending from direct current to  peak
output is and current drift referred to input is in the range  the
voltage drift at the input is less than
   /
3756
designing transistor af power amplifiers  the amplifier described
delivers to a load  it contains a driver stage a phase splitter using
a transistor pair and a push pull output stage
   /
3757
operation of a solid state quantum mechanical amplifier  the operation
of an s band solid state quantum mechanical amplifier operated at
with a computed noise temperature of less than is compared with similar
devices and is used as proof of the condition of discrete phonon
saturation which has been previously postulated  see also of june
   /
3758
the solid state maser a supercooled amplifier  a review of maser
techniques with descriptions of two level molecular beam and three
level solid state devices  amplifier and oscillator characteristics
noise measurements and future developments are discussed
   /
3759
a uhf solid state maser  maser action at a frequency of has been
obtained by using a cavity mode at the pumping frequency and a lumped
resonant circuit at the amplifying frequency
   /
3760
design considerations for circulator maser systems  a general expression
for effective maser system noise temperature is calculated and a
working approximation is derived  the noise and stability requirements
for a low noise circulator maser system are given in terms of maser
gain and of dissipative losses and swr in various parts of the system
   /
3761
system noise measurement of a solid state maser  a complete amplifier
system with an effective input noise temperature of is described
the sources of noise are analysed and it is shown that the noise
temperature of the maser proper is close to the theoretical value
   /
3762
electron spin and phonon equilibrium in masers
   /
3763
a travelling wave parametric amplifier  a lossless transmission line
with periodically varying distributed inductance and a constant distributed
capacitance will support a growing current wave  for maximum
amplification the oscillator used for providing the periodic variation
of inductance must be synchronized with the incoming signal  the
noise figure of such an amplifier should be very favourable  an experimental
investigation is in progress and related schemes are being
studied in which precise frequency and phase relations are not demanded
   /
3764
proposed negative mass microwave amplifier  it is pointed out that
negative masses occur in semiconductors at energies close to the
band edge if the energy contours are reentrant there  it is suggested
that such a semiconductor might be used as the active element in
a microwave amplifier although preliminary experiments with germanium
did not show the effect  see also of
   /
3765
on chandrasekhars theory of turbulence  the theory has been generalized
to the case of axisymmetric turbulence and eight differential equations
in eight defining scalars of double and triple correlation tensors
deduced  two of these equations replace that of de karman and howarth
in the theory of isotropic turbulence
   /
3766
on decay of energy spectrum of isotropic turbulence
   /
3767
electric field distribution in polarized photoconductors  the distribution
is determined from changes which occur in the persistent polarization
see of under various polarizing conditions
   /
3768
the fundamental state of an electron gas  detailed discussion with
reference to mayers treatment of electron correlation energy
   /
3769
force densities in dielectrics  a new approach to the theory of electrical
conductivity of solids  since the electrical conductance of a
body is a measure of the fluctuations of charge in a state of thermodynamic
equilibrium an analysis of these fluctuations gives the value
of the conductivity  the value derived agrees with that of drude
but is found to be half that for the lorentz sommerfeld model
   /
3770
the boltzmann equation in the theory of electrical conduction in
metals  the boltzmann equation for electrical conduction in metals
is derived assuming where is the collision time  an expression independent
of this assumption is considered but not evaluated
   /
3771
theory of electrical conductivity of anisotropic inhomogeneous media
   /
3772
quantum theory of the electrical conductivity of metals in a magnetic
field  the kinetic equation for the density matrix is derived and
the asymptotic values of the kinetic coefficients in a strong magnetic
field are analysed
   /
3773
on the theory of spectral line broadening in plasma
   /
3774
structure of shock waves in a plasma  investigation of a shock wave
in a plasma taking account of the difference in electron and ion
temperatures  three cases are examined nonstationary shock wave stationary
shock wave in a strong magnetic field
   /
3775
electrodynamical acceleration of plasma bunches  a method is described
of generating a gas discharge plasma by the electric explosion of
a mm diameter copper wire in a discharge chamber evacuated to mm
hg  a capacitor is used with initial voltage
   /
3776
quantum kinetic equation for plasma taking account of correlation
a quantum kinetic equation for a system of particles with coulomb
interaction is derived taking into account the correlation of the
mutual position of the charged particles
   /
3777
on the effective field in a plasma  equations for the partial distribution
functions are used to compute the effective field acting on charged
particles in a plasma  the effective field differs from the mean
field by a small quantity of the order of where n is the number of
particles within a sphere of radius equal to the debye radius
   /
3778
the dispersion equation for plasma waves  the validity of different
formulae is discussed  when collisions are infrequent no dispersion
equation exists except in special cases  see also of
   /
3779
on the dynamics of a bounded plasma in an external field  an investigation
of the dynamics of a quasi neutral plasma formation located in
the field of a plane em wave  the method of successive approximations
is used  within the limits of the assumptions of the analysis a plasma
bunch tends to spread out
   /
3780
an energy principle for hydromagnetic stability problems  the problem
of the stability of static highly conducting fully ionized plasmas
is investigated by means of an energy principle developed from one
introduced by lundquist of  the method is applied to the general
axisymmetric system and to plasmas which are completely separated
from the magnetic field by an interface
   /
3781
radiation of plasma in a magnetic field  mathematical analysis of
em radiation in plasma taking account of electron spin in a uniform
magnetic field
   /
3782
coherent scattering and radiation of electromagnetic waves by plasma
in an inhomogeneous magnetic field  the propagation of quasi plane
waves in a waveguide filled with plasma in a longitudinal magnetic
field and the radiation in an electron plasma of a bunch which travels
through a spatially periodic axially symmetric magnetic field are
discussed  the plasma tends to focus the bunches and a longitudinal
focusing effect results from the attraction between the induced currents
flowing in the same direction
   /
3783
models demonstrating the phenomena of ferromagnetic hysteresis  extension
and refinement of the preisach model  see also of
   /
3784
contribution to the phenomenological theory of paramagnetic relaxation
in parallel fields  the role of spin lattice interaction is examined
and the applicability of the results of this analysis to paramagnetic
absorption at high frequencies and temperatures of the order of is
considered
   /
3785
the classical electromagnetic equations expressed as complex four
dimensional quantities  it is possible to compress the classical
em equations into three complex four dimensional quantities representing
respectively em field currents and charges and vector and scalar
potentials  this notation is useful in problems relating to waveguides
cavities and aerials for microwaves
   /
3786
theory of magnetohydrodynamic waves using the energy pulse tensor
of abraham
   /
3787
dynamo effect in magnetohydrodynamic theory
   /
3788
surface currents induced by short wavelength radiation  the integral
equation given by fock of for the surface currents induced in a perfectly
conducting convex object by short wave length plane electromagnetic
waves is solved directly by the method of fourier transforms  the
result agrees with focks indirect approach  some general properties
of the equation are also discussed
   /
3789
the cherenkov effect produced by single particles in gases  the application
of photo multipliers for detecting cherenkov radiation is discussed
and successful experimental work is reported
   /
3790
a new formulation of scalar diffraction theory for restricted aperture
   /
3791
radiation of charged particles in flight past ideally conducting
bodies  the problem is discussed in the nonrelativistic approximation
and the induced charge and currents are calculated initially without
considering retardation  the radiation due to the current system
determined is then estimated  the dipole approximation is used to
derive expressions for the rate at which energy is radiated  the
radiation resistance for a waveguide system is calculated and its
dependence on the particle velocity and on the radius wavelength
ratio is shown graphically
   /
3792
stark effect at and millimetres wavelength nitric oxide  stark effect
measurements have been made for the first time in the mm wave region
results of stark effect measurements on the and transitions of the
ground state of falling at and mm respectively are reported and are
shown to fit closely existing theory the electric dipole moment of
no in the ground state is found to be debye unit
   /
3793
electric susceptibility of ethyl chloride in the centimetre region
results of measurements at over a pressure range and a temperature
range are discussed  see also of and
   /
3794
electron spin and phonon equilibrium in masers  it is pointed out
that the successful operation of in three level steady state masers
is incompatible regardless of the operating frequencies of the maser
with the assumption that the relaxation rates are determined by the
interaction between the lattice vibrations and the helium bath
   /
3795
identity of spin temperature and thermodynamic temperature
   /
3796
generalized mobility theory  a formal theory of mobility is presented
that does not depend on the existence of a transport equation  in
particular the hamiltonian describing the electron plus the scattering
system is not decomposed into an unperturbed part plus a perturbation
only the applied field is treated as small  the result is shown to
reduce to the usual transport result when the scattering perturbation
is weak without assuming the existence of a relaxation time  the
relation between a many electron treatment and the one electron treatment
is demonstrated for the case of fermi as well as boltzmann statistics
   /
3797
the band theory of metals  brief report of a conference held at the
physical society at imperial college london december  some papers
are noted
   /
3798
a lunar radio interferometer  in a two aerial interferometer used
in radio astronomy one of the aerials can be replaced by the surface
of the sea  in the instrument described the ionosphere of the moon
is used in place of the second aerial  with metre wavelengths the
minimum angle of refraction of the lunar ionosphere is found to be
of the order of
   /
3799
radio interference phenomena due to the ionosphere of the moon  an
attempt to explain the increase of solar radio emission observed
before and after a solar eclipse by interference effects due to refraction
of radio waves in the lunar ionosphere
   /
3800
a remarkable solar radio event  increased solar radio noise at a
frequency of was recorded at nera observatory netherlands from on
november  the maximum value was approximately times the noise level
of the quiet sun  fluctuations with a period of occurred and are
attributed to solar phenomena
   /
3801
a radio image of the sun on wavelength  in june at a station of the
physical institute in the crimea a new stationary radio telescope
with a parabolic reflector of diameter was put into commission  isophotes
of the sun obtained at and are shown
   /
3802
energy spectrum of cosmic radiation  a theory is given for the observed
spectrum const where for a wide range of values of momentum
   /
3803
diurnal variations in the number of shower meteors detected by the
forward scattering of radio waves ellipsoidal theory  the ellipsoidal
geometry inherent in the forward scatter process is developed fully
the more rigorous results obtained are compared at various stages
in the analysis with those given by the simplifying cylindrical approximation
developed in part  the potentially observable trails are first
located and their distribution determined  the fraction of these
providing a signal exceeding some given level is found and the total
number of these observable trails as a function of trail orientation
is determined by integrating over the spatial distribution  part
   /
3804
resonance effects in the theory of meteor observability  the observability
theory for forward scattering and revised to cover the resonance
that occurs when there is a component of the incident electric vector
transverse to the axis of the meteor trail  normalized contours are
given
   /
3805
solar activity and cosmic radiation  experimental observations of
cosmic radiation during intense solar activity are presented and
examined with particular attention to the period around the solar
flare of february  the results obtained are discussed in relation
to models of solar activity involving corpuscular streams
   /
3806
on the asymmetry of the heliographic distribution of the storm producing
probability of flares  the probability is greatest for flares near
the centre of the disk and for those in the ne and sw quadrants
the greater probability for flares in the western hemisphere is not
statistically significant
   /
3807
the distribution over the emitting area of x radiation from the solar
corona and the residual intensity during total solar eclipses  the
e layer is assumed to be ionized by xrays of approximate wavelength
a  the intensity of coronal radiation in this waveband is calculated
and the results lead to a considerable degree of limb brightening
and to emission of radiation at radii greater than that of the visible
disk  the intensity of the residual radiation during total eclipses
can be calculated and is estimated to have been about in and and
about in
   /
3808
magnetic activity following a solar flare  the conclusions reached
by watson of that solar flares and increases of magnetic activity
are not correlated is not correct  when the magnitude of the flare
and its position on the disk are taken into account there is a positive
correlation as was shown by newton see eg of and
   /
3809
international geophysical year  a report on the us program with a
brief account of some of the activities during the first five months
   /
3810
estimating the life of a satellite
   /
3811
lifetime of an artificial earth satellite  the approximate formulae
given by fejer and scott are compared with those given by a more
exact method and found to be accurate provided the eccentricity is
not large
   /
3812
british radio observation of the satellite  brief reports of the
observations made on the first russian satellite at the bbc station
tatsfield the radio research station slough and ministry of supply
establishments are given  these include measurements of the signal
characteristics field strength doppler frequency shift and bearing
and elevation of the satellite
   /
3813
the effect of diffusion on the vertical distribution of ionization
in a quiet f region  electrons are assumed to disappear by attachment
to neutral molecules and by diffusion  the coefficient of attachment
is assumed to be constant while the diffusion constant is calculated
according to classical theory  using rocket measurements of air density
and temperature the vertical distribution of electrons can be calculated
the results are at variance with those actually observed possibly
because the diffusion constant is much less than that assumed
   /
3814
ambipolar diffusion in the f layer  diffusion in the f layer probably
depends on the diffusion of in the coefficient is estimated to be
about one quarter of the value normally assumed to be applicable
in the f layer
   /
3815
horizontal wind systems in the ionospheric e region deduced from
the dynamo theory of the geomagnetic variation  wind systems are
deduced from sq data for the solstice seasons in both northern and
southern hemispheres and the diurnal and semi diurnal components
are examined  a comparison of the theoretical system with observed
winds is made  wind velocities are calculated taking account of coriolis
forces and assuming the electron density at night to be that at noon
parts
   /
3816
non chapman like variations in the ionospheric e and f layers  effect
of the sq current system  part  variations in e and f are examined
in various months in addition to those of march which have already
been discussed see of and  it is shown that in non equinoctial months
e is larger in the winter hemisphere than in the summer hemisphere
for the same solar zenith distance  this unsymmetrical distribution
is interpreted as being due to the sq current system effect in the
e layer the sq current system developing more strongly in summer
than in winter  somewhat similar results are observed for the f layer
but detailed examination shows that they can be explained by the
temperature difference between the summer and winter hemispheres
   /
3817
radio star scintillations at an equatorial station  scintillation
of radio stars has been measured at in ghana for four years  it is
unusually intense occurs only at night and is correlated with spread
echoes from the f layer and with equatorial scatter of radio signals
near sunspot maximum
   /
3818
the diurnal and seasonal variations of spread f ionospheric echoes
and the scintillations of a radio star  the degree of spreading is
greater at inverness than at slough but the diurnal and seasonal
variations are similar and can be correlated with the scintillations
of the radio star in cassiopeia provided an allowance is made for
the zenith angle of the star  see also of june
   /
3819
a method of determining the correlation between f and sunspot number
the monthly median critical frequency and the smoothed sunspot number
r can be represented for a month m and time of day by  the continuous
periodic functions a and b are examined using data obtained at six
places in japan
   /
3820
solar activity and the ionosphere  observations at slough showed
that the intensity of the ultraviolet and x radiation responsible
for the existence of the e layer of the ionosphere was higher in
september october and november than ever before recorded and that
on individual days in november the critical frequency of the f layer
at noon was above  see also of april
   /
3821
disturbances of the ionospheric f region associated with geomagnetic
storms part auroral latitudes results of a statistical treatment
show that the deviation of f on a disturbed day is similar to the
negative disturbance in middle latitudes see part of january the
deviation of is different  main features of the f disturbances can
be accounted for by vertical electron drift
   /
3822
electron density fluctuations and scattering of radio waves in the
ionosphere  discussion of theoretical and experimental determinations
of electron density fluctuations and of energy scattered at vhf indicates
that in vertical incidence soundings at frequencies below the
critical frequency the scattered field is chiefly due to waves first
scattered in the forward direction and then reflected from higher
levels in the ionosphere
   /
3823
control of the ionosphere by means of radio waves  a note on the
possibility of using radio waves near the gyrofrequency of electrons
in the ionosphere to control the electron temperature and hence the
rates of diffusion attachment and recombination
   /
3824
an artificial ionosphere  the release from rockets of potassium into
the high atmosphere produces an ionized cloud lasting for about an
hour suitable for returning microwave signals
   /
3825
waveform studies of electric field changes during cloud to cloud
lightning discharges  assuming that cloud to cloud discharges may
be identified from the sign of the field change and the time separation
of the individual strokes such discharges exhibit all the features
known to be associated with ground discharges  they include precursors
multiple strokes return strokes slow field changes and hook components
junction field changes between strokes
   /
3826
auroral display observed from unusually low geomagnetic latitudes
observations of the aurora display of september are reported with
brief details of some related effects
   /
3827
horizontal movements of aurora  the drift of auroral forms has been
measured at three stations in canada south of the auroral zone  no
evidence is found of a motion due to the earths rotation relative
to a fixed point in space  the distribution and magnitude of the
drift speeds parallel and normal to the geomagnetic meridians are
similar to those found for ionospheric drifts  the drifts speeds
increase with geomagnetic activity particularly in an ew direction
   /
3828
a continuously recording automatic auroral radar  a low power system
with fixed aerials is used to give a continuous photographic record
the echo intensity is also integrated electronically to give a chart
record which is immediately available
   /
3829
abnormal polarization of the atmospheric pulses reflected successively
from the ionosphere  elliptic patterns of gradually decreasing eccentricity
and tilt angle have been observed in cathode ray direction finders
used to record atmospherics due to lightning discharges at a distance
of about
   /
3830
electromagnetic radiation from lightning strokes  a theory is given
of the spectral distribution and the amount of vlf radiation emitted
from a vertical lightning stroke from cloud to ground  the radiated
energy has a maximum intensity at about and a total width at half
maximum of  the total energy radiated in one leader and return stroke
is estimated to be about joules
   /
3831
atmospheric radio noise at frequencies between and  the results are
described in terms of a voltage envelope at the output of a narrow
band receiver between points  the rms voltage deduced by integrating
the measured amplitude distributions varies between four and eight
times the average voltage  the noise is always much more impulsive
than fluctuation noise  the structure of the voltage envelope is
considered in two ways  the amplitude distribution of pulse peaks
and the amplitude distribution of voltage  see also of
   /
3832
variable output mains transformer  a design using eight windings
giving voltages produces any integral output voltage between and
by simple switching  auto transformer operation above extends the
range to v
   /
3833
voltage conversion with transistor switches  the conversion of a
dc voltage to ac at high audio frequencies at powers of is achieved
using a circuit containing transistors and modern magnetic core components
   /
3834
failure rate studies on silicon rectifiers  a study of the failure
rate of rectifiers rated at peak inverse volts under various conditions
average failure rates for the type are approximately three times
those for the type under identical conditions
   /
3835
transistor filters ripple  in a low voltage dc power supply a capacitance
of is effectively multiplied by by the addition of a junction
transistor operating as an impedance transformer
   /
3836
magnetic voltage stabilizers  the use of saturation effects in a
number of basic designs is described brief details of a valve controlled
automatic stabilizer circuit are given
   /
3837
a survey of delay lines for digital pattern storage  a review of
em and ultrasonic delay lines for use over a wide range of delay
times  wire type acoustic delay lines using magnetostrictive transducers
acoustic lines using liquids or solids as delay media and both the
continuous and lumped parameter types of em delay line are examined
   /
3838
modern trends in analogue computation
   /
3839
a special analogue computer for calculating the oscillations of diaphragms
   /
3840
passive components for submarine telephone cable repeaters  the design
and inspection of inductors and transformers are briefly described
details of the inspection of silvered mica capacitors are given as
an example of the procedure adopted
   /
3841
nomogram for air gap design  a nomogram is given for determining
the relation between the actual air gap in a choke or transformer
and its effective value for normal types of laminations  thermistors
a review is given of the various types of thermistor their method
of manufacture and the physical theory of their operation  some typical
applications are outlined
   /
3842
saturable reactors fire radar magnetrons  magnetic modulator uses
saturable reactors to convert input sine wave into narrow high peak
power output pulses  basic action of current pulse compression with
magnetic modulators is explained  polarizating and differentiating
circuits  delay line wave shaping pulse permeability measurements
cancellation effects and related features leading to improved design
are discussed
   /
3843
a multichannel dekatron scaling unit  equipment is described for
counting simultaneously in up to six channels  a variety of counting
rates can be obtained
   /
3844
the duroplast capacitor  a tubular paper capacitor impregnated with
epoxy resin which eliminates the need of a sealed metal can  constructional
and electrical data are given
   /
3845
thermal fluctuations in a nonlinear system  an electric circuit containing
a voltage dependent resistance and a capacitance is studied
a general method is given for finding the spectral density of current
fluctuations and explicit results are obtained for two special forms
of rv
   /
3846
a numerical method for the determination of a two pole function which
approximates a given complex function in a band of real frequencies
   /
3847
on the theory of anisotropic obstacles in cavities  variational expressions
are derived for the resonance frequencies of a cavity containing
a material with tensor electromagnetic properties
   /
3848
circularly polarized microwave cavity filters
   /
3849
synthesis of driving point and transfer functions by continued fraction
expansion  a method of synthesis of driving point functions has been
developed in which more than one network element may be included
in each branch of the ladder network  the method is first applied
to rl and lc two element type networks and then extended to the general
rlc network  four terminal networks having prescribed driving point
and transfer impedances are synthesized in a similar manner
   /
3850
the unbalanced symmetrical parallel t network taking account of condenser
loss  the network is analysed without adopting the usual approximations
and its application to wave analyser and oscillator circuits
is discussed  see of
   /
3851
synthesis of a class of microwave filters
   /
3852
bifilar t trap  details are given of a circuit with a bifilar t trap
designed for rejecting the second harmonic of a signal in an infrared
detector amplifier  other applications of the bifilar t trap are
considered eg a tuned af amplifier having a bandwidth of a few hundred
cycles with a narrow band of high attenuation at the centre and a
narrow band feedback amplifier
   /
3853
production of millimetre waves by a spark generator  a brief account
of experiments which suggest that the spark generator does not offer
a practical means of extending the radio spectrum to wavelengths
less than mm
   /
3854
circuits for forming pulses from a sinusoidal voltage using a relatively
low supply voltage  circuits are considered which have a number of
advantages over multivibrator and trigger circuits  valve transistor
or hybrid circuits can be used
   /
3855
the schmitt multivibrator  a detailed design procedure is given and
applications of the circuit are outlined
   /
3856
a method for sharpening the output waveform of junction transistor
multivibrator circuits  a method of designing the circuit to reduce
the recharging time of the coupling capacitor is given  an improvement
in waveform at the collector of one transistor is achieved with an
accompanying deterioration of the other output
   /
3857
design of a dual pulse code train generator  description of a pulse
train generator developed for delay line testing which provides a
double train of pulses of variable separation
   /
3858
transistor oscillators and their load independent properties  the
equivalence of the internal and the external feedback in a transistor
oscillator circuit is established  two types of load independent
oscillator are considered one with a load impedance in parallel with
the equivalent passive quadripole and the other with the impedance
in series  the conditions for obtaining an oscillator with two load
independent impedances and a load independent oscillator in the form
of a six terminal network are examined  see also of
   /
3859
experimental and theoretical investigation of a frequency stabilized
transistor oscillator for  the condition for oscillation of a feedback
oscillator is derived  the amplifier its load and the feedback network
are treated as a single cascaded quadripole  output voltage and frequency
variations as a function of temperature load and supply voltage
were measured on a practical circuit containing a quartz crystal
resonator  a general rule for adjusting the emitter series resistance
so that the input parameters remain constant during variations of
temperature could not be established
   /
3860
designing transistor circuits sinusoidal transistor oscillators
a criterion for the generation of a single sinusoidal waveform is
developed from linear network theory and applied to basic transistor
oscillator circuits  practical problems of distortion are discussed
   /
3861
designing transistor circuits small signal parameters and equivalent
circuits  the merits of various equivalent circuits for transistors
are discussed with emphasis on the common base derived y h and t
arrangements
   /
3862
performance of three millimetre harmonic generators and crystal detectors
   /
3863
a method for investigating amplifying circuits with characteristic
equations of the third degree for short build up times  a method
is proposed in which a number of difficulties in design are eliminated
as an example results are given of an investigation of a correction
circuit using an inductance in the grid circuit
   /
3864
squelch circuit mutes magnetic tape echoes  a biased diode type of
avc is described which eliminates echoes due to print through effect
by rejecting outputs lower than below peak signal level
   /
3865
the cathoguard  a method of reducing the input and output capacitances
of a wide band pulse amplifier is described
   /
3866
the asymmetry of two circuit tuned and coupled filters due to feedback
via the grid anode capacitance  the asymmetry due to feedback in
the characteristics of an if amplifier is calculated for a circuit
with tuned filters and for coupled filters  the limiting conditions
for instability are also determined  see also below
   /
3867
transistor q multiplier for audio frequencies  the use of positive
feedback to increase the selectivity of a tuned circuit is discussed
the performance of a practical circuit giving for example a q of
at is described
   /
3868
transistor ac amplifier uses multiple feedback  the use of shunt
and series negative feedback loops simultaneously in each stage is
considered
   /
3869
a sensitive superconducting chopper amplifier  an amplifier based
on a magnetically modulated wire and similar in principle to that
due to templeton is described  it is designed for the study of thermoelectricity
at liquid he temperatures
   /
3870
centimetre solid state maser  a three level solid state maser using
doped with has been operated as an amplifier at  the design is somewhat
different from that previously reported of july which operates in
the same frequency range
   /
3871
two level solid state maser  microwave amplification and oscillation
have been observed at using two level electron spin systems  the materials
used were single crystals of quartz and of magnesium oxide each
containing paramagnetic defects
   /
3872
maser oscillator with one beam through two cavities  the behaviour
is investigated using a geometrical representation of the schrodinger
equation and a qualitative explanation is given of the ability of
the maser to oscillate simultaneously at two frequencies
   /
3873
a low noise wide band reactance amplifier
   /
3874
circuit analogues of suhl type masers  a tuned circuit in which inductance
varies with time and two coupled tuned circuits in which mutual
inductance varies with time are analysed and shown to act as amplifiers
under certain conditions  these considerations are preliminary steps
to the final problem leading to the suhl type maser see also of
   /
3875
amplification using a precessing magnetic moment  an account is given
of the analysis of an arrangement in which two tuned circuits are
coupled to a precessing magnetic moment  it is shown that with where
and are the resonance frequencies of the circuits and the precession
frequency useful amplification can be obtained  in the course of
the analysis the bloch equations are solved to a higher order in
approximation than is usual  parametric amplification of the fast
electron wave
   /
3876
experimental characteristics of a microwave parametric amplifier
using a semiconductor diode  a rectangular cavity simultaneously
resonant at and is used with a ge junction diode having a zero bias
capacitance of and a spreading resistance of  with a pumping signal
applied at  amplification can be obtained at either of the lower
frequencies  at gain preliminary measurements show a noise figure
less than db
   /
3877
noise figure measurements on two types of variable reactance amplifiers
using semiconductor diodes  the use of semiconductor diodes in an
up converter and in a negative resistance amplifier at is described
a bandwidth of was obtained with the latter at a maximum gain of
and a noise figure as low as has been achieved
   /
3878
an experimental investigation of the method for obtaining an optimum
amplitude phase modulation  a report on experiments confirming the
main premises of the theory of the method proposed by tetelbaum see
   /
3879
balanced modulators based on the hall effect in semiconductors  balanced
modulators based on the hall effect in and n type ge are investigated
sensitivities are too low for practical use
   /
3880
a phase sensitive detector  a detailed circuit is given of a system
for measuring the voltage swr in a waveguide by detecting a modulated
carrier  by using a very narrow effective bandwidth detection is
possible at signals levels as low as
   /
3881
analysis of transient processes in diode detection by a method based
on the use of low frequency equivalent circuits  a method is proposed
for analysing the transient processes in a system consisting of a
hf amplifier and a diode detector  the method is based on the linear
approximation of the processes occurring during detection and on
the replacement of the detector and of the amplifier circuits by
equivalent lf circuits  various types of circuits and various shapes
of the envelopes of the input signal are considered
   /
3882
the distortion of frequency modulated oscillations due to asymmetry
in two circuit filter networks  second and third order distortion
factors for quasi static and dynamic distortion conditions are calculated
using formulae derived from a series expansion of the filter phase
and attenuation characteristics
   /
3883
quantum theory of the refractive index  a perturbation theory is
used to obtain a unitary transformation which approximately diagonalizes
the total hamiltonian for a system made up of a radiation field in
interaction with gas molecules
   /
3884
a model of phosphors on the basis of quantum mechanics part kinetics
of electron and phonon reactions  the optical behaviour of a phosphor
is discussed assuming that two types of defect centre exist in the
crystal
   /
3885
a property of dielectric constants of dielectrics in thermal equilibrium
theoretical discussion of dielectrics with or without internal
sources of energy  a lumped circuit model of a molecular amplifier
with lorentz shaped bandpass characteristic is derived
   /
3886
irreversible thermodynamics and carrier density fluctuations in semi
conductors  the formalism of irreversible thermodynamics is applied
to the kinetics of carrier transitions in semiconductors  the thermodynamic
forces the generalized resistors and admittance functions are
introduced  it is shown that the thermodynamic forces which establish
the regression of a perturbed state to equilibrium are the differences
of the quasi fermi levels that have to be assigned to each group
of carriers the generalized resistances are simply related to the
transition rates  the kinetic equations for the rate of change of
the various carrier concentrations are then written in a unified
form the spectral density matrix of the spontaneous carrier fluctuations
being found from the admittance matrix  the results are then expressed
in a closed form which is valid for nondegenerate as well as for
degenerate semiconductors  the theory is applied explicitly to electronic
noise in extrinsic and near intrinsic crystals with and without
recombination centres
   /
3887
the theory of the anomalous k skin effect in metals for obliquely
incident radiation  the effective surface impedance of a metal varies
with the direction of polarization of incident radiation in the upper
visible and ultraviolet ranges  formulae for refractive indices reflectivities
and principal angles at oblique incidence are derived in
terms of two surface impedances  experimental results are in good
agreement with the theory
   /
3888
the microfield in assemblies with coulomb interaction  critical assessment
of holtsmarks theory in the light of the results of recent investigations
see also of
   /
3889
investigation of the transverse motion of ions in a discharge in
a strong longitudinal magnetic field  the influence of the gas pressure
on the average transverse velocity of ions was investigated using
a rotating probe  in an argon discharge it was found that for pressures
and in spite of a strong magnetic field of about oersteds a considerable
quantity of ions reached the side walls of the discharge chamber
so that an estimate could be made of the energy acquired by the ions
in the radial electric field
   /
3890
the demonstration of single electron avalanches and their secondary
processes in gases  continuation of earlier experimental investigations
on electron avalanches in oxygen nitrogen and air  an interpretation
of the observed delay in the formation of avalanches in nitrogen
and air is given
   /
3891
electrical discharges between coaxial electrodes  luminous corona
discharges occur when transient voltages are applied between a wire
and a small coaxially mounted ring in air  photographs show that
the shapes of the discharges differ according to the polarity of
the electrodes
   /
3892
the initiation of a vhf pulse discharge in neon  an investigation
carried out at with pulses of duration sec is described  the distribution
function of the electron velocities the kinetic coefficient of
the electron interaction with the gas molecules the hf conductivity
and the onset of discharge induced by a rectangular hf pulse are
examined the results are presented graphically
   /
3893
pulse ionization chamber as a device for simultaneous investigation
of the energy and angular distributions of charged particles
   /
3894
small oscillations in an electron beam  the stability conditions
for the propagation of small amplitude em oscillations in noncompensated
electron streams are examined and solutions for some particular cases
are obtained
   /
3895
on the space charge divergence of an axially symmetric beam  the
usual assumptions made in estimating the space charge effect are
consistent with a coaxial cylindrical conducting boundary  for small
amounts of divergence a hyperbola solution is suggested this may
in some cases be as good as or better than the usual solution even
when divergence is not small
   /
3896
small signal power conservation theorem for irrotational electron
beams  the theorem describes the balance between the rf kinetic and
rf electromagnetic powers in a laminar beam the thermal velocity
distribution at the cathode is neglected  the kinetic power flow
is expressed in terms of the chu potential the longitudinal component
of the rf beam current and the equivalent longitudinal surface current
on the beam boundary  see
   /
3897
variation of secondary emission with primary electron energy  a simple
formula is given relating secondary emission to primary electron
energy which is more in agreement with experimental results for and
than previous theoretical formulae
   /
3898
effective cross sections of electrostatic interaction in plasmas
definitions
   /
3899
effects of electron electron interactions on cyclotron resonances
in gaseous plasmas  from the boltzmann fokker planck equation a set
of equations is derived and solved numerically  the results indicate
that the real part of the electrical conductivity of the plasma power
absorption is reduced by electron electron interaction at the peak
of resonance and the width of resonance is increased
   /
3900
nonlinear phenomenological theory of plasma oscillations  damped
oscillations are shown to arise under certain conditions the intensity
of the standing waves being augmented by collisions with a loss of
efficiency  in general increasing current and plasma temperature
tend to promote oscillations while the role of plasma density is
more complex  the influence of a magnetic field in the limiting case
of no damping is also investigated
   /
3901
completely integrable singular electromagnetic field  derivation
of expressions for the components of the completely integrable singular
electromagnetic tensor with reference to maxwells equations
   /
3902
induction by an oscillating magnetic dipole over a two layer ground
expressions for the mutual electromagnetic coupling between two small
loops and for the self impedance of a loop over a two layer earth
are derived
   /
3903
effect of a gravitational field due to a rotating body on the plane
of polarization of an electromagnetic wave  it is shown that for
electromagnetic waves the gravitational field of a rotating body
acts as an optically active medium  thus the plane of polarization
of the wave rotates while it passes through this field  the effect
is small  the angle of rotation due to the gravitational field of
the sun is about radian
   /
3904
approximate calculations of the diffraction of plane electromagnetic
waves by some metallic bodies part  a new approximate method of calculation
is described which is applicable to the diffraction of em waves
by wedges or strips  the method applies to wavelengths much smaller
than the linear dimensions of the diffracting body
   /
3905
basic microwave properties of hot magnetoplasmas  the usual conductivity
tensor of a uniform plasma in a uniform static magnetic field is
generalized to include four effects of random motion of plasma electrons
the results are applied to the evaluation of the index of refraction
for microwave signals
   /
3906
investigations of the paramagnetic nuclear resonance absorption in
a capacitor field  the advantages and disadvantages of using a capacitor
field for high resolution nuclear induction spectroscopy are briefly
outlined
   /
3907
theory of saturation in nuclear magnetic resonance
   /
3908
energy band splitting and inter band terms in the dislocation of
lattice atoms in a solid
   /
3909
on the theory of a fast polaron  expressions for the dependence of
the polaron energy on its initial velocity are obtained  in connection
with polarons the breakdown voltages for ionic dielectrics are also
examined  results of investigations on alkali halide crystals are
tabulated
   /
3910
spin lattice relaxation  it is pointed out that phonon relaxation
times can be the dominant quantity measured in the usual saturation
spin lattice relaxation measurements  the analysis indicates how
pulse measurements may be used to evaluate the actual spin lattice
relaxation time independently of the phonon relaxation time
   /
3911
one dimensional impurity bands  the density of states of one dimensional
crystals consisting of functions randomly distributed has been calculated
on the ibm computer  the chains contained impurity atoms and the
most probable error in the integrated density of states at various
energies was estimated to be at most  calculations were performed
for various values of the parameter where is the density of atoms
and the attenuation constant appropriate to the isolated bound state
the results at different densities are compared with those obtained
from various physical models
   /
3912
the spur method in the problem of the exciton  the excitons in ionic
crystals are examined  the interaction of electrons and holes with
lattice vibrations is considered  it is shown that the change of
energy at low temperatures is primarily determined by the weakening
of the interaction of charged particles with the field of polarized
vibrations when the temperature rises without increase of kinetic
energy  the effective mass of the exciton is calculated  see also
of
   /
3913
the initial radius of meteoric ionization trails  kinetic theory
is applied to the formation of regions of ionized and neutral atoms
of meteoric material about the path of a meteor  it is found that
the high initial velocity of the diffusing particles causes the trail
to reach an initial radius quickly and normal diffusion then ensues
a reflected signal may be computed as if the initial radius mean
free paths were reached instantaneously
   /
3914
the random occurrence of meteors in the upper atmosphere  the distribution
of time intervals between bursts of signals over a path was studied
statistically using data obtained in two periods of two hours and
bursts respectively  results were consistent with forward scattering
from meteor trails produced by random entry of meteors into the
atmosphere
   /
3915
identification of m regions on the sun
   /
3916
the duration of emission and the slope of the pulse spectrum of solar
ultraradiation during the chromospheric eruption of and  recordings
made at various stations are analysed and discussed in relation to
various theoretical models  references
   /
3917
the calculation of the centre limb variations and the one dimensional
intensity profiles at and cm for a rotationally symmetric corona
model at constant temperature  the calculated results are compared
with those obtained from measurements by christiansen warburton and
was
   /
3918
geomagnetic disturbances associated with solar flares with major
premaximum bursts at radio frequencies mc  a close association is
found between solar flares in the early phase of which radio noise
at frequencies is received and sudden commencement ionospheric storms
on the earth  it is suggested that this rf emission may be from the
suns outer atmosphere and corona and thus may indicate which solar
flares are accompanied by the ejection of storm producing particles
although flare data are incomplete the proportion of flares having
major early bursts is estimated at and the number of flares is comparable
to the number of ionospheric storms not identifiable with well
established day recurrent series  an average time delay of days occurs
between flare and geomagnetic disturbance and the intensity of the
disturbance is related to the position of the flare on the suns disk
   /
3919
progress of sputnik  estimates of the orbital period semi major axis
now and eccentricity on and two intermediate dates are given  these
are based on observational data from different sources
   /
3920
determination of orbital characteristics of an earth satellite from
single station radio transit observations  meridian observations
of the satellite have been made by means of an interferometer located
at cleland ohio  because of the generally low altitude of the satellite
at this station horizontal dipoles were replaced by commercial yagis
   /
3921
the mesopause region of the ionosphere  observations have been made
at with pulse sounding apparatus at christchurch new zealand since
early in  initial results see of are confirmed  extended observations
indicate the continuous existence of ionization throughout a range
of heights from about to km
   /
3922
new rocket measurement of ionospheric currents near the geomagnetic
equator  rocket borne magnetometer measurements indicating current
sheets at heights of and are described  comparison with other data
indicate that at km only half the total current system had been penetrated
   /
3923
ionosphere electron density measurements with the navy aerobee hi
rocket  electron densities were measured at heights between km and
above new mexico by the doppler shift method in which the beat note
between a signal and a reference signal at was recorded  the results
corrected for obliquity effects confirm the general structure of
the ionosphere previously measured and are consistent with simultaneous
records the ionosphere remains dense between e and f regions  sporadic
e was associated with a sharp spike in the distribution at approximately
km thick
   /
3924
differential absorption in the d and lower e regions  a method of
measuring electron densities in the d region is described in which
use is made of the faraday effect in rocket flights at white sands
new mexico  at noon on a day of high absorption a value of electrons
cm was obtained for an altitude of km
   /
3925
concerning ionospheric turbulence at the meteoric level  a discussion
on the application of fluid mechanics to meteoric phenomena is continued
with particular reference to a rough trail paradox which concerns
the relative turbulent velocities of large and small eddies  the
paper is mainly concerned with the relative merits of work by booker
and cohen and by manning eshleman regarding the explanation of radar
echo fading
   /
3926
solar flare effect in the f layer of the ionosphere  is plotted as
a function of local mean time where is the difference between the
measured critical frequency and the normal value based on that measured
one hour previously  the plot for the period of the intense solar
flare of february shows a positive pulse of amplitude followed by
a second smaller pulse later  an analysis of the statistics of the
fluctuations in has been made
   /
3927
medium frequency observations of the lower ionosphere during sudden
disturbances  records obtained during sid by pulse sounding at are
analysed in detail  the observed behaviour gives support to the theory
of friedman and chubb that soft x rays and not lyman radiation are
responsible for sids
   /
3928
variations in the height of ionospheric layers during magnetic storms
statistical work carried out on washington ionospheric data for and
magnetic planetary figures from crpl publications shows that the
e layer remains unchanged in height while the f layer rises during
storms  application to parkers theory of gives as the height where
storm associated solar energy is absorbed
   /
3929
an apparent ionospheric response to the passage of hurricanes  evidence
is given for the association of the passage of a hurricane with a
departure of the critical frequency of the f layer from its monthly
mean value  the four hurricanes discussed resulted in rises in critical
frequency of up to  a possible mechanism is suggested
   /
3930
radio noise from lightning discharges  records obtained at slough
during two local thunderstorms in july and august are reproduced
including simultaneous recordings on and with bandwidths and respectively
   /
3931
between the atmospherics  an examination is made of the background
cosmic radiation between atmospherics at a frequency of  records
are explained in terms of an ionospheric shutter operated by two
mechanisms d region absorption by day and shift of coupling level
between ordinary and extraordinary modes relative to the gyro level
at night observations of precipitation static and local atmospherics
are also described
   /
3932
annals of the international geophysical year vol  the first volume
to be published of a series of instruction manuals  titles of the
parts of  ionospheric vertical soundings measurements of ionospheric
absorption the measurement of ionospheric drifts and miscellaneous
radio measurements
   /
3933
the reflection and screening effects of metallic enclosures in a
plane electromagnetic wave  three cases of reflection and screening
action are investigations for wavelengths of the order of the dimensions
of the enclosure a hollow cylinder with axis parallel to the electric
field a hollow cylinder with axis parallel to the magnetic field
and a hollow sphere  the increase of the reflection coefficient with
rising frequencies screen attenuation and resonance effects are discussed
   /
3934
nuclear batteries  outline of principles of operation and applications
   /
3935
radio waves power transistor circuits
   /
3936
voltage current characteristics of semiconductor power rectifiers
the distribution of the concentration of carriers of pin and pnn
types is examined  monomolecular and bimolecular recombinations are
considered  the dependence of the injection coefficient on the current
and the characteristics is calculated and the voltage drop in the
bulk of the semiconductor is investigated
   /
3937
medium power silicon rectifiers  the construction manufacturing techniques
and electrical characteristics of the diode type mn of pin structure
are described
   /
3938
stabilized power supplies using transistors  the operation of simple
stabilizing circuits is analysed and methods of improvement by preamplification
or compensation are discussed  practical circuits which
have low temperature coefficients are described
   /
3939
the logical design of a simple general purpose computer  the logical
design described here is used in minac partially constructed at the
california institute of technology and lgp manufactured by librascope
inc  these serial binary digital computers make use of magnetic drum
bulk storage and use three circulating registers and fifteen flip
flops
   /
3940
digital computer adding and complementing circuits  various direct
coupled transistor circuits are described suitable for use with double
gate shifting registers  the performance of these circuits operating
with a digit spacing of is illustrated with waveform photographs
   /
3941
an algorithm for determining minimal representations of a logic function
   /
3942
computing techniques for the sampling parametric computer
   /
3943
dynamic accuracy as a design criterion of linear electronic analogue
differential analyzers
   /
3944
fine graduation of the timing pulse generator disk of an electronic
computer  the construction is described of a disk providing the synchronizing
pulses for the storage system of a digital computer  the nonferromagnetic
disk of about diameter carries a thin layer of nickel near
the rim  the layer is cut by radial grooves of width and there are
five concentric tracks with differing numbers of grooves  the outer
track thus consists of ferromagnetic teeth which at rev min generate
pulses at a repetition frequency of about  details of the dividing
and engraving machinery are given
   /
3945
nondestructive memory employing a domain oriented steel wire  a magnetic
storage system using a steel wire under tension is described  a small
solenoid is used to magnetize the wire locally and for observing
the flux change produced by an interrogative current pulsed through
the wire itself
   /
3946
an electronic analogue multiplier using carriers  an electronic analogue
multiplier is described which is based on a modulation technique
no dc amplifiers are used which makes the output entirely free of
drifts  all distortions up to the fourth order are eliminated  the
experimental model that has been built handles inputs from dc to
and gives an output from dc to  the amplitude range of the output
is
   /
3947
trigonometric resolution in analogue computers by means of multiplier
elements  abstract
   /
3948
stability and convergence limitations on the use of analogue computers
with resistance network analogues  it is shown that the solution
of equations such as breaks down if the gradient of is negative and
sufficiently large to cause the correct solution to be wavelike
see also of and
   /
3949
electronic integrator with immediate digital output  details are
given of a technique for obtaining an instantaneous numerical value
proportional to the area of a recurring voltage transient  the basic
principle is to summate the pulses from a generator whose repetition
rate is a linear function of the instantaneous input voltage  the
system has a high order of linearity approximately and is used for
roughly triangular pulses of duration
   /
3950
an improved electromagnetic integrator  description of a permanent
magnet moving coil system for integrating an electrical signal of
varying polarity over integration times as long as one day
   /
3951
symposium on computers  the text is given of seven papers read at
a symposium held at mt eliza victoria december
   /
3952
magnetostrictive delay line  equivalent electromechanical circuit
for a magnetostrictive nickel delay line is given  the optimum matching
at the input and output end is discussed
   /
3953
magnetic core memory cell with nondestructive read out  outline of
a method of using different values of incremental permeability of
a dc biased magnetic core to obtain a binary storage cell  one of
the possible applications is for visible indication of binary states
in magnetic shift registers
   /
3954
a transistor driven magnetic core memory  description of a storage
system with a capacity of words designed for a transistor airborne
digital computer tradic at bell telephone laboratories  both the
read and write operations are based on a coincident current technique
   /
3955
current steering in magnetic circuits  magnetic switches are described
in which the current from an energizing source is guided or steered
through one out of many possible parallel branches the conducting
branch being selected by the presetting of appropriate magnetic elements
   /
3956
the logic of bidirectional binary counters
   /
3957
a new diode function generator
   /
3958
a cathode ray tube analogue to serial digital converter  small fluctuations
of the cr tube screen equilibrium potential cause proportionate
fluctuations in the steady secondary emission current arriving at
a collector anode  the parameters affecting changes in this current
are investigated using an external electrode on the cr tube face
to modulate the screen potential  experiments are described to determine
minimum electrode width and spacing consistent with the production
of a discrete pulse output from each electrode when a pattern is
scanned
   /
3959
printed circuits  a review of printed circuit techniques suitable
for modular equipment
   /
3960
divided output transformers  to overcome self capacity in the primary
winding of an af output transformer at high frequencies the output
from the final stage may be fed to two transformers one for the low
frequency and the other for the high frequency range  this overcomes
the necessity for a single high quality transformer and the output
can be fed directly to two separate loudspeakers
   /
3961
contribution to the study of a rectifier in series with an inductive
resistance  different hypotheses are considered for expressing the
voltage drop across the rectifier at low frequencies values of mean
and maximum current are calculated according to each hypothesis and
compared with vith values measured using a coil of inductance and
resistance in series with a valve rectifier  a circuit for measuring
low peak voltages using a gas filled tetrode is described
   /
3962
capacitive phase shifters  the design is described of a continuous
phase shifter consisting of a variable capacitor with four groups
of stator plates and one group of kidney shaped rotor plates
   /
3963
a field effect varistor  a two terminal passive semiconductor is
described in which the current can be held constant within in the
voltage range v  currents from to can be handled the ac dc resistance
ratio in this region is of the order of
   /
3964
elementary proof of an extended reactance theorem for two terminal
networks  a proof is derived for fosters reactance theorem which
is also applicable to its extended form covering loss free circuit
elements and transmission lines
   /
3965
high q quartz crystals at low temperatures  q measurements in the
range to over for several modes of vibration are described  in one
case a value of was obtained
   /
3966
elimination of unwanted modes of oscillation in cylindrical cavities
the possible modes in high q cylindrical cavity resonators are analysed
and the suppression of residual modes by special coupling systems
or discontinuities inside the cavity is discussed  measurements were
made on ten tunable cavities of different size covering the frequency
range  a frequency modulated source was used to determine the permissible
limits of the cavity tuning range and the dimensions of the discontinuities
for obtaining the desired attenuation of unwanted modes without
reducing q by more than  the modes and their amplitudes are tabulated
   /
3967
q factors of a transmission line cavity
   /
3968
exponential transmission lines as resonators and transformers
   /
3969
general method of analyzing bilateral two port networks from three
arbitrary impedance measurements  the method consists in mapping
stereographically on the surface of the riemann unit sphere three
given output quantities and their corresponding measured input quantities
the fixed points and the multiplier of the normal canonic form
of the linear fractional transformation representing the network
can be obtained by using kleins three dimensional generalization
of the pascal theorem  the different constructions of the geometric
part can also be performed analytically  simple numerical examples
are worked out
   /
3970
transformation quadripoles according to the insertion loss theory
the design of filter networks with prescribed attenuation characteristics
and impedance transformation in the pass band is discussed  see
also of
   /
3971
graphical determination of matching sections  a description of graphical
methods using the smith chart for matching impedances by means of
l or t sections
   /
3972
degenerate solutions and an algebraic approach to the multiple input
linear filter design problem
   /
3973
optimum filters for independent measurements of two related perturbed
messages
   /
3974
antenna filters for a military radio system  high q coaxial filters
are described covering both transmission and reception over the range
in only sub bands
   /
3975
bandwidth limitations in equalizers and transistor output circuits
   /
3976
temperature compensated crystal oscillators  in the method described
a passive network containing a thermistor is enclosed in the same
envelope as the crystal
   /
3977
the cathode coupled multivibrator considered as a coupled pair of
two therminal networks  the multivibrator is considered as an active
two terminal network with negative differential resistance together
with a passive two terminal network  formulae derived on this basis
for determining the multivibrator operating characteristics give
results in close agreement with experimental values
   /
3978
sawtooth generators with commercial type values for producing deflection
voltages of high amplitude and extremely short duration  the circuit
of a special high speed oscillograph with a time base resolution
of is described which was used for examining the waveforms produced
by various pulse generators investigated  pulse amplitudes of with
rise time and have been obtained
   /
3979
transistorized photomultiplier has resolution  description of high
sensitivity photomultiplier circuit for use in a scintillation counter
   /
3980
secondary emission tubes in coincidence circuits  switching waveforms
of a trigger circuit based on a valve type efp are analysed and switching
speed and operating conditions are discussed
   /
3981
harmonic amplifier for x band local oscillator  the final frequency
tripler in a harmonic amplifier cascade uses an uhf triode with coaxial
cathode input resonator and a wave guide output resonator giving
about output
   /
3982
a one valve dc amplifier with high impedance input  a simple one
valve high impedance probe circuit intended for direct connection
to a dc amplifier is described  drift is about in the first half
hour of use  a simple method of reducing the input time constant
is also given
   /
3983
low noise amplifier  circuit details are given of a cascade amplifier
using disk seal triodes designed for the study of semiconductor noise
at low temperatures  the theoretical noise figure of the amplifier
is calculated and compared with the value obtained from radiometer
measurements
   /
3984
temperature stability of transistor class b amplifiers  this is discussed
generally and in relation to three types of circuit commonly used
graphical design methods for achieving optimum stability are developed
and comparative practical results are given
   /
3985
the maser  a review of development describing the principles of molecular
beam negative temperature optically pumped and solid state masers
   /
3986
maser amplifier characteristics for transmission and reflection cavities
the noise temperature bandwidth and gain modulation for transmission
and reflection type masers are compared  the latter type is superior
in most respects although the same noise temperature may be obtained
with the transmission type with some sacrifice in bandwidth and gain
modulation  a figure of merit for both types is given
   /
3987
a ferromagnetic resonance frequency converter  an experimental and
theoretical study of a converter using a magnetized disk of single
crystal yttrium iron garnet  inputs at and are used to produce an
output at in a cavity resonant at all three frequencies  the output
power agrees with that expected theoretically within experimental
error  see also of
   /
3988
a parametric amplifier using lower frequency pumping  experimental
verification of the principle of parametric amplification using a
pumping frequency lower than the signal frequency is described  variable
inductance ferrite core and variable capacitance semiconductor diode
elements have both been used the former at with pumping at and the
latter at with pumping at  bandwidth and noise have been measured
as functions of gain for the diode amplifier and the results compared
with theory  see also of june and
   /
3989
linear frequency discriminator for subcarrier frequencies  the discriminator
uses a heptode valve with out of phase signals on its two control
grids  it is suitable for low frequency fm signals having large deviations
   /
3990
the electrodielectric induction  an analogy between magnetic and
dielectric quantities discussed earlier is developed with special
reference to dynamic phenomena
   /
3991
the method of secondary quantization in phase space  a statistical
analysis of systems of interacting particles in which use is made
of the number of particles in various points of coordinate momentum
phase space which at every point of phase space are random functions
of time  this method can be used for considering particles and fields
in electromagnetic interaction
   /
3992
dimensions for a unified theory of electromechanics  a dimensional
relation between voltage and mechanical force is derived and a set
of three dimensions length time and the square root of force is proposed
for a unified theory
   /
3993
interaction of charged particles in a dielectric  analytical results
may be summarized by the statement that if sufficiently distant external
charges in a dielectric interact with each other and with the charge
of an extra electron or hole as if all charges were renormalized
according to the expression
   /
3994
absorption in a dielectric slab  energy incident on a parallel slab
of high loss material with high dielectric constant is considered
at angles of incidence greater than the reflected energy is smaller
the more lossy the material  the absorbed energy is a maximum at
certain angles of incidence depending on the polarization and dielectric
constant
   /
3995
magnetic forces and relativistic speeds in stationary electron beams
in nonrelativistic electron beams magnetic forces may have to be
considered they are still more important in relativistic beams  care
must be taken in using the results of calculations in which these
forces are neglected
   /
3996
note on positive ion effects in pulsed electron beams  experimental
results are given for electron beams of duration under conditions
normally encountered in high power microwave valves
   /
3997
energy spectrum of an electron beam after passing through a thin
metallic film  the energy loss is determined for films of al cr bi
au ag and cu
   /
3998
very high voltage electron diffraction  description of a diffractograph
operating at voltages up to
   /
3999
the use of electron diffraction for magnetic analysis  brief note
on a method of evaluating magnetic field strength from the eccentricity
of superposed diffraction rings
   /
4000
electron scattering phenomena  new methods of investigations are
reviewed
   /
4001
diffusion and elastic collision losses of the fast electrons in plasmas
when the energy spectrum in ne at mm hg pressure can be separated
into a primary high energy and a secondary low energy maxwellian
group then the mean free path of the fast electrons can be evaluated
by use of the diffusion law is found to be independent of the plasma
density  it is remarkable that there is little interaction between
fast and slow groups even when the density of the slow one becomes
comparable to or even higher than that of the fast group
   /
4002
electron energy distributions in uniform electric fields and the
townsend ionization coefficient  the second order differential equation
which expresses the equilibrium conditions of an electron swarm in
a uniform electric field in a gas the electrons suffering both elastic
and inelastic collisions with the gas molecules is solved using the
jeffreys or wkb method of approximation  the theory is illustrated
by a comparison of calculated and observed results for hydrogen
   /
4003
experimental examination of holtsmarks theory of line broadening
   /
4004
deviation from the holtsmark shape of the balmer lines in plasma
   /
4005
scattering of electromagnetic waves in a plasma  the intensity of
combination scattering due to plasma density oscillations is determined
with and without a constant uniform magnetic field
   /
4006
suppression of plasma oscillations  in a hot cathode discharge tube
containing gas at low pressure oscillations of frequency can be generated
the oscillations can be suppressed by mounting a plane anode
and cathode sufficiently close together the discharge can still be
maintained
   /
4007
on the propagation of hydromagnetic waves in compressible ionized
fluid  mathematical treatment based on a method of characteristics
   /
4008
the behaviour of a completely ionized plasma in a strong magnetic
field
   /
4009
mass spectroscopy investigations of photoionization in gases  experimental
equipment is described and references are given
   /
4010
the theory of ferromagnetic resonance at high signal powers  it is
shown that two anomalous effects in the microwave absorption of ferromagnets
are connected with two kinds of instability of the uniform
precessional motion of the total magnetization against certain spin
wave disturbances  the susceptibilities are calculated for the final
state attained by the medium with high signal levels and are shown
to agree with experiment
   /
4011
reflection and refraction in magnetohydrodynamic  fluids of finite
conductivity are considered on the basis of the euler minkowski system
for hydromagnetic waves propagated in a direction differing from
that of the external magnetic field
   /
4012
investigation of and compensation for the inhomogeneity of the magnetic
field of an electromagnet
   /
4013
stabilization and control of an electromagnet by means of magnetic
proton resonance  long term magnetic field stability of the order
of is obtained by means of a proton resonance system incorporating
a magnetic field discriminator circuit and a variable frequency transitron
circuit
   /
4014
on the reflection of electromagnetic waves on a rough surface
   /
4015
propagation of plane electromagnetic waves in a directional conductor
with variable direction of conductivity  propagation through a series
of directional screens is considered each screen being rotated by
the same angle with respect to the adjacent screen
   /
4016
the theory of electromagnetic waves in a crystal in which excitons
are produced  it is shown that in a crystal several waves of the
same frequency polarization and propagation direction exist but with
different indices of refraction this phenomenon differs from double
refraction of light and occurs even in isotropically polarizing cubic
crystals
   /
4017
diffraction patterns at the plane of a slit in a reflecting screen
measurements were made of the diffraction pattern in slits ranging
in width from to  microwave radiation of and was used  ratios of
intensity in the slit to intensity of the unperturbed beam were determined
for plane polarized radiation incident on the conducting screen
   /
4018
diffraction by a perfectly absorbing thin screen  comparative measurements
of the diffraction patterns in and near slits of perfectly absorbing
and reflecting thin screens show that the reflected diffraction patterns
of the slits are the same for distances greater than
   /
4019
the edge conditions and field representation theorems in the theory
of electromagnetic diffraction  addendum to
   /
4020
wavelength dependence of scattering coefficient for infrared radiation
in natural haze  a formula consistent with the mie scattering coefficient
is given for see of june
   /
4021
propagation in a gyrational medium
   /
4022
cooperative phenomena in quantum theory of radiation  cooperative
effects in systems having dimensions small relative to the wavelength
are investigated in relation to the quantum mechanical identity principle
the application of this effect to a gas maser is mentioned
   /
4023
the radio source in the direction of the galactic centre  observations
of radio flux densities at frequencies from to show that the radiation
could originate from a nonthermal source lying behind ionized hydrogen
   /
4024
radio observations of a lunar occultation of the crab nebula  comparison
of brightness distributions at and shows a difference in apparent
size of the radio source  details of the lunar atmosphere are also
obtained see below
   /
4025
radio observations of the lunar atmosphere  the refraction occurring
in the lunar atmosphere is estimated from observations at of the
lunar occulation of the crab nebula on january  the electron density
at the moons surface is derived for an atmosphere in hydrostatic
equilibrium and for a continuously escaping atmosphere
   /
4026
the distribution of brightness at metre wavelengths across the suns
disk
   /
4027
apparent temperatures of some terrestrial materials and the sun at
millimetre wavelengths  report of measurements made using a dicke
type radiometer  the apparent temperature of the sun was between
and  at vertical angles the sky temperature was under clear conditions
but cumulus nimbus cloud raised this to a value nearly equal to that
for ground level air
   /
4028
magnetohydrodynamic shock waves in the solar corona with applications
to bursts of radio frequency radiation  shock fronts ahead of corpuscular
streams may account for type and type bursts  detailed calculations
are given based on a set of transport equations previously derived
for an ionized gas of
   /
4029
variation in the speed of rotation of the earth since june
   /
4030
the general expression of the diurnal variation of the atmospheric
electric field considering the influence of the eddy diffusion near
the ground
   /
4031
simultaneous measurement of air earth current and the atmospheric
electric potential gradient
   /
4032
oscillations of a system of disk dynamos  the behaviour of two disk
dynamos coupled to one another is examined in relation to the earths
magnetic field  it is found that reversals of electric current and
magnetic field occur unlike the case of a single disk dynamo  see
also of
   /
4033
the earths magnetic field above wspg new maxico from rocket measurements
the absolute magnetic field was measured from ground level to
km with a proton precessional magnetometer  the typically quiet field
differed significantly from that of a dipole but no ionospheric discontinuity
was found
   /
4034
some observations of geomagnetic micropulsations  these new observations
of diurnal variation direction and frequency spectrum are viewed
in comparison with published data and it is suggested that they have
a solar time dependence and may occur locally  at two stations in
longitude apart related signals are only occasionally observed  however
the phase relationship l of the few which are related together with
differences in direction characteristics reported by other observatories
are not in agreement with recent theories of the origin of micropulsations
   /
4035
the propagation velocity of world wide sudden commencements f of
magnetic storms  a model is presented in which a longitudinal hydromagnetic
wave generated by impact between a plasma cloud from the sun
and the earths field travels east and west round the geomagnetic
equator  the wave will be stable at altitude and traeel at about
   /
4036
the magnetic storm effects and the interplanetary electromagnetic
state  alvens theory that a beam of rarefied ionized gas is ejected
from the sun can be applied to explain terrestrial cosmic ray observations
and magnetic storm effects
   /
4037
visual thresholds for detecting an earth satellite
   /
4038
effect of length of observing time on the visual threshold for detecting
a faint satellite  may  formula for inferring atmospheric density
from the motion of artificial earth satellites
   /
4039
effect of the earths equatorial bulge on the lifetime of artificial
satellites and its use in determining atmospheric scale heights
   /
4040
calculation of the lifetime of a satellite
   /
4041
explorer over africa  records of visual observations made in south
f africa
   /
4042
determination of radio propagation elements due to an artificial
earth satellite  a simple formula is given expressing path length
for determining the virtual position of a radiating source
   /
4043
the international geophysical year indian programme
   /
4044
high altitude infrared studies of the atmosphere  a balloon flight
with a littrow spectrometer gave spectra from ground level to ft
water vapour bands had completely disappeared above
   /
4045
calculation of true heights of electron density in the ionosphere
by assuming that the electron density distribution can be approximated
by taking linear sections of variable length records may be manually
converted to true height electron density profiles  the method takes
into account the earths magnetic field and is similar to that used
by jackson  results are compared with actual electron density profiles
derived from rocket observations
   /
4046
the analysis of rocket experiments in terms of electron density distributions
the relative delay o of a pulsed signal as a function of
rocket position is used to deduce the electron density distribution
to heights of about km  the data are analysed for ascent and descent
at frequencies of and peaks are shown at and and an intense irregularity
on ascent at km  good agreement with a simultaneous record is obtained
   /
4047
solar activity and radio communication  the monthly median value
of the f critical frequency for noon during december was the highest
december average value ever recorded at slough  this gives a value
close to for the demarcation frequency used for planning radio communication
in temperate latitudes
   /
4048
correlation of the initial electric field and the radar echo in thunderstorms
precipitation as detected with radar is a necessary but not
sufficient condition for significant cloud electrification  the presence
of detectable precipitation does not lead to thunderstorm electrification
unless the precipitation echo shows rapid vertical development
   /
4049
the development and masking of charges in thunderstorms
   /
4050
auroral absorption of cosmic radio waves on february  a relative
absorption of approximately was recorded near troy ny during a spectacular
auroral display
   /
4051
the role of f layer tilts in detection of auroral ionization  back
scatter echoes received at stanford california from the auroral e
region are shown to be propagated by way of a tilted f layer  the
rays returned from the e region scattering source proceed to the
f layer without intermediate earth reflection  the f layer is so
tilted that the rays are then returned to the receiver  a tilted
mirror model of the f layer demonstrates the effect  this explanation
is shown to be more probable than that in which the echoes are presumed
to be returned from auroral ionization at great heights although
this latter explanation may occasionally be true
   /
4052
natural electrical oscillations in the earth air ionosphere cavity
excited by lightning discharges  the theory underlying the experimentally
observed resonance effects is discussed
   /
4053
thermoelements and thermoelectric dc generators  detailed theoretical
investigation of thermodynamic efficiency taking account of the various
thermoelectric effects and changes in resistivity and thermal conductivity
higher efficiencies should be obtainable than those indicated
by other authors  problems of construction and mechanical strength
are also considered
   /
4054
low resistance earth electrodes their achievements and accurate measurement
the electrical characteristics of various soils and the effects
of moisture content temperature and additives as well as electrode
shape and spacing are discussed  electronic computer research  a
note on the research program of the national bureau of standards
followed by ten short papers with titles as under  a high speed multiplier
for electronic digital computers  processing pictorial information
on digital computers  low power plug in packages for electronic computer
circuitry  seac converted to applications research facility  a function
generator for two independent variables  man machine simulation system
problem solving on the high speed computer  chemical structure searching
with automatic computers  magnetic amplifiers for digital computers
diode amplifier shift register
   /
4055
electronic computers  a survey with tabulated data on german equipment
references
   /
4056
accuracy control in electronic business data processing systems
   /
4057
digital codes in data processing systems  simple digital correlator
a description is given of a simple electronic correlator which employs
punched tape input and visual digital readout  code cathode counting
tubes are used in the arithmetic unit  several basic design considerations
are briefly discussed and an outline is given of the recent application
of the correlator to a problem in meteor physics
   /
4058
an improved technique for fast multiplication on serial digital computers
   /
4059
half adders drive simultaneous computer  a combination of transistorized
half and full adders emitter followers output amplifiers and multiplier
gates provides simultaneous binary addition of digital inputs
   /
4060
relay scanning design technique generates high accuracy and speed
in analogue to digital transducer measurements  the converter is
designed to handle three decades of binary decimal pulses each decimal
unit is equivalent to input  the converter scans an internal voltage
until it becomes equal to the unamplified input voltage and supplies
a serial pulse output
   /
4061
the design of function generators using short time memory devices
and nonlinear elements  the various types of function generator discussed
have easily controllable output waveforms which can be made to
approximate to any desired shape with a high degree of accuracy
   /
4062
an electronic differential analyser  equations are derived to show
the effect of errors due to co circuit elements and some experimentally
obtained solutions are compared with calculated values
   /
4063
on the application of an electronic differential analyser for finding
the roots of a polynomial  a transfer function is used with the polynomial
as numerator and another suitable function as denominator  the
roots are given by the zeros of the system
   /
4064
digital field computers  to eliminate the speed limitation of conventional
digital techniques for field computations a nonuniversal unitary
system is proposed based on the analogy between electron flow through
a resistance network and the flow of pulses through a network of
computer units  an integral number n is represented by n pulses and
a basic unit generates a train of synchronized pulses from two input
pulse trains of n and n pulses  the interconnection of a lattice
of basic units gives a finite difference representation of the general
field equation
   /
4065
an automatic graph plotter  the adaptation of an analogue plotting
table for accepting input data in digital form is described
   /
4066
the application of digital computers to nuclear reactor design  the
main computational problems are reviewed together with examples of
the treatment of neutron transport problems  an assessment is made
of the performance requirements of future computers
   /
4067
use of laguerre filters for realization of time functions and delay
   /
4068
analogue multiplier and function generator with cathode ray tube
a capacitive pick up device is mounted outside the cr tube in front
of the screen it is easily replaced so that the same tube can be
used as multiplier or for generating different types of functions
   /
4069
an electronic computer for statistical analysis of radio propagation
data
   /
4070
printed circuits  review of materials and manufacturing processes
   /
4071
coils for magnetic fields  a comparison between wire wound foil wound
and coaxial cable wound solenoids considering the limitations of
temperature rise and weight  equations relating field power and internal
temperature difference are obtained from which the performance of
any coil can be calculated  the relative advantages of al or cu windings
are considered
   /
4072
a note on the self resonance of ceramic capacitors  details of changes
in self resonant frequency with capacitor type length of connecting
leads and method of mounting are given  practical applications of
the self resonance of these components in vhf circuits are suggested
   /
4073
certain applications of matrices to circuit theory  matrices can
be constructed for circuits so that their eigenvalues and vectors
relate to the circuit parameters  propagation constants characteristic
impedances and symmetrical components in polyphase systems are considered
from this point of view
   /
4074
synthesis of series parallel network switching functions  from the
switching functions of n variables those which correspond to networks
are abstracted and called network functions  properties of those
network functions corresponding to series parallel networks are studied
and a method for synthesis is developed
   /
4075
high power radio frequency broad band transformers  the design of
wide band transformers composed of simple transmission line elements
and capable of handling radio frequency power of the order of is
discussed  examples are given of devices matching ohm coaxial cable
to balanced pair transmission lines with a standing wave ratio of
less than over the band
   /
4076
complex matching  the conditions are investigated for obtaining maximum
real power at the input of a complex load matched to a generator
with complex internal impedance
   /
4077
analysis and synthesis of delay line periodic filters
   /
4078
pulse distortion by band filters  the roots of the homogeneous differential
equations for image parameter band pass filters with one to
four stages are tabulated  the integration constants are determined
for the case of a square wave modulated carrier equal to the mid
band frequency of the filter
   /
4079
design of unsymmetrical band pass filters
   /
4080
simplifying phase equalizer design  a graphical method using bridged
t and all pass lattice networks
   /
4081
power amplification bandwidth figure of merit for transducers including
transistors  a figure of merit based on spot frequency maximum power
amplification bandwidth is derived for a transducer which is unilateralized
and conjugately matched the result being simplified by assuming
a bell shaped frequency response  specific formulae are given for
valve and transistor circuits  see eg of
   /
4082
on the synthesis of three terminal networks composed of two kinds
of elements  a set of necessary and sufficient conditions and a method
of realization of all sets of series parallel lc three terminal network
functions from the zeroth to the sixth degree are given
   /
4083
a low noise crystal controlled converter for  construction details
of a converter providing satisfactory reception of signals of about
above noise level
   /
4084
millimicrosecond pulse generator  the generator uses a length of
high frequency cable which is charged from a known dc potential
the cable is then discharged into the load by a magnetically operated
mercury switch at pulse repetition frequencies up to for pulses of
rise time
   /
4085
calculations for a capacitor with rotating armatures piloting a very
low frequency generator
   /
4086
fluctuations in quartz crystal oscillators  results of an analysis
using symbolic differential equations show that the noise and thermal
fluctuations are not determining factors for stability  see also
of
   /
4087
thermally compensated crystal oscillator  frequency stabilization
without the use of a temperature controlled oven is obtained by varying
the effective shunt load of the crystal a thermistor bead being the
temperature sensitive element  transistor circuit varies reactance
frequency control of a oscillator to within is achieved by means
of a variable reactance circuit which produces an effective capacitance
change of up to for a change in emitter current from zero to
   /
4088
a neon pulser for the computer laboratory  an output of peak positive
or negative at pulse repetition frequencies from less than to is
obtained
   /
4089
high speed pulse amplitude discriminator  a circuit is described
for use in fast counting systems  it handles pulses of amplitude
generating a positive output pulse of constant amplitude whose length
is determined by the length of the input pulse  dead time is about
and peaks apart are separated
   /
4090
optimum noise performance of linear amplifiers  a single quantitative
measure of amplifier spot noise performance is established which
removes difficulties associated with the effect of feedback on the
noise figure as it is a function only of the amplifier noise and
circuit parameters  it determines the lowest noise figure obtainable
at high gain with a given amplifier used alone or passively connected
to other amplifiers of the same and it provides an index of the absolute
quality of noise performance
   /
4091
performance calculations for dc chopper amplifiers  switched chopping
and demodulating circuits are analysed and methods of calculating
the essential parameters are described
   /
4092
dc amplifier expands input voltage range  a direct coupled dc amplifier
with infinite input voltage range and infinite input impedance is
described and details are given of its application in a differential
valve voltmeter without input voltage dividers for measurements at
mean levels between and
   /
4093
the generation and amplification of millimetre waves  a detailed
survey of techniques and devices including the maser and the harmodotron
references
   /
4094
the design of primary and secondary radar if amplifiers  the features
of synchronous and stagger tuned circuit arrangements are discussed
and design procedures outlined  practical considerations such as
feedback coil design and heat dissipation and the design of amplifiers
having logarithmic characteristics are also covered
   /
4095
direct or ac coupling for deflexion amplifiers  a quasi dc coupling
system using a vertical deflection amplifier input switch providing
dc reference pulses for level clamping is described  it is suitable
for the range dc and the range of dc shift can be extended indefinitely
as far as insulation permits
   /
4096
a direct coupled phase splitter  a precision cathode follower and
inverter are described having an output resistance of about and a
frequency response from dc to beyond and
   /
4097
ringing amplifier  a circuit for amplifying pulses by in a radar
transponder is described  damped oscillations produced by the transient
response of a tuned circuit are amplified and the second half cycle
selected to trigger the transponder  the unit is of small size and
has a low power consumption and a fixed internal delay of
   /
4098
bootstrap circuit technique  the normal amplifier the cathode follower
and the anode follower are shown to comprise a set of four circuits
related to one another by simple circuit transformations  three methods
of excitation are distinguished  each circuit may be put into feedback
form and the four basic feedback configurations applicable to bootstrap
amplifiers are given  a number of practical examples are described
   /
4099
magnetic amplifiers  the use of magnetic amplifiers at static switching
devices is discussed  switching action is obtained by biasing to
saturated or unsaturated states  a binary to quaternary decoder using
this principle is described
   /
4100
magnetic amplifier design  commencing with the basic information
of power supply frequency desired gain and time constant charts are
developed to determine the core design with reference to load voltage
and current  with a specified core additional charts are presented
to determine the design of the winding layout
   /
4101
superconducting rectifier and amplifier  to avoid heat losses due
to heavy current leads in apparatus at liquid helium temperatures
a high voltage ac supply is applied to a transformer which is coupled
to the load through a coil of superconducting material  by applying
a magnetic field parallel to the axis of the coil a dc component
is produced in the load  a current amplification factor of is obtained
at using coils of wire drawn from lead tin solder
   /
4102
collector bias the transistor equivalent of cathode bias and some
applications  a self bias circuit for stabilizing the operating point
of a transistor amplifier without unduly decreasing the gain at very
low frequencies is discussed  expressions for the frequency response
stability and input impedance are derived and the application of
the circuit to amplifiers oscillators and active filters is considered
   /
4103
diode cuts transistor cut off current drift  amplified thermal variations
of cut off current in grounded emitter amplifiers can be compensated
by compensated by connecting a diode experiencing the same thermal
changes and having similar collector base junction saturation current
characteristics across the transistor base emitter junction
   /
4104
a stabilized dc differential transistor amplifier  design details
and performance characteristics of a circuit which is insensitive
to temperature changes  the method employed eliminates feedback and
compensating circuits with their attendant complications and disadvantages
   /
4105
designing multiple feedback loops  design considerations applicable
to transistors in the common cathode common base or common emitter
connections are discussed  theorems for determining the gain of any
multiple loop circuit and a stability criterion are given
   /
4106
the saturation effect in a system with three energy levels
   /
4107
a three level solid state maser  nonmathematical description of three
level maser operation including a mechanical analogy  some constructional
details and operating characteristics of a particular model amplifying
at are given
   /
4108
low noise amplifier  description of a parametric amplifier using
a variable capacitance in the form of a diffused base si diode with
an active area in diameter  advantages and applications of such amplifiers
are discussed
   /
4109
ring modulator reads low level dc  dc signals in the range are fed
via a logarithmic si diode attenuator to a ring modulator and converted
to ac which is amplified and serves as a measure of the dc input
   /
4110
the forty eighth kelvin lecture infrared radiation  historical survey
with details of applications in the field of infrared spectroscopy
   /
4111
importance of the faraday to elemental constants and electricity
standards  the ratio em can be determined with high accuracy and
without uncertainties due to electrical standards and the acceleration
of gravity using the value of the gyromagnetic ratio of the proton
determined from precision measurements the cyclotron frequency of
the faraday determined electrochemically
   /
4112
anisotropic effects in geometrically isotropic lattices  an analysis
of the anisotropy produced by an arbitrary ratio of element spacing
to wavelength in an artificial lattice dielectric  the granularity
which is important at high frequencies is considered in detail
   /
4113
the electric properties of a dielectric with a variable number of
relaxation centres  expressions are derived for permittivity and
of dielectric loss tangent  it is shown that the number of ions and
dipoles which give rise to relaxation polarization increases with
temperature leading to an increase of permittivity
   /
4114
plasma approach to metallic conduction  normal and superconductive
response in metals may be construed as limiting modes of metallic
conduction using a theory of plasma interaction
   /
4115
report on the course of the international school of physics of the
italian physical society varenna  report of the proceedings of the
course on solid state physics held at the villa monastero varenna
the text is given of lectures and discussions including the following
optical properties of solids  the transition from the metallic to
the nonmetallic state  electrons and plasmons  transport properties
of solids  point imperfections in solids  dislocations in germanium
and silicon  properties of semiconductors  semiconducting compounds
shallow impurity states in semiconductors  recombination processes
in semiconductors  semiconductors with charge carriers of low apparent
mass
   /
4116
the theory of the anomalous skin effect in metals  information concerning
the fermi surface obtained from measurements of surface impedance
in the region of the anomalous skin effect does not depend on whether
the conduction electrons are considered as a gas or as a degenerate
fluid
   /
4117
skin effect with shock waves  approximate formulae are given for
the skin effect in a cylindrical conductor traversed by a shock wave
   /
4118
the impulse breakdown characteristic of a point plane gap in air
the influence of the duration of the impulse wave on the breakdown
characteristics for both polarities was investigated for air at a
pressure of cm hg and temperature c
   /
4119
the complex formulation of the equations for two dimensional space
charge flow  the equations satisfied by an electron for congruent
space charge flow are solved using a complex variable formulation
for a constant magnetic field normal to the flow  solutions are also
obtained in the presence of magnetic fields and for flow along the
level lines of a harmonic function
   /
4120
containment of a fully ionized plasma by radio frequency fields
a fully ionized plasma is treated as a compressible loss free dielectric
in a rf field  it is shown that there are steady forces which may
be used to confine a body of dense plasma in a conducting cavity
resonant in a suitable mode  a particular solution the e cut off
mode for which extensive numerical calculations have been made is
discussed in some detail and interpreted in terms of possible physical
experiments
   /
4121
investigations on the occurrence of high frequency oscillations in
an ion source with magnetic guiding field  oscillations at about
were observed in and and their amplitude and frequency were measured
under various conditions  the effect is interpreted as an acoustic
type of plasma oscillation
   /
4122
oscillations in a plasma with oriented dc magnetic field  the angular
dependence of the double resonances representing coupling of a low
energy plasma and cyclotron oscillations is studied for all orientations
of the dc electric and magnetic fields using a nonlinear phenomenological
approach  conditions favourable for manifestation of these modes
are indicated
   /
4123
statistics of the ising ferromagnet  the ising model is treated by
synthesizing a cluster treatment with the spherical model which is
used to determine approximately the molecular field acting on the
cluster and the effective interactions between dipoles of the cluster
the method is applied to the square net and to the cubic lattice
and the critical temperatures are obtained
   /
4124
the use of the kerr effect for studying the magnetization of a reflecting
surface  if a domain wall moving in an alternating field crosses
a small area illuminated with plane polarized light the change in
intensity of the reflected light passing through a nearly crossed
analyser can be detected by use of a photo multiplier cell and by
amplification of the alternating component of its output signal
experimental results agree well with theoretical predictions  see
also
   /
4125
paramagnetic centres as detectors of ultrasonic radiation at microwave
frequencies  it may be possible to detect microwave phonons generated
by an electromechanical or magnetomechanical transducer by observing
their effect on the saturation of an electron spin resonance line
the quantitative aspects of this are estimated
   /
4126
the equations of electromagnetic induction  the association of maxwells
electromagnetic equations with einsteins space time equations is
considered
   /
4127
stark effect resonant cavity microwave spectrograph  the construction
and use of a cavity for a k band stark modulated spectrograph are
described  the cavity is a circular cylinder of variable length operating
in the te modes see also of
   /
4128
improvement in millimetre wave detection  a modification of the detector
used in mm spectroscopy of is described which facilitates the adjustment
the cats whisker
   /
4129
the saturation effect in a system with three energy levels  mathematical
analysis of the effect of a high frequency alternating field with
given harmonics on a system with three energy levels  expressions
are derived for dielectric constant or permeability applicable to
maser operation
   /
4130
spin lattice relaxation resonances in solids  preliminary experiments
suggest the importance of a spin lattice relaxation mechanism in
certain cases  possible applications to spin echo storage devices
and to masers are outlined
   /
4131
some features of the motion of rapid current carriers in polar crystals
investigation of the behaviour of polarons majority current carriers
in crystals with increase of energy
   /
4132
gain measurements of large aerials used in interferometer and cross
type radio telescopes
   /
4133
radio telescope sees billion light years  details are given of the
drive control system associated with the jodrell bank radio telescope
see also of
   /
4134
the computer and control for the telescope at jodrell bank  the analogue
computer and the drive and correction systems which it controls are
described
   /
4135
further observations of radio emission from the planet jupiter  characteristics
of radiation at are described in detail  the radiation appears
to be random noise varying rapidly in intensity and its short term
characteristics can be affected markedly by the terrestrial ionosphere
three main sources of noise are apparent but none can be identified
with visual features  the great variability and spectral concentration
of the radiation suggests an origin in some form of plasma oscillation
in an ionized region having a critical frequency of about  see also
of
   /
4136
the variation of decimetre wave radiation with solar activity  a
statistical method is used to segregate the quiet component from
the slowly varing component of solar decimetre wave radiation in
the period  for this purpose the radiations at frequencies and have
been correlated with sunspot numbers sunspot areas and faculae  the
mean lives of the various radiations and activities have been estimated
and compared  there is an increase of life with decreasing radio
frequency  the life of radiation is about the same as sunspots but
measurements of the latter show some anomalies  the slowly varying
radiation flux is proportional to frequency in the range studied
the quiet sun flux has a small but significant variation with solar
activity the relative change being greater for smaller frequencies
the possibility that this variation may be associated with uncorrelated
local sources such as prominences is not entirely excluded
   /
4137
changes in amplitude of the day variation in cosmic ray intensity
during the solar cycle of activity  the amplitude variation is in
general agreement with the changes in solar activity assessed by
the sunspot number only for the years and  the poor correlation for
the years may be explained by the changes in the electromagnetic
conditions in interplanetary space during the solar cycle
   /
4138
on the increase in cosmic ray intensity and the electromagnetic state
in interplanetary space during the solar flare of feb  a detailed
analysis of the onset times of the increase in intensity is used
in the study of the electromagnetic state  the existence of deflecting
magnetic fields between the sun and the earth is demonstrated  a
probable mechanism is discussed whereby flare low energy cosmic ray
particles could be trapped and guided by a solar beam which could
also have caused the large magnetic storm observed two days after
the flare
   /
4139
geomagnetic latitude effect of the cosmic ray nucleon and meson components
at sea level from japan to the antarctic  preliminary report
on results of measurements made on board the ice breaker soya from
november to april  the effects of a cosmic ray storm in the antarctic
are described
   /
4140
a theoretical rate amplitude relation in meteoric forward scattering
   /
4141
observations of angle of arrival of meteor echoes in vhf forward
scatter propagation
   /
4142
the fading of long duration meteor bursts in forward scatter propagation
   /
4143
the phoenicid meteor shower  from radio observations at adelaide
six hours before peak activity the radiant coordinates are estimated
to be  the radio rate of measured on high sensitivity equipment is
much lower than that expected from visual rates of to reported to
later  see also of
   /
4144
sunspot and magnetic activity  unusual features of sunspot and magnetic
activity in the years and their effects on the performance and frequency
usage of some hf radio teletype circuits are examined
   /
4145
the swedish radio scientific solar eclipse expedition to italy  preliminary
report on observations of the solar eclipse of february
   /
4146
nonuniformity in the brightness of the suns disk during the eclipse
of june  the brightness distributions derived from british and norwegian
ionospheric measurements are presented so as to show their underlying
similarity  quantitative data for the most probable distribution
are given and a comparison is made with radio noise measurements
at during the eclipse
   /
4147
a survey of ground conductivity and dielectric constant in norway
within the frequency range of and  measurements were made using the
wave tilt method and a ground conductivity map of southern norway
has been prepared
   /
4148
on the theory of magnetic storms and aurorae  it is shown that the
nonmagnetic beam of ionized gas assumed in the chapman ferraro theory
is inconsistent with cosmic ray observations and that the main phase
of the storm cannot be explained in terms of a nonmagnetic beam
the arguments of chapman and cowling against the electric field theory
are discussed and shown to be invalid
   /
4149
statistical investigation of magnetic crochets at tamanrasset
   /
4150
sub audible geomagnetic fluctuations the observations of duffus and
shand have been extended to cover the frequency range of  records
obtained at a portable subsidiary station about miles from the main
station near victoria bc in the same mame magnetic latitude showed
no phase shift of the normal daytime oscillations
   /
4151
large amplitude hydromagnetic waves above the ionosphere  the hydromagnetic
wave velocity is calculated as a function of altitude  there
are two regions where the wave velocity changes very rapidly with
altitude and it is concluded that hydromagnetic waves above the ionosphere
have an amplitude greater than the geomagnetic fluctuations they
produce at the surface of the earth  see also of october
   /
4152
method of magnetic storm forecasting from the activities of flares
accompanied by solar radio noise outbursts  a statistical study indicates
that solar flares accompanied by radio noise bursts have a close
correlation with terrestrial magnetic storms  see also of february
   /
4153
on the magnetic clouds responsible for variations of cosmic ray and
geomagnetic field  discussion of the mechanism suggested by morrison
by which large ionized gas clouds carrying tangled magnetic fields
are emitted from the sun and modulate the galactic cosmic rays reaching
the earth  it is shown to be more probable that smaller magnetic
clouds are intermittently ejected from the sun and slowed down by
the interplanetary gas  the velocity of accompanying unmagnetized
streams is unaffected and the different velocities account for the
observed initial and main phases of terrestrial magnetic storms the
model also explains some solar cosmic ray phenomena
   /
4154
radio studies during the international geophysical year  studies
are discussed under five headings vertical soundings ionospheric
drift measurements backscatter radio noise and atmospheric studies
and rockets and satellites  the history program and organization
of the igy are briefly outlined
   /
4155
theoretical analysis of doppler radio signals from earth satellites
the analysis is briefly described and its application to the calculation
of the orbits of two satellites sputnik and explorer from isolated
observations made at one station is given
   /
4156
observations of the us satellites explorers and by cw reflection
the passage of satellites explorer and may be detected by the increased
signal strength of as a result of ionization from the satellite paths
see also of
   /
4157
continuous phase difference measurements of earth satellites  two
similar receivers are used operated from a common local oscillator
the phase meter compares the af tones from the two receivers  see
also of
   /
4158
on the interpretation of the doppler effect from senders in an artificial
satellite  the doppler effect is simply related to the angle of
incidence of the transmitted signal if the geomagnetic field is ignored
otherwise the relationship is complex and an investigation of the
actual ray paths is necessary even for the deduction of approximate
numerical values
   /
4159
the effect of the ionosphere on the doppler shift of radio signals
from an artificial satellite  application of snells law to a ray
passing through a spherically stratified ionosphere to a receiver
on the ground leads to a relation between doppler shift and angle
of incidence at the ground
   /
4160
high atmosphere densities  models of the upper atmosphere are modified
to allow for diffusion and other factors in order to conform to the
results obtained from satellite observations
   /
4161
distortion of the magnetic field in the outer atmosphere due to the
rotation of the earth  assuming a cavity surrounding the earth caused
by the earths revolution the equations of the fields imply a westward
shift of the dip equator in the outer atmosphere in agreement with
cosmic ray evidence
   /
4162
anomalies in ionosonde records due to travelling ionospheric disturbances
anomalies in ionosonde records of the f region during the passage
of travelling disturbances are classified into four main types  the
diurnal and seasonal variation of their occurrence is discussed and
it is suggested that the ion distribution at a height of governs
the type of anomaly observed  see also of
   /
4163
travelling ionospheric disturbances in the f region  data obtained
from april to march on the horizontal movements of the disturbances
are analysed for a single radio frequency  the monthly means of direction
show a seasonal change from in winter to in summer with a small
change in mean speed from to km min respectively
   /
4164
measurement of the ionospheric faraday effect by radio waves reflected
from the moon  continuous waves at were transmitted from belmar and
received at urbana after reflection from the moon  from to the change
in total electron content deduced from measurements made during the
night of january was about times the change computed for a parabolic
layer from vertical incidence recordings at the transmitter site
   /
4165
the effect of certain solar radiations on the lower ionosphere  an
electron density distribution in the d and e regions of the ionosphere
is computed  lyman alpha lyman beta the lyman continuum and x radiations
are considered  the resulting electron distribution is used to compute
parameters which may then be compared with data from rocket and longwave
radio experiments  in general there is good agreement between experimental
results and the values predicted by the model
   /
4166
on the ionospheric current system of the geomagnetic solar flare
effect  the analysis of magnetograms obtained at niemegk near berlin
between and shows that the sfe current system is independent of the
system and situated at a lower level  contributions to the geomagnetic
sfe apparently come from both the d and e regions  see also of taubenheim
   /
4167
the interpretation of changes in the e and f layers during solar
eclipses  results obtained during a series of eclipses support an
interpretation of ionospheric changes in terms of the response of
a chapman layer to the obscuration of a solar disk where localized
sources of ionizing radiation are superposed on a uniformly bright
background  an alternative hypothesis of a uniform disk and a complex
layer with two different species of ion does not adequately explain
observed characteristics  experimental results indicate that errors
due to layer tilts are probably not important  see also above
   /
4168
method of measuring ionospheric winds by fading at spaced receivers
current statistical methods of measurement are critically reviewed
and compared  as a result a method is suggested that may be less
laborious than the autocorrelation methods but of comparable accuracy
see eg of
   /
4169
on the bearing of ionospheric radio waves  systematic measurements
of bearings obtained by means of special df equipment of february
et al are analysed and fluctuations are interpreted with regard to
propagation modes and distance  when the great circle muf exceeds
the signal frequency the mean bearing coincides with the direction
of the transmitter aerial but deviates considerably when the great
circle muf falls below the signal frequency  the changes are attributed
to a major deviation from the great circle path combined with a final
scatter hop from continental land masses  deviation of anti podal
signal bearings are explained assuming that the signals follow paths
of low absorption night zones
   /
4170
an automatic recorder for measuring ionospheric absorption  ionospheric
absorption is deduced from the ratio of the amplitudes of singly
and doubly reflected vertical incidence pulses  the two pulses are
separated by adjustable gates and applied to two logarithmic amplifiers
followed by a difference circuit operating a chart recorder  in the
absence of a second reflection a local reference pulse can be used
the system being calibrated subsequently
   /
4171
low frequency reflection in the ionosphere  the transition from the
ionosphere to interplanetary space  report of a discussion held by
the royal astronomical society in london february including five
short talks concerning the solar corona zodiacal light radio echoes
from the moon earth satellite observations and af atmospherics
   /
4172
free air turbulence  measurements of the altitude distribution between
and of layers of turbulence made by means of a gustsonde incorporating
a vhf transmitter are analysed
   /
4173
thunderstorm charge separation  laboratory experiments show that
charge separation may arise from the collision between graupel pellets
and ice crystals from friction between ice formations at different
temperatures or with different amounts of contamination and from
the re solidification of a liquid layer in contact with ice
   /
4174
low latitude reflections from the aurora australis  observations
of radar reflections for the period march june are reported  records
of radar visual and geomagnetic observations for one day are compared
   /
4175
velocity of propagation of electromagnetic waves at audio frequencies
   /
4176
physical processes in contact erosion  a general survey of erosion
effects for relatively low voltages and currents
   /
4177
transistor voltage and current stabilizers  details are given of
a current generator and a voltage generator using transistors and
a zener diode  coupled together the circuits provide a stabilized
current supply of up to
   /
4178
electrical protection for transistorized equipment  semiconductor
diodes are used to limit excessive voltages accidentally placed on
telephone circuits
   /
4179
new batteries for the space age  a survey of short life electrochemical
batteries developed for extreme reliability at high discharge rates
under stringent operating conditions  the main characteristics of
recent types are given in tabulated form
   /
4180
short cut multiplication and division in automatic binary digital
computers  a modified short cut process is proposed and the application
of such procedures to restoring or non restoring division techniques
is discussed
   /
4181
a full binary adder employing two negative resistance diodes  this
adder provides outputs which are virtually in coincidence with the
input signal  a full adder is described using positive gap diodes
of the type described by reeves and cooke of which operate with pulses
   /
4182
tradic the first phase  a general report is given of the equipment
which was designed and built to test the feasibility of airborne
digital compters using transistors
   /
4183
an analogue computer study of the transient behaviour and stability
characteristics of serial type digital data systems  the transient
characteristics of sampled data computer systems incorporating a
holding circuit are examined with particular emphasis on the transient
response to a standard input step function
   /
4184
transistorized analogue digital converter  the analogue digital converter
described has a power consumption of less than and codes input
signals up to at a maximum sampling rate of inputs with errors not
exceeding the output is at the rate of digits  the volume of the
unit is in
   /
4185
a direct reading printed circuit commutator for analogue to digital
data conversion  the disk type commutator described supplies the
digital digital signal required for output equipment operation without
the need for supplementary coding or additional translation circuitry
to remove ambiguities
   /
4186
function tables in digital control computers  stored function tables
with appropriate interpolation techniques can be used with advantage
in digital control computers where there are limitations on space
and computing time eg the control loop of servo systems
   /
4187
a load sharing matrix switch  a matrix switch winding pattern has
been developed which allows the power from several pulse generators
to be combined in a single high power pulse to drive a computer core
type storage system  this pulse may be directed into one of a group
of outputs an example with outputs is given
   /
4188
miniaturization design techniques  the construction of an em relay
is described as an example
   /
4189
reliable printed wiring without hole pads  a plated hole technique
is described
   /
4190
an electronic transformer  the anode follower circuit is used as
a transformer in a cable system where signals are distributed from
a master generator to a number of separate displays  the load on
the source is negligible the voltage transformation is independent
of the impedance transformation both being controllable the cable
may be matched if necessary and the system bandwidth is inversely
proportional to the cable length
   /
4191
large signal behaviour of directly heated thermistors  part of a
study of thermistor circuits  part
   /
4192
temperature compensating networks  a generalized analytical design
procedure is proposed for the realization of two typical temperature
compensating bias networks employing thermistors for class b push
pull transistor amplifiers  a set of simple relations is derived
for evaluating the network component values and restrictions are
indicated on the choice of appropriate thermistors
   /
4193
the spherical coil as an inductor shield or antenna  the coil is
a single layer winding of constant axial pitch on a spherical surface
its properties can be expressed by simple formulae and can be used
to evaluate the shielding effect of a closed nonmagnetic metal shell
resonance effects are studied
   /
4194
applications of nonlinear magnetics  it is shown how saturable core
reactors may be used in such applications as counters timers voltage
and current references frequency multipliers firing circuits for
thyratrons and ignitrons pulse shaping circuits for magnetrons rectifying
circuits bistable flip flops frequency detectors and square wave
oscillators
   /
4195
minimization of components in electronic switching circuits  the
details are given of a method using boolean functions for designing
switching circuits using a minimum number of if diodes or transistors
   /
4196
some comments on minimum triggering signals  a theorem on the energy
transfer characteristics of a linear network is proved  see also
of july
   /
4197
the response of a network to a frequency modulated input voltage
mathematical treatment illustrating the relative simplicity of the
method of operational calculus
   /
4198
an exact theory of n component steady state operators for linear
circuits
   /
4199
unstable linear systems and the minimum phase condition  the relations
between transfer functions for unstable systems and the class of
minimum phase transfer functions are examined
   /
4200
the limits of the regions of stability of the normal state in certain
ferroresonant circuits  the unequal voltage distribution between
the two identical resonance circuits referred to in of may is explained
by periodic variations in coil inductance
   /
4201
multi gain representation for a single valued nonlinearity with several
inputs and the evaluation of their equivalent gains by a cursor method
   /
4202
radio engineering use of the cayley klein model of three dimensional
hyperbolic space  applications to the solution of network problems
are outlined  see also
   /
4203
some optimum four terminal networks having given input and output
shunt capacitances
   /
4204
optimum network functions for the sampling of signals in noise  transfer
functions are calculated for networks which maximize the ratio between
the average amplitude of n successive samples of the output signal
and the rms output noise and a continuous sample of the output
   /
4205
active band pass filter has sharp cut off  an adjustable rc af filter
having butterworth attenuation characteristics and octave cut off
slope is described  outputs of rms can be obtained without appreciable
harmonic distortion  the dynamic range exceeds db
   /
4206
on the discrimination of a synchronized oscillator against interference
accompanying the synchronizing signal  the response of the oscillator
to an interfering signal is investigated when the interference component
of the oscillator output is small  the response is found to be linear
and the discrimination is expressed analytically  the experimental
results are in good agreement with theory
   /
4207
simplified design of pulse forming networks  the network consists
of a five section capacitive circuit and a single layer continuously
wound tapped solenoid
   /
4208
designing transistor circuits switching dynamics  equivalent circuit
data for determining overall response time are tabulated for basic
transistor switches with an applied input step for the underdriven
condition  the overdriven case is also considered
   /
4209
transistor pulse generators for time division multiplex  point contact
transistor circuits to generate pulses in the microsecond range are
described together with means of frequency dividing and interlacing
pulse trains and their application to time division operation of
telephone transmission and switching systems
   /
4210
built up of large signals with elimination of reflections in magnetostrictive
storage lines by means of multicoil transducers  in german
with english summary  an ultrasonic storage delay line using transducer
coils and a stainless steel wire long has a capacity of decimal places
see of january
   /
4211
amplifier delay charts  the time delay in various types of amplifier
due to the network phase shift can be determined from the series
of charts given if the amplifier bandwidth and number of stages are
known
   /
4212
relating the nyquist plot to the root locus plot
   /
4213
high efficiency push pull magnetic amplifiers with transistors as
switched rectifiers  various circuits are considered in which the
efficiencies exceed and  they are particularly suitable where the
available power supply is limited
   /
4214
a simple transistor amplifier for energizing a hall multiplier
   /
4215
nonlinear distortion in transistor amplifiers at low signal levels
and low frequencies
   /
4216
transistor video amplifiers  the principles of design of iterated
video amplifiers using transistors are discussed in terms of a simplified
hybrid equivalent circuit  the design and performance of an experimental
television video distribution amplifier are described
   /
4217
polarization of a molecular beam by an alternating field with variable
amplitude and phase
   /
4218
nonlinear effects of the interaction of resonance fields in the molecular
generator and amplifier  analysis of a molecular oscillator with
an auxiliary field based on the polarizability of a quantum system
situated in two resonance fields  such a system can operate at two
frequencies which depend on the amplitude as well as the frequency
of the anxiliary field
   /
4219
susceptibility of the three level maser  the susceptibility presented
to a radiation field of frequency by the paramagnetic material is
calculated  the effect of the cavity reaction at the frequency is
considered  the line shape is shown to be drastically altered for
large amplitude driving fields
   /
4220
noise in maser amplifiers theory and experiment  the theoretical
treatment is based on an equivalent microwave circuit  the effective
input noise temperature of a reflection type beam maser was found
experimentally to be which is in agreement with theory  an upper
limit of for the beam temperature was deduced
   /
4221
quantum analogue of the ferromagnetic microwave amplifier  certain
resemblances between the modes of operation of the three level maser
and the ferromagnetic microwave amplifier are shown to be superficial
by constructing a quantum mechanical model of the latter device
it is shown that while establishment of a negative temperature for
two levels is essential in the three level maser it is inessential
in the analogue of the ferromagnetic amplifier which in essence depends
only on the time varying part of the density matrix
   /
4222
phase dependence of a ferromagnetic microwave amplifier  the phase
dependent operation of an amplifier using polycrystalline yttrium
garnet is shown experimentally
   /
4223
minimum noise figure of a parametric amplifier  with the aid of a
circulator the noise figure may be made to approach the minimum value
where is the pumping and the output frequency
   /
4224
a low noise nonlinear reactance travelling wave amplifier  results
obtained with an experimental model for using nonlinear capacitances
are given
   /
4225
a rectifier modulator with stable low carrier leak  the action of
a constant current ring modulator in which the input transformer
is replaced by high impedance valve circuits is analysed in detail
the theoretical analysis is confirmed experimentally using a carrier
frequency  stable carrier leak levels more than below the carrier
current from each source are possible
   /
4226
pulse modulation transmitted through a linearly modulated transit
time device  a discussion of basic principles with reference to the
serrodyne device and their application to frequency shifting computers
pulse duplexing and a multiple reflex pulse amplifier
   /
4227
new physical constants from dimensional analysis  three quantities
are formulated which represent constants of astronomy and classical
mechanics and of submicroscopic physics and which correlate phenomena
in electromagnetic quantum and classical physics
   /
4228
the special theory of relativity and the ether  datzeffs theory is
held to be quite untenable
   /
4229
theoretical problem posed by an extended model of the electron and
the proton  arguments about the stability and relativistic properties
of elementary particles taken as extended sources of em fields are
considered
   /
4230
the physical interpretation of mean free path and the integral method
an extension of previous theoretical work on electron transport in
solids  see of january
   /
4231
generalization of the variation principle in theory of electrical
conductivity
   /
4232
theory of the anomalous skin effect in normal and superconducting
metals  the current density in a normal metal in which the electric
field varies over a mean free path is derived from a quantum approach
in which use is made of the density matrix in the presence of scattering
centres but in the absence of the field  the method is applied to
superconductors
   /
4233
anomalous skin effect in a magnetic field  a classical and quantum
mechanical derivation of cyclotron resonance in metals is given
the quantum derivation yields the same result as the classical calculation
except in the limit of low quantum numbers or high magnetic fields
   /
4234
noise and electron temperatures of some cold cathode argon discharges
noise temperatures at were compared with the corresponding electron
temperatures for the positive columns of some cold cathode discharges
in a they were found to be in close agreement  the discharges gave
reproducible results and are recommended for use as noise standards
   /
4235
the townsend discharge in a coaxial diode with axial magnetic field
an approximate theory of the striking characteristics of coaxial
cylinders in an axial magnetic field taking into account the effects
of elastic collisions of the electrons  measurements in the pressure
range mm hg are in general agreement with the theory
   /
4236
the fresnel biprism in electron optics influence of the size of the
source effect of a periodic voltage applied to the wire of the biprism
   /
4237
contribution to the theory of transition radiation  the transition
radiation and cherenkov radiation produced when a charged particle
moves in succession through two media of different dielectric and
magnetic properties are considered  the cases in which one medium
is a vacuum are discussed in detail
   /
4238
apparatus for producing plasma beams  a brief account is given of
simple apparatus and experiments conducted with it
   /
4239
effect of electron exchange on the dispersion relation of plasma
oscillations  the dispersion relation is derived from a canonical
transformation slightly different from that of bohm and pines  a
correction factor is introduced for electron exchange effects but
agreement between theory and experiment is not thereby improved
   /
4240
model for the surface potential barrier and the periodic deviations
in the schottky effect  the model is based on the quantum mechanical
calculation by bardeen on the form of the potential at the surface
of a sodium like metal and the analysis of sachs and dexter on the
quantum limits of the image face theory  the periodic deviations
are recalculated and results compared with previous theory and experiment
   /
4241
remarks on spin wave theory for the ferromagnetic exchange problem
a theory is developed which is essentially equivalent to the bloch
bethe van kranendonk formalism see  thermodynamic properties below
the curie point are fully treated
   /
4242
the production of very homogeneous axially symmetric magnetic fields
inhomogeneity in the magnetic field between two pole pieces is due
to irregularity in the pole piece and to boundary effects which may
be reduced by current shims in the form of compensating coils
   /
4243
electromagnetic energy transfer  methods of calculating and measuring
the flow of electromagnetic energy are compared and contrasted  the
differences between the low frequency and high frequency approaches
to energy flow problems are discussed and suggestions are made to
ease the difficulties in the way of students and teachers faced with
these apparently irreconcilable differences
   /
4244
microwave zeeman effect and theory of complex spectra
   /
4245
dispersion  the effect is discussed in terms of group and phase velocities
and applied to waveguides cables circuits and the ionosphere
   /
4246
the effect of fluctuations on the diffraction patterns of a focusing
system  general formulae are derived for the average distribution
of intensity and the distribution of fluctuations in a diffraction
pattern when fluctuations are present in the incident wave  limiting
cases of large and small fluctuations are considered
   /
4247
transmission characteristics of inclined wire gratings
   /
4248
on resonance in infinite gratings of cylinders
   /
4249
on scattering and reflection of electromagnetic waves by rough surfaces
   /
4250
diffraction of microwaves by tandem slits
   /
4251
induced and spontaneous emission in a coherent field  the resonant
interaction between a coherently oscillating radiation field and
a number of similar atomic systems coupled to the field through their
electric dipole moments is analysed quantum mechanically  distinction
is drawn between coherent and incoherent parts of the energy  terms
corresponding to induced and spontaneous emission are identified
and it is shown that the latter includes both coherent and incoherent
components  special situations related to masers and to the coherence
of spontaneous radiation are discussed
   /
4252
theory of cyclotron resonance  treatment of cyclotron resonance in
a metal in an inclined magnetic field and in a parallel magnetic
field with arbitrary electron reflection
   /
4253
theory of cyclotron resonance in metals  an investigation of the
influence of field strength and temperature on the surface impedance
of a metal in rf and constant magnetic fields parallel to the surface
   /
4254
the skin effect and ferromagnetic resonance  mathematical analysis
of normal and anomalous skin effect in metals under conditions of
ferromagnetic resonance
   /
4255
polarization of a molecular beam by an alternating field with variable
amplitude and phase  equations are derived and an exact solution
is given for the case when the frequency of the applied field is
the same as that of the molecular transition  approximate solutions
are obtained for slow and rapid variations in the amplitude and frequency
of the field during the time of transit of the molecular beam
through the resonator cavity
   /
4256
measurement of microwave absorption in binary gaseous mixtures
   /
4257
absorption and refraction of some polar gases as a function of pressure
at microwave frequencies
   /
4258
optical detection of hyperfine transitions of caesium atoms  report
of measurements made at frequencies of and to detect hyperfine zeeman
transitions in cs
   /
4259
microwave apparatus for the measurement of the refraction dispersion
and absorption of gases at relatively high pressure
   /
4260
a microwave spectrometer for the study of free radicals  description
of apparatus suitable for the study of short lived molecules in the
gas phase and operating in the frequency range
   /
4261
micromodulator a device for measuring the intensities of microwave
absorption lines  by means of a small electromagnet and power supply
a free electron resonance is utilized to provide a standard comparison
line at any frequency up to
   /
4262
on force free magnetic fields  the assumption that the lorentz force
vanishes in cosmic magnetic fields which occur in regions of low
density is discussed
   /
4263
observations of discrete radio sources at a frequency of  an interferometer
system with long integration times is used to determine the
flux densities of eleven sources relative to cygnus a
   /
4264
the spectra of radio stars  by considering all available measurements
on the flux density of cassiopeia a it is concluded that its spectrum
obeys a simple power law  using this law the spectra and special
indices of radio stars are derived including cygnus a virgo a and
taurus a
   /
4265
on the nature of the cygnus x radio source as derived from observations
in the continuum and at the hydrogen line frequency
   /
4266
results of a survey of galactic radiation at  the results covering
most of the sky north of are presented in the form of a contour map
together with a list of reliably observed sources and regions with
their features
   /
4267
a new type of pencil beam aerial for radio astronomy
   /
4268
a theoretical study of errors in radio interferometer type measurements
attributable to inhomogeneities of the medium
   /
4269
duration and bandwidth of short lived transients in solar noise
histograms of single frequency measurements made at and a table of
results for a two channel receiver covering the band are given  see
also of
   /
4270
the variation of ionization along a meteor trail  results are described
of investigations using two spaced receivers to observe radio echoes
from faint meteor trails  the mean ionization curve is much shorter
than predicted by present theory and the rise to maximum electron
density more rapid than expected
   /
4271
radio noise from meteors  a note of attempts made in usa to detect
meteor noise at frequencies of and  no emission from meteors was
detected  itt is concluded that the efficiency of conversion of the
kinetic energy of meteors to radio energy is less than per unit bandwidth
   /
4272
analysis of meteoric body doppler radar records taken during a germinid
shower period  the prevailing wind speed in the region has been determined
using a cw doppler radar and three station pulsed radars operating
simultaneously at about and  the body doppler frequency and its fluctuations
indicate a wind speed of and a turbulence scale of about on
the night of december
   /
4273
a cosmic ray increase related to solar activity  a large increase
in cosmic ray activity measured with telescopes of small solid angle
was observed to accompany a sustained increase in the f layer critical
frequency during the period september february
   /
4274
temperatures and electron densities in flares as derived from spectroscopic
data
   /
4275
type emissions and the origin of cosmic rays associated with chromospheric
eruptions
   /
4276
the origin and maintenance of geomagnetism its secular variation
and its inversions
   /
4277
orbital behaviour of earth satellites  sources of perturbation are
considered with particular attention to the effect of the oblateness
of the earth for which an analysis is developed n and recent contributions
are reviewed
   /
4278
radio doppler measurements on the russian satellites at the national
standards laboratory  from observations made on the transmission
at one station values for the period n and other orbit parameters
were deduced using simple methods
   /
4279
sputnik last days in orbit  the satellite was tracked by using a
cw reflection technique see of june and was found to break up in
a complex manner over a period of days  possible break up mechanisms
are suggested
   /
4280
effect of air drag on the orbit of the russian earth satellite comparison
of theory and observations
   /
4281
measurement of cosmic radiation on the sputnik  preliminary results
obtained by means of two independent recording instruments located
in the second artificial earth satellite are shown graphically  a
min increase in intensity was recorded on november above latitude
   /
4282
radio scintillations of satellite  graphical recordings of the signal
from satellite are reproduced  the scintillations observed are correlated
with scintillations of cosmic rf sources recorded during the same
period  results indicate that the ionospheric irregularities responsible
for the scintillations must lie below km  corresponding recordings
from satellite show significantly less scintillation activity at
perigee than on preceding and following days
   /
4283
some effects of the fine structure of the ionosphere on transmission
received from the russian earth satellite  anomalies in doppler observations
of the satellite are discussed  it appears practicable to make
a detailed study of the lower boundary of the f region by an analysis
of doppler frequency discontinuities in conjunction with accurately
known orbit parameters
   /
4284
on the results of the electron concentration determinations in the
external region of the ionosphere made on the basis of radio signals
from the first sputnik  brief description of the method of observation
of radio signals from the satellite to determine the exact time of
its rising and setting  calculated values of electron density range
from electrons cm at to electrons cm at
   /
4285
rocket measurements of electron concentration in the ionosphere by
means of an ultra short wave dispersion interferometer  investigations
have been carried out since at heights up to using rockets equipped
with transmitters operating at and  signals were recorded at the
ground by two different oscillographic methods  results indicate
that the true height of f layer reflections is km lower than the
effective height recorded by an ionospheric sounder
   /
4286
apparent saturation in f layer  at sunspot numbers near there is
a departure from the linear relation with f layer critical frequency
which is attributed to a combination of high sunspot numbers and
local summer daytime conditions
   /
4287
horizontal ionospheric drifts in the f region at equatorial latitudes
systematic measurements of drift made at waltair india by the spaced
receiver method from february to january are analysed  the component
is invariably higher than the ns component  the prediction of phase
reversal of drift at a latitude of is confirmed  see also of july
and below
   /
4288
similarities in the characteristics of solar radiation at cm and
in the far ultraviolet  values of the activity index based on e layer
data for slough have been correlated for a ten year period with the
monthly mean value of solar rf noise flux measured at ottawa  the
close correlation found and results of an analysis of eclipse data
support the conclusion of denisse and kundu of
   /
4289
equatorial spread f and magnetic activity  analysis of data for ibadan
nigeria for the years and shows that the incidence of spread f on
international quiet days is higher than that on international disturbed
days
   /
4290
diurnal variation of deviative absorption in the f region of the
ionosphere  note of absorption measurements near the critical frequency
daytime reduction of deviative absorption is ascribed to thermal
expansion of the f layer
   /
4291
anomalous variation of total absorption of radio waves reflected
from the f region of the ionosphere around midday  observations made
at banaras using frequencies higher than f layer critical frequency
show two maxima one before and the other after local noon  the first
maximum has been attributed to thermal expansion of the f region
the effect of which is normally observed before midday the second
coincides with the usual maximum of total absorption observed at
lower frequencies after midday
   /
4292
investigation of horizontal drifts in the e region of the ionosphere
in relation to random fading of radio waves  measurements of e region
wind velocities v and frequency of fading n were made at and  the
linear relation which is in agreement with theory is deduced
   /
4293
ball lightning and thermonuclear reactions  it is suggested that
ball lightning is formed by radiocarbon due to the action on atmospheric
nitrogen of thermal neutrons liberated by lightning discharges  see
also of
   /
4294
height distribution of the red auroral line in polar aurorae  luminosity
curves along vertical cross sections of auroral forms recorded by
means of a photoelectric photometer are analysed
   /
4295
some observations of aurora using a low power frequency modulated
radar  an experimental cw radar is described which provides information
on range and radial motion of auroral echoes  a histogram of the
range distribution of echoes from reflecting areas north of ottawa
shows a maximum at
   /
4296
polarization of atmospherics  comment on of august and authors reply
   /
4297
whistlers in the antarctic  observations made from at scott base
showed considerable activity including bonks tweeks long and short
whistlers and periods of strong sferics but no dawn chorus  it is
probable that the whistlers are propagated from lower latitude regions
first along the appropriate magnetic flux line and then by ionospheric
reflection
   /
4298
automatic recorder of the waveforms of atmospherics  description
with circuit diagrams of component units of film type recording equipment
in operation since and of similar design to that described earlier
of
   /
4299
the exploration of space by radio  a detailed review of different
branches of the subject
   /
4300
transistors reduce relay servo size
   /
4301
new type constant voltage rectifier  a constant voltage supply for
use as a floating battery power source is described its output rating
is at
   /
4302
a high speed rotary switch and some applications  the general requirements
of high speed switches are discussed with particular reference
to applications in information sampling systems  details and applications
of a rotary switch permitting rotational speeds of up to rev min
are described
   /
4303
the principle of stabilization of constant impedance devices n and
its application to a transistor power supply  the useful operating
range of a shunt type voltage regulator is expressed in terms of
a utilization coefficient  general relations derived are applied
to a two transistor circuit of the type described earlier of november
particularly suitable for stabilization of valve heater supplies
   /
4304
computing bit by bit or digital computers made easy  an introduction
to the subject with explanations of the specialized terminology
   /
4305
can machines think  a general survey of the capabilities and limitations
of digital computers
   /
4306
computers and automata  recent developments in the field of automata
and non numerical computers are reviewed some typical machines including
games playing machines are described  a comparison is made between
the operation of computers and of the brain
   /
4307
fundamentals of digital computer programming  the process of programming
is explained in relation to a typical but simplified stored programme
computer using basic instructions  elementary arithmetical and logical
computation are illustrated  the ability of the computer to modify
its own programme is demonstrated
   /
4308
influence of programming techniques on the design of computers  new
techniques r are discussed which take advantage of the high speed
checked operation of the computer to perform the routine work of
programming
   /
4309
analogue digital computers a comparison  the operation of analogue
computers is described  the problem of simulation in real time is
used as a basis for comparing analogue and digital computers in respect
of speed accuracy convenience  the mathematical operations discussed
include addition subtraction multiplication division evaluation of
polynomials and other functions extraction of square roots and solution
of differential equations
   /
4310
the system design of the ibm type computer and  attention is directed
specially to the new features of this machine which include improved
arithmetic and logical facilities and the control of the extensive
input and output arrangements directly from the stored programme
bit instructions cover distinct operations
   /
4311
engineering description of the ibm type computer  a detailed description
is given of this high speed computer for large scale scientific work
a complete installation includes analytical control unit es storage
unit magnetic tape and magnetic drum readers and recorders punched
card reader alphabetic printer punched card recorder power distribution
unit and power supply unit  a note on maintenance is included  see
also above
   /
4312
the arithmetic element of the ibm type computer  a storage circuit
giving a delay is described its output is at either or  used in conjunction
with direct coupled diode switching this arrangement leads to
simplifications in shifting registers and in performing division
and testing for zero in the accumulator
   /
4313
the swac national bureau of standards western automatic computer
design features and operating experience  this high speed computer
uses a williams tube main storage system an auxiliary magnetic drum
storage system and punched card input and output systems and  a review
is presented of problems solved by the computer during the preceding
year  for a less detailed account see and
   /
4314
the design and construction of a high speed electronic differential
analyzer
   /
4315
improvement of an iteration process suitable for automatic division
electronics computers having n  organ rf division are provided with
a subroutine for the computation of reciprocals  an improvement of
this subroutine is proposed which permits a reduction of about in
the number of operations without affecting the accuracy
   /
4316
use of a computing machine as a mechanical dictionary  the time required
to locate a stored word is reduced by applying binary division principles
in the searching process
   /
4317
industrial uses of special purpose computers  an account is presented
of the analysis of a simple machine control problem and the design
of a suitable special purpose computer to perform the task  economic
factors are also briefly considered
   /
4318
an method for synthesizing sequential circuits  an theory is developed
from design procedures suggested by huffman and moore enabling intricate
relay systems to be built up from an initial dias  by successive
application of simplifying reductions a unique circuit is finally
obtained
   /
4319
a nonlinear resistance capacitance circuit  an amplifier in a negative
feedback loop is used to provide the nonlinear resistance in an analogue
equipment representing air pressure variations
   /
4320
a photoelectric analogue computer for investigating the dynamic behaviour
of linear systems  apparatus is described for determining the
output function of a linear system such as an amplifier or servomechanism
when the input and transfer functions are known  the two known
functions are represented by appropriately shaped apertures in diaphragms
interposed between light source and photocell the mechanical system
used to produce the required continuous variation of the input function
is described in detail
   /
4321
high density tape recording for digital computers
   /
4322
standardization of electronic components  a survey with particular
reference to the activities of the international electrotechnical
commission
   /
4323
the impedance of chokes resistors and capacitors at high frequency
analysis indicates that in order to represent the impedance variation
of cylindrical inductors resistors and capacitors at frequencies
above the first resonance point equivalent circuits are needed combining
a ladder network with simple parallel or series networks nonuniform
field distribution along the component can then be taken into account
the validity of the theory is confirmed by reference to measurement
results shown graphically  the effect of an earthing lead on a lead
through capacitor is demonstrated
   /
4324
contact noise  composition resistors is considered as consisting
of a number of parallel circuits each containing an equal number
of particles and the same number of contacts of equal resistance
it is shown that the noise energys of such a homogeneous system is
equal to that of a single contact and that for a given gradient of
the applied direct voltage it is determined by the degree of dispersion
and the specific resistance of the conductor material  expressions
are also derived for heterogeneous systems and imperfect contacts
   /
4325
printed resistors  preparation of resistors by injection moulding
is described  the effect of ink composition and the printing and
curing processes on the resistor characteristics are described
   /
4326
magnetic pulse modulators  mathematical analyses are given of and
charged series type saturable reactors for generating pulses in radar
systems  automatic core resetting is achieved  the production of
pulses of duration and the prevention of parasitics in the output
are discussed and a circuit is described enabling the thyratron cathode
in a charged modulator to be operated at ground potential
   /
4327
a multistable transistor circuit
   /
4328
proof of a theorem on the equivalence of two pole networks with only
two types of impedance element
   /
4329
theorem on the reactive energy in an electric dipole in a state of
variation  analysis is based on differentiation of the operational
impedance  a simple formula is derived giving the instantaneous difference
between the stored magnetic and electric energy
   /
4330
a step by step method for designing waveguides and oscillatory systems
   /
4331
some fundamental properties of networks without mutual inductance
elementary methods not involving determinants are used to prove theorems
on the voltage and current gains obtainable from a resistance network
the results are used to determine properties of general networks
without mutual inductance rc networks are investigated by a method
simpler than that
   /
4332
synthesis of ladder networks to give butterworth or chebyshev response
in the pass band
   /
4333
ladder networks with similar quadripole sections  formulae for the
section input and output currents and voltages and input impedances
are derived directly from kirchhoffs laws using determinants
   /
4334
on node and mesh determinants  an extension of the analysis presented
by seshu
   /
4335
initial transients in some special passive networks with amplitude
and frequency modulation  it is shown that for multistage selective
circuits there is an optimum coupling for which the output corresponding
to unit step input is aperiodic and free from overshoot  the performance
of two frequency shift circuits is studied and the existence of an
optimum ratio of shift to keying frequency is demonstrated  a formula
is derived for calculating distortion factor for two circuit band
pass filters with
   /
4336
new filter theory of periodic structures  theory for linear passive
quadripoles is developed in terms of characteristic reflection and
transmission factors which can be specified by references to the
standing wave pattern on lines connected to the input and output
the relations between these factors and the usual circuit constants
particularly the image function of symmetrical circuits are studied
the method is illustrated by examining multisection structures combining
quadripoles and loss free lines  the uses of these characteristic
factors leads to major simplifications in dealing with loss free
structures where most of the work can be done graphically
   /
4337
a ten kilowatt low pass filter  the filter is designed for use in
the aerial feed lines of transmitters working in the frequency range
and discriminates by about against any frequencies in the television
band which may be present as harmonics  in measuring the effectiveness
of the filter account must be taken of radiation from sources other
than the aerial
   /
4338
a piezoelectric high pass filter  a lattice filter is considered
whose special feature is the use of transformers in its arms with
crystals included in the secondary circuits  the main parameters
of the filter are determined and formulae are derived for calculating
the resonances and antiresonance frequencies of the arms  a method
is proposed for designing the filter elements and for calculating
its basic loss  the experimental curve of a filter designed in this
manner shows a sharp cut off
   /
4339
a high q rc feedback filter  description of the design and construction
of a acceptor filter which will maintain a of stable to within over
one hour and a of to within over considerable periods  the circuit
uses a twin t rejector filter in the negative feedback path of an
amplifier
   /
4340
a voltage controlled attenuator  a three stage voltage controlled
germanium diode attenuator is described  transmission may be varied
over a range exceeding decibels by a control signal  push pull operation
is discussed and various applications are suggested
   /
4341
an s band variable attenuator for high power working  the description
is given of a waveguide insertion attenuator in which the loss in
r f power is produced by the action of a column of water flowing
in a glass tube mounted in the waveguide continuous variation of
attenuation being obtained by adjustment of the water column height
resonance effects in the water column are exploited by choosing the
cross sectional dimensions of the glass such that an optimum attenuation
per unit length of tube is obtained  experimental results are given
for a model covering the range the input being at any setting and
over the greater part of the range  satisfactory operation has been
achieved in an evacuated test system fed by a magnetron delivering
peak power at a wavelength of  various modifications in design are
suggested for use with higher mean powers
   /
4342
the graphs of active networks  results obtained previously are used
to develop the properties of the graphs of linear networks including
valves and transformers
   /
4343
linear and nonlinear effects in reactance and oscillator circuits
the analysis presented of the behaviour of a reactance valve in various
circuits is based on an expression for the anode current containing
terms up to the third degree in trid and anode voltages  two nonlinear
effects are considered the primary effect of the curvature in the
valve characteristic and the secondary effect due to the presence
of harmonic components in the applied signal  these were also investigated
experimentally and the results are presented graphically  a circuit
for reducing the effect of nonlinearity was also investigated
   /
4344
stability of oscillation in valve generators  a comprehensive theory
of stabilitys is developed which is applicable to a large class of
harmonic oscillators  the paper is concerned mainly with the terminal
regenerative type of oscillator with grid leak bias but the analysis
applies also to circuits with fixed grid bias and to terminal oscillators
all known forms of instability appear as special cases of the
general theory and some new forms are predicted  stability is determined
by the nature of the roots of a characteristic equation and stability
criteria are obtained in the form of inequalities between the parameters
of the amplifier and feedback network  a modified form of nyquist
locus diagram can also be used  when the feedback network is symmetrical
with respect to the oscillation frequency the characteristic equation
can be factorized to give independent criteria for frequency and
amplitude stability  hysteresis effects and periodic instability
are analysed in detail  in addition to the general treatment specific
forms of the various parameters which appear in the stability criteria
are worked out for a three halves law amplifier with a semi linear
or exponential grid current characteristic  quantitative experimental
confirmation is provided
   /
4345
effect of electrical fluctuations on a valve oscillator  the effect
of slow normal fluctuations is considered  expressions are derived
for the one dimensional probability density functions for amplitude
and phase  an approximate method is shown for calculating the correlation
functions for amplitude and phase variations
   /
4346
the frequency response analysis of nonlinear systems  if the waveform
at the input to the nonlinear elements in the system is approximately
sinusoidal the analysis may be carried out on the assumption that
all harmonics generated by the nonlinear elements can be ignored
analysis of on off control systems on this basis gives results within
about of the exact solutions for both transient and steady oscillations
   /
4347
synthesizing crystal stability  the output from two crystal oscillators
combined to give a beat frequency is squared and triggers a blocking
oscillator producing a pulse which is used to quench a tunable oscillator
the tunable oscillator locks to harmonics of the signal
   /
4348
an electromechanical stabilizer of the frequency of a klystron  in
the method proposed a portion of the klystron output is applied to
a cavity resonator the natural frequency of which is modulated by
a separately excited vibrating diaphragm  the output of the resonator
is detected amplified and through a phase detector applied to the
klystron reflector  the theory of the method is discussed and its
accuracy is determined  a comparison with the resonance frequency
of the absorption line of ammonia has shown that the relative frequency
error of the method is of the order of
   /
4349
subaudio oscillator tunes to cycles  a beat frequency oscillator
using carrier frequencies of about provides an output of up to constant
within over the frequency range with per hour drift and distortion
the need for low frequency amplification is avoided by the use of
a high level mixer circuit consisting of two se rectifiers with balancing
adjustment to eliminate the d c component
   /
4350
some transmission line devices for use with millimicrosecond pulses
a phase inverter impedance transformers and a valve heater isolating
transformer are described all comprising coaxial cable sections
   /
4351
generation of harmonics of a given fundamental  theory and experimental
results are given for a frequency multiplier based on use of a c
r tube in which a ribbon beam is deflected across a metal target
with an appropriate profile  suitable beam forming structures are
described
   /
4352
noise in u h f amplifiers  general noise effects in u h f amplifiers
of any type are considered  relations between the noise parameters
are established using the method of the transfer of the current generators
proposed previously  general expressions for the noise factors
are derived and the minimum number of noise parameters required to
characterize a circuit is deter mined  a concept of partial noise
parameters is introduced
   /
4353
a negative impedance converter for use as a two terminal amplifier
a specified stable negative impedance may be generated by connecting
a positive impedance between the output and input of an amplifier
possessing a high degree of negative feedback  an amplifier suitable
for use in transmission line systems is described
   /
4354
etched wiring simplifies magnetic amplifier design
   /
4355
active networks  deals with circuits including valves transistors
and other devices  there a sections on the principles of analogue
computers servo systems and wave shaping circuits as well as on general
aspects of amplifiers and oscillators
   /
4356
the correction of observational data for instrumental bandwidth
the formula relating t readings instrument having t apparatus function
to th true values of an observed function is stated  a three point
interpolation operator can be chosen to simulate the spreading action
of a class of functions  under certain conditions the interpolation
operator has an exact inverse which when applied to gives a function
which is a better approximation to  the accuracy obtained is discussed
effect of the method on the standard errors in the measurement is
found
   /
4357
electromechanical analogies  a discussion of the physical significance
f various analogies and of circuit concepts and terminal representation
in mechanics
   /
4358
state of research on photoelectricity  a survey is presented of research
since references
   /
4359
velocity of light from the molecular constants of carbon monoxide
from infrared spectroscopy measurements the value of is deduced for
the velocity of light with a standard deviation of  a short account
of the work is given in
   /
4360
simple color computer gives tristimulus values  trichromatic coefficients
or the c i e colour specification system are automatically computed
on a simple analogue machine
   /
4361
an interesting phenomenon observed on some dielectrics  a glass tube
either empty or containing a polar liquid or a metal rod rotates
continuously when placed in an inhomogeneous electric field of sufficient
strength if the electrodes and part of the tube are immersed in
carnauba wax or a higher alcohol stearic acid palmitic acid or xylol
   /
4362
field dependent conductivity in nonuniform fields and its relation
to electrical breakdown  a method is given for calculating the resulting
field distribution when the conductivity is a function of the field
strength  this is applied to a point plane electrode system in an
amorphous solid with the assumption that the conductivity at low
field strengths is electronic and that the conductivity at high field
strengths is described by a relation due to frohlich  the results
show that for polymethylmethacry late with average fields of the
order of the reduction in maximum field strength from that calculated
for constant conductivity can be a factor of five or more the magnitude
of the reduction depending on the degree of non uniformity of the
field  various other insulating materials are also discussed
   /
4363
study of gyromagnetic resonance in the penning gauge  conditions
in the penning gauge are particularly favourable for studying r f
radiation resulting from gyromagnetic resonance of electrons  both
longitudinal oscillations thermal agitation electrons involved resulting
in accumulation in the anode planes  the presence of plasma has an
important effect on the potential distribution introducing a radial
electric field  the equations of electron motion are established
some particular solutions indicate the possibility of a circular
path in the anode plane with an angular frequency about half the
gyrofrequency  with values of magnetic induction between and radiation
at decimetre wavelengths was produced  measurements of the radiation
are described  investigation of the complete spectrum emitted indicates
that coherent oscillations may occur  the results are compared with
those of other workers
   /
4364
influence of light on the mechanism of gas discharges  results of
previous experimental work are reviewed  the variation of the discharge
current with the intensity and frequency of the incident light and
in particular the reversal of this current variation in a certain
voltage range are interpreted in terms of space charge effects
   /
4365
the mechanism of high field electron emission from tarnished metal
surfaces  a theory of field dependent thermal emission is proposed
which takes into account the existence of patch fields due to variation
in work function over the surface
   /
4366
numerical ray tracing in electron lenses  corrections are suggested
to liebmanns formulae for tracing paraxial rays a more accurate method
is developed applicable also to marginal rays and is compared with
methods suggested by other workers  the use of the constancy of the
wronskian determinant as a criterion of accuracy of paraxial ray
tracing is discussed
   /
4367
effect of space charge on the propagation of intense beams of charged
particles  a review  about a third of the references given are to
russian work
   /
4368
a method of finding a large class of electrostatic and magnetic fields
for which the solutions of the fundamental equation of electron optics
may be expressed in terms of known functions  exact solutions of
equation are of great interest for various types of e s and magnetic
fields  until recently such solutions were known only for a very
limited number of cases  grinberg in particular indicated a class
of fields for which the trajectories of electrons are expressed in
terms of cylindrical functions  solutions are now found for a much
larger class of fields
   /
4369
velocity distribution of electrons in presence of an alternating
electric field and constant magnetic field  two cases are considered
theoretically the electric field varies sinusoidally and te variation
is amplitude modulated  case is of interest in the investigation
of ionospheric crossmodulation  the effect of collisions between
electrons is taken into account
   /
4370
resonant cavity measurements of the relative permittivity of a d
c discharge  measurements at and on low pressure d c discharges in
a mixture of hg vapour alone  decrease of permittivity with increase
of discharge current was noted in all cases  in case the cavity q
factor exhibited a minimum at a value of discharge current depending
on the resonance frequency this is attributed to electron resonance
theory of the method is given
   /
4371
general theory of magnetic masses at rest and in movement  theory
is presented based on the analogy with electric charge
   /
4372
magnetostatics with ferromagnetic materials  a variational principle
is formulated and proved in the theory of ferromagnetic materials
in the field of electric currents  a direct method is developed for
investigating magnetic fields in the general case of a nonlinear
dependence of permeability on magnetic field strength
   /
4373
comments on the nonlinear electrodynamics  some solutions of the
equations presented earlier are examined
   /
4374
description of the electromagnetic field by means of matrices  the
properties of matrix tensors are briefly considered and the quantities
characterizing an e m field are then expressed in matrix form
   /
4375
note on plasma electron oscillations  brief report of the results
of experiments on hot cathode discharges in hg vapour or ar at pressures
of the order of and discussion of their relation to the work of wild
   /
4376
the perturbation of an electromagnetic field by small deformations
of a metal surface  a general expression is derived for the perturbation
due to the deformation  if the deformation is slight this perturbation
can be found by the usual method of quadratures  the method is applied
to the problem of the diffraction of a plane wave at a step the height
of wich is small compared with  from this the well known formulae
of rayleigh for reflections from small and smooth irregularities
are easily derived
   /
4377
study of the local electromagnetic field at the junction of three
dielectric media  analysis is given for the case of three media with
a common edge
   /
4378
a diffraction problem  analysis is presented for the case of a plane
wave incident normally on an infinitely long perfectly conducting
strip
   /
4379
scattering of electromagnetic waves from a lossy strip on a conducting
plane  an examination is made of the error introduced in the analysis
of radiation and propagation problems by assuming perfect conductivity
in media such as the ground which are in fact imperfectly conducting
the result of the approximate calculation is compared with that of
an exact calculation involving elliptic wave functions  for the approximation
to be permissible the surface impedance o the lossy regions
should not exceed times the impedance of free space
   /
4380
hydromagnetic waves in ionized gas  the equation representing the
field in a moving isotropically conducting medium is discussed and
expressions are derived for the velocities of the ordinary extraordinary
and waves for gas pressures much less than and much greater than
the magnetic pressure
   /
4381
new technique for high resolution microwave spectroscopy  spectral
lines of width substantially less than the doppler width are produced
by containing the gas in a pillbox shaped cavity of height about
and diameter large compared to
   /
4382
the zeeman effect in ammonia microwave spectra  the zeeman effect
was investigated experimentally using magnetic fields up to oersted
results indicate that the line shows a change from the zeeman effect
to the paschen back effect at field strengths near oersted
   /
4383
theory of the nernst effects in ferromagnetic metals  on the basis
of a two band model with one band nearly empty and the other nearly
fully occupied theory for the nernst effect can be derived simply
from that for the hall effect
   /
4384
the hall effect and related phenomena  a brief review is presented
of recent work on the theory of the hall effect in ferromagnetic
in strongly paramagnetic and in semiconducting materials  practical
applications of the effect such as in the power amplifier are also
mentioned
   /
4385
reliability of atomic masses in the chromium germanium region  discrepancies
between atomic mass values obtained from transmission data
and those obtained by mass spectrometer methods are discussed  the
mass spectrometer values for may be in error but those for the other
elements from are considered to be accurate
   /
4386
lunar occultation of a radio star and the derivation of an upper
limit for the density of the lunar atmosphere  brief report of observations
made at cambridge england of the passage of the moon cross the
large diameter radio source in gemini  wavelengths of were used
   /
4387
chord construction for correcting aerial smoothing  a graphical method
of correcting for aerial smoothing in radio astronomy simpler and
no less accurate than methods described previously
   /
4388
the influence of noise on radar meteor observations  an experimental
investigation has been made of the minimum detectable echo power
from meteor trails using radar equipment with incoherent detection
for optimum signal noise ratio the pulse width must exceed the width
of the tube spot  extraterrestrial noise is predominant receiver
noise figure being of second order importance  variations in the
effective aerial temperature introduce corresponding variations in
the observed meter rate  using artificial echoes a minimum signal
noise ratio of is found to be necessary for detection the most important
parameter is the total received signal energy  it is not likely that
meteors of smaller size can be made observable by improving receivers
   /
4389
diffusion coefficients from the rate of decay of meteor trails  an
estimate of the diffusion coefficient in the meteor zone is obtained
by an extension of huxleys theory of ambipolar diffusion  the absolute
value of the diffusion coefficient thus calculated and its gradient
with height are confirmed by comparison with results of measurements
made at adelaide using radar technique at a wavelength of  the theory
appears adequate to account for the observed variation or diffusion
coefficient with height
   /
4390
the identification of sunspots by means of chromospheric faculae
   /
4391
influence of temperature and humidity on the electrical constants
of the ground
   /
4392
comparison of records of the horizontal component of the terrestrial
magnetic field at kerguelen and at heard island  the records confirm
that magnetic activity is particularly strong during the equinoxes
the correlation coefficient for the two stations is about  ionograms
obtained during the strong magnetic variations are characteristic
of a highly disturbed ionosphere
   /
4393
nol vector airborne magnetometer type  the instrument previously
described has been modified so as to be suitable for use in all latitudes
and to simplify the reduction of results
   /
4394
a recording magnetic variometer  description of an electronic magnetometer
designed for continuous measurement of changes in the earths magnetic
field at one place variations as small as oersted can be recorded
   /
4395
notes on the distribution of in high latitudes  an examination of
experimental data shows that the equivalent overhead currents for
the preliminary reverse impulse in this type of magnetic storm in
the northern hemisphere are represented by current flows across the
polar cap from the longitude corresponding to that corresponding
to and by the resulting two vortices extending to lower latitudes
a clockwise vortex in the afternoon hemisphere and a weaker counter
clockwise vortex in the forenoon hemisphere
   /
4396
the effect on geomagnetism of the solar eclipse of  an examination
of records of magnetic declination from observatories near the path of
totalit y shows that a maximum magnetic effect occurs at the time
of totality appearing as a diminution of normal daytime departures
from the night time value of the declination  quantitative agreement
with theory is shown
   /
4397
survey of airborne microwave refractometer measurements  results
of measurements made at various places in the over land and off the
east and west coasts are summarized  variations of the vertical distribution
of refractive index are studied in relation to time and place
particular attention is paid to the fine detail of the refractive
index structure  see also of
   /
4398
amplitude scale and spectrum of refractive index inhomogeneities
in the first meters of the atmosphere  report of an extensive series
of observations made using two refractometers at various levels on
a tower  the correlation between the refractive index variations
and variations of meteorological conditions is studied
   /
4399
seasonal and latitudinal temperature changes in the ozonsphere  computations
are presented relevant to the elucidation of the temperature
structure in the middle atmosphere
   /
4400
hydromagnetic resonance in ionospheric waves  the large scale travelling
ionospheric disturbances detected by various workers in the layer
may be partially explained as an electron resonance effect produced
when an initial atmospheric disturbance generates natural modes of
electromagnetic oscillation as a result of hydromagnetic coupling
   /
4401
some features of the layer observed at the ionosphere field station
haringhata calcutta  photographic records are reproduced showing
how the ionization originates at layer level moves downwards and
forms a sporadic layer
   /
4402
recombination and ion production from the total electron content
revised values are given for the figures suggested previously for
the mean recombination coefficient and the mean rate of ion production
in the layer  results of observations at ibadan for magnetically
quiet and disturbed days are plotted and discussed
   /
4403
a consideration of the mechanism of electron removal in the layer
of the ionosphere  possible mechanisms of electron removal are discussed
in the light of observations  no satisfactory theory of the phenomenon
exists
   /
4404
variation of during solar eclipses  records obtained by minnis at
khartoum in and by stoffregen in the north of sweden in are discussed
and compared with observations from various stations in a decrease
of during the eclipse is found only at places where the eclipse is
total or nearly so  the typical eclipse configuration of sun moon
earth is thought to be in some way responsible for the associated
preliminary increase of
   /
4405
the lunar semidiurnal oscillation in the ionospheric absorption of
radio waves  vertical incidence absorption measurements made at pennsylvania
state university during appear to confirm earlier work by
   /
4406
geomagnetic activity and average deviations of daytime layer critical
frequencies in different geomagnetic latitudes  analysis of data
from six ionospheric sounding stations and one geomagnetic observatory
shows a distinct dependence of the average daytime deviations from
median valves on the geomagnetic latitude the seasons and the sunspot
cycle  the effect on the prediction of ionospheric disturbances is
discussed and the reliability of predictions is assessed
   /
4407
sporadic movements  reports of radio amateurs on reception in n america
are consistent with atmospheric movements at height of with speeds
averaging about  data on winds at heights up to determined by various
methods indicate that at all heights the winds are predominantly
from the east during summer and from the west during winter
   /
4408
the auroral layer ionization and auroral luminosity  an empirical
relation is established between the photon emission within the negative
nitrogen bands of aurorae in zenith and the maximum electron density
in the layer  the recombination coefficient in the layer during aurorae
is  in medium to strong aurorae the mean electron density deduced
from critical frequencies is between and electrons  echoes observed
during aurorae may be explained as back scatter from the ground reflected
at low incidence from the auroral layer
   /
4409
the effects of anisometric amplitude patterns in the measurement
of ionospheric drifts  measurement of ionospheric drift by determination
of time shifts between fading curves of ionospherically reflected
waves received at three spaced points is discussed and the errors
involved in assuming that the amplitude pattern on the ground is
statistically isometric ar evaluated  from recordings of fading curves
on a mean error of in the direction of drift was found the greatest
error being  the errors are not generally systematic
   /
4410
the shape of irregularities in the upper ionosphere  observations
of radio stellar scintillations made with three spaced receivers
on a frequency of show that irregularities in the amplitude pattern
on the ground are regarded statistically elliptically shaped the
ratio of major to minor axis being at least  the direction of the
major axis of the corresponding ellipsoidal ionospheric irregularities
appears to be along the lines of force of the earths magnetic field
estimates of the drift velocity of ionospheric irregularities based
on the assumption that the ionospheric pattern has spherical symmetry
are hence subject to error
   /
4411
some waveforms of atmospherics and their use in the location of thunderstorms
the main types of atmospherics waveforms recorded in southern
england are illustrated and their use in estimating range is discussed
in an analysis of recordings made during one year of the waveforms
recorded by day and of those by night were suitable for this purpose
most night time storms within a distance of produce some waveforms
from which range may be determined with an accuracy within by day
the corresponding distance is in summer and in winter
   /
4412
the pulse transfer function and its application to sampling servo
systems
   /
4413
the frequency response analysis of nonlinear systems
   /
4414
the stability and time response of fast operating closed loop pulsed
radar circuits  the paper deals with the stability and time responses
of a sampling servo system typical of range measuring and overall
feedback circuits used in pulsed radar equipments in which the loop
response time is not many times greater than the pulse repetition
time  the case of a high speed radar controlled missile may be such
a system  conditions under which nyquist plots can be made are given
expressions for the output both at and between the sampling times
are obtained in terms of the input functions of the system  the operation
of the system in the presence of noise is considered in the appendix
a short list of transformations suitable for analysis is included
   /
4415
the temperature dependence of the capacity of the copper oxide rectifier
the variation of the capacitance at the metal semiconductor boundary
is calculated on the assumption that it is caused by the temperature
variation of the free charge carrier concentration in the semiconductor
the calculated results are compared with experimental results for
the temperature range from
   /
4416
properties of selenium rectifiers with various impurities  se rectifiers
were prepared with halogen and halogen compound impurities and their
characteristics were investigated  the effect of fluorine and fluorine
compounds on the conductivity was nil that of alkali halides small
and that of bromine pronounced  thallium bromide copper bromide tellurium
and arsenic have a deleterious effect on the rectifier properties
results also show that useful rectifiers can be made using very pure
se
   /
4417
semiconducting ignitors for ignitron rectifiers  a detailed report
on an experimental investigation is presented as a result of which
methods are proposed for the design and manufacture of ignitors based
on silicon carbide
   /
4418
on the design of rectifiers with electron stabilization  the design
of a stabilized rectifier should be divided into two stages calculation
of the limits of stability of the limiting values of the mains voltage
and load current for normal operation of the rectifier and determination
of the coefficient of stability  suitable methods for dealing with
stage are proposed  details of the calculation are set out and the
case of the regulating valve with a shunt is discussed separately
   /
4419
an attempt to simplify coding for the manchester electronic computer
two main simplifications are made both at the cost of increased machine
time  to ensure that all quantities involved in a calculation are
represented to the required degree of accuracy every number occurring
is associated with its own scale factor  again in using the two levels
of storage provided arrangements are made so that instructions are
written out as if for a one level store  a program in the simplified
form is described
   /
4420
a magslip isograph  the terms of a polynomial equation to be solved
are represented by alternating voltages of varying time phases obtained
from magslip transmitters  the instrument described is capable of
solving sixth degree equations having real coefficients and may be
used for the e valuation of polynomials
   /
4421
a flutter computer with low gain amplifiers  low gain amplifiers
are used thus avoiding drift troubles  the principle of the computer
is to shift all the poles of the solution to the left in the complex
plane being a stable solution of the problem  the method is useful
in low stiffness problems
   /
4422
basic chassis for experimental work  design details are given for
a universal unit for use in computers for manufacture in small quantities
   /
4423
an approximate method for obtaining transient response from frequency
response  a rapid method for finding the transient response of a
linear system whose frequency response is known numerically but not
as an analytical function involves use of a specially constructed
transparent cursor  the technique can also be used to deal with the
inverse problem or to derive a analytical function representing the
behaviour of a system of which either the frequency response or the
transient response has been measured
   /
4424
transformer design on insertion loss principles  wide band transformer
data can be calculated using the normalized values for the circuit
elements of high pass and low pass networks derived from insertion
loss theory for reactive quadripoles examples of which are tabulated
by considering the transformer equivalent circuit as part of a tchebycheff
filter network of higher order significant improvements can be
made in the transmission characteristic  by introducing special low
permittivity layers between windings further improvement is possible
   /
4425
perpendicularly superposed magnetic fields  digest of a paper to
be published in  theory is outlined for a cross field reactor comprising
a hollow ferrite toroid carrying one annular winding internally and
one toroidal winding externally  the device can be used as an low
level converter or modulator as a variable inductance or as a frequency
multiplier of divider
   /
4426
analysis of optimum shape for magnetic amplifiers  digest of paper
to be published in
   /
4427
composite multistable circuit with natural quinary cycle  a circuit
composed of binary and ternary stages is used based on design principles
described previously  details are given of a decade unit embodying
the circuit
   /
4428
nbs buaer preferred circuits program  report of investigations made
by the n b s in conjunction with the u s navy bureau of aeronautics
of the feasibility of standardizing the circuits used in electronic
equipment  a similar account is also given in
   /
4429
topological and dynamical invariant theory of an electrical network
   /
4430
linear transmission of pulses at centimetre wavelengths  analysis
for the transmission of pulses of arbitrary shape by waveguide and
cavity resonator systems is based on use of laplace transforms  using
theory presented previously a calculation is made of the transfer
function for a system of weakly coupled cavity resonators
   /
4431
the maser new type of microwave amplifier frequency standard and
spectrometer
   /
4432
influence of the order of overtone on the temperature coefficient
of frequency of at type quartz resonators
   /
4433
magnetic fields in small ferrite bodies with applications to microwave
cavities containing such bodies  an analysis is presented of the
field inside small spheres and cylinders of ferrite excited by circularly
of linearly polarized magnetic fields in cavities  the formulae
derived are used to calculate the detuning and change of value of
the cavity on introducing the ferrite body or conversely to determine
the ferrite permeability tensor from the observed changes in the
cavity characteristics
   /
4434
increasing the factor of the cavity resonator by regeneration  a brief
note on the cavity resonator used in conjunction with the molecular
beam oscillator  a factor of has been obtained for periods of up
to
   /
4435
the graphical determination of the geometrical parameters of loss
free linear quadripoles  the methods described previously are applied
to determine the iterative impedance and iterative transfer constants
   /
4436
application of the wiedemann effect to the magnetostrictive coupling
of crossed coils  an electromechanical quadripole is described comprising
a tubular magnetostrictive ferrite core carrying crossed coils
one wound toroidally and the other as an external helix  theory is
presented in terms of an equivalent circuit  the device can be used
for filtering gating phase reversing etc  successful experiments
with ferroxcube cores operating at frequencies between are reported
   /
4437
catalogue of power law and tchebycheff type filter up to order  four
table give the circuit diagrams and the normalized values of the
circuit elements in maximally flat response and tchebycheff type
filters terminated and with a short or open circuit at one end for
different values of the pass band reflection coefficient  corresponding
attenuation characteristics are given in diagrams  the application
of the tables is illustrated in five numerical examples
   /
4438
electrically controlled audio filters  design theory based on the
work linvill is presented for a low pass and a high pass filter both
having cut off frequencies continuously variable between  the cut
off characteristic may be controlled by the signal for investigating
the structure of speech signals  experimental results are reported
   /
4439
nd receivers to be operated with a single aerial in the frequency
range  a coaxial line construction with tuned cavity resonator is
used  a four coupler system with separation of between channels can
provide adjacent channel reduction of with insertion loss of
   /
4440
equivalent equalizer networks  the various types of frequency response
curves obtainable with practical networks of the derivative equalizer
type are analysed and the equivalent constant resistance networks
are determined
   /
4441
improvement of stabilized pound oscillator  adjustments of the oscillator
is facilitated by means of a sawtooth generator with switching
arrangements such that it can be interpolated at carious points in
the circuit the attainment of the desired oscillator characteristic
being indicated on a c r o
   /
4442
junction transistor blocking oscillators  circuits have been designed
producing pulses with rise time using transistors with cut off frequencies
of a few  details of the regenerative transformer coupling are
discussed  triggering requirements and the effects of loading are
evaluated  experimental results support the theory
   /
4443
stabilization of pulse duration in monostable multivibrators  pulse
duration stabilization of triggered circuits by feedback is described
practical circuits suitable for frequency division and pulse generation
in television equipment are illustrated
   /
4444
transistor pulse generators  numerical design data are given for
four circuits using ge junction transistors and one using a si transistor
pulse rise times as low as are attainable at repetition frequencies
up to pulse durations are variable from
   /
4445
saturable reactor frequency divider  a saturable reactor is used
in conjunction with a rc network to provide a circuit capable of
producing a pulse output at the frequency or a submultiple of the
frequency of a sinusoidal input  a circuit providing synchronizing
pulses for a radar modulator at half the frequency of the power supply
is described
   /
4446
automatic drift compensation in d c amplifiers  the circuit discussed
is similar to that described by offner  it may be used in systems
where periodic interruption of the input and noncontinuous compensation
are permissible as in analogue computers sampling amplifers etc
   /
4447
optimum tube utilization in cascaded distributed amplifiers  analysis
is presented taking account of the bandwidth narrowing factor introduced
by cascading stages this factor is evaluated for an amplifier using
constant r bridged t lines  a numerical example is discussed
   /
4448
rejection factor of difference amplifiers  analysis shows that the
rejection factor of a differential amplifier can be made arbitrarily
large without necessitating pre selection of valves or exact equality
of the two halves of the circuit  the theory is supported by experimental
results  the parameter termed rejection factor is the same as
that termed transmission factor by parnum
   /
4449
magnetic amplifiers as control components  the advantages and limitations
of magnetic amplifiers for voltage and current control switching
and amplifying are compared with those of various other devices important
properties are tabulated
   /
4450
a germanium diffused junction photoelectric cell
   /
4451
low level magnetic amplifier  a two stage push pull amplifier is
described in which a high degree of negative feedbacks is used obtain
stability and linearity with high input impedance  by careful balancing
of components the zero drift measured in terms of input power is
reduced to the order of
   /
4452
transistor power amplifiers  discussion of conditions for junction
transistors handling sinusoidal signals indicates that the maximum
possible output is not necessarily limited by the maximum allowable
collector dissipation limitations set by the cariation of current
gain with emitter current become particularly significant in class
b amplifiers because of their very high efficiencies  push pull class
b operation is preferred to class a of the three possible basic connections
the common collector arrangement is preferred as providing the
best compromise between gain and distortion and permitting the simplest
design of output transformer  no great advantage is found by using
complementary and transistors  applications involving nonsinusoidal
signals are discussed briefly
   /
4453
predictable design of transistor amplifiers  the transfer characteristic
of a multistage low frequency amplifier using junction transistors
may be made independent of the transistor characteristics by the
use of degenerative current feedback at the same time improving linearity
the importance of stable biasing arrangements is emphasized
   /
4454
simplified design procedures for tuned transistor amplifiers
   /
4455
maximum power transfer in transistor amplifiers  the theoretical
treatment of transistor amplifier performance is simplified by restricting
consideration to the condition of maximum power transfer when
it is possible to make a rapid assessment of the available power
gain for a particular configuration in terms of the transistor parameters
curves show the relation between maximum power gain current gain
and transistor constants for grounded base and grounded collector
arrangements
   /
4456
properties of pore conductors
   /
4457
some considerations regarding the principle of phase invariance
it is shown that the conservation laws characterizing the ether can
be derived from the principle of phase invariance provided a complex
field is used to describe the ether
   /
4458
tamm equations of state of electrons at the surface of a crystal
and surface oscillations of lattice atoms  a review  about half of
the references are to russian work
   /
4459
photo effect in metals  a critical survey with particular reference
to the theoretical development of the subject
   /
4460
electroluminescence excited by short field pulses  an extension of
a previous investigation is reported pulses of duration were used
the luminescence decay rate is highest for the shortest pulses  results
are consistent with previous conclusions regarding polarization effects
a threshold pulse duration of about is estimated to be necessary
for the accumulation of polarization charges
   /
4461
dependence of light amplification in phosphors on light intensity
differential chromaticity thresholds in the direction of primary
blue in a trichromatic synthesis system
   /
4462
dielectric properties of ice at very low frequencies and the influence
of a polarizing field  measurements at frequencies down to are reported
the loss factor passes through a low frequency maximum which is distinguishable
from that associated with the dipole dispersion by its different
temperature dependence  the effect of impurities is to shift the
maximum towards higher frequencies  application of a unidirectional
field does not affect the permittivity of the pure crystals but eliminates
the low frequency dispersion when impurities are present  the
observations are consistent with macdonalds theory
   /
4463
the dielectric constant of an imperfect nonpolar gas
   /
4464
electron phonon interaction in metals  the role of electron electron
interactions in determining th electron phonon interaction in metals
is investigated by extending the bohm pines collective description
to take into account the ionic motion
   /
4465
single band motion of conduction electrons in a uniform magnetic
field
   /
4466
the general motion of conduction electrons in a uniform magnetic
field with application to the diamagnetism of metals
   /
4467
theory of the electrical conductivity of a plasma  the calculation
presented is based on integration of the boltzmann equation in which
the atoms ions and electrons are not treated as rigid perfectly elastic
spherical scattering centres
   /
4468
the importance and the origin of modes of description of magnetogalvanic
effects
   /
4469
statistical description of assemblies with collective interaction
part  the various formulations of the carrier kinetics  the range
of validity of approximations made in analyses by other workers is
discussed
   /
4470
pulse controlled cathode sputtering and electron emission
   /
4471
electron liberation by low energy ions at metal surfaces and in gases
two experimental methods of investigation are described the disturbing
influence of photo ionization was completely eliminated  results
indicate that in certain cases ionization in the gas by collision
f ions may be important
   /
4472
mechanism of uniform field breakdown in hydrogen
   /
4473
growth of current between parallel plates  analysis for the initial
stages of a discharge involving secondary electron emission is presented
in an alternative form to that given previously
   /
4474
reduction of the cathode fall of a normal glow discharge by illumination
of the cathode  experimental results indicate that the relation between
the normal cathode fall the cathode work function and the current
density due to illumination is given by where is constant whose magnitude
depends on the ionization potential of the gas and i another constant
a special based cathode with and adsorbed layers was used
   /
4475
measurement of electric fields as applied to glow discharges  a magnetically
compensated zero deflection electron beam method is described
using automatic recording field strengths between and can be rapidly
measured and tube wall potentials can simultaneously be recorded
   /
4476
electron emission from cathode surfaces after glow discharges  brief
account of experiments made to elucidate exo electron emission phenomena
   /
4477
emission experimental measurement of the average electron current
density from tungsten  the results of the experiments reported support
the theory presented previously
   /
4478
quantum effects in the interaction between free electrons and electromagnetic
fields  a discussion of the possibility of arranging experiments
so that the spread of an electron beam in a transverse field due
to the quantum dispersion of the energy exchange can be distinguished
from that due to practical experimental factors
   /
4479
two problems in geometrical optics and application of the results
in electron trajectory calculations
   /
4480
a semi empirical expression for the first townsend coefficient of
molecular gases  the formula derived by druyvesteyn and penning is
discussed and is modified on the basis of different assumptions regarding
the energy dependence of the scattering cross sections of the
gas molecules
   /
4481
atomic negative ion photodetachment cross section and affinity measurements
the spectral distributions of the and cross sections for photodetachment
have been measured  the measurements are consistent with
the theory of chandrasekhar  a curve has been fitted to the results
for  the threshold of this cross section the affinity of is found
to be electron volts  no evidence is found for resonance at the threshold
or for the existence of excited ions  the apparatus is described
in detail
   /
4482
dipolar ferromagnetism at
   /
4483
asymptotic expansions of solutions of  the equation investigated
is important in the theories of wave propagation  a direct method
is developed for obtaining more general asymptotic expansions than
those given previously
   /
4484
strict theory of the diffraction of electromagnetic waves by plane
screens  analysis is based on the hertz or fitzgerald vector which
can be represented by a double fourier integral the fourier amplitudes
giving the angular distribution of the far field are derived from
a system of simultaneous integral equations which can be solved approximately
by developing in certain orthogonal systems  an alternative
method of solutions is an iteration process based on the kirchhoff
approximation  the relation with huyghens principle and with the
variation problem of diffraction theory is established
   /
4485
diffraction of microwaves by long metal cylinders  report of an experimental
investigation at about using parallel plate equipment based
on that described by and cylindrical obstacles of transverse dimensions
comparable with  calculated and experimental results for circular
cylinders are in good agreement and are used as a basis for studying
diffraction by square and rectangular cylinders  the method gives
reliable information about scattering from obstacles of forms such
that no exact theoretical solutions are available
   /
4486
on the scattering cross section of an obstacle  the relation between
th scattering cross section and the scattered amplitude for an obstacle
in an incident plane wave previously discussed by is here established
by a calculation of the energy flow  when the incident wave emanates
from a point source the sum of the scattering and absorption cross
sections is determined by the value of a certain field in the neighbourhood
of the source  the discussion is presented in terms of an wave
but is adaptable to sound waves or atomic collisions
   /
4487
possible methods of obtaining active molecules for the molecular
generator  the use is suggested of an auxiliary field to produce
resonance transitions between the energy levels in the molecules
such as to increase the fraction of active molecules in the beam
   /
4488
the maser new type of microwave amplifier frequency standard and
spectrometer  experimental results with the device described previously
are compared with predictions from theory  particular attention is
given to operation with ammonia molecules  an amplifier noise figure
of unity should be attainable under certain conditions
   /
4489
influence of an inhomogeneity of the high frequency field in nuclear
magnetic resonance  theoretical results show that to a first order
approximation the inhomogeneity has no effect on the signal amplitude
provided that the conditions for a maximal signal in a homogeneous
field are fulfilled
   /
4490
radio stars and their cosmological significance  a survey presented
as the lecture
   /
4491
location on jupiter of a source of radio noise  earliest records
of radiations and of visually observed activity on jupiter are discussed
in relation to the observation of a source by this source is probably
identifiable with the visibly disturbed region observed by fox
   /
4492
on the great importance of th r f radiation from the planet jupiter
continuation of the previous discussion of the observations reported
by  the cyclic variation of relative position of points on jupiter
and on the earth is examined  based on considerations of temperature
and composition the hypothesis is advanced that the observed radiation
is produced by continuous eruption of solid electrified blocks of
iron with linear dimensions of the order of such eruptions could
be expected in the vicinity of the large red spot on jupiter  the
relevance of the hypothesis to astronautical problems is briefly
indicated
   /
4493
monochromatic radiation of deuterium at a wavelength of from the
centre of the galaxy  a brief report is presented of observations
indicating the presence of deuterium in the interstellar space the
concentration is about that of the non ionized hydrogen  a block
diagram is given of the equipment used in conjunction with a dipole
aerial at the focus of a diameter parabolic reflector
   /
4494
note on the electrophysical determination of the velocities of meteors
the question is briefly discussed whether the trail is electrically
reflecting immediately after passage of the meteor or only after
the ionized cylinder has expanded to a certain diameter  the answer
is decisive for the theory of the origin of the interplanetary material
   /
4495
the giacobinid meteor stream  an account is given of the systematic
radio echo observations in the years the unexpected return of the
meteor shower during the daytime in and the significance of its absence
in are discussed
   /
4496
influence of the age of centres on their radiation at centimetre
wavelengths  continuation of investigation reported previously  th
flux from an active centre appears to vary directly as its sunspot
area for the first days of its life after which it decreases more
slowly than the sunspot area  the corresponding aging function is
shown graphically
   /
4497
brightening of the solar limb in the far ultra violet  locations
and relative intensities of sources controlling the and layers as
provisionally determined from measurements of electron density made
at slough and inverness during the solar eclipse of indicate brightening
of the solar limb near the equator and darkening of the limb at the
poles  the intensity distribution over the solar disk is similar
to that found by christiansen and warburton for radiation on
   /
4498
electromagnetic induction in a two layer earth  the theory developed
by is extended to determine the induced field on the surface of a
medium whose conductivity is a function of depth  the results are
applied to evaluate the field induced when an oscillating magnetic
dipole is placed on the surface of a flat two layer earth
   /
4499
a measurement of the earths magnetic field by nuclear induction
th free precession technique outlined by is used
   /
4500
daytime enhancement of size of sudden commencements and initial phase
of magnetic storms at huancayo  statistical analysis of data for
the period shows that the frequency of occurrence of is independent
of the time of day but that the average size of and of initial phases
of magnetic storms is greater during daylight hours  the size is
also found to vary directly with the amplitude of the diurnal variation
of  both phenomena may be due to electrojets in polars latitudes
caused by the sun
   /
4501
magnetic effects during solar eclipses  records taken in south africa
at the time of the annular eclipse of the sun on show a decrease
in intensity of the geomagnetic field horizontal component in accordance
with theory but also an increase in the vertical component
   /
4502
observation of an ozone hole over the alps  observations are reported
which throw light on the relations between vertical air streams in
the stratosphere and the vertical distribution of ozone
   /
4503
movements of irregularities in the region  summer night observations
of fading patterns of transmissions from three broadcasting stations
spaced about apart at the vertices of a triangle are consistent with
large scale movements in the region from east to west with velocities
of  rapid fading with a duration of a few hours is considered to
be due to scattering by clouds showing turbulent velocities of
   /
4504
world wide daily variations in the height of the maximum electron
density of the ionospheric layer  a formula relating is applied to
determine world wide latitudinal variations of the results so obtained
being in good agreement with results published by local observatories
in middle and higher latitudes rises in summer daytime and falls
in winter daytime  near the equator there is a daytime rise throughout
the year
   /
4505
a discussion on the variation of region height  further evidence
is adduced in support of the authors suggestions regarding the distribution
of ionization in the region
   /
4506
contribution to the study of the effect of geomagnetism on the layer
results of an analysis of observations for and confirm the dip in
the value of at the magnetic equator reported by  there is also a
minimum in the values of the factor and the at the magnetic equator
   /
4507
radio star scintillations and ionosphere  the observed intensity
at the surface of the earth of radiation at a frequency of from a
radio star has been studied  a relationship is shown to exist between
the fluctuations of scintillations in this observed radiation intensity
and the angle of its incidence on the level of the earths ionosphere
the occurrence of these scintillations is compared with other ionospheric
phenomena as determined by vertical soundings from the earth
the probable cause of the fluctuations has been localized to a source
in the high ionospheric regions
   /
4508
effect of radiation from solar flares on the ionosphere and the earths
magnetic field  variation in the earths magnetic field and the corresponding
variations in the ionic density of the layer due to solar flares
are recorded  the value of the intensity of ultraviolet radiation
before it enters the atmosphere is obtained  the constant relating
the ionic density and the accompanying magnetic variation is also
estimated
   /
4509
geomagnetic distortion of the region on the magnetic equator
   /
4510
researches on the geomagnetic distortion in the ionosphere  observed
facts of the geomagnetic distortion in the ionosphere  theoretical
study on the geomagnetic distortion in the layer  characteristics
of the layer on the magnetic equator  effect of gravity and ionization
pressure gradient on the vertical drift in the region  world wide
observations made during the sunspot minimum period and during the
second polar year are analysed and discussed theoretically  the anomalous
distribution in the region above the magnetic equator may be explained
by vertical electron drifts caused by the electric field  an ionospheric
model consistent with the results of rocket experiments is used
the particle density at altitude must be of the order of
   /
4511
studies on the disturbances in layer associated with geomagnetic
disturbances  earlier work is summarized and discussed
   /
4512
day sky brightness to  measurements made with rocket borne stereocameras
suggest that the brightness is due entirely to rayleigh scattering
by air molecules  there is no evidence of high altitude clouds
   /
4513
double doppler radar investigations of aurora  the power spectra
of auroral echoes of signals on are compared with observations of
the visible aurorae and with simultaneous echoes of signals on and
using standard high resolution radar equipment  a number of auroral
models are considered in a discussion of the results
   /
4514
auroral echoes observed north of the auroral zone on  at a site north
of the accepted auroral zone maximum radar echoes on a frequency
of were readily obtained from the north but practically none from
the south the range of the reflecting points was from to  these results
are in agreement with the theory of reflection by aurorae suggested
by and developed by requiring near perpendicularity of radio ray
paths to the lines of the earths magnetic field  on transmitting
towards the south across visible aurorae on propagation associated
with aurora was almost nonexistent as required by the theory
   /
4515
measurement of the arrival angle of whistlers  it is suggested that
storeys theory on the origin of whistling atmospherics could be tested
by determining their arrival angle by a phase measurement method
based on that of using a pair of aerials spaced apart along the direction
of the horizontal component of the geomagnetic field
   /
4516
standards on graphical and letter symbols for feedback control systems
   /
4517
low ripple adjustable regulated power supply  a unit giving and output
of with an output impedance described
   /
4518
transistor converters  a transistor in a relaxation oscillator is
arranged to interrupt a circuit energy is stored in the transformer
inductance during the on period and is delivered to the output circuit
at an increased voltage during the off period the circuit thus acting
as a step up device  design and operation of practical arrangements
are discussed  a shorter account of the work is given in wireless
world
   /
4519
germanium power rectifiers
   /
4520
improving the performance of the series electronic voltage regulator
compensating networks for improving the performance of the conventional
series electronic voltage regulator circuit are analysed  the theory
is compared with measurements made on a fully compensated circuit
   /
4521
effects of heater voltage variations of valves in certain stabilizer
circuits  calculations further to those presented previously show
that in series parallel stabilizer circuits having a resistor in
the cathode lead of the amplifier the effect of heater voltage variations
is not serious because the two valves produce output voltage changes
of opposite sign
   /
4522
electronic computing machines and their uses  basic design of digital
computers is described  programming for suitable types of problem
is discussed and illustrated by examples
   /
4523
an simple electronic fourier synthesizer  an experimental model of
a machine for two dimensional fourier synthesis is described which
incorporates magnetic drum storage of the required sine and cosine
functions
   /
4524
simplified analog computers  differential analyser is described based
on ten identical operational amplifiers which may b used for integration
multiplication etc as required by the particular problem  the arrangement
is very flexible and may be used with external circuitry for the
generation of special functions required in synthesizing particular
input analogues
   /
4525
some aspects of the design of a d c amplifier for use with a slow
analogue computer  the errors introduced as a result of an h t resistance
common to several amplifiers is calculated and a criterion for
the accuracy of a linear computer stated
   /
4526
transistor amplifiers for use in a digital computer
   /
4527
contribution on the calculation of the total impedance of parallel
connected impedances  a method of calculation involving use of a
special transparent rule and a simple nomogram is described and illustrated
by a numerical example
   /
4528
stability criteria for an electrical or mechanical system with distributed
parameters  for electrical or mechanical systems with distributed
parameters or with an element producing a finite time delay to be
stable all the roots of the appropriate characteristic equation must
be negative or have negative real parts  if these equation is expressed
in the form then for positive must be positive and must be greater
than a certain critical value which is a functions of  the example
is given of the application of these criteria to a servomechanism
   /
4529
a tapered strip line for pulse transformer service  a rolled up construction
is described for an exponential line impedance transformer
the impedance is at one end of the line and at the other pulse as
long as can be handled
   /
4530
the turnover phenomenon in thermistors and in point contacts germanium
rectifiers  the turnover power in thermistors increases as the square
of the absolute ambient temperature  the similarity i form between
the reverse characteristic of a teristic of a thermistor a thermal
hypothesis for rectifier turnover but in the latter case the turnover
power decreases approximately linearly with ambient temperature
the type of function necessary to reproduce the rectifier characteristics
at turnover is discussed such a function cannot be derived from
existing theories of rectification
   /
4531
a survey of the application of ferrites to inductor design
   /
4532
influence of ratio on magnetic properties of toroidal cores  the
optimum design of cores for magnetic amplifiers is discussed  a theoretical
result is obtained assuming a parallelogram shaped hysteresis
loop and an experimental investigation is reported  the dependence
of the optimum tatio on the magnetic properties of the core material
is indicated
   /
4533
electrically variable gas dielectric capacitor  a neon tube placed
between the plates of an air dielectric capacitor give a variation
in dielectric constant proportional to the tube current  maximum
variation of capacitance is about  the device may be used for frequency
control of self excited oscillators
   /
4534
a simplified method of solving linear and nonlinear systems  the
method described uses the transform directly to determine the responses
of linear and nonlinear systems approximately  the solutions are
given as time series representing the values of the response at equally
spaced instants  both constant and time varying systems are considered
   /
4535
the harmodotron a beam harmonic higher order mode device for producing
millimeter and submillimeter waves  high power oscillations are generated
by exciting a single higher order mode in a cylindrical cavity
by means of a bunched beam of electrons
   /
4536
simultaneous approximation for the amplitude and delays time of an
ideal low pass filter using the flow analogy  analogies between transmission
phenomena in networks and current flow in a potential fields
are discussed  a distortion free low pass filter can be represented
by two superposed fields one with parallel flows corresponding to
the distortion free aspect and the other with radial flow corresponding
to the filter aspect  such a representation involves a finite residual
error which cannot be eliminated without introducing instability
but which can be reduced indefinitely by increasing the delay time
   /
4537
electromechanical filters for carrier and sideband selection  torsional
type filters comprises cylindrical resonators with coupling necks
are discussed  descriptions are given of two filters with bandwidths
of respectively  using a particular alloy known as the temperature
variation of frequency is parts per millions  magnetostrictive transducers
made of this alloy or of ferrite are used  spurious modes of
vibration are reduced by a balanced arrangement of the transducers
and by mechanical damping in the end supports
   /
4538
a push button attenuator for frequencies up to  details are given
of resistance attenuator providing attenuation up to steps with an
interpolation step of  each section comprises a network with the
shunt arm bridged by capacitance to compensate the inductance of
the series arms
   /
4539
cherenkov radiation  a brief explanation is given of the mechanism
of cerenkov radiation which may find application in oscillators
   /
4540
cathode follower phase shift oscillator  analysis indicates that
better frequency stability is obtained by connecting the phase shifting
network between grid and cathode than by connecting it in the anode
circuit  calculations are made for three typical circuits
   /
4541
investigations of the characteristics of bi stable multivibrators
the characteristics are discussed theoretically with reference to
the design of reliable counting and switching units  design procedure
is illustrated by two numerical examples one of a binary counting
unit with counting rate up to at supply voltages between the other
for a pulse counting rate at supply voltages between and  a modification
of the latter circuit using a double triode instead of was used at
counting rates up to
   /
4542
the diode pump integrator  the designs of a diode circuit for integrating
a train of pulses is discussed and conditions are established
for linear and nonlinear operation  an application to a frequency
sensitive relays with quick on off characteristics is described
   /
4543
a logarithmic voltage quantizer  details are give of an analogue
to digital converter which provides an output pulse whose duration
is proportional to the logarithm of the input voltage the output
pulse duration being determined by counting the number of fixed frequency
pulses occurring in the same interval  range of input voltage
is with a threshold input pulse length of
   /
4544
analog to digital data converter  the required conversion is performed
by arranging an oscillator generating pulses at a repetition rate
proportional to the analogue voltage to feed a digital counters for
a fixed period  the oscillator described has a range of four decades
stability is better than of maximum pulse frequency
   /
4545
the compensation of wide band amplifiers at high frequencies  analysis
is given for various coupling arrangements including and special
two and four terminal networks
   /
4546
distortion in feedback amplifiers  analysis is presented for frequency
dependent feedbacks  consideration is re stricted to cases where
the distortion products are comparatively small and the nonlinear
elements can be described by a power series with only a few terms
formulae are derived for a number of third order products
   /
4547
analysis of the common base transistor circuit  mathematical errors
in a are pointed out
   /
4548
transistor circuit for resonance coefficient multiplier  use of transistors
in multiplier circuits is discussed  the input admittance is
calculated and the conditions for stabilization against self oscillations
are derived  design and performance of experimental arrangements
are described composite transistors may be used
   /
4549
transistor amplifiers for use in a digital computer  pulse regenerative
amplifiers for a synchronous binary computer are based on use of
external feedback so that a negative resistance transistor characteristic
is not required  by using semi gated feedback allowance can be
made for the slow recovery of ge diodes incorporated in the circuit
   /
4550
schaltungstheorie und messtechnik des dezimeter und zentimeter wellengeb
theory and applications of four six and eight pole networks are covered
circle diagram representation is used to show transformation properties
of four pole networks
   /
4551
the refractive indices of water vapour air oxygen nitrogen and argon
at experiments indicate that the refractive indices of water vapour
air anden are modified at microwave frequencies in the manner to
be expected from dipole theory the values for nitrogen and argon
should not vary with frequency and this is confirmed
   /
4552
the dielectric theory of electronic interactions in solids  the long
range part of the coulomb interaction of the electrons in solids
is treated by regarding the solid as a homogeneous dielectric  sustained
oscillations are shown to be possible in metals and are identified
with the plasma oscillations discussed by bohm and pines
   /
4553
the capacity and field of a cylindrical trough with a plane conductor
in the axial plane of symmetry
   /
4554
poissons partial difference equation  the greens functions and their
asymptotic behaviour for poissons partial difference equation in
two and three dimensions are discussed and the distribution of potential
and current in a regular grid of wires is calculated  the method
may also be applied to non isotropic grids and can be extended to
triangular and hexagonal grids in two dimensions and probably to
more complicated patterns in three dimensions
   /
4555
theory of electrical conductivity in metal  the fluctuations in the
potential in the electron ion plasma of a metal and the electrical
resistance due to the scattering of electrons by these fluctuations
are calculated
   /
4556
number of states and the magnetic properties of an electron gas
a theoretical investigation of the thermodynamic properties of conduction
electrons in metals
   /
4557
the infrared faraday effect due to free carriers in a semiconductor
   /
4558
growth of pre breakdown ionization currents in hydrogen  experiments
are briefly reported the results of which indicate that the mechanism
of primary ionization is the same over a range of pressures from
a few
   /
4559
theory of langmuir probes  a note contrasting results of langmuirs
theory with those of the authors precise theory of the spherical
probe at low pressures and negative probe potential  electric microdischarges
in a dynamic vacuum  account of an experimental a theoretical
investigation of undesired discharges occurring as a result of surface
imperfections in vacuum apparatus operated at high voltage  experimental
electrode systems similar to those in electron microscopes were used
the phenomena are distinguishable from field emission and involve
repeated secondary emission of electrons and h ions  for voltages
applied in very short pulses the upper limit before onset of microdischarges
is higher than for continuous voltages
   /
4560
some factors influencing field emission and the fowler nordheim law
departures from the normal fowler nordheim law which have been observed
at fields up to have previously been ascribed to space charge field
distortion  it is shown that certain other effects due to failure
of the image law non uniformity of work function and to passible
surface irregularities could produce simular effects
   /
4561
electron emission from metal surfaces after mechanical working  a
fuller account of work described previously electron multiplication
by secondary emission was used to facilitate the the observations
   /
4562
a study of the structure of abraded metal surfaces  a report is presented
of an experimental investigation of the spontaneous and photoelectric
electron emission from abraded surfaces in various atmospheres  all
the metals investigated responded to radiation in the near ultraviolet
which form excess metal oxides responded to wavelengths in the visible
range also  from the observed rate of decay of emission it is inferred
that both thermal and oxidation phenomena are involved  previous
theories that the emission depends on exothermal processes are considered
untenable
   /
4563
theory of thermal conductivity of a plasma  the treatment is similar
to that used previously for investigating the electrical conductivity
of plasma
   /
4564
particle transport electric current and pressurehe problem discussed
by tonks is treated without detailed analysis of particle trajectories
qualitatively similar results are obtained
   /
4565
a note on the paramagnetic relaxation  the theory given explains
experimental results obtained by gorter for the dependence of the
spin spin relaxation time on the static field strength
   /
4566
electromagnetic theory of moving matter
   /
4567
magnetic field due to circular current  analysis is simplified by
applying recent work on elliptic integrals
   /
4568
production of millimetre waves by a magnetic undulator  measurements
hav made on a device of a type described previously and using an
electron beam from a pulsed linear accelerator  with a meaam intensity
of the output power was about intermediate between the values corresponding
to complete incoherence and complete coherence of the elementary
vibrations  the spectrum extended from with a maximum at
   /
4569
transmission of electromagnetic waves through inhomogeneous layers
layers are considered in which the dielectric constant is graded
from the value unity at each face to a maximum value at the mid plane
the variation being either linear or exponential  dielectrics are
prepared satisfying this specification by forming ordinary homogeneous
materials into a series of wedges or the like thus producing a space
periodic structure  reflection factor measurements made in free space
and in waveguides are reported  variation of reflection factor with
layer thickness is shown graphically for moltopren paraffin and trolitul
variation with angle of incidence is shown for trolitul  the experimental
results are compared with values of the reflection factor calculated
from solutions of maxwells equations for the appropriate conditions
such structures can give good transmission of microwaves over a wide
frequency band
   /
4570
generation of submillimeter waves  brief preliminary note describing
radiation observed unexpectedly when a bunched high energy beam of
electrons was passed through a simple rectangular waveguide
   /
4571
pulse techniques in microwave spectroscopy  methods are described
for exciting gases to states from which they emit coherent spontaneous
radiation in the microwave frequency region  the excitation is produced
by the application of short pulses of microwave power  the power
subsequently radiated by the gas is calculated for several cases
and experimental methods used to detect the radiation are described
the problem of sensitivity is discussed and compared to the sensitivity
obtainable i a continuous absorption experiment  the operation of
a high resolution microwave spectrometer which produces lines substantially
narrower than the usual doppler width is described  the method
used to stabilize the klystron used in these experiments which is
a modification of the pound method is given
   /
4572
spin echo serial storage memory  methods are discussed for storing
information in the form of pulses in a nuclear magnetic resonance
system by use of the free induction spin echo technique  th storage
capacity in liquids is expressed in terms of the thermal noise of
the detecting apparatus the self diffusion of the molecules and the
relaxation times  undesired echoes arising from the interaction of
input pulses are eliminated by and magnetic field modulation techniques
glycerin and solutions of paramagnetic ions in water provide storage
times of with a storage capacity of the order of echoes  larger capacities
expected from liquids with long relaxation times are not realized
owing to self diffusion
   /
4573
the hall effect in metals at high frequencies  theory is developed
in terms of a surface hall coefficient calculations are made for
a metal with two overlapping energy bands and the variations with
frequency and with field strength are shown graphically for some
special cases  at very low frequencies the hall coefficient is constant
over a range of higher frequencies it increases as the square root
of the frequency and then becomes constant again  the frequency variation
of the phase angle between current and hall is also investigated
   /
4574
quantum theory of magnetostriction  the theory of magnetostriction
in hexagonal single crystals is developed on the basis of a polar
model by considering the magnetic and magnetoelastic interaction
of electrons in the lattice  the energy spectrum of the crystal at
low temperatures the free energy and the temperature dependence of
magnetostriction constants are calculated
   /
4575
some consequences of the influence of elastic deformations on superconductivity
magnetostriction  analysis of conditions at the transition
from the normal conduction to the superconduction state in tin indicates
that magnetostriction mainly in the direction of the quaternary axis
is to be expected  conditions for are more complex
   /
4576
effect of defects on lattice vibrations  the theory of the effect
of localized defects such as impurities holes and interstitials on
the vibrations of crystal lattices is developed
   /
4577
international research in radio astronomy  special reports published
by the international scientific radio union and entitled respectively
discrete sources of extraterrestrial radio noise the distribution
of brightness on the solar disk and interstellar hydrogen are noticed
   /
4578
results of observations of discrete emitters of cosmic radio emission
on wavelength  results are given of a determination of the flux at
originating from the omega nebula orion nebula cassiopeia taurus
supernova and a source near the galactic centre sagittarius  when
these values are plotted together with observations at other radio
wavelengths and in the case of the crab nebula also at optical wavelengths
the results suggest that one mechanism may be responsible for
radiation both at optical and radio wavelengths
   /
4579
the day recurrence tendency of cosmic ray intensity  the day cycle
variations of cosmic ray intensity precede those of magnetic activity
by about five days it is tentatively suggested that the same solar
disturbances are associated with both phenomena
   /
4580
diurnal variations in the number of shower meteors detected by the
forward scattering of radio waves experiment  the theory developed
is applied to derive the expected diurnal variations of the meteor
signal rate for four showers as observed by means of a particular
forward scatter transmission path  these results are then compared
with the experimental signal rates  the good agreement obtained indicates
that the approximations inherent in the theory are sufficiently
accurate for practical purposes  the results also indicate that very
few meteors if any are observed under conditions which do not satisfy
the requirements for specular reflection
   /
4581
the decreasing phase of the last solar cycle as indicated by measurements
at the astronomical observatory at rome  detailed observations
are compared with those obtained at zurich
   /
4582
thermal upward flow in the ionosphere  the possibility of atmospheric
waves due to heating effects of solar radiation is established vertical
thermal flow in the region may give rise to ion drift along the magnetic
lines of force this may explain anomalous diurnal variations in the
layer  by applying the theory to observed ionospheric data for the
north american zone estimates are obtained for the velocity of the
ions and of the thermal flow
   /
4583
the detection of the current system in ionospheric radio sounding
anomalies found in the application of chapmans theory of ionosphere layer
formation of theory of ionosphere layer formation to layer phenomena
are explicable if it is accepted that the current system modifies
the diurnal variation of electron density in the layer most probably
by some form of vertical drift mechanism  similar phenomena are found
in the layer
   /
4584
the night time lower ionosphere as deduced from a theoretical and
experimental investigation of coupling phenomena at  experimental
work over the period is described and the results are compared with
theoretical results given by  curves show seasonal and diurnal variations
of the night time layer in the coupling region  region models
for the sunset period for are proposed the variation of electron
distribution during the night is deduced from a recombination coefficient
model suggested by  all available experimental data tend to confirm
the theoretical analysis
   /
4585
different stations  the possibility that the day to day changes in
absorption at slough swansea and freiburg are identical is examined
statistically  after allowing for known sources of error it is considered
that the residual differences in summer months are too small to
be significant but that it is probable that real differences occur
in winter  in both cases the minimum probable correlation for the
swansea slough comparison is very high
   /
4586
selective annotated bibliography on ionospheric propagation  includes
some references covering the period
   /
4587
measurements of the mean lifetime of the metastable state of the
oxygen atom in the upper atmosphere during auroral displays  the
mean lifetime of the level is found to vary between and
   /
4588
stability criteria for an electrical or mechanical system with distributed
parameters
   /
4589
advances in vibratory power supply techniques  a brief review of
british commercial vibrators  a table of the comparative performance
of three typical vibrator units is given
   /
4590
the germanium junction rectifier  the junction is produced by alloying
a controlled quantity of with a crystal about square and thick with
resistivity about  the manufacture electrical characteristics and
methods of assessing the performance of the rectifier are described
applications are grouped into use with resistive load use with battery
load and pulse and miscellaneous  by virtue of its high efficiency
this rectifier can be used for high powers with comparatively simple
cooling systems
   /
4591
high temperature area type titanium dioxide rectifiers  modifications
in the methods of production including the deliberate introduction
of impurities have led to improvements over the performance reported
previously in respect of maximum operating temperature reverse forward
resistance ratio and reproducibility of characteristics  satisfactory
operation at temperatures above for hundreds of hours is reported
   /
4592
behaviour of as depolarizer
   /
4593
low voltage stabilization  a form of secondary cell is described
having applications to the cathode biasing of valves  it provides
a stable voltage of about which is practically independent of the
current passed  the impedance is and is independent of frequency
   /
4594
the program controlled electronic computer at munich  detailed illustrated
description of a machine designed for calculations on scientific
problems  a binary internal system is combined with a decimal external
system  the word length is binary digit  the magnetic drum store
rotates at mean access time is and capacity is words  teleprinter
tape is used for input and output with photoelectric scanning also
for the input  diodes are used the power consumption is
   /
4595
an accurate electronic multiplier  an account of developments of
the time division multiplier described by  a design giving long term
stability and increased speed of operation is described
   /
4596
magnetic core circuits for digital data processing systems  circuits
for interconnecting toroidal cores used to perform various functions
in digital computers are discussed  a single diode loop permits unconditional
transfer of information from one or more transmitting cores
to one or more receiving cores  a split winding loop permits conditional
transfer and hence logical operations  an inhibit loop is also described
the operation of shift registers cycle distributors counters etc
is explained
   /
4597
a digital potentiometer  description of an instrument developed for
use with a teleprinter perforator for feeding measured voltage readings
into an electronic computer  by comparing the input signal voltage
with a series of reference voltages the former is represented in
integers on a binary or decimal scale  tests on a stage instrument
described indicate that a reliable stage unit with a reading time
under can be constructed with readily available components
   /
4598
the isograph an electronic root finder  the instrument described
is designed on the principle of harmonic synthesis short circuited
and open circuited delay lines fed from a matched frequency sweep
generator being use to produce the sine and cosine terms respectively
by controlling the amount of frequency sweep any desired interval
of the argument can be expanded and the accuracy of measurement thus
increased
   /
4599
character recognition for business machines  arabic numerals are
scanned by a column of photocells whose outputs modulate a pulse generator
system to give signals usable in computers  characters are read
at a maximum rate of operation is not critically dependent on style
or size of type
   /
4600
glossary of terms relating to automatic digital computers
   /
4601
formulas for computing capacitance and inductance  a collection of
explicit formulae in terms of elementary functions legendre polynomials
and functions and elliptic functions  formulae for mutual inductance
and for the forces acting between current carrying coils are also
given
   /
4602
new active circuit element using the magneto resistive effect  a
basic circuit is considered comprising a bridge with resistance arms
lying in toil in the bridge diagonal  analysis indicate that bistable
operation is possible with reasonably short resolving time it may
be necessary to operate at low temperature  a design is described
using layers in gaps of shaped electromagnets  tristable operation
is possible but not practical
   /
4603
chlorinated diphenyl capacitors a survey of production technique
advantages of chlorinated diphenyls over mineral oil as impregnants
for paper include higher dielectric strength and higher permittivity
applications include use in power factor correction capacitors
   /
4604
generalization of variation and compensation theorems for parameters
of an electrical circuit  the effect of impedance variations in one
or more branches of a network on the current in one of the branches
is calculated using matrices
   /
4605
thickness shear and flexural vibrations of rectangular crystal plates
analysis is given for the infinite plate the simply supported rectangular
plate and the rectangular plate with one pair of parallel edges
free and the other pair simply supported  for previous work see
   /
4606
the temperature variation of the frequency of at and bt cut quartz
resonators  measured frequency temperature characteristics can be
represented analytically as power series three terms being sufficient
to deal with the temperature range  the influence of the order of
overtone on the temperature coefficient is discussed  see also of
february
   /
4607
calculation of shunt resistances of rhumbatrontype cavities  the
calculation is facilitated by deriving the expression for the shunt
resistance in a form in which the axial electric field strength is
the only independent variable
   /
4608
travelling wave resonator  a circuit comprising a directional coupler
with the secondary arm ports connected to form a continuous loop
is used for storing energy extracted from the primary in a wave which
circulates around the loop  an x band version used in testing for
high power breakdown is briefly described  presented at the national
electronics conference
   /
4609
an expression for the powers of a matrix and its application to iterated
networks
   /
4610
optimum characteristics of linear pulse systems conditions for minimum
distortion of pulses in linear systems  the analysis is applied to
particular filter circuits  the results are embodied in three theorems
   /
4611
a general theory of reactive non dissipative l sections  elementary
theory is developed based on fosters reactance theorem
   /
4612
the design of filters using only rc sections and gain stages  a method
is described of synthesizing filters using rc sections within a feedback
loop  design information is given for high and low pass filters of
and per octave slope and fixed cut off frequency and others of approximately
and per octave slope whose cut off frequency is variable continuously
by the adjustment of a single element
   /
4613
the polar guide a constant resistance wave guide filter  the filter
described comprises a circular waveguide with spaced radial line
cavities by means of which a linearly polarized input wave is converted
to a circularly polarized wave and subsequently re converted  the
device can handle high powers a design for a television vestigial
sideband filter is described
   /
4614
statistical design and evaluation of filters for the restoration
of sampled data
   /
4615
t stub calculation for transmission line filters  a method is presented
which has advantages over earlier methods in respect of flexibility
and ease calculation  it is applicable whether the stubs in a filter
are true reciprocals or not and also in cases where another element
such as an isolating stub is combined with a stub to give a required
frequency response
   /
4616
an oscillator for very low frequencies  a circuit giving sinusoidal
oscillations with periods of or more uses cathode follower connected
triodes as phase shift elements
   /
4617
frequency stability of point contact transistor oscillators  the
duality relation between circuits using the voltage controlled negative
impedance base input characteristic and those using the current controlled
negative impedance emitter input or collector input characteristic
is demonstrated  stabilization criteria for both cases are derived
analytically and are confirmed experimentally
   /
4618
a frequency stable transistor audio oscillator of very simple design
a circuit is described in which a point contact transistor maintains
oscillations by supplying current pulses to a series circuit during
half cycle periods when the emitter is conducting  frequency stability
is improved by including a diode in the emitter circuit
   /
4619
high sensitivity and accuracy pulse trigger circuit  a pulse height
discriminator is described which incorporates a highly stable differential
negative resistance provided by a type multi electrode valve
by virtue of current division between screen grid and anode  this
circuit is compared with that of kandiah in which the negative resistance
is provided by a cathode coupled pair of valves  the discriminator
threshold can be set in the range with stability within
   /
4620
subtracting counter using dekatron tubes
   /
4621
active quadripoles with intermediate point earth is earthed  generalized
analysis is presented using matrices  the treatment is suitable for
any valve or transistor circuits that can be considered as series
parallel or parallel series networks and facilitates the development
of some useful new circuits
   /
4622
effect of component tolerances in low frequency selective amplifiers
an analysis  amplifiers with wien bridge or twin t selective feedback
networks are considered  when the networks are designed for maximum
selectivity the factor of the amplifier relatively sensitive variation
network component value this sensitivity can be reduced by suitable
choice of component relative values but a higher gain is then required
to obtain the same selectivity
   /
4623
amplifier stage with monotonically rising response to a step signal
the problem is to combine the monotonic response shortest possible
rise time  starting from consideration of a simple coupling and analysis
based on laplace transforms the coupling circuit giving the required
response is found in the form of a network with parallel vertical
and series horizontal arms
   /
4624
valve amplifiers for very low frequencies  amplifier circuits are
briefly reviewed an descriptions are given of a high gain voltage
amplifier using two triodes and a low output impedance current amplifier
using four triodes in a push pull arrangement
   /
4625
distributed amplifier using tubes with secondary emission  description
of a two stage amplifier with three type valves in each stage having
a gain of a bandwidth of
   /
4626
magnetic amplifier design a practical approach
   /
4627
transistor operating conditions  the use of the collector current
voltage characteristic curves in the designs of earthed base transistors
amplifiers is discussed and numerical examples are given
   /
4628
raising the cut off frequency of transistors  results of experiments
with and transistors support herzogs calculations of the rise of
cut off frequency attainable by connecting a neutralizing inductance
in parallel with the capacitance between collector and emitter
   /
4629
high gain transistor amplifier  the advantages of transistors over
valves as low level high gain amplifiers with low noise properties
are discussed and illustrated by a commercial application in a gramophone
pre amplifiers in which a single transistor stage takes the place
of two or more valve stages
   /
4630
broadband transistor feedback amplifiers  negative feedback amplifiers
involving three cascaded common emitter junction transistor stage
are discussed  with large feedback stability conditions can be determined
with sufficient accuracy by considering the forward and return
paths of the feedback loop separately  the maximum feedback possible
without instability depends on the frequency characteristic of the
transistor current gain this characteristic can be represented with
adequate accuracy by a minimum phase approximation  amplifiers with
overall gain of and negative feedback of are described in which stability
is secured by means of phase advancing networks in the return
path
   /
4631
a comprehensive work on the analysis and synthesis of linear networks
forming one of a series presented by the centre national communications
   /
4632
the general statistical problem in physics and the theory of probability
an extended discussion leads to the conclusion that the problems
of statistical physics in which the theory of probability does not
apply may be more important than those in which it does
   /
4633
quantum theory of fluctuation  on the basis of an analysis of method
of measurement an operator is constructed for the spectral density
of a fluctuating variable the classical dynamic variables are replaced
by time dependent operators  the theory is used to deduce law for
a particular case and to calculate the shot effect for free uncorrelated
electrons
   /
4634
a general approach to hysteresis  a alternative formulation of the
domain model  a comparison is made of various methods of formal representation
of hysteresis phenomena in terms of a domain model  a symmetrical
treatment is developed permitting the equations to scanning curves
within a hysteresis loop to be written in a simple form
   /
4635
improved value of the velocity of light derived from a band spectrum
method  a more accurate result than that reported previously has
been obtained by using a new interferometric technique  the new value
is
   /
4636
theory of scattering by an inhomogeneous solid possessing fluctuations
in density and anisotropy
   /
4637
memorandum on electrical and magnetic units  digest of a paper presented
to the society  the various units systems in use are examined disadvantages
of the and systems are indicated  a new system is proposed called
the this is based on four fundamental units and retains the practical
units such as the volt  together with unity values for the dielectric
constant and permeability of vacuum
   /
4638
the electron phonon interaction according to the adiabatic approximation
   /
4639
superconductivity at millimeter wave frequencies  preliminary results
of experiments on at frequencies between and are reported residual
resistivity is observed at these frequencies
   /
4640
the electron affinity of hydrogen in a microwave gas discharge  experiments
show that hydrogen in a microwave gas discharge is a much better
electron captor than its calculated capture cross section would indicate
giving de ionization times in t r switches comparable with those
obtained with water vapour
   /
4641
disappearance of adsorbed gases from dielectric surfaces under electrodeless
discharge
   /
4642
studies of externally heated hot cathode arcs the low voltage form
of the ball of fire mode discussion in terms of a model based on
the observation that the stream of electrons entering the ball plasma
from the cathode plasma is scattered so completely that the electrons
within the ball have a maxwellian energy distribution  theoretical
predictions are compared with probe measurements
   /
4643
ionization and desorption due to strong electric fields  experimental
investigations of the intensity distribution of field type electron
emission from single crystal points covered with thin films of other
material are reported  where surface compounds of with or are present
a characteristic change of the emission distribution is observed
after application of an opposing field  the change is attributed
to local ionization an electron being released into the interior
of the metal and a positive ion being emitted into the vacuum if
the field is strong enough to overcome the image force  the field
ionization of physically adsorbed molecules or atoms requires relatively
strong fields  quantitative estimates are made of the pull off field
strength and its temperature variation
   /
4644
a method for the systematic calculation of an electron optically
effective field distribution with specified imaging properties  analysis
is given for a purely magnetic field
   /
4645
high field electron emission from irregular cathode surfaces  the
enhancement of the field in front of an emitter due to surface irregularities
is studied in detail with reference to mechanisms proposed
by and by  the enhancement factor varies with distance from the surface
and is also field dependent  the results afford and explanation of
anomalous conduction variations in liquids and gases
   /
4646
space charge effects in electron optical systems  a discussion of
spherical aberration in beams exhibiting a waist  conditions for
transition from waist to cross over are examined  experimental results
support the theory
   /
4647
mean free path for discrete electron energy losses in metallic foils
   /
4648
transmission of electrons of energies below aluminium oxide films
of thickness
   /
4649
critical examination of the theory of plasmas based on mean free
path in the light of the method based on the distribution function
derived by solving boltzmanns equation  discussion indicates that
the distribution function method is more suitable than the mean free
path method for calculating the conductivity of anisotropic plasmas
velocity analysis of thermionic emission from single crystal tungsten
it is suggested that the departure from a maxwellian distribution
observed by hutson is due to the finite resolution of the analyser
   /
4650
spin deviation theory of ferromagnetism
   /
4651
the origin of ferromagnetism in transition metals  analysis of experimental
evidence indicates that the energy band concept constitutes
a more satisfactory basis for the theory of ferro magnetism than
the hypothesis that the magnetic carriers are bound to individual
atoms  the occurrence of fractional number of carriers is explained
on the basis of close range interactions between carriers associated
with the same atom  the absence of ferromagnetism in heavy elements
such as a consequence of strong spin orbit coupling
   /
4652
influence of crystalline electric fields on antiferromagnetic transitions
   /
4653
on the ampere force  a re examination of the expressions for the
force taking account of war burtons comments
   /
4654
source representations for debyes electro magnetic potentials  theory
of radiation presented is discussed debye potentials can be used
for all points  even within the source distribution  this leads to
an alternative methods for the direct determination of multipole
expansions
   /
4655
electrodynamics of turbulent ionized media  the scattering of power
in a turbulent ionized medium is discussed  to be applicable for
arbitrary values of electron density analysis should take account
of multiple scattering  suitably modified forms of naviers equations
are indicated
   /
4656
subharmonic oscillations in a nonlinear system with positive damping
   /
4657
theory of total reflection  the theory of total reflection of an
elliptically polarized plane wave is developed from expressions for
the energy density and the poynting vector using the notation of
the earlier paper  results indicate that at total reflection the
mean flow of energy in the refracted wave contains a com ponent normal
to the plane o incidence this component is zero in non total reflection
and in two special cases its magnitude is proportional to the wavelength
in the first medium
   /
4658
maximum transmission of electromagnetic waves by a pair of wire gratings
an experimental investigation was made of the transmission waves
through a pair of parallel wire gratings with various wire and grating
spacings for various angles of incidence  results are compared with
values derived from theory
   /
4659
semi asymptotic series for the diffraction of a plane wave by a cylinder
the technique described previously involving watson transform
is used to develop series up to where and is the radius of the cylinder
   /
4660
variational formulation of two dimensional diffraction problems with
application to diffraction by a slit  diffraction particularly of
waves is discussed  analysis shows that for incident plane wave the
complex amplitude of the far zone diffracted field can be expressed
in a stationary form of the type indicated by levine schwinger  the
case of a diffracting slit of infinite length and finite width treated
in detail  for normal incidence the results agree with those
   /
4661
on integrals occurring in the variational formulation of diffraction
problems
   /
4662
the diffraction of electromagnetic waves at a grating consisting
of parallel conducting strips  a rigorous solution is given for diffraction
of a normally incident plane wave the width of the strips being
equal to the spaces between them  graphs show the reflection and
transmission of the wave for various ratios of strip width to wavelength
and the amplitudes of the diffraction spectra
   /
4663
diffraction of centimetre waves by a conducting sphere in a waveguide
measurements were made at a frequency of using a hybrid arrangement
results indicate that reflection coefficient is proportional to sphere
volume dispersion of results is attributed to small geometrical irregularities
the work is preliminary to a study of the diffraction of
waves by clouds
   /
4664
scattering of electromagnetic waves from a random surface  the medium
below the surface is assumed to be perfectly conducting so that the
far zone form of the stratton chu solution can be used  the mean
and covariance of the approximate expression for the scattered radiation
are determined for both vertical and horizontal polarization
   /
4665
interaction of electromagnetic waves of radio frequency in isothermal
plasmas collision cross section of helium atoms and ions for electrons
theoretical and practical aspects of the laboratory experiments described
previously are discussed and results of measurements using he
gas are presented  the ratio of the effective cross sections of ions
and atoms for electron collisions is about at an ion density of at
room temperature
   /
4666
nonlinearity of propagation in ferrite media  measurements are briefly
reported  both losses and phase shift varied with temperature at
constant power level  the results are compared with those of
   /
4667
investigations on artificial dielectrics at micro wave frequencies
the transmission of a wave through a parallel plate array was studied
experimentally  the observed variation of phase change with angle
of incidence is in fair agreement with that calculated from the formula
given by the difference between them is attributed to diffraction
effects and the presence of higher order modes inside the array
values are deduced for the minimum dimensions required to avoid diffraction
effects
   /
4668
resonance transitions induced by perturbations at two or more different
frequencies  expressions are derived for the alteration of magnetic
resonance frequency due to the presence of a second oscillation at
a nonresonance frequency  applications of the formulae to nuclear
resonance and molecular beam experiments are discussed
   /
4669
improvement in a paramagnetic electron resonance spectrograph  application
to the study of diphenylpicrylhydra  the sensitivity of apparatus
operating in the band is greatly increased when the klystron source
of nominal power is replaced by one of much higher power
   /
4670
relaxation times in magnetic resonance  the effect of motion of the
absorption centres on the width of resonance lines is discussed on
the basis of a random walk model and a simple picture is presented
of the electron relaxation processes
   /
4671
some devices for the stark modulation milli meter wave spectrograph
an overall sensitivity of about in the wave range is attained as
a result of appropriate design of stark cell frequency multiplier
lock in detector and square wave generator
   /
4672
thermodynamical theory of galvanomagnetic and thermomagnetic phenomena
addendum to paper noted previously
   /
4673
the optical investigation of the interdiffusion of metals  the technique
used involves the preparation of very thin films of known thickness
   /
4674
fundamental formulas of physics  a valuable reference book for every
physicist
   /
4675
spectroscopy at radio and microwave frequencies
   /
4676
the identification of radio stars  an examination is made of the
possibility that the fainter radio stars classified by are within
our galaxy  the observed coincidences in position of radio stars
and dwarfs appear to be significant
   /
4677
absorption of radiation in the optical emission nebula  this is the
first reported case of absorption of radio waves by an emission nebula
it leads to an estimated electron temperature of for the nebula
   /
4678
east west asymmetry in the formation of new sunspots  analysis of
records covering many years indicates that about twice as many centres
of activity are observed on the eastern half of the solar disk as
on the western half
   /
4679
an new index of solar activity based on ionospheric measurements
the monthly mean relative sunspot number is assumed to contain a
component constituting a direct index of solar activity together
with an error component having a standard deviation of about  a new
index based on an analysis of the critical frequency of the layer
over the period has been constructed whose residual error component
is only one tenth that  the magnitude of for a given month is computed
from the mean noon layer critical frequencies at slough huancayo
and watheroo and is based in effect on a calibration of the layer
critical frequencies in terms of
   /
4680
accuracy of solar flare observations  the division of observed solar
flares into more than three classes is not statistically justifiable
more uniform and detailed reporting is required
   /
4681
solar filaments and geomagnetic disturbances  experiments to test
kiepenheuers suggestion identifying the solar regions causing geomagnetic
disturbances with dark filaments on the solar disk gave negative
results
   /
4682
the influence of the solar eclipse on the propagation of atmospherics
in the frequency range  a map shows the position of sources of atmospherics
in europe at the time of the eclipse records of measurements
over a two hour period show a marked eclipse effect on with a delay
but little effect on  an anomalous increase of field strength on
is related to the reduction of the ionosphere earth duct cut off
frequency resulting from the eclipse
   /
4683
the stability of a homopolar dynamo  the stability of the self exciting
disk dynamo is considered taking into account the friction at the
axle and the effect of an external electrical load in parallel with
the field coils  possible analogies between the results obtained
and the motion of an electrically conducting fluid in a magnetic
field are discussed the theory may be useful in explaining the magnetic
field of the earth and of sunspots
   /
4684
a method for the elimination of slow variations in the recording
of pulsations of the geomagnetic field
   /
4685
the diurnal variation of irregular geomagnetic fluctuations  the
diurnal variation o the fluctuations showing a maximum in late evening
for middle latitudes is correlated with atmospheric turbulence in
the ionosphere which is assumed to be hindered in daytime by electromagnetic
damping  there is also a pronounced seasonal effect this may
be connected with the large scale circulation of the atmosphere
   /
4686
thermal and gravitational excitation of atmospheric oscillations
previous work is extended to include a unified treatment for both
gravitational and thermal forcing functions  from consideration of
various atmospheric models it appears that thermal effects are far
more important than gravitational ones in producing the solar semi
diurnal pressure variation this is not confirmed by observation but
the disagreement may be eliminated by assuming the possibility of
heating other than by ground eddy currents
   /
4687
nitrogen oxides and the airglow  possible chemical and photochemical
reactions which would account for the formation of nitrogen oxides
in the upper atmosphere are discussed and are shown to provide a
possible explanation of the airglow
   /
4688
on the cooling of the upper atmosphere after sunset  cooling in the
and regions of the ionosphere is investigated theoretically assuming
that heat transfer takes place only by conduction  at a time after
sunset the temperature is unchanged at altitudes below at a height
of the maximum drop is  there should be an appreciable increase of
ion density in the layer but this will be offset except in equatorial
regions by downward diffusion
   /
4689
formation of the lower ionosphere  the available evidence suggests
that ions in the layer are mainly produced by photo ionization of
photo ionization of at its first ionization potential should occur
in the layer and further data are required to decide whether this
layer is caused by such a process or by ionization by soft rays
   /
4690
the measurement of normal layer critical frequencies at night  the
normal layer critical frequency at night is best determined from
absorption frequency curves plotted as  results of typical measurements
taken with standard absorption measuring equipment are shown  from
the trend of variation it was possible to identify the associated
absorption band on a few of the routine night time curves obtained
at slough in spite of the presence of and other irregularities  from
the variation of with time a recombination coefficient of about was
deduced but owing to the low transmitter power measurements of could
not be made further work with higher power is needed
   /
4691
night time measurement of positive and negative ion composition to
by rocket borne spectrometer  during a flight on only positive ions
of mass number were detected in the region  these are identified
as  ionospheric records for the same period and region show the existence
of clouds
   /
4692
viscosity in the region  it is shown that viscosity is of primary
importance for disturbances whose scale is smaller than the mean
free path and cannot be described by an effective coefficient any
initial disturbance on such a small scale will disappear very rapidly
assuming normally accepted values for a altitude it follows that
patches of ionization causing the twinkling of radio stars cannot
be due to turbulence in the neutral gas as suggested by
   /
4693
changes in the absorption of cosmic noise observed during two ionospheric
disturbances  curves are given showing the observed time variation
of total absorption at at the period of ionospheric disturbances
on  following the suggestions of increased absorption is shown to
be correlated with increased and is presumably due to region attenuation
deductions are made as to the path and speed of the disturbances
   /
4694
interpretation of ionospheric results during eclipses  accounts published
by various workers of the solar eclipse of have been analysed
using the scale height variation concept introduced by  the vertical
distribution of terrestrial atmospheric temperature varies with latitude
and the recombination coefficient in the layer is
   /
4695
the recombination coefficient in the layer during aurorae  in an
earlier paper a mechanism involving variations in positive ion concentration
was suggested to explain the abnormally high values of recombination
coefficient during aurorae  an alternative explanation assuming
a high value of the negative ion electron ratio is shown to be in
accordance with observed data
   /
4696
variable frequency echo sounding of the ionosphere at oblique incidence
the development of the technique described by is discussed with particular
attention to synchronizing arrangements  records obtained over
two paths are compared with records of vertical incidence soundings
at points on the paths
   /
4697
heights of irregularities giving rise to the fading of waves  a calculation
is made of the relation between phase and amplitude for a wave
propagated through a region of random absorption below the reflection
level results agree with those obtained experimentally  a method
for estimating particle collision frequency in the absorbing region
is presented based on that of from which data regarding the region
may be deduced
   /
4698
polarization of electromagnetic waves for vertical propagation in
the ionosphere
   /
4699
some remarks concerning ionospheric absorption work  irregularities
in the frequency dependence of observed absorption decrements are
attributed to focusing effects due to curvature of the layers involved
in the layer these effects occur particularly with third order echoes
account should be taken of the effect in the analysis of absorption
observations made during conditions of rapid fading
   /
4700
ionospheric wind determination from spaced radio receiver fading
records  direct analysis of the fading patterns of reflected signals
at three spaced receivers can indicate the true ionospheric wind
and changes in orientation of the patterns without assuming any particular
distribution of orientation  a new method of analysis of the
fading records is proposed together with an alternative method of
observation in which a single fixed receiver is used in conjunction
with a second one which is moved in a circle round the first
   /
4701
ionosphere review  consideration of the records of sunspot numbers
and ionosphere data indicates that solar activity may increase rapidly
to reach a maximum in the middle of with the monthly mean daytime
reaching for east west transmissions and for southerly paths by
   /
4702
vertical extent of auroral arcs and bands  measurements on photographs
taken from three stations indicate that quiet arcs and bands are
confined to a narrow layer just about the level  the thickness of
this layer is most often between and and rarely  from the ratio of
the number of arcs and bands to the total number of observed forms
it is inferred that the percentage of auroral time during which the
luminosity is restricted to this layer is
   /
4703
the effect of atmospherics on tuned circuits
   /
4704
magnetic amplifier two speed servo system  a system is described
in which two half wave bridges type magnetic amplifier stages drive
a full wave slave type output stage  design data are presented for
a number of systems
   /
4705
a servo system for digital data transmission  the stability of the
servo system is affected by the quantized nature of the digital data
and by time delays inherent in the transmission and digital systems
a method of synthesis is discussed enabling a degree of prediction
to be incorporated which ensures that the regenerated data do not
lag on the original data under steady state conditions
   /
4706
an electronic supply for use in the calibration of instruments  description
of a high power oscillator amplifier set with phase shift unit
giving an output of at least at unity power factor within the range
from each of two amplifiers  the output voltage does not vary by
more than during the time taken to calibrate point on an instrument
scale
   /
4707
transistor power converter capable of watts d c output  a unit based
on the circuit described previously has been developed giving output
from a input  experimental performance figures are given
   /
4708
thyratron inverter uses controlled firing time  the circuits described
permits control of output voltage without saturable reactor with
improved regulation efficiency and response speed  one thyratron
serves as control tube for extinguishing the conducting power tube
at any desired phase
   /
4709
electronic computers  the main part of this issue is devoted to a
series of papers on digital computers with titles as follows  programme
controlled computers  from the punched card computer to the  micro
program control mechanism  the parallel adding mechanism of the
printing the results from electronic computers  use of the electronic
computer for solving complicated mathematical problems  technical
problems in the development of magnetic drum stores  store resonator
circuit and data input and output for the bull electronic computer
assessment of quality of rectangular ferrites for electronic computers
development of resistances for electronic apparatus  transistors
in computer technique  properties required in germanium diodes for
electronic computers
   /
4710
the design construction and applications of electronic digital computers
a survey of the whole field with a comprehensive bibliography
a wide range of actual and projected applications in science and
industry is discussed including process control and data analysis
   /
4711
a transistor digital fast multiplier with magnetostrictive storage
   /
4712
an electrostatic pulse generator  pulse patterns required in electronic
computers are generated by presenting a probe feeding a tuned amplifier
to a suitably figured track on an insulated rotating drum carrying
a voltage western electronic show and convention los angeles california
the full text or an abstract is given of papers on various components
equipment and techniques presented at the convention  abstracts of
all the papers are published in
   /
4713
the resistance of sheets strips wires tubes and coils of various
materials at frequencies between  a method of calculation applicable
to materials with widely different conductivities ranging from is
presented  the values of the resistance per square are found from
sets of curves for material thicknesses of  because of skin effect
at high frequencies the curves for these thicknesses cover all requirements
   /
4714
concavity of resistance functions  it is proved that any network
linearlys wound potentiometers fixed resistor has a curve of resistance
versus shaft angle which is concave downward
   /
4715
oscillations of coupled windings  digest of paper  using the mutual
inductances functions the integral equation method of determining
the natural frequencies is extended to take account of the effect
of a transformer secondary winding
   /
4716
the transfluxor
   /
4717
symposium on microwave strip circuits
   /
4718
variation with temperature of quartz resonator characteristics  calculations
based on the temperature variation of the piezoelectric constants
of and quartz resonators indicate that the and resonators are particularly
suitable for use in filters at temperatures as high as or over
   /
4719
theory of electromagnetic resonators of almost conical shape  a mathematical
investigation is carried out of oscillations in a resonator
formed by a spheroid and a confocal two sheet hyperboloid for the
case of a small ratio between the focal distance and the wave length
perturbation theory is modified to take into account the large deviation
of the field from that in a resonator formed by a sphere and two
coaxial cones
   /
4720
theory of thin aerials in cavity resonators  free oscillations in
a cavity resonator containing thin metallic aerials or having narrow
slot in its walls are considered  formulae are derived for the natural
frequency and eigenfunctions of such a system and for the decrement
and of the resonator  the results are used in a discussion of the
excitation of a cavity resonator by thin aerials  the problem is
reduced to the excitation of the resonator by given external electric
or magnetic currents  several examples are considered in detail
the analysis is continued in the following paper both tuned and untuned
aerials are considered
   /
4721
a matrix method in the solution of cascaded four terminal networks
   /
4722
the geometrical representation of the parallel and the series reactance
as a loss free parabolic quadripole  further application of the method
described previously
   /
4723
calculations with noise voltages part passage of noise voltages through
nonlinear elements  the correlation function is used to calculate
the modification suffered by a noise spectrum on passing through
a quadripole with nonlinear elements  the method is based on that
of rice  the quadripole characteristic is represented as an integral
the relation between the correlation functions for input and output
voltages is in the form of a double integral which can be expanded
in a power series  simple expressions are obtained when the quadripole
characteristic comprises a sum of hermite polynomials  an introduction
to the various parameters used is given in part
   /
4724
design of microwave filters with quarter wave couplings  resonator
diaphragms are constructed from triplets of inductive posts whose
spacing and radii are chosen to prevent the generation of the first
five non propagating modes  this is sufficient to ensure negligible
coupling at quarter wave separation  measurements on filters at indicate
a satisfactory performance
   /
4725
normalized filter design  the design chart presented for composite
low pass filters permits predetermining the attenuation characteristic
from trial design  six normalized designs are presented as examples
to cover a practical range of stop band loss
   /
4726
attenuators and load materials  preparation of iron araldite mixtures
with ratios of by weight is described and results of loss measurements
in the frequency range are reported  the results are presented graphically
   /
4727
a comparison of the noise and random frequency and amplitude fluctuations
in different types of oscillator  the nature of the random fluctuation
in the output is dependent on the form of feedback employed and
the method by which the output amplitude is controlled  the frequency
band over which the output power is distributed depends however on
the relative magnitudes of signal and noise in the circuit rather
than on the particular circuit employed  the conclusion is that an
oscillator should be operated at as high a level as possible consistent
with stability and constancy of the circuit components
   /
4728
frequency modulation noise in oscillators  the discussion is confined
to noise due to the discrete nature of the electron and the random
motion of the electrons in the oscillator valve the spectrums ranges
from zero to hundreds of  the effect of the usual band pass filter
on the noise modulation is determined and the power spectrum of the
oscillator output is evaluated  the theory is applied to several
types of oscillator
   /
4729
a wide band frequency modulated system with asymmetrical phase oscillator
an analytical investigation is made of the operation of the oscillator
symmetrical and asymmetrical arrangements are compared as regards
linearity of modulation modulation sensitivity and frequency stability
in a system
   /
4730
a phase controlled oscillator  description of an oscillator whose
frequency is an exact multiple of the mains frequency the phase relation
is maintained constant by a feedback loop and phase comparator
   /
4731
a particular mode of relaxation oscillations in a triode valve  operation
of an arrangement witha very high resistance between the grid
and the point of application of grid voltage is discussed  the characteristic
is two valued giving rise to relaxation oscillations
   /
4732
junction transistors with alpha greater than unity
   /
4733
transistorizing meacham bridge oscillators  national electronics
conference paper  highly stable circuits using either point contact
or junction transistors are described for operation at a frequency
of
   /
4734
experiments on the regeneration of binary microwave pulses  a device
consisting of a waveguide hybrid junction with a si crystal diode
in each arm working at signal frequency gives sufficient regeneration
to permit transmission of signals over a long chain of repeaters
providing that the signal noise ratio at each repeater
   /
4735
high speed counter uses surface barrier transistor  the complete
circuit is given of a four stage reversible binary counter used for
decoding signals  the high cut off frequency of the surface barrier
transistors employed permits the attainment of a counting rate of
pulses
   /
4736
time signal generator employing decade counting tubes  in a frequency
dividing circuit operated in conjunction with a frequency standard
and using two decade counters to effect the last stages of division
from fluctuation of delay time for the leading edge of the seconds
output pulse is and for the trailing edge or better
   /
4737
disc seal circuit techniques
   /
4738
stability problems with low frequency amplifiers with transformers
in the feedback path  measurements were made of the attenuation and
phase variation of typical push pull output transformers over the
frequency band outside the low frequency band the phase variation
was compared with that of a minimum phase rotation network with the
same attenuation variation  the results indicate the possibility of
simplifying the stability testing of the amplifier circuit by testing
the transformer as a minimum phase rotation network
   /
4739
e magnetic and negative electric feedback improve performance of
single stage magnetic servo amplifier driving two phase induction
motor and standard position servomechanism
   /
4740
magnetic amplifiers in bistable operation  flip flop operation can
be achieved by over regenerative feedback  the relation of the switching
cycle to the steady state transfer characteristic is examined
   /
4741
a study of transistors connected in parallel  the performance of
the parallel combination of transistors is studied in terms of a
single equivalent transistor whose parameters re related in a simple
manner to those of the individual transistors  expressions are derived
for the gain and the input and output impedances for the three basic
modes of operation  results of experiments with both point contact
and junction types are in good agreement with the theoretical results
   /
4742
a silicon junction diode modulator  by the use of biased diodes in
a specially designed bridge circuit is converted to over ange from
audio frequencies to at least with a zero stability of better than
at room temperature and
   /
4743
theory of the autodyne detector for paramagnetic resonance
   /
4744
use of logarithmic notation in science and engineering  a unit for
general logarithmic systems is proposed termed the jot the notation
used is but the word jot is normally omitted  advantages of the system
are simplicity of calculation economy of notation simplification
of units and simplification of representation of errors  examples
of use of the notation are given
   /
4745
correlation between photons in two coherent beams of light  principles
used in the radio interferometer described previously are applicable
to the measurement of the angular diameter of visual stars if the
two aerials are replaced by mirrors and the detectors by photocells
for operation of such a system it is essential that the time of arrival
of photons at the two photocathodes should be correlated when the
light beams incident on the two mirrors are coherent a laboratory
experiment demonstrating the existence of this effect is described
   /
4746
asymptotic solutions of maxwells equations involving fractional powers
of the frequency  the principal theorem derived indicates the method
of obtaining steady state solutions provided that the behaviour
