The Experts below are selected from a list of 288 Experts worldwide ranked by ideXlab platform
Viral S. Mehta - One of the best experts on this subject based on the ideXlab platform.
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a transient hydrodynamic lubrication model for piston cylinder interface of variable length
Tribology International, 2018Co-Authors: Jane Q Wang, Viral S. MehtaAbstract:Abstract Hydraulic machinery transfers energy between a fluid and a mechanical system. The swash plate pump is one of the most widely used pumps because of its simple and compact structure. The piston/cylinder system is the core of the swash plate pump, and its lubrication characteristics greatly affect the overall pumping performance. This study is aimed at the development of a transient hydrodynamic lubrication model for the pumps with varying length of the piston-cylinder interface and the investigation of the influences of cylinder length, clearance, as well as other design parameters, on the pump piston forces and friction. The changing domain and moving boundaries of the varying piston-cylinder interface impose a challenge to the modeling, and a novel equal-Displacement-Step method is developed to tackle this issue. The pressure, film thickness, and friction performances of varying and constant interface-length systems are studied, and the former is further analyzed in detail. The results indicate that increasing the cylinder length reduces the misalignment angle and raises the minimum film thickness, but it increases the maximum friction force at and slightly off the location for the maximum velocity because friction is related to velocity and the interfacial area. A longer piston is preferred, and the optimal length for stability should be L 0 / L min = 1.71 for the system analyzed in this study.
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A transient hydrodynamic lubrication model for piston/cylinder interface of variable length
Tribology International, 2018Co-Authors: Q. Jane Wang, Viral S. MehtaAbstract:Abstract Hydraulic machinery transfers energy between a fluid and a mechanical system. The swash plate pump is one of the most widely used pumps because of its simple and compact structure. The piston/cylinder system is the core of the swash plate pump, and its lubrication characteristics greatly affect the overall pumping performance. This study is aimed at the development of a transient hydrodynamic lubrication model for the pumps with varying length of the piston-cylinder interface and the investigation of the influences of cylinder length, clearance, as well as other design parameters, on the pump piston forces and friction. The changing domain and moving boundaries of the varying piston-cylinder interface impose a challenge to the modeling, and a novel equal-Displacement-Step method is developed to tackle this issue. The pressure, film thickness, and friction performances of varying and constant interface-length systems are studied, and the former is further analyzed in detail. The results indicate that increasing the cylinder length reduces the misalignment angle and raises the minimum film thickness, but it increases the maximum friction force at and slightly off the location for the maximum velocity because friction is related to velocity and the interfacial area. A longer piston is preferred, and the optimal length for stability should be L 0 / L min = 1.71 for the system analyzed in this study.
Q. Jane Wang - One of the best experts on this subject based on the ideXlab platform.
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A transient hydrodynamic lubrication model for piston/cylinder interface of variable length
Tribology International, 2018Co-Authors: Q. Jane Wang, Viral S. MehtaAbstract:Abstract Hydraulic machinery transfers energy between a fluid and a mechanical system. The swash plate pump is one of the most widely used pumps because of its simple and compact structure. The piston/cylinder system is the core of the swash plate pump, and its lubrication characteristics greatly affect the overall pumping performance. This study is aimed at the development of a transient hydrodynamic lubrication model for the pumps with varying length of the piston-cylinder interface and the investigation of the influences of cylinder length, clearance, as well as other design parameters, on the pump piston forces and friction. The changing domain and moving boundaries of the varying piston-cylinder interface impose a challenge to the modeling, and a novel equal-Displacement-Step method is developed to tackle this issue. The pressure, film thickness, and friction performances of varying and constant interface-length systems are studied, and the former is further analyzed in detail. The results indicate that increasing the cylinder length reduces the misalignment angle and raises the minimum film thickness, but it increases the maximum friction force at and slightly off the location for the maximum velocity because friction is related to velocity and the interfacial area. A longer piston is preferred, and the optimal length for stability should be L 0 / L min = 1.71 for the system analyzed in this study.
Jane Q Wang - One of the best experts on this subject based on the ideXlab platform.
