Massive Dirac magnons in the three-dimensional honeycomb magnetic oxide FeTiO

Chung, J.-H.*; Kwangwoo, S.*; Yokoo, Tetsuya R.; Ueta, Daichi*; Imai, Masaki; Kim, H.-S.; Kiem, D. H.; Han, M. J.*; Shamoto, Shinichi

Scientific Reports (Internet), 15, p.5978_1 - 5978_10, 2025/02

https://doi.org/10.1038/s41598-025-90478-2

Uncovering the characteristics of plastic-associated biofilm from the inland river system of Mongolia

Battulga, B.; Munkhbat, D.*; Matsueda, Makoto; Atarashi-Andoh, Mariko; Oyuntsetseg, B.*; Koarashi, Jun; Kawahigashi, Masayuki*

Environmental Pollution, 357, p.124427_1 - 124427_10, 2024/09

https://doi.org/10.1016/j.envpol.2024.124427

The occurrence and characteristics of plastic debris in aquatic and terrestrial environments have been extensively studied. However, there is still limited information on the properties and dynamic behavior of plastic-associated biofilms in the environment. In this study, we collected plastic samples from an inland river system in Mongolia and extracted biofilms from the plastics to uncover the characteristics of the biofilms using analytical, isotopic, and thermogravimetric techniques. Mixtures of organic and mineral particles were detected from extracted biofilms, revealing the plastic as a carrier for exogenous substances including contaminants in the river ecosystem. The present study provides insights into the characteristics and environmental behavior of biofilms which are useful to elucidate the impact of plastic-associated biofilms on organic matter and material cycling in the aquatic ecosystems.

Contribution to risk reduction in decommissioning works by the elucidation of basic property of radioactive microparticles (Contract Research); FY2020 Nuclear Energy Science & Technology and Human Resource Development Project

Collaborative Laboratories for Advanced Decommissioning Science; Ibaraki University*

JAEA-Review 2023-021, 112 Pages, 2024/02

JAEA-Review-2023-021.pdf:7.1MB

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 FY2020. 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 FY2018, this report summarizes the research results of the "Contribution to Risk Reduction in Decommissioning Works by the Elucidation of Basic Property of Radioactive Microparticles" conducted from FY2018 to FY2021 (this contract was extended to FY2021). The present study aims to understand the basic properties (size, chemical composition, isotopic composition - including concentration of -emitters, electrostatic properties, and optical properties, etc.) of fine particles composed of silicate with insoluble properties which contain regions of highly concentrated radioactive cesium (Cs) released to the environment by the accident at the Fukushima Daiichi Nuclear Power Station of TEPCO in 2011 March.

On the velocity and frequency of disturbance waves in vertical annular flow with different surface tension and gas-liquid density ratio

Zhang, H.*; Umehara, Yutaro*; Yoshida, Hiroyuki; Mori, Shoji*

International Journal of Heat and Mass Transfer, 211, p.124253_1 - 124253_13, 2023/09

https://doi.org/10.1016/j.ijheatmasstransfer.2023.124253

Effect of gas density and surface tension on liquid film thickness in vertical upward disturbance wave flow

Zhang, H.*; Mori, Shoji*; Hisano, Tsutomu*; Yoshida, Hiroyuki

International Journal of Multiphase Flow, 159, p.104342_1 - 104342_15, 2023/02

https://doi.org/10.1016/j.ijmultiphaseflow.2022.104342

Single crystal growth and magnetic properties of -Mn and -Mn

Onuki, Yoshichika*; Aoki, Dai*; Nakamura, Ai*; Matsuda, Tatsuma*; Nakashima, Miho*; Haga, Yoshinori; Takeuchi, Tetsuya*

Journal of the Physical Society of Japan, 91(6), p.065001_1 - 065001_2, 2022/06

https://doi.org/10.7566/JPSJ.91.065001

Thermodynamic and thermophysical properties of the actinide nitrides

Uno, Masayoshi*; Nishi, Tsuyoshi*; Takano, Masahide

Comprehensive Nuclear Materials, 2nd Edition, Vol.7, p.202 - 231, 2020/08

https://doi.org/10.1016/B978-0-12-803581-8.11749-7

On the thermodynamic and thermophysical properties of the actinide nitrides in Comprehensive Nuclear Materials published by Elsevier as the first edition in 2012, we have revised them by adding some brand-new data. The main topics added are the solid solubility of the actinide nitrides into the zirconium nitride matrix for transmutation fuel, the lattice expansion of actinide nitrides induced by self-irradiation damage, the influence of defects accumulation on thermal conductivity, and the thermal expansion in curium nitride lattice.

Microstructure and texture evolution and ring-tensile properties of recrystallized FeCrAl ODS cladding tubes

Aghamiri, S. M. S.*; Sowa, Takashi*; Ukai, Shigeharu*; Ono, Naoko*; Sakamoto, Kan*; Yamashita, Shinichiro

Materials Science & Engineering A, 771, p.138636_1 - 138636_12, 2020/01

https://doi.org/10.1016/j.msea.2019.138636

Oxide dispersion strengthened (ODS) FeCrAl ferritic steels are being developed as potential accident tolerance fuel cladding materials for the light water reactors (LWRs) due to significant improvement in steam oxidation by alumina forming scale and good mechanical properties up to high temperatures. In this study, the microstructural characteristics and tensile properties of the two FeCrAl ODS cladding tubes with different extrusion temperatures of 1100C and 1150C were investigated during processing conditions. While the hot extruded sample showed micron sized elongated grains with strong -fiber in 110 texture, cold pilger rolling process change the microstructure to submicron/micron size grain structure along with texture evolution to both -fiber (110 texture) and -fiber ({111} texture) via crystalline rotations. Subsequently, final annealing resulted in evolution of microstructure to large grain recrystallized structure starting at recrystallization temperature of 810-850C. Two distinct texture development happened in recrystallized cladding tubes, i.e., only large elongated grains of (110) 211 texture following extrusion temperature of 1100C; and two texture components of (110) 211 and {111} 112 following higher extrusion temperature of 1150C. The different texture development and retarding of recrystallization progress in 1100C-extruded cladding tubes were attributed to higher distribution of oxide particles.

Thermal and mechanical properties of CeO

Suzuki, Kiichi; Kato, Masato; Sunaoshi, Takeo*; Uno, Hiroki*; Carvajal-Nunez, U.*; Nelson, A. T.*; McClellan, K. J.*

Journal of the American Ceramic Society, 102(4), p.1994 - 2008, 2019/04

https://doi.org/10.1111/jace.16055

The fundamental properties of CeO were assessed using a range of experimental techniques. The oxygen potential of CeO was measured by the thermogravimetric technique, and a numerical fit for the oxygen potential of CeO is derived based on defect chemistry. Mechanical properties of CeO were obtained using sound velocity measurement, resonant ultrasound spectroscopy and nanoindentation. The obtained mechanical properties of CeO are then used to evaluate the Debye temperature and Gruneisen constant. The heat capacity and thermal conductivity of CeO were also calculated using the Debye temperature and the Gruneisen constant. Finally, the thermal conductivity was calculated based upon laser flash analysis measurements. This result demonstrates that the thermal conductivity has strong dependence upon material purity.

Crystallographic, magnetic, thermal, and electric transport properties in UPtIn single crystal

Matsumoto, Yuji*; Haga, Yoshinori; Tateiwa, Naoyuki; Yamamoto, Etsuji; Fisk, Z.*

Journal of the Physical Society of Japan, 87(2), p.024706_1 - 024706_4, 2018/02

https://doi.org/10.7566/JPSJ.87.024706