Organization of malonamides from the interface to the organic bulk phase

Micheau, C.; Ueda, Yuki; Motokawa, Ryuhei; Akutsu, Kazuhiro*; Yamada, Norifumi*; Yamada, Masako*; Moussaoui, S. A.*; Makombe, E.*; Meyer, D.*; Berthon, L.*; et al.

Journal of Molecular Liquids, 401, p.124372_1 - 124372_12, 2024/05

https://doi.org/10.1016/j.molliq.2024.124372

Supramolecular organization of extractant molecules impacts metal ions separation behavior. Probing bulk and interfacial structures of the relevant systems is expected to provide key insights into the metal ion selectivity and kinetic aspects. The supramolecular features of two solvent extraction systems based on malonamide extractants THMA in toluene and DBMA in n-heptane were studied using small-angle X-ray scattering for the organic bulk phases, as well as interfacial tension and neutron reflectivity measurements for the interfaces. In the bulk solution, THMA forms dimeric/trimeric associates but no aggregates in toluene, while DBMA forms large aggregates in n-heptane. On the other hand, THMA accumulates in a diffuse layer at the interface at high THMA concentration, whereas DBMA forms a compact but thinner layer. After Pd(II) extraction, the thickness of interfacial layers decreases in the case of THMA, and totally vanishes in the case of DBMA. Based on these new structural information, two mechanisms are proposed for Pd(II) and Nd(III) extraction with malonamides. In toluene, THMA associates slightly accumulate in the vicinity of the interface, then coordinate Pd(II) and diffuse into the organic bulk phase. In n-heptane, DBMA aggregates adsorb at the interface then pick up Nd(III) cations in their polar cores and finally diffuse into the bulk.

Development of rapid and sensitive radionuclide analysis method by simultaneous analysis of , , and X-rays (Contract research); FY2022 Nuclear Energy Science & Technology and Human Resource Development Project

Collaborative Laboratories for Advanced Decommissioning Science; Japan Chemical Analysis Center*

JAEA-Review 2023-022, 93 Pages, 2023/12

JAEA-Review-2023-022.pdf:4.7MB

The Collaborative Laboratories for Advanced Decommissioning Science (CLADS), Japan Atomic Energy Agency (JAEA), had been conducting the Nuclear Energy Science & Technology and Human Resource Development Project (hereafter referred to "the Project") in FY2022. The Project aims to contribute to solving problems in the nuclear energy field represented by the decommissioning of the Fukushima Daiichi Nuclear Power Station, Tokyo Electric Power Company Holdings, Inc. (TEPCO). For this purpose, intelligence was collected from all over the world, and basic research and human resource development were promoted by closely integrating/collaborating knowledge and experiences in various fields beyond the barrier of conventional organizations and research fields. The sponsor of the Project was moved from the Ministry of Education, Culture, Sports, Science and Technology to JAEA since the newly adopted proposals in FY2018. On this occasion, JAEA constructed a new research system where JAEA-academia collaboration is reinforced and medium-to-long term research/development and human resource development contributing to the decommissioning are stably and consecutively implemented. Among the adopted proposals in FY2020, this report summarizes the research results of the "Development of rapid and sensitive radionuclide analysis method by simultaneous analysis of , , and X-rays" conducted from FY2020 to FY2022. The present study aims to enable rapid analysis of radionuclides in fuel debris and waste, we have established the latest measurement system, such as the multiple -ray detection methods, and the Spectral Determination Method (hereinafter referred to as "SDM") was developed. In the research in 2022, we developed a code that handles measurement data of LSC, singles Ge, and 2D spectra (multiple ). In addition, to develop an integrated database, spectral data of 40 nuclides were obtained by actual measurements and simulation calculations.

Deformation mechanism of a strong and ductile maraging steel investigated using X-ray synchrotron diffraction

Li, H.*; Liu, Y.*; Zhao, W.*; Liu, B.*; Tominaga, Aki; Shobu, Takahisa; Wei, D.*

International Journal of Plasticity, 165, p.103612_1 - 103612_20, 2023/06

https://doi.org/10.1016/j.ijplas.2023.103612

In order to clarify the strength properties of Co-free maraging steel, tensile experiment using high energy synchrotron X-ray diffraction was performed. Diffraction profiles from the martensitic and austenitic phases were obtained, and their strength and width were observed to vary as loading. Analysis of the diffraction profiles showed that the content of martensite in the as-aged material decreased slowly at low stress levels and decreased rapidly at high stress levels. On the other hand, the austenite phase in the as-solution materials was significantly transformed the martensite phase as the stress increased. It was clarified to be responsible for their respective strength properties.

A Study on convection in molten zone of aluminum alloy during Fe/Al resistance spot welding

Iyota, Muneyoshi*; Matsuda, Tomoki*; Sano, Tomokazu*; Shigeta, Masaya*; Shobu, Takahisa; Yumoto, Hirokatsu*; Koyama, Takahisa*; Yamazaki, Hiroshi*; Semba, Yasunori*; Ohashi, Haruhiko*; et al.

