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GeFujiwara, Hidenori*; Nakatani, Yasuhiro*; Aratani, Hidekazu*; Kanai-Nakata, Yuina*; Yamagami, Kohei*; Hamamoto, Satoru*; Kiss, Takayuki*; Sekiyama, Akira*; Tanaka, Arata*; Ebihara, Takao*; et al.
New Physics; Sae Mulli, 73(12), p.1062 - 1066, 2023/12
symmetry for anisotropic 
hybridization in the heavy-fermion superconductor CeNiGeFujiwara, Hidenori*; Nakatani, Yasuhiro*; Aratani, Hidekazu*; Kanai, Yuina*; Yamagami, Kohei*; Hamamoto, Satoru*; Kiss, Takayuki*; Yamasaki, Atsushi*; Higashiya, Atsushi*; Imada, Shin*; et al.
Physical Review B, 108(16), p.165121_1 - 165121_10, 2023/10
Times Cited Count：0 Percentile：0(Materials Science, Multidisciplinary)Urushidate, Tadayuki*; Yoda, Tomoyuki; Otani, Shuichi*; Yamaguchi, Toshio*; Kunii, Nobuaki*; Kuriki, Kazuki*; Fujiwara, Kenso; Niizato, Tadafumi; Kitamura, Akihiro; Iijima, Kazuki
JAEA-Review 2022-023, 8 Pages, 2022/09
JAEA-Review-2022-023.pdf:1.19MB
After the accident of the Fukushima Daiichi Nuclear Power Station, the Japan Atomic Energy Agency has newly set up a laboratory in Fukushima and started measuring radioactivity concentrations of environmental samples. In October 2015, Fukushima Radiation Measurement Group has been accredited the ISO/IEC 17025 standard by the Japan Accreditation Board (JAB) as a testing laboratory for radioactivity analysis (
Cs, 
Cs) based on Gamma-ray spectrometry with germanium semiconductor detectors. The laboratory has measured approximately 60,000 of various environmental samples at the end of March 2022. The laboratory quality control and measurement techniques have been accredited by regular surveillance of JAB. In September 2019, the laboratory renewed accreditation as a testing laboratory for radioactivity analysis.
Yamamura, Sota*; Fujiwara, Kota*; Honda, Kota*; Yoshida, Hiroyuki; Horiguchi, Naoki; Kaneko, Akiko*; Abe, Yutaka*
Physics of Fluids, 34(8), p.082110_1 - 082110_13, 2022/08
Times Cited Count：2 Percentile：41.08(Mechanics)Liquid spreading and atomization due to jet impingement in liquid-liquid systems are considered to be crucial for understanding the cooling behavior of high-temperature molten material in a shallow water pool. This phenomenon takes place when a liquid jet enters a pool filled with other immiscible liquid. The jet spreads radially after impinging on the floor while forming a thin liquid film and atomizing droplets. In this paper, we explain the result to quantify the unsteady three-dimensional behavior of the spreading jet by the employment of 3D-LIF measurements and 3-dimensional reconstruction. Under high flow velocity conditions, the phenomena of hydraulic jump and atomization of the liquid film occurred along with the spreading. To evaluate the spreading behavior, a comparison of the jump radius position of the liquid-liquid system as the representative value was made with the one calculated by the existing theory of a gas-liquid system. As the result, the spreading of the liquid film in the liquid-liquid system was suppressed compared with that in the gas-liquid system. Furthermore, the PTV method was successfully used to measure the velocity boundary layer and velocity profile in the liquid film, which are important factors that affect the spreading mechanism of the liquid film. These results revealed that in liquid-liquid systems, shear stress at the liquid-liquid interface causes a decrease in the flow velocity and suppressed the development of the velocity boundary layer. Also, to evaluate the atomization behavior, the number and diameter distribution of the droplets were measured from the acquired 3-dimensional shape data of the jet. As the result, the number of droplets increased with the flow velocity. Based on these results, we concluded that the spreading of the liquid film is affected by such atomization behavior.
Furuike, Yoshihiko*; Ouyang, D.*; Tominaga, Taiki*; Matsuo, Tatsuhito*; Mukaiyama, Atsushi*; Kawakita, Yukinobu; Fujiwara, Satoru*; Akiyama, Shuji*
Communications Physics (Internet), 5(1), p.75_1 - 75_12, 2022/04
Times Cited Count：4 Percentile：67.44(Physics, Multidisciplinary)Kimura, Fumihito*; Yamamura, Sota*; Fujiwara, Kota*; Yoshida, Hiroyuki; Saito, Shimpei*; Kaneko, Akiko*; Abe, Yutaka*
Nuclear Engineering and Design, 389, p.111660_1 - 111660_11, 2022/04
Times Cited Count：3 Percentile：68.71(Nuclear Science & Technology)O
with electrochemical Li
intercalationMurase, Satoshi*; Yoshikawa, Yumi*; Fujiwara, Kosuke*; Fukada, Yukimasa*; Teranishi, Takashi*; Kano, Jun*; Fujii, Tatsuo*; Inada, Yasuhiro*; Katayama, Misaki*; Yoshii, Kenji; et al.
