• Title/Summary/Keyword: -irradiation

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Effect of Electron Irradiation on the Structural Electrical and Optical Properties of ITO/ZnO Thin Films (전자빔 조사에너지에 따른 ITO/ZnO 적층박막의 구조적, 전기적, 광학적 특성 변화)

  • Kim, Sun-Kyung;Kim, Daeil
    • Journal of the Korean Society for Heat Treatment
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    • v.27 no.5
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    • pp.225-229
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    • 2014
  • The influence of electron irradiation energy(eV) on the structural, electrical and optical properties of ITO/ZnO bi-layered films prepared with RF magnetron sputtering has been investigated. The ITO/ZnO show the lowest resistivity of $2.8{\times}10^{-4}{\Omega}cm$. The optical transmittance in a visible wave length region also increased with the electron irradiation energy. The film irradiated at 900 eV shows 82---- of optical transmittance in this study. By comparison of figure of merit, it was observed the optical transmittance and electrical resistivity of the films were dependent on the electron irradiation energy and optoelectrical performance of ITO/ZnO film is improved with electron irradiation.

Surface Photovoltage in Electron Beam Irradiation Semi-insulating GaAs

  • Yu, Jae-In;Lim, Jin-Hwan;Yu, Jae-Yong;Kim, Ki-Hong
    • Journal of Electrical Engineering and Technology
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    • v.1 no.4
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    • pp.543-545
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    • 2006
  • Surface photovoltage (SPV) measurements were performed to investigate the optic-electrical properties in the electron beam irradiation semi-insulating GaAs (e-beam irradiation SI-GaAs) and semi-insulating GaAs (SI-GaAs). The signal intensity showed stronge. dependency on the frequency in the SI-GaAs than it did in the e-beam irradiation SI-GaAs. This result indicates that the number of the generated photo-carriers depends on the surface state. Also, the B region of the e-beam irradiation SI-GaAs found a weak signal. This result was explained by the surface and internal damage with e-beam irradiation.

Application of Thermoluminescence to Detecting Post-Irradiation of Onion and Garlic (열발광기를 이용한 양파와 마늘의 방사선 조사 여부 검지)

  • ;;Ute Wagner;Georg A. Schreiber
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.27 no.1
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    • pp.63-68
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    • 1998
  • Irradiation can be utilized to inhibit sprouting of onions and garlic. Thermoluminescence(TL) is a potential method to detect post-irradiation of onions and garlic because they are irradiated with soil or dusts on them, from which minerals can be isolated for TL analysis. This study was to determine whether TL can be applied for the detection of post-irradiation of onions and garlic. Onions and garlic produced in Korea were irradiated in the range of 0.01~0.6kGy. Minerals isolated from the samples using sodium polytrungstate solution were used for TL analysis. The onions and garlic irradiated at 0.15kGy or higher could be detected with little errors. Minimum dose for the 2nd glow could be applied since the dose for the 2nd glow did not affect the results. The TL intensities of the temperature ranges of 229~295$^{\circ}C$ and 229~361$^{\circ}C$ and the maximum intensity provided more accurate information for the determination of the post-irradiation of onions and garlic.

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Effects of ${\gamma}$-Irradiation on the Volatile Organic Compounds from Cuscutae Semen (Cuscuta chinensis Lam) (감마선 조사가 기능성 식품 소재인 토사자의 휘발성 유기성분에 미치는 영향)

  • Yang, Su-Hyeong;Kim, Kyong-Su
    • Journal of Integrative Natural Science
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    • v.1 no.2
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    • pp.115-121
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    • 2008
  • This study was performed to examine the effect of ${\gamma}$-irradiation on the volatile organic compounds of Cuscutae Semen (Cuscuta chinensis L.). The volatile organic compounds of non-irradiated and 10 kGy ${\gamma}$-irradiated Cuscutae Semen were isolated using SDE apparatus and analyzed by GC/MS. Limonene, ethanol, (E)-2-decenal, hexadecanol, nonanoic acid and nonanal were detected as dominant compounds. Before irradiation, the total concentration of volatile organic compounds of Cuscutae Semen was approximately 189.90 mg/kg. After irradiation at 10 kGy, total concentrations increased to 299.46 mg/kg, but, the profile of volatile compounds including the essential oils of Cuscutae Semen was not differ from non- and irradiated sample. Therefore it was improved the extraction yield of useful compounds such as limonene, menthol, piperitone and isomenthone by irradiation.

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The Effect of LED Light Irradiation on Skin Injury Cure of Rat (LED 광원이 Rat의 피부 창상 치유에 미치는 영향)

  • Cheon, Min-Woo;Kim, Seong-Hwan;Park, Yong-Pil;Kim, Tae-Gon;Yu, Seong-Mi
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.20 no.12
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    • pp.1087-1092
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    • 2007
  • We developed the 4-channel Light Medical Therapy Apparatus for Skin Injury Cure using a high brightness LED. This equipment was fabricated using a micro-controller and a high brightness LED, and designed to enable us to control light irradiation time, intensity and reservation. In this paper, the designed device was used to find out how high brightness LED light affects the skin injury of SD-Rat(Sprague-Dawley Rat). In the experiment, $1\;cm^2$ wounds on the skin injury of SD-Rat(Sprague-Dawley Rat) were made. Light irradiation group and none light irradiation group divided, each group was irradiated one hour a day for 14 days. In result, compared with none light irradiation group, the lower incidence of inflammation and faster recovery was shown in light irradiation group.

