1. Department of Materials Science
and Engineering, University of Ioannina, GR-45110 Ioannina, Greece
2. Department of Environmental and
Natural Resources Management, University of Patras, Seferi 2, 30100 Agrinio Greece
3. Physics Department, University of Ioannina, GR-45110 Ioannina, Greece
4. Regional Centre of Advanced
Technologies and Materials, Faculty of Science, Department of Physical
Chemistry, Palacky University in Olomouc, 77146 Czech Republic