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Feasible Resolution of Angular Displacement measurement by an Optical Angle Sensor Based on Laser Autocollimation

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Nanomanufacturing and metrology 2023年第4期6卷 46-59页

作者： Hyunsung Lim Yuki shimizu Division of mechanical and Aerospace Engineering Hokkaido UniversitySapporoJapan

The feasible resolution of angular displacement measurement by an optical angle sensor based on laser autocollimation is investigated.Improving the sensor sensitivity while maintaining the noise level of the sensor signal as low as possible is necessary to achieve high-resolution angular displacement measurement.In this paper,the contribution of each component,such as a photodiode,a trans-impedance amplifer,and an analog-to-digital converter in the optical angle sensor,to the noise level of the sensor signal is frst estimated on the basis of theoretical equations.The feasible sensitivity of the optical angle sensor is also estimated in numerical calculations.The sensitivity of a photodiode element at the edge of its photosensitive area is evaluated in experiments to realize the estimation of the angle sensor sensitivity.Experimental results are applied to the numerical calculations.The infuences of the measurement laser beam diameter,the spot diameter of the focused laser beam on the photosensitive area,and the focal length of the collimator objective of the optical angle sensor are also consid-ered in the numerical calculations.Finally,a prototype optical setup is developed.Experiments are performed to demonstrate that a compact optical angle sensor based on laser autocollimation with a collimator objective having a focal length shorter than 100 mm can achieve a resolution beyond 0.001 arc-second with a bandwidth of 1 kHz.This resolution is better than those achieved by commercial autocollimators employing an image sensor or a position-sensitive detector.The industrial contribution of this paper lies in the detailed breakdown of noise components in the readout signal of an angle sensor in a practical condition and the systematic estimation of its feasible resolution as well as its sensitivity.

关键词： Angle measurement Resolution Laser autocollimation Photodiode Signal noise

On systematic development of FSI solvers in the context of particle methods

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Journal of Hydrodynamics 2022年第3期34卷 395-407页

作者： Abbas khayyer Hitoshi Gotoh Yuma shimizu Department of Civil and Earth Resources Engineering Kyoto UniversityKyotoJapan

This paper presents a review on state-of-the-art of developments corresponding to fluid-structure interaction(FSI)solvers developed within the context of particle methods.The paper reviews and highlights the potential robustness of entirely Lagrangian meshfree FSI solvers in reproducing FSI corresponding to extreme events and portrays the future perspectives for systematic developments towards reliable engineering applications with respect to rapid advances in technology and emergence of so-called advanced materials that can result in complex and highly non-linear structural responses.Accordingly,the paper highlights the necessity for reproduction of comprehensive structural responses,including viscoelastic,elastoplastic and progressive damages/failures,by the advanced FSI solvers developed within the context of particle methods.In this regard,extensions of the structure model are suggested to be conducted in a variationally consistent framework to ensure stability,accuracy and physical reliability including thermodynamic consistency.The paper reviews basics of mathematical and numerical modelling for entirely Lagrangian meshfree hydroelastic FSI solvers and presents a brief background on extensions of such solvers towards reproducing viscoelastic structural responses.Some preliminary numerical results on structural viscoelasticity achieved by an extended Hamiltonian SPH(HSPH)model are presented.This vision paper also concisely portrays the future perspectives for systematic development of particle-based FSI solvers.

关键词： Fluid-structure interaction(FSI) entirely Lagrangian meshfree smoothed particle hydrodynamics(SPH) Hamiltonian SPH(HSPH) viscoelasticity

Gut microbiota in common elderly diseases affecting activities of daily living

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World Journal of Gastroenterology 2018年第42期24卷 4750-4758页

作者： Yukihiro shimizu Gastroenterology center Nanto Municipal Hospital

Gut microbiota are involved in the development or prevention of various diseases such as type 2 diabetes,fatty liver, and malignancy such as colorectal cancer,breast cancer and hepatocellular carcinoma. Alzheimer'sdisease, osteoporosis, sarcopenia, atherosclerotic stroke and cardiovascular disease are major diseases associated with decreased activities of daily living(ADL), especially in elderly people. Recent analyses have revealed the importance of gut microbiota in the control of these diseases. The composition or diversity of these microbiota is different between patients with these conditions and healthy controls, and administration of probiotics or prebiotics has been shown effective in the treatment of these diseases. Gut microbiota may affect distant organs through mechanisms that include regulating the absorption of nutrients and/or the production of microbial metabolites, regulating and interacting with the systemic immune system, and translocating bacteria/bacterial products through disrupted mucosal barriers.Thus, the gut microbiota may be important regulators in the development of diseases that affect ADL. Although adequate exercise and proper diet are important for preventing these diseases, their combination with interventions that manipulate the composition and/or diversity of gut microbiota could be a promising strategy for maintaining health condition and preserving ADL. This review thus summarizes current understanding of the role of gut microbiota in the development or prevention of diseases closely associated with the maintenance of ADL.

