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Murase, Kiyoka*; Kataoka, Ryuho*; Nishiyama, Takanori*; Nishimura, Koji*; Hashimoto, Taishi*; Tanaka, Yoshimasa*; Kadokura, Akira*; Tomikawa, Yoshihiro*; Tsutsumi, Masaki*; Ogawa, Yasunobu*; et al.
Journal of Space Weather and Space Climate (Internet), 12, p.18_1 - 18_16, 2022/06
Times Cited Count:0 Percentile:24.42(Astronomy & Astrophysics)We identified two energetic electron precipitation (EEP) events during the growth phase of moderate substorms and estimated the mesospheric ionization rate for an EEP event for which the most comprehensive dataset from ground-based and space-born instruments was available. The mesospheric ionization signature reached below 70 km altitude and continued for ~15 min until the substorm onset, as observed by the PANSY radar and imaging riometer at Syowa Station in the Antarctic region. We also used energetic electron flux observed by the Arase and POES 15 satellites as the input for the air-shower simulation code PHITS to quantitatively estimate the mesospheric ionization rate. Combining the cutting-edge observations and simulations, we shed new light on the space weather impact of the EEP events during geomagnetically quiet times, which is important to understand the possible link between the space environment and climate.
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:52.8(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.
Kataoka, Noriyuki*; Tanaka, Masashi*; Hosoda, Wataru*; Taniguchi, Takumi*; Fujimori, Shinichi; Wakita, Takanori*; Muraoka, Yuji*; Yokoya, Takashi*
Journal of Physics; Condensed Matter, 33(3), p.035501_1 - 035501_6, 2021/01
Times Cited Count:4 Percentile:34.98(Physics, Condensed Matter)Kataoka, Ryuho*; Nishiyama, Takanori*; Tanaka, Yoshimasa*; Kadokura, Akira*; Uchida, Herbert Akihito*; Ebihara, Yusuke*; Ejiri, Mitsumu*; Tomikawa, Yoshihiro*; Tsutsumi, Masaki*; Sato, Kaoru*; et al.
Earth, Planets and Space (Internet), 71(1), p.9_1 - 9_10, 2019/12
Times Cited Count:7 Percentile:40.92(Geosciences, Multidisciplinary)Transient ionization of the mesosphere was detected at around 65 km altitude during the isolated auroral expansion occurred at 2221-2226 UT on June 30, 2017. A general-purpose Monte Carlo particle transport code PHITS suggested that significant ionization is possible in the middle atmosphere due to auroral X-rays from the auroral electrons of 10 keV.
Kataoka, Takashi*; Sakamoto, Yuta*; Yamazaki, Yo*; Singh, V. R.*; Fujimori, Atsushi*; Takeda, Yukiharu; Okochi, Takuo*; Fujimori, Shinichi; Okane, Tetsuo; Saito, Yuji; et al.
Solid State Communications, 152(9), p.806 - 809, 2012/05
Times Cited Count:19 Percentile:60.56(Physics, Condensed Matter)no abstracts in English
Kataoka, Takashi*; Kobayashi, Masaki*; Sakamoto, Yuta*; Song, G. S.*; Fujimori, Atsushi*; Chang, F.-H.*; Lin, H.-J.*; Huang, D. J.*; Chen, C. T.*; Okochi, Takuo*; et al.
Journal of Applied Physics, 107(3), p.033718_1 - 033718_7, 2010/02
Times Cited Count:53 Percentile:85.88(Physics, Applied)Kobayashi, Masaki*; Song, G.-S.*; Kataoka, Takashi*; Sakamoto, Yuta*; Fujimori, Atsushi; Okochi, Takuo*; Takeda, Yukiharu; Okane, Tetsuo; Saito, Yuji; Yamagami, Hiroshi; et al.
