Grain production is one of the Ukrainian agro-industrial complex main branches. An indicator of the grain production efficiency is its profitability. It is characterized by significant annual fluctuations that induce risk. Redistribution of existing grain crops areas taking into consideration their profitability can bring to increase of production efficiency. The paper observes Markowitz’s opti...

ÐConsider a ceramic in an environment, corroding gradually by a surface reaction. When in addition subject to a mechanical load, the ceramic loses mass preferentially at grain-boundary grooves where stress concentrates, so that atomistically sharp cracks may nucleate. Before becoming a crack, a groove maintains local equilibrium at its root; after, it loses local equilibrium. The crack further ...

Wood shrinks anisotropically as it loses hygroscopic moisture. While longitudinal shrinkage (parallel to the grain) is nearly negligible in normal wood, transverse shrinkage (across the grain) is significant and characterized as tangential and radial shrinkage. The application of average tangential shrinkage values to a rectangular cross section results in errors, especially for boards cut from...