As in the preceding reports, the effect of irradiation in raising the starting potential on a low pressure Ar-Hg discharge tubes has been studied experimentally. This effect of irradiation is quenched completely by adding a small amount of H2 gas, which is expected to destroy metastable atoms of Hg. This effect depends strongly on the Ar pressure and electron emission of the cathode. Without Ar, Hg discharge tube is very sensitive to λ 2537 radiation in lowering the starting potential. It seems that the destruction of metastable mercury molecules by irradiation is occuring and that these metastables are important for starting just as they are important for the function of the low current discharge in Hg-rare gas mixtures.
The wolframite ((Fe, Mn)WO4) cleavage faces oxidized in open air have been inspected by means of electron diffraction. It is shown that oxidation of wolframite commences at about 460°C. Over the range of 460°_??_1000°C the oxidation product is always hematite (α-Fe2O3) alone; no oxides of manganese and tungsten are observed. The crystallites of hematite grow always epitaxially on the substrate. Many crystallographical planes developed on the cry-stallites are analyzed. In addition, possible explanations for many irrational spots observed in the diffraction patterns are put forward.
The dependency of the characteristic quantities of the circuit such as two trigger levels and output voltage upon the circuit constants is calculated, and, inversely, the method and the accompanying conditions in obtaining the circuit constants by given chacteristic quantities are analized. Comparing with experimental data, it is shown that this method is useful in rough designing.
The following two problems are concerned: the first, the evaluation of errors in the data obtained when the area of the sample is smaller than the cross-sectional area of the illumi-nating beam in the integrating sphere of Hardy spectrophotometer; the second, the propriety of specifying the colour of pearls by the calculated colour tolerance of the data, the possi-bility of colour-classification of pearls is suggested. Although the effect due to the spherical shape of pearls is discussed in part, the rest of the prblem and particularly the influences on the colour determination caused by intense colours of interference seem too early to be taken up at the present stage.
As already reported by the authors, if ordinary photovoltaic cells are made perfect moisture-proof, as by vacuum sealing, the drop in sensitivity will be prevented for many years. Instead of vacuum sealing, which requires a delicate and hard processing, imbedding of cells in transparent polyester resin is tried with a name “imbedded photocell” given to the products by the authors. The maximum exothermic temperature in this process is about 45°C which does not harm the cell. After ten months of continued exposure to 100% humidity and also, in another experiment, after four months of immersion in water, the cell showed no indication of drop in sensitivity. Angular errors in sensitivity, the deviations from the values given by cosine law, are within 15%.