1. Transylvania University of Braşov, Romania Bd. Eroilor No. 29, Brasov, RO 500423, Romania
2. Romanian Academy of Technical Sciences, Bdul Eroilor No. 29, Memorandumului Str. No. 8b, RO 500045, Brasov, Romania (Corresponding author), e-mail: csam@unitbv.ro, https://orcid.org/0000-0002-4706-1033
3. Academy of Romanian Scientists, Bdul Eroilor No. 29, Olteniei Str. No. 2A, Brasov, RO 500209, Romania