The Experts below are selected from a list of 279 Experts worldwide ranked by ideXlab platform
Yoshitaka Nakanishi - One of the best experts on this subject based on the ideXlab platform.
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Biomimetic Shaft Seal for Ocean Current or Tidal Power Generation
2018 7th International Conference on Renewable Energy Research and Applications (ICRERA), 2018Co-Authors: Yoshitaka Nakanishi, Yuta Nakashima, Yuki Yoshioka, Takuro HondaAbstract:Two types of biomimetic shaft Seal were designed in order to adopt this item for ocean current and tidal power generation systems, where perfect separation between water and air with a rotating shaft was required. A biomimetic Seal ring was proposed. This was made of a PVF (polyvinyl formal). It imitated the structure and lubrication mechanism of a natural articular cartilage. The PVF ring was attached to the rotating shaft was pressed to the ceramic ring fixed with a mechanical body. It was confirmed that the design concept of the biomimetic shaft Seal was successful in verification tests where the rotation speed of the shaft changed from 5,000 to -5,000 revolutions per minute (\min^{-1}) under pressurized water of 0.5 MPa. However, there was room for improvement in the biomimetic shaft Seal: 1) Plastic deformation of the PVF ring should be avoided in order to inhibit the clearance flow in the Dynamic Seal face. 2) The surface profile of the ceramics surface as a counterface of the PVF ring should be discussed because the profile can promote both hydrated lubrication at the Dynamic Seal face and the nonnegligible wear of the PVF ring. 3) Heat generation at the Dynamic Seal face should be avoided because the heat changes the material property of the PVF ring.
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Low-friction shaft Seal composed of bio-inspired materials covering low-speed range under water environment:
Proceedings of the Institution of Mechanical Engineers Part J: Journal of Engineering Tribology, 2017Co-Authors: Takuro Honda, Keiji Kasamura, Yuta Nakashima, Hidehiko Higaki, Yoshitaka NakanishiAbstract:Shaft Seals with a Seal lip are used in various applications to separate gases and fluids, but their Sealing function and durability are affected by the extent of lubrication at the Dynamic Seal faces between a rotating shaft and the Seal lip. A new Sealing system consisting of two hydrated Seal rings and non-Newtonian lubricants was designed by a biomimetic approach to minimise frictional loss and provide high waterproof function when separating air and water. This system demonstrates significant superiority in low-speed rotation, conditions under which the lubrication mechanism of an oil Seal or mechanical Seal does not generally work well. Fibre reinforcement of the Seal ring material was performed to prevent the deformation of the soft Seal rings because of the frictional force in the tangential direction of the shaft and water pressure. This reinforcement enabled the new Sealing system to obtain both high waterproof performance and low frictional characteristics in the speed range of 20–100 r/min.
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Shaft Seal for separation of water and air with low frictional torque
Tribology International, 2016Co-Authors: Yoshitaka Nakanishi, Takuro Honda, Yuta Nakashima, Hidehiko HigakiAbstract:A new type of shaft Seal was specifically designed to separate water and air with a low frictional torque. The proposed water-Sealing system, which was implemented as a shaft Seal, has two hydrated Seal lips fabricated from polyvinyl formal. An aqueous solution of polyethylene glycol, which is a non-Newtonian fluid, was injected between the Seal lips to support the lubrication and Sealing action at the Dynamic Seal faces. These configurations are based on a biomimetic approach, namely, the mechanism in a natural synovial joint. The water-Sealing system exhibited a lower frictional torque than that of oil and mechanical Seals, and the friction was not influenced by the applied water pressure. The prevention of water leakage from the water phase to the air phase was also confirmed for water pressure up to 0.8 MPa. The proposed water-Sealing system may contribute to the improvement of the recovery efficiency of natural energy systems utilizing water flows, tidal currents, and ocean currents, in which the rotating speed of a shaft is low under high water pressure.
