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Nakae, Masanori*; Matsuyama, Tsugufumi*; Murakami, Masashi; Yoshida, Yukihiko; Machida, Masahiko; Tsuji, Koichi*
Advances in X-Ray Chemical Analysis, Japan, 54, p.89 - 99, 2023/03
Fundamental research on X-ray absorption imaging for elemental identification was studied. A secondary target was applied to obtain X-ray absorption images above and below the X-ray absorption edge of the target element. X-rays from an X-ray tube were irradiated to the secondary target, where the characteristic X-rays were emitted that were irradiated to the sample. X-ray absorption images were acquired with an exposure time of a few seconds with an X-ray camera. In this technique, it is difficult to change the energy of X-rays as we want, however we can apply this technique for imaging the specific element. Metal foil sample composed of Al, Cu, and Ni was analyzed. To obtain an X-ray elemental image of Ni, two X-ray absorption images were taken using the X-rays above and below the Ni K-edge. X-rays of Cu K
and Zn K were prepared by using Cu and Zn plates as the secondary target. Finally, the Ni elemental image was obtained by subtracting two images. Furthermore, the X-ray camera had a function of setting critical energies for imaging, thus it was demonstrated that an X-ray elemental image of Ni was obtained using a single secondary target without changing the secondary target.
Matsuyama, Tsugufumi*; Nakae, Masanori*; Murakami, Masashi; Yoshida, Yukihiko; Machida, Masahiko; Tsuji, Koichi*
Spectrochimica Acta, Part B, 199, p.106593_1 - 106593_6, 2023/01
Times Cited Count：2 Percentile：45.92(Spectroscopy)Ishikawa, Ryoya*; Suzuki, Masatoshi*; Kino, Yasushi*; Endo, Satoru*; Nakajima, Hiroo*; Oka, Toshitaka; Takahashi, Atsushi*; Shimizu, Yoshinaka*; Suzuki, Toshihiko*; Shinoda, Hisashi*; et al.
KEK Proceedings 2022-2, p.61 - 66, 2022/11
The balance between oxidative stress and antioxidant activity, which is a defense mechanism against oxidative stress, was investigated in the liver and bladder of wild Japanese macaques captured in Fukushima Prefecture. No significant induction of oxidative stress by exposure to environmental radionuclides after the Fukushima nuclear accident was observed, suggesting that the stress defense mechanism of the organism is activated in some organs.
Fuchita, Tomoki*; Urata, Taisei*; Matsuyama, Tsugufumi*; Murakami, Masashi; Yoshida, Yukihiko; Ueda, Akihiko; Machida, Masahiko; Sasaki, Toshiki; Tsuji, Koichi*
Advances in X-Ray Chemical Analysis, Japan, 53, p.77 - 87, 2022/03
X-ray fluorescence (XRF) analysis is an analytical method to obtain elemental information by detecting fluorescence X-rays emitted from a sample irradiated with X-rays. It is possible to obtain two-dimensional elemental distribution images by scanning a sample with micro X-ray beam. In this study, we developed an XRF analytical instrument to rapidly obtain the elemental distributions for moving samples on a belt conveyor by applying the micro XRF technique. X-rays were widely irradiated to the belt conveyor. The elemental distributions were measured by scanning an X-ray detector, crossing above the belt conveyor. A collimator was attached to the top of the detector to limit the analyzing area. Both detection limit and spatial resolutions for moving directions of the detector and the belt conveyor were evaluated. Finally, it was demonstrated that the multi-elemental imaging was possible with the developed XRF instrument.
