Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Okamura, Hiroyuki; Mizuno, Masayoshi*; Hirayama, Naoki*; Shimojo, Kojiro; Naganawa, Hirochika; Imura, Hisanori*
Industrial & Engineering Chemistry Research, 59(1), p.329 - 340, 2020/01
Times Cited Count：15 Percentile：57.71(Engineering, Chemical)The synergistic ionic-liquid extraction and extraction equilibrium of lanthanoid(III) (Ln(III)) ions have been investigated using 2-thenoyltrifluoroacetone (Htta) and trioctylphosphine oxide (TOPO) in the ionic liquid 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide ([C
mim][Tf
N]). The selective synergistic effect for heavier Ln(III) ions was found using a combination of Htta and TOPO in [Cmim][TfN], leading to enhanced separability among Ln(III) ions. The extracted Ln(III) species and the extraction constants in the Htta-TOPO system were determined by three-dimensional extraction equilibrium analysis. The selective synergism for heavier Ln(III) ions in the Htta-TOPO system was ascribed to the formation of hydrophobic, charged adducts, such as Ln(tta)(TOPO)
and Ln(tta)(TOPO)
, in [Cmim][TfN].
Mikake, Shinichiro; Yamamoto, Masaru; Ikeda, Koki; Sugihara, Kozo; Takeuchi, Shinji; Hayano, Akira; Sato, Toshinori; Takeda, Shinichi; Ishii, Yoji; Ishida, Hideaki; et al.
JAEA-Technology 2010-026, 146 Pages, 2010/08
JAEA-Technology-2010-026.pdf:41.08MB
JAEA-Technology-2010-026-appendix(CD-ROM).zip:83.37MB
The Mizunami Underground Research Laboratory (MIU), one of the main facilities in Japan for research and development of the technology for high-level radioactive waste disposal, is under construction in Mizunami City. In planning the construction, it was necessary to get reliable information on the bedrock conditions, specifically the rock mass stability and hydrogeology. Therefore, borehole investigations were conducted before excavations started. The results indicated that large water inflow could be expected during the excavation around the Ventilation Shaft at GL-200m and GL-300m Access/Research Gallery. In order to reduce water inflow, pre-excavation grouting was conducted before excavation of shafts and research tunnels. Grouting is the injection of material such as cement into a rock mass to stabilize and seal the rock. This report describes the knowledge and lessons learned during the planning and conducting of pre-excavation grouting.
Li, M.*; Nagashio, Kosuke*; Ishikawa, Takehiko*; Mizuno, Akitoshi*; Adachi, Masayoshi*; Watanabe, Masahito*; Yoda, Shinichi*; Kuribayashi, Kazuhiko*; Katayama, Yoshinori
Acta Materialia, 56(11), p.2514 - 2525, 2008/06
Times Cited Count：23 Percentile：71.73(Materials Science, Multidisciplinary)Co-61.8 at.% Si (CoSe-CoSi) eutectic alloys were solidified on an electromagnetic levitator (EML) and an electrostatic levitator (ESL) at different undercooling levels. The results indicated that there is only a single recalescence event at low undercooling with the CoSi intermetallic compound as primary phase, which is independent of processing facilities, on either an EML or an ESL. The microstructure, however, is strongly dependent on the processing facility. On high undercooling, double recalescence takes place regardless of levitation condition. In situ X-ray diffraction of alloys solidified on the EML demonstrates that the CoSi compound becomes the primary phase upon the first recalescence, and the CoSi intermetallic phase crystallizes during the second recalescence. In addition to phase identification, real-time diffraction patterns can also provide additional evidence of the fragmentation of the primary phase.
Saegusa, Hiromitsu; Seno, Yasuhiro; Nakama, Shigeo; Tsuruta, Tadahiko; Iwatsuki, Teruki; Amano, Kenji; Takeuchi, Ryuji; Matsuoka, Toshiyuki; Onoe, Hironori; Mizuno, Takashi; et al.
JAEA-Research 2007-043, 337 Pages, 2007/03
JAEA-Research-2007-043.pdf:28.14MB
The Mizunami Underground Laboratory (MIU) Project is a comprehensive research project investigating the deep underground environment within crystalline rock being conducted by Japan Atomic Energy Agency at Mizunami City in Gifu Prefecture, central Japan. This report summarizes the results of the Surface-based Investigation Phase, identifies future issues and provides direction for research to be conducted during Construction Phase and Operation Phase. The results compiled in this report will be utilized for the technical knowledge base on geological disposal of HLW, and can be used to enhance the technical basis for waste disposal in general and for development of government regulations.
Nagashio, Kosuke*; Adachi, Masayoshi*; Higuchi, Kensuke*; Mizuno, Akitoshi*; Watanabe, Masahito*; Kuribayashi, Kazuhiko*; Katayama, Yoshinori
Journal of Applied Physics, 100(3), p.033524_1 - 033524_6, 2006/08
Times Cited Count：14 Percentile：47.16(Physics, Applied)Grain refined microstructure is often obtained spontaneously in the solidification of metals and semiconductors from the undercooled melt without any external forces. Although it has been reported that the grain refinement is mainly caused by the fragmentation of the dendrites, the dynamic process of the fragmentation of dendrites has not been fully understood because the microstructure after the solidification has been analyzed. Here, we present a time-resolved 2- dimensional X-ray diffraction experiment on the solidification of Si from the undercooled melt. The number of diffraction spots observed at low undercoolings (
100K) did not increase at the plateau stage, while the diffraction pattern at medium undercoolings (100K
200K) changed from the spots with the tail to rings with the lapse of time. Both this result and high speed video imaging suggested that the high-order arms of the dendrites mostly detached from the main stems because nucleation could not be expected at the melting point after recalescence. The several spots observed at low undercoolings drastically changed to rings at high undercoolings (
200K), which indicated the complete fragmentation of dendrite main stem as well as high-order arms. This complete fragmentation resulted in the grain refined microstructure.
