I.K. Belova - Ph. D. (Phys.-Math.), Kaluga branch of the Bauman MSTU E.O. Deryugina - Ph. D. (Eng.), Kaluga branch of the Bauman MSTU A.V. Ermolenko - Post-graduate Student, Kaluga branch of the Bauman MSTU. E-mail: syvorova_eo@mail.ru