1. Energy
and Environmental Division, Korea Institute of Ceramic Engineering and Technology, 233-5 Gasan-dong, Guemcheon-gu, Seoul 153-801, Korea
2. School
of Advanced Materials Science and Engineering, Sungkyunkwan University, Gyeonggi-do 440-746, Korea
3. Department
of Chemical Engineering, Yonsei University, Seoul 120-749, Korea
4. Department
of Materials and Component Engineering, Dong-Eui University, Busan 614-714, Korea