• Food Science and Biotechnology
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• 제15권3호
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• pp.341-346
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• 2006

This study was performed to examine the effects of ${\gamma}$-irradiation on the volatile flavor compounds of dried leeks (Alliums tuberosum R.). Volatile compounds of dried leeks were extracted using simultaneous steam distillation and extraction (SDE), and analyzed by gas chromatography/mass spectrometry (GC/MS). Forty-one, 51, 45, and 42 compounds were tentatively identified in control, 1, 3, and 10 kGy irradiated samples, respectively. The constituents of flavor compounds in irradiated dried leeks were similar to non-irradiated samples. However, the intensities of the peaks were clearly different between them. Sulfur-containing compounds were detected as dominant compounds in all samples and their amounts decreased after ${\gamma}$-irradiation. ${\gamma}$-Irradiation reduced the total concentration of volatile compounds from leeks by 23.19, 15.09, and 30.23% at 1, 3, and 10 kGy doses, respectively.

• Journal of Radiation Protection and Research
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• 제10권2호
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• pp.96-108
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• 1985

감마선분광분석 및 열형광선량측정법에 의한 자연환경방사선의 선량해석에 관한 연구를 1984년 10월부터 약 1년간에 걸쳐 충남대학교 대덕캠퍼스내의 1만 $m^2$ 규모의 평면개활지에서 수행하였다. 이 연구에서 사용한 검출기는 3'${\phi}{\times}$3' NaI(T1) 섬광계수기(閃光計數器)와 plastic 에 밀봉하여 금속판에 압착 처리한 chip 과 Teflon-disk 로된 2종의 LiF TLD 였다. 실측실험으로는 3회에 걸친 24시간 cycle의 in-situ spectrometry 와 2회의 3개월 cycle 과 1회의 1개월 cycle에 걸친 TLD field dosimetry를 수행하였다. 측정한 모든 spectrum은 G(E)연산자법에 의하여 조사선량율(照射線量率)로 환산하였고 그 결과로부터 환경 방사선의 지설성분(地設成分)을 산출하였다. 결과(結果)에 의하면 spectrometry로 구한 조사선량율이 평균 $(10.54{\pm}2.96){\mu}R/hr$, TLD chip으로 측정해석한 값은 $(12.0{\pm}3.4){\mu}R/hr$, disk에서 얻은 값이 $(11.0{\pm}3.6){\mu}R/hr$로 오차범위 안에서 매우 좋은 일치를 보이고 있다. 그러나 감마선분광분석에 의한 자연방사선의 일변화(日變化)에는 가끔 심한동요가 관측되었다. 정확한 환경방사선량해석을 위하여 감마선분광분석과 TLD의 적절한 동시 배합사용이 바람직 하며, 보다 고감도의 TLD에 관한 연구와 국제비교등을 통한 선량평가의 정도향상(精度向上)을 위한 보다 깊이 있는 연구가 필요하다는 결론(結論)에 도달하였다.

• 방사선산업학회지
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• 제8권1호
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• pp.17-22
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• 2014

In this study, we prepared CdTe/CdS solar cells using a thermal vacuum evaporation method. In particular, $CdCl_2$ treatment was attempted using this same method at $400^{\circ}C$ for 30 min. The prepared CdTe/CdS solar cells were investigated using Fouier transform infrared spectrometry (FTIR), field emission scanning electron microscopy (FE-SEM), and a solar simulator system including light absorption properties, morphological properties, and power conversion efficiency (PCE). In addition, we investigated the gamma-irradiation treatment at dose rates of 0 Gy, 500 Gy, 1 kGy, 10 kGy, and 30 kGy. The characteristics of gamma-irradiation treatment were studied based on the same method described above. In particular, it showed increased values as 0.826% higher than the non-irradiation of 0.448% from PCE analysis.

• Nuclear Engineering and Technology
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• 제54권12호
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• pp.4715-4721
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• 2022

A comprehensive approach for modeling the pulse height spectra of gamma-ray detectors from passing radioactive cloud in a case of accident at NPP has been developed. It involves modeling the transport of radionuclides in the atmosphere using Lagrangian stochastic model, WRF meteorological processor with an ARW core and GFS data to obtain spatial distribution of radionuclides in the air at a given moment of time. Applying representation of the cloud as superposition of elementary sources of gamma radiation the pulse height spectra are calculated based on data on flux density from point isotropic sources and detector response function. The proposed approach allows us to obtain time-dependent spectra for any complex radionuclide composition of the release. The results of modeling the pulse height spectra of the scintillator detector NaI(Tl) Ø63×63 mm for a hypothetical severe accident at a NPP are presented.

