The Experts below are selected from a list of 174 Experts worldwide ranked by ideXlab platform
S V Prabhu - One of the best experts on this subject based on the ideXlab platform.
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experimental investigations on two and three stage modified savonius rotor
Wind Engineering, 2011Co-Authors: M A Kamoji, Shireesh B. Kedare, S V PrabhuAbstract:Single stage modified Savonius rotor (without shaft) is having higher Coefficient of power (0.21) compared to single stage conventional Savonius rotor (0.17). Coefficient of static torque is negative for a 1/6th of a cycle from rotor angle 135° to 165° and from 315° to 345°. There is a large variation in the Coefficient of static torque in a cycle of 180° from a peak of 0.44 at 30° to a lowest value of -0.21 at 165°. Multi-staging provides Positive Coefficient of static torque at all rotor angles and reduces large variations in a cycle. Wind tunnel tests were conducted to assess the aerodynamic performance of two and three stage modified Savonius rotors without shaft in between the end plates at different rotor aspect ratios and stage aspect ratios. The Coefficient of static torque variations decrease with the increase in the number of stages. However, the Coefficient of power decreases with the increase in the number of stages. The effect of intermediate plates on the performance of rotors is also studie...
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Performance tests on helical Savonius rotors
Renewable Energy, 2009Co-Authors: M A Kamoji, Shireesh B. Kedare, S V PrabhuAbstract:Conventional Savonius rotors have high Coefficient of static torque at certain rotor angles and a negative Coefficient of static torque from 135° to 165° and from 315° to 345° in one cycle of 360°. In order to decrease this variation in static torque from 0° to 360°, a helical Savonius rotor with a twist of 90° is proposed. In this study, tests on helical Savonius rotors are conducted in an open jet wind tunnel. Coefficient of static torque, Coefficient of torque and Coefficient of power for each helical Savonius rotor are measured. The performance of helical rotor with shaft between the end plates and helical rotor without shaft between the end plates at different overlap ratios namely 0.0, 0.1 and 0.16 is compared. Helical Savonius rotor without shaft is also compared with the performance of the conventional Savonius rotor. The results indicate that all the helical Savonius rotors have Positive Coefficient of static torque at all the rotor angles. The helical rotors with shaft have lower Coefficient of power than the helical rotors without shaft. Helical rotor without shaft at an overlap ratio of 0.0 and an aspect ratio of 0.88 is found to have almost the same Coefficient of power when compared with the conventional Savonius rotor. Correlation for Coefficient of torque and power is developed for helical Savonius rotor for a range of Reynolds numbers studied.
S Finch - One of the best experts on this subject based on the ideXlab platform.
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Plasma pyridoxal phosphate and pyridoxic acid and their relationship to plasma homocysteine in a representative sample of British men and women aged 65 years and over.
The British journal of nutrition, 1999Co-Authors: Christopher J. Bates, Kristina Pentieva, Andrew M. Prentice, Mohammad Azam Mansoor, S FinchAbstract:Concentrations of pyridoxal phosphate and pyridoxic acid were measured in fasting plasma samples from British men and women aged 65 years and over, participating in a National Diet and Nutrition Survey during 1994–5, selected to be representative of the population of mainland Britain. In this population, the concentration of pyridoxal phosphate declined, whereas pyridoxic acid rose, with increasing age and frailty; however, both status indicators were strongly and directly (with a Positive Coefficient) correlated with estimates of vitamin B 6 intake. This was little affected by the inclusion of food energy and protein intakes in the model. Forty-eight percent of the participants living in the community and 75% of those living in institutions had plasma pyridoxal phosphate concentrations below a range considered normal from other studies. In a univariate regression model, plasma pyridoxal phosphate concentrations were inversely correlated with plasma homocysteine concentrations, consistent with the hypothesis that vitamin B 6 status may influence plasma homocysteine levels, and hence vascular disease risk. However, this relationship was partly attenuated in a multiple regression model including age, sex, domicile and biochemical status indices, including those of folate and vitamin B 12 . There was evidence that plasma pyridoxal phosphate was sensitive to metabolic conditions associated with inflammation and the acute-phase reaction, and that plasma pyridoxic acid was sensitive to renal function. Thus, neither index is an ideal predictor of vitamin B 6 status in older people, unless these confounding factors are allowed for. Since poor vitamin B 6 status may have health implications, e.g. for immune function, cognition, and for essential intermediary metabolic pathways in older people, it needs to be investigated as a possible public health problem.
M A Kamoji - One of the best experts on this subject based on the ideXlab platform.
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experimental investigations on two and three stage modified savonius rotor
Wind Engineering, 2011Co-Authors: M A Kamoji, Shireesh B. Kedare, S V PrabhuAbstract:Single stage modified Savonius rotor (without shaft) is having higher Coefficient of power (0.21) compared to single stage conventional Savonius rotor (0.17). Coefficient of static torque is negative for a 1/6th of a cycle from rotor angle 135° to 165° and from 315° to 345°. There is a large variation in the Coefficient of static torque in a cycle of 180° from a peak of 0.44 at 30° to a lowest value of -0.21 at 165°. Multi-staging provides Positive Coefficient of static torque at all rotor angles and reduces large variations in a cycle. Wind tunnel tests were conducted to assess the aerodynamic performance of two and three stage modified Savonius rotors without shaft in between the end plates at different rotor aspect ratios and stage aspect ratios. The Coefficient of static torque variations decrease with the increase in the number of stages. However, the Coefficient of power decreases with the increase in the number of stages. The effect of intermediate plates on the performance of rotors is also studie...
