• Journal of Radiation Industry
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• v.5 no.3
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• pp.253-258
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• 2011

Acetylsalicylic acid (ASA) has been issued recently in contaminated water environments because of potential impacts on ecosystem and public health. This study was aimed at investigating the possibility of ASA degradation using gamma ray irradiation. In addition, the use of sodium persulfate, hydrogen peroxide, ferrous sulfate were tested in order to examine a synergistic effect with gamma ray. The absorbed dose was ranged from 0.2 to 10 kGy and the concentration of oxidants were from 0.1 to 10 mM in this study. The concentration of ASA was gradually decreased corresponding to the increase of the absorbed dose. When soudium persulfate was simultaneously applied, most of the parent compound was completely degraded even at a low dose of 0.8 kGy. The removal efficiency of total organic carbon was 90% even at the highest dose of 10 kGy without sodium persulfate. However, the efficiency was dramatically enhanced up to 98% at the same dose by adding 10 mM of oxidants. It was suggested that hydroxyl radical ($OH{\cdot}$) and sulfate radical ($SO{_4}^-{\cdot}$) were formed in the system and made roles in degrading ASA at the same time.

• Journal of Radiation Industry
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• v.6 no.3
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• pp.211-215
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• 2012

In this study, crosslinked polyethylene (PE) foam sheets were prepared through gamma-ray irradiation. PE foam sheets were prepared through a foaming process using sodium bicarbonate as a blowing and foaming agent. The prepared PE foam sheets were then crosslinked through gamma-ray irradiation. The crosslinking degree was increased to 86.0% with an increase in the absorption dose. The tensile strength of the crosslinked PE foam sheets was increased with an increase in the absorption dose. However, the elongation-at-break of the crosslinked PE foam sheets was decreased. The thermal decomposition temperature of the crosslinked PE foam sheets was increased to $421.2^{\circ}C$ with an increase in the absorption dose. The SEM analysis revealed that the morphology was not changed significantly after the crosslinking through gamma-ray irradiation.

• Journal of Radiation Protection and Research
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• v.26 no.3
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• pp.287-290
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• 2001

The 9.17MeV gamma-rays from the $^{13}C(p,\;{\gamma})^{14}N,\;^{14}N({\gamma},\;{\gamma})^{14}N$ reactions were measured. The incident 9.17MeV gamma-ray was produced from the $^{13}C(p,\;{\gamma})^{14}N$ reaction at Ep=1.75MeV resonance. The 1.75MeV proton beam was accelerated using the 3MV SNU-AMS Tandetron and 1.7MV KIGAM Tandem accelerators. The enriched 13C target was $121{\mu}g/cm^2$ self-supporting foil, and we used liquid nitrogen as a resonant absorption target. We used a HP-Ge detector with 30% efficiency and less 2keV energy resolution. We developed new method to detect the scattered 9.17MeV gamma-ray from the nitrogen target by using the energy difference between the Doppler shifted gamma-ray from the $^{13}C(p,\;{\gamma})^{14}N$ reaction and the resonant absorbed and rescattered gamma-ray from the $^{14}N({\gamma},\;{\gamma})^{14}N$ reaction.

• Korean Journal of Environmental Agriculture
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• v.19 no.5
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• pp.394-400
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• 2000

${\gamma}-Radiation$ at very low doses frequently has a stimulating or hormetic effect on the growth of organism. Effects of low dose ${\gamma}-ray$ irradiation on the root growth of soybean cultivars were investigated and hormetic effects by environmental conditions were compared with the occurrence of increased economic yield, seeds of cultivars were irradiated with the dose of $0.5{\sim}20Gy$ and cultivated in growth chamber controling temperature, humidity, light, greenhouse and field respectively. To understand hormetic effect on root growth of cultivars and the difference of hormetic effect by cultivation environment, harvested root of soybean cultivars were scanned with image file, and root surface area, root length, root average diameter etc. were examined by WinRhizo program. Also, dry weight of cultivars was examined. Root growth and dry weight of soybean cultivars showed apparently hormetic effect at cultivation of growth chamber condition. In field experiment executed for whole life cycle, yields of pea were not different significantly in each ${\gamma}-ray$ irradiated cultivars but weight of one hundred peas increased in whole ${\gamma}-ray$ irradiated cultivars. Increment of yield was assumed to be induced through shortening of maturing stage caused by ${\gamma}-ray$ hormesis in early growth stage.