Konomura, Mamoru; Ogawa, Takashi; Okano, Yasushi; Yamaguchi, Hiroyuki; Murakami, Tsutomu; Takaki, Naoyuki; Nishiguchi, Youhei; Sugino, Kazuteru; Naganuma, Masayuki; Hishida, Masahiko; et al.
JNC TN9400 2004-035, 2071 Pages, 2004/06
JNC-TN9400-2004-035.pdf:76.42MB
The attractive concepts for Sodium-, lead-bismuth-, helium- and water-cooled FBRs have been created through using typical plant features and employing advanced technologies. Efforts on evaluating technological prospects of feasibility have been paid for these concepts. Also, it was comfirmed if these concepts satisfy design requierments of capability and performance presumed in the feasibilty study on commertialization of Fast Breeder Reactor Systems. As results, it was concluded that the selection of sodium-cooled reactor was most rational for practical use of FBR technologies in 2015.
Takeuchi, Shinji; Hayano, Akira; Ikeda, Koki; Mikake, Shinichiro; Hara, Masato; Yamamoto, Masaru; Tsuruta, Tadahiko; Nakamata, Kiminori; Takeuchi, Ryuji; Saegusa, Hiromitsu; et al.
no journal, ,
The results from the pilot borehole investigations conducted at FY2006 at Mizunami Underground Research Laboratory are presented. The investigations are carried out to obtain various information for the planning of water treatment facility, planning for the grouting and revision for the construction design by understanding the geological environment below the excavating area. From the result of the investigations, important section of the inflow water and hydrochemical composition which should be treated in the water treatment facility have been obtained. Required informations on the planning for the future construction of MIU are addressed.
Saegusa, Hiromitsu; Yasue, Kenichi; Mizuno, Takashi; Takeuchi, Ryuji; Tajikara, Masayoshi; Kurosawa, Hideki
no journal, ,
no abstracts in English
Okamura, Hiroyuki; Mizuno, Masayoshi*; Hirayama, Naoki*; Shimojo, Kojiro; Naganawa, Hirochika; Imura, Hisanori*
no journal, ,
Solvent extraction technique is widely investigated to separate lanthanoids (Ln). The development of a more effective separation system is an important issue in the field of atomic energy. Recently, the synergistic ionic-liquid (IL) extraction of Ln(III) with several 
-diketones and trioctylphosphine oxide (TOPO) in 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide was studied, and it was found that the separability of Ln(III) was remarkably enhanced by the selective synergism for heavier rate earth. In this study, the method of extraction equilibrium analysis for Ln(III) in the synergistic ionic-liquid extraction system with 2-thenoyltrifluoroacetone (Htta) and TOPO was investigated. To determine the extraction constants of the respective Ln(III) complexes, a three-dimensional non-linear analysis of log 
-log [tta
]
-log [TOPO]
was applied. The formation constants of various ternary complexes formed in IL were calculated, and the order of the formation constants of the Ln(tta)(TOPO) complexes was found to be Eu(III) 
Nd(III). Consequently, it was suggested that the formation of hydrophobic charged complexes is a factor for the selective synergism.
Okamura, Hiroyuki; Mizuno, Masayoshi*; Hirayama, Naoki*; Shimojo, Kojiro; Naganawa, Hirochika; Imura, Hisanori*
no journal, ,
We studied the ionic liquid (IL) extraction of lanthanoids(III) (Ln) with several -diketones and trioctylphosphine oxide (TOPO) in 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide, and clarified that the separability of Ln was remarkably enhanced by the selective synergism for heavier rate earth. In this study, the extraction equilibria including several adduct formations for Nd, Eu, and Lu in the synergistic ionic-liquid extraction system with 2-thenoyltrifluoroacetone (Htta) and TOPO was investigated. The respective extraction constants of each adduct were determined from a three-dimensional non-linear analysis of log -log [tta]-log [TOPO], and the formation constants of each adduct in IL were calculated. The order of the formation constants of Ln(tta)(TOPO) was found to be Lu Eu Nd. Therefore, it was indicated that the formation of hydrophobic charged ternary complexes is a factor for the selective synergism.
Okamura, Hiroyuki; Mizuno, Masayoshi*; Hirayama, Naoki*; Shimojo, Kojiro; Naganawa, Hirochika; Imura, Hisanori*
no journal, ,
Ionic liquids have been widely investigated as novel functional extraction media in solvent extraction. We have investigated the synergistic ionic-liquid extraction of lanthanoids(III) (Ln(III)), and revealed that the synergistic effect is effective for the selective separation of Ln(III). In this study, the synergistic ionic-liquid extraction of Ln(III) with 2-thenoyltrifluoroacetone and trioctylphosphine oxide in 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide was investigated to evaluate the synergistic effect. In the ionic liquid system, the synergistic effect on selective extraction for heavier Ln(III) was observed in contrast to the conventional organic solvent systems. The slope analysis indicated that the neutral adduct and the cationic ternary complexes are extracted. The adduct formation constant of the cationic ternary complex increased with an increase in the atomic number. These results indicate that the formation of hydrophobic charged ternary complexes is a main factor for the selective synergistic effect toward heavier Ln(III).
