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The paper considers wave coupling for an arbitrary direction of propagation on the basis of single fluid hydromagnetic equations appropriate for a rarefied plasma. The analysis is used to study the transfer of solar wind momenta into the magnetosphere. It is found that wave refraction is significant only during disturbed conditions for waves travelling with the wind. Enhanced reflection of waves might be important even under quiet conditions in the flanks of the magnetosphere.

The subjective feeling of people exposed to environmental noise is an important indicator of the assessment of noise environment. The subjective feeling under noise exposure is ordinarily surveyed on both the disturbance for health conditions and the degree of subjective noisiness or annoyance. The degree of noisiness expressed in the words for rating. If the psychophysical grade of the rating words is not measured, the interpretation on the results of survey becomes obscure. From the above mentioned viewpoint, in this paper, the psychophysical values of several rating words in the Japanese language were measured on the noisy scale.The scales measuring the noisy degree or the quiet degree were divided into 10 equal parts. Nine rated adverbs were measured on 410 female students and 70 male students aged 19 to 22 years old.These rating words are nearly identical with the following English words: extremely, very, hgghly, fairly, passably, relatively, rather, slightly, and barely.The results were as follows;1) The psychophysical values given to each of the rating words on noisy or quiet scale are given in Fig., In Fig., the modes and the ranges from 25% ile to 75% ile in the distribution are shown. The intervals between each of the values given to 9 words were unequal.2) Each of the rating words gave similar values on the noisy scale and on the quiet scale.3) No sexual differences were seen in the values of each word.4) In 5 rating words, the values on the hedonic scale reported in the reference by another author were smaller than the values of 25% ile in the distribution on noisy scale.

The auditory discrimination of first and third grade children of low socio-economic status was investigated. 17 black and 17 white children were randomly selected from the two grades. The condition for listening was varied, i.e., discrimination in condition of quiet and discrimination in condition of noise, through the use of the Goldman-Fristoe-Woodcock Test of Auditory Discrimination. White third graders were superior performers. The expectation, from the literature, that the auditory discrimination of children from low socio-economic levels would be depressed in conditions of noise was not supported. In fact, black children performed in an inferior manner in conditions of quiet.

Measurements of molecular oxygen obtained from 1450-A absorption data are discussed. Simultaneous observations with independent sensors indicate low random errors in the technique, and systematic errors are also estimated to be low. A survey of spring-fall data at middle and low latitudes during quiet geomagnetic conditions shows an average density variability, including systematic differences in the various techniques, of up to about a factor of 2 from 135 to 180 km. At the higher altitudes the Cira (1972) mean and Jacchia 1971 models tend to overestimate the densities. Data obtained during a moderate geomagnetic disturbance show density enhancements of a factor of 2.5 from 140 to at least 180 km, relative to a typical quiet profile. Although there is more pronounced wave structure in the enhanced profile, no significant changes in the mean scale heights or temperatures are seen. The Jacchia 1971 model does not adequately account for the molecular oxygen density increases during geomagnetic disturbances.

The level of the mid-latitude geomagnetic northward component on quiet days in northern summer is observed to decrease or to increase by about 5 γ, depending on whether the interplanetary magnetic field (IMF) is directed predominantly toward or away from the sun. This effect produces about a 4° equatorward or poleward shift of the Sq current focus location. A simple method to determine the IMF polarities based on the effect is suggested.

2 experiments were conducted to examine the degree of concentration on performance as a determinant in the effect of acoustic stimuli upon performance. In the Exp. I, 2 groups of female college students whose concentration on performance was high or low took part in a choice reaction time task in which 2 visual signals were presented in 2 conditions. One was a quiet condition and the other was an instrumental music condition. In the Exp. II, another group of medium concentration was added to the 2 groups and radio news and cross-talk were presented to S instead of music. The results showed that concentration on performance was a very important determinant in the effect of acoustic stimuli upon performance.

Data on the center-to-limb brightness distribution of the quiet sun at 1.2-mm wavelength are reanalyzed. The observed brightness distribution at this wavelength is plotted along the equatorial direction and analyzed to determine whether it is uniform, limb-brightened, or limb-darkened. It is concluded that at the present time, there is no evidence for a uniform or limb-brightened distribution at 1.2 mm from either an observational or theoretical point of view.

