The amount of photo-electron emittion is very sensitive to the material and it's surface status. The relation between the amount of photo-electron emission and oxidation was studied. As the results, it was found that there is good correlation between the reduction rate of photo-electron emission from the bare surface and the oxidation rate of materials. The reduction rate of photo-electron emission from the bare surface was dependent to the humidity in the air. A new defect can be detected by scanning the photo-electron sensor with X-Y stage. The time required for aluminium to reach the maximum exo-electron emission after the bare surface was formed, t_max, was independent the wave length of light. But t_max increased with decreasing air pressure.

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In order to elucidate the microkinetics of hydrogen assisted cracking of low alloy steel, a newly developed Acoustic Emission (AE) source inversion system was used. The paper discusses the feasibility and some problems in applying this system to monitor the kinetics of microcrack. The AE monitoring system is composed of displacement type transducer, preamplifier, high speed A/D converter and 32 bit personal computer. The transfer function of AE measuring system was carefully examined and found to measure the surface displacement without giving wave distorsion up to 1.5MHz. A computer software for AE source inversion procedure made it possible to calculate the second kind Green's function (transfer function of material) and also to simulate the surface displacement at sensor position and calculate the source waves from detected waves by convolution integral in time domain and deconvolution integral in frequency domain respectively. The energy released by step wise crack propagation was obtained by the deconvolution of detected waves with the overall transfer function of the system which was experimentally determined by pencil lead breaking at notch tip. The crack size was calculated from relieased energy with the assistance of fracture mechanics, and found to fairly well agree with the hydrogen induced intergranular fracture area at early time. Though the propriety and accuracy of the informations from source wave have to be carefully examined by more experiments of large specimens, it could be said that the AE source inversion procedure could give more direct informations on the microkinetics of environmental assisted cracking.

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Current fluctuations of a stainless steel under anodic polarization in sodium chloride solutions were measured and analyzed statistically. The frequencies of the fluctuations were decreased with time after the polarization and the probability of the fluctuation was predicted by an exponential function which suggested that all the events were independent of each other. The rate of pit embryos formation decreased with increasing polarization potential. The rate of passivation (death probability of embryos), the mean life time and the peak current of the fluctuations did not clearly depend upon the polarization potential and the concentration of chloride.

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Impedance measurements of copper electrodes in a low-conductivity water (less than 10μS/cm) with the addition of either benzotriazole (BTA) or phenyl-amino-triazine-dithiol (PTD) were performed. BTA inhibits copper corrosion better than PTD. Corrosion inhibition with PTD occurs only at concentrations above 10ppm. A combination of BTA and PTD proved more effective than either used alone. The optimum ratio is 3ppm BTA+2ppm PTD with the total amount of inhibitor 5ppm.

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New structural materials designed or developed for nuclear facilities including a light water reactor, fast breeder reactor, high temperature gas cooled reactor, fuel reprocessing facility and fusion reactor have been reviewed. Corrosion problems of materials used in the environments such as water, nitric acid solution, liquid metals, and high temperature inert gas are especially discussed.

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As amorphous materials are characterized by atomic disorder, amorphous semiconductors have unique electrical and optical properties such as localized states, mobility edges, states in the gap arising from structural defects, variable-range hopping conduction, and optical absorption. The properties of amorphous semiconductors depend on the deposition method and its deposition conditions because amorphous materials are in non-equilibrium state. While deposition methods using neutral radical species are well known, methods using ion species are recently being considered. Since the discovery of hydrogenated amorphous silicon with structural sensitivity, a new and wide field from basic science to applications to large-area electronic devices has been opened. The basic properties, deposition methods and applications of amorphous semiconductors, particularly hydrogenated amorphous silicon are summarized.

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