1. Department of Chemical and Biomolecular Engineering, Center for Energy and Environment Engineering, Korea Advanced Institute of Science and Technology (KAIST), 373-1, Guseong-dong, Yuseong-gu, Daejeon 305-701, Republic of Korea
2. Department of Applied Chemistry and Biotechnology, Hanbat National University, San 16-1, Dukmyoung-dong, Yuseong-gu, Daejeon 305-719, Republic of Korea