The adsorptive characters of the monovalent cations, Li⁺, Na⁺, in sericite and kaolinite were evaluated from the dissociabilities and the amounts of exchangeable ions in relation to the kind of ions and to the specific surface of the clay minerals. These data were obtained as a contribution to the advanced knowledge of the cationic fixation phenomenon in clay minerals, which has been reported in part I of this series presented in this journal.
For the comparison of the natures of fixation of two clay minerals, the changes in exchangeabilities and in the mean free bonding energies of the ions due to the drying at the temperatures below 600°C, were investigated.
From the obtained experimental results, the newly derived conclusions are summarized as follows:
(1) The monovalent ions held on sericite surface are more liable to dissociate than those held on kaolinite (i, e., less strongly held on sericite than on kaolinite).
(2) The exchangeable cations held on sericite can be fixed nonexchangeably, but less intensively than those held on kaolinite, the phenomenon which may be attributed to the less strong adsorptive power of sericite.
(3) The tendency of fixation in sericite is accelerated with the increase of specific surface by milling.

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セメントとモルタルの配合に関する各種要因がエフロレセンスとこれに関連ある特性におよぼす影響について調べた. エフロレセンスはセメント中のアルカリ量を減じ, またモルタルを緻密にすることによって軽減される. モルタルの吸水, 乾燥および透水の速度は主として水セメント比が低く, 水和度の高いことによって減少する. したがってモルタルを緻密にするために粗目の砂を用い, 添加材として高炉水砕スラグの微粉末を一部セメントに置換して加えることはエフロレンス防止の面でも有効と思われる. ただしモルタルを富配合にすることは同時にアルカリ含有量を高めることになり明らかな効果をもたらさなかった.

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When an easily devitrifing glass including a small amount of metals such as gold, silver, or copper as nucleating agent is subjected to a stepwise heat treatment after being exposed to ultraviolet rays, X-rays, or γ-rays metal colloid separate out which act as nuclei for turning the whole mass into an assembly of minute crystallites. There are other possibilities of obtaining the same structure, i.e. by simple heat treatments making use of the characteristic property which is shown by titanium compounds etc. during the growth of crystals in glass phase. In this case such compounds act as nucleating agents.
It is the purpose of the present paper to form the “devitroceram” of the system CaO⋅TiO₂⋅SiO₂-Li₂O⋅Al₂O₃⋅4SiO₂-Li₂O⋅2SiO₂, to study the possibility of practical use, and based on the exprimental results, to investigate the influence of radiation on the process of devitrification.
For this purpose the glasses of about 20 different compositions (Fig. 1) were melted, which, after being exposed to ultraviolet rays, were subjected to differential thermal analysis, whose results were used to determine the conditions of the heat treatment.
The coefficients of thermal expansion of the devitroceram so obtained were determined, and X-ray analysis was carried out in order to know the nature of crystal phases.
Furthermore, a small number of samples were exposed to the different dosage of ultraviolet-, γ-, and X-rays, which were then given the heat treatment. They were investigated by X-ray analysis and by electronographic morphology in order to throw light on the influence of the different dosage of irradiation on the structure of devitrified mass.
The irradiation of ultraviolet rays seemed to play no important role on the result of thermal analysis, since the exothermic peak at 600°-800°C and the endothermic peak 200°-400°C above it (cf. Figs. 2, 3, 4) remained practically unchanged whether the glass was irradiated or not.
X-ray analysis of devitrified glass showed the existence of β-spodumene, calcium disilicate, lithium silicate and some other crystals (Table 2).
The coefficient of thermal expansion showed a marked fall by the heat treatment. And the nearer the composition came to Li₂O⋅Al₂O₃⋅4SiO₂ the lower was the coefficient, extending even to negative values (Fig. 8). That the expansion of devitroceram is in the same level or lower than that of low expansion glasses would come up to the expectation of the possibility of its practical use.
The results of X-ray analysis disclosed that the difference of the degree of crystallization in proportion to the difference of the dosage of irradiation was existing only in the samples quenched from the first heat treatment (cf. Figs. 9, 10-a, -b, -c, -d), while the samples received the first and second heat treatment gave no difference. The observation under electron-microscope revealed that the larger was the dosage of γ-rays the smaller became the grain size of crystallites. (cf. Fig. 11).

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The new optical glasses of borate system containing rare elements are usually melted in a platinum crucible. As the physical properties in molten state as well as the capacity of melting pot of such new glasses are entirely different from those of ordinary optical glasses the method of stirring which gives the maximum efficiency would be quite different from the conventional type. The authors, therefore, carried out a series of model experiments in order to establish the basic principles of the new method of stirring.
The experiments covered the wide range of viscosity using different types of stirring rods and the mechanisms. And as the criterion of satisfying the conditions of similitude were used the Reynolds and Froude numbers.
From the results of measuring the mixing velocity it was found out that the relation between the number of revolution of stirring rod, N, and the time required for complete mixing, θ, may be expressed as, N^a⋅θ=k, in which the constants a and k increase with increasing viscosity.
For the liquids of the viscosities of 10⁰-10² poises the crank type stirring rod was better by far as compared with the conventional type, propeller type and screw type rods, the fact which was proved also from the results of calculating the mixing energy.
For studying the mixing of the surface and bottom striae the liquids having different densities and surface tensions were put in thin layers to the corresponding points. In this case the crank type rod proved to be most efficient.
Furthermore, the mixing efficiency was improved to some degree by revolving the crucible itself and by changing the depth of immersion of stirring rod.
The conventional method was found to be less efficient for removing the vertical striae standing at the center of the crucible. It was, however, possible to remove rapidly the striae by crank type rod introduced through the furnace top, since this system was possible to increase the number of revolution without rolling up the bubbles.
The results obtained by model experiments were confirmed with success by practical works.

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