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Toyomori, Yuka*; Tsuji, Satoru*; Mitsuda, Shinobu*; Okayama, Yoichi*; Ashida, Shiomi*; Mori, Atsunori*; Kobayashi, Toru; Miyazaki, Yuji; Yaita, Tsuyoshi; Arae, Sachie*; et al.
Bulletin of the Chemical Society of Japan, 89(12), p.1480 - 1486, 2016/09
Times Cited Count：9 Percentile：29.19(Chemistry, Multidisciplinary)
As using high-resolution inelastic X-ray scatteringMurai, Naoki*; Fukuda, Tatsuo; Kobayashi, Tatsuya*; Nakajima, Masamichi*; Uchiyama, Hiroshi*; Ishikawa, Daisuke*; Tsutsui, Satoshi*; Nakamura, Hiroki; Machida, Masahiko; Miyasaka, Shigeki*; et al.
Physical Review B, 93(2), p.020301_1 - 020301_5, 2016/01
Times Cited Count：7 Percentile：30.85(Materials Science, Multidisciplinary)Katata, Genki; Chino, Masamichi; Kobayashi, Takuya; Terada, Hiroaki; Ota, Masakazu; Nagai, Haruyasu; Kajino, Mizuo*; Draxler, R.*; Hort, M.*; Malo, A.*; et al.
Atmospheric Chemistry and Physics, 15(2), p.1029 - 1070, 2015/01
Times Cited Count：253 Percentile：98.82(Environmental Sciences)We estimated a detailed time trend of atmospheric releases during the Fukushima Dai-ichi Power Station (FNPS1) accident by combining environmental monitoring data with coupling simulation of atmospheric model of WSPEEDI-II, and oceanic dispersion model of SEA-GEARN-FDM. The new scheme of dry and fogwater depositions, in-cloud scavenging, cloud condensation nuclei activity, and wet scavenging by ice phase for radioactive iodine gas and other particles was incorporated into WSPEEDI-II. The results revealed that the major releases of radionuclides occurred in the following periods: afternoon on 12 March when the wet venting and hydrogen explosion at Unit 1, morning on 13 March after the venting event at Unit 3, midnight on 14 March when three-time openings of SRV were conducted at Unit 2, morning and night on 15 March, and morning on 16 March.
Kobayashi, Takuya; Nagai, Haruyasu; Chino, Masamichi; Kawamura, Hideyuki
Journal of Nuclear Science and Technology, 50(3), p.255 - 264, 2013/03
Times Cited Count：155 Percentile：99.68(Nuclear Science & Technology)The source term of the atmospheric release of 
I and 
Cs due to the Fukushima Dai-ichi Nuclear Power Plant accident estimated by previous studies was validated and refined by coupling atmospheric and oceanic dispersion simulations with observed 
Cs in seawater collected from the Pacific Ocean. By assuming the same release rate for Cs and Cs, the sea surface concentration of Cs was calculated using the previously estimated source term and was compared with measurement data. The release rate of Cs was refined to reduce underestimation of measurements, which resulted in a larger value than that previously estimated. In addition, the release rate of I was refined to follow the radioactivity ratio of Cs. As a result, the total amounts of I and Cs discharged into the atmosphere from 5 JST on March 12 to 0 JST on March 20 were estimated to be approximately 2.0
10
and 1.310
Bq, respectively.
Nagai, Haruyasu; Chino, Masamichi; Terada, Hiroaki; Harayama, Takaya*; Kobayashi, Takuya; Tsuzuki, Katsunori; Kim, K.; Furuno, Akiko
JAEA-Research 2006-057, 67 Pages, 2006/09
JAEA-Research-2006-057.pdf:13.49MB
A numerical simulation system SPEEDI-MP has been developed to apply for various environmental studies. SPEEDI-MP consists of dynamical models and material transport models for the atmospheric, terrestrial, and oceanic environments, database for model inputs, and system utilities for file management, visualization, etc. As a numerical simulation tool, a model coupling program (model coupler) has been developed. A coupled model system for water circulation has been constructed with atmosphere, ocean, wave, hydrology, and land-surface models using the model coupler. System utility GUIs are based on the Web technology, allowing users to manipulate all the functions on the system using their own PCs via the internet. In this system, the source estimation function in the atmospheric transport model can be executed on the grid computer system. Performance tests of the coupled model system for water circulation were also carried out for the flood and the storm surge events.