Sun, L.*; Inaba, Yohei*; Kanzaki, Norie; Bekal, M.*; Chida, Koichi*; Moritake, Takashi*
International Journal of Molecular Sciences (Internet), 21(3), p.812_1 - 812_12, 2020/01
Times Cited Count：7 Percentile：36.56(Biochemistry & Molecular Biology)Biodosimetry is a useful method to estimate the personal dose after unexpected ionizing radiation exposure. Studies have been reported that metabolites are useful markers for biodosimetry. However, these studies only focused on non-cellular biofluid (e.g., serum, plasma, urine, or saliva). Blood cell metabolites may reflect the health status or environmental stresses differently than metabolites of plasma. Here, we report changes in the metabolites of blood cells after X-ray irradiation of C57BL/6J mice. Blood cell metabolites were measured by capillary electrophoresis time-of-flight mass spectrometry. We found that 106 metabolites were changed significantly after irradiation. We identified that 2'-deoxycytidine, choline, and N6-acetyllysine as potentially useful discriminating markers of radiation exposure. These metabolites have not been reported previously. Furthermore, we established a prediction panel of the exposure dose using stepwise regression analysis. These findings suggest that blood cell metabolites may be useful biomarkers to estimate exposure doses during unexpected radiation incidents.
Ikushima, Kazuki*; Shibahara, Masakazu*; Kawajiri, Yoshitaka*; Okimi, Yui*; Uchida, Tomoki*; Akita, Koichi*; Suzuki, Hiroshi; Morooka, Satoshi
Nihon Senpaku Kaiyo Kogakkai Rombunshu, (30), p.123 - 130, 2019/12
In this research, the contour method was applied to measure the residual stress distribution of a bead-on-plate specimen. The measured residual stress distribution was compared with those measured by neutron diffraction method and calculated by thermal elastic plastic finite element analysis. As a result, it was found that the residual stress distribution obtained by these three methods are in good agreement. In addition, the equilibrium of reaction force on cut plane was considered in the contour method to measure residual stresses in asymmetric cutting which is assumed in the measurement of real structures. The proposed method was applied to the measurement of the residual stress in the multi-pass welded joint. The measured results indicated that the proposed method can measure the residual stress distribution in multi-pass welded joint in asymmetric test specimen.
Iwasaki, Yuma*; Takeuchi, Ichiro*; Stanev, V.*; Gilad Kusne, A.*; Ishida, Masahiko*; Kirihara, Akihiro*; Ihara, Kazuki*; Sawada, Ryoto*; Terashima, Koichi*; Someya, Hiroko*; et al.
Scientific Reports (Internet), 9, p.2751_1 - 2751_7, 2019/02
Times Cited Count：61 Percentile：92.99(Multidisciplinary Sciences)Wakai, Takashi; Machida, Hideo*; Arakawa, Manabu*; Kikuchi, Koichi*
Proceedings of ASME Symposium on Elevated Temperature Applications of Materials for Fossil, Nuclear, and Petrochemical Industries, 7 Pages, 2018/04
A simplified J-integral evaluation method applicable to unstable failure analysis in Leak Before Break (LBB) assessment of Sodium-cooled Fast Reactor (SFR) in Japan was proposed. Mod.9Cr-1Mo steel is supposed to be a candidate material for the coolant systems of SFR in Japan. This steel has relatively high yield strength and poor fracture toughness comparing to those of conventional austenitic stainless steels. In addition, SFR pipe has small thickness and large diameter. As a J-integral evaluation method for circumferential through-wall crack in a cylinder, EPRI has proposed a fully plastic solution method. However, the geometry of SFR pipe and material characteristics of Mod.9Cr-1Mo steel exceed the applicable range of EPRI's method. Therefore, a series of elastic, elasto-plastic and plastic finite element analyses (FEA) were performed for a pipe with a circumferential through-wall crack to propose a J-integral evaluation method applicable to such loading conditions. J-integrals obtained from the FEA were resolved into elastic, local plastic and fully plastic components. Each component was expressed as a function of analytical parameter, such as pipe geometries, crack size, material characteristics and so on. As a result, a simplified J-integral evaluation method was proposed. The method enables to conduct 2 parameter failure analysis using J-integral without any fracture mechanics knowledge.
