Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Arai, Yoichi; Goto, Yasuhiro; Watanabe, So; Agou, Tomohiro*; Arai, Tsuyoshi*; Katsuki, Kenta*; Fukumoto, Hiroki*; Hoshina, Hiroyuki*; Seko, Noriaki*
Progress in Nuclear Science and Technology (Internet), 8, p.329 - 332, 2025/09
Moriguchi, Yuichi*; Sato, Yosuke*; Morino, Yu*; Goto, Daisuke*; Sekiyama, Tsuyoshi*; Terada, Hiroaki; Takigawa, Masayuki*; Tsuruta, Haruo*; Yamazawa, Hiromi*
KEK Proceedings 2021-2, p.21 - 27, 2021/12
no abstracts in English
Cs concentrations from the Fukushima Daiichi Nuclear Power Plant accident, phase III; Simulation with an identical source term and meteorological field at 1-km resolutionSato, Yosuke*; Sekiyama, Tsuyoshi*; Fang, S.*; Kajino, Mizuo*; Qu
rel, A.*; Qulo, D.*; Kondo, Hiroaki*; Terada, Hiroaki; Kadowaki, Masanao; Takigawa, Masayuki*; et al.
Atmospheric Environment; X (Internet), 7, p.100086_1 - 100086_12, 2020/10
The third model intercomparison project for investigating the atmospheric behavior of Cs emitted during the Fukushima Daiichi Nuclear Power Plant (FDNPP) accident (FDNPP-MIP) was conducted. A finer horizontal grid spacing (1 km) was used than in the previous FDNPP-MIP. Nine of the models used in the previous FDNPP-MIP were also used, and all models used identical source terms and meteorological fields. Our analyses indicated that most of the observed high atmospheric Cs concentrations were well simulated, and the good performance of some models improved the performance of the multi-model ensemble. The analyses also confirmed that the use of a finer grid resolution resulted in the meteorological field near FDNPP being better reproduced. The good representation of the wind field resulted in the reasonable simulation of the narrow distribution of high deposition amount to the northwest of FDNPP and the reduction of the overestimation over the area to the south of FDNPP. In contrast, the performance of the models in simulating plumes observed over the Nakadori area, the northern part of Gunma, and the Tokyo metropolitan area was slightly worse.
Narita, Hirokazu*; Nicolson, R. M.*; Motokawa, Ryuhei; Ito, Fumiyuki*; Morisaku, Kazuko*; Goto, Midori*; Tanaka, Mikiya*; Heller, W. T.*; Shiwaku, Hideaki; Yaita, Tsuyoshi; et al.
Inorganic Chemistry, 58(13), p.8720 - 8734, 2019/07
Times Cited Count：22 Percentile：76.84(Chemistry, Inorganic & Nuclear)
Honda, Mitsunori; Goto, Takuya*; Sakanaka, Yoshihide*; Yaita, Tsuyoshi; Suzuki, Shinichi*
AIMS Electronics and Electrical Engineering (Internet), 3(2), p.102 - 110, 2019/03
The possibility of removal and controlling crystal formation from weathered biotite (WB) in clay minerals were investigated using molten salt electrochemistry (EC) in molten NaCl-CaCl under an electrochemical reductive reaction. Cyclic Voltammogram (CV) measurements were performed in the range of +0.5 V to -2.2 V. Several peaks were confirmed in the CV spectra. The peak at -1.4 V represents a reduction reaction of Fe in WB, so we conducted an experiment at -1.4 V for 2 h to reduce Iron (Fe). The Cs removal rate after EC treatment was determined by X-ray fluorescence analysis, and almost 100% Cs removal was confirmed. To understand the effect of the reductive reaction, we performed X-ray Adsorption Fine Structure (XAFS) analysis. Before EC treatment, the Fe in WB was present as a mixture of Fe
and Fe
. After EC treatment, the presence of Fe was confirmed by XAFS analysis. Based on this finding, EC treatment is effective for reducing Fe in WB. This result indicated that FeO
formation was suppressed, and the reduction reaction was effective for controlling crystal formation.
