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Ebihara, Kenichi; Sekine, Daiki*; Sakiyama, Yuji*; Takahashi, Jun*; Takai, Kenichi*; Omura, Tomohiko*
International Journal of Hydrogen Energy, 48(79), p.30949 - 30962, 2023/09
Times Cited Count：0 Percentile：0.01(Chemistry, Physical)To understand hydrogen embrittlement (HE), which is one of the stress corrosion cracking of steel materials, it is necessary to know the H distribution in steel, which can be effectively interpreted by numerical simulation of thermal desorption spectra. In weld metals and TRIP steels, residual austenite significantly influences the spectra, but a clear H distribution is not well known. In this study, an originally coded two-dimensional model was used to numerically simulate the previously reported spectra of high-carbon ferritic-austenitic duplex stainless steels, and it was found that H is mainly trapped at the carbide surface when the amount of H in the steel is low and at the duplex interface when the amount of H is high. It was also found that the thickness dependence of the H desorption peak for the interface trap site is caused by a different reason than the conventional one.
Daimon, Shunsuke*; Uchida, Kenichi*; Ujiie, Naomi*; Hattori, Yasuyuki*; Tsuboi, Rei*; Saito, Eiji
Applied Physics Express, 13(10), p.103001_1 - 103001_4, 2020/10
Times Cited Count：7 Percentile：44.34(Physics, Applied)
O
thin filmsQin, J.*; Hou, D.*; Chen, Y.*; Saito, Eiji; Jin, X.*
Journal of Magnetism and Magnetic Materials, 501, p.166362_1 - 166362_4, 2020/05
Times Cited Count：4 Percentile：26.39(Materials Science, Multidisciplinary)Kirihara, Yoichi; Nakashima, Hiroshi; Sanami, Toshiya*; Namito, Yoshihito*; Itoga, Toshiro*; Miyamoto, Shuji*; Takemoto, Akinori*; Yamaguchi, Masashi*; Asano, Yoshihiro*
Journal of Nuclear Science and Technology, 57(4), p.444 - 456, 2020/04
Times Cited Count：8 Percentile：61.94(Nuclear Science & Technology)no abstracts in English
Oyanagi, Koichi*; Kikkawa, Takashi*; Saito, Eiji
AIP Advances (Internet), 10(1), p.015031_1 - 015031_5, 2020/01
Times Cited Count：15 Percentile：71.02(Nanoscience & Nanotechnology)
-FeO/NiO/Pt epitaxial stacksDong, B.-W.*; Baldrati, L.*; Schneider, C.*; Niizeki, Tomohiko*; Ramos, R.*; Ross, A.*; Cramer, J.*; Saito, Eiji; Kl
ui, M.*
Applied Physics Letters, 114(10), p.102405_1 - 102405_5, 2019/03
Times Cited Count：11 Percentile：49.82(Physics, Applied)Fukui, Katsunori*; Hashiba, Kimihiro*; Sato, Toshinori; Kuwabara, Kazumichi; Takayama, Yusuke
JAEA-Research 2015-015, 61 Pages, 2015/11
JAEA-Research-2015-015.pdf:5.52MB
With respect to high-level radioactive waste disposal, knowledge of the long-term mechanical stability of shafts and galleries excavated in rock is required, not only during construction and operation but also over a period of thousands of years after closure. On the other hand, it is known that rock and the rock mass surrounding the disposal gallery shows time dependent behavior such as creep or the stress-relaxation. It becomes the issue in the stability evaluation of the disposal gallery to grasp the behavior. About this issue, we pushed forward research development. In the fiscal year of 2014, the creep test was continuously conducted and the total testing time exceeded 17 years. The testing equipment and procedure were examined to investigate the deformation, failure and time-dependency of rock under wet conditions and between room temperature and 100
C. The long-term strength of rock under triaxial stress state was researched with the aid of laboratory testing results and in situ stress measurement.