Journal of Manufacturing Processes, 94, p.424 - 434, 2023/05

https://doi.org/10.1016/j.jmapro.2023.03.032

Automatic object recognition using deep learning for legacy waste treatment

Yoshida, Yukihiko

IL Nuovo Cimento, 46(2), p.33_1 - 33_8, 2023/03

https://doi.org/10.1393/ncc/i2023-23033-x

Insight on the mechanical properties of hierarchical porous calcium-silicate-hydrate pastes according to the Ca/Si molar ratio using synchrotron X-ray scattering and nanoindentation test

Im, S.*; Jee, H.*; Suh, H.*; Kanematsu, Manabu*; Morooka, Satoshi; Choe, H.*; Nishio, Yuhei*; Machida, Akihiko*; Kim, J.*; Lim, S.*; et al.

Construction and Building Materials, 365, p.130034_1 - 130034_18, 2023/02

https://doi.org/10.1016/j.conbuildmat.2022.130034

Effect of magnesium silicate hydrate (M-S-H) formation on the local atomic arrangements and mechanical properties of calcium silicate hydrate (C-S-H); In situ X-ray scattering study

Kim, G.*; Im, S.*; Jee, H.*; Suh, H.*; Cho, S.*; Kanematsu, Manabu*; Morooka, Satoshi; Koyama, Taku*; Nishio, Yuhei*; Machida, Akihiko*; et al.

Cement and Concrete Research, 159, p.106869_1 - 106869_17, 2022/09

https://doi.org/10.1016/j.cemconres.2022.106869

Study on the relation between the crystal structure and thermal stability of FeUO and CrUO

Akiyama, Daisuke*; Kusaka, Ryoji; Kumagai, Yuta; Nakada, Masami; Watanabe, Masayuki; Okamoto, Yoshihiro; Nagai, Takayuki; Sato, Nobuaki*; Kirishima, Akira*

Journal of Nuclear Materials, 568, p.153847_1 - 153847_10, 2022/09

https://doi.org/10.1016/j.jnucmat.2022.153847

FeUO, CrUO, and FeCrUO are monouranates containing pentavalent U. Even though these compounds have similar crystal structures, their formation conditions and thermal stability are significantly different. To determine the factors causing the difference in thermal stability between FeUO and CrUO, their crystal structures were evaluated in detail. A Raman band was observed at 700 cm in all the samples. This Raman band was derived from the stretching vibration of the O-U-O axis band, indicating that FeCrUO was composed of a uranyl-like structure in its lattice regardless of its "x"' value. Mssbauer measurements indicated that the Fe in FeUO and FeCrUO were trivalent. Furthermore, FeCrUO lost its symmetry around Fe with increasing electron densities around Fe, as the abundance of Cr increased. These results suggested no significant structural differences between FeUO and CrUO. Thermogravimetric measurements for UO, FeUO, and CrUO showed that the temperature at which FeUO decomposed under an oxidizing condition (approximately 800 C) was significantly lower than the temperature at which the decomposition of CrUO started (approximately 1250 C). Based on these results, we concluded that the decomposition of FeUO was triggered by an "in-crystal" redox reaction, i.e., Fe U Fe U, which would not occur in the CrUO lattice because Cr could never be reduced under the investigated condition. Finally, the existence of Cr in FexCrUO effectively suppressed the decomposition of the FeCrUO crystal, even at a very low Cr content.

Influence of distant scatterer on air kerma measurement in the evaluation of diagnostic X-rays using Monte Carlo simulation

Tominaga, Masahide*; Nagayasu, Yukari*; Sasaki, Motoharu*; Furuta, Takuya; Hayashi, Hiroaki*; Oita, Masataka*; Nishiyama, Yuichi*; Haga, Akihiro*

Radiological Physics and Technology, 14(4), p.381 - 389, 2021/12

https://doi.org/10.1007/s12194-021-00641-3

Due to recent advance of diagnostic radiology, the increase of diagnostic radiation exposure to patient becomes problem. Diagnostic Reference Levels has been released to optimized the radiation exposure to patients in Japan recently. The evaluation of entrance surface dose (ESD) is recommended to assess the dose level for general X-ray examination. The ESD can be easily evaluated by multiplying the backscatter factor of the patient body on the free-in-air air kerma. The air kerma free-in-air value used to estimate ESD may contain X-rays scattered from obstacles located at the time of measurement, which may induce non-minor error in assessments. We therefore studied the influence of scattered X-rays on air kerma measurement under various environments (distances, field sizes, and materials). It was found that the dependence on the X-ray energy and field size was different for different materials. The X-ray contamination can be ignored for all the materials when the distance to the scatterer exceeds 35 cm.

A Multi-technique tomography-based approach for non-invasive characterization of additive manufacturing components in view of vacuum/UHV applications; Preliminary results

Grazzi, F.*; Cialdai, C.*; Manetti, M.*; Massi, M.*; Morigi, M. P.*; Bettuzzi, M.*; Brancaccio, R.*; Albertin, F.*; Shinohara, Takenao; Kai, Tetsuya; et al.

Rendiconti Lincei. Scienze Fisiche e Naturali, 32(3), p.463 - 477, 2021/09

https://doi.org/10.1007/s12210-021-00994-2