1. Institute of Nuclear Sciences “Vinča,” University of Belgrade; Mike Petrovica Alasa 12-14 11001 Belgrade Serbia
2. Development department, SGL Carbon; Meitingen Germany
3. Faculty of Mechanical Engeneering; University of Maribor; Smetanova 17 2000 Maribor Slovenia
4. Institute of Microbiology and Immunology, School of Medicine, University of Belgrade; Dr. Subotića-starijeg 1 11000 Belgrade Serbia