1. Department of Environmental Technology and Urban Planning, Graduate School of Engg., Nagoya Institute of Technology, Gokiso-cho, Showa-ku, Nagoya 466-855, Japan
2. Department of Material Science and Engineering, Meijo University, Tempaku-ku, Nagoya 468-8502, Japan
3. Nanotechnology Research Lab, Birla College, Kalyan 421-304, India