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Biomimetic Sealing system with hydrated materials for ocean current or tidal power generation
Renewable Energy Research and Application (ICRERA), 2014 International Conference on, 2014Co-Authors: Yoshitaka Nakanishi, Yuichi Oka, Takuro Honda, Keiji Kasamura, Jason Sanderson, Yuta Nakashima, Hidehiko HigakiAbstract:An all-new Sealing system for a rotating shaft, which specializes in excellent separation between water and air, has been developed for installation in an ocean current or tidal power generator. Two Seal lips made of a polyvinyl formal (PVF) were attached to a rotating shaft, and an aqueous solution of 3.0 wt% polyethylene glycol (PEG), a non-Newtonian fluid with a molecular weight of 2.0 million, was supplied between two lips for lubrication. Expected lubrication modes between the Dynamic Seal surfaces were hydration lubrication, soft-elastohydroDynamic lubrication, and weeping lubrication, similar to that observed in a natural synovial joint. Using PVF with a small porous diameter of 8 μm and continuously porous structure promoted hydration lubrication between Seal surfaces at the molecular level, and low leakage of water, less than 0.05 ml/h, throughout the experiment. Mean frictional torque was lower than that found in the mechanical and oil Seals that are generally used for industrial components. Frictional torque had been stable; the friction was independent of the shaft rotational speed, and the stick-slip friction that might lead to leakage of water was moderated in comparison with the conventional Sealing systems.
Hidehiko Higaki - One of the best experts on this subject based on the ideXlab platform.
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Low-friction shaft Seal composed of bio-inspired materials covering low-speed range under water environment:
Proceedings of the Institution of Mechanical Engineers Part J: Journal of Engineering Tribology, 2017Co-Authors: Takuro Honda, Keiji Kasamura, Yuta Nakashima, Hidehiko Higaki, Yoshitaka NakanishiAbstract:Shaft Seals with a Seal lip are used in various applications to separate gases and fluids, but their Sealing function and durability are affected by the extent of lubrication at the Dynamic Seal faces between a rotating shaft and the Seal lip. A new Sealing system consisting of two hydrated Seal rings and non-Newtonian lubricants was designed by a biomimetic approach to minimise frictional loss and provide high waterproof function when separating air and water. This system demonstrates significant superiority in low-speed rotation, conditions under which the lubrication mechanism of an oil Seal or mechanical Seal does not generally work well. Fibre reinforcement of the Seal ring material was performed to prevent the deformation of the soft Seal rings because of the frictional force in the tangential direction of the shaft and water pressure. This reinforcement enabled the new Sealing system to obtain both high waterproof performance and low frictional characteristics in the speed range of 20–100 r/min.
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Shaft Seal for separation of water and air with low frictional torque
Tribology International, 2016Co-Authors: Yoshitaka Nakanishi, Takuro Honda, Yuta Nakashima, Hidehiko HigakiAbstract:A new type of shaft Seal was specifically designed to separate water and air with a low frictional torque. The proposed water-Sealing system, which was implemented as a shaft Seal, has two hydrated Seal lips fabricated from polyvinyl formal. An aqueous solution of polyethylene glycol, which is a non-Newtonian fluid, was injected between the Seal lips to support the lubrication and Sealing action at the Dynamic Seal faces. These configurations are based on a biomimetic approach, namely, the mechanism in a natural synovial joint. The water-Sealing system exhibited a lower frictional torque than that of oil and mechanical Seals, and the friction was not influenced by the applied water pressure. The prevention of water leakage from the water phase to the air phase was also confirmed for water pressure up to 0.8 MPa. The proposed water-Sealing system may contribute to the improvement of the recovery efficiency of natural energy systems utilizing water flows, tidal currents, and ocean currents, in which the rotating speed of a shaft is low under high water pressure.
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Biomimetic Sealing system with hydrated materials for ocean current or tidal power generation
Renewable Energy Research and Application (ICRERA), 2014 International Conference on, 2014Co-Authors: Yoshitaka Nakanishi, Yuichi Oka, Takuro Honda, Keiji Kasamura, Jason Sanderson, Yuta Nakashima, Hidehiko HigakiAbstract:An all-new Sealing system for a rotating shaft, which specializes in excellent separation between water and air, has been developed for installation in an ocean current or tidal power generator. Two Seal lips made of a polyvinyl formal (PVF) were attached to a rotating shaft, and an aqueous solution of 3.0 wt% polyethylene glycol (PEG), a non-Newtonian fluid with a molecular weight of 2.0 million, was supplied between two lips for lubrication. Expected lubrication modes between the Dynamic Seal surfaces were hydration lubrication, soft-elastohydroDynamic lubrication, and weeping lubrication, similar to that observed in a natural synovial joint. Using PVF with a small porous diameter of 8 μm and continuously porous structure promoted hydration lubrication between Seal surfaces at the molecular level, and low leakage of water, less than 0.05 ml/h, throughout the experiment. Mean frictional torque was lower than that found in the mechanical and oil Seals that are generally used for industrial components. Frictional torque had been stable; the friction was independent of the shaft rotational speed, and the stick-slip friction that might lead to leakage of water was moderated in comparison with the conventional Sealing systems.
