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Haku, Satoshi*; Tashiro, Takaharu*; Nakayama, Hiroyasu*; Ieda, Junichi; Entani, Shiro; Sakai, Seiji; Ando, Kazuya*
Applied Physics Express, 8(7), p.073009_1 - 073009_3, 2015/07
Times Cited Count:5 Percentile:18.73(Physics, Applied)We found that the spin pumping in a NiFe/Pt bilayer is strongly suppressed by inserting single-layer graphene (SLG) at the interface. The spin pumping in the NiFe/Pt bilayer enhances the magnetization damping of the ferromagnetic layer, which is quantified from microwave frequency dependence of ferromagnetic resonance linewidth. We show that the enhancement of the magnetization damping due to the spin pumping disappears in a NiFe/SLG/Pt trilayer. This result indicates that the spin pumping is blocked by the atomic monolayer, demonstrating the crucial role of the interfacial short-range spin-exchange coupling in the spin pumping in metallic systems.
Otomo, Manabu; Tsuchida, Yuya*; Muraya, Naoki*; Yanase, Takashi*; Sakai, Seiji; Yonezawa, Tetsu*; Nagahama, Taro*; Hasegawa, Tetsuya*; Shimada, Toshihiro*
Journal of Physical Chemistry C, 117(22), p.11555 - 11561, 2013/06
Times Cited Count:2 Percentile:8.76(Chemistry, Physical)We report in-plane orientation control of newly developed high-mobility organic semiconductor: 2,7-diphenyl[1]benzothieno[3,2-][1]benzothiophene (DPh-BTBT). As previously reported on monolayer pentacene, it was revealed that bunched steps on vicinal Si(111) with bismuth termination break the surface symmetry and reduce three-fold symmetry of DPh-BTBT grains into quasi-single orientation. Interestingly, the critical step height necessary for the orientation control was different from that of pentacene. We examined several mechanisms of orientation control and concluded that the facet nano structure fabricated by step bunching is working as an anisotropic template. We will also show the wettability control of bismuth terminated silicon surface and show that the growth mode of DPh-BTBT is dependent on the surface nanostructure of Bi-Si.
Nishizawa, Hidetoshi; Fukaya, Hiroyuki; Sonoda, Takashi; Sakazume, Yoshinori; Shimizu, Kaori; Haga, Takahisa; Sakai, Yutaka*; Akutsu, Hideyuki*; Niitsuma, Yasushi; Inoue, Takeshi; et al.
JAEA-Technology 2006-007, 24 Pages, 2006/03
Analysis of the uranyl nitrate solution fuel is carried out at the analytical laboratory of NUCEF(Nuclear Fuel Cycle Engineering Research Facility), which provides essential data for operation of STACY(Static Experiment Critical Facility), TRACY(Transient Experiment Critical Facility)and the fuel treatment system. Analyzed in FY 2004 were uranyl nitrate solution fuel samples taker before and after experiments of STACY and TRACY, samples for the preparation of uranyl nitrate solution fuel, and samples for nuclear material accountancy purpose. Also analyzed were the samples from raffinate treatment and its preliminary tests. The raffinate was generated, since FY 2000, during preliminary experiments on U/Pu extraction-pulification to fix the operation condition to prepare plutonium solution fuel to be used for criticality experiments at STACY. The total number of the samples analyzed in FY 2004 was 160. This report summarizes works related to the analysis and management of the analytical laboratory in the FY 2004.
Ono, Masao; Huang, X. S.*; Shibata, Yasuhiro*; Iguchi, Yusuke*; Sakai, Seiji; Maekawa, Masaki; Chen, Z. Q.*; Osakabe, Toyotaka; Kawasuso, Atsuo; Naramoto, Hiroshi*; et al.
Proceedings of 1st International Conference on Diffusion in Solids and Liquids (DSL 2005), p.531 - 533, 2005/07
Recently, we formed atomic-scale graded structures in some miscible alloys and observed the decomposition in BiPb intermetallic compound by sedimentation of atoms under strong gravitational field. In this study, we measured positron lifetime of centrifuged BiPb, to which the composition change was very small as it was treated at low temperature. It was found that the positron lifetime became longer than that of starting state. This indicated that the point defects (vacancy or divacancy) increased in the sample by centrifugal treatment. We are now investigating the relationship between increase in point defects and sedimentation of atoms.
Shimizu, Kaori; Gunji, Kazuhiko*; Haga, Takahisa*; Fukaya, Hiroyuki; Sonoda, Takashi; Sakazume, Yoshinori; Sakai, Yutaka*; Akutsu, Hideyuki; Niitsuma, Yasushi*; Inoue, Takeshi; et al.
JAERI-Tech 2004-078, 27 Pages, 2005/02
Analysis of the uranyl nitrate solution fuel are carried out at the analytical laboratory, NUCEF (the Nuclear Fuel Cycle Engineering Research Facility), which provide essential data for the operations of STACY (the Static Experiment Critical Facility), TRACY (the Transient Experiment Critical Facility) and the fuel treatment system.In the FY 2003, analysis of the uranyl nitrate solution fuel from STACY/TRACY on its pre- and post-operations, analysis of the uranyl nitrate solution under preparation stage for the fuel and analysis for nuclear material accountancy purpose, have been conducted. In addition, analysis on the third U/Pu extraction/separation tests among the preliminary tests to confirm adjustment condition of plutonium solution fuel for its further use at STACY from 2000, and analysis on the experiments to treat extraction waste, were conducted. A total number of analytical samples in the FY 2003 were 156.This report summarizes works related to the analysis and management of the analytical laboratory in the FY 2003.
