I.N. Kornilov - Ph.D. (Eng.), Associate Professor, Ural Federal University (Yekaterinburg). E-mail: ilya238@rambler.ru N.V. Ergashev - Assistent, Ural Federal University (Yekaterinburg). E-mail: nikerg@rambler.ru

A.V. Zhuravlev – Dr.Sc. (Eng.), Senior Research Scientist, Main Designer – Deputy General Director, JSC SPE «PROTEK» (Voronezh, Russia)

E-mail: protek@protek-vrn.ru

V.G. Markin – Leading Engineer, 

JSC SPE «PROTEK» (Voronezh, Russia)

E-mail: marvigs@mail.ru