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Ueda, Yuki; Kobayashi, Toru; Nakamura, Satoshi; Ban, Yasutoshi; Kaneta, Yui; Nabatame, Nozomi; Micheau, C.; Tokunaga, Kohei; Nakabe, Rintaro; Kaneko, Masashi*; et al.
Langmuir, 42(1), p.1613 - 1626, 2026/01
Times Cited Count：0 Percentile：0.00(Chemistry, Multidisciplinary)Understanding the structural factors governing the metal ions selectivity of solvent extraction systems is crucial for developing advanced processes for partitioning and transmutation of high-level radioactive waste. Here, we systematically investigated the effect of alkyl side-chain branching in nitrilotriacetamide (NTAamide) extractants on the extraction of lanthanum (La) and neodymium (Nd), chosen as representative lanthanides. Four extractants having each eight carbon atoms as one of the amide chains with identical molecular weights but different degrees of alkyl branching were examined. Distribution ratios were measured as a function of HNO
concentration, and the local coordination structures of La and Nd were analyzed by extended X-ray absorption fine structure (EXAFS), while supramolecular aggregation in the organic phase was characterized by small-angle neutron scattering (SANS). EXAFS analysis revealed that the inner-sphere coordination environment of La and Nd was essentially unaffected by the degree of alkyl branching. In contrast, SANS results showed that extractants with fewer branched alkyl groups formed larger aggregates at low HNO concentrations, particularly in the case of Nd, where aggregation was found to facilitate extraction and prevent precipitation of poorly soluble complexes. These findings demonstrate that alkyl branching strongly influences supramolecular aggregation, which in turn governs extraction behavior. This work highlights the potential of nanoscale structural control as a new design concept for improving selectivity in lanthanide and actinide solvent extraction systems.
Ohno, Shuji; Maeda, Seiichiro; Wakai, Takashi; Ueda, Masashi; Kamide, Hideki
Nihon Kikai Gakkai-Shi, 127(1267), p.29 - 32, 2024/06
This paper introduces outlines, current status and topics of sodium-cooled fast reactor research and development performed in JAEA.
Matsumura, Takeshi*; Tsukakoshi, Mitsuru*; Ueda, Yoshihisa*; Higa, Nonoka*; Nakao, Akiko*; Kaneko, Koji; Kakihana, Masashi*; Hedo, Masato*; Nakama, Takao*; Onuki, Yoshichika*
Journal of the Physical Society of Japan, 91(7), p.073703_1 - 073703_5, 2022/07
Times Cited Count：10 Percentile：62.38(Physics, Multidisciplinary)Fuchita, Tomoki*; Urata, Taisei*; Matsuyama, Tsugufumi*; Murakami, Masashi; Yoshida, Yukihiko; Ueda, Akihiko; Machida, Masahiko; Sasaki, Toshiki; Tsuji, Koichi*
Advances in X-Ray Chemical Analysis, Japan, 53, p.77 - 87, 2022/03
X-ray fluorescence (XRF) analysis is an analytical method to obtain elemental information by detecting fluorescence X-rays emitted from a sample irradiated with X-rays. It is possible to obtain two-dimensional elemental distribution images by scanning a sample with micro X-ray beam. In this study, we developed an XRF analytical instrument to rapidly obtain the elemental distributions for moving samples on a belt conveyor by applying the micro XRF technique. X-rays were widely irradiated to the belt conveyor. The elemental distributions were measured by scanning an X-ray detector, crossing above the belt conveyor. A collimator was attached to the top of the detector to limit the analyzing area. Both detection limit and spatial resolutions for moving directions of the detector and the belt conveyor were evaluated. Finally, it was demonstrated that the multi-elemental imaging was possible with the developed XRF instrument.
ladderUeda, Hiroshi*; Onoda, Shigeki*; Yamaguchi, Yasuhiro*; Kimura, Tsuyoshi*; Yoshizawa, Daichi*; Morioka, Toshiaki*; Hagiwara, Masayuki*; Hagihara, Masato*; Soda, Minoru*; Masuda, Takatsugu*; et al.
