TY JOUR TI Crack formation in natural and pressure-modified silver birch (Betula pendula Roth) wood: the effect of the internal friction index under the influence of external disturbances KW internal friction of wood KW diagnostics of cracks in wood KW natural and modified wood KW drooping birch (Betula pendula Roth) KW ultrasound KW pulsed magnetic field JO Forestry Engineering Journal AU Russu, A.V. AU Shamaev, V.A. AU Zimelis, A.. PY 2023 IS 13 PB FSBE Institution of Higher Education Voronezh State University of Forestry and Technologies named after G.F. Morozov