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Photocatalytic unification of iodine species using platinum-loaded titanium dioxide

杉田 剛; 森 勝伸*; 香西 直文

Journal of Photochemistry and Photobiology A; Chemistry, 438, p.114548_1 - 114548_6, 2023/04

原子力事故や放射性廃棄物の放出によって汚染された水からヨウ素を除去することは、水中に様々な形でヨウ素が存在するため、複雑でコストがかかる。そこで、水中の放射性ヨウ素を除去するための前処理として、光触媒によるヨウ素種の統一を検討した。ヨウ化物(I$$^{-}$$), ヨウ素酸(IO$$_3^{-}$$), o-ヨード安息香酸の光触媒酸化還元反応に及ぼすPt-TiO$$_{2}$$結晶相と溶液pHの影響を評価した。TiO$$_{2}$$結晶相とpHの選択により、混合されたヨウ素種をI$$^{-}$$またはIO$$_3^{-}$$のみに統一することができた。Pt-TiO$$_{2}$$の種類に関係なく、アルカリ性条件下でo-ヨード安息香酸中のヨウ素はI$$^{-}$$に無機化された。光触媒と溶液のpHを選択することでヨウ素種を単一化できるため、この光触媒処理は高効率でヨウ素種を除去するために適用できると考えられる。


令和3年度研究開発・評価報告書 評価課題「中性子及び放射光利用研究開発」(事前評価)


JAEA-Evaluation 2022-013, 105 Pages, 2023/03




令和3年度研究開発・評価報告書 評価課題「中性子及び放射光利用研究開発」(事後評価)


JAEA-Evaluation 2022-012, 87 Pages, 2023/03




Corrosion fatigue crack growth behavior of a structurally gradient steel for high-speed railway axles

Ao, N.*; Zhang, H.*; Xu, H. H.*; Wu, S. C.*; Liu, D.*; 徐 平光; Su, Y. H.; Kang, Q. H.*; Kang, G. Z.*

Engineering Fracture Mechanics, 281, p.109166_1 - 109166_14, 2023/03

Considering the complex service environments that high-speed railway axles are subjected to, the fatigue crack growth (FCG) behavior of a structurally gradient axle steel with different pre-crack depths both in air and corrosive medium was investigated at a frequency of 5 Hz. The results indicated that in the high $$Delta$$$$K$$ region, FCG rate was dramatically accelerated by corrosion, but the gap narrows as $$Delta$$$$K$$ decreased. The accelerated corrosion FCG rate was a comprehensive result of the acceleration effect of the anodic dissolution, hydrogen-enhanced localized plasticity and the retardation effect of corrosion-induced crack-tip blunting. Despite the fact that the corrosion resistance gradually decreased as the pre-crack depth increased, the FCG rate in the corrosive medium gradually decreased. This was because fatigue loading played a more important role than corrosion in accelerating the corrosion FCG rate.


Hierarchical aggregation in a complex fluid; The Role of isomeric interconversion

Massey, D.*; Williams, C. D.*; Mu, J.*; Masters, A. J.*; 元川 竜平; 青柳 登; 上田 祐生; Antonio, M. R.*

Journal of Physical Chemistry B, 127(9), p.2052 - 2065, 2023/03

There is an ever-increasing body of evidence that metallic complexes, involving amphiphilic ligands, do not form normal solutions in organic solvents. Instead, they form complex fluids with intricate structures. For example, the metallic complexes may aggregate into clusters and these clusters themselves may aggregate into super-clusters. In order to gain a deeper insight into the mechanisms at play, we have used an improved force field to conduct extensive molecular dynamics simulations of a system composed of zirconium nitrate, water, nitric acid, tri-$$n$$-butyl phosphate and $$n$$-octane. The important new finding is that a dynamic equilibrium between the cis and trans isomers of the metal complex is likely to play a key role in the aggregation behavior. The isolated cis and trans isomers have similar energies but simulation indicates that the clusters consist predominantly of cis isomers. With increasing metal concentration, we hypothesize that more clustering occurs and the chemical equilibrium shifts towards the cis isomer. It is possible that such isomeric effects play a role in the liquid-liquid extraction of other species and the inclusion of such effects in flowsheet modelling may lead to a better description of the process.


