1. 'Politechnica' University, Faculty of Industrial Chemistry and Environment Engineering, Timisoara, Romania + National Institute for Research and Development in Electrochemistry and Condensed Matter, Timisoara, Romania
2. 'Politechnica' University, Faculty of Industrial Chemistry and Environment Engineering, Timisoara, Romania
3. Banat's Agricultural Science University, Faculty of Agriculture, Timisoara, Romania
4. National Institute for Research and Development in Electrochemistry and Condensed Matter, Timisoara, Romania + 'Aurel Vlaicu' University of Arad, Romania