Investigating the relationship between the plasticity and the fundamental parameters, F₃, S_a and d_s, the following results were obtained.
1) Relationship between modulus of rupture st and maximum deformation D of wet bodies was expressed by the equation:
D=Jf(st)
J was plasticity index, and f(st), determined by measurement for a typical body, was the term changed with wet strength. When maximum deformation and strength of bodies were known, plasticity index could be calculated from the equation.
2) From the above equation and the already reported equation for wet strength, [maximum deformation-moisture content] curve could be calculated. When the fundamental parameters, the wet strength coefficient, and plasticity index of the body were known, strength and maximum deformation at the moisture content of shaping operations could be estimated.
3) The plasticity index was not only functions of the fundamental parameters, but also affected by higher order factors, such as shape of particles and homogeneity of cast pieces.

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A study has been made for obtaining informations on thermal properties and crystallization process of magnesium phosphate glass with the molar composition MgO⋅P₂O₅. The thermal properties such as linear expansion, DTA figure and specific volume change by heat-treatment of the glass were tested. The crystallization temperature was determined from the DTA, and the crystal growth in the glass specimen heat-treated was observed through a microscope.
From the thermal expansion curve, transformation temperature (glass transition point) (T_g) and softening temperature of the phosphate glass were determined to be 563°C and 595°C, respectively. Linear coefficients of the thermal expansion below T_g(α_l) and above T_g(α_h) were 98×10^-7 and 99×10^-6cm/cm⋅°C, respectively. A wide difference between α_l and α_h can be interpreted in connection with the characteristics of this glass having an open structure.
The DTA curve of the fine powdered glass showed that the crystallization started at 630°C and finished at 698±5°C, which points were determined from the sharp exothermic peak. In the case of the bulky glass sample, it was indicated that the crystallization initiated at about 730°C and completed above 800°C, which temperatures were pointed out by deviation from the basic line in the DTA chart and by the broad exothermic peak, respectively.
The crystallization of the phosphate glass specimen began at its surface. The crystals formed at the surface were observed to be fine granular particles and to be smaller than several microns in size. The size of the crystallite was affected by keeping conditions of the sample, i.e., temperature and time. During the crystallization process at higher temperatures than about 660°C, after the whole surface of the specimen had been filled with fine crystal particles, the crystal growth proceeded inside of the specimen. The X-ray diffraction patterns of both the surface and the inside crystals coincided with that of Mg(PO₃)₂ which is mentioned in ASTM X-ray powder data. The crystals observed inside of the specimen were oriented vertically to the surface, and they were rod-and/or needlelike polycrystals.
The rate of crystal growth proceeding from the surface of the specimen toward its inside in a steady state increased linearly with increasing temperature within the range of 600°C to 700°C. The activation energy of the crystal growth was determined to be 80kcal/mol in the above temperature range.

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It is known that sintered bodies of semiconducting barium titanates or its solid solutions have a large positive temperature coefficient of resistivity above and near the Curie temperature. They have a negative temperature coefficient of resistivity normal as usual semiconductors below the Curie temperature. At the Curie temperature the tetragonal to cubic transition takes place and the resistivity anomaly around the temperature has been related to the transition. At the transition temperature, orthorhombic to tetragonal, however, no anomaly in the resistivity-temperature characteristic has been found on the sintered bodies reported so far.
The present authors modified the texture of sintered bodies of semiconducting barium titanate with bismuth oxide penetrated along grain boundaries. When non-ohmic contact electrodes were applied to the texture modified specimens another anomaly in the resistivity-temperature characteristic appeared above the orthorhombic to tetragonal transition temperature in addition to the anomaly above the Curie temperature. The nonlinear current-voltage and capacitance-voltage characteristics measured on present specimens with asymmetric electrodes (non-ohmic contact electrode to the one side and ohmic contact to the other side), showed the existence of a surface barrier-layer in the interface between the non-ohmic electrode and the body with texture modified. The nonlinear curve in the capacitance-voltage characteristic was not expressed by the relation 1/C²=2(V_d-V)/eε_sN_d (V_d is a built-in voltage at a barrier, ε_s is a dielectric constant in a barrier-layer and N_d is the density of ionized donor centers) above a certain reverse bias which was dependent on a measuring temperature. It seems reasonable to assume that the surface barrier-layer is made up of a inversion layer and a bismuth oxide layer. The barrier gave rise to the anomaly around a room temperature. Under a higher electric field the effect of the surface barrier becomes negligible small compared with the effects by barriers given across the grain boundaries in the sintered body which is considered to give rise to the anomaly above the Curie temperature. It may be considered that by the addition of bismuth oxide the concentration of trap centers changed; the concentration of trap centers affects the height and width of the barrier between semiconducting grains and of the barrier between the non-ohmic electrode and the pellet surface.

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A phase separated sodium borosilicate glass was leached in various leaching conditions and leach out mechanism was conidered. The thickness of the leached layer is proportional to square root of leaching time and the leaching rate is scarcely hindered by saturation of the leached products. The rate is controlled by hydrogen ion diffusion from bulk to the rigid glass through the leached layer. Apparent diffusion coefficient-acid concentration plots have two reflection points at 2 and 6mol% of the acid. This is attributed to change in character of the leached layer. Large amount of inorganic and organic substances also change the nature of the leached layer and reduce the diffusion rate.

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For the purpose of researching into the formation and the color development of tinchrome single spinels, the gradual substitution according to the following formula was carried out for each tin spinel.
Mg²⁺(Zn²⁺)+Sn⁴⁺→←2Cr³⁺
Thus, MgO-SnO₂-Cr₂O₃, ZnO-SnO₂-Cr₂O₃, CoO-MgO-SnO₂-Cr₂O₃, CoO-ZnO-SnO₂-Cr₂O₃, NiO-MgO-SnO₂-Cr₂O₃, NiO-ZnO-SnO₂-Cr₂O₃, CoO-NiO-MgO-SnO₂-Cr₂O₃ and CoO-NiO-ZnO-SnO₂-Cr₂O₃ systems were investigated.
On samples prepared by calcining the oxide mixtures at 1350°C for 1 hour, the X-ray analysis and the measurement of reflectance between 400-760mμ were carried out, and color glaze test was then made. The results were summarized as follows.
(1) Continuous solid solutions of tin and chrome spinel and obedience to Vegard's law except a few instances were confirmed by X-ray analysis. Consequently, single spinels of the color ranging from blue to bluish green or from yellowish green to dark green were obtained.
(2) Deviation from Vegard's law was observed in CoO-ZnO-SnO₂-Cr₂O₃ and NiO-ZnO-SnO₂-Cr₂O₃ systems, owing to the strong coordination preference of Cr³⁺, Ni²⁺ and Zn²⁺ ions.
(3) As the amount of Cr³⁺ ions increased, the absorption of Cr³⁺ ions shifted towards violet region, owing to the construction of octahedral interstices. On the contrary, absorption of Co²⁺ ions did not shift, because the space of tetrahedral interstices were maintained constant.
(4) Accoding the results of color glaze test, spinels with the composition in Cr³⁺ rich region were appreciated to be applicable for pottery.

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Application of Krypton adsorption-desorption isotherm for study of micropore structure of ceramic bodis is suggested. The isotherm provides qualitative information on micropore structure in case of such small pore-diameter that mercury intrusion porosimetry can not be applied and of such small pore-volume that nitrogen adsorption porosimetry can not be applied. Two examples of application are presented. One is oxidation of graphite and the other is sintering of UO₂.

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