of the corresponding pulse solutions in the neighbourhood of the
singularities is known
   /
4747
mathematical study of boltzmanns equation
   /
4748
diffraction by a plane aperture with variable contour  four dimensional
extension of the formulae of classical diffraction theory of
   /
4749
some theoretical and practical considerations of the johnsen rahbek
effect  the johnsen rahbek effect which is observed when a voltage
is applied between metal and semiconductor surfaces in contact with
one another is explained as due to the force across the gap which
exists at all points except a few where contact is actually made
the force increases with the voltage until the latter reaches the
critical value causing field emission  experiments with a clutch
based on this effect are described the results indicate that such
a device would be too unreliable for practical purposes the effect
might be used in relays and gas flow valves
   /
4750
dielectric properties of a lattice of anisotropic particles  analysis
is presented for a uniform lattice of similarly oriented particles
of arbitrary shape and material  the packing density is assumed to
be such that interaction between particles must be considered but
the induced fields can still be regarded as simple dipole fields
two particular cases are examined a cubic array of ferrite spheres
and a tetragonal array of disks in the latter case the calculated
values of dielectric constant are in good agreement with experimental
results reported by
   /
4751
electronic interaction between adsorbed gas molecules and metal surfaces
the interaction is discussed in terms of the structure of the
gas molecules and the work function of the metal  experimental investigations
based on the variation of photoelectric sensitivity and resistance
of thin films of the metal on adsorption of the gas are described
metals used were ni and pt gases were water vapour and benzene vapour
the investigation is relevant to the problem of conduction at the
surface of semiconductors
   /
4752
the diffusion of electrons in a gas at low temperatures  laboratory
measurements were made of electron agitation energy as a function
of where is an applied electric field the concentration of gas molecules
and the mean agitation energy of the molecules  the gases used were
   /
4753
international symposium on electrical discharges in gases  the text
is given of papers presented at the symposium held at delft in april
the subjects discussed included fundamental processes in gas discharges
instabilities and oscillations in gas discharges high frequency discharges
and the dependence of breakdown on frequency and on the product
of pressure and electrode separation methods of measurement arc discharges
and spark discharges
   /
4754
study of the induced electric discharge in rare gases  experiments
were performed using a tube of a few centimetres diameter and a frequency
of  aspects investigated included the conditions for starting
the discharge and the radiation from the discharge  theory is developed
giving a quantitative explanation of the experimental results
   /
4755
penetration of electrons and ions in aluminium  the depth of penetration
of to electrons and ions in aluminium has been measured  it has been
found that the thompson whiddington law for electrons does not hold
for electrons having energies less than  the practical range energy
relation obtained for electrons in aluminium was found to be where
is if is expressed in and in microns  the practical range energy
relation for light ions in aluminium was found to be where  results
are compared with those obtained by previous observers
   /
4756
use of the knife edge method to determine aberrations of deflected
electron beams  the beam is caused to throw a shadow of a knife edge
or wire on a distant plane  theory is given and selected shadow pictures
are reproduced
   /
4757
collective oscillations and characteristic electron energy losses
an attempt is made to give a simple theory of the interaction of
fast electrons with thin films of solids adequate for interpreting
results of past experiments and for suggesting new crucial tests
   /
4758
secondary electron emission from thin layers of be  an experimental
investigation is reported of the secondary electron emission coefficient
and the variation of secondary electron energy distribution with
the thickness of thin layers of be  for approximately monatomic layers
of be on ni or ag and constant primary electron energy the secondary
electron energy at which the maximum of the versus curve occurs is
a minimum
   /
4759
secondary electron emission from thin layers of silver  an experimental
investigation of ag films on ni or be base
   /
4760
plasma oscillations at extremely high frequencies  the analysis presented
is applicable to plasmas in impurity semiconductors as well as
those in gas discharges  the design of generators based on standing
waves in such plasmas is considered electron densities of the order
of are required  in a system discussed an electron beam is shot into
the plasma which is confined between two parallel reflecting surfaces
these may be the faces of a wafer of semiconductor whose thickness
determines the natural oscillation frequency  problems introduced
by the slowing up of the electron beam in such a system are indicated
   /
4761
magnetic systems associated with systems of permanent electric currents
and their application to the numerical calculation of fields  by
superposing magnetic shells associated with the elementary tubes
corresponding to arbitrary distribution of currents the associated
magnetic systems are simply determined  in this way a scalar potential
inside the currents can be defined
   /
4762
derivation of an expression for the scalar potential of a line current
in the form of a curvilinear integral
   /
4763
calculating the distance between equivalent poles of a bar magnet
   /
4764
the barkhausen effect  the only feasible mechanism to account for
the phenomena associated with the barkhausen effect is one in which
the movement of a limited section of a domain boundary is delayed
by a nonmagnetic inclusion whose cross sectional dimensions lie within
the range  hysteresis losses in ferromagnetic materials may be reduced
by the selective reduction of the number of inclusions whose size
is within this critical range
   /
4765
temperature dependence of ferromagnetic anisotropy in cubic crystals
theories advanced by zener and by van vleck are reconciled they afford
respectively low and high temperature approximations to the same
physical picture namely an anisotropy decreasing with rising temperature
due to statistical fluctuations from alignment of anisotropically
coupled neighbour spins
   /
4766
a discussion on magneto hydrodynamics  the text is given of papers
presented at the discussion noted previously
   /
4767
some exact solutions of the lorentz invariant problem of the motion
of two electric fluids
   /
4768
some problems on obstacles placed in the path of electromagnetic
radiation  the relations between the incident reflected and refracted
fields at the surface separating two media are studied using vectorial
analysis with a system of coordinates attached to the surface  both
media may be dielectrics or one may be conducting  the plane separating
surface is discussed first and the analysis is extended to treat
diffraction by a sphere exact formulae are derived for the re radiation
gain and the total diffusion surface
   /
4769
tensor scattering matrix for the electromagnetic field  theory presented
previously is extended to treat the vector field and to include absorption
   /
4770
interaction of centimetre waves with plasma in the presence of a
magnetic field  experimental evidence of self interaction was sought
using an wave of frequency in a circular waveguide containing a continuous
discharge parallel to the direction of propagation and a transverse
magnetic field  absorption was observed passing through a maximum
at the field strength value corresponding to the gyrofrequency  an
expression for the modulation depth is derived in terms of carrier
frequency gyrofrequency and modulation frequency  the term self interaction
is preferred to self demodulation since the modulation depth
may be either increased or decreased depending on the circumstances
further experiments were made by transmitting an unmodulated wave
through a plasma oscillating at low frequency in a eon tube of length
the wave became strongly modulated the form of the wave envelope
was modified greatly by application of a magnetic field while the
modulation disappeared completely at the field strength corresponding
to gyromagnetic resonance
   /
4771
absorption of microwaves and radio waves in phenol cyclohexanol and
bromo  chloroethane
   /
4772
new method for the observation of hyperfine structure of in a maser
oscillator
   /
4773
nuclear magnetic resonance in very weak fields  a radio spectroscope
for observation of resonance between  the apparatus is described
in detail  the signal noise ratio is calculated and the result compared
with values obtained experimentally  study of nuclear magnetic resonance
between  proton resonance experiments are described  variation of
resonance curves with amplitude and with the characteristics of
the scanning field is investigated
   /
4774
theory of the autodyne detector for paramagnetic resonance
   /
4775
observation of nuclear quadrupole resonances with a coaxial cavity
spectrometer  a note on the construction of a spectrometer based
on a two cavity klystron oscillator and its operation in the range
   /
4776
the stability of the equilibrium configuration of a current carrying
wire in a magnetic field  the problem is considered in relation to
the investigation of the trajectories of charged particles by the
floating wire method as discussed by loeb  analysis shows that in
certain cases when the field has focusing properties the configuration
of the wire is unstable  application of the results to a betatron
problem is briefly indicated
   /
4777
interplanetary magnetic fields and cosmic rays  a discussion of the
implications of the hypothesis that as a result of solar corpuscular
emission a field free region is produced round the sun with a mean
radius of the order of times the distance between the sun and the
earth
   /
4778
the measurement of the angular diameter of two intense radio sources
an interferometer using post detector correlation is described and
results of measurements of the diameter and structure of the radio
stars cygnus a and cassiopeia a are given  the interferometer operates
on and uses aerials spaced at up to the remote aerial being connected
via an radio link to the correlator
   /
4779
apparent intensity variations of the radio source hydra a  over a
period of months about observations of the intensity of hydra a were
compared with observations on other strong sources  the results indicate
that hydra a is relatively much more variable though no periodic
changes have been detected  possible mechanisms producing the intensity
changes are considered
   /
4780
rotation and other motions of the magellanic clouds from radio observations
the motions have been studied by means of line radiation from
interstellar hydrogen
   /
4781
the angular size of the variable radio source hydra a  preliminary
observations on suggest that the size as well as the intensity of
this source varies
   /
4782
observations of solar and lunar radiation at millimeters  further
observations have been made using the method described previously
measured values of atmospheric absorption are greater than values
of water vapour absorption calculated by van vleck  the transmittances
of some materials at are tabulated
   /
4783
investigation of sky brightness in the spectral region near during
the solar eclipse of june  the variation of the atmospheric infrared
radiation excited by the incident solar ultraviolet radiation was
investigated  intensity variations observed at wavelengths of and
indicate that the radiation from the corona is richer in ultraviolet
than the radiation from the sun as a whole
   /
4784
the distribution of radio brightness over th solar disk at a wavelength
of centimetres the quiet sun two dimensional observations
   /
4785
solar brightness distribution at a wavelength f centimeters part
the quiet sun  observations were made with a element interferometer
to check staniers results obtained with a two aerial interferometer
the observed limb brightening is reasonably consistent with that
reported by obrien tandberg hanssen whereas stanier found no limb
brightening  the divergences may be related to actual differences
consequent on the changing phase of the solar cycle
   /
4786
correlation among magnetic storms solar phenomena and cosmic ray
storms
   /
4787
movements in the ionosphere  report of royal astronomical society
discussion held in november  methods of measuring the movements and
results obtained are briefly indicated  an important piece of new
information about the lower region is tha simultaneous observations
on large scale ripples and the small scale irregularities producing
fading show that these two types of irregularity travel with the
same speed
   /
4788
movement of sporadic ionization  the horizontal movement of patches
of daytime sporadic ionization has been observed by using system
of spaced pulse transmitters and a central recorder  the directions
of movement are mainly between  these velocities differ in direction
from the region disturbances recorded at the same time and have only
about half the speed
   /
4789
electronic collisional frequency in the region over calcutta  determinations
of the collision frequency were made on the basis of appletons
formula relating ionosphere reflection coefficient with the difference
between the group and optical wave paths whithin the region  values
corresponding to different heights in the layer are tabulated  the
most probable value is electron
   /
4790
on the influence of electron ion diffusion on the electron density
and height of the nocturnal layer  the influence of the earths magnetic
field on electron ion diffusion will tend to reduce the atmospheric
density in the region at night a lower limit for the maximum density
of the value suddested in the earlier paper is possible  other considerations
tend to confirm the value originally suggested which agrees
with extrapolations from rocket data if the true height of the layer
is about
   /
4791
on the occurrence of spread echoes in the region over japan  analysis
of published ionospheric data for japan for the period suggests that
spread echoes occur more frequently in the north than in the south
chiefly at night at the solstices and when solar activity is weak
echoes of the most common type are attributed to reflections from
irregularities in the upper regions of the layer which are normally
masked in daytime others may be due to reflections from turbulences
during magnetic storms of to ionized clouds passing through the normal
layer
   /
4792
photoelectric studies of the night sky light  an attempt is made
to correlate variations of night glow intensity with those of electron
density in the layer the results are inconclusive
   /
4793
russian ionosphere terminology  russian equivalents are given for
about english terms
   /
4794
effect of the solar eclipse on the lower parts of the ionosphere
and the geomagnetic field  changes in layer electron density observed
at a number of stations during the solar eclipse of have been examined
and the resulting changes in conductivity deduced  the effects are
found to exist over a very much wider area than that eclipsed  the
calculated modifications in the current consequent upon the electron
density changes provide a satisfactory quantitative explanation of
changes in the earths magnetic field at the time of the eclipse
   /
4795
lunar tide in sporadic at brisbane  an analysis has been made of
night time values of for the period results are tabulated and plotted
on a harmonic dial  the semidiurnal variation has a mean amplitude
of and a mean phase of  results are compared with those of
   /
4796
the electrical conductivity of the ionosphere and disturbances of
the geomagnetic field at audio and lower frequencies  on the basis
of assumed values for collision frequency and maximum electron density
for the and layers values are calculated for the conductivity parallel
and perpendicular to the magnetic field and for periods corresponding
to certain critical frequencies  the significance of the results
is discussed in relation to the possibility of extraterrestrial origins
for geomagnetic field disturbances
   /
4797
daily variations of the electrical conductivity of the upper atmosphere
as deduced form the daily variations of geomagnetism equatorial zone
   /
4798
studies on the disturbances in layer associated with geomagnetic
disturbances  reports on work published previously are collected
and discussed
   /
4799
radio observations of the ionosphere at oblique incidence
   /
4800
preliminary studies of the distribution of auroras in alaska  the
analysis of auroral observations for from five stations spread over
alaska shows a zone at geomagnetic latitude for which the incidence
of auroras is independent of magnetic activity  at geomagnetic latitudes
south of the incidence of auroras is markedly dependent upon magnetic
activity
   /
4801
auroral heights over west central canada  results of an analysis
of parallactic photographs of aurorae taken in at chesterfield suggest
that auroral heights in this region are slightly greater than those
observed from norway  there is no definite evidence of a change of
height with time after sunset
   /
4802
observations of whistling atmospherics at geomagnetically conjugate
points  comparison of records obtained at points in n america and
the new zealand appear to confirm storeys theory that whistlers and
swishes are produced as the atmospherics travel along the dispersive
paths constituted by the geomagnetic flux lines between the northern
and southern hemispheres
   /
4803
mains voltage stabilizers  a fast acting stabilizer is described
combining features of the magnetic and feedback types  the voltage
sensitive element is a bridge containing an indirectly heated thermistor
a stability to within over the temperature range can be achieved
for mains voltage fluctuations between and mains frequency variations
between and and load variations from no load to full load  recovery
time is cycles
   /
4804
nuclear batteries types and possible uses
   /
4805
depolarization of electrochemical cells containing manganese dioxide
   /
4806
recent patents on electrical accumulators  for previous review see
   /
4807
a mechanical binary decimal converter
   /
4808
an electronic generator for functions of two independent variables
a unit built at the chalmers university of technology is described
the function is recorded on a photographic plate in the form of variable
width columns these are scanned by a tube  the output is either in
the form of width modulated pulses or in the form of a voltage proportional
to the function
   /
4809
measurement of correlation coefficient  the determination of the
correlation coefficient of noise is based on the measurement of the
coincidences of sign of rectangular pulses triggered by the incoming
signals  the instrument is described in detail and the theory of
operation is given
   /
4810
shock spectrum computer for frequencies up to  an arrangement for
investigating the effects of mechanical shock on electronic equipment
installed in guided missiles comprises an analogue computer which
operates on an accelerometer signal either direct or recorded and
solves the differential equation for the part involved the result
being displayed on a screen  the computer can be tuned up to thus
covering the range within which the fundamental resonance of any
delicate structure is likely to occur
   /
4811
transistor digital computers  a brief account is given of circuit
techniques involving the use of transistors and ferrite two stage
storage devices described at the convention on digital computers
held in london in
   /
4812
the cryotron a superconductive computer component
   /
4813
the gas filled diode as a digital storage element
   /
4814
proceedings of the eastern joint computer conference
   /
4815
parallel connected nonlinear impedances  analysis based on a matrix
method of representing complex vectors and locus diagrams are used
to determine the equivalent single impedance for an arbitrary system
of parallel impedances values of voltage resulting from given current
loads and of current resulting from given applied voltages are hence
derived  the methods are illustrated by a numerical example taking
two nonlinear impedances with ohmic resistance components  the complete
working diagram of the parallel system is obtained by combining the
locus diagram with the characteristic
   /
4816
subminiature transformers and transductors  limitations associated
with subminiature design are discussed in relation to audio and control
frequency transformers and transductors  below a certain size a toroidal
shell construction has given results comparing favourably with laminated
assemblies the signal power level of the transformers is sufficient
for junction transistor circuits  when this construction is applied
to transductors the excitation and control field are orthogonally
related  a paper covering much of the same ground appears in
   /
4817
transformer miniaturization using fluorochemical liquids and conduction
techniques
   /
4818
the stability of thermistors  experimental results indicate that
though the constants of two thermistors tested undergo changes over
a period of months the changes are slow enough for temperature measurements
to be made to an accuracy within over a range of in experiments
lasting up to
   /
4819
design of modern winding machines  a short review in which and european
methods are contrasted
   /
4820
transfer function of relays with inactive zone and hysteresis  the
equation of transfer for the relay is calculated by the laplace transform
method
   /
4821
the cryotron a superconductive computer component  the study of nonlinearities
in nature suitable for computer use has led to the cryotron
a device based on the destruction of superconductivity by a magnetic
field  the cryotron in its simplest form consists of a straight piece
of wire about one inch long with a single layer control winding wound
over it  current in the control winding creates a magnetic field
which causes the central wire to change from its superconducting
state to its normal state  the device has current gain that is a
small current can control a larger current it has power gain so that
cryotrons can be interconnected in logical networks as active elements
the device is also small light easily fabricated and dissipates very
little power
   /
4822
batching and counting using gas filled decade tubes  a range of units
is described from which a variety of frequency meters batching counters
etc  can be quickly assembled circuit diagrams are given
   /
4823
the impedance of shorted edge wound capacitors  results on the frequency
variation of the impedance of this type of capacitor obtained by
leiterer are discussed using simple mathematics  the analysis is
given first neglecting losses and is then extended to take account
of losses in the dielectric and in the thin metal films  eddy currents
in the projecting contact layer and in thicker metal foils are also
taken into account  the method is used to determine the transfer
impedance of lead through capacitors
   /
4824
the forming of the negative electrode of electrolytic capacitors
an examination is made of the conditions under which undesired forming
occurs formulae are presented for the decrease of the capacitance
on repeated dis charging these enable load behaviour to be predicted
and optimum design to be attained  the theory is supported by experimental
results
   /
4825
principles of transistor circuits  a comprehensive review covering
amplifiers oscillators and flip flops
   /
4826
tolerance limits in matching  curves are given showing the level
of power transfer from source to load for various degrees of mismatch
   /
4827
report of advances in microwave theory and techniques
   /
4828
impedance synthesis without minimization  the synthesis procedure
described for realizing a rational positive real function of the
complex frequency variable by means of a network containing no mutual
inductances is performed in three steps in which the computationally
difficult minimization process is avoided
   /
4829
the geometrical representation of combined linear quadripoles  concepts
of non euclidean geometry are used  the representation of reactance
quadripoles by a rigid system of two straight transformation lines
and the determination of impedance transformations from geometrical
reflections afford useful methods for treating composite quadripoles
   /
4830
the geometrical quadripole representation of the double transformer
the representation is effected by adapting the technique described
previously
   /
4831
the operating parameter cascade matrix of quadripoles
   /
4832
waveguide filters  filters having high and low insertion loss are
produced by arranging inside a waveguide a number of suitably spaced
dielectric sections constituting transformers
   /
4833
band pass characteristics of low asymmetry  an empirical design procedure
is formulated leading to filter networks which compare favourably
with conventional designs
   /
4834
new rejector circuit  a circuit used in some colour television receivers
is described  it uses a conventional parallel trap connected into
circuit via a centre tapped bifilar wound coil with a resistance
across one half it is characterized by negative inductance and capacitance
the circuit is discussed further in
   /
4835
a double slab ferrite field displacement isolator at  brief description
with performance figures of an isolator comprising a waveguide with
two slabs of ferrite arranged with transverse symmetry and subjected
to equal but oppositely directed magnetic fields the forward loss
is over most of the range from to and varies by over any channel
while the reverse loss is
   /
4836
impedance transformation of linear terminal networks  if outlets
of a terminal network are terminated by variable reactances the resulting
quadripole represents a variable transformer  as the value of
these reactances varies between the input impedance assumes all values
of the transforming range  this range does not include the entire
right hand half of the complex impedance plane but only circular
areas thereof  an equation is derived for determining these circles
the method is demonstrated in relation to a waveguide hybrid t
   /
4837
fluctuations in self oscillating systems of thomson type  amplitude
and phase fluctuations in weakly nonlinear selfoscillating systems
are considered using a symbolic differential equation describing
the fluctuations of the random functions and the methods of the correlation
theory  a system with one degree of freedom is considered first
and the general theory is applied to the case of a valve generator
operating in the soft state  the theory is then applied to passive
systems with one and two degrees of freedom  the effect of stabilizing
the frequency of an oscillator by means of a high circuit is discussed
the method of taking into account thermal fluctuations shown
   /
4838
fluctuation of oscillations of klystron generator  a theoretical
investigation of noise in a reflex klystron is presented  in a typical
case the natural bandwidth of the oscillations is the results obtained
by shimoda are believed to be in error
   /
4839
frequency of the three phase coupled oscillator part non reactive
anode load resistance  report of an investigation of the effect of
different types of cathode impedance on the oscillation frequency
   /
4840
application of junction transistors to the generation of linear sawtooth
waveforms
   /
4841
ahalwo trigger circuits useful as sources of rectangular pulses
a modified eccles jordan circuit having low output impedance and
a development of schmitt cathode oupled trigger circuit are presented
   /
4842
comparison of junction transistor and amplifier valve  the quadripole
equations are developed for the commonly used circuits important
parameters and relations are tabulated  for linear operation the
valve can be regarded from the network point of view as a simplified
limiting case of the class containing both valves and transistors
analysis of a regenerative amplifier with distributed amplification
analysis indicates that the application of distributed amplification
in regenerative circuits such as the monostable multivibrator is
limited by its inherent time delay
   /
4843
component tolerance effects in feedback amplifiers  analysis relating
to and feedback networks is given  resistor variation produces no
asymmetry of the response curve in this respect the feedback amplifier
is superior to the stagger tuned amplifier
   /
4844
a direct current amplifier stage with asymmetrically earthed input
a push pull cathode follower circuit is used with two valves having
dissimilar characteristics and a special resistance coupling the
usual phase reversing stage being omitted  analysis is presented
on the basis of a parabolic approximation to the characteristics
design procedures for ensuring the requisite quiescent current and
linearity conditions are indicated  a numerical determination is
made of the operating point for a circuit using one and one valve
   /
4845
a note on sidebands produced by ferrite modulators
   /
4846
microwave detector
   /
4847
a simple microwave discriminator  a cylindrical resonator with slightly
disturbed symmetry has two closely spaced resonance frequencies for
the mode corresponding to two waves with slightly different propagation
velocities  these can be detected separately by means of rectifiers
a discriminator characteristic s given by the difference of the rectified
currents as a function of frequency  the dimensions of the resonator
for a given frequency can be reduced by capacitive loading  discriminators
of this type are suitable for measurement and control purposes
rather than for demodulation
   /
4848
miniaturization and quality improvement of circuit parts  coils transformers
resistors capacitors quartz crystal units and filters developed
by the nippon telegraph and telephone public corporation are described
and illustrated
   /
4849
circuit technique for generation of electrical test patterns in television
   /
4850
a method of analysing periodicity  a method of analysing an empirical
function such as that corresponding to the record of an oscillation
process is based on asymmetrical rather that symmetrical linear combinations
of ordinates it permits detection of variations of phase as
well as amplitude
   /
4851
theory of radiation  a survey of the application of quantum field
theory to the interaction between charged particles and the electromagnetic
field within this domain it is now possible to calculate any
process with a precision olny limited by the labour of the calculations
   /
4852
intensity of harmonic and combination components in the nonlinear
distortions of complex oscillations  the effect of linear quadratic
and cubic response characteristics on triangular saw tooth and rectangular
signals is considered results are tabulated
   /
4853
ultraviolet absorption of atomic nitrogen in its ionization continuum
the absorption of radiation of by the plasma of a discharge in an
ionization gauge was measured by passing the transmitted radiation
into a spectrograph  various considerations indicate that the absorption
is due to atomic nitrogen the absorption cross section of which is
hence deduced
   /
4854
the physical interpretation of the self acceleration of electrons
the forces governing the motion of electrons are most easily understood
if the point electron is considered as the limiting case of the finite
size electron  for self acceleration to occur it is not essential
that the field energy be infinite but it is important that the mechanical
mass of the electron by negative
   /
4855
measurement of the specific charge o conduction electrons  the theory
of a method of determining by means of a special dynamo is given
the device comprises a pair of concentric coils which together rotate
with angular velocity about an axis parallel to the applied magnetic
field  the rectangular inner coil can also rotate about its own axis
which is perpendicular ot the magnetic field  the two resulting in
the inner coil are due to induction and coriolis force acting on
the conduction electrons  if these are equal then where is the velocity
of light and the magnetic field strength  the estimated experimental
errors are not greater than
   /
4856
potential due to a uniformly charged disk  formulae are derived applicable
to any point the effect of free electron on lattice conduction
the scattering of phonons by electrons is calculated assuming the
usual electronphonon interaction for a parabolic band whose degeneracy
temperature is comparable with the temperature of the lattice  the
contribution to the thermal resistance is given by an exact formula
subject only to justifiable assumptions concerning phonon phonon
inter actions with rising temperature the apparent mean free path
of the phonons at first decreases as but reaches a minimum and then
increases as  energy and momentum conservations then allow only the
tail of the electron distribution to contribute to the scattering
the model is thought to apply to certain observations on germanium
irradiated sapphire and conducting diamond
   /
4857
ionization by relativistic particles  a summary is given of theories
of the relativistic increase of energy loss by ionization and of
the density effect  the experimental evidence as obtained with various
types of counter is discussed and compared with theoretical predictions
over references
   /
4858
the ionization and dissociation of complex molecules by electron
impact  a review covering theoretical and experimental aspects of
collision processes in polyatomic molecular gases  over references
   /
4859
ion oscillations in a cathode potential minimum  a brief theoretical
note
   /
4860
the rotation of plasmoids in a magnetic field  the motion of a luminous
low pressure gas discharge in ne in the presence of a magnetic field
and a superposed field of frequency about was found to be a function
of the anode voltage of the output valve of the generator used
   /
4861
formative time lags in the electric breakdown of liquid hydrocarbons
   /
4862
the work function and patch field of an irregular metal surface
calculations show that the lowering of the work function due to irregularities
of the surface is entirely compensated by a patch field
   /
4863
the breakdown of gases subject to crossed electric fields  the effect
of an auxiliary electric field acting at right angles to a field
on the breakdown stress of various gases is investigated experimentally
when the auxiliary field is unidirectional or of relatively low frequency
its application raises the break down stress but when its frequency
reaches the two fields appear to act independently  a partial explanation
is advanced  the gases studied include air oxygen nitrogen hydrogen
and neon
   /
4864
spin deviation theory of ferromagnetism the non ideal spin deviations
gas
   /
4865
application of the bethe weiss method to ferrimagnetism
   /
4866
classical electrodynamics as a distribution theory
   /
4867
a derivation of generalized microscopic electrodynamic equations
non relativistic  maxwells equations and the constitutive relations
are derived from the classical microscopic theory without making
use of extensive assumptions so that the effects of the higher order
electric and magnetic moments are retained in the equations
   /
4868
on the theory of stationary waves in plasmas  a mathematical treatment
is presented appropriate to the case of a continuous non vanishing
distribution of particle velocities  a complete set of stationary
plane wave solutions can be constructed  there is no dispersion equation
because for a given wave vector a continuous range of values of frequency
is possible
   /
4869
growing electromagnetic waves  this growth of waves is considered
in terms of baileys electromagneto ionic theory  of the different
wave modes predicted by this theory four are unreal the remainder
comprise two pairs of hydromagnetic waves which become pure waves
at a sufficiently high frequency one pair of modified sound waves
and one pair of modified electron sound waves  the growth of the
waves may result from the trappings of ions between potential troughs
of the space charge wave and the subsequent surrender of energy by
the ions  ion drifts may introduce important effects not indicated
by the wave equations
   /
4870
theory of wave propagations in a gyromagnetic medium  the theory
presented is relevant to propagation in ferrites byt the physical
nature of ferrites is not discussed
   /
4871
on the absorption of microwaves in some substituted phenols in the
liquid state
   /
4872
possible source of line width in ferromagnetic resonance  brief theoretical
discussion indicating the effect of the finite size of a sample
on the dispersion of relaxation times
   /
4873
the displacement of atoms in solids by radiation  a survey covering
theoretical and experimental aspects of the irradiation of solids
by particles or rays effects produced in metals and semiconductors
are described  nearly references
   /
4874
halo of radio emission and the origin of cosmic rays  observations
of radiation from nebulae indicate that a large fraction of the radiation
comes from roughly spherical regions centred on the galactic centre
and having radii of about kiloparsecs  the particle density and energy
conditions in these regions are considered in relation to the acceleration
of cosmic rays
   /
4875
a search for radiation from jupiter at and at  following the observation
of radiation from jupiter at records obtained at cambridge england
of radiation received at and were searched for evidence of radiation
from jupiter at these frequencies results were negative  inferences
are drawn regarding the source of radiation on jupiter
   /
4876
characteristics of radio echoes from meteor trails the distribution
of meteor magnitudes and masses  the distributions are deduced from
observations of sporadic meteors and various showers
   /
4877
characteristics of radio echoes from meteor trails polarization effects
the theoretical estimates of plasma resonance effects by were tested
at a frequency of  the polarization effects observed are in good
agreement with the predictions for both short and long duration echoes
but some unexpected results were obtained for meteor trails with
line densities in the transition region of electrons  the echo amplitude
was found to be proportional to instead of the predicted where is
the duration of the echo  the discrepancy may be the result of diffusion
by turbulence in the atmosphere
   /
4878
meteor echo durations and visual magnitudes  the statistical relation
between the radio echo duration and the visual magnitudes was analysed
using observations obtained during the years on about meteors  over
a range of magnitudes the relation is linear or nearly linear  it
is inferred that a meteor of absolute magnitude produces electrons
per of path length
   /
4879
radar echo duration and height of a perseid meteor  triangulation
data for a meteor echo lasting observed on are discussed
   /
4880
daily maps of the sun  a brief note announcing the inauguration of
a service in which a number of observatories are cooperating to produce
comprehensive records of solar phenomena
   /
4881
solar corona and geomagnetism  both coronal activity and geomagnetic
disturbance vary directly with general solar activity except at the
period of sunspot minimum when correlation between the two is negative
geomagnetic disturbance is greatest when the earth is in the radial
line of an active coronal centre  an active centre appears to have
a shielding effect on the outflow of corpuscles from the undisturbed
solar areas
   /
4882
a model for the solar enhanced region at centimeter range derived
from partial eclipse observations  records taken at three japanese
observatories on frequencies between and during the partial eclipse
of the sun on show a marked decrease on the observed flux during
the period when a large sunspot group was eclipsed the location size
and brightness distribution of the enhanced radiation region are
derived  a model for the quiet sun having a bright region near the
limb on the equator is also suggested
   /
4883
field in the polar region on absolutely quiet days  analysis of data
for the second polar year indicates that the field which is recognized
as applying to the region between latitudes and also represents the
daily variation in the geomagnetic field over the rest of the earth
for absolutely quiet days
   /
4884
report of observations of geomagnetic variations at aso and naze
during the solar eclipse of
   /
4885
introductory theory for upper atmosphere wind and sonic velocity
determination by sound propagation  theory applicable to a rocket
grenade experiment is developed
   /
4886
the atmospheric ozone as indicator of air streams in the stratosphere
the photo chemical bases
   /
4887
a method of determining the relative amounts of and region absorptions
of medium and short radio waves  the method is based on the concept
of rela ation time the value of which for the layer is appreciably
different from that for the layer
   /
4888
region and the current system  the complete equilibrium equation
for the electron density in a solar controlled ionospheric region
includes a term which depends on vertical drift and is usually neglected
the layer critical frequency is then related to the zenith angle
by the equation where is a constant and for an isothermal region
has the value for recombination and for attachment  values of deduced
from actual observations lie between and these findings are discussed
on the assumption that the variation of results from neglect of the
vertical drift term  the theory is supported by observations of singularities
in the noon curves of latitude for several longitudes these
singularities corresponding to normal values of coincide approximately
with the position of the foci of the current system
   /
4889
a new method of analysing ionospheric movement records  technique
based on optical diffraction systems is outlined  the ionosphere
is provisionally assumed to be a plane reflector and the image of
a ground transmitter in it is regarded as a source of coherent radiation
giving rise to a diffraction pattern on the ground corresponding
to an inhomogeneity moving in or below the ionosphere  from the geometry
of the system a focal length is deduced and when the record of the
diffraction pattern is converted into a variable density photographic
record a corresponding visual focal length is obtained from which
the velocity of the moving inhomogeneity can be determined  the method
has been tried at the new zealand dominion physical laboratory using
aerials arranged at the corners of a triangle as suggested by mitra
holograms showing some results are reproduced from these it is celar
that moving objects far below the ionosphere can affect the records
significantly
   /
4890
movements of irregularities in the region  continuing the work referred
to in results for the period show that an east wind with an average
velocity of predominates in the evening continuing throughout the
night in winter towards sunrise winds in the reverse direction are
frequent  irregularities are estimated to be in extent
   /
4891
sequential and lunar effects on the equatorial  among the various
types of which have been observed one shows apparent vertical movement
on the ionogram and has been termed sequential by investigators at
the national bureau of standards  a study is made of this phenomenon
using records from a number of stations the sub type investigated
is that involving an region which first appears at a height of about
in winter and in summer and then drops to normal level where it persists
for some hours  the latitude and time distributions of the phenomenon
are briefly discussed
   /
4892
on anomalous variations of critical frequencies and virtual heights
of the and regions of the ionosphere  latitudinal and seasonal variations
of critical frequencies and virtual heights of the and layers
for years of high and low sunspot activity are investigated  anomalous
variations are found analogous to those in the layer similar explanations
are suggested
   /
4893
the diurnal and annual variations of ionization  an interpretation
values of and log in the formula calculated from records for are
tabulated  the variation of these values is discussed and a model
is derived for layer conditions in which the temperature gradient
is smaller in summer than in winter
   /
4894
a study of the total electron content of the region of the ionosphere
over ahmedabad  the total number of electrons in a column of unit
cross section in the and regions up to the height of maximum electron
density has been calculated for three magnetically quiet and three
disturbed days in each month from  the method of analysis is that
suggested by assuming parabolic electron density distribution  the
relation between the semi thickness and for the layer shows that
thick layers are associated with higher values of and that the parabolic
distribution law does not hold for very thick layers
   /
4895
determination of the region collisional frequency  the collision
frequency reaches its maximum at about noon and its minimum at about
midnight  the rate of rise of increases with cos
   /
4896
a possible explanation of the drop in region critical densities accompanying
major ionospheric storms  an explanation in terms of increased
recombination rates is suggested based on evidence that the abundance
of at great heights is governed by vertical transport
   /
4897
the spectrum of radio star scintillations and the nature of irregularities
in the ionosphere  simultaneous observations of the intense source
in cygnus were made with a frequency sweep spectroscope a frequency
sweep interferometer and a triangular spaced aerial receiving system
most fluctuations are due to focusing by single lens like irregularities
the fluctuation amplitude shows tow maxima one near midnight the
other near midday  for day time conditions at least the elongation
of the pattern at the ground indicates marked anisotropy in the ionosphere
irregularities
   /
4898
correlation between noon and sunspot number  analysis of data from
four indian stations shows a linear relation between the running
means of the sunspot number and the noon value of up to a limiting
value of
   /
4899
tilts in the ionosphere during the solar eclipse of  directional
measurements at nearly vertical incidence on the layer during the
eclipse showed the existence of a tilt whose direction agreed with
that expected from the geometry of the eclipse  the magnitude of
the tilt was also of the same order as that calculated from observed
changes in the height of reflection  oblique incidence bearing measurements
on signals reflected from the normal layer failed to reveal
any eclipse effect and theoretical calculation showed that no detectably
large effect would have been expected in this case
   /
4900
preliminary results of the ionospheric solar eclipse of  an analysis
of critical frequency data obtained in grahamstown during this annular
eclipse  the effects may be explained to a first approximation by
assuming that the radiation responsible for the ionosphere structure
is distributed uniformly over the suns disk  values of recombination
coefficient for the and layers are in good agreement with values
obrained recently by independent methods
   /
4901
observations of the lower ionosphere during the solar eclipse on
propagation tests were made at on frequencies of during the eclipse
the expected increase of reflection coefficient in the lower ionosphere
was considerably delayed after first contact and normal attenuation
values were restored before the end of the eclipse  the magnitude
of the effect and the delay of the maximum agreed with predictions
from normal diurnal and seasonal variations based on a single layer
model of the layer but the limited duration of the effect was consistent
with a multilayer model  observations of complex variations of very
long wave ve atmospherics are also reported
   /
4902
the influence of the geomagnetic field on turbulence in the ionosphere
damping of turbulent motion of neutral particles is negligible for
the smaller eddies  in the higher regions electrons are constrained
to move nearly parallel to the magnetic field this results in variations
of electron density even when the density of neutral molecules does
not vary  these variations may be appreciable above
   /
4903
on the disturbance daily variations and the lunar daily variations
in the region of the ionosphere on the magnetic equator  continuation
of work reported previously on the effects of vertical electron drift
dur to the electrical fields associated with the currents responsible
for the diurnal geomagnetic variations
   /
4904
layer electron model reduced from considerations of and wave absorption
   /
4905
the propagation hole in the ionosphere
   /
4906
the interpretation of measurements of radio wave interaction
   /
4907
a comparison of the annual mean solar and lunar atmospheric tides
in barometric pressure as regards their worldwide distribution of
amplitude and phase
   /
4908
the influence of individual variations in the field changes due to
lightning discharges upon the design and performance of lightning
flash counters  flash counters responding only to the component of
the field change are likely to be least subject to error this implies
a preferential selection of very low frequencies  examples are given
indicating the extent of the inaccuracies encountered  from statistics
of rates of flashing and duration of discharges it is concluded that
counters should have an insensitive period of about  the design of
counters is discussed and a simple circuit is presented
   /
4909
low audio frequency electromagnetic signals of natural origin  signals
in the frequency range have been recorded in california over long
periods  the diurnal variation of signal amplitude closely resembles
the diurnal variation of atmospheric potential gradients measured
at sea it is inferred that these low frequency signals are atmospherics
and that their mean amplitude is roughly proportional to the number
of storms in progress over the whole world
   /
4910
sunspot and geomagnetic storm data derived from greenwich observations
includes explanatory notes and literature references and some diagrams
   /
4911
a magnetic thyratron grid control circuit  a circuit described previously
is modified by including an source and a rectifier in the secondary
circuit of the grid transformer changing the mode of operation to
that of a reset magnetic amplifier  a range of firing voltage phase
is available the firing voltage builds up rapidly
   /
4912
chemical generation and storage of electricity  a review of recent
work on fuel cells whose operation is based on oxidation of carbon
and hydrogen and which give a low voltage output the particular importance
of this type of cell is that it may give higher efficiency in
the use of primary fuels
   /
4913
some basic scientific problems relating to manganese dioxide electrochemical
cells
   /
4914
the short electronic analogue computer  description o  the design
and operation of a general purpose computer designed for quantity
production and capable of single shot and repetitive operation
   /
4915
tridac a large analogue computing machine  discussion  a detailed
description a shorter account was abstracted previously
   /
4916
function generators based on linear interpolation with applications
to analogue computing  by using suitable combinations of diode circuits
and high gain feedback amplifiers it is possible to generate functions
without restriction to monotonic characteristics  experimental results
are presented for a sin generator in which the error is about of
the maximum output
   /
4917
construction and method of operation of modern integrating equipment
general principles are discussed and a detailed description is given
of an installation in germany  the results are presented to three
or four significant figures by counter mechanisms and in the form
of curves on function benches  curves of empirical functions are
dealt with by photoelectric scanning  errors do not exceed
   /
4918
engineering multistage diode logic circuits  design of computers
using crystal diodes and transistors is discussed  transistor input
circuits directly coupled to multistage logic circuits may avoid
the need for intermediate amplifier stages
   /
4919
transistor circuits for analog and digital systems  a summing amplifier
an integrator and a voltage comparator using junction transistors
are described together with a voltage encoder made up from them for
translating voltages into equivalent time intervals for analogue
to digital conversion
   /
4920
an experimental transistorized calculator  the machine is functionally
identical with the calculating punch but the valves are completely
replaced by transistors and
   /
4921
an multiplier  a relatively simple purely electronic multiplier circuit
for differential analysers is described  working with an upper frequency
limit of for both factors accuracy is within about of full scale
   /
4922
abac of the function for studying the initial complex permeability
of circular cross section conductors at high frequency  the impedance
of the conductor is measured and the parameter is then found from
the abac using a known formula the complex permeability is then derived
using a given relation between and  this abac supplements tht presented
by prache which was not applicable to good conductors
   /
4923
physical sources of noise  the principal types of electrical noise
encountered in circuits and valves are identified and the mechanisms
giving rise to them are discussed  equations used to represent noise
phenomena are derived
   /
4924
the impedance concept  impedances and associated transfer functions
are expressed in terms of a variable which is closely associated with
time differentiation  the fundamental properties of the world are
discussed  a general condition dor an algebraic equation to be free
from roots with positive real parts is obtained a network whose characteristic
equation has this property is stable  conditions are deduced
for a system to have a damping rate at least equal to a specified
value  the effect of adding terms in on the roots of a given cubic
in is examined  the effect on the gain and maximum obtainable feedback
of the addition of a step circuit to a three stage amplifier is considered
in detail
   /
4925
properties and comparative tests on relay contacts
   /
4926
toroidal transformers pass video bandwidths  television video transformers
are wound on supermalloy tape wound toroids having a low frequency
permeability of diminishing with increasing frequency a bandwidth
of is obtainable  these transformers may be used for matching a coaxial
cable and for interstage coupling in transistor video amplifiers
   /
4927
transformer design chart  the chart gives data for designing two
winding transformers
   /
4928
the theory and design of coaxial resistor mounts for the frequency
band a design is described in which the resistive inner conductor
has uniform diameter while the outer conductor has a tractrix profile
lead in cones are designed to avoid discontinuity at the connections
experimental results indicate that the impedance is within of the
resistance with an extremely small phase angle at all frequencies
up to the highest measured namely
   /
4929
the operating mechanism of voltage dependent silicon carbide resistors
measurements on aggregates of sic particles such as pressed powder
show how thermal effects depend on grain size and the duration of
the current pulse  thermal and field effects can be separated by
reference to resistance voltage characteristics at different temperatures
for single contacts between crystals or between a crystal and
a metal knife edge
   /
4930
the specification of the properties of the thermistor as a circuit
element in very low frequency systems  an analysis based on sinusoidal
applied voltages shows that a conductor whose resistance is a function
of temperature may be represented by an equivalent circuit having
a semicircular impedance locus  an expression for the distortion
of the waveform is also obtained and this is found to be small provided
that the alternating current is less than a quarter of t steady polarizing
current which flows in the conductor  the impedance loci of
a bead type thermistor are plotted by means of null technique  a
typical impedance varied from a negative resistance of at very low
frequencies to a pure inductance of and then to a positive resistance
of at high frequencies  the use of the equivalent circuit is illustrated
by designing phase shift networks suitable for use in the stabilizing
of very low frequency control systems  these circuits may be used
in systems where either data transmission is employed
   /
4931
problems encountered and procedures for obtainining short term life
ratings on resistors  account of investigations made at the battelle
memorial institute on the extent to which length of life must be
sacrificed when composition resistors are operating at high temperature
a machine system for handling the data is described
   /
4932
controlled transductors  analysis of the behaviour of the single
core auto self excited transductor is made for the condition when
the control circuit has finite resistance  control of full wave transductors
and some push pull circuits with half wave and full wave outputs
are referred to
   /
4933
the residual time constant of self saturating transductors  theoretical
and experimental evidence is presented indicating that the main winding
of selfsaturating transductor influences the time constant for small
signals to an extent dependent on the blocking intervals of the rectifiers
and on the main winding resistance  the blocking interval is
in turn dependent on the output amplitude this is consistent with
the normal experience that transductor response becomes faster as
the output increases
   /
4934
a digital differential  a simultaneous bidirectional counter circuit
is described in which a dekerence in court between two independent
pulse trains the circuit can also be used in frequency and speed
control applications
   /
4935
electronic switches for television
   /
4936
the effective leaking resistance of several types of capacitors
a rapid method of measuring leakage resistance based on rate of charge
is described  variation of leakage resistance with time was measured
for commercial capacitors of values ranging from with various dielectrics
at temperatures ranging from in most cases  the best properties
were exhibited by a capacitor having a polytetrafluoroethy dielectric
   /
4937
a variable capacitance germanium junction diode for
   /
4938
cascaded feedthrough capacitors  by interspersing lossy ferrite washers
between the stacked ceramic disks of capacitors of the type described
previously the filtering properties for and are greatly improved
such constructions are thus useful for miniaturized low pass filters
properties of suitable ferrites are discussed
   /
4939
national bureau of standards preferred circuits program
   /
4940
invariance and mutual relations of electrical network determinants
work by earlier authors is generalized  the basic values of the impedance
and admittance determinants are connected by a simple relation
involving the determinant of the branch parameter matrix
   /
4941
nonlinear network problems  general analysis is presented for flow
problems a number of theorems are proved  relaxation methods are
used
   /
4942
transformation of the matrices of generalized admittances for various
triode connections  the usual three sets of connections for triode
valves and for transistors are examined
   /
4943
the correlation between decay time and amplitude response  an investigation
is made of the relation between the decay time and the delay
time of the indicial response and the bandwidth and peak values of
the steady state amplitude response for various minimum phase lumped
parameter networks  formulae are derived expressing the functional
relation between decay time and the ratio where is the bandwidth at
and that at  a formula for delay time is derived which is valid for
multistage circuits
   /
4944
energy considerations for growth and decay transients in a simple
resonator circuit  analysis is presented for a series circuit values
of current voltage being determined in terms of the characteristic
resistance  the solution of the differential equations is simplified
by taking the energy of the circuit as the basic time variable since
this is fixed by thinintial conditions
   /
4945
overtone quartz crystal units  the experimental crystal described
is a circular plate carrying an evaporated metal film held at diametrically
opposite points by springs attached to the lead terminals  details
are given of the lapping process and the frequency adjustment
   /
4946
the most elementary geometrical representation of loss free linear
quadripoles  it is possible to describe impedance transformations
in lossless and linear quadripoles by geometrical quantities and
by cascade parameters  an unambiguous geometrical representation
in the form of a system of two transformation lines equivalent to
the one transformation line of an impedance transformation is also
possible and this leads to a new and unified method of representing
the three different transformations by linear quadripoles and by
elliptical and hyperbolic quadripoles as well as by the parabolic
reactance quadripole  this gives for the linear quadripoles an intuitive
and elementary form of treatment which has proved to be very useful
for the solution of many quadripole problems  an impedance transformation
using the images with respect to two transformation lines is given
for the example of a parabolic reactance quadripole such as a series
capacity
   /
4947
interference spectra and aerial filters  a note on the problem of
the simultaneous operation of directional radio systems with pulse
modulation  the design of continuously tunable multi circuit diplexing
filters for communication systems is discussed  a frequency separation
of is assumed between the associated transmitter and receiver and
the asymmetrical nature of the transmitter spectrum is taken into
account
   /
4948
theory of synchronization of self oscillations of arbitrary form
analysis is given for an oscillation containing only a few harmonic
components  the effect of applying a sinusoidal force of a frequency
near the third harmonic is investigated by a method involving the
use of fourier series coefficients
   /
4949
discrimation of a synchronized oscillator against interfering tones
and noise  the discrimination exercised by a nonlinear regenerative
tuned circuit against unwanted signals accompanying a synchronizing
tone is due partly to the frequency response of the system and partly
to the nonlinearity provided that the synchronizing signal has a
greater amplitude than the unwanted signals after allowing for frequency
response  the phenomenon is analysed and measurements of discrimination
against noise are reported the degree of discrimination can be very
great when the synchronizing frequency is very close to the natural
frequency of the circuit  when the synchronizing tone is absent or
is not dominant there is no reduction of the interference intensity
or bandwidth
   /
4950
a wide range phase shift oscillator  an oscillator with a frequency
range from below to over is described coupling is used  a polyphase
version is also described
   /
4951
a grounded grid valve system with high stability characteristics
   /
4952
frequency stability of oscillators with large grid and anode capacitances
general analysis is given for the clapp circuit  various factors
affecting the frequency and the optimum distribution of instability
components among the circuit elements and supply voltages are discussed
   /
4953
the generation and application of rectangular pulses  a survey of
various known techniques covering both relaxation oscillators and
monostable circuits  a delay line pulse generator a free running
multivibrator and a cathode coupled monostable multivibrator are
discussed in detail  the suitability of a valve for switching applications
can be estimated on the basis of a figure of merit given by the
ratio between the mutual conductance and the total interelectrode
and stray capacitance  transition times are about for circuits using
high double triodes or pentodes and of the order of for circuits
with low valves
   /
4954
study of a flip flop with four positions of equilibrium by the methods
of topological analysis  analysis is presented in general terms for
a two stage circuit assuming square law valve characteristics  three
possible states identified are static dynamic and impulse  the eccles
jordan and multivibrator circuits are particular cases  an experimental
circuit has been designed its performance agreed well with the predictions
   /
4955
multivibrator circuits using junction transistors  conventional circuits
operating predictably at frequencies up to at least are described
   /
4956
reduction of the minimum striking voltage of hydrogen thyratrons
an auxiliary tripping circuit is described by means of which the
output voltage of a line type thyratron pulse generator is made continuously
variable from
   /
4957
a temperature stable transistor  an oscillator for telemetry purposes
is described
   /
4958
cascade amplifier  a cathode coupled phase inverter circuit using
cascode connected twin triodes is described as part of a high fidelity
amplifier which does not require a specially designed output transformer
   /
4959
analysis of a differential magnetic amplifier with flux reset control
   /
4960
the smoothing of non formulated experimental laws by an averaging
operation involving no spurious deviations  a section of an experimental
curve comprising points is assimilated to a second degree polynomial
and the required ordinates are hence calculated without introducing
spurious undulations
   /
4961
a simplified mathematical approach to hysteresis losses  the hysteresis
loop such as a normal curve is approximated by an ellipse features
resulting from harmonics being neglected calculations are thus simplified
   /
4962
the absorption spectrum of nitric oxide in the far ultraviolet
   /
4963
on asymptotic series fo functions occurring in the theory of diffraction
of waves by wedges  an asymptotic expansion of the integral expression
for diffraction by a wedge at distances large compared with is obtained
as the sum of a fresnel integral as leading term and an asymptotic
series of inverse powers of the distance for small values of the
distance the expansion takes the form of a series involving bessel
functions
   /
4964
multipotentials of multipoles  general theory is presented applicable
equally to magnetic or dielectric multipoles  every multipole is
shown to be associated with a scalar or vector multipotential which
has spherical symmetry from the equation of this multipotential the
usual scalar potential can be obtained by successive derivations
   /
4965
the electrostatic centre of a conductor
   /
4966
variation of volta potential with temperature  experimental results
show that the measured work functions of and depend on the experimental
conditions rather than on the electron concentration or structural
phase changes  this was investigated in greater detail by
   /
4967
investigation of the temperature dependence of the electron work
function of metals and semiconductors  the variation of the work
function of copper and nickel sheets was determined from the characteristics
of a special diode with a tungsten filament as a function of
time temperature and degree of vacuum  the temperature dependence
was also investigated for type and  results presented graphically
indicate that for work function measurements on metals a vacuum better
than is required
   /
4968
on the molecular theory of electrostriction  the case of a sphere
of fluid dielectric subjected to a uniform external field is discussed
from both macroscopic and microscopic points of view  that part of
the spur of the stress tensor which depends quadratically on the
applied field is calculated for both nonpolar and dipolar dielectrics
the lorenz lorentz and debye theories lead to the result that is
zero but more modern theories lead to a different result
   /
4969
millimeter wave absorption in superconducting aluminum  available
experimental evidence indicates that for wavelengths above the absorption
is different for the normal and the superconducting states  measurements
are reported on a high purity al waveguide the ratio of surface
resistivities for the superconducting and normal states is plotted
as a function of temperature for various values  the results are
discussed in relation to alternative energy gap models
   /
4970
very high frequency absorption in super conductors  measurements
indicate that the temperature at which the absorption departs from
that in the normal state differs from the transition temperature
by an amount strongly dependent on the frequency  a brief discussion
shows that this dependence follows immediately from the concept of
a gap in the electron energy level spectrum of a superconductor
   /
4971
glow to arc transition  conditions for the glow to arc transition
at moderately high pressures have been studied experimentally  over
this pressure range the transition is certain to occur only when
the field reaches a critical value this result is consistent with
a field emission mechanism for the transition
   /
4972
theory of the high frequency discharge in gases at low pressures
determination of starting conditions  continuation of work reported
previously  the importance of secondary emission from the walls is
emphasized  experimental and theoretical curves of starting voltage
as a function of pressure for frequencies of and are compared
   /
4973
method of determining the cathode fall in a glow discharge  a brief
account is given of a method involving the use of a hot cathode discharge
intive column surrounding the cold cathode in the other arm
   /
4974
experimental verification of the wave mechanical theory of field
electron emission  methods described br are used to calculate the
current density and field strength at a tungsten point and hence
to estimate the accuracy of results obtained previously  consideration
is extended to the case when the tungsten is coated with foreign
atoms
   /
4975
electron emission from cold metal surfaces at medium field strengths
report and discussion of measurements of the field emission of and
cathodes  gave the highest emission the lowest
   /
4976
dynamics of ionized media  the behavior of an ionized plasma is discussed
in an approximation in which an individual particle is assumed
to obey a fokker planck equation and where its interaction with the
environment is incorporated in the coefficients of the partial differential
equation
   /
4977
the study of ferromagnetism in the institute of physics at the university
of ferrara  a short report outlining some of the more important
results achieved  both thin film and massive specimens have been
studied  research on internal dissipation is being pursued
   /
4978
radiation emitted by a uniformly moving electron in electron plasma
in a magnetic field  results of the theoretical considerations presented
indicate that cerenkov type radiation may be produced by charged
particles not necessarily moving at relativistic speeds cosmic particles
in the ionosphere  the frequencies of the radiated ordinary waves
lie in the range where is the plasma angular frequency that of extraordinary
waves in the range where is the gyrofrequency  extraordinary
waves only are produced in weak magnetic fields and by relativistic
electrons
   /
4979
investigation of the propagation of signals in dispersive media using
an acoustic model  the theory of propagation of waves in a dispersive
medium as developed by sommerfeld and brillouin is experimentally
verified by measurements on an acoustic model which comprises a long
hollow tube with closely spaced helmholtz resonators along it
   /
4980
an approximate theory of the diffraction of an electromagnetic wave
by an aperture in a plane screen  theory based on the sommerfeld
half plane solution is developed  for certain regions the field can
be conceived as arising from the flow of electric and magnetic currents
along the edge of the half plane  this concept is extended to apertures
of arbitrary form the case of the circular aperture being studied
particularly the theory is supported by results of measurements
   /
4981
the magnetic screening effect of iron tubes  the problem is approached
by considering the induced pole strength on the surface of the iron
the distribution of pole strength in general produces a magnetic
field which varies from place to place over the screened region
observations support the calculated values of screening ratio
   /
4982
radio astronomy and the fringe of the atmosphere  a survey presenting
results of investigations on scintillations of radio stars in relation
to the atmosphere in the altitude region on meteor echoes and on
echoes from aurorae  the determination of the total electron content
in the earth moon space by the study of lunar echoes is discussed
   /
4983
cosmic radio frequency radiation near one megacycle  observations
were made of cosmic radiation at and during the period march october
at hobart tasmania  photographs of specimen records are reproduced
for values of the critical frequency near the observing frequency
there is strong correlation between critical frequency and received
amplitude for lower values of critical frequency the received amplitude
increases to an independent limiting value  the greatest intensity
of the radiation arriving from the zenith when the plane of the galaxy
was overhead was steradian at  only ordinary ionospheric propagation
was important in the observations recorded
   /
4984
observations of emission from the sun during the solar eclipse of
june at byurakan  results presented graphically of intensity measurements
during this partial eclipse show a decrease of up to  the diameter
of the sun and times the optical diameter at and respectively
   /
4985
on deriving geomagnetic dipole field coordinates from cosmic ray
observations  the coordinates of an equivalent dipole representing
the external geomagnetic field can be determined from measurements
of the nucleonic component longitude and latitude effects in the
region of the geomagnetic equator  the measurement method and the
relevant theory are outlined
   /
4986
note on the adjustment of isomagnetic charts to mutual consistency
   /
4987
variations in strength of wind system in the dynamo mechanism for
the magnetic diurnal variation deduced from solar flare effects at
huancayo peru
   /
4988
electrophotometric investigation of atmospheric ozone during the
solar eclipses of february and june
   /
4989
abnormal propagation
   /
4990
atmospheric temperatures and winds between  rocket experiments made
in new mexico between and september are described and the results
are analysed  the mean altitude distribution of temperature exhibits
a maximum of about at with a lapse rate of about above the peak
the highest wind speed was observed during winter its value was
   /
4991
arctic upper atmosphere pressure and density measurements with rockets
report of measurements made during and using rockets launched at
an altitude of about from balloons the greatest altitude reached
was about  results deviated in some cases from previous rocket measurements
   /
4992
electron distribution in the ionosphere  addendum to an earlier note
   /
4993
irregularity and regularity of the sporadic layer  from observations
at recording stations much information is obtained about the highest
vertical incidence reflection frequency but less about the blanketing
frequency  results must be interpreted in statistical terms  time
and distance correlation functions are established  diurnal seasonal
and geographic regularities are discussed  a sharp maximum in occurs
at the magnetic equator  no well defined influence of the solar cycle
has been found and only a very weak lunar tide effect  observations
of the variation of reflection coefficient with frequency have been
made apart from the routine evaluations  in temperate latitudes in
about a third of all cases there is no partial reflection in other
cases local variations of electron concentration are such that the
peak value mean value ratio is between and higher ratios are rare
at low latitudes the variation may be more important  ionograms of
different stations have been classified for transparency scatter
angle of incidence and layer development  diffuse echoes exist often
near the magnetic equator  in most cases ionization originated as
a thin layer of constant altitude  transitory downward movements
are responsible for in daytime  a cumulo cirrus cloud layer is a
good model for ionization  possible ionization processes are discussed
   /
4994
temperature distribution of the ionosphere under control of thermal
conductivity  bates theory is extended  the energy absorbed in the
region is assumed to be conducted downward into a denser region where
it is dissipated by infrared emission  calculations indicate that
the atmosphere is isothermal above about and that there is a very
strong temperature gradient between and  the temperature in the isothermal
region must be assumed to be to meet the requirement for the
atmosphere near to support an region  the low temperature at is due
primarily to the lack of absorbed energy there rather than to the
presence of a strongly emitting layer
   /
4995
a new method for obtaining electron density profiles from records
a practical and accurate method for reducing records to electron
densities true height is described and used to analyse records taken
at white sands  direct measurements of electron densities in the
ionosphere obtained with the aid of rockets are used to check the
methos obtained by these two independent techniques are shown to
be in excellent agreement  twenty records were reduced for the period
from all of which reveal a considerable degree of regularity in the
height of the daytime and regions  some of the profiles obtained
are shown  one of the illustrations shows a one hour sequence where
the virtual height varied from whereas the true height remained essentially
unchanged
   /
4996
airborne ionospheric measurements the north po le area  a brief preliminary
report
   /
4997
ionospheric observations at banaras during the total solar eclipse
on june
   /
4998
polarization of the echoes from the ionosphere  details are given
of an improved type of radio polarimeter similar in principle to
that evolved by eckersley and farmer for operation in conjunction
with high resolution sounding equipment  with this arrangement it
is possible to separate normal echoes from those received from thin
layers or cloud type irregularities  photographs of some observed
polarization patterns are reproduced and briefly discussed
   /
4999
the fading of radio waves of frequencies between
   /
5000
the fading periods of the region coupling echo
   /
5001
the determination of the horizontal velocity o ionospheric movements
from fading records from spaced receivers  a method is presented
which does not require a long sample of record and which is valid
for any distribution of orientation of lines of maximum amplitude
the derived formula is compared with that of mitra
   /
5002
a determination of ionospheric winds for a hour period  results are
given of an analysis using the method proposed by court of the fading
records obtained at spaced receivers during an arbitrarily chosen
period  a diurnal variation of wind direction appears to be indicated
   /
5003
on the deviations of the course of elements of atmospheric electricity
on continents from the worldwide course  extensive recordings show
that continental deviations from the normal oceanic diurnal pattern
potential gradient air earth current variations are caused mainly
by positive space charges produced by urbanization industry and
traffic and distributed by air movements
   /
5004
relationships between aurora and sporadic echoes at barrow alaska
report of observations of visual aurora made simultaneously with
ionospheric soundings during the observations for three nights are
described in detail  analysis of the results shows that echoes at
frequencies tend to occur when the aurora is near the zenith that
there is a direct relation between the brightness of inactive aurorae
and the top frequency of echoes and that echo ranges correspond with
estimated slant ranges of visible auroral forms
   /
5005
the annual variations of the atmospherics existence and explanation
of a second maximum in winter if only strong impulses are counted
records obtained at munich of the numbers of atmospherics received
in frequency ranges and over a period of five years are analysed
and evaluated from the meteorological point of view
   /
5006
nirrc spectrograms of a type of whistler observed at college alaska
made by analysing tape recording the nose whistler a new high latitude
phenomenons are reproduced and discussed  the initial or nose frequency
depends primarily on gyrofrequency hence such observations should
enable the effects of gyrofrequency and plasma frequency on dispersion
to be separated thus leading to more reliable estimates of the ionization
density in the outer ionosphere
   /
5007
the interpretation of pulse trains associated with lightning flashes
a treatment of the propagation of atmospherics by earth and ionosphere
reflections assuming a radiation dipole source
   /
5008
proceedings of fourth meeting of the mixed commission on the ionosphere
publishers union radio scientifique internationale brussels  contains
papers presented in brussels in and discussions on them
   /
5009
the electron voltaic effect in germanium and silicon junctions
   /
5010
the effect of radioactive radiation on a photocell
   /
5011
automatic control of power equipment for telecommunications and other
essential services  two types of no break generating sets are described
an all electric battery operated equipment and a diesel electric
equipment  detailed descriptions are given of three electronic devices
used with these sets a static exciter automatic voltage regulator
making use of two saturated transductors an alternator synchronizer
in which the generator and mains voltages are compared in a triode
circuit speed regulator using a thyratron which feeds the control
field of the motor and also incorporates alarm and protection devices
   /
5012
servomechanism analysis  gives the mathematical background for the
analysis and design of servomechanisms including a clear introduction
to the theory of laplace transformations
   /
5013
stanford seattle whistler observations  observations of times of
occurrence of whistlers were made at seattle washington and stanford
california for two hours every week from to in order to determine
the percentage of shistlers received simultaneously at both locations
the figure obtained was about  this result is examined in relation
to theories of whistler origin and propagation it gives support to
theory
   /
5014
a new serial digital decoder  intermediate storage and an amplifier
feedback loop are used making the decoder practically independent
of clock timing pulses  it can also be used in an analogue system
to solve certain types of polynomial equation
   /
5015
interconnection of electronic computers  brief account of experiments
on the joint operation of the and machines on business data processing
work the former machine transmits control signals to the latter via
a cable
   /
5016
design and construction of small automatic computers with programming
arrangement at the higher technical school in dresden  illustrated
description of a computer which includes about valves and measures
the control desk is separate  a magnetic drum store is used
   /
5017
principles and application of electronic analogue computers  typical
examples of electrical analogues and the equipment for producing
them are discussed and general design considerations are presented
the saunders roe general purpose analogue computer is described
   /
5018
new electronic analogue apparatus of the institute of automatics
and telemechanics of the academy of sciences  an illustrated description
including block and circuit diagrams of the comprising a unit for
solving linear differential equations of up to the sixth order a
unit for solving nonlinear differential equations and a power supply
unit as well as additional special purpose units
   /
5019
design of a timing device and nonlinear units for an electronic differential
analyser
   /
5020
basic circuits used in digital automation  commonly used circuits
are described from a practical point of view with circuit diagrams
and details of components
   /
5021
an economical relay operated accumulator  design details are given
of a binary adder with a maximum capacity of about
   /
5022
the hyperbolic field tube an electron beam tube for multiplication
in analogue computers
   /
5023
impedance and admittance surfaces  three dimensional locus diagrams
are used to investigate the variation of impedance and phase displacement
in two pole circuits in response to variations of frequency resistance
inductance or capacitance  the impedance and admittance surfaces
include straight lines corresponding to the important special case
of zero phase displacement when the impedance is independent of the
damping or detuning
   /
5024
bridge and short arc erosion of copper silver and palladium contacts
on break
   /
5025
transformer design for zero impedance amplifiers  lamination weight
reductions of up to may be obtained without increased distortion
in a transformer designed for an zero impedance output stage  design
formulae are given
   /
5026
the stabilidyne  a method for applying the harmonics of a quartz
crystal oscillator to control the frequency of a receiver or transmitter
is described  for reception the signal frequency and a suitable harmonic
of the crystal oscillator are separately mixed with oscillations
from a common local oscillator and the two products are then mixed
to obtain a frequency which is the difference between that of the
signal and the crystal harmonic  stability of the order of with a
signal frequency of is readily obtained  the characteristics of several
industrial equipments are described
   /
5027
a phase shift circuit for a wide frequency range  a and a network
are combined in such a way that the undesired phase changes at the
outputs of the individual networks due to a frequency change cancel
one another in the combined output
   /
5028
calculations for ferroxcube pot cored coils  a method of calculating
core dimensions and windings is presented giving results accurate
to within
   /
5029
ferroresonant computing circuits  the basic ferroresonant circuit
and applications to switching and counting devices are described
   /
5030
the equilibrium states of a bistable flip flop from the point of
view of reliable and stable operation  the influence of individual
components on the functioning of the eccles jordan circuit is discussed
and permissible tolerances for given performance are determined
   /
5031
influence of an alternating voltage and a direct voltage on a nonlinear
capacitor  families of curves are presented showing measured variations
of capacitance and tan as functions of a direct voltage and a voltage
applied simultaneously for a capacitor with dielectric  the curves
facilitate determination of optimum working point for dielectric amplifiers
   /
5032
linear systems  the method of analysis presented previously is developed
the treatment is applicable to all linear passive resonator systems
whether damped or undamped
   /
5033
possibility of free oscillations in a variable parameter resonant
system  comprehensive general analysis is presented for time variable
linear systems
   /
5034
papers presented at the conference on piezoelectricity
   /
5035
the equivalent network of a piezoelectric crystal with divided electrodes
a general equivalent circuit is worked out for the crystal treated
as a quadripole for frequencies close to that of mechanical resonance
   /
5036
spherical frustum cavities  symmetrical spherical frustum cavities
are studied as intermediate cases between the sphere and the cylinder
resonance wavelengths and factors are determined by abeles method
a wavemeter using a hemispherical cavity partly filled with is proposed
curves are presented showing the variation of with cavity size for
and
   /
5037
theory of coupled endovibrators  continuation of work noted previously
a mathematical analysis is given of the propagation of waves in a
chain of cavity resonators coupled by long narrow slots
   /
5038
electromagnet oscillations in a parabolic tube as a particular case
of the interactions of tow cavities through a throat  free oscillations
in a tube of parabolic profile and rectangular cross section are
considered  the tube is regarded as consisting of two cavities interacting
through the throat  the wave equation is derived and solutions
are found for the cases where the two cavities are identical and
not identical  experimental results are in good agreement with the
theoretical conclusions
   /
5039
calculation of the natural frequency of a type cavity partly filled
with an absorbing dielectric  the system considered comprises a re
entrant cylindrical cavity resonator with a solid dielectric specimen
in the form of a truncated cone placed between the base of the cylinder
and the butt end of the inner conductor  formulae derived for the
natural frequency and the damping can be used also to determine the
components of the complex dielectric constant of the specimen this
analysis also provides the theoretical basis of the measurement method
described by works and others
   /
5040
ferrites in resonant cavities  a formula is derived for the frequency
shift produced by introducing a sphere of ferrite into a resonant
cavity
   /
5041
parallel network  a simplified design method is presented based on
finding an equivalent network which is more amenable to mathematical
treatment
   /
5042
a note on bandwidth  the concept of bandwidth is examined in relation
to networks such as integrators which are not designed to provide
faithful transmission of a waveform  the bandwidth of such a network
is defined as the maximum bandwidth of the input signal for which
the output does nt differ from that of an ideal network by more than
a prescribed amount
   /
5043
resistance capacitance filter networks with single component frequency
control
   /
5044
a practical method of designing active filters  a method for designing
filters for the frequency range below about with sharp cut off is
based on consideration of five basic variables namely two resistances
tow capacitances and the gain from these further practical parameters
are derived by taking the products of resistance and capacitance
the ratio of resistances and the ratio of capacitances  the active
elements can in many cases be simple cathode follower circuits  design
data for a number of different cases are tabulated
   /
5045
the design of low frequency high pass filters  the design of a twin
network incorporated in a feedback amplifier circuit is discussed
and details are given relating frequency response to phase shift
in the amplifier  the use of compensating sections for securing a
flat pass band characteristic is considered and a practical example
is worked out
   /
5046
new rejector circuit bifilar trap  comments on of
   /
5047
theory of noisy four poles  english version of paper originally published
in
   /
5048
nonlinear coupled systems  analysis applicable to valve oscillator
circuits generally is presented  different types of oscillator are
distinguished topologically
   /
5049
amplitude limitation in oscillators  an oscillator which includes
two biased diodes in the grid circuit to limit oscillation amplitude
is analysed  amplitude of oscillation and harmonic distortion are
calculated and represented by curves  from these curves it is observed
that oscillations can be modulated linearly no frequency modulation
occurs during amplitude modulation and harmonic distortion is very
low  also the circuit is found to be adequate for high frequency
stability  the distinctive feature of the circuit is shown to be
that the static conditions of the valve such as bias voltage and
direct anode current are independent of the oscillation amplitude
a practical circuit is described
   /
5050
developments in sound reproduction
   /
5051
docile behaviour of feedback amplifiers  a docile amplifier is one
that remains stable when connected to any passive network of a specified
class  a simplified geometrical approach is used to derive the docility
criteria for passive end loading ideal transformer feedback bilateral
passive feedback and arbitrary passive feedback
   /
5052
notes on the design of distributed amplifiers  the treatment used
takes account of the self capacitance of the coils and the effect
of using anode and grid lines with different propagation speeds the
latter effect can be useful in avoiding the large increase in gain
of the derived filter type amplifier at the upper end of the band
   /
5053
differential amplifiers with asymmetrical output  the basic circuit
discussed comprises a pair of similar triodes with equal resistances
in anode and cathode leads when equal phase voltages are applied
to the two grids voltages in phase opposition are produced at the
cathode of one valve and the anode of the other the output is taken
from the mid point of the circuit connecting these two points  theory
of operation is presented and two experimental models are described
   /
5054
design of push pull magnetic power amplifiers  the method is described
in detail and is illustrated by discussion of a amplifier with a
power amplification of and internal feedback
   /
5055
principles of construction of magnetic amplifiers with a low sensitivity
threshold
   /
5056
high frequency operation of magnetic amplifiers  digest of paper
published in  operation at high frequency makes possible power gains
and bandwidths unattainable at power frequencies since a given power
can be controlled with a smaller core
   /
5057
junction transistors at high frequencies  methods of stabilizing
transistor amplifiers are discussed and formulae are presented for
calculating the characteristics of a linear amplifier at any frequency
and for determining the principal parameters of junction transistors
with common emitter common base or common collector connections
curves are given of maximum gain as a function of frequency
   /
5058
the successive derivation of experimental laws  refinement of the
method of smoothing experimental curves described previously
   /
5059
on the use of gram charlier series ot represent noise  the stochastic
time series produced by the random occurrence of identical events
is considered  if the waveforms corresponding to the individual events
and to the resulting autocorrelation function and power spectrum
are each represented by a gram charlier series relatively simple
relations exist between the different sequences of coefficients
if the noise bandwidth is not too great the number of terms in the
series is small enough to permit computation  the formulae are applied
to the analysis of experimental data for noise associated with reverse
current in a si diode
   /
5060
on the theory of the acousto electric effect  when an acoustic wave
passes through an insulated solid it gives rise to an electric field
in the direction of propagation  the influence on this phenomenon
of thermal lattice vibrations at temperatures above the debye temperature
is investigated theoretically  the calculations indicate that
the field is proportional to both the intensity and frequency of
the acoustic wave  the effect is so small that it would not generally
be observable in cu but is larger by several orders of magnitude
in ge
   /
5061
symposium on luminescence  brief summaries are given of about papers
read at the symposium held at minsk
   /
5062
birefringence resulting from the application of an intense beam of
light to an isotropic medium
   /
5063
a new model of classical electron
   /
5064
electron physics tables  eight parameters are tabulated relating
to the energy and motion of electrons accelerated by a potential
difference
   /
5065
magnetic moment of the electron  a survey of experimental and theoretical
work indicating evidence of anomalies
   /
5066
electrostatic charges in plastics  experimental evidence is presented
that the static charge on plastics is a volume charge distribution
rather than a surface distribution  the charge contained in a plastic
that has been in contact with metal is found to drain out of the
plastic by a flow process which depends both upon the resistivity
of the plastic and upon the possibility of neutralization of surface
charges by opposite charges external to the plastic such as in air
   /
5067
field dependence of magnetoconductivity  a theoretical calculation
is made of the dependence of the elements of the conductivity tensor
on the magnetic field for the case of a crystal with arbitrary energy
band structure  the results are the same as would be given by a superposition
of electron gases whose cyclotron frequencies are related
harmonically  the strengths of the harmonics depend on the band structure
the diagonal of the conductivity tensor are monotonically decreasing
functions of the magnetic field strength
   /
5068
the characteristics of a discharge at a probe at a positive potential
and the measurement of the associated gas density
   /
5069
t t  n the floating probe method for the measurement of ionized gas
revised expressions are obtained for the positive ion current and
electron temperature for the usual double probe method  a triple
probe method is proposed for measurement of energy distribution in
electrodeless or discharges and the applicability of the techniques
is discussed
   /
5070
formulae for the mean losses of energy in collisions of slow electrons
moving in diatomic gases  approximate formulae are derived which
correspond closely with results of experiments for electrons of low
energy  the formulae are relevant to the theory of interaction of
radio waves
   /
5071
two electrode high frequency discharge at pressures from to atmospheric
an experimental investigation is reported of discharges in nitrogen
and argon at frequencies of to and  variation of running voltage
with electrode separation and variation of electric field with pressure
are shown graphically and photographs of discharges are reproduced
   /
5072
theoretical interpretation of field emission experiments  experimental
results obtained by various workers on field emission from tungsten
and barium on tungsten surfaces are discussed in relation to theories
regarding the nature of the surface potential barrier and the distortion
of the field by space charge
   /
5073
kinetic theory of the lorentz gas case of maxwellian molecules  discussion
of differences between the views and results of the author and
those of
   /
5074
use of the boltzmann equation for the study of ionized gases of low
density  the behaviour of the gas in a strong magnetic field is discussed
   /
5075
on the dipole resonant mode of an ionized gas column  calculations
show that the multiple resonances found by were created by the discontinuities
in their approximation to the gaussian function and that
the actual gaussian distribution exhibits only one resonance
   /
5076
fundamental equations of a classical non conservative electromagnetism
   /
5077
the computation of coils for producing uniform magnetic fields and
constant field gradients  calculations for helmholtz coil systems
are presented  for the field at the mid point on the axis to be uniform
the second derivative of the field in the axial direction must be
zero at that point for the field gradient to be constant the third
derivative must vanish  families of curves suitable for design purposes
are derived
   /
5078
incidence of electromagnetic waves on double infinite grids  the
system considered comprises a double grid of parallel metal rods
the grids are spaced apart and the rods in each grid are spaced apart
the rods in one grid being staggered by an amount relative to the
rods in the other grid the radius of the rods is  calculations are
made of the reflection coefficient and the refractive index corresponding
to three values of for and for normal incidence with
   /
5079
a method for integrating maxwells equations  maxwells equations for
propagation of waves are integrated for the case where the functions
representing the wave contours are separable  applications are discussed
showing the relation between the theory and geometrical optics
   /
5080
variational method for the calculation of the distribution of energy
reflected from a periodic surface
   /
5081
experimental study of the diffraction of microwaves by rotationally
symmetrical apertures  measurements at have been made using circular
and annular apertures  the results indicate that diffraction calculations
based on kirchhoffs approximation are accurate to within at planes
as close as twice the diameter of the aperture the accuracy improving
as the distance increases
   /
5082
rigorous solution of a particular diffraction phenomenon  diffraction
of a plane wave by a perfectly conducting infinitely thin screen
is analysed using an infinite system of algebraic equations and an
infinite number of unknowns for th case of the electric vector parallel
to the screen edges  the procedure is to calculate the vector potential
for the surface assuming a sinusoidal distribution of parallel straight
line currents  extension of the method to the more general case of
arbitrary direction of electric vector would be feasible using electronic
computers
   /
5083
structure of a magnetohydrodynamic shock wave in a plasma of infinite
conductivity  the analysis presented is relevant ot problems of solar
radiation the ionosphere and cosmic rays
   /
5084
growing electric space charge waves  theory presented previously
purporting to explain the operation of the electron wave valve and
the origin of solar emission is shown to be unsound alternative theory
is given
   /
5085
some measurements on the spectral line shape and width of a paramagnetic
resonance absorption line  measurements on hydrazyl at a frequency
of about are reported
   /
5086
the motion of charged particles in weakly variable magnetic fields
analysis is simplified by considering in place of the actual particle
which follows a helical path an equivalent particle following a mean
path and having a magnetic moment
   /
5087
interaction of excitons with lattice vibrations in polar crystals
   /
5088
early history of radio astronomy
   /
5089
cosmic radio sources observed at  a survey has been made over most
of the celestial sphere between declinations and using a narrow pencil
beam  discrete sources giving flux densities of about were identified
including which may not have been previously reported  nearly all
the discrete sources are associated with irregularities of the background
radiation
   /
5090
radio emission from novae and supernovae  attempts have been made
to observe the radio emission at from two supernovae and ten novae
keplers star was the only reasonably certain identification  a comparison
with radio observations of other supernova remnants suggests a
constant ratio between the present radio emission and the maximum
emission of light  it is concluded that for common novae which are
not detectable as radio sources this ratio must be smaller than for
supernovae  the galactic radio emission near the plane of the milky
way could be largely the integrated emission of supernova remnants
but common novae could not contribute appreciably
   /
5091
the masses of the magellanic clouds from radio observations
   /
5092
radiation from jupiter  an examination of records at sydney shows
that bursts at observed in and previously ascribed to a terrestrial
cause were in fact due to radiation from jupiter this confirms the
observations of  some new observations are also mentioned  the usefulness
of jupiter radiation for studying propagation conditions near
the sun is pointed out
   /
5093
observation of an eclipse of the crab nebula  report of observations
at frequencies of and during the occultation of the crab nebula by
the moon on  the radio source corresponds closely to the visible
structure of the nebula it is deduced from this result that the electron
density in the lunar atmosphere is
   /
5094
the daily variation of the cosmic ray intensity measured near the
sunspot minimum
   /
5095
a note on the interpretation of transient echoes from the ionosphere
comment on a note by  recent radio echo work on meteors shows that
a midday maximum is often observed in the rate of occurrence of meteors
observations with narrow beam aerials on show that a tendency during
the months for the main peak to occur at is completely reversed from
to when the major peak occurs during the daytime
   /
5096
the suns general magnetic field
   /
5097
the solar outburst  observations by the royal greenwich observatory
cosmic ray photographic and magnetic observations are presented records
of the intensity of atmospherics on a frequency of show a very substantial
decrease in received signal level at which appears to be attributable
to the cosmic ray increase associated with the flare
   /
5098
a long wave anomaly associated with the arrival of cosmic ray particles
of solar origin on  records of atmospherics received on a frequency
of at the royal observatory show a sudden decrease coinciding with
the time of arrival of solar cosmic ray particles in the dark hemisphere
of the earth
   /
5099
some unusual radio observations made on  records of sky wave signals
obtained at on frequencies showed very strong absorption during the
occurrence of the solar flare of this date on the main effect was
a decrease of in the reflection height  on frequencies at upsala
almost complete absorption occurred from sunrise until the late afternoon
   /
5100
symposium on the earth satellite program vanguard of outer space
the text is given of seven papers presented at a symposium held in
dealing with various aspects of the plans for launching earth satellites
during the international geophysical year
   /
5101
the crust as the possible seat of earths magnetism  magnetic material
in the earths crust to a depth of will be highly permeable as a result
of temperature and pressure conditions  interaction between solar
corpuscular streams and a very weak initial magnetic field in the
crust will magnetize it to saturation the estimated magnetic moment
of the shell agrees with the observed magnetic moment of the earth
   /
5102
long period variations in geomagnetic activity  analysis of data
shows that correlation between the sunspot number and the magnetic
figure is markedly improved by taking means for the year sunspot
number cycle and for the year sunspot magnetism cycle in place of
annual means
   /
5103
theory of the rocket grenade method of determining upper atmospheric
properties by sound propagation  theory applicable to projected experiments
is developed from earlier work a knowledge of the composition
of the atmosphere and of the velocity of the sound of the explosions
is assumed
   /
5104
electron distribution in the ionosphere  analysis of records by the
method described earlier suggests that the ionosphere consists of
three chapman layers and and that the temperature is uniform
   /
5105
effective tilts of the ionosphere at places about  fuller account
of work described previously
   /
5106
the rates of production and loss of electrons in the region of the
ionosphere  from the results of the rates of production and loss
of electrons in the region are deduced  bradburys theory of the formation
of the layers is shown to be self consistent it gives a scale
height of for the ionizable constituent of the atmosphere between
and  this result agrees better with the atmospheric model deduced
by bates from rocket experiments than with the model deduced from
experiments made on the ground  limits are established for the movements
caused by electron diffusion under gravity
   /
5107
the formation of the ionospheric layers and  it is shown that an
electron loss coefficient varying with height in the manner suggested
previously would explain the known facts about the splitting of the
layer and might also be a factor in determining the height of the
peak of electron density in the layer
   /
5108
the distribution of electrons in the undisturbed layer of the ionosphere
the variation of electron density with height is deduced from
records obtained at watheroo huancayo and slough and the form of
the typical layer for magnetically quiet days is described in a series
of curves detailed tabulated results are available at the cavendish
laboratory
   /
5109
processes controlling ionization distribution in the region of the
ionosphere  rocket measurements at heights approaching suggest that
the atmospheric density in the region may be some times less than
previously deduced from radio experiments  if the new value were
correct diffusion of ionization under the forces of gravity and of
its own pressure gradient would be likely to affect the shape and
height of the region notably  an investigation was made of the possible
effects of diffusion processes at such levels  the results indicate
that a region with arbitrary height distribution of ionization will
by diffusion assume the form of a chapman region after a time which
for levels is a few hours if the radio determinations of density
are correct but only a few minutes if the rocket determinations are
correct  it is suggested that there must be a systematic error in
the rocket observations
   /
5110
observations and analysis of ionospheric drift  spaced receiver fading
observations made at puerto rico during on and indicate average drift
speeds of and respectively  the data are thought to apply to the
layer and the data to the layer  owing to random changes the method
of similar fades is less reliable than the correlation method of
evaluation
   /
5111
automatic recording of ionospheric characteristics  following the
proposals of nakata a device is proposed which gives a direct record
of
   /
5112
ionospheric recorders and sporadic  brief report of tests made at
brisbane disproving the statement which has been made by various
workers that the observed frequency characteristics of the region
vary rapidly with the overall sensitivity of the recording equipment
   /
5113
spread layer echoes and radio star scintillation  correlation is
noted between observations of radio star scintillations at one station
in equatorial africa and of spread layers at another distant  disturbed
magnetic conditions in winter cause decreased layer spread
   /
5114
ionospheric observations during the solar eclipse of  observations
made at haringhata miles of calcutta are reported  the recorder used
provided a frequency sweep from to in  the observed variation of
shows that the disappearance and reappearance of the ionizing radiation
source for the layer was not symmetrical with respect to the time
of the eclipse maximum  the ionization of the layer also showed a
marked drop during the eclipse  an observed drop in the ionization
of the layer may or may not have been an eclipse effect
   /
5115
lunar variations in the ionosphere  the global pattern of the observed
lunar variations of the height and electron density of the region
is summarized new analyses being presented for canberra brisbane
and washington  the height variation has an amplitude of maximum
height occurs at lunar hours at moderate latitudes and at lunar hours
at the geomagnetic equator  the variation of has an amplitude of
the maximum occurs at about lunar hours at moderate geomagnetic latitudes
and at lunar hours near the geomagnetic equator  theory is developed
on the basis of a current system at a height of about  the tidal
winds needed to drive the current the potential distribution in the
dynamo layer and the resulting periodic vertical drifts of ionization
in the higher layers are calculated  the lunar variations in are
calculated taking into account probable height variations of recombination
coefficient and ionization production rate the results are in
good agreement with observations  it is concluded that the amplitude
of the lunar tidal wind near the layer is about times greater than
that on the ground
   /
5116
influence of variable flow of positive solar particles on the wind
in the ionosphere  qualitative results of a calculation of the interaction
of electrodynamic and hydrodynamic forces in the ionosphere at
a height where the two forces are of the same order of magnitude
indicate a distribution of wind velocity and direction similar to
that observed by hoffmeister and shown in  shows the variation of
the and components and of the resultant of the wind velocity over
a day period
   /
5117
oblique transmission by the meteoric layer
   /
5118
the nature and detectability of clouds and precipitation as determined
by radar
   /
5119
measurement of atmospheric absorption on using solar radiation  measurements
were made at various times of day using a radiotelescope described
previously  only a part of the attenuation observed during sunset
can be attributed to absorption by oxygen and water vapour the remainder
about is so far unexplained
   /
5120
the height of emission of the line of the air glow as observed on
the jungfraujoch  a mean altitude of is deduced
   /
5121
a theory of scattering by nonisotropic irregularities with application
to radar reflections from the aurora  the existence and aspect sensitivity
of auroral echoes can be explained as back scatter from nonisotropic
columns of ionization parallel to the earths magnetic field of length
about and diameter caused by turbulence in an region having a maximum
electron density about times the normal value but the theory fails
to explain the rapid fading rates associated with auroral echoes
   /
5122
low frequency atmospheric noise levels in southern and central africa
detailed report of measurements made to determine the interfering
effect of atmospherics on radio navigation aids  results are presented
graphically and discussed with reference to local thunder conditions
   /
5123
meteors  the text is given of the papers presented at the symposium
reported previously
   /
5124
the design and operation of transistor converters  circuits are discussed
in which a junction transistor is made to oscillate and thus to
chop the current from a battery the chopped current is fed to a transformer
or ringing choke and the stepped up voltage output is rectified
and smoothed  design procedures are described in detail  see also
of
   /
5125
germanium and silicon power rectifiers  the development of junction
power rectifiers is reviewed and the special features of a unit rated
up to are described  for a shortened version see
   /
5126
germanium power rectifiers  the production and characteristics of
junction rectifiers capable of handling current densities of the
order of at an ambient temperature of are described and compared
with those of other rectifiers  some suitable circuits are indicated
   /
5127
an voltage stabilizer  a temperature limited diode placed in one
arm of a resistance bridge controls the output voltage through a
saturable reactor and autotransformer
   /
5128
wafer cells  the burgess dry battery is described and discharge characteristics
are given  the cells are of sandwich construction hermetically
sealed and the construction affords substantial savings in size and
weight as compared with earlier types of dry battery
   /
5129
the logical design of an idealized general purpose computer  a detailed
discussion emphasizing the distinction between the logic requirements
and the particular physical form of a digital computer
   /
5130
analog computers for the engineer  a rewiew of computer techniques
with tabulated data for some commercially available types
   /
5131
electronic methods of analogue multiplication  a general survey of
the principles used different systems are compared as to accuracy
speed and complexity
   /
5132
high speed electronic analogue computing techniques
   /
5133
an analog computer for the solution of tangents  a modified wheatstone
bridge arrangement is described permitting computation of the tangents
of angles between and  only linear elements are used  the accuracy
achieved is within part in  the design of plug in units is discussed
   /
5134
design of diode function simulators
   /
5135
digital computer techniques  brief report of a convention held at
the institution of electrical engineers london in  papers were presented
the full text together with reports of the discussion is to be published
in three sections as a supplement to
   /
5136
a variable multiple pulse stream generator  apparatus designed for
checking the logic of electronic computer circuits which require
numerous pulse streams for their operation is described  the electrostatic
pickup described previously of is used
   /
5137
analog computer for the differential equation  a high precision electromechanical
system developed from that mentioned previously uses a
torsion pendulum whose motion corresponds to the given expression
the solutions are obtained from photographic records of the motion
   /
5138
binary adder uses gas discharge triode
   /
5139
pulse circuits fabricate computer code disk  frequency divider counter
gate and wave shaping circuits control optical circle dividing machine
to produce bit pattern on photosensitive glass disk  used for analog
to digital conversion the code disk has a pattern accuracy of inch
and can be made in about hours  for another account see
   /
5140
an introduction to electronic analogue computers
   /
5141
an experimental investigation of subharmonic oscillations in a nonlinear
system  forced subharmonic oscillations in a circuit containing an
iron core are studied  damping is reduced by means of feedback so
that measurements can be effected at very low driving voltages and
subharmonics up to the ninth  results are in good agreement with
theory developed by lundquist for low driving voltages
   /
5142
frequency conversion with positive nonlinear resistors  positive
nonlinear resistors are defined as two terminal devices through which
the current is a real finite single valued nondecreasing function
of the voltage across the terminals with the added condition that
when subjected to an almost periodic voltage such a resistor will
absorb power at some frequencies and supply power at other frequencies
analysis indicates that modulation efficiency cannot exceed unity
that subharmonics are not produced and that the efficiency of generating
an harmonic cannot exceed
   /
5143
winding focus coils with aluminium foil  coils of al foil with a
thin coating of al oxide are wound with no additional insulation
   /
5144
polychloronaphthale impregnated paper capacitors  polychloronaphthale
waxes are particularly suitable for use as impregnants in paper dielectric
capacitors having stable characteristics at temperatures as high
as or over  in certain cases an aging effect is avoided by allowing
the wax to cool from the liquid to the solid state under the influence
of an or field  this phenomenon is discussed in relation to the dipole
nature of the waxes
   /
5145
industrial measurement of the temperature coefficient of ceramic
dielectric capacitors
   /
5146
tantalum solid electrolytic capacitors  a capacitor with low volume
capacitance ratio is obtain ed by forming a layer of on a porous
ta anode and then depositing a number of coatings of to form a solid
electrolyte  the unit is further coated with graphite and a layer
of alloy is sprayed on to form the cathode  temperature frequency
and life characteristics are reported
   /
5147
inter reciprocity applied to electrical networks  a new concept inter
reciprocity is introduced which is useful in the study of nonreciprocal
networks  when a particular topological operation termed transposition
is performed on a given linear network the initial network and the
resulting transposed network are said to be inter reciprocal  application
of the theory to a variety of general and special circuit problems
is illustrated the noise properties of gyrator triode and transistor
networks are discussed
   /
5148
the effect upon pulse response of delay  ariation at low and middle
frequencies  calculations are given for the magnitude and form of
the distortion introduced into a square wave by a network or system
which exhibits uniform transmission except for increasing phase delay
in the low mid frequency region  the fractional peak distortion is
found to be equal to twice the area under the curve relating to frequency
where is the delay relative to that at high frequencies  the waveform
of the distortion is given for several simple shapes of curve for
this distortion is especially characteristic of vestigial sideband
systems and occurs in television as a pre shoot before a transition
and as a smear after it
   /
5149
feedback theory further properties of signal flow graphs  continuation
of theory presented previously
   /
5150
transient behavior in a ferroresonant circuit  an analysis is made
of the response to a sinusoidal voltage of a circuit including a
nonlinear inductor  for certain frequency values of the applied voltage
there are three possible values for for the flux in the inductor
of which the middle value is unstable  the differential equation
representing the circuit has been solved using an analogue computer
for the case when the system is released in the region of the lower
stable state the solution corresponds to two sinusoidal oscillations
of different amplitude and frequency  if the system is released in
the region of the upper stable state the solution corresponds to
an oscillation modulated in amplitude and phase for certain values
of the parameters
   /
5151
measurement of the factor of cavity resonators using a straight test
line
   /
5152
some general properties of nonlinear elements general energy relations
an analysis is made of power relations in networks with reactive
nonlinear elements  two equations are derived relating the powers
at different frequencies the only assumption introduced is that the
nonlinear characteristic is single valued  the theory is relevant
to the operation of modulators demodulators and harmonic generators
   /
5153
tables of phase of a semi infinite unit attenuation slope  the five
figure tables published previously are to appear together with newly
prepared seven figure tables as
   /
5154
fundamentals in the synthesis of loss free quadripoles from lines
with continuous non uniformities  the synthesis is facilitated by
appropriate choice of line coordinates and a polynomial representation
of the characteristic impendance  application to problems of wide
band transformation and matching are illustrated
   /
5155
impedance quadripoles for the frequency compensation of aerial input
impedance  networks with one or two frequency independent resistances
are discussed which are capable of effecting wide band matching with
lower losses than reactive circuits at frequencies up to or above
composite coaxial line sections are used in an application to a dipole
aerial for use with a parabolic cylinder reflector he compensating
coaxial line serves as support for the dipole
   /
5156
normalized representation of transients in filter amplifiers with
double elements  the response of amplifiers with frequency dependent
negative feedback is analysed for various pulse and step waveforms
the frequency spectrum corresponding to a train of square pulses
is determined
   /
5157
a solution to the approximation problem for low pass filters  a method
of synthesizing filters is described in which elliptic functions
are used to effect a transformation in the complex frequency plane
which results in a symmetrical arrangement of the zeros and poles
some design charts are included
   /
5158
a particular case of the application of the matrix method to radio
engineering  use of the matrix method in analysis of the operation
of quadripoles including thermionic valves or transistors is discussed
a simple method is proposed for carrying out the necessary transformations
to the formulae on passing from the one case to the other
   /
5159
application of electron spin resonance in a microwave oscillator
or amplifier
   /
5160
constant frequency oscillators  comment on
   /
5161
bridge stabilized oscillators and their derivatives  reprinted from
general analysis is presented for the operation of the bridge stabilized
feedback oscillator and modifications obtained by interchanging bridge
elements crosswise or by unbalancing the bridge are discussed
   /
5162
frequency stability and quartz controlled oscillators  the operation
of some commonly used types of crystal controlled oscillator is reviewed
frequency can be held constant to within a factor of over period
of months by using a bar crystal resonator
   /
5163
bistable circuits using triode pentodes  note on the operation of
multivibrator type circuits in which one feedback path is provided
by connecting triode anode to pentode screen leaving one grid free
for triggering gating or modulation
   /
5164
simple method for producing pulses of short duration and large amplitude
pulses of duration about and peak to peak amplitude about are
obtained from the tuned secondary of a transformer in the cathode
circuit of a thyratron
   /
5165
applications for tandem transistors  the tandem transistor consisting
of two transistors housed in a single container and cascaded so that
one acts as the base leak for the next may be used as an amplifier
with high input impedance and in various applications in which single
grounded emitter stages are normally used
   /
5166
superregenerative transistor oscillator  the circuit described generates
pulses of tone at a rate of  the performance with different values
of quench capacitor bias feedback is shown graphically
   /
5167
investigation of special frequency dividers with large dividing ratio
two frequency dividers and one pulse counter are developed on the
basis of kroebels work  these give stable dividing ratios of and
at input pulse frequencies of and respectively  the counter can handle
irregular pulses spaced at intervals of
   /
5168
a new high slope multigrid valve and its application in pulse and
switching circuits
   /
5169
a point contact transistor scaling circuit with resolution  simple
circuits using normal point contact transistors are described features
contributing to the short resolving time are the prevention of bottoming
of collector potential and the absence of capacitors  a typical scale
of ten circuit uses seven transistors seven pulse transformers and
crystal diodes  wide tolerances on the transistor parameters are
permissible
   /
5170
a junction transistor scaling circuit with resolution  the basic
circuit discussed is a binary scaler using a differentiating transformer
instead of capacitors for coupling the speed of operation thus depends
only on the transistor characteristics  scale of and scale of circuits
built up from the basic circuit are described
   /
5171
disc seal triode amplifiers  the design of a resonant type coupling
network for discseal triodes operating in the earthed grid connection
at frequencies in the range is considered  a coaxial form of line
is adopted  tuning for a small range can be by a screw or for a larger
range by a built in capacitance  complete amplifiers can give output
and gain using three stages
   /
5172
higher pentode gain  note on the use of a transistor as an anode
load
   /
5173
noise in an amplifier stage with negative voltage feedback  the problem
is considered with particular reference to the input circuit of an
amplifier for a magnetic tape recorder  analysis indicates that frequency
distortion inherent in the system can be corrected by use of negative
feedback at the input valve and indicates the existence of an optimum
ratio for the input transformer from the point of view of signal
noise ratio
   /
5174
triode cathode followers for impedance matching to transformers and
filters  design curves derived from measurements on five different
types of triode are presented
   /
5175
an improved type of differential amplifier  a differential amplifier
stage capable of giving a high rejection ratio with unselected valves
and components and without a balance control is analysed and a particular
amplifier is described in some detail  the stage is particularly
suitable for converting balanced to unbalanced signals
   /
5176
comparison of some magnetic amplifier circuits with internal feedback
   /
5177
push pull magnetic amplifier with direct current output
   /
5178
decicycle magnetic amplifier systems for servos  digest of paper
published in  improvements in circuitry and core materials and the
adoption of pulse techniques make possible systems whose response
times are one tenth to one hundredth of a cycle of the power supply
frequency
   /
5179
a ferrite microwave modulator employing feedback  an amplitude modulator
with good linearity is obtained by applying feedback to a gyrator
comprising a ferrite rod in a circular waveguide section interposed
between rectangular waveguide sections  the feedback circuit is based
on linear detection of the amplitude modulation by means of a crystal
limitations of the arrangement are discussed  good results have been
obtained with sinusoidal modulating signals of frequencies up to
   /
5180
handbook preferred circuits navy aeronautical equipment  gives design
details and characteristics of the standardized circuits discussed
previously  supplements are to be issued from time to te
   /
5181
linear feedback analysis  a useful introduction to the subject
   /
5182
electron plasma oscillations in an external electric field  the oscillation
frequency is calculated assuming that the electron distribution
function satisfies a given kinetic equation
   /
5183
fields and stresses in dielectric media  expressions are obtained
for the mechanical forces at the boundary of an isotropic dielectric
caused by an electric field  results are verified in particular cases
by electrolyte tank experiments
   /
5184
on the energy dissipation of conduction electrons undergoing elastic
scattering by impurities  a brief theoretical note on the mechanism
responsible for the energy dissipation in conduction in metals
   /
5185
theory of galvanomagnetic phenomena in metals  the theory is developed
without making any special assumptions regarding the conduction electron
dispersion law and the form of the collision integral
   /
5186
anomalous skin effect assuming arbitrary collision integral  results
of a calculation of the surface impedance show that the ratio equals
for an arbitrary electron dispersion law and an arbitrary collision
integral is proportional to and is independent of temperature in
the anomalous skin effect temperature range
   /
5187
statistics of electron avalanches in a uniform field  the statistical
distribution of the number of charge carrier pairs about the mean
was determined experimentally by measurements on discharges in ethyl
alcohol  results agree with theory
   /
5188
surge voltage breakdown of air in a nonuniform field  experiments
on discharges between a spherical and a plane electrode are described
and a tentative explanation of the breakdown mechanism is presented
   /
5189
investigation of a discharge in the frequency region between high
frequency and audio frequency at low gas pressure
   /
5190
investigation of the high frequency discharge  the dependence of
the ignition and operation potentials in and on the gas pressure
and the geometry of the discharge space was investigated in the frequency
range  results presented graphically are in agreement with the
diffusion theory of
   /
5191
influence of an adsorbed film of dipole molecules on the electron
work function of a metal  experimental results indicate that films
of molecules decrease he work function of by up to as compared with
a decrease of up to produced by
   /
5192
auger electron emission in the energy spectra of secondary electrons
from and  analysis of the observed energy distributions of the secondary
electrons for a range of primary energies reveals subsidiary maxima
at points along the energy axis characteristic of the target meterial
but independent of the primary voltage the positions of these points
are consistent with an auger process origin for the electrons with
these energies
   /
5193
investigation of the inelastic reflection of electrons by a cuprous
oxide surface  the energy losses of electrons on reflection at monocrystalline
or polycrystalline surfaces are equal to the energy required
to transfer electrons of the crystal lattice from filled to permitted
zones  the mechanism involved is similar to that responsible for
the appearance of discrete groups of true secondary electrons
   /
5194
production and use of high transient magnetic fields  technique for
the production of pulsed magnetic fields of strength or over is discussed
capacitor discharge arrangements are used with impact resistant
solenoids comprising massive single layer helices  pulse durations
range from to  measurement of the magnetoresistance of is one of
the applications mentioned
   /
5195
radio frequency physics  brief report of the annual conference held
at geneva of the organization which is concerned with the use of
radio frequencies in the various branches of physics  some papers
were presented the subjects including dielectric and magnetic properties
electron resonance of various types and associated effects and microwave
spectroscopy  which gives papers from the conference held at paris
covering a similar range of subjects and including also some material
on atmospheric physics
   /
5196
application of electron spin resonance in a microwave oscillator
or amplifier  a brief analysis indicates the condition for a paramagnetic
substance located within a cavity resonator and subjected to a
direct magnetic field to supply power instead of absorbing it from
the field  results of preliminary experiments indicate that it should
be possible to produce oscillations using a small sample of si containing
a suitable impurity providing a concentration of about paramagnetic
centres per
   /
5197
radiation from molecules in the presence of a strong high frequency
field  it is shown that in addition to an absorption of the energy
at a frequency where are energy levels of the molecule emission takes
place at a frequency which is a function of the matrix element of
the dipole moment corresponding to the transition and the field strength
of the field  in a typical case and the field strength is the value
of is then approximately  the radiation is only present if the elements
and are not equal to zero
   /
5198
fourier transform method for the treatment of the problem of the
reflection of radiation from irregular surfaces
   /
5199
incidence of an electromagnetic wave on a cerenkov electron gas
analysis is presented for the interaction of an wave in a retarding
medium with an electron gas moving through or near the medium at
a velocity exceeding that of the wave in the medium  for electron
densities exceeding a critical value the gas acts as a mirror for
the incident wave  possible laboratory experiments for investigating
the problem are outlined
   /
5200
method of calculating electromagnetic fields excited by an alternating
current in stratified media  the expressions for the field due to
a dipole in the boundary of a stratified half space are developed
in a form suitable for evaluation by a modern computer  the characteristics
of the strata are assumed to be independent of time and of the
field the permeability is constant and the conductivities are arbitrary
the conductivity of the surface layer is finite
   /
5201
absorption devices for centimetre electromagnetic waves and their
acoustic analogues  a survey of the operating mechanism of three
types of absorbers homogeneous material wedges and resonance absorbers
   /
5202
thermo and galvano magnetic effects in strong fields at low temperatures
thermoelectric force resistance and hall effect of a metal in
a magnetic field at low temperatures are calculated using a two zone
model of the metal
   /
5203
an investigation of monochromatic radio emission of deuterium from
the galaxy
   /
5204
gravitational influence of jupiter on some geophysical phenomena
consideration of astronomical observations from ancient times onwards
has indicated apparent variations in astronomical time  attention
is drawn particularly to a variation having a period of years this
is also the period taken by the sun the earth and jupiter to return
to the same alignment and relative distance  it is suggested that
the combined gravitational action of the sun and jupiter causes tidal
motion in the earths crust the apparent variation of astronomical
time corresponding to a real displacement of the meridian
   /
5205
atmospheric attenuation of solar millimeter wave radiation  measurements
have been made of the absorption of solar radiation by atmospheric
water vapour at wavelengths down to about  the results are combined
with theoretical formulae for the absorption spectrum of water vapour
   /
5206
origin of the meinel hydroxyl system in the night airglow
   /
5207
a photometric unit for the airglow and aurora
   /
5208
note on the variations of atmospheric ozone as a function of height
observations confirming those of paetzold are reported
   /
5209
symposium on ionospheric drifts  brief report of symposium held at
new delhi i
   /
5210
accurate height measurements using an ionospheric recorder  a method
for the calibration of an ionospheric recorder is described which
corrects errors in height measurement arising from the distortion
of the echo pulse in its passage through the receiver  the amount
of this error depends on the echo amplitude and is shown to vary
in an approximately linear manner with the width of the recorded
echo trace  several methods of checking the calibration confirm that
it is reliable to within  using a calibrated recorder and an expanded
timebase it is possible to measure region equivalent heights to this
order of accuracy  the systematic error due to pulse distortion will
in general cause the heights recorded in routine ionospheric measurements
to be from to too high  some consequences of this for predictions
are mentioned
   /
5211
monthly mean values of ionospheric characteristics at rome in the
period  hourly values are tabulated for the critical frequency and
virtual height of the and layers and for the percentage of occurrences
of the layer  brief particulars are given of the sounding schedule
operated and the conventions adopted in the calculations
   /
5212
sporadic echoes from the region over ahmedabad  an analysis is made
of records for the sunspot minimum period  the diurnal and seasonal
variations of as a whole are interpreted as variations in the relative
contributions of three distinct types of namely a thin layer observed
at with a maximum frequency of occurrence at late evening which is
observed at with a minimum in the afternoon and maximum towards the
end of the night and at developed by the vertical downward movement
fo the layer and observed only during the daytime
   /
5213
a new theory of formation of the layer  electron pairs generated
in the upper part of the region diffuse rapidly downwards under gravity
but at sufficiently low heights they are rapidly lost by the mechanism
of charge transfer and dissociative recombination suggested by bates
and massey giving rise to a maximum ionization density at a greater
height  this theory gives results in accordance with observations
   /
5214
the structure of the layer as deduced from its daily variations
observed variations in the region may be accounted for by assuming
that in consequence of the decrease with height of the effective
decay coefficient the maximum electron density in the region is at
a level above that of maximum electron production and that vertical
semidiurnal tidal drift is nonuniform  at the level of maximum electron
production the rate of production varies inversely as temperature
an attachment coefficient of at is indicated with a solar temperature
of
   /
5215
geomagnetic control to the diurnal variation of the layer on the
temperate latitude  the longitude effect demonstrated by appleton
is examined  the observed diurnal variation is consistent with geomagnetic
control of the thermal vertical flow in the region  seasonal
variations are also observed
   /
5216
comparison of at four observatories in japan  observations over the
solar activity half cycle are correlated with sunspot numbers  on
a long term basis the magnitude of the variation of is a function
of latitude
   /
5217
negative oxygen ions in the upper atmosphere the affinity and radiative
attachment coefficient of atomic oxygen  the influence of negative
ions of atomic oxygen on the physics of the ionosphere and night
airglow is re examined in the light of new experimental determinations
of the oxygen affinity and photodetachment cross section  the radiative
attachment coefficient is calculated from th photodetachment cross
section  there is no evidence of a resonance at the threshold where
the attachment coefficient is approximately
   /
5218
observations of ionospheric absorption at the  theory of ionospheric
absorption is outlined and measurement difficulties due to fading
are discussed  the procedure at the netherlands station is to determine
the apparent reflection coefficient for vertically incident waves
using pulse transmissions with display of the echo amplitude total
absorption and absorption index are hence derived  the equipment
is described and some results are reported
   /
5219
on the existence of a transition level in the ionosphere and its
experimental evidence and effect
   /
5220
back scatter ionospheric sounder
   /
5221
a correlation treatment of fading signals
   /
5222
on the propagation of whistling atmospherics  it is shown that the
dispersion of whistling atmospherics propagated along the lines of
force of the earths magnetic field should be greatly dependent on
the geomagnetic latitude of the observing point  the change in the
magnetic field intensity along a line of force produces an upper
frequency limit for whistler propagation which at latitudes greater
than should fall within he usually observed frequency region of
dispersion curves showing this critical frequency are given for geomagnetic
latitudes and
   /
5223
sudden decrease in low frequency atmospheric noise during the cosmic
radiation storm of february  note of observations on at churchill
manitoba  the relation of the disturbance to solar flare conditions
and to the proximity of the station to the auroral zone is briefly
discussed
   /
5224
influence of the horizontal geomagnetic field on electric waves between
the earth and the ionosphere travelling obliquely to the meridian
a more general case than that noted earlier is considered briefly
results indicate that the differences in the type of atmospherics
waveform arriving from south east and from south west are due to
differences not in the propagation but in the nature of the discharge
which may occur over the sea in one case over land in the other
   /
5225
the low frequency noise of the geomagnetic field  grenets investigations
of the source of disturbances are discussed  observations made in
the sahara are reported a telephone cable formed into a circular
loop of diameter was used as aerial in conjunction with a multistage
amplifier and pen recorder the total frequency band explorable was
the results indicate that the low frequency pulses received are almost
entirely due to atmospherics this confirms grenets theory
   /
5226
electromagnetic phenomena of natural origin in the band  a report
is presented of observations made at an isolated region in oregon
in the summer of  air core detector coils were used one with an effective
area of for observing the vertical magnetic field component and
another with an effective area of for the horizontal north south
component  voltage waveforms proportional to the field and to its
time rate of change were studied by means of photographic records
from oscillographs  the signals recorded are predominatly of burst
type the horizontal component being more intense than the vertical
the level of activity exhibits a systematic diurnal variation  comparison
with the incidence of atmospherics suggests that the low frequency
signals are associated with lightning while the timing of the daytime
maximum indicates that the propagation mechanism is different from
that for the atmospherics
   /
5227
the propagation  f a radio atmospheric
   /
5228
propagation of audio frequency radio waves to great distances
   /
5229
electromagnetic momentum and elect  on inertia in a current circuit
the magnetic energy of a current circuit is identified with the kinetic
energy of the mass equivalent of the total energy of the conduction
electrons  the concept of momentum in a current circuit is used to
determine the force on the end wire of a long rectangular circuit
and to bring the known effects of electron inertia in a circuit within
the scope of theory  an on off servomechanism with predicted change
over  a general method has been divised f  r achieving optimum switching
with an on off control system  the practicability of predicting the
ideal switching time has been demonstrated with a model experiment
for wich responses to step ramp and parabolic input functions have
been found to compare favourably with those of an orthodox system
   /
5230
the dual input describing function and its use in the analysis on
nonlinear feedback systems
   /
5231
thermoelectric cooling a brief account is given of theory of thermoelectric
cooling published by the academy of sciences moscow and of experimental
results  temperature differences habe been obtained  applications
being investigated include cooling of components in radio and electronic
equipment
   /
5232
diffused junction silicon rectifiers  development types with current
ratings for reverse peak voltages over are described  operation is
satisfactory at temperatures
   /
5233
the forward characteristic of the diode  theory for the diffused
junction diode indicates thet the forward characteristic should be
similar to that of the simple diode until the current density approaches
lnoma ies in the characteristic at low current densities are unrelated
to the presence of the weakly middle region
   /
5234
thermoelectric generators  basic design formulae are given abd discussed
using a semiconductor layer thick with thermoelectric coefficient
a temperature difference of across it and a heat input of a  d assuming
a specific mass of and an efficiency of an output of may be obtained
   /
5235
bibliography of literature on mathematical simulation  about items
are listed including books conference reports and papers  about references
are to russian literature
   /
5236
electronic differential analyser of the krzhizhanovski energetics
institute of the academy of sciences  the analyser comprises operational
amplifiers four multipliers and four function trans ormers with a
harmonics generator  the basic circuits are described  differential
equations up to the order have been solved equations up to the order
could be handled
   /
5237
magnetic shift register correlator  printed decimal digits are easily
recognised by a magnetic shift register using digital to analog converters
at each stage  recognition is obtained using a waveform fitting
function instrumented with the shift register for correlation
   /
5238
triangular wave analog multiplier
   /
5239
high density williams storage
   /
5240
bit storage via electro optical feedback  the use of a device including
a photoemissive cathode and a luminescent anode as a computer component
is discussed
   /
5241
review of industrial of heat transfer to electronics  techniques
for controlling the temperature conditions of operation of electronic
equipment are reviewed with particular reference to conditions in
fast aircraft and missiles  particular examples discussed are an
air cooled valve cold plate techniques for cooling miniature and
subminiature equipment valves designed for operation at surface temperatures
near evaporation cooling of miniature transformers by means
of fluorochemicals  the importance of the subject of heat transfer
to designers of electronic equipment is stressed and training programs
at the massachusetts institute of technology are mentioned
   /
5242
fast rise pulse generator with high pulse repetition frequency  description
of a single pole multi position switch in which mercury is ejected
through a rotating nozzle on to a series of contact pins thus generating
pulses having a rise time at repetition rates with peak pulse power
   /
5243
on concavity of resistance functions  a short proof is given of a
theorem presented by shannon and hagelbarger
   /
5244
ferromagnetic coupling between crossing coils  discussion of the
operation of devices comprising a toroidal and a solenoidal coil
wound on a common cylindrical saturated ferromagnetic core gating
coincidence and signal storage applications are mentioned
   /
5245
self healing in metallized paper capacitors  the physical and manufacturing
techniques involved in the production of truly self healing
single layer metallized paper capacitors are described
   /
5246
decomposition of the derivative of the impedance for a two terminal
network  extension of theory presented previously
   /
5247
design data for ladder networks  design data for networks with up
to nine branches and attenuation curves for networks with up to eleven
branches are presented in expansion of previous work
   /
5248
directional channel separation filters  networks are discussed which
combine the properties of directional couplers with those of conventional
filters such networks are useful for channel combining separating
micro wave communication systems and in installations where a single
aerial is shared by several systems  designs using waveguides coaxial
and strip lines and lumped constant circuits are indicated the performance
of some experimental filters is described
   /
5249
low pass filters for metre waves  filters intended for suppression
of harmonics in measurements and having cut off frequencies of about
comprise three sections with lumped constant components  the construction
and method of adjustment are described
   /
5250
a low pass band pass frequency transformation  a simple transformation
is presented for converting a low pass insertion power ratio into
a band pass ratio the technique facilitates the design of band pass
filters when the attenuation curves on either side of the pass band
are required to be asymmetrical
   /
5251
a unidirectional attenuator with delay line and ferrite element for
the frequency band  the attenuation afforded by various devices comprising
ferrite tubes surrounding helical lines and in turn surrounded
by tubular magnets was investigated experimentally results are presented
graphically  the attenuation obtained with the final design was about
in the forward direction and in the blocking direction
   /
5252
frequency doubling and mixing in ferrites  analysis is presented
indicating th particular polarization and frequency conditions under
which frequency doubling and mixing will occur in ferrite devices
of the type discussed by ayres et al
   /
5253
the derivation of the six terminal network curve its graphical interpretation
and its application in determining the transformation properties
of loss free six terminal and eight terminal networks
   /
5254
tuned circuits containing negative resistance  analysis indicates
that the combination of a current controlled negative resistance
with a parallel tuned circuit or of a voltage controlled negative
conductance with a series tuned circuit yields a bistable circuit
rather than a self sustaining oscillator
   /
5255
the gain characteristic inside the pull in range particularly in
transmitters and wobbulators
   /
5256
oscillator frequency stability  the case of an oscillator connected
to a mismatched load by a long feeder is considered  in addition
to hysteresis effects with resonant loads a type of instability occurs
which takes the form of a periodic modulation of the oscillation
frequency  stability criteria appropriate to both effects are derived
for various circuit arrangements  results of experiments with a triode
oscillator operating at are reasonably consistent with the theory
in general the hysteresis type of instability predominates
   /
5257
novel circuit for a stable variable frequency oscillator  a circuit
designed to reduce the effect of resonator frequency drift uses a
multiloop feedback arrangement with three oscillators maintained
at frequencies such that one is the sum of the other two the sum
frequency being controlled by a quartz crystal while the other two
are controlled by variable resonators  the circuit and frequency
drift temperature characteristics of an experimental oscillator are
shown
   /
5258
hard tube pulsers for radar  developments in design of high vacuum
valves make possible the construction of blocking oscillator pulse
modulators comparable in size and efficiency with line type thyratron
modulators with advantages in stability resulting from the pulse
shape
   /
5259
current derived resistance capacitance oscillators using junction
transistors  two circuits using phase shift networks suitable for
use at very low frequencies and one with a phase shift network giving
a maximum frequency of are described
   /
5260
pulse scaler circuit with high resolving power  a circuit with a
resolving time of is based on a step by step capacitor charge and
a rapid discharge process  the scaling factor can be varied from
without loss of stability  as a frequency divider the circuit is
limited to the range  input pulses must be at least peak to peak
   /
5261
high frequency electronic counter  a circuit suitable for the frequency
divider following the subcarrier generator in a colour television
receiver is based on a triggered binary cascade with feedback  the
high counting rate is achieved by incorporating a gating arrangement
   /
5262
an input amplifier for a pulse height analyser  the analyser described
can be gated by pulses coincident with the pulses to be measured
the error introduced being of the maximum output pulse height  variation
of the input amplification enables the scale to be expanded for detailed
examination of part of a spectrum
   /
5263
a nines complement decade counter with recorder  a brief outline
of decimal counting using weighted binary digits is given with special
reference to systems giving complements of nine  a binary decade
electronic counter arranged so as to allow the reading of nines complements
which may be used to represent negative numbers is then described
in the circuit arrangement used in this counter the maximum counting
rate remains the same as that of a simple binary counter  recording
of the number counted is made on teledeltos paper the record and
counter reset being carried out simultaneously
   /
5264
gate selects pulses for spectrum analysis  a circuit permitting isolation
of pulses from to wide at repetition rates up to per sec is described
   /
5265
nonlinear distortion and stability of reflex circuits  two single
valve and three two valve crystal detector reflex amplifier circuits
are discussed  the coefficient of non linear distortion is calculated
for the various circuits and the results are plotted as a function
of the parameter the relative change of slope of the curve from the
value at the working point due to the applied signal can theoretically
be made zero by using a pair of identical valves in the circuit shown
in the stability criteria are also discussed
   /
5266
decade amplifier  the circuit incorporates rc and direct coupled
stages and a chopper stabilizing amplifier giving a bandwidth of
with a gain of in steps  the equivalent input drift is output is
up to
   /
5267
isolating direct current amplifiers  a circuit providing an output
direct current or voltage proportional to an input direct voltage
and having no common point between input and output uses fixed frequency
crystal controlled oscillator in conjunction with a discriminator
whose phase is varied by means of an electromechanical modulator
which converts the input signal into a capacitance variation  several
applications are mentioned
   /
5268
wide band linear amplifier  the amplifier de  cribed is designed
for use with a common aerial to provide a distribution system for
a ship  frequency coverage is with suppression in the bands nominal
gain is  performance figures are given the level of intermodulation
and cross modulation products is low
   /
5269
synthesis of amplifiers with triple tuned coupled circuits
   /
5270
unity gain voltmeter amplifier
   /
5271
behaviour of saturable reactors in magnetic amplifiers  a detailed
analysis is presented of the behaviour of a magnetic amplifier in
which the core material is assumed to have a square characteristic
systems with single cores two series connected cores and two parallel
connected cores are considered with sources of infinite and low impedance
results are presented graphically upporting experimental evidence
is mentioned briefly
   /
5272
measurement considerations in high frequency power gain of junction
transistors
   /
5273
transistor amplifier for radar video  the design of a video amplifier
suing si transistors suitable for airborne radar systems is discussed
high frequency compensation is obtained by rc degenerative feedback
in a grounded emitter circuit with temperature stabilization of emitter
current bias
   /
5274
transistor preamps  discussion of practical design considerations
for pre amplifiers for use with gramophones with a boosted low frequency
response and a flat response main amplifier and with microphones
the pre amplifier in this case having a flat response
   /
5275
a amplifier employing transistors  the amplifier described comprises
an input stage a driver and a class b stage with overall feedback
the maximum output is measured at with total harmonic distortion
mainly third harmonic  the sensitivity at the input terminal is about
minimum total distortion is at an output of about
   /
5276
design of a simple linear frequency discriminator  the discriminator
described consists essentially of two tuned circuits with the parameters
chosen to minimize second and third harmonics  design information
is presented in graphs
   /
5277
statistical properties of a moving waveform
   /
5278
the giorgi system of units and the rationalization of the equations
of electricity
   /
5279
new theorems on the electrostatic field  the law of least capacitance
is discussed the concept of the intermediate electrode is introduced
to facilitate the formulation  a system of two cylinders with parallel
axes is considered and an examination is made of the variation of
the total capacitance of the system on dis placing the imaginary
intermediate electrode constituted by an infinitely thin metal sheet
shaped to coincide with one of the equipotential surfaces  the analysis
is extended to systems of spheres and other geometrical forms  formulae
giving attractive and repulsive forces for numerous particular cases
are tabulated
   /
5280
field ionization of gases at a metal surface and the resolution of
the field ion microscope
   /
5281
field desorption  report of a study of the action of strong electric
fields in removing adsorbed films of ba th etc from a w surface using
a field emission microscope and maintaining the metal surface positive
   /
5282
electronic conduction in solids with spherically symmetric band structure
elastic scattering of electrons by ionized impurities and inelastic
scattering by the non acoustical modes of the lattice vibrations
in a homopolar crystal are discussed for electrons whose energy is
a nonquadratic function of the wave number vector
   /
5283
acceleration of electrons by an external force field  the usual proof
that an electron in an energy band reacts to an external force as
though it had an effective mass is shown to be invalid  it is shown
however that for static externally applied fields modified energy
bands can be found for which the acceleration theorem is rigorously
correct
   /
5284
the penetration depth in impure superconducting tin  a new method
is described for measuring the surface impedance of metals at low
temperatures and at radio frequencies  using this method the surface
impedance of normal tin and the penetration depth in superconducting
tin have been studied at about frequency as a function of impurity
content  the measured surface impedances agree well with the values
expected and the penetration depths increase with impurity content
in confirmation of pippards observations
   /
5285
cyclotron resonance under anomalous skin effect conditions  results
to be expected from attempts to observe cyclotron resonance in metals
are discussed
   /
5286
mobility and space charge of ions in nonuniform field  teh equations
developed lead to a generalization of the child langmuir power law
to cover the case of arbitrary pressures
   /
5287
the carrier density in a plasma and its determination by means of
the pulse probe  the pulse method discussed does not depend on particular
assumptions regarding the transition layer between the unipolar
layer and the undisturbed plasma  theory apparatus and experimental
results are described
   /
5288
statistical study of electron avalanches in gaseous discharge  for
low pressures the pulse size distribution at potentials below the
breakdown value agreed with that given by the townsend theory assuming
the absence of space charge  at atmospheric pressure the discharge
was modified probably by space charge and pulse size tended to become
uniform
   /
5289
starting of an electrical gas discharge in a uniform alternating
field  in the sub critical range when the half period of the alternating
field is greater than the duration of an ionization step the number
of ionization steps in a half period varies with frequency and with
field strength  over this range the breakdown voltage frequency characteristic
is positive but beyond a certain value of frequency it becomes
negative later undergoing a further inflection so that at a frequency
of it is again positive  comprehensive experimental results illustrating
these phases and the influences of pressure and electrode separation
on them are presented
   /
5290
contact phenomena in plasma  discontinuities of potential between
parts of a plasma which differ in electron concentration and temperature
are considered theoretically by the classical contact potential theory
of metals  the validity of this treatment is confirmed experimentally
   /
5291
investigation of electron emission from superconductors
   /
5292
secondary electron emission from metals under the action of ions
and neutral particles  experimental results obtained by bombardment
of clean metals with ions of and neutral atoms of the inert gases
show that the coefficient of secondary emission increases linearly
at particle velocities up to for proton bombardment a ma imum occurs
at a velocity of
   /
5293
investigation of characteristic energy losses by the retarding field
method  the energy distribution of electrons and the angular distribution
o  their paths after passage through thin foils of and are studied
   /
5294
dependence of secondary electron emission upon angle of incidence
of primaries
   /
5295
secondary electron emission from dielectrics  experiments are described
in which in order to avoid changes in the structure of the target
due to electron bombardment the primary beam was switched on for
only so that there was one incident electron for about atoms of the
emitter surface and the destruction of the target could therefore
be neglected  the results obtained are different from those usually
quoted a new interpretation of the phenomenon is given
   /
5296
model for collision processes in gases small amplitude oscillations
of charged two component systems  continuation of work reported previously
   /
5297
large amplitude plasma streaming and charge segregation
   /
5298
the magnetostatic force on two circular cylindrical conductors carrying
uniform steady currents  the magnetic field dur to two parallel conductors
in a nonuniform magnetic field is determined for the case when
the conductor material si magnetic  general expressions are deduced
for the magnetostatic force and are investigated for particular examples
   /
5299
fluid self excited dynamo  the possibility that a simply connected
perfectly conducting fluid body could generate an increasing external
magnetic field by acting as a self excited dynamo is demonstrated
by exhibiting a cycle of motions that doubled the external field
each cycle  the essential feature of the motion is that interior
points become surface points
   /
5300
analysis of traces of impurities in rare gases by ultra high frequency
excitation of optical radiation  technique is discussed in which
a cell filled at low pressure with the gas to be analysed is arranged
in the field of a continuous microwave oscillation generated by a
magnetron
   /
5301
cerenkov radiation from extended electron beams near a medium of
complex index of refraction  if ferrites are used in place of simple
dielectric media the radiated power can under suitable conditions
be increased
   /
5302
variation with electron energy of the collision cross section of
helium for slow electrons  continuation of previous work on the interaction
of microwaves in gas discharge plasmas  momentum transfer between
atoms and electrons with energies between and is investigated the
electron density being not less than about  experimental results
appear to indicate a slight variation of momentum transfer with electron
energy
   /
5303
motion of a sphere through a conducting fluid in the presence of
a strong magnetic field
   /
5304
basic processes of gaseous electronics  a comprehensive review scattering
and diffraction of radio waves  one of a series of monographs
on mathematical methods are indicated for solving problems encountered
in the study of radar performance and aerial systems
   /
5305
hydromagnetic dynamo theory  the equations of magnetohydrodynamic
are used to study the mechanism whereby cosmic magnetic fields such
as those of the earth of sunspots and the sun and of magnetic stars
are generated and maintained
   /
5306
the nature of radiation from radiogalaxy  the continuous optical
radiation from the jet in the core of the galaxy is explained quantitatively
by the presence of relativistic electrons with energies of
moving in a magnetic field of approximately relativistic electrons
with energies of diffusing into the galaxy are probably the source
of emission
   /
5307
impulsive radio signals from the planet venus  report of reception
at the ohio state university of radiation at a wavelength of  the
observations were made using an interferometer array of horizontal
elements with reflectors  the peak power in a burst is estimated
to be about per of bandwidth this is about of the value estimated
for a burst from jupiter  on the basis of power considerations the
mechanism involved could be o lightning discharge type  a record
obtained on is reproduced and discussed
   /
5308
class radio signals from venus at a wavelength of  reception of radiation
with a different waveform from that discussed previously is reported
this radiation designated class is of a more sustained nature lasting
for a second or longer and varying at an rate  a record of a series
of pulses observed on is shown  the radiation appears to have a bandwidth
of at least  on studying tape recordings signals resembling echoes
were  oted these may be due to reflection from the moon
   /
5309
large amplitude plasma streaming and charge segregation
   /
5310
on the propagation of radio waves through the upper ionosphere
   /
5311
review of ionospheric effects at and
   /
5312
inadequacy of recombination as the source of light from enduring
meteor trains  critical discussion of the suggestion made by that
the column of light produced by a meteor is due to recombination
of the meteoric ions and free electrons
   /
5313
observations of solar radio radiation during the eclipse of  observations
made at cracow using apparatus operating at about with a parabolic
aerial of diameter are reported  records for and are shown for comparison
with those for the eclipse day
   /
5314
a note on the annual variation of geomagnetic activity and regions
results of an investigation are given associating recurrent day geomagnetic
activity with regions of the sun around years of sunspot minima
the association of sequences with various solar features of the disk
and corona is also indicated  for a longer account of related work
see
   /
5315
charge transfer in the upper atmosphere  collision processes involving
charged solar particles entering the upper atmosphere are discussed
charge transfer reactions involving solar and ions are likely to
excite spectrum lines of these elements and of the atmospheric gases
in the case of at auroral levels  the ratio of the density of to
ions and the effective recombination coefficient for the layer are
derived
   /
5316
on a pitot tube method of upper atmosphere measurements  a method
is presented for deducing atmospheric density pressure and temperature
at heights up to
   /
5317
thermodynamic method for measurement of the refractive index of the
atmosphere  description of the radiosonde  apparatus is described
which is capable of determining the distribution of temperature pressure
and humidity variations with a fineness sufficient for radio propagation
calculations
   /
5318
the altitude of the line in the night airglow measured from a rocket
measurements using rocket borne photometers show that the layer from
which the line originates lies between and with peak luminosity between
and
   /
5319
distribution of the night airglow and layers measured from a rocket
an experiment similar ro that described by confirms the results for
the line and shows that the sodium lines are excited in a layer of
altitude between and
   /
5320
determination of the alpha ray emission of materials constituting
the earths surface  it is concluded from measurements that ray emission
is not an important factor in the ionization balance of the lower
atmosphere
   /
5321
influence of magnetic field on convective instability in the atmospheres
of stars and in the ionosphere of the earth  the case of a medium
with anisotropic electrical and thermal conductivities is considered
in a plasma which does not contain a large number of neutral particles
the calculated influence of the magnetic field on convection is essentially
different from that predicted by the magnetohydrodynamic approximation
in the ionosphere the influence of the magnetic field is small
owing to the presence of a large number of molecules
   /
5322
electron resonance in ionospheric waves  certain features of large
scale travelling disturbances in the layer are explained as electron
resonance effects whereby small initial disturbances are amplified
estimates of ionospheric parameters based on this interpretation
are in good agreement with values to be expected
   /
5323
two types of development of the layer at ahmedabad  the sequence
of phenomena leading to the separation of and layers after high level
sunrise is summarized and illustrated by photographic records  the
existence of a layer which is photo ionized by solar radiation at
a height of about is indicated
   /
5324
world wide spread  records from widely distributed ionosphere stations
for the period of the last complete sunspot cycle show that the spread
equator is roughly parallel to the geomagnetic equator swinging pf
latitude over the cycle
   /
5325
the solar ray spectrum and the density of the upper atmosphere  data
derived from rocket experiments give a measure of the flux density
of solar rays incident on the layer  from the rate of ray absorption
at heights between and the atmospheric density is computed to be
about one third of the current rocket panel average values
   /
5326
ionospheric effects produced by solar flare radiation
   /
5327
the effective recombination coefficients in the and layers during
the solar eclipse of  the contribution to the ionization of each
of two isolated sources of radiation assumed to exist near the east
and west limbs of the sun is derived and expressed as a linear function
of where is the effective recombination coefficient during the eclipse
on equating the corresponding functions for khartoum and ibadan it
is found that for both places as against the value obtained for khartoum
on assuming that the intensity of ionizing radiation fell to zero
at second contact  for the layer it is concluded that
   /
5328
interpretation of ionospheric measurements made during solar eclipses
by combining observational data obtained at khartoum and ibadan during
the eclipse of a determination is made of the recombination coefficient
in the layer the most probable value is  this result is at variance
with the conclusions reached by and implies absence of radiation
from the corona
   /
5329
ionospheric observations during the solar eclipse of  strong ionization
prevented the accurate observation of but was reliable and assuming
complete cut off of the ionizing radiation at totality gave  the
layer data are consistent with a solar model in which and of the
radiation was emitted from areas near the west and east limbs respectively
originated in an undefined area which may cover the greater part
of the suns disk  the changes in indicate a marked solar control
of the layer and assuming a recombination law give  measurements
absorption are consistent with the solar model deduced from the layer
data and give  a theoretical treatment is given of the eclipse changes
in the region
   /
5330
systematic investigations of the influence of geomagnetic activity
on the nocturnal critical frequencies of the layer  results of a
statistical analysis of data covering a period of years are presented
graphically  the probability that a geomagnetic activity index of
magnitude determined over a period is followed by an ionospheric
storm is in the summer of a sunspot maximum year and in winter the
corresponding figures for a index in a sunspot minimum year are respectively
   /
5331
ionospheric absorption at dakar
   /
5332
calculation of charge density distribution of multilayers from transit
time data  a method is discussed for calculating the electron density
distribution in the ionosphere from data obtained using a rocket
borne variable frequency transmitter or pulse reflections from higher
layers  it is not possible to obtain a solution free from ambiguity
   /
5333
characteristics of auroras caused by angular dispersed protons
   /
5334
secondary processes due to absorption of the lyman lines emitted
from aurorae  discussion indicated that the line of the hydrogen
lyman series emitted from aurorae my be effective in ionizing in
the lower atmosphere but not to the extent required for polar blackouts
absorption of the lyman line by oxygen atoms is not significant in
ordinary aurorae
   /
5335
on the waveform of a radio atmospheric at short ranges  calculated
values for the waveform at various distances up to from the discharge
are shown graphically the ionospherically reflected wave is not taken
into account and the discharge producing the atmospheric is represented
by an idealized function
   /
5336
a balanced unregulated dual power supply  a circuit is described
for simultaneously providing positive and negative voltages which
remain equal in face of line voltage variations practical details
are given for a unit supplying  a graph shows the performance of
the unit used with a amplifier providing a balanced load
   /
5337
semiconductor solar energy converters  a concise review of the physical
fundamentals includes brief discussions of radiant energy absorption
in semiconductors the effect of junctions and the energy conversion
efficiency
   /
5338
efficient and reliable transistor high voltage power supply  the
system comprises a battery a transistor oscillator crystal rectifier
and corona type regulator the output is about at
   /
5339
life test results on selenium rectifiers  tests on a representative
selection of rectifiers for radio and television equipment show very
great variations in shelf life useful life and temperature characteristics
the need for drastic derating is suggested
   /
5340
trends in computer input output devices
   /
5341
design of computer circuits for reliability  factors influencing
the choice of components and precautions taken during the initial
circuit design and mechanical construction of the edsac machine are
described
   /
5342
a circuit for analogue formation of  a quarter squares multiplier
using a triangle carrier waveform in the squaring circuits is extended
to give division simultaneously with multiplication  this is achieved
by controlling the slope of the triangle carrier waveform so as to
be proportional to the divisor z
   /
5343
an automatic electron trajectory tracer
   /
5344
standards on electronic computers definitions of terms
   /
5345
high temperature components  new materials and methods of production
to meet service demands are briefly described
   /
5346
printed circuits
   /
5347
winding method for coils with parallel windings  theory is presented
indicating the purpose for which parallel wound coils are suited
and practical examples are described
   /
5348
p n p n transistor switches
   /
5349
ten channel time division multiplexer  a magnetron beam switching
tube forms the basis of a contact single channel circuit giving switching
times of about  the tube is used in conjunction with a gating
system a gate circuit is described which permits the examination
of signals in the microvolt range
   /
5350
nonlinear tuned capacitors  the design and production of very small
tuning capacitors using ba sr titanate ferroelectric dielectrics
is described  examples are given of applications to oscillators for
the frequency range with power outputs of
   /
5351
formulae relating some equivalent networks  explicit formulae are
obtained for the elements of a network without transformers which
has the same driving point impedance as an arbitrary two loop passive
network
   /
5352
an existence theorem for driving point impedance functions
   /
5353
waveguide components with nonreciprocal properties  the mechanism
of the nonreciprocal effects occurring when an e m wave is propagated
through a magnetized material particularly a ferrite is discussed
the gyrator the isolator and the circulator are described
   /
5354
further aspects of the theory of the maser
   /
5355
variation of the quality factor of piezoelectric crystals as a function
of pressure  measurements were made on a quartz crystal and on a
rochelle salt crystal using apparatus described  results are presented
as curves for values of log  decrease of pressure below about does
nor affect value design of a toroidal cavity resonator by the method
of curvilinear coordinates  the application of the formulae derived
is illustrated by a calculation of the resonance frequency of a cavity
of given dimensions  the calculated value agrees well with the experimental
value restrictions on the shape factors of the step response
of positive real system functions  extension of previous analysis
of the transient response of networks
   /
5356
theory of nonlinear coupling in a novel ferro electric device  a
device which can be used as a modulator or as a frequency divider
or multiplier comprises a block of ferroelectric material witnh electrodes
arranged on two pairs of facing sides  on connecting an inductance
across one pair of electrodes a resonant circuit is provided in which
the capacitance varies periodically oscillations being sustained
when the frequency of this parametric excitation is twice the resonance
frequency of the circuit  analysis is presented using the mathieu
equation
   /
5357
the analysis of three terminal null networks  a simple method of
analysis is presented the twin t and bridged t networks are treated
as examples
   /
5358
by pass filters  by pass filters are described having three pairs
of terminals and between two of the pairs but only a limited band
of frequencies is transmitted between either of these pairs and the
third pair of terminals
   /
5359
an improved crystal band elimination filter  an all pass network consisting
of two filters in parallel is described suitable for applications
in which it is required to transmit a wide frequency bands within
the range  internal impedance transformations eliminate the need
for high ratio transformers
   /
5360
the field displacement isolator  a nonreciprocal device with forward
loss about and reverse loss about over a wide band at about is based
on use of a single ferrite slab spaced from the wall of a rectangular
wave guide and having a resistive strip on one face  optimum field
conditions in the waveguide are discussed
   /
5361
operation of an amplitude limiter  theoretical and experimental evidence
suggest that the stray capacitance shunting the nonlinear element
causes a parasitic phase modulation of the out put signal and limits
the efficiency  a neutralized circuit is shown and design formulae
are given
   /
5362
two terminal junction devices for frequency conversion and computation
   /
5363
mutual synchronization of three coupled oscillators with weak couplings
the syst  m investigated theoretically and experimentally comprises
three triode valve oscillators coupled by small capacitors between
the grids of the first and second and second and third valves  approximate
expressions are derived for the frequency and amplitude of the
oscillations in each oscillator  the regions where mutual synchronization
takes place are shown in a graph where are respectively the frequency
differences between the first and second and the third and second
oscillators
   /
5364
stable local oscillator for s band radar  a continous frequency range
of is obtained using six crystal oscillators tunable over over lapping
ranges of  the desired output frequency is obtained by means of harmonic
amplifiers
   /
5365
a possible construction of amplitude analysers  a circuit is described
by means of which pulses with amplitudes exceeding or lying within
certain limits can be counted
   /
5366
influence of large fluctuations on an electronic relay  the probability of
untimely triggering by fluctuation voltages is considered theoretically
the cases discussed include the effect of fluctuations on a
relay with or without inertia both in the presence and in the absence
of regular pulses the effect on a coincidence type circuit is also
discussed
   /
5367
effect of component tolerances in low frequency selective amplifiers
some experimental results  results obtained previously by analysis
of may have been verified experimentally using the operational amplifiers
of the analogue computer of january trailing edge of pulse in
cathode follower eith capacitive load  the decay time of a rectangular
pulse at the output of a cathode follower can be shortened by connecting
a triode in parallel with the cathode resistor and capacitor and
controlling the triode grid voltage coupling from the anode of the
cathode follower tetrode valve  the circuit constants are such that
the triode impedance decreases momentarily at the end of each pulse
   /
5368
the design of tetrode transistor amplifiers  methods are discussed
for determining suitable loads when the two port parameters of the
transistor are known  charts are presented ofr determining power
gain and input impedance as functions of load  circuits described
as examples include a common base amplifier a common emitter video
amplifier and amplifiers centred at and respectively  predicted and
measured gains are compared
   /
5369
servo amplifiers use power transistors  high efficiency in a class
amplifier using power transistors is obtained by providing the collector
power by full wave rectification of the power supply
   /
5370
micro power operation of silicon transistors
   /
5371
interferometric spectroscopy in the far infra red  the response of
a thermal detector to the resultant of two interfering infrared beams
wal measured using a reflection interferometer with the path difference
varied up to  the spectral information is displayed in a fourier
transform obtained by analysis of the resultant intensity path difference
curve  an instrument with aperture has been made for studying
atmospheric transmission at submillimetre wavelengths
   /
5372
an extension of the circle and sphere theorems  theory relating to
cylinders and spheres immersed in two and three dimensional electric
fields is extended to include certain other boundaries along which
either the electric potential or the current function takes a constant
value
   /
5373
on the bohm pines theory of a quantum mechanical electron plasma
analysis indicates that as a result of neglecting certain conditions
discussed by adams the bohm pines theory may give incorrect results
   /
5374
concerning the papers by s e khaikin s v lebedev and l n borodovskaya
criticism of papers abstracted and back references
   /
5375
integrals of interest in metallic conductivity
   /
5376
oscillations and fluctuations in gas discharges  a tentative classification
is made of different forms of disturbance encountered in gaseous
conductors constituted by low pressure tubes  a distinction is drawn
between cases where the gaseous conductor acts as a circuit unit
possessing resistance capacitance and inductance any of which may
be positive or negative and cases where internal disturbances occur
in the gaseous con ductor which are practically independent of the
external circuit  the origin and nature of electron an ion oscillations
is discussed
   /
5377
electrical breakdown in argon at ultra high frequencies  report of
measurements made using resonant cavities at a frequency with pressures
ranging from
   /
5378
thermionic emission field emission and the transition region  the
combined thermionic and field emission from a metal is studied as
a whole a general expression is derived in the form of a definite
integral relating the emission current to the field the temperature
and the work function  modified forms of the richardson schottky
and fowler nordheim formulae are shown to be respectively valid over
limited regions of low field and high temperature on the one hand
and low temperatures and high field on the other  and expression
is also derived for the emission current in the transition region
   /
5379
secondary electron emission from single crystals of alkali halide
compounds  experiments were caried out which show that the dielectrics
investigated differ from metals in respect of the dependence of the
coefficient of secondary emission on the energy of the primary electrons
and also in respect of the secondary electron energies which in this
case are approximately uniform
   /
5380
field of a uniformly charged disk and magnetic field of a thin circular
cylinder coil with contiguous turns traversed by a direct current
the field of the uniformly charged disk is used to study that of
the coil by virtue of the magnetic ee between the coil and a magnet
of the same shapquivalence between coil and magnet and same shape
with opposite magnetic poles on the two end faces  formulae for mutual
and self inductance are hence derived
   /
5381
electrodynamics of moving media and the theory of the cerendov effect
the generalized frank andtamms formula fot the total energy radiated
as cerenkov radiation by a swiftly moving charged particle in a medium
of dielectric constant and permeability has been derived employing
the invariance of the phenomenological electrodynamic equations of
maxwell  the scheme is self consistent and the idea of the indetectability
of the ether wind is contained in it  it is found that the cerenkov
radiation is times larger than that predicted by the frank and tamms
formula for  experiments are suggested to detect strong cerenkov
radiation in highly permeable mediums
   /
5382
pulsed coherent generation of millimetre waves by nonrelativistic
electron bunches  the production of microwaves by bunched electron
beams incident on metallic or dielectric anticathodes or by interaction
with strong localized fields is briefly discussed and energy relations
are stated
   /
5383
the effect of the surface curvature of a convex metal body on the
radiation from a source on its surface  the radiation is usually
calculated fron reflection formulae derived by replacing the convex
surface by a plane  the magnitude of the error thus introduced is
estimated
   /
5384
the diffraction of a cylindrical pulse by a half plane  a method
of analysis is used which enables the greens function to be derived
two transformations and two inversions are involved
   /
5385
diffraction pattern in the plane of a half screen  measurements are
briefly reported for the case of plane polarized radiation incident
normally on a half plane and polarized parallel to the diffracting
edge  the results are discussed in relation to a formula derived
by andrews and the observations of harden
   /
5386
integro differential equations and babinets principle for plane screens
with directional conductivity  analysis is presented for diffraction
by screens formed of parallel conducting wires  four cases are distinguished
a finite parallel wire screen alone nondirectionally conducting
screen surrounded by an infinite parallel wire screen  cases and
are complementary in the sense of babinets principle so also are
cases and  there is no special relation between cases and or and
   /
5387
electromagnetic radiation from electron plasma  theory developed
by bohm and pines and back references is extended to treat the coupling
between longitudinal and transverse plasma oscillations arising from
the quantum fluctuation of electrons interacting with the field
the theory may provide the explanation of the outbursts of solar
emission  molecular ringing  semiclassical radiation theory is used
to describe the response of an assemblage of two state molecules
driven by an electromagnetic field  when the field is suddenly removed
the assemblage does not immediately become quiescent it continues
to radiate in diminishing amount  this coherent molecular ringing
return to the values they had at the beginning of the driving pulse
the ringing radiation may exhibit a delayed peak
   /
5388
radiation of electromagnetic waves during the uniform motion of electric
charges near an inhomogeneity  the radiation occurring in nonuniform
waveguide in which a given convection current is flowing and the
transient radiation due to the passage of finite bunches of charge
through ideally conducting grids are considered theoretically using
the methods of perturbation theory
   /
5389
theory of molecular oscillator and molecular power amplifier
   /
5390
further aspects of the theory of the maser  problems relating to
saturation effects and cavity resonator design for the device discussed
previously of february are examined various types of noise and oscillator
frequency shift are considered  the theoretical minimum detectable
beam intensity when the maser is used as a spectrometer for the ammonia
line is about molecules sec under typical experimental conditions
   /
5391
a general purpose electromagnet  details are given of a magnet for
laboratory purposes with a soft iron yoke having low residual magnetism
and poles of diameter together with a table showing the variation
of the field in the centre of the gap with excitation and gap length
distribution of radio stars  a tentative explanation is given of
discrepancies between the distribution derived by ryle from interferometer
measurements at and that derived by pawsey from mills cross measurements
also at as discussed at the recent jodrell bank symposium
   /
5392
the radio source near the galactic centre  recent observations on
with the cross aerial are discussed in relation to earlier observations
on and  the position of the dominant source is shown on a contour
map of equivalent brightness temperatures  alternative models accounting
for the observations and involving adsorbing regions are mentioned
whichever model is assumed the nucleus of stars in the galaxy is
not itself detectable as a source
   /
5393
polarization measurements on three intense radio sources  measurements
have been made on radiation of wavelength from sources in cygnus
cassiopeia and taurus  the results indicate that there is no plane
polarized component and no circularly polarized component in the
flux from the first two of these sources the corresponding figures
for the source in taurus are and respectively the george r agassiz
radio telescope of harvard observatory  the aerial of this instrument
is a paraboloid of expanded aluminium wire mesh with a horn collector
at the focus  at wavelength the angular resolution is about thus
the accuracy of setting and following is more than sufficient for
research on discrete radio sources  the receiver is a double conversion
superheterodyne comparison radiometer with a channel comb filter
at the second conversion frequency  the instrument is to be used
both for research and training
   /
5394
some factors affecting the radio determination of meteoric velocities
questions raised by hoffmeister of february are discussed further
deceleration of meteors along the path prior to the point of measurement
may br an important factor techniques for measuring the deceleration
over an appreciable path length by the radio amplitude time method
require to be developed  existing techniques may be failing to detect
faint meteors with hyperbolic orbits
   /
5395
radar echoes from meteor trails under conditions of severe diffusion
an expression is derived indicating that the power of the echo is
proportional to and to where is the range  for a given meteor velocity
there is a critical height above which the effects of diffusion become
serious  a graph shows the critical height velocity curves for values
of between and
   /
5396
the multiple aerial interferometer at the nancay station
   /
5397
radio frequency observations of the solar eclipse of june  radio
frequency power received from the sun at wavelengths of and was measured
during the solar eclipse of junce  the sun was essentially free from
active areas and the eclipse curves obtained have been used to derive
models give predicted eclipse curves in good agreement with the observed
ones  comparison has been made with models derived by other investigators
on the same wavelengths
   /
5398
the constancy of the scale of the relative sunspot numbers  comparison
of sunspot numbers with the greenwich data for sunspot areas over
several cycles indicates that the proportionality factor increases
with the latter but there is no significant variation of the scale
of the relative sunspot number
   /
5399
effective geomagnetic equator for cosmic radiation  the distribution
of the geomagnetic field extending far from the surface of the earth
is investigated by using cosmic ray particles as probes  measurements
using the neutron intensity from the nucleonic component indicate
wide discrepancies between the observations and geomagnetic coordinates
derived from surface magnetic field measurements  some anomalous
observations of cosmic rays can be explained as due to the interaction
of the rotating and inclined magnetic dipole field with a highly
ionized interplanetary medium
   /
5400
theory of solar eclipse effects on the earths magnetic field  the
deformation of the current during a solar eclipse is represented
by a current function which is superposed on the system and moves
with the eclipse  the magnetic field components of are computed and
the influence of the part induced in the earths crust is discussed
   /
5401
upper air density and temperature by the falling sphere method  technique
and results are described of a method for investigating the atmosphere
at heights up to  a nylon sphere with a transponder aeriel erected
a rocket near the peak of its trajectory
   /
5402
turbulent mixing theory applied to radio scattering
   /
5403
an experimental investigation of the band of ozone in the solar spectrum
mean heights of atmospheric ozone have been investigated over
a period of two years using strongs method  a seasonal variation
is observed with a minimum height in summer and range of
   /
5404
determination of the vertical distribution of ozone from emission
spectra
   /
5405
electron density in a nonisothermal ionosphere  continuation of work
noted previously of electron density when the earths curvature is
taken into account may be appreciable especially for the winter the
corresponding difference in critical frequency may amount to for
the period just after sunrise  comparison of calculated and observed
values of suggests that a representative model of an region can be
based on the assumption that the temperature varies linearly with
height up to the interface and then remains constant  the parabolic
law of variation of electron density is acceptable only for heights
corresponding to reflection frequencies not less than times the critical
frequency  a general expression is derived relating temperature electron
density density of matter recombination coefficient and adsorption
coefficient
   /
5406
resonance scattering by atmospheric sodium part theory of the intensity
plateau in the twilight airglow  numerical results based on theory
of radiative transfer are compared with observations by various workers
for a layer scattering solar d line radiation observed in the zenith
distance  winter observations indicate an absolute brightness slightly
greater than given by the theory  abundance of na appears to vary
between summer and winter atoms
   /
5407
the effect of ambipolar diffusion in the night time f layer  the
effect is examined in the light of recent low estimates of the density
of neutral particles in the f layer and assuming that the rate of
loss of electrons is proportional to the electron density  with certain
other simplifying assumptions may be expressed as a sum of functions
which decay exponentially with time an approximately parabolic chapman
model based on the most slowly decaying of these is discussed  correlation
is found between both and magnetic figure and the sunspot cycle
variation of the f region temperature
   /
5408
observation at akita of ionospheric drift  simultaneous observations
of the variations with time of the virtual heights of the layers
were made at three observatories in japan during the period july
august mainly at night  drift velocities of the layers are deduced
the results are presented in the form of histograms
   /
5409
lunar variations of the layer at ibadan  analysis and determinations
for the layer made at ibadan from december to april shows semidiurnal
lunar variations of considerable amplitude these variations in turn
exhibit marked variations of amplitude and phase with season and
with time of solar day  values of the recombination coefficient in
the layer deduced from the luni solar variations decrease exponentially
with increasing height
   /
5410
behaviour of the ionosphere at rome during the partial solar eclipse
of june  observed eclipse effects are compared with effects calculated
on the assumption that the electrons are produced by photo ionization
and removed by ionic recombination or attachment ot neutral atoms
and molecules and that the ionizing radiation is distributed uniformly
over the visible disk of the sun  it is deduced that the electron
loss rate is consistent with an ionic recombination process in the layer
the attachment and recombination coefficients decrease with increasing
height their variations during the eclipse are related to the vertical
movements of the ionosphere  seasonal variations between effects
observed in a number of eclipses are explained in terms of different
degrees of superposition of the and layers  the existence of secondary
minima of electron density is interpreted as indicating that a distinction
must be drawn between the ionizing sun and the visible sun  eclipse
effects in the e layer are also discussed
   /
5411
recombination and attachment in the and layers during the solar eclipse
of december  examination of the variations of electron density at
heights in the region during the annular eclipse of december suggests
that there combination process is predominant in the region in the
region recombination and attachment coefficients decrease regularly
with height  possible explanations of the separation of the and layers
are advanced
   /
5412
theory of nonlinear effects in the ionosphere
   /
5413
ionospheric sounding equipment  the characteristics of the ionosphere
are briefly reviewed and some soundings obtained at the tortosa station
inaugurated in are reproduced  the sounding equipment installed is
identical with that used by the bureau ionospherique francais
   /
5414
ionospheric prediction methods and the probable sources of error
   /
5415
equatorial ionospheric absorption
   /
5416
study of the selective fading appearing on the fct traces
   /
5417
height distribution of auroral emissions
   /
5418
measurement of auroral radiation a with a photon counter  a copper
cathode counter is satisfactory for measuring this radiation
   /
5419
the level of interference due to atmospherics in the very long wave
range and its diurnal and seasonal variations
   /
5420
theoretical considerations governing the choice of the optimum semiconductor
for photovoltaic solar energy conversion
   /
5421
c r t power supply uses transistor oscillator  a positive feedback
oscillator using a transistor provides an output voltage which is
doubled rectified and stabilized at  a collector supply of is the
only external power required  for output current the overall efficiency
is
   /
5422
characteristics for half wave rectifier circuits  voltage regulation
characteristics form factor first harmonic and peak current values
are given for half wave rectifiers with common type loads  all in
non dimensional variables
   /
5423
silicon junction power diodes  simplified semiconductor theory is
presented and a description is given of three main methods of making
junction diodes and of the properties of the diodes  advantageous
features and appropriate applications of these rectifiers are indicated
   /
5424
wide range voltage stabilizers  a unit is described based on a circuit
by admiraal which gives a stabilized output voltage adjustable within
the range with maximum load current of the stabilization ratio is
about
   /
5425
seac national bureau of standards eastern automatic computer  a comprehensive
description see also of is given of this computer which has
been in operation almost continuously since the spring of a  it is
a synchronous machine operating at  it has been expanded from its
original form with increase in the number of thermionic valves from
about to and of ge diodes from about to  circuit modifications include
the introduction of ac coupling using pulse transformers
   /
5426
electronic circuits of the narec  crystal diodes are used where practical
for all nonlinear functions in this digital computer thermionic
valves being used only for inversion or amplification  all circuits
are designed to provide low impedance output signals whose maximum
and minimum levels are held to prescribed potentials  the circuits
are packaged in standard valve plug in units  see also
   /
5427
diagnostic programmes for the illiac  a detailed description is given
of a leapfrog programme for detecting faults this ensures that every
component of the computer is tested under all the different conditions
of use
   /
5428
the logistics computer  construction and operation of a digital computer
for logistics research are described  consideration of the particular
requirements for this work led to a design incorporating high speed
magnetic tape in addition to punched tape input and output equipment
fixed sequence operation magnetic drum storage with capacity for
decimal digits and plug board programming
   /
5429
the remington rand type electronic computer  construction and operation
are described of a machine of moderate size for accounting purposes
using thermionic valves and cold cathode gas diodes  programming
is directed by means of plug boards  there are calculating steps
and special steps and special steps each step is automatically tested
by a reverse process  a reproduce feature is included
   /
5430
the design of the bendix digital differential analyzer  the error
reduction scheme employed by the bendix digital differential analyzer
which utilizes both ternary intercommunication between integrators
and trapezoidal integration is described  a device for the v riation
and automatic resetting of initial conditions is discussed together
with an example illustrating its operation  finally techniques employed
for minimizing the size of the computer are considered
   /
5431
theory of logical nets  two values logic is applied to the study
of digital computer circuits  a logical net is an array constructed
from a stroke element representing circuit components performing
logical functions and a delay element representing storage components
various types of net are defined their properties are correlated
with those of the associated set of equations and a study is made
of the operations they can perform  the classification o digital
computer circuits in this system is discussed
   /
5432
dynamic circuit techniques used in seac and dyseac  the circuits
of these digital computers are standardized on the basis that ge
diodes are used for all logical operations delay lines for storage
and thermionic valves for amplification  manufacture is simplified
by using only two types of plug in unit
   /
5433
the design of logical or and or pyramids for digital computers  recent
improvements in design technique are described leading to reduction
of number of diodes required reduction of voltage and power requirements
and speeding up of operation  basic considerations involved in the
choice of elements are discussed
   /
5434
a survey of digital computer memory systems  a survey limited to
systems whose reaction time is shorter than human reaction time
   /
5435
the logical principles of a new kind of binary counter  auxiliary
temporary storage in a binary counter is provided during intervals
over which the main storage element is in state of change by elements
having the same time indefiniteness as the main storage elements
this leads to a device which has true and false ranks of storage
elements  the basic device is generalized to one with four modes
of operation and the rules of number formation are discussed  application
to a computer is described
   /
5436
combined reading and writing on a magnetic drum  a technique is described
which uses a single head for storing information and reading it
back  design of a suitable amplifier for this method of operation
is discussed  the process can be performed with successive cells
at the repetition rate of sec  the technique extends the use of magnetic
drums to data processing as well as storage
   /
5437
coded decimal number systems for digital computers  from the very
large numbers of possible ways of coding the decimal digits into
sets of binary elements a restricted group of number systems is presented
as being particularly adaptable for representing the decimal digits
in digital computers  as an example one number system of this group
is presented which permits the construction of a very simple addition
circuit
   /
5438
an electromagnetic clutch for high accelerations  unidirectional
and bidirectional models are discussed of a clutch with many possible
applications in the digital computer field
   /
5439
a survey of analog to digital converters
   /
5440
an analog to digital converter for serial computing machines  a two
stage process is used the analogue number being first converted into
a reflected binary or cyclic code number which is then converted
into the binary form as a time sequence with the least significant
digit first
   /
5441
effectiveness of two step smoothing in digital control computers
the use of a digital computer as an element in a control system to
smooth observational data is discussed  analysis is presented for
a two stage system in which the first stage has a high data handling
rate and short smoothing time while the second has a low data handling
rate and a long smoothing time
   /
5442
an input output unit for analog computers  a device is described
which operates as a curve follower type of function generator to
provide an input unit or as an x y recorder when used as output unit
   /
5443
application of electronic differential analyzers to engineering problems
   /
5444
the solution of partial differential equations by difference methods
using the electronic differential analyzer
   /
5445
analog computing applied to noise studies  methods suitable for studying
both linear and nonlinear systems are discussed
   /
5446
edvac drum memory phase system of magnetic recording
   /
5447
dead programmes for a magnetic drum automatic computer  breakdown
due to a wrong instruction can be prevented by blocking part of the
magnetic drum memory for writing and placing in this dead part standard
sub programmes which occur frequently
   /
5448
electrical analogues  description of the principles operation and
applications of analogue techniques using conducting paper the electrolyte
tank resistive networks or networks with both resistive and reactive
components
   /
5449
economic analogs  discussion of the possibilities of using analogue
computers of various types for solving problems of commerce industry
   /
5450
elements of boolean algebra for the study of information handling
systems  terminology symbols definitions and proofs of basic theorems
of boolean algebra are given as a preliminary to the use of this
algebra for studying methods of minimizing the number of physical
elements required on information handling or computing systems  the
method is illustrated by examples of design of computer circuits
   /
5451
the correlatograph  a paper tape recorder analogue device for the
continuous display of the short term correlation function by means
of a time time lag correlation factor plot intensity is described
it was designed for the analysis of signals in a magnetic tape recording
the electromechanical design is based on the af spectrograph of
   /
5452
a myriabit magnetic core matrix memory  description of an experimental
information storage system providing random access to any one of
bits in a few microseconds  the system is an extension of that previously
described by papian of  details are given of the cores which are
of ferromagnetic ceramic material and of diameter in and of the operation
of the array
   /
5453
machine aid for switching circuit design  an experimental special
purpose non numerical computer for analysis of relay circuits has
as its input a relay circuit together with the specification the
circuit is intended to satisfy  the analyser checks the circuit against
the specification makes systematic attempts to simplify the circuit
by removing redundant contacts and establishes lower limits for the
numbers and types of contact needed to satisfy the specifications
this method is compared with the method in which the same operations
are performed by coding them on a general purpose digital computer
   /
5454
the mercury delay line storage system of the ace pilot model electronic
computer
   /
5455
the magnetic amplifier as an analog computer component
   /
5456
an amfm electronic analog multiplier  a multiplier is described in
which frequency deviation and carrier amplitude are made respectively
proportional to the two quantities to be multiplied  the product
is obtained by means of a foster seeley discriminator  stabilization
is provided by means of feedback  the long term error is of full
scale output
   /
5457
electronic computers and telephone switching  a discussion of the
possibility of using digital computer techniques in automatic telephone
switching systems
   /
5458
an automatic telephone system employing magnetic drum memory  the
diad drum information assembler and dispatcher system is described
a capacitive scanner acts as a commutator for conveying signals from
subscribers sets to storage on magnetic drums  these signals are
combined with permanently stored information processed in accordance
with built in programmes and used to control call switching circuits
the technical feasibility of the system has been demonstrated by
large scale laboratory experiments
   /
5459
photographic techniques for information storage  storage devices
with capacities of bits and useful access times can be produced by
means of photographic techniques  the difficulty that rapid erasing
and rewriting are not possible with photographic media is overcome
by providing a small auxiliary unit such as a magnetic drum store
flying spot scanners can be used for reading
   /
5460
audio transformer design charts
   /
5461
the design of a peaking transformer
   /
5462
a wide band high power radio frequency transformer  detailed description
of a transformer forming part of the rf system of the birmingham
synchrotron of  it is designed for operation from a push pull amplifier
and will deliver throughout the frequency range with a duty cycle
of sec in every sec
   /
5463
a crystal triode push pull amplifier  the amplifier described uses
two point contact transistors and is capable of delivery up to output
power at an efficiency of  a power gain of at harmonic distortion
is obtained
   /
5464
kerosene cooled transistors  the temperature rise in the contact
regions of a point contact transistor is considerably reduced by
circulating kerosene around the junctions circulation is maintained
by the natural convection currents set up
   /
5465
the design of high q iron cored inductors  design charts are presented
for inductors not carrying dc the attainment of maximum q requires
the reduction of overall losses including those due to core magnetization
to a minimum  for data on inductors carrying dc see of
   /
5466
the study of a magnetic inverter for amplification of low input power
dc signals  the principle of operation of the magnetic inverter differs
from the conventional magnetic amplifier in that the load current
corresponds to the even harmonic mmfs present in the asymmetrically
excited iron core system  power gains up to can be obtained with
time constants of about sec when operating at the zero stability
is within
   /
5467
semiconductor diode gates  the general properties of gate circuits
are discussed and a simple design analysis of transmission type and
switching type gates is given  the results of an experimental check
are noted and the suitability of point contact and junction type
rectifiers for different purposes is discussed
   /
5468
study and evaluation of the microphony due to vibration of the plates
of a variable capacitor  capacitance variations due to vibrations
are investigated by observing the results distortion the latter being
evaluated from the ratio between the third harmonic and the fundamental
when a signal of amplitude about is applied  this ratio is expressed
as a function of the q of the measuring circuit details of which
have been given previously of and  the effect of variations of supply
voltage is shown in curves
   /
5469
the the fundamental theorem of electrical networks  a fuller proof
is given than that presented in the original paper of
   /
5470
application of complex symbolism to linear variable networks  the
theory developed is based on frequency domain analysis  equations
are derived for networks containing one linear variable element the
value of which varies periodically and is capable of being developed
in a fourier series  the usefulness of these equations for computations
of magnetic and dielectric modulators and amplifiers is indicated
   /
5471
the utilization of degenerate modes in a spherical cavity  formulae
are derived for calculating the coupling coefficients between an
arbitrary number of modes excited simultaneously in a cavity resonator
the perfect symmetry of the sphere gives rise to a high degree of
degeneracy ie many independent field configurations with the same
natural frequency  experiments on a spherical cavity gave results
in good agreement with the theory  practical coupling devices discussed
include irises loops and small volumes of conductor placed within
the cavity
   /
5472
microwave cavity resonators  some perturbation effects and their
applications  first order perturbation theory is used to examine
the change in resonance frequency and q of a cavity due to a small
deformation of the wall  an expression is derived for the coupling
coefficient between the two degenerate modes h and e in the absence
of perturbation these two modes can co exist  applications of the
theory to measurements of dielectric properties study of ferromagnetic
resonance etc are described
   /
5473
simplification of the tensor analysis of networks
   /
5474
power and efficiency of passive quadripoles  families of circle diagrams
are used to study the output power efficiency insertion loss and
attenuation of quadripoles
   /
5475
investigation of nonreciprocal quadripoles in the centimetre wave
range  devices based on the faraday rotation of guided waves are
investigated see eg of a method is developed for determining the
quadripole parameters of these devices  a waveguide arrangement adapted
for measurements on gyrators is described results are given for a
gyrator using ferroxcube iv  factors to be considered in designing
gyrators for particular applications are indicated  see also of
   /
5476
the design of zig zag filters  formulae are derived for the computation
of a filter with a known distribution of cut off and peak attenuation
frequencies and given image impedances  the matching conditions between
the sections and the method of determining the order of sections
in a ladder network by means of a zig zag diagram is explr design
is given
   /
5477
old and new methods for designing composite high frequency filter
circuits and their application to filter circuits with low relative
bandwidth  a calculation based on that given by edelmann for tchebycheff
type filters is used to extend schienemanns formulae for multistage
filters of to the case of finite ripples of the response curve  for
low relative bandwidths simple formulae are derived for the form
factors and time constants of the double circuit stages  as the ripples
tend to zero further simplifications can be introduced  modification
of the method is indicated to deal with cases where large ripples
are permitted for the sake of selectivity
   /
5478
practical calculation of jacobis sn elliptic function with special
reference to the determination of the cauer parameter for filters
with operative attenuation characteristics  elliptic functions encountered
in calculations of tchebycheff type filters are considered  the
method of deriving these functions and hence the attenuation frequency
curve is shown in detail for the case of an antimetrical low pass
filter  formulae for calculating the functions are tabulated in an
appendix
   /
5479
quartz crystals for filters  outline account of the characteristics
of crystals and their use in filter networks
   /
5480
electrical high frequency separating filter networks  frequency separating
diplexer and notch diplexer networks are described  two classes
of frequency separating networks are distinguished networks with
series tuned circuits in parallel and parallel tuned circuits in
series parallel parallel and series series tuned circuit networks
the former are of the frequency rejector type the latter of the frequency
acceptor type  the application of theory is shown in several numerical
examples of design of transmitter hf separating filter networks
the results are compared with the observed characteristics
   /
5481
the necessary and sufficient conditions for the physical relizability
of a rank field impedance admittance matrix in the form of a passive
multipole  it is proved that every positive real matrix of rank where
m is a finite integral number can be physically realized in the form
of a passive multipole
   /
5482
a critical review of researches into millimetric wave spark generators
methods using cylindrical and spherical electrodes and arrays of
these are discussed other methods are mentioned  difficulties involved
are indicated  references
   /
5483
magnetic control of the frequency of valve transmitters by means
of an electrodeless gas discharge  the tuned circuit inductor of
an oscillator was wound round an argon filled spherical container
in which an electrodeless discharge could be maintained and a magnetic
field was applied parallel to the plane of the coil  the oscillator
frequency was found to vary almost linearly over a certain range
of field strengths and was also dependent on the gas pressure in
the discharge vessel
   /
5484
bridge stabilized ultrasonic oscillator  good frequency stability
and low harmonic distortion are obtained by arranging a wienbridge
rc oscillator so that no arm of the bridge is hunted by a low impedance
an oscillator with five overlapping ranges covering is described
   /
5485
frequency stability and accuracy of a crystal oscillator  properties
of crystals relevant to their use for frequency stabilization are
reviewed  the occurrence and elimination of crystal oscillations
at undesired frequencies are discussed  among the factors causing
deviation of frequency from the nominal value the most important
is the circuit arrangement the requirements for satisfactory crystal
oscillator circuits are examined in detail  a table indicates the
frequency range maximum instability maximum inaccuracy maximum total
frequency deviation and energy output of some known circuits
   /
5486
frequency stabilization of a reflex klystron oscillator  part of
the klystron output is fed to a cylindrical resonator one of whose
ends is constituted by a diaphragm which is vibrated at about kcs
the detected output from the resonator which varies with shift of
the klystron frequency is fed to a lock in amplifier to produce a
control voltage which is added to the klystron reflector voltage
   /
5487
the miller integrator as sawtooth voltage generator  the theory of
the miller integrator is discussed and practical circuits of the
transitron and practical circuits of the transitron and sanatron
an integrator with separate controlling valnent values is considered
in detail
   /
5488
the parallel tdc amplifier a low drift amplifier with wide frequency
response  discussion on of  please note change in udc number
   /
5489
a transistor pulse amplifier using external regenerated pulses having
desired waveforms as required in synchronous serial computers are
obtained by means of a circuit using a point contact transistor operated
as an over driven amplifier with external feedback  provision is
made for synchronizing the output pulses with a master clock  transformer
coupling provides dc restoration
   /
5490
neutralizing pentodes in radar if stages  the effects of grid plate
capacitance are cancelled without use of additional components tapped
coils or balanced tuned circuits by using as neutralizing capacitor
a screen bypassing capacitor providing slightly less than complete
bypassing  experimental methods are described for determining the
required values of the neutralizing capacitors for radar and television
if amplifiers
   /
5491
the magnetic amplifier  comparison of the elementary magnetic amplifier
with the type using external feedback
   /
5492
design of magnetic amplifiers  an outline of basic design principles
   /
5493
nonlinear capacitors for dielectric amplifiers  the operation of
the dielectric amplifier depends on the vas on the variation of dielectric
constant with applied voltage  requirements for materials suitable
for high frequency small signal applications are discussed  a two
stage amplifier with rf power supply ad and gain of is briefly described
   /
5494
new constructional techniques  survey of modern methods for producing
radio equipment including potting circuit printing and automatic
soldering
   /
5495
radio research special report fundamental processes of electrical
contact phenomena
   /
5496
on interaction of nonlinear oscillations  general considerations
regarding the existence stability and certain topological rules of
selection between several oscillations are outlined  the results
are used to investigate the differential equation using the stroboscopic
method of  some special cases are examined
   /
5497
the photoeffect in a uniform electric field  it is shown theoretically
that even very high external fields have little effect on the angular
distribution of the photoelectrons or on the total effective atomic
cross section
   /
5498
free electron in an e and h field  the general equations of motion
are obtained for an electron in electric and magnetic fields  particular
cases for various angles between the field and velocity vectors are
considered
   /
5499
experimental studies of the motions of slow electrons in air with
application to the ionosphere  from experiments on the motion of
slow electrons in air empirical formulae were deduced from which
the electronic temperature collision frequency drift velocity and
the average energy loss per collision ca can be derived  the collision
cross section of molecules of air and nitrogen at electron temperatures
up to is directly proportional to the speed of the electrons  the
electron collision frequency in the ionosphere up to is linearly
proportional to the pressure  the important result that is proportional
to and not to as believed hitherto where q is the agitational energy
of the electron and q the energy of thermal agitation of the gas
molecule is discussed briefly
   /
5500
the case of charged density distribution versus semipermanent polarization
as a basis for electret behavior  it is shown that if an electret
were composed of ordinary charge distributions its effects would
diminish by in a day or two the observed effects indicate the existence
of a semi permanent polarization and can be regarded as arising from
a lag in the cancelling action of conductivity
   /
5501
investigation of the interaction between an electron and a lattice
oscillator by means of a one dimensional model
   /
5502
the dielectric properties of water in solutions  measurements have
been made of the microwave dielectric constants and losses of water
and some aqueous solutions over the temperature range using methods
described by collie et al  the dielectric constant of water at cm
rises from at to at  results for the solutions are tabulated and
their interpretation is discussed
   /
5503
the linear piezoelectric equations of state  the different forms
of the equations of state obtained from various combinations of stress
strain electric field electric displacement and polarization are
given in tabular form
   /
5504
electro thermal behaviour of point contacts to semiconductors  joule
heating effects due to current flow through a point contact to a
semiconductor with no barrier layer were investigated theoretically
and the results were confirmed experimentally for tungsten points
in contact with sintered disks of mg ti  the values of the contact
radius calculated from dc and ac experiments are in fair agreement
as are the calculated and measured variations with frequency of the
impedance to sinusoidal ripple superimposed on steady current  minor
anomalies in the dc characteristic are assumed to be due to field
emission around the contact
   /
5505
the ignition voltage of gas discharges in a transverse magnetic field
over the pressure range torr  experiments were made using a discharge
space bounded by coaxial cylinders with a coaxial magnetic field
a voltage of was sufficient to start a discharge at torr with a suitable
magnetic field strength  on the basis of these measurements and those
of other workers expressions are derived relating ignition voltage
to magnetic field strength electrode separation and configuration
electrode material nature and pressure of the gas  above a critical
value of torr cm for air the magnetic field raises the ignition voltage
below this critical value the magnetic field reduces the ignition
voltage
   /
5506
the growth of the high frequency electrodeless discharge  the various
stages in the growth of electrodeless discharges are discussed in
detail with particular consideration of electron multiplication processes
increase of the number of positive ions and the effect of charges
on the wall of the discharge tube  a new experimental technique for
measuring the discharge current is described in which the large capacitive
current across the external electrodes is balanced in a bridge
circuit so that when a discharge occurs the unbalanced voltage after
amplification and rectification can be used to give a proportionate
representation of the value of the discharge current on a cro for
measurement of the growth of the current with time hf voltage pulses
are applied to the discharge tube and the timebase of the cro synchronized
with the pulses  oscillograms show how the growth of current
depends on the pressure the nature of the gas the excess voltage
and the frequency of the applied field  in the initial stage the
properties of the tube walls mainly control the multiplication process
and thus the starting field  in the later stages the properties of
the gas become important and so determine the total time of growth
of the discharge  for previous work see of
   /
5507
secondary electron emission of crystalline mgo  single crystals of
mgo in bulk form cleft along the plane were used  the maximum secondary
emission ratio is about at room temperature and with a bombarding
voltage of about  no correlation between conductivity and yield was
established  increase in temperature led to a decrease in yield
the most probable energy of emission is about  theoretical considerations
based on band theory support these observations
   /
5508
collisional effects and the conduction current iin an ionized gas
a first approximation to the transport equation for the conduction
current in a binary ionized gas id derived  the collision damping
factor derived is a weighted mean of the electron and ion collision
frequencies which is times the electron collision frequency  corresponding
approximations made to the equations of conservation motion and
thermal energy when combined with maxwells equations yield a set
of equations for the investigation of the interactions between an
ionized gas in motion and the associated radiation field  the results
are applicable to the solar atmosphere and the h h and lower ionosphere
regions
   /
5509
the magnetic fields produced by uniformly magnetized ellipsoids of
revolution  formulae graphs and tables are given for the numerical
evaluation of the field strengths in the equatorial plane and on
the magnetic axis of prolate and oblate spheroids
   /
5510
the influence of domain structure on the magnetization curves of
single crystals  neels model for the domain structure of a single
crystal of iron in the form of a strip parallel to the direction
was used in the calculation of magnetization curves depend explicitly
on the width of the crystal  comparison between the calculated curve
and experimental results for a si fe crystal shows good agreement
particularly at low field values
   /
5511
induction phenomena consequent on the movement of material in primary
magnetic fields and their experimental applications part experimental
bases  discussion of unipolar induction using this term in its broad
original meaning viz induction of electricity due to movement f of
material in a magnetic field  simple experiments demonstrating the
basic phenomena are described
   /
5512
induction in a conducting sheet by a small current carrying loop
analytical solutions are derived for the cases where the loop axis
and the plane of the conducting sheet are mutually perpendicular
parallel  the results are applicable to problems of electrical shielding
and prospecting
   /
5513
an identity leading to a solution of kirchhoffs problem for damped
waves
   /
5514
electron currents in thin oxide films on aluminium  at low electric
field intensities the electron current in films formed on al in suitable
electrolytes depends on the temperature and on the hyperbolic sine
of the product of the field strength and a constant dependent on
barrier dimensions  the oxide film barrier height and trough to peak
width are ev and respectively  the theoretical current voltage curves
given show good agreement with experimental results  the origin of
the electron current and the presence of trapped charges in the oxide
layer near the electrolyte surface are discussed
   /
5515
radio research special report fundamental processes of electrical
contact phenomena
   /
5516
conditions for the occurrence of electrical discharges in astrophysical
systems  theoretical considerations of a large ionized mass of gass
in motion show that neutral points of the magnetic field are unstable
so that a small perturbation will start a discharge  the orbits of
particles in the field are considered particles with very large energies
may be involved  such discharges may account for aurorae and may
also occur in solar flares and the interstellar gas
   /
5517
the length of ionized meteor trails  the length of the meteor ionization
column is defined as the distance between the most widely separated
points along the trail from which normal incidence radio reflections
can be obtained using a radar system of prescribed characteristics
a statistical study is made of the length distribution of trails
based on measurements made at two observation stations a spaced km
apart and operating with a cw output power of about on  the mean
trail length found was meteors up to the sixth magnitude were detected
   /
5518
cosmic origin of radiation at radio frequencies  discussion of possible
ways in which rf radiation from stellar sources may be produced
   /
5519
some fundamental results and problems of radio astronomy  a clear
and concise survey of measurement techniques is given together with
a discussion of the theories of the origin of rf radiation from the
sun and the radio stars  the results measurements of the line emission
of interstellar hydrogen on a wavelength of cm are briefly discussed
in relation to the problem of the structure of the milky way
   /
5520
collisional effects and the conduction current in an ionized gas
   /
5521
note on a proposed three component aeromagnetometer  by identifying
stairs photographed with a small nonmagnetic camera mounted on the
fluxgate gimbal mechanism of a total force aeromagnetometer it is
possible to find the magnetic declination and dip
   /
5522
conference on radio meteorology  summaries are given of paper for
presentation at the conference at the university of texas november
   /
5523
exploring the ionosphere by means of rockets  summaries are given
of papers presented at a conference held at oxford under the auspices
of the royal society
   /
5524
the charge on the ionosphere  the total charge on the inner side
of the ionosphere is shown to be zero
   /
5525
study of the ionospheric d region using partial reflections  pulse
echo observations were made with a transmitter of peak power and
with the receiver located where the noise level was very low  results
showed that below the e layer there were two reflection regions a
region of greater electron density around extending up to the normal
e layer and having minimum ionization at noon a region around km
where a distinct ionized layer forms during the day attains a maximum
ionization at noon and disappears at night  in echoes from this region
both magneto ionic components were present the extraordinary being
the stronger  the ratio of the two magneto ionic components of a
discrete echo at a particular range was within the uncertainty of
observation independent of fading but varied with time of day and
from day to day  from this ratio the collision frequency and electron
density for this range of heights were determined
   /
5526
two cases of large f region disturbance associated with small magnetic
disturbance  during oct  at canberra and brisbane and to a lesser
extent at other places in this area of the world hourly values of
and showed departures from monthly median values typical of those
observed during a considerable magnetic storm  the days in question
were international quiet days  two other though less striking cases
have been found from analysis of the records
   /
5527
the distribution of f region ionization at high latitudes  the linear
relation between critical frequency and sunspot number is found to
hold with reasonable accuracy in the arctic  contour charts of a
and b have been prepared in coordinates of latitude and longitude
for fixed hours and months  typical examples are shown and the general
features particularly the effects of the auroral zone and geographical
factors are pointed out
   /
5528
some statistical results on the phenomena associated with ionospheric
storms  data covering the years on height of maximum ionization o
of the f layer and absorption in lower layers were analysed to determine
the probability that a particular day will be a storm day for a given
set of solar conditions  a day is considered to b be a storm day
if the mean variation of these three parameters studied separately
in relation to the effects of sunspots m regions and solar flares
is such as would cause a fall in muf or a rise in luf  positive results
were obtained only for the parameter f  except for storms associated
with m regions at sunspot minimum the probability that a given day
will be a storm day does not exceed for the first day of a storm
but many reach on subsequent days  it is concluded that only during
the sunspot minimum period can ionospheric storms be forecast on
solar data alone
   /
5529
the ionosphere during the partial solar eclipse observed at buenos
aires august  the decrease in in the number of free electrons in
the f layer during the eclipse was mainly due to ion recombinations
a simultaneous decrease in the f layer was preceded by an appreciable
increase  the two layers were clearly separated indicating a high
recombination coefficient above the f layer  rapid decrease of the
critical frequencies of both layers was observed during the occultation
of two sunspots
   /
5530
experimental studies of the motions of slow electrons in air with
application to the ionosphere
   /
5531
typical scattering of radio waves by electron clouds in the sporadic
e layer  the three main types of scattering deduced by eckersley
of from fixed frequency observations are confirmed by specially selected
records of swept frequency echo soundings made at lindau
   /
5532
the relation between rain current and rate of rainfall  consideration
of the drop size distribution in rain leads to a relation very similar
to the first of simpsons formulae
   /
5533
the effective separation of discharging points  the effective separation
ie that spacing of points in rectangular array which would give the
same current density as actually occurs with an earth connected point
in discharges o of atmospheric electricity is m for high field strength
   /
5534
the aurorae  general characteristics of aurorae are described and
the connection between aurorae and both solar activity and geomagnetism
is shown and  the auroral spectrum is discussed and various theories
of the aurora are critically reviewed
   /
5535
an investigation of whistling atmospherics  a comprehensive report
of an experimental and theoretical study of whistling atmospherics
at frequencies is given  whistlers may or may not be preceded by
ordinary atmospherics produced by lightning strokes at a distance
of km  the diurnal and annual variations of th the properties of
both types were investigated  explanatory theory of their origin
advanced by eckersley of is developed  measurements of the degree
of dispersion indicate an electron density in the upper atmosphere
considerably larger than expected  this result is explained on the
assumption that electrons are falling in from outside and this might
account for the relation between the occurrence of whistlers and
magnetic activity
   /
5536
design methods for control systems  the nyquist diagram method of
analysing feedback systems is discussed stability problems can be
simplified by using a method based on the attenuation frequency characteristics
the speed control of a dc motor is considered as an example
   /
5537
fast response high current thyratron power supplies for inductive
loads  several methods for energizing loads such as fields of large
motor generators solenoids magnetic clutches and electromagnets are
discussed including the half wave circuit with an optimum value of
capacitance in parallel with the load  this method provides the fastest
response for the equipment required
   /
5538
standby generating plant for the manchester edinbugh television radio
relay link  description of equipment driven by an ic engine which
automatically restores the supply voltage at unattended relay stations
in case of mains failure for more than two seconds  the sets are
given daily test runs remotely controlled from attended stations
   /
5539
electric batteries recent patents  discussion of improvements in
leclanche type cells alkaline batteries cells with dished plates
or with bipolar electrodes hgo cells and weston standard cells
   /
5540
application factors for electrical resolvers  the device described
resembles a small motor and was originally designed for solving a
trigonometry problems in conjunction with analogue computers  possible
applications for control purposes in industry are discussed
   /
5541
magnetic drum design  a chart relates the various parameters involved
   /
5542
step switch converter digitizes analog data
   /
5543
review of new materials and techniques in high fidelity transformer
design
   /
5544
transistors theory and application part grounded emitter and collector
circuits  formulae and typical values of parameters are tabulated
for various circuit arrangements for junction and point contact transistors
part of january
   /
5545
transient analysis of transistor amplifiers
   /
5546
the electrical conductivity and current noise of carbon resistors
the variation of resistance with temperature pressure and magnetic
field in several types of carbon resistor was measured down to liquid
he temperatures  the dependence of the noise spectrum on the current
intensity temperature and magnetic field was also investigated the
law holds at all temperatures
   /
5547
basic fuse types for electronic equipment  types with slow medium
and fast action are described
   /
5548
tolerances and temperature coefficient of coils with ferroxcube slugs
extension of a previous discussion of  from the point of view of
insensitivity to variations of core permeability and of temperature
the closed core with air gap is best the rod core with long coil
next and the rod core worst  see also of
   /
5549
a variable inductor  an af inductor is described in which core hysteresis
effects are eliminated the inductance being controlled by moving
a magnet in relation to the cores  q values at and at are possible
experimental filters using the inductors are also described
   /
5550
current trends in miniature relay design  design of relays for airborne
electronic equipment is discussed
   /
5551
the optimum dc design of flip flops  a simple criterion is derived
by means of which it can immediately be seen whether or not a flip
flop circuit corresponding to specified requirements is realizable
a numerical example is given
   /
5552
the eit decade counter tube
   /
5553
polycathode counter tube applications  the use of dekatrons in millisecond
timers batching counters and cro time markers is described  the
basic decade units are capable of counting up to per sec  see also
   /
5554
a method of approximate steady state analysis for non linear networks
approximate solutions for the fundamental and third harmonic are
obtained by a three stage method involving a first approximation
to the fundamental frequency solution usually accurate to within
a third harmonic solution generally within using an equivalent circuit
which is dependent on the first fundamental solution a correction
to the fundamental solution using third harmonic quantities which
brings its accuracy to within about  adaptations of some standard
techniques of solving linear steady state problems for use with this
method of analysis are described  appendix by gh rawcliffe
   /
5555
effective circuit bandwidth for noise with a power law spectrum
analysis is developed for a tuned rlc circuit for noise with a frequency
spectrum given by an arbitrary power law  the effective bandwidth
is presented in terms of that for white noise
   /
5556
the piezoelectric oscillations of a quartz crystal at its odd even
and half odd harmonics  the results reported in were confirmed by
observing the diffraction patterns of the oscillating quartz
   /
5557
flexure mode quartz oscillators  details are given of the modes of
motion electrode arrangements and electrical performance of the duplex
xy and nt types  typical frequency temperature curves and graphs
of other crystal characteristics are shown  a crystal controlled
af oscillator is described and the circuit diagram including component
values is given
   /
5558
loci curve theory applied to high frequency networks  the application
of the method is shown for the evaluation of such response curves
of four terminal networks as are produced by the variation of one
parameter  examples are given of the calculation of a wide band thermistor
mount using a rectangular admittance chart and the variation
of the input reflection coefficient with frequency of a given transformer
using a smith chart
   /
5559
antenna matching network efficiency  charts are presented for estimating
the transfer efficiency of matching networks
   /
5560
conformal mappings for filter transfer function synthesis  conformal
mapping provides a practical way of solving the es potential problems
previously considered of  analysis in the mapped plane also yields
convenient methods for predetermining the number of poles and zeros
required to meet given design specifications
   /
5561
theory of maximally flat and quasi tchebycheff filters  the synthesis
of a quadripole with a prescribed attenuation function is described
this function has to satisfy certain conditions  the synthesis s
is carried out for maximally flat and quasi tchebycheff low pass
filters the results being presented in curves suitable for calculating
the values of the circuit components  the treatment is extended to
band pass filters by means of a well known frequency transformation
   /
5562
rlc lattice networks  correction to paper noted
   /
5563
band pass filters  a method is presented for synthesizing constant
resistance networks to have maximally flat or tchebycheff type response
characteristics  a numerical example of each type is calculated
   /
5564
high frequency filter problems in television transmitters  coaxial
line filters for the partial suppression of the lower sideband are
discussed  particular attention is paid to arrangements suitable
for high level modulation in which the filter is spatially separated
from the output stage and its input impedance is maintained constant
over the frequency band
   /
5565
electrical control of valve transmitter frequency by means of an
electrodeless gas discharge  the tuned circuit inductor of an oscillator
was wound round an argon filled cylindrical container in which an
electrodeless discharge could be mained  the oscillator frequency
was nearly linearly proportional to the anode voltage and was also
dependent on the gas pressure  see also
   /
5566
noise properties of lc oscillators  previous analyses based on the
concepts of forced oscillations and disturbed free oscillations of
are discussed the extent of the am and the fm resulting from the
presence of noise is examined
   /
5567
pseudoresonant and phase shifting quadripoles as frequency determining
elements in rc oscillators  rc oscillators with a sinusoidal output
are divided into two main groups according to the type of rc network
they include  equivalent circuits are obtained and simple expressions
are derived for the frequency of stable oscillation and for the condition
for self excitation
   /
5568
theory of triode oscillators with coaxial resonators  a study of
disk seal triode oscillators  the conditions necessary for maintaining
oscillations are derived  the width of the frequency range with a
fixed tuned grid circuit is calculated from the valve parameters
deviations from the theoretical value encountered under working conditions
are discussed  a general criterion for mode separation is established
   /
5569
pulse generator with variable repetition frequency and pulse width
an instrument designed around the eq nonode valve is described the
principle of operation is that of the detector of  the pulse repetition
frequency can be varied between and or higher the duty factor from
to and the amplitude from to  the pulse flank occupies of the pulse
period  pam pwm and pphm can be used  a complete circuit diagram
including component values is given
   /
5570
wide band amplifiers using secondary emission tubes  the applications
of an experimental valve particularly at vhf in rf or if amplifiers
cr tube deflection amplifiers and distributed amplifiers are described
and discussed  the transconductance of this valve is the input and
output capacitances are and respectively and the sum of anode and
screen currents is ma  the valve construction has been described
by mueller
   /
5571
a method for the amplification of extremely small thermoelectric
voltages  a more detailed account of the dc amplifier noted in of
is given  the threshold voltage is with a source impedance of  a
circuit diagram including component values is given
   /
5572
noise factor of conventional vhf amplifiers  a simple treatment is
presented the various types of circuit and valve noise are indicated
the concept of available power is explained and noise factor is efined
in terms of available power gain  analysis is given for triode input
stages based on common cathode common grid and common anode connections
experimental results are given for various amplifiers for a mid band
frequency of  curves show the effect of source resistance on the
midband noise factor and the variation of single frequency noise
factor over the band and results are also tabulated for different
valves and circuits  the best noise factor with a given valve can
only be determined experimentally  the need for further improvement
in the noise performance of valves is emphasized
   /
5573
multiple feedback audio amplifier  the power output of the williamson
circuit is increased and the power supply requirements reduced by
using tetrode output valves with anode to grid feedback
   /
5574
stability of a grounded grid amplifier  the general conditions are
investigated for the self excitation of uhf grounded grid amplifiers
the precise formula and an approximate one for the frequency and
the condition for self excitation are derived  the dependence of
the stability of the amplifier on circuit constants is considered
the results are shown graphically
   /
5575
methods of magnetic amplifier analysis
   /
5576
pcm coding system uses special tubes  the system uses a ten target
ribbon beam switching tube for sampling and a tube with ten stable
positions determined by crossed electric and magnetic fields for
coding  descriptions of tubes and circuit are given
   /
5577
printed circuits some general principles and applications of the
foil technique  methods of producing printed circuits are discussed
from the viewpoint of the printer the foil technique is suitable
for both general and special applications  the main processes involved
namely printing etching fusing mechanical patterning transfer and
multilayer technique are described  various characteristics of foil
conductors are examined and some particular applications are indicated
   /
5578
johnson noise and equipartition
   /
5579
the value of the constant in wiens displacement law  the observed
value of the wavelength at which maximum radiation occurs for a black
body at a given temperature depends on the band pass characteristics
of the instrument used as a consequence wiens constant can assume
different values
   /
5580
demonstration of electroluminescence by means of a multilayer colour
film  contact photographs were made of electroluminescence effects
in a phosphor at field strengths of and a frequency of  the results
indicate a direct excitation process without the intermediate step
of a gas discharge
   /
5581
the diffraction of an arbitrary pulse by a wedge  an extension of
the conical flow method used by keller and blank  the coordinates
chosen are such that the characteristic cone and the two planes intersecting
to form the wedge each become constant coordinate surfaces
the problem is then solved by separating variables and expanding
the boundary conditions in terms of solutions of the ordinary differential
equations which appear  the results are shown to apply to the
special case investigated by keller and blank
   /
5582
theory of diffraction of electromagnetic waves at a perfectly conducting
disk and related problems  the problem considered in of for plane
em waves is solved generally for the case of spherical waves  particular
solutions are also obtained for the diffraction at an ellipsoid of
revolution for a solenoidal em field  a method for the numerical
solution is outlined for the case of diffraction at a disk at a circular
aperture and at an ellipsoid of revolution valid for approximately
where as is the radius or half the distance between the foci as appropriate
   /
5583
scattering of electromagnetic waves at an uneven surface  scattering
of waves incident at an angle such that no part of the surface is
in a shadow is considered theoretically  application of the results
to two particular cases shows that surfaces of a trochoidal form
will give appreciably greater backscatter than a sinusoidal surface
of the same amplitude and wavelength
   /
5584
the theory of electronic conduction in polar semiconductors  the
present problem has been considered before by several authors but
many of the results which have been given are either incorrect within
certain limits  by solving the boltzmann equation for the velocity
distribution function of the conduction electrons in a crystal in
which the scattering is due to the polarization waves of the lattice
exact expressions are obtained for the electrical conductivity and
the thermoelectric power in the form of ratios of infinite determinants
simple approximate solutions are derived and are used in the discussion
of the dependence of conduction phenomena upon the temperature and
upon the degree of degeneracy of the electron gas
   /
5585
the transient period of the skin effect  analysis is given for the
distribution of current in cylindrical conductors solid or hollow
during the period between application of a voltage and attachment
of a steady state
   /
5586
impedance of solid and hollow cylindrical conductors to current pulses
continuation of work noted in above  a quantitative solution is obtained
for the initial value of the ratio between the instantaneous voltage
and current
   /
5587
electrical discharges  recent work on electrical discharges is surveyed
under the following headings the breakdown of gases in static fields
high frequency discharges cold emission phenomena the regime of space
charges  breakdown is regarded as a consequence of the development
of pre breakdown ionization currents by primary and secondary processes
which are themselves controlled by the nature and geometry of the
cathode  the important part played by surface films in the cold extraction
of electrons from electrodes is described  rf plasma oscillations
and the generation of noise by discharges is discussed
   /
5588
fundamental processes of the initiation of electrical discharges
the production of electrons initiating the spark discharge from polished
and tarnished metal surfaces was investigated  the field applied
was of the order of
   /
5589
electron emission resulting from the impact of ions on molybdenum
and carbon targets  experiments were made using normally incident
polyatomic ions of energy between and  the number and energy distribution
of the emitted electrons did not depend on the target material
the energy distribution of the electrons was independent of the nature
and energy of the incident ions but the number of electrons emitted
per ion increased with the energy of the ions and depended on the
nature of the ions
   /
5590
a variational formulation of the multi stream electro dynamic field
equations  a non relativistic approximation to diracs new variational
formulation of the single stream electrodynamic field equations is
presented using vector notation and mks units throughout  the hamilton
jacobi theory of a rotational space charge stream is developed  the
variational formulation is generalized to the multi stream case both
for a finite number and a non denumerably infinite number of streams
   /
5591
induction phenomena consequent on the movement of material in primary
magnetic fields and their experimental applications part translation
the minkowski field equations are presented in a form to suit the
particular conditions  a definition is given of apparent dielectric
constant  sommerfields treatment of unipolar induction is extended
to magnetizable bodies  unipolar induction in the case of translational
motion is identified with es induction in the material at rest
   /
5592
the hissing arc and radio frequency self generated oscillations in
the dc carbon arc
   /
5593
radio astronomy part methods of observation  theory and technique
of methods of observing extraterrestrial sources of rf radiation
are reviewed
   /
5594
evidence of harmonics in the spectrum of a solar radio outburst
measurements of rf outbursts on november and may show a dynamic spectrum
comprising two widely spaced frequency bands having a drift with
time from high to low frequencies  the ratio between frequencies
of corresponding peaks was close enough to to suggest a harmonic
relation between the bands  the emission may take place in the corona
at frequencies equal to the natural plasma frequency and its harmonics
   /
5595
radio observations at the time of an ascending solar prominence
the solar prominence reported by das and sethumadhavan below was
observed in sydney and records of radiation on and were obtained
noise bursts preceding and following the eruption were also recorded
   /
5596
eruptive prominence of february and associated radio noise burst
three bursts of noise associated with the prominence were recorded
at kodaikanal with a radio telescope working on  these occurred when
the topmost parts of the prominence were at about and respectively
above the limb though present day theory indicates that at radiation
cannot ordinarily escape from the sun unless generated at a height
km  no active sunspot group was observed in the vicinity of the prominence
   /
5597
radio radiation from the supergalaxy  a low intensity source was
observed in march on with position corresponding approximately to
the plane of the local supergalaxy described by de vaucouleurs
   /
5598
the galaxy explored by radio waves  the full text of the halley lecture
for  this includes a short account of radio astronomy n and of the
results of observations made at cm and other wavelengths
   /
5599
a search for radio emission from the orion nebula  short report of
interferometer observations at a frequency of
   /
5600
a model of the radio frequency radiation from the galaxy  the model
has been designed to give agreement both with the observed values
of equivalent aerial temperature and with the observed isophotes
over the frequency range  the actual mechanism of generation of radio
energy is not discussed
   /
5601
the distribution of the discrete sources of cosmic radio radiation
   /
5602
the south magnetic pole in and the comparative displacements of the
north and south poles from to
   /
5603
recording the geomagnetic field at port martin  the records were
obtained by the adelie land expedition during the period january
details are given of methods and results
   /
5604
electromagnetic variometer for the vertical component of the geomagnetic
field  an instrument is described it operates on the same principles
as the electromagnetic seismograph
   /
5605
further determinations of the vertical distribution of ozone during
eclipses of the moon
   /
5606
propagation measurements in the ionosphere with the aid of rockets
measurements made at white sands are reported  continuous waves with
harmonically related frequencies namely and were radiated from the
rocket to two ground stations  the higher frequency wave is practically
unaffected by the e layer and serves as a reference  the ordinary
and extraordinary components of the lower frequency wave with frequency
multiplied by re separately heterodyned with the reference wave  the
refractive indices of the medium are determined from the resulting
beat frequencies together with a determination of the geomagnetic
field and of the electron collision frequency at one altitude the
lorentz polarization term can be neglected  results are given and
discussed
   /
5607
the reflection coefficient of the long wave  the propagation equation
is solved and the reflection coefficient deduced for long waves incident
vertically on a region of low electron concentration such as that
situ ted below the e layer  results are given for two cases based
on different assumptions regarding the vertical gradient of concentration
comparison of these calculated results with observations on and
waves indicates that there is a considerable gradient of electron
concentration in the layer
   /
5608
dissociative recombination in the e layer  an examination is made
of the consequences of assuming that electrons in the e layer disappear
mainly by dissociative recombination  it is shown that this assumption
provides a far more satisfactory basis for explaining actual e layer
observtions than ion ion recombination and that most of the atomic
processes involved are amenable to accurate laboratory measurement
   /
5609
ionosphere observations in the kerguelen isl nds  an ionosphere station
has been established by the spim at port aux francais regular observations
started in february  monthly mean values of and for six months
are tabulated the results demonstrate the great influence of the
geomagnetic field
   /
5610
some regularities of the ionospheric f region  the f layer regularities
observed by ratcliffe are confined to a few stations only and disappear
when the bifurcation of the f layer is large if the ion content of
the f a and f layers is considered as a whole the regularities become
much more marked n and are observed at slough falkland islands and
singapore even when the bifurcation is large  peaks observed in the
monthly mean values are attributed to tidal effects  the results
are in conformity with the view that the f and f layers constitute
a single ionization region
   /
5611
lunar tidal variations in the sporadic e region  lunar tidal variations
in the e layer are deduced from a statistical study of records from
various stations  the maximum amplitude of the lunar semidiurnal
variation of e for a period of a year resembles that of the f layer
in summer it is larger than that of the f layer especially in middle
latitudes  the magnitude of the height variation is similar to that
of the f layer  the maximum height variation occurs about six hours
after the lunar culminations and the maximum value of e two or three
hours later  possible explanations of the phenomena are discussed
   /
5612
the distribution of the ionospheric disturbances during the geomagnetic
bay  a statistical analysis based on ionospheric data obtained at
widely distributed stations
   /
5613
on a change in geomagnetic declination accompanying intense sporadic
e layer ionization  analysis of geomagnetic and ionospheric data
obtained at kakioka and kokubunji respectively indicate that the
geomagnetic declination exhibits increased diurnal variation a few
hours after the appearance of an intense e layer  it is inferred
that the e layer ionization is probably due to the incidence of particles
   /
5614
a procedure for the determination of the vertical distribution of
the electron density in the ionosphere  see also
   /
5615
optic axes and critical coupling in the ionosphere  the similarity
between the phenomena of double refraction in crystals and in the
ionosphere is discussed  the ionosphere problem is studied by introducing
a reference system based on the principal directions of the three
dimensional dielectric ellipsoid these depend only on the direction
of the earths field and are essentially constant over the ionosphere
optic axes can exist in the ionosphere in the presence of collisions
and this is precisely the condition for critical coupling between
the ordinary and extraordinary modes  the analysis is illustrated
by reference to a possible set of ionospheric conditions
   /
5616
raindrop charge and electric field in active thunderstorms  measurements
on over drops are reported the average charge was esu for positively
charged drops and esu for negatively charged drops
   /
5617
on the electrification of snow  an account is given of experimental
investigations of the charging produced by pouring snow from a vessel
into a funnel and blowing snow on to an insulated target  the results
are relevant to problems of precipitation static
   /
5618
radar echoes from a growing thunderstorm  the growth of hail in cumulus
clouds is studied theoretically in relation to the first appearance
of radar echoes  the results are in good agreement with earlier observations
   /
5619
auroral radio echo table and diagram for a station in geomagnetic
latitude
   /
5620
radio noise from aurora  failure of attempts made during and to detect
cm auroral radiation observed in is attributed to the decreased intensity
of auroral displays and of sunspot activity
   /
5621
electrical properties of the blizzard  the programme of the expedition
to adelie land was not intended to cover the study of blizzards but
the interference with radio reception due to this cause was found
to be so bad that an investigation was instituted  when a meter was
connected between the aerial feeder of the atmospherics receiver
and earth a current of was observed varying with the intensity of
the wind some days later in identical weather conditions the same
current intensities were measured but with reversed sign  to explain
this result extended measurements were made of the charge collected
using horizontal aerials arranged at right angles to the wind the
rf noise spectrum of the blizzard was also studied using a receiver
with a frequency range of  records were also made of reception of
wwv and wwvh on and for correlation with anemometer and charge records
the results indicate that the sign of the charge collected depends
on the temperature of the blizzard reversal occurring at about  the
rf noise is closely related to the wind and intensity of the blizzard
   /
5622
audio frequency spectrum of atmospherics  results are reported of
simultaneous recordings of the frequency components in the band
the frequency of the largest component in the slow tail decreases
as source distance increases and is higher at night than by day while
for the oscillator part the opposite effect occurs  selective attenuation
at frequencies around is indicated
   /
5623
the variation with distance in the range km of atmospheric waveforms
records of the electric field variation of a violent thunderstorm
made at distances of are analysed over portion which cov large and
rapid increase in field strength corresponding t to the return stroke
of the lightning discharge  theoretical and experimental results
for the waveform the ratio of the maximum es field to the net es
change and the current in the discharge are in fair agreement
   /
5624
die ionosphere  intended primarily for the physicist who wishes to
make a rapid survey of ionospheric physics space has been found in
most cases not only for a brief review of the background but also
for an indication of more recent developments
   /
5625
design charges for an on off control system  discussion  a simple
and rapid method is presented for determining the step function response
of an off system consisting of a pure time delay or distance velocity
lag an exponential time constant and an integration
   /
5626
self excited two phase thyratron inverter  details are given of a
unit providing an output of at from a input
   /
5627
programme design for the csiro mark computer computer conventions
   /
5628
programme design for the csiro mark computer programme techniques
   /
5629
recent electronic computers and their applications  digital computers
are described and compared in respect of operating and speed and
structure
   /
5630
a mathematical basis for an error analysis of differential analysers
   /
5631
analogue computer for aircraft design  a compact general purpose
instrument designed for economical quantity production
   /
5632
an analog to digital converter  a device for giving the angular position
of a slowly rotating shaft as a binary number uses a mechanical counter
which goes from zero to full capacity during one revolution of the
shaft  the counter may comprise a series of cams associated with
switches  on application of a reading pulse the number registered
by the counter is made available as a pattern of pulses the arrangement
being suitable as an input device for a digital computer
   /
5633
servo systems for performing mathematical operations  by combining
servomechanisms with computing systems involving mechanical or electrical
analogies loading effects which tend to introduce inaccuracies
are eliminated  an outline is given of procedures for addition and
subtraction determination of powers and roots solution of triangle
and integration
   /
5634
the univac tube program  account of an integrated programme starting
with the design and initial selection for ensuring reliable performance
of valves in a large scale computer
   /
5635
rapid parallel z calculations  use of a special graph paper with
both polar and rectangular coordinates facilitates the calculation
a ruler is the calculation  a ruler is the only instrument required
in this graphical method
   /
5636
the calculation of nonlinear networks by means of composite straight
line characteristics  many circuit problems are simplified by substituting
for an actual curved characteristic an approximation built up
of rectilinear sections  use of the method is illustrated by studying
the characteristics of iron cored coils with and without hysteresis
and with and without magnetic bias and t by analysing the free oscillations
of a circuit including an iron cored coil  emphasis is a laid
on the point that the actual shape of the nonlinear characteristic
is less significant than the simple fact of its deviation from linearity
   /
5637
harmonic and intermodulation distortion in power law devices  explicit
expressions are derived for the intermodulation components produced
when two sinusoidal voltages are applied simultaneously to a device
such as a diode whose transfer characteristic can be represented
by a simple power law formula  results of practical importance in
intermodulation distortion testing are presented graphically
   /
5638
components for severe conditions of use  a discussion of the factors
to be considered in the design of capacitors and resistors for use
under extreme temperature and humidity conditions particularly when
the components are required to be as small as possible  the use of
ceramic covered wire for the windings of transformers etc to withstand
high temperatures is mentioned
   /
5639
frequency discrimination and stabilization of square wave modulated
microwave transmissions  the method described is a modification of
that due to aurell mit technical report no  the frequency of the
oscillations from a reflex klystron is compared with the resonance
frequency of a high q cavity and a correction voltage depending on
the frequency difference is fed back to the klystron reflector electrode
via the modulator where it is combined with the square wave modulation
voltage  the method of alignment of the microwave circuits is discussed
in detail and the effect of misalignment on the discriminator characteristics
is shown
   /
5640
properties and applications of thermistors
   /
5641
theory of the boella effect  a discussion of the mechanism causing
the drop in the resistance of composition resistors at hf abstracts
a similar variation of resistance with frequency has been observed
in electrolytic solutions effect  comparative measurements were made
on resistors of three different types namely ceramic rod with helical
carbon film low resistance type carbon resin composition in ceramic
case high resistance type and capillary tube containing a solution
of cuso in water electrolyte type  the boella effect was most marked
in case  variation of resistance with electric field strength is
also observed  the explanation given is alternative to that of howe
   /
5642
natural frequencies of coils and windings  digest only  calculations
for an equivalent circuit consisting of reactors only were made using
punched card equipment an ac network analyser  the effect of neglecting
the mutual inductance between elements partly or completely is shown
graphically  very close agreement with measured natural frequencies
was obtained
   /
5643
air core coil design for crossover networks  simple analysis is given
for determining the correct wire gauge and optimum coil dimensions
for specified values of q and l  results are shown in charts and
numerical examples illustrate their use
   /
5644
three phase transudctor circuits for magnetic amplifiers
   /
5645
transistors theory and application part  switching circuits using
the transistor  counter circuits relaxation oscillators etc using
point contact transistors are described
   /
5646
the phase bistable transistor circuit  corrections to paper noted
in of
   /
5647
the eit decade counter tube  corrections and addendum to paper noted
in of february
   /
5648
a note on the network postulates  kirchhoff law that the sum of
the potential differences about any closed path of branches is zero
is repl ced by a version making no explicit references to paths of
branches  the resulting law can be interpreted geometrically in terms
of orthogonal subspaces of a certain vector space  the network definition
given is readily shown to be invariant under changes of basis
the equivalence between the new definition and the classical one
is established
   /
5649
the return difference matrix in linear networks  bodes concept of
the return difference is generalized by replacing the quantities
concerned by matrices  a formula for the fractionated gain is derived
which is a generalisation of thevenins theorem  formulae are also
derived for the stability of a circuit for the variation of its output
as a result of imperfections of the circuit elements and for the
input and output impedance  the method is particularly useful for
analysing multiple loop feedback circuits
   /
5650
a graphical contribution to the analysis and synthesis of electrical
networks  the contribution of the poles and zeros of a network function
to the steady state characteristics at real frequencies is considered
by means of vectors and the connection between attenuation and phase
is thereby accentuated  bodes relation between attenuation and phase
in minimum phase networks is derived by considering the contributions
from individual singularities and using a known definite integral
in a real variable  details are derived for the construction of a
series of templates useful for finding pole zero positions which
yield certain attenuation phase and delay characteristics and vice
versa  the method is illustrated by examples including the estimation
of the phase and delay characteristics corresponding to the given
attenuation characteristic of a minimum phase wide band amplifier
   /
5651
the relations between circuit pass band and signal build up time
two pass band criteria are discussed namely the bandwidth between
the points and the bandwidth defined in terms of special distribution
it is shown that these are not uniquely related and that it is not
possible to determine the time constant of a circuit solely from
a knowledge of its bandwidth
   /
5652
voltage reference node  description of a general method of analysing
linear networks by nodal analysis without specifying the node to
which all voltages are referred the network can be represented by
an indefinite admittance matrix which can be brought to a definite
form by omitting the row and column corresponding to a specified
reference node  the method is useful for dealing with valve circuits
with earthed grid or earthed anode stages or with no earthed electrodes
   /
5653
fused quartz ultrasonic delay line memory  the digit storage unit
described is of the type comprising a slab of fused quartz providing
a folded transmission path  methods are indicated for eliminating
spreading of the ultrasonic beam and mode conversion at the reflecting
surfaces thus reducing the intensity of spurious signals  an ultrasonic
frequency of is used and pulses with a dynamic range of can be stored
at rates
   /
5654
some notes on the properties and manufacture of piezoelectric quartz
crystals  the frequency stability temperature coefficient and activity
of quartz resonators are discussed and the relation between these
properties n and the oscillation frequency of a circuit including
the crystal is examined  the performance of some typical units is
shown graphically
   /
5655
double compensated tunable cavity  two frequency temperature compensation
of hermetically sealed cavities filled with dry inert gas is described
a typical performance curve is shown
   /
5656
differentiating circuits  passive network and feedback amplifier
types of differentiator are discussed and the performances of two
variants of the latter type are compared
   /
5657
determination of the input impedance of linear quadripoles by a graphical
method  the data required are the characteristic impedance the
load or terminal impedance and the propagation constant of the quadripole
two examples are worked out
   /
5658
build up phenomena in minimum phase networks  wheelers paired echo
method is used to evaluate the network response to a single pulse
and to a step voltage  the method is fundamentally a simplified application
of the fourier integral and is particularly useful for evaluating
the distortion with a minimum of computation
   /
5659
the equivalent q of rc networks  further comments on of brown
   /
5660
theory of twin t rc networks and their application to oscillators
the conditions are established which the circuit elements must satisfy
for the network to produce infinite attenuation at one frequency
and for the output to be either in phase or in phase opposition with
the input at on varying two elements in a particular manner  the
slope of the phase frequency characteristic at is compared with that
of a resonant lc circuit  one valve oscillators incorporating such
networks are discussed with particular attention to distortion and
stability  results of measurements on an oscillator are compared
with values calculated from theory
   /
5661
design procedure for crystal lattice filters  the technique of filter
design is described and formulae for the electrical and mechanical
constants of cut quartz crystals are given  a bridge net work of
two divided electrode crystals operating at has an image impedance
of
   /
5662
the basic design of constant resistance crossovers  a simple mathematical
analysis of the attenuation and phase characteristics for constant
resistance filters consisting of up to four elements  the frequency
response is shown graphically
   /
5663
a band pass filter for low frequencies  critical comment on of and
authors reply
   /
5664
duplexing filter design at mcs  the cavity resonator type filters
described are used in commercial communication equipment with transmitter
and receiver operating with a frequency separation of both receiving
and transmitting filters have a bandwidth of
   /
5665
a comparison of the properties of certain materials used in low power
microwave attenuators  results of measurements on morganite antistatic
gutta percha and carbon loaded bakelite indicate that if suitably
sealed to prevent ingress of moisture morganite is the best from
the point of view of stability
   /
5666
dc restoring of variable width rectangular pulses  the well known
diode dc restoring circuit is discussed the effect of deviations
of source impedance diode forward resistance and coupling capacitance
from their ideal values is investigated  the analysis is illustrated
by a practical example
   /
5667
starvation circuits and their limitations  the under running of valves
is deprecated on technical grounds  the valves so operated generally
tend to be unstable with variations in the supply voltage and with
age
   /
5668
a controlled frequency oscillator with frequency memory  an arrangement
is described in which a phase comparison afc system is used to keep
a first oscillator in tune with a second pilot oscillator  at a given
instant the control loop is broken thereafter the first oscillator
continues to operate at the frequency at the cut off instant and
subsequent frequency variations of the pilot oscillator are determined
from measurements of the phase difference between the two oscillators
a practical circuit which holds frequencies in a band centered on
is described
   /
5669
oscillator characteristic equation  the equation for an oscillator
circuit using a triode is developed in a form involving the differential
coefficients of the dynamic resistance of the triode  measurements
on a hartley oscillator are reported which are in good agreement
with the theoretical results over most of the oscillation characteristic
particular features of the oscillation characteristics are discussed
and the constants of the triode and the tank circuit are deduced
from them
   /
5670
effect of valve noise on oscillators  the magnitudes of the valve
shot effect and circuit thermal noise in oscillators are compared
when the oscillatory circuit is connected to the grid the valve noise
is relatively negligible when the oscillatory circuit is connected
to the anode the valve noise preponderates
   /
5671
tuned circuit oscillators at uhf  the design of a disk seal triode
oscillator for frequencies up to is discussed  the causes of spurious
resonance and their elimination are considered
   /
5672
high frequency resistance capacitance oscillators  the relative merits
of shunt capacitance and shunt resistance oscillators are discussed
the conditions of oscillation are analysed and the upper frequency
limits are examined
   /
5673
sinusoidal and relaxation oscillations sustained by nonlinear reactances
descriptions are given of various combinations of nonlinear components
eg a saturating choke with linear components eg a capacitor whereby
negative resistance characteristics can be obtained either of the
type in which current is a single valued function of voltage or of
the type in which voltage is a single valued function of current
practical applications are discussed
   /
5674
a transistor mcw adapter  a miniature keyed af rc oscillator is described
   /
5675
magnetic converter dc amplifer  the dc amplifier described comprises
a magnetic second harmonic converter followed by an ac amplifier
dc signals with power as low as can be amplified
   /
5676
audio nomographs  charts are presented for designing a pentode af
amplifier to have desired gain and bandwidth  the method involves
the use of separate equivalent circuits for the upper middle and
lower parts of the frequency band
   /
5677
disk seal triode amplifiers for decimetre wavelength radio links
amplifiers for increasing the transmitter output power and receiver
sensitivity in existing links are considered  grounded grid circuits
are used simple formulae are derived for gain and bandwidth giving
values in good agreement with experimental results obtained with
type and type valves
   /
5678
magnetic amplifier circuits and applications  a chronological survey
   /
5679
the surface barrier transistor part circuit applications of surface
barrier transistors  the operating characteristics of the surface
barrier transistor are discussed and two amplifier circuits are described
namely a wide band low pass amplifier and a band pass amplifier
for a centre frequency of  this type of transistor combines the ability
to operate at vhf with the low power consumption o of the junction
type  part below
   /
5680
mechanized production of electronic equipment  an illustrated account
is given of production methods developed at the national bureau of
standards based on modular design  a steatite water is used as a
basic unit on which components are printed or mounted over printed
wiring  six of these wafers are automatically stacked and connected
to form a plug in unit automatic silver painting tuning dip soldering
and testing machines are used  for other accounts see tech news bull
nat
   /
5681
automatic assembly of electronic equipment  description of a complete
production line for a radar chassis attaching machines fix components
on a printed circuit base plate
   /
5682
a flexible plated circuit  the wiring initially formed as a thick
cu electrodeposit on a stainless steel plate is stripped off on a
cloth backed adhesive tape  the complete manufacturing process is
described
   /
5683
the ignition mechanism of an electric gas discharge in a transverse
