Refine your search:     
Report No.
 - 
Search Results: Records 1-20 displayed on this page of 64

Presentation/Publication Type

Initialising ...

Refine

Journal/Book Title

Initialising ...

Meeting title

Initialising ...

First Author

Initialising ...

Keyword

Initialising ...

Language

Initialising ...

Publication Year

Initialising ...

Held year of conference

Initialising ...

Save select records

Journal Articles

Thermally altered subsurface material of asteroid (162173) Ryugu

Kitazato, Kohei*; Milliken, R. E.*; Iwata, Takahiro*; Abe, Masanao*; Otake, Makiko*; Matsuura, Shuji*; Takagi, Yasuhiko*; Nakamura, Tomoki*; Hiroi, Takahiro*; Matsuoka, Moe*; et al.

Nature Astronomy (Internet), 5(3), p.246 - 250, 2021/03

 Times Cited Count:21 Percentile:98.04(Astronomy & Astrophysics)

Here we report observations of Ryugu's subsurface material by the Near-Infrared Spectrometer (NIRS3) on the Hayabusa2 spacecraft. Reflectance spectra of excavated material exhibit a hydroxyl (OH) absorption feature that is slightly stronger and peak-shifted compared with that observed for the surface, indicating that space weathering and/or radiative heating have caused subtle spectral changes in the uppermost surface. However, the strength and shape of the OH feature still suggests that the subsurface material experienced heating above 300 $$^{circ}$$C, similar to the surface. In contrast, thermophysical modeling indicates that radiative heating does not increase the temperature above 200 $$^{circ}$$C at the estimated excavation depth of 1 m, even if the semimajor axis is reduced to 0.344 au. This supports the hypothesis that primary thermal alteration occurred due to radiogenic and/or impact heating on Ryugu's parent body.

Journal Articles

Safety demonstration project on disposing of contaminated soil in Tokai-mura

Murata, Chinatsu; Kitahara, Masaru; Tanaka, Kiwamu; Amazawa, Hiroya; Takebe, Shinichi; Yamada, Osamu*; Kameo, Yutaka

Dekomisshoningu Giho, (62), p.20 - 31, 2020/09

On the basis of Act on Special Measures, municipalities stripped surface soil off the playground of park to decontaminate the soil which had been contaminated with radionuclides released from Fukushima Daiichi Nuclear Power Plant. To minimize the exposure dose of the residents, it was essential to decide safe disposal of the contaminated soil which has been stored at temporary storage areas. Therefore, the ministry of the Environment and Tokai-mura office required Japan Atomic Energy Agency (JAEA) to perform demonstration project of burying the contaminated soil generated by decontamination of public facilities in order to provide decision on the enforcement ordinance and guidelines of burying it. In this project, we acquired data of air dose rate and the personal exposure dose during transporting, burying, and storing the contaminated soil. In addition, we measured radioactivity concentration of dust collected from surroundings of the landfill and seepage water through contaminated soil.

Journal Articles

New precise measurements of muonium hyperfine structure at J-PARC MUSE

Strasser, P.*; Abe, Mitsushi*; Aoki, Masaharu*; Choi, S.*; Fukao, Yoshinori*; Higashi, Yoshitaka*; Higuchi, Takashi*; Iinuma, Hiromi*; Ikedo, Yutaka*; Ishida, Katsuhiko*; et al.

EPJ Web of Conferences, 198, p.00003_1 - 00003_8, 2019/01

 Times Cited Count:12 Percentile:99.55

Journal Articles

Development of radiation resistant monitoring camera system

Takeuchi, Tomoaki; Otsuka, Noriaki; Watanabe, Takashi*; Tanaka, Shigeo*; Ozawa, Osamu*; Komanome, Hirohisa*; Ueno, Shunji*; Tsuchiya, Kunihiko

Proceedings of 2017 IEEE Nuclear Science Symposium and Medical Imaging Conference (NSS/MIC 2017) (Internet), 3 Pages, 2018/11

no abstracts in English

Journal Articles

New precise measurement of muonium hyperfine structure interval at J-PARC

Ueno, Yasuhiro*; Aoki, Masaharu*; Fukao, Yoshinori*; Higashi, Yoshitaka*; Higuchi, Takashi*; Iinuma, Hiromi*; Ikedo, Yutaka*; Ishida, Katsuhiko*; Ito, Takashi; Iwasaki, Masahiko*; et al.

