1. Mechanical Engineering Department, Faculty of Engineering, University of Porto, Rua Dr. Roberto Frias 712, 4200-465 Porto, Portugal
2. LAETA, INEGI, ISEP, Instituto Politécnico do Porto, R. Dr. António Bernardino de Almeida, 4249-015 Porto, Portugal
3. LAETA, INEGI, Mechanical Engineering Department, Faculty of Engineering, University of Porto, Rua Dr. Roberto Frias 712, 4200-465 Porto, Portugal