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Nishimura, Hayato*; Hojo, Tomohiko*; Ajita, Saya*; Shibayama, Yuki*; Koyama, Motomichi*; Saito, Hiroyuki*; Shiro, Ayumi*; Yasuda, Ryo*; Shobu, Takahisa; Akiyama, Eiji*
Tetsu To Hagane, 107(9), p.760 - 768, 2021/09
Times Cited Count：0 Percentile：0(Metallurgy & Metallurgical Engineering)no abstracts in English
Nishimura, Shoichiro*; Torii, Hiroyuki*; Fukao, Yoshinori*; Ito, Takashi; Iwasaki, Masahiko*; Kanda, Sotaro*; Kawagoe, Kiyotomo*; Kawall, D.*; Kawamura, Naritoshi*; Kurosawa, Noriyuki*; et al.
Physical Review A, 104(2), p.L020801_1 - L020801_6, 2021/08
Times Cited Count：7 Percentile：81.08(Optics)Shibayama, Yuki; Hojo, Tomohiko*; Koyama, Motomichi*; Saito, Hiroyuki*; Shiro, Ayumi*; Yasuda, Ryo*; Shobu, Takahisa; Matsuno, Takashi*; Akiyama, Eiji*
ISIJ International, 61(4), p.1322 - 1329, 2021/04
Times Cited Count：2 Percentile：29.57(Metallurgy & Metallurgical Engineering)Nishimura, Hayato*; Hojo, Tomohiko*; Ajita, Saya*; Shibayama, Yuki*; Koyama, Motomichi*; Saito, Hiroyuki*; Shiro, Ayumi*; Yasuda, Ryo*; Shobu, Takahisa; Akiyama, Eiji*
ISIJ International, 61(4), p.1170 - 1178, 2021/04
Times Cited Count：2 Percentile：29.57(Metallurgy & Metallurgical Engineering)Hojo, Tomohiko*; Akiyama, Eiji*; Saito, Hiroyuki*; Shiro, Ayumi*; Yasuda, Ryo*; Shobu, Takahisa; Kinugasa, Junichiro*; Yuse, Fumio*
Corrosion Science, 177, p.108957_1 - 108957_9, 2020/12
Times Cited Count：14 Percentile：78.75(Materials Science, Multidisciplinary)Hydrogen assisted cracking on hemispherically-stretch-formed specimens of transformation induced plasticity-aided martensitic steel was investigated. Hydrogen charging induced cracking around the foot of the impression formed on the steel sheet, and the cracks propagated along the radial direction toward the hillside and the plains. Distributions of stress, plastic strain and volume fraction of retained austenite were analyzed employing the energy-dispersive X-ray diffraction method utilizing the synchrotron X-ray radiation at SPring-8. It was notable that the crack initiation took place in the region where the measured tensile stress was the highest. Influences of plastic strain and resulted martensitic transformation were also suggested.
Hojo, Tomohiko*; Kumai, B.*; Koyama, Motomichi*; Akiyama, Eiji*; Waki, Hiroyuki*; Saito, Hiroyuki*; Shiro, Ayumi*; Yasuda, Ryo*; Shobu, Takahisa; Nagasawa, Akihiko*
International Journal of Fracture, 224(2), p.253 - 260, 2020/08
Times Cited Count：12 Percentile：69.34(Materials Science, Multidisciplinary)In the study, the pre-strain effect on hydrogen embrittlement property of the ultra-high-strength transformation-induced plasticity -aided bainitic ferrite steel was investigated towards application for automobile frame parts. 3-10% tensile pre-strain suppressed hydrogen-induced mechanical degradation relative to total elongation while 12-15% pre-strained specimen did not exhibit elongation after hydrogen charging. The advantageous effect of the 3-10% pre-strain was attributed to the suppression of crack initiation related to retained austenite. The TRIP by pre-straining decreased the volume fraction of retained austenite before hydrogen charging, thereby reducing existing probabilities of preferential crack initiation sites and propagation paths. Conversely, high pre-strain such as 12-15% does not effectively work due to work hardening resulting in increases in hydrogen embrittlement susceptibility and a significant increase in hydrogen content due to the multiplication of dislocations.
F from 
O
?Tang, T. L.*; Uesaka, Tomohiro*; Kawase, Shoichiro; Beaumel, D.*; Dozono, Masanori*; Fujii, Toshihiko*; Fukuda, Naoki*; Fukunaga, Taku*; Galindo-Uribarri, A.*; Hwang, S. H.*; et al.
Physical Review Letters, 124(21), p.212502_1 - 212502_6, 2020/05
Times Cited Count：13 Percentile：75.1(Physics, Multidisciplinary)The structure of a neutron-rich F nucleus is investigated by a quasifree (
) knockout reaction. The sum of spectroscopic factors of 
orbital is found to be 1.0 
0.3. The result shows that the O core of F nucleus significantly differs from a free O nucleus, and the core consists of 
35% O
, and 65% excited O. The result shows that the O core of F nucleus significantly differs from a free O nucleus. The result may infer that the addition of the 
proton considerably changes the neutron structure in F from that in O, which could be a possible mechanism responsible for the oxygen dripline anomaly.
