• Korean Chemical Engineering Research
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• v.54 no.4
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• pp.560-567
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• 2016

In this study, we characterized steam reforming reactions and surface of $Ni/Al_2O_3$ catalysts. Ni-Mo based catalysts were prepared by loading Mo as the co-catalyst and reaction activities of the Ni-Mo based catalysts were compared with those of Ni-based catalysts. Through the $H_2$-TPR and XPS analysis it was confirmed that this characteristic efficiency. $O_2$-TPO analysis was performed to examine the deposition characteristics, bonding structures and evaporation characteristics of carbon deposited on the surface of catalysts after long run experiments were performed for steam reforming reactions. As the results, it was found that durability was improved in Ni-Mo based catalysts inhibiting formation of graphitic carbon species which reduced reaction activities of the catalysts by strongly interacting with Ni in the steam reforming reaction.

• Applied Chemistry for Engineering
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• v.20 no.5
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• pp.522-526
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• 2009

The catalytic oxidation of 1,2-dichloribenzene (1,2-DCB) and simultaneous catalytic reduction of nitrogen oxides over the single catalyst has been investigated over various metals (Ru, Mn, Co and Fe) supported on $Al_2O_3$ and $CeO_{2}$. The activity of the different catalysts for catalytic oxidation of 1,2-dichloribenzene depended on the used metal, Ru/Co/$Al_2O_3$, Mn-Fe/CeO2 and Cr/$Al_2O_3$ (commercial catalysts) being the most actives ones. In the catalytic oxidation of chlorobenzene (CB), Ru/Co/$Al_2O_3$ is better than Pt-Pd/$Al_2O_3$, which is the well-known catalyst good for VOC oxidation. Furthermore, it has a good durability on the deactivation by $Cl_2$ and sulfur. For nitrogen oxides (NOx) removal, NOx conversion was 70% at $260^{\circ}C$.

• Fire Science and Engineering
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• v.21 no.1 s.65
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• pp.69-73
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• 2007

In this research, an environmental-friendly foam extinguisher was newly developed using a natural surfactant as its composition. Two criteria were applied to verify its extinguishing performance and environmental attraction. One is unit 2 model by "Standards of Model Approval and Inspection Technology for Portable Fire Extinguishers" presented in Korea Fire Equipment Inspection Corporation. The other is Terrestrial Plants, Growth Test and Fish, Acute Toxicity Test presented in Korea Institute of Toxicology(Korea Research Institute of Chemical Technology). Test results showed that the extinguishing performance was 5 unit of general fire Class A, the $LC_{50}$ by germination was 75(g/kg) and the $EC_{50}$ by growth was 62(g/kg) through Terrestrial Plants, Growth Test, and also the toxicity was 6658 ppm in Fish, Acute Toxicity Test. The numerical values were highly evaluated than other fire extinguishing agents being commercialized in domestic. The results also showed suitably in basic physical properties and anti-corrosion properties for making use of fire extinguishing agent.

• Applied Chemistry for Engineering
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• v.27 no.6
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• pp.590-598
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• 2016

In this study, the adsorption behavior from aqueous solution as well as kinetic and thermodynamic parameters of Acid Black 1 were investigated through batch reaction using coconut shell based granular steam activated carbon. The effects of various adsorption parameters such as pH, initial concentration, contact time, temperature were studied. To confirm the effect of pH, pHpzc measurements were analyzed followed by measuring removal efficiencies of Acid Black 1 at the pH range from 3 to 11. Experimental equilibrium adsorption data were fitted using Langmuir, Freundlich, Temkin and Dubinin-Radushkevich adsorption isotherm. The conformity of adsorption reaction for pseudo first and second order model were evaluated through kinetic analysis. Values of enthalpy change and activation energy were also investigated through thermodynamic analysis and it was confirmed that the adsorption process was endothermic. The spontaneity of adsorption process was evaluated using the values of entropy and Gibbs free energy changes.

• Applied Chemistry for Engineering
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• v.23 no.2
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• pp.190-194
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• 2012

10 wt% Mn supported on various commercial $TiO_2$ catalysts were prepared by wet-impregnation method for the low temperature selective catalytic reduction (SCR) of NO with $NH_3$. A combination of various physico-chemical techniques such as BET, XRD, XPS and TPR were used to characterize these catalysts. MnOx surface densities on MnOx/$TiO_2$ catalyst were related to surface area. As MnOx surface density lowered with high dispersion, the SCR activity for low temperature was increased and the reduction temperature ($MnO_2$ ${\rightarrow}$ $Mn_2O_3$) of surface MnOx was lower. For a high SCR, MnOx could be supported on a high surface area of $TiO_2$ and should be existed a high dispersion of non-crystalline species.

• Applied Chemistry for Engineering
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• v.22 no.4
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• pp.400-404
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• 2011

The activity and stability of the metal filter material Pt coated on NOx and soot oxidation were examined. The catalytic reaction test for NOx and soot were also performed independently and simultaneously. As a result, it showed the NO to $NO_2$ shift reaction with 20% conversion, NOx decomposition (about 10%) and perfect soot oxidation on the material Pt coated proceeded. Onset temperature of soot oxidation shift to lower temperature (about $30^{\circ}C$) by generated $NO_2$. The material also was less affected by thermal shock than $Pt/Al_2O_3$ or $Pt/TiO_3$ catalysts due to its stability of surface structure.

