1. Fakultät für Physik und Geowissenschaften, Universität Leipzig, Linnéstr. 5, D-04103 Leipzig, Germany, Chemical Engineering Department, University of Florida, P.O. Box 116005, Gainesville, Florida 32611-6005, Chemical & Biomedical Engineering Department, Cleveland State University, 2121 Euclid Avenue, Cleveland, Ohio 44115-2214, and Institute of Chemical Technology, Universität Stuttgart, 70550 Stuttgart, Germany