• Journal of Radiation Industry
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• v.8 no.1
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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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• v.54 no.12
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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.

• Journal of Soil and Groundwater Environment
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• v.18 no.1
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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.

• Korean Journal of Medicinal Crop Science
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• v.5 no.2
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• pp.113-118
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• 1997

Phytochemical analysis on rice bran and its pitch was performed by the tool of TLC, UV- and IR-spetroscopy, so that it was found that they contained ${\gamma}-oryzanol$ and free sterol. GC-MS analysis of free sterol revealed that it was composed of ${\beta}-sitosterol$, campesterol and stigmasterol. Successive phytochemical analysis of ${\gamma}-oryzanol$ revealed that it was composed of ferulic acid ester of triterpene and sterol, respectively. Triterpene moieties of ${\gamma}-oryzanol$ were identified as follows: cycloartanol, cycloartenol, 24-methylenecycloartanol and unknown triterpene; And sterol moieties were found to be identical with free sterols. In addition, characteristic absorption band in UV spectrum (220-340 nm) was exclusively due to ${\gamma}-oryzanol$. Thus, it was suggested that rice brans of nearly all species of Oryza sativa can be quantitatively analyzed by UV absorption spectrometry, even when water soluble pigments was contained in the rice bran.

• Korean Journal of Food Science and Technology
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• v.43 no.5
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• pp.553-557
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• 2011

Garlic specific organic compounds were separated and purified using a recycling preparative high-performance liquid chromatography (HPLC) from blanched garlic cloves. Identification of the compounds involved comparing the previously reported HPLC retention times as well as other identification methods including $^1H$- and $^{13}C$-nuclear magnetic resonance and liquid chromatography-mass spectrometry. The yields of garlic specific organic compounds were 12.2, 42.5, 1.6, 1.2, and 4.8% on wet weight basis of garlic for alliin(S-allyl-L-cysteine sulfoxide), isoalliin(S-1-propenyl-L-cysteine sulfoxide), ${\gamma}$-glutamyl-S-allylcysteine, ${\gamma}$-glutamyl-S-1-propenylcysteine and ${\gamma}$-glutamyl-phenylalanine, respectively. All the compounds, except for ${\gamma}$-glutamylphenylalanine, contained sulfur.

• Applied Biological Chemistry
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• v.35 no.1
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• pp.55-63
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• 1992

The essential oil of Korean ginger(Zingiber officinale Roscoe) was isolated by liquid carbon dioxide extraction method and fractionated into one hydrocarbon fraction and two oxygenated hydrocarbon fractions by using silica gel column chromatography. The compositions of the resulting oils were investigated by GC and GC-MS spectrometry. Out of 102 identified compounds, 44 were identified by comparing GC retention time and mass spectral data with authentic samples and 58 were tentatively identified according to mass spectral data only. The major compounds of hydrocarhon fraction were $zingiberene,\;{\beta}-sesquiphellandrene,\;{\gamma}-bisabolene,\;{\gamma}-cardinene,\;ar-curcumene$, and those of oxygenated hydrocarbon fractions wee geranal, sesquisabinene hydrate, borneol and zingiberenol. The major compounds of ginger oil were zingiberene, $citronellol+{\beta}-sesquiphellandrene,\;geranial,\;{\gamma}-bisabolene\;and\;ar-curcumene+geranyl\;acetate$, and ginger oil contained higher amounts of sesquiterpene hydrocarbons. The yield of extract was 6.96%.

• Nuclear Engineering and Technology
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• v.54 no.5
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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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• v.49 no.7
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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.

• Journal of the Korean Society of Food Science and Nutrition
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• v.19 no.3
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• pp.239-247
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• 1990

The oxidation products from the mixture of a-tocopherol (a-Toc) and γ-tocopherol)(γ-Toc) during autoxidation of methyl linoleate were isolated and identified. The sturctures of the oxida-tion products were characterized by UV, IR, 1H and 13CNMR and mass spectrometry 5-[2-(a-tocopherol-5'-yl)ethyl]-a-tocopherylquinone 5-[2-(a-tocopherol-5'-yl)ethyl]-8a-hydroxy-a-tocopherone and O-[8-(5-ethoxymethyl-7-methyltocol) methyl] a-tocopherol were obained from the mixture as the oxidation products derived from γ-Toc However oxidation product composed of both a-ToC and γ-Toc was detected in oxidation products of the misture. These results support the facts that at first oxidation of a-Toc proceeds during autoxidation of lipids and then γ-Toc decomposes after approximate consumption of a-Toc.

• Nuclear Engineering and Technology
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• v.55 no.12
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• pp.4472-4476
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• 2023

In this study, it has been shown that the true coincidence summing correction factor can be obtained for the first time using the PHITS Monte Carlo program. Determining this correction factor using different methods and tools in each laboratory to increase the possibility of achieving high-efficiency measurement conditions is still popular in gamma-ray spectrometry. By using ¹³³Ba, ¹⁵²Eu, ¹³⁴Cs, and ⁶⁰Co point sources, the true coincidence summing factor was investigated in both near and far counting geometries for 15 different energy values. GESPECOR software was used to validate the results obtained with PHITS. A remarkable agreement was obtained between PHITS and GESPECOR, with a discrepancy of less than 3%. With this study, a new tool has been proposed to obtain the true coincidence summing factor, which is one of the significant correction factors investigated/calculated in gamma-ray spectrometric studies.