• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.19 no.4
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• pp.79-84
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• 2005

This paper proposes the new type of an ion exchange water generator system. The system has an +/- ion exchange membrane located in center and a diagonal-interdigit type electrode applied to a pulsed power. This system is studied in the liquid for the oxidation/reduction potential and the dissolved oxygen concentration by the polarity effects. Consequently, as a diagonal-interdigit type electrode is installed in each side of device, the oxidation/reduction potential and dissolved oxygen concentration by polarity changes and electrical resistivity differences be observed. An ion concentration in the ion exchange water generator system is increased by dissolved oxygen generated from oxidation/reduction potential changes.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2005.11b
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• pp.86-91
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• 2005

A metal product obtained from an electrolytic reduction process, possesses less volume and radioactivity than those of the unprocessed spent oxide fuels. The chemical composition of the metal product varies according to the process condition. In this work, a basic study was performed to evaluate the chemical forms of the spent oxide fuel components in an electrolytic reduction process with the operation conditions. One of the most important operation conditions is the cell potential applied for the reduction cell. It is expected that $PU_{2}O_3$ is difficult to reduce even though the cell potential is negative enough to reduce the lithium oxide when the activity of $Li_{2}O$ exceeds 0.003. The reduction of actinide oxides via the reduction of $Li_{2}O$ is assumed to have a greater reduction yield than a direct reduction of the actinide oxides.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.12 no.2
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• pp.95-105
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• 2009

Land Use Changes (LUCs) have effects on greenhouse gas emissions and carbon stocks in soil and vegetation. Therefore, predictions for LUC are very important for achieving quantitative targets of $CO_2$ reduction rates. Some research exists on carbon fluxes and carbon cycles to estimate carbon stocks in terrestrial ecosystems in Korea. However, these researches have limitations in terms of helping us understand future potential reductions of $CO_2$ that reflect the influence of LUC. The aim of this study is to analyze the reduction levels of $CO_2$ emissions while considering LUC scenarios that effect carbon fluxes for LCS basic study in the year 2030. In this study, a common approach to model the effects of LUC on carbon stocks is the use of CA-Markov technical process with LUC patterns in the past. Potential reduction of $CO_2$ is calculated by change of land use that contains different soil organic carbon, each land use type, and biomass in vegetation. An IPCC analytical method of natural carbon sink and coefficient results from previous study in Korea is used as a calculation method for potential reduction of $CO_2$. As a result, 12,419 KtC will be reduced annually, which is 8.3% percent of 2005 $CO_2$ emissions in Korea. This will result in 3,226 hundred million won of economic efficiency. In conclusion, conservation of natural carbon sinks is necessary even if the amount of potential reduction change is little.

• Textile Coloration and Finishing
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• v.32 no.4
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• pp.193-198
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• 2020

In this study, the validity of extracts from food waste as biocatalyst for indigo reduction was examined. Dried food wastes such as apple peel and corn waste were water-extracted and freeze-dried. The reducing power of extracts for indigo was evaluated by the oxidation-reduction potential(ORP) measurement of reduction bath and color strength(K/S value) of the fabrics dyed in the indigo reduction bath. Total sugar contents of the apple peel and corn waste extracts were 60.56% and 62.36%, respectively. Antioxidant activity was 64.78% for the extract of apple peel and 7.96% for the extract of corn waste. Indigo reduction took place quickly with both extracts, and maximum color strength was obtained up to 15.91 and 12.11 within 1-3 days, respectively. The oxidation-reduction potential of reduction bath was stabilized in the range of -500 ~ -620 mV according to the kinds of food waste and the extract concentration. At higher concentration of the extracts, reduction power was maintained for longer time and stronger color strength was obtained. Compared to sodium dithionite, the reducing power of the studied extracts was lower, but the reduction stability was superior to it. The studied extracts were effective biocatalyst as biodegradable and safe alternatives to sodium dithionite for indigo reduction.

• Journal of People, Plants, and Environment
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• v.24 no.4
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• pp.377-387
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• 2021

Background and objective: To improve air quality, particulate matter (PM) can be reduced using green infrastructure. Therefore, in this study, we aimed to determine the particulate matter reduction potential of climbing plants used for green walls, an element of vertical green infrastructure. Methods: A sealed chamber with controlled environmental variables was used to assess the PM reduction level caused by climbing plants. PM concentration in the plant chamber was measured after two and four hours of PM exposure, and the reduction potential was assessed based on the leaf area. Results: Compared to the empty chamber (Control), the PM reduction speed per hour was higher in the plant chamber, which confirmed that climbing plants contribute to the reduction of PM in the air. The PM reduction speed immediately after exposure in the plant chamber was high, but this slowed over time. Additionally, PM has been continuously reduced in plants with large leaves. As a result of calculating the particulate matter reduction level based on leaf area, it was found that there was a difference by particle size. Actinidia arguta, Parthenocissus tricuspidata, Trachelospermum asiaticum, and Euonymus fortunei var. radicans showed a high reduction effect. The trichomes on the leaf surface of Trachelospermum asiaticum were found to affect PM reduction. Conclusion: PM adsorption on the leaf surface is an important factor in reducing its concentration. It was possible to compare different plants by quantifying the amount of PM reduction during a fixed time period. These results can be used as the basic data to select the plant species suitable for urban green walls in terms of PM reduction.

