論文 - 山下　誠司

Novel Sodium Chloride/Aluminum Oxide Powder-Composite Structure with High Shape-Retention Performance for the Encapsulation of a High-Temperature Phase-Change Material 査読有り 国際共著

Processes   12 巻 ( 3 ) 頁： 465 - 479   2024年12月

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担当区分：筆頭著者   記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： https://doi.org/10.3390/pr12030465

Microstructure modification of alumina prepared by water-stabilized plasma spraying method using Al-Cu-O reaction 査読有り

Fuhai Bao, Seiji Yamashita, Hajime Daki, Keita Nakagawa, Hideki Kita,

Journal of the European Ceramic Society     2024年3月

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担当区分：責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： https://doi.org/10.1016/j.jeurceramsoc.2024.03.016

Water Vapor Adsorption Behavior of Thermosensitive Polymers for Desiccant Humidity Control Systems

Kubota Mitsuhiro, Nakai Ryosuke, Yamashita Seiji, Kita Hideki, Tokuyama Hideaki

ISIJ International   62 巻 ( 12 ) 頁： 2536 - 2541   2022年12月

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記述言語：英語   出版者・発行元：The Iron and Steel Institute of Japan  

<p>Desiccant humidity control systems have been garnering considerable attention in the attempt to achieve highly efficient utilization of low-temperature heat exhausted from various industries at temperatures less than 373 K. We have focused on thermosensitive polymers as new desiccants because a large amount of dehumidified water would be expected in the system because of their thermosensitivity. Our previous study focused on the water adsorption behavior of poly(N-isopropylacrylamide) (poly(NIPA)), which has a low critical solution temperature (LCST) of 306 K. In this study, poly(N-isopropylmethacrylamide) (poly(NIPMA)) and poly(2-(dimethylamino)ethyl methacrylate) (poly(DMAEMA)) cross-linked with N,N′-methylenebisacrylamide (MBAA) were investigated. These polymers are known to exhibit thermosensitivity in the temperature range of 313–319 K in water, which is a higher LCST than that of poly(NIPA). Poly(NIPMA) adsorbed water vapor linearly with increasing relative humidity. It was also observed that poly(NIPMA) prepared at MBAA concentrations of 200 mol/m³ exhibited a thermosensitivity in the temperature range of 303–313 K in water vapor adsorption. Meanwhile, poly(DMAEMA) adsorbed little water vapor up to a relative humidity (RH) of 40%; however, it exponentially adsorbed water at RH levels higher than 40%. From the estimation results of effective water adsorptivity, we found that poly(DMAEMA) is applicable in desiccant humidity control systems when the dehumidification process is performed at high RH.</p>

DOI： 10.2355/isijinternational.isijint-2022-204

CiNii Research

マハラノビス－タグチ（MT）法を用いたカブトムシ三齢幼虫糞形状による雌雄判別

高井（山下） 千加, 山下 誠司, 馬渕 裕也, 寺前 敦史, 松山 拓矢, 田口 裕己, 虫鹿 太賀, 和田 雄也, Shinta Fitria Novasari, 大矢 豊

粉体工学会誌   59 巻 ( 12 ) 頁： 620 - 627   2022年12月

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記述言語：日本語   出版者・発行元：一般社団法人 粉体工学会  

DOI： 10.4164/sptj.59.620

CiNii Research

Low-Temperature Joining of B4C Ceramics Using Cold-Sprayed Al-8wt%Si Alloy and Microstructure of the Vicinity of the Joint Interface 招待有り 査読有り

  10 巻 ( 12 )   2022年12月

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： https://doi.org/10.3390/pr10122573

Aluminum Electrodeposition on the Surface of Boron Carbide Ceramics by Use EMIC–AlCl3 Ions Liquid 査読有り

Roujia Gou,Jae-Hyeok Park , Seiji Yamashita, Takeshi Hagio, Ryoichi Ichino and Hideki Kita

Coatings   12 巻   2022年10月

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： https://doi.org/10.3390/coatings12101535

Storage and heat dissipation behavior of a heat storage ball with an Al–xSi alloy core and alumina ceramic shell 査読有り

Xin Zhou, Fuhai Bao, Seiji Yamashita, Mitsuhiro Kubota Hideki Kita

Journal of Energy Storage   52 巻   2022年8月

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： https://doi.org/10.1016/j.est.2022.104955

Effect of Counterbody on Friction and Wear Properties of Copper-MgP-Graphite Composites Prepared by Powder Metallurgy 招待有り 査読有り

Ruoxuan Li , Seiji Yamashita, Katsumi Yoshida and Hideki Kita

Processes   10 巻   頁： 804   2022年4月

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DOI： https://doi.org/10.3390/pr10050804

Microstructural analysis of network-like crack structure formed at Al–B4C interface 招待有り 査読有り

Roujia Gou, Seiji Yamashita, Kiyoto Sekine, Hideki Kita

Journal of the European Ceramic Society   41 巻 ( 14 ) 頁： 6962 - 6970   2022年3月

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DOI： https://doi.org/10.1016/j.jeurceramsoc.2021.06.043.