Hyperfine Interactions, 238(1), p.14_1 - 14_6, 2017/11

 Times Cited Count:3 Percentile:89.41

Journal Articles

New muonium HFS measurements at J-PARC/MUSE

Strasser, P.*; Aoki, Masaharu*; Fukao, Yoshinori*; Higashi, Yoshitaka*; Higuchi, Takashi*; Iinuma, Hiromi*; Ikedo, Yutaka*; Ishida, Katsuhiko*; Ito, Takashi; Iwasaki, Masahiko*; et al.

Hyperfine Interactions, 237(1), p.124_1 - 124_9, 2016/12

 Times Cited Count:7 Percentile:93.47

Journal Articles

Gamma irradiation effects of image sensor for radiation-resistant camera

Takeuchi, Tomoaki; Otsuka, Noriaki; Tsuchiya, Kunihiko; Tanaka, Shigeo*; Ozawa, Osamu*; Komanome, Hirohisa*; Watanabe, Takashi*; Ueno, Shunji*

Nihon Hozen Gakkai Dai-13-Kai Gakujutsu Koenkai Yoshishu, p.391 - 394, 2016/07

no abstracts in English

Journal Articles

Development of flow-induced vibration evaluation methodology based on unsteady fluid flow analysis for large diameter pipe with elbow in JSFR

Hayakawa, Satoshi*; Ishikura, Shuichi*; Watanabe, Osamu*; Kaneko, Tetsuya*; Yamano, Hidemasa; Tanaka, Masaaki

Proceedings of 8th Japan-Korea Symposium on Nuclear Thermal Hydraulics and Safety (NTHAS-8) (USB Flash Drive), 10 Pages, 2012/12

The present methodology was applied to the analysis for the 1/3-scale experiment of the hot-leg pipe of JSFR, and the predicted stress values were compared with the measured stress values. The predicted stress values were underestimated in the case of using the intact pressure fluctuations obtained by the unsteady fluid flow analysis. Therefore, the improvement of the prediction accuracy of the pressure fluctuations on the pipe wall was attempted.

Journal Articles

Identification of the cathode reaction accompanied with overpack corrosion

Otsuka, Ichiro*; Iida, Yoshihisa; Yamaguchi, Tetsuji; Kato, Osamu*; Tateishi, Tsuyoshi*; Tanaka, Tadao

Materials Research Society Symposium Proceedings, Vol.1475, p.507 - 512, 2012/06

We conducted corrosion experiments of carbon wires to identify the cathode reaction with overpack corrosion. Carbon steel wires were immersed in selected aqueous solutions of distilled water, sodium hydrogen carbonate solution and sodium sulfate solution sealed in glass ampoules. The ampoules were kept at 60 $$^{circ}$$C for 150 days. Corrosion products, liquid phase and gas phases were analyzed. The results showed that hydrogen gas generation by reduction of hydrogen ions was dominant cathode reaction. Reduction of sulfate and carbonate anions was not observed. Amorphous ferrous hydroxide and/or iron oxides were identified in all the experiments as the corrosion products. Iron carbonate was also identified in the sodium hydrogen carbonate solution. This result indicates that the hydrogen generation reaction might be the dominant cathode reaction under geological disposal environment and that the Eh of the pore water would reach the equilibrium potential of the hydrogen generation reaction.

Journal Articles

Development of flow-induced vibration evaluation methodology for large-diameter piping with elbow in Japan sodium-cooled fast reactor

Yamano, Hidemasa; Tanaka, Masaaki; Kimura, Nobuyuki; Ohshima, Hiroyuki; Kamide, Hideki; Watanabe, Osamu*

Nuclear Engineering and Design, 241(11), p.4464 - 4475, 2011/11

 Times Cited Count:17 Percentile:76.35(Nuclear Science & Technology)

This paper describes the current status of flow-induced vibration evaluation methodology development for the primary piping in JSFR, in particular emphasizing on the development approach and research activities that investigate unsteady hydraulic characteristics in a short-elbow piping. Experimental efforts have been made using 1/3-scale and 1/10-sca1e single elbow test sections for the hot-leg piping and 1/4-scale and 1/7-scale triple-elbow test sections for the cold-leg piping. Recent experiments using the 1/3-scale test section revealed that a swirl flow at the inlet of the hot-leg piping hardly influenced the pressure fluctuations onto the pipe. Simulation activities include Unsteady Reynolds Averaged Navier Stokes equation (U-RANS) and Large Eddy Simulation (LES) approaches. Numerical results using the U-RANS approach appear in this paper, indicating its applicability to the hot-leg piping experiments.

