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Journal of Thermal Science 2012年第4期21卷 322-326页

作者： Taiki matsuura Masaya Suzuki makoto Yamamoto Shinichiro Shishido Takeshi Murooka Hiroshi Miyagawa Graduate School of Mechanical Engineering Tokyo University of Science 1-14-6 Kudankita Chiyoda-ku Department of Mechanical Engineering Tokyo University of Science 1-14-6 Kudankita Chiyoda-ku Research and Engineering Division IHI Corporation 229 Tonogaya Mizuho-cho Nishitama-gun

Ice accretion is the phenomenon that super-cooled water droplets impinge and accrete on a body. It is well known that ice accretion on blades and airfoils leads to performance degradation and severe accidents. For this reason, experimental investigations have been carried out using flight tests or icing tunnels. However, it is too expensive, dangerous, and difficult to set actual icing conditions. Hence, computational fluid dynamics is useful to predict ice accretion. A rotor blade is one of jet engine components where ice accretes. Therefore, the authors focus on the ice accretion on a rotor blade in this study. Three-dimensional icing phenomena on the rotor blade of a commercial axial blower are computed here, and ice accretion on the rotor blade is numerically investigated.

关键词： Icing Computational Fluid Dynamics Euler-Lagrangian Coupling Rotor Blade Axial Blower

Rate-, state-, and pressure-dependent friction model based on the elastoplastic theory

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Friction 2020年第4期8卷 768-783页

作者： Shingo OZAKI Takeru matsuura Satoru MAEGAWA Division of System Research Yokohama National UniversityTokiwadai 79-5Hodogaya-kuYokohama 240-8501Japan Department of Electrical and Mechanical Engineering Nagoya Institute of TechnologyGokiso-choShowa-kuNagoya 466-8555Japan

Adhesion is one of essences with respect to rubber friction because the magnitude of the friction force is closely related to the magnitude of adhesion on a real contact area. However, the real contact area during sliding depends on the state and history of the contact surface. Therefore, the friction force occasionally exhibits rate-, state-, and pressure dependency. In this study, to rationally describe friction and simulate boundary value problems, a rate-, state-, and pressure-dependent friction model based on the elastoplastic theory was formulated. First, the evolution law for the friction coefficient was prescribed. Next, a nonlinear sliding surface (frictional criterion) was adopted, and several other evolution laws for internal state variables were prescribed. Subsequently, the typical response characteristics of the proposed friction model were demonstrated, and its validity was verified by comparing the obtained results with those of experiments conducted considering the contact surface between a rough rubber hemisphere and smooth acrylic plate.

关键词： adhesion friction model elastoplastic theory contact surface stick-slip

Coatings on Mg alloys and their mechanical properties: A review

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Journal of Materials Science & Technology 2018年第7期34卷 1119-1126页

作者： Toko Tokunaga Munekazu Ohno Kiyotaka matsuura Faculty of Engineering Hokkaido University

Poor corrosion resistance is a serious drawback of Mg alloys, restricting their practical applications. Coating is one of the effective techniques for improvement in the poor corrosion resistance. In this paper, the coating processes for Mg alloys so far developed are reviewed. Among several processes, the coating processes based on mechanical energy, including metal forming, are attractive because the corrosion resistance and formability of Mg alloys are simultaneously improved.2017 Published by Elsevier Ltd on behalf of The editorial office of Journal of Materials Science ＆ Technology.

