The non-linear behavior of reinforced concrete members have been pursued experimentally by many researchers and Clough-model and Takeda-model are perceived to be working models to describe the non-linear behavior. However, still remains a room where the possibility to enhance the damping capacity of reinforced concrete members are pursued by applying exquisite model such as Degrading Tri-linear model. In this paper, results of experiment are reported which cover the difference in yielding type (shear yielding or flexural yielding) material strength. Emphasis is placed in the range of deformation prior to the yielding of reinforcing bars. The test results are compared with proposed models and it is concluded that Takeda model keeps firm precedence and Degrading Tri-linear model should be excluded on the reason of its over estimate of damping capacity in the smaller deformation range.

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The motion of wind-blown sand grains was photographed by a high-speed digital imaging camera in a large blow-off type wind-tunnel under realistic conditions. Well-sorted sands taken from a natural beach and sieved with median diameters (d₅₀) of 0.15, 0.25, 0.52, 0.68 mm were employed. The horizontal component of the flying sand grain velocity, ū_s, was slower than wind speed, u at the same elevation. Above the certain height from the sand surface, the sand velocity became nearly to the wind velocity with the height. These results yielded the following empirical equation; ū_s/u=0.168ln(z/d₅₀)-0.139 (z; height from the sand surface). For the sand with a median diameter of 0.68 mm (U=11.8m/s), the approximate values of 2.0 m/s and 10-20 degrees were obtained for the falling velocity and angle, respectively, and 1.0 m/s and 20-50 degrees for the rebound velocity and angle, respectively.

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Hydrogen production with glucose by using co-immobilized cultures of a fungus, Rhizopus oryzae NBRC5384, and a photosynthetic bacterium, Rhodobacter sphaeroides RV, in agar gels was studied. The co-immobilized cultures converted glucose to hydrogen via lactate in a high molar yield of about 8moles of hydrogen per glucose at a maximum under illuminated conditions.

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This paper summarizes the recent results in laser-induced magnetization dynamics, in particular, the direct nonthermal opto-magnetic excitation of spin systems in GdFeCo metallic film. Using an all-optical pump and probe technique, we have investigated the temperature dependence of the ultrafast magnetic response in a perpendicularly magnetized ferrimagnetic amorphous GdFeCo thin film. This ferromagnetic film shows large temperature dependence of magnetic resonance frequency. When the temperature of the sample approaches the angular momentum compensation point, both frequency and the Gilbert damping parameter of the magnetization precession increase significantly. By turning the sample into a multidomain state and thereby suppressing the observation of the heating effect of light, we succeeded to measure an ultrafast nonthermal excitation of spin waves with a phase that depends on the angular momentum of the photons. Moreover, the magnetization could be reversed in a reproducible manner by single 40 fs circularly polarized laser pulses, without an external magnetic field. The direction of this opto-magnetic switching is determined only by the helicity of light pulse. These findings open new insights into the understanding of ultrafast magnetic excitation and may provide new prospects for applications of ultrafast opto-magnetic phenomena in magnetic storage and spintronic technology.

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