Refine your search:     
Report No.
 - 
Search Results: Records 1-20 displayed on this page of 119

Presentation/Publication Type

Initialising ...

Refine

Journal/Book Title

Initialising ...

Meeting title

Initialising ...

First Author

Initialising ...

Keyword

Initialising ...

Language

Initialising ...

Publication Year

Initialising ...

Held year of conference

Initialising ...

Save select records

Journal Articles

Interpretation of vertical migration and enrichment processes of rare earth elements (REEs) in ion-adsorption-type mineralization in Japan based on REE speciation analyses

Nagasawa, Makoto*; Shimizu, Yusuke*; Yamaguchi, Akiko; Tokunaga, Kohei; Mukai, Hiroki*; Aoyagi, Noboru; Mei, H.; Takahashi, Yoshio*

Chemical Geology, 670, p.122431_1 - 122431_25, 2024/12

 Times Cited Count:0 Percentile:0.00(Geochemistry & Geophysics)

Journal Articles

Sorption of Cs$$^{+}$$ and Eu$$^{3+}$$ onto coherent and melange-type pre-neogene sedimentary rocks

Hou, L.*; Toda, Kanako*; Mei, H.; Aoyagi, Noboru; Saito, Takumi*

Journal of Nuclear Science and Technology, 61(11), p.1488 - 1498, 2024/11

 Times Cited Count:0 Percentile:0.00(Nuclear Science & Technology)

Journal Articles

Trivalent lanthanide sorption onto illite in the presence of carbonate; A Study combining thermodynamic sorption modeling, time-resolved laser fluorescence spectroscopy, and parallel factor analysis

Sugiura, Yuki; Ishidera, Takamitsu; Aoyagi, Noboru; Mei, H.; Saito, Takumi*; Tachi, Yukio

Applied Clay Science, 258, p.107476_1 - 107476_10, 2024/09

 Times Cited Count:1 Percentile:0.00(Chemistry, Physical)

Journal Articles

Globular pattern formation of hierarchical ceria nanoarchitectures

Aoyagi, Noboru; Motokawa, Ryuhei; Okumura, Masahiko; Ueda, Yuki; Saito, Takumi*; Nishitsuji, Shotaro*; Taguchi, Tomitsugu*; Yomogida, Takumi; Sazaki, Gen*; Ikeda, Atsushi

Communications Chemistry (Internet), 7, p.128_1 - 128_13, 2024/06

 Times Cited Count:0 Percentile:0.00(Chemistry, Multidisciplinary)

Journal Articles

Impact of branching position and degree on uranium extraction by amines; A Supramolecular and thermodynamic study

Guerinoni, E.*; Giusti, F.*; Dourdain, S.*; Dufr$^e$che, J.-F.*; Motokawa, Ryuhei; Ueda, Yuki; Aoyagi, Noboru; Zemb, T.*; Pellet-Rostaing, S.*

Journal of Molecular Liquids, 403, p.124820_1 - 124820_11, 2024/06

 Times Cited Count:0 Percentile:0.00(Chemistry, Physical)

Journal Articles

U(VI) sorption on illite in the presence of carbonate studied by cryogenic time-resolved laser fluorescence spectroscopy and parallel factor analysis

Mei, H.; Aoyagi, Noboru; Saito, Takumi*; Tanaka, Kazuya; Sugiura, Yuki; Tachi, Yukio

Applied Geochemistry, 162, p.105926_1 - 105926_8, 2024/02

 Times Cited Count:2 Percentile:84.49(Geochemistry & Geophysics)

Journal Articles

Alteration of fuel debris simulants by Bacillus subtilis

Liu, J.; Dotsuta, Yuma; Kitagaki, Toru; Aoyagi, Noboru; Mei, H.; Takano, Masahide; Kozai, Naofumi

Journal of Nuclear Science and Technology, 60(8), p.1002 - 1012, 2023/08

 Times Cited Count:1 Percentile:34.39(Nuclear Science & Technology)

Journal Articles

Hydration states of europium(III) adsorbed on silicas with nano-sized pores

Murota, Kento*; Aoyagi, Noboru; Mei, H.; Saito, Takumi*

Applied Geochemistry, 152, p.105620_1 - 105620_11, 2023/05

 Times Cited Count:4 Percentile:68.69(Geochemistry & Geophysics)

Journal Articles

Hierarchical aggregation in a complex fluid; The Role of isomeric interconversion

