1. Associate Professor, School of Mechanical Engineering, National Technical Univ. of Athens, 15780 Athens, Greece (corresponding author).
2. Research Associate, Laboratory of Applied Thermodynamics, Dept. of Mechanical Engineering, Aristotle Univ. of Thessaloniki, 54124 Thessaloniki, Greece.
3. Professor Emeritus, School of Mechanical Engineering, National Technical Univ. of Athens, 15780 Athens, Greece.
4. Research Associate, School of Mechanical Engineering, National Technical Univ. of Athens, 15780 Athens, Greece.