Journal of Physics and Chemistry of Solids, 162, p.110468_1 - 110468_6, 2022/03
Times Cited Count：0 Percentile：0(Chemistry, Multidisciplinary)We report a trial of the valence control for mixed valence iron triangular oxide YbFeO in order to develop an effective technique to control the frustration of charges in strongly correlated electron systems. The electro-chemical doping of Li into YbFeO was examined on the cell type sample similar to the Li-ion secondary battery cell. Systematic change of the lattice constant, Fe-Fe and Fe-Yb distance were observed with Li doping. Maximum value of the doping was over 300 mAh/g. An EXAFS experiment indicated that Li positioned between Yb octahedron layer (U-layer) and Fe-bipyramidal layer (W-layer). However, detailed change of iron valence state of YbFeO was not clearly observed because of the superimpose of the signal from iron metal nano particles in XANES observation. The results indicate that the electrochemical method might be one of the potential technique to control the frustration of charges in YbFeO.
Horiguchi, Naoki; Yoshida, Hiroyuki; Yamamura, Sota*; Fujiwara, Kota*; Kaneko, Akiko*; Abe, Yutaka*
Proceedings of 19th International Topical Meeting on Nuclear Reactor Thermal Hydraulics (NURETH-19) (Internet), 14 Pages, 2022/03
Ishii, Mamoru*; Shiota, Daiko*; Tao, Chihiro*; Ebihara, Yusuke*; Fujiwara, Hitoshi*; Ishii, Takako*; Ichimoto, Kiyoshi*; Kataoka, Ryuho*; Koga, Kiyokazu*; Kubo, Yuki*; et al.
Earth, Planets and Space (Internet), 73(1), p.108_1 - 108_20, 2021/12
Times Cited Count：8 Percentile：57.39(Geosciences, Multidisciplinary)We surveyed the relationship between the scale of space weather events and their occurrence rate in Japan and we discussed the social impact of these phenomena during the Project for Solar-Terrestrial Environment Prediction (PSTEP). The information was compiled for domestic users of space weather forecasts for appropriate preparedness against space weather disasters. This paper gives a comprehensive summary of the survey, focusing on the fields of electricity, satellite operations, communication and broadcasting, satellite positioning usage, aviation, human space activity, and daily life on the Earth's surface, using the cutting-edge knowledge of space weather. Quantitative estimations of the economic impact of space weather events on electricity and aviation are also given.
Kusano, Kanya*; Ichimoto, Kiyoshi*; Ishii, Mamoru*; Miyoshi, Yoshizumi*; Yoden, Shigeo*; Akiyoshi, Hideharu*; Asai, Ayumi*; Ebihara, Yusuke*; Fujiwara, Hitoshi*; Goto, Tadanori*; et al.
Earth, Planets and Space (Internet), 73(1), p.159_1 - 159_29, 2021/12
Times Cited Count：6 Percentile：51.19(Geosciences, Multidisciplinary)The PSTEP is a nationwide research collaboration in Japan and was conducted from April 2015 to March 2020, supported by a Grant-in-Aid for Scientific Research on Innovative Areas from the Ministry of Education, Culture, Sports, Science and Technology of Japan. It has made a significant progress in space weather research and operational forecasts, publishing over 500 refereed journal papers and organizing four international symposiums, various workshops and seminars, and summer school for graduate students at Rikubetsu in 2017. This paper is a summary report of the PSTEP and describes the major research achievements it produced.
Otsuka, Yusuke*; Kanazawa, Naoya*; Hirayama, Motoaki*; Matsui, Akira*; Nomoto, Takuya*; Arita, Ryotaro*; Nakajima, Taro*; Hanashima, Takayasu*; Ukleev, V.*; Aoki, Hiroyuki; et al.
Science Advances (Internet), 7(47), p.eabj0498_1 - eabj0498_9, 2021/11
Times Cited Count：7 Percentile：40.96(Multidisciplinary Sciences)
Li
TiO
(x = 0.13) studied by quasielastic neutron scatteringMatsuura, Masato*; Fujiwara, Yasuyuki*; Moriwake, Hiroki*; Ohara, Koji*; Kawakita, Yukinobu
Physical Review B, 104(9), p.094305_1 - 094305_7, 2021/09
Times Cited Count：5 Percentile：44.86(Materials Science, Multidisciplinary)Fujiwara, Hidenori*; Umetsu, Rie*; Kuroda, Fumiaki*; Miyawaki, Jun*; Kashiuchi, Toshiyuki*; Nishimoto, Kohei*; Nagai, Kodai*; Sekiyama, Akira*; Irizawa, Akinori*; Takeda, Yukiharu; et al.