Journal of Applied Physics, 105(12), p.122403_1 - 122403_4, 2009/06
Times Cited Count:11 Percentile:45.02(Physics, Applied)Hamada, Nobuyuki*; Kataoka, Keiko*; Sora, Sakura*; Hara, Takamitsu*; Omura, Motoko*; Funayama, Tomoo; Sakashita, Tetsuya; Nakano, Takashi*; Kobayashi, Yasuhiko
Radiotherapy and Oncology, 89(2), p.227 - 230, 2008/11
Times Cited Count:9 Percentile:31.78(Oncology)Song, G.*; Kobayashi, Masaki*; Hwang, J. I.*; Kataoka, Takashi*; Takizawa, Masaru*; Fujimori, Atsushi; Okochi, Takuo; Takeda, Yukiharu; Okane, Tetsuo; Saito, Yuji; et al.
Japanese Journal of Applied Physics, 47(9), p.7113 - 7116, 2008/09
Times Cited Count:3 Percentile:14.43(Physics, Applied)Song, G.*; Kobayashi, Masaki*; Hwang, J. I.*; Kataoka, Takashi*; Takizawa, Masaru*; Fujimori, Atsushi; Okochi, Takuo; Takeda, Yukiharu; Okane, Tetsuo; Saito, Yuji; et al.
Physical Review B, 78(3), p.033304_1 - 033304_4, 2008/07
Times Cited Count:8 Percentile:37.4(Materials Science, Multidisciplinary)Ishimori, Kenichiro*; Watanabe, Masayuki; Kimura, Takaumi; Yaita, Tsuyoshi; Yamada, Takashi*; Kataoka, Yumiko*; Shinoda, Satoshi*; Tsukube, Hiroshi*
Chemistry Letters, 34(8), p.1112 - 1113, 2005/08
Times Cited Count:13 Percentile:44.83(Chemistry, Multidisciplinary)Stereochemical substitution on tripod ligand significantly offered efficient separation of trivalent actinides from trivalent lanthanides. Liquid-liquid extraction using chiral tris(2-pyridylmethyl)amine ligands as an extractant exhibited high efficiency and selectivity for trivalent actinides. A combination of chiral ligand and 2-bromodecanoic acid further enhanced extraction performance for trivalent actinides.
Mori, Masahiro; Shoji, Teruaki; Araki, Masanori; Saito, Keiji*; Senda, Ikuo; Omori, Junji*; Sato, Shinichi*; Inoue, Takashi; Ono, Isamu*; Kataoka, Takahiro*; et al.
Nihon Genshiryoku Gakkai-Shi, 44(1), p.16 - 89, 2002/01
no abstracts in English
Shimomura, Yasuo; Tsunematsu, Toshihide; Yamamoto, Shin; Maruyama, So; Mizoguchi, Tadanori*; Takahashi, Yoshikazu; Yoshida, Kiyoshi; Kitamura, Kazunori*; Ioki, Kimihiro*; Inoue, Takashi; et al.
Purazuma, Kaku Yugo Gakkai-Shi, 78(Suppl.), 224 Pages, 2002/01
no abstracts in English
Fusaeda, Shigeki*; Yanagisawa, Ichiro*; Kataoka, Shinichi*; Shimada, Takashi*; *; *; *
PNC TJ1216 98-007, 46 Pages, 1998/02
None
Fusaeda, Shigeki*; Yanagisawa, Ichiro*; Kataoka, Shinichi*; Shimada, Takashi*; *; *; *
PNC TJ1216 98-006, 673 Pages, 1998/02
None
Kataoka, Shinichi*; Kitao, Hideo*; Tachikawa, Hirokazu*; Shimada, Takashi*; Maeda, Kazuto*; Nemoto, Kazuaki*; Yanagisawa, Ichiro*
PNC TJ1216 98-002, 676 Pages, 1998/02
None
Kataoka, Takashi*; Sakamoto, Yuta*; Yamazaki, Yo*; Fujimori, Atsushi; Takeda, Yukiharu; Okochi, Takuo; Okane, Tetsuo; Saito, Yuji; Yamagami, Hiroshi
no journal, ,
Recently, transition-metal phthalocyanines (Pc) have attracted great interest in many fields of science and technology because of the structural similarities to bio-molecules, their remarkable thermal stability and chemical inertness. One of the most interesting investigations of transition-metal Pc involves their magnetic properties. At low temperature (10 K), the ferromagnetism in -type polycrystals of manganese phthalocyanine (MnPc) has been reported. We have investigated the electronic structure and magnetic interaction in -type polycrystals of the MnPc using X-ray magnetic circular dichroism (XMCD). The XMCD results suggest that the inter-molecular p-d hybridization occurs in the -type polycrystals of MnPc molecules. We will discuss correlation between the inter-molecular interaction and the ferromagnetic coupling in the MnPc molecules.
