The beta-ray spectrum of potassium-40 has been studied using the scintillations from the crystal of potassium iodide activated with thallium iodide. The Kurie plot of the spectrum gave the forbidden shape, which was straightened from the end-point 1320±20 kev down to well below 300 kev by the third forbidden tensor (or axial vector) correction factor. Measurement on the specific activity has also been carried out and resulted in the value λ(β)=5.0±0.2×10⁻¹⁰ per year. This value is in good agreement with recent determinations.

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Zeeman patterns of the nuclear quadrupole resonance line of Br⁷⁹ were studied with a single crystal of paradibromobenzene. The crystal contains two classes of molecules with equal positive and negative inclinations against the crystallographic b-axis. Changing the orientation of magnetic field in the plane perpendicular to the b-axis, the Zeeman patterns were measured. The asymmetry parameter of the coupling, η, was determined from the pattern at the magnetic field perpendicular to all carbon-bromine bonds. The result was η=0.12±0.01. The coupling constant, eQq, was measured as 535.19 Mc at 14°C. If the asymmetry parameter is completely due to the resonance of a double bond structure in the carbon-bromine bond, the observed value gives 4.5 per cent double bond character.

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Mulliken’s Magic Formula is applied to the calculation of the dissociation energies of molecules of the type A–O–A. s p hybrid atomic orbitals are used as wave functions of oxygen orbitals, and dissociation energies are derived for various values of the bond angle and the interatomic distance. In the case of H₂O, dissociation energy was obtained to be 9.39 eV., bond angle, 100°, and interatomic distance, 2.0 a_H. In the case of F₂O, these were 5.62 eV., 92°, and 2.8 a_H. These values are close to the experimental values, as expected. It might be concluded, therefore, that Mulliken’s Magic Formula is useful in the calculation of properties of molecules of such type as A–O–A with the help of Pauling’s electro-negativity scale.
In the Appendix, the numerical values of some overlap integrals between 2s 2p hybrid atomic orbitals and other atomic orbitals are taublated.

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Pressure and stress of monatomic liquid is calculated by a modification of perturbation method in which the boundary of the system is subject to change. If we use the phase space distribution function of Wigner the expression becomes identical to classical stress tensor. The same method applies to the calculation of surface tension. The result is
γ=\frac1A\left[\frac2Tr\left{−\cfrach²2m∑\limits_j=1^N\left(\cfrac∂²∂z_j²−\cfrac∂²∂x_j²\ ight)\ ight}ρ(x,x′)Tr ρ(x,x′)+∫∫\fracx₁₂²−z₁₂²2r₁₂\fracdφ(r₁₂)dr₁₂n(z₁)n(z₂)g(x₁, r₁₂)dx₁ dx₂\ ight]
in which ρ(x, x′) is the density matrix for the states with a definite liquid film with area A perpendicular to the z-axis. The first term represents quantum effect. And the second term is identical in form to the expression obtained by Harasima for classical liquids. It is shown that the relation
γ=∫(P−P_T)dz
holds also for quantum liquid. Here P and P_T are respectively the pressure in the liquid and the pressure component tangential to the surface z=const. Surface effect on ideal gases and comparison with experiments are also discussed.

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Experimental results are reported of the magnetic properties of telluride of cobalt, CoTe_x, where x is the molal content of tellurium. Measurments of the magnetization have been made over a range of temperatures between liquid air and 1150°C. The results of these measurements show that this compound, when stoichiometric, possesses a ferromagnetic character. The value of the saturation magnetization is 7.52 gauss per gram (0.25 μ_B). Evidence was found of a magnetic transition with a sudden disappearance of ferromagnetism at about 1000°C. These characteristic magnetic properties are similar to those of MnAs studied by Guillaud. Increase in tellurium content decreases the saturation moment of this compound, and when x is equal to 1.20 the compound is no longer ferromagnetic but shows a feeble constant paramagnetism which is independent of temperature.

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By using powder pattern technique, the maze-like domain which appears on the mechanically polished surface of Si–Fe crystal was examined. The maze domain was found to be a sort of the closure domain, which transports the magnetic flux of the underlying domains. It was also found that the boundaries between these domains are zigzag-shaped. This is interpreted as a general character of 90° wall. The agreement between theory and experiment is good. The degree of zigzag depends also upon the magnitude of the internal stress. From this relation the internal stresses up to 360 kg/mm² was found in the vicinity of the scratch.

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This first-order transition of Barium Titanate single crystal was observed optically at the Curie point of about 120°C by polarizing microscope, and the domain boundary movement was recorded by 16 mm motion picture. The crystal was so called c-plate, and the area and the thickness were about 0.1 mm² and 0.03 mm respectively. With increasing temperature, no change was observed up to the Curie point, but at about 120°C the domains begin to move rapidly and discontinuously and the heterogeneous transformation of c-plate to a-plate occurs. Then discontinuous and rapid changes of a-plate to cubic phase occur, and the transition is finished. During this transition, we observed some interesting domain patterns, caused by the penetration of two perpendicular domains.

