• Journal of Applied Tourism Food and Beverage Management and Research
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• v.13 no.2
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• pp.1-10
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• 2002

This research was conducted to investigate changes in quality characteristics of gamma-irradiated chickens during storage at different temperature and periods. The proximate composition of Chicken was not significantly changed by irradiation dose and storage period. No significant difference in the components of fatty acids we were observed by gamma irradiation. In general, the amount of released free amino acid was increased during storage and was not significantly changed by gamma irradiation.

• Journal of Radiation Protection and Research
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• v.16 no.2
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• pp.7-16
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• 1991

Measurement of Co-60 gamma rays has been made for establishment of exposure standard and analyze it's overall uncertainties. Exposure rate determined by the charge mode method using vibrating reed amplifier with cylinderical type cavity chamber. The values of a variety of physical constants and the correction factors are evaluated. The resulting exposure rate is 690.81 R/h at the distance of 1m from the source and the related uncertainties is ${\pm}0.8%$

• Proceedings of the Korean Environmental Sciences Society Conference
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• 2001.05a
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• pp.129-132
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• 2001

감마선 조사에 의한 TCE와 PCE의 분해에 있어서, TCE는 과산화수의 영향을 거의 받지 않았지만, PCE는 과산화수소의 농도증가에 따라 분해가 감소되었다. 이들의 원인을 밝혀내기 위해 과산화수소의 첨가에 따른 $\cdot$OH의 생성량 변화를 EPR/spin-trapping의 방법에 의해 확인한 결과, EPR의 DMPO-OH의 신호강도 조사에서 과산화수소를 첨가한 경우와 첨가하지 않은 경우 모두 차이가 거의 없었다. 따라서 감마선 조사에 과산화수소를 별도로 첨가해도 $\cdot$OH의 생성량 증가가 없는 것으로 보아, 방사선에 의한 TCE 분해에 있어 과산화수소의 첨가는 큰 영향을 주지 않는다는 것을 밝힐 수 있었다. 그러나 PCE의 경우는 향우 계속 연구될 예정이다.

• Proceedings of the Korean Nuclear Society Conference
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• 1997.05b
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• pp.350-355
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• 1997

가압중수로(PHWR)형 원자력발전소의 저장수조에 보관중인 사용후핵연료를 대상으로 하는 핵물질 보장조치(safeguards) 이행에 필요한 핵연료다발 수중검증장치를 개발하였다. 본 장치는 CdTe 감마선검출기, 차폐체 및 시준기등으로 구성된 검출부와 이를 지지 및 구동하기 위한 구동부로 구성되어 있다. 검출부에 대하여 감마선 표준선원 및 사용후핵연료 시료를 사용하여 성능시험을 수행한 결과 현장검증시의 요건을 만족하였고, 구동부의 경우 건식조(dry pit)에서 수행한 예비실험 결과 검증목적에 적합하였다. 따라서, PHWR형 원자력발전소인 월성 1 호기의 수중저장조에 있는 사용후CANDU핵연료에 대한 현장성능시험을 현재 준비중에 있으며 그 결과를 바탕으로 하여 국가사찰시에 본 장치를 사용할 예정이며, 향후 IAEA의 공인을 획득하여 IAEA 사찰용 장비로도 활용할 계획이다.

• Nuclear Engineering and Technology
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• v.14 no.2
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• pp.64-69
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• 1982

Directional correlation measurements for the Co-60 and Cs-134 cascade gamma-rays have been performed in the angular range from 90$^{\circ}$ to 180$^{\circ}$ by use of the fast coincidence scintillation spectrometer incorporated with a gamma-ray polarimeter based on the Compton scattering effect to determine the polarization correlations. The experimental method together with the theoretical background is described, and the results are shown graphically to represent the consistency of the measurement with approximate theoretical estimates.

• Food Science of Animal Resources
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• v.30 no.1
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• pp.124-132
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• 2010

This study evaluated the effects of gamma ray and electron beam (E-beam) to improve the safety of spices for meat processing. The spices (garlic powder, curry powder, turmeric powder, black pepper, white pepper, oregano, parsley, laurel leaf powder, basil, and rosemary) were irradiated by gamma ray and E-beam at 0, 2, 4, 6, 8, and 10 kGy. Total bacterial populations were then enumerated on total plate count agar, and bacteria isolated from the samples were identified by polymerase chain reaction (PCR). In addition, $D_{10}$ values for Bacillus cereus and Staphylococcus aureus inoculated in spices was determined, and the Ames test was conducted for genotoxicity analysis. The contaminated total bacterial populations in spices ranged from 1.5 to 3.8 Log CFU/g, and most of identified bacteria were Bacillus spp., and Staphylococcus spp. However, the bacterial populations decreased below the detection limit (2 Log CFU/g) after irradiation at 4 kGy except for parsley, which required 6 kGy in gamma ray and 8 kGy in E-beam to decrease total bacterial populations below detection limit. $D_{10}$ values were also higher (p<0.05) in E-beam treated samples than gamma-ray treated samples. No genotoxicity was observed in both conditions with and without metabolic activation. These results indicate that gamma ray (>4 kGy and <6 kGy) could be more useful to improve food safety of meat processing spices compared to E-beam.

