N.V. Cherkesova1, G.A. Mustafaev2, A.G. Mustafaev3

1,2 Kabardino-Balkarian State University (Nalchik, Russia)

3 MIREA – Russian Technological University (Moscow, Russia)

1 natasha07_2002@mail.ru, 2 zoone@mail.ru, 3 mustafaev@mirea.ru