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and Ag/TiO under electron beam irradiationHakoda, Teruyuki; Matsumoto, Kanae; Mizuno, Akira*; Hirota, Koichi
no journal, ,
no abstracts in English
Taguchi, Mitsumasa; Baldacchino, G.*; Kurashima, Satoshi; Kimura, Atsushi; Katsumura, Yosuke*; Hirota, Koichi
no journal, ,
no abstracts in English
Kumada, Takayuki; Noda, Yohei; Hashimoto, Takeji; Koizumi, Satoshi
no journal, ,
We try to determine structure of spa produced by radiolysis of cryocrystals using small-angle neutron scattering (SANS) and dynamic nuclear polarization (DNP) system. In this presentation, we will talk about the principle of SANS and DNP system, idea to measure spa, and present status.
Asano, Masaharu; Yamaki, Tetsuya; Maekawa, Yasunari; Yoshida, Masaru; Kanega, Jun*; Enokida, Takashi*
no journal, ,
The newly developed amorphous PFA was irradiated with 
-rays under different conditions. It was found that the radiation crosslinking occurred even at temperatures ranging from 0 to 60
C, thereby significantly enhancing the mechanical properties. This can be attributed to high molecular mobility due to the glass translation temperature of the PFA as low as 12 to 42C.
Nakagawa, Seiko*; Ota, Nobuaki*; Hirota, Koichi; Taguchi, Mitsumasa
no journal, ,
no abstracts in English
or P doped polyanilineOta, Nobuaki*; Nakagawa, Seiko*; Nishiyama, Fumitaka*; Morishita, Norio; Oshima, Takeshi
no journal, ,
A bulk with 0.5-1 mm thickness of polyaniline was irradiated by the 3MV Tandem accelerator at the Takasaki Ion Accelerators for Advanced Radiation Application (TIARA) facility. ESR spectra of N or P doped polyaniline were measured at 77 K. A broad peak of polyaniline radical was observed. Except for polyaniline radical, new signals were also appeared when the fluence of doped N was less than 2
10
ions/cm
and that of P was more than 610ions/cm.
Kumagai, Yuta; Nagaishi, Ryuji; Yamada, Reiji
no journal, ,
The coexistence effect of colloidal silica on the radiation induced reduction of Cr
O
in acidic aqueous solutions was investigated by -radiolysis experiments to seek a basic understanding of the coexistence effect of oxides. The reduction yield of CrO increased with the amount of silica up to around 10wt% and then seemed to reach a limit. Then a relation between the reduction yield and reactions of OH radical in the presence of sillica was studied. In the solutions containing 
-butanol to scavenge OH radical the yield was as high as the upper limit even in the absence of silica and no further increase was observed by the addition of silica. This result was discussed based on the yields of the products of water radiolysis, which suggests that coexisting silica has an effect on the reactions of OH radical and that the increase in the reduction of CrO are resulted from interaction between silica and OH radical.
Seko, Noriaki; Fatmuanis, B.*; Tamada, Masao
no journal, ,
Scandium (Sc) has been selective recovered from aqueous solution by using fibrous adsorbent which was directly synthesized with graft polymerization method of phosphoric acid monomer onto nonwoven fabrics made of polyethylene-coated polypropylene fiber. Behavior of the resulting adsorbent in uptake of Sc was evaluated by both batch and columnar methods. In the column test, the breakthrough of Sc was evaluated with different flow rates in space velocity by pumping 1 to 5 ppm Sc solution into the column at pH 1 to 3. Breakthrough points of 1 or 5 ppm were 750 and 250 bed volumes (BV), respectively. The adsorbed Sc on adsorbent was able to be desorbed quantitatively. The adsorbent had excellent ability without any significant loss of absorption capacity after 10 time's cyclic usage.
particlesNagaishi, Ryuji; Kumagai, Yuta; Yamada, Reiji
no journal, ,
Radiation- and photo-induced reduction of Ce(IV) ion was studied in aqueous acid solutions containing TiO particles. The reduced amount of Ce(IV) originated from the particles in the radiolysis was independent of the addition of formic acid, while the amount in the photolysis in the presence of formic acid was twice as much as that in the absence. When the particles supported by platinum elements, the amount in the radiolysis became larger than that for the original particles. The reduction process of Ce(IV) originated from the ionization and excitation of TiO in the radiolysis was discussed by comparing the radiation- and photo-induced one.
Hirade, Tetsuya
no journal, ,
Ionic liquids are safe and environment friendly materials. It is expected to use for the processing of spent nuclear fuel. Radiation chemistry of ionic liquids is important for the use in radiation-filled environment. Positron annihilation lifetime and positron age-momentum correlation measurements were performed to understand pico-second reactions in the spur. Solvation of dry electrons takes probably about 30ps. Positronium formation also takes about 70ps. Reactions in ionic liquids are slower than in molecular liquids and then ionic liquids can provide interesting and new researches.
Lin, M.; Kumagai, Yuta; Muroya, Yusa*; Katsumura, Yosuke; Lampre, I.*; Coudert, F.*; Boutin, A.*; Mostafavi, M.*
no journal, ,
In this work, we measure the absorption spectra of hydrated electron in DO solutions containing different concentrations of Li
and Mg
cations at various temperatures by pulse radiolysis techniques, and perform quantum classical molecular dynamics (QCMD) simulations to explain the shift of the absorption spectra due to the combined effects of temperature and salt concentration.
