Expected behaviours of magnetic poles, especially their interaction with magnetic matters are considered. The magnetic pole is supposed to be an elementary particle having magnetic true charge satisfying Dirac’s quantum condition, namely 68.5 times as large as the electron charge. Magnetic poles would be attracted and trapped in ferromagnetic and paramagnetic matters. The magnetic minerals are the most promising source of magnetic poles and an efficient method for detecting the presence of even one magnetic pole among thousands of tons of magnetic minerals is proposed. This method is sensitive enough to detect such a small amount of magnetic pole as has escaped from the whole cosmic ray observations so far conducted.

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Internal conversion electrons of 0.84 Mev gamma ray were measured by a two-directional focusing beta-ray spectrometer, and it was determined that E_γ=837.9±0.3 kev and K⁄L+M=8.5±0.7. Weak gamma rays were searched, using scintillation counters, but no gamma ray was observed.

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The grain boundary in deformed bicrystals of α-brass has the hardening layer of 50∼100 microns in thickness. Evidences for the assumption that the hardening is attributable to the dislocations piled up against the grain boundary were provided by the fact that the amount of hardening could be reduced by the application of reversed stress, and also by the analysis of the hardness distribution which showed the amount of hardening to be approximately proportional to the density of piled-up dislocations.

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The natures of V bands in the additively colored crystals of KBr has been investigated. Mollwo’s results were confirmed and extended. A new technique of additive coloring was devised to produce a high concentration of V centers in the crystal of KBr. By using this method, the degree of coloration could be increased by about ten times of that reported by Mollwo. Besides the well-known V₂ and V₃ bands, another band of V-type was observed below 210 mμ.
It was found to be possible to color electrolytically the crystal of KBr revealing the same absorption spectrum as that of additively colored crystals. Evidently, this confirms that these absorption bands are produced as the result of the combination of positive holes and positive ion vacancies. Discussions were made in comparison with the results obtained for KBr colored with X-rays.

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Magnetic measurements were performed on the specimens of powdered and single crystals of nickel sulfide having the structure of nickel arsenide type. From the results of measurements of the susceptibility, specific heat and other data, it was found that nickel sulfide is antiferromagnetic with the Néel point at 150°K. However, below 120°K, the susceptibility of the powder specimen increased with the fall of temperature and also showed a dependence of magnetic field. Such a rise in susceptibility at lower temperatures is here interpreted as due to the influence of paramagnetic islands. Correction for the atom core diamagnetism was applied to the observed susceptibilities, and from the inverse susceptibility vs temperature relation, the Curie constant per mol, C_M, the spin quantum number, S, and the asymptotic Curie temperature, θ, were obtained as 0.89, 1.9/2 and ca 3000° respectively. From the torque measurement of a single crystal of this compound, it was seen that the antiferromagnetic easy direction lies in (0001) plane of the crystal.

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The wedge type relaxation spectrum of amorphous chain substances having next-nearest neighbor interaction is derived. The interaction is taken in the form of special square type potential against a distance. The potential indicates that the chain has stiffness. The equation of motion is solved by normal coordinate method for Bueche’s vibrating string model.
The slope of the relaxation spectrum of our model is steeper than that of ideal elastic chain model for which the slope of −1⁄2 in the log-log plot is proved, and quite coincides with the experimental data.

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A metallographical investigation of manganess-aluminum system was made in the compositional range of 47% to 60% of manganese, with the results of a new hexagonal close-packed phase and a metastable tetragonal ferromagnetic phase derived therefrom. The conditions necessary for formation, structure, stability and thermal and magnetic properties of the latter phase have been studied. A discussion was also given on its magnetic properties.

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The effect of end-linking induced in polymers by high energy radiation is discussed. When cyclization does not occur, the same results are obtained as those derived by A. Charlesby, and moreover it is known that for any initial distribution the gel formation does not occur when σ is smaller than 1/4, where σ represents the probability that an end produced by a molecular scission links with a monomer unit of another molecule. The theory also gives the average molecular weights and the average end numbers. For the initial uniform distribution the weight average molecular weight has a maximum in case 1⁄12<σ<1⁄4, while for the initial Poisson distribution it has no maximum. The weight average end number becomes infinite at the gel point, but the number average end number does not. It is shown that the retardation of incipient gel formation is negligible when cyclization occurs. Beyond the gel point the gel part grows rapidly. The feature is studied in the cases of cross-linking and end-linking with or without cyclization, and it is shown that the gel fraction is smaller by several per cent in the case with cyclization than in the case without cyclization.

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It was known that solubility of irradiated polymers was not free from the effect of cyclization. On the contrary, viscosity before gel point is not affected by it and it is utilized in order to investigate the effects of high energy radiation on polymers. Intrinsic viscosity is discussed first for the case where cross-linking and degradation occur. In certain cases intrinsic viscosity decreases in the initial period of irradiation, but increases in larger radiation doses, so that it has a minimum and becomes infinite at a certain radiation dose which corresponds to gel point. It is also derived that G-value of cross-linking and degradation are calculated from the intrinsic viscosity in the initial period of irradiation. An example of polyvinylchloride gives G-values whose orders of magnitude are not unreasonable. The more accurate is the measurement, the more correct values will be obtained. Intrinsic viscosity for the case where end-linking occurs is likewise discussed, and the same properties as those in cross-linking are derived. Finally we know that the gel point determined from an asymptotic behaviour of intrinsic viscosity will be more correct than that determined from an extrapolation of solubility curve.

