The crystallographic orientation of fractured surface in both intergranular and transgranular stress corrosion crackings was examined by changing the angle (θ) between specimen axis and grain boundary on SUS304 coarse columnar crystals with ‹100› growth direction. Intergranular cracking occurs at θ=60° and 90°, transgranular cracking at θ=0°, and both mixed crackings at θ=30° and 45°. Even on specimens fractured at grain boundary, many cracks were also observed in grains. Grain boundaries whose planes are closer to {100} and/or {110} of adjacent crystals have higher susceptibility to cracking. This seems to be closely related to the fact that the susceptibility to transgranular stress corrosion cracking is higher on {100} and {110}.

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In the oil hydraulic system, the internal oil flow in the controlled elements should be analyzed by considering the flow pattern in order to improve the controllability of the system.
In previous paper, the boundary element method was applied to these problems, and the velocity profiles in the hydraulic controlled valve were examined.
In this paper, the velocity profiles in the spool valves of the various shapes were simulated by the boundary element method, and by using the obtained velocity vectors, these steady flow axial forces were calculated and compared. The most suitable shape of the spool valve, which can be improved the controllability of the hydraulic controlled valve of a spool type, was presented.

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Effect of microstructure on load life characteristics of insulation resistance (IR) has been studied with multilayer ceramic capacitors with Ni-electrode. It is found that the formation of oxygen vacancies under the firing in reducing atmosphere and the discrepancy of grain boundary composition from the nominal composition are the causes of the short life time. In case of high oxygen partial pressure at annealing, the formation of oxygen vacancies was suppressed and the IR load life time was prolonged. Donor additives such as Y₂O₃ are also valid to suppress the formation of oxygen vacancies.
The suppression of the formation of oxygen vacancies and the control of grain boundary chemistry were effective to prolong the IR load life time.

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In order to investigate a fabrication process for high strength aluminum=ceramic composites (Al-Al₂O₃, Al-Si₃N₄, Al-SiC), the composites were made by inserting the ceramic rods into molten aluminum at 1173K for various times up to 7.3ks. The relation between the structure and shear strength of the aluminum-ceramics interface in the composites was investigated. The shear strength was determined from resistance for shear deformation at the aluminum-ceramics interface. It was found that except for Al-Al₂O₃, the reaction layers of Al₄C₃ and AIN are formed at the interface regions of Al-SiC and Al-Si₃N₄, respectively and that the strength depends on the thickness and morphology of the rection layers. The optimum strength is obtained by heating at 1173K for 0.9-1.2ks, which is about 3-4 times that estimated for shear strength of alumimum matrix. The strength is higher in order of Al-Al²O₃, Al-Si₃N₄ and Al-SiC.

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Thin films of three layers (p-type/i-type/n-type) amorphous silicon (a-Si:H) and boron phosphide (BP) were investigated by means of Fourier transform infra-red (FTIR) spectroscopy and electron spin resonance (ESR). The formation ratio of (B-H)/(P-H) bonds in BP film, as functions of SiH, and PH₃ gas flows, was evaluated by magnitude of stretching vibration. As for a-Si, higher order bond of-(Si-H₂)-n, which may deteriorate the efficiency of solar energy conversion (ESEC), was distinguishable from Si-H single bond. The number of unpaired electron spins formed in 5 % ESEC a-Si:H, 7.99-1013 (spin/gram), was 73% larger than that in 8% ESEC a-Si:H.

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Effect of process parameters as mixing and firing conditions on the varistor characteristics of BaTiO₃-SrTiO₃-CaTiO₃ system ceramics has been studied with special attention to the micro-and nano-structures. It is shown that well mix ing and control of Po₂ of ambient atmosphere during firing are most effective to attain high α (coefficient of V-I nonlinearity). In case of high Po₂, anomalous grain growth is predominant. On the other hand, in case of low Po₂, uniformly sized grain structure can be observed, but grain growth is insufficient. Adequate grain size and uniform microstructure are required for achieving high α. HRTEM observation showed grain boundary layer for high a ceramics, and facet grain boundary for low α ceramics.

