• Journal of Industrial and Engineering Chemistry
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• v.67
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• pp.28-51
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• 2018

Graphitic carbon nitride ($g-C_3N_4$) as a fascinating visible light active semiconductor photocatalyst has medium band gap, non-toxic nature, stable chemical structure and high thermal stability. Recently, intensive researches are focused on photocatalytic activity of $g-C_3N_4$ for wastewater treatment. This review demonstrates latest progress in fabrication of graphitic carbon nitride $C_3N_4$ incorporated nanocomposite to explore photocatalytic ability for water purification. The $g-C_3N_4$-based nanocomposites were categorized as $g-C_3N_4$ metal-free nanocomposite, noble metals/$g-C_3N_4$ heterojunction, non-metal doped $g-C_3N_4$, transition and post transition metal based $g-C_3N_4$ nanocomposite. Apart from fabrication methods, we emphasized on elaborating the mechanism of activity enhancement during photocatalytic process.

• Proceedings of the Korean Magnestics Society Conference
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• 2009.05a
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• pp.97-98
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• 2009

• Proceedings of the Korean Magnestics Society Conference
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• 2012.11a
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• pp.67-68
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• 2012

• Bulletin of the Korean Chemical Society
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• v.32 no.9
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• pp.3327-3332
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• 2011

Antimicrobial peptides have recently gained the much attention because of their ability to make defense system from attacking bacterial infections. Drosocin has been considered as very attractive antibiotic agents because of low toxicity against human erythrocytes and active at the low concentration. We have studied the structureactivity relationship of a glycopeptide drosocin focused on the N-acetyl-D-galactoside at $Thr^{11}$ residue. Based on the radial diffusion assay, we found that the acetylation of carbohydrate moiety increased the antimicrobial activity and the $Pro^{10}$, present in the middle of drosocin plays an important role in the antimicrobial activity. Our results provide a good lead compound for further studies on the design of drosocin-based analogues targeting glyco linked Thr site.

• Journal of Electrochemical Science and Technology
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• v.13 no.1
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• pp.54-62
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• 2022

The preparation of low-cost, simple, and scalable electrodes is crucial for the commercialization of water electrolyzers for H₂ production. Herein, we demonstrate the fabrication of cathodes through Mo-modified Zn phosphating of Ni foam (NiF) for water electrolysis, which has been largely utilized in surface coating industry. In situ growth of electrocatalytically active layers in the hydrogen evolution reaction (HER) was occurred after 1 min of phosphating to form ZnNiMoP_i, and subsequent thermal treatment and electrochemical activation resulted in the formation of ZnNiMoPO_xH_y. ZnNiMoPO_xH_y exhibited superior HER performance than NiF, primarily because of the increased electrochemically active surface area of ZnNiMoPO_xH_y compared to that of bare NiF. Although further investigations to improve the intrinsic electrochemical activity toward the HER and detailed mechanistic studies are required, these results suggest that phosphating is a promising coating method and will possibly advance the fabrication procedure of electrodes for water electrolyzers with better practical applications.

• Korean Journal of Materials Research
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• v.7 no.4
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• pp.310-316
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• 1997

The effects of carbide and matrix structures on the abrasion wear resistance of multi-component white cast irons with 3.0 mass%C have been studied in this paper. Four different heats were poured in order to obtain the specimens with different combinations of the carbide structures: a basic iron(3.0 mass%C-5.0 mass%Cr-5.0 mass%V-5.0 mass% Mo-12.5mass%W)for M$_{6}$C and M$_{7}$C$_{3}$ carbides, and a Cr free iron(3.0 mass%C-5.0 mass%V-2.5mass%Mo-12.5 mass%W) for MC and M6C carbides. A conventional high Cr free free iron(3.0 mass%C-5.0 mass%V-2.5 mass%Mo-12.5 mass%W) for MC and M6C carbides. A conventional high Cr white cast iron was also poured to compare its wear resistance with those of the multi-component white cast irons. In the as-cast condition, the range of abrasive wear rate(Rw=mg/min) was from 4.15 to 5.98 . The lowest Rw, which means the highest wear resistance, was obtained in the basic iron with nodular MC, lamellar M$_{2}$C and cellular M$_{7}$C$_{3}$ carbides. On the other hand, the Rw of the high Cr white cast iron ranked between the basic iron and the Mo and W free iron. In each alloy, the Rw of air hardened or tempered specimen was lower than that of the as-cast one because of the change of matrix structures by the heat treatments. The Rw of the hear treated speci-mens increased in the order Mo and W free iron, basic iron, Cr free iron, high Cr iron, and V free iron.n.n.n.

