1. University of Pitesti; Faculty of Electronics, Communications and Computers Science; 1 Targu din Vale, Arges 110040 Pitesti Romania
2. University Politehnica of Bucharest; Doctoral School; Bucharest Romania
3. Gazi University, Faculty of Technology; Department of Electrical and Electronics Engineering; 06500 Teknikokullar, Ankara Turkey
4. King Mongkut's University of Technology North Bangkok; Renewable Energy Research Centre (RERC); Bangkok Thailand
5. National Center for Hydrogen and Fuel Cell National Research and Development; Institute for Cryogenics and Isotopic Technologies, ICIT; Ramnicu Valcea Romania