Physical Review B, 101(14), p.140408_1 - 140408_6, 2020/04
Times Cited Count：6 Percentile：25.56(Materials Science, Multidisciplinary)Mihalache, O.; Yamaguchi, Toshihiko; Shirahama, Takuma; Ueda, Masashi
International Journal of Applied Electromagnetics and Mechanics, 59(3), p.1161 - 1168, 2019/03
Times Cited Count：7 Percentile：33.75(Engineering, Electrical & Electronic)Yamaguchi, Toshihiko; Mihalache, O.; Ueda, Masashi
International Journal of Applied Electromagnetics and Mechanics, 59(4), p.1469 - 1477, 2019/03
Times Cited Count：8 Percentile：37.51(Engineering, Electrical & Electronic)Saruta, Koichi; Shirahama, Takuma*; Yamaguchi, Toshihiko; Ueda, Masashi
E-Journal of Advanced Maintenance (Internet), 10(2), p.1 - 8, 2018/08
Nishimura, Akihiko; Takenaka, Yusuke*; Furusawa, Akinori; Torimoto, Kazuhiro; Ueda, Masashi; Fukuda, Naoaki*; Hirao, Kazuyuki*
E-Journal of Advanced Maintenance (Internet), 9(2), p.52 - 59, 2017/08
no abstracts in English
Mihalache, O.; Yamaguchi, Toshihiko; Shirahama, Takuma; Ueda, Masashi
E-Journal of Advanced Maintenance (Internet), 9(2), p.60 - 65, 2017/08
Mihalache, O.; Yamaguchi, Toshihiko; Shirahama, Takuma; Ueda, Masashi
Proceedings of 3rd International Conference on Maintenance Science and Technology (ICMST 2016) (Internet), 2 Pages, 2016/11
Mihalache, O.; Yamaguchi, Toshihiko; Shirahama, Takuma*; Ueda, Masashi
International Journal of Applied Electromagnetics and Mechanics, 52(1-2), p.659 - 666, 2016/09
Times Cited Count：3 Percentile：18.55(Engineering, Electrical & Electronic)Yamaguchi, Toshihiko; Mihalache, O.; Ueda, Masashi
International Journal of Applied Electromagnetics and Mechanics, 52(3-4), p.1185 - 1191, 2016/08
Times Cited Count：1 Percentile：7.72(Engineering, Electrical & Electronic)The paper presents application of a multi-coil eddy current testing (ECT) system to detect defects in steam generator (SG) tubes of Fast Breeder Reactors (FBR). The defects are located near SG tube support plates, while SG tubes were successively immersed in liquid sodium at temperature above 500 degrees and then drain. Three dimensional (3D) Finite Element Method (FEM) numerical simulations, using an in-house developed code, are validated with experimental measurements in both cases of absence/presence of sodium on the outer SG tubes surface.
Saruta, Koichi; Yamaguchi, Toshihiko; Ueda, Masashi
E-Journal of Advanced Maintenance (Internet), 7(4), p.NT75_1 - NT75_8, 2016/02
Saruta, Koichi; Yamaguchi, Toshihiko; Ueda, Masashi
EUR-27790-EN, p.209 - 214, 2016/00
Yamaguchi, Toshihiko; Mihalache, O.; Ueda, Masashi
Electromagnetic Nondestructive Evaluation (XVII), p.144 - 154, 2014/00
Times Cited Count：3 Percentile：82.82(Engineering, Electrical & Electronic)For a Fast Breeder Reactor (FBR) cooled by liquid sodium, the wall of steam generator tubes (SG) is the only barrier between sodium in the tubes vessel and water inside of tubes. By using eddy currents, the SG tube integrity is usually assured during the In-Service Inspection (ISI). During this procedure, the 500 degrees sodium is drained and then SG tubes cooled down slowly in 2 weeks to room temperature. After sodium draining, sodium adheres to SG tubes and other structures in the SG vessel in thin layers. Experimental data shows that sodium drops also appear in specific areas along tubes or tube support plates. The high electrical conductivity of sodium adhering to the outer SG tube surface influences the ECT signal according to sodium layer thickness or sodium deposits located on the outer SG tube surface. The sodium adhering properties depends on several factors among them being the surface roughness of tube material, sodium temperature and wetting time. The ECT effect of sodium adhering to the outer SG tube surface was measured using a small mock-up tank in which were introduced SG tubes similar with the ones in FBR (2.25Cr-1Mo alloy). Defects and support plates were added to tubes and ECT signal was measured before and after sodium draining. Variations in the sodium layer thickness and consequently its ECT effect were measured by filling and draining the tank three times in order to recreate each time new layers of sodium. The paper describes the experimental conditions for defects, SG support plates signal before and after draining of sodium. Additionally, sodium structures were visualized using a CCD camera, confirming the recorded ECT signals. The paper presents details about sodium layer measurements for several parts of the SG tubes by scratching and collecting the sodium on small areas 10x10 square mm. Numerical 3D simulations are performed using a 3D FEM code developed in our laboratory in order to validate the performance of the ECT sensors detection.
Mihalache, O.; Yamaguchi, Toshihiko; Ueda, Masashi
Electromagnetic Nondestructive Evaluation (XVII), p.109 - 119, 2014/00
Times Cited Count：3 Percentile：82.82(Engineering, Electrical & Electronic)Maeda, Yukihiro; Yamaguchi, Toshihiko; Ueda, Masashi; Fujiki, Kazunari*
Nihon Hozen Gakkai Dai-10-Kai Gakujutsu Koenkai Yoshishu, p.599 - 601, 2013/07
An inspection system was developed for in-service inspection (ISI) of pipes in the primary heat transfer system of MONJU FBR. The system was updated and modified based on experience from the pre-service inspection and related tests. This paper describes the results of the functional tests of the new inspection system on a mockup and in MONJU, which confirmed it can satisfy the expected performance.
Garcia Rodriguez, D.; Mihalache, O.; Ueda, Masashi
Proceedings of 16th International Symposium on Applied Electromagnetics and Mechanics (ISEM 2013), p.219 - 220, 2013/07
SeYe, M.*; Kuroda, Kenta*; Takeda, Yukiharu; Saito, Yuji; Okamoto, Kazuaki*; Zhu, S.-Y.*; Shirai, Kaito*; Miyamoto, Koji*; Arita, Masashi*; Nakatake, Masashi*; et al.
Journal of Physics; Condensed Matter, 25(23), p.232201_1 - 232201_5, 2013/06
Times Cited Count：12 Percentile：45.48(Physics, Condensed Matter)no abstracts in English
