P.O. Pavlovichev – Post-graduate Student, P.G. Demidov Yaroslavl State University E-mail: assault74@rambler.ru

A.L. Priorov – Dr.Sc. (Eng.), Associate Professor, P.G. Demidov Yaroslavl State University

E-mail: andcat@yandex.ru

A.I. Topnikov – Ph.D. (Eng.), Associate Professor, P.G. Demidov Yaroslavl State University E-mail: topartgroup@gmail.com