• 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.

• KSBB Journal
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• 제27권3호
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• pp.195-198
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• 2012

This study was carried out to assess the effect of radiation on the changes of Hizikia fusiformis cooking juice ethanol extract and to compare the effect of gamma ray and electron beam. On the applying radiation, the dark color of cooking juice became changed with higher brightness and lower redness and yellowness. But, there was no difference between gamma ray radiation and electron beam radiation. 1,1-Diphenyl-2-picryl-hydrazyl radical scavenging activity and tyrosinase inhibitory activity of cooking juice were shown to be increased by radiation independent on the radiation source types. The reason for the increased biological activities was caused by higher content of total phenolic compounds. The results could be applied to investigate the effect of radiation source on the color and antioxidant activity of biomaterials, and it was thought that irradiation could be an promising method for enhancing the biological activity of biomaterials.

• 방사선산업학회지
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• 제5권2호
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• pp.125-130
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• 2011

The purpose of this study was to evaluate the protective effect of the Perilla frutescens cv. Chookyoupjaso mutant water extract (PFWE) on gamma ray-induced oxidative stress in mice. Gamma-ray is one of the sources for inducing oxidative stress. The study was divided into 6 groups with 6 mice for each treatment. Groups I and II were treated with saline (vehicle) only, groups III, IV, V, and VI were pretreated with PFWE 10, 20, 50, $50mg\;kg^{-1}$ respectively for 2 weeks before gamma radiation. And then groups II, III, IV, V were irradiated. We found that the activities of aspartate transaminase (AST) and alanine transaminase (ALT) were increased and the activities of antioxidant enzymes such as superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), and glutathione reductase (GR) were decreased by irradiation in mice. However, treatment of PFWE attenuated the activities of AST and ALT in a dose-dependent manner in irradiated mice. Furthermore, treatment of PFWE significantly increased the activities of SOD, GPx, and GR in a dose-dependent manner in irradiated mice, except for the CAT. Interestingly, the activities of GPx and GR were significantly increased by PFWE treatment. Taken together, PFWE could be effective in protecting on gamma ray-induced oxidative stress in mice.

• 전기학회논문지
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• 제58권7호
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• pp.1450-1455
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• 2009

Assumed that an IPTV camera system is to be used as an ad-hoc sensor for the surveillance and diagnostics of safety-critical equipments installed in the in-containment building of the nuclear power plant, an major problem is the presence of high dose-rate gamma irradiation fields inside the one. In order to uses an IPTV camera in such intense gamma radiation environment of the in-containment building, the radiation-weakened devices including a CCD imaging sensor, FPGA, ASIC and microprocessors are to be properly shielded from high dose-rate gamma radiation using the high-density material, lead or tungsten. But the passive elements such as mirror, lens and window, which are placed in the optical path of the CCD imaging sensor, are exposed to a high dose-rate gamma ray source directly. So, the gamma-ray irradiation characteristics of the passive elements, is needed to test. A CCD camera lens, made of glass material, have been gamma irradiated at the dose rate of 4.2 kGy/h during an hour up to a total dose of 4 kGy. The radiation induced color-center in the glass lens is observed. The degradation performance of the gamma irradiated lens is explained using an color component analysis.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2004년도 하계학술대회 논문집 Vol.5 No.1
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• pp.437-440
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• 2004

The radiation-induced changes taking place in poly(vinylidene fluoride)(PVDF) exposed to $^{60}Co\;\gamma-ray$ irradiation were investigated in correlation with the applied doses. Samples were irradiated in air at room temperature by $^{60}Co\;\gamma-ray$ to doses in the range of 200 to 1000 kGy. Various properties of the irradiated PVDF were studied using nm, differential scanning calorimetry(DSC) and gel fraction. $^{60}Co\;\gamma-ray$ irradiation was found to induce changes in chemical, thermal, structural properties of PVDF and such changes vary depending on the radiation dose.

