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Hiroki, Akihiro; Yamashita, Shinichi; Sato, Yuichi*; Nagasawa, Naotsugu; Taguchi, Mitsumasa
Journal of Physics; Conference Series, 444, p.012028_1 - 012028_4, 2013/06
Times Cited Count:10 Percentile:91.72(Physics, Multidisciplinary)Polymer gel dosimeters consisting of less toxic methacrylate-type monomers such as 2-hydroxyethyl methacrylate (HEMA) and polyethylene glycol 400 dimethacrylate (9G) with hydroxypropyl cellulose (HPC) gel were prepared. We investigated the effect of monomer compositions on the dose response of the polymer gel dosimeter. The HPC gels as a matrix for the polymer gel dosimeter were obtained by electron beam irradiation to 20wt% of HPC aqueous solution. The dried HPC gels were immersed into mixed monomer solutions, and then the swollen gels were vacuum-packed to prepare the polymer gel dosimeters. The polymer gel dosimeters showed cloudiness by exposing to Co -ray, in which the cloudiness increased with the dose up to 10 Gy. At the same dose, the increase in the cloudiness appeared with increasing concentration of 9G. It was found that the dose response depended on the composition ratio between HEMA and 9G.
Tominaga, Taiki; Takata, Shinichi; Suzuki, Junichi*; Shinohara, Takenao; Oku, Takayuki; Nakatani, Takeshi; Inamura, Yasuhiro; Suzuya, Kentaro; Aizawa, Kazuya; Arai, Masatoshi; et al.
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no abstracts in English
Takata, Shinichi; Suzuki, Junichi*; Shinohara, Takenao; Oku, Takayuki; Tominaga, Taiki; Nakatani, Takeshi; Inamura, Yasuhiro; Ito, Takayoshi*; Iwase, Hiroki*; Oishi, Kazuki*
no journal, ,
The small and wide angle neutron scattering instrument, TAIKAN, was installed on BL15 in the Materials and Life Science Experimental Facility (MLF) of J-PARC. The beam commissioning was started in January 2012, and Users program was started in March 2012. TAIKAN is designed for efficient measurement in wide-q range of 0.005-10[]. We measured three typical proteins of Myoglobin(Mb), -Lactoglobulin (LG), and Hemoglobin(Hb) in solution by using TAIKAN, in order to verify the performance of wide-q range. The internal structure of Mb and LG is Helix-rich and -sheet-rich, respectively. We will present the result of comparing measuring data with calculation profiles and the performance of TAIKAN.
Takeda, Masayasu; Suzuki, Junichi*
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Zhao, Y.; Koizumi, Satoshi; Rikukawa, Masahiro*; Yoshida, Miru*
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Koizumi, Satoshi; Putra, A.; Yamaguchi, Daisuke; Zhao, Y.
no journal, ,
In order to visualize water distribution in an operating fuel cell, we combined two different methods using neutron as a probe, i.e., a combined method of small-angle & ultra-small-angle scattering (SANS) and radiography imaging. SANS observes water distribution in a membrane electrolyte assembly (MEA), whereas radiography observes bulk water appeared in a gas flow channel (so called "flooding"). The polymer electrolyte fuel cell (PEFC) was specially designed suitable for small-angle neutron scattering by replacing materials with aluminum in order to decrease background scattering. We employed hydrogen gas (H) and deuterated gas (D) as a fuel for operation. With exchange of H and D, we aim to perform a contrast variation as for polyelectrolyte film (Nafion). When D gas is used as a fuel, DO is produced at the cathode and diffuses back to the film. Then the film, originally swollen by HO, exhibits change of coherent scattering contrast. By changing a fuel gas from H to D, SANS quantitatively detected decrease of scattering intensity at scattering maximum originating from the ion-channel in the electrolyte. After quantitative analyses on scattering intensity, which is related to water ratio (HO/DO) in the ion channel, we found that 30% of the total water is replaced by DO by changing the gas from H to D. In a stationary state of fuel cell operation using D, the scattering intensity rhythmically oscillates (respiration of fuel cell). The rhythmic oscillation found for the peak intensity is a non-equilibrium and non-linear phenomenon, in which "flooding" in a flow field is a feedback mechanism to slow down chemical reaction or water production by affecting mass transportation of air at the cathode. A valance between two diffusions, (1) back diffusion of DO from the cathode to the electrolyte and (2) diffusion of HO supplied as humidity, determines a time interval of t
Noda, Yohei; Yamaguchi, Daisuke; Hashimoto, Takeji; Shamoto, Shinichi; Koizumi, Satoshi; Yuasa, Takeshi*; Tominaga, Tetsuo*; Sone, Takuo*
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We have developed a proton spin contrast variation technique. It has been known that a good DNP performance is achieved in a polyethylene sample absorbed a vapor of TEMPO radical as an electron spin source. We recently applied this technique to silica-filled SBR rubber, which is used for tread rubber of fuel-efficient tires. Finally, we successfully evaluated silica particles' dispersion state precisely, which is supposed to have great effect on tire's fuel efficiency.
