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Journal Articles

Validation of ATDMs at early after the lF accident using air dose rate estimated by airborne concentration and surface deposition density

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

Journal Articles

A Model intercomparison of atmospheric $$^{137}$$Cs concentrations from the Fukushima Daiichi Nuclear Power Plant accident, phase III; Simulation with an identical source term and meteorological field at 1-km resolution

Sato, Yosuke*; Sekiyama, Tsuyoshi*; Fang, S.*; Kajino, Mizuo*; Qu$'e$rel, A.*; Qu$'e$lo, 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 $$^{137}$$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 $$^{137}$$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.

Journal Articles

Proton chelating ligands drive improved chemical separations for rhodium

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:20 Percentile:75.87(Chemistry, Inorganic & Nuclear)

Journal Articles

Electrochemical Cs removal and crystal formation from Fukushima weathered biotite in molten NaCl-CaCl$$_{2}$$

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$$_{2}$$ 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$$^{3+}$$ and Fe$$^{2+}$$. After EC treatment, the presence of Fe$$^{2+}$$ was confirmed by XAFS analysis. Based on this finding, EC treatment is effective for reducing Fe in WB. This result indicated that Fe$$_{2}$$O$$_{3}$$ formation was suppressed, and the reduction reaction was effective for controlling crystal formation.

Journal Articles

Model intercomparison of atmospheric $$^{137}$$Cs from the Fukushima Daiichi Nuclear Power Plant accident; Simulations based on identical input data

Sato, Yosuke*; Takigawa, Masayuki*; Sekiyama, Tsuyoshi*; Kajino, Mizuo*; Terada, Hiroaki; Nagai, Haruyasu; Kondo, Hiroaki*; Uchida, Junya*; Goto, Daisuke*; Qu$'e$lo, D.*; et al.

Journal of Geophysical Research; Atmospheres, 123(20), p.11748 - 11765, 2018/10

 Times Cited Count:48 Percentile:84.77(Meteorology & Atmospheric Sciences)

A model intercomparison of the atmospheric dispersion of $$^{137}$$Cs emitted following the Fukushima Daiichi Nuclear Power Plant accident was conducted by 12 models to understand the behavior of $$^{137}$$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 $$^{137}$$Cs events, and the figure-of-merit in space for the total deposition of $$^{137}$$Cs exceeded 80. Our analyses indicated that the meteorological data were most critical for reproducing the $$^{137}$$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 $$^{137}$$Cs concentrations.

Journal Articles

New strategy to enhance catalytic performance of ${it Escherichia coli}$ whole cell biocatalysts harboring P450cam mutants

Mouri, Tsuyoshi; Kamiya, Noriho*; Goto, Masahiro*

Biochemical Engineering Journal, 53(2), p.229 - 233, 2011/01

 Times Cited Count:5 Percentile:20.08(Biotechnology & Applied Microbiology)

In this paper, we have developed a new ${it Escherichia coli}$ 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 ${it E. coli}$ whole-cell biocatalysts might be applicable to practical microbial indigo production.

Journal Articles

Fault-related features and restoration of fault slips revealed by airborne laser imagery along the Senya fault and Adera fault

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.

Journal Articles

Studies of fast-ion transport induced by energetic particle modes using fast-particle diagnostics with high time resolution in CHS

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:69.07(Physics, Fluids & Plasmas)

no abstracts in English

Journal Articles

Magnetic-field-induced transition in the lattice modulation of colossal magnetoelectric GdMnO$$_3$$ and TbMnO$$_3$$ compounds

Arima, 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:95.37(Materials Science, Multidisciplinary)

Single-crystal synchrotron X-ray diffraction measurements in strong magnetic fields have been performed for magnetoelectric compounds GdMnO$$_3$$ and TbMnO$$_3$$. It has been found that the ${bf P}$//a ferroelectric phase induced by the application of a magnetic field at low temperatures is characterized by commensurate lattice modulation along the orthorhombic ${it b}$ 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 ${it a}$ axis of the distorted perovskite with the space group.

Journal Articles

Fluoride complexation of element 104, rutherfordium

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:72.46(Chemistry, Multidisciplinary)

Fluoride complexation of element 104, rutherfordium (Rf), produced in the $$^{248}$$Cm($$^{18}$$O,5n)$$^{261}$$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 $$^{18}$$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.

Journal Articles

Chemical studies of the heaviest elements

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:56.34(Physics, Nuclear)

no abstracts in English

Oral presentation

Cesium removal and separate from Fukushima weathered biotite using molten salt electrochemistry

Honda, Mitsunori; Goto, Takuya*; Sakanaka, Yoshihide*; Shimoyama, Iwao; Okamoto, Yoshihiro; Suzuki, Shinichi; Yaita, Tsuyoshi

no journal, , 

no abstracts in English

Oral presentation

Model intercomparison study for atmospheric $$^{137}$$Cs from the Fukushima Daiichi Nuclear Power Plant Accident using identical input data

Sato, Yosuke*; Takigawa, Masayuki*; Sekiyama, Tsuyoshi*; Kajino, Mizuo*; Terada, Hiroaki; Nagai, Haruyasu; Kondo, Hiroaki*; Uchida, Junya*; Goto, Daisuke*; Qu$'e$lo, D.*; et al.

no journal, , 

An intercomparison of atmospheric dispersion model targeting on the physical process of $$^{137}$$Cs released from the Fukushima Daiichi Nuclear Power Plant was conducted. Twelve atmospheric models participated in this project. To exclude the uncertainties of the model result due to the emission inventory and meteorological data, all models used the same emission and meteorological data. Concentration of $$^{137}$$Cs from the national suspended particle matter monitoring network and the deposition density by the aircraft were used for the comparison between results of the model and observation. Our analyses elucidated the figure of merit in space (FMS) of the model ensemble mean was improved from a previous model intercomparson about the accumulated deposition. The model ensemble mean captured approximately 36% of the observed high concentration. The inter-model spread of the capture rate was from 8% to 38%. It was originated from the difference in deposition and diffusion processes among the models.

