• 제목/요약/키워드: low temperature irradiation

검색결과 275건 처리시간 0.054초

감마선조사가 저장중 마늘의 생리적 특성에 미치는 영향 (Effect of Gamma Irradiation on the Physiological Characteristics of Garlic Bulbs During Storage)

  • 권중호;윤형식;손태화;변명우;조한옥
    • 한국식품과학회지
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    • 제16권4호
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    • pp.408-412
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    • 1984
  • 감마선 조사 (50, 100 및 500 Gy) 가 수확후 마늘의 생리적 특성에 미치는 영향을 검토하기 위하여 저온 $(3\;{\pm}\;1\;^{\circ}C$, R. H. 70-80%) 과 실온 $(12{\pm}\;5\;^{\circ}C$, R. H. 75-85%)에 10개월간 저장하면서 실험을 수행하였다. 마늘의 호흡량은 감마선 조사에 의해 일시적으로 자극되었으며, 기간의 경과에 따라 호흡량은 저장조건에 상당한 영향을 받았다. 모든 조사 (照射) 구와 저온 저장구는 저장 10개월까지 발아가 완전히 억제되었으나, 비조사구와 50Gy 조사구에서는 저장후 4 개월경부터 발근 현상을 보였다. 적정 선량의 감마선 조사는 저장중 마늘의 중량변화 및 변폐율의 감소효과를 나타내었으며, 이와 같은 현상은 비조사구 마늘이 발아되면서부터 유의적인 차이를 보였다. 또한 발아억제를 위한 감마선 조사는 마늘의 견고도에 영향을 미치지 않았다.

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저선량 감마선 반복조사의 육류와 생선 중 미생물 저감효과 (Reducing Effect of Microorganism on Meat and Fish Products by Repeated γ-Irradiation at Low Dose)

  • 제길수;정덕화;심원보
    • 한국식품위생안전성학회지
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    • 제30권1호
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    • pp.92-97
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    • 2015
  • 본 연구에서는 포장방법 (진공, 일반)과 저장온도($4^{\circ}C$, $-20^{\circ}C$)를 달리한 육류 (소고기, 닭고기) 및 생선에 대해 저선량 감마선 반복조사를 적용하였을 때 나타나는 병원성 미생물 E. coli O157:H7 및 S. Typhimurium의 사멸효과를 확인하였다. 소고기와 닭고기의 경우 E. coli O157:H7은 최소 2 kGy 이상의 단일조사와 0.5 kGy 이상으로 반복조사 시 생육이 확인되지 않았고, S. Typhimurium은 최소 2 kGy 이상의 단일조사와 1 kGy 이상으로 반복조사 시 생육이 확인되지 않았다. 생선의 경우 최소 0.5 kGy 이상의 단일 및 반복조사 시 E. coli O157:H7 와 S. Typhimurium의 생육이 확인되지 않았다. 육류보다 생선이 낮은 선량으로 미생물을 사멸시킬 수 있었으며, 전반적으로 포장 방법에 따른 조사선량의 차이는 없었으나 저장온도의 경우 냉장보다 냉동의 경우가 좀 더 높은 조사선량을 요구하는 것으로 확인되었다.

UV경화성 수지를 이용한 미세패턴 형성에 관한 연구 (A Study on Micro-patterning used the UV-Curable Resin)

  • 남수용
    • 한국인쇄학회지
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    • 제19권2호
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    • pp.68-78
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    • 2001
  • UV-curable resin has the properties of quick-drying, thigh productivity at low temperature, energy savint, space saving, solventless, non-polluting and low-stinking, and thus, UV-curing system has been widely used in the fields of printing inks, adhesives, paints and coating agents. This study has been executed to micro-patterning used UV-curable resin, The micro-patterning properties of this photoresist were investigated under irradiation of UV light low pressure mercury lamp. When the exposed photoresist film was developed by pure water developer, the resolution of this photoresist was about 50$\mu\textrm{m}$.

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마이크로 플라즈마를 이용한 피부암 세포의 자연사 유도 연구 (Research on the Apoptotic Death of Melanoma by the irradiation of Micro Plasma)

  • 손채화;김규천;이해준
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2007년도 Techno-Fair 및 추계학술대회 논문집 전기물성,응용부문
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    • pp.220-221
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    • 2007
  • Micro plasma has been recently studied to investigate the effects on various cells. We study a micro-plasma produced by a plasma needle that is operated with RF power and its effects on G361 melanoma cells. The micro plasma size ranges from sub-mm to several mm at a few watts of RF power. For the bio-medical treatment, low-temperature plasma is obtained and gas temperature is controlled within several tens of degrees $(^{\circ}C)$ in order not to disturb cell activities. Elementary spectroscopic studies to obtain plasma characteristics are presented for Ar and He plasma with different frequencies of RF power. Also the preliminary results of the micro plasma effects on G361 melanoma cells are presented. It was observed that the irradiation of micro plasma induces cell death through the deprivation of tyrosine phosphorylation in the G361 cells.