Machida, Masahiko; Kato, Koichiro*; Shiga, Motoyuki
Journal of Chemical Physics, 148(10), p.102324_1 - 102324_11, 2018/03
Times Cited Count：19 Percentile：70.02(Chemistry, Physical)The isotopologs of liquid water, H
O, DO, and TO, are studied systematically by first principles PIMD simulations, in which the whole entity of the electrons and nuclei are treated quantum mechanically. The simulation results are in reasonable agreement with available experimental data on isotope effects, in particular, on the peak shift in the radial distributions of HO and DO and the shift in the evaporation energies. It is found that, due to differences in nuclear quantum effects, the H atoms in the OH bonds more easily access the dissociative region up to the hydrogen bond center than the D (T) atoms in the OD (OT) bonds. The accuracy and limitation in the use of the current density-functional-theory-based first principles PIMD simulations are also discussed. It is argued that the inclusion of the dispersion correction or relevant improvements in the density functionals are required for the quantitative estimation of isotope effects.
Kirihara, Akihiro*; Kondo, Koichi*; Ishida, Masahiko*; Ihara, Kazuki*; Iwasaki, Yuma*; Someya, Hiroko*; Matsuba, Asuka*; Uchida, Kenichi*; Saito, Eiji; Yamamoto, Naoharu*; et al.
Scientific Reports (Internet), 6, p.23114_1 - 23114_7, 2016/03
Times Cited Count：62 Percentile：90.69(Multidisciplinary Sciences)Heat-flow sensing is expected to be an important technological component of smart thermal management in the future. Conventionally, the thermoelectric (TE) conversion technique, which is based on the Seebeck effect, has been used to measure a heat flow by converting the flow into electric voltage. However, for ubiquitous heat-flow visualization, thin and flexible sensors with extremely low thermal resistance are highly desired. Recently, another type of TE effect, the longitudinal spin Seebeck effect (LSSE), has aroused great interest because the LSSE potentially offers favourable features for TE applications such as simple thin-film device structures. Here we demonstrate an LSSE-based flexible TE sheet that is especially suitable for a heat-flow sensing application. This TE sheet contained a Ni
Zn
Fe
O
film which was formed on a flexible plastic sheet using a spray-coating method known as ferrite plating. The experimental results suggest that the ferrite-plated film, which has a columnar crystal structure aligned perpendicular to the film plane, functions as a unique one-dimensional spin- current conductor suitable for bendable LSSE-based sensors. This newly developed thin TE sheet may be attached to differently shaped heat sources without obstructing an innate heat flux, paving the way to versatile heat-flow measurements and management.
Onuki, Yoshichika; Settai, Rikio*; Haga, Yoshinori; Machida, Yo*; Izawa, Koichi*; Honda, Fuminori*; Aoki, Dai*
Comptes Rendus Physique, 15(7), p.616 - 629, 2014/08
Times Cited Count：6 Percentile：44.89(Astronomy & Astrophysics)
probed by thermal transport tensorsIzawa, Koichi*; Machida, Yo*; Ito, Atsushi*; So, Yoshinao*; Ota, Katsuya*; Haga, Yoshinori; Yamamoto, Etsuji; Kimura, Noriaki*; Onuki, Yoshichika; Tsutsumi, Yasumasa*; et al.
Journal of the Physical Society of Japan, 83(6), p.061013_1 - 061013_8, 2014/06
Times Cited Count：22 Percentile：74.34(Physics, Multidisciplinary)
ions through micro- and nano-capillariesTsuchida, Hidetsugu*; Majima, Takuya*; Tomita, Shigeo*; Sasa, Kimikazu*; Narumi, Kazumasa; Saito, Yuichi; Chiba, Atsuya; Yamada, Keisuke; Hirata, Koichi*; Shibata, Hiromi*; et al.
Nuclear Instruments and Methods in Physics Research B, 315, p.336 - 340, 2013/11
Times Cited Count：3 Percentile：26.71(Instruments & Instrumentation)Iguchi, Masahide; Chida, Yutaka; Takano, Katsutoshi; Kawano, Katsumi; Saito, Toru; Nakajima, Hideo; Koizumi, Norikiyo; Minemura, Toshiyuki*; Ogata, Hiroshige*; Ogawa, Tsuyoshi*; et al.