Tashiro, Shinsuke; Matsumoto, Tetsuya; Kataoka, Osamu; Amano, Yuki; Abe, Hitoshi; Yamane, Yuichi; Yoshida, Kazuo; Ishikawa, Jun; Uchiyama, Gunzo; Ueda, Yoshinori*; et al.
no journal, ,
Measurements on the release ratios of aerial radioactive materials from mocked fuel reprocessing liquid waste under its boiling to dryness process were performed using labo-scaled experiments. Test sample, dissolved 27 elements into nitric acid and arranged to 2M acidity, was heated up to 300 C under the constant air ventilation. Steam, gaseous and airborne materials were collected or absorbed at the condenser, the air filter and the washing bottles. The accumulated release ratios of mocked FP elements from samples were determined using ICP-MS. From the accumulated release ratios determined from the condensed samples, the major release of Cs and Ru could be involved the release of mist and gaseous RuO, respectively. Besides, accumulated release ratios of Ru was about 10 to 1000 times higher than Cs, differed from the literature using fuel reprocessing liquid waste. Its differences could be influenced the nitrous acid, which was reduced the generation of RuO.
Tashiro, Shinsuke; Matsumoto, Tetsuya; Kataoka, Osamu; Amano, Yuki; Abe, Hitoshi; Yamane, Yuichi; Yoshida, Kazuo; Ishikawa, Jun; Uchiyama, Gunzo; Ueda, Yoshinori*; et al.
no journal, ,
The release behavior of radioactive materials from high-level radioactive liquid wastes (HLW) from reprocessing plants under an accidents of boiling to dryness of HLW condition has been studied. The influences of FP concentration in the simulated HLW on the release ratio of FP from the waste were measured in the laboratory-scaled experiments using non-radioactive simulated HLW which was prepared by dissolving 27 FP elements into nitric acid and adjusted to 2 M acidity. The simulated HLW was heated up to 300C under the constant air ventilation condition. The accumulated release ratios of FP elements from samples were determined using ICP-MS analysis. It was found that the accumulated release ratio of Ru was decreased with the increase of the initial Ru concentration in the simulated HLW. However, those of Cs and Nd were not influenced by the initial concentrations of them.
Sato, Tatsuhiko; Ishii, Mamoru*; Kataoka, Ryuho*; Kubo, Yuki*; Minoshima, Takashi*; Miyoshi, Yoshizumi*; Nagamatsu, Aiko*; Shiota, Daiko*; Takashima, Takeshi*; Yasuda, Hiroshi*
no journal, ,
Forecast of radiation doses for astronauts as well as aircrews due to the exposure to solar energetic particles (SEP) is one of the greatest challenges in space weather research. In last 5 years, we have developed a WArning System for AVIation Exposure to Solar energetic particles: WASAVIES. In this system, the SEP fluxes incident to the atmosphere are calculated by physics-based models, and they are converted to radiation doses using a database developed on the basis of air-shower simulation. However, it takes approximately 2.5 hours to determine the parameters used in the physics-based models after the detection of GLEs, and thus, the current WASAVIES cannot predict doses during the peak of GLEs. Therefore, we are trying to reduce the time for evaluating the parameters, as well as to develop a nowcast system for the radiation dose due to SEP exposure, under the framework of Project for Solar-Terrestrial Environment Prediction (PSTEP) in Japan. A brief outline of WASAVIES together with our future strategy will be presented at the meeting.