1. Department of Nuclear and Fluid Mechanics, University of the Basque Country (UPV/EHU), Vitoria-Gasteiz, Spain
2. Automatic Control and System Engineering Department, University of the Basque Country UPV/EHU, Vitoria-Gasteiz, Spain
3. Reasearch and Development Department, Sunsundegui S.A. Polígono Ibarrea, Navarra, Spain