IEEE Transactions on Applied Superconductivity, 22(3), p.4203305_1 - 4203305_5, 2012/06
Times Cited Count：9 Percentile：47.58(Engineering, Electrical & Electronic)Japan Atomic Energy Agency (JAEA) has responsibility to procure 19 structures for ITER toroidal field (TF) coils as in-kind components. JAEA plans to use materials specified in the material section of "Codes for Fusion Facilities; Rules on Superconducting Magnet Structure (2008)" issued by the Japan Society of Mechanical Engineers (JSME) in 2008. Large forged products were produced and their mechanical properties at 4K were evaluated. In addition, the following activities have been performed; (1) to optimize the design of each weld type identified in the manufacturing sequence, (2) to qualify typical welding procedure including repair, (3) to establish welding techniques other than narrow gap TIG welding with FMYJJ1, (4) to demonstrate the manufacturing procedures through manufacture of 1-m mockups and full-scale segments of TFC structure. This paper describes the results of material qualification and industrialization activities of manufacturing processes of ITER TFC structure.
Koizumi, Norikiyo; Matsui, Kunihiro; Hemmi, Tsutomu; Takano, Katsutoshi; Chida, Yutaka; Iguchi, Masahide; Nakajima, Hideo; Shimada, Mamoru*; Osemochi, Koichi*; Makino, Yoshinobu*; et al.
IEEE Transactions on Applied Superconductivity, 22(3), p.4200404_1 - 4200404_4, 2012/06
Times Cited Count：9 Percentile：47.58(Engineering, Electrical & Electronic)JAEA started sub- and full-scale trials to qualify and optimize manufacturing procedure of ITER TF coil from March, 2009. As major outcome of these trials, automatic winding system with accuracy in conductor length measurement of 0.01% has been established and the elongation of the conductor length due to heat treatment was measured to be 0.06%. To confirm validity of these outcomes, the authors carried out winding of a one-third scale dummy double pancake (DP), followed by its insulation and impregnation trial, and, in addition, heat treatment of one-third scale DP with real a TF conductor. The details about these trials are described in the other paper. The authors also performed trial manufacture of full scale RP and CPs for dummy double pancake, which will be made in near future. The full scale RP is manufactured by machining 10 segments in parallel to shorten machining duration and joining each segment by welding. In our trial manufacture of the full scale RP, hot-rolled SS316LN plates are machined to a final dimension, namely without additional material, and these segments are laser-welded. From these trials, manufacturing procedure of a thick hot-roll SS316LN plate is qualified and machining procedure is established, while more optimization may be necessary to achieve the required schedule and cost.
Machida, Akihiko; Honda, Mitsunori*; Hattori, Takanori; Sano, Asami; Watanuki, Tetsu; Katayama, Yoshinori; Aoki, Katsutoshi; Komatsu, Kazuki*; Arima, Hiroshi*; Oshita, Hidetoshi*; et al.
Physical Review Letters, 108(20), p.205501_1 - 205501_5, 2012/05
Times Cited Count：17 Percentile：67.41(Physics, Multidisciplinary)Hydrogen atoms absorbed in a metal occupy the interstitial sites of the metal lattice. In an fcc metal lattice, each metal atom has two tetrahedral (T) and one octahedral (O) sites that can accommodate hydrogen. Rare-earth metal La forms T-site occupied LaH
and fully occupied LaH. O-site occupied or NaCl-type monohydride has yet to be reported for rare-earth metals. Previous X-ray diffraction measurements revealed the pressure-induced decomposition of an fcc-LaH
into H-rich and H-poor phases around 11 GPa. The present neutron diffraction measurements on LaD confirm the formation of NaCl-type LaD as a counterpart of the D-rich LaD
by disproportionation. First-principle calculations demonstrate that the NaCl-type LaH is stabilized at high pressures. Finding the NaCl-type LaH will pave the way for investigations on the site-dependent nature of hydrogen-metal interactions.
