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Tsukahara, Takehiko*; Saga, Kaname*; Suzuki, Hideya*; Matsumura, Tatsuro
Kurin Tekunoroji, 29(12), p.4 - 7, 2019/12
no abstracts in English
Saga, Kaname*; Suzuki, Hideya; Matsumura, Tatsuro; Tsukahara, Takehiko*
Analytical Sciences, 35(4), p.461 - 464, 2019/04
Times Cited Count:3 Percentile:12.00(Chemistry, Analytical)The phase transition-based gelification phenomenon of poly--isopropylacrylamide (PNIPAAm) in aqueous solutions has a great potential in developing new waste-free extraction processes of metal ions. By using hydrophobic diglycolamide-typed ligands in gelification extraction, a one-step complete extraction of all the RE ions from a nitric acid solution was successfully realized.
Shimoyama, Iwao; Baba, Yuji; Hirao, Norie*
Applied Surface Science, 405, p.255 - 266, 2017/05
Times Cited Count:1 Percentile:5.82(Chemistry, Physical)NEXAFS spectroscopy is applied to study orientation structures of polydimethylsilane (PDMS) films deposited on heteroatom-doped graphite substrates prepared by ion beam doping. The Si -edge NEXAFS spectra of PDMS show opposite trends of polarization dependence for non irradiated and N-irradiated substrates, and show no polarization dependence for an Ar-irradiated substrate. Based on a theoretical interpretation of the NEXAFS spectra via first-principles calculations, we clarify that PDMS films have lying, standing, and random orientations on the non irradiated, N-irradiated, and Ar-irradiated substrates, respectively. Furthermore, photoemission electron microscopy indicates that the orientation of a PDMS film can be controlled with microstructures on the order of m by separating irradiated and non irradiated areas on the graphite surface. These results suggest that surface modification of graphite using ion beam doping is useful for micro-orientation control of organic thin films.
Meguro, Yoshihiro; Sato, Junya
Dekomisshoningu Giho, (54), p.48 - 55, 2016/09
Various radioactive wastes, especially liquiform, pulverized or grained one, have to be immobilized in a disposal container, and methods such as cement solidification, bituminization, etc are so far examined and have been adopted. In recent years novel inorganic solidification materials have been developed. These are named Alkali-activated materials and so geopolymer. Mainly studies of geopolymer applying to radioactive wastes as a solidification material are under research and development stage, but the cases applied to solidification of the real radioactive waste increase a lot. In this report, we briefly explain about some research studies and practical examples of the geopolymer in the field of nuclear energy, particularly those of radioactive wastes generated in Fukushima Daiichi Nuclear Power Station.
Motokawa, Ryuhei; Taniguchi, Tatsuo*; Kumada, Takayuki; Iida, You*; Aoyagi, Shota*; Sasaki, Yusuke*; Kori, Michinari*; Kishikawa, Keiki*
Macromolecules, 49(16), p.6041 - 6049, 2016/08
Times Cited Count:20 Percentile:59.85(Polymer Science)Li, Z.*; Onuki, Toshihiko; Ikeda, Ko*
Materials, 9(8), p.633_1 - 633_17, 2016/08
Times Cited Count:28 Percentile:77.56(Chemistry, Physical)Geopolymer samples were prepared at room temperature using paper sludge ashes and immobilization of Sr and Cs in these samples were evaluated by short-term leaching test. The prepared geopolymer samples were semi-crystalline and porous. For the leaching test, the geopolymer samples containing 1 weight % of strontium nitrate or cesium nitrate were prepared, crushed to be finer than 4 mm in size, and immersed in a phthalic salt buffer (pH4) for 6 h. About 0.2% of Sr and 1.3% of Cs were leached from the geopolymer samples.
