• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.13 no.2
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• pp.51-58
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• 2007

This research investigated the effect of different onggi containers (Korean earthenware) on the ripening of kochujang (Korean hot pepper paste). The physical characteristics of 'onggi', were evaluated as function of manufacturing variables such as raw material soils (onggi-specific soil, red brown soil, and fine powdered soil) and galzing treatments. The physical properties were then related to the compositional quality changes of the kochujang fermented at $30^{\circ}C$ for 4 months. The porosity of the onggi containers seems to be increased by the content of finer raw soil rather than the chemical component of soil (amount of CaO, MgO, $K_2O$ and $Na_2O$, acting as melting aid in the firing). Natural glaze was measured to contain higher contents of CaO, MgO, $K_2O$ and $Na_2O$ than the other soils, which is desirable property for the fired onggi. The glazed surface showed higher far-infrared radiation emissivity than the non-glazed part. The kochujang fermented in P0-BG (the glazed onggi from 100 % onggi soil) attained higher concentration of reducing sugar, amino nitrogen and nucleotides compared to those in the other onggis. All of these changes of kochujang in P0-BG resulted in significantly better sensory quality than the other treatments.

• Food Science and Preservation
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• v.9 no.1
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• pp.85-91
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• 2002

Quality changes of over-wintering satsuma mandarin (Citrus unshiu Marc. var. miyagawa) during storage by chitosan and calcium treatment and type of storage warehouse were investigated. Citrus were treated with 2000-folds diluted iminoctadime-triacetate solution and 1.5% chitosan with 0.5% CaCl$_2$ solutions and were at 30$\^{C}$ far 24 h before storage. The citrus of about 12 kg/26 L plastic container were stored at room temperature, and at 4$\^{C}$ with 87% relative humidity. Chitosan and CaCl$_2$ solution treated citrus fruits were showed lower in decay ratio than the ones without treatment. Also, these chitosan and calcium treated citrus fruits skewed less in weight loss, that seems it also has restraining effect of fruits' transpiration. Decay ratio of citrus with precise temperature and humidity control were lower than the others during storage. Weight loss, moisture content of peel and flesh were decreased slowly during storage. 0.84 ∼0.90% of acid content were decreased on 120 days' storage. Reducing sugar of citrus was decreased rapidly after 90 days, and vitamin C content were also decreased rapidly after 60 days during storage.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.8 no.1
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• pp.179-186
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• 1998

We have been investigated the effects of the initial pH of the aquous solution, reaction temperature and time for the flaking of the soda-lime glass container. Flaking of glass occuurred in the cases of the $121^{\circ}C$, above pH 11 of solution with no $Mg^{2+}$ ions in solution. The pH of the solution approached to pH 10 under the conditions of below pH 9 of start solution. The flaking mechanism of the glass seem to be composed of formation of leached layer of $Ca^{2+}$ and $Na^{2+}$ ion and separation of these layers during the cooling by the difference of thermal expansion between leached layer and glass surface. The leaching of alkali ions in glass depends on the pH condition of the start solution and the temperature. In the case of $Mg^{2+}$ ions are added, $Mg^{2+}$ ions accelerate the flaking of the sodalime glasses and forms the magnesium silicate compound which result in the decrease of the pH of the solution.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.14 no.2
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• pp.135-147
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• 2016

The buffer in geological disposal system is one of the major elements to restrain the release of radionuclide and to protect the container from the inflow of groundwater. The buffer material requires long-term stability, low hydraulic conductivity, low organic content, high retardation of radionuclide, high swelling pressure, and high thermal conductivity. These requirements could be determined by the quantitative analysis results. In case of South Korea, the bentonites produced in Gyeongju area have been regarded as candidate buffer/backfill materials at KAERI (Korea Atomic Energy Research Institute) since 1997. According to the study on several physical and chemical characteristics of domestic bentonite in the same district, this is the Ca-type bentonite with about 65% of montmorillonite content. Through this study, we present the criteria for the performance evaluation items and methods when collecting new buffer/backfill materials.

