TiO₂ photocatalysts decompose hazardous chemical substances into CO₂ and H₂O under light irradiation. We formed the TiO₂ thin films on the quartz glass plates by RF magnetron sputtering method without heating. After 90-second UV irradiation, the thin films decompose colon bacillus down to 0.1%. Moreover, they absorbed visible light at over 600nm. We tried to pile up these semiconductor films, whose energy gaps are narrower than 3.2eV. TiO₂ thin films absorbed visible light more and caused more efficient photocatalytic reaction. Antibacterial catheters, contact lenses, plastic containers, etc., were prepared by the RF magnetron sputtering without heating.

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The objective of present study is to determine the effect of the tilted angle of dental implants supporting the maxillofacial prosthesis on the stress and strain distribution of the dental implants, abutments and bone. Present authors already determined the stress and strain distribution of the abutment and the superstructure body supported by three implants. In this study, the material properties of bone and titanium were substituted to the 3 dimensional finite element method (3DFEM), then the stress and strain were analyzed. We subsequently discussed the better implant alignment. Finally, a human-friendly implant and a superstructure body having longer life than usual were designed. The result suggested that tilted implants should be designed their tips separating each other like a root of plant.

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Detection method for the closed crack existed in the glass plate using finite amplitude ultrasonic guided wave is described. The received signal is analyzed by the wavelet transform to identify the mode of the guided wave using group velocity dispersion curves. As the results, finite amplitude Rayleigh wave propagation is identified. Using the finite amplitude Rayleigh wave, increase in 6dB of the second harmonic components generated from a closed crack in the glass plate is observed. Rapid increase of the second harmonic component at the condition that width of closed crack, less than 2nm, is equal to the vibration amplitude of Rayleigh wave is also found out. Potential of closed crack detection is clarified by the use of finite amplitude guided wave system.

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Vapor-liquid equilibria (VLE) of hydrocarbon binary systems: hexane + benzene (25°C), toluene + octane (60°C) and cyclohexane + toluene (50°C) were predicted by using a regular solution model. In the present model, the mixing entropy term (Flory-Huggins equation) is included and an interaction parameter between unlike molecules is introduced. Solubility parameters and molar volumes at each temperature required in calculation are estimated by previously proposed methods. VLE of hexane + benzene and toluene + octane were well predicted by introducing no interaction parameter. On the other hand, to correlate VLE of cyclohexane + toluene, the interaction parameter was needed. VLE of hydrocarbon systems may be predicted or correlated by the regular solution model. Previously proposed methods are useful to estimate solubility parameter and molar volume at given temperature.

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