关键词： Magnesium alloy Coating Mechanical property Corrosion resistance

Phase Equilibrium for the CaO-SiO_2-FeO-P_2O_5 System at 1673K for Dephosphorization With Multi Phase Flux

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Journal of Iron and Steel Research International 2011年第S2期18卷 84-86页

作者： Hiroyuki matsuura Fumitaka TSUKIHASHI Graduate School of Frontier Sciences The University of Tokyo Kashiwa Chiba 277-8561 Japan

Development of the efficient hot metal dephosphorization processes during steelmaking process is one of the most essential topics for the production of high grade clean steels. Since the formation of solid solution composed of tricalcium phosphate and dicalcium silicate could obtain a considerable mass transfer of phosphorus from liquid slag into solid phase during hot metal dephosphorization, itcould obviously sustain a high phosphatecapacityof theliquid slag without huge consumption of lime or addition of fluxes, such as fluorite. The above outlines are the main idea of multi phase flux dephosphorization. For the last few decades, many studies have been done towards the scientific principles and the commercial utilization of this technique. However, the reaction mechanism by using multi phase fluxes remains unclear even by now due tolack of evidence. Based on those previous works, providing a reliable and available phase diagram for the fundamental understanding of the reaction mechanism of multi phase flux dephosphorization has become the main purpose of present research. As well known, the CaO-SiO2-FeO-P2O5 slag is the main component of current steelmaking process. Hence the CaO-SiO2-FeO-P2O5 system at equilibrium has been studied at 1673K with low oxygen partial pressure. The solid phase coexisting with liquid flux is approved to be the solid solution composed of CaO, SiO2 and P2O5. Phosphorus distributes mainly in solid solution rather than liquid phase.

关键词： steelmaking dephosphorization multi phase flux thermodynamics phase diagram

Structure of vitreous body and its relationship with liquefaction

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Journal of Biomedical Science and Engineering 2013年第7期6卷 739-745页

作者： makoto Kodama Toyoaki matsuura Yoshiaki Hara Department of Ophthalmology Nara Medical University Nara Japan Graduate School of Life Science and Systems Engineering Kyushu Institute of Technology Fukuoka Japan

The aim of the study is to clarify the vitreous body structure and liquefaction phenomena. It was found that when melting a frozen rabbit vitreous body, the gel-sol transition phenomenon occurs and the gel structure is broken. This is almost like the liquefaction of the vitreous body in vivo. We try to clarify the liquefaction phenomenon by using this animal model. The native vitreous body has three dimensional meshwork structures. After liquefaction, it is changed into two parts, namely fiber aggregates and soluble amorphous aggregates. The surface of native vitreous body meshwork is mucopolysacharide, but that of fiber aggregates after liquefaction is changed into connective tissue, which means the conformational change of vitreous body in liquefaction. The soluble proteins after liquefaction were analyzed and identified as crystallin family. It is suggested that the liquefaction is induced by detachment of non-collagenous protein beads containing crystallins, resulting in the collapse of the three dimensional structure to release watery liquid trapped within. And the new gel-sol transition model of vitreous bod is proposed.

关键词： Vitreous Body Liquefaction Crystallin

Preparation and incubation conditions affect the DNA integrity of ejaculated human spermatozoa

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Asian Journal of Andrology 2010年第5期12卷 753-759页

作者： Rieko matsuura Takumi Takeuchi Atsumi Yoshida The Reproduction Center Kiba Park Clinic Tokyo 135-0042 Japan

Appropriate semen processing and assessment are critical for successful infertility treatment. We investigated whether laboratory procedures including semen preparation and incubation affect sperm DNA integrity. A total of 153 infertile men were involved. Conventional semen parameters and sperm chromatin structure assay （SCSA） parameters, that is, DNA fragmentation index （%DFI） and high DNA stainability （%HDS）, were assessed on the flesh ejaculated semen samples, which were treated and incubated under different conditions. Negative correlations were identified between the %DFI and sperm concentration, motility, progressive motility and morphology. A lower percentage of DFI was detected in spermatozoa when density gradient centrifugation （DGC） was followed by swimup treatment in comparison with DGC alone （P 〈 0.01）. Although the %DFI increased in a time-dependent manner with incubation both at room temperature （RT） and at 37℃ in air, the %DFI after 24 h at RT was significantly lower than that at 37℃ （P 〈 0.05）. Incubation with 5% CO2 was effective in maintaining sperm motility （P 〈 0.01）; however, it induced further elevation of %DFI （P 〈 0.001）. Thus, sperm DNA damage was associated with longer incubation periods. Interestingly, common culture conditions, such as maintaining pH and temperature, compromised the sperm DNA integrity.

