• Title/Summary/Keyword: gamma-irradiated

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Determination of Two- Dimensional Distribution of Fission Products in the Irradiated Fuel Rod by Image Reconstruction Methods (비파괴적인 영상재구성 방법에 의한 조사 핵연료봉 단면내 핵분열 생성물의 이차원분포 결정)

  • Park, K.J.;Ro, S.G.
    • Journal of the Korean Society for Nondestructive Testing
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    • v.9 no.2
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    • pp.8-17
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    • 1989
  • Reconstruction of the radial two-dimensional of fission products using projections obtained by nondestructive transversal direction gamma scanning was evaluated, and then compared with the destructive sectional gamma scanning results. Although the nondestructive method has a little drawback compared to the destructive method in the accuracy, the former seemed to be sufficiently applicable.

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Electrical Properties of MOS Capacitors Irradiated with $CO^{60}-\gamma$ Ray ($CO^{60}-\gamma$선이 조사된 MOS Capacitors에서의 전기적 특성)

  • 권순석;박흥우;임기조;류부형;강성화
    • Journal of the Korean Vacuum Society
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    • v.4 no.4
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    • pp.402-406
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    • 1995
  • MOS(금속 산화막 반도체 접합) 소자가 방사선에 노출되면, 산화막재에 양의 공간전하가 생성되고 Si-SiO2 계면에 계면준위가 생성된다. MOS 커패시터의 방사선 조사효과를 방사선 피폭량과 산화막의 두께를 달리하는 시편에서 정전용량과 전류변화를 측정하여 고찰하였다. 정전용량-바이어스 전압 특성 실험결과로부터 플렛밴드 전압 및 계면상태밀도를 계산하였다. 또한 전압-전류 특성은 방사선 조사로 산화막내에 생성된 양의 공간전하와 Si-SiO2 계면에 포획된 전하에 의해서 설명이 가능하였다.

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Toxicity Evaluation of 30 kGy Irradiated Dried Space Bibimbap for Three Months (우주식품으로 개발한 30 kGy 감마선 조사된 건조우주비빔밥의 3개월 독성평가)

  • Park, Jae-Nam;Kim, Jin-Kyung;Choi, Dan-Bi;Kim, Jae-Hun;Song, Beom-Seok;Lee, Ju-Woon;Kang, Il-Jun
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.40 no.7
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    • pp.956-961
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    • 2011
  • This study was conducted to evaluate the possible subacute toxicity of gamma-irradiated dried bibimbap. The dried bibimbap was irradiated at the dose of 30 kGy at room temperature. For the animal study, the male and female ICR mice (8 mice per group) had the diet with AIN39G as control and dried bibimbap 30 kGy irradiated and non-irradiated for three months. During the experimental period, the group with 30 kGy irradiated bibimbap did not show any changes in appearance, behavior, mortality, body weight, organ weight, and food consumption compared to the control. Also, all of the biochemical parameters were observed in the normal ranges. In histopathological examination including hematological and serum biochemical analyses, there were no significant differences among the control and 30 kGy irradiated dried bibimbap groups. These results indicate that irradiation of bibimbap up to 30 kGy did not cause any toxic effects and could be applied for the development of safe ready-to-cook food.

Quartz Dissolution by Irradiated Bacillus Subtilis (방사선을 조사(照射)한 Bacillus Subtilis에 의한 석영 용해)

  • Lee, Jong-Un
    • Economic and Environmental Geology
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    • v.42 no.4
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    • pp.335-342
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    • 2009
  • The effects of bacterial lysis on the rate of quartz dissolution were investigated under pH 7 condition using Bacillus subtilis cells which were either irradiated or non-irradiated with gamma ray. The amount of dissolved organic carbon (DOC) which resulted from bacterial lysis increased in slurries of quartz and bacteria mixture over experimental period. Lysis of non-irradiated bacteria led to the elevated concentration of dissolved silicon when compared with abiotic control. Concomitant increase in the amounts of DOC and dissolved silicon over time indicated that lixiviation of silicon from quartz was due to bacterial lysis. Higher amounts of DOC and dissolved silicon were present in the irradiated bacterial slurries than those of non-irradiated bacteria. The enhancement of quartz dissolution in the irradiated bacterial slurries was likely attributed to disruption of organic molecules in the bacterial cells by gamma ray and formation of effective ligands for quartz dissolution. The results suggest that the effects of bacterial lysis on mineral weathering rate should be considered for prediction of time for released radionuclides to migrate to surface biosphere in high level radioactive waste disposal site.

Analytical Characteristics of Electron Spin Resonance for Identifying Irradiated Ramen Soup with Radiation Sources (방사선 조사된 라면수프의 조사선원에 따른 전자스핀공명 분석특성)

  • Ahn, Jae-Jun;Lee, Ju-Woon;Chung, Hyung-Wook;Kwon, Joong-Ho
    • Korean Journal of Food Science and Technology
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    • v.41 no.2
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    • pp.131-135
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    • 2009
  • The identification characteristics of irradiated commercial Ramen soup were investigated depending on radiation sources and doses by electron spin resonance (ESR) spectroscopy. Two commercial powder soups (RS-1, RS-2) were irradiated at 0 to 20 kGy under ambient conditions by both a Co-60 gamma irradiator and an electron beam (EB) accelerator, respectively. Crystalline sugar-induced multi-component signals with g-values of 2.010/2.011, 2.006, 2.002 and 1.999 were detected in the irradiated Ramen soup (RS-1, RS-2), whereas $Mn^{2+}$ signals were observed in non-irradiated samples, thereby distinguishing each other. Under the same analytical conditions, the intensity of ESR signals was higher in EB-irradiated samples than the gamma-irradiated ones. Determination coefficients ($R^2$) between irradiation doses and corresponding ESR responses were above 0.9665 in all the samples, and the magnetic field of specified g-value remained constant. The predominant ESR signals of $g_2$ (2.010-2.011) and $g_3$ (2.002) increased with corresponding doses of irradiation ($R^2$= 0.9750-0.9981).

Cooking Qualities in Gamma-Irradiated Chicken (감마선(線) 조사(照射)된 닭고기의 조리적성(調理適性))

  • Lee, Me-Kyung;Kim, Jong-Gun;Byun, Myung-Woo;Kwon, Joong-Ho;Cho, Han-Ok
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.14 no.2
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    • pp.151-156
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    • 1985
  • In order to develop a sanitary and economic storage method for chicken carcass by gamma-irradiation, the samples irradiated with 5 to 10 kGy were stored at 3 to $4^{\circ}C$ for 41 days, and the changes in ordour, appearance and the cooking guality of stored samples were determined. The nonirradiated samples which stored for more than 7 days were not tested because of microbial spoilage on the chicken carcasses. However, the quality of irradiated groups of 5 to 10 kGy was similar to that of fresh chicken for about 15 days though it deteriorated slightly after 20 days, however, they were still acceptable to eat each after 27 days of storage. The overall acceptability, flavor and texture was not significantly different in the samples of nonirradiated those of irradiated immediately and those of irradiated and then stored for 15 days when they were prepared for Sam Gei Tang arid steamed chicken. The acceptibility of Sam Gei Tang prepared with chickens after 15 days of the storage, the irradiated groups of 8 and 10 kGy showed a similarity to the chickens prepared immediately after slaughter. In steamed chickens prepared with the samples stored for 15 days texture of the irradiated group was superior to that of the nonirradiated fresh chicken, and there were no statistical differences in the flavors between each group.

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Changes of Free Radical Concentrations with Irradiation Dose and Storage Time in Gamma-Irradiated Sesame and Perilla Seeds (감마선 조사된 참깨, 들깨의 조사선량과 저장기간에 따른 free radical 농도의 변화)

  • Lee, Eun-Jeong;Yang, Jae-Seung
    • Korean Journal of Food Science and Technology
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    • v.34 no.3
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    • pp.396-399
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    • 2002
  • Electron spin resonance (ESR) spectroscopy was used to investigate the effect of irradiation dose and storage time on the free radical concentrations in gamma-irradiated sesame (Korean and Sudan) and perilla seeds (Korea). The samples were sealed with packed pyrex tube (50 g respectively) and then irradiated with doses of 0, 1, 5 and 10 kGy at room temperature using a Co-60 irradiator. Each sample in ESR quartz tube were calculated with ESR signals by Bruker-EPR spectrometer for 4 weeks. Free radicals detected for irradiated and unirradiated samples were higher than those of unirradiated ones. Since the free radical concentrations linearly incresed with the applied doses $(1{\sim}10\;kGy)$, highly positive correlation coefficients $(R^2=0.9926{\sim}0.9994)$ were obtained between irradiation doses and free radical concentrations right after irradiation. Although the free radical concentrations decreased with storage time, the signals of free radical in irradiated samples were observed even after 4 weeks of storage at room temperature.

Control of Postharvest Bacterial Soft Rot by Gamma Irradiation and its Potential Modes of Action

  • Jeong, Rae-Dong;Chu, Eun-Hee;Park, Duck Hwan;Park, Hae-Jun
    • The Plant Pathology Journal
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    • v.32 no.2
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    • pp.157-161
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    • 2016
  • Gamma irradiation was evaluated for its in vitro and in vivo antibacterial activity against a postharvest bacterial pathogen, Erwinia carotovora subsp. carotovora (Ecc). Gamma irradiation in a bacteria cell suspension resulted in a dramatic reduction of the viable counts as well as an increase in the amounts of DNA and protein released from the cells. Gamma irradiation showed complete inactivation of Ecc, especially at a dose of 0.6 kGy. In addition, scanning electron microscopy of irradiated cells revealed severe damage on the surface of most bacterial cells. Along with the morphological changes of cells by gamma irradiation, it also affected the membrane integrity in a dose-dependent manner. The mechanisms by which the gamma irradiation decreased the bacterial soft rot can be directly associated with the disruption of the cell membrane of the bacterial pathogen, along with DNA fragmentation, results in dose-dependent cell inactivation. These findings suggest that gamma irradiation has potential as an antibacterial approach to reduce the severity of the soft rot of paprika.

Trial to Identify Irradiated Corn Powder by Viscometric and Pulsed Photostimulated Luminescence (PPSL) Methods

  • Yi, Sang-Duk;Chang, Kyu-Seob;Yang, Jae-Seung
    • Journal of Food Hygiene and Safety
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    • v.16 no.1
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    • pp.82-87
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    • 2001
  • A study was performed to establish detection methods by viscometric and pulsed photostimulated luminescence (PPSL) methods for irradiated com powder. Viscosity was determined using a Brookfield DV-rotation viscometer at 3$0^{\circ}C$ and operated at 30, 60, 90, 120, 150, 180, and 210 rpm. All irradiated samples showed a decrease in Viscosity with increasing stirring speeds (rpm) and irradiation doses. Treatments at 1~3 kGy significantly decreased the viscosity. The photon counts of irradiated corn powder were measured by PPSL immediately after irradiation and exhibited an increase with increasing irradiation dose. The photon counts of irradiated com powder almost disappeared with lapse of time in room conditions, but detection of irradiation was still possible after one month at darkroom conditions. Consequently, these results suggest that the detection of irradiated com powder is possible by both viscometric and PPSL methods.

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