Intensities of X-ray diffraction from α-AgI at various temperatures were measured in the absolute scale by using a G–M counter spectrometer with the crystal monochromated Cu Kα radiation. Measurements of the specific heat and the thermal expansion were also performed. A drastic temperature dependence of the intensities of Debye lines and the presence of a comparatively strong diffuse background were detected. The observed intensities of the Debye lines could be explained well by the disordered structure model (or the “averaged structure”) proposed by Strock (Z. Physik. Chem., B31 (1936) 132.), assuming fairly large Debye factors for silver and iodine atoms. The intensity of the diffuse background from such an averaged structure was calculated in the similar way as in the case of binary alloys having short range order, assuming appropriate probability functions for the presence of atoms in different sites. It was confirmed that the intensity curves of the diffuse background measured at 250° and 400°C were in fair agreements with the theoretical ones. The nature of the “averaged structure” having the random arrangement of silver atoms and the origin of the large displacements of atoms from their equilibrium positions were discussed.

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The consistency of several approximate radial distribution functions of fluids is examined in the sense that the pressure and the internal energy derived from them satisfy the thermodynamical relation \frac∂∂T\left(\fracpT\ ight)=\frac∂∂V\left(\fracET²\ ight), where T, p, V and E have the usual meanings. It is found that the original form of Green’s linear theory is the only one which satisfies the above relation. It is also shown that Green’s theory can be improved further without breaking the above relation.

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Electrical resistance and magneto-resistance of gamma brass were measured at liquid helium, liquid nitrogen and room temperature. Moreover, Hall coefficient and thermoelectric power of gamma brass were measured at room temperature. Data of the electrical resistance are presented for several samples having various concentrations. In the relation between specific resistivity and concentration, a minimum occurs at about 34 wt.% copper in the curve of resistivity vs. concentration. The value of the Hall coefficient and of the thermoelectric power are comparable to the values of pure metals. The magneto-resistance is small at room temperature but becomes large at liquid helium temperature. Differences of the physical properties between gamma brass and bismuth are discussed.

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Comparing the data of AgCl and NaCl crystals, it is suggested that the contribution of lattice defects is more important than that of lattice vibrations, for the melting of ionic crystals. The coulombic interaction between defects can cause a sort of phase transition, and the transition temperature is near the melting point. Several experimental evidences: melting point, latent heat, viscosity and ionic conductivity of liquids, are also discussed on this ground.

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In complex crystals which contain groups of atoms bonded strongly with each other such as anionic radicals, complex ions and hydrated cations, low-frequency rotational vibrations of these groups of atoms may be expected to exist in addition to low-frequency translational vibrations, as in the case of ideal molecular crystals. By using an one-dimensional lattice, the modes of these vibrations are analysed. According to the results obtained, we may conclude that new additional modes appear, which is related to the rotational vibrations of the groups of atoms, and they may be classified, in general, into the optical and acoustical branches just as in the case of the translational vibrations. In addition, the effects of the introduction of these new modes upon the specific heat at low temperatures are investigated, by using the results of the analysis for the one-dimensional lattice.

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The electrical resistance and nitrogen sorption at liquid oxygen temperature were measured for barium films evaporated and heat-treated under various conditions. The conditions which provided the properties of the film were:
1. Temperature of substrate during deposition, T_d,
2. Temperature of substrate at annealing, T_a, and
3. Pressure of residual gas during deposition, P_d.
Comparing the temperature variation of electrical resistance with sorption property for nitrogen, the authors reached the following conclusions:
1. Granular structure plays an important role in resistance as well as in nitrogen sorption,
2. The contribution of the imperfections included in each crystalline lattice is also remarkable at low temperature, but decays easily at higher temperature.
Discussions are also given on the mechanism of nitrogen sorption on barium film.

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Self-diffusion of high polymer in dilute solution was studied by use of C¹⁴-labelled polystyrene. Especially the dependence of the self-diffusion coefficient of polystyrene upon its molecular weight was determined. Then, from the results, the molecular extension, the shielding ratio, and other molecular quantities of polystyrene molecule in the dilute solution were calculated by use of the diffusion theory of Debye and Bueche, and compared with the data obtained by other methods.

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The dynamic Young’s modulus and loss factor are determined by the composite oscillator method for several glassy polymers: phenol resin, polymethyl methacrylate, polystyrene, nylon 6 and polyester, in the temperature from −70° to +90°C at frequencies 50, 100 and 200 kc/s. The loss factor curve of polymethyl methacrylate shows an anomaly at ca. −20°C which is concluded to be due to the γ-transition, the activation energy being estimated as 7 kcal/mole. The moisture dependence of this transition is also shown and the molecular process involved is hypothetically proposed. For polyethylene a peak of loss factor is observed at 10°C. A procedure to eliminate the false attenuation peaks observed in applying the composite oscillator method to high polymers is described.