• 한국지하수토양환경학회지:지하수토양환경
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• 제18권1호
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• pp.112-122
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• 2013

Current status of soil contamination with fluorine and its source were investigated. The basic principles and procedures of various techniques for the analysis of fluorine contents in soil and solid phase samples were summarized in this review. Analysis of fluorine in solid matrices can be achieved by two types of techniques: (i) UV/Vis spectrophotometer or ion selective electrode (ISE) analysis after performing appropriate extraction steps and (ii) direct solid analysis. As the former cases, the standard method of Korean ministry of environment, alkali fusion-ISE method, pyrohydrolysis, oxygen bomb combustion, aqua regia digestion-automatic analysis, and sequential extraction-ISE method were introduced. In addition, direct analysis methods (i.e., X-ray fluorescence spectrometry and proton induced gamma-ray emission spectrometry) and atomic spectrometry combining with the equipment for introducing solid phase sample were also reviewed. Fluorine analysis techniques can be reasonably selected through site-specific information such as matrix condition, contamination level, the amount of samples and the principles of various methods for the analysis of fluorine presented in this review.

• 한국약용작물학회지
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• 제5권2호
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• pp.113-118
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• 1997

미강에 함유된 약리성분인 ${\gamma}-oryzanol$ 함량을 검정하여 용도 다양화 연구의 기초 자료를 제공코자 시험을 수행한 바 다음과 같은 결과를 얻었다. Soxhlet 추출장치에서 얻은 미강유에서 유리 sterol과 ferulic acid ester가 분리되었다. 유리 sterol은 GC-MS에 의하여 campesterol, ${\beta}-sitosterol$ 및 stigmasterol로 구성되어 있음을 알 수 있었다. ferulic acid ester는 알칼리 가수분해에 의하여 얻어지는 검화분해물을 분리용 TLC로 분리하여 triterpene과 sterol을 얻었다. sterol은 GC-MS 측정으로 유리 sterol과 같은 조성임을 알았으며 triterpene은 cycloartanol, cycloartenol, 24-methylenecycloartanol 및 미지의 triterpene로 구성되었다. 미강유나 pitch 중 ferulic acid ester의 흡광도를 기준으로 ${\gamma}-oryzanol$의 함량을 평가한다면 큰 오차는 없으리라 생각된다.

• 한국식품과학회지
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• 제43권5호
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• pp.553-557
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• 2011

마늘의 천연 성분을 분석하였을 때 8개의 주요 성분이 나타났으며, 가장 크게 나타난 피크는 알린이었고 실제로 함량도 가장 높게 나타났다. 이소알린은 알린의 뒤를 이어 큰 피크를 나타내었고 함량도 알린에 이어 많은 양이 얻어졌다. 기타 마늘 특유의 함황유기화합물로서 ${\gamma}$-glutamyl peptide류가 있으며 함량이 충분하여 분리 정제를 수행한 것으로는 ${\gamma}$-glutamyl-S-allylcysteine, ${\gamma}$-glutamyl-S-1-propenylcysteine, ${\gamma}$-glutamylphenylalanine 등 3가지였다. 기타 마늘 특유의 성분은 아니지만 UV 208 nm에서 흡광도를 크게 나타내는 것으로 arginine, tyrosine, phenylalanine, tryptophan과 같은 일반적인 아미노산류가 있었지만, 본 연구에서는 마늘 특유의 아미노산과 펩타이드만을 정제하였다. 마늘 특이 아미노산과 펩타이드의 분리정제는 재순환 분취 HPLC를 이용하여 순수하게 정제하였으며, 생마늘 6 kg으로부터 알린, 이소알린, ${\gamma}$-glutamyl-S-allylcysteine, ${\gamma}$-glutamyl-S-1-propenylcysteine, ${\gamma}$-glutamylphenylalanine이 각각 7.32, 1.53, 0.38, 0.42, 0.23 g을 얻었으며 이를 마늘 함유량 대비 수율로 계산하면 각각 12.2, 42.5, 1.6, 1.2, 4.8%이었다. 정제한 물질들의 동정방법은 HPLC 머무름 시간의 비교 및 LC/MS를 이용한 분자량 측정이었다. 동일한 분자량을 가지는 알린과 이소알린을 분별하기 위해 $^1H$-NMR를 그리고 ${\gamma}$-glutamyl-S-allylcysteine과 ${\gamma}$-glutamyl-S-1-propenylcysteine을 구별하기 위해 $^1H$-NMR과 $^{13}C$-NMR분석을 수행하였다.