magnetic field at pressures of torr  continuation of work noted in
of january  a nonuniform field is obtained by making the radius of
the outer cylinder much greater than that of the inner  the ignition
characteristic ignition voltage magnetic induction electrode separation
obtained by calculation is compared with measurements in ar the agreement
is good  the ionization coefficient is independent of pressure
and the electron replacement coefficient is proportional to pressure
with high voltages and low magnetic fields the electrons are produced
mainly by ionic bombardment of the outer cylinder and by ion collisions
in the gas with low voltages and high magnetic fields the electrons
are produced mainly by ionic bombardment of the end surfaces  a formula
relating the electron replacement coefficient to the ratio between
the mean free path and the parameter of the cycloidal electron trajectory
gives results in good agreement with those derived from the observed
ignition characteristics
   /
5684
study of high frequency fluctuations from light sources using phototubes
and tuned radio frequency amplifiers  observations have been made
at frequencies up to using two different amplifiers for the ranges
below and above the methods of connecting the photocell to the amplifiers
are described  the spatial distribution of some types of oscillation
along the axis of vapour discharges was investigated  attempts to
observe fluctuations of light from the sun have been made only during
quiet periods and have so far yielded negative results
   /
5685
calculation of the behaviour of sparks with resistance and self inductance
in the circuit
   /
5686
analogue computer solution of the differential equation for a spark
gap  the differential equation derived by weizel is easily solved
by means of the pm ott integrator
   /
5687
neutralization of ions and ionization of atoms near metal surfaces
when an ion or an atom approaches a metal surface neutralization
or ionization processes are often possible  the franck condon principle
is applied in the determination of the probability of electron transfer
such transfers are limited to definite ranges of separation from
the surface  most secondary electron emission is due to an auger
type process the contribution due to de excitation of metastable
atoms being very small
   /
5688
ionization phenomena in gases  a brief summary of papers presented
at the conference held in oxford in july  the subjects discussed
included the spark arc glow and hf discharges gm counters and fundamental
processes
   /
5689
theory of ionized media with distant boundaries  continuation of
work noted in of  the theory is developed for a configuration in
which the electrodes are relatively close while the boundaries are
relatively distant  experimental results confirm the theory  the
solution of the differential equations involved and summarized theory
of the potential distribution in the mercury vapour rectifier arc
are given in appendices
   /
5690
ionization of gas by electrons  a statistical analysis is made of
the ionization produced by an electron when it is absorbed in hydrogen
linear integral equations are obtained for the average number and
the mean square fluctuations of the ion pairs  these are evaluated
approximately for high values of incident energy
   /
5691
on the current induced in a conducting ribbon by a current filament
parallel to it  the discussion presented makes use of results obtained
previously of and constitutes one stage in the determination of the
diffraction pattern obtained with a system of aerials in the presence
of a metal reflector of arbitrary size and shape
   /
5692
microwave optics  account of a symposium held at mcgill university
montreal in june
   /
5693
solution of electromagnetic scattering problems as power series in
the ratio dimension of scatterer wavelength  the calculation of the
successive terms in the series expressing the scattered field requires
only the solution of standard problems in potential theory together
with the evaluation of certain potential integrals  the series can
be calculated as far as desired if laplaces equation can be solved
but the calculation is increasingly complex for successive terms
the spries can be calculated as far as desired if laplaces equation
can be solved but the calculation is increasingly complex for successive
terms  the special case of scattering by a perfect conductor is also
considered and its relation to the problem of diffraction by an aperture
in a conducting screen is indicated  expressions for the distant
field are derived
   /
5694
electromagnetic scattering by an ellipsoid in the third approximation
the method described in above is used to evaluate the first three
terms of the power series in those in the term in vanishes because
of the symmetry of the scattering body  the result is expressed as
the sum of two elliptic integrals which are functions of the three
principal axes of the ellipsoid  the special cases of the spheroid
perfectly conducting ellipsoid perfectly conducting disk and of diffraction
by an elliptical or circular hole in a perfectly conducting
screen are considered
   /
5695
the vector wave function solution of the diffraction of electromagnetic
waves by circular disks and apertures part oblate spheroidal vector
wave functions  part the diffraction problems  the vector wave functions
considered are the solenoidal solutions of the vector helmholtz equation
oblate spheroidal vector wave functions are defined and the expansions
for plane polarized waves in terms of them are obtained  a unique
solution is obtained for the diffraction by an infinitely thin perfectly
conducting circular disk and by a plane conducting screen  two separate
groups of these functions are combined to fulfil the condition at
the rims of the aperture and disk using the spheroidal coordinate
system
   /
5696
diffraction of electromagnetic waves by an aperture in a large screen
the approximate solution of the three dimensional diffraction problem
is obtained by using a single component of the hertz vector  the
results are applied to the calculation of the field in the plane of
a circular aperture which is large compared with the wavelength
experiments confirm some of the theoretical results
   /
5697
diffraction of electromagnetic waves by two parallel half planes
the field of a plane wave diffracted by the edges of two parallel
conducting sheets has been measured close to the diffracting edges
for various spacings between the sheets  experimental results for
a spacing of one wavelength are compared with values derived from
theory presented by clemmow of the agreement is satisfactory
   /
5698
electronic and ionic impact phenomena  this work is likely to be
the standard reference book on the subject for some time to come
   /
5699
the radio echo from the head of meteor trails  calculations based
on diffraction theory give values for the intensity of head echoes
in agreement with observation and also indicate that the ratio between
the intensity of the head echo and that of a specularly reflected
body echo should be proportional to the radio wavelength and inversely
proportional to the difference in range between these echoes  other
anomalous meteor echoes may arise from discontinuities associated
with visual flares
   /
5700
radar determination of the height of disappearance of meteor trails
of known radiant  observations were made during the period august
at meudon using radar equipment operating on a wavelength of with
a peak power of about  curves representing the time variation of
the distance of the theoretically nearest reflection point for various
values of the height at which the trails disappear are shown together
with observed nearest reflection points  from the comparison it is
deduced that the mean value of h is about km
   /
5701
a symposium on radio astronomy at jodrell bank  account of the proceedings
at the symposium held in july
   /
5702
the distribution of radio brightness over the solar disk at a wavelength
of centimetres part the quiet sun one dimensional observations  assuming
the distribution over the solar disk to be circularly symmetrical
at this wavelength the derived radial brightness distribution shows
marked limb brightening  the observed distribution of brightness
is in fair agreement with the calculations made from solar models
involving a chromosphere and corona provided that the coronal densities
lie between and times the values usually quoted  conclusive evidence
of a quiet level rf emission was obtained  part of
   /
5703
two uhf radiometers mcs and some radio astronomy applications  details
are given of improved radio noise receiving equipment used for continuing the
experiments previously reported a power supply unit stable
to within part in for mains variations of a parabolic reflector aerial
for and a dipole aerial array for are described  measurements of
the distribution of rf brightness over the sun are reported these
include observations made during the solar eclipses of and
   /
5704
progressive variation of the shape of the sunspot curves  statistical
analysis of the sunspot numbers for the eleven year cycles since
indicates that the asymmetry of the curves is increasing thus giving
support to gleissbergs theory that there is another cycle with a
period the order of thousands of years
   /
5705
measurement of variations in atmospheric refractive index with an
airborne microwave refractometer  the cavity resonator refractometer
described is essentially the same as that used for previous measurements
of birnbaum  observations were made at heights up to examples of
strip records obtained are reproduced  the variations were negligible
for distances m  large increases of refractive index were observed
on entering cumulus clouds and intense fluctuations were noted within
the clouds
   /
5706
airborne magnetometer for determining all magnetic components  description
of the airborne vector magnetometer type an enlarged and modified
form of the instrument previously described by felch et al of
   /
5707
measurements of the terrestrial magnetic field in the e layer  two
methods are outlined both based on determination of the gyro frequency
which is related by a simple formula to the intensity h of the geomagnetic
field in the lower part of the e layer  the first method is based
on the double hump resonance curve and the second is based on the
self demodulation of radio waves at carrier frequencies near gyrofrequency
a stable is given of values of h determined by these methods
in italy
   /
5708
a universal time component in geomagnetic disturbance  evidence of
a universal time component in diurnal variation of the geomagnetic
disturbance is obtained from an analysis of k index figures
   /
5709
low frequency noise in the range  continuation of previously noted
investigations of and of the correlation between lf em fluctuations
and geomagnetic and solar phenomena  a pickup loop with an effective
area of was used with an amplifier having a gain of and a recorder
with chart speed of  an operating site with low noise characteristics
was chosen  evidence was obtained of frequent storms in the noise
frequency range studied  a diurnal variation similar to that of the
cheltenham k indices was observed  analysis indicates significant
correlation between the lf noise and solar noise observed days earlier
   /
5710
daily variation of amount of ozone in the atmosphere  observations
made at mount abu and ahmedabad from nov to april showed a substantial
increase of ozone during night hours with rapid change over from
day to night values after sunset
   /
5711
an interpretation of vertical incidence equivalent height versus
time recordings on  the results of observations made in pennsylvania
usa between january and april are shown graphically and discussed
one form of echo regularly observed during magnetically disturbed
nights is due to one type of sporadic e stratum  recorded group and
phase heights are compared and the differences compared with those
predicted from theory  results are also given of a preliminary investigation
of the effects of solar flares
   /
5712
investigation of travelling disturbances in the ionosphere by continuous
wave radio  continuous records of the signal intensity of cw transmissions
over a path at and indicate an f layer disturbance velocity of
transmission modes up to and respectively were observed  simultaneous
signal intensity records of two in line transmitters p apart operating
at showed a constant min interval between the corresponding maxima
indicating a disturbance velocity of
   /
5713
the effect of soft x rays from the solar corona on the formation
of the normal ionospheric e layer  a calculation has been made previously
of the soft x rays from the solar corona vol  the results are
used to determine the height at which the radiation is absorbed and
the number of electrons present at this height under equilibrium
conditions  the results agree well with observations of the normal
e layer
   /
5714
the structure of the f region of the ionosphere  the effects of temperature
cycles of a decay coefficient which is nonuniform with height
and of vertical tidal drifts are considered  the diurnal and seasonal
height variations of the f region are explained qualitatively by
postulating in addition to the vertical tides acting on an isothermal
chapman region a diurnal temperature cycle  this requires a decay
coefficient which does not change rapidly with height  on an alternative
hypothesis involving discontinuities in the height gradient of the
decay coefficient tidal drifts are still necessary but a diurnal
temperature cycle is not of major importance
   /
5715
world wide diurnal variations in the f region  the chief characteristics
of the variations are described in terms of the sunspot minimum anomaly
the sunrise anomaly and the diurnal range anomaly  these anomalies
are evaluated quantitatively and extracted from the observations
to determine the normal curves  the world distribution of these anomalies
is studied and explanations are suggested  variations of do not
appear to be related either to the sunspot cycle or to the variation
   /
5716
the electron content of the f layer above singapore  a comparison
of the estimated total ionization present in a unit column below
the level of maximum ionization density of the f layer in and in
   /
5717
geomagnetic and ionospheric relationships  the effect of a magnetic
disturbance on various geomagnetic and ionospheric parameters is
investigated by choosing days on which the sum is markedly different
from that of the adjacent days  most of the parameters show a peak
or trough corresponding to that of the disturbance following it with
a delay of hours  particular attention is called to some peculiar
seasonal effects to features of of the sporadic e layer at slough
and the vertical movement of the f layer at huancayo
   /
5718
the effect of the magnetic equator on the ionization of the e layer
observations made at stations at different latitudes in africa and
europe are analysed  daytime values of e show a pronounced maximum
at the magnetic equator  observations of the e blanketing frequency
indicate that the e minimum ionization ceiling is not subject to
the effect which exists only for the ionization clouds
   /
5719
winds in the ionospheric regions  a model for the region between
and height is constructed from considerations of the temperature
gradients and the observed wind velocities  according to this model
the wind is south west in the e and f regions and north east or east
in the f region its velocity increases from at km to at  there is
a seasonal variation in the magnitude of the velocity but the model
does not involve any diurnal or seasonal changes of direction such
as have been reported by observers
   /
5720
results relating to the critical frequency and the transmission factor
of the ionosphere f layer
   /
5721
a note on auroral interaction  the modulation of a radio wave due
to a moving auroral reflecting screen is discussed
   /
5722
a nonlinear servomechanism with several independent variables
   /
5723
radioactive charging effects with a dielectric medium  the characteristics
of a cell consisting of a ray source a polystyrene dielectric
separator and a collector made of carbon or metal were investigated
radioactive current and voltage sources similar to this cell are
feasible  the arrangement offers a simple way of studying the effects
of radiation on electrical processes in solids
   /
5724
the problem of heating in the selenium rectifier  formulae for the
calculation of heat losses are derived  design for good efficiency
and low temperature rise is discussed in detail with reference to
the operational demands of various applications in power rectification
typical characteristics curves are given
   /
5725
recent developments in ignitrons
   /
5726
stabilization problems in physics  a review of voltage current and
magnetic field regulators  the performances of various stabilizing
valve circuits and primary regulators are compared and the importance
of good control of filament heating voltages is emphasized  special
problems of stabilization in nuclear physics are mentioned
   /
5727
a stabilized dc supply unit for output voltages of to  a circuit
is described in which the whole of the output voltage variation is
available for controlling the amplifying valve so that the gain is
the same for any output voltage down to zero  the control valve is
a pentode whose screen grid voltage is stabilized by means of a stabilizer
tube the filaments of the amplifying valves which are also fed
from this source have low consumption  variation of the output voltage
is for mains fluctuations up to
   /
5728
relaxation oscillations in voltage regulator tubes  relaxation oscillations
may occur if the regulator tube is shunted by a capacitor and
the load line intersects the tube characteristic on the low current
side of the minimum  methods of modifying the circuit to prevent
these oscillations are indicated
   /
5729
an alternating current stabilizer  a stabilizer for a valve heater
power supply uses a diode operating with low heater voltage as the
error detector and a transductor as the control element  the output
voltage can be maintained constant to within
   /
5730
industrial tube generator for low frequencies  a detailed description
is given of a three phase valve generator suitable for supplying
an asynchronous motor at frequencies from to
   /
5731
phantastron computes pulse width ratios  description of an analogue
computer developed for determining the ratio of the widths of two
pulses occurring simultaneously in two channels of a radar system
the output is readily convertible into digital form  other applications
are indicated
   /
5732
programme control of an electronic computer
   /
5733
digital computers at manchester university  an account is given of
the development of the universal high speed computer its features
include a cr tube store for binary digits an intermediate store for
more than digits completely automatic transfer between the two stores
a fast multiplier and input and output systems using hole teleprinter
tape
   /
5734
the construction and operation of the manchester university computer
the account particularly stresses techniques used to achieve reliability
and ease of maintenance and includes details of the performance over
a period of about weeks  see also above
   /
5735
universal high speed digital computers a decimal storage system
discussion  three decimal digit storage systems using cr tubes are
described  the best compromise as regards speed of operation storage
capacity and reliability is obtained with a cr tube screen comprising
ten separate elements  in a serially controlled store holding words
of decimal digits the digit period was and could be reduced to  these
results compare favourably with those for the binary store used in
the manchester university computer
   /
5736
the design and testing of an electronic simulator for a hydraulic
remote position control servo mechanism  discussion on of
   /
5737
analogue computers for feedback control systems
   /
5738
transformer analogue network analysers  the use of voltage transformers
as multipliers for complex quantities is explained  a network analyser
is described comprising a measuring section and a number of identical
panels each with two multiplying units  these panels can be used
to represent impedances admittances etc  negative resistance and
unilateral mutual inductance can easily be represented  applications
discussed include the solution of linear simultaneous equations
   /
5739
valve reliability in digital calculating machines  a discussion of
measures which can be taken to reduce the number of valve failures
and to reduce the inconvenience caused when failures do occur
   /
5740
recent advances in cathode ray tube storage  modifications have been
made to the system described by williams and kilburn of and used
in the manchester university computer the defocus focus system and
the signal amplifier are discussed particularly  an account is given
of experimental work undertaken to clarify the storage mechanism
the theoretical basis of the system is examined the original theory
through inaccurate in detail is satisfactory for practical purposes
and can be used to predict storage results  the tube operation is
analogous to that of a triode valve the collector bombarded spot
and surroudning screen surface corresponding respectively to the
anode cathode and control grid
   /
5741
a multi decade predetermined counter  the automatic four decade counter
described is a modified version of that noted in of february  the
maximum counting rate is per sec and the minimum duration of a complete
cycle of counts is ms
   /
5742
directional coupling with transmission lines  adaptation of devices
developed in connection with waveguides to forms with open wire lines
for use at lower radio frequencies
   /
5743
response of an amplifier stage with antiresonant circuit to an input
voltage whose instantaneous frequency varies linearly as a function
of time  analysis is given for an input which can be represented
by a particular fourier integral
   /
5744
equivalent network representations for solid and mercury delay lines
an equivalent network representation is obtained from consideration
of the piezo electric properties of the quartz crystal used to convert
the electrical energy into ultrasonic energy  a formula is derived
for the transfer function of the line  when mercury and fused quartz
lines are compared on the basis of the gain bandwidth product only
the fused quartz line is superior but other factors eg production
of spurious signals must be taken into account when selecting a line
for a specific application
   /
5745
characteristics of an elliptical electromagnetic resonant cavity
operating in the te mode  equations and graphs are presented of the
resonant wavelength and quality factor of elliptical resonant cavities
operating in the te mode  both components of this mode are treated
and distinctive characteristics of each are shown as a function of
eccentricity of the cavity
   /
5746
interaction between classical electron and quantized electromagnetic
field  the equations of motion are solved by a method involving the
corresponding difference equations and an expression is derived for
the probability of transition between a high energy state and neighbouring
states of the field inside a resonant cavity
   /
5747
the transformation properties of loss free quadripoles between homogeneous
lines and a proof of weissflochs transformation law using circle
geometry  a method for evaluating certain parameters in the application
of weissflochs transformation law and back references  this law has
applications in measuring technique and circuit theory in the cm
and dm regions
   /
5748
on the synthesis of reactance poles  using theory developed by belevitch
formulae are derived for the elements of the impedance or admittance
matrix of a loss free quadripole which when terminated by a resistor
realizes a prescribed physical driving point impedance
   /
5749
a block diagram approach to network analysis  an extension of the
method described by graybeal to electrical networks with examples
of application in the analysis of ladder bridged t and parallel t
networks
   /
5750
ferrites in microwave applications  a discussion of the microwave
faraday effect and of the mechanism of power absorption in ferrites
plane wave theory is given and is extended to cover waveguides  the
measurement and applications of the effects are surveyed  see also
of
   /
5751
coupled lines as high frequency transformer  systems comprising two
parallel two conductor lines r are considered  voltage and current
distribution and input impedance are calculated in terms of terminating
impedance overlap length and coupling  an indication is given of
the requirements to be satisfied for wide band operation and some
particular arrangements are discussed
   /
5752
tentative graphical representation of the image transfer coefficient
of ladder type filters with or without losses  the method is based
on the expression of the image transfer coefficient as a function
of frequency in accordance with the classification of filters given
previously of and
   /
5753
a set of octave band pass filters for frequencies between and  filters
designed for eliminating harmonics are described  in order to achieve
the desired sharp cut off on the high frequency side the filters
are operated into an abnormally low impedance about a tenth of the
centre frequency impedance
   /
5754
broadband rotary waveguide attenuator  the attenuator comprises three
collinear sections of round waveguide each with a resistive film
arranged in a diametral plane the middle section is rotated to obtain
the desired attenuation  some performance figures are given for an
experimental model the characteristics are independent of frequency
   /
5755
a general network theorem with applications  slightly modified reprint
of paper noted in of
   /
5756
chameleon oscillator  an oscillator giving high frequency stability
and using relatively few components is based on a cathode coupled
hartley circuit with resistance in the cathode lead
   /
5757
the measure of activity of oscillators and the performance index
the measure of activity of an oscillator is defined as the ratio
of grid voltage amplitude to anode current amplitude  in crystal
controlled oscillators it is proportional to the crystal performance
index  the measure of activity is evaluated for several common types
of oscillator
   /
5758
design of heterodyne oscillators  the choice of frequencies for producing
a given beat frequency and the design of the variable tuning capacitor
are considered  precautions required to ensure frequency stability
are discussed
   /
5759
the operation of generators for steep fronted waves  when the self
inductance of the generator is taken into account in the analysis
a third order differential equation is obtained simplification is
introduced by taking advantage of a particular solution  graphical
methods of investigation based on the work of bergeron are also outlined
   /
5760
transistor oscillator for use in multifrequency pulsing current supply
discussion of an oscillator for use in the transmission of digital
information at frequencies in the band over telephone trunk lines
performance details are given
   /
5761
introduction to the use of electronic tubes in pulse techniques
circuit phenomena produced by switching are briefly reviewed and
the operation of valves as nonlinear or switching elements is discussed
as an introduction to the consideration of some well known pulse
circuits
   /
5762
a special time discriminating selector for electronic pulses  a circuit
is described which is able to select the last of a series comprising
an arbitrary number of pulses distributed in an arbitrary number
of pulses distributed in an arbitrary way within a fixed time interval
   /
5763
determination of the noise factor of various amplifiers by a comparison
method  the relative noise factor can be determined by using a standard
type signal generator connected to the input of the amplifier and
a band pass filter coupled to a valve voltmeter at the output
   /
5764
wide band if amplifiers  bandwidths such as are required for dealing
satisfactorily with very short pulses are achieved without necessitating
alignment of the amplifier with a particular set of valves by using
a negative feedback design technique  the amplifier is treated as
a series of pairs of valves the first of each pair operating without
and the second with feedback  a table gives component values in a
form requiring a minimum of computation  a particular stage amplifier
designed by this method for a centre frequency of had a bandwidth
of to the points and an overall gain of about the response varied
only very slightly when all the valves were changed
   /
5765
magnetic amplifier uses conventional inductors
   /
5766
negative inductance cuts magnetic amplifier lag  the speed of response
of a magnetic amplifier is improved without reducing its sensitivity
by balancing out the effect of control circuit inductance by means
of a negative inductance device comprising a valve with an iron cored
mutual inductor
   /
5767
the design of a practical dc amplifier based on the second harmonic
type of magnetic modulator  discussion on of
   /
5768
transistors theory and application part cascading transistor amplifier
stages  formulae and values of circuit parameters are tabulated for
various possible arrangements using point contact or junction transistors
   /
5769
power transistors for audio output circuits
   /
5770
physical basis of thermal noise  an examination is made of methods
developed by various workers for analysing circuit noise due to random
motion of charge carriers  it is concluded that it is not necessary
to postulate thermodynamic equilibrium in order to be able to calculate
the thermal noise
   /
5771
principles of transistor circuits  a comprehensive work on transistors
and their circuitry written by nine members of the staff of the electronics
laboratory of the gec company of america
   /
5772
modulators and frequency changers  for research development and maintenance
engineers  high power transmitting modulators are not treated
   /
5773
graphical presentation of oscillator resonance applicable to the
study of nonlinear systems
   /
5774
derivation of the laws of geometrical optics from maxwells field
theory
   /
5775
the diffraction of electromagnetic waves by a semi infinite circular
waveguide  formulae are obtained for the currents on the waveguide
and asymptotic expressions are derived for the longitudinal components
of the electric and magnetic vectors in the waveguide at large distances
from the mouth
   /
5776
a collective description of electron interactions part collective
vs individual particle aspects of the interactions
   /
5777
the electromotive force developed by a creeping zinc crystal
   /
5778
theory of plasma waves in metals  the hartree approximation is used
to investigate the effect of the crystal lattice on plasma oscillations
in metals  a formula is derived for the oscillation frequency for
free electrons this reduces to that given by bohm and gross for insulators
there are no oscillations  in metals with occupied d bands there
is strong coupling between the plasma oscillations and the d electrons
causing frequency broadening
   /
5779
theory of ac space charge polarization effects in photoconductors
semiconductors and electrolytes  linear theory is developed for solid
or liquid materials containing charge carriers which can move freely
within the material but are blocked by the electrodes  the carriers
may be electrons holes ions or ion vacancies  the general solution
for the admittance of the material is obtained for an arbitrary ratio
between the mobilities of positive and negative carriers and is discussed
for some special cases  results are compared compared with those
derived from other theories
   /
5780
the field emission initiated vacuum arc part experiments on arc initiation
the experiments were carried out under conditions of high vacuum
and clean cathode surface  results show that breakdown is immediately
preceded by recognizable emission anomalies that breakdown occurs
at a critical current density of the order of for applied microsecond
pulses in the range and that breakdown is independent of cathode
bombardment
   /
5781
the field emission initiated vacuum arc part the resistively heated
emitter  theory is developed for the heat flow in an emitter of geometry
approximating to that used in the experiments reported in above
the calculations support the view that breakdown is initiated by
a resistive heating process
   /
5782
space charge effects in field emission  a progressive reduction of
the observed field current below values expected from the empirical
law for increasing values of the potential is attributed to space
charge  the current density expected in the presence of space charge
is calculated from the fowler nordheim field emission theory using
values of the cathode electric field obtained from a solution of
poissons equation for plane electrodes with boundary conditions appropriate
to field emission  the result is a generalization of childs
equation and is asymptotic to it when the applied potential is large
compared with the value for appreciable field emission
   /
5783
brillouin flow with thermal velocities  a type of electron flow in
a constant magnetic field is described  the beam of electrons is
supposed to be everywhere in thermal equilibrium and the usual brillouin
flow is found when the equilibrium temperature tends to zero  some
considerations are put forward bearing on the choice of a suitable
beam temperature in specific problems
   /
5784
a modified theory of production of secondary electrons in solids
difficulties in previous theories of energy loss and secondary electron
production in metals are removed by replacing the coulomb interaction
between a primary electron and a lattice electron by a screened coulomb
interaction
   /
5785
magneto ionic theory of weakly ionized gases in the presence of an
oscillating electric field and a constant magnetic field  the velocity
distribution functions for a nonuniformly ionized gas are calculated
by solving the boltzmann differential equations  explicit expressions
are derived for the magneto ionic conductivity the dielectric tensor
the hall effect the deflection of the electron beam and the generalization
of langevins mobility formula  comparison is made with other
methods of calculation
   /
5786
the conductivity tensor of electron plasmas in the presence of a
constant magnetic field  assuming the mean collision frequency to
be independent of velocity it is shown that the form of the ct of
velocity it is shown that the form of the conductivity tensor given
by jacel and kahan above differs from that given by huxley of  in
order to represent the magnetoresistance terms correctly by jancel
and kahans method closer approximation is necessary
   /
5787
some magnetic properties of metals part surface corrections of the
landau diamagnetism and the de haas van alphen effect  an expression
is given for the magnetic moment of a large but finite system of
electrons in terms of the volume and two mutually perpendicular surface
areas together with constants independent of the shape of the system
the theory is verified by calculating the values of the constants
for two different shapes  corrections to part are noted
   /
5788
a two electron example of ferromagnetism  the method of dealing with
problems of ferromagnetism on the basis of energy band theory vol
is applied to a simple case
   /
5789
the law of induction  a survey of the literature indicates a lack
of clarity on this subject  the law of induction is formulated generally
in terms of a geometrical entity called the flux line which exists
in te field of a solenoidal vector
   /
5790
induction phenomena consequent on the movement of material in primary
magnetic fields and their experimental applications part fundamental
theory for very general cases  theory applicable to any type of motion
is developed
   /
5791
motion of an electron in a magnetic undulator  rigorous solutions
are obtained for the equations are obtained for the equations of
motion of an electron in a millimetre wave generator of the type
described by motz et al of
   /
5792
frequencies and power of waves radiated by a magnetic undulator
continuation of investigation noted in above  the dimensions of an
undulator for generating mm waves are determined from rigorous calculations
of electron trajectories  the results differe greatly from values
derived from classical theory  the values found for radiated power
are of the same order
   /
5793
the equations of propagation of electromagnetic waves in an ionized
gas  two different methods are used to derive the equations for the
propagation of em waves in an ionized gas subjected to a time varying
em field and to a constant magnetic field terms depending on past
states are found to occur
   /
5794
effect of a metal plate on total reflection  the phase changes which
occur on total reflection are modified when a metal plate is placed
near and parallel to the reflecting boundary by moving the plate
the phase difference between plane waves of equal amplitudes polarized
in and perpendicular to the plane of incidence can be varied from
up to the positive value obtained without the plate this has been
confirmed experimentally using a wavelength of and a perspex prism
when the refractive index is there are two positions of the plate
for which the reflected wave is circularly polarized the electric
vector rotating in opposite directions for these two positions
   /
5795
theory of a conductor near the boundary of two media  the electromagnetic
field due to an oscillation of angular frequency in the conductor
can usually be split into two components a cylindrical wave field
and a spherical wave field  near the axis of the conductor which
is parallel to the boundary plane the field is of a special type
the condition for the existence of the two components is derived
and applied to particular cases
   /
5796
deflection of high energy electrons in magnetized iron  the effective
magnetic field acting on electrons traversing a ferromagnetic medium
is shown by experiments to be equal to the flux density
   /
5797
radio echo studies of meteor ionization  the physical properties
of the meteors and the columns of ionization which they produce and
the properties of the atmosphere in the meteor ionization region
were investigated using mainly pulse equipment operating in the waveband
the development of a satisfactory theory of scattering of radio
waves from meteor trails together with the theory of evaporation
from meteors makes possible the detailed interpretation of the radio
echoes obtained  in particular the estimated incident flux of meteors
is found to be sufficient to maintain a continuous ionospheric layer
extending from down to below which ionization will be distributed
in patches becoming fewer and larger with decreasing height  over
references
   /
5798
observations of solar radio noise storms  observations indicate that
simple storms ie those caused by a single bipolar group of sunspots
exhibit a directional effect varying with wavelength
   /
5799
radio noise bursts from solar m regions  the passage of m regions
is characterized by a notable increase in the short term variability
of noise intensity at m
   /
5800
ionization and recombination processes in a plasma and the ionization
formula of the solar corona  for a plasma not in thermodynamic equilibrium
formulae are derived for the photo ionization the ionization
by collisions the recombination with emission of light and the recombination
due to triple collisions  by equating the number of collisions
by equating the number of collision ionizations with the number of
photorecombinations an ionization formula is obtained for the solar
corona from which the temperature of the corona can be estimated
   /
5801
radio frequency radiation from the spiral nebula messier  the intensity
measurement of the radio source observed has been combined with previous
observations to determine the ratio between the radio flux and the
light flux for individual nebulae  the calculated flux from a nebula
of apparent magnitude is at
   /
5802
an extended radio frequency source of extragalactic origin  extension
of observations noted in of
   /
5803
statistical analysis of geophysical time series  notes are provided
on dealing with the effects of linear and periodic trends on standard
deviation and correlation coefficient  significant tests in coherent
series are discussed
   /
5804
the phased superposed epoch method of analysis and an application
to geomagnetic activity  a method is described in which geomagnetic
activity variations are analysed by grouping the data according to
their phases increasing decreasing or no change as determined by
considering the characteristics for pairs of successive days
   /
5805
geomagnetic activity and the sunspot cycle  a table is given for
the last four sunspot maximum epochs of the numbers of magnetically
calm days and of slightly moderately and highly disturbed days together
with sunspot numbers and a measure of the prominence activity  geomagnetic
activity shows correlation with prominence activity rather than
with sunspot activity
   /
5806
diurnal magnetic variations near the magnetic equator  observations
made at nine places in south india are analysed in conjunction with
observations for south america  high diurnal ranges of h occur in
a belt of latitude with a maximum near the magnetic equator
   /
5807
abnormal ionospheric absorption observed during february  observations
from stations all over the world are analysed  very high absorption
was observed during the period february within a limited region
the eastern and western limits of the affected region are not known
accurately because of the sparseness of stations no effect was observed
in america or in the far east  the southern limit was observed in
africa roughly along the line joining casablanca and djibouti  an
explanation involving corpuscular radiation fits the observations
better than one based directly on wave radiation from the sun  the
absorption is thought to occur in low altitude ionized layers such
as that detected by gnanalingam and weekes of
   /
5808
a self consistent calculation of the dissociation of oxygen in the
upper atmosphere part three body recombinations  continuation of
work noted in of  results based on the assumption that recombination
occurs mainly as a three body nonradiative process indicate that
dissociation occurs at a level about higher than that previously
calculated
   /
5809
bifurcation of the e region  the retardation time relative to an
uhf reference signal of a radio signal of frequency about above the
critical frequency was measured by rocket borne instruments  electron
density altitude graphs were derived from the retardation time time
of flight records bifurcation of the e layer is clearly indicated
the results are in close agreement with those calculated from records
obtained with the nbs model c ionosphere recorder  the separation
of the electron density maxima was km
   /
5810
direction finding studies of large scale ionospheric irregularities
continuation of work noted in of  a report is given of measurements
on pulse modulated transmissions in the frequency range reflected
from the ionosphere  both vertical incidence and oblique incidence
observations were made  the directional variations of the reflected
signals were studied and are interpreted as due to tilting or wrinkling
of the constant ionic density surfaces in the ionosphere  the results
indicate large scale horizontal movements in the ionosphere  in the
e layer these appear to be of the nature of drifting clouds of ionization
while in the f layer the effects are consistent with horizontally
travelling ripples having wavelengths of and speeds up to  the direction
of motion is more often towards east or west than towards north or
south and evidence of a diurnal variation has been observed
   /
5811
reflexions from irregularities in the ionosphere  complexities in
records of and for the f region are shown to be due to curvature
of the reflecting surface  the order of curvature associated with
travelling disturbances is calculated and the variation in the type
of complexity is shown to result from differing group retardations
in the different paths  a base triangular system of three pulse transmitters
and a panoramic type recorder were used respectively for and
recording
   /
5812
examination of the formation of the ionosphere f region  continuation
of work noted in of  two different possible mechanisms are discussed
namely photo ionization of and ionization by soft x rays  the photoionization
hypothesis is only acceptable if the dissociation of the is
assumed to take place at a relatively high altitude of about km
ionization by x rays of solar origin certainly occurs but a recent
calculation of the spectral distribution of solar energy indicates
too high an ionization at km
   /
5813
recombination coefficient in the f regions a possible new process
of ionization of nitrogen molecules  discussion of a possible dissociative
recombination process according to which the daytime solar radiation
at visible wavelengths may be instrumental in ionizing nitrogen molecules
if positively charged particles are present
   /
5814
the solar eclipse of at gao  ionosphere observations made during
the eclipse are reported  though the occultation was only partial
a diminution of e and f layer ionization compared with normal days
was observed the effect was very pronounced at hours when the sunspot
near the western limb of the sun was obscured  on the other hand
when this sunspot disappeared on february as a result of the rotation
of the sun there was no noticeable reduction of the e layer ionization
the effect is difficult to explain in terms of classical theory
the diminution of ionization of the f layer is significant
   /
5815
ionosphere review  twelve month running averages and monthly mean
values are plotted for the sunspot numbers and the noon and midnight
f critical frequencies from  it is inferred that the critical frequencies
are likely to decrease only very slightly before the next sunspot
minimum and that the latter is to be expected between march and april
   /
5816
the agrimeter for continuous recording of the atmospheric electric
field  description of an instrument based on measurement of the bound
charge on a portion of the earths surface
   /
5817
the pilot streamer in lightning and the long spark
   /
5818
the study of lightning streamers with cm radar  radar echoes were
observed during the whole period between the successive strokes in
a lightning flash  some components of these echoes appear to be associated
with the processes leading up to the next stroke  photographic
cro trace records of the stroke at its commencement and ms later
are reproduced and discussed
   /
5819
methods of synchronizing the observations of a sterics network  methods
in use in the british network are described
   /
5820
analogue methods for optimum servomechanism  design
   /
5821
feedback control systems with dead time lag or distributed lag by
root locus method  generalization and application of the method originated
by evans of
   /
5822
synthesis of feedback control system by phase angle loci  a modification
of evans root locus method
   /
5823
the use of nonlinear tachometric feedback to improve the transient
response of a servomechanism
   /
5824
stabilization of a servomechanism subject to large amplitude oscillation
the frequency response method of analysis developed by kochenburger
of is applied to a system containing a saturable amplifier and in
determining the required nonlinear stabilizing filter
   /
5825
stability limits for third order servomechanisms  curves are derived
giving directly the roots and coefficients of specified cubic characteristic
equations  their use in facilitating analysis and design of
servo systems is explained and illustrated
   /
5826
the analysis of sampled data systems  full paper summary abstracted
in of
   /
5827
stable power supplies for microwave standards  a description of the
power supply system for operating the klystron frequency standards
at the national bureau of standards
   /
5828
selenium rectifiers factors in their application
   /
5829
design of relays  a symposium of papers dealing with design production
service and measurements
   /
5830
hhhfn analogue type multiplier  a simple multiplying circuit is described
in which rectangular pulses are modulated successively in width
and amplitude in proportion respectively to the two factors a and
b to be multiplied  response times for the circuit tested were for
the factor a amplitude and irrespective of amplitude for b
   /
5831
a simple electronic multiplier  the multiplication process described
is based on the equation xy  a method of squaring is used which depends
on the fact that the areas of similar triangles are proportional
to the squares of their heights a triangular waveform generator is
described  the device accepts both positive and negative input voltages
   /
5832
electronic analogue computing  a survey of modern techniques an indication
is given of the kind of problem for which analogue computers
offer advantages over digital types
   /
5833
a new analogue computer  a general purpose computer of differential
analyser type designed for economic quantity production is described
three basic elements are used viz scaling units essentially decade
variable resistors function units comprising rc networks high gain
amplifiers  facilities for cro and graphical display are provided
   /
5834
note on high speed product integrator  errors arising in the potentiometer
circuit of the integrator are discussed
   /
5835
general survey of the operating principles of electrical analogue
computers  a survey with particular reference to computers constructed
by the societe d electronique et d automatisme difficulties encountered
in studying the accuracy of these machines are discussed
   /
5836
a diode capacitor memory for high speed electronic computers  ordinary
linear capacitors are used as rapid access storage elements in a
matrix arrangement  the basic circuit consists of two diodes in series
with the anode of one connected to the cathode of the other and the
capacitor connected to the junction the other end of the capacitor
is used for reading and writing and is connected to earth through
a resistor
   /
5837
a survey of digital computer memory systems  correction to paper
abstracted in of january
   /
5838
elements of boolean algebra for the study of information handling
systems  correction to paper abstracted in of january
   /
5839
application of digital computing techniques to physics  problems
involving matrices ordinary and partial differential equations functions
occurring in crystallography and the random walk statistical method
are discussed  machine design and the training of personnel are considered
briefly
   /
5840
magnetic and dielectric elements for computers  a survey of the applications
of materials with rectangular hysteresis loops  two classes
are distinguished namely those depending on a high ratio of remanence
to saturation and those for which the squareness ratio is important
   /
5841
a low frequency oscillator  an analogue computer for solving the
differential equations of a mass spring system comprises a circuit
producing simple harmonic oscillations with a frequency range of
   /
5842
instantaneous multiplier for computers  multiplication is performed
by means of balanced modulators using standard if transformers and
other components
   /
5843
pulse height analyzer  the equipment based on wilkinsons conversion
principle of has resolution linearity and stability to within it
can deal with input pulses at a rate of several thousand per second
recording is made on teledeltos paper at a rate of up to pulses sec
   /
5844
a new general method for frequency distortion correction of a given
circuit in light current and instrument engineering  the frequency
dependent function eg the amplification factor is expressed as the
ratio of power series of functions of the frequency and the condition
for a minimal frequency dependence is found
   /
5845
normalized phase and gain derivatives as an aid in evaluation of
fm distortion  the method previously described for evaluating the
distortion for the quasistationary condition of is extended to take
account of the finite rate of variation of the input signal frequency
   /
5846
transient response of the grounded base transistor amplifier with
small load impedance  a transfer function relating junction transistor
collector current to emitter current is derived from the diffusion
equation the laplace transform technique is used to determine the
variation of collector current in response to a step variation of
emitter current  collector current rise times evaluated from the
theory are in good agreement with observed values
   /
5847
thermistor production  reprint with additional illustrations of paper
abstracted in of
   /
5848
tapped inductances  maxwell coils for af are considered and a simple
method is presented for calculating the position of the tapping to
give a specified fraction of the total inductance
   /
5849
graphical analysis of nonlinear circuits using impedance concepts
approximate values of the reactance of moderately nonlinear inductors
and capacitors are obtained by adding to the usual linear expressions
terms involving the square of the current  using this approximation
the total impedance of an lrc circuit is obtained and plotted in
the iz plane with frequency as a parameter  the method gives a physical
picture of the jump phenomenon in nonlinear circuits
   /
5850
large reduction of free electromagnetic oscillations in cylindrical
regions due to slight departures from cylindricity  a theoretical
investigation of the effect of small deformations on long cylindrical
resonators with perfectly conducting walls  the diminution of the
field is proportional to the product of the relative distortion and
the square of the ratio of the length of the cylinder to its radius
standard mathematical notation is used and the expressions for are
given in terms of bessel functions and the function which is defined
as the root of j
   /
5851
an asymmetrical finite difference network  a study is made of a method
of solving boundary value problems by means of electrical network
analogies  consideration is given to the special problems associated
with curved boundaries and with the use of meshes of different size
at different parts of the network  a method is described by means
of which the coefficients of the system of algebraic equations can
be computed for an arbitrary distribution of node points and the
position of the nodes can then be chosen to fit the particular conditions
as an illustration the resonance frequencies and field patterns
of a conical line cavity resonator are calculated
   /
5852
a general rlc synthesis procedure  procedure for synthesizing lattice
networks is described
   /
5853
unbalanced rlc networks containing only one resistance and one real
transformer
   /
5854
unilateral four terminal circuits  networks of ge diodes and carbon
resistors suitable for purposes of directional coupling and isolating
are described
   /
5855
high q coupled tuned circuits  by means of a set of expressions developed
as functions of a frequency ratio some aspects of inductively
coupled high q resonant circuits are analysed  considerations of
finite very high q circuits lead to simple relations determining
impedance characteristics of a fundamental system resonant frequencies
rate of frequency deviation input conductance stored energy and power
dissipation ratios
   /
5856
two new equations for the design of filters  equations are presented
for designing constant k configuration filters with tchebycheff type
characteristics for the case when the unloaded q of the elements
is sufficiently high for them to be considered nondissipative  both
band pass and low pass filters are considered the band pass examples
are mainly for uhf
   /
5857
old and new methods for designing composite high frequency filter
circuits and their application to filter circuits with low relative
bandwidth  correction to paper abstracted in of january
   /
5858
nonlinear filters  comment on of and authors reply
   /
5859
electromechanical filters  design and performance data are presented
for if filters for the frequency range of the type comprising metal
plate resonators interconnected by pairs of fine metal wires
   /
5860
a general tchebycheff rational function  the derivation is described
of a function useful for the design of low pass filters
   /
5861
electronic audio bandpass filter  a narrow band filter with centre
frequency adjustable from to is obtained by including a phase inverter
rejection circuit in the negative feedback circuit of an audio amplifier
   /
5862
attenuator design  a chart is given for the design of constant resistance
types of attenuator
   /
5863
some not necessarily linear poles  composed of linear poles and in
some other poles linear relations exist between the voltages and
the currents and the resulting impedance matrix is symmetrical  a
generalization to include nonlinear relations is given by the condition
that must be symmetrical in and where is the pd between the and the
zeroth terminal and is the current flowing into the terminal  examples
and properties of such poles are given
   /
5864
the use of admittance diagrams in oscillator analysis  discussion
on of
   /
5865
a new type of rc oscillator  a circuit requiring a much smaller amount
of valve amplification than the usual phase shift oscillator uses
a specially designed twin t feedback network
   /
5866
block diagram analysis of vacuum tube circuits  the method is illustrated
by analyses of an amplifier with current feedback from the cathode
circuit and a phase shift oscillator
   /
5867
amplitude variations in a frequency modulated oscillator  analysis
indicates how unwanted am is produced when fm is accomplished by
varying the capacitance in a negative resistance oscillator circuit
a numerical example is given
   /
5868
the design of the eccles jordan circuit  design formulae are derived
from a fundamental analysis of the circuit  their application is
illustrated in the design of a high stability flip flop circuit using
a valve
   /
5869
the electronic switch  an analysis of the operation of square wave
generators
   /
5870
bi stable multivibrator analysis  continuation of paper abstracted
in of april  the operational calculus is used to analyse the eccles
jordan flip flop circuit
   /
5871
control of glow discharge triodes by means of very small currents
a discussion of the desirable characteristics of a valve suitable
for the generation of sawtooth oscillations using a grid cathode
capacitor of value between and and a grid control current as low
as  the essential design points are small cross sectional area of
the discharge space high current density at low currents short ion
transit times and large difference between the striking and the operating
potential  these are achieved by arranging a wire point control
electrode close to the cathode
   /
5872
the efficiency of frequency multipliers using detector circuits
an analysis is made of the harmonic frequency power obtainable in
an oscillatory circuit connected to a generator via a detector whose
characteristic is represented approximately by a hyperbola  for harmonics
of fourth and higher orders the calculations become very difficult
it cannot be assumed that for any given harmonic the power is less
than for the next lower harmonic
   /
5873
design of wide band tuned amplifiers  amplifiers with schienemann
butterworth and tchebycheff band pass characteristics are considered
in detail and formulae design curves and numerical examples are given
   /
5874
loudspeakers and amplifiers for use with stereoponic reproduction
in the theater  a brief description of equipment and cinema installations
   /
5875
the coaxial line amplifier
   /
5876
dc amplifiers  a survey paper with references
   /
5877
investigation of the effect of unbypassed screen grid resistors on
amplification factor  a calculation is made of the negative feedback
introduced by unbypassed resistors in the screen grid lead this arrangement
is usual in dc amplifiers  experimental results confirming the
theory are presented
   /
5878
an amplitude stabilized transistor oscillator  an af oscillator using
two junction transistors in push pull class c operation has its amplitude
stabilized to within over wide ranges of supply voltage loading
and temperature by comparing the output with a stable reference voltage
obtained from a junction diode operated at breakdown
   /
5879
distributed amplifiers some new methods for controlling gain frequency
and transient responses of amplifiers having moderate bandwidths
distributed amplifiers of moderate bandwidths for steady state applications
may be constructed for almost constant gain up to or of cut
off by methods including the insertion of extra sections into the
use of networks whose image impedance at a shunt capacitance point
falls to zero at the cut off frequency  for waveform amplification
the use of m derived low pass networks with added resistance elements
is suggested  the image delay is then almost constant over of the
non dissipative pass band ad the image attentuation varies in approximately
gaussian fashion with frequency over most of the pass band
in this second case the maximum useful number of valves per stage
is five
   /
5880
development of a high fidelity preamplifier for use in the recording
of bioelectric potentials with intra cellular electrodes  the cathode
follower circuit conventionally used to minimize the time constant
of the recording system is discussed and its shortcomings are analysed
an improved circuit using positive feedback is described
   /
5881
gain stability of feedback amplifiers  by proper choice of the phase
single of the loop gain either the magnitude or the phase angle of
the amplifier gain may be made independent to a first order of changes
in the active elements  th general theory is developed  results obtained
with an experimental amplifier show that over a narrow frequency
range the unit can be made as stable as the passive components in
the feedback network
   /
5882
a low frequency selective amplifier  analysis similar to that for
a simple resonant circuit is presented for a feedback amplifier
design and performance of an amplifier with a resonance frequency
of about are outlined
   /
5883
a minimal noise preamplifier for proportional counters and similar
applications  a negative feedback amplifier is described which is
linear over an input range of db  the maximum gain is and is attained
over a frequency range of about  signals of can be recognized
   /
5884
fast response of magnetic amplifiers
   /
5885
instability of self saturating magnetic amplifiers  digest of paer
to be published in  differences between the major and the minor hysteresis
loops of hipernik and their importance in dc triggering are discussed
   /
5886
gain stabilized transistor amplifier  gain is stabilized by using
an unbypassed resistor in the emitter circuit of a junction transistor
   /
5887
dc amplifier employing junction type transistors  temperature sensitive
resistors and junction diodes are used in conjunction with compensating
networks to eliminate drift effects  a two stage amplifier circuit
having a drift in hours at room temperature is described
   /
5888
building and using dielectric amplifiers  a detailed account is given
of th process developed at the national bureau of standards for preparing
the capacitors used in dielectric amplifiers  a two stage voltage
amplifier and an output stage capable of driving a loudspeaker are
described
   /
5889
low temperature electronics  a survey is made of the temperature
dependence of noise and resistance over a range of temperatures approaching
absolute zero  practical applications of the results of low temperature
research are discussed
   /
5890
on statistical estimation in physics
   /
5891
wave propagation in stratified media at normal incidence and application
to transmission line theory electric waves optics acoustics wave
mechanics an mechanical and electrical quadripoles  a comprehensive
analyse with numerous references
   /
5892
step by step transition from wave optics to ray optics in inhomogeneous
anisotropic absorbing media part solution of the equations for wave
normal and refractive index by wbk approximation  ray optical reflection
and alternation  the equations given in part of are solved  the existence
of particular points is established for which the transition canot
be made
   /
5893
the mechanism of electroluminescence part theoretical considerations
an account based on destriaus treatment attributing the phenomena
of electroluminescence to collisions of field accelerated electrons
in the conduction band references
   /
5894
rigorous analysis of the diffraction of electromagnetic waves by
strip gratings  a solution which is valid without restriction on
wavelength angle of incidence polarization or grating constants is
obtained in the form of tw fredholm integral equations of the first
kind of the same structure as those derived to represent diffraction
by slotted diaphragms in rectangular waveguides
   /
5895
a collective description of electron interactions part coulomb interactions
in a degenerate electron gas  part of april
   /
5896
a collective description of electron interactions part electron interaction
in metals
   /
5897
contact electrification  the observed phenomena are described and
various explanatory hypotheses are discussed  effects of static and
methods of c eliminating them are indicated  references
   /
5898
some measurements on a not selfsustaining gas discharge with an axial
magnetic field  report of investigations of the potential distribution
inside the central arc column of the discharge  the experimental arrangement
consists of a cylindrical anode with a filamentary cathode at
one end and a reflector at the other and a hot probe  with electronegative
gases deep troughs of negative potential are observed with electropositive
gases the central plasma potentials are still negative in
relation to the anode
   /
5899
ions and barriers in electric discharges  report of investigations
on the effect of injecting ions into the spark gap and of the effectiveness
of paper screens in blocking the ions
   /
5900
a condition on uniform field breakdown in electron attaching gases
the form of the curve relating t to at breakdown where e is the field
strength p the pressure and d the electrode separation indicates
the existence for high values of pd of a value of ep below which
breakdown does not occur  a study of the equation for steady state
current in electron attaching gases suggests that this limiting value
is nearly that for which the ionization and attachment coefficients
are equal this is confirmed experimentally
   /
5901
development of the theory of the positive column at low pressures
part
   /
5902
dioptrics of electron and ion beams with circular principal paths
   /
5903
secondary emission due to bombardment of metallic targets with multiple
charge ions  an experimental investigation of the dependence of the
coefficient of secondary emission on the energy of the ions  sb bi
and te targets were bombarded with sb bi and te ions respectively
and ni targets with na ba and ca ions  the results are shown graphically
   /
5904
the motion of electrons in two combined magnetic the motion of electrons
in two combined magnetic fields  the focusing properties of the field
of a homogeneously wound toroid have been investigated of  analysis
is now given for the case when this field is combined with a homogeneous
field perpendicular to the plane of the toroid
   /
5905
work function of clean and of oxygen coated au pt and pd based on
the contact potential difference with respect toag  values of the
work function were found to be up to higher for the oxygen coated
than for the clean surfaces
   /
5906
auger peaks in the energy spectra of secondary electrons from various
materials  measurements on c be al ni cu ba pt and oxides of some
of these are reported a description is given of the highly sensitive
apparatus used  characteristic peak due to auger electrons emitted
as a result of absorption of a valence electron by an excited x ray
level were observed for all these materials  the structure exhibited
by the peaks is related to the energy distribution of electrons in
the valence band and complements that observed in soft x ray emission
excitation of auger peaks by low velocity electron beams provides
a method of investigating surfaces
   /
5907
generalized ionization formula for a plasma  a formula is derived
which includes as special cases sahas equation the gas cloud ionization
formula and the solar corona ionization equation
   /
5908
the field along the axes of symmetry of equal semi infinite rectangular
magnetic pole pieces  the method of conformal representation is used
the field along the axes of symmetry is calculated for a number of
values of the ratio of the width of the pole pieces to the distance
separating them  expressions for the potential function are also
given
   /
5909
magnetic behaviour of a linear atomic chain at the absolute zero
point for positive exchange integral  a calculation of the magnetic
moment indicates that the linear atomic chain is not spontaneously
magnetizable
   /
5910
on the statistical mechanics of matter in an electro magnetic field
part derivation of the maxwell equations from electron theory  an
ensemble averaging method is used
   /
5911
magnetic field due to a direct current traversing a solid conductor
of arbitrary shape  application to a cylindrical conductor  laplaces
law usually known as biot and savarts law is shown to be more suitable
than amperes magnetic sheet concept as a basis for deriving formulae
for the magnetic field of a conductor  the vector potential is introduced
   /
5912
cerenkov effect at microwave frequencies  radiation of power excited
by a beam bunched at and travelling close to the surface of a polycrystalline
dielectric has been detected
   /
5913
on the diffusion of decaying particles in a radial electric field
an analysis is made of the diffusion of charged particles in a radial
field in which the intensity is distributed according to an inverse
square law
   /
5914
electronic polarizabilities of ions in crystals
   /
5915
interaction of a nonrelativistic particle with a scalar field with
application to slow electrons  in polar crystals
   /
5916
capacitance of a spherical capacitor  in a practical spherical capacitor
the capacitance is not given exactly by the theoretical formula because
the outer sphere has an aperture  upper and lower limits are derived
for the magnitude of the error involved
   /
5917
radio frequency emission from cosmic ray electrons  theory developed
by schwinger is used for the quantitative investigation of the intensity
and spectral distribution of rf radiation from cosmic ray electrons
in interstellar magnetic fields  an upper limit is deduced for the
density of an electron component of the cosmic radiation
   /
5918
the strength of meteoric echoes from dense columns  calculations
taking into account the refractive effects produced by ionization
distributed at radii t radii greater than the critical density radius
have been made for large highly ionized trails using geometrical
optics and ray tracing methods  the computed maximum radiated power
from a diffusion formed trail is only of that calculated on the critical
density radius method
   /
5919
meteor echo duration and radio wavelength  the durations of radar
echoes from meteors have been observed simultaneously on and and
also on and m  the ratio of durations on two wavelengths decreases
with increasing duration by a factor of two over the observed range
deviating significantly from the accepted square law of wavelengths
plotting the log of the ratio against the log of the duration yields
two straight lines of different slopes one in the short duration
range and the other applying to the longer echoes  general empirical
formulae are developed to predict the echo duration on one radio
equipment in terms of the duration of the same echo recorded by another
apparatus of different sensitivity and wavelength
   /
5920
baileys theory of sunspot noise  a discussion of the exchange of
energy between the drifting electrons and the wave radiated from
a transient disturbance is given which is more general than baileys
of and which shows that amplification can occur under certain conditions
consideration of a sunspot model having axial symmetry leads to
the conclusion that amplification will occur only in exceptional
regions
   /
5921
the equations for a problem arising in dungeys investigation of baileys
theory of sunspot noise  see above
   /
5922
the magnetic field strength in sunspots
   /
5923
theories of solar phenomena depending on sunspot fields moving in
the chromosphere and corona  theories advanced by giovanelli and
various other workers are found to be untenable when mechanical reactions
between the magnetic fields and the conducting gas are taken into
account
   /
5924
a family of solutions of the magneto hydrostatic problem in a conducting
atmosphere in a gravitational field  a theoretical study of the equilibrium
conditions in a quiescent solar prominence  a simple model is
obtained
   /
5925
ionospheric and geomagnetic effects of solar flares  geomagnetic
crochets observed t amberley and apia new zealand between and simultaneously
with dellinger fadeouts are considered in relation to subsequent
magnetic and ionospheric disturbances  their hourly and seasonal
frequencies are examined and their augmentation of the normal diurnal
inequality verified
   /
5926
the h radiation from solar flares in relation to sudden enhancements
of atmospherics on frequencies near
   /
5927
radio astronomy part results of observations of cosmic radio noise
sources  a survey with references
   /
5928
a survey of localized radio sources in the northern hemisphere  report
of a survey at a wavelength of made with the jodrell bank aerial
system  a marked concentration of the intense sources near the galactic
plane was found the distribution of the weaker sources may be more
nearly isotropic
   /
5929
a radio survey of the milky way in cygnus cassiopeia and perseus
report of a survey at a frequency of using the jodrell bank beam
aerial and covering the region between and between and  the isophotes
of the absolute intensities are shown
   /
5930
fine structure of the extraterrestrial radio source cygnus  observations
made at jodrell bank are reported
   /
5931
radio astronomy  see of january
   /
5932
the relation between earth currents and geomagnetic variations  a
comparison was made between the time variations of e and h where
e is the electric field and is the resultant vertical component of
the geomagnetic variations  fair agreement between the curves was
obtained
   /
5933
rapid periodic fluctuations of the geomagnetic fld part  a new analysis
is made of observational data mainly from eskdalemuir  the type of
c fluctuation changes at sunset from a continuous flux of disturbance
to a comparative quiet punctuated by a short damped wave train  a
definite fine structure is observed in the spectrum of the daytime
fluctuations
   /
5934
the analysis of ionospheric records ordinary ray part  tables presented
enable the effect of the earths magnetic field to be taken into account
when using the method of analysis of ratcliffe of appleton and beynon
of  using these tables theoretical curves can be constructed for
a parabolic or a linear distribution of ionization and for all magnetic
latitudes up to about
   /
5935
variations of d layer attenuation at  results of daytime reflection
coefficient measurements made over a period of several years are
analysed  the noon value of the attenuation is neper in winter nearly
neper in summer  though the scatter of values is considerably greater
in winter than in summer the excessive absorption observed in winter
on short waves is not observed at this frequency  the influence of
the d layer on the propagation of atmospherics is discussed and the
attenuation variations are compared with those of geomagnetic activity
   /
5936
the contribution of solar x rays to e layer ionization  a brief description
of rocket experiments which provide positive evidence of soft
x rays in the ionosphere to an extent sufficient to account for all
the e layer ionization
   /
5937
electric currents in the ionosphere part the conductivity  the effective
height integrated conductivity of the ionosphere calculated on the
dynamo theory and taking account of inhibition of the hall current
due to polarization of the medium is greater than the pedersen conductivity
by a factor of at least and near the magnetic equator is further
increased by a factor of to  this calculation is shown to overestimate
the reduction in total current flow in the ionosphere due to the
shunting effect of the f region when the motion of the f region is
considered  the dynamo theory as presented here gives results in
agreement with observations and accounts in particular for the anomalously
large magnetic variations observed near the equator
   /
5938
electric currents in the ionosphere part the atmospheric dynamo
assuming semidiurnal tidal air flow the atmospheric dynamo problem
is solved the ionosphere being divided into three regions each of
appropriate conductivity  compared with calculations assuming pedersen
conductivity alone effective results give a current system similar
in shape and phase though more intense and an electric field system
markedly different  an abnormally large east west current is found
at the equator
   /
5939
electric currents in the ionosphere part ionization drift due to
winds and electric fields  the motion of a cylinder of ionization
of density differing from that of the surrounding medium tends to
be such that the ionization density is greatly increased over part
of its surface and diminished over another part  the significance
of this result in relation to sporadic e ionization and to long duration
meteor trails is pointed out  formulae are derived for the horizontal
and vertical drift of ionization at all atitudes  graphs are given
which permit derivation of the true wind or field in a given ionosphere
region from experimental observations of the drift velocities
   /
5940
semidiurnal currents and electron drifts in the ionosphere  the differential
equations of the dynamo theory for the ionosphere are solved
numerically under simplifying assumptions  the tidal amplification
estimated is about  for the solar tide the current system in the
e layer is in phase with the ground tide but for the lunar tide it
it in phase opposition  the calculated vertical electron drift is
in reasonable agreement with lunar tide observations  the calculated
horizontal electron drift agrees with observations on long duration
meteor trail echoes but the calculated phases are opposed to those
obtained from fading measurements indicating that the latter refer
to air movements and not to electron drift
   /
5941
solar tides in the f region from the study of night time critical
frequencies  night time critical frequency variations at ionospheric
stations are analysed by season and by latitude for semi diurnal
solar tidal terms  the amplitude and phase of the vertical drift
velocity of electrons so found are consistent with accepted tidal
theory and an estimate of the height gradient of the vertical drift
is obtained  two parallel analyses are made on the alternative assumptions
that decay proceeds according to a recombination law or to an
attachment law  the low values found for the decay coefficients preclude
any decision as to which of these two decay processes is actually
operative
   /
5942
anomalies of the ionosphere critical frequencies during a solar eclipse
soundings made at rome during the partial eclipse of february are
reported  electron concentration minima were observed before and
after the eclipse and at the maximum phase  the cause of the first
and last of these maxima is assumed to reside in the zone outside
the visible disk of the sun
   /
5943
determination of the location of the ionospheric current system responsible
for geomagnetic effects of solar flares  the height of the flare
current system is calculated by a method depending on the time of
maximum intensity of a geomagnetic flare effect and the enhancement
of electron density at the relevant level  if the flare current system
forms part of the current system its height is but if it is independent
its height is about km
   /
5944
measurements of winds in the upper atmosphere by means of drifting
meteor trails  description of the doppler radar system and the associated
equipment
   /
5945
measurements of wind in the upper atmosphere by means of drifting
meteor trails part  results of measurements made during oct dec by
the method described in above are discussed  winds at heights between
and are in general horizontal with a prevailing direction in october
towards the north east and in november and december towards the east
the hour and hour harmonic components represent anti clockwise rotation
of the wind vectors the hour component being consistent with the
phase of a semi diurnal tidal wind as deduced from barometric oscillations
over the height range investigated the direction of the wind
remains the same but the mean velocity increases with height
   /
5946
the measurement of ionospheric absorption using observations of cosmic
radio noise  ionospheric absorption is specified by the ratio expressed
in decibels of p the received cosmic noise power to p the power that
would have been received in the absence of absorption  from about
a years observations of cosmic noise a standard curve of sidereal
time can be drawn for all aerial directions  analysis of records
made at hornsby nsw from june to show that two main components due
to absorption in the f and d regions respectively can be distinguished
   /
5947
the waveforms of atmospherics  a review of research during the preceding
fifty years on lightning and on atmospherics showing the relation
between the two phenomena
   /
5948
harmonic fields in the propagation of long electric waves round the
earth and lightning waveforms
   /
5949
the propagation of very long electric waves round the earth and atmospherics
   /
5950
the application of statistical methods to servo mechanisms  the optimum
transfer function for the desired response to a stationary random
input signal containing noise may be determined by the wiener lee
method  in general when applied to servo mechanisms design the output
will not necessarily have zero steady state error  in order to overcome
this disadvantage constraints may be applied in the wiener hopf equation
such that any of the error coefficients of the servomechanism are
zero and at the same time the output is optimized  it is also possible
to include prediction differentiation or integration of the input
function as desirable outputs
   /
5951
series operation of a glow discharge tube and a barretter  the replacement
of the series resistor by a barretter results in improved stabilization
the operation of the type glow discharge tube with type barretter
was investigated and the batch variations of the type barretter characteristics
were examined
   /
5952
stabilizer for alternating voltages  the design of a biased reactor
arrangement having good frequency independence and satisfactory speed
of operation is discussed
   /
5953
a stable source of high voltage  a voltage regulator suitable as
a voltage reference at about with current up to several milliamperes
is described  with the temperature controlled to within the e output
is stable to within part in over hours  effects of varying magnetic
fields gauss are negligible
   /
5954
aircraft protection from thunderstorm discharges to antennas  the
protection unit described consists of a capacitor in the aerial feeder
lead together with a spark gap in parallel with a resistor connected
between the aerial side of the capacitor and the fuselage  a peak
current recorder in the form of a steel strip magnetized by the current
flow is included  units of this type have been tested for over two
years in commercial airliners
   /
5955
an analogue computer for the solution of the radio refractive index
equation
   /
5956
automatic beam current stabilization for williams tube memories
one of the storage points in the memory tube is used as a test point
at regular intervals this is cleared and recharged and the output
is sampled the beam current being adjusted to keep the sampled output
at a constant level  the whole operation takes to complete  circuit
details are given
   /
5957
a note on calculating the total impedance of impedors connected in
parallel  three methods one involving use of a desk calculating machine
and another use of a linear nomogram are compared and contrasted
from the point of view of speed and accuracy
   /
5958
nonlinear distortion of a random signal  application to frequency
modulation  analysis is based on the instantaneous statistical properties
of a random signal the energy spectrum for a given bandwidth being
determined from the appropriate correlation functions  application
of the method is illustrated in the case of fm when propagation time
is considered  since the calculation takes account of intermodulation
products over a complete frequency band the method has advantages
over that based on intermodulation of discrete frequencies
   /
5959
pulse permeability and losses in magnetic materials subjected to
rectangular dc pulses
   /
5960
transductor with high impedance control winding termination  the
dynamic behaviour of this transductor is represented by equations
similar to those for a transductor with a low impedance control winding
termination of
   /
5961
matrix analysis of linear time varying circuits
   /
5962
ire standards on circuits definitions of terms in the field of linear
varying parameter and nonlinear circuits  standard
   /
5963
a coaxial magic t  the basic design consists of a coaxial line t
junction including a shielded loop whose axis is located at the centre
of the t the operation is similar to that of the hybrid coil or the
waveguide magic t  two modifications are described one using direct
coupling between the loop and the loads  standing wave characteristics
of experimental models for operation at wavelengths of about cm are
given a swr can be obtained over a frequency band of about  application
to phase measurements is described briefly
   /
5964
filter helix travelling wave tube part the filter helix a new circuit
element for travelling wave amplifiers and oscillators
   /
5965
the properties and manufacture of piezoelectric quartz crystals
   /
5966
thickness shear and flexural vibrations of contoured crystal plates
equations of motion expressing approximately and separately the thickness
shear and flexural modes are derived from data on the coupled
modes for a plate of uniform thickness of and of mindlin  these equations
are applied to the case of a plate of double wedge shape and a
plate with bevelled edges  results support the finding that thickness
shear motion is localized at the centre flexural motion at the edges
   /
5967
thickness shear vibrations of piezoelectric crystal plates with incomplete
electrodes  the method developed in above is applied to determine
the influence of electrode length on thickness shear frequencies
for a partially coated crystal these frequencies depend on the coupling
between the coated and uncoated portions considered as separate systems
   /
5968
suppression of overtones of thickness shear and flexural vibrations
of crystal plates  analysis showing how electrodes coated on the
surfaces of thickness shear plates may be shaped so that only one
resonance mode is excited
   /
5969
derivation of equivalence theorem of a weakly coupled electromagnetic
cavity resonator system  a general proof of the equivalence between
a system of weakly coupled cavities and a system of coupled resonant
lcr circuits is derived from maxwells equations by means of a first
order perturbation calculation  the frequency dependence of the system
is deduced from the equation of state  the case of two coupled cavity
resonators is considered in an example
   /
5970
calculation of the resonant properties of electrical cavities  the
method described is based on measurements made on a model in a electrolyte
tank  calculated values of resonance wavelength and q are in
good agreement with directly measured values
   /
5971
characteristic functions of real resonators  orthogonal characteristic
functions for a piecewise inhomogeneous one dimensional system are
considered in relation to resonators with energy losses at the boundaries
the analysis provides an explanation of previously published
experimental results
   /
5972
an iterative method for network synthesis  the numerical method described
is based on the complex critical frequencies of the insertion
loss function  applications to networks with up to four poles and
four zeros and to a crystal filter are illustrated
   /
5973
synthesis of transfer functions with poles restricted to the negative
real axis  comment on of and authors reply
   /
5974
radio frequency phase difference networks a new approach to polyphase
selectivity
   /
5975
quasi distortionless filter functions  the quasi distortionless filter
network function is specified by expressing the input and output
functions as time power series and equating their coefficients  such
filter functions are derived and discussed
   /
5976
the direct method of filter and delay line synthesis  extension of
previous work of  the direct method consists in postulating an indefinitely
recurring network in which each recurring element is coupled
to all elements of the network and in determining the values of these
elements and of their indefinitely extended couplings which will
yield the exact phase characteristics desired within the exact pass
band desired  examples are given of the application of the method
to the design of ideal band pass filters
   /
5977
the synthesis of reactance networks consisting only of rejector circuits
in series by the method of partial networks  the modification required
in a filter network with given resonance and anti resonance frequencies
in order to introduce a further prescribed resonance or antiresonance
frequency is determined  numerical examples illustrate the method
which is also applied to the reduction of the number of resonance
frequencies and to a mechanical oscillator
   /
5978
the historical development of filter theories
   /
5979
elementary ladder type filters  a system of classification of conventional
ladder type filters based on image parameters is described  an
elementary filter is defined as a network with two prescribed image
impedances and minimum attenuation  these are generally composed
of conventional half sections but in certain cases particularly for
band pass filters synthesis involves sections with three branched
impedances which cannot be resolved into matched half sections  formulae
with examples of networks for low pass high pass band pass and band
stop filters are given in an appendix
   /
5980
rc active filters  a type of filter is described in which the active
element is a negative impedance converter using transistors of  the
number of capacitors required is only equal to the total number of
reactance elements in the corresponding lc filter  theory is given
and tests on low pass high pass and band pass filters are reported
   /
5981
impedance transformations in band pass filters  the design of band
pass impedance transforming filters is derived from the equivalence
between an asymmetrical band pass filter and a symmetrical section
plus an ideal transformer
   /
5982
design of a simple band pass amplifier with approximate ideal frequency
characteristics  the application of the pole and zero method of synthesis
is illustrated
   /
5983
fm transient response of band pass circuits  a general formula is
derived for the instantaneous deviation of output frequency resulting
from a step change of input frequency  calculations are presented
for large frequency shifts in a single tuned circuit and for small
frequency shifts in amplifiers with various numbers of tuned circuits
for small input steps near the middle of the pass band the transient
response is the same for fm as for am  stagger tuning gives rise
to overshoot but the extent of this is small if the amount of stagger
is no more than enough to provide maximally flat response in the
steady state
   /
5984
one design method of band pass filter for vhf  design formulae for
band pass filters constructed of two wire and coaxial cables are
derived and numerical examples are given  the theoretical and experimental
results are in fair agreement
   /
5985
hereditary dynamic systems with discontinuities  the characteristics
distinguishing nonlinear from linear oscillations are examined  a
class of dynamic systems termed discontinuous is defined cases are
discussed for which poincares topological methods can be used to
determine the periodic solutions and the stability  such systems
are included in the larger class of hereditary systems defined by
volterra ie systems whose operation is affected by their previous
history
   /
5986
single stage phase shift oscillator  a method of design is developed
in which the phase shifting network contains an arbitrary number
of rc or cr cells and the value of the first series impedance is
half that of the others  simple formulae are derived for the network
impedance and oscillation frequency
   /
5987
transistor oscillators  the self oscillation conditions and frequency
deviation characteristics of a three point transistor oscillator
are derived by analogy with the retarding field oscillator and a
comparison is made with measured characteristics of point contact
and junction type transistor oscillators  various circuits are examined
from the point of view of suitability of application of the two types
of transistor  the discussion is limited to the frequency range below
cut off
   /
5988
the audio frequency negative feedback amplifier as a filter circuit
a single stage rc feedback amplifier is represented by an equivalent
damped parallel lc circuit and a locus diagram for amplification
is constructed  the method is applied to a two stage amplifier an
expression analogous to form factor in filter theory being derived
in terms of feedback ratio  this is useful for determining the effect
of feedback on the frequency characteristic in af amplifier design
   /
5989
bandpass amplifiers  a design method is presented based on the required
overall gain half power bandwidth and centre frequency of the pass
band  the amplifier considered is composed of a number of identical
groups each comprising one or more amplifying stages and having a
maximum flatness frequency response  conditions for maximum possible
gain are found  regeneration due to anode grid capacitances is discussed
the amount of distortion introduced into the frequency response is
related to a regeneration coefficient  when is sufficiently large
oscillations occur  stability conditions for single tuned and stagger
tuned and stagger tuned amplifiers are derived
   /
5990
distributed amplifier theory
   /
5991
a new transformerless amplifier circuit  four valves in a bridge
circuit are driven in appropriate phase and amplitude so as to deliver
equal power to a common load  no dc flows through the load negative
feedback is easily applied  a and an amplifier are described response
characteristics are flat over the audio range at all levels of operation
the unit weighs including power supply and pre amplifier
   /
5992
magnetic amplifier performs analytical operations
   /
5993
audio automatic volume control systems  applications of a vc are
noted and various circuits are reviewed  methods of eliminating audible
thump occurring on application of a direct control voltage of deriving
the control voltage and of reducing time delay are discussed  measurement
techniques are outlined
   /
5994
the new compressor expander system of the french post office  the
new unit has improved operating characteristics and is less than
one quarter the size of the former type of et al  two si diodes replace
the rectifiers in the potentiometer system and two ge diodes the
double diode valve in the detector unit  other valves are replaced
by miniature types  performance tests are reported
   /
5995
proposal for a new aether drift experiment  an experiment using standing
microwaves is outlined
   /
5996
deductions regarding the constitution of light energy  a discussion
based on the results of experiments previously reported of  the field
associated with a particle of light as defined by planck is nonoscillatory
the frequency associated with the light being due to the circulation
of em energy in the particle
   /
5997
the mechanism of electroluminescence part applications to the experimental
facts  theory previously developed of may is used to interpret
observed phenomena including temperature and frequency effects fluctuations
of brightness corresponding to field alternations initial rise
of brightness and surface effects  good crystallization abundance
of luminescence centres and donor levels and absence of other defects
are conditions favouring the production of electroluminescence  various
theories of the phenomenon are compared in an appendix
   /
5998
on a property of a family of equiangular spirals and its application
to some problems of wave propagation
   /
5999
the diffraction of waves in passing through an irregular refracting
medium  a relation is derived between the angular power spectrum
of waves emerging from a thin diffracting screen random in two dimensions
and the auto correlation function describing the irregularities
of the field as it emerges from the diffracting screen  the special
case of an isotropic screen characterized by an auto correlation
function which depends only on distance and not on direction is discussed
for normal and oblique incidence  multiple scattering of waves
caused by volume irregularities of the dielectric constant is considered
the angular power spectrum and the auto correlation function describing
the irregularities of the diffraction field caused by multiple
scattering in a thick slab are determined  the results are compared
with those obtained by hewish of for a thin phase changing screen
the results are discussed in terms of problems arising in the study
of radio wave propagation
   /
6000
a note on uniqueness proofs for boundary value problems in potential
theory and steady heat conduction  by allowing the boundary to tend
to infinity in two directions and considering the problem in a semi
infinite region it is possible to prove uniqueness by classical methods
for a very large class of boundary conditions
   /
6001
variational methods for problems in resistance  schwingers variational
methods are used to calculate upper and lower limits for the resistance
of a cylinder with a specified transverse distribution of potential
at one end
   /
6002
the evaluation of the surface impedance in the theory of the anomalous
skin effect in metals  a method is described for obtaining series
expansions for the integrals which represent the surface impedance
   /
6003
note on the quantitative development of the discharge characteristic
   /
6004
investigation of ball lightning by means of models  experiments with
gas discharges are described
   /
6005
ussr research on magnetism  a brief historical survey with comprehensive
bibliography
   /
6006
effect of the surface on the magnetic properties of an electron gas
the energy levels of free electrons confined in a finite cylindrical
box with a uniform axial magnetic field are computed using the wkb
approximation the form of approximation appropriate to various boundary
conditions is discussed  the results are used to calculate the susceptibility
of the system
   /
6007
on reciprocity theorems in electromagnetic theory  five different
types of sources of em fields are considered and the corresponding
reciprocity theorems stated
   /
6008
a scalar representation of electromagnetic fields  it is shown that
in a region which is free from currents and charges any em field
may be rigorously derived from a single generally complex scalar
wave function  the momentum density and energy density defined in
terms of this function differ from those given by the usual expressions
but the differences disappear on integration over any arbitrary macroscopic
domain
   /
6009
induction of currents by moving charges  an analysis is made of the
field due to a charge moving between a pair of parallel disk electrodes
connected externally by a conductor  a general expression for the
current flowing through the conductor is derived in terms of the
electrode radius and separation and the velocity of the charge  a
periodic discharge could be obtained with particular values of and
u
   /
6010
electromagnetic waves emitted on detonation of explosives  small
electrical disturbances detected incidentally while using explosives
to produce sharp stress pulses were later investigated separately
the effect was displayed on a high speed cro  the potential of a
wire probe reached a maximum after about and then decayed to zero
the effect is probably due to the production of positive and negative
ions having different mobilities
   /
6011
vector modifications inherent in the doppler effect for waves propagated
in a dielectric medium  the propagation of plane em waves in a moving
medium is characterized by four vectors as compared with two for
a stationary medium because the directions of the electric and magnetic
fields no longer coincide with the respective inductions  relations
between these vectors are derived and their physical significance
is discussed
   /
6012
the electromagnetic transmission characteristics of the two dimensional
lattice medium  a theoretical investigation is made of systems with
obstacles arranged to form a regular lattice in planes perpendicular
to the direction of propagation the obstacles having elliptical cross
section  an examination is made of the influence of obstacle size
shape and spacing and of the wave polarization on the transmission
characteristics  no restriction is introduced as regards the size
of the obstacle in relation to  the theory is relevant to problems
of microwave lenses and transmission circuits of travelling wave
valves
   /
6013
microwave diffraction measurements in a parallel plate region  diffraction
of a plane or a cylindrical wave by wedges covered with silver
foil was investigated experimentally by a probe method the wedge
the line source and the probe were located between two large parallel
duralumin sheets spaced in apart  the measured values of field strength
are compared with values derived from previously published theory
   /
6014
radiation from a line source adjacent to a conducting half plane
expressions for the field are obtained in terms of tabulated functions
by using an alternative method of analysis to that of harrington
   /
6015
the fields of a line source of current over a stratified conductor
expressions for the electric and the magnetic fields are derived
assuming the to be infinitely long and parallel to the conductor
at large distances the results can be generalized to apply to any
source of horizontally polarized waves situated on the surface of
a half space consisting of an arbitrary number of layers
   /
6016
absorption of microwaves in gases  absorption coefficients in the
cm waveband were determined for ammonia ethyl alcohol and acetaldehyde
at a pressure of mm hg and for methyl iodide and acetone at cm hg
and cm hg respectively
   /
6017
the decomposition of thin films on bombardment with slow electrons
the threshold energies of the bombarding electrons were determined
for the onset of electron absorption decomposition and secondary
emission  the films investigated included and the alkali halides
the experiments were carried out using diode or triode valve systems
with an oxide coated cathode operated at as the source of the bombarding
electrons
   /
6018
radio astronomy part radiolocation of meteors  a review of measurement
techniques and results with a note on local ionization effects of
meteors
   /
6019
the effect of radar wavelength on meteor echo rate  theory is given
which includes the effects of high electron density the linear rate
of trail formation and the initial column radius on the meteor echo
power and hence on the number of echoes received  the theories of
lovell and clegg of and others are discussed critically  a comparison
with experimental results is made
   /
6020
a note on solar terrestrial relationships  corpular emission from
the invisible solar disk and deflection of the particles into certain
trajectors could account for the lack of correlation between particular
solar and geophysical phenomena
   /
6021
identification of sunspots  previous work of indicates a statistical
correlation between spots on opposite hemispheres during successive
sunspot cycles  analysis of sunspots between latitude and appears
to support this view  a number of sunspots are identified as being
produced by the same original disturbance in the solar core the mechanism
is explained on the basis of the magneto hydrodynamic theory of
sunspots
   /
6022
position and identification of a bright extended radio source in
gemini  more accurate observations are reported on a previously detected
source of
   /
6023
the radio brightness distributions over four discrete sources of
cosmic noise  the experimentally determined isophotes obtained from
measurements with a variable aerial spacing radio interferometer
at are compared with the optical features of the nebulae
   /
6024
galactic radiation at radio frequencies part the sea interferometer
the factors governing the interference pattern of a lloyds mirror
type of interferometer at frequencies between and are discussed and
three systems for reducing the effect of background noise are described
   /
6025
galactic radiation at radio frequencies part low altitude scintillations
of the discrete sources  scintillations of four discrete sources
of altitudes from to were observed at frequencies in the range to
a strong correlation is established between the occurrence of scintillations
and sporadic e  part above bolton and slee
   /
6026
note on geomagnetic disturbance as an atmospheric phenomenon  possible
relations between ionospheric winds and atmospheric electric currents
associated with magnetic storms are briefly discussed
   /
6027
the immediate source of the field of magnetic storms  results of
a comparison of mean values of initial phase of magnetic storms at
huancayo cheltenham honolulu and san juan porto rico indicate that
major immediate sources of magnetic field changes during storms in
all phases are within or near the atmospheric region  see also above
   /
6028
a statistical survey of atmospheric index of refraction variation
survey of microwave measurements made at heights of over the pacific
ocean california and ohio using an airborne refractometer described
by crain and deam
   /
6029
an analogue computer for the solution of the radio refractive index
equation  a computer in use at the crpl comprises basic computation
in use at the crpl comprises basic computation circuits incorporated
in a bridge circuit  a turn potentiometer is modified so as to give
an approximately exponential variation of the resistance with the
shaft rotation corresponding to the curve of the saturated water
vapour term in the equation
   /
6030
irregularities in the ionosphere  electron clouds in both the e and
the f regions have been detected at vertical incidence by means of
the equipment described by banerjee and roy of  photographs of typical
echo records are shown the power and persistence of the echoes are
discussed
   /
6031
recombination and diffusion and spread echoes from the ionosphere
the inclusion of a diffusion term in the differential equation of
layer formation to account for ionization due to the influx of charged
particles leads to a solution in terms of a doubly periodic elliptic
function  this solution indicates the possibility of a periodic variation
of ionic density within the f layer such as to account for spread
echoes which have been observed  layers produced by ultra violet
radiation are many wavelengths thick those due to particle ionization
are only two or three wavelengths thick and are embedded in the background
of ionization  the existence of auroral curtains provides further
evidence of ionization by particles
   /
6032
origin of the e layer of the ionosphere  the electron densities for
the and f layers resulting from photo ionization of molecular and
atomic oxygen are calculated on the basis of the work by moses and
wu on the distribution of o and of o in and above the oxygen dissociation
layer of and of  while the results are in reasonable agreement
with observations for the e layer it is not possible to account for
the observed value of recombination coefficient for the f layer by
any theory based on processes involving only oxygen atoms and molecules
   /
6033
method of determining the true height of the ionospheric layers part
application of the exact value of the refractive index ordinary ray
case  values obtained using the exact value of the refractive index
appleton hartree are somewhat higher than those obtained with the
approximate formulae used in part of
   /
6034
recombination in the f layers  the mechanism proposed by banerji
of april is critically discussed
   /
6035
further discussion of kelsos paper on a method for determination
of the distribution of electron density in the ionosphere  comment
on
   /
6036
correlation of magnetic auroral and ionospheric variations at saskatoon
analysis of measurements made between december and april  a connection
exists between the maximum elevation of auroral light above the northern
horizon and the maximum amplitude of variation of h  some types of
sporadic e reflecting layers appear more frequently during geomagnetic
disturbances
   /
6037
investigation of ball lightning by means of models  experiments with
gas discharges are described
   /
6038
on the production of glow discharges in the ionosphere by winds
a source of excitation of the airglow and aurora may be found in
the potential difference generated by zonal ionospheric winds cutting
the earths magnetic field  a return path of current flow or glow
discharge in the higher ionosphere appears plausible
   /
6039
radio echoes observed during aurorae and geomagnetic storms using
and waves simultaneously  observations made at kjeller in and at
tromsoe during early are reported  echoes are only received when
the aerial is directed towards the north the echo amplitude has a
maximum value when the aerial is directed horizontally and decreases
rapidly with increased elevation of the aerial  the results indicate
that there is no correlation between the position of visible aurorae
and echo range but that there is a correlation between the occurrence
of high e layer critical frequency and the reception of echoes  during
geomagnetic storms echoes on are observed only during the more severe
phases  scattering from the ground or sea reflected back vis an intense
e layer is advanced in explanation of the observations
   /
6040
step to frequency response transforms for linear servo systems  five
known methods for finding frequency response from a given graph of
linear mode step response are discussed  theory and practical computing
routines are given for a new method based on straight line segment
approximation to the given step response graph  approximate laws
relating cut off frequency and frequency and amplitude of maximum
response to the shape and and time scale of the step response are
derived  discrepancies between experimental results and those derived
from the theory are ascribed mainly to nonlinearity of practical
systems
   /
6041
electromagnetic shielding with transparent coated glass  the shielding
effectiveness of multilayer plane glass structures is investigated
by determining their transmission factor for plane em waves  three
types of glass are considered at frequencies up to  transmission
line theory is used in the analysis the coatings being represented
by shunting resistances  theoretical and experimental results are
compared  attenuations of db and more can be obtained with tolerable
loss of transparency
   /
6042
the electron voltaic effect in pn junctions induced by beta particle
bombardment
   /
6043
supply for precision measurement  a low impedance generator giving
a highly stable comprehensive supply over the frequency range is based
on a wien bridge oscillator with stabilized dc supplies
   /
6044
voltage stabilizers for microwave oscillators  analysis indicates
that the effect of variation of valve heater voltage in commonly
used stabilizers of is not serious in the case of series parallel
arrangements but may be serious where a single series valve is used
   /
6045
partial drift compensation in electronic dc analog computers for
differential equations  a method particularly suitable for computers
with time shared elements is described  the number of compensation
points can be much smaller than the number of drift sources  the
method is illustrated by describing the compensation of a machine
for computing direction cosines
   /
6046
analog computing by heat transfer  multiplier divider ac integrating
and differentiating circuits are described based on the use of a
thermal transducer  this transducer consists basically of a pair
of heater elements each one of which is in thermal contact with one
of a pair of temperature sensing elements mounted in a wheatstone
bridge circuit  appropriate application to the heater elements of
two electrical input signals creates a temperature difference proportional
to their product between the sensing elements
   /
6047
fosdic a film optical sensing device for input to computers  an instrument
is described for processing written records such as answers to
questionnaires  marks made with ordinary pen or pencil at special
locations on microfilm are converted are converted into electrical
pulses by means of a flying spot scanning system  the pulses are
recorded on magnetic tape for input to the computer  see also
   /
6048
fast acting digital memory systems  a survey of moderate ad high
speed storage techniques for digital computers
   /
6049
penetration of an electromagnetic wave into a ferromagnetic material
an investigation of the magnetization of metallic ribbon toroidal
cores with rectangular hysteresis loop used as computer storage elements
approximate solutions are obtained for the field inside the core
under different conditions of loading  theoretical and experimental
output waveforms show close agreement for high magnetizing force
and thickness of core material mil
   /
6050
ferromagnetic spinels with rectangular hysteresis loops  tests made
on materials of different composition show to be most suitable for
magnetic storage elements  for rings of outside diameter inside diameter
mil the coercive force is about oersteds and switch over time  rings
of outside diameter have a lower coercive force
   /
6051
servo control of the position and size of an optical scanning system
a method of controlling the position and size of a television type
raster relative to arbitrary references by means of four servo mechanisms
is described  one of the applications of such a system is that
of a reading device for punched cards  a system for reading any one
of a stack of cards without removing the selected card has been developed
using the servo controlled raster  the design of the servo mechanisms
for this application is described in detail
   /
6052
electronic circuit technique for a high speed computer  commonly
used computer circuit units based on a triode or ge diode are represented
by a symbol indicating the unit and its mode of operation  the
functions of different combinations of different combinations of
the basic units are listed and their application in a serial binary
scale computer is illustrated using the notation described
   /
6053
new flip flop chain circuits used in computers for counting to base
and base  modifications to the potter decade arrangement are described
   /
6054
an improved experimental iteration method for use with resistance
network analogues  a development of the method previously described
by liebmann of  the error signals for a number of network nodes are
displayed simultaneously on a cr tube screen so that it is always
possible to work on the worst error instead of making adjustments
cyclically
   /
6055
the mercury delay line storage system of the ace pilot model electronic
computer  discussion on of january
   /
6056
ime shared amplifier stabilizes computers  drift in the dc operational
amplifiers of analogue computers is reduced by connecting them periodically
to the output of an auxiliary stabilizing amplifier  the advantages
of using a direct coupled rather than a chopper type of amplifier
for this purpose are indicated  circuit details are described including
the switching and filtering arguments
   /
6057
metal ultrasonic delay lines  an experimental investigation was made
with the object of finding a metal o or alloy suitable for the transmission
of pulses at temperatures between and with a delay independent
of temperature  the effect of various constructions crystal attachment
methods and materials and treatment of the delay line material was
investigated the results are tabulated and shown graphically  an
isoelastic iron alloy containing cr and other minor constituents used
with overcured epoxy resin quartz crystal attachments gave the best
transmission characteristics  a shorter account of the work is given
in tech news bull nat bur march vol no
   /
6058
the calculation of transients in dynamical systems
   /
6059
a stable high speed multichannel pulse analyzer  pulse selection
in each channel is accomplished by a single discriminator whose threshold
is set at a height corresponding to the upper boundary of the
channel the channel width being determined by suitably shaping the
incoming pulses
   /
6060
frequency discrimination and stabilization of square wave modulated
microwave transmissions
   /
6061
pulling effect in synchronized systems  synchronization of a valve
oscillator with a low pass filter in the feedback loop is considered
and the phase equation method of analysis applied with parameters
m and t proportional to the detuning and to the filter time constant
respectively  for the operating point lies within the synchronization
range but the system remains in the asynchronous state ie pulling
effect exists for values of greater than a critical value  for the
system is synchronized and if this is an initial condition of the
system synchronization will be maintained for values of up to unity
a graph of the pulling function ie the relation between m and t obtained
in part by analysis in part from experiment is shown  the case of
a limiter in the feedback loop is also considered
   /
6062
the design of a radio frequency coaxial resistor  characteristics
of the cylindrical coaxial resistor intended for use as a reflection
free termination are discussed and design curves given  the jacket
diameter is chosen to maintain the resistive component of the resistor
at the required value  the reactive component may be compensated
in two ways  the first suitable for resistor lengths consists in
undercutting the line  the second requires the insertion of a short
circuited transmission line in series with the resistor and will
give either perfect compensation over a restricted frequency range
or less accurate compensation over a wide range  the effect of the
holder is taken into account
   /
6063
iron free cylindrical coils with reduced external field  the design
of coils with zero magnetic moment is described and the necessary
formulae are given  the arrangement consists of three coaxial coils
connected so that the outer coil produces a field opposing that of
the two inner coils and of such magnitude as to reduce the external
field to nearly zero  the internal field is approximately equal to
that of the innermost coil alone  coils of this type are useful eg
for focusing electron beams for magnetic measurements and for inductance
standards  see also
   /
6064
design of high frequency coils for high currents  a practical guide
to the design of single layer air cored cylindrical coils and a short
circuit variometer  the dissipation of heat electrical breakdown
potential and the various losses are considered  formulae tables
and an inductance coil dimensions nomogram are given
   /
6065
the performance of dried and sealed mica capacitors  good stability
has been achieved in an capacitor by drying it for a year and then
mounting it in a sealed container  the interdependence of the variations
of capacitance and power factor over the frequency range is discussed
   /
6066
tantalum electrolytic capacitors  a general review of types of electrolytic
capacitors and problems of design manufacture and testing of
ta types  data are presented for three csf capacitors having volumes
of and cm with average capacitances of and respectively at operation
   /
6067
normalization of the frequency dependence of impedance and amplifier
circuits outline of generalized circuit theory
   /
6068
some observations on time considered as a complex variable  results
of applying this concept in fourier and laplace transformations are
examined and its application to the analysis of transients is discussed
a practical interpretation of reversing the real time complex frequency
relation is given with reference to echo phenomena
   /
6069
the transistor as a network element  the use of transistors for reduction
of dissipation elimination of inductance production of delay inversion
of impedance is discussed  improvements in performance can be
achieved which would otherwise be unobtainable or uneconomic
   /
6070
the brownian movement of linear and nonlinear systems  the application
of brownian movement analysis to systems with a nonlinear relaxation
mechanism eg electrical conductivity is considered  a statistical
hypothesis is proposed which enables a calculation to be made of
the brownian movement and corresponding frequency spectrum of such
systems  the results are relevant to the study of electrical noise
   /
6071
note on the theory of brownian motion in nonlinear systems  the hypothesis
advanced by macdonald is shown to be not self consistent
   /
6072
a new method of synthesis of reactance networks  since the chain
matrix of a cascade combination of quadripoles is the product of
the individual chain matrices and since synthesis of a complicated
network by the insertion loss method involves obtaining a number
of simple sections to be connected in cascade the chain matrix is
chosen for this purpose  a method of factorizing any relizable chain
matrix into two such matrices of lower order is presented  repeated
factorizationsections simple enough to be synthesized  the method
involves only simple algebra and a new theorem concerning reactance
and impedance functions
   /
6073
lumpsed parameter delay lines  the application of rigorous filter
theory to delay lines comprising a series of coaxial coils is difficult
owing to the coupling between nonadjacent coils  an experimental
method of obtaining frequency characteristics is outlined  the latter
can be corrected by connecting a capacitor across adjacent coils
filter theory is applied to give an indication of suitable capacitance
values
   /
6074
monotonic transient response  restrictions are derived which must
be placed on the poles and zeros of the system function of a linear
system with lumped constants in order that the response of the system
to a step function drive shall be monotonic  system functions having
up to three s zeros are considered  a method of dealing with systems
containing more than three zeros is explained
   /
6075
distortion of arbitrarily shaped curves by rc sections  a method
is given of calculating the distortion by a rc network of any signal
which is expressible as the sum of a power series and terms containing
exponential functions of the circuit time constants  tables and nomograms
are given for calculating the output form given the input curve
and vice versa for rectangular trapezoidal triangular parabolic and
exponential type pulses
   /
6076
matching circuits for asymmetrical wire aerials  a comparison of
various types of aerial coupling circuits used particularly at medium
and long wave lengths and of the case of adjustment for use at different
frequencies  the discussion shows that the most advantageous circuits
consist of two variable reactances used in conjunction with an impedance
meter  examples of this type for use at or at medium waves are shown
   /
6077
action of periodic telegraphy signals on cascaded rlc resonant circuits
the response to rectangular trapezoidal and sine squared pulses of
a cascaded arrangement of up to three similar tuned circuits is investigated
theoretically and the results compared with the response of
a single tuned circuit of  the effect of a bandwidth and signal repetition
frequency is studied from the point of view of using the circuit
for fourier analysis and for reception of telegraphy
   /
6078
explicit formulae for the calculation of filter circuits with generalized
parameters  an extension of previous work of to the anti metrical
low pass the symmetrical and the antimetrical band pass characteristic
functions and the determination of the transmission factor
   /
6079
the smoothing of loss attenuation in basic types of ladder filter
the characteristics of basic and terminating half sections with losses
are derived from image parameter theory and the results applied to
show how the attenuation can be smoothed by introducing mismatch
at the end of the end of the filter or by inserting series and or
shunt resistors at properly chosen points within the network
   /
6080
the transient response of rf and if filters to a wave packet  discussion
on of
   /
6081
a stable voltage controlled logarithmic attenuator  the variable
impedance element is a triode operated so that the cathode impedance
varies approximately inversely as the transconductance  stabilization
is achieved by the use of dc feedback with a suitable increase in
loop gain  design procedure is given for both high and low input
types  experimental results are discussed
   /
6082
design of rc wide band degree phase difference network  the arrangement
comprises two all pass networks as described by orchard  the pole
zero pairs are first determined so as to give the difference of phase
shift over the frequency band and the networks are synthesized from
the response functions thus found  design procedure is detailed step
by step and is illustrated by a numerical example  notes on construction
and alignment are included
   /
6083
a nonreciprocal microwave component  in the presence of a steady
magnetic field the permeability of a ferrite is an asymmetrical tensor
this property is applied in the construction of a nonreciprocal device
comprising a waveguide in which a ferrite block is arranged asymmetrically
and parallel to the axis a static magnetic field being applied
transversely  experimental results are given
   /
6084
valve oscillators with voltage controlled frequency dependence  a
discussion of various circuits in which reactance is varied by application
of control voltage and a comprison of their performance in respect
of band width and output at medium and high frequencies
   /
6085
ultra low frequency three phase oscillator  an oscillator for the
frequency range uses three identical networks each comprising a polystyrene
capacitor and a stable resistor in a stair arrangement radiating
from the power supply  the circuit is in effect a three stage amplifier
oscillations occurring at the frequency for which the phase shift
is in each rc network  uses is made of the miller effect to keep
down the size and cost of the frequency determining elements
   /
6086
electronically tuned wide range oscillator  a hel transmission line
with ge diodes mounted at intervals of is used as tuning element
in a colpitts circuit  tuning is accomplished by applying a switching
pulse to a selected diode to short the line  the five tuning positions
give frequencies of about and respectively  the length of helical
line required is very much less than that of a parallel conductor
line for the same frequency  satisfactory operation of an experimental
model was achieved at switching rates up to pulses sec
   /
6087
perturbations of a nonlinear filtered oscillator  analysis summarized
earlier and of the effect of a disturbance on the behaviour of an
oscillator comprising a nonlinear amplifier feedback loop and low
pass filter  see also of
   /
6088
audio oscillator uses new design  a general generator covering the
range in four bands has both low pass and high pass rc filters incorporated
in the feedback loop to give good frequency stability and good
waveform  amplified agc is included in a commercial adaptation of
the circuit
   /
6089
positive gap germanium diode
   /
6090
noise discriminator for periodic signals  the periodic signal of
any waveform is applied through a phase inverter to one pair of terminals
of a resistance bridge including two diode rectifiers  periodic
pulses are applied to the other pair of bridge terminals  during
each pulse the diodes are unblocked and the signal passes to an integrating
circuit with an adjustable time constant  if the pulse frequency
is slightly greater than the signal frequency the output obtained
has the waveform of the noise free input signal and a much lower
frequency random noise mains interference and any other disturbance
of a frequency which is not a multiple of the signal frequency will
not be reproduced  the unit was designed for use with nuclear magnetic
resonance apparatus
   /
6091
subharmonic crystal oscillators  the operating frequency of a relaxation
oscillator can be stabilized at a submultiple of a crystal frequency
in a conventional blocking oscillator with a crystal connected across
the third winding of the pulse transformer frequency division by
factors up to several thousand can be effected  a multivibrator with
crystal between anode and grid of one valve gave good frequency and
pulse width stability when operating with a division factor of  details
of these two circuits are given three others have been examined namely
a screen coupled phantastron a thyratron and a transistor circuit
   /
6092
use of variable gain amplifiers in acoustic measurements
   /
6093
harmonic distortion and negative feedback  different methods of defining
gain in relation to the output voltage input voltage characteristic
of an amplifier are discussed for a nonlinear amplifier it is reasonable
to base the definition on the average slope  a method is indicated
for constructing the characteristic of the amplifier with feedback
from that of the amplifier without  distortion can be reduced by
means of feedback even for flat regions of the characteristic this
result is in disagreement with that of rowlands of  detailed analysis
is given for several types of amplifier
   /
6094
application of the multivibrator principle in counter tube amplifiers
a description is given of a pulse amplifier based on a multivibrator
circuit which gives an output pulse of amplitude with a leading edge
slope of for a input pulse
   /
6095
ae cathode resistor in the quiescent case
   /
6096
cathode coupled valves  a graphical method is described for investigating
cathode coupled amplifiers  the method is demonstrated in relation
to a circuit using a type twin triode and involves the construction
of composite load lines on the anode characteristics  an initial
trial solution must be found to determine the voltage across tan
ac cathode follower circuit of very high input impedance  a push
pull amplifier for the range is described  each half of the input
consists of a cathode follower with gain approximately unity with
a constant current cathode load constituted by a further valve  the
effect of grid anode capacitance in the input valve is reduced by
driving the anode by another cathode follower in series with it
input capacitance is and input resistance up to  circuit modifications
to obtain zero or negative input capacitance are explained
   /
6097
flux preset high speed magnetic amplifiers
   /
6098
parallel connected magnetic amplifiers  a complete analysis based
on a single valued bh relation is made for three types of load resistive
inductive and capacitive  transient response is considered  analysis
of feedback amplifiers shows clearly the jump phenomenon in the output
characteristic
   /
6099
high frequency transistor amplifiers  transistor high frequency transistor
amplifiers  transistor equivalent circuits appropriate for hf
wide band operation are presented  input and output impedance and
power gain for grounded base and grounded emitter arrangements are
discussed  the design of an if amplifier using four npn transistors
is described as an example the bandwidth is centred at and the gain
is pr stage
   /
6100
transistor equations using h parameters  transistor circuit calculations
are simplified by making use of d fundamental parameters for the
four terminal network corresponding to the base input common emitter
circuit  circuit equations in terms of these parameters are tabulated
for the three basic configurations
   /
6101
design of transistor power amplifiers  methods are outlined for obtaining
maximum power output consistent with acceptable distortion  factors
considered include stage gain and power supply  using values obtanable
with the transistor two numerical examples are worked out a class
a push pull grounded base arrangement for a low distortion af amplifier
and a clas b grounded emitter arrangement for a output stage
   /
6102
temperature compensated dc transitor amplifier temperature compensated
dc transistor amplifier  the variation of transistor parameters with
temperature is discussed  compensation can be provided by using temperature
sensitive resistors  a description is given of an experimental
dc amplifier compensated in this way
   /
6103
pulse formation and supply for magnetrons  discussion of the design
of a modulator capable of handling pulses of the order of at wit
a duration of an a repetition rate of per sec  the method of pulse
formation used is based on the slow charging of a capacitor the use
of artifical lines for pulse shaping is described  if a pulse transformer
is used the charging voltage need not be unduly high
   /
6104
trends of development in the field of electrical component for telecommunication
component design is considered from the point of view of
the physics and chemistry involved in meeting the requirements of
operation over a particular frequency band operation under conditions
of prescribed current waveform and intensity operation under peak
loads operation at low loss operation under given ambient conditions
operation under restrictions of tolerance stability and durability
   /
6105
components exhibition  trends in developments portrayed at the recmf
show  a review of the exhibition held in london april
   /
6106
printed circuit design sources  a detailed sources available in the
usa
   /
6107
standardization of printed circuit materials  results of tests on
metal clad plastic laminates for thermal endurance under simulated
manufacturing conditions adhesion variation between the centre and
the edge of the sheet bond strength during solder dipping ad hand
soldering effects of dust are shown graphically  these and other
types of bond strength tests are discussed from the point of view
of establishing quality standards and standard conditions of test
the positioning of components to avoid bond stress and the proer
choice of operating temperatures are also considered
   /
6108
a theory of the electron  an essentially classical theory is proposed
by analogy with the gravitational theory of matter it is based on
equations of the form suggested by mie in  the mass of the form suggested
by mie in  the mass of the electron is accounted for by means
of the energy of the field
   /
6109
diffusion of pulsed currents in conductors  theoretical investigation
of the density distribution and the equivalent depth of penetration
of a transient current for the case of a plane tem wave incident
normally upon a plane conductor  particular pulse waveforms are considered
see also f
   /
6110
the decay of the space charges in intermittent discharges in neon
and argon  the influence of the gas pressure and electrode separation
on the decay of the space charges is investigated experimentally
the decay times for both neon and argon appear to be of the order
of sec and are nearly proportional to the pressure over the range
of measurement about  possible explanations of these values are discussed
and the various regions of the static characteristic are related
to the functioning of counters and periodic discharges
   /
6111
the high pressure glow discharge in air  report of observations on
the glow discharge in air at a pressure of about mm hg  between cu
and w electrodes characteristics are given for discharge lengths
of mm and currents of a
   /
6112
spectrum intensities and radio frequency noise in a dc hydrogen arc
rf noise generated by the arc was reduced by shunting the arc with
a capacitor this caused an incidental modification of the ultraviolet
spectrum  the results suggest a connection between the noise intensity
and the distribution of energy among the electrons
   /
6113
investigation of the electron emission from nickel  experiments show
that the work function of a single crystal of n reduced in hydrogen
is higher above the curie point than below it  this result is shown
graphically  field strengths of about were used in measurements of
electron emission from a point source  photographs of the emission
patterns are shown
   /
6114
a note on the formula for the mobility of electrons with mean free
path varying with velocity  a correct generalized formula is derived
for the electronic drift velocity in an ionized gas taking the townsend
ramsauer effect into account
   /
6115
theory of the work function of metals  the polarizing action of individual
electrons on the distribution of the remaining electrons in the
conduction band is investigated by means of extended thomas fermi
statistics and the effect on the magnitude of the work function
is calculated  in alkali metals the work function is determined largely
by this polarization effect image force and only l slightly by the
electrostatic double layer at the metal boundary
   /
6116
fluctuation magnetic after effect  thesis based on neels theory on
the irreversible after effect in ferromagnetic materials which is
identified with the residual loss  earlier reports of the work were
noted in of and of in which it should have been stated that the square
root of the remanent magnetization is proportional to the logarithm
of time elapsed from the suppression of the field and to the logarithm
of the duration of application
   /
6117
self consistent electrodynamics  the idea of direct action between
streams is applied to a continuous charged fluid and com ined with
the new formulation of the electrodynamical laws of motion in terms
of conservation of circulation  a simple and rigorous integrated
formulation is thus obtained from the maxwell lorentz differential
equations applicable to co existing positive and negative fluids
as well as vacuum  exact solutions are obtained among them one which
represents self consistent self maintained flow in a hollow tubular
region of infinite axial extent  it is hoped this tube might be bent
into a torus and that an electron model will result from merely quantizing
the one or two vortices around which this flow pattern circulates
   /
6118
on the current induced in a conducting ribbon by a current filament
parallel to it
   /
6119
on a complete theory of diffraction of electric waves by a perfect
conducting wedge  continuation of work abstracted in of  the analysis
is revised and completed and errata are corrected
   /
6120
diffraction of electromagnetic waves by an aperture in a large screen
bekefis approximate formula is derived simply by another method
   /
6121
one to two millimeter wave spectroscopy part experimental methods
and results for ocs chf and ho  continuation of work reported previously
of  multiplier and detector performance were greatly improved by
using crystals small compared to the wavelength to be detected  a
new tuning technique based on known absorption lines was developed
measurements made included that of a new water vapour line at
   /
6122
a dc comparison radiometer
   /
6123
revised data for the mean sunspot curve  when the data for the present
nearly concluded year cycle are included with those for the seventeen
preceding cycles the mean curve exhibits a slightly steeper rise
and a slightly shallower fall thus increasing its asymmetry
   /
6124
controls of geomagnetic activity by sunspots  showed that a decrease
of magnetic activity occurs when two sunspots or groups of sunspots
are symmetrically located on the solar disk with respect to the solar
equator  on the basis of this work and that of denisse of it should
be possible to forecast each year on an average about perturbed and
quiet days
   /
6125
identification of the most powerful discrete sources of radio emission
of the galaxy with the residual of supernovae exploded in the last
years
   /
6126
experimental determination of the total intensity of the terrestrial
magnetic field in the lower region of the upper atmosphere e layer
fuller account of work described previously of march
   /
6127
plasma theory of the ionosphere  the basic equations for the dynamic
and electrical behaviour of the ionosphere are derived from the theory
of a theory of a neutral plasma and are used to investigate the problems
of diffusion of the plasma at layer boundaries em damping of air
movements and tidal oscillations of the ionosphere
   /
6128
electron density in the upper atmosphere and interpretation of the
curves of ionosphere virtual height part  a calculation is made of
the optical path of a wave reflected by a chapman layer with a semithickness
where h is the scale height  comparison of the results with
those obtained previously indicates that the lower half of such a
layer is closely approximated by a parabolic layer of semithickness
the electron density distribution is investigated for regions of
superposition of the f and true f layers taking recombination into
account  the linear superposition formula used previously is found
to be inadequate and is replaced by the formula where n and n are
the independent densities of the f and true f layers
   /
6129
a tentative model of the equilibrium height distribution of nitric
oxide in the high atmosphere and the resulting d layer  two possible
processes for the production of no are considered three body recombination
with o and photodissociation of into n and no  the distribution
of known constituents of the atmosphere in the range is discussed
and the no height distribution derived for the two possible production
processes  d layer ionization characteristics are satisfactorily
explained assuming photoionization of no at and the electron distribution
is derived both for the case of photo chemical equilibrium of
no and for a nonequilibrium distribution under the conditions of
complete mixing
   /
6130
the determination of the electron density distribution of an ionosphere
layer in the presence of an external magnetic field  the electron
density distribution is determined by finding the actual heights
at which waves of various frequencies are reflected  these true heights
are obtained from experimental curves by obtaining the exact solution
as a convergent series of integrals of the integral equation giving
the group height as a function of frequency  the errors arising in
the numerical work are shown by applying the procedure to hf curves
obtained theoretically from layers of known shape and such errors
are seen to be small compared with those made through use of other
procedures
   /
6131
regularities in the f region of the ionosphere  justification of
the assumptions made in of february is presented
   /
6132
correlation between variations of surface pressure and ionospheric
parameters  a statistical analysis was made of meteorological and
ionospheric data obtained at calcutta during the period of  correlation
between variations of ionosphere parameters and of surface pressure
was found at least for some months of the year  the results are in
agreement with those obtained in australia by martyn ad pulley  previously
proposed tentative explanations based on variations of ozone
content or the effects of circulation in the troposphere are examined
further data are required in order to assess their correctness
   /
6133
recent advances in the study of ionospheric winds  the radio fading
method developed by mitra of and the meteor trail echo method developed
by manning et al of for investigating ionospheric winds are briefly
reviewed and results so far obtained are discussed
   /
6134
the effect of sunrise on the reflection height of low frequency waves
the observed sudden changes of phase and amplitude of waves transmitted
over distances of are discussed in relation to the geometry of the
system at the change over from night time to daytime reflection height
and respectively  the effect cannot be due to photoionization of
atmospheric molecules but may be due to the removal of electrons
from negative oxygen ions by visible and near infrared radiation
calculations are presented giving support to this view  the rate
of fall of the reflection height is discussed
   /
6135
measurement of the electrical conductivity in the upper air by radioseconde
description of a measurement technique using the gerdien conductivity
apparatus in conjunction with a valve electrometer and an af
modulated m american type radiosonde
   /
6136
generation of electricity in thunderstorms  a general account of
the origin and nature of lightning
   /
6137
the higher order modes in the propagation of long electric waves
in the earth air ionosphere system and two applications horizontal
and vertical dipole
   /
6138
the pulse transfer function and its application to sampling servo
systems  discussion on
   /
6139
measuring the effectiveness of shielding materials  a method developed
at the us naval research laboratory is described  only a small sample
of the material under test eg wire mesh or conducting coating is
needed  the sample is inserted between two shield cans containing
transmitting and receiving aerials respectively and the attenuation
increase produced by the sample is observed  the frequency range
investigated is it may be s possible to extend the method to higher
frequencies by using waveguide technique
   /
6140
thyratron inverter  description of a unit giving at from dc mains
   /
6141
rectifier with smoothing capacitor and high vacuum valves or selenium
rectifiers  exact equations are derived for a p phase rectifier circuit
with a capacitance connected across the load  for practical use approximate
formulae are derived  and their application is illustrated by
the design of a two phase rectifier for an output of
   /
6142
silicon pn junction power rectifiers and lightning protectors  a
method of preparing large area junction diodes is indicated in which
donor eg or acceptor eg b impurities are diffused into high purity
single crystals of si at temperatures above  low resistivity surface
layers are produced facilitating the application of contacts  electrical
characteristics are presented of a power rectifier and a lightning
protector prepared by this method
   /
6143
a simple mains unit for highly constant alternating voltages and
currents  a unit giving a voltage continuously variable up to and
currents up to is described the voltage varying not more than with
mains voltage variations up to and mains frequency variations up
to
   /
6144
a new dc electronic voltage stabilizing circuit  the detecting element
across the supply consists of a negative resistance and a positive
resistance nce element of equal numerical values in series  by controlling
the negative resistance complete compensation can be achieved
a circuit built on a similar principle but using a different type
of negative resistance element was described by patchett of  a stabilizer
with an output of is described in detail the output can be maintained
constant to within for an input fluctuation of and a load variation
of  the circuit is suitable for voltages from upwards
   /
6145
relay standardization  summarized report of proceedings of symposium
on em relays held at oklahoma in june  military applications were
the main consideration
   /
6146
recent patents on electrical accumulators  review of developments
for previous review see of
   /
6147
arrangement of batteries and relays permitting the solution by analogy
of nonlinear partial differential equations by means of a chain of
resistances and capacitances
   /
6148
scale factors for analog computers  description of a design technique
whereby scale factors relating analogue variables to the variables
of the system investigated are first determined for true time operation
   /
6149
a time sharing analog multiplier  the circuit is based on the same
principle as that of broomall and riebman of  accuracy to within
is achieved for a range of input voltages from to when the comparator
voltage lies between and depending on the circuit arrangements  multiplications
per second were made indicating the suitability of the circuit
for time sharing techniques but higher rates of operation seem possible
   /
6150
system organization of the dyseac  dyseac is a general purpose high
speed digital computer incorporating the following special facilities
external transfer operations concurrent with internal computing such
transfers referring directly to any area of the internal storage
system adjustment of speed of internal programme so that it proceeds
in step with the external programme interruption of a programme for
interpolation of new orders
   /
6151
a simple analogue divider  a circuit is described which provides
an output voltage proportional to the ratio between two input voltages
a pulse of duration inversely proportional to one input being used
to gate the other input  the results are accurate to within over
a wide range of inputs  an operational digital feedback divider
in this divider the input pulses operate directly on the output the
circuit forming a closed feedback loop in which the desired quotient
corresponds to the only possible steady state  the accuracy of the
system can be selected by using the approprate number of significant
digits from the eleven available  new high frequency proximity effect
formula
   /
6152
an rms sensitive phase shifting circuit  a circuit delivering an
output whose phase depends on the rms value of the input uses a tungsten
filament diode as rms current detector  the diode is operated with
voltage on the anode n and a voltage derived from the ac component
of anode current is added to a fixed voltage to give the resultant
variable phase output  applications for control purposes are mentioned
   /
6153
a double base diode a semiconductor thyratron analog
   /
6154
a nomograph to facilitate the design of single layer resistance windings
   /
6155
how to use thermistors  review of thermistor characteristics and
applications with tabulated data for rod disk washer and bead types
   /
6156
current noise in composition resistors  because of the inherent inhomogeneity
of the resistor material and because the noise depends on
the square of the current density modification of the resistor structure
at a few points of high current density can have a large effect on
the noise without greatly affecting the dc resistance  experimental
evidence in support of this view is given  the effect may account
for the observed lack of correlation between noise and dc resistance
with large currents  measurements made on resistors of the same rating
but different types indicate a relation between noise coefficient
and shape factor
   /
6157
a new high speed bistable device for pulse sharpening  description
of a triode hexode flip flop circuit of generating pulses sec and
its application in switching and scaling circuits
   /
6158
rlc canonic forms  a class of rlc networks is defined which has canonic
structure in the foster sense  lc and rl rc network and networks
with slight dissipation may belong to this class in which case their
analysis or synthesis is simplified  examples of network synthesis
illustrate the method
   /
6159
bounds existing on the time and frequency responses of various types
of networks  six theorems are presented relating the transient and
steady state responses of linear stable fixed lumped constant networks
fourier transform analysis is used  physical interpretations are
discussed rise times and settling times being considered  the overshoot
or undershoot of the response to a step current input for a rc driving
point impedance cannot be
   /
6160
corner plots  an approximation to the shape of the actual response
curve for rl and rc circuits  is obtained by suitable combinations
of straight lines called corner plots  the parameters involved are
defined and rules for their determination by inspection of the circuit
derived  the method is not restricted to impedances but may also
be applied to network transfer functions and is discussed in bodes
network analysis and feedback amplifier design chapter
   /
6161
matrix analysis of multiterminal transducers  the multiterminal transducer
is defined as a network with a set of n input terminals and a
set of n output terminals  it can be represented by its impedance
admittance or transfer matrix  special properties of networks exhibiting
symmetry and or reciprocity are discussed  the representation is
classed as definite or indefinite according as the voltage reference
terminals are or are not specified  simple networks can be analysed
by inspection more complicated networks may be treated as cascades
of simple ones  the method is illustrated by deriving the transfer
matrices of some simple networks including a distributed amplifier
section
   /
6162
natural vibrations of a open cavity  the field is expressed in a
manner taking account of a set of oscillation modes associated with
the cavity openings
   /
6163
cavity resonator design charts  charts applicable to square section
and to circular section cavities are given
   /
6164
a generalization of weissflochs transformation law  the transformation
law relating to a loss free quadripole between homogeneous lines
is generalized by showing that all points on the transformation curve
can be correlated with corresponding positions on the input and output
lines between which the quadripole acts as an ideal transformer with
a reactance in parallel  see also of
   /
6165
transient response in fm  the fm response to the unit impulse and
the unit step function is calculated for a network whose transfer
function is known  a meaning is assigned to the associated fourier
integrals which diverge in the riemann sense  the methos is generalized
to any input function which vanishes for negative  as an illustration
of the method the impulse and the step fm responses of a single tuned
circuit are calculated
   /
6166
filter using coaxial transmission line as elements  exact equivalent
circuits are presented for coaxial line elements with sleeve or undercut
sections taking account of capacitance or inductance effects at the
discontinuities  from the corresponding equations the performance
of filters comprising one or more of such elements can be pred in
terms of image impedance cut off frequency attenuation and band limits
measurements on a tvariable usw filters  results of an investigation
of filters with distributed circuit elements and their equivalents
with lumped lcr indicate the circuits suitable for usw use  the filters
described which consist of adjustabl cavity resonators and short
lines include separating filters for metre ba d television and an
adjacent channel suppressor for transmitters and transmitter receivers
   /
6167
notes on a cause of frequency instability of partially plated piezoelectric
crystals proximity effect  external field conditions may have
a marked effect on the resonance frequency of partially plated crystals
movement of an object close to the resonator may produce a relative
frequency shift of the order of or even  as an extreme example a
shift of about was produced by hand effect in a at cut crystal of
diameter mm and electrode diameter the equivalent resistance simultaneously
increasing by  a quantitative explanation of the effect is given
by reference to equivalent circuits
   /
6168
the fluctuating character of the establishment of oscillations in
an oscillator  the build up of oscillations in a lcr oscillator by
white noise potential fluctuations is considered theoretically
   /
6169
a wide band oscillator using a conical helix tuning inductor  description
of an oscillator working over a frequency range of and using a
single tank circuit between the grid and the anode of a triode  the
tuning circuit consists of a variable inductor formed by two conical
helices connected at their apices by a large capacitor and two variable
cylindrical capacitors  for the high frequency end the leads connecting
the coils to the grid and the anode are used as transmission lines
the main tuning circuit being automatically isolated  methods of
calculating the oscillation frequency in terms of the circuit parameters
are described simplifying assumptions being mace  a description is
given of the design and performance of an experimental model for
the range mcs
   /
6170
internal oscillations and microwaves in transistors
   /
6171
transistor convert sine waves to pulses  a circuit using eight point
contact transistors  to amplify limit and differentiate a sine wave
input is described  the power supply unit uses junction diodes  the
frequency range is minimum input is pulse output maximum pulse rise
time pulse width adjustable from to and output impedance of
   /
6172
a mains supplied indicating dc amplifier with linear response  a
stage unit for use in conjunction with a piezoelectric transducer
and a duddell oscillograph for obtaining indicator diagrams is described
an electrometer valve is used as input to a first preamplifier
stage from which cable connection is made to the remaining amplifier
stages and the oscillograph  amplifier stability is good and effects
of valve aging not apparent
   /
6173
some circuit considerations of the transistor  a detailed discussion
of the single stage transistor amplifier and in particular of the
unity coupler condition  stability criteria are also discussed  since
four useful varieties of a single stage amplifier exist a two stage
amplifier can take different forms  these are divided into four groups
high power gain low terminating resistance high terminating resistance
and bilateral type  the latter is an emitter base base emitter circuit
and is suitable for obtaining high gains
   /
6174
a triode fm discriminator  the triode is arranged to operate as a
gated rectifier with the gating time and hence the rectified output
dependent on the input frequency  a sine wave with the straight portion
extending over about one radian can be used for the input waveform
for a particular circuit in which the rectified output should theoretically
change by about for a frequency change for this frequency difference
was about  the output is proportional to input amplitude as well
as to frequency
   /
6175
minimizing contact potential in apparatus design  consideration is
given particularly to the design of radio equipment required to function
under adverse conditions such as exposure to humid or salt laden
atmosphere  a table reproduced from the inter services document rcs
gives the potentials of various metals in sea water against the saturated
calomel electrode as a guide to the choice of metal coatings the
latter may be applied by electroplating spraying or hot dippling
   /
6176
single operated tone compensation  a triode valve is used as variable
element of a circuit which boosts amplifier response at both ends
of the af range to compensate for the reduced response of the ear
the amount of boost thus varies automatically with the input level
   /
6177
on diffraction by a strip  limitations of the integral equation and
fourier lame methods of dealing with the problem of diffraction by
a strip or slit are discussed  the variational technique of levine
and schwinger of can b used to obtain an approximate value of the
far zone field in a form which is stationary with respect to small
variations about is true value of the current induced in the strip
a calculation using this representation and assuming as a rough approximation
as a rough approximation a uniform density distribution of
current in the strip gives a good approximation to the value of the
far zone field  the scattering cross section is then found by using
the scattering theorem of papas
   /
6178
diffraction of electromagnetic waves radiated from an arbitrarily
oriented electric or magnetic dipole at an ideally conducting half
plane  the solving of this problem is simplified by writing maxwells
equations in a general form so as to include the case of a conducting
medium with a finite permeability and by including a magnetic current
for reasons of symmetry  the equation is solved for different boundary
conditions of p  in particular cases p represents components of the
electric or magnetic fields or vector potentials or vector potentials
t is a function of position which is zero except in a small volume
element surrounding the dipole and with the usual notation for the
dielectric constant angular frequency electrical conductivity permeability
velocity of light and to  the solutions for various orientations
of the dipole are given in the form of definite single integrals
which can be evaluated
   /
6179
energy loss of electrons in passage through thin films  energy loss
values of electrons passing through thin evaporated films of metals
and insulators are tabulated  reasonable agreement with calculations
of pines and bohm of april and pine of may is shown
   /
6180
the field e and the induction d of a point electric charge in space
   /
6181
solid state electronics  a general account of the mechanism of electronic
conduction in solids
   /
6182
notes on the comparison between the study of an imperfect contact
and experimental results on thin metal films  continuation of investigation
of the conduction mechanism in thin films of nifontoff and perrot
   /
6183
electron ejection by slow positive ions incident on flashed and gas
covered metallic surfaces
   /
6184
liberation of electrons by positive ion impact on the cathode of
a pulsed townsend discharge tube  of
   /
6185
ionization processes in the electrical breakdown of gases  a brief
review
   /
6186
diffusion cooling o electrons in ionized gases  measurements made
during low pressure ne and ar afterglows show a reduction in ambipolar
diffusion coefficient characteristic of diffusion cooling which is
not observed when he is present
   /
6187
the mechanism of secondary electron emission  a simple theory based
on the constant energy loss per unit path length of primary electrons
accounts quantitatively for the variation of secondary electron yield
below its maximum value  the theory can be extended to include a
bethe type energy loss at high primary energies  relations between
secondary electron emission and atomic structure are discussed  secondary
emission in insulators and semiconductors is also considered
   /
6188
explanation of the inaccuracy of secondary electron measurements
a recording arrangement used for the measurements is described  a
variation of the secondary electron ratio with beam density was observed
in several metals  this variation is probably due to the formation
of positive ions at the target  when this is taken into account the
secondary electron velocity distribution is found to b independent
of temperature in the range contrary to several other published results
   /
6189
threshold of secondary electron emission of nickel and molybdenum
the threshold is defined as the minimum energy of primary electrons
for which the number of slow secondary electrons differ from zero
experimental results show that it is equal to the work function within
the limits of experimental error  the velocity distribution of secondary
electron including reflected electrons at various primary electron
energies and the effect of pe treatment of mo by heating at for a
period up to days are discussed and the experimental results shown
graphically
   /
6190
effective depth of secondary electron emission  an experimental investigation
is reported  the principal conclusions are tht the effective
depth of secondary electron emission is smaller in metals than in
semiconductors that it is independent of the primary electron energy
and that there is no direct relation between the secondary emission
efficiency and the emission depth
   /
6191
theory of plasmas in the presence of a constant magnetic field of
arbitrary intensity superimposed on an oscillating electric field
generalization of results obtained previously of july and back reference
   /
6192
pressure effects of ionic currents in atmospheric air with various
discharge configurations  the mechanical pressures produced by steady
and modulated ion currents were investigated theoretically for parallel
plate concentric sphere and concentric cylinder electrode systems
and experimentally for a point and plate system  the agreement between
theoretical and experimental results is good  the investigation is
of interest in relation to the ionic loudspeaker
   /
6193
a refinement of the pauling theory of ferromagnetism  the theory
formulated by pauling of is modified to take into account the nonuniform
electron density in ferromagnetic crystals
   /
6194
electrodynamics without potentials  by means of a more general approach
based on the em field and not potential field equations of a general
type are derived  these contain the equations of diracs new theory
of electrodynamics of as an important special case
   /
6195
maxwells tensor  without modifying the classical em field equations
it is possible to replace maxwells tensor by another which gives
the same expression for the lorentz force but a different and in
some ways more satisfactory expression for the distribution of energy
in the field
   /
6196
self excitation of oscillations in a gas discharge at high pressures
the interaction of sound and electron waves in a gas discharge plasma
at pressures hg is considered theoretically  the possibility is shown
of self excitation of a definite range of frequencies  see also of
for work at mm hg
   /
6197
group velocity  continuation of previous work of  theory applicable
to the ionosphere and to waveguides is given
   /
6198
the excitation of plasma oscillations  a beam of high energy electrons
injected into the plasma of a dc discharge from an auxiliary electron
gun excited oscillations in the plasma the standing wave patterns
set up for varying values of electron beam density and thickness
of the ion space charge sheath being investigated by a movable probe
discontinuous changes in oscillation frequency occurred as either
the electron density or the sheath thickness was varied but the frequencies
were in accordance with the tonks langmuir relation and wehners
transit time relation of in both cases  the results confirm that
the mechanism of energy transfer involved is a vm process as suggested
by wehner and indicate that the oscillation is a longitudinal pressure
wave set up in the plasma electrons
   /
6199
zeeman effect and line breadth studies of the microwave lines of
oxygen  experiments with applied fields gauss gave results in accordance
with weak field zeeman theory  the two important mechanisms involved
are rotational resonance interaction and quadrupole quadrupole interaction
   /
6200
absorption of uhg radio waves in the range by substituted benzenes
part  measurements have been made on chlorobenzene bromobenzene o
xylene and m xylene at room and lower temperatures the positions
of absorption peaks are reported
   /
6201
relations between magneto optical phenomena in the visible and radio
regions of the spectrum
   /
6202
the distribution of temperature along a thin rod electrically heated
in vacuo part theoretical  an integral expression derived for the
temperature distribution can be expanded as a convergent power series
for evaluation two regions are defined region a in the middle of
the rod and region b the portions outside a  in the a region temperature
distribution is parabolic in the b region it is practically the same
as in the corresponding end region of an infinitely long rod  an
analytical expression is obtained for the temperat ure at the centre
of a rod as a function of its length  for a summary of the analysis
see
   /
6203
antenna and receiver measurements by solar and cosmic noise  the
sun and various intense cosmic sources of rf radiation which have
been previously measured are used as calibration sources for determining
aerial patterns and receiver sensitivities for radio astronomy investigations
practical procedure is outlined  inaccuracies are involved
in evaluating background radiation contours and solar energy distribution
but the technique is sufficiently accurate for checking field
instruments
   /
6204
radio evidence of the ejection of very fast particles from the sun
dynamic spectra of type rf bursts fast frequency drift duration sec
are discussed  the observations were made using a spectroscope with
a frequency range  harmonic pairs are commonly observed as in the
case of the longer duration type bursts previously studied of february
wild et al from a comparison of the profiles for the fundamental
and the second harmonic it appear that a low frequency cut off process
occurs in this case also  the observed properties of type bursts
can be accounted for by associating the frequency drift with motion
of a disturbance such as a corpuscular stream travelling outwards
through the solar atmosphere  several possible mechanisms are considered
   /
6205
washington conference on radio astronomy  the aim of the conference
was to present a comprehensive survey of the present state of work
in the field to examine some of the most critical problems and to
indicate possible future lines of research  summaries of some of
the papers are given  for a short report see science
   /
6206
generation of radio noise by cosmic sources  critical comment on
of january and authors reply
   /
6207
on the nature of the discrete radio sources  investigation of results
of measurements of radio noise from a source in cassiopeia shows
that the noise may be due to interaction of cosmic ray electrons
with the local magnetic field if the average value of the latter
is of the oder of gauss  the rf power received shoul then vary at
leastas rapidly as below a critical frequency in the range
   /
6208
effective radio ground conductivity measurements in the united states
the results of ground conductivity determinations made at broadcasting
stations at frequencies between and are presented in a series of
maps more than radials being shown  the degree of correlation between
the effective conductivity and the nture of the surface soil is insufficient
for purposes of prediction
   /
6209
electron inertia and terrestrial magnetism  analysis shows that electron
inertia effects make no appreciable contribution to the geomagnetic
field
   /
6210
the areal distribution of geomagnetic activity as an aeromagnetic
survey problem near the auroral zone
   /
6211
on the dynamo theory of geomagnetic field variations  chapmans expression
for the current function is solved in the most general way assuming
that the main component in atmospheric oscillation is semidiurnal
and using th same conductivity function as chapman  tables of coefficients
of the current function and numerical equinoctial values of th
coefficients deduced by the authors and by chapman are given  the
sq variations of h and v are deduced and compared with the results
of observations at abinger and alibag and with chapmans analysis
in these calculations the phase of the atmospheric oscillations has
been taken as and results compare well with observations
   /
6212
the lunar diurnal variations of the earths magnetic field for all
elements at amberley nz based on five years observations
   /
6213
very long sequences of geomagnetic activity and its annual variation
a study was made of the recurrence tendency of geomagnetic activity
for the period to  two long sequences of storms were identified mainly
associated with solar m regions  the mean recurrence period for each
of the sequences was days  characteristic annual variation is attributed
to the approach of the earths projection on the solar disk towards
the zones of maximum solar activity
   /
6214
magnetic storms aurorae ionosphere and zodiacal light  general account
of observed phenomena and review of theories which have been advanced
in attempts to explain them
   /
6215
study of atmospheric ions in a nonequilibrium system  the variation
with time of the concentration of small ions in the atmosphere in
a nonequilibrium system has been determined theoretically and in
two sets of experiments  if the atmosphere is relatively unpolluted
equilibrium conditions may not be restored after disturbance until
a time of about minutes has elapsed
   /
6216
the dissociation of oxygen in the high atmosphere  the transition
region is investigated using recent data on atmospheric transmission
of solar radiation in the spectral region of the schumann runge continuum
of o  observational data can be represented by a complete mixing
of the atmosphere which causes the vertical distribution of molecular
oxygen to follow atmospheric scale height  mixing and diffusing processes
are responsible for a shift in the transition region to lower
heights than given by photochemical equilibrium considerations thus
the transition region must be associated with the mesopause  airglow
formation of ionosphere regions and dissociation of nitrogen are
briefly discussed in the light of this theory
   /
6217
motion of the storm d regions  results of an analysis at the national
bureau of standards of ionosphere data from stations for the four
years do not support piggotts hypothesis of coherent motion of storm
d regions of
   /
6218
propagation of a plane aerodynamic wave of semidiurnal oscillation
period through a plane ionosphere in a uniform magnetic field  analysis
is based on the momentum equation for the gas and the tensor equation
of electric conduction derived earlier of july  frequency and wave
length correspond to the atmospheric oscillations caused by tidal
effects of the sun and the moon  the solution indicates that em damping
of the atmospheric oscillations will occur at height  the electrical
conductivity in a horizontal and in a vertical magnetic field is
expressed as a function of the neutral gas density
   /
6219
dynamo theory of geomagnetic tides  plasma theory and results of
earlier analysis of july are applied in deriving a differential equation
expressing height integrated ionospheric current as a function of
latitude  taking account of coriolis forces and assuming a velocity
amplitude of for tidal oscillations at e layer height the calculated
magnitude of geomagnetic tides is in agreement with recorded data
in particular as regards the large tidal amplitudes at the magnetic
equator  the theory is consistent with the assumption that the negative
particles in the e layer are predominantly electrons rather than
ions
   /
6220
ionospheric wind analysis by meteoric echo techniques  the procedure
for finding vector average wind of is shown to be unaffected by the
presence of turbulent wind components  expressions are derived for
the rms values of the horizontal and vertical wind components  sources
of errors are discussed in detail
   /
6221
winds in the upper atmosphere deduced from the dynamo theory of geomagnetic
disturbance  simple dynamo theory of winds moving along and
perpendicular to the geomagnetic field is developed and various wind
systems are discussed which might account for certain phases of magnetic
storms  a possible wind system for the main phase of a magnetic storm
shows some measure of agreement with diurnal atmospheric motions
deduced from radio star scintillations and auroral motions  the role
of such wind systems in modifying the effective transverse conductivity
of the ionosphere is uncertain  both the flux of x rays producing
ionization and the dynamo airflow in the e region are apparently
the same on days of magnetic storms as on days prior to them
   /
6222
correlation of magnetic auroral and ionospheric variations at saskatoon
part  the relations between magnetic auroral and ionospheric observations
are summarized with reference to the occurrence of positive and
negative magnetic bays  auroral light associated with positive bays
occurs at a higher geomagnetic latitude than that associated with
negative bays  the magnetic and auroral light variations are compared
to martyns theory of the aurora  if the latter is accepted the conclusion
is reached that most aurora is caused by positively charged particles
and that the conditions described for the early phase actually exist
throughout most of a disturbance  part of june
   /
6223
some results of sweep frequency investigation in the low frequency
band  frequency sweep measurements in the range are reported  day
time records show traces of three strata whose virtual heights are
between and of which the lowest not always observed produces only
a week echo and one sometimes suggesting that scattering is taking
place at randomly located clouds  night time records show an intermediate
layer between the e and f layers which is erratic in appearance
but seems to have continuity with the daytime e layer during sunset
traces characteristic of magneto ionic splitting are exhibited for
this intermediate layer  polarization and virtual height records
for the f layer at night are shown z and the effects of moderate
ionosphere disturbances are demonstrated
   /
6224
influence of the ionosphere on the reception of galactic radiation
of frequency  analysis of continuous measurements recorded at marcoussis
from to april indicates that galactic radiation at is attenuated
by the ionosphere the effect being due partly to the f layer and
partly to the d layer  the results agree qualitatively with those
obtained by mitra and shain of may using a frequency of
   /
6225
errors inherent in the radar measurement of rainfall at attenuating
wavelengths
   /
6226
radar evidence of a generating level for snow
   /
6227
atmospheric electricity and long distance very high frequency scatter
transmissions
   /
6228
the electrical conductivity of the atmosphere over the pacific ocean
conductivity measurements were made at altitudes of and and between
geomagnetic latitudes of and  the rate of production of ion pairs
computed from the measurements agrees well with that computed from
cosmic ray data
   /
6229
propagation of a pulse in a waveguide
   /
6230
shielding nomograph
   /
6231
thermoelectric generator  description of a paraffin lamp driven generator
for use with battery type receivers  the outputs are for the vibrator
ht unit and for heaters  tapping is also provided as being more
efficient than pure metal thermd  semiconductor type thermoelements
are mentiono couples
   /
6232
solutions of boundary value problems on automatic computing equipment
report of an investigation in which five types of digital computer
and one differential analyser were compared as regards their suitability
for solving boundary value problems
   /
6233
a progressive code digital quantizer  description of an analogue
to digital converter which receives information from a graph reader
and gives a corresponding numerical indication  several circuits
are shown based on the principle of comparing the analogue voltage
with the sum of a finite geometric series
   /
6234
the manchester university high speed digital computer
   /
6235
a mercury delay line memory unit  the storage unit in the csiro digital
computer is described a method is discussed of interspacing the pulses
of one loop between those of another loop thus doubling the storage
capacity
   /
6236
a review of magnetic and ferroelectric computing components  high
speed digital storage devices may be classified as delay line or
random access types with subdivisions in each case for regenerative
and nonregenerative devices  the more important magnetic and ferroelectric
storage units are critically discussed and possible future lines
of development indicated  references
   /
6237
an arithmetic unit for automatic digital computers  discussion of
the requirements for th arithmetic unit of a computer with magnetic
drum store with particular reference to the computer for the swiss
federal institute of technology  operation with fixed or floating
decimal point is provided for
   /
6238
magnetic switching circuits  magnetic circuits to produce the logical
operations of and and or are described which may be combined to produce
any switching function of any number of input binary variables  the
only components used are magnetic cores wire and resistors  there
is no extremely sensitive parameter in these circuits which must
be adjusted carefully in order to ensure proper operation
   /
6239
a simplified solution and new application of an analyser of algebraic
polynomials  a description is given of an analyser circuit in which
complex numbers are represented by sinusoidal voltages of frequency
with amplitude corresponding to the modulus and phase corresponding
to the argument of the number
   /
6240
prevention of ionization in small power transformers  the ionization
onset voltage is raised for a given total thickness of insulation
by inserting foils in the insulation so as to split it into n sections
with of the total voltage across each section  design details and
test results for a typical transformer are given
   /
6241
some characteristics and limitations of capacitor and resistor components
six types of film dielectric capacitors are examined with respect
to their performance  specifications for a new and reliable type
of metallized paper capacitor at the pilot plant development stage
are given  a satisfactory method for power rating of precision bobbin
resistors is explained
   /
6242
stressed ferrites having rectangular hysteresis loops  to obtain
the rectangular hysteresis loop required in ferrite cores used in
switching and storage devices the cores are stressed by encasing
them in plastics which shrink during polymerization
   /
6243
temperature fields in electrical coils  numerical solutions  the
computation of the steady temperature fields in coils by the relaxation
method is described and illustrated
   /
6244
saturable reactors with inductive dc load part transient response
part
   /
6245
a graphical method for flip flop design
   /
6246
switching in bistable circuits  all triggering processes seem capable
of description in terms of a curve with a region of negative slope
points on this curve representing unstable states while points on
a s positive slope represent stable states  a negative resistance
circuit in which the voltage is a multiple valued function of current
was constructed so that details of the triggering process could be
observed on an oscilloscope screen  by suitable periodic sampling
a slow motion representation of the transition between two states
is obtained
   /
6247
an electronic random selector  criteria for recognition of random
series are stated and methods for producing such series are discussed
a description is given of an arrangement in which pulses are applied
to a circuit which is gated periodically any pulse passing tr through
the gate triggers a multivibrator which is in turn coupled to a pair
of mechanical registers  two such circuits make up the complete selector
enabling four mechanical registers to operate  use of the selector
in psychical research is mentioned
   /
6248
the transient response of transistor switching circuits  transient
response of the point contact transistor in a grounded base circuit
is considered using a linearized equivalent circuit  the required
trigger voltages for both directions of switching are found experimentally
to be greater than suggested y the static characteristic and
to depend on trigger pulse width to a different extent for the two
directions  to fit these findings it is assumed that cut off frequency
is high when the transistor is switched off and low when it is switched
on  the one shot multivibrator is discussed in the light of these
assumptions
   /
6249
a cold cathode scaling unit  the five decade scaler uses dekatrons
interstage coupling being by cold cathode gas filled trigger triodes
the resolving time is which makes it suitable for application in
conjunction with counter tubes  operation under varying climatic
conditions has been satisfactory
   /
6250
the effect of minor constituents in high dielectric constant titanate
capacitors  additives used to modify te dielectric properties of
are classified into two groups those which alter the position of
the curie peak and those which lower its height  and are typical
of the first group while and are typica of the second the effect
of composition on nonlinearity and aging is discussed  see also and
of january
   /
6251
breakdown and leakage resistance investigation of metallized paper
capacitors  the basis of comparison between conventional paper and
metallized paper capacitors is discussed  experiments on units with
polyester impregnants suggest that if self healing is of primary
importance a pure aliphatic hydrocarbon type of impregnant will give
best results
   /
6252
applications of integral equations to the solution of nonlinear electric
circuit problems  the technique described gives practical results
in many cases where the approximate solution of the integral equation
may be effected by means of laplace transforms
   /
6253
junction transistor circuits  application of the pnp junction type
transistor in single stage and cascaded amplifiers and in lf and
rf oscillators is described and illustrated by eight circuit diagrams
the transistor collector characteristics and operating data and typical
circuit component values are given
   /
6254
spectrum or waveform equalization  the method of equalization in
which signals obtained by differentiation or integration are added
to the main signal of is compared with the commoner method using
filters  empirical design is simpler with the former method but the
need for additional amplification at high frequencies n is not avoided
the different requirements of communication and servo systems are
indicated
   /
6255
new effect caused by gyromagnetic phenomena  theory is given of a
device similar to that described by kales et al
   /
6256
effects of harmonics on the frequency of oscillation as well as on
the asymmetry of the resonance curves  the nonlinear equations representing
the free and synchronized oscillations are transformed into
linear equations with periodically varying coefficients and complete
solutions are obtained  the relation between frequency variation
and harmonic content is derived  experimental results supporting
the theory are reported
   /
6257
the first order behavior of separable oscillators  analysis is given
for oscillators whose linear and nonlinear elements are separable
in the first order  theoretical and experimental results indicate
that apart from adjustments of the linear elements the major factor
for obtaining frequency stability and smooth control is the suppression
of the even power terms in the amplitude characteristic
   /
6258
quantum theory of a damped electrical oscillator and noise part the
radiation resistance  the results obtained in part of are extended
to include damping and noise due to a radiation resistance and expressions
for the mean square noise voltage and available noise power are
derived which are shown to be the sm same as those previously obtained
they are also extended to apply to a single mode of a cavity resonator
   /
6259
vacuum fluctuation noise  the possibility of observing vacuum fluctuations
by measuring the resultant electron stream noise when an electron
stream interacts with a damped oscillator is discussed  an electron
stream i shown to provide a means of precise measurement of the mean
square noise emf for certain modes  the circuit must be at low temperature
   /
6260
block diagram solutions for vacuum tube circuits
   /
6261
millimeter waves from harmonic generators  fundamental and harmonic
powers obtainable at wave lengths down to using a si crystal frequency
multiplier with different types of reflex klystron have been measured
three types of multiplier are compared these are a commercial si
crystal mounted upright on the exterior face of the harmonic waveguide
a crystal with windows cut in the face so tht the tungsten whisker
is exposed a whisker and si block mounted in the waveguide  arrangement
is the most satisfactory for wavelengths below mm  the performance
of arrangement as a detector is discussed  a crystal harmonic generator
used with a n narrow band amplifier will furnish enough power at
mm wavelength to give a dynamic range of
   /
6262
variable frequency crystal controlled receivers and generators
   /
6263
a modified miller timebase circuit  high linearity and rapid flyback
are achieved by using a blocking oscillator to charge the feedback
capacitor in the miller type circuit  compensation is provided for
variations in the blocking oscillator characteristics  a unit giving
sweep durations of with either triggered or continuous operation
is described
   /
6264
transient response of glow discharges with applications
   /
6265
lf compensation for video amplifiers part  amplifiers without feedback
the departure from the ideal flat top response caused by low frequency
distortion can be reduced by making the differential coefficients
of the output function equal to zero at  the order of compensation
is designated by the number of derivatives equal to zero  general
theory is given and is applied to some typical resistance coupled
amplifiers  a single rc coupled stg stage can have second order compensation
and multistage amplifiers can have higher orders of compensation
experimental results confirm the analysis
   /
6266
an electronic voltage integrator  a feedback amplifier integrating
circuit is described  the amplifier comprises a cascode connected
direct coupled circuit with filament drift compensation and internal
positive feedback adjustment  the integrator is used with a search
coil for magnetic field measurements in the range gauss accuracy
is within
   /
6267
a high efficiency high quality audio frequency power amplifier  the
circuit uses a type valve as phase inverter amplifier driver stage
direct coupled to two output beam tetrodes operating in class b push
pull with db of feedback  the output transformer has a bifilar wound
primary and the feedback winding is electrostatically shielded from
the secondary but very closely coupled to it  full power output is
at frequencies  design of the circuits and performance details are
described
   /
6268
the cascode as a low noise audio amplifier
   /
6269
the influence of magnetic amplifier circuitry upon the operating
hysteresis loops  an analysis limited to the steady state characteristics
of single phase self saturated magnetic amplifiers  only resistive
loads are considered
   /
6270
high speed magnetic amplifiers  units based on ramseys half wave
amplifier are discussed and the development of a new series of amplifiers
is described  the basic type is a reversing phase input reversing
dc output amplifier  circuit modifications are explained for obtaining
reversing dc output fr reversing dc input and reversing phase ac
or reversing polarity dc output  other possible modifications are
indicated
   /
6271
theory of magnetic amplifiers with square loop core materials
   /
6272
temperature stabilized transistor amplifiers  design equations are
derived and nomograms presented for determining the temperature variation
of the operating point of a junction transistor amplifier  application
of the information for temperature stabilization is indicated
numerical examples are given
   /
6273
transistors in amplifier output stages  the optimum effective load
impedance and the efficiency are calculated using idealized characteristic
curves  the results for point contact and junction type transistors
in class a and in class b pushpull amplifiers are compared with the
corresponding formulae for triodes and pentodes  distortion the efficiency
limit and circuit design are also briefly considered
   /
6274
proposal for a new aether drift experiment  comment on furths proposal
of june and suggestion for an alternative experimental procedure
   /
6275
precision determination of the velocity of light derived from a band
spectrum method part  from measurements of the rotational constant
for by the method f exact orders and by a microwave method the value
of is
   /
6276
further experiments on the thermodielectric effect costs ribeiro
effect  the experiments described establish that on solidification
of liquid naphthalene negative charges are expelled from the solid
into the liquid phase the resultant positive charge being distributed
within the solidified e dielectric  see also of
   /
6277
further quantitative experiments on the costs ribeiro effect  in
an investigation of the thermodielectric effect above and back reference
measurements were made of the charge within a solidified naphthalene
dielectric by means of a faraday cage and electrometer  the relation
between the charge and the mass is constant  for small crystals this
specific residual charge is twice the induced charge per unit mass
impurities after the value of considerably
   /
6278
contact charging between a borosilicate glass and nickel  contact
charging of glass spheres rolling on clean ni was studied under conditions
of controlled cleanliness humidity and gas pressure  the effect
of a transverse electric field is important only for high surface
conductivity  surface conductivity  surface conduction limits the
maximum charge which also varies with pressure due to gaseous discharge
between the sphere and the metal
   /
6279
a chemical approach to the treatment of electronic spin in semiconductors
a method due to fowler in which the electrons and the neutral
and ionized donors are treated as chemical entities affords a simple
approach in the nondegenerate case  the results obtained agree with
those of landsberg of when the occurrence of neutral donors containing
a unpaired and paired electrons is taken into account
   /
6280
theory of the anomalous skin effect in a magnetic field  extension
of work by euter and sondheimer to take account of the effect of
a steady magnetic field
   /
6281
the effect of relaxation on microwave measurements of the anomalous
skin effect  the ratio of the conductivity to the mean free path
of an electron in bi t microwave frequencies estimated on on the
basis of dingles theory is compared with given earlier by pippard
and chambers neglecting relaxation effects  this discrepancy and
the discrepancy for normal metals are discussed
   /
6282
the anomalous skin effect and the reflectivity of metals  expressions
derived by reuter and sondheimer of are considerably simplified
numerical results obtained include calculated values of surface resistance
and reactance in the microwave region for both specular and diffuse
electron reflection
   /
6283
some aspects of breakdown streamers
   /
6284
the electric strength of air in nonuniform fields at radio frequencies
measurements were made of the breakdown potential of atmospheric
air between a cylinder and an axial wire over the frequency range
the breakdown voltage is about below the value at and decreases at
the average rate of per as the frequency is raised above this point
the results are explained by a modified townsend theory  the discharge
occurs during the part of the cycle when the wire is positive with
respect to the cylinder
   /
6285
the secondary electron resonance mechanism of low pressure high frequency
gas breakdown  breakdown field strengths were measured in air
and h at frequencies from to between internal electrodes separated
by cm  by suddenly applying a high voltage and reducing it slowly
an upper breakdown curve and cut off frequency dt together define
a breakdown region  the secondary electron resonance theories developed
by danielsson and gill and von engel are extended
   /
6286
dynamics of corona discharge between cylindrical electrodes  the
screening action of the space action of the space charge is responsible
for the constancy and stability of the average discharge current
fluctuations are explained as a response of the system having a definite
resonance frequency to the statistical fluctuations of the photoelectric
current  theoretical predictions are confirmed by experiment
   /
6287
the work function of irregular metal surfaces  calculation of the
image potential for spherical and spherical and prolate spheroidal
bosses on an otherwise smooth surface h shows that this potential
might be reduced to of its value for an ideal plane surface  since
the image potential is likely to form a large portion of the work
function for most metals the work function will be significantly
reduced when the surface is rough
   /
6288
effect of the energy distribution of electrons on the average secondary
emission yield of an insulator  an expression for the average yield
in terms of electron temperature is calculated for pyrex th electron
energy distribution being maxwellian
   /
6289
a model for collision processes in gases part small amplitude processes
in charged and neutral one component systems
   /
6290
electron ion recombination at low pressures  experiments throwing
light on the nature of the fundamental processes involved are discussed
the molecular ion is thought to play a decisive part  the evidence
is consistent with the hypothesis of dissociative recombination
   /
6291
the tensor formulation of ferromagnetic resonance
   /
6292
twisted magnetic fields in conducting fluids  the formation of loops
in the lines of force of a twisted magnetic field confined within
a cylinder of radius r is discussed by the method of normal modes
the condition obtained for loop formation is that the pitch of the
twisted field be less than r  the velocity of alfven waves in this
model is also discussed
   /
6293
diffusion after effect in weak alternating fields  validity of rayleighs
law
   /
6294
on the excitation of oscillations in a thermal plasma  plasma oscillations
are considered for an arbitrary distribution of electron beams
the fundamental equations are derived assuming a weak signal and
the absence of static fields  the dispersion relation derived is
applied to the case of excitation of thermal plasma by an injected
electron beam and the rate of wave growth is determined  the numerical
results are compared with results obtained by merrill and webb june
   /
6295
the vector wave function solution of the diffraction of electromagnetic
waves by circular disks and apertures  part the diffraction problems
   /
6296
determination of by a new method  the method involves the determination
of the excitation potential of he from the ground state to the lowest
permitted singlet level  the value of obtained is sec
   /
6297
temperature distribution in a electrically heated filament  a practical
general solution is given for a filament of finite length heated
in vacuo
   /
6298
physics and applications of secondary electron emission  the book
cover practically everything of importance and should serve as an
admirable guide to workers in all branches of electronics
   /
6299
relation between the appearance of the yellow coronal line and geomagnetic
activity  from observations of the yellow coronal line it is
possible t identify thoe solar activity centres whose passage across
the central meridian is accompanied by an increase of geomagnetic
activity
   /
6300
space charge wave amplification in a shock front and the fin structure
of solar radio noise  the dispersion equation corresponding to the
non maxwellian velocity distribution of the particles in a shock
front is derived  the roots indicate frequency bandwidths of space
charge wave amplification decreasing with the shock strength  it
is suggested in agreement with cenisse and rocard of that the storm
bursts of narrow bandwidth originating in shock fronts constitute
the elementary fine structure components of solar radio noise bursts
   /
6301
thermal radio emission from the sun and the source of coronal heating
a statistical analysis is made of data obtained from measurements
of solar radiation at frequencies between and  th total radiation
is separated into a component associated with sunspots and a basic
component showing no such connection  results indicate that sunspot
radiation and the very hot regions responsible for it diminish loss
rapidly than the spot area and exist for a month or more after the
spot has vanished the basic component at some frequencies is much
lower than previously believed s regions above the sunspots are the
source of coronal energy and gases spreading from them can completely
replace the corona in about four days
   /
6302
solar radio emissions at metres wavelength during inclusive and their
relations to solar activity  bursts at of duration min ad of intensity
over a certain minimum are analysed for correlation with solar flares
the medium lag of bursts behind associated flares is about a minute
but the dispersion of the time differences is such that an appreciable
proportion of the bursts precede the flares  secondary controlling
factors seem to exist both for the solar phenomena and the related
ionospheric phenomena  analysis of the distribution of bursts confirms
that there is a greater chance of bursts in association with flares
on the eastern half of the suns disk than on the western half
   /
6303
observation of the partial solar eclipse february at the wavelength
of centimeters  the diameter of the sun observed at this wavelength
is greater than that of the visual disk  limb brightening is observed
asymmetry in the eclipse curve is attributed to a local bright region
round sunspots where the values of electron density in chromosphere
and corona are enhanced
   /
6304
the distribution of radiation across the solar disk at metre wavelengths
measurements were made at wavelengths of and using variable aperture
interferometers an phase switching receiver systems  the size of
the emitting disk increases with increasing wavelength  experiments
with interferometers inclined at various angles to the solar axis
of rotation showed the radiating shape of thesun to be elliptical
the radial distance at which the brightness temperature was reduced
to half was about greater at the equator than in the polar direction
   /
6305
distribution of radio frequency brightness across the solar disk
and the derivation of a model corona  the derivation of a model consistent
with observations previously reported above is discussed
   /
6306
solar radio asymmetry at metres wavelength  the greater frequency
of observation of solar bursts at in association with flares on the
eastern half of the suns disk of may be due to absorption of bursts
from the western half in ionized streams  this would account for
the lack of evidence of asymmetry at for which wavelength absorption
is much less  an analysis of this asymmetry with reference to geomagnetic
activity is being made
   /
6307
intensities of discrete radio sources in cygnus and cassiopeia at
measured intensities are and for the sources in cassiopeia and cygnus
respectively  comparison with intensities measured previously at
higher frequencies indicates that in the spectrum of the cassiopeia
source intensity is proportional to frequency the variation in the
cygnus source being similar except at lower frequencies where the
rate of increase of intensity is reduced
   /
6308
radio emission from the perseus cluster  results of observations
at using radio interferometer apertures of and provide confirmation
for the identification of the radio source with ngc
   /
6309
galactic radiation at radio frequencies part discrete sources with
large angular widths  observation with a reflector at a frequency
of with the sea interferometer at and with the azimuth interferometer
at revealed the existence of a number of sources of angular width
the observations are described and discussed the limitations of interference
techniques are summarized  part
   /
6310
galactic radiation at radio frequencies part  discrete sources at
between declinations and  one hundred and four discrete sources have
been found  individual sources are compared in position and flux
density with those of previous surveys  the observed distribution
of sources is discussed  several identifications with visible sources
are suggested
   /
6311
a comparison of the intensities of cosmic noise observed at and at
the principal conclusion of this comparison is that the background
radiation cannot be made up of the radiation from sources of the type
observed so far although a small polar component may be due to the
extragalactic sources  absorption in interstellar gas has a considerable
effect on the intensity variations of background radiation with direction
observed at
   /
6312
observations of the general background and discrete sources of cosmic
noise  a survey of a broad strip of sky centred on declination has
been made using an aerial with beam width to half power of  previous
results concerning the background distribution of brightness have
been confirmed and discrete sources have been detected  the distribution
of these sources is shown  no correlation was found between the occurrence
of scintillations and published ionospheric data but the observations
are consistent with an origin of scintillations in irregularities
of dimensions about km at a height of about
   /
6313
galactic radio sources of large angular diameter  preliminary results
are given of measurements of the apparent angular width of sources
previously observed of may
   /
6314
wide band radio interferometer  the use of a wide band amplifier
with the frequency characteristic given in conjunction with an aerial
system consisting of two or four aerials in line or aerials arranged
symmetrically in a square results in very high resolution  in the
example quoted radio sources separated by an angle of ca be resolved
the theory of the interferometer is given and the general form of
the directional characteristic is shown
   /
6315
geomagnetic bay disturbances and their nonuniform induced components
within the earth  the bay disturbance is considered as the field
of a travelling dipole in the auroral zone the direction of travel
depending on time of day  the induced component within the earth
exhibits local variations depending on the conductivity a dynamic
anomaly is observed in an area in central europe the vertical component
being a maximum in the north and a minimum in the south when the
ionosphere current is directed southward
   /
6316
the use of earth potential measurements for magnetic and ionospheric
storm indication  using the underground telephone cable system potentials
are measured in directions as nearly parallel and perpendicular
to the magnetic meridian as possible  each of the cable circuits
is over long and is provided with several earthing points at the
ends  the recorders are housed in the control room of the ptt station
radio kootwijk
   /
6317
radio meteorology conference in texas
   /
6318
a preliminary survey of tropospheric refractive index measurements
for us interior and coastal regions  results of some recordings made
between july and december using airborne refractometers at heights
up to are summarized  the existence of large differences in refractive
index near certain cloud boundaries is confirmed  see also of june
crain et al
   /
6319
atmospheric space charge  comment on of january and authors reply
   /
6320
the evaluation of ionospheric observations  a critical discussion
of the various methods used in calculating the height distribution
of the charge carrier concentration and other parameters from experimentally
determined hf curves  the corrections and the estimation of
errors in the calculated f layer height in the presence of an e layer
and the effect of neglecting the e layer in this calculation are
discussed  an approximate method is indicated for taking the geomagnetic
field into account
   /
6321
semidiurnal currents and electron drifts in the ionosphere  correction
to paper abstracted in
   /
6322
a subsidiary layer in the e region of the ionosphere  echoes from
sporadic e can be distinguished from those from a layer at km height
it is suggested that the ionization in this layer results from the
impact of meteors on the atmosphere and that it may therefore be
called the meteoric e layer  the distinctive properties may be used
to extend the use of the ionosphere for intermediate distance radio
communication
   /
6323
origin of the ionospheric e layer  critical discussion of theories
of formation based on ionization of o by ultraviolet light and ionization
by solar soft x rays  the intensity of incoming radiation seems
insufficient in view of absorption in case but from elwerts computations
sufficient in case provided dissociation of oc occurs in a high transition
layer of considerable thickness both processes may be involved
but process seems the more important
   /
6324
multiple stratification of the f layer at ibadan  observations made
during the period december january are reported  in the f layer there
is a maximum occurrence of ridges around and hours the first maximum
being the more pronounced  a seasonal variation is found a maximum
number of ridges around and hours the first maximum being the more
pronounced  a seasonal variation is found a maximum number of ridges
being observed when the midday minimum of f occurs early in the day
a lunar semidiurnal variation is detectable during the morning hours
formation of ridges is also observed in the f layer but there is
little relation to those of the flayer  possible phases of vertical
drift velocities that could explain the observations are discussed
   /
6325
on the f layer distribution in polar region  results of an analysis
of monthly mean values of and for march are summarized  in a region
along the auroral zone where the values are anomalously high maxima
occur at noon and midnight and the region rotates round the earth
with the sun  the increase of apparent height of the f layer is due
to wave retardation in the f layer during daytime in high latitudes
   /
6326
a theory of distribution and variation of the ionospheric f layers
a brief description is first given on the results of our recent studies
which have led to the conclusions of inhibition of vertical ionospheric
current enhancement of conductivity dynamo current and vertical drift
of charged particles near the geomagnetic equator and suppression
of daytime electron density of f layer caused by an upward drift
of electrons  the treatment is extended to the case of ionospheric
storm accompanied with geomagnetic storm  the comparison of the theoretical
and observational results is made for the cases of undisturbed
as well as disturbed states of f layer  the agreement is generally
good for undisturbed case but not quite satisfactory for disturbed
case  the mechanism of dynamo in the ionosphere is discussed and
a hypothetical consideration concerning a wing system during a storm
is given
   /
6327
lunar radio echoes and the faraday effect in the ionosphere
   /
6328
the enhancement of ionospheric ionization during solar flares  study
of the recombination coefficient in the lower ionosphere based on
the decay of sudden phase anomalies at and on sudden enhancements
of atmospherics gives values much smaller than those reported by
bates and seaton  measurements of the delay between the time of maximum
flare and the times of maxima of sudden phase anomalies and sudden
enhancements of atmospherics also suggest smaller values these results
indicate that for any height the value of the recombination coefficient
remains unaltered during a sudden ionospheric disturbance and that
the sudden increase in electron concentration is due to an increase
in the rate of electron production in the layer
   /
6329
corpuscular eclipse in the f layer and its association with solar
flares and m regions  a survey of present knowledge on solar sources
of corpuscular streams and on corpuscular velocities  the drop in
the f layer ion density occurring approximately five hours before
the maximum of the optical solar eclipse is briefly discussed and
it is suggested that in future f layer observations should commence
at least seven hours before the moment of totality
   /
6330
high multiple radio reflections from the f layer of the ionosphere
at brisbane
   /
6331
the effect of rayleigh scattering and ground reflection upon the
determination of the height of the night airglow
   /
6332
servomechanism papers  six papers presented at a convention held
in san francisco august with editorial  trends in feedback systems
nonlinear control systems with random inputs  a method of analysis
and synthesis of closed loop servo systems containing small discontinuous
nonlinearities  stability of feedback systems using dual nyquist
diagram  optimum lead controller synthesis in feedback control systems
on the comparison of linear and nonlinear servo mechanism response
predictor servomechanisms
   /
6333
the use of steel sheet for the construction of shielded rooms
   /
6334
self heating triode for voltage stabilization
   /
6335
sun powers telephone  brief description of a battery comprising an
array of si strips each about which when exposed to sunlight gives
a current of at about
   /
6336
a versatile electronic function generator  two cypes of electronic
circuit for performing any desired transformation on two arbitrary
voltage waveforms are described  the general characteristics and
accuracy of such devices when used in repetitive differential analysers
are discussed
   /
6337
transistor shift registers  three different types of high speed transistor
shift registers are discussed  the high speed is made possible
by the use of nonsaturating bistable circuits  two general shift
registers r are described making use of respectively one n and two
transistors per stage  the third register is of a specialized variety
capable of shifting a single digit  in addition an analysis is made
of the triggering requirements of the register using a single transistor
per stage
   /
6338
waveguide switching device using gas filled tubes  an arrangement
for switching a single receiver between two or more channels at a
relatively high rate is described  the switching operation is based
on detuning an oscillatory circuit consisting of a waveguide section
terminated with inductive diaphragms and having a gas discharge tube
located midway between the ends the hf susceptance of the tube varies
with its ionization state and the tube constitutes an element of
a bandpass filter  analysis is given for the pass band the switching
rate the electrical inertia and the noise and insertion loss due
to the device  results obtained with a four channel system are in
good agreement with theory
   /
6339
component design trends fixed capacitors undergo miniaturization
first paper of a series describing recent developments  problems
involved in operating at the high temperatures resulting from reduction
of the heat dissipating surface are discussed
   /
6340
some techniques for network synthesis  the synthesis of immittances
with two poles and two zeros is discussed cauers continued fraction
technique is generalized for use in realizing rlc network immittances
design procedure is developed for a constant resistance ladder this
nt network is shown to have the same field of application as the
conventional rlc constant resistance bridge t but has the advantages
of greater flexibility and less complexity  complicated transfer
functions may be realized in a chain of ladder sections having arm
immittances with only two poles and two zeros
   /
6341
analysis of network response to periodic waves  the steady state
response of a network to a nonsinusoidal periodic wave may be found
by applying the operational calculus method of waidelich of in a
simplified form  the method can be used for any linear network comprising
a finite number of lumped elements  a set of rules for obtaining
the required inverse transforms together with a table of inverse
transforms for square wave inputs is pe presented and explained
   /
6342
feedback in junction transistor circuits  series and parallel feedback
circuits for a single stage are reduced to a four parameter equivalent
circuit for analysis  cascaded transistor stages reduced in a similar
manner result in either mesh or nodal derived equivalent circuits
   /
6343
q as a mathematical parameters  a definition applicable to rc networks
and other systems having lumped parameters an and appropriate in
cases where the q value is of the order of or less gives q in terms
of circuit time constant and the differential operator
   /
6344
ire standards on audio techniques definitions of terms
   /
6345
thermodynamical consideration of equilibrium electrical fluctuations
expressions are derived for the mean energy of electrical fluctuations
in an lcr circuit maintained at a given temperature and for the spectral
density of the fluctuation emf similar expressions published earlier
by gorelik and ginzburg are discussed
   /
6346
two network theorems concerning change of voltage reference terminal
the first theorem describes the change in the admittance matrix corresponding
to the change of the voltage reference terminal ground terminal
the second theorem shows that the determinant of the d admittance
matrix is invariant under such transformations
   /
6347
the application of some semiconductors as logarithmic elements  voltage
dividers incorporating rectifiers to give special characteristics
were described by kallmann of  for circuits involving high resistances
rectifiers made from other semiconductors may be more suitable  logarithmic
characteristics obtained using various semiconductor rectifiers
are presented  temperature compensation is achieved by use of negative
temperature coefficient resistors the logarithmic response has been
obtained at frequencies up to
   /
6348
practical low pass and band pass minimum phase networks with equalized
delay and a period transient response  a minimum phase shift network
with constant delay characteristic is a practical approximation to
an idealized low pass filter since its attenuation characteristic
in the pass band has a similar shape  conditions for delay equalization
are investigated for a unit step input in terms of the positions
of the zeros and poles of the response function  a general method
of calculation for filter networks of this type is given  the attenuation
and group delay characteristics in a simple case are compared
with those of an equivalent filter based on image parameter theory
   /
6349
audio frequency filter with continuously adjustable attenuation characteristic
a composite filter for the frequency band is described
comprising two sets each of separately controllable filters with
contiguous narrow frequency bands  the controls are arranged so that
the positions of the individual knobs give an approximate representation
of the overall frequency characteristic  the device is useful for
investigating correcting networks and for producing special effects
in broadcasting
   /
6350
synthesis of constant time delay networks  the synthesis of low pass
filters to have a symmetrical transient response such as is desirable
in television receivers is investigated  the desired frequency response
is expanded in a fourier series circuit elements corresponding to
the terms of the series are constituted by sections of delay lines
which are appropriately combined to give the desired overall response
low pass band pass and band stop filters are considered  results
obtained with experimental filters are discussed
   /
6351
punched card calculating machines as aids in the calculation of filters
the use of commercial type punched card calculators for solving numerical
problems involved in insertion loss filter theory is discussed
and illustrated
   /
6352
comb filters for pulsed radar use  the use of comb filters for improving
signal noise ratio is discussed in relation to the variation of the
frequency spectrum of a radar signal with the number of pulses in
the received trains  the relative merits of the simple uniform type
the rectangular sin type and the north type sin matched filters are
compared  the small gain in sensitivity obtained with type does not
warrant the greater complexity of its design
   /
6353
gain stable mixers and amplifiers with current feedback  narrow band
radio frequency amplifiers and mixers may be stabilized by negative
feedback without increasing the bandwidth excessively  a couple using
current feedback is described  this couple requires only a simple
resistive beta circuit and may be designed such that the band pass
characteristic is largely independent of the feedback  experimental
results are reported
   /
6354
van der pols equation  an analytic method f of solving the equation
is described in which the unknown functions and of the assumed solution
a sin are found by substituting the assumed solution into the integro
differential form of the origin the ionic oscillator  a stable device
capable of delivery high output at af or rf comprises a simple gas
filled valve circuit without external or internal resonators anode
voltage equal for the normal ionization voltage is applied  am and
fm arrangements are indicated  the upper frequency limit is
   /
6355
a reactance tube controlled oscillator of unusually wide frequency
sweep  circuits permitting frequency seeps up to are described one
for operation above and the other below
   /
6356
quartz generators with negative feedback and an inertial nonlinearity
theory is developed on lines similar to that presented by post and
pit of  results show that the best position for the amplitude limiting
element is in a separate negative feedback circuit of the amplifier
part of thetends to reduce the frequency and phase stability of the
oscillator  at frequencies of a few tens of kilocycles stable amplification
of the order of can be obtained using a three stage amplifier
with phase correction circuits  stable amplification at very high
and at very low frequencies is also mentioned
   /
6357
generalized equations for rc phase shift oscillators  general solutions
are obtained for three and four section phase shift networks  these
solutions are reduced to design equations for a number of specific
circuit configurations and the complete solution is given for a four
section phase shift oscillator
   /
6358
oscillator feedback networks of minimum attenuation  single valve
oscillators with feedback networks comprising three resistors and
three capacitors are discussed  optimum values for the components
are determined by analysis and are plotted as functions of valve
output resistance for a given value of valve input resistance  both
shunt r and shunt c networks are considered the former being recommended
for very low frequencies and the latter for relatively high ones
   /
6359
classification of quartz crystal oscillator circuits  classification
is based on quadripole representation ad two main classes are distinguished
according as the circuit is represented by one or two quadripoles
in the feedback line  the first class includes type networks subdivided
into series resonance and parallel resonance circuits and bridge type
circuits  variations of the a basic circuits are illustrated and
formulae are derived for the properties and operating conditions
the main characteristics considered are stabilization factors see
of excitation conditions operating frequency and crystal loading
   /
6360
an amplitude stabilized transistor oscillator  correction to paper
abstracted in
   /
6361
effect of steepness of rise and fall of the input pulse on the response
of pulse amplifiers part  expressions are derived for the response
of rc coupled amplifiers to input pulses of ramp form and of triangular
form
   /
6362
some experiments with miniature power triodes  description including
complete circuit diagrams and discussion of performance of two af
amplifiers with an output of about one of which uses valves in push
pull and the other four valves in parallel in a single ended output
using unselected components the latter amplifier gave a more satisfactory
performance
   /
6363
selective special amplifier for a frequency of  the design is discussed
of a four stage amplifier for use with a capacitor pick up  capacitance
due to variation of external gas pressure are in  the amplification
is sufficient to give an output galvanometer reading for an input
of across a resistance
   /
6364
distributed amplifier for nuclear research  details including component
values are given of a four stage amplifier with input and output
impedances of gain is over a bandwidth of  pulses with rise times
as short as sec are satisfactorily reproduced  linearity is good
up to output
   /
6365
lf compensation for video amplifiers part  negative feedback amplifiers
the method outlined in part of august is applied to negative feedback
amplifiers  if is independent of frequency the overall response is
optimum when the indicial response of the path is optimum and the
order of compensation is the same  if is made frequency dependent
by including a capacitor in the feedback path compensation can be
obtained which s one order higher than that obtainable from the path
alone  the method is applied to some simple circuits including cases
where a coupling or a decoupling circuit is outside the feedback
loop  experimental results confirming the theory are reported
   /
6366
study of noise reduction by feedback in ultra high frequency amplifiers
a detailed investigation has been made to determine theoretical and
practical limits for the cancellation of valve noise in rf amplifiers
measurements were made on a modified planar type of disk seal triode
designed to have a transit phase angle of about one radian at mcs
the conditions for complete noise cancellation are determined and
expressions are derived for input and output admittance available
power gain and noise figure can be reduced considerably by means
of feedback but w is thereby reduced at an equivalent or greater
rate so that the practical application of this method is uneconomical
with present valves  the uncorrelated part of the induced grid noise
is the most important factor in the increase in f at vhf
   /
6367
single core magnetic amplifier analysis
   /
6368
dissected amplifiers using negative resistance  possible circuit
arrangements of semiconductor devices to give hf amplification are
discussed based on segregation of the amplifier properties of negative
resistance and directionality  an arrangement of a hexagonal ge plate
with magnetic field perpendicular to its plane and with an appropriate
network of resistances corresponds to a pentode amplifier
   /
6369
transistor application fundamentals  a comparison is made of valve
and transistor characteristics in relation to a f amplifier circuits
the design of a gramophone pickup amplifier using the twin triode
and ge fused junction transistors is described circuit diagrams characteristic
curves and relevant formulae are given
   /
6370
resonant dielectric amplifier frequency response  discussion of an
amplifier of the type in which the capacitance of a nonlinear capacitor
excited to resonance by a carrier wave is modulated by a carrier
wave is modulated by a signal voltage and an amplified output is
obtained by subsequent demodulation  with a carrier circuit q value
of the carrier frequency must be of the order of the response to
be flat up to signal frequencies of
   /
6371
detection of a radio wave by a ferrite  a magneto strictive ferrite
rod of mm square cross section and length mm was exposed to a uhf
field pulsed at the third harmonic of the frequency of mechanical
resonance of the rod  the signal was detected by means of a tuned
coil located at a mechanical node  the detection process involves
rectification of the uhf oscillation as a result of the variation
of ferrite permeability with applied field and conversion of the
rectified signal into a magnetostrictive vibration  detectors of
this type may be useful at wavelengths of cm
   /
6372
characteristics of ultrasonic delay lines using quartz and barium
titanate ceramic transducers  equivalent circuit based analysis developed
previously of fagen is extended to deal with metal delay media
and with as well as quartz transducers  calculations are made of
the decrease in loss due to a decrease in the impedance of the delay
medium and of the increase in bandwidth due to an increase in its
impedance
   /
6373
simplifying fabrication of printed circuits  use of nitric acid in
a stencil etch process reduces production time greatly
   /
6374
comparison between luminescence and exo electron emission  the mechanism
and significance of exo electron emission of are investigated by studying
the emission of light quanta by luminescence under the same conditions
parallel effects in the two classes are tabulated and the close relation
between the two is established
   /
6375
diffraction by two parallel planes of finite length  the diffracting
system comprises a pair of parallel perfectly conducting planes of
infinite width and finite length  an incident em wave polarized perpendicular
to the edges of the planes is considered the theory thus applies
equally to the diffraction of a plane sound wave  two integral equations
are derived approximate solutions are obtained for the condition
an equation is derived giving the value of for resonance of the system
this is solved approximately and a formula is given for the end correction
ie the difference between the resonant length and
   /
6376
diffraction theory  a critical review of progress in classical diffraction
theory including references to over papers published since  both
scalar and electromagnetic problems are discussed the main emphasis
is on diffraction by plane obstacles especially by obstacles small
compared with
   /
6377
solution of boltzmanns equation for a lorentz gases
   /
6378
a note on the use of the titanates as thermoelectric transducers
approximate calculations for a solid solution of indicate that it
would not be useful as a thermoelectric transducer  it seems that
if materials could be produced with high permittivity and high temperature
coefficient of permittivity but independent of field strength
a transducer with an efficiency comparable to that of a steam engine
could be developed
   /
6379
greens functions in evaluating fields  analysis based on the derivation
of vector potentials from scalar potentials is extended to cases
in which the field varies with time  an outline is given of the method
used to calculate the field due to a current in a conductor  applications
include the calculation of fields in waveguides and resonant cavities
   /
6380
the magnetoresistance effect in metals at high frequencies  the calculation
of the effect is based on a model in which the electrons occupy
two overlapping partially filled bands of normal form  at low frequencies
the relative change in surface resistance is independent of frequency
and its variation with field strength is very similar to that observed
in dc  experiments  at high frequencies the effect ultimately drops
to zero the frequency region in which this occurs being determined
by the relaxation time  for normal metals it lies in the far infrared
experimental results for bi suggest that the relaxation time in bi
is abnormally large
   /
6381
current voltage characteristics of a self supporting gas discharge
in a transverse magnetic field continuation of previous work of march
measurements were made using coaxial cylinder electrodes with axial
magnetic field in argon at pressures from to below torr  falling
or rising characteristics are obtained according as the pressure
is greater or smaller tha some thousandths of a torr  at pressures
above this value the discharge has the nature of a glow discharge
with positive space charge  at pressures below this value this value
the characteristics are those of a self supporting high vacuum discharge
with negative space charge
   /
6382
study of the induced electrodeless discharge in neon  induction heating
theory is used to study the conductivity in the induced discharge
at a frequency of
   /
6383
on the radial extent of glow in microwave gas discharge between coaxial
cylinders  the glow appears in the region of maximum electric field
strength close to the central wire over a radius mm  the luminosity
depends on the net production rate of electrons pr unit volume  this
rate is calculated and is shown graphically as a function of radius
   /
6384
further research on the discharge between positiinuation of work
described previously of toitot and boulloud
   /
6385
investigation of the energy distribution of secondary electrons from
single crystals of copper covered with single crystal layers of copper
oxide  the secondary electron energy was measured by the retarding
field method  the energy distribution curve is steeper towards the
low energy side  in the case of polycrystalline cu covered with polycrystalline
cu one well defined maximum was observed in the single crystal
case subsidiary maxima were also found but the evidence for these
is not conclusive  the results are shown graphically
   /
6386
a reversible secondary emission fatigue effect observed in glow cathodes
comprising a semiconducting layer  if the usual metallic cathode
in a glow discharge tube is replaced by a composite cathode having
a semiconducting layer eg an cathode the self maintained discharge
current decreases with time when the current density does not exceed
a particular value dependent on cathode geometry an when the cell
is kept in the dark  recovery takes place slowly but is speeded up
if the cell is subjected to infrared radiation  th effect is ascribed
to reversible fatigue of the emission centres for secondary electrons
and the analogous effect observed with photocathodes suggests that
both photons and secondary electrons originate in the same emission
centres
   /
6387
antiferromagnetism  a survey paper giving particular attention to
van vlecks theory and including a discussion of the superexchange
mechanism  papers on experimental investigations are listed by compound
and by property studied  nearly references
   /
6388
fishers gyromagnetic effect observed in a body placed in a waveguide
the component of magnetization produced in a ferrite perpendicular
to the plane of a rotating magnetizing field may be detected in an
ellipsoidal specimen placed in a waveguide excited in the h mode
the theory and experiments which gave negative results were discussed
by fisher on  the effect can be used in determining magnetic fields
at very high frequencies
   /
6389
interpretation of the ampere experiments  ampere equation for the
force between current elements is unique assuming the correctness
of his five postulates  the general equations are here derived that
apply if either the third or the fifth postulate is omitted
   /
6390
the coulomb force and the ampere force  a study of the modification
of coulombs equation that will satisfy amperes experimental results
   /
6391
a new electrodynamics  a new formulation alternative to that of maxwells
equations is developed from the theories of weber and of ritz  the
fundamental equation expresses the force on a charged particle caused
by another charged particle  for preliminary work see and above
   /
6392
electromagnetic properties of plasmas in a magnetic field  continuation
of work reported in of assuming a constant and uniform magnetic field
results obtained are discussed in relation to those of other workers
in particular the matrix for the complex conductivity of an ionized
gas and and the dispersion equation  previous results apply only
for values of gyromagnetic frequency small compared with where is
the electron collision frequency and the pulsatance of the electric
field
   /
6393
magneto hydrodynamic waves in liquid sodium  torsional waves in liquid
na have been generated in a cylindrical vessel with the axis parallel
to a homogeneous magnetic field and resonance phenomena have been
investigated
   /
6394
propagation of electromagnetic waves in a gyrotropic medium  faradays
law of rotation of the plane of polarization is extended to take
account of the reflection and refraction at the boundaries of the
medium  the relation between path length and the angle of rotation
is derived and results for a lyer of are shown graphically for a
frequency of
   /
6395
investigation of the transverse thermomagnetic effect  the potential
difference produced between faces of a conductor perpendicular to
the applied magnetic field and perpendicular to the thermal flow
was measured and found to be proportional to the magnetization  in
weak fields hysteresis is observed at saturation the potential difference
remains constant  a formula similar to that representing the hall
effect is given  the results for low carbon steel are shown graphically
   /
6396
theory of origin of cosmic rays  it is shown that a random acceleration
process proposed by fermi and a physical location of the accelerating
filds in radio stars proposed by unsold account satisfactorily for
the main features of cosmic radiation
   /
6397
radar determination of the heights and radiants of meteor showers
the technique described by volmer of march was used for observations
of the germinids and aquarids  the results are discussed briefly
   /
6398
the physical condition of the solar corona  a review paper including
about references
   /
6399
probable observation of the galactic nucleus at mcs  brief report
of a survey of the central section of the milky way using an aerial
system with a beam width of  in the zone covered from to in declination
and from hr to hr in right ascension a strong concentration of brightness
was found near a line of galactic latitude with a maximum centred
at longitude
   /
6400
rocket instrumentation for reliable upper atmosphere temperature
determination  electronic telemetry equipment is described and typical
curves are presented showing the variation of pressure and temperature
with altitude
   /
6401
nbs research in radio propagation
   /
6402
electron resonance in ionospheric waves  a new aspect of the investigation
of travelling disturbances in the ionosphere is discussed which
leads to a more satisfactory interpretation of observational data
the hydrodynamic wave hypothesis of the earlier work of is retained
but the observed perturbations in the electron density are attributed
to a direct resonance in the electron oscillations regardless of
any em fields which may be generated in the process  formulae are
developed for two distinct classes of possible resonant oscillations
one involving and the other not involving a vertical component of
propagation  small scale disturbances above the f layer maximum which
have been held responsible for certain radio star scintillations
could be related to either set of formulae
   /
6403
some studies on the ionospheric storm  variations of are tabulated
and the field current system computed
   /
6404
simultaneous measurement of sweep frequency and of the ionosphere
outline description of frequency sweep equipment designed to cover
the range in four bands and used to obtain simultaneous records of
the variation of virtual height and critical frequency with time
sample records are shown
   /
6405
global characteristics of the separation between the f and f layers
of the ionosphere  records of the separation between the f and f
layers have been analysed in respect of seasonal and sunspot cycle
variations  the seasonal variations are similar to those observed
by appleton for the height of the f layer of at  at high latitude
stations the variation of separation followed the trend of sunspot
activity in summer but not in winter  at stations close to the geomagnetic
equator the separation varies inversely as sunspot activity in
all seasons  the observed variation with season and latitude are
consistent with the view that the f and f layers belong to a common
bank of ionization  no simple explanation of the variations with
sunspot cycle is at present possible
   /
6406
ionization distribution in the f region  the height distribution
of ionization in the composite f region is calculated on the assumptions
that the scale height ie the temperature increases and the recombination
coefficient decreases with height in this region  the recombination
coefficient is assumed to vary in terms of the reduced height that
is the height above f max measured in terms of the actual height
as had been done earlier by ap mitra in making similar calculations
the present assumption automatically takes into account the effect
of rising temperature on the value of the recombination coefficient
height distribution curves for high and low latitude stations are
drawn for typical summer and winter conditions in the high atmosphere
in the f region  when the possible effect of ionospheric tidal drifts
are taken into account the forms of the distribution curves and the
separation between the f and f layers agree with those deduced from
observations  the results support the view that the f and f layers
belong to a common bank of ionization produced by solar radiation
   /
6407
ionospheric observation during the partial solar eclipse february
the critical frequencies of all layers including the abnormal e layer
are discussed
   /
6408
polar magnetic storms and geomagnetic bays appendix a theory of field
an current system deduced from geomagnetic observations is compared
with a system calculated on the dynamo theory taking anisotropic
conductivity of the ionosphere into account  agreement is fairly
good  conductivity considerations suggest that the s current system
is located at a height below km
   /
6409
systematic investigations of the influence of geomagnetic disturbances
on the daytime f layer critical frequencies  a statistical analysis
has been made of f layer critical frequencies observed at linden
harz during the period december april and of geomagnetic observations
made at wingst during the same period  the geomagnetic data were
arranged according to he degree of disturbance and the mean deviations
of the critical frequencies corresponding to the different degrees
of geomagnetic disturbance were determined  dependence on sunspot
cycle and on season is exhibited  the significance of the results
for the prediction of short wave communication conditions is discussed
in detail  figures are given indicating the reliability of such predictions
   /
6410
on a change in geomagnetic declination accompanying intense sporadic
e layer ionization supplement  a statistical analysis revealed no
relation between intense sporadic e ionization and lunar diurnal
variation of geomagnetic declination in contradistinction to results
for the solar diurnal variation reported in of february
   /
6411
winds and turbulent air currents in the ionosphere  predominantly
horizontal linear air currents have been observed by direct and indirect
methods  the most frequent velocity is at altitudes between and and
in the f layer between and km  nonuniformity of direction is observed
the results indicate that wind direction and speed depend on time
of day and on season as well as on latitude  the observations confirmed
that turbulent currents are superposed on the linear currents in
the km region but yielded no corresponding information for the f
layer  the occurrence of solar and lunar tides in the e layer with
velocity amplitudes of and respectively was confirmed  observations
at the greatest possible number of stations are required to enable
further conclusions to be reached
   /
6412
horizontal movements in the ionosphere  a survey of investigation
methods and results under the following main headings reflected radio
waves observed at closely spaced points observations of movements
of large scale irregularities in the f region observations of waves
from radio stairs observations of waves reflected from meteor trails
observations of waves reflected from the sporadic e layer  the following
conclusions are reached at all levels in the ionosphere systematic
as well as irregular horizontal movements are present  typical velocities
are of the order of there is a tendency for the velocity to increase
with height  the systematic movements have the form of regular diurnal
and seasonal variations and show considerable consistency between
observations made in the northern and southern hemispheres  at heights
around km the semi diurnal components of the velocity as determined
by fourier analysis are found to represent a uniformly rotating velocity
vector the direction of the rotation is clockwise in the northern
hemisphere and anti clockwise in the southern hemisphere  this is
the type of movement predicted by the theory of atmospheric oscillations
though the phase of the rotation is not that expected theoretically
at times of magnetic disturbance the velocities of the horizontal
movements are increased and this phenomenon becomes more marked with
increasing height in the atmosphere  at velocities as high as have
been recorded during magnetic storms  a brief summary of observations
by non radio methods is included  about references
   /
6413
anomalous electric fields in the atmosphere  the potential gradient
in the atmosphere was found to depend to a large extent on the presence
of clouds  the formula derived which leads to results in good agreement
with measurements expresses the potential gradient at any given height
in terms of the known gradients at two other heights and the three
heights
   /
6414
atmospheric electricity  aspects of the subject discussed include
some in which significant advances have been made since publication
of the authors book of and some on which work was done in germany
during the war  about references
   /
6415
observation of atmospherics at very low frequencies  results of observations
at munich and several other places at frequencies in the range
are correlated with meteorological phenomena  two main types of waveform
were distinguished one comprising wave trains of duration at a frequency
about the other of a generally nonsinusoidal character at frequencies
between and  the former is associated with the presence of a temperature
inversion the latter with low nimbus clouds  the latter type occurred
most frequently one to two days prior to the onset of increased temperatures
neither type of atmospheric could be observed following the
onset of fohn type weather
   /
6416
analysis of nonlinear servos by phase plane delta method
   /
6417
series capacitors multiply battery voltage  the voltage obtainable
by charging capacitors in parallel and discharging them in series
is increased by using a set of capacitors of graded capacitance values
and charging the first by the battery only th second by the battery
in series with the first capacitor and so on  the method has been
used to provide using six capacitors with a battery
   /
6418
voltage and current stabilizers for laboratory use  a systematic
exposition of the principal types of stabilizer divided into three
main classes direct feedback and other types
   /
6419
ac voltage stabilizers  the operation of the output stage of the
valve operated ac mains stabilizer is analysed with th aid of load
lines and the relative advantages of various modes of operation are
briefly discussed
   /
6420
semiconductors as solid electrolytes in electrochemical systems
a single shot battery and a long life cell are described and the
physicochemical principles of operation outlined  the former an ag
agl ag s s cell gave an open circuit voltage of v at c  the short
circuit current was acm  the latter an ag agl c cell with an emf
of at room temperature can deliver a current of several hundred
   /
6421
applications of a high speed electronic computer to a business accounting
problem
   /
6422
digital servomechanism controls shaft position  devices for converting
data from digital to analogue form are discussed two experimental
system which convert binary digital input signals into shaft rotation
angles are described  the converter functions as a closed loop servomechanism
in which the error sensing portion is a digital computer
information can be indicated remotely with an accuracy within
   /
6423
a one dimensional fourier analog computer  the computer sums fourier
series having up to terms and can be used for double and triple summations
by using standard trigonometric expansions
   /
6424
solution of second order differential equations and partial differential
equations using a resistance network  description of an instrument
based on liebmanns design of which has an accuracy within about part
in
   /
6425
direct reading electronic correlator  paper strip recordings of two
functions r are read photo electrically and the electrical signals
thus obtained are converted into pulses which when coincident actuate
a computer  the correlation delay time can be varied up to any value
from a lower limit set by the recording speed
   /
6426
statistical computers as applied to industrial control  principles
and circuit techniques are discussed applications described include
the control of the diameter of extruded plastic cable sheating
   /
6427
the selenium rectifier in digital computer circuits  results are
reported of an investigation of the birkbeck college computer with
the object of replacing valves by more reliable elements where possible
measurements indicate that diameter se disk rectifiers are suitable
for use as shift diodes buffer isolators gating elements coincidence
sensing units and decoding matrix elements in computers where the
frequency of operation does not exceed
   /
6428
a new ac network analyser for the solution of problems arising in
the operation and extension of electrical power systems
   /
6429
an analogue computing circuit for the evaluation of the ratio of
two slowly varying potentials  the circuit based on the miller integrator
is described in detail the computed ratio is displayed as a meter
deflection  the use of feedback reduces the sensitivity to valve
characteristic variations the error is less than of full scale deflection
within wide input limits  computation of reciprocals and products
may be performed by means of similar circuits  several possible applications
of the device are mentioned
   /
6430
the ade photo electric integrator  the instrument which is in the
developmental stage is capable of evaluating surface integrals of
any function over a domain with boundaries not containing pooles
of the function  it comprises essentially a bottom lit light diffusing
table with a photoplate grating and photoelectric cell arranged above
the grating represents the function and an opaque mask represents
the domain of integration  integrals of a bivariate normal distribution
function over a domain with irregular boundaries have been obtained
   /
6431
charge carrier device as a high ohmic resistance  the principle of
the two arrangements described is the movement of a conductor a metal
ball of capacitance to and fro at a specified frequency in an es
field between two electrodes  the effective resistance r of the circuit
is c  in the first arrangement the ball is fitted to the periphery
of an insulated disk driven by a synchronous motor in the second
the ball is free and its movement is controlled by an electromagnet
details are given of the performance of the system operating in an
electrometer circuit with balls of different materials  with a ball
in diameter frequency cycles minute and electrode spacing mm
   /
6432
thermistor nomograph  chart for finding values of thermistor resistance
at given temperature  the accuracy is nearly as good as that of a
slide rule
   /
6433
demagnetization coefficients of high permeability cores  experimental
determination of the dependence of demagnetization coefficients on
geometrical dimensions of solid or laminated cores of rectangular
cross section and solid or hollow cylindrical cores  a semi empirical
formula for calculating the demagnetization coefficient of cylindrical
rectangular cross section and ellipsoidal cores is given and the
calculated results are shown to be in good agreement with measurements
   /
6434
an electronic ratchet  when groups of nine evenly spaced pulses are
applied to a decade scaler a series of output pulses is obtained
with separation increasing by one time unit for each pulse group
application of groups of eight pulses gives separation increasing
by two time units per groups of eleven pulses decrease the separation
by a single unit  the instrument described comprises two decade scalers
and can provide a maximum separation of time units for increasing
intervals or for decreasing intervals
   /
6435
component design trends new variable capacitors extend tuning range
over different types of variable capacitor in production were surveyed
an outline is given of techniques used for obtaining low minimum
capacitance and high maximum capacitance adapting for operation at
uhf miniaturizing and pressurizing
   /
6436
a simple thre terminal micrometer capacitor  description of a variable
capacitor in which a micrometer spindle moves along the axis of a
hollow cylinder which is coaxial with a cylindrical hole bored in
the brass block screen  typical range is from to for a movement of
the spindle
   /
6437
transistor characteristic parameters for weak alternating currents
a method of representation is proposed using an impedance matrix
which is completely symmetrical for all six transistor connections
formulae derived for input impedance current gain etc have the same
form for all the six circuits  the method requires a new definition
of the currents and voltages but affords the possibility of extension
to multielectrode systems  the setting up of matrices for complex
arrangements of resistors and transistors is illustrated
   /
6438
multilayer distributed constant delay lines
   /
6439
synthesis of passive networks with pairs of terminals specified by
their scattering matrices  the method described gives results different
from those of belevitch of and back references  equivalent networks
are represented by means of a uniquely defined regular network matrix
necessary and sufficient conditions for minimum phase shift are specified
in terms of matrix theory and the minimum number of elements excepting
ideal transformers required in equivalent networks is determined
relevant matrix theory is dealt with in an appendix  the method is
extended to networks violating the reciprocity principle
   /
6440
reciprocity relations in active terminal elements  it is shown by
matrix analysis that under small signal conditions an active element
such as a valve or transistor can be represented by an equivalent
circuit comprising a triangle of resistances and a three terminal
gyrator  the active element is stable if one ad only one of the resitances
is negative  it is shown that the property of nonreciprocity
is essential for an active three terminal element to be stable
   /
6441
notes on the gyrator problem  the impedance transformation properties
indicated by tellegen of as characteristic of the gyrator can also
exist in ordinary quadripoles  the peculiar nature of the gyrator
is indicated by the sign of the output current  different conventions
used in representing quadripole currents and voltages are discussed
it is proposed that the equations should be written in a way that
takes into account the terminating impedances and the internal impedance
of the source
   /
6442
solution of the field problem of the germanium gyrator  analysis
is presented for the hall effect gyrator described by mason et al
of treated as a two dimensional boundary value problem and assuming
that only one type of carrier is involved and that there is no surface
recombination  the efficiency is calculated as a function of electrode
size shape of boundary and magnetic field strength  some of the results
have been checked experimentally with fields up to gauss  the calculations
have been carried out for even higher fields and may be useful
for studying materials with higher mobilities such as
   /
6443
impedance transformation by four terminal networks  the geometrical
interpretation of impedance transformations is considered in relation
to the use of impedance charts and improved methods of impedance
measurement
   /
6444
intrinsic stability conditions for equivalence between a quadripole
including active elements and a passive quadripole  there are two
necessary conditions image impedances must be passive image attenuation
must exceed the value of a certain function of the phase angle of
the image impedance and the image phase shift coefficient in certain
important cases this second condition reduces to a simple mathematical
form
   /
6445
distortion of a frequency modulated wave passing through a mismatched
quaripole  analysis is based on the transfer coefficient of the network
and a formula is derived for nonlinear distortion in the general
case from this the percentage of odd and even harmonics generated
and the upper limit of the distortion factor can be determined  application
of the formula in the case of transmission lines is illustrated
   /
6446
transient response in fm  correction to a paper abstracted in of
august
   /
6447
response of a low pass or band pass filter to a voltage whose instantaneous
frequency varies linearly as a function of time  analysis is
given based on a fourier integral representation of the input voltage
a formula derived for the output voltage is shown to be applicable
in the case of a panoramic receiver in which the frequency is varied
by in
   /
6448
conformal mapping for filter transfer function synthesis  correction
to paper abstracted in of february
   /
6449
on the filter problem of the power spectrum analyzer  in an analyser
for determining the power spectrum of random noise a signal derived
by repeating a finite sample of the noise record is d heterodyned
with another signal whose frequency is swept over the whole spectrum
and the resultant is passed through a narrow filter and then detected
an investigation is made of the optimum filter response for minimizing
the intrinsic error associated with the finite size of the sample
the lowest probable error for various types of filter is tabulated
the rate of the frequency sweep must be small compared to the half
bandwidth squared for the filter response to remain substantially
the same as its steady state response
   /
6450
the bridge stabilized transformerless oscillator with complex amplification
factor  oscillators of the type described by zaiser of with
rc frequency determining circuits are discussed  the effect of complex
transfer factor is investigated and the conditions are determined
under which oscillations at unwanted frequencies are suppressed without
impairing the frequency stability of the wanted oscillation
   /
6451
frequency stable lc oscillators  literature on the subject is reviewed
and attention is drawn to the chronological order of various publications
simple theory is presented for the conditions governing oscillation
and frequency stability
   /
6452
the type beam deflection tubes as a complex pulse generator  type
is the usa designation for the type valve of and  circuits for producing
single double or multiple pulses with very short rise time are described
   /
6453
contribution to the mathematical description of relaxation oscillations
differences and similarities between oscillations of relaxation and
of van der pol type are discussed  relaxation oscillations can be
represented by the van der pol equation if th self inductance term
in the latter is neglected and a suitable transformation is made
   /
6454
kilovolt delta function generator  a pulse is generated in a circuit
comprising two series connected hydrogen thyratrons arranged to constitute
the inner conductor of a coaxial line  it is passed through of
cable to a delta function generator which includes a pulse sharpening
gap and differentiating stub  this generator reduces the pulse rise
time to and the pulse width to mus  pulses of ither polarity may
be obtained
   /
6455
analysis of junction transistor audio oscillator circuits
   /
6456
a clipper with automatic mark space ratio control  a rectangular
wave with mark space ratio independent of the amplitude and harmonic
content of the input wave is produced by controlling th bias level
of the first clipping stage by means of a special feedback circuit
incorporating a mark space ratio discriminator
   /
6457
distributed amplifiers some new methods for controlling gain frequency
and transient responses of amplifiers having moderate bandwidths
   /
6458
high frequency compensation of rc amplifiers  a discussion with special
reference to transient response  optimum values are tabulated for
the circuit parameters for some typical circuits and compensating
arrangements  in a multistage amplifier simply compensated by means
of a coil in the anode leads the rise time can be reduced to of the
uncompensated value if the time constants of the stages are equal
and to if the time constants are staggered
   /
6459
design of the duplex feedback amplifier  a comprehensive discussion
illustrated by a detailed account of the design of carrier telephone
repeater amplifiers
   /
6460
the galvanomagnetic amplifier  discussion of theoretical and practical
aspects of an amplifier whose operation depends on the magnetic control
of electrical resistance gauss effect  such an arrangement is less
noisy than magnetic or dielectric amplifiers at low temperature
among metals bismuth exhibits the greatest sensitivity to this effect
by using an appropriate material such as insb the principle can also
be applied to amplifiers for ust at room temperature  the theoretically
possible gain is db at and db at corresponding values which have
bee obtained with experimental units are about and
   /
6461
reflex klystron performance  from a series of measurements made while
varying the anode and reflector voltages simultaneously constant
frequency and constant power curves can be constructed  typical curves
for three modes of operation t are shown  with the aid of these curves
extremely pure amplitude or frequency modulation can be achieved
by varying and simultaneously so that the ratio of their variations
is constant the change from am to fm may be effected simply by altering
the ratio  the maximum frequency shift with am was about  with fm
a frequency swing of was obtained with constant power output of
an important application of the systems described is the modulation
of signal generators for measurement purposes
   /
6462
a broadband low level error voltage detector  the unbalance of a
carrier frequency voltage in a bridge circuit having two inductive
and two ge diode arms is used for detecting small dc or ac error
signals  sensitivity down to and response within are provided by the
instrument which is relatively free from zero drift  application
to high speed multichannel sampling and to servo systems is discussed
   /
6463
direct coupled transitron  transitron arrangements are discussed
in which the screen grid and suppressor grid of the pentode are connected
via a resistance network  various practical applications are possible
as a result of a discontinuity in the characteristic  circuits for
detection of direct voltage changes eg amplifier gain alarm detection
of alternating voltage changes eg peak suppressors and rectification
of voltages exceeding a given level are considered  careful design
is necessary to overcome variations between individual valves but
a very sharp trigger action can be produced  the high sensitivity
makes circuit economies possible
   /
6464
microwave single sideband modulator using ferrites  the modulator
uses a ferrite rod inserted in a waveguide section and subjected
to a rotating transverse magnetic field as a phase shifter  a transmission
type and a reflection type are described both are designed to
shift the frequency of an x band signal by
   /
6465
small transformers and inductors  there has long been the need for
a book which treats the design of transformers for use at both power
and communication frequencies on the basis of a common systematic
theory and which so closely relates the design process to fundamental
theory as to enable the non specialist successfully to undertake
the design of transformers for widely differing applications  the
author has fulfilled this need most admirably
   /
6466
on the nature of waves  critical discussion of classical theory indicating
how an interpretation of the quantum theory can resolve the incompatibility
of wave and particle concepts
   /
6467
thermodielectric effect  a theory is put forth to explain the electrical
effects which accompany phase changes occurring in dielectrics and
aqueous solutions ionic movement in the interface is treated as a
transition between energy levels separated by potential barriers
the height of the barriers and the value of the energy levels are
supposed to be diferent for positive and negative ions  such a model
results in a net current flow across the solid liquid interace  when
the interface moves during a phase change of the system the excess
electric charges thus produced constitute space charges in the solid
and surface charges in the liquid  see also of september and back
references
   /
6468
a new classical theory of electrons part  the theory previously proposed
and of is applied to a system comprising several interpenetrating
streams of electricity moving in accordance with the equations of
maxwell and lorentz  an action principle is set up and the equations
of motion are put in the hamiltonian form  the hamiltonian has some
similarity to that for point charge electrons but there is some discrepancy
   /
6469
a theory of the electron  further development of the theory proposed
previously of
   /
6470
the electric field of conductors arranged parallel to conducting
planes intersecting at a given angle  convenient formulae are obtained
by considering the field as the resultant of those due to the multiple
reflections of the conductor in the intersecting planes  these formulae
are shown to agree with those derived by the method of conformal
transformation
   /
6471
some measurements of the relative dielectric strength of gases  electronegative
gases including sf and were studied by measuring the breakdown
voltages of sphere gaps with spacings of a few millimetres  results
are tabulated and discussed taking nitrogen as comparison standard
   /
6472
anomalous electron scattering in metals  a semi theoretical equation
was proposed previously to account qualitatively for the thermoelectric
power of metals and alloys particularly at low temperatures  the
consequences of this equation are now examined quantitatively in
relation to experimental data on alloys of copper
   /
6473
electron energy distributions in stationary discharges  extension
of previous analysis of to the case of a stationary discharge in
a dc space charge field  the effect of the space charge is to increase
the proportion of high energy electrons  this results in a higher
ionization rate but the effect is not large enough to account for
low maintenance potentials observed in positive columns and in microwave
discharges in inert gases
   /
6474
electron emission from cold metal surfaces at medium field strengths
measurements were made of the field emisson of an fe cathode at pressures
torr  the emission field strength characteristic depends largely
on the pre treatment of the cathode material  applying schottkys
equation a value of is obtained for the work function
   /
6475
energy and temperature dependence of the secondary emission of mo
the results reported by johnson and mckay of january are interpreted
quantitatively on the basis of a simple one dimensional model
   /
6476
collisional effects and the conduction current in an ionized gas
a note on the approximate expression derived by westfold of january
for the collision term in the current transport equation for a binary
ionized gas in a strong magnetic field
   /
6477
maxwellian approximation to the general magnetoionic theory of plasmas
with an external electric and magnetic field  analysis is presented
to show that a maxwellian distribution of electron velocities occurs
as a particular case in the theory developed previously of august
and back references
   /
6478
variation of diffusion after effect field with induction  as a consequence
of the different behaviour of and walls the curve representing
the variation of diffusion after effect field with induction exhibits
two horizontal regions this is confirmed experimentally
   /
6479
general formulae for the theory of polarized media  the classical
equations of electromagnetic theory are generalized and are all derived
from two fundamental formulae by a chain of definitions and identities
   /
6480
reaction concept in electromagnetic theory  a mathematical definition
is given of a physically observable quantity termed the reaction
which is a measure of the force exerted by one em source on another
the concept is used to obtain expressions for scattering coefficients
transmission coefficients and aperture impedances  the advantage of
using this concept rather than the variational approach is illustrated
by treating the problem of scattering by a dielectric body
   /
6481
some consequences of the theory of action at a distance in classical
electrodynamics  the energy taken by a free charge and by a harmonic
oscillator is calculated on the absorber theory
   /
6482
electromagnetic field of a dipole source above a grounded dielectric
slab  a theoretical investigation using the method of integral transforms
solutions in integral form are evaluated asymptotically by the
saddle point method the distant field is found to be the resultant
of a spherical space wave and a cylindrical surface wave  calculated
radiation patterns for some particular cases with and without the
dielectric slab are presented
   /
6483
faraday effect at centimetre wavelengths  a brief note on faraday
effect measurements at cm at field strengths up to oersted using
a pole symmetrical waveguide system not described  results of measurements
on and are presented graphically
   /
6484
on the nature of the transcendental curves associated with the relativistic
trajectories of charged particles  analysis applicable to particles
with moderate relativistic velocities at which radiation loss is
negligible  the equations of the e trajectory are formulated for
the general case of particles injected with arbitrary velocity into
crossed electric and magnetic fields  the case of zero injection
velocity is calculated explicitly  see also below
   /
6485
multiple element interferometer for locating sources of solar noise
at  the interferometer uses five aerials each with a paraboloidal
reflector of diameter arranged at intervals of m  the distribution
of brightness observed at over the quiet sun is consistent with the
conclusions that the diameter of the rf disk is about greater than
that of the optical disk and the outer ring is about times brighter
than the optical disk of uniform temperature about
   /
6486
a method for the measurement of the distance of radio stars  the
method described depends on the absorption of the radiation from
the radio stars by interstellar hydrogen at a frequency of about
preliminary results are given for the two intense sources in cygnus
and cassiopeia the distance of the former is parsecs that of the
latter is probably between and parsecs  the uncertainty will be reduced
when more accurate measurements are made of the absorption spectrum
   /
6487
on the nature of the discrete radio sources  correction to paper
abstracted in of august
   /
6488
the distribution of great and small geomagnetic storms in the sunspot
cycle  a statistical analysis of the occurrence of great geomagnetic
storms small storms with sudden commencements and small storms without
sudden commencements during the last seven sunspot cycles  distribution
curves for and agree closely with the averaged sunspot curve  for
the curve has no pronounced peak at sunspot maximum but reaches a
high level two years later these post maximum storms which are associated
particularly with ionospheric disturbances often show a recurrence
which is not observed with the ad types
   /
6489
the aeronomic problem of oxygen dissociation  the vertical distribution
of o above km as determined from rocket data is discussed in terms
of diffusion ad mixing processes
   /
6490
group height calculations in the presence of the earths magnetic
field  a method of obtaining a theoretical curve avoiding direct
numerical integration is described  it is based on integral formulae
involving the derivative of height with respect to electron density
and obtained as special cases of the gauss christoffel quadrature
formulae involving the derivative of height with respect to electron
density and obtained as special cases of the gauss christoffel quadrature
formula of and of july  application to linear parabolic cosine
and arc cosine distribution is illustrated and results are compared
with exact calculations and of shinn and whale and of may shinn
a different method is described for the case of layer penetration
   /
6491
the vertical distribution of electrical conductivity in the upper
atmosphere  data obtained from rocket measurements are used to determine
the vertical distribution of conductivity and its height integrated
values for the d e and f regions  the greatest conductivity value
is found for the e layer around hence this region is probably the
seat of the electrical currents producing diurnal magnetic variations
   /
6492
on the law of the variation of e region maximum with the zenith distance
of the sun  analysis of e records obtained at calcutta for the years
indicates that the value of n in chapmans formula varies between
and  the subsolar frequency undergoes similar variations  a seasonal
component of variation was almost marked in and and the mean trend
of the variations follows the sunspot cycle  the departures from
the chapman law are attributed to changes in the height distribution
of o in the transition region
   /
6493
the sporadic e layer at kodaikanal  examination of ionospheric records
shows that an e layer is almost always pesent during the day  two
main types are distinguished a patchy type giving well spread echoes
this occurs more regularly and frequently has a marked diurnal variation
and resembles the constant height type observed at brisbane by mcnicol
and gipps of a blanketing type occurring mostly during the afternoon
neither meteoric nor thunderstorm activity greatly influences the
formation of either type  no correlation iis observed between f and
the geomagnetic field
   /
6494
spread f over hawaii  analysis of records for the period showing
diffuse and irregular echoes from the f region indicates a much greater
frequency of occurrence of spread f at sunspot minimum than at sunspot
maximum this difference being most pronounced in winter  a marked
latitude and a less marked longitude effect are exhibited
   /
6495
f scatter at huancayo peru and relation to radio scintillations
analysis of records for the period reveals marked diurnal seasonal
and annual characteristics of f region scatter  this effect occurs
most frequently in th period four hours before to four hours after
midnight and is most prevalent during local summer  occurrence frequency
was least during increasing by a factor of by  diurnal variations
correspond closely to reported characteristics of radio star scintillations
annual and seasonal trends are not in simple agreement
   /
6496
the connection between lunar height changes and lunar currents in
the e layer  height changes produced by vertical electronic diffusion
in the presence of negative ions are considered  application of the
results to the e layer confirms the validity of previous qualitative
conclusions of
   /
6497
the analysis of fading records from spaced receivers  fading records
obtained in investigating ionospheric winds by the spaced receiver
method described by mitra of and phillips o are discussed  considerable
variability in the records is to be expected even if the wind is
constant in both direction and magnitude  two particular one hour
records for vertical incidence reflection from the e layer are analysed
one is consistent with constant wind conditions the other requires
more detailed analysis
   /
6498
the determination of the velocity of winds from spaced dfading experiments
more detailed analysis referred to in above  if some assumption
is made about the distribution of signal amplitude over the ground
the statistics of wind variation can be deduced
   /
6499
systematic wind measurements at altitudes of km using radio echoes
from meteor trails  wind drifts of ionized meteor trails were measured
using a coherent pulse doppler technique at a frequency of  average
wind speeds and directions were obtained over hourly intervals results
for september and october show semidiurnal and diurnal wind components
corresponding to a clockwise rotation of the wind vector  the amplitudes
and phases of these components are variable  a prevailing wind was
also found towards the east in september and towards the west in
october  there is a positive wind velocity gradient of sec between
and height  large irregularities in the wind were noted  typical
records are shown and the equipment is described
   /
6500
an apparatus for the detection of weak ionospheric echoes  fm apparatus
id described in which the principle of coherent integration is applied
in the receiver  with transmitted power of and filter bandwidth of
signals are detected with attenuation of up to nepers
   /
6501
ionospheric absorption measurements during a sunspot cycle  detailed
discussion of the results of the results of measurements referred
to in of  variation of atmospheric absorption with frequency where
is the effective ionospheric reflection coefficient is accounted
for by magneto ionic theory provided that where is the electron collision
frequency and is the gyrofrequency corresponding to the vertical
component of the geomagnetic field  examination of diurnal variation
shows the average value of n in the relation where is the solar zenith
distance to be against the value given by simple theory possible
explanations of this are considered  excessive absorption on certain
groups of days during th months november february is directly correlated
with the occurrence of sporadic reflecting strata below e layer height
noon measurements over years show a general correlation of log with
sunspot number r more pronounced in summer than in winter  general
conclusions drawn are that the normal absorbing stratum is located
in the d region and sudden disturbances associated with solar flares
are probably due to increased ionization in this layer
   /
6502
magnetic disturbances sporadic e and radio echoes associated with
the aurora  data obtained from simultaneous observations of visible
aurora the earths magnetic field variations vertical and oblique
propagation radio echoes and vhf radar echoes are examined  long
rang hf and vhf echoes cannot in general be correlated  reflections
in both frequency ranges have coincided with the appearance of low
level auroral arcs which are associated with magnetic bays
   /
6503
radio echoes during aurora  saskatoon data for and of currie et al
are reassessed  two aerials placed at heights giving maximum resolution
between corresponding to first and second lobe radiatin were used
to determine whether echoes on were due to ground scatter reflected
from the lower ionosphere of harang and landmark  results show that
practically all echoes were due to direct reflection from aurorae
   /
6504
long range radio echoes from auroral ionization  echoes believed
to be from auroral ionization are consistently observed using pulse
signals on frequencies and at the relatively low latitude of stanford
california  two types of echo are distinguished discrete of very
large amplitude and diffuse of much smaller amplitude  echo data
show a marked correlation with visual aurorae and with magnetic activity
and also indicate that reflections occur at regions well above the
e layer
   /
6505
the location of the auroral absorption zone  a study of data from
a chain of radio wave field strength recording stations along the
meridian suggests that the auroral absorption zone coincides with
the zone of maximum frequency of occurrence of visible aurora  the
significance of the results for radio communications across the zone
is discussed
   /
6506
the behaviour of standard cells in conditions which include the generation
of appreciable current  measurements made on weston type standard
cells generating currents of or for varying periods of time are reported
from which the voltage stability attainable under these conditions
may be estimated
   /
6507
transistors and junction diodes in telephone power plants
   /
6508
transistor power supply for geiger counters  a unit is described
comprising junction transistors in a class c amplifier circuit operating
from a battery and supplying at
   /
6509
bias supplies for direct coupled circuits  details are given of power
supply arrangements using special transformers with low shunt capacitance
thus permitting operation at above earth potentials in direct
coupled amplifiers
   /
6510
stabilized hv power supply  application to millimetre wave klystrons
a circuit is described in which the series stabilizer valve is inductively
coupled to the error amplifier  an output of at can be provided
   /
6511
solar thermoelectric generators  physical characteristics relevant
to their usefulness for thermocouple materials have been determined
for various metal alloys and compounds  the efficiencies of flat
plate type solar energy collectors in combination with such thermocouples
is evaluated the value of obtained using type alloys in combination
with a bi alloy was ten times as great as that obtained with commercially
available chromel p in combination with constantan  using concentrating
lenses the efficiency obtained with the best alloy combination
was  the maximum economically permissible cost of thermo electric
generators is evaluated
   /
6512
leo lyons electronic office  a detailed account of the installation
the nucleus of which is a digital computer developed from the edsac
operation maintenance and fault finding procedure are described
an extensive system of marginal checking has been included  punched
tape read photoelectrically is used for the input errors in perforation
are completely eliminated by use of a special checking device
   /
6513
amplitude comparator for computing purposes  a simple circuit is
described which gives uniform output pulses for a large range of
input signal derivatives  low transformer output impedance is provided
measures are indicated for ensuring stability when the signals are
slowly varying
   /
6514
some applications of elements with discontinuous operation in analogue
computation  the field of application of the differential analyser
is enlarged by incorporating amplitude comparators and electronic
switches  solution of particular differential equations is discussed
   /
6515
multiplier for analog computers  multiplication is performed by addition
of logarithms using the linear to logarithmic converter described
previously of howard et al followed by a logarithmic to linear converter
application to solution of nonlinear differential equations is
described
   /
6516
analogue computers in aircrew training apparatus  comparison of the
relative complexities of full flight simulator computers using digital
and analogue methods indicates the analogue type to be more suitable
operation and performance are discussed
   /
6517
construction and calibration of a very high frequency transformer
a matching device for insertion in a coaxial line consists of a pair
of rings which can be slid independently along the line between the
inner and outer conductors without touching either of them  the frequency
range for the type described is  theory is developed on the basis
of the equivalence of the device to a cascade connection of two loss
free quadripoles
   /
6518
component design trends fixed resistors show stability improvements
a survey of available types temperature voltage and power limits
are discussed  composition resistors continue to be the most generally
used  developments in pyrolytic carbon film printed wire wound and
metal film types are reported
   /
6519
surface resistors for centimetre wave technique  an account is given
of the development of a method of manufacturing carbon layer resistors
for waveguide attenuators and nonreflecting terminations using a
colloidal suspension of graphite and an insulating base of pertinax
consideration is given to the choice of medium water or alcohol
and the method of application painting dipping or spraying particular
importance is attached to the uniformity of the layers  the resistance
layer is protected by a coating of polystyrene  an instrument designed
for measuring the dc resistance of the layers is described  measurements
at dc and at are reported
   /
6520
theory of the thermistor as an electric circuit element  a study
of thermistor circuits  fundamental relevant physical and mathematical
concepts are presented the dissipated poer rather than the thermistor
temperature is taken as th basic variable  the power balance equation
is presented in a form introducing the thermal time constant and
is used to develop equivalent circuits for thermopositive and thermonegative
resistors permitting calculation of superposed variable states
   /
6521
nonlinearity of the volt ampere characteristics of silicon carbide
