TY JOUR TI DETERMINATION OF THE CELL WALLS DENSITY OF THE WOOD AND OTHER POROUS MATERIALS BY GAS PYCNOMETRY IN ATMOSPHERIC AIR KW wood KW density of wood cell walls and porous materials KW volume of a porous body KW gas pycnometry KW atmospheric air JO Forestry Engineering Journal AU Gaynullin, R.H. AU Safina, A.. AU Gaynullin, R.H. AU Cvetkova, E.M. PY 2021 IS 11 PB FSBE Institution of Higher Education Voronezh State University of Forestry and Technologies named after G.F. Morozov