Firing characteristics of the pitchstone from Yokota Area, Fukushima Pref. were investigated. The results obtained hitherto are as follows:
(1) The chemical analysis of this pitchstone showed that Na₂O content was higher and K₂O content was lower than those in other typical pitchstons.
(2) The H₂O in the pitchstone was more weakly bound than in perlite, and this fact may be one cause for difficulties in good expansion of the pitchstone by firing procedure.
(3) The softening temperature of the pitchstone lowered according as the Na₂O content increased.
(4) On the firing process, the bulk density of the expanded pitchstone decreased according as the firing temperature elevated, and at least the firing temperature of above 1, 200°C was desired. Then for the most suitable firing time it required about 15 sec.
(5) The characteristics of the expanded pitchstone were improved by preheating operation prior to firing process. As conditions of the preheating operation it was required to heat at about 450°C for few minutes, and then the bulk density of the expanded pitchstone decreased to 0.06kg/l under the firing conditione of 1200°C and 15 sec.
(6) The bulk density of the expanded pitchstone decreased according as the Na₂O content increased. From the mechanism of expansion of the pitchstone, it is considered that this facts is due to lowering of the softening temperature.

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Following the theory proposed by Dr. Takagi (Toshiba Reviw, 5, 149 (1950)), sealing characteristics were calculated for composite lead-in wires with copper core. The following items were treated in this paper, i.e. thermal expansion of wire, stresses in glass-to-metal cylindrical seal and stress release in seal by viscous flow of glass, and results were shown graphically. Plasticity and compressibility of copper were taken into consideration.
Experiments on wires with cores occupying about 1/10 of total cross sectional areas showed that effects of copper core on sealing stresses are rather small compared with theoretical estimations. According to the author's opinion, this may be explained by change or lowering of elastic moduli and yield strength of copper at high temperature or by end effect in seals.

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An analytical treatment from the view-point of chemical engineering was made on the reaction zone in the shaft kiln which has been operated almost empirically because of the existence of too many relating factors.
As an example, cement shaft kiln was discussed in this paper with particular attention to the effect of CO loss in the excit gas.
With the use of the available kinetic data on combustion and calcination, and the simplified mathematical model as shown in Eq. (1)-(20), the distribution profiles of temperature and chemical conversion degree of the substance concerned in the direction of kiln axis were calculated numerically using a digital computer.
The rather complex interrelationship of the operating parameters was clarified, taking the effect of CO loss in the exicit gas into consideration, which is a very important factor for the heat consumption of the kiln.
Calculated data were compared with the experimental data obtained by pilot plant (300φ×1500mm), and a corrected factor λ for the effective heat transfer coeff cient was introduced and used in further calculations.
It was found through this study that the influence of operating parameters on the distribution profiles of temperature and chemical conversion degree can be well evaluated quantitatively.

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