resistors  results of an experimental investigation of the conductivity
and conductivity and conductivity voltage characteristics of sic
powders under a pressure of show that as the field strength increases
the conductivity becomes proportional to the square root of the field
strength this is probably due to an increase of the effective area
of contact  electron micrographs of typical sic crystal surfaces
are shown  results obtained using crystals graded according to size
are shown graphically and are discussed from the point of view of
producing a resistor with the greatest possible nonlinearity
   /
6522
fundamental oscillations of coils and windings  analysis is given
based on the solution of a fredholm integral equation  fundamental
frequencies are evaluated for air core and iron core coils and iron
core coils and the voltage distribution is discussed  see also of
march
   /
6523
saturable transformers as gates  use of ferrite cored units as switching
elements is discussed input and output windings are wrapped on each
core and control windings are wrapped around both  applications include
magnetic drum read out systems for computers
   /
6524
multistable electronic circuits and decades  the design of counter
circuits is considered from the point of view of simplicity and reliability
from this point of view it is advantageous to keep the number
of internal couplings as low as possible  trigger chains are used
with odd numbers of triode valves alternately blocked and conducting
except for one adjacent pair in the same state  to ensure stability
damping is required at the critical frequency circuit arrangements
are shown for providing this in cases where the two adjacent valves
in the same condition are both blocked both conducting
   /
6525
a sensitive pulse trigger circuit with a stable threshold  a pulse
amplitude discriminator for positive or negative pulses is described
in which the sensitivity is independent of contact potential variations
in the valves  with a threshold of stability is within  the simplified
circuit comprises two triodes passing steady currents and a clamping
diode operated under retarding field conditions  the minimum effective
pulse width is about the same as that for conventional discriminators
performance figures substantiate theoretical calculations of sensitivity
   /
6526
a scaling unit employing multi electrode cold cathode tubes  a complete
scaling unit for counting regular of random pulses id described  different
methods of driving cold cathode scaling valves are considered
in the method uses the amplitudes and durations of the pulses applied
to all stages in the slow scaling section are controlled by a common
pulse generator  the unit comprises a pulse amplitude discriminator
of high sensitivity a fast scaling stage with a element valve a cascade
arrangement of element vales type with cold cathode gating valves
and the pulse generator  some routine tests for valve deterioration
are outlined
   /
6527
empirical transient formulae  relations between the steady state
frequency response of a network and its transient response are derived
in terms of shape parameters the most important of which for the
transient response are rise time overshoot and relaxation time  two
classes of network are considered those with a flat topped frequency
response curve with a single peak at zero centre frequency and those
whose frequency response curve exhibits two equal maxima located
symmetrically about x zero centre frequency  it is concluded that
the network giving most failful reproduction of a unit step has a
trapezoidal frequency response curve and that compromise is required
in design as between ideal frequency response and ideal transient
response
   /
6528
nyquists criterion  nyquists form of the stability criterion is deduced
using well known properties of complex numbers and without using
integration in the complex plane  a new form of criterion the minimum
phase criterion is also developed
   /
6529
a note on the transfer voltage ratio of passive rlc networks  results
obtained by failkow and gerst of are generalized to include rlc networks
   /
6530
symmetrical quadripole lattice networks  determination of pass bands
an attenuation bands  a graphical method of determining the bands
is discussed  see also of leroy
   /
6531
some passive networks under transient conditions  two groups of passive
quadripoles are defined by their transfer functions those approximating
to an ideal delay line those producing a gaussian waveform from an
input pulse of sufficiently short duration  a method of synthesizing
such networks given the attenuation and phase shift coefficients
is based on a continued fraction expansion of the quotient of a hypergeometric
function
   /
6532
the four circuit filter with coupled circuits of equal resonance
frequency  the properties of the circuit are analysed and compared
with those of two stage and three stage filters
   /
6533
methods for the calculation of transient distortion based on the
general properties of transfer functions  theories of transients
in filters developed by kupfmuller wheeler and cotte are compared
cottes method of calculation is considered most suitable for the
general investigation of transient distortion  a definition of bandwidth
is proposed it is shown that in the general case there is no simple
analytical relation of the type derived by kupfmuller between bandwidth
and rise time  see also of
   /
6534
universal formulae for the calculation of simple filters  transfer
properties and input impedance are given as functions of normalized
frequency for filters with up to four tuned circuits for arbitrary
ratio between source impedance and terminating impedance the calculations
take account of circuit losses  the formulae are evaluated and
represented in curves  details of the calculation are shown for a
four circuit and pass filter  a table is given of the most important
filter circuits with the associated formulae and definitions
   /
6535
analysis of a special purpose rc filter incorporating a periodically
conducting bilinear element  the circuit discussed is essentially
a low pass filter incorporating a two way switch  modulated carrier
is applied and the switch is operated at carrier frequency so that
the output is a series of amplitude modulated pulses  analysis is
presented based on consideration of the stepwise accumulation of
charge by the capacitor and taking account of the dead time when
the switch is out of contact  application in the field of automatic
control is mentioned
   /
6536
band pass circuits with minimum number of coils  part band pass filters
with prescribed attenuation characteristic  any band pass filter
with the exception of the equalized characteristic impedance type
can be constructed using a suitable combination of the basic filter
sections described  by transforming parts of the filter using the
circuit equivalents given th number of circuit components can be
reduced this is illustrated by a numerical example
   /
6537
on the transformations of singularities and limit cycles of the variational
equations of va der pol  cartwrights solution of van der pols
equation with forcing term of is shown to be incorrect in one range
of the parameters the corrected solution is given  in view of the
correction the hysteresis effects to be expected for a van der pol
oscillator with increasing and decreasing frequency are confined
to a narrower frequency interval and are less varied in character
than suggested by cartwrights solution
   /
6538
wien bridge oscillator design  comment on of
   /
6539
modes of operation of a valve oscillator  the operation of a tuned
grid oscillator is described mathematically by the differential equation
where is proportional to the capacitor voltage is the derivative
of the anode current with respect to and and are constants dependent
on the circuit parameters  the equation is solved assuming to be
small
   /
6540
fluctuations in oscillator with inertial nonlinearity  fluctuations
in a valve oscillator the steady state amplitude in which is determined
by an inertial nonlinearity such as a feed back system are considered
theoretically and some practical conclusions are reached on the choice
of circuit parameters for minimum amplitude fluctuations
   /
6541
vertification of a descriptive theory of relaxation oscillations
the conditions for oscillation previous of november are verified for
the case of an oscillator using a neon lamp or a thyratron
   /
6542
new circuits for generating pulses by means of a pulsed reactor
review of circuits containing a saturable reactor with rectangular
magnetization characteristic for deriving pulses of required amplitude
and phase from a sine wave input  the method of shifting the phase
by means of an auxiliary pre magnetizing current is described  pulse
shapes obtainable from a square wave input are discussed and practical
circuits for deriving this input from single and three phase ac are
shown
   /
6543
junction transistor pulse forming circuits  analysis of integrating
ad differentiating circuits using npn junction transistors  practical
arrangements are illustrated for obtaining sawtooth square and triangular
pulses
   /
6544
internal oscillations in transistors
   /
6545
pulse frequency multiplication and division by delay lines  analysis
is given for simple arrangements of lumped element lc lines  for
multiplication lines with linear characteristics are suitable  for
division a nonlinear device eg a pentode must be included in this
case the input may be sinusoidal
   /
6546
an amplifier with low dissipation and short rise time for crt  by
using electron multiplier valves in an amplifier for scintillation
counter pulses a gain of about and rise time of are obtained with
only a few valves  details are given of a circuit for a negative
pulse input giving an output of about
   /
6547
newly developed amplifiers for the sound programme chain  as part
of a comprehensive redesign of studio and control room equipment
to be known as type b the bbc engineering division has produced a
new group of amplifiers comprising gpa and general purpose level
ri raising amplifiers low fixed gain amplifier for sending programme
to line and for monitoring purposes  compactness and standardization
of construction are features  the preferred amplifying valve is the
double triode type or its trustworthy equivalent the type  details
are given of circuits construction mounting and performance
   /
6548
design of carrier frequency amplifiers with stagger tuned resonant
circuits  a simple rule is derived for the distribution of the poles
ad a nomogram is given facilitating the design of an amplifier with
flat response over a pass band of large relative width  analysis
is also given for the case of response ripples within predetermined
limits  values of the resonant circuit elements are calculated
   /
6549
experimental band pass amplifier  a description is given of the practical
design of an amplifier circuit in which the bandwidth can be adjusted
and the gain varied between wide limits without shifting the centre
frequency of or affecting the response curve  features of the design
are the capacitive coupling of the tuned circuits the neutralization
of the grid anode capacitance of a type pentode by means of a specially
constructed plunger type capacitor and th compensation of valve input
impedance variations by a suitable cathode load
   /
6550
a stable wide range dc amplifer  description of an ac operated differential
push pull amplifier for biological applications with a range
from zero to and a maximum gain of about  response can be controlled
independently at the high and low ends o the range the dc gain can
be reduced to of the mid band gain  an automatic rebalancing circuit
resets the zero of the amplifier at intervals of about sec
   /
6551
amplification of small alternating voltages with the magnetic amplifier
a theoretical investigation of the conditions under which saturated
reactors are suitable for amplifying sall alternating voltages  a
parallel choke circuit with self saturation was found to be suitable
and a two stage amplifier based on this circuit is described  the
amplification obtainable is sufficient to give a galvanometer indication
with voltages down to
   /
6552
the attainment of very high gain with unmatched transistors  when
a transistor is used with unmatched source or load impedance maximum
gain is achieved with a particular value of the impedance maximum
gain is achieved with a particular value of the impedance on the
other side quadripole analysis is used to determine this optimum
impedance value  with grounded base or grounded emitter circuits
the cut off frequency is the same as with matched impedance with
grounded collector circuits the cut off frequency depends on the degree
of matching
   /
6553
certain transmission and reflection theorems  established theory
is used to analyse transmission and reflection of em and acoustic
waves by a uniform planar distribution of cylinders  reflection by
a planar distribution of bosses is also considered  see also of and
back references
   /
6554
step by step transition from wave optics to ray optics in inhomogeneous
anisotropic absorbing media part group propagation  the method of
stationary phase is applied to obtain general expressions for group
delay direction and velocity which are then particularized for em
waves
   /
6555
contact charging between nonconductors and metal  the investigation
previously reported of september was continued using spheres of fused
quartz and borosilicate glass rolling n on a clean ni surface and
introducing improvements in the method  the surface conductivity
of the glass was found to be higher than that of the quartz by three
or four orders of magnitude since the charging of the two materials
was of the same order of magnitude it appears that the effective
work function of the glass is considerably higher than that of the
quartz
   /
6556
rigorous method for investigation of the interaction between an electron
and several lattice oscillators
   /
6557
electrothermal convection in air  the effect of an inhomogeneous
electric field on the thermal gradients in air was investigated using
air heated electrically by a filament of length cm along the axis
of a glass tube of diameter about cm  results show that the field
required to produce electrothermal convection is lower at high power
dissipation than at low dissipation in the range the transition between
gravitational thermal and electrothermal convection occurs discontinuously
the potential difference between the positive filament and negative
electrodes placed on either side of the filament was varied between
about and  interference photographs are shown and the apparatus used
is described  results are presented graphically
   /
6558
theory of equations of transport in strong electric fields  the transport
of heat and electricity in semiconductors is considered in terms
of an electron hole gas whose kinetic energy is greatly increased
in a strong electric field  equations for the thermal and electric
currents are derived and formulae are obtained for the thermoelectric
and galvanomagnetic effects  these include the thomson hall nernst
and nerst ettinghausen effects  effects due to bipolar conduction
of the semiconductor including the photomagnetic effect are also
considered
   /
6559
an analysis of the distribution of alternating current in a solid
cylindrical conductor  the equivalent circuit method of approach
selected is designed t keep the physical basis of th problem in view
at every stage of the work  the expressions derived apply to a conductor
of any material
   /
6560
the theory of the anomalous skin effect in anisotropic metals  the
theory of the anomalous skin effect in metals is extended to a uniaxial
metal crystal containing two energy bands in each of which the energy
surfaces are ellipsoids of revolution about the crystal axis  explicit
formulae are obtained for the extreme anomalous limit giving the
dependence of the surface impedance on the orientation of the crystal
axis both for a plane metal surface and for a circular wire  the
results are evaluated numerically for tin and the surface conductivity
of a circular wire is found to show the minimum observed by pippard
of the parameters can be chosen to give reasonable agreement with
pippards results
   /
6561
the anomalous skin effect in anisotropic metals  application of the
ineffectiveness concept of leads to the same answer as a sondheimers
exact method above for spheroidal fermi surfaces and for a two dimensional
isotropic metal  a complete solution for the general case is
given in a form which illustrates the potential value of anomalous
skin effect studies as a tool in determining the shape of the fermi
surface of a real metal
   /
6562
the anomalous skin effect and the reflectivity of metals  if the
gas of conduction electrons is subject to internal friction the resultant
energy dissipation contributes to the absorption factor of metallic
conductors this contribution can become predominant at low temperatures
if this effect is combined with those studied by dingle of september
for the case of mean free path comparable with skin depth agreement
between theory and experiment is improved
   /
6563
striated high frequency discharge  the forming of striae in ne and
ar at a pressure of mm hg by hf fields of frequencies and is described
in symmetrical hf discharge the striae are stationary but on disturbing
the symmetry eg by using electrodes of unequal dimensions the striae
are set in motion  their velocity in electropositive gas is of the
order of the drift velocity of the positive ions  both external and
internal electrodes were used in the experiments
   /
6564
theory of striae in gas discharge  equations are derived connecting the
spacing of striae with the radius of the discharge tube the diffusion
coefficient and other parameters  the calculated spacing is in good
agreement with the spacing observed by dzherpetov and zaitsev above
and others
   /
6565
the hollow cathode effect and the theory of glow discharges  the
electric field between two plane parallel cathodes was investigated
by observing the deflection of an electron beam and simultaneously
noting other discharge parameters  results show that the field in
the two cathode dark spaces falls linearly with distance from the
cathode and thus the net space charge density is constant as in a
conventional discharge  the dark sace length was also determined
the conclusions lead to a theory of glow discharges which takes account
of the effect of ultraviolet quant from the glow on the photoelectric
emission from the cathodes  the discrepancy between earlier experimental
results showing that ions of energy of the order of cathode fall
of potential arrive at the cathode and classical calculations leading
to low ion energies is resolved by allowing for small angle scattering
and charge transfer
   /
6566
electrical circuit for the direct determination of the energy distribution
function of secondary electrons  a circuit modification of the
retarding field method is described by means of which the current
voltage characteristic is differentiated this results in improved
accuracy and resolution as compared to numerical differentiation
results of measurements on a oxide caesium cathode are shown graphically
   /
6567
anomalous electron emission from tungsten heated by high current
density pulses  results of this experimental investigation using
microsecond pulses with current densities up to about show that the
instantaneous electron emission from w can exceed by a factor of
the steady saturation emission at the melting point
   /
6568
secondary electron emission from thoria  the dependence of the secondary
emission coefficient on primary electron energy and on target temperature
was determined experimentally for thoria layers of thickness deposited
on ta  the effect of pre treatment by heating to temperatures up
to is shown
   /
6569
method of investigating secondary emission in conductors bombarded
by ions  several oscillographic methods are discussed an the double
modulation method is described in detail  the ion beam is modulated
by a rectangular pulse and the secondary emission electrode potential
by a lf sawtooth pulse  the principal advantage of this method is
the possibility of separating the true secondary ions from those
produced by the heating due to the bombardment  oscillograms of the
current voltage characteristics of the secondary emission are shown
for ta and w specimens bombarded by rb ions
   /
6570
theory of probe in plasma part  an expression is derived for the
electron current into a spherical probe which is at the potential
of the space in an undisturbed electron plasma  the dependence of
the current on the probe dimensions and the electron mean free path
i is indicated
   /
6571
dipole resonant modes of an ionized gas column  a quasistatic treatment
is used to show that numerous oscillation modes are possible in a
cylindrical column of ionized gas with a rotationally symmetrical
distribution of electron concentration of electron concentration
the theory provides a qualitative explanation of the rf reflection
of em waves observed by romell of  approximate values of the resonance
frequencies are calculated assuming a gaussian radial distribution
of electron concentration some of the results may be verifiable by
meteor trail echo observations  an investigation is also made of
the finite energy loss and phase shift shown by herlofson of and others
to occur when the real part of the dielectric constant vanishes
   /
6572
a correction of the thomson formula for the coefficient of three
body recombination between electrons and ions  comment on the method
of deriving thomsons formula of pointing out two objections to the
expression used for effective mean free path
   /
6573
solution of magnetostatic problem for unbounded homogeneous anisotropic
medium
   /
6574
asymptotic evaluation of the field at a caustic  a determination
is made of the field at and near the focus when a plane em wave is
incident on a parabolic cylinder  the case of a reflector comprising
a segment of a circular cylinder is also considered
   /
6575
diffraction at a circular aperture  a discrepancy in the results
obtained by two methods of calculating the diffraction field described
earlier and of is examined  the first method is correct within the
approximation stated the second is invalid for a small region near
the centre of the aperture when the wavelength is insufficiently
small
   /
6576
theory of diffraction at a sphere taking account of the surface wave
theory developed previously of is applied to the case of a sphere
the main difference found is an abrupt phase change in the surface
wave a as it passes over either pole
   /
6577
diffraction of cm electromagnetic waves by cylindrical objects  a
brass tube and a hard rubber rrod both of diameter and length were
used as obstacles in the path of a plane pulsed wave with the electric
vector parallel to the cylinder axis  observations were made of the
diffraction patterns in planes perpendicular to the direction of incidence
experimental results for the brass cylinder are in good agreement
with calculations based on scalar diffraction theory  the patterns
for the rubber rod exhibit a pronounced peak immediately behind the
rod and differ in other ways from the patterns for the brass tube
particularly in the vicinity of the shadow  the results are compared
with those obtained by kodis of
   /
6578
the propagation of electron space charge waves in waveguides and
tubes with periodic structure
   /
6579
method for measurement of absorption coefficients by microwave spectroscopy
a technique using a modulated stark cell is described with
the aid of a diagram of the experimental set up  errors are estimated
to be less thzn
   /
6580
focusing electrified particles  a relation is found between h th
magnetic field strength and the coordinate such that the trajectories
of charged particles in the xy plane pass through both the origin
and a given point on the y axis  the particles are assumed to have
equal mass and charge  h is derived in the form of a simple series
   /
6581
physics of thin metal and semiconductor films  a survey of work on
formation structure and electrical properties of thin metal and semiconductor
films surface states and their effect on the properties of
semiconductor films theoretical work on thin metal films  the present
position is briefly but critically discussed and in particular the
points of agreement and disagreement between experimental results
and theory are noted
   /
6582
the capacitance of an anchor ring  an approximate value of where
r is the mean radius is derived
   /
6583
observations of the cm line from the magellanic clouds  first observations
of this neutral hydrogen line from an extragalactic source are
reported
   /
6584
the distribution of radio brightness across the crab nebula  interferometer
measurements were made at with aerial spacings on an axis and
on a axis  information regarding phase was obtained from independent
measurements of the position of the source  results show that brightness
distribution is symmetrical and that optical and radio centres of
the source coincide within of arc
   /
6585
the motion of magnetic fields  the temporal change of a magnetic
field cannot b described as a motion if it involves interlinking
of the lines of force  it is shown that the idea of motion can be
retained if the lines of force are regarded as being disconnected
on a suitable surface  a process is described by which magnetic flux
can be generated other than at a neutral line
   /
6586
electric field induced by vertical component of geomagnetic variations
an expression is derived for the horizontal electric fiel in the
earth due to a varying geomagnetic field assuming regions of unequal
electrical conductivities  graphs based on published experimental
determinations of the electric field components and the geomagnetic
field show typical hour cycles and indicate the degree of correlation
between the electric and geomagnetic fields  see also of
   /
6587
an effective ground conductivity map for continental united states
discussion of a map based on the sectional maps described by kirby
et al of august which has been adopted by the fcc
   /
6588
atmospheric oscillations at high altitudes and their relation to
geomagnetic field variations  equations developed previously of august
chakrabarty and pratap are used to calculate the s variations of
h ad v  by assuming different phases for the atmospheric oscillations
in the ionosphere layer which is the seat of the ring currents and
comparing the results with observed variations of the magnetic field
a phase of is found to give the best fit
   /
6589
the action of solar particles in the ionosphere  an examination is
made of typical changes occurring in the ionosphere during the penetration
of solar particles inside and outside the zone of northern lights
and martyns extension of the chapman ferraro theory is discussed
   /
6590
energy and duration of a sudden ionospheric disturbance  a study
was made of the maximum amount of energy which might be absorbed
by the atmosphere down to during a sudden ionospheric disturbance
assuming that the ionization is caused by lyman radiation from the
sun and that all oxygen present is ionized the energy absorbed by
the sunlit hemisphere is ergs
   /
6591
symposium on ionospheric storms may  the full text is given of papers
presented at the symposium
   /
6592
a theory of diurnal magnetic variations in equatorial regions and
conductivity of the ionosphere e e region  part  the electrical conductivity
of the e region is calculated in some detail for the factor
by which the tidal oscillation of the e region exceeds that at ground
level should be less than in oder to give the observed lunar magnetic
variation  the calculated lunar vertical movement of the e region
is nearly in phase with that observed in south england and nearly
opposite at canberra  a possibility is shown that the calculated
lunar vertical movement of the f region roughly agrees with that
observed  it is suggested that the vertical drifts of the f region
near the magnetic equator may be much greter than those in the other
latitudes
   /
6593
ionospheric variations associated with geo magnetic disturbances
part variations at moderate latitudes and the equatorial zone and
the current system for the sp field  variations of the e and f regions
are studied  the current system for the s field is calculated  the
ionospheric variations may be due to the effect of a vertical drift
by the earths magnetic field and the electric field of the s current
   /
6594
disturbances in the ionosphere during the geomagnetic stormof april
analysis shows that commencement of disturbances of the f layer electron
density and virtual height coincided with the commencement of the
main phase of the magnetic storm
   /
6595
characteristics of ionospheric disturbance during a sever magnetic
storm  data from ionospheric stations relevant to the storm of are
analysed and the salient characteristics explained
   /
6596
a radio astronomical investigation of drift movements in the upper
atmosphere  discussion of night time observational data of the diffraction
of rf radiation from radio stars by moving irregularities in
the ionosphere f region obtained at jodrell bank during the period
using three receiving equipments triangularly sited and operating
at  the drift velocity at temperature latitudes is normally of the
order of  during the first half eastwards the reversal occurring
around  in the auroral zone the velocity is of the order of and the
changes in direction are less marked  results for points separated
by suggest that the drift speed and directions are the same over
wide areas
   /
6597
glow of the night sky in the waveband  results are reported of energy
flux measurements made at the gorni observatory altitude m in september
the average flux per second crossing received from steradian in the
direction of cygnus varied between and units not stated referred to
a wavelength of  the apparatus used is briefly described
   /
6598
observations of the electric field of the atmosphere at monaco during the
partial solar eclipse of june  very high values of field strength
were observed after the maximum of the eclipse
   /
6599
atmospherics due to fronts in the upper atmosphere  reference to
meteorological data indicates that atmospherics observed in a zone
of the pacific ocean in latitude especially in autumn and winter
are generated in the convergence region l of fronts in the upper
atmosphere
   /
6600
the frequency response of a certain class of nonlinear feedback systems
a method is described for predicting the frequency response of feedback
systems including one single valued nonlinear element followed by
a low pass filter  the conditions giving rise to gain discontinuity
or jump phenomenon are investigated  experimental results obtained
with an electronic servo simulator justify the use of the analytical
technique
   /
6601
remote control of radio receivers  a zero seeking servo tuning control designed
for operation over a single post office telephone line is
described the signal from the tuned receiver passing along the control
lines  maximum separation is seven loop miles for underground routes
or loop miles depending on the type of cable  the circuit is essentially
a wheatstone bridge with two variable arms one of which is carried
to the remote point along the line  the detector comprises a second
harmonic magnetic modulator combined with valve amplifier
   /
6602
a stable dc source of low voltage with low internal resistance  a
mainsdriven source providing a direct voltage of constant to within
for mains voltage variations of and current drain of uses a magnetic
amplifier as an impedance transformer to provide a very low output
resistance from a gas filled reference tube type  long term stability
depends mainly on the reference tube which has a nominal drift of
per h after an aging period
   /
6603
the design of high efficiency ratio frequency eht supplies  difficulties
associated with the use of air cored step up transformers for the
production of high voltages are discussed  designs in which these
difficulties are eliminated or alleviated are obtained by using transformers
with ferroxcube cores  simple design procedure is outlined
with numerical examples
   /
6604
a current stabilized photomultiplier power supply  stabilization
is based on the series connection of two cathode followers  tests
on the circuit are reported voltage is maintained constant to within
one part in
   /
6605
selenium rectifier disks as voltage dependent resistors for amplification
of fluctuations of a component voltage and voltage stabilization
particularly amplitude limiting
   /
6606
investigation of rectification properties of se hgse contact  the
experimentally determined rectification coefficient maximum occurring at
is for pure se and for se  current voltage characteristics were investigated
for rectifiers with the hese prepared by exposing se to hg
vapour or to liquid hg se crystallized at various rates and temperatures
various electrode base materials and se of two different grades of
purity  the results are shown graphically
   /
6607
asymmetry in conductivity of some selenides  the experimentally determined
current voltage characteristics of a cuse me rectifier are discussed
the ratio of reverse to forward current varies between and the
power handling capacity is and the blocking layer is stable even
at  the principal disadvantages of this rectifier are the large hysteresis
effect and the de forming after prolonged storage  other selenides
and selenide metal combinations are briefly noted
   /
6608
universal circle diagrams for certain radio syst systems  when the
q of a system eg a lecher line is nearly constant over the pass band
circle diagrams similar to those previously obtained for quartz crystals
of can be established
   /
6609
transistors part  discussion of transistor equivalent circuits analogies
between transistors and electronic valves practical transistor circuits
noise operational frequency limits  part
   /
6610
transistor oscillators  detailed discussion of various transistor
circuits including different types of sine wave generator relaxation
oscillators and a combination of the two giving self quenching oscillations
or stabilized frequency division
   /
6611
frequency stabilization in the microwave range  descriptive review
of different methods including those using frequency discriminator
circuits and spectral line systems
   /
6612
production control of printed resistors  factors affecting the reproducibility
of resistors produced by the silk screen process are discussed
those requiring especially careful control are carbon concentration
squeegee speed temperature of application curing schedule and application
of protective coating
   /
6613
electronic switching elements for communications engineering  a review
of the characteristics of available glow discharge tubes thermistors
thyratrons transistors and multi electrode counter tubes with discussion
of their possible applications in telephony circuits
   /
6614
new trigger circuits for use with cold cathode counting tubes  a
description is given of several trigger circuits devised for use
particularly with dekatron tubes of bacon and pollard  the circuits
can be used in the construction of a scaling unit which can subtract
as well as add  the counting losses of such a unit when used on random
pulses are considered
   /
6615
high speed counter uses ternary notation  the basis of the counter
is a flip flop circuit modified to have three stable states by insertion
of a diode coupling circuit between the cathodes  a nine stage circuit
is described operating reliably up to counts of per sec  the indicating
system may use either one or two lights per stage
   /
6616
rf characteristics of capacitors  comment on of
   /
6617
development of vacuum capacitors  vacuum capacitors are particularly
suitable for hf hv operation in airborne radio equipment  an account
is given of the development of two types one having a capacitance
of within at a peak working voltage of the corresponding figures
for the other being and  electrical and mechanical test methods are
outlined
   /
6618
resonance characteristics by conformal mapping  the expression where
is termed the resonance function  it represents the impedance of
the series connected lrs circuit or the admittance of the parallel
connected circuit to  conformal mapping of the plane on to the plane
gives a figure which illustrates the meaning of the resonance function
for complex frequencies  typical examples illustrate the application
of the figure to the parallel circuit and to one of its intrinsic
generalizations  the mapping of the reciprocal functions and is also
considered
   /
6619
networks with maximally flat delay  corrections to paper noted in
of
   /
6620
waveform computations by the time series method  the time series
method greatly reduces the work of computation in the solution of
waveform or transient response problems of cascade connected linear
quadripoles  practical procedures for dealing with time series are described
and illustrated by numerical calculations relating to waveform
tests on a mile coaxial cable television link with a nominal upper
cut off frequency of
   /
6621
the numerical calculation of filter circuits with generalized parameters
using modern theory with special attention to cauers work  corrections
to paper abstracted in of
   /
6622
the transmission range of two circuit band pass filters particularly
for large bandwidths  graphical methods of calculation are developed
which give results with accuracy adequate for practical purposes
the methods are applicable to unsymmetrical and wide bandfilters
and also to narrow band symmetrical filters
   /
6623
synthesis of narrow band direct coupled filters  a general synthesis
procedure is described that is based on an approximate first order
equivalence between direct coupled and coupled filters  the transmission
characteristics computed for a cavity filter with an overall q of
are in excellent agreement with measurements
   /
6624
a frequency eliminating transconductance bridge  description of a
bridge circuit which completely eliminates a single frequency component
n and also partially suppresses a band of frequencies whose width
can be varied within wide limits by suitable choice of circuit parameters
applications to ripple elimination n and to band elimination
amplifiers are discussed
   /
6625
optimum filters for the detection of signals in noise
   /
6626
the detection of a sine wave in the presence of noise by the use
of a nonlinear filter
   /
6627
a general network theorem with applications  it is proved that in
a network configuration with branch currents i satisfying the node
equations and branch voltages satisfying the mesh equations summed
over all branches is zero  using this result it is possible to prove
the energy theorem and the reciprocity relation of networks and to
show that if arbitrarily varying voltages are applied to a pole network
at rest the difference between the electric and the magnetic energy
at any instant depends only on the admittance matrix of the pole
network and not on the particular network used to realize this matrix
   /
6628
the utility factor in circuit diagrams  the importance is stressed
of laying out circuit diagrams so that the working of the circuit
can be easily and clearly grasped  the common type of drawing office
diagram may look neat but usually requires to be radically rearranged
to indicate circuit functions  it is suggested that circuit diagrams
should be drawn on the same general plan as block diagrams a standard
lay out being used for common sub circuits and only lines carrying
signals being included
   /
6629
negative feedback tone control  the circuit described provides independent
control of bass and treble response without switching  the rc
arrangement on each side of a bass control potentiometer is made
symmetrical so that it may be combined in the feedback line with
a treble control circuit the potentiometer of which has an earthed
centre tap  at medium and high frequencies p is effectively shorted
with both potentiometers at a middle setting response is level
   /
6630
parallel tuned circuit periodically switched to a direct current
source  circuit phenomena with the switch closed open are analysed
in turn linear solutions being obtained  the complete solution is
then obtained by matching the boundary conditions for the two cases
this solution includes sinusoidal sawtooth and complex waveforms
dependent on circuit parameters and switching period  elimination
of dissipative circuit elements simplifies the general solution with
resulting clarification of the operation of the circuit  tests with
a mechanically switched circuit verified the theory the entire gamut
of waveforms being obtained by variation of circuit parameters and
switching period
   /
6631
on the scattering matrix of symmetrical waveguide junctions  fundamental
properties of the scattering matrix are derived  tomonagas theory
for lossless resonant structures is extended to include the effect
of losses  the structural symmetry of microwave circuits is discussed
junctions consisting of two parallel sections of rectangular waveguide
with one side common being particularly considered  the theory of
directional couplers with such symmetry is developed  an attenuator
and standard matching transformer each having a directional coupler
as a basic unit are described  other forms of resonant coupling are
discussed
   /
6632
national electromagnetic oscillations in a rectangular cavity with
walls of finite conductivity  in the limiting case of infinite wall
conductivity the te and tm self oscillations have the same frequency
this does not hold for finite wall conductivity in which case linear
combinations of the te and tm oscillations with the same frequency
exist  these combinations termed matched oscillations represent to
a first approximation the natural oscillations of the actual resonator
the determination of the characteristics of these matched oscillations
is based on the solution of a simple geometrical problem from which
the damping and mistuning are calculated
   /
6633
oscillator systems including elements having inertia  analysis is
given for oscillator circuits both with and without valves including
elements whost resistance varies with temperature
   /
6634
amplification and bandwidth of video amplifiers  the characteristics
of the ideal amplifier with constant amplification and constant phase
transit throughout the pass band are briefly reviewed and the principal
types of amplifier are analysed with particular reference to amplification
and bandwidth  the theoretical maximum values of these parameters
are determined for the various types and compared with the values
obtained in practice and with one another  arrangements using distributed
amplification ad having very wide pass bands are considered briefly
   /
6635
a mathematical analysis of a dielectric amplifier  the fundamental
principles of operation of dielectric amplifiers are outlined and
a basic circuit with resistive load is analysed in detail  it is
assumed that the hysteresis curve of the dielectric is represented
by a hyperbolic sine function  expressions are calculated for the
steady state input and output currents and the time constant of the
amplifier is estimated from consideration of the transient response
   /
6636
high gain dc amplifiers
   /
6637
the design of a practical dc amplifier based on the second harmonic
type of magnetic modulator  discussion description of the development
of an amplifier based on the work of williams and noble of including
details of a oscillator with second harmonic distortion a low pass
filter to prevent power from the oscillator reaching the dc source
a phase sensitive rectifier switching and overall dc negative feedback
arrangements
   /
6638
a circuit for the limitation of discharge in gm counters  a two valve
feedback amplifier is used to limit the discharge to a small part
of the total length of the wire full sensitivity being restored in
about
   /
6639
electrets  general discussion of the properties of electrets  applications
in electrometers and in apparatus for detecting the presence
of radioactive radiation are noted
   /
6640
the motiton of charged particles in the magnetic field of a linear
current and the electric field of a cylindrical capacitor  the particle
trajectories for such a system are determined  under certain conditions
the system may be used for focusing beams of charged particles
   /
6641
an integrable case of electron motion in electric and magnetic field
the case is considered of a two dimensional electric field with the
potential given by applied together with a uniform magnetic field
in the direction  the path of an electron is an ellipse whose centre
moves in a hyperbola the electron may drift into regions of higher
or lower potential
   /
6642
calculation of plane electron trajectories in particular electric
and magnetic fields by means of complex vector loci  further examples
of the method previously described of include trajectories in a time
variable homogeneous magnetic field circular paths in a suitable
em field as for the betatron
   /
6643
a note on the theory of semiconductors  two different theories are
obtained depending on whether the free energy due to the spin of
electrons in impurity centres is or is not taken into account  the
second of these alternatives is essentially that adopted by wilson
and has been used almost universally though the first which is that
adopted by mott and gurney electronic processes in ionic crystals
can be applied to degenerate semiconductors and is to be preferred
   /
6644
a theory of contact noise  the outlines of a theory of contact noise
are presented based on the idea that it is due to temperature fluctuations
in the neighbourhood of the contact  detailed theory is being
prepared for publication
   /
6645
the apparent high frequency resistance of a conducting layer of finite
width parallel to an infinite plane conductor  opposing field and
induced currents  formulae are derived for the case where the conducting
strip comprises a winding with a number of separate turns
   /
6646
currents induced in a plane conductor of great width by a plane strip
of small width carrying a high frequency current  approximate formulae
giving the variations of resistance and self inductance of the inductor
   /
6647
thermoelectric measurements on p type silicon  the thermoelectric
power positive with respect to cu is about for material of purity
falling to about for purity and rising again to for purity
   /
6648
high frequency electrical breakdown of gases  theory is presented
which is applicable to any gas over a wide range of pressure  experimental
results for h r are in agreement with the theory
   /
6649
sparking potentials in a transverse magnetic field  by taking account
of the distribution of electron free paths and of electron recapture
by the cathode a theory is developed which is in better agreement
with observation than tht of valle vol
   /
6650
a resonance phenomenon in electrodeless hf gas discharges with superposed
magnetic field  experiments in atmospheres of h and ar are described
which show that the resonance effect previously noted of koch and
neuert is associated with a sharp drop between two peaks in the intensity
of the emitted light it occurs always at the same value of the
field strength
   /
6651
dimensions and units  by considering the expression for power in
terms of the dimensions m l and t on the one hand and in terms of
current and voltage on the other hand it follows that quantity of
electricity may be regarded as having the dimensions l  using this
result all the other electrical magnitudes can be expressed in terms
of m l and t with integral indices  the separate question of the
best system of units is discussed briefly the mks system fits well
with the above dimensional system
   /
6652
some post war developments in magnetism  presidential address to
the physical society may the extension of knowledge of the ferromagnetic
domain through the work of neel and others and the systematic use
of the bitter powder figure techniques is surveyed and the main resonance
phenomena and experiments on the diffraction of neutrons by antiferromagnetic
crystals are described
   /
6653
diffraction of electromagnetic waves by a half plane  the observed
intensity and phase values of the field near the edge of a thin high
conductivity sheet are compared with sommerfelds rigorous solution
for an infinitely thin perfectly conducting half plane good agreement
being obtained results for sheets of different thicknesses and conductivities
show the importance of these factors in determining the field
near the diffracting edge
   /
6654
experimental demonstration in the laboratory of the existence of
magneto hydrodynamic waves in ionized helium
   /
6655
reciprocity of the transmissive properties of any multiple layer
for electromagnetic waves  a full analytical proof is given that
the transmission of a perpendicularly incident plane em wave through
a multiple layer consisting of any number of plane parallel absorbing
or nonabsorbing components is the same in both directions if the
first and last media have the same absorption index ie if if and
are different the ratio of the transmission factors in the two directions
is  treatment is simplified by applying quadripole theory but this
does not give a closed expression for the overall transmission factor
the validity of the kirchhoff inversion principle is illustrated
   /
6656
line breadths of the microwave spectrum of oxygen  the microwave
absorption band for consists mainly of lines around the wavelength
mm with spacings of only a few hundred  the intensity of the band
depends on the variation of line widths with pressure this variation
is expressed in terms of the line breadth parameter defined as the
half width measured at half intensity of an absorption line at a
pressure of atm  determinations of this parameter made with a zeeman
modulation spectrograph are reported and discussed and an interpretation
of the self broadening collision process is developed  measurements
are also reported for broadening due to collisions with foreign molecules
   /
6657
radio astronomy  a general review of the subject with a description
of methods of measurement and discussion of the theory of galactic
and solar rf radiation
   /
6658
solar outbursts at mm wavelength  report of results obtained at the
naval research laboratory washington dc with an aerial having an
aperture of and correlation with observations at wavelength and with
the occurrence of solar flares  typical records are reproduced  the
mm bursts are in general of smaller amplitude and of much shorter
duration than the bursts observed on greater wavelengths
   /
6659
radio observations of the solar eclipses of september and february
preliminary report of results which were confirmed during the february
eclipse by observation at marcoussis near paris and at dakar french
west africa  see also of may
   /
6660
radio frequency radiation from tycho brahes supernova  observations
at a frequency of revealed a radio source whose coordinates agree
closely with those of the supernova of  data for the supernovae of
ad and are compared
   /
6661
line emission from interstellar material in the radio frequency range
historical review of published results including particular reference
to the hydrogen emission line at
   /
6662
on the possible relation of galactic radio noise to cosmic rays
the possibility is considered that cosmic rays are accelerated in
regions of the galaxy with intermediate particle density cm  a conservative
estimate of the magnetic fields in such regions would lead to
a radio noise flux of the observed order of magnitude the observed
spectrum could easily be produced
   /
6663
occultation of a radio star by the solar corona  interferometers
of high resolving power were used to reduce the amplitude of the
record from the undisturbed sunduring observations of the radio star
in taurus as it passed near the suns southern limb  a decrease of
amplitude occurred on both and when the angular separation of star
and sun was as great as ten times the angular radius of the visible
disk the amplitude decreases being greatest when the angular separation
approached its minimum value  the results will be discussed in a
later paper
   /
6664
on the dielectric constant of the water in wet clay  an explanation
is put forward of the variation with moisture content of the permittivity
of soil samples previously observed by cownie and palmer of  it
is suggested that relatively dry clay consists of closely packed
water coated particles in an air matrix while relatively wet clay
consists of particles uniformly distributed in a water increasing
from the value for bound water about to that for free water about
as the percentage of water is increased
   /
6665
maxwells equations for three layered media and their application
to the theory of the movement of a magnetic storm  solutions of the
characteristic equations for ideal and for real three layered media
are given  application is made to discussion of the characteristics
of the marginal layers and calculation of the velocity of propagation
of the elements of a magnetic storm  other possible applications
of the theory given are noted
   /
6666
ionospheric disturbance of february  a short account of observed
variations of night sky brightness f layer limiting frequency radiocommunication
with north america and radiosonde measurements of air temperature
a solar origin for the disturbance cannot be assigned with
certainty
   /
6667
a self consistent calculation of the dissociation of oxygen in the
upper atmosphere  a model is considered similar to that previously
proposed of but with the requirement of radiative energy balance
abandoned and with a particular temperature distribution assumed
calculations indicate a much narrower dissociation region occurring
at a lower altitude
   /
6668
the bbc ionospheric storm warning system  the various data on which
the bbc warning system is based are noted and a statistical review
is presented of the correlation between actual and forecast ionospheric
conditions in the period  the accuracy of the forecasts during this
period was of the order of
   /
6669
correlation between the mean level of atmospherics and the degree
of intelligibility in a kilometre wave radio link  measurements made
on june at the laboratoire national de radio electricite using a
wavelength of are reported  the signalling speed was words min and
the signal strength at the receiver  a vertical aerial was used and
atmospherics were received simultaneously with the signal  the numbers
of wrong or indecipherable figures and letters received are indicated
on a graph of mean field strength of atmospherics plotted against
hour of day  good correlation is observed
   /
6670
the stability of a multiple linear servo system
   /
6671
recent developments in vibrators and vibrator power packs  discussion
of the grade type of vibrator which is expected to give at least
the hour life required for services equipment  reasons are given
for specializing mainly on synchronous split reed separately driven
types  an outline is given of extensive investigations of contact
phenomena vibrator design and the circuits fed by the vibrator  a
range of vibrators is described with outputs from a few milliwatts
to over  very high conversion efficiencies have been obtained
   /
6672
titanium dioxide rectifiers  a detailed account of work carried out
up to the present on the to film rectifiers previously noted of
a feature of great practical importance is the improvement in performance
with increase of temperature  for a particular steam treated sample
the forward current increased while the backward current decreased
slightly as the temperature was increased up to  heating to however
causes irreversible damage  differences of characteristics observed
with different counter electrode metals are discussed a marked change
of properties being noted when zn was used  further investigations
are in progress
   /
6673
voltage regulators using nonlinear elements  a simple method of determining
the parameters of circuits providing reference voltages working
o into a constant load is described and is illustrated by calculations
for arrangements using either a single element or a pair of the nonlinear
resistors manufactured by the compagnie generale de tsf of  power
limitations restrict the field of application of this type of voltage
regulator
   /
6674
how to design vr tube circuits  families of supply voltage supply
series resistance curves for various voltage regulator tubes are
used as the basis for designing stabilized direct voltage supply
circuits
   /
6675
theory of the prediction and filtering of stationary time series
according to norbert wiener  digest of wieners book the extrapolation
interpolation and smoothing of stationary time series with engineering
applications of
   /
6676
equipment for amplification of weak photoelectric currents  description
with detailed circuit diagram of equipment using a double electrometer
valve mazda type the currents in which are modulated by a square
wave applied to the extraction grids the photoelectric voltage being
applied to the control grids
   /
6677
changing the phase of a low frequency sinusoid  description of various
methods suitable for manual or automatic control or combined automatic
and manual control of the phase of a sinusoidal low frequency voltage
   /
6678
modified magic tee phase shifter for microwaves  the modified unit
described has the symmetrical arms parallel to each other thus allowing
both short circuiting plungers to be linked to a common drive  the
e and h plane arms are replaced by odd and even coupling slots  owing
to the existence of several sources of impedance mismatch in the
complete phase shifter which uses a second magic t junction a special
alignment procedure is necessary
   /
6679
basic operating principles of magnetic amplifiers
   /
6680
low input power level magnetic amplifiers
   /
6681
rules of similitude for magnetic amplifier systems  rules are established
which enable the properties of magnetic amplifier systems to be
deduced from the results of suitable tests on a model the amplifier
or analogue computer  the method covers cases in which model and
prototype have different core materials and different circuits
   /
6682
the application of a cycle magnetic amplifier to a position indicating
servomechanism
   /
6683
a magnetic amplifier of high input impedance
   /
6684
use of the flux charge concept in magnetic amplifier analysis
   /
6685
a series magnetic amplifier with inductive loading  analysis and
discussion of the manner in which the current waveform is affected
by varying the circuit resistances inductances or control voltage
digest only full paper to be published in trans amer inst elect engrs
   /
6686
a synchronizing circuit for variable input voltages  description
of a circuit suitable for use with a cro
   /
6687
boroncarbon resistor characteristics  further developments are described
leading to the mass production of resistors with extremely stable
characteristics  see also and of grisdale et al
   /
6688
shaping of nonlinear resistor characteristics  feedback circuits
are described which enable a wide variety of characteristics to be
obtained with a single resistive element
   /
6689
effect of pressure on the resistance of a thermistor  measurements
at constant temperatures from and pressures up to show that the relative
diminution of the resistance of a thermistor for a given change of
pressure is practically independent of temperature and is given by
the formula p being expressed in kg cm
   /
6690
all triode electronic switch  the basis of the arrangement described
is a gate circuit using two high triodes cathode coupled respectively
to two high transconductance triodes the grids of the latter being
coupled to the anodes of a multivibrator
   /
6691
metallized paper capacitors  review of the development construction
and characteristics of this type of capacitor particularly those
using impregnated paper  test methods are noted
   /
6692
high temperature operation of metallized paper capacitors  discussion
of results obtained with capacitors impregnated with aerolene a solid
polyester which permits operation at without derating and up to with
a derating of the capacitance value at being higher than at room
temperature
   /
6693
an electronic square law circuit for use with a graphic recorder
the curvature of valve characteristics is used to produce an output
voltage proportional to the square of the input voltage  circuit
details are given of a mean square value meter suitable for graphic
recording of the output
   /
6694
performance of ultrasonic vitreous silica delay lines
   /
6695
the synthesis of a network to have a sine squared impulse response
the method of moments of the mean moment type used by moss is applied
to the problem of designing a network with an impulse response of
prescribed form  the method is not applicable in all cases but is
particularly suitable for the design of a low pass system with not
too sharp a cut off and not too oscillatory an impulse response
calculation for the case of the sine squared pulse results in design
data for a ladder network of inductors and capacitors with resistive
terminations  the discrepancy between the impulse response curve
and the exact sine square curve at no point exceeds of the peak amplitude
of the pulse
   /
6696
new graphical methods for analysis and design  reply to comment by
schneider of on paper noted in of saraga and fosgate
   /
6697
the transient response of rf and if filters to a wave packet  summary
only  analysis based on fourier integral transforms is applied to
two particular circuits a single stage of tuned anode coupling a
single stage of tuned transformer coupling  the analysis is valid
for circuits of any bandwidth  particular attention is paid to the
build up time of a transient which for a band pass network is usually
assumed to be inversely proportional to the network bandwidth  the
analysis shows that this assumption is correct for the tuned anode
coupling circuit if the ratio of the half bandwidth to the resonance
frequency is less than unity  for the tuned transformer circuit however
the rule does not hold good since for a given bandwidth there are
many possible transfer impedances and hence transient responses
the rule should therefore only be applied to circuits which its application
is shown to be legitimate
   /
6698
high q low frequency resonant filters  two resonant filters are described
in which a q factor is obtained by application of positive feedback
normal methods used for q measurement are of little use on these
circuits  a method based on the relation of q to the transient response
is described
   /
6699
printed unit assemblies for tv  etching and silk screening techniques
and their suitability for the production of various circuit elements
are discussed  experimental results are quoted which show that the
performance of etched coils compares favourably with that of wire
wound coils
   /
6700
etched circuits  a brief note on the technograph system for producing
printed circuits and components with special reference to the production
of mains transformers
   /
6701
printed circuits for home radio receivers  units for valve superheterodyne
sets are produced by pl ting conductors on to a plastic base
in which holes have been punched previously  the walls of the holes
are plated at the same time thus providing connections and terminal
points
   /
6702
new developments in the auto sembly technique of circuit fabrication
various applications of the technique previously described of danko
and lanzalotti are reviewed  new copper faced plastics are suitable
for production of equipment for operating temperatures up to  use
of a solder resistant paint or lacquer enables joints only to be
soldered in the soler dip process  typical examples of circuits and
assemblies produced by this method are illustrated
   /
6703
graphical analysis for circuits containing overdriven vacuum tubes
methods of approach and graphical constructions for use in analysis
of circuits such as those used for pulse forming and wave shaping
are described with applications to particular circuits
   /
6704
thickness vibrations of piezoelectric crystal plates  continuation
of investigation noted in of  the retroaction occurring in piezoelectric
processes modifies not only the modulus of elasticity but also the
direction of motion  the influence of this secondary effect is studied
and a complete theory of the mechanical electrical oscillating system
is developed for plates of infinite area  for plates of finite area
the amplitude distribution becomes nonuniform the effect of this
modification is studied in relation to the equivalent circuit
   /
6705
a method of analysis of fundamental and overtone crystal oscillator
circuits  use of the method of loci facilitates comparison between
the pierce miller and the pierce colpitts type of crystal oscillator
circuit  type is much more suitable for harmonic oscillation and
very high frequencies because it requires less mutual conductance
type is under certain conditions particularly suitable for frequency
standards  circuits with the crystal connected between anode and
cathode have under certain conditions low power dissipation in the
crystal  conditions for frequency stability are analysed and a simple
and accurate method of determining crystal parameters is described
   /
6706
broad band coupling unit for power line carrier with associated potential
device
   /
6707
some perturbation effects in microwave cavities operating in degenerate
modes  theoretical investigation of the perturbation caused by introducing
a metal rod into a cylindrical cavity operating in the companion
modes te and tm  the changes in q value and resonance frequency are
different for the two modes  the magnitudes of these changes as dependent
on the radius and depth of insertion of the rod are considered
   /
6708
precalculation of the mains loading in the design of high frequency
generators using quenched sparks  the power required to drive a hf
generator of the air blast quenched spark type is determined from
consideration of the generator equivalent circuit  such generator
are frequently used for hf inductive heating
   /
6709
the effect of noise on the frequency stability of a linear oscillator
the standard conditions for a sinusoidal oscillation are that the
attenuation and net phase shift around the closed loop be zero  random
fluctuations are relied upon to start the oscillation  if the level
of oscillation is to remain finite in the continued presence of noise
the oscillating loop must hav  some attenuation and functions like
a highly regenerative amplifier with a loop gain very nearly unity
accordingly the oscillator produces not a single frequency but rather
a narrow band of noise that causes instability in the magnitude and
in the apparent frequency of the output  thes instabilities are discussed
for oscillators in which all elements are linear except for some
slow acting amplitude control  the bandwidth of the noisy oscillation
can be predicted from easily measured system characteristics  several
methods of defining the frequency of the output are considered with
special reference to precision measurements  in general the measured
frequency departs from the zero phase shift criterion and is dependent
on the measuring equipment  methods of minimizing instabilities due
to noise are investigated
   /
6710
the effect of long transmission lines on klystron oscillators  discussion
of effects occurring when the oscillator load is several wavelengths
away from the valve  equivalent circuits are applied to analysis
of the fm distortion and of the discontinuities in the klystron characteristics
experimental results are presented which corroborate the
theory
   /
6711
a hard valve pulse generator  description with circuit details of
a triggered generator producing pulses of width variable from to
slight modifications result in a free running generator a triggered
generator of pulses which is easily converted to free running with
a repetition period od of ms  pulses of either polarity can be used
for triggering
   /
6712
a design for a constant volume amplifier  the so called constant
volume amplifier is used extensively on overseas telephone circuits
so that a reasonable modulation depth can be used without the risk
of overmodulation  circuit details are given of an amplifier which
is simple to set up and reliable in operation and which uses a cathode
follower circuit as a variable impedance  the results obtained are
comparable to those given by conventional networks using metal rectifier
bridge networks
   /
6713
a feedback pair video amplifier  details are given of a circuit with
a gain of frequency range and a midband output linear up to rms
   /
6714
cathode follower as high impedance input stage  if a cathode follower
is used as the first stage of an amplifier in order to raise the
input impedance the conductance of the grid leak between grid and
cathode may not be negligible compared with the conductance of the
source between grid and earth from which the signal is derived  the
noise performance under these conditions is examined both in terms
of the cathode follower regarded as a voltage device and in terms
of the noise figure which takes account of the difference between
input and output impedances
   /
6715
amplifier noise particularly in the audio frequency range  noise
in input stages is investigated nyquists formula is taken as starting
point and only simple mathematics is used  noise in resistors is
dealt with by the usual device of substituting an equivalent noise
voltage source in series with a noise free resistor  the input circuit
of a capacitor microphone is considered particularly its noise voltage
is determined largely by the slope and position of the low frequency
flank of the response curve  noise in oscillating circuits is associated
with the damping resistance  formulae are given for calculating the
equivalent noise resistance of valves for the same operating point
a valve produces much more noise in the af range than at higher frequencies
the signal noise ratio of a circuit with ideal input transformer
is considered and the condition for obtaining maximum sensitivity
is derived
   /
6716
dc amplifiers with low pass feedback  brockelsby of and mayr of have
shown how to design a voltage amplifier of high stability and with
a response curve of maximum flatness but their method has the disadvantage
that the amplifier must have a particular value of loop gain
if the loop gain is varied the overall frequency response will be
seriously affected and the amplifier may be unstable if used as an
integrator or differentiator  the method is extended to cover the
case of a dc amplifier with a low pass feedback network the gain
of such an amplifier can be varied over a wide range without appreciable
effect on the overall frequency response so that it can be used as
a stable differentiator or integrator  the output noise level may
limit the field of application
   /
6717
representation of experimental results by equations  an analytical
method is discussed for determining the form of the equation representing
the measurements of a dependent variable as a function of an independent
variable the accuracy with which values can hence be found for
the numerical coefficients is examined
   /
6718
representation of experimental results by equations  new useful formulae
methods are outlined for determining the coefficients of equations
fitting a series of observed values weighted or not weighted
   /
6719
transfer and transport of energy by resonance processes in luminescent
solids  experiment shows that the ratio between the efficiencies
of activator and sensitizer fluorescence increases with increasing
sensitizer concentration  this is at variance with theory  an explanation
is given and a theory is developed that accounts for the temperature
dependence of the energy transfer
   /
6720
the uniqueness of the solutions in the rigorous theory of diffraction
the solutions previously given by honl of not only satisfy the usual
conditions but also meet the requirement that no subsidiary wave
fields be radiated from the edges of the aperture so that the uniqueness
of the solutions is established
   /
6721
a simplifying technique in the solution of a class of diffraction
problems  considerable simplification of the treatment of diffraction
problems leading to wiener hopf integral equations results from taking
the transform before applying the boundary conditions  this is demonstrated
by consideration of the sommerfeld problem for the semi infinite
plane the diffraction of small amplitude sound waves by a semi infinite
rigid cylinder the diffraction of a plane em wave by a finite waveguide
a vector field
   /
6722
new direct vision stereo projection screen  russian work on stereo
projection screens is briefly described and a more detailed account
is given of a system developed in france by f savoye see rev photographic
optique  this uses a rotating cone shaped grill moving round the
screen thus enabling collective direct vision of stereoscopic pairs
in either monochrome or colour
   /
6723
motion of gaseous ions in a strong electric field part  the theory
previously given for uniform ion densities of is extended to deal
with nonuniform densities  errata in the earlier paper are indicated
   /
6724
mechanism of resistance variation in a magnetic field  a model with
two layers having different resistances and resistivities is proposed
to explain the hall effect and the variation of resistance of a material
subjected to an electric field
   /
6725
theory of the electrical conductivity of metals in a magnetic field
formulae are derived for determining the resistance of metals in
a transverse and in a longitudinal magnetic field taking into account
the quantization of the movement of electrons in a magnetic field
   /
6726
theory of the contact between a metal and a semiconductor for a large
contact potential difference  the iv characteristic for the contact
between a metal and a semiconductor is calculated for the case when
the contact potential difference is so great that the type of conduction
of the semiconductor near the contact is altered from the electron
to the hole type  the calculations cover the cases of plane knife
edge and needle types of contact
   /
6727
determination of electron density and collision frequency in a gaseous
discharge by microwave propagation measurements  the gaseous discharge
to be measured fills a section of waveguide several wavelengths long
and measurements are made of the absorption and phase shift of a
low power microwave signal passing through the discharge  results
are quoted for ar at pressures respectively of and mm hg
   /
6728
reliability of probe measurements in hot cathode gas diodes  erroneous
results may be obtained due to the work function of the probe altering
during the measurements  particularly when investigating tubes with
oxide cathodes the measurement must be made immediately after cleaning
the r probe  in the experiments described a cro plotter was used
which took ov only some seconds to record the whole probe characteristic
in contrast to results obtained by other workers no deviation
from the maxwellian velocity distribution of the plasma electrons
was observed over a range of nearly four orders of magnitude of probe
current
   /
6729
theory of the propagation of waves in an electron beam  an approximate
theory is developed for the propagation of em waves in a waveguide
filled with a dielectric when an electron beam passes through it
it is assumed that electrons can move freely along the waveguide
in the dielectric and that they form a beam completely filling it
with certain assumptions the types and characteristics of the waves
which can travel in such a system are determined for various conditions
the results obtained can be generalized so as to cover the case of
an arbitrary transmission line
   /
6730
the motion of electrons in the field of a uniformly wound toroid
the focusing properties of the toroid are investigated theoretically
in relation to beta particle or other spectroscopes
   /
6731
secondary electron emission from certain metals under the impact
of positive lithium ions  an arrangement for measuring the emission
is described and results are given for some metals used in electron
microscopy
   /
6732
the relation between electrical and diffusion currents  a linear
relation is derived between the electric current through a conducting
gas in a magnetic field and the currents due to diffusion of the
charge carriers in the gas  from this relation the vertical displacements
of the ionosphere e layer due to lunar effects are determined
from the current system inferred from the lunar changes of the geomagnetic
field  both the amplitude and phase of the displacement are consistent
with observations if it is assumed that the main lunar current
flows in the lower part of the e layer and that approximately equal
numbers of ions and electrons are present at the point of observation
   /
6733
theory of the plasma in a rarefied gas when the current strength
varies  general equations for relatively slow processes in a plasma
are applied to the calculation of the concentration of electrons
and ions when the strength of the current through the gas varies
the partial de ionization of the gas when the current decreases and
the residual concentration of electrons and ions after the current
ceases to flow are determined
   /
6734
calculation of the leakage flux of the pendent armature relay  the
magnetic conductivity of the space between core and yoke is determined
by application of southwells relaxation method
   /
6735
investigation of electromagnetic waves guided by helical conductors
full theoretical analysis of the propagation of em waves along helical
conductors  shorter versions of parts of the paper hve previously
been abstracted  the continuous cylinder approximation and of gives
a solution in good agreement with experimental results at frequencies
sufficiently low and with the action of a narrow beam travelling
wave valve  the second method of analysis of based on the infinitely
thin wire concept leads to difficulties in calculation but has more
general application and is apparently correct to the second order
of approximation  its application to delay lines is illustrated
results obtained by the two methods are compared of and discussed
with reference to experimental measurements
   /
6736
reflection of microwaves from metal plate media  experiments were
made using frequencies in the cm band to verify the theory worked
out by lengyel of  waveguide assemblies of various depths were used
with the reflecting surfaces normal to the plates  for single surface
measurements the absorbing wedges described by ruze and young of
were used  phase and amplitude of the reflection coefficient were
determined for angles of incidence and for various ratios between
plate separation and wavelength  double surface slab measurements
were also made using assemblies of parallel plates instead of square
waveguides
   /
6737
the propagation of the wave front in a dispersive medium  the problem
is investigated theoretically by means of the laplace transformation
for the general case of a plane em wave in a homogeneous medium
   /
6738
a soluble problem in energy bands  the problem of an electron moving
in a periodic simple cubic potential of the form cos x cos y cos
z in investigated with particular attention to the nature of the
wave functions  wannier functions degeneracy of overlapping bands
etc
   /
6739
kodaikanal observatory  an indication is given of the scope of the
work carried on at this solar physics observatory and of results
so far achieved  magnetic meteorological and si seismological observations
are made and the imminent commencement of ionosphere soundings
is reported
   /
6740
double doppler study of meteoric echoes  both the amplitude and phase
of the signal returned from a meteor trail can be determined independently
by use of a twin channel doppler system details of which are
presented  the technique has direct application to the determination
of the drift of meteor trails and to analysis of the spectra of echoes
which exhibit amplitude fading
   /
6741
final relative sunspot numbers for
   /
6742
provisional sunspot numbers for april to june
   /
6743
scintillation of radio stars during aurorae and magnetic storms
during aurorae the rate of scintillation is four times that during
normal conditions probably as a consequence of a fourfold increase
in the drift speed of the ionosphere irregularities causing the scintillations
more generally the scintillation rate and the speed of the
ionosphere irregularities are approximately proportional to the k
index of geomagnetic activity
   /
6744
cheltenham three hour range indices k for april to june
   /
6745
indices of geomagnetic activity of the observatories abinger eskdalemuir
and lerwick july and august
   /
6746
secular variation of the magnetic field at colaba and alibag
   /
6747
principal magnetic storms
   /
6748
international data on magnetic disturbances first quarter
   /
6749
nitrogen in the upper atmosphere  the probable distribution of atomic
n is investigated theoretically the method of calculation adopted
is a modification of that used by penndorf in investigating the dissociation
of oxygen of  within the height range km the predissociation
mechanism suggested by herzberg and herzberg operates while in the
range a dissociative recombination suggested by mitra is effective
in the lower region there is a sharp maximum in the distribution
curve at about km in the upper region the concentration increases
monotonically with height  the total number of n atoms in a vertical
column of cross section is calculated to be about
   /
6750
physical properties of the upper atmosphere over india  the height
temperature curve for central india from ground up to km has been
constructed using data obtained from balloon measurements and sound
propagation experiments  the isothermal region found in the lower
stratosphere over middle latitudes does not exist over india the
temperature increasing steadily above the tropopause  a comparison
of data for india and for europe indicates that summer east winds
over north india extend up to about km with strong westerly winds
aloft
   /
6751
dynamic phenomena in the ionosphere  records of f layer height obtained
with the rapid sweep sounder at freiburg show trace detail indicative
of transient ionospheric variations  various types of deformation
of the trace are noted  these short lived disturbances are nearly
always propagated from a high level downwards
   /
6752
an effect of the moon on the median height of the ionosphere f layer
at huancayo on the magnetic equator there is a lunar effect amounting
to several per cent on the median height of the f layer during local
summer the effect is very much smaller in winter  at freiburg in
a moderate latitude the effect is extremely small if it exists at
all
   /
6753
the solar control of the e and f layers at high latitudes  the monthly
mean critical frequencies of the e and f layers at high latitudes
vary diurnally with solar zenith angle according to a modified chapman
law  measurements of the seasonal latitude and solar cycle phase
dependence of the e layer sensitivity to solar zenith angle and subsolar
frequency are shown graphically  in the auroral zone e layer sensitivity
to solar zenith angle is very low but to the north of the zone it
has the chapman theoretical value
   /
6754
ionospheric refraction of radio waves from radio stars  an estimate
of the total ionization of the f layer can be deduced from the refraction
of radiation from radio stars caused by horizontal gradients of
ionization occurring during normal diurnal variations in the layer
interferometer measurements of the apparent positions of four radio
stars are reported and the results are compared with calculated values
based on ionospheric soundings agreement is found if certain plausible
assumptions are made regarding the vertical distribution of electrons
about the maximum concentration level of the f layer
   /
6755
the relation between electrical and diffusion currents
   /
6756
a procedure for the determination of the vertical distribution of
the electron density in the ionosphere  description of a method based
on application of the gauss christoffel quadrature formula to the
numerical integration of the well known integral for true reflection
height s as a function of group height  the earths magnetic field
and the effects of electron collisions are neglected ray theory is
assumed applicable and the electron density height curve is assumed
to have no maxima or minima in the region considered
   /
6757
a method for obtaining the wave solutions of ionospherically reflected
long waves including all variables and their height variation
   /
6758
design of damper stabilized instrument servo mechanisms
   /
6759
a transient approach to the solution of a linear servomechanism by
an equivalent network
   /
6760
stabilization of variable carrier frequency servo mechanisms
   /
6761
highly stable power supply  description of equipment giving voltages
adjustable between and with loads up to the variation of output voltage
is of the order of part in for line fluctuations of  the dc output
resistance is and the residual hum voltage  a valve is used as voltage
comparison standard  the feedback circuit includes two pentode stages
and a cathode follower stage comprising two triodes in parallel
   /
6762
high voltage power supplies  two units are described an interrupted
rf oscillator with rectifier tripler and a continuous rf oscillator
with rectifier doubler  both give an output of about at at and both
include low loss transformers with ferroxcube cores  is housed in
an oil filled container is larger and dispenses with oil
   /
6763
a variable voltage stabilizer employing a cold cathode triode  a
circuit is described in which a cold cathode gas filled triode acts
as a dc amplifier  such an arrangement has desirable characteristics
as a voltage stabilizer in low current circuits  a portion of the
output voltage of a source is compared with a reference voltage the
difference being used to control the current through the parallel
connected stabilizer valve so that the output voltage is maintained
at a constant value
   /
6764
ohms law for build up phenomena  in the case of pole networks the
laplace transformation is applied in the form of a fourier integral
of the input waveform  doetschs symbolic notation for asymmetrical
transformations of is used and the equality sign of ohms law is replaced
by the doetsch transformation sign  the variation with time of a
current through a complex impedance is given by the laplace transform
product of the susceptance and the applied voltage spectrum  application
of the transformation in quadripole theory is described  by formulating
the quadripole equation in chain matrix form transient response parameters
can be roughly estimated  application of the theory to the determination
of transient distortion in communication systems and to the
stability testing of amplifiers is outlined
   /
6765
pulse amplitude analysis in nuclear research  various voltage discrimination
techniques are discussed in detail and descriptions are given
of a simple type of analyser and a moderate precision and a high
precision analyser  analysers are also discussed in which pulse height
selection is effected either by mechanical means or by use of diode
valves trigger circuits sorting ladder circuits or beam deflection
techniques  other types of analyser described include those in which
height selection is accomplished by an expander amplifier driving
a chain of discriminators by conversion of pulse amplitude to pulse
duration by means of information storage devices  references
   /
6766
low cost variable phase shifter  the basis of the circuit is a linear
resistance potentiometer divided by tappings into four equal sections
neighbouring sections being fed by a pair of transformer secondaries
with voltages phase separated by  the value of the potentiometer
resistance is not critical providing it is large compared with the
impedance of the transformer secondaries
   /
6767
dynamics of transistor negative resistance circuits  a general method
is presented for calculating approximately the characteristics of
nonlinear circuits  the region of operation is divided into subregions
within each of which the circuit may be considered as nearly linear
the method is applied to analysis of a high speed switching circuit
using a point contact transistor discussion of negative resistance
relaxation oscillations calculation of waveforms and rise times of
a regenerative transistor amplifier below
   /
6768
matrix representation of transistor circuits  transistor circuits
are discussed in terms of measurable quantities only  once the admittance
matrix of the grounded base transistor has been determined the
matrices of the grounded emitter and grounded collector transistors
can easily be derived  matrix representation also provides a direct
method for analysis of stages in cascade
   /
6769
transistor noise in circuit applications  problems of linear circuits
involving multiple noise sources can be handled by familiar methods
with the aid of certain noise spectrum functions which are described
several theorems of general interest in circuit work dealing with
noise spectra and noise correlation are derived  the noise characteristics
of transistors can be described in terms of the spectrum functions
for simple but arbitrary configurations of equivalent noise generators
from these the noise figure can be calculated for any external circuit
numerical results for a number of npn transistors are given in a
table and many curves
   /
6770
junction transistor equivalent circuits and vacuum tube analogy  a
comparison is made between the operating characteristics of a pnp
junction transistor and a triode valve using a network to represent
the transistor
   /
6771
nonlinear circuit elements in high frequency and low frequency technology
a review of the properties and applications of nonlinear inductors
capacitors and resistors of many different types see also of
   /
6772
new commercial barretters  the characteristics of two tungsten coil
barretters are given  the resistances when cold are respectively
and a current of about doubles the resistance in each case  tests
to determine the cooling characteristics and the effect of ambient
temperature changes are described
   /
6773
coil winding data  charts give the number of turns required in conjunction
with various values of capacitance for tuning over the frequency
ranges and using standard formers with dust cores
   /
6774
new bistable high speed multi purpose device  operating conditions
for an eccles jordan circuit using two type triode hexode valves
are noted  with suitable diode limiting consistent operation is maintained
at pulse rates sec
   /
6775
arithmetical counters for pulses  a list is given of relevant publications
with short notes indicating their scope
   /
6776
a transistor reversible binary counter  the counter is built of elementary
transistor packaged units  the mechanism used to achieve reversibility
and the circuit for each type of building block are described
   /
6777
transistor trigger circuits  analysis is presented for transistor
trigger circuits which permits prediction as to whether operation
will be monostable bistable or astable oscillatory and also of the
amplitude and waveform of the output  practical pulse circuits for
various purposes are described which are so designed that their operation
is not affected by reasonable variations of circuit parameters
bias voltages transistor characteristics or ambient temperature
   /
6778
transistors in switching circuits  analysis of transistor trigger
circuits is based on an approximate representation of the negative
resistance characteristic by three straight lines  circuits using
point contact transistors for waveform generation level restoration
delay storage and counting are described and their properties n and
limitations are discussed in detail
   /
6779
graphical analysis of some transistor switching circuits  methods
are described for generating the entire input characteristics for
the various terminals of a transistor and graphical methods of analysis
are applied to a base input amplifier a collector to emitter direct
coupled switching circuit a collector to base direct coupled circuit
   /
6780
electronic switch  a switching circuit for two waveform display with
a single beam cro uses a conventional multivibrator for generating
the switching voltages
   /
6781
network analysis by repeated voltage superposition  a method of analysis
is described with worked out examples which reduces considerably
the number of simultaneous equations to be solved for an m mesh network
the method essentially involves successive applications of thevenins
theorem each application reducing by one the number of meshes in
the network considered with a corresponding reduction of the number
of simultaneous equations to be solved  a similar method has been
described by tasny tschiassny of who used residual current generators
at the final nodes instead of residual voltage generators in the
final branches and whose method differs from the present method in
other details
   /
6782
synthesis of cascaded three terminal rc networks with minimum phase
transfer functions  for the realization of a particular transfer
function including complex zeros the method of synthesis presented
yields a network with fewer elements simpler configurations and higher
level of transmission than previous methods eg of
   /
6783
the practical significance of complex frequencies in electrical communication
engineering  a concise general introduction to the subject
complex frequencies are complex quantities whose real part represents
the gain of a system and whose imaginary part represents the frequency
in the usual sense  the application of the laplace transform in analysis
of transmission problems is explained and the properties of the complex
plane and its poles and zeros are described  the use of the poles
and zeros for representation of the transmission characteristics
of a linear network iis considered  analogues of the complex plane
such as that obtainable with a stretched elastic membrane are discussed
and their applications illustrated
   /
6784
anode follower derivatives  low output impedance stages characterized
by anode output and feedback of the entire output voltage are derived
from the basic anode follower by substitution of a vlve impedance
for the shunt resistor of the feedback path or of a comparator stage
for the entire input feedback potential divider and by replacement
of the output valve by a series connected push pull pair  these developments
suggest the possibility of obtaining an anode follower analogue
of each cathode follower derivative thereby increasing the number
of circuit variants available for practical use
   /
6785
applications of tensor theory to linear electronic circuits  an explanation
of tensor concepts and their general application to valve circuits
with examples illustrating the determination of input impedance and
gain of feedback cathode follower and grounded grid circuits
   /
6786
on the approximation problem in network synthesis  a method of synthesis
is presented in which a desired frequency response characteristic
is replaced by an approximation consisting of a sequence of rectilinear
segments  the method is illustrated by application to the design
of attenuation equalizers with constant resistance ladder sections
   /
6787
the parallel t resistance capacitance network  analysis is given
for the general case of finite source and load resistances  when
these two resistances are appropriately related the network loss
is the same at low and high frequencies the transfer characteristic
is then a circle in the complex plane  this symmetrical networks
is equivalent to a simple series resonant circuit as regards its
transfer characteristic
   /
6788
rc cathode follower feedback circuits  when certain rc circuits are
associated with a cathode follower circuit a voltage gain can be
obtained over a band of frequencies  a number of prototype and derived
rc circuits which can be used in this way are analysed and their
response curves are determined  the matrices of the derived networks
can be formed easily from those of the corresponding prototypes
the effect of circuit termination on response is discussed and the
use of these circuits as feedback elements in amplifiers is considered
in some detail  experiments in confirmation of the theory are mentioned
   /
6789
resistance capacitance networks with over unity gain  longmire of
and epstein of have described rc circuits with greater output than
input voltage  a method of increasing the voltage gain by feeding
the output voltage of one network into a second network is described
the process cannot be extended indefinitely the voltage gain attainable
being limited by the impedance increase necessary at each stage
experiments confirmed the theory  such networks can be used with
a cathode follower to construct oscillators in which the valve gain
is less than unity  an experimental circuit is described
   /
6790
response of a linear network to an input with linearly variable frequency
as obtained in sweep frequency testing  application of an input
voltage with linearly increasing frequency to a linear network produces
an output curve which for very slow frequency variation is an image
of the admittance plotted as a function of frequency  when the rate
of frequency variation is not negligible the response curve is a
distorted image of the admittance  the nature of this distortion
is investigated  a quantitative approximation method is presented
which uses the theory of functions for evaluation of an integral
the result is expressible in terms of elementary functions  explicit
expressions are given for the dynamic corrections to be applied to
the observed resonance frequencies and peak admittances  the method
is applied to several simple circuits in addition to the lcr circuit
which has been previously treated by other authors
   /
6791
fundamentals of filter theory and technique  description of the application
of the wave theory and the operating parameter theory in the
design and calculation of different basic types of filter
   /
6792
formulae for ladder filters  four related sets of explicit formulae
for the elements of a basic low pass filter network are presented
with a common notation  three of the sets have been published previously
of norton of of belevitch the fourth being new all have reference
to the image parameter theory due to norton and darlington of  if
corresponding formulae could be found for a general type of filter
with response depending on jacobian sn elliptic functions they would
represent a considerable contribution to filter design technique
   /
6793
a nonlinear statistical filter  a method is described for using the
statistical differences between a periodic rectangular pulse the
wanted signal and the envelope of fluctuation noise the interfering
signal for the purpose of discriminating between the two signals
expressions are derived for the density distribution probability
of noise and of signal plus noise  a description is given of a practical
filter which was checked experimentally under conditions when the
signal was completely masked by the noise both aurally and visually
but could be reliably detected by means of the statistical filter
possible application to secret transmission systems is discussed
   /
6794
numerical calculation of filter circuits with tchebycheff characteristics
after the method of w cauer  formulae for tchebycheff type filters
are derived from those previously given for filters with generalized
parameters of  three types of antimetrical filter are considered
the formulae necessary for numerical calculation of both symmetrical
and antimetrical normalized filters are derived and applied to examples
by suitable frequency transformation the normal type of tchebycheff
filter can be dealt with  a complete set of curves is provided for
evaluation of the required parameters
   /
6795
coaxial transmission line filters  analysis for coaxial line band
pass filters is given based on tem mode transmission  the influence
of the nature and spacing of the obstacles on the bandwidth is discussed
measurements on filters of various constructions support the theoretical
results  a te mode high pass filter is also discussed  for narrow
band applications this type of filter is inferior to the cavity type
   /
6796
nonlinear filtering and waveshape multiplexing  a method of providing
two channels on one carrier consists of differentiating the combined
signal clipping to remove one component and re integrating to restore
the other  the removed component is recovered by subtracting the
retained component from the original input  experimental circuits
and waveforms obtained are illustrated the two components being respectively
a sine wave and a square wave
   /
6797
functional circuit diagrams  shortened version of paper abstracted
in of january
   /
6798
transistors in airborne equipment  discussion of the advantages of
using transistors instead of valves in aircraft equipment
   /
6799
slow speed circular timebase  french version of paper by hardie and
thomas of supplemented with references and a note on earlier types
of sine cosine potentiometer
   /
6800
printed circuitry for transistors  the auto sembly technique of february
danko is suggested as a simple and effective method for the production
of compact transistor circuits
   /
6801
resonance curves  deviations encountered in practical circuits from
the ideal conditions dealt with in elementary theory are simply explained
   /
6802
spontaneous voltage fluctuations in a resonant circuit  the rms value
of voltage fluctuations of thermal origin at the terminals of a parallel
rlc circuit is determined for the unusual case where the frequency
range in question is not negligible in comparison with the bandwidth
of the resonant circuit  curves are given to facilitate numerical
calculation
   /
6803
a junction transistor tetrode for high frequency use  application
of suitable bias to a fourth electrode connected to the p type central
section of an npn junction transistor causes a considerable reduction
of the base resistance  this reduction enables the transistor to
be used at frequencies over ten times the normal limit  circuits
are given for a variable frequency tuned amplifier a band pass amplifier
and a sine wave oscillator for
   /
6804
transistor oscillators  the characteristics of transistor oscillators
are established by analysis in which the conductance form of the
transistor equations is used  the following circuits are considered
transistor with frequency determining quadripole and overall feedback
as in but with transformer coupling between transistor and quadripole
transistor oscillator with a arrangement of three parallel connected
tuned circuits
   /
6805
low drain transistor audio oscillator  description and performance
of a oscillator using a western electric type point contact transistor
supplied from a single battery the power drain from which does not
exceed
   /
6806
a low frequency function generator  description of a relaxation oscillator
capable of giving a constant amplitude output of sine square
or triangular waveform in the frequency range
   /
6807
automatic tuning control of hf generators with varying load  the
phase relation between the primary voltage and the secondary current
of the output transformer of a crystal driven generator is used for
automatic control of the tuning of the output circuit under varying
load conditions  control is effected via a bridge type of phase measurement
unit using a pair of type eq enneodes which acts on a control
unit using a pair of type pl thyratrons  circuit details photographs
and performance figures are given
   /
6808
pulse duration and repetition rate of a transistor multivibrator
expressions are derived for the pulse duration and repetition rate
of an astable oscillatory multivibrator circuit using a point contact
transistor  the formulae are confirmed experimentally for repetition
rates from to per sec and pulse durations from to
   /
6809
variable inductance and its application in frequency sweep oscillators
the modulation principle described consists in varying the voltage
across an inductor while the current through it is maintained constant
alternations of the control grid voltage of a pentode cause anode
and screen grid currents to vary in magnitude developing a voltage
variation across an anode inductor coupled to the inductor in the
cathode circuit  the current through l is maintained constant by
an alternating voltage applied to the suppressor grid  a frequency
shift of around is attainable  the use of the method for fm and frequency
sweep tuning is indicated
   /
6810
double counter fm and afc discriminator  a frequency discriminator
with large bandwidth and good stability comprises a pair of pulse
counter circuits each preceded by mixer and pulse forming circuits
with their outputs connected in series
   /
6811
vacuum tube circuits without plate supplies  the existence of thermal
emf and contact potential makes circuit operation possible with out
application of voltage to valve anodes  a limiter a low gain amplifier
a multivibrator and an oscillator circuit are described
   /
6812
volume compression and expansion  comment on of february and authors
reply
   /
6813
calculations for a power amplifier for a dc motor  the design is
considered of valve circuits for driving low power motors such as
are often used in control or telemetry equipment
   /
6814
transistor operation stabilization of operating points  the provision
of optimum emitter and collector bias currents for a transistor amplifier
is discussed and a relation between the values of resistors and
voltages is derived which should be satisfied if stable operation
is to be achieved
   /
6815
transistor amplifier cut off frequency  the effect of the positive
feedback associated with the internal base resistance of a transistor
on its cut off frequency is analysed  expansion of the expression
for current gain in a taylor series shows that only the phase shift
in is important in reducing the cut off frequency
   /
6816
frequency variations of current amplification factor for junction
transistors  in a grounded emitter or grounded collector connection
of a junction type transistor the effective current amplification
is proportional to where is the current gain of the transistor  as
a result of the phase shift associated with the value of decreases
rapidly with increasing frequency so that the upper frequency limit
of the grounded emitter or grounded collector arrangements may be
considerably lower than has been expected  results of measurements
of the frequency variation of for several fused impurity pnp junction
transistors developed by saby below are shown graphically
   /
6817
the reproduction of voltage pulses by means of a proportional amplifier
analysis of an amplifier for nuclear physics investigations is based
on laplace transformations  a characteristic transmission function
is introduced which completely describes the transmission properties
of the amplifier and represents the combined pulse distorting influences
of the individual circuit elements  the transmission functions of
single stage and multistage amplifiers are derived and a detailed
and a detailed exposition is given of the distortion experienced
by a typical exponential decay pulse  optimum reproduction of such
a pulse requires a particular relation between pulse duration and
the time constants of the amplifier circuits  improvement of time
resolution involves closer restriction of this relation and greater
complexity of circuits  use of negative feedback offers advantages
a two stage feedback amplifier is a useful unit in a large amplifier
system  the transmission function can alternatively be determined
from the response of the amplifier to steady alternating voltage
a suitable method of measurements is described
   /
6818
a photocell amplifier for infra red spectroscopy  description of
a highly linear amplifier for use at a chopping frequency of  gain
variation is for variation of supply voltage
   /
6819
symposium on noise  general introduction  discussion of the mathematical
representation of noise
   /
6820
a coherent theory of relaxation phenomena  the theory presented is
based on the theory of functions  general formulae are derived and
the particular case of elastic relaxation oscillations is discussed
conditions for the occurrence of discrete and of continuous relaxation
spectra are determined and a formula is derived for the distribution
function of the continuous spectrum
   /
6821
on a multiple scattering theory of the finite grating and the wood
anomalies  the problem is treated by applying the solution previously
obtained of for multiple scattering from an arbitrary configuration
of parallel cylinders  both the transmission grating and the reflection
grating comprising semi cylindrical bosses on a perfectly conducting
plane are considered  the complete expression for the scattered wave
is given for the case of grating width small compared with distance
to observation point and cylinder spacing large compared with  the
case of raddi is investigated in detail bright and dark bands in
the intensity curves similar to the grating anomalies found by wood
in are related to the magnitudes and phases of the various orders
of scattering  the theory is extended to gratings with elements other
than cylinders
   /
6822
removal of an inconsistency in the theory of diffraction  in certain
cases the integral equations involved in analysis of the diffraction
of small amplitude acoustic or em waves give a solution which does
not satisfy the boundary conditions imposed but which agrees with
the solution found by other means  this inconsistency is removed
if different boundary conditions are imposed in the formulation of
the problem this is illustrated by discussion of two dimensional
diffraction of a plane em wave by a perfectly conducting semi infinite
plane
   /
6823
the rydberg constant and the atomic mass of the electron  re evaluation
of the spectro scopic data pertinent to the rydberg constant and
the mass of the electron yields the values r and atomic mass units
from microwave measurements and cm  houstons and chus data can be
brought into agreement with those of drinkwater richardson and williams
by assuming differences in the wavelength standards used
   /
6824
dielectric dispersion in pure polar liquids at very high radio frequencies
part the effect of electrolytes in solution  a description is
given of measurements at mm and cm wavelengths of the absorption
of electrolytic solutions of concentrations up to water and methyl
alcohol being used as solvents  the results obtained are analysed
in terms of debyes theory of dispersion in a polar dielectric and
modifications of the theory necessary to take account of the ionic
conductivity of an electrolyte are indicated  measurements on aqueous
solutions of are discussed in relation to huckels theory of electrolytic
solutions
   /
6825
piezoelectricity ferroelectricity and crystal structure  by visualizing
polar crystals as a network of permanent dipole moments the piezoelectric
and ferroelectric properties of dielectrics may be deduced from
considerations of molecular symmetry  this approach is used to clarify
the relation between the sphalerite cubic and wurtzite hexagonal
structures the ferroelectric feedback effect in aspects of domain
formation and the interrelation between ferro electricity and piezoelectricity
   /
6826
carriers of electricity in metals exhibiting positive hall effects
measurements on samples of mo and zn made by an inertia method showed
the sign of the charge mass ratio of the carriers to be negative
the mean value of over measurements being within of the value for
free electrons
   /
6827
electrical discharges in gases  a summarized account of six papers
with discussion presented at a meeting of section a mathematics and
physics of the british association belfast september
   /
6828
high frequency breakdown in neon  preliminary report of the results
of measurements of breakdown fields for cylindrical cavities of heights
and over the pressure range mm hg  a detailed p report is to be published
in the canadian journal of physics
   /
6829
an explanation of the extremely low normal running potential of a
high frequency discharge between plane plates  a tentative explanation
is provided by taking account in the equation of electron motion
of a restoring force indicated by plasma diffusion theory
   /
6830
chromatic losses of electrons in passage through matter  an account
of investigations of the velocity distribution of electrons after
passage through various gases and solid materials
   /
6831
the theory of secondary emission  preliminary note to be treated
in detail in a forthcoming paper
   /
6832
antiferromagnetism  a comprehensive review of the subject with references
   /
6833
a simplified form of the relativistic electromagnetic equations
maxwells equations are expressed in the form of a single four vector
density equation in which the field tensor has only three distinct
complex components  the number of equations is reduced but all the
usual classical formulae may be obtained by separating the real and
imaginary parts
   /
6834
the induction of electric currents in a uniformly conducting circular
disk by the sudden creation of magnetic poles  using toroidal coordinates
a riemann space of two regions is constructed as in sommerfelds
methods of multiform potentials and the riemann potential for a single
magnetic pole is determined  jeans treatment of uniform finite plane
current sheets is applied to the case of the circular disk numerical
results being given for a particular example
   /
6835
hertzian waves and photons  discussion of the implications in physical
theory of an uncertainty relation between the number of particles
of the bose einstein type associated with a wave and the phase of
that wave
   /
6836
diffraction of electromagnetic waves by apertures in plane conducting
screens
   /
6837
diffraction by an edge and by a corner  conditions are given which
are sufficient to ensure that the current density normal to an edge
is zero at the edge and that there is no line distribution of charge
on the edge  an extra condition is given which makes the components
of the field parallel to the edge finite  the solution is then shown
to be unique  simpler conditions are given for two dimensional fields
the agreement of various known solutions with the conditions here
determined is discussed  certain simple types of current and charge
distribution lead to a unique solution for the diffraction by corners
formed by flat surfaces
   /
6838
propagation of electric waves in stratified and continuously variable
plasmas  for a plasma of sandwich structure with the denser medium
inside there are two possible frequency ranges for propagation in
which the phase velocity falls from the value at the lower limiting
frequency to zero at the upper limiting frequency  when the density
varies linearly towards the interior to an arbitrarily high value
the wave is strongly concentrated at the plane for which and the
phase velocity tends to zero  for a plasma of uniform density and
natural frequency with outer layers in which density falls off linearly
propagation is possible only when  the more the wave is concentrated
at the region and the smaller its phase velocity the nearer approaches
to
   /
6839
hall effect  discussion of the hall ettingshausen nernst and righi
leduc effects
   /
6840
mean free paths of electrons in evaporated metal films  estimates
of the mean free paths of the conduction electrons in cu and ag films
based on resistivity measurements on films of thickness from to are
found to be in good agreement with values calculated from dingles
theory of
   /
6841
sunspot areas flares and filaments observed at the stockholm observatory
in the years and
   /
6842
comparison of photographs of the corona obtained at the eclipse of
february with simultaneous observations by lyot coronagraphs  photographs
of the solar corona taken at khartoum are reproduced and discussed
in relation to routine estimates of the intensity of the green corona
line  possible correlation of particular features of the corona with
geomagnetic effects is noted
   /
6843
the positions of six discrete sources of cosmic radio radiation
   /
6844
a preliminary survey of line emission from galactic hydrogen  report
of measurements on a radiation source having the form of a band of
varying intensity along the galactic equator
   /
6845
the ionic equilibrium of the lower atmosphere and recombination theories
   /
6846
a note on ionospheric wind measurements at  report of measurements
made in pennsylvania using a three receiver technique similar to
that of mitra
   /
6847
the ionization of the e layer its measurement and relation to solar
eruptions  criteria for distinguishing between normal and abnormal
layers are discussed  relatively thin layers are classed as abnormal
their ionization distribution corresponds to a power law with index
a definition of is given which remains valid for complex layers is
the highest critical frequency of a normal layer preceding or coinciding
with the first discontinuity between the e and f echoes  application
of this definition to the evaluation of ionosphere observations made
at freiburg during and leads to greater constancy of the daily variations
and monthly means of e  examination of the values of e for three
summer months indicates that all deviations above the monthly mean
are attributable to sudden ionospheric disturbances
   /
6848
the diffraction of galactic radio waves as a method of investigating
the irregular structure of the ionosphere  an account of an investigation
of ionospheric characteristics by observation of changes in the
diffraction pattern of radio waves from the galaxy  ionospheric irregularities
cause irregular changes of phase in the galactic waves passing
through them  observations at two stations about apart indicate that
such ionospheric irregularities may have a lateral extent of and
a variation of electron density of about their height is about they
are most pronounced about midnight and they show little annual variation
such portions of the ionosphere have a wind like motion with velocities
of the order of ms  the velocities are associated with periods
of geomagnetic disturbances
   /
6849
production of the e layer in the oxygen dissociation region in the
upper atmosphere  the probable value of the absorption cross section
of for the ionization causing the e layer is calculated using the
o height distribution data obtained by moses and wu of  discussion
indicates that the preionization by solar radiation in the range
suggested by nicolet of and ionization by high energy photons emitted
from the solar corona hoyle and bates of are both operative in producing
e layer ionization  the former produces the normal e layer and the
latter is responsible for the fine structure of the e layer recently
reported by naismith and bramley of
   /
6850
a new ionosphere sounder  frequency sweep apparatus covering the
range is described  the aerial circuit is eliminated the high impedance
rhombic aerial being directly matched to the power valves  the frequency
range is covered in the other circuits in two wavebands each with
a ratio quick waveband changing is achieved by means of carbon brushes
rotating with the variable capacitors  the transmitter and receiver
have a common oscillator  the power supply arrangements are particularly
described the unit is of small size
   /
6851
improvements to the berkner wells seaton type of ionosphere sounder
   /
6852
high altitude research  an account of methods and equipment used
with rockets for investigations at heights up to miles physical phenomena
observed include the ion and electron densities in the ion and
electron densities in the ionosphere  a description is given of a
channel telemetering system transmitting at with a peak power of
kw
   /
6853
ionospheric measurements at oblique incidence over eastern australia
   /
6854
localization of aurorae with high power radar technique using a rotating
antenna  radar equipment with a peak pulse power of  pulse width
and element yagi aerial rotating at rpm has been used since may at
kiruna geophysical observatory for the location of aurorae  preliminary
results of the observations indicate good correlation between auroral
activity geomagnetic activity and the appearance of the n layer a
special type of sporadic e ionization often appearing in connection
with magnetic bays  the distribution in range and bearing of the
recorded aurorae agrees with the simple theory that most of the radio
wave scattering comes from those points where the radar beam is perpendicular
to the surface of the auroral discharges  the calculated height
distributions of the reflection centres have maxima around km
   /
6855
propagation of very long electromagnetic waves and the wave spectrum
of lightning
   /
6856
servomechanisms a survey  design techniques discussed include frequency
and time analysis and statistical methods an indication is given
of problems not yet solved  references
   /
6857
nonlinear servomechanism  the various factors limiting the application
of the linear theory of servomechanisms are discussed the theory
of filtered systems using relays developed independently by dutilh
of and kochenburger is outlined and two net criteria applicable to
all filtered servomechanisms are established  the first criterion
is concerned with the possibility of hunting taking place and includes
the criteria of nyquist and kochenburger as special cases  the second
criterion determines the stability of such oscillations of the system
   /
6858
a formula for an integral occurring in the theory of linear servomechanisms
and control systems
   /
6859
application of transistors to high voltage low current supplies
a transistor oscillator is used to develop the hv required for such
devices as geiger muller counters  the oscillations have a sawtooth
waveform the flyback being used for shock excitation of the hv transformer
   /
6860
power rectifiers and transistors  power rectifiers with rectification
ratios as high as can be made by fusing donor and acceptor contacts
to the opposite faces of a ge wafer  analysis of the characteristics
of such rectifiers gives results in good agreement with experimental
values  the properties of transistors prepared in a similar manner
and capable of outputs as high as are described  at present the operation
of these power units is limited to about by transit time effects
   /
6861
a high voltage medium power rectifier  a description is given of
the operating characteristics of pnp junction rectifiers prepared
by fusing impurity metals to ge wafers  the addition of cooling fins
enables higher powers to be handled
   /
6862
the nevitron mercury arc rectifier  description of a new type of
rectifier with the hg pool in a mo cup with external al cooling fins
provided the mo cup is wetted by the hg to give a concave meniscus
the cathode spot runs in a continuous line round the edge of the
hg  the cooling system ensures no excessive emission of vapour  an
auxiliary electrode lifted from the hg by means of a solenoid serves
to start the arc  the voltage drop across the arc is  the weight
of a nevitron is only excluding the ignition solenoid  types with
grid control have also been tested  the power required in the grid
circuit for full control is only one thousandth of that for a multianode
rectifier
   /
6863
improved stabilization from a voltage regulator tube  by using a
suitable barretter in place of the resistor usually connected in
series with a voltage regulator tube a definite improvement in performance
is obtained  the barretter type of circuit is most useful when
the load current is relatively high
   /
6864
stabilizer for control of high direct voltages  the development and
performance of a stabilizer for direct voltages of the order of several
thousands of volts are described  the application of the stabilizer
to voltages of any value using as variable resistor a large number
of triode valves in series suppressing the voltage divider bridge
generally used to control the regulator system is also discussed
rectifier ripple can be eliminated so that a simple type of filter
can be used
   /
6865
the transbooster  description of circuits in which a transductor
is used for regulation of the output voltage of a rectifier fed from
ac mains under varying load conditions  if the transductor is connected
on the dc side of the main rectifier a smaller transductor can be
used since it will only have to handle the total boost voltage required
to cover rectifier regulation and mains voltage variation
   /
6866
automatic feedback control  theory and applications of servo control
systems
   /
6867
compensation against effects of grid cathode capacitance in pulse
height selectors  the precision of the selector may be reduced by
an effect due to the grid cathode capacitance of the input valve
when a constant current valve is used in the cathode circuit this
effect can be compensated by applying the input signal appropriately
modified to the grid of the constant current valve
   /
6868
the design of thermocouple transformers for infrared chopped beam
systems  description of transformer for operation at to be inserted
between a thermocouple detector and an amplifier the design is such
as to give at the amplifier output a signal noise ratio approaching
that at the thermocouple terminals
   /
6869
magnetic amplifiers  comment on of pistoulet pointing out the existence
of several french publications and patents on the subject one paper
by leonard and weber dating back to and thus being considerably prior
to the american paper by alexanderson and nixdorff quoted by pistoulet
as the first publication on magnetic amplifiers
   /
6870
a mathematical analysis of parallel connected magnetic amplifiers
with resistive loads  comment on
   /
6871
magnetic amplifiers for industry  description with outline circuit
diagrams of a series of westinghouse magamp instruments with power
ratings from to and examples of their application
   /
6872
new developments in fixed resistors for electronic applications
a review of the characteristics of deposited carbon metal film and
borocarbon resistors and comparison with carbon composition and wire
wound resistors
   /
6873
high temperature carbon film resistors  details are given of the
method of pyrolysis used in the production of stable carbon film
resistors with values from to and capable of operation at temperatures
up to  the carbon film is deposited on a porcelain base made from
alumina mixed with other ingredients such as and in an alcohol binder
   /
6874
industrial applications of semiconductors part thermistors  description
of the characteristics of thermistors typical forms of construction
and various applications
   /
6875
three phase transductor circuits for magnetic amplifiers  various
transductor connections for phase operation are described a element
circuit with separate excitation and a element circuit with auto
excitation are discussed in detail  a theoretical and experimental
comparison is made between single phase and phase circuits  the latter
should be used where balanced loading of the supply is sufficiently
desirable to compensate for the increased circuit complexity
   /
6876
the coupling of scale of two circuits  a simple and reliable rc divider
circuit is described and illustrated
   /
6877
ultra high frequency switches and filters  discussion pp  the design
of filters and switches for the london birmingham television relay
link is described  the type of switch adopted uses resonant stub
lines in shunt with the main transmission lines typical performance
details are given  the filters are of the band stop type and consist
of stub lines composed of a series of nominal line sections shunted
across the main transmission line  design curves are given and typical
filter attenuation curves shown
   /
6878
further data on the design of eccles jornan flip flops  full text
of paper presented at the aiee summer general meeting june  analysis
under specified conditions of the grounded cathode type of flip flop
circuit including no inductors  a graphical design technique is described
which should facilitate the design of switching circuits using
a large number of identical direct coupled circuits
   /
6879
fixed capacitors for electronic circuits  a review of the development
of new types involving both new materials and new manufacturing techniques
   /
6880
tuning stability nomograph  a chart is given for facilitating calculation
of the parallel capacitors required to give an overall temperature
coefficient of zero in circuits using inductance tuning
   /
6881
the calculation of energy flow using the laplace transformation
laplace perseval integral is applied to determine energy flow directly
from the laplace transforms of the applied force and the resultant
response  the method is applicable to both transient and steady states
and leads directly to the most simple form of solution  the method
is most advantageous when the applied force possesses several discontinuities
as an example the classical problem of eddy current losses
in linear sheet conductors is solved in general for arbitrary excitations
   /
6882
on transformations of linear active networks with applications at
ultra high frequencies  a relation similar to the star delta transformation
is developed for linear circuits including valves  formulae
are derived for triode circuits under the results are extended to
tetrodes and pentodes  the method is useful for analysing the operation
of uhf triodes and for determining amplifier admittances and gain
   /
6883
response of a quadripole to discontinuous signals  the phenomenon
of gibbs and methods of generalized summation  mathematical analysis
with application to the design of quadripoles with good transmission
characteristics for square wave signals
   /
6884
tunable rc bridge network with only one variable element  a circuit
is described with which an output of required phase is obtained by
varying either one resistance or one capacitance the magnitude of
the output voltage remaining constant  details are given of a stable
valve generator with frequency ranging from a very low value to
the circuit can also be used in phase shifters frequency meters and
selective amplifiers
   /
6885
a theory of time series for waveform transmission systems  a theoretical
study is made of time series suitable for application to low pass
systems with a fixed upper limit to the pass band  for division and
inversion of time series algebraic division is not in general legitimate
for time series related to bandwidth limitation although it is legitimate
for certain other forms of time series  more general methods of
inversion are treated and an iterative method which can always be
used is discussed in detail and a practical computing scheme is outlined
see also of january lewis which also deals with the time series
method
   /
6886
a wide band hybrid ring for uhf the bandwidth of a hybrid ring is
increased by replacing the long arm with a line and introducing a
frequency insensitive reversal of phase  calculations are made of
input and transfer admittances insertion loss and the effect of capacitance
across the loads  some experimental results are given and applications
to power splitters harmonic generators mixers are indicated
   /
6887
wave filter characteristics by a direct method  digest of paper presented
at the aiee winter general meeting january  a chart is given from
which the attenuation in db can be directly determined for seven
commonly used ladder filter sections the abscissae used being the
number of bandwidths from the cut off frequency
   /
6888
formulae for calculating filter circuits with flattened attenuation
curves  simple formulae are given for calculating tchebycheff type
low pass filters with attenuation values falling between prescribed
limits either inside or outside the pass band  attenuation curves
obtainable with filters thus calculated are shown
   /
6889
the transient response of rf and if filters to a wave packet
   /
6890
characteristics of the magnetic attenuator at uhf the design of the
field controlled attenuator previously described by reggia is discussed
and performance data are given for attenuators using various ferromagnetic
materials
   /
6891
new principle for electronic volume compression
   /
6892
loading of quartz oscillator plates  an investigation was made of
the effectiveness of mechanical loading for eliminating unwanted
modes of vibration and adjusting the oscillation frequency towards
the value corresponding to greatest activity  the loading was done
by applying various amounts of woods metal to different parts of
the plate surfaces  for concave thickness shear mode and x cut plates
improvement was obtained when the loading was applied at or near
the active central area for flat or convex x cut plates with an extensional
mode of vibration improvement was obtained when the loading
was applied near the periphery  for both types loading increased
the q factor
   /
6893
microwave cavity resonators as circuit elements  the differential
equation for the equivalent circuit of a double loop coupled cavity
resonator is derived by using lagranges equation and maxwells equations
the losses in the walls and the q of the cavity operating in the
te mode are evaluated
   /
6894
power spectrum of a nonlinear oscillator with a frequency amplitude
law perturbed by noise  discussion for the case where the dependence
of the frequency on the amplitude is represented by the formula and
the power spectrum is determined and can be represented as a single
line with a superposed noise spectrum resulting from the amplitude
and phase fluctuations  the methods previously developed and of enable
the noise spectrum to be resolved into a continuous band and a periodic
line component
   /
6895
multiple feedback oscillators  the use of several feedback circuits
in connection with a single tank circuit makes it possible to construct
oscillators capable of operation over a wide frequency range the
lc value of the tank circuit remaining fixed  such oscillators and
the theory on which they are based are described by m morrison in
usa patent no  important points of the theory are here given and
two typical oscillator circuits are described  in the second of these
a special current transformer with a ratio is used to effect phase
alteration of the feedback current  the transformer with a variable
capacitor across the output terminals is adjusted to provide feedback
current in phase with the ac component of the anode load current
so that the proper grid voltage angle is obtained for maintaining
oscillation at the desired frequency
   /
6896
constant amplitude oscillator  a circuit developed by nc hekimian
comprises a conventional oscillator whose rectified output is applied
as a positive voltage to the grid of a clamp valve which shares the
voltage dropping resistance in the oscillator anode supply lead
for a more detailed account see electronics
   /
6897
on an equation connected with the theory of triode oscillations
detailed discussion of the periodic solutions of the differential
equation in which the parameter is small  the equation is concerned
with the forced oscillations in a simple electrical circuit containing
a triode  van der pol has treated the case where and an extensive
theory of triode oscillations has been built up for this case  in
practice however  the graph of has a much flatter bottom than that
of the function and cartwright of and of has raised the question
whether this flattening will alter the performance of the circuit
near resonance  the main part of this paper is an attempt to answer
this question  an estimate is made of the permissible degree of flattening
of the curve without the detuning diagram losing any of its significant
properties  various pertinent theorems are established and the
possible periodic solutions of the equation are discussed in relation
to the detuning diagram  particular results include the following
a if k is small enough and the value of lies in a certain small range
near forced oscillations with half the applied frequency are possible
two of these have amplitudes very large compared with that of the
applied emf one mode being stable and the other unstable only when
the graph of is asymmetrical can there be an appreciable range of
values of for which subharmonic oscillations of order take place
   /
6898
pull in of nonlinear oscillators with filtered output  the effect
is considered of applying a small voltage of frequency to an oscillator
whose fundamental frequency has been freed from harmonics by filtering
a general formula is derived which gives the maximum value of for
pull in to occur  for the particular case of an oscillator with a
single oscillatory circuit the formula reduces to the known expression
q being the quality factor of the circuit and v the voltage amplitude
of the free oscillations  a formula is also given for the threshold
value of below which pull in is not possible
   /
6899
an x band sweep oscillator  a generator which sweeps through the
frequency band in sec is described a mechanically tuned klystron
is used  the output level is maintained constant to within db by
means of an automatic control circuit including a variable attenuator
with ferrite rotator unit above which also provides am at
   /
6900
production of standard waves with a impulse generator  equipment
installed at bangalore is discussed the characteristics of the generator
were determined experimentally a method of setting it up to produce
a desired standard waveform is described
   /
6901
multichannel crystal control of vhf and uhf oscillators  the frequencies
of a number of channels are controlled by a single crystal using
an oscillator whose phase is varied periodically by application of
pulses the oscillator output comprises a spectrum of harmonically
related frequencies whose fundamental is the crystal controlled pulse
frequency  a particular triode oscillator covers the range with fundamental
in the range  by appropriately tuning the tank circuit any desired
harmonic can be emphasized by an amount up to
   /
6902
methods of reducing the ratio of noise to signal at the output terminals
of amplifiers  a summarized account of earlier work by the author
alone or in collaboration with a van der ziel  see of and
   /
6903
the design of amplifiers for the birmingham manchester coaxial cable
description with schematic circuit diagrams of a line amplifier suitable
for the transmission of line television signals on a carrier or for
telephony channel groups on diameter coaxial cables a constant gain
amplifier for the transmitting terminal  practical difficulties which
limit the performance of the amplifiers and associated transformers
are discussed and possible improvements for future designs are suggested
   /
6904
the maestro a power amplifier  description with complete circuit
details of a new version of the musicians amplifier with an output
of  a pair of rca type beam power valves operated in class ab are
used with a specially designed peerless output transformer type s
q  power supply circuits are also described
   /
6905
new medium cost amplifier of unusual performance  description with
circuit details of an amplifier with the necessary flexibility and
performance for most high fidelity applications only standard readily
available valves are used
   /
6906
essential similarity and relations between amplitude and phase distortions
in video amplifiers  in the complex method of e representation
the transmission function of a video amplifier for steady oscillations
can be regarded as the sum of an ideal transmission function and
an error function  the error function is applied in investigating
the relations between an arbitrary transmission function with superposed
amplitude and phase errors and the associated distortions for the
minimum phase shift condition  the investigation gives an insight
into the physical relation between the distortions  the formulae
derived are applied to determine the distortions for a sytem with
a tchebycheff type transmission function these distortions are then
compared with those for a system with a steady fall of amplitude
near the cut off frequency
   /
6907
the direct voltage valve amplifier  effects of valve and circuit
noise fluctuations of the current source and temperature changes
are evaluated  a review of basic amplifier circuits for measurement
purposes illustrates different directly coupled interstage and output
arrangements and methods of compensating the above effects  methods
of amplification involving modulation are noted
   /
6908
the parallel t dc amplifier a low drift amplifier with wide frequency
response  the frequency response of a modulated dc amplifier is broadened
by the parallel addition of a conventional ac amplifier which
has inherently a response capable of being made complementary to
that of the dc amplifier  the result is a homogeneous design without
excessive phase shift  circuit details are given of an amplifier
designed for use with a high speed pen recorder in the frequency
range  the avoidance of direct coupling renders the use of electrometer
valves unnecessary
   /
6909
feedback amplifier design  discussion of the pole pattern required
for a low pass amplifier with overall feedback  analysis is presented
for an amplifier whose gain function contains no internal zeros and
for which the feedback fraction is independent of frequency  a general
solution applicable to any number of poles is obtained for the case
of critical damping  for amplifiers with maximally flat response
curves of graphical solutions are given for systems with n poles
where n ranges from to  the synthesis of a prescribed pole pattern
is considered and the method of realizing conjugate poles by feedback
pairs id described
   /
6910
two simple types of feedback amplifier for the relaying of television
signals over coaxial cables  discussion a method is described for
applying negative feedback to flatten the gain frequency characteristic
of stage amplifiers using tuned anode intervalve couplings resonant
at the mid band frequency  two typical amplifiers are described
   /
6911
summarized proceedings of a conference on microwave physics  oxford
summaries are given of the papers presented and of the subsequent
discussions
   /
6912
diffraction of a shock or an electromagnetic pulse by a right angled
wedge  solutions given in a previous paper of keller and blank are
used as a basis for calculating the field distribution comparison
with measurements made for the acoustic case shows satisfactory agreement
   /
6913
precision determination of the velocity of light derived from a band
spectrum method  detailed report of the work noted in of  the value
obtained for the velocity is km sec
   /
6914
extension and more exact statement of the analogies between electrical
and mechanical devices
   /
6915
electrical and mechanical analogies  an introduction to the study
of general problems concerning electrical networks and mechanical
systems whose operation is governed by linear laws  matrix symbolism
is explained by examples and a table of elementary electrical and
mechanical analogues is given  application of the theory is made
to discussion of the characteristics of transducers such as loudspeakers
and piezoelectric or magnetostrictive generators
   /
6916
diracs new classical theory of the electron  diracs new theory and
is shown to arise as a limiting case for both the particle and wave
theories for continuously distributed charge it is equivalent to
the maxwell lorentz theory
   /
6917
number theory and the magnetic properties of an electron gas
   /
6918
application of the theory of numbers to the magnetic properties of
a free electron gas
   /
6919
a direct comparison of the kelvin and electron beam methods of contact
potential measurement
   /
6920
the poisson kelvin hypothesis and the theory of dielectrics  a comprehensive
critical review of fundamental mathematical theory  electrostatics
only is considered but the treatment indicates that a complete reconstruction
of electrodynamic theory is essential
   /
6921
an optical method for determining the complex dielectric constant
and the magnetic permeability a method applicable in the cm and mm
wave ranges is described which depends on determination of the normal
incidence reflection and transmission factors of a plane parallel
plate  the calculation is based on the general matrix equations of
the field as derived from maxwells equations
   /
6922
the mean free path of conduction electrons in bismuth  experimental
results for bi single crystals are given from which it is concluded
that in agreement with the suggestion of sondheimer of the mean free
path of the conduction electrons in bi is much longer than in normal
metals and that for electrons travelling perpendicular to the triad
axis the path length is probably in the range at room temperature
   /
6923
secondary processes active in the electrical breakdown of gases
results of recent investigations indicate the complexity of gas breakdown
mechanisms  three cathode mechanisms and two anode mechanisms
are analysed and their relative importance and the conditions for
their occurrence are discussed  they lead to the same type of generalized
threshold breakdown condition subject to statistical fluctuations
and to space charge effects  this condition masks the active processes
and renders analysis difficult  the various factors affecting the
discharge are considered n and proper methods of discharge investigation
are indicated
   /
6924
the mechanism of field dependent secondary emission  an account of
experiments made to test the theory that the mechanism of field dependent
secondary emission is similar to that of the townsend avalanche
in gas discharges  special tubes were used having dynodes with a
porous coating  the results indicate tht the high yield of secondaries
is independent of the base material  the variation of secondary current
with field strength was in accordance with the gas discharge equations
this was confirmed by retarding field measurements of the energies
and mean free paths of the secondaries  the time required for the
surface to become charged was determined by using pulsed bombarding
currents and was found to be consistent with the theory
   /
6925
recombination of gaseous ions  recombination between positive ions
and electrons and between positive ions and negative ions are considered
separately since the nature of the processes involved and the experimental
techniques for observing them are quite different in the two
cases  although there is still little information about the rate
of recombination of positive and negative ions at low pressure there
has been substantial clarification of the processes of electron ion
recombination during the last two years due to the application of
microwave techniques  the knowledge of the mechanism of electron
ion recombination derived from both theory and experiment is reviewed
in detail and a shorter account given of present knowledge of ion
ion recombination at pressures less than that of the atmosphere
recombination phenomena in the ionosphere in the solar corona and
in interstellar gas are also discussed briefly  references
   /
6926
antiferromagnetism and ferrimagnetism  the holweck lecture may reviewing
the present state of knowledge of antiferromagnetism including ferrimagnetism
and describing interesting phenomena related to the magnetic
properties of certain ferrites and of pyrrhotite
   /
6927
spin degeneracy and the theory of collective electron ferromagnetism
a model is discussed for which the results obtained by neglecting
or taking account of spin degeneracy are identical  the model can
be treated exactly and leads to equations for the free energy magnetization
etc which are a generalization of those of stoners theory of
collective electron ferromagnetism of
   /
6928
zeners treatment of ferromagnetism  a critical review of zeners theory
   /
6929
the theory of ferromagnetism and heisenbergs model
   /
6930
some magnetic properties of metals  part diamagnetic resonance  em
radiation incident on a large system of electrons moving in a constant
magnetic field h in a metal is strongly absorbed near a frequency
where m is the effective mass  the resonance absorption is of the
same order of magnitude as the absorption due to skin effect part
of
   /
6931
some magnetic properties of metals part properties of small systems
of electrons  a calculation is made of the magnetic properties of
a system of electrons within a cylinder of very small radius with
its axis parallel to the field direction  the expressions obtained
for magnetic susceptibility thermodynamic potential and specific
heat contain a steady term which remains of significant magnitude
at all temperatures together with terms periodic in the field which
are significant only at very low temperatures  the influence of electron
spin is discussed  similar calculations are made for a small spherical
system
   /
6932
the limits of total reflection part rigorous wave theory calculation
the variation of intensity in the region of the critical reflection
angle is calculated numerically for a particular case previously
considered by ott of  the curve obtained indicates a continuous variation
from the region of partial to that of total reflection
   /
6933
propagation of a wave front in anisotropic dispersive media  extension
of work previously noted of february to the case of anisotropic media
expressions are derived for the velocity of propagation and for the
field in the vicinity of the wave front
   /
6934
determination of nuclear moments from hertzian spectra  discussion
of the interaction between nucleus and electron and an account of
the principal methods apart from resonance methods of applying microwave
spectroscopy to the determination of nuclear moments
   /
6935
the velocity distribution of sporadic meteors part  extension of
the work noted in part of to the investigation of fainter meteors
similar results are obtained
   /
6936
the velocity distribution of sporadic meteors part calculation of
the theoretical distributions  a general method is described for
estimating the field of view of any aerial system and hence of predicting
the ratio of true to observed hourly numbers for particles of
different velocity and flight direction  part above
   /
6937
relation between geomagnetic activity and solar radio activity  a
fuller account of work noted previously of denisse steinberg and
zisler
   /
6938
the representation of the main geomagnetic field and of its secular
variation by means of two eccentric dipoles  a model comprising two
dipoles is suggested to account for the second order terms in the
expansion representing the geomagnetic potential  the systematic
displacement of the dipoles with time explains certain features of
the geomagnetic secular variation  the model provides a generally
improved approximation to the actual surface geomagnetic field
   /
6939
theories of magnetic storms and aurorae  the discussion of theories
advanced by alfven and martyn of
   /
6940
slide rule computes radio refractive index of air  details are given
of methods developed at the national bureau of standards for computing
atmospheric rf refractive indices from radiosonede meteorological
data using special types of straight or circular slide rule  the
methods give adequate accuracy for almost any conditions likely to
be encountered in the troposphere
   /
6941
ozone in the earths atmosphere  general discussion of processes involved
in the formation of ozone methods of measuring z ozone content and
its vertical distribution in the atmosphere and variations of ozone
content with meteorological conditions
   /
6942
ionosphere review  curves are given for the period showing monthly
mean values month running averages of sunspot numbers and noon and
midnight f critical frequencies  from these it appears probable that
both sunspot numbers and critical frequencies will continue to decrease
slightly during
   /
6943
recent advances in auroral spectroscopy and in our knowledge of the
upper atmosphere
   /
6944
auroral effects on television
   /
6945
the propagation of a radio atmospheric part
   /
6946
transients in nonlinear servomechanisms with filters  continuing
previous work of equations are derived for amplitude and elongation
a complex function of time for the case of small damping and a new
construction o for point to point tracing of the xt curve is indicated
which furnishes a new criterion of stability of steady states of
oscillation
   /
6947
the pulse transfer function and its application to sampling servo
systems  a method of analysis of sampling in a linear system is described
which is based on a sequence transformation closely analogous
to the laplace transform  the pulse transfer function relates a sequence
of samples at the output of the system to the input sequence of pulses
producing it  servo systems with a finite time delay in the feedback
loop are particularly considered  a list of transforms is provided
in an appendix
   /
6948
the design and testing of an electronic simulator for a hydraulic
remote position control servo mechanism  discussion
   /
6949
exceptionally stable regulated power supply for electrometer tubes
description of a two stage regulator circuit delivering about at
with the output regulated to within several parts per million for
line voltage changes of  drift of the output voltage is about parts
per million per hour  theory construction details and results of
performance tests are given
   /
6950
radiofrequency power supply  brief description of a circuit designed
for a maximum current output of an output voltage of being provided
by means of a chain of wire wound resistors  the variation of the
dc output voltage measured over a period of hours was part in
   /
6951
compensation of feedback control systems subject to saturation  a
theory for the design of compensating networks for feedback control
systems and filters is developed  the novel feature of this theory
is its consideration of saturation and transient performance in addition
to the usual steady state behaviour  this theory is essentially an
extension of the researches of wiener and lee in statistical methods
for filter design  saturation is handled by limiting the rms signal
levels at critical points in the linear model used as the design
basis for the physical system  transient performance is handled by
limiting the integral square errors to a set of transient test signals
   /
6952
corona discharge tubes for voltage stabilization  the mechanism of
the corona discharge is briefly described by reference to the current
voltage characteristic of the glow discharge tube  the construction
processing and performance of experimental coaxial types of tube
are discussed  the data presented are sufficient for the design of
tubes with regulating voltages between and operating at currents
up to at least  such tubes can be made with characteristics stable
for over hours
   /
6953
the importance of frequency rate indication in the control of the
national grid  description of the construction and use of equipment
indicating time error mains frequency error and rate of change of
mains frequency  the unit comprises a mains frequency  the unit comprises
a mains driven and a tuning fork controlled motor both coupled
to a differential gear whose output shaft moves only when the mains
frequency differs from  systems of differentiators and geared counters
operate the indicating instruments
   /
6954
initial conditions in transient analysis  in a paper on network theory
of lee and macdonald indicated the equivalence of a charged capacitor
and the series combination of an uncharged capacitor and a battery
extension of this idea to consideration of inductors leads to a simple
method of analysing initial conditions  the method is elucidated
by two theorems and examples the laplace transform treatment is used
   /
6955
transient conditions  by transformation of the fourier integrals
to obtain a series development of bessel functions expressions have
been derived for certain transient response characteristics  these
included the response of a low pass and a high pass lc ladder filter
and of a homogeneous transmission line to unit step and sinusoidal
voltage input when the system is terminated by its image impedance
   /
6956
reduction of carrier frequency build up process to a complex low
frequency process  the laplace transform method is used  by applying
the displacement law the distortion of a carrier envelope due to
a linear transmission element can be calculated directly  vestigial
as well as symmetrical sideband systems can be dealt with in this
way
   /
6957
a turns index for pulse transformer design  by assuming certain ratios
between core and coil dimensions which represent average values of
normal practical designs it is found possible to generalize design
relations so that coil and core dimensions are eliminated from first
design considerations the only parameter remaining being that of
the turns of the windings  for a step up pulse transformer of ratio
a formula is given for the number of turns on the secondary in terms
of performance requirements and properties of the dielectric and
magnetic materials used  the formula was checked against actual values
for existing transformers covering a range of pulse widths from to
and secondary voltages from to
   /
6958
a mathematical analysis of an inductively loaded parallel connected
magnetic amplifier
   /
6959
a multichannel switch for operation in a microwave circuit  description
of a rotating disk type of switch for cro display of a rapid succession
of pulses picked up by a number of probes arranged at different points
along a waveguide passing signals
   /
6960
e c class resistors  discussion of performance characteristics of
highly stable resistors consisting of a thin conductive coating on
heat resistant glass  ratings range from to  resistance change is
for temperature cycles between and
   /
6961
the design of single phase transductors
   /
6962
a ferromagnetic scaling circuit  each incoming pulse triggers the
discharge of a capacitor through the primary coil on an iron wire
core  the maximum voltage of the pulse induced in the secondary depends
on the core magnetization and thus on the number of incoming pulses
on reaching a preselected level a thyratron is fired and operates
a mechanical counter the core being restored to its initial state
of magnetization  scales of up to are stable in operation  design
details and theory are discussed
   /
6963
gated decade counter requires no feedback  decade counting is achieved
in a system using binary type counting circuits by arranging that
eight pulses are directed into one storage circuit and the next two
pulses into a second storage circuit after which the systems resets
itself
   /
6964
counting pulses of various forms and occurrence intervals by electronic
counters  modifications to univibrator circuits are described which
prevent retriggering during the recovery period or provide a retriggering
characteristic permitting the recording of overlapping pulses
or both
   /
6965
maximum power in termination impedors  an analytical proof that power
is a maximum when the resistive component of the load is equal to
the internal resistance of the source and the reactive components
cancel out  the principle can be extended to the case of a quadripole
by reformulating the helmholtz equations
   /
6966
the power of nonsinusoidal systems  a calculation is made of the
instantaneous power absorbed by a series lrc circuit with a nonsinusoidal
periodic applied voltage  the square of the apparent power is
the sum of the squares of l all the component powers for all the
harmonics including so called mutual terms involving harmonics of
different order
   /
6967
the optimum piston position for wide band coaxial to waveguide transducers
matching of a coaxial line to a waveguide can be effected by
means of a probe located ahead of a short circuiting piston in the
waveguide  matching can usually be achieved by varying any two of
the following dimensions off centre distance of the probe probe length
distance from piston to probe  as there is theoretically an optimum
piston position giving greatest bandwidth it is convenient to vary
dimensions and  experimental results are quoted which corroborate
the theory  bandwidths to the swr points were obtained
   /
6968
a highly stable variable time delay system  description with detailed
circuit diagrams of delay systems in which distributed amplification
is used to compensate the losses in the linear delay elements  time
jitter is extremely low  two practical circuits have maximum delays
of and per step and per step respectively
   /
6969
theory of the compensated delay line  analysis based on an equivalent
ladder network indicates that for a certain compensating capacitance
a constant delay can be obtained over a predetermined frequency range
calculations are made for compensating rectangular plate capacitors
results are presented in a graph useful for design  the results are
in good agreement with those of kallmann of and others
   /
6970
synthesis of terminal pair networks  to realize a quadripole ladder
network comprising only reactive elements and with prescribed transfer
function five general conditions must be satisfied  these are discussed
with particular reference to the synthesis of a ladder network consisting
of a number of l sections in cascade all the sections except one
comprising only inductors and capacitors  a simple method of completely
determining the transfer function of such a network is outlined
   /
6971
four terminal networks  a rigorous theory of passive quadripoles
in the steady state is presented  the general quadripole is regarded
as consistent of n meshes and the equations for the system as a whole
are obtained by solving the equations for the meshes  iterative and
image impedances are obtained as properties of a single quadripole
and a suitable propagation function is associated with each pair
of impedances  conditions in quadripoles in two types of cascade
arrangement can be deduced immediately from the equations for a single
quadripole  tables are included giving expressions for the image
functions in terms of the iterative functions and vice versa and
giving the equations of the quadripole in terms of the iterative
and image functions
   /
6972
new linear passive nonreciprocal microwave circuit component  a note
calling attention to the fact that the magneto optic element producing
the faraday rotations previously reported by goldstein et al  of
and of constitutes a network element of the tellegen gyrator type
se also of hogan
   /
6973
a theorem on ideal transformer networks  by applying the principle
of duality to an impedance inversion network a general theorem on
ideal transformation of voltage current and both voltage and current
is derived  provided the resistive components of reactors are sufficiently
small the theorem may be applied in designing networks which
can be tuned by a single control through a range of frequencies with
fixed transformation ratio to give a variable transformation ratio
at a fixed frequency
   /
6974
exact amplitude frequency characteristics of ladder networks  a basic
theory of the low pass ladder networks is developed on similar lines
to dishals treatment of  the theory can be applied by well known
analogies to the derived band pass high pass and band stop filters
two types of desired frequency response curves are considered the
butterworth and tchebycheff types general solutions are obtained
for both  the results are applied to many practical problems including
the use of networks for coupling a valve to a resistive load or to
another valve power bandwidth and gain bandwidth curves being determined
for particular cases  impedance matching between a generator and
its load is also considered and matching networks are designed  examples
are also given of the design of low pass and band pass filters with
either the butterworth or the tchebycheff type of response many useful
design curves being given
   /
6975
alignment and adjustment of synchronously tuned multiple resonant
circuit filters
   /
6976
manufacture of microstrip  illustrated description of processes in
the manufacture of microstrip components  see also grieg and engelmann
assadourian and rimai and kostriza of march
   /
6977
automodulation in ferroresonance  automodulation of forced oscillations
in ferroresonant circuits  ie circuits containing nonlinear reactive
elements is considered  the following examples are examined circuit
with a thermistor circuit with a capacitor whose value depends on
the field and on temperature an es voltmeter connected to a ferroresonant
circuit  the stationary operating conditions and their stability
in such circuits are discussed and the depth and period of automodulation
are determined  the discussion is limited to cases in which the
circuit is nearly of the linear conservative type and the variations
of amplitude and phase are slow in comparison with the period of
the external force
   /
6978
a criterion of stability for oscillations in n mesh networks with
varying parameters  analysis given previously of is generalized to
apply to any network in which some or all of the capacitances or
inductances vary periodically  conditions necessary for the growth
of free oscillations having small initial amplitudes are investigated
the system is represented by a determinant equation from whose roots
the stability conditions are derived
   /
6979
fixed length transmission lines as circuit elements  resonant systems
consisting of fixed length transmission lines with a capacitor at
each end have decided advantages compared with short circuited transmission
line sections for use at frequencies of the order of  analysis
is presented which leads to simple graphical determination of the
line and capacitor parameters  the analysis is extended to include
interstage coupling circuits and wide band coupling of an aerial
to the output stage of a transmitter  numerical examples are given
   /
6980
the measure of activity for oscillating quartz crystals in parallel
resonance circuits  the concept of performance index is explained
this is the effective parallel resistance r of the resonant crystal
shunted by a specified capacitance  a method of measurement of r
is described  load current density should be specified when quoting
r
   /
6981
the stability of quartz oscillators  supposing a a series connected
crystal in a resonant lc circuit to be short circuited the relative
detuning f due to the presence of the crystal is termed the stabilization
factor  different arrangements of meissner hartley and colpitts
circuits are considered  the most stable circuit is one in which
f is a maximum compatible with oscillation and is independent of
change in the valve interlectrode capacitance and the load current
through the crystal  the properties of a circuit in which the crystal
acts as an inductance are similar in all respects to those of a circuit
with the crystal operating at series resonance
   /
6982
methods for improving the frequency stability of transmitters
   /
6983
equations for the natural frequencies of coupled circuits from the
quadripole viewpoint part  theory previously given of is extended
to the case of a six terminal network with both series and parallel
connected resistance  the biquadratic equation for a coupled system
is expressed by two binomials one referring to the circuits uncoupled
the other occupation binomial taking account of the coupling data
two schemes for formulating this occupation factor and associated
expressions probably cover all cases of coupling by a single resistor
   /
6984
quartz crystal circuit with variable coupling as oscillator and discriminator
the principle of the fm oscillator described is the use of
two coupled tuned circuits the second of which has a crystal connected
in parallel  a reactance valve drives the oscillator valve which
has the first circuit connected between anode and a capacitor connected
to the grid with anode feed to the centre tap on the inductor  the
relative frequency swing attainable is from to parts in  impedance
diagrams for the circuit are shown  the principle is also applied
in a discriminator in which the centre tap of the second circuit
inductor is connected through a large value capacitor to the anode
side of the first circuit the coupling between the inductors being
variable  the centre frequency of this discriminator is largely independent
of the characteristics of the rectifying diodes
   /
6985
wien bridge oscillator design  a set of curves is presented which
allows direct determination of design parameters of wien bridge oscillators
and selective amplifiers
   /
6986
perturbations of filtered oscillators  the amplifier of an oscillator
is assumed to be filtered to isolate the fundamental frequency so
that the oscillator responds to excitation by a synchronous sinusoidal
oscillation  an equation for the oscillator perturbations is developed
which involves the partial derivatives of the gain and phase  from
this equation th existence of a synchronization threshold can be
demonstrated for the general case  when the perturbation is below
this threshold frequency pulling occurs
   /
6987
the lock in performance of an afc circuit  for t the case of rc coupling
between phase detector and reactance valve in an afc system an explicit
relation is derived which determines the lock in condition in an
afc system using a reactance valve controlled oscillator  the relation
involves the filter time constant the initial frequency error the
phase detector constant and the sensitivity of the oscillator
   /
6988
analysis and performance of locked oscillator frequency dividers
employing nonlinear elements  locked oscillator frequency dividers
can be stabilized by inserting certain nonlinear elements in the
oscillator circuits  these elements should have a characteristic
such that the voltage is proportional to an integral root of the
current through them  if this condition is satisfied the locked oscillator
divider is almost completely insensitive to wide changes of anode
voltage driving signal voltage and driving frequency  the mathematical
representation of the nonlinearity of the elements permits some analysis
of the circuit nonlinear differential equations  thyrite elements
or varistors were used in experimental circuits for division by or
   /
6989
calculation of the harmonic distortion in sinusoidal modulation of
frequency or phase detailed study of a quadripole with antiresonant
circuit  the fm voltage applied to the input terminals of an arbitrary
quadripole is expressed by a convergent fourier series  an expression
is deduced for the tangent of the variable phase shift introduced
by the quadripole in the form of the quotient of two rapidly convergent
series of bessel functions which lend themselves well to numerical
calculation  three parameters are involved the wave length the modulation
index m and the ratio of to the qu factor of the parallel rlc
circuit considered  numerical calculations are made for eight cases
of practical interest involving different values of m and  the results
given by the complete formulae for the harmonic distortion are compared
with those obtained by application of the instantaneous frequency
rule
   /
6990
a ferroelectric amplifier  a lf signal was applied to a capacitor
with ceramic dielectric thereby causing its capacitance to vary
the capacitor formed part of a tuned circuit fed by a hf voltage
the resulting am hf voltage was applied to a detector circuit to
recover the signal  analysis for this arrangement indicates the conditions
for maximum amplification  with a signal frequency of hf of
and load resistance a power gain of was obtained  with the signal
source removed and the output fed back to the input terminals sustained
lf oscillations were obtained with only the hf voltage applied  the
oscillation frequency could be varied continuously from to by varying
the value of a rf choke in the input lead and of a capacitor in the
detector circuit  see also of vincent
   /
6991
distributed amplifiers mutual inductance coupled type  design procedure
is outlined the problems of output voltage and output matching being
considered in detail  a method involving over running the valves
is described for increasing gain and output while maintaining the
time delay constant when amplifying random pulses  details are given
of the construction and performance of two amplifiers having a useful
bandwidth of
   /
6992
cathode follower operation  comment on of
   /
6993
rc or direct coupled power stage  analysis is performed for an rc
or direct coupled output stage consisting of an ideal triode of resistance
anode feed resistance r and load resistance r to determine the
relations between and for maximum efficiency  the formula derived
is evaluated for some particular cases
   /
6994
transistor circuits  by appropriate use of transformers transistor
circuits having characteristics similar to those of ordinary valves
can be obtained  calculations are given for several particular cases
   /
6995
noise in transistor amplifiers  conditions for obtaining optimum
signal noise ratio are indicated for amplifiers using point contact
and junction type transistors  graphs show the dependence of noise
figure on operating point and for a two stage amplifier on the source
impedance of the second stage  see also of march and of montgomery
   /
6996
mathematical aspects of the quantum theory of fields part boson field
in interaction with a given source distribution
   /
6997
mathematical aspects of the quantum theory of fields part occupation
number representation and fields of different kinds
   /
6998
gravitation and electrodynamics  a modification of einsteins unified
field theory is proposed and its physical implications are examined
   /
6999
further experimental investigations on the nature of light  experimental
arrangements are described for obtaining a photographic record of
the effect of a strong nonuniform electric field on a light beam
a photometric record of the variation in diffraction due to such
a field  the deviation of the beam which occurs when the plane of
polarization is perpendicular to the direction of the field is discussed
in relation to the em theory of light
   /
7000
diffraction of electromagnetic waves by an aperture in an infinite
screen  an approximate solution is derived for conditions of normal
incidence on a perfectly conducting screen  the method is applicable
where the aperture is large compared with and reduces the problem
to one of scalar boundary values
   /
7001
diffraction field of a circular aperture  an equation expressing
the diffracted field is derived for the case of a normally incident
plane wave and a perfectly reflecting screen  the equation is of
the form given by stratton of but is modiffied to agree with certain
theoretically and experimentally established conditions
   /
7002
a new method of solving diffraction problems  a double approximation
method is indicated for dealing with various problems on the diffraction
of em waves
   /
7003
application of the methods of optics to calculations of diffraction
phenomena in the centimetre wave range  analysis and examples illustrating
the use of kirchhoffs theory for approximate calculation of diffraction
effects both for centimetre em waves and for sound waves
   /
7004
angular momentum in diracs new electrodynamics
   /
7005
the energy momentum tensor in diracs new electromagnetic theory
   /
7006
diffraction by a charged filament  the deflection of an electron
by a charged infinite filament is considered and an equation is derived
determining its trajectory
   /
7007
interpretation of the electron inertia experiment for metals with
positive hall coefficients  a critical discussion of the measurements
described by brown and barnett of march
   /
7008
interpretation of em values for electrons in crystals  the e values
obtained by brown and barnett of march are shown to be in agreement
with established theory if the mass of the holes is considered to
be negative
   /
7009
mobility in high electric fields  conductivity theory is extended
to the case of strong es fields all electron collisions being assumed
to be elastic  a relation is derived between mobility and relaxation
time which is valid over a wide range of field strengths
   /
7010
the anomalous skin effect  measurements were made on a number of
metals at frequencies of and at temperatures in the range  the variation
of rf surface conductance with dc conductivity agrees well with the
theoretical prediction of reuter and sondheimer of assuming that
the electrons are scattered diffusely when they hit the surface of
the metal  the results are used to estimate the effective value of
mean free path of electrons the estimate for cu agrees well with
that based on theory but those for ag and au are rather lower than
the theoretical values  the results are largely dependent on the
surface condition of the metal the use of the two different frequencies
enables the influence of this factor to be assessed
   /
7011
the influence of the surface states of electrons on the optical properties
of semiconductors and dielectrics  the reflection of em waves
from a plane surface with electronic surface conduction is considered
for incidence angles close to reflection increases with the angle
when the electric vector is parallel to the surface but decreases
when the electric vector is almost perpendicular to the surface
   /
7012
experimental verification of the relationship between diffusion constant
and mobility of electrons and holes  short pulses of electrons or
holes were injected into single crystal rods of p and n type ge
as the pulse travelled along the rod under the influence of an electric
field diffusion took place resulting in broadening of the pulse
a large number of measurements of pulse widths and transit times
for two positions of the emitter point were made and the most probable
value of the ratio of diffusion constant to mobility was derived
by the method o of least squares  this was found to verify the relation
see of
   /
7013
corona suppression methods  physical aspects of corona discharge
are discussed and its prevention by pressurization or evacuation
of electrical equipment by increasing the radii of curvature of conductors
and by coating with or immersion in materials of high dielectric
strength is described
   /
7014
the single electrode discharge at pressures from a few millimetres
of mercury to atmospheric pressure at the frequency of  experiments
were conducted with discharges in air n and ar to investigate the
characteristics of the torch discharge
   /
7015
formative time lags of uniform field breakdown in n
   /
7016
dynamics of plasma part plasma with neutral gas  continuation of
work noted in of  to illustrate theory it is applied to investigate
the influence of self magnetic field on a glow discharge
   /
7017
longitudinal waves in an ionized medium plasma  the permittivity
of an electronic plasma is calculated taking account of electron
motion the value found depends on the spatial structure of the field
a concept of spatial dispersion is introduced  the properties of
longitudinal waves and their relation to transverse waves are investigated
   /
7018
crystal structure and antiferromagnetism in haematite
   /
7019
ferromagnetism at very high frequencies part  temperature dependence
of the magnetic spectrum of a ferrite  continuation of work noted
in of rado et al  observations at and are reported by using single
domain particles embedded in wax the rotational resonance was observed
separately  the resonance frequencies decrease with increasing temperature
a theoretical interpretation is given  auxiliary measurements
of the spectroscopic splitting factor saturation magnetization and
coercive force are described
   /
7020
the distribution of currents in a disk rotating in a uniform magnetic
field and the damping
   /
7021
application of the calculus of variations to the determination of
reflection coefficients  the method previously used to determine
the reflection coefficient of a potential barrier of is here applied
to the vector field of em waves to determine the reflection coefficient
of a stratified medium for te and tm waves
   /
7022
the complete system of natural electromagnetic oscillations of a
biaxial anisotropic parallelepiped  analysis of the em field inside
a rectangular cavity resonator completely filled with an optically
biaxial crystal
   /
7023
propagation in electron ion streams  mathematical theory is developed
for streams composed of n discrete beams  the solution of the propagation
equations is obtained in vector form by an extension of hansens
theory and takes explicit account of initial and boundary conditions
when certain restrictions are placed on the transverse boundary conditions
the general solution satisfying arbitrary initial conditions
can be expanded in terms of a complete orthogonal set of elementary
vector solutions  for this case the necessary and sufficient conditions
are found for amplification and instability in the terminated and
the unterminated stream  the analysis is extended to a continuous
velocity distribution  see also of
   /
7024
a broad band coaxial stark cell for microwave spectroscopy  the cell
consists of a coaxial structure long the outer conductor being of
brass tube and the inner of brass rod the ends are vacuum sealed
only a single wave transmission mode is possible in the operation
range  the application of a voltage between the conductors at some
predetermined repetition rate modifies the variation of the absorption
with the frequency of the rf wave field thus facilitating detection
of resonance  see also
   /
7025
apparatus for zeeman effect measurements on microwave spectra
   /
7026
the connection between transverse magnetogalvaniic effects and resistivity
the magnetogalvanic rotation due to the hall effect in an isotropic
conductor is expressed in terms of transverse magnetogalvanic conductivity
its variation with temperature and field intensity is discussed
briefly with reference to ferromagnetic and super conducting media
   /
7027
a radar investigation of the delta aquarid meteor shower of
   /
7028
effects of solar radiation in the upper atmosphere  an account is
given of the various radiations emitted by the sun and of the ionization
and dissociation effects resulting from their absorption in the upper
atmosphere
   /
7029
solar enhanced radiation and plasma oscillations  the dispersion
formula for plasma oscillations in a static magnetic field is derived
by the laplace transform method used by landau of the oscillations
are unstable in frequency bands around multiples of the gyrofrequency
numerical calculations for sunspot magnetic fields in the corona
indicate that random fluctuations may be amplified and afford support
for the explanation given by wild of enhanced radiation
   /
7030
solar activity and the atmosphere  statistical analysis of records
confirms that correlation exists between geomagnetic disturbances
and fluctuations of atmospheric pressure over scandinavia  the hypothesis
of planetary influence on solar activity is discussed  assumptions
regarding the mechanism of the suns influence on the atmosphere are
justified by measurements
   /
7031
the physical conditions in large sunspots deduced from their spectra
the temperature electronic pressure and gas pressure at the centre
of a large sunspot are determined from published spectral data
   /
7032
provisional sunspot numbers for july to september
   /
7033
the corona and geomagnetism  discussion of available data for the
present solar activity minimum shows the existence of a tendency
for the central meridian passages of moderately bright regions to
be followed by reduced geomagnetic activity for about three days
   /
7034
effects of the solar eclipse of february on the ionospheric f region
over equatorial africa  detailed note of effects observed in ionosphere
soundings at bangui  these are interpreted satisfactorily in terms
of the existence of two interspersed layers x and g comprising the
f region  the lower x disappears as ionization decreases during occultation
during the reionization process which occurs more rapidly at
the base of the layer than at the top the lower regions of x merge
with the f layer  the comparative insensitiveness of the upper layer
g can be explained on the basis of corpuscular radiation
   /
7035
on some possible mechanisms of radio stars part  neither the deflection
of fast electrons nor transitions of thermally excited electrons
can account for the observed intensity of radiation
   /
7036
the determination of the position of a radio star  discussion of
the accuracy of different methods
   /
7037
the measurement of the angular diameter of radio stars  the phase
switching interferometer method described by ryle of is considered
in detail and measurements made by this method are reported
   /
7038
electromagnetic radiation from cosmic protons and the rf radiation
from the galaxy  calculations indicate that galactic rf radiation
may be originated by the proton component of cosmic rays when the
latter pass through the galactic fields
   /
7039
a new discussion of the changes in the earths rate of rotation  a
detailed analysis of available information on changes in the rate
of rotation of the earth since
   /
7040
a negative experiment relating to magnetism and the earths rotation
an experiment was made to determine whether a cm gold cylinder rotating
with the earth produced a weak magnetic field no such field was observed
the magnetometer used is described in detail
   /
7041
the electromagnetic field of a rotating uniformly magnetized sphere
   /
7042
the variation of the geomagnetic activity recurrence interval with
the solar cycle
   /
7043
cheltenham three hour range indices k for july to september
   /
7044
isolation of the eleven yearly variation of the horizontal component
of the earths magnetic field by linear combinations of ordinates
the ev eleven yearly component is brought into evidence by using
labroustes method of analysis  this component has in general a minimum
value years after the maximum of sunspot activity and a total amplitude
of gamma  exceptional results observed for certain stations are discussed
   /
7045
on variations of the geomagnetic field fluid motions and the rate
of the earths rotation  brouwers results above are compared with
changes with time in the westward drift of fluid moving near the
surface of the earths central core as inferred from the westward
drift of the eccentric dipole field of geomagnetism
   /
7046
principal magnetic storms
   /
7047
international data on magnetic disturbances second quarter
   /
7048
measurement of tropospheric index of refraction fluctuations and
profiles  results are presented of measurements made with a direct
reading microwave refractometer over the sea and coastal areas near
lakehurst nj and over southern ohio for heights up to  the refractometer
was essentially the same as that previously described by crain
   /
7049
some reactions occurring in the earths upper atmosphere  the photo
chemical reactions determining the equilibrium between n n no and
no are examined  the origin of the no in the atmosphere is discussed
a considerable yield is necessary to balance the loss due to photodissociation
this gas may be formed in the troposphere by collisions
between o or o and n
   /
7050
the height of the atmospheric electric equilibrium layer  continuation
of previous work by israel and kasemir the values of electron concentration
corresponding to two limiting assumptions regarding dependence
of recombination coefficient on pressure are compared with values
deduced fro determinations of d layer ionization is found to be proportional
to the cube root of the pressure  the height of the equilibrium
layer is about km
   /
7051
relations between temperature and the phenomena of photochemical
dissociation or ionization in the upper atmosphere particularly in
the e layer  a calculation of the initial kinetic energy of oxygen
atoms produced by photodissociation of oxygen molecules gives a value
corresponding to a temperature at altitudes between and
   /
7052
a new early morning ionospheric phenomenon  kodaikanal records indicate
the cessation of ionospheric echoes some minutes to several hours
before sunrise and their reappearance at about the time of ground
sunrise on about of days during theflecting layer on reappearance
of the echoes was km  on mornings when the echoes did not disappear
the new reflecting layer appeared suddenly and its height decreased
rapidly to that of the overnight layer viz km
   /
7053
investigation of the ionizing effect in the e layer near sunrise
virtual height time records for signals show a sudden decrease in
virtual height around ground sunrise  analysis for the period jan
dec shows that the difference between time of occurrence of the sunrise
drop and sun rise at the reflection level is constant and independent
of season  absorption is considered the most likely cause of this
effect  calculations of absorption coefficients for o n and o give
results of the right order of magnitude in the case of only  ionization
of o could be caused by ultraviolet radiation of
   /
7054
the f layer at dakar and the motion of the sun  the occurrence of
a layer between the normal f and f layers has been reported previously
of delobeau et al  the results of observations for the period july
to july are shown graphically and discussed  curves for summer winter
and the equinoxes showing the number of occurrences of the f layer
for each hour of the day are of similar shape with maxima shortly
after local time the curves dropping to zero at about and  the seasonal
curves show maxima about the summer solstice and minima at about
the winter solstice  similar effects thick f layer have been observed
at singapore of osborne
   /
7055
solar ionospheric tides in the f region  the equation of continuity
for electrons subject to the influence of a vertical drift harmonic
in time has been integrated by numerical methods taking the processes
of ion production and recombination into account for physica conditions
representative of the f region  the results of the analysis are applied
to a brief discussion of the nature of the information regarding
the vertical electron drift which can be derived from measured ionospheric
data
   /
7056
some practical determinations of the electron content below the level
of maximum ionization in the f region of the ionosphere  ratcliffes
method of was applied to results of observation at slough and at
singapore during and to simultaneous observations at penang and singapore
during one week of july  seasonal and diurnal variations of maximum
electron density differ from those of the total number n of electrons
in a vertical column of unit cross section in the f region up to
the level of maximum ionization  the variations of n show a greater
dependence on the solar zenith angle  diurnal variations of the latitude
gradient of n near the magnetic equator are briefly discussed  it
apper probable that as the latitude alters the local noon value
of n goes through a flat maximum in equatorial latitudes whereas
the noon value of maximum electron density goes through a sharp minimum
near the magnetic equator and exhibits the well known equatorial
trough
   /
7057
the differences in the relationship between ionospheric critical
frequencies and sunspot number for different sunspot cycles  statistical
analysis of data from washington dc and watheroo australia shows
significant differences for months near the equinoxes and also seasonal
variations between the and cycles  inconclusive results for other
months are ascribed in part to the small sample size of available
data  for radio propagation predictions therefore only current cycle
data should be used
   /
7058
calculation of absorption in the ionospheric propagation of short
waves  formulae and graphs necessary for calculation of the absorption
in the absence of and in the presence of the geomagnetic field are
assembled and explained
   /
7059
conductivity of the ionosphere  the investigations of various workers
relative to balfour stewarts dynamo theory of geomagnetic diurnal
variations are reviewed and the fundamental principles involved in
the production of electric currents in the ionosphere by tidal winds
are reexamined  three conductivities two of which are related to
the hall effect appear to be involved  one of these has two relatively
small maxima at km height due mainly to ions and due to electrons
the second has a broad maximum at thus including all the e region
ionization and the third has a very pronounced sharp maximum at km
discussion shows that the effective conductivity of the ionosphere
over most of the earth is some twelve times greater than that deduced
when the hall current is ignored and near the magnetic equator the
conductivity is increased further by a factor of  equations developed
appear to account quantitatively for the high conductivity required
by the dynamo theory and also for the increased conductivity near
the magnetic equator  near the equator the current system should
be in a relatively thin layer centred at about km height  evidence
of the existence of a current sheet between the and levels has recently
been obtained by singer et al  in rocket experiments
   /
7060
dynamo currents and conductivities in the earths upper atmosphere
discussion of the results of rocket measurements reported previously
of  the observed current system would account for the exceptionally
large geomagnetic diurnal variations found at huancayo and strongly
supports balfour stewarts dynamo theory of the diurnal variations
by taking account of polarization due to the hall effect the large
discrepancy between conventionally calculated ionosphere conductivities
and the value of the conductivity required by the dynamo theory using
accepted values for the velocity of high altitude winds can be eliminated
further rocket measurements on both magnetically quiet and disturbed
days are very desirable
   /
7061
studies of the atmospheric potential gradient no current theory f
the electric field in the air particular cases arising from the theory
given previously of are examined in detail using moderately advanced
mathematics
   /
7062
studies of the atmospheric potential gradient no examples of atmospheric
electrical phenomena in foggy conditions  from an examination of
numerous records of the atmospheric electric field and the vertical
current obtained at stations in lowland and mountainous regions during
fog several types of characteristic reaction are distinguished these
are discussed in detail
   /
7063
theories of the aurora polaris  the discussion presented deals only
with theories based on the action of streams or clouds of neutral
ionized gas ejected from the sun
   /
7064
the teometry of radio echoes from aurorae
   /
7065
the streaming of charged particles through a magnetic field as a
theory of the aurora
   /
7066
landolt bornstein zahlenwerte und funktionen aus physik chemie astronomie
geophysik und technik vol astronomie und geophysik  j bartels
and p ten bruggencate volume eds  publishers springer verlag berlin
gottingen e heidelberg should be available in any library catering
for meteorologists geophysicists or astronomers  no book written
in english contains such a useful and complete collection of information
   /
7067
stability of control systems  study of a common type of equation
   /
7068
converting direct voltage to alternating voltage at high power  description
of a unit providing a supply for a radio beacon at schiphol
an inverter circuit with balanced hg vapour filled thyratrons is
used and the maximum continuous power output is with an overall efficiency
of  considerably higher supply frequencies can be provided by
using thyratrons with different gas fillings
   /
7069
use of a bridge circuit for supplying several loads independently
from a common voltage source  a circuit suitable for measurement
purposes and adapted for both dc and ac supplies has the source arranged
in one arm of a bridge and two loads respectively in the two diagonals
modification to accomodate more loads is indicated
   /
7070
design of series peaking transformers  essential features of this
type of transformer are the load current is arranged to be negligible
compared with the magnetizing current and the magnetizing current
is allowed to reach a value much greater than that required to saturate
the core  an easy and accurate design method is presented which does
not require an analytical representation of the by bh characteristic
the example of a transformer to produce a voltage pulse of about
for triggering a thyratron is worked out numerically  the voltage
and duration of the pulse can be predicted to within about of the
measured values
   /
7071
investigations on voltage transformers  a conductance diagram is
developed to show directly the variation of secondary voltage and
phase angle as a function of the load  its application in transformer
design is illustrated
   /
7072
dc ac converter utilizing the space charge capacitance of a valve
two circuits are described for converting feeble dc to ac prior to
amplification for measurement purposes  both make use of the variation
of grid cathode capacitance with the voltage applied to the grid
the first circuit using a bridge balanced for a certain value of
the grid cathode capacitance so that any variation produces a proportionate
deflection of a meter  the second circuit uses a balanced arrangement
of two valves with a differential transformer  zero stability
is good in both cases
   /
7073
transistor equations  formulae giving circuit voltage and current
gain and impedance characteristics in terms of transistor parameters
are tabulated for grounded base grounded emitter and grounded collector
transistor amplifier circuits
   /
7074
static dynamic design of flip flop circuits  discussion of the design
of flip flop circuits for operation from a relatively low supply
voltage a desirable feature for computer elements  the circuit adopted
uses negative pulse triggering and a diode input circuit the minimum
trigger voltage being adjustable by means of two variable resistors
stability is determined by use of rouths criteria  general directions
for the design of flip flop circuits for low voltage operation are
summarized
   /
7075
design of low frequency constant time delay lines  analysis is presented
for ladder type low frequency delay lines consisting of pierce asymmetrical
t sections each section having two unequal coils in series wound
on a common core to give a coupling coefficient near unity a capacitor
being connected from the junction of the coils to earth  when properly
terminated such delay lines give delays constant to within over of
the pass band  where many sections must be used they have the decided
advantage of requiring only two components per section a double winding
inductor and a capacitor
   /
7076
transfer matrix of a four terminal passive network in terms of its
image parameters  the constants in the fundamental simultaneous equations
relating the input and output voltages and currents for a linear
passive quadripole have a particular significance and can be used
to derive the transfer matrix of any passive network in terms of
the image impedances  this is demonstrated for the l type of network
   /
7077
the measurement of a matrix elements of passive networks  th general
method of using the a matrix has previously been described of  a
method is here described for determining the matrix elements from
measurements of the impedance looking in at the sending nd of a network
the receiving end being first open circuited and then short circuited
the elements so found apply only for the measurement frequency  the
analysis shows that networks are electrically equivalent at a given
frequency when their a matrices are equal at that frequency
   /
7078
the maximum gain of an rc network  analysis is presented indicating
that any desired voltage gain can be achieved at a given real frequency
by using networks of sufficient complexity as represented by the
degree of the corresponding formulae  transfer function theory developed
previously of is used  the relation between the maximum possible
gain and the degree of the transfer function is determined  the results
are illustrated by examples
   /
7079
note on a network theorem  the formulation adopted by zepler of is
criticized and it is shown that his results can be obtained more
simply by using the conventional impedance concept rather than his
unconventional power concept
   /
7080
waveform computations by the time series method  discussion on paper
abstracted in of january
   /
7081
the synthesis of a network to have a sine squared impulse response
discussion on paper abstracted in of february
   /
7082
reduction of the loss in ferrite materials in the microwave region
the loss in microwave gyrators of the type comprising a ferrite rod
inside a circular waveguide surrounded by a solenoid producing an
axial magnetic field has in certain cases been reduced by application
of an auxiliary transverse static magnetic field
   /
7083
filter transfer function synthesis  theory is developed for circuits
in which approximately constant attenuation is achieved over one
or more frequency bands  an electrostatic potential analogue method
is used see of klinkhamer  the method is applied to some examples
of low pass filters
   /
7084
a systematic procedure for the design of filters  continuing previous
work on the formulation of the characteristic functions of filters
of tables are developed which facilitate the determination of the
circuit elements of coupling free filters of various types
   /
7085
multistage band pass filter with optimum approximation to the ideal
rectangular shape of the response curve
   /
7086
the design of linear phase low pass filters  discussion  general
design principles are outlined and a method applicable to certain
low pass filters required in television equipment is described  adequate
phase linearity of response can be obtained over the whole pass band
only by limiting the discrimination required in the attenuation region
of the insertion loss characteristic  practical examples include
a set of low pass filters with linear phase characteristics from
zero nearly to their cut off frequencies which range from to an asymmetric
sideband filter with a cut off frequency of and phase linearity
from to with discrimination above
   /
7087
how to use mechanical if filters  discussion of the construction
and performance of electromechanical filters using magneto strictive
ni wires as coupling units between metal disk resonators  a typical
disk filter has a bandwidth of centred on with a transmission loss
and an operating temperature from to c  the size of the complete
assembly is only in
   /
7088
fundamental results and outstanding problems of network synthesis
   /
7089
synthesis of n terminal pair e networks  dissipative networks only
are considered  generalization of the gewertz reduced matrix e method
and three methods involving auxiliary reactive networks are outlined
and critically reviewed  the first auxiliary reactive network method
considered was developed independently by oono of and leroy of and
of the second was due to bayard of and the third to belevitch of
   /
7090
recmf exhibition preview  short descriptions of selected exhibits
at the exhibition arranged by the radio and electronics component
manufacturers federation london april
   /
7091
piezoelectric oscillations of quartz plates at even and half odd
harmonics  a number of quartz plates of different dimensions were
plated with ag al or cu by various methods and tested in the same
circuit  results show that a quartz plate has preferred modes of
oscillation at the odd and even harmonic and at frequencies mid way
between these though the amplitude of the odd harmonics is very much
the greater
   /
7092
the double resonance in the secondary of a system of two circuits
with inductive coupling  the resonance condition is defined in terms
of the primary and secondary impedances and the mutual inductance
the variation of secondary current with the coupling frequency and
series capacitance is determined  in the case of a variable frequency
with fixed coupling a graphical method is used to derive equal current
curves  by means of these a region can be defined within which two
resonance peaks occur
   /
7093
some exactly integrable cases of electromagnetic oscillations in
two coupled cavity resonators  calculations of resonance frequencies
are made for cavity configurations whose boundaries coincide with
co ordinate surfaces of an elliptical cylindrical co ordinate system
the expressions obtained are developed explicitly for the case of
weak coupling and are compared with known approximations
   /
7094
theory of forced oscillations in electrodynamic systems  the method
of analysis using vector series progressing according to the eigenfunctions
of the wave equation is applied to a system comprising cylindrical
resonator and coaxial line  the theoretical assumption underlying
the method are examined and the green tensor appropriate to linear
electrodynamic processes is formulated
   /
7095
the complete system of natural electromagnetic oscillations of uniaxal
anisotropic cavity resonators  analysis of the field inside an arbitrary
cylinder completely or partially filled by a uniaxal crystal  the
special cases of the circular section cylinder and the parallelepiped
are treated explicitly  see also of may
   /
7096
perturbations of filtered oscillators part  results previously obtained
of may regarding the stability synchronization and frequency pulling
of a nonlinear oscillator subjected to excitation by an external
source are generalized by considering the dependence of amplifier
gain on the rate of phase change
   /
7097
nonlinear oscillators and the nyquist diagram  two types of nonlinear
oscillators having amplitude limiting are considered  their equations
become linear when a particular value is chosen for the parameter
involving the amplitude  a single curve can then be drawn for this
particular value on the same principle as the ordinary nyquist curve
other values of the parameter yield a family of curves showing the
stages in the evolution of oc oscillations  conditions for stable
and unable oscillations are derived and the results extended to cover
response to a small perturbation frequency stability and synchronization
limits  a brief account of part of the work was given in and of
   /
7098
electrical and acoustic oscillation build up phenomena  mathematical
treatment of build up phenomena such as those investigated experimentally
by trendelenburg et al of for organ pipe sounds
   /
7099
multimesh rc networks for phase shift oscillators  the required phase
shift for each mesh is calculated for a terminated mesh network
the values which total differ considerably from
   /
7100
a wide range oscillator of high stability  description of a beat frequency
oscillator for the rf system of the birmingham university proton
synchrotron of hibbard  the two similar oscillators used are tuned
by coaxial resonators on rubber shock mounts in a constant temperature
enclose the fixed frequency oscillator operating at about  a capacitor
using a single plate rotor with a stepped profile serves for varying
the tuning of the other oscillator via a servomechanism  the beat
frequency as a function of rotor setting is reproducible to within
throughout the range
   /
7101
a phase shifting pulse generator for thyratron control  description
with detailed circuit diagram of equipment producing positive pulses
with repetition frequency that of the mains but with phase variable
with respect to that of the supply voltage  the phase lag is controlled
by application of a small direct voltage to the grid of a high vacuum
valve
   /
7102
pulse operated time bases  discussion of the basic principles and
description f a practical timebase circuit of the single sweep type
triggered by a delayed pulse developed from the transient or transmitter
pulse to be examined
   /
7103
timebase circuits  discussion of the principles of operation of various
types of timebase including an anastigmatic system and of hv generation
by the fly back method
   /
7104
the three possible types of valve amplifier circuit and applications
in television receivers  analysis and comparison of grounded cathode
grounded grid and grounded anode amplifier circuits
   /
7105
a selective detector amplifier for  an amplifier is described for
use as a detector in bridge or other measurements where a null indication
is required  tuning is accomplished by means of parallel t feedback
networks including only resistors and capacitors  noise is equivalent
to an input signal of across
   /
7106
background noise in ionization chamber pulse amplifiers  two methods
of particle energy measurement are considered  for the charge collection
method milatz and keller of have calculated the absolute limit to
measurement accuracy for the amplifier circuit used  for the pulse
slope method initiated by sherr and peterson a slightly different
limit is found  circuits giving optimum signal noise rato are proposed
in each case
   /
7107
constant current audio power amplifiers  the design features are
discussed of a push pull amplifier using a pair of type valves in
the output stage to feed a general radio type toroidal output transformer
constant current operation of the output stage with resistors
in the cathode leads for dc degeneration minimizes variations due
to valve aging or replacement  full circuit details of the amplifier
and its simple power supply unit are given
   /
7108
comments on the performance of pentode output stages  except from
book of the phillips series of books on electronic valves of
   /
7109
the differential amplifier  comment on of and authors reply
   /
7110
electrically tuned rc oscillator or amplifier  two variants are described
of a feedback circuit including two all pass phase shifting networks
tuning is performed by adding a variable amount of the output of
the one phase shifter to the output of the other the variation being
controlled electronically by means of a modulator circuit  theoretically
the tuning range is from zero to infinite frequency in practice the
frequency ratio obtainable without appreciable change in gain is
about
   /
7111
fundamental problems of hf and if amplifiers for tv reception part
gain and bandwidth  the gain bandwidth product gb is shown to depend
exclusively on the ratio of valve mutual conductance to the sum of
input and output capacitances  factors affecting g and b are discussed
amplifier response curves are considered and the total bandwidth
is deduced for amplifiers with synchronous circuits  staggered tuning
is discussed in detail  the unit function response curves for double
and vestigial sideband systems are treated and the distortion in
the latter system is analysed  the gain and bandwidth of quadripole
coupling networks particularly the network and the double tuned band
pass filter are discussed and characteristic data including gb values
are tabulated for nine commonly used pentode circuits  data for unit
function response curves when several identical groups are connected
in cascade and bandwidth factor for double tuned coupling circuits
are also tabulated
   /
7112
fundamental problems of hf and if amplifiers for tv reception part
noise  noise factors of amplifiers operating under various specified
conditions are calculated and valve noise is discussed  formulae
are derived for the noise factor at metre wavelengths for four special
simplified cases a general formula being given in an appendix  the
concept of noise reference frequency the frequency the frequency
at which the equivalent noise resistance of a valve is equal to the
input resistance is discussed and formulae are tabulated for both
triode and pentode circuits with predominating partition noise  graphs
of noise factor for various cases show that above the frequency the
noise factor increases rapidly  the signal noise ratio is calculated
from the noise factor  it appears that the weakest signal that can
be received reasonably well depends on the frequency on the aerial
noise and particularly on the noise reference frequency of the first
valve of the receiver
   /
7113
the first boundary value problem of maxwells equations  mathematical
analysis of the generation of oscillations in an em system by an
external source such as excitation of a cavity resonator by means
of a waveguide feeder
   /
7114
refractive index of dipolar gas mixtures at decimetre wavelengths
the refractive index of mixtures of air and water vapour was measured
at frequencies from to over a range of pressures using a cavity resonator
method  results are shown in curves  discrepancies between the
observations and values predicted from theory are attributed to the
fact that the relaxation time of the water molecules is not negligible
at low pressures
   /
7115
capture and recapture of electrons in phosphorescence  the relative
importance of these phenomena is discussed and the mechanisms with
which they are associated in phosphorescence decay are analysed
   /
7116
the luminescence of phosphors in strong electric fields  the account
of the phenomenon of electroluminescence given by destriau see eg
of is critically discussed  cells used for demonstrating the phenomenon
always take the form of a stratified capacitor including a layer
of gas and a layer of solid dielectric of much greater breakdown
strength the gas being occluded either in the electrodes or in or
between the phosphor grains  with such an arrangement a glow discharge
occurs in the gas layer for voltages above a certain threshold and
below sparking voltage  it is concluded that this is the true explanation
of the observed phenomenon
   /
7117
circulation in the flow of electricity  diracs new variables  kelvins
circulation theorems are shown to be applicable to the generalized
momentum vector in the relativistic flow of electricity  vortex filaments
become vortex ribbons in space time and diracs variables and are
identified as the parameters which characterize the family of vortex
ribbons
   /
7118
the electric potential in an electrically shielded space  experiments
confirm the previously observed variation of potential inside a metallic
enclosure the phenomenon is attributed to the production of space
charge by ionization due to spontaneous radiation from the enclosure
walls
   /
7119
the frequency dependence of the dielectric properties of dipolar
substances  inconsistencies in previous theories of dipolar interaction
are pointed out  a new theory presented is based on debyes theory
of molecular relaxation and on an application of onsagers method
for treating es interaction
   /
7120
 neoc the solution of the schrodinger equation for finite systems
with special reference to the motion of electrons in coulomb electric
fields and uniform magnetic fields
   /
7121
motion of gaseous ions in strong electric fields  amplified and extended
version of papers noted in of and of february
   /
7122
current flow in cylinders  the mixed boundary value problem of the
flow of current into a right circular cylinder through a perfectly
conducting coaxial disk electrode at one end is solved approximately
   /
7123
numerical calculation of the potential and field due to a uniformly
charged disk  various methods of calculating the potential at any
point are discussed the particular advantages of the relaxation method
in the most general case being pointed out
   /
7124
new types of discharge in magnetic fields  discharge phenomena described
by ehrenhaft et al  are explained in terms of known concepts and
laws ogas discharge physics
   /
7125
investigations of discharges in magnetic fields  a note on righis
magnetic rays
   /
7126
the microwave admittance of a mercury vapour discharge
   /
7127
theory of the discharge potential for coaxial cylindrical electrodes
in a transverse magnetic field
   /
7128
the absorption and reflection of microwave radiation by a mercury
vapour discharge  results of measurements at show that with increasing
discharge current the real component of the complex conductivity
of the discharge increases almost linearly the imaginary component
which is negative increasing nonlinearly ad and less rapidly
   /
7129
the imaging properties of electron beams in arbitrary static electromagnetic
fields  detailed theory of the aberrations of electron optical
systems with curved axes with application to calculation of the imaging
properties of a helical beam moving in the field of a pair of coaxial
cylindrical electrodes
   /
7130
the secondary emission from copper and silver films obtained with
primary electron energies below  values obtained for the secondary
emission ratio are lower than those hitherto recorded both ag and
cu having a ratio in the primary energy range ev  the difference
is attributed to the improved vacuum conditions used  measurements
of the energy distribution of the secondary electrons for primary
energies show that the secondary electrons are in fact elastically
reflected primary electrons
   /
7131
electromagnetic properties of plasmas  conditions for the propagation
of longitudinal and transverse em waves are considered taking account
of the effect of collisions on electron velocities and assuming no
applied magnetic field  the mobility coefficient relating the electric
field to the mean velocity imparted by it to the electrons and dispersion
formulae linking wavelength and frequency of the propagated disturbance
are derived
   /
7132
studies in magneto hydrodynamics  a systematic treatment of the subject
designed to bring out the underlying physical principles  basic equations
for em phenomena in a conducting liquid and their conditions of
validity are discussed  these are applied in specific static kinematic
and dynamic problems  experimental work is briefly summarized
   /
7133
a new type of propagation  discussion of the properties of magneto
hydrodynamic waves in various types of conducting gluids  see also
of
   /
7134
overlapping energy bands and the theory of collective electron ferromagnetism
   /
7135
motions of material particles in the field of an electromagnet description
and discussion of two different effects observed when ferromagnetic
particles of order of magnitude cm are exposed to fields of strength
up to oersted in the air gap of a magnet
   /
7136
the behaviour of ferromagnetic particles in a rotating magnetic field
account of an experimental investigation of the motion of ferromagnetic
particles of order of magnitude cm suspended in gas at pressures
between and mm hg and subjected to illumination and to a magnetic
field rotating at
   /
7137
theory of diffraction by a cylinder taking account of the surface
wave  maxima and minima observed by a limback in diffraction of centimetre
em waves by metal cylinders are found to be due to interference
between the waves geometrically reflected from the cylinder surface
and the surface wave creeping round to the b ck of the cylinder
quantitative calculations based on the integral equations of the
diffraction theory of give results in good agreement with experiment
   /
7138
diffraction patterns in circular apertures less than one wavelength
in diameter  measurements were made of the field intensity at points
along the aperture diameters parallel respectively to the electric
and magnetic vectors using normally incident radiation of wavelengths
cm and cm  the results disagree with values calculated from youngs
theory in two respects viz the observations indicate a sharp increase
at the ends of the diameter parallel to the magnetic vector the observed
central peak for apertures of diameter near was greater than the
calculated value the high intensity being attributed to multiple
reflections from the edges
   /
7139
the electromagnetic field in the plane of a circular aperture due
to incident spherical waves  measurements were made of the field
in an aperture of diameter cm illuminated with radiation of wavelength
from small radiators at various distances  results are shown graphically
the curves obtained can be represented approximately by a modified
form of andrews equation of
   /
7140
application of matrices to the problem of transmission through a
multi layered dielectric wall  the matrix methods described by watson
are applied to the determination of design formulae for dielectric
walls of the symmetrical sandwich type
   /
7141
the physical conditions in sunspots deduced from their spectra  discussion
of the theoretical consequences resulting from the sunspot model
recently proposed  the vertical gradient of the magnetic field
is found to be about gauss km
   /
7142
nomograms for the computation of tropospheric refractive index  charts
for calculating refractive index refractive index discontinuities
and vertical gradient are presented in a form convenient for use
with standard radiosonde data  they are valid for wavelengths cm
   /
7143
humidity of the upper troposphere and lower stratosphere over southern
england  detailed report of observations made on flights during at
altitude
   /
7144
abnormalities in the ionosphere at high latitudes  study of the variations
with respect to time and location of the frequency of occurrence
of storm s types e and d shows that the polar region may be divided
into three zones the polar zone the storm belt and the polar quiet
zone  within the storm belt the most dense forms of storm e ionization
are practically confined to an area centred near canada  while the
existence can be demonstrated of two centres of activity in the d
region spaced apart which rotate once around the earth every hours
   /
7145
geo morphology of f region ionospheric storms  f region ionospheric
storms may be regarded as manifestations of a single world wide
phenomenon viz the es field of the solar diurnal current system whose
local effects depend markedly on local time ad a season  the theoretical
chapman characteristics of the f region are normally perturbed by
solar tidal electric fields of  during magnetic storms the phase
of the additional electric field present is such as to increase these
perturbations at high latitudes and to reduce them at low latitudes
though the effect may be masked by local time variations of ionization
density  in contradistinction to appleton and piggott of no evidence
is found that any magnetic storm affects the northern and southern
hemispheres differently when due allowance is made for the seasonal
effect
   /
7146
study of the ionosphere by extraterrestrial radio waves  a paper
surveying experimental work on the use of galactic rf radiation for
investigating ionospheric refraction absorption irregularities and
the effects of sudden ionospheric disturbances  results are compared
with theory and further lines of investigation are suggested
   /
7147
e region during the solar eclipse of february analysis of observations
of e layer critical frequencies at khartoum during the eclipse indicates
tht the ionizing radiation from the solar disk is not uniformly distributed
as is also the case for the optical radiation  part of the u
nonuniform component of the ionizing radiation appears to be divided
about equally between the east and west limbs of the sun  this is
consistent with observations made at meudon of the distribution over
the suns disk of the intensity of the green coronal line  the main
discrepancy between the values of the parameter proportional to the
radiation flux calculated from the coronal data and from the e region
measurements appears abruptly just after totality and suggests the
existence of an intense source of ionizing radiation near the west
limb of the sun which cannot be explained in terms of solar data
available at present
   /
7148
a study of ionospheric winds and turbulence utilizing long radio
waves  an experimental investigation of winds in the e layer was
made during the period july march using vertical incidence pulse
technique with waves of frequency  the time variations of the reflected
amplitudes are analysed statistically and compared with results to
be expected from theory  fades of duration min are most prevalent
diurnal and seasonal effects are observed  see also of march
   /
7149
a high precision ionospheric sounding equipment  description with
circuit diagrams and oscillograms of high resolution equipment which
provides pulses variable from t in duration and from to in peak power
the delta aerials are of the type considered by cones of  alternative
terminations giving improved signal strength at frequencies  during
conditions of severe interference a horizontal receiving dipole is
used  interchangeable receivers covering a bandwidth of are provided
the timebase circuit previously described of is modified to give
a line raster each line corresponding to height  the evaluation of
resolution is discussed in an appendix
   /
7150
effect f the geomagnetic field on the absorption of short waves in
the ionosphere vertical incidence  an approximate formula for the
index of refraction is used to calculate the coefficient of absorption
for five frequencies around  the results are sensibly the same as
those obtained by use of the rigorous appleton hartree formula those
previously given by argence mayot and rawer or of are about higher
   /
7151
the reflection and absorption of radio waves in the ionosphere  investigations
of the absorption of rf waves made in britain since are reviewed
and the theory f ionospheric absorption is outlined  the effects
of double refraction polarization spatial attenuation dispersion
ionospheric inhomogeneities and partial reflection which modify the
apparent attenuation of radio waves reflected in the ionosphere are
discussed and methods used to minimize absorption measurement errors
due to these factors are given the experimental techniques used in
routine absorption measurements being described fully  detailed results
of measurements of ionospheric absorption made in south east england
in the period are being published separately
   /
7152
the investigation of ionospheric absorption by a new automatic method
part measurements on vertical incidence pulse signals  equipment
is described which automatically measures echo pulse amplitude and
produces records at minute intervals of the integral of all echo
pulse amplitudes received during each minute  the output of a modified
communications receiver blanked so as not to respond to the transmitter
pulse is fed to two gated amplifiers one of which selects the echo
signal and associated noise while the other deals with nose only
after integration for min the difference of the output voltages of
the integrators is applied to a pen recorder the integrators at the
same time being reset to zero  under good conditions with little
rapid fading the results obtained are in good agreement with results
noted by a skilled observer from a cro display of the transmitted
and echo pulses  wide differences are found under poor conditions
with rapid fading and the results furnished by the automatic equipment
are considered the more reliable
   /
7153
measurement of the electric field of the atmosphere by means of radioactive
probes
   /
7154
boys camera study of the air discharge and the flash to ground with
horizontal top
   /
7155
air discharges and the positive charge at the bottom of a thundercloud
   /
7156
the principle of a servo type mechanism requiring variable elements
   /
7157
the analysis of sampled data systems  the laplace and fourier transform
methods of analysis for sampled data systems are unified and extended
formulae representing the input output relations of such systems
in the frequency domain are derived
   /
7158
capacitance of selenium rectifiers  in ac measurements on se rectifiers
a temperature dependent phase shift between current and voltage is
produced  representation of the rectifier by an equivalent circuit
consisting of a resistor and parallel capacitor affords a satisfactory
explanation of this  discussion shows that a negative component of
capacitance is concerned which decreases with decreasing current
and with increasing frequency  the abnormal decrease of capacitance
with high reverse voltages observed by hoffmann of is in agreement
with this
   /
7159
a corona stabilizer eht supply for proportional counters
   /
7160
an electronic control device  description of a high precision voltage
regulator suitable for a rotary generator
   /
7161
cold cathode voltage stabilizer
   /
7162
internal alternating current resistance and reactance of conductors
of circular cross section  a numerical table is presented for simple
and accurate calculations for solid conductors and for thin or thick
tubes  proximity effect is neglected
   /
7163
vector representation in the time plane of electrical potential difference
current and power varying sinusoidally in time  the varying magnitudes
are considered according to a method originally used by fresnel
as the resultant of two imaginary vectors of equal and constant length
rotating at the same rate in opposite senses  the imaginary plane
containing these vectors is called the time plane  the impedances
of a circuit to the two vector components of a sinusoidally varying
current are defined and the method of representing power ie the product
of voltage and current is explained
   /
7164
a new pulse analyzer design  description with detailed circuit diagrams
of a single channel analyser which serves as the basic design for
multichannel analysers details being given of a channel analyser
positive pulses are accepted in the amplitude range plus the sum
of channel widths  the width and position of the channels can be
changed quickly without requiring recalibration  the design is simple
and relatively few valves are required
   /
7165
resistor temperature coefficients  tests were carried out on four
types of pyrolytic cr carbon film resistor and one type of metal
film resistor several samples of each type of different resistance
ratings being used  the results obtained for the temperature range
from to are shown graphically  the temperature coefficients of the
carbon film resistors are considerably lower than those of carbon
composition resistors  the coefficients are negative and much greater
than those of wire wound resistors though this is not the case for
borocarbon film resistors of et al
   /
7166
determination of voltage current and magnetic field distributions
together with the self capacitance inductance and hf resistance of
single layer coils  a theoretical investigation is made which is
applicable to coils of intermediate lengths  the number and magnitudes
of the harmonics are calculated and their effect on the self capacitance
is indicated  experimental results obtained by other workers support
the theoretical results
   /
7167
ferrite core inductors  design of inductors for communication equipment
is considered particularly from the point of view of the best use
of the properties of ferrites  advantages of ferrite compared with
metal cores for high frequency low power applications include higher
q values smaller volume and greater ease of adjustment
   /
7168
miniaturization of airborne filter chokes  a calculation charts is
given for chokes using mil laminations of si steel with square stack
use of the chart is illustrated by numerical examples
   /
7169
the power factor and capacitance of mica capacitors at low frequencies
experimental results confirm an empirical law of the form negative
and fractional for the power factor over the range at normal temperatures
they also confirm a relation between frequency power factor and
capacitance  power factors as high as have been found corresponding
to increases of nearly in capacitance over the values at higher frequencies
   /
7170
calculation of transient phenomena in electrically short networks
by means of fourier integrals  fourier integrals are applied to the
determination of the frequency spectra of periodic functions nonperiodic
functions including step functions  the results are used in discussion
of the distortion and initial conditions in networks to which an
impulse voltage is applied
   /
7171
design of practical linear networks with optimum signal noise ratios
a general method is described for the design of networks for which
the relation between the input and output signals is represented
by linear equations the frequency spectra of signal and noise being
assumed known  the application of the method of analysis in the design
of the optimum ionization chamber amplifier is illustrated and the
signal noise ratios attainable are compared with those for an rc
discrimination network and a delay line clipping circuit
   /
7172
applications of t networks  adaptation of paper r by lavagnino of
incorporating additional material  references
   /
7173
synthesis of transfer functions with poles restricted to the negative
real axis  a procedure for the synthesis of general rc transfer c
functions by means of unbalanced networks is described  the transfer
function need not be minimum phase but may have zeros anywhere in
the complex plane except on the positive real axis  use is made of
techniques described by guillemin of but the r problem is simplified
by use also of a network theorem due to adler enabling zero shifting
to be performed in two directions from within the tootal network
in an example worked out network elements are used whereas the guillemin
procedure would require
   /
7174
hall effect modulators and gyrators employing magnetic field independent
orientations in germanium  the application of the hall effect in
ge to the measurement of magnetic flux has been described previously
of pearson  further applications are now described to a product modulator
in which the current corresponding to one signal is passed through
the ge crystal while that corresponding to the other is used to produce
the magnetic field and a circuit element with non reciprocal transmission
properties or gyrator  in these applications a crystal orientation
is used for which the transverse magnetoresistance effects are zero
and the variation of the hall effect coefficient with flux up to
gauss is  the experimental determination of this orientation is described
   /
7175
the development of the electrical filter by k w wagners methods
wagners method of filter design which is based on consideration of
the filter as a ladder of matched reflection free sections icompared
with methods developed by zobel cauer and others it is concluded
that the principles laid down by wagner have lost none of their original
validity or usefulness
   /
7176
some designs of ladder filter  results obtained and methods of calculation
the principle of matching half sections and transforming impedances
in designing filters with a minimum number of components is illustrated
in two examples a narrow band band pass filter for and a filter with
a pass band centred on  formulae relating to the transformation of
t type quadripoles to type and vice versa and to various types of
quadripoles for impedance matching are collected in appendices
   /
7177
uhf band pass filters  a direct method is developed for designing
waveguide and coaxial line filters the characteristics of a cavity
filter are calculated  transverse obstacles comprising sets of thin
pins are shown to be better than diaphragms windows or single pins
from the point of view of losses and of manufacture and adjustment
cavities with q values of can easily be obtained using four pins
of diameter mm  design charts are given and several types of filter
are described and illustrated
   /
7178
admittance and transfer function of a multimesh resistance capacitance
filter network  the impedance function of an n mesh rc network is
expressed as a recurring continued fraction which is then resolved
into the quotient of two polynomials the admittance function being
the reciprocal of this quotient  the transfer function is then determined
the corresponding formulae for an n mesh cr network are derived
   /
7179
determination of the bandwidth of band pass filters for centimetre
waves  theory developed previously of is used to analyse the band
pass filter operation of an arbitrary arrangement of coupled cavity
resonators  a detailed treatment is given for the system comprising
two stagger tuned coupled resonators
   /
7180
spectrum equalization  the transfer characteristics of nearly all
forms of linear quadripoles can be equalized as regards both amplitude
and phase by adding to the response function its successive time
derivatives or integrals  the method may be applied to systems for
which the equivalent passive quadripole is not realizable eg a scanning
aperture  application of the method to servo control and television
is discussed
   /
7181
uhf magnetic attenuator  construction details and performance curves
are given for attenuators of the type previously described of
   /
7182
cut off attenuators for waveguide circuits  an equivalent circuit
analysis and report of measurements on short and long cut off sections
providing attenuation respectively less than and greater than db
beyond a certain length the reduction in attenuation due to reflections
at the junction is constant so that calibration measurements on long
sections are unnecessary
   /
7183
reliability of airborne electronic components  an analysis is made
of typical failures  reliability may be improved by modifications
to present day components and by substitution of less vulnerable
elements such as transistors and magnetic amplifiers
   /
7184
forced oscillations with nonlinear restoring force  both transient
and steady state oscillations are studied  the original differential
equation characterized by a nonlinear term is transformed to the
following first order differential equation following poincare and
bendixson the singularities and the integral curves of this equation
are discussed the former being correlated with the steady states
and the latter with the transient states of oscillation  the integral
curves yield the relation between the initial conditions and the
steady state solutions  fundamental and subharmonic oscillations
of order are investigated  the theoretical results are compared with
measurements made on a circuit containing a saturable iron core satisfactory
agreement is found
   /
7185
response of a series of resonant circuits to an applied emf whose
frequency is a linear function of time  a formula is derived for
the response of two or three rlc circuits in series to an emf of
unit amplitude represented by the expression where is half the frequency
sweep speed  the fluctuations in the response curve of a single circuit
are very much reduced when several circuits are connected in series
the increase of selectivity obtainable is investigated and frequency
sweep speeds permissible for one two and three circuits are determined
   /
7186
quasi degenerated modes in high dielectric cavities  a theoretical
and practical investigation is made of resonators comprising solid
circular cylinders composed of materials such as titanates having
permittivities of with or without metallization of the surfaces
as a consequence of the high permittivities cavity resonator techniques
can be used in the vhf range  for cylinders with the ends not metallized
quasi degenerate te modes can be realized  tuning can be effected
by inserting magnetic rods or by applying conductive disks externally
a design for an aerial developed from the te mode resonator comprises
a dielectric spiral coiled round a magnetic rod  practical disadvantages
inherent in these high permittivity dielectrics are indicated
   /
7187
the method of analytical signals  study of the synchronization of
amplitude limited oscillators  a method based on that of ville of
is used to determine the frequency limits within which synchronization
can be effected for a single tuned self limiting valve oscillator
the synchronization range is given by where is the difference between
the frequency of the synchronization voltage and the natural frequency
of the oscillator and e is the amplitude of the oscillation in the
steady state  the phase angle between the two voltages varies from
o for to  a system with wide synchronization range is discussed this
incorporates a phase discriminator whose output proportional to the
phase angle between synchronization and oscillator voltages is applied
to a reactance valve which in turn controls oscillator frequency
and
   /
7188
the use of admittance diagrams in oscillator analysis  a digest of
the available information on this technique
   /
7189
effect of background noise on the frequency of valve oscillators
ultimate accuracy of electronic clocks  fuller account of work noted
previously of april and back references
   /
7190
how to design bistable multivibrators  the design procedure described
is intended to ensure reliable operation in spite of deviations of
resistors from nominal values variations of supply voltage and deterioration
of valve cathode emission  formulae are given for determining
th appropriate values of coupling capacitance  triggering networks
for dealing with pulses of different amplitude and duration are shown
   /
7191
the effective bandwidth of video amplifiers
   /
7192
fluctuation noise in a microwave superregenerative amplifier  the
theory of operation of a superregenerative amplifier is reviewed
rices representation of noise current by a fourier series of and
back references is used in the expression for the amplifier output
a study is made of the particular conditions when a reflex klystron
is used in the amplifier expressions are derived for the noise figure
in terms f the klystron parameters  the overs overall noise figure
can be reduced by introducing beam current with its associated shot
noise during the quiescent interval
   /
7193
calculation of compensated wide band amplifiers  in german and french
loss of amplification with increasing frequency due to the output
capacitance of the amplifier valve is compensated by including inductance
in the circuit  three arrangements are discussed namely parallel
compensation series compensation and double compensation  abacs to
facilitate calculations are presented
   /
7194
dc amplifiers with negative feedback  methods are described for automatically
compensating the input impedance of current amplifiers or
the input admittance of voltage amplifiers  details are given of
the design and performance of several circuits for measurement purposes
in which very high input impedance with low capacitance is achieved
   /
7195
the wien bridge as a frequency determining element in selective amplifiers
analysis of the balance condition in a bridge circuit suppressing
the amplifier feedback voltage at a fixed frequency
   /
7196
coaxial cavity tuning element for uhf  the design is described of
a unit which can be used in television tuners and test instruments
for the band  the unit consists essentially of a metal cylinder with
an axial conductor having a gap at the centre to form a variable
capacitor for tuning  an accurately machined low loss dielectric
tube separates core and cylinder and serves as a close fitting guide
for the tuning plunger  applications of the unit in a signal generator
a frequency sweep generator a wavemeter and a grid dip meter are
described briefly
   /
7197
agc by means of miniature ntc resistors with heating element  the
negative temperature coefficient resistors are surrounded by the
heating element and enclosed in an evacuated glass tube the resistor
being included in the input circuit of an amplifier and the heating
element in the output circuit to obtain efficient agc  practical
circuit details are given and operating characteristics of the ntc
resistors are shown graphically
   /
7198
fundamental problems of hf and if amplifiers for tv reception part
feedback and practical considerations following on the theory  a
detailed discussion is presented of the effects in television amplifiers
of fedback via the cathode grid capacitance via the anode grid capacitance
via the anode cathode capacitance  the necessary formulae are
derived for an amplifying stage in which all three types of feedback
are present x so that their interactions can be investigated theoretically
the detailed discussion is however confined to systems in which
only one form of feedback is present  the theory is illustrated by
practical examples in amplifier design
   /
7199
filter design data for communication engineers  the book is intended
to supplement existing textbooks by providing charts tables and formulae
in convenient form it is concerned mainly with image parameter zobel
filters
   /
7200
the relativistic electromagnetic equations in a material medium
the general relativistic em equations for a material medium are expressed
in the form of a single four vector density equation  the field
tensor has six different complex components instead of three as in
the case of a free medium  the classical equations are obtained by
separating the real and imaginary parts
   /
7201
transistors theory and application part energy levels in transistor
electronics  a simplified exposition of some of the fundamentals
of quantum mechanics relevant to an understanding of transistor operation
   /
7202
some particular features of tropospheric propogation and their analogies
in wave mechanics
   /
7203
a precise determination of the charge of the electron from shot noise
the electron charge is calculated from the shot fluctuations of saturation
current in a specially constructed diode connected diode connected
across a tuned circuit resonant at  from precision measurements of
circuit parameters and the mean square value of shot noise the final
result obtained is
   /
7204
electron spin in semiconductors  theory is developed showing that
starting from equilibrium electron distribution expressed in terms
of absolute activity it is possible correctly to take account o electron
spin
   /
7205
high frequency discharges in gases  discussion of the main characteristics
and the mechanism of hf discharges indicating their practical
applications  references
   /
7206
field emission of electrons in discharges  substantial emission of
to electrons sec was obtained from cathodes of oxidized ni and w
with electric fields of about cm  by relating this emission to the
electric field by the fowler nordheim equation the effective work
function and emitting area of the source of the electrons for oxidized
ni and w were estimated as about and respectively  these results
are discussed
   /
7207
field electron emission and work function of crystal surfaces  the
field close to the surface is determined by measurements on models
in an electrolyte tank  formulae are derived for the density of the
field emission current  these are verified by field electron microscope
observations on w crystals
   /
7208
plasma in a magnetic field  the results obtained by considering plasma
from the electron motion point of view on the basis of kinetic theory
are discussed and reconciled
   /
7209
the relation between various types of plasma oscillation  a dispersion
relation is derived which applies to plasma oscillations electron
and ion oscillations of the larmor type and to magneto hydrodynamic
waves
   /
7210
definition of magnetic quantities  a critical examination is made
of the nomenclature hitherto used for magnetic quantities and proposals
are made for definitions which fit in with modern ideas without unnecessarily
disturbing established usage  precise definitions are given
of field strength polarization magnetization susceptibility and magnetizability
   /
7211
some magnetic properties of metals part magnetic behaviour of a cylindrical
system of electrons for all magnetic fields  the schrodinger
equation is solved for an electron moving in a uniform magnetic field
h the boundary of the system being a cylinder with its axis along
the direction of the field  two entirely different types of wave
function are possible one type leading to the small landau diamagnetism
of large systems the other to he larger diamagnetism of small systems
of april  taking account of the occupied states of both types the
steady contributions to the magnetic susceptibility are determined
for low high and intermediate temperatures
   /
7212
collective electron ferromagnetism a generalization of the treatment
and an analysis of experimental results  a term involving the fourth
power of the magnetization is introduced into stoners expression
for the energy associated with magnetization  if parameter values
are suitably chosen the properties of ni show a high degree of co
ordination and the magnetization temperature curves for ni co and
ni cu alloys can be interpreted simply
   /
7213
tentative theory of nonlinear electrodynamics part
   /
7214
production of radio waves by means of the tcherenkov effect  the
tcherenkov effect consists in the emission of em radiation by a particle
travelling through a medium with a velocity greater than that of
light  the essential results of frank and tamms theory of the effect
are quoted and references given to accounts of experimental verifications
of the theory using electrons and also protons  the possibility
of producing em waves in he range between the far infra red and uhf
by means of the effect in a narrow channel is discussed  it is concluded
that intense sources of em waves should result from the ue of powerful
beams consisting of packets of electrons  simple arrangements should
suffice for cm a and mm waves but difficulties will certainly be
experienced in the case of still shorter waves
   /
7215
a rigorous treatment of the diffraction of electro magnetic waves
by a slit  wave polarization components parallel to and perpendicular
to the slit are considered  an integral equation for the electric
field strength in the slit is found by the method of levine and schwinger
and of and an exact solution is obtained by developing the kernel
in a power series of the product of wave number and slit width  the
far field intensity and the transmission factor of the slit are calculated
and compared with the results of morse and rubenstein of  the
relation of the work to that of sommerfeld vorlesung uber theoretische
physik and of groschwitz and honl is discussed
   /
7216
the three dimensional problem of the diffraction of monochromatic
electromagnetic waves  the distribution of the em field in space
for a given distribution of field at a boundary surface is discussed
and conditions are established for the existence of a solution obtained
previously
   /
7217
the propagation of electromagnetic waves along a conical helix with
variable pitch  theoretical analysis  expressions are derived for
the reflection coefficient which may be practically zero and for
the impedance characteristics
   /
7218
galvanomagnetic effects in conductors  a review of the hall effect
and magnetoresistance in conductors with primary reference to metals
including ferromagnetic materials semiconductors are mentioned briefly
a physical survey of the whole field is first made in the second
part a more mathematical treatment is given of some of the major
problems involved  over references
   /
7219
hall effect  correction to paper noted in of march
   /
7220
magnetostriction  discussion of magnetostriction phenomena in single
crystals and in multicrystal materials  three effects are distinguished
form effect forced magnetostriction spontaneous linear magnetostriction
   /
7221
on the nature of the decay of a meteor trail  critical discussion
of the theories of kaiser and closs of and of greenhow of and
   /
7222
on the decay of radio echoes from meteor trails  discussion shows
that observed phenomena are explicable by the theories of kaiser
and closs of and of greenhow of  many points of disagreement between
observation and feinsteins theory of and above are noted
   /
7223
an experimental study of radio reflections from meteor trails  the
dependence of the echoes on the polarization of the incident wave
has been investigated and the existence of resonance scattering with
transverse polarization verified
   /
7224
thermal theories of the high intensity components of solar radio
frequency radiation  thermal theories of the origin of enhanced rf
radiation from regions which occasionally attain brightness temperatures
of deg k or more are discussed  none of the theories is found capable
of explaining the available observational data  it is concluded that
all three radiation components are generated by the ordered nonthermal
motion of electrons
   /
7225
a method of analysis of the directivity of solar radio emission from
sunspots
   /
7226
an estimate of the density and motion of solar material from observed
characteristics of solar radio outbursts  theory previously given
by feinstein and sen of is extended and applied to the observations
made in australia by wild and mccready of and by wild and of the
spectra o solar rf outbursts in the range of  the dispersion equation
equation involving the velocity of solar material erupting into a
static corona and the temperature and densities of the material and
of the corona enables the velocity of the material to be estimated
as about with a particle density of about with a particle density
of about
   /
7227
solar and terrestrial relationships  the general problem of the relation
between solar activity on the one hand and meteorological geomagnetic
and ionospheric phenomena on the othr is reviewed with special reference
to an account by scherhag of events which he interprets as being
related to an intense solar eruption on february  no such flare has
been reported  it is concluded that no clear evidence has yet been
given of a direct relation between solar phenomena and meteorological
effects
   /
7228
provisional sunspot numbers for october to december
   /
7229
the origin of magnetic fields in moving plasma  discussion indicates
that diffusion effects produce sufficiently large emfs in rotating
masses of ionized gas to account for the existence of solar and stellar
magnetic fields
   /
7230
effect of a large dielectric constant on ground wave propagation
   /
7231
cheltenham three hour range indices k for october to december
   /
7232
principal magnetic storms
   /
7233
international data on magnetic disturbances third quarter
   /
7234
the constants in the equation for atmospheric refractive index at
radio frequencies  the formula for scaled up refractivity n for air
is n where k are constants  the value proposed for k is derived from
recent reliable microwave and optical measurements of the refractive
index of dry air by barrell birnbaum et al of and essen and froome
o after adjustment to allow for an average amount of co in the composition
of the air  k is derived from two other constants obtained from
measurements of the dielectric constant of water vapour by birnbaum
and chatterjee of please note additional author  a table of values
of the constants used by various workers from to is given with comments
on discrepancies
   /
7235
the geographical and height distribution of the gradient of refractive
index  charts are presented of the february and august distributions
of the effective earths radius factor over the usa and of the vertical
distribution of refractive index gradient for warm temperate and
cold climates
   /
7236
long delay ionospheric echoes at  a report of results obtained at
pennsylvania state college ionosphere research laboratory using a
vertical incidence pulse transmitter with mw peak power  recordings
with a min exposure were made every half hour from to of the signals
received on an aerial system suitable for receiving circularly polarized
waves  three records obtained on november showed an isolated echo
corresponding to a reflection height of about km  the echo only appeared
on the records of the extraordinary wave  similar records were obtained
on two subsequent nights  possible explanations of these long delay
echoes are considered they may be due to reflections from a region
above the height of maximum ionization of the f region
   /
7237
on the comparative increases of the f and f ionizations from sunspot
minimum to sunspot maximum  the proportionate increase of ionization
from the epoch of sunspot minimum to sunspot maximum is not the same
for the f as for the f layer being of the order of for the former
and for the latter  assuming the f region to be due to ionization
of atomic oxygen an increase in temperature with height above the
f maximum an effective recombination coefficient decreasing rapidly
with height calculations are made for three different ionosphere
models the results being in each case in satisfactory agreement with
observations
   /
7238
effect of the solar eclipse of february on the ionosphere e layer
in equatorial africa  a report and discussion of observations of
e layer critical frequencies at bangui  the critical frequency of
the e layer decreased suddenly at the commencement of the eclipse
and was soon masked by that of the e layer  a graph of the observed
values of e shows that the effects of the eclipse were certainly
perceptible some to minutes before the first contact  a explanation
of the observed effects is based on the assumption of two solar regions
more active than the rest one in the corona near the western edge
of the disk the other near the eastern edge
   /
7239
electromagnetic effects in the ionosphere effects of crossed constant
magnetic and alternating electric fields  the effect of the crossed
fields on the distribution of the velocities of the free electrons
in an ionized gas is studied by means of the general equation of
boltzmann collisions between electrons being assumed negligible
the result obtained includes as particular cases those of dryvestyn
abstracts and of chapman and cowling the mathematical theory of nonuniform
gases and margenau
   /
7240
a study of winds in the ionosphere by radio methods  report of an
investigation made using mitras method of  the measurements were
made in ottawa and later in montreal and covered a period of a year
at a nominal height of km e layer the speed of the wind showed a
mean daily variation of approximately half day period and about amplitude
this variation can be explained on the basis of tidal oscillations
in the atmosphere  a variation corresponding to lunar atmospheric
tides has also been detected at this level  the winds in the f region
appear to increase in speed with increase of magnetic activity this
effect is not observed in the e region except during severe ionospheric
disturbances
   /
7241
a procedure for the determination of the vertical distribution of
the electron density in the ionosphere  comment on of february
   /
7242
an ionosphere recorder for low frequencies  based on hf recorder
design this beat frequency instrument covers the range and uses a
single loop aerial about long by ft high  sample records are reproduced
   /
7243
radio measurements and auroral electron densities  simultaneous recordings
of and echoes from auroral clouds were made at sakatoon  a large
number of echoes at were found for which there were no corresponding
echoes at and the echo amplitude ratio for the two frequencies varied
widely  critical reflections from small volumes of intense ionization
seem the most probable explanation of these observations where intense
auroral display are concerned  this would involve electron densities
of the order of cm in small volumes of the aurora for periods of
time short in comparison with the duration of the display
   /
7244
long duration echoes from aurora meteors and ionospheric back scatter
a report of radar echoes of unusual types observed in the course
of the ottawa meteor research programme  pulses with a peak power
of were radiated on a frequency of  some of the echoes were correlated
with visual observations of aurora  the extremely long duration min
to over min of some meteor echoes was probably caused by abnormal
ionospheric conditions  weak semipermanent echoes duration up to
or over hour are attributed to reflection at vertical or near vertical
incidence from irregularities in the lower ionosphere possibly the
same as those responsible for the long range propagation reported
by bailey et al
   /
7245
synthesis of servomechanisms at root locations
   /
7246
the cockcroft walton voltage multiplying circuit  the original circuit
is studied by considering it as a transmission line  losses are examined
and formulae are developed for the voltage efficiency for a given
size of capacitor and number of stages  two modifications to improve
voltage efficiency are discussed the first is the use of a loading
coil at the hv end of the line the other is the inclusion of inductors
in series with each of the capacitors
   /
7247
improved variable power supply  a modification of walkers circuit
of is described which provides direct voltage outputs from to  together
with heater supplies  inherent regulation is as good at as at
   /
7248
hermetically sealed magnetisum copper sulfide rectifiers  short note
on the construction methods used for this type of rectifier which
has an operating range from or higher
   /
7249
advanced developments in metallic rectifiers  discussion of improvements
relative to higher operating voltage smaller size operation at high
and at low temperatures and higher efficiency largely resulting from
requirements of the services  se rectifiers are particularly considered
   /
7250
new rectifier tube for extremely high power and voltage levels  this
valve has a th w filament with catenary configuration and a cylindrical
anode of ta coated with w powder  its characteristics are anode dissipation
rating peak current rating  maximum peak inverse voltage
   /
7251
microporous thermoplastic separators for lead acid batteries  brief
account of the manufacture and properties of porvic a pvc sheet material
a similar account is given in plastics april
   /
7252
addition agents for negative plates of lead acid storage batteries
part pure organic compounds  the best results were obtained with
carbohydrates and some of the homologous phenolic compounds
   /
7253
some applications of permanently magnetized ferrite magnetostrictive
resonators  for frequencies up to about magnetostrictive resonators
using ferrites are very much cheaper than crystal resonators  toroidal
magnetostrictive elements are discussed by applying the biasing and
driving fields in different directions different modes of vibration
are obtained  a definition is given of the coefficient of coupling
between driving coil and resonator this coefficient affording an
indication of the efficiency and being measurable with a q meter
applications of such devices as frequency control elements in oscillator
circuits and as components in various filter circuits are described
   /
7254
a method ensuring stability and equality of channel widths in a pulse
amplitude analyser  the method is basically that of wilkinson of
pulses of amplitudes between and are accepted and bandwidth stability
for hour working periods is within
   /
7255
the generalized transmission matrix stability criterion
   /
7256
generalization of the nyquist diagram method for nonlinear systems
methods previously explained of june are generalized to o cover the
case of oscillations represented by a nonlinear differential equation
of any order
   /
7257
the design of a peaking transformer  the basic principles of the
peaking transformer are outlined and the design of a transformer
to produce pulses of duration about from a input is discussed
   /
7258
helical winding slow wave structures in exponential line pulse transformer
a description is given of an experimental pulse transformer
with integral hydrogen thyratron pulse generator suitable for use
at the high impedance levels required in pulsed operation of magnetrons
the transformer has an outer cylindrical shell the inner conductor
consisting of a helix of constant diameter whose pitch decreases
gradually from the thyratron end  overall length is input impedance
and output impedance
   /
7259
steady state analysis of self saturating magnetic amplifiers based
on linear approximations of the magnetization curve  a method is
described for predicting the output currents of self saturating magnetic
amplifiers
   /
7260
the transient response of magnetic amplifiers  cases of negligible
commutation  discussion  full paper  summary noted in of
   /
7261
a saturable core reference source for use with magnetic amplifiers
   /
7262
terminology and equations for linear active four terminal networks
including transistors  a general system of terminology is developed
for linear active quadripoles both nodal and loop analysis being
presented  definitions are given of current voltage and power amplification
factors and the transformation equations are derived  the results
are applied to a number of transistor circuits the appropriate formulae
being tabulated  numerical examples are worked out
   /
7263
a printed circuit multiconductor plug
   /
7264
thermistor production  short illustrated account of the manufacture
of bead type and rod type thermistors from powdered mixtures of the
oxides of ni mn and cu
   /
7265
a new type of waveguide rotary switch  a high speed waveguide switch
is described which will connect two receivers or transmitters alternately
to one aerial and which is particularly suitable for centimetre
wavelengths  the performance of a model operating at mm was satisfactory
   /
7266
scale of ten counting unit using four double triodes  description
of a scale of circuit converted to scale of ten operation by means
of feedback from the fourth to the second stage ge crystals being
used for the feedback coupling and for that between the first and
second stage
   /
7267
a transistor reversible binary counter  see of
   /
7268
the properties of capacitors at high frequencies  the variations
with frequency of the capacitance and loss angle of capacitors are
deduced from the equivalent circuit the frequencies considered ranging
up to the television band  the self resonance frequencies of paper
mica and ceramic capacitors taking account of wire leads are shown
by curves  other curves show the variation of loss angle with frequency
   /
7269
on linear electrical networks  preliminary note of a method of analysis
in terms of network admittance
   /
7270
the calculation of carrier frequency transients  by using function
theory and the laplace transform method exact calculations are made
without introducing any assumptions regarding the phase response
of the transmission system  demodulation calculations by two methods
are considered  as an example of use of the preferred method a calculation
of the carrier frequency transients is made for the vestigial
sideband if amplifier described by zimmermann of a step voltage is
used for modulation  in appendices the practical application of the
residue theorem to transmission calculations is demonstrated and
a chart for plotting transients is presented
   /
7271
equivalent circuits using negative two pole elements  calculations
for three pole and multipole networks are simplified by substitution
of equivalents some of which have negative values
   /
7272
alent circuits consisting only of two pole elemeloci of complex impedance
and admittance functions
   /
7273
impedance matching with transformer sections  an equivalent circuit
for a transmission line transformer section is discussed which allows
considerable flexibility in design and enables and effects to be
easily taken into account
   /
7274
on the approximation problem in network synthesis  correction t paper
abstracted in of march
   /
7275
networks for which magnitude or phase angle of input impedance or
transfer admittance remains constant as load varies  the conditions
are determined that must be satisfied by a network at constant frequency
to obtain a particular variation of input impedance or transfer admittance
when the load changes in a specified way  results are tabulated
for ten special cases
   /
7276
the parameters of a four terminal network  the method of analysing
quadripoles in terms of image impedances and a propagation constant
is compared with the method based on the general circuit constants
the latter method which can conveniently be treated by matrix algebra
as described by guertler of is preferred  the relation between the
two sets of constants is examined and typical applications are illustrated
   /
7277
note on the iterated network and its application to differentiators
an alternative proof is given of the formula for a power of a matrix
recently given by pease of
   /
7278
use of locus diagrams to determine the equalizing action of bridged
t networks  numerical examples are used to show the method of determining
from the impedance diagram the variation with frequency of the
attenuation and phase coefficients of bridged t networks of different
types
   /
7279
how to design notch networks  curves are given which simplify the
design of capacitor shunt or resistor shunt bridged t networks and
of parallel t networks of the infinite attenuation rc type
   /
7280
synthesis of unbalanced rlc networks  each inductor of the network
is assumed to have associated series resistance  the method of synthesis
makes use of novel features including the breakdown of a hurwitz
polynomial into two others application of a network theorem to division
of the network into two parts and a method of zero shifting with
one pair of complex poles and being discussed in appendices  the
network realizes a minimum phase transfer function whose numerator
and denominator are of degree not higher than the third and fourth
respectively and whose poles and zeros may lie anywhere in the left
half of the complex frequency plane  extension of the procedure to
functions of higher degree is considered briefly
   /
7281
high characteristic impedance distributed constant delay lines for
fractional microsecond pulses  the delay lines described are pile
wound with wire of gauge about turns in on polystyrene rods previously
coated with silver paint slotted lengthwise at intervals and then
insulated with teflon tape prior to winding  a typical line in length
and in diameter has a characteristic impedance of a delay of and
an attenuation of the order of db  pulse rise and fall times are
about  response curves for pulses of and duration are give  characteristics
of and lines are tabulated
   /
7282
phase and group delay  expressions for phase and group delay are
obtained and the design of low pass delay networks is considered
with illustrative numerical examples
   /
7283
networks with maximally flat delay  comment on of
   /
7284
wieners theory of linear filtering  wieners theory of introduces
the concept of the optimum linear filter for use when signal and
noise occupy the same frequency band  this concept is examined without
attempting to follow the complex mathematics of the original  the
discussion is limited to the extreme cases of zero lag and infinite
lag filters which are appropriate respectively to telecommunication
and automatic control systems  a formula is derived for the transfer
characteristic of the optimum filter for an input signal having the
power spectrum with uniform random noise  for the zero lag case
the transfer characteristic is affected by consideration of phase
frequency variations for the infinite lag case it is not  for applications
in which delay can be tolerated the infinite lag filter has the
advantage of transmitting a much greater fraction of the input power
the applicability of optimum filters is discussed
   /
7285
improved components and materials for reliable electronic equipment
discussion of improvements in components and manufacturing techniques
resulting from a us signal corps research programme
   /
7286
the national radio components exhibition  review of annual exhibition
in paris with descriptions and illustrations of selected items  for
other accounts see toute la radio and television
   /
7287
circuitry packages for electronic computers  short description of
etched circuit mass produced units with projecting pin connections
the basic unit comprises a transformer coupled pulse amplifier using
a type miniature beam tetrode and a number of ge diodes  four variants
of the basic unit meet most computer circuit requirements  a new
computer including such units is under construction  tests jacks
facilitate location of defective components of individual units
   /
7288
electrical oscillations a physical approach to the phenomena  phenomena
occurring in oscillator circuits are explained in terms of modulation
products  for an input signal of given form an analysis is made of
the modulation products introduced by the curvature of the characteristic
of a nonlinear resistor the characteristic being represented to
any required degree of accuracy by a polynomial  the operation of
a negative resistance oscillator including a nonlinear resistor is
explained in terms of this analysis  in general the oscillation frequency
deviates slightly downwards from the resonance frequency associated
with the linear part of the circuit  forced oscillations and synchronization
are considered  a vector representation is developed for transient
behaviour and combined oscillations  for detailed mathematical discussion
see of
   /
7289
the response of a tuned circuit to a ramp function  a ramp function
is defined as one whose value increases linearly up to a certain
point and then remains constant  response curves are shown for a
parallel tuned lrc circuit subjected to a linearly increasing driving
force ramp voltages with various rise times  in each case curces
are given for circuit q values of and
   /
7290
three dimensional locus curves for describing the properties of electrical
circuits  in the jahnke emde tafeln hoherer funktionen of the
fresnel integral is shown by an isometric representation of a space
curve  prowse of has shown that the characteristics of an oscillatory
circuit can be similarly represented by a three dimensional locus
curve whose projections on the three reference planes give respectively
the usual circle diagram a resonance curve and an n shaped susceptance
diagram  wire models on similar lines are described which show the
relation between impedance and frequency or between admittance and
frequency for some simple and coupled circuits
   /
7291
a new quartz oscillator for the frequency range  a quartz oscillator
in the form of a tuning fork is described  each prong carries four
electrodes arranged according to the cut of the crystal and connected
so that on application of a voltage via the spring suspensions the
inner and outer halvex of each prong are stressed in opposite directions
in air the q factor is increasing to at a pressure of a few mm
hg  with thermostatic control the frequency variation can be kept
to within part in
   /
7292
electromagnetic field expansions in loss free cavities excited through
holes  the electromagnetic field in a loss free cavity excited through
holes cannot be completely expressed in terms of the short circuit
modes of the cavity satisfying the condition that the tangential
component of the electric field is zero on the boundary of the cavity
including the openings  for a complete expansion it is necessary
to add an irrotational magnetic field which contributes a term inversely
proportional to the frequency to the usual admittance matrix  if
the cavity is presumed to include a reasonable portion of the guides
feeding the openings this irrotational component becomes almost diagonal
   /
7293
the sawtooth derivator  the sawtooth derivator differs fundamentally
from the conventional type of timebase generator in that the require
waveform is derived from an arbitrary waveform which in its turn
is derived from the signal applied to the cro  in this way perfect
synchronization is obtained  various types of clipping and differentiating
circuits are discussed and a description is given with full circuit
details of practical equipment which functions entirely automatically
and covers the frequency range without any switching operations
   /
7294
oscillator with a or tbl transmitting valve  details are given of
the construction of a self excited oscillator using either a water
cooled or an air cooled high power transmitting valve  illustrations
are given of the special anode grid and cathode grid circuit arrangements
and of the method of coupling used for a water cooled dummy load
consisting of a shorted coaxial line  the power dissipated in the
load about is estimated from the rise in temperature and rate of
flow of the cooling water
   /
7295
a mode of oscillation of conventional triode valves  analysis shows
that if certain conditions are satisfied uhf oscillations are possible
in a triode valve designed for lower frequencies  this was verified
for a telefunken type triode which is designed to oscillate on wavelengths
down to about cm  the valve has two grid and two anode terminals
and to these a resonant wire system was attached with a resistor
and milliammeter connected between grid and earth  with an anode
voltage of good oscillations on a wavelength of cm were obtained
the mean oscillatory voltage on the grid being about and on the anode
about  the calculated wavelength was about cm
   /
7296
stability in negative feedback time bases  the term double stroking
is applied to a condition in which alternate scanning strokes are
dissimilar this phenomenon is liable to occur during starting and
may continue indefinitely in any time base where the initiation of
flyback depends on the conditions existing at the end of the scan
and the flyback is maintained linear  the process is examined in
detail for some typical circuits
   /
7297
interesting nonlinear effects  experiments show that simple circuits
comprising ordinary electric lamps together with iron core transformer
coils and capacitors have properties similar to some multivibrators
and ring circuits  applications to switching counting and delaying
are indicated
   /
7298
the gas filled triode as pulse amplifier valve  an experimental investigation
is reported  using a special circuit to avoid permanent ignition
a recovery time of can be attained with a he filled type valve  for
applied pulses of duration the operating threshold value of input
voltage may be as low as for shorter pulses the threshold is a few
volts  as pulse width and height decreases the build up time for
the discharge increases and the time delay of the amplified pulse
is increased  the gas triode is thus only appropriat  in the output
stage of a pulse amplifier
   /
7299
video amplifiers with extremely large bandwidth  practical designs
of a cascade amplifier and one with distributed amplification are
illustrated  comparison of the tw types shows certain advantages
of the cascade type
   /
7300
a direct amplifier for voltages down to having low internal resistance
the low voltage threshold is zchived by using a crystal contact relay
and tesla transformer in the input circuit to convert the dc to ac
for amplification
   /
7301
a survey of the limits in dc amplification  the effect of a change
of the cathode temperature of planar dioe and triodes is calculated
and the possibility of compensating this temperature effect is discussed
the effect of anode voltage changes is analysed and some new compensating
circuits are described which enable dynamic and in phase balance
to be obtained simultaneously with a single adjustment  for all balanced
circuits the requirements as regards stability of the supply or auxiliary
voltage are found to be nearly the same  changes of valve constants
with time are discussed  investigation showed that the poorly defined
position of the heater in the cathode sleeve of some valves seriously
limited their stability
   /
7302
harmonic distortion and negative feedback  an analysis is made which
takes account of the production of harmonics of order higher than
the second by the negative feedback process  the usual formula for
the reduction of distortion by application of negative feedback is
accurate if the slope of the amplifier output voltage input voltage
curve does not vary appreciably over the working range  if a valve
with a sharp cut off is used and the input voltage is greater than
the cut off value no reduction of distortion can be effected by negative
feedback
   /
7303
noise in transistor amplifiers
   /
7304
filter design data for communication engineers  a design procedure
is outlined which permits rapid computation of the element values
of the optimum zobel filter having a given attenuation characteristic
   /
7305
the acousto electric effect  theoretical calculations indicate that
an electric current should be generated in a crystal by the passage
through it of an acoustic wave  in a metal the electrons concerned
are at the fermi level in an n type semi conductor they are in the
conduction band  calculations for na and for n type ge indicate that
the predicted effect should be measurable
   /
7306
initial rise of brightness of electroluminescent substances under
the action of an alternating field  observed phenomena can be explained
on the assumption of excitation of luminescence centres by conduction
band electrons that have acquired sufficient energy  these electrons
reach the conduction band from electron donor levels a few tenths
of an electron volt below and are then accelerated
   /
7307
influence of electric fields on luminescence  brief report of an
investigation of the luminescence of a zns cu phosphor excited by
near ultraviolet radiation and subjected to alternating electric
fields at frequencies up to  the procedure used was similar to that
of destriau of
   /
7308
effect of an electric field on a continuously excited phosphor  when
an alternating electric field is applied to a zns cu phosphor excited
to steady state luminescence a momentary increase of luminescence
is observed with a subsequent drop and a slow change to a new steady
state a periodic intensity ripple of double the field frequency e
being superposed  switching off the field generally results in a
new momentary intensity with subsequent gradual return to the initial
value  these effects are explained on the basis of theory given by
randall and wilkins of
   /
7309
vector potential derivation from scalar potentials  digest of paper
presented at aiee district meeting may  definitions are given of
vector potential it is shown that vector potentials can be derived
from the scalar potentials included in the tables of greens functions
below  results are given for the field due to a thin rectangular
sheet of magnetic material or a rectangular coil
   /
7310
calculation of contact potentials  a formula is derived for the contact
potential between two metals from consideration of ermi energy levels
and surface thermal electron flux
   /
7311
contact phenomena  continuation of investigation noted in above
if the two barrier layers have the same transparency the usual formula
for contact potential is found in terms of the constants of the dunshma
richardson equation if the two barrier layers have different transparencies
a correction term comes into play  analysis indicates that by
making sufficiently accurate measurements of contact potential it
should be possible to separate emission constant variation due to
variation due to variation of work function with temperature from
that due to barrier transparency
   /
7312
electrical fluctuation phenomena  the possibility is discussed that
fluctuation phenomena in insulting materials may have their origin
in recombination fluctuations of the freed electrons with their positive
residual charges the recombination fluctuations being related to
the statistical density fluctuations of the solid and being amplified
by the mechanism of electronic conduction
   /
7313
transistors theory and applications part physical properties of electrons
in solids  presents a concept of the electron that fits with generally
accepted explanations of phenomena in semi conductor materials
that are responsible for transistor action
   /
7314
dependence of direct sparkover voltage of gaps on d humidity and
time  a systematic investigation of humidity and time effects on
the breakdown voltage for gaps using spheres cm in diameter standard
rods in square section with square edges  results are shown graphically
and discussed
   /
7315
general expression for the conductivity tensor and for the dielectric
tensor in an ionized medium  various applications hall effect and
generalization of langevins formula for mobility  a calculation to
a first order of approximation is made of the distribution function
for electrons in an ionized gas exposed to crossed magnetic and electric
fields  the rate of diffusion of the electrons is deduced and expressions
are derived for the conductivity and dielectric tensors  in a
later paper the formulae obtained are to be discussed and compared
with those established by huxley of
   /
7316
washington conference on magnetism  september  the papers presented
at the conference are given in full with reports of the discussions
   /
7317
the external magnetic field of a single thick semi infinite parallel
plate terminated by a convex semicircular cylinder
   /
7318
general solutions of maxwells equations  expressions are derived
which are sufficiently general to cover the case of charges or currents
within the volume considered
   /
7319
diffraction by a thick semi infinite plate  a method of analysis
based on that previously described of february is applied to the
problem of the diffraction of a two dimensional plane harmonic wave
by a semi infinite perfectly conducting plate of thickness d  expressions
are obtained for the distant field when d has any value and the
effects at the boundary of the shadow are deduced  extension of the
theory to the problem of diffraction by a thick plate of finite length
is briefly discussed  the theory is also extended to incident scalar
waves whose direction of propagation does not lie in the plane perpendicular
to the plate
   /
7320
the diffraction of a dipole field by a perfectly conducting half