Compressive deformation behavior of AZ31 alloy at 21K; An ${it In situ}$ neutron diffraction study

Gong, W.; 川崎 卓郎; Zheng, R.*; 眞山 剛*; Sun, B.*; 相澤 一也; Harjo, S.; 辻 伸泰*

Scripta Materialia, 225, p.115161_1 - 115161_5, 2023/03

 被引用回数:0 パーセンタイル:0.05(Nanoscience & Nanotechnology)

Deformation behavior during uniaxial compression at 21 K and 298 K in a commercial AZ31 magnesium alloy was studied by ${it in situ}$ neutron diffraction. Decreasing the deformation temperature resulted in a slight increase in yield stress (115 MPa $$rightarrow$$ 139 MPa), but a remarkable enhancement in both the fracture stress (365 MPa $$rightarrow$$ 551 MPa) and fracture strain (12.8% $$rightarrow$$ 16.5%). The low temperature sensitivity of the {10$$overline{1}$$2} extension twinning which governed the macroscopic yielding led to the slight increase in yield stress. At 21K, basal slip was suppressed, while the extension twinning was promoted resulted in higher twin volume fraction. In the late stage of deformation, the {10$$overline{1}$$1}-{10$$overline{1}$$2} double twinning was suppressed, which is considered to be the reason to delay the fracture at 21 K.



徳永 翔; 井口 晋太郎; 川村 奨; 平根 伸彦

JAEA-Technology 2022-004, 74 Pages, 2023/02




JRR-3 1次冷却材熱交換器の開放点検

宇野 裕基; 大内 靖弘; 大内 諭; 馬場 亮太; 菊地 将宣; 川又 諭

JAEA-Technology 2021-046, 39 Pages, 2023/02


JRR-3(Japan Research Reactor No.3)は、最大熱出力20MWの低濃縮ウラン軽水減速軽水冷却プール型研究用原子炉である。平成2年11月から改造後の供用運転を開始し、各種照射設備及び中性子ビーム実験装置を装備した原子炉施設として高い中性子束を利用者に提供している。現在は、平成23年3月11日の東日本大震災の影響により延長していた施設定期自主検査期間を経て、新規制基準の適合性に対応し、約10年ぶりとなる運転の再開を果たしている。早期運転再開を目指す施設定期自主検査期間中の平成29年度には、保全計画に基づく1次冷却材熱交換器No.1及びNo.2の開放点検を実施した。本報告書は1次冷却材熱交換器の開放点検について、点検記録及び点検実績を纏めるとともに今後の点検保守に資するためのものである。



川村 奨; 菊地 将宣; 細谷 俊明

JAEA-Technology 2021-041, 103 Pages, 2023/02





菊地 将宣; 川村 奨; 細谷 俊明

JAEA-Technology 2021-040, 86 Pages, 2023/02




Tensile overload-induced texture effects on the fatigue resistance of a CoCrFeMnNi high-entropy alloy

Lam, T.-N.*; Chin, H.-H.*; Zhang, X.*; Feng, R.*; Wang, H.*; Chiang, C.-Y.*; Lee, S. Y.*; 川崎 卓郎; Harjo, S.; Liaw, P. K.*; et al.