Previous work has indicated that, after sitting in a quiet room for one hour, subjects with normal hearing can show substantial improvements in hearing acuity. Such effects could have important consequences when the threshold of hearing is measured over similar periods of time under continuously quiet conditions. An experiment was carried out to re-evaluate this effect and to obtain some indication of its possible cause. Attempts to re-arouse the threshold were also made by the presentation of noise and exercise stimuli at the end of the quiet period. When a more sensitive audiometric technique was used, a slight quiet threshold shift of the order of 2·5 dB was measured. No definite conclusion could be drawn as to the exact cause of this shift, but it would appear to be due to a combination of a recovery from temporary threshold shift caused by exposure to everyday noise and a reduction in the subject's internal physiological noise during the experiment.

The magnetic perturbation patterns in the polar cap and auroral zone regions are obtained for extremely quiet days using two different techniques. It is shown that the form of the equivalent current flow pattern is extremely sensitive to the level of quietness, and that even so-called quiet days are at times disturbed by substorm activity. Certain characteristic equivalent flow not typically observed during substorms is noted in the polar cap, and this flow appears to be associated with effects of polar cap perturbations discussed by Svalgaard (1973). A region of equatorward flow at high latitudes near the dawn meridian, appears to be Hall current driven by an eastward electric field. The dayside sub-auroral zone is dominated by the Sq-current system, while the nightside shows no significant current flow in the absence of substorm activity.

Experimental investigations were performed in a visual carrier landing simulator to determine the accuracy and consistency with which Navy pilots can judge position on the glide slope and flight path during final approach. These studies covered conditions involving a quiet sea state in which there was no angular deck motion present, as well as a moving deck. The effects of dusk and night landings and the presence of the Fresnel Lens Optical Landing System (FLOLS) were includ ed. The results indicate that pilots' mean estimates of position when on-course are within a small fraction of a degree of being correct under dusk and night conditions, with a static or moving carrier, with and without the FLOLS. However, variability in judgment is high. Sensitivity to changes in position is reduced with a moving carrier, and falls to a low value of about 40% at night, without the FLOLS. Mean estimates of flight path are within 4 min of arc of being correct when the aircraft is flying toward the desired aim point under all ambient and ship conditions. Again, variability in judgment is high. Sensitivity to changes in aim point is low, falling to about 10% at night.

Flyover noise characteristics are presented for the Boeing 707‐300B/C equipped with standard production nacelles and with experimental quiet nacelles modified by the addition of sound‐absorbing materials. Acoustic‐treatment theory and technology required to develop the quiet nacelles are discussed. Results from, and techniques for, noise‐certification flight testing to meet FAA regulations are presented. Comparisons of noise levels of a modified 707 aircraft, noise floors, and noise from other operational aircraft are provided.Subject Classification: 50.40, 50.50, 50.55, 50.75.

An inversion technique is outlined for calculating the resolution and gross error associated with D-region electron density profiles obtained by modelling from a given set of VLF radiowave propagation parameters. Two profiles, representing quiet and disturbed ionospheric conditions, are examined in detail and the height resolution and accuracy obtainable from the amount of observational data used in constructing these profiles is determined.

Eight hearing-impaired subjects were tested with a binaural master hearing aid. This aid has “on-the-head” miniature transducers and has an adjustable frequency response. Five frequency responses were used, two of them were defined by their response in a 2-cm3 coupler: 1) uniform coupler gain (UCG), and 2) 6 dB per octave rise (6 dB). The other responses were defined in terms of functional gain (difference between unaided and aided thresholds): 3) uniform functional gain (UFG); 4) uniform hearing level (UHL); and 5) a simulation of a commercial hearing aid (AS). A significant difference between coupler and functional gain was seen. Discrimination was tested with a special closed-set word list which includes fifty monosyllabic words with a high percentage of voiceless phonemes. Discrimination scores were consistently better with the UHL response. The lowest scores were obtained with the AS response. The average difference in scores between these two responses was 18.4%. Further testing replicated these results and also compared the effects of a different type of word list phonetically balanced (PB); with these lists, the above-mentioned difference in scores was smaller in quiet (5.9%) but larger in noise (20.9%).