Kobayashi, Takuya; Chino, Masamichi; Togawa, Orihiko
Journal of Nuclear Science and Technology, 43(5), p.569 - 575, 2006/05
Times Cited Count：4 Percentile：29.50(Nuclear Science & Technology)A dissolved radionuclide migration code system that consists of a ocean circulation model, Princeton Ocean Model, and a particle random-walk model, SEA-GEARN, has been developed. The oceanic migration of Cs discharged from a nuclear submarine in a hypothetical accident at the Tsushima Strait was calculated in the southwestern area of the Japan Sea as a model application. The calculations for instantaneous releases every 10 days were carried out for one year to study the seasonal differences of migration process of the dissolved radionuclides. The migration tendencies of dissolved radionuclides were divided into two patterns. For the releases started from January to September, all of the high concentration areas migrated to the northeast along the coastline of the Main Island of Japan from the release point. As for the releases from October to December, some high concentrations areas migrated to the west from the release point and the concentrations of Cs along the coastline of the Main Island of Japan were comparatively low.
Suzuki, Yoshio; Matsumoto, Nobuko*; Yamagishi, Nobuhiro*; Higuchi, Kenji; Otani, Takayuki; Nagai, Haruyasu; Terada, Hiroaki; Furuno, Akiko; Chino, Masamichi; Kobayashi, Takuya
Computational Science - ICCS 2003, International Conference Saint Petersburg Russian Federation, Melbourne Australia, June 2-4, 2003 Proceedings, p.120 - 129, 2003/00
Information-Technology Based Laboratory (ITBL) project has been propelled as one of e-Japan priority policy programs. The purposes of the project are to share intellectual resources such as remote computers, programs and data in universities and institutes and to support cooperative studies among researchers, building a virtual research environment, ITBL. Japan Atomic Energy Research Institute (JAERI) has been working on installation and management of hardware and development of infrastructure software and applications. As application software, researches on quantum bioinformatics and environmental sciences are carried out. This paper presents utilization of ITBL system infra-structure software for 'Numerical Environment System' which is developed for environmental studies. More effective job executions and visualization are ex-pected by using Task Mapping Editor (TME) and AVS/ITBL, which are tools developed as infrastructure software.
Kobayashi, Takuya; Nagai, Haruyasu; Chino, Masamichi; Togawa, Orihiko
Proceedings of International Symposium on Radioecology and Environmental Dosimetry, p.500 - 504, 2003/00
The possibility of radionuclide release to the environment is on the increase due to a growth of nuclear facilities in Asia, military problems, nuclear terrorism, etc. The released radionuclides circulate among the atmospheric, oceanic and terrestrial environment, influencing human and natural environment through complex processes. In order to reduce the damage from these pollutants, it is necessary to estimate their migration behavior in detail. A software system SPEEDI-MP (SPEEDI Multi-model Package) is under development to resolve such environmental problems by simulating the 'inclusive and successive' behavior of pollutants in the atmospheric, oceanic and terrestrial environment. As code verification, the system has been applied to a hypothetical accident of a nuclear submarine if it sinks in an offshore region around Japan. The predicted results are examined, and the applicability and validity of the system are discussed.
Kobayashi, Takuya; Lee, S.; Chino, Masamichi
Journal of Nuclear Science and Technology, 39(2), p.171 - 179, 2002/02
Times Cited Count：3 Percentile：22.53(Nuclear Science & Technology)A three-dimensional model system was developed to predict oceanic dispersions of radionuclides released into the eastern area of Shimokita Peninsula. This system is a combination of the Princeton Ocean Model (POM) for predicting ocean currents and a particle random walk model for oceanic dispersion of radionuclides. The model was verified by using measured currents, temperature and salinity at the coastal area of Shimokita, Aomori-ken, Japan, where a nuclear fuel reprocessing plant is under construction. The results obtained from simulations area as follows; (1) Wind and the Tsugaru Warm Current entering into the objective region through the Tsugaru Strait significantly affect the structure of current over the region. (2) POM can represent seasonal variations of the Tsugaru Warm Current well with hypothetical oceanographic data. The calculation succeeded to reproduce the coastal mode from winter to spring and the gyre mode from summer to autumn.
