Beryllium-7 depositions in Hokuriku, Japan in winter (1991-2021); Factors causing the temporal variation

Yoshida, Keisuke; Kato, Shingo; Okuyama, Shinichi; Ishimori, Yuu; Inoue, Mutsuo*

Journal of Nuclear and Radiochemical Sciences (Internet), 24, p.1 - 12, 2024/08

http://www.radiochem.org/en/paper/JN241/jn24102.pdf

Liquid interfaces related to lanthanide and actinide chemistry studied using vibrational sum frequency generation spectroscopy

Kusaka, Ryoji

Journal of Nuclear and Radiochemical Sciences (Internet), 20, p.28 - 31, 2020/06

http://www.radiochem.org/en/paper/JN201/jn20105.pdf

Roles of d- and f-orbital electrons in the complexation of Eu(III) and Am(III) ions with alkyldithiophosphinic acid and alkylphosphinic acid using scalar-relativistic DFT calculations

Kaneko, Masashi; Watanabe, Masayuki; Miyashita, Sunao*; Nakashima, Satoru*

Journal of Nuclear and Radiochemical Sciences (Internet), 17, p.9 - 15, 2017/03

http://www.radiochem.org/en/paper/JN171/jn17102.pdf

Density functional calculations were applied to the complexation of Eu(III) and Am(III) ions with phosphinic acid (O-donor) and dihiophosphinic acid (S-donor) from the viewpoint of the bonding nature of valence orbitals in metal ion. Two and four conformers for S-donor and O-donor complexes, respectively were optimized. Their stabilization energies by complex formation toward [M(HO)] were estimated. As the result, the energies reproduced the experimental Am(III)/Eu(III) selectivity that O-donor ligand preferably coordinates to Eu(III) ion, whereas S-donor ligand selectively coordinates to Am(III) ion. Focused on the bonding natures of d and f-orbital electrons, it was indicated that the d-orbital electrons in both Eu and Am complexes participate in the covalency as bonding-type nature and have the almost same contribution. Meanwhile, the contribution of the f-orbital electrons was different between Eu and Am complexes and indicated that in the case of S-donor complex, non-bonding type and bonding type contributions were observed for Eu and Am complexes, respectively and in the case of O-donor complex, bonding type and anti-bonding type contributions were observed for Eu and Am complexes, respectively. This result suggested that the bonding natures of d-orbital electrons contribute to the geometrical similarity of molecular structures for Eu and Am complexes and the bonding natures of f-orbital electrons contribute to the difference in the selectivity of Eu and Am ions.

Efficiency calibration of Ge detector for I and Cs in soil samples and a simplified calculation of cascade summing corrections for volume source

Asai, Masato; Kaneya, Yusuke*; Sato, Tetsuya; Tsukada, Kazuaki; Oe, Kazuhiro; Sato, Nozomi; Toyoshima, Atsushi

Journal of Nuclear and Radiochemical Sciences (Internet), 12(1), p.5 - 10, 2012/06

http://www.radiochem.org/paper/JN121/jn12103.pdf

To measure radioactivities in soil contaminated by the accident of the Fukushima Daiichi Nuclear Power Plant, efficiency calibration of Ge detectors for I, Cs, and Cs in volume sources was investigated. -ray detection efficiencies for these nuclei were determined precisely using standard soil samples containing Cs, Cs, Hf, and Zr. These standard sources were prepared by admixing radioactive solutions with soil, and point sources were made from the same solutions to determine their radioactivity concentrations. Cascade summing corrections for rays of Cs in soil samples were evaluated experimentally. To easily calculate the cascade summing corrections for volume sources, we examined a simplified method using averaged efficiencies, and evaluated its validity through a comparison of the calculated correction factors with the experimental ones.