The quiet-time depression of the magnetic field magnitude in the equatorial inner magnetosphere was studied for the interval Nov. 1971-June 1972. For periods when Kp was less than 2 and Dst was between +10 and -20 gamma, an inflated field region near the magnetic equator was found between noon and midnight. The inflation was greatest at the lowest altitude studied (L = 3) and appeared to be somewhat greater near midnight (-40 gamma) than near noon (-20 gamma). Protons of energy above 100 keV observed on the same satellite appeared to be sufficient to produce the quiet-time inflation.

Forty older (age range 65-72 yr) and 40 younger subjects (age range 18-31 yr) performed a 15min cancellation task and. a 20 min version of the Continuous Performance Test (CPT). They worked either in noise (95 dBA) or quiet (70 dBA) and either in the morning (10 a.m.) or the afternoon (2 p.m.) In the cancellation task older subjects worked significantly more slowly and significantly less accurately than younger ones. However, noise significantly improved the rate of work for older subjects, but not younger ones, without impairing accuracy. Older subjects, but not younger ones, also were significantly more accurate in the afternoon. The performance of older subjects on the CPT was significantly interior to that of younger subjects. Afternoon testing again improved the performance of older subjects to a greater extent, Relationships between speed and accuracy measures, between performance and verbal intelligence and between performance and sociability were also assessed. The results of the two studies are d...

Five experiments were conducted with normal listeners to investigate the reliability (stability) and validity (accuracy) of adaptive tests for measuring the linear portion of CNC discrimination functions. Monosyllables (consonant‐vowel‐consonant form) included in Northwestern University Auditory Test No. 6 were employed as test stimuli. Constant‐level tests were used as criterion measures to judge the accuracy of best‐of‐five (100 words), best‐of‐three (50 words), doublet (50 words), and simple‐up‐and‐down (50 words) adaptive tests. All tests were conducted under monaural (earphone) listening conditions in quiet or against a background of either 60‐ or 80‐dB‐SPL white noise. The shorter doublet tests were found to be as stable and accurate as the longer best‐of‐five procedures when seeking levels required for approximately 30% and 70% CNC discrimination. Adaptive tests using 50 words appear to be highly reliable and valid for determining the location and slope of CNC articulation functions with normal listeners.

A ground-based meridian-scanning photometer was operated at Cape Parry, N.W.T., Canada (70°N, 125°W geographic) in November and December, 1973, to observe the atomic oxygen emissions at 6300 A and 5577 A, and the H-beta emission at 4861 A. A 6300 A behaviour pattern that could be identified with the dayside cleft was observed during a quiet afternoon and during a magnetically disturbed period. During quiet times a 1 kR 6300 A feature was observed at 78° invariant latitude while during a modest disturbance the intensity increased to 4 kR and the feature moved to 73° invariant. This confirmed that the 6300 A signature is readily identifiable from the ground, and that Cape Parry is one of the few relatively accessible Northern hemisphere sites where the optical cleft emissions can be observed from the ground.

In a testing situation, factors other than the test itself may influence test performance. It is generally assumed that a quiet, distraction-free situation is necessary for testing. Test manuals and texts on the topic of test administration usually indicate that distraction-free situations promote better test performance than do distractive environments. Classroom teachers normally try to establish conditions as "ideal" as possible for testing. Research does not support the general assumption that distractions in the testing situation influence test scores. Probably the best known study of distractions' effects on test performance was conducted by Super, Braasch, and Shay (1947). The Minnesota Vocational Test for Clerical Workers and the Otis Quick Score Gamma Am were given to graduate students. One group was tested under "normal, quiet" conditions. Another group was subjected to such distractions as breaking pencils, arguments in the hall, apparent mistiming, and a poorly played trumpet. Analyses of test scores showed no differences in the performances of the two groups. Hovey (1928) and Standt (1948) also experimented with distractions in a college level test situation. Hovey found that with college sophomores, distractions such as noise, lights, music, whistles and stunt man performances did not effect performance on the Army Alpha Test. Standt tested college women with several measures which included verbal analogies, cancellation, addition, multiplication, and with the Otis Self-Administering Intelligence Test. Every 30 seconds a buzzer was sounded and subjects were told which problem to begin on next. While this study may have confounded distractions with instructions, the main interest was in the distraction condition. No significant differences were found in accuracy of performance. In a study using high school students, Ingle and DeAmico (1969) found that conditions in the testing room did not affect standardized achievement test scores. Insofar as poor lighting, poor writing surfaces and such can be considered distractive, distraction had no influence.