Massey, D.*; Williams, C. D.*; Mu, J.*; Masters, A. J.*; Motokawa, Ryuhei; Aoyagi, Noboru; Ueda, Yuki; Antonio, M. R.*

Journal of Physical Chemistry B, 127(9), p.2052 - 2065, 2023/03

 Times Cited Count:2 Percentile:22.86(Chemistry, Physical)

Journal Articles

Synthesis of hybrid magnesium hydroxide/magnesium oxide nanorods [Mg(OH)$$_{2}$$/MgO] for prompt and efficient adsorption of ciprofloxacin from aqueous solutions

Falyouna, O.*; Bensaida, K.*; Maamoun, I.; Ashik, U. P. M.*; Tahara, Atsushi*; Tanaka, Kazuya; Aoyagi, Noboru; Sugihara, Yuji*; Eljamal, O.*

Journal of Cleaner Production, 342, p.130949_1 - 130949_15, 2022/03

 Times Cited Count:58 Percentile:98.42(Green & Sustainable Science & Technology)

Journal Articles

Uranium (VI) sorption on illite under varying carbonate concentrations; Batch experiments, modeling, and cryogenic time-resolved laser fluorescence spectroscopy study

Mei, H.; Aoyagi, Noboru; Saito, Takumi*; Kozai, Naofumi; Sugiura, Yuki; Tachi, Yukio

Applied Geochemistry, 136, p.105178_1 - 105178_8, 2022/01

 Times Cited Count:18 Percentile:89.94(Geochemistry & Geophysics)

Journal Articles

A Fluorous phosphate for the effective extraction of Ln$$^{III}$$ from nitrate media; Comparison with a conventional organic phosphate

Ueda, Yuki; Kikuchi, Kei*; Tokunaga, Kohei; Sugita, Tsuyoshi; Aoyagi, Noboru; Tanaka, Kazuya; Okamura, Hiroyuki

Solvent Extraction and Ion Exchange, 39(5-6), p.491 - 511, 2021/00

 Times Cited Count:4 Percentile:22.30(Chemistry, Multidisciplinary)

no abstracts in English

Journal Articles

Spectroscopic studies of M$"o$ssbauer, infrared, and laser-induced luminescence for classifying rare-earth minerals enriched in iron-rich deposits

Aoyagi, Noboru; Nguyen, T. T.*; Kumagai, Yuta; Nguyen, T. V.*; Nakada, Masami; Segawa, Yukari; Nguyen, H. T.*; Le, B. T.*

ACS Omega (Internet), 5(13), p.7096 - 7105, 2020/04

 Times Cited Count:4 Percentile:17.04(Chemistry, Multidisciplinary)

Journal Articles

High-efficiency synthesis and properties of latent pigment red 272DPP-BOC by microwave irradiation

Oishi, Tomoji*; Kimura, Yu*; Nakajima, Kiyohiko*; Watanabe, Masayuki; Aoyagi, Noboru

Materials Sciences and Applications, 11(3), p.195 - 203, 2020/03

A high-efficiency synthesis method for a latent pigment of red pigment diketo-pyrrolo-pyrrole (Pig. Red 272:272DPP), which is important as a functional organic pigment, was investigated, and the investigation results revealed that irradiation of microwaves (MWs) for several seconds to 272 DPP in NMP (N-methyl-2-pyrrolidone) solvent yielded DPP latent pigment (272DPP-BOC) at a high yield of 86.2%. Two kinds of latent-pigment crystals, namely, red and yellow, were obtained by recrystallization, and it was found that the fluorescence-emission properties of the two kinds differ significantly. Single-crystal X-ray structural analysis showed that the difference in the fluorescence-emission properties of the two types is derived from the difference in their crystal structures.

Journal Articles

Flow-electrode CDI removes the uncharged Ca-UO$$_{2}$$-CO$$_{3}$$ ternary complex from brackish potable groundwater; Complex dissociation, transport, and sorption

Ma, J.*; Zhang, Y.*; Collins, R. N.*; Tsarev, S.*; Aoyagi, Noboru; Kinsela, A. S.*; Jones, A. M.*; Waite, T. D.*

Environmental Science & Technology, 53(5), p.2739 - 2747, 2019/03

 Times Cited Count:58 Percentile:89.08(Engineering, Environmental)

Journal Articles

Optical properties of trinuclear citrate complexes containing 4f and 5f block metals

