1. Department of Innovation Engineering, University of Salento, Lecce, Italy
2. Department of Mathematics and Physics “Ennio De Giorgi”, University of Salento, Lecce, Italy
3. CNR NANOTEC - Istituto di Nanotecnologia, Lecce, Italy
4. Department of Structural and Geotechnical Engineering, Sapienza University of Rome, Rome, Italy