The Experts below are selected from a list of 204 Experts worldwide ranked by ideXlab platform
Masahiro Goto - One of the best experts on this subject based on the ideXlab platform.
-
Frictional Property depended on crystal preferred orientation analyzed by a combinatorial technique
Tribology Letters, 2014Co-Authors: Masahiro Goto, Akira Kasahara, Michiko Sasaki, Masahiro TosaAbstract:An advanced technique for investigating the Frictional Property of materials depended on crystal preferred orientation is newly proposed. The crystal preferred orientation of ZnO coating films on stainless-steel substrates was markedly changed with the magnitude of an applied load, which was observed by X-ray diffraction analysis with micropoint focus X-ray optics. Also the dependence of the friction coefficient on the crystal preferred orientation was measured. Using the new method, it is possible to find the appropriate crystal preferred orientation for coatings with the desired value of the friction coefficient. Therefore, the technique is expected to be an effective method for tribology research.
-
Frictional Property with preferred crystal orientation of platinum oxide and palladium oxide coatings synthesized by combinatorial sputter coating system
Vacuum, 2006Co-Authors: Masahiro Goto, Akira Kasahara, Masahito TosaAbstract:The combinatorial sputter coating system (COSCOS) has been newly developed, that can fabricate various kinds of coatings under precisely controlled lots of conditions such as selection of sputter gas and gas pressure, gas partial pressure, r.f. power, substrate temperature, distance between a substrate and a target, etc. COSCOS can also control the crystal preferred orientation of coatings which strongly affect those Frictional Property. Platinum oxide and palladium oxide coatings were synthesized by COSCOS, then the crystal structure was analyzed with X-ray diffraction spectroscopy and Frictional properties of the coatings were measured by a tribometer at an atmospheric pressure.
-
low Frictional Property of copper oxide thin films optimised using a combinatorial sputter coating system
Applied Surface Science, 2006Co-Authors: Masahiro Goto, Akira Kasahara, Masahiro TosaAbstract:A combinatorial sputter coating system has been developed that can optimize the crystal preferred orientation of coating films. With this system, it is possible to synthesize various kinds of coatings whilst precisely controlling conditions such as the sputter gas, the gas pressure, the gas partial pressure, the r.f. power, the substrate temperature, the distance between the substrate and target, etc. In this way, we successfully synthesized copper oxide coatings with different crystal preferred orientations, and low Frictional Property was obtained by optimizing the crystal preferred orientation.
-
Frictional Property of zinc oxide coating films observed by lateral force microscopy
Japanese Journal of Applied Physics, 2003Co-Authors: Masahiro Goto, Akira Kasahara, Masahiro Tosa, Youko Konishi, Tetsuo Oishi, Kazuhiro YoshiharaAbstract:Zinc oxide coating films were synthesized by a magnetron sputter deposition method on stainless steel substrates. The crystal structure of the films was analyzed with X-ray diffraction spectroscopy. Adhesion and Frictional properties were obtained from force curves and lateral force data using atomic force microscopy under an atmosphere and in a vacuum. It was found that the friction coefficient decreased in spite of a marked increase in adhesion force on the film surface with heat treatment at 473 K in a vacuum. It was considered that the film surface energy changed during the heat treatment and affected the Frictional properties of the films.
-
improvement of Frictional Property of copper boron nitride complex by excimer laser irradiation
Shinku, 2002Co-Authors: Masahiro Goto, Akira Kasahara, Masahiro Tosa, Kazuhiro YoshiharaAbstract:Low Frictional coating films made of copper and boron nitride complex on a stainless steel substrate were successfully synthesized by magnetron co-sputter deposition with excimer laser irradiation. Frictional Property of the films was observed by a vacuum friction measuring apparatus. The film properties were also obtained by a scanning auger electron spectroscopy, a Vikers hardness measuring apparatus and a contact angle measuring appatatus. Surface energy and film hardness were also modified by the laser irradiation. Friction coefficients as low as 0.075 under ultra-high vacuum conditions were achieved after irradiating the films.
Masahiro Tosa - One of the best experts on this subject based on the ideXlab platform.
-
Frictional Property depended on crystal preferred orientation analyzed by a combinatorial technique
Tribology Letters, 2014Co-Authors: Masahiro Goto, Akira Kasahara, Michiko Sasaki, Masahiro TosaAbstract:An advanced technique for investigating the Frictional Property of materials depended on crystal preferred orientation is newly proposed. The crystal preferred orientation of ZnO coating films on stainless-steel substrates was markedly changed with the magnitude of an applied load, which was observed by X-ray diffraction analysis with micropoint focus X-ray optics. Also the dependence of the friction coefficient on the crystal preferred orientation was measured. Using the new method, it is possible to find the appropriate crystal preferred orientation for coatings with the desired value of the friction coefficient. Therefore, the technique is expected to be an effective method for tribology research.