This study examined the effects of classroom noise on an auditory processing task of learning disabled children, with distractibility, activity, and cognition controlled. Forty children divided into normal and learning disabled groups were administered both forms of the Wepman Auditory Discrimination Test. Two listening conditions were tested: (1) the relative quiet of small test rooms, and (2) classroom noise (on a tape recorder) in the same test rooms. Results showed that learning disabled children made significantly more auditory discrimination errors than normals in both quiet and noise conditions. Both normal and learning disabled children made significantly more auditory discrimination errors in noise than in quiet. It cannot be said that the noise affected the two groups differentially; the magnitude of the differences was comparable statistically. It was concluded that auditory discrimination scores in quiet do not reflect accurately the expected value for the classroom.

Here the theory developed in a previous paper is applied to a many-neuron model representing the brain. It is shown that this model may exhibit quiet states in which it functions as a system of coupled harmonic oscillators. The problems arising in the specification of the synaptic and environmental coupling parameters, and a set of compatible initial conditions are resolved, and by an analysis of the normal modes it is shown that in quiet states even a small model consisting of twelve neurons will reflect in magnitude and distribution the basic waves observed in electroencephalograms.

18 subjects carried out a 30 min 5-choice serial response test 6 times under all possible combinations of alcohol (at zero, ‘ low ’ and ‘ high ’ concentrations in the bloodstream) with quiet (70 dB) and continuous ‘ white ’ noise (100 dB) conditions. Speed of responding was significantly decreased by noise, but not by alcohol; there was no interaction between the two stressors in this aspect of performance. However, a clear interaction was observed in accuracy, the error rate increasing with alcohol under quiet conditions, and decreasing under noise conditions, in such a way that the separate effects of the two stressors were effectively cancelled out when administered in combination. The results are interpreted as supporting the view that noise functions as an ‘ arouser ’ and that alcohol, in its physiological role as a cortical depressant, acts in the opposite direction.

A linear relationship between the hourly Dst value and the inverse of the cube of the magnetosphere subsolar distance Rs−3 from Explorer 12 satellite boundary observations has been found to exist for geomagnetically quiet times and slightly disturbed periods. The proportionality constant between the Dst and Rs−3 is found to be 1.40 times the theoretical value predicted by Mead but remains unchanged for different geomagnetic conditions. The only changes are the amount of the field depression due to the ring current registered in the Dst values. The field depression at the earth's surface is found to be −19 γ from the quiet time ring current and −44 γ from the slightly disturbed time ring current.

Results of eight years of measurements on Whistler-mode signals from station NLK (18.6 kHz) propagating in the vicinity of L = 2.5 are presented. The statistics of occurrence indicate a considerable extent (at least 6000 km) for the longitudinal window within which it is assumed ducts must be if a signal is to be received at a particular station. A significant increase in signal amplitude 2–3 days after a magnetic storm is found. A consistent pattern is found in the nightly variations of doppler shift, but there is a marked difference between the June and December solstice data. The magnitudes of the shifts are comparable with those expected from Sq electric fields, but there is little agreement between the predicted and observed variations of doppler shift. This may be related to ionosphere—magnetosphere coupling fluxes.

In order to examine the effects of aircraft noise on the mentality of growing children, a simple search task and an adding task were applied to 1144 elementary school pupils who live around an airport, and in a quiet area, under the conditions of no stimulus sound, and jet noise stimulus 90 ± 5 dB(A) respectively. The result was that children from relatively noisy living areas tended, when performing tasks, to show occasional short periods in which they produced substantially less than their own average rate of work. A similar difference did not appear when working in noisy rather than quiet conditions, and it was considered to be something chronic about the children themselves. These results were independent of the sex of the subjects and the feelings of the subjects about aircraft noise.

