• 제목/요약/키워드: Radiation technology

검색결과 4,750건 처리시간 0.034초

The Radiation Resistance Evaluation of Electrically Insulating Polymers

  • Lee, Dong-Hoon;Jung, Chan-Hee;Hwang, In-Tae;Choi, Jae-Hak;Im, Don-Sun;Kim, Ki-Yup;Nho, Young-Chang
    • 방사선산업학회지
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    • 제5권3호
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    • pp.237-242
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    • 2011
  • In this research, the radiation resistance of ethylene propylene rubber (EPR) and chlorosulfonated polyethylene (CSPE) which can be used as a insulating materials of for electrical cable in the nuclear power plant were investigated. EPR and CSPE were irradiated by ${\gamma}$-ray at various doses ranging from 50 to 500 kGy at room temperature in air. The irradiated EPR and CSPE was investigated in terms of activation energy, mechanical properties, and oxidation stability. The experimental results revealed that CSPE exhibited the higher radiation resistance in comparison to that of EPR.

Effects of ${\gamma}$-Irradiation on Immunological Activities of ${\beta}$-Glucan

  • Kim, Jae-Hun;Sung, Nak-Yun;Byun, Eui-Hong;Kwon, Sun-Kyu;Song, Beom-Seok;Choi, Jong-Il;Yoon, Yohan;Kim, Jin-Kyu;Byun, Myung-Woo;Lee, Ju-Woon
    • Food Science and Biotechnology
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    • 제18권5호
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    • pp.1305-1309
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    • 2009
  • This study evaluated the effects of $\gamma$-irradiation on immunomodulating properties and structural changes of ${\beta}$-glucan. ${\beta}$-Glucan solutions (10 mg/mL) were ${\gamma}$-irradiated at 10, 30, and 50 kGy. Splenocyte proliferation and cytokine (interferon-${\gamma}$ and interlukin-2) productions by ${\gamma}$-irradiated ${\beta}$-glucan were evaluated in in vivo and in vitro, and structural changes of ${\beta}$-glucan were also determined after ${\gamma}$-irradiation. ${\gamma}$-Irradiation on ${\beta}$-glucan at 50 kGy enhanced splenocyte proliferation and cytokine productions, (p<0.05) and cleft glycosidic bonds of ${\beta}$-glucan resulting in lower the molecular weight. These results indicate that the use of ${\gamma}$-irradiation on ${\beta}$-glucan may be useful for improving its immunological activity by lowering the molecular weight of ${\beta}$-glucan.

Influence of Gamma Irradiation on Greening of Mung Bean Seedlings

  • Kim, Jin-Hong;Moon, Yu-Ran;Kim, Jae-Sung;Lee, Min-Hee;Lee, Seung-Sik;Chung, Byung-Yeoup
    • 환경생물
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    • 제26권1호
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    • pp.15-21
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    • 2008
  • Ionizing radiation causes many alterations in photosynthetic machineries. However, there is no information about effects of ionizing radiation on the development of photosynthetic machineries in plants. We investigated the greening of etiolated mung bean seedlings after gamma-irradiation of 50 to 300 Gy. The irradiation inhibited seedling growth with great dependence on the radiation dose. In particular, growth of stems was more affected than that of hypocotyls. Irradiated leaves showed inhibition in growth, aberration in morphology, and yellowing in color depending on the radiation dose. Contents of photosynthetic pigments such as chlorophylls and carotenoids were significantly decreased in the irradiated leaves. The apparent electron transport rate for photosynthesis, ETR, was similarly changed depending on the radiation dose. However, the maximal photochemical efficiency of Photosystem II (PSII), Fv/Fm, was little affected by the irradiation. Moreover, the 50-Gy seedlings maintained the control level of light saturating for photosynthesis and showed slightly higher Fv/Fm values in spite of significant decreases in the photosynthetic pigment content and ETR. These results suggest that the inhibition of the overall photosynthetic capacity couldn’t be causally relatqaed with the repression in the initial development of irradiated seedlings and that the overall photosynthetic machineries can develop and work to some extent as a concerted system for photosynthesis even after exposure to acute doses of ionizing radiation.

MEVVA ion Source And Filtered Thin-Film Deposition System

  • Liu, A.D.;Zhang, H.X.;Zhang, T.H.;Zhang, X.Y.;Wu, X.Y.;Zhang, S.J.;Li, Q.
    • Journal of Korean Vacuum Science & Technology
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    • 제6권2호
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    • pp.55-57
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    • 2002
  • Metal-vapor-vacuum-arc ion source is an ideal source for both high current metal ion implanter and high current plasma thin-film deposition systems. It uses the direct evaporation of metal from surface of cathode by vacuum arc to produce a very high flux of ion plasmas. The MEVVA ion source, the high-current metal-ion implanter and high-current magnetic-field-filtered plasma thin-film deposition systems developed in Beijing Normal University are introduced in this paper.

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방사선을 이용한 연료전지막 국내 제조 기술 개발 현황 (Current R&D Status of Fuel Cell Membranes by Radiation in Korea)

  • 신준화;손준용;노영창;강태진;김동수;임돈순;이병헌;김재호
    • 방사선산업학회지
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    • 제6권4호
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    • pp.289-297
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    • 2012
  • Since Nafion is very expensive and shows the decreased fuel cell performance over $80^{\circ}C$ operating temperature, much work has been carried out in the search for cheaper membrane with high fuel cell performance. Radiation is known to be very useful for the preparation of the polymer electrolyte membranes since it can be effectively used for the introduction of ion conducting functional groups into the commercial film with high mechanical and chemical properties. Here, we summarize the our recent progress in the development of fuel cell membranes by utilizing radiation.