1. Institut Laue-Langevin, 71 avenue des Martyrs, CS 20156, 38042 Grenoble Cedex 9, France
2. Institute of Chemistry, Eötvös Lorand University, P.O. Box 32, Budapest 112, Hungary
3. Department of Chemistry, University J. Selyeho, P.O. Box 54, 945 01 Komárno, Slovakia
4. Department of Colloid Chemistry, St. Petersburg State University, Universitetsky pr. 26, 198504 St. Petersburg, Russia
5. Chemical Engineering Department, National Taiwan University of Science and Technology, 43 Keelung Road, Section 4, Taipei 106, Taiwan
6. Faculty of Natural Sciences, Keele University, Staffordshire ST5 5BG, U.K.