1. Professor, Dept. of Innovation Engineering, Univ. of Lecce, Via Per Arnesano, 73100 Lecce, Italy.
2. Ph.D. Student, Dept. of Innovation Engineering, Univ. of Lecce, Via Per Arnesano, 73100 Lecce, Italy.
3. Leading Researcher, Institute of Polymer Mechanics, Univ. of Latvia, 23 Aizkraukles St., Riga LV-1006, Latvia (corresponding author).
4. Ph.D. Student, Institute of Polymer Mechanics, Univ. of Latvia, 23 Aizkraukles St., Riga LV-1006, Latvia.