The carbonation of calcium silicate compounds constituting hydrated cement was investigated individually. The samples of xonotlite, tobermorite (2 species), C₃S and β-C₂S, synthesized from pure chemicals, were carbonated by 100% CO₂ gas at gas state (gas reaction), or at wet state of added 100% water (liquid reaction). Reaction rates and the fraction of calcite in CaCO₃ were determined by X-ray quantitative analysis. Species and degree of crystallinity of the carbonation products were examined by X-ray diffraction method and infra-red absorption method.
The results obtained are as follows:
1) The carbonation of hydrated calcium silicates proceeds rapidly, the rate determining process is a surface reaction. The difference of reactivity between xonotlite produced in higher temperature and tobermorite in lower temperature, and in tobermorites of different crystallinity are observed. The reaction products are CaCO₃ and silica gel, and CaCO₃ is almost crystalline, the morphologic habit is calcite both in gas reaction and in liquid reaction.
2) The carbonation of anhydrous calcium silicates proceeds more slowly than that of the hydrated compounds, but more rapidly compared to that of anhydrous calcium aluminates The reactivity of β-C₂S is higher than that of C₃S in the carbonation, but the reverse is in the hydration. This fact is seen significant to resolve a reaction mechanism in the carbonation. The special feature of CaCO₃ produced in the reaction of the anhydrous compounds is distinguished from that of the hydrated compounds, that is predominant of amorphous and differnt morphologic habit.

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Gas chromatography appeares to be particulary suitable for the analysis of gas bubbles in glass.
The paper describes the results obtained by the author in the use of gas chromatography which has a thermal conductivity cell as a detector, a column of tri-cresylphosphate on Chromosorb W for the separation of CO₂, H₂S, SO₂, and a column of molecular sieve 5A for O₂, N₂, CO.
With this apparatus it is possible in one operation to separate and analyse the gases in a bubble in the order CO₂, O₂, N₂, H₂S, SO₂, CO within 25 minutes.
The minimum volume of gas that can be detected are as follows:
O₂ 0.01μl (at n.t.p)
N₂ 0.01
CO₂ 0.02
CO 0.2
H₂S 0.7
SO₂ 1.3

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The electric conductivities of the molten oxide system PbO-B₂O₃-Fe₂O₃ were determined over the temperature range from liquidus to 1000°C, and the role of ferric ion upon the mechanism of conduction was discussed.
The samples containing Fe₂O₃ 0 to 25 mol% were quenched when their conductivities had been measured. Most of the samples formed glass, and the glasses were heat treated to be crystallized. Measurements of Infra-red Spectra and X-ray diffraction were made on the glasses quenched or crystallized to understand the structure of glass in relation to complex borates.
The results were as follows.
(1) Specific conductivity increases with temperature, and obeys the Arrhenius equation. The values of the apparent activation energies for conduction are about 10 to 20kcal/mol, and are in the same order as in the system PbO-B₂O₃. Specific conductivities are of the order of 1 ohm^-1cm^-1 at 1000°C, and increase with the PbO content. From these results, it is considered that the conduction in this system is ionic and electric charge is carried mainly by the Pb²⁺ ion.
(2) The activation energy for conduction depends upon the structure of the complex borate anion, the presence of the ring borate anion giving higher activation energy.
(3) The ferric ion has a tendency to form complex anions such as Fe₂O₅⁴⁺ in this system, and the concentration of the free Fe³⁺ ion is small and it contributes little to conduction.
(4) The structure of the complex borate anion is related to the formation of the complex ferrite anion.

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It was pointed out that the application of the concept of the partial molar volume to a non-ideal solution such as glass lead to erroneous results.
When the partial molar volume of component molecules will be discussed in connection with their structures, the continuity of partial molar volume must be discarded and the increment of molar volume of a solution must be expressed through equations which contain not only partial molar volumes but also their increments with molarity, owing to the fact that the change of molarity can not be made infinitely small. As an immediate consequence of these results, partial molar volumes of component molecules vary independently with each other as their molarities are changed.
Because of the complicated nature of the change of partial molar volumes with composition in case of non-ideal solutions, it will be worthwhile for such solutions to be converted into ideal solutions through an appropriate selection of complex groups of these solutions as their components.
After such conversion it will become easy to get the value for partial molar volumes which has meanings for estimation of structures of components.
Two examples of this conversion method, each for a chalcogenide glass and for an alkali-borate glass, are shown with good results.

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The so called “Mo-Mn Process” is one of the methods for forming ceramic-to-metal hermetic seals by metallizing, nickel plating and succesive hard-soldering.
High alumina (94wt% Al₂O₃) ceramic discs and Kovar parts were sealed together by the process. Tensile strengths of sealing layers were measured. The layers were examined by opical and scanning type electron microscope and by electron probe microanalyzer.
The results were as follows:
1) Tensile strengh of the sealing layers was the highest when the ceramics were metallized at 1450°C for 60minutes.
2) The sealing layers were formed by many layers which were arranged in the following order;
Ceramic-Intermediate layer-Metallizing layer-Ni plating layer-Hard solder-Ni plating layer-Kovar.
The intermediate layer was composed of Al₂O₃, MnO and MgO together with small amounts of SiO₂ and CaO. Main crystalline phase in the layer was MnO⋅Al₂O₃. The thickness of the layer was proportional to that of the adjacent metallizing layer.
3) Pores in the Mo-Mn metallizing layer were filled with glass phase and nickel; the former came out from ceramic and the later from nickel-plating layer. Infiltration and interdiffusion of these materials formed strong and vacuum-tight sealing layers.

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The authors investigated the hydration of aluminous cement manufactured by the burning process, especially investigated the relationship between the process of heat evolution of the aerated cement and the including SO₃.
SO₃ in the burned aluminous cement clinker remains in the form of calcium sulfoaluminate [3(CaO⋅Al₂O₃)⋅CaSO₄], and it influences the rate of hydration when the cement is aerated.
The results obtained are summerized as follows;
(1) Both aluminous cement A which contains 0.7% of SO₃ and B which contains 0.2% equally had the heat of hydration value 77cal/g, but the time of exothermic peak of A cement delays about 30 to 60 mins. in comparison with B and the pattern on the rate of heat evolution of A changed after aeration, too.
(2) Investigating chemical contents of the solution extracted from neat paste mixed for 5 mins., the solubility of A cement changed by aeration from 1, 690 to 990mg/l in Al₂O₃, 1, 140 to 950mg/l in CaO, 0 to 20mg/l in SO₃. In addition, the X-ray figure of the precipitated material changed from β-2CaO⋅Al₂O₃⋅8H₂O plus 3CaO⋅Al₂O₃⋅CaSO₄⋅12H₂O to 3CaO⋅Al₂O₃⋅CaSO₄⋅12H₂O plus 3CaO⋅Al₂O₃⋅3CaSO₄⋅32H₂O.
(3) In the case of synthesized 3(CaO⋅Al₂O₃)⋅CaSO₄ the rate of heat evolution is also influenced like A cement by aeration.

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