S. F. Tyurin - Dr.Sc. (Eng.), Professor, Perm National Research Polytechnic University. Е-mail: tyurinsergfeo@yandex.ru
A. Yu. Gorodilov - Research Scientist, Perm National Research Polytechnic University. Е-mail: gora830@yandex.ru
A. A. Baydarov - Ph.D. (Eng.), Research Scientist, Perm National Research Polytechnic University. Е-mail: cchp@bk.ru