• 제목/요약/키워드: Pre-irradiation

검색결과 195건 처리시간 0.024초

Removal of Organic Matter and Nutrient in Swine Wastewater Using a Membrane System

  • Lim, Seung Joo;Kim, Sun Kyong;Lee, Yong-gu;Kim, Tak-Hyun
    • 방사선산업학회지
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    • 제6권1호
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    • pp.75-82
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    • 2012
  • Swine wastewater was treated using a unique sequence of ion exchange membrane bed system (IEBR). Organic matter and nutrient in swine wastewater was pre-treated by electron beam irradiation. The optimal dose for solubilization of organic matter in swine wastewater ranged from 20 kGy to 75 kGy. The carbohydrates, proteins, and lipids were investigated as the solubilized organic fraction of swine wastewater and proteins and lipids mainly contained of the solubilized organic matter. The solubilization of organic matter in swine wastewater was affected by the combination effect of temperature and a dose. The average chemical oxygen demand (COD) removal efficiency under room temperature conditions was 67.1%, while that under psychrophilic conditions was 54.6%. For removal of ammonia, the removal efficiency decreased from 63.6% at $23^{\circ}C$ to 33.5% $16.8^{\circ}C$. On the other hand, the removal of phosphorus was not a function of temperature. Struvite was one of main mechanisms in anaerobic condition.

소아백혈병 환자의 전신방사선조사 시 조직보상체의 재질변화에 따른 선량평가 (In Pediatric Leukemia, Dose Evaluation according to the Type of Compensators in Total Body Irradiation)

  • 이동연;김창수;김정훈
    • 대한방사선기술학회지:방사선기술과학
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    • 제38권1호
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    • pp.17-21
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    • 2015
  • 소아백혈병의 치료방법 인 조혈모세포이식법의 전처치 방법으로서 항암제와 함께 대표적으로 사용되고 있는 전신방사선조사에 대하여 치료를 시행하기 전 정량적인 인체장기에 대한 선량을 평가하고자 하였다. 모의실험 프로그램 MCNPX를 사용하여 가상의 공간에서 소아용 모의피폭체를 대상으로 조직보상체의 재질을 변화시켜 실험을 진행하였다. 그 결과 첫째, 평균피부선량은 조직보상체의 재질에 따라 Plexiglass는 74.60 mGy/min, Al은 73.96 mGy/min, Cu는 72.26 mGy/min, Pb의 경우 67.90 mGy/min을 보였다. 둘째, 심부선량은 조직보상체 재질에 상관없이 갑상선, 생식선, 소화기계, 머리, 폐, 신장의 순으로 높게 나타났다. 끝으로 조직보상체와 환자와의 거리는 50 cm 이격시켰을 때가 이상적인 것으로 분석되었다. 본 연구결과를 토대로 할 때, 조직보상체 Al, Cu, Pb은 현재 사용되고 있는 Plexiglass 재질을 대체할 수 있을 것으로 판단된다.

저선량 ${\gamma}$선 조사가 대두 식물체의 방사선 감수성에 미치는 영향 (Effects of Low Dose ${\gamma}$ Radiation on the Radiosensitivity of Soybean(Glycine max L.) Plant)

  • 김재성;채성기;백명화;김동희
    • 한국환경농학회지
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    • 제19권4호
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    • pp.324-327
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    • 2000
  • 저선량 조사한 대두종자의 초기생육과 대두 유식물체의 후속고선량에 대한 방사선 감수성 변화를 알아보고자 저선량 0, 4, 8, 12, 20 Gy를 조사하여 재배한 대두 유식물체에 ${\gamma}$선 50, 100, 200 Gy를 조사한 후 생육상황을 관찰하였다. 저선량 조사에 의해 대두 신규종자의 발아율 증가효과는 없었으나 작물 생장 증대효과는 있었으며 저선량 8 Gy 조사구가 가장 효과적이었다. 대두유식물체의 고선량 방사선에 의한 생육장해는 사전 저선량조사에 의해 크게 감소되었으며 저선량 조사에 의한 고선량 방사선 저항성 증가는 8 Gy와 20 Gy조사에서 가장 효과적이었다.