Oral presentation

Cesium removal and separate from Fukushima weathered biotite using molten salt electrochemistry

Honda, Mitsunori; Goto, Takuya*; Sakanaka, Yoshihide*; Shimoyama, Iwao; Okamoto, Yoshihiro; Suzuki, Shinichi; Yaita, Tsuyoshi

no journal, , 

no abstracts in English

Oral presentation

Construction of cytochrome P450BM3 oxidation reaction system linked by cofactor regeneration

Mouri, Tsuyoshi; Kamiya, Noriho*; Goto, Masahiro*

no journal, , 

no abstracts in English

Oral presentation

Construction of cytochrome P450BM3 reaction system using STH/GLD cofactor regeneration

Mouri, Tsuyoshi; Kamiya, Noriho*; Goto, Masahiro*

no journal, , 

no abstracts in English

Oral presentation

2nd atmospheric model intercomparison project for Fukushima Daiichi Nuclear Power Plant Accident on March 2011; 2nd FDNPP-MIP

Sato, Yosuke*; Takigawa, Masayuki*; Sekiyama, Tsuyoshi*; Kajino, Mizuo*; Grahn, H.*; Br$"a$nnstr$"o$m, N.*; von Schoenberg, P.*; Kondo, Hiroaki*; Terada, Hiroaki; Nagai, Haruyasu; et al.

no journal, , 

The second intercomparison of atmospheric model targeting on the radionuclide (i.e. $$^{137}$$Cs) released from the Fukushima Daiichi Nuclear Power Plant (FDNPP) on March 2011 is conducted. Thirteen atmospheric models, which include both the Lagrangian- and Eulerian-based dispersion models, participate in this model intercomparison project (MIP). The purposes of this MIP are to (1) understand the transport process of the radionuclide in atmosphere, (2) estimate the uncertainties in wet and dry deposition process among the models, (3) reveal the essential key processes to reproduce the plume of $$^{137}$$Cs, (4) assess the multi-model ensemble mean, and (5) obtain the knowledge for improving the physical processes of the models. To exclude the uncertainties of the model results originated from the emission inventory, all models used the same emission inventory. The meteorological data with fine spatiotemporal resolution, which was calculated by the Japanese operational weather forecast model coupled with the local ensemble transform Kalman Filter data assimilation system, was applied for all models to reduce the uncertainties originated from the difference in the meteorological field. As well as the comparison among the models, the comparison between the models and in-situ measurement from the national suspended particle matter (SPM) sampling network are conducted. The comparisons between the model results and the SPM data indicate that the $$^{137}$$Cs concentration near the FDNPP transported without precipitation process was relatively well reproduced by using the meteorological data with fine spatiotemporal resolution. On the contrary, $$^{137}$$Cs concentration accompanied with precipitation has large inter-model spread. In the presentation, we will discuss the more detailed analyses about the physical process to determine the $$^{137}$$Cs concentration.

Oral presentation

Adsorption of element-105 (Db) on anion-exchange resin in HF/HNO$$_{3}$$ solutions

Kasamatsu, Yoshitaka; Toyoshima, Atsushi; Asai, Masato; Tsukada, Kazuaki; Haba, Hiromitsu*; Ishii, Yasuo; Tome, Hayato; Nishinaka, Ichiro; Akiyama, Kazuhiko*; Kikunaga, Hidetoshi*; et al.

no journal, , 

Dubnium-262 was produced in the nuclear reaction of $$^{248}$$Cm($$^{19}$$F,5n)$$^{262}$$Db using the JAEA Tandem accelerator. The reaction products were rapidly transported to the chemistry laboratory and the anion-exchange behavior of Db in HF/HNO$$_{3}$$ media was investigated with an on-line rapid ion-exchange apparatus. Based on the comparison of the behavior of Db with that of its homologues (Nb, Ta, and Pa), the fluoride complex formation of Db was discussed.

Oral presentation

Investigation of thermoelectric materials for low environmental load by molten salt electrochemistry based on soil clay minerals

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.

Oral presentation

Anion-exchange behavior of element 105, Db, in HF/HNO$$_{3}$$ media

Kasamatsu, Yoshitaka; Toyoshima, Atsushi; Asai, Masato; Tsukada, Kazuaki; Haba, Hiromitsu*; Ishii, Yasuo; Tome, Hayato; Nishinaka, Ichiro; Akiyama, Kazuhiko*; Kikunaga, Hidetoshi*; et al.

no journal, , 

Dubnium-262 was produced in the $$^{248}$$Cm($$^{19}$$F, 5${it n}$) reaction at the JAEA tandem accelerator. Adsorption of Db on the anion-exchange resin was investigated in 0.89 M HF/0.3 M HNO$$_{3}$$ solution. The anion-exchange behavior of Nb, Ta, and Pa as homologues of Db was also examined in details in HF/HNO$$_{3}$$ solutions. From the comparison of those results, we found that the adsorption of Db on the anion-exchange resin is considerably weaker than that of Ta and is relatively similar to those of Nb and Pa in the studied conditions.

50 (Records 1-20 displayed on this page)