INDEX: A Piggy-Back Satellite for Advanced Technology Demonstration

This paper describes outline of the piggy-back satellite INDEX for demonstration of advanced satellite technologies as well as for a small scale science mission. INDEX satellite will be launched in 2002 by Japanese H2-A. The satellite is mainly controlled by the high-speed, fault-tolerant on-board RIes processor (three-voting system of SH-3). The attitude control is a compact system of three-axis stabilization. Although the size of INDEX is small (50Kg class), several newly-developed technologies are applied to the satellite system, including silicon-on-insulator devices, variable emittance radiator, solar-concentrated paddles, lithium-ion battery, and GPS receiver with all-sky antenna-coverage. These technology developments will be applied to Japanese scientific space exploration in future

Inference of Current density on Microstructure of Electroplated Cu Thin Film

In this paper, we report micro-structural characteristics of electroplated Cu thin films with the variation of the current density applied during the electroplating process. We evaluated the surface roughness, the crystalline texture, the resistivity, and the grain size of the thin film in a wide range of current density (50― 1000A/m2). The surface roughness and the resistivity were increased according to the increment of the current density. The textured structure was also pronounced as the current density was increased. The scanning ion microscope (SIM) image of the cross-sectional samples revealed that grain size of the film prepared in a high current density was much smaller (0.05～0.5μm) than that of the thin film in a low current density (l～2μm). These results are different from the film prepared by a sputtering process, where a smooth surface was observed in a small grain-sized (<0.1μm) film

Seismic Performance of Reinforced Concrete Buildings in Thimphu, Bhutan

Inspite of its location in one of the most active seismic zones in the world, Bhutan has no seismic design code of its own and no detailed study on the performance of buildings under expected earthquake ground excitation has been carried out. In this study, probabilistic seismic hazard analysis is first carried out to predict the design ground motions in Thimphu, Bhutan for the return periods (RPs) of 475 and 2475 years. These ground motions are then used to assess the performance of three typical RC buildings in the capital city, Thimphu. Soil–structure interaction (SSI) is incorporated at different soil sites and the effects of SSI are discussed. Adequacy of using Indian Seismic Code in Bhutan is also studied and discussed. The study suggests that the typical buildings in Bhutan could undergo moderate to severe damages under the 475 year RP and could even collapse under the 2475 year RP ground motions. This study is the first such effort in predicting the design ground motions and then assessing the performance of the general building stocks in Bhutan. The result can guide the seismic preparedness of the country through proper design and mitigation measures