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동충하초 추출물이 감마선에 조사된 생쥐에 미치는 방사선방호효과 (Radioprotective Effects of Cordyceps sinensis Extracts on ${\gamma}-Irradiated$ Mice)

  • 유병규;김온중;김재영
    • 대한방사선기술학회지:방사선기술과학
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    • 제22권1호
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    • pp.67-71
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    • 1999
  • 전신 ${\gamma}$ - 선 조사 24 시간 전에 Cordyceps sinensis (Cs) 추출물을 복강에 단일 투여하였을 때 ${\gamma}$ - 선 조사된 생쥐의 생존율, 체중, 기관 무게 및 혈청 대사물에 미치는 효과를 조사하였다. Cs 추출물의 투여는 ${\gamma}$ - 선을 조사한 생쥐의 40 - day 생존율을 66.7%에서 83.4%로 증가시켰다. 또한 Cs 추출물의 투여는 ${\gamma}$ - 선 조사에 의한 비장과 흉선의 무게감소를 완전히 막아 주었다 (P<0.05, P<0.01). 한편 이와 유사하나 다소 적은 방사선 방호효과가 Cs 투여군의 고환에서도 관찰되었다. Cs 추출물의 투여는 ${\gamma}$ - 선 조사시 나타나는 조사 7 일째의 고혈당 효과를 억제하였다 (P<0.01). 그러나 조사된 기간 동안 혈청 콜레스테롤과 단백질의 수준에는 아무런 영향을 주지 않았다. 본 연구는 Cs가 방사선 방호효과를 보여주는 최초의 보고이다.

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Role of Oxidative Stress in the Radiation-Induced Lung Pathogenesis in Mice

  • Park, Eun-Mi;Park, Ji-Sun;Kim, Yun-Jeong;Sung, Jae-Suk;Hwamg, Tea-Sook;Kim, Woo-Chul;Han, Mi-Young;Park, Young-Mee
    • BMB Reports
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    • 제34권6호
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    • pp.544-550
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    • 2001
  • In pre-transplant total-body irradiation (TBI), the lung is a critical dose-limiting organ. Also, the possible role of oxidative stress was suggested in the development of TBI-induced lung damage. This study explores the association between TBI-induced oxidative stress and the induction of lung pathogenesis by investigating TBI-induced oxidative stress in the lungs of male C57BL/6 mice after a single dose of 10 Gy TBI. We showed significant increases of reactive oxygen species (ROS) formation and lipid peroxidation, and also a depletion and oxidation of glutathione after TBI. There is evidence that pretreatment with 1,10-phenanthroline (o-phen) significantly reduces oxidative stress in the lung. This indicates that the TBI-induced ROS generation involves a metal-catalyzed Fenton-type reaction. A pretreatment of buthionine sulfoximine (BSO) augmented the glutathione depletion and oxidation, but had no effect on the ROS formation and lipid peroxidation up to 6 h after TBI. Histopathological features that are consistent with pneumonitis were observed in the BSO pretreated-mice 1 week after irradiation. The results suggest that TBI-induced oxidative stress in the lung involves a generation of ROS through a Fenton-type reaction. Also, glutathione plays an important inhibitory role in the radiation-induced lung pathogenesis by participating in the self-amplifying cascade subsequent to the ROS generation by irradiation.

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저선량 방사선이 고추의 초기생육과 후속고선량 내성에 미치는 영향 (Effects of Low Dose Gamma Radiation on the Early Growth of Pepper and the Resistance to Subsequent High Dose of Radiation)

  • 김재성;백명화;김동희;이영근;이영복
    • 환경생물
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    • 제19권1호
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    • pp.71-77
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    • 2001
  • 저선량 방사선 조사한 고추 2품종, 조광고추와 조흥고추의 종자 발아율과 초기생육 및 고추 유식물체의 후속 고선량에 대한 내성 변화를 알아보고자 저선량 0, 4, 8, 20, 50 Gy를 조사하여 재배한 고추 유식물체에 ${\gamma}$선 50 Gy와 100 Gy를 조사한 후 생육상황을 관찰하였다. 저선량 조사한 고추 유식물체의 초기생육 촉진과 후속고선량 내성은 품종에 따라 달랐는데, 조광고추보다 조홍고추 품종에서 뚜렷한 증가효과를 나타냈고 발아율과 초기생육촉진은 4, 8, 20 Gy 조사구에서 효과적이었다. 조홍고추 유식물체의 후속고선량에 대한 내성은 사전 저선량 조사에 의해 크게 증가되었는데 특히 4Gy조사구에서 효과가 가장 뚜렷하였으며 후속고선량에 대해 내성이 증진된 고추 유식물체중의 carotenoid와 단백질 함량 및 CAT활성은 4 Gy와 8 Gy 조사구에서 높았다.

