• Title/Summary/Keyword: Electron beam irradiation

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Optimization of Cultivation and Storage Conditions on Red Cabbage Seed Sprouts (적양배추 새싹채소의 발아 및 저장 조건 최적화)

  • Baek, Kyeong-Hwan;Jo, Doekjo;Yoon, Sung-Ran;Kim, Gui-Ran;Park, Ju-Hwan;Lee, Gee-Dong;Kim, Jeong-Sook;Kim, Yuri;Han, Bumsoo;Kwon, Joong-Ho
    • Korean Journal of Food Science and Technology
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    • v.45 no.1
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    • pp.13-19
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    • 2013
  • This study was carried out to find the optimal conditions for red cabbage seed sprouts in terms of their physicochemical and sensory qualities by electron-beam irradiation, cultivation and storage using the response surface methodology (RSM). Moisture content ($R^2$=0.9638) was affected by irradiation dose and cultivation time. Total phenolics content ($R^2$=0.9117) was mainly affected by irradiation dose, but carotenoid content ($R^2$=0.8338) was affected in the order of irradiation dose, cultivation time and storage time. Sensory properties were also affected by irradiation dose, and thus scores decreased as irradiation dose increased. The optimum conditions estimated by superimposing total phenolics content and overall acceptance were 2.2-3.8 kGy of the irradiation dose, 3.0-4.0 days of cultivation and 2.0-3.0 days of storage.

Sticking Characteristics in BiSrCaCuO Thin Film Fabricated by Layer-by-Layer Sputtering Method (순차 스퍼터법으로 제작한 BiSrCaCuO 박막의 부착 특성)

  • Cheon, Min-Woo;Park, Yong-Pil;Kim, Jeong-Ho
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2003.05d
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    • pp.45-48
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    • 2003
  • BiSrCaCuO thin films were fabricated by atomic layer-by-layer deposition using an ion beam sputtering method. 10 wt% and 90 wt% ozone mixed with oxygen were used with ultraviolet light irradiation to assist oxidation. At early stages of the atomic layer by layer deposition, two dimensional epitaxial growth which covers the substrate surface would be suppressed by the stress and strain caused by the lattice misfit, then three dimensional growth takes place. Since Cu element is the most difficult to oxidize, only Sr and Bi react with each other predominantly, and forms a buffer layer on the substrate in an amorphous-like structure, which is changed to $SrBi_2O_4$ by in-situ anneal.

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히아론산 내 미생물과 물성에 대한 전자빔의 영향

  • Hong, Jeong-Hyeon;Park, Hong-U;Jeong, Gyu-Seon;Bae, Yeong-Chan
    • 한국생물공학회:학술대회논문집
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    • 2000.04a
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    • pp.185-188
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    • 2000
  • Disinfection and molecular weight changes by electron beam irradiation has been examined. Before radiation, the viscosity of oven-dried HA decreased about 30% but the viscosity of vacuum-dried HA did not decrease. The number of viable cell depends on the relative humidity(RH). The cell number decreased about 30% in RH 0% and about 10% in RH 100%. After radiation, the decrease in the molecular weight of the hyaluronic acid was larger in the RH=0% than in the RH=100% and was larger in the vacuum-dried HA than in the oven-dried HA. The extent of disinfection were similar for all form.

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Space Charge Analysis in Polymer Irradiated by Quasi-Monoenergetic Electron Beam (전자빔 조사에 의한 폴리머 내의 공간 전하 분석)

  • Choi, Yong-Sung;Kim, Hyung-Gon;Moon, Jong-Dae;Lee, Kyung-Sup
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2008.04c
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    • pp.62-66
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    • 2008
  • Spacecrafts such as most of commercial satellites that are operating in the geostationary orbit can be subjected to intense irradiation by charged particles. The surface made of dielectric materials can therefore become probable sites for damaging electrostatic discharges. Thanks to a specially equipped chamber, the spatial environment can be reproduced experimentally in the laboratory. In this paper, the behavior of high energy electrons injected in polymers such as PolyMethylMetaAcrylate (PMMA) and Kapton is studied. Results obtained by surface potential technique, pulse-electro acoustic device and a cell based on the split Faraday cup system are analyzed and discussed.

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Interfacial and Thermal Characteristics of Natural Fiber Composites Reinforced with Henequen Surface-Treated with EBI

  • Pang Yansong;Han Seong Ok;Cho Donghwan;Drzal Lawrence T.
    • Proceedings of the Korean Society For Composite Materials Conference
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    • 2004.10a
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    • pp.88-91
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    • 2004
  • In this study, a number of natural fiber henequen reinforced polymer matrix composites were successfully fabricated by means of a compression molding technique using chopped henequen fibers surface-treated with different electron beam irradiation (EBI) dosages, thermoplastic poly(butylene succinate), thermosetting unsaturated polyester and phenolic resins. Their interfacial and thermal characteristics were studied in terms of interfacial shear strength, fracture surface, dynamic mechanical properties, dimensional stability, and thermal stability using single fiber microbonding test, SEM, DMA, TMA, and TGA. The results show that their interfacial and thermal properties significantly depend on the intensity of EBl treatment on the natural fiber surface.