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a transient hydrodynamic lubrication model for piston cylinder interface of variable length
Tribology International, 2018Co-Authors: Jane Q Wang, Viral S. MehtaAbstract:Abstract Hydraulic machinery transfers energy between a fluid and a mechanical system. The swash plate pump is one of the most widely used pumps because of its simple and compact structure. The piston/cylinder system is the core of the swash plate pump, and its lubrication characteristics greatly affect the overall pumping performance. This study is aimed at the development of a transient hydrodynamic lubrication model for the pumps with varying length of the piston-cylinder interface and the investigation of the influences of cylinder length, clearance, as well as other design parameters, on the pump piston forces and friction. The changing domain and moving boundaries of the varying piston-cylinder interface impose a challenge to the modeling, and a novel equal-Displacement-Step method is developed to tackle this issue. The pressure, film thickness, and friction performances of varying and constant interface-length systems are studied, and the former is further analyzed in detail. The results indicate that increasing the cylinder length reduces the misalignment angle and raises the minimum film thickness, but it increases the maximum friction force at and slightly off the location for the maximum velocity because friction is related to velocity and the interfacial area. A longer piston is preferred, and the optimal length for stability should be L 0 / L min = 1.71 for the system analyzed in this study.
Thomas P. Burghardt - One of the best experts on this subject based on the ideXlab platform.
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Ventricular Myosin Modifies in Vitro Step-Size When Phosphorylated
Biophysical Journal, 2014Co-Authors: Yihua Wang, Katalin Ajtai, Thomas P. BurghardtAbstract:Cardiac and skeletal muscle myosins have the central role in contraction transducing ATP free energy into the mechanical work of moving actin in transduction/mechanical coupling. Inheritable cardiomyopathies are more frequently linked to myosin mutations than other sarcomeric proteins. Hereditary skeletal myopathies linked to myosin are less common. They lead to muscle weakness or affect myosin isoforms expressed during development leading to arthrogryposis syndromes. Myosin has a motor domain containing ATP and actin binding sites and light chains stabilized lever-arm that undergoes rotation impelling bound actin. The lever-arm converts torque generated in the motor into linear Displacement (Step-size). Relative myosin and actin filament sliding is modeled in vitro with a motility assay quantitating actin filament translation over a myosin coated surface. A novel quantum dot super-resolution in vitro motility assay confirmed a 5 nm Step-size for fast skeletal myosin while β cardiac myosin (βMys) had multiple unitary Steps, most frequently 5 and 8 nm, and a rare 3 nm Displacement. The myosin lever-arm is stabilized by bound essential and regulatory light chains (ELC and RLC). RLC phosphorylation at S15 is linked to modified lever-arm mechanical characteristics contributing to disease and to myosin filament based contraction regulation. We have studied the effect of RLC phosphorylation on the Step-size of porcine βMys. Phosphorylated βMys has ∼85% of the myosin phosphorylated. We find RLC phosphorylation causing the distribution of longest Step increasing from 37% to 71%. This dramatic re-distribution of Step-sizes provides significant gain in average Step-size. The results indicate a mechanism for contraction regulation by Step-size adaptation using post-translational modification of the myosin filament via RLC phosphorylation. Research supported by R01AR049277, R01HL095572 and the Mayo Foundation.
A. A. Sinitsyn - One of the best experts on this subject based on the ideXlab platform.
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Choosing parameters of space-time signal processing in ultrasonic structuroscopy of cast-iron molds subjected to thermal cycling
Russian Journal of Nondestructive Testing, 2016Co-Authors: V. K. Kachanov, V. G. Kartashev, L. V. Voronkova, I. V. Sokolov, R. V. Kontsov, A. A. SinitsynAbstract:It is shown that in order to improve the accuracy of measuring the speed of ultrasonic vibrations in cast-iron products by echo-pulse method, one should use noise-immune space-time echosignal processing methods that improve signal–to–pattern-noise ratio. Signal parameters should also be adapted for characteristics of the test object. Requirements for the choice of probing-signal parameters have been established as well as optimum Displacement Step of a double-crystal transducer. The value of the speed of ultrasound at a time moment that precedes the destruction of cast-iron mold has been determined.
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Selection of optimal Displacement Step of a transducer in ultrasonic control of complexly structured articles
Measurement Techniques, 2012Co-Authors: V. G. Kartashev, L. V. Voronkova, E. V. Shalimova, A. A. SinitsynAbstract:The selection of the optimal Displacement Step of a dual-element mosaic ultrasonic transducer as it scans the surface of a controlled article for the purpose of increasing the signal-to-structural noise ratio in the course of ultrasonic thickness testing of complexly structured articles is considered.