%0 Journal Article %T Approbation of mathematical model of introduction in a tree trunk of an age drill %A Klyuev, G.. %K mathematical model, age auger, friction-slip %J Actual directions of scientific researches of the XXI century: theory and practice %D 2014 %N 2 %P 3 %I FSBE Institution of Higher Education Voronezh State University of Forestry and Technologies named after G.F. Morozov