• Food Science and Preservation
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• v.9 no.2
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• pp.131-136
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• 2002

Quality changes of satsuma mandarin (Citrus unshiu Marc. var. miyagawa) during storage by storage warehouse were investigated. Citrus were treated with 2000-folds diluted iminoctadime-triacetate solution and 1.5% chitosan with 0.5% CaCl$_2$ solution, and were at 30$\^{C}$ for 24 hr before storage. The citrus of about 12kg/26L plastic container were stored at room temperature, and at 4$\^{C}$ with 87% relative humidity. Decay ratio of citrus with precise temperature and humidity control were lower than the others during storage. Penicillium italicum Monilia candida Alternara citri, Mucor hiemalis, Phomopsis citri Botrytis cinerea, Phoma citricarpa Clomererella cingulata, Penicillium digitatum were identified as putrefactive microorganisms in citrus storage. Weight loss, moisture content of peel and flesh were decreased slowly during storage. 24% of original acid content were decreased at room temperature on 120 days storage, compared to 15∼18% loss on cold storage. Total sugar of citrus was decreased rapidly after 90 days, and vitamin C content were also decreased rapidly after 60 days during storage.

• Food Science and Preservation
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• v.10 no.2
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• pp.147-153
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• 2003

Quality changes of citrus tangor(Citrus kiyomi) during storage by chitosan and calcium treatment and storage warehouse were investigated. Citrus fruits were treated with 2000-folds diluted iminoctadime-triacetate solution, and 1.5% chitosan with 0.5% CaC1$_2$solution, and were at 30$^{\circ}C$ for 24 hr before storage. The citrus fruits of about 12 kg/26 L plastic container were stored at 4$^{\circ}C$ with 87% relative humidity. Decay ratio of citrus with precise temperature and humidity control were lower than the others during storage. Weight loss, moisture content of peel and flesh were decreased slowly during storage. 15 ∼ 18% of acid content were decreased on 120 days' storage. Vitamin C content were decreased rapidly during storage. 23 free amino acids were detected. Isoleucine and leucine were not detected, but alanine was detected only on stored citrus. Citrus fruits was kept well on its commodity quality for 3 month at 4$^{\circ}C$ with 87% relative humidity.

• Journal of Bio-Environment Control
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• v.29 no.2
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• pp.141-152
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• 2020

The rapid on-site measurement of hydroponic nutrients allows for the more efficient use of crop fertilizers. This paper reports on the development of an embedded on-site system consisting of multiple ion-selective electrodes (ISEs) for the real-time measurement of the concentrations of macronutrients in hydroponic solutions. The system included a combination of PVC ISEs for the detection of NO₃, K, and Ca ions, a cobalt-electrode for the detection of H₂PO₄, a double-junction reference electrode, a solution container, and a sampling system consisting of pumps and valves. An Arduino Due board was used to collect data and to control the volume of the sample. Prior to the measurement of each sample, a two-point normalization method was employed to adjust the sensitivity followed by an offset to minimize potential drift that might occur during continuous measurement. The predictive capabilities of the NO₃ and K ISEs based on PVC membranes were satisfactory, producing results that were in close agreement with the results of standard analyzers (R² = 0.99). Though the Ca ISE fabricated with Ca ionophore II underestimated the Ca concentration by an average of 55%, the strong linear relationship (R² > 0.84) makes it possible for the embedded system to be used in hydroponic NO₃, K, and Ca sensing. The cobalt-rod-based phosphate electrodes exhibited a relatively high error of 24.7±9.26% in the phosphate concentration range of 45 to 155 mg/L compared to standard methods due to inconsistent signal readings between replicates, illustrating the need for further research on the signal conditioning of cobalt electrodes to improve their predictive ability in hydroponic P sensing.