Cs from the Fukushima Daiichi Nuclear Power Plant accident; Simulations based on identical input dataSato, Yosuke*; Takigawa, Masayuki*; Sekiyama, Tsuyoshi*; Kajino, Mizuo*; Terada, Hiroaki; Nagai, Haruyasu; Kondo, Hiroaki*; Uchida, Junya*; Goto, Daisuke*; Qulo, D.*; et al.
Journal of Geophysical Research; Atmospheres, 123(20), p.11748 - 11765, 2018/10
Times Cited Count：51 Percentile：84.89(Meteorology & Atmospheric Sciences)A model intercomparison of the atmospheric dispersion of Cs emitted following the Fukushima Daiichi Nuclear Power Plant accident was conducted by 12 models to understand the behavior of Cs in the atmosphere. The same meteorological data, horizontal grid resolution, and an emission inventory were applied to all the models to focus on the model variability originating from the processes included in each model. The multi-model ensemble captured 40% of the observed Cs events, and the figure-of-merit in space for the total deposition of Cs exceeded 80. Our analyses indicated that the meteorological data were most critical for reproducing the Cs events. The results also revealed that the differences among the models were originated from the deposition and diffusion processes when the meteorological field was simulated well. However, the models with strong diffusion tended to overestimate the Cs concentrations.
whole cell biocatalysts harboring P450cam mutantsMouri, Tsuyoshi; Kamiya, Noriho*; Goto, Masahiro*
Biochemical Engineering Journal, 53(2), p.229 - 233, 2011/01
Times Cited Count：5 Percentile：19.75(Biotechnology & Applied Microbiology)In this paper, we have developed a new whole-cell biocatalytic system that affords the efficient microbial indigo production by cytochrome P450cam mutants (Y96F or F87W-Y96F) in the cells. The novel system is comprised of two types of P450cam mutants (Y96F or F87W-Y96F), putidaredoxin, putidaredoxin reductase, and bacterial glycerol dehydrogenase. The present 
whole-cell biocatalysts might be applicable to practical microbial indigo production.
Nakata, Takashi*; Kumamoto, Takashi*; Okumura, Koji*; Goto, Hideaki*; Kumahara, Yasuhiro*; Nohara, Tsuyoshi; Sato, Masaru*; Iwanaga, Shoji*
Katsudanso Kenkyu, (29), p.1 - 13, 2008/09
Laser imagery technique is applied to obtain comprehensive features of typical reverse fault (Senya fault in NE Japan) and strike-slip fault (Adera fault in Central Japan). We test several methods for obtaining fault slip from detailed DEM images. Using the visual analyzer "Geo-Graphia", several three-dimensional laser imageries are processed around Senya hill, especially along the surface fault ruptures associated with 1896 Rikuu earthquake. We compared amount of fault slips along the fault ruptures measured by field work (Matsuda et al., 1980) with that obtained by automatic and manual profiling using detailed DEM. Three-dimensional laser imageries are also processed along Adera fault, and slip vectors are restored based on successively faulted terrace risers around Sakashita town.
Isobe, Mitsutaka*; Toi, Kazuo*; Matsushita, Hiroyuki*; Goto, Kazuyuki*; Suzuki, Chihiro*; Nagaoka, Kenichi*; Nakajima, Noriyoshi*; Yamamoto, Satoshi*; Murakami, Sadayoshi*; Shimizu, Akihiro*; et al.
Nuclear Fusion, 46(10), p.S918 - S925, 2006/10
Times Cited Count：31 Percentile：69.62(Physics, Fluids & Plasmas)no abstracts in English
and TbMnO compoundsArima, Takahisa*; Goto, Tsuyoshi*; Yamazaki, Yuichi*; Miyasaka, Shigeki*; Ishii, Kenji; Tsubota, Masami; Inami, Toshiya; Murakami, Yoichi*; Tokura, Yoshinori*
Physical Review B, 72(10), p.100102_1 - 100102_4, 2005/09
Times Cited Count：132 Percentile：95.24(Materials Science, Multidisciplinary)Single-crystal synchrotron X-ray diffraction measurements in strong magnetic fields have been performed for magnetoelectric compounds GdMnO and TbMnO. It has been found that the 
//a ferroelectric phase induced by the application of a magnetic field at low temperatures is characterized by commensurate lattice modulation along the orthorhombic 
axis with q=1/2 and q=1/4. The lattice modulation is ascribed to antiferromagnetic spin alignment with a modulation vector of (0 1/4 1). The change of the spin structure is directly correlated with the magnetic-field-induced electric phase transition, because any commensurate spin modulation with (0 1/4 1) should break glide planes normal to the 
axis of the distorted perovskite with the space group.
