• 방사선산업학회지
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• 제5권2호
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• pp.175-178
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• 2011

This study was conducted with effect of lactic acid bacteria by gamma irradiation. Lactic acid bacteria were exposed to irradiation with a single absorbed dose of 1, 2, 3, 4, 5, 6, 8, and 10 kGy. Possible lactic acid bacteria, including Lactobacillus paracasei KCTC 13169, Lactobacillus casei KCTC 3109, Lactobacillus acidophilus KCTC 3140, Lactobacillus plantarum subsp plantarum KCTC 3103, Lactobacillus debruekii subsp bulgaricus KCTC 3635, Streptococcus thermophilus KCTC 3658 were selected. The radiation sesitivities of lactic acid bacteria were expressed as $D_{10}$ values. The $D_{10}$ values of Lactobacillus paracasei, Lactobacillus casei, Streptococcus thermophilus, Lactobacillus acidophilus, Lactobacillus plantarum, and Lactobacillus debruekii were calculated as 0.42, 0.51, 0.47, 0.90, 0.44, and 0.61 kGy, respectively. Results suggest that L. acidiphilus has the highly resistant to gamma irradiation.

• 한국환경농학회지
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• 제19권4호
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• pp.324-327
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• 2000

저선량 조사한 대두종자의 초기생육과 대두 유식물체의 후속고선량에 대한 방사선 감수성 변화를 알아보고자 저선량 0, 4, 8, 12, 20 Gy를 조사하여 재배한 대두 유식물체에 ${\gamma}$선 50, 100, 200 Gy를 조사한 후 생육상황을 관찰하였다. 저선량 조사에 의해 대두 신규종자의 발아율 증가효과는 없었으나 작물 생장 증대효과는 있었으며 저선량 8 Gy 조사구가 가장 효과적이었다. 대두유식물체의 고선량 방사선에 의한 생육장해는 사전 저선량조사에 의해 크게 감소되었으며 저선량 조사에 의한 고선량 방사선 저항성 증가는 8 Gy와 20 Gy조사에서 가장 효과적이었다.

• 원예과학기술지
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• 제34권1호
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• pp.122-133
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• 2016

While ion beams are widely used in plant breeding, little is known about the sensitivity of Lavandula angustifolia (lavender) to ionizing radiation. To compare the biological effects of different types of ionizing radiation on the germination and survival rates of lavender, we exposed lavender seeds to gamma rays, 3 MeV electron beams, and 1.89 MeV proton ion beams. We observed that the seed germination rate decreased with increasing dosages of all three types of ionizing radiation. The malformation rate of lavender seedlings exposed to electron beams and gamma rays increased with increasing radiation dosage. By contrast, the effect of the accelerated proton beams on the malformation rate was negatively correlated with the dosage used. The survival rate of lavender seedlings exposed to the three types of ionizing radiation decreased in a dose-dependent manner. In addition, the survival rate of seedlings irradiated with proton and electron beams decreased more slowly than did that of seedlings irradiated with gamma rays. The half-lethal dose of gamma rays, electron beams, and proton beams was determined to be 48.1 Gy, 134.3 Gy, and 277.8 Gy, respectively, and the most suitable proton-ion energy for lavender seeds in terms of penetration depth was determined to be 5 MeV. These findings provide valuable information for the breeding of lavender by radiation mutation.

• 방사선산업학회지
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• 제4권3호
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• pp.277-283
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• 2010

Rape (Brassica napus L.) plants are one of the major oilseed crops. The main components of rapeseed are oil (35 to 47%) and protein (15 to 32%). For the biodiesel production, the development of a new variety of rape plant with high biomass and/or oleic acid contents is required. In order to determine the optimum dose of gamma-ray irradiation, the rape seeds of cvs. Hanra (Hr), Youngsan (Ys), Tammi (Tm), and Tamra (Tr) were irradiated with a 100~4,000 Gy dose range of gamma-rays. Considering the growth factors, the optimum doses were determined to be within the range of 600~1,000 Gy for the selection of useful mutant lines. Six-hundred and eighty-eight (688) $M_2$ mutant lines were obtained from 600~1,000 Gy gamma-ray-irradiated $M_1$ plants through selfing. The growth characteristics, leaf shape, early flowering, and flower color were all investigated. The selected mutant numbers of early flowering, leaf shape, and flower color were 34, 52, and 3 from the four cultivars, respectively. These mutant lines will be used for the development of a new variety of rape plant with high biomass and oleic acid contents.