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The excitation of oscillations in a uniform plasma by an injected electron beam is considered. The dispersion relation for this system is derived by means of Fourier-Laplace transform method. The solutions of the dispersion relation are obtained which yield the characteristics of excited waves; the frequency, the phase velocity and the time-rate of wave-growth as functions of the wave number. It is demonstrated that the wave characteristics are varied by the influence of thermal velocity of electrons in the main plasma and by taking the ratio of electron density in the beam to that in the main plasma over a wide range of values. It is then examined that both the velocity spread in the beam and collisions in the medium have the decaying effect on the growing wave. By the use of the above results the case is also discussed where the main plasma is bounded by ideally thin sheaths.

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Pfund’s half-shade analyzer, which originally was devised for the measurement of the Brewsterian angle, \varphi_B, can be applied to the measurement of the principal angle of incidence, \varphi_p. Its sensitivity, h, and possible sources of systematic errors are discussed. It is shown that, in the measurement of \varphi_B, h can be made to approach ∞, but in the measurement of \varphi_p, h is finite and sometimes very small. A superior half-shade device for the precise determination of \varphi_p is proposed, which consists of a λ/4-plate, a half-shade plate of the type of Bravais bi-plate, and an analyzer (polarizing plate). Its sensitivity is fully discussed and the systematic errors are analyzed. Experimental test of the new device is briefly described.

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The “netted ring approximation” is proposed. Several thermodynamic properties are derived by means of this approximation. The radial distribution function is also derived, the expression of which is similar to one based on the netted chain approximation of Rushbrooke and Scoins. The possibility of a phase change in the gas of hard spheres is pointed out.

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Under the well-known assumption in magnetohydrodynamics, the distributions of velocity, magnetic field, and related quantities such as pressure, electric field and current density are obtained for the flow of an incompressible, viscous and electrically conducting fluid due to an infinite oscillating flat plate in the presence of transverse magnetic field.
General solutions are first derived and then some special cases are discussed corresponding to limiting values of parameters such as magnetic pressure number S and magnetic Reynolds number R_m.
It is found that each of the velocity distribution and other related quantities consists of two different oscillations whose decaying factors differ from the corresponding wave numbers, which contrasts to the well-known velocity distribution in classical hydrodynamics.

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The two-dimensional potential flow of a compressible fluid past a family of cylindrical obstacles with two parameters which includes elliptic cylinder and Kaplan bump is investigated by use of Imai’s method.
An very interesting example has been found such that the surface velocity distribution changes its character with increasing Mach number, namely, it has two maxima for M=0, which tend to coalesce into one as the Mach number increases. Such an effect, however, is very small within the approximation used.

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Two-dimensional incompressible viscous flow past a lattice of equal parallel and equidistant flat plates without stagger placed parallel to a uniform flow is studied on the basis of Stokes’ approximation by use of the Fourier transformation method. Asymptotic solutions are explicitly obtained for two cases h→∞ and h→0, where h is the distance between the neighbouring two flat plates.

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Accuracy of the linear dependence of the molecular sound velocity on the molar fractions of the component liquids was investigated in about 100 binary mixtures, employing existing ultrasonic data. The linearity proved to hold true within an accuracy of 0.3% for mixtures of two hydrocarbons or two monovalent alcohols, among others, while the deviation from linearity was larger (0.3%–4%) for the following mixtures: the aqueous solutions, mixtures containing one heavy component such as carbon tetrachloride or chloroform with light partners, mixtures containing glycerine, glycol, aniline, acetone, nitrobenzene, etc. The molecular compressibility (of Wada) showed a similar tendency, though the deviation from linearity was somewhat smaller than that of the molecular sound velocity, especially in case of the mixtures consisting of two component liquids of widely different densities.

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An empirical formula V=(R⁄v)³={(n_AR_A+n_BR_B)⁄(n_Av_A+n_Bv_B)}³, was derived for the sound velocity in binary liquid mixtures consisting of two component liquids A and B, on the assumption of the linear dependence of the molecular sound velocity R=vV^1⁄3 (v=molar volume and V=sound velocity) on concentration (molar fractions n_A, n_B) and the additivity of the molar volume. The suffixed quantities correspond to the component liquids. This formula holds true for such mixtures for which the linearity of the molecular sound velocity and the additivity of the molar volume is comparatively good, the mixtures of two hydrocarbons and those of two monovalent alcohols being the examples. The values of the empirical sound velocity were compared with those calculated by this formula for 38 mixtures with comparatively small values of the percentage deviation from linearity of R, and 28 of them showed deviations not larger than 1% in V. Of the 31 liquid mixtures with ΔR⁄R≤0.3%, 5 showed deviations of V larger than 1%, 4 of them being the mixtures consisting of two component liquids of widely different molar volumes.

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A study is made on various condenser microphones, each of which consists of a metallic back plate and a thin plastic film stretched over the back plate, being in direct touch with it at a number of points. The surface of the back plate has been roughened or provided with grooves, hollows or holes, while the external surface of the plastic film has been made conductive by metallizing it.
The microphones are calibrated in the frequency range 1.5∼150 kc/s. A fair agreement is found between the classifications of the back plates according to the mechanical roughnesses of the surfaces and the classifications based upon the frequency responses of the microphones. It is shown that the microphones with the back plates having finely roughened surfaces can be considered as single resonance systems.
Detailed data are given, with which a microphone having a flat frequency response up to a desired high frequency below 150 kc/s can be easily constructed.

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