-
low Frictional Property of copper oxide thin films optimised using a combinatorial sputter coating system
Applied Surface Science, 2006Co-Authors: Masahiro Goto, Akira Kasahara, Masahiro TosaAbstract:A combinatorial sputter coating system has been developed that can optimize the crystal preferred orientation of coating films. With this system, it is possible to synthesize various kinds of coatings whilst precisely controlling conditions such as the sputter gas, the gas pressure, the gas partial pressure, the r.f. power, the substrate temperature, the distance between the substrate and target, etc. In this way, we successfully synthesized copper oxide coatings with different crystal preferred orientations, and low Frictional Property was obtained by optimizing the crystal preferred orientation.
-
Frictional Property of zinc oxide coating films observed by lateral force microscopy
Japanese Journal of Applied Physics, 2003Co-Authors: Masahiro Goto, Akira Kasahara, Masahiro Tosa, Youko Konishi, Tetsuo Oishi, Kazuhiro YoshiharaAbstract:Zinc oxide coating films were synthesized by a magnetron sputter deposition method on stainless steel substrates. The crystal structure of the films was analyzed with X-ray diffraction spectroscopy. Adhesion and Frictional properties were obtained from force curves and lateral force data using atomic force microscopy under an atmosphere and in a vacuum. It was found that the friction coefficient decreased in spite of a marked increase in adhesion force on the film surface with heat treatment at 473 K in a vacuum. It was considered that the film surface energy changed during the heat treatment and affected the Frictional properties of the films.
-
improvement of Frictional Property of copper boron nitride complex by excimer laser irradiation
Shinku, 2002Co-Authors: Masahiro Goto, Akira Kasahara, Masahiro Tosa, Kazuhiro YoshiharaAbstract:Low Frictional coating films made of copper and boron nitride complex on a stainless steel substrate were successfully synthesized by magnetron co-sputter deposition with excimer laser irradiation. Frictional Property of the films was observed by a vacuum friction measuring apparatus. The film properties were also obtained by a scanning auger electron spectroscopy, a Vikers hardness measuring apparatus and a contact angle measuring appatatus. Surface energy and film hardness were also modified by the laser irradiation. Friction coefficients as low as 0.075 under ultra-high vacuum conditions were achieved after irradiating the films.
Hiromichi Fujie - One of the best experts on this subject based on the ideXlab platform.
-
Effect of collagen-induced residual stress on the Frictional Property of articular cartilage
Biosurface and Biotribology, 2018Co-Authors: Hiromichi Fujie, Sou Morishita, Seido YarimitsuAbstract:Previous findings, such as split-line of the articular cartilage surface and curving of sliced cartilage specimen, would suggest that residual stress is contained in articular cartilage. This study was performed to determine the effect of collagen fibre-induced residual stress on the biphasic lubrication Property of articular cartilage. A fibre-reinforced poroelastic model of articular cartilage was developed in Abaqus. In the model, residual stress was contained in the collagen fibre in the surface layer by applying 1-5% of tensile strain. Reciprocating friction analysis was performed between the model and a sphere at a friction speed of 1.0-10.0 mm/s. Results revealed that the coefficients of start-up and dynamic friction at second friction cycle were lower in residual stress model than in no-residual stress model, with the largest decreases observed at a friction speed of 1 mm/s. It was observed that rehydration was promoted in the bearing area in residual stress model. These results suggest that collagen-induced residual stress plays an important role in enhancing the biphasic lubrication Property of articular cartilage.
-
effects of low tangential permeability in the superficial layer on the Frictional Property of articular cartilage
Biosurface and Biotribology, 2015Co-Authors: Hiromichi Fujie, Kyuichiro ImadeAbstract:Abstract The biphasic characteristics of articular cartilage are known to play important roles in cartilage lubrication. However, it is still difficult to biotribologically explain the extremely low friction coefficient observed in articular cartilage. Previous studies have indicated that the surface layer of articular cartilage includes tangentailly-aligned dense collagen fibers while permeability of articular cartilage in tangential direction is dramatically reduced in response to compressive strain. Therefore, we hypothesized that the anisotropic structure and Property in articular cartilage surface improve the lubrication and Frictional properties. A fiber–reinforced poroelastic biphasic model was developed in Abaqus to determine the effect of low tangential permeability on the Frictional Property of articular cartilage. In the model, the tangential permeability in the superficial layer of 100 μm in thickness was reduced to 1/10 as compared with normal permeability. Results revealed that the permeability-reduced superficial layer plays an important role in decreasing friction coefficient in articular cartilage and the role is more significant in slower friction including the start-up friction. Results also revealed that there is a positive effect of the thickness of the low permeability layer on the start-up friction Property, while the effect was almost negligible on the dynamic friction Property.
