1. Dipartimento SAIFET, Sezione Scienze Fisiche, Università Politecnica delle Marche and CNISM, Ancona, Italy
2. Dipartimento di Fisica, Università degli Studi di Perugia and CNISM, Perugia, Italy
3. Instituto de Física, Universidade de São Paulo, São Paulo, Brazil
4. Institute of Biophysics and Nanosystems Research, Austrian Academy of Sciences, Graz, Austria
5. Institute of Macromolecular Chemistry, Prague, Czech Republic
6. Institut Laue-Langevin, Grenoble, France
7. CNR-INFM and CRS-SOFT, c/o Institut Laue-Langevin, Grenoble, France