Hiroki, Akihiro; Yamashita, Shinichi*; Kimura, Atsushi; Nagasawa, Naotsugu; Taguchi, Mitsumasa
Nuclear Instruments and Methods in Physics Research B, 365(Part B), p.583 - 586, 2015/12
Effects of liner energy transfer (LET) and dose rate on the optical property of polymer gel dosimeters were investigated. The dosimeter prepared by using a radiation-crosslinked hydroxypropyl cellulose gel and methacrylate monomers such as 2-hydroxyethyl methacrylate and nonaethylene glycol dimethacrylate showed the color change from colorless to white with the He, C, Fe ions irradiation. Absorbance of the irradiated dosimeters increased with the dose up to 10 Gy. The absorbance of the dosimeters at the same total dose decreased with increasing dose rate in the range of 0.1 to 6.8 Gy/min. The absorbance decreased in order of He, C, Fe ions, which was in agreement with a change of LET. The increase in LET affected the decrease in the number of polymerization initiator such as OH radical and hydrated electron, resulting in the reduction of the absorbance of the dosimeters.
Hiroki, Akihiro; Yamashita, Shinichi*; Taguchi, Mitsumasa
Journal of Physics; Conference Series, 573(1), p.012028_1 - 012028_4, 2015/01
Times Cited Count:4 Percentile:78.90(Engineering, Biomedical)Polymer gel dosimeters based on radiation-crosslinked hydroxypropyl cellulose gel were prepared, which comprised 2-hydroxyethyl methacrylate (HEMA) and polyethylene glycol dimethacrylate (9G) as less toxic monomers and tetrakis (hydroxymethyl) phosphoniumu chloride (THPC) as an antioxidant. The dosimeters exposed to Co -rays became cloudy at only 1 Gy. The irradiated dosimeters were optically analyzed by using a UV-vis spectrophotometer to evaluate dose response. Absorbance of the dosimeters linearly increased in the dose range from 0 to 10 Gy. The dose sensitivity increased with increasing 9G concentration. The dosimeter with 2 wt% HEMA, 3 wt% 9G, and 0.16 wt% THPC exhibited about 0.04 Abs Gy of the dose sensitivity. The dose sensitivity of the dosimeters was also enhanced by increment in THPC, reached about 0.06 Abs Gy at 0.40 wt% THPC.
Katakai, Akio; Tamada, Masao; Nagamoto, Hiroyuki*; Miyagawa, Hiroshi*
Nihon Ion Kokan Gakkai-Shi, 16(2), p.122 - 126, 2005/05
A chelating fiber containing an amidoxime group as a chelate-forming group was prepared by radiation-induced cograft polymerization of acrylonitrile and methacrylic acid and subsequent conversion of the produced cyano group into the amidoxime group. The effect of repeated use of monomers for radiation-induced graft copolymerization on the composition of the graft chain and its adsorption capacity for metal ions was determined. The degree of cografting decreased by as low as 10% at the fourth cycle of cografting, compared with an initial degree of cografting of 170%, because the amount of homopolymer formed in cografting was negligibly small at 0.15 g/L of the monomer solution. The repeated use of monomers did not affect the amidoxime group density and the adsorption capacities of zinc and cadmium ions, resulting in the cost reduction of the preparation of the chelating fiber.
Sakai, Seiji; Naramoto, Hiroshi*; Lavrentiev, V.*; Narumi, Kazumasa; Maekawa, Masaki; Kawasuso, Atsuo; Yaita, Tsuyoshi; Baba, Yuji
Materials Transactions, 46(4), p.765 - 768, 2005/04
Times Cited Count:17 Percentile:70.72(Materials Science, Multidisciplinary)A systematic study of the atom-level mixtures between Co and C has made possible to find a new C-based compound phase, CoC (x5). It is confirmed with the EXAFS analysis and the positron annihilation study that the polymeric structure is developed three-dimensionally by bridging two C molecules with the covalently bonded Co atom.
