A simple case of the temperatures on one side of the specimen and its surroundings being kept constant and the heat flowing through the rod by conduction and transferring at its surface is mathematically analysed. Effect of a thermal damper is discussed. The tem-perature distribution is numerically calculated for glass and iron rods, 0.05cm in radius and 2.5cm in length, in the range of the thermal transfer coefficient of 100_??_10-3 kcal/m2h°C. The smaller the transfer coefficient, the surer and easier the control of the temperature when the heat is conducted through the rod, and the reverse is the case when the heat is transferred from the surroundings to the rod. Care to be taken is given in applying this simple model in practice and the outcome of the calculation is discussed for various methods of heating and cooling.
Effect of rouge and pitch on the polishing of glass are studied. Rouge made from ferrous oxide in an electric hearth at 600°C is superior to other rouges in efficiency. X-ray analysis and electron micrograph do not tell the difference in appearance of surfaces polished with various rouges, but spectral reflectance curves show that a rouge of poor quality as pigment is good for polishing. Fe3O4 (black rouge), CuO, CeO2, TiO2, ZrO2, Cr2O3 etc. are all good, and when mixed with rouge, the efficiency improves. Pitch being of composite constituents, it is not in geneal but an addition of a small quan-tity of resin may give a better polish by increased friction. However, too much resin leaves the “rouge streaks”.
The object of this research is to obtain a high intensity X-ray tube adaptable for an electric apparatus of ordinary capacity (<30mA). In the newly designed X-ray tube, the anode is rotated by induction from a stator outside the tube, and the target is cooled with water through a medium of mercury. The tube has the following characteristics and uses: 1) The tube has no rotating vacuum seal. 2) The capacity of the tube is largest when the filament is set vertical. Therefore this setting is most favorable for obtaining the vertical, rectangular beam as used in Debye-Scherrer cameras. In that case the first slit is dispensable and consequently the time of exposure may be reduced to about 1/50 of that with ordinary fixed-target X-ray tubes. 3) The position of the focal spot is variable on the surface of the target cylinder, hence tithe lifetime of the target cylinder is much longer than that of the non-variable type. 4) The change of target may be made easily and in a short time.
Infrared gas analyzer of double beam and negative filter type was made. Nickel bolometers are used as detectors. The output of A. C. bridge circuit, which is consisted of the nickel bolometers and manganine standard resistances, is amplified through a 4-stage R-C coupled amplifier and then operates the null-balancing system. With three experiments, it was found that the accuracy of this instrument is ±3% for 0_??_250mmHg of CO2. In 5 hours, any appreciable drift of the zero point was not observed, but when the cooling water was recharged the variation was observed to be about ±1%. The deflection of recording was drifted by 0.5% of the full scale, when A. C. line voltage was varied from 85 to 115 V.
Secondary-electron emission surfaces of 1% Mg and 2% Mg-Cu alloys prepared under various oxidizing conditions are studied by electron diffraction method. Surface products identified by this method are plotted on temperature-pressure diagrams defining the oxidizing condition and compared with the yield values of the secondary emission measured simultaneously. The results show that MgO film, which is produced selectively under the oxidizing conditions of temperatures 400°C_??_700°C and of pressures 1×10-4mmHg_??_5×10-2mmHg, gives rise to the high yield values obtainable by Mg-Cu alloys.