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Kai, Takeshi; Yokoya, Akinari; Ukai, Masatoshi*; Fujii, Kentaro; Higuchi, Mariko; Watanabe, Ritsuko
no journal, ,
no abstracts in English
-radiolysis of the mixtures of aqueous solution and zeoliteKumagai, Yuta; Kimura, Atsushi; Nagaishi, Ryuji; Taguchi, Mitsumasa; Magara, Masaaki
no journal, ,
In separation processes of radioactive nuclides from aqueous solution by adsorption on zeolite, the radioactive nuclides are concentrated in the zeolite adsorbents. Therefore understanding of the radiation influences on the mixture of zeolite and water is required for the safe operation. Since the production of hydrogen peroxide is one of the important radiation influences, the production of hydrogen peroxide in the mixture of zeolite and water was studied. The results show that the production of hydrogen peroxide was significantly suppressed in the presence of Na-Y type zeolite. Moreover, a remarkably high yield of hydrogen peroxide decomposition was observed in the mixture of aqueous hydrogen peroxide solution and the zeolite. These results suggest that hydrogen peroxide adsorbed on the zeolite was decomposed through another reaction pathway different from the radiation-induced reactions in aqueous solution.
Kimura, Atsushi; Nagasawa, Naotsugu; Taguchi, Mitsumasa
no journal, ,
no abstracts in English
Hirade, Tetsuya; Oka, Toshitaka*
no journal, ,
There are very unusual results observed by the positron annihilation lifetime measurement (PAL) in room temperature ionic liquids (IL). For example, the shortest lifetime gives twice longer lifetime than usual some other liquids. It was explained by slow positronium (Ps) formation caused by the long lived free or quasi-free electrons in IL. However, new results giving a possible explanation by Ps bubble formation was newly observed. The very unusual results observed for IL is probably caused by the slow bubble formation.
Iwamatsu, Kazuhiro; Taguchi, Mitsumasa; Sugo, Yumi; Kurashima, Satoshi; Yamashita, Shinichi; Katsumura, Yosuke
no journal, ,
no abstracts in English
C ?Sawada, Shinichi; Yamaki, Tetsuya; Asano, Masaharu; Sato, Tetsu*; Yamada, Rie*; Maekawa, Yasunari
no journal, ,
It was a big surprise to find that radiation-induced styrene-grafted films decomposed in toluene at a relatively-low temperature of 95 C. The chemiluminescence (CL) measurement was then performed in order to examine the degradation mechanism. The CL intensity of the grafted films in an oxygen atmosphere increased with time, indicating the auto-oxidation of the graft chains initiated by peroxides on the PVDF chains. This might be related to the observed degradation behavior of the grafted films.
Yamashita, Shinichi; Hiroki, Akihiro; Nagasawa, Naotsugu; Murakami, Takeshi*; Taguchi, Mitsumasa
no journal, ,
We have developed a polymer gel dosimeter by utilizing EB-crosslinked hydroxypropyl cellulose (HPC) as gel matrix and methacrylate-type monomers as radiation detector agents. Our dosimeter is less toxic than those consisting of acrylate- or acrylamide-type monomers. Another advantage of our dosimeter is high transparency of hydrogel of HPC and the fact that radiation-induced white turbidity formation in the gel matrix can easily be visually observed. White turbidity formation behaviors with irradiations were investigated for different types of radiations; 
Co -rays, 400 MeV/u C ions, and 500 MeV/u Fe ions. White turbidity could be confirmed even at 1 Gy irradiation of ion beams, however, the degrees of white turbidity were approximately half of that induced by -irradiation.
Kobayashi, Akinobu*; Hinata, Toru*; Okubo, Satoshi*; Oyama, Tomoko; Nagasawa, Naotsugu; Taguchi, Mitsumasa; Oshima, Akihiro*; Tagawa, Seiichi*; Washio, Masakazu*
no journal, ,
In this study, a Si mold used for micro/nano fabrication of polytetrafluoroethylene (PTFE) via Thermal and Radiation process for Fabricationprocess (TRaf process) was investigated with X-ray photoelectron spectroscopy. It was found that the surface of Si mold was fluorinated by TRaf process. This fluorinated Si mold was applied for nanoimprint lithography (NIL) of high adhesion material without release agent. As a result, NIL of poly(
-caprolactone) was successfully performed.
Okaya, Keiko*; Saiki, Seiichi; Seko, Noriaki; Kudo, Hisaaki*; Katsumura, Yosuke*
no journal, ,
no abstracts in English
Nuryanthi, N.*; Yamaki, Tetsuya; Koshikawa, Hiroshi; Asano, Masaharu; Sawada, Shinichi; Hasegawa, Shin; Maekawa, Yasunari; Katsumura, Yosuke*
no journal, ,
We prepared ion-track membranes of poly(vinylidene fluoride) by chemical etching in a conductometric cell and then investigated how the applied AC voltage affected etching characteristics using scanning electron microscopy. The high voltage application had some effect on the final pore diameter, which seems inconsistent with the findings of our previous conductometric analysis, while shortening the breakthrough time greatly.
Yamaki, Tetsuya
no journal, ,
Since 2002, we have been intensively developing highly-durable polymer electrolyte membranes for fuel cell applications by a radiation-induced graft polymerization method. My talk deals with the very beginning of this project, the following developments based on quantum-beam technologies, 
, radiation crosslinking, nano-structure control, etc. and new strategies toward the future.