Acta Materialia, 245, p.118585_1 - 118585_9, 2023/02

 被引用回数:0 パーセンタイル:0(Materials Science, Multidisciplinary)

The present study investigates the crystallographic-texture effects on the improved fatigue resistance in the CoCrFeMnNi high-entropy alloys (HEAs) with the full-size geometry of the ASTM Standards E647-99. We exploited X-ray nano-diffraction mapping to characterize the crystal-deformation levels ahead of the crack tip after stress unloading under both constant- and tensile overloaded-fatigue conditions. The crack-tip blunting-induced much higher deformation level was concentrated surrounding the crack-tip which delays the fatigue-crack growth immediately after a tensile overload. The predominant deformation texture orientation in the Paris regime was investigated, using electron backscatter diffraction and orientation distribution function analyses. The twinning formation-driven shear deformation gave rise to the development of the Goss-type texture within the plastic deformation regime under a tensile-overloaded-fatigue condition, which was attributed to enhance the crack deflection and thus the tensile induced crack-growth-retardation period in the CoCrFeMnNi HEA.


Investigation of hydrogen superoxide adsorption during ORR on Pt/C catalyst in acidic solution for PEFC by ${it in-situ}$ high energy resolution XAFS

山本 直生*; 松村 大樹; 萩原 悠人*; 田中 啓偉*; 長谷川 優太*; 石井 賢司*; 田中 裕久*

Journal of Power Sources, 557, p.232508_1 - 232508_10, 2023/02

Oxygen Reduction Reaction (ORR) is one of the key electrochemical reactions, especially in Polymer Electrolyte Fuel Cells (PEFCs). In this work, the reaction pathway and intermediate species such as molecular-type oxygen during ORR were discussed. High energy resolution X-ray absorption fine structure spectra at the Pt L$$_{3}$$-edge were obtained to observe the electronic structure of Pt catalyst. Carbon-supported Pt nanoparticles as powder catalysts were used for measurement as more realistic conditions, and the species adsorbed on the Pt nanoparticles were analyzed while controlling under the potentials in acidic electrolyte solution with N$$_{2}$$ or O$$_{2}$$ gas bubbling. Molecular-type oxygen adsorption species is observed only in the O$$_{2}$$-bubbled electrolyte solution. This intermediate adsorption species is assigned to a hydrogen superoxide.


Incoherent neutron scattering and Terahertz time-domain spectroscopy on protein and hydration water

中川 洋; 山本 直樹*

Life (Internet), 13(2), p.318_1 - 318_15, 2023/02




津田 泰孝

日本海新聞, P. 7, 2023/02

我々が普段使っているスマートフォンやPCがどのように動いているかご存じだろうか。それらの中で行われる高度な電子制御の鍵を握るのは、半導体と呼ばれる物質である。半導体とは、条件により電気を通す性質と通さない性質の両方を示す物質であり、特に代表的な半導体であるシリコンはあらゆる電化製品に利用されている。電子機器の制御をおこなう集積回路は、シリコンを酸素と反応させ、酸化膜を表面に形成するというプロセスを経て作られる。高性能な回路を構築するためには、この酸化膜をできるだけ薄く作ることが必要であり、近年その薄さはおよそ1ナノメートル(十億分の一メートル)にまで達している。これは物質を形作る原子の数で言いかえると、わずか数個分という薄さである。ここにほんの少しでも原子の抜け(欠陥)が存在すると消費電力の増加や誤作動といった問題が起こる。欠陥の少ない良質な酸化膜を作成するためには、反応を理解し、精密に制御することが必須である。シリコンと酸素との反応メカニズムは、未だ全貌が理解されているとはいえず、半導体産業の最先端では日々研究が進められている。しかし、反応式にしてしまえばSi+O$$_{2}$$ $$rightarrow$$ SiO$$_{2}$$という中学、高校で習うような簡単なものである。半導体に限らず、最先端の現場で活用される知識は、必ず学校で習う基礎と地続きである。子どもたちが学校でよく学び、将来活躍してくれることを期待している。


Spin gap in the weakly interacting quantum spin chain antiferromagnet KCuPO$$_{4}$$$$cdot$$H$$_{2}$$O

