1. IBM Research Division, Almaden Research Center, 650 Harry Road, San Jose, California 95120; ELORET Inc., 690 W. Fremont, Sunnyvale, California 94087; NASA-Ames Research Center, Moffett Field, California 94035; Department of Chemical Engineering, Sogang University, Seoul, Korea; and Department of Chemistry, Seoul National University, Seoul 151-742, Korea