Thermocapillary deformations of an ultra-thin liquid film caused by temperature distribution were threedimensionally analyzed using the unsteady and linearized long wave equation considering the temperature and film thickness dependence of surface tension. The temperature and film thickness dependence equation for the surface tension of a liquid was firstly established. The temperature dependence of the surface tension was obtained experimentally using a surface tensiometer and the film thickness dependence was obtained theoretically from the corrected van der Waals pressure equation for a symmetric multilayer system. Time evolutions of depression and groove of the ultra-thin liquid film caused by local heating were obtained quantitatively.

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This paper deals with one of the applications of the Semi-Active Oil Damper system, which applies base isolation systems reducing the maximum acceleration. The theory of the Semi-Active Oil Damper system is based on Karnopp Theory. The theory has been actually now in use for a Semi-active suspension system of the latest Shinkansen (New trunk lines) trains to improve passenger’s comfortable riding. Various experiments have been conducted using a single mass model whose weight is 15 ton on the shaking table. This model is supported by the rubber bearing. The natural frequency is 0.33Hz of this system. Two Semi-Active Oil Damper were installed in the model and excited the table for one horizontal direction. The maximum damping force of each Semi-Active Oil Damper used for the model is 4.21 kN. The damper can change the damping coefficient by utilizing two solenoid valves. Therefore, the dynamic characteristic of the damping force has two modes. One is a hard damping coefficient and the other is a soft one. It was confirmed that the maximum acceleration of the Semi-Active Oil Damper system can be reduced more than 20% in comparison with the passive Oil Damper system in our tests.