The problem of laminar fluid flow, which results from the stretching of a vertical surface with variable stream conditions in a nanofluid due to solar energy, is in- vestigated numerically. The model used for the nano...The problem of laminar fluid flow, which results from the stretching of a vertical surface with variable stream conditions in a nanofluid due to solar energy, is in- vestigated numerically. The model used for the nanofluid incorporates the effects of the Brownian motion and thermophoresis in the presence of thermal stratification. The sym- metry groups admitted by the corresponding boundary value problem are obtained by using a special form of Lie group transformations, namely, the scaling group of transfor- mations. An exact solution is obtained for the translation symmetrys, and the numerical solutions are obtained for the scaling symmetry. This solution depends on the Lewis number, the Brownian motion parameter, the thermal stratification parameter, and the thermophoretic parameter. The conclusion is drawn that the flow field, the temperature, and the nanoparticle volume fraction profiles are significantly influenced by these param- eters. Nanofluids have been shown to increase the thermal conductivity and convective heat transfer performance of base liquids. Nanoparticles in the base fluids also offer the potential in improving the radiative properties of the liquids, leading to an increase in the efficiency of direct absorption solar collectors.展开更多
Friction stir welding(FSW)has been extensively adopted to fabricate aluminium alloy joints by incorporating various welding parameters that include welding speed,rotational speed,diameters of shoulder and pin and tool...Friction stir welding(FSW)has been extensively adopted to fabricate aluminium alloy joints by incorporating various welding parameters that include welding speed,rotational speed,diameters of shoulder and pin and tool tilt angle.FSW parameters significantly affect the weld strength.Tool tilt angle is one of the significant process parameters among the weld parameters.The present study focused on the effect of tool tilt angle on strength of friction stir lap welding of AA2014-T6 aluminium alloy.The tool tilt angle was varied between 0°and 4°with an equal increment of 1°.Other process parameters were kept constant.Macrostructure and microstructure analysis,microhardness measurement,scanning electron micrograph,transmission electron micrograph and energy dispersive spectroscopy analysis were performed to evaluate the lap shear strength of friction stir lap welded joint.Results proved that,defect-free weld joint was obtained while using a tool tilt angle of 1°to 3°.However,sound joints were welded using a tool tilt angle of 2°,which had the maximum lap shear strength of 14.42 kN and microhardness of HV 132.The joints welded using tool tilt angles of 1°and 3°yielded inferior lap shear strength due to unbalanced material flow in the weld region during FSW.展开更多
Soluble fiber-rich fenugreek seeds(Trigonella foenum-graecum)and garlic(Allium sativum)are understood to exert cholesterol-lowering and antioxidant effects.The cardioprotective influence of a combination of fenugreek ...Soluble fiber-rich fenugreek seeds(Trigonella foenum-graecum)and garlic(Allium sativum)are understood to exert cholesterol-lowering and antioxidant effects.The cardioprotective influence of a combination of fenugreek seeds and garlic by their antioxidant influence was evaluated in hypercholesterolemic rats administered isoproterenol.Wistar rats were maintained on high-cholesterol diet for 8 weeks along with dietary interventions of fenugreek(10%),garlic(2%)and their combination.Myocardial infarction was induced with isoproterenol injection.Increased circulatory troponin,disturbed activities of cardiac ATPases,increased serum iron and decreased ceruloplasmin confirmed myocardial infarction.Elevated lipid peroxides accompanied with reduced antioxidant molecules caused by isoproterenol and altered activities of antioxidant enzymes in serum and heart in induced myocardial necrosis were countered by dietary fenugreek,garlic,and fenugreek+garlic.Dietary fenugreek seeds and garlic ameliorated isoproterenol-induced compromised antioxidant status,the cardioprotective effect being higher by the combination of fenugreek seeds and garlic.展开更多
文摘The problem of laminar fluid flow, which results from the stretching of a vertical surface with variable stream conditions in a nanofluid due to solar energy, is in- vestigated numerically. The model used for the nanofluid incorporates the effects of the Brownian motion and thermophoresis in the presence of thermal stratification. The sym- metry groups admitted by the corresponding boundary value problem are obtained by using a special form of Lie group transformations, namely, the scaling group of transfor- mations. An exact solution is obtained for the translation symmetrys, and the numerical solutions are obtained for the scaling symmetry. This solution depends on the Lewis number, the Brownian motion parameter, the thermal stratification parameter, and the thermophoretic parameter. The conclusion is drawn that the flow field, the temperature, and the nanoparticle volume fraction profiles are significantly influenced by these param- eters. Nanofluids have been shown to increase the thermal conductivity and convective heat transfer performance of base liquids. Nanoparticles in the base fluids also offer the potential in improving the radiative properties of the liquids, leading to an increase in the efficiency of direct absorption solar collectors.
基金Aeronautical Development Agency (ADA), Bangalore, India, for the financial support to carry out this investigation through an R&D project No: FSED 83.07.03
文摘Friction stir welding(FSW)has been extensively adopted to fabricate aluminium alloy joints by incorporating various welding parameters that include welding speed,rotational speed,diameters of shoulder and pin and tool tilt angle.FSW parameters significantly affect the weld strength.Tool tilt angle is one of the significant process parameters among the weld parameters.The present study focused on the effect of tool tilt angle on strength of friction stir lap welding of AA2014-T6 aluminium alloy.The tool tilt angle was varied between 0°and 4°with an equal increment of 1°.Other process parameters were kept constant.Macrostructure and microstructure analysis,microhardness measurement,scanning electron micrograph,transmission electron micrograph and energy dispersive spectroscopy analysis were performed to evaluate the lap shear strength of friction stir lap welded joint.Results proved that,defect-free weld joint was obtained while using a tool tilt angle of 1°to 3°.However,sound joints were welded using a tool tilt angle of 2°,which had the maximum lap shear strength of 14.42 kN and microhardness of HV 132.The joints welded using tool tilt angles of 1°and 3°yielded inferior lap shear strength due to unbalanced material flow in the weld region during FSW.
文摘Soluble fiber-rich fenugreek seeds(Trigonella foenum-graecum)and garlic(Allium sativum)are understood to exert cholesterol-lowering and antioxidant effects.The cardioprotective influence of a combination of fenugreek seeds and garlic by their antioxidant influence was evaluated in hypercholesterolemic rats administered isoproterenol.Wistar rats were maintained on high-cholesterol diet for 8 weeks along with dietary interventions of fenugreek(10%),garlic(2%)and their combination.Myocardial infarction was induced with isoproterenol injection.Increased circulatory troponin,disturbed activities of cardiac ATPases,increased serum iron and decreased ceruloplasmin confirmed myocardial infarction.Elevated lipid peroxides accompanied with reduced antioxidant molecules caused by isoproterenol and altered activities of antioxidant enzymes in serum and heart in induced myocardial necrosis were countered by dietary fenugreek,garlic,and fenugreek+garlic.Dietary fenugreek seeds and garlic ameliorated isoproterenol-induced compromised antioxidant status,the cardioprotective effect being higher by the combination of fenugreek seeds and garlic.