关键词： Probiotics Prebiotics Alzheimer’s disease Osteoporosis Sarcopenia Gut microbiota Cardiovascular disease Cerebrovascular disease

Analyses and architectural typology of preserved traditional mosques in the old city of Herat in Afghanistan:the case of Quzzat Quarter

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Built Heritage 2022年第4期6卷 51-64页

作者： Ghulam mohammad Asim shimizu Hajime Faculty of Engineering and Science University of the Ryukyus1 Aza-SenbaruNishihara-choNakagami-gunOkinawa 903-0213Japan

The study aims to analyse the architectural typology and determine the period of construction for the preserved traditional mosques of the Quzzat Quarter in the Old City of Herat(known as the Pearl of khorasan).Twenty-nine mosques are located in the area,three of which are modern and 26 are traditional.Twelve out of the 26 traditional mosques still exist and have preserved their traditional landscape.Using analogy to analyse water cisterns and mosques,we determine when each mosque was developed and establish the period of development for each structure.Further analyses are carried out on the edifces’architectural details.Architectural analyses and mosque typologies suggest that fve buildings were built before the Timurid dynasty;two were built during the Timurid dynasty(1370−1507 CE);and one was built after the Timurid dynasty.Two mosques incorporating elements from diferent periods are counted as exceptions,and the remaining two are considered to have been built during transitional periods.

关键词： Architectural analyses Analogy Period of development Preserved traditional mosques Built heritage conservation Herat Old City Afghanistan

Petrology and phase equilibrium modeling of sapphirine ＋ quartz assemblage from the Napier Complex, East Antarctica: Diagnostic evidence for Neoarchean ultrahigh-temperature metamorphism

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Geoscience Frontiers 2013年第6期4卷 655-666页

作者： Hisako shimizu Toshiaki Tsunogae m.Santosh Graduate School of Life and Environmental Sciences University of Tsukuba Department of Geology University of Johannesburg China University of Geosciences (Beijing) Division of Interdisciplinary Science Faculty of ScienceKochi University

A synthesis of the petrological characters of granulite facies rocks that contain equilibrium sapphirine ＋ quartz assemblage from two localities （Tonagh Island （TI） and Priestley Peak （PP）） in the Napier Complex,East Antarctica,provides unequivocal evidence for extreme crustal metamorphism possibly associated with the collisional orogeny during Neoarchean.The reaction microstructures associated with sapphirine ＋ quartz vary among the samples,probably suggesting different tectonic conditions during the metamorphic evolution.Sapphirine and quartz in TI sample were probably in equilibrium at the peak stage,but now separated by corona of Grt ＋ Sil ＋ Opx suggesting near isobaric cooling after the peak metamorphism,whereas the Spr ＋ Qtz ＋ Sil ＋ Crd ＋ Spl assemblage replaces garnet in PP sample suggesting post-peak decompression.The application of mineral equilibrium modeling in NCkFmASHTO system demonstrated that Spr ＋ Qtz stability is lowered down to 930 ℃ due to small Fe3＋ contents in the rocks （mole Fe2O3/（FeO ＋ Fe2O3） =0.02）.The TI sample yields a peak p-T range of 950-1100 ℃ and 7.5-11 kbar,followed by cooling toward a retrograde stage of 800-950 ℃ and 8-10 kbar,possibly along a counterclockwise p-T path.In contrast,the peak condition of the PP sample shows 1000-1050 ℃ and ＞12 kbar,which was followed by the formation ofSpr ＋ Qtz corona around garnet at 930-970 ℃ and 6.7-7.7 kbar,suggesting decompression possibly along a clockwise p-T trajectory.Such contrasting p-T paths are consistent with a recent model on the structural framework of the Napier Complex that correlates the two areas to different crustal blocks.The different p-T paths obtained from the two localities might reflect the difference in the tectonic framework of these rocks within a complex Neoarchean subduction/collision belt.

关键词： Ultrahigh-temperature granulite Petrology Pseudosection modeling Napier complex Antarctica

Physical features and analysis of traditional mosques:the case of Quzzat quarter of Herat Old City,Afghanistan

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Built Heritage 2023年第3期7卷 1-17页

作者： Ghulam mohammad Asim Hajime shimizu Faculty of Engineering and Science The University of the Ryukyus1 Aza-SenbaruNishihara-ChoNakagami-GunOkinawa903-0213Japan

This study examines the physical features of traditional mosques in the Quzzat(Bardrani)quarter of Herat Old City,Afghanistan.Traditional mosques are constructed with locally available materials and are planned based on cultural and climatic conditions.mosques are categorised as modern or traditional.Traditional mosques are divided into three subcategories:preserved,damaged(defaced),and transformed.Transformed mosques are formerly traditional mosques reconstructed with modern or industrial materials(concrete and reinforcement).This study explores the distribution of mosques and analyses their plan typology.mosques are categorised into five plan types,and three relative case studies are described in detail to provide a better understanding and an in-depth analysis of mosque typology.