• Journal of Sensor Science and Technology
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• v.9 no.4
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• pp.274-280
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• 2000

This paper deals with an experimental study to apply commercial semiconductors to measure radiation dose rate for gamma ray. Since the low cost, small size, high efficiency and ruggedness of silicon photodiodes make them attractive photodetectors, they coulde be effectively used in measuring any radiation such as gamma ray. Most PN photodiodes show that the reverse current increases when the light is increased. Therefore the depletion region of them have influence on the reverse current, so we choose silicon PIN photodiodes with large depletion region. In order to detect radiation dose rate and then, to apply in developing any gamma ray dosimeter, some examinations and experiments were performed to PIN photodiodes in this work. Two kinds of PIN photodiodes, such as NEC's PH302 and SIEMENS's BPW34, were tested in a Co-60 gamma irradiation facility with a semiconductor parameter analyzer. As a result, we found that such PIN photodiodes present good linearity in diode current characteristics with dose rate. Therefore silicon PIN photodiodes could be suitably used in designing gamma ray dosimeters.

• Journal of Advanced Navigation Technology
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• v.20 no.6
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• pp.612-616
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• 2016

Gamma-ray must be detected and processed immedietely after generation of it in the circumstances where it exists. Software methology may be used to process randomly generated signals, but its memory size and processing time become large. By the way, the hardware circuit to detect randomly generated signals is generalized in industrial site, while those circuits are not able to answer to the cases whose amplitude are very small and also speed high. We researched and developed hardware based peak-hold circuit that is able to detect peaks of gamma-ray signals through direct reading out their values by ADC at the time of maximum reaching for the small amplitude and high speed signals, and proposed and estimated its results in this paper. This peak-hold circuit is adequate to use in the radiation circumstances in which the gamma-rays are heavy because its circuit can catch high speed signals efficiently without software signal processing supports.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.21 no.1
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• pp.223-228
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• 2017

In this paper, we are proposing an optimal design of wideband pulsed type gamma-ray sensors. These sensors were manufactured based on the design results and after word electrical properties were analyzed. The sensor input parameters were derived on the basis of pulsed gamma-ray spectrum and time-dependent energy rate, and the output current which were derived on the basis of the sensor sensitivity control circuit. Pulsed gamma-ray sensors were designed using the TCAD simulators. The design results show that the optimal Epi layer thickness is 45um with the applied voltage 3.3V and the diameter is 2.0mm. The doping concentrations are as follows : N-type is an Arsenic as $1{\times}10^{19}/cm^3$, P-type is a Boron as $1{\times}10^{19}/cm^3$ and Epi layer is Phosphorus as $3.4{\times}10^{12}/cm^3$. The fabricated sensor was a leakage current, 12pA at voltage -3.3V and fully depleted mode at voltage -5V. A test result of pulsed radiation shows that the sensor gives out the optimal photocurrent.

• Journal of the East Asian Society of Dietary Life
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• v.8 no.4
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• pp.430-440
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• 1998

Meat is a perishable product since it offers favorable conditions for microbial contamination and multiplication. Besides, undercooked and raw meat has been linked to outbreaks of hemorrhagic diarrhea due to the presence of microbial pathogens. Therefore, this study was conducted to find out the effect of the use of gamma-irradiation in order to improve preservation and eliminate this microorganisms. The Initial level of microbial contamination in pork was 1.1$\times$10$^3$ CFU/g (aerobic bacteria), 5.3$\times$10$^3$CFU/g (psychrophile), 3.1$\times$10$^3$ CFU/g (coliforms) and 3.2$\times$10$^3$ CFU/g(Listeria), All kinds of contaminated microorgnisms were sterilized by gamma irradiation at 3 kGy. The proximate composition of pork was not significantly changed by irradiation dose and storage period. The pH was slightly increased during storage period and titratable acidity decreased. However, no significant changes in pH and acidity were observed by gamma irradiation. There was no difference in total amino acid content regardless of irradiation dose and storage period. Glutamic acid was detected at high levels throughout the storage period. The major mineral compositions of pork were potassium, phosphorus, sodium, magnesium. No significant difference in the components of minerals were observed by gamma irradiation.