-
effect of anisotropic permeability of the superficial layer on the Frictional Property in articular cartilage
Volume 1B: Extremity; Fluid Mechanics; Gait; Growth Remodeling and Repair; Heart Valves; Injury Biomechanics; Mechanotransduction and Sub-Cellular Bio, 2013Co-Authors: Kyuichiro Imade, Hiromichi FujieAbstract:Articular cartilage has a significant lubrication Property that has been explained in previous studies by many theories including mixed lubrication, hydrodynamic lubrication, surface gel hydration lubrication, biphasic theory, and so on. However the mechanism of continuously low friction in articular cartilage still remains unclear. Reynaud and Quinn indicated that the hydraulic permeability was significantly anisotropic under compressive strain; the tangential permeability becomes lower than the normal permeability under compression [1]. Meanwhile scanning electron microscopic observation indicated that the superficial layer of articular surface was consisted of close-packed collagen fibers aligning parallel with articular surface and tangling each other in normal cartilage (Fig. 1). It is, therefore, suggested that the permeability is extremely low in the tangential direction when subjected to compressive strain. We have a hypothesis that the unique structure and properties in the articular cartilage superficial layer may improve the lubrication properties [2]. Therefore, we performed an analytical study using a fiber-reinforced poroelastic biphasic model to determine the effect of lateral permeability reduction in the superficial layer on the Frictional Property of articular cartilage.Copyright © 2013 by ASME
Seunghak Baek - One of the best experts on this subject based on the ideXlab platform.
-
Frictional Property comparisons of conventional and self ligating lingual brackets according to tooth displacement during initial leveling and alignment
대한치과교정학회지, 2016Co-Authors: Seunghak BaekAbstract:Objective: We evaluated the effects of tooth displacement on Frictional force when conventional ligating lingual brackets (CL-LBs), CL-LBs with a narrow bracket width, and self-ligating lingual brackets (SL-LBs) were used with initial leveling and alignment wires. Methods: CL-LBs (7th Generation), CLLBs with a narrow bracket width (STb), and SL-LBs (In-Ovation L) were tested under three tooth displacement conditions: no displacement (control); a 2-mm palatal displacement (PD) of the maxillary right lateral incisor (MXLI); and a 2-mm gingival displacement (GD) of the maxillary right canine (MXC) (nine groups, n = 7 per group). A stereolithographic typodont system and artificial saliva were used. Static and kinetic Frictional forces (SFF and KFF, respectively) were measured while drawing a 0.013-inch copper-nickel-titanium archwire through brackets at 0.5 mm/min for 5 minutes at 36.5℃. Results: The In-Ovation L exhibited lower SFF under control conditions and lower KFF under all displacement conditions than the 7th Generation and STb (all p < 0.001). No significant difference in SFF existed between the In-Ovation L and STb for a 2-mm GD of the MXC and 2-mm PD of the MXLI. A 2-mm GD of the MXC produced higher SFF and KFF than a 2-mm PD of the MXLI in all brackets (all p < 0.001). Conclusions: CLLBs with narrow bracket widths exhibited higher KFF than SL-LBs under tooth displacement conditions. CL-LBs and ligation methods should be developed to produce SFF and KFF as low as those in SL-LBs during the initial and leveling stage.
-
Frictional Property comparisons of conventional and self ligating lingual brackets according to tooth displacement during initial leveling and alignment an in vitro mechanical study
Korean Journal of Orthodontics, 2016Co-Authors: Seunghak BaekAbstract:Objective: We evaluated the effects of tooth displacement on Frictional force when conventional ligating lingual brackets (CL-LBs), CL-LBs with a narrow bracket width, and self-ligating lingual brackets (SL-LBs) were used with initial leveling and alignment wires. Methods: CL-LBs (7th Generation), CLLBs with a narrow bracket width (STb), and SL-LBs (In-Ovation L) were tested under three tooth displacement conditions: no displacement (control); a 2-mm palatal displacement (PD) of the maxillary right lateral incisor (MXLI); and a 2-mm gingival displacement (GD) of the maxillary right canine (MXC) (nine groups, n = 7 per group). A stereolithographic typodont system and artificial saliva were used. Static and kinetic Frictional forces (SFF and KFF, respectively) were measured while drawing a 0.013-inch copper-nickel-titanium archwire through brackets at 0.5 mm/min for 5 minutes at 36.5 o C. Results: The In-Ovation L exhibited lower SFF under control conditions and lower KFF under all displacement conditions than the 7th Generation and STb (all p < 0.001). No significant difference in SFF existed between the In-Ovation L and STb for a 2-mm GD of the MXC and 2-mm PD of the MXLI. A 2-mm GD of the MXC produced higher SFF and KFF than a 2-mm PD of the MXLI in all brackets (all p < 0.001). Conclusions: CLLBs with narrow bracket widths exhibited higher KFF than SL-LBs under tooth displacement conditions. CL-LBs and ligation methods should be developed to produce SFF and KFF as low as those in SL-LBs during the initial and leveling stage. [Korean J Orthod 2016;46(2):87-95]
Akira Kasahara - One of the best experts on this subject based on the ideXlab platform.
