1. Department of Chemistry, Kyung Hee University, 1 Hoegi-dong, Dondaemoon-gu, Seoul 130-701, Korea, Division of Environment and Process Technology, Korea Institute of Science & Technology, Hawolgok-dong, Sungbuk-gu, Seoul 136-791, Korea, and Department of Chemical Engineering, Yonsei University, 134 Sinchon-dong, Seodaemoon-gu, Seoul 120-749, Korea