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The effect of hydrodynamic interaction between segments in a chain molecule plays an important role in the theory of the intrinsic viscosity of high polymer solutions. In this paper, the effect of hydrodynamic interaction is reflected into the concept of the effective diffusion tensor of a segment in a chain molecule. In performing the calculation, r_iG, the distance from the centre of gravity of the chain molecule to the cited segment, is considered as a parameter. In result, each segment has an anisotropic effective diffusion tensor, the radial component of which is about 10% larger than the transversal ones on the average. With this anisotropic diffusion tensor, the shear gradient dependence of the intrinsic viscosity of polymer solutions is deduced, making use of Rouse model. The agreement with experiments is satisfactory.

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The thermomagnetic properties of chromium sulfide CrS_1.17 were studied. The spontaneous magnetization of this compound, which is probably of the ferrimagnetic origin, suddenly disappears during cooling at −120°C. A slight heat absorption was observed at this transition point. By X-ray analysis excess diffraction lines besides those of the ideal crystal lattice of the nickel arsenide type were observed at room temperature, which shows a super-lattice structure with parameters of twice c and 2\sqrt3 times of a, a and c being those of the original lattice. It was also found by X-ray analysis that there was no change of the crystal lattice at the magnetic transition temperature, −120°C. This compound showed a ferrimagnetic behavior with the asymptotic Curie temperature at 150°K. A peak in susceptibility vs. temperature curve was found by the thermomagnetic measurement in the temperature range from the liquid helium temperature to −120°C. Basing on these data, a short discussion on the nature of the above-mentioned transition is given.

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As a first step towards constructing a high intensity electromagnetic isotope separator, the focussing characteristics of the Smythe type magnetic lens was investigated. And for preliminary experiments of isotope separation, we constructed a small mass separator of this type. The apparatus has the ion radius of 50 cm in the magnet, and has two ion sources which can be operated independently and simultaneously. The ion source was a sort of Finkelstein type and its characteristics was investigated in conjunction with the electrostatic lens system. The maximum ion current on the collector that was attained was about 400 μa and 1 ma for neon and for magnesium respectively.

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The high subsonic flow past a slender body of revolution placed along the axis of a circular cylindrical wind tunnel at zero incidence is discussed. Neglecting the square of the perturbation velocity q′2 in comparison with q′ and the spatial derivatives of q′², making use of a certain transformation of variables, the fundamental equation for determining the perturbation stream function of this transonic flow can be reduced to the equation which is formally equal to the fundamental equation of transonic flow past a two-dimensional body placed along the center line between two parallel flat walls. Considering the transonic similar solution due to von Kármán and the general similarity rule of the axisymmetric transonic flow derived by Oswatisch and Berndt, we can obtain very easily the surface pressure coefficient C_pax of an axisymmetric flow, provided the surface pressure coefficient C_p2 of a two-dimensional flow can be found.
As an example the pressure distribution on the surface of a paraboloid of revolution of finite length at Mach number 1 is obtained.

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The transonic flow of a compressible inviscid fluid past a nearly axisymmetric slender body is dealt with by dividing the perturbation velocity potential into two parts:—the one is governed by the fundamental equation of an axisymmetric transonic flow, and the other is determined by the two-dimensional Laplace’s equation in the plane perpendicular to the free-stream velocity vector.
As the axisymmetric transonic flow can be dealt with by a new approximation offered in a previous paper, and the solution of the two-dimensional Laplace’s equation is easily found, the present problem can be solved.
As examples the flow past an elliptic paraboloid of finite length is discussed and the head drag and the lift coefficients of a paraboloid of revolution of finite length are obtained.

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Lifts acting on two equal circular cylinders placed side by side in a uniform stream were measured by means of lamp scale and mirror method at Reynolds numbers from 0.01 to 1.6. The results obtained are as follows:
1. Each cylinder experiences a repulsive force.
2. The value of lift coefficient decreases monotonously as the Reynolds number is increased.
3. When the Reynolds number is sufficiently small, the value of lift coefficient increases first and then decreases as the ratio of the distance between two cylinders to the diameter of the cylinder increases.
These results are in good agreement with the theoretical conclusions which are led from the Oseen’s linearized equations of motion.
The photographs of the actual flow pattern were also taken.

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As a continuation of a previous paper, a further discussion is made on the steady slow motion of a viscous fluid past two parallel circular cylinders of equal radius with their axes in a plane perpendicular to a uniform flow, confining ourselves to the case when the two cylinders are in close proximity to each other.
Expansion formulae in powers of Reynolds number R for the drag and lift acting on one of the cylinders are obtained correct to the lowest order of Reynolds number R. The coefficients of each term are expressed in power series of a⁄2h and obtained as far as terms of (a⁄2h)⁴, where a denotes the radius of the cylinders and 2h the distance between their centres.
Up to the order of (a⁄2h)², the results are found to be in complete agreement with expansion formulae for the drag and lift acting on the one cylinder placed near the other, which has been obtained directly by expanding the formulae useful for the case when the distance between the cylinders is great.

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