1. Fakultät für Physik, Universität Wien, Strudlhofgasse 4; 1090 Wien Austria
2. Department of Biological Physics, Eötvös University; Budapest Hungary
3. Inst. Adv. Materials and Processes ZMP, Univ. Erlangen-Nürnberg; Fürth Germany
4. Nanotube Research Center, National Institute of Advanced Industrial Science and Technology (AIST); 305-8565 Tsukuba Japan