Encapsulated Copper-Based Phase-Change Materials for High-Temperature Heat Storage. 招待有り 査読有り

Zhou X, Yamashita S, Kubota M, Kita H

ACS omega   7 巻 ( 6 ) 頁： 5442 - 5452   2022年2月

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記述言語：英語  

DOI： 10.1021/acsomega.1c06751

PubMed

Effects of Additional Mullite Micro-Powder on Rheological Behavior of Highly Concentrated Aqueous Silicon Slurry

Himoto Iori, Kita Hideki, Shenghao Liao, Yamashita Seiji

JOURNAL OF CHEMICAL ENGINEERING OF JAPAN   54 巻 ( 11 ) 頁： 586 - 592   2021年11月

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記述言語：英語   出版者・発行元：The Society of Chemical Engineers, Japan  

<p>Low-thermal-conductive reaction-bonded silicon nitride (RBSN), with a thermal conductivity of 8.08 W/(m·K), was developed by the addition of mullite micro-powder as a rare-earth-free oxide sintering agent to silicon nitride. This addition was expected to generate a glassy grain boundary as well as a solid solution of oxygen across the microstructure of the RBSN, which leads to low thermal conductivity. During the fabrication of a heat-insulating component with a hollow structure made of the RBSN via slip casting and subsequent reaction sintering, it was found that the viscosity of aqueous silicon-mullite slurries decreased evidently by the addition of the mullite micro-powder with ammonium polycarboxylate as a dispersant. The viscosity decreased even though the pH (7–8) of the slurries were maintained, and the particle size distributions did not vary significantly. At the effective mullite content when the viscosity decrease was attained, the ratio of the number of particles of mullite to silicon was approximately 1. Therefore, the viscosity decrease in Si slurry (50 vol%) was primarily caused by the steric hindrance due to the adsorption of dispersant by the mullite particles, preventing the direct contact among the silicon particles, rather than by electrostatic repulsions among the silicon particles. This was also explained through the modality of bimodal dispersion. Thus, it was found that the mullite not only acts as a sintering agent but also facilitates viscosity decrease of highly concentrated aqueous Si slurry, which successfully enables the integration of the slip casting and reaction sintering processes.</p>

DOI： 10.1252/jcej.20we173

CiNii Research

7-2-3　エクセルギー解析グラフツールの開発とその生産プロセスへの適用

北 英紀, 山下 誠司, 窪田 光宏

日本エネルギー学会大会講演要旨集   30 巻 ( 0 ) 頁： 166 - 167   2021年7月

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記述言語：日本語   出版者・発行元：一般社団法人 日本エネルギー学会  

DOI： 10.20550/jietaikaiyoushi.30.0_166

CiNii Research

Effects of Additional Mullite Micro-Powder on Rheological Behavior of Highly Concentrated Aqueous Silicon Slurry 招待有り 査読有り

Iori Himoto, Hideki Kita, Liao Shenghao, Seiji Yamashita

JOURNAL OF CHEMICAL ENGINEERING OF JAPAN   54 巻 ( 11 ) 頁： 586 - 592   2021年7月

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担当区分：責任著者  

DOI： https://doi.org/10.1252/jcej.20we173

Investigation of Sr-based perovskites for redox-type thermochemical energy storage media at medium-high temperature 招待有り 査読有り

XiaoyuChen MitsuhiroKubota SeijiYamashita HidekiKita

Journal of Energy Storage     2021年6月

A study of B4C-SiC composite for self-lubrication

Zhang Wei, Yamashita Seiji, Kita Hideki

JOURNAL OF THE AMERICAN CERAMIC SOCIETY   104 巻 ( 5 ) 頁： 2325 - 2336   2021年5月

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DOI： 10.1111/jace.17584

Web of Science

Investigating the chemical bonding state of graphite powder treated with magnesium(II) phosphate through EELS, TEM, and XPS analysis 招待有り 査読有り

RuoxuanLi SeijiYamashita HidekiKita

Diamond and Related Materials     2021年4月

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担当区分：責任著者  

DOI： https://doi.org/10.1016/j.diamond.2021.108423.

Effect of Water Temperature on Tribological Performance of B4C-SiC Ceramics under Water Lubrication

Zhang Wei, Chen Xiaoyu, Yamashita Seiji, Kubota Mitsuhiro, Kita Hideki

TRIBOLOGY LETTERS   69 巻 ( 2 )   2021年2月

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DOI： 10.1007/s11249-021-01406-0

Web of Science

Effect of counterbody on tribological properties of B4C-SiC composite ceramics

Zhang Wei, Yamashita Seiji, Kita Hideki

WEAR   458 巻   2020年10月

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DOI： 10.1016/j.wear.2020.203418

Web of Science

7-12　人工物製造プロセスのエクセルギー解析

北 英紀, 山下 誠司, 窪田 光宏

日本エネルギー学会大会講演要旨集   29 巻 ( 0 ) 頁： 188 - 189   2020年7月

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記述言語：日本語   出版者・発行元：一般社団法人 日本エネルギー学会  

DOI： 10.20550/jietaikaiyoushi.29.0_188

CiNii Research

Tribological Properties of B4C Ceramics Prepared by Pressureless Sintering and Annealed at Different Temperatures

Zhang Wei, Yamashita Seiji, Kumazawa Takeshi, Ozeki Fumihito, Hyuga Hideki, Kita Hideki

TRIBOLOGY TRANSACTIONS   63 巻 ( 4 ) 頁： 672 - 682   2020年7月

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DOI： 10.1080/10402004.2020.1734705

Web of Science