1. Polytechnic Institute of Jassy Department of Macromolecular Chemistry Jassy, Bul. Copou, 11, R-6600 Jassy, Romania
2. C. R. I. S. M. A. Interdisciplinary Research Center for Advanced Medical Systems University of Siena Le Scotte, Siena, Italy
3. Polytechnic Institute of Bucharest Faculty of Chemical Engineering Bucharest, Romania