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The resistance of commercial austenitic stainless steel, SUS 304 L, to stress corrosion cracking in a 5% NaOH-2% Na₂S-2% Na₂CO₃-0.2% Na₂SO₄-0.1% NaCl-H₂O solution at elevated temperatures has been studied by immersion tests and electrochemical measurements.
A mixture of intergranular corrosion cracking and transgranular cracking was observed at the fractured U-bend specimen immersed in the test solution at 423K. The effects of solution composition and test temperature on the occurrence of stress corrosion cracking were examined. It was found that both the presence of Na₂S in the solution and the temperature higher than 423 K was necessary to occur stress corrosion cracking and the presence of sodium chloride, sodium carbonate, and sodium sulfate had little effect on stress corrosion cracking occurrence. Cracking of U-bend stressed specimens was found to occur at a potential near the active/passive transition range of SUS 304 L. The results are discussed with reference to electrochemical behavior and the analyses of surface corrosion films.

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The electrical breakdown phenomena in mixtures of n-hexane and acetophenone have been studied using an image converter camera in conjunction with a photo optical current measuring system. It was shown that aspects of streamer development for both polarities in n-hexane are remarkably changed by a small amount additive of acetophenone. With higher additive rate of acetophenone, the negative streamer is changed to be more filamentary than that in plain n-hexane and to resemble the positive streamer in cyclohexane. The results are consistent with models of a breakdown mechanism based on a field ionization process for positive polarity and Auger-like electron emission process for negative polarity.

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The Values of emf of the galvanic cell (+) Mo |Mo (s), MoO₂(s)| ZrO₂(+MgO)| Fe^xO (in slag), Fe |Ag| Fe (-) involving zirconia solid elektrolyte have been measured at 1467K-1641K in order to obtain the activity of Fe_xO in Fe_xO-B₂O₃ system molten slag and the standard free energy of formation of Fe_xO.
Activity of B₂O₃ were also determined by virtue of Gibbs-Duhem integration (α-function integration).
The standard free energy of formation of Fe_xO. was determined as the following equation:
ΔG° (Fe_xO) /kJ·mol^-1=-264.3+0.06486T
Activity of Fe_xO deviates from negative to positive on the N_FexO=0.55 at 1473 K and N_Fe^xO=0.64 at 1573K from Raoult's law, and show constant value, 0.20, independent of temperature over the two liquids phase range below N_FexO=0.48. Activity of B₂O₃ show constant value, 0.65, over the same two liquids phase range and decrease beyond N_FexO concentration, 0.48.

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Measurements have been made by the steady state comparison method for the effective thermal conductivity of the clothing materials which consist of fiber (discontinuous phase) and air (continuous phase or matrix). The influence of the factors affecting the effective thermal conductivity of clothing materials is discussed. The experimental apparatus and the test specimen are inserted into a box which is able to control the humidity or the pressure inside it.
The thermal conductivity increases slightly with temperature for any specific density of clothing materials in the present experimental range in a similar way to that of the air, and it is also increases with the volume fraction of fibre except small fraction range. The effective thermal conductivity is, however, almost independent to relative humidity for cotton cloth and polyester one.
Experimental result are compared to predicting equations for the fibrous materials, and the one which has wider range applicability has not been found from among the existing equations.

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The powder materials are used in various field of industry as raw or intermediate materials. And many kinds of powder unit operation handle these powder materials, but various phenomena of powder have not yet been elucidated sufficiently. Fundamental relationship between powder surface properties and behavior is expected to be discussed as one of important subjects.
In this paper, calcium carbonate is used as test packing powder and powder packing operation is fundamentally discussed. And the effects of powder surface improvement on initial bulk density distribution are experimentally and thermophsically discussed using X-ray radiograph system. As a results of it, the optimum conditions to generate the most homogeneity of powder density distribution is pointed out to exist.

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