Fujii, Kentaro; Yokoya, Akinari; Shikazono, Naoya
no journal, ,
To investigate the K-shell photoabsorption effect on DNA damage, dry plasmid DNA (pUC18) films were irradiated with monochromatic soft X-rays. Four photon energies, 270, 380, 435, and 560eV, were chosen for the irradiation experiments. Plasmid DNA film irradiated in vacuum was analyzed by agarose gel electrophoresis to examine the conformational changes caused by strand breaks. The yields of base lesions were also determined by the post-irradiation-treatment of the DNA with enzymatic probes (Fpg and Endo III) which excise base lesions and visualize them as strand breaks. The strand break yield at 560eV was 2 times larger than those at other energies. This result suggests that oxygen photoionization may efficiently cause DNA damages through specific radical processes or degradation at sugar moiety.
Mizote, Norihito*; Katakai, Akio; Tamada, Masao; Matsuoka, Hiroshige*
no journal, ,
no abstracts in English
Hata, Kuniki; Katsumura, Yosuke; Lin, M.; Muroya, Yusa*; Fu, H.*; Kudo, Hisaaki*; Nakagawa, Keiichi*; Nakagawa, Hidehiko*
no journal, ,
The reactivity of edaravone with some oxidative radicals (
OH, N
, Br
, SO
, CClOO) has been measured by pulse radiolysis. The reaction product of edaravone with OH was different from those with other radicals. The rate constants of edaravone derivatives with OH have also been determined by both direct measurement and a competition method using CO and DMPO as competitors.
Yamashita, Shinichi*; Katsumura, Yosuke; Lin, M.; Muroya, Yusa*; Murakami, Takeshi*; Meesungnoen, J.*; Jay-Gerin, J.-P.*
no journal, ,
Simulation based on diffusion kinetic model has been carried out to investigate on "initial" track structure at 10
s formed by heavy-ion irradiation and to compare with reported values such as primary yields in pure water and 
(Fe
) in the Fricke solution. Several dose distributions proposed in literatures were taken into the simulation. Spatial distributions of "initial" products at 10 s calculated with Monte-Carlo simulation were compared with the dose distributions reported in the literature.
Fu, H.*; Katsumura, Yosuke; Lin, M.; Muroya, Yusa*; Hata, Kuniki
no journal, ,
The transient spectral properties and rate constants of the free radical scavenger silybin reacting with various one-electron oxidants such as OH, Br, N, NO, CO, and CClO were studied by pulse radiolysis techniques. Repair activities of dGMP-OH or tryptophan radicals by silybin at neutral pH were also reported.
Takahashi, Hiroyuki*; Katsumura, Yosuke; Lin, M.; Muroya, Yusa*; Kumagai, Yuta; Kudo, Hisaaki*
no journal, ,
We have investigated radiation chemical reactions in benzoate aqueous aolution by pulse radiolysis. The transient absorption spectra, the rate constant for the reaction of benzoate ion with the hydroxyl radical, and the acid dissociation constant of the hydroxyl radical have been determined. In addition, temperature dependent pK
(OH/O) value has also been evaluated.
Saiki, Seiichi; Muroya, Yusa*; Nagasawa, Naotsugu; Tamada, Masao; Kudo, Hisaaki*; Katsumura, Yosuke*
no journal, ,
Carboxymethyl cellulose (CMC) forms gel at high concentrated solution by irradiation. It seems that polymer radicals, which produced by reactions between OH of water radiolysis products, reacts with each other to form crosslink point. To explain the mechanism of the crosslinking reaction, we investigated the behavior and the position of polymer radicals in irradiated CMC aqueous solution. In the UV absorption spectral measurement after pulse electron beam irradiation, we observed the slow decay of absorbance for about 30 minutes at 10 mM CMC concentration, and confirmed that the initial absorbance was higher with increasing dose. The decay was slower with more concentrated solution and higher molecular weight. Therefore, it seems that the initial yield of polymer radicals is affected by dose and reaction rate is by viscosity of solution. In the ESR measurement after the reaction with OH formed by photolysis of HO, we could estimate the position of CMC radical produced by OH which radical is located on secondary carbon of carboxymethyl substituent on C
.
Hoshina, Hiroyuki; Seko, Noriaki; Kasai, Noboru; Okada, Kenji; Ueki, Yuji; Tamada, Masao; Iyatomi, Yosuke; Ogata, Nobuhisa
no journal, ,
no abstracts in English
Sekiguchi, Tetsuhiro; Baba, Yuji; Shimoyama, Iwao
no journal, ,
Using a newly developed rotatable time-of-flight mass spectrometer (R-TOF-MS) and polarized synchrotron radiation, fragmentation and desorption pathways occurring at the top layers of molecular solids have been investigated. We estimate ratio between direct and indirect mechanisms on the basis of polarization-angle dependencies of TOF mass spectra, high-resolution electron- and ion-NEXAFS in condensed chlorobenzene (C6D5Cl).