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Round Robin Study on the Thermal Conductivity/Diffusivity of a Gold Wire with a Diameter of 30μm Tested via Five Measurement Methods

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Journal of Thermal Science 2022年第4期31卷 1037-1051页

作者： ABE Ryo SEKIMOTO Yuki SAINI Shirkant MIYAZAKI koji LI Qin-Yi LI Dawei takahashi Koji YAGI Takashi NAKAMURA Masakazu division of materials science nara institute of science and technologyikoma 630-0192japan department of mechanical and control engineering kyushu institute of technologykitakyushu 804-8550japan department ofaeronautics and astronautics kyushu universityfukuoka819-0395japan international institute for carbon-neutral energy research(wpi-i2cner) kyushu universityfukuoka 819-0395japan national metrology institute of japan national institute of advanced industrial science and technology tsukuba 305-8565japan

Since first establishing thermal measurement techniques for micrometer-scale wires,various methods have been devised and improved upon.However,the uncertainty of different measurements on the same sample has not yet been discussed.In this work,a round robin test was performed to compare the thermal conductivity and thermal diffusivity measurement methods for a fine metal wire.The tested material was a pure gold wire,with a diameter of 30μm.The wire was cut into certain lengths and distributed to four institutions using five different measurement methods:the direct current(DC)self-heating method,the DC heating T-type method,the 3ωmethod for thermal conductivity,the scanning laser heating alternating current(AC)method,and the spot periodic heating radiation thermometry method for thermal diffusivity.After completing the measurements,the reported thermal conductivity and thermal diffusivity at room temperature,i.e.,317 W·m^(-1)·K^(-1)and 128×10^(-6)m^(2)·s^(-1),respectively,were adopted as references for comparison with the measurement results.The advantages and disadvantages of each method are described in terms of the effect of electrical and thermal junctions fabricated on a wire,such as an electrode,a thermocouple,and a heat bath.The knowledge obtained from the tested methods will be useful for selecting and designing a measurement technique for various wire-like materials.

关键词： thermal conductivity thermal diffusivity round robin test microscale wire

Application of Simple Adaptive Control to Water Hydraulic Servo Cylinder System

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Chinese Journal of Mechanical Engineering 2012年第5期25卷 882-888页

作者： ITO Kazuhisa YAMADA Tsuyoshi IKEO Shigeru takahashi Koji College of Systems Engineering and Science Shibaura Institute of Technology Saitama 3378570 Japan Graduate School of Mechanical Engineering Tottori UniversityTottori 6808552 Japan Department of Mechanical Engineering Sophia UniversityTokyo 1028554 Japan

Although conventional model reference adaptive control （MRAC） achieves good tracking performance for cylinder control, the controller structure is much more complicated and has less robustness to disturbance in real applications. This paper discusses the use of simple adaptive control （SAC） for positioning a water hydraulic servo cylinder system. Compared with MRAC, SAC has a simpler and lower order structure, i.e., higher feasibility. The control performance of SAC is examined and evaluated on a water hydraulic servo cylinder system. With the recent increased concerns over global environmental problems, the water hydraulic technique using pure tap water as a pressure medium has become a new drive source comparable to electric, oil hydraulic, and pneumatic drive systems. This technique is also preferred because of its high power density, high safety against fire hazards in production plants, and easy availability. However, the main problems for precise control in a water hydraulic system are steady state errors and overshoot due to its large friction torque and considerable leakage flow. MRAC has been already applied to compensate for these effects, and better control performances have been obtained. However, there have been no reports on the application of SAC for water hydraulics. To make clear the merits of SAC, the tracking control performance and robustness are discussed based on experimental results. SAC is confirmed to give better tracking performance compared with PI control, and a control precision comparable to MRAC （within 10 μm of the reference position） and higher robustness to parameter change, despite the simple controller. The research results ensure a wider application of simple adaptive control in real mechanical systems.

关键词： water hydraulics servo cylinder system positioning control simple adaptive control

Charge and Heat Transport in Polycrystalline Metallic Nanostructures

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Chinese Physics Letters 2008年第9期25卷 3360-3363页

作者：张兴 takahashi Koji FUJII Motoo Key Laboratory for Thermal Science and Power Engineering of Ministry of Education Department of Engineering Mechanics Tsinghua University Beijing 100084 Graduate School of Engineering Kyushu University Fukuoka 819-0395 Japan Research Center for Hydrogen Industrial Use and Storage AIST Fhkuoka 819-0395 Japan

金属典型地是搬运充电并且搬运热的能力能通过 Wiedemann-Franz 法律是相关的好在导体。这里，我们在搬运充电的能力比那更显然在被削弱搬运热的多晶的金属性的 nanostructures 在反常费用和热运输上报导。我们把它归因于内部谷物边界... 详细信息

金属典型地是搬运充电并且搬运热的能力能通过 Wiedemann-Franz 法律是相关的好在导体。这里，我们在搬运充电的能力比那更显然在被削弱搬运热的多晶的金属性的 nanostructures 在反常费用和热运输上报导。我们把它归因于内部谷物边界的影响并且提出了一种新奇关系预言热传导性。Wiedemann-Franz 法律然后被修改与现在与测量结果同意很好的预言说明对起诉和热运输的谷物边界的影响。[从作者抽象]

