1. Department of Mechanical System Engineering, University of Hyogo, 2167 Shosha, Himeji, Hyogo 671-2201, Japan
2. Research Center for Material Cycles and Waste Management, National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba, Ibaraki 305-8506, Japan
3. Environment Preservation Center, Kyoto University, Yoshida-Honmachi, Sakyo-ku, Kyoto 606-8501, Japan