plane  a method of analysis is developed which is valid for any orientation
of the dipole the dipole field is resolved into plane waves
whose diffraction can be studied independently  the particular case
of an electric dipole with its axis normal to the half plane is investigated
   /
7321
absorption in an electron gas mixture  the influence of the collision
damping on the polarization of an electron gas mixture subjected
to an alternating electric field is calculated using the kinetic
theory of gases and assuming the simplest type of elastic collision
the nonlinear effect of the absorption is estimated to a first approximation
this nonlinearity is significant for long waves propagated
in the ionosphere
   /
7322
microwave absorption spectrum of nd  the frequencies of the main
jk sequence of inversion lines in the nd absorption spectrum between
and measured in a coaxial type of stark cell are tabulated together
with values calculated from an ny type formula
   /
7323
the faraday effect in conductors and semiconductors  analysis on
classical lines is pe presented for the effect on a plane polarized
plane em wave of an applied constant magnetic field in the direction
of propagation  a formula for the rotation of the plane of polarization
is derived which may possibly be checked experimentally
   /
7324
the influence of magnetic impulses on the kinetic energy of electrons
analysis is presented showing that magnetic impulses such as those
caused by em waves with discontinuities in the magnetic components
may produce variation of the kinetic energy of electrons z and may
contribute to the destruction of atomic structures
   /
7325
surface investigation of metals and nonmetals with exo and photoelectrons
the term exo electrons is applied to electrons emitted from a
surface under excitation by light of sufficiently short wavelength
an exothermic process being involved  a description is given of the
special geiger type needle counter used in th investigation the light
source with plexiglas lenses being built into the counter  results
obtained are shown graphically and discussed they include curves
showing the decay of exo and photo electron emission from energy
treated pt stretched al and gypsum and temperature variation of exo
electron emission from gyprsum quartz and quinine sulphate subjected
to various types of irradiation
   /
7326
calculation of the capacitance of a circular annulus by the method
of subareas  an approximation method is described and applied to
the determination of the capacitance and charge distribution of a
circular annulus and of a circular disk  the fourth approximations
for the capacitance are in good agreement with the known exact values
   /
7327
the magnetic field strength in sunspots  brief discussion of the
validity of formulae developed by various investigators
   /
7328
the sunspot number series  because of the lack of a truly periodic
term in the sunspot number series predictions have so far been made
on an empirical basis  a more satisfactory representation is obtained
by plotting the numbers with reversed sign for alternative year periods
to give a year cycle with practically zero mean value  a significant
degree of correlation is found between the slopes of adjacent flanks
of the successive year cycles
   /
7329
mean magnetic field and secular variation in adelie land
   /
7330
the lower e and d region of the ionosphere as deduced from long radio
wave measurements  an ionosphere model is proposed which is in reasonable
agreement with experimental data  during the day this locates
the reflection region in the tail of the d layer around km height
the ionosphere winds region in the nose of the layer centred on km
and a region of minimum ionization density between the d and e layers
at about km with electron density of about electrons cm
   /
7331
the longitude effect in the f region  see also
   /
7332
ionospheric storms and the geomagnetic anomaly in the f layer  graphs
are shown of hourly values of the ratio of critical frequency on
magnetically disturbed days to that on quiet days for wakkanai during
the winter hourly values of the ratio of critical frequency at ottawa
to that at wakkanai during the winter  the shape of the graphs is
similar indicating that the geomagnetic distortion anomaly in the
f layer is such that it causes a minimum of critical frequency in
the forenoon and a maximum in the afternoon  for huancayo the principal
anomaly is the abnormal maintenance of high f values after sunset
   /
7333
travelling disturbances in the ionosphere  diurnal variation of direction
since the publication of previous papers of observations of greater
accuracy and extending over a greater part of the day have provided
definite evidence of diurnal variation in the direction of horizontal
movement  this is most marked in the month of june  a graph is given
which shows the median values of all directions observed for each
hourly interval for all days of june in and  a similar trend is noted
in all three years the direction of movement changing from about
at to at  recent night observations suggest that there is consistently
an e component of movement at night in contrast with the consistent
we component in the daytime
   /
7334
moving clouds of ionisation in region e of the ionosphere  during
investigations of the phase path of radio waves returned from the
e layer of some echoes were observed which came from equivalent heights
rather less than that of the e layer  analysis supports the interpretation
that the echoes came from ionization clouds moving with constant
velocity in a horizontal direction  histograms show tht the velocities
ranged between and that the most probable duration was and the most
probable height km  echoes can apparently be detected only from clouds
la lying within a cone of semi angle from the observing point the
average horizontal dimension of the clouds being about m
   /
7335
the heights of ionospheric winds as measured at long radio wavelengths
the winds region is considered as constituting a screen capable of
altering the phase and amplitude of a radio wave passing through
it  the field pattern at the ground is assumed to be such that information
on the phase change and absorption experienced by a wave passing
through the screen can be obtained from it  it is also assumed that
only the ordinary wave is observed and that the region concerned
is of the wkb type with these assumptions theory is is developed
which when applied to experimental data for signals gives the winds
region height as km during the day and km at night
   /
7336
conductivity of the ionosphere and geomagnetic tides  the results
of various investigations are summarized and discussed with particular
reference to effects observed near the geomagnetic equator
   /
7337
the investigation of ionospheric absorption by a new automatic method
part measurements on oblique incidence broadcast signals  apparatus
similar to that described in part of june is used for recording the
strength of a signal received from a distant transmitter by reflection
from the ionosphere  comparison of the vertical incidence records
with simultaneously obtained oblique incidence records is expected
to facilitate the investigation of winds in the ionosphere
   /
7338
scattering and attenuation by non spherical atmospheric particles
gans theory of em scattering and absorption by ellipsoids is applied
to atmospheric particles  if these have preferred orientations the
amount of back scattered energy depends on particle shape and on
orientation of the particle relative to the incident beam  the effect
is negligible in the case of snow  if the particles have random orientations
the observed scattering is independent of aerial orientation
but greater for ellipsoidal shape and for water particles than for
ice  these theoretical considerations account well for known melting
band phenomena
   /
7339
multiple bursts of signal in long distance very high frequency propagation
   /
7340
a phase plane approach to the compensation of saturating servomechanisms
   /
7341
network synthesis by graphical methods for ac servomechanisms  see
of
   /
7342
calculation of the attenuation in filtered oscillators  a hypothesis
previously used is not required in defining the dynamic characteristics
of a control system  a particular class of nonlinear servo mechanisms
is investigated and stability criteria are discussed  see also of
april of may
   /
7343
some design criteria for automatic controls  the design of control
systems to give optimum response is discussed in terms of the area
between the graphical representation of a step disturbance and th
control response curve  this area and a weighted control area can
be calculated directly from th system parameters and enable the necessary
control sensitivies to be determined for optimum response
   /
7344
rotary amplifiers in servomechanisms  the rotary amplifier consists
of a dc generator driven at constant speed  the properties of this
machine as an amplifier are discussed  use of this amplifier as power
stage for a valve amplifier in servomechanisms is described
   /
7345
effects of carrier shifts on derivative networks for ac servomechanisms
   /
7346
a note on the design of conditionally stable feedback systems  formulae
are presented which relate parameters of the loop transfer function
of a conditionally stable system to the relative stability of the
system transfer function  the condition is determined for which the
system bandwidth is a minimum when the loop transfer function is
required to have a specified value at a particular frequency
   /
7347
power supplies for transmitters  present day equipment used for supplying
power to small or large installations is described
   /
7348
differential analyzer study of harmonic power generation with nonlinear
impedance element
   /
7349
a gas tube inverter with the supply voltage below the breakdown voltage
investigation of the operating characteristics of simple circuits
using gas discharge tubes working with direct voltages down to about
   /
7350
development of volt selenium rectifier plates  forward and reverse
characteristics are given for recently developed se rectifiers in
a bridge circuit  results of a life test shoed a voltage drop of
about  the use of such plates effects a great reduction in weight
compared with post war plates
   /
7351
voltage stabilization  review paper with references  results of the
latest work on glow discharge tubes are reported
   /
7352
a new electrostatic influence machine  description of the principles
of operation the construction and performance of a rotary machine
operating at atmospheric pressure and giving voltages up to
   /
7353
diffraction patterns for solid delay lines  solutions of the vector
equation of equilibrium for an isotropic solid are presented for
the special case of loss free sine waves  examples are considered
in which the distribution of a single stress component is selected
to simulate the stress produced by a high frequency quartz crystal
   /
7354
extension of the concept of the time constant  examples of the application
of a general expression for the time constant are illustrated
in cases where the function is not exponential
   /
7355
geometrical transformation of impedance diagrams  the limited impedance
range of the normal circle diagram representation of impedances is
noted  a second type of circle diagram can be constructed in which
all possible impedance values satisfying the required conditions
lie within the unit circle its construction by means of riemanns
number sphere is required
   /
7356
consideration of some factors concerning the use of audio transformers
the effect on the frequency response of using source or load impedances
different from the rated values is discussed  methods of reducing
distortion due to nonlinear core characteristics and o eliminating
noise due to various causes are indicated  methods of matching several
impedances to a single one simultaneously are shown
   /
7357
the input impedance and transimpedance of if transformers  formulae
are derived for the conventional if transformer consisting f two
coupled circuits tuned to the same frequency  the relation between
transimpedance and input impedance variations and the form of the
frequency response curve are investigated  the method of constructing
polar diagrams is explained and diagrams are shown for the two impedances
for various values of the parameters their usefulness in the study
of feedback phenomena particularly feedback from valve anode to grid
is indicated
   /
7358
dynamic characteristics of transductors or magnetic amplifiers  review
of the physical characteristics of transductors with low resistance
control circuits and of the self excitation type
   /
7359
the figure of merit of magnetic amplifiers
   /
7360
magnetic amplifier with reset control
   /
7361
transistor negative impedance converters  improved converters of
the general type described by merrill of are obtained by using transistor
circuits in place of th original valve circuits  the characteristics
obtained are highly stable  various practical circuits are illustrated
and discussed and application in telephone repeaters are described
   /
7362
symmetrical properties of transistors and their applications  symmetry
of one kind is found in the complementary characteristics of the
npn and pnp types of junction transistor by using these two types
in combination reduction of the number of components and other circuit
simplifications can be achieved particularly in single ended push
pull amplifiers  symmetry f a second kind can be found in single
transistors and is evidenced by interchangeability as regards operation
of emitter and collector use is made of this property in switching
circuits eg for clamping and modulation and for a high efficiency
television deflection circuit
   /
7363
on the magnetization of toroids with one and two air gaps  a method
is proposed for calculating the leakage coefficient in the case of
a toroid with one large air gap and an experimental formula is derived
for determining the average leakage coefficient for the cases of
toroids with one air gap and with two diametrically opposite air
gaps
   /
7364
the second fundamental theorem of electrical networks  an independent
proof is given of a theorem which states for the norton nodal representation
the relations previously proved by ingram and cramlet of for
the thevenin mesh representation  the nodal equations of kron as
given by le corbeiller of are deduced by a method similar to that
of synge  the relation between the nodal and mesh theorems is discussed
   /
7365
network transformations  a method of finding an equivalent for a
given network is outlined a table of equivalent networks is presented
and examples of the use of the method are given
   /
7366
the solution of passive electrical networks by means of mathematical
trees  a new method of solution for network problems is based on
the properties of certain basic types of network termed trees and
trees  linkage functions defined in terms of sets of trees and trees
obey laws analogous to those of kirchhoff so that relations involving
voltages and currents can be expressed in terms of linkages  results
of the method are given in terms of admittances
   /
7367
design procedures for pi network antenna couplers  discussion on
paper noted in
   /
7368
reciprocal ladder networks  the transfer impedance of a system comprising
generator and load with ladder network interposed is unchanged
if instead of the original network a reciprocal network is connected
in reverse  the reciprocal network is derived from the original one
by replacing series impedances by shunt impedance and vice versa
the product of the original and new impedances being in each case
equal to the product of the generator and load impedances
   /
7369
reactive t r sections resolvable into two matched half sections
means are indicated for determining whether the resolution into half
sections with matched terminal impedances is possible
   /
7370
study of an electronic antiresonant circuit  theory is given of a
circuit which can either be used as a low pass filter or as an antiresonant
circuit  the operation of the circuit in the steady state in
response to an applied sinusoidal voltage and in the transient regime
in response to a unit step voltage is analysed  as an antiresonant
circuit it is more selective than a double t rc circuit  its characteristics
can be varied within wide limits and the values of the components
can easily be calculated from the characteristics specified  its
high selectivity independent of the cut off frequency makes it particularly
suitable for use at very low frequencies
   /
7371
resistive bidirectional coupler  a resistive t network is discussed
which when inserted between a source and a load acts as a bidirectional
coupler providing voltages proportional respectively to the incident
and reflected waves  the arrangement is applicable to measurement
purposes and is used eg in the wattmeter described by ryder and mcvay
   /
7372
resistance capacitance networks in amplifier design  two types of
rc network are distinguished the first of which includes all networks
with a simple series or shunt capacitor  this type only is considered
frequency and phase characteristics are derived and reduced to simple
graphical form  impedance matching and loading effects are discussed
typical equalizer and tone control circuits are examined
   /
7373
attenuation equalizers  the performance of various commonly used
equalizer networks is discussed and a chart method of computing their
insertion loss is presented
   /
7374
minimum inductor or capacitor filters  known methods are surveyed
and some new methods developed for designing equivalent filter networks
having fewer inductors or capacitors than a given network  the particular
transformation appropriate in a given case depends on whether
the given filter is an image parameter type which can be split into
separate m derived sections or is of a more general character  the
methods presented are based on the values of the network elements
without reference to impedance frequency functions of the network
as a whole  two practical examples of application of the methods
to band pass filters are treated in detail
   /
7375
the effects of terminations and dissipation on the insertion loss
of some simple ladder filters  by using special terminations the
selectivity of these filters can be improved and elements with relatively
low values of q can be used  insertion loss curves indicating
the combined effects of the terminations and of dissipation in the
filter elements are presented in a form applicable to low pass high
pass and band pass filters of several types
   /
7376
theory of antimetrical lattice filters  the theory o a class of lattice
filters with inverse image impedances is a counterpart of that for
symmetrical filters  these filters comprise two reactances and their
inverses the frequencies at which the modulus of the reactances is
equal to the he characteristic impedance correspond to the poles
and zeros of the reactances in the symmetrical case  calculations
relative to the construction of such filters are explained and typical
examples are described  a high ratio impedance transformation is
attainable with narrow band circuits  see also of
   /
7377
optimum nonlinear filters  theory of optimum nonlinear filter is
based on the consideration of a sequence of classes of nonlinear
filters n such that each class in the sequence includes all the preceding
classes and also includes the class of linear filters  the characteristic
function of the optimum filter within the class n is found
to satisfy a linear integral equation of od order  a detailed treatment
of optimum filters of class n is given and methods of approximate
realization of such filters in the form of nonlinear delay line filters
and power series filters are indicated  the results are extended
to the case of nonstationary time series
   /
7378
construction and calibration of an inductive attenuator  a hf attenuator
is described which makes use of the properties of a waveguide at
d frequencies far below cut off  for a frequency of the attenuation
varies linearly to within between and db with the distance between
the source and the output coil  the attenuation can be calculated
from the physical dimensions only
   /
7379
novel valve circuits  a review of valve circuits operated under unusual
conditions in respect of bias anode and screen voltages and of input
and coupling arrangements as in pulse squaring and gating circuits
and electrometer applications
   /
7380
a note on moving poles in nonlinear oscillating systems  since poles
of the complex immittance of a linear system represent the decrements
and frequencies of rotating phasors in the linear time domain it
is suggested that a nonlinear system might be represented by moving
poles whose instantaneous decrements and frequencies are associated
with phasors rotating in the nonlinear of time distorted phase space
this idea is applied to the analysis of a class of nonlinear oscillation
generators of the second order which is described by the differential
equation o
   /
7381
a second contribution to the solution of the rukop problem  re examination
of the problem of the dynatron driven series circuit and the
arc driven parallel circuit abstracts  nyquists stability criterion
is applied to the equivalent circuit and the necessary and sufficient
conditions for excitation of oscillations are determined
   /
7382
compensation of the temperature effect in lc circuits by means of
negative coefficient capacitors  compensation at a given frequency
is obtained by connecting in parallel with a variable capacitor a
series arrangement of a fixed negative coefficient capacitor and
a variable capacitor  the experimental method of adjustment is described
frequency variation with temperature for uncompensated settings is
studied
   /
7383
more on the rc oscillator
   /
7384
the frequency spectrum of a pulled oscillator  the conclusions reached
by buchanan o are presented in a simpler and more precise form
   /
7385
blocking oscillators  the use of blocking oscillators as generators
of voltage or current pulses or of repetitive sawtooth voltage or
current waveforms is examined in some detail with a description of
thd mode of operation of the vz various circuits considered and discussion
of the factors affecting their practical design
   /
7386
the impulse governed oscillator a system for frequency stabilization
   /
7387
improved lock in amplifier  a stable sinusoidal voltage drives a
square wave generator whose output is applied to the anodes of a
pair of i diodes in phase opposition  the signal is applied to the
anodes of a pair of diodes in phase opposition  the signal is applied
to the diode cathodes in equal phase  the dc output voltage developed
between the two cathodes is directly proportional to the signal and
is largely independent of the input noise level the value of the
stable voltage and the valve parameters
   /
7388
constant current operation of power amplifiers  a class a amplifier
is discussed which is designed to be nearly independent of variations
in valve characteristics  cathode follower drivers are used together
with balanced feedback and a x separate feedback phase inverter
see also of june
   /
7389
distortion in class a push pull amplifiers  the distortion is expressed
in terms of the derivatives of the anode grid characteristic at the
operating point  the effect of the cathode resistance is to increase
the distortion as compared with the effect due to the load resistance
alone
   /
7390
degenerative pentode equivalent circuit  analysis and discussion
based on two forms of equivalent circuit of a pentode arrangement
with feedback via cathode lead impedance
   /
7391
distributed amplifier theory  matrix algebra is used to analyse operating
conditions in the anode line  the manner in which the amplifier
gain depends on grid and anode line terminations and propagation
constants number of valves and grid driving voltage is indicated
experimental results obtained with a six valve amplifier provide
general confirmation for the theory
   /
7392
analysis of a single ended push pull audio amplifier  analysis is
given for the circuit described by peterson and sinclair of  linear
valve characteristics and small signals are assumed  some experimental
results are reported
   /
7393
bypass and decoupling circuits in audio design  the amplifier equation
is put into a form which expresses the gain for ideal conditions
of perfect bypassing and no reactive elements with separate terms
taking account of the actual reactive effects  these terms are evaluated
for the limiting conditions at the low and high ends of the frequency
band and the real and imaginary parts are separated  design of triode
and pentode circuits is considered
   /
7394
audio frequency input circuits  careful design of input circuits
is important especially when the input level is low  fundamental
factors considered include signal noise ratio of the source optimum
input impedance for resistive and reactive generators noise in the
amplifier valve input transformer and connecting cable characteristics
   /
7395
a differential input stage for low frequency amplifiers  an ac coupled
differential input stage is described in which the ratio of in phase
to anti phase gain ie the transmission factor is theoretically infinite
in an actual circuit the measured value of the transmission factor
was at an in phase signal level of rms  the frequency range of is
adequate for most applications
   /
7396
cathode drift compensation in dc amplifiers  the miller circuit has
been found effective in compensating against cathode drift but it
has been assumed necessary to use a load resistance large enough
to make the anode current of the output valve small compared with
that of the other  simple analysis is presented to show that this
limitation is unnecessary an improvement of the circuit based on
this analysis is suggested
   /
7397
vacuum tube oscillators  intended for senior and graduate students
as well as for practising electrical engineers the subject is treated
mainly from the point of view of design
   /
7398
successive differentiation of experimental curves and method of smoothing
   /
7399
mathematical aspects of the quantum theory of fields part fields
modified by linear homogeneous forces  of may
   /
7400
diracs function and its utilization in mathematical physics
   /
7401
some exact solutions in nonlinear oscillations  a rigorous analysis
is made of forced oscillation mechanical or electrical systems for
certain cases which are specified by the condition that the condition
that the forced oscillation has a waveform similar to that of the
external force  the stability conditions are derived from hills equation
which can be solved exactly for the present cases
   /
7402
one to two millimeter wave spectroscopy  spectral lines have been
measured at many positions between mm and mm wavelength using similar
technique to that previously described of johnson et al  construction
details of the new multiplier and detector used will be given elsewhere
   /
7403
the mechanism of phosphorescence in crystal phosphors  a summary
of the results of the investigations described elsewhere in greater
detail of june
   /
7404
infinite matrices associated with diffraction by an aperture  the
results obtained by levine and of are discussed and it is shown that
the algebraic properties of the matrix used are such as to permit
determination not only of the transmission coefficient but also of
the distribution of field across the aperture
   /
7405
a note on the application of schwingers variational principle to
diracs equation of the electron
   /
7406
transistors theory and application part transistor action in germanium
and silicon  a simple account of the physical structure and properties
of ge and si crystals  part of august
   /
7407
investigation of the potential barrier between two electrodes of
the same metal with different applied potentials  a theoretical investigation
of the barrier transparency and tunnel effect  analysis leads
to formulae which for limiting cases give the known results corresponding
to a rectangular or triangular type of barrier
   /
7408
some properties of potential barriers  matrices used in defining
the wave function at the junction between different media are shown
to be applicable for calculations relating to potential barriers of
various forms
   /
7409
the electrical breakdown of gases in nonuniform fields at low pressure
breakdown voltages between coaxial cylinders were investigated for
air hr h and he  the results obtained support the view that the same
primary and secondary ionization processes are involved as for uniform
fields
   /
7410
the reflection coefficient of positive lithium ions striking a metal
surface and the energy spectrum of the secondary electrons  results
obtained for targets of duralumin and nickel are shown graphically
see also of february for which the number should be
   /
7411
a survey of present knowledge of thermionic emitters
   /
7412
the zero point susceptibility of a linear antiferromagnetic atomic
chain
   /
7413
operating of the penning gauge  experiments were made to check results
reported by laffineur and pecker on the emission of hf waves from
a gas discharge  a receiver tunable over the band and fixed tuned
receivers for and cm were used  no radiation was detected on the
last two wavelengths on the other wavelengths continuous spectra
were observed with a fairly sharp peak at a frequency less than half
the gyromagnetic frequency  the effect of a component of electric
field normal to the magnetic field is discussed
   /
7414
longitudinal magneto hydrodynamic waves  alfvens theory indicates
that the velocity of sound waves in a conducting fluid will be changed
by application of a strong magnetic field  theory of this effect
is presented for a fluid with finite conductivity and is applied
to predict effects that should be obtained in propagation of sound
in hg in a very strong field in sea water under influence of the
geomagnetic field
   /
7415
generalized magneto hydrodynamic formulae  the formulae of magneto
hydro dynamic theory are extended by the simpler methods of magneto
ionic theory in which mean velocities and forces are used and nonlinearities
are avoided by perturbation treatment  the results are applied
to the case of plane wave propagation in the direction of a primary
magnetic field
   /
7416
interaction of microwaves propagated through a gaseous discharge
plasma  experimental observations are reported on the interaction
of and signals in discharge plasma produced in he ne ar kr xe and
h gases over the pressure range mm hg pulse excitation being used
the disturbing wave was pulse modulated and the wanted cw transmitted
through the decaying plasma was detected by means of a cavity resonator
the amplified envelope being displayed on a cro  typical oscillograms
showing the modification of the envelope of the wanted wave due to
the pulsed disturbing wave are reproduced  when a magnetic field
is applied the interaction is observed at low signal levels for which
no effect is found in the absence of the magnetic field  see also
of goldstein et al and back reference
   /
7417
the characteristics of an electron beam entering a coaxial magnetic
field  the effect of nonuniformity field on the convergence of an
electron beam is studied by considering a particular field configuration
and calculating the path of an electron at the edge of the beam
the radius of the beam is plotted as a function of distance travelled
in the transition zone for different values of a parameter which
is dependent on current density accelerating voltage and length of
the transition zone
   /
7418
calculation of the electrostatic capacitance of a conductor by the
method of excess and deficit application to the case of the cube
using a method based on a theorem due to fichera the capacitance
of a cube of side a is found to be between
   /
7419
a high resolution aerial for radio astronomy
   /
7420
on sunspots and magnetic storms  study of the correlation between
active sunspots and geomagnetic storms shows that the effect of central
meridian passage of active sunspots on the occurrence of storms is
more evident when the activity is defined by both the spot type and
the magnetic character than by the spot type alone  this is particularly
noticeable in the case of geomagnetic storms with gradual commencements
   /
7421
control of geomagnetic activity by sunspots  statistical analysis
of the sunspots observed in and shows that as regards their effect
on geomagnetic activity they can be divided into two distinct classes
radio emissive spots the source of relatively dense corpuscular jets
and accompanied by marked peaks of mean geomagnetic activity sunspots
with no corpuscular or a radio emission sunspots with no corpuscular
or radio emission causing a marked reduction of geomagnetic activity
in the case of many spots of this latter type the geomagnetic activity
returns quickly to normal to days after the spots pass the central
meridian
   /
7422
proposals for the statistical treatment of geomagnetic micropulsations
a system of classification is suggested in which the magnitude duration
and regularity of the pulsation trains are assessed semi quantitatively
   /
7423
some characteristics of magnetic storms part magnetic storm on august
analysis of data from many observatories all over the world
   /
7424
the morphology of geomagnetic storms an extension of the analysis
of d the disturbance local time inequality
   /
7425
further notes on a new theory of magnetic storm
   /
7426
a suggestion for the electric conductivity of the upper atmosphere
from an analysis of diurnal variations of terrestrial magnetism
part  diurnal variations of the electric field and electrical conductivity
of the upper atmosphere are deduced from the observed variations
of the geomagnetic field
   /
7427
on the auroral zone current  analysis of eleven examples of auroral
zone disturbance of the geomagnetic field in the second international
polar year indicates that the height of the zone currents may be
km or less the current intensity for moderate magnetic disturbances
being of the order of a very large increase in the electron density
of the d and e layers being thus indicated
   /
7428
the mean vertical ozone distribution resulting from the photochemical
equilibrium turbulence and currents of air
   /
7429
ursigrams  abbreviated codes are given for european ursigrams and
modifications in the french ursigram transmissions are tabulated
   /
7430
the continuous layer formation in the atmosphere under the influence
of solar radiation  the formation of ionized layers in the atmosphere
under the influence of a quiet sun a disturbed sun is the influence
of a quiet sun a disturbed sun is found possible in both cases if
account is taken of the variation with height of the dissociation
of the molecular constituents the ionization of the different constituents
at various altitudes  the expression continuous layer formation
signifies continuous increase and decrease of the electron density
with height throughout the ionosphere
   /
7431
formation of the d layer  measurements of absorption cross sections
of various gases are described  the results favour the assumption
that absorption of solar radiation by no is largely responsible for
the formation of the d layer
   /
7432
determination of the coefficient of recombination in the ionosphere
a simple method is suggested in which the recombination coefficient
is determined from night time observations in terms of the gyrofrequency
the mean observation frequency and the time interval between the
disappearance of the ordinary and extraordinary ray echoes  the value
of for the f region found by this method using records of radio ceylon
transmissions on is sec  using vertical incidence measurements at
calcutta a value of cm sec is obtained compared with cm sec calculated
by the usual method
   /
7433
a statistical study on the minimum frequency in curve for the e region
of the ionosphere  the diurnal and seasonal variation of the minimum
frequency in the curve for the e region is investigated and also
its relation to the sunspot number  the diurnal variation suggests
the existence below the e layer of an absorbing layer which is ionized
by solar radiation  the electron density in the d layer is estimated
to be cm
   /
7434
wave hypothesis of moving irregularities in the ionosphere  a preliminary
discussion of magneto hydrodynamic effects which may afford an
alternative explanation of the motion of ionospheric irregularities
usually referred to as winds in terms of the propagation of a wave
like disturbance  it is found that travelling atmospheric disturbances
governed by pressure oscillations and gravitational forces will
be accompanied by em oscillations which can under special resonance
conditions become large  the corresponding amplification of the associated
electron motions would render such disturbances particularly
susceptible to detection by radio methods  gravity tends to confine
the movement of these disturbances to the horizontal plane but a
secondary vertical component is possible a full treatment is to be
published later
   /
7435
an analysis of electron density variations in the f layer after sunset
analysis of data obtained at kokubunji taking temperature variations
into account and assuming a linear law for the rate of disappearance
of electrons indicates that the nocturnal variation of electron density
in the f layer is explained more satisfactorily by the attachment
theory than by the recombination theory  the corresponding temperature
variations deduced are not satisfactory for the winter months for
which other factors must be taken into account
   /
7436
critical frequency variations  twelve month running averages of f
are plotted against twelve month running averages of the sunspot
number for two stations in the northern hemisphere two in the northern
hemisphere two in the southern hemisphere and one near the equator
for the northern hemisphere stations the slope of the curve is less
at the higher values of sunspot number for the southern hemisphere
stations the slope is constant and for the equatorial station the
slope varies in an intermediate manner  these differences may be
related to the differences in the annual variation of f in the various
regions considered
   /
7437
effects on the f regions of the ionosphere of the solar eclipse of
may  observations indicated the development during the eclipse of
a new layer between the f and f layers  discontinuities of the f
layer critical frequency and virtual height curves and of the f layer
critical frequency curve were noted for a period of about min before
and after the first contact  estimates are made of the electron density
variations involved
   /
7438
the h t measurement of ionosphere at the time of the annular eclipse
of may at wakkanai hokkaido in japan  measurements were made at frequencies
of and  the results obtained show that the absorption in and
below the e layer decreased as the eclipse approached its maximum
and increased again after the maximum phase the maximum f layer electron
density began to decrease immediately after first contact and continued
to decrease to a minimum about min after the maximum phase of the
eclipse then recovering
   /
7439
day variations in the absorption of the d region of the ionosphere
over singapore and slough  apreciable variations of d layer rf absorption
with a day period are found throughout the year at singapore but
only during the u summer months at slough  other variations of absorption
of larger amplitude than in summer are found at slouth in the
winter months but are not related to the solar rotation period of
variations of particle radiation  the bearing of these results on
radio communication and on ionospheric forecasting is discussed briefly
see also of
   /
7440
measurement of ionospheric absorption  the significance of ionospheric
absorption is discussed and commonly used methods of measurement
are examined
   /
7441
the recombination coefficient and the temperature variation in the
upper atmosphere at night  the value of the f layer recombination
coefficient at kokubunji near tokyo shows a marked seasonal change
the maximum being in january and the minimum in june july  calculation
of the corresponding relative temperatures indicates that in winter
some mechanism other than temperature variation must be taken into
account
   /
7442
the solar flare type variation in geomagnetic field and the integrated
electrical conductivity of the ionosphere part  assuming that the
solar flare type of variation of the geomagnetic field is caused
by anomalous increase of the electrical conductivity of the ionosphere
treatment based on the dynamo theory gives a value for the integrated
conductivity of the ionosphere of the order of which is in good agreement
with the value deduced from ionospheric observations
   /
7443
the solar flare type variation in geomagnetic field and the integrated
electrical conductivity of the ionosphere part effect of f layer
analysis of mutual inductance effects between different ionosphere
layers shows that as regards the effect of layer currents on the
geomagnetic field a single layer can be assumed the conductivity
of which is equal to that of the various layers integrated vertically
throughout the whole conductive region  the previous estimate of
about emu  for the integrated conductivity of the whole ionosphere
is thus confirmed  part above
   /
7444
the solar flare type variation in geomagnetic field and the integrated
electric conductivity of the ionosphere part effect of the earth
further ductivity of the earth  part above
   /
7445
the solar flare type variation in geomagnetic field and the integrated
electrical conductivity of the ionosphere part the conductivity of
the ionosphere over japan  statistical analysis of data obtained
at kakioka during gave the averaged value of te the integrated electrical
conductivity of the ionosphere over japan as emu  part above
   /
7446
the shielding effect of the ionosphere  analysis of the effect of
the ionosphere in screening the earth from external em fields taking
account of the conductivity of the earth
   /
7447
ionospheric stations  a list is given of all stations from which
results of observations are regularly received at slough in a second
list which replaces those previously published ionospheric stations
are grouped according to the country controlling them
   /
7448
atmospherics with very low frequency components
   /
7449
radio research special report no characteristics of the ionosphere
observed in great britain  report of measurements slough and at burghead
   /
7450
development of an absorber for electromagnetic waves  theory is given
relative to the design of mesh networks suitable for screening electrical
equipment from em radiation within a specified frequency band
   /
7451
power requirements for transistor circuits  primary requirement for
transistor power supply is constancy of voltage or current with time
long life and small size are next in importance  these requirements
are all satisfied by rm cells of
   /
7452
high voltage generation for television equipment and oscillographs
a review of various methods described in the literature on the subject
   /
7453
effective current and efficiency of small mains supply units with
capacitively terminated rectifiers  when a mains transformer is wholly
or partially loaded by a capacitively terminated rectifier network
the effective value of the rectifier current pulses is determinative
for the copper losses and the waveform distortion for the magnetic
losses  effective current and efficiency curves are presented for
various simple types of rectifier circuits
   /
7454
a stabilised extra high tension rectifier for  description of equipment
using a triode control valve which functions as a variable resistor
in the dc circuit  the reference voltage is provided by a dry battery
the output voltage fluctuations are only of those of the mains supply
the output voltage fluctuations are only of those of the mains supply
the output voltage is variable between and in four overlapping stages
each subdivided into steps which can be varied continuously  protective
measures are described
   /
7455
impedances of the electrolytical rectifier  the impedance characteristic
of an electrolyte rectifier is investigated experimentally  a method
for calculating an equivalent circuit of the oxide layer from the
frequency dependence of its impedance is described  it is concluded
that rectification occurs by means of contact between p type and
n type semiconducting layers
   /
7456
voltage stabilization with series valve control  analysis of the
operation of equipment taking a large load current
   /
7457
corona discharge tubes for voltage stabilization comment on of april
and authors reply
   /
7458
geometrical transformation of impedance diagrams  note on the use
of graphical methods and of riemanns number sphere in impedance calculations
   /
7459
the concept of instantaneous frequency  discussion shows that this
concept can properly be applied to the cases of demodulation by a
linear discriminator and fm of a self oscillator by variation o a
parameter of the circuit but its use in other cases such as calculation
of the harmonic distortion of a simple tuned circuit leads to erroneous
results  this is demonstrated by rigorous calculation of the distortion
introduced by an lgc circuit in the anode circuit of a pentode amplifying
stage
   /
7460
theory of the magnetic amplifier with free magnetic amplifier with
free am magnetization
   /
7461
comparison of methods of analysis of magnetic a amplifiers
   /
7462
types of magneticc amplifiers survey  a scheme for classifying magneti
amplifiers under three main headings with subdivisions by number
and letter is proposed and discussed
   /
7463
the figure of merit of magnetic amplifiers  combination of complex
number and boolean algebra is outlined which can be applied in the
analysis and synthesis of networks containing switches
   /
7464
a method of designing transistor trigger circuits  a fairly general
technique was developed after the war for designing circuits that
would operate with valves having characteristics which varied within
fairly wide tolerances without component adjustments being necessary
when valves were changed  a similar technique is outlined for point
contact transistors this is based on valve circuit technique and
particularly on the analogy between the characteristics of transistors
and pentodes  basic pule circuits considered include state devices
timing circuits counters and relaxation oscillators  their application
in digital computers is reviewed in detail
   /
7465
nonlinear condensers  the properties and applications of high permittivity
materials containing are discussed with particular reference
to the dependence of the dielectric constant on temperature and on
the voltage applied  applications of capacitance with the dc bias
voltage in a modulator and in a capacitor type amplifier are described
   /
7466
the nonlinearity of titanate capacitors  ferroelectric and ferromagnetic
materials are compared and expressions for the specific nonlinearity
are derived for both  these expressions give the hysteresis loss
cm referred to unity circular frequency and a reactive power of
the specific nonlinearities of material with a dielectric constant
of and ferrite with an initial permeability of the same order of
magnitude
   /
7467
the use of short transmission lines in ultra high frequency techniques
lines of length are considered their uses as inductances capacitances
and resonant circuits are reviewed  numerical examples are given
applications as filters and impedance transformers are described
   /
7468
new hf proximity effect formula  arnolds results of are somewhat
complex  a new asymptotic formula was therefore developed which is
valid whenever the proximity effect is so great that the resistance
of the apir of parallel conductors is more than doubled  a combination
of the maxwell equation and integral equation approaches is used
in deriving the new impedance formula which is rigorous and very
simple
   /
7469
the equivalent q of rc networks  the effective q factor of a rc phase
shift network is defined as one half the rate of change of phase
with frequency at the operating point  for networks commonly used
as frequency determining elements the effective q value is about
unity but a capacitance type of r bridge t network may have a q value
of
   /
7470
design of low frequency constant time delay lines
   /
7471
ultrasonic delay lines  survey of the characteristics and operation
of delay lines using fused quartz or glass rods with quartz crystal
transducers
   /
7472
a new non reciprocal waveguide medium using ferrites  a narrow ferrite
strip is attached along the wall of a circular section waveguide
and subjected to a transverse magnetic field  a difference in phase
constant exists for the two directions of transmission along the
guide  for suitable ferrite dimensions a nonreciprocal rotation of
the plane of polarization of an em wave takes place  a more complete
theoretical explanation is to be published  the case of an axial
ferrite rod with an applied axial field has been considered by hogan
of
   /
7473
semifinite terminated electric wave filters  intended for s use either
as channel filters or to work between a finite resistance at one
end and a very high or very low impedance at the other  two design
methods are presented one based on the equivalent image parameter
filter the other on norton and darlingtons insertion loss procedure
the minimum ratio of terminating resistances lies between and for
most applications
   /
7474
a new approach to optimum filtering  in filter problems if enough
is known about the signal and the noise to describe them accurately
by their power spectra conventional methods based on wieners original
method will provide the most effective filters  an alternative procedure
for computing optimum filters based on description of the signal
in terms of a partial sum of orthogonal functions is presented  this
will specify good filters with far less labour than is necessary
in the wiener method and it has a wider range of practical application
a table of summation orthogonal analogues of the laguerre functions
which are useful in this procedure is appended
   /
7475
synthesis of a dynamically variable electronic filter  the principles
of network synthesis are applied to the design of a variable bandwidth
filter with an upper cut off frequency which can be varied dynamically
over the frequency range kcs  the bandwidth variation is automatically
controlled by voltages applied to the control grids of pentodes slight
changes occurring in selectivity and midband gain
   /
7476
printed and potted electronic circuits  survey and assessment of
production techniques and description of some applications
   /
7477
russian circuit notations  the methods adopted for indicating the
values of resistors and capacitors on russian circuit diagrams are
explained
   /
7478
a relation between susceptance slope and selectivity for oscillator
design  two quantities the slope of the susceptance curve computed
at an antiresonance frequency the dimensionless selectivity factor
q are significant in specifying the performance of oscillatory circuits
the relation between the two quantities for practical resonant circuits
is discussed and general conclusions are drawn relating to resonant
circuit design  these conclusions are applied to the comparison of
the clapp and colpitts types of oscillator and to the study of the
equivalent circuit of a quartz crystal operating near resonance
   /
7479
subharmonics in a series nonlinear circuit as influenced by initial
capacitor charge
   /
7480
note on the response of an lcr circuit
   /
7481
the transvar directional coupler  the coupling element consists of
closely spaced identical apertures separated by grid wires in the
common narrow wall between two waveguides  by changing the relative
longitudinal position of the two waveguides the number of exposed
apertures and hence the effective coupling length can be changed
power transfer is variable between and at  maximum power transfer
is available at one frequency only and hence bandwidth depends on
the tolerable decrease in power transfer  two models with and differing
only in grid wire diameter have maximum power transfer at about and
respectively  agreement between theory and performance is close
   /
7482
external influences on the circuit properties of uhf resonators
the q of a cavity resonator depends not only on its physical dimensions
and the material of which it is made but also on the surface finish
the influence of the material and its finish on the fundamental damping
and resonance resistance is investigated for resonators of various
types  an examination is made of the degree of roughness permissible
with reference to standard specifications on surface finishes  effects
due to variations of atmospheric temperature pressure and humidity
and methods of eliminating these effects are also discussed
   /
7483
interaction of modes in a microwave cavity resonator  the minimum
energy differences between the desired and undesired modes in a cylindrical
resonator are calculated by considering the em field inside
the resonator as due to an infinite number of harmonic oscillators
expressions for the mutual energy and the coefficient of coupling
between the companion modes and are derived  the significance of
the total energy of a micro wave cavity resonator is discussed
   /
7484
power spectrum of a nonlinear oscillator perturbed by noise  analysis
of the effect of background noise in producing amplitude fluctuations
if the steady state of an oscillator is disturbed recovery takes
place exponentially with a time constant which is the principal factor
affecting the noise power spectrum  simple relations between and
the circuit parameters are derived which show that for minimum noise
power oscillations of large amplitude should be used without introducing
too many harmonics and the phase of the feedback should vary only
slowly with frequency  see also of april and back references
   /
7485
two rc oscillator circuits  cathode coupled and transitron types
of rc oscillator are described which operate at freu frequencies
of about and respectively
   /
7486
low power blocking oscillators  information of use in final adjustment
of blocking oscillators particularly as regards requirements for
short rise times and narrow pulses is reviewed  a linearized equivalent
circuit is used to derive an explicit expression for pulse duration
which gives results in agreement with experiment particularly when
the grid coupling capacitor is small
   /
7487
use of servo techniques in the design of amplitude stabilized oscillators
expressions for the oscillation amplitude in terms of the stabilizing
signal voltage are derived and the amplitude stabilizing system
is discussed as a negative feedback loop  experimental and theoretical
results for a high q oscillator are compared
   /
7488
fm transistor oscillator  a titant titanate capacitor is coupled
to the resonant circuit inductor of the transistor oscillator the
transformation ratio being chosen at will  varying the potential
applied to this capacitor alters its effective capacitance and hence
the resonance frequency  a polarization potential is applied from
a zamboni pile to keep the capacitance variations within the linear
range  a oscillator constructed used a junction transistor and had
a power output of when supplied from a battery  the titanate capacitor
consisted of two series connected units  a oscillator using a type
point contact transistor gave similar results  some form of a fc
is desirable in view of the temperature variations of the components
   /
7489
an oscillator with constant output voltage  the theory and design
of an uput voltage stabilizer circuit are given  by a suitable choice
of the values of two resistors and of the constant reference voltage
the oscillator output voltage is made virtually independent of valve
characteristics and circuit impedance  an application to the calibration
of valve voltmeters is described
   /
7490
mechanism of the synchronization of lc oscillators the pulling effect
on the phase a and frequency of an lc oscillator due to interference
is considered  the phase change is calculated for the case of a single
interfering pulse a series of equidistant pulses and a sinusoidal
voltage  interfering pulses occurring at an oscillator voltage peak
affect the amplitude those occurring at zero voltage cause a change
in phase only  these phase changes are permanent  a differential
equation relating oscillator voltage phase deviation time peak oscillator
voltage and the magnitude of the interference current is solved
and the conditions for synchrononism are obtained
   /
7491
some aspects of mixer crystal performance  a method of calculating
conversion loss and conductances of a crystal mixer is presented
and their dependence on terminations at the image frequency and at
the sum frequency is considered  experimental data from various sources
support the calculations  graphs showing excess crystal noise versus
output frequency and mixer noise temperature versus crystal noise
temperature for varying conversion loss are derived and applied together
with the conversion loss data to practical calculations of optimum
mixer configuration and optimum if  two examples are worked out
experimental confirmation of results was obtained
   /
7492
automatic frequency control of high power klystrons  a method of
control is described in which a cavity resonator and two microwave
crystals are used as a standing wave discriminator in a system for
automatic frequency search and lock for a pulsed klystron oscillator
frequency stability to within part in is achieved
   /
7493
length of coherent microwaves generated by an electronic oscillator
investigation of the noise associated with the generation of oscillations
of frequency by a reflex klystron showed a bandwidth of about
this is attributed to fluctuation of the electron beam
   /
7494
the square wave generator  the circuit of a multivibrator type of
generator with stabilized input is shown and a complete analysis
based on the characteristics of the double triode type is given
   /
7495
a reliable locked oscillator pulse timer  description with complete
circuit diagram and method of adjustment of a highly stable locked
oscillator pulse timer providing pulses with recurrence frequency
from a input  the frequency divider has previously been described
of  the unit has an overall phase stability to within per volt of
line voltage change
   /
7496
an analogue reciprocal function unit for use with pulsed signals
a monostable multivibrator operates so that the width of the pulse
generated is approximately inversely proportional to the peak voltage
of an input pulse  the pulse width variation is converted to a corresponding
amplitude variation of sawtooth output pulses by means of a
constant velocity timebase circuit
   /
7497
calculations for a power amplifier for driving a dc motor  analysis
of a symmetrical class a amplifier supplying energy to a motor connected
in the cathode circuit of the output stage  see also of march
   /
7498
high power audio amplifiers  recent applications for a f power up
to include vibration work servomechanism studies pulsed service and
variable frequency power sources all of which require response distortion
and noise level characteristics similar to those for broadcasting
service  in high power amplifiers with class b push pull output the
output transformer is the largest and most expensive item in the
equipment and may weigh some hundreds of pounds  a new equivalent
circuit is used in the design of such transformers  harmonic distortion
caused by the transformer is analysed and methods of improving the
performance of class b power amplifiers are described  a few details
are given of a amplifier with a response curve flat to within from
to
   /
7499
general design considerations of a cavity type power amplifier  details
r are given of the construction of a single stage amplifier using
a type triode valve  constant current curves for class c grounded
grid operation were used to determine the operating parameters of
the triode  a stage amplifier using and triodes is described with
performance details
   /
7500
a simple low frequency amplifier  description of a tuned amplifier
circuit for the range incorporating a damped phase shift oscillator
with independent control of resonance frequency and q factor
   /
7501
differential law for the intensities of electrical fluctuations and
influence of skin effect  an investigation is made of the form of
the correlation function of the external field which expresses the
thermal electrical fluctuations in a conductor and of the differential
law on which nyquists integral formula is based
   /
7502
on the temperature dependence of contact noise  results of noise
measurements on se and cu rectifiers and on carbon resistors over
different temperature ranges between and are shown graphically
   /
7503
subharmonic oscillations in nonlinear systems  the order of the subharmonics
in systems with nonlinear restoring force is closely related
to the form of the nonlinearity  a detailed analysis is presented
for the subharmonic oscillation of order for the cases in which the
nonlinearity is expressed by a cubic or a quintic function  stability
is discussed by means of the criterion previously given o august
   /
7504
step by step transition from wave optics to ray optics in inhomogeneous
absorbing media part equations for wave normal refractive index and
polarization  the transition is made by successive approximations
each approximation is considered from the physica point of view and
th physical significance of the equations derived is considered
   /
7505
luminescent layers and films with polyvinyl alcohol as protective
colloid and binder
   /
7506
electroluminescence electrical and optical properties  electro optical
measurements are reported on electroluminescent lamps operating on
the principle described by payne et al and fundamental properties
of electroluminescent phosphors are studied
   /
7507
oscillatory phenomena of arc in hot cathode discharge tube part theoretical
mechanism of oscillation  of
   /
7508
space charge spread of reflected electron beams studied by a photographic
method
   /
7509
the self charge spreading of a fucused electron beam  simple formulae
derived from wave mechanical considerations are obtained for the
upper limitems of the self charge effects ie spreading of beam and
displacements of image plane and fraunhofer plane
   /
7510
energy distribution of thermo electrons in electron beam devices
experiments are described which show that the energy distribution
of the thermo electrons in oscillograph tubes electron microscopes
etc is not of the maxwell type  the deviations from the maxwell distribution
particularly in the low energy range are attributed to reciprocal
dynamic effects
   /
7511
on the theory of the ising model of ferromagnetism
   /
7512
the two dimensional magnetic or electric field above and below an
infinite corrugated sheet
   /
7513
a conducting permeable sphere in the presence of a coil carrying
an oscillating current  the secondary magnetic fields due to the
sphere are calculated for frequencies
   /
7514
current element near the edge of a conducting half plane  the two
dimensional problem of the maxwellian field from a line source of
current adjacent to conducting half plane is treated by a transform
method of solution  expressions in the form of contour integrals
are given for the current induced in the conductor and for the radiated
field
   /
7515
the scattering of waves at an uneven surface  an approximate method
is proposed for calculating the field of acoustic and electromagnetic
waves scattered by an uneven surface the irregularities being large
in comparison with the wavelength particular cases considered include
that of sinusoidal corrugations
   /
7516
scattering of waves by a statistically irregular surface  a method
is proposed for calculating the field of plane waves scattered by
a perfectly reflecting statistically irregular surface the irregularities
being large in comparison with the wave length  the method can
be used for acoustic as well as electromagnetic waves
   /
7517
quenching of afterglow in gaseous discharge plasmas by low power
microwaves  continuation of work noted in of september  results are
reported for neon of the effect on the plasma decay of applying microwave
pulses at various time intervals after the production of the plasma
the state of decay was determined by observing the afterglow by means
of photocells and displaying the amplified photocurrent on an oscilloscope
decrease of light intensity observed during the application
of the pulse is most probably due to reduction of the recombination
rate  differences in the traces observed at pressures of mm hg and
mm hg are discussed  the effect may be useful for detecting the energy
   /
7518
on some features of noise storms  discussion of solar rf emission
of abnormally high intensity on metre wave lengths  the radiation
is circularly polarized may last for several hours and is often associated
with sudden bursts of nonpolarized radiation  the association
of such noise storms with large and magnetically active sunspots
is considered
   /
7519
time variation of the earths magnetic field at the time of bay disturbanced
   /
7520
distribution of sc of magnetic storms  the abbreviation sc is used
to denote the reverse impulse preceding a sudden commencement  the
distribution with respect to local tim and latitude was examined
from records obtained at five us stations during a period of years
and also from world wide records of individual geomagnetic storms
the reverse impulses appear chiefly in the afternoon with a maximum
at about local time  the pulse magnitude as well as its ratio to the
succeeding main pulse increases markedly with geomagnetic latitude
   /
7521
the recurrence tendency of magnetic storms  data relative to storms
observed at aso magnetic observatory during the period september
august are analysed  storms showed no recurrence tendency  the rest
are divided into groups each containing several storms recurring
at intervals of about days
   /
7522
correlation of magnetic m storms with the monochromatic corona  results
obtained at wendelstein show that a maximum of geomagnetic activity
is observed days before the central meridian passage of a region
of g high coronal activity or days after the appearance of bright
coronal emission at the east solar limb  similar characteristics
are found for the minimum epochs  the relation apparently holds good
only when no visible or significant sunspot phenomena exist
   /
7523
radio echoes observed during aurorae and terrestrial magnetic storms
using and waves simultaneously  a report of observations at tromso
near the auroral zone and at kjeller near oslo  the two pulse transmitters
at each station had common pulse modulators so that the shape
and energy of the pulses could be made identical  the peak pulse
power was and repetition frequency sec  echoes on appeared regularly
at tromso during auroral displays and in a number of cases also on
study of the results led to the conclusion that the echoes were not
due to direct scatter from the ionosphere but could be explained
by reflection of backwards scatter from land or see via the e layer
the ionization of which increases greatly during aurorae and geomagnetic
storms  in all cases the echoes on showed a x smaller range than
those on the difference in range usually exceeding km  differences
between the echo patterns on the two frequencies are noted  a full
account of the observations will be given in
   /
7524
constitution of polar magnetic storms  analysis of data obtained
in the international polar year indicates that polar magnetic storms
consist of a number of elementary disturbances which occur successively
the equivalent current system corresponding to these disturbances
can be represented approximately by that due to an electric dipole
located in the auroral zone
   /
7525
constitution of polar magnetic storms  an examination of world wide
data relative to the polar magnetic storm on april confirms the conclusions
noted in above
   /
7526
annual variation of reduced density and mean temperature of atmospheric
ozone in afghanistan
   /
7527
abbreviated codes of european ursigrams part  the codes here given
are data on monochromatic intensity of the solar corona coron code
data on e critical frequency esfre code data on f critical frequency
fodeu code for hourly values symbo code for descriptive symbols for
the values given terrestrial magnettism magne code ionospheric disturbance
warning pertu code radio solar emission observatories soler code
part of september
   /
7528
european ursigrams  correction to of september
   /
7529
some characteristics of ionospheric storms  analysis of data for
the f region  the frequency of occurrence of disturbances in this
region is closely related to its seasonal height being greater in
summer than in winter
   /
7530
classification of f layer storms with respect to their world wide
distribution and characteristics part of  analysis of available data
shows that there is no correlation between f layer storms and sunspot
activity but close correlation with geomagnetic storms  a classification
of these storms with respect to their distribution over the geomagnetic
latitudes is suggested based on layer height or critical frequency
characteristics
   /
7531
on world wide distributions of f  hourly values of f observed at
stations distributed all over the world during the period are analysed
contour lines being used to indicate places with common critical
frequencies  diagrams are also given showing the distribution of
the difference between and its monthly mean value at and at on may
the distribution of for noon local time on the same date the latitude
distribution o of for noon local time on longitudes and
   /
7532
on the cause for unnatural distribution of occurrence of and  observations
carried out at kokubunji indicate a correlation between receiver
interference and the frequency of occurrence of and
   /
7533
a relation between f layer disturbance and geomagnetic condition
a correlation is found between the daily mean value of the electron
density of the f layer and the storminess of the geomagnetic field
the f layer electron density appears to decrease in local summer
and increase in local winter in the middle latitude regions of both
the northern and southern hemispheres
   /
7534
characteristics of ionospheric disturbances during severe magnetic
storms  analysis of world wide data from ionosphere stations for
the period may including two geomagnetic storms with sudden commencements
shows that an ionospheric disturbance coincident with a sc in
a region of high geomagnetic latitude spreads down to lower latitudes
in high latitudes the disturbances travel at a high velocity which
is about in the vicinity of japan  the intensity of the disturbance
decreases with latitude  the connection between the time of occurrence
of a sc and disturbance of radio communication is briefly discussed
   /
7535
studies on ionospheric storms  a definite relation is found between
the types of storm discussed by appleton and piggott of and the seasons
in which they occur  the development of ionospheric storms is discussed
in some detail  the need for further world wide ionospheric investigations
particularly in high latitudes and at intervals less than an
hour is stressed
   /
7536
modern ionosphere sounding equipment of the netherlands ptt  full
description with block diagrams of a pulse equipment for the range
pulse duration is adjustable from to repetition frequency is sec
a complete frequency sweep can be made in either or sec  two cr tubes
in parallel provide monitoring and photographic facilities
   /
7537
ccir ursi co operation  exchange of information for forecasts and
warnings
   /
7538
anomalous ionization in the upper atmosphere over the auroral zone
during magnetic storms  the depth of penetration of and the rate
of ionization by protons of extraterrestrial origin are estimated
an explanation is given of the rapid variations of the geomagnetic
field in and near the auroral zone
   /
7539
the application of nonlinear techniques to servo mechanisms
   /
7540
the transient response of a single point nonlinear servomechanism
   /
7541
servo systems comparators
   /
7542
compensation of a magnetic amplifier servo system
   /
7543
synthesis of compensation networks for carrier frequency servomechanisms
   /
7544
screening of test rooms and instruments from electromagnetic fields
screens made of wire mesh metal foil and sheet and of materials with
a high expressions are given for the attenuation of incident em waves
experimental curves for sheet and mesh screens are given  the construction
of a large screened room is described and the attenuation of
magnetic fields in this room for frequencies from to is compared
with that of other rooms  a novel type of honeycomb wire mesh strip
window screen is described
   /
7545
reactivating the dry cell  discussion of the effect on cell life
of repeated passage of current in the reverse direction
   /
7546
note on the optimum input winding resistance of a magnetic amplifier
employing voltage feedback
   /
7547
transistor controlled magnetic amplifier  a circuit is described
in which the collector toroidal core this part of the circuit being
completed via the secondary of a transformer primary coltage at and
the load resistor back to the transistor base electrode  with this
arrangement output currents up to peak can be obtained in the load
for emitter input signal currents peak  complete response to a change
of input signal is obtained in one cycle of the applied alternating
voltage
   /
7548
collector base impedance of a junction transistor  comment on of
march early
   /
7549
transistor circuits and applications  see of september
   /
7550
theory of afc synchronization  the performance of an afc system can
be described in terms of three parameters the gain constant the damping
ratio and the resonance or cut off frequency  using these parameters
expressions v for the performance under conditions of small disturbance
to the input phase and for the pull in performance are derived two
different types of control network transfer function being considered
   /
7551
the characteristics and applications of thermally sensitive resistors
or thermistors  basic properties of thermistors are reviewed and
terms used to specify their characteristics are defined  outline
descriptions are given of their applications in measurement control
and protection circuits etc
   /
7552
a range of and transductors for service use  a survey of common transductor
types is made and details are given together with particular
applications of input type transductors with n mumetal or permalloy
cores for supply voltages of and rms and power type units with hcr
or permalloy f coe cores for supply voltages of and rms  all are
of the automatic self excitation type
   /
7553
stray capacitance with high permittivity dielectrics  expressions
are derived for the stray es field and stray capacitance of a parallel
plate capacitor  the corrections for stray capacitance of circular
parallel plate and cylindrical capacitors are determined
   /
7554
control of thyratrons by small signals  variations of the phase of
the control grid voltage enables the power supplied by a thyratron
to an external circuit to be varied continuously over a wide range
the results obtained with small control voltages indicate that although
signals as small as may be permissible when the thyratron forms part
of a feedback system large signals should be used whenever possible
   /
7555
a circular waveguide magic tee and its application to high power
microwave transmission  the magic t discussed comprises a circular
section waveguide with two mutually perpendicular side arms of rectangular
section spaced longitudinally at a distance this system constitutes
a pair of h mode transformers  the device can be used as a variable
power dividing or power combining bridge and one of its main uses
is for combining feedback power with power from the source at the
input to a linear electron accelerator  when two similar sections
are joined via a rotatable coupling the resulting system is suitable
for external connection via the rectangular side arms the power dividing
ratio depends on the angle of rotation between the two sections
other applications include use with a circular polarizer to act as
a phase shifter or variable impedance
   /
7556
a contribution to the theory of nonlinear systems  a system of classification
of nonlinear terminal networks is introduced and basic properties
of various classes are established  the system is such that each
class in the sequence n contains as a member the class before it
a general nonlinear network of class n is completely defined by its
responses to a family of step functions with amplitudes ranging over
all real values  an explicit expression is developed for the response
of a class n network to a specified input  modes of realization and
characterization of networks of class n are outlined and a procedure
for determining the optimum filter of any class is ou indicated
   /
7557
the equivalent q of rc networks  comments on of october brown and
authors reply
   /
7558
response characteristics
   /
7559
a note on the analysis of vacuum tube and transistor circuits  the
setting up of node equations for a network containing one or more
active elements is reduced essentially t to the determination of
the admittance coefficients for the passive network resulting from
removal of the active elements and adding to these the corresponding
admittance coefficients for the active elements the latter being
obtained from tables given in the text  mesh equations are obtained
in an analogous way using impedance coefficient tables
   /
7560
tolerance coefficients for rc networks  a method is presented for
determining the effect on network design characteristics of the use
of nonideal components  a set of tolerance e coefficients is derived
relating percentage changes of the positions of the poles and zeros
of the network function to percentage changes of the network components
changes of gain or phase are then easily calculated  an exact solution
is obtainable only when the network contains at most three independent
capacitors  two theorems are proved which serve to check approximations
made for more complex networks
   /
7561
realizability conditions for the series parallel matrix and canonical
series parallel circuits for reactance quadripoles
   /
7562
spinor theory of four terminal networks  a spinor can be described
as a geometrical object in dimensional space having a magnitude and
three eulerian angles  in the application of spinor theory to terminal
networks the four spinor components represent the complex current
and complex c voltage the associated vector represents power and
the direction ratio represents impedance  applications of the spinor
theory are shown but the study is restricted to steady state conditions
negative resistance is not excluded from the considerations
   /
7563
the four pole transmission matrix  comment on of june and authors
reply
   /
7564
the gyrator as a terminal element  a terminal gyrator forming the
nucleus of any terminal network that violates the reciprocity relation
is considered  a method is developed which realizes such an element
with any unilateral transducer such as a valve or transistor  the
effect of loading by parallel or series admittance is investigated
   /
7565
the algebraic theory of linear transmission networks  the theory
is based on the series combination of two networks with equal numbers
of input and output terminals to form a semi group  the theory is
developed in a series of definitions theorems and proofs  fundamental
properties of transmission networks are derived and principal types
of network are classified  by means of a factorization theorem a
simple criterion for symmetry can be derived  the necessary and sufficient
conditions for the existence of a characteristic impedance are
determined  the theory provides a concise definition and a method
of rigorous treatment of the general transmission line
   /
7566
simplified solution of phase shift networks  the method is particularly
applicable to phase shift circuits in rc oscillators and selective
amplifiers  the arbitrary initial assumption is made that all reactive
network elements can be treated algebraically as resistances ie as
scalar quantities this enables mesh equations to be written down
and solved simply the results being then interpreted in terms of
the complex quantities involved  three illustrative examples are
worked out
   /
7567
a simple connection between closed loop transient response and open
loop frequency response  the phase margin concept of the characteristics
of the nyquist diagram in the vicinity of the critical point is extended
to give a more generalised formula  this relates the damping of the
principal oscillatory mode of a closed loop feedback system to the
shape of the nyquist diagram  all the quantities involved can be
obtained from this diagram without further mathematical analysis
or graphical construction on the diagram
   /
7568
new linear passive nonreciprocal microwave circuit component
   /
7569
termination variation in the constant k filter  the problem treated
is that of finding the modification required in a conventional filter
when the terminations are resistive but otherwise quite general the
filter elements are given normalized values and in addition modified
by factors and to correspond with the change in termination from
equal values to those modified by factors and  from the expressions
for the insertion transfer ratio of the original and of the modified
circuit by equating appropriate terms and solving a diagram is constructed
relating the four factors and  two numerical examples illustrate
the practical application of the diagram in the design of filter
half sections  full section and multisection filters are treated
in similar fashion the calculations being correspondingly more complex
   /
7570
synthesis of narrow band direct coupled
   /
7571
design of symmetrical bridge type electrical filters by the operating
parameter theory  design formulae are developed and tabulated for
symmetrical low pass filters of degrees and for attenuation characteristics
with given zeros and poles  a review of the theoretical foundations
is based on work by cauer of and by darlington of
   /
7572
a unitary design system for band pass filters of the zobel and laurent
types  a systematic representation of the properties of band pass
filters based on the wave parameter theory is followed by the development
of general design formulae for band pass half sections including
the zigxag filters of laurent  the system is based on cauers classification
of q functions supplemented by some intermediate functions
   /
7573
a band pass filter for low frequencies  description with circuit
diagrams of a filter with a pass band of consisting of four stagger
tuned rc amplifier circuits with inputs and outputs connected in
parallel by resistor networks  the filter was developed for band
encephalography
   /
7574
synthesis of poles by networks containing the minimum number of elements
the method of r brune is extended to the synthesis of passive
poles the procedure is illustrated for  after splitting off a series
resistance the number of elements in the pole can be reduced and
by repeating this procedure the pole of zero order can be realized
as shown
   /
7575
the coaxial system amplifiers
   /
7576
high frequency oscillators designed for regulation and control of
aircraft vhf equipment  description of a quartz controlled fixed
frequency unit and a vfo with a frequency converter for the range
of  a quartz crystal provides check points for all harmonics of in
the range of the vfo
   /
7577
action of an unlimited train of telegraphic signals on a resonant
rlc circuit  the response of a series rlc circuit to a train of pulse
signals is considered for three types of pulse rectangular symmetrical
trapezoidal and of sine squared form  analysis shows that in the
steady state whatever the degree of mistuning of the circuit with
respect to the signal hf the amplitude of the current varies continually
with time  the variations are due partly to energy dissipation during
the intervals between the signals and partly to beating of the forced
oscillations due to the signals with the natural oscillations of
the circuit  the latter effect is particularly noticeable in a very
selective circuit but its magnitude is largely dependent on the degree
of mistuning of the circuit  see also of
   /
7578
amplitude stability in oscillating systems  as a supplement to the
kryloff and bogoliuboff method of determining amplitude of oscillation
in quasilinear systems a method based upon energy balance is presented
from the energy balance condition a criterion for stability of oscillation
is deduced for the case of one degree of freedom  the treatment
is then generalized to systems of n degrees of freedom
   /
7579
quantum theory of a damped electrical oscillator and noise  field
quantization is applied to an electrical oscillating circuit  damping
effects are treated by perturbation theory  quantum effects occur
both in the damping and in the noise and are discussed in detail
the vacuum fluctuations are shown to be observable in certain low
temperature noise experiments
   /
7580
junction transistor circuit applications  the basic circuits described
include amplifiers impedance changing circuits phase inverters oscillators
multivibrators and sawtooth frequency sweep oscillators
   /
7581
self excitation with disk seal valves in a grounded grid circuit
a circle diagram is derived for the internal capacitive coupling
between anode and cathode in a grounded grid oscillator  the phase
of the transconductance and the input admittance resulting from the
long transit times of electrons are taken into account  calculations
for several circuits with external feedback are made with th aid
of the diagram
   /
7582
am fm analogy  a method is described for analysing the response of
a circuit to a fm signal and for determining spectral distribution
based on considering the equivalent signal produced by a series of
sequentially pulsed am carriers whose frequencies range between the
extremes of the fm deviation  the required fm response is obtained
as the synthesis of the responses to these separate am signals  both
aperiodic and periodic signals are considered  the method is particularly
appropriate and gives exact results when the modulating waveform
is rectangular for other cases the results are approximate
   /
7583
the theory and design of cathode follower output stages  limitations
imposed on the design of cathode follower stages feeding loads with
an earthy a end are noted  procedures are outlined for choice of
valve for a particular service and then completing the circuit design
under the conditions that the specified maximum anode current and
anode dissipation are not exceeded and that linear operation is achieved
   /
7584
transistor operation stabilization of operating points  correction
to paper abstracted in march
   /
7585
why fight grid current in class b modulators  by using triode valves
with low anode resistance and low amplification factor efficient
operation of audio amplifiers can be obtained without allowing the
grid voltage to swing positive grid current is thus avoided  direct
coupling may be used between the driving amplifier and a modulator
operated in this way permitting the use of a large amount of negative
feedback  measured response and distortion are presented for a modulator
designed on these lines
   /
7586
a single ended push pull audio amplifier  reprint
   /
7587
analysis of a single ended push pull audio amplifier
   /
7588
coupling of cathode followers in dc amplifiers  a symmetrical phase
reversal circuit is described which together with screen coupled
cathode follower stages has resulted in the development of an amplifier
operated from a single source giving a gain of db and having a flat
response up to kcs  the level of the fluctuation noise voltage is
almost too low to be measurable
   /
7589
harmonic distortion and negative feedback  commets on of august and
authors reply
   /
7590
accuracy of perturbation calculated from inaccurate unperturbed wave
function
   /
7591
 t axcitation of luminescence by variable electric fields primary
effect  reply to herwellys criticisms and description of further experiments
showing clearly that luminescence due to glow discharge can be
distinguished from luminescenced induced by an electric field
   /
7592
electroluminescence a new source of light  a review of developments
since the discovery of the phenomenon by the author in and an account
of recent experimental work  see also of and of payne et al
   /
7593
fundamentals in the behavior of electrets  further mathematical development
for previous work see of and back reference
   /
7594
the resistance of an imperfect contact between two metals comparison
with experimental results for thin granular films
   /
7595
a simple varying capacitor method for the measurement of contact
potential difference in high vacuum  apparatus based on kelvins original
method and suitable for use at a pressure of mm hg is described
the value found for the contact potential difference between cu and
ag films evaporated on to w sheets was the ag being positive with
respect to the cu
   /
7596
on the changes in contact potential difference of a germanium rectifier
during the electrical forming
   /
7597
breakdown of a gas subject to crossed electric fields  experiments
with various gases show that breakdown in a resonator subjected to
voltage pulses with a repetition frequency of is not helped by application
of alternating fields of frequency or perpendicular to the main
field even when such fields are only a little below the value at
which they would cause breakdown if acting alone
   /
7598
formative time lags in the electrical breakdown of gases  the time
rate of growth of ionization currents in a uniform field greater
than that corresponding to the static sparking potential is investigated
theoretically  curves showing the dependence of the formative time
lag on overvoltage are given with an example of their use in the
elucidation of secondary ionization processes operative in the breakdown
mechanism
   /
7599
microwave technique for studying discharges in gases  experiments
were made with a neon filled tube inserted through a pancake waveguide
internal height mm the variation of the discharge dc due to the rf
field being observed on a cro for various relative positions of tube
and guide  the frequency used was about and the rf power
   /
7600
the control of self maintained discharge currents by illumination
of the cathode  the discharge characteristics of neon filled and
photocells illuminated with a hg discharge lamp were obtained experimentally
the magnitude of the controllable current in the townsend
discharge space depends on the illumination of the cathode the driving
potential applied and the value of the stabilizing resistance used
   /
7601
discharge between positive point and plane in compressed air  at
gas pressures of several tens of atmospheres the spark discharge
from a point may be preceded by relatively large currents which are
due either to the corona effect or to a dark discharge resulting
from the emission from the cathode
   /
7602
electron emission from metals as an after effect of irradiation
the emission of electrons from metals was measured after irradiation
with x rays ultraviolet rays and visible rays and after glow discharge
had taken effect  the dependence of the secondary emission on the
wavelength of the incident radiation and on the structure of the
metal surface was investigated  the time and temperature relation
is independent of the manner of excitation which may even be produced
by mechanical means  the magnitude of the secondary emission depends
on the state of oxidation of the surface  it is further discussed
how far the secondary emission depends on the nature of the metal
or the nature of the surrounding gas  the work function of electrons
after irradiation is also considered
   /
7603
surface films and field emission of electrons  the mechanism of cold
emission of electrons from surfaces covered with a tarnish film under
electric fields of the order of was investigated  the results obtained
are consistent with the view that the electrons are extracted from
the metal substrate by the high electric field set up across the
thin surface film when covered with a layer of positive ions
   /
7604
transmission of radio waves through highly ionized gases  preliminary
theoretical discussion of the effect of highly ionized media on the
transmission of em waves with special reference to the possible use
of centimetre waves in the study of the intense thermal ionization
produced in a gas subject to high pressure shock waves
   /
7605
intensity and polarization of electromagnetic waves diffracted at
a slit  part  diffraction of electromagnetic waves at a slit is investigated
under the supposition that the electric field vector is perpendicular
to the slit edges magnetic case  this supplements the investigation
of the same problem for the case where the electric field vector
is parallel to the slit edges electric case of and  the combination
of both cases makes it possible to calculate the intensity and polarization
of the wave field for incident polarized and unpolarized radiation
in the case of very narrow slits to which the fresnel kirchhoff theory
is no longer applicable the electric component normal to the slit
edges is determinative for the diffracted field
   /
7606
sorption properties of thin nickel films  the sorption of o and h
by ni films is studied  oxygen the diffraction of electromagnetic
waves at a conducting circular disk and at a circular aperture in
a conducting plane screen  numerical results of calculations based
on the rigorous theory of diffraction of meixner and andrejewski
of are given  these describe the characteristics of diffracted waves
in the near and far fields and are valid when the circumference of
the disk and the wavelength are of comparable magnitude  the methods
of approximation commonly used are critically examined
   /
7607
est orption which is much greater than that of hydrogen takes place
in two stages instantaneous covering of the film by a monatomic layer
gradual penetration of the oxygen atoms into the film  the quantity
of sorbed oxygen is independent of the gas pressure but depends on
temperature  oxygen covered ni films have catalytic reactions with
hydrogen on the other hand hydrogen films have no effect on the sorption
of oxygen
   /
7608
distribution of radio brightness on the solar disk at mcs  observations
during the first six months of made with interferometer equipment
confirm the results obtained at the annular eclipse of bosson et
al concerning the increased brightness at the edge of the disk  further
observations will be required to determine whether the radio brightness
increases at first uniformly from the centre and then more rapidly
to a maximum near the edge or whether there is a secondary maximum
at the centre
   /
7609
asymmetry in the decimetre wave radiation from the sun  data obtained
in australia at the eclipse of november and in khartoum at the eclipse
of february are adduced in support of the conclusion that radiation
from the quiet sun at wavelengths around cm is best accounted for
by a model sun at wavelengths around is best accounted for by model
sun having an equatorial axis polar axis ratio of  see also of and
back reference
   /
7610
radio noise receivers
   /
7611
provisional sunspot numbers for january to march
   /
7612
solar flare effects and magnetic storms  in the years there appeared
to be no increase in storm probability after the occurrence of a
solar flare effect except perhaps in the probability of severe magnetic
storms
   /
7613
thermal emission from the solar corona in the wavelength range cm
calculations are made of the suns radiation for various models of
the corona  a method is developed for determining the temperature
of the corona from the measured intensity distribution over the solar
disk  radiation from the corona may introduce appreciable irregularities
in the intensity distribution  failure to take account of deviations
from radial symmetry may lead to incorrect interpretation of results
staniers conclusions of may be effected in this way
   /
7614
an investigation of the h regions by a radio method  the distribution
of brightness near the galactic plane was determined from measurements
made with a radio inteferometer at and  the results obtained are
discussed
   /
7615
the harmonic analysis of the earths magnetic field for epoch  there
is no evidence of a dipole field of external origin greater than
of the field of internal origin  the intensity of the latter is at
present decreasing by about per century  the geomagnetic poles have
a westerly drift of per century the mean position of the nr north
magnetic pole at present is
   /
7616
cheltenham three hour range indices k for january to march
   /
7617
on variations of the geomagnetic field fluid motions and the rate
of the earths rotation  see of may
   /
7618
the magnetic secular variation in new zealand  an account is given
of the work on secular variation from to  the observations are tabulated
and the results are presented in the form of isoporic charts for
each magnetic element
   /
7619
relationship between radio propagation disturbance geomagnetic activity
and solar noise  data on ionospheric disturbance of radio communication
between new york and amsterdam during the years are compared with
geomagnetic character figures  a general correlation s is established
the maximum radio disturbance showing a mean time lag of behind the
maximum geomagnetic disturbance  investigation of the relation between
solar rf radiation and geomagnetic storms showed that a marked increase
of the radiation on at least one of the frequencies and occurred
at some time during the five days preceding a storm except in the
case of recurrent storms
   /
7620
principal magnetic storms
   /
7621
international data on magnetic disturbances fourth quarter
   /
7622
physical properties of the atmosphere between and  the calculated
values of temperature pressure molecular weight density and particle
concentration are in fair agreement with available experimental results
   /
7623
the constants in the equation for atmospheric refractive index at
radio frequencies  see of
   /
7624
ionospheric disturbance forecasting  causes and effects of solar
flare disturbances prolonged periods of low layer absorption and
ionospheric storms are reviewed  in an examination of the bases for
predicting ionospheric storms sunspot classification is explained
and the correlation of ionospheric storms with solar flare effects
geomagnetic data and precursor disturbances in high latitudes is
discussed  in general the accuracy of predictions days in advance
is  disturbances ratings used in the storm warning service are given
and methods of prediction adopted during sunspot maximum and sunspot
minimum periods are outlined
   /
7625
a note on the sluggishness of the ionosphere  by analogy with the
lr circuit a time of relaxation analogous to a time constant is obtained
from the equation for the variation of ionization where n is the
electron density and the recombination coefficient  two methods of
determining n are described and its value is calculated for the d
e f and f winter layers  although the value of n varies by a factor
of over n is constant within a factor of about  this result may be
interpreted as indicating either that must fall steadily from the
d to the f layer or that the physical process of electron disappearance
is not merely one of attachment
   /
7626
method of determining the true height of the ionospheric layers taking
account of the effect of the geomagnetic field part application of
an approximate expression for the refractive index ordinary ray case
expressions are derived for the characteristic parameters of an ionospheric
region assuming a parabolic law for the ionization  the values
of the virtual heights of the f layer for frequencies in the range
are calculated and compared with the observed heights and those calculated
by appletons method  the correction term in the expression for
the thickness of the layer shows that the effect of the geomagnetic
field is such as to reduce the value of the thickness  numerical
results are in good agreement with the corrections indicated by shinn
and whale of
   /
7627
dynamic probe measurements in the ionosphere  measurements made during
a rocket flight showed a rapid rise of probe current between and
height which indicated a ps positive ion electron density ratio of
approximately
   /
7628
nature and origin of sporadic e regions as observed at different
hours over calcutta  typical results of the experimental determination
of the variation of the reflection and transmission coefficients
of the e region are shown graphically and a statistical study is
made of the variation of echo amplitude  the amplitude distribution
of e echoes from a thin layer is of the gauss type that from an ion
cloud of the rayleigh type whilst in general both the steady and
the scattered reflection components are present to give a rice type
of distribution of  the results of observations made in the early
morning at sunrise in the z afternoon and during thunderstorms are
discussed and several ionizing agents are suggested
   /
7629
ionospheric storms in the auroral zone  the values of f observed
at college alaska are statistically analysed  when the f layer in
the auroral zone is sunlit the value of f usually begins to decrease
just after the commencement of a geomagnetic storm  this is attributed
to an expansion of the layer due to heating caused by impinging corpuscles
when the f layer is in darkness an increase of f is observed
   /
7630
travelling disturbances in the ionosphere  pulse measurements at
have been made during the past three years at perth western australia
using munros method of  results agree in general with those of munro
the velocities observed ranged between and km min  the direction
of travel in summer lies between and and in winter between and e
of n with a rapid change over in the equinoctial months
   /
7631
f region triple splitting  measurements of the direction of arrival
of z echoes have been made at hobart tasmania  the results indicate
that f region triple splitting is caused by back scattering from
a rough layer  the directions observed are consistent with the assumption
tht reflection at the z level occurs when the angle of incidence
is such that the wave normal becomes parallel to the geomagnetic
field at the ordinary level of reflection
   /
7632
continental maps of four ionospheric disturbances  the changes with
time of the geographical distribution of f deviations from normal
are shown
   /
7633
sweep frequency measurement of the ionosphere  continuous records
of f layer heights were obtained with equipment covering the frequency
band in sec  the records show marked discontinuities at approximately
and local time  the corresponding graphs of f layer heights for several
stations in japan and of the geomagnetic variations at one station
are shown
   /
7634
a consideration of the mechanism of electron removal in the f layer
of the ionosphere  the transformation of atomic ions into molecular
ions by a transfer of charge and the subsequent recombination of
molecular ions with electrons are considered theoretically  such
a mechanism may possibly explain the attachment type of electron
removal but the theory fails to give the value of the attachment
coefficient and of its variation with height
   /
7635
the collision frequency of electrons in the ionosphere  theoretical
analysis indicates that the electron collision frequency in the ionosphere
depends on the concentration of neutral particles in the d and
e regions and on the electron concentration in the f region  any
atmospheric model for the region above the e layer should not therefore
be based on the frequency of electron collisions with neutral particles
   /
7636
diurnal and storm time variations of geomagnetic and ionospheric
disturbance  analysis of records obtained at abinger and slough during
a period of months shows the diurnal variations to be very complex
with significant differences dependent on season and on activity
level  the hr component is important in both geomagnetic and ionospheric
phenomena but a component is found only in ionospheric f disturbance
the storm time variations of f and of horizontal magnetic force h
are statistically closely linked
   /
7637
the morphology of the ionospheric variations associated with magnetic
disturbance part variations at moderately low latitudes  graphs of
the ionospheric variations with local time and with storm time at
watheroo canberra and washington re given the local time variations
are mainly diurnal the storm time variations are appreciable for
about three days after the commencement of the magnetic storm and
the initial shape of the curve depends on the local time of the commencement
a theory of these variations is developed  all ionospheric
variations due to magnetic disturbance are attributed to the es field
produced by the auroral regions
   /
7638
an ionospheric disturbance index  a three hourly index with a range
based on the variation of the critical frequency and the height of
the f layers has been developed  a positive correlation of was found
between the lincoln indices and the amberley geomagnetic k indices
for the period between october and september  the seasonal variation
between the i and k indices was investigated and a comparison with
radio disturbance conditions made
   /
7639
on the variation of the f layer accompanying geomagnetic storms
the universal time dependent and local time dependent parts of the
variations of and during geomagnetic storms have been calculated
from data for several widely separated stations  the local time variations
appear to be due to the s current associated with the storm
no indication of a moving disturbance from the auroral zone was found
   /
7640
storm phenomena in the ionosphere  recent advances in our knowledge
of f layer ionospheric perturbations accompanying a magnetic storm
are summarized  the diurnal control is shown and differences between
phenomena at high medium and low latitudes are noted  for medium
latitudes the effect of a storm is to exaggerate the geomagnetic
distortion of the f layer already present
   /
7641
investigation of ionospheric absorption  comment on of june and authors
reply
   /
7642
radar echoes associated with lightning  echoes from thunderstorms
overhead and from distant storms were observed using radar pulses
operating on a wavelength of cm  the echoes from a storm overhead
frequently occur in pairs corresponding to reflections from cloud
layers at different heights
   /
7643
orientations of auroral displays in west central canada  a seasonal
variation of orientation was found by statistical analysis of observations
made at saskatoon in
   /
7644
radio reflections from aurora  echoes at and werre observed when
the auroral form exhibited some ray structure and then only from
parts of the aurora at elevations above the horizon  no echoes were
recorded at mcs  the echoes occur most frequently within the auroral
zone the echoes some distance south of it  it is suggested that echoes
arise by critical reflection from centres of high electron density
for echoes and cm for the echoes
   /
7645
scale height determinations and auroras  the method hitherto used
for determining scale heights from auroral luminosity curves is shown
to be invalid  the possibility of protons being responsible for the
production of aurorae is considered
   /
7646
the southern auroral zone as defined by the position of homogeneous
arcs
   /
7647
a study of a second order sampling servo
   /
7648
operating modes of a servomechanism with nonlinear friction
   /
7649
considerations on discriminators in airborne servo systems  discussion
of performance requirements for automatic pilot mechanisms
   /
7650
reduction of forced error in closed loop systems
   /
7651
the standardization of symbols and the arrangement of electronic
circuit diagrams  arrangement of circuit diagrams to give a clear
indication of the operation is advocated
   /
7652
relization of alternating current resistance  methods of realizing
resistance functions by arrangements of the partial fractions or
the continued fractions type are described  possible arrangements
are shown in two tables
   /
7653
geometrical transformation of impedance diagrams  in of september
please change the last word in the abstract to described
   /
7654
the effect of inductance on fine transfer between platinum contacts
an investigation was made with pt contacts in a circuit breaking
currents of the order of the circuit inductance was varied from to
measurements of the volume transferred and examination of the surface
structure indicate that there are two types of transfer true bridge
transfer independent of inductance and short arc transfer dependent
on the inductance
   /
7655
the behaviour of metallic contacts at low voltages in adverse environments
the problem discussed is that of obtaining a metal to metzl
contact mechanically when the contacts are contaminated by dust or
grease or are coated with films produced by absorption tarnishing
or corrosion  various types of contact are considered  principles
are outlined which provide a basis for design and testing a new technique
is described for the continuous dry lubrication of sliding contacts
in mechanical and electrical systems
   /
7656
long life contacts for unidirectional currents of amperes  an experimental
investigation was made of fundamental physical phenomena concerned
in the operation of contacts in vibratory converters the influence
of voltage and current on the direction of migration of material
was studied  long life was obtainable with pt contacts or with contacts
of dissimilar metals but on heavy duty an adequate life was obtained
only with w contacts in a low oxygen atmosphere
   /
7657
noise of metal contacts  measurements were made of the small voltage
fluctuation produced by the passage of direct current through ball
contacts  current values from to about were used and the influence
of contact resistance pressure and temperature was investigated for
steel copper and gold contacts  a possible mechanism accounting for
the results is suggested
   /
7658
design of unequal q double tuned transformers  equations and design
curves are given which should simplify calculations of certain of
the transformer characteristics
   /
7659
a turns index for pulse transformer design
   /
7660
transient conditions in a transformer supplying energy to a half
wave rectifier circuit  analysis is given for a simplified equivalent
circuit leakage reactance and core loss being neglected  experimental
results confirm the theory
   /
7661
the magnetic cross valve  further details are given of the device
previously described of and of its practical applications with circuit
diagrams and illustrations of the power ringers converting power
to and respectively
   /
7662
on the mechanics of magnetic amplifier operation
   /
7663
magnetic amplifiers of the balance detector type their basic principles
characteristics and applications
   /
7664
predetermination of control characteristics of half wave self saturated
magnetic amplifiers
   /
7665
bibliography of magnetic amplifier devices and the saturable reactor
art  a very comprehensive bibliography of published books articles
and patents for the period to mid
   /
7666
on the control of magnetic amplifiers
   /
7667
steady state and transient analysis of an idealized series connected
magnetic amplifier
   /
7668
series connected magnetic amplifier with inductive loading
   /
7669
the effective feedback ratio o of magnetic amplifiers
   /
7670
magnetic amplifiers of the self balancing potentiometer type
   /
7671
high speed magnetic amplifier
   /
7672
transient analysis of junction transistor amplifiers  in analysing
transistor operation transit time effects must be taken into account
this can be done to a sufficiently close degree of approximation
by including in the equivalent circuit an rc network in series with
an idealized delay line  only simple laplace transforms are then
involved in the response calculations  the theory is supported by
experimental results
   /
7673
pulse response of junction transistors  the case of low load resistance
is considered theoretically and experimental results are shown graphically
the response characteristics are discussed  good qualitative
and fair quantitative agreement was found between predicted characteristics
and those determined from pulse and ac measurements
   /
7674
the phase bistable transistor circuit  properties of transistor switching
circuits are discussed  a unit is described which comprises a
commutating ring of two transistors each connected as a one shot
multi vibrator the two being alternately triggered by a series of
clock pulses  the arrangement is used in a binary counter with a
clock pulse frequency of
   /
7675
a transistors in trigger circuits  a simple circuit using a single
transistor is described
   /
7676
low distortion transistor audio oscillator  design details of an
oscillator operating at any one of the four frequencies and and including
pnp junction transistors  series resistors are used to stabilize
emitter currents and a tungsten filament lamp to control amplitude
maximum available output is v  the low noise characteristics are
ascribed to the very narrow operating bandwidth
   /
7677
the common collector transistor amplifier at carrier frequencies
formulae are derived for th af operating parameters of the grounded
collector common collector circuit the variation of the transistor
current amplification factor with frequency is investigated the effect
of operating conditions on the cut off frequency ie the frequency
ie the frequency at which drops to of its af value is discussed
modified formulae are hence derived which are valid up to about experimental
results support the theory presented  point contact npn junction
and early pnp alloy transistors were studied
   /
7678
complementary symmetry transistor circuits under normal bias conditions
the current which flows in each lead to an electrode of a pnp transistor
is the negative of the corresponding current in an npn transistor
this is termed static symmetry the polarity of an input signal that
will increase conduction in a pnp transistor is the opposite of that
for an npn transistor this is termed dynamic symmetry circuits are
described that use static symmetry dynamic symmetry both types of
symmetry these include a stabilized direct coupled class a amplifier
with a voltage gain of a pulse circuit which converts a half sine
wave to pulses a class b power output circuit using four transistors
with overall feedback and giving a gain of about db when working
into a load and a television vertical deflection system with a class
b output stage connected directly to the deflection yoke
   /
7679
transistor theory and transistor circuits simple theory o for transistors
is developed from that for thermionic valves on the basis of the
duality principle and by comparison with the aperiodic retarding
field valve semidynamic rather than static characteristics are obtained
by biasing the collector by means of a resistor  these characteristics
can be converted to the usual static ones by a coordinate transformation
parameters are measured by means of a transistor bridge equivalent
to that used for obtaining the dyn mic characteristics of a thermionic
valve  the parameters found are related to the constant current values
of the parameters hitherto used  simple formulae are derived for
the voltage and power amplification of grounded base and grounded
emitter circuits use of the negative static resistance o a grounded
emitter transistor for measuring the resonance resistance of oscillatory
circuits is discussed
   /
7680
push pull transistor amplifiers  a description is given of a practical
af power amplifier us  ng point contact transistors and developed
from the class b thermionic valve amplifier by appli  ation of the
duality principle  this amplifier  an deliver at harmonic distortion
   /
7681
equivalent circuit diagrams of the transistor  different representations
for transistors are derived from the equivalent circuit of the nonreversible
quadripole of a two valve circuit a one valve circuit with
a lossless transformer
   /
7682
transistors theory and application part equivalent transistor circuits
and equations  relations between transistor parameters circuit elements
and performance are derived by application of kirchhoffs mesh equations
for the transistor equ  valent circuit  part of november
   /
7683
theory of afc synchronization  correction to paper noted in of november
   /
7684
febrication of radio frequency micropotentiometer resistance elements
stable low resistance disk type resistors are required for the bureau
of standards rf micropotentiometer previously described of  various
processes for forming thin  ilm resistors are considered  three methods
are described by which it is possible to produce resistors are considered
three methods are descri  ed by which it is possible to produce
resistors stable to within viz high temperature firing ev  porating
and plating use of disks cut from sheets of carbon film deposited
on bakelite  a chemi  al reduction process is under investigation
   /
7685
copper eddy current losses in coils with car  onyl iron and ferrite
cores  the design of low loss short multilayer coils and long single
layer coils is considered  because core losses are much reduced with
modern ferrite cores the relative importance of the copper eddy current
losses  s greater  these losses and their dependence on the coil
and core parameters are discussed in detail
   /
7686
saturable reactors with inductive dc load part steady state operation
   /
7687
distribution of conductivity within dielectric films on aluminium
frequency and formation voltage characteristics were determined for
a ac  capacitor with an anodized al anode al cathodes  nd electrolyte
consisting of boric acid and bor  tes in the range  an equivalent
circuit is given and a model is suggested consisting of a layer dielectric
film one layer adjacent to the metal surface having low conductivity
low power loss  independent of frequency but dependent on the pe
k formation voltage the other film with opposite properties
   /
7688
triode transformation groups  the properties of the six networks
including respectively the six possible transmission paths through
a triode valve of are shown to be interrelated in such a way that
given the characteristics of any one o  the circuits those of the
remainder are obtain  ble by a routine transformation process
   /
7689
potential analog network synthesis for arbitrary loss functions
a method of network design  s described in which the appropriate
potential problem is formulated on the basis of a given loss function
by introducing continuous charge distribution on the complex frequency
plane  the technique of charge quantization is used to find the
natural modes of the network function
   /
7690
feedback theory some properties of signal flow graphs  the equations
characterizing transmission systems may be represented by networks
of directed branches termed signal flow graphs the branches terminate
at nodes which represent repeater stations  the topology of these
diagrams is studied with particular reference to feedback circuits
the technique is illustrated by application to specific circuit design
problems
   /
7691
two theorems on two terminal electrical networks  given that the
impedance of the network is a rational function zs of the complex
frequency and putting it is shown that for networks consisting of
reactances only and resistances together with reactances of one kind
   /
7692
modified exponential line as improved transforming element with high
pass characteristic  for a given length of exponential line there
is a critical frequency above which the transformation property becomes
effective at frequencies only a little above critical the transformation
is only approximate  this drawback can be avoided by designing the
line so that the characteristic impedance does not vary exactly exponentially
approximate line equations are derived for this case and
practical forms of such lines are discussed the influence of constructional
defects is examined
   /
7693
a general definition of pass band
   /
7694
rlc lattice networks  a method for synthesizing open circuited lattice
networks to have a required transfer impedance is based on the partial
fraction expansion of the given function  no mutual inductances are
used and series resistance is associated with all the self inductances
so that low q coils may be used  a numerical example is worked out
   /
7695
synthesis of paralleled terminal rc networks to provide complex zeros
in the transfer function  an improvement n the method given by guillemin
of is described which required fewer paralleled networks  the desired
transfer ratio is converted into the sum of several transfer ratios
each of which can be realized with a single ladder network  a method
of synthesis for these networks in terms of a common driving point
admittance function is described and theory developed for their connection
in parallel
   /
7696
the dual input parallel t network  the frequency of maximum attenuation
in this type of circuit is a function of the ratio of the two input
voltages various potentiometer drive arrangements can be used for
external tuning over a wide frequency range  experimental results
for a circuit with dual potentiometer input are in good agreement
with theory
   /
7697
synthesis of the transfer function of terminal pair networks
   /
7698
the possibility of defining the width of the pass band in terms of
the distortion of a transient  analysis using the definition previously
given indicates that it is impossible to define the distortion of
a transient by a single build up time
   /
7699
an approximate graphical analysis of the steady state response of
nonlinear networks  an approximate graphical analysis is given for
the case when one of the circuit parameters is varied gradually
transients and the generation of subharmonics are not dealt with
the networks investigated consist of a nonlinear iron cored inductor
with a linear resistor and linear capacitor  the results of the analysis
can be applied to the investigation of the effects of resistive or
reactive loads of magnetic amplifiers and the utilization of jump
phenomena ferroresonance effects in switching devices
   /
7700
a theorem on the impedance transforming properties of reactive networks
two circle transformations derived from the impedance transformation
properties of a terminal network are used to develop a circle locus
theorem which considerably simplifies analysis of impedance matching
networks  it is applicable to any linear reactive network with any
arbitrary reference impedance not lying on the reactance axis
   /
7701
an approximate method of obtaining the transient response from the
frequency response  the method is based on expressing the transient
response in terms of the real part of the frequency response function
which is plotted on a logarithmic frequency scale and approximated
by a series of straight line segments  a is calculated from the slopes
of these segments
   /
7702
concerning the minimum number of resonators and the minimum unloaded
q needed in a filter  the number of resonator elements required to
meet given specifications of filter characteristics and the lowest
no load values of q which the resonators may have can be deduced
from the formulae and graphs given  the specifications include the
accept and reject bandwidths the peak valley ripple ratio and response
in the reflect band of the selective circuit  both constant k and
m derived types of filter are considered and numerical examples are
worked out
   /
7703
wave filter characteristics by a direct method  full paper
   /
7704
audio frequency filters using negative feedback the operation is
described of a two valve amplifier with a series resonance circuit
across the cathode impedance of each of the two valves and a parallel
resonance circuit in the anode circuit of the first valve  a band
pass filter with a flat topped response curve is obtained by adjusting
the resonance frequency of the cathode circuit of the second valve
to be intermediate to the cathode circuit and anode circuit resonance
frequencies of the first valve
   /
7705
nonlinear multipoles  a conceptual scheme is outlined which is intended
to be used in conjunction with theories of oriented graphs and with
machine computers for the analysis and design of nonlinear networks
a system of classes of nonlinear multipoles is defined the classes
being characterized by their responses to a particular set of pulses
see also of september
   /
7706
the national radio components exhibition  review of a selection of
exhibits in the sections allotted to valves miscellaneous components
and accessories and measurement instruments at the exhibition held
in paris february march
   /
7707
printed circuits and the automatic factory  discussion of the application
of the auto sembly technique of february danko to u quantity production
of a wide variety of electronic equipment with substantial reduction
of costs and economy in skilled personnel
   /
7708
frequency feedback  discussion of a phenomenon which occurs in all
resonant systems possessing a relation between resonance frequency
and amplitude in such systems there may be an external feedback channel
or internal feedback due to nonlinear reactors or to nonlinear resistors
combined with fixed reactors as in the so called rx modulators  the
phenomenon shows itself in asymmetrical deformation of the resonance
curve  applications of the effect in a m fm conversion and in fm
conversion for frequency shift reception are noted
   /
7709
a method of evaluation of the quasi stationary distortion of fm signals
in tuned interstages  a graphical approach to the problem of designing
low distortion f circuits making use of the normalized derivative
of the phase frequency function is shown to be preferable to that
using the phase frequency curve itself  the principles are applied
to the determination of the distortion factor of a single tuned circuit
interstage and of a cascade arrangement of three stagger tuned resonant
circuits
   /
7710
transient phenomena in an oscillator circuit with variable inductance
the operation of the circuit is discussed and a formula is derived
for determining the variation of the current in the circuit  a numerical
example is given
   /
7711
high frequency crystal units for use in selective networks and their
proposed application in filters suitable for mobile radio channel
selection  the design of bevelled at type quartz plates for use in
band pass crystal units is described  the reduction of unwanted modes
of vibration including thickness shear overtone modes is considered
approximate electrical data for plated circular at type quartz plates
with all unwanted modes reduced to a level db below the response
of the main thickness shear mode are tabulated  the design is considered
of a crystal filter with a mid band frequency of and bandwidths of
and respectively at the and points
   /
7712
thickness vibrations of piezoelectric crystal plates  addendum to
work noted in of february
   /
7713
a simple method of coupling toroidal coils  theory is given of a method
of coupling suitable for the low values of coupling coefficient usually
required for if transformers fm discriminators and in some types
of filter  the coupling coils with very few turns are wound on a
separate toroidal core each being connected in series with one of
the toroidal coils to be coupled  in a simplified version a coupling
coil of one or two turns connected in series with one toroidal coil
is wound on top of the other toroidal coil  such a transformer may
be accommodated in a cube with the toroids close together with no
shield between them
   /
7714
electromagnetic waves in hollow metal cylinders with circular cross
section  the object of the paper is to coordinate the treatment of
the subject and to clarify some points  the electric and magnetic
lines of force are mapped in perspective  other diagrams show the
distribution of poynting vector over the cross section and the currents
in the walls  wave propagation in concentric lines is investigated
   /
7715
nonlinear electromechanical systems  by an extension of lienards
graphical method abstracts only two or three coplanar curves need
be traced for a complete topological study of the stability conditions
for systems represented by equations of the types  results of a detailed
analysis are applied to the case of a filtered oscillator of may
and of june  a much shorter version of the first part of this paper
was given in paris
   /
7716
a study on the triggering of a plate coupled multivibrator by negative
pulses  experimental observations showed that voltage waveforms at
different electrodes were markedly influenced by the form of the
input pulses that triggering action depended largely on the input
pulse amplitude that triggering might not take place for either very
small or very large pulse amplitudes depending on circuit arrangement
but larger amplitudes caused greater difficulties  analysis of the
circuit response to pulses of various durations and amplitudes gave
results supporting the observations
   /
7717
design of triode flip flops for long term stability  description
of an analytical method of design based on considerations of dc stability
limiting tolerances in respect of voltage and component values
being taken into account initially  an eccles jordan circuit with
injection diodes is considered as a general case and equations are
derived expressing the operating conditions in the grid and the anode
circuits  solution of these equations gives appropriate key values
the method is applied to three special cases and a numerical example
is given
   /
7718
wide band data transmitter  a fm oscillator uses a double phantastron
circuit of close and lebenbaum for a linear data recording system
signals in the range can be handled with an accuracy to within  full
circuit details are given
   /
7719
stable frequency dividers using thyrite elements  locked oscillator
frequency dividers using nonlinear thyrite elements as load impedors
are described  with slight circuit modifications a stable locking
action is obtainable for division by any number between and  no circuit
adjustments are required as the valves age  dividers have been constructed
for frequencies up to
   /
7720
vibrating wire high q resonator  resonator units are described in
which a wire of high tensile strength is stretched between long pole
pieces maintaining a strong transverse magnetic field  resonance
occurs when the frequency of current sent through the wire coincides
with the natural frequency of the system  theory is given and the
equivalent electrical circuit analysed  with a tungsten wire mounted
in vacuo a q value of has been obtained at kcs  applications of such
devices in filters and for frequency control are noted
   /
7721
spurious frequency modulation in signal generators  the chief cause
of fm in an am circuit is the variation of valve input capacitance
with modulation methods of reducing this effect are examined  two
circuits effective in reducing fm at vhf are described an untuned
class a amplifier with grid modulation a voltage dividing network
containing a crystal diode suitably biased to act as resistance
   /
7722
valve matching using resistors  desired characteristics can be obtained
by including resistors in series and or parallel with a valve formulae
for the effective parameters are tabulated for several simple combinations
matching of ac characteristics may in practice be accompanied
by reasonable matching of the overall dc characteristics a circuit
is shown using the latter effect for determining resistances required
for matching two valves
   /
7723
a general circle diagram for the input admittance of a grounded grid
disk seal triode  the method given takes account of the transconductance
and anode cathode capacitance of the triode the effect of the transconductance
phase which depends on the electron transit time is shown
in the diagram  a numerical example is given  see also of november
   /
7724
cathode follower design charts  output impedance input voltage charts
are shown for commonly used valve types  design procedure is outlined
   /
7725
on the faithful reproduction of the flat top of a pulse in a high
fidelity pulse amplifier  the pulse amplifier analysed comprises
a pentode with rc coupling circuits  two methods of determining anode
current and hence amplifier response are applied the one based on
the overall amplification reduction due to voltages across the parallel
rc screen circuit and the rc cathode circuit the other based on the
superposition principle correction of pulse top distortion is achieved
by the anode supply rc decoupling circuit the conditions for satisfactory
correction are derived
   /
7726
a modern broadcasting pre amplifier  description of a simple stage
feedback amplifier using type low noise pentodes and suitable for
use with sound reproduction equipment distortion is low gain practically
uniform from to and pick up of stray fields effectively negligible
   /
7727
harmonic distortion and negative feedback  authors reply to comment
by kerr of november
   /
7728
use of ferromagnetic materials in electronic tuning of radiofrequency
components  the change of the incremental permeability of a core
of ferrite material due to a secondary superimposed magnetic field
is discussed  the effect is utilized in the design of toroidal inductors
whose inductance can be varied by altering the current in an auxiliary
winding  inductors of this type are incorporated in a receiver tunable
from to with a bandwidth of at and of at  the power required in the
auxiliary tuning coil is  a variable inductor has been developed
whose volume is wi weight slightly and tuning range for applied power
of in the frequency band falling to in the band  see also electronics
   /
7729
the relation of the quantum theory to the theories of gravitation
and electromagnetism and an application to the theory of the electron
   /
7730
on an iterative method for nonlinear vibrations  analysis of a method
giving results analogous to those obtained by duffings method
   /
7731
high frequency electrical measurements  conference in washington
dc
   /
7732
a new property of dimensional fields  mapping of the field inside
a nearly enclosed area is facilitated by working on the correlative
field whose derivation is explained  an analytical proof of the correlative
property based on the schwartz christoffel transformation is
given in an appendix  the proof is due to wr smythe  for a digest
see
   /
7733
the derivation of vector potential from tables for scalar potential
   /
7734
field strength and temperature studies of electro luminescent powders
in dielectric media  measurements were made on electroluminescent
cells using zns se cu phosphor dispersed in a thermo plastic matrix
the intensity of luminescence depends critically on the field in
the phosphor and hence on its dielectric constant but does not depend
on the dielectric properties of the matrix except in so far as the
latter provides a means of supporting a strong field in the phosphor
little change of luminescent intensity was observed when the temperature
was varied from to polystyrene being used as matrix
   /
7735
dielectric changes of electroluminescent phosphor during illumination
measurements were made of the dielectric properties of electro luminescent
films composed as described previously above for different values
of applied voltage at and for various wavelengths and intensities
of illumination  the dielectric constant depends markedly on the
illumination the magnitude of the variations depending critically
on the applied voltage  the effect exhibits a maximum at about
   /
7736
development of the electrical resistance of thin films of platinum
subjected to a relatively high direct voltage  measurements made
on films of different thicknesses before and after the application
of voltages of or indicate that the resistance is increased decreased
or unchanged depending on the amount of heat developed which in turn
depends on the initial resistance and hence on the thickness
   /
7737
on pre exponential factors in formulae for ionic conductivity in
solids  it if in formulae for equilibrium constants and rate constants
ener  y is assumed to be proportional to temperature the factor preceding
the exponential term is not increased by a factor exp being a
constant and boltmanns constant but by a factor involving entropy
   /
7738
initiation of discharges at electrical conta  ts  the experimental
investigation described deals with discharges between low power contacts
w  th special attention to the cases of make and break at medium
voltage  the discharges were found to be initiated by a cold field
emission of electrons govenred by the nature of the surface tarnish
layers  the influence of the gas atmosphere was examined  a theory
of the mechanism is outlined
   /
7739
on the nonoptical theory of focusing in rotating magnetic fields
the difficulties arising in the application of optical methods to
electron optics are pointed out  the general theory of t  e focusing
action of static magnetic fields developed by grinberg which is based
on nonoptical methods is applied to the case of paraxial electron
beams in rotating magnetic fields
   /
7740
measurement of secondary electron emission  the sources of error
in secondary electron emiss  on determinations are discussed in detail
retarding voltage curves obtained experimentally are analysed and
a method of calculating the proportion electron current is given
for the cz case w  en the target and spherical collector are made
of the same material  for a cr ni alloy and a pr  mary potential
of this proportion is
   /
7741
experiments on radiation by fast electron be  ms  the design of a
magnet system for an undulator in which the field direction alternates
periodically along th electron path of is described  a electron beam
from a linear accelerator was p  ssed through the system light radiated
by the beam was determined  using a small linear accelerator with
good bunching action and beam energy r  diation at wavelengths below
was observed peak power output was  millimetre waves were also generated
in the accelerator tube
   /
7742
graphs for a rapid calculation of the work function of thermionic
emission  a set of graphs is given for the saturation current density
as a function of absolute temperature with the work  unction as parameter
the use of the graphs is explained
   /
7743
dimensional analysis units and rationalization  careless manipulation
of dimensional formulae can lead to fallacious results  the trouble
is due to the use of the multiplication sign for two different kinds
of products having very different physical meanings  once these are
clearly distinguished and the phsy physical meaning considered at
every stage in the proceedings the diff  culties encountered even
with rationalized units are overcome
   /
7744
antiferromagnetism  a survey paper  the distinction between antiferromagnetism
and ferrimagnetism is indicated the former is found mainly
in simple inorganic compounds the latter in complex compounds  problems
discussed concern the interaction between adjacent dipoles the different
possible arrangements within the various lattices the magnetic properties
and the phenomena of the transition from order to disorder
   /
7745
a theory of ferromagnetism  a theory is formulated that when applied
to iron making use only of spectroscopic data for the fe atom gives
a value of bohr magnetons for the saturation magnetic moment per
iron atom and a value of for the curie temperature  these values
are in reasonable agreement with the experimental values of magnetons
and
   /
7746
the calculation of the magnetizing force  full details of the method
described in f of
   /
7747
the electromagnetic properties of a plane grating  a plane grating
is considered which consists of a number of parallel conducting planes
between which electron streams pass and its waveguide properties
are discussed taking into account the velocity scatter of the electrons
a general solution of the problem is given for an arbitrary type
o of scatter function  the velocity scatter narrows the range of
average velocities of the streams for which amplification is possible
and displaces it towards the higher velocity values the maximum amplification
is also reduced
   /
7748
propagation of electromagnetic waves in a transp rent periodically
stratified space  equations derived for the general case are applied
to the special case of a pile of double layers of equal optical thickness
   /
7749
transmission of electromagnetic waves through pairs of parallel wire
grids  an analytical solution is obtained for the power transmission
coefficient of a double grid system  transmission coefficients are
plotted as functions of the integrid spacing for different wire spacing
and angles of tilt  the curves are compared with those obtained by
measurement at cm using wire of radius cm  agreement is good until
the wire spacing approaches  reasons for this divergence are noted
   /
7750
plasma oscillations in crossed electric and magnetic fields  an idealized
case is considered and the specific structure which retards the
em waves is replaced by a medium with an effective dielectric constant
greater thn than unity  it is also assumed that the constant charge
and current of the electron beam are compensated by the charge and
current of ions which do not participate in the hf oscillations
with these assumptions conditions are determined under which the
electron beam becomes unstable the fluctuations of the velocity and
density of the beam increasing indefinitely
   /
7751
extension of fermats principle to group propagation time  continuation
of work noted in of  it is shown by analysis that the difference
between the group propagation times for two real paths joining the
same two points is zero
   /
7752
amplification of microwave radiation by substances not in thermal
equilibrium  methods are discussed for the production of a nonequilibrium
energy distribution and the amount of amplification which may
possibly be obtained by this method is calculated
   /
7753
new techniques in radio astronomy
   /
7754
extrapolation of sunspot climate relationships  consideration of
the periodicity of sunspot number variations is based on taking the
maximum year as the middle one of three successive maximal years
the next maximum should occur in and should be a strong one
   /
7755
nonradiative natural oscillations of a conducting sphere so surrounded
by a layer of air and an ionospheric sheath  a theoretical investigation
having special reference to em oscillations of the earth and relevant
to the study of atmospherics  the dependence of the oscillation frequencies
on the air layer thickness and on the plasma properties are
analysed  the lowest natural frequency to be expected for earth oscillations
is about  oscillations of low frequencies are reflected at
the inner surface of the plasma while higher order oscillations may
penetrate right through the plasma and radiate into space
   /
7756
damping of the natural electromagnetic oscillations of the system
earth air ionosphere  continuation of work noted in above  an approximate
formula is derived for the damping of the lowest frequency oscillations
from which the effective height of the air layer and the effective
conductivity of the ionosphere can be determined
   /
7757
electron density in the upper atmosphere and interpretation of the
hf curves of ionosphere virtual height  for the case of vertical
incidence and the geomagnetic latitude of rome an expression is developed
for the group refractive index using appletons formula  absorption
is neglected  the optical path of em waves totally or partially reflected
or transmitted through an ionosphere layer is determined as a
function of frequency for various cases  the results are applied
in conjunction with experimental hf curves to derive linear relations
giving directly the thickness of the layer and its height above the
ground  cases of single and superposed layers are treated
   /
7758
instrumentation for measuring changes in phase of ionospheric echoes
changes in carrier phase of ionosphere pulse echoes are determined
from a comparison of the transmitted signal stored by a memory circuit
with the echo signal received  the phase variation is presented in
the instrument described on a cro and a continuous photographic record
is obtained  the equipment used is similar in principle to that of
findlay of  results of e region observations at have been published
by davids
   /
7759
cozi communication zone indicator  a general description with block
diagram of timing and indicating circuits is given of a low power
oblique incidence ionosphere sounder designed to indicate skip distances
and communication zones from to operation is on any one of six pre
set frequencies in the range peak pulse power pulse duration and
repetition frequency sec  the one hop skip distance is obtained directly
from the time lag of the back scatter from the ground after single
reflection from the ionosphere  typical oscillograms show the increase
of skip distance as the carrier frequency is increased in steps from
the complete series of records two at each frequency being obtained
in min
   /
7760
synthesis of feedback control systems by means of pole and zero location
of the closed loop function  a mathematical description of the desired
frequency response based on the location of the poles and zeros of
the closed loop function is given which ensures that the specifications
of velocity or acceleration error constant bandwidth and relative
stability will be met and which provides for acceptable system transient
response  algebraic manipulation yields the transfer function of
the main loop and subsidiary feedback loop corrective networks required
to meet the specifications
   /
7761
servomechanism transient performance from decibel log frequency plots
discussion
   /
7762
sampled data control systems studied through comparison of sampling
with amplitude modulation
   /
7763
stability of varying element servomechanisms with polynomial coefficients
   /
7764
an improved magnetic servo amplifier
   /
7765
current and voltage regulators  a review of the principles of various
types of regulator utilizing a reference standard  systems for low
and high power and for direct and alternating current or voltage
are considered
   /
7766
an electromechanical ac line voltage stabilizer  description of a
stabilizing unit having a short recovery time comparing favourably
with that of commercial electronic devices  a temperature limited
diode in a bridge circuit is used to detect the line voltage variations
and is followed by a phase inverter and a thyratron driving circuit
   /
7767
recent developments in the field of electric cells  improvements
in leclanche type cells are reviewed and the construction and properties
of ag mg cells with ag cl depolarizer c zn cells with hgo depolarizer
are described
   /
7768
the silver zinc accumulator  construction details are described and
performance figures given  types are available with capacities from
to the corresponding weights ranging from oz to oz  the temperature
limits of operation are discussed
   /
7769
geographic and temporal distribution of polar blackouts  tabulations
of hourly values of the ionospheric parameters for northern hemisphere
stations have been used to derive diurnal variations in the occurrence
of blackout no echo conditions  contour plots are presented showing
the diurnal average percentage of time during which blackout conditions
prevailed the amplitude of the diurnal variation and the time of
maximum frequency of occurrence  changes in the contours with season
and with magnetic activity are discussed
   /
7770
ionosphere review  evidence indicates that the sunspot minimum had
occurred before the end of  the latest sunspot cycle exhibited the
asymmetry characteristic of cycles with high maximum the increasing
phase lasted months and the decreasing phase about months smoothed
sunspot number and critical frequency curves show close correlation
the increase of muf at sunspot maximum is greatest for winter day
and least for winter night  frequencies over appear to have been
usable for long distance communication during four winters around
the sunspot maximum
   /
7771
upward stepped leaders from the empire state building  a new interpretation
is presented of the observations reported by mceachron of
   /
7772
observations on the negatively charged column in thunderclouds
   /
7773
doppler shifted radio echoes from aurora  note on the results of
an experiment in which alternate pulsed and cw signals at were transmitted
northward from a transmitter  signals recorded at a receiver
miles away with aerial beamed north showed a doppler frequency shift
upward or downward correlating respectively with homogeneous and
rayed structure both shifts may be recorded simultaneously
   /
7774
very low frequency noise power from the lightning discharge  present
knowledge about the lightning discharge mechanism is reviewed particular
attention is paid to the theory of bruce and golde of computed power
spectra of a nearby cloud to ground flash and a distant daytime atmospheric
are compared taking propagation effects into account of  the
results confirm the presence of a peak at about in the spectra of
the distant atmospherics
   /
7775
an equalizing network for carrier type feedback control systems
the analysis of an active high q rlc circuit shows that it permits
lag compensation of carrier type feedback control systems through
direct operation on the system actuating signal  the use of this
circuit in an instrument type velocity servo reduces the steady state
error by a factor of at least
   /
7776
the minimum moment f of error squared criterion a new performance
criterion for servo mechanisms
   /
7777
the behaviour of a remote position control servo mechanism with hard
spring non linear characteristics
   /
7778
radioactive and photoelectric pn junction power sources  an electrical
power source can be made by exposing a pn junction to radioactivity
or light so that the junction field separates electron hole pairs
produced by the radiation  expressions for maximum power optimum
load resistance and efficiency are derived from an equivalent circuit
and rectification theory  power and efficiency increase with source
current of separated charges and zeros bias junction resistance
increases with energy and intensity of radiation but is limited by
self absorption in the radioactive isotopes  estimates of z attainable
power and efficiency for silicon cells are watt cm and percent for
solar radiation averaged allowing for night weather and varying angle
of incidence and watt cm and percent for beta radiation from of activity
curie g  however lattice defects produced by beta radiation impair
cell performance by increasing electron hole recombination a theoretical
estimate of threshold energy for radiation damage in silicon is about
about half the experimental value reported for germanium  avoiding
radiation damage by annealing by absorbers and by use of less energetic
isotopes is discussed  the y beta spectrum is given it is used in
estimating damage rates in germanium which are high and efficiencies
obtainable with absorbers which are low  theory and experiment are
compared for cells of silicon and of germanium
   /
7779
an rf source of heater power for low level audio frequency amplifiers
details are given of a simple and compact oscillator having a rated
output of at
   /
7780
a new self excited square wave transistor power oscillator
   /
7781
transmission by sun power achieved  successful communication at over
a distance of about miles using a se photocell powered transistor
transmitter is reported  the power unit consisting of photocells
illuminated by sunlight is described
   /
7782
stabilized dc supplies using grid controlled rectifiers  circuits
using magnitude controlled thyratrons are discussed these are suitable
for hv power supplies where the load is reasonably constant and the
output voltage regulation is not required to be better than within
about  a unit incorporating two type miniature thyratrons can supply
at
   /
7783
wide range operation of grid controlled rectifiers  a method of controlling
thyratron conduction over a wide range from a dc control signal
is described and the steady state characteristics of a dc power amplifier
employing this method of control in a bi phase rectifier circuit
are discussed and experimental results t given
   /
7784
an alternating voltage stabilizer  a unit designed to give an output
of varying by for line voltage changes of frequency changes and load
variations from to includes provision for correction of form factor
by simultaneously stabilizing the rectified mean and rms voltages
   /
7785
a textbook of servomechanisms
   /
7786
an autocorrelogram computer  a comparatively simple and inexpensive
instrument is described with detailed circuit diagram  the signal
recorded on a magnetic tape is played back through two separate heads
thus producing the functions and these are amplified multiplied and
then integrated by a modified dc watt hour meter  the computer was
originally developed as a yarn cross section analyser
   /
7787
frequency analysis of computer systems
   /
7788
australian guided weapons analogue computer  brief description of
agwac whose design is based on that of the royal aircraft establishment
simulator tridac  the equipment is built up of plug in units bricks
   /
7789
differential analyser the npls new analogue computer for solving
differential equations  brief description of a large analyser recently
brought into use  the machine i actuated by a motor driven shaft
representing the independent variable  the three principal types
of mechanism used are integrators ger trains and differential gears
function tables permit an arbitrary function of any variable to be
inserted from the graph and also allow solutions to be obtained in
graphical form  setting up time is low since all units are coupled
by means of servomechanisms which may be connected in any combination
through a telephone type switchboard
   /
7790
algebraic method of synthesis of multi contact relay systems  a vector
algebraic method of synthesis of switching circuits suitable for
computers is developed theoretically
   /
7791
note on the resistance network analogue solution of field problems
f spherical symmetry  results of a previous paper of april are applied
to the derivation of design formulae for a resistance chain analogue
for solving the equation div k grad u in cases of spherical symmetry
   /
7792
bibliography on ultrasonic delay lines
   /
7793
current fluctuation phenomena in current carrying sliding contacts
an account is given of an experimental investigation of sliding contacts
as sources of interference voltages  the dependence of the noise characteristics
on sliding speed and current intensity is examined  most
of the observed phenomena have a thermal origin  several ranges of
operation involving different mechanisms are distinguished
   /
7794
odd integer magnetic frequency multipliers  for various applications
in the frequency f range  frequency multiplication can be performed
more efficiently by magnetic than by electronic equipment  the operation
of the magnetic m  multiplier is analysed and experimental units
are described  for higher multiples multistage arrangements are preferred
harmonic distortion can be kept low by suitable choice of core
materials
   /
7795
component design trends new relay materials improve performance
tungsten carbide contacts nickel iron armatures stain less steel
springs silicone damping fluids and self shielded cores are among
the materials discussed
   /
7796
flip flop counter has expanded range  design procedure is indicated
for counter having up to six stable states without using feedback
or matrixing  long term reliability is a primary objective crystal
diodes are used in cross coupling networks
   /
7797
junction transistor switching circuits  a transistor experimental
switching system includes blocking oscillator multivibrator flip
flop gating and adding circuits
   /
7798
a method of designing transistor trigger circuits
   /
7799
the behaviour of polystyrene capacitors under alternating voltage
experiments at are reported  the main conclusions reached are heat
treatment has no adverse effect on life for a given value of applied
voltage the life is shortened if the voltage gradient is increased
for a given ratio between applied voltage and initial ionization
voltage the life is considerably shortened if ambient temperature
is raised  certain considerations regarding the impregnation of capacitors
with mineral oil are discussed
   /
7800
discoidal vs tubular feed through capacitors  tubular and disk type
ceramic feed through capacitors for filtering purposes are compared
in respect of their coupling impedance and its frequency dependence
the disk type is superior as regards hf performance and mechanical
ruggedness  the necessary improved shielding methods are described
   /
7801
interesting applications of transistor technique  circuit diagrams
and photographs are presented of various applications including an
af amplifier moulded inside a record player pickup arm
   /
7802
practical circuits using transistors  diagrams and descriptions of
operation are given for amplifiers oscillators and switching circuits
   /
7803
integrated microwave circuits  use of a milled block constucting
for producing microwave assemblies is shown to offer advantages over
more usual waveguide assemblies
   /
7804
a definition of passive linear networks in terms of time and energy
   /
7805
thermodynamic consideration of electromagnetic cavity resonators
a simple method is presented for calculating the shift of resonance
frequency produced by introducing a foreign body into the cavity
   /
7806
tunable cavity for x band oscillators  a rectangular waveguide tuner
for external cavity reflex klystrons is described
   /
7807
equivalent circuit for a passive nonreciprocal network  a nonreciprocal
quadripole is considered comprising an ideal amplifier and phase
shifter  compared with the gyrator representation this method facilitates
the linking of the network parameters with measurements
   /
7808
behavior and applications of ferrites in the microwave region  both
reciprocal and nonreciprocal devices comprising ferrite loaded waveguides
are studied the nonreciprocal effects in the latter being based
on bire fringence phase shift field displacement and coupling through
apertures as well as on rotation of polarization  a method called
point field analysis facilitates qualitative investigation  definitions
are given of the gyrator the isolator and the circulator  performance
of some experimental devices is reported
   /
7809
an investigation of the nonlinear distortion of a quadripole using
a continuous spectrum signal  fo measuring the nonlinear distortion
introduced by an af transmission system it is necessary to use a
continuous spectrum of frequencies with a given shape of the envelope
relations are derived from which it is possible to calculate the
spectra at the output of certain nonlinear systems for input signals
covering a continuous band of frequencies and having envelopes represented
by an exponential function or a difference between two exponential
functions  as compared with tests using one or two spot frequencies
the results so obtained are more in accordance with results of subjective
listening tests
   /
7810
the theory and design of gas discharge microwave attenuators  the
theory of the interaction between a dc gas discharge and an rf field
is considered and expressions developed for the complex conductivity
of the discharge  the simple lorentz theory is shown to give values
of complex conductivity not very different from those derived with
more detailed analyses  problems connected with the gas discharge
including that of noise production are considered  practical microwave
attenuators developed by the authors are described in detail  two
main classes of device are considered devices with resonant structures
and distributed devices
   /
7811
vacuum fluctuation noise and dissipation  continuation of previous
investigation of the interaction of an electron beam with the field
in an enclosed region  an expression is derived for the observable
mean squared emf and is used to calculate the fluctuations induced
in the beam when interacting with a damped oscillator  as the damping
becomes very large the fluctuations approach zero
   /
7812
cathode follower coupled phase shift oscillator  a note on the advantages
of using cathode follower amplifiers between the sections of the
phase shifting network
   /
7813
circuits for producing high negative conductance  several arrangements
using two triodes are illustrated negative conductances of the order
of can be produced  stable oscillators can be made to operate with
a supply voltage of or less
   /
7814
the regenerative pulse generator  pulses are circulated repeatedly
in a feedback loop including an expander and a filter being alternately
shortened in the expander and lengthened in the filter and giving
an output at each traversal  a loop gain of unity is maintained by
agc  for microwave pulses the nonlinear expander characteristic may
be obtained by means of a crystal  microwave pulses of duration down
to and dc pulses down to have been produced  possible applications
include communications radar and measurements were coherent pulse
trains are required
   /
7815
a versatile pulse shaper  a triggered miniature thyratron circuit
is described for deriving sharp pulses with uniform amplitude and
duration from an input of nonuniform pulses  a table shows the output
waveform for various circuit arrangements and component values
   /
7816
frequency multiplication by regenerative modulation  a multiple frequency
generator is discussed in which operation depends on mixing a
feedback and an input voltage  theory is presented for a circuit
designed to produce four multiples of the input frequency experimental
confirmation of the results is reported  multiples up to the have
been obtained with good amplitudes maximum amplitudes can be arranged
to fall in desired frequency ranges  even and odd multiples can be
made available at separate output terminals  operation is unaffected
by variations of anode filament or input voltage or by phase shifts
due to aging of components in the feedback loop
   /
7817
effect of steepness of rise and fall of the input pulse on the response
of pulse amplifiers  the response of shunt compensated amplifier
to ramp function and triangular pulses is analysed
   /
7818
a stable and sensitive dc amplifier with high input resistance  a
line operated dc amplifier for automatic regulation using ac amplification
and a breaker modulator has been designed with the following
characteristics direct reading instrument zero drift after warming
up les than peak to peak in hours test sensitivity short time stability
usually input resistance and damping about sec with source resistance
   /
7819
new amplifier has bridge circuit output  the basic circuit is described
and complete circuit diagrams are given of and af amplifiers  the
advantages of the circuit include absence of switching transients
absence of dc current through primary of output transformer and low
quiescent current
   /
7820
differential amplifier design  the possibility is discussed of providing
good rejection of in phase signals without using a balancing adjustment
or specially selected components  to achieve the desired result by
use of in phase negative feedback care must be taken that the feedback
and input voltages are correctly combined  two circuits combined
two circuits are described illustrating the principles v involved
both have the disadvantage of requiring floating batteries and isolated
heater supplies
   /
7821
the possibility of adjusting the internal impedance and varying the
gain in amplifiers with combined current and voltage feedback  the
internal impedance can be reduced to and maintained at any desired
level r inc independent of the gain or the amount of feedback by
using a fixed amount of the total feedback to achieve the impedance
reduction and apportioning the remainder so that where r and k are
the current and voltage feedback factors of this remainder  three
commonly used circuits incorporating this feature are discusr attention
is devoted to the use of magnetic amsed
   /
7822
magnetic amplifiers and weak currents  particular amplifiers for measurement
purposes
   /
7823
investigations of noise in audio frequency amplifiers using junction
transistors  noise factor measurements were made using various types
of transistor in different circuit arrangements the influence of
input termination and operating point are discussed  results are
presented graphically  three distinct sources are identified shot
noise and thermal noise are independent of frequency over the af
band semiconductor noise varies approximately as  noise properties
of transistors and thermionic valves are compared
   /
7824
search for a general definition of energy and of the parameters of
extension and intensity  a scheme of relations between energy and
extension and intensity is presented which leads to definitions generally
valid for all forms of energy including those as yet unknown
   /
7825
conductivity and viscosity effects on wave propagation in piezoelectric
crystals
   /
7826
diffraction of pulses by a circular cylinder
   /
7827
economic aspects of printed foil circuits
   /
7828
electroluminescence with nonsinusoidal fields  experiments using
pulses of rectangular sawtooth exponential form were made to supplement
the information obtained by applying sinusoidal voltages of piper
and williams  the phosphor investigated was giving green and blue
luminescent bands which were examined separately  measurements were
made of field and frequency dependence and decay law with square
pulses only qualitative observations were made with the other waveforms
a theoretical interpretation of the results is advanced
   /
7829
voltage dependence of electroluminescent brightness  an equation
of the form relating the brightness l to the voltage v is found to
fit experimental data well a b and v being constants
   /
7830
the two dimensional electric field of a curved sided wall or groove
on an infinite plane  results of a theoretical investigation are
tabulated and presented graphically  the calculation involves conformal
transformations and elliptic integrals for complex moduli values
of the latter are tabulated
   /
7831
some properties of dielectrics with high permittivity  analysis shows
that for a conductor surrounded by a dielectric of sufficiently high
permittivity the depth of penetration of hf current is dependent
only on the constants of the dielectric  formulae are derived for
solid and for hollow dielectric cylinders and spheres subjected to
an alternating electric field expressing the conditions under which
the amplitude of oscillation of the bound electrons becomes infinite
the results can be stated in terms of characteristic radii for a
given material and frequency
   /
7832
theory of electrical conduction  general theory of conduction in
pure metals is developed without assuming spherical symmetry for
the energy levels  this is applied to calculate the conductivity
of the alkali metals
   /
7833
the theory of electrical resistance of good metallic conductors
reasonable values are obtained for the resistivity of the alkali
metals except li by calculation based on the propagation of compression
waves in an ionic continuum
   /
7834
electromagnetic heating of thin layers of conductors or semiconductors
generalizations relating to the problem of the determination of the
ideal thickness  formulae are quoted for the thickness of a cylindrical
and of a spherical metal shell to make optimum use of the heating
effect of a hf magnetic field  if the metal is replaced by a material
which is both a conductor and a dielectric the corresponding expressions
are quite different though the ratio between them is the sam  consideration
is also given to the case of a cylindrical shell rotated rapidly
in a uniform constant transverse magnetic field
   /
7835
artificial increase of electrical breakdown strength of air at low
pressure in the region of mcs  measurements covering the pressure
range mm hg using gap widths of mm and frequencies of and are reported
under these conditions the superposition of a moderate direct voltage
on the alternating voltage can increase the uhf breakdown stress
quite considerably  typical results obtained with direct voltages
up to are shown graphically the effect is large enough to find practical
application as an inhibitor of breakdown in electronic equipment
for operation at high altitudes
   /
7836
theory of electric breakdown in the high temperature region and its
relation to thermionic emission  discussion is based on consideration
of the distribution of electrons over the energy states rather than
the behaviour of individual electrons
   /
7837
energy distribution of secondary electrons from magnesium and berylium
alloys  experiments were carried out at a pressure of mm hg with
alloys and activated by heating either in a vacuum or in an atmosphere
of oxygen  curves showing the dependence of the secondary emission
coefficient on the energy of primary electrons and of the secondary
current on the voltage at the collector are plotted  the mechanism
of secondary emission from complex surfaces is not considered to
be similar to that of the malter effect the role of the accelerating
field is probably reduced here to the compensation of local retarding
fields above the inhomogeneous surface of the activated layer
   /
7838
the secondary electron emission of sodium and zinc  experiments are
described in which the metal to be examined was deposited on a copper
target block in a valve with a guiding grid accurately aligned with
a collector grid  the collector potential was high enough for saturation
secondary current  to introduce the sodium an electrolytic method
was used  for sodium the maximum secondary emission factor reached
a peak value of during the coating process and then fell to a constant
value of ccurring at a target potential of  for zinc the maximum
value of occurred at a target potential of
   /
7839
non maxwellian theory of homogeneous anisotropic plasmas  using theory
based on boltzmanns integegro differential equation a calculation
is made of the distribution of electron velocities in an ionized
gas subjected to a constant magnetic field for non maxwellian conditions
explicit expressions are derived for the magneto ionic conductivity
dielectric tensor hall effect deflection of an electron beam and
a generalized form of langevins mobility formula  results are compared
with those obtained by other methods based on mean free path  wave
propagation is studied formulae being derived for refractive index
birefringence phase and group velocities attenuation polarization
and critical frequencies  classical results of ionosphere theory
are confirmed  see also of
   /
7840
magnetic fields in plasmas with turbulent motion  when a plasma comprising
electrons and ions is in turbulent motion diffusion currents
give rise to magnetic fields  these can be demonstrated by rotating
the gases produced by burning a mixture of oxygen and propane  an
account is given of suitable experimental technique
   /
7841
spin precession in a vibrating bloch wall at small amplitudes  the
natural frequency of vibration of the wall is derived on the basis
of an effective internal magnetic field  the formula obtained for
a wall is identical except for a factor with that given by doring
for a wall on the basis of the wall mass
   /
7842
electromagnetism old and new  comment on and of and authors reply
   /
7843
energy of the harmonic oscillator in vacuum  continuation of work
abstracted previously of braffort et al  the term energy of the oscillator
us used to indicate the additional energy acquired by a free
charge on passing into the oscillating state  the energy of the harmonic
oscillator in the fluctuating field of the absorber is equal to the
product of its natural frequency and a universal constant
   /
7844
electronic band structure of solids  brief report of conference held
at the radar research establishment at malvern in september at which
criticisms of the energy band theory were advanced
   /
7845
the isotropic component of cosmic radio frequency radiation  possible
sources of the isotropic component deduced by westerhout and oort
of february are discussed  the integrated radition from normal extragalactic
nebulae is shown to be inadequate to account for the observations
which may be explained on the basis of collisions between galaxies
the intensity to be expected depends strongly on the cosmological
theory assumed hence accurate measurements of the extragalactic component
may yield information of value for distinguishing between different
theories
   /
7846
prediction of the present sunspot cycle  the reliability of the prediction
method presented previously is examined with reference to observed
sunspot data for the period
   /
7847
observation of the total eclipse of the sun on june at hagaby sweden
and of the partial eclipse using the radio telescope at meudon observatory
the curve obtained from the observations in sweden at was less
irregular than that observed at khartoum in this is consistent with
the lower level of solar activity  at totality the residual radiation
was compared with in
   /
7848
symposium on scientific aspects of the international geophysical
year  the text is given of a number of papers including the following
morphology of ionospheric storms pp  the morphology of the aurora
pp  diurnal and seasonal variation of the airglow  transport problems
in the atmosphere  evidence for winds in the outer atmosphere  solar
activity and terrestrial disturbances  geographic basis for antarctic
scientific observations
   /
7849
homogeneous dynamos and terrestrial magnetism  solutions of maxwells
equations are obtained for a sphere of electrically conducting fluid
in which there are specified velocities  solutions exist when harmonics
up to degree four are included but for a greater number of harmonics
the convergence of solutions has not been proved  orders of magnitude
are derived for a number of quantities connected with the dynamo
theory of terrestrial magnetism
   /
7850
possible cause of disturbance of solar diurnal variation of geomagnetic
field  a mechanism is considered whereby currents in the ionosphere
acquire a pattern such as to produce the observed s variations of
the geomagnetic field
   /
7851
infrared radiation of night sky  production of infrared radiation
in the upper atmosphere is discussed and the estimates given by various
authors for the heights at which radiation is produced are quoted
the heights coincide roughly with the d and e layers  references
including about to russian literature
   /
7852
seasonal variation in the absorption of solar radiation by atmospheric
ozone at microns
   /
7853
aircraft investigation of the large ion content and conductivity
of the atmosphere and their relation to meteorological factors  continuation
of work described previously of callahan et al  simultaneous
measurements of conductivity large ion concentration temperature
and humidity over the altitude range are reported  the results indicate
that over continental areas in fair weather there exists z layer
adjacent to the ground varying in height from to in which the vertical
distributions of large ions and conductivity are controlled primarily
at atmospheric turbulence  at the upperaboundary of this layer there
is a transition region about ft high in which the conductivity increases
by a factor of while the large ion content decreases by a factor
of  above this region the large ion content is reduced to a very
low value and the conductivity is determined primarily by the intensity
of cosmic radiation and
   /
7854
reviews of modern meteorology  the physical state of the upeer atmosphere
the composition of the atmosphere at various levels is discussed
mainly as regards the constituents n and o this provides an indication
of the value to be assigned to the mean molecular weight in the formula
for converting scale height to temperature  following the discussion
of the properties of the static atmosphere the evidence for movement
in the high atmosphere is reviewed and the complications to be expected
in the upper levels of the ionosphere as a results of the interaction
of the ionized gas with the earths magnetic field are considered
   /
7855
determination of electron densities in the ionosphere from experimental
curves  an error in the argument used in the original paper of was
pointed out by kelso of it is suggested that it may nevertheless
be possible to provide a rigorous argument justifying the use of
the curves given
   /
7856
concentration of hydroxyl in the upper atmosphere  a brief critical
discussion of possible reactions and their equilibria at heights
of about
   /
7857
the physics of the ionosphere  a brief survey of selected aspects
of recent research on the ionosphere
   /
7858
the anomalous equatorial belt in the f layer  an examination has
been made of the relation between the maximum electron density and
geomagnetic latitude for y hours of the equinox day other than noon
the abnormally low values of n found over a wide equatorial belt
at noon tnd to disappear during the afternoon and to be replaced
by abnormally high values during the evening the n anomaly disappears
between midnight and  these variations appear to be due to contraction
of the vertical extent of the f layer during the first half of the
night and an expansion prior to noon
   /
7859
f layer regularities at ibadan  analysis of records for the period
december january confirms that the daily variation of n the total
electron content in a column of unit cross section below the height
of maximum ionization in the f layer is relatively free from anomalies
exhibited by the corresponding variation of n the maximum electron
density of the f layer  in calculating n the non parabolic electron
distribution at ibadan must be taken into account  inclusion of the
f layer electron contribution has no appreciable effect on the regularity
of the daily variation  a new method is described for deducing
the recombination coefficient and the rate of ion production from
the variation of n  the phenomenon of sunset minimum of is discussed
reasons are given for considering it a spurious effect arising from
errors in the reduction of records
   /
7860
preliminary results of ionospheric observations of the sola eclipse
of june  ionosphere soundings were made in the o zone of totality
from a ship off the coast of southern norway  a panoramic instrument
was used covering the frequency range in a second instrument was
used for absorption measurements at and  the variation of the maximum
electron concentrations for the different layers is shown graphically
the recombination coefficients are estimated from the delay between
the optically and the ionospherically observed maximum phase and
by trying different values in the equilibrium equation expressings
the dependence of electron concentration on unobscured fraction of
the solar disk  the recombination coefficient for a normal law is
greater than or equal to for the e and f layers and over for the
f layer
   /
7861
the physics of the ionosphere  report of conference held at cambridge
england in september at which papers were presented and discussed
summarizing existing knowledge of the subject
   /
7862
simultaneous ionospheric absorption measurements at widely separated
stations
   /
7863
ionospheric thermal radiation at radio frequencies part further observations
continuation of work reported previously pawsey et al  observations
were made at frequencies near over a period of about a year at
a site chosen to minimize man made noise  the location of the absorbing
regions was deduced from consideration of pulse echo observations
of the d region made on of gardner and pawsey  the ionosphere temperatures
deduced ranged from about to varying appreciably from day to
day and being lower and less variable in winter  an increase of up
to during sudden ionospheric distinct disturbances is probably do due
to a change of height of the absorbing region  polarization measurements
in september indicated that the absorbing regions were then located
at a level where the temperature decreased with height
   /
7864
effects of solar flares on the absorption of cosmic noise  abnormal
variations of ionospheric absorption were investigated during the
course of the observations reported previously of  most cases of
unusually high absorption appear to be associated with solar flares
observations of the increases in absorption during the resulting
sudden ionospheric disturbances are compared with observations of
sudden phase anomalies in waves rn waves reflected from the ionosphere
a db absorption difference appears to correspond to a phase anomaly
of about at the frequency considered  as a method of detecting sudden
ionospheric disturbances observation of the absorption variation
variation is as sensitive as and more convenient than observation
of phase anomalies  evidence was found of a delayed increase of absorption
about hours after some solar flares the magnetic records sshowed
no abnormal features at these times and it is uncertain whether the
excess absorption occurs within the ionosphere or outside it
   /
7865
theoretical considerations regarding the day glow  results of rocket
observations made by miley et al  are examined the reported great
altitude and luminosity of the emissive source cannot be reconciled
with the assumption that dayglow is due to direct photo action by
incident solar radiation  a determination is made of the emission
to be expected from processes known to be operative including resonant
and fluorescent scattering photo dissociation photo ionization and
recombination
   /
7866
chain process of accumulating charges in thunderclouds  theoretical
considerations lead to the conclusion that the build up of charge
in a thundercloud follows an exponential law
   /
7867
field intensities and charge densities in thunderclouds  calculations
based on the assumption that the thundercloud is ellipsoidal give
the maximum field strength in the cloud as and the charge density
as cm  the conditions under which lightning discharges may be initiated
are discussed
   /
7868
radar echoes from lightning
   /
7869
the wave forms of the electric field in atmospherics recorded simultaneously
by two distant stations  electric field variations were recorded
at two stations one near uppsala the other at fotevik at the south
western tip of sweden during september and the variations were correlated
with thunderstorms which occurred at distances between and from
uppsala  in pre discharge atmospherics a quasi periodic variation
was observed which corresponded most frequently to a wavelength of
km  the waveforms of the main discharges varied greatly with distance
often in q a quasi periodic manner  a unipolar form was also observed
the mean waveform obtained from several hundreds of oscillograms
shows five pulses reflected from the ionosphere in addition to the
ground pulse  waveform changes with distance travelled can only be
calculated by making large simplifications  numerous oscillograms
are reproduced and discussed
   /
7870
the processing and some characteristics of coaxial cylinder corona
stabilizer tubes  the running voltage of tubes filled with hydrogen
has been found to be stable to within over and to within over h
the dependence of slope resistance on pressure and current has been
investigated  the temperature coefficient of running voltage is about
per deg c  it may be possible to obtain higher current by glow discharge
treatment
   /
7871
a new type of high voltage machine  a machine is described which
operates on a principle related to that of the van de graaff generator
with the difference that the moving belts carry not surface charges
but capacitors which become charged on reaching a certain point and
are then connected in series  performance figures are given for an
experimental model in which the capacitors are stationary and the
electrical contacts are rotated
   /
7872
wide band analog function multiplier  operation of the multiplier
is based on the formula the squaring is effc uaring is effected by
means of beam deflection tubes with parabolic characteristics of
soltes
   /
7873
analogue computer with stepping switch drive for the solution of
algebraic equations of up to sixth degree  the analogy used is that
between a sinusoidal voltage and a complex quantity  the representation
of the polynomials is effected using feedback amplifiers as computing
elements  the zero points corresponding to the solutions are found
automatically
   /
7874
some devices permitting study of the variable regime in the transportation
of gas in pipes  a particular application is discussed of the
analogue computer arrangements described previously of
   /
7875
programming a digital computer for cell counting programming a digital
computer for cell counting and sizing
   /
7876
magnetic materials for digital computer components part a theory
of flux reversal in polycrystalline ferromagnetics
   /
7877
logical and control functions performed with magnetic cores  use
of magnetic cores with square hysteresis loops in digital computer
systems based on the single line shift register is described
   /
7878
a technique for nonlinear function generation  a method is described
for converting a circuit whose output is proportional to the nth
root of the input to give the nth power or vice versa  a practical
circuit based on a variable gain feedback amplifier for dealing with
square and square roots is illustrated
   /
7879
two new electronic analog multipliers  improved types of four quadrant
multipliers for deriving the product of two time functions are described
one uses a double amplitude modulation scheme applying the work
of sternberg and kaufman on the two frequency modulation product
problem of  the other uses successive phase modulation and amplitude
modulation of a carrier  the accuracy obtainable is discussed
   /
7880
automatic digital computation  contains discussions and original
papers presented at the symposium held at the national physical laboratory
in march
   /
7881
calculation of losses in transformer cores  expressions for core
losses are developed which take account of the nonuniformity in the
flux distribution across the face of the core plates  the nonuniformity
across the stack of plates is neglected
   /
7882
the noise generated in a coil with a ferro magnetic core  the discussion
presented indicates that when there is no varying or alternating
magnetization of the core the noise can be calculated from the nyquist
formula provided that the resistance of the coil is measured using
an alternating voltage of such magnitude that the magnetization process
remains linear
   /
7883
composite cores for instrument transductors  the characteristics
of self excited transducers are markedly dependent on the properties
of the core material  cores with satisfactory properties can be produced
at reasonable cost by combining different materials  experimental
results are reported for a core comprising a mumetal bridge and a
u shaped grain oriented si fe yoke
   /
7884
auto self excited transductors and push pull circuit theory  the
modes of operation of transductors with parallel bridge and centre
tap connections are explained  expressions are derived for the sensitivity
and time constant under idealized conditions  an examination
is made of the use of transductors in push pull pairs to obtain magnetic
amplifiers with outputs whose polarity depends on the signal sense
the transductors are assumed to e be of the auto self excited type
with resistance loads
   /
7885
component design trends special purpose relays gain new uses
   /
7886
time delay in high speed ferrite microwave switches  measurements
indicate that for an x band switch using a rod of a particular mg
mn ferrite and actuated by a current pulse of given magnitude and
rise time the time delay of the switch is about
   /
7887
study of the dielectric in paper capacitors  measurements were made
of the loss angle of wet and dry paper at and of the permittivity
of the impregnant and of the impregnated paper  from these an equivalent
circuit was derived for the capacitor which can be used in estimating
the quality of the paper and desirable conditions of manufacture
breakdown strength measurements were also made to determine the optimum
applied voltage
   /
7888
arc arc inductance and dynatron capacitance  the stability of systems
with nonlinear negative resistances of arc and dynatron types is
discussed  analysis indicates that though the arc can have e some
inductive po properties and the dynatron capacitive ones these are
not essential to an explanation of the behaviour of the systems
transient conditions and steady oscillation states are considered
   /
7889
further bounds existing on the transient responses of various types
of networks  five theorems further to those presented previously
are proved and illustrated
   /
7890
an approximate treatment of cascaded four terminal networks  an approximate
expressions is derived for the nth power of a matrix  the result
is used in an approximate treatment of a ladder network used as a
filter
   /
7891
the approximation problem of network synthesis  a review with references
   /
7892
series resonant circuit theory  expressions are derived for the fractional
errors in tuning capacitance resonance frequency maximum current
and selectivity at current resonance due in the case of frequency
tuning to the frequency dependence of the circuit resistance and
in the case of capacitance tuning to capacitor losses and coil self
capacitance
   /
7893
the mesh counterpart of shekels theorem  it is shown that whereas
the determinant of the admittance matrix of a network is independent
of the choice of reference node of shekel the corresponding statement
for the mesh determinant is not true
   /
7894
distortion of arbitrary waveforms by resonance sections  the method
developed earlier for rc sections is extended to sections including
an inductance
   /
7895
extension of nonreciprocal ferrite devices to the frequency range
calculations indicate that devices such as circulators of reasonable
dimensions can be designed for operation at frequencies below by
using static magnetic fields of intensity greater than required for
ferromagnetic resonance
   /
7896
a short slot hybrid for mm  the x band junction by riblet of was
redesigned for a wavelength of mm  a brief illustrated note n on
this junction is given
   /
7897
resonance conditions in a sytem of two circuits with inductive coupling
assuming m r l and c constant conditions are derived for the existence
of one minimum and two maximum values of current in the secondary
in the general and in two particular cases  the results are applied
to a band pass filter and presented graphically for two different
parameter valuex  low q values are assumed
   /
7898
microwave filters  theory of filters comprising coaxial lines and
or waveguides is developed by reference to equivalent lumped constant
circuits  band pass and band stop filters of ladder amplifier and
bridge types are discussed
   /
7899
tunable microwave aerial diplexer  a diplexer for the band is based
on the use of continuously tunable resonant circuits comprising coaxial
line sections short circuited at one end and having a third coaxial
conductor insulated from and sliding within the inner conductor
in a particular design illustrated for separation between transmission
and reception frequencies the transmitted energy penetrating into
the receiver is attenuated by
   /
7900
theoretical investigation of three stage tchebycheff type band pass
filters
   /
7901
juding the quality of oscillator circuits  discussion of the frequency
and amplitude stability of oscillators considered as composed of
a slightly nonlinear frequency independent amplifier and a linear
frequency dependent feedbz feedback quadripole  stability is found
to depend on the rate of change of the imaginary part of the voltage
transfe transfer characteristic of the feedback quadripole  the use
of this criterion in the design of bridge stabilized rc oscillators
is illustrated  measurements on and various faults of experimental
oscillators are briefly discussed
   /
7902
generation and use of single frequency pulses in electroacoustics
and musical acoustics
   /
7903
experimental investigations on multivibrators and amplifier circuits
with secondary electron emission valves as described by kroebel
multivibrators of the type described by kroebel of february were
investigated  pulse flank slopes of the order of up to pulse amplitudes
of were obtained  the multivibrator can be modified to act as a pulse
amplifier without feedback
   /
7904
equipment for excitation of spectra by high frequency pulses  the
equipment comprises a pulse generator which controls a clapp oscillator
of followed by a frequency multiplier and amplifiers  average hf
power transferred to the discharge tube is about with peak power
of the frequency is about mcs  argon spectra obtained are shown
   /
7905
transistor frequency standard  this unit designed primarily for geophysical
prospecting has a printed circuit base and uses transistors
in all stages  accuracy is within part in over the range f to f
an oscillator is followed by a pulse forming amplifier and first
divider stage then by two dividers in parallel whose outputs are
mixed to obtain an u output frequency of cs
   /
7906
the transient response of direct current amplifier systems  dc amplifiers
of the dc ac conversion type have an upper frequency response
limited by the detector circuit and when negative feedback is used
transients are amplified considerably more than the steady signal
the form of the transient response and methods of reducing its magnitude
ar discussed
   /
7907
a long lived packaged amplifier for aircraft  the development and
construction of units with a probable life of hours are described
selected valves are pressed into cast al wells lined with a silicone
rubber paste which is hardened by a short curing process this is
more effective for heat transfer than al dust or foil  deposited
carbon resistors and capacitors serviceable at are mounted on a phenolic
board supported by the al base and wired to a recessed plug  the assembled
unit after testing is embedded in liquid plastic which is then
solidified  test figures for heat dissipation under different conditions
are given
   /
7908
amplifier stages with transitionally coupled two stage band pass
filters particularly for large bandwidths  the amplitude and group
delay characteristics of an amplifier stage consisting of two coupled
circuits are analysed for the case when the amplification is constant
over a wide frequency band transitional coupling  the case when the
damping factors d and d of the two circuits are equal is considered
first and formulae are also given for the cases of either d or d
tending to zero  formulae are also given for transforming a filter
with indirect inductive coupling into one with direct inductive coupling
design curves are shown
   /
7909
nyquists criterion for multiple loop feedback circuits  a method
of deriving the stability criterion alternative to that of cutteridge
of and based on conformal transformation is presented  see also of
january
   /
7910
the effect of inverse feedback on input impedance  formulae are given
for the input impedance gain and gain without feedback of twelve
single stage amplifiers and these together with the circuits and
their equivalents are tabulated
   /
7911
alteration of dynamic response of magnetic amplifiers  analysis is
presented indicating how a magnetic amplifier of full wave self saturating
type can be made to exhibit phase lead or lag by adjusting the
parameters of the feedback networks
   /
7912
analysis of the common base transistor circuit  simple equations
are obtained by choosing a hybrid inverted network as the equivalent
circuit for investigating the operation of the grounded base point
contact transistor amplifier
   /
7913
dc stability of transistor circuits  the design of amplifiers using
junction transistors is discussed with particular reference to the
influence of the base to collector leakage current which increases
rapidly with rising temperature  for stable operation the change
of collector current produced by a change of leakage current should
be low circuit arrangements for achieving this are indicated
   /
7914
the distortion of fm signals in passive networks  expressions for
the fundamental and first four harmonics of the output instantaneous
frequency are given in a series expansion in terms of modulation
frequency and modulation index the coefficients in the expansion
depending on the network parameters  effects of detuning are considered
and detailed results for the butterworth circuit are presented
   /
7915
the linear distortion of fm signals in band pass filters for large
modulation frequencies  the linear distortion of a fm signal in a
highly selective band pass filter follows almost exactly the static
response curve of the network provided the following conditions are
fulfilled the modulation frequency is not less than two thirds of
the semi bandwidth the modulation index does not exceed unity the
network q is sufficiently large
   /
7916
a ferrite frequency modulator  the modulator described comprises
a ferroxcube ring carrying a rf winding and located in the gap of
a ni fe core carrying lf and polarizing windings  it is suitable
for operation over the frequency range from to uhf with slight modifications
its demodulated distortion is at an oscillator frequency of
and a frequency deviation and at and respectively
   /
7917
discriminator circuit analysis  theory and performance figures are
given for a simple frequency discriminator circuit using an asymmetrical
arrangement  the conversion efficiency compares favourably with that
of the equivalent foster seeley discriminator  it is particularly
recommended for purposes where high efficiency is of greater importance
than accurate linearity over a wide frequency range
   /
7918
a universal printed circuit  the universal printed circuit board
has a standard pattern of parallel wires on one side and is useful
at the design stage when prototypes are required for testing since
circuit changes may be made with relative ease
   /
7919
amplitude frequency characteristics of ladder networks  suitable
mainly as a reference work for telecommunication engineers
   /
7920
proposals for units for area electric displacement and magnetic field
strength
   /
7921
the two dimensional magnetic or electric field of a single isolated
pole piece  theoretical investigation for a pole piece consisting
of a thick plate terminated by a concave semicircular cylinder  conformal
transformations and elliptic functions are used  the variation
of the field strength along the edge of the pole piece and along
the external axis of symmetry is calculated and shown graphically
   /
7922
observation of the costa ribeiro effect on the dissolution of naphthalene
crystals  report of experiments indicating that electric charges
are developed on dissolving single crystals of naphthalene in a solvent
of very low conductivity such as toluene the crystals thus treated
constitute natural electrets
   /
7923
electro fusion a new phenomenon observed in the phase changes of
dielectrics under the influence of an electric field  experiments
are described which indicate that application of a field between
the electrodes of a capacitor with the dielectric partly in the solid
and partly in the liquid state accelerates the phase change in the
dielectric  from measurements of the current and calculation of the
joule energy dissipated it is shown that this energy is several hundred
times smaller than the heat necessary for the normal fusion of the
corresponding mass of the dielectric
   /
7924
field induced melting of dielectrics  theory is presented relevant
to the phenomena described by costa ribeiro above
   /
7925
plasma oscillations in a periodic potential the one zone theory
the plasma oscillation theory of collective electron interactions
developed by bohm and pines of and back references can be applied
to the problem of the cn conduction electrons in metals by modifying
it to take account of the periodic potential present  this modification
is carried out neglecting the interactions of electrons in different
zones and assuming that the effect of inter zone transitions on the
collective behaviour is small enough to be treated by perturbation
theory  the main effect of the potential is to alter the effective
mass of the electrons
   /
7926
the electrical and thermal conductivities of monovalent metals  numerical
calculations for the case of so sodium using the bardeen formula
for the scattering cross section and blackmans value for a longitudinal
b debye temperature agree better with observation than do the simple
bloch expressions but there still remain discrepancies  further x
study of the scattering cross section function might remove these
   /
7927
high frequency resistance of tin and indium in the normal and superconducting
state  further measurements at confirm results obtained previously
of grebenkemper and hagen
   /
7928
the physical nature of a metal surface in conduction theory  a discussion
is presented in which the reflection of electrons striking the
surface from inside is treated as a diffraction phenomenon
   /
7929
gaseous electronics conference in new york  papers presented at the
conference held in october are surveyed briefly  physics of plasma
and ionization processes leading to electrical breakdown were among
the subjects discussed
   /
7930
study of gaseous discharges by magnetic resonance  measurements are
reported which indicate that the technique of magnetic resonance
may prove useful for studying the characteristics of low pressure
gas discharges
   /
7931
relaxation oscillations and noise from low current arc discharges
noise measurements were made on arcs using various electrode materials
and gases over the frequency range  the results for al electrodes
in air are plotted in comparison with the computed spectrum  pulses
generated in the circuit formed by the series limiting resistor and
the capacitance across the discharge are considered responsible for
most of the noise
   /
7932
formative time of the cathodic space charge  a criterion for evaluating
the formative time is based on observations of rise time and overshoot
in intermittent discharges  different kinds of intermittent discharges
are reviewed
   /
7933
on intermittent discharges in air at low pressure  an experimental
investigation is reported of the dependence of the discharge frequency
on the gas pressure and electrode separation
   /
7934
forces between parallel electron streams  a simplified fundamental
analysis is presented taking account of the forces of acceleration
es repulsion em attraction gravitation and any local fields  the
results indicate that for all electron velocities up to the immediate
threshold of the velocity of light the resultant force between parallel
electron streams is repulsive
   /
7935
spectroscopic studies of highly ionized argon produced by shock waves
   /
7936
kinetic theory of weakly ionized homogeneous plasmas part  a rigorous
method is presented for integrating boltzmanns equation by successive
approximations for a weakly ionized gas subjected to an alternating
electric field and a static magnetic field  the electron velocity
distribution function is developed with respect to the electric field
and the individual functions obtained are developed as spherical
functions  the method is applied to investigation of a lorentz type
gas
   /
7937
electrical conductivity of highly ionized argon produced by shock
waves
   /
7938
antiferromagnetism and ferrimagnetism of non stoichmetric compounds
a simple quantitative treatment is given of the magnetic properties
of a substance containing vacancies enabling the most important magnetic
properties of many non stoichiometric compounds to be interpreted
   /
7939
representation of electromagnetic fields of any frequency using the
energy quantum model  development of theory presented previously
of  wave propagation phenomena including reflection interference
and diffraction are explained in terms of the energy quantum model
static fields are also considered  voltage current and characteristic
impedance are related to mechanical quantities and an appropriate
system of dimensions and units is presented
   /
7940
cerenkov radiation from extended electron beams  calculations are
made of the radiation emitted by bunched beams passing close to dielectric
surfaces both plane and cylindrical geometries are considered
   /
7941
calculated diffraction patterns of dielectric rods at centimetric
wavelengths  calculations of the field behind the cylinder are made
for the case of a normally incident wave with the electric vector
parallel and perpendicular to the cylinder axis  the dielectric materials
considered include polystyrene lucite and tenite  the diffraction
pattern is only slightly dependent on the dielectric constant of
the rod  small discrepancies between the calculated values and values
obtained experimentally of are probably due to resistive loss in
the dielectric
   /
7942
spectral investigations in the wavelength range around mm  a description
is given of the construction an method of operation of an infrared
type spectrometer which has been used with thermal radiator and receiver
to obtain absorption spectra at wavelengths over mm  the spectrum
obtained for water vapour over the range mm is shown as an example
results obtained with hcn and are also reported
   /
7943
variable frequency microwave cavity spectro meter  molecular gas
spectra at wavelengths around are investigated using a system in
which a single coaxial cai cavity serves as stark or zeeman modulation
cell and as frequency reference unit
   /
7944
simplified impurity calculation  the methods developed previously
of march are used to investigate the case of a local perturbation
in a simple cubic lattice
   /
7945
abnormal galaxies as radio sources  results of radio telescope observations
at sydney indicate that galaxy ngc is probably a radio source
whereas ngc is probably not
   /
7946
observations of galactic radiation on a wave length of cm  report
of measurements made using the wurzburg mirror at marcoussis  results
are presented in the form of an isophot map of the galaxy with intensities
expressed as apparent temperature in arbitrary units  the cm
radiation is attributed principally to ionized hydrogen  a table
giving the positions of localized sources includes five thought to
have been observed for the first time
   /
7947
study of solar rf radiation on around sunset and sunrise  report
of measurements made at paris using a parabolic mirror of diameter
m  graphs are presented showing the variation of refraction with
solar angle and quasi periodic intensity variations observed when
the angle of elevation is less than  attenuation due to absorption
by oxygen is observed at zn angles less than about
   /
7948
fine structure of solar radio transients  brief report of observations
made during  solar bursts observed at and were found to be composed
of numerous discrete pips with median duration approximately proportional
to wavelength  the spectral width of a pip is a few per cent of
its mean frequency of occurrence of the pips was greatest at
   /
7949
aerial smoothing in radio astronomy  theoretical considerations show
that the aerial does not register those spatial fourier components
of the true distribution of radio brightness having frequencies beyond
a cut off determined by the aerial p aperture  components of lower
frequency are registered but their relative strengths are altered
the consequences are that there are invisible distributions which
produce no response when scanned by the aerial and in conducting
a survey the measuring points must be closer together than half the
period of the fourier component at cut off
   /
7950
prominence activity  charts prepared from observations made at m
kodaikanal show the salient features of solar prominence activity
during the last four sunspot cycles  a preliminary examination suggests
that during the maximum phase of the cycle geomagnetic activity shows
a better correlation with prominences than with sunspots
   /
7951
the emission of radiation from model hydrogen chromospheres part
an improved method is presented for calculating the characteristics
of the radiation field of and the lyman continuum emitted by model
hydrogen atmospheres at kinetic temperratures of k  a useful application
of the results would be in interpreting observations of prominences
and flares
   /
7952
qualitative explanation of the commencement of some polar magnetic
disturbances based on the theory of chapman and ferraro
   /
7953
geomagnetic and geoelectric variations  analysis of records of geomagnetic
pulsations especially those with periods of sec indicates that
they may be associated with ionospheric vibrations caused by a disturbance
of the ionization equilibrium  information regarding the distribution
of ground conductivity is obtained from the relation between the
magnetic pulsations and the associated transverse electric field
pulsations
   /
7954
the abnormal variations of the horizontal magnetic intensity t at
huancayo peru  the magnetic field of the ionospheric current system
arising from lunar atmospheric tidal motion is calculated for various
points on the earths surface  the daily variation of the horizontal
component at huancayo is found to be nearly twice as great as at
batavia though the latitudes of the two points are nearly the same
observations at a point between the geographic and magnetic equators
in the northern hemisphere should help to explain this anomaly
   /
7955
on the world wide disturbance in f region  the average disturbance
in the value of f during magnetic storms is separated into the short
time part and the local time part d  these were calculated in the
cases of typical storms from data obtained from stations in the northern
hemisphere  both their range and phase are correlated with the magnetic
activity  the phase of d during the active stage of the magnetic
storm is almost entirely dependent on the local time but after the
cessation of activity the disturbance moves with the rotating earth
see also
   /
7956
an analysis on the diurnal variation of the terrestrial magnetism
especially on the day time variation of geomagnetically quiet days
   /
7957
vertical distribution of atmospheric ozone at longyearbyen spitzbergen
   /
7958
the constitution of the upper atmosphere and the ionosphere research
station of the institute of geophysics at genoa  an outline of knowledge
on the structure and electrical properties of the ionosphere is followed
by a description of ionosphere sounding equipment recently put into
operation and comprising pulse transmitter for the range double superheterodyne
receiver and cro recorder
   /
7959
calculation of the collision frequency in the ionosphere  it is shown
that if is the true reflection height corresponding to the lowest
frequency of the sounding sweep and is the true reflection height
corresponding to the first critical frequency greater than then provided
that the distribution of ion concentration and collision frequency
are known for values of up to and the absorption is observed over
the range the function expressing the height distribution of collision
frequency can be determined over the range by solving a an integral
equation due to abel
   /
7960
turbulence in the upper ionosphere  from the experimental data at
present available it is shown that the reynolds number in the upper
f region level is of the order of  the region may therefore be turbulent
it is suggested that the high level diffracting screens which
give rise to spread f r echoes and to radio star fading are caused
by non laminar flow and that their non appearance during the daylight
hours may be due to the inhibition of turbulence by large temperature
gradients by lower drift velocities or by an increase in the kinematic
viscosity
   /
7961
motion of clouds of abnormal ionization in the auroral and polar
regions  a study has been made of unusual types of echo exhibited
by film records of rapid succession sweep observations at several
stations in northern canada  three distinct types of echo are identified
probably corresponding to horizontally moving e clouds clouds descending
vertically from the f to the e layer and clouds moving at extremely
high velocities in the e layer  type echoes were observed only at
stations very close t the auroral zone maximum and may be due to
sweeping of the auroral ionizing agent  type echoes also appear to
be related to an auroral ionizing agent
   /
7962
information obtained from ionization charts  ionization charts drawn
up monthly for two zones covering america and europe africa and asia
are discussed  the distributions observed generally confirm the theory
of geomagnetic control of the f layer of appleton but some exceptions
are observed there appears to be a lower limiting value for the height
of the sun below which the geomagnetic control does not operate
the control is effective at latitudes as high as  measurements at
other times besides midday are required to study the effect  asymmetry
as between northern and southern hemispheres is observed  the north
polar zone was studied in detail the auroral e zone appears to be
centred on the geographic pole
   /
7963
velocity of movement of sporadic e clouds  curves of the diurnal
variation of the e layer critical frequency for o four japanese stations
indicate a progressive retardation of the time of occurrence of the
maximum on passing from the highest latitude to the lower latitude
stations  a value of about is deduced for the horizontal component
of the velocity of the e clouds this is of the same order as the
velocity of e layer winds found by various methods
   /
7964
interpretation of measurements on the ionosphere f layer  the maximum
ionization level of the f layer is often located within the lower
part of the f layer so that echo sounding yields a continuous curve
for the f and f layers with a more or less marked maximum or merely
a point of inflection indicating the virtual height of the f layer
is not clearly defined  a correction is required the sign of which
depends on th the theory accepted for the origin of the f layer
mohlers theory of gives results in good agreement with observations
   /
7965
lunar tides in the ionosphere f layer at dakar  hourly records of
and for the years have been analysed maximum variations and times
of occurrence of maxima are tabulated for the different seasons
the semi diurnal component is predominant except in summer during
winter the tidal variations of and have amplitudes of and respectively
the phases and amplitudes are considerably different from those observed
at other tropical stations anomalies may be due to the circumstance
that the f layer at dakar is very thick in summer the ionization
maximum occurs at the equinoxes and not in winter
   /
7966
on the meridional distribution of the minimum virtual height of the
f layer  results of an analysis of daily variations in from observatories
indicate the presence of two periodic terms the diurnal variation
which is dependent on the geographic latitude and the semidiurnal
variation which depends on the geomagnetic latitude  the former may
be considered as the thermal effect the latter as the tidal effect
in the f region
   /
7967
the effect of the solar tides and the temperature change on the daily
variation in electron density and height of the f layer  the departure
of the maximum electron density from the norm of a static chapman
region is inversely proportional to the temperature variation except
in the morning when the electron density is small  the semidiurnal
variation in appears even in the case when account is taken of the
diurnal temperature variation only  as regards the departure from
the norm of the height of the result is similar to that obtained
by weiss of except that it is more strongly temperature dependent
there is some interaction between the temperature and the tidal
effects
   /
7968
influence of the moon on the maximum ionization of the ionosphere
e layer  an analysis of e variations over a period of four years
observed at six stations indicates that after taking account of seasonal
solar cycle and equation of time effects there is evidence of a lunar
variation of amplitude centred on the full moon
   /
7969
soft x radiation from the quiet solar corona  the mechanisms involved
in the production of the soft x rays are discussed and the significance
of this radiation for the formation of the normal ionosphere e layer
is indicated
   /
7970
equipment for the measurement of changes of the phase path of ionospheric
echoes  the equipment described is built with units conventional
in pulse applications and is developed from that described f by findlay
and of  oscillograms of ground pulse beats and echo patterns of the
e and f regions are shown
   /
7971
reflection conditions for vertical propagation in the ionosphere
in the presence of collisions and of the earths magnetic field  case
of the e layer
   /
7972
the development of an e region model consistent with long wave phase
path measurements  an electron density model iw evolved by modification
of the chapman theory to include the effects of variable scale height
dissociation of o and variable recombination  the model is checked
against phase height data for and and against values
   /
7973
measurement of attenuation in the ionosphere
   /
7974
the autocorrelogram of randomly fading waves
   /
7975
statistical studies of polar radio blackouts  a statistical study
of high frequency radio blackouts in canada is made from records
taken at several ionosphere sounding stations  both vertical incidence
and communication data are examined to determine the geographical
seasonal and diurnal distributions of the frequency of occurrence
of blackout  it is found that blackouts are most abundant in the
morning and that the time of maximum occurrence increases with increasing
latitude
   /
7976
the microwave properties of precipitation particles  the theory of
scattering and attenuation by rain snow and cloud is reviewed and
theoretical results are presented in the form of equations are presented
in the form of equations tables and graphs so that the radar response
to meteorological particles can be calculated at six wavelengths
and various temperatures  particular emphasis is placed on developments
since rydes comprehensive paper in  published experimental results
are compared with the theory  all results computed from the theory
are contained in tables and  the attenuation by water vapour and
oxygen is given in an appendix
   /
7977
an attempt to observe whistling atmospherics near the magnetic equator
according to the theory of bark hausen and eckersley the mode of
propagation of whistling atmospherics is such that they should not
occur near the magnetic equator  a report is given of observations
made at achimota over the period from december to march no whistlers
were detected though other types of atmospheric were frequent
   /
7978
closed expansion of the convolution integral a generalization of
servomechanism error coefficients
   /
7979
precision high current computer power supplies  a unit supplying
at uses a magnetic amplifier regulated se rectifier
   /
7980
a portable van de graaff generator  the generator described develops
a maximum open circuit voltage of about and has a short circuit current
of
   /
7981
practical local calling circuit  the circuit diagram of an experimental
local station calling device designed for operation on the amateur
band is given and discussed  the unit is basically a transistor receiver
which operates a calling bell via a relay  power consumption is of
the order of per annum
   /
7982
directors annual report on progress in research and technology part
computers and automation  includes a description of the besk digital
computer and notes on the industrial uses of computers and automation
   /
7983
analogue computation in the service of industry
   /
7984
coefficient errors in analogue computers  brief analysis is presented
facilitating assessment of the accuracy of individual computers
   /
7985
the use of a reflected code in digital control systems
   /
7986
a permanent high speed store for use with digital computers  information
is stored in the form of spots arranged in a co ordinate grid on
a slide and is picked up by a flying spot system  reliable operation
should be possible with a digit spacing of if phosphors with low
decay time are used  advantages of the system are high storage density
and commercial availability of the components
   /
7987
system design of the seac and dyseac  standard design procedures
developed during the work on the seac and dyseac digital computers
cover system specifications functional plans and wiring plans  similarity
between these design procedures and data processing procedures
carried out by such computers indicates that existing computers could
be used to produce the wiring plans for new models
   /
7988
the universal relay computer of the institute for low frequency engineering
at the vienna technische hochschule  the simple binary scale
digital computer described was primarily designed to demonstrate
principles for the basic arithmetical operations and the extraction
of t roots  the input is via perforated tape and electromechanical
relays are used both in the store and the computer parts  the times
required are for addition and for multiplication
   /
7989
checking codes for digital computers
   /
7990
a radio frequency nondestructive readout for magnetic core memories
   /
7991
new ferrite core memory uses pulse transformers
   /
7992
asymmetrical finite difference network for tensor conductivities
an extension of the technique described by macneal of
   /
7993
junction transistor trigger circuits  the junction transistor with
earthed emitter is sufficiently similar to the thermionic valve with
earthed cathode to enable it to be used in conventional trigger circuits
details are given of bistable monostable and emitter coupled trigger
circuits multi vibrators a scale of two circuit and a blocking oscillator
pulses of duration down to about can be produced  power consumption
is of the order of per stage
   /
7994
rotary and slider potentiometers with variable characteristic  any
resistance slider position characteristic can be approximated by
connecting suitable resistors in parallel with short sections of
the potentiometer
   /
7995
investigations of current noise in resistors  report of noise voltage
measurements over the frequency range kcs  with film resistors the
mean square noise voltage usually varies approximately inversely
as frequency for resistors exhibiting such a frequency variation
the noise is proportional to the direct voltage applied  deviations
from this frequency dependence are accompanied by deviations from
this voltage dependence as reported by macfarlane of  the behaviour
of wire resistors is similar  the statistical distribution of amplitude
of the current noise agrees with the distribution function for thermal
noise indicating that its nature is gaussian
   /
7996
linear reactor chart  design data are presented for iron core reactors
with inductance unaffected by variations of dc through the winding
or alternating voltage across it
   /
7997
light sensitive neon tube circuits  the decrease in the striking
voltage and the slight increase in the dark current produced by external
illumination in low voltage neon lamps is mac made use of in switching
lf relaxation oscillator and other circuits  high power illumination
glow lamps may also be suitable
   /
7998
a mathematical technique for the analysis of linear systems  comment
on
   /
7999
calculation of the oscillation frequency of a quartz crystal maintained
by a transistor  calculations are made for high q and for low q crystals
values of the frequency variation are tabulated for a range of
values of detuning of the oscillator circuit connected to the transistor
collector
   /
8000
an rf resonant circuit for use at mcs  circuits of inductive line
type with a tuning range have been designed without metallic sliding
or rotating contacts  the construction may be of low loss plastic
with plated or printed conductors  eccentric coaxial or two wire
arrangements are used
   /
8001
understanding the cyrator  an equivalent network is used to show
that gyrators can be simply realized by means of current or voltage
generators
   /
8002
rlc lattice transfer functions
   /
8003
a general theory of wideband matching with dissipative poles
   /
8004
effect of a radio pulse signal on resonant circuits  calculations
are made of the time required to establish the signal in a circuit
of given bandwidth and time constant  it is not possible to establish
any simple relation between these parameters except in the case when
the signal frequency is the same as the resonance frequency  the
influence f of signal duration is studied  the results are of importance
in connection with radiotelegraphy and explain the occurrence of
maxima at the beginning n and end of each signal
   /
8005
transformation for constant impedance networks  certain constant
impedance networks having a restricted range of variation of loss
often contain components which are difficult to manufacture  the transformation
which is described overcomes this difficulty at the expense
of two extra resistors in the network and a small amount of frequency
independent loss added to the characteristics  another application
is the absorption of inductor dissipation in special cases
   /
8006
a chart for analyzing transmission line filters from input impedance
characteristics  use of smith chart techniques is demonstrated
   /
8007
compilation of a filter catalogue  a discussion of the desirable
features of a catalogue in which all numerical data required in designing
reactance quadripoles by the insertion loss method are assembled
an appendix gives formulae linking the reflection factor and four
insertion loss parameters  values of the insertion loss parameters
are tabulated for values of reflection coefficient ranging from to
in unit steps
   /
8008
novel uses of the ultrasonic light cell
   /
8009
the generation of undamped electrical oscillations in series and
parallel oscillatory circuits  a formal analytical treatment showing
the types of negative resistance characteristic necessary for generating
sinusoidal oscillations in the two types of circuit
   /
8010
on the extension of the principle of imaginary power balance of harmonics
to circuits with continuous spectra  extension of the principles
given in a previous paper on the interdependence of frequency variations
and harmonic content in oscillators
   /
8011
the nonlinear theory approach to resistance capacitance oscillators
exact calculations can be made using nonlinear theory based on the
balance of the reactive power of the harmonics involved  the analysis
indicates that the frequency stability when operating near the limit
conditions is generally better with rc than with cr networks
   /
8012
the influence of grid current upon valve oscillator frequency  analysis
indicates tht when the intensity of harmonics in the oscillator anode
and grid circuits is low the fundamental component of grid current
is the main factor influencing oscillation frequency  grid current
harmonics have b a greater influence than anode current harmonics
   /
8013
frequency stabilization of valve oscillators in respect of grid current
amplification factor and load  formulae are derived for determining
the values of stabilizing reactances for series connection in the
grid anode and load circuits
   /
8014
the operation and loading characteristics of valve oscillators for
dielectric heating
   /
8015
designing stable triode microwave oscillators  two circuit constructional
arrangements are described using a planar triode type and suitable
respectively for operation at frequencies of and
   /
8016
perturbations in nonlinear filtered systems  applications to the
theory of oscillators  conventional methods of studying feed back
amplifier stability can be applied to separable filtered systems
comprising a nonlinear frequency independent unit followed or preceded
by a linear selective circuit of and back references  the theory
of free and synchronized modes is extended to the case of frequency
division  stability is investigated by introducing two different
coefficients for the in phase and quadrature components of the perturbation
voltage so that the system can be treated as an amplifier with
two feedback loops  the method is applied to determine the effect
on the output of a valve oscillator due to lf modulation at the grid
   /
8017
pulse generator using secondary electron emission valves  the generator
described produces positive and negative voltage pulses with duration
adjustable between and sec and a rise time of about as well as cro
beam brightening and sweep voltages
   /
8018
a versatile pulse shaper
   /
8019
transistor waveform generators  design of circuits using point contact
and junction transistors is considered on the basis of analogies
with thermionic valve circuits  experimental af tuned circuit crystal
controlled and blocking oscillators are described
   /
8020
fractional frequency generation by regenerative modulation  the circuit
theory is similar to that presented previously for frequency multiplication
of  an arrangement is described producing six frequencies lower
than input as well as others higher than input
   /
8021
a high speed waveform sampling circuit  pulsed sampling circuits
are discussed for obtaining a quantized output corresponding to a
continuously varying input voltage  a cathode follower with negative
feedback is used to provide an arrangement giving sz satisfactory
operation with sampling pulses of short duration and small amplitude
a diode switch circuit leads from the cathode follower to the input
of a sign reversing amplified between whose input and output terminals
the storage capacitor is connected
   /
8022
design for a watt high quality amplifier  discussion i with emphasis
on the output stage and with special reference to the application
of type a output pentodes
   /
8023
amplifiers and preamplifiers  a practical discussion covering the
operation design construction and testing of all types of amplifiers
used in home music systems and a presentation of the interesting
features of commercially available products
   /
8024
selectivity and delay distortion in high frequency amplifiers  in
designing wide band amplifiers or filters a compromise must be reached
between the conflicting requirements of linearity of phase characteristic
maximum amplification and selectivity  normalized curves for the
attenuation phase and transient response characteristics of four
different amplifiers with four tuned coupling circuits are presented
and discussed from the point of view of design to meet specific requirements
the four types of amplifier considered are those with single
tuned circuits those with flat phase characteristic power law and
tchebycheff
   /
8025
parallel series amplifier  high amplification stability and low output
impedance are achieved in a direct coupled circuit containing only
two resistances one in the common cathode lead of a parallel connected
double triode the other as the anode load of the first triode whose
anode is also connected directly to the grid of a third triode in
series with the second  the output voltage is that between the anode
of the second triode and the reference voltage input  under appropriate
conditions amplification where refers to the slope of the double
triode  the operation of the circuit is analysed and its application
as an amplifier for an analogue computer a voltage stabilizer or
a dc amplifier is described
   /
8026
studio amplifier design for color television  distribution amplifiers
with highly linear phase characteristics over a wide frequency range
are obtained by using multistage feedback amplifiers with rc couplings
having different time constants
   /
8027
high speed magnetic amplifiers  an alternative arrangement using
a junction transistor for coupling a junction transistor for coupling
is described
   /
8028
a survey of magnetic amplifiers  principles of operation and basic
circuits are described and applications are indicated
   /
8029
diode amplifier
   /
8030
delay line subcarrier discriminator  the frequency discriminator
described uses a multivibrator triggered by the direct input signal
and stopped by the delayed signal producing pulses whose spacing
is a function of signal phase  designed primarily for telemetering
it is useful also for automatic correction of wow and flutter in
tape recorders
   /
8031
an electrostatic problem involving a nonlinear fluid dielectric
an approximate calculation is made of the electrostatic couple on
an anisotropic dielectric sphere influenced by a uniform field dielectric
   /
8032
slit middle plate capacitors a contribution to the technique of calculation
of potential fields  a numerical calculation is made for a system
coo parallel plates distant respectively cm z and cm on opposite
sides of a third parallel plate with a slit cm wide  the results
are compared with electrolyte trough measurements
   /
8033
theory of the diffusion of light by strongly piezoelectric crystals
expressions are derived for the variations of electric susceptibility
produced in the crystal by passage of a wz wave of thermal agitation
   /
8034
kinetic temperature of electrons in metals and anomalous electron
emission  the effect of strong electric fields on metals is to raise
the temperature of the electrons above that of the lattice  the symmetrical
part of the electron energy distribution is a ferm distribution
function the asymmetric part is negligible in the cases considered
quantitative estimates of the effect of the electron temperature
rise on conduction and emission are briefly discussed
   /
8035
effect of strong electrostatic fields on the resistance of tungsten
wires in high vacua  wires of diameter and were subjected to negative
and positive radial fields of strength up to and cm respectively
the resistance decreased abruptly on applying the field and increased
abruptly on removing it regardless of its sign the change of resistance
was proportional to the square of the field strength  no explanation
of the effect has been found  slight increases of resistance during
steady application of the field are associated with temperature increases
attributed to effects of ion photo and field emission currents
   /
8036
the theory of the magnetoresistance effects in polar semiconductors
theory developed previously for conduction in polar semiconductors
of is extended to deal with effects occurring in the presence of
a magnetic field  hall coefficient and magnetoresistance effect are
shown graphically as functions of the magnetic field strength and
of the temperature and degree of degeneracy of the electron gas
at low temperatures the magnetoresistance effect may become very
large contrary to the prediction of the free path theory
   /
8037
theory of skin effect in constant magnetic field  the surface impedance
is calculated for the case of a metal surface parallel to the magnetic
field  an analogous treatment for a normal field was given earlier
by azbel and kaganov of
   /
8038
current distribution in cylindrical conductors of circular cross
section  a calculation is made of the current distribution and joule
heating for the conductor in a uniform alternating magnetic field
   /
8039
the electron avalanche and its development in the self maintained
discharge  a survey of the primary and secondary processes la leading
to breakdown in a parallel plate system in a gas
   /
8040
departure from paschens law of breakdown in gases
   /
8041
breakdown processes in nitrogen oxygen and mixtures
   /
8042
influence of insulating films on the corona current and breakdown
voltage of spark gaps  experiments are reported in which a point
to plate discharge path was used the plate being coated with lacquer
or other insulator observed breakdown voltages are in some cases
lower than with an uncoated plate  an explanation of the results
is presented
   /
8043
the effect of lacquer films on the ac corona on points and wires
   /
8044
two different breakdowns between a positive electrode with small
curvature and a plane  experiments made using loops of different
radii in combination with a plane are described
   /
8045
some peculiarities of the current potential characteristics of positive
corona discharge
   /
8046
indication of the development stages of positive corona discharge
in the atmospheric air  experimental technique is described for investigating
the development of the discharge by means f the various optical
acoustic and electrical effects involved the correlation between
these effects is demonstrated
   /
8047
radiation of plasma noise from arc discharge  radiation from cold
cathode dc are discharges in air has been observed at frequencies
of and  the oscillation is thought to be generated by periodic electron
emission from the cathode caused by a small perturbation of the potential
gradient due to variation of the ion sheath potential
   /
8048
electron resonance in gas discharges  brief description f experiments
in which absorption lines were observed by paramagnetic resonance
technique using a cavity resonator constructed so that the gas discharge
occupied the region of maximum microwave magnetic field strength
the results indicate that this may constitute a sensitive method
for studying the variation of concentration of free ions
   /
8049
space charge effects in a high frequency discharge  details of experimental
work on the effect reported in of  the current flowing in a
circuit connecting the external electrodes and including a high resistance
r is measured and its relation to the applied voltage and to
the pd between the internal electrodes examined  when r is very high
discontinuities in the characteristic and hysteresis effects are
observed with change in applied voltage  the latter are studied in
further detailed oscillograms  a theoretical explanation of the results
is discussed
   /
8050
noise of gas discharge plasma  measurements were made in the frequency
range on a discharge in a tube containing argon and hg vapour at
a pressure of about mm hg probe currents of and were used  current
noise was approximately proportional to as with semi conductors
see also of
   /
8051
an evaluation of plasma ion temperature  measurements made by the
double probe ad and other methods are reported
   /
8052
energy distributions of field dependent secondary electrons  report
of an experimental investigation of the emission from thin films
of a retarding field technique was used  the energy distribution
was found to be maxwellian with values ranging from zero to and average
values of to depending on the applied field  the method is useful
for determining the surface potential of the emitter
   /
8053
experiments on the behaviour of an ionized gas in a magnetic field
probe measurements in a plasma comprising electrons and helium ions
in a toroidal tube with a toroidal magnetic field reveal an oscillatory
current which is interpreted as indicating fluctuations of ion concentration
consistent with magnetohydrodynamic waves of the type described
by alfven of  microwave measurements on a toroidal cavity resonator
indicate that the degree of diffusion control in helium at low pressure
is very much less than expected from the classical theory of ambipolar
diffusion of ions and electrons in a magnetic field  the diffusion
coefficient magnetic field curve passes through a minimum at about
tentative explanations of the experimental results are advanced
   /
8054
various ways of using cavity resonators in paramagnetic resonance
note on operating conditions for greatest sensitivity in signal detection
the cavity resonator not being matched to the guide  cases considered
are oscillator tuned to cavity resonance frequency ratio of reflected
to incident power and oscillator frequency varying around resonance
frequency
   /
8055
i ifield equations for a fluid electromagnetic field system  a relativistic
generalization is presented of the macroscopic equations of
electromagnetism
   /
8056
cauchys problem in relation to a fluid electro magnetic field system
equations derived previously above are studied by an analysis of
cauchys problem
   /
8057
reflection of a transient electromagnetic wave at a conducting surface
a treatment of oblique incidence reflection from the plane interface
of a dissipative medium  the inversion of the laplace transforms
can only be carried out in closed form in special cases  series solutions
are developed for the general case and numerical results are presented
graphically  a possible application of the results to the case
of a lightning discharge waveform and reflection from a sharply bounded
ionosphere is noted
   /
8058
an integral equation governing electromagnetic waves  the problem
discussed is that of determining the solution of the helmholtz equation
for the region outside a simple closed curve boundary at which values
of u or its normal derivatives are prescribed  by introducing a suitable
parameter constructed by conformal mapping the problem is reduced
to a new fredholm integral equation whose solution is independent
of conditions inside the boundary  scattering cross section is discussed
   /
8059
greens functions for the cylinder and the sphere  the investigation
of diffraction of is continued  the exact expression for the greens
function is split into two parts corresponding respectively to the
geometrical optics wave and the surface wave  a semi asymptotic solution
is thus obtained which is valid for quite small obstacles  the surface
waves are shown to be identical with the residual waves discussed
by watson and by van der pol and bremmer in connection with wireless
telegraphy
   /
8060
backscattering from wide angle and narrow angle cones  solutions
are obtained for the diffraction of the waves radiated by scalar
and vector point sources on the axis of a semi infinite cone  the
scalar problems are solved by the method of characteristic greens
functions to yield directly various alternative representations whose
different convergence properties are discussed the vector problem
is solved by an application of spherical transmission line theory
to evaluate the plane wave scattering observed far from the cone
tip a highly convergent contour integral representation is selected
and evaluated approximately for the special case of backscattering
from cones having large and small apex angles  the results for the
large angle cone exhibit the transition from a backscattered spherical
wave to a plane wave as the cone degenerates into an infinite plane
   /
8061
measurement of microwave diffraction from a long slit in a thin conducting
plane  an outline is given f of technique used to produce a uniform
incident plane wave  results of measurements of the intensity of
the diffraction field are shown graphically for longitudinal and
transverse polarization of the incident wave
   /
8062
diffraction by apertures  theoretical and experimental investigations
are reported of the diffraction of plane em waves by circular and
elliptical apertures in plane screens  integral equations are derived
for the distribution over te the apertures and the aperture transmission
coefficient is determined by a variational method  the closeness
f of the agreement between experimental and theoretical results shows
that the method is capable of providing good approximations to the
actual field values  the measurements were made in the band using
an image plane technique
   /
8063
the edge conditions and field representation theorems in the theory
of electromagnetic diffraction  discussion is presented relevant
to the case of a perfectly conducting screen of infinite extent with
an aperture of finite area  order conditions are developed which
must be satisfied by the field components in the neighbourhood of
the edge as a consequence of the requirement that the total energy
in a finite c volume must be finite  the boundary value problem is
formulated as a pair of simultaneous integral equations  from the
solution for the edge region the functional form of the local fields
can be determined without assuming a particular type of expansion
an indeterminacy present in the system of local integral equations
can be removed when the local behaviour of certain field components
is known in detail
   /
8064
simultaneous partial absorption reflection and transmission of a
uniform plane wave by a thin metal layer  simple analysis is used
to derive expressions for the energy reflected transmitted and absorbed
for a normally incident wave  for given conductivity the absorbed
energy has a maximum value of half the incident energy at a particular
value of thickness the reflected and transmitted energies being then
equal
   /
8065
thermodynamical theory of galvanomagnetic and thmomagnetic phenomena
   /
8066
spin echo memory device  a proton rich sample placed in a strong
inhomogeneous magnetic field of mean strength h was subjected to
a pattern of relatively weak radio frequency pulses at the larmor
frequency of the protons in the field h  the pattern was then recalled
by applying a strong rf pulse at a later time as in the spin echo
technique  it is shown both mathematically and experimentally that
such a series of pulses varying in amplitude can be memorized by
the spin system of protons for times as long as one second and then
repeated preserving both shape and relative amplitude  spin echoes
are discussed by hahn in
   /
8067
the distribution of temperature along a thin rod electrically heated
in vacuo part time lag  expressions obtained previously of february
for the steady state temperature distribution are used to study the
increase of temperature accompanying a small increase in heating
current  over a considerable region near the centre of the rod the
temperature variation can be completely represented by a simple exponential
law involving a single relaxation time whose magnitude can be
readily calculated  this method is compared with that based on the
fourier expansion the latter can be adapted for general use by introducing
an effective length to replace the actual length of the rod
for a given temperature at the centre the relaxation time varies
inversely as the ratio of surface to volume and is thus smaller for
a ribbon filament than for one of circular cross section as observed
by prescott and morrison vol
   /
8068
radio astronomy in hawaii  observations are being made of cosmic
noise at frequencies near and using a lloyds mirror technique  the
interference patterns observed are discussed in relation to the nature
of the sources and to ionospheric and solar variations
   /
8069
interferometer observations of solar radiation at  the distribution
of brightness over the solar disk has been studied by observations
at marcoussis subsequent to those reported previously of  the sensitivity
of the system was sufficient for reliable measurements of interference
of magnitude down to the results confirm that at this frequency
the suns apparent diameter is slightly greater than for the visible
disk and limb brightening is present
   /
8070
new array for radio astronomical observations of the suns brightness
at  equipment installed at marcoussis comprises four identical parabolic
mirrors of diameter located respectively at and along an line where
the four aerials are connected to a single receiver by lines of equal
length  the overall length of this array is as compared with for
a continuous mirror to give the same ha half power lobe width  the
arrangement enables the first six fourier harmonics of the brightness
distribution over the sun to e be observed at true amplitude
   /
8071
the apparent specific resistance of an inclined plane stratum
   /
8072
fundamental types of geomagnetic activity  k indices obtained from
observations at irkutsk geomagnetic latitude watheroo slutsk and
tashkent are compared and discussed  the average k indices and st
variations for irkutsk are presented graphically
   /
8073
establishment of a new process of terrestrial demagnetization period
of the latest demagnetization cycles recorded for our planet  analysis
of figures from observatories covering the whole world indicates
oscillations in the intensity of the terrestrial magnetic field since
an average period of years i is inferred for the remagnetization
demagnetization cycles
   /
8074
solar corpuscles responsible for geomagnetic disturbances  a qualitative
hypothesis is presented
   /
8075
annual variation of the magnetic elements
   /
8076
note on the occurrence of world wide sscs during the onset of negative
bays at college alaska  sudden commencements followed by a period
of storminess may have an atmosphere source which is related to sudden
changes in auroral activity
   /
8077
geomagnetic activity and sunspots  analysis of observations by the
method of superposed epochs shows that geomagnetic activity following
the central meridional passage of certain sunspots is related more
closely to their rf radiation than to their eruptive intensity
   /
8078
correlation between the solar corona and the geomagnetism for the
remarkable m regions in
   /
8079
on the distribution of refractive index in the lower atmosphere in
japan  radiosonde data for heights up to are analysed  contour maps
show the derived distribution of effective earth radius factor for
day and night in each month of the year the distribution is closely
related to the movement of the air mass  predicted values of field
strength for over a path are generally greater for summer than for
winter in agreement with observed values
   /
8080
tidal oscillations of the lower stratosphere  diurnal and semidiurnal
variations of wind occurring in the lower stratosphere appear
to be associated with solar tides  the semidiurnal variation in the
stratosphere is in phase with and of comparable magnitude to the
semidiurnal variation at the earths surface  the diurnal variation
in the stratosphere is of similar magnitude to the semidiurnal variation
   /
8081
viscosity in the high atmosphere
   /
8082
widespread diurnal variations of effective slope of the ionosphere
measurements have been made at seagrove radio research station nz
of the bearing and elevation angles of signals received on from nandi
fiji distant almost magnetically north and on from brisbane queensland
distant almost magnetically west  from these measurements the effective
slopes of the ionosphere are found to be related at places about
apart and the average diurnal variation of these slopes is determined
   /
8083
storms in the ionosphere  a general survey of existing knowledge
and theories of the world wide disturbances in the upper structure
of the ionosphere observed at times of magnetic storms  the effects
on long distance short wave communication are briefly indicated
   /
8084
behaviour of the ionosphere at rome during the period  ionosphere
records obtained at rome are analysed the normal variations are established
predicted values of are shown graphically
   /
8085
movement of the f region  using three spaced receivers continuous
recordings were made in massachusetts during the period august december
of a vertical incidence and two oblique incidence pulse transmissions
the base lines for the latter being km and km in directions roughly
we and nw se  horizontal speed and direction of winds in the f region
were determined from the time displacement of echoes  at an average
virtual height of average speed was and mean direction nearly parallel
to the earths magnetic field  monthly averages of mean direction
showed a semiannual period with maximum deviation e of n around the
equinoxes  monthly  verages of speed varying between  nd sh  w  d
n  annual  period with higher values in winter than in summer  speed
increased with height
   /
8086
intermediate layers of ionization between the e and f layers of the
ionosphere over ahmedabad n e  observations are reported indicating
the regular occurrence of two intermediate layers with virtual heights
of km and km respectively  both layers exhibit magneto ionic splitting
the variation of the critical frequencies with the suns zenithal
angle obeys a cos law the value of n being about  true heights and
thickness of the layers are determined for some cases the values
of true heights are in good agreement with rocket observations
   /
8087
geomagnetic control of the f region of the ionosphere  noon values
of and for march june and december of and plotted against geomagnetic
latitude show the same type of geomagnetic control  the equatorial
dip in the f curves is more pronounced in the year of higher u sunspot
activity  see also of
   /
8088
a measurement at ottawa of the change in height with lunar time of
the e region of the ionosphere  the method used by appleton and weekes
to detect the lunar variation of height of the e region of the ionosphere
has been used to determine the amplitude and phase of the lunar
height variation at ottawa  observations were made from october to
december  a sinusoidal variation of height of amplitude and period
was observed  the maximum height occurred about six hours after lunar
transit  this result differs in phase by six hours from that observed
in cambridge in
   /
8089
continuous radar echoes from meteor ionization trails  preliminary
results are presented of experiments giving support to the view that
meteoric ionization is the most important factor in extended range
chf propagation
   /
8090
interpretations of radio reflections from the aurora  report and
discussion o of measurement made at ithaca ny  pulse radar experiments
at show that reflections occur only during aurorae having ray structure
the transmitted beam must be directed roughly normal to the rays
echoes are complex  cw signals at various frequencies between and
showed a rate of fading roughly proportional to frequency ie much
higher than the fading rate for normal ionospheric conditions  observations
are interpreted as indicating that echoes are due to scattering
from numerous auroral columns of ionization fading is due to wind
like motion of these columns  other interpretations are critically
discussed  reasons are given for the possible occurrence of auroral
reflection at f region as well as e region levels
   /
8091
more about vhf auroral propagation  radio amateur reports of auroral
propagation at since indicate an extended communication range along
ew direction rather than ns  automatic recordings at show a predominance
of auroral reflection around and am est an unexplained dip in the
diurnal curve at midnight a marked seasonal trend and a decrease
in occurrences from to in cw and radar experiments at college alaska
in echoes came from far north of the auroral zone with ranges above
km and never from the south reflections probably oy occurred at heights
of angles of elevation were low no matter where visible aurorae occurred
   /
8092
variations of the terrestrial magnetic field in hungary  in russian
english french and german  the text of this survey is given in hungarian
russian and german
   /
8093
three examples of electrical servomechanism engineering  servo mechanism
system design problems treated by graphical methods which are explained
include regulation of the output voltage of a constant speed independently
excited dc generator and two cases of motor speed control
   /
8094
component design trends metallic rectifiers approach infinite life
developments in cu se si ge and rectifiers are surveyed new designs
give reduced size and longer life together with higher operating
temperature output current and reverse voltage ratings
   /
8095
highly stable medium voltage direct and alternating sources for test
purposes  a review of methods of stabilizing supply voltages up to
about and a note on methods of measuring small changes of alternating
voltage  see also of
   /
8096
a cascode amplifier degenerative stabilizer  description of stabilizers
with modified cascode shunt amplifiers having gain
   /
8097
generation of high voltage by charge transport on rotating insulator
surfaces
   /
8098
computer for universal application  brief description of deuce a
commercially available computer developed from the ace it has punched
card input and output systems mercury delay lines for short term
storage and a magnetic recording drum for long term storage  the
total floor space occupied by the equipment is by in
   /
8099
an outline of an electronic arithmetic unit  discussion of the design
of a digital computer unit capable of performing and checking the
operations represented by a b d c
   /
8100
pulse switching circuits using magnetic cores  design theory is presented
for nonstorage uses of cores with rectangular hysteresis loops
in digital computers  to facilitate determination of the sense of
the em processes a method of representation due to mayer is used
in which the magnetic circuit elements are replaced by elements of
a mirror system  devices for eliminating output voltage on shuttling
the core are discussed  operating frequencies are attainable references
   /
8101
a statistical method for solution of the laplace differential equation
using electronic computers  an electrical analogue of the galton
board is used in which the rolling balls are replaced by pulses and
the pins by pulse storage units
   /
8102
analogue machine for calculation of the complex index of a body from
its reflection coefficient  a resistance network is discussed by
means of which the phase shift of light reflected by a body can be
calculated if the reflection coefficient is known for all wavelengths
the refractive index can hence be determined
   /
8103
the function of basic elements in digital systems  the three basic
elements of digital computers are a bistable element for storing
a digit a gate for controlling the passage of a digit a diode for
controlling the direction of passage  a unit in the form of a beam
deflection valve has been designed including a bistable element together
with two gating elements  see also below
   /
8104
the geometric transformation of impedance diagrams  an extension
of the work of briner and graffunder of to the general case  for
a correction to the earlier paper see dec
   /
8105
barkhausen noise from a cylindrical core  the method used by krumhansl
and bayer for calculating barkhausen noise of is simplified by considering
an exciting field with a sawtooth rather than a sinusoidal waveform
   /
8106
the variation with current and inductance of metal transfer between
platinum contacts  continuation of investigation described previously
of warham  curves of the net transfer are given for currents and
inductances in the ranges and respectively  four different types
of transfer termed bridge short arc long arc and reversed short arc
may be involved  the results indicate that the life of pt contacts
could be improved by controlling the effective circuit inductance
at break to about
   /
8107
analytical approach to the variable turns ratio autotransformers
   /
8108
high frequency amplification using transistors  measurements were
made on transistors type oc and oc in the grounded base connection
to assess them for use in narrow band if amplifiers  the voltage
feedback effect may lead to instability hence neutralization is essential
at the higher frequencies the stage gain is reduced mainly by
the base resistance and the collector barrier capacitance
   /
8109
theory of equivalent circuits for junction transistors  an equivalent
circuit is discussed which differs from that of pritchard of only
in respect of the arrangement of the current and voltage sources
a simplified equivalent circuit including a triode valve is also
presented
   /
8110
the frequency dependence of transistor quadripole parameters  the
grounded base connection only is considered  oertels equivalent valve
circuit above is a satisfactory approximation up to a frequency about
half that of cut off but a proper description of rf performance requires
the addition of a base resistance and leakage conductance to the
basic equivalent circuit  measurements on a type oc transistor show
satisfactory agreement with theory
   /
8111
field theory of wave propagation along coils  expressions are derived
for phase and group velocities and surge impedance in air cored and
iron cored coils and transformer windings  theoretical and experimental
data for frequencies up to are compared
   /
8112
the design of coils for the production of high magnetic fields  design
curves are presented for coils of rectangular cross section for producing
intense transient magnetic fields using energy obtained from a
bank of charged capacitors
   /
8113
a reversible binary counter  a multivibrator type counter performs
addition or subtraction depending on application of a control signal
to a two gate system interposed between consecutive counter stages
the control signal may be obtained from a multivibrator circuit similar
to the counter stages  applications in digital analogue conversion
and in an interpolator are discussed
   /
8114
transistor choppers for stable dc amplifiers  two fused junction
transistors driven at power frequency are used in a switching circuit
for converting weak dc input signals into proportional square wave
ac signals
   /
8115
multi electrode counting tubes  applications other than straightforward
counting operations are discussed for decimal counting tubes of various
types  the design of a pulse amplitude analyser using trochotrons
and dekatrons in a matrix system is outlined  the life of the tubes
is comparable to that of ordinary valves
   /
8116
investigations of laboratory production of printed circuits for communication
equipment  a brief report is presented on the practical aspects
of very small scale production of printed circuits using the simplest
tools only  th electrical and mechanical properties of different
chassis materials are tabulated as well as the properties and the
treatments required by seven different conducting materials  applications
described include the production of components an amplifier a
rc oscillator and a heterodyne receiver for the frequency band this
receiver contains no inductive components see also of
   /
8117
piezoelectrically activated low frequency mechanical resonators
discussion of resonators comprising plates or bars carrying two relatively
small piezoelectric crystals  the parameters of the equivalent
electrical quadripole are determined for flexural modes of some circular
chladnis plate type resonators  application to stabilization of sinusoidal
oscillators is briefly described
   /
8118
on the physical realizability of linear nonreciprocal networks  the
necessary and sufficient conditions are given that a matrix with
arbitrary complex number elements be the impedance admittance or
scattering matrix of a physical linear reciprocal network  a canonical
form for non reciprocal network synthesis is presented which applies
to any linear n terminal pair n port system at any fixed frequency
if the network i is passive the only circuit element required in
addition to lossless inductors capacitors transformers and positive
resistors is the gyrator  if the network is active negative resistors
and gyrators must be used in addition to conventional passive elements
some discussion of matrixes with frequency variable elements is also
given
   /
8119
transient responses with limited overshoot  the problem is considered
of designing a system transfer function such that in the response
to a step function input the overshoot shall be limited and consist
largely of the principal mode of oscillation  a method is stated
by which the size of any real term in the response may be calculated
relative to the maximum value of the principal model  graphical conditions
are given restricting the permissible pole and zero positions
in certain cases when this ratio is specified  the procedure is illustrated
by examples
   /
8120
design of parallel t resistance capacitance networks  formulae are
derived for networks having a transfer characteristic symmetrical
with respect to resonance frequency and a minimum loss for a prescribed
frequency discrimination
   /
8121
symmetrical quadripoles operated as asymmetrical transformers  a
theoretical investigation is presented of the behaviour of passive
linear quadripoles in asymmetrical operation  the analysis is based
on introduction of the characteristic iterative impedance  multisection
band pass filters with different output and input impedances are
built up with sections which have similar frequency characteristics
and phase constants but geometrically graduated impedances  a numerical
example is given of a transformation for the frequency band
   /
8122
the initial transient behaviour of filters with characteristic amplitude
response  the distortion of a step voltage input by butterworth type
and tchebycheff type filters is analysed  calculations are made for
all pass equalizing networks for the former type
   /
8123
a note on time series and the use of jump functions in approximate
analysis  the response of filters to jump function inputs is investigated
jump transfer functions and serial operators for common types
of filter are tabulated  the method is compared with that described
by tustin
   /
8124
the matrix approach to filters and transmission lines  use of matrices
provides a direct and flexible method of treatment  a simple graphical
procedure is indicated for investigating filter characteristics
   /
8125
a new method of determining correlation functions of stationary time
series
   /
8126
the transient response of rf and if filters to a wave packet
   /
8127
a novel microwave attenuator using germanium  the device comprises
a thin rectangular slab of ge set obliquely across a waveguide with
current leads attached to the two ends and a magnetic field applied
parallel to the face of the slab so as to control the concentration
of current carriers as described by weisshaar and welker of  attenuation
of db was obtained with a pulsed control current of
   /
8128
the hybrid ring a hybrid circuit for very high frequencies  input
admittance and coupling attenuation are calculated as functions of
frequency good agreement with measured values is obtained  methods
of increasing bandwidth are discussed and a practical arrangement
is described for the band using a construction similar to microstrip
   /
8129
suggestions on constructing oscillators  the operation of various
valve and transistor oscillators is analysed  fixed and continuously
tunable oscillators pulse generators and two frequency oscillators
for special applications are discussed
   /
8130
the generation of millimetre waves  theory is presented for spark
generators experimental evidence generally supports the theory  useful
results can only be obtained with sparks in oil
   /
8131
ultra low frequency oscillator  a cr circuit using resistors and
polystyrene capacitors of moderate values is described for obtaining
oscillations at frequencies down to  the effective value of the resistance
is increased by use of the cathode follower effect
   /
8132
parallel network oscillators  general principles are discussed of
electronically tunable wide band oscillators having two signal paths
with their outputs added and a common feedback path the tuning is
performed by differentially controlling the gain in the two paths
eg by push pull modulation  particular arrangements described include
a twin triode circuit using an artificial transmission line network
giving a tuning ratio and a four valve circuit with lead and lag
networks giving a frequency range nearly independent of centre frequency
amplitude constancy stability waveform and noise are examined
   /
8133
a simple quartz crystal oscillator driven by a junction transistor
the transistor is connected with grounded base and the quartz crystal
is operated in its series mode  the frequency range is up to about
and the output power up to about
   /
8134
four decade frequency divider  division of any frequency from sub
audio to by any whole number up to is accomplished by a direct reading
divider using binary counter circuits
   /
8135
design of coaxial cavities for valves with planar electrodes  the
cavities form the double coaxial line structure used in conjunction
with a disk seal type valve for grounded grid operation as amplifier
or multiplier  a graphical method of design is presented which involves
only functions of the characteristic impedance once the operating
mode has been chosen  criteria are explained for determining the
diameters of the two cavities for optimum response  for higher mode
operation the response can be improved most easily by the introduction
of a suitable discontinuity  three types are considered  the occurrence
of spurious resonances is also discussed
   /
8136
design of hf and if amplifiers for multi channel fm links  bandwidth
required is determined from the side band amplitudes for given modulation
index and from the permissible distortion  expressions for involve
the derivatives of the amplifier response curves and are tabulated
for single stage circuits and two stage band pass filters  the computation
for multistage circuits is shown to involve the same derivatives
under ideal conditions second harmonic distortion would be eliminated
by exact tuning to the central frequency and third harmonic distortion
sufficiently reduced by using symmetrical filters with a coupling
coefficient  in practice tuning is not exact but second harmonic
distortion can be kept at a tolerable level by adjustment of the
pass band response at the alignment stage  valve capacitance variations
are allowed for in the shunt circuit capacitance  neutralization
can practically eliminate the effects of feedback via grid anode
capacitance  criteria for the choice of if are explained
   /
8137
circuit design factors for audio amplifiers  close regulation of
the anode supply of a cathode follower driver stage in a power amplifier
is achieved by using a regulator triode operated by a diode connected
to the driven grid  circuits discussed include improved versions
of williamson and ultralinear amplifiers
   /
8138
design for a watt high quality amplifier part  details are given
of the circuit lay out and performance of an amplifier with an output
stage of two type el high slope pentodes in push pull with partial
screen grid loading  part of july
   /
8139
a new circuit for balancing the characteristics of pairs of valves
a more detailed account of the work described previously of april
   /
8140
vx band receiving amplifier  a regenerative klystron amplifier is
described suitable for use in a microwave television receiver having
a gain at with a bandwidth of
   /
8141
problems of magnetic pre amplifiers  the topics discussed include
the quality the effect of core shape on the magnetization characteristic
effect of characteristic of valve or semi conductor rectifier on
amplification and effects of incomplete magnetic decoupling of input
circuit
   /
8142
representation of physical quantities in formulae tables and coordinate
systems  a comprehensive discussion covering both fundamental physical
principles and typographical aspects
   /
8143
a new system of logarithmic units
   /
8144
proposal for a new aether drift experiment  a method of greater sensitivity
than essens of uses a resonant cavity to produce a phase change
in a signal form a fixed frequency oscillator
   /
8145
derivation of the laws of relativistic electro dynamics for a vacuum
from the energy quantum model  theory developed previously of june
is extended to include the case of systems in motion
   /
8146
wave mechanics theory of electron optical image formation part
   /
8147
electrostatic averaged boundary conditions for wire mesh  a brief
review is given of the existing methods for determining the screening
effect of a mesh and a general derivation is proposed of the boundary
condition for a mesh by the method of averaging the field  the results
obtained are applied to the determination of the screening effect
of an earthed uniform spherical mesh with respect to a charge or
a dipole placed at the centre and also to the determination of the
effective potential in a triode  see also below
   /
8148
the field due to an infinite dielectric cylinder between two parallel
conducting planes  if the cylinder radius b is sufficiently small
compared with the other dimensions involved the change of capacitance
due to its insertion between the plates can be made proportional
to where k is the dielectric constant of the cylinder  for a conducting
cylinder k is put equal to infinity  applications include the measurement
of the departure from uniformity of threads
   /
8149
the ionic conductivity of dilute potassium chloride solutions at
centimetric wavelengths  measurements on solutions in the concentration
range normal at a frequency of indicate the existence of a strong
dispersion region at concentrations below normal which may be explained
in terms of the perturbations by the applied field of a shell of
water molecules surrounding the ion at a mean distance of
   /
8150
the dielectric constant of free and bound water at microwave frequencies
an attempt is made to assess and summarize results obtained by
the authors and by other workers on the dielectric dispersion of
water the water molecules in the temperature range from to water
in hygroscopic salts aqueous gels and thixotropic gels  estimation
of hydration is also considered  references
   /
8151
the theory of the reflectivity of metals  the reflectivity of an
ideal metal for infrared radiation is calculated by a quantum mechanics
method  results agree with those obtained by dingle of using classical
methods the diffuse reflection wave functions correspond more closely
than the specular reflection wave functions to the actual electronic
wave functions as indicated by experimental results
   /
8152
skin and spiralling effect in stranded conductors  discussion  an
analysis is made to determine the ac resistance and internal reactance
of stranded conductors with or without a magnetic core at power frequencies
assuming current density constant in individual strands  the
spiralling of strands tends to reduce skin effect  data calculated
for standard copper conductors with parallel and spiralled strands
are listed
   /
8153
theory of breakdown of inhomogeneous dielectrics
   /
8154
formative time lag studies with high frequency discharges  pulse
techniques were used to study phenomena in coaxial cylinder and parallel
wire systems in the frequency range where the discharge changes from
corona type to one which completely crosses the gap  the breakdown
voltage drops about above the critical frequency
   /
8155
space charge effects in a high frequency discharge part  further
discussion of results of experiments previously reported of  cathode
disintegration phenomena various shapes of characteristic and factors
affecting the direction and magnitude of the emf are considered
   /
8156
field emission and surface phenomena  brief report of a symposium
held at pittsburg in november
   /
8157
delayed electron emission from metals  measurements were made on
a w foil substituted for the usual photocathode in a multiplier cell
emission was excited by bombarding with electrons and measurements
were started min after the bombardment the foil being simultaneously
heated at a controlled rate  the emission temperature curve passed
through a maximum between and  emission was eliminated by prolonged
heating at but was restored by exposing the foil to the atmosphere
at and abrading it  the results support theory advanced by nassenstein
of january
   /
8158
electron emission from metal surfaces after mechanical working  measurements
were made on various metals in gas at a pressure of about torr
using an electron multiplier  the surfaces were abraded with a steel
brush within the vessel  emission time curves are shown for pb ca
al and na the activity of the elements is correlated with their position
in the periodic system  oxidation may be the cause of the emission
but no explanation of the mechanism is yet available
   /
8159
on the escape mechanism of secondary electrons from insulators  starting
from the boltzmann transport equation and with certain simplifying
assumptions theory is developed which takes into account the interaction
of secondary electrons with lattice vibrations traps and occupied
donor levels  at high trap densities the secondary yield for high
primary energies is inversely proportional to the square root of
the trap density at low trap densities yield is independent of trap
density  expressions for the temperature effect for high primary
energies are derived for polar and nonpolar insulators  results for
the first case have been confirmed by experiment
   /
8160
antiferromagnetism  the nature of the spin coupling in the antiferromagnetic
oxide mno is discussed on the basis of a simplified mode  the
coupling between magnetic ions whose charge densities interact i
with an intervening nonmagnetic ion but not directly with each other
is described as the result of the polarization of the nonmagnetic
ion
   /
8161
representation of electromagnetic field by retarded potentials  applications
considered include a boundary problem and the equation of motion
of electron gas in vacuo
   /
8162
electromagnetic and acoustic scattering by a semi infinite body of
revolution  theory developed by kline of is used to determine the
scattering of a plane wave incident along the axis of a perfectly
reflecting body  for the case of a paraboloid the solution of the
em problem is obtained exactly in closed form  the results are compared
with those obtained from consideration of current distribution as
in below
   /
8163
electromagnetic and acoustical scattering from a semi infinite cone
calculations of scattering cross section for em waves incident along
the axis of the cone are made by the physical optics method based
on current distribution and by the f exact method based on the appropriate
field equations the solutions are practically identical for cone
semi angles close to zero or  the corresponding comparison is also
made for acoustic waves
   /
8164
studies of the diffraction of electromagnetic waves by circular apertures
and complementary obstacles the near zone field  measurements
have been made of both magnetic and electric field strengths with
diffracting apertures of diameter up to and normally incident waves
experimental techniques for illuminating the aperture and probing
the field are described wave lengths around cm afford a satisfactory
compromise between reasonable overall dimensions on the one hand
and reliability of measurements on the other  results are shown graphically
the predicted uniformity of the tangential magnetic field in
the aperture plane is confirmed
   /
8165
nonlinear theory of space charge wave in moving interacting electron
beams with application to solar radio noise  consideration of the
exact equations for interaction between two neutralized electron
beams indicates that steady state space charge waves can be propagated
in such a medium  the period of the wave depends on the amplitude
and phase velocity  the oscillation is simple harmonic for small
amplitudes but deviates progressively from this condition as the
amplitude increases  beyond a critical amplitude whose value depends
on the phase velocity the oscillation waveform becomes discontinuous
the theory is used to estimate the relative intensity of the second
harmonic component in solar rf outbursts reported by wild et al
analysis based on theory of radiation from oscillating plasma leads
to a value for the rf flux of the order of magnitude of that observed
   /
8166
electrodynamic averaged boundary conditions for wire mesh  equations
and are derived which form a system of boundary conditions relating
the averaged tangential components of the electric and magnetic fields
on the surface of the mesh to the e averaged surface density of the
current in the mesh  the results obtained are illustrated by calculating
the reflection of a plane wave from a plane uniform mesh and by determining
the screening effect of a spherical mesh with respect to a small
turn of wire carrying a current and located at the centre of the
sphere
   /
8167
the refractive index of water and aqueous solutions of sodium sulphate
at metre wavelengths  using the first method of drude the determination
of the dependence of the refractive index of water on wavelength
and temperature was extended to metre wavelengths and a temperature
range from to  similar investigations were also carried out to determine
the dependence on concentration of the refractive index of s aqueous
solutions of  the main conclusions reached are the refractive in
both cases increases linearly with temperature there is no anomalous
dispersion at metre wavelengths for a given temperature the refractive
index of a solution increases with concentration
   /
8168
application of molecular beams to radio spectroscopic study of rotation
spectra of molecules  molecular beams may be used to obtain narrow
spectral lines of width about and the rotation spectra of materials
in the solid state  quantitative estimates are made of the possibility
of detecting the rotation transition in molecules at a frequency
of using a spectroscope with a waveguide absorption cell and of the
transition using a cavity resonator instrument see also of january
   /
8169
growth of thin films  an attempt is made to explain qualitatively
the mechanism of growth on the basis of frenkels theory of absorption
a summary is given of the most important parameters which may affect
the structure of the film before during and after deposition
   /
8170
investigation of the natural frequencies and natural oscillations
of imperfect crystal lattices
   /
8171
electromagnetics  a treatment of maxwells theory and some of its
applications suitable as a reference book for research workers  mathematical
functions entering into the solution of wave equations are
dealt with in an appendix
   /
8172
microwave spectroscopy  includes chapters on spectroscope technique
and design on measurements on gases liquids and solids on nuclear
properties on molecular structure and on further possible applications
of microwaves
   /
8173
the diffusion of ionized meteor trails in the upper atmosphere  the
variation with height of the duration of radio echoes from meteor
trails is discussed  for the experimental conditions involved echo
duration decreases approximately exponentially with increased height
in agreement with diffusion theory  the diffusion coefficient is
between and in agreement with estimates based on rocket determinations
of upper air density
   /
8174
collision processes in meteor trails  momentum loss cross sections
for impacts between meteor atoms and atmospheric molecules are calculated
the values of the ionization cross section derived from them
are in agreement with those derived earlier by bates and massey the
diffusion of ionization in a meteor trail is also discussed in relation
to known mobilities of positive ions in gases
   /
8175
nonlinear theory of space charge wave in moving interacting electron
beams with application to solar radio noise
   /
8176
character of solar noise observation equipment installed at hiraiso
radio wave observatory  principles of measurement and accuracy of
equipment installed in march are discussed  routine observations
started in august  the path of the sun is followed by a beam aerial
system rotated every eight minutes with manual adjustment daily for
change of declination  during one minute in every eight the receiver
input is connected to a noise generator for calibration purposes
the double superheterodyne receiver has a bandwidth of about kcs
results are compared with data from other stations
   /
8177
solar electrodynamics  the reduction in conductivity of an ionized
gas by a magnetic field and the effect of a polarization electric
field are discussed  the theory has a bearing on conditions in the
solar atmosphere above sunspots and on tidal oscillations in the
ionosphere
   /
8178
geophysical aspects of solar flares  report of a discussion held
at the royal astronomical society in november  results of research
on the geomagnetic and ionospheric effects of the flares were surveyed
   /
8179
the irregular structure of the outer regions of the solar corona
records obtained in of the radiation from the radio star in taurus
of machin and smith and results of measurements made in june using
aerials of greater directivity cannot be explained in terms of absorption
or large scale refraction effects in the solar corona or large
scale refraction effects in the solar corona but are consistent with
a scattering theory  an estimate is made of the size and the electron
density of the coronal irregularities in the range of distance where
is the solar radius  the irregular structure may represent an extension
of the visible coronal rays
   /
8180
recent progress in the theory of the main geomagnetic field
   /
8181
particularly large chromospheric eruptions and geomagnetic activity
further analysis of observations indicates that geomagnetic activity