Yokota, Yuichiro; Funayama, Tomoo; Muto, Yasuko*; Ikeda, Hiroko; Kobayashi, Yasuhiko
International Journal of Radiation Biology, 91(5), p.383 - 388, 2015/05
Times Cited Count：11 Percentile：64.63(Biology)We investigated the dependence of the bystander cell-killing effect on radiation dose and quality, and related molecular mechanisms. Human fibroblasts were irradiated with -rays or carbon ions and co-cultured with non-irradiated cells. Survival rates of non-irradiated cells decreased and nitrite concentrations in culture medium increased with increasing doses. Their dose responses were similar between -rays and carbon ions. Treatment of the specific nitric oxide (NO) radical scavenger prevented reductions in survival rates of non-irradiated cells. Negative relationships were observed between survival rates and nitrite concentrations. From these results, it was concluded that the bystander cell-killing effect mediated by NO radicals in human fibroblasts depends on irradiation doses, but not on radiation quality. NO radical production appears to be an important determinant of -ray- and carbon-ion-induced bystander effects.
Shimoyama, Iwao; Baba, Yuji; Sekiguchi, Tetsuhiro
DV-X
Kenkyu Kyokai Kaiho, 27(1&2), p.34 - 44, 2015/03
no abstracts in English
locus in normal human fibroblasts induced by C-, Ne- and Ar-ion microbeamsSuzuki, Masao*; Funayama, Tomoo; Yokota, Yuichiro; Muto, Yasuko*; Suzuki, Michiyo; Ikeda, Hiroko; Hattori, Yuya; Kobayashi, Yasuhiko
JAEA-Review 2014-050, JAEA Takasaki Annual Report 2013, P. 78, 2015/03
We have been studying the radiation-quality dependent bystander cellular effects, such as cell killing, mutation induction and chromosomal damage, using heavy-ion microbeams with different ion species. This year we focused on the ion-species dependent bystander mutagenic effect on locus in normal human fibroblasts. The confluent culture were irradiated using a 256 (16
16)-cross-stripe method using C, Ne and Ar microbeam. Gene mutation on locus was detected with 6-thioguanine resistant clones. The mutation frequency in cells irradiated with C-ion microbeams was 6 times higher than that of non-irradiated control cells and of the sample treated with specific inhibitor of gap-junction cell-to-cell communication. On the other hand, no enhanced mutation frequencies were observed in cells irradiated with either Ne- or Ar-ion microbeams. There is clear evidence that the bystander mutagenic effect via gap-junction communication depends on radiation quality.
C and 
HeAkeo, Kiyoshi*; Funayama, Tomoo; Kobayashi, Yasuhiko; Akeo, Yoko*
JAEA-Review 2014-050, JAEA Takasaki Annual Report 2013, P. 80, 2015/03
It is known that superoxide dismutases (SOD) are a class of enzymes that catalyze the dismutation of superoxide into oxygen and hydrogen peroxide. Ionizing radiation is known to induce oxidative stress through generation of reactive oxygen species resulting in imbalance of the pro-oxidant and antioxidant in the cells, which is suggested to culminate in cell death. Therefore, we measured the activity of SOD in human RE cells exposed to the He- and C-ion beam. The cells collected at 0, 4, 8, and 24 hr after irradiation were extracted by adding the SOD assay buffer to the pellets, and lysed by several cycles of freezing and thawing. The activity of SOD was measured using a modification of the luminol assay. SOD activity decreased according to duration time after irradiation of He-ion, however, in case of C-ion, it increased at 24 hr after irradiation. The result suggested that that there were the differences of the effects by irradiation on SOD activity between He- and C-ion.
Fukui, Katsunori*; Hashiba, Kimihiro*; Sato, Toshinori; Sanada, Hiroyuki; Kuwabara, Kazumichi
JAEA-Research 2014-020, 50 Pages, 2014/11
JAEA-Research-2014-020.pdf:2.8MB
On the radioactive waste disposal, the long-term mechanical stability of shafts and galleries excavated in rock is required. Therefore, it is very important to understand the time-dependent behavior of rock mass for evaluating long-term mechanical stability. The purpose of this study is determining the mechanisms of time-dependent behavior of rock mass by precise testing, observation and measurement in order to develop methods for evaluating long-term mechanical stability of a rock mass. This report describes the results of the activities in fiscal year 2013. In Chapter 1, we described the overview and background of this study. In Chapter 2, the results of a long-term creep test on Tage tuff, started in fiscal year 1997 are described. In Chapter 3, the result of organization and analysis for time-dependent behavior of crystalline rock was described. In Chapter 4, for the drafting of in-situ test plan, examination of the numerical analysis technique of rock mass was carried out.
