1. Research Fellow of the Japan Society for the Promotion of Science, Department of Chemical Science and Engineering, Graduate School of Engineering Science, Osaka University, 1‐3 Machikaneyama‐cho, Toyonaka‐shi, Osaka 560, Japan
2. Department of Chemical System Engineering, Faculty of Engineering, The University of Tokyo, 7‐3‐1 Hongo, Bunkyo‐ku, Tokyo 113, Japan
3. Division of Chemical Engineering, Department of Chemical Science and Engineering, Graduate School of Engineering Science, Osaka University, 1‐3 Machikaneyama‐cho, Toyonaka‐shi, Osaka 560, Japan