Creep of white tin single crystal prepared from 99.93 percent tin is studied in a low strain region at 28°C, 0°C and -78°C. The creep progresses as a power of time similar to the result obtained on zinc crystals by Tyndall and others. in respect of this similarity, the author's result is discussed.
Accumulation of charge by electrification of valcanized rubber caused by repeated mechanical shocks reaches saturation at about the 100th shock if the carbon black content is small. With a large amount of carbon black, the charge accumulated at first begins to fall and becomes stationary after about 50 shocks. Amount of charge accumulated per shock rises gradually with the carbon content. But at the 100th shock, it becomes irregular. The measuring apparatus consists of a direct coupled amplifier, an electromagnetic oscillograph, an electromagnet and a pendulum for producing shock. With this apparatus, measurements of the amount and polarity of accumulated charge, the time of origination of the charge, the impulsive elastic modulus etc. are made possible.
From the author's recent experiments, it is concluded that alloyed In-Ge junctions are formed not by diffusion process1) but by recrystallization proces2) of Ge crystals, and on alloyed junction-diodes and-transistors the electric field dependency of their barrier capacitances obey the V-1/2 law at higher reverse bias voltages, so that the alloyed In-Ge junctions are said to be abrupt which is characteristic to them. From the measurements of capacitances, concentrations of donor impurities and mobility of electrons are derived directly. The life-times of minority carriers are calculated from the measurements of space charge widening effects or of the forward current densities of the junctions. The results agree with the data by other prevailing methods and also with the theoretical values of the abrupt junctions. The capacitances are measured directly by an ordinary capacitance bridge and Buntone “Q”-meter at frequencies ranging from 600 KC/s to 3 MC/s, and consequently no frequency dependency is found. The amplitudes of signal a. c. voltages are kept under lOmV. The resistivities of n-type Ge used were 0.3 to 20Ω cm. measured by the four probes method, and their hole lifetimes were 10 to 500 μ sec. obtained by the Valdes' method at room temperatures.
As previously reported, the resultant of the voltage in the moving coil and that in the fixed winding may come near zero irrespective of the wave form of the exciting current, but its reduction to complete zero was not possible on account of probable harmonics which affects very much the controlling accuracy in practice. The influences of the voltage, frequency and wave form of the exciting current are therefore closely studied. The results are that the reduction of the resultant voltage to complete zero could not be attained but that by preceeding adjustment of the control, its position for the minimum voltage remains fixed for any exciting current and also that the detection of displacement is achieved with the accuracy of +0.003mm by using a rectangular wave voltage.
Displacement of the mercury head of a mercury thermometer can easily be converted into the change in high electric resistance of 20-150 kΩ by using the writer's new recording type mercury thermometer which is made of a capillary with carbon film of about 5μ in thickness deposited on the inside wall enabling the resording or automatic controlling of liquid temperature to be made easy and simple. The thermometer is acid-proof, and is suited for plating baths. A durable and compact temperature controlling unit has been constructed in which a devised combination of a bridge circuit and a thyratron tube is used to function within a pre-arranged range of the resistance. With a BZ-RX type on-off micro switch, the accuracy of the unit is within ±0.1°C. Fineness of the control is such that a turn of 40 degrees in angle of the variable resistance of 20kΩ for adjusting the control corresponds to 1 degree C of the temperature variation.
The ultrasonic absorption for many binary liquid systems, nitrobenzen-hexane, nitrobenzen-fuel oil, nitrobenzen-transformer oil, methylalcohol-hexane, ethylalcohol-fuel oil, methylethyl-keton-liquid paraffin, acetone-transformer oil, which have the upper critical solution temperature, has been measured by the pulse technique at the frequencies 0.98, 1.98, 3.00, 5.00, 6.00, 7.02, 9.02, 10.0, 11.0, 14.0MC. From the concentration, temperature and frequency dependence of absorption coefficient it is made clear that the contribution of clusters to the absorption is for almost all systems the greatest at the concentration for which the solubility curve shows maximum and becomes smaller as the temperature rises, and the relaxation frequencies due to the clusters are in or near the range of frequencies employed.
Structure of thin barium films deposited on glass and polished copper plates under varied air pressures is investigated by electron diffraction. Ba pattern appears for a certainty with 1_??_2×10-5 mmHg vacuum. The orientation of Ba depends on the distance between the Ba source and the base plate. At 15_??_20mm, (110) planes are parallel to the base surface, but at about 7mm, (111) planes become parallel to the latter as observed by W. G. Burges. With the vacuum of around 1×10-4 mmHg, the pattern changes into a few haloes which are inferred as due to an intermediary between Ba and BaO.