Putra, A.; Yamaguchi, Daisuke; Koizumi, Satoshi
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Kikuchi, Ryoji; Yamaguchi, Daisuke; Noda, Yohei; Koizumi, Satoshi*
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This presentation introduces latest information of ultra-small-angle polarized neutron scattering equipment (SANS-J-II) at the guide hall of Japan research reactor No.3 (JRR-3) of Japan Atomic Energy Agency. SANS-J-II is used for a static or dynamic observation of hierarchical structure from micrometer to nanometer scale in a sample. Until now, various users have visited SANS-J-II for the purpose of industrial or academic research, concerning rubber materials for tires, polymer electrolyte membrane for fuel cell, microemulsion, gel, alloy, silicon single crystal including impurity, magnetic materials and so on. As recent topics, we newly introduced a large area detector composed of 96 one-dimensional position sensitive detectors (PSD) arranged in a plane. Furthermore, in 2011, we replaced Ni-coated neutron guide tubes with 3QC supermirror-coated ones, so neutron flux is expected to increase. We are planning to verify the improved performance after the restart of JRR-3.
Yamaguchi, Daisuke; Miyamoto, Nobuyoshi*; Nakato, Teruyuki*; Koizumi, Satoshi*; Ota, Noboru*; Yagi, Naoto*; Hashimoto, Takeji; Kawakatsu, Toshihiro
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The line shape of the scattering peaks from the layered phase of colloidal plate-like particles, which consist of niobate single layer crystal (often referred as "nanosheet"), was intensively examined in this study and a distinct anisotropy was found for the power law behavior of the peak intensity with respect to the q and q directions. Namely, the power law exponent of the peak intensity for q-direction was nearly double of that for q-direction. This experimental piece of evidence was at least qualitatively in agreement with Caille s prediction. In this study, the Caille' s formula was numerically integrated and the two-dimensional calculated scattering pattern was obtained. The q-behavior of the calculated scattering pattern is naturally similar to those of theoretical analysis and obtained experimental data.
Tran, D. T.; Sawada, Shinichi; Hasegawa, Shin; Yoshimura, Kimio; Oba, Yojiro*; Onuma, Masato*; Katsumura, Yosuke*; Maekawa, Yasunari
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Fundamental understanding of the structure-property relationship of PEM is prerequisite for a material design satisfying PEM performance requirement. Therefore, the hierarchical structures of ETFE-PEMs were characterized using wide q observation in small angle X-ray scattering (SAXS) by comparing those of precursor original ETFE and polystyrene-grafted film (grafted ETFE). ETFE-PEM possesses three distinct structures: (1) Graft polymer domains with d-spacing of 390 nm, which should act as ion conducting layer; (2) Lamellar structures with d-spacing of 29 nm; (3) An inner structure of graft domains with d-spacing of 1.5 nm correspond to correlation distances of sulfonic acid group. The ion-conducting layers and lamellar structures with d-spacing of 390 nm and 29 nm in ETFE-PEM can be confirmed by atomic force microscopy (AFM) and field emission scanning electron microscopy (FE-SEM), respectively.