Motokawa, Ryuhei; Annaka, Masahiko*; Nakahira, Takayuki*; Koizumi, Satoshi
Colloids and Surfaces B; Biointerfaces, 38(3-4), p.213 - 219, 2004/11
no abstracts in English
Tamada, Masao; Seko, Noriaki; Yoshii, Fumio
Radiation Physics and Chemistry, 71(1-2), p.223 - 227, 2004/09
Times Cited Count:71 Percentile:96.43(Chemistry, Physical)Graft polymerization and crosslinking in radiation processing were attractive techniques to modify conventional polymers. In the case of graftpolymerization, metal adsorbent was prepared by introducing the chelate function to trunk polymer like polyethylene. The obtained metal adsorbent was applied to the recovery of uranium in seawater. Three years' marine experiment revealed that 1kg of uranium could be collected by using graft-adsorbent. Natural polymers such as derivatives of starch and cellulose led irradiation crosslinking at paste-like condition and formed hydrogels. These hydrogels had degradability even after crosslinking. The mat of degradable hydrogel was effective to prevent bedsores as a healthcare product. After use, the hydrogel can be converted to fertilizer by decompositions.
Kamaya, Eiki*; Matsumoto, Fukashi*; Kondo, Yasuhiro*; Chujo, Yoshiki*; Katagiri, Masaki
Nuclear Instruments and Methods in Physics Research A, 529(1-3), p.329 - 331, 2004/08
Times Cited Count:12 Percentile:61.35(Instruments & Instrumentation)no abstracts in English
Tamada, Masao
Kankyo Shigen Kogaku, 51(2), p.99 - 101, 2004/04
Fibrous chelate adsorbents have been synthesized by radiation-induced graft polymerization onto polyethylene nonwoven fabric. Graft polymerization was induced by electron beam irradiation to the trunk polymer. Then, irradiated trunk polymer was contacted with reactive monomer having function of chelate agent or its precursor. The precursor was chemically converted to chelate agent. The resulting fibrous chelate adsorbent gave the high space velocity more than 500 h in removal of lead from its solution. Such adsorbent was applied to the removal of cadmium from scallop processing waste and the removal of lead from the contaminated water which was produced by washing the inside of incinerator.
Yoshii, Fumio
Kobunshi Geru No Saishin Doko, p.150 - 163, 2004/00
no abstracts in English
Tamada, Masao
Oyo Butsuri, 72(4), p.453 - 456, 2003/04
Radiation induced graft-polymerization is sophisticated technique which is capable of introducing aiming functions into conventional polymers. Especially, pre-irradiation method is available for industrialization owing to discrete processes of irradiation and grafting. The chelate adsorbents having high selectivity against metals were synthesized by the graft-polymerization. The recovery of uranium from seawater and the removal of toxic metals from wastewater were described as applicable examples of the graft adsorbents.
Narumi, Kazumasa; Xu, Y.; Miyashita, Kiyoshi*; Naramoto, Hiroshi
JAERI-Review 2002-035, TIARA Annual Report 2001, p.176 - 178, 2002/11
no abstracts in English
Narumi, Kazumasa; Naramoto, Hiroshi
Surface & Coatings Technology, 158-159, p.364 - 367, 2002/09
Irradiation effect of 7 MeV C ions on C thin films on Si(111) substrates were investigated. Raman scattering spectroscopy showed that C film had been already polymerized and that depolymerization of the polymerized C films progressed up to the dose of 1.110/cm. After the depolymerization, the C films were transformed into a form of amorphous carbon at higher dose. The AFM analysis of conductivity of the film shows the results consistent with the Raman-scattering-spectroscopy analysis of the film.
Goto, Masahiro*; Zhigilei, L. V.*; Hobley, J.*; Kishimoto, Maki; Garrison, B. J.*; Fukumura, H.*
Journal of Applied Physics, 90(9), p.4755 - 4760, 2001/11
Times Cited Count:17 Percentile:58.42(Physics, Applied)no abstracts in English
Chen, J.; Maekawa, Yasunari; Yoshida, Masaru; Tsubokawa, Norio*
Journal of Polymer Science, Part B; Polymer Physics, 40, p.134 - 141, 2001/11
Times Cited Count:7 Percentile:27.44(Polymer Science)no abstracts in English