Authors
Adrian Bărbulescu
University of Petrosani, Petrosani, Romania
Ciprian coandreș
University of Petrosani, Petrosani, Romania
Charles Rostand Mvongo Mvodo
Technical University (Engineering) Cameroun, Yaounde, Cameroon
Alexandru A. Burian
University of Petrosani, Petrosani, Romania
Alexandra Lihoacă
University of Petrosani, Petrosani, Romania