Some engineering properties of sunflower seed and its kernel, Shahroodi variety as a case study, were investigated at various moisture content levels （3-14% d.b.） for three size categories （large, medium and small...Some engineering properties of sunflower seed and its kernel, Shahroodi variety as a case study, were investigated at various moisture content levels （3-14% d.b.） for three size categories （large, medium and small）. With increase of moisture content from 3 to 14% d.b., all the main dimensions （length, width and thickness）, geometric mean diameter, porosity, true density, terminal velocity and static coefficient of friction increased while bulk density and rupture force for both sunflower seed and its kernel decreased for all size categories. The results showed that the highest value of static coefficient of friction for both seed and kernel was on the rubber surface, followed by plywood, polyethylene, galvanized iron, and finally aluminium surfaces. The seeds required less compressive force to dehull when loaded under the horizontal as compared to the vertical orientation. But for kernels, the trend was the opposite. Also, the compressive forces needed to initiate rupture of sunflower seed hulls were higher （47.1-94.72 N） than those required to rupture the kernel （8.5-13.4 N） in both orientations.展开更多
The present work is devoted to the bending problems of prismatic shell with the thickness vanishing at infinity as an exponential function. The bending equation in the zero approximation of Vekua＇s hierarchical model...The present work is devoted to the bending problems of prismatic shell with the thickness vanishing at infinity as an exponential function. The bending equation in the zero approximation of Vekua＇s hierarchical models is considered. The problem is reduced to the Dirichlet boundary value problem for elliptic type partial differential equations on half-plane. The solution of the problem under consideration is constructed in the integral form.展开更多
文摘Some engineering properties of sunflower seed and its kernel, Shahroodi variety as a case study, were investigated at various moisture content levels （3-14% d.b.） for three size categories （large, medium and small）. With increase of moisture content from 3 to 14% d.b., all the main dimensions （length, width and thickness）, geometric mean diameter, porosity, true density, terminal velocity and static coefficient of friction increased while bulk density and rupture force for both sunflower seed and its kernel decreased for all size categories. The results showed that the highest value of static coefficient of friction for both seed and kernel was on the rubber surface, followed by plywood, polyethylene, galvanized iron, and finally aluminium surfaces. The seeds required less compressive force to dehull when loaded under the horizontal as compared to the vertical orientation. But for kernels, the trend was the opposite. Also, the compressive forces needed to initiate rupture of sunflower seed hulls were higher （47.1-94.72 N） than those required to rupture the kernel （8.5-13.4 N） in both orientations.
文摘The present work is devoted to the bending problems of prismatic shell with the thickness vanishing at infinity as an exponential function. The bending equation in the zero approximation of Vekua＇s hierarchical models is considered. The problem is reduced to the Dirichlet boundary value problem for elliptic type partial differential equations on half-plane. The solution of the problem under consideration is constructed in the integral form.
