1. Max-Planck-Institut für Intelligente Systeme, Heisenbergstr. 3, D-70569 Stuttgart, Germany
2. Department of Chemical Engineering, City College of the City University of New York (CUNY), 140th Street and Convent Avenue, New York, New York 10031, United States
3. Department of Mechanical Engineering, University of Hawai’i at Ma̅noa, 2540 Dole Street, Holmes Hall
302, Honolulu, Hawai’i 96822, United States
4. IV. Institut für Theoretische Physik, Universität Stuttgart, Pfaffenwaldring 57, D-70569 Stuttgart, Germany