• Proceedings of the Korean Vacuum Society Conference
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• 2016.02a
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• pp.408.2-409
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• 2016

Theoretically, the dye-sensitized solar cells (DSSCs) are high efficiency solar cells. However DSSCs have low power conversion efficiency (PCE) than silicon based solar cells. In this study, we use the phosphor materials, such as $Y_2O_3:Eu$ (Red), $Zn_2SiO_4:Mn$ (Green), $BaMgAl_{14}O_{23}:Eu$ (Blue), to enhance the PCE of DSSCs. Three phosphors were prepared and used as an effective scattering layer on the transparent $TiO_2$ with doctor blade method. We confirmed that the three scattering layers improve the PCE and Jsc due to the light harvesting enhancement via increased the scattering and absorbance in visible range. Under the sun illumination AM 1.5 conditions, the PCE of the mesoporous $TiO_2$ based DSSCs is 5.18 %. The PCE of the DSSCs with Y2O3:Eu, $Zn_2SiO_4:Mn$ and $BaMgAl_{14}O_{23}:Eu$ as scattering layer were enhanced to 5.66 %, 5.72% and 5.82%, respectably. In order to compare the optical properties change, DSSCs were measured by EQE, reflectance and PCE. At the same time, FE-SEM and XRD were used to confirm the structural changes of each layer.

• Journal of the Korean GEO-environmental Society
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• v.15 no.11
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• pp.13-19
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• 2014

Permeable reactive barrier has been recognized as the one of representative methods for remediation of contaminated groundwater. Reactive barrier system containing two and more reactive materials can remove multiple contaminants such as nutritive salts and heavy metals. In this study, removal efficiency of multiple contaminants was evaluated when both zeolite and basic oxygen furnace slag were used as reactive materials. Sequential batch test which consists of two materials was performed to evaluate removal efficiency comparing the reaction order of them against nutritive slats including ammonium and phosphate and heavy metal including cadmium. As a result, zeolite-basic oxygen furnace slag sequence batch test showed the best efficiency for removal of multiple contaminants including nutritive salts and heavy metal.

• Applied Microscopy
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• v.38 no.3
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• pp.185-193
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• 2008

An experimental comparison of the detection properties between imaging plate and film for recording the electron diffraction pattern was carried out on a radiation-sensitive material, an aluminum trihydroxide(gibbsite, ${\gamma}-Al(OH)_3$), through the electron beam irradiation. Because the imaging plate has a wide dynamic range sufficient for recording extremely low- and high-electron intensities, the range of spatial frequency for the diffraction pattern acquired by the imaging plate was extended to two times larger than the range by the film, especially at a low electron dose condition(${\leq}0.1\;e^-/{\mu}m^2$). It is also demonstrated that the imaging plate showed better resolving power for discriminating fine intensity levels even in saturated transmitted beam. Hence, in the respect of investigating the structures of radiation-sensitive materials and cryo-biological specimens, our experimental demonstrations suggest that the imaging plate technique may be a good choice for those studies, which have to use an extremely low electron intensity for recording.

• Proceedings of the Korean Magnestics Society Conference
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• 2003.12a
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• pp.229-229
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• 2003