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Mishima, Ria; Inaba, Yusuke*; Tachioka, Sotaro*; Harigai, Miki*; Watanabe, Shinta*; Onoe, Jun*; Nakase, Masahiko*; Matsumura, Tatsuro; Takeshita, Kenji*
Chemistry Letters, 49(1), p.83 - 86, 2020/01
Times Cited Count：4 Percentile：21.18(Chemistry, Multidisciplinary)Separation of platinum group metals (PGMs) from high-level liquid waste generated from the reprocessing of spent nuclear fuels is important to produce good quality vitrified glass for final disposal. A new sorbent, Aluminum hexacyanoferrate (AlHCF), was synthesized and the general sorption behavior of PGMs from concentrated nitric acid was examined. Nitric acid caused substantial elution of AlHCF but the sorption of Pd stabilized the structure. Consequently, Rh was sorbed in the presence of Pd, whereas single Rh sorption caused complete dissolution of AlHCF. Relation between sorbed mount of Pd vs eluted Al and Fe revealed that the elution ratio of Al and Fe was not the same as molar ratio of synthesized AlHCF, indicating the re-sorption of Fe resulted in formation of new structure. The sorption mechanism of PGMs by this new sorbent, AlHCF, not only the simple ion exchange, but also oxidation reduction reaction as well as kinetics play important rule. Understanding the general sorption and dissolution behavior will help improve the sorption performance of PGMs by AlHCF.
-P adsorbent for MA(III) recoveryKofuji, Hirohide; Watanabe, So; Takeuchi, Masayuki; Suzuki, Hideya; Matsumura, Tatsuro; Shiwaku, Hideaki; Yaita, Tsuyoshi
Progress in Nuclear Science and Technology (Internet), 5, p.61 - 65, 2018/11
Watanabe, So; Suzuki, Hideya; Goto, Ichiro*; Kofuji, Hirohide; Matsumura, Tatsuro
Nihon Ion Kokan Gakkai-Shi, 29(3), p.71 - 75, 2018/09
Kaneko, Masashi; Watanabe, Masayuki; Matsumura, Tatsuro
Dalton Transactions, 45(43), p.17530 - 17537, 2016/11
Times Cited Count：33 Percentile：87.63(Chemistry, Inorganic & Nuclear)Relativistic density functional calculations were applied to study the separation behaviors of Am(III) ion from Eu(III) ion by diglycolamide (DGA) and nitrilotriacetamide (NTA) ligands in order to understand the difference in the separation mechanism of their reagents. The complexation reaction was modeled on the basis of previous experimental studies. The calculated energies based on stabilization by complex formation at the ZORA-B2PLYP/SARC level predicted that the DGA reagent preferably coordinated to Eu(III) ion when compared with Am(III) ion. In contrast, the NTA reagent selectively coordinated to Am(III) ion when compared with Eu(III) ion. These results reproduced the experimental selectivity of DGA and NTA ligands toward Eu(III) and Am(III) ions. Mulliken's population analyses implied that the difference in the contribution of the bonding property between the f-orbital of Am and donor atoms determined the comparative stability of Eu and Am complexes.
Inaba, Yusuke*; Tsumagari, Takayuki*; Kida, Tatsuya*; Watanabe, Wataru*; Nakajima, Yasutaka*; Fukuoka, Sachio*; Mori, Atsunori*; Matsumura, Tatsuro; Nakano, Yoshio*; Takeshita, Kenji*
Polymer Journal, 43(7), p.630 - 634, 2011/07
Times Cited Count：11 Percentile：35.53(Polymer Science)
-(tetrakis-2-pyridylmethyl)ethylenediamine (TPEN) derivatives bearing a polymerizable double bond in the substituent structure of the pyridine ring are synthesized and subjected to copolymerization with 
-isopropylacrylamide in the presence of AIBN. The obtained poly(TPEN-NIPA) gels show thermo-responsive swelling/shrinking behaviors and are employed for the extraction of cadmium(II) ion from the aqueous solution to examine the relationship of the gel characteristics and the extraction performance. The polymer gels composed of the TPEN derivative bearing C3, C4, C10 and branched C3 spacer chains are synthesized and temperature-dependent extraction behavior of cadmium ion is compared. These gels extract Cd(II) ion efficiently from the aqueous solution in the swelling state at 5
C, while little extraction is observed at 45C with shrinking. It is found that poly(TPEN-NIPA) gel of branched C3 spacer (C3b) shows the excellent thermoresponsive extraction performance.
Sakanaka, Shogo*; Akemoto, Mitsuo*; Aoto, Tomohiro*; Arakawa, Dai*; Asaoka, Seiji*; Enomoto, Atsushi*; Fukuda, Shigeki*; Furukawa, Kazuro*; Furuya, Takaaki*; Haga, Kaiichi*; et al.