JAEA Reports

Study of RC method on reclamation project in the uranium mine, 2 (Joint research)

Tanaka, Masaru*; Gofuku, Akio*; Ishizaka, Kaoru*; Tokizawa, Takayuki; Sato, Kazuhiko; Koga, Osamu

JAEA-Research 2010-054, 76 Pages, 2011/02

JAEA-Research-2010-054.pdf:4.46MB

To obtain public understanding on the uranium mining sites reclamation at Ningyo-toge Environmental Engineering Center, it is necessary to conduct appropriate Risk Communication (RC). In this study, to discuss the appropriate Risk communication method on the uranium mining sites reclamation, making of explanatory material by university student, and questionnaire survey on the risk perception were conducted.

Journal Articles

Dynamics of ion internal transport barrier in LHD heliotron and JT-60U tokamak plasmas

Ida, Katsumi*; Sakamoto, Yoshiteru; Yoshinuma, Mikiro*; Takenaga, Hidenobu; Nagaoka, Kenichi*; Hayashi, Nobuhiko; Oyama, Naoyuki; Osakabe, Masaki*; Yokoyama, Masayuki*; Funaba, Hisamichi*; et al.

Nuclear Fusion, 49(9), p.095024_1 - 095024_9, 2009/09

 Times Cited Count:29 Percentile:74.13(Physics, Fluids & Plasmas)

Dynamics of ion internal transport barrier (ITB) formation and impurity transport both in the Large Helical Device (LHD) heliotron and JT-60U tokamak are described. Significant differences between heliotron and tokamak plasmas are observed. The location of the ITB moves outward during the ITB formation regardless of the sign of magnetic shear in JT-60U and the ITB becomes more localized in the plasma with negative magnetic shear. In LHD, the low Te/Ti ratio ($$<$$ 1) of the target plasma for the high power heating is found to be necessary condition to achieve the ITB plasma and the ITB location tends to expand outward or inward depending on the condition of the target plasmas. Associated with the formation of ITB, the carbon density tends to be peaked due to inward convection in JT-60U, while the carbon density becomes hollow due to outward convection in LHD. The outward convection observed in LHD contradicts the prediction by neoclassical theory.

Journal Articles

Unsteady hydraulic characteristics in large-diameter pipings with elbow for JSFR, 1; Current status of flow-induced vibration evaluation methodology development for the JSFR pipings

Yamano, Hidemasa; Tanaka, Masaaki; Kimura, Nobuyuki; Ohshima, Hiroyuki; Kamide, Hideki; Watanabe, Osamu*

Proceedings of 13th International Topical Meeting on Nuclear Reactor Thermal Hydraulics (NURETH-13) (CD-ROM), 18 Pages, 2009/09

This paper describes the current status of flow-induced vibration evaluation methodology development for the primary cooling pipings in JSFR, in particular emphasizing on R&D activities that investigate unsteady hydraulic characteristics in a short-elbow piping. Experimental efforts have been made using 1/3-scale and 1/10-scale single-elbow test sections for the hot-leg piping and 1/4-scale and 1/7-scale triple-elbow test sections for the cold-leg piping. Simulation activities include Unsteady Reynolds Averaged Naviar Stokes equation (U-RANS) approach with Reynolds Stress Model (RSM) using a CFD code and Large Eddy Simulation (LES) approach using in-house codes. Numerical results appears in this paper, focusing on its applicability to the hot-leg piping experiments. The numerical results could be provided to the input data for the structural vibration evaluation of the piping. The procedure of the flow-induced vibration evaluation is also described in this paper.

JAEA Reports

Study of RC method on reclamation project in the uranium mine (Joint research)

Ishizaka, Kaoru*; Tanaka, Masaru*; Suzuki, Kazuhiko*; Tokizawa, Takayuki; Sato, Kazuhiko; Koga, Osamu

JAEA-Research 2008-086, 64 Pages, 2008/12

JAEA-Research-2008-086.pdf:1.99MB

In this study, to discuss the appropriate Risk Communication (RC) method on the uranium mining sites reclamation, comparative investigation of RC cases which concern the siting of solid waste management facilities and nuclear facilities, and questionnaire survey on the risk perception of landfill were conducted. As a result of comparative investigation, information disclosure and supplement are important factor to obtain public trust on the siting plan and developer. As assumption of the public participation, it is necessary the safety assurance of the siting plan and regional development plan cover a long period. As a result of questionnaire survey, it was shown that the almost people worried about health and the environmental impact of radioactive waste; moreover, there are a lot of ratios of the peoples who felt a dangerous and scary sensuously.

Journal Articles

The H-Invitational Database (H-InvDB); A Comprehensive annotation resource for human genes and transcripts

Yamasaki, Chisato*; Murakami, Katsuhiko*; Fujii, Yasuyuki*; Sato, Yoshiharu*; Harada, Erimi*; Takeda, Junichi*; Taniya, Takayuki*; Sakate, Ryuichi*; Kikugawa, Shingo*; Shimada, Makoto*; et al.

