In 0.5mol/l NaOH aq. solution, stable P-T region of chrysotile was determined and also solubility of silica from chrysotile up to 500°C and 800 atm was measured by chemical analysis of the solution after the hydrothermal reaction. This stable region extended by about 40°C higher than the region determined by Bowen and Tuttle where chrysotile coexisted with brucite in pure water. In the extending region, however, serpentine after the reaction was fine powder but not fiber, and then the reaction condition in this region would be not suitable for synthesis of chrysotile fiber.
The solubility of silica from chrysotile was not only extremely lower than that from qualtz, but also effect of pressure on the solubility was quite different from the case of qualtz, the solubility having decreased as increasing pressure. Concrening to the both chrysotile and qualtz in 0.5mol/l alkali solution, the effect of temperature on the solubility of silica component was reversed at about 70% fill of water in bomb, the solubility on the low density range of this point having increased as decreasing temperature. Desolution energy of chrysofile which was calculated from the solubility with van't Hoff's equation concided with the value deduced from thermodynamic data.

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Melting and crystallization phenomena of cobalt olivine were observed by DTA and the crystal growth was examined with four shapes of platinum crucible in the Bridgman technique.
Crystallization proceeded at the temperature of about 1410°C, 10°C lower than the melting point. However, the beginning temperature of crystallization was remarkably influenced by the condition of heat treatment of specimen.
Single crystal was grown only a few times. The crystallographic c-axes of grown crystals were predominantly parallel to the direction of crystal growth. When the rate of growth was 0.5-1.8mm/hr, better results were obtained in the case of the crucible of which conical bottom of 60° was bended, although the c-axes of grown crystals were not necessarily parallel to the direction of crystal growth. The crucible having smaller diameter than 4mm could not be used, because pores or voids were easily developed within the grown crystals.

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The effect of the pre-heat-treatment on the kinetics of graphitization of carbon has been investigated. The starting material was a coke prepared from polyvinylchloride by heating it to 680°C in flowing nitrogen (PV-7). Four samples having different pre-heat-treatment conditions were selected; the original coke PV-7, the second one prepared from PV-7 by the heat treatment at 1500°C for 60 min (PV-15), the third also from PV-7 by the treatment at 2060°C for 60 min (PV-7-20), and the fourth by the heat treatment of PV-15 at 2060°C for 60 min (PV-15-20). Each sample was heat-treated in a high purity graphite crucible at temperatures ranging from 1800°C to 2400°C for a variety of residence time under reduced pressure of 0.01-0.02 Torr. In this heat treatment, the temperature of the graphite crucible was raised up to 1700°-2100°C in the first 30 sec, and then increased gradually so as to reach the designed temperature within 2 min. The temperature variation after the set-up was detected by an optical pyrometer not to exceed ±20°C. The c₀-spacing of the heat-treated samples was determined from the (004) X-ray diffraction line by referring to the inner standard of silicon.
For the all samples examined, the c₀-spacing has been found to decrease with increasing the residence time. The relationship between c₀-spacing and residence time was analyzed in the same way as employed by Fischbach for the analysis of the kinetics of graphitization (Nature, 200, 1281 (1963)); The method consists of shifting the curves of c₀-spacing vs. logarithm of residence-time at any heat treatment temperature (T) so as to form a master curve. The effective activation energy can be evaluated by plotting the amount of such shifts against 1/T. Because of the scatter of the experimental data and of some ambiguity in forming the master curve, the effective activation energy has roughly been determined with inevitable uncertainty of 20-50kcal/mol. It has been found, however, that the carbon sample pre-heat-treated at the higher temperature has the higher effective activation energy. In addition, the repeated heat treatments of one specimen have been found to produce the same effect on the change of the c₀-spacing as the continuous heat treatment, if the total residence time equals with each other.

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Self-diffusion of sodium ions in the system of Na₂O-2SiO₂-xAl₂O₃ glasses has been measured for x values from 0.1 to 1.2 in the temperature range from 200°C to 650°C by means of a radio-isotope tracer technique employing ²²Na. The electrical conductivity of the glasses has also been measured.
The discontinuous changes of diffusion coefficients, electrical conductivities and their activation energies at Al/Na=1 have been discussed with respect to the change of glass structure in terms of the oxygen-coordination numbers of aluminium ions. Calculation of correlation factor (f) has been carried out for the modified Nernst-Einstein equation, D/σ=(kT/Ne²)⋅f. The resultant correlation factors of about 0.2-0.3 have been interpreted to be due to diffusion of sodium ions by a vacancy or indirect interstitial mechanism. The absence of abrupt change of the correlation factor with variation of the Al/Na ratio has been discussed for possibility of a single predominant diffusion mechanism.

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Alkali halide single crystals were grown by the Bridgman-Stockbarger method. For visual observation, transparent crucible and furnace or furnace with a viewing window were used. Their growth processes were observed using a reading telescope. Immediately after crystallization starts, the boundary between the melt and the growing crystal rapidly rises because of a fast crystallization due to supercooling of the melt. After that, the boundar yis lowered slowly due to decrease in the crystallization rate, reaches at the lowest position, and rises again. The lower crucible-lowering rate gives a longer distance of the boundary rise. Lowering of boundary occurs at the conical portion of the crucible. The lowest position of the boundary is lowered with increasing the crucible-lowering rate.

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