Several experiments are carried out to discover the cause of convexed deformation of lapped glass plates. A “Permanently Strained Layer” is formed on a glass surface by lapping. The layer is expansive and tends to increase its area causing convexed deformation of the plate. The layer has compressive stress because of the rest part of the plate resisting the expansion of the layer. The layer has greater refractive index and lower chemical stability than those of the glass substance. These lead to the following theoretical equation. _??_ where _??_: Initial curvature of the glass plate. _??_: Curvature after lapping. T: Thickness of the glass plate. S: Sum of permanent strain for the thickness of the permanently strained layer. c: Depth of the center of S from the surface of the plate. Curvature variations of thin glass plates which were lapped under various conditions are also studied with the result that: The curvature variation of any glass plate, in whatever condition it might be lapped, undergoes a similar progress explainable by the above equation.
Deformation of thin glass plates caused by polishing and chemical action, and the causes of the deformation are studied. When a glass plate is polished, the deformation is convex only in the beginning, becomes concave, its curvature gradually increasing and finally reaching a stationary state. When a surface of a glass plate is treated with acid or caustic soda solution, the deformation is concave. The deformation by polishing or chemical action is the result of formation of “Amorphus Silica Layer” on the glass surface. The layer is contractive and tends to decrease its area, causing concave deformation of the plate. The layer has a tensile stress because the rest part of the glass plate resists the contraction of the layer. The layer has smaller refractive index and higher chemical stability than the rest of the glass substance. From the results of this study including Part (1), a conclusion is drawn that there are two fundamentally different types of wearing actually found on glass surface. One is the wearing due to destruction of material, such as by lapping. This wearing produces a permanently strained layer on the surface. The other is the wearing in the course of which some of elementary constituent of glass are rubbed off the surface leaving an amorphus silica layer.
The electrical conductivity, Hall coefficient and thermoelectric power of semiconductive Bi2Te3 have been measured between 100°K and 650°K. The samples of p type Bi2Te3 and n type Bi2Te3 (Te excess) have been partially degenerated within the present temperature range, so it is necessary to apply Fermi-Dirac statistics for the interpretation of the experimental results. The obtained results are as follows. The Hall mobility parallel to the cleavage plane varies as T-2 for holes. The energy gap is Eo=0.23 eV at 0°K. The effective masses are mn=1.03m for electrons and mp=1.24m for holes. The mobility ratio is about b=1.7. The Hall mobility for electrons in polycrystalline n type Bi2Te3 (Te excess) varies as T-5/2.
The thermal conductivity of semiconductive Bi2Te3 has been measured between 100°K and 400°K. The lattice component of thermal conductivity, κι parallel to the cleavage plane of Bi2Te3 varies in inverse proportion with the absolute temperature, that is κι=6.8×10-2/T watt/cm. deg. The electrical conductivity, thermal conductivity and thermoelectric power of Bi2Te2-Bi3Se3 system have also been measured at room temperature. The minimum of the thermal conductivity lies at the composition of 3Bi2Te3•2Bi2Se3.
The cooling effects of thermojunctionscomposed of p and n type bismuth-tellurides have been studied. Thermoelectric materials used are p and n type Bi2Te3 whose properties are: ρp=0.60×10-3Ω·cm, αp=142μV·deg-1, κp=1.9×10-2W·cm·deg, ρn=0.78×10-3Ω·cm, αn=-179μV·deg and κn=2.0×10-2W·cm-1·deg-1 where ρ: electrical resistivity, α: thermoelectric power and κ: thermal conductivity. The temperature of the cold junction has been measured in vacuum as a function of the temperature of the hot junction. The experimental results show fairly good agreement with what is predicted by a simple theory. The temperature difference of 67 degree has been obtained at a mean temperature of 17°C.
The heat absorbing power at the cold junction has been measured under various loads. The value of coefficient of performance predicted by the theory is shown to agree fairly well with the experimental result. With the thermojunctions that showed a temperature difference of 28 deg. in vacuum, the difference in still air was 23 deg. and the heat absorbed at the cold junction was 0.032 cal. sec-1. The coefficient of performance deduced from the experiment is 11% showing fairly good agreement with the theoretical value of 12%.
The iridescence of the epidermis of Aji (Trachulus Japonics) is studied. There are three or four layers of crystal guanin in the epidermis, the upper two or three layers consist of relatively large and long hexagonal plate crystals (20μ×5μ). They are very thin and relate to the iridescence. The orientation of crystals in each layer is different; each layer reflects light in a particular direction, giving out characteristic iridescent color, thus the epidermis has a colorful appearance. The cause of this iridescence is examined and is concluded to be of the nature of thin film interference. The ground layer is opaque and white and consists of small (6μ×1μ) crystals disposed in fibrous structure screening the underlying tissues and reflecting the light that comes on through the upper iridescent layers.
A convinient rotating mirror camera has been devised as an auxiliary to an A. D. P. (Ammonium Dihydrogen Phosphate) Kerr effect camera of essentially a discontinuous photographing mechanism. The maximum number of rotations of reflecting rotator is 700 r. p. s., the maximum moving speed of image on film is 1 cm/1.15μ. sec., and superposed time on one frame is about 7μ. sec. It is believed that this performance complies with the requirement not only as an auxiliary to A. D. P. Kerr effect camera, but for photographing many high speed phenomena. By the results of photographing a three-gap-spark and an explosion of constantan-fuse, this camera proved to be very accurate in timing. The delaying appearance of the three-gap-spark was plainly caught.
It is very important to estimate the surface concentration of diffused atoms in a diffused layer. As atoms were made to diffuse into a Ge pellet in dry and pure hydrogen gas after KCN treatment. If the depth of diffusion, the sheet resistance and the base resistivity of the pellet are measured with exactness, the true surface concentration of diffused As atoms will be obtained. Since the effect of thermal conversion could not be neglected, the amount of increased thermal acceptors was introduced into the calculation to obtain the relation of the sheet resistance to the surface concentration. For pellets of various resistivities, the values, observed and calculated, are in very good agreement.
Measuring method of magnetostrictive vibration is improved to suit the study of mechanism of magnetization process. The e. m. f. induced in a flat search coil by the longitudinal vibration of a rod is displayed on a C. R. O.. Introducing a marker on the Lissajous' circle by making use of the intensity-modulation technique, the e. m. f. in vector representation is read directly on the screen. It is proved that the locus of this marker, the “resonance circle”, is equivalent to the motional impedance (or admittance) circle. To obtain definite values of the resonance frequency and Q-1 in a certain field independent of exciting procedures, it is necessary to measure them in terms of exciting current or voltage and estimate those values by extrapolating to zero of the current or voltage. The diameter of the “circle” divided by the current at resonance depends only on the field intensity and considered as a measure of the slope of the magnetostriction vs. field curve.