• Toxicological Research
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• 제20권2호
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• pp.117-122
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• 2004

The present study was carried out to establish a short-term teratogenicity study for detecting developmental toxic potential induced by gamma radiation in ICR mice. Pregnant mice were exposed at dose levels of 0, 0.5, 1, 2, or 4 Gy on gestational day 8.5. All dams were subjected to caesarean section on gestational day 10.5 and their embryos were examined for growth, differentiation, and morphological abnormalities. An increase in the number of resorption was found at 4 Gy in a dose-dependent manner. Dose-dependent decreases in the developmental score of yolk sac circulation and olfactory system at above 1 Gy, in the number of somite pairs and developmental score of allantois, optic system, and maxillary process at above 2 Gy, and in the all growth and developmental parameters examined at 4 Gy were found. Various types of morphological abnormalities were seen at dose levels of 0.5 Gy or greater. Characteristic malformations induced by gamma radiation were abnormal axial rotation, hematoma, craniofacial hypoplasia, open neuropore, shortened prosencephalon, kinked somites, irregular somites, swelling, hydropericardium, absent branchial bar, and absent limb bud. Morphological alterations such as hematoma, craniofacial hypoplasia, open neuropore, and kinked somites were noted even in the lowest dose (0.5 Gy). These results indicated that the short-term teratogenicity study established in this study can be a useful tool for not only detecting the developmental toxic potential induced by gamma radiation, but also screening radio-protective agents in ICR mice.

• 식물조직배양학회지
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• 제26권4호
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• pp.265-269
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• 1999

고구마 산성 peroxidase (POD) (swpal) 또는 중성 POD(swpnl)을 도입한 형질전환 담배에 다양한 선량의 감마선을 조사한 후 30일에 항산화효소 활성과 식물생장에 미치는 영향을 조사하였다. 감마선은 조사선량에 비례하여 형질전환 식물체와 정상식물에 관계없이 모든 식물체의 생장을 크게 억제시켰다. 50-70 Gy 처리에서 식물체의 신장이 크게 억제되었고 새로운 잎이 발생되지 못하였다. 10-50 Gy의 조사선량에서는 POD, superoxide dismutase, catalase 활성에 큰 변화를 주지 않았다. 이러한 결과는 고구마 POD는 감마선 조사에 의해 유도되는 산화적인 스트레스에 대한 보호효과에 관여하지 않음이 시사된다.

• 방사선산업학회지
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• 제2권1호
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• pp.9-14
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• 2008

Livestock wastewater containing high concentrations of organic matters and ammonia-nitrogen has been known as one of the recalcitrant wastewater. It is difficult to treat by conventional wastewater treatment techniques. This study was carried out to evaluate the feasibility of zeolite ion exchange and gamma-ray irradiation treatment of livestock wastewater. The removal efficiencies of $SCOD_{Cr}$ and $NH_3-N$ were significantly enhanced by gamma-ray irradiation after zeolite ion exchange as a pre-treatment. However, the effects of zeolite particle size on the $SCOD_{Cr}$ and $NH_3-N$ removal efficiencies were insignificant. These results indicate that the combined process of zeolite ion exchange and gamma-ray irradiation has potential for the treatment of livestock wastewater.

• Nuclear Engineering and Technology
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• 제51권6호
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• pp.1626-1632
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• 2019

Monitoring of environmental radioactivity is essential for ensuring the radiological safety of residents who live near nuclear power plants. Ulsan, South Korea, is surrounded by 16 nuclear power plants, the highest density in the country. In addition, the city contains facilities for conducting radiological nondestructive testing and using radioisotopes for medical purposes. It makes the confirmation of radiological safety particularly necessary. In this study, sampling points were selected based on regional characteristics, and surface water samples were pretreated and analyzed for gross beta and gamma radiation levels. In addition, the distribution of the city's gamma dose rate was determined using a mobile monitoring system and distribution visualization program. The results showed that there is no effect on the gross beta and gamma nuclides of artificial radionuclides, and the gamma dose rate of the entire region did not exceed the environmental radiation level in South Korea overall, confirming the radiological safety of the city.

• Fibers and Polymers
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• 제5권2호
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• pp.156-159
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• 2004

Novoloid fibers have high chemical, flame and thermal resistance; however they have low tensile properties. Effects of gamma irradiation on the tensile properties of novoloid fibers have been investigated. Loop and knot resistance have also been examined. Maximum tenacity of the single fiber increased with an increase of the radiation dose applied. According to the loop and knot tenacity results it is found that brittleness has been also affected by the amount of radiation dose.

• 한국의학물리학회:학술대회논문집
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• 한국의학물리학회 2006년도 제33회 추계학술대회 발표논문집
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• pp.66-66
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• 2006

• Food Science and Biotechnology
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• 제17권5호
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• pp.1003-1009
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• 2008

This study was performed to determine the effects of $\gamma$-irradiation on the antiallergic activity of alginate. An alginate aqueous solution was $\gamma$-irradiated at 3, 5, 7, 10, 20, and 100 kGy. First, the molecular weight (Mw) of alginate rapidly decreased as the $\gamma$-irradiation dose increased up to 20 kGy. Then, the antiallergic activity of the $\gamma$-irradiated alginate was measured. Interlukin (IL)-4 cytokine and IgE level were significantly decreased in the $\gamma$-irradiated alginate groups as compared to the control group in vitro. The mice intraperitoneally administered with the $\gamma$-irradiated alginate exhibited lower ovalbumin-specific IgE and IgG1 level in serum than the control mice. Furthermore, the $\gamma$-irradiated alginate suppressed total and ovalbumin-specific IgE secretions in the splenocytes. Increased IL-2 level was observed in the culture supernatants of the splenocytes that were obtained from the mice administerd with the $\gamma$-irradiated alginate, while IL-4 level decreased. The present study indicates that $\gamma$-irradiated alginate can suppress allergy in a mouse allergy model.

• 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.

• KIEE International Transactions on Electrophysics and Applications
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• 제3C권2호
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• pp.48-54
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• 2003

To evaluate the radiation degradation of ethylene propylene rubber (EPR), radiation effects on EPR were investigated by using dielectric analysis and thermal-gravimetric analysis. Permittivity, loss factor, tan$\delta$, and thermal decomposition temperature were observed for ${\gamma}$-ray irradiated EPR. As the radiation dose was increased, the peak temperature of the loss factor and tans of EPR were increased and loss factor and tan$\delta$ at peak temperature were decreased. Activation energies were calculated using loss factor and thermal decomposition for ${\gamma}$-ray irradiated EPR as well. The trends of both calculated activation energies showed the same tendencies as radiation dose was increased.

• ETRI Journal
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• 제27권4호
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• pp.449-452
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• 2005

The electrical characteristics of solid state devices such as the bipolar junction transistor (BJT), metal-oxide semiconductor field-effect transistor (MOSFET), and other active devices are altered by impinging photon radiation and temperature in the space environment. In this paper, the threshold voltage, the breakdown voltage, and the on-resistance for two kinds of MOSFETs (200 V and 100 V of $V_{DSS}$) are tested for ${\gamma}-irradiation$ and compared with the electrical specifications under the pre- and post-irradiation low dose rates of 4.97 and 9.55 rad/s as well as at a maximum total dose of 30 krad. In our experiment, the ${\gamma}-radiation$ facility using a low dose, available at Korea Atomic Energy Research Institute (KAERI), has been applied on two commercially available International Rectifier (IR) products, IRFP250 and IRF540.