Fukui, Hironobu*; Hamaguchi, Masafumi*; Yoshimura, Hisao*; Oyamatsu, Hisato*; Matsuoka, Fumitomo*; Noguchi, Tatsuo*; Hirao, Toshio; Abe, Hiroshi; Onoda, Shinobu; Yamakawa, Takeshi; et al.
Proceedings of 2005 Symposia on VLSI Technology and Circuits, p.222 - 223, 2005/00
no abstracts in English
Nakabayashi, Masakazu*; Oyama, Hidenori*; Hanano, N.*; Hirao, Toshio; Simoen, E.*; Claeys, C.*
Proceedings of the 6th International Workshop on Radiation Effects on Semiconductor Devices for Space Application (RASEDA-6), p.183 - 186, 2004/10
no abstracts in English
-BN thin film on Ni(111) using NEXAFS spectroscopyShimoyama, Iwao; Baba, Yuji; Sekiguchi, Tetsuhiro; Nath, K. G.
Hyomen Kagaku, 25(9), p.555 - 561, 2004/09
no abstracts in English
Shimoyama, Iwao; Baba, Yuji; Sekiguchi, Tetsuhiro; Nath, K. G.
Journal of Electron Spectroscopy and Related Phenomena, 137-140, p.573 - 578, 2004/07
Times Cited Count：27 Percentile：72.98(Spectroscopy)Hexagonal boron nitride (h-BN) thin film has been epitaxially formed on Ni(111) by chemical vapor deposition using borazine gas. The electronic structure of this system is studied by near edge X-ray absorption fine structure (NEXAFS) spectroscopy and X-ray photoelectron spectroscopy (XPS). The thickness of the h-BN is estimated to be about two-layers from XPS. B K-edge NEXAFS spectra show new 
* peak which is not observed in the spectrum for bulk h-BN. From a polarization dependence analysis of NEXAFS, we propose this new * peak originates from the interaction between the h-BN and Ni(111). This new * peak clearly proves that conduction band of h-BN/Ni(111) is different from that of bulk h-BN.
Tamura, Koji
Shinku, 47(6), p.477 - 479, 2004/06
The lateral distributions of the laser photoionized neodymium ion at the ion energy between 1400eV and 300eV were measured with a multi-channel Faraday cup. The obtained ions were collimated within these energy regions, and are considered to be useful for the applications of the laser photoionized ions.
Nishikawa, Yunori; Usuda, Manabu; Igarashi, Junichi*; Shoji, Hironobu*; Iwazumi, Toshiaki*
Journal of the Physical Society of Japan, 73(4), p.970 - 975, 2004/04
Times Cited Count：6 Percentile：41.19(Physics, Multidisciplinary)no abstracts in English
Chakoumakos, B. C.*; Rawn, C. J.*; Rondinone, A. J.*; Marshall, S. L.*; Stern, L. A.*; Circone, S.*; Kirby, S. H.*; Jones, C. Y.*; Toby, B. H.*; Ishii, Yoshinobu
Proceedings of 4th International Conference on Gas Hydrates (ICGH-4), p.655 - 658, 2002/05
no abstracts in English
Rawn, C. J.*; Rondinone, A. J.*; Chakoumakos, B. C.*; Marshall, S. L.*; Stern, L. A.*; Circone, S.*; Kirby, S. H.*; Jones, C. Y.*; Toby, B. H.*; Ishii, Yoshinobu
Proceedings of 4th International Conference on Gas Hydrates (ICGH-4), p.595 - 598, 2002/05
no abstracts in English