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Yellowing Inhibition of Bagasse Chemimechanical Pulp

  • Andulkhani Ali;Mirshokraie Seyed Ahmad;Latibari Ahmad Jahan;Enayati Ali Akbar
    • 한국펄프종이공학회:학술대회논문집
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    • 한국펄프종이공학회 2006년도 PAN PACIFIC CONFERENCE vol.2
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    • pp.337-347
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    • 2006
  • Papers made from unbleached and bleached bagasse chemimechanical pulp were chemically modified by acetylation. The effects of irradiation on unbleached and bleached also reduced papers of bagasse chemimechanical pulp before and after acetylation were investigated in this study. Chemimechanical pulp was prepared from bagasse and then bleached with hydrogen peroxide. Unbleached and hydrogen bleached pulps were reduced by Sodium borohydride in different procedures. Paper sheets were prepared from pulps and then acetylated using a technical grade of acetic anhydride. Accelerated photo-aging was run on the samples using fluorescent lamps to verify photo-stability of paper sheets before and after pretreatments. Brightness reversion (as Post-color number) and other optical properties of the paper sheets were measured. Efficient inhibition of photo-yellowing of papers made from bagasse CMP was achieved by acetylation. The acetylated unbleached CMP was noticeably photo-bleached during irradiation. Sodium borohydride reduction followed by acetylation had the same effect as acetylation alone at the same degree of reaction time and reductive treatment did not affect the yellowing rate to any great extent. The pre-reduced, acetylated unbleached papers were, however, not brightened during irradiation. Calculation done by Kubelka-Munk equation showed that reductive treatment had little effect in reducing the photo-yellowing of paper made from CMP pulp; a small stabilization effect was observed in the case of bleached CMP, while unbleached CMP was slightly more prone to discolor in the later phase of photo-reversion. The improved stability towards light may was closely related to the decrease in the phenolic hydroxyl content as a result of blocking by acetyl groups during treatment with acetic anhydride. The results support the hypothesis that phenolic hydroxyl has an important role in the process of photo-reversion of high-yield pulps. The results obtained in this study demonstrate that the acetylation of paper manufactured from peroxide bleached Bagasse CMP significantly retards light-induced discoloration. The inhibition of yellowing is connected with a decrease in the phenolic hydroxyl content of both unbleached and peroxide bleached papers.

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전자 빔을 이용한 폴리프로필렌 섬유의 PVP 하이드로젤 코팅 (PVP Hydrogel Coatings on Polypropylene Fibers using E-beam Irradiation)

  • 이지은;곽효빈;이용표;김경민;임정혁
    • 접착 및 계면
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    • 제20권2호
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    • pp.66-70
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    • 2019
  • 소수성 폴리프로필렌 섬유의 표면을 상압 플라즈마 공정을 이용하여 표면처리하였다. 친수성으로 개질된 섬유를 수용성 폴리비닐프롤리돈 (poly(N-vinylpyrrolidone, PVP) 코팅액에 딥코팅하여 PVP 막을 형성하였다. 섬유 표면에 코팅된 PVP 막은 15 kGy 선량의 전자 빔 조사를 통해 가교되어, 폴리프로필렌 섬유의 표면이 PVP 하이드로젤로 균일하게 코팅된 것을 확인하였다. PVP 하이드로젤 코팅막의 두께는 코팅액의 농도를 조절하여 제어할 수 있었다. 단계적인 표면처리, PVP 코팅, 그리고 하이드로젤 막의 형성에 따른 특성은 접촉각, 전자현미경, 광학현미경 등을 통해 분석되었다.