• Journal of the Korean Society of Marine Environment & Safety
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• v.25 no.7
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• pp.906-913
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• 2019

To evaluate the removal performance of PO₄-P and NH₃-N, laboratory experiments were conducted by filling a container with oyster shells, pyrolyzed at 100℃ (POS100), 600℃ (POS600) and 800℃ (POS800), and passing artificial wastewaters through the container. The pH in the ef luent was found to increase due to CaO eluted from oyster shell. Removal amounts of PO₄-P of ~23.1 mg/kg, 16.1 mg/kg, and 15.9 mg/kg were obtained when POS100, POS600, and POS800, respectively, were used; therefore, the highest PO₄-P removal amount was obtained when POS100 was used. It is considered that Ca and dolomite in the oyster shells adsorbed and precipitated PO₄-P. Removal amounts of NH₃-N were of ~3.56 mg/kg, 5.72 mg/kg, and 3.97 mg/kg were obtained when POS100, POS600, and POS800, respectively, were used The low removal rate for NH₃-N is probably due to unstable nitrification, use of sealed containers, and the effect of NH₃-N being converted to NH₄⁺ upon increasing pH. Based on these results, pyrolyzed oyster shell is expected to promote changes in PO₄-P and NH₃-N concentrations through chemical reactions. These results can also be used for basic research in the development of wastewater treatment.

• Nuclear Engineering and Technology
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• v.54 no.2
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• pp.601-607
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• 2022

In recent years, monitoring of spent nuclear fuel inside dry cask storage has become an important area of national security. Muon tomography is a useful method for monitoring spent nuclear fuel because it uses high energy muons that penetrate deep into the target material and provides a 3-D structure of the inner materials. We designed a muon tomography system consisting of four 2-D position sensitive detector and characterized and optimized the system parameters. Each detector, measuring 200 × 200 cm², consists of a plastic scintillator, wavelength shifting (WLS) fibers and, SiPMs. The reconstructed image is obtained by extracting the intersection of the incoming and outgoing muon tracks using a Point-of-Closest-Approach (PoCA) algorithm. The Geant4 simulation was used to evaluate the performance of the muon tomography system and to optimize the design parameters including the pixel size of the muon detector, the field of view (FOV), and the distance between detectors. Based on the optimized design parameters, the spent fuel assemblies were modeled and the line profile was analyzed to conduct a feasibility study. Line profile analysis confirmed that muon tomography system can monitor nuclear spent fuel in dry storage container.

• Korean journal of applied entomology
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• v.41 no.3
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• pp.225-231
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• 2002

The entomopathogenic nematodes, Steinernema carpocapsae All strain (ScA), S.glaseri NC strain (SgN) and H. bacteriophora NC 1 strain (HbN), were evaluated for the effects on egg mass formation by the northern root-knot nematode, Meloidogyne hapla in pot experiment using tomato. In the first experiment, 2.5$\times$10$^{5}$ infective juveniles (Ijs) of entomopathogenic nematodes were inoculated to 100 g of the soil infected with ca. 450 Ijs of M. hapla/100 ㎤ in 150 $mell$ container. The number of egg mass was significantly decreased to 9.4-36.5 in ScA, to 5.7-24.7 in SgN and to 11.2-16.0 in HbN treatments compared with 62.5 in M.hapla alone. In the second experiment, ScA and S.carpocapsae Pocheon strain (ScP) and SgN and S.glaseri Dongrae strain (SgD) were treated to 350 g of the soil infected with 100, 200 M.hapla larvae/100 ㎤ in 450 $mell$ container The entomopathogenic nematodes were inoculated at the rate of 2,020 Ijs and 1.6$\times$105 Ijs in 350 g soil. The number of egg mass of M.hapla were significantly decreased in the entomopathogenic nematode treatments compared with M.hapla alone although no differences were observed among Steinernema species, strains, or infection concentrations. Treatments of entomopathogenic nematodes 3 days before M.hapla inoculation were more effective on reduction of egg mass formation than those of 3 days after M.hapla treatments. Growth of tomato was not affected by entomopathogenic nematode treatments.