• Journal of Korean Society on Water Environment
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• v.40 no.3
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• pp.131-139
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• 2024

This study investigated the chemical properties of Organic Soil Amendments (OSAs) made from organic waste. It also assessed the effectiveness of using these OSAs in the soil layer of Green Infrastructure (GI) to reduce stormwater runoff and non-point source pollutants. The goal was to improve the national environmental value through resource recycling and contribute to the circular economy transformation and carbon neutrality of urban GI. The OSAs used in this study consisted of spent coffee grounds and food waste compost. They were found to be nutrient-rich and stable as artificial soils, indicating their potential use in the soil layer of GI facilities. Applying OSAs to bio-retention cells and permeable pavement resulted in a reduction of approximately 11-17% in stormwater runoff and a decrease of about 16-18% in Total Phosphorus (TP) discharge in the target area. Increasing the proportion of food waste compost in the OSAs had a positive impact on reducing stormwater runoff and pollutant emissions. This study highlights the importance of utilizing recycled resources and can serve as a foundation for future research, such as establishing parameters for assessing the effectiveness of GI facilities through experiments. To enable more accurate analysis, it is recommended to conduct studies that consider both the chemical and biological aspects of substance transfer in OSAs.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2004.06a
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• pp.32-42
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• 2004

Recently, plasma surface-cleaning or surface-etching techniques have been focused in respect of the decontamination of spent or used nuclear parts and equipment. In this study the removal rate of metallic cobalt surface is experimentally investigated via its surface etching rate with a $CF_4-o_2$mixed gas plasma. Experimental results reveal that a mixed etchant gas with about 80% $CF_4$-20% $O_2$ (molar) gives the highest reaction rate and the rate reaches 0.06 ${\mu}m$/min at $380^{\circ}C$ and ion-assisted etching dramatically enhances the surface reaction rate. With a negative 300 V DC bias voltage applied to the substrate, the surface reaction initiation temperature lowers and the rate increases about 20 times at $350^{\circ}C$ and up to 0.43 ${\mu}m$/min at $380^{\circ}C$, respectively. Surface morphology analysis confirms the etching rate measurements. Auger spectrum analysis clearly shows the adsorption of fluorine atoms on the reacted surface. From the current experimental findings and the results discussed in previous studies, mechanistic understanding of the surface reaction, fluorination and/or fluoro-carbonylation reaction, is provided.

• Journal of the Korean Home Economics Association
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• v.32 no.5
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• pp.135-142
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• 1994

This research was undertaken to investigate the state of lunchbox preperation and the opinion of operating school lunch program. The subjects were 180 mothers and their children in the 6th grade of elementary school in Seoul, where a school lunch program were not operated. The results were summarized as follows ; The age of mothers were from 30's to 40's and among them over 80% graduated from a high school and 26.1% had a job. 88.9% of mothers prepared lunchbox everytime and main dish was mostly bab. The average time spent in preparing meal for one day and lunchbox were 1 hour and 58 minutes, and 28.6 minutes respectively. The number of side dishes cooked per day and for lunchbox were 9 and 3, respectively. The side dishes for lunchbox were kimchi, dried layer, ham, dried squid, egg in decreased order, which were similar to preference of children. Animal protein foods were mainly used in lunchbox than vegetables. On preparing lunchbox, mothers considered preferance, nutrition, convenience of cook, economic, appearance of food in decreased order. 92% of mothers and 75% of their children approved of operating school lunch program, and the reason, answered by their mothers, was nutritional balance of their children. In conclusion, it's needed to operate of school lunch program for optimal nutritional intake and growth of children.

• Resources Recycling
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• v.8 no.3
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• pp.18-25
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• 1999

The study on the electrosorption of cobalt ions onto a porous activated carbon fiber (ACF) was performed to treat radioactive liquid wastes resulting from chemical or electrochemical decontamination and to regenerate the spent carbon electrode, Cyclic voltammetry was investigated on a rotating-disk electrode (RDE) to determine the region of potentials within which only double-layer charging should occur. The application of an electric potential increased the sorption of the cobalt ions. The adsorbed cobalt Ions could be released into the solution by reversing the appling potential, showing the reversibility of the process.

• Nuclear Engineering and Technology
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• v.53 no.8
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• pp.2454-2463
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• 2021

The objective of this research is to the use of americium (AmO₂) as a burnable absorber effectively instead of conventional gadolinium (Gd₂O₃) for VVER-1200 reactor by analyzing its impacts on reactivity, power peaking factor (PPF), safety factor, and quality of the spent fuel. The assembly is burned to 60 GWd/t by using SRAC-2006 code and JENDL-4.0 data library for finding the optimum amount and effective way of using AmO₂ as a burnable absorber. From these studies, it is found that AmO₂ can decrease the excess reactivity like Gd₂O₃ without changing the criticality life span and enrichment of ²³⁵U. A homogeneous mixture of the 0.20% AmO₂+ 4.95% enriched UO₂ fuel rod (model MF-4) decreases the PPF than the reference assembly. The use of AmO₂+UO₂ in the integral burnable absorber (IBA) rod or the outer layer could also decrease the PPF up to 10 GWd/t but increases rapidly after 30 GWd/t, which could be a safety threat. The fuel temperature coefficient and void coefficient of the model MF-4 are the same as the reference assembly. In addition, 22% of initially loaded Am are burning effectively and contributing to the power production.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.19 no.1
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• pp.9-27
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• 2021

As an example of research activities in decontamination for decommissioning, new data are presented on the options for corrosion layer dissolution during the decommissioning decontamination, or persulfate regeneration for decontamination solutions re-use. For the management of spent decontamination solutions, new method based on solvent extraction of radionuclides into ionic liquid followed by electrodeposition of the radionuclides has been developed. Fields of applications of composite inorganic-organic absorbers or solid extractants with polyacrylonitrile (PAN) binding matrix for the treatment of liquid radioactive waste are reviewed; a method for americium separation from the boric acid containing NPP evaporator concentrates based on the TODGA-PAN material is discussed in more detail. Performance of a model of radionuclide transport, developed and implemented within the GoldSim programming environment, for the safety studies of the LLW/ILW repository is demonstrated on the specific case of the Richard repository (Czech Republic). Continuation and even broadening of these activities are expected in connection with the approaching end of the lifespan of the first blocks of the Czech NPPs.

