1. Department of Chemical and Pharmaceutical Sciences, University of Trieste, 34127 Trieste, Italy
2. Tito Scalo (PZ) and Trieste LD2 Unit, ISM-CNR, 34127 Trieste, Italy
3. Department of Physics and Astronomy, Uppsala University, Box 516, SE-751 20 Uppsala, Sweden
4. IOM-CNR, Laboratorio TASC, Sincrotrone Trieste, I-34149 Trieste, Basovizza, Italy
5. Science Department, University of Basilicata, 85100 Potenza, Italy