• Korean Journal of Veterinary Research
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• v.55 no.1
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• pp.21-30
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• 2015

The immune system is specifically sensitive to oxidative stress induced by ionizing radiation because of its rapid proliferative activity. For this reason, an instructive immune system is one of the best ways to minimize side effects, such immunodeficiency, of gamma radiation. Over the past few decades, several natural plants with antioxidant and immunomodulatory properties have been identified as adjuncts for nontoxic and successful radiotherapy. Hizikia fusiforme extract (HFE) containing plentiful dietary fiber and fucoidan is known for its instructive antioxidant capacity, immunomodulation abilities, and immune activation. In this study, we determined whether HFE protects radiosensitive immune cells from gamma radiation-induced damage. C57BL/6 mice were irradiated with gamma-ray. The effect of HFE on the ionizing radiation damage of immune cells was then evaluated with an MTT assay, 3H-thymidine incorporation assay, and PI staining. We found that HFE stimulated the proliferation of gamma-ray irradiated immune cells without cytotoxic effects. We also observed that HFE not only decreased DNA damage but also reduced gamma radiation-induced apoptosis of the immune cells. Our results suggest that HFE can protect immune cells from gamma-ray damage and may serve as an effective, non-toxic radioprotective agent.

• Polymer(Korea)
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• v.30 no.1
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• pp.10-13
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• 2006

The effects of antioxidants and thermal treatment on the radiation resistance of the gamma-ray irradiated polypropylene (PP) were studied. The PP was blended with various antioxidants and was fabricated into a sheet. The PP sheet was irradiated with gamma-ray to a dosage of 25kGy in the nitrogen atmosphere. The differences in both color and mechanical strength were investigated for the gamma-ray irradiated PP depending on the kind and the content of antioxidant. The residual amount of free radical and the variation of oxidation index were investigated for the gramma-ray irradiated PP with thermal treatment after irradiation. The PP having phosphite antioxidant showed little difference in color after gamma-ray irradiation compared with the PP having phenolic or mine antioxidant. Sufficient amount of free radical could be removed from the gamma-ray irradiated PP by the thermal treatment at $130\;^{\circ}C$ for 30 min. Thermally treated PP showed lower oxidation index than the PP without thermal treatment.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2016.10a
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• pp.942-943
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• 2016

Stereo gamma ray detection system generates a two-dimensional image of the gamma ray by using the position values and the gamma ray signal. And the device will overlap with the visible light image shows the actual distribution of the gamma-ray space. The gamma ray detection device is a stereo configuration to a motion controller for controlling the signal measurement unit and the position detection portion for detecting the detection portion and the gamma-ray signal comprising a gamma-ray detection sensor. In this paper, we developed a system operation management algorithm for each module individually configured efficiently. We confirmed the imaged and distribution information output for the gamma rays from gamma-ray irradiation test site by using these results.

• Journal of Radiation Industry
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• v.8 no.2
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• pp.105-109
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• 2014

This study was conducted to investigate the sensitivity of Arthrobacter sp. PAMC 25486 to various mutagens. ${\gamma}-ray$, UV-ray, Ethyl methane sulfonate (EMS) and hydrogen peroxide ($H_2O_2$) were used as mutagen, and the survival rate of Arthrobacter sp. was measured at various doses of ${\gamma}-ray$ and UV-ray, and concentrations of EMS and $H_2O_2$. Decimal reduction dose ($D_{10}$ value) of Arthrobacter sp. was determined 370 Gy for a gamma irradiation treatment, 0.019 J for a UV ray, 2.5 mM for EMS, and 230 mM for $H_2O_2$. This result will be applied for the development of superior mutant strain of Arctic bacteria producing valuable compounds.

• The Journal of the Korean Society for Microbiology
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• v.8 no.1
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• pp.37-42
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• 1973

For the preparation of non-infective vaccine against typhoid fever, the authors had carried out an investigation on the possibilities of using $^{60}Co\;{\gamma}$-ray irradiation for the inactivation of Salmonella typhi Ty 2. The following results were obtained. 1) Chicks shortly after hatching were higher susceptible than mice to intracerebral injection with S. typhi. 2) In safety test on experimental animal, $^{60}Co\;{\gamma}$-ray irradiated vaccines demonstrated no clinical symptom while the phenol treated vaccines revealed several cases of narcosis by intraperitoneal injection in chicks. 3) The rabbit antisera immunized with $^{60}Co\;{\gamma}$-ray irradiated and phenol treated vaccine revealed almost same agglutinin titers to each other. 4) In potency test in chicks, there was no significance in the protective capacity between $^{60}Co\;{\gamma}$-ray irradiated and phenol treated vaccines.

• Journal of the Institute of Electronics and Information Engineers
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• v.52 no.4
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• pp.197-203
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• 2015

Nuclear power plant has increased continuously for power production in all over the world and the interest about nuclear accident and the dismantling of aging nuclear power plant has been a growing. The leaked radioactive source that is generated by radiation accidents must detect and remove to minimized the damage as soon as possible. Gamma-ray detection system that have been developed until now cannot provide the precise position of radioactive sources because they detect and imaging the position of radiation sources in just two dimensions. In this paper, stereo gamma ray detection system has developed and the algorithm for calculation of the distance has implemented to be able to measure the distribution of the leakage gamma ray source for the system. Stereo camera calibration for distance detection was conducted with the correction pattern and LED light and we carried out performance test of the system for the LED light source and a gamma ray source. In both experiments the results of the performance test, it was confirmed to have a 5% error. The results of this paper is used as a material for the development of gamma-ray imaging device.