George M. Whitesides - One of the best experts on this subject based on the ideXlab platform.
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paper machine for molecular diagnostics
Analytical Chemistry, 2015Co-Authors: John T. Connelly, Jannick P Rolland, George M. WhitesidesAbstract:Clinical tests based on primer-initiated amplification of specific nucleic acid sequences achieve high levels of sensitivity and specificity. Despite these desirable characteristics, these tests have not reached their full potential because their complexity and expense limit their usefulness to centralized laboratories. This paper describes a device that integrates sample preparation and loop-mediated isothermal amplification (LAMP) with end point detection using a hand-held UV source and camera phone. The prototype device integrates paper microfluidics (to enable fluid handling) and a multilayer structure, or a “paper machine”, that allows a central patterned paper strip to slide in and out of fluidic path and thus allows introduction of sample, wash buffers, amplification master mix, and detection reagents with minimal pipetting, in a hand-held, disposable device intended for point-of-care use in resource-limited environments. This device creates a Dynamic Seal that prevents evaporation during incubatio...
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"Paper Machine" for Molecular Diagnostics
Analytical Chemistry, 2015Co-Authors: John T. Connelly, Jannick P Rolland, George M. WhitesidesAbstract:© 2015 American Chemical Society. Clinical tests based on primer-initiated amplification of specific nucleic acid sequences achieve high levels of sensitivity and specificity. Despite these desirable characteristics, these tests have not reached their full potential because their complexity and expense limit their usefulness to centralized laboratories. This paper describes a device that integrates sample preparation and loop-mediated isothermal amplification (LAMP) with end point detection using a hand-held UV source and camera phone. The prototype device integrates paper microfluidics (to enable fluid handling) and a multilayer structure, or a "paper machine", that allows a central patterned paper strip to slide in and out of fluidic path and thus allows introduction of sample, wash buffers, amplification master mix, and detection reagents with minimal pipetting, in a hand-held, disposable device intended for point-of-care use in resource-limited environments. This device creates a Dynamic Seal that prevents evaporation during incubation at 65°C for 1 h. This interval is sufficient to allow a LAMP reaction for the Escherichia coli malB gene to proceed with an analytical sensitivity of 1 double-stranded DNA target copy. Starting with human plasma spiked with whole, live E. coli cells, this paper demonstrates full integration of sample preparation with LAMP amplification and end point detection with a limit of detection of 5 cells. Further, it shows that the method used to prepare sample enables concentration of DNA from sample volumes commonly available from fingerstick blood draw.
Takuro Honda - One of the best experts on this subject based on the ideXlab platform.
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Biomimetic Shaft Seal for Ocean Current or Tidal Power Generation
2018 7th International Conference on Renewable Energy Research and Applications (ICRERA), 2018Co-Authors: Yoshitaka Nakanishi, Yuta Nakashima, Yuki Yoshioka, Takuro HondaAbstract:Two types of biomimetic shaft Seal were designed in order to adopt this item for ocean current and tidal power generation systems, where perfect separation between water and air with a rotating shaft was required. A biomimetic Seal ring was proposed. This was made of a PVF (polyvinyl formal). It imitated the structure and lubrication mechanism of a natural articular cartilage. The PVF ring was attached to the rotating shaft was pressed to the ceramic ring fixed with a mechanical body. It was confirmed that the design concept of the biomimetic shaft Seal was successful in verification tests where the rotation speed of the shaft changed from 5,000 to -5,000 revolutions per minute (\min^{-1}) under pressurized water of 0.5 MPa. However, there was room for improvement in the biomimetic shaft Seal: 1) Plastic deformation of the PVF ring should be avoided in order to inhibit the clearance flow in the Dynamic Seal face. 2) The surface profile of the ceramics surface as a counterface of the PVF ring should be discussed because the profile can promote both hydrated lubrication at the Dynamic Seal face and the nonnegligible wear of the PVF ring. 3) Heat generation at the Dynamic Seal face should be avoided because the heat changes the material property of the PVF ring.
