1. Department of Environmental Materials Engineering, National Institute of Technology (KOSEN), Niihama College, 7-1 Yagumo-cho, Niihama, Ehime 792-8580, Japan
2. Hyogo University of Teacher Education, 942-1 Shimokume, Kato, Hyogo 673-1494, Japan
3. Graduate School of Science and Technology, Nara Institute of Science and Technology, NAIST, 8916-5 Takayama, Ikoma, Nara 630-0192, Japan