113
deformation twinning in metastable 
-type Ti alloy focusing on stress-induced 
martensite phaseCho, K.*; Morioka, Ryota*; Harjo, S.; Kawasaki, Takuro; Yasuda, Hiroyuki*
Scripta Materialia, 177, p.106 - 111, 2020/03
Times Cited Count：26 Percentile：92.69(Nanoscience & Nanotechnology)Koyanagi, Yoshihiko*; Ueta, Shigeki*; Kawasaki, Takuro; Harjo, S.; Cho, K.*; Yasuda, Hiroyuki*
Materials Science & Engineering A, 773, p.138822_1 - 138822_11, 2020/01
Times Cited Count：0 Percentile：0(Nanoscience & Nanotechnology)Wang, H.*; Otsu, Hideaki*; Chiga, Nobuyuki*; Kawase, Shoichiro*; Takeuchi, Satoshi*; Sumikama, Toshiyuki*; Koyama, Shumpei*; Sakurai, Hiroyoshi*; Watanabe, Yukinobu*; Nakayama, Shinsuke; et al.
Communications Physics (Internet), 2(1), p.78_1 - 78_6, 2019/07
Times Cited Count：7 Percentile：57.83(Physics, Multidisciplinary)Searching for effective pathways for the production of proton- and neutron-rich isotopes through an optimal combination of reaction mechanism and energy is one of the main driving forces behind experimental and theoretical nuclear reaction studies as well as for practical applications in nuclear transmutation of radioactive waste. We report on a study on incomplete fusion induced by deuteron, which contains one proton and one neutron with a weak binding energy and is easily broken up. This reaction study was achieved by measuring directly the cross sections for both proton and deuteron for 
Pd at 50 MeV/u via inverse kinematics technique. The results provide direct experimental evidence for the onset of a cross-section enhancement at high energy, indicating the potential of incomplete fusion induced by loosely-bound nuclei for creating proton-rich isotopes and nuclear transmutation of radioactive waste.
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：99.37Omori, Hiroyuki; Nebashi, Koji; Shimada, Asako; Tanaka, Kiwamu; Yasuda, Mari; Hoshi, Akiko; Tsuji, Tomoyuki; Ishimori, Kenichiro; Kameo, Yutaka
JAEA-Data/Code 2014-029, 31 Pages, 2015/03
JAEA-Data-Code-2014-029.pdf:1.51MB
Simple and rapid methods to evaluate the radioactivity concentrations are required for the radioactive waste generated from research facilities in the Japan Atomic Energy Agency to dispose of in a near-surface repository. In order to establish the methods to evaluate the radioactivity concentrations of miscellaneous solid waste generated from research and testing reactors, we collected and analyzed samples from miscellaneous solid waste generated by the decommissioning of JPDR (Japan Power Demonstration Reactor). In this report, we reported the analytical data determined in fiscal 2014 (
Cs and 
Mo) and summarized them with the radioactivity concentrations obtained in the past as basic data to consider the evaluation method of radioactivity concentrations in the stored waste taken from JPDR.
Onozawa, Atsushi; Harada, Akio; Honda, Junichi; Yasuda, Ryo; Nakata, Masahito; Kanazawa, Hiroyuki; Nishino, Yasuharu
JAEA-Conf 2006-003, p.212 - 221, 2006/05
In the Reactor Fuel Examination Facility (RFEF), a measuring method of hydrogen concentration by backscattered electron image analysis was improved to obtain more local hydrogen concentration data in fuel claddings. The sample preparation and image analysis procedures of this were able to measure hydrogen concentration efficiently and precisely.
Onozawa, Atsushi; Harada, Akio; Honda, Junichi; Yasuda, Ryo; Nakata, Masahito; Kanazawa, Hiroyuki; Nishino, Yasuharu
JAEA-Technology 2006-010, 19 Pages, 2006/03
JAEA-Technology-2006-010.pdf:2.3MB
A measurement technique for hydrogen concentration using Backscattered Electron Image analysis (BEI method) had been developed by Studsvik Nuclear AB, Sweden. The hydrides in claddings are identified using BEIs which are imaged with Scanning Electron Microscope, and the hydrogen concentrations are calculated from the area fractions of the hydrides in the matrix. The BEI method is very useful for the measurement in local hydrogen concentrations of fuel claddings. In the Reactor Fuel Examination Facility, a sample preparation, imaging conditions of SEM and image analysis procedures for the BEI method were improved. In addition, the hydrogen concentrations obtained by the improved BEI method and Hot Vacuum Extraction (HVE) method were compared to confirm the reliability of the improved BEI method. The results showed, the improved BEI method has the same reliability as that of HVE method and can be applied for the Post-Irradiation Examination.
Onozawa, Atsushi; Harada, Akio; Honda, Junichi; Yasuda, Ryo; Nakata, Masahito; Kanazawa, Hiroyuki; Nishino, Yasuharu
no journal, ,
Yasuda, Ryo; Nojima, Takehiro; Iikura, Hiroshi; Sakai, Takuro; Matsubayashi, Masahito; Yamamoto, Hiroyuki
no journal, ,
Nomoto, Yasunobu; Mizuta, Naoki; Morita, Keisuke; Aoki, Takeshi; Okita, Shoichiro; Ishii, Katsunori; Kurahayashi, Kaoru; Yasuda, Takanori; Tanaka, Masato; Isaka, Kazuyoshi; et al.
no journal, ,
no abstracts in English
Ishii, Katsunori; Mizuta, Naoki; Morita, Keisuke; Aoki, Takeshi; Kurahayashi, Kaoru; Yasuda, Takanori; Noguchi, Hiroki; Nomoto, Yasunobu; Shimizu, Atsushi; Iigaki, Kazuhiko; et al.
no journal, ,
no abstracts in English