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Performance tests on helical Savonius rotors
Renewable Energy, 2009Co-Authors: M A Kamoji, Shireesh B. Kedare, S V PrabhuAbstract:Conventional Savonius rotors have high Coefficient of static torque at certain rotor angles and a negative Coefficient of static torque from 135° to 165° and from 315° to 345° in one cycle of 360°. In order to decrease this variation in static torque from 0° to 360°, a helical Savonius rotor with a twist of 90° is proposed. In this study, tests on helical Savonius rotors are conducted in an open jet wind tunnel. Coefficient of static torque, Coefficient of torque and Coefficient of power for each helical Savonius rotor are measured. The performance of helical rotor with shaft between the end plates and helical rotor without shaft between the end plates at different overlap ratios namely 0.0, 0.1 and 0.16 is compared. Helical Savonius rotor without shaft is also compared with the performance of the conventional Savonius rotor. The results indicate that all the helical Savonius rotors have Positive Coefficient of static torque at all the rotor angles. The helical rotors with shaft have lower Coefficient of power than the helical rotors without shaft. Helical rotor without shaft at an overlap ratio of 0.0 and an aspect ratio of 0.88 is found to have almost the same Coefficient of power when compared with the conventional Savonius rotor. Correlation for Coefficient of torque and power is developed for helical Savonius rotor for a range of Reynolds numbers studied.
Shireesh B. Kedare - One of the best experts on this subject based on the ideXlab platform.
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experimental investigations on two and three stage modified savonius rotor
Wind Engineering, 2011Co-Authors: M A Kamoji, Shireesh B. Kedare, S V PrabhuAbstract:Single stage modified Savonius rotor (without shaft) is having higher Coefficient of power (0.21) compared to single stage conventional Savonius rotor (0.17). Coefficient of static torque is negative for a 1/6th of a cycle from rotor angle 135° to 165° and from 315° to 345°. There is a large variation in the Coefficient of static torque in a cycle of 180° from a peak of 0.44 at 30° to a lowest value of -0.21 at 165°. Multi-staging provides Positive Coefficient of static torque at all rotor angles and reduces large variations in a cycle. Wind tunnel tests were conducted to assess the aerodynamic performance of two and three stage modified Savonius rotors without shaft in between the end plates at different rotor aspect ratios and stage aspect ratios. The Coefficient of static torque variations decrease with the increase in the number of stages. However, the Coefficient of power decreases with the increase in the number of stages. The effect of intermediate plates on the performance of rotors is also studie...
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Performance tests on helical Savonius rotors
Renewable Energy, 2009Co-Authors: M A Kamoji, Shireesh B. Kedare, S V PrabhuAbstract:Conventional Savonius rotors have high Coefficient of static torque at certain rotor angles and a negative Coefficient of static torque from 135° to 165° and from 315° to 345° in one cycle of 360°. In order to decrease this variation in static torque from 0° to 360°, a helical Savonius rotor with a twist of 90° is proposed. In this study, tests on helical Savonius rotors are conducted in an open jet wind tunnel. Coefficient of static torque, Coefficient of torque and Coefficient of power for each helical Savonius rotor are measured. The performance of helical rotor with shaft between the end plates and helical rotor without shaft between the end plates at different overlap ratios namely 0.0, 0.1 and 0.16 is compared. Helical Savonius rotor without shaft is also compared with the performance of the conventional Savonius rotor. The results indicate that all the helical Savonius rotors have Positive Coefficient of static torque at all the rotor angles. The helical rotors with shaft have lower Coefficient of power than the helical rotors without shaft. Helical rotor without shaft at an overlap ratio of 0.0 and an aspect ratio of 0.88 is found to have almost the same Coefficient of power when compared with the conventional Savonius rotor. Correlation for Coefficient of torque and power is developed for helical Savonius rotor for a range of Reynolds numbers studied.
X. L. Gao - One of the best experts on this subject based on the ideXlab platform.
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Three-dimensional metamaterials with a negative Poisson's ratio and a non-Positive Coefficient of thermal expansion
International Journal of Mechanical Sciences, 2018Co-Authors: L Ai, X. L. GaoAbstract:Four types of three-dimensional (3-D) metallic metamaterials with tailorable thermo-mechanical properties are designed. For the first three types, the structure-property relations are studied by adjusting design parameters including two length parameters, one angle parameter and two material combinations. For the fourth type, one additional angle parameter is involved. It is shown that each of the four types of metamaterials designed exhibits the cubic symmetry and thus needs three independent elastic constants to characterize its elastic behavior and one Coefficient of thermal expansion to describe its isotropic thermal expansion. The effects of the design parameters on the effective Poisson's ratio (PR), Coefficient of thermal expansion (CTE), Young's modulus, shear modulus and the relative density are systematically investigated for each of the four types of designed metamaterials by using unit cell-based finite element simulations that incorporate periodic boundary conditions. It is found that 3-D metallic metamaterials with Positive, near-zero or negative PR and CTE can be obtained by tailoring the bi-material lattice structures and material combinations. Also, it is revealed that metamaterial # 1 can achieve both a negative PR and a non-Positive CTE while maintaining a high stiffness and a low relative density (and thus a lightweight). The good tunability of thermo-mechanical properties of the four types of metamaterials provides an avenue of enabling the expansion of Ashby's material chart to produce more material options for engineering applications.