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Kato, Masaru*; Muto, Marika*; Matsubara, Naohiro*; Uemura, Yohei*; Wakisaka, Yuki*; Yoneuchi, Tsubasa*; Matsumura, Daiju; Ishibara, Tomoko*; Tokushima, Takashi*; Noro, Shinichiro*; et al.
ACS Applied Energy Materials (Internet), 1(5), p.2358 - 2364, 2018/05
Times Cited Count：12 Percentile：43.4(Chemistry, Physical)Noda, Yohei*; Koizumi, Satoshi*; Masui, Tomomi*; Mashita, Ryo*; Kishimoto, Hiromichi*; Yamaguchi, Daisuke; Kumada, Takayuki; Takata, Shinichi; Oishi, Kazuki*; Suzuki, Junichi*
Journal of Applied Crystallography, 49(6), p.2036 - 2045, 2016/12
Times Cited Count：19 Percentile：78.58(Chemistry, Multidisciplinary)
-edge soft X-ray natural circular dichroism of histidine thin filmIzumi, Yudai; Tanaka, Masahito*; Tanigawa, Yoshiaki*; Tanabe, Maiko*; Momoki, Yohei*; Iwai, Miki*; Takenaka, Shun*; Ishiyama, Kimihiro*; Kuroki, Misa*; Muro, Takayuki*; et al.
Journal of Physics; Conference Series, 502(1), p.012038_1 - 012038_4, 2014/04
Times Cited Count：2 Percentile：72.7(Materials Science, Multidisciplinary)
spp. under the ISS environmental conditions for performing exposure experiments of microbes in the Tanpopo missionKawaguchi, Yuko*; Yang, Y.*; Kawashiri, Narutoshi*; Shiraishi, Keisuke*; Takasu, Masako*; Narumi, Issey*; Sato, Katsuya; Hashimoto, Hirofumi*; Nakagawa, Kazumichi*; Tanigawa, Yoshiaki*; et al.
Origins of Life and Evolution of Biospheres, 43(4-5), p.411 - 428, 2013/10
Times Cited Count：41 Percentile：80.34(Biology)Kumada, Takayuki; Noda, Yohei; Ishikawa, Norito
Journal of Magnetic Resonance, 218, p.59 - 65, 2012/05
Times Cited Count：6 Percentile：34.81(Biochemical Research Methods)We compared dynamic nuclear polarization (DNP) behavior of electron-beam irradiated polyethylene (e-PE) with that of TEMPO-doped polystyrene (T-PS). Although both T-PS had a sharp maximum in nuclear polarization at the concentration of free radicals of 2
10
spins cm
, that of e-PE depend much less. Growth and decay rates of polarization of e-PE linearly increased with increasing the radical concentration, whereas those rates of T-PS increased with square of radical concentration. We concluded that, not a pair of unspecified radicals accidentally located nearby, but a pair of alkyl radicals produced by the dissociation of C-H bond by an electron irradiation and the subsequent hydrogen abstraction reaction play an important role on DNP of e-PE.
Miwa, Shuhei; Ishi, Yohei*; Osaka, Masahiko
Journal of Nuclear Materials, 389(3), p.402 - 406, 2009/06
Times Cited Count：12 Percentile：62.36(Materials Science, Multidisciplinary)The effect of oxygen potential on the sintering behavior of MgO based heterogeneous fuels containing (Pu,Am)O was experimentally investigated. Sintering tests in various atmospheres, i.e. air, moisturized 4%H
-Ar, and 4%H-Ar atmosphere, were carried out. The sintering behavior was found to be significantly affected by the oxygen potential in the sintering atmosphere. The sintered density decreased with decreasing oxygen potential. The (Pu,Am)O phase sintered in a reductive atmosphere had hypostoichiometry. The aggregates of the (Pu,Am)O phase sintered in the reductive atmosphere grew, in comparison with those in the oxidizing one. The sintering mechanism was discussed in terms of the difference in sintering behavior of (Pu,Am)O and MgO.