藤原 理賀; 萩原 雅人; 森田 克洋*; 村井 直樹; 幸田 章宏*; 岡部 博孝*; 満田 節生*

Physical Review B, 107(5), p.054435_1 - 054435_8, 2023/02

$$S$$ = 1/2ハイゼンベルグ直線鎖反強磁性体は、最も単純なスピンモデルであるが、様々な量子多体現象のプラットフォームを提供する。この論文では、準一次元反強磁性体KCuPO$$_{4}$$$$cdot$$H$$_{2}$$Oの磁性を報告した。$$T_{rm{N}}$$ = 11.7(1) Kにおいて、格子整合な長距離反強磁性秩序が形成され、その磁気モーメントの大きさは0.31(1) $$mu_{rm{B}}$$である事がわかった。また鎖内相互作用$$J$$と鎖間相互作用$$|J'|$$の大きさはそれぞれ172Kと4.25(4) Kと見積もられ、$$|J'|$$/$$J$$の比は0.0247(3)である。中性子非弾性散乱実験により、$$T_{rm{N}}$$より高温では、一次元ハイゼンベルグ量子スピン鎖の特徴である連続体励起スペクトルが観測され、$$T_{rm{N}}$$より低温では、分散励起にスピンギャップが観測された。これらの結果は、弱く結合した$$S$$ = 1/2ハイゼンベルグスピン鎖系で観測される性質と一致する。


In-operando measurement of internal temperature and stress in lithium-ion batteries

平野 辰巳*; 前田 壮宏*; 村田 哲之*; 山木 孝弘*; 松原 英一郎*; 菖蒲 敬久; 城 鮎美*; 安田 良*; 高松 大郊*

SPring-8/SACLA利用研究成果集(インターネット), 11(1), p.49 - 57, 2023/02

The temperature rise due to high current/power operations and stress caused by the expansion or contraction of electrodes by lithium (de)-intercalation is known to be a degradation factor in lithium-ion batteries (LIBs). Therefore, in this study, a new technique is proposed to simultaneously measure the internal temperature and stress in the 18650-type LIB during its operation. The operando measurement involved retaining a constant gage volume using rotating spiral slits, obtaining X-ray diffraction images using a highly sensitive two-dimensional detector, and employing the sin$$^{2}$$ $$psi$$ method to separate the stress and change in temperature. During the charging process, at the 1C current rate, the anode expansion, owing to the lithium intercalation, induced the radial compressive stress in the Cu anode collector. The radial stress changes of the Cu anode collector were -31 MPa (compression) and 44 MPa (tensile) during the 1C charge and discharge processes, respectively. Moreover, the internal temperature, which was higher than the surface temperature, was calculated by considering the radial stress change during the battery operation. During the 4C cycle, the surface and internal temperatures rose by 26 degree and 42 degree, respectively. The results indicate that the internal temperature and stress in the 18650-LIB were successfully measured during battery operation.


Evidence supporting reversible martensitic transformation under cyclic loading on Fe-Mn-Si-Al alloys using ${it in situ}$ neutron diffraction

澤口 孝宏*; 友田 陽*; 吉中 奎貴*; Harjo, S.

Acta Materialia, 242, p.118494_1 - 118494_14, 2023/01

 被引用回数:0 パーセンタイル:0.04(Materials Science, Multidisciplinary)

Fe-Mn-Si-based alloys, show superior resistance to plastic fatigue compared to the conventional steels, which is ascribed to the reversible back-and-forth movement of Shockley partial dislocations associated with a reversible martensitic transformation between the face-centered cubic $$gamma$$-austenite and hexagonal close-packed $$epsilon$$-martensite. The purpose of this study was to gather evidence of the reversible martensitic transformation using in situ neutron diffraction under cyclic loading. Three Fe-30Mn-Si-Al alloys with different Gibbs free energy differences at 298 K were studied to unravel the effect of phase stability on the degree of reversibility.


