type: 999_or_102_or_112subjectTerm: II. NATURAL SCIENCES AND AGRICULTURAL SCIENCES_or_I. MATHEMATICS AND COMPUTER SCIENCEauthor: Gitzenis, Savvas_or_Kefalas, Petros_or_Toumpis, Stavros_or_Bertachas, Ioannis_or_Perivolaropoulos, Leandros_or_Kolettis, Theofiloslang: el