Sakanaka, Shogo*; Ago, Tomonori*; Enomoto, Atsushi*; Fukuda, Shigeki*; Furukawa, Kazuro*; Furuya, Takaaki*; Haga, Kaiichi*; Harada, Kentaro*; Hiramatsu, Shigenori*; Honda, Toru*; et al.
Proceedings of 11th European Particle Accelerator Conference (EPAC '08) (CD-ROM), p.205 - 207, 2008/06
Future synchrotron light sources based on the energy-recovery linacs (ERLs) are expected to be capable of producing super-brilliant and/or ultra-short pulses of synchrotron radiation. Our Japanese collaboration team is making efforts for realizing an ERL-based hard X-ray source. We report recent progress in our R&D efforts.
Osaka, Masahiko; Miwa, Shuhei; Tanaka, Kosuke; Sato, Isamu; Hirosawa, Takashi; Obayashi, Hiroshi; Mondo, Kenji; Akutsu, Yoko; Ishi, Yohei; Koyama, Shinichi; et al.
WIT Transactions on Ecology and the Environment, Vol.105, p.357 - 366, 2007/06
no abstracts in English
Sato, Isamu; Seki, Takayuki*; Ishi, Yohei; Mondo, Kenji; Yoshimochi, Hiroshi; Tanaka, Kenya
JAEA-Research 2007-013, 63 Pages, 2007/03
JAEA-Research-2007-013.pdf:4.89MB
In air atmosphere, the weight of Am-MOX fuel relatively rapidly increased, which change rate strongly depended on the initial O/M ratio. The lower initial O/M ratio is, the higher the rate is. However, for the other MOX fuel containing little Am, the equivalent behavior have been observed, which indicated that not only Am but also the property of law material powder affected the behavior. The X-ray diffraction pattern change as time goes by was observed, which was a evidence that the O/M ratio change might arise from crystallographic one. The rate of O/M ratio change is a function of water vapor pressure in the atmosphere. If the water vapor pressure would is set to be quite low (ex. 
1ppm), the O/M ratio change could effectively been avoided. On a model basis of Am(III) and U(V) existence, we could explain the O/M ratio dependence of the lattice parameter of Am-MOX fuel near O/M ratio, 2.00 better.
by an in-cell remote processYoshimochi, Hiroshi; Ishi, Yohei; Seki, Takayuki*; Mondo, Kenji; Sekine, Shinichi*; Koyama, Shinichi
Saikuru Kiko Giho, (28), p.9 - 20, 2005/09
An in-cell remote fabrication technique has been developed for MOX fuel pellets containing 3 and 5% americium (Am-MOX) at the Alpha-gamma Facility (AGF) in O-arai Engineering Center. A series of fuel pellet and the pin fabrication apparatuses were systematically installed in hot cell to make fabrication flow easier. After cold run and some modifications, they were remotely controlled from a panel in the operation room outside the hot cell as much as possible. From a preliminary UO2 pellet test and consequently plutonium pellet fabrication run, actual range of ball milling time, pressing and sintering condition were focused for Am-MOX pellet fabrication. As the next step, moisturized atmosphere was found out to remove the heterogeneity structure of 5% Am-MOX pellet. Finally, we established an optimized fabrication condition of 5% Am-MOX pellet sintered at 1700
C for 3h in an atmosphere of 5% H2-95% Ar with total moisture of 2000 ppm. Moreover it is important that the atmosphere has to be changed to dry gas at 800C during cool down.
Osaka, Masahiko; Miwa, Shuhei; Mondo, Kenji; Ozaki, Yoko; Ishi, Yohei; Yoshimochi, Hiroshi; Seki, Takayuki*; Sekine, Shinichi*; Ishida, Takashi*; Tanaka, Kenya
JNC TN9400 2005-002, 40 Pages, 2005/03
JNC-TN9400-2005-002.pdf:2.43MB
An experimental investigation for the phase relation of (U,Pu,Am)O was performed with XRD, ceramography and DTA. Although lattice parameter tended to increase with increases of Am content and O/M ratio, its slope differed from that of (U,Pu)O. A drastic structural change was observed around O/M=1.98. Besides, many DTA peaks, which could never be seen in the case of (U,Pu)O, were observed above O/M=1.98.These results were interpreted with a hypothesis that all Am were trivalent and equivalent amount of U became pentavalent. The dependence of lattice parameter on Am content could be expressed well by using a model with ionic radii of each element. Also the structural change around O/M=1.98 could be explained as caused by valence states of each element. It was concluded from these interpretation that all Am in (U,Pu,Am)O were likely to exist as trivalent state.