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Effect of Stereoregularity on the Properties of Syndiotacticity-Rich Ultrahigh Molecular Weight Poly(vinyl alcohol)/Dimethylsu1foxide/Water Gel

  • Park, Jin-Hyun;Lyoo, Won-Seok;Ko, Sohk-Won
    • Proceedings of the Korean Fiber Society Conference
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    • 1998.10a
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    • pp.13-16
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    • 1998
  • Poly(vinyl alcohol) (PVA) gels are easily formed via physical pathway. Most PVA solutions including PVA/water solution are well known to form thermally reversible gels at low temperature but these gels showed poor mechanical properties. In order to overcome this weak point, transparent crosslinked PVA hydrogels were prepared by electron beam irradiation or by chemical process with crosslinking agents or additives. (omitted)

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Enhanced Photodetection with Hot Electrons in Graphene-mediated Plasmonic Nanostructure

  • Kim, Jeong Hyeon;Yeo, Jong-Souk
    • Proceedings of the Korean Vacuum Society Conference
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    • 2014.02a
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    • pp.408-408
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    • 2014
  • Graphene has received attention with its high electron mobility and visual transparency as a promising material for optoelectronic and photonic applications. Combination of graphene and conducting nanostructures i.e. plasmonic structures has recently been researched for enhancing light-matter interaction and overcoming diffraction limit of light. Here we show enhanced photodetection of incoherent visible light with graphene-mediated plasmonics. Gold nanoparticles fabricated by focused ion beam was used as an active element of photodetection and graphene was utilized as an interfacing material between nanostructures and electrodes. Hot electrons generated upon plasmon decay within nanoparticles pass over the potential barrier between nanostructure and graphene and give rise to a photocurrent with built-in electric field. We report 76.7% enhancement of photocurrent under resonant irradiation of fiber-coupled halogen lamp compared to the case without light illumination. We showed wavelength-dependent current response arisen from plasmonic nanostructure, providing a good agreement with theoretical calculation.

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A Study on the VOC Decomposition Factors by Electron Beam Irradiation (전자빔 조사에 의한 VOC 분해 인자에 관한 연구)

  • Kim, Jo-Cheon;Kim, Gi-Jun;Jeon, Jin;Lee, Jae-Hyung;Park, Jong-Rae;Han, Beom-Su;Kim, Jin-Gyu
    • Proceedings of the Korea Air Pollution Research Association Conference
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    • 2002.04a
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    • pp.195-196
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    • 2002
  • 휘발성 유기화합물(Volatile Organic Compounds; VOCs)은 용제를 사용하는 도장공정, 석유화학공정 등 각종 산업공정과 자동차로부터 배출되어 대기중에 광화학 산화물을 형성하거나 그 자체로 발암성 또는 악취성을 나타내는 물질로 인체에 유해한 영향을 미치며, 한편 간접적으로 온실가스의 역할을 하는 것으로 알려졌다. 가속기를 이용한 전자빔 처리공정의 경우 상온에서 운영되고 2차오염물 발생이 거의 없으며, 특히 유량이 매우 크고 저농도로 배출되는 VOCs의 처리의 경우에 기존의 처리법 보다 더욱 경제적이고 효율적으로 적용될수 있다. (중략)

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Rapid crystallization of Cu-In-Ga-Se precursors by electron beam irradiation (전자빔 조사를 이용한 CIGS 박막 결정화 특성)

  • Im, Seon-Gyeong;Kim, Yeong-Man;Jeong, Chae-Hwan
    • Proceedings of the Korean Institute of Surface Engineering Conference
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    • 2015.11a
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    • pp.278-279
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    • 2015
  • CIGS 전구체는 각각 DC와 RF power로 셀레늄(Se)이 포함된 CuSe 타겟과 $(In,Ga)Se_2$ 타겟을 이용하여 스퍼터링 기법으로 증착한 후에 고속결정화 특성을 위해 전자빔을 조사하였다. 전자빔의 가속 전자의 강도(DC power)는 2.5~3.5keV로 조정하고 조사시간은 300초, RF power는 200W로 고정하였다. SEM image에서 전구체의 두께가 가속 전자의 강도에 따라 100~200nm의 손실됨을 확인할 수 있었다. XRD data 결과에서 3keV에서 조사된 샘플에서 가장 높은 (112) 피크의 특정 배양성을 보여 높은 결정화특성을 나타내었다. 조성비간의 변화를 보기 위해 XRF data 분석결과 전구체와 샘플간의 조성비의 차이는 그리 크지 않으나 I/III 족 비가 3 keV에서 가장 이상적인 비율이라 알려져 있는 1.0을 보였다.

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