• Clean Technology
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• v.6 no.1
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• pp.79-84
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• 2000

In this study, to reduce the consumption of chemicals in cleaning processes, Si-wafers contaiminated with metallic impurities were cleaned with electrolyzed water(EW), which was generated by the electrolysis of a diluted electrolyte solution or ultra pure water(UPW). Electrolyzed water could be controlled for obtaining wide ranges of pH and ORP(oxidation-reduction potential). The pH and oxidation-reduction potential of anode water and cathode water were measured to be 4.7 and +1000mV, and 6.3 and -550mV, respectively. To analyze the amount of metallic impurities on Si-wafer surfaces, ICP-MS was introduced. Anode water was effective for Cu removal, while cathode water was more effective for Fe removal.

• Journal of the Korean Chemical Society
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• v.18 no.5
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• pp.341-353
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• 1974

The electrochemical reduction of triphenylphosphine penylimide in nonaqueous media has been examined by polarography, cyclic voltammetry, controlled-potential coulometry and electron spin resonance spectroscopy. The reduction of triphenylphosphine phenylimide proceeds by a one-electron transfer to form anion radical which undergoes both protonation and a second one-electron reduction followed by cleavage of the phosphorus-nitrogen double bond. Aniline is a major product. The cleavage of a phosphorus-phenyl bond was also observed after reduction of triphenylphosphine oxide which is one of the major products of the chemical reaction which follow the primary process.

• Bulletin of the Korean Chemical Society
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• v.27 no.11
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• pp.1763-1768
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• 2006

The application of poly(Co(II)-(1,8-diaminonaphthalene))(poly(Co-DAN)) and poly(1,8-diaminonaphthalene) (Poly(1,8-DAN)) to the electrocatalytic reduction of molecular oxygen was investigated, which were electrochemically grown by the potential cycling method on the glassy carbon electrodes. The reduction of oxygen at the polymer and its metal complex polymer coated electrodes were irreversible and diffusion controlled. The Poly(1,8-DAN) and Poly(Co-DAN) films revealed the potential shifts for the oxygen reduction to 30 mV and 110 mV, respectively, in an aqueous solution, compared with that of the bare electrode. Hydrodynamic voltammetry with a rotating ring-disk electrode showed that Poly(1,8-DAN) and Poly(Co-DAN) coated electrodes converted respectively 84% and 22% of $O_2$ to $H_2O$ via a four electron reduction pathway.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2005.11b
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• pp.39-50
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• 2005

Electrolytic reduction of uranium oxide to uranium metal was studied in a $LiCl-Li_{2}O$ molten salt system. The reduction mechanism of the uranium oxide to a uranium metal has been studied by means of a cyclic voltammetry. Effects of the layer thickness of the uranium oxide and the thickness of the MgO on the overpotential of the cathode and the anode were investigated by means of a chronopotentiometry. From the cyclic voltamograms, the decomposition potentials of the metal oxides are the determining factors for the mechanism of the reduction of the uranium oxide in a $LiCl-3\;wt{\%} Li_{2}O$ molten salt and the two mechanisms of the electrolytic reduction were considered with regards to the applied cathode potential. In the chronopotentiograms, the exchange current and the transfer coefficient based on the Tafel behavior were obtained with regard to the layer thickness of the uranium oxide which is loaded into the porous MgO membrane and the thickness of the porous MgO membrane. The maximum allowable currents for the changes of the layer thickness of the uranium oxide and the thickness of the MgO membrane were also obtained from the limiting potential which is the decomposition potential of LiCl.

• Journal of Climate Change Research
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• v.5 no.3
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• pp.219-230
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• 2014

In this study, greenhouse gas emission of magnesium industry was estimated and the reduction potential of the greenhouse gas emission was evaluated with reduction technologies. Default value of IPCC guideline was used to calculate the greenhouse gas emission and $SF_6$ alternatives were considered in reduction potential. Import of magnesium ingot was 22,806 ton in 2013, which will be expected to increase to 81,700 ton with 20% rate in 2020. Magnesium ingot was consumed to produce magnesium alloy in diecasting process. Recently, commercial production of crown magnesium and magensium plate began. Based on ingot consumption, $CO_2$ emission of domestic magnesium industry was estimated to 504,000 ton, which is about 0.79% of domestic industrial emissions. Reduction potential of diecasting process was estimated to 489,320 ton by changing SF6 to alternative gases such as HFC-134a, Novec-612. Emission factor of Tier 3 level should be developed to enhance the accuracy of greeenhouse gas emission of magnesium industry.