Haba, Hiromitsu*; Tsukada, Kazuaki; Asai, Masato; Toyoshima, Atsushi; Akiyama, Kazuhiko; Nishinaka, Ichiro; Hirata, Masaru; Yaita, Tsuyoshi; Ichikawa, Shinichi; Nagame, Yuichiro; et al.
Journal of the American Chemical Society, 126(16), p.5219 - 5224, 2004/04
Times Cited Count：44 Percentile：72.22(Chemistry, Multidisciplinary)Fluoride complexation of element 104, rutherfordium (Rf), produced in the 
Cm(
O,5n)
Rf reaction has been studied by anion-exchange chromatography on an atom-at-a-time scale. The anion-exchangechromatographic behavior of Rf was investigated in 1.9-13.9 M hydrofluoric acid together with those of the group-4 elements Zr and Hf produced in the O-induced reactions on Ge and Gd targets, respectively. It was found that the adsorption behavior of Rf on anion-exchange resin is quite different from those of Zr and Hf, suggesting the influence of relativistic effect on the fluoride complexation of Rf.
Nagame, Yuichiro; Haba, Hiromitsu*; Tsukada, Kazuaki; Asai, Masato; Toyoshima, Atsushi; Goto, Shinichi*; Akiyama, Kazuhiko; Kaneko, Tetsuya; Sakama, Minoru*; Hirata, Masaru; et al.
Nuclear Physics A, 734, p.124 - 135, 2004/04
Times Cited Count：11 Percentile：55.96(Physics, Nuclear)no abstracts in English
Yamazawa, Hiromi*; Oura, Yasuji*; Moriguchi, Yuichi*; Terada, Hiroaki; Sekiyama, Tsuyoshi*; Goto, Daisuke*; Tsuruta, Haruo*
no journal, ,
no abstracts in English
Cs) from the Fukushima Daiichi Nuclear Power Station Accident using identical meteorological data and source termSato, Yosuke*; Takigawa, Masayuki*; Sekiyama, Tsuyoshi*; Kajino, Mizuo*; Terada, Hiroaki; Nagai, Haruyasu; Kondo, Hiroaki*; Uchida, Junya*; Goto, Daisuke*; Qulo, D.*; et al.
no journal, ,
no abstracts in English
Yamazawa, Hiromi*; Sato, Yosuke*; Adachi, Shinichiro*; Takigawa, Masayuki*; Sekiyama, Tsuyoshi*; Kajino, Mizuo*; Terada, Hiroaki; Kondo, Hiroaki*; Uchida, Junya*; Goto, Daisuke*; et al.
no journal, ,
Cs-137 released from the Fukushima Daiichi Nuclear Power Plant (FDNPP) accident was conducted by 12 models. The present study focuses on differences in the model results of atmospheric Cs-137 concentration of Plume 2, which traveled southward in the morning of 15 March, 2011, in the area 100 to 200 km downwind from FDNPP by using the concentration data recently evaluated from gamma radiation spectral data at monitoring stations (MS data) and those measured from the suspended particulate matter filters (SPM data). Comparison was made from the following aspects: (1) plume arrival time, (2) concentration level, (3) cross-wind surface concentration profile, (4) vertical concentration profile and (5) mass balance of Cs-137 activity including deposition processes. Additional analyses were made also for Plume 4, which traveled over the same area on 16 March under rainy condition.
Honda, Mitsunori; Goto, Takuya*; Kaneta, Yui; Yaita, Tsuyoshi
no journal, ,
We have been investigating the restoration of the environment in Fukushima. One of the issues to be solved is the removal of cesium from the soil of Fukushima. As we studied the technology to remove cesium from the soil of Fukushima, we thought that the reclamation could be accelerated by adding new functions (e.g., thermoelectric properties) to the clay minerals after removal. Soil clay minerals are composed of Si, Al, Fe, etc., and are low environmental load materials. Soil clay minerals were reduced by molten salt electrochemistry and their properties were investigated. Thermal diffusivity measurements showed no temperature dependence in the untreated sample, while the temperature dependence was significantly different in the case of -1.4 V molten salt electrolysis treatment.
