1. Mechanical Engineering Research Laboratory, Kobe Steel, Ltd., 1-5-5 Takatsukadai, Nishi-ku, Kobe, 651-2271, Japan
2. Coal and Energy Technology Department, Kobe Steel, Ltd., 2-3-1 Niihama, Arai-cho, Takasago, 676-8670, Japan
3. Energy Science Division, EcoTopia Science Institute
4. Department of Mechanical Science and Engineering