Proceedings of 1st International Particle Accelerator Conference (IPAC '10) (Internet), p.2338 - 2340, 2010/05
Future synchrotron light source using a 5-GeV energy recovery linac (ERL) is under proposal by our Japanese collaboration team, and we are conducting R&D efforts for that. We are developing high-brightness DC photocathode guns, two types of cryomodules for both injector and main superconducting (SC) linacs, and 1.3 GHz high CW-power RF sources. We are also constructing the Compact ERL (cERL) for demonstrating the recirculation of low-emittance, high-current beams using above-mentioned critical technologies.
Fukuoka, Sachio*; Kida, Tatsuya*; Nakajima, Yasutaka*; Tsumagari, Takayuki*; Watanabe, Wataru*; Inaba, Yusuke*; Mori, Atsunori*; Matsumura, Tatsuro; Nakano, Yoshio*; Takeshita, Kenji*
Tetrahedron, 66(9), p.1721 - 1727, 2010/02
Times Cited Count：18 Percentile：48.53(Chemistry, Organic)N,N,N',N'-(tetrakis-2-pyridylmethyl)ethylenediamine (TPEN) derivatives bearing the different number (1-4) of a double bond moiety on the pyridine ring are synthesized and subjected to copolymerization with N-isopropylacrylamide in the presence of AIBN. The obtained poly(TPEN-NIPA)gels show thermo-responsive swelling/shrinking behaviors and are employed for the extraction of cadmium(II) ion from the aqueous solution to examine the relationship of the gel characteristics and the extraction performance. The polymer gels composed of the TPEN derivative bearing three or four double bonds exhibit temperature-dependent change of swelling and shrinking in water. These gels extract CdII ion efficiently from the aqueous solution in the swelling state at 5C, while little extraction was observed at 45C with shrinking.
Mirvaliev, R.*; Watanabe, Masayuki; Matsumura, Tatsuro; Tachimori, Shoichi*; Takeshita, Kenji*
Journal of Nuclear Science and Technology, 41(11), p.1122 - 1124, 2004/11
Times Cited Count：20 Percentile：76.55(Nuclear Science & Technology)Transmutation is a technology aimed to reduce HLW from reprocessing process. Minor actinides in the HLW will be converted to short-lived nuclides. However, lanthanides in HLW adversely affects on the efficiency of the transmutation. It is well known that separating An(III) and Ln(III) is very difficult because of their similarity of chemical properties. Therefore, the separation is one of the essential subjects to establish the transmutation technology. Considerable efforts have been devoted to the development of new extractants for the separation. N,N,N',N'-tetrakis(2-methylpyridyl)ethylenediamine (TPEN) demonstrates 100-fold preference for Am(III) over Ln(III) between stability constants with the ions in the aqueous phase. We have reported that Am(III) was selectively extracted from the aqueous phase containing Ln(III) by TPEN in nitrobenzene system and synergistic system with TPEN and D2EHPA in octanol. This work presents our recent results that Am(III) is separated from Eu(III) by a synergistic extraction system with TPEN and decanoic acid diluted with 1-octanol.
Hirose, Naoki*; Sergey, V.*; Watanabe, Tatsuro*; Kawamura, Hideyuki; Yamamoto, Masaru*
no journal, ,
The Japan Sea holds many features that are similar to world's oceans. We have been developing an ocean data assimilation and prediction system. There are currently two versions of the model aiming at short- and long-term forecasts. The short-term version is driven by tidal forcings and atmospheric predictions, and enables accurate forecasts for up to five days including tidal changes. Short-term outputs will be used for material drift simulations such as an oil spill. The long-term version is sequentially corrected by assimilating the sea surface temperature and height of satellites by the nudging and reduced-order Kalman filter, respectively. The assimilated model estimates realistic nowcast and forecast for a few months. We are also successful to predict a migration of giant jellyfish in 2005. The system will be extended to the East Asian Marginal Seas in the near future.
Takayama, Katsumi*; Hirose, Naoki*; Kawamura, Hideyuki; Shimizu, Daisuke*; Watanabe, Tatsuro*
no journal, ,
An ocean general circulation model in the Japan Sea has been being developed to reproduce and forecast movement of pollutants at JAEA. It was demonstrated that an assimilation of sea level variation at tide stations along the Japanese coast is effective to reproduce oceanic condition in the nearshore region. In this study, an effect of assimilation of satellite altimeter data, CTD data and tide data is quantitatively surveyed. As a result, it was demonstrated that this assimilation scheme improves the oceanic condition.
Takayama, Katsumi*; Watanabe, Tatsuro*; Kawamura, Hideyuki; Tanaka, Iori*
no journal, ,
Recently, researches of estimating a primary production are active by coupling an ocean general circulation model and a lower trophic level ecosystem model. This study aims to develop the vertically one-dimensional ecosystem model west of Hokkaido. The lower trophic level ecosystem model used in this study originates from the one-box NEMURO. It successfully reproduced spring and autumn phytoplankton bloom and maximum of phytoplankton concentration in the subsurface layer in summer.