Scientific Reports (Internet), 11(1), p.18654_1 - 18654_9, 2021/09
Times Cited Count：0 Percentile：0(Multidisciplinary Sciences)Dohi, Terumi; Omura, Yoshihito*; Yoshimura, Kazuya; Sasaki, Takayuki*; Fujiwara, Kenso; Kanaizuka, Seiichi*; Nakama, Shigeo; Iijima, Kazuki
PLOS ONE (Internet), 16(5), p.e0251828_1 - e0251828_16, 2021/05
Times Cited Count：6 Percentile：41.49(Multidisciplinary Sciences)Takeda, Tetsuaki*; Inagaki, Yoshiyuki; Aihara, Jun; Aoki, Takeshi; Fujiwara, Yusuke; Fukaya, Yuji; Goto, Minoru; Ho, H. Q.; Iigaki, Kazuhiko; Imai, Yoshiyuki; et al.
High Temperature Gas-Cooled Reactors; JSME Series in Thermal and Nuclear Power Generation, Vol.5, 464 Pages, 2021/02
As a general overview of the research and development of a High Temperature Gas-cooled Reactor (HTGR) in JAEA, this book describes the achievements by the High Temperature Engineering Test Reactor (HTTR) on the designs, key component technologies such as fuel, reactor internals, high temperature components, etc., and operational experience such as rise-to-power tests, high temperature operation at 950
C, safety demonstration tests, etc. In addition, based on the knowledge of the HTTR, the development of designs and component technologies such as high performance fuel, helium gas turbine and hydrogen production by IS process for commercial HTGRs are described. These results are very useful for the future development of HTGRs. This book is published as one of a series of technical books on fossil fuel and nuclear energy systems by the Power Energy Systems Division of the Japan Society of Mechanical Engineers.
FeO
with distributed equivalent circuit modelFukada, Yukimasa*; Fukuyama, Ryota*; Fujiwara, Kosuke*; Yoshii, Kenji; Shigematsu, Kei*; Azuma, Masaki*; Ikeda, Naoshi*
Journal of the Physical Society of Japan, 90(2), p.024710_1 - 024710_6, 2021/02
Times Cited Count：2 Percentile：30.35(Physics, Multidisciplinary)We report an analysis of the dielectric glasslike state of the spin- and charge-ordered system LuFeO, which has structural and physical properties analogous to those of the electronic ferroelectrics 
FeO (: rare earth). Aging and memory effects of resistivity were found in the electric impedance response. We performed a numerical analysis with equivalent electric circuits that have a logarithmic Gaussian distribution of resistance and capacitance. The distribution parameters well explained the glassy nature of the electric and dielectric properties between 100 and 200 K and the distribution variations of charge- and magnetic-ordered domains underlying the glass nature.
Sr and Cs in soils near the Fukushima Daiichi Nuclear Power StationSasaki, Takayuki*; Matoba, Daisuke*; Dohi, Terumi; Fujiwara, Kenso; Kobayashi, Taishi*; Iijima, Kazuki
Journal of Radioanalytical and Nuclear Chemistry, 326(1), p.303 - 314, 2020/10
Times Cited Count：3 Percentile：35.51(Chemistry, Analytical)
Sb
uncovered by soft X-ray magnetic circular dichroismSaito, Yuji; Fujiwara, Hidenori*; Yasui, Akira*; Kadono, Toshiharu*; Sugawara, Hitoshi*; Kikuchi, Daisuke*; Sato, Hideyuki*; Suga, Shigemasa*; Yamasaki, Atsushi*; Sekiyama, Akira*; et al.
Physical Review B, 102(16), p.165152_1 - 165152_8, 2020/10
Times Cited Count：1 Percentile：6.04(Materials Science, Multidisciplinary)Tachi, Yukio; Sato, Tomofumi*; Akagi, Yosuke*; Kawamura, Makoto*; Nakane, Hideji*; Terashima, Motoki; Fujiwara, Kenso; Iijima, Kazuki
Science of the Total Environment, 724, p.138098_1 - 138098_11, 2020/07
Times Cited Count：13 Percentile：57.17(Environmental Sciences)To understand and predict radiocesium transport behaviors in the environment, highly contaminated sediments from Ukedo and Odaka rivers around the Fukushima Daiichi Nuclear Power Plant were investigated systematically focusing on key factors controlling radiocesium sorption and fixation, including particle size, clay mineralogy and organic matter.
Tachi, Yukio; Sato, Tomofumi*; Takeda, Chizuko*; Ishidera, Takamitsu; Fujiwara, Kenso; Iijima, Kazuki
Science of the Total Environment, 724, p.138097_1 - 138097_10, 2020/07
Times Cited Count：9 Percentile：43.42(Environmental Sciences)To understand and predict radiocesium transport behaviors in the environment, sorption and fixation behaviors of radiocesium on river sediments from Ukedo and Odaka rivers around the Fukushima Daiichi Nuclear Power Plant were investigated systematically focusing on Cs sorption and fixation mechanisms and their relationship with Cs concentrations and sediment properties including clay mineralogy and organic matter.