• Applied Biological Chemistry
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• 제35권1호
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• pp.55-63
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• 1992

봉동산 생강(Zingiber officinale Roscoe)의 정유성분조성을 분석코자 액체 이산화탄소 주출법으로 분리하여 silica gel column chromatography범에 의해 탄화수소 화합물 분획과 함산소 화합물 분획으로 분류한 다음 GC 및 GC-MS로 성분을 검토하였다. 추출물의 수율은 6.96%이었으며, SCC에 의해 분리된 분획의 분석결과 mass spectrum에 의해서 잠정적으로 확인된 58종을 포함하여 102종의 향기성분이 확인되었다. 중 탄화수소 화합물 분획에서는 zingiberene, ${\beta}-sesquiphellandrene,\;{\gamma}-bisabolene,\;{\gamma}-cadinene,\;ar-curcumene$ 등이 주성분이었고, 함산소 화합물 분획에서는 gernal, sesquisabinene hydrate, borneol, zingiberenol 등이 주성분 이었다. 총 essential oil의 조성은 $zingiberene,\;citronellol+{\beta}-sesquiphellandrene,\;geranial,\;{\gamma}-bisabolene,\;ar-curcumene+geranyl\;acetate$ 등이 주성분으로 sesquiterpene hydrocarbon의 함량이 높게 나타났다.

• Nuclear Engineering and Technology
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• 제54권5호
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• pp.1754-1759
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• 2022

The activity of gamma-ray emitting nuclides is calculated assuming that each gamma-ray is detected individually; thus, the magnitude of the coincidence summing signal must be considered during activity calculations. Here, the correction factor for the coincidence summing effect was calculated, and the detection efficiencies of two HPGe detectors were compared. The CANBERRA Inc. GC4018 high-purity Ge detector provided an estimate for the peak-to-total ratio using a point source to determine the coincidence summing correction factor. The ORTEC Inc. GEM60 high-purity Ge detector uses EFFTRAN in LVis to obtain the parameters of the detector and source model and the gamma-gamma and gamma-X match estimates, in order to determine the coincidence summing correction factor. Nuclide analyses, radioactivity comparisons, and analyses of reference material samples were performed utilizing certified reference materials to accurately determine the detection efficiencies. For both Co-60 and Y-88, the detection efficiency for a point source increased by an average of at least 12-13%, whereas the detection efficiency determined using LVis increased by an average of at least 13-15%. The calculated radioactivity values of the certified reference material and reference material samples were accurate to within 3% and 6% of the measured values, respectively.

• Nuclear Engineering and Technology
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• 제49권7호
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• pp.1489-1494
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• 2017

The use of a room-temperature gamma spectrometer is an issue in environmental radiation monitoring. To monitor radionuclides released around a nuclear power plant, suitable instruments giving fast and reliable information are required. High-pressure xenon (HPXe) chambers have range of resolution and efficiency equivalent to those of other medium resolution detectors such as those using NaI(Tl), CdZnTe, and $LaBr_3:Ce$. An HPXe chamber could be a cost-effective alternative, assuming temperature stability and reliability. The CEA LIST actively studied and developed HPXe-based technology applied for environmental monitoring. Xenon purification and conditioning was performed. The design of a 4-L HPXe detector was performed to minimize the detector capacitance and the required power supply. Simulations were done with the MCNPX2.7 particle transport code to estimate the intrinsic efficiency of the HPXe detector. A behavioral study dealing with ballistic deficits and electronic noise will be utilized to provide perspective for further analysis.