Electron storage performance of hybrid materials comprising polyoxometalates and carbon nanohorns as cathode-active materials

若松 勝洋*; 関原 輝昇*; 山口 慶彦*; 松島 諒*; 松村 大樹; Kuila, T.*; 吉川 浩史*

Batteries & Supercaps (Internet), 6(1), p.e202200385_1 - e202200385_8, 2023/01

 被引用回数:0 パーセンタイル:0.01(Electrochemistry)

Nanohybrid materials comprising polyoxometalates (POMs) and nanocarbons have attracted considerable attention as electrode-active materials for rechargeable lithium-ion batteries (LIBs). These materials exhibit multi-electron redox reactions, resulting in an improved battery capacity. This study focuses on carbon nanohorns (CNHs) as a nanocarbon material and evaluates the battery performance using POM/CNH hybrids as cathode-active materials. X-ray absorption fine structural analysis was performed to investigate the reaction mechanism of these hybrids. POM/oxidized CNH (CNHox) hybrid materials maintain high capacities at high current densities as the high surface area availability of CNHox leads to high electrical double-layer capacitances. These findings show an improved performance of the as-developed material when compared with those reported in previous papers and can contribute toward an improved design of cathode-active materials for high-performance supercapacitors.


Soft, environmentally degradable microfluidic devices for measurement of sweat rate and total sweat loss and for colorimetric analysis of sweat biomarkers

Liu, S.*; Yang, D. S.*; Wang, S.*; Luan, H.*; 関根 由莉奈; Model, J. B.*; Aranyosi, A. J.*; Ghaffari, R.*; Rogers, J. A.*

EcoMat (Internet), 5(1), p.e12270_1 - e12270_18, 2023/01

 被引用回数:2 パーセンタイル:75.4(Chemistry, Physical)

発汗量やバイオマーカーの非侵襲的でin situモニタリング技術は、人間の生理学的状態,健康、およびパフォーマンスに関するリアルタイムの洞察を取得するために重要である。最近、様々なウェアラブル型のマイクロ流体システムが開発されているが、ほとんどは使い捨てとして設計されおり、廃棄物問題への懸念がある。本研究では、発汗量の測定、バイオマーカーの比色分析など、あらゆる機能を備えた生分解性マイクロ流体システムを通じて、廃棄物問題を解決する材料と成形技術を確立した。本技術で利用する材料は、自然の土壌環境または産業用堆肥施設での微生物の酵素作用によって完全に分解した。構成材料、製造手順、組み立てプロセス、および完成したデバイスの詳細な特性評価により、従来のデバイスに匹敵する、またはそれよりも優れた性能パラメータが明らかになった。実際の利用試験により、これらのデバイスが身体活動および熱曝露中の発汗速度、発汗量、pH、および塩化物濃度の正確な測定値を取得可能であることが明らかとなった。


Fatigue crack non-propagation behavior of a gradient steel structure from induction hardened railway axles

Zhang, H.*; Wu, S. C.*; Ao, N.*; Zhang, J. W.*; Li, H.*; Zhou, L.*; 徐 平光; Su, Y. H.

International Journal of Fatigue, 166, p.107296_1 - 107296_11, 2023/01

 被引用回数:0 パーセンタイル:0.03(Engineering, Mechanical)

Abnormal damages in railway axles can lead to a significant hazard to running safety and reliability. To this end, a surface treatment was selected to effectively inhibit fatigue crack initiation and growth. In this study, a single edge notch bending fatigue test campaign with artificial notches was conducted to elucidate the fatigue crack non-propagation behavior in railway S38C axles subjected to an induction hardening process. The fatigue cracking behavior in the gradient structure was revealed by optical microscopy, electron backscatter diffraction, and fractography. The microhardness distribution was measured using a Vickers tester. The obtained results show that the microhardness of the strengthening layer is nearly triple that of the matrix. Owing to the gradient microstructures and hardness, as well as compressive residual stress, the fatigue long crack propagates faster once it passes through the hardened zone (approximately 2.0 mm in the radial depth). Thereafter, local retarding (including deflection, branching, and blunting) of the long crack occurs because of the relatively coarse ferrite and pearlite in the transition region and matrix. Totally, this fatigue cracking resistance is reasonably believed to be due to the gradient microstructure and residual stress. These findings help to tailor a suitable detection strategy for maximum defects or cracks in railway axles.

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