V.V. Ivanov1, I.V. Stepanov2, G.S. Voronkov3, A.V. Voronkova4, E.P. Grakhova5

1–5 Ufa University of Science and Technology (Ufa, Russia)

1 ivanov.vv@ugatu.su; 2 stepanov.iv@ugatu.su; 3 voronkov.gs@ugatu.su; 4 voronkova.av@ugatu.su; 5 grakhova.ep@ugatu.su