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Sumida, Kazuki; Higaki, Sota*; Sato, Hitoshi*; Tsuru, Daichi*; Miyamoto, Koji*; Okuda, Taichi*; Kuroiwa, Yoshihiro*; Moriyoshi, Chikako*; Takase, Koichi*; Oguchi, Tamio*; et al.
Journal of the Physical Society of Japan, 92(8), p.084706_1 - 084706_6, 2023/08
Times Cited Count:0 Percentile:0.00(Physics, Multidisciplinary)Yamasaki, Atsushi*; Fujiwara, Hidenori*; Tachibana, Shoichi*; Iwasaki, Daisuke*; Higashino, Yuji*; Yoshimi, Chiaki*; Nakagawa, Koya*; Nakatani, Yasuhiro*; Yamagami, Kohei*; Aratani, Hidekazu*; et al.
Physical Review B, 94(11), p.115103_1 - 115103_10, 2016/11
Times Cited Count:17 Percentile:60.70(Materials Science, Multidisciplinary)In this study, we systematically investigate three-dimensional(3D) momentum-resolved electronic structures of Ruddlesden-Popper-type iridium oxides SrIrO using soft-X-ray angle-resolved photoemission spectroscopy (SX-ARPES). Our results provide direct evidence of an insulator-to-metal transition that occurs upon increasing the dimensionality of the IrO-plane structure. This transition occurs when the spin-orbit-coupled = 1/2 band changes its behavior in the dispersion relation and moves across the Fermi energy. By scanning the photon energy over 350 eV, we reveal the 3D Fermi surface in SrIrO and -dependent oscillations of photoelectron intensity in SrIrO. To corroborate the physics deduced using low-energy ARPES studies, we propose to utilize SX-ARPES as a powerful complementary technique, as this method surveys more than one whole Brillouin zone and provides a panoramic view of electronic structures.
Hirayama, Ryoichi*; Uzawa, Akiko*; Takase, Nobuhiro*; Matsumoto, Yoshitaka*; Noguchi, Miho; Koda, Kana*; Ozaki, Masakuni*; Yamashita, Kei*; Li, H.*; Kase, Yuki*; et al.
Mutation Research; Genetic Toxicology And Environmental Mutagenesis, 756(1-2), p.146 - 151, 2013/08
Times Cited Count:24 Percentile:60.71(Biotechnology & Applied Microbiology)Hirayama, Ryoichi*; Uzawa, Akiko*; Matsumoto, Yoshitaka*; Noguchi, Miho; Kase, Yuki*; Takase, Nobuhiro*; Ito, Atsushi*; Koike, Sachiko*; Ando, Koichi*; Okayasu, Ryuichi*; et al.
Radiation Protection Dosimetry, 143(2-4), p.508 - 512, 2011/02
Times Cited Count:14 Percentile:71.64(Environmental Sciences)We studied double-strand breaks (DSB) induction and rejoining in clamped and non-clamped transplanted tumours in mice leg after exposure to 80 keV/m carbon ions and X-rays. The yields of DSB in the tumours were analysed by a static-field gel electrophoresis. The OER of DSB after X-rays was 1.68, and this value was not changed after 1 h rejoining time (1.40). These damages in oxygenated conditions were rejoined 60-70% within 1 h in situ. No difference was found between the exposure to X-rays and carbon ions for the induction and rejoining of DSB. Thus, the values of OER and rejoined fraction after exposure to carbon ions were similar to those after X-rays, and the calculated relative biological effectivenesses of carbon ion were around 1 under both oxygen conditions. The yields of DSB in vivo depend on exposure doses, oxygen conditions and rejoining time, but not on the types of radiation quality.
Nakatsuka, Toru; Ezato, Koichiro; Misawa, Takeharu; Seki, Yohji; Yoshida, Hiroyuki; Dairaku, Masayuki; Suzuki, Satoshi; Enoeda, Mikio; Takase, Kazuyuki
Journal of Nuclear Science and Technology, 47(12), p.1118 - 1123, 2010/12
Times Cited Count:1 Percentile:9.92(Nuclear Science & Technology)In order to perform efficiently the thermal design of the supercritical water reactor (SCWR), it is important to assess the thermal hydraulics in rod bundles of the core. Japan Atomic Energy Agency (JAEA) has been improved the three-dimensional two-fluid model analysis code ACE-3D, which has been developed originally for the two-phase flow thermal hydraulics of light water reactors, to handle the thermal hydraulic properties of water at supercritical region. In the present paper, heat transfer experiments of supercritical water flowing in a vertical annular channel around a heater pin, which was performed at JAEA, were analyzed with the improved ACE-3D to assess the prediction performance of the code. As a result, it was implied that the ACE-3D code may be applicable to prediction of wall temperatures of a single rod that simulates the fuel bundle geometry of SCWR core.