Cs emitted from Fukushima Daiichi Nuclear Power Plant, and application of MIPs' results for usage in an emergencyYamazawa, Hiromi*; Sato, Yosuke*; Sekiyama, Tsuyoshi*; Kajino, Mizuo*; Fang, S.*; Qurel, A.*; Qulo, D.*; Kondo, Hiroaki*; Terada, Hiroaki; Kadowaki, Masanao; et al.
no journal, ,
The 3rd model intercomparison project (MIP) of atmospheric dispersion model targeting on Cs emitted from Fukushima Daiichi Nuclear Power Plant (FDNPP) in March 2011 were conducted. All participated 9 models used the identical source term and meteorological data as in the previous MIP (2nd MIP), but finer horizontal grid resolution (1 km) than that of 2nd MIP (3 km) was used for understanding the behavior of atmospheric Cs in the vicinity of FDNPP. Results of the models elucidated that most of the observed high atmospheric Cs concentrations were well simulated, and the good performance of some models cancelled bad performance of some models when used as an ensemble, which highlights the advantage of multimodel ensemble. The analyses also indicated that the use of the finer grid resolution improved the meteorological field in the vicinity of FNDPP and the atmospheric Cs measured near FDNPP was more reasonably reproduced in 3rd MIP than 2nd MIP. As well as the evaluation of the performance of the model, we examined usefulness of the results of atmospheric dispersion simulation in an emergency. The analyses reported that the multimodel ensemble missed only 3% of the observed plumes, even if the absolute value of the simulated Cs in each model was different in the range of factor 3-6. The analyses also indicated that from six to eight models are required for making most of advantages of the multimodel ensemble.
Yamazawa, Hiromi*; Oura, Yasuji*; Moriguchi, Yuichi*; Terada, Hiroaki; Sekiyama, Tsuyoshi*; Goto, Daisuke*; Tsuruta, Haruo*; Sato, Yosuke*
no journal, ,
no abstracts in English
Honda, Mitsunori; Kaneta, Yui; Muraguchi, Masakazu*; Hayakawa, Kosetsu*; Oda, Masato*; Iino, Chiaki*; Ishii, Hiroyuki*; Goto, Takuya*; Yaita, Tsuyoshi
no journal, ,
Twelve years have passed since the 1F accident that occurred in 2011, and contaminated soil generated in Fukushima Prefecture is being managed as removed soil. We have focused on the functionality of several crystalline minerals obtained in the process of developing a technology to remove Cs from the removed soil, and are examining their potential as thermoelectric conversion materials. In this study, we report on the evaluation of thermoelectric properties (electrical conductivity, thermal diffusivity, and Seebeck coefficient) of the crystalline minerals.
Honda, Mitsunori; Kaneta, Yui; Hayakawa, Kosetsu*; Muraguchi, Masakazu*; Iino, Chiaki*; Oda, Masato*; Ishii, Hiroyuki*; Goto, Takuya*; Yaita, Tsuyoshi
no journal, ,
In this study, thermoelectric properties (electrical conductivity, Seebeck coefficient, and thermal diffusivity) were evaluated (OZMA-1-S1) for polycrystalline minerals obtained by systematically changing the conditions of WB and the molten treatment. The Seebeck coefficient and thermal diffusivity were evaluated on the same sample. Macroscopic and microscopic structures were identified by various X-ray analyses and first-principles calculations. As for the electrical conductivity results of WB, the biotite material is usually known as an electrical insulator at room temperature, but after grinding, classification, molten salt treatment, and sintering, it was found to have electrical conductivity on the order of 1.49 
10
(
V/K) in the temperature range 650-850
C, indicating that it has semiconducting electrical conductivity properties. Seebeck coefficient measurements in the same temperature range showed a high value of -2.010
(V/K). Calculating the dimensionless performance index 
from the obtained results, =0.29 was obtained. Regarding the thermoelectric property evaluation results for the molten salt treated polycrystalline minerals, higher electrical conductivity properties than WB were obtained for the same temperature range. These results suggest that WB can be used to show useful thermoelectric properties in the high temperature region above 650C.
