1. Department of Materials and Applied Chemistry College of Science and Technology Nihon University 1-8-14, Kanda Surugadai, Chiyoda-ku Tokyo 101-8308 Japan
2. National Institute of Technology Miyakonojo College 473-1, Yoshio, Miyakonojo Miyazaki 885-8567 Japan
3. Takachiho Shirasu Co. Nakakirishima 1719, Yamada, Miyakonojo Miyazaki 889-4602 Japan