• Korean Journal of Materials Research
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• v.29 no.10
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• pp.592-602
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• 2019

Feasibility is investigated for reduction of chromium ore by Si sludge with mixed silicothermic and carbothermic reaction. The reduction behavior of chromium ore using Si sludge is investigated precisely to determine the effects of carbon addition, reaction time, and reaction temperature. The pellets are dropped into the furnace after temperature stabilized. As the amount of C addition increases, the amounts of CO and $CO_2$ gas generation increase. After the dropping of the pellets, the pellets are heated and the reaction starts at about 1,573 K or higher. The pellets maintain their shape until 10 min after the drop, and then melted. As the holding time increased, the size of the reduced metal particles increased. The chromium ore is rapidly reduced by the Si sludge, and the slag penetrated into the chromium ore and reduction progressed inside. As the reduction temperature increased, the reaction initiation time is shortened and the reaction fraction of the reduction reaction increased. As the reaction temperature increased, agglomeration of reduced ferrochrome metal is promoted.

• KEPCO Journal on Electric Power and Energy
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• v.2 no.1
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• pp.103-108
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• 2016

Carbon Capture and Storage technologies are recognized as key solution to meet greenhouse gas emission standards to avoid climate change. Although MEA (monoethanolamine) is an effective amine solvent in $CO_2$ capture process, the application is limited by high energy consumption, i.e., reduction of 10% of efficiency of coal-fired power plants. Therefore the development of new solvent and improvement of $CO_2$ capture process are positively necessary. In this study, improvement of $CO_2$ capture process was investigated and applied to Test Bed for reducing energy consumption. Previously reported technologies were examined and prospective methods were determined by simulation. Among the prospective methods, four applicable methods were selected for applying to 0.1 MW Test Bed, such as change of packing material in absorption column, installing the Intercooling System to absorption column, installing Rich Amine Heater and remodeling of Amines Heat Exchanger. After the improvement construction of 0.1 MW Test Bed, the effects of each suggested method were evaluated by experimental results.

• Proceedings of the KSME Conference
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• 2003.11a
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• pp.284-289
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• 2003

The narrow band-averaged transmissivity of $CO_2-H_2O$ mixtures is expressed by multiplying the transmissivities of $CO_2$ and $H_2O$. Applying the multiplication property of narrow band transmissivities for gas mixtures of $CO_2-H_2O$, the number of gray gases, required for accurate representation of the absorption characteristics by using the narrow band based WSGGM, is significantly increased. To reduce the computational loads by reducing the number of gray gases, we propose a gray gas regrouping process where the gray gases used for the WSGGM are regrouped into a specified number of groups according to the magnitudes of absorption coefficients. To evaluate the proposed WSGGM for gas mixtures, the radiative transfer problems through three-dimensional gas media are considered. The radiative source terms and the radiative heat fluxes obtained by using the proposed method are fairly well compared to those obtained by using the SNB model. The regrouping technique results in an excellent computational efficiency with minor loss of accuracy.

• Journal of Korean Society for Atmospheric Environment
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• v.27 no.4
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• pp.443-453
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• 2011

Real-time Traffic Information Service could play a key role in reducing incomplete combustion time remarkably since it can provide traffic information in real-time basis. Emission characteristics of test engines were studied in terms of travel distance and speed. The present study focused on a north district in Daegu, 12 km. The driving for the emission test was done at 8AM, 3PM, 7PM which represents various traffic conditions. The reduced emissions of Greenhouse Gases (GHG) have been measured for a travel distance running at different loads (conventional shortest route and Real-time Traffic Information) and GHG ($CO_2$, $CH_4$, $N_2O$) are all inventoried and calculated in terms of existing emission factors. The emission of GHG has been shown to reduce linearly with travel distance: $CO_2$ (9.15%), $CH_4$ (18.43%), $N_2O$(18.62%).

• Journal of Physiology & Pathology in Korean Medicine
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• v.34 no.3
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• pp.136-141
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• 2020

The purpose of this study was to investigate the action mechanism of the roots of Adenophora triphylla var. japonica extract (ATE) in 3T3-L1 adipocytes. Cell toxicity test by MTT assay and lipid accumulation was performed to evaluate the inhibitory effect on the differentiation of adipocyte from preadipocytes induced by MDI differentiation medium, while adipogenesis related proteins expression level were evaluated by western blotting. As a result, ATE inhibited MDI-induced adipocyte differentiation in 3T3-L1 cells dose-dependently without cytotoxicity. Our results showed that ATE inhibited the phosphorylation of IRS1, thereby decreasing the expression of PI3K110α and reducing the phosphorylation of AKT and mTOR, resulting in attenuated protein expression of C/EBPα, PPARγ, ap2 and FAS in 3T3-L1 cells. These results suggest anti-adipogenic functions for ATE, and identified IRS1 as a novel target for ATE in adipogenesis.

