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Johnstone, E. V.*; Bailey, D. J.*; Lawson, S.*; Stennett, M. C.*; Corkhill, C. L.*; Kim, M.*; Heo, J.*; Matsumura, Daiju; Hyatt, N. C.*
RSC Advances (Internet), 10(42), p.25116 - 25124, 2020/07
Times Cited Count:3 Percentile:14.84(Chemistry, Multidisciplinary)Kurikami, Hiroshi; Malins, A.; Takeishi, Minoru; Saito, Kimiaki; Iijima, Kazuki
Journal of Environmental Radioactivity, 171, p.99 - 109, 2017/05
Times Cited Count:14 Percentile:42.77(Environmental Sciences)A modified diffusion-sorption-fixation model (mDSF) is proposed to describe the vertical migration of radiocesium in soils following fallout. The model introduces kinetics for reversible sites, meaning that the exponential-shape radiocesium distribution can be reproduced immediately following fallout. The initial relaxation mass depth of the distribution is determined by the diffusion length, which depends on the distribution coefficient, sorption rate and dispersion coefficient. The model captures the long tails of the radiocesium distribution at large depths. These tails are caused by different rates for kinetic sorption and desorption.
Oshima, Takeshi; Ito, Hisayoshi
Proceedings of the 6th International Workshop on Radiation Effects on Semiconductor Devices for Space Application (RASEDA-6), p.191 - 194, 2004/10
no abstracts in English
Yamamoto, Toshihiro; Miyoshi, Yoshinori
Journal of Nuclear Science and Technology, 41(2), p.99 - 107, 2004/02
Times Cited Count:38 Percentile:89.97(Nuclear Science & Technology)A new algorithm of Monte Carlo criticality calculations for implementing Wielandt's method is developed. In this algorithm, part of fission neutrons emitted during random walk processes are tracked within the same generation, and thus a fission source distribution in the next generation spread more widely. Applying this method intensifies a neutron interaction effect even in a loosely-coupled array where conventional Monte Carlo criticality calculation methods have difficulties, and a converged fission source distribution can be obtained with fewer generations. Computing time spent for one generation, however, increases because of tracking fission neutrons within the same generation, which eventually results in an increase of total computing time up to convergence. However, since a fission source convergence is attained with fewer source iterations, a reliable determination of convergence can easily be made even in a system with a slow convergence.
Yoshikawa, Masahito; Ishida, Yuki*; Jikimoto, Tamotsu*; Hijikata, Yasuto*; Ito, Hisayoshi; Okumura, Hajime*; Takahashi, Tetsuo*; Tsuchida, Hidekazu*; Yoshida, Sadafumi*
Denshi Joho Tsushin Gakkai Rombunshi, C, 86(4), p.426 - 433, 2003/04
no abstracts in English
Yoritsune, Tsutomu; Ishida, Toshihisa; Imayoshi, Sho*
Journal of Nuclear Science and Technology, 39(8), p.913 - 922, 2002/08
Times Cited Count:4 Percentile:29(Nuclear Science & Technology)no abstracts in English
Shimizu, Shigeru; Nemoto, Hisashi*; Kurosawa, Koji*; Yoshizawa, Michio
JAERI-Tech 2000-041, 31 Pages, 2000/05
no abstracts in English
Yoshikawa, Masahito; Kojima, Kazutoshi; Oshima, Takeshi; Ito, Hisayoshi; Okada, Sohei; Ishida, Yuki*
Materials Science Forum, 338-342, p.1129 - 1132, 2000/00
no abstracts in English
Yoshikawa, Masahito; Takahashi, Kunimasa*; Oshima, Takeshi; Kitabatake, Makoto*; Ito, Hisayoshi
Proceedings of 1st International Workshop on Ultra-Low-Loss Power Device Technology (UPD2000), p.199 - 200, 2000/00
no abstracts in English
Takahashi, Yoshihiro*; Onishi, Kazunori*; Fujimaki, Takeshi*; Yoshikawa, Masahito
IEEE Transactions on Nuclear Science, 46(6), p.1578 - 1585, 1999/12
Times Cited Count:23 Percentile:82.99(Engineering, Electrical & Electronic)no abstracts in English
Sato, Haruo
JNC TN8400 99-061, 9 Pages, 1999/10
The porosities and dry densities for rock samples sampled from a fractured zone (fracture type C: composed of intact ganodiorite, altered ganodiorite and fracture fillings) at the Kamaishi mine were obtained by a water saturation (intrusion) method as input parameters for nuclide migration analysis in performance assessment of the geological disposal of high-level radioactive waste. Consequently, the average porosity, 8.60.43% was higher than those of fracture fillings, altered garnodiorite and intact ganodiorite composing fracture type B with a single fracture taken from the Kamaishi mine so far. While, the average dry density, 2.430.0089 Mgm, was lower than those of rocks composing the fracture type B. Based on this, it is predicted that radionuclides are the easiest to migrate in the fracture zone.
Oshima, Takeshi; Yoshikawa, Masahito; Ito, Hisayoshi; Aoki, Yasushi; Nashiyama, Isamu
Mater. Sci. Eng. B, 61-62, p.480 - 484, 1999/00
Times Cited Count:23 Percentile:73.95(Materials Science, Multidisciplinary)no abstracts in English
Oshima, Takeshi; Yoshikawa, Masahito; Ito, Hisayoshi; Aoki, Yasushi; Nashiyama, Isamu
Japanese Journal of Applied Physics, Part 2, 37(8B), p.L1002 - L1004, 1998/08
Times Cited Count:15 Percentile:57.69(Physics, Applied)no abstracts in English
Yoshikawa, Masahito; Oshima, Takeshi; Ito, Hisayoshi; Nashiyama, Isamu; *; Onishi, K.*; Okumura, Hajime*; Yoshida, Sadafumi*
Denshi Joho Tsushin Gakkai Rombunshi, C-II, 81(1), p.140 - 150, 1998/01
no abstracts in English
Sakurai, Tsutomu; ;
Journal of Nuclear Science and Technology, 35(1), p.76 - 81, 1998/01
Times Cited Count:3 Percentile:31.9(Nuclear Science & Technology)no abstracts in English
Yoshikawa, Masahito; Oshima, Takeshi; Ito, Hisayoshi; Nashiyama, Isamu; Takahashi, Yoshihiro*; Onishi, K.*; Okumura, Hajime*; Yoshida, Sadafumi*
Electronics and Communication in Japan., Part2, 81(10), p.37 - 47, 1998/00
no abstracts in English
Yoshikawa, Masahito; *; Oshima, Takeshi; Ito, Hisayoshi; Nashiyama, Isamu; *; Onishi, K.*; Okumura, Hajime*; Yoshida, Sadafumi*
Mater. Sci. Forum, 264-268, p.1017 - 1020, 1998/00
no abstracts in English
Oshima, Takeshi; Yoshikawa, Masahito; Ito, Hisayoshi; Nashiyama, Isamu; Okada, Sohei
Proceedings of 3rd International Workshop on Radiation Effects on Semiconductor Devices for Space Application, p.22 - 27, 1998/00
no abstracts in English
Nakano, Yoshihiro; Takano, Hideki; Akie, Hiroshi
JAERI-Research 97-051, 31 Pages, 1997/07
no abstracts in English
Yoshikawa, Masahito; *; Oshima, Takeshi; Ito, Hisayoshi; Nashiyama, Isamu; Okumura, Hajime*; Yoshida, Sadafumi*
Radiation Physics and Chemistry, 50(5), p.429 - 433, 1997/00
Times Cited Count:0 Percentile:0.01(Chemistry, Physical)no abstracts in English