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Low-friction shaft Seal composed of bio-inspired materials covering low-speed range under water environment:
Proceedings of the Institution of Mechanical Engineers Part J: Journal of Engineering Tribology, 2017Co-Authors: Takuro Honda, Keiji Kasamura, Yuta Nakashima, Hidehiko Higaki, Yoshitaka NakanishiAbstract:Shaft Seals with a Seal lip are used in various applications to separate gases and fluids, but their Sealing function and durability are affected by the extent of lubrication at the Dynamic Seal faces between a rotating shaft and the Seal lip. A new Sealing system consisting of two hydrated Seal rings and non-Newtonian lubricants was designed by a biomimetic approach to minimise frictional loss and provide high waterproof function when separating air and water. This system demonstrates significant superiority in low-speed rotation, conditions under which the lubrication mechanism of an oil Seal or mechanical Seal does not generally work well. Fibre reinforcement of the Seal ring material was performed to prevent the deformation of the soft Seal rings because of the frictional force in the tangential direction of the shaft and water pressure. This reinforcement enabled the new Sealing system to obtain both high waterproof performance and low frictional characteristics in the speed range of 20–100 r/min.
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Shaft Seal for separation of water and air with low frictional torque
Tribology International, 2016Co-Authors: Yoshitaka Nakanishi, Takuro Honda, Yuta Nakashima, Hidehiko HigakiAbstract:A new type of shaft Seal was specifically designed to separate water and air with a low frictional torque. The proposed water-Sealing system, which was implemented as a shaft Seal, has two hydrated Seal lips fabricated from polyvinyl formal. An aqueous solution of polyethylene glycol, which is a non-Newtonian fluid, was injected between the Seal lips to support the lubrication and Sealing action at the Dynamic Seal faces. These configurations are based on a biomimetic approach, namely, the mechanism in a natural synovial joint. The water-Sealing system exhibited a lower frictional torque than that of oil and mechanical Seals, and the friction was not influenced by the applied water pressure. The prevention of water leakage from the water phase to the air phase was also confirmed for water pressure up to 0.8 MPa. The proposed water-Sealing system may contribute to the improvement of the recovery efficiency of natural energy systems utilizing water flows, tidal currents, and ocean currents, in which the rotating speed of a shaft is low under high water pressure.
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Biomimetic Sealing system with hydrated materials for ocean current or tidal power generation
Renewable Energy Research and Application (ICRERA), 2014 International Conference on, 2014Co-Authors: Yoshitaka Nakanishi, Yuichi Oka, Takuro Honda, Keiji Kasamura, Jason Sanderson, Yuta Nakashima, Hidehiko HigakiAbstract:An all-new Sealing system for a rotating shaft, which specializes in excellent separation between water and air, has been developed for installation in an ocean current or tidal power generator. Two Seal lips made of a polyvinyl formal (PVF) were attached to a rotating shaft, and an aqueous solution of 3.0 wt% polyethylene glycol (PEG), a non-Newtonian fluid with a molecular weight of 2.0 million, was supplied between two lips for lubrication. Expected lubrication modes between the Dynamic Seal surfaces were hydration lubrication, soft-elastohydroDynamic lubrication, and weeping lubrication, similar to that observed in a natural synovial joint. Using PVF with a small porous diameter of 8 μm and continuously porous structure promoted hydration lubrication between Seal surfaces at the molecular level, and low leakage of water, less than 0.05 ml/h, throughout the experiment. Mean frictional torque was lower than that found in the mechanical and oil Seals that are generally used for industrial components. Frictional torque had been stable; the friction was independent of the shaft rotational speed, and the stick-slip friction that might lead to leakage of water was moderated in comparison with the conventional Sealing systems.
Dezhang Wang - One of the best experts on this subject based on the ideXlab platform.
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ICDMA - Calculation and Analysis of Traction Infinitely Variable Transmission
2011 Second International Conference on Digital Manufacturing & Automation, 2011Co-Authors: Lei Tong, Su Wang, Dezhang WangAbstract:Traction oil film thickness calculation is done on a kind of continuous velocity transmission which is named traction infinitely variable transmission (TIVT). It is proved that transmission type of TIVT is traction drive rather than friction drive through design on roughness, material of parts and traction oil. Dynamic Seal and roller deformation are analyzed through building models and making calculations of it, which proves great defect exists in structure of TIVT.
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Calculation and Analysis of Traction Infinitely Variable Transmission
2011 Second International Conference on Digital Manufacturing & Automation, 2011Co-Authors: Lei Tong, Su Wang, Dezhang WangAbstract:Traction oil film thickness calculation is done on a kind of continuous velocity transmission which is named traction infinitely variable transmission (TIVT). It is proved that transmission type of TIVT is traction drive rather than friction drive through design on roughness, material of parts and traction oil. Dynamic Seal and roller deformation are analyzed through building models and making calculations of it, which proves great defect exists in structure of TIVT.
