• Korean Journal of Food Science and Technology
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• v.32 no.2
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• pp.271-276
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• 2000

Electron beam (EB) irradiation was compared with gamma ray (GR) in terms of their effects on physicochemical qualities of microbial-decontaminated red pepper powder. The pH and soluble solid of the samples were relatively constant when exposed to EB and GR up to 15 kGy, which also did not induce significant chances in total and reducing sugars. The water soluble pigment and capsanthin content of red pepper powder showed a decreasing tendency as the irradiation dose increased. However, the pungent components, capsaicin and dihydrocapsaicin were shown resistant to irradiation doses applied. Based upon the results, EB was similar to GR in its effect on the physicochemical attributes of the samples, and the irradiation doses required for microbial control were not detrimental to the quality attributes of red pepper powder.

• Proceedings of the Korea Information Processing Society Conference
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• 2014.04a
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• pp.811-814
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• 2014

일본 후쿠시마 제일 원자력발전소의 대지진/쓰나미에 이은 원자로 건물 수소폭발 사고의 수습 과정에서 사용후 핵연료 저장조에 보관되어 있는 핵연료의 안전문제가 대두되었다. 사용후 핵연료의 잔열 성분을 냉각시키고, 그리고 사용후 핵연료가 방출하는 고선량 방사선을 차폐시키기 위해서 일정 깊이 이상의 수조에 사용후 핵연료를 저장한다. 사용후 핵연료 저장조에 냉각수 공급이 중단되면, 사용후 핵연료의 고유 잔열에 의해 수조의 물이 증발하여 수위가 감소하게 된다. 계속해서 냉각수 공급이 되지 않으면, 사용후 핵연료의 잔열은 증가하게 되고, 수조의 물은 비등하여 증발은 가속화 된다. 사용후 핵연료 저장조의 수위가 고갈되면 고선량의 감마선이 방출된다. 수조의 수위가 정상적일 경우 사용후 핵연료 저장조의 공기중 감마선 선량율은 0.15mSv/h 이다. 수조의 수위가 사용후 핵연료 상부 꼭대기를 기준으로 2m, 1m, 및 0m (핵연료 노출) 로 감소하게 되면, 사용후 핵연료 저장조의 공기중 감마선 선량율은 500mSv/h, 50Sv/h, 및 5kSv/h 로, 급격히 증가한다. 본 논문에서는 사용후 핵연료 저장조 감시카메라의 관측 성능을 평가하기 위해, 고성능 칼라 CCD 카메라에 대해서 1 kGy/h 의 고선량율로 감마선 조사실험을 수행하였다. 이에 대한 실험결과를 기술한다.

• Journal of Radiation Protection and Research
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• v.13 no.2
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• pp.29-40
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• 1988

A spectrum-exposure rate conversion operator G(E) for a portable HPGe detector used for field environmental radiation survey was theoretically developed on the basis of a space distribution function of gamma flux emitted from a disk source and an areal efficiency of the detector. The radiation exposure rates measured using this G(E) and the portable HPGe. detector connected to a portable multichannel analyzer were compared with those measured by a 3' ${\phi}\;{\times}$3' NaI(Tl) scintillation detector with the reported G(E) and a pressurized ionization chamber. A comparison of the three results showed that the result obtained using the HPGe detector was lower than those determined using the NaI(Tl) detector and ionization chamber by 17% to 29%, The difference obtained is close to that reported in literature. The method developed here can be easily applicable to obtain a G(E) factor suitable to any detector for detecting the exposure rate of environmental gamma radiation, since the spectrum-exposure rate conversion operator can be calculated by a hand calculator.

• Journal of Radiation Protection and Research
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• v.2 no.1
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• pp.9-16
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• 1977

A simple method has been established for determining RaA, RaB and RaC concentrations in airborne dust. This is to evaluate the concentration from measurement of total alpha activities in three selected-time intervals after an air sample is taken from the membrane filter paper (mean pore size: $0.8{\mu}m$). As a preliminary trial, a time-variation of the concentrations has been determined using the single-filter method at the KAERI site (N. Lat. $37^{\circ}38'$ and E. Long $127^{\circ}15'$), Seoul, Korea. It appears that there is a large variation of the concentrations depending on the sampling time. Generally the highest value was observed in the morning that may coincide with the highest density of atmosphere in a day while the lowest value was obtained around fourteen o'clock.

• Journal of Radiation Industry
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• v.6 no.2
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• pp.111-117
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• 2012

This study was conducted to improve organoleptic quality of gamma-irradiated Tarakjuk at 10 kGy with cheeses (Camembert, Cheddar, Gouda, and Edam) and flavors (Nurungji, cream, and vanilla-cream). Overall acceptability of gamma-irradiated Tarakjuk added each camembert cheese and vanilla-cream flavor was the highest among the all samples. In the effect of sterilization method on the quality of Tarakjuk, the autoclaved samples added with Edam cheese, Gouda cheese, and vanilla-cream flavor, respectively, were showed higher score on the overall acceptability than the irradiated samples, meanwhile the irradiated samples were superior in the other samples. In case of added mixture of Edam cheese and vanilla-cream flavor, irradiated Tarakjuk with mixture was showed the most of high score on overall acceptability. In conclusion, addition of mixture of cheese and flavor to Tarakjuk may help to improve organoleptic quality of sterilized Tarakjuk by gammairradiation.