Sakai, Yutaka; Gunji, Kazuhiko; Haga, Takahisa*; Fukaya, Hiroyuki; Sonoda, Takashi; Sakazume, Yoshinori; Akutsu, Hideyuki; Niitsuma, Yasushi; Shirahashi, Koichi; Sato, Takeshi
JAERI-Tech 2004-006, 25 Pages, 2004/02
Analyses of the uranyl nitrate solution fuel are carried out at the analytical laboratory, NUCEF (the Nuclear Fuel Cycle Engineering Research Facility), which provide essential data for the operations of STACY (the Static Experiment Critical Facility), TRACY (the Transient Experiment Critical Facility) and the fuel treatment system. In the FY 2002, analyses of the uranyl nitrate solution fuel from STACY/TRACY on its pre- and post-operations, analyses of the uranyl nitrate solution under preparation stage for the fuel and analyses for nuclear material accountancy purpose, have been conducted. In addition, analyses on the preliminary tests to confirm adjustment condition of plutonium solution fuel for its further use at STACY, and analyses on the americium extraction/separation tests to provide americium for the research on high temperature chemistry of TRU, were conducted. A total number of analytical samples in the FY 2002 were 275. This report summarizes works related to the analyses and management of the analytical laboratory in the FY 2002.
Haga, Takahisa*; Gunji, Kazuhiko; Fukaya, Hiroyuki; Sonoda, Takashi; Sakazume, Yoshinori; Sakai, Yutaka; Niitsuma, Yasushi; Togashi, Yoshihiro; Miyauchi, Masakatsu; Sato, Takeshi; et al.
JAERI-Tech 2004-005, 54 Pages, 2004/02
Criticality experiments using uranyl nitrate solution fuel are being conducted at STACY (the Static Experiment Critical Facility) and TRACY (the Transient Experiment Critical Facility) in NUCEF (the Nuclear Fuel Cycle Safety Engineering Research Facility). Chemical analyses of the solution have been carried out to take necessary data for criticality experiments, for treatment and control of the fuel, and for safeguards purpose at the analytical laboratory placed in NUCEF. About 300 samples are analyzed annually that provide various kinds of data, such as uranium concentration, isolation acid concentration, uranium isotopic composition, concentration of fission product (FP) nuclides, tri-butyl phosphoric acid (TBP) concentration, impurities in the solution fuel and so on. This report summarizes the analytical methods and quality management of the analysis for uranyl nitrate solution relating to the criticality experiments.
Sakazume, Yoshinori; Gunji, Kazuhiko; Haga, Takahisa*; Fukaya, Hiroyuki; Sonoda, Takashi; Sakai, Yutaka; Niitsuma, Yasushi; Shirahashi, Koichi; Sato, Takeshi
JAERI-Tech 2002-073, 25 Pages, 2002/09
Analytical results of uranyl nitrate solution are essential data for the operation of the Static Experiment Critical Facility (STACY), the Transient Experiment Critical Facility (TRACY) and the fuel treatment system in the Nuclear Fuel Cycle Safety Engineering Research Facility (NUCEF). Analytical works were carried out for the determination of fuel characteristics before and after criticality experiments, fuel preparation and nuclear material accountancy in FY. 2001. Moreover,as to preparation of critical experiments at STACY, plutonium preliminary tests were carried out to confirm the treatment condition (characteristics of the dissolution of the mixed oxide (MOX) powder and the extraction & separation for uranium / plutonium) of plutonium nitrate solution. Analytical works were carried out on the preliminary tests. A total number of analytical samples in FY. 2001 were 322 samples.This report summarizes the data on analytical works in FY.2001.
Shimono, Masato*; Motoshima, Takayuki*; Ijiri, Yuji*; Otsu, Hiroyasu*; Sakai, Ryosuke*; Sakai, Kazuo*; Sato, Toshinori; Mikake, Shinichiro
no journal, ,
It is considered that the uncertainty of construction cost due to geological heterogeneity is quite large. Therefore, it is crucial to make a long-term consistent budget plan for a construction period of tens years and to have engineering strategies for reducing a total budget. In this study, a risk management approach for construction in a heterogeneous fractured rock is developed. In this approach, methodologies of calculating construction costs for excavating drifts and taking countermeasures at high-hydrostatic pressured fracture zones in a heterogeneous rock are established. The cost for excavating drift is calculated from the heterogeneity of rock strength estimated from a geostatistical modeling approach. The cost for taking countermeasures is calculated from the heterogeneity of large fracture zone estimated from a probabilistic discrete fracture network modeling approach. In addition, a risk for a construction is assessed by a risk cost curve commonly used in the financial business.
Otomo, Manabu; Tsuchida, Yuya*; Sakai, Seiji; Hasegawa, Tetsuya*; Shimada, Toshihiro*
no journal, ,
no abstracts in English
Entani, Shiro; Matsumoto, Yoshihiro; Otomo, Manabu; Sakuraba, Yuya*; Avramov, P.; Naramoto, Hiroshi*; Takanashi, Koki; Sakai, Seiji
no journal, ,
Sakai, Seiji; Matsumoto, Yoshihiro; Entani, Shiro; Otomo, Manabu; Sorokin, B. P.*; Avramov, P.; Naramoto, Hiroshi*; Sakuraba, Yuya*; Takanashi, Koki
no journal, ,
no abstracts in English