• Korean Journal of Poultry Science
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• v.29 no.1
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• pp.45-52
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• 2002

Cryoprotective effects on chicken surimi during storage were investigated. Chicken surimi from mechanically deboned spent layer meat was prepared with 4 volumes of 0.5% NaCl washing, and then blended with or without cryoprotectants (8% trehalose, 8% oligosaccharide) prior to frozen storage at $-18^{\circ}C$ to 10 weeks Redness (a) of all surimi decreased during storage. Color stability increased during storage when lightness increased but redness decreased. At this Point, surimi maintained a better color quality as followed order; trehalose > oligosaccharide ) non-additive. Gel strength such as compressive force, hardness, adhesiveness and gumminess tended to decrease during frozen storage. Cryoprotectants provided significantly better textural properties than non-auditive. Surimi with trehalose showed the highest adhesiveness. In conclusion, trehalose and oligosaccharide seemed to be good cryoprotectants of chicken surimi. Especially, trehalose resulted in better cryoprotectant than oligosaccharide because of better color stability, better textural properties, and lower sweet characteristics.

• Korean Journal of Materials Research
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• v.26 no.12
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• pp.681-687
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• 2016

Zirconium(Zr) nuclear fuel cladding tubes are made using a three-time pilgering and annealing process. In order to remove the oxidized layer and impurities on the surface of the tube, a pickling process is required. Zr is dissolved in HF and $HNO_3$ mixed acid during the process and pickling waste acid, including dissolved Zr, is totally discarded after being neutralized. In this study, the waste acid was recycled by adding $BaF_2$, which reacted with the Zr ion involved in the waste acid; $Ba_2ZrF_8$ was subsequently precipitated due to its low solubility in water. It is very difficult to extract zirconium from the as-recovered $Ba_2ZrF_8$ because its melting temperature is $1031^{\circ}C$. Hence, we tried to recover Zr using an electrowinning process with a low temperature molten salt compound that was fabricated by adding $ZrF_4$ to $Ba_2ZrF_8$ to decrease the melting point. Change of the Zr redox potential was observed using cyclic voltammetry; the voltage change of the cell was observed by polarization and chronopotentiometry. The structure of the electrodeposited Zr was analyzed and the electrodeposition characteristics were also evaluated.

• Journal of Microbiology and Biotechnology
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• v.16 no.11
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• pp.1706-1712
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• 2006

Because of the need for new antimicrobial substances with novel mechanisms of action, we report here the use of an Acinetobacter reporter system for high-throughput screening of active antimicrobial agents. The bioreporter Acinetobacter strain DF4/PUTK2 carrying luciferase genes luxCDABE was chosen because of its ecological importance and it is widespread in nature. This bioreporter is genetically engineered to emit light constitutively that can be measured in real time by luminometry. Hence, this reporter system was employed to determine the bacteriostatic actions of spent-culture supernatants derived from twelve bacterial isolates. Out of the results, the strongest bioluminescence inhibitory effect of the supernatants was recorded with Bacillus cereus strain BAC (S5). Subsequently, ethyl acetate extracts of extracellular products of strain BAC (S5) were separated by a thin-layer chromatography (TLC). Based on the bioluminescence inhibitory assay, three fractions were found to have antimicrobial activity. One fraction (C) having the strongest antimicrobial activity was further purified using TLC and characterized by IR, $^1H$ NMR, mass spectrometry, SDS-PAGE, and amino acid composition analysis. The results predicted the presence of 2-pyrrolidone-S-carboxylic acid (PCA) and the octadeconic-acid-like fatty acid. Fraction C also demonstrated a broad inhibitory activity on several Gram-negative and Gram-positive bacteria. In conclusion, the Acinetobacter reporter system shows great potential to be a reliable, sensitive, and real-time indicator of the bacteriostatic actions of the antimicrobial agents.

• The Journal of the Korea Contents Association
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• v.16 no.10
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• pp.701-710
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• 2016

Perspective of director Bong Joon-ho shown in his movies up to now had been limited to domestic issues but that in the was shifted to the world, mankind, and future of humans. Images exhibited in his movies had the same meanings of many stories in the Bible and myths. The study looks into his philosophical world through the Christian view of the world and the Oriental circulation thinking; the story of the was expressed in before the glacial period, the 17 year glacial period spent in a train, and after the glacial period; structure of the story was composed of allegory as prior to Israelites' Escape from Egypt, desert life for 40 years, and entrance to Canaan. The end in the Bible does not mean complete collapse but it contains aspiration for new heaven and new earth to open a new era, to make a new promise with the God and to live a permanent life. This study intends to interpret the developed in a quite different meaning of imagination of humans' future from the previous one by the director Bong Joon-ho and to make another different explanation underlying in the image projected on the surface layer by the director.