• Journal of Radiation Industry
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• v.6 no.2
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• pp.165-169
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• 2012

This study was conducted to determine the prevention effect of poly-gamma-glutamic acid (${\gamma}-PGA$) on tissue damage induced by gamma irradiation for development of xenograft. Porcine tendons were treated at various doses of ${\gamma}-PGA$ (0.1, 0.5, 1 and 5%) and then gamma-irradiated (30 kGy). Prevention effects on tissue damage were measured as the result of tensile strength, hydroxyproline contents and viscosity of ${\gamma}-PGA$. Tensile strength was remarkably decrease in gamma-irradiated porcine ligament, but increased by ${\gamma}-PGA$ treated one. Among the ${\gamma}-PGA$ treatment doses, 1% treated group showed the highest values of tensile strength compared to non-treated group. Hydroxyproline contents was significantly increased by gamma irradiation, but decreased by the ${\gamma}-PGA$ treatment. Particularly, 1 and 5% ${\gamma}-PGA$ treated group were exhibited lower values of hydroxyproline contents than other group. In the result of viscosity, gamma-irradiated ${\gamma}-PGA$ (1%) was remarkably increased. Base on the results, it demonstrated that gamma irradiation induces severe alteration of mechanical property and collagen contents on porcine ligament, but ${\gamma}-PGA$ can effectively prevent these tissue damage.

• Journal of Radiation Industry
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• v.11 no.1
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• pp.19-25
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• 2017

It is suggested that the dose limit recommended in the Enforcement Decree of Korea's Nuclear Safety Act should not exceed 150 mSv per year for radiation workers. Recently, however, ICRP 118 report has suggested that the threshold dose of the lens should be reduced to 0.2~0.5 Gy and the mean dose should not exceed 50 mSv per year for an average of 20 mSv over 5 years. Based on these contents, $^{123}I$, $^{99m}Tc$, and $^{18}F-FDG$, which are radioisotope drugs that are used directly by radiation workers in the nuclear medicine department in Korea are expected to receive a large dose of radiation in the lens in distribution and injection jobs to administer them to patients. The ED3 Active Extremity Dosimeter was used to measure the dose of the lens in the nuclear medicine and radiation workers and how much of the dose was received per 1 mCi.

• Journal of Radiation Industry
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• v.5 no.4
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• pp.359-364
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• 2011

This study was aimed to investigate the effect of oxidants on biodegradability and decomposition of acetaminophen (ACT) by gamma ray. Three kinds of chemical, potassium persulfate, hydrogen peroxide and ferrous sulfate were selected as an oxidant. The absorbed dose was ranged from 0.2 to 10 kGy and the concentration of oxidants was from 0.1 to 10 mM and the initial concentration of acetaminophen was $30mg\;l^{-1}$ in this study. The concentration of ACT was gradually decreased corresponding to the increase of the absorbed dose. However, mineralization of ACT was not occurred by the increased of the absorbed dose. When the 10 mM of oxidants applied to the ACT aqueous solution, the concentration of ACT was rapidly decreased according to absorbed dose and the mineralization was observed in potassium persulfate. Biodegradability of ACT with potassium persulfate was higher than that of ACT without potassium persulfate in lower absorbed dose and decreased according to higher absorbed dose.

• Journal of Radiation Industry
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• v.7 no.1
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• pp.1-5
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• 2013

Photostimulated luminescence (PSL) and thermoluminescence (TL) analyses were applied to identify the cookie molds mixed with 2 mg of 10 kGy-irradiated minerals according to cookie processing methods and sonication time (0~60 min) for mineral separation. PSL analysis showed that photon counts of cookies, dried or baked, ranged intermediate levels between the lower and upper threshold (700~5,000 counts/60 s), thereby showing its unsuitablility for screening of irradiated cookie. The TL glow curve intensities, measured according to mineral separation time (5, 10, 20, 40 and 60 mins) from the cookies using a sonicator, were high enough to identify irradiation status and significantly increased with the time in dried cookies. Those of baked cookies, however, were relatively low and not linearly increased with the time, but still possible to identify them (p<0.05).

• Journal of Radiation Industry
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• v.5 no.4
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• pp.347-352
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• 2011

In order to identify the genetic relationship analysis by acute and chronic gamma irradiation, Arabidopsis (Arabidopsis thaliana L.) were irradiated with 200 Gy of gamma-rays using gamma-irradiator (3,000 Ci; Nordion, Canada) and gamma-phytotron (400 Ci; Nordion, Canada) for acute and chronic irradiation, respectively. Genetic relationship among two acute gamma-irradiated plants (A1 and A24) and three chronic gamma-irradiated plants (C1W, C2W, C3W) were analyzed using the amplified fragment length polymorphism (AFLP) technique compared with each non-irradiated plant. A total of 28 EcoRI and MseI primer combinations were used to screen 8 treatments by the ABI3130 capillary electrophoresis system. Amplified products by 28 primer sets showed 1,679 bands with an average of 51 bands per primer combination. Out of the total bands scored, 1,164 fragments were polymorphic bands, with different alleles existing among the treatments. The cluster analysis was performed using the UPGMA (Unweighted Pair Group Method using Arithmetic) in the computer program NTSYS-pc. In clustery analysis, acute gamma-irradiation showed higher genetic variation compared with chronic gamma-irradiation.