• 방사선산업학회지
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• 제6권3호
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• pp.239-244
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• 2012

This study was conducted to investigate bacterial growth, viscosity, color, and sensory properties of gamma-irradiated Tarakjuk powder, a Korean milk porridge powder, at 1, 3, 5, 7, and 10 kGy. The total aerobic bacteria in non-irradiated Tarakjuk powder was $2.56{\log}\;CFU{\cdot}g^{-1}$, whereas it was not observed within the detection limit of $2{\log}\;CFU{\cdot}g^{-1}$ in samples irradiated at more than 1 kGy. Spore-forming bacteria, however, were not observed in all samples within the detection limit of $1{\log}\;CFU{\cdot}g^{-1}$. The viscosity of rehydrated Tarakjuk after gamma irradiation significantly decreased from 16,770 cP to 4,060 cP when irradiated at 10 kGy. The redness ($a^*$ value) and yellowness ($b^*$ value) evaluated using a colorimeter were significantly increased according to the increase in irradiation dose (p<0.05), while there was no difference in color evaluation conducted by panels. The overall acceptance decreased as the irradiation dose increased, and the 5 kGy sample was 4.0 (normal) on a 7-point scale. As a result, it is considered that a gamma irradiation of 5 kGy is enough to sterilize Tarakjuk powder with a acceptable sensory quality.

• Journal of Radiation Protection and Research
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• 제19권2호
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• pp.147-156
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• 1994

환경감마선량 변동을 감시하기 위해 한국원자력연구소 부지 주변에 온라인 감마선량 감시망을 구성하였다. 모니터링 포스트에 설치된 전리함 검출기에 의해 측정된 자료는 무선전송 방식으로 중앙동제소에 전송되어 실시간으로 감시된다. 무선전송 방식은 자료의 전송, 처리 및 저장에 신뢰도가 높고 경제적이었다. 감시시스템은 급격한 선량증가시 조기경보체제와 연결할 수 있게 하였다.

• 한국안전학회지
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• 제18권4호
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• pp.64-70
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• 2003

The thermal properties of chloroprene rubber (CR) with $^{60}Co\;{\gamma}$-ray irradiation has been investigated. The prepared CR was irradiated up to 1000kGy radiation dose by $^{60}Co\;{\gamma}$-ray and the radiation degradation of CR was investigated by thermogravimetric analysis and differential acanning calorimetry. Dynamic mechanical properties measurement and FT-IR observation are carried out as well. From these analyses results, the glass transition temperature($T_g$), decomposition onset temperature(DOT), oxidative induction time(OIT), the peak temperature of loss modulus and mechanical tan ${\delta}$ values were compared for the radiation degradation level of CR. The tendency between $T_g$ and peak temperature of loss modulus and mechanical tan ${\delta}$ agreed well with radiation doses. Decomposition temperature, OIT and DOT showed the same tendencies as increasing radiation doses. It was verified that these analyses are available to estimate the degradation level of CR.

• 방사선산업학회지
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• 제8권1호
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• pp.17-22
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• 2014

In this study, we prepared CdTe/CdS solar cells using a thermal vacuum evaporation method. In particular, $CdCl_2$ treatment was attempted using this same method at $400^{\circ}C$ for 30 min. The prepared CdTe/CdS solar cells were investigated using Fouier transform infrared spectrometry (FTIR), field emission scanning electron microscopy (FE-SEM), and a solar simulator system including light absorption properties, morphological properties, and power conversion efficiency (PCE). In addition, we investigated the gamma-irradiation treatment at dose rates of 0 Gy, 500 Gy, 1 kGy, 10 kGy, and 30 kGy. The characteristics of gamma-irradiation treatment were studied based on the same method described above. In particular, it showed increased values as 0.826% higher than the non-irradiation of 0.448% from PCE analysis.

• 방사선산업학회지
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• 제5권4호
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• pp.377-382
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• 2011

Poly(vinyl alcohol) (PVA) is an interesting material with good biocompatibility, high elasticity and hydrophilic chacrateristics. In this study, crosslinked hydrogels based on PVA, and poly(acrylic acid) (PAAc) were prepared by gamma-ray irradiation. PVA and PAAc powders were dissolved in deionized water, and then irradiated by a gamma-ray with a radiation dose of 50 kGy to make hydrogels. The hydrogels were then annealed in an oven at $120^{\circ}C$ for 10 min, 30 min and 50 min under nitrogen atmosphere. The properties of a hydrogel such as gel fraction, swelling behavior, thermogravimetric analysis (TGA) and adhesive strength as a function of PAAc content and annealing time were investigated. The gel fraction decreases with decreasing PAAc content and increasing annealing time. The thermal behaviors have shown different patterns according to the annealing time. The adhesive strength increases with increasing PAAc content.

• 전기학회논문지
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• 제59권9호
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• pp.1611-1614
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• 2010

The explosion of a nuclear weapon radiates a gamma-ray in the form of a transient pulse. If the gamma-ray introduces to semiconductor devices, much Electron-Hole Pairs(EHPs) are generated in depletion region of the devices[7]. as a consequence of that, high photocurrent is created and causes upset, latchup and burnout of semiconductor devices[8]. This phenomenon is known for Transient Radiation Effects on Electronics(TREE), also called dose-rate effects. In this paper 3D structure of inverter and NAND gate device was designed and transient pulse gamma-ray was modeled. So simulation for transient radiation effect on inverter and NAND gate was accomplished and mechanism for upset and latchup was analyzed.