关键词： Physical features Spatial and architectural analyses Traditional mosques Built heritage conservation Herat Old City Afghanistan

New developments in high-pressure X-ray diffraction beamline for diamond anvil cell at SPring-8

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matter and Radiation at Extremes 2020年第1期5卷 49-58页

作者： N.Hirao S.I.kawaguchi k.Hirose k.shimizu E.Ohtani Y.Ohishi Japan Synchrotron Radiation Research Institute SayoHyogo 679-5198Japan Department of Earth and Planetary Science The University of TokyoTokyo 113-0033Japan Earth-Life Science Institute Tokyo Institute of TechnologyTokyo 152-8550Japan Center of Science and Technology Under Extremes Conditions Graduate School of Engineering ScienceOsaka UniversityOsaka 560-8531Japan Department of Earth Science Graduate School of ScienceTohoku UniversitySendai 980-8578Japan

An overview of the recently renovated high-pressure X-ray diffraction(XRD)BL10XU beamline for the diamond anvil cell at SPring-8 is presented.The renovation includes the replacement of the X-ray source and monochromator,enhanced focusing systems for high-energy XRD,and recent progress in the sample environment control techniques that are available for high-pressure studies.Other simultaneous measurement techniques for combination with XRD,such as Raman scattering spectroscopy and mossbauer spectroscopy,have been developed to obtain complementary information under extreme conditions.These advanced techniques are expected to make significant contributions to in-depth understanding of various and complicated high-pressure phenomena.The experience gained with the BL10XU beamline could help promote high-pressure research in future synchrotron radiation facilities.

关键词： beam gained extreme

microstructure and phase elemental distribution in high-boron multicomponent cast irons

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International Journal of minerals,metallurgy and materials 2022年第1期29卷 78-87页

作者： Yu.G.Chabak k.shimizu V.G.Efremenko m.A.Golinskyi k.kusumoto V.I.Zurnadzhy A.V.Efremenko Physics Department Pryazovskyi State Technical UniversityMariupol87555Ukraine mechanical Engineering Research Unit College of Design and Manufacturing TechnologyMuroran Institute of TechnologyMuroran-city050-8585Japan

The novel cast irons of chemical composition(wt%)0.7C-5W-5mo-5V-10Cr-2.5Ti were invented with the additions of 1.6wt%B and 2.7wt%B.The aim of this work was to study the effect of boron on the structural state of the alloys and phase elemental distribution with respect to the formation of wear-resistant structural constituents.It was found that the alloy containing 1.6wt%B was composed of three eutectics:(a)“m_(2)(C,B)_(5)+ferrite”having a“Chinese Script”morphology(89.8vol%),(b)“m_(7)(C,B)_(3)+Austenite”having a“Rosette”morphology,and(c)“m_(3)C+Austenite”having a“Ledeburite”-shaped morphology(2.7vol%).With 2.7wt%of boron content,the bulk hardness increased from HRC 31 to HRC 38.5.The primary carboborides m_(2)(C,B)_(5) with average microhardness of HV 2797 appeared in the structure with a volume fraction of 17.6vol%.The volume fraction of eutectics(a)and(b,c)decreased to 71.2vol%and 3.9vol%,respectively.The matrix was“ferrite/austenite”for 1.6wt%B and“ferrite/pearlite”for 2.7wt%B.Both cast irons contained compact precipitates of carbide(Ti,m)C and carboboride(Ti,m)(C,В)with a volume fraction of 7.3%-7.5%.Based on the energy-dispersive X-ray spectroscopy,the elemental phase distributions and the appropriate phase formulas are presented in this work.

关键词： multi-component cast iron boron eutectic carbide carboboride

T cell immunopathogenesis and immunotherapeutic strategies for chronic hepatitis B virus infection

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World Journal of Gastroenterology 2012年第20期18卷 2443-2451页

作者： Yukihiro shimizu Gastroenterology Unit Takaoka City Hospital 4-1 Takara-machi Takaoka city Toyama 933-8550 Japan

Hepatitis B is caused by the host immune response and T cells play a major role in the immunopathogenesis. more importantly,T cells not only destroy hepatocytes infected by hepatitis B virus(HBV),but also control HBV replication or eradicate HBV in a noncytolytic manner.Therefore,analysis of T cell immune response during acute and chronic HBV infection is important to develop a strategy for successful viral control,which could lead to immunotherapy for terminating persistent HBV infection.There have been many attempts at immunotherapy for chronic HBV infection,and some have shown promising results.High viral load has been shown to suppress antiviral immune responses and immunoinhibitory signals have been recently elucidated, therefore,viral suppression by nucleos(t)ide analogs, stimulation of antiviral immune response,and suppression of the immunoinhibitory signals must be combined to achieve desirable antiviral effects.

关键词：慢性乙型肝炎病毒感染免疫治疗 T细胞免疫病理免疫反应乙肝病毒抗病毒药