1. WCU Department of
Energy Engineering, Hanyang University, Seoul 133-791, Republic of Korea
2. School of Biology
and Chemical Engineering, Jiangsu University of Science and Technology, Zhenjiang 212003, China
3. Department of Materials
Science Engineering, Hanyang University, Seoul 133-791, Republic of Korea
4. Department of Materials
Science and Engineering, University of Florida, Gainesville, Florida 32606, United States
5. Department of Energy
and Mineral Resources Engineering, Sejong University, Seoul 143-747, Republic of Korea