Nucleic Acids Research, 36(Database), p.D793 - D799, 2008/01

 Times Cited Count:51 Percentile:73.21(Biochemistry & Molecular Biology)

Here we report the new features and improvements in our latest release of the H-Invitational Database, a comprehensive annotation resource for human genes and transcripts. H-InvDB, originally developed as an integrated database of the human transcriptome based on extensive annotation of large sets of fulllength cDNA (FLcDNA) clones, now provides annotation for 120 558 human mRNAs extracted from the International Nucleotide Sequence Databases (INSD), in addition to 54 978 human FLcDNAs, in the latest release H-InvDB. We mapped those human transcripts onto the human genome sequences (NCBI build 36.1) and determined 34 699 human gene clusters, which could define 34 057 protein-coding and 642 non-protein-coding loci; 858 transcribed loci overlapped with predicted pseudogenes.

JAEA Reports

Announced document collection of the 1st Information Exchange Meeting on Radioactive Waste Disposal Research Network (Joint research)

Nakayama, Shinichi; Nagasaki, Shinya*; Inagaki, Yaohiro*; Oe, Toshiaki*; Sasaki, Takayuki*; Sato, Seichi*; Sato, Tsutomu*; Tanaka, Satoru*; Tochiyama, Osamu*; Nagao, Seiya*; et al.

JAEA-Conf 2007-003, 120 Pages, 2007/03

JAEA-Conf-2007-003.pdf:53.18MB

The 1st information exchange meeting on Radioactive Waste Disposal Research Network was held in Nuclear Science Research Institute of Japan Atomic Energy Agency on August 4, 2006. Radioactive Waste Disposal Research Network was established by under Interorganization Atomic Energy Research Program of Japan Atomic Energy Agency, and the objective is to bring both research infrastructures and human expertise in Japan to an adequate performance level, thereby contributing to the development of the fundamental research area in the field of radioactive waste disposal. This lecture material is a collection of research presentations and discussions during the information exchange meeting.

Journal Articles

Introduction to plasma fusion energy

Takamura, Shuichi*; Kado, Shinichiro*; Fujii, Takashi*; Fujiyama, Hiroshi*; Takabe, Hideaki*; Adachi, Kazuo*; Morimiya, Osamu*; Fujimori, Naoji*; Watanabe, Takayuki*; Hayashi, Yasuaki*; et al.

Kara Zukai, Purazuma Enerugi No Subete, P. 164, 2007/03

no abstracts in English

Journal Articles

Development of completely Solenoidless tokamak operation in JT-60U

Ushigome, Masahiro*; Ide, Shunsuke; Ito, Satoshi*; Jotaki, Eriko*; Mitarai, Osamu*; Shiraiwa, Shunichi*; Suzuki, Takahiro; Takase, Yuichi*; Tanaka, Shigetoshi*; Fujita, Takaaki; et al.

Nuclear Fusion, 46(2), p.207 - 213, 2006/02

 Times Cited Count:11 Percentile:38.32(Physics, Fluids & Plasmas)

This papaer studies on tokamak plasma start-up completely without central solenoid (CS). On the JT-60 tokamak it is demonstrated that a completely CS-less Ip start-up to 100 kA was achieved even without any null-point by Electron cyclotron range of frequencies (ECRF) and outer PF coil current swing only. Necessary conditions (the EC power, the toroidal field etc.) were clarified. Moreover, it was succeded to maintain Ip = 260kA for 1 sec without CS by NB only. In addition Ip ramp-up by EC and NB only (without LHCD) from 215 to 310kA was achieved. In a high confinement reversed shear discharge, a result suggesting bootstrap over drive was obtained.

Journal Articles

Characterization of pathways dependent on the ${it uvsE}$, ${it uvrA1}$ or ${it uvrA2}$ gene product for UV resistance in ${it Deinococcus radiodurans}$

Tanaka, Masashi*; Narumi, Issei; Funayama, Tomoo; Kikuchi, Masahiro; Watanabe, Hiroshi*; Matsunaga, Tsukasa*; Nikaido, Osamu*; Yamamoto, Kazuo*

Journal of Bacteriology, 187(11), p.3693 - 3697, 2005/06

 Times Cited Count:39 Percentile:57.11(Microbiology)

no abstracts in English

JAEA Reports

Feasibility Study on Commercialization of Fast Breeder Reactor Cycle Systems Interim Report of Phase II; Technical Study Report for Reactor Plant Systems

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.

64 (Records 1-20 displayed on this page)