Machida, Yo*; Ito, Atsushi*; So, Yoshinao*; Izawa, Koichi*; Haga, Yoshinori; Yamamoto, Etsuji; Kimura, Noriaki*; Onuki, Yoshichika; Tsutsumi, Yasumasa*; Machida, Kazushige*
Physical Review Letters, 108(15), p.157002_1 - 157002_5, 2012/04
Times Cited Count：68 Percentile：90.45(Physics, Multidisciplinary)Nagamoto, Yoshifumi*; Osemochi, Koichi*; Shimada, Mamoru*; Senda, Ikuo*; Koizumi, Norikiyo; Chida, Yutaka; Iguchi, Masahide; Nakajima, Hideo
Teion Kogaku, 47(3), p.200 - 205, 2012/03
Based on the results of the sub- and full-scale trials, the TF coil and TF coil structure manufacturing procedures were considered. Radial plate (RP) will be manufactured by assembling 10 sets of segments with Laser Beam Welding. Cover plates (CPs) will be manufactured by 3 different methods, depending on their geometry. For Winding pack (WP), winding system to enable to measurement of the conductor length with the accuracy of 0.01% for serial production was designed. Assembling procedure and groove types of narrow gap TIG welding for coil structures were determined. Hereafter, technical improvements will be considered in order to aim for further optimization of manufacturing.
Chida, Yutaka; Iguchi, Masahide; Takano, Katsutoshi; Nakajima, Hideo; Osemochi, Koichi*; Niimi, Kenichiro*; Tokai, Daisuke*; Gallix, R.*
Fusion Engineering and Design, 86(12), p.2900 - 2903, 2011/12
Times Cited Count：10 Percentile：60.88(Nuclear Science & Technology)TF coil structures, which support large electromagnetic force generated in TF coils under the cryogenic temperature (about 4K), are the mega welding structures composed of coil case and support structures made of high strength and high toughness stainless steel. JAEA started the study on welding trials for heavy thickness materials since 2008 and is planning of full scale mock-up model fabrication for main sub-components (1 set of inboard side and 1set of outboard side) in 2010 in order to investigate the technical issues for manufacturing of TF coil structures. This paper introduces the results on welding trials and status of full scale mock-up model fabrication to confirm the validity of welding technology and manufacturing design before fabricating actual products.
Chida, Yutaka; Iguchi, Masahide; Nakajima, Hideo; Osemochi, Koichi*; Niimi, Kenichiro*; Tokai, Daisuke*
Proceedings of 2011 ASME Pressure Vessels and Piping Conference (PVP 2011) (CD-ROM), 5 Pages, 2011/07
The Japan Atomic Energy Agency (JAEA), acting as the Japan Domestic Energy Agency (JADA) in the ITER project, is responsible for the procurement of structures for 19 TF coils (including one spare). TF coil structures, which support large electromagnetic force generated in TF coils under the cryogenic temperature (about 4K), are the mega welding structures composed of coil case and support structures made of high strength and high toughness stainless steel. JAEA started the study on welding trials for heavy thickness materials since 2008 and is demonstrating of full scale mock-up model fabrication for main sub-components in 2010 in order to investigate the technical issues for manufacturing of TF coil structures. This paper introduces the results on welding trials and status of full scale mock-up model fabrication to confirm the validity of welding technology and manufacturing design before fabricating actual products. Enough weld joint performance was obtained with the base metal of JJ1 (high strength and high toughness stainless steel developed in Japan) and SS316LN, and also their combination using JJ1 filler wire (developed in Japan) by narrow gap GTAW process. Welding deformation such as angular distortion between outer plate and side plate of U-shape segment could be controlled and minimized by using effective restraint jig and no defects was observed in the welds by radiographic testing (RT) in trial manufacturing of 1m length. Validity of welding technology and manufacturing design such as fabrication sequence, welding procedure specification (WPS), quality control plan is confirmed during full scale mock-up model fabrication.