• Microbiology and Biotechnology Letters
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• v.24 no.2
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• pp.217-221
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• 1996

Various treatments of naked barley with commercial liquefying enzymes have been emploved to reduce high viscosity of naked barley in cooking as a raw material for alcohol production and to increase alcohol yield. The enzyme BAN used for cooking and liquefaction of naked barley was able to make a reduction of one third of viscosity and to enhance alcohol yield of 4 l/Ton of raw material than the T120L was. Of course, alcohol yield depended in part on the applied saccharifying enzymes. The low temperature cooking of naked barley with BAN was favorable compared with high temperature cooking for both of reducing viscosity (210 vs. 237 cp) and final alcohol yield (Yp/so: 0.397 vs. 0.395 g/g) in industrial scale.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.14 no.1
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• pp.1-15
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• 1988

A new method for liquid chromatography with post column reaction is suggested for the separation and quantification of tertiary amines. A mixture of triethanolamine and N-ethyl diethanolamine was separated by a strong cation exchange column, followed by spectrophtometric detection of the blue colors generated from the reaction of each amine with the Folin-Ciocalteau reagent. The tertiary amines were properly separated when an eluent of pH 9.5 containing 0.5M sodium nitrate was used. Under this condition, calibration curve of triethanolamine in 2-10mg/100ml concentration range was attained. Good results were obtained when cream and shampoo preparations containing known amount of triethanolamine were analysed according to this method. In case the sample did not contain any other interfering reducing substances, the amine was quantitatively determined by the simple reaction of the samples with Folin-Ciocalteau reagent, and the subsequent spectrophotometric measurement.

• Journal of the Korean Electrochemical Society
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• v.21 no.1
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• pp.1-5
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• 2018

In this study, boron - doped carbon was prepared by reducing carbon dioxide ($CO_2$) at high temperature by using sodium borohydride ($NaBH_4$). The boron - doped carbon was coated on carbon felt and applied as an electrode for a vanadium redox battery cell. As a result of electrochemical performance evaluation, reversibility of carbon felt coated with boron doped carbon compared to pure carbon felt was improved by about 20% and charge transfer resistance was reduced by 60%. In the charge / discharge results, energy density and energy efficiency were improved by 21% and 12.4%, respectively. These results show that carbon produced by reduction of $CO_2$ can be used as electrode material for redox flow battery.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.10
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• pp.6439-6444
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• 2015

With increasing concern about global warming, CCS (Carbon dioxide capture and storage) has attracted much attention as a promising technology for reducing $CO_2$ emission. It is necessary to develop the cost-effective absorbents materials in order to rapid commercialize CCS technologies. In this work, he study for the promotion of absorption rate in $CO_2$ capture system using metal nanoparticle were investigated. Three kinds of metal nanoparticle, cobalt, zinc, and nickel, were prepared by wet and dry method and effect of preparation method on the absorption rate of $CO_2$ were compared. Among the tested using pH method, nickel nanoparticle prepared by wet method showed the most significant improvement of $CO_2$ absorption rate. In case that metal nanoparticle is applied to CCS process, it is expected to be more efficient in $CO_2$ capture process due to reduce the size of absorption tower.

• Korean Journal of Materials Research
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• v.30 no.11
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• pp.581-588
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• 2020

Reducing CO₂ into high value fuels and chemicals is considered a great challenge in the 21st century. Efficiently activating CO₂ will lead to an important way to utilize it as a resource. This article reviews the latest progress of g-C₃N₄ based catalysts for CO₂ reduction. The different synthetic methods of g-C₃N₄ are briefly discussed. Article mainly introduces methods of g-C₃N₄ shape control, element doping, and use of oxide compounds to modify g-C₃N₄. Modified g-C₃N₄ has more reactive sites, which can significantly reduce the probability of photogenerated electron hole recombination and improve the performance of photocatalytic CO₂ reduction. Considering the literature, the hydrothermal method is widely used because of its simple equipment and process and easy control of reaction conditions. It is foreseeable that hydrothermal technology will continue to innovate and usher in a new period of development. Finally, the prospect of a future reduction of CO₂ by g-C₃N₄-based catalysts is predicted.