1. Engineering Department; Vasile Alecsandri University of Bacau; 157 Calea Marasesti RO-600115 Bacau Romania
2. Department of Materials Science; Tallinn University of Technology; Ehitajate tee, 5 EE-19086 Tallinn Estonia
3. Faculty of Physics and Engineering; Moldova State University; 60 A. Mateevici MD-2009 Chisinau Republic of Moldova
4. Ghitu Institute of Electronic Engineering and Nanotechnologies; Academy of Sciences of Moldova; Academiei, 3/3 MD-2028 Chisinau Republic of Moldova
5. Alexandru Ioan Cuza University of Iasi; Carol I, 11 RO-700506 Iasi Romania