436 research outputs found

    Mechano-Chemical Polishing of Alloy 600 for Accelerated Crack Initiation in Simulated PWR Primary Water Environment and Three-Dimensional Crystallographic Characterization

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    In this study, we propose a simple approach to accelerate crack initiation in intergranular stress corrosion cracking (IGSCC) of Alloy 600 in a simulated pressurized water reactor (PWR) primary water environment. In addition, we perform three-dimensional crystallographic characterization of the crack initiation by electron backscatter diffraction (EBSD). Initiation of IGSCC of the alloy in the PWR primary environment was realized for a flat tensile specimen in a considerably short time through a slow strain rate test (SSRT). The accelerated initiation was attributed to the asperity of the alloy surface induced by mechano-chemical polishing with colloidal silica suspension before the SSRT was conducted. Following the SSRT, the specimen surfaces were covered with thick oxide films, which prevented EBSD measurements. The sputtering of thick oxide films enabled us to characterize cracks with EBSD, thus yielding important information on IGSCC. Finally, an approach for three-dimensional characterization of crack initiation is discussed

    High-Gain Power Recycling of a Fabry Perot Michelson Interferometer for a Gravitational-Wave Antenna

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    Power recycling was implemented on a fully suspended prototype interferometer with arm lengths of 20 m. A wave-front-sensing technique for alignment control of the suspended mirrors was also implemented, which allowed for several hours of stable operation. A power-recycling gain of greater than 12 was achieved, a significant increase over the highest gain in a suspended mirror Fabry Perot Michelson interferometer reported to date

    Ball milling pretreatment of oil palm biomass for enhancing enzymatic hydrolysis

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    Oil palm biomass, namely empty fruit bunch and frond fiber, were pretreated using a planetary ball mill. Particle sizes and crystallinity index values of the oil palm biomass were significantly reduced with extended ball mill processing time. The treatment efficiency was evaluated by the generation of glucose, xylose, and total sugar conversion yields from the pretreatment process compared to the amount of sugars from raw materials. Glucose and xylose contents were determined using high-performance liquid chromatography. An increasing trend in glucose and xylose yield as well as total sugar conversion yield was observed with decreasing particle size and crystallinity index. Oil palm frond fiber exhibited the best material yields using ball milling pretreatment with generated glucose, xylose, and total sugar conversion yields of 87.0, 81.6, and 85.4 %, respectively. In contrast, oil palm empty fruit bunch afforded glucose and xylose of 70.0 and 82.3 %, respectively. The results obtained in this study showed that ball mill-treated oil palm biomass is a suitable pretreatment method for high conversion of glucose and xylose

    尿中Nerve Growth Factorは、過活動膀胱症状を呈する患児の治療効果の予測因子になる

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    Objective: To assess urinary nerve growth factor (NGF) in children with overactive bladder (OAB) and to investigate the relationship between urinary NGF/creatinine (Cr) levels and OAB. Patients and methods: Thirty-five children (27 boys and 8 girls) with OAB and 11 children (6 boys and 5 girls) without OAB or any other urinary symptoms, who served as controls, were included in this study. Urinary NGF levels were measured using enzyme-linked immunosorbent assay. The total urinary NGF levels were adjusted with the concentration of urinary creatinine (NGF/Cr level). Refractory OAB was defined as little improvement in OAB symptoms despite at least 3 months of urotherapy and anticholinergic agent treatment. Urinary NGF/Cr was compared between the children with OAB and the controls. The relationship between urinary NGF/Cr and treatment outcomes was also evaluated. Results: Urinary NGF/Cr was significantly higher in the children with OAB when compared with those in the control group (0.65 ± 0.82 vs 0.11 ± 0.09, P = .0007). Improvement of OAB symptoms was observed in 26 out of 35 children (74%). The remaining 9 children showed refractory OAB symptoms (the refractory group). Urinary NGF/Cr was significantly higher in the refractory group than in the improved group (1.28 ± 1.34 vs 0.44 ± 0.39, P = .027). Conclusion: Urinary NGF/Cr was significantly higher in the children with OAB than in the controls, and was significantly higher in the refractory group than in the improved group. Urinary NGF/Cr could not only be a potential biomarker for children with OAB, but also a predictor of therapeutic efficacy in children with OAB.博士(医学)・乙第1454号・令和2年3月16日Copyright © 2017 Elsevier Inc. All rights reserved

    Stress corrosion cracking of copper in swollen bentonite simulating nuclear waste disposal environment

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    Stress corrosion cracking (SCC) of pure copper in bentonite clay was examined using a slow strain rate test (SSRT). Bentonite was swollen with pure water or aqueous solutions containing NH₃ of 5 and 10 mM. Thick corrosion films and particulate deposits were formed on the copper surface after the SSRT. Typical tarnish rupture-type SCC occurred on pure copper in swollen bentonite with and without NH₃. The crack propagation rate was enhanced by NH₃. It is confirmed that a thick oxide layer was formed on copper during plastic deformation, resulting in tarnish crack-type SCC. Many particulate deposits observed on the surface were formed due to the rapid dissolution of Cu²⁺ ions to form porous CuO at local deformed sites, regardless of the SCC occurrence

    交通行動と健康診断データ・心的傾向の関連分析 : 神奈川県大和市職員を対象として

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    本研究では,交通行動と健康状態,ならびにクルマの運転動機,交通手段への態度,五大性格特性,主観的幸福感等の心的傾向を計測する指標との関係性を把握することを目的に,神奈川県大和市職員を対象としたアンケート調査(n=479)を行った.このうち健康診断データの提供に同意した職員は180名であった.分析の結果,クルマ・バイク通勤者はメタボ該当者がそれ以外の通勤者の倍程度であった.心的傾向については,組織との関係が良好で地域のボランティアに参加しているほど,メタボや高BMIの傾向が示された.この理由としては,勤務先やボランティア等で飲食を伴う交流が盛んであった可能性が考えられる.メタボは危険因子が集積した状態であり,自覚症状が希薄であるため,健康指標として心的傾向と組み合わせた分析を行う際には留意が必要である
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