1. Assistant Professor, Dept. of Civil, Chemical and Environmental Engineering, Polytechnic School, Univ. of Genova, via Montallegro 1, 16145 Genova, Italy (corresponding author).
2. Professor, Dept. of Civil, Chemical and Environmental Engineering, Polytechnic School, Univ. of Genova, via Montallegro 1, 16145 Genova, Italy.