Application of the SCIANTIX fission gas behaviour module to the integral pin performance in sodium fast reactor irradiation conditions

  • Magni, A.;Pizzocri, D.;Luzzi, L.;Lainet, M.;Michel, B.
    • Nuclear Engineering and Technology
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    • 제54권7호
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    • pp.2395-2407
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    • 2022
  • The sodium-cooled fast reactor is among the innovative nuclear technologies selected in the framework of the development of Generation IV concepts, allowing the irradiation of uranium-plutonium mixed oxide fuels (MOX). A fundamental step for the safety assessment of MOX-fuelled pins for fast reactor applications is the evaluation, by means of fuel performance codes, of the integral thermal-mechanical behaviour under irradiation, involving the fission gas behaviour and release in the fuel-cladding gap. This work is dedicated to the performance analysis of an inner-core fuel pin representative of the ASTRID sodium-cooled concept design, selected as case study for the benchmark between the GERMINAL and TRANSURANUS fuel performance codes. The focus is on fission gas-related mechanisms and integral outcomes as predicted by means of the SCIANTIX module (allowing the physics-based treatment of inert gas behaviour and release) coupled to both fuel performance codes. The benchmark activity involves the application of both GERMINAL and TRANSURANUS in their "pre-INSPYRE" versions, i.e., adopting the state-of-the-art recommended correlations available in the codes, compared with the "post-INSPYRE" code results, obtained by implementing novel models for MOX fuel properties and phenomena (SCIANTIX included) developed in the framework of the INSPYRE H2020 Project. The SCIANTIX modelling includes the consideration of burst releases of the fission gas stored at the grain boundaries occurring during power transients of shutdown and start-up, whose effect on a fast reactor fuel concept is analysed. A clear need to further extend and validate the SCIANTIX module for application to fast reactor MOX emerges from this work; nevertheless, the GERMINAL-TRANSURANUS benchmark on the ASTRID case study highlights the achieved code capabilities for fast reactor conditions and paves the way towards the proper application of fuel performance codes to safety evaluations on Generation IV reactor concepts.

Ginseng root-derived exosome-like nanoparticles protect skin from UV irradiation and oxidative stress by suppressing activator protein-1 signaling and limiting the generation of reactive oxygen species

  • Wooram Choi;Jeong Hun Cho;Sang Hee Park;Dong Seon Kim;Hwa Pyoung Lee;Donghyun Kim;Hyun Soo Kim;Ji Hye Kim;Jae Youl Cho
    • Journal of Ginseng Research
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    • 제48권2호
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    • pp.211-219
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    • 2024
  • Background: Recently, plant-derived exosome-like nanoparticles (PDENs) have been isolated, and active research was focusing on understanding their properties and functions. In this study, the characteristics and molecular properties of ginseng root-derived exosome-like nanoparticles (GrDENs) were examined in terms of skin protection. Methods: HPLC-MS protocols were used to analyze the ginsenoside contents in GrDENs. To investigate the beneficial effect of GrDENs on skin, HaCaT cells were pre-treated with GrDENs (0-2 × 109 particles/mL), and followed by UVB irradiation or H2O2 exposure. In addition, the antioxidant activity of GrDENs was measured using a fluorescence microscope or flow cytometry. Finally, molecular mechanisms were examined with immunoblotting analysis. Results: GrDENs contained detectable levels of ginsenosides (Re, Rg1, Rb1, Rf, Rg2 (S), Gyp17, Rd, C-Mc1, C-O, and F2). In UVB-irradiated HaCaT cells, GrDENs protected cells from death and reduced ROS production. GrDENs downregulated the mRNA expression of proapoptotic genes, including BAX, caspase-1, -3, -6, -7, and -8 and the ratio of cleaved caspase-8, -9, and -3 in a dose-dependent manner. In addition, GrDENs reduced the mRNA levels of aging-related genes (MMP2 and 3), proinflammatory genes (COX-2 and IL-6), and cellular senescence biomarker p21, possibly by suppressing activator protein-1 signaling. Conclusions: This study demonstrates the protective effects of GrDENs against skin damage caused by UV and oxidative stress, providing new insights into beneficial uses of ginseng. In particular, our results suggest GrDENs as a potential active ingredient in cosmeceuticals to promote skin health.