1. Faculty of Mechanical Engineering, Petroleum-Gas University of Ploiesti, Boulevard Bucharest, No. 39, Ploiesti 100680, Prahova, Romania e-mail:
2. Faculty of Mechanical Engineering, Military University of Technology, 2 Gen. Kaliskiego Street, Warsaw 00-908, Poland e-mail:
3. Department of Built Environment, Myers Technology Center, College of Technology, Indiana State University, Terre Haute, IN 47809 e-mail: