[1] Tomsk State Univ, Fac Mech & Math, Dept Theoret Mech, Tomsk 634050, Russia
[2] Tomsk Polytech Univ, Inst Power Engn, Tomsk 634050, Russia
[3] Firat Univ, Fac Technol, Dept Mech Engn, TR-23169 Elazig, Turkey
[4] Univ Babes Bolyai, Dept Math, Cluj Napoca 400084, Romania