-
Frictional Property depended on crystal preferred orientation analyzed by a combinatorial technique
Tribology Letters, 2014Co-Authors: Masahiro Goto, Akira Kasahara, Michiko Sasaki, Masahiro TosaAbstract:An advanced technique for investigating the Frictional Property of materials depended on crystal preferred orientation is newly proposed. The crystal preferred orientation of ZnO coating films on stainless-steel substrates was markedly changed with the magnitude of an applied load, which was observed by X-ray diffraction analysis with micropoint focus X-ray optics. Also the dependence of the friction coefficient on the crystal preferred orientation was measured. Using the new method, it is possible to find the appropriate crystal preferred orientation for coatings with the desired value of the friction coefficient. Therefore, the technique is expected to be an effective method for tribology research.
-
Frictional Property with preferred crystal orientation of platinum oxide and palladium oxide coatings synthesized by combinatorial sputter coating system
Vacuum, 2006Co-Authors: Masahiro Goto, Akira Kasahara, Masahito TosaAbstract:The combinatorial sputter coating system (COSCOS) has been newly developed, that can fabricate various kinds of coatings under precisely controlled lots of conditions such as selection of sputter gas and gas pressure, gas partial pressure, r.f. power, substrate temperature, distance between a substrate and a target, etc. COSCOS can also control the crystal preferred orientation of coatings which strongly affect those Frictional Property. Platinum oxide and palladium oxide coatings were synthesized by COSCOS, then the crystal structure was analyzed with X-ray diffraction spectroscopy and Frictional properties of the coatings were measured by a tribometer at an atmospheric pressure.
-
low Frictional Property of copper oxide thin films optimised using a combinatorial sputter coating system
Applied Surface Science, 2006Co-Authors: Masahiro Goto, Akira Kasahara, Masahiro TosaAbstract:A combinatorial sputter coating system has been developed that can optimize the crystal preferred orientation of coating films. With this system, it is possible to synthesize various kinds of coatings whilst precisely controlling conditions such as the sputter gas, the gas pressure, the gas partial pressure, the r.f. power, the substrate temperature, the distance between the substrate and target, etc. In this way, we successfully synthesized copper oxide coatings with different crystal preferred orientations, and low Frictional Property was obtained by optimizing the crystal preferred orientation.
-
Frictional Property of zinc oxide coating films observed by lateral force microscopy
Japanese Journal of Applied Physics, 2003Co-Authors: Masahiro Goto, Akira Kasahara, Masahiro Tosa, Youko Konishi, Tetsuo Oishi, Kazuhiro YoshiharaAbstract:Zinc oxide coating films were synthesized by a magnetron sputter deposition method on stainless steel substrates. The crystal structure of the films was analyzed with X-ray diffraction spectroscopy. Adhesion and Frictional properties were obtained from force curves and lateral force data using atomic force microscopy under an atmosphere and in a vacuum. It was found that the friction coefficient decreased in spite of a marked increase in adhesion force on the film surface with heat treatment at 473 K in a vacuum. It was considered that the film surface energy changed during the heat treatment and affected the Frictional properties of the films.
-
improvement of Frictional Property of copper boron nitride complex by excimer laser irradiation
Shinku, 2002Co-Authors: Masahiro Goto, Akira Kasahara, Masahiro Tosa, Kazuhiro YoshiharaAbstract:Low Frictional coating films made of copper and boron nitride complex on a stainless steel substrate were successfully synthesized by magnetron co-sputter deposition with excimer laser irradiation. Frictional Property of the films was observed by a vacuum friction measuring apparatus. The film properties were also obtained by a scanning auger electron spectroscopy, a Vikers hardness measuring apparatus and a contact angle measuring appatatus. Surface energy and film hardness were also modified by the laser irradiation. Friction coefficients as low as 0.075 under ultra-high vacuum conditions were achieved after irradiating the films.