关键词： density gradient centrifugation DNA damage male infertility sperm chromatin structure assay spermatozoa

Effect of insulating oil covering electrodes on the characteristics of a dielectric barrier discharge

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Plasma Science and Technology 2020年第11期22卷 36-41页

作者： Trung Nguyen TRAN Bounyang OANTHAVINSAK Shinichiro KADO Hiroto matsuura Department of Quantum and Radiation Engineering Graduate School of EngineeringOsaka Prefecture UniversitySakaiOsaka 599-8570Japan Institute of Advanced Energy Kyoto UniversityUjiKyoto 611-0011Japan

In this study,the effects of the fluid cooling and electric field line deformation were investigated in a dielectric barrier discharge(DBD)plasma *** DBD plasma jet is improved by covering the ground electrode and a power electrode with insulating *** obtained positive results as insulating oil prevents arc formation,while it improved the supplied power and plasma jet length,and increased radical *** production of this nonthermal plasma jet is studied with polyvinyl alcohol-potassium iodide liquid.

关键词： atmospheric pressure plasma jet APPJ Lissajous figure dielectric barrier discharge plasma plume

Coulometric determination of dissolved hydrogen with a multielectrolytic modified carbon felt electrode-based sensor

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Journal of Environmental Sciences 2013年第6期25卷 1077-1082页

作者： Hiroaki matsuura Yosuke Yamawaki Kosuke Sasaki Shunichi Uchiyama Department of Life Science & Green Chemistry Faculty of EngineeringSaitama Institute of Technology Department of Applied Chemistry Graduate School of EngineeringSaitama Institute of Technology

A multielectrolytic modified carbon electrode （MEMCE） was fabricated by the electrolytic-oxidation/reduction processes. First, the functional groups containing nitrogen atoms such as amino group were introduced by the electrode oxidation of carbon felt electrode in an ammonium carbamate aqueous solution, and next, this electrode was electroreduced in sulfuric acid. The redox waves between hydrogen ion and hydrogen molecule at highly positive potential range appeared in the cyclic voltammogram obtained by MEMCE. A coulometric cell using MEMCE with a catalytic activity of electrooxidation of hydrogen molecule was constructed and was used for the measurement of dissolved hydrogen. The typical current vs. time curve was obtained by the repetitive measurement of the dissolved hydrogen. These curves indicated that the measurement of dissolved hydrogen was finished completely in a very short time （ca. 10 sec）. A linear relationship was obtained between the electrical charge needed for the electrooxidation process of hydrogen molecule and dissolved hydrogen concentration. This indicates that the developed coulometric method can be used for the determination of the dissolved hydrogen concentration.

关键词： multielectrolytic modified carbon electrode (MEMCE) coulometric determination dissolved hydrogen

Improvement of a temperature response function for divertor heat flux monitoring in fusion devices

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Plasma Science and Technology 2023年第3期25卷 217-221页

作者： Xuan Nhat Son BUI Hiroto matsuura Yousuke NAKASHIMA Quantum and Radiation Engineering Department Osaka Prefecture University Plasma Research Center University of Tsukuba

Temperature response functions have been developed to investigate sensor design and divertor heat flux estimation in magnetically confined plasmas. The time-dependent heat flux can be derived by fitting the response function to experimental thermocouple(TC) data. Because the TC signals have a time delay to transit events such as discharge start or confinement transition, the time delay is taken into account in a temperature response function. Such a function accurately describes the signal from each TC channel with time delay in a sensor test using a neutral beam injection. Measurement for commercial TCs shows that the time delay is caused by the finite heat capacity of TC wire and contact heat resistance between TC and target surface.

关键词： divertor temperature response function thermocouple system primary delay