1. School of Agrarian and Veterinary Sciences, Universidade de Trás-os-Montes e Alto Douro, Vila Real, Portugal
2. Department of Physics, School of Science and Technology, Universidade de Trás-os-Montes e Alto Douro, Vila Real, Portugal
3. Institute for Systems and Computer Engineering, Technology and Science (INESC TEC) and the Faculty of Sciences, University of Porto, Porto, Portugal