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O/HO vapor generator for contrast-variation neutron scatteringArima-Osonoi, Hiroshi*; Takata, Shinichi; Kasai, Satoshi*; Ouchi, Keiichi*; Morikawa, Toshiaki*; Miyata, Noboru*; Miyazaki, Tsukasa*; Aoki, Hiroyuki; Iwase, Hiroki*; Hiroi, Kosuke; et al.
Journal of Applied Crystallography, 56(6), p.1802 - 1812, 2023/12
Times Cited Count：0 Percentile：0.02(Chemistry, Multidisciplinary)
Sr in cattle bone and tooth samples by inductively coupled plasma mass spectrometryKoarai, Kazuma; Matsueda, Makoto; Aoki, Jo; Yanagisawa, Kayo*; Terashima, Motoki; Fujiwara, Kenso; Kino, Yasushi*; Oka, Toshitaka; Takahashi, Atsushi*; Suzuki, Toshihiko*; et al.
Journal of Analytical Atomic Spectrometry, 36(8), p.1678 - 1682, 2021/08
Times Cited Count：5 Percentile：55.72(Chemistry, Analytical)Rapid analysis of Sr in bone and tooth samples of cattle were achieved by an inductively coupled plasma mass spectrometry (ICP-MS) coupled with mass shift and solid phase extraction techniques. Limit of detection (LOD) in the ICP-MS measurement of 0.1 g samples was lower than that of the radioactivity measurement. Analytical time of the ICP-MS method was reduced from 20 days to 11 hours, compared with the radiometric method. Therefore, the ICP-MS method can be rapid and useful procedure of Sr in small bone and tooth samples derived from terrestrial animals.
Miyazaki, Tsukasa*; Miyata, Noboru*; Arima, Hiroshi*; Kira, Hiroshi*; Ouchi, Keiichi*; Kasai, Satoshi*; Tsumura, Yoshihiro*; Aoki, Hiroyuki
Langmuir, 37(32), p.9873 - 9882, 2021/08
Times Cited Count：5 Percentile：38.19(Chemistry, Multidisciplinary)Arima-Osonoi, Hiroshi*; Miyata, Noboru*; Yoshida, Tessei*; Kasai, Satoshi*; Ouchi, Keiichi*; Zhang, S.*; Miyazaki, Tsukasa*; Aoki, Hiroyuki
Review of Scientific Instruments, 91(10), p.104103_1 - 104103_7, 2020/10
Times Cited Count：9 Percentile：56.16(Instruments & Instrumentation)Kobayashi, Fuyumi; Sumiya, Masato; Kida, Takashi; Kokusen, Junya; Uchida, Shoji; Kaminaga, Jota; Oki, Keiichi; Fukaya, Hiroyuki; Sono, Hiroki
JAEA-Technology 2016-025, 42 Pages, 2016/11
JAEA-Technology-2016-025.pdf:17.88MB
A preliminary test on MOX fuel dissolution for the STACY critical experiments had been conducted in 2000 through 2003 at Nuclear Science Research Institute of JAEA. Accordingly, the uranyl / plutonium nitrate solution should be reconverted into oxide powder to store the fuel for a long period. For this storage, the moisture content in the oxide powder should be controlled from the viewpoint of criticality safety. The stabilization of uranium / plutonium solution was carried out under a precipitation process using ammonia or oxalic acid solution, and a calcination process using a sintering furnace. As a result of the stabilization operation, recovery rate was 95.6% for uranium and 95.0% for plutonium. Further, the recovered oxide powder was calcined again in nitrogen atmosphere and sealed immediately with a plastic bag to keep its moisture content low and to prevent from reabsorbing atmospheric moisture.
Ozawa, Mayumi; Fukaya, Hiroyuki; Sato, Makoto; Kamohara, Keiko*; Suyama, Kenya; Tonoike, Kotaro; Oki, Keiichi; Umeda, Miki
Proceedings of 53rd Annual Meeting of Hot Laboratories and Remote Handling Working Group (HOTLAB 2016) (Internet), 9 Pages, 2016/11
sp. AS-131 isolated from Antarctic OceanYonezawa, Yasushi*; Nagayama, Aiko*; Tokunaga, Hiroko*; Ishibashi, Matsujiro*; Arai, Shigeki; Kuroki, Ryota; Watanabe, Keiichi*; Arakawa, Tsutomu*; Tokunaga, Masao*
Protein Journal, 34(4), p.275 - 283, 2015/08
Times Cited Count：4 Percentile：11.12(Biochemistry & Molecular Biology)Nucleoside diphosphate kinase isolated from psychrophilic sp. AS-131 (ASNDK) was expressed in 
and purified to homogeneity. Comparing to mesophilic NDK isolated from 
, ASNDK exhibited highly elevated thermolability: (1) 
expression at 37
C as a denatured insoluble form, and (2) 30C lower optimum temperature of enzymatic activity. The subunit structure of ASNDK was suggested to be dimer, as in NDKs isolated from moderate halophiles.