related to the appearance of certain eruptions can be distinguished
from that related to the central meridional passage of certain sunspots
of july
   /
8182
ion production rate in an atmosphere of exponentially rising temperature
with height  an expression is derived for the height distribution
of the ion production rate assuming that temperature varies exponentially
with height and also depends on the solar zenith distance  results
are similar to those of chapman for heights up to about  in the f
region the maximum rate of ion production and the height at which
it occurs vary anomalously with solar zenith distance
   /
8183
mechanisms of creation of i  nospheric inhomogeneities  results of
approximate calculations indicate that a negative temperature gradient
of about deg cm or greater at a height of about could result in thermal
convection current such as would produce inhomogeneities and high
velocity winds in the ionosphere  the temperature at km is assumed
to be about
   /
8184
studies on the sunrise effect in regions e and f  to be effective
in causing ionization in a night time layer solar radiation must
pass above the day time height of the layer  the observed delay in
time of sunrise effect is due therefore to the difference between
the night time and day time heights of the layer considered  observations
made at calcutta over the period are in reasonable agreement with
the theory
   /
8185
absence of bifurcation in the e layer  results of rocket measurements
of electron concentration see eg of april seddon et al are adduced
as evidence of absence of the bifurcation reported by lien et al
   /
8186
further remarks on bifurcation in the e layer
   /
8187
horizontal movements of ionization in the equatorial f region  results
of measurements at singapore during the period september april show
the existence of a regular semidiurnal sinusoidal variation in the
ew velocity component at the equinoxes  around the december solstice
during the mornings the movements were irregular  no correlation
with virtual height was found nor any regular ns movement
   /
8188
origin of the f layer  the splitting of the f layer into the f and
f layers is considered to be be due to a thermal effect  the maximum
temperature occurs in the region of maximum ion production but since
the density of gas in this region is a minimum higher electron concentrations
will occur above and below it  the region of maximum ionization
lies in the lower half of the f layer and hence the f layer will
be thinner than the f layer  the formula derived for the height distribution
of the electron concentration shows that the thermal process
could lead to splitting of an ionized layer and also explains the
secondary nocturnal maximum of the peculiarities of the equatorial
layer described by osborne are briefly discussed
   /
8189
nomenclature and conventions used in analysis of ionospheric data
it is proposed to classify the layers according to their thickness
a critical thickness is introduced to define the difference between
normal layers which are always thick and abnormal thin layers caused
by transitory phenomena  the term critical frequency may be used
of thin layers if account is taken of the intensity of the echoes
characteristics directly determined and those found by extrapolation
should be distinguished  revised lists of characteristic symbols
and code letters are given in appendices
   /
8190
relations between the critical frequency of the ionosphere f layer
at freiburg and solar activity centres during the years  analysis
is made separately for night time and day time observations  no significant
variation of f layer critical frequency was associated with
the passage of those sunspots giving no rf radiation  on passage
of sunspots giving rf radiation the night time critical frequency
suffered a significant reduction while the day time value was not
significantly affected  this night time effect is in concordance
with observations of ionospheric absorption reported by davies and
hagg of june
   /
8191
ionospheric behaviour at khartoum during the eclipse of february
observations indicate that the e and f layers behave as chapman layers
having constant effective recombination coefficients of and respectively
assuming a nonuniform distribution of the sources of ionizing radiation
on the suns disk  the positions and relative intensities of these
sources and the frequency of the radiation are indicated  the f layer
records suggest the existence at the time of the eclipse of two component
layers a lower one corresponding to the normal post sunrise f
layer having a high and an upper one which is a later development
of the lower having a low  changes in d layer absorption confirm
the asymmetrical distribution of sources of ionizing radiation  there
is no evidence of an eclipse effect on e ionization nor for a corpuscular
eclipse in the f layer
   /
8192
an apparatus for recording time delays between radio fading characteristics
the equipment is designed for the study of ionospheric winds
of and records time delays in the range with an instrumental accuracy
of about
   /
8193
sporadic e propagation
   /
8194
dsir ionospheric absorption measuring equipment  main design features
are described of pulse transmitting and receiving equipment used
at slough since  highly stable operation is essential  pulse duration
is variable between and the frequency range is and a peak power output
of is adequate for observer reception  phombic delta and folded dipole
transmitting aerials have been used  the receiver is a superheterodyne
with extra higigh gain and dynamic range and with provision for attenuation
varying continuously up to about db  double doublet and folded
dipole receiving aee been used  the display unit is a conventional
cro
   /
8195
collisional deactivation and the night airglow  a possible reaction
of the oxygen is indicated to explain the observed spectrum of the
night airglow
   /
8196
the earths exterior atmosphere and the counter glow the counter glow
as related to modern geophysical theories with seven recent russian
papers  collected and translated by er hope  theory based on observations
suggests that a gaseous tail resembling that of a comet stretches
away from the earth in the direction away from the sun  a valuable
contribution to the literature of upper atmosphere research
   /
8197
asymmetrical servomechanisms  servomechanisms in which the nonlinear
element has an input output characteristic asymmetric with respect
to the origin are considered  even if the input signal is a pure
sine wave the output will have a dc component that cannot be filtered
out by the linear element  the general feedback loop equations are
reformulated and the new conditions of stability considered  a temperature
control device is treated a as an example
   /
8198
feedback control systems  the following papers are included quick
methods for evaluating the closed loop poles of feedback control
systems discussion  correlation between frequency and transient responses
of feedback control systems p  coulomb friction in feedback control
systems discussion  describing function method of servomechanism
analysis applied to most commonly encountered nonlinearities  optimization
of nonlinear feedbacks  a relative damping criterion for linear
systems  errors in relay servo systems discussion  effects of friction
in an optimum relay servomechanism  backlash in a velocity lag servomechanism
determination of the maximum modulus or of the specified
gain of a servomechanism by complex variable differentiation  abstracts
of others papers appear separately
   /
8199
some saturation phenomena in servo mechanisms with emphasis on the
tachometer stabilized system  analytical methods of dealing with
frequency response and transient response are described and various
saturation effects are explained
   /
8200
relative stability of closed loop systems  the equivalence of a transfer
function plot and a plot of the laplace transform of transient response
is illustrated and the application of transform plots in the analysis
of linear systems is described
   /
8201
a differential analyzer study of certain nonlinearly damped servomechanisms
advantages of the system described by lewis of over corresponding
linear systems are illustrated and modifications to improve its operation
are suggested
   /
8202
limiting in feedback control systems  study of the effect of limiting
on system performance in terms of the frequency response
   /
8203
open loop frequency response method for nonlinear r servomechanisms
a graphical representation similar to a nyquist diagram is developed
for indicating frequency response characteristics and for the synthesis
of linear filters
   /
8204
the synthesis of optimum transient response criteria and standard
forms  eight mathematical criteria for optimum transient responses
are critically examined and the clear superiority of the minimum
integral of time multiplied absolute value of error is demonstrated
the application of this criterion results in the selection of standard
forms which are presented in tables  see also of january
   /
8205
approximation of transient response from frequency response data
a relatively short method is described involving an point graphical
integration which gives accurate results for linear feedback systems
with a closed loop transfer function of fifth order or below
   /
8206
bibliography on feedback control  a s classified list of references
up to relating to the theory and application of feedback systems
a list of relevant periodicals is also given
   /
8207
control of metal build up in minimum pressure sensitive contact systems
a review of designs aimed at reducing spire type metal transfer on
contacts with gaps of and operating on pressures down to
   /
8208
highly regulated rf voltage supply  a rf output voltage of rms maximum
with low harmonic content is obtained by using a crystal controlled
pentode oscillator at the fundamental frequency with positive feedback
regulation of the output is achieved by means of a negative feedback
loop incorporating a high gain dc amplifier which supplies the oscillator
screen grid voltage
   /
8209
silicon power rectifiers for ac line operation  used as half wave
rectifiers with capacitor input filters typical alloy junction units
rated for maximum rms input give output at  a typical full wave rectifier
with choke input filter will deliver ma at or at room temperature
heat dissipating mountings are discussed
   /
8210
rectifier filter characteristics  approximate calculations are described
for the design of half wave rectifiers with capacitor input filters
and of full wave rectifiers with capacitor choke input filters  the
method gives results within about of measured values
   /
8211
determination of frequency characteristics of automatic control systems
using mikhailovs curves  in russian
   /
8212
aircraft prot  ction  rom thunderstorm discharges to antennas
   /
8213
the effect of reactive components in the measurement of grounding
circuits  discussion of results of measurements of earth resistance
using ac in the range and
   /
8214
gating multipliers  analogue computing equipment on lines proposed
by goldberg of is described  economy of materials is achieved by
careful design of the switching circuit and by neutralization of
the parasitic capacitances of the valves  an accuracy to within one
part in at a mean gating frequency of i is obtained
   /
8215
a simplified method for the design of logical conversion matrices
diode matrix m networks are discussed  a numero graphical method
is explained for converting from one numbering system to another
possible applications for programming sequence control are suggested
   /
8216
an analog electronic correlator for acoustic measurements  the correlator
described is of the class operating directly on the input signals
ie using no carrier  the magnetic drum time delay system described
in of is used
   /
8217
photoelectric reader feeds business machines  ordinary print is scanned
by a photocell and the resulting signals are coded and recorded on
punched cards or tape for input to computers
   /
8218
magnetic recording applied to digital computers  the basic considerations
involved in the design of the magnetic storage drum used in the
cuba machine are discussed  optimum dimensions of pole faces for
recording and reproducing heads are calculated and design curves
are given
   /
8219
contact metals and relay contacts properties and comparative investigations
a detailed experimental investigation is reported of the relation
between contact resistance and the changes occurring at the contact
surfaces  current carrying current free and sparking contacts are
discussed  photographs are shown of contacts of various metals after
service
   /
8220
optimum shape coils  analysis is presented for designing a coil to
produce a required field at the centre of a cylinder with a minimum
expenditure of power
   /
8221
calculation of magnetic field strength in cylindrical coils  expressions
are derived for the axial component of the magnetic field using the
fact that the field strength at a given point is proportional to
the difference of the solid angles subtended by the end faces of
the coil  the expression for the solid angles is obtained in the
form of a difference of two double series  this can easily be evaluated
approximately  tables and graphs are given together with numerical
examples illustrating the method  the case of a multilayer coil is
included
   /
8222
parallel ferroresonant feedback type trigger circuit consisting of
an ac winding on a ferromagnetic core shunted by a capacitance with
auxiliary windings for excitation and polarization may be adjusted
to present two and in certain conditions three stable states  curves
are given showing the influence of the various parameters
   /
8223
a design method for direct coupled flip flops  design procedure is
described securing independence of valve characteristics and achieving
stability with resistors and supply voltages which may vary by given
percentages from the nominal values  switching speed for given stability
is a function of the supply voltages
   /
8224
reversible dekatron counters  bidirectional coupling in multistage
counters is achieved without the use of gating circuits by providing
the dekatrons with separate terminals for the two transfer electrodes
between the ninth and zero cathodes
   /
8225
the charging and discharging of nonlinear capacitors  correction
to paper abstracted in of
   /
8226
bounds existing on the time and frequency responses of various types
of networks
   /
8227
tensor analysis and linear network theory
   /
8228
transducer design for ultrasonic delay lines  the suitability of
quartz and transducers is considered for use in conjunction with
and bonds between transducer and delay medium to widen the pass band
a relative bandwidth of can theoretically be obtained using a transducer
composed of with and with a bond to a fused silica delay line  using
quartz transducers a relative bandwidth of was obtained experimentally
with a plastic bond and of with a solder bond  theory based on equivalent
circuits is given
   /
8229
the ultra bandwidth finline coupler  the finline coupler is a recently
developed microwave circuit element with which it has been possible
to assemble hybrid junctions directional couplers and polarization
selective couplers capable of operating over bandwidths of at least
three to one in frequency  constructional details and experimental
d results are given
   /
8230
effect of surface roughness on losses in microwave resonant cavities
measurements of value were made on a cylindrical mode cavity specially
designed so that the internal surface could be treated in various
ways eg by plating or polishing  the magnitude of the discrepancies
between the measured values and those calculated for a perfectly
smooth surface depends on the dimensions of the surface irregularities
and is very small when the surface unevenness is no greater than
the skin depth
   /
8231
the excitation of circular polarization in microwave cavities  a
matrix method is used to study the effect of transition pieces and
differential phase shifters on waves propagating in guides with two
degenerate orthogonal modes  three different methods are discussed
for generating circularly polarized waves in a cavity coupled to
the side wall of a guide the preferred arrangement uses a square
guide with incident wave polarized along one transverse diagonal
and reflected wave polarized z along the other and a circular coupling
window centred in the width of one wall at an appropriate distance
from the reflecting end
   /
8232
an approximate graphical analytical method for plotting the frequency
characteristics of a linear system from its transient characteristic
the method proposed is based on the approximation of the area under
the given curve by a sum of triangles  it is of importance in the
design of automatic regulation systems
   /
8233
transient response calculation approximate method for minimum phase
shift networks  the well known method of linear segments for the
calculation of zero pole locations of the transfer function corresponding
to a given attenuation characteristic is extended by allowing
the zeros and the poles to assume complex instead of only real values
   /
8234
matrix algebra  as a sequel to the quaripole theory presented by
cutteridge of special procedures and applications involving the general
parameter matrix of passive quadripoles with bilateral circuit elements
are discussed
   /
8235
electrolyte tank for solving network problems
   /
8236
synthesis of a network for a prescribed time function  the moment
generating function method and the time series method are discussed
they yield physically realizable networks under general conditions
three particular types of response are considered as illustrations
   /
8237
design of low pass ladder networks to work between unequal resistances
discussion of conversion data to enable formulae established in an
earlier pp paper of to be used ror cases of unequal terminating resistances
curves are presented relating the ratio of input and output
branch resistances to the ratio of input and output decrement for
up to five branches  see also of february
   /
8238
band pass filters using strip line techniques  practical details
are given of materials and dimensions for uhf filters and for matching
them to coaxial lines  typical units have mid band insertion loss
with attenuation at off mid band frequency
   /
8239
tchebycheff type band pass filters with arbitrary number of circuits
extension of the method developed by dishal of  undercoupled as well
as critically and overcoupled circuits are dealt with
   /
8240
coaxial resonator filters  from an analysis of an equivalent band
pass circuit an expression is derived for insertion loss in terms
of the loaded and unloaded q factors and the electrical design parameters
are related to the dimensions of the coupling loops  the insertion
loss characteristic of n identical resonators in tandem is determined
by considering shunt susceptances equally spaced along a transmission
line  an alignment procedure and arrangements for frequency multiplexing
are described
   /
8241
microstrip applied to band pass microwave filters  impedance measurements
are made by connecting the microstrip line through a network to
a waveguide or a coaxial slotted line  characteristics deduced are
phase velocity is constant over a wide range of frequencies wavelength
in microstrip is greater than the value corresponding to a transverse
em mode between infinite parallel plates approaching this value asymptotically
for very wide strips the dominant mode propagated is not
a pure transverse em mode the characteristic impedance of a microstrip
line is approximately equal to the reciprocal of the product of capacitance
per unit length and phase velocity  the design of resonant sections
by placing obstacles such as posts at proper distances is discussed
in detail
   /
8242
theory of noisy quadripoles  analysis is based on equivalent circuits
in which the original quadripole is depicted as noise free all noise
sources being transferred to a separate noise quadripole connected
in front of it  the noise figure is found from the equivalent noise
resistance the equivalent noise conductance and a complex correlation
admittance  methods for the experimental determination of the elements
of the noise quadripole are outlined
   /
8243
on asynchronous action  an analysis is made of quenching and excitation
of oscillations by an external oscillation of unrelated frequency
the excitation depends only on the transfer of the position of equilibrium
across the bifurcation point in the stability diagram and is
hence observed only in hard systems whereas quenching can occur in
hard and in soft systems
   /
8244
cathode follower coupled phase shift oscillator
   /
8245
a graphical sinusoidal analysis of a nonlinear rc phase shift feedback
circuit  frequency response curves are discussed of af oscillator
circuits including nonlinear eg thyrite resistors in the feedback
loop over a part of the frequency range the voltage function is triple
valued  the method used involves the graphical superposition of the
voltage resistance characteristic of the nonlinear resistor on that
of the parallel circuit
   /
8246
the realization of a given transfer coefficient feedback amplifier
systems  the design of feedback amplifiers using rc networks is discussed
in general terms and in relation to analogue computers low frequency
filters servomechanisms etc
   /
8247
harmonic distortion in sinusoidal frequency modulation  case of an
amplifier stage comprising pentode valve and tuned transformer  formulae
are presented for calculating the harmonics and the total distortion
present in the demodulated voltage  numerical calculations are performed
for five different sets of values of two important circuit parameters
   /
8248
electrical integration methods  following brief theoretical discussions
of the rc miller and wiegand hansen of integrators a new quasi exact
integrator circuit is described and both an approximate and an exact
theory are given  the errors inherent in the various methods are
discussed and graphs for their estimation are given
   /
8249
design of choke magnetic amplifiers with complex load  the design
of transductors is considered from the practical point of view  the
characteristic curves of four core materials of russian origin are
given  to illustrate the method the design of a transductor with
an amplification factor of working into a load is worked out in full
   /
8250
an amplifier based on the hall effect  the dc or ac signal is fed
to a suitably matched coil wound on a laminated magnetic core having
a narrow gap into which is inserted a thin rectangular slice of single
crystal insb  dc is passed through the slice and the hall emf is
picked up and applied to a matched load  high values of power gain
are theoretically possible  an upper frequency limit is set by core
losses  for comment by hm barlow and authors reply june
   /
8251
feedback stabilized transistor amplifier  loading of the feedback
network is avoided by the use of an emitter coupled differential
amplifier in the first stage  a three stage amplifier using ge transistors
gives an overall gain of independent of the transistors used
si junction transistors give more stable operation at high ambient
temperatures  circuits and component values for typical amplifiers
are given
   /
8252
cubic distortions in ring modulators  translations of paper abstracted
in of
   /
8253
an electronic phase shift tube for microwave frequencies  the transmission
of microwave radiation through an electron gas supported by a
gas discharge plasma situated in a waveguide structure is discussed
for the case in which the electron collision frequency is much less
than the microwave frequency and an expression is derived for the
phase shift arising from the change in guide wavelength  a gas discharge
phase shift tube has been developed on this principle and efficient
action obtained by using the negative glow region of the discharge
the performance of the tube is discussed in detail
   /
8254
electrical fluctuations and thermal radiation  text of a lecture
giving a broad nonmathematical review of theoretical work on thermal
fluctuations noise with particular reference to the uhf region
   /
8255
fundamental electromagnetic quantities  anomalies involved in the
generally accepted dual system of electric and magnetic quantities
are discussed  a threefold system comprising magnetism conduction
electricity and dielectric electricity is proposed as an improved
basis
   /
8256
study of some problems of electrostatics  elementary electrostatic
phenomena are deduced from the simple electronic theory of metals
the phenomena of conduction in homogeneous metals and from metal
to metal contact potentials and the peltier effect are examined
the treatment is essentially nonmathematical
   /
8257
survey of researches in physics in hungary part  short surveys by
different authors are given on several subjects including research
on ferromagnetics magnetic moments of atomic nuclei and the force
on polarized media
   /
8258
extension of frohlichs general theory of the static dielectric constant
to dielectrically anisotropic materials
   /
8259
applications of the piezoelectric equations of state  application
of the general linear piezoelectric equations of state of to plates
and thin bars  particular stress and strain systems are considered
a uniform notation is introduced for the elastic and piezoelectric
constants used  the relation between dielectric constant at constant
stress and at constant strain is investigated  electromechanical
coupling factor is discussed
   /
8260
the resistance of an elliptic plate  formulae for the resistance
are derived in the form of infinite series capable of numerical evaluation
to any degree of approximation for two different electrode arrangements
   /
8261
dependence of the electric strengths of liquids on electrode spacing
measurements have been made on hexane heptane and tetradecane using
electrode spacings of  the electric strengths are found to vary inversely
with the logarithm of the separation as predicted by theory
   /
8262
constriction of the positive column of a glow discharge at high pressure
   /
8263
the growth of electrodeless discharges in hydrogen
   /
8264
electrical breakdown at very low gas pressures  a discussion in terms
of atomic collision data of problems involved in the interpretation
of an observed anomaly in the variation of breakdown strength with
pressure and in the estimation of the pressure at which breakdown
would occur if it were due solely to ionizing collisions in the body
of the gas
   /
8265
studies of externally heated hot cathode arcs  part plasma density
distributions in the anode glow mode  analysis of the plasma density
distributions indicates that the anode glow mode can exist only if
the emission capacity of the cathode is at least twice as great as
the anode current  this is supported by experimental evidence  part
   /
8266
experimental investigations on electron interaction  certain observations
in low pressure gas discharges and in magnetrons suggest an electron
interaction effect several orders of magnitude in excess of the theoretical
values based on binary encounters only  the validity of the
theory was tested by experiments in which a carefully colimated electron
beam was shot through a charge cloud the scattering of the beam being
directly observed  both plasmas in thermal equilibrium and pure electronic
space charges were investigated  in both cases the degree of
scattering observed is less than five times the value predicted by
theories neglecting simultaneous multiple collisions hence the latter
cannot account for the observed anomalies
   /
8267
on the measurement of the average time delay in secondary emission
the time delay of the secondary emission is measured by comparing
the duration of short bursts of primary emission with the duration
of the corresponding bursts of secondary emission  the primary bursts
are produced by deflecting a beam across an aperture at high speed
while the secondary beam is scanned over eg a fluorescent screen
the duration of the secondary pulses is longer than that of the primaries
by an amount which depends on the accelerating voltage
   /
8268
fundamental wave functions in an unbounded magneto hydrodynamic field
   /
8269
particle transport electric currents and pressure balance in a magnetically
immobilized plasma  an analysis of a plasma immobilized by a
magnetic field shows that each kind of charged particle has a general
drift perpendicular to the gradient of the field but that there is
no corresponding electric current density  there is an exact cancellation
arising from the gradient of the larmor radius  the current density
which is present arises exclusively from the particle density gradient
and is not associated with any drift of matter
   /
8270
antiferromagnetism  a survey of theoretical and experimental aspects
the spin wave approximation is useful especially for lattices of
higher dimensions and for larger magnitudes of spin  this method
can be easily generalized eg so as to take second neighbour interactions
and dipole forces into account  great mathematical difficulties are
involved in the refinement of the theory to apply to higher temperatures
and the calculation of higher order quantities such as the fluctuations
or the short range order  over references  see also of
   /
8271
statistical models of ferrimagnetism  a theoretical discussion of
the properties of some idealized ferrimagnetic crystals the lattice
being considered divided into two sublattices
   /
8272
a short modern review of fundamental electro magnetic theory  further
discussion on of january
   /
8273
diffraction of electromagnetic waves by a metallic wedge of acute
dihedral angle  an investigation is made of the field produced by
reflections within the space included between two plane condductors
set at an angle  experimental and theoretical results are given for
angles of and  discussion indicates that the field pattern for angles
which are integral fractions of can be computed on the basis of geometrical
optics
   /
8274
the diffraction of a non monochromatic electromagnetic wave by a
slit and a grating  a general solution is derived from kirchhoffs
solution  results of calculations and measurements are in good agreement
over the range in which kirchhoffs solution is applicable
   /
8275
elliptically and circularly polarized electromagnetic waves  a general
discussion of the subject and its applications in radar technique
with extensive bibliography  see also of august
   /
8276
absorption of cm microwaves in some aromatic and aliphatic compounds
in the liquid state
   /
8277
microwave spectroscopy of gases  recent developments in the field
are outlined measurements have been made at wavelengths down to
about
   /
8278
distribution of radio brightness across the andromeda nebula  measurements
made with the helix aerial and improved receiver at the ob ohio
state university are reported the frequency used was
   /
8279
evidence of limb brightening of the sun at cm wavelength
   /
8280
the sun in two dimensions at cm
   /
8281
distribution of radio frequency brightness across the solar disk
at a wavelength of cm  results of three investigations see also and
above indicate appreciable limb brightening contrary to results reported
by stanier of  there has been a marked change of brightness during
the sunspot cycle  the radial extent of the distribution is greater
at the equator than at the poles
   /
8282
magnetic field of the sun  the principles of operation of babcocks
zeeman effect solar magnetograph are described and some experimental
results obtained are shown in the form of magnetograms  the general
magnetic field strength is oersted of polarity opposite to that of
the earth  large local bipolar and unipolar fields have been observed
and are shown in several of the magnetograms  the field distribution
varies from day to day and fluctuations of the order of oersted are
believed to occur in local fields with periods of about min  the
unipolar fields are probably the sources of corpuscular emission
which produce geomagnetic storms with a day recurrence period
   /
8283
some observations in bratislava during the solar eclipse on june
relative measurements were made of the total radiation fig  radiation
in the red yellow and ultraviolet bands the air temperature detected
intensity of broadcast transmissions from bratislava and the level
of cosmic radiation  the maximum in fig occurred about min before
the minima in figs and
   /
8284
scientific programme of the international geophysical year  an outline
is given of comprehensive investigations planned in various branches
of geophysics and allied subjects including geomagnetism the aurora
airglow solar activity and ionospheric phenomena
   /
8285
theories of the earths magnetism
   /
8286
a semi annual periodicity in the beginnings of recurrent magnetic
storm series
   /
8287
a note on the world wide distribution of the sporadic e ionisation
a discussion based on data obtained during from ionospheric sounding
stations of them in n america  in geomagnetic mid latitudes the prevalence
of e clouds is greatest in local summer daytime  in the northern
auroral and the equatorial zones no seasonal variation is apparent
in the auroral zone there is a daytime belt of intense e ionization
and in the equatorial zone one at night time  these belts have different
characteristics and appear to have different causes  very marked
variation with longitude has been noted
   /
8288
a particular feature of the f layer at lwiro central africa  observations
over the period january may indicate that at the equinoxes the
f layer rapidly drops sometimes to below km towards midnight by an
apparent contraction following an equally rapid expansion often coinciding
with the of measurable thickness corresponding to a night time
e layer
   /
8289
on radio measurements at jabalpur during the solar eclipse of june
   /
8290
some geomagnetic effects in the equatorial f region  o observations
at ibadan nigeria during show that the midday minimum of the maximum
concentration of ionization exhibited on magnetically quiet days
disappears and is replaced by a maximum as the degree of magnetic
disturbance increases  the total ion content below the height of
maximum ionization varies similarly  perturbations due to magnetic
disturbance have both diurnal and semidiurnal components  difficulties
in the application of martyns theory of are discussed and certain
modifications are suggested
   /
8291
on a new method of determining the height of the nightglow  nightglow
observations taken at two wo stations separated by a distance comparable
with the height of the layer observed will show correlation over
a period if both stations observe the same point the height of the
point can hence be deduced  observations taken during two successive
nights give a height between and for the origin of the radiation
   /
8292
equipment for lightning research on monte san salvatore  the equipment
has been appreciably augmented since the previous report of
   /
8293
the significance of a nonterrestrial magnetic field in neutral stream
theories of the aurora  the hypothesis that a neutral stream of ions
travels from the sun with a velocity of in a magnetic field of strength
fits observed data on aurorae and magnetic storms
   /
8294
on the electric field theory of magnetic storms and aurorae  the
electric field theory is further developed  by taking into account
the inertia of the beam of ionized gas emitted by the sun the initial
as well as the main phase of storms can be accounted for  see also
below
   /
8295
model experiments on aurorae and magnetic storms  experiments on
a magnetized sphere of were performed to check alfvens theory above
although a proper scaling down is not possible some confirmation
of the theory was obtained in particular the space charge accumulated
in the discharge region discharges along the lines of magnetic force
photographs of the discharge patterns produced at various electric
and magnetic field strengths are shown and discussed
   /
8296
radio reflections from aurorae  part  observations made with a meteor
survey apparatus confirm the conclusions drawn previously of january
the mean velocity of the reflecting regions changes from westwards
at with diffuse echoes to eastwards with discrete echoes  there is
a diurnal minimum of echo frequency between and when the reflecting
regions appear to be at rest and echoes are absent from to ut  correlation
is observed between the radio echoes the occurrence of visual
aurorae and magnetic activity
   /
8297
time scale and gain influence on servo performance  the criterion
previously applied in determining normalized transfer function coefficients
of august can also usefully be applied in the selection of optimum
gain or time scale for second or third order servo mechanisms
   /
8298
the use of correlation techniques in the study of servomechanisms
   /
8299
the dynamic behaviour of servomechanisms using thyratrons  if the
response of the servomechanism is linear the self inductance of the
motor armature may be ignored in calculating the transfer constant
of the system for discontinuous operation in continuous operation
it must be taken into account  a method of calculating the transfer
function is presented for the general case of nonlinear operation
but the formulae involved are cumbersome and an experimental approach
may be preferable
   /
8300
the economics of the transistor dc transformer  hv supply units using
power junction transistors are compared with conventional hv sources
   /
8301
electrical properties of titanium dioxide rectifiers  results obtained
are similar to those reported earlier by breckenridge and hosler
of  the conversion efficiency of a bi tio rectifier remained constant
during operation for at and during most of the test at but decreased
rapidly during operation at failure occurring after  the spread of
the rectification characteristics of rectifiers is presented graphically
a well as the distribution of peak dynamic current voltage characteristics
in specimens
   /
8302
a precision direct current stabilizer  a dc stabilizer is described
which delivers stable to a few parts in  a degenerative feedback
system is used with a contact modulator amplifier self oscillation
being prevented and the frequency response improved by an auxiliary
ac feedback loop  facilities for monitoring the stability are provided
   /
8303
a voltage stabilizer for a radio frequency extra high tension set
the voltage to be stabilized is applied across a bank of resistors
and a fraction is balanced against a rf reference voltage the difference
being converted in a circuit comprising two valves type to a signal
which is amplified rectified in a phase sensitive circuit and applied
to control the screen voltage of the main oscillator  curves show
the variation with load current up to for nominal output voltages
of and kv
   /
8304
heavy duty high stability dc power supplies  series valve stabilizers
are considered as a simple step by step development of the cathode
follower  by shunting a resistor or barretter across the series valve
substantially constant loads of several amperes can be stabilized
to per cent  full circuits are given of two typical units providing
outputs of and watts with efficiencies of and per cent respectively
the latter includes a device providing audible warning when supply
voltage variations exceed the range stabilized automatically
   /
8305
the use of an electron velocity analyser to stabilize a direct voltage
source to a few parts in a million  a degenerative feedback stabilizer
circuit is used in which the signal to the feedback amplifier is
obtained by accelerating a beam of electrons by the voltage to be
stabilized and measuring the velocity by deflection in a fixed magnetic
field  much larger signals can be obtained in this way than by use
of the usual resistance type potential divider
   /
8306
electronic computers for the businessman  a survey covering commercially
available digital computers  important characteristics are tabulated
   /
8307
storage devices for high speed calculators  a survey covering thermal
optical sonic delay electrochemical cr tube ferroelectric capacitor
magnetic drum magnetostriction and magnetic core devices
   /
8308
a proposed modification to the csiro mark computer  the suggestion
is put forward that a facility be built into the machine for distinguishing
between machine commands and interpretive or hyper commands
so that the former are performed directly while on receipt of one
of the latter control is directed to the head of the interpretation
routine with simultaneous storage of the link datum to enable return
of control to the nedt programme command after performance of the
hyperfunction  this would result in a considerable gain in speed
see also and of
   /
8309
automatic square rooting  a computation method is described with
examples and an indication is given of the type of additional circuit
required in computers of the leo type of pinkerton et al  the square
root of a digit number is obtained in
   /
8310
multiple coincidence magnetic storage systems  in existing magnetic
matrix storage systems a given location is selected by applying to
two intersecting wires a current equivalent to one half of the selecting
field  this situation is generalized so that any core is selected
by energizing wires each with a current equivalent to of the selecting
field  the advantages gained are in the correspondingly smaller fields
applied to the nonselected cores or alternatively in the faster switching
times obtainable by applying a total field greater than the coercive
force to the selected core  specifically a storage matrix is illustrated
in which the cores are toroids etched from a continuous sheet of
magnetic material
   /
8311
a computer for solving some problems in connection with travelling
wave particle accelerators
   /
8312
digital computer plug in units and associated equipment  basic circuits
etched on small boards are plugged into standard contact receptacles
of which are combined in a sub rack assembly complete with power
wiring
   /
8313
the unit step the unit pulse and the dirac operator  the unit pulse
is identified as the derivative of the unit step and the identity
between the unit pulse and the dirac function is demonstrated by
considering the establishment of a direct current in a circuit with
finite inductance but vanishing capacitance
   /
8314
stamping metals by etching  the process briefly described consisted
of printing the pattern of the desired circuit or part on a flat
metal sheet or strip with an acid resistant ink and then etching
away the unprotected metal  the printing can be performed by a photographic
lithographic or silk screen process
   /
8315
resistors for radio interference suppression in otto cycle internal
combustion engines
   /
8316
directly coupled transistor circuits  switching circuits using surface
barrier and alloy junction transistors are described  in many cases
the only other circuit components required are resistors  rise and
fall times of about and respectively are obtained  applications in
digital computers are mentioned
   /
8317
further analysis of transmission line directional couplers  the conditions
for infinite directivity in transmission line directional couplers
derived by firestone of january are discussed more general conditions
are derived valid for any degree of coupling
   /
8318
frequency aging of high frequency plated crystal units  the aging
process is discussed in terms of contamination of the quartz crystal
the influence of various production methods is examined  data obtained
with units in metal and glass enclosures are presented graphically
   /
8319
the effect of temperature and acoustic impedance of vapours on the
electrical constants of quartz  measurements were made of the equivalent
resistance of a crystal vibrating in vapours of various organic
liquids  at a given temperature the equivalent resistance depends
on the pressure  as the temperature increases the equivalent resistance
decreases the rate of decrease depending on the particular vapour
   /
8320
tunable temperature compensated reference cavity  a design is discussed
based on separation of the tuning and temperature compensation functions
temperature compensation at fixed frequency is discussed first
and the conditions for variable frequency are then deduced  experiments
indicate that a cavity with a double nosed construction can be made
satisfying the theoretical requirements over a or band  analysis
is presented with reference to an equivalent circuit
   /
8321
active ladder network analysis  a computationally economical method
is developed in which the voltage appearing across the final rung
of the ladder is expressed as a function of the individual randomly
distributed sources of emf by a reduction process involving successive
applications of thevenins theorem to all the meshes  the method is
illustrated by examples
   /
8322
representation of the general linear four terminal network and some
of its properties  non reciprocal networks are considered  equations
are formulated in terms of power and impedance  a method of representation
is developed based on introduction f a circuit element called
the anti reciprocal transition in series with a reciprocal network
power attenuation and matching are investigated  a new criterion
for classifying networks as passive or active is proposed  a grounded
emitter transistor amplifier is discussed as a particular application
of the theory
   /
8323
the design of quadripoles  in the case of symmetrical quadripoles
by writing where and are the impedance parameters defined earlier
of general expressions are derived by a matrix treatment for the
current and voltage in a ladder network in which the characteristic
impedance term z occurs in the first degree
   /
8324
synthesis of passive quadripoles  it is shown that any passive a
quadripole can be constituted by combining a two terminal network
with a t or network the whole comprising four two terminal physically
realizable networks with complex impedance
   /
8325
a new method for investigating linear quadripoles  z a treatment
based on representation of impedance transformations by displacements
on the surface of a sphere known graphical methods are made accessible
to a purely geometric treatment by the method of projection  problems
of networks satisfying kirchhoffs laws can be solved with compasses
and ruler
   /
8326
impossible behaviour of nonlinear networks  the following proposition
is discussed an isothermal electromechanical system whose primary
resistors are quasi linear cannot convert direct current to alternating
current  a resistor is said to be quasi linear if the voltage drop
across it is a function only of the current and if the differential
resistance is positive
   /
8327
note on the kramers kronig relations  this explicit form of the relationship
between the real and imaginary parts of a physically realizable
network function is correlated with the alternate conventions available
for such problems  the transformation from a linear frequency scale
to a logarithmic one is simply effected by considering the mellin
transforms of the appropriate functions
   /
8328
some gyrator and impedance inverter circuits  the design of feedback
amplifiers to provide impedance inversion is considered  negative
impedance elements may be included to compensate for the residual
impedances in the inverter when this is done the circuit exhibits
gyrator properties  measurements on a high stability amplifier with
a series resistance of in the input lead indicated that accurate
impedance inversion was obtained for load resistances from to
   /
8329
nyquists and thevenins theorems generalized for nonreciprocal linear
networks  theory of nonreciprocal networks such as those including
ferrites is developed taking account of internal noise sources  the
system ca be treated as the combination of a source free network
together with a set of correlated noise current or noise voltage
generators  modifications of the treatment are indicated for dealing
with cases whee the actual noise sources are at different temperatures
as in the problem of determining the noise correlation between two
receiver channels connected to a gydetermination of the frequency
and phase characteristics of a network for a given at  enuation curve
a modification of the graphical method developed by baum of is described
for deriving a realizable attenuation characteristic approximating
to the given one
   /
8330
a derivation method for designing two and three element filter structures
a summary of fundamental principles with specific examples of
two and three element design using loss free elements with no mutual
inductance  the h n and associative derivations and an extension
of zobels m derivation are treated also the lc derivation involving
interchange of la and c  application of nortons transformation is
illustrated
   /
8331
the noise power bandwidths of iterated low pass rc filters  the noise
power bandwidths of n section low pass rc filters are calculated
exactly from the transfer function for n to  an asymptotic expression
is derived for the band width when the number of sections is large
and then the bandwidth is inversely proportional to n
   /
8332
the periodic solutions of a nonlinear differential equation of the
second order with unsymmetrical nonlinear damping and a forcing term
the differential equation considered gives a closer approximation
to the behaviour of valve oscillators than the van der pol equation
and demonstrates the frequency deviation associated with the presence
of higher harmonics
   /
8333
study of the relative frequency fluctuations of two reflex klystrons
stabilized by different methods  in connection with projected experiments
of the michelson type it was desired to ascertain whether a variation
of due to modulation could be detected in the frequency of oscillations
modulated at  a study was made of the inherent frequency fluctuations
of klystron oscillators and of methods for limiting them with particular
reference to the stabilization of supply sources  alternative electronic
methods involving use of waveguides and cavity resonators were used
to stabilize the frequency of the beat between the two klystron oscillations
one of which was modulated  filters of bandwidth were used
to improve this stability  results are compared with those of pound
of and essen they indicate that it should be possible with present
day techniques to detect a frequency variation of the order of in
   /
8334
phase stabilization of microwave oscillators  description of a circuit
incorporating a single stable feedback loop that has been used to
stabilize the frequency of a type band klystron by locking it to
a harmonic of a quartz controlled oscillator  any phase modulation
in the klystron is detected in a phase discriminator the resulting
signal is amplified in a differential dc amplifier and applied to
the klystron repeller electrode
   /
8335
phase fluctuations in a valve generator  the effect of shot noise
on an oscillator operating in the steady state is considered theoretically
the intensity and the statistical properties of the shot current
are independent of the feedback circuit and can thus be represented
by a separate noise current generator in parallel with the oscillator
analysis is presented on the basis of such an equivalent circuit
   /
8336
frequency stable lc oscillators  critical comment on of and authors
reply
   /
8337
analysis of the relaxation period of a multivibrator  the analysis
takes account of positive grid swing and appreciable shunting capacitance
comparison of values obtained from the theory with experimental
results indicates that the method is satisfactory
   /
8338
a semiconductor diode multivibrator  a circuit is described using
one double base diode see eg of together with one ordinary diode
and only three resistors and one capacitor
   /
8339
significance of the mandelstam condition in the oscillations of a
neon lamp  theory presented previously of is generalized  for relaxation
oscillations to occur three conditions must be satisfied simultaneously
including the mandelstam condition which requires that the energy
of the system shall remain constant at the discontinuity  this condition
can be satisfied using a rc circuit but not using a rl circuit
   /
8340
isocline diagrams for transistor circuits  the method described for
the graphical analysis of transistor negative resistance oscillators
is based on nonlinear mechanics and does not necessitate approximation
of curved transistor characteristics by straight lines  voltage and
current trajectories can be obtained by a simple construction which
also indicates the rate of change of the voltages and currents during
the course of cycllic or transient phenomena
   /
8341
nonsaturating pulse circuits using two junction transistors  junction
transistors are found to be fast enough for pulse applications if
the collector voltage is prevented from reaching zero  switching
times can be achieved with available types  the required limiting
action is effected by introducing diodes which terminate the switching
transients by their breakdown  a two transistor binary counter is
described
   /
8342
a decade frequency divider  a divider developed for use with a quartz
crystal clock consists basically of a chain of eccles jordan binary
pairs whose overall division ratio has been reduced by means of feedback
a complete circuit diagram is given
   /
8343
method of reducing zero f error and drift in breaker type dc amplifiers
thermal emfs in the input transformer are cancelled y by using a
double pole double throw input chopper and connecting a high quality
capacitor in series with the winding
   /
8344
low frequency decoupling of cathode and screen grid of an amplifier
valve  a method is described for using the smith chart to determine
the falling off at the upper and lower ends of the af response curve
due to the decoupling capacitors
   /
8345
distortion and power in aperiodic amplifiers using ideal screen grid
valves  calculations are made for class a ab b and c operation assuming
a parabolic or nearly parabolic vl valve characteristic  a determination
is made of the input waveform required to give a pure sinusoidal
output  the effect of negative feedback is studied  operation with
sawtooth or square pulses is discussed
   /
8346
the band pass distributed amplifier  general expressions are derived
for the gain of a distributed amplifier with any number of valves
coupled by identical filter sections  the analysis indicates that
reduction of band edge peaks is more difficult for band pass than
for low pass amplifiers  choice of suitable filter networks for the
band pass case is discussed and some experimental results are presented
for a valve amplifier with a pass band from to
   /
8347
design of wide band rc amplifiers  discussion of multistage amplifier
with inductive equalization in the anode circuit  the effect of negative
feedback in the cathode line is examined
   /
8348
active error feedback and its application to a specific driver circuit
feedback amplifiers are discussed in which the feedback signal is
nominally equal to the input the difference which is proportional
to the distortion or error in the output is amplified in s a separate
circuit and reinjected with the proper polarity to reduce the output
error  analysis is given for a cathode follower circuit incorporating
this principle the arrangement is especially suitable for driving
the grid of an output valve highly positive  experimental results
support the theory
   /
8349
the transistors part applications  amplifier oscillator and switching
circuits are discussed
   /
8350
linear properties of the transistor  formulae and charts for various
transistor circuits are presented
   /
8351
internal feedback and neutralization of transistor amplifiers
   /
8352
tensor analysis of transistor feedback circuits  theory is presented
for the grounded base circuit  the coefficients of the impedance
matrix for the back coupled circuit are obtained by multiplying those
for the original circuit by certain characteristic tensors derived
from the relation between the currents in the original and in the
back coupled arrangements  particular conditions examined include
current feedback positive and negative voltage feedback and other
arrangements involving two feedback paths applicability of the duality
principle is discussed
   /
8353
a linear capacitance change circuit  capacitance changes produced
by mechanical displacement modulate the frequency of a franklin oscillator
which drives a nonode fm discriminator  sensitivity is and the
output is linear between and about references are given to measurements
of mechanical and other quantities by means of a capacitance change
   /
8354
crystal diodes in voltage dividers in particular for increasing the
linearity and slope of static and dynamic characteristics  hf voltage
dividers are discussed comprising a diode in series with a passive
element the voltage division ratio being varied by suitably controlling
the diode  applications to reactance valve fm circuits are described
   /
8355
transistor audio amplifiers  only junction transistors are considered
   /
8356
sharpening of observational data in two dimensions  the problem considered
is that of recovering true distributions from smoothed observed
distributions this involves the solution of a linear integral equation
several methods of solving the equation are examined and a technique
for the application of polynomial solutions is presented  the effect
of random errors in the observational data is taken into account
wherever possible
   /
8357
representation of the modes of motion of an undamped linear oscillating
system with two degrees of freedom  the general solution of the differential
equations for a system comprising two coupled mas points corresponds
to the superposition of two natural oscillations but a better
idea of the phenomenon is obtained by considering the motion as a
single oscillation modulated in phase and in amplitude  this approach
is illustrated graphically
   /
8358
polarization effects on the brightness waves of electroluminescence
the observed cyclical variation of brightness of electroluminescent
systems excited by sinusoidal fields is shown to be related to polarization
effects of the type discussed eg by jaffe in connection with
semi conductors
   /
8359
theory of thermoluminescence
   /
8360
polarization of light by aspherical ferro magnet particles in a uniform
magnetic field part experimental investigation with smoke
   /
8361
calculation of the elementary electric charge from the energy quantum
model  by extending the theory developed previously of august and
back reference a value of esu is obtained for the elementary electric
charge this differs by from the established value for the electron
the difference being mostly due to the approximations used
   /
8362
nets composed of parts of circles for the approximate solution of
field problems
   /
8363
dielectric layer with spherical cavity in homogeneous electrostatic
field  the special case of a cavity with centre equidistant from
the two faces of the layer is considered mathematically a method
is indicated for solving the problem when the cavity is not centrally
placed
   /
8364
calculation of internal field in relaxation polarization in polycrystalline
dipole type dielectrics
   /
8365
skin resistance of a transmission line conductor of polygon cross
section  a theorem is presented according to which a conductor whose
cross section is a polygon that can be circumscribed on a circle
has the same skin resistance as a conductor of the same material
having the said circle as its cross section  see also of
   /
8366
calculation of the ac resistance of a solid conductor with rectangular
cross section  the joule effect losses are calculated starting from
maxwells equations ad making assumptions corresponding to those for
the case of a circular cross section  the results are compared with
those obtained by investigating penetration depth
   /
8367
statistical description of assemblies with collective interaction
parts  a critical review of literature on the subject is presented
two types of assemblies of electrons and ions are distinguished those
with a finite number of discrete beams with definite velocity and
those with thermally disordered motion with or without superimposed
beams  investigations of the first type of assembly lead to satisfactory
results the difficulties encountered in dealing with assemblies of
the second type are due to neglecting the limitations of the models
used  the model of the dispersed charge carrier assembly presented
by twiss of is then considered and the concepts of collision and
the collision zone are discussed
   /
8368
phenomenological theory of townsend breakdown in dielectrics
   /
8369
high frequency gas discharge plasma in hydrogen  the microwave field
strength required to maintain a hydrogen plasma in the steady state
is calculated from theory based on a solution of the boltzmann transport
equation  the results are in satisfactory agreement with measurements
made in a resonant cavity at different values of pressure and plasma
concentration
   /
8370
theory of high frequency discharge in gases at low pressures  calculation
of electron distribution function  the electron distribution is
obtained by resolving boltzmanns equation by a method of successive
approximations considering both elastic and inelastic collisions
the electron temperature corresponding to a maxwellian velocity distribution
is derived and the general form of evolution of electronic
density is given
   /
8371
role of positive ions in high voltage breakdown in vacuum
   /
8372
microwave and metre wave radiation from the positive column of a
gas discharge  radiation intensity measurements were made at and
on a ne discharge by inserting the ps positive column in a resonant
cavity and comparing the cavity output with that of a known noise
source  the rf power per unit bandwidth is expressed in terms of
where is boltzmanns constant and i the equivalent noise temperature
and is comparable with the temperature of the electrons in the discharge
the departure of from the value corresponding to a maxwell or
druyvesteyn electron velocity distribution is investigated
   /
8373
resonance type secondary electron multiplication  electron multiplication
by means of an hf field applied between a pair of parallel plates
with secondary electron emission rate greater than unity is considered
theoretically and a relation is derived between the hf amplitude
the length of field lines and the phase at impact required for avalanche
multiplication  expressions ar also obtained for the starting and
cut off voltages  calculated results are in good agreement with experimental
results  see also of
   /
8374
delayed electron emission in metals  continuation of earlier work
f of  results of experiments on w indicate that delayed emission
centres are imperfections in the lattice of the oxide surface film
these imperfections act as traps which can be emptied by heating
to about and destroyed by heating to
   /
8375
kinetic theory of weakly ionized homogeneous plasmas part  the second
order approximation to the electron velocity distribution function
relating to the energy exchanges between an applied electric field
and the plasma in a lorentz type gas is developed  the resulting
expression contains a divergent term corresponding to a nonstationary
state in which the electron gas continually heats up  the quality
factor q of the plasma is calculated  the derivation of certain formulae
used in part is given in an appendix
   /
8376
longitudinal plasma oscillations part  a theoretical investigation
is presented in which the effect of motion of ions is taken into
consideration
   /
8377
longitudinal plasma oscillations part  the equations derived in part
are applied to the investigation of the dispersive properties of
the plasma for the case of hf oscillations lf oscillations and high
electron drift velocities  results show that in the propagation of
longitudinal waves in discharge tubes the motion of ions is frequently
of importance  formulae are derived for the dependence of the space
periodicity and the damping coefficient on the discharge parameters
   /
8378
recombination between electrons and positive ions  a bibliography
of reference is critically examined  nearly always recombination
takes place by an interaction involving at least two atoms direct
recombination of an electron and a positive ion in a plasma involving
the radiation of excess energy is relatively rare
   /
8379
theory of apparatus for observation of nuclear magnetic resonance
   /
8380
a postulational approach to electromagnetism
   /
8381
interaction of moving charges with wave circuits  when a charge moves
along a nondispersive transmission line it induces forward and backward
wave components in the line  for unaccelerated motion there is no
radiation unless the charges moves with the speed of an unforced
wave  for small accelerations both radiation to the line and electro
magnetic inertial effects caused by changes in the energy of the
fields will be observed  the electro magnetic mass at velocities
greater than the wave velocity is negative  large accelerations can
be handled by numerical computation  in the case of dispersive circuits
the charge radiates at frequencies for which the phase velocity of
the circuit is equal to the velocity of the charge  this radiation
is identified with cherenkov radiation  similar radiation takes place
when a charge moves through a plasma
   /
8382
cerenkov radiation of electrons moving parallel to a dielectric boundary
analysis is based on an eigenfunction expansion of the em field
the process may be interpreted as an excitation of surface waves
   /
8383
relation between the intensity distributions over radiating systems
and their directivity characteristics  fourier transform analysis
is used to show that contrary to fischers result the directivity
characteristic of a linear or plane radiator of finite dimensions
is uniquely related to the amplitude distribution over the radiator
the theory is extended to the consideration of propagation media
with local inhomogeneities acting as secondary radiators and an investigation
is made of the relation between distribution of inhomogeneities
and the directivity characteristic of the scattered radiation
   /
8384
study of the electromagnetic field in the vicinity of a reflecting
surface  analysis is given for the general case of a plane incident
wave with elliptical polarization  if the reflecting surface is an
infinite plane the reflected wave is also plane modifications of
the reflected wave by other types of reflecting surface are mentioned
   /
8385
simultaneous partial absorption reflection and transmission of a
nonuniform plane wave by a thin metal film  the theory developed
for uniform waves of is extended to nonuniform waves such as those
propagated in waveguides  appropriately modified expressions for
th energy components are obtained by taking account of the guided
wave phase velocity  conditions with a set of parallel films are
discussed  a film of thickness such as to absorb of the incident energy
can be made totally absorbing by setting up standing waves at the
back surface
   /
8386
the interaction between an obliquely incident plane electromagnetic
wave and a electron beam part  the investigation reported is relevant
to the operation of mm wave generators and to phenomena occurring
in the solar corona  analysis is presented for magnetic field vector
and electric field vector of the incident wave perpendicular to the
electron beam the general solution for an arbitrarily polarized wave
is obtained as the sum of the two separate solutions  when the axial
phase velocity of the wave is equal to the beam velocity the beam
behaves like a metal reflector  coupling between different modes
in the scattered wave and in the wave inside the beam is taken into
account this coupling vanishes if the wave is incident normally or
if the beam is in vacuum  resonance occurs at certain values of beam
velocity
   /
8387
direct measurement of the ellipticity of the rf cotton effect by
the quarter wave method  measurements were made using a circular
waveguide of diameter with an aerial at one end connected to a klystron
and a rotatable probe at the other end  two copper pins of lengths
mm and mm respectively are fixed mm apart in an axial insulator rod
making angles of and respectively with the direction of the electric
field  the variation with wavelength of the plane of polarization
and of the degree of extinction obtainable are shown graphically
it is shown that the wave is elliptically polarized by inserting
a quarter wave unit to produce a linear polarization
   /
8388
electron spin resonance absorption in metals part experimental  measurements
were made on li na k be mg al pd and w over the temperature
range using a cavity resonator technique at frequencies of and  the
dimensions of the specimens were in some cases large and in others
small compared with skin depth  the results are compared with those
predicted by dysons theory
   /
8389
electron spin resonance absorption in metals part theory of electron
diffusion and the skin effect
   /
8390
inversion spectrum of ammonia  as a result of an investigation over
the frequency range lines have been found and lines remeasured
   /
8391
theory of molecular oscillator and molecular power amplifier  theory
is given of a device similar to that described by gordon et al of
january  the condition for self excitation is stated and expressions
are given for the frequency amplitude and maximum power output of
the oscillator and for the power amplification factor and the condition
for linear amplification of the amplifier
   /
8392
a conductivity type molecular beam detector  an iodine molecular
beam can be detected by observing the change in conductivity due
to introduction of impurities in a cu film detector  the detection
threshold of this device which is briefly described is about molecules
cm
   /
8393
observations of a variable radio source associated with the planet
jupiter  a variable source of radiation on was observed on nine records
out of a possible obtained during the first quarter of  the derived
position of the source corresponds to that of the planet jupiter
   /
8394
monochromatic character of bursts of solar rf radiation  bursts of
solar radiation in the region were recorded simultaneously by two
receivers tuned to frequency bands about apart  analysis of the observations
indicates that the average effective bandwidth of all bursts
is about and that of high intensity bursts ie with intensities more
than above the average is about  a note on similar work was published
by e blum
   /
8395
correcting for gaussian aerial smoothing
   /
8396
results of observations of scattering of rf waves by electron inhomogeneities
of the solar corona  results similar to those reported by
machine and smith were obtained in observations of the occultations
of june and  the observations were made at wavelengths between and
in interferometer base lengths of and were used at giving beam widths
of and respectively  rapid amplitude changes were noticed those associated
with changes within a few seconds are believed to be due to the
relativistic motion of electron inhomogeneities those of the order
of a few minutes to corpuscular streams
   /
8397
on an interplanetary magnetic field  arguments are presented for
the existence of an interplanetary magnetic field f intensity not
exceeding g  such a field would explain the observed cut off in the
primary cosmic ray momentum spectrum and time delays in solar terrestrial
phenomena
   /
8398
radio echo observations of meteors in the southern hemisphere  results
are presented of observations at adelaide using apparatus similar
to that described by aspinall et al operating on a frequency of and
by robertson et al operating at for measurements of shower radiants
and upper atmosphere winds respectively
   /
8399
solar rf radiation at cm wavelength  the total emission at depends
on both total area and position of sunspots  the variation with distance
of the sunspots from the centre of the disk is expressed by a darkening
factor whose value has been determined directly by observing the
passage of groups of spots and by assigning trial values and comparing
the resulting value of total emission with observations  results
by the two methods are in agreement  consideration of absorption
variations to be expected in consequence of variations of sunspot
position indicates that the darkening must be partly due to the change
of geometric form of the emitting areas
   /
8400
the sunspot cycle bc to ad  analysis of available records indicates
that the mean period of the fundamental sunspot cycle is years the
length of the length of the cycle varying in the opposite sense to
auroral activity there is also a long term cycle with a period of
years
   /
8401
solar prominences and geomagnetic disturbance  an attempt by statistical
analysis of solar data to identify the solar m regions with the large
prominences observed at intermediate and high solar latitudes gave
negative results
   /
8402
observations of the infrared radiation during the solar eclipse of
june in tashkent  results presented graphically show the changes
during the eclipse of the fraction of the total incident flux contained
in the infrared band curve
   /
8403
time relationship of small magnetic disturbances in arctic and antarctic
   /
8404
solar terrestrial time delays  the observed delay of about hours
between the meridian passage of a sunspot or flare and the onset
of an associated magnetic storm or aurora is shown to originate in
the deflection of the ion streams involved by either a solar magnetic
dipole of moment or an interplanetary magnetic field of intensity
or a combination of the two
   /
8405
seasonal variations of the intensity of bands due to oh and o molecules
in the atmosphere in the luminescence of the night sky
   /
8406
post twilight and nocturnal variations of intensity of oh ad o bands
in the near infrared  luminescence of the night sky
   /
8407
first investigation of ambient positive ion composition to by rocket
borne spectrometer  measurements were made in the range atomic mass
units amu  the most prominent ion peaks found at altitudes between
and km on the ascent were at and amu from to km ions of and amu persisted
   /
8408
the influence of the sunspot cycle on the f transmission factor
an analysis of results obtained over a period of eight years by a
number of stations north and south of the equator shows that the
influence of the sunspot cycle on the height of the f layer exhibits
a seasonal and a diurnal variation with a maximum effect in the afternoon
noon and midnight values of the f factor cannot be taken as representative
of day and night
   /
8409
a note on radio field strength observations made at ahmedabad during
the total solar eclipse on june
   /
8410
instrumentation for the continuous measurement of certain ionospheric
echo characteristics  details are given of the receiving system associated
with the equipment described by jones of  a crossed loop aerial
picks up both the direct and the reflected waves from the transmitter
about km away  the elliptically polarized echo is resolved into
components which are appropriately combined and displayed in succession
on a cro examples are shown of continuous photographic records obtained
the resolution of split echoes is facilitated by suitably varying
the cro beam intensity
   /
8411
a panoramic ionospheric recorder for the study of travelling disturbances
in the ionosphere  a description is given of a recorder covering
the frequency range in or sec  this is achieved by heterodyning an
oscillator which is continuously variable from to with a pulsed oscillator
and amplifying the resultant pulsed signal to provide the transmitter
output  the same variable oscillator is used in the superheterodyne
receiver  a block diagram of the recorder is given and typical records
are shown  both single records on mm film and continuous records
on mm film moving at or in min can be made using cr tubes with long
and short persistence screens respectively
   /
8412
modern ionosphere sounding equipment of the netherlands ptt part
high power slow sweep equipment is described  the tuning mechanism
comprises a set of simultaneously and continuously variable coils
and capacitors covering the range in on band  sweep time is  pulse
output power is about pulse repetition frequency is usually a special
camera with continuous film transport is used
   /
8413
a note on factors affecting the interpretation of observations of
transient echoes from the ionosphere
   /
8414
notes on correlation methods for evaluating ionospheric winds from
radio fading records  a method requiring only six values of the correlation
coefficient obtained from fading records at three receiver stations
is developed  the theory is extended to include elliptical constant
correlation contours in the horizontal plane  data obtained during
february indicate that the correlation ellipse shows a preferred
orientation and that fading associated with random changes in the
ionosphere is as important as that associated with drift
   /
8415
results of lightning measurements during the years on monte san salvatore
electrical magnetic and optical measurements made with the equipment
described previously of september are reported and discussed
   /
8416
nature of ball lightning  energy considerations indicate that ball
lightning can be sustained neither by a chemical process nor by a
nuclear process  it is suggested that the luminous ball could be
produced in a weakly ionized gas by a resonance process the energy
required to increase the ionization and then to maintain it inside
a sphere of diameter d being supplied by rf waves with d  the centre
of the sphere would coincide with a maximum of the wave interference
field  the rf waves could be due to an oscillatory process in the
ionized atmosphere excited by a lightning discharge  the proposed
mechanism also explains bead lightning the absence of influence of
wind on the position of the luminous ball and the waveguide effect
of chimneys  explosive and quiet types of decay are associated respectively
with rapid and slow changes in the rf field strength at the
end of the phenomenon  observations in the decimetre region during
thunderstorms and experiments on the artificial production of ball
lightning are suggested
   /
8417
radio observations of the aurora  observations during the period
by means of transmissions over n america mainly at indicate that
the ionization aurora occurs with greatest frequency near the equinoxes
as does the visual aurora
   /
8418
silicon solar energy converters  theory of operation of the si junction
photodiode is given and compared with experimental data  si is shown
to be the most efficient semiconductor available for conversion of
solar energy  a design is discussed in which the radiation is incident
on the n layer  the thickness of the p layer is required to be low
to give low resistance but not so low that minority carriers recombine
before diffusing to the junction  resistance at the metal contacts
must be kept as low as possible  conversion efficiences of have been
attained  possibilities are indicated of improving the efficiency
by use of nonreflecting coatings or auxiliary mirrors and lenses
   /
8419
regulated dc power supplies at low voltages  a valve stabilized unit
with dc output at or at is described as well as a unit using ge junction
rectifiers  the limitations of cold cathode tube stabilizers are
discussed
   /
8420
review of electronic computer progress during
   /
8421
a commercial electronic calculator  the main features common to three
business accounting machines are briefly described  the method of
performing the four basic arithmetic functions is illustrated by
worked examples
   /
8422
a miniature analogue computer  the computer described is capable
of solving linear differential equations of orders up to the tenth
and is intended for preliminary design investigations and educational
purposes
   /
8423
electrical analog computing machine for solving linear equations
and related problems  a computer for solving equations with ten variables
by a new iteration method is described  in addition to the solution
the machine gives the largest eigenvalue of the matrix of the linear
system
   /
8424
a high speed permanent storage device  a digital computer storage
system is described using a magnetic core matrix of in combination
with the threaded core system used in the bell computer model the
capacity is about a million bits
   /
8425
linear algebraic computation by multi winding transformers  theory
is presented of transformer circuits fol solving simultaneous equations
and inequalities the reduction of errors due to transformer imperfections
is discussed  the practical aspects are illustrated by a problem
involving checking the compatibility of ten inequalities with six
variables  the present device is similar to that described by mallock
and
   /
8426
a transistor digital fast multiplier with magnetostrictive storage
the multiplier is operated at a basic frequency of and comprises
timing waveform generator arithmetic unit and storage system  except
for the use of junction transistors in the amplifiers associated
with the storage system point contact types are used throughout
out of a total of point contact transistors junction transistors
and crystal diodes three point contact units have failed in seven
months of daily operation  no selection of transistors is required
the total power consumption is
   /
8427
the solution of plane stress problems by an electrical analogue
method  it is shown that the h biharmonic equation which airys stress
function has to satisfy can be solved by an electrical analogue comprising
two resistance networks in cascade
   /
8428
three dimensional electrical analogue models for studying drainage
by free surface filtration
   /
8429
transistor amplifiers for analog computers
   /
8430
the cold cathode gas diode  an outline is given of technique used
to improve the diode characteristics involving aging by application
of voltage pulses  basic circuits using these diodes as computer
elements for gating storage etc are described
   /
8431
language translation by electronics novel application of digital
computing machines
   /
8432
the single layer solenoid as an rf transformer design curves are
presented for air cored transformers  inductances of coupling coefficients
of and inductance ratios of are covered directly
   /
8433
the radio frequency coaxial resistor using a tractorial jacket  design
of resistors for the reflection free termination of coaxial lines
is discussed  using an approach based on treatment of a short length
of the resistor as a conical coaxial line the resulting profile of
the jacket is a tractrix  detailed analysis indicates that with this
configuration the field satisfied the boundary conditions better
than with an exponential jacket  the most important design parameter
is the ratio length diameter for resistances values of this ratio
between and are satisfactory  the difficulty of obtaining uniform
distribution of resistance over the surface of the resistor may be
a limiting factor in the accuracy of the termination
   /
8434
high value organic film resistors  stable resistors of resistance
are prepared by coating a dispersion of eg colloidal carbon in gelatine
on a glass support and mounting the unit in an evacuated enclosure
   /
8435
production characteristics and applications of nonlinear resistors
   /
8436
a shifting register using ferroresonant flip flops  an arrangement
is described in which the information can be shifted in either direction
depending on the polarity of the shifting pulse  consideration is
given to design for operation with supply frequencies in the mcs
range
   /
8437
a two state light activated circuit element using germanium  a bar
of n type germanium with a potential difference across its ends and
a suitably biased point contact near the middle will show double
base diode action  the point contact diode will conduct or cease
to conduct according as one end or the other of the bar is illuminated
both states being stable when the light is removed  in practice the
bar is divided near the point contact and the two parts are connected
by copper wire to ensure that holes generated in one section recombine
before they are swept into the other
   /
8438
etched foil printed circuits  discussion with particular f reference
to photomechanical methods of production
   /
8439
a theorem on the decomposition of the derivative of the operational
impedance of a two pole network
   /
8440
dynamic measurements on piezoelectric resonators with very strong
electromechanical coupling  the equivalent circuit used as the basis
of measurements on quartz crystals is not suitable in conditions
of strong electro mechanical coupling such as exist in ferroelectric
crystals at the curie point  the complete equivalent circuit for
longitudinal resonance in such conditions includes a number of parallel
branches whose contributions to the total piezoelectric current correspond
to the coefficients of a fourier representation of the oscillation
mode  results given by the theory are compared with observations
of the oscillations of a rochelle salt resonator
   /
8441
tuning of a rectangular parallelepiped cavity resonator with a circular
metallic post  a relation is derived between the resonance frequency
and small displacements of a post projecting into the resonator using
a perturbation formula due to slater of  the calculation is carried
out to the first order for a rectangular cavity operating in the
mode the result is compared with a similar relation for a right circular
cylinder whose length is varied by a plunger completely closing one
end
   /
8442
quantum effects in the interaction between electrons and high frequency
field part  reported an analysis of the effect of the interaction
on the motion of the electrons the effect on the field in the resonant
cavity is now analysed  the value of the field strength differs from
the classical value by a small amount due to the wave properties
of the electrons  the dispersion in the field is evaluated and the
number of electrons required in a bunch to produce a field comparable
to the dispersion is calculated  for typical experimental conditions
the highest frequency at which this requirement can be met is of
the order
   /
8443
collapsed toroidal springs as contact elements in microwave cavities
   /
8444
on extraordinary phenomena in a nonlinear forced oscillation  the
nonlinear forced oscillation represented by is discussed  transforming
the equation to the variational form the ritz method is applied to
obtain the solution in the form of a fourier series in which extraordinary
points of two different kinds are distinguished  this method
is applied to find the jump voltage of a circuit containing an iron
cored reactor
   /
8445
investigation of coupled electrical circuits with constant lumped
parameters under variable conditions part analysis involving the
inverse laplace transform is presented for determining the current
in the secondary circuit  numerical examples are given
   /
8446
a note on the application of determinants to the solution of linear
network problems
   /
8447
coaxial cavity filters for multiplexing of radio relay systems  essentially
full text of paper to be published in filters are discussed
comprising cascaded coaxial line sections the selectivity attained
permits a frequency separation as low as between a transmitter and
a receiver operating on a common aerial and a separation as low as
between transmitters or receivers
   /
8448
transient response of band pass filters  analysis for multistage
band pass amplifiers with parallel rlc coupling circuits is based
on consideration of the characteristic values of the individual circuits
   /
8449
a band pass filter with active elements  the design of a filter amplifier
is described in which impedance inversion and loss compensation
are achieved using two npn junction transistors type in an arrangement
based on the valve circuit described by harris of  the centre frequency
of the filter is and the bandwidth is and at the and points respectively
a complete unit shown includes a third transistor with grounded
emitter connection and gives an overall gain of db
   /
8450
loss and phase of simple equalizers  approximate computations are
performed using the first one or two terms of a rapidly convergent
power series expansion
   /
8451
the noise figure of linear quadripoles and amplifier valves
   /
8452
on subharmonic synchronization of nearly linear systems  analysis
is presented for a slightly nonlinear oscillator driven at a frequency
near a multi  le of its natural frequency the system corresponding
to the equation where the forcing term is of the order of unity
conditions for obtaining a response at angular frequency are investigated
by expanding y in a series in
   /
8453
symposium on fluctuation phenomena in microwave sources
   /
8454
a twin t rc oscillator  the design of a oscillator similar to that
described by francini and zaccheroni of is briefly discussed  performance
characteristics are presented graphically  the frequency is variable
over a limited range
   /
8455
a triggered timebase for oscillographs  a triggered sawtooth generator
is described
   /
8456
transistors generate multiwaveforms  the use of junction transistors
as nonlinear network elements is illustrated by a discussion of the
design of a regenerative degenerative oscillator
   /
8457
approximate calculation of the relaxation process and time delay
in the multivibrator  calculations are presented based on representation
of the valve characteristic curves by third degree polynomials  a
delay of about sec between the initiation of instability and the
commencement of the anode pulse is found for a particular circuit
using type ef pentodes
   /
8458
a new method for generating relaxation oscillations with a gas filled
triode  large amplitude relaxation oscillations can be generated
by applying a small hf voltage to the grid of a gas filled triode
in which the grid is connected to the cathode via a high resistance
the waveform of the relaxation oscillation depends on the parameters
of the circuit in parallel with the anode to cathode path and on
the excitation frequency and the frequency of the relaxation oscillation
can be varied over a wide range
   /
8459
a transistor oscillator  a high stability portable oscillator uses
a single point contact transistor and a quartz crystal resonator
in a wien bridge circuit  the frequency variation is for supply voltage
variations of or more
   /
8460
a guide to the design of sinusoidal oscillators using junction transistors
oscillators based on series and parallel resonant circuits rc
phase shift networks negative resistance effects and control crystals
are included
   /
8461
contribution on the problem of frequency dividing  dividing circuits
for both pulse and sinusoidal signals are discussed  details are
given of a simple locked in oscillator giving division factors up
to a self starting regenerative divider and a divider with controlled
oscillator a laboratory model of which gives division factors in
a single step
   /
8462
contribution on the problem of feedback a review of methods for analysis
and design of feedback amplifiers
   /
8463
all pass amplifier  in a five stage amplifier for the frequency range
having an overall gain of high frequency attenuation is reduced by
using the parasitic capacitances of the valves ar as elements in
a high pass filter
   /
8464
the design of stagger tuned double tuned amplifiers for arbitrarily
large bandwidth
   /
8465
asymmetry zero drift errors in magnetic amplifiers
   /
8466
transistor amplifiers for analog computers  high and low gain transistor
m amplifiers for servo use are described effects of power supply
variations and temperature coefficients are shown
   /
8467
temperature compensation in a low consumption transistor amplifier
the circuit design is developed for a two stage amplifier for the
frequency range giving a stable distortion free output of with an
ambient temperature variable over the range by suitable choice of
circuit elements compensation is obtained without increased power
consumption and the amplifier characteristics may be made independent
of the actual transistors used
   /
8468
unilateralization of junction transistor amplifiers at high frequencies
neutralization of the inherent internal feedback of the junction
transistor is provided by applying external feedback  practical circuits
are illustrated and their performance characteristics discussed
   /
8469
carrier leak in rectifier modulators of the shunt type  carrier leak
is the term used for the unbalance carrier frequency component in
the modulator output  an experimental investigation is reported of
factors affecting the attainment of very low leak levels from to
below carrier level and of the possibilities of dc balancing of the
rectifier bridge  square wave and sinusoidal signals are considered
the results indicate that control of carrier leak adjustment by use
of a dc meter is likely to be practical  the effect of carrier generator
impedance is discussed  some details are given for a modulator with
no transformer  very low leak levels are attainable by correct relative
j adjustment of the two coupling capacitors
   /
8470
a new aether drift experiment  results of the experiment referred
to previously of are reported  a cylindrical cavity resonator used
to control the frequency of an oscillator at about was mounted with
its axis horizontal and was rotated in a horizontal plane  the frequency
of the oscillator was compared with that of a quartz standard at
intervals of of the rotation
   /
8471
some aspects of standing wave patterns  general analysis is given
for the production of standing waves and three dimensional patterns
obtained by plotting the wave equations are presented for various
cases
   /
8472
specific directions of longitudinal wave propagation in anisotropic
media  analysis relevant to piezoelectric oscillations is presented
trigonal hexagonal tetragonal and cubic crystals are considered and
the directions of propagation of purely compressional waves are determined
   /
8473
electroluminescence  a survey of existing knowledge of the physical
process involved with numerous references
   /
8474
recommendations of iec international electrotechnical commission
technical committee electric and magnetic magnitudes and units  full
text of paper to be published also in communication and electronics
recommendations made at the meeting i september are reported
   /
8475
plasma oscillations in metals  the effect of the energy band structure
on the plasma frequency is analysed
   /
8476
theory of anomalous skin effect  an exact expression is derived for
the surface impedance for the case of arbitrary dispersion of conduction
electrons assuming an infinitely long mean free path  the conclusions
are the dependence of the impedance z on the angle between the normal
to the surface and the crystallographic axes is determined by tensor
the frequency dependence of the impedance and the relation between
the real and imaginary parts of z are independent of the form of
the dispersion relation the derivation of equation for is independent
of the interaction of electrons with the lattice and hence may be
used in the determination of the fermi surface
   /
8477
influence of inhomogeneity of a plasma on its resonance frequency
nonuniformity of the electron concentration in the plasma may give
rise to variations of in the resonance frequency  this explains the
langmuir relation and experimental results  the effect of damping
is however negligible as are also magnetic effects
   /
8478
high frequency ionization coefficients in neon argon mixtures
   /
8479
electrical breakdown of air at small and medium overvoltages  experimental
results indicate that values of pressure distance about torr
cm breakdown due to overvoltages of to is produced by a townsend
ionization mechanism rather than by the electron avalanche build
up of a channel as described by raether  at overvoltages the latter
process is operative
   /
8480
electrical breakdown in high vacuum  report of an investigation using
gaps shorter than cm between tungsten electrodes  in most cases of
breakdown field emission currents from small irregularities on the
cathode cause evaporation of metal from the anode the breakdown occurring
in the resulting vapour
   /
8481
noise from hot cathode discharges  experiments with mercury vapour
tubes in which anode glow disturbances were eliminated show that
low frequency noise in an unsaturated discharge is due to a coherent
random fluctuation of the whole plasma probably caused by fluctuations
of the cathode sheath  under certain conditions another effect was
distinguished which may e be due to fluctuations of sheaths on the
probes used or on the tube walls
   /
8482
work function of tungsten single crystal planes measured by the field
emission microscope
   /
8483
wave mechanics treatment of electron and ion beams with curved axis
   /
8484
velocity analysis of thermionic emission from single crystal tungsten
the energy distribution of electrons emitted in various directions
from the w filament was analysed using a special tube in which the
electron trajectories were bent by a magnetic field  the observed
distributions were the same for all directions ad were not maxwellian
variations of true work function over the temperature range were
measured for several crystallographic directions  the results are
discussed in relation to values of the richardson emission constant
found by other workers
   /
8485
possibility of defining a scalar magnetic potential inside currents
and application to the design of magnetic electron lenses  the system
considered is a thick solenoid various equivalent magnetic shell
systems and the corresponding magnetic potential distributions are
discussed
   /
8486
electromagnetic theory of moving matter  conceptual difficulties
arising in connection with the didactical presentations of classical
theory are discussed using an alternative approach to that of hammond
of january
   /
8487
the angular momentum of the electromagnetic field
   /
8488
observations on an energy relation in magneto hydrodynamics
   /
8489
correlation of amplitude and phase fluctuations in wave propagation
in a medium with random inhomogeneities  the two problems noted in
of april are treated more fully  the value of the correlation coefficient
r between amplitude and phase fluctuations at the receiving point
is given by equation and reduces to for small distances and to in
for large distances where is given by where and is the dimension
of the inhomogeneities  the autocorrelation coefficient for amplitude
fluctuations o at points and is plotted as a function of in curve
that of phase fluctuations in curve the curves refer to the case
when d and lies between and
   /
8490
theoretical and experimental study of electromagnetic scattering
by two identical conducting cylinders  the scattering of a cylindrical
tem wave by two parallel identical conducting circular cylinders
is developed as a special case of a theoretical analysis which treats
the scattering by an arbitrary array of cylinders  only the case
with the incident e vector parallel to the axes of the cylinders
is considered and attention is focused on the mutual effects present
when the cylinder diameter and spacing are comparable to a wavelength
the approximations made in the theory are tested experimentally using
microwaves in a parallel plate region  significant departures from
the results of the independent scattering hypothesis as predicted
by the theory have been confirmed experimentally
   /
8491
diffraction of electromagnetic waves by circular plate and circular
hole  rigorous analysis is presented using the method of expansion
by the hypergeometric polynomial  total scattering cross section
transmission coefficient current in the disk field in the hole ad
field at a distant point are shown graphically as functions of where
and is the radius
   /
8492
microwave diffraction by apertures of various shapes  results of
an experimental investigation of the near zone diffraction field
of circular elliptical and slit apertures are presented  in general
these results are consistent with theory presented previously
   /
8493
the scattering of a scalar wave by a semi infinite of rod of circular
cross section  analysis indicates that for a wave incident along
the axis of the rod and assuming zero variation of field with distance
at the end surface corresponding to the case of sound waves incident
on a rigid rod the scattering coefficient is for where k is the wave
number and a is the radius of the rod  graphs show the variation
of the average pressure amplitude on the end of the rod and of the
scattering coefficient over the range  the average pressure amplitude
on the end of the rod for other angles of incidence is calculated
an expression is derived for the scattered field when the field at
the surface is zero corresponding to the case of an aerial when only
the component of the electric field parallel to the axis of the rod
is considered
   /
8494
scattering of a plane wave from a circular dielectric cylinder at
oblique incidence  analysis is presented for the general case  the
solution indicates that the scattering field includes a significant
cross polarization component which vanishes at normal incidence
the results are applicable to scattering by ionized columns such
as meteor trails
   /
8495
polarization of electromagnetic waves  basic relations of polarized
em waves are expressed in vector notation  use is made of the vector
of refraction m defined as the product of the refractive index and
the real unit vector of the wave normal
   /
8496
nonlinearity of propagation in ferrite media  measurements are reported
emphasizing the need to take account of nonlinearity effects when
designing microwave ferrite devices for use at high peak power levels
the results are applicable for conditions remote from gyromagnetic
resonance
   /
8497
magnetic resonance for arbitrary field strengths  discussion is presented
for a paramagnetic gas assuming that strong collisions are the
only important factor apart from the applied magnetic field and that
the latter comprises a circularly polarized component in the plane
perpendicular to the constant components
   /
8498
interpolation scheme for energy bands in solids
   /
8499
the distribution of temperature along a thin rod electrically heated
in vacuo part end losses the correction for end losses is calculated
for some typical physical properties which are functions of powers
of temperature t or both as in thermionic emission  the calculated
corrections for a long w filament agree closely with those computed
graphically by worthing  the corrections for medium length filaments
such as used in hf power valves are practically the same as those
for a long filament heated by the same current
   /
8500
electrodynamical theory of thermal radiation  a theoretical note
on thermal electrical fluctuations phenomena in cavity resonators
and waveguides are considered
   /
8501
radio astronomy  a brief survey of techniques results and applications
   /
8502
a radio survey of the great loop in cygnus  some details are given
of a radio source discovered as a result of a survey made at jodrell
bank at a frequency of
   /
8503
new modulation system of radio reception of weak signals and its
application in the design of a radiotelescope of extremely high resolving
power  features of the systems described by vitkevich of and mills
and little see eg of were combined to give a high resolution a swinging
aerial beam is obtained by varying the electrical lengths of the
feeders  the system is explained with the aid of a block diagram
   /
8504
a solar noise outburst of january  outbursts of noise were observed
at ottawa with an interferometer type receiver at a frequency of
on and january  a study of the vertical incidence ionosphere records
indicates that storm conditions with spread f echoes low values of
f increased absorption and blackout followed the outbursts  auroral
displays were reported from parts of canada and the us during the
period
   /
8505
change of radio signal strength during solar eclipse june
   /
8506
a simple sensitive saturated core recording magnetometer
   /
8507
the vertical distribution of atmospheric ozone determined by baloon
ascents  measurements made with an automatically recording ultraviolet
spectrograph are reported
   /
8508
d layer ionospheric echoes at macquarie island  echoes from d layer
heights have been recorded at the australian station on macquarie
island geomagnetic latitude i since operation started in  echoes
are of similar type to those observed in tropical latitudes and occur
on most days of the year  on a few occasions each month echoes persist
throughout the night  the highest frequency at which echoes are received
usually increases from below at first appearance within an hour after
ground sunrise to above at noon decreasing to below at disappearance
during the hour before sunset  strong d echoes remain on occasions
when other daytime echoes are absent due to high absorption  the
effect may be peculiar to island observatories
   /
8509
the effect of vertical ion transport on the night time e region
anomalous behaviour of the night time e layer and the formation of
the night time sporadic e layer may be explained by vertical ion
drifts not necessarily tidal
   /
8510
on anomalous variations of maximum electron density and its height
in the region of the ionosphere  an examination of world wide observations
during periods of sunspot maximum and minimum suggests that anomalous
behaviour of the f region is mainly controlled in low and middle
latitudes by geomagnetic factors and in higher latitudes by geographic
factors  the fall in the level corresponding to maximum electron
concentration over the magnetic equator may be accounted for by vertical
electron drifts whose magnitudes are deduced seasonal anomalies in
f may be explained by variations in the height distribution of the
particles from which the ions in the region are produced
   /
8511
on latitudinal distributions of diurnal and semi diurnal components
of of the ionosphere  results of an analysis of world wide observations
for december and june are given in a series of histograms
   /
8512
on the solar lyman d beta radiation and the ionosphere  solar lyman
radiation i will be absorbed by atomic oxygen in the ionosphere with
emission of a radiation  observation of such radiation originating
in the r region would be a criterion for the validity of the ionospheric
model
   /
8513
geomagnetic distortion of the f region on the magnetic equator  calculations
based on an atmospheric model inferred from rocket observations
and using the dynamo theory of the earths magnetic field show that
the diurnal variation of the vertical electron drift due to the es
field is sufficient to account for the observed distortion of the
f region over the magnetic equator the presence of the f layer is
also accounted for  changes following the sunspot cycle may be caused
by a slight shift of the phase of the drift
   /
8514
studies on the disturbances in f layer associated with geomagnetic
disturbances  f layer disturbances associated with geomagnetic storms
consist of two components which is effective only in the earlier
stage and is dependent on longitude and which begins simultaneously
with the f storm and gradually grows to large amplitude hours later
variations with latitude and season are plotted from world wide data
for the period the disturbances follow the trend of geomagnetic activity
except for in winter  the effect of sunspot activity is shown
   /
8515
diurnal and seasonal wind variations in the upper atmosphere  results
are presented graphically of observations of winds at altitudes of
made at jodrell bank between september and november  the measurements
were based on radio reflections from meteor trails of greenhow  four
distinct wind components were distinguished with semi diurnal periodicity
of amplitude rotating clockwise with diurnal e periodicity of
prevailing winds of towards the east in summer and winter and towards
the west in spring and autumn turbulent winds of the order of with
occasional wind shears of over height differences of a few kilometres
   /
8516
electrostatic field changes due to lightning discharges  report and
analysis of extensive observations at distances in this range es
effects are dominant over induction and radiation effects
   /
8517
the development of lightning discharges  the observations reported
in above are discussed and thd theories are advanced regarding the
nature of lightning processes
   /
8518
the location and shape of the auroral zone  observed characteristics
of aurorae and examination of data for the polar year support the
view that an electrically neutral particle stream coming from the
sun is resolved into positive and negative components on encountering
the earths magnetic field the two components following opposing spiral
tracks into the auroral zone
   /
8519
noise power radiated by tropical thunderstorms  lightning discharge
phenomena are reviewed and an expression is derived for the average
electric field due to a stroke the power at the source corresponding
to the noise field strength measurements of which were reported previously
of january is hence evaluated  over the frequency range the noise
power varies as  discharges within the cloud or into the air are
the main noise sources
   /
8520
an alternating voltage source of high stability at standard frequency
description of a three phase constant voltage source provided by
a synchronous generator with quartz clock controlled frequency developed
for testing ac precision instruments
   /
8521
filters for rectifier equipment  the design is discussed of series
tuned lc filters in parallel with the output of a multiphase rectifier
for attenuating unwanted harmonic voltages  the design of a series
reactor for limiting the rectifier output current is also briefly
considered
   /
8522
application of germanium power rectifiers  commercially available
power supply units are described with ratings such as at and at
   /
8523
electronic voltage regulators  relatively simple circuits giving
a high degree of stabilization have been designed at the national
bureau of standards using beam power series valves with separate
screen supplies  a power supply unit is briefly described containing
four regulated sources and giving outputs of and
   /
8524
an ac voltage stabilizer  high regulation factor short response time
low e weight and frequency independence are achieved in a valve regulator
with a carbon pile variable resistor control element and local
as well as overall feedback  in the form described the regulator
is suitable for supplying filament current for a large number of
valves
   /
8525
high speed electronic analogue computing techniques  an investigation
has been made of the upper limits of speed conveniently attainable
in various basic operations performed with a particular differential
analyser  with multidimensional displays and electronic programming
a very large increase in information capacity is attainable in problems
requiring systematic search processes for their solution
   /
8526
a mercury delay line storage unit
   /
8527
magnetic memory device for business machines  description of a device
combining the short access time of a magnetic drum and the larte
storage capacity of the tape record
   /
8528
synchronizing magnetic drum storage speed  synchronization to an
acoustic delay line is obtained by a time difference discriminator
which controls the drum speed  an accuracy within is achieved with
a line voltage variation
   /
8529
square law circuit  a device for use as a multiplier in a analogue
computers consists of a source producing a negative going triangular
waveform which is superposed on a positive going input signal applied
to a diode  the average value of the output voltage is proportional
to the square of the input voltage
   /
8530
photoelectric transformation of mathematical functions solution of
equations  an arrangement comprising a mirror galvanometer in combination
with an appropriately shaped diaphragm and a photocell is used
to generate a current when the current flows through the galvanometer
elaboration of the arrangement to generate complex functions is discussed
   /
8531
binary adder tube for high speed computers
   /
8532
interesting new developments in the components istray reactances
in power and instrument transformers  saturating reactor magnetic
pulser design
   /
8533
the transfluxor a magnetic gate with stored variable setting  the
transfluxor is a device comprising a magnetic core with two or more
apertures the core material having a nearly rectangular hysteresis
loop  switching and storage operations are performed by controlled
transfer of the flux from leg to leg of the core  the operation of
a two aperture device is described in detail
   /
8534
transistor binary number store for pulse operations
   /
8535
the design of hard valve binary counters  the method of design takes
account of tolerances on component values valve characteristics and
supply voltages and indicates modifications necessary when se diodes
are used in place of hot cathode diodes for interstage coupling it
is valid at a counting speeds up to several
   /
8536
the relation between standing wave ratio and bandwidth in wide band
compensation of a reactance  calculations are made for two different
equivalent circuits representing a resistance accompanied by inherent
reactance  the swr obtained when the compensated resistance is connected
to a loss free line with purely resistive characteristic impedance
is used as a criterion of the compensation  the results are expressed
as irrational algebraic functions which are presented as bandwidth
curves  simple relations are derived between the permissible swr
and the bandwidth
   /
8537
the folded tree  the problem of constructing circuits to perform
certain functions such as switching functions is treated by representing
the circuits by vertex diagrams of which the folded tree is a particular
form
   /
8538
revolutionary new oscillator amplifier
   /
8539
effects of impurities on resonator properties of quartz
   /
8540
calculation of the oscillation frequency of a quartz crystal maintained
by a transistor the calculation presented previously of july is extended
to the general case where it is required to determine both the influence
of the maintaining system on the frequency and the possibility of
aligning this frequency with a given reference frequency  formulae
are derived based on the use of capacitors in series and in parallel
with the crystal
   /
8541
theory of imperfect waveguides the effect of wall impedance
   /
8542
wide range electronic tuning of microwave cavities  analysis is presented
for tuning by introducing into the cavity an electron beam with
its direction parallel to the magnetic field so that spiralling of
the beam is produced  measurements are reported indicating that the
tuning range is much greater for a cavity containing z a gas at low
pressure than for an evacuated cavity
   /
8543
series resonance with nonlinear capacitor  a graphical method is
used to explain multiple resonance and hysteresis in a circuit tuned
by a capacitor with a dielectric
   /
8544
unambiguous choice of arrow direction for currents and voltages in
quadripoles with applications to directional quadripoles and gyrators
it is recommended that the positive direction of the voltage arrow
should always point from positive to o negative charge with quadripole
diagrams the output current arrow should poin  away from the quadripole
simplifications of network analysis resulting from adoption of this
convention are indicated
   /
8545
conditions for aperiodicity in linear systems  the necessary and
sufficient conditions are derived when expressed in terms of the
coefficients of the characteristic equation they take the form of
a number of simple determinantal inequalities which are closely analogous
to the rough hurwitz stability criteria
   /
8546
definition of the ideal transformer and the ideal gyrator by their
impedance transforming properties  the fundamental difference between
the two networks is that the input impedance of the ideal transformer
is directly proportional to the load impedance while for the ideal
gyrator the proportionality is inverse  the ideal gyrator can be
completely defined as a passive linear loss free quadripole with
frequency independent transforming properties
   /
8547
a new method for investigating linear quadripoles part  continuation
of work abstracted in of october  a distinction is made between elliptic
hyperbolic parabolic and loxodromic quadripoles
   /
8548
two network theorems for analytical determination of optimum response
physically realizable network characteristics
   /
8549
how to design if transistor transformers  design curves are given
for single and double tuned units providing matching of collector
and base impedances while meeting bandwidth and minimum insertion
loss requirements
   /
8550
symmetrical lattice filters  the calculation and field of utility
of standard types of lattice filter are discussed and permissible
approximations are indicated  classification based on image parameters
is proposed on the lines of the system used in a previous paper on
ladder filters
   /
8551
note on antimetrical lattice filters with successive reactances of
alternate sign  a simplification of the treatment given by oswald
of january
   /
8552
notch network design  curves are given facilitating the design of
bridged t band stop filters operating between equal impedances
   /
8553
the period and amplitude of the van der pol limit cycle  the amplitude
and period of the limit cycle of the van der pol equation are found
for all values of by joining graphically the results of solutions
about and
   /
8554
limit cycle period of nonlinear oscillation  the problem is discussed
with reference to previous work on the solution of the van der pol
equation a formula is derived for the limit cycle period which is
applicable both for small and large values of corresponding respectively
to quasi sinusoidal and relaxation oscillations  results obtained
from various formulae are compared in a table
   /
8555
the design and performance of a simple vlf oscillator  using a wien
rc network for frequency control the oscillator covers the range
in finite steps with a maximum output of into a load
   /
8556
secondary emission valve pulse generator with cathode output  a positive
feedback circuit giving a very low output impedance is used capable
of producing pulses of amplitude with rise time about by using a
pentode as cathode load it is possible to obtain a wide variety of
pulse waveforms  the arrangement gives a better performance than
the ordinary blocking oscillator
   /
8557
investigation of the time delay in the triggering of a pulse in a
monostable multivibrator  results of experiments indicate that a
monostable multivibrator may be used as a pulse amplifier in applications
where waveform distortion is unimportant  with pulse voltages
above the multivibrator used showed time delays of less than and
these were independent of pulse width over a wide range  the gain
obtainable is about  time delays in a free running multivibrator
are of the order of to sec this is shown theoretically to be due
to the stray capacitances present
   /
8558
triggered microsecond sweep generators  hard valve balanced output
and single ended sweep generators are described using miller integrator
feedback for linearization both are capable of providing a sweep
in  applications in high speed photography are indicated
   /
8559
a time delay device using transistors  pulse shaping and counting
circuits are described in which junction transistors are used for
switching in conjunction with magnetic cores with rectangular hysteresis
loops  the number of pulses required to saturate the core is such
that long time delays can be produced  published also in communication
and electronics
   /
8560
high frequency pulse counter  a circuit based on the secondary emission
valve pulse generator described in above
   /
8561
all magnetic audio amplifier  three cascaded magnetic frequency triplers
are used to provide a carrier from a line frequency  used with a
carbon microphone and a two stage magnetic amplifier the system gives
and audio output power of with linear operation over the range cs
   /
8562
wide band frequency divider  a circuit for operation at frequencies
up to based on the secondary emission valve pulse generator described
in above
   /
8563
design of low pass amplifiers for fast transients  the proposed synthesis
of an interstage coupling network for wide band low pass amplifiers
is based on darlingtons design method of  some practical details
are given of a amplifier experimentally determined phase and amplitude
characteristics are presented graphically oscillograms of the transient
response are shown  details are also given of the design of a phase
correction network
   /
8564
the mechanism of subharmonic generation in a feedback system  analysis
is given for nonlinear feedback systems using the description function
method subharmonics are produced as a result of mu modification of
the response of the nonlinear element by the input signal  conditions
are derived for the absence of subharmonic oscillations  theoretical
and experimental results for a particular unit with an approximately
cubic characteristic are in agreement
   /
8565
disc seal circuit techniques  a survey of amplifiers and oscillators
using disk seal valves and of associated microwave measurement methods
   /
8566
on distributed amplification  the response characteristics of a distributed
amplifier can be improved by making the delay characteristics
of the anode and grid lines different this technique being termed
staggering  the improvement is illustrated y by photographic records
of the responses of experimental amplifiers
   /
8567
filters with very narrow pass band variable on the principle of the
fabry perot interferometer  analysis is given for a narrow band rf
amplifier with n equal stages each comprising a valve and a three
mesh cr phase shift network  maximum gain is obtained at a frequency
slightly different from that for which the phase shift is  a relative
bandwidth of is attainable with stages
   /
8568
note on the design of wide band low noise amplifiers  methods of
reconciling the design requirements for minimum noise factor and
those for adequate bandwidth are discussed  the problem can be solved
by equalization using either feedback or complementary networks
some measurements on an experimental grounded cathode amplifier with
feedback are reported satisfactory performance with bandwidths up
to about appears possible
   /
8569
figure of merit in magnetic amplifiers  the figure of merit discussed
is the ratio of power amplification to amplifier response time  it
is useful as a basic for the comparison of amplifiers which are linear
over the working range and have equal rated output powers
   /
8570
transistor operating points  a theoretical and experimental investigation
is reported of the relation between the junction transistor noise
and gain and the collector to base voltage the results are used in
the design of a high gain low noise amplifier
   /
8571
automatic gain control of transistor amplifiers  satisfactory agc
circuits can be designed based on variation f either emitter current
or collector voltage v  the required control power is very low if
the variation of is produced by varying the base current  distortion
may become a serious problem
   /
8572
transistor equivalent circuits
   /
8573
transistor equipped light weight programme input amplifier type
an amplifier for a portable sound recorder is described  in the pre
amplifier the microphone is matched to the first transistor via a
transformer  by use of current feedback in the first stage it is
possible to connect without attenuation capacitance microphones with
terminal resistance  the second stage includes a feedback circuit
providing equalization up to kcs  the final stage is designed for
an output of mw  shifting of the working point due to internal heating
is reduced by use of a special stabilizing circuit
   /
8574
millimicrosecond pulse techniques  a survey with an excellent bibliography
   /
8575
note on carpet graphs  description of a method description of a method
developed at the national physical laboratory for presenting information
concerning three variables in a single combined graph
   /
8576
theory of electroluminescence  on the basis of the threshold value
of the field necessary to excite luminescence the following three
possible mechanisms are discussed direct ionization of impurity systems
by the field acceleration of conduction electrons or valence band
holes to velocities sufficient to produce excitation by inelastic
collisions injection of charge carriers
   /
8577
empirical relationships with the munsell value scale  a discussion
relevant to the establishment in colour television of an equal step
grey scale
   /
8578
the specification of colours based on measurements with the trichromatic
colorimeter
   /
8579
a general mathematical treatment applicable to certain electrode
systems  formulae are developed for a basic system of two coaxial
dielectric cylinders of different homogeneous and isotropic media
containing an embedded line charge  these are applied to determine
the field in a circular cylinder electrode system the result being
expressed as series converging reasonably rapidly  other electrode
systems considered are a semi infinite strip an elliptic cylinder
and a parabolic cylinder
   /
8580
on the theory of plasma oscillations in metals  the effect of the
crystal lattice on plasma oscillations is investigated on the basis
of quantum mechanics  see also of
   /
8581
application of the method of generating function to radiative and
nonradiative transitions of a trapped electron in a crystal  see
also
   /
8582
measurement of the statistical time lag of breakdown in gases and
liquids
   /
8583
the direct current associated with microwave gas discharge between
coaxial cylinders part  measurements made by a double probe method
give results in good agreement with theory
   /
8584
investigation of high frequency discharge by method of probes  the
methods used by banerji and ganguli were compared experimentally
the results obtained in the two cases were similar  a study was also
made of the temperature concentration of electrons and potential
along the axis of the discharge tube at various pressures between
about and mm hg of and at frequencies of the order of the distribution
was found to depend on the gas pressure the diameter of the tube
and the hf field strength  results are presented graphically
   /
8585
retrograde motion in gas discharge plasmas  a phenomenon observed
in cylindrical diodes operating in the ball of fire mode of is discussed
   /
8586
diffusion in moving striations  a digest is presented of a thesis
developing a diffusion theory of striations and testing the theory
with experimental results reported by pupp
   /
8587
field measurements in glow discharges with a refined electron beam
probe and automatic recording
   /
8588
interpretation of field measurements in the cathode region of glow
discharges
   /
8589
self focusing streams  a restatement of the theory of magnetic self
focusing of streams comprising a mixture of ions and electrons  see
also of
   /
8590
the theoretical possibility of separating beams of charged particles
having different polarizations in a magnetic field  it is shown that
a separation of beams such as is obtained in the stern gerlach experiment
can theoretically be obtained also in the case of charged particles
   /
8591
electron emission and other phenomena on freshly disturbed metal
surfaces  a general account of the effects and methods of observing
them using an open ended geiger counter or a photographic plate
   /
8592
a note on the diffusion in a gas of electrons from a small source
   /
8593
experimental investigation of the motions of electrons in a gas in
the presence of a magnetic field  the aim of this investigation was
to verify the theory given by huxley and
   /
8594
secondary electron emission  report of colloquium held at the institute
of physics in march
   /
8595
secondary electron emission by primary electrons in the energy range
of to  experiments were made using a primary beam from a small linear
accelerator after passage through a magnetic analyser and targets
of various metals  the secondaries comprised two groups one with
energy mainly and the other possibly elastically scattered with high
energies  curves show both the total secondary emission and the high
energy component as functions of primary voltage for various target
metals for a gold target the energy spectrum of the low velocity
secondaries is investigated  another graph shows the high energy
components plotted against the atomic number of the target metal
some experiments with insulator targets are briefly reported
   /
8596
a demountable vacuum system for secondary emission studies
   /
8597
the growth f of an electron avalanche retarded by its own space charge
the calculation presented shows how the ionization coefficient and
the total multiplication in the avalanche vary with the distance
travelled when the positive ions formed have an appreciable effect
the time taken for an avalanche to develop is also calculated  the
cases of constant field at electrodes and constant potential between
them are considered assuming plane parallel geometry
   /
8598
passage of charged particles through plasma  a phenomenological approach
is used to examine the behaviour of a dispersive plasma and determine
its response to an external disturbance in particular that created
by a moving point charge  the validity of this approach is discussed
an analysis is made of the field and the polarization charge density
produced by an incident particle and the effectiveness of the plasma
in stopping the particle
   /
8599
microwave study of positive ion collection by probes  the electron
density in a plasma is determined from the shift in resonance frequency
of a cavity in which a discharge is maintained  the results are used
to verify theory of positive ion collection by negatively biased
or double probes  experiments were performed in h ar and he at pressures
from to mm hg  agreement between experimental and theoretical results
is good at the lower pressures at high pressures the probe collected
about twice the current predicted by theory
   /
8600
a short modern review of fundamental electromagnetic theory
   /
8601
magneto hydrodynamics  report of a royal society discussion held
in may
   /
8602
tatolectromagnetic field equations for a moving medium with hall
conductivity  the well known equation representing the electromagnetic
field in a moving isotropic conductor is adapted to treat the case
of an anisotropic conductor such as an ionized gas moving in a strong
magnetic field by introducing a tensor conductivity  the modified
equation is used to analyse astrophysical problems including the
propagation of magnetohydrodynamic waves
   /
8603
the motion of ionized gas in combined magnetic electric and mechanical
fields of force  transient electric and mechanical forces uniform
in space are applied to a gas in the presence of a steady magnetic
field  the current transport equation for the anisotropically conducting
medium is used to determine the subsequent motion of the gas the
internal electric field and the current density  these are damped
oscillatory functions leading to a steady state  there is a close
connection between the effects of the electric and mechanical forces
a steady internal electric field perpendicular to the magnetic field
cannot exist unless accompanied by a mechanical force  the relationship
between the two is examined
   /
8604
cerenkov radiation and its applications
   /
8605
reflection at arbitrary incidence from a parallel wire grid  the
analysis presented is valid for any direction of polarization angle
of incidence or value of wire conductivity
   /
8606
on the scattering of spherical waves by a cylindrical object  analysis
indicates that the ratio of the amplitude of the scattered field
for a spherical incident wave to that for a plane wave is equal to
where is the distance of the source and that of the observer from
the cylinder axis
   /
8607
revolutionary new oscillator amplifier  short simplified description
of the maser name derived from microwave amplification by stimulated
emission of radiation  see also of
   /
8608
a microwave spectrometer and its applications to some organic molecules
stark modulated microwave spectrometer operating in the frequency
range is described in detail circuit diagrams are given  spectra
of several asymmetric top molecules have been investigated
   /
8609
some magneto optical phenomena connected with the molecular resonance
of gases at micro wave frequencies  the production of birefringence
and faraday rotation is discussed quantitatively with particular
reference to nh
   /
8610
magneto hydrodynamics
   /
8611
new science of radio astronomy  a review of research methods and
results based on an address delivered to the american association
for the advancement of science
   /
8612
the spatial distribution and the nature of radio stars  data obtained
from a survey of radio stars by shakeshaft et al  to be published
in are analysed  the results indicate an apparent increase in the
spatial distribution density with distance in all directions  a reasonable
interpretation of the results cannot be provided unless most
of the stars are assumed to be outside the galaxy
   /
8613
an alternative identification of the radio source in the direction
of the galactic centre  an attempt has been made to determine the
distance of the radio source observed eg by from the absorption
by interstellar hydrogen at  the results suggest that this source
is considerably closer than the galactic nucleus
   /
8614
radio emission from jupiter  brief report of reception at seneca
maryland of radiation on a large cross aerial was used of the type
developed by mills see of the effect in a broadcast receiver was
similar to tht with thunderstorm interference  see also of october
   /
8615
radio waves from the planet jupiter and a cosmoggonic hypothesis
the reported observation of radiation at about of october burke and
franklin is discussed in relation to theories concerning physical
conditions on jupiter  it is suggested that saturn may also emit
radio waves but with lower intensity  theoretical considerations
indicate that astral heat and light may be a direct effect of the
gravitational force
   /
8616
meteor radiation ionization and atomic luminous efficiency  a theoretical
paper empirically constructed tables are presented for calculating
the radiation from meteors
   /
8617
corpuscular streams  solar emission of particles giving rise to variations
of the geomagnetic field of is discussed  if the stream of particles
is borne in the wake of a shock wave with a velocity of the order
of complete transport of material from the sun to the earth need
not be postulated  the steep nature of the shock front is consistent
with the sudden commencement of magnetic storms
   /
8618
provisional determination of the mean length of the year sunspot
cycle  analysis of available data shows that during the past centuries
the duration of the year cycle has fluctuated between five and eleven
year cycles the mean being year cycles taking the mean duration of
the year cycle as years this corresponds to a range and a mean value
years
   /
8619
solar flare and magnetic storm effects in cosmic ray intensity near
the geomagnetic n pole  phenomena observed during and following the
solar flare of july are discussed  if the observed increase in cosmic
ray intensity was due to charged particles from the sun the trajectories
must have been strongly affected by factors other than the geomagnetic
field
   /
8620
measurement of soil conductivity by the wave tilt method  description
of the experimental arrangement and report of results obtained in
the vicinity of delhi
   /
8621
geomagnetism  this special number commemorates the golden jubilee
of the alibag observatory  the papers presented include the following
the contrast between geomagnetic s and l at huancayo  characteristics
of polar magnetic storms  ionospheric magnetic fields during marked
decreases in cosmic rays  magnetohydrodynamic waves and solar prominences
auroral activity at medium latitudes  solar radiation in the far
ultraviolet and some related geophysical phenomena on the emission
of electric currents from the sun  sunspots and geomagnetic variation
magnetic storms and solar m regions  the dynamo action of the diurnal
atmospheric oscillation  recurrence tendency of geomagnetic activity
during the current sunspot minimum  some remarks on the equatorial
electrojet as revealed by the analysis of solar flare effects  geomagnetic
records at colaba and alibag on days of solar eclipse  some others
are abstracted individually
   /
8622
apparatus for measurement of the intensity of the terrestrial magnetic
field  an adaptation of the device described previously of august
   /
8623
notes on the theory of magnetic storms  a non mathematical account
is given of the model problems and their solutions by which chapman
and ferraro have sought to illustrate some aspects of the theory
of magnetic storms  these problems are here used to develop a qualitative
solution of the motition of an infinite neutral ionized plane
sheet of gas or of a succession of such sheets towards a unidirectional
magnetic field whose intensity decreases as an inverse power of the
distance from an axis to which the sheet is parallel  the gas in
the centre approaches to a minimum distance from the axis and then
recedes again  the gas far to either side moves onward with little
distortion  between these central and outer parts there are two strips
of the sheet whose ions and electrons separate from each other under
the influence of the magnetic field partly because these strips become
much extended and reduced to low density  some charges are deviated
away to infinity others are captured by the field and build up a
westward electric current to which is ascribed the main phase of
a magnetic storms
   /
8624
the relation between the geomagnetic field and range disturbance
in various latitudes  analysis of observations leads to a theory
of the mechanism of magnetic disturbances intermediate between the
classical theory and tht advanced by nikolsky of the true storm time
effect is greatest at the equator an additional effect comprising
instantaneous response to and recovery from the disturbance is greatest
in the auroral zone  the effect on the ionosphere at high latitudes
is briefly considered
   /
8625
assembly of the international union for geodesy and geophysics rome
the text is given of papers most of them in english dealing with
the structure of the atmosphere and especially with research by means
of rockets since
   /
8626
dissociation of oxygen in the upper atmosphere  the content of the
atmosphere at heights between and was determined by measuring the
transmission of solar radiation in the wavelength band from to using
an ultraviolet photon counter in a rocket  at the concentration was
indicating that of the atmospheric oxygen was still undissociated
   /
8627
determination of the true distribution of electron density in the
ionosphere part a survey leads to the conclusion that existing methods
of investigating the electron density distribution are either too
inaccurate or too complicated for routine use
   /
8628
resonance absorption of sunlight in twilight layers  calculations
are made relevant to the determination of the thickness of the atmospheric
sodium layer which appears to be located at a height between
and
   /
8629
new representation of the longitude effect in the ionosphere f layer
the representation is based on a chart with geographic latitude as
abscissa and magnetic latitude as ordinate  on plotting the positions
of existing ionospheric stations the need for stations in certain
regions is demonstrated particularly for stations with south geographic
and north magnetic latitude
   /
8630
simultaneous fluctuations of the f layer ionization at two widely
spaced observation stations  observations of short term variations
of f at graz in austria and at capetown in s africa during january
are compared  correlation factors up to were obtained for values
observed at the same universal time but the correlation decreases
rapidly as the time difference between the measurements increases
the results support the view that the ionizing radiation itself undergoes
short term fluctuations
   /
8631
the ionospheric f layer over india in minimum sunspot year  a summary
of observations made at various stations in india
   /
8632
a singular echo trace observed in ionograms from the kerguelen islands
station  traces have been obtained indicating reflections from a
layer at a height of in summer and in winter corresponding to the
temperature maximum region at the upper boundary of the ozone layer
the results are in agreement with those of major of november
   /
8633
investigation of vertical movements of the f layer  calculations
based on observations of the rate of fading of signals and simultaneous
independent determinations of e layer vertical movements confirm
that the vertical drift velocity of the f layer at morning and evening
is greater than that of the e layer
   /
8634
diurnal variation in auroral activity  an analysis of amateur radio
contacts during the period using vhf transmissions incident obliquely
to the ionized aurora is compared with results obtained by radio
soundings at normal incidence  auroral activity shows a strong maximum
at hours local time with of the total occurrences between and hours
   /
8635
radio astronomy  intended primarily for physicists and astronomers
   /
8636
meteor astronomy  a comprehensive up to date survey indicating the
importance of radio techniques
   /
8637
the sun the solar system vol chapters on the various aspects of the
subject are contributed by acknowledged leaders in the field to produce
a reference book for the specialist and a useful survey for the nonspecialist
   /
8638
the physics of the ionosphere  a collection of papers presented at
the physical society conference held at cambridge england
   /
8639
the response of remote position control x systems with hard spring
nonlinear characteristics to step function and random inputs
   /
8640
the adjustment of control systems for quick transien  response  a
theoretical investigation indicates that for a large class of linear
systems the error due to a transient disturbance is dependent on
only one system parameter the settling time constant and that the
quickest approach to correction is obtained when the system is adjusted
so as to be quasicritically damped  the adoption of quasicritical
damping as a design criterion for stability is recommended
   /
8641
the integral of error squared criterion for servo mechanisms
   /
8642
silicon alloy junction diodes for power supply applications  characteristics
of low power and high power si diodes are presented and various
applications indicated
   /
8643
large storage binary to decimal converter  a digital converter is
described which will handle binary digit numbers with a maximum input
speed of bits
   /
8644
isabel iso status accumulating binaries using extraordinary logic
an improved logical arrangement of a decimal counter based on bistable
elements is described  the advantages over usual methods are described
and the performance of various circuits using this method is given
   /
8645
input and output devices for computers  the following papers were
presented at a symposium held in london  the transport of paper tape
in digital computation  a high speed tape reader  a new cards per
minute card reader  high speed printers
   /
8646
analysing magnetically detected stepper servo motors
   /
8647
a vacuum evaporated random access memory  the basic multiple layer
magnetic film structure described is shown to have valuable properties
in coincident signal switching applications including low magnetic
turn over time and extremely small cell volume
   /
8648
a special purpose analogue digital converter  for use in analysing
tape recordings f of time multiplex telemetry signals  one channel
is analysed at each playback and known transducer nonlinearities
and drifts of gain and level are compensated
   /
8649
thermistors their theory manufacture and applications
   /
8650
line equations for an inhomogeneous line system of cylindrical symmetry
and their application to circuit elements  examples considered include
the calculation of the skin effect of cylindrical wires the frequency
response of disk type and wound capacitors and the impedance of a
sintered ta electrolytic capacitor
   /
8651
the realization of switches for both current directions using junction
transistors  some practical transistor arrangements with and without
diodes are described
   /
8652
static switching  a transistor nor unit output only when all inputs
absent is shown to be suitable as a basic element for building switching
systems
   /
8653
the practical significance for communication technique of the relation
between hilbert transformation and harmonic analysis  conformal mapping
is used to show that the hilbert transformation can be reduced to
a harmonic analysis which would simplify attenuation and phase calculations
practical methods of carrying out the transformation are outlined
   /
8654
vibration of quartz crystal plates  the theory of mindlin of is extended
to the case of crystal plates of nonuniform thickness
   /
8655
design and performance of ultra precise quartz crystal units  techniques
are described for producing crystal resonators with a frequency stability
within about part in and a of  for periods up to month the frequency
stability compares favourably with that of atomic frequency standards
   /
8656
on the electrodes of gt cut crystal units used for the frequency
standards  the physical properties and method of fabrication of electrodes
for crystals used in primary frequency standards are described
a maximum q is obtained when the gold sputtered electrode has a thickness
of advantages of annealing are discussed
   /
8657
temperature compensation of coaxial cavities
   /
8658
increasing the frequency stability of homogeneous cylindrical cavity
resonators  the effect of temperature fluctuations and atmospheric
conditions on the resonator dimensions and the characteristics of
the dielectric are investigated to determine means of minimizing
frequency variations
   /
8659
how to design broadband microwave cavities  design criteria for rhumbatrons
of cylindrical and prismatic form are given with a numerical
example for each type
   /
8660
analysis of all pass networks part general remarks and classification
   /
8661
the theory of the realization of linear quadripole networks with
prescribed effective transfer function in the presence of lossy circuit
elements  summary by the author of the results contained in a more
extensive paper published in chinese
   /
8662
the differences between single and periodic transient processes in
low pass transmission systems  the differences are calculated for
square pulse waveforms and ideal transmission systems corrections
can be made to obtain approximations applicable to practical low
pass networks
   /
8663
synthesis techniques for gain band width optimization in passive
transducers  the technique produces from the idealized gain bandwidth
constraints which ensure matching to a given load a set of functions
specifying the equalizer along the fixed transducer is synthesized
from these functions  examples illustrating the technique are given
   /
8664
an analogue device for problems of filter development  the equipment
described is used for the design of filters from given operating
characteristics  other applications such as filter correction and
filter design for pulse waveforms are outlined
   /
8665
ladder networks with tchebycheff characteristic  ladder networks
without poles are considered with tchebycheff transfer function for
inputs from a generator with finite internal impedance or from ideal
current or voltage generators  design formulae are tabulated
   /
8666
an alternative approach to the realization of network transfer functions
the n path filter  a t me varying network consisting of n parallel
transmission paths each containing input and output modulators is
described and analysed  some practical applications are discussed
in detail and experimental verification is presented
   /
8667
low frequency wave filters employing thermistors  a general review
of thermistor properties and small signal performance is presented
together with results of measurements at very low frequencies and
response curves of simple filter circuits
   /
8668
realization of a comb filter for the detection of pulse signals in
noise  the use of comb filters in radar systems is discussed and
the results obtained on an experimental filter system with up to
seven pass bands are given
   /
8669
the correction of phase distortion in rc networks near cut off frequency
examples of phase correcting networks and optimum design conditions
are given
   /
8670
mechanical filters  english summary
   /
8671
band stop filters  a method of achieving resistance compensation
is bandstop filters is described  performance curves and normalized
component values are calculated for a pole filter
   /
8672
high selectivity with constant phase over the pass band  a relatively
simple frequency inversion process is described for compensation
of phase shifts in filters resulting in a constant output signal
phase
   /
8673
equivalent networks of generic multipoles  a nonreciprocal four terminal
networks can be realised by an equivalent circuit which contains
only one reciprocal three pole element
   /
8674
a new automatic frequency regulation system  brief description of
a system for stabilizing the output of a k band klystron  the error
signal is derived from a phase comparison of a driving signal with
the rectified microwave signal reflected from a dimension modulated
reference cavity  the resonance frequency of the cavity is controlled
by a driven rochelle salt crystal
   /
8675
automatic phase control theory and design  systems with a sinusoidal
reference signal are analysed and the results verified experimentally
   /
8676
variable program triggering source  a transistorized unit for use
with instrumentation cameras is described which generates pulses
at an adjustable constant rate or at a rate which is variable for
a selected period between predetermined initial and final rates
   /
8677
a special trigger circuit  the bistable transistor circuit with common
emitter resistance analysed earlier of has characteristics similar
to those of the schmitt multivibrator circuit  two variations of
the circuit component values are considered corresponding to saturating
and nonsaturating conditions
   /
8678
high speed scalers using tunnel diodes  a simple reliable scaler
with resolving time is described
   /
8679
a cascode trigger circuit using a pnp and npn transistor  a monostable
circuit preceded by a diode pump integrator acts as a frequency dividing
stage
   /
8680
variable ultrasonic water delay line  the unit described produces
a delay variable from and stable w to within the bandwidth is at
   /
8681
the noise figure of several amplifiers in cascade
   /
8682
parametric devices and masers an annotated bibliography  march
   /
8683
parametric diodes in maser phase locked frequency divider  abstract
   /
8684
contribution to the study of parametric amplifiers  an analysis of
parametric amplifier operation in terms of feedback loops  expressions
are derived for the insertion gain noise temperature and bandwidth
of different two and three frequency arrangements which can be generalized
for a four frequency system
   /
8685
the transmission of signals of any form by means of a degenerate
parametric amplifier  formulae are derived for the response of a
degenerate parametric amplifier comprising an antiresonant circuit
with frequency dependent admittance in parallel with a nonlinear
capacitance diode
   /
8686
theory of diode parametric amplification
   /
8687
the reactance type straight amplifier as a low noise preamplifier
stage in the uhf range  the signal and noise response of a cascade
connected amplifier is investigated which consists of a diode reactance
preamplifier see of followed by a conventional triode amplifier
results are given of measurements on an experimental circuit using
a signal frequency of with pumping at
   /
8688
the dc pumped quadrupole amplifier a wave analysis
   /
8689
a contribution to the theory of the transmission of amplitude modulated
frequency modulated or amplitude and frequency modulated carriers
in linear systems part  the standard method of calculating the distortion
of fm signals in linear systems which is based on an asymptotic
series is critically reviewed and its limitations are considered
   /
8690
photovoltaic effect derived from the carnot cycle  an expression
for the maximum power derivable from any photovoltaic device is developed
in terms of the incident light intensity measured in units of
black body radiation
   /
8691
velocity distribution of electrons in a strong electric field  a
method is developed for determination of a nonstationary solution
of the boltzmann equation in the case of strong electric fields
   /
8692
field emission through dielectric layers  a summary is given of the
results of field emission experiments on the absorption of inert
gases on tungsten and a mechanism is described accounting for some
of the phenomena encountered
   /
8693
the spatial and time fluctuation of coulomb energy in the low concentration
impurity conduction
   /
8694
electron scattering in high magnetic field  electrical conductivity
in a strong magnetic field is calculated for the case of scattering
by delta function impurities  collision broadening is neglected and
the scattering by an individual centre is solved exactly rather than
by perturbation theory
   /
8695
microwave breakdown of air in nonuniform electric fields  two cases
are treated theoretically a rectangular microwave cavity and a similar
cavity with a hemispherical boss one of its walls  the theoretical
predictions are compared with breakdown measurements in air
   /
8696
high frequency breakdown of air  kinetic theory is applied to the
ionization breakdown of air surrounding an aerial on a high speed
vehicle  breakdown voltage altitude curves are given for and
   /
8697
electrical and thermal currents in a slightly io ionized gas  a general
solution is given of the boltzmann transfer equation for electrons
under the influence of ac and dc electric fields a magnetic field
and a temperature gradient
   /
8698
nonlinear effects on electron plasma oscillations  a nonlinear term
in the boltzmann equation is considered as a perturbation and the
results are examined to investigate the validity of the linear approximation
   /
8699
forces on charged particles of a plasma in a cavity resonator  two
types of confining force are considered the mathieu force due to
the electric field acting directly on electrons see boot et al  and
the em force resulting from the interaction of the electron current
with the magnetic field component of the em wave
   /
8700
radio frequency forced oscillations in nonuniform plasmas  a theory
of periodic rf oscillations in a plasma is given neglecting electron
ion collisions and temperature variations  small signal approximations
are derived which are applicable to plasma confinement problems
   /
8701
plasma resonance in a radio frequency probe  measurements of the
dc component f the electron current to the rpobe show a resonance
increase at the electron plasma frequency
   /
8702
negative electrical conductivities  the complex electrical hf conductivity
of a plasma in a magnetic field is calculated on the basis of
boltzmanns equation and the occurrence of negative values of the
real part of is discussed
   /
8703
oscillations in a plasma in a weak magnetic fiel  oscillations of
two types were observed in a discharge tube  these are interpreted
as the plasma type oscillation and the cyclotron resonance oscillation
   /
8704
oscillations of an inhomogeneous plasma in a magnetic field  mathematical
analysis of small oscillations of a hot plasma confined by a magnetic
field shows that there are two types of wave a slow drift wave characteristic
of an inhomogeneous plasma and a magneto acoustic wave  if
certain relations obtain the drift current can cause amplification
of the oscillations criteria for an instability of this kind are
derived
   /
8705
transport properties of plasmas in a strong magnetic field
   /
8706
compression waves in a plasma in a static magnetic field
   /
8707
ion charge exchange reactions in oxygen afterglows  measurements
made by a linear accelerator mass spectrometer of the decay of ion
concentration after a pulsed discharge are discussed with reference
to electron loss processes in the upper ionosphere
   /
8708
summarized proceedings of a conference on some aspects of magnetism
september
   /
8709
generation of phonons in high power ferromagnetic resonance experiments
magneto elastic waves are produced by coupling between spin waves
and elastic vibrations
   /
8710
combinational scattering of electro magnetic waves in ferromagnetic
dielectrics  raman type scattering by oscillations of the magnetic
moment is predicted  the extinction coefficient for the scattered
radiation is calculated
   /
8711
the influence of the conductivity of the surrounding medium on the
input impedance of a current loop  using focks solution for the field
of a low frequency current element lying on the surface of a conducting
medium the input impedance of a current loop is calculated by the
method of induced emfs
   /
8712
shielding of transient electromagnetic signals by a thin conducting
sheet  the screening effects of an imperfectly conducting sheet against
the transient field of a vertical magnetic dipole with a ramp function
excitation are investigated
   /
8713
megavolt electronics cherenkov coupler for the production of millimetre
and submillimetre waves  cherenkov radiation at the watt level can
be produced and beamed by passing a high harmonic electron beam through
a mm hole in a large specially shaped teflon cone  the measured radiated
power shows good agreement with theory
   /
8714
field of a charged particle in a moving medium  energy losses of
the charge due to cherenkov radiation and excitation of plasma waves
are determined
   /
8715
wide band absorbers for electromagnetic waves  the construction is
described of shaft type absorbers suitable for metre waves  measurements
of reflection coefficient as a function of frequency and angle of
incidence are discussed and the possibilities of reducing the depth
of the absorber and of extending the absorption range to lower frequencies
are mentioned
   /
8716
the diffraction of electromagnetic waves by a circular cylinder in
a homogeneous half space  a solution is obtained for the distortion
by a cylindrical inhomogeneity below the surface of the earth of
an em field produced by a point source
   /
8717
scattering of electromagnetic waves from an infinitely long magnetized
cylindrical plasma  the magnetically contained plasma is characterized
in terms of its macroscopic dielectric tensor and the scattering
problem is solved analytically  numerical results are given
   /
8718
scattering of radiation by a plasma  more complete analysis than
that given by hershberger of is necessary
   /
8719
on electromagnetic radiation in magneto ionic media  a wave matrix
is defined the zeros of whose determinant are the propagation constants
of the ordinary and the extraordinary plane waves
   /
8720
doppler effect in an electron plasma in a magnetic field  a note
on the complex doppler effect occurring in an anisotropic or gyrotropic
medium
   /
8721
propagation of microwaves through a magnetoplasma and a possible
method for determining the electron velocity distributions  a study
of propagation of circularly polarized waves parallel to the magnetic
field giving special attention to the extraordinary ray
   /
8722
boundary conditions and ohmic losses in conducting wedges
   /
8723
modulation effect corrections for moments of magnetic resonance line
shapes
   /
8724
electromagnetic pressure on a charge moving in a magnetic field
the radiation pressure on an oscillating particle is considerably
greater than that on a free charge  the problem is considered in
a nonlinear approximation and the equations of motion are discussed
   /
8725
spin configurations  a direct and a fourier method are outlined for
determining the configurations of ordered spin arrangements
   /
8726
net electric charges on stars galaxies and neutral elementary particles
   /
8727
the spectrum of the cygnus and cassiopeia radio sources below  the
steerable radio telescope and and the transit radio telescope at
jodrell bank have been used as an interferometer to measure the ratio
of the intensities of the cygnus and cassiopeia radio sources from
to  the ratio remains constant at  results are compared with those
obtained by other workers
   /
8728
the new radio astronomy centre of the university of signey  general
information is given about the mills cross radio telescope which
is to be erected at the new centre
   /
8729
radio detection of the planet saturn  brief report of the detection
of cm radiation from saturn using an x band ruby maser in a modified
dicke type radiometer system installed on an ft paraboloid  a peak
aerial temperature of was obtained indicating an equivalent black
body disk temperature of
   /
8730
observed variations in the amplitude scintillations of the cassiopeia
radio source  observations over a period of four years are analysed
daily variations are presented as functions of solar and sidereal
time ad the effect of the solar cycle is studied
   /
8731
anomalous winter absorption of radio waves  measurements made at
cambridge england of the absorption of cosmic radio noise on a frequency
of show that the average midday absorption in winter is about twice
as great as in summer  an attempt is made to relate this abnormality
to the winter anomaly in absorption of reflected waves  if certain
assumptions are made it can be shown that on the majority of days
in winter the absorbing electrons are largely concentrated at a height
of about km
   /
8732
ionized gas and high energy electrons in the vicinity of the earth
and in the interplanetary space  examination of results obtained
by the three soviet cosmic rockets relating to the van allen belts
the variation of ion concentration with distance from the earth and
the dependence of the trap collector current and the potential of
the container on the electron current at given ion concentrations
are shown graphically
   /
8733
calculations of cosmic ray trajectories near the equator
   /
8734
electrons of the van allen radiation  flux calculations show that
electrons in the radiation belts cannot be produced by neutron decay
from the cosmic ray albedo  the acceleration of trapped electrons
by em fields is briefly discussed  see also of
   /
8735
rapid reduction of cosmic radiation intensity measured in interplanetary
space  simultaneous observations in pioneer v and on the ground demonstrate
that the forbush decrease is of solar origin takes place in
interplanetary space and is not related to the presence of the earth
or its magnetic field
   /
8736
solar cosmic rays and soft radiation observed at kilometres from
earth  a summary of the cosmic ray and soft radiation effects observed
during march april using a space probe and ground observations
   /
8737
observations of solar cosmic rays near the north magnetic pole
   /
8738
comparison of solar cosmic rays injection including and may
   /
8739
observations of solar flare radiation and modulation effects at balloon
altitudes july
   /
8740
propagation of low energy cosmic ray particles associated with solar
flares  the propagation mechanism is examined using data obtained
during the period june may
   /
8741
cosmic ray intensity variations and the interplanetary magnetic field
the characteristics of the variations can be explained in terms of
a dipole type of field generated by current systems in the solar
corona
   /
8742
low energy solar cosmic rays and the geomagnetic storm of may
   /
8743
the effect of the initial phase of a magnetic storm upon the outer
van allen belt  a theoretical study of the motion of a charged particle
trappin a magnetic dipole field and in a compressed dipole field
the latitude shift of the trapped radiation during magnetic storms
is found to be small
   /
8744
experiments on the eleven year changes of cosmic ray intensity using
a space probe  it is shown that the mechanism responsible for the
changes is heliocentric and the region in which the changes occur
is located principally outside the earths orbit
   /
8745
investigation of interplanetary ionized gas high energy electrons
and solar corpuscular radiation by means of three electrode traps
for charge carrying particles installed on the second soviet space
rocket  between and from the earth electron streams of electrons
cm sec and energies were recorded  protons with energies of at heights
owere also noted
   /
8746
development of multiple radiation zones on october  present observations
made at about altitude during a magnetic sotmr using counters carried
on explorer
   /
8747
outer radiation belt and solar proton observations with explorer
during march april  a preliminary summary of observed counting rates
which includes rate time plots for typical passes  some of the fluctuations
in the outer belt during the observation period are referred
to briefly
   /
8748
detection of electrons in the upper atmosphere by the third earth
satellite  electrons of energies were detected by means of two fluorescent
screens covered with thin al foil of different thickness used
in conjunction with photomultipliers  the flux increases sharply
with decreasing energy  at high latitudes the night time energy flux
reaches a few tens of ergs cm sec sterad
   /
8749
penetration of fast charged particles from the outer atmosphere into
the ionosphere  in streams of oscillating particles trapped in the
earths magnetic field the directions of motion will show pronounced
spatial anisotropy due to absorption effects in the lower layers
of the atmosphere
   /
8750
the outer radiation belt and aurorae  space probe observations are
found to be in good agreement with a proposed unsymmetric model for
the outer radiation belt  see also of
   /
8751
correlation of an auroral arc and a subvisible monochromatic arc
with outer zone radiation on november
   /
8752
a southern hemisphere survey of the radiants of sporadic meteors
results are given of a new survey with higher resolution equipment
see of than that used for the earlier survey of weiss  good agreement
is found with the results obtained by hawkins in the northern hemisphere
   /
8753
effect of the solar activity on the earths rotation  a linear relation
is shown to exist between sunspot activity and were cst is atomic
time  this result is discussed in relation to the influence of solar
activity on variations in the speed of rotation of the earth on its
axis
   /
8754
the structure of the electrostatic field in the free atmosphere from
the evidence obtained during international geophysical year investigations
an examination of the spherical capacitor hypothesis with reference
to the variation of the electric po  ential with height and time
of day
   /
8755
measurement of the atmospheric electric field in the free atmosphere
the results of radiosonde measurements up to about height are compared
with measured and calculated field strength data of other authors
   /
8756
geomagnetic storm sudden commencement rise times  if the sudden commencement
of a magnetic storm is interpreted as the impact of a solar
plasma front on the geomagnetic field its rise time usually a few
minutes depends on the different transit times of hydromagnetic waves
propagated to the earths surface from different poin  s on the boundary
of the field
   /
8757
a note on harmonic analysis of geophysical data with special reference
to the analysis of geomagnetic storms  the effect of the earths rotation
on the determination of magnetic disturbance variations ds and dst
is discussed
   /
8758
radio astronomy observations of the second soviet space rocket  a
report of observations of radio signals from the rocket which reached
the moon at min sec on september  signal intensity measurements were
made using an interferometer technique
   /
8759
on mr king heles theory of the effect of the earth oblateness on
the orbit of a close satellite  an examination of the relations between
parameters used by king hele of and the more usual osculating orbital
elements
   /
8760
on the motion of a satellite in an asymmetrical gravitational field
a theory for the inclusion of the effects of tesseral harmonics in
the motion
   /
8761
angular motion of the spin axis of the tiros meteorological satellite
due to magnetic and gravitational torques  the equations of motion
including the two torques have been solved and the calculated and
observed directions of the spin axis are in close agreement
   /
8762
perturbations in classical mechanics  a method similar to quantum
mechanics time dependent perturbation theory is described which might
be useful in the calculation of satellite orbits and plasma stability
   /
8763
us meteorological satellite cameras photograph cloud cover  description
of the tiros satellite and associated tracking and interrogation
equipment see also of and report on its launching and initial orbits
   /
8764
weather radar observations from an earth satellite  a survey of the
problems involved in designing a weather satellite  the use of radar
in the satellite is discussed and also the problem of handling the
data on the ground and in the satellite
   /
8765
a method for measuring temperature directly in the upper atmosphere
with a rocket borne magnetic mass spectrometer  gas temperature is
determined from the variation of the flux of neutral particles entering
the instrument
   /
8766
on the problem of an effective recombination coefficient in the ionosphere
discussion of possible chemical exchange reactions operative
in establishing ion balance in the ionosphere
   /
8767
changes at kokubunji tokyo  a statistical analysis of data recorded
during the period and a study of their relation to ionospheric absorption
atmospheric noise and other geophysical effects
   /
8768
a statistical theory of ionospheric drifts  a statistical study of
the fluctuations in plasma density is used in an attempt to interpret
drift velocities it is assumed that the ionization is transported
by a turbulent flow in the neutral air under the action of the magnetic
field and the dynamo electric field  the application of the theory
to different heights in the ionosphere is examined
   /
8769
observations of sudden ionospheric disturbances  observed phase changes
for reflected waves of frequency are possible due to an increase
in electron density extending to above the e layer maximum  measurements
of the absorption of cosmic noise transmitted through the ionosphere
show that an increase occurs at heights as low as km or even
   /
8770
use of the incoherent scatter technique to obtain ionospheric temperatures
if the ionization above the f peak is in diffusive equilibrium
its density decreases exponentially with height with a scale height
proportional to the temperature of the neutral gas  electron density
profiles obtained by the incoherent scatter method at are consistent
with a temperature of about between and
   /
8771
f region travelling disturbances and sporadic e ionization  a statistical
study shows an association between f region travelling disturbances
and increases in e ionization at sydney  for about one disturbance
in increases by approximately in some min after the appearance of
the disturbance and returns to normal min later
   /
8772
damping coefficient of vibrating electrons  a druyvesteyn distribution
is substituted for the assumed maxwellian distribution in the derivation
of the damping coefficient of vibrating electrons  the consequences
are discussed
   /
8773
formation of the sporadic e layer in the temperate zones  an extension
of work described earlier of to include regions where the gyro frequency
of the ions is less than their collision frequency
   /
8774
further observations of radio stellar scintillation  results are
described which support those of spencer of concerning the elongation
of ionospheric irregularities  the size of the irregularities is
estimated and a change in dimensions with elevation of the radio
source is observed
   /
8775
electron density distribution in the upper ionosphere from rocket
measurements  seven flights between and having maximum heights of
are discussed  the electron distribution above the f layer maximum
agrees well with that given by chapman theory
   /
8776
a variable atmospheric density model from satellite accelerations
an empirical expression is derived which relates atmospheric density
and scale height h to satellite orbital elements and solar rf noise
flux f  from this can be obtained as a function of f height and solar
zenith angle  tables of and are given for and for two values of f
and
   /
8777
the determination of ionospheric electron content from satellite
doppler measurements part method of analysis  theory is given which
is based on measurements of the slopes of the differential doppler
and the doppler curves obtained from observations of the transmission
at and from sputnik  a semi empirical formula is derived for the
total electron content
   /
8778
the determination of ionospheric electron content from satellite
doppler measurements part experimental results  the results of observations
made from september to december are presented  a winter to summer
variation of in total midday electron content was observed  the diurnal
variation showed an increasing content towards evening although the
content below was decreasing  day to day variations correlated well
with during the summer
   /
8779
the electron content and distribution in the ionosphere  addendum
to of
   /
8780
use of logarithmic frequency spacing in ionogram analysis  an improved
method for the reduction of ionograms to electron density profiles
   /
8781
an improved automatic method for measurement of ionospheric absorption
pulses are transmitted at vertical incidence at a rate f one per
second and the mean echo amplitude over an interval of about one
minute is recorded
   /
8782
some characteristics of ionospheric back scatter observed at  an
investigation of the e and f layers by the incoherent back scatter
technique using either vertical or oblique incidence is described
the spectra of radiation scattered from different heights and an
electron density profile from are shown
   /
8783
faraday rotation observations of the electron content of the exosphere
the moon echo observations of various workers are summarized  the
ratios obtained for the ionospheric electron content above to that
below are tabulated
   /
8784
radar lunar investigations at a low geomagnetic latitude  the theory
and results are presented for polarization rotation observations
of pulsed radar transmissions at reflected from the moon  the diurnal
variation of total electron content of the ionosphere is shown
   /
8785
symposium on the exosphere and upper f region  the text is given
of papers presented at the symposium held in washington dc may  some
of the papers are abstracted separately others are listed below
the exosphere and upper f region  structure of the earths exosphere
whistler dispersion and exospheric hydrogen ions  electron densities
to earth radii deduced from nose whistlers  comment on models of
the ionosphere above f  radio wave scattering by an ionized gas in
thermal equilibrium
   /
8786
a sounding rocket measurement of electron densities to kilometres
doppler measurements were made at and  above the f layer peak the
electron density decrease indicates a scale height of at and a linear
gradient in scale height of from to km
   /
8787
radio propagation measurements using the explorer satellite  coherent
signals at and were emitted by the satellite  the results gave electron
densities of about at above the earth  this is higher than expected
and may have been influenced by an intense geomagnetic storm or by
the need to make large corrections
   /
8788
the electron density distribution derived from whistler data and
faraday fading observations  an interpolation law allows satellite
observations to be combined with whistler data
   /
8789
elf electric fields from thunderstorms  from an assumed cloud to
ground discharge model calculations of wide band vertical electric
field variations indicate a small decrease with distance up to a
relation to and a relation beyond km  radiation field spectrum analysis
over the frequency range indicates that below long discharges produce
more energy than short discharges and that intercloud discharges
may produce as much as cloud to ground discharges  conclusions are
supported by experimental evidence
   /
8790
the thunderstorms of september lightning discharges and atmospherics
report on visual observations made at slough and an analysis of records
taken by lightning flash counters at slough and other stations in
the vicinity of the storm
   /
8791
direct measurement of particles producing visible auroras  a large
amount of auroral light is produced by electrons with energies
   /
8792
large scale auroral motions and polar magnetic disturbances part
a polar disturbance at about hours on september  a detailed study
of a particular event suggests that both the westward auroral electrojet
and the eastward auroral motion are produced simultaneously by a
southward electric field the origin of which is discussed  over references
   /
8793
the height and geometry of auroral radio echoes  at jodrell bank
echoes at have been obtained only from regions where the line of
sight is within of perpendicularity to the local magnetic field lines
at a height of about  see also of et al
   /
8794
analysis of smooth type atmospheric waveforms  over traces are analysed
in an attempt to resolve previous conflicting results of and of caton
and pierce  the precise nature of observations necessary for the
accurate analysis and reliable detection of deviations from simple
theory is indicated
   /
8795
guiding of whistlers in a homogeneous medium  the velocity of energy
flow of whistlers as a function of wave normal angles is computed
results differ from the longitudinal value except at very low frequencies
or very small angles
   /
8796
electromagnetic signals from nuclear explosions in outer space  x
rays produced by a nuclear burst in outer space cause polarization
currents in the medium which if distributed anisotropically will
emit em radiation  a rough calculation indicates that a detectable
signal is produced at a range of from a burst of x ray energy equivalent
to ton of high explosive  the signal power varies as the square of
the electron density so this effect may provide a sensitive measure
of the electron density in outer space
   /
8797
bomb excited whistlers  reasons are given for the possible excitation
of whistler modes by c nuclear explosions and characteristics of
the signals to be expected are discussed
   /
8798
audio frequency electromagnetic radiation in the auroral zone  spectrograms
of the energy in the frequency range were recorded in n sweden
during the winter and early summer of  the energy is low during the
day and high at night and the ratio is greatest in the range  no
clear cut correlation with magnetic indices could be found except
during some geomagnetic disturbances  the main contribution to the
energy probably originates in atmospheric noise from thunderstorms
but magnetic fluctuations may be important at lower frequencies
   /
8799
analysing magnetically detected stepper servo motors  digital test
equipment for evaluating the performance of a motor used for digital
analogue conversion is described
   /
8800
recording accuracy in magnetic tape recording  the accuracy is defined
on the basis of information theory and  he capacity of a magnetic
tape communication channel is calculated taking account of signal
noise ratio and undesirable am and fm effects
   /
8801
photovoltaic effect produced in silicon solar cells by x and gamma
rays
   /
8802
on the realization of a highly stable direct current power supply
with a wide range of output voltage the principle of operation of
a stabilized power supply incorporating two feedback loops is described
the properties of the circuit are deduced from transfer functions
   /
8803
designing transistorized voltage regulators  a detailed analysis
of the design of a dc series regulator with temperature compensation
   /
8804
high speed adding system  a new system is described which increases
the adding speed by obtaining the carries of all digits in a one
step operation
   /
8805
a digital computer store with very short read time  each binary cell
is formed by two sets of windings coupled or not coupled by a linear
ferrite  a unit store has been constructed
   /
8806
a parallel arithmetic unit using a saturated transistor fast carry
circuit  an addition time over digits of ns is achieved
   /
8807
multipliers and dividers i ac computers  thermionic valve and transistor
divders and multipliers are described in which the exponential shape
of the small signal characteristic is used to combine a dc and an
ac signal
   /
8808
the differential analyser and its realization in digital form
   /
8809
high speed light output signals from electroluminescent storage systems
the effect of phosphor afterglow pr digit on read out time appears
to limit the number of matrices to about
   /
8810
a compu  er storage matrix using ferromagnetic thin films  details
are given of the construction and performance of a storage system
using the coherent rotational mode of magnetization reversal in thin
films of a newly developed alloy on an substrate
   /
8811
a magnetic core buffer store for use with a card punch or line printer
the store accepts data from a computer and provides a series of parallel
outputs suitable for printer or card punch  square loop magnetic
cores are used and the decoding and parity check circuits are described
   /
8812
ferrite core memory systems with rapid cycle times the normal cycle
time of for square loop ferrite cores is reduced to  a system suitable
for a store of words of digits with a cycle time of is developed
   /
8813
a class of optimal noiseless load h sharing matrix switches  a scheme
for constructing a matrix switch with a reduced number of input wires
is given  see also below
   /
8814
new developments in load sharing matrix switches
   /
8815
the parametron and its application in data processing systems  ferrite
core and diode parametrons are reviewed and applications are discussed
   /
8816
transistorized magnetostrictive delay line stores  two types of storage
system for operation at are described their delay times are and respectively
see also supplement
   /
8817
the assessment of the reliability of magnetic tape for data processing
a method of tape testing based on a theory of the origin of observed
signal drop out distribution permits batch testing and assists in
the design of tape handling systems and in the calculation of reliability
   /
8818
a magnetic read head with output signal independent of tape speed
each head is double consisting of a variable reluctance reading head
and a conventional writing head  one unit comprises eight double
heads and can be used with standard tape in computer output and editing
equipments  the reading head is adequate for normal packing densities
over a wide range of tape speeds down to zero
   /
8819
self resonance of ceramic miniature capacitors  methods of measuring
the resonance frequency are discussed and the characteristics of
various types of miniature ceramic capacitor at frequencies in the
range are investigated  see also of
   /
8820
a review of the present state of networks synthesis  part  comprehensive
review of synthesis methods
   /
8821
two terminal rc networks and theoretically related topics  a derivation
of the properties of the principal minors f successive orders of
the nodal determinant of a lumped linear rc network  see also below
   /
8822
perturbation theory of resonant cavities  a detailed derivation is
given of the perturbation formula for the frequency shift on introducing
a sample of ferrite or dielectric material into a resonant cavity
   /
8823
on the theory of strongly coupled cavity chains
   /
8824
the rutile microwave resonator  the use of a rutile crystal as a
microwave resonant cavity is described  this is of a sm much smaller
size than the equivalent metal walled cavity
   /
8825
measurement of bandwidth of microwave resonator by phase shift of
signal modulation
   /
8826
determining component variation for gradual transition between dissimilar
impedances  the problem is attacked by a recursive method needing
a minimum of numerical precision  the application to an acoustic
absorption system is considered see also
   /
8827
remarks on the additions to kupfmullers transient transient formula
kupfmullers formula for low pass filters is generalized and an analogous
formula valid for all pass delay circuits with optimally flat response
is derived
   /
8828
the performance of filter networks consisting of equal half sections
formulae are given for the open circuit impedance of an n section
network from which the transmission characteristics can be derived
calculations for various simple filters are included
   /
8829
a tuning fork filter  an introduction to the use of a tuning fork
filter as a circuit element and a complete description of a particular
unit its derivation and the correlation between theory and measurement
   /
8830
linear slope delay filters for compression  design considerations
are summarized for filters having linear change of delay time with
frequency over a narrow band
   /
8831
the normalization of electrical integrating and differentiating
circuits
   /
8832
on the switching time of subharmonic oscillators  the time necessary
to change the phase of an idealized subharmonic parametric oscillator
by is calculated for various values of pump power and switching power
   /
8833
qualitative investigation of a new oscillator circuit  analysis of
a triode oscillator circuit with good frequency stability by mathematical
treatment and an analogue differential analyser
   /
8834
transistor beta phase shift oscillator  a new oscillator circuit
is described whose performance is analysed theoretically and confirmed
by experiment
   /
8835
pulse shaping with variable capacitance diodes  small signal and
analysis is carried out for variable capacitance integrating and
differentiating circuits
   /
8836
multiple coincidence circuit  a general purpose transistor coincidence
circuit accepting up to five input signals with three simultaneous
outputs is described  it features a special discriminator which operates
on the leading edge of the input signals or the passage through zero
on the trailing edge the discriminator bias can be varied over a
wide range without affecting the circuit recovery time
   /
8837
high speed counter requiring n carry propagation  the method depends
on forming complements but the need for complementing the entire
register is eliminated
   /
8838
highly accurate phantastron delay circuit  a transistor circuit incorporates
compensating arran  ements to cancel sources of timing error
the final circuit provides a delay of with an accuracy within and
   /
8839
the laws of summation for tilt rise time and overshoot particularly
in amplifier circuits  the time function parameters of pulses applied
to cascade connected quadripoles are calculated  an improved summation
law for the rise time is derived
   /
8840
the representation in pulse form of the noise of amplifiers  the
noise characteristics of pulse amplifiers are derived without reference
to the reference spectrum as a function of the pulse response of
the amplifier
   /
8841
amplifiers with quasi constant gain  various methods are considered
whereby the overall gain of an amplifying system may be held approximately
constant despite variations in the parameters of the amplifying
units incorporated in the system
   /
8842
ultralinear cathode follower  six valves are use in a white follower
circuit to give unity gain an output impedance of and intermodulation
distortion
   /
8843
flux resetting characteristics of full wave magnetic amplifier affected
by the metallic rectifier  quantitative relations between rectifier
and flux resetting characteristics are investigated by a technique
in which the effects of nonlinear forward and reverse characteristics
of the rectifier are separated by means of mechanical synchronous
contacts
   /
8844
a high power transistor magnetic dc t amplifier  the amplifier uses
a transistor chopper two transistor amplifiers and a magnetic amplifier
the circuits described give a high gain high power output and high
input impedance
   /
8845
transistor wide band amplifiers  the design of rc coupled multistage
amplifiers is considered only the earthed emitter configuration is
suitable for this application
   /
8846
atomic hydrogen maser  self sustained emission at the atomic hydrogen
hyperfine transition frequency has been observed  increased interaction
times with the radiation field mean values up to and correspondingly
narrowed resonance widths have been obtained by retaining the atoms
in a storage box with suitable walls  stimulated emission has also
been recorded and the magnetic field independent hyperfine transition
used to observe field dependent zeeman transitions by a double resonance
method
   /
8847
parametric amplifiers  a review of nonlinear reactance circuits amplifier
characteristics are calculated and compared with experimental
results
   /
8848
an analysis of four frequency nonlinear reactance circuits
   /
8849
shock waves in nonlinear transmission lines and their effect on parametric
amplification  the propagation of a periodic signal on a transmission
line with a nonlinearity in the distributed capacitance is examined
the signal is deformed during its propagation and em shock waves
are generated  the subsequent growth and decay of the shock are analysed
   /
8850
a wide band uhf travelling wave variable reactance amplifier
   /
8851
low noise electron beam amplifier
   /
8852
new microwave tube devices fawshmotron using the fast electron waves
   /
8853
negative resistance amplifier design
   /
8854
negative resistance distributed amplifier  operation f the amplifier
is described in terms of iterative sections
   /
8855
the properties and design of ring modulators  treatment on the basis
of quasilinear quadripole theory of experimentally determined characteristics
and design parameters of ring modulators
   /
8856
mechanical modulator uses variable capacitance
   /
8857
the pin modulator an electrically controlled attenuator for mm and
sub mm waves  abstract
   /
8858
explicit form of fm distortion products with white noise modulation
an extension and correction to of medhurst
   /
8859
first order terrestrial ether drift experiment using the mossbauer
radiation  a one way test of the special relativity and contraction
theories is proposed which would obviate the cancellation of first
order terms observed in two way tests
   /
8860
electric polarizability of a short right circular conducting cylinder
calculations to an accuracy of approximately five significant figures
are carried out for cylinders with radius half length ratios of and
the results are applicable to the design of artificial dielectrics
   /
8861
method of solving a class of axially symmetric problems in the theory
of potential and application to the design of electron optical lenses
a class of problems arising in the calculation of es fields with
rotational symmetry is considered  if the systems satisfy certain
conditions they can be treated by a method of successive approximations
which are obtained by solving a plane es problem
   /
8862
a note on the theory of space charge limited currents  the experimental
results of branwood and tredgold of january with are explained by
a simple model in which there are thin layers of uncharged traps
at the surface of the dielectric which are uniformly distributed
in space and of one energy depth the bulk of the material contains
no traps
   /
8863
the role of cold electron emission due to field effect in the maintenance
at the cathode of an electric discharge in a highly rarified gas
the hypothesis of electron emission at the cathode under the influence
of the space charge due to positive ions is proposed and supported
by preliminary experimental results
   /
8864
oscillation caused by electron sheath breakdown  relaxation oscillations
of frequency were investigated by inserting a highly charged probe
into the dark plasma of a hot cathode gas discharge tube
   /
8865
electron energy distributions in plasmas hydrogen  the method given
in part is applied to the study of the mechanism of striation structure
in hydrogen discharges
   /
8866
rotary magnetic polarization in plasmas application to the measurement
of electron density  vol
   /
8867
measurement of the electron density of a plasma in evolution experimental
apparatus  a general description of apparatus for measuring electron
density in the range electrons
   /
8868
investigation of a plasma column continuously fed and subjected to
an electromagnetic field conditions for the existence of non centred
maxwellian solutions equations of density
   /
8869
potential distribution between two plane emitting electrodes part
thermionic engines  all potential distributions can be represented
by a two parameter family of curves the parameters depending on the
electrode temperatures potentials and work functions the computed
results show clearly th relative influence of these quantities on
the potential minimum between the electrodes
   /
8870
equivalence of the critical concentrations in the ising and heisenberg
models of ferromagnetism
   /
8871
ferrimagnetic resonance in three sublattice systems
   /
8872
hodac sets of eigenvectors for volumes of revolution
   /
8873
on the cherenkov effect for a charge moving above an interface  mathematical
analysis relating to the em radiation due to the movement of
c charged particle and a modulated beam of charged particles in the
proximity of a dielectric
   /
8874
on the cherenkov radiation of dipole moments moving along an axial
channel in a dielectric  the radiation field is calculated for a
magnetic and electric dipole moving in a dielectric  if the radius
of the channel then the radiation of the electric dipole moving perpendicularly
to the axis increases by a factor of compared with the radiation
in the dense medium of the dielectric
   /
8875
diffraction of a pulse by a resistive half plane  the two dimensional
diffraction problem acoustic or em in which the incident pulse front
is parallel to the edge of a half plane is solved by assuming dynamic
similarity in the solu  ion  relations between the problem and the
three dimensional problem which arises when a plane pulse is incident
obliquely at the edge of a resistive half plane are discussed
   /
8876
the diffraction of electromagnetic waves  mathematical treatment
of diffraction and scattering at the surface of a conducting circular
cylinder
   /
8877
diffraction of electromagnetic waves at a paraboloidal screen of
finite dimensions axially symmetric fields  theoretical treatment
of diffraction at a thin ideally conducting paraboloidal segment
   /
8878
diffraction by an imperfectly conducting half plane at oblique incidence
the exact solution has been obtained for the problem of a plane
wave incident at an oblique angle on a metallic half plane  the analysis
requires the solution of coupled wiener hopf integral equations for
the electric and magnetic current distributions excited on the surface
of the half plane
   /
8879
diffraction of an electromagnetic plane wave by a metallic sheet
a new generalized technique is developed for the o solution of the
problem of the diffraction of an e polarized plane wave incident
at an oblique angle on an imperfectly conducting half plane  the
solution obtained shows complete agreement with that of senior
   /
8880
aperture fields in the diffraction by a slit  a description of measurements
at using a parallel plate device of the field distribution over
apertures of width and
   /
8881
the various statements of kirchhoffs principle and their application
to the diffraction diagrams of electromagnetic waves  the various
approximation methods based on kirchhoffs principle are applied to
the case of microwave diffraction at a diaphragm and a reflector
disk particularly for oblique incidence  comparisons are made with
experimental results  reflection at mirrors with dimensions of the
order of a few wave lengths is considered with regard to the calculation
of surface utilization and reflection cross sections references
   /
8882
transmission coefficient for a system of parallel slits in a thin
plane screen  an extension of earlier work on the scattering of em
waves to include more than two parallel slits in a perfectly conducting
screen
   /
8883
dielectric constant of a dense electron gas  theoretical investigation
of dispersion and absorption of em waves in a dense electron gas
   /
8884
propagation constants for electromagnetic waves in weakly ionized
dry z air  data are given for dry air at ionospheric temperatures
in the presence of a magnetic field  the magnitude and energy dependence
of the electron collision frequency are also derived
   /
8885
electromagnetic fields of axial symmetry bounded by a cone and a
sphere  the radiation field of a floating magnetic current ring in
a space enclosed by spheres and cones is calculated  this solution
is extended to certain limiting conditions of direct bearing on em
radiation from aerials in free space
   /
8886
some properties of three coupled waves
   /
8887
induced and spontaneous emission in a coherent field  theory developed
in parts dealing with the interaction between the em field in a cavity
resonator and a number of two level molecules is generalized to include
a gaussian spread in the molecular frequency
   /
8888
microwave emission from an optically pumped atomic system  preliminary
results are reported of an experiment in which the microwave emission
at about from an optically pumped cs cell has been directly detected
   /
8889
recording rf spectrometer for nuclear quadrupole zeeman spectra
circuit details are given of semiautomatic apparatus in continuous
operation for recording chlorine resonances in the region
   /
8890
a simple spectrograph for nuclear paramagnetic resonance  description
of modifications to the bloch spectrograph which simplify decoupling
problems
   /
8891
sensitivity of microwave spectrometers using maser techniques  expressions
ar derived for the reduction in the coefficient of minimum detectable
absorption in a microwave waveguide when molecules in an excited
state are added along the waveguide  the application of this principle
to a cavity spectrometer is discussed
   /
8892
atomic hydrogen maser
   /
8893
an instrument for the investigation of interplanetary plasma  a faraday
cup is described for use on a deep probe to measure the density and
the magnitude and direction of the bulk velocity of the positive
ions
   /
8894
amplitude scintillation of radio star at ultra high frequency  observations
of cygnus a at over a month period are described and show short
term and seasonal fluctuations of scintillation rate as well as some
correlation with geomagnetic effects
   /
8895
evidence for the solar corpuscular origin of the decametre wavelength
radiation from jupiter  some correlation was found between and emissions
from jupiter between april and august and the occurrence of geomagnetic
disturbance about nine days earlier  some events were associated
with solar flares
   /
8896
new limits to the diameters of some radio sources  observations using
a base line of have shown that at least seven sources have major
features smaller than three seconds of arc with extremely high surface
brightness
   /
8897
relation between the position and the sense of polarization of solar
radio storms  observations of solar storm centres made with the great
interferometer t nancay at have been related to measurements of polarization
made at nera netherlands at  results show that the radiation
from storm centres in the northern solar hemisphere has a predominantly
right hand polarization and that from the southern left hand polarization
   /
8898
solar bursts of type and their relation to flares  recordings of
bursts made by radiometer and radio spectrograph at freiburg and
other observatories are analysed and their relation to flares observed
in the same period is studied
   /
8899
the radiation belt produced by neutrons leaking out of the atmosphere
of the earth  the composition of the radiation belts is compared
with that expected for a neutron decay source  it seems that the
inner belt is produced only by neutron e decay  in the outer belt
the electrons of energy greater than are probably produced by neutron
decay but those of lower energy probably come froom outside the belt
   /
8900
the solar daily variation of the cosmic radiation world wide neutron
monitor observations during the international geophysical year
   /
8901
effects of short term world wide modulation of the primary cosmic
radiation on observed daily intensity variations
   /
8902
observations of the van allen radiation regions during august and
september
   /
8903
latitude and altitude distribution of geomagnetically trapped protons
a theory is derived for a geometrical injection coefficient of trapped
protrons of cosmic ray origin  calculated distributions resemble
contours obtained experimentally
   /
8904
diffusion of particles in the earths radiation belts  fluctuations
in the geomagnetic field may cause diffusion of particles across
the field  the distribution of particles predicted by a theoretical
study of diffusion is compared with observations using pioneer
   /
8905
geomagnetic fluctuations and the form of the outer zone of the van
allen radiation belt  the suden compression of the geomagnetic field
associated with the initial phase of a magnetic storm causes electrons
to diffuse radially across the geomagnetic field  it is estimated
that a particle at will diffuse a distance in about years
   /
8906
charged particle variations in the outer van allen zone during a
geomagnetic storm  fluctuations in the particle fluxes and local
magnetic field were observed by explorer at km during the geomagnetic
storm of august and found to be correlated  the numbers of low energy
particles decreased and high energy particles increased  the results
are consistent with the theories of dessler an parker of
   /
8907
a study of variations of corpuscular radiation observed by satellite
exsilon near japan  observations in august and september are related
to the electron shell of the argus explosion  the lowering of mirror
points by coulomb scattering and the influence of corpuscular radiation
on the ionosphere are examined
   /
8908
radar methods of measuring the cislunar electron density  six related
techniques for measuring the integrated electron density between
the earth and the moon are discussed  these are based on the determination
of the group retardation suffered by low frequency radar echoes
very high peak power pulse technique or very high equipment stability
cw technique would be required to measure absolute radar range but
this difficulty can be avoided by sending a reference signal with
the measuring signal  the effects of path splitting electron blobs
and lunar surface irregularities are considered
   /
8909
a lunar and planetary echo theory  a lunar radio echo is divided
into a specular component and a lambert scatter component based on
a model of the lunar surface  the theory is compared with experimental
data on the shape and frequency spectrum of reflected pulses
   /
8910
propagation of solar cosmic rays through interplanetary magnetic
field  type polar blackouts are closely associated with solar flares
which are accompanied by type noise outbursts  the delay before the
commencement of the type blackout is about hours for flares in the
east sector of the sun and about hours for flares in the west  the
difference is ascribed to a regular distortion of the outer solar
magnetic field  the commencement of the geomagnetic storm is not
dependent on the solar longitude of the flare
   /
8911
the gross character of the geomagnetic field in the solar wind  the
field may be deformed into a tear drop shape by the interplanetary
pasma  it is emphasized that the asymmetry of the deformed field
ought to be considered in space investigations
   /
8912
note on the geometry of the earth magnetic field useful to faraday
effect experiments  a study of the factor cos sec where and are the
angles between a ray and respectively the earths field and the vertical
   /
8913
audio frequency fluctuations in the geomagnetic field  an examination
of recordings at three locations widely spaced in latitude indicates
that equatorial thunderstorms are the major sources of fluctuations
in the frequency range
   /
8914
geomagnetic observations at halley bay
   /
8915
results of scientific investigations made by soviet sputniks and
cosmic rockets  report presented at a meeting of the american rocket
society washington november
   /
8916
payload design for a lunar satellite  a description of the experiments
planned and the equipment ad methods used in the able vehicle
   /
8917
on geomagnetic observations with the aid of the first soviet cosmic
rocket  the results of the investigation show that the rate at which
the intensity of the magnetic field decreases with e height is greater
than the calculated one  a graph indicates this variation for heights
between km and
   /
8918
osculating elements derived from the modified hansen theory for the
motion of an artificial satellite  musens development of the hansen
theory for the motion of an artificial satellite can also lead to
an expression for the velocity vector and osculating elements as
well as for the gravitational perturbations
   /
8919
an algorithm applicable to numerical integration of orbits in multi
revolution steps
   /
8920
variations in the orbit of the echo satellite  minitrack observations
of the echo satellite show that owing to the suns radiation pressure
the perigee distance and eccentricity of the orbit are varying at
rates which are in good agreement with the theoretical rates  the
observations also lead to a value for atmospheric density at a height
of km
   /
8921
evidence of satellite induced ionization effects between hemispheres
signal enhancement over a mile path is correlated with reflection
from ionization caused by sputnik  this occurred both when the satellite
was in the northern and the southern aurora zones and an explanation
for this is advanced
   /
8922
some studies of bifurcation of the ionospheric f layer into f and
f ionograms recorded at frequent intervals at cambridge in and show
how the f layers develop at sunrise on quiet and disturbed days and
at different seasons
   /
8923
a pre sunrise phenomenon and the presence of negative ions in the
f region of the ionosphere  increases of f layer electron density
which occur about two hours before ground sunrise might be due to
photodetachment of electrons from negative ions
   /
8924
a test of a procedure for easy estimation of representative monthly
electron density profiles for the ionosphere  the profile produced
from the mean of the daily virtual height curves is well within one
standard deviation of the mean of the individual profiles
   /
8925
a study of observed spread f  examination of a large number of ionograms
shows the effect of using different receiver gain settings and reveals
a night f phenomenon  the degree of spreading varies with magnetic
dip
   /
8926
the possible importance of nitric oxide formation during polar cap
ionospheric absorption events  polar cap absorption is attributed
to an increase in abundance of the probable ionizable constituent
of the d region  a possible mechanism depends on the production of
n atoms by cosmic ray particles  the ionization of must occur above
alternative theories of polar cap absorption involving photodetachment
of electrons from ions require the ionization to be much lower
   /
8927
ionospheric disturbances following a solar flarethe perturbations
of and following the great flare of september are shown on polar
projection maps  the charts differ significantly from those of obayashi
and hakura of for the same period  the disturbance during the geomagnetic
storm forms an elliptic ring with the e concentrated in crescent
shaped areas inside it  the results are discussed theoretically
   /
8928
back scatter experiments during the total eclipse of october  th
eclipse perturbations could not be clearly separated from those due
to other disturbances
   /
8929
eclipse effects on the f layer at sunrise  an analysis of electron
density variations during the solar eclipse of september which took
place near sunrise in maryland usa  z about of the ionizing radiation
may have originated outside the solar disk
   /
8930
eclipse effects on the flayer observed at cambridge on june  variations
of during the solar eclipse of june are discussed  about of the ionizing
radiation may have originated outside the solar disk
   /
8931
a connexion between p and the f region  the diurnal variation of
geomagnetic micropulsations of the type near the equator is inversely
related to the diurnal variation of the true electron density at
km  the interpretation of this result is tht the source of p oscillations
lies above the ionosphere
   /
8932
determination of electron density in the ionosphere from the rotation
of the plane of polarization of radio waves emitted by a rocket
rocket investigations on the august at heights up to km at frequencies
of and are rp reported  a graph shows the variation of electron density
with altitude
   /
8933
reducing interference in ionospheric sounding  a special circuit
is described for separating the desired pulses from interfering cw
signals
   /
8934
solar corpuscular radiation and polar ionospheric disturbances  typical
examples of abnormal absorption at high latitudes are described and
compared for low energy cosmic ray events geomagnetic storms and
combined cosmic ray events and storms the energy spectra of the solar
pr particles involved are discussed and summarized
   /
8935
the ionosphere over halley bay  the ionospheric phenomena observed
at halley bay are briefly described and the influence of the weddell
sea magnetic dip anomaly stressed  some ionization is generated
in the lower ionosphere by solar photoionization processes at solar
zenith angles up to about  the f layer variations appear to be dominated
by movements of ionization which can also be seen near the maximum
of the f layer  ionization drift velocities in the e region reverse
with season and are greater in winter than in summer other features
of drift and absorption are generally consistent with those expected
   /
8936
ionospheric drifts determined from radio star scintillation observations
spaced receiver observations have been made at halley bay and
ionospheric velocities deduced from the motion of the diffraction
pattern over the ground  both the time of midnight reversal and the
drift speed correlate well with evans measurements of motions of
auroral forms
   /
8937
spiral patterns in geophysics  the spiral patterns found in recent
analyses of magnetic and ionospheric data are incompatible with stormer
theory
   /
8938
latitude distribution and seasonal variation of aurora over the british
isles during and
   /
8939
on the origin of radar echoes associated with auroral activity  observations
at kiruna sweden at indicate that the predominant echo mechanism
is closely connected with ionized and often invisible auroral forms
which are directed along the geomagnetic field
   /
8940
systematic movements of aurorae at halley bay  all sky photographs
have been used to determine the movement of individual auroral features
on the assumption of a fixed height of occurrence
   /
8941
auroral results from halley bay during the international geophysical
year
   /
8942
auroral radio echoes at halley bay  the echoes observed are shown
to fit closely the case of specular reflection from columns of ionization
aligned along the local magnetic field at a height of about km
   /
8943
the effect of proton gyration in the outer atmosphere represented
on the dispersion curve of whistler  whistlers observed at kyoto
geomagnetic latitude reach a height of km  the dispersion of a very
pure whistler at kyoto in was measured from to less than and compared
with that calculated using the complete dispersion law  it is concluded
that the dispersion was influenced by the effect of proton gyration
   /
8944
propagation of whistlers to polar latitudes  an analysis of observation
made in new zealand north america and antarctica of the dispersion
characteristics of a whistler associated with a depression which
occurred in the area of the tasman sea at on april  reception to
this whistler in the antarctic would imply a final stage of propagation
under the ionosphere for more than km
   /
8945
observations of earth ionosphere cavity resonances
   /
8946
the stabilization of control systems with backlash using a high frequency
on off loop  an auxiliary loop is used to drive the motor across
backlash in the gear whenever the motor and load tend to separate
   /
8947
the effect of an additional nonlinearity on the performance of torque
limited con  rol systems subjected to random inputs  the addition
of a nonlinear error detector gives an improved response
   /
8948
a calculation of switching functions as a means of minimizing error
in an on off control system  adaptive switching functions are discussed
and the principles illustrated on a mathematical model of an ideal
servomechanism
   /
8949
extension of the dual input describing function technique to systems
containing reactive nonlinearity  an extension of the work of kochenburger
and of west et al  enabling the nonlinear coefficient to be associated
with any term in the differential equation
   /
8950
the stabilization of direct voltage supplies  a functional diagram
is proposed by studying the control and stabilization of a dc supply
system under load and no load conditions
   /
8951
designing solid state static power relays  the performance and design
of relay circuits using si controlled rectifiers is considered
   /
8952
construction of a thermionic energy converter  discussion of design
data for a c vapour type of energy converter  the construction and
testing odevelopment of japanese digital computers  parametron and
transistor circuit techniques widely used in japanese computers are
described and the general characteristics of types of computer are
tabulated
   /
8953
a vlf function generator  an electromechanical device producing a
readily variable function is described
   /
8954
microminiaturizatio  illustrated review of current achievements
   /
8955
calculation of the parameters of a quadripole by means of signal
flow graphs
   /
8956
a modified synthesis procedure for two terminal pair networks  a
general theorem given previously of is extended for a particular
case of a network with one pair of terminals open circuited
   /
8957
design of optimum filters  the design of low pass filters using easily
computed rational functions instead of elliptic functions permits
more accurate location of the poles of the transfer function when
the number of poles exceeds four and computation is less laborious
   /
8958
general principles of polyphase vacuum tube oscillator
   /
8959
synchronization of frequency modulated free running oscillators investigated
by servomechanism methods  application of a servo system to
the control of a free running oscillator  a method is described for
determining the frequency response of the closed loop from measurements
of open loop characteristics  quadripole correctors for improving
the response will also widen the frequency range over which control
may be exercised
   /
8960
pass band and selective af amplification f of a hf oscillator  the
bandwidth of a hf oscillator has been investigated theoretically
and experimentally by studying the behaviour of the oscillator as
a selective af amplifier
   /
8961
analysis of a semiconductor multivibrator with emitter capacitance
an analysis of an emitter coupled transistor multivibrator showing
the effect of emitter capacitance in increasing the thermal stability
of the pulse duration parameters
   /
8962
fast transistorized time to pulse height converter  a converter of
simple design is described having a timebase and giving a resolution
of using conventional scintillation counters  it was used to analyse
particle beams by time of flight measurements
   /
8963
a reversible dekatron circuit  a description of the unit with discussion
of its limitations
   /
8964
regenerative fractional frequency generators  a self starting regenerative
frequency divider circuit is described which has the advantages
of simplicity and of lock in stability over a i wide range of frequencies
an approximate analysis is given which shows the dependence of
performance on diode characteristics and transistor input impedance
   /
8965
simple logarithmic dc amplifier  a simple double triode amplifier
is described  it has an accuracy within for input voltages from to
and is easily adjusted for differing valve characteristics
   /
8966
the bootstrap amplifier  an analysis of a rc coupled pentode amplifier
with the anode decoupling capacitor returned to the cathode of a
cathode follower  the effects of the coupling and decoupling capacitors
on the low frequency response characteristics are calculated
   /
8967
analysis of half wave magnetic amplifier circuits with ac bias voltage
detailed analysis with special reference to the elimination of the
rectifier from the control circuit of rameys half wave magnetic amplifier
   /
8968
a nonlinear effect in transistor amplifiers with feedback  the nonlinear
effect described in an earlier paper of is analysed  it is attributed
to to variations of carrier transit time with transistor collector
voltage
   /
8969
use of slow molecules in molecular generators  methods of improving
the absolute frequency stability of a beam type maser are considered
based on the use of molecular beams with mean velocities much less
than the thermal velocity at room temperature  three techniques are
described removal of high velocity molecules from the beam retardation
of the molecules by an external field reduction of the temperature
of the molecular beam
   /
8970
systems applications of solid state masers  progress in solid state
maser technique is surveyed  operating principles and circuit design
are outlined
   /
8971
the optimum line width for a reflection cavity maser  extension of
previous work of to show that the maximum gain bandwidth product
is achieved
   /
8972
electrically tunable travelling wave masers at l and s bands  tuning
ranges of and greater have been obtained by varying only the applied
magnetic field and the pump frequency  test data are given
   /
8973
coupled cavity travelling wave parametric amplifiers analysis  detailed
information is given on operating characteristics of a travelling
wave circuit consisting of a chain of inductivity coupled cavities
loaded by diodes in the capacitive region  calculations show that
unilateral gains of over relatively wide bandwidths are attainable
with diodes
   /
8974
coupled cavity travelling wave parametric amplifiers part experiments
gain bandwidth products of with a bandwidth have been obtained at
s band frequencies using commercially available diodes  noise temperatures
of have been measured  methods for achieving short circuit stability
are investigated  these n include the use of ferrite loaded coupling
irises and of upper frequency pass bands
   /
8975
gain of a travelling wave parametric amplifier using nonlinear lossy
capacitors  an analysis of a travelling wave parametric amplifier
considering reverse biased diodes as lossy capacitors
   /
8976
aspects on wide band parametric travelling wave amplifiers  methods
are described for calculating amplification bandwidth phase conditions
and noise figure
   /
8977
gain optimization in low frequency parametric up converters by multi
diode operation  a method is proposed for optimizing the gain of
an up converter using more than one variable capacitance diode at
the same point  results of a first order analysis made with two diodes
are given
   /
8978
idler noise in parametric amplifiers
   /
8979
esaki diode amplifiers at and  stable gains of up to at and at have
been obtained with the diode in a cylindrical reflection cavity which
has been described earlier of january trambarulo
   /
8980
criterion of uniqueness for the solutions of maxwells equations
   /
8981
the dirac electron in rectilinear fields  diracs equations for an
electron in a rectilinear field are first reduced to a single equation
of simple form suitable for the solution of problems  an explicit
solution is then obtained for an electron in a constant electric
field
   /
8982
variational treatment of warm electrons in nonpolar crystals  deviations
from ohms law in nonpolar crystals are treated by the variational
method for the case of weak fields  the second order term in the
electrical conductivity is calculated
   /
8983
effect of random inhomogeneities on electrical and galvanomagnetic
measurements  a theoretical treatment is given in which the scale
of inhomogeneities is supposed small compared with the specimen size
but large compared with the mean free path and debye length  comparison
with exactly soluble cases shows the derived formulae to e valid
for sizable fluctuations
   /
8984
the validity f the concept of specific surface resistance and its
measurement  extension of earlier work by lacoste of to show tht
the criterion for surface conduction is independent of the electrode
system configuration  the influence of the configuration on accuracy
of measurement is considered
   /
8985
steady state distribution function in dilute electron gases  the
effects determining the distribution function of optically liberated
carriers are investigated  for a simple model semiconductor significant
deviations from the boltzmann distribution are possible at temperatures
below a few degrees kelvin
   /
8986
on the possible influence of electron interaction on the reflectivity
of metals  continuation of the work by benthem and kronig on the
influence of electron viscosity on the absorption factor of metals
in the infrared region
   /
8987
sustained localized pulsed micro wave discharge in air  details are
given of a small localized discharge obtained in low pressure air
using a pulsed x band radar transmitter as the microwave source
   /
8988
transmission of slow electrons through thin film
   /
8989
investigation of a plasma column continuously fed and subjected to
a magnetic field first order approximations for the diffusion velocities
manifestation of a frontier zone
   /
8990
free path formulae for the coefficient of diffusion d and velocity
of drift of ions and electrons in gases
   /
8991
ion resonance in a multicomponent plasma  interactions between different
types of ion produce additional resonances
   /
8992
oscillations of an electron ion plasma  investigation of the spectrum
of longitudinal oscillations for the case of low temperature fermi
distribution and high temperature maxwell distribution  for low values
o the wave vector the dispersion equation has two branches corresponding
to optical and acoustic modes
   /
8993
direct exchange in ferromagnets  evaluation for all internuclear
spacings of the direct exchange integral occurring in the heisenberg
theory of ferromagnetism leads to the conclusion that direct exchange
is not responsible for ferromagnetism in ferromagnetic metals
   /
8994
collective excitations of electrons in degenerate bands part spin
waves in stoners model of ferromagnetism  spin waves in the collective
electron model of ferromagnetism are derived
   /
8995
anisotropic superexchange interaction and weak ferromagnetism  a
theory is developed by extending the anderson theory of super exchange
to include spin orbit coupling
   /
8996
determining the dielectric permittivity and magnetic permeability
tensors of a medium  an analytical note on the separation of gyroelectric
and gyromagnetic effects
   /
8997
transition radiation in a waveguide  investigation of the radiation
which arises in a waveguide by the passage of a charged particle
through the boundary between two media  at ultrarelativistic charge
velocities the radiation is mainly in the forward direction and its
magnitude is proportional to the particle energy  formulae for the
total energy of the radiation and its spectral distribution are derived
   /
8998
some absorbent materials at uhf the characteristics of two types
of absorbent material are described a plastic or rubber sheet impregnated
with carbon powder applicable over a wide band of frequencies and
a similar material thick impregnated with carbonyl iron or carbon
power and backed with a thin metallic sheet applicable over a narrow
band
   /
8999
contribution to the study of diffraction of electromagnetic waves
by spheres  a thesis describing theoretical and experimental methods
of obtaining the diffraction field of both a single sphere and a
pair of spheres  for a report of experimental apparatus see of
   /
9000
diffraction of a plane electromagnetic wave by cylinders with anisotropic
conductivity
   /
9001
a study of surface roughness and its effect on the back scattering
cross section of spheres  experimental data obtained by measuring
the back scattering cross section of a large rough sphere at three
frequencies in the s x and k bands are presented  even for a sphere
whose depth of roughness is as large as the measured change in cross
section is no more than this is in good agreement with the theoretical
prediction
   /
9002
line breadths in the ammonia spectrum  measurements have been made
of the inversion spectrum  from the results a value of per mm at
has been obtained
   /
9003
line structure in paramagnetic resonance and direct measurement of
the moments
   /
9004
the influence of modulation on the recording of resonance phenomena
curves based on the standard resonance curve of a simple harmonic
oscillator are given as an aid to the construction of spectrographs
and the analysis of recorded spectra
   /
9005
nonlinear effects of crystalline anisotropy on ferrimagnetic resonance
analysis shows that the magnetic resonance frequency depends quadratically
upon the precession amplitude to lowest order this can cause a
foldover of the resonance line
   /
9006
cross relaxation in dilute paramagnetic systems
   /
9007
the direction dependence of magnetostriction  tensor methods are
used to describe the lattice distortion caused by magnetostriction
for similar calculations of the direction dependence of crystal energy
see
   /
9008
proceedings of the international congress on many particle problems
the text is given of invited papers read at a conference held in
utrecht june
   /
9009
ion size effect and mechanism of electrolytic rectification  previous
theories of electrolytic rectification are shown to be inadequate
extensive experimental work is presented which shows the importance
of the size of the cation in solution and the existence of an extremely
thin surface barrier of height about
   /
9010
note on the transference of angular momentum within the galaxy through
the agency of a magnetic field
   /
9011
magnetic field of jupiter  a review of theoretical and experimental
evidence in support of the hypothesis of an ionosphere and magnetic
field associated with jupiter
   /
9012
the correlation of radio source scintillation in the southern and
northern hemispheres  observations of radio source scintillation
made simultaneously at halley bay and jodrell bank show a significant
correlation  this is relevant to theories with auroral activity
   /
9013
the magnetic storm time variation of radio star scintillations and
auroral radio echoes  the variations of scintillation rate and auroral
echo incidence during periods following magnetic sudden commencements
resemble the variation of magnetic k index
   /
9014
a determination of the principal plane of the galaxy  data from the
leiden and sydney surveys of the milky way have been used to determine
the position of the plane of the neutral hydrogen layer which is
found to be exceedingly flat over the galaxy within kiloparsecs from
the centre
   /
9015
radio data relevant to the choice of a galactic coordinate system
because of the large scale association found between sources of the
radio continuum and the distribution of the cm hydrogen line radiation
the coordinate system may be defined by the principal plane and by
a centre situated in sagittarius a
   /
9016
some statistics of solar radio bursts at sunspot maximum  bursts
at and are mainly of spectral type and occur more frequently than
bursts at and which are of a greater intensity and of spectral type
   /
9017
on the identification of extragalactic radio sources  radio data
from sydney and cambridge have been compared with a catalogue of
galaxies in a limited region of the sky  possible identifications
of rf sources with galaxies have been made and with clusters of galaxies
   /
9018
solar modulation of primary cosmic rays  the observed solar modulation
of cosmic rays may be explained assuming the existence of two solar
magnetic fields one uniform and the other irregular and two solar
streams one continuously ejected and the other produced by solar
eruptions
   /
9019
sou  hern hemisphere meteor shower activity in july and august  observations
for are described and measurements of the radiant coordinates
and echo rates for the aquarids and three other minor showers are
summarized
   /
9020
meteor height distributions and the fragmentation hypothesis  a comparative
study of fragmentation amongst bright and faint meteors
   /
9021
volume density of radio echoes from meteor trails
   /
9022
the importance of initial trail radius on the apparent height and
number distributions of meteor echoes  fewer echoes from faint meteors
of magnitude are observed at than at  this effect is attributed to
an attenuation in echo amplitude due to the large initial radii of
the ionized trails
   /
9023
the determination of the incident flux of radio meteors  simple formulae
are derived which allow the incident flux of shower meteors to be
deduced from the observed rate after allowing for the aerial characteristics
and the geometry of reflection  the limitations of the method
are discussed
   /
9024
the interaction of the terrestrial magnetic field with the solar
corpuscular radiation  the shape of the cavity between the earth
and a neutral solar stream differs by only from a hemisphere of radius
earth radii on the incident side but is elongated on the other side
to a distance of the order of earth radii  the cavity is idented
at the polar latitudes where the current layer reverses
   /
9025
the cause of magnetic storms and bays  circulating currents set up
around regions of proton and electron precipitation by the hall effect
are suggested as the cause of magnetic bays and storms
   /
9026
daytime enhancement of the amplitude of geomagnetic sudden impulses
in the equatorial region  igy data from equatorial stations provide
some evidence that sudden impulses and sudden commencements are caused
by similar mechanisms
   /
9027
evidence of quasi perpendicular propagation of hydromagnetic waves
caused by nuclear explosions over johnston island
   /
9028
verification of earths pear shape gravitational harmonic  errors
in the predictions of the orbit of the transit ib satellite are accounted
for by a third order gravitational harmonic previously evaluated
by okeefe et al
   /
9029
the relation of the satellite ionization phenomenon to the radiation
belts  during march and april when telemetry transmissions from explorer
were monitored the strongest enhancements of wwv signals received
at columbus ohio occurred at times of peak counting rate aboard the
satellite  many of these events were accompanied by a partial or
complete fade out of the satellite signal  see also of
   /
9030
some characteristics of the signal received from  the correlation
between scintillation effects and the occurrence of spread f is noted
and skip distance phenomena a observed in ordinary and extra ordinary
wave propagation are discussed
   /
9031
electromagnetic waves and satellites echoes from ionized trails of
satellites at high frequency  ionized trails from and were detected
at using a pulsed transmitter and a receiver with bandwidth  the
results are discussed and the most favourable conditions for detecting
echoes are examined
   /
9032
on the lunar semidiurnal variation of the d and f layers  the variations
at freiburg genoa and leopoldville are compared with those obtained
by other authors  magnetic dip rather than geomagnetic latitude controls
the variation in the f layer  the amplitude of the variation is plotted
against magnetic dip
   /
9033
on some disturbances in the e region  a discussion of e layer stratifications
and complex phenomena observed on ionograms in relation to
computed electron distributions  the passage of transient cusps on
curves if o found to be due to redistribution of e le layer ionization
factors influencing the identification of e layer penetration frequencies
are discussed
   /
9034
investigation of the transparency of the ionospheric e layer  report
of an analysis of world wide observations of diurnal changes in e
results are discussed and tabulated in the form of an index called
the degree of occultation which is defined as the ratio where is
the blanketing frequency for reflections from the f layer and the
highest frequency at which reflections from the e layer are detected
   /
9035
mechanism of ionization of the sporadic e layer  observations made
using a technique based on that introduced by naketa et al and have
shown that the height of e varies in a systematic way during the
lifetime of an e event if the intensity of ionization increases the
layer height decreases
   /
9036
horizontal drift in the ionosphere over delhi  the drift was measured
using spaced receiver techniques and both e and f layer reflections
are analysed for the period april march  velocity histograms of the
ns and ew components and plots of the seasonal variations in velocity
and drift directions are given
   /
9037
on the observational results of at yamagawa  measurements of and
made between august and february showed the presence of the winter
anomaly in absorption at night
   /
9038
on the d electron and ion density distributions from the lower up
to the uppermost pz part of the f region  the thesis that the main
ionizing radiations in the f region are the helium resonance lines
at and the lyma continuum leads to the following results the calculated
electron density distribution in the lower f region is in good agreement
with experimental electron density profiles the observed and calculated
relative abundances of the ions and are not in good agreement unless
their charge exchange reactions are assumed to be a few orders of
magnitude slower than expected on simple theory and if a scale height
gradient of is assumed then the calculated and experimental electron
densities are in agreement up to above the f region maximum
   /
9039
on the f region of the ionosphere  a continuation of earlier work
of to include calculations of diurnal variations of production rate
for march using the attachment coefficient model suggested by ratcliffe
et al  results are compared with those for january given in the earlier
paper and are found to be consistent with bradburys hypothesis for
the formation of th f layer
   /
9040
world wide da  ly var  ations in the height of th  maximum electron
density in the ionospheric f layer  the heights given by the method
of shimazaki of which related and the height of a parabolic f layer
have been compared with the more correct values derived from corresponding
profiles  the agreement between the two methods is quite good
during the night in middle and low latitudes but during the day in
these latitudes and for all hours at high latitudes shimazakis relation
overestimates the height by about km
   /
9041
investigation of the formation of the ionospheric f layer at leopoldville
binza  data for the period are analysed  photo ionization and
drift are insufficient to explain the variations of maximum electron
density additional ionization due to corpuscles accelerated in a
region near the earth is suggested
   /
9042
bifurcation and other irregularities of the ionospheric f layer
splitting is considered to occur when the excess of energy of each
ionizing photon over the ionizing potential is transformed into heat
on account of the quasi neutrality the rarefaction of the gas at
the maximum of ionization can create a small secondary minimum of
electron density which separates the f layer into f  this secondary
minimum of electron density appears just at the maximum of electron
production
   /
9043
effects of diffusion of electrons near the magnetic equator  if it
is assumed that ionization in the f layer is produced according to
chapmans law then as the magnetic equator is approached the rate
of increase in ionization wil exceed any decrease due to the effects
of vertical diffusion described by schmerling of the hypothesis of
vertical diffusion does not therefore account for the geomagnetic
anomaly
   /
9044
the geomorphology of spread f  the occurrence of spread f is roughly
symmetrical about the geomagnetic equator and is greatest in the
equatorial and auroral regions  it occurs mainly during the night
and is greatest in winter in the auroral region and at equinox in
the equatorial region
   /
9045
the belt of equatorial spread f  igy data are used to discuss the
morphology of nocturnal spread f incidence in the equatorial belt
and this is compared with the morphology of the post sunset increase
of f layer virtual height  between magnetic latitudes the incidence
of spread f is high but decreases during periods of magnetic disturbance
existing theories are inadequate to explain the observations
   /
9046
muf factor and solar activity  an analysis of ionospheric data for
delhi and ahmedabad indicates that a linear relation  exists between
and the sunspot number for both places
   /
9047
hydromagnetic waves in the ionosphere  the results of numerical integration
of the hydromagnetic wave equations in the ionosphere are presented
earlier estimates of ionospheric heating by hydromagnetic waves
are confirmed
   /
9048
electron densities in the f region of the ionosphere from rocket
measurements  the recording and analysis of faraday rotation and
range error measurements on radio waves from long range military and
satellite launching rockets are described  corrections for horizontal
gradients and refraction are included  the results from seven launchings
show that the vertical electron density gradient is greatest near
sunrise and lowest after sunset suggesting a time lag before diffusive
equilibrium is reached
   /
9049
the d layers and the absorption of radio waves  the possibility of
separating absorption at different levels in the lower ionosphere
is discussed theoretically with experimental examples
   /
9050
the sunrise in the ionosphere and its repercussions on long wave
propagation  the basic data are the records made at zurich of the
variations in number and direction of arrival of atmospherics at
a frequency of  the sudden fall in number of received atmospherics
near dawn is attributed to the sunrise at a height of at a point
on the wave trajectory  the height of the ozone layer is found to
be km  the transitory nose effect in recordings of atmospherics is
attributed to the transition from d layer to e layer propagation
   /
9051
physical parameters of the atmospheric escape layer  the height of
the atmospheric escape layer is approximately in the daytime dropping
to at night  the temperature of the layer is too low to cause the
dissipation of helium from the atmosphere ad it is suggested that
this process occurs during solar disturbances
   /
9052
adaptation of the radiosonde for direct measurement of radio refractive
index  the sytem described is based on standard meteorological sensing
devices and provides an accuracy sufficient for many radio propagation
applications
   /
9053
on the magnetic time dependence of the auroral zone currents  the
geomagnetic time for the evening passage of the geomagnetic component
h through the zero disturbance level was measured at kiruna and college
on days  a time difference of min was found only part of which can
be explained by means of higher spherical harmonic terms of the geomagnetic
field
   /
9054
a dynamo theory f the aurora and magnetic disturbance  a model of
the aurora is examined in which a slab of ionized air exists parallel
to the geomagnetic field  a wind of neutral molecules causes movement
of the aurora and certain features of auroral and magnetic disturbances
are explained
   /
9055
radiation from protons of auroral energy in the vicinity of the earth
cyclotron radiation of protons in the earths magnetic field could
be one source of dawn chorus
   /
9056
choice of a parameter characterizing radio whistlers  the dispersion
d is proposed as a character figure for whistler  it is also proposed
that as long whistlers have a dispersion which is dependent on frequency
the frequency should be stated zero frequency is considered optimum
for this purpose
   /
9057
travelling wave amplification of whistlers  theory of the travelling
wave tube is applied to af waves in the ionosphere to explain the
generation of whistlers
   /
9058
auroral noise at hf  observations made with fixed frequency back
scatter equipment and riometers are discussed
   /
9059
on the theory of amplitude distribution of impulsive random noise
and its application to the atmospheric noise  atmospheric noise is
considered to be a superposition of sources of independent randomly
occurring poisson noise wave packets  theoretical amplitude distributions
from both discrete and continuous spatial distributions of sources
are compared with actual noise measurements with considerable agreement
   /
9060
physics of the upper atmosphere
   /
9061
instrumentation wide band magnetic tape recording  the development
of a recorder with a bandwidth from dc to is described
   /
9062
the mechanical considerations of magnetic recording heads  manufacturing
problems associated with multitrack heads are discussed in relation
to the effects of mechanical variations on head performance  performance
criteria are listed
   /
9063
some engineering aspects of magnetic tape system design  a system
is described for the evaluation o random and transient effects in
terms of specific measurements on waveforms generated by standard
tapes rather than in terms of dimensional tolerances
   /
9064
a fast start stop machine for handling magnetic tape  the wide tape
is handled at a speed of with start stop times of referred to of
the final speed  the tape loop length is controlled by phototransistors
driving an error correcting servomechanism
   /
9065
the development of a high performance tape handler  magnetic tape
wide is handled completely out of contact at by means of vacuum techniques
start stop and reverse times are better than
   /
9066
stabilized voltage supplies using transistors  two completely transistorized
circuits producing from a dc supply
   /
9067
reverse characteristics with surface breakdown of silicon psn rectifiers
the influence of surface recombination on the reverse and breakdown
characteristics is investigated  measurements were made on si rectifiers
with weakly doped diffusion region which had been exposed to dry
nitrogen and oxygen with or without ozone for different lengths of
time with or without heat treatment  for measurements in moist gases
   /
9068
stabilization of a magnetic field by means of a galvanometer photocell
assembly  note on the application of a galvanometer amplifier system
of for magnetic field stabilization
   /
9069
computer generated displays  a survey of methods  and techniques
in the presentation of computer outputs  references
   /
9070
magnetic film memory design  a storage system for ten bit words has
been operated successfully in the destructive mode with a minimum
cycle time of
   /
9071
high density digital magnetic recording techniques
   /
9072
the simulation of neutral elements y electrical networks based on
multi aperture magnetic cores  the basic operations of multilevel
storage gating controlling threshold level and summation are common
to many simulating networks and can be attained by use of multi aperture
magnetic cores
   /
9073
new storage systems based on the magnetization of three dimensional
elements  three systems are described two are diode controlled circuits
for switching magnetic storage devices and the third biax is a multi
aperture ferrite element using the principle of flux interference
see also
   /
9074
nonstationary parametrons
   /
9075
a computer subsystem using kilomegacycle subharmonic oscillators
a phase locked oscillator is described which operates at and has
a logical operation time
   /
9076
frequency division by carrier storage
   /
9077
computer memories a survey of the state of the art
   /
9078
a survey of tunnel diode digital techniques
   /
9079
calculated waveforms for tunnel diode locked pair  the phase locked
pair functions as a computer element in a similar manner to that
of a phase locked harmonic oscillator and also requires a three phase
power supply  its main advantages are high gain and high transition
speed
   /
9080
the negative resistance concept in modern electronics  a survey with
particular reference to the operation of semiconductor diodes and
microwave valves
   /
9081
nonstationary parametrons  to eliminate the necessity for the critical
adjustment of amplitude and phase of the excitation current dc controlled
and diode controlled parametrons were investigated  a fast decay
time was achieved with diode control resulting in a high speed of
operation in logic circuits
   /
9082
the cryosistor a new low temperature three terminal switch  a reverse
biased pn junction is used to control the ionization between two
ohmic contacts  its uses might be as a fast monostable or bistable
switch and as a pulse amplifier
   /
9083
observations of some theorems for linear passive networks  an extension
of cohns theorem for linear passive two poles see eg of is proposed
facilitating the determination of energy relations in such networks
   /
9084
theory of forced oscillations in electromagnetic cavities and the
equivalent circuit of a cavity  the em field inside an excited cavity
coupled to a two way transmission line is calculated on the basis
of a series expansion of arbitrary vector fields in cavity resonators
in terms of orthogonal eigenfunctions  the equivalent circuit derived
consists of an infinite number of lumped elements approximation formulae
for practical application are given
   /
9085
the cylindrical te mode cavity including a semiconductor sample with
tensorial electrical conductivity  the impedance matrix and characteristic
s matrix are derived for two configurations of the input guides
one case is suitable for the measurement of hall mobility and for
the other the proper conditions for use as an isolator are investigated
   /
9086
iterative networks as coupling networks in oscillator circuits  the
conditions for self oscillation are established for valve and transistor
oscillators  the characteristics of iterative networks consisting
of purely resistive and reactive elements are summarized and their
application in valve and transistor oscillators is investigated
formulae are given for operating parameters and are verified experimentally
   /
9087
explicit formulae for the calculation of the characteristic function
of filters with tchebycheff pass band behaviour
   /
9088
a wide band voltage controlled oscillator  continuously variable
frequency control of an lc oscillator over the range is obtained
by electronic switching of a number of fixed capacitors across the
inductance the number of depending on a dc control signal voltage
   /
9089
a transistor relaxation oscillator and its applications  the modifications
of the schmitt trigger circuit necessitated by the use of transistors
are investigated practical circuits and operating characteristics
are given
   /
9090
frequency division by carrier storage  a circuit using a junction
diode with forward bias that produces output pulses at half the frequency
of a input sinusoidal voltage is described  possible computer
applications r are noted
   /
9091
amplification by means of nonlinear reactances  the theory of parametric
amplification is considered on the basis of the manley rowe power
relations the properties of varactors and their use in parametric
amplifiers are discussed some experimental results are given
   /
9092
experimental demonstration of parametric amplification  simple experiments
are described to demonstrate the basic principles of pr parametric
amplification using a variable capacitance circuit and by means of
a mechanical system for setting up waves on a water surface
   /
9093
noise figure and gain of parametric converters  a correction is given
for a term in a noise figure equation for a parametric frequency
converter given in an earlier communication
   /
9094
an electron beam parametric amplifier for the region
   /
9095
power amplifiers based on electro optical effects  a survey the gain
bandwidth and noise factor of electro luminescent photoconductive
transducers are considered taking into account the effects of feedback
and matching  suggested practical applications of single and cascade
devices are discussed
   /
9096
instability effects in a semiconductor amplifier with negative effective
carrier mass  critical comment on the proposal of kromer
   /
9097
simple periodic behaviour of the ring modulator  an analysis of ring
modulator theory where the signal and carrier frequencies are equal
or one is a multiple of the other  curves are given for determining
the performance of frequency dividers of the miller type
   /
9098
theory of the complex refractive index  a quantum mechanical formalism
is developed for representing the complex refractive inded of a gas
   /
9099
theory of impurity resistance in metals  a many body technique is
developed for the calculation f the dc resistivity of a fermi fluid
in the presence of a few randomly distributed fixed impurities
   /
9100
electron relaxation time in a high frequency electromagnetic field
and the surface impedance of a metal  an analysis of effects due
to quantization of the em field and the electron orbits in a constant
magnetic field
   /
9101
the passage of electrons through a rectangular potential barrier with
a small cylindrical inhomogeneity  a treatment of the tunnel effect
in electron emission by first order perturbation theory
   /
9102
on certain special features of ohmic heating of an electron gas in
a plasma  an investigation of ohmic heating in a constant field taking
account of inelastic collisions shows that the electron temperature
may be in a steady state only for low values of electric field intensity
see also of
   /
9103
the origin of a backward wave in a nonmagnetized plasma cylinder
bounded by air  the conditions for the existence of such a wave are
derived
   /
9104
radiation of plasma oscillation  radiation of em waves from a mercury
discharge tube was picked up by a horn feeding a receiver tuned to
a peak value of received signal was obtained for a discharge current
corresponding to a plasma resonant at  reflections from the plasma
were also observed they reached a peak value at the same discharge
current but did not fall with higher currents
   /
9105
a note on effects of relatively strong fields on the propagation
of em waves through a hypersonically produced plasma  see of
   /
9106
a note on the relation between the exact and simplified theories
for em wave propagation in ionized gases  comment on and correction
to the paper by sisco and fiskin
   /
9107
cyclotron absorption of electro magnetic waves in a plasma  brief
analysis of the absorption due to the thermal motion of electrons
and ions
   /
9108
plasma oscillations in a magnetic field  a theoretical treatment
of longitudinal electron oscillations
   /
9109
stability of a plasma sheet in time periodic magnetic fields  the
behaviour of a thin sheet of electrons in a time varying square wave
magnetic field is investigated and it is shown that the growth of
an initial disturbance in the first half period is entirely annulled
in the second both the displacements and velocities returning to
their initial values
   /
9110
the field of an electric current in general relativity  a solution
is given for a wire loop for which it is necessary to endow the wire
with a gravitational mass which corresponds to the energy of the
magnetic field created  the gravitational effect of the current is
not far below the present limit of experimental detection
   /
9111
aoaipparatus for investigating polarization in the diffraction of
centimetric electromagnetic waves  a semi automatic rotating analyser
for measurement of the polarization of scattered waves in free space
is described  see also of
   /
9112
solution of a diffractive problem  the problem of radiation from
a semi infinite parallel plate waveguide terminated by an infinite
plane flange double wedge is investigated in the k representation
when the width of the double wedge is and
   /
9113
theoretical and experimental study of back scattering cross section
of an infinite ribbon  the geometrical optics approximation is derived
for the back scattering cross section per unit length of an infinite
ribbon  a comparison is made with the exact theory the approximate
theory of sommerfeld the variation method and with experimental results
obtained through the space separation method for the measurement
of back scattering cross sections in a parallel plate region
   /
9114
reflection of electromagnetic waves from a plasma moving in slow
wave waveguides  report of an experimental investigation carried out
at using a a helix slow wave structure to reduce the phase velocity
of the waves to  the double doppler effect observed in reflection
from a plasma piston increased the frequency by  application of the
effect for microwave amplification and frequency multiplication is
indicated
   /
9115
possible transmission of electromagnetic waves through a metal in
a strong magnetic field  analysis shows that an em wave propagating
along a magnetic field can penetrate a metal plate perpendicular
to the field if the larmor frequency is higher than the frequency
of the wave and much higher than the collision frequency and if the
larmor electron radius is smaller than the wave length in the metal
   /
9116
microwave spectroscopy  the basis of molecular modulation is discussed
with special reference to the stark effect and maser amplification
the various types of spectrometer and their applications are discussed
   /
9117
crossover transitions  finite rotation operators are used to simplify
the calculation of second order crossover transitions for a spin
system with trigonal symmetry  the resonant frequency and transition
probabilities for the crossover transition with negative d or with
positive d are calculated
   /
9118
the second moment of a paramagnetic absorption line taking account
of the effect of fine and hyperfine structures  formulae are derived
for calculating the reduced second moment of a resonance line and
the fine structure constants of nuclear and electron paramagnetic
absorption
   /
9119
corbino disk  a comprehensive treatment of the behaviour of the electric
current and magnetic field distribution patterns in a disk with concentric
inner and u outer contacts and a magnetic field applied along
its axis  the effects discussed are large in materials with a high
mobility such as bi ad the corbino disk appears to be useful as a
rectifier and voltage regulator
   /
9120
spin susceptibility of an electron gas  the generalized random phase
approximation is used to investigate the effects of electron electron
interaction on the spin susceptibility of an electron gas
   /
9121
electron levels in a one dimensional random lattice
   /
9122
apparent steady component of the interplanetary magnetic field  arguments
based on the results of coleman et al of ad on the direction and
sense of terrestrial storm fields show that the apparent steady component
of the interplanetary field also known as quiet time field is
probably directed from the north to the south of the ecliptic
   /
9123
existence of net electric charges on stars  comment on of ad authors
reply
   /
9124
cosmic noise absorption measurements at stanford california and pullman
washington  the absorption was measured at using a riometer  after
making allowances for the diurnal vz variations due to absorption
in the d and f layers a residual diurnal variation remains which
has not yet been explained
   /
9125
the cross sed grating interferometer a new high resolution radio
telescope
   /
9126
malvern radio telescope
   /
9127
a survey of radio stars at a frequency of  this paper describes a
survey of small diameter radiostars made with an interferometer at
the positions and flux densities of radio stars all of which are
confirmed by other surveys are given in the catalogue
   /
9128
relation of jupiters radio emission at long wavelengths to solar
activity  observations at boulder during the period january june
shows a strong positive correlation between jupiters emission in
the range and solar continuum emission  the time delay of one to
two days indicates that fast solar particles at velocities of about
may be involved in the planets atmosphere or magnetic field  see
also of february
   /
9129
sol radio emission on centimetre waves and ionization of the e layer
of the ionosphere  the correlation coefficient relating solar rf
noise flux on wavelengths between and to daily ad monthly e layer
indices described by minnis and bazzard of and of has been calculated
the coefficient lies in the range wavelengths between and cm b above
cm it falls to
   /
9130
radiation environment in space  summary of information on radiations
in space obtained by means o satellites and space probes
   /
9131
relation between results of measurements of charged particles by
means of traps on soviet cosmic rockets and measurements of the magnetic
field on the american satellite explorer and the rocket pioneer v
results of measurements carried out by different methods on the soviet
rockets indicate the existence of a geomagnetic belt of charged particles
from the centre of the earth
   /
9132
moon reflection studies with bistatic radar at the reception at austin
texas of moon echoes of transmissions from malvern england is reported
discrete spike echoes persisted for about  simultaneous observations
at malvern and austin show no correlation between individual spikes
this is interpreted in terms of an undulating lunar surface
   /
9133
radio echo measurements of the orbits of faint sporadic meteors
a survey has shown tht many such meteors move in orbits of very short
period  the moe eccentric orbits are near the plane of the ecliptic
but some are circular and have inclinations near  the significance
of the results is discussed
   /
9134
the calculation of meteor velocities from continuous wave radio
diffraction effects from trails meteor velocities are calculated
from the time interval between cw echo maxima or minima  neglect
of the initial phase relation between echo and ground wave introduces
large errors  an analytical method is described and preliminary results
are given
   /
9135
the structure and magnetic field of the solar corona  radio observations
in of the crab nebula made at using four interferometers are described
anisotropic spreading of the source occurred as it passed near the
sun  radial filamentary irregularities of ionization extending out
to solar radii are deduced
   /
9136
possible magnetic effects with high altitude explosions of atomic
bombs  the effects of a dense diamagnetic plasma expanding in the
earths magnetic field are discussed with reference to the periodic
magnetic disturbances associated with the argus experiment
   /
9137
an approximate method of estimating the size and shape of the stationary
hollow carved out in a neu  ral ionized stream of corpuscles impinging
on the geomagnetic field  a two dimensional case is considered in
which the permanent field is due to a current acting perpendicular
to the stream  the breadth of the hollow at infinity is shown to
be finite
   /
9138
the latitudinal distribution of magnetic activity in canada  measurements
of the hu hourly ranges in the principal horizontal field component
at canadian igy stations are described  a narrow zone or area of
enhanced magnetic activity exists at high latitudes with a maximum
near alert the seasonal and diurnal variations of magnetic activity
at different latitudes are also considered
   /
9139
perturbations of the orbit of the echo balloon  predictions of the
influence of solar radiation pressure are confirmed by the changes
in orbit of satellite during the first days after its launching
   /
9140
perturbations of the orbit of the echo baloon  predictions of the
influence of solar radiation pressure are confirmed by the changes
in orbit of satellite during the first days after its launching
   /
9141
observed solar pressure perturbations of echo i  a decrease in perigee
height of day and an increase in the eccentricity of per day were
observed during the first days after launching of
   /
9142
a method for interpreting the doppler curves of artificial satellites
a graphical analytical method for determining the point of inflexion
and the maximum slope is explained in detail  see
   /
9143
irregular fading of satellite transmissions  the distribution of
the mean scintillation index with magnetic inclination derived from
observations at slough of transmissions from is discussed in relation
to comments by mawdsley of
   /
9144
sudden amplitude variations of sputnik signals  two distinct causes
of drop outs in the signal received from are identified a change in
transmitter characteristics and a localized absorbing or scattering
region in the ionosphere
   /
9145
field aligned ionospheric irregularities and the scintillation of
satellite radio transmissions  observations of radio transmissions
from made at brisbane during july september have been analysed results
indicate that the scintillation activity associated with propagation
along the lines of the earths magnetic field is more pronounced than
that associated with other directions of propagation  the results
are in agreement with those of rush and colin
   /
9146
radar echoes obtained from earth satellites alpha and beta  observations
at stanford california using a radar with a steerable paraboloid
are described  echoes from and were seen on occasions  the echoes
usually lasted abu sec as the satellite crossed the aerial beam
cyclic fading at occurred usually with constant polarization and
attributable to satellite tumbling  on one occasion passed within ki
of an auroral disturbance detected on the radar large amplitude fluctuations
were seen and the echo lasted longer than usual
   /
9147
structure of the thermosphere  the vertical distribution of density
in the thermosphere as deduced from satellite observations is examined
and it is shown tht the varying scale height gradient s is due to
a decrease in the molecular weight of the atmospheric constituents
the temperature of the night time isothermal atmosphere and the distribution
of scale height in the sunlit atmosphere is related to the
ultraviolet heating available during the day
   /
9148
origin of the d region  the d region may result from the ionization
by lyman alpha radiation of molecules in an excited state  the mechanism
for the excitation of the molecules is discussed
   /
9149
anisotropy in ionospheric diffraction and its effect on drift measurement
a method of analysis is developed in which five statistical parameters
and a few simple formulae are used and which takes into account
te effects of random motion as well as anisotropy
   /
9150
lunar tide in the f layer of the ionosphere near the geomagnetic
equator  lunar variations of at leopoldville during the period november
october are analysed and compared with those for other low latitutde
stations  results suggest that stations having the same magnetic
latitude rather than the same geomagnetic latitude experience similar
variations of  see also of
   /
9151
insoc spread f and multiple scattering in the ionosphere  the mechanism
of spread f is examined statistically  a model is derived based on
the assumption of gallet turbulence in the underside of the f layer
under night time conditions and is applied in detail t a typical
example of article spread f
   /
9152
ionospheric disturbances at the time of cosmic ray increases  ionospheric
and magnetic conditions at the time of a cosmic ray increase on
january are analysed and compared with those at the time of an increase
on december although the cosmic ray increases were in some respects
analogous they were associated with quite different ionospheric conditions
   /
9153
enhancement of ionization in the e layer due to solar flares during
the international geophysical year  the value of observed at slough
at the hour preceding the commencement of each clare of importance
and and at the two succeeding hours have been examined in relation
to normal values  results show that during the interval min after
the commencement of a flare there is a mean increase in the intensity
of e layer ionizing radiation which is at least for class flares
and for class flares
   /
9154
spread f and the latitude variation of occurrence of whistlers  an
explanation of the latitude variation of whistler activity based
on propagation within field aligned ducts of is consistent with current
ideas for interpreting spread f echoes
   /
9155
on the generalization of the appleton hartree magneto ionic formulas
   /
9156
the polar radio black out of the ionosphere of  ionospheric data
are used to study the polar cap absorption effects occurring in both
hemispheres after the flare on july  it is suggested that electrons
first precipitated to the highest latitudes and then protons and
helium ions to lower latitudes
   /
9157
a theory of ionospheric currents associated with aurorae  the current
distributions induced by dynamo action in a sheet of partially ionized
gas moving with uniform velocity across a perpendicular magnetic
field are derived for the case where the gas contains an elliptical
region of greater ionization density  on the basis of the theory
the average ionospheric current flowing along a long homogeneous
arc is calculated and some results predicted by the theory are compared
with observational evidence
   /
9158
studies of auroral echoes part  the results of radar observations
at kjeller and tromso are discussed  the velocity and direction of
the drift of auroral ionization was measured by the technique used
at n jodrell bank by byllough and kaiser of in which the time variation
of echoes observed on aerials directed nw and ne is recorded  an
interferometer was used to measure fine structure and a vertically
sliding aerial to measure the angle of elevation of the arriving
echoes  the observed drift and structure at kjeller was similar to
that at jodrell bank but was more irregular at tromso
   /
9159
radar echoes from the aurora at  experimental results show tht the
reflecting layer has a mean height of and a thickness of  the results
r are discussed in relation to reflection theory  in general an auroral
disturbance of sufficient intensity to be observed at will only occur
after a very vigorous solar upheaval in association with extreme
magnetic storms
   /
9160
recent results in the investigation of the relation between lightning
discharges and whistlers  harmonic analysis shows that lightning
discharges which produce whistlers have a pronounced energy peak
near  multiple whistlers r are caused by multiple discharges through
the same lightning channel
   /
9161
speed control of dc motors  two designs of a continuously variable
type of servo system are s described the first employs a phase lock
feedback system and the second a simple velocity feedback system
   /
9162
multitapped potentiometers as accurate linear transducers  a method
is given for calculating the su shunt resistance values required
to compensate t for the load error which enables the potentiometer
resistance the minimum input resistance and the load to be independently
specified
   /
9163
durable high resolution ferrite transducer heads employing bonding
glass spacers  the construction is described of various types of
ferroxcube magnetic recording head which have high resistance to
wear and improved signal noise ratio
   /
9164
the development of the flexible disk magnetic recorder  the optimum
operating conditions for supporting a rotating flexible mylar disk
with magnetic coating above a rigid back plate using a gas film are
discussed
   /
9165
high density digital magnetic recording techniques  a comprehensive
readback simulation computer program is described which will automatically
simulate for any characteristic pulse all possible readback signal
patterns and test them for specified reading logic as a function
of bit density
   /
9166
analysis of the dc characteristic of selenium rectifiers  the method
of analysis given permits the separation of the various physical
phenomena in the rectification process  an empirical equation for
a limited section of the rectifier characteristic is derived  the
reduction of the slopof the logarithmic characteristic relative to
the theoretical value is attributed to the effect of the contact
of se with the n type intermediate layer of and
   /
9167
constant current supply for very high resistance loads  battery operated
transistorized equipment using a photo resistor for current control
in the range for any load resistance from zero to is described  measured
changes in current with various load conditions do not exceed
   /
9168
the testing of metal tape magnetic cores for use in a code translator
acceptance tests are described which simulate the actual conditions
under which the cores will be used
   /
9169
a multipurpose computer element  a long tailed pair waveform reshaper
is described which in conjunction with a number of logical gates
can be used as a basic element in computer design
   /
9170
microcircuit binary full adder uses unipolar transistors are used
for both active and passive elements
   /
9171
circuit considerations relating to micro electronics  a discussion
of the problems associated with microminiaturizatio especially power
dissipation ad and its relation to circuit functions and packing
density
   /
9172
barkhausen noise in transformer cores  the following are discussed
isolation and measurement of the noise its relation to the slope
of the hysteresis loop and the cycling rate an equivalent circuit
which includes the noise source and the frequency spectrum of the
noise when sinusoidally polarized
   /
9173
margin considerations for an esaki diode resistor or gate  worst
case margin considerations imply that applications are restricted
to storage systems flip flops shift registers and the like
   /
9174
a helix type variable capacitor  maximum to minimum capacitance ratios
of or more are obtainable
   /
9175
two terminal network functions through prescribed b points  additions
to the interpolation problem of pick and nevanlinna  the synthesis
of two terminal networks consisting of resistive inductive inductive
and capacitive elements and having a given impedance function is
considered
   /
9176
quartz at type filter crystals for the frequency range  design data
are given for suppressing the unwanted modes to at least below the
main mode see also of
   /
9177
design of cavity resonators with maximum q factor  summary of theory
and design formulae for cylindrical cavity resonators with details
of constructional features and coupling arrangements
   /
9178
exact solution of a time varying capacitance problem  a new method
is developed giving a closed form solution for the harmonics generated
by a sinusoidally varying capacitance in series with a fixed resistor
and battery  practical applications are discussed with reference
to the condenser microphone and vibrating reed electrometer and a
special loudspeaker improvement
   /
9179
the quadratic invariances of a generalized network  in systems where
the matrix operator has eigenvalues which are unity or can be taken
in reciprocal conjugate pairs the number of invariant quadratic forms
is at least equal to the number of degrees of freedom
   /
9180
the imaginary part of the characteristic impedance in the pass band
of filter circuits  the use of filter circuits with complex characteristic
impedance in the pass band extends the number of possible bridge
type filters  filters with variable pass ab band can be realised
   /
9181
a quick method for the design of butterworth filters  a design procedure
and worked example are given
   /
9182
a variable bandwidth a band pass filter  a method is described whereby
several bandwidths may be ot obtained in an lc filter employing one
set of inductors only  the design of a typical filter with an actual
plot of its attenuation characteristic is included
   /
9183
a continuously variable band pass filter for the audio frequency
range  the design of a band pass filter whose bandwidth and lower
cut off frequency are continuously variable is described  the requisite
crystal filters are derived from the band pass elements given by
image parameter theory  the equipment and some of its response curves
are illustrated
   /
9184
synthesis of n port active rc networks  it is proved that n is the
sufficient and in general minimum number of con  rolled sources required
to relize an arbitrary matrix of real rational functions as a transformerless
active rc n port network
   /
9185
the hamiltonian formalism of damping in a tuned circuit  an lc circuit
coupled to a transmission line is studied as an example of introducing
damping into the quantum mechanical treatment of a harmonic oscillator
the problem of coupling a spin system to the current in the inductance
is also studied
   /
9186
the stability of relaxation oscillations synchronized by pulses
a finite difference equation is derived for the pulse synchronization
of relaxation oscillators  solutions are obtained by a graphical
method and possibilities of simplification are considered  the procedure
is also applied to the case of frequency division  calculated parameters
are verified by measurements on a multivibrator circuit
   /
9187
description of the change over process in multivibrators  the dynamic
processes occurring in multivibrators are described using a graphical
method  a bistable circuit is considered as example and a system
of curves representing all possible internal processes is derived
on the basis of differential equations for the characteristic time
functions of this circuit  the influence of the duration and amplitude
of the triggering pulse on transition time is determined
   /
9188
cdecoding circuits with semiconductor elements  various types of
circuit for binary decoding systems are given and requirements regarding
the minimum number of semiconductor diodes and transistors to be
used are evaluated and compared
   /
9189
the problem of frequency synthesis  review of the basic techniques
employed for addition subtraction ad division in frequency synthesizers
   /
9190
continuously variable glass delay line  stress waves are optically
monitored by using the birefringent properties of glass under stress
   /
9191
designing grounded grid amplifiers with controlled gain  a six stage
low noise if amplifier with microminiature ceramic triodes is described
   /
9192
review of nonlinear distortion in transistor stages including cross
modulation  the nonlinear transfer function is approximated by a
taylor series expansion and from this equations are derived for various
types of distortion in earthed emitter transistor circuits  methods
of compensating cross modulation are considered  the results of cross
modulation measurements are found to be similar to those obtained
by akgun and strutt of
   /
9193
selective rc amplifier using transistors  investigation of the use
of phase shift networks in transistor circuits  the dual of the wien
bridge arm is used to form an oscillator and a selective amplifier
which has constant gain while the selectivity and tuning are continuously
variable
   /
9194
equation for the performance of a nonlinear transistor amplifier
a first order differential equation is derived to describe the performance
of a nonlinear amplifier discussed earlier by gumowski of
   /
9195
investigation of the shift in frequency and of the amplitude of oscillations
of z a maser type self oscillator with liquid flow  an experimental
investigation of the effect of detuning a maser oscillator of the
type described earlier of and of the influence of the rate of flow
on the resonance line width  the range of oscillation extends from
to
   /
9196
cross relaxation phenomena in solid state masers  with the direction
of the applied magnetic field close to the axis of a ruby maser amplification
for different crystal orientations was confined to two narrow
frequency bands within the rang used  possible mechanisms concerned
are spin spin energy exchanges involving four ions and seven ions
   /
9197
three terminal variable capacitance semiconductor device  an analysis
of the operation of the device which is based on the change in junction
transition capacitance associated with the change in collector voltage
gradient in an avalanche controlled semiconductor amplifier
   /
9198
a variable diode parametric standing wave amplifier  details are
given of experimental work on the type of amplifier discussed by
landauer
   /
9199
using voltage variable capacitors in modulator design  circuits and
design equations are given for phase and frequency modulators and
for ssb amplitude modulators
   /
9200
pseudo rectification and detection by simple e bilateral nonlinear
resistors  an analysis of ac dc converting circuits using symmetrical
nonlinear resistors the operation of which may be largely independent
of temperature  two applications are described for developing the
hv focusing potential bias for a picture tube and for improving the
detection threshold of a photoelectric sensing device
   /
9201
gausss principle of least constraint applied to electrical networks
gauss principle of mechanics when adapted to electrical networks
leads to kirchhoffs laws
   /
9202
swept langmuir probe system for intense gas discharges  apparatus
including a low impedance voltage sweep generator and a logarithmic
amplifier is described for measurement of electron temperatures up
to and ion densities up to
   /
9203
exploration of oscillating beam plasma fields with a transverse electron
beam  the results appear to be compatible with considerable randomization
and possible break up of the main beam by the oscillations
   /
9204
electrodynamics of the image force  the processes of ion emission
ad and absorption at semiconductor surfaces are analysed  see of
february
   /
9205
electron density fluctuations in a plasma  the spatial fourier transform
of the electron distribution is in a plasma is obtained together
with is time variation using assumptions consistent with an ionospheric
application
   /
9206
space charge instabilities in synthesized plasmas  potential transitions
dependent on boundary space charge conditions are shown to be possible
by a theoretical analysis of an idealized model  such transitions
are observed experimentally  the voltage jumps are in good agreement
with the theory
   /
9207
method for the determination of the electron density of a plasma
by group velocity
   /
9208
method of measuring simultaneously the confining magnetic field and
the electron density of a plasma  extension of earlier work
   /
9209
microwave measurements of the radiation temperature of plasmas  measurements
are described of radiation temperature of positive columns
of glow discharges in helium neon and hydrogen the microwave noise
radiation was detected at  the results are compared with calculations
and with langmuir probe measurements of the electron temperature
   /
9210
nonlinear phenomena in a plasma located in an alternating electro
magnetic field  a detailed treatment of elementary and kinetic theories
of a nonrelativistic nondegenerate plasma in a uniform electric field
with particular reference to the distribution function of electron
collisions the el effective electron temperature and total electric
current density  results are applied to determine the nonlinear effects
occurring in the in the propagation of radio waves in the ionosphere
including self interaction cross modulation and the interaction of
unmodulated waves
   /
9211
oscillations and diffusion in weakly ionized plasmas  the diffusion
of weakly ionized plasma particles is observed in a direction perpendicular
to the magnetic field
   /
9212
magnetic moment and magnetic charge  the definition of magnetic dipole
moment and magnetic charge in relation to the theory of permanent
magnets is discussed
   /
9213
some properties of concentrated and dilute heisenberg magnets with
general spin  the constant coupling approximation is used to obtain
the thermodynamic properties of a heisenberg ferromagnet above the
transition temperature and the dependendence of these properties
on magnetic concentration in an alloy is c considered  z antiferromagnets
are also discussed
   /
9214
the behaviour of magnetic systems with dilution  generalization of
the bethe peierls weiss method to the case of alloys and application
to the dilution of classical heisenberg ferromagnets with nearest
neighbour interaction only
   /
9215
microwave modulation of light in paramagnetic crystals  the considerations
of dehmelt and others about the modulation of light by rf signals
in atomic vapours are extended t paramagnetic solids  experimental
design criteria are discussed and some possible applications reviewed
   /
9216
anisotropic magnetization  discussion of the magnitude and temperature
dependence of anisotropic magnetization with application to different
classes of materials
   /
9217
electromagnetic energy density in dispersive media  general expressions
for energy densities and losses are derived
   /
9218
electromagnetic reflection from sound waves
   /
9219
inhomogeneous waves in the diffraction field near loss free dielectric
circular cylinders  measurements were made at of the diffraction
field near solid and hollow dielectric cylinders of equal external
diameter placed in a parallel plate transmission line  results are
compared with those obtained for a solid metal cylinder of equal
diameter and with the field distribution given by a graphical method
an explanation is given of the inhomogeneous waves which contribute
to the measured diffraction field
   /
9220
diffraction by an irregular screen of limited extent  information
that may be derived about the screen by measurements of the diffraction
pattern at different distances is considered  close to the screen
the pattern gives information about the small scale structure at
greater distances it is related to the overall extent of the screen
measurements of the angular diameter of stars ionospheric irregularities
and meteor trails are discussed
   /
9221
diffraction by finite irregular objects  the problem considered in
above is treated by a different method  its application to lunar
radio echoes is discussed
   /
9222
nonresonance absorption of electromagnetic waves in a magneto active
plasma  analysis of the absorption of ordinary extraordinary and plasma
waves outside the gyromagnetic resonance regions taking account of
collisions and the specific absorption mechanism
   /
9223
growth of electromagnetic waves in interpenetrating infinite moving
media  phenomenological treatment of the propagation of plane monochromatic
waves in mutually interpenetrating media  equations are derived
for the refractive index and are applied to the problem of stability
build up and damping factors are determined for the case of a plasma
moving through a dispersionless dielectric
   /
9224
influence of frequency and structure on the complex refractive index
of metals and thin metallic films
   /
9225
quantum theory of spatial dispersion of electric and magnetic susceptibilities
electromagnetic effects in a homogeneous medium can be described
in terms of a conductivity dependent on frequency and wave vector
and a susceptibility dependent only on the wave vector  a universal
relation between conductivity and susceptibility is derived
   /
9226
the influence of coherent magnetic dipole radiation field on magnetic
resonance  corrections to the relaxation time and resonance frequency
shift due to the effect of the radiation field are computed
   /
9227
beam type masers for radio frequency spectroscopy  the behaviour
of the beam type maser is considered theoretically with particular
regard to sensitivity and line width  experimental results for a
formaldehyde transition are given for comparison
   /
9228
general spin wave dispersion relations  the derivation takes into