Kobayashi, Takuya; Lee, S.; Chino, Masamichi
Proceedings of 4th International Conference on Supercomputing in Nuclear Applications (SNA 2000) (CD-ROM), 9 Pages, 2000/09
no abstracts in English
Kobayashi, Masamichi*; Yoshioka, Toshimori*; Kozasa, Takehiko*; Tashiro, Koji*; Suzuki, Junichi; Funahashi, Satoru; Izumi, Yoshinobu*
Macromolecules, 27(6), p.1349 - 1354, 1994/00
Times Cited Count：46 Percentile：85.76(Polymer Science)no abstracts in English
Yokobori, Shinichi*; Yang, Y.*; Fujisaki, Kenta*; Kawaguchi, Yuko*; Hashimoto, Hirofumi*; Yamashita, Masamichi*; Yano, Hajime*; Okudaira, Kyoko*; Yoshimura, Yoshitaka*; Narumi, Issei; et al.
no journal, ,
no abstracts in English
Yokobori, Shinichi*; Fujisaki, Kenta*; Kawaguchi, Yuko*; Yang, Y.*; Fushimi, Hidehiko*; Hashimoto, Hirofumi*; Yamashita, Masamichi*; Yano, Hajime*; Okudaira, Kyoko*; Hayashi, Nobuhiro*; et al.
no journal, ,
no abstracts in English
Yokobori, Shinichi*; Yang, Y.*; Kawaguchi, Yuko*; Sugino, Tomohiro*; Takahashi, Yuta*; Narumi, Issei; Takahashi, Yuichi*; Hayashi, Nobuhiro*; Yoshimura, Yoshitaka*; Tabata, Makoto*; et al.
no journal, ,
no abstracts in English
Sugino, Tomohiro*; Yokobori, Shinichi*; Yang, Y.*; Kawaguchi, Yuko*; Hasegawa, Sunao*; Hashimoto, Hirofumi*; Imai, Eiichi*; Okudaira, Kyoko*; Kawai, Hideyuki*; Tabata, Makoto*; et al.
no journal, ,
Yokobori, Shinichi*; Yang, Y.*; Sugino, Tomohiro*; Kawaguchi, Yuko*; Takahashi, Yuta*; Narumi, Issei; Hashimoto, Hirofumi*; Hayashi, Nobuhiro*; Imai, Eiichi*; Kawai, Hideyuki*; et al.
no journal, ,
Yokobori, Shinichi*; Yang, Y.*; Kawaguchi, Yuko*; Sugino, Tomohiro*; Takahashi, Yuta*; Narumi, Issei; Nakagawa, Kazumichi*; Tabata, Makoto*; Kobayashi, Kensei*; Marumo, Katsumi*; et al.
no journal, ,
Kobayashi, Takuya; Nagai, Haruyasu; Chino, Masamichi; Kawamura, Hideyuki
no journal, ,
The source term of the atmospheric release of I-131 and Cs-137 due to the Fukushima Dai-ichi Nuclear Power Plant accident estimated by previous studies was validated and refined by coupling atmospheric and oceanic dispersion simulations with observed Cs-134 in seawater collected from the Pacific Ocean.
Kobayashi, Takuya; Kawamura, Hideyuki; Nagai, Haruyasu; Chino, Masamichi
no journal, ,
no abstracts in English
As via high-resolution inelastic X-ray scatteringMurai, Naoki; Fukuda, Tatsuo; Kobayashi, Tatsuya*; Nakajima, Masamichi*; Uchiyama, Hiroshi*; Ishikawa, Daisuke*; Tsutsui, Satoshi*; Nakamura, Hiroki; Machida, Masahiko; Miyasaka, Shigeki*; et al.
no journal, ,
We report the first IXS study of single crystals of SrFeAs that have been detwinned via application of in-plane uniaxial stress. Our results clearly show anisotropy in phonon structure below 
= 
characterized by mode splitting at tetragonally-equivalent momentum transfers. To the best of our knowledge, this is the first observation of phonon anisotropy in iron-pnictides at finite momentum transfers. We obtain good agreement with our results using calculations that are modified to account for a reduced magnetic moment and fluctuating magnetism. Previous efforts using either non-magnetic calculations or static magnetism tend to either get the dispersion wrong from non-magnetic calculations or strongly over-estimate the phonon mode splitting when static magnetism is included. Our model for the response below incorporates a phenomenological reduction in force constant anisotropy, by about 65%, that can be attributed to residual fast magnetic fluctuations. Above , all fluctuations are assumed to be fast and the response becomes the average of the results from the static magnetism. This serves as a starting point for a general model of phonons in iron-pnictides applicable to both non-magnetic and magnetic phases.