We introduce two new computer models in which the influence of the finite potential mesh is, for most practical purposes, eliminated. The Quiet Particle-Mesh model (QPM) uses a Gaussian-shaped charge cloud and careful shaping of the potential solution in either real or transform space. The QPM model is measured to be 150 times less noisy than the conventional CIC model and is suitable for large collisionless plasma simulations with 10 5 or more particles. This is achieved at little or no cost in computing time. The hybrid Particle-Particle/Particle-Mesh model (PPPM), on the other hand, adds to the above mesh calculation contributions from nearby particles by direct summation. This model has a spatial resolution which is independent of the mesh spacing and may be a small fraction of a mesh cell. It is more time-consuming and is suitable for high-resolution sub-Debye length investigations with a smaller number of particles (∼10 4 ). Applied to molecular dynamics, the PPPM model can simulate systems with approximately 100 times the number of particles than conventional methods.

In a Quadraphonic Hi-Fi system it would be highly desirable that the two rear speakers be wireless. The two rear speakers would be completely independent from the main unit and would be composed of a receiving system, power amplifier and speaker. A short range communication system is needed that has full Hi-Fi performance; a bandwidth of 50 to 15 KC signal-to-noise ratio greater than 60 dB and total harmonic distortion of less than 1%. Also, the cost of the system should be as low as possible. There should be no interference between the two rear speakers or with a neighboring system in a nearby room. It would be desirable that the volume level and balance of the whole system could be accomplished at the main unit. This would necessitate that each of the rear speakers also have a remote volume control function. This may be accomplished in two manners. A special control signal may be sent to each of the rear speakers where it will be decoded and set the volume level of that speaker; or, the signal-to-noise ratio of the system can be raised sufficiently high so that the power amplifier can be operated at full volume and during a quiet passage no background noise be heard in a quiet room. A signal-to-noise ratio of approximately 85 dB would be needed.

Eight rockets among a total of twenty-one rocket experiments by the 12th, 13th and 14th Japanese Antarctic Research Expedition parties were launched during auroral disturbances at night at Syowa Station, Antarctica between 1971 and 1973. The electron density profiles in the lower ionosphere between about 50km and 130km under various disturbed conditions were obtained by rocket-borne radio frequency probes and electrostatic probes.The collision frequency profile is derived from the electron density profiles and cosmic noise absorption measurements. There exists a maximum absorption layer in the region between 75km and 85km, and this location of the layer is not strongly dependent on the magnitude of the ionospheric disturbance. An increase in the electron density, especially in the D and E region between about 75km and 110km has a good correlation with cosmic noise absorption; the following empirical formulae are obtained from the observational results:Δne=exp(0.205x+4.67), hm=-2x+100, where Δne(cm-3) is the maximum increment of the electron density from the quiet level, hm(km) is the height of the maximum increment of the electron density and x(dB) is the cosmic noise absorption.

An innovative way of using audio-visual programs to help in the education of preschool children and older children with learning disabilities is described. Traditional audio-visual methods usually demand that the child sit still, remain quiet, and look and listen. These demands are too stringent for these young children to meet successfully; so, in the past, media has not been effectively used in early childhood education. Project "ME" has designed a system which enables children to interact, with a life-sized projected image, motorically, tactically, and verbally. Opportunities for visual-perceptual-motor training are expanded and programs have been designed to promote emotional awareness and enhance self-concept. An evaluation of two of the interactive programs is presented.

Quiet and disturbed variations of the rotational temperature of the hydroxyl emissions of the night sky in band 4-1 are described. Examples are given of wavelike propagation of the disturbances of rotational temperature.

The flux of the radio quiet Sun and the brightness temperature at 408 MHz (73 cm) are derived from measurements with the E-W Nancay interferometer and the E-W arm of the Medicina North Cross. It is shown that the lowest envelopes, which defined the radio quiet Sun, correspond to transits of extended coronal holes across the disk of the Sun.

High resolution incoherent scatter electron density data using Barker-coded pulses are presented for two separate 24-hr periods of very different magnetic conditions. The first period in April 1972 was magnetically quiet while the second period spanned parts of two of the five most magnetically disturbed days in July 1972. Solar activity was low with 2800-MHz indices of 129 and 128 for the April days and indices of 109 and 117 for the July days. Contour plots and selected profiles are presented which show larger sporadic-E layers and stronger gravity wave effects during the disturbed night than during the quiet night.