关键词：多晶金属纳米结构热传递导电性

Experimental study on the in-plane thermal conductivity of Au nanofilms

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Progress in Natural Science:Materials International 2007年第2期17卷 212-216页

作者： takahashi Koji IKUTA Tatsuya FUJII Motoo Fukuoka 812-8581 Graduate School of Engineering Kyushu University Institute for Materials Chemistry and Engineering Japan Kasuga 816-8580

The in-plane thermal conductivity of Au nanofilms with thickness of 23 nm, which are fabricated by the electron beam-physical vapor deposition method and a suspension technology, is experimentally measured at 80-300 K by a one-dimensional steady-state electrical heating method. Strong size effects are found on the measured nanofilm thermal conductivity. The Au nanofilm in-plane thermal conductivity is much less than that of the bulk material. With the increasing temperature, the nanofilm thermal conductivity increases. This is opposite to the temperature dependence of the bulk property. The Lorenz number of the Au nanofilms is about three times larger than the bulk value and decreases with the increasing temperature, which indicates the invalidity of the Wiedemann-Franz law for metallic nanofilms.

关键词： nanofilm in-plane thermal conductivity size effect Wiedemann-Franz law.

Different effects of grain boundary scattering on charge and heat transport in polycrystalline platinum and gold nanofilms

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Chinese Physics B 2009年第5期18卷 2035-2040页

作者：马维刚王海东张兴 takahashi Koji Key Laboratory for Thermal Science and Power Engineering of Ministry of Education Department of Engineering MechanicsTsinghua University Graduate School of Engineering Kyushu University

The in-plane electrical and thermal conductivities of several polycrystalline platinum and gold nanofilms with different thicknesses are measured in a temperature range between the boiling point of liquid nitrogen （77K） and room temperature by using the direct current heating method. The result shows that both the electrical and thermal conductivities of the nanofilms reduce greatly compared with their corresponding bulk values. However, the electrical conductivity drop is considerably greater than the thermal conductivity drop, which indicates that the influence of the internal grain boundary on heat transport is different from that of charge transport, hence leading to the violation of the Wiedemann-Franz law. We build an electron relaxation model based on Matthiessen＇s rule to analyse the thermal conductivity and employ the Mayadas ＆ Shatzkes theory to analyse the electrical conductivity. Moreover, a modified Wiedemann-Franz law is provided in this paper, the obtained results from which are in good agreement with the experimental data.

关键词： polycrystalline nanofilm grain boundary scattering thermal and electrical conductivities Wiedemann-Franz law

Light chain cardiac amyloidosis in a nonagenarian

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Journal of Geriatric Cardiology 2022年第1期19卷 83-89页

作者： koji takahashi Mina Yamashita Tomoki Sakaue Daijiro Enomoto Shigeki Uemura Takafumi Okura Shuntaro Ikeda Takanori Senba Akira Saijo Nobuhisa Yamamura Sohei Kitazawa Department of Community Emergency Medicine Ehime University Graduate School of MedicineEhimeJapan Department of Cardiology Yawatahama City General HospitalEhimeJapan Department of Hematology Yawatahama City General HospitalEhimeJapan Department of Clinical Pathology Yawatahama City General HospitalEhimeJapan Department of Molecular Pathology Ehime University Graduate School of MedicineEhimeJapan

Cardiac amyloidosis is an infiltrative and restrictive cardiomyopathy caused by the extracellular deposition of amyloid fib-rils within the heart as systemic amyloidosis,lead-ing to heart failure,reduced quality of life,and death.[1]There are two major amyloid fibril proteins that af-fect the heart:amyloid immunoglobulin light chain(AL)and amyloid transthyretin(ATTR).The latter is further subdivided into wild-type ATTR and variant types based on the presence of a mutation in the transthyretin gene.

关键词： amyloid death. cardiomyopathy

Experimental Studies on Thermal and Electrical Properties of Platinum Nanofilms

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Chinese Physics Letters 2006年第4期23卷 936-938页

作者：张兴张清光曹炳阳 FUJII Motoo takahashi Koji IKUTA Tatsuya Key Laboratory for Thermal Science and Power Engineering of Ministry of Education Tsinghua University Beijing 100084 Institute for Materials Chemistry and Engineering Kyushu University Kasuga 816-8580 Japan Graduate School of Engineering Kyushu University Fukuoka 812-8581 Japan

We experimentally studied the in-plane thermal and electrical properties of a suspended platinum nanofilm in thickness of 15 nm. The measured results show that the in-plane thermal conductivity, the electrical conductivity and the resistance-temperature coefficient of the studied nanofilm are much less than those of the bulk material, while the Lorenz number is greater than the bulk value. Comparing with the results reported previously for the platinum nanofilm in thickness of 28 nm, we further find that the in-plane thermal conductivity, the electrical conductivity and the resistance-temperature coefficient decrease with the decreasing thickness of the nanotilm, while the Lorenz number increases with the decreasing thickness of the nanofilm. These results indicate that strong size effects exist on the in-plane thermal and electrical properties of platinum nanofilms.