Inaba, Yusuke*; Kida, Tatsuya*; Watanabe, Wataru*; Mori, Atsunori*; Matsumura, Tatsuro; Ogata, Takeshi*; Takeshita, Kenji*
no journal, ,
Separation of minor actinides (MAs) from lanthanides in high-level radioactive waste (HLW) becomes important in nuclear power generation. Although TPEN is a possible candidate for the practical separating agent for MAs from HLW, there still remains difficulties in high water solubility and easy protonation characteristics. The practical MA separation is conducted from a mixture of MAs and Ln(III) in a highly acidic aqueous solution, thereby a hydrophobic and acid tolerant chelating agent needs to be developed. We herein report efficient syntheses of TPEN derivatives bearing various hydrophobic side-chains, which are alkyloxy and fluorinated alkoxy groups, and solvent extraction of Am(III) from Eu(III) in nitric acid aqueous solution. Synthesized TPEN derivatives were hydrophobic and showed higher performance than unsubstituted TPEN for Am separation from Eu in extraction with water/organic solvents at low pH region.
Watanabe, Tatsuro*; Takayama, Katsumi*; Kawamura, Hideyuki; Tanaka, Iori*
no journal, ,
Based on an operational ocean forecast system, a one dimensional lower trophic ecosystem model was applied for understanding seasonal and vertical variations of the primary production in the northern Japan Sea. The ecosystem model successfully showed realistic seasonal variations and their vertical distributions of nitrate, phytoplankton and zooplankton. For example, the spring bloom occurred with approximately 1.5
10
molN/l in early April from the surface to the depth of 50 m.
Takayama, Katsumi*; Watanabe, Tatsuro*; Kawamura, Hideyuki; Tanaka, Iori*
no journal, ,
A three-dimensional lower trophic ecosystem model is applied to understand temporal and spatial variation of chlorophyll-a and nutrient in the Japan Sea. The lower trophic ecosystem model is driven by monthly solar radiation and daily temperature, current velocity and vertical diffusion coefficient calculated from the eddy-resolving ocean general circulation model. Satellite data of SeaWiFS on chlorophyll-a concentration at sea surface and long-term bimonthly data in the northern Japan Sea are used to validate model results. The lower trophic ecosystem model qualitatively reproduced seasonal variation of chlorophyll-a and nutrient. Spatial averages of correlation coefficient and RMS between the model results and the satellite-observed chlorophyll-a are 0.455 and 1.468 mg/m
, respectively.
Takayama, Katsumi*; Watanabe, Tatsuro*; Kawamura, Hideyuki
no journal, ,
Variation of chlorophyll-a is analyzed with three-dimensional lower trophic ecosystem model in this study. The lower trophic ecosystem model is driven by daily temperature, current velocity, and vertical diffusion coefficient and monthly solar radiation. Satellite data on chlorophyll-a concentration by MODIS/AQUA and chlorophyll-a concentration observed at PM line by Japan Meteorological Agency are used to validate model results. It is found that spatial average of correlation coefficient of chlorophyll-a concentration between model and observation is 0.403 and the correlation coefficient is comparatively low in the southwestern Japan Sea. The lower trophic ecosystem model qualitatively reproduced year-by-year variation of chlorophyll-a concentration as well as seasonal variation.
Koma, Yoshikazu; Sano, Yuichi; Nomura, Kazunori; Watanabe, So; Matsumura, Tatsuro; Morita, Yasuji
no journal, ,
Engineering system of the extraction chromatography for Am and Cm separation from spent FBR fuel is under development. Concerning the process development, experimental data including separation, safety and treatment after use was collected and evaluated that the combination of TODGA and R-BTP adsorbent was the most promising at present. Concerning the column system development, preparing a stationary phase bed, hydraulics of mobile phase, temperature control, discharging hydrogen which is radiolytically generated, column plugging which will bring a safety concern were investigated and it was revealed that the system has a potential for engineering application.
Koma, Yoshikazu; Sano, Yuichi; Nomura, Kazunori; Watanabe, So; Morita, Yasuji; Matsumura, Tatsuro; Asakura, Toshihide; Takeshita, Kenji*
no journal, ,
The extraction chromatography system was investigated in order to separate Am and Cm as minor actinides from the raffinate of reprocessing. Results from development conducted for 4 years will be summarized.
Nomura, Kazunori; Watanabe, So; Asakura, Toshihide; Koma, Yoshikazu; Sano, Yuichi; Matsumura, Tatsuro; Koizumi, Kenji; Nakajima, Yasuo; Morita, Yasuji; Washiya, Tadahiro
no journal, ,
no abstracts in English
Nishio, Katsuhisa; Hirose, Kentaro; Nishinaka, Ichiro; Makii, Hiroyuki; Ota, Shuya; Nagayama, Tatsuro*; Chiba, Satoshi; Tsukada, Kazuaki; Asai, Masato; Ishii, Tetsuro; et al.
no journal, ,
no abstracts in English
Hirose, Kentaro; Nishio, Katsuhisa; L
guillon, R.; Makii, Hiroyuki; Nishinaka, Ichiro; Orlandi, R.; Smallcombe, J.; Ishii, Tetsuro; Tsukada, Kazuaki; Asai, Masato; et al.
no journal, ,