• Journal of Astronomy and Space Sciences
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• 제31권4호
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• pp.317-323
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• 2014

Odyssey, one of the NASA's Mars exploration program and SELENE (Kaguya), a Japanese lunar orbiting spacecraft have a payload of Gamma-Ray Spectrometer (GRS) for analyzing radioactive chemical elements of the atmosphere and the surface. In these days, gamma-ray spectroscopy with a High-Purity Germanium (HPGe) detector has been widely used for the activity measurements of natural radionuclides contained in the soil of the Earth. The energy spectra obtained by the HPGe detectors have been generally analyzed by means of the Window Analysis (WA) method. In this method, activity concentrations are determined by using the net counts of energy window around individual peaks. Meanwhile, an alternative method, the so-called Full Spectrum Analysis (FSA) method uses count numbers not only from full-absorption peaks but from the contributions of Compton scattering due to gamma-rays. Consequently, while it takes a substantial time to obtain a statistically significant result in the WA method, the FSA method requires a much shorter time to reach the same level of the statistical significance. This study shows the validation results of FSA method. We have compared the concentration of radioactivity of $^{40}K$, $^{232}Th$ and $^{238}U$ in the soil measured by the WA method and the FSA method, respectively. The gamma-ray spectrum of reference materials (RGU and RGTh, KCl) and soil samples were measured by the 120% HPGe detector with cosmic muon veto detector. According to the comparison result of activity concentrations between the FSA and the WA, we could conclude that FSA method is validated against the WA method. This study implies that the FSA method can be used in a harsh measurement environment, such as the gamma-ray measurement in the Moon, in which the level of statistical significance is usually required in a much shorter data acquisition time than the WA method.

• 방사선산업학회지
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• 제6권3호
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• pp.231-237
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• 2012

This paper introduces a gamma-ray measurement system for a transportable tomography which is applicable for an industrial process diagnosis. The gamma-ray measurement system consists of pulse mode operating 72 channel CsI detectors, main AMP-pulse shaper, single channel analyzer, counter and control PC. The CsI crystal is coupled with a PIN diode which is connected to an amplifier and pulse shaper. For a compact design, the amplifier and pulse shaping circuit are included in a single package. 36 sets of CsI detectors are connected to a multi-channel counter through single channel analyzers. A computer controls and collects data from two multi-channel counters. This configuration results in 72 channel counting system in total. The CT rotator and radiation measurement system are controlled by a PC with LabVIEW program. Tomographic data were measured for a phantom by the measurement system and transportable gamma-ray CT. From the experimental data image reconstructions were performed by ML-EM algorithm. The result showed that the CsI detector system can be a suitable component for transportable gamma-ray CT system.

• 전기의세계
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• 제22권4호
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• pp.7-10
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• 1973

The characteristics of all the instruments and materials used in atomic industry is changed due to radiation damages by the effects of radiation activities. In this study, when the Carbon Resistor, main element of electrical circuits, is irradiated by Gamma-Ray, variations in its electrical properties have been investigated. The following results are obtained: 1) The resistance value in Carbon Resistor is exponentially increased as the quantity of irradiation by Gamma-Ray is increased, but in case of more than 10$^{6}$ R/hr. of quantity of irradiation it has saturated-state value. 2) The rate of change inrestistance value has been independent on the intensity of Gamma-Ray source when Carbon Resistor is irradiated in the same quantity of irradiation. 3) The resistance value in irradiated Carbon Resistor has not been varied with elapse of time. 4) The more the distance from the Carbon Resistor to the Gamma-Ray source the more greatly the resistance value is decreased and that it has been shown that the more quantity of irradiation by Gamma-Ray, the greater the rate of decrease in resistance value. Through the above results it has been concluded that the measurement values obtained by the high-precision instruments in the radiation field have to be corrected with proper consideration to radiation damages.

• Journal of Applied Biological Chemistry
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• 제55권1호
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• pp.1-5
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• 2012

Recently, we reported that Jeju ground water contains vanadium components and exerts antioxidant effects in vitro and in vivo via the scavenging of reactive oxygen species and enhancement of antioxidant enzyme activities. In the present study, the antioxidant actions of Jeju ground water were compared with those of tap water against gamma-ray radiation in mice. C57BL/6 mice were irradiated with gamma-ray at a dose rate of 2 Gy. The mice were then given tap water or Jeju ground water for 90 days. Jeju ground water compared with tap water enhanced the activities and levels of superoxide dismutase, catalase, and glutathione peroxidase in irradiated liver tissues. Jeju ground water also enhanced the levels of intracellular reduced glutathione, which is vital for normal liver function and repair. These results suggest that vanadium-containing Jeju ground water can safeguard against the harmful actions of gamma-ray radiation through the support of hepatic antioxidant processes.

• 천문학회보
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• 제36권1호
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• pp.48.1-48.1
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• 2011

We utilize the jitter radiation, which is the emission of relativistic electrons in the random and small-scale magnetic field, to investigate the high-energy emissions of gamma-ray bursts (GRBs). Under the turbulent scenario, the random and small-scale magnetic field is determined by the turbulence. We also estimate the acceleration and cooling timescales. We identify that some GRBs are possible cosmic-ray sources.