关键词： TRANSPORT CONDUCTIVITY SUPERLATTICES PHONON

Non-Fourier heat conduction study for steady states in metallic nanofilms

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Chinese Science Bulletin 2012年第24期57卷 3239-3243页

作者： WANG HaiDong LIU JinHui GUO ZengYuan takahashi Koji Key Laboratory for Thermal Science and Power Engineering of Ministry of Education School of AerospaceTsinghua UniversityBeijing 100084China Graduate School of Engineering Kyushu UniversityFukuoka 819-0395Japan

As a fundamental theory of heat transfer, Fourier's law is valid for most traditional conditions. Research interest in non-Fourier heat conditions is mainly focused on heat wave phenomena in non-steady states. Recently, the thermomass theory posited that, for steady states, non-Fourier heat conduction behavior could also be observed under ultra-high heat flux conditions at low ambient temperatures. Significantly, this is due to thermomass inertia. We report on heat conduction in metallic nanofilms from large currents at low temperatures; heat fluxes of more than 1×1010 W m 2 were used. The measured average temperature of the nanofilm is larger than that based on Fourier's law, with temperature differences increasing as heat flux increased and ambient temperature decreased. Experimental results for different film samples at different ambient temperatures reveal that non-Fourier behavior exists in metallic nanofilms in agreement with predictions from thermomass theory.

关键词：非傅立叶热传导非稳定状态纳米薄膜金属低环境温度 Fourier 傅立叶定律高热通量

Cortical transcriptome analysis after spinal cord injury reveals the regenerative mechanism of central nervous system in CRMP2 knock-in mice

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Neural Regeneration Research 2021年第7期16卷 1258-1265页

作者： Ayaka Sugeno Wenhui Piao Miki Yamazaki Kiyofumi takahashi koji Arikawa Hiroko Matsunaga Masahito Hosokawa Daisuke Tominaga Yoshio Goshima Haruko Takeyama Toshio Ohshima Laboratory for Molecular Brain Science Department of Life Science and Medical BioscienceGraduate School of Advanced Science and EngineeringWaseda UniversityTokyoJapan Biomolecular Engineering Laboratory Department of Life Science and Medical BioscienceGraduate School of Advanced Science and EngineeringWaseda UniversityTokyoJapan Computational Bio Big-Data Open Innovation Laboratory(CBBD-OIL) National Institute of Advanced Industrial Science and Technology(AIST)TokyoJapan Research Organization for Nano and Life Innovation Waseda UniversityTokyoJapan Institute for Advanced Research of Biosystem Dynamics Waseda Research Institute for Science and EngineeringGraduate School of Advanced Science and EngineeringWaseda UniversityTokyoJapan Cellular and Molecular Biotechnology Research Institute National Institute of Advanced Industrial Science and Technology(AIST)TsukubaJapan Department of Molecular Pharmacology and Neurobiology Graduate School of MedicineYokohama City UniversityYokohamaJapan

Recent studies have shown that mutation at Ser522 causes inhibition of collapsin response mediator protein 2(CRMP2) phosphorylation and induces axon elongation and partial recovery of the lost sensorimotor function after spinal cord injury(SCI).We aimed to reveal the intracellular mechanism in axotomized neurons in the CRMP2 knock-in(CRMP2KI) mouse model by performing transcriptome analysis in mouse sensorimotor cortex using micro-dissection punching system.Prior to that, we analyzed the structural pathophysiology in axotomized or neighboring neurons after SCI and found that somatic atrophy and dendritic spine reduction in sensorimotor cortex were suppressed in CRMP2KI mice.Further analysis of the transcriptome has aided in the identification of four hemoglobin genes Hba-a1, Hba-a2, Hbb-bs, and Hbb-bt that are significantly upregulated in wild-type mice with concomitant upregulation of genes involved in the oxidative phosphorylation and ribosomal pathways after SCI.However, we observed substantial upregulation in channel activity genes and downregulation of genes regulating vesicles, synaptic function, glial cell differentiation in CRMP2KI mice.Moreover, the transcriptome profile of CRMP2KI mice has been discussed wherein energy metabolism and neuronal pathways were found to be differentially regulated.Our results showed that CRMP2KI mice displayed improved SCI pathophysiology not only via microtubule stabilization in neurons, but also possibly via the whole metabolic system in the central nervous system, response changes in glial cells, and synapses.Taken together, we reveal new insights on SCI pathophysiology and the regenerative mechanism of central nervous system by the inhibition of CRMP2 phosphorylation at Ser522.All these experiments were performed in accordance with the guidelines of the Institutional Animal Care and Use Committee at Waseda University, Japan(2017-A027 approved on March 21, 2017;2018-A003 approved on March 25, 2018;2019-A026 approved on March 25, 2019).

关键词： CNS regeneration cortex CRMP2 hemoglobin metabolic pathway spinal cord injury spine transcriptome