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자외선 조사된 HTV 실리콘 고무의 표면열화 분석 (Analysis of the Surface Degradation in UV-irradiated High-Temperature Vulcanized Silicone Rubber)

  • 연복희;이태호;허창수;이종한
    • 한국전기전자재료학회논문지
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    • 제13권5호
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    • pp.411-419
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    • 2000
  • In this paper we have investigated the surface degradation by ultraviolet-irradiation in high-temperature vulcanized silicone rubber. Through the measurement of surface potential decay by corona-charging and of contact angle it is found that the change of surface electrostatic properties and the decrease of contact angle under UV-radiation. For the changes in micro-morphological and chemical structure of the UV-treated silicone rubber we utilized several analytical techniques such as SEM, ATR-FTIR,XPS. From this study it is shown that the chemical reactions(scissoring of side chain(S-$CH_3$) cross-linking and branching) occur on the surface of silicone rubber during the UV-irradiation. Also we obtained the results of the loss of low molecular weight chain by cross-linking and oxidation reaction.

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IRRADIATION EMBRITTLEMENT OF CLADDING AND HAZ OF RPV STEEL

  • Lee J.S.;Kim I.S.;Jang C.H.;Kimura A.
    • Nuclear Engineering and Technology
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    • 제38권5호
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    • pp.405-410
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    • 2006
  • Microstructural features and their related mechanical property changes in the 309L cladding and the heat affected zone (HAZ) of SA508 cl.3 steel were investigated through the use of TEM, tensile and small punch (SP) tests. The specimens were irradiated at 563 K up to the neutron fluences of $5.79{\times}10^{19}n/cm^2$ (>1MeV). The microstructure of the clad was mainly composed of a fcc ${\gamma}-phase$, a low percentage of bcc ${\delta}-ferrite$, and a brittle ${\sigma}-phase$. Along the weld fusion line there formed a heavy carbide precipitation with a width of $20{\sim}40{\mu}m$, showing preferential cracking during plastic deformation. The yield stress and ductile-to-brittle transition temperature (DBTT) of the irradiated clads increased. The origin of the hardening and the shift of the DBTT are discussed in terms of the irradiation-produced defect clusters of a fine size and brittle ${\sigma}-phase$.

전자스핀공명을 이용한 저밀도 폴리에틸렌의 방사선 열화 검지 (Detection of Radiation Degradation of LDPE by ESR Spectroscopy)

  • 김기엽;이청;류부형
    • 한국안전학회지
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    • 제20권1호
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    • pp.81-86
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    • 2005
  • This study has investigated radiation degradation of low density polyethylene(LDPE). Samples were irradiated up to 800kGy using a $Co^{60}\;\gamma-ray$ at a dose rate of 5kGy/hr in the presence of air atmosphere at room temperature. After irradiation, storing for 2 weeks, free radical measurement of LDPE has established by electron spin resonance(ESR). ESR measurement showed that free radical concentration(FRC) was increased with radiation dose and decreased with the time. The radical types showed alkyl, allyl, and peroxy radical with the irradiation, these changed to peroxy radical with the time.

이온선 조사의 열충격 효과에 의한 grain 성장 (Grain Growth By The Thermal Spike Effect of the Ion Irradiation)

  • 김성수;송종환;채근화;주장헌;우정주;이임렬;황정남;김현경;문대원
    • 한국표면공학회지
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    • 제24권3호
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    • pp.137-143
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    • 1991
  • The relation between the ion irradiation induced grain growth and the basic parameters sinvolved in ion beam mixing process was studied. TEM micrographs showed that a significant grain growth has been induced by Ar+ irradiation at room temperature. The grain size increases rapidly in low dose region, while it approaches a saturated value in high dose region, and it has close relationship with nuclear energy deposition and thermodynamic properties such as cohesive energy ( Hc) and heat of mixing ( Hm). A model for the grain growth based on the thermal spike induced atomic migration was developed and applied to interpret experimental results.

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