1. Faculty of Aerospace Engineering, Polytechnic University of Bucharest, 1-7 Polizu Street, 1, Bucharest 011061, Romania e-mail:
2. Faculty of Applied Chemistry and Materials Science, Polytechnic University of Bucharest, 1-7 Polizu Street, 1, Bucharest 011061, Romania e-mail:
3. Acoustics and Vibrations Laboratory, National Research and Development Institute for Gas Turbines—COMOTI, 220D Iuliu Maniu Avenue, 6, Bucharest, Romania e-mail:
4. Gas Turbine Special Equipments, Physics and Mechanical Testing Laboratory, National Research and Development Institute for Gas Turbines—COMOTI, 220D Iuliu Maniu Avenue, 6, Bucharest, Romania e-mail:
5. Physical and Chemical Laboratory, National Research and Development Institute for Gas Turbines—COMOTI, 220D Iuliu Maniu Avenue, 6, Bucharest, Romania e-mail: