• 전기전자학회논문지
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• 제15권2호
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• pp.143-148
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• 2011

MOS (Metal-Oxide Semconductor) devices among the most sensistive of all semiconductors to radiation, in particular ionizing radiation, showing much change even after a relatively low dose. The necessity of a radiation dosimeter robust enough for the working environment has increased in the fields of aerospace, radio-therapy, atomic power plant facilities, and other places where radiation exists. The power MOSFET (Metal-Oxide Semiconductor Field-Effect Transistor) has been tested for use as a gamma radiation dosimeter by measuring the variation of threshold voltage based on the quantity of dose, and a maximum total dose of 30 krad exposed to a $^{60}Co$ ${\gamma}$-radiation source, which is sensitive to environment parameters such as temperature. The gate oxide structures give the main influence on the changes in the electrical characteristics affected by irradiation. The variation of threshold voltage on the operating temperature has caused errors, and needs calibration. These effects can be overcome by adjusting gate oxide thickness and implanting impurity at the surface of well region in MOSFET.

• 한국식품과학회지
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• 제38권3호
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• pp.378-384
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• 2006

저선량의 감마선 조사(0-9.1 kGy)에 의하여 옥수수녹말의 고유 점도는 감소, 겉보기 아밀로오스 함량, 물 결합능력, 팽윤력과 용해도는 증가하였다. RVA 또는 아밀로그래프 점도는 조사선량이 증가함에 따라 감소하였으나 DSC에 의한 흡열 전이에는 큰 영향이 없었다. 감마선 조사한 옥수수 전분을 이용한 저항전분 생성은 효과가 없었다.

• 식물조직배양학회지
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• 제28권6호
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• pp.305-310
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• 2001

본 실험은 지치 (Lithospermum erythrorhizon)의 뿌리조직으로부터 유도한 캘러스에 ${\gamma}$선을 조사하여 배양기간과 배지조성 및 명.암배양의 조건에 따라 ${\gamma}$선 조사가 캘러스 생장촉진 효과가 있는지를 검토하고자 수행하였다. 지치의 캘러스 생장은 전체적으로 암배양에서보다 명배양에서 효과적이었다. r선 조사에 의한 효과에 있어서는 LLB2N2배지의 8 Gy에서 캘러스의 생장에 효과가 가장 좋았고, LLK2I0.2배지에서는 16 Gy에서 캘러스 생장효과가 좋았지만 암배양에서의 ${\gamma}$선처리 효과는 없었다. 명배양에서 LS배지에 BA 1 mg/L와 NAA 1 mg/L를 첨가할 경우, BA 2mg/L와 NAA 2 mg/L를 첨가할 때보다 캘러스의 생장효과가 있었으나, 암배양에서는 차이가 없었다. 특정선량에 대한 BA와 NAA의 농도에 있어서는 각각 2 mg/L가 효과적인 것으로 나타났다. MK2I0.2배지는 0.5 Gy와 1 Gy에서 캘러스의 생장에 효과적이었으나, 기본배지의 종류에 있어서는 MS배지보다 LS배지에서 더 효과적이었다. M-9배지에서는 명배양에서도 캘러스의 생장은 저조하였으나, 16 Gy 및 30 Gy에서 캘러스의 생장이 30%이상 증가하였다. 암배양에서는 ${\gamma}$선 조사에 의한 캘러스의 생장효과는 거의 없었다.

• KSBB Journal
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• 제26권6호
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• pp.565-568
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• 2011

In this study, it was investigated the antioxidant activity of laminarin degraded by gamma irradiation. Because the activities of antioxidants have been attributed to various mechanisms, different assay methods have been conducted and compared. 1,1-diphenyl-2-picryl-hydrazyl (DPPH) radical scavenging activity, ferric reducing antioxidant power, and lipid peroxidation inhibitory activity of degraded laminarin were measured and compared with non-degraded. All of these results showed that the antioxidant activity of laminarin degraded by irradiation was increased depending on the absorbed dose. Therefore, gamma irradiation could be an alternative method for the preparation of degraded laminarin with higher antioxidant activity.

• 한국환경농학회지
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• 제19권4호
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• pp.328-331
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• 2000

국내에서 재배중인 옥수수 재래종 (고성, 영월)품종의 종자에 저선량 ${\gamma}$선을 조사하여 초기생육과 수량에 미치는 영향을 온실과 포장실험으로 조사하였다. 저선량 방사선 조사가 옥수수 종자발아 및 초기생육에서 뚜렷한 촉진효과를 보였으나 품종별로 다소 차이가 있었으며 고성재래종은 2 Gy, 영월재래종은 12 Gy가 가장 효과적이었다. 포장생장과 수량에서도 저선량 조사에 의해 증가하는 경향을 보였는데 적정선량은 고성재래종은 8 Gy, 영월재래종은 $4{\sim}12$ Gy 범위로 나타났다.

• 한국식품영양과학회지
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• 제28권5호
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• pp.1076-1081
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• 1999

Physicochemical, microbiological, and sensory properties of barleys irradiated by gamma ray at 1.2kGy, 10.1kGy, or 30.5kGy were investigated every 40 days during the storage at 25℃ and 50% relative humidity. Moisture content of the irradiated barleys decreased but crude lipid content increased during the storage. TBA values increased in proportion to the irradiation dose and to the storage period. In Hunter's color, L, a, and b values of 30.5kGy dose irradiated barleys were higher than those of the non irradiated barleys right after irradiation and this trend continued during the storage. Numbers of mesophilic and psychrophilic bacteria in the non irradiated barleys and 1.2kGy dose irradiated barleys were higher than those in the barleys irradiated at 10.1kGy and 30.5kGy during the storage. Numbers of yeasts and molds in the irradiated and non irradiated barleys were low and they did not greatly increase during the storage. In sensory evaluation, acidic odor of the barleys was strong at the 10.1kGy and 30.5 kGy dose irradiation but barley odor and humid odor were not significantly different among the groups depending upon the radiation dose and storage period.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2008년도 학술대회 논문집 정보 및 제어부문
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• pp.165-168
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• 2008

The experimental results of exposing IGBT (Insulated Gate Bipolar Transistor) samples to gamma radiation source show shifting of threshold voltages in the MOSFET and degradation of carrier mobility and current gains. At low total dose rate, the shift of threshold voltage is the major contribution of current increases, but for more than some total dose, the current is increased because of the current gain degradation occurred in the vertical PNP at the output of the IGBTs. In the paper, the collector current characteristics as a function of gate emitter voltage (VGE) curves are tested and analyzed with the model considering the radiation damage on the devices for gate bias and different dose. In addition, the model parameters between simulations and experiments are found and studied.

• 상하수도학회지
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• 제26권3호
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• pp.373-381
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• 2012

Antibiotics have been issued recently in water environments because of potential impacts on ecosystem and public health. This study was aimed to investigating the degradation of antibiotics such as tetracycline, lincomycin, sulfamethazine and cephradine using gamma ray irradiation. And the toxicity before and after irradiation on antibiotics was tested in order to examine the aquatic eco-risk assessment by aquatic organisms. In addition, comparing tests on toxicity for gamma ray and UV irradiated antibiotics was conducted. Four different antibiotics were prepared by concentration of 30 mg/L with demi-water respectively. The absorption dose of gamma ray was ranged from 0.2 to 2 kGy. The concentration of four antibiotics was gradually decreased corresponding to the increase of the absorption dose. A method for toxicity assessment using Pseudokirchneriella subcapitata was evaluated to the most acceptable compared with methods by Daphnia magna and Microtox$^{(R)}$ in terms of sensibility. It showed that the reduction of toxicity on antibiotics treated by gamma ray was superior comparing to the test results obtained from UV treatment. By-products from antibiotics treated by gamma ray were easily decomposed by microorganism and their toxicity was also evaluated to low.

• 한국수산과학회지
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• 제55권3호
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• pp.302-309
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• 2022

Low-salt fermented pollack Theragra chalcogramma roe (Myungran Jeotgal, MJ), a traditional Korean fermented seafood, was prepared using a commercially available method and irradiated using gamma rays (0-10.0 kGy) to investigate the effect of gamma irradiation (GI) on food quality. After irradiation with 2.5 kGy gamma rays, the number of viable cells in MJ was reduced by one log compared to that observed in non-irradiated MJ, and no living cells were detected after 7.5 kGy GI. Though up to 2.5 kGy GI had no effect on color quality, over 7.5 kGy GI resulted in significantly poor quality MJ surface color. Saturated fatty acid contents increased slightly in irradiated MJ, while those of polyenes and monoenes decreased slightly as the GI dose increased. Exposure of MJ to GI had no effect on the free amino acid and mineral composition. These results demonstrated that the appropriate GI dose for MJ ranged from 2.5 to 5.0 kGy, which may be recommended for industrial application.

• Fisheries and Aquatic Sciences
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• 제18권2호
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• pp.115-121
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• 2015

This study was conducted to confirm quality properties of sterilized Ganjang-gejang (marinated crab Portunus trituberculatus) with Korean soy sauce using by gamma irradiation and to improve quality of sterilized Ganjang-gejang. The Ganjang-gejang was irradiated at dose of 3, 6, 9, 12, and 15 kGy by gamma irradiation and there was evaluated in microbiological, physicochemical, and sensory properties. Total aerobic bacteria and fungi contents of non-irradiated samples were about 6 and 4 log CFU/g level, respectively. Gamma-irradiated samples at above 9 kGy did not contain aerobic bacteria or fungi at detection limit less than 2 log CFU/g, but sensory scores were significantly decreased depending on the irradiation dose. To improve the sensory qualities of gamma-irradiated Ganjang-gejang, the temperature was adjusted during sample irradiation. When samples were irradiated under freezing temperatures, especially on dry ice, the TBARS and the deterioration of sensory qualities of Ganjan-Gejang were reduced. Different odor patterns were observed among samples, as observed using electronic nose analysis system. The results of this study indicated that treatment with irradiation under low temperatures may help to preparing high-quality Ganjang-gejang.