The Effect of Red Ginseng Extracts on the Superoxide Dismutase, Peroxidase and Catalase Activities in the Liver of Gamma Ray Irradiated Mice (홍삼 투여가 방사선에 조사된 생쥐 간세포의 Superoxide Dismutase, Peroxidase 및 Catalase 활성도에 미치는 영향)

  • Chun, Chul;Chang, Che-Chul
    • Journal of Ginseng Research
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    • v.17 no.1
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    • pp.29-34
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    • 1993
  • This study was undertaken to investigate the effect of red ginseng extract (5.5 mg/mouse ip) on the activities of superoxide dismutase (SOD), peroxidase and catalase in the liver of the gamma ray irradiated male mice. The experimental groups consisted of control, red ginseng extract injection group, irradiation (8 $Gy^{60}$Co) group and red ginseng extract injection after irradiation group. in red ginseng extract injection group, SOD, peroxidase and catalase activities were similar to that in the control group. In irradiation group SOD, peroxidase and catalase activities increased progressively until the 2nd day after the treatment and then decreased thereafter, whereas red ginseng extract injection after irradiation group recovered more rapidly than irradiation group. The above results suggested that red ginseng extract injection after irradiation group have the recovery effects on the activities of SOD, peroxidase and catalase after radiation injury in the liver of male mice.

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Relationship between the pretilt angle generation and the polarization component with oblique polarized UV light irradiation on polyimide surface. (폴링미드표면에 편광된 UV광을 경사조사시의 프리틸트각의 발생과 편광성분의 상호관계)

  • 서대식;박두석
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.12 no.1
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    • pp.75-80
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    • 1999
  • In this study, we have investigated the relationship between the generation of pretilt angle and the polarization component in cells with UV light irradiation on polyimide (PI) surface. It was found that the generated pretilt angle is about $1.4^{\circ}$ with S-polarized UV light irradiation of $75^{\circ}$ on PI surface; it may be attributed to the asymmetry triangular of polymer surface with oblique S-polarized UV light irradiation on PI surface. Also, we measured that the generated pretilt angle is about $2.0^{\circ}$ with oblique P polarized UV light irradiation of $75^{\circ}$ on PI surface. Consequently, we suggest that the generated pretilt angle of the NLC is attributed to the interaction between the LC molecules and the polymer surface with oblique polarized UV light irradiation on PI surface.

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Berberine Inhibited Radioresistant Effects and Enhanced Anti-Tumor Effects in the Irradiated-Human Prostate Cancer Cells

  • Hur, Jung-Mu;Kim, Dong-Ho
    • Toxicological Research
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    • v.26 no.2
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    • pp.109-115
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    • 2010
  • The purpose of this study was to elucidate the mechanism underlying enhanced radiosensitivity to $^{60}Co\;{\gamma}$-irradiation in human prostate PC-3 cells pretreated with berberine. The cytotoxic effect of the combination of berberine and irradiation was superior to that of berberine or irradiation alone. Cell death and Apoptosis increased significantly with the combination of berberine and irradiation. Additionally, ROS generation was elevated by berberine with or without irradiation. The antioxidant NAC inhibited berberine and radiation-induced cell death. Bax, caspase-3, p53, p38, and JNK activation increased, but activation of Bcl-2, ERK, and HO-1 decreased with berberine treatment with or without irradiation. Berberine inhibited the anti-apoptotic signal pathway involving the activation of the HO-1/NF-${\kappa}B$-mediated survival pathway, which prevents radiation-induced cell death. Our data demonstrate that berberine inhibited the radioresistant effects and enhanced the radiosensitivity effects in human prostate cancer cells via the MAPK/caspase-3 and ROS pathways.

Effects of pH and Gamma Irradiation on the Physicochemical Properties of Corn Starch

  • Kang, Il-Jun;Chung, Cha-Kwon;Sohn, Jeong-In
    • Preventive Nutrition and Food Science
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    • v.4 no.3
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    • pp.175-179
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    • 1999
  • To develop a production method for modified starches with less pollution, pH adjustment and gamma irradiation were applied to commerical corn starch. Blue values were significantly decreased , while alkali number, optical transmittance and solubility markedly increased when gamma irradiation was applied to pH 2 adjusted corn starch. Water binding capacity and swelling power at pH 5 were the highest among the samples. Gelatinization viscosity was considerably affected by gamma irradiation and pH of the starch. Gamma irradiation of pH 2 adjusted starch showed the lowest peak viscosity and the best cooling stability among the tested samples . Therefore, the production of modified starch with low viscosity as well as with sufficient viscosity stability seems feasible by controlling the pH of the starch and gamma irrdiation.

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NMR Study of Poly(γ-Glutamic Acid)Hydrogels Prepared by γ-Irradiation : Characterization of Bond Formation and Scission

  • 한옥희;최혁준
    • Bulletin of the Korean Chemical Society
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    • v.20 no.8
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    • pp.921-924
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    • 1999
  • Hydrogels were prepared from poly( Υ-glutamic acid) (PGA) solution by g-irradiation of 90 kGy and 170 kGy. The hydrogels were more cross-linked with a higher dosage g-irradiation and completely hydrolyzed at 85℃ within 4 hours resulting in homogeneous solution. NMR techniques were employed to clarify chemical bond formation and scission involved during γ-irradiation and hydrolysis. Characterization of these samples was carried out by taking both liquid state and solid state NMR spectra of PGA and hydrolyzed hydrogels and comparison of these spectra with the solid state NMR spectra of hydrogels. Our results indicate that complicated chemical bond formation and scission have occurred during hydrolysis and γ-irradiation. The samples prepared with higher dosage of γ-irradiation showed more diverse chemical bond formation and scission.