Akimoto, Hajime; Ohshima, Hiroyuki; Kamide, Hideki; Nakagawa, Shigeaki; Ezato, Koichiro; Takase, Kazuyuki; Nakamura, Hideo
Proceedings of 13th International Topical Meeting on Nuclear Reactor Thermal Hydraulics (NURETH-13) (CD-ROM), 7 Pages, 2009/09
Thermal-hydraulics researches at JAEA are performed in many nuclear R&D areas that investigate fusion reactor, fast reactors (FR), high temperature gas cooled reactors (HTGR), and light water reactors (LWRs). These researches are composed of both experimental and analytical efforts. Experimental efforts cover from small-scale fundamental works to large-scale system-integrated tests. Analytical efforts cover both so-called one-dimensional system analysis codes and detailed three-dimensional CFD codes. The thermal-hydraulic phenomena dealt at JAEA cover both normal operation conditions and accident conditions including severe accidents in LWR and FR. The phenomena include single phase flow of water, supercritical water, helium and sodium, two-phase flow of steam-water or sodium-argon, and multi-phase flows encountered in severe accidents. In this paper, we will summarize current status and future directions of thermal-hydraulic researches at JAEA.
Takase, Kazuyuki; Kitamura, Tatsuaki*; Kume, Etsuo; Ichimiya, Koichi*; Komada, Ichiro*
Nihon Kikai Gakkai Kanto Shibu Yamanashi Koenkai (2003) Koen Rombunshu, No.030-4, p.77 - 78, 2003/00
no abstracts in English
Hatanaka, Koichiro; Watari, Shingo; Uchida, Masahiro; Takase, Hiroyasu*; Impey, M. D.*
Materials Research Society Symposium Proceedings, Vol.412, 739- Pages, 1996/00
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Nagae, Daisuke; Takemuara, Makoto*; Ueno, Hideki*; Kameda, Daisuke*; Asahi, Koichiro*; Yoshimi, Akihiro*; Sugimoto, Takashi*; Nagatomo, Takashi*; Kobayashi, Yoshio*; Uchida, Makoto*; et al.
no journal, ,
An electric quadrupole moment ( moment) is sensitive to collective aspects of nuclear structure. In the -moment measurement for unstable nuclei, we employ the -detected nuclear-quadrupole resonance method. In this method, we need to supply resonance frequencies, where denotes the nuclear spin. We have developed a new RF-application system to induced all of the transitions. The application of the frequencies may be pursued in two different ways; the sequential RF pulse method and the mixed-wave RF pulse method. We confirmed the reversal of polarization for the both methods, from measurements of -ray asymmetry change for polarized B. Using this system, the moments of Al have been measured to be mb and mb by the sequential RF pulse method.
Misawa, Takeharu; Nakatsuka, Toru; Yoshida, Hiroyuki; Takase, Kazuyuki; Ezato, Koichiro; Seki, Yohji; Dairaku, Masayuki; Suzuki, Satoshi; Enoeda, Mikio
no journal, ,
Okumura, Masahiko; Akasaka, Koichiro*; Takase, Hiroyasu*; Miyahara, Kaname; Nakayama, Shinichi
no journal, ,
no abstracts in English
Shobu, Takahisa; Urushisaki, Yukinori*; Ichimura, Makoto*; Amaya, Koichi*; Yada, Hiroki; Takase, Kazuyuki; Muramatsu, Toshiharu
no journal, ,
no abstracts in English
Umeki, Hiroyuki; Osawa, Hideaki; Naito, Morimasa; Nakano, Katsushi; Makino, Hitoshi; Miyamoto, Yoichi; Takase, Hiroyasu*; McKinley, I. G.*; Umeda, Koji; Asamori, Koichi; et al.
no journal, ,
no abstracts in English
Takase, Kazuyuki; Misawa, Takeharu; Yoshida, Hiroyuki; Mori, Hideo*; Ezato, Koichiro
no journal, ,
no abstracts in English