Aoyagi, Noboru; Palladino, G.*; Nagasaki, Shinya*; Kimura, Takaumi

Bulletin of the Chemical Society of Japan, 91(6), p.882 - 890, 2018/06

 Times Cited Count:3 Percentile:11.01(Chemistry, Multidisciplinary)

The speciation and coordination geometries of M(III)-citrate complexes in aqueous solutions, where M denotes Eu, Tb, Lu, or Cm, are studied using potentiometric titration, nuclear magnetic resonance spectroscopies. Their photophysical properties are also characterized by time-resolved fluorescence spectra. The formation constants of mononuclear, dinuclear, and trinuclear Lu-citrate species were determined by potentiometric titration in 3.00 M NaClO$$_{4}$$ aqueous media. Terminal carboxylic conformation in trinuclear complexes comprised both the five- and six-membered rings at different exchanging rates. Hydration states evaluated for Eu$$^{3+}$$ ions are the chemical formula of [Eu(Cit)$$_{2}$$ (H$$_{2}$$ O)$$_{2.5}$$ ]$$^{3-}$$ and [Eu$$_{3}$$(OH)$$_{4}$$(Cit)$$_{4}$$(H$$_{2}$$O)$$_{3.4}$$]$$^{7-}$$. These complexes in aqueous solution have geometrical similarity to the crystal structures in the literature. Furthermore, the entity of the hetero-trinuclear complex induces the intramolecular energy transfer from Tb$$^{3+}$$ to Eu$$^{3+}$$. The incorporation of Cm$$^{3+}$$ into these homo/hetero-trinuclear citrate complexes proved to be a successful trial to probe the formation of actinide polymer at a trace level.

Journal Articles

Europium binding to humic substances extracted from deep underground sedimentary groundwater studied by time-resolved laser fluorescence spectroscopy

Saito, Takumi*; Aoyagi, Noboru; Terashima, Motoki

Journal of Nuclear Science and Technology, 54(4), p.444 - 451, 2017/04

 Times Cited Count:7 Percentile:53.23(Nuclear Science & Technology)

Humic substances (HSs) are ubiquitous in various environments including deep underground and play an important role in the speciation and mobility of radionuclides. The binding of Eu$$^{3+}$$, a chemical homologue of trivalent actinide ions, to HSs isolated from sedimentary groundwater at -250 m below the surface was studied by time-resolved laser fluorescence spectroscopy combined with parallel factor analysis (PARAFAC) as a function of pH and salt concentration. PARAFAC modeling reveals the presence of multiple factors that corresponds to different Eu$$^{3+}$$ species. These factors resemble those observed for Eu$$^{3+}$$ binding to HSs from surface environments; however, detailed comparison shows that there are some particularities in Eu$$^{3+}$$ binding to the deep groundwater HSs. The distribution coefficients ($$K_{rm d}$$) of Eu$$^{3+}$$ binding to the HSs calculated from the PARAFAC modeling exhibits a rather strong salt effect. At 0.01 M NaClO$$_{4}$$ the $$K_{rm d}$$ values are relatively large and comparable to those to the surface HSs; they are decreaed at 0.1 M NaClO$$_{4}$$ by more than an order of the magnitude. The $$K_{rm d}$$ values are larger for humic acid fraction of the deep underground HSs than fulvic acid over the entire range of pH and salt concentration investigated in this study.

JAEA Reports

Preliminary missions for the decommissioning of the laboratory building No.1 for the plutonium research program

Segawa, Yukari; Horita, Takuma; Kitatsuji, Yoshihiro; Kumagai, Yuta; Aoyagi, Noboru; Nakada, Masami; Otobe, Haruyoshi; Tamura, Yukito*; Okamoto, Hisato; Otomo, Takashi; et al.

JAEA-Technology 2016-039, 64 Pages, 2017/03

JAEA-Technology-2016-039.pdf:5.24MB

The laboratory building No.1 for the plutonium research program (Bldg. Pu1) was chosen as one of the facilities to decommission by Japan Atomic Energy Agency Reform in September, 2013. The research groups, users of Bldg. Pu1, were driven by necessity to remove used equipment and transport nuclear fuel to other facilities from Bldg. Pu1. Research Group for Radiochemistry proactively established the Used Equipment Removal Team for the smooth operation of the removal in April, 2015. The team classified six types of work into the nature of the operation, removal of used equipment, disposal of chemicals, stabilization of mercury, stabilization of nuclear fuel, transportation of nuclear fuel and radioisotope, and survey of contamination status inside the glove boxes. These works were completed in December, 2015. This report circumstantially shows six works process, with the exception of the approval of the changes on the usage of nuclear fuel in Bldg. Pu1 to help prospective decommission.