Konomura, Mamoru; Ogawa, Takashi; Okano, Yasushi; Yamaguchi, Hiroyuki; Murakami, Tsutomu; Takaki, Naoyuki; Nishiguchi, Youhei; Sugino, Kazuteru; Naganuma, Masayuki; Hishida, Masahiko; et al.
JNC TN9400 2004-035, 2071 Pages, 2004/06
JNC-TN9400-2004-035.pdf:76.42MB
The attractive concepts for Sodium-, lead-bismuth-, helium- and water-cooled FBRs have been created through using typical plant features and employing advanced technologies. Efforts on evaluating technological prospects of feasibility have been paid for these concepts. Also, it was comfirmed if these concepts satisfy design requierments of capability and performance presumed in the feasibilty study on commertialization of Fast Breeder Reactor Systems. As results, it was concluded that the selection of sodium-cooled reactor was most rational for practical use of FBR technologies in 2015.
Am
)OOsaka, Masahiko; Mondo, Kenji; Ishi, Yohei; Tanaka, Kenya; Seki, Takayuki*; Kurosaki, Ken*; Uno, Masayoshi*; Yamanaka, Shinsuke*
no journal, ,
Oxygen potential of (PuAm)O were measured by thermogravimetry using HO/H gas equiribrium, as a fundamental part of investigation on phase relation for low-decontaminated fuel.
Sato, Isamu; Ishi, Yohei; Mondo, Kenji; Yoshimochi, Hiroshi; Tanaka, Kenya; Seki, Takayuki*
no journal, ,
Wieght changes of MOX fuels containing Am were measured during stored in a cell box. We observed that the O/M ratios of these fuels containing Am changed relatively rapidly.
Yoshimochi, Hiroshi; Ishi, Yohei; Tanaka, Kenya; Sekine, Shinichi*; Seki, Takayuki*
no journal, ,
no abstracts in English
Mondo, Kenji; Ishi, Yohei; Sato, Isamu; Yoshimochi, Hiroshi; Tanaka, Kenya; Seki, Takayuki*
no journal, ,
no abstracts in English
Sato, Isamu; Ishi, Yohei; Mondo, Kenji; Tanaka, Kenya; Seki, Takayuki*; Ishida, Takashi*
no journal, ,
A dependence of O/M ratio change behavior on atmosphere was evaluated, then these results indicated that the change rate of the O/M ratio depended on the concentration of water.
Am)OMiwa, Shuhei; Osaka, Masahiko; Mondo, Kenji; Ishi, Yohei; Yoshimochi, Hiroshi; Tanaka, Kenya; Seki, Takayuki*; Sekine, Shinichi*; Kurosaki, Ken*; Uno, Masayoshi*; et al.
no journal, ,
An experimental investigation on phase relation of (PuAm)O was carried out by X-ray diffraction (XRD) analysis, ceramography and Differential Thermal Analysis (DTA) for (PuAm)O having different O/M ratios from 1.90 to 2.00.
Tanaka, Kosuke; Osaka, Masahiko; Sato, Isamu; Miwa, Shuhei; Koyama, Shinichi; Ishi, Yohei; Hirosawa, Takashi; Obayashi, Hiroshi; Yoshimochi, Hiroshi; Tanaka, Kenya
no journal, ,
The present status of the research and development program for americium-containing MOX is reported. Successful achievements for development of fabrication technology with remote handling and evaluation of irradiation behavior together with evaluation of thermo-chemical properties based on the out-of-pile experiments are mentioned with emphasis on effects of Am addition on the MOX properties.