Spatial power spectral densities of velocities in plages were compared with velocity power spectra of the quiet photosphere. The comparison suggests that photospheric oscillations are not gravity waves.

Normal-run magnetograms for the year 1967 from seven Canadian observatories were scaled to study the amplitude characteristics of Pc 5 pulsations. The results of the statistical analysis are: (1) Large amplitude Pc 5's occur in a limited region located on the poleward side of the auroral zone. (2) The diurnal variation of Pc 5 amplitude maximizes in the postnoon period at Resolute Bay and this peak tends to appear earlier and earlier in the day at the lower latitude stations, e.g., it appears in the morning at Great Whale River. An additional midnight peak in the diurnal variation of amplitude is noted at auroral zone stations. (3) The amplitude attains a maximum value at Great Whale River near the central line of the auroral zone. It decreases at a faster rate toward the lower latitudes than toward the higher latitudes. In quiet intervals an additional peak in the amplitude-latitude profile is noted near the cusp region at Baker Lake. (4) The diurnal variation pattern of amplitude shows no clear relationship with the seasons or with magnetic activity. (5) Under disturbed magnetic conditions a much larger amplification of the amplitude of Pc 5's has been at Great Whale River than at high or low latitude stations. Pc 5 amplitudes correlate very well with Kp up to a level of 6−. (6) With increasing solar elevation angle the region of maximum amplitude of Pc 5 is found to move toward the northern border of the auroral zone. (7) From the data analyzed, amplitudes of Pc 5 do not show a 27-day recurrence tendency.

And suddenly, in the same quiet voice with which he had just set forth the long-range, interesting plans of the ministry, the department head said to me: "But as far as the committee is concerned, its existence makes no sense to me. What do we need this amateurism for ? I do not see how it can be useful to us."

Detailed Explorer 45 equatorial observations of the quiet time structure of radiation belt electrons (35–560 keV) for 1.7 ≲; L ≲ 5.2 are presented. Throughout the slot region and outer regions of the plasmasphere the observed pitch angle distributions are found to agree with those expected from resonant interactions with the plasmaspheric whistler mode wave band. Coulomb collisions become the dominant loss mechanism within the inner zone. The overall two-zone structure of the observed radial profiles is found to agree with the equilibrium structure expected to result from a balance between pitch angle scattering losses and radial diffusion from an average outer zone source. This agreement suggests that the dominant quiet time source and loss mechanisms have been identified and evaluated for energetic radiation belt electrons within the plasmasphere. In the outer regions of the plasmasphere (L ∼ 5) the equilibrium structure is observed to be modified by daily flux variations associated with changes in the level of magnetic activity that occur even during relatively quiet times. Within the inner region of the plasmasphere (L ≲ 3.5), electron fluxes are decoupled from these magnetic activity variations by the long time scales (>10 days) required for pitch angle and radial diffusion. Consequently, fluxes of these electrons are observed to remain nearly constant at equilibrium levels throughout the quiet periods examined.

In Part I a summary of quiet D-region electron density measurements made by tlie wave interaction technique at The Pennsylvania State University for the period October 1969 through January 1971 is presented. The results include the mean features of noontime electron density profiles as well as the diurnal and seasonal variations. Detailed discussion on the methods of data analysis, including a critical evaluation of errors, is also presented. The results presented in the part form a partial basis for developing the semi-empirical D-region model presented in Part II.

Until recently railway noise has been accepted as a well established but dwindling source of noise nuisance, and has been subject to relatively little sociological study. The proposal for high speed trains through previously quiet areas has however called for the establishment of subjective noise zones. The paper puts forward such zones, based upon sociological data in other countries and on aircraft, road traffic and community data in the United Kingdom. Planning zones are calculated for the expected frequencies of rail services, and based upon the estimated and measured noise levels of high speed trains. Some comments are made upon the generalization of this information, and on the effects of barriers, cuttings and distance; and on vibration and shock effects near to the railway line itself.