Unno, Masayoshi*; Ishikawa, Kumiko*; Kusaka, Katsuhiro*; Tamada, Taro; Hagiwara, Yoshinori*; Sugishima, Masakazu*; Wada, Kei*; Yamada, Taro*; Tomoyori, Katsuaki; Hosoya, Takaaki*; et al.
Journal of the American Chemical Society, 137(16), p.5452 - 5460, 2015/04
Times Cited Count：28 Percentile：64.39(Chemistry, Multidisciplinary)Phycocyanobilin, a light-harvesting and photoreceptor pigment in higher plants, algae, and cyanobacteria, is synthesized from biliverdin IX
(BV) by phycocyanobilin:ferredoxin oxidoreductase (PcyA) via two steps of two-proton-coupled two-electron reduction. We determined the neutron structure of PcyA from cyanobacteria complexed with BV, revealing the exact location of the hydrogen atoms involved in catalysis. Notably, approximately half of the BV bound to PcyA was BVH
, a state in which all four pyrrole nitrogen atoms were protonated. The protonation states of BV complemented the protonation of adjacent Asp105. The "axial "water molecule that interacts with the neutral pyrrole nitrogen of the A-ring was identified. His88 N
was protonated to form a hydrogen bond with the lactam O atom of the BV A-ring. His88 and His74 were linked by hydrogen bonds via H
O. These results imply that Asp105, His88, and the axial water molecule contribute to proton transfer during PcyA catalysis.
Shibata, Masahiro; Sawada, Atsushi; Tachi, Yukio; Hayano, Akira; Makino, Hitoshi; Wakasugi, Keiichiro; Mitsui, Seiichiro; Oda, Chie; Kitamura, Akira; Osawa, Hideaki; et al.
JAEA-Research 2013-037, 455 Pages, 2013/12
JAEA-Research-2013-037.pdf:42.0MB
Following FY2011, JAEA and NUMO have conducted a collaborative research work which is designed to enhance the methodology of repository design and performance assessment in preliminary investigation stage. With regard to (1) study on rock suitability in terms of hydrology, the tree diagram of methodology of groundwater travel time has been extended for crystalline rock, in addition, tree diagram for sedimentary rock newly has been organized. With regard to (2) study on scenario development, the existing approach has been improved in terms of a practical task, and applied and tested for near field focusing on the buffer. In addition, the uncertainty of some important processes and its impact on safety functions are discussed though analysis. With regard to (3) study on setting radionuclide migration parameters, the approaches for parameter setting have been developed for sorption for rocks and solubility, and applied and tested through parameter setting exercises for key radionuclides.
Inagaki, Yaohiro*; Sakatani, Keiichi*; Yamamura, Yuki*; Mitsui, Seiichiro; Noshita, Kenji*; Miura, Yoshiyuki*; Kanehira, Norio*; Ochi, Eiji*; Mukunoki, Atsushi*; Chiba, Tamotsu*
Dai-7-Kai Saishori, Risaikuru Bukai Semina Tekisuto, p.136 - 137, 2011/01
Conventional static test methods are not appropriate to evaluate glass dissolution behavior at an arbitrarily-fixed condition due to compositional change of the solution with glass dissolution. In this study, we applied a newly-devised micro-channel flow-through test method to measurement of the initial dissolution rates of Japanese simulated waste glasses, JAEA-P0798 and JNFL-KMOC, at arbitrarily-fixed conditions and we evaluated temperature and pH dependence of glass dissolution. The results showed that the initial dissolution rate increased with temperature and had "V-shaped" pH dependence at each temperature.
Isaka, Koji; Terunuma, Noriaki; Ouchi, Satoshi; Oki, Keiichi; Suwa, Masayuki
Nihon Hozen Gakkai Dai-6-Kai Gakujutsu Koenkai Yoshishu, p.279 - 282, 2009/08
As the modified JRR-3 has been operated for 18 years, it is necessary to be maintained for keeping the safe and stable operation. The review of maintenance activity is constantly performed for the step-by-step update of facilities and the improvement of the maintenance method and so on. Our investigation of the maintenance activity about the instrumentation and control device of modified JRR-3 is presented.
