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C; Absorption spectra, kinetics and yield of carboxyl radical CO
Lin, M.; Katsumura, Yosuke; Muroya, Yusa*; He, H.*; Miyazaki, Toyoaki*; Hiroishi, Daisuke*
Radiation Physics and Chemistry, 77(10-12), p.1208 - 1212, 2008/10
Times Cited Count：24 Percentile：81.47(Chemistry, Physical)Sodium formate neutral aqueous solutions saturated with N
O were studied by pulse radiolysis techniques from room temperature to 400 C. The absorption spectra of CO show a red shift from 
= 235 nm at 25 C to 280 nm at 400 C. The second-order decay of CO is not monotonically temperature-dependent: the rate constant (2
/
) slightly increases with temperature up to 200 C, then decreases to a valley at 300 C, and it sharply increases again for temperature 
350 C. 
(CO) increases with temperature from room temperature to 400 C. Significant density effect on (CO) is found at 400 C. Assumed (CO) is independent on temperature, at 400 C, the density dependence of (CO) in the presence of NO agrees well with that of [(e
)+(H
)+(OH)].
(MV
) in deaerated methyl viologen solutions containing various concentrations of sodium formate and Monte Carlo simulationYamashita, Shinichi; Katsumura, Yosuke; Lin, M.; Muroya, Yusa*; Miyazaki, Toyoaki*; Murakami, Takeshi*; Meesungnoen, J.*; Jay-Gerin, J.-P.*
Radiation Research, 170(4), p.521 - 533, 2008/10
Times Cited Count：7 Percentile：27.16(Biology)Formation yields of methyl viologen cation radicals (MV) (100 eV)
have been measured in deaerated aqueous solutions of methyl viologen, MV
, containing various concentrations of formate anion after irradiation with six different ion beams (from 
He to 
Fe
with incident energies varying from 0.6 to 28 GeV) provided by HIMAC at NIRS in Japan. In parallel to the above measurements, Monte Carlo simulations of the radiolysis of the MV-formate solutions have been performed to investigate complementarily mechanism from which distinctive irradiation effects of heavy ions are derived from the microscopic viewpoints experimentally non-feasible.
values as track segment yieldsYamashita, Shinichi; Katsumura, Yosuke; Lin, M.; Muroya, Yusa*; Miyazaki, Toyoaki*; Murakami, Takeshi*
Radiation Physics and Chemistry, 77(4), p.439 - 446, 2008/04
Times Cited Count：34 Percentile：88.66(Chemistry, Physical)Water radiolysis has been investigated with heavy ions having energies up to 28 GeV provided from the Heavy Ion Medical Accelerator in Chiba (HIMAC) at the National Institute of Radiological Sciences (NIRS). Beams of He, 
C
, 
Ne
, 
Si
, 
Ar
and Fe with respective energies of 150, 400, 400, 490, 500 and 500 MeV per u corresponding LET values of 2.2, 13, 30, 54, 92 and 183 eV per nm, respectively, were taken for the irradiation. The LET changes in sample solutions can be neglected due to their high energies for the irradiation of 1-cm cells. Primary values have been determined for three important products, hydrated electron (e
), hydroxyl radical (OH), and hydrogen peroxide (HO) as track segment yields (differential yields) under the conditions of neutral pH.
-trifluoromethyl-
, -difluorovinyl) terephthalate with excess of various ethersEnomoto, Kazuyuki*; Maekawa, Yasunari; Katsumura, Yosuke*; Miyazaki, Toyoaki*; Yoshida, Masaru; Hamana, Hiroshi*; Narita, Tadashi*
Macromolecules, 38(23), p.9584 - 9593, 2005/11
Times Cited Count：9 Percentile：30.73(Polymer Science)Radiation-induced radical polyaddition of bis(-trifluoromethyl-,-difluorovinyl) terephthalate [CF=C(CF3)OCOC
H
COOC(CF
)=CF] (BFP) in the presence of an excess of cyclic and acyclic ethers in feed was examined at 0C using 
-rays irradiation. Irradiation of BFP with an 8-fold excess of 1,4-dioxane (DOX) and diethyl ether (EE) gave monomodal polymers consisting of the 
ernating unit of BFP and DOX moieties (poly(BFP--DOX), 
= 5.110
) and of BFP and EE (poly(BFP--EE), =3.910), respectively. The irradiation of BFP with an 8-fold excess of tetrahydrofuran or tetrahydropyran provided only 1:2 addition products in high yields. Mono-functional 2-benzoxypentafluoropropene [CF=C(CF)OCOCH
] (BPFP) as a model compound showed preferential formation of the 2:1 adduct to the 1:1 adduct with DOX and EE. The kinetic analysis of the model reactions revealed that the rate constants for the formation of the 2:1 adducts (
) of BPFP with DOX and EE were two orders of magnitude higher than those of the 1:1 adducts (
). Poly(BFP--DOX) showed higher radiation resistance than poly(BFP--EE) in solid states as well as in solution. It was concluded that radiation-induced step-growth polymerization under the stoichiometric imbalance of the two compounds requires a high / value as well as high radiation resistance for the formation of high molecular weight polymers.
Miyazaki, Toyoaki*; Katsumura, Yosuke*; Lin, M.*; Muroya, Yusa*; Taguchi, Mitsumasa; Asano, Masaharu; Yoshida, Masaru
no journal, ,
To clarify radiation-induced decomposition of benzene in high-temperature and supercritical water, -radiolysis study at elevated temperature has been performed. Products obtained are phenol, biphenyl and isomers of dihydroxycyclohexadienls. In addition to phenol and biphenyl, carbon dioxide, carbon monoxide and hydrogen are obtained as major products at supercritical condition. This result indicates that mechanism of benzene decomposition is changed by elevating temperature.
Yamashita, Shinichi*; Katsumura, Yosuke; Lin, M.; Muroya, Yusa*; Miyazaki, Toyoaki*; Murakami, Takeshi*; Meesungnoen, J.*; Jay-Gerin, J.-P.*
no journal, ,
no abstracts in English
Maeyama, Takuya*; Katsumura, Yosuke; Yamashita, Shinichi*; Lin, M.; Muroya, Yusa*; Miyazaki, Toyoaki*; Murakami, Takeshi*; Baldacchino, G.*
no journal, ,
no abstracts in English
Yamashita, Shinichi*; Katsumura, Yosuke; Lin, M.; Muroya, Yusa*; Miyazaki, Toyoaki*; Murakami, Takeshi*; Meesungnoen, J.*; Jay-Gerin, J.-P.*
no journal, ,
