The so-called Dupre-Gamo equation is the result of a mistake in the analysis of the forces acting on a drop of liquid placed on a plane surface. The proposers of the Dupre-Garno equation neglected the existence of the vertical reaction of the solid and consequently all their conclusions were wrong. The neglecting of the solid "reaction" in the common textbooks representation of Young equation can be the origin of this mistake.

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Polysilsesquioxane having methacryloyloxy groups (MPPSQ) was employed for the preparation of hardcoating film on polyethylene terephthalate (PET). The film was readily formed under UV irradiation of MPPSQ, in which the copolymerization with methyl methacrylate also proceeded readily to give the transparent films. In addition, the films were analogously prepared from the multi-functionalized polysilsesquioxanes having both glycidyl and methacryloyl groups (MP-co-GPPSQ). These organic-inorganic hybrid films showed the improved properties on the resistance to scratch and weatherproof quality in comparison with the organic one prepared from dipentaerythritol hexaacrylate. However, the decrease of adhesion forces to PET was observed in the hybrid films containing a higher ratio of the polysiloxane component. In the measurements of contact angle, the lower values under 60° were recorded on the hybrid films obtained from MP-co-GPPSQ.

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The stress variations in butt adhesive joints of dissimilar hollow cylinders under impact tensile loadings are analyzed in elastic and elasto-plastic deformation using a finite element method. The FEM code employed is DYNA3D. The effects of Young's modulus ratio between the dissimilar adherends and the adhesive thickness on the stress variation at the interface are examined. In addition, the process in rupture at the interface of the joint is analyzed. The stress distributions of the jointsunder static loadings are also analyzed by FEM. The characteristics of the stress variations of the joints underimpact loadings are compared with those of the joints under the static loadings. Also, the joint strengths under impact and static loadings are estimated. As the results, It isfound that the maximum value of the maximum principal stress s1occurs at the outside of the lower interface to which an impact loading is applied. The characteristics of the joints subjected to the impact loadings are found to be opposite to those subjected to the static loadings. In addition, the experiments were carried out to measure the strain response of the butt adhesive joints under impact tensile loads using strain gauges. Furthermore, the joint strengths under impact and loadings were measured. Fairly good agreements are observed between the numerical and the measured results.

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