account the effects of conductivity exchange and propagation
   /
9229
calculation of the widths of ferrimagnetic absorption lines and of
relaxation times in the case o spin waves of non negligible amplitude
   /
9230
pulsed field measurements of large zero field splittings
   /
9231
the hamiltonian formalism of damping in a tuned circuit
   /
9232
proposed fibre cavities for optical masers  the practical possibilities
of employing fibres as dielectric waveguides at optical infrared
wavelengths ar discussed
   /
9233
electron effective mass in solids a generalization of bardeens formula
a formula is derived for the effective mass of an electron in a crystal
which replaces the sum over excited states in the usual sum rule
by an integral over the surface of the unit cell  the integrand
of the surface integral involves the wave functions at the symmetry
point or band extremum ad a second solution of schroedingers equation
at the same energy but satisfying inhomogeneous boundary conditions
on th cell surface
   /
9234
an all electric univers  outline of theory ascribing the evolution
of the universe to electrical discharge processes  an interpretation
is given of observed cosmic phenomena
   /
9235
the theory of force free magnetic fields  the general features of
force free magnetic fields are established and several models are
discussed in relation to special coordinate systems  see also
   /
9236
a curious feature of the radio sky  an examination of existing theories
regarding the spur of intense radiation which appears to emerge from
the galactic plane at about and to run upwards towards the north
galactic pole  radio observations may be interpreted more reasonably
in terms of an irregularity in the local spiral structure or a remnant
of a supernova
   /
9237
observations of cosmic radio noise at in hawaii  cosmic radio noise
measurements at hawaii on a frequency of are described  on numerous
occasions considerable flux continued to arrive when thef region
critical frequency exceeded  this effect is possibly due t cosmic
radio radiation being trapped and propagated under the ionosphere
attenuation measurements suggest that an ionospheric window effect
exists
   /
9238
secular variation f the flux density of the radio source cassiopeia
a  comparative measurements at on the rf sources in cassiopeia a
and cygnus a indicate that the flux density of cassiopeia a is decreasing
at a rate of per annum
   /
9239
statistical analysis of radio star scintillation  radio star scintillation
data are analysed by statistical techniques t find the auto correlation
functions and power density spectra of the fluctuations in amplitude
and phase  interpretation is given in terms of a drifting phase
changing screen as postulated by booker ratcliffe shinn of  it is
shown how the drift velocity of the irregularities in ionospheric
electron density that lead to the scintillations as well as the mean
square amplitude and phase of the fluctuations may be obtained from
these records
   /
9240
preliminary report on positional fluctuations of solar radio sources
on mc  an analysis indicates that the magnitude of the positional
fluctuations is less when the solar rf source is closely connected
with a magnetic field in the active region  no increase in the magnitude
of positional fluctuations was found on as the source moved towards
the solar limb
   /
9241
on the features f storm bursts in the range  the characteristics
of short pips which occur during noise storms are discussed  for
brief reports of this work see and of
   /
9242
solar noise burst of november  a burst of rf noise of high intensity
is associated with a flare from a sunspot area which had just disappeared
behind the suns west limb
   /
9243
mirror and azimuthal drift frequencies for geomagnetically trapped
particles  the charged particles trapped in the geomagnetic field
the frequencies of the mirror oscillations and the azimuthal drift
are defined as appropriate averages over the helical motion around
the field lines and the mirror motion between reflection points in
the two magnetic hemispheres  these integrals for and are evaluated
numerically  results are tabulated illustrated and represented by
approximate analytical expressions
   /
9244
investigation of cosmic rays and terrestrial corpuscular radiation
by means of rocket and satellite flights  detailed report of observations
showing that the earth is surrounded by two separate zones of
high intensity radiation  the outer zone is composed of electrons
ad in the equatorial plane extends from to km from the centre of
the earth  it comprises two main energy groups of the order of and
the inner zone extends from to about km above the earth and is composed
of protons with energies of  see also and
   /
9245
the cosmic ray flare on november and solar activity during the period
november  short report of optical radio astronomical cosmic ray and
earth current observations made at nera netherlands paramaribo and
hollandia
   /
9246
interplanetary magnetic field and the auroral zones  the current
system is explained qualitatively using hoyles suggestion that auroral
particles are accelerated at the neutral points between the geomagnetic
and interplanetary fields
   /
9247
pulsations of the earths electromagnetic field with periods of to
seconds and their connection with phenomena in the high atmosphere
pulsations are closely correlated with aurora and the various phases
of magnetic storms  the time of onset of a storm sudden commencement
determined from pulsation data appears to be the same within a few
seconds over the whole world
   /
9248
world wide characteristics of geomagnetic micropulsations  the characteristics
of associated with negative or positive bays in the auroral
zone are examined and a distinction is drawn between short period
and those of longer periods  the long period continuous pulsations
which appear simultaneously with in polar regions are also discussed
equivalent overhead current systems are derived for particular cases
of each type
   /
9249
a theory of polar geomagnetic storms  the third of a series of papers
which outline a hydromagnetic theory of storms see and of  the three
phases of the variations are accounted for by hall currents set
up around space charge accumulations in the lower ionosphere  these
accumulations result from the deformation of lines of force due to
interaction with the solar wind near and hr local time
   /
9250
the application of ray tracing methods to radio signals from satellites
   /
9251
project oscar  general information is given about a g proposed orbital
satellite carrying amateur radio
   /
9252
telemetry signals from sputnik  the equipment transcribes from magnetic
tape to mm film displaying the coded pulse signals in a raster form
which clearly shows pattern changes  the telemetry coding system
is given and two transits are analysed
   /
9253
scale times and scale lengths of variables with geomagnetic and ionospheric
illustrations  the conception of the atmospheric scale height
is generalized to apply to any scalar or vector function of time
and or position  examples are given relating to magnetic fields and
the ionosphere
   /
9254
a maximum of temperature in the middle ionosphere  a method is outlined
for determining variations in scale height h and electron density
with height from profiles and from calculations of the electron loss
results obtained from observations at puerto rico show that h has
a maximum value at a height of about km with considerable daily and
yearly variations
   /
9255
a new method for the calculation of profiles from ionospheric curves
the basic integral for virtual height has bee rearranged so that
the integrand is a function of phase refractive index instead of
group refractive index  this technique avoids an infinity in the
integrand at the reflection condition
   /
9256
the effective recombination coefficient of an ionosphere containing
a mixture of ions  the effective recombination coefficient in the
e layer can be estimated from the fall in electron density during
the night from the changes during solar eclipses from the time lag
in the diurnal peak density  these coefficients can be expressed
as functions of the coefficients for each of several different ions
present and are shown to be different from each other  it is suggested
that and are the ions responsible during the day and that no ions
predominate at night
   /
9257
the formation of the sporadic e layer in the temperature zones  a
hypothesis for e formation based on the observation that e occurrence
is correlated with the horizontal intensity of the earths field see
of  if the horizontal wind varies vertically the horizontal field
will produce vertical motion of electrons ad ions  an accumulation
of electrons will occur at the height for which the vertical velocity
passes through zero  the theory also accounts for the persistence
of e
   /
9258
seasonal variations of mean electron density at heights between and
electron density profiles are given for summer and winter which are
based on observations of faraday fading of signals from satellite
   /
9259
a note on the cause of sudden ionization anomalies in regions remote
from high altitude nuclear bursts  the sudden changes in vlf propagation
characteristics associated with the nuclear explosions over johnston
island are attributed to bomb induced ionization in the ionospheric
d layer  it is suggested tht this ionization is caused by particles
resulting from the decay of fission neutrons
   /
9260
geomagnetic disturbance effects in equatorial e  a correlation between
the disappearance of equatorial e observed at kodaikanal india and
magnetic storm disturbances is reported  a lowered e critical frequency
occurs with a decrease in horizontal magnetic force
   /
9261
the total electron content of the ionosphere during te magnetic disturbance
of november  measurements of the total electron content of the
ionosphere have been made with the radio telescope at jodrell bank
by observing the differential faraday fading of lunar radio echoes
results show that the reduction in maximum electron density was accompanied
by a proportional reduction in
   /
9262
ionospheric absorption at times of auroral and magnetic pulsations
variations in auroral absorption during march and april were closely
related o to magnetic field micropulsations and short period intensity
changes at  the amplitudes of the magnetic micropulsations were diminished
during periods of polar cap type absorption
   /
9263
a no  e on polar blackouts  the twilight effects in polar cap blackouts
are explained in terms of the c detachment of electrons from negative
oxygen ions in the region of and higher by visible light h which
has been attenuated in the atmosphere
   /
9264
ionosphere review  declining sunspot activity forced signal frequencies
down
   /
9265
an estimate of electron densities in the exosphere by means of nose
whistlers  by examining successive members of families of nose whistler
for march it was possible to choose between three mos of electron
density distribution for the exosphere the distribution with the
best fit was where n is electron density r is the distance from the
earths centre and k is a constant  this fact suggests that the density
at earth radii is of the order of electrons cm
   /
9266
a study of auroral coruscations  coruscations represent of the total
light in the region and have a period of sec  they are closely related
to pulsations and ionospheric absorption of cosmic radio noise  the
electron density profile associated with the aurora was found to
have a maximum in the e region of electrons cm
   /
9267
spaced observations of the low frequency radiation from the earths
upper atmosphere  observations of radio noise with a network of four
stations extending across southern australia are described  it is
shown tht there is often good correlation of the amplitude variations
over a distance of and tht the observed amplitude differences may
be explained by assuming tht the radiation propagates in the earth
ionosphere waveguide from geographically large sources  some discrete
sources were observed
   /
9268
sferics from intracloud lightning strokes  the experimental observation
tht many elf atmospherics are of negative polarity indicates that
intracloud lightning strokes radiate significant energy at very low
and extra low frequencies  see alsf
   /
9269
the magnetic flash of the nuclear test of february at reggane  an
em signal originating in the explosion at reggane has been recorded
with a field strength of at a distance
   /
9270
experiments on magnetic tape read out with an electron beam  the
feasibility of the method is demonstrated experimentally  theoretically
a video signal with a bandwidth of could be reproduced with a signal
electron shot noise ratio of from a recorded area density of cycles
mil
   /
9271
telemetry signals from sputnik
   /
9272
precision variable frequency power supply  a ballast tube in thermal
regulating bridge controls the amplitude of the output and an adjustable
filter controls the frequency from to
   /
9273
unconventional methods of generating electrical power  a review of
methods for the direct generation of electricity from other forms
of energy including methods based on electrochemical and photoelectric
conversion solid state devices and high velocity ionized gas  a comparative
table of the principal devices is included
   /
9274
considerations on the solar cell  the absorption curve of the material
and solar spectrum effects are contained in a single function readily
obtained by numerical integration
   /
9275
stabilization of a magnetic field by a nuclear magnetic resonance
maser  the system briefly described will give an absolute long term
stability within part in
   /
9276
overload protection for transistor voltage regulators  various circuit
modifications are described for protection against overload
   /
9277
patterns of thin films make fast nondestructive memories  the kerr
magneto optic method is used to show that irreversible domains can
be formed in thin magnetic films
   /
9278
the problem of coupling in a switching circuit system circuit consisting
of thin magnetic films  problems relating to the design of logic
switching circuits formed by magnetic film elements are reviewed
   /
9279
the impedance value of carbon film resistors as a function of frequency
and dc resistance  an arrangement is described for impedance measurements
in which the dimensions of the mounting are standardized in relation
to resistor dimensions so that comparisons are possible between results
obtained for resistors of different size  curves are given of maximum
usable frequency as a function of dc resistance and of skin effect
as a function of frequency and surface resistance
   /
9280
methods o analysis of circuit transient performance  a survey of
some numerical methods for studying the performance parameters associated
with transient behaviour of switching circuits
   /
9281
properties and characteristics of tantalum capacitors with solid
electrolyte
   /
9282
nonlinear thermal fluctuations in a diode  as an example of nonlinear
noise the fluctuations in a circuit consisting of a diode and a capacitor
are studied and th complete fluctuation spectrum is calculated
   /
9283
time delay and frequency response of resonant cavities  the frequency
response and time delay characteristics of resonant cavities are
discussed  it is found that a signal travelling through a resonant
cavity undergoes a time delay dependent on both the cavity q and
also the difference between the signa and resonant frequencies  the
time delay for a frequency modulated wave is calculated and checked
experimentally
   /
9284
application of distortion functions to instananeous nonlinear circuits
mathematica treatment of nonlinear nonreactive networks using the
functions derived in of
   /
9285
the propagation coefficient of a general linear quadripole  current
and voltage relations in a quadripole joining two transmission lines
are calculated using methods of image parameter theory
   /
9286
determination of the characteristic impedance of any quadripole at
microwave frequencies  measurements made on the quadripole under
certain load conditions are used in determining the characteristic
impedance by a graphical method
   /
9287
the modification of wide band noise phenomena by linear transmission
systems  for simple types of filters the distortion of the power
spectrum and autocorrelation function is investigated with wide band
noise as input  relations between parameters of classical and of
statistical system theory are derived
   /
9288
antimetric ladder filters  all parameters of a quadripole antimetric
ladder filter are shown to depend on four polynomial functions of
being the complex angular frequency between which a relation exists
the theory is applied to antimetric band rejection filters and to
high and low pass filters and tables are given facilitating calculations
   /
9289
extension of the possibilities of filter circuit construction by
means of regions of imaginary characteristic impedance in the pass
bad and regions of real characteristic impedance in the stop band
the choice of filters with favourable transient characteristics
the design of networks with the desired characteristics for pulse
shaping circuits is based on an analogue computer method of examples
are given of filters with idel idealized response or with transfer
function approximated by polynomials
   /
9290
audio frequency comb filter  details r are given of the design of
a mechanical system consisting o a stretched metallic string for
suppressing hum and associated harmonics in the output of an af amplifier
experimental results are noted
   /
9291
the scattering matrix of generally interconnected multipoles  the
scattering matrix of the network is formed by the simple manipulation
of matrices based on the scattering matrix of the individual multipoles
   /
9292
research on submillimetre wave generation and techniques  experiments
and experimental equipment are described for investigations on sub
mm wave generation including a tornadotron in which em radiation
is produced by the action f of pulsed magnetic fields of the order
of on a trapped electron cloud  aspects of instrumentation suitable
for these frequencies are briefly discussed
   /
9293
frequency modulation o a pound stabilized oscillator  a method is
outlined for applying frequency modulation ot an improved pound stabilized
oscillator of herve  the frequency deviation is limited to about
   /
9294
impulse governed oscillator techniques  part  theoretical aspects
of igo techniques are given  part
   /
9295
microwave generators for the ien caesium standard  two microwave
generators are described which are used in the atomic frequency standard
of the istituto elettrotecnico nazionale in turin for cs resonance
excitation by molecular beam technique  measurements of phase drift
and frequency stability are also considered
   /
9296
plate voltage control of phantastron frequency  two pentodes each
forming a phantastron circuit are interconnected so that both mark
and space of their combined output waveforms are controlled by linear
rather than exponential sweeps  circuit jitter is less than at pulses
sec repetition rate
   /
9297
phantastron circuits using transistors  arrangements of three transistors
to simulate the screen anode current partition of a pentode enable
transistron type circuits to be designed
   /
9298
the eccles jordan circuit with transistors for high speed counters
a static analysis of a transistor flip flop circuit is given and
the counting frequency limits for high speed counters consisting
of balanced flip flop elements are discussed  circuits operating
at frequencies in excess of are described
   /
9299
one tunnel diode flip flop  a note on the operation of a simple bistable
device
   /
9300
designing tunnel diode oscillators  analysis of relaxation oscillators
and associated circuits for sine wave and square wave generation
   /
9301
mathematical analysis of pulse networks  linear systems are analysed
which comprise an element capable of converting a continuous input
function into pulses of any desired shape  a pulse network equation
is derived which is applicable to closed loop control systems
   /
9302
the generation of very short needle shaped pulses  the design of
pulse generators and pulse shaping networks is discussed  details
are given of a double differentiating network for the generation
of pulses of amplitude further improvements by means of tunnel diodes
appear possible
   /
9303
low level linear microsecond gate  a six diode gate linear over the
range is described
   /
9304
a solenoid delay line with constant delay  description of a compact
delay line which consists of a solenoid wound on a ceramic tube of
high dielectric constant with a metal core  delay can be made independent
of frequency with an appropriate tube core diameter ratio
   /
9305
the effect of an intermediate layer on the frequency characteristics
of ultrasonic delay lines  general expressions are derived for the
line conversion factor taking account of an intermediate layer between
the transducer and the line  the effect of this layer on the frequency
characteristics and transmission band is considered and the relevant
characteristics of different transducer and layer materials are tabulated
   /
9306
amplification modern trends techniques and problems
   /
9307
the behaviour of a nonlinear transistor amplifier in the region of
its stability limit  an extension of earlier work  the limit of stability
of the amplifier is established from the form of the solution
of a first order differential equation describing the amplifier
   /
9308
transistor amplifiers with feedback  analysis of the properties of
transistor amplifiers using the parameters  feedback circuits with
special characteristics are reviewed  over references
   /
9309
semiconductor amplifiers and generators with carriers having negative
effective mass  it is not possible to produce states with negative
losses in a semiconductor by means of a constant electric field it
is necessary to have a state with negative losses in a semiconductor
by means of a constant electric field it is necessary to have a state
with negative temperature as achieved in molecular generators or
using pulsed excitation by a electric field
   /
9310
cross relaxation masers  the ways in which ruby spinel rutile and
emerald can amplify at frequencies small compared with their zero
field splitting frequencies are surveyed  cross relaxation is shown
to give a two fold improvement in maser performance  analytic expressions
for the energies are given
   /
9311
sewsaw maser operation  cross relaxation between adjacent intervals
may be used to secure an advantage in maser operation comparable
to that obtained by push pull pumping  equations for the rate of
change of populations in a scheme of four levels when ac is pumped
and cross relaxation takes place bt between have been formulated
and the steady state condition corresponding to various assumptions
regarding lattice relaxation times is discussed  in an experimental
investigation of maser operation based on this scheme and using ruby
as the active material an inversion of was obtained at a signal frequency
of when pumping at
   /
9312
travelling wave parametric amplifier analysis using difference equations
a second order difference equation is derived for both periodically
and uniformly distributed parametric amplifiers  gain and voltage
output are calculated  the results are specifically applied to an
lc distributed amplifier
   /
9313
effect of upper sidebands in travelling wave parametric amplifiers
the effect of higher sidebands on paramagnetic amplification is investigated
for circuits of limited bandwidth and infinite bandwidth
   /
9314
theoretical considerations regarding the application of parametric
amplifiers to radio telescopes  the improvement of resolving power
obtained by using one parametric amplifier immediately preceding
the aerial and another as preamplifier stage of the receiver is discussed
   /
9315
parametric amplifier for space probe tracking  description of the
parametric amplifier used with th jodrell bank radio telescope for
reception of the pioneer v space probe signals from distances of
over miles  a description of a parametric amplifier tester using
transistors is included
   /
9316
parametric circuits at low frequencies using ferrites and thin magnetic
films  the design of parametric circuits incorporating ferrite cores
and films with nonlinear characteristics is discussed  films appear
to be more suitable for operation at higher frequencies  an advantage
of the use of ferrite and magnetic film devices is their resistance
to nuclear radiation
   /
9317
the reactance tube as a parametric frequency divider and amplifier
derivation of the equivalent circuit of a parametric amplifier in
which a reactance valve functions as a time varying inductance  i
if the signal source is removed the circuit will operate as a frequency
divider where the output is a subharmonic of the pump frequency
   /
9318
energy balance in a parametric electron beam amplifier
   /
9319
coupled mode theory of electron beam parametric amplification
   /
9320
designing tunnel diode rf amplifiers  a strip line filter and tunnel
diode are combined to give low noise amplification at uhf in a small
module
   /
9321
time averaged effects on charged particles in ac fields  the basic
theory is developed and applied to plasmas including some cases with
a dc magnetic field  a bibliography and a critique of theory and
experiments are included
   /
9322
transient response of a thermo couple circuit under steady currents
   /
9323
experimental study of anomalous electron stream behaviour  experimental
measurements on the characteristics of the sole current in a rectilinear
crossed fil field beam are reported  the sole current may be assigned
a kinetic temperature of the order of corresponding to energy in
excess of that corresponding to motion in static fields  the energy
exchange leading to this excess energy exchange leading to this excess
energy is believed to be associated with multiple loop trajectories
in the low potential region near the cathode
   /
9324
noise generated in the ion sheath of a probe  the frequency dependence
of the saturated diode current is examined theoretically and results
obtained are compared with measured values
   /
9325
the general theory of the motions of ions and electrons in gases
the chief formulae for the drift velocities and diffusion coefficients
of ions and electrons in gases are derived in general form by the
application of dynamical principles
   /
9326
an error in the thermal conductivity for a fully ionized gas  a discrepancy
between formulae of marshall and of rosenbluth and kaufmann
of is due to an error in the last collision integral of marshall
   /
9327
the investigation of high frequency plasmas by means of a dc probe
   /
9328
instability of longitudinal oscillations of an electron ion plasma
in an isotropic plasma the oscillations are always damped in an anisotropic
medium ion motion may lead to instability
   /
9329
interaction of an electron beam with plasma  an experimental investigation
of modulated and unmodulated beams of high energy electrons with
a high frequency discharge plasma is reported  when an unmodulated
beam moves through the plasma oscillations are produced in the beam
at frequencies close to the plasma frequency
   /
9330
interaction of an electron beam with a fully ionized plasma  an electron
beam modulated at microwave frequency passes through a thermal plasma
critical frequency cyclotron frequency gain in beam modulation amplitude
is measured  theory is outlined which predicts gain for with a maximum
at  preliminary experiments agree with theoretical predictions  a
measured gain at is reported
   /
9331
magnetic polarizability of a short right circular conducting cylinder
a comprehensive mathematical analysis using a method given earlier
of february
   /
9332
production of magnetic fields exceeding kilogauss by a superconducting
solenoid  experiments with in wire form are described  critical field
data are given
   /
9333
cherenkov radiation of a particle possessing a charge and an intrinsic
magnetic moment  analysis by quantum electrodynamic methods of the
effect of the spin on the intensity and polarization of the radiation
produced in a ferrite by a charged particle with an intrinsic magnetic
moment
   /
9334
energy momentum tensor for plane waves  a general form is established
for the energy gating in a homogeneous medium the field equations
of which are derivable from a quadratic lagrangian function
   /
9335
limit of applicability of the method of smooth perturbations i the
problem of wave propagation through a medium with inhomogeneities
mean square values of the phase and amplitude fluctuations and of
the amplitude correlation function are discussed  conditions are
determined under which the effect of the layer with inhomogeneities
on the traversing radiation can be replaced by the perturbation action
of an equivalent phase screen
   /
9336
diffraction of a scalar wave by a slit and by a circular aperture
in a screen of arbitrary thickness  an expression is derived for
the transmission coefficient and its variation as a function of screen
thickness and aperture size is plotted
   /
9337
an electromagnetic diffraction problem involving unidirectionally
conducting surfaces  the exact value of the em field scattered by
a undirectionally conducting surface under plane wave excitation
is obtained  the surface which is an entire plane is the junction
of two unidirectionally conducting half planes whose conductivity
directions are inclined at an arbitrary angle to each other and to
the boundary line
   /
9338
on the theory of diffraction by a composite cylinder  general formulae
are developed for the diffraction field around a perfectly conducting
cylinder with a dielectric sleeve  these formulae represent the field
due to a unit electric line source parallel to the cylinder  limiting
cases are examined
   /
9339
gyro resonance absorption of electromagnetic waves in a plasma  an
earlier analysis is extended to frequencies near the gyro frequency
and multiples of this taking account of the thermal motion of electrons
   /
9340
microwave analogue to the scattering of light by nonspherical particles
total scattering cross sections and angular distributions have been
measured some approximate theoretical methods appear to be useful
the results are referred to the effects of interstellar matter on
starlight
   /
9341
paramagnetic resonance spectroscopy at zero magnetic field  two spectrometers
covering the range are described
   /
9342
frequency stabilization scheme for the pound watkins rf spectrometer
a scheme is described for locking the frequency of a marginal oscillator
rf spectrometer to that of an external standard  this makes it convenient
to use such a spectrometer for high resolution nmr work
   /
9343
comparison of the sensitivities of the beam maser and cavity absorption
spectrometers  a formula is derived for the signal noise ratio of
the beam maser considering it as a special case of cavity spectrometer
the sensitivity of the maser rr relative to the spectrometer varies
inversely with the frequency
   /
9344
high level oscillator for nuclear resonance  a modification of the
cathode coupled circuit see og of which functions at rf levels in
the range
   /
9345
theory of laser oscillation in fabry perot resonators an approximate
condition for oscillation is derived
   /
9346
stimulated optical emission from exchange coupled ions in
   /
9347
simultaneous optical maser action in two ruby satellite lines  maser
oscillations have been obtained simultaneously at wavelengths of
and is concentrated ruby
   /
9348
population inversion and continuous optical maser oscillation in
a gas ds discharge containing a he ne mixture  experimental data
on the physical properties of the system are discussed
   /
9349
radio wave absorption of several gases in the to frequency range
an extension of earlier work of to the gases and  they were contained
within a diameter tube up to long and a wide pressure range was used
   /
9350
precise measurement of the microwave absorption frequencies of the
oxygen molecule and the velocity of light  ten microwave absorption
frequencies of the oxygen molecule in the region have been measured
with an accuracy of about  the result is interpreted by successfully
refining the existing theory  comparing the resultant value of the
rotational constant b with the value obtained in ultraviolet spectra
the velocity of light is calculated to be km
   /
9351
a catalogue of radio sources between declinations  this list of sources
supplements a previous catalogue for declinations between and of
angular sizes of the strongest sources are given several of these
being less than arc in size
   /
9352
a receiver for radio astronomy and some observational results  description
of a superheterodyne receiver in which the hf amplifier contains
two disk seal triode valves in cascode the effective cathode resistance
of the second valve being made very high by a simple neutralization
circuit  a noise factor of has been obtained at  radio astronomy
observations are described which have been made with this receiver
and the parabolic reflector at swingeloo  an isophot chart of the
sky drawn from these observations is reproduced
   /
9353
an interferometer for the measurement of radio source sizes  the
cross type radio telescope at sydney o has been modified to study
sources in the range arc  the instrument and its operation are described
   /
9354
direction finding on diffuse sources of electromagnetic radiation
by combining the characteristics of an adcock type and rotating loop
type of direction finder the position and size of an extended source
can be determined
   /
9355
an attempt to detect linear polarization in the galactic background
radiation at  observations of a strip of sky about declination set
an upper limit of to the degree of linear polarization for bandwidths
of
   /
9356
recent developments in solar radio astronomy
   /
9357
the radio brightness of the quiet sun at cm wavelength near sunspot
maximum  th quiet sun temperature measured using pencil beam and
fan beam techniques is approximately  this value is twice that for
the same wavelength at sunspot minimum
   /
9358
investigation of the relative positions of solar radio storm sources
and of associated optical centres of activity  a comparison has been
made between the mean positions of radio storm centres observed sunspots
results show a systematic difference between the apparent and
true positions of the former and for more intense storm centres a
directivity effect with latitude
   /
9359
solar radio emissions and geophysical disturbances during july
   /
9360
cosmological significance of angular measurements of distant radio
sources
   /
9361
solar proposed cosmic rays near the north and south poles  results
of ground observations during the storms of and november are presented
   /
9362
x rays from van allen belt electrons  it ought to be possible to detect
the x ray flux at peak intensity above the cosmic radiation background
at baloon altitudes
   /
9363
electrons in the primary cosmic radiation  extraterrestrial electrons
with energies in the range and greater have been observed on three
baloons flights
   /
9364
charged particles in the inner van allen radiation belt  results
are given for the flight through the inner van allen belt of emulsion
stacks carried in an atlas rocket  the measured proton energy spectrum
was in accord with a cosmic ray albedo source down to  however below
the spectrum exhibits structure with a maximum at and a minimum at
penetration of solar protons into the belt over a period of days
can explain the effect
   /
9365
hydromagnetic waves and the trapped radiation  a theoretical discussion
and comments on the results of the argus experiment
   /
9366
an estimate of the peak sunspot number in  detailed analysis of the
statistical properties of the twenty peaks in the sunspot cycle since
results of which were given earlier of
   /
9367
unusual solar disturbance  no solar flare could be observed at the
time of a radio disturbance of importance at on june  the flare became
observable after a delay of  this and other anomalies are discussed
in relation to two assumptions concerning the flare that it occurred
on the far side of the sun that it originated at a lower level in
the suns z atmosphere than the source of rf emissions
   /
9368
geomagnetic micropulsations  simultaneous observations latitudes
and sho  ed no change in period with latitude but a monotonic increase
in amplitude for periods between and sec  the interpretation of these
results is discussed
   /
9369
the simultaneity of geomagnetic sudden impulses analysis of several
events during the igy shows that sudden impulses are propagated from
high latitudes to low latitudes in times of about min
   /
9370
the theory of artificial satellites in terms of the orbital true
longitude  previous theory of has been developed in terms of orbital
true longitude and leads to faster convergence for large eccentricities
and to a smaller number of terms in the series representing the perturbations
   /
9371
on the large scale regions of irregularities producing scintillation
of signals transmitted from earth satellites  evidence is presented
which indicates that absence of scintillation is not due primarily
to high aspect sensitivity of scattering from field aligned irregularities
   /
9372
ionospheric scattering of satellite trn transmissions  reports of
observations of night time scintillations of satellite transmissions
are briefly analysed in relation to the position of the observing
station and the direction of passage of the satellite  results demonstrate
the ability of field aligned irregularities to scatter radio
waves in a manner highly sensitive to aspect  see also of april
   /
9373
observed field strength in te neighbourhood of the skip distance
examples of ray focusing due to the satellite crossing the skip distance
boundary are given  the skip distance agrees well with h values derived
from ionograms
   /
9374
ion neutral reactions  a list is given of reactions which may control
the chemical composition of positive ions in the ionosphere  under
certain assumptions about reaction rate coefficients nitrogen is
substantially dissociated in the f region to the theoretical conclusions
of other investigators
   /
9375
a preliminary mode for the variations of upper air densities  a model
is proposed covering variations of density with a period greater
than one day  the highest parts of the ionosphere  the text is given
of the symons memorial reviewing current theories concerning the
formation and structure of the ionosphere above
   /
9376
incoherent scattering by free electrons as a techniqe for studying
the ionosphere and exosphere some observations and theoretical considerations
observations confirm the existence of the incoherent scatter
at predicted levels bu  indicate less doppler broadening than expected
for which an explanation is offered
   /
9377
a possibility for determining the existence of a permanent form of
magnetic field aligned ionization irregularities  incoherent scatter
from a direction perpendicular to the earths magnetic field is discussed
   /
9378
internal atmospheric gravity waves at ionospheric heights  irregularities
and irregular motions observed in the upper atmosphere are interpreted
in terms of a spectrum of waves propagated upwards and modified
to produce different dominant modes at different heights
   /
9379
vertical characteristics of travelling ionospheric disturbances
a comparison between the occurrence of disturbances on fixed frequency
records and profiles for the same period reveals that there appears
to be an upper limiting height for the occurrence of disturbances
on fixed frequency and the direction of travel of disturbances is
related to season only and seems unrelated to height in the ionosphere
   /
9380
the analysis of night time records  a correction of electron density
profiles for errors due to underlying ionization by the use of the
extraordinary ray
   /
9381
theoretical world curves of maximum f ionization part  a time dependent
solution of the continuity equation including vertical diffusion
of ionization is used to obtain a theoretical variation of maximum
f layer electron density with latitude and local time  some similarity
to experimental data is found but the equatorial trough does not
occur in the theoretical solution  see also of
   /
9382
on the influence of horizontal motion of the neutral air on the diffusion
equation of the f regin  the equations of motion of a plasma in
applied fields are discussed with reference to the f region  the
plasma sets the neutral air into motion horizontally within about
but is not free to move vertically  the consequences of this result
on a world wide scale are discussed
   /
9383
movements of the f layer of the ionosphere during geomagnetic bay
disturbances  the vertical movement of the f layer during and after
geomagnetic disturbances i evaluated from ionospheric soundings made
at lindau germany  the movement is treated theoretically on the basis
of the plasma theory developed by lucas and schluter of and to account
for the rise of the layer use is made of martyns theory allowing
for the influence of the neutral gas  by comparing calculated and
measured data estimates of conductivity and neutral gas density in
the ionosphere can be made
   /
9384
the occurrence of the spread f and the geomagnetic field  spread
f is more probable in days after a sudden commencement at high latitudes
and less probable at low latitudes especially at the equinoctial
seasons  there is a strong correlation between the magnitude of the
geomagnetic field and the occurrence of spread f at low latitudes
a turbulence mechanism is suggested to explain this
   /
9385
measurement of positive ion density in the ionosphere by sounding
rocket  preliminary results are given of measurements made over the
akita rocket range japan in september  two rockets were launched
one during the daytime and one at night each equipped with a spherical
langmuir probe  ascent and descent records for each flight show close
agreement and values of l electron density scaled from records agree
fairly well with those obtained from rocket measurements
   /
9386
vertical incident doppler inoogram  an improved apparatus has been
constructed for the measurement of doppler shifts produced by vertical
movements of the ionosphere
   /
9387
contribution to an investigation of ionospheric absorption on a fixed
frequency  a thesis concerning theoretical and experimental aspects
of ionospheric absorption mes measurements by vertical incidence
sounding  measurements made on a frequency of during the period september
march are analysed
   /
9388
determination of ionospheric absorption from recordings of field
strength and cosmic noise  brief descriptions are given of a method
of determining the ionospheric absorption index from oblique incidence
recordings and of the riometer method using extraterrestrial noise
sources
   /
9389
statistical study in the occurrence of polar blackouts  the distributions
of radio blackouts in both hemispheres are examined using data
at stations in the north and stations in the south  the changes of
blackout occurrence and times of maximum occurrence frequency with
pso position are studied
   /
9390
a theoretical model of electron density distribution along a geomagnetic
line of force in the exosphere  a model of electron density in the
exosphere is set up by supposing electrons to diffuse along tubes
of force  electron densities in ionosphere and exosphere are related
by steady state solutions  the particle source is in the ionosphere
under normal conditions but during a magnetic storm particles are
injected into a tube of force at its furthest point from earth  the
role of collisions is discussed
   /
9391
a note on the disposition of daytime auroral ionization in space
radio aurorae are classified into two groups according to latitude
spread  the properties are compared and their relation to diffuse
and discrete aurorae is discussed
   /
9392
the slant e echo a high frequency auroral echo  the slant e d echo
is associated with vhf auroral echoes  it is formed by scattering
from randomly distributed field aligned irregularities and is enhanced
by least time focusing and aspect focusing
   /
9393
temporal variations of auroral radio echo activity in subauroral
latitudes  the diurnal day seasonal and year variations in the occurrence
f of radio aurorae are investigated and also the time delay between
class flares and the appearance l of aurorae is measured  the bimodal
diurnal distribution may be a consequence of the specular reflection
properties of the auroral echoes
   /
9394
auroral radio echoes and magnetic disturbances  the occurrence of
radio echoes from aurora is strongly correlated with local k index
the position and motion of individual echo regions correspond closely
with the current systems causing magnetic disturbances
   /
9395
space research  contains the text mainly in english of the scientific
papers presented at the first international space science symposium
nice
   /
9396
an atlas of oblique incidence ionograms  the atlas is published as
nbs technical note no and contains routine records for the paths
washington st louis washington boulder  a discussion of equipment
is given and seasonal variation layer formation and disappearance
spread echo extension and other phenomena are illustrated
   /
9397
a kilowatt microsecond vacuum tube pulser  a full description is
given of a circuit designed for operation of gas discharge tubes
in plasma research
   /
9398
distribution of losses and the efficiency of different processes
in photoelectric solar energy converters  an attempt at a quantitative
analysis of essential processes
   /
9399
theory of electrochemical diodes  a theoretical analysis is given
of the behaviour of an electrochemical diode based on the equation
of diffusion of ions  the non ohmic characteristic the shunting effect
observed with a rapidly changing voltage and the rectifying action
are determined
   /
9400
a versatile forcing function generator  an electronic generator for
use with analogue computers which produces sine square triangular
ramp step or impulse functions over the range to an accuracy within
   /
9401
a successful version of the beevers macewan fourier synthesizer using
dekatron counters  a fourier synthesizer is described which allows
a possible harmonics to be specified with amplitudes ranging from
units  both positive and negative harmonic components are acceptable
see also of
   /
9402
a dielectric drum storage system  the basic theory of a dynamic electrostatic
storage system is given  experimental results with a ceramic
drum are given packing densities of were obtained wit signal ratios
of
   /
9403
designing thin magnetic film memories for high speed computers  a
storage system has been built which will store words each of bits
and which has a cycle time of
   /
9404
current operated diode logic gates  the basic logic circuits are
described and practical examples are given
   /
9405
an analogue computer for aerial radiation patterns
   /
9406
stable oscillation conditions for the magnetic film parametron  a
mathematical analysis of a parametron is given  this parametron uses
a single domain magnetic film as the core of a nonlinear nductor
absorbing energy from an alternating pump field and delivering energy
to a signal winding  graphical means of determining stability conditions
amplitudes and phases of the oscillating variables and the range
of operating frequencies are discussed
   /
9407
microwave bistable circuits using varactor diodes  using a carrier
frequency switching speed between states was less than  threshold
logic circuit with power gain is illustrated
   /
9408
symmetrical transistors as ac or dc switches and their applications
in modulator and demodulator circuits
   /
9409
an investigation of columbium as an electrolytic capacitor metal
the characteristics of capacitors prepared from are very similar
to those of ta except that the working voltages are about one third
and the dc leakage currents about double that of similar ta capacitors
   /
9410
extension of a theorem for normal passive electrical two poles in
the steady state  the theorem of which gives the terminal resistance
of a two pole network as a function of the resistances of its elements
is extended to allow for n degrees of freedom of the network satisfying
the reciprocity condition
   /
9411
the representation of coupling free branched circuits on an analogue
computer  a method is given for simulating branched circuits on an
analogue computer so that each circuit component can be varied independently
to determine its effect on circuit characteristics
   /
9412
realization of second order two pole functions with transformerless
canonical circuits by means of program controlled computers
   /
9413
the size effect of ferrite spheres  the integral equation technique
is used to derive an approximate formula for the apparent susceptibility
of a small ferrite sphere within a microwave cavity  using a variational
principle a first order estimate is obtained for the effect of a
plane wall and the effect of the size of the sphere
   /
9414
calculation of the transfer function from the magnitude of the transmission
factor  generalization ad modification of kupfmullers system
theory to eliminate certain contradictions with practical systems
   /
9415
the matrix of a recurrent network of equal quadripoles representation
of any power of a matrix  an explicit expression is derived for the
n power of a matrix representing n equal four terminal networks
in cascade
   /
9416
synthesis of electrical filters from operating parameters by means
of zolatarev fractions  design formulae are given in which special
functions are avoided by using mathematical tables of glowatzki see
of and which involve less calculation than is required using the
grossman formulae of
   /
9417
electrical wave filter with prescribed operating characteristics
calculations are simplified by the application of image parameter
theory to filter design which may outweigh the advantages of economy
in circuit components resulting from the use of insertion loss methods
exact relations are derived between the quadripole and insertion
loss characteristics of reactance quadripoles and examples are given
   /
9418
gaussian response filter design  exact data are given for the design
of both low and band pass filters having characteristics which are
nth order approximations to the perfect gaussian amplitude response
n being the number of elements in the complete filter
   /
9419
general low pass and high pass antimetric filters inserted between
equal resistances
   /
9420
filter circuits for extremely low frequencies without the use of
inductances  description of filter design procedure using double
t rc networks  passive and active filter circuits are given
   /
9421
electromechanical quadripoles as coupling filters  the equivalent
circuits of mechanical resonators and electromechanical transducers
are derived and the design of band pass filters consisting of input
and output electromechanical transducers coupled by a mechanical
transmission line is described
   /
9422
ceramic if transformers  discusses the principles of design of the
radial mode resonator as used in if circuits
   /
9423
design data for band pass ladder filters employing ceramic resonators
graphical and tabulated design data based on image parameter theory
are given for filter comprising piezoelectric disks resonating in
a radial mode with or without capacitors  the ranges of centre frequency
bandwidth and image impd impedance achievable are discussed
   /
9424
an analysis of the magnetic second subharmonic oscillator  the analysis
refers to a parametric oscillator with two ferromagnetic cores  the
steady state operation with both current and voltage pump drives
is studied to determine the values of the circuit parameters which
will give subharmonic oscillations  the experimental waveforms are
close to those predicted
   /
9425
oscillator circuits with variable parameters pheolinear oscillators
approximation formulae are given for determining pull in range and
gain of parametric oscillators sinusoidal variation of capacitance
and ao of attenuation are the cases particularly considered
   /
9426
an airborne frequency generating unit for the hf communication band
the unit gives an output frequency with channel spacing of in the
band  a variable oscillator is phase locked to a frequency derived
from a standard
   /
9427
piezoelectric excitation of quartz oscillators operating in the thickness
mode by means of a parallel field  the parallel field excitation
of at and bt cut crystals is considered and its advantages are discussed
equivalent circuits are given of two experimental oscillators
for and using cut quartz crystal resonators
   /
9428
frequency control and frequency fluctuations of the astable multivibrator
a modified multivibrator circuit is given which permits frequency
variation over the range by means of grid bias control  the causes
of fluctuations of pulse repetition frequency are investigated and
design formulae are derived for minimizing these effects
   /
9429
high frequency transistor polyphase oscillator  conditions for oscillation
of a polyphase transistor oscillator are developed from its valve
equivalent of march  experimental results show the relative performances
of single polyphase and push pull transistor oscillators and demonstrate
the superiority of the polyphase oscillator when a high power output
is required at high frequencies
   /
9430
waveguide harmonic generators  the generator suggested by hedderley
of is regarded as a multiphase rectifier circuit
   /
9431
the synthesis of high purity oscillations suitable for single sideband
receivers  a phase locked oc oscillator has its output mixed with
part of a spectrum to form an if in the region an interpolating signal
with unwanted components down is used to lock the loop  frequencies
at intervals between and are derived
   /
9432
harmonic generators for the band  description of two signal generators
covering the ranges and  they incorporate a klystron oscillator and
si diode frequency multipliers of
   /
9433
increase of the gain of a wide band distributed amplifier by compensation
of its zeros and by arrangement of the residual poles in a tchebycheff
ellipse  a set of equations is obtained for a two valve distributed
amplifier and its component values and characteristics are calculated
for a limiting frequency of  general formulae for distributed amplifiers
with any number of valves are derived  theoretical results are verified
with the aid of an experimental two valve circuit  the tchebycheff
type of amplifier is shown to have a gain greater by a factor of
than the conventional distributed amplifier
   /
9434
bandpass transistor amplifiers  a determinant method is given for
the analysis of amplitude and phase responses of tuned amplifiers
having complex internal feedback circuits
   /
9435
a wide band single diode parametric amplifier using filter techniques
an arrangement is described using parallel tuned circuits at appropriate
points along the signal line to give bandwidths up to at a centre
frequency of
   /
9436
a nondegenerate s band parametric amplifier  with wide bandwidth
band pass filters in the input ad and idler circuits are used to
give a bandwidth of at a centre frequency of  operation in four different
modes is possible
   /
9437
a nearly optimum wide band degenerate parametric amplifier  a double
resonator single diode design with bandwidth of
   /
9438
interpretation of the transmission line parameters with a negative
conductance load and application to negative conductance amplifiers
   /
9439
behaviour of thermal noise and beam noise in a quadrupole amplifier
   /
9440
a broad band tunnel diode amplifier  a first order theory for an
amplifier using tunnel diodes is presented  the series resistance
and inductance of the diodes is neglected except where stability
is concerned  the amplifier could be built using strip or coaxial
lines
   /
9441
elimination of even order modulation in rectifier modulators  the
time varying resistance function of the modulator is considered not
to be a square wave but to contain even order carrier harmonics
   /
9442
the relative magnitudes of modulation products in rectifier modulators
and some effects of feedback  the various modulation products occurring
in series shunt and ring modulators are evaluated for square wave
switching of the rectifiers assuming that the terminations are resistive
the information is used in the design of feedback modulators
   /
9443
the round travis discriminator  a reexamination of johnstones analysis
of the round travis amplitude discriminator of shows that the conditions
indicated are not those giving minimum distortion a correction is
proposed
   /
9444
thermal noise in dissipative media  to account for the spontaneous
thermal fluctuations in a general dissipative medium a current source
term is introduced into maxwells equations  the results are applicable
to nonuniform media and to media at nonuniform temperatures
   /
9445
theory of electron phonon interactions  the theory of the interaction
of electrons and acoustic phonons in nonpolar crystals has been formulated
in terms of a new set of basis states whose wave functions are
essentially bloch functions that deform with the lattice  the major
part of the interaction may then be calculated in terms of ten be
calculated in terms of the strain tensor rather than the displacement
of the lattice  a result of the theory is a generalization of the
deformation potential theorem
   /
9446
a gas discharge free in space glowing at the focus a of a radar paraboloid
an electrodeless gas discharge in a low pressure vessel was
achieved using an arrangement of two paraboloidal mirrors and coherent
em radiation at cm
   /
9447
on the relation between zener breakdown and residual resistance in
crystals  the theory of zener breakdown in crystals is extended to
the case of very strong electric fields
   /
9448
energy dissipation and secondary electron emission in solids  experiments
show a proportionality between secondary electron yield and energy
dissipation by incident electrons
   /
9449
contribution of back scattered electrons to secondary electron formation
the contribution observed was large even in materials of low it
was in for electrons
   /
9450
pulse conduction in decaying plasma  apparatus has been constructed
in which plasma ionized by ry rf excitation is subjected to repeated
submicrosecond c voltage pulses immediately after excitation is removed
the current is measured
   /
9451
generation ad measurement of highly ionized quiescent plasmas in
steady state  a simple generation technique is described  experimental
results validate double ambipolar diffusion in homogeneous dc magnetic
fields and give a recombination coefficient of plasmas below
   /
9452
drift velocities of slow electrons in helium neon argon hydrogen
and nitrogen
   /
9453
electromagnetic interaction of a beam of charged particles with plasma
the theory of growing plasma waves is generalized to include waves
propagated in directions other than the beam direction
   /
9454
a method for measuring high electron densities in plasmas  it is
proposed that the standing wave pattern produced by plane microwaves
at the plasma boundary be measured to give the complex reflection
coefficient which is related to the electron density and collision
frequency
   /
9455
diffusion of plasma across a magnetic field
   /
9456
the influence of the langmuir stratum between plasma and container
wall on wave propagation in a plasma cable
   /
9457
field external to open structure magnetic devices represented by
ellipsoid or spheroid  mathematical expressions for the fields are
given and curves are plotted with dimensional ratio as parameter
   /
9458
the electromagnetic fields of a dipole in the presence of a thin
plasma sheet  under the assumption that the thickness of the slab
is small expressions for the resultant fields are obtained  see also
   /
9459
impedance boundary conditions for imperfectly conducting surfaces
it is shown how the exact em boundary conditions at the surface of
a material of large refractive index can be approximated to yield
the usual impedance or leontovich boundary conditions
   /
9460
propagation of electromagnetic surface wave along wedge surfaces
the conditions under which surface waves can be excited by a plane
em wave incident on a wedge are determined
   /
9461
impedance boundary conditions for statistically scalar diffraction
by a prolate spheroid at low frequencies
   /
9462
scattering by a narrow unidirectionally conducting infinite strip
expressions for the far zone fields and the first two terms in the
series for the total scattering cross section are obtained
   /
9463
back scattering from a conducting cylinder with a surrounding shell
   /
9464
scattering by a grating parts  anomalies occur in the angular spectrum
of plane waves scattered by a grating when any of the waves propagate
tangentially along the surface  this behaviour is analysed theoretically
for a wave function vanishing on the grating elements and for the
derivative of the wave function vanishing
   /
9465
nonlinear interaction of an electromagnetic wave with a plasma layer
in the presence of a static magnetic field part theory of harmonic
generation theory of propagation through an anisotropic ionized layer
as a function of incident field strength and layer thickness is presented
   /
9466
penetration of microwaves into the rarer medium in total reflection
using right angle prisms separated by a narrow air gap transmission
and reflection coefficients of paraffin sulphur and have bee measured
at as a function of the gap width
   /
9467
refraction and diffraction of pulses  a solution for reflection and
refraction of a plane pulse at a plane surface is obtained by fourier
synthesis using a method which is also valid when total reflection
occurs
   /
9468
a spectrometer for paramagnetic electron resonance with different
methods of detection  the equipment described can be used for the
klystron frea spectrometer for paramagnetic electron resonance with
different methods of detection  the equipment described can be used
for the klystron frequency modulation and magnetic sweep methods
of measurement
   /
9469
theory of ferro and antiferromagnetic resonance absorption
   /
9470
longitudinal ferrimagnetic resonance  susceptibility components are
calculated for a triangular ferrimagnetic system when the oscillating
field is parallel to both the constant field and the net magnetization
   /
9471
the relation of transition parameters for linear processes to measurable
parameters in ferrimagnetic resonance  calculated expressions include
the effect of the reaction of spin waves back on to the uniform precession
the consequences of its neglect in previous calculations by
others are discussed
   /
9472
confocal multimode resonator for millimetre through optical wavelength
masers  the mode patterns and diffraction losses are obtained for
a resonator formed by two concave spherical reflectors  these are
shown to be a minimum hen the reflector spacing equals the common
radius of curvature of the reflectors  the optical alignment is not
extremely critical
   /
9473
resonant modes in a maser interferometer  a theoretical investigation
is made of the diffraction of em waves in fabry perot interferometers
when used as resonators in optical masers  curves for field distribution
and diffraction loss are given for different mirror geometries and
different modes
   /
9474
collective excitation of electrons in degenerate bands part collective
excitations in a metallic band
   /
9475
the radio telescope for metres wavelength at the mullard observatory
the pencil beam system described is based on the principle of aperture
synthesis and has a resolution of a survey of the sky between and
declination to is given
   /
9476
the radio spectrum of the andromeda nebula  new observations have
been made and  results are compared with those made at jodrell bank
at by large et al of and show that all parts of the nebula have a
similar spectrum
   /
9477
asymmetry in the recovery from a very deep forbush type decrease
in cosmic ray intensity  analyses the intensity time curve for cosmic
rays recorded at locations all over the world  recovery occurred
at each station at the same effective local time corresponding to
arrival from directions making and with the sun earth line
   /
9478
cosmic ray flare of november  a solar flare was observed visually
at a height at least above the chromosphere during a period of increased
cosmic ray neutron flux and a burst in solar noise flux of may
   /
9479
the drift velocity of charged particles in the magnetic dipole field
a more accurate expression for the drift velocity of particles in
the vicinity of the equator is derived by allowing for a second centrifugal
force term in the original equation
   /
9480
equation of a charged particle shell in a perturbed dipole field
the equation obtained agrees with the shell measured by satellite
following the nuclear explosion of september
   /
9481
effect of hydromagnetic waves in a dipole field on the longitudinal
invariant  hydromagnetic waves of period sec and amplitude at earth
radii may cause a systematic lowering of mirror points with subsequent
loss of particles in atmospheric collisions  two models for electron
density variation along a field line are investigated  particle acceleration
by the fermi process is dominated by particle loss at mirror
points and it is suggested that only high frequency waves will give
effective acceleration
   /
9482
preliminary report on cosmic ray intensity during magnetic storms
in july  observations at three stations show that there was no appreciable
change in the primary variation spectrum for three successive
forbush decreases  this may be interpreted as an indication of a
linear superposition of cosmic ray modulation effects during the
july disturbances  for an analysis of cosmic ray intensity recorded
at mina aguilar during this period as a function of time
   /
9483
cosmic ray intensity variations during the magnetic storm in may
the primary variation spectrum has been estimated in a similar manner
to that used for the july storms above  results for both storm periods
have been compared showing a number of common features
   /
9484
some properties of radio waves reflected from the moon and their
relation to the lunar surface  the properties of the echoes are described
in terms of the correlation of the complex amplitudes of two sine
waves at frequencies separated by reflected from the surface  the
correlation technique can be extended to two dimensional mapping
of a rotating rough body  a statistical model of the lunar sunface
roughness is derived in which rms slopes of to are assumed
   /
9485
a method of evaluating the intensity of radio signals reflected from
the surface of the moon  propagation losses can be determined by
supposing that the reflected wave is formed within the limits of
the first fresnel half zone and taking account of the curvature of
the reflecting surface  the method provides a more accurate picture
of the reflection phenomena
   /
9486
some evidence of hydromagnetic waves in the earths magnetic field
combining changes in the h and d components of field indicate that
the horizontal magnetic vector is elliptically polarized  this may
be due to a hydromagnetic wave travelling obliquely to the earths
magnetic field
   /
9487
low latitude and high latitude geomagnetic agitation  detailed study
is made of geomagnetic agitation above the three daily maxima of
have spiral loci  agitation is an order of magnitude lower at middle
latitudes increasing again towards the equator  ionospheric current
systems with auroral electrojets are examined in the above context
the occurrence frequency of sudden commencements at one station exhibits
a diurnal variation  a recent theoretical explanation of this is
examined
   /
9488
on the seasonal variation in lunar and solar geomagnetic tides in
the geomagnetic equatorial region
   /
9489
influence of sunspots on geomagnetic disturbance  the hypothesis
that the ejection of solar corpuscles is influenced by interactions
of active region magnetic fields is tested empirically  the results
do not support the hypothesis
   /
9490
dipole field type magnetic disturbances and auroral activities  the
magnetic perturbation produced at the ground by the current system
associated with an electric dipole at is calculated  magneto grams
obtained during an auroral display are analysed to deduce the position
ad motion of the equivalent dipoles  these correspond closely to
prominent visual auroral forms
   /
9491
minimum range to artificial earth satellites  a complete expression
for calculating from doppler measurements the minimum passing range
between satellite and observer is derived and its application under
various orbital conditions id discussed
   /
9492
loss of mass in echo satellite  correction to of april and comparison
of predictions with observed orbital data
   /
9493
spin rate of the satellite echo as determined bya tracking radar
radar observation of echo indicate that between passes and the spin
rate increased from to rev min  between these two observations the
satellite first started passing into the earths shadow which possibly
resulted in changes in internal pressure and subsequent deformation
of the baloon
   /
9494
new satellite tracking station in great britain
   /
9495
magnesium and calcium ions in the upper atmosphere of the earth
the presence of mg and ca ions was recorded by a rocket borne mass
spectrometer launched from a moderate latitude  peaks in the mg ion
concentration reaching were observed at heights of and
   /
9496
daytime and night time atmospheric properties derived from rocket
and satellite observations  a summary of the values of atmospheric
density obtained during the interval from rockets and satellites
is presented and is fitted into a model atmosphere obtained by integrating
the hydrostatic equation  a general decrease since in atmospheric
density at all z altitudes is confirmed
   /
9497
rocket electron density measurements at fort churchill canada  a
discussion of the results of a rocket flight during quiet ionospheric
conditions using the two frequency phase comparison technique of
seddon of
   /
9498
longitudinal and latitudinal effect of the ionosphere estimated by
observation on board the soya  values of at hourly intervals are
plotted against geomagnetic latitude for the range covered by the
voyages from japan to antarctica in december and january in
   /
9499
ionization of e layer by x rays  the total amount of solar x ray
energy absorbed within the e layer is calculated from available rocket
and absorption measurements  only x rays in the wave length region
are absorbed the amount of energy involved being estimated at
   /
9500
some observations of the occurrence and movement of sporadic e ionization
an analysis of simultaneous observations of clouds in europe
by ionosondes at various locations by a rotating aerial back scatter
sounder at slough england and by an oblique propagation experiment
at over  the mean cloud diameter was about  about twice as many clouds
occurred to the south of slough as to the north with an average duration
of hu hours  of clouds one third drifted predominantly to the south
west at a mean speed of  the movement of the clouds did not correlate
with wind velocities
   /
9501
the f layer at sunrise  observations at cambridge and slough show
that at fixed heights in the f region just after layer sunrise the
electron density increases faster in winter than in summer and faster
at sunspot maximum than at sunspot minimum  it is postulated that
seasonal changes of atmospheric composition alter the rates of electron
production and loss thereby causing both the noon and sunrise seasonal
f layer anomalies
   /
9502
diffusion of ionization in the sunrise f layer  some idealized calculations
support the assumption made in above that the rate of increase
of f region electron density just after sunrise depends primarily
on the rate of production of ionization  at this time the loss diffusion
and transport of ionization are of secondary importance
   /
9503
travelling disturbances in the f region over waltair  a description
is given of the general diurnal and seasonal characteristics of travelling
disturbances as observed on and records extending over two years
   /
9504
simultaneous observations of pulsations in the geomagnetic field
and in ionospheric absorption  on and september at regular pulsations
were recorded simultaneously on a riometer operating on a frequency
of and a magnetometer measuring the h component of the geomagnetic
field  for many cycles the pulsations remain in phase but on occasions
they are in antiphase the period of the geomagnetic pulsations suggests
that they are due to toroidal hydromagnetic oscillations of the outer
atmosphere possible connections with ionospheric absorption are briefly
considered
   /
9505
analysis of the variation of e and index of solar activity  it is
assumed that for both the diurnal and annual changes in the critical
frequency is proportional to cos  the values of are extrapolated
to for several stations and an empirical relation between the values
for and the sunspot number is derived
   /
9506
vertical drift in the e layer of the ionosphere during geomagnetic
disturbances  the velocity is estimated of the vertical drift due
to geomagnetic disturbances  the possible rise of the e layer is
shown to be a few hundred metres only which cannot be measured by
ionospheric recorders  for an investigation of f layer movements
see of june
   /
9507
active high frequency spectrometers for ionospheric sounding part
direct recording of ionospheric characteristics  on the basis of
the method noted earlier of equipment has been designed which provides
direct records of and as a function of time  sample records are reproduced
and applications of the method are discussed  a method of distinguishing
height ranges in f layer records using colour film is noted
   /
9508
analysis of random fading records
   /
9509
measurement of the ionospheric absorption during the igy at kokubunji
the diurnal variation in absorption shows an asymmetry about noon
which is attributed to the changes in vertical drift motion in the
d layer associated with the current system  the marked winter anomaly
effect cannot be explained by a change in the electron density distribution
in the normal d layer
   /
9510
ionospheric motions observed with high frequency back scatter sounders
techniques for determining the characteristics of movements of irregularities
in the f region by the use of back scatter records are described
the results of an analysis of back scatter data obtained during december
at sterling virginia at a frequency of about are presented and found
to be in good agreement with those of other investigators of ionospheric
motions
   /
9511
effect of the magnetic field in ionospheric back scatter  back scatter
spectral lines may be used to calculate magnetic field ion mass and
plasma temperature  see also
   /
9512
high frequency radio wave blackouts at medium and high latitudes
during a solar cycle
   /
9513
theory of auroral morphology  the theory is based on the production
of instabilities in electron sheets  it predicts observed features
relating to the duration of homogeneous arcs and the transition from
glow to homogeneous arcs to ray arcs and draperies  other observations
explained are certain phenomena in flaming aurorae and the lowering
of mirror points in certain conditions
   /
9514
reply to some comments by malville concerning the midnight auroral
maximum  the preponderance of aurora near magnetic midnight is discussed
   /
9515
the relationship between unique geomagnetic and auroral events  at
eleven canadian stations a high correlation is found between the
geomagnetic latitudes of the southern extends of aurorae and the
most southerly current lines  a southward drift occurs simultaneously
in an aurora and the accompanying ionospheric currents
   /
9516
relationship between red auroral arcs and ionospheric recombination
an aurora arc observed photometrically to be north of boulder colorado
has been identified with oblique echoes on ionograms taken near boulder
   /
9517
generation of very low frequency noise in the exosphere by the cerenkov
effect  the cerenkov effect produced by relatively slow moving particles
of solar origin is considered as a possible mechanism for the generation
and propagation of vlf noise  the theory is briefly discussed in
relation to a travelling wave tube model proposed by gallet of to
explain similar vlf emissions
   /
9518
energy fluxes from the cyclotron radiation model of vlf radio emission
comment on a paper by santirocco of
   /
9519
classification of the waveforms of atmospherics  a review with references
   /
9520
the determination of the distance of atmospherics from their waveform
diagrams facilitating the determination of the distance of atmospherics
are given their use is discussed with reference to the results of
measurements  a reflection height of was assumed for daytime conditions
and for night time propagation
   /
9521
guidance of radio whistlers by the earths magnetic field  in an anisotropic
medium there is for each frequency an emission angle of such
a value that the ray propagates strictly along the line of magnetic
force with a velocity which is independent of frequency
   /
9522
remarks on the annual and diurnal variations of the occurrence of
whistlers  the annual variation of whistler density observed at kuhlungsborn
appears to be correlated with the thunderstorm activity of
south africa and not with that of the conjugate point which is at
a higher geomagnetic latitude  nocturnal variations of whistler density
show phase differences between summer and winter which are attributed
to absorption in the lower ionosphere
   /
9523
the hydrogen ion effect in whistler dispersion  careful analysis
of four low altitude whistlers shows deviations at low frequencies
from the law const this observation is explained in terms of a simple
atmospheric model in which the gas above about is mainly hydrogen
   /
9524
initial results of a new technique for investigating sferic activity
the system was developed for the automatic measurement of the complex
spectral characteristics and for the au  omatic high speed processing
of statistical data  typical results are presented and discussed
   /
9525
the change of state crystal oven  the action of the oven depends
upon the constancy of the melting point of crystalline material
and the thermal ballasting due to the latent heat of fusion  an oven
of this type can restrict the frequency shift to parts in for a temperature
change of
   /
9526
precise frequency control for a rotary converter  the royal research
ship discovery has been provided with a power supply whose frequency
is precise to approximately part in by locking the phase of a small
rotary convertor to that of a reference signal derived from a quartz
crystal oscillator
   /
9527
detailed balance limit of efficiency of pn junction solar cells
a theoretical upper limit for efficiency is deduced assuming that
recombination is entirely radiative  maximum efficiences of are found
   /
9528
characteristics of a high solar conversion efficiency gallium arsenide
pn junction  spectral emissivity and response data are given for
photocells which have an open circuit voltage of about and short
circuit current density cm
   /
9529
the choice and design of dc convertors  the design of single and
two transformer converters using transistors is discussed and their
performances are compared  design steps are indicated and two practical
examples are given
   /
9530
power semiconductor ratings under transient and intermittent load
methods of calculating maximum allowable dissipation are discussed
with examples
   /
9531
transient thermal impedance of semiconductor devices
   /
9532
a new dc level control for adaptive systems  a novel electronic circuit
is described and analysed which maintains the potential drop across
a load constant to within a fraction of while permitting the dc level
of the load to be varied through a wide range  the circuit requires
only standard tolerance electronic components and high precision
is obtained by an error compensation technique
   /
9533
accuracy and limitations of the resistor network used for solving
laplaces and poissons equations  the accuracy of a resistor network
is higher than that of the best comparable electrolyte tank  improved
methods of simulating boundary conditions are described
   /
9534
storing decimal digits with one clock pulse  a method based on the
magnetization time of ferrite cores
   /
9535
transistorized electronic analogue multiplier  a four quadrant circuit
using the exponential characteristics of the input of grounded base
junction transistors is described  the performance compares favourably
with that of other types
   /
9536
solving design problems in all magnetic logic  a survey of general
problems and methods of design of magnetic logic circuits excluding
parametron and ferroresonant circuits
   /
9537
discrete analogue computer compensation of sampled data control systems
a description of operational m amplifiers and si diode switches for
performing the basic functions of sampling holding and time delay
performance is analysed and an arrangement for avoiding saturation
in a feedback system is also described
   /
9538
tin oxide resistors  the characteristics of thin oxide films are
discussed and techniques of manufacture and performance figures of
tin oxide resistors for various applications are given
   /
9539
rf switching circuits and hybrid ring circuits used in radio astronomy
low loss i diode and other switching systems used in comparing small
rf noise powers are described
   /
9540
designing avalanche switching circuits
   /
9541
the equivalent wave source  the application of wave parameters to
two terminal sources is discussed  an equivalent wave source is derived
which corresponds to the conventional equivalent voltage or current
source
   /
9542
the law of small variations in characteristics and its application
to nonlinear and linear networks  current changes resulting from
small variations in characteristics in nonlinear dc networks can
be calculated approximately by reference to an equivalent circuit
examples of linear networks considered are a wheatstone bridge circuit
and reactance two poles
   /
9543
the realizability conditions for the impedance functions of electrical
two pole networks allowing for losses in coils and capacitors
   /
9544
some energy relations for rc networks  certain relations are established
and associated with the compact rc network whose open circuit impedance
parameters have residues that possess the same ratio at corresponding
poles
   /
9545
non ideal gyrators  the analogy between non ideal gyrators and non
ideal transformers is established  equations are derived for the
perfect gyrator and the gyrator with leakage matching and directional
characteristics are discussed
   /
9546
the effect of tolerances in the elements of image parameters filters
   /
9547
the insertion characteristics of cascaded circuits  a method of dealing
with series connected filter circuits in particular those consisting
of electromechanical elements is considered  a single quaripole is
derived to represent cac cascade connected equal and symmetrical
quadripoles and different types of end section are added to this
equivalent quadripole  the impedance matrix of the equivalent network
is determined the application of the principle to a combination of
unequal quadripoles is outlined
   /
9548
piezoelectric ceramic transformers and filters  a description of
some of the types of transformers and filters which are produced
from the lead zirconate lead titanate series
   /
9549
magnetostrictive transducers as selective quadripoles  the relations
between electrical and mechanical quantities in magnetostrictive
energy transducers are given and equivalent circuits derived  design
formulae are obtained using image parameter theory
   /
9550
some comments on narrow band pass filters
   /
9551
the measurement of the characteristic values of electromechanical
coupling filters
   /
9552
quadripole networks for phase correction in low pass and band pass
amplifiers  the design of delay equalizers for television transmission
systems is described
   /
9553
bodes variable equalizer  design procedure for ar an equalizer in
which the insertion loss characteristic can be varied by the variation
of one network element a thermistor is developed from basic theory
   /
9554
coupling of multipoles represented as a wave transmission problem
the method of solving multiple coupling problems by means of a scattering
matrix is described
   /
9555
network synthesis with negative resistors  the theory is presented
of the incorporation of the negative resistor as a basic circuit
element in problems of linear network analysis and synthesis nine
circuit theorems are given
   /
9556
note on coherence vs narrow bandedness in regenerative oscillators
masers lasers etc
   /
9557
a method for generating signals of arbitrary yet frequency independent
phase differences  two balanced peak detectors are used  the phase
difference remains constant over a range
   /
9558
improvement of the frequency stability of a high frequency oscillator
frequency modulated by means of a condenser microphone  a frequency
stabilizing system is described in which the condenser microphone
serves simultaneously for frequency modulation and as an es control
element  the system finds application in miniature vhf transmitters
and eliminates the need for crystal control
   /
9559
high frequency oscillator stabilization by pulse counting techniques
a system is described for frequency stabilization to within parts
in the range using an lc tuned oscillator locked to a standard frequency
a description of the trochotron divider used in the circuit is
given
   /
9560
quality measurements on oscillator crystals by the decay method
equipment is described for measuring the time constant of the decay
of free oscillations of quartz oscillators  the method is suitable
for measuring the q factor of crystals of high resonance frequency
   /
9561
and nanosecond carrier pulses produced by harmonic generation  pulses
are generated directly from the harmonics present in the sharp step
at the end of the recovery transient of a selected type diode which
is mounted across a waveguide used as a high pass filter
   /
9562
a simple method of generating nanosecond pulses at x band  the technique
is based on the pulse response of a travelling wave tube
   /
9563
magnetic gate circuits controlled by high frequency signals  principles
of operation of three and four core gating circuits based on the
nonlinear properties of parametron type cores are described  experimental
characteristics and applications are noted
   /
9564
high efficiency variable reactance frequency multiplier  a conversion
efficiency of was obtained using variable capacitance diodes with
input frequency of and output frequency mc
   /
9565
stabilized delay circuit provides high accuracy  a transistorized
circuit is given providing delays up to with a high degree of accuracy
and stability
   /
9566
electrically variable time delay using cascaded drift transistors
eight cascaded transistors provide a variation of delay of with a
minimum cut off frequency of
   /
9567
parametric up converter tunable over an frequency band  by using
an adjustable x band pump frequency a gain of is obtained with signal
frequencies ranging from to mcs
   /
9568
two simple estimates for overshoot and group delay  approximations
relating to the transient response of cascade connected quadripoles
   /
9569
low noise amplifiers for centimetre and shorter wavelengths  a summary
of the techniques used to make low noise amplifiers  the devices
covered are travelling wave tubes parametric amplifiers tunnel diodes
masers photon counters and photosensitive detectors
   /
9570
calculations of distortion and interference effects in transistor
amplifier stages on the basis of the equivalent circuit diagram
low frequency conditions and input signals up to maximum permissible
amplitude are considered and the calculations are applied to two
stage circuits  the extension of the theory to high frequency conditions
is indicated
   /
9571
improving gain control of transistor amplifiers  better temperature
stability and z lower noise figure are obtained by using separate
agc loops for each stage
   /
9572
proposal for a pulsed ferromagnetic microwave generator  spin precision
is induced by rotating the applied field from a metastable to a stable
magnetizing direction
   /
9573
stimulated emission from gas maser observed at  is considered as
an alternative to for a gas maser  the relative position and strength
of the absorption lines are shown and the construction of the proposed
maser is described
   /
9574
beam maser for millimetres uses hydrogen cyanide  a practical description
of the development and construction of a maser operating at which
may be useful as a power source amplifier or as a frequency standard
   /
9575
an operational ruby maser for observations at centimetres with a
foot radio telescope  details are given of a preamplifier weight
for mounting at the focus of a reflector  an automatic gain stabilization
system is incorporated  total input noise temperature of the radiometer
is with gain stabilization and without
   /
9576
a variable dual reactance travelling wave parametric amplifier  g
two transmission lines are coupled together by inductance and capacitance
which vary at a pump frequency
   /
9577
k band ferrite amplifier  a parametric amplifier using a sphere of
garnet and giving gain at
   /
9578
parametric amplification by charge storage  both parametric amplification
and subharmonic oscillation can be obtained through charge storage
effects suing the circuit described
   /
9579
c band nondegenerate parametric amplifier with a bandwidth  the amplifier
uses two si pill varactor diodes in a balanced circuit and has
a gain of db
   /
9580
parametric excited resonator using junction transistor  oscillations
in the collector circuit are phase locked by a signal applied to
the reverse biased emitter
   /
9581
a matched amplifier using two cascaded esaki diodes  a circuit consisting
of a quarter wave transmission line whose ends are terminated
by negative conductances is discussed and its characteristics calculated
a amplifier using two esaki diodes has been found to have a gain
of with a noise figure of
   /
9582
general relativity for the experimentalist
   /
9583
direct determination of boltzmanns constant from resistance noise
the value of obtained frl from thermal noise measurements in the
frequency range is joules degree to an accuracy within
   /
9584
friedel sum rule for a system of interacting electrons
   /
9585
theory of the magnetoresistance effect  magneto resistance effects
in metals are studied on the basis of a single quantum theory of
electron transport in a magnetic field
   /
9586
response of a thermocouple circuit to non steady currents  a general
expressions for the transient response is derived and applied to
several special forms of time dependent current
   /
9587
note on the mechanism of the multipactor effect  by modifying the
theory of m krebs to take into account the velocity distribution
of secondary electrons and the phase defocusing effect excellent
agreement is obtained with the experimental results of hatch and
williams of
   /
9588
determining electron density and distribution in plasmas  a microwave
interferometer technique is used for measurements on low temperature
magnetically contained plasmas
   /
9589
transport coefficients of plasmas in a magnetic field  the electrical
and thermal conductivities and the coefficient of thermal diffusion
are calculated
   /
9590
proposed diagnostic method for cylindrical plasmas  expressions are
derived for two methods whereby the electron density variation across
a plasma column can be obtained more easily than hitherto from an
observed diffraction pattern
   /
9591
microwave attenuation by cyclotron resonance in a slightly ionized
gas  the boltzmann equation is solved for the distribution function
of electrons in a static magnetic field b and a hf electric field
the tensor dielectric constant and propagation constant k are hence
obtained  the attenuation spectrum is discussed for the two cases
of parallel and perpendicular to b
   /
9592
spectrum of the electron synchrotron resonance in a plasma  experimental
verification of a theoretical formula for cyclotron resonance frequency
   /
9593
heating of an ionized gas sheath by microwaves  formulae are derived
from which the temperature of a plasma sheath can be found as a function
of time when it is heated by high energy microwave radiation
   /
9594
backward wave microwave oscillations in a system composed of an electron
beam and a hydrogen gas plasma  a travelling wave interaction structure
is used to investigate the properties of a low density plasma  microwave
oscillations near the electron cyclotron frequency are observed as
the result of growing waves in a beam plasma interaction  electron
ction electron densities determined by observing the correlation
between the measured frequencies of oscillation and the theoretical
predictions of trivelpiece and gould of are verified by observation
of the shift in the resonance frequency of a microwave cavity containing
the plasma
   /
9595
the influence of the cross sectional distribution of electron density
of a longitudinally magnetized plasma in a metal waveguide on the
propagation of em waves
   /
9596
the magnetization and field of rod shaped objects  the magnetization
process is analysed and general formulae are given for the demagnetizing
field  an electron optical method of for determining the magnetic
distribution in and around the rod is discussed
   /
9597
determination of the energy of a plane magnetic field by representation
f the latter in an electric current field
   /
9598
equipment for generating strong magnetic fields f short period constancy
a suitably terminated low pass filter network is used to produce
flat topped current pulses for generating strong magnetic fields
which are constant for periods of the order of
   /
9599
a dipole absorber for centimetric electromagnetic waves with reduced
reflection at oblique incidence  the addition to a resonance absorber
of arrays of dipoles parallel and perpendicular to the absorber surface
minimizes reflection at oblique incidence experimental results and
theory are given
   /
9600
multiple scattering by a random stack of dielectric slabs  when the
number of slabs is large the neumann series for the mean square transmission
and reflection coefficients converges much more rapidly than
would be inferred from the smallness of the perturbation of the incident
field by the scattering medium
   /
9601
detection of double resonance by frequency change application to
hg  feb
   /
9602
the three level gas maser as a microwave spectrometer  a method of
microwave spectroscopy using three level maser action is described
and results of experiments on hdco are discussed in relation to theory
   /
9603
distribution of fields from randomly placed dipoles free precession
signal decay as result of magnetic grains
   /
9604
ferromagnetic relaxation caused by interaction with thermally excited
magnons
   /
9605
note on the back reaction term in ferromagnetic relaxation equations
a clarification is given of the status of the last term of the equation
proposed to a paper on the analysis of ferromagnetic resonance line
width in ferrites of and
   /
9606
on the theory of spin lattice relaxation in paramagnetic salts
   /
9607
spatial coherence in the output of an optical maser
   /
9608
optically efficient ruby laser pump
   /
9609
note on the magnetic structure of the galaxy  a resessment of earlier
theory see of march
   /
9610
a comparison of three surveys of radio stars  a recent survey of
radio stars is compared with results of earlier measurements by mills
et al and edge et al
   /
9611
first results of radio star observations using the method of aperture
synthesis  four surveys centred on declinations of and have been
made at a wavelength of with a large interferometric radio telescope
based on the technique of aperture synthesis of ryle and hewish
details of the observational method calibration data reduction and
analysis of the computed results are given
   /
9612
observations of some radio sources on cm  a report of observations
of discrete rf sources taurus a orion cygnus a and cassiopeia a made
during june with a radio telescope
   /
9613
rf switching circuits and hybrid ring circuits used in radio astronomy
   /
9614
an operational ruby maser for observations at centimetres with a
foot radio telescope
   /
9615
on the relativistic electrons in the solar atmosphere  the ejection
of relativistic electrons in association with flares is discussed
and the loss of energy of these electrons through synchrotron radiation
is related to type rf bursts
   /
9616
the surface brightness of radio sources at galactic latitudes greater
than
   /
9617
the relation between the optical and radio magnitudes of galaxies
a statistical relation is found from observations of sources
   /
9618
a radio wave mechanism to account for the known distribution of van
allen belts about the earth  a mechanism based on a conducting spherical
earth illuminated by em and corpuscular radiation from the sun is
given to account for the positions of the van allen belts  interference
between back scattered and incident radiation exhibits resonance
peaks in a standing wave pattern in which peaks solar particles are
trapped
   /
9619
motion of low energy solar cosmic ray particles in the earths magnetic
field
   /
9620
cosmic noise measurements from at  noise field strengths are given
as measured in the satellite for positions in both hemispheres
   /
9621
a new determination of the solar parallax by means of radar echoes
from venus  the value of arc obtained for the solar parallax is compared
with values obtained by other workers
   /
9622
the time variations of solar cosmic rays during july at minneapolis
baloon observations with ion chambers geiger counters and scintillation
counters of solar cosmic rays accompanying three large solar flare
are reported  correlation with magnetic data is given and proton
energy spectra are calculated
   /
9623
the high energy cosmic ray flare of may high altitude ionization
and counter measurements  measurements of cosmic rays from a solar
flare are reported  various types of counters were used in a balloon
the rate at which the particle flux decreased with time is compared
with neutron flux measurements at the ground
   /
9624
the high energy cosmic ray flare of may part emulsion measurements
nuclear emulsions recovered from a balloon give the energy spectrum
of the cosmic rays  excess flux was observed of protons in the range
above
   /
9625
experimental analysis of magnetic and telluric effects of the argus
experiment recorded at french stations  recordings made at six stations
have been analysed  results are produced in tubular form and photographic
reproductions of typical records are given
   /
9626
the steady state of the chapman ferraro problem in two dimensions
the form of the cavity in the plane of the dipole and uniform solar
stream is derived using the method of complex potentials  large scale
electron bombardment of the atmosphere at the sudden commencement
of a geomagnetic storm  x ray bursts coincident in time with two
sudden commencement peaks in magnetic records were observed with
balloon borne geiger counters  ionospheric absorption data are given
an estimate is made of the electron flux required to account for
the x ray intensities and their origin is discussed
   /
9627
solar stream distortion of the geomagnetic field and polar electrojets
the geomagnetic field distortion may introduce longitudinal field
gradients which will lead to electrojet current systems of the form
observed
   /
9628
radiation from a current filament above a homogeneous earth with
application to micropulsations  near field considerations are used
to steady the radiations at micropulsation frequencies from an ionospheric
current
   /
9629
the diurnal variation of k indices of geomagnetic activity on quiet
days in  local tim and universal time components are derived from
the k numbers from six observatories in moderately low latitudes
   /
9630
measurement of the temperature in the upper atmosphere to in a rocket
experiment  spectroscopic observation of sunlight reasonantly scattered
from a sodium cloud formed by ejection of sodium from a rocket gave
atmospheric temperatures between and
   /
9631
the motion of the third soviet cosmic rocket  an investigation of
the motion of lunik from october to march  results are summarized
in tabular form
   /
9632
satellite orbits about a planet with rotational symmetry  an approximate
closed form solution of high accuracy and without restriction on
the inclination angle or eccentricity is obtained for the equations
of motion of an earth satellite
   /
9633
satellite orbit perturbations in vector form
   /
9634
the doppler effect and inertial systems  the minimum range equation
for the general case of curved orbits of satellite and observer is
compared with the equation valid for inertial systems
   /
9635
instrumentation for the first anglo american scout satellite  the
satellite is primarily designed for studies of the ionosphere  the
techniques for measurement of electron density and temperature ion
mass solar x rays and lyman flux are described
   /
9636
earth satellites and geodesy  examination of possible methods for
determining geocentric coordinates of points on the earths surface
from observations of the moon and artificial earth satellites  the
determination of the difference between ephemeris and universal time
is considered
   /
9637
determination of position on the earth from a single visual observation
of an artificial satellite  if a reliable orbit is available and
an observation of the satellite against a background of of stars
can be made to an accuracy within and timed to the position of the
observer can be determined with sufficient accuracy for navigation
purposes  a single visual observation of echo provides the reference
in a worked example
   /
9638
ground equipment for radio observations of artificial satellites
   /
9639
design and results of first tests on a camera with a moving film
for the photography of faint artificial satellites
   /
9640
air density variations in the mesosphere and the winter anomaly in
ionospheric absorption  the air density variations observed in winter
by jones et al  may indicate air movements which could cause an enhancement
of the no content and give rise t in turn to increased ionization
and radio wave absorption
   /
9641
ionization loss rates below km  a discussion of the loss processes
in the d region with a review of data on the rate coefficients involved
theoretical height distributions of electrons and of positive and
negative ions are given
   /
9642
world maps of f layer critical frequencies for the solstice and equinox
months of and  hourly world maps of are analysed as a function of
solar activity  results show asymmetrical distribution over the two
hemispheres  discontinuous diurnal movement of world maximum ionization
and the existence of four poles in the distribution of the mean diurnal
rate of increase of ionization due to solar activity two of these
poles corresponding to the magnetic poles and the other two being
located in the equatorial belt where the geomagnetic equator is further
from the geographic equator  it is concluded that these phenomena
cannot be explained by existing theories and that the possibility
of corpuscular discharge from a van allen belt should be investigated
particularly in relation to equatorial regions
   /
9643
on the nature of equatorial spread f  transequatorial propagation
on via scattering from the f region above huancayo was closely associated
with equatorial type but not temperate type spread f on huancayo
ionograms ie range spreading not frequency spreading  the irregularities
take the form of thin sheets near the bottom of the f layer they
are elongated in the direction of the earths field being or more
in length and of the order of in at least one dimension transverse
to the field  it is suggested that equatorial spread f can occur
only when the contours of mean electron density are parallel to the
lines of force of the earths field
   /
9644
critical remarks on the calculation of true heights  the conditions
are given and discussed which permit an unambiguous solution of the
integral equation of ionospheric virtual height  practical procedures
and possible sources of error are indicated with some proposals for
improved methods of evaluation
   /
9645
the anomalous ionospheric absorption on winter days  the mean diurnal
variation is evaluated from ionospheric absorption measurements made
at geenoa during  abnormally high absorption observed in january
and february is discussed with reference to data obtained at other
stations the geographical distribution of the phenomenon and the
influence of meteors are considered
   /
9646
the ionosphere at the garchy station at the time of the eclipse of
october  ionization density for true heights ranging from to is plotted
as a function of time for the pr period results are briefly discussed
   /
9647
some results of direct probing in the ionosphere results of electron
density measurements at two frequencies using two different rf impedance
probe techniques are given
   /
9648
ionospheric electron content and its variations deduced from satellite
o observations  faraday fading observations of signals from satellite
on and have bee analysed to show diurnal and seasonal variations
of electron content from september to december  in twelve instances
a decrease in content was observed following a magnetic storm
   /
9649
a local reduction of f region ionization due to missile transit
an explanation of an unusual c echo received on local ionospheric
sounders following the firing of vanguard is given in terms of a
reduction in the ionization density at the f layer maximum  the interpretation
is extended to explain spread f and radio star scintillation
   /
9650
active high frequency spectrometers for ionospheric sounding part
selection of the echo signals from the noise background  the prior
knowledge of echo properties such as periodicity signal shape rf
phase and direction of arrival may be used to improve ionospheric
recording methods
   /
9651
the relationship of low height ionosonde echoes to auroral zone absorption
ad vhf d scatter  weak diffuse echoes are shown at heights between
and in the frequency range  the diurnal seasonal and height characteristics
of the layer indicate that it is related to auroral zone absorption
and is responsible for vhf forward scatter
   /
9652
man made heating and ionization of the upper atmosphere  absorption
of radio signals by cyclotron resonance is shown to be possible within
a very narrow layer of the atmosphere km thick just below  for a
plane polarized signal only of the power can be absorbed  better
results are obtained with a circularly polarized radio wave  the
absorbable power is limited by the effects obtained so that an electron
density of and an electron temperature of cannot be exceeded  the
reason for this is the weakness of the a earths magnetic field
   /
9653
new principle of measurement of ionospheric absorption  the mean
coefficient o absorption in the region of the ionosphere eb below
an artificial satellite may be calculated from measurements of the
signal strength of the satellite transmission received on an omnidirectional
aerial
   /
9654
the arctic ionosphere and solar activity  ionospheric conditions
at several arctic stations have been correlated with solar activity
using monthly median critical frequencies for the e f and f layers
and the month mean zurich sunspot numbers
   /
9655
a neutral line discharge theory of the aurora polaris
   /
9656
southernmost extent of aurorae according to german observations on
land and sea during the international geophysical year  results of
observations are interpreted with rf reference to data from us satellite
measurements
   /
9657
a note on auroral echoes detected at stanford following the solar
event of november  the time of transit of the auroral particles determined
from radar observations was min  a change in range of echoes
corresponding to a velocity of was also observed
   /
9658
on the origin of vlf noise in earths exosphere  the primary cause
of vlf noise in the exosphere is cerenkov radiation due to high speed
protons  the natural thermal noise and proton cyclotron radiation
effects are considered to be secondary noise sources
   /
9659
graphical methods for the determination of the distance of atmospherics
from their waveform  extension of the graphical method outlined in
of july  delay time diagrams are given for reflection heights of
and comparisons are made with tabulated meteorological data
   /
9660
determination of the direction of arrival and the polarization of
whistling atmospherics  measurements have ben made at using two pairs
of identical aerials located at the ends of perpendicular base lines
received signals were passed to a central measuring station via microwave
links  results show that the direction of arrival of the signal
makes an angle of between and with the magnetic field  polarization
is consistent with the direction of arrival observed and leads to
electron densities about ten times smaller than those given by storey
of
   /
9661
whistlers excited by sound waves  sound waves generated by a nuclear
explosion could excite transverse waves in the ionosphere capable
of propagation in whistler modes
   /
9662
power supply for the tiros meteorological satellite
   /
9663
low impedance thermoelectric device powers tunnel diodes  the power
supply described consists of of several couples in series heated
by ac or dcdriven resistance elements and having an output impedance
of  results obtained with tunnel diode microwave oscillators are
briefly discussed
   /
9664
the effect of series resistance on photovoltaic solar energy conversion
the series resistance in a photovoltaic cell is divided into two
components contact and sheet resistance  each of the components is
examined theoretically and experimentally and qualitative agreement
between theory and experiment is shown  it is concluded that contact
resistance reduces the conversion efficiency more than sheet resistance
   /
9665
considerations of photoemissive energy converters  the efficiency
of a o solar energy converter consisting of a emitter and an ag collector
is calculated taking into account the initial velocities of the
photoelectrons but ignoring space charge  efficiencies between and
are obtained for output voltages between and  the efficiency increases
as the percentage of blue and ultraviolet radiation in the source
is increased  to minimize space charge effects the emitter collector
spacing must be of the order of or less
   /
9666
optimum capacitor charging efficiency for space systems  several
theorems for the perfect time shaped source voltages which optimize
the efficiency of energy transfer from source to load are derived
the practical application of the theorems is discussed
   /
9667
lectures on electronic computing  english summaries are given of
the following papers the history of the electronic computing machine
ptera purpose and possibilities  the functioning of the electronic
computing machine ptera  programming for the electronic computing
machine ptera  discussion of programme for the electronic computing
machine tera  the complete papers are published in bedrijf
   /
9668
elimination of waiting time in automatic computers with delay type
stores  a critical survey is made of methods which have been tried
for eliminating waiting time and a description is given of a process
developed for determining the amount of waiting time eliminated
the optimum programming method adopted with the ace pilot model is
found to be a combination of several methods  it appears that reduction
of waiting time generally has to be paid for in extra complication
of programming or design some exceptions to this rule are indicated
   /
9669
applications of electronic computers to clerical work  an examination
is made of different types of clerical work and the circumstances
in which an electronic computer can be used with advantage  experience
obtained with leo the lyons equipment is discussed
   /
9670
numerical methods in digital real time simulation
   /
9671
a simple microwave correlator  the correlator described uses the
ring modulator circuit as a rapid response multiplier it accepts
signals on coaxial cables and has a wide frequency range  two types
those with positive and those with negative output pulse  applications
in the following computer circuits are described single ended electrical
delay line store shift register circuits performing logical operations
   /
9672
a versatile transistor circuit  the design is described of point
contact transistor switching circuits such that direct currents of
the order of several tens of milliamperes can be handled with a voltage
drop of only one or two volts  applications of these circuits in
a symmetrical push pull magnetic writing circuit and a shift register
are considered
   /
9673
the mechanical particle an analog computing machine  an arrangement
is described in which a mechanism guided by remote control moves
over a contour map to simulate the motion of a charged particle in
a two dimensional magnetic field
   /
9674
a method ensuring channel width stability and equality in a pulse
amplitude analyser  apparatus based on wilkinsons work has the following
characteristics channel width variable between channel stability
within for a period of operation possible channels or more according
to the type of recorder available
   /
9675
a flexible single channel pulse amplitude analyser  the instrument
described is designed for measuring the amplitude of voltage pulses
of duration by pre setting two voltage limits  it can also be used
as a simple discriminator  the complete circuit diagram is given
including details of component values valve types etc
   /
9676
computation methods for transistors and transistor circuits treated
as active quadripoles  upper and lower limits for frequency of operation
are found using experimentally determined values for the equivalent
network impedances  stability is discussed
   /
9677
raising the cut off frequency of transistors  the cut off frequency
of transistor operation is raised by neutralizing the collector capacitance
by means of inductance connected between collector and emitter
calculations of the bandwidth between the points on both sides of
the resonant frequency are made for grounded base grounded emitter
and grounded collector arrangements
   /
9678
noise in resistors  account of an extended investigation of the noise
produced by resistors carrying a c  exciting voltages were used having
magnitudes between and times the noise voltage over a narrow frequency
band the filtering techniques for separating these two voltages are
discussed  measurements on various types of resistor were made at
with excitation frequencies ranging from to and various excitation
levels  the noise varies as an inverse power of frequency up to a
feq megacycles per second beyond which it is independent of frequency
the noise in volts per cycle bandwidth depends on a power of the
applied voltage which ranges from  some composition type resistors
exhibit an increase in noise output after passing for long periods
   /
9679
component design trends precision potentiometers use new materials
use of resistance elements made from deposited metal films conductive
plastics or lossy liquid dielectrics given infinite resolution  other
new design and construction tech niques give increased life and reliability
   /
9680
dimensioning solenoids for transmitter circuits  simple formulae
and a graph based on medhursts expression for of are assembled and
their use illustrated in four worked examples
   /
9681
the effect of certain contaminants on the capacitance and losses
of pyralene impregnated paper capacitors  undesirable effects can
be eliminated by avoiding the use of resin flux in the soldering
process
   /
9682
conversion of a brune cycle with an ideal transformer into a cycle
without an ideal transformer  an alternative proof to that of bott
and duffin is given for the existence of a network configuration
without an ideal transformer corresponding to any positive real function
   /
9683
on electrical network determinants  four theorems dealing with the
relation between the loop determinant and the node determinant of
a network are presented with examples of their application
   /
9684
analysis of transmission line directional couplers  five different
types of transmission line systems are analysed and are shown to
possess directional properties at the lower radio frequencies  the
conditions of mismatch on either transmission line or on both transmission
lines have been taken into account as well as lengths of coupling
greater than a fractional wavelength  a new and more general scatter
matrix for directional couplers which includes the condition of mismatch
is developed  in addition lumped circuit directional couplers have
been developed as a consequence of the general transmission line
theory
   /
9685
the relations between circuit bandwidth and time constant  a correct
method for specifying bandwidth involves fixing a priori limits for
a response curve and considering the relation between amplitude and
phase distortion in order to determine the limits applicable under
transient conditions
   /
9686
weighting functions for time varying feedback systems  technique
is presented for analysing the response of a linear time varying
system to a step function input using an analogue computer  the method
involves synthesis of the adjoint system
   /
9687
measurement and calculation of carrier frequency transients  a carrier
modulated by rectangular pulses is passed through a transmission
system and the output is observed oscillographically the timebase
being synchronized by the pulses  the oscillogram thus displays the
envelope of outputs for different carrier phases at initiation of
the pulses  it is shown mathematically that this envelope corresponds
with the result obtained ae  theory is outlined and a survey is made
of known applications such as attenuators modulators gyrators etc
advantages and disadvantages of devices based on this effect are
compared with those of devices based on the faraday effect  deeper
understanding of the physical processes involved is necessary for
further practical development
   /
9688
molecular microwave oscillator and new hyperfine structure in the
microwave spectrum of
   /
9689
resonance absorber for electromagnetic waves  an absorber for centimetre
wavelengths consists of resonators regularly distributed over a metal
plate  the resonators are cavities containing a few milligrammes
of fe powder and absorb energy by interaction with the magnetic component
of the e m field  the impedance of the absorber depends on the
losses of the individual resonators and on their concentration a
system theoretically giving total absorption at is obtained by making
the impedance the characteristic impedance of free space
   /
9690
new null transmission networks  three frequency selective networks
are discussed a balanced lattice a variable a mutual inductance type
gives the largest off null outputs but is not easily adjustable over
a range of frequencies  an application of type for transformer testing
is described
   /
9691
the parallel t resistance capacitance network  correction to paper
abstracted in
   /
9692
the transfer function of networks without mutual reactance  extension
of analysis presented previously  the theory is applicable generally
to two terminal pair networks  synthesis procedure is illustrated
by examples
   /
9693
an electrodynamic perturbation theorem with application to nonreciprocal
systems  a modification of the reciprocity theorem is used to evaluate
the antisymmetric part of the admittance matrix of an electrodynamic
system in terms of the fields produced by the applied voltages  the
effect of system perturbations on the admittance matrix is determined
the method is applicable to and microwave gyrators as well as to
reciprocal systems but gives solutions only to a first order of approximation
   /
9694
the voltage ratio and output impedance of a ladder network composed
of similar elements  simple expressions are derived using thevenins
theorem
   /
9695
the complete specification of a network by a single parameter  if
the transfer function of a linear passive network is defined as the
output response divided by the input driving force it can be written
in iether polar of cartesian form where is the amplitude response
is the phase characteristic is the in phase component and is the
quadrature component  the transient response to a unit step function
can be determined within a constant from either alone  and are all
related and any one can be used to compute the other two  the derivation
of these relations is valid for networks with either distributed
or lumped constants including transducers and the question of minimum
phase does not arise  a graphic method is described for computing
from either and universal curves are included  equipment is described
which sweeps or a polar plot of and directly  an intensity frequency
marker circuit is included which produces multiple harmonically related
dots on the sweep response  it is also possible to sweep the departure
from phase linearity  by a heterodyne process the sweep can be used
on low pass or band pass systems
   /
9696
a new transducer diagram  a diagram is presented in which a loss
free quadripole is completely represented by two straight lines and
a point  the method is based on projective geometry and gives a visual
as well as a numerical presentation of the impedance transformation
effected by the network
   /
9697
the correspondence between ladder filters connected between a resistance
and zero or infinite impedance and ladder filters connected between
two resistances  the response curve of a quadripole defined in terms
of image parameters and inserted between two finite resistances is
determined by separating the actual insertion loss into components
the analysis is developed for the case of one of the resistances
becoming infinite or zero  alternative analysis is given for the
quadripole defined in terms of its component impedances  relations
are derived for transforming a ladder filter connected between two
resistances to a network giving the same attenuation frequency characteristic
when the source impedance is infinite or zero
   /
9698
antimetrical lattice filters  detailed treatment by image parameter
theory illustrates the complete correspondence between this class
of filter and the conventional symmetrical type  practical examples
are given and design formulae for low pass high pass and band pass
networks are tabulated
   /
9699
delay line equalizer  experimental equipment designed for low definition
television can be used either in conjunction with test signals or
on lines in service  manual adjustments are made according to the
position of the pulse on the oscillograph screen  a total delay of
is provided in steps of and the cut off frequency
   /
9700
some properties of linear networks with three pairs of terminals
and their applications in realizing negative impedances and negative
feedback amplifiers  analysis of six terminal networks based on a
generalization of thevenins theorem gives a general method of circuit
synthesis in which the prescribed impedances may have a positive
or negative real part which is independent of the gain and internal
impedance of the active element  a method of amplifier design on
this principle is illustrated in which input and output impedances
are independent of the terminations at the opposite ends
   /
9701
theory of pulling in by a small amplitude external force  a method
is developed for calculating the effect of small periodic external
forces on an oscillating system  the method is illustrated by considering
the effect of a small sinusoidal voltage of frequency on a valve
oscillator with a natural frequency the difference between the frequencies
being small
   /
9702
nonlinear study of frequency modulated oscillator  analysis is presented
to show how the nonlinear damping of the valve limits the growth
of oscillations in the case of parametric excitation thus permitting
the establishment of a stationary oscillation
   /
9703
generalized equations for rc phase shift oscillators  correction
to paper abstracted in
   /
9704
the design of a simple modulator of moderate cost  a low power pulse
generator for laboratory work designed to deliver or pulses at varying
repetition frequencies when the load impedance may vary between and
is described  since the power required is low a type thyratron with
a delay line in the anode circuit is used to drive the double tetrode
modulator stage
   /
9705
a low frequency pulse generator with independent control of pulse
shape and pulse frequency  a modified multivibrator circuit is described
in which the pulse repetition frequency is controlled by a variable
resistance in the control grid circuit of a heptode and the pulse
duration by the voltage on a second control grid the screen voltage
being stabilized  the circuit shown can be used with the photoformer
described by sunstein to generate pulses of any shape with repetition
frequency variable between and pulses and pulse duration
   /
9706
multiloop feedback amplifiers  a stability criterion is derived which
involves only one nyquist plot rational negative feedback and equalizer
circuits or servomechanisms with prescribed characteristics  the
basic feedback amplifier circuit is examined with the object of determining
the design of the transformation and feedback networks so as
to obtain a given overall frequency response for a given response
of the amplifier alone  servomechanisms and equalizers are treated
as particular cases
   /
9707
wide band amplifiers for bandwidths up to  an account is given of
amplifiers of the type using low pass filters as interstage couplings
these are superior to distributed amplifiers up to a certain frequency
the value of which is about when valves are used and with valves
a practical limit for the number of reactances in the coupling circuit
is about five further increase would call for too narrow tolerances
on the components and would greatly increase alignment difficulties
theoretical computations of the coupling circuit could not be made
accurately because of frequency variation of the components  a high
accuracy frequency sweep generator is essential for the experimental
investigations
   /
9708
the transfer function as a tool in the analysis of a resistance capacitance
coupled voltage amplifier
   /
9709
fifty watt amplifier for high quality audio
   /
9710
a hyperbolic detector  the detector considered comprises a double
triode the grids of which are in parallel the anodes in push pull
and the cathodes biased separately  the detection characteristic
will be hyperbolic if a rectangular or trapezoidal characteristic
is obtained on plotting the difference between the anode currents
against the grid voltage  the effect of varying the modulation voltage
is considered
   /
9711
space modulation of amplitude limited oscillations  simple theoretical
considerations show that demodulation can be achieved by using a
detector with rectangular characteristic  the amplitude modulated
amplitude limited signal is converted by this detector into rectangular
pulses whose width is determined by the rate of variation of the
input signal voltage  the amplitude modulation can then be detected
by using a second detector having similar characteristics
   /
9712
wide band limiter circuits for frequency modulation  a systematic
analysis with special reference to multiplex requirements  the general
characteristics of a limiter are defined and two types considered
in detail a grid limiter and a crystal diode limiter  circuit arrangements
giving best results for large bandwidths are discussed
   /
9713
magnetic amplifier circuits  recommended to all designers and users
of magnetic amplifiers
   /
9714
the decilog a unit for logarithmic measurement  difficulties resulting
from an extended use of the term decibel are discussed  suggested
new logarithmic units of ratio are reviewed  it is proposed to supplement
the decibel by introducing the decilog whose value is such that
the number of decilogs is equal to times the logarithm to the base
of the ratio
   /
9715
lowest eigenvalues of nearly circular regions  analysis relevant
to waveguides and vibrating membranes is presented  the principal
eigenvalue of the nearly circular element is found by a method involving
the circle of equal area  the usefulness of the method is illustrated
by comparing approximate values thus found for a rectangle with the
exact values
   /
9716
electrodynamics problems of non ideally conducting bodies having
angularities
   /
9717
thermomagnetic properties of thin metallic films  theory presented
by is extended to cover cases involving temperature gradients
   /
9718
electrons in lattice fields  a study of the motion of a free electron
in the conduction band of an ionic crystal taking account of the
lattice vibrations
   /
9719
ignition of electric discharge in gases by audio frequency current
in tubes with external and internal electrodes  an experimental investigation
is reported of the dependence of ignition and discharge conditions
on the frequency of the applied voltage up to  tubes filled with
or at a pressure with either plane or external annular electrodes
were used  results are presented graphically
   /
9720
interpretation of electron emission from metals and nonmetals after
mechanical working or irradiation  conflicting theories of can br
reconciled by assuming that the emitted electrons come from high
energy levels so that only small amounts of energy are needed to
enable tham to escape
   /
9721
temperature and field emission of electrons from metals  calculations
are made of emission current density and energy distribution for
surface electric field strengths between and temperatures up to and
various values of work function  the evaluation is made by numerical
integration of the known expression for the emission based on the
free electron theory of metals and the wave mechanical barrier transmission
coefficient of  results are presented graphically and are consistent
with the field emission equation for low temperatures and with
the richardson thermionic emission formula for low fields  the work
is relevant to previously reported investigations of the vacuum arc
   /
9722
backscattering of kilovolt electrons from solids  the total number
and energy distribution of backscattered electrons with incident
electrons of energy have been measured for and using retarding potential
technique  the dependence on the energy of the incident electrons
is characteristically different for elements of atomic number above
and below  the ratio fo the mean energy of the backscattered electrons
to that of the incident electrons is about for and increases only
slightly with atomic number  the results are interpreted as indicating
the inelastic processes are predominant in the scattering of medium
energy electrons
   /
9723
velocity of electron pulses  the transit time of a brief pulse of
electrons of known energy across a measured distance was determined
by an arrangement involving two deflection gates opened sequentially
for very brief intervals by a single surge travelling in a cable
an electron multiplier was used as collector  about of the electrons
arrived within of the mean transit time the most probable transit
time could be ascertained within  the apparatus can be used as a
velocity spectrograph and as a chronograph for measuring the time
of rise of very steep surges
   /
9724
theory of secondary electron cascade in metals  a study is made of
the diffusion energy loss and multiplication of secondary electrons
prior to emission  energy distributions consistent with experimental
results are derived also values for the uield and the dependence
of yield on work function
   /
9725
effect of vapours of halogen compounds on the emission of positive
ions from platinum
   /
9726
angular distribution of secondary ions on bombardment of a tantalum
plate by ions of alkali metals  an experimental investigation is
reported of the dependence of the energy and intensity distribution
of secondary and ions on the angle of incidence of the primary ions
results are presenred graphically
   /
9727
low frequency plasma oscillations  theoretical consideration of plasma
comprising both electrons and ions with maxwellian velocity distributions
shows that in the absence of an external field the low frequency
plasma oscillations decay in the presence of an applied electric
field undamped oscillations are possible
   /
9728
excitation of plasma oscillations  excitation of and plasma oscillations
bu a beam of charged particles is considered theoretically taking
account of the thermal scatter of the particle velocities  results
show that undamped and oscillations are possible in plasma with an
applied electric field
   /
9729
the attenuation of alfven waves  when the collision frequency in
an ionized gas is smaller than the wave frequency it is not permissible
to treat the gas as a continuous fluid  the equations for alfven
waves are obtained by working with distribution functions  the results
illustrate the behavior of a gas when the collision frequency is
low and may have applications in the interstellar gas or in the earths
outer atmosphere
   /
9730
a short modern review of fundamental electro magnetic theory  the
method of presenting concepts taking the inverse square law of force
between magnetic poles or electric charges as starting point is recommended
as stressing the symmetry of magnetic and electrical relations
faradays laws of induction are discussed and maxwells equations are
presented in terms of electric and magnetic flux density
   /
9731
dimensional relations in magnetohydro dynamics  an analysis is made
of dimensional relations characteristic of phenomena in fluids  in
the absence of instabilities conditions favourable for accelerating
particles to the higher cosmic ray energies can exist only when the
linear dimensions fo the fluid are very large
   /
9732
diffraction of electromagnetic waves by an aperture in a large screen
   /
9733
molecular microwave oscillator and new hyper fine structure in the
microwave spectrum of  an experimental arrangement which can be used
as a high resolution microwave spectrometer a microwave amplifier
or a stable oscillator consists of a focused beam of molecules directed
into a high oscillating cavity within which the molecules give up
energy  an emission line is seen when the excitation frequency of
the cavity is varied through the molecular transition frequency
   /
9734
radio observations of ionized hydrogen nebulae and other discrete
sources at a wavelength of  report of a second survey made during
for first survey see  preliminary results of both surveys are tabulated
   /
9735
identification of extended radio source near gemini with residual
nebula of nova flare up of  the source reported by is identified
it is predicted that on the each year the centres of the sun and
this source will be only apart and hence an eclipse will occur  this
source which subtends an angle about equal to that of the sun affords
the possibility of transillumination type observations  f the solar
corona a similar source in the crab nebula does not approach so closely
to the sun but is smaller and has a higher radio flux
   /
9736
a new type of interferometer for use in radio astronomy  a new type
of interferometer for measuring the diameter of discrete radio sources
is described and its mathematical theory is given  the principle
of the instrument is based upon the correlation between the rectified
outputs of two independent receivers at each end of a baseline and
it is shown that the cross correlation coefficient between these
outputs is proportional to the square of the amplitude of the fourier
transform of the intensity distribution across the source  the analysis
shows that it should be possible to operate the new instrument with
extremely long baselines and that it should be almost unaffected
by ionospheric irregularities
   /
9737
radio emission from the andromeda nebula  observations have been
made at a wavelength of with interferometers of different resolving
powers to determine the distribution of radio brightness accross
the nebula  the results suggest the existence of a hitherto unexpected
population of radio sources a similar population in our own galaxy
might also account for a large part of the so called isotropic component
of cosmic radio emission
   /
9738
dependence of integrated duration of meteor echoes on wavelength
and sensitivity
   /
9739
the two helix method of polarization measurement of meteoric radio
echoes  an arrangement for investigating the polarization of radio
echoes from meteors uses two helical receiving aerials wound in opposite
senses in conjunction with a helical transmitting aerial  the received
signals are combined and displayed on a operating wavelength is and
power output is  the method is applicable to sporadic meteors  results
are in good agreement with theoretical values and with measurements
made on shower meteors by
   /
9740
the solar eclipse of  brief report of observations made at about
miles of including measurements of changes in the ionosphere of radio
noise in the range and of geomagnetic field variations
   /
9741
short period fluctuations of the earths electromagnetic field  trains
of fluctuations of amplitude up to and a mean period of oscillations
in a train of were recorded simultaneously at four stations in central
asia on several hundred occasions in  the largest number of trains
was recorded between and universal time when the sun is near the
zenith of the north magnetic pole  the fluctuations could be due
to a focusing of solar corpuscular emission by the earths magnetic
field
   /
9742
index of refraction above feet  calculations are made on the basis
of refractive index measurements reported by in conjunction with
relevant meteorological data  to an accuracy within only the density
of the air has any significant effect in relation to refractive index
variations at and only at altitudes up to variations due to water
vapour content and electrons in the ionosphere are negligible  thus
for practical purposes a standard refractive index can be based on
a standard density distribution
   /
9743
origin of nitrous oxide in the atmosphere  an explanation of the
presence of nitrous oxide based on a photochemical equilibrium is
advanced the upper atmosphere  brief report of a symposium held at
at which a survey of the existing state of knowledge about the ionosphere
was given by appleton  meteor trail echo and radio star scintillation
studies were also discussed
   /
9744
ozone layer and air movements in the stratosphere
   /
9745
on new investigations of the ozone layer and its variations  various
method of investigation are discussed including use of lunar eclipses
   /
9746
recombination in the lower ionosphere  observations of phase height
polarization and absorption at are analysed to estimate the distribution
of recombination coefficient over the altitude range  theories of
recombination are examined on the basis of this distribution  recombination
during the day and during sudden ionospheric disturbances is
considered night time recombination is not dealt with  the experimental
results are consistent with negative ion theory for altitudes up
to about above the predominant process must be dissociative recombination
with an effective coefficient of about  there is no evidence of
an increase of recombination coefficient during disturbances
   /
9747
measurements in the layer with the nacy viking rocket  results of
measurements made bq are examined  a rapid increase in electron density
from altitude to near is indicated followed by a very slow increase
from electrons at to electron  at  seddons method of measurement
is capable of giving accurate results provided suitable operating
frequencies are chosen
   /
9748
on the interpretation of the apparent ionization distribution in
the ionosphere  methods of deducing the highest and lowest ionization
distributions which are consistent with a given pattern are indicated
and the sources of error when using rapid methods of analysis are
briefly discussed  some examples are given
   /
9749
electron distribution in the ionosphere  a note of methods of analysing
curves to determine electron density distribution and a procedure
for taking account of the geomagnetic field simpler than that described
by
   /
9750
charge densities in the ionosphere from radio doppler data  a method
is described whereby the directly observable radial velocities of
a missile relative to a ground receiver both in a radio doppler electronic
system of tracking may be compared to radial velocities determined
by vacuum trajectory formulae and the differences converted to ionization
densities at the levels through which the rocket is passing  this
method was used to compute ion densities for several missiles fired
at the white sands proving ground new mexico  results gave density
maximums of
   /
9751
ionospheric wind systems and electron concentrations of the layer
theory based on viscous stresses in the ionosphere leads to a simple
meridional circulation which explains observed longitudinal differences
in the electron concentration
   /
9752
the solar control of the and layers at high latitudes
   /
9753
experiments on interaction of radio waves in the ionosphere
   /
9754
a comparison of the rates of change of current in the step and return
processes of lightning flashes
   /
9755
a statistical analysis of low latitude aurorae
   /
9756
time sequences and spatial relations in auroral activity during magnetic
bays at college alaska
   /
9757
radio reflections from aurorae  analysis of auroral echoes observed
at jodrell bank indicates echoes are due to direct nonspecular reflection
from an auroral arc extending more than along a parallel of geomagnetic
latitude reflection occurs in a region of limited vertical extent
at a height of about observed movements of intense reflecting centres
represent the motion of an ionizing agent rather than a mass movement
of ionized gas
   /
9758
theory of the aurora based on magnetic self focusing of solar ion
streams
   /
9759
thunderstorm electricity  a collection of papers dealing with various
aspects of the subject most of them revised versions of papers presented
at the conference held in chicago in
   /
9760
the least squares criterion applied to linear servos
   /
9761
transient performance of servomechanisms  digest of paper published
in  a criterion of transient performance developed previously and
based on the time integral of absolute value of error is applied
to second and third order linear servomechanisms with derivate or
integral type error correction and different types of input
   /
9762
the terminology of servo systems  definitions of fundamental concepts
are given which are to be submitted by the french committee in the
revision of the international electrotechnical vocabulary
   /
9763
regulated supply has high efficiency  description of unit using magnetic
amplifiers for regulation in response to slow variations of line
voltage or load and electronic clamping circuits for regulation in
response to rapid variations
   /
9764
direct current stabilizers for electromagnets  general principles
of operation and factors affecting stability are reviewed
   /
9765
a new german differential analyser for differential equations  a
mechanical instrument built for the institute of applied mathematics
university of bonn and comprising eight integrators
   /
9766
a curve analyzer and general purpose graphical computer  the analogue
computer described comprises five photoelectric curve followers
two integrators nine adding amplifiers and a pen recorder  the independent
variable is represented by a low alternating voltage increasing
linearly with time the from of the equation is determined by the
connections between the units and the values of constants are set
by potentiometers
   /
9767
harmonic cancellation from computing voltage source in servo analogue
computers  analysis showing how harmonics of the carrier can be cancelled
out in the summing network of the servo amplifier by injecting
appropriate harmonic signals into the quadrature rejection circuit
the analysis is valid for very small phase shift  the system is advantageous
when harmonics cannot be sufficiently attenuated by filters
   /
9768
some comparisons between analogue and digital computers  the uses
of analogue and digital computers in industry are discussed and a
large scale machine of each class is described briefly
   /
9769
electronic computers and industrial mathematics  the mode of operation
of a high speed digital computer is described in functional terms
programming procedure is illustrated in relation to typical applications
   /
9770
the application of electronic digital calculating methods to punched
card machines  principles of operation and design of the electronic
multiplying punch are discussed  an outline is given of the calculating
process used for sterling and fof decimal systems
   /
9771
welded joints on diodes reduce computer bulk  diode mounting methods
are discussed teking up the least possible space while affording
adequate accessibility  by using spot welding the diode leads can
be shortened to  an elongated matrix and a honeycomb arrangement
accommodating up to diodes are among the alternatives described
   /
9772
making use of curved characteristics for the higher types of calculation
in electronic computers  where errors up to a few per cent are permissible
deliberate use can be made of the curvature of valve characteristics
in analogue computers  circuits for multiplying dividing squaring
and obtaining square roots are discussed
   /
9773
the design of an electrodynamic multiplier  development of a design
described earlier for use in a differential analyser
   /
9774
the suppression of switching transients by a shunt circuit  a detailed
analysis is presented of the phenomena occurring when apparatus including
shunt capacitance is suddenly switched across a low impedance
source of power through a short transmission line conditions for
the transient voltage in the shunt damping circuit to be nonoscillatory
are deduced  it is proved that the current through the switch can
be made unidirectional  numerical illustrations are given
   /
9775
fast single channel pulse amplitude analyser  designed for use with
proportional of scintillation counters the equipment has a channel
edge position stable to within under operation for periods up to
hours
   /
9776
description of a recording instrument  the recorder was designed
for operation with the pulse analyser described by guillon  it has
channels each comprising a decade counter and register one unit is
recorded in the channel for every train of pulses  details are given
of circuits and operation
   /
9777
migration of material in silver and platinum contacts  an experimental
investigation of deformation caused exclusively by the passage of
current
   /
9778
component design trends iron core transformers run smaller and hotter
a survey of the developments in core materials coatings and insulating
materials and of new construction methods which have in combination
made possible a reduction of size of iron core components over a
period of about ten years while permitting operation at much higher
temperatures
   /
9779
surface barrier transistor measurements and applications  circuits
for determining the transistor characteristics are described and
examples of applications taking advantage of the high frequency cut
off of the surface barrier transistor are given  these include a
two stage video amplifier for with measured power gain of at a crystal
controlled oscillator delivering conversion gain from and a non
saturating flip flop circuit with rise time and fall time
   /
9780
new resistor voltage coefficient tester  the variation of resistance
with applied voltage is determined from measurements of the third
harmonic generated by the resistor on application of a sinusoidal
voltage  the basic circuit is described and some experimental results
are given  the measurements of resistor noise at is also briefly
described
   /
9781
the design of a radio frequency coaxial resistor  discussion on
   /
9782
on the use of commercial wire wound resistors in high level video
amplifiers  by compensating the inherent inductance by means of a
parallel network commercial wire wound resistors can be adapted for
use in high power video amplifiers  practical arrangements are illustrated
and results of measurements are compared with calculated values
   /
9783
measurements on current noise in carbon resistors and in thermistors
measurements are reported on carbon and similar resistors in the
frequency range from and on negative temperature coefficient thermistors
between and  in carbon resistors the current and inversely proportional
to the square of the current and inversely proportional to approximately
the first power of frequency  in thermistors the noise level is lower
and the spectrum shows deviations from the trlation  this is in agreement
with measurements by brophy
   /
9784
calculation of iron cored inductances for direct current  a method
described by kammerloher is usitors are reviewed and design principles
are prorresponding to the optimum gap length for lamin tions of given
shape and size variation of the maximum with number of ampere turns
is investigated  examples are worked out
   /
9785
a fixed gas dielectric capacitor of high stability  factors contributing
to instability of capaced  the position of the maximum is determined
composed for parallel plate types suitable for use under laboratory
conditions  a capacitor embodying these principles is described the
performance figures indicate that a considerable gain in stability
can be achieved without serious complication in design
   /
9786
better audio specs needed  the significance is explained of technical
terms commonly used in catalogue descriptions of amplifiers loudspeakers
and output transformers and a list is fiven of additional information
required for a full technical description of components and apparatus
   /
9787
microstrip kit  note of a commercially available set of microstrip
components permitting rapid construction of circuits for operation
in the frequency range
   /
9788
a mathematical technique for the analysis of linear systems  the
technique of the transformation developed for investigating sampled
data systems is applied to the numerical solution of continuous linear
systems  a model of the linear system is devised in which sampling
is introduced at some convenient point  a polygonal approximation
to the sampled function is reconstructed by means of a holding operator
and the output of the system is computed as a train of pulses
   /
9789
properties of some wide bank phase splitting networks  errors in
the design equations presented by luck are indicated and alternative
methods of deriving the design parameters are mentioned  the return
difference matrix in linear networks
   /
9790
the solution of a certain differential equation  a method of obtaining
approximate solutions to a class of nonlinear network problems is
discussed  the method wal developed in relation to the problem of
a capacitor in series with a nonlinear resistor of the type and its
application is illustrated by reference to this problem the resistor
characteristic being assumed cubic and the applied voltage simple
harmonic  an exact steady state solution for this network is unobtainable
but an approximate solution is obtained by choosing the constants
in the formula for the voltage across the resistor such that the
applied voltage has no third harmonic component
   /
9791
matrix analysis of linear time varying circuits on cavity resonators
with nonhomogeneous media  perturbation theory is used to find the
frequencies of oscillation and factors of a cavity containing a medium
for which the permittivity and the permeability are arbitrary functions
of position  the theory is applied to cylindrical cavity containing
a disc of dielectric which dies not extend over the complete cross
section of the cavity
   /
9792
quantum effects in the interaction between electrons and high frequency
fields  the problem of determining at what frequency quantum mechanical
effects become apparent is approached by analysing the velocities
of electrons after passage through a cavity resonator  from the formulae
derived a calculation is made of the ratio of minimum possible mean
square deviation of velocity to velocity increment due to the field
assuming the volume of the cavity to be of the same order as and
the initial electron velocity to be of the order of
   /
9793
synthesis of ladder networks to give butterworth or chebyshev response
in the pass band  general formulae are derived for the design of
low pass ladder networks
   /
9794
synthesis of constant time delay ladder networks using bessel polynomials
a low pass minimum phase transfer function is constructed which
produces a ma imally flat time delay frequency characteristic and
a nearly gaussian impulse response  evaluation of delay and loss
characteristics is simplified since the transfer function can b expressed
in terms of tabulated function  synthesis of the corresponding
ladder network using low elements is described  characteristics of
a class of related non minimum phase transfer functions are also
discussed
   /
9795
gain bandwidth limitations on equalizers and matching networks  comprehensive
theory is presented and new results are given for the optimum
voltage transfer to an arbitrary load
   /
9796
synthesis of transfer functions by active networks  a criterion is
presented for determining whether a prescribed transfer function
can be synthesized by this means the arbitrary function can be treated
by breaking it down into quadratic elements  alternative methods
involving inversion of the transfer function of a ladder network
realization are also discussed
   /
9797
power gain in feedback amplifier  a search is made for a network
figure of merit shich remains invariant for different connection
conditions a quantity is found satisfying this requirement and identified
as the available power gain when coupling is chosen to make the
device unilateral  the quantity may be useful for classifying active
networks its value is unity for a gyrator  the method directs interest
to power gain and signal flow considerations rather than to voltage
gain and the network interpretation of an impedance matrix
   /
9798
determination of energy and phase characteristics of electrical filters
the leontovich theorem which states that in nondissipative media
the velocity is applied to the case of a filter considered as an
equivalent waveguide system  the velocity of propagation of energy
can be calculated when the dispersion is known
   /
9799
tunable audio filters  electromechanical filters of clamped resonant
reed type are described  the factor can be varied from over the frequency
range
   /
9800
vibration filters  the application of vibration galvanometers as
narrow band electrical filters is considered theoretically experimental
results for frequencies of are tabulated and presented graphically
the corresponding band widths varied between
   /
9801
inhomogeneous transmission lines as filters  mathematical treatment
of the filtering action of a transmission line with periodic structure
design is based on an approximate integral formula expressing reflection
coefficient as a function of characteristic impedance  its application
in a simple case shows that the centre frequency is determined by
the length of a section and the width of the stop band is dependent
only on the total length the number of sections  the formula gives
results in good agreement with e periment for a single section filter
with ratio improved matrix and determinant methods for solving networks
it is shown that a linear electrical network which may include valves
and transformers can br represented topologically by a network composed
entirely of elements of a single type comprises four nodes and two
directed branches  it is also shown that a linear electrical network
can be represented algebraically by a matrix termed an h matrix
if the elements of the network are shown in the network diagram in
the form of elements of the above type the h matrix can be written
down directly from the network diagram
   /
9802
effect of electrical fluctuations on valve oscillator  the oscillation
frequency is considered theoretically and a method of calculating
the effect is developed based on the einstein fokker equation
   /
9803
frequency control of short wave oscillators by means of an electrodeless
gas discharge  continuation of investigations reported previously
with lower oscillator power higher gas pressure and looser feed back
coupling a characteristic of quite different type is obtained giving
a rapid decrease of frequeecy with increase of anode voltage over
a narrow range
   /
9804
possibility oy obtaining very short continuous waves using a reylex
klystron supplying energy at high order harmonics oy the fundamental
oscillation  a yormula is given yor determining the wavelengths oy
the natural resonances oy the klystron cavity  the dependence oy
these wavelengths on the grid separation is shown graphically together
with curves giving the values corresponding to exact harmonics oy
the fundamental  the two families oy curves intersect at an infinite
number oy points at each oy which the cavity is capable oy oscillating
at both fundamental and harmonic frequency  using a klystron with
a beam voltage oy about and current and reylector voltage oy about
and current and reylector voltage wavelengths down to harmonic have
been generated with a power oy some tens oy microwatts
   /
9805
method for elimination of effect of stray capacitances in the production
and amplification of step voltages  discussion is presented of the
charge and discharge mechanism of a multivibrator circuit to obtain
a steep leading pulse flank a rapid discharge of the negative charge
accumulated at one of the anodes is necessary  this is achieved by
using the anode dynode path of an auxiliary secondary emission valve
pulses of amplitude up to with flanks of slope about sec were obtained
application of the principle in frequency dividers is also described
   /
9806
general properties of electromagnetic amplifiers  the relations between
gain bandwidth or time constant and power rating are discussed results
to be expected from use of feedback are e amined  the amplifiers
considered include thermionic valve magnetic and rotating machine
types  devices for improving the shape of the pass band normally
involve delay distributed amplifiers permit improvement of the gain
bandwidth parameter but not of the gain time constant ratio
   /
9807
starved amplifiers  advantages of the starved amplifier valve operated
with very low anode and screen voltages for high gain amplification
are indicated  relevant valve data must be determined by the designer
typical curves for miniature pentodes are presented and discussed
   /
9808
design of video couplings  a method is presented for designing low
rise time video amplifier coupling networks with three of four independent
elements by the proper location of complex zeros and poles of
the network function  the relations between rise time overshoot and
delay are determined  graphs are presented for determining the type
of response of a circuit with given type of response
   /
9809
zero stabilisation of directly coupled amplifiers  details are given
of circuits in which stability of a direct coupled amplifier is
achieved by use of a second amplifier in s feedback arrangement
the auxiliary amplifier is highly stable but has a low cut off frequency
hence low frequency signals are pre amplified giving enhanced signal
noise ratio at these frequencies  for high frequency signals the
auxiliary amplifier is by passed
   /
9810
an even harmonic magnetic amplifier  the circuit is an adaptation
of the inverter described by frost smith a typical figure for the
power gain and for the output  the zero drift is less than the shift
produced by an input power of  the input impedance ranges up to about
making it suitable for use iwth many types of transducer but the
poor response time restricts application to cases where the input
varies slowly  multistage amplifiers of this type are useful for
control and measurement purposes
   /
9811
fast response magnetic amplifiers  expressions are given for the
number of control turns and the gain of magnetic amplifiers of the
type described by ramey in which load and control circuits operate
on the magnetic state of the core on a time sharing basis
   /
9812
effect of circular field on form of longitudinal magnetization curve
the variation was investigated experimentally of the magnetization
of an iron tube placed in a coaxial magnetic field combined with
a circular field produced by a current flowing in a conductor placed
along the axis of the tube  the results which are presented graphically
are of interest in the construction of transformers for amplification
of weak currents
   /
9813
feedback simplifies transistor amplifiers  voltage amplification
in transistor stages os obtained using a degenerative feedback path
shunting the output and in series with the input  use of interstage
transformers or grounded collector stages is avoided
   /
9814
a transistor remote amplifier  a portable pre amplifier using point
contact transistors is described precautions necessary to avoid damage
to the transistors during construction of the equipment and during
use are indicated
   /
9815
ferroelectrics and the dielectric amplifier  galvanomagnetic low
frequency amplifier  a simple arrangement is described based on the
high magnetoresistance at low temperature  the device is much less
noisy than an ordinary valve or transistor
   /
9816
magnetic demodulation with sinusoidal variation of the induction
flux  with magnetic demodulation using sinusoidal current in the
demodulating reactor the flux is distorted  by arranging instead
for the flux to be sinusoidal the power can be increased  analysis
is given based on analogy with diode theory the flux being treated
as the equivalent of the voltage across the diode  essential differences
between magnetic and diode demodulators are discussed
   /
9817
statistical concepts in theoretical physics  a plea for the teaching
of classicas physics on an empirical basis on statistical lines to
make easier the transition to quantum physics
   /
9818
proposal for a new aether drift experiment  further elucidation of
the proposal made previously
   /
9819
the maximum of the planck energy spectrum  in the formula generally
used for locating the maximum in the energy spectrum of a black body
the spectral distribution is based on the amount of energy lying
between two closely spaced wavelengths  if the distribution is considered
on a frequency basis instead of a wavelength basis a very diferent
value is obtained for the position of the maximum for a body at roughly
the temperature of the sun the maximum then falls which is outside
the visible region  re examination of plancks formula leads to a
wien type law yielding a natural maximum fot the spectrum the location
of this maximum does not alter on changing from a wavelength to a
frequency basis
   /
9820
apparatus for microwave spectroscopy  the design of a spectrograph
using stark modulation and a crystal or bolometer detector is discussed
and a detailed description is given of a particular equipment
   /
9821
diffraction of waves by a wedge  greens functions of the wave equation
for a wedge are given in the form of an integral representation for
the two dimensional case and are evaluated by the residue theorem
the half plane is considered as the limiting case of a wedge with
angle  the analysis is extended to the three dimensional case
   /
9822
a uniqueness theorem and a new solution for sommerfields and other
diffraction problems
   /
9823
on the scalar diffraction by a circular aperture in an infinite plane
screen  application of variational principles reduces the problem
of finding the aperture distribution to the solution of an infinite
system of linear equations  an investigation is made of a particular
system of equations based on a convenient expansion of the aperture
distribution given by bouwkamp
   /
9824
general approximation method for solving diffraction problems  a
system of integro differential equations is established for the boundary
values  a known variational principle is used fo calculating certain
functionals involved
   /
9825
motion of charged particles in a homogeneous magnetic field with
superposed magnetic field of linear current and electric field of
cylindrical capacitor  the problem considered theoretically by kelman
and rodnikova is extended to include the effect of a magnetic field
parallel to the axia of the cylinder  calculated results for several
particular cases are presented graphically
   /
9826
conductivity in copper at wavelengths  measurements indicate that
reduction of conductivity below the value is caused not only by surface
roughness but also by the presence of surface layers having conductivity
lower than that of the bulk material and by stress in the bulk material
these effects can be overcome by etching and annealing or by covering
the surface layers by a process involving oxidation and reduction
   /
9827
limits of practical application of pisarenkos formula  pisarenkos
formula expresses thermoelectric power in terms of charge carrier
concentration and effective mass and of absolute temperature  a constant
factor is included to take account of scattering of the charge carriers
in the crystal lattice  calculations show that the errors are small
up to carrier concentrations of about atomic lattice and ionic lattice
crystals  the errors are discussed and compared with those of other
formulae  results are tabulated
   /
9828
the motion of electricity  preliminary experiments are described
on the mechanical transportation of electric charge by blowing streams
of ionized air or by causing such streams to flow in tubes under
a pressure difference  tubes are used as detectors with loudspeaker
indicators  currents up to have been produced
   /
9829
energy distribution function of electrons in pure helium
   /
9830
microwave determination fo the probability of collision of electrons
in helium
   /
9831
sone effects in inductively coupled electrodeless high frequency
gas discharges with super posed magnetic field  the effects noted
by lindberg were further investigated  the resonance effect appears
to be due to electrons moving initially in circular orbits coaxial
with the tube wall rapidly acquiring energy in the alternating field
an application fo the effect in a ion source is briefly described
for another application
   /
9832
extension of the spin wave theory of ferromagnetism to higher temperatures
   /
9833
possibility of considering potentials and fields as quantities having
density new type of quadrivector
   /
9834
on multipole expansions in the theory of electromagnetic radiation
a new method is developed for expanding the electromagnetic field
of radiating charges and currents in multipole components  outside
a sphere enclosing all sources the field is represented in terms
of debye potentials which are shown to be closely related to the
radial components of the electric and magnetic vectors  attention
is drawn to remarkably simple source representations of these radial
components  a discussion of vector potential versus debye potential
representation of multipole fields is included  only familiarity
with ordinary vector calculus is required
   /
9835
the radiation greens functions  analysis for the radiation field
of a group of charges is derived using functions similar to the greens
function of potential theory but applied to the time variables problems
of radiation theory  the method presents a model of interaction between
a quantum of movement of a unit point charge and the corresponding
excitation of a set of eigen fields it is illustrated by treating
the case of a point charge rotating in a cylindrical cavity
   /
9836
propagation of electromagnetic waves in a gyrotropic medium  correction
to paper abstracted direct comparison of hall effect and corbino
effect  by using a cylindrical sample immersed in a a radial magnetic
field a transverse current is produced when an alternating voltage
is applied between the ends of the cylinder this transverse current
gives rise to an induced voltage in a coaxial coil  both the corbino
and the hall effects can be measured with this arrangement thus providing
two independent means of determining the hall constant the discrepancy
between the two results is
   /
9837
the distribution of temperature along a thin rod electrically heated
in vacuo  the theoretical solution presented in part is considered
in the light of formulae discussed by stead relating the temperature
distribution in a finite rod to that in an infinitely long rod heated
by the same current  a useful expression is found for the temperature
at the centre of a finite long rod as a function of its length  detailed
experimental verification of the main theoretical results is reported
empirical formulae proposed by worthing are shown to follow from
the theory developed  the physics of experimental method  sections
are included on relevant mathematics mechanical construction and
materials vacuum technique electrical measurements and electronics
optics and photography natural limits of measurements and techniques
of nuclear physics
   /
9838
a comparison of the intensity distribution of radio frequency radiation
with a model of the galactic system  a comparison is made between
the radiation to be expected from objects distributed like the common
stars and the observed radiation  satisfactory agreement with bolton
and westfolds observations is obtained for the regions where the
radiation is considerable  near the galactic poles and in the hemisphere
opposite the centre the observed temperatures are about in excess
of the calculated values this excess is possibly due to a background
of distant extragalactic nebulae
   /
9839
methods and results of radio astronomy  a survey sith over references
   /
9840
radio observations of meteors  a summarized general account with
literature references of the most significant results obtained during
the seven years up to the end
   /
9841
present phase of solar cycle  observations of the intensity of the
coronal green line suggest that the minimum of solar activity is
flatter and lower than that of a first indication of the rise of
the new cycle was observed at the beginning of august  the next maximum
is expected to occur between summer and the end of and to be rather
low
   /
9842
the prediction of geomagnetic disturbances  shapleys method for predicting
geomagnetic indices is modified to take account of the variation
of the periodicity of the disturbance about the day average and the
maxima observed in the values of the indices in march and september
   /
9843
rocket exploration of the upper atmosphere  the text is given of
papers read at a conference at oxford in august  sections cover rocket
techniques atmospheric phenomena and composition of the high atmosphere
section deals with the ionosphere in particular and includes papers
on wave propagation measurements made using rockets reported earlier
a specially designed aerial used on dry rocky soil for short range
sky wave measurements at an analysis of a method of determining charge
densities from rocket tracking data and a suggested programme of
rocket borne magnetometer measurements  section sovers laboratory
studies including an experiment on cross modulation
   /
9844
study of layer splitting in the ionosphere  an equation is derived
expressing the conditions for one or more maxima to occur in the
height distributions of temperature and recombination coefficient
a numerical treatment is given for splitting with uniform temperature
distribution would imply a highly improbable value for the recombination
coefficient  on the other hand the presence of a warm layer within
the layer would lead to results consistent with the observations
   /
9845
absorption of short waves in the ionosphere  expressions are derived
analytically for the value of the decrement for values of the frequency
above and below critical assuming that collisions of electrons with
ions are much more numerous than with neutral molecules
   /
9846
high latitude ionospheric observations using extraterrestrial radio
waves  a preliminary account is given of observations made at college
alaska over a two month period in the spring of the effect of the
ionosphere on the reception of cosmic radiation at  strong absorption
of the diffuse background is most common at midday and least common
during late evening it is correlated with no echo conditions and
with variations of the geomagnetic field  observations on localized
radio sources indicate that scintillations are commoner in alaska
than in england  scintillations were observed whenever marked absorption
occurred during transit of the localized source through the aerial
beam this indicates that the lateral distribution of ionization during
periods of absorption is nonuniform  study of the scintillations
shoud provide information about irregularities in the ionosphere
   /
9847
the propagation of long electric waves round the earth in relation
to transmission interference and lightning atmospherics
   /
9848
an analysis of electric field after lightning discharges  the thundercloud
is represented by a vertical dipole and the in it is represented
by a constant current generator  the electric field comprises components
due to the charge on each pole which depends on the conductivity
of the air space charge related to the charge on the poles and free
decaying space charge released after a lightning discharge  dissimilarity
between the field recovery curves for near discharges and distant
discharges are explained by thid theory  stant discharges are explained
by this theory
   /
9849
theoretical calculations of field of low frequency electromagnetic
waves above earths surface
   /
9850
analysis of systems involving difference differential equations
a method alternative to that presented by chu for analysis of control
systems
   /
9851
compensation networks for carrier frequency servomechanisms  methods
are described for determining the transfer function and for the synthesis
of gain and phase correction networks particularly symmetrical
bridged t and parallel t networks
   /
9852
power supply for automatically controlled transmitters  descriptions
are given of the normal arrangements for taking power from the public
supply and of emergency arrangements using batteries or diesel generators
   /
9853
selenium rectifier instantaneous characteristics  current voltage
characteristics obtained by applying a rectified sinusoidal voltage
to a cell in the reverse direction have been recorded  a current
in the forward direction flows during a large part of the cycle
a convenient equivalent circuit to explain this result comprises
nonlinear capacitance and nonlinear resistance in parallel  both
resistance and capacitance decrease with increasing reverse voltage
and are relatively independent of the frequency of the supply voltage
over a wide range
   /
9854
signal operated switching  description of a fault warning system
operated by cessation of an audio signal and used as a programme
failure alarm  the circuit is based on a thyratron valve
   /
9855
dyseac the new n b s electronic computer
   /
9856
the effect of interpretive techniques on functional design of computers
analysis of the programmes for a number of computations performed
by the computer indicates the feasibility of designing an adaptable
and reliable computer having only a relatively small amount of rapid
access erasable store and a larger amount of rapid access non erasable
store in which would be held all interpretation routines function
block ets  the operator would require no knowledge of the actual
machine code but wou  d place his hyper programmes and data into
a slow speed backing store
   /
9857
programme design for the computer adaptation of routines for elaborate
arithmetical operations  discussion of the extension of the library
routine system to deal with floating point multiple precision and
complex arithmetic and certain combinations of these  the interpretive
method of programme organization is used
   /
9858
some transistor circuits  the characteristics of junction transistors
are discussed at frequencies of the equivalent circuit is already
as complicated as that of a thermionic valve at frequencies a hundred
times higher  particular circuits examined include one for a medium
wave broadcast receiver in which the selectivity is automatically
increased as the signal strength decreases  it is pointed out that
for a peak output power of the consumption is nonlinear distortion
in transistors is compared with the corresponding effect in thermionic
valves  the upper frequency limit set by cut off of current amplification
is considered in relation to trigger circuits  a circuit including
a and an transistor is shown which has properties resembling those
of a gas filled valve with adjustable ignition voltage short ignition
time very low discharge voltage drop and discharge noise
   /
9859
dielectric potentiometers  a voltage divider is described comprising
a movable electrode and a system of fixed electrodes all immersed
in a lossy liquid dielectric so that the paths between the electrodes
are both resistive and capacitive  the arrangement is suitable for
wide band operation since the product of the equivalent parallel
resistance and capacitance is a constant depending only on the nature
of the dielectric  various practical embodiments are described  desirable
characteristics for the dielectric are indicated
   /
9860
current noise in carbon film resistors  an experimental investigation
at audio frequencies is reported  the results are consistent with
an empirical formula according to which the current noise voltage
varies approximately directly with current  in a few specimens the
noise was found to depend on the direction of current
   /
9861
the resistivity of composition resistors at radio frequencies  continuation
of the previous discussion of the mechanism causing the drop
of resistance of composition resistors at  experimentally obtained
resistance frequency curves are presented for resistors comprising
a cylindrical column of an aqueous solution of sodium chloride a
cylindrical column of an aqueous solution of copper sulphate and
a cylindrical column of carbon resin composition  the resistance
of type is practically constant at frequencies up to while that of
types and drops considerably  the drop in the resistance of the composition
resistor is ascribed partly to the resistivity factor and partly
to the external capacitance factor  it is suggested that a frequency
independent resistor could be obtained by mixing carbon with a material
of high dielectric constant
   /
9862
component design trends high frequency coils use new core materials
points discussed include use of ferrite cores for coils operating
at frequencies up to about use of glass and other low loss materials
for formers and use of toroidal constructions
   /
9863
the capacity and field of a split cylindrical condenser using the
method of inversion  the complex potential of a split cylindrical
condenser is obtained by inversion of a known simpler case  expressions
are obrained for the value of the electrostatic field at points on
the axes of symmetry the surface density of charge on a conductor
and the capacity of the condenser  the expressions obtained by adams
using another method are deduced as one of three special cases for
which tables and graphs are provided  the results should prove of
value in the design of electrode systems for various purposes
   /
9864
miniature lacquer film capacitors  a manufacturing process is described
in which a thin film is cast on a supporting base and is metallized
and slit while still supported after which it is stripped and wound
into capacitor units  metallized films thick have been produced the
resulting capacitors are about a seventh the size of the smallest
metallized paper types  the support may be left in if the f  lm is
extremely fragile or if the capacitor is to operate at voltages below
about  a formula is derived for the effective series resistance
   /
9865
thickness shear and flexural vibrations of a circular disk  antisymmetrical
modes of vibration in a  quartz disk are investigated by considering
the simpler corresponding case of an isotropic disk  differences
between the frequency spectrum in this case and in that of the rectangular
plate are due to the presence of thickness twist modes in addition
to the thickness shear and flexural modes
   /
9866
theory of coupled endovibrators  a system of two cavity resonators
coupled by means of a narrow slot in their common wall is considered
theoretically  two classes of oscillations are considered those whose
frequencies are determined primarily by the length of the slot and
are nearly independent of the shape of the resonators those whose
frequencies are near the frequencies of the oscillations in the resonators
when not coupled
   /
9867
the wien bridge as a phase shifter  several circuits are presented
illustrating the use of the wien bridge to provide phase shift with
small amplitude change
   /
9868
networks attenuation and input impedance  useful formulae are presented
   /
9869
four terminal networks ith transfer function having zeros with small
real part  analysis of low pass filter networks based on insertion
loss principles to investigate the effect of critical zeros in the
transfer function plot on the reactance to be developed the accuracy
required in the calculation and the component values
   /
9870
some aspects of mixer crystal performance  correction to paper abstracted
in  please note change of number
   /
9871
criteria for the amplitude stability of a power oscillator  stability
criteria for a tuned anode oscillator are established in the form
of two inequalities derived from differential equations expressing
the voltage variations of the grid and anode and involving the ratio
of feed back power to anode power the ratio of the time constant
of the grid leak and capacitor combination to the time constant of
the tank circuit and functions of the angles of current flow for
grid and anode  experimental verification of the results using a
triode is reported
   /
9872
investigation of the dependence of natural frequency of oscillation
on spectral composition  a particular case of the theory of nonlinear
electric oscillations is considered  writing the solution of the
equation as the sum of is the amplitude of the harmonic given by
the fourier series the ratio  using this relation the dependence
of on the amplitudes of the spectrum can be calculated  the measured
and calculated frequency characteristics of relaxation oscillators
agreed well  the results are presented graphically  see also van
der for general introduction
   /
9873
crystal frequency multipliers for centimetre and millimetre waves
circuits are described for generating harmonics at frequencies using
crystals  the generator is coupled by a cross bar transition to the
crystal which can be shifted axially for purposes of impedance matching
higher frequencies can be achieved by use of crystals in a similar
arrangement
   /
9874
on the faithful reproduction of the flat top of a pulse in a high
fidelity pulse amplifier  an experimental verification is reported
of analysis presented previously  it was demonstrated that the anode
current may sag appreciably if the time constants of the cathode
and screen grid circuits are not properly chosen
   /
9875
resonance circuits comprising or elements and some applications
the frequency characteristics of the wien bridge and of an analogous
inductance bridge are investigated theoretically  pseudo resonance
phenomena occurring in the neighbourhood of bridge balance are discussed
true resonance is obtained when the bridge is associated with
a feedback circuit to act as an oscillator  the tuned amplifier and
the and oscillators are described
   /
9876
magnetic amplifiers  a general survey of types and applications
   /
9877
three phase high speed magnetic amplifiers  the principle of the
half wave magnetic amplifier is extended to three phase circuits
various arrangements are described  applications in the field of
high power control systems are discussed
   /
9878
the transistor as a amplifier for use in microwave measurements
a junction type transistor with emitter earthed may have a current
amplification as high as with low input impedance and high output
impedance  such an arrangement is  seful for amplifying the current
from a rectifier before application to a meter and enables the usual
galvanometer to be replaced by a robust microammeter
   /
9879
analyses of basic dielectric amplifier circuits  analysis is based
on a simplified charge voltage characteristic neglecting hysteresis
both parallel and series connected arrangements are studied  the
steady state response can be found with succesive approximations
transient response is also discussed
   /
9880
photoelectric emission in the extreme ultra violet  results of experimental
studies on photoelectric emission from various metals for quantum
energies up to cannot even qualitatively be ac  ounted for by the
common free electron surface effect representation  a new theoretical
model capable of explaining the observations at high photon energies
is presented
   /
9881
the influence of the cathode material on measured breakdown strengths
of solid and liquid dielectrics
   /
9882
kinetic equation for electrons in metals in strong fields
   /
9883
on deviations from ohms law in metals  it is shown on the basis of
the kinetic equations of electrons in metals in strong fields that
the deviations observed are due primarily to the delayed transmission
of energy at the collision of electrons with the lattice  at sufficiently
low temperatures the resistance should pass through a minimum
at a given current
   /
9884
ettec n the dependence of the decay times of space charges by the
static characteristic in intermittent discharges  the validity of
the hypothesis previously formulated has been investigated experimentally
measured decay times depend on the external circuit associated
with the discharge tube but the existence of an inherent decay time
dependent only on the static characteristic of the tube is indicated
an empirical method is developed for calculating decay times
   /
9885
space charge formation and the townsend mechanism of spark breakdown
in gases
   /
9886
measurement of the current during the formative time lag of sparks
in uniform fields in air  measurements were made of the current in
a parallel plane gap during the period between application of a voltage
and occurrence of breakdown  the current increased from a few microseconds
after application of the voltage to just before breakdown for
time lags between and  the results are in agreement with previously
developed theory except for an observed delay in the initial current
rise a possible explanation of this is discussed
   /
9887
determination of the electronic temperature in gas discharges  measurements
made in an electrodeless discharge over a pressure range and
an electron concentration range of ratio to indicate that the electronic
temperature remains practically constant its value being to within
in dry air
   /
9888
auger ejection of electrons from tungsten by noble gas ions  report
of an experimental investigation using atomically clean tungsten
and ions with various charges  the results indicate a value of about
for the energy of the fermi level above the ground state in the conduction
band in tungsten
   /
9889
theory of auger ejection of electrons from metals by ions
   /
9890
thermionic emission from copper at the melting point  a ex e imental
determination is reported of the constants and in the richardson
dushman equation where is the electron charge and is the effective
or isothermal work function  for solid at the melting point the values
of and were respectively for liquid respectively  the discontinuity
at the melting point is discussed
   /
9891
recent developments in magnetism  a survey with reference to publications
dealing with various aspects of the subject
   /
9892
magnetic flux produced by a dipole located inside a ferromagnetic
circular wire  an approximate formula is derived for the magnetic
flux through a coaxial plane circular area normal to the wire due
to magnetic dipole element inside the wire  the radii of the circular
area and the wire are assumed to be small compared with the axial
distance between the circular area and the dipole element  for experimental
confirmation of the formula
   /
9893
experimental investigation of change of magnetic flux in a wire when
one domain is remagnetized  the problem which is of importance in
magnetic recording was investigated theoretically by rytov the calculated
and experimental results are in good agreement
   /
9894
theory of strong electromagnetic waves in massive iron  maxwells
equations are solved for propagation in material having a rectangular
hysteresis curve  formulae are derived for depth of penetration wave
impedance and power input  the results are compared with those of
rosenberg
   /
9895
reflection from a wire grid parallel to a conducting plane  the parallel
wire grid backed by a conducting plane can be represented by an impedance
shunted across a transmission line as in the case of a single
wire  the value of this impedance depends on the angle of incidence
the spacing of the grid wires and the distance between grid and backing
plane  conditions are derived for the reflection coefficient to become
zero
   /
9896
diffraction of electromagnetic waves by an aperture in a plane screen
   /
9897
the diffraction of waves by an irregular refracting medium  a method
is described of calculating the diffraction effects produced by a
thick stratum of an irregular refracting medium  it consists of evaluating
the statistics of the phase irregularities in the wave front
after traversing the medium and treating these irregularities s having
been produced by a thin phase changing screen  for a particular statistical
model of the irregularities in the medium the result is shown
to be identical with that obtained using a different method
   /
9898
a further note on dual integral equations and an application to the
diffraction of electromagnetic waves  a solution obtained previously
is extended to cover cases in which the order of the bessel function
kernel is not zero  as an example the solution is applied to a problem
in the diffraction of waves by a plane slit discussion of the problem
is criticized  results obtained are in agreement with those of muller
   /
9899
hall effect in positive column  report of measurements of hall voltage
in the positive column of gas discharge tubes as a function of magnetic
field tube current distance between probes and gas pressure
   /
9900
theory of hall effect in ferromagnetics  assuming phonon interaction
the hall voltage is given by the equation where are constants are
the resistances of the specimen at absolute zero and at temperature
respectively is the intensity of magnetization at saturation and
is the current density  comparison with experimental results obtained
from measurements on a bar shaped specimen shows close agreement
   /
9901
hall effect in ferromagnetics  anomalous effects are explained in
terms of the spin orbit interaction of polarized conduction electrons
   /
9902
wave functions for impurity levels  a general method of solving difference
equations arising in impurity calculations is developed
   /
9903
propagation of electromagnetic waves radio location and radio astronomy
a brief survey of recent progress particularly since
   /
9904
detection of discrete radio sources at wavelength  details are tabulated
of sources observed at the naval research laboratory  the equipment
used is briefly described
   /
9905
nature of discrete sources of cosmic radiation  energy considerations
of the colliding gas coronas n show that a considerable proportion
of the kinetic energy of the colliding masses is transferred to a
relatively small number of relativistic particles and hence into
radiation  the cut off frequency is estimated to be about assuming
the particles to be electrons
   /
9906
observations of cosmic noise at  from observations made at a frequency
of with an aerial of beam width between half power points and directed
to a curve of equivalent aerial temperature as a function of sidereal
time is derived  the temperatures observed were of the order  the
curve is compared with curves derived for similar conditions by calculation
from the results of observations at  it is found that the equivalent
temperatures increase rapidly with decreasing frequency but the
ratio of maximum to minimum temperature decreases with frequency
it is shown that atmospheric noise levels observed by the standard
techniques sometimes contain a large contribution from cosmic noise
at this frequency
   /
9907
harmonics in the spectra of solar radio disturbances  investigations
over the frequency range indicate that spectral features of solar
noise bursts are commonly duplicated at of below the frequency of
the second harmonic  the results are consistent with the hypothesis
that the fundamental frequency corresponds to the natural plasma
frequency of the corona in the vicinity of the source  by applying
this result to a standard model of the corona information is deduced
regarding the position velocity and size of the sources  velocities
were found for two long duration outbursts and velocities as great
as for short lived type bursts  the generation of bursts may be associated
with longitudinal plasma oscillations excited by fast streams
of charged particles
   /
9908
the emission polar diagram of the radio frequency radiation from
sunspots  the variation in received sunspot radiation with solar
rotation was determined from a statistical analysis of observations
made over a number of years  half power widths of the radiation pattern
of an average sunspot derived from this analysis are for frequencies
respectively  results indicate that the lifetime of the radiation
sources is shorter for the lower frequencies the lifetime is comparable
with that of a visible spot
   /
9909
abnormal amplitude of seasonal effects in the ionosphere at the equator
and structure of the upper atmosphere  d layer absorption maximum
ionization and structure of the layer have been studied  seasonal
variations observed in equatorial regions are much greater than expected
from the geometrical variation of the suns position  known theories
assume simple variation of ionosphere parameters with cos  the deviations
observed are interpreted as indicating seasonal variations of
the structure of the upper atmosphere particularly as regards temperature
and its gradient molecular dissociation and movements of air masses
at an equatorial station at the solstices not only is the solar radiation
incident at an angle but the structure of the upper atmosphere
is that appropriate ot a latitude of about
   /
9910
motion of a single cloud in the ionosphere  the system comprising
cloud and ionosphere is treated as analogous to the system formed
by a horizontal wire aerial and the ground  the radiation pattern
consists of minor lobes arranged symmetrically with respect to a
central major lobe as this pattern moves with the cloud periodic
fading of transmitted pulses is observed at the receiver  periodic
fading preceded and followed by a steady signal can thus with appropriate
reservations be interpreted as due to a single cloud  an example
is discussed in which maxima were observed the wavelength being the
horizontal length of the cloud is estimated to be about
   /
9911
a monochromatically ionized layer in a non uniformly recombinant
atmosphere with applications to the d and e ionospheric regions
the recombinance fo the atmosphere is assumed to be given by a term
independent of height together with a term which varies exponentially
with height  a recombinance datum level is defined as that at which
the two terms are equal and heights are measured from this level
in scale height units  the level of the absorption peak being when
the suns zenith distance is or when the level of the electron peak
and the height distribution of the electron density are considered
for different values of and of particularly  when the electron peak
is always above the absorption peak and for it is always above the
recombinance datum level the electron peak for when the absorption
peak is below the recombinance datum level is about half way between
the two  the decrease of on the underside of the electron layer can
be much less steep than for a chapman layer if the absorption peak
is below the recombinance datum level  the results for the model
atmospheres considered are tentatively discussed with reference to
the and ionospheric regions but their potential value may be realized
only when better data for the region become available
   /
9912
focusing phenomena due to undulations of the ionosphere and determination
of collision number
   /
9913
electron density in the e layer during auroral displays deduced from
measurements of absolute brightness  the auroral luminosity  values
of electron density calculated from the photon emission for different
auroral forms range from electrons below
   /
9914
the association of pulsating and flaming auroras with complete ionospheric
absorption at macquarie island  simultaneous records show that
pulsating or flaming aurorae are frequently accompanied complete absorption
of waves incident vertically on the ionosphere but the nocturnal
variations of frequency of occurrence of the two phenomena are markedly
different in form
   /
9915
equipment for accurate measurement of height of ionosphere layers
use of timebase corresponding to a height range enables measurements
to be made accurate to within  the timebase triggering is controlled
by means of a phase shifter calibrated in height so that any desired
height range can be selected for close examination  because of the
pulse widening involved a differentiator stage with wideband amplifier
is interposed between receiver output and indicator  measurement
procedure is described
   /
9916
ionospheric height measurement by the method of delayed coincidence
an outline description with block diagram is given of equipment in
use at an indian station for regular observation of lunar tides in
the upper atmosphere  the apparatus can be readily adapted for automatic
recording of curves  the method is basically as described previously
but the technique has been improved giving an accuracy within  good
results are obtained even in the presence of heavy atmospherics
   /
9917
periodic fading of medium wave radio signals  slow fading was found
to correspond to interference between paths and between paths rapid
fading to interference between paths  the values of the vertical
drift velocity of the layer calculated on the basis of observations
of the three types of interference at an indian station for the period
between and hours were and respectively  ground wave fading indicates
a drift velocity decreases during the morning depth of fading also
decreases due to increasing d layer absorption
   /
9918
variations of intensity of the aurora at macquarie island
   /
9919
excitation processes in the aurora and airglow absolute intensities
relative ultraviolet intensities and electron densities in high latitude
aurorae  excitation of forbidden atomic lines in high latitude aurorae
the excitation processes are evaluated on the basis of optical and
observations  calculations show that electron densities occur in
bright high latitude aurorae  a summary is given of the various excitation
and de activation processes which may occur and an attempt is
made to decide which of these will be of major importance
   /
9920
atmospherics with long trains of pulses  the waveforms of atmospherics
having long continued trains of pulses and the systematic modifications
associated with time of recording storm distance and the presence
of a low frequency component are described  their interpretation
is discussed and the results of analysis assuming the simple ionospheric
reflection mechanism are presented  estimates of reflection height
and storm distance show the applicability of the theory to the temporal
parameters of the waveforms and the origins of two groups of atmospherics
having calculated ranges are considered  the variation of pulse
amplitude with reflection order is shown to lead to the channel during
the later stages of the return stroke although difficulties arise
in reconciling this concept with considerations of the magnitude
and orientation of the horizontal elements
   /
9921
multistage amplifier output impedance  based on the result that the
ratio of the net amplification to the parallel output impedance of
a simple amplifier is the same with and without voltage feedback
a simple expression is obtained relating the parallel output impedance
to the amplifier constants for the multistage amplifier with overall
feedback  the design of an amplifier with a gain of and a parallel
output impedance of is discussed briefly
   /
9922
silicon power rectifier handles  fused junction rectifier with a
junction area of is mounted in a copper radiator with a slotted periphery
high power handling capacity is obtained by use of forced air
cooling  characteristic curves are shown
   /
9923
direct voltage stabilizers in the range with particular reference
to degenerative systems  the maximum usable loop gain depends on
the frequency response of the system in practice loop gains of the
order of are possible the effects of mains voltage and load current
fluctuations are reduced by this factor  reference elements are reviewed
but electron energy analysers give comparable stability with smaller
size and current drain
   /
9924
a voltage stabilizer  a motor operated variac type of stabilizer
is described in which the voltage sensing unit contains only one
valve of cold cathode type and incorporates biasing to hold the output
voltage near the centre of the control range  the output is maintained
at  the correction rate is
   /
9925
relay time division multiplier  a simple valve less multiplier for
use in analogue computers is described
   /
9926
three dimensional analogue computer  the tridac is an electronic
hydraulic machine developed for the royal aircraft establishment
for solving problems in radar and guided missile operation  it occupies
of floor space uses and consumes under peak conditions  individual
mathematical operations are performed with an error of full scale
the basic analogue quantity is a voltage and the basic element is
a amplifier with a gain of the order of stabilized by association
with an amplifier
   /
9927
the calculation of the latent roots and vectors of matrices on the
pilot model of the
   /
9928
resistance network analogues with unequal meshes or subdivided meshes
a general method for deriving the finite difference approximations
to the partial differential equation which is solved by resistance
network analogues is applied to find the resistance values and the
currents which have to be fed in for and networks with unequal mesh
sizes  two ways of subdividing a network into finer meshes in the
ratio are then given and a network subdivision in the ratio is described
experimental tests have shown that these subdivisions introduce
negligible errors into the measured field distributions
   /
9929
a phonic wheel generator for position indication in digital computer
magnetic drum storage  the design is discussed of a variable reluctance
phonic wheel generator for frequencies above  the final form comprises
a rotating slotted disk and polarizing permanent magnet placed centrally
between two pickup heads  pickup output as high as has been attained
the system has been adopted in the type computer
   /
9930
calculation of the magnetic field in the ferromagnetic layer of a
magnetic drum  the variation of the field with permeability air gap
layer thickness and other factors is investigated assuming the ferromagnetic
layer to be of low permeability spinel material  while the
problem is nonlinear the linear approximation is satisfactory in
some cases numerical computations are presented for the drum used
in the swedish computer besk
   /
9931
extension of the generalized phase diagram method for studying the
stability of linear systems  extension of work reported previously
a rule for interpreting the phase diagram leading to a simpler method
of application is described  the damping necessary to ensure stability
is investigated by a graphical method an analytical method is developed
using a characteristic algebraic equation with real coefficients
   /
9932
automatic production for electronics  a review of the techniques
and design factors
   /
9933
the influence of electrical current on the contact between metals
experiments are reported in whic two blocks of gold were pressed
together in such a way as to localize contact in a single region
and current pulses were passed whose duration was chosen in relation
to the time constants of the contact so as to produce the effect
of a continuous current  the constriction resistance between the
blocks was measured before and after passage of a pulse from these
values the changes in the contact area were calculated  the results
indicate that below a critical value of current the contact area
is unchanged but above this current value the contact area is increased
by passage of current
   /
9934
a versatile output transformer for surge generators  description
of a tapped toroidal transformer designed to match the generator
to a wide range of values of load impedance without altering the
form of the surge
   /
9935
microwave discriminator stabilization of test bench  a discriminator
for stabilizing a reflex klystron operating at is discussed  a small
portion of the klystron output is applied to a cavity resonator and
the sum and difference of the resonator response and the incident
signal are used after detection and amplification to provide the control
voltage for the keystron reflector electrclosed loop automatic phase
control  the method described of designing a phase control system
for an oscillator is based on an application of techniques of servomechanism
analysis
   /
9936
wafer coil development for inductive components  the automatic production
of coils made of insulated metal foil instead of wire is described
the roll of foil is sliced into thin wafers which can be connected
in series to obtain the required inductance  physical and electrical
characteristics are similar to those of wirewound coils  closer spacing
of turns is possible than with printed circuit techniques
   /
9937
transductors with four limbed cores  transductors with four limbed
cores have characteristics which differ from those of conventional
transductors in their symmetry with respect to control current changes
such transductors are suitable for increasing the sensitivity of
non polarized relays and may be operated by either signals  the suppression
of response to negative signals is also possible with four limbed
transductors and this may be used to reduce swamping effects in
push pull magnetic amplifiers subjected to large signals inputs
   /
9938
accurate linear bidirectional diode gates  discussion of switching
circuits to be controlled by square wave voltages with gates of several
milliseconds  bridge arrangements of two four and six diodes are
described  operating factors considered include amplitude of control
voltage gain constancy of gain signal characteristic backward leakage
through the diodes and effects of unbalance  series parallel and
series parallel combinations are illustrated the use of a series
parallel arrangement of gates for processing radar data is described
   /
9939
the capacity and field of a split cylindrical condenser when the
conductors differ in length  the transformation using the usual
notation of jacobian elliptic functions gives the complex potential
at any point in the plane for the case of a plate of width raised
to a potential symmetrically placed between two semi infinite plates
at zero potential at distance apart  from this the field and the
capacitance of the system are obtained by the method of inversion
by comparing the results with those of a previous paper two algebraic
identities for the elliptic integrals and are obtained
   /
9940
the charging and discharging of nonlinear capacitors  capacitors
with semiconductor photoconductor or electroyltic dielectrics involving
space charge polarization are discussed and a formula is derived
for the characteristic  the charging and discharging processes in
such a capacitor are compared with those for a capacitor in which
is control voltage for the klystron reflector elec an increasing
exponential function of  the time variation of the differential capacitance
of the space charge type during charging and discharging is
investigated and is compared with the behaviour of a linear capacitor
exhibiting a distribution of relaxation times
   /
9941
the relation between time and frequency functions with practical
examples of the calculation of the transient response of linear transmission
systems
   /
9942
tje practical calculation of transient response for arbitrary attenuation
and phase distortion  phase characteristic is determined from
a given attenuation frequency curve by bodes method  the locus of
the complex transfer coefficient is approximated by fourier series
the calculated coefficients are used to evaluate the response function
for the case of unit pulse and unit step input  as an example the
transfer functions are determined for three different amplifier characteristics
in a receiver  the accuracy of the method in giving the
general shape of the transient response curve is verified using samulons
method  an appendix contains formulae for calculating the fourier
coefficients required and tables of the functions sin and sin applying
in cases and respectively
   /
9943
equivalence of two terminal networks  simple procedure is indicated
for synthesizing or recognizing or recognizing equivalent two terminal
networks containing three or more circuit elements
   /
9944
comment on networks terminated in resistance at both input and output
theory presented previously for lattice networks is supplemented
by indicating a method for obtaining or terminations
   /
9945
displacement of the zeros of the impedance due to incremental variations
in the network elements  a method is presented for evaluating errors
introduced in the analysis of networks by assuming that the elements
are purely reactive
   /
9946
response characteristics of a linear system with third order transfer
function  the rise time and delay time of a low pass system on application
of a step function input are calculated using elmores formulae
conditions for minimizing these times are determined for functions
with three poles and two zeros  the pulse transformer is treated
as a numerical example the calculations are supported by experimental
results as long as consideration is restricted to no overshoot conditions
   /
9947
radio frequency phase difference networks a new approach to polyphase
selectivity
   /
9948
forced oscillations in nonlinear systems with two degrees of freedom
analysis is given leading to the establishment of criteria for the
stability of oscillations in circuits coupled by mutual inductance
   /
9949
image parameters of filters with one or two cut off frequencies and
notes on the decomposition of the transfer coefficient  a table is
given of formulae for the image transfer coefficients and image impedances
of high pass band pass and band stop filters  methods of expressing
the transfer coefficients as the sum of the transfer coefficients
of the basic sections are explained though the band stop case cannot
be included  the filters are considered to be without loss and without
mutual inductance
   /
9950
narrow band filter composed of quadripoles  the design of filter circuits
for very low frequencies is discussed  oscillograms illustrate the
suppression of noise superposed on a signal  for theory of quadripoles
see also
   /
9951
transient operation of low pass and high pass lattice filters  an
expression is derived for the admittance of the lattice filter terminated
by its characteristic impedance functions  using a new inverse
transformation method the unit step response of some low pass filters
and the unit function response of some high pass filters are determined
a simple method is indicated for determining the response to an arbitrary
voltage
   /
9952
direct coupled waveguide filters  filters are considered of the type
comprising chains of cavity resonators with a common iris separating
adjacent cavities  design methods based respectively on impedance
considerations wave matrices and equivalence between the waveguide
filter and the lumped element filter are described for determining
the susceptance of the irises and their separation  theory is given
for the case of mismatching and formulae are derived for parallel
and cascade couplings  a four channel branching system for frequencies
ranging from to is described
   /
9953
ferrite attenuators in helixes  directional attenuation has been
observed using a cylinder fitting closely round a helix  attenuation
frequency curves are shown for two values of axial magnetic field
and attenuation magnetic field curves are shown for frequencies of
and  the directional effect is considerably higher than indicated
by elementary theory the reason for the discrepancy is discussed
   /
9954
ferrite phase shifters in rectangular wave guide  propagation theory
is developed for a nonreciprocal device with asymmetrical arrangement
as described by losses in the ferrite being neglected  the dependence
of the phase shift on the thickness of the ferrite slab on the degree
of asymmetry and on the intensity of the transverse magnetic field
is investigated  the field configuration in the guide is shown diagrammatically
for some special cases  a modification with two symmetrically
arranged ferrite slabs and antiparallel magnetic fields is also discussed
   /
9955
design of aperiodic oscillator circuit with inductive quartz crystal
the discussion is illustrated by a numerical example of an oscillator
using a valve and suitable in the or band
   /
9956
a new self excited square wave transistor power oscillator  the basic
circuit uses a push pull arrangement of power transistors in conjunction
with a transformer consisting of a centre tapped primary centre tapped
feedback and output winding and a single source  an explanation of
the operation and oscillograms of waveforms obtained are presented
good efficiency is obtained over a frequency range the range has
been extended up to with reduced efficiency  application to conversion
of power is discussed
   /
9957
class amplifier and oscillator design  charts are presented for simplifying
the design procedure using a method based on that of
   /
9958
mixing preamplifier  a circuit for mixing signals from several photocells
has diodes connected in the grid circuit of the separate input
valves so as to avoid signal attenuation which would otherwise result
from the parallel arrangement of these valves
   /
9959
travelling wave tube system having m ultiplied gain  advantage is
taken of the wide frequency band of travelling wave valves to obtain
increases gain by heterodyning the output to a different frequency
and then feeding it to the valve again  the system is useful in microwave
relay stations where it is in any case necessary to change the
carrier frequency to prevent feedback from the transmitting aerial
to the receiving aerial
   /
9960
gramophone and microphone pre amplifier  the equipment is designed
primarily for use with the amplifier described previously  separate
input stages and gain controls for gramophone and microphone channels
are followed by a mixing circuit  the full output of can be obtained
with harmonic distortion for sinusoidal inputs ranging from to about
with microphone and from with gramophone
   /
9961
the use of double triodes in high gain low frequency amplifiers
the type of amplifier stage employing a double triode is described
in which one triode section provides a high dynamic load resistance
for the plate circuit of the other an amplifier utilizing three such
stages and possessing a gain of the order of is described
   /
9962
infrared spectrophotometer amplifier  an amplifier for use with a
low impedance bolometer is described with complete circuit diagram
the amplifier input is of the order of at a frequency of corresponding
to a power input of the overall amplification is the methods used
to reduce nouse valve microphony are discussed
   /
9963
on the integral width of cascaded tuned amplifiers  a formula is
derived by which the overall integral bandwidth of an amplifier containing
a number of noninductively coupled circuits is expressed in the
effective quality factors of the separate resonance circuits  the
quantity can also be expressed in the integral widths of the separate
circuits for two or three stages very simple relations are found
   /
9964
a new circuit for balancing the characteristics of pairs of valves
both static and dynamic characteristics of a pair of valves are balanced
by adjusting the heater voltages by means of a potentiometer of a
few ohms resistance in series with the heater supply circuit
   /
9965
derivative controlled magnet amplifiers  a two stage circuit for
a low level fast response unit is described  the first stage acts
as derivative amplifier amplifying average increments of signal voltage
per half cycle of power supply voltage  the second stage acts as
integrator amplifying and summing the output voltage of the first
stage  if the negative feedback applied to the first stage is delayed
by a low pass filter the total time constant of a system incorporating
the amplifier can be effectively reduced
   /
9966
magnet amplifiers with inductive load  the instability region in
the control characteristic curve is discussed and a method of avoiding
operation in this region suggested
   /
9967
characteristics of magnetic amplifiers for industrial use  a specification
for standard units for regulator applications is drawn up  the
relative importance of the advantages and disadvantages of magnetic
amplifiers is considered in detail for pre amplifiers limited range
regulators motor field current regulators ward leonard drives  amplifiers
have a faster response than other types but at extra expense and
with added complication
   /
9968
pulse relaxation amplifier a low level magnetic amplifier  the principles
of operation are explained  linear amplification can be obtained
for an input signal of in a amplifier delivering an output of variation
of the temperature between ans of the supply voltage by resulted
in a maximum zero drift of less than over a two week period  the
gain varied by change of the supply frequency
   /
9969
diode amplifier  outline of the properties and applications of amplifiers
based on the reverse transient phenomenon associated with the
high degree of carrier storage in an junction diodes  thr frequency
of the power supply must not be less than that of the modulating
signal  such amplifiers can be used as pulse repeaters in flip flop
circuits or as wide band flat response amplifiers  faster operation
can be obtained with than with diodes
   /
9970
a new system of logarithmic units  a general discussion of the subject
treated by green
   /
9971
correlation of amplitude and phase fluctuations in wave propagation
in a statistically inhomo geneous medium  the cases considered are
the correlation of fluctuations of amplitude and phase at a single
receiving point and the correlation of amplitude pr phase fluctuations
at different receiving points  in the case of large sized inhomogeneities
the correlation between the amplitude or phase fluctuations extends
over a range of the same order as the correlation between the random
inhomogeneities of the medium itself
   /
9972
surface distributions of fixed charges and poynting vector in a system
of permanent volume currents  theoretical study of conditions in
a hollow cylindrical conductor
   /
9973
present state of theory of electric breakdown in solid dielectrics
a survey  the theory of the first stage of dielectric breakdown the
loss of electric strength can probably be given best in terms of
a kinetic equation for electrons in a solid  the effective cross
sections of ionization for low energy electrons the probability of
scattering of medium energy electrons by the vibrating lattice and
the effective cross section of recombination must be determined
the theory of the second stage the actual breakdown has not as yet
been given  it is suggested that the cause of the breakdown could
be connected with processes leading to the production of a shock
wave analogous to that occurring in the breakdown of gases at high
pressures  references include over to russian literature
   /
9974
mechanism of discharge between plane plates  the problem is considered
using the diffusion theory of the positive column with a term added
to take account of the character of the discharge  measurements show
that the electron temperature is higher than in a discharge under
similar conditions  a theory is proposed which explains the dependence
of the running potential on frequency
   /
9975
effect of secondary electrons on initiation of discharges  initiation
of discharges between parallel electrodes in inert gases was investigated
at pressures of using a frequency of and magnetic fields up to
two effects due to a transverse magnetic field were observed decrease
of breakdown potential and suppression of a glow discharge  the former
is due to the cyclotron effect the maximum reduction of occurred
at a field strength where is the frequency of the electric field
the latter is shown to be due to prevention of the secondary electron
resonance effect observed in a longitudinal magnetic field and noted
by in his work on the secondary electron multiplier
   /
9976
effect of moving striations on microwave conductivity of a coaxial
discharge  experiments were made with a discharge tube arranged so
that part of the discharge path fills a gap along the inner conductor
of a coaxial line  the results indicate a marked variation of the
microwave conductivity as striations move past the gap  the effect
may be strong enough to use for switching purposes
   /
9977
electron emission from metals under high energy hydrogen ion bombardment
   /
9978
method of measurement of the velocity of high energy electrons  formulae
relating the beam voltage to the oscillation frequency in carcinotrons
and loaded waveguide linear accelerators are used to determine the
electron velocity the only apparatus required is a wavemeter together
with a small line  velocities approaching that of light are treated
relativity effects are taken into account
   /
9979
the similarity law of secondary emission  measurements were made
of the secondary emission yield factor for a number of materials
under carefully controlled conditions particularly with respect to
clean target surface  results then agreed well with the experimentally
obtained universal curve a formula for which is also given
   /
9980
determination of the proportion of reflected electrons in the secondary
electron emission from copper and gold  an experimental determination
is reported  the retarding field method of was used with primary
potentials of the secondary electron yield was corrected for the
space charge effect  at a primary potential of and a retard  ng potential
of the percentages of reflected electrons in the total secondary
electron yield are and respectively the percentages are respectively
the results are presented graphically and are tabulated
   /
9981
galvomagnetic and thermomagnetic effects in a plasma
   /
9982
experimental determination of the energy distribution of thermoelectron
beams  an investigation using the lenard retarding field method is
reported  this method gave results accurate to within for electron
energies in the range  results indicate that a maxwell distribution
occurs only at low beam currents and densities  no direct dependence
was found on cathode temperature space charge at the cathode or control
potential a depence was observed on current density and to a lesser
degree on current intensity  deviations from maxwells distribution
could not be attributed to errors in calculation collisions with
the residual gas spectrometer effect of the emitter transverse resistances
of cathode or local anomalies of the work function positive results
were obtained by relating the electron energy distribution to longitudinal
space charge oscillations produced by the shot effect  shifts
of the energy distribution are due to changes in the work function
and the development of a potential barrier near the cathode
   /
9983
deduction of magnetic interaction in exchange model of ferromagnetic
metal
   /
9984
quantum theory of magnetostriction of ferromagnetic single crystals
theory is developed for crystals with hexagonal or cubic symmetry
at low temperatures  results indicate that magnetostriction is connected
with the magnetic interaction of electrons and also give the temperature
dependence of magnetostriction constants in the case investigated
   /
9985
the perfectly conducting ring subjected to high frequency currents
and magnetic fields  detailed analysis of the interaction of current
and field for a ring of circular cross section with current flowing
in a conductor along its axis carryii  g a c
   /
9986
a derivation of maxwells equations for a vacuum by means of an energy
quantum model  propagation phenomena such as interference and diffraction
can be explained by means of quantum theory if the energy quanta
are assumed to have finite volume  the magnitude of this volume is
estimated from consideration of the energy received by a dipole in
a field of strength
   /
9987
theory of the trentini absorption grid  exact theory is developed
for absorption of a normally incident wave by a loaded grid placed
near and parallel to a conducting surface  the case when a dielectric
intermediate layer is present is also considered
   /
9988
eitaromcoated spheres in the region of the first resonance  calculations
based on methods developed previously indicate that a dielectric
coated conducting sphere can be made to have a greater scattering
cross section than an uncoated conducting sphere of the same overall
diameter  this was confirmed experimentally using technique described
by  results of calculations and measurements are shown graphically
a physical interpretation is presented
   /
9989
electromagnetic wave propagation in bounded electron beams  equations
in appropriate form are solved subject to boundary conditions chosen
in accordance with a particular uniqueness theorem which is proved
modes of propagation in a waveguide completely filled with an electron
beam are determined
   /
9990
a simple high temperature microwave spectrograph  equipment for operation
in the frequency range is described based on the stark modulation
effect
   /
9991
determination of thickness and optical constants of thin films  theory
is given relating the thickness and optical constants of very thin
metallic films deposited on glass to the reflected and transmitted
light intensities  wolters theory is discussed
   /
9992
the physics of experimental method  the statistical interpretation
and mathematical manipulation of experimental results and the natural
limits of measurement are treated  electrical measurements electronic
devices and vacuum techniques are among subjects for discussion examples
of appropriate instrument technology are included
   /
9993
radio astronomy  a survey of techniques and results
   /
9994
the remnants of supernovae as radio sources in the galaxy  a critical
survey is presented of recent work on the sources of galactic radio
emission at metre wavelengths  observations indica  e that remnants
of supernovae may account for some of the sources and radio emission
may be due to collisions of gas at high velocities  results of flux
density calculations at are tabulated
   /
9995
novae and radio noise  calculations show that radiation generated
when two nova shells are emerging should be observable in the early
stages
   /
9996
an analysis of bursts of solar radio emission and their association
with solar and terrestrial phenomena  solar radio emission records
on seven frequencies in the range were studied over a period of months
the analysis which includes a number of histograms shows that many
of the properties of bursts change with frequency  a study of the
time delay between bursts on different frequencies revealed that
bursts often occur first a simultaneous up and down movement of ionized
material from the level of zero refractive index at that frequency
is postulated  it is found that bursts were more frequent than flares
fadeouts and crochets and that they almost always accompanied these
effects  the commencement of bursts appears to be simultaneous with
that of flares and crochets but precedes that of fadeouts by about
two minutes  in addition there is a rough correlation between the
intensity of bursts flares fadeouts and crochets
   /
9997
a symposium on meteor physics at jodrell bank  report of the symposium
held in at which papers were presented  these include several on
radio echo investigations ionization and excitation and one paper
on a possible mechanism of production of galactic radiation
   /
9998
theory of the meteor height distribution obtained from radio echo
observations shower meteors  sporadic meteors
   /
9999
distribution of coronal flares as a function of latitude during the
course of the solar cycle  distributions consistent with the commencement
of the new sunspot cycle have been observed
   /
10000
notes on the sunspot cycle  analysis of a long series of sunspot
cycles based on a period and illustrating the negligible gravitational
effect of the planets
   /
10001
practical methods of harmonic analysis for geophysical problems
use of fourier series for resolving the diurnal variations of geophysical
elemements is discussed  rapid methods of analysis based on ordinate
and ordinate schemes are described
   /
10002
magnetic observations at quetta during the total solar eclipse of
   /
10003
an intuitive description of the chapman ferraro theory of the inital
phase of a magnetic storm  the main mathematical results of the theory
are derived from a simple consideration of the dynamic characteristics
of a stream of ionized particles in a magnetic field
   /
10004
transients of magnetographs blankstantaneous values from recordings
   /
10005
relation between atmospheric ozone and storms  comparison of records
indicates that the ozone concentration in creases during storm times
the increase occurs suddenly on the average hours before the first
discharge
   /
10006
measurement of atmospheric humidity up to kilometers
   /
10007
scale heights and pressures in the upper atmosphere from radio echo
observations of meteors  methods are described for determining pressure
and scale height in the altitude range making use of theory developed
by kaiser
   /
10008
notes on the atmospheric refractive index in canada from aircraft
meteorologocal soundings  values of the refractive index calculated
from soundings made in connection with a shoran survey are compared
withstandard values
   /
10009
the latitudinal and seasonal variations of the absorption of solar
radiation by ozone  calculations indicate that the length of day
and the solar altitude factor are sufficient to give the major features
of the ozone solar absorption
   /
10010
short period variations in the ionosphere  a comprehensive review
is presented of methods and results of ionospheric research  short
period fluctuations are discussed in relation to theories of layer
formation
   /
10011
procedures used to improve the quality of ionospheric data  data
from field stations are regularly dealt with by the ionospheric data
quality control group of the upper atmosphere research section at
the  an outline is given of the procedures used with special reference
to the detection of errors
   /
10012
statistical analysis of echo  further investigation of the echo from
above the normal night timee e layer  an analysis of data for the
period indicates definite peaks in the percentage duration of these
echoes at the equinoxes and a positive day recurrence tendency  no
definite correlation has been found with sunspot numbers magnetic
storm data or e
   /
10013
electron densities in the ionosphere  a fresh interpretation of data
obtained from rocket measurements bassed on a breakdown in the independence
of propagation of the magneto ionic components of a signal transmitted
from the rocket gives an electron density curve in agreement
with records
   /
10014
continuous electron density measurements up to  electron distribution
at altitudes from was determined accurately from measurements made
during a rocket flight at  using records the electron density curve
was extrapolated to the maximum electron at  density increased rapidly
between  in the region densities were in general lower than the maximum
slight gradient variations in the lower ionosphere are probably the
major cause of large variations of virtual height  sporadic echoes
are apparently due to partial reflections from high gradient regions
   /
10015
spread over washington  analysis of records for the period  diurnal
curves for seasons and years throughout this period are similar with
spread occurring more frequently in winter than in summer and equinox
values usually midway between those for summer and winter solstices
sample data from six other stations show different characteristics
phenomena at watheroo merit further study
   /
10016
atomic nitrogen as a constituent for region  three temperature height
models are considered the nicolet mange model the possible upper
limit of temperature height gradient and an intermediate model  for
these particle concentration with height the rate coefficient of
reaction with height and the height and concentration of maximum
ionization are critically discussed and computed  the level of maximum
ionization produced by photo ionization of atomic nitrogen lies between
depending on the model considered  the concentration of atomic nitrogen
at the height at which diffusive separation takes place need not
be assumed to be greater than  hence atomic nitrogen could contribute
at least in part to the layery ionization  the possibility of ionization
of atomic oxygen at the third ionization potential is briefly discussed
   /
10017
a consideration of the electron disappearance in the layer of the
ionosphere  factors influencing the electron concentration and conventional
theories of recombination and attachment are reviewed  nocturnal
diffusion can account for only a small variation of concentration
but its effect on the altitude of maximum concentration is not necessarily
negligible  statistical analysis indicates that the influence
of pressure on the nocturnal variation of electron concentration
is unexpectedly small while that of temperature is large analysis
of the monthly mean values indicates that attachment rather than
recombination is the mechanism responsible for the electron disappearance
the influence of layer movements though not large is significant
further evidence in favour of the attachment theory is obtained from consideration
of distribution and from a comparison of the nocturnal
concentration variations at two sites  theoretical considerations
favour a process of electron removal in which collisions between
atomic ions of oxygen and excited molecules of nitrogen produce molecular
ions of nitrogen which in turn recombine with electrons
   /
10018
a theoretical investigation of the ionospheric electron density variation
during a solar eclipse  the investigation reported previously
by is extended to the general case of where is the apparent diameter
of the moon and that of the sun a uniform distribution of radiation
over the solar disk is assumed  convenient formulae are derived for
the minimum electron density and for the time of occurrence of the
minimum  for a partial eclipse of magnitude an approximate expression
is derived giving minimum electron density as a function of with
an error of the average ionospheric sounding equipment
   /
10019
thunderstorms and sporadic e ionization of the ionosphere  a study
was made of the increase of ionization during severe squall type
storms which are a feature of the weather in bengal in the pre monsoon
months march may  the transmitter frequency was gradually increased
as the squall approached and the frequency at which the echo disappeared
was noted  the observations were repeated every four minutes  results
are shown graphically for two typical cases  values of as high as
were observed compared with the average no storm value of
   /
10020
three phase static inverters power spacing vehicle equipment  a three
phase output at is obtained from a dc input of by means of si controlled
rectifiers
   /
10021
the physics of computer elements  the general principles of acoustic
electrostatic magnetic optical and superconducting storage systems
are discussed  magnetic or superconducting devices show the greatest
promise for future high speed applications
   /
10022
control pulse generation for a digital differential analyser  circuit
details are given of a transistorized unit which generates control
pulses by a pulse division method involving some unusual processes
   /
10023
thin films as elements for automatic computers  a review covering
the application of thin film storage devices including the cryotron
to data processing techniques
   /
10024
high speed logic circuits using diode logical networks and current
switching amplifiers  the use of diode networks as an alternative
to transistors in logical networks is considered  the circuits are
versatile and economical but require associated amplifiers and are
likely to have a limiting switching time of about
   /
10025
output coupling networks for use with logical circuits of the emitter
current switching type  zener diodes coupling networks required to
transfer the collector voltage swing in emitter current switching
circuits to earth level are considered  the disadvantage of low coupling
efficiency of passive output coupling networks is considered in comparison
with the versatility which they give to standard logical elements
   /
10026
reliability of electronic components  four papers based on contributions
to a discussion meeting on contributions to a discussion meeting
on circuit components and materials held by the nachrichtentechnisch
gesellschaft in stuggart  technological measures for improving the
reliability oy of components  lifetime investigations on capacitors
the effect of humidity on the electrical characteristics of capacitors
the unreliability of electronic equipment and its causes
   /
10027
recent advances in microminiaturizatio reliable components and cooling
techniques
   /
10028
silicon epitaxial microcircuit  a si microcircuit formed by vapour
phase deposition techniques is described  an eight layered epitaxial
structure was formed which was capable of oscillation in different
modes  shunting capacitive and resistive leakage effects are discussed
   /
10029
the design and performance of high precision audio frequency current
transformers  conventional multilayer current transformers are found
to have large high frequency errors  details are given of precision
single layer transformers which cov range
   /
10030
application of boolean notation to the maintenance of switching circuits
concise notation by boolean algebra of the operations in the maintenance
schedules of complex switching circuits is used to simplify
testing and fault location
   /
10031
high stability ferrite pot cores  describes a range of assemblies
suitable for laboratory use and for bulk production of stable inductors
   /
10032
analysis of ferrite core switching for practical applications  an
analytical expression describing the switching process is derived
which is suitable for practical circuit design  measurements confirm
the results of calculations
   /
10033
more matrix driver employing magnetic amplifiers  a high frequency
magnetic amplifier with high efficiency good signal noise ratio and
high output power has been developed
   /
10034
low impedance capacitor design with special application to filters
methods of reducing series inductance of conventional capacitors
are investigated  measurements of capacitor characteristics are discussed
and an improved method of connection for filter capacitors is
described
   /
10035
the reactive behaviour of nonlinear negative differential resistors
nonlinear negative resistance two poles may have a reactive component
when forming part of a given relaxation oscillator circuit
   /
10036
a general steady state analysis of power frequency relations in time
varying reactances  this analysis produces the manley rowe results
as special cases  an energy coefficient is derived which specifies
the behaviour of an individual frequency transformation  the modes
in which an individual transformation can operate are described and
related to a wide range of varying reactance devices
   /
10037
the calculus of deviations applied to transistor circuit an network
analysis  network analysis is simplified by the method described
rules are given for solving various transistor problems including
the distributed parameter network
   /
10038
some considerations on optimum filters  an explicit formula is derived
which gives the pulse response of a filter for signal detection in
o noise where the known signal is expressed in the form of a trigonometric
polynomial
   /
10039
the design of all pass low pass and band pass filters with a tchebycheff
type approximation of constant group delay
   /
10040
replacement of a cascade of unequal asymmetric quadripoles of equal
iterative impedance by one quadripole
   /
10041
the cascade connection of nonreversible quadripoles
   /
10042
the synthesis of active and passive filters by the root locus method
   /
10043
active filter element and its application to a fourier comb  a theoretical
analysis is given and constructional data are presented for a
variable q variable frequency band pass filter using transistor amplifiers
stable q operation is possible over q factor range of for frequencies
up to
   /
10044
the applicability of active filters to the measurements of the frequency
spectra of pulses  the use in frequency analysers of active filters
comprising amplifiers with double t type rc networks results in higher
q values at low frequencies than is possible with stagger tuned lc
circuits  the error assessment given by seeger and stablein of is
also applicable to this type of circuit
   /
10045
synthesis of transformerless active n port networks
   /
10046
a circuit with several stable state using tunnel diodes  the circuit
has four stable states the time required for a change of state being
of the order of it can serve as a fast pre storage device for a multichannel
analyser or as the basic unit of an associated address scaler
   /
10047
a tunnel diode univibrator and pulse height discriminator  an adaptation
of the tunnel diode oscillator circuit above and its operation in
conjunction with a biased backward diode see are described  applications
in pulse shaping and fast coincidence technique are noted
   /
10048
a fast amplitude discriminator  the circuit has a discrimination
range of with a threshold stability within  the output is a positive
pulse in amplitude with rise time and duration
   /
10049
new ways to trigger avalanche pulse circuits
   /
10050
reversible decimal counters  circuit design for both binary and bi
quinary scales of notation is discussed
   /
10051
tunnel diode binary counter circuit
   /
10052
investigation of the single ended push pull amplifier  theoretical
and practical design aspects of various versions of this type f af
amplifier are considered
   /
10053
a quick method for calculating transistor amplifier circuits  by
neglecting the parameter calculations on transistor amplifiers can
be greatly simplified  this is applied in calculations of feedback
temperature stability and noise
   /
10054
calculation of mixing processes in transistor stages at low frequencies
on the basis of the equivalent circuit diagram  extension of the
theory given in of august to transistor mixer circuits and to distortion
effects in them
   /
10055
nonlinear distortion of transistorized amplifiers  sources of distortion
are examined and methods are suggested for minimizing their effects
   /
10056
designing amplifiers with nonlinear feedback  design criteria for
the use of a nonlinear feedback loop with a transistor amplifier
are given  increase of dynamic range and an exponential response
can be obtained
   /
10057
design theory of optimum negative resistance amplifiers  an examination
is made of amplifiers obtained by imbedding a linear active one port
device in arbitrary three port devices  the optimum gain bandwidth
formula synthesis procedure and design curves are given for this
and other amplifier configurations
   /
10058
amplification through stimulated emission the maser  an account of
the physical principles underlying two and three level maser action
is given and expressions for noise factor are derived  recent maser
applications in radio astronomy systems are noted
   /
10059
general analysis of optical infrared and microwave maser oscillator
emission  the equations governing coherent emission are generalized
amplitude modulation of the signal is to be expected and this can
be used for communication purposes
   /
10060
cross doping agents for rutile masers  the electron paramagnetic
resonance spectra of rutile doped with ta nb and ce have been examined
at liquid helium temperatures  ta and nb appear to be suitable for
securing a short spin lattice relaxation time
   /
10061
a new microwave power amplifier  a method is suggested in which one
electrode of a lecher or coaxial line is made electron emissive
a signal propagated down the line produces an amplified current in
the anode
   /
10062
nonreciprocal parametric amplifier circuits  two circuit configurations
are given which do not use a circulator but which have similar properties
to the single port reflection amplifier with a three port circulator
   /
10063
staggered operation of doubly resonant parametric amplifiers  a broad
bandwidth is achieved by staggered operation of doubly resonant variable
capacitance parametric amplifiers in the band
   /
10064
on parametric excitation with current saturable inductances  a a
parametric amplifier circuit with an abrupt nonlinearity is described
a method of analysis of relaxation oscillations leads to a physical
understanding of the cycle of oscillations and quantitative relations
the stability problem is also solved
   /
10065
minimum noise figure of the variable capacitance amplifier  a discussion
of the minimum noise figure of variable capacitance diode amplifiers
on the assumption that the series resistance is the only parasitic
element  some experimental figures are given for dsb operation at
and universal curves are included which illustrate the effect of
changing network parameters and component temperatures
   /
10066
a solid state analogue to a travelling wave amplifier  an attempt
to improve the dispersive properties of multi diode parametric amplifiers
was made by placing stacks of varactor diodes inside an l band
helix  bandwidths of and a noise figure of were obtained  a low noise
microwave quadripole amplifier
   /
10067
travelling wave analysis of a class of parametric amplifiers based
upon the hill equation
   /
10068
electric fields and currents in dielectrics  a general solution is
given for the distribution of electric field and charge carrier concentration
in a dielectric between two metallic contacts when field emission
and thermionic currents flow from the cathode
   /
10069
potentials in a conductor of varying cross section  the importance
of the eigen hall effect of in masking the bernoulli voltage in experimental
measurements is pointed out
   /
10070
rectification effect in gaseous discharges in crossed magnetic and
electric fields  description of an experimental crossed field diode
consisting of two coaxial electrodes of stainless steel tube the
inner electrode being filled with a ferrite stack separated by pieces
of soft iron  results obtained with a hydrogen filled tube under
a pressure of show that the system is more efficient if the magnetic
field is localized near the inner electrode in this manner
   /
10071
the theory of secondary electron emission of metals
   /
10072
complex conductivity of some plasmas and semiconductors  the complex
conductivities of plasmas and semiconductors have been calculated
for several cases where the collision frequency can be expressed
as a power function of the energy  from the result some characteristic
parameters of the plasma originally investigated by spitzer are estimated
the problem of determining the relaxation from a non symmetrical
dispersion is discussed
   /
10073
couette flow of a fully ionized gas considered as a two component
fluid
   /
10074
experimental study of the diamagnetism of gaseous plasmas with electron
and nuclear spin resonance techniques
   /
10075
energy conversion mechanism in a bounded magnetized current carrying
plasma  for a finite plasma coupling exists between quasi transverse
em waves and quasi longitudinal space charge waves  this can lead
to an energy transfer between the kinetic energy of drifting plasma
and em energy  this mechanism may be useful for heating a thermonuclear
plasma using the runaway electrons  certain types of clf radio noise
can als be explained
   /
10076
emission of submillimetre electromagnetic radiation from hot plasma
in zeta  the first results are reported of experiments using spectroscopy
in the far infrared mm
   /
10077
oscillations of a plasma in a static magnetic field  the dielectric
tensor is calculated and used together wi  h the solutions to the
propagation problem at zero temperature to allow for thermal effects
   /
10078
the theory of plasmas in the presence of magnetic fields  on the
basis of boltzmanns equation the complete theory of a stationary
cylindrical plasma is obtained allowing for the presence of the intrinsic
magnetic field and of an additional longitudinal magnetic field
   /
10079
statistical mechanics of ferromagnetism spherical model as high density
limit  the conjecture of the validity of the spherical model of is
examined and justified
   /
10080
measurements on resonators formed from circular plane ad confocal
paraboloidal mirrors  a measured of was obtained and results were
in agreement with those of fox and relating to optical masers
   /
10081
cherenkov radiation in a dielectric tube waveguide  an experimental
arrangement for measuring the radiation is described and results
are given  high s interaction resistances can be obtained at the
expense of physical size and mode interference
   /
10082
shift of the shadow boundary and scattering cross section of an opaque
object
   /
10083
near zone back scattering from large spheres  theoretical treatment
of back scatter from a perfectly conducting sphere for short wavelengths
the back scatter cross section is modified considerably as the
receiver approaches to within a few radii and becomes the cross section
of a flat plate for a receiver very near the sphere
   /
10084
reflection and transmission of conductive films  a more general relation
for the reflection and transmission coefficients is given for the
case of oblique incidence and perturbations due to frequency dependence
and displacement currents are considered  a formula is also derived
for thick films
   /
10085
microwave zeeman effect of free hydroxyl radicals  the theory of
the zeeman effect in levels of light diatomic radicals is extended
to the general intermediate coupling case and used for detailed analysis
of observed paramagnetic resonance absorption spectra at of the products
of an electric discharge in low pressure and vp vapour
   /
10086
on the theory of cross relaxation in maser materials  the cross relaxation
rate is calculated by the method of moments taking into account
the effect of the crystal line electric field
   /
10087
phonon masers and the phonon bottleneck  a calculation shows that
the transfer of energy from the electron spin system can set up a
stimulated phonon emission leading to maser action
   /
10088
corkscrew a device for changing the magnetic moment of charged particles
in a magnetic field  a helical field source is described which produces
a monotonic increase or decrease in the transverse energy of a particle
moving initially in the uniform field along the helix axis
   /
10089
higher random phase approximations in the many body problem  the
usual random phase approximation combined with an equations of motion
technique for the many electron problem is extended yielding many
of the known results of series summation methods in a straight forward
manner  the method should apply to other types of many body problems
as well
   /
10090
a variational approach to correlation in an electron gas  a periodic
electron density is allowed and it is proved that there exist one
particle states energetically more favourable than the usual plane
wave orbitals
   /
10091
digital radiometer
   /
10092
radio emission from the cygnus loop  a high resolution study of the
cygnus loop has been made at and the results are compared with the
optical features  estimates of the thermal and nonthermal radio emissions
are made
   /
10093
secular variation of the flux density of the radio source cassiopeia
a  observations at support the evidence of hogbom ad shakeshaft of
a decrease of about per annum in the flux density of cassiopeia over
the last years
   /
10094
the microwave temperature of venus  solar corpuscular radiation
may maintain an ionosphere on venus and the variation in observed
brightness temperature may consequently be a function of zenith angle
   /
10095
the source of radiation from jupiter at decimetre wavelengths part
time dependence of cyclotron radiation
   /
10096
radio emission from the perseus cluster  two small components of
the perseus cluster separated by have been identified  they may be
physically related in a similar manner to that of the two emitting
regions in cygnus a
   /
10097
the effects of betatron accelerations upon the intensity and energy
spectrum of magnetically trapped a particles  the effects of change
of magnetic field on th energy spectrum are calculated
   /
10098
characteristics and fine structure of the large cosmic ray fluctuations
in november  report and discussion of observations of solar cosmic
ray increases on and november the former occurring at a gi time of
a sharp forbush decrease
   /
10099
balloon observations of auroral zone x rays  x rays are detectable
about of the time large increases occur during geomagnetic disturbances
   /
10100
seasonal variations of cosmic ray intensity in polar regions
   /
10101
analysis of a type of rough trail meteor echo  the characteristics
of b type echoes are examined in detail the rough trail may be due
to fragmentation of the dust ball type of meteoroid
   /
10102
the height variation of the ambipolar diffusion coefficient for meteor
trails  both the two station and the split beam measuring techniques
were used  it was concluded that the atmospheric scale height during
winter at a height of above jodrell bank is km
   /
10103
delayed propagation of solar cosmic rays on september  an analysis
of balloon rocket and ground level observations reveals tht the delay
between the flare and the arrival of solar protons increases with
decrease in proton energy
   /
10104
rocket observations of solar protons on september  the results of
nuclear emulsion and gm counter c observations are used to derive
the integral and differential spectra for protons of energy arriving
at the top of the atmosphere
   /
10105
magnetic disturbances and the earths magnetic field  storm time changes
in the earths magnetic field could induce currents in the earths
core which interact with the steady field  this produces a nett unidirectional
current at the end of the disturbance which penetrates gradually
down to the core and has a decay time of a million years  this current
could be responsible for maintaining the steady field
   /
10106
solar corpuscular showers and families of geomagnetic storms  investigation
of the effect of corpuscular showers in producing magnetic storms
and magnetic disturbances during which the corpuscular shower pass
near the earth without enveloping it
   /
10107
the ring current geomagnetic disturbance and the van allen radiation
belts  the negative phase of a magnetic storm is ascribed to the
formation of a ring current at a distance about four earths radii
from the earths centre  the magnetic field due to the current is
calculated and compared with observational results
   /
10108
radiation measurements during the flight of the third space rocket
preliminary analysis of results of instrument recordings made during
the flight of the rocket between the and october
   /
10109
secondary electron emission and the satellite ionization phenomenon
electron emission from a satellite and the electron density variation
near it due to bombardment by neutral particles are considered
   /
10110
sputtering as a possible mechanism for increase of ionization in
the vicinity of low altitude satellites  an increase in ionization
above ambient may occur at distances of up to mean path from the
satellite  ionization potentials of the injected atoms ar to those
of the ambient species  the probability of any collision leading
to ionization should exceed with the model proposed for the mechanism
to be of interest
   /
10111
the effect of atmospheric rotation on the orbital plane of a near
earth satellite  theoretical formulae are derived for the rotation
of the orbital plane and change in orbital inclination of a near
earth satellite due to the influence of the atmosphere
   /
10112
satellite determination of heavy primary cosmic ray spectrum  a preliminary
report of the heavy nuclei cosmic ray flux observed aboard explorer
is given
   /
10113
drop out phenomenon observed in the satellite transmissions  irradiation
of the quartz oscillator in during passage through the horns of the
outer van allen belt may explain drop outs sudden decreases of observed
signal strength
   /
10114
sideband correlation of lunar and echo satellite reflection signals
in the range  measurements are described and records of signal variation
are illustrated  with lunar reflections a correlation of was obtained
between sidebands with separation the correlation of signals reflected
from echo baloon with sideband separation was better than that of
lunar reflections with separation
   /
10115
production of carbon in the upper atmosphere  before decaying very
fast neutrons originating from disintegrations by high energy cosmic
ray particles may collide with nitrogen t atoms to produce and this
neutron capture should result in carbon and boron atoms and traces
of cyanogen gas being present in the upper atmosphere while by products
of the mechanism may contribute significantly to the formation of
the inner radiation belt
   /
10116
studies of the e layer of th ionosphere part electromagnetic perturbations
and other anomalies  departures from the predictions of simple
theory in observed e layer behaviour are attributed to perturbations
arising from the motor effect of the s system of currents flowing
there  the main effect is to raise near noon in low latitudes and
reduce it in high latitudes  the departure of from proportionality
to and other anomalies are also discussed
   /
10117
note on the role of small layers with irregular surfaces in the formation
of sporadic e layers  irregularities in the refractive index of
the troposphere have been represented by a model which has now been
adapted to the e layer  the reflection coefficients calculated using
the model are of the right order of magnitude
   /
10118
irregularities in the e layer of the ionosphere  correlation analysis
shows no systematic elongation at cambridge in contrast to the ew
elongation of auroral and elongation of equatorial type of e  there
is q wide range of sizes in the scale of the irregularities in the
diffraction pattern on the ground
   /
10119
consideration of the f layer in the ionosphere  a graphical statistical
description of the diurnal seasonal and annual variations of at kokobunji
and information on the relation between and
   /
10120
diurnal variation of f region drifts at waltair  the results of f
region drift measurements for the four seasons in the years are given
   /
10121
equatorial spread f at ibadan nigeria  spread f characteristics are
closely related to the height of the layer the irregularities may
be due to hydromagnetic disturbances which are increasingly attenuated
at lower heights
   /
10122
variation in height of anisotropy and random drift velocity of the
irregularities in the ionosphere correlation analysis shows that
the axial ratio of the anisotropy ellipse and the random change factor
are both greatest for waves reflected from heights of
   /
10123
possible identification of atmospheric waves associated with ionospheric
storms  the onset time of an ionospheric storm is defined as the
time of first increase at and the velocity is determined by measuring
the time delay at godley head north of campbell island  the mean
northward velocity for eight well defined storms was found to be
in the range and may correspond to the velocity of a neutral gaseous
wave as indicated by the johnston island nuclear explosion disturbance
   /
10124
a method of calculation of profiles from ionospheric curves
   /
10125
a new method for the analysis of ionospheric records  a method is
given for a calculating the real heights of reflection in the ionosphere
from the observed virtual heights  the real height is assumed to
be a polynomial in the plasma frequency
   /
10126
general expression for the group refractive index of the ionosphere
a general expression for the group refractive index of the ionosphere
is found in which wave frequency electron density and collision frequency
magnetic field and direction of propagation are variables
   /
10127
a solution of the integral equation a method involving power series
expansions is given for solving the integral equation  one advantage
of the method is the use of a set of master curves which applies
for all stations
   /
10128
a study of  he variations in a daily ionospheric index of solar activity
a table of daily values of sec at slough is given for  the short
term variations in from july december are examined by statistical
methods and it is shown that these variations are related to changes
in the sun
   /
10129
a long term variation in the relationship of sunspot numbers to e
region character figures  the statistical relation between sunspot
number and monthly mean values of at slough suggests that from onwards
there has been a decrease in the value of corresponding to a given
sunspot number
   /
10130
solar flare effects in the f region of the ionosphere  increases
in were observed during flares in and which were accompanied by increases
in sea level cosmic ray intensity  sm similar increases in are
reported in november at two stations and simultaneous falls in isoinic
heights of were also observed
   /
10131
sporadic e phenomena associated with the high altitude nuclear explosions
over johnston island  marked increases in e occurred near latitudes
and s and are attributed to the explosions
   /
10132
magnetic effects in the f region of the ionosphere  night time values
of f at stations in the south of africa are found to decrease with
increasing values of the equivalent planetary daily amplitude  the
magnetic control of night time ionization could account for the day
to day correlation of values  the relation of ionospheric and magnetically
quiet days is discussed
   /
10133
automatic ionogram scaler  an instrument has been designed which
projects an ionogram on to a screen  the parameters which are read
off are recorded simultaneously on punched tapes and in typewritten
form  the tape can be used to produce punched cards if required
   /
10134
active high frequency spectrometers for ionospheric sounding part
determination of true height from the virtual height of reflection
a new method for determining true hi height is described of august
ad its application to daytime and nighttime soundings discussed
   /
10135
a new type of ionospheric drift recorder  a method of eliminating
photographic and pen recording of fading signals and the laborious
calculations  a tape recorder is used to introduce a variable time
delay into one aerial feed  when this delay equals that of the received
signals a minimum is obtained  delays of have been measured
   /
10136
day to day and station to station correlation of ionospheric f region
critical frequencies  the correlation of simultaneous values at stations
separated by in a north south direction is found to have a semi diurnal
variation the phase of which varies with season  results at a single
station show an important autocorrelation for values at the same
time on consecutive days and this is ascribed to magnetic effects
   /
10137
year to year changes in the winter anomaly in ionospheric absorption
the mean anomalous component in a given winter is linearly related
to the mean magnetic c figure for the same winter
   /
10138
some characteristics of solar corpuscular radiations which excite
abnormal ionization in the polar upper atmosphere  statistical data
on the time delay from the occurrence of a major flare until the
onset of polar absorption have been studied  it is suggested that
particles ejected from the sun may be trapped in a corpuscular cloud
which may later intersect a magnetic line of force along which particles
can travel to reach the earth
   /
10139
the coupling between the protonosphere and the normal f region  in
the protonosphere above about the distribution of protons is determined
by diffusion rather than chemical processes this region is independent
of diurnal changes in the ionosphere
   /
10140
continuous recordings for the determination of the vertical gradient
of the refractive index in the free atmosphere  report on measurements
made by equipment mounted at six different  levels on a twoer to determine
the correlation between the refractive index gradient and field
strength fluctuations over a radio link path
   /
10141
the radio refractive index gradient over the british isles  airborne
microwave refractometer measurements made in the british isles confirm
that the quantity varies exponentially with height  the variations
in the parameters are less than those in the usa there is a high
correlation between the surface value of and the average decrease
in the refractive index in the first kilometre of altitude
   /
10142
a criterion for thunderstorm theories  results on the charging and
external currents of the same storm favour the classical theory rather
than the convection theories
   /
10143
aurora and airglow from colour film observations  summary of experience
using colour film records
   /
10144
investigation of auroral echoes part  ratios of measured echo signal
strength at and showed that the frequency dependence of the reflection
e coefficient is qualitatively e plained b by either an inverse law
partial reflection from large surfaces or an exp law scattering from
field aligned irregularities
   /
10145
narrow band atmospherics from two local thunderstorms were studied
reception frequencies of and were used with power bandwidths in the
range  duration peak amplitude mean field strength and mean power
flux were calculated  results conflict with some theories of the
origin of atmospherics
   /
10146
on the extremely low frequency spectrum of earth ionosphere cavity
response to electrical storms  a comparison of the observed and calculated
spectra in the range
   /
10147
simultaneous observations of clf noise at hobart and macquarie island
the noise sources seem to be small in size and to have different
locations at and kcs
   /
10148
dispersions of multiple stroke whistlers  analysis of igy records
at durban indicates a increase in the dispersion of successive components
of multiple stroke short whistlers which supports the current
jet hypothesis of whistler generation
   /
10149
theory of nonlinear control  a review of work in various fields of
nonlinear control
   /
10150
stabilized eht supply unit for photomultipliers  provided the load
is substantially constant the circuit will produce an output voltage
of with an error not exceeding during mains fluctuations of
   /
10151
spectral response of solar cell structures  measurements on si cells
with the pn junction to below the surface show that the short wave
response is relatively increased by making the junction close to
the surface and the long wave response by making it deeper  effects
of rough and smooth surfaces were also studied
   /
10152
on the  lectr  cal pa  am  ters of some types of s  lenium rectifier
   /
10153
variable precision regulated low voltage high current supply for
large electromagnets  circuit details are given of a power supply
with combined electronic and magnetic amplifier control delivering
currents of at with regulation and ripple values
   /
10154
design and application of a digital differential analyser  the principles
of operation and limitations of a digital incremental computer
are given and fields of research in which its accuracy and speed
would be useful are suggested
   /
10155
full binary adder with one tunnel diode  three resistors and one
tunnel diode in a wheatstone bridge network give both sum and carry
outputs
   /
10156
a program for finding the zeros of a polynomial by analogue computer
   /
10157
a magnetic associative memory  a computer storage system is described
in which data flow in and out on the basis of content rather than
location  a small experimental model of the system using ferrite
cores is also described
   /
10158
a probability distribution analyser utilizing electrostatic storage
the instrument has a linearity within and analyses input waveforms
of frequency
   /
10159
a universal nonlinear filter predictor and simulator which optimizes
itself by a learning process  after a discussion of some cybernetic
principles a machine is described which by a process of successive
runs on an input function ultimately produces a target function with
least error  the machine incorporates a tra k tape recorder and analogue
multipliers of a novel piezomagnetic type which perform multiplications
per second with errors not exceeding and
   /
10160
a cathode ray tube output for a digital computer  a variety of displays
can be programmed and are photographed by a camera controlled by
the computer
   /
10161
alphanumeric characters  the available characters are displayed by
the splot deflection method at a rate of sec  a full description
of the systems with block and circuit diagrams is given
   /
10162
logarithmic compression of binary numbers  this to bit converter
uses bits for the most significant figures and bits to indicate the
position of the binary point  accuracy is within
   /
10163
step by step design techniques for multilayer thin film networks
performances of various circuits incorporating thin film passive
networks and those with conventional components are compared
   /
10164
magnetics in doppler signal data extraction  doppler radar data extraction
problems such as detection integration and interrogation using
devices with magnetic cores are discussed
   /
10165
a magnetic device for high speed sensing of small currents  the structure
and operation of the ferror device are described  it comprises
a bar of low coercive force square loop ferrite with two holes transverse
to the long axis  the material around the holes acts as a pair
of toroidal cores whose switchable flux may be controlled by a solenoid
current
   /
10166
the vibrating capacitor theory and application
   /
10167
the energy properties of nonlinear reactance circuits  there will
be a conversion of power at one frequency to power at another frequency
if one frequency is a rational fraction of the other or if at least
one intermodulation frequency exists
   /
10168
a network theorem  the problem of determining the transfer impedance
between a generator emf at one end of a resistance terminated ladder
network and the load current at the other end is simplified by splitting
the circuit into two sections
   /
10169
on scattering matrices normalized to complex port numbers a terminal
network with generators having complex impedances is considered
   /
10170
a review of methods of linear network analysis in the steady state
parts  the establishment of an independent set of network variables
permits various methods of network solution  the four terminal network
and the use of reference parameters are also considered
   /
10171
wide band impedance transformers  an analysis of networks consisting
of cascades of lumped circuit sections of graded impedance level
   /
10172
a property of passive lossless quadripoles and its application in
the design of ladder filters  the validity of formulae giving the
values of elements of various filter structures is established by
expressing the insertion loss as a function of the iterative parameters
of a fictitious network
   /
10173
using jacobians for frequency selective networks  the advantages
of the use of jacobians for synthesis of networks to give a specific
frequency response is demonstrated with a simple network
   /
10174
computation of mechanical filters  filter design procedure and data
are summarized
   /
10175
active low pass rc filters  a method is described of synthesizing
the overall response of active cascaded low pass filters using simple
rc ladders and buffer amplification
   /
10176
tunnel diode down converters  different circuit analyses are compared
   /
10177
the dynamics of a subharmonic oscillator with linear dissipation
a mathematical analysis is made of the dynamic behaviour of subharmonic
oscillators parametrons assuming a nonlinear reactance but a linear
dissipation or resistance
   /
10178
present state of millimetre wave generation and amplification  a
review of techniques particularly those based on the use of conventional
microwave valves
   /
10179
pull in frequency of the phase controlled oscillator  the pull in
frequency derived by goldstein and confirmed experimentally by byrne
is lower than that recently derived by rey of january
   /
10180
additional negative resistance oscillation modes  several class c
modes are considered
   /
10181
voltage variable capacitors make a relaxation oscillator  the controllable
frequency range is
   /
10182
random pulse generator tests circuits encodes messages  the shift
register generator uses high speed logic circuits in producing complicated
pulse sequences up to bits in length
   /
10183
testing the linear distortion of transmission systems by means of
rectangular pulses and application of this method for explaining
the differential equalization used in magnetic tape equipment
   /
10184
generation of nanosecond carrier pulses at x band with tunnel diodes
   /
10185
tunnel diode ring counter
   /
10186
multiaperture core counters tive nondestructive storage read out
description of a counter circuit and its use in a missile guidance
control system
   /
10187
rf gate with carrier suppression  a gate is described with a carrier
suppression ratio db  the ungated cw signal is continuously available
circuitry leakage measurements and screening techniques are described
   /
10188
frequency multiplication by large factors by means of the oscillation
build up method  frequency multiplication by factors of several thousands
can be achieved with the oscillator described which is pulse controlled
at the fundamental frequency and produces a harmonic spectrum
of few components during the build up of oscillations
   /
10189
methods of pulse selection to produce accurate timing marks from
standard frequencies  counter circuits are given which are suitable
for the production of low frequency timing pulses independent of
phase fluctuations in the frequency dividers of crystal clocks
   /
10190
a matrix representation of linear amplifiers  expressions are developed
for the transfer matrices of combinations of bilateral and unilateral
networks and of some passive and active networks including r feedback
amplifiers
   /
10191
designing for low level inputs  difficulties arising in low level
input instrumentation and methods of checking and evaluating the
performance of such equipment are given
   /
10192
interstage design for stagger loaded amplifiers  a family of low
pass butterworth amplifiers each stage having a different load impedance
is described  the resulting stagger loaded amplifier has high gain
and large band width an example shows half power points at and and
a mid band gain of
   /
10193
the theory of negative feedback voltage amplifiers  a modification
of the standard method of analysis taking account of the fact that
the attenuated feedback voltage cannot always be subtracted directly
from the input voltage in practice
   /
10194
dc amplifier with particularly high zero level stability  a push
pull circuit for drift compensation in dc amplifiers is described
and details are given of its practical application and performance
   /
10195
contribution on the dynamic plate load amplifier  a method is described
for improving frequency and phase response of the type of amplifier
considered in of brown
   /
10196
single ended self balancing magnetic amplifiers for changing the
effective impedance of ink recorders
   /
10197
common emitter amplifier  the medium frequency performance of common
emitter amplifiers is examined in terms of the simple equivalent
circuit for a transistor  formulae enabling the best type of transistor
to be selected are derived
   /
10198
transistor cascode circuit improves automatic gain control in amplifiers
an improved method with circuit details for applying agc to transistor if
tuned amplifiers is described  the effects of changes in the
transistor parameters with change of operating point on the q factor
and the centre frequency of the tuned circuits are minimized
   /
10199
a theoretical comparison of average and spot noise figure in transistor
amplifiers
   /
10200
investigation of the performance of coupled cavity maser type amplifiers
part  a general formula is developed to determine the equivalent
noise temperature and gain stability of several elementary structures
by comparing these results interesting features of multicavity masers
are demonstrated
   /
10201
travelling wave maser with instantaneous bandwidths more than twice
the intrinsic line width of ruby were obtained by stagger tuning
the applied external magnetic field
   /
10202
parametric circuits with nonlinear reactances and resistances  equivalent
circuits of nonlinear reactances and resistances ar derived for
calculations on parametric amplifiers  expressions giving the circuit
voltages are tabulated for parametric amplifiers up converters and
down converters of the dynatron type and the non linear capacitance
type
   /
10203
sensitivity of the degenerate parametric amplifier  although the
noise temperature of a degenerate parametric amplifier is half that
for a nondegenerate amplifier the minimum detectable signal is only
better because the post detector noise fluctuation increases by a
factor
   /
10204
noise measure of distributed negative conductance amplifiers  the
modification required to the noise measure for circuits in which
the characteristic impedance has a reactive part is given
   /
10205
the noise temperature of cascade connected amplifiers  a formula
is derived for the noise temperature of a cascade connected amplifier
with negative conductances as active elements  this permits a simple
graphical representation of noise characteristics examples are given
of parametric amplifier stages and the influence of isolators and
circulators on noise temperature and bandwidth is discussed
   /
10206
parametric amplification with a low frequency pump  the degenerate
form of a three frequency parametric amplifier is considered
   /
10207
an l band travelling wave parametric amplifier  a gain of over a
band around has been achieved
   /
10208
reactance diodes and their application in wide band waveguide amplifiers
   /
10209
noise in beam type parametric amplifiers
   /
10210
parametric coupling between the transverse waves on and m type beams
   /
10211
transduction of noise theory of a generalized travelling wave coupler
   /
10212
selective high frequency amplification with tunnel diodes  the design
of a vhf fm tuner using tuner using tunnel diodes is detailed
   /
10213
minimum noise figure of the negative resistance amplifier using esaki
diodes  the minimum noise figure is determined for a nonreciprocal
single stage amplifier and the result is extended to cover multistage
amplifiers  a noise figure of about can be achieved for high gain
single stage or multistage amplifiers
   /
10214
semiconductor diode circuit provides gain  the forward reverse characteristics
of a diode can be used to provide amplification see of  the
characteristics of a circuit operating with power supply frequency
considerably higher than the signal frequency are noted
   /
10215
noise measure of lossy tunnel diode amplifier stages  the influence
of circuit losses and the diode series resistance on the noise figure
of tunnel diode amplifiers is considered  the calculation is repeated
for a stage parallel circuit
   /
10216
a saturable core modulation integrator  a circuit is discussed which
illustrates the use of saturable core reactors for operating directly
on a modulation carrier  use is made of the ability of a saturable
reactor to convert a voltage integral to a magnetic flux and store
it until required
   /
10217
constant resistance modulators  zobels constant resistance networks
are interpreted in terms of constancy with time when the elements
of the network are time variable and simultaneously in the same network
the original conception of constancy with frequency when the elements
are frequency variable may be realized  the application to rectifier
modulators is examined
   /
10218
requirements regarding electrical squaring circuits and practical
possibilities for the realization of square law characteristics
the design of square law detector circuits for use in the measurement
of rms values is discussed and the characteristics of various types
of circuit using diodes or amplifier v valves are examined
   /
10219
squaring circuits with staggered diodes  with the circuit described
a square law characteristic can be synthesized over a range of about
ge diodes give better results than those obtained with thermionic
valves
   /
10220
crystal biasing improves millimetre wave detector  at improvement
in noise figure could be obtained by suitable biasing
   /
10221
variational method for transport parameters in electron conductors
the method described results in a simplification and clarification
of calculation procedure
   /
10222
derivation of the boltzmann transport equation for inelastic collisions
a quantum mechanical treatment similar to that developed by kohn
and luttinger for elastic collisions of  for fermi dirac particles
the scattering in the collision terof the transport equation is restricted
to unoccupied states only
   /
10223
negative resistance and hot electrons  characteristics of ho  electrons
are analysed for negative resistance regions  electrons in a homogeneous
semiconductor are assumed to interact only with acoustic phons and
charged centres of heavy mass which could be ionized impurities or
heavy holes
   /
10224
electron bunching in the multipacting mechanism of high frequency
discharge  electron bunching is analysed by an extension of simple
multipacting theory
   /
10225
electronic and ionic current at the cathode of a hollow cathode discharge
the fractions of electronic and ionic current densities in the
discharge are estimated  the possibilities of other electron emission
mechanisms are discussed
   /
10226
instability of a plasma with an anisotropic distribution of ion and
electron velocities  investigation of the propagation of magnetohydrodynamic
waves in an infinite a rarefied plasma  a kinetic treatment
leads to an increase of the instability region compared to that obtained
in the quasihydrodynamic approximation
   /
10227
fluctuations in a multicomponent plasma  a theory of fluctuations
in a plasma consisting of electrons and one kind of ion below is
generalized to apply to several species of ions
   /
10228
electrostatic sound wave modes in a plasma  the ratios between the
frequencies of the peaks observed in the anode voltage fluctuations
in discharge tubes agree with those calculated using a simple theory
of radial modes
   /
10229
coupling mechanisms between longitudinal and transverse waves in
a plasma  the possible coupling mechanisms are deduced on the basis
