1. Department of Chemical Engineering, Faculty of Engineering, Fukuoka University, Nanakuma Jonanku, Fukuoka 814-80, Japan
2. Tsumura & Company, 3586, Yoshiwara, Amimachi, Inashiki-gun, Ibaraki 300-11, Japan
3. Department of Chemical Engineering, Faculty of Engineering, Pusan National University, Changjeon-tong, Keumjung-ku, Pusan 609-735, Korea