• Applied Chemistry for Engineering
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• v.33 no.1
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• pp.64-70
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• 2022

In this study, an experiment was performed by adding Sb during NH3-selective catalytic reduction (NH₃-SCR) while varying calcination temperatures from 400 to 700 ℃ to improve the low temperature denitrification efficiency of VWTi catalyst. As a result, VWSbTi(500) and VWSbTi(600) catalysts corresponding to Sb calcination temperatures of 500~600 ℃ showed the best denitrification performance at low temperatures below 300 ℃. BET, XRD, Raman, XPS, H₂-TPR, and NH₃-TPD analyses were performed In order to confirm physicochemical properties according to the calcination temperature. In the case of VWSbTi(500) and VWSbTi(600), an acid site increased with the generation of W=O species, and superb activity at low temperatures was exhibited due to the excellent redox characteristics and increase in electron density of tungsten. Furthermore, in the case of VWSbTi(700), as the crystalline V₂O₅ structure was formed, the denitrification efficiency decreased. Thus the optimum calcination temperature during Sb addition process was confirmed.

• Korean Journal of Food Science and Technology
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• v.43 no.2
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• pp.206-212
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• 2011

Makgeolli is Korean traditional alcoholic beverage that has historically been brewed. In this study, we analyzed the profile of organic acids in makgeolli and also evaluated its physiological characteristics. Makgeolli contained excess lactic acid, which is produced by lactic acid bacteria (LAB). Anti-obesity effects of makgeolli were investigated in 3T3-L1 preadipocytes. Compared to the negative control, makgeolli inhibited the differentiation of preadipocyte as quantified by Oil red O dye. In particular, $100{\mu}g/mL$ makgeolli reduced 40 to 70% of differentiation. To evaluate the anti-angiogenic and anti-inflammatory effects of makgeolli, we performed chorioallantoic membrane assay and measured nitric oxide production from lipopolysaccharide-induced RAW264.7 cells. Most makgeolli interrupted the formation of neo-vasculature and significantly inhibited NO production in a dose-dependent manner. Taken together, these findings suggest that commercial makgeolli has inhibitory activities against adipogenesis, neo-vascularization, and inflammation, and also they are influenced by second metabolites from nuruk microflora containing fungi and LAB.

• Korean journal of applied entomology
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• v.34 no.3
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• pp.181-190
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• 1995

Malate dehydrogenase in the mosquito ovary after a blood meal, Aedes aegypti, was purified and characterized. MDH purification steps involved DEAE-Sepharose, S-Sepharose and Cibacron blue affinity chromatography. The purified MDH was 70,000 daltons in molecular weight and was a homodimer consisting of tow identical subunits. Optimal activity of purified MDH was obtained pH 9.0-9.2 in malate-oxaloacetate reaction and pH 9.8-10.2, in oxaloactate-malate reaction. With obtained pH 9.0-92 in malate-oxaloacetate reaction and pH 9.8-10.2, in oxaloactate-malate reaction. With malate as substrate, purified mitochondrial MDH (1.28$\times$${10}^{-4}$ M) had lower Km value than cytoplasmic MDH (8.92x${10}^{-3}$ M). MDH activity was inhibited by citrate, $\alpha$-ketoglutarate, and ATP. Inhibition of MDH activity by ATP and citrate was less in malate-oxaloacetate reaction and in oxaloacetate-malate reaction. MDH activity was completely inhibited by ATP in oxaloacetate-malate reaction and not inhibited by citrate in malate-oxaloacetate reaction. Temporal activity change of MDH is similar to that of isocitrate dehydrogenase in the ovary after blood feeding; their activities in the ovary began to rise at 18 hours after a blood meal, and reached at the maximal level at 48 hours.

• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.4
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• pp.550-555
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• 2013

Extrinsic skin aging is characterized by the loss of skin tone and resilience, irregular pigmentation, and deep wrinkles. The aim of this study was to investigate the effects of Ehwa Makgeolli containing oriental herbs (Glycyrrhiza uralensis Fisch., Lycium chinense MILL., Morus alba L., and Saururus chinensis Baill) on skin whitening and wrinkling in human skin cells. We prepared Makgeolli extracts (HEE) with 70% ethanol. HEE significantly inhibited in vitro mushroom tyrosinase activity and reduced the cellular and secreted melanin content of mouse melanoma melanocytes (B16F1 cells). HEE down-regulated the protein expression of tyrosinase related protein (TRP)-1/-2, a key player in melanogenesis. Treatment with HEE in human keratinoctyes (HaCaT cells) inhibited the proteolytic activities of matrix metalloproteinase (MMP)-2/-9 in a dose-dependent manner and dramatically reduced the expression of MMP-2/-9. In addition, HEE attenuated lipopolysaccharide (LPS)-induced nitric oxide production in murine macrophages (RAW264.7 cells). These results indicate that HEE may be a great cosmeceutical ingredient for its whitening, anti-wrinkle, and anti-inflammatory effects.