Mizuki, Junichiro; Aoki, Katsutoshi; Koike, Masato; Yokoyama, Keiichi
Nihon Genshiryoku Gakkai-Shi ATOMO
, 51(2), p.88 - 93, 2009/02
The light is electro magnetic wave, and is a complementary probe to neutron, electron, and ion beams. In this article, the leading-edge of the technology of Laser and Synchrotron Radiation X-rays is present, and we hope to have an interest of these probes.
-ray emitting nuclides (Joint research)Ishimori, Kenichiro; Oki, Keiichi; Takaizumi, Hirohide; Kameo, Yutaka; Oki, Yoshiyuki*; Nakashima, Mikio
JAEA-Technology 2007-065, 20 Pages, 2008/01
JAEA-Technology-2007-065.pdf:1.4MB
In order to prepare a reference material which is used for radiochemical analysis of solidified products made from non-metallic miscellaneous low level radioactive solid wastes by melting in Nuclear Science Research Institute, Japan Atomic Energy Agency, the preparation method of the reference material was investigated. Under the optimum melting conditions obtained in this report, the reference material containing 
Np, 
Am and 
Cm as -ray emitting nuclides was successfully prepared. From radiochemical analysis of the reference material, the radioactive concentration of respective nuclides was determined to be 0.188
0.001 Bq/g for Np, 0.3680.004 Bq/g for Am, 0.4020.010 Bq/g for Cm.
Sadakane, Kozo*; Arai, Akira*; Aoki, Wako*; Arimoto, Nobuo*; Hidai, Masahide*; Onishi, Takashi*; Tajitsu, Akito*; Beers, T. C.*; Iwamoto, Nobuyuki; Tominaga, Nozomu*; et al.
Publications of the Astronomical Society of Japan, 58(3), p.595 - 604, 2006/06
Times Cited Count：11 Percentile：31.92(Astronomy & Astrophysics)We report detailed spectroscopic studies performed for the secondary star in the black hole binary (micro-quasar) V4641 Sgr in order to examine its surface chemical composition and to see if its surface shows any signature of pollution by ejecta from a supernova explosion. We obtain abundances of 10 elements and find definite over-abundances of N (by 0.8 dex or more) and Na (by 0.8 dex) in V4641 Sgr. From line-by-line comparisons of eight other elements (C, O, Mg, Al, Si, Ti, Cr, Fe) between V4641 Sgr and the two normal late B-type stars, which have been reported to have solar abundances. An evolutionary model of a massive close binary system has been constructed to explain the abundances observed in V4641 Sgr. The model suggests that the BH forming supernova in this system was a dark one.
CIshimori, Kenichiro; Oki, Keiichi; Kameo, Yutaka; Takaizumi, Hirohide; Nakashima, Mikio; Oki, Yoshiyuki*; Isogai, Keisuke*
no journal, ,
no abstracts in English
Mn
O
Kimura, Hiroyuki*; Wakimoto, Shuichi; Kamada, Yoichi*; Noda, Yukio*; Kakurai, Kazuhisa; Kaneko, Koji; Metoki, Naoto; Kon, Keiichiro*
no journal, ,
MnO(
rare earth, Bi, Y) systen achieves a multi-ferroic state where magnetic and ferroelectric orders coexist. We have performed neutron diffraction under magnetic field to study the correlation between field-induced magnetism and ferroelectricity. T-H phase diagram of the magnetic and electric states for two samples, HoMnO
and ErMnO, shows perfect agreement between the commensurate-incommensurate magnetic phase boundary and the ferroelectric transition, evincing that the commensurate magnetic state is essential for the ferroelectric state in this system.
Tachibana, Mitsuo; Satoyama, Tomonori; Oki, Keiichi; Naito, Akira; Takaizumi, Hirohide; Yoshimori, Michiro; Okoshi, Minoru; Hoshi, Akiko
no journal, ,
no abstracts in English
Satoyama, Tomonori; Oki, Keiichi; Naito, Akira; Yoshimori, Michiro; Okoshi, Minoru; Kogure, Hiroto; Tsutsumi, Masahiro; Inanobe, Hiroshi
no journal, ,
no abstracts in English
Yoshimori, Michiro; Satoyama, Tomonori; Oki, Keiichi; Naito, Akira; Okoshi, Minoru; Hoshi, Akiko
no journal, ,
no abstracts in English
Oki, Keiichi; Murayama, Yoji; Sasajima, Fumio; Izumo, Hironobu; Inoue, Takeshi; Unesaki, Hironobu*
no journal, ,
no abstracts in English