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The ferroelectric single crystal of barium titanate exhibits a strong absorption in the ultra-violet region at any temperature including the three transition points. The threshold for the ultra-violet absorption shifts gradually towards longer wave-lengths as the temperature rises, and the temperature coefficient of it is about one Angstrom per degree centigrade. In addition to this ultra-violet absorption, the crystal exhibits another absorption in the visible region. The intensity of natural light with wave-lengths in the neighbourhood of 5000 A transmitted through the crystal is measured by means of a multiplier phototube. It shows quite steep and sudden changes near the transition temperatures, especially in thin crystals. Let I(T), I(O) and I(R) be the intensity of transmitted light in the tetragonal, orthorhombic and rhombohedral phases respectively. Then the following relations can be drawn out of the various curves for the thermal transition of transparency. They are I(O)\gtrsim\frac12I(T) and I(R)\lesssim\frac14I(T). From calculations on optical paths through the adjacent domains in the orthorhombic phase, the former relation is derived. The same considerations in the rhombohedral phase lead to the latter. Furthermore for polarized light, the behaviours are partially different from those for natural light. In the present paper experimental results for the thermal transition of transparency for both natural and polarized light are interpreted from the standpoints of the theories of ferroelectric domains and crystal optics.

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We have investigated experimentally the photoconductivity of stibnite, a natural single crystal of Sb₂S₃. The results obtained up to the present are as follows:
1. The maximum spectral sensitivity at room temperature is found at the wavelength of 770 mμ and with the rise of temperature it shifts to the longer wavelength side.
2. The photo-current when illuminated by illuminant A varies with half power of the light intensity between 1 and 100 feetcandles.
3. The thermal activation energy for the dark current is 0.48 e.v. between room temperature and 200°C, and temperature dependence of the photo-current is also investigated.
4. The time lag of response is about 3 m sec. for the base photo-current of 10 μA.
5. Moss’s constant, n⁴⁄λ, is calculated to be 82 from our measurements on dielectric constant and refractive index.
6. The crystal is found to be an n-type semiconductor from its rectifying characteristics.
7. The response for X-rays is considerably high, while that for ultra-violet rays, β-rays or γ-rays, is low.

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Triple oxide coatings were studied by means of x-ray powder patterns using a protective film coating technique. Uniform solid solution of the three constituents was not found. Three phases of oxide solid solution were usually found with the heat treatment at a temperature where the preferential evaporation loss of the BaO component does not yet take place. When treated with the temperature above 1000°C, the evaporation loss of BaO became appreciable, causing a remarkable deformation of the shape, and also broadening, of the x-ray diffraction lines. In some cases this line broadening is explained by so-called microstress theory. A possible explanation for the reason of the good emission of the triple oxide cathode is given.

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In the oxide cathode coated with alkaline earth metal oxide on a nickel sleeve, it is generally known that the active material contained in the core significantly influences the thermionic electron emission. That is, the active material produces excess Ba through the reduction of oxide. The produced excess Ba diffuses in the oxide and appears on the cathode surface so as to enhance its thermionic activity. On the other hand, however, nickel sleeve is generally made by drawing method. Because of severe mechanical processings and heat treatments, the surface of the sleeve is subject more or less to contamination. As long as this surface contamination exists, the diffusion of the active material to the sleeve surface is impeded, whereby causing an inferior activity.
The following is the result of research showing the existence of these contaminated layers which exert some evil influences.

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Interferometer measurements are given of pressure distributions of circular-arc airfoils with thickness ratios
10%, 15%, 20%
at angles of attack
0°, 1.6°, 3.2°, 4.8°, 6.4°
in the flow of Mach numbers
0.75, 0.85, 0.95, 1.03, 1.1, 1.2, 1.3, 1.4, 1.55, 1.7, 1.9
with Reynolds numbers based on chord length
2.2∼1.9×10⁵.
From these data, drag coefficients, lift coefficients and pitching moment coefficients were calculated for each case.
These coefficients and lift-angle of attack curves are in good agreement with transonic similarity law. Results are also compared with other wind tunnel experiments.

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In order to study the characteristics of isotropic turbulence produced under various initial conditions and at high Reynolds numbers, hot-wire measurements were made to determine the decay and the g-correlation of turbulence behind two grids, the upstream grid having a larger mesh length than the downstream one, in the 1.5-meter wind tunnel at the Institute of Science and Technology.
The linear decay law, ‾u²∼x⁻¹, does not hold in the presence of a large-scale, slowly-decaying turbulence produced by the first grid ahead of the second grid. On the other hand, Lin’s decay law, ‾u²∼[x⁻¹+const.], which is supposed to be valid for the turbulence either behind a single grid or with a superposed disturbances of low frequencies, is confirmed unless the large-scale turbulence produced by the first grid is overwhelmingly predominant, though the deviation from the self-preservation of correlation at large value of r is marked. The constant term in Lin’s decay law, which expresses the deviation from the complete similarity, is negative for the single grid, but is positive in the presence of a superposed, large-scale turbulence.

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