1. Laboratory of Ecological Solutions and Sustainable Development of Materials, Faculty of Materials Science and Applied Chemistry, Institute of General Chemical Engineering, Riga Technical University, Pulka 3, K-3, LV-1007 Riga, Latvia
2. Institute of Materials and Surface Technologies, Riga Technical University, P. Valdena iela 7, LV-1048 Riga, Latvia
3. Department of Physics, Faculty of Natural Sciences and Informatics, Constantine the Philosopher University in Nitra, Tr. A. Hlinku 1, 949 01 Nitra, Slovakia
4. Department of Horticultural Machinery, Mendel University in Brno, Valtická 337, 691 44 Lednice, Czech Republic
5. Institute of Plasma Physics of the Czech Academy of Sciences, U Slovanky 2525/1a, 182 00 Prague, Czech Republic