To apply adhesion joint for the real steel structures, physical degradation factors of adhesion joints havebeen investigated.In this study, following two physical degradation factors have been considered. The first factor is the fatigue damage induced by earthquakes and winds. The second factor is the fatigue damage induced by thermal stress due to the change of temperature. Based on the above two factors, fatigue test conditions have been determined. Results of the fatigue tests show that this adhesion joint was not destroyed by not only fatigue cycle corresponding with 90 year life but also about 1.5 times adhesion shear stress occurred by the above damage factors in real steel structure. In addition, the experimental samples which were chemically damaged have been also supplied for fatigue tests, where in these samples were deserved for 90 years shown in the first report, and its reliability have been also confirmed. As a result, it has been shown that the adhesion joint has are liability to confirm over 90 years that was necessary for long-life houses.

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The effects of electrical treatment on the residual strength of joints bonded with an electricallydisbonding adhesive have been investigated experimentally.The adhesive can be separated by applying electric current.The ARCAN experimental setup was used to measure the residual strength of the joints subjected to multiaxial combined loads after applying current. The results show that thedecrease ratio of the residual strengths dose not depend on the direction of radial loading when the current-carrying conditions are kept the same. It depends on the areal density of total charge passing through the interface rather than applied voltage. The two results give a prediction method of the residual strength based on the initial strength under combined stress conditions and the areal densityof total passing charge. In Order to verify the prediction method, experiments of a simple separationmodel having spring mechanism were carried out.The model could be separated by applying currentand the separation could be predicted by this method very well.

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Trypsin was covalently immobilized onto the surface of porous chitosan beads with and without alkyl chain spacers of different lengths.The relative activity (RA) of the immobilized trypsin wasfound to the high toward a small ester substrate, p-toluene sulphonyl-L-arginine methyl ester (TAME), but rather low toward casein, a high molecular weight substrate.Trypsin immobilized withspacer gave an almost constant activity by varying the surface concentration in marked contrastwith the immobilized trypsin without spacer whose activity monotonously decreased with decreasingsurface concentration.RA of the immobilized trypsin for hydrolysis of a high molecular weight substrate was a strong function of spacer length.The thermal and strage stabilities of the immobilized trypsin were higher than those of the free trypsin. The trypsin immobilized directly onto the surface of chitosan beads without any spacer gave a higher stability than those immobilized with spacers.The spacer effect on the activity could be explained interms of flexibility of the immobilized trypsinmolecule.

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