of fundamental plasma equations  the existence of a nonlinear internal
coupling effect is proved which can cause em radiation
   /
10230
enhanced diffusion and oscillations in weakly ionized plasmas
   /
10231
average forces in electromagnetic systems  for ar a linear and loss
free system it is shown that the time average force can be expressed
in directly measurable circuit theory parameters
   /
10232
a supplement to a study of electromagnetic point point sources  a
supplement to a previously published paper establishing that there
are only two fundamental fields which can effectively be replaced
by a point source corresponding to a distribution concentric about
its origin
   /
10233
cherenkov radiation for a dipole moment in a medium with spatial
dispersion  treatment of electric and magnetic dipoles in an isotropic
nongyrotropic medium  radiation from a ring current in such a medium
is also considered
   /
10234
radiation by charged particles passing through an electron plasma
in an external magnetic field  coupling between the longitudinal
plasma wave and the transverse em wave modifies the nature of the
radiation  at particle velocities greater than that required for
the excitation of plasma waves a non cherenkov type of radiation
will occur
   /
10235
incoherent microwave radiation from a plasma in a magnetic field
the microwave emission from a plasma in a magnetic field is calculated
theoretically using kirchhoffs radiation law for cases when characteristic
waves do not couple within the plasma  experimental observations
of radiation temperatures and cyclotron radiation line breadth and
shape are cited to illustrate applications of  he theory to experiment
   /
10236
classical electrodynamic equations of motion with radiative reaction
the classical theory is reviewed previous objections to it are shown
to be largely invalid
   /
10237
radiation from fast particles moving through magnetic materials
under certain conditions of frequency and angle of observation ringing
of the spin system occurs  differences from the normal cherenkov
effect are discussed also the possibility of using the effect as
a neutral magnetic moment detector or as a probe of magnetic materials
   /
10238
wave propagation in an inhomogeneous waveguide  analysis of the propagation
of acoustic waves in a waveguide whose properties vary along
its length  the theory developed is applied to the propagation of
acoustic and em waves in natural waveguides which may extend to distances
of km and more
   /
10239
study f of the electromagnetic field produced bya magnetic doublet
in the presence of two medi separated by a plane surface  a rigorous
treatment for the general case of a doublet with its axis at any
angle to the surface between the media  the effects of special media
are also considered
   /
10240
the reflection of electromagnetic waves at a plane metal surface
covered with an absorbing layer  the reflection coefficient is calculated
as a function of for an em wave incident perpendicularly on a
thin absorption layer  numerical and graphical methods are given
for the evaluation of layer parameters which make the reflection
coefficient as small as possible over a wide range of
   /
10241
a note on the back scattering of a circular disk  asymptotic series
are obtained for the back scattering cross sections of an acoustically
hard disk an acoustically soft disk and a perfectly conducting disk
   /
10242
the diffraction of electromagnetic waves at rectangular apertures
in plane metal screens  an approximation method of calculating the
diffraction field is applied to the case of rectangular apertures
results are compared with those obtained experimentally
   /
10243
diffraction by an elliptic cone  two greens functions are derived
for the reduced wave equation in the exterior or interior of an elliptic
cone
   /
10244
a note on the back scattering by an infinite strip  the first few
terms in the asymptotic series of the back scattering cross section
of an infinite strip lying in a plane perpendicular to the direction
of propagation of an em wave are calculated for all angles of incidence
   /
10245
scattering of a surface wave by a discontinuity in the surface reactance
on a right angled wedge  an examination of the em field produced
when a surface wave travels along the front face of a right angled
wedge and is c scattered by the tip
   /
10246
an experimental study of bistatic scattering from some small absorber
coated metal shapes  the absorber coating reduces energy scattering
in the back hemisphere but increases the energy scattered in the
forward hemisphere
   /
10247
mechanisms of double resonance in solids
   /
10248
ferromagnetic relaxation part theory of the relaxation of the uniform
precession and the degenerate spectrum in insulators at low temperatures
scattering by surface polishing imperfections equalization of
degenerate mode populations and raman scattering are considered theoretically
and compared with experiment
   /
10249
theory of magnetostatic modes in long axially magnetized cylinders
the characteristic equation determining the eigen frequencies of
the magnetostatic modes is derived from the equations of motion and
the boundary conditions
   /
10250
instability of spin waves and magnetostatic modes in a microwave
magnetic field applied parallel to the dc field two methods of calculating
the instability threshold are described a plane wave analysis
strictly applicable only in an infinite medium and a more rigorous
theory in which the boundary conditions at the surface of the sample
are taken into account
   /
10251
the role of phonons in paramagnetic relaxation  theory is given for
the coupled spin lattice bath system with nonequilibrium phons  experiments
fail to indicate the presence of such phonons
   /
10252
observation of forbidden resonances in optically driven spin systems
   /
10253
thermal tuning of ruby optical maser
   /
10254
radio techniques and space research  a brief review of the papers
on radio topics presented at the british ir convention
   /
10255
the stability of force free magnetic fields  the condition is derived
for a force free magnetic field to exercise a stabilizing influence
on an equilibrium configuration several cases are given for which
the condition is satisfied
   /
10256
the technique of radio astronomy  review of applications of radio
techniques in modern astronomy including radio telescopes interferometers
and echo equipment
   /
10257
results of radio astronomy  review of the field of radio astronomy
measurements particularly with regard to solar observations
   /
10258
radio astronomy  various measurement techniques in the  hree main
fields of research are described and their limitations discussed
   /
10259
the radio telescope interferometer at the royal radar establishment
two mobile and steerable radio telescopes with parabolic reflectors
in diameter are used either separately or in conjunction as an interferometer
the system is designed to operate in w wide frequency range
down to cm
   /
10260
a new source of centimetre radio waves  during observations carried
out at pulkov observatory on march on a new rf source of energy was
detected in the galactic plane the co ordinates being and
   /
10261
lunar occultation of a radio source  by observation of the times
of disappearance and reappearance of a radio star behind the moon
the position of the source can be obtained with great accuracy  taking
into account all sources of error the estimated position is probably
correct to within of arc
   /
10262
solar radio astronomy in taly  the development of radio astronomy
outside and inside italy is traced and details are given of installations
at the astrophysical observatory at arcetri  some results of observations
made there are illustrated and discussed
   /
10263
observations of solar radio noise during august  solar rf noise during
the noise storm in august showed that the intense amplitude scintillation
does not appear to extend down to frequencies as low as and that
the storm both began and ended before the m storm did so
   /
10264
very low frequency modulation of discrete frequency solar noise bursts
measurements of type and type bursts at and show envelope fluctuations
which were examined over the range  the observed narrow band structure
is illustrated
   /
10265
a relation between solar radio emission and low energy solar cosmic
rays
   /
10266
characteristics of the ngc radio emission  observations carried out
with the puk pulkov radio telescope of virgo a showed that the angular
extensions of  he rf source on are smaller than those determined
by mills on cm  brightness distribution depended essentially on wavelength
   /
10267
radiation measurements of kilometres altitude at equatorial latitudes
the relative fluxes energy spectra and angular distributions of electrons
and protons determined during three flights are reported  the
electron spectrum appears to be softer than that expected from a
neutron beta decay origin
   /
10268
effect of hydromagnetic waves on the lifetime of van allen radiation
protons  hydromagnetic waves with frequency less than and amplitude
at two or three earth radii are capable of removing all high energy
outer belt protons maximum energy in about day  if an albedo neutron
source is assumed for the inner belt protons the calculated proton
flux as a function of radial distance from the earth agrees well
with pioneer results
   /
10269
cosmic ray phenomena during the november solar disturbances  cosmic
ray data for high and middle latitude stations are examined to investigate
the interaction of a solar flare increase and forbush decrease
   /
10270
the spectrum and propagation of relativistic solar flare particles
during july  an examination of cosmic ray data reveals two increases
of solar protons for which the time vr variations are quite different
this difference is attributed to a change in the interplanetary field
   /
10271
a theory of radar reflection from the moon and planets  relations
between the surface statistics of an irregular radar target and the
angular power spectrum and autocorrelation function of the reflected
signal are derived  the spatial correlation function is also computed
the theory is used to investigate the small scale structure of the
moons surface
   /
10272
meteorites and meteors  a general outline of the field of meteor
studies with a few details of meteor tracking equipment at the microwave
centre in florence and results obtained there
   /
10273
the distribution of meteor masses for sporadic meteors and three
showers  distributions of maximum line densities in meteor trails
are derived from radio echo data for sporadic and shower meteors
   /
10274
attachment processes in meteor trails  the effects of electron attachment
to neutral particles on the characteristics of long duration meteor
echoes are considered  two body and three body attachment processes
produce differing effects and these are compared with observations
   /
10275
the characteristics of persistent sporadic meteor echoes  for sporadic
meteors whose trails have an electron line density greater than electrons
the observed distribution of meteor echo duration cannot be explained
by power law distributions  there is no significant seasonal or diurnal
variation in the mass distribution of the meteors examined
   /
10276
a possible explanation of th long duration radar echoes of ionized
trails in the upper atmosphere  in ionospheric regions where the
plasma frequency is near the frequency of the incident wave the local
wavelength of the latter is very long and the destructive interference
of the fields scattered from the dispersed trail is less effective
   /
10277
volume density of radio echoes from meteor trails in radar type reception
the echo density is evaluated taking account of trail orientation
the meteor evaporation process and the characteristics of the transmitter
receiver system used for back scatter reception
   /
10278
volume density of reflection points of meteor trails in radio links
the procedure developed for back scatter systems above is applied
to the case of forward scatter links
   /
10279
geomagnetic crochet of november discussion of the geomagnetic and
ionospheric effects of a large solar flare
   /
10280
a possible explanation of observed at high geomagnetic latitudes
an explanation of is given in terms of hydromagnetic waves propagating
along the geomagnetic field lines
   /
10281
the scientific uses of earth satellites  a survey is given of the
effect of the use of artificial satellites on measurements relating
to the gravitational field the atmosphere the upper ionosphere magnetic
fields near  o the earth and in interplanetary space and the zones
of trapped radiation
   /
10282
on simulation studies of motion of bodies in ionized atmosphere
the problems involved in laboratory model studies on satellite motion
in an ionized z atmosphere are analysed  scaling relations obtained
satisfy the conditions for aerodynamic magneto hydrodynamic and electrodynamic
similitude  flight conditions corresponding to the earths
upper atmosphere can be simulated by suitable scaling of  he test
model
   /
10283
on the long period lunisolar effect in the motion of the artificial
satellite  formulae for the determination of long period effects
caused by the sun and moon on the motion of satellites and the stability
of their orbits are developed
   /
10284
rapid variations of the rotation period of the second soviet artificial
earth satellite with respect to the transverse axis  a table is given
of data on the rotation period during march april
   /
10285
determination of the vertical distribution of ozone by satellite
photometry  june
   /
10286
density of the upper atmosphere determined from satellite orbits
and its variation during  calculations from the orbits of satellites
in the height range show a decrease in density as the sunspot activity
declined between and  the influence of latitude on density and the
large day to night variation above are also considered
   /
10287
satellite sounder and telemeter chart ionosphere electron density
a satellite borne ionosonde is described which is to be launched
into a orbit by the usa  measurements will be made on six log spaced
frequencies between and by transmitting pulses of each frequency
in turn crossed dipole receiving aerials are connected in phase quadrature
and the receiver is arranged to receive echo pulses of one polarization
and then pulses of opposite polarization  a transistorized transmitter
gives z peak power of with pulse length  data will be recorded
by the satellite and transmitted on command to ground stations
   /
10288
the atmospheric density in the earths ionosphere and exosphere  the
atmospheric density distribution in the exosphere and the f layer
as determined from satellite observations is plotted and causes of
density fluctuations with height are briefly discussed
   /
10289
rate of ion atom interchange  conclusions about the rate of conversion
of atomic ions into molecular ions in the ionosphere are reiterated
and an alternative suggestion of june is discounted
   /
10290
density fluctuations in a plasma in a magnetic field with applications
to the ionosphere  general expressions are derived for the fluctuations
in density of electrons ions and net charge in a plasma in thermal
equilibrium in an external magnetic field  coulomb interaction and
two body collisions are taken into account  the total scattered power
and doppler spectrum is calculated for incoherent scatter from the
ionosphere at with a radar at mcs  the total power is unaffected
by the magnetic field but resonance peaks at multiples of the ion
gyro frequency appear in the spectrum when the radar beam is within
of orthogonality with the field lines
   /
10291
extensions of the chapman theory of layer formation  an attempt has
been made to establish some of the theorems necessary for the extension
of the chapman theory of layer formation to the case where a spectrum
of ionizing radiation acts on an atmosphere with any temperature
profile  some invariant properties of the electron production function
have been established and they have proved useful in estimating the
temperature and temperature variations in the ionosphere
   /
10292
theory of electrostatic fields in the ionosphere at polar and middle
geomagnetic latitudes  analysis of the elongated es fields which
provide the coupling in the dynamo motor concept of the e and f regions
the es field is taken to be of arbitary horizontal scale and numerical
solutions are determined for the attenuation of the field wi  h a
horizontal scale as small as or can extend from to height with a
reduction of only about but the coupling efficiency is critically
dependent on ionospheric conditions
   /
10293
photoionization heating in the f region of the atmosphere  an estimate
of the total f region heating due to photoionization is made based
on a comparison of theoretical and observed models of several atmospheric
parameters  the heat flux due to photoionization is estimated
to be approximately erg cm sec which would be a major if not predominant
source of heat in this region
   /
10294
observations on the ionospheric f layer at night part height of maximum
ionization critical frequency and semi thickness of f layer at night
measurements taken at cambridge england agree with those for other
stations  the scale height determined from the semi thickness of
the layer is too small when compared with rocket and satellite observations
   /
10295
group and phase velocities of a travelling disturbance in the f region
of the ionosphere  the disturbances cause gross distortions of ionogram
records and have a velocity of about min  they are associated with
sporadic e patches having a velocity of about which is the phase
velocity of the disturbances
   /
10296
on vertical drift velocities of the f layer  vertical drift velocities
in the f layer are deduced by evaluating the equation of continuity
of electron density and compared with observed movements  some correlation
is found
   /
10297
a statistical study of ionospheric drifts measured by the radio star
scintillation technique  the method gives the ew component of the
drift velocity throughout the day  this component is commonly found
to reverse suddenly near but the complementary reversal occurs at
a less definite time during the following day
   /
10298
rocket measurements of flayer electron density and their interpretation
theoretical considerations about the shape of the electron density
profile near the f peak are compared with data obtained from rockets
of march the results are consistent with day and night temperatures
of about an respectively  numerical values of the loss coefficient
and other parameters are given
   /
10299
an ion trap measurement of the ion concentration profile above the
f peak  the results of a winter evening rocket flight give the ion
concentration from to and indicate a constant scale height above
   /
10300
an annual variation of the density of the upper atmosphere of the
earth  the various causes of the fluctuations of upper air densities
see of june which result in observed changes of satellite orbits
are discussed  the possible influence of interplanetary matter and
of an interstellar wind is mentioned
   /
10301
active high frequency spectrometers for ionospheric sounding part
numerical recording of delay times  equipment for the automatic determination
and printing of echo heights in numerical form is described
   /
10302
active high frequency spectrometers for ionospheric sounding part
methods of automatic determination of true height  the direct evaluation
of profiles from the echo delays measured a the output of an ionosonde
is proposed  three digital and three analogue methods are discussed
and block diagrams given
   /
10303
density in a planetary exosphere
   /
10304
evidence on the laminar nature of the exosphere obtained by means
of guided high frequency wave propagation  radar pulses at were transmitted
in the direction of the earths magnetic field from washington
dc  delayed echoes were found on many occasions from distances between
and km  each echo remained at a constant range  a possible explanation
is given
   /
10305
orientation of polar auroras  observations of homogeneous arc auroras
at three antarctic stations are presented and show a diurnal variation
of orientation thus supporting the observations of weill vol
   /
10306
the east west drift of auroral forms determined from all sky camera
films
   /
10307
thickness of an active auroral curtain
   /
10308
models of auroral ionization part auroral ionization models and their
radio reflection characteristics  several general models of auroral
ionization are developed  by considering the ionization as an assembly
of scattering centres it is possible to include a unified treatment
of weak scattering and critical reflection
   /
10309
models of auroral ionization part applications to radio observations
of aurora  the radio reflection characteristics are examined in the
light of the theory developed in above  critical reflection at implies
electron densities up to electrons cm  the observations are consistent
with the electrons elongated in the ratio of or parallel to the field
lines and a few metres in diameter perpendicular to the field
   /
10310
atmospheric noise levels from to kilocycles per second  a comprehensive
series of observations on atmospheric noise in california and florida
for frequencies below is described and analysed  the diurnal variation
for loop orientation is a minimum in the interval at both sites and
minimum noise levels are found to occur between and  the latter result
is in agreement with the theory of wait of
   /
10311
a study of whistling atmospherics part occurrence  results of igy
whistler observations at brisbane adelaide hobart and macquarie island
are presented and the seasonal diurnal and latitude variations of
incidence of occurrence are discussed
   /
10312
a study of whistling atmospherics part diffuseness  diffuseness defined
as the average time duration of whistler energy on a fixed frequency
is found to be twice as large for long as for short whistlers to
be independent of season and time of day and to be linearly related
to geomagnetic latitude and whistler dispersion
   /
10313
observations of hydromagnetic emissions  a frequency time analysis
of geomagnetic pulsations was made in the range for the period november
the oscillations were observed simultaneously in california and nevada
and were probably influenced by solar flares which occurred before
and during the dates mentioned
   /
10314
two hop whistler mode echoes received at seattle
   /
10315
complex plane charts for obtaining closed loop frequency responses
in linear control systems  summary of graphical methods for plotting
complex plane charts
   /
10316
outside coil magnetic head improves high frequency recording  high
resolution is obtained as a result of smaller air gaps and an improved
field configuration
   /
10317
replacing sine wave sources with solid state inverters  a series magnetic
amplifier f or a saturable reactor is used following a solid state
inverter to give a modified square wave output such that the heater
and direct voltages available are the same as would be obtained from
a sinusoidal ac supply
   /
10318
converter efficiency and power output of a tunnel diode relaxation
oscillator  a simple dc ac converter is discussed
   /
10319
control of frequency and phase displacement in transistor converter
circuits by means of rc networks  a new type of adjustable frequency
transistor converter is described in which the operating frequency
is controlled by a rc network and is independent of the direct voltage
power regulation by means of rc phase control of a pair of transistor
converters is discussed
   /
10320
controlled rectifier produces quarter megawatt pulse power  circuit
details are given of pulse generator equipment using solid state
devices as active elements  a pnpn si controlled rectifier acts as
the switch and two layer and four layer diodes are used in the trigger
generator
   /
10321
recent developments in selenium rectifiers  an account of phenomena
occurring during the construction and operation of different types
of se rectifier
   /
10322
a note on transistorized ripple filters  a smoothing circuit providing
optimum efficiency over a wide range of load currents is described
   /
10323
digital computers  annual review of developments in computer design
with descriptions of recent installations and tabulated performance
data
   /
10324
notes on the structure of logic nets  an elementary approach to a
theory of the role of structure in logic nets
   /
10325
the main store of a digital differential analyser  a description
of the performance and circuits of the main store of corsair
   /
10326
a potential microwave compu  er element  a bistable oscillator frequency
script system is described which uses a tunnel diode as the active
element  a switching time of the order of cycles is required for
resonance frequencies of  operation at has been demonstrated and
operation at is suggested
   /
10327
new thermally variable bead resistor  the unique characteristic of
ion doped is illustrated  a bead in diameter dissipated in still
air
   /
10328
equivalent circuits of coils with distributed capacitances  the equivalent
circuit comprises an ideal coil a certain number of positive
capacitances two in the case of a coil with one winding and an additional
capacitance which can be either positive or negative depending
on the relative magnitude and the exact distribution of the various
parasitic capacitances
   /
10329
on the core gain of the magnetic amplifier cores  new definitions
specific core gain and core gain are suggested and the relation of
these to the power gain of an amplifier is discussed
   /
10330
an experimental study on the ampere turn gain of ordinary saturable
reactors  measurements show that great improvements in performance
of dc instrument transformers can be obtained by slightly increasing
the effective ratio of primary to secondary turns and applying a
properly rated ac bias circuit
   /
10331
on the linear circuit aspects of cryotrons  an expression is derived
for the gate resistance of a cryotron in the transition region
   /
10332
variable conductance sampling switch  weighted sums are produced
of discrete samples from continuous voltage waveforms by varying
the rate at which the integrating capacitor can charge  the switch
has been operated randomly and cyclically at rates between and sec
   /
10333
the silicon cryosar  the main difference from the ge cryosar of is
that negative resistance characteristics are obtained using crystals
with uncompensated impurities  as a computer element the device has
been switched in about and has a maximum minimum voltage ratio as
high as
   /
10334
ire standards on solid state devices definitions of terms for nonlinear
capacitors
   /
10335
on some aspects of matrix calculus applied to local oscillation in
nonlinear circuits  the application of matrix methods to the analysis
of oscillating circuits with an impressed signal of lowamplitude
is considered  the representation of amplitude and phase modulation
in co ordinate form is illustrated and examples are given of the
use of these methods in problems of oscillator stabilization
   /
10336
elliptic functions in network synthesis  the jacobian elliptic functions
are used to solve the approximation problem of network synthesis
a unified design chart for image parameter filters elliptic function
filters and phase difference networks is shown and tabular and graphical
data emphasizing extreme parameter values are given
   /
10337
shaping of distributed rc networks  an improvement in the attenuation
factor of a phase shift network from to appears to be possible if
the conventional uptapered section network is replaced by a tapered
distributed network
   /
10338
graphical procedures for solving the approximation problem of electrical
filters  three graphical methods of synthesizing filter response
characteristics as the sum and difference of functions of similar
geometric form are explained  the methods are theoretically equivalent
but have different fields of application  for english version see
   /
10339
optimum matching of symmetrical low pass and high pass filters application
to low pass and high pass ladder filters using piezoelectric
crystals  a filter structure is suggested which is especially suitable
for use with crystal elements  advantages and disadvantages of this
and similar structures are discussed
   /
10340
tunable rejection filters  an analysis of the requirements for a
rejection filter is used in the design of some practical circuits
tunable over half an octave and covering the hf band
   /
10341
vhf broad band variable group delay equalizers  the two designs described
are for links using telephony channels or line subcarrier colour
television telephony channels or line subcarrier colour television
   /
10342
application of graph theory to the analysis of active and mutually
coupled networks  a unified graphical approach applying the concept
of the mathematically equivalent circuit of as it relates to the
indefinite admittance matrix of a multipole
   /
10343
stable low noise tunnel diode frequency converter an initial wide
band converter with local oscillator frequency and intermediate frequency
had unity conversion gain and a radiometer noise figure of
   /
10344
self oscillation in a transmission line with a tunnel diode  a theoretical
analysis of the circuit is given together with experimental results
the self oscillation can be explained as a periodic solution of the
linear wave equation with a nonlinear boundary condition
   /
10345
broadening of the spectrum of an oscillator due to noise  a formula
is derived for the frequency broadening due to random thermal noise
in a nonlinear circuit
   /
10346
pulling phenomena in valve oscillators  a general  theory of pulling
effects is derived on the basis of band filter theory  these effects
are calculated as a function of detuning and degree of coupling between
similar and dissimilar oscillator circuits  a mechanical analogue
of a pulled oscillating system is described
   /
10347
varistor network controls voltage tuned oscillator  an af phase shift
oscillator with varistors as the variable elements has almost constant
output over a range of and low harmonic distortion
   /
10348
locking of a two circuit oscillator  the addition of a second tuned
circuit improves the amplitude frequency and phase frequency characteristics
of a locked oscillator  the effect of coupling conditions on
stability is s discussed
   /
10349
recent development of quartz crystal units for telecommunication
a new method and equipment devised for manufacture and development
of crystal units in the range and associated apparatus are described
   /
10350
tunnel diode one sho  and triggered oscillator  th one tunnel diode
flip flop described by kaenel of june which requires a bidirectional
pulse can be made to operate as a triggered oscillator the switching
mechanism of the schmitt trigger circuit using transistors  equivalent
circuits and characteristic curves ar derived results of measurements
are given for comparison  by the addition of an identical circuit
with modified bias
   /
10351
the tunnel diode pair  the composite characteristic of the twin circuit
is considered and its application in the design of astable monostable
and bistable multivibrators is illustrated trigger requirements and
effects of loading can also be determined
   /
10352
a low level linear rundown circuit for pulse height to pulse width
conversion  a two transistor device consisting of a constant current
generator and an emitter follower circuit is described  experimental
and theoretical analysis of the circuit are in good agreement
   /
10353
tunnel diode fast step generator produces positive or negative steps
the generator produces pulses of about duration having a rise time
of at recurrence frequencies up to
   /
10354
the collector coupled complementary pair  the astable mode gives
phantastron type waveforms with peak to peak voltages almost equalling
the supply voltage  the bistable md mode gives thyratron type characteristics
   /
10355
fast coincidence circuits using avalanche transistors  the circuit
described has a resolution time of and an efficiency of  results
of tests made with a pulse generator and a pair of photomultipliers
are reported
   /
10356
an automatic self checking transistor counter with digital display
   /
10357
a fast binary counter  a transistor binary counter employing seven
flip flops is described  its operation is dependent only on the switching
time of one flip flop which may be
   /
10358
a tripler circuit using a capacitance diode  mathematical analysis
of a frequency tripler circuit and derivation of an equivalent circuit
the results of the analysis and of measurements on a practical circuit
are compared
   /
10359
the pulse response of a delay line  an expression is developed for
each element of the network and a solution is obtained in the form
of a convergent neumann series
   /
10360
zener diode creates logarithmic pulse amplifier  amplification over
three decades is achieved by using as the logarithmic device a zener
diode to which a small resistance has been added to straighten the
characteristic curve
   /
10361
note on the series correction of wide band amplifiers  a variation
of the series inductance correction circuit is considered in which
the load resistance is connected across the output and the circuit
designed for either maximally flat transfer impedance or maximally
flat input impedance  inconvenient ratios of input t output capacitance
can be avoided by using a cathode follower stage
   /
10362
a new magnetic controlled rectifier power amplifier with a saturable
reactor controlling on time
   /
10363
problems relating to transistor power amplifiers  the design of transformerless
af output amplifiers is considered and a graphical method
for determining transistor thermal stability is given
   /
10364
a circuit for the compensation of voltage drift in the input stage
of a direct coupled transistor dc amplifier  in the circuit given
the temperature drift of the base emitter voltage has been compensated
almost to the theoretical limit
   /
10365
differential amplifier with regulator achieves high stability low
drift  a transistor dc amplifier suitable for missile tl telemetry
systems is described
   /
10366
narrow band amplification with transistors  contribution to of with
authors reply
   /
10367
field swept maser oscillation  the application by singer and want
of september of their analysis of maser oscillations to experimental
results of the author is criticized  they attribute the oscillations
to energy exchange between cavity and emitting sample  th radiation
envelope is however largely determined by the zeeman field sweep
rate due to a different mechanism
   /
10368
paramagnetic maser oscillator analysis  an equation for the output
waveform is derived and numerical solutions obtained using a computer
good agreement with experiment is given for steady state and field
swept oscillators
   /
10369
project echo the dual channel travelling wave maser  details of the
ruby material isolator and amplifier package construction are given
an instantaneous bandwidth of and effective noise temperature of
were obtained and the gain was sufficient to override the noise of
the following stage
   /
10370
parametric amplifiers  theoretical comparison of gain bandwidth noise
and stability of the negative resistance amplifier and upper or lower
sideband converters  experimental results are also reported for english
version
   /
10371
the wide tuning range of backward travelling wave parametric amplifiers
a method is indicated of increasing the range beyond that suggested
by staus vol
   /
10372
theory of nonreciprocal circuits with equal input and output frequency
using nonlinear semiconductor elements  the quadripole equations
and transfer gain are derived for nonreciprocal amplifiers which
consist of tunnel diode or parametric diode converter stages in cascade
connection see also of january  matching and decoupling problems
are considered for various circuit configurations
   /
10373
signal and noise characteristics of diode reactance amplifiers for
the uhf region  examples are given of mixer circuits straight amplifiers
and a travelling wave amplifier using parametric amplifier techniques
the problem of matching by means of nonreciprocal elements or by
bridge circuit i also dealt with
   /
10374
noise and stability of negative conductance amplifiers  calculations
of lowest noise figure attainable from stability considerations are
in agreement with results of an earlier analysis of but the lowest
possible noise figure is obtained at the expense of stability
   /
10375
project echo lower side band up converter for satellite tracking
radar  the amplifier is pumped at and although regenerative it has
been made conditionally stable by careful mechanical and electrical
design  the overall noise figure is gain and bandwidth
   /
10376
a tunnel diode slot transmission amplifier  a negative conductance
waveguide transmission type amplifier consisting of a tunnel diode
mounted within an s band waveguide end plate slot has been built
operating at a frequency of with a bandwidth of and gain  no measurements
have yet been made of noise figure
   /
10377
the matching problem of the ring type and double push pull modulator
with filter termination at both ends  detailed discussion of an impedance
matching method for obtaining optimum frequency response and minimum
attenuation
   /
10378
a ring modulator with integrated filters  a losslrdd four terminal
frequency translating network is proposed which avoids using a transformer
between rectifiers and filters
   /
10379
theory of photoexcitation in solids  the theory of optical absorption
by photo excitation is reviewed and further investigated  a distinction
is made between oblique and vertical transitions
   /
10380
tunneling from an independent particle point of view  calculation
of wave functions for tunnelling problems with applications
   /
10381
radio frequency breakdown controlled by drift of electrons in an
inhomogeneous magnetic field  measurements of breakdown rf electron
field versus magnetic field were made at pressures between and in
and  the breakdown field varied as the inverse square root of the
magnetic field as predicted by theory
   /
10382
experimental evidence for beam plasma interaction in a low pressure
argon discharge
   /
10383
broadening of a beam of electrons by the space charge  a recurrence
formula is developed for computing the broadening of the beam
   /
10384
filamentary structure produced by an electric current in a plasma
an electric field parallel to a magnetic field in a plasma at low
pressure produces a current which is confined to a filament  simple
formulae are given for the cross section of the filament and the
current in it
   /
10385
space dispersive properties of plasma
   /
10386
interaction of fast electron beams with longitudinal plasma waves
equations are derived for the variation with time of the plasma wave
spectral density and the fast electron distribution function for
arbitrary velocity distributions
   /
10387
waves in a rarefied ionized gas propagated transverse to an external
magnetic field  three modes of plane waves in which the perturbed
magnetic field is parallel to the external magnetic field can be
propagated transverse to the external magnetic field in a collision
free and fully ionized gas  in the hf limit the three modes behave
respectively as em electron sound and ion sound waves
   /
10388
concerning the disturbances produced by a body moving in a plasma
formulae derived for the disturbance of electron density are used
to calculate the effective cross section for the scattering of em
waves at this disturbance in particular cases
   /
10389
electrohydromagnetic waves in a fully ionized gas  part  the appleton
hartree dispersion formula for magneto ionics is generalized to
include the effect of heavy ions  the ratio of particle energy to
magnetic field energy in a wave of arbitrary frequency is determined
a band of frequencies around the plasma frequency is found for which
waves are attenuated  location of these bands would enable the interplanetary
magnetic field and electron density to be estimated
   /
10390
the statistical mechanics dynamics and magnetohydrodynamic of plasmas
a system of equations is established in particular to denote the
movement the current and the compression tensor of an ionized gas
these are applied to partially and completely ionized gases and used
to obtain the general equations of magneto hydrodynamics  propagation
modes of different types of wave are determined
   /
10391
on plasma oscillations with special emphasis on the landau damping
and the gross gaps in the frequency spectrum  a linear theory of
oscillations of the form in a collision free electron plasma in an
external magnetic field is given
   /
10392
collective motions in a plasma due to magnetic interaction  the existence
of collective modes due to the static magnetic interaction between
the current elements represented by the moving electrons has been
investigated
   /
10393
plasma density fluctuations in a magnetic field  a continuation of
earlier work in which the frequency spectrum was derived for the
spatial fourier transform of the electron charge density fluctuations
in a plasma  the effects of a constant magnetic field in an arbitrary
direction are considered  a theoretical basis is provided for analysing
back scatter experiments and intensities are derived a function of
the real frequency variable for the case of thermodynamic equilibrium
   /
10394
hydromagnet a self generating liquid conductor electromagnet  the
exciting current is generated by forcing a liquid conductor radially
inwards across an axial magnetic field  the tangential current thus
generated adds to the initial applied field
   /
10395
emergence into vacuum of the cherenkov radiation produced by longitudinal
waves in a medium  the em radiation of an electron moving into
a vacuum from a medium with spatial dispersion is considered  under
certain conditions in addition to the transition radiation there
is cherenkov radiation from longitudinal waves in the medium  at large
distances from the interface this radiation is a spherical wave confined
to a narrow range of frequencies near the plasma frequency
   /
10396
coherent generation of microwave power by annihilation radiation
of a prebunched beam  millimetre wave radiation at the level has
been produced by the creation and annihilation of a tightly bunched
electron beam  a proposed extension of the method based on optical
techniques is intended to produce power in the submillimetre region
   /
10397
the problem of diffraction of electromagnetic waves at a perfectly
conducting plane ring  theoretical treatment of the diffraction of
plane em waves assuming a ring of internal radius and width much
greater than the wavelength  integral equations for the shadow currents
are given from which the total current flowing in the screen is determined
   /
10398
diffraction of a plane wave by a unidirectionally conducting half
plane  the problem is formulated in terms of an integral equation
specifying the screen function whose solution is obtained by the
standard wiener hopf procedure  expressions for the fields and the
current induced on the half plane are given
   /
10399
a note on the diffraction of a scalar wave by a small circular aperture
   /
10400
kinetic theory of reflection of electromagnetic waves from a moving
plasma  mathematical analysis of the reflection of em waves from
a plasma moving in a space in which the phase velocity of the waves
is less than the velocity of light
   /
10401
scattering of microwaves from a cylindrical plasma in the born approximation
part  formulae are derived for the angular distribution function
and the effect of special distributions is considered
   /
10402
some properties of resonance line shape functions  mathematical discussion
of the broadening of spectral lines
   /
10403
shift of nuclear quadrupole resonance frequency by electric field
a linear shift in the line in is observed when a field of several
is applied parallel to the crystal axis  the line shape becomes asymmetric
and is attributed to unresolved line splitting
   /
10404
linear effect of applied electric field on nuclear quadruple resonance
a linear stark effect is observed in the line in and crystalline
powders as predicted theoretically
   /
10405
linear effect of applied electric field on magnetic hyperfine interaction
   /
10406
angular variation of axial spin hamiltonian eigenvalues in strong
magnetic field  the expressions for the energies of transitions between
levels with strong field quantum numbers m and m the tables give
the values of the coefficients containing and for a range of values
of these parameters
   /
10407
a proposal for a tunable source of radiation for the far infrared
using beats between optical masers
   /
10408
theory of quantum oscillators in a multimode cavity the distribution
of power in the various modes in the steady state operation of an
optical maser is studied
   /
10409
shhsrroposed technique for modulation f coherent light  a frequency
shift of the coherent light output proportional to the strength of
an electric field applied to a ruby laser provides a system for fm
of the output
   /
10410
studies in cosmic radio noise at bungalore  the techniques in use
at banalore for a radio survey of the sky and the disturbed sun at and
are described
   /
10411
interpretation of cosmic noise measurements at from satellite and
the analysis given is based on the assumption that observed variations
in signal strength were due to three causes variation of radiation
resistance o the aerial with the dielectric constant of the surrounding
ionosphere restriction of the angular aperture at the aerial due
to ionospheric refraction and polarization and variation of cosmic
noise power over the sky
   /
10412
oscillations in the refraction of radio waves emitted by the sun
radio astronomy observations at sunrise in november and december
at wavelengths of and showed a periodic variation of ionospheric
refraction with uniform change of zenith distance of the sun  this
variation is analysed in terms of sunspot activity and the motion
of cellular waves in the ionosphere see of
   /
10413
lunar temperature measurements at
   /
10414
distribution brightness in extragalactic radio sources  measurements
have been made at both on and base lines with a resolution of about
interpretations are given of the asymmetry observed in sources
   /
10415
the radio source hercules a  interferometer observations were made
at on the two components of the intense source  the separation in
declination is
   /
10416
central component of the radio source centaurus  observations made
ith a variable spacing interferometer at and show that the radiation
originates outside the wide dust band
   /
10417
flux and energy spectra of  he protons in the inner van allen belt
   /
10418
energy spectrum of electrons trapped in the geomagnetic field  solutions
of the fokker planck equation for th electron distribution function
are obtained by reducing the equation to an eigenvalue problem  the
spectrum obtained with a source of decaying albedo neutrons is at
variance with the observed result
   /
10419
characteristics of the van allen radiation zones as measured by the
scintillation counter on explorer  results were obtained over a period
of four weeks from a counter recording fluxes of electrons above
and protons above a geomagnetic storm which occurred about a week
after launching the satellite produced an immediate increase in the
counting rate large fluctuations in particle intensity were observed
at the d edge of the outer van allen belt during the storm which
were closely related to simultaneous geomagnetic activity
   /
10420
on meteor ablation in the atmosphere  improvements to the usually
adopted theory are given and approximate expressions suggested for
the fundamental equation of ablation of low velocity meteors
   /
10421
reduction of meteor velocities from continuous wave radio records
an analysis of the reduction technique used at ottawa shows that
in velocity measurements any statistical bias was positive and less
than
   /
10422
some studies of geomagnetic micropulsations  recordings made at four
stations in australia are analysed  the period of the continuous
type of oscillation increases with latitude and also varies diurnally
the damped trains of oscillations occurring mainly near midnight
are followed by magnetic bays with an average delay of about min
effects observed during magnetic storms are discussed
   /
10423
some features of magnetic storms in high latitudes  ionospheric
currents in high latitudes during magnetic disturbances are deduced
from magnetic data  lists of disturbances during and prior to the
igy are given
   /
10424
the national program for lunar and planetary exploration  an illustrated
description of the ranger and other planned spacecraft
   /
10425
excitation of plasma waves by bodies moving in ionized atmosphere
an ionized cloud formed in front of a rapidly moving body excites
waves by interaction with the ambient plasma  extraordinary em waves
are generated in the presence of a suitable weak magnetic field
   /
10426
on the interplanetary magnetic storm pioneer  a magnetic field of
to was detected by pioneer perpendicular to the sun earth line during
periods of intense solar activity between march and april  quiet
time fields of were observed on other occasions
   /
10427
magnetic storms in interplanetary space as observed by pioneer v
a positive correlation is found between the interplanetary field measured
at the satellite and the planetary magnetic index during the flight
of pioneer from launch on march to the end of april  magnetic storms
at the satellite occur at the same time as earth storms although
there is a slight delay towards the end of the period of telemetry
   /
10428
satellite flashing light system  to provide increased accuracy of
the determination of the position of a satellite a coded flashing
light system could be carried  design details are given
   /
10429
effect of an oblate rotating atmosphere on the orientation of a satellite
orbit  for inclinations of in particular significant rotation
of the major axis in the orbital plane occurs due to the atmosphere
   /
10430
atmospheric phenomena noted in simultaneous observations of  events
occurring in three typical revolutions of sputnik are described measurements
were made on the transmissions  i signal drop outs due to transmitter
failure were noted and another type of signal decrease was attributed
to localized absorbing regions  regions of the ionosphere causing
scintillation were also identified they have an extent in the horizontal
plane of several hundred km
   /
10431
methods of calculating atmospheric densities from satellite orbit
data  formulae relating atmospheric density to the rate of change
of period of a satellite as obtained by various workers are reviewed
and are shown to be in sufficient agreement to meet practical needs
   /
10432
ray paths from a cosmic radio source to a satellite in orbit  a satellite
above the maximum can receive radiation on frequencies that are
totally reflected by the ionosphere  two effects of reflection in
the upper part of the ionosphere are discussed focusing and interference
both occur particularly when s a satellite enters or leaves a
region in which it can receive radiation from a point source in space
   /
10433
measurement of solar x radiation  the x ray emission measuring equipment
to be carried in skylark rockets and the satellite is described
both x ray flux and spectral shape are to be investigated
   /
10434
local electron densities deduced from the faraday fading of satellite
transmissions using measurements during two consecutive transits
in the analysis it is assumed that during the period of revolution
of the satellite the relative gradients of the local electron density
are constant at  he same altitudes and the changes in density above
the maximum are the same as those within the f layer  daytime observations
of in september have been analysed
   /
10435
scintillations and the latitude distribution of ionospheric irregularities
evidence is given in support of kents interpretation of the
rapid fading of earth satellite signals of  mawdsleys alternative
explanation of scattering by field aligned irregularities of is not
confirmed by experiment
   /
10436
radio tracking of artificial earth satellites
   /
10437
tracking and display of earth satelli  es
   /
10438
charged particles in the upper atmosphere  a comprehensive review
of collision processes involving charged particles in  he upper atmosphere
   /
10439
structure variations and measurements of the earths ionosphere and
exosphere  a survey of present knowledge and work being conducted
at the technion israel institute of technology haifa
   /
10440
the distribution f minor ions in electrostatic equilibrium in the
high atmosphere  a simple discussion of the factors which govern
the distribution of ions in diffusive equilibrium  the scale height
of the predominant ions is twice that of the corresponding neutral
constituent and the concentration of a minor light ion can increase
with altitude
   /
10441
comments on tidal winds in the high atmosphere  the accuracy of published
data on tidal wind variations are discussed on the basis of computations
of the indices of the probable error circle variations with
seasons and elevation are real although their magnitudes may be unreliable
   /
10442
diffusion in the ionosphere a review of some recent work  work by
gliddon and kendall of shows considerable support for the hypothesis
that f and f regions are produced by the same source of ionization
   /
10443
the lunar variation of the virtual height of the normal ionospheric
e layer above fribourg  a semi diurnal lunar variation of has been
detected with a maximum at lunar time
   /
10444
theory of overhead nonblanketing sporadic e  sequences of curves
are calculated for an e layer in which a horizontal stratum of irregularities
thick is slowly descending  the results are very similar to
recorded sequences of ionograms showing sporadic e
   /
10445
observations on the ionospheric f layer at night the law of electron
loss in the f layer  at night electrons in the f layer are lost by
attachment like processes  the loss coefficients are of the form
where is the height at which and is the scale height of the loss
coefficient  assuming the loss coefficients are attributable to loss
rates in chemical processes values correspond to those of molecular
oxygen and nitrogen
   /
10446
equatorial spread f in relation to post sunset height changes and
magnetic activity  the seasonal dependence of the correlations is
found and the data are considered in relation to maryns theory of
the formation of spread see of
   /
10447
on the relation between magnetic storm and ionospheric disturbances
that occurred on sept  th patterns of dense e blackouts and f layer
disturbance in the northern hemisphere are compared with the current
systems of geomagnetic disturbance at different stages of the storm
with the development of polar cap blackout  several hours before the
sudden commencement of the storm a current system was produced in
the polar cap region  during the main phase blackouts and e coincide
with strong currents at auroral latitudes
   /
10448
upper atmospheric turbulence near the level  an examination of observations
of a sodium trail produced by a veronique rocket in the upper
atmosphere
   /
10449
hydrogen atoms and ions in the thermosphere and exosphere  the structure
of the atmosphere between and is discussed in terms of various models
for a further note on the temperature in the exosphere
   /
10450
variable conditions of the terrestrial exosphere  the well known
features of atmospheric density variations as deduced from satellite
observations are discussed  data for at least ten satellites show
evidence of an annual variation in atmospheric density with a minimum
in july the amplitude of the variation increasing with altitude
   /
10451
exospheric electron density variations deduced from whistlers  new
data on electron density are presented  density is approximately
proportional to the strength of the earths magnetic field  an unexplained
annual variation in which the december value is nearly twice that
in june
   /
10452
altitudes of the night airglow radiations  observational methods
for obtaining the layer heights of airglow emission are briefly reviewed
and results derived from ground measurements rocket flights and kinetic
temperatures are discussed
   /
10453
attempt to measure night helium glow evidence for metastable molecules
in the night ionosphere  a rocket experiment intended to measure
the intensity of night time he glow wavelengths and gave negative
results but provided some evidence for the existence of metastable
molecules above km
   /
10454
some auroral observations inside the southern auroral zone
   /
10455
guiding of whistlers by the magnetic field  a mechanism is proposed
which explains the wideband noise observed during whistler reception
a particle moving with velocity where is gyrofrequency and is plasma
frequency causes a wave to be propagated along the earths magnetic
field all frequency components of the wave travel with the same velocity
see of january
   /
10456
the dispersion of s whistlers compared with the geomagnetic latitudes
of their sources  observational results are presented which indicate
that the geomagnetic latitude of lightning discharges is a factor
determining the dispersion constant of the related whistlers
   /
10457
project echo antenna steering system  the use of basic orbital information
to generate aerial steering instructions for project echo is
discussed  a digital method is described in which predicted pointing
data is transmitted by teletype to the aerial site then stored and
subsequently used when required in real time to control the aerial
drive mechanism
   /
10458
project echo boresight cameras  cameras are attached to the project
echo transmitting and receiving antennas at holmdel for recording
the position of the satellite  an exposure of sec at was used at
frames sec
   /
10459
an analytical expression for describing the write process in magnetic
recording
   /
10460
video tape analyser  tape frequency response noise contribution
drop outs and rate of wear are determined and an assessment is made
of the decline in picture quality due to repeated playback
   /
10461
spectral response of solar cells  theoretical response curves are
derived by an analysis including the effects of carrier diffusion
and drift due to the electric field in the surface region
   /
10462
solar cells for communication satellites in the van allen belt  the
power output of solar cells on satellites is degraded by radiation
damage on passing through the van allen belts  methods of overcoming
this are discussed
   /
10463
power supplies for space vehicles  a comprehensive review of types
of power systems energy sources and power converters and an examination
of the problems associated with development as power supplies for
space vehicles
   /
10464
commutation and destructive oscillation in diode circuits  an investigation
of these phenomena in si rectifiers and a study of how commutation
may cause destruction of unprotected cells
   /
10465
a fatigue free silicon device structure  by using hard solder instead
of soft solder to make joints in the device raptures are no longer
produced by cyclic thermal stress
   /
10466
passive voltage and current stabilizers using a bridge network  the
residual voltage variation which occurs when a zener diode is used
as a stabilizer is removed by using a wheatstone bridge network
   /
10467
transistorized current stabilizers for electromagnets of medium power
to  methods of computing the characteristics and determining the
stability are given
   /
10468
cathode coupled cascode stabilizer circuit  in a negative hv power
supply the peak to peak ripple was less than and a change in line
voltage gave less than change in output
   /
10469
high speed analogue digital converter  details are given of a fully
transistorized unit for the conversion of pulse amplitude data to
numbers of pulses  use is made of a tunnel diode transistor combination
in the blocking oscillator circuit to produce oscillations at a frequency
of or mc  the overall dead time of the converter is reduced by
times
   /
10470
optical erasure of el pc and neon pc storage elements  a new method
of selective storage and erasure using optrons is described  a single
light source of constant intensity with emission within the sensitivity
range of the photoconductor will latch optrons with short pulses
and erase them with long pulses
   /
10471
obtaining nondestructive read out with ferroelectric memories  the
development and initial tests of a monomorphic polycrystalline ba
titanate storage cell used as a three or four terminal device
   /
10472
the magnetic flux counter  the principle and application fof multistable
magnetic storage systems are discussed
   /
10473
feedback amplification improves hall effect multipliers  a transistor
feedback amplifier supplies a field coil current in phase with the
input signal  a dc component is added to increase the common mode
signal rejection
   /
10474
a microsecond ferrite core memory  a storage capacity of bits is
achieved with an instruction repetition rate of
   /
10475
switching processes in dc circuits with nonlinear resistance and
nonlinear inductance  normalized differential equations are derived
for the analysis of switching processes involving nonlinear resistances
with semiconductor or valve type characteristics
   /
10476
design of wide ba d shielded toroidal rf transformers  details of
transformers for use with magic or hybrid junctions in the frequency
range
   /
10477
determination of core size in pulse transformer design  the construction
of a design chart is described and its application is illustrated
   /
10478
toroids of square loop ferrite material as switching elements  a
differential equation is derived wi which described magnetic reversal
processes in square loop ferrites neglecting the effect of eddy currents
the application of this analysis to practical switching circuits
is considered
   /
10479
tunnel diodes increase digital circuit switching speeds  tunnel diodes
are used with transistors in high speed switching circuits suitable
for pulse generator operation
   /
10480
application of karnaughs mirror symbols to transfluxors  a transfluxor
symbol is proposed which is based on the system used by karnaugh
of for magnetic core switching circuits
   /
10481
an analysis of a cylindrical cavity with radial vanes  the procedure
involves the use of variational methods for obtaining successively
better approximations to the resonance frequencies and the field
configuration
   /
10482
an analysis of the travelling wave cavity  the masured response of
a travelling wave cavity differs from that predicted by simple theory
an internal mismatch can explain the observed response
   /
10483
rules for the verification of the stability of normal linear negative
feedback systems  the stability criterion and rules are formulated
and the rules to polar diagrams and curves of the system function
is described
   /
10484
a filter system with favourable pulse characteristics  analysis of
filter performance under pulse conditions on the basis of the distribution
of poles and zeros of the transfer function  a practical filter
circuit is derived and the pulse amplitude calculated
   /
10485
mechanical filters with flexural coupling  the use of flexural coupling
between longitudinal resonators makes possible the construction of
very small mechanical filters for operating around the characteristics
of such a system are calculated and two practical examples are given
   /
10486
the design of filters with the aid of the catalogue of normalized
low pass filters  filter design by the insertion loss method is facilitated
by the use of tables prepared with the aid of an electronic
computer see of  the design of tchebycheff type and cauer parameter
low pass filters is considered in detail
   /
10487
diagrams for the design of double tuned band filters with arbitrary
coupling  the design curves and equations given are based on filter
parameters which can be obtained directly by measurement in the
filter circuit
   /
10488
insertion loss of electromechanical coupling filters  the insertion
loss is defined and design formulae are derived for minimising this
loss
   /
10489
experiences with mechanical band filters  problems arising in the
construction of electromechanical filters are discussed and some
practical types of filter are described
   /
10490
a crystal filter of increased bandwidth and its synthesis  the method
given in of june is applied to a lattice type filter with a crystal
in each bridge arm
   /
10491
a differentiating equalizer with transistors  the equipment described
is designed for emphasizing the upper frequencies of the video signal
band withou  phase distortion
   /
10492
a synthesis procedure for an n port network  the method is based
on the bott duffin procedure for two port networks
   /
10493
bistable systems of differential equations with applications to tunnel
diode circuits  a mathematical theory is developed for nonlinear
circuits with at least two stable steady states  the theory is applied
in detail to circuits containing one or two tunnel diodes
   /
10494
new wide range oscillator technique  a modification of the wien bridge
rc oscillator circuit is used in an instrument with a range of
   /
10495
crystal stabilized tunnel diode oscillators  theory and design procedure
is given for a oscillator with frequency stability of parts per million
per
   /
10496
one tunnel diode binary  comment on of june and authors reply
   /
10497
an analysis of the modes of operation of a simple transistor oscillator
an analysis predicting two modes of oscillation a two terminal transit
time mode and a three terminal mode
   /
10498
transistor precision pulse shaper with short recovery time  the circuit
is designed to minimize the effects of temperature changes and individual
variations in transistors  the pulse duration varied by for a
temperature range of and by in ten similar circuits
   /
10499
a neuristor prototype  a description of an electronic lumped element
model of the neuristor proposed by crane sept
   /
10500
some circuit applications of avalanche devices  applications of pnpn
avalanche diodes in analogue computers process con  rol oscillography
and telemetry are discussed
   /
10501
study of a diode bridge nanosecond resolution coincidence circuit
a highly stable circuit is described which can provide a resolution
down to
   /
10502
frequency components in the output of a harmonic generator driven
by the sum of two sine waves  a frequency analysis is given for the
output of a generator which emits a constant amplitude pulse at each
zero crossing of the input voltage consisting of the sum of two sine
waves raised to an arbitrary dc level
   /
10503
a random pulse generator with variable mean rate method of producing
a random pulse train with predetermined statistical properties
   /
10504
amplifier for the generation of accurately controlled microsecond
pulses  a description is given of a pulse amplifier whose output
voltage can be accurately controlled by the setting of a ten turn
potentiometer  the output amplitude and pulse lengths are variable
up to and respectively
   /
10505
designing hybrid dc amplifiers to withstand missile environments
the amplifier comprises one valve and si transistors and is based
on the goldberg principle for dc drift correction
   /
10506
actual noise measure of linear amplifiers  a new noise measure is
proposed which includes the noise contribution from the load  it
is of particular use in comparing amplifiers whose terminations are
not necessarily optimized
   /
10507
automatic gain control for super regenerative amplifiers  the circuit
gives stable operation for long periods and maintains output pulses
constant over a range of input signals
   /
10508
nonadiabatic behaviour in a low frequency beam type maser  characteristics
are discussed theoretically when the adiabatic focusing approximation
travelling wave maser using chromium doped rutile  the active
material is of small cross section and is connected to standard size
x band waveguides by dielectric tapers  performance figures quoted
show appreciable gain per unit length with a very large tunable bandwidth
obtained without the use of any external sh slowing structure
   /
10509
maser action in emerald  the successful operation of a single cavity
reflection type maser amplifier at using synthetic emerald is reported
   /
10510
maser action in ruby by off resonance pumping  population inversion
peaks have been observed using a pump frequency as much as from the
centre frequency  the experimental results are discussed and explained
   /
10511
the maser and its application to satellite communication systems
the properties of the travelling wave maser with a comb structure
are discussed with particular reference to the frequency range  performance
is estimated and compared with a parametric amplifier in a practical
aerial system
   /
10512
a tunable reactance type straight amplifier for the uhf range  an
experimental variable capacitance amplifier tunable in the range
with a pump frequency of is described  with a bandwidth the noise
figure is better than that obtainable with a conventional earthed
grid triode amplifier
   /
10513
gain saturation in a travelling wave parametric amplifier  there
is a periodic transfer of power along the line between signal idler
and pump frequencies see of  the resultant reduction in gain with
increase of signal strength is shown graphically
   /
10514
parametric amplification with transistors  a note on the operation
and characteristics of a parametric amplifier using transistors operating
beyond cut off frequency
   /
10515
microwave amplification in electrostatic ring structures
   /
10516
on the cascaded tunnel diode amplifier  a mid band equivalent circuit
of an artificial transmission line is described for use with tunnel
diodes in cascade amplifiers see  only one diode is needed in each
stage and the shunt resistor is an ordinary passive component
   /
10517
the electrostatic field in metals particularly at a surface against
an insulator
   /
10518
quantum theory and transverse galvanomagnetic phenomena  a quantum
theory of electrical conduction in crossed electric and magnetic
fields is given for the limit of very weak scattering
   /
10519
a gas discharge generated by micro waves which glowes free in space
at the focus of a closed ellipsoid of revolution  better results
were obtained than in earlier experiments
   /
10520
electric field induced anisotropies in an inhomogeneous plasma  anisotropies
in electron diffusion and conductivity can be produced in the
absence of a magnetic field
   /
10521
nonlinear time dependent plasma oscillations  the laplace transform
technique used to solve the the problem of the first order motions
in an unbounded rarified electron plasma is modified to solve the
problem to arbitrarily high order
   /
10522
some boundary value problems involving plasma media a plasma consisting
of a neu  ral mixture of electrons ions and molecules in the presence
of a constant magnetic field possesses a dielectric constant which
is in the form of a tensor  exact solutions of boundary value problems
involving such media are obtained for two dimensional configurations
explicit results are given for the reflection coefficients of stratified
plasma in planar and cylindrical geometry
   /
10523
radiation in a plasma part cherenkov effect  a linear continuum theory
in which the em and electroacoustic waves set up in a plasma by arbitrary change
and current sources are found from maxwells equations
the results are similar to those of pines and bohm or although the
latter start from the particle viewpoint
   /
10524
contribution to the theory of mode conversion  maxwells equations
are formulated for three dimensional riemann space  the propagation
of a lecher wave without mode conversion is considered
   /
10525
diffraction of a plane electromagnetic wave at a circular ferrite
cylinder  german version of paper published in
   /
10526
scattering of electromagnetic waves from concentric infinite cylinders
the solution for the scattering of radiant energy in the form of
electromagnetic waves by concentric isotropic infinitely long circular
cylinders is given for the incident energy travelling perpendicular
to the cylinder axis
   /
10527
theory of resonance absorption of energy by a rotating solid
   /
10528
use of a different type of fluorescent material as an optical maser
a device is suggested which is based on the stokes shift associated
with absorption and emission bands created by point defects in solids
such as kcl  preliminary calculations indicate that such a device
can be made to operate
   /
10529
generation of optical harmonics  analysis s is given together with
a description of experimental observation of the second harmonic
produced by projecting an intense beam of light through crystalline
quartz
   /
10530
stimulated optical emission in fluorescent solids part theoretical
considerations
   /
10531
stimulated optical emission in fluorescent solids part spectroscopy
and stimulated emission in ruby
   /
10532
fluorescence and optical maser effects in
   /
10533
electron trajectories in a nonuniform axially symmetric magnetic field
the equations for motions for electrons in a sinusoidally varying
magnetic field have been solved  a device for converging a hollow
cylindrical electron beam designed and built on the basis of the
solutions gave measured area convergences of to
   /
10534
energy bands in the presence of an external force field anomalous
velocities  the theory of field modified energy bands is extended
to include the effect of weak scattering forces  the modified current
operator is found to contain terms giving anomalous currents  the
theory of these currents is developed and their relation to the spontaneous
hall effect in ferromagnets is considered
   /
10535
spectrum of galactic radio emission  a discrepancy between theoretical
and experimental values of the radio spectral index is discussed
new observations at are consistent with the value previously obtained
   /
10536
radio star scintillations and the auroral zone  scintillations at
over a year period are analysed  the dependence on the altitude of
the source was much stronger in than in  the scintillations probably
arise in regions of the atmosphere which migrate southwards when
solar activity is high
   /
10537
radio spectrum of jupiter  review of the results of radio observations
from to the present
   /
10538
the solar noise burst of november  a description of the noise received
at and
   /
10539
spectral characteristics of type solar radio bursts  an explanation
of the appearance of radiation only at fundamental and second harmonic
frequencies and the frequent splitting observed in these lines is
given
   /
10540
decimetre radio bursts concurrent with solar type radiation  measurements
taken during a type burst show that radiation at can originate
in a part of the suns atmosphere widely different from the source
of radiation
   /
10541
coincidence of the explosive phase of solar flares with solar noise
bursts  comparison of commencement times of solar noise bursts with
those of the observed explosive phase of solar flares shows good
correlation
   /
10542
amplitude and angular scintillations of the radio source cygnus a
observed at boulder colorado  comparison with records from a suitably
placed ionosonde shows correlation between scintillations and spread
f but no  with e  the angular dependence of scintillations shows
that the ionospheric during the day slow irregular variations of
angle occur and are attributed to large scale lens like irregularities
   /
10543
intensity variations in outer van allen radiation belt  count rates
observed with explorer during stormy periods october december indicate
a decrease outside earth radii during the main phases  the lower
cut off values on the counters are for protons for electrons  the
proportion of soft radiation increases during periods of increased
intensity
   /
10544
some effects of diamagnetic ring currents on van allen radiation
a qualitative theoretical model is proposed to explain the depletion
of the outer van allen belt during the main phase of a storm  the
theory incorporates a magnetic tail on the dark side of earth a ring
current centred at earth radii and local betatron acceleration and
deceleration of van allen and solar pz particles
   /
10545
energy spectrum and angular distributions of electrons trapped in
the geomagnetic field  count rates taken during a sounding rocket
flight to km are used to derive distributions of pitch angles at
various heights and the energy spectrum the latter was found to be
constant above km  electron flux for energies at apogee was sec
   /
10546
the observed outer belt electron distribution and the neutron decay
hypothesis  the electron flux distribution along a line of force
of range in the equatorial plane is compared with a curve based on
the neutron albedo theory of electron production  there is sufficient
disparity between the two curves to suggest that other sources of
electrons must exist
   /
10547
unusual increase in the cosmic ray intensity on november  observations
at arctic and antarctic stations show a statistically significant
anisotropy
   /
10548
radar scattering cross section applied to moon return
   /
10549
the latitude dependence of radar meteor shower observations  a simplified
method of assessing the relative significance of meteor showers
is described which leads to good agreement between surveys in both
hemispheres
   /
10550
head echoes from meteor trails  head echoes are often reflected from
regions up to in length which may persist for many seconds after
the passage of the meteor  the consequences of this fact are discussed
   /
10551
solar x rays  measurements of the intensity of solar x rays made
during the past eleven years using rockets are reviewed and a useful
table showing intensities as a function of wavelength and solar activity
is given
   /
10552
preliminary data on solar extreme ultraviolet radiation in the upper
atmosphere  a rocket borne monochromator was flown in august the
intensity of the solar spectrum from was scanned in sec at a series
of heights up to km  tables of the intensities extrapolated to a
height above the earths atmosphere are given together with absorption
cross sections and t other useful information  for completeness similar
tables are given for wavelengths outside the range covered by the
august measurements
   /
10553
secular variations of short lived sunspots
   /
10554
geomagnetism in relation to aeronomy  a brief review dealing with
quiet day and storm variations and associated current systems the
motion of particles trapped in the radiation belts and phenomena
in the outer atmosphere
   /
10555
geomagnetic variations between november and november
   /
10556
on the reflection and refraction of hydromagnetic waves in ionized
gas  reflection and refraction of hydromagnetic waves at a plane
boundary between two semi infinite homogeneous media of anisotropic
electrical conductivity are considered for the case of a steady uniform
magnetic field perpendicular to the plane  difficulties in obtaining
solutions when the field is at other angles are demonstrated
   /
10557
electric currents associated with geomagnetic disturbances in the
auroral zone  currents of the order of have been observed at lerwick
during bay type disturbances  a west to east maximum occurred between
and zero current at and an east to west peak was measured at about
midnight  the west to east current was at the level of the f layer
and the east to west current near e layer level
   /
10558
the diurnal variation of k indices of geomagnetic activity on disturbed
days in
   /
10559
analysis of satellite data  from an analysis of the orbit of satellite
atmospheric density variations have been isolated which are tentatively
ascribed to third harmonic tides
   /
10560
errors in orbital predictions for artificial satellites of earth
   /
10561
atmospheric densities at heights of km  atmospheric densities determined
from changes in the orbits of earth satellites are discussed
   /
10562
determination of atmospheric densities from satellite observations
a discussion of the errors arising from various factors involved
in the determination of upper atmosphere densities from satellite
drag measurements
   /
10563
proceedings of the fourth afbmd stl symposium advances in ballistic
missile and space technology  the text is given of papers on various
aspects of rocket and satelli  e techniques including instrumentation
space guidance and computers  for papers on space communications
   /
10564
proposed satellite techniques for performing a high resolution survey
of the radio sky at medium wavelengths  the reception pattern of
a short dipole above the f layer is modified by refraction in the
ionized medium  the properties of this pattern are discussed and
satellite experiments using this phenomenon are suggested
   /
10565
satellite borne instrumentation for observing flux of heavy primary
cosmic radiation
   /
10566
cosmic ray measurements in the uk scout satellite  the main purpose
is to measure accurately the primary cosmic ray energy spectrum and
the changes in it due to modulation by the interplanetary magnetic
field  gm counters and a cherenkov counter will be used
   /
10567
radiation and other environmental effects on satellites  transistor
failure in a satellite spending an appreciable part of its life in
the inner van allen belt seems likely after several years  solar
cells cannot be effectively protected from hard radiation
   /
10568
lyman radia  ion  the role of lyman in the ionization of the d region
is discussed  nocturnal observations of lyman which lead to the concept
of the hydrogen geocorona are reviewed
   /
10569
theory of electrostatic fields in the ionosphere at equatorial latitudes
an analysis is made of the elongated es fields required to provide
the the e and f layer coupling in the dynamo theory for equatorial
conditions  the attenuation of the es field is found to be large
implying very small coupling for fields with horizontal wavelengths
of a few km most of this attenuation occurs at heights near the e
region  for an analysis in non equatorial regions see of october
   /
10570
apparent reflection heights and reflection properties of the ionosphere
above tsumeb south west africa determined by means of pulses in the
frequency band from to  the results of nighttime ionospheric measurements
made during the period august march are analysed to determine
the electron density distribution below the f layer  at least three
ledges in the electron distribution were regularly observed at heights
between and and in the lower e region  the occurrence of e layers
was also noted
   /
10571
comparison of absorption coefficients of the ionosphere from pulse
amplitude measurements and field strength recordings  ionospheric
absorption was measured by two methods vertical incidence soundings
at field strength measurements over an oblique incidence path in
length at mcs  threse frequencies are such that in both methods the
heights of reflection are equal  the absorption coefficients determined
using the two methods have a correlation coefficient of for both
daily and monthly mean values and are related to ez each other by
the square of the effective frequency
   /
10572
the ionospheric disturbance of november and  changes in ionospheric
absorption as shown by are discussed
   /
10573
nocturnal and seasonal variations of equatorial spread f  a classification
of spread echo patterns based on the distribution of relative
amplitude within the echo is described  the variations in spread
f index at waltair geomag are compared with those at kodaikanal
   /
10574
measurement of ionospheric drift by radio star observations  the
incidence of scintillations is greatest in the hours before sunrise
at puerto rico it is not correlated with spread f or e  the drift
results show that the ionosphere irregularities causing scintillation
are elongated along the lines of force of the geomagnetic field and
that drift rather than random changes is the main source of scintillation
   /
10575
a method of estimating ionospheric absorption heights from recovery
times  rapid recovery from absorption occurs when the ionizing source
is suddenly cut off  from a plot of ionospheric relaxation time
against height an estimate can be made of the height of the absorbing
layer which is in good agreement with measurements made by the three
frequency riometer method
   /
10576
ionospheric absorption on november  the results obtained using riometers
in canada are described
   /
10577
ionospheric absorption and solar activity in intermediate latitudes
measurements of the absorption of cosmic noise were made at athens
on and  analysis of the data allowed the components of the total
absorption due to the f and d layers and the extra component to be
estimated
   /
10578
ionospheric current systems of ten igy solar flare effects  the current
systems consist of two vortices one on each side of the magnetic
equator  the m northern vortex is centred west of the southern one
and is more intense in local summer than the southern one  the asymmetry
in the vortices can be described in terms of an ionospheric current
system
   /
10579
ionospheric critical frequencies and magnetic parameters of the day
before  the correlation between and at capetown and local magnetic
activity was calculated  the correlation is greatest when the magnetic
indices for the previous day are used  this is true both when and
means of are used in the correlations
   /
10580
connexion between micropulsations and the ionosphere  measurements
made at christchurch england and ascension island distant show that
pulses occur simultaneously at both stations but the same coherence
s not observed for pulsations
   /
10581
atmospheric ion compositions measured above wallops island virginia
preliminary data for heights between and obtained from two rocket
flights are given and compared with results of previous determinations
   /
10582
ionospheric information deduced from the doppler shifts of harmonic
frequencies from earth satellites  measurements made near the end
of the life of sputnik have indicated the presence of appreciable
ionization at a height of in the daytime and have revealed the existence
of ionospheric irregularities below
   /
10583
height of nighttime f layer irregularities at the equator  satellite
transmissions propagated through the irregularities produce a diffraction
pattern from whose velocity the effective height of the diffracting
screen may be determined  irregularities are elongated with axial
ratio at least along the earths magnetic field and lie between and
above the base of the f layer
   /
10584
the determination of the absorption of the ionosphere from pulse
amplitude observations  equipment for measuring ionospheric absorption
by means of vertical incidence soundings is described  it operates
at or with pulse width variable between and  details are given of
the polarimeter receiving circuit  see also above
   /
10585
on the validity of some approximations to the appleton hartree formula
   /
10586
investigation of ionospheric absorption on at waltair
   /
10587
the fading of radio waves reflected vertically from the ionosphere
during magnetic storms  correlation analysis is applied to the spread
rapidly fading reflection observed at cambridge during magnetic storms
the drift velocity is usually large and towards the west and the
direction of elongation of the diffraction pattern shows that the
ionospheric irregularities are aligned with the earths magnetic field
   /
10588
the electrically short antenna as a probe for measuring free electron
densities and collision frequencies in an ionized region  the in
integral equation method is used to obtain expressions for the admittance
of an electrically short centre driven dipole or base driven monopole
when immersed in a conducting dielectric  the conductivity and permittivity
of the medium can be calculated from measurements of the admittance
of the aerial immersed in the medium and in air
   /
10589
an analogue solution of the continuity equation of the ionospheric
f region  an electromechanical analogue computer is used to solve
an idealized f layer continuity equation  the results show how the
layer above the f peak is mainly controlled by vertical diffusion
of ionization and below the peak by the production and loss processes
the machine can also simulate the effect of a solar eclipse
   /
10590
effects of corpuscular emissions on the polar ionosphere following
solar flares  during the events of july and september ionospheric
absorption was more intense in the sunlit portion of the polar cap
after the september event there was strong auroral absorption a geomagnetic
storm and a decrease in f layer ionization none of these occurred
after the july event
   /
10591
ionospheric reflections below kilometres during polar cap absorption
events  vertical incidence observations on at scott base lati  ude
showed particle reflections from heights below during two polar cap
absorption events  the results are correlated with measurements made
in space vehicles during the same periods
   /
10592
electron densities in the outer ionosphere deduced from nose whistlers
   /
10593
some comments on obtaining electron densities in the exosphere using
nose whistlers
   /
10594
variations of emission in the upper atmosphere  a review of experimental
data with consideration of excitation mechanisms and relations with
other airglow emissions
   /
10595
a simultaneous study of the and emissions of the night airglow at
poona  results of measurements made in early
   /
10596
hydrogen emissions during the period november
   /
10597
power density requirements for airglow excitation by gyro waves
an array of dipoles radiating a gyro wave with a mean power of would
produce an easily observable enhancement of the nocturnal airglow
overhead within a solid angle of square degrees
   /
10598
temperatures deduced from aurora and airglow spectra  several experimental
results are combined to give a temperature profile between and
km
   /
10599
observations of auroral ionization during the period november  auroral
luminosity and radar echo amplitude at and were observed
   /
10600
three frequency measurements of auroral absorption  the ratio of
the measured absorption of cosmic noise during auroral events was
measured on two pairs of frequencies near  assuming that the electron
collision frequency as a function of height is known the height at
which the absorption occurs can be estimated heights of were usual
for intense auroral events but lower heights were observed for cosmic
ray events
   /
10601
auroral observations by radar in terre adelie  observations made
during the southern summer show a correlation between the geomagnetic
latitude of the echoes and the k value  for full report
   /
10602
auroral radar observations at during the period of the november solar
event
   /
10603
extension of nose whistler analysis  a method of analysis is described
which gives the nose frequency and the time delay to the nose when
the nose is not directly observable
   /
10604
servo system design for balloon borne star trackers  the telescope
pointing equipment can operate over a dynamic light range of the
average pointing error being within seconds of arc
   /
10605
magneto optical readout of magnetic recordings  this technique is
based on the rotation of the plane of polarization of a light beam
reflected from a magnetized surface
   /
10606
power supplies for space vehicles  available unconventional power
sources are reviewed in the light of possible future requirements
   /
10607
silicon power rectifiers  the processes involved in preparing single
crystal si are outlined and details of design production techniques
and characteristics of si rectifiers are given
   /
10608
theory of majority decision elements  various problems concerning
a single majority decision element are considered
   /
10609
majority decision functions of six variables  see also
   /
10610
a fourier transform generator parts
   /
10611
the address system and increment store for a digital differential
analyser
   /
10612
digitizer to tape punch coupling unit  the output in twelve binary
digits of a digitizer is briefly stored before operating a high speed
five track tape punch
   /
10613
study of the application of the hall effect in the construction of
logic circuit elements
   /
10614
the use of thin films for computer storage
   /
10615
diode steering increases speed of magnetic memories  by using the
recovery time of junction diodes for half selection of the same word
during the second half of a read or store operation a cycle time
is achieved in a magnetic storage system with word capacity
   /
10616
design of logic circuits using thin films and tunnel diodes  switching
circuits which have operated successfully are described and designs
suitable for a wide range of logic functions are suggested
   /
10617
resistance as dissipation into many reactive circuits landau damping
and nyquists noise theorem  nonradiative dissipation is not a loss
of energy but its dispersal into a large number of degrees of freedom
resistance can be simulated by purely reactive elements  this lead
to an understanding of landau damping and nyquists noise theorem
   /
10618
techniques of microminiaturizatio  the techniques of evaporated film
and semiconductor solid state circuit design are described and their
merits discussed
   /
10619
metal transfluxors  the choice of materials for and the design of
a three aperture transfluxor of are considered
   /
10620
transient response of grounded emitter switching circuits  analysis
of the effects of collector capacitance and load resistance  a ramp
input voltage is assumed which is close to the practical case than
a step function
   /
10621
the representation of branched circuits on an analogue computer
extension of earlier work of to cover another class of branched network
   /
10622
the effect of driving electrode shape on the electrical properties
of piezoelectric crystals  formulae are derived for the electrical
admittance of a piezoelectric crystal in terms of its resonant frequencies
and static and dynamic capacitances  the results are applied
to the investigation of the effect of electrode shape on the resonance
spectrum and the capacitance ratio of the crystal
   /
10623
the expanded reactance series resonator erser  a description is given
of a circuit element wherein the bandwidth between the infinities
of a series resonant circuit can be exchanged for increased steepness
of the reactance slope through resonance
   /
10624
time varying networks  an analysis is presented of some significant
developments in the last decade in the theory of time varying networks
   /
10625
nonsymmetrical properties of non linear elements in low and high
impedance circuits
   /
10626
on cyrator networks  the attenuation and image impedance characteristics
of four terminal networks using nonreciprocal elements are considered
in networks incorporating gyrators it is possible to obtain finite
attenuation in one direction and infinite attenuation in the other
   /
10627
nonrealizability of the complex transformer  a proof is given to
show that for a particular case the complex transformer cannot be
realized
   /
10628
high frequency broad band impedance matching  the design initial
adjustments and performance of a confluent band pass filter are discussed
and specific examples covering frequency ranges of and are given
   /
10629
an adaptive communications filter  a filter is described which is
optimum for a completely random communication signal
   /
10630
generating random noise with radioactive sources  the system comprises
a radio active isotope mixed with a light emitting phosphor and a
type photomultiplier tube  it was designed for application with a
repetitive analogue computer and provides both a random telegraph
wave with a mean count rate of and gaussian noise with a power spectrum
   /
10631
the generation of variable square pulses in the nanosecond range
a generator is described which is capable of producing pulses of
duration variable between and with pulse rise and decay between and
of pulse height within  correction
   /
10632
pulse analysis  the mathematical apsects of the determination of
the response of systems by pulse techniques is discussed with particular
reference to many of the practical problems involved in applying
the techniques
   /
10633
radar boxcar circuits suing nuvistors transistors and zeners  two
versions of a waveform sampling device with zener diode biasing are
described which give a signal noise ratio at room temperature
   /
10634
amplifiers with band filter coupling  the design of multistage amplifiers
with flat or tchebycheff type response is considered design formulae
and response cuf curves are given
   /
10635
transistor amplifier stages with prescribed gain and sensitivity
a design procedure is developed for circuits meeting prescribed gain
and sensitivity criteria in terms of anticipated operational variations
and available component data
   /
10636
an engineering approach to the design of transistor feedback amplifiers
a technique is developed for amplifier design which produces very
accurate expressions for the transmittance without requiring any
quantitative information about the transistors
   /
10637
the dielectric harmonic amplifier a controllable harmonic generator
circuits incorporating ferroelectric capacitors for producing harmonics
of power frequencies are described  applications as amplifiers or
controllable frequency changers are mentioned
   /
10638
lossy coupling in parametric amplifier  a method of analysing a two
resonant circuit parametric amplifier with a lossy coupling branch
   /
10639
experiments with nonreciprocal parametric devices  a report is given
of the behaviour of two nonreciprocal parametric devices  one device
is a unilateral amplifier and the other is a circulator
   /
10640
the helix parametric amplifier a broad band solid state microwave
amplifier  the amplifier uses a helix as a slow wave distributed
interaction structure and has variable capacitance solid state diodes
distributively coupled to the helix  gains above have been obtained
in the region
   /
10641
generalized coupled mode theory
   /
10642
phase inverters utilizing controlled superconductors  two arrangements
for phase inversion in a controlled superconductor push pull amplifier
are illustrated
   /
10643
transient response of fm signals  practical investigation of distortion
introduced by networks and lines into a signal when its frequency
suddenly changes  the effects of filters coaxial terminations and
resistive and rc networks are considered
   /
10644
linear frequency discriminator  a method of distortionless demodulation
of lf fm signals with large deviations is described  circuit design
and performance are discussed and analysed to determine conditions
for maximum linearity
   /
10645
electrical conduction phenomena in anisotropic media  part strongly
convergent solutions of linear operational equations particularly
of blochs integral equations
   /
10646
a note on the relativistic boltzmann equation and some applications
the relativistic equation in the absence of collisions is derived
and applied to the case of a velocity modulated drifting electron
beam
   /
10647
electron trigonometry a new tool for electron optical design  a method
is developed for predicting the image formation in electron optical
systems as a substitute for trajectory tracing  it is based on approximating
axial potential distributions by linear or parabolic segments
linear sections are replaced by equivalent drift tubes of appropriately
scaled length parabolic sections observe certain triangle rules for
the sum of three phase angles of flight  applications of the method
in the design of magnetic and combined lens systems are illustrated
   /
10648
the theory of secondary electron emission of metals part of
   /
10649
average kinetic energy of diffusing particles in discharge and electron
tubes  for particles flowing under a concentration gradient or across
a region of a small field in the body of a gas the mean kinetic energy
of particles with a maxwellian velocity distribution is
   /
10650
the origin of plasma waves in strongly ionized gases  the development
of plane waves in a gas plasma without external fields is considered
   /
10651
plasma engineering part applications of plasma  uses of plasma are
considered in the fields of thermonuclear research thermonic and
magnetohydrodynamic power conversion propulsion and electronics
the generation and heating of plasma and measurement of its parameters
are described in parts of
   /
10652
cavity method for measurement of high electron densities in plasmas
conventional microwave cavity techniques may be used to measure electron
densities considerably above that corresponding to plasma resonance
at tht the particular microwave frequency employed
   /
10653
observations of ionic sound waves in plasmas  ionic sound waves were
produced in a spherical plasma  six different gases were used and
a relation between the lowest fundamental frequency and atomic mass
was found
   /
10654
new form of plasma dispersion formula usable for analogue computing
a correction term is derived which takes into account the influence
of a magnetic field
   /
10655
representation of propagation parameters for the plasma in a magnetic
field  the effect of a dc magnetic field on the properties of a uniform
plasma for the propagation of em waves is described using three dimensional
models  see also of
   /
10656
study of electromagnetic wave polarization in magneto plasmas by
a matrix method of crystal optics  a method o is given of studying
em wave propagation through magneto plasmas which is appropriate
to microwaves
   /
10657
alfven waves in partially ionized gases  the conditions for formation
of an alfven wave are determined and fundamental equations are derived
to describe the electrodynamic behaviour of the ionized gas
   /
10658
electromagnetic surface waves on a plane interface  surface waves
are defined as waves exponentially decreasing on both sides of a
plane interface  the relations between the propagation parameters
and the material constants are derived in a general case which includes
media with different magnetic permeabilities
   /
10659
fundamental solution of the vectorial wave equation in spherical
coordinates  two families of vectors are determined which under certain
conditions together form an orthonormalized system tied to the geometry
of a sphere
   /
10660
vertex generated waves outside metallic wedges  the waves generated
by a magnetic line source placed at the vertex of a wedge of high
conductivity and arbitrary angle are studied  the effect of a dielectric
coating on the wedge is examined and the propagation of surface waves
considered briefly
   /
10661
the low frequency scattering by a perfectly conducting strip  previous
approximate solutions have not been satisfactory as no expansion
parameter suitable for all terms has been found  results of an analysis
suitable for thin cylinders and arbitrary angles of incidence are
given
   /
10662
induced and spontaneous emission in a coherent field  previous theoretical
work on the interaction of molecules and em fields in a resonant
cavity is extended to take account of large perturbations
   /
10663
splitting of electron spin resonance lines by an applied electric
field
   /
10664
linear effect of applied electric field in electron spin resonance
   /
10665
second order effect of spin orbit interaction on the paramagnetic
resonance spectra of ions with a single electron
   /
10666
some operating characteristics of flash pumped ruby lasers
   /
10667
repetitive hair trigger mode of optical maser operation
   /
10668
charged particle trajectories in static electric and magnetic fields
relative expressions are derived for the curvature and torsion of
a trajectory in terms of electric and magnetic field distributions
   /
10669
an examination of the steady state model in the the light of some
recent observations of radio sources  the unsatisfactory nature of
the theoretical model is demonstrated by a comparison of predictions
with observational results
   /
10670
an investigation of the clustering of radio stars  an examination
of two recent surveys produced no evidence of clustering and an upper
limit of could be set to the percentage of sources which occur in
clusters
   /
10671
the number flux density relation for radio sources away from the
galactic plane  observations at have been used to derive the number
flux density relation for sources situated at galactic latitudes
   /
10672
radio astronomy from space vehicles  the usefulness of a radio receiving
system in space is considered  satellite experiments at frequencies
outside the range are suggested
   /
10673
counts of extragalactic radio sources a formula is derived for the
cumulative totals of class radio sources and compared with observational
measurements
   /
10674
some attempts to detect linear polarization of galactic radio emission
from the spur at  evidence from measurements at suggests that the
theory of does not adequately explain the spur shaped feature of
radio emission
   /
10675
slow drift solar radio bursts  harmonic frequency ratios solar longitude
dependence and frequency drift rates
   /
10676
latitude dependence of a forbush type decrease
   /
10677
radiation measurements in the slot between the van allen belts to
an altitude of kilometres
   /
10678
longitudinal dependence of radiation belt scattering and primary
auroral particles
   /
10679
world wide distribution of diurnal variation of the neutron intensity
of cosmic rays  data from stations throughout the world for the period
to december have bee analysed to detect possible latitude and i diurnal
effects in periods averaged over six months
   /
10680
drift rate in a dipole field  expressions are found for drift rate
and period and the results are applied to the drift of trapped electrons
and protons in the geomagnetic field
   /
10681
the distribution of trapped particles in a changing magnetic field
the changes in distribution which result from various changes in
the field parameters are calculated
   /
10682
dynamics and structure of the outer radiation belt  an analysis of
electron measurements made in explorer is presented in terms of four
time independent parameters of the outer van allen belt  the belt
has two peaks of intensity e max amd e max during a storm coincides
with dipole lines of force  max is used as a tracer to follow changes
in the magnetic field  some changes are accounted for only by invoking
an irreversible energy gain or loss in the belt  the peaks are observed
to move radially inward during a storm and peak electron intensities
fall by about
   /
10683
radar contact with venus  in the ussr in april a transmitter and
receiver operating at about were used in conjunction with an analysing
and integrating system which enabled both the range of the planet
and doppler spread of received signals to be determined
   /
10684
radar measurements of the planet venus  by means of radar equipment
operating at a new value for the astronomical unit was determined
accurate to and the rotation period of venus was estimated as days
   /
10685
amplitude distribution for radio signals reflected by meteor trails
part  vhf signals are propagated to distances of by reflection from
meteor trails  a probability distribution for the envelope of the
received signal is derived for the case of reflections from numerous
small meteors coincident with residual signals from infrequent large
meteors
   /
10686
auroral effects on the earths electric field  abnormal conduction
currents at the earths surface are interpreted in terms of currents
generated in the atmosphere during three aurorae
   /
10687
interaction of west ford needles with earths magnetosphere  the influence
of drag forces on the west ford needles is studied and is shown
to be predominant at heights above
   /
10688
sun earth relations and associated periodicities  a periodic analysis
shows that magnetic impulses tend to recur at three day intervals
and that the interval between a flare and a magnetic impulse is about
days
   /
10689
some relationships between short wave fade outs magnetic crochets
and solar flares  statistical analysis indicates a strong association
between sudden sw fade outs and magnetic crochets  no significant
difference could be found in fade out type between those fade outs
associated with flars of importance greater than two and those with
flares of importance less than two
   /
10690
on the geomagnetic effect of the solar eclipse of february at genoa
in english
   /
10691
an idealized problem of plasma dynamics that bears on geomagnetic
storm theory  an idealized problem is solved a cylindrical sheet
of neutral ionized gas is projected into a magnetic field which is
aligned along the cylinder axis and varies as where is the distance
from the axis  for a magnetic field comparable in magnitude with
that of the earth the sheet would be stopped at earth radii for storm
and at earth radii for storm
   /
10692
interpenetration of two ionized gas clouds  counter streaming resulting
from the collision of two ionized gas clouds is unstable  the double
stream forms small clouds of space charge which may be the cause
of geomagnetic storms and the radio noise of colliding galaxies
   /
10693
rocket measurements of the magnetic field above new mexico  absolute
total intensity was measured in a rocket at heights up to and compared
with the intensity predicted by spherical harmonic coefficients
   /
10694
measuring the doppler frequency shift on satellite transmissions
the use of a phase locked oscillator for observation of doppler shift
in transmissions in the range is described and the effect of signal
modulation on the accuracy of measurements is illustrated by examples
   /
10695
theory of an accurate intermediary orbit for satellite astronomy
   /
10696
on the long period lunar and solar effects on the motion of an artificial
satellite  part  the theory of lunisolar effects on artificial
satellite orbits is presented in a form suitable for numerical integration
and for the development of the perturbations into fourier series
with numerical coefficients
   /
10697
a comparison of theory and observation of the echo satellite  a comparison
is made between theoretical and observed changes in the perigee
height of echo due to radiation pressure  the change in atmospheric
drag gives information on densities in the height region
   /
10698
infrared circuits in tiros satellites  a channel radiometer for measuring
parameters relating to the earths heat balance and horizon sensors
to determine spin rate and orientation are described
   /
10699
determination of the earths gravitational potential from satellite
orbits  from the motions of the orbital planes of four satellites
values for the second fourth and sixth harmonics in the earths gravitational
potentials have been obtained  allowance is made for atmospheric
lunar and solar perturbations and the results are compared with those
of other authors
   /
10700
radioactivity produced in discoverer by november solar protons
   /
10701
latitude and diurnal variations of air densities from to as derived
from the orbits of discoverer satellites  an analysis of orbital
information obtained from nine discoverer satellites shows that variations
in air density between day and night in the region  curves of
daytime density plotted against height indicate the possibility of
a region of local heating at which disappears at night
   /
10702
courier communication satellite
   /
10703
chemical heating above the polar mesopause in winter
   /
10704
the electron content of the ionosphere in winter observations of
the faraday rotation of moon reflected radio waves at two closely
spaced frequencies are described  accurate values were obtained for
the total electron content of the ionosphere for many hours on successive
days
   /
10705
the total electron content through the entire ionosphere by the faraday
rotation technique  a linear relation between total electron density
anc and is demonstrated which presents a possible method of determining
variations in intensity of solar ionizing radiation
   /
10706
the conductive chapman layer  the shape of the electron production
function when ionizing radiation acts as an atmospheric heat source
is given for atmospheres in mixed or diffusive equilibrium
   /
10707
studies of the new ionospheric model  the original model is perfected
on the basis of profiles and results obtained from moon echo and
radar scatter observations
   /
10708
wind systems in the mesosphere and lower ionosphere
   /
10709
study of horizontal drifts in the e region of waltair  results obtained
over a period including the steady hr and hr components found by
harmonic analysis are presented  other drift results an the e region
drifts deduced from variations are quoted for comparison
   /
10710
height gradient of horizontal drifts in the e region over waltair
a value of is obtained between and  see also
   /
10711
evidence of some geomagnetic control on the layer  the bifurcation
of the noon f layer is found to be related to geomagnetic latitude
   /
10712
analysis of the transition region  from a detailed study of profiles
the atmospheric scale height and the relative values of production
rates and loss coefficients are deduced
   /
10713
effect of electron ion collisions in the f region of the ionosphere
on the absorption of cosmic radio noise at ahmedabad  changes in
absorption associated with magnetic storms  riometer measurements
at a frequency of have been compared with calculated values of total
nondeviative absorption due to collisions with neutral particles
with ions which occurred below maximum and the differences ascribed
to absorption occurring baove the layer maximum  the results show
a depletion of electrons above the f maximum on the day following
a sudden commencement and are compared with satellite observations
on particle fluxes in van allen belts during storms
   /
10714
riometer observations during a solar eclipse  an average decrease
of ia the absorption of cosmic noise transmitted via the d region
was observed during the total eclipse of october
   /
10715
solar flares and association with the lower ionosphere  short wave
fade outs and are adopted as ionospheric parameters  the statistical
relations between these and solar flares and solar rf emission are
studied  the analysis includes flares from class down to class  the
number of fade outs is correlated with flare activity and with radio
noise increases
   /
10716
a model of solar flare induced ionization in the d region  the energy
distribution of the x radiation in the range was estimated from rocket
measurements during a class flare on august  simultaneous measurements
of cosmic noise at showed the changes in d layer absorption during
the flare  the absorption can be accounted for by assuming a recombination
coefficient of about and an electron density profile which varies
linearly from at
   /
10717
possible solar flare effects in the f region of the ionosphere  sudden
changes in are suggested as being due to the effects of travelling
disturbances in the layer and not to solar flares of in reply the
authors point out that on november a sudden change in occurred simultaneously
at stations apart which invalidates munros hypothesis  also
a change in occurs only when the height of the peak of the layer
at the time of the flare is less than km
   /
10718
rocket measurement of a daytime electron density profile up to  results
are compatible with ground based and satellite derived measurements
   /
10719
first pulsed radio soundings of the topside of the ionosphere  preliminary
report on a rocket test of the fixed frequency system to be used
in a satellite  while the rocket was above the f layer pulse echoes
were observed at and from the ordinary ray and extraordinary ray
reflection levels below  unexpected phenomena were spread and field
guided echoes near the and reflection levels and local spread echoes
at
   /
10720
an annual and a semiannual variation of the upper air density  fluctuations
in the acceleration of several satellites are analysed  see
also
   /
10721
satellites and the earths outer atmosphere  the structure of the
atmosphere as determined by recent experiments is discussed
   /
10722
world maps of during the igy  maps showing contours of are reproduced
for each month of the year and are based on measurements made during
the igy when solar activity was very high  constant local time maps
are given for and those for a given universal time refer to the hours
   /
10723
transresonant electron acceleration  describes a mechanism additional
to that of helliwell for the acceleration of van allen electrons
by whistlers  non relativistic electrons would be accelerated by
whistlers of about field strength  the mechanism depends on the whistler
frequency doppler shifted by the electron velocity passing through
the electron gyro frequency
   /
10724
diurnal variation of high latitude auroral frequency on magnetically
quiet and disturbed days  the frequency of occurrence as a function
of time of day is plotted separately for three sectors north and
south of the senity and centred on the zenity  quiet and disturbed
days are considered separately  the frequency distributions differ
from each other and can be interpreted in terms of the movement of
the auroral zone relative to the station at nord greenland
   /
10725
energy spectrum of atmospherics and attenuation of different low
frequencies with distance  supplement energy spectrum curves of atmospherics
produced at known distances are derived from simultaneous measurements
on four frequencies in the range of  curves of attenuation
for the range are similar to the theoretical curves of budden
   /
10726
a note on whistlers observed above the ionosphere  whistlers were
observed between september and december in satellite vanguard between
heights of and of these occurred between and indicating low ionospheric
absorption at night
   /
10727
terrestrial extremely low frequency noise spectrum in the presence
of exponential ionospheric conductivity profiles  expressions are derived
which are derived which are applicable to a nonhomogeneous ionosphere
the exponential model gives slightly lower resonant frequencies and
less damping of the resonant peaks than a sharply bounded model of
agreement with measurement is improved
   /
10728
a study of ionospherics at macquarie island  a systematic study of
radio emissions of natural origin recorded at one station is presented
and the generation of these ionospherics is considered on the basis
of an extension of the cherenkov radiation model
   /
10729
stanford pacific naval laboratory conjugate point experiment  good
correlation was found in the times of occurrence of em phenomena
observed at high latitude conjugate locations
   /
10730
a nonlinear integral equation from the theory of servomechanism
   /
10731
improved high power dc converters  design and performance details
of several new circuits are given
   /
10732
cathode coupled cascode stabilizer circuits  comment on of and authors
reply
   /
10733
methods and possibilities for automatic character recognition  review
of methods with references
   /
10734
selection of analogue variables by means of idealized diodes  diodes
the circuits proposed for the selection of maxima and minima in analogue
computer applications introduce only very small errors near the points
of discontinuity of the functions
   /
10735
ferrite cores as logical elements  properties are discussed and the
operation of a typical circuit is analysed
   /
10736
persistent current memory circuit  difficulties predicted by crittenden
et al  with regard to the use of in persistor switch elements are
disproved by results obtained with persistatron elements made of
thin films
   /
10737
high speed memory uses tunnel diode circuit  the unit operates at
and has a capacity
   /
10738
a transistor binary digital logic system  a system of digital logic
is described which uses as a basic unit a circuit consisting of two
transistors in a bistable arrangement with a novel method of obtaining
an output which indicates which of the two stable states the unit
is in
   /
10739
a proposal for uniform symbols of logical connections  a system of
symbols for representing logic functions id described and its application
illustrated by examples
   /
10740
electrical noise in carbon film potentiometers  noise characteristics
are studied as a function of parameters such as the speed of rotation
of the sliding contact and the load current
   /
10741
transfer characteristics of permalloy tape toroidal cores of small
tape thickness and with square hysteresis loop  analysis of core
characteristic allowing for the previous history of the core and for
inertia effects  the treatment is similar to that used by chen and
papoulis of and
   /
10742
q factor anomalies in series coupled ferrite rod inductances  an
examination of the variation of the q factor of a coil divided into
two series coupled parts positioned at different points on the core
results are discussed with reference to high q oscillatory circuits
and in particular the efficiency of ferrite rod aerials
   /
10743
the equivalence of one class of networks with magnetic branches and
one class of kirchhoff networks with magnetic elements  toroidal
core networks equivalent to transfluxors are derived
   /
10744
superconductor transition switching time measurements using a superconductive
radio frequency mixer
   /
10745
high speed silicon computer diodes as rf switches
   /
10746
transformer drive for switching transistors  a note on design problems
and the preferred circuit arrangement
   /
10747
the cryosistor a field effect controlled impact ionization switch
a new three terminal device is described in which the impact ionization
of impurities in ge at is controlled by means of the depletion field
effect of a reverse biased junction  the localized nature of the
ionization should permit the construction of numerous independent
cryosistors on a single ge wafer
   /
10748
signal flow graphs of a linear system  a method is proposed for the
construction of a signal flow graph based on a nonessential node
concept
   /
10749
linear signal flow graphs  introduction into the principles and use
of the topological method of signal flow graphs
   /
10750
spectral response of a nonlinear device  application of fourier series
expansion with a bessel function substitution
   /
10751
the cascading of symmetric quadripoles  the transformation into a
single bridge circuit of cascade connected bridge circuits proved
is applied to cascade connected unequal quaripoles
   /
10752
nonlinear investigation of a parallel integrator with the aid of
an approximation of first order algebra
   /
10753
stepped waveguide transformers and filters  a review of recent developments
in the synthesis of stepped quarter wave transformers and half
wave filters is given  a recent paper by holte and lambert of is
discussed
   /
10754
catalogue of power law and tchebycheff type filters from order  tables
are given extending the earlier catalogue of
   /
10755
optimum matching of symmetrical low pass and high pass filters  application
to low pass and high pass ladder filters using piezoelectric
crystals  appendices to earlier paper
   /
10756
low pass and high pass ladder filters using piezoelectric crystals
and designed by the image impedance method for single cut off frequency
filter structures  several design methods are suggested  see also
of
   /
10757
the tuning fork a two stage mechanical band filter  a tuning fork
coupled to electromechanical transducers is considered as a quadripole
with band pass properties
   /
10758
x band electronically variable attenuator  the attenuator described
comprises a pair of matched crystal diodes with variable external
bias mounted in a symmetric stripline structure
   /
10759
the switching on of a resonant circuit with controlled reactance
investigations of the build up transient characteristics of a variable
reactance oscillator parametron
   /
10760
one tunnel diode flip flop hf behaviour  the switching speed of the
circuit discussed in of is determined  the use of the circuit as
rf detector and high speed counter is suggested
   /
10761
boxcar integrator with long holding times  a detailed description
of the circuit with component values and performance data
   /
10762
microwave harmonic generation by ferrimagnetic crystals  a cavity
resonant at both and was used  the generation of second harmonics
was in good agreement with theory  a figure of merit for a ferrimagnet
is defined
   /
10763
some types of low noise amplifier  a discussion of the advantages
and disadvantages of vacuum tubes transistors masers parametric amplifiers
and tunnel diodes used in the construction of low noise amplifiers
for the frequency range  some experimental results are given and
frequency ranges suggested for the devices
   /
10764
the linearized transfer function of a phase locked loop containing
an if amplifier
   /
10765
the design of wide band power amplifiers for the steady state condition
   /
10766
vacuum tube networks
   /
10767
the stability of narrow band transistor amplifier stages  a stability
criterion is derived on which a method of phase neutralization is
based
   /
10768
comment on a theoretical comparison of average and spot noise figure
in transistor amplifiers  comment on
   /
10769
comments on design theory of optimum negative resistance amplifiers
comment on
   /
10770
thermodynamics and statistical mechanics of a three level maser
the analysis gives results which agree with those obtained by solving
the rate equations  explicit expressions are also obtained for the
internal energy heat capacity and entropy  the calculations are extended
to include spontaneous emission and cross relaxation as well as the
usual thermal relaxation
   /
10771
magnetization nutations in maser oscillation pulses  the maser equations
of are shown to give similar time dependent magnetization and magnetic
field patterns to kemps equations of for similar boundary conditions
and circuit parameters
   /
10772
characteristics of an ammonia beam maser  the design construction
and operating characteristics of a maser are described with particular
reference to the use of the line  threshold oscillation conditions
and tuning effects are calculated theoretically and compared with
observed performance
   /
10773
maser oscillation observed from maser at  the maser described in
of has been rebuilt and maser oscillation obtained at
   /
10774
a band parametric amplifier with large bandwidth  a bandwidth of
at was achieved using a single varactor diode
   /
10775
unidirectional lower sideband parametric amplifier without circulator
the amplifier described has the characteristics of a circulator system
in respect of matching gain noise figure and non reciprocity but
has inferior bandwidth
   /
10776
theory of parametric amplifiers and converter amplifiers of resistance
type  the investigations cover nonlinear reactance and tunnel diode
circuits with particular reference to down converters of the type
described by et al
   /
10777
an electronically tunable up converter  a lower sideband up converter
with a single varactor diode is described
   /
10778
the effect of large pump voltage on tunnel diode down converter performance
lower noise factor and increased stability can be achieved
through the application of relatively large pump voltages  the effects
are predictable by a theory incorporating a suitable power series
representation for the diode characteristic
   /
10779
the use of square wave carrier currents for supplying ring modulators
systematic tests show the advantage of square waves for modulator
carrier supply  the application of transistor circuits for generating
the square waves by frequency division and multiplication eliminates
unwanted frequencies without the use of filters
   /
10780
rectifier modulators  stray capacitances in modulators of nominally
purely resistive type always increase the conversion loss  sets of
experimental results and a normalization procedure are discussed
the circumstances in which it is desirable to tune out the stray
capacitances by means of inductances are assessed
   /
10781
nonlinear distortion in the amplitude demodulation of small alternating
voltages by means of thermionic and germanium diodes
   /
10782
hyperfine interaction due to orbital magnetic moment of electrons
with large g factors
   /
10783
microwave measurements on a high frequency excited gas discharge
waves were transmitted through the discharge vessel and amplitude
and phase changes were measured as a function of the anode voltage
of the plasma producing hf generator  horn radiators were applied
to the ends or sides of the vessel and the direction of polarization
was varied
   /
10784
reflection of an electron beam from high frequency fields  experimental
verification of time average forces due to an rf field acting on
charged particles is obtained by measuring the transmission of an
electron beam through the high frequency fields of a cavity  by adjusting
the external dc magnetic field so that cyclotron resonance is
approached it is possible to reflect high energy beams that is of
microwave power completely reflected a beam  agreement between experiment
and theory was close
   /
10785
anomalous electron double diffraction  description and discussion
of an effect observed in tandem foils of and
   /
10786
production of direct voltages in a rarefied gas tube excited by a
high frequency electric field  an investigation of the influence
of the coil position and hf excitation voltage on the direction of
current flow through the discharge tube
   /
10787
electron energy distributions in plasmas the cathode regions in helium
neon and argon  electron energy distributions in striated positive
columns of inert gas discharges have been measured and the effects
of impurities on these distributions and on the uniformity of the
column discussed
   /
10788
microwave study of non ionizing shock waves  the interaction of microwaves
with gaseous plasmas is used to study weak shock waves in low
pressure gases
   /
10789
on radiations from plasma in a static magnetic field  microwave radiometer
measurements at of extraordinary waves radiated at right angles
to the magnetic field show resonances in accordance with the theory
of gross
   /
10790
leakage in a steady state of a plasma with two temperatures confined
by a magnetostatic field  an extension of earlier work to the case
of unequal electron and ion temperatures
   /
10791
triple resonance phenomenon in plasmas  a triple resonance effect
may occur under certain conditions for a em e wave propagated in
an ionized plasma in the presence of a steady magnetic field  the
effect is demonstrated experimentally and the difficulties encountered
and techniques employed in the experiment are described
   /
10792
the absorptivity spectrum of a uniform anisotropic plasma slab  the
absorptivity spectrum of a plasma slab is computed for waves propagating
parallel and normal to an applied static magnetic field for various
electron densities electron collision frequencies and slab thicknesses
peaks in the absorptivity occur at frequencies near the edges of
the stop bands within which little energy can enter the plasma because
of reflection at the first boundary
   /
10793
oscillations in a plasma in a weak magnetic field  previous work
by kato is extended using discharge tubes with high emission cathodes
and vapour at lower pressure
   /
10794
plasma oscillations in external fields  for a weak electric field
the usual method of analysis valid for zero field can be applied
the formation of ion waves and their time variation are considered
   /
10795
thermionic emission from spherical metallic particles  the build
up of positive charge on a particle due to loss of electrons in the
absence of space charge is predicted quantitatively
   /
10796
localized magnetic states in metals  the conditions necessary for
the presence or absence of localized moments on solute atoms containing
inner shell electrons are analysed in terms of a simplified model
and stability conditions are discussed
   /
10797
vavilov cherenkov effect and bohr radiation produced by a beam of
charged particles in a dispersive medium  an extension of earlier
work with particular reference to instabilities and coupling effects
   /
10798
electron beam excitation of a fabry perot interferometer  energy
is extracted from a modulated electron beam by injecting the beam
diagonally t through dielectric between the plates of the interferometer
an output power of about at has been obtained
   /
10799
high frequency diffraction by a sphere  a procedure suitable for
investigating diffraction produced by a convex body with rotational
symmetry illuminated by a high frequency plane wave is discussed
and applied to the case of a sphere
   /
10800
on the theory of the diffraction of a plane wave by a large perfectly
conducting circular cylinder  the boundary value problem is treated
for the case of an incident harmonic plane em wave on a cylinder
of radius much greater than the wavelength  the method used is a
straight forward application of a fourier integral transform analysis
to a boundary value problem
   /
10801
diffraction of a plane wave by an almost circular cylinder  the two
dimensional problem of an incident e plane wave is treated  the method
of solution is based on infinite fourier transform techniques  an
analysis involving a watson transform is also given in an appendix
   /
10802
experiments on the diffraction of microwaves at plane lattices  investigations
were carried out at using a horn radiator and artificial
dielectric lens  the two dimensional lattices were formed by balls
circular disks or dipoles
   /
10803
scattering of microwaves from a cylindrical plasma in the born approximation
part  earlier work is extended to the case of a plasma scattering
the spherical waves radiating from an electric dipole
   /
10804
the absorption of electromagnetic waves in a wide frequency range
by a thin homogeneous layer with losses  the frequency bandwidth
of absorbers using a single homogeneous lossy layer is investigated
for conditions of vertical incidence  with a very thin layer it is
possible to achieve a frequency coverage over a range of
   /
10805
energy transfer within a spin system  experimental investigations
are described of the nature and efficiency of the transfer within
a nuclear spin system of energy absorbed from an external rf magnetic
field
   /
10806
magnetostatic modes of a ferromagnet slab  the characteristic modes
of a thin slab magnetized in its plane are obtained in the magnetostatic
limit
   /
10807
excitation of spin wave resonance by microwave phonons  in a thin
ferromagnetic film a series of standing spin waves can be excited
by phonons of the same frequency as the spin waves but at wavelengths
considerably larger than the magnon wavelength
   /
10808
lasers part devices and systems  an illustrated review of the operation
o of various types of laser device
   /
10809
the pulsed ruby maser as a light amplifier  using a ruby maser oscillator
as a light source a net gain of two was observed
   /
10810
power output characteristics of ruby laser  a theoretical treatment
giving values for the efficiency of operation
   /
10811
probabilities for the neon laser transitions
   /
10812
measurement of the relaxation time by modulation of the radio frequency
field and detection of the he variation of magnetization with the
controlling field  an extension of the method described by whitfield
and redfield of is proposed using a much higher modulating frequency
under these conditions variations in the signal induced in the pick
up coil may be used to determine  three methods of detecting the
signal are examined
   /
10813
corbino disk  predicted changes in magneto resistance in a flat annular
disk in a magnetic field are in rough agreement with experiment
   /
10814
on the theoretical limitation of a radio telescope in determining
the sky temperature distribution  theoretically sky coverage is not
intrinsically limited by the aerial power pattern provided that both
electrical and mechanical scans are used but there is a practical
limit due to noise and power pattern
   /
10815
radio telescope interferometer
   /
10816
the possibility of observing features of galactic radio emission
from a satellite borne radio telescope  the experimental conditions
for the required degree of focusing are discussed  the receiver should
sweep a frequency range of with a bandwidth of in a satellite established
in a nearly circular orbit at a height of
   /
10817
on the apparent long term negative correlation between scintillations
and spread f  a close examination of the experimental situation relating
to chivers observations shows that the result is not unexpected
   /
10818
interferometric studies of type solar bursts of continuum radiation
on and  type emission at occurs at a height less than while the source
has an angular diameter less than and no motion  at the height is
greater than the diameter is or greater and the source has a large
movement
   /
10819
the radio emission from normal galaxies a study of spirals at
   /
10820
preliminary observations of the polarization of radio sources on
a wavelength of  a consideration of measurements made with crossed
aerials on several radio sources shows that the radiation from virgo
a is probably due to synchrotron emission
   /
10821
standard errors at harmonic analysis on cosmic ray data
   /
10822
changes in the diurnal hour of maximum of the cosmic ray intensity
the evidence from ottawa churchill and resolute supports a year cycle
in the hour of maximum intensity at ottawa and perhaps churchill
while at resolute it follows k
   /
10823
time variation of cosmic ray intensity in the antarctic region  atmospheric
temperature effect  from the annual change in the amplitude
of the diurnal variation variations in isobar level are inferred
and compared with radiosonde data
   /
10824
time variation of cosmic ray intensity in the antarctic region part
unusual increase  differences in the characteristics of unusual increases
between north and south polar stations suggest the existence of
anisotropy in solar particles from deflection in solar magnetic clouds
   /
10825
variations of the cosmic radiation in november
   /
10826
balloon measurement of solar cosmic rays at fort churchill canada
during
   /
10827
the lifetime of radiation belt protons with energies between and
m  the charge exchange lifetime of protons in the val allen radiation
belts is calculated using experimentally measured cross sections
these values are compared with estimates of coulomb scattering lifetimes
   /
10828
predictions of cosmic ray storms from geomagnetic data  the need
for simultaneous high altitude soundings and ground observations
during cosmic ray storms is established  the times of the sudden
commencement of a geomagnetic storm and the forbush decrease of cosmic
ray intensity show insufficient correlation for accurate predictions
to be made
   /
10829
sweep frequency observations of meteor scatter bursts  the duration
of the signals as a function of frequency agrees closely with the
theoretical inverse square relation
   /
10830
ground conductivity determinations at low radio frequencies by an
analysis of the spheric signatures  of thunderstorms  the experimental
and analytical techniques are described  a detailed comparison of
predicted and experimentally observed waveforms indicates that the
effective conductivity can be determined to a precision of one or
two significant figures  application of the techniques for evaluating
the reflection and transmission properties of the lower ionosphere
is suggested
   /
10831
a provisional ground conductivity map for canada  the derivation
of the map is discussed results are given of propagation measurements
over the great lakes region to determine the conductivity of fresh
water areas
   /
10832
the effects of energetic trapped particles on magnetospheric motions
and ionospheric currents  distortions of stable belts of particles
in the earths magnetic field due for example to the interaction of
new groups of particles or to the compression of the earths fields
by a neutral stream could result in a system of ionospheric currents
and magnetospheric motions of the form assumed by axford and hines
   /
10833
sq and ocean  a theory of electromagnetic induction is derived and
applied to the induction by sq in a vast ocean
   /
10834
magnetic field micropulsations and electron bremsstrahlung  enhanced
magnetic micropulsation activity in the auroral zone has been observed
to coincide with the increased intensity of bremsstrahlung from
energetic electrons
   /
10835
the stability of the interface between the solar wind ad the geomagnetic
field  surface magnetometer data are presented as evidence of the
stability of the interface between the solar wind and the geomagnetic
field  hydromagnetic waves are assumed to be generated by fluctuations
in the energy density of the solar wind rather than by turbulence
or gross instability at the interface
   /
10836
note on hydromagnetic propagation and geomagnetic field stability
the use of surface magnetic data in estimating the conditions in
the exosphere s is criticized  inferences from suf surface magnetometers
are not consistent with measurements obtained from space probes
   /
10837
a unifying theory of high latitude geophysical phenomena and geomagnetic
storms  a convection system set up in the magnetosphere by viscous
interaction between the magnetosphere and a solar wind or by other
sources could account for a wide variety of observed high latitude
geophysical phenomena and storm time variations
   /
10838
total atmospheric ozone and geomagnetic activity
   /
10839
note on the autocorrelation coefficient of and its relation to regions
results of ward for the period april march are consistent with the
theory of the existence of long lived regions on the sun  autocorrelation
functions plotted for other periods are given by ward
   /
10840
a simple method for the supervision of the orbital period of artificial
satellites  a graphical method of detecting changes in orbital period
on progression charts
   /
10841
infrared and reflected solar radiation measurements from the tiros
meteorological satellite
   /
10842
observations on the possible influence of cosmic radiation on transistor
life in space satellites  the concentration of cosmic radiation in
the van allen belts and the possible effect of this on transistors
in communications satellites are discussed with reference to observational
results
   /
10843
solar flare tritium in a recovered satellite  unusually high ritium
content present in samples of recovered discoverer satellite is interpreted
as due to flux of incident tritons from a solar flare
   /
10844
an hf radar search for possible effects of earth satellites upon
the upper atmosphere  the radar used had a frequency of peak power
of and aerial gain  the results showed no evidence that backscatter
anomalies observed were caused by earth satellites
   /
10845
orbiting spectrometer plots solar x rays  pulse analyser and counter
circuits in the scout satellite for investigations in the wavelength
range are described
   /
10846
bursts during the last few periods of
   /
10847
ionospheric contributions to the doppler shift at vhf from near earth
satellites
   /
10848
effect of major meteoric showers on the densities of the upper atmosphere
preliminary analysis of density data obtained from satellite
measurements at about and indicates density increases during major
showers
   /
10849
note on a mechanism for the vertical transport of ionization in the
ionosphere  vertically travelling gravity waves can produce corresponding
vertical movements of dense layers of ionization which are formed
at alternate nodes of the wave system  the combined effects of coexistent
standing and travelling waves are considered
   /
10850
determination of electron density profiles in the ionosphere neglecting
the influence of the magnetic field  a rapid method is described
for determining nighttime layer electron density given base height
critical frequency and factor  though less z accurate than other
methods it is not dependent on the quality of ionograms
   /
10851
determination of electron density profiles in the ionosphere taking
account of the earths magnetic field  an addition to the original
theory
   /
10852
on the index of refraction in the ionosphere  the forces acting on
an electron in an ionized gas are enumerated  it is confirmed that
in the ionosphere the lorentz polarization force is annulled by the
effects of electron ion collisions and that the refractive index
is given by the sellmeyer formula at radio frequencies
   /
10853
a statistical study of lower atmospheric ionospheric coupling  the
departures of the daily values of from the monthly median were compared
with the calculated large scale vertical motion in the atmosphere
at heights up to km  no association between the two parameters was
found at five stations in canada and the usa
   /
10854
the interpretation and synthesis of certain spread f configurations
appearing on equatorial ionograms  computer ray tracing to thin irregularities
in the equatorial ionosphere explains three classes of spread
f  from synthesized ionograms it is possible to deduce the position
size and drift velocities of patches of irregularities
   /
10855
a waveguide interpretation of temperate latitude spread f on equatorial
ionograms  the striated nature of frequency spreading on equatorial
ionograms is tentatively explained by energy trapping between thick
field aligned ionospheric irregularities
   /
10856
excessive ionization in the lower ionosphere and instabilities in
the outer radiation belt  absorption anomalies in the lower ionosphere
are interpreted on the basis of recent observations of aurorae and
the van allen belts  the analysis of long term measurements indicates
a strong dependence of the ionization effects on sunspot activity
   /
10857
atmospheric scale height as a modifying influence on linear trend
of region electron density with sunspot number  twelve month running
average values of noon maximum electron density and true height of
the layer at christchurch are plotted against twelve month running
average sunspot numbers for the period  a departure from linearity
is apparent above a sunspot number of  it is suggested that increases
in scale height near the sunspot maximum were large enough to modify
the increase in the rate of ion production with a consequent relative
decrease in maximum electron density
   /
10858
electron ion recombination coefficients in nitrogen and oxygen  microwave
determinations of electron density decay during the afterglow
following ionization of gas in a cavity and simultaneous identification
of the afterglow positive ion current by an rf type mass spectrometer
provide information from which recombination coefficients can be
assigned to particular positive ion species
   /
10859
vertical drift of the f layer during negative geomagnetic bay disturbances
disturbances are taken to be negative when and are not both
positive  observational results are compared with theoretical findings
as in previous investigations of  the agreement between geomagnetic
and ionospheric observations is poor
   /
10860
determining local concentrations of charged particles in the ionosphere
and interplanetary space  russian work in the determination of electron
concentration by radio wave dispersion measurements and charged particle
trap experiments is described
   /
10861
the use of probing electrodes in the study of the ionosphere  measurement
of electron concentration and temperature and ion mass spectrum
concentration and temperature by a satellite borne langmuir probe
is considered
   /
10862
the calculation of the electron density in the ionosphere from elevation
angle measurements on artificial satellites  when a transmitting
satellite travels below the peak of the f layer measurements of the
angle of arrival of the received signal show a minimum the value
of which is related to the local satellite electron density
   /
10863
a new versatile ionospheric recorder  the main features of a cheap
portable panoramic recorder are outlined
   /
10864
the effect of collisions on the propagation of radio waves in the
ionosphere
   /
10865
the interpretation of critical frequency measurements  during winter
daylight hours on magnetically quiet days day to day variations of
hourly values of may be due mainly to the presence of travelling
ionospheric disturbances  hence values are only reliable to within
the resulting errors in estimated are also discussed
   /
10866
the graphical distribution of the harmonics of the annual variation
in the critical frequency of the layer at noon  the annual change
in noon at stations has been represented in terms of the first and
second harmonics and a constant term  the term the first harmonic
usually has the same sign in both north and south hemispheres and
in the origin of the winter anomaly in the northern hemisphere  the
amplitude of the second harmonic is greater than expected
   /
10867
the dependence of the fluctuations of the atmospheric refractive
index on meteorological parameters  results of measurements with
a microwave refractometer  measurements were carried out with the
refractometer described in of suspended from a tower
   /
10868
the excitation of airglow by means of radio waves  the theoretical
possibility of producing an artificial airglow in a weakly ionized
gas is investigated and the feasibility of generating this effect
in the ionosphere is discussed  see also
   /
10869
theory of auroral bombardment  the theory covers the drift motions
of particles in a dipole field perturbations of the pitch angles
produced by local magnetic and electric fields the growth of electrostatic
potential and perturbations of drift motions by magnetic disturbances
and electric fields
   /
10870
on the statistical properties of optical and radio aurora  an investigation
of latitudinal and diurnal variation of auroral forms and the
correlation between optical and radio aurora
   /
10871
solar flare effects on and atmospheric radio noise  solar flares
have been analysed and a positive relation between them and short
time noise power decreases has been found  the most significant noise
fade outs occurred when the sun was ovr one of the major noise centres
contributing to the noise at the recording station
   /
10872
definition and measurement of the mean field of pulse type atmospherics
the mean effect on a receiver with tuned circuits and linear detection
of short pulses at is very similar to that of an em field with an
effective electric component  eing the effective height of the aerial
for the aerial for the frequency to which the receiver is tuned
   /
10873
use of coherent memory filter in spectral measurements of atmospheric
whistlers
   /
10874
a study of the playback process of a magnetic ring head  a simplified
gap loss function is given for the case of finite parameters for
tape and head
   /
10875
superconductive computers  factors involved in present and future
use of super conductive components are assessed  new approaches to
the design of superconductive storage systems are reviewed
   /
10876
forming semi permanent memories with metal card storage  presence
or absence of a metal shield between two closely spaced coils has
a large effect on their mutual inductance  the principle is used
to build a read only memory whose content is determined by thin metal
cards
   /
10877
the transfluxor as analogue storage device
   /
10878
tentative recommendations for the definition z and testing of the
dynamic performance of analogue to digital converters  methods of
classifying specifying and testing shaft position and analogue voltage
digital converters are suggested
   /
10879
the reliability of components in satellites  the effects of the special
hazards on component design and development for space vehicles are
reviewed
   /
10880
new phase and frequency comparison circuits  a method is described
for producing a rectified voltage which is a function of the phase
and frequency difference of two alternating voltages  it is particularly
suitable for pulse shaped waveforms and its application for synchronizing
systems in television receivers is examined in detail
   /
10881
vacuum deposited metal film resistors  detailed description of the
problems and procedure involved in the production and testing of
film resistors
   /
10882
noise performance in tin oxide resistors  noise measurements show
up resistor defects not found by standard tests
   /
10883
on the process of flux reversal in multiaperture ferrite cores  experimental
results for two aperture cores are presented and a model is
suggested to represent the flux state within a two aperture core
for various winding circuit combinations
   /
10884
silicon junction diodes as variable capacitors  expressions are given
defining barrier width and junction capacitance and methods of measuring
the latter are suggested  various applications of diode capacitors
are described the temperature dependence of the capacitance is a
hanicap
   /
10885
resistance and frequency variations due to unwanted modes in quartz
crystals  a numerical relation is shown to exist between the peak
resistance increase and peak frequency departure caused by an unwanted
mechanically coupled mode  the value provides a useful means of estimating
frequency departures and determining whether a particular crystal
is satisfactory
   /
10886
circuits with nonlinear resistance  an extension of the study of
series circuits with diodes of to the behaviour of parallel combinations
of circuit elements each circuit containing a diode as a nonlinear
resistance
   /
10887
the calculation of the numerical values of the elliptic functions
for tchebycheff type filters  formulae suitable for handling by automatic
computers are derived for the solution of jacobis elliptic functions
   /
10888
restrictions on the natural frequencies of an network  theory is
developed suitable for application in the synthesis of passive and
active networks
   /
10889
tunnel diodes for low level triggers  a sensitive low level circuit
uses a tunnel diode to drive a schmitt trigger
   /
10890
simulating nerve networks with four layer diodes  a note on the operation
of a neuristor model
   /
10891
efficiency of frequency multipliers using charge storage effect
in general highest efficiency is obtained by cascading lower order
multipliers based on the depletion layer effect but the power rating
of the charge storage type is considerably higher
   /
10892
a tunnel diode wide band frequency doubling circuit
   /
10893
generation of microwave harmonics in an electrodeless discharge at
low pressure  methods of producing rf harmonic power in an ionized
gas are reviewed and an experimental arrangement is described which
shows improved efficiency at a fundamental wavelength of
   /
10894
three level maser action in gas part theory of multiple quantum transition
and doppler effect in three level gas maser
   /
10895
cross relaxation effects in a ruby l band maser at low magnetic fields
the reversals of maser h behaviour on cooling from to are explained
in terms of cross relaxation transitions involving triple spin flips
   /
10896
parametric circuits with nonlinear inductances in the lower frequency
range  extension of earlier analysis of to cover nonlinear inductances
and their application in amplifiers up converters and down converters
results of experiments using a ferrite core as nonlinear element
at af are discussed
   /
10897
a travelling wave variable reactance type parametric amplifier a
full description of the amplifier previously noted in of
   /
10898
a resonant slot parametric amplifier  brief description of a varactor
diode amplifier for operation in the range
   /
10899
an extremely wide a band tunable s band parametric amplifier  the
range covered is by mechanically tuning the pump circuit and shifting
the frequency of the pump source  by the latter means alone the amplifier
can be tuned over a band
   /
10900
a dc pumped amplifier with a two dimensional field structure
   /
10901
stability criteria for a tunnel diode amplifier  analysis of a type
of circuit also considered by hines
   /
10902
a tunnel diode frequency multiplier with gain  the multiplier described
is based on the nonlinear negative resistance characteristic of a
tunnel diode and shows a voltage gain for the second and third harmonics
   /
10903
a simple phase detector  a phase sensitive detector is described
for use when the reference and variable signals have a common terminal
   /
10904
crystal detectors to cover the frequency band
   /
10905
an audio frequency phase modulator using pulse techniques  the range
of phase shift of the carrier is and departure from linearity as
a function of the magnitude of modulation input is less than
   /
10906
the movement of charge carriers in gases with crossed electric and
magnetic fields  the cases discussed are static magnetic field with
alternating electric field at right angles both fields static and
both fields alternating synchronously
   /
10907
theory of impurity resistance in metals part  the many body theory
developed in a previous paper of is extended to include all corrections
resulting from electron electron interactions
   /
10908
self trapping of an electron by the acoustical mode of lattice vibration
when the coupling constant between the electron and acoustic mode
vibration exceeds a critical value the effective mass of the electron
increases discontinuously and the electron takes a localized self
trapping state as an eigenstate
   /
10909
transient effects in peltier coolers  addendum to
   /
10910
new derivation of the vacuum breakdown equation relating breakdown
voltage and electrode separation
   /
10911
practical calculation of the defocusing influence of the space charge
application to relativistic electron beams
   /
10912
interaction of a modulated electron beam with a plasma  report on
theoretical and experimental investigations of the interaction between
a microwave modulated electron beam and a mercury arc discharge and
of the interaction between a modulated electron beam and a slow es
wave on a plasma column
   /
10913
transport equations for plasmas in strong external fields  coupling
of plasma particles to a strong electric field can greatly exceed
their mutual coupling and this is shown to lead to a vlasov type
transport equation
   /
10914
values of the transport coefficients in a plasma for any degree of
ionization based on a maxwellian distribution  values for electrical
conductivity for any degree of ionization steady magnetic field and
various electron neutral collision laws are presented  other transport
coefficients are tabulated  the analysis uses the fokker planck and
boltzmann equations
   /
10915
generation and application of highly ionized quiescent cesium plasma
in steady state  plasma densities at greater than ionization have
been obtained by the method described
   /
10916
plasma physics an elementary review  a summary o of the role of plasma
physics in current scientific research
   /
10917
the electrical conductivity of a partially ionized gas  analysis
taking account of both electron particle and coulomb type collisions
but neglecting the effects of inelastic collisions and a steady magnetic
field
   /
10918
oscillations and noise in low pressure dc discharges  a review of
experimental investigations of oscillations and fluctuations which
occur spontaneously or through excitation in low pressure hot cathode
plasmas  methods of reducing these effects are discussed
   /
10919
antiferromagnetic susceptibility of the plane triangular ising lattice
the antiferromagnetic susceptibility of the plane triangular ising
lattice is calculated in terms of a power series for all temperatures
   /
10920
the magnetic field in the vicinity of obliquely magnetized cylindrical
bodies  the field distribution has been calculated and plotted for
three different cases of oblique magnetization
   /
10921
magnetization curve of an infinite cylinder  calculations are made
for an infinite ferromagnetic cylinder with negative uniaxial anisotropy
   /
10922
the reciprocity theorem of electromagnetic theory  an examination
of the work of several authors in order to present the theorem in
the clearest way with emphasis on the physical hypotheses which are
the basis of the principle
   /
10923
magnetohydrodynamic waves in cylindrical waveguides and toroidal
resonators  investigation of small amplitude magnetohydrodynamic
waves in rectangular and circular waveguides and of standing waves
in a toroidal resonator
   /
10924
radiation from a modulated electron beam with a plasma background
expressions are derived for the electromagnetic radiation of current
modulated electron beams which emerge from a plasma  simple expressions
are derived in the case where the dielectric constant of the plasma
is zero or infinity
   /
10925
diffraction of electromagnetic wates by sound waves  the diffraction
amplitude is calculated from borns approximation  results of measurements
on microwaves affected by a standing sound frequency and polarization
of the em waves
   /
10926
transmission and reflection of electromagnetic waves at a plasma
boundary for arbitrary angles of incidence  a plane em wave horizontally
or vertically polarized incident at an arbitrary angle on a flat
plasma boundary is investigated  numerical results showing variation
of attenuation and phase power entering the plasma and ellipticity
of the reflected wave are presented
   /
10927
some features of the transverse propagation of high frequency waves
in a magneto active plasma  mathematical analysis based on the kinetic
equations of nonrelativistic theory for a simple case of transverse
wave propagation in a uniform plasma located in a constant magnetic
field  the effect of electron collisions with other particles is
neglected
   /
10928
magneto ionic theory for a fully ionized hydrogen plasma  the effects
of electron proton and electron electron collisions on the real refractive
index and the absorptivity are evaluated for electromagnetic
wave propagation in a fully ionized hydrogen plasma under the influence
of an external magnetic field  the appleton hartree magneto ionic
formula as generally applied to the solar ionosphere is retrieved
in a limiting case with the conventionally adopted expression for
the effective electron proton collision frequency  electron electron
collisions are significant only in the realm of gyro resonance where
they diminish the absorptivity due to electron proton encounters
   /
10929
frequency conversion in a microwave discharge  analysis of the nonlinearity
of a microwave discharge between two closely spaced parallel
plates of dimensions small compared to  parametric amplification
in a discharge is briefly considered
   /
10930
interaction of microwaves in gaseous plasmas immersed in magnetic
fields  experimental investigation of the interaction of two or more
em waves guided through a magnetoplasma medium with particular consideration
of em energy transfer and its effects
   /
10931
measurement of the refractive index of lucite by recoilless resonance
absorption  details are given of a method of modulating the frequency
of a monochromatic em wave by varying the optical pathe length between
the source and detector  in the application described a small frequency
shift in radiation is detected by recoilless resonance absorption
   /
10932
electron paramagnetic resonance for metals with two conduction bands
   /
10933
ferromagnetic relaxation part  the role of four magnon processes
in relaxing the magnetization in ferromagnetic insulators  the effect
of the exchange induced four magnon process should be observable
in parallel pumping experiments  four magnon processes arising from
dipole cubic anisotropy and exchange coupling are not very effective
in relaxing the uniform precession
   /
10934
contribution to the study of ferrimagnetic resonance curves  theoretical
considerations techniques for measurement of magnetic parameters
and results of experiment are discussed
   /
10935
relaxation equations for two magnon and magnon phonon processes in
ferrimagnetic resonance  equations giving the relaxation behaviour
of the magnetization in the case of ferrimagnetic resonance are derived
from quantum mechanical rate equations for spin wave magnons
   /
10936
detection of spin magnetization variation in a two level maser oscillator
a neutron irradiated sample containing about spins was mounted
in a rectangular plastic cavity resonator with field sweep excitation
oscillations were detected which established the existence of variations
of
   /
10937
three level maser action in gas theory of multiple quantum transition
and doppler effect in three level gas maser  discussion of the multiple
quantum process for the off resonance condition  the intensity of
the emission produced is calculated using perturbation theory as
well as the more general javans theory  the doppler effect is analysed
from semiclassical and quantum mechanical viewpoints
   /
10938
lasers devices and systems parts  an illustrated review covering
communications range finding and detection military and computing
applications and methods of modulation scientific medical and other
devices  part
   /
10939
proposed harmonic generator or mixer for optical frequencies  limitations
of the mixer suggested by laine of are discussed and s simpler
alternative device using liquid caesium is described
   /
10940
observation of optical maser oscillation in ruby  a note on experimental
results obtained using multiple dielectric layers as mirrors in the
maser cavity
   /
10941
mode characteristics and coherence in optical ruby masers  a discussion
of a series of interference experiments in which oscillations are
shown to occur at several different frequencies corressponding to
various numbers of half wavelengths between the reflecting ends of
the ruby
   /
10942
a ruby laser exhibiting periodic relaxation oscillations generated
by the optical maser described may make it useful for ranging applications
   /
10943
design of a helium neon gaseous optical maser  constructional details
of the optical maser described in of
   /
10944
coherent light amplification in optically pumped vapour  using the
strong line to produce a population inversion in the vapour a gain
of is predicted for a cell
   /
10945
signal to noise ratios in photo electric mixing  the possibility
of using photoelectric mixing for the linear amplification and frequency
conversion of coherent optical signals is considered
   /
10946
a new application of the faraday magneto optical effect for diagnostic
measurements of transient magnetic fields  by a combination of streak
and optical interference fringe techniques with the magneto optical
method described it is possible to determine field geometry space
time distribution of electron number density in a high density plasma
and line integrated variations of magnetic field
   /
10947
radio frequency discharges in magnetic fields  report on investigations
of discharges in with the magnetic field normal to the rf electric
field
   /
10948
drift velocity of a charged particle in an inhomogeneous magnetic
field  a class of magnetic fields is defined for which the drift
velocity may be calculated exactly
   /
10949
energy band structure of solids from a perturbation on the empty
lattice
   /
10950
instability of antiferromagnetic screw type structure of an electron
gas  an analysis by the self consistent field method of a screw type
structure in a free electron gas such as that proposed by overhauser
proves that it is always unstable  the susceptibility of such a gas
is also derived by the same method
   /
10951
on the origin of radio emission from cosmic clouds  the balance between
absorption and stimulated emission for free free transitions in a
gas plasma can lead to a negative as well as a positive effective
absorption coefficient and hence to amplification of the spontaneous
emission
   /
10952
the australian national radio astronomy observatory  a brief description
of the inauguration of the observatory at parkes and of its first
instrument a steerable paraboloid
   /
10953
report of the advisory panel on radio telescopes  special reference
is made to the feasibility and cost of constructing a beam aerial
operating at
   /
10954
operation at the medicina station of a radio telescope  a description
of an interferometer type radio telescope which consists of a cylindrical
parabolic aerial long and wide at the focus of which are full
wave dipoles
   /
10955
a radio survey of the galactic plane at a frequency of parts  of
discrete sources observed most lie within of the galactic plane and
about are thermal  continuum observations show large scale features
which can be interpreted in terms of a spiral model of the galaxy
if independent distributions for thermal and nonthermal emission
are postulated
   /
10956
recent decametre wavelength observations of jupiter saturn and venus
observations made during show that only jupiter appears to emit extensive
nonthermal radio noise
   /
10957
presence and correlation of fine structure in jovian decametric radiation
results obtained from spaced receiver observations of noise storms
of jupiter showed correlation of fine structure components having
durations of the order of hundredths of a second for receiving sites
apart
   /
10958
solar emission at millimetre wavelengths  solar flux density measurements
at indicate that the radiation is primarily from the photosphere
and corresponds to the thermal radiation from a black body at
   /
10959
some solar studies on the occurrence of type solar bursts of continuum
radiation  type solar emission in the frequency range occurs in two
phases  the first usually observed at frequencies higher than appears
to be emitted low in the chromosphere from a source of angular size
the second occurs high in the corona with a source size or more
   /
10960
thermal radio emission from the transition layer chromosphere corona
two models of the transition layer are computed using new values
of emission and absorption coefficients  comparison with recent observations
shows that the models predict decimetre wave emission with
reasonable accuracy
   /
10961
the radio brightness distribution on the sun at from combined eclipse
and pencil beam observations  radio bright regions appear to overlie
the optical plages faculaires at a height of about and show similarity
in size shape and relative intensity  a higher peak temperature and
gradient for the limb brightening was revealed
   /
10962
the spectral components of major solar radio events  characteristics
of solar radio events are listed together with the associated flare
and ionospheric data the distribution of storm associated flares
over the sun and the variation of storm occurrence with sunspot cycle
are noted
   /
10963
observations of radio sources at wavelength  observations of radiation
from cas tau orion nebula and are described
   /
10964
stimulated emission of the fine structure line of hydrogen in diffuse
nebulae
   /
10965
radio sources and clusters of galaxies  the result is given of a
comparison of positions of radio sources in the catalogue with positions
of rich clusters of galaxies  see also of
   /
10966
a note on the unusual variations of cosmic ray intensity during the
period november to  unique features of cosmic ray observations are
described including effects on the earths magnetic field and effects
produced by the interplanetary magnetic field  well defined solar
particle trapping regions appear to exist in the inner solar system
the preferential arrival of particles from directions well to the
west of the sun is discussed
   /
10967
an analysis of the solar daily variations of the primary cosmic radiation
measured with the igy neutron monitor network  the results of
a harmonic analysis of monthly averaged data from world wide monitoring
stations show no asymmetry in amplitude or time of maximum for the
northern and southern hemispheres
   /
10968
diurnal variation and forbush decrease  an examion of the depressions
which often precede the largest forbush type decreases by less than
   /
10969
the primary cosmic ray electron flux during a forbush type decrease
balloon observations indicate a decrease of in the electron flux
during a forbush decrease  it is suggested that the primary electrons
are of galactic and not of solar origin
   /
10970
spatial distribution of electrons from neutron decay in the outer
radiation belt  the spatial distribution of electrons in the outer
radiation belt is calculated theoretically assuming as a source the
decay products of albedo neutrons  there is moderate agreement with
satellite results
   /
10971
coordinates for mapping the distribution of magnetically trapped
particles
   /
10972
measurements of cosmic rays on geophysical rockets the rocket equipment
and the results obtained during one flight are described
   /
10973
radio wave scattering from the lunar surface  measurements on the
angular scattering properties of the lunar surface at are described
for angles of incidence at least scattering is independent of over
the range of
   /
10974
the radar cross section of the moon  reply to criticism of the theory
of scattering from the moons surface proposed in
   /
10975
magnetohydrodynamic interpretation of sunsport activity
   /
10976
sunspot cycles  a discussion of problems met in attempting to forecast
sunspot conditions  a simple analysis is made of data from the complete
cycles so far recorded
   /
10977
the theory of electric currents in the magnetosphere  in the brief
theoretical treatment given the plasma of the magnetosphere is replaced
by a particle gas with diamagnetic properties
   /
10978
interaction of west ford needles with the earths magnetosphere and
their lifetime  a discussion of the effects of the charge built up
on the needles passing through the magnetosphere  the uncertainty
of the lifetime of the needles is illustrated by calculations showing
that they may re enter the atmosphere in any period from a few months
to a century
   /
10979
rapid geomagnetic fluctuations  an investigation of oscillations
at in the earths magnetic field measured in the archipelago of stockholm
between july and june
   /
10980
formation of the geomagnetic storm main phase ring current  the main
phase ring current is supposed to be generated by heating the exospheric
gas by hydromagnetic shock waves  the more energetic component consists
of protons  a flux hydrogen atoms should be observed at the base
of the exosphere and the decay time of the ring should be less at
sunspot minimum than at sunspot maximum by a factor of three
   /
10981
spectrum of hydromagnetic waves in the exosphere  the influence of
the earths gravitational field on hydromagnetic wave propagation
is discussed and the limiting conditions for the propagation of the
various modes in the exosphere are considered
   /
10982
travelling pressure waves associated with geomagnetic activity  records
obtained at washington frequently indicate the occurrence of travelling
pressure waves with periods of during intervals of high geomagnetic
activity
   /
10983
variations of the earths exosphere and geomagnetic disturbances during
the geomagnetic storm of september  geomagnetic data and observations
on trapped particles in the outer radiation belt have been studied
and a simple model of the state of the exosphere during the main
phase of the f storm has been proposed
   /
10984
missile and space electronics  applications of electronics in future
space projects are described  a schedule of launchings for the next
years is given
   /
10985
determination of illumination conditions and periods of an artificial
satellite in shadow and in sunlight  a method of determining the
illumination conditions of a satellite is described and a brief analysis
of the paths of th  first three soviet satellites is given
   /
10986
influence of the earths oblateness on the rotational motion of an
artificial satellite  the equations of motion are set up and the
small oscillations of the satellite relative to the orbital system
of coordinates are studied
   /
10987
variations in the positive ion concentration with altitude from data
of mass spectrometry measurements on the third satellite  mass spectrometer
measurements of the ion concentration are compared with measurements
of electron concentration obtained from radio observations of the
first and third soviet satellites and with measurements of positive
ion concentration obtained with positive ion traps installed on the
third soviet satellite
   /
10988
irregularities in atmospheric densities deduced from satellite observations
results of observations of atmospheric drag on satellites indicate
a pronounced diurnal bulge lagging behind the subsolar point erratic
fluctuations of the atmosphere above due to solar radiation and irregular
perturbations of the upper atmosphere associated with magnetic
storms
   /
10989
a theoretical model of temperature variations at the surface of an
orbiting satellite
   /
10990
winds in the upper atmosphere  results are given of a five year study
of winds at heights of obtained from radar observation of ionized
meteor trails  diurnal and seasonal variations are described in detail
   /
10991
radar investigations of the upper atmosphere  the parameters of the
radar transmitters to be used with the two parabolic reflectors at
defford near malvern are given and possible experimental investigations
of ionization are discussed
   /
10992
a working model for the upper atmosphere  the validity of a model
by nicolet is examined and some comparisons made with that proposed
earlier of
   /
10993
fluctuations of electron density in the ionosphere  discussion of
turbulent fluctuations in the lower ionosphere where the frequency
of ion collisions with neutral particles is large compared to the
larmor frequency
   /
10994
theory of electrostatic fields in the ionosphere at polar and middle
geomagnetic latitudes  discussion of paper by spreiter and briggs
of and criticism of daggs theory of the formation of irregularities
in the f region of and
   /
10995
two methods of detecting ionospheric disturbances  describes rapid
visual methods for detecting f region disturbances by the distortion
of traces on ionograms
   /
10996
simultaneous study of drifts at different levels in the ionosphere
by the spaced receiver method  by comparing drift speeds in the and
regions the effect of a lower layer on upper layer drift measurements
is deduced and drift gradients are estimated
   /
10997
the varying electron density profile of the f region during magnetically
quiet nights  local height changes of about lasting for are illustrated
the general increase in height before midnight and the pre sunrise
decrease are found to be independent o of season  severe vertical
movements induced by a magnetic bay were not accompanied by spread
echoes
   /
10998
the heat balance of the f region and the saturation effect  as the
input of solar ultraviolet radiation to the f region increases with
increasing solar activity the volume rate of production of ionization
increases to a certain point and thereafter decreases
   /
10999
the morphology of lunar semidiurnal variation in near solar noon
within about of the magnetic equator the phase of the lunar semidiurnal
variation in is almost opposite to that observed elsewhere the amplitude
of the variation is greatest at the equator and near magnetic latitudes
where it is about of
   /
11000
further evidence of a long term variation in the relationship of
solar activity to the ionosphere  there is evidence that since there
has been a decrease in the amount of ionization in the layer for
a given sunspot number  a similar conclusion was reached for the
e layer
   /
11001
round the world sound waves produced by the nuclear explosion on
october and their effect on the ionosphere at sodankyla  microbarograph
and ionosonde recordings of the explosion are described  disturbances
due to direct travelling waves and round the world waves were detected
on each instrument
   /
11002
increase of ionization associated with geomagnetic sudden commencements
increases of cosmic noise absorption in high latitudes seem to be
associated with certain types of ssc
   /
11003
measurements of electron concentration in the ionosphere up to altitudes
of carried out during the international geophysical year by means
of radio wave transmissions from the geophysical rockets of the academy
of sciences ussr  the determination of electron density distributions
from measurements of radio wave dispersion and the faraday effect
are examined  the results of three rocket flights to altitudes of
in are described
   /
11004
generalized appleton hartree equation for any degree of ionization
and application t the ionosphere  the equation derived is applicable
to any variation of electron collision frequency with electron speed
and any degree of ionization  results for the ionosphere are compared
with experimental data  e layer results can be explained by assuming
a electron temperature several times higher than the gas temperature
   /
11005
the absorption of radio waves in the ionosphere with respect to geomagnetic
current control and other proposed me models a critical survey
a critical survey is given of the work of appleton and piggott of
bandyopadhyay of and rumi  serious errors arise because of the neglect
of deviative absorption in the e region
   /
11006
properties of the outer ionosphere deduced from nose whistlers  analysis
of nose whistler data shows that the electron density in the outer
ionosphere is proportional to the geomagnetic field strength with
a annual variation
   /
11007
auroral investigations during the winter seasons and their bearing
on solar terrestrial relationships  the results of spectral investigations
of aurorae at oslo and tromso
   /
11008
some results of investigations of aurorae and night airglow during
the igy and igc  a review of ussr results and a discussion of their
interpretation
   /
11009
circular symmetry in the geomagnetic plane for aurora phenomena
projections of circles in the geomagnetic equatorial plane on to
the earths surface along the real geomagnetic field lines are compared
with published observational data for the northern and southern auroral
zones
   /
11010
a morning discontinuity in the orientation of the quiet auroral arcs
   /
11011
on the association of radio reflections with optical aurora  the
observations provide no basis for assuming that optical and radio
aurora are independent phenomena
   /
11012
the azimuthal distribution of ultra high frequency radar echoes from
aurora  partial analysis in range and azimuth of radar echoes at
with diameter paraboloid aerials  contours of constant echo occurrence
are different in the two periods before and after midnight
   /
11013
determination of radar auroral heights with the prince albert radar
   /
11014
measurement of very low frequency atmospherics at bonn  report on
measurements in the frequency range close agreement was found with
earlier results obtained by of
   /
11015
propagation characteristics of whistlers trapped in field aligned
columns of enhanced ionization  whistler data are examined using
ray theory to deduce properties o field aligned ducts in the outer
atmosphere
   /
11016
electromagnetic radiation from solar corpuscular streams  some objections
are raised to a paper by mac arthur of and theory is developed
for the case of superlight motion when the particle velocity is greater
than the phase velocity of the emitted waves
   /
11017
correlation between low frequency radio noise and magnetic and cosmic
ray storms  measurements at poitiers and limeil show that vlf radio
noise starts about after an ssc a maximum being reached about after
the ssc  the maximum noise occurs at the maximum of cosmic ray storms
   /
11018
geomagnetic activity and the reception of whistlers in polar regions
data on whistler reception at scott base antarctica are discussed
the frequency of occurrence of whistlers shows a diurnal variation
and decreases with increasing geomagnetic activity
   /
11019
some ionospheric results obtained during the international geophysical
year
   /
11020
some thermal considerations on the use of solar cells in space vehicles
the radiation balance of solar cells in space is discussed for different
configurations of the cell assembly and different orbits  surface
coatings are considered
   /
11021
a cryotron memory cell  an improved versatile storage cell consisting
of three cryotrons and one superconductive loop is described
   /
11022
high speed logic circuits using common base transistors and tunnel
diodes
   /
11023
digital function generation with torsional delay lines  a torsional
magnetostriction delay line has small magnets to replace the usual
control taps  since the magnets do not load the line a large number
of taps each equivalent to one bit may be used with one common output
   /
11024
envelope feedback in an audio frequency amplitude modulator  the
amplitude modulator is designed to transmit solution information
when a composite computing scheme consisting of an analogue computer
and a network analyser is used to solve problems concerning generator
and load transients
   /
11025
the logic potential of molecular electronics in the multicollector
transistor  methods of applying the techniques of molecular electronics
to form logic circuits are discussed with emphasis on the two collector
transistor of  the logical effects of more collectors are briefly
considered
   /
11026
microsystems and molecular electronics  a special issue containing
nine papers describing the need for microsystems and designs for
modular and solid state circuits  the last three papers are abstracted
separately
   /
11027
microsystem circuit analysis  a general method for analysing film
type networks based on the theory of indefinite matrices is presented
simple rules are developed for generating sub networks from a given
four terminal network
   /
11028
a fatigue test for printed wiring boards and through connections
a krouse flat plate fatigue testing machine was modified to take
the larger specimens to be examined  typical test data are presented
in the form of strain cycle life diagrams
   /
11029
developing the hall generator equivalent circuit  the basic phenomena
occurring in the device are described in matrix form and an equivalent
circuit is derived by matrix manipulation  current gain voltage gain
and input impedance are found in terms of the equivalent circuit
parameters
   /
11030
nonlinear and controllable inductances made of thin and magnetic
films  the inductance considered which may be used for parametric
amplification takes the form of a thin ferromagnetic film in a magnetizing
coil  the effect of film premagnetization on the inductance value
is calculated  experimental results obtained for a coaxial oscillator
system are compared with theory
   /
11031
ferrite core current steering comutators and ring counters  commutating
circuits are described which steer well defined current pulses sequentially
along a number of paths and simplified design formulae are given
   /
11032
duality relations between threshold type switching functions and
their application to problems of synthesis
   /
11033
thin film capacitors using tantalum oxide dielectrics prepared by
reactive sputtering  a note on the method of preparation and measured
characteristics
   /
11034
the transient response of linear passive networks to phase modulated
signals  some simple networks are stimulated by a sinusoidal signal
phase modulated by a step input  analytical solutions are verified
experimentally and with an analogue computer
   /
11035
parametric behaviour of an ideal two frequency varactor  an analysis
in which pump and signal voltages of large amplitude are allowed
and the complete varactor characteristic is used  with linear signal
termination the ratio of signal to pump frequency must be where is
an integer  all possible operating modes are identified
   /
11036
a synthesis procedure  the synthesis of symmetrical reactance networks
with equal terminations is considered  from the insertion loss characteristic
the impedance which the half circuit presents at the axis
of symmetry is derived from network theory and the complete circuit
is obtained by back to back connection of the two halves
   /
11037
the representation of ladder network parameters through continued
fraction polynomials  euler polynomials are used to derive concise
expressions for the transmission parameters of linear ladder networks
in terms of the branch and terminating immittances  a generalized
form of the polynomials is helpful in the design of reactively coupled
multiple tuned narrow band pass filters
   /
11038
band pass filters having quasi symmetrical attenuation and group
delay characteristics  description of design procedure and report
on experimental results
   /
11039
integrating and differentiating circuits applications to filtering
and to z acoustics  the basic circuits and the effect of successive
operations on speech and music signals are considered  a detailed
study is made of an if band stop filter derived by linear combination
of differentiating and integrating circuits  its applications in
a distortion meter selective amplifier and df oscillator are described
   /
11040
harmonic generation and frequency mixing in ferromagnetic insulators
calculations are made of second harmonic generation and second order
frequency mixing for small ellipsoidal samples with loss included
in the landau lifshitz form  examples are given and a simple case
of third harmonic generation is discussed  detailed calculations
are given elsewhere
   /
11041
background noise in oscillators with rf pushing  an extension of
previous work to include non linearities in which the frequency of
oscillation is a function of oscillation amplitude
   /
11042
an indirect method for the exact solution of the oscillator equation
by establishing the characteristic of the oscillator in the phase
plane exact solutions of the nonlinear differential equation involved
can be found  the characteristics of these solutions are discussed
for english
   /
11043
transfluxor frequency memory  a transfluxor is used as the frequency
control component of a magnetically coupled multivibrator
   /
11044
sawtooth generator with almost infinite linearity  the miller integrator
using junction transistors is analysed maximum linearity is achieved
with the transistor operating without feedback in an earthed base
circuit  practical circuits for generating various sawtooth waveforms
are given
   /
11045
an analysis of the dc design considerations of a transistorized schmitt
trigger parts design difficultes are reduced by establishing first
the necessary and second the desirable requirements so that the number
of variable parameters is mu minimized
   /
11046
voltage controlled wide range oscillator  the variation of the small
signal impedance of a junction diode with bias is used to give a
voltage controlled phase shift
   /
11047
study of transients in similar electrical networks  the transient
characteristics of equivalent networks obtained by frequency or impedance
transformation are analysed  for english version
   /
11048
new high speed counter divider  the unit will count and divide by
any number up to at  operation at frequencies up to should be possible
   /
11049
a self indicating magnetic scaling system using electro deposited
nickel iron film cores  details are given of a magnetic decade scaling
system in which direct count indication is obtained by using the
external magnetic fields of the storage cores themselves  with the
electro deposition technique described the difficulty of getting
sufficiently close coupling between the film and the associated driving
and sense coils has been overcome
   /
11050
theory design and performance of maximum efficiency variable reactance
frequency multipliers  the maximum efficiency with a given nonlinear
element and circuitry is predicted from the analysis and circuit
configurations for improved efficiency at a given harmonic are indicated
   /
11051
choice of collector load resistance for minimum harmonic distortion
a graphical method for calculating the optimum load to minimize harmonic
distortion in transistor amplifiers
   /
11052
the earthed collector circuit as an amplifier withe high input impedance
the earthed collector circuit configuration is analysed and expressions
are obtained for its input impedance and frequency response
calculated and measured results are compared and circuit stability
limits are discussed
   /
11053
wide band amplifiers tuned or aperiodic using transistors up to
stabilization of circuits against varying ambient temperature frequency
compensation in aperiodic amplifiers design of distributed amplifiers
and gain control of tuned amplifiers are examined
   /
11054
adiabatic rapid passage in ruby at wavelengths  performance data
are giten on a two level ruby maser operating at with a modulated
magnetic field and using the crystal as a resonant cavity  as an
amplifier it has a gain of and bandwidth as an oscillator it has
an output of
   /
11055
a solid state push pull maser in the millimetre wavelength region
maser oscillation from to was achieved with doped rutile using push
pull pumping at  a short experiment on cross relaxation effects was
also formed
   /
11056
magnetic perturbation of an ammonia maser on the line  theoretical
curves of frequency change as a function of the perturbing field
are given for a line maser  fluctuations of the field by are shown
to give an error of about
   /
11057
dependence of magnetic coupling constant of ammonia on the inversion
state  theoretical studies indicate that in a maser the magnetic
coupling constants of the upper and lower inversion states are different
resulting in the observed dependence of frequency on magnetic field
   /
11058
double beam maser as a primary frequency standard
   /
11059
theory and design of wide band parametric converters  a circuit theory
approach using z linear time varying capacitance with a linear passive
network
   /
11060
diffused silicon mesa diodes for use in refrigerated parametric amplifiers
   /
11061
analysis of fast wave couplers for transverse field beam type parametric
amplifiers
   /
11062
the application of beam cooling to quadrupole amplifiers
   /
11063
quantum fluctuations and noise in parametric processes part  a quantum
mechanical model for parametric interactions is used to evaluate
the effect of the measuring amplifying process on the statistical
properties of radiation  parametric amplifying process on the statistical
properties of radiation  parametric amplification is shown to
be ideal in the sense that it allows a simultaneous determination
of the phase and number of quanta of an electromagnetic wave with
an accuracy which is limited only by the uncertainty principle  frequency
conversion via parametric processes is whown to be free of zero
point fluctuations
   /
11064
rapid modulation of microwaves on a coaxial line with the aid of
ferrites  a signal on a coaxial cable has been modulated to a depth
of at  resonance absorption in a magnetized ferrite tube threaded
on the core of the cable is varied by a coil round the tube  the
modulating field is chosen to operate about a mean value on one flank
of the resonance curve
   /
11065
decreasing the threshold in fm by frequency feedback  the feedback
action of the demodulator is taken into account in determining the
threshold calculated values agree well with experimental data
   /
11066
an automatic frequency controlled phase shift keyed demodulator
the principles of demodulators with binary phase shift keying are
reviewed  design equations are given which indicate the trade off
relations between pull in range noise bandwidth and lock up time
experimental results are given
   /
11067
correlation in the fluctuating outputs from two square law detectors
illuminated by light of any state of coherence and polarization  the
correlation is found by treating light fluctuations as a random process
the expression takes a particularly simple form when the light is
spectrally pure  two special cases are applicable to the hanbury
brown twiss effect of and to correlation experiments with light from
optical masers
   /
11068
thermally stimulated emission and conductivity peaks in the case
of temperature dependent trapping cross sections  original theory
is extended and a method is proposed for determining by a single
experiment the ionization energy and temperature dependent cross
section of a trapping level
   /
11069
stimulated emission into optical whispering modes of spheres  stimulated
emission into optical whispering modes of a spherical sample of has
been observed  light produced by the stimulated emission is radiated
tangentially from each point on the surface of the sphere  the experimental
results have been interpreted in terms of the electromagnetic
analogue of the rayleigh theory of the whispering gallery
   /
11070
modes in sequences of e lenses  an investigation of the modes of
propagation of coherent light iht in a sequence of lenses
   /
11071
quantum theory of free carrier absorption  quantum theory becomes
equivalent to classical boltzmann theory for photon energies small
compared to carrier energies
   /
11072
collective behaviour in solid state plasmas  theoretical investigation
of the nonlinearities in plasma wave instability applied particularly
to the possibility of observing this effect in  scattering mechanisms
may prevent observation
   /
11073
instabilities of a cylindrical electron hole plasma in a magnetic
field  the stability of an electron hole plasma carrying current
parallel to a magnetic field is investigated  instabilities are predicted
and the calculated values of electric field magnetic field and
lowest oscillation frequency are compared with available observations
agreement is reasonably satisfactory
   /
11074
hall effect in impurity conduction  the existence of a nonvanishing
hall effect in the impurity conduction regime of a semiconductor
is demonstrated  the theory is based on a three site transition process
and in particular on a magnetic field dependent contribution to the
jump probability between two sites
   /
11075
a microwave plasma discharge  striae produced in argon by high power
radiation are described and illustrated  their maximum length was
and widthmm
   /
11076
time lags associated with ultra high frequency gas f breakdown  an
investigation of the time lags associated with gas breakdown in correctly
profiled parallel plate gaps at a frequency of
   /
11077
magnetically confined cold cathode gas discharges at low pressures
a theory is developed taking account of the effects of space charge
in inverted and in normal magnetrons and in penning structures  discharges
of much greater intensity may be expected in normal magnetrons
than in inverted magnetrons
   /
11078
electron energy distribution measurements in gas discharges  accuracy
of the distribution determination using the method of druyvestyn
is improved by differentiating the langmuir probe signal and filtering
mains frequency noise from the output  the second differential coefficient
is obtained by graphical differentiation
   /
11079
brillouin flow in relativistic beams  a solution is closed form in
a cylindrical geometry is derived in the limit of low beam temperature
   /
11080
exact solution of the one dimensional bunching problem  a solution
is derived for the bunching of an infinite electron beam modulated
by an infinitesimal gap  the solution is valid when no overtaking
occurs
   /
11081
theory of the potential well produced by multipacting electrons very
low pressure regime  theory of ion behaviour in an electron well
   /
11082
the transverse electric noise from an electron beam  the measurement
of transverse noise provides a means of investigating scattering
phenomena
   /
11083
analysis of double stream interactions in the presence of a finite
axial magnetic field  couplings of fast and slow cyclotron and space
charge waves between two electron beams and between an electron beam
and a plasma are analysed
   /
11084
fluctuations in a plasma ion electron temperature relaxation  the
rate of relaxation calculated on the basis of the fluctuation dissipation
theorem assuming interaction between the ion and the fluctuating
electric field caused by the surrounding electrons is found to agree
with the result obtained considering interactions with individual
electrons
   /
11085
the behaviour of a plasma under the influence of a standing electromagnetic
wave in the absence of a constant magnetic field  the physics
of the radial confinement of an ionized plasma in an em field are
examined for a cylindrical cavity excited in the modes
   /
11086
electroacoustic coupling at the boundary of an ionized medium  an
analysis is developed to explain the production of a reflected sound
wave and a transmitted modified sound wave at the boundary of an
ionized medium when an em wave is incident at the boundary in the
presence of a transverse magnetic field
   /
11087
a proposal to use microwave cavities to study the surface properties
of high density plasmas  the method is based on the resonance properties
of a cavity containing a highly conductive axial plasma rod
   /
11088
a method of measuring the potential distribution in a cylindrical
rf cavity containing plasma  an ion beam is directed through the
plasma and the position velocity and direction of the beam at the
points of entry and exit are determined  by varying the input parameter
the potential of a particular point inside the plasma can be computed
   /
11089
magnetocompressiona disturbance in a tepid plasma  the examination
of steady state pulses travelling at right angles to a magnetic field
in a cold plasma is extended to a tepid plasma  a linear and quasi
nonlinear analysis is given from which it is shown that pulses exist
when the disturbance speed is supersonic
   /
11090
a method for measuring the conductivity in a high electron density
plasma  the interaction between the solenoidal electric field and
a circular cylindrical plasma column is used as the basis for the
design of a pulse operated bridge suitable for transient measurements
of conductivity in high density plasma
   /
11091
the ferromagnetism of the plane lattice  inconsistencies in the results
of the theoretical treatment of ferromagnetism at low temperatures
on the basis of the heisenberg model are discussed
   /
11092
theory of direct exchange in ferromagnetism  a unique definition
of is applied to the following cases on a heisenberg atomic model
hydrogen functions orbitals of the iron series a pair of iron series
atoms in a configuration  it is found to be negative in all cases
the conclusion is that the direct exchange model is inadequate or
inappropriate
   /
11093
mechanical damping due to magnetic processes  the causes of magnetic
damping are analysed with reference to theoretical and experimental
investigations by various authors  the technical implications of
these effects are discussed
   /
11094
anisotropic curie temperature  a theoretical treatment showing how
the curie temperature in an anisotropic ferromagnet varies with the
direction of magnetization
   /
11095
momentum and energy of waves  elementary arguments of conservation
of energy and momentum are used to derive expressions for the formal
momentum angular momentum and energy of a plane wave in a moving
medium
   /
11096
high frequency diffraction by a wedge with a linearly varying surface
impedance  an asymptotic representation valid both in the illuminated
and shadow regions is derived for the scattered field due to an incident
plane wave and its properties are analysed as a function of the rate
of variation of surface impedance
   /
11097
absorption of electromagnetic radiation by an electron gas  using
the greens function formulation of the many body problem the total
absorption cross section for a photon by an electron gas is calculated
in the high density limit
   /
11098
pulsed x band epr spectrometer  a description of the design and operation
of an electron paramagnetic resonance spectrometer for observation
of spin echoes in the submicrosecond time domain
   /
11099
radio frequency spectrometer with bidirectional square wave frequency
modulation  modulation is effected by means of a voltage controlled
si capacitor coupled to the oscillator tank circuit  if the frequency
deviation is greater than the line width the absorption line will
be displayed with full available intensity and good shape  by careful
adjustment of the relative amplitude of the positive and negative
going deviations incidental amplitude modulation in the rf detector
output component can be eliminated  this method should be applicable
to other types of spectrometers
   /
11100
spectrometer for the frequency range to  the instrument incorporates
a hartley type marginal oscillator with continuous frequency sweep
and frequency modulated at a repetition rate of cs
   /
11101
a stark effect microwave spectrograph with high resolving power
description of a spectrograph incorporating a carcinotron as microwave
source and using stark effect modulation
   /
11102
optical maser characteristics of in
   /
11103
optical maser action of in a barium crown glass  a glass optical
maser using ions and operating at room temperature is described
a number of sharp lines are emitted in a range centred about a
   /
11104
on the resonant frequency modes of ruby optical masers  using a high
resolution spectrograph in conjunction with a fabry perot interferometer
of high resolving power shows the output from an optical maser to
consist of lines  at higher input energies more modes are excited
   /
11105
the kinetics of moving phase boundaries in ferromagnetic ferroelectric
and superconducting materials  the inadequacy of previously published
theories is discussed  a phenomenological model is considered in
which a phase boundary is represented by a thin sheet of the material
in an intermediate state
   /
11106
inverted nature and significance of negative mass landau levels
   /
11107
the magnetic susceptibility of an electron gas  the cluster expansion
of the quantum mechanical grand partition function is obtained for
a gas of interacting charged particles in a uniform magnetic field
and applied to calculate the susceptibility of an electron gas for
small fields
   /
11108
measurement of interplanetary electron density from the earth  radio
astronomy techniques for density measurement in free space the solar
corona and the lunar electron atmosphere are discussed and a solar
wind plasma model is examined
   /
11109
the measurements of random radio frequency fields by the use of short
electric and magnetic dipoles  a note on the relation between measured
noise voltages at the terminals of a short aerial and the temperature
of the radiation field with reference to satellite measurements of
sky brightness of
   /
11110
future large radio telescopes
   /
11111
the australian radio telescope
   /
11112
bursts of centimetre wave emission and the region of origin of x
rays from solar flares  seven solar flare events are discussed  x
ray emission is found to be closely associated with emission less
closely with emission  some implications are considered
   /
11113
the radio emission from normal galaxies  observations of irregular
and early type galaxies at and a general discussion of the results
   /
11114
extragalactic radio emission at  report and discussion of some results
of an interferometer survey of the sky at hobart tasmania
   /
11115
radio emission from cassiopeia on wavelength
   /
11116
time variations of directional cosmic ray intensity at low latitudes
comparison of daily variation of the intensity of cosmic rays incident
from east and west  time variations of east west asymmetry  interpretation
of solar daily variation and changes of east west asymmetry
a report of investigations conducted at ahmedabad during and
   /
11117
on a short lived cosmic ray decrease on november
   /
11118
observations of the van allen radiation regions during august and
september the capetown anomaly and the shape of the outer belt  the
position of the relative minimum in the u outer belt as found by
explorer differs significantly from the position calculated for particles
affected by the capetown anomaly  part of
   /
11119
geomagnetically trapped electrons from cosmic ray albedo neutrons
the energy spectrum for outer belt electrons derived from a neutron
albedo source is calculated the spectrum peaks at whereas rocket
results indicate no such peak  there is fair agreement above  only
the small fraction of electrons above can be accounted for by a neutron
albedo source  the capetown anomaly is found to give only a relative
minimum in the equatorial plane compared with the observed
   /
11120
solar proton impact zones  the trajectories of charged particles
in a magnetic dipole field are calculated numerically and applied
to data on the relative number of impacts in the northern and southern
geomagnetic hemispheres depends strongly on season  low energy protons
are focused into i small impact areas on the earth
   /
11121
supernovae as cosmic ray sources  a theory explaining the origin
of primary cosmic rays is proposed
   /
11122
cosmic ray evidence for a ring current  reduction in cosmic ray cut
offs at minneapolis during the main phase of a magnetic storm is
attributed to a ring current  the data are used to determine the
moment and radius of the ring surface magnetic disturbances are a
function of it is shown that the ring shrinks during the main phase
cosmic ra evidence for a quiet day ring current is discussed
   /
11123
radar observation of venus  observations were carried out by the
radar system using an diameter aerial  the value of the astronomical
unit obtained from these measurements is in satisfactory agreement
with values derived by other observatories see also of january
   /
11124
the determination of the incident flux of radio meteors part sporadic
meteors  the theory relating the radio echo rate to the incident
meteor flux is extended to the case of sporadic meteors  results
for sporadic meteors and several showers are presented  part of
   /
11125
the identification of meteor showers with application to southern
hemisphere results  results of recent radar measurements of meteor
showers at christchurch new zealand are combined with previous visual
and radar surveys to develop a composite picture of meteor activity
seven showers are confirmed appearing in all three surveys another
six to nine are probable being identified in two
   /
11126
radar reflections from the sun at very high frequencies  preliminary
report of measurements made at using a frequency offset keying technique
and transmitted power of  the results complement those obtained earlier
at of
   /
11127
determination of the nature of the earths distant magnetic field
when singly ionized an alkaline earth element such as be is a strong
resonant scatterer of solar radiation  released in a gaseous state
at a distance of earth radii or by atom bomb at about above the magnetic
pole it could be used to mape the geomagnetic field in the vicinity
of the earth
   /
11128
evidence of low frequency hydromagnetic waves in the exosphere  damped
waves with periods of several minutes are found in the auroral zones
since their polarization is essentially elliptical they are interpreted
as low frequency hydromagnetic waves propagated along the magnetic
lines of force
   /
11129
equatorial electrojet in ghana  the variability of the diurnal range
of the vertical magnetic field component observed at tamale ghana
is explained by changes in position and intensity of the electrojet
   /
11130
hydromagnetic interpretation of sudden commencements of magnetic
storms  a model is proposed in which the impact of solar plasma on
the geomagnetic field generates a shock wave  the compressional shock
wave propagates to the earth as a longitudinal hydromagnetic wave
in low latitudes and generates transverse hydromagnetic waves in
the exosphere which propagate to high latitudes along the field lines
a reversed impulse at latitudes above is explained in terms of the
direction of the magnetic perturbation vector at the top of the ionosphere
   /
11131
the magnetic field of a model radiation belt numerically computed
the magnetic field of a model ring current belt is calculated numerically
over the earths surface the field of the ring current is nearly
uniform although the diamagnetism of the belt produces an insignificant
irregularity in the disturbance field in auroral latitudes
   /
11132
scientific research recently carried out by means of veronique rockets
experiments on the physics of the high atmosphere  a report of measurements
made in a recent series of tests  the rocket and associated
telemetry equipment are described
   /
11133
a year of photographic observations of artificial satellites at the
astrophysical observatory of asiago  results of the first years observations
commencing september are tabulated
   /
11134
ionospheric limitations on attainable satellite potential  consideration
of the potentials attainable by a satellite in the ionosphere when
continuous streams and pulsed streams of charged particles are ejected
from it
   /
11135
the motion of an artificial earth satellite in the normal gravitational
field of the earth  mathematical treatment of satellite motion neglecting
air resistance and gravitational anomalies  results can be applied
to the calculation of satellites orbits at high altitudes
   /
11136
analytical approach to the perturbation problem for an artificial
satellite
   /
11137
the effect of atmospheric oblateness on a satellite orbit
   /
11138
the stability of the hour satellite  perturbations of the orbit by
the sun earth and particularly the moon are investigated using a
method of numerical integration
   /
11139
effects of the earths magnetic field on the orbit of a charged satellite
the main effect of the earths magnetic field on a charged satellite
is to cause the node to precess  for the west ford needles the precession
amounts to about
   /
11140
the effects of atmospheric refraction on angles measured from a satellite
   /
11141
electron temperature measurements on the explorer satellite  the
diurnal variation of electron temperature at altitudes of is obtained
from a modified langmuir probe experiment  temperatures range between
and
   /
11142
the canadian defence research board topside sounder satellite  the
satellite is designed to measure the characteristics of the ionosphere
above the region of maximum ionization  it will be placed in a circular
orbit miles above the earth inclined at and precessing westward
the sounder will cover the frequency range in sweeps on command from
ground stations  two telemetry transmitters will operate at frequencies
near
   /
11143
identification of sporadic e from low frequency sweep polarization
records  reversals in the direction of rotation of the polarization
ellipse are interpreted s using the wave theory of reflection from
a thin sharply bounded layer in the ionosphere
   /
11144
the seasonal anomalies in the f region  the seasonal variations in
noon critical frequency and in the occurrence of f layer bifurcation
are ascribed to changes in the electron loss coefficient  these are
related to a seasonal variation in frequency of occurrence of travelling
disturbances and a connection with atmospheric tides is proposed
   /
11145
horizontal diffusion and the geomagnetic anomaly in the equatorial
f region  equations relating to the diffusion of f region ionization
parallel to the earths field are stated and used to discuss low latitude
phenomena  one implication of the analysis is criticized in the adjoining
note which attempts a qualitative description of the role of diffusion
in the equatorial f region
   /
11146
determination of drift movements of the ionosphere at high latitudes
from radio star scintillations  an apparent reversal in drift direction
of the component in three aerial radio scintillation measurements
at tromso is discussed  it can be explained by assuming the diffracting
medium to consist of elongated blobs with the main direction lying
along the projection of the geomagnetic field lines as seen from
the radio source
   /
11147
solar activity effect and diurnal variation in the upper atmosphere
an examination is made of the characteristics of the solar activity
variations in upper atmosphere density and it is suggested that a
source of heating from the solar wind must be involved as well as
solar ultraviolet heating to explain the observed effects
   /
11148
sudden increase in the ionosphere region ionization associated with
solar flares  five v cases are reported in one case the attachment
coefficient was estimated from the ensuing decay  the result was
somewhat higher than the value indicated by ratcliffe
   /
11149
ionospheric currents responsible for sudden commencements observed
at the geomagnetic equator  the height and strength of the line current
which would account for the sc at two equatorial stations is calculated
for storms the height is found to lie between and is independent
of the local time of sc a more realistic sheet current model is examined
and is found to be insensitive to height an explanation of enhanced
at the equator is given
   /
11150
man made heating and ionization of the upper atmosphere
   /
11151
doppler studies of the ionosphere with vertical incidence  a description
is given of a method for determining whether observed doppler shifts
are due to changes in height of reflection or to ionization changes
in the lower ionosphere
   /
11152
polar ionospheric spread echoes and radio frequency properties of
ice shelves  records from three stations in the antarctic and one
drifting stations in the antarctic and one drifting station in the
arctic show that downward radiation from an ionosonde aerial is reflected
from sea water under the ice  an interference pattern is established
from which it is possible to determine the thickness and dielectric
constant of the ice and the direction from which ionospheric spread
echoes arise
   /
11153
a study of the enhanced ionization produced by solar protons during
a polar cap absorption event  the electron density height profiles
produced by solar protons are examined theoretically  the cosmic
noise absorption expected from these profiles are compared with experimental
data  particular attention is paid to the sunrise and sunset
periods  the presence of o alone is insufficient to account for the
observations at these times
   /
11154
polar cap absorption following the solar flare of july  the absorption
records at saskatoon and ottawa during the pca event showed short
term recoveries of the cosmic noise level which were associated with
auroral disturbances  it is suggested that these recoveries were
due to a magnetic screening of the particles causing the pca events
   /
11155
minor pca events during march  two polar cap absorption events are
described in detail
   /
11156
interrelations among the upper atmosphere disturbance phenomena in
the auroral zone  an analysis of data from syowa station antarctica
reveals a numerical relation between the intensity of the line the
maximum electron density of ionization and the magnitude of the horizontal
disturbance vector
   /
11157
ionosphere review  a comment on ionospheric conditions including
a note on probable sunspot activity up to the end of with special
reference to effects on long distance communication
   /
11158
lunar time variation of oxygen green line in the night airglow  it
is suggested that the lunar time variation in the intensity of the
line is due to the tidal influence on the density of oxygen atoms
near the level
   /
11159
collision processes in the aurorae and ionization in the auroral
zone  a review of present knowledge which includes the stopping power
of air the charge changing in proton beams and ionization processes
   /
11160
rocket measurements of auroral radio absorption  the variation of
ionospheric absorption with height was studied by measuring the signal
strength of a transmission from the ground  the results from a flight
on october indicated that most of the absorption occurred between
and th peak being in the region
   /
11161
direct measurement of charged particles associated with auroral zone
radio absorption  rocket observations of electrons with energy and
protons with energy are described  during ascent the electron flux
showed large and rapid fluctuations which are consistent with a columnar
structure while the proton intensity was relatively steady  an estimate
is made of the integral electron energy spectrum and the angular
distribution of both electrons and protons are examined
   /
11162
whistler dispersions for a model of the ionic distribution in the
exosphere  an investigation into the dispersion of whistlers for
a range of exospheric temperature latitude and ion content
   /
11163
theory of stochastic linear systems with gaussian parameter variations
a theory of linear systems with randomly varying parameters id is
developed under the assumption that the parameter processes are gaussian
processes obtained by linear filtering of white noise  a theory of
mean and mean square stability is given and applied to an circuit
with randomly varying capacitance  an error in a previous analysis
is corrected
   /
11164
high stability temperature controller for transistors  the control
system uses two servomechanism stages which are electrically independent
but thermally in series an outer annular block is made to provide
initial temperature control of the inner block which is thermally
stabilized within itself
   /
11165
single turn recording heads  results of an experimental approach
to the development of a single turn head for a magnetic drum storage
system are noted  optimum values of drum plating thickness gap width
and write current are shown in gtaphs
   /
11166
voltage stabilization by means of trigger tubes  several cold cathode
trigger tube circuits are described which give effective stabilization
against fluctuating input voltage and current drain
   /
11167
the dsk system of fuel cell electrodes  a description of various
cells which have been constructed and experimental results
   /
11168
the pascal a fast digital electronic computer for the philips computing
centre  a description of the design and operation of the computer
which is a binary parallel machine of single address type with a
word length of bits  it incorporates five different kinds of storage
system including special plug board and modification units
   /
11169
the rectangular loop ferrite core as storage device for data processing
installations  outline of principles underlying the storage mechanism
and magnetization reversal process with details of typical characteristics
and dimensions of cores for use as storage elements
   /
11170
magnetic film rods provide high speed memory  the application of
rod elements of in the development of a word bit per word storage
system with a cycle rate is described
   /
11171
planar transistors in microwatt logic circuitry  the application
of the uhf si transistor to logic circuits at very low power is discussed
a four stage shift register is described which operates at per
transistor stage
   /
11172
pattern recognition  review of the principles of pattern recognition
on the basis of information theory  references
   /
11173
printed circuits made without drawings  a ring matrix technique is
described for rapid production in the laboratory of a circuit negative
which is readily modified
   /
11174
the helitran  two designs of rf transformer with continuously variable
turns ratio forming a nearly perfect voltage divider are described
a helitran can simplify the design of the variable conductance control
of three terminal bridges with a transformer ratio arm
   /
11175
coil capacitances and inductances of single layer cylindrical coils
for different current voltage distributions over the coil
   /
11176
possibilities of realizing logic boolean functions by means of rectangular
magnetic networks  the network consists of idealized transfluxors
with rectangular hysteresis loop
   /
11177
using hall generators as contactless commutators  a sampling rate
in excess of is achieved by feeding a signal voltage into one input
of a hall generator and a switching waveform into the other  amplification
must be used to recover the signal loss but only one amplifier
is needed regardless of the number of inputs
   /
11178
designing tunnel diode circuits using composite characteristics
with tunnel diodes connected in series certain relations between
their peak and valley currents and their final voltages can be satisfied
so that the composite curve has peaks valleys and stable positive
regions  the use of this type of characteristic for binary addition
scaling and encoding is described
   /
11179
solid state optoelectronic commutator  matching electroluminescent
photoconductor arrays can be packed into a volume per switching element
the noise from an eight channel binary output commutator is bandwidth
compared with an upper signal limit of
   /
11180
the edge effect of a capacitor of finitely thick plates with application
to magnet design  conformal mapping is used to determine exactly
the fringe capacitance and field strength distribution of a thick
plate capacitor  general formulae and curves are given  the application
to magnet systems intended for high frequency devices is described
   /
11181
novel microwave resonator  a cavity resonator designed at the national
bureau of standards based on fabry perot interferometer technique
consists of two perforated sheets of meta square forming the ends
of a box  microwave energy beamed on one end with correct end spacing
produces a resonance q of about
   /
11182
symmetric quadripoles  further detailed description of the transformation
of symmetric quadripoles and the cascade connection of bridge
circuits to form filters
   /
11183
analysis and synthesis of antimetrical networks  an extension of
previous work on symmetrical reactance networks of to reactive ladders
with resistance terminations
   /
11184
a realization of the error curve system  the filter analysed by of
is discussed in terms of kupfmullers system theory
   /
11185
transfer characteristics of electromechanical coupling filters as
a function of the coupling element  the effect of manufacturing tolerances
to respect of diameter and length of mechanical transmission
line elements is investigated
   /
11186
a contribution to the synthesis of resistive three ports  algebraic
and topological treatment of a special case of three port network
synthesis  for italian version
   /
11187
fundamentals of linear graphs and their applications to networks
without transformers  the application of linear graph theory to the
analysis and synthesis of passive networks ad matrix methods of
solution are described
   /
11188
the switching on of two oscillator circuits which are coupled by
an externally controlled reactance case of the parametric amplifier
extension of earlier investigations of february to the case of coupled
resonant circuits
   /
11189
investigation of the possibilities of a nonreactive parallel connection
of two oscillators in the short wave range  scattering matrices are
used to calculate the characteristics of three and four port networks
and a comparison of their suitability for parallel connection is
made  application to waveguide circuits is discussed
   /
11190
defining the coherence of a signal
   /
11191
an analysis of a class of variable frequency sinusoidal oscillators
using a single active element  an analysis is given of a class of
oscillators requiring a single active element with an electronically
variable mutual conductance  the oscillation frequency is directly
or inversely proportional to  two experimental circuits are described
and compared with theory
   /
11192
an investigation of nonlinear distortion in grid modulated oscillators
caused by the bottom bend of the static valve characteristic
   /
11193
review of the present state of crystal control and frequency synthesis
description of basic circuits constituting various frequency synthesizing
systems
   /
11194
one tunnel diode flip flop  report on the operation of a circuit
similar to one given in with oscillograms showing triggering and
switching modes
   /
11195
an astable four region multivibrator  the multivibrator operation
of a four region semiconductor structure is analysed and its temperature
instability is discussed  results obtained with a five region structure
are also given
   /
11196
pulse compression without dispersive networks  pulse compression
by means of a three dimensional correlator using light modulation
is described  the application to radar systems is discussed
   /
11197
saturation effects in ferrite frequency doublers operating in the
uniform precession mode  three distinct saturation mechanisms occurring
in ferrite frequency doublers are described  an approximate nonlinear
equation of motion including the effect of the reaction field is
obtained and solved for a particular case
   /
11198
a variable ultrasonic electro optical delay line and a new ultrasonic
optical effect in fused quartz  a variable delay line for rf pulses
is described in which unpolarized light is modulated by the rf signal
passing through a quartz bar and is detected by a photomultiplier
the operation of the system is unexplained
   /
11199
quartz delay lines the state of the art  a summary of available information
on geometry performance ad applications of ultrasonic delay
lines
   /
11200
transient phenomena in ruby maser  a note on time lags observed in
the build up of oscillations in a pulsed three level maser operating
at with pump frequency
   /
11201
on the problem of pulsed oscillations in ruby masers  the nonlinearity
necessary for the existence of a pulsed mode of operation is shown
to be due to the interaction between the electrons and the distant
nuclei
   /
11202
double beam masers as primary frequency standards
   /
11203
origin of noise in a ferromagnetic parametric amplifier  further
measurements on a ferromagnetic parametric amplifier with longitudinal
pumping indicate that the exceptionally high noise figure previously
reported is not thermal in origin
   /
11204
an extremely low noise nondegenerate parametric amplifier  preliminary
note on an experimental amplifier which was operated at room and
liquid nitrogen temperatures  a system noise temperature was achieved
   /
11205
microwave carrier modulation demodulation amplifiers and logic circuits
applications of parametric amplifiers are described in wide band
video modulation demodulation amplifiers and ultra high speed logic
circuits with possible repetition rates of the order of
   /
11206
the tunnel diode superregenerative amplifier  the simplicity of the
circuitry required and the characteristics of tunnel diodes make
superregenerative amplifiers very attractive for applications where
high gains are required  the noise performance of maser and parametric
amplifiers is superior
   /
11207
progress in field emission work function measurements of atomically
perfect crystal planes
   /
11208
the penetration of an electron beam through a plasma part general
considerations amplifications and overstability  the problem is treated
from the point of view of the double stream amplifier the resistive
and inductive envelope amplifier and stability theory
   /
11209
the orbit of a charged particle in a constant magnetic field and
a sinusoidal electric field  explicit expressions are obtained for
the particle orbit assuming that the effect of the electric field
on the particle is merely to produce a perturbation on the motion
which it would describe in the absence of th  field
   /
11210
experimental demonstration of the phase shift of electron waves by
the magnetic vector potential  report on investigations with an electron
optical interferometer  see also of
   /
11211
the noise temperature of a plasma  using a current source method
an expression for noise temperature is derived identical with that
for plasma radiation temperature derived by bekefi et al but valid
under more general assumptions  the application of the expression
is not confined to transparent plasmas
   /
11212
dielectric constant of plasma  the definition of dielectric constant
used by gallop et al is criticized on theoretical grounds  in reply
the authors point out that the definition is justified on experimental
evidence relating to the particular conditions under discussion
   /
11213
emission absorption and conductivity of a fully ionized gas at radio
frequencies  classical and quantum mechanical calculations are compared
yielding the emission spectrum of free electrons in the coulomb field
of positive ions
   /
11214
backward waves on isotropic plasma slabs  if the relative dielectric
constant of the plasma becomes negative backward surface waves can
be developed on a lossless homogeneous and isotropic plasma slab
   /
11215
magnetic effects in a plasma column irradiated with microwaves  the
radius of gyration of a plasma column is determined by imparting
a coherent circular orbital motion to the electrons in the column
at its principal resonance frequency  this is accomplished by irradiating
the column with two incoming waves of the same frequency but out
of phase  when the electric fields are correctly aligned a magnetic
moment is developed
   /
11216
magneto fluid dynamics  papers presented at the symposium sponsored
by the international union at theoretical and applied mechanics in
co operation with the national academy of sciences and te the national
research council held at williamsbug virginia and washington dc in
january of
   /
11217
the propagation of slow electromagnetic waves in plasma cable  a
phase difference method of measurement is described which enables
the propagation parameters of a travelling wave in a plasma to be
determined  including the direction of phase and group velocities
   /
11218
on the axial echo area of the cone sphere shape  initial results
of a study of the back scattering from a cone sphere are given  comparison
is made between the measured and calculated axial echo areas
of a cone sphere
   /
11219
two magnon processes in ferromagnetic relaxation  a theory is developed
from the assumption that all magnons of equal energy are so tightly
coupled that they may be considered as a unit in any process involving
degenerate magnons
   /
11220
propagation of spin waves  theoretical considerations show that coherent
spin wates can be propagated in a ferrite material if the microwave
field penetrates no more than a distance into the specimen
   /
11221
infrared oscillations from and masers  results obtained from the
operation of these masers are given  trains of damped oscillations
were observed
   /
11222
continuous operation of the p optical maser  preliminary report on
the experimental apparatus and results achieved  continuous operation
was maintained for about
   /
11223
lasers  review of recent developments and applications
   /
11224
theory of relaxation oscillations in optical masers  a theoretical
explanation is given of the intense short spikes observed in the
output of optical masers of a simple formula is derived for the time
interval between them and the rate at which they decay to a constant
level
   /
11225
visual display of isolated optical resonator modes in a laser cavity
is described  two concave mirrors forming a nearly spherical cavity
are used
   /
11226
coupling of laser rods  interference was observed between the oscillations
produced in two parallel ruby laser rods coupled by a prism
results indicate that the coupling of independently pumped lasers
is feasible
   /
11227
measurements of the laser output  measurements of energy output were
made by means of a simulated black body absorber the accuracy of
the system was sufficient to measure a minimum energy of joules
a plot of laser output as a function of pump input energy is reproduced
   /
11228
propagation in laser crystals  an example is given of ring structure
in a far field pattern from a laser  this may be absent but fringes
may still be obtainable from a two slit system
   /
11229
stimulated light emission by optical pumping and by energy transfer
in organic molecules  observations of stimulated light emission in
organic glass matrices are described particularly in glass containing
ap approximately of benzophenone and of naphthalene in which energy
is absorbed by the naphthalene in which energy is absorbed by the
benzophenone and transferred to the naphthalene
   /
11230
optical mixing  a report of the observation of the sum frequency
of two ruby laser beams of different frequencies in the region incident
simultaneously on a crystal of triglycine sulphate
   /
11231
mixing of light beams in crystals  plane light waves provided by
an intense unfocused beam of a ruby laser are used to produce second
harmonic radiation in a kdp crystal
   /
11232
effects of dispersion and focusing on the production of optical harmonics
the generation of blue light by the incidence of red light from
a ruby laser upon quartz and kdp is examined  particular attention
is giten to the variation in blue light intensity with crystal orientation
   /
11233
nonlinear optical effects  the possibility is discussed of producing
harmonic generation and mixing at infrared and visible frequencies
by means of radiation from optical masers
   /
11234
some radio astronomy techniques  a review of modern techniques
   /
11235
spectral observations of solar radio bursts slow drift bursts and
coronal streamers  the characteristics and origin of slow drift bursts
spectral type are determined from data recorded in the frequency
ranges and at fort davis texas during the pr period october december
the equipment used is described in part
   /
11236
mechanism of cosmic ray storms inferred from some statistical results
a statistical analysis of results obtained during a four year period
including the igy relating to the propagation time of cosmic ray
storms and the heliographic position of solar flares
   /
11237
the day period of cosmic radiation  the existence of a persistent
day periodicity of the intensity of cosmic radiation is proved from
an analysis of recordings at huancayo peru and halle germany
   /
11238
trapped proton and cosmic ray albedo neutron fluxes  a rocket borne
emulsion stack was launched at to an altitude of a proton energy
spectrum above was calculated and its shape near interpreted by assuming
a minimum in the cosmic ray albedo neutron spectrum
   /
11239
absolute electron intensities in the heart of the earths outer radiation
zone  previous estimates from geiger counters of the electron flux
above are shown to be too large by a factor of  the high count rates
are due not to electron bremsstrahlung but to directly penetrating
electrons of energy
   /
11240
time variations of the energy spectrum of solar cosmic rays in relation
to the radiation hazard in space  results from a number of solar
cosmic ray events are used to estimate the highest level of integrated
proton flux likely to be encountered
   /
11241
particle motion in the equatorial plane of a dipole magnetic field
for the motion of a high energy particle in a dipole field a correction
to the usual drift velocity is given the new result must be used when
the radius of gyration of the particle approaches the scale of the
field
   /
11242
ionized gas and fast electrons in the vicinity of the earth and in
interplanetary space  measurements made during the flight of the
second soviet space rocket are described  it is concluded that the
electron flux in the second radiation belt does not exceed  evidence
is also provided for the existence of a third outermost belt from
the earths surface
   /
11243
observations of the van allen radiation regions during august and
september part the inner belt  ionization chamber and gm counter
data from explorer are used to obtain the two constants in an assumed
energy spectrum for inner belt protons of the form electron fluxes
of low energy are estimated from scintillation counts
   /
11244
the detection of electrons with energies of approximately in the
upper atmosphere  fluorescent sreen indicators on the third soviet
satellite recorded electron fluxes at altitudes up to over the southern
region of the pacific ocean  the depence of electron and energy fluxes
on direction relative to the earths field is examined  it is suggested
that the energy flux is sufficient to cause heating in the f region
   /
11245
bifurcation of the outer van allen belt and related auroral phenomena
the two parts of the outer r belt are associated with two separate
regions of auroral activity
   /
11246
irregular lunar reflection polarization changes noted in the presence
of aurora  observations made during a lunar experiment carried out
between sagamore hill and jodrell bank show fast irregular changes
in signal polarization while a visible aurora occurred on one leg
of the bistatic path  an explanation is given
   /
11247
a new technique for investigation of meteor echoes at uhf  the application
of radar doppler measurements to the study of meteor echo characteristics
is described
   /
11248
solar protons and particles from the september a report of balloon
observations at minneapolis during a series of major solar flares
   /
11249
on the frequency of occurrence and amplitude spectrum of the geomagnetic
field pulsations  the results of investigations of geomagnetic micropulsations
observed at the soviet flux measurement stations during are
presented  diurnal variations of amplitude and of frequency of occurrence
of micropulsations having different periods are investigated
   /
11250
theoretical determination of the form of the boundary of the solar
corpuscular stream produced by interaction with the magnetic dipole
field of the earth
   /
11251
new experimental evidence of the effect of magnetic storms on the
magnetosphere  new methods of whistler analysis of have been used
to study the effect of magnetic storms on the time delay at whistler
nose frequencies  during the late phases of magnetic storms these
time delays are reduced  there is evidence that these changes in
delay represent changes in the electron density in the magnetosphere
   /
11252
the first italian launch of a sounding rocket for atmosphere research
review of technical problems and the organization and equipment employed
for a sodium cloud experiment carried out from sardinia on january
results are given and discussed
   /
11253
the classification of the motions of an artificial earth satellite
about its centre of mass  an analysis is given of aerodynamic and
gravitational perturbations taking account of orbital repression
the aerodynamic effects due to retardation of the satellite rotation
are not considered
   /
11254
on the secular variations of the elements of satellite orbits
   /
11255
on the long period effects in the motion of an artificial satellite
caused by the ellipticity of the earth  effect of ellipticity of
the equator on hour nearly circular satellite orbits
   /
11256
predicting the lifetimes of artifical satellites in theory and practice
possible errors involved in calculating life times from simplified
formulae are considered and methods of error reduction are suggested
   /
11257
preliminary results f of radiation measurements from the tiros meteorological
satellite  measurements of visible and infrared radiation
are pree presented together with television pictures of cloud patterns
values of radiation fluxes and albedos are derived
   /
11258
use of z mode propagation for observing cosmic radio noise from earth
satellites  the use of z mode propagation for reception of signals
from satellites above the height of maximum ionization density gives
an effective improvement in angular resolution stability of radiation
pattern and pencil beam configuration
   /
11259
energy detector for satellites  a description of a detector used
in explorer and inun to measure the integrated energy flux of low
energy electrons and protons
   /
11260
electron temperature evidence for nonthermal equilibrium in the ionosphere
measurements of ion density and electron temperature from four
rocket flights by dumb bell shaped johnson malter type probes are
presented  the method of analysis is described in detail with examples
electron temperatures about double the gas temperatures were found
from to
   /
11261
electron distribution in the ionosphere over trivandrum  the results
are given of a analysis of profiles obtained from records on selected
quiet days during june september
   /
11262
the behaviour of the lower ionosphere near sunrise  in the lower
d region a temporary increase in electron density is predicted at
the time of ionospheric sunrise  a decrease in the height of reflection
of clf waves and a decrease in the signal strength of waves at sunrise
are quoted as evidence for the existence of the temporary layer
   /
11263
the determination of d region electron densities from observations
of cross modulations  the bailey and martin expressions for cross
modulation are not sufficiently accurate new expressions have been
derived and used to determine d region electron densities  near sunrise
a nearly uniform layer is created almost simultaneously between and
there are no striking changes during the rest of the day
   /
11264
ionospheric effects associated with the solar flare of september
   /
11265
effects of nuclear explosions on the ionosphere  an increase of about
in the electron density of the f layer over lindau was observed at
the time of transit of the shock wave from the megaton yield nuclear
bomb over novaya zemlya on october  relevant ionograms and data are
illustrated
   /
11266
the relation of magnetic micropulsations to electric current and
space charge systems in the lower ionosphere  from observations made
in using a large wire loop theory is developed to suggest that micropulsations
in the range are associated with absorption of auroral particles
in the ionosphere and in the range are the result of the absorption
and reflection of hydromagnetic waves in the lower ionosphere
   /
11267
total electron content of the ionosphere over singapore during a
magnetic disturbance  observations made during a disturbance characterized
by a negative phase show a corresponding decrease in total electron
content of the ionosphere
   /
11268
spread f and geomagnetic activity  on magnetically quiet days the
occurrence of spread f at trivandrum near the geomagnetic equator
is regular it begins after sunset reaches a peak at and falls off
slowly towards morning  on stormy days the frequency of occurrence
is lower and the behaviour is less regular  the effect of storms
is least in summer  some of the observations are in agreement with
the theory of martyn
   /
11269
rocket measurement of the upper ionosphere by a radio propagation
technique  an example of measurement of the electron density profile
up to by means of the tso two frequency technique is presented including
the determination of inferred scale height and temperature of the
upper ionosphere  a correction procedure is outlined necessary for
the determination of local electron density data
   /
11270
diurnal variations in the ionosphere deduced from satellite radio
signals  observations of the faraday fading rate at sydney australia
from have been used in a simple way to obtain diurnal and seasonal
electron content variations  secondary maxima occur at in both seasons
and in winter the diurnal variation in winter is several times greater
than the summer variation  these values are compared with the variations
in
   /
11271
quality control of ionograms  description of an instrument for making
quick accurate checks of receiver and display characteristics
   /
11272
some observations of ionospheric absorption at geomagnetic conjugate
stations in the auroral zone  the boundary of the polar cap absorption
regin appears to extend to the same effective magnetic latitude in
the northern and southern hemispheres  during auroral events the
absorption generally occurs simultaneously at the nearly magnetically
conjugate stations of farewell and campbell island
   /
11273
world maps of  contour maps based on local time and diurnal variation
showing the percentage of have been constructed from ionospheric
datz data obtained during
   /
11274
the electron density distribution above the peak and associated atmospheric
parameters  theoretical models of electron and ion distributions
are discussed
   /
11275
upper atmosphere helium ions  available data are consistent with
an atmospheric model in which a layer of helium ions at least thick
separates the ionosphere from the protonosphere
   /
11276
a correction to the exospheric electron density estimate using the
nose whistlers of march  a reinterpretation of the data gives electron
densities about four times larger than those previously deduced
   /
11277
on the orientation of auroral arcs  the diurnal variation in the
direction of quiet arcs at kiruna is similar to the theoretical variation
expected r from alvens theory  the average arc direction near
the auroral zone seems to be determined for a given time by projections
of circles in the geomagnetic equatorial plane on to the earths surface
along the geomagnetic field lines
   /
11278
the morphology of the auroral displays of parts a study is made of
all sky camera records from a network of stations in alaska and from
an array of stations extending from sub auroral latitudes to near
the geomagnetic pole  the subjects considered include the time and
latitude dependence of incidence azimuthal alignment direction of
horizontal movement of auroral forms and the relation of these subjects
to magnetic disturbance
   /
11279
argus radar returns in conjugate area  the concept of orthogonal
reflection from aurora and field aligned ionization is used to explain
the apparent movement of the radar returns
   /
11280
west east motion of an auroral zone x ray event  a west east motion
of an auroral zone x ray event was observed late in the magnetic
storm of june time delays between x ray burst at balloon altitude
and increases in ionospheric absorption of cosmic radio noise indicate
that velocity components along the auroral zone of are present in
this type of event
   /
11281
midnight fall in atmospherics activity on band at poona  on of nights
there is a fall in activity which is explained in terms of a sudden
decrease in the number of sources of atmospherics which occurs when
the evening peak in thunderstorm activity crosses the west coast
of africa  the fall is greater during magnetically disturbed periods
   /
11282
dispersion of whistlers  the whistler dispersion d is found to have
diurnal and seasonal variations  the seasonal variation depends on
geomagnetic latitude  variations of d with geomagnetic and solar
activity are also discussed
   /
11283
whistlers and solar activity  a high negative correlation between
whistler activity and sunspot number has been found for the years
in japan
   /
11284
recording of electrical signals of particularly low frequency during
the solar eclipse of february  recordings of atmospherics in the
range observed at bonn and munich at the time of the eclipse are
reproduced  the characteristics immediately after the eclipse are
similar to those normally obtained at sunrise
   /
11285
variation of the dispersion of radio whistlers during magnetic storms
the whistler dispersion shows a special decrease at poitiers after
the commencement of an intense magnetic storm  the decrease is not
observed for lesser storms  this is possibly due to the existence
of favoured paths which move to lower latitudes as the storm intensity
increases
   /
11286
a possibility of the generation of vlf emissions in the earths outer
exosphere
   /
11287
investigation of the magnetic recording process with step functions
   /
11288
ht supply units for television receivers equipped with silicon diodes
a short survey of semiconductor rectifiers is given and design parameters
for rectifier circuits and rc smoothing networks are discussed
   /
11289
an explanation of the superior radiation resistance resistance of
type base si solar cells  calculation of the effect of electron flux
on the minority carrier lifetime in the base region gives results
which agree well with measurements of actual damage
   /
11290
current limited rectifiers  a description is given of a class of
rectifier circuits that limit their output current to a specified
maximum  applications are suggested
   /
11291
heat to ac conversion using thermoelectric generators and tunnel
diodes  single cell generators operating between and produce of electric
power  the dc output of at is converted to high voltage power by
using a high current tunnel diode as a dc ac converter
   /
11292
an electroluminescent fixed store for a digital computer  a method
of reading information from such a store is discussed and the operation
of a matrix containing digit positions is described
   /
11293
circuit protection for a transistorized magnetic core memory  the
system protects the storage elements against fault currents as low
as even though the normal operating current is
   /
11294
minimum size and maximum packing density of nonredundant semiconductor
devices  the essential active region in semiconductor devices is
already close to minimum size  further miniaturization of these devices
must come from reduction in the size of nonessential parts
   /
11295
modular circuit construction  circuits are constructed on a wiring
board consisting of a laminated base board pierced with a regular
matrix of holes  see also of
   /
11296
some considerations on s square loop magnetic core circuits  domain
wall motion theory is introduced to correct the simple analysis for
determining the driving impedance of a ferrite core  the results
for peak output voltage are not changed by using the domain theory
   /
11297
force free coils and superconductors  a discussion of the prospects
of building superconducting high field coils based on a force free
construction technique which are suitable for operation in the range
   /
11298
superconducting solenoids  graphs are presented wit which permit
the application of a method based on the fabry formulation for the
approximate optimization of superconducting solenoids
   /
11299
a sequence switching unit for measurement of ionospheric drift
   /
11300
switching elements consisting of photoconductors and triggered neon
lamps  the properties of combinations of photoconductors with normal
and triggered neon lamps are discussed  some requirements of the
lamp characteristics are given
   /
11301
circuit designers improve practical applications of solid state devices
a review of some of the low noise amplifiers and microwave power
sources using solid state masers tunnel diodes and varactors featured
at the solid state circuits conference philadelphia
   /
11302
theoretical analysis of an inter digital resonator with radial vanes
general expressions are derived for calculating to successively better
approximations the resonant frequencies of modes perturbed by the
vanes and anode  examples of calculations are verified experimentally
   /
11303
lumped impedance network transformation  given the mz matrix of a
network having pairs of terminals an equivalent network involving
transmission lines with junction points is discussed
   /
11304
on the network with the minimum number of coils  necessary and sufficient
conditions for maximizing the degrees of freedom of an network
which contains a given number of inductances and resistances and
an arbitrary number of capacitances are established  a method of
determining the transfer function of a tchebycheff type band pass
filter with a minimum number of coils id described
   /
11305
the reduction of unsymmetric quadripoles between different terminal
resistances to symmetric quadripoles
   /
11306
the calculation of build up processes in networks with stagger tuned
individual circuits and large relative bandwidths  the response to
switching on transients of two and three stage networks is calculated
   /
11307
terminal impedance and gain of the series to parallel transitionally
coupled circuit
   /
11308
a study of the phase and filter properties of arrays of parallel
conductors between ground planes
   /
11309
crystal filter design  a universal design graph gives filter characteristics
of any quartz unit and termination  the technique described
is specially suitable for multi channel applications
   /
11310
theory and examples of application of a circuit element with distributed
resistance and distributed capacitance  the component considered
consists of a ceramic plate of high dielectric constant with a resistive
coating on one side and a highly conductive coating on the other
side  this circuit element is equivalent to an infinite number of
cascade connected filter sections  applications discussed include
a low pass and a rejection filter and a frequency control element
for an oscillator
   /
11311
low q band pass filters  a lossless filter design is modified to
preserve the relative discrimination between a wanted frequency and
an unwated band when the filter elements are lossy
   /
11312
variable pass a band rc filter
   /
11313
jaumann structures with capacitive tapping for band pass crystal
filters  symmetric and dissymmetric capacitive tapping of a band
pass filter transformer is considered and a method of obtaining a
maximum capacitance ratio in the branch to be replaced by a crystal
is developed
   /
11314
the influence of the differential transformer on the attenuation characteristic
of differential bridge filters
   /
11315
duality of nonplanar electric circuits without the use of ideal transformers
a method of constructing the dual of any linear lumped nonplanar
network which does not include magnetic coupling is given without
using ideal transformers
   /
11316
a hall effect microwave mixer  a signal frequency current and a magnetic
field at the local oscillator frequency produce a hall effect emf
at the if across a semiconducting plate  the minimum conversion loss
achieved is
   /
11317
a survey of very low frequency oscillators  methods of generating
frequencies below for vibration work and for testing servomechanisms
are outlined  the major characteristics of instruments are tabulated
   /
11318
a high stability transistor oscillator for  the design development
construction and testing of a oscillator are described  power output
is stable within and frequency within ove  the temperature range
   /
11319
spikes on chopper transistor waveforms  the effect of load resistance
and capacitance on spike feed through is investigated and the amplitude
and rise and fall times are derived  a spike test for chopper transistors
is recommended
   /
11320
avalanche pulse generators  a method is given for optimizing the
switching time and the pulse repetition rate of avalanche transistor
operation
   /
11321
a fast counter for adding and subtracting randomly related pulse
trains  the circuits shown have a high speed of count propagation
through a binary or binary decimal counter and are able to deal with
random pulses on each line irrespective of the degree overlap or
separation of the pulses
   /
11322
pulse counting and fast scaling transistor circuits  a review of
scaling circuits and some typical designs
   /
11323
millimetre wave harmonic generation in ferrites  a ferroxcube doubler
driven at a fundamental of was found to have a minimum conversion
loss of when the output waveguide was polarized parallel to the input
   /
11324
microwave harmonic generator capable of frequencies in excess of
the device contains argon at atmospheres which reduces the are produced
between cathode and anode to a small cathode spot  the microwave
signal driving the arc is a continuous wave of about  an output of
at the harmonic of the drive input is obtained
   /
11325
gain and in phase suppression of symmetric and unsymmetric differential
amplifiers  the equivalent circuit of the differential amplifier
is given and the operating parameters are calculated
   /
11326
transistor differential amplifier  the design concepts of and experimental
results obtained from a drift compensated cross coupled amplifier
are discussed
   /
11327
thermal feedback in a dc transistor amplifier  thermal feedback is
applied via resistance windings around two transistors of a balanced
input stage  it is only effective at very low frequency and it reduces
dc drift  experimental results are given
   /
11328
optical pumping of masers using laser output  using ruby with a total
ion concentration of about an inversion of approximately between
levels and and for several hundreds of microseconds is predicted
which should give stimulated emission at  apparatus is being made
to demonstrate this
   /
11329
reduction of the noise figure of an amplifier by a negative conductance
in its input circuit  the lowest noise figure is obtained when the
negative conductance is infinitely great  in practice a minimum noise
figure exists only if the lowest permissible value of stability or
bandwidth is given
   /
11330
quasi cascaded parametric amplifier  a description is given of a
circuit based on the resonance modes of a single sample which should
significantly improve the power gain of current suhl type amplifiers
   /
11331
parametric energy conversion by nonlinear admittances  circuits employing
nonlinear resistances and capacitances are described which can
yield unconditionally stable up conversion gains considerably in
excess of the output input frequency ratios  the down conversion
loss can be made simultaneously high
   /
11332
broad band parametric amplifiers by simple experimental techniques
maximum use is made of the parasitic elements of the varactor diode
and simple measurements enable the diode unit with the best characteristics
to be chosen  the pass band characteristics of diode mount combinations
are also measured  single channel gain band width products
approaching have been achieved
   /
11333
nondegenerate x band amplifier  the parametric amplifier described
uses a pill varactor diode it has a gain of and a noise figure of
with more pump power greater gains should be relizable at bandwidths
equal to or slightly less than
   /
11334
the efficiency of electrostatic quadrupole amplifiers
   /
11335
parametric amplifier improves troposcatter system  design details
are given of an amplifier operating at which improves the performance
of an existing communications receiver
   /
11336
tunnel diode straight amplifier as low noise preamplifier stage for
the uhf range  the signal and noise characteristics are investigated
of a conventional triode amplifier with a tunnel diode circuit as
preamplifier stage and experimental results obtained at and are found
to agree well with theory  for similar investigations on a diode
reactance preamplifier see
   /
11337
the problem of nonlinear signal distortion in ring modulators  theoretical
and experimental investigation particularly of third order distortion
   /
11338
self reactance modulation in telemetry oscillators  design formulae
are given for predicting the frequency characteristics of vhf and
uhf transistor oscillators
   /
11339
microwave modulation of light using the kerr effect  modulation of
light at and is achieved by applying a superimposed and microwave
field to a kerr cell which is incorporated within the high electric
field region of a resonant cavity
   /
11340
drift mobility of an ionic impurity in an electric field
   /
11341
on the theory of surface states  a new method is proposed for calculating
shockley type surface states
   /
11342
thermoelectric phenomena associated with electron field emission
the equilibrium temperature distribution in an ideal metal rod one
end of which is subjected to an intense electric field is studied
the application of the system as a heat pump is considered
   /
11343
an analytical solution for the effect of space charge in cold cathode
gas discharges  by using a simple mathematical model an analytical
solution for the varney space charge equation is obtained  this is
in good agreement with the exact solutions computed by ward
   /
11344
current build up in neon gas discharges at small overvoltages  the
increase is exponential the time constant is calculated theoretically
assuming that the discharge is sustained by secondary emission from
the cathode caused by ions and metaastable ne atoms  there is good
agreement with experiment
   /
11345
perturbation of electron flow  a perturbation analysis of single
stream quasi static non relativistic electron flow is developed based
on the nonlinear equation for the velocity field
   /
11346
the frequency of nonlinear plasma oscillations  the frequency of
plane standing waves of electrons moving through a back ground of
infinitely heavy ions is independent of amplitude if the electron
velocity is a unique function of position  this is not true for spherical
and cylindrical plasma oscillations
   /
11347
wave propagation in a partially ionized medium  theoretical treatment
of the propagation and damping of low frequency waves in an infinite
uniform partially ionized medium in a longitudinal magnetic field
tso two longitudinal modes one an acoustic wave and two transverse
uncoupled modes are identified
   /
11348
demonstration of classical plasma behaviour in a transverse magnetic
field  a demonstration that the removal of the internal electric
field halts the streaming of the plasma transverse to the b field
   /
11349
notes on the effect of noise on langmuir probe characteristics  the
effects of periodic fluctuations of electron temperature random current
and space potential are considered  in many cases the electron concentration
will be underestimated
   /
11350
x band measurement of shock tube plasma temperature  the radiation
temperature of a plasma behind a hypersonic shock wave is measured
using a microwave receiver  results indicate that the temperature
is approximately
   /
11351
resonances of a microwave cavity partially filled with a plasma
the resonance characteristics of a cavity containing a cold plasma
of arbitrarily large density are studied theoretically and experimentally
in addition to the modes of an empty cavity a new class of modes
is found
   /
11352
possible sources of energy of ion oscillations in high and ultra
high vacuum  two mechanisms are proposed to account for plasma oscillations
arising in electron beam amplifier devices
   /
11353
theory of ferromagnetism and the ordering of electronic energy leve
s  the ordering of the energy levels of a system of interacting fermions
is considered mathematically
   /
11354
stability of one dimensional ferromagnetic microstructures  all nonuniform
one dimensional structures are found to be unstable reasons for
the stability of three dimensional structures are given
   /
11355
magnetic decay in a hollow circular cylinder  the rate of decay is
found t depend on a dimensionless constant which is a function of
the inner radius and outer radius of the cylinder  numerical values
of have been computed for various ratios
   /
11356
propagation of a plane electromagnetic wave in a plasma at cut off
and beyond  a complete solution of maxwells equations for two typical
density distributions is used to demonstrate the limitations of the
geometrical optics hypotheses for thin plasmas
   /
11357
the influence of positive ions on the propagation of electromagnetic
waves in magnetized plasmas  theoretical investigations covering
a wide range of frequencies up to gyro frequency for the case of
a homogeneous infinite plasma and a plasma confined by conducting
walls with propagation at various directions relative to the applied
magnetic field
   /
11358
the propagation of centimetric electromagnetic waves in an absorbing
medium of parallel wires  experimental and theoretical investigation
of the attenuation and wavelength of a plane wave in an artificial
dielectric consisting of infinitely long parallel thin poorly conducting
wires forming a regular rectangular lattice
   /
11359
measurement of a high refractive index for transmission of microwaves
through a plasma  propagation of signals between two aerials apart
in the afterglow of a argon discharge was studied  a strong magnetic
field was applied  propagation of the whistler mode was noted and
satisfactory agreement with the appleton hartree equation was obtained
   /
11360
spectral diffusion decay in spin resonance experiments  a theory
of stochastic processes affecting spin resonance is given
   /
11361
the theory of ferromagnetic resonance  expressions based on a temperature
difference greens function are derived for the susceptibility
tensor some general properties are established which are independent
of a specific hamiltonian form  the energy damping of a spin system
is also considered
   /
11362
optical maser characteristics of in  observations show that fluoresces
strongly at and  at sim stimulated emission has been found in the
infrared fluorescence line at and
   /
11363
optical maser characteristics of in  observations of in show that
the three groups of lines characteristic of appear but the precise
position of the individual lines is altered slightly
   /
11364
colloquium lasers and coherence phenomena  the text is given of the
following communications to the colloquium organized by the societe
francaise de physique in paris  on a me mathematical definition of
coherence  experimental study of the light emitted by a ruby laser
influence of various methods of optical excitation on the populations
of energy levels of ions in ruby  semiconductors and their possible
use in lasers  possibilities of semiconductor lasers
   /
11365
laser and two photon processes  the possibility of observing two
photon processes using a ruby laser is considered theoretically
   /
11366
proposal for modulating the output of an optical maser  the strong
magnetic field associated with a modulating beam is used to rotate
the plane of polarization of a plane polarized beam from another
maser which then passes through an analyser and emerges modulated
in amplitude
   /
11367
output power and possible continuous operation of ruby lasers  pink
ruby was used in an arc imaging furnace capable of concentrating
of energy as blue green light  with starting voltages between and
average output power in a pulse ranged from to  the threshold of
continuous operation was nearly achieved
   /
11368
scattering losses in optical maser crystals  an account is given
of the extinction losses resulting from the optical scattering on
small foreign particles within the maser crystal in an attempt to
explain the wide variation of maser threshold
   /
11369
gaseous optical maser with external concave mirrors  the construction
and operation of a helium neon optical maser is described  the discharge
tube is sealed at both ends with optically flat windows at the brewster
angle to the beam axis
   /
11370
nonlinear interband and plasma effects in solids  the theory takes
into account the band properties of the crystal as well as its symmetry
   /
11371
a catalogue of radio sources between declinations
   /
11372
studies in cosmic radio noise at bangalore  from the results of a
survey at bangalore see of  a value of is obtained for the spectral
index of background radiation
   /
11373
scintillations of radio stars and satellites during intense magnetic
disturbances  during periods of intense magnetic disturbance it was
sometimes found that the radio star scintillation index increased
with frequency  possible explanations are discussed
   /
11374
interferometers for a radio astronomy  a general review of current
techniques applied at several major laboratories
   /
11375
systems for simultaneous image formation with radio telescopes  to
avoid point by point scanning in radio astronomy an optical and an
ultrasonic method of forming instantaneous images are considered
practical systems with useful sensitivity and resolution will require
further technical development
   /
11376
the galactic radio spectrum down to  an analysis of results of a
number of surveys at frequencies between and
   /
11377
a high resolution galactic survey at  report of a survey of an extensive
strip of the southern milky way using a mills cross with beam
   /
11378
evidence for the transfer of corpuscles to distant parts of the sun
following a solar radio burst  microwave and optical observations
of solar bursts suggest secondary distant areas of disturbance
   /
11379
forward scatter of radio signals via meteor trails and short lived
solar radio bursts  certain features of reported solar rf bursts
may be due to the reflection of broadcast signals from meteor trails
in the radiometer aerial beam
   /
11380
design of radio telescopes for extragalactic surveys  design formulae
are given for ensuring that the number of sources resolved is equal
to the number detected  long wavelengths have several advantages
   /
11381
hydromagnetic waves and the trapped radiation effects on protons
above the proton belt  previous results are extended by allowing
the waves to travel at instead of parallel to the geomagnetic field
parts of and
   /
11382
the cosmic ray flare effect parts  a new method for finding the angular
dependence of the flare cosmic rays is described and applied to the
anisotropic part of the solar event  the observations are used to
study the interplanetary magnetic field and to compare the relative
merits of the theories of gold and parker
   /
11383
a theory of radar reflections from the moon and planets  comment
on of and authors reply
   /
11384
radar observations of meteor echoes at a frequency of mc  during
the maximum of the germinid shower of december meteor echoes were
observed at  in all cases echoes were obtained from the same meteor
trials at  these were of the long duration type associated with linear
electron densities greatly in excess of cm
   /
11385
decomposition and comparison of time series of indices of solar activity
   /
11386
the shape of the geomagnetic field boundary under uniform external
pressure  the shape of the cavity separating the geomagnetic field
from the inteplanetary plasma is calculated numerically for an idealized
model in which the plasma pressure is assumed to be constant over
the surface of the cavity
   /
11387
the interaction of the terrestrial magnetic field with the solar
corpuscular radiation  a previous calculation of on the shape of
the interface between the solar plasma and the terrestrial magnetic
field is recomputed to obtain a second order approximation
   /
11388
computation of the bounding surface of a dipole field in a plasma
by a moment technique  the cavity formed by a plasma free dipole
magnetic field in a field free stationary plasma is determined by
a numerical method  a possible extension of the theory to determine
the shape of the cavity produced in the solar wind by the geomagnetic
field is indicated
   /
11389
world wide changes in the geomagnetic field  current systems are
drawn to depict world wide changes and the mode of propagation of
these changes is studied
   /
11390
the solar and luni solar harmonic components of geomagnetic variation
at san fernando
   /
11391
fluctuations in the geomagnetic horizontal field  fluctuations in
the range and having durations from a few minutes to were studied
they seem to be world wide in their occurrence and their amplitude
depends on local time and the current  other features have been deduced
from the data
   /
11392
short range spatial coherence of geomagnetic micropulsations  with
a separation of the coherence was high  measurements were made in
a geologically uniform region and the z component of the micropulsations
was small
   /
11393
auroral zone geomagnetic micropulsations with periods of to seconds
the results of one years observations at college alaska are presented
and compared with other data
   /
11394
on the earth storms  some of the problems to be considered in studies
of storms in the upper atmosphere and outer space of the earth are
outlined  stability of solar corpuscular stream  collision with the
interplanetary plasma causes the nonmagnetized stream to lose electrons
the resulting space charge is neutralized by the change in density
of the interplanetary plasma and the stream remains stable  interaction
between the solar corpuscular stream and the ezrths magnetic field
the heating of exospheric gas caused by the compression of the magnetic
field during the initial phase of a storm is not sufficient to account
for the main phase  the main phase might however result from the
penetration of particles under the influence of a fluctuating magnetic
field  polar magnetic storms with special reference to relation between
geomagnetic disturbances in the northern and southern auroral zones
comparisons are made between the northern and southern zones on the
basis of the s field patterns indices and individual disturbances
at magnetically conjugate points  the correlation coefficient for
minute average values of disturbances at baker lake geomagnetic and
little america geomagnetic  interrelations among the upper atmosphere
disturbance phenomena over the polar regions  observations at syowa
during the period january are used to examine the detailed correlations
between geomagnetic disturbance visual aurorae and ionospheric blackouts
or sporadic e  energy and flux of corpuscular streams impinging the
earths atmosphere  an examination is made of the energy and flux
of the corpuscular streams responsible for the ionospheric blackouts
in the polar cap the unusual displays ad ionospheric effects in the
auroral zone and the red aurora observed at lower latitudes
   /
11395
statistics of geomagnetic storms and solar activity
   /
11396
an economical satellite launching technique for conducting radio
research in space  a simple and inexpensive launching technique for
economical radio research is described which employs an aircraft
and rocket combination to place a satellite into orbit  the paper
reviews the progress to date and indicates performance potential
   /
11397
satellite data analysis  an analysis of data shows a temperature
peak at and an density oscillation
   /
11398
experimental evidence for the presence of helium ions based on explorer
satellite data
   /
11399
orbiting ultraviolet system will map stars and the skys radiant intensity
an outline of camera calibration equipment and the command and
telemetry systems for project celoscope
   /
11400
orbital acceleration of satellites during geomagnetic disturbance
approximate analysis d is developed to show that joule heating of
the lower reaches of the ionosphere by geomagnetic currents is a
major factor in the modulation of thermospheric densities which causes
fluctuations in the orbital acceleration of satellites
   /
11401
infrared radiometric instruments on tiros
   /
11402
tiros radiation experiment and its physical significance  the five
channel radiometer which scans the earth by satellite rotation is
described  a mz map of the radiation received by the channel sensitive
to wavelength is compared with a conventional weather chart
   /
11403
law of electric conduction for waves in the ionosphere  the law of
electric conduction has been derived as for transver waves propagated
along a strong external magnetic field in a slightly ionized gas
the results have been applied to waves in the ionosphere
   /
11404
a note on the group refractive index of the ionosphere for zero collisional
frequency  a difference between the general expressions for
the group refractive index derived by unz and murty and khastgir
of is due to an error in sign in the former
   /
11405
recombination in the upper ionosphere  at sunrise and before noon
the loss of electrons in the f layer will occur as a result of dissociative
recombination of  the recombination coefficient will increase
linearly with temperature and the rate of production of electrons
will be proportional
   /
11406
lunar daily variation of horizontal drifts in the ionosphere at waltair
the amplitudes and phases of the hourly harmonics of the drift in
the e and f regions are given for the four seasons
   /
11407
the phase speed of a travelling disturbance in the f region of the
ionosphere and its comparison with group velocity  the phase speed
of an f region disturbance is observed to be about half the group
velocity of km
   /
11408
on the mean temporal variations of electron density at a fixed height
of the f region  a sunrise dip in the diurnal variation of deduced
from puerto rico data may possibly be explained by a reversal in
the ionospheric wind  the diurnal variations of the f layer may be
due to loss rate changes resulting from the presence of no between
sunrise and sunset
   /
11409
increases of ionization in the layer and solar corpuscular radiation
every reported large increase in ionization during a flare has been
associated with an increase in corpuscular radiation examination
of further data should lead to an exa explanation of corpuscular
acceleration processes
   /
11410
a theory of sfe current systems  a study of the development of the
current system of the solar flare effect after a sudden increase
in the electrical conductivity of the ionosphere facing the sun based
on the theory of electromagnetic induction
   /
11411
information on the ionizing radiation of solar flares from the ionospheric
absorption effect  the additional ionization is produced in a
thin layer at height and the attachment coefficient is sec  the radiation
flux deduced from the ionospheric changes agrees well with rocket
measurements  the spectrum of the ionizing radiation is probably
mainly line emission near
   /
11412
the equatorial sporadic e layer and the electrojet  data from three
chains of stations near the magnetic equator but at different longitudes
have been studied and from them it has been possible to deduce information
about the extent of the electrojet its seasonal changes and its
variations with sunspot number and longitude
   /
11413
a source of energy for the ionosphere  joule heating by electric currents
associated with geomagnetic variations is normally sufficient to
account for the heat flux in the low latitude ionosphere
   /
11414
the relationship between and magnetic phenomena  a general seasonal
relation between and is shown to be similar over a wide range of
latitudes and also for both daytime and nighttime data
   /
11415
analysis of probe characteristics in drifting plasma  for a spherical
langmuir probe moving relatively to a plasma the ion sheath is deformed
positive ion densities determined from rocket measurements in the
ionosphere for certain sheath configurations have been compared with
simultaneous observations of density deduced from curves  agreement
is good
   /
11416
satellite observations of electron content at the magnetic equator
daytime values of electron content near are obtained
   /
11417
variations of scale height in the upper atmosphere analysis of satellite
orbital data suggests a decrease of the density scale height in the
upper atmosphere from to which is attributed to a drop of in the
average temperature at km
   /
11418
the heights of ionospheric irregularities in the auroral zone  signals
from sputnik were received at points spaced by  the heights of irregularities
giving scintillation were found to range from to with occasional
higher values
   /
11419
a sequence switching unit for measurement of ionospheric drift  in
a modification of the three receiver system a unit switches the input
of a single receiver between three aerials the output signal of
each aerial being displayed simultaneously with vertical separation
on a cro
   /
11420
a study of layer effects as observed with a doppler technique  frequency
changes in the radio waves arriving at boulder colarado from are
measured  the frequency dependence of these changes is shown to give
information about the heights of ionospheric disturbances
   /
11421
a new method of space exploration by radar using incoherent scattering
discussion of incoherent scattering by spatial fluctuations in electron
density and a review of theoretical and experimental results  emphasis
is on the properties of the ionosphere
   /
11422
stability of a simplified geocyclotron model  a treatment of the
phase stability of the geocyclotron a mechanism for accelerating
electrons in the outer ionosphere
   /
11423
the radio refractive index of air  a review paper containing references
the constants in the classical debye expression for the radio refractive
index are discussed together with the errors incurred in using standard
meteorological data  model atmospheres and radio climatology are
also discussed
   /
11424
sferic observations of the severe weather on may  records obtained
with the ephi system of are presented and discussed in relation to
certain weather and propagation factors
   /
11425
diurnal power variation of the earth ionosphere cavity modes and
their relationship to world wide thunderstorm activity
   /
11426
on the design of small economical radio frequency eht supplies  particular
attention is given to the design of the high voltage transformer
the type of stabilized eht generator described is suitable for operation
at frequencies greater than
   /
11427
satellite power supply has variable pulse width  a detailed circuit
description of a short circuit proof dc to dc converter of high efficiency
with an input voltage of the output voltage is held at a power
out of
   /
11428
solar batteries for the use as the power source of unattended uhf
repeaters
   /
11429
pattern detection and recognition  both processes have been carried
out on an ibm computer which was programmed to simulate a spatial
computer  the programs tested included the recognition process for
reading handlettered sansserif alphanumeric characters
   /