Journal Articles

Role of Tf$$_{2}$$N$$^{-}$$ anions in the ionic liquid-water distribution of europium(III) chelates

Okamura, Hiroyuki; Aoyagi, Noboru; Shimojo, Kojiro; Naganawa, Hirochika; Imura, Hisanori*

RSC Advances (Internet), 7(13), p.7610 - 7618, 2017/01

 Times Cited Count:20 Percentile:53.88(Chemistry, Multidisciplinary)

The role of bis(trifluoromethanesulfonyl)imide (Tf$$_{2}$$N$$^{-}$$) anions in the ionic liquid-water distribution systems of the Eu(III) chelates with 2-thenoyltrifluoroacetone (Htta) was investigated by the liquid-liquid distribution and time-resolved laser-induced fluorescence spectroscopy (TRLFS). The effect of the ionic liquids on the distribution constant of Eu(tta)$$_{3}$$ was evaluated by the regular solution theory. The distribution constant of Eu(tta)$$_{3}$$ in 1-alkyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide ([C$$_{n}$$mim][Tf$$_{2}$$N]) was increased dramatically by the solvation effects of Eu(tta)$$_{3}$$ in [C$$_{n}$$mim][Tf$$_{2}$$N]. TRLFS for [Eu(tta)$$_{3}$$(H$$_{2}$$O)$$_{3}$$] synthesized revealed that the Eu(tta)$$_{3}$$ chelate was almost completely dehydrated in a series of [C$$_{n}$$mim][Tf$$_{2}$$N]. The Eu(tta)$$_{3}$$ chelate exists as di- or tri-hydrates in 1-ethyl-3-methylimidazolium perchlorate ([C$$_{2}$$mim][ClO$$_{4}$$]) containing 20 M water, whereas mono-hydrated chelate was formed in [C$$_{2}$$mim][Tf$$_{2}$$N, ClO$$_{4}$$] in the presence of 0.50 M Tf$$_{2}$$N$$^{-}$$ and 20 M water. These results show that the coordinated water molecules of [Eu(tta)$$_{3}$$(H$$_{2}$$O)$$_{3}$$] were replaced by the Tf$$_{2}$$N$$^{-}$$ anions. In fact, an anionic adduct, [Eu(tta)$$_{3}$$(Tf$$_{2}$$N)]$$^{-}$$, was observed by electrospray ionization mass spectrometry in the presence of [C$$_{4}$$mim][Tf$$_{2}$$N].

Journal Articles

Sorption of Eu$$^{3+}$$ on Na-montmorillonite studied by time-resolved laser fluorescence spectroscopy and surface complexation modeling

Sasaki, Takayuki*; Ueda, Kenyo*; Saito, Takumi; Aoyagi, Noboru; Kobayashi, Taishi*; Takagi, Ikuji*; Kimura, Takaumi; Tachi, Yukio

Journal of Nuclear Science and Technology, 53(4), p.592 - 601, 2016/04

 Times Cited Count:14 Percentile:76.34(Nuclear Science & Technology)

The influences of pH and the concentrations of Eu$$^{3+}$$ and NaNO$$_{3}$$ on the sorption of Eu$$^{3+}$$ to Na-montmorillonite were investigated through batch sorption measurements and time-resolved laser fluorescence spectroscopy (TRLFS). The pH had a little effect on the distribution coefficients (Kd) in 0.01 M NaNO$$_{3}$$, whereas the Kd strongly depended on pH at 1 M NaNO$$_{3}$$. A cation exchange model combined with a one-site non-electrostatic surface complexation model was successfully applied to the measured Kd. The TRLFS spectra of Eu$$^{3+}$$ sorbed were processed by parallel factor analysis (PARAFAC), which corresponded to one outer-sphere (factor A) and two inner-sphere (factor B and C) complexes. It turned out that factors A and B correspond to Eu$$^{3+}$$ sorbed by ion exchange sites and inner-sphere complexation with hydroxyl groups of the edge faces, respectively. Factor C became dominant at relatively high pH and ionic strength and likely correspond to the precipitation of Eu(OH)$$_{3}$$ on the surface.

119 (Records 1-20 displayed on this page)