Precise orbit determinations of five Air Force low-altitude satellites are used to estimate winds near 150 km from variations in the satellite orbital inclinations. Zonal winds determined by this method range from 25 to 200 m/sec during quiet to moderately disturbed geomagnetic conditions, to winds on the order of 300–600 m/sec during active geomagnetic conditions. Comparisons are made with other wind data and appropriate theories.

(1975). Nisei: The Quiet American? A Re-evaluation. Amerasia Journal: Vol. 3, No. 1, pp. 114-129.

The TEWAC (totally enclosed water-air cooled) induction motor is not a new development. Such machines have long been common in Europe. Their usage in the United States has been less frequent, but growing emphasis on noise reduction is creating new interest in the inherently quiet TEWAC machine. Review of current specifications and orders shows that many motor users, inexperienced in TEWAC applications, are uncertain how to deal with possible cooler leakage, water flow control and monitoring, effects of high water temperature, motor rating versus ambient temperature, water chemistry, and cooler construction and mounting. Each of these matters is discussed in detail.

Summary A procedure is proposed for the analysis of daily variations recorded by magnetometer arrays, based upon the analysis of each quiet day as an individual and complete event. Such an approach is justified by the argument that any particular observatory has no premonition of variation to occur on the next day, and records only an insignificant signal from the variation of the day before. Many of the factors affecting the variation on an individual day are independent of the rotation of the Earth, and are also therefore independent of the strong 24-hr, 12-hr, 8-hr and 6-hr periodicities usually associated with daily variation analyses. Data for individual days are transformed into the frequency domain and plotted on polar diagrams. For an array area, the separation of anomalous fields from regional fields is based upon determining the latter as a smooth curve on a polar diagram. If a sufficient number of days are available for analysis, and they are sufficiently varied, all nine elements of a transfer function matrix may be sought, relating locally anomalous fields to regional fields.

Three parameters of the solar wind, proton number density n , Z -component of frozen-in magnetic field, in solar ecliptic coordinates and magnetic field variability ΔB , may be called geoactive parameters since each of them is responsible for a certain phase or stage of a geomagnetic storm. An undisturbed solar corpuscular stream differs from the quiet solar wind mainly in higher bulk velocity v ; other parameters, in particular, n , Z and ΔB , are not enhanced in the stream. However, the examination of a number of geomagnetic storms shows that v is not a geoactive parameter. Hence the corpuscular stream itself is not more geoactive than the quiet solar wind. The retarding of corpuscular stream by the quiet solar wind results in various plasma deformations (compression, torsion, shear). This, in turn, leads to the creation, in the stream and ambient quiet solar wind, of geoactive zones. Each zone is characterized by the enhancement of some geoactive parameter. The entry of the Earth into a geoactive zone causes a corresponding phase or stage of a geomagnetic storm. The concept of geoactive zones is applied to the analysis of the geomagnetic storm of 8–10 July 1966.

Variations in the total (i.e. scalar) magnetic field data from the polar orbiting OGO-2, 4, and 6 spacecraft (altitudes 400-1510 km) are summarized for invariant latitudes above 55 deg. Data from all degrees of magnetic disturbance are included. The data are presented in terms of the quantity delta B(= measured field magnitude minus the field magnitude from a spherical harmonic model of the quiet field).

Periodic time variations in the emission of quiet solar regions were sought with the NRAO three-element interferometer at 3.7 and 11.1 cm. The visibility function of a source as obtained with a tracking interferometer is an implicit function of time, because of projected baseline changes, and therefore only observations taken when the baseline changes vary slowly with time were used. The visibility function shows significant time variations, but a power-spectrum analysis of the data revealed no unique periodicity.

The control of noise in electrical machines may be effected by two separate and distinct methods. The first is the reduction of the noise at the source and the second the attenuation of this noise before it reaches the ears of the observer. Since noise reduction is costly, the problem is resolved into one of finding the most economic means of obtaining the required noise reduction, without interfering with the efficient functioning of the plant. It is generally considered that a good machine should run smoothly and quietly, so from the earliest days the designers and manufacturers have put a great deal of effort into producing quiet machines and more recently considerable research effort has been expended in explaining the basic phenomena.