1. Department of Chemical Engineering; University of Florida; Gainesville FL 32611 USA
2. Materials Science and Technology Division; Oak Ridge National Laboratory; Oak Ridge TN 37831 USA
3. National Renewable Energy Laboratory; Golden CO 80401 USA
4. Analytical Sciences, Dow Chemical Co.; Midland MI USA
5. School of Chemical Engineering; Yeungnam University; Gyeongsan 712-749 Korea