• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.24 no.11
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• pp.920-924
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• 2011

ZnO crystals with belt and comb shapes were synthesized without any catalysts through a simple thermal oxidation of ZnS powder in alumina crucible under air atmosphere. X-ray diffraction (XRD) pattern revealed that the ZnO crystals had wurtzite structure of hexagonal phase. Energy dispersive x-ray (EDX) spectra showed that the ZnO was of high purity. In the cathodoluminescece spectra obtained for the ZnO crystals with belt and comb shapes, a strong ultraviolet emission centered at 380nm was observed, which indicates the ZnO crystal has high crystalline quality.

• Journal of Electrochemical Science and Technology
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• v.11 no.2
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• pp.165-171
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• 2020

The electrochemical preparation and spectroscopic characterisation of iridium-antimony (Ir-Sb) species is important owing to their potential applications as nanostructure materials. Nanostructures, i.e. nanoflower and nanodisk, of Ir-Sb were electrodeposited on conductive substrates using a practical electrochemical method based on the simultaneous underpotential deposition (UPD) of Ir and Sb from the IrCl₃ and Sb₂O₃ at a constant potential. Electrochemical UPD mechanism of Ir-Sb was studied using cyclic voltammetry and potential-controlled electrochemical deposition techniques. Herein, X-ray diffraction, scanning electron microscopy, energy dispersive spectroscopy, X-ray photoelectron and Raman spectroscopy were used to determine the morphological and structural properties of the electrochemically-synthesised Ir-Sb nanostructures.

• Journal of the Korean Ceramic Society
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• v.48 no.2
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• pp.147-151
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• 2011

In this study, we prepared graphene by using the modified Hummers-Offeman method and then introduced the metals (Pt, Pd and Fe) for dispersion on the surface of the graphene for synthesis of metal-graphene composites. The characterization of the prepared graphene and metal-graphene composites was performed by X-ray diffraction (XRD), scanning electron microscopy (SEM) with energy dispersive X-ray (EDX) analysis and transmission electron microscopy (TEM). According to the results, it can be observed that the prepared graphene consists of thin stacked flakes of shapes having a well-defined multilayered structure at the edge. And the metal particles are dispersed uniformly on the surface of the graphene with an average particle size of 20 nm.

• Journal of the Korean Ceramic Society
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• v.47 no.4
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• pp.269-275
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• 2010

In this study, we successfully prepared CNT/$TiO_2$, Pt/CNT and Pt/CNT/$TiO_2$ composites and investigated their photocatalytic activity in MB solution by irradiation under UV light. Fourier transform infrared (FT-IR) spectroscopy was used to characterize the functional group on the surface of MWCNTs, which oxidized by MCPBA. Brunauer-Emmett-Teller (BET) surface area, transmission electron microscopy (TEM), X-ray diffraction (XRD) and energy dispersive X-ray (EDX) were used to analyze the prepared composites. The results of the decomposition of the MB solution indicated that the Pt/CNT/$TiO_2$ composite had the best photocatalytic activity among the three kinds of composites.

• Journal of the Korean Society of Costume
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• v.58 no.5
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• pp.211-231
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• 2008

To conserve historic textiles, analyses of textile materials, pollutants and deterioration are prerequisite steps. Based upon analytical results, guides for conservation of historic textiles are established. In analyses of textile materials, pollutants and deterioration, there are chemical methods(burning, solubility and staining), physical methods(microscopy and density) and instrumental analysis(Fourier Transform Infrared Spectroscopy (FT-IR), Fourier Transform Raman Spectroscopy(FT-Raman), Gas Chromatography(GC), Mass Spectroscopy(MS), X-Ray Fluorescence (EDXRF, WDXRF), Energy Dispersive Spectroscopy(EDS), and X-Ray Diffraction(XRD), Tensile Testing Machine etc.). Combination of qualitative and quantitative analyses makes accurate diagnosis of textile condition possible. As examples of analyses and conservation of historic textiles, Chuninsan(19 century) similar to sunshade with handing down historic textile and golden decorative skirt(17 century) with excavated costume are taken.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2015.11a
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• pp.303-303
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• 2015

In order to investigate ion release and biocompatibility of Ti-6Al-4V dental alloy by electrochemical corrosion test and MTT assay, commercial Ti-6Al-4V alloy rod (99.99% Ti, USA, Co) were used in the study. The microstructure of the alloys was examined by optical microscopy (OM), Field emission scanning electron microscopy (FE-SEM), energy dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), MTT assay, and corrosion test. From the polarization curves, very low current densities were obtained for Ti-6Al-4V alloys, indicating a formation of stable passive layer.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2015.11a
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• pp.195-195
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• 2015

본 연구에서는 인산-망간 피막처리 공정 중에 생성되는 슬러지를 방지하기 위하여 인산-망간 화성처리액에 유기첨가제인 Tartaric acid를 첨가하여 내마모성 및 방청성 향상을 목적으로 슬러지를 방지하기 위한 인산-망간 화성피막의 특성을 연구하였다. Tartaric acid의 농도에 따른 표면 Morphology를 Scanning Electron Microscope (SEM)과 Energy Dispersive X-ray spectroscopy (EDS)을 이용하여 분석하였으며, EDS 분석을 통해 Mn, P, Fe, O, C의 성분을 확인 할 수 있었으며, 인산-망간 화성피막의 상(phase)을 확인하기 위하여 X-ray diffraction (XRD)을 분석을 통하여 $(Mn,Fe)_5H_2(PO_4)_44H_2O$으로 구성된 인산-망간 화성피막을 확인할 수 있었다. 또한 Tartaric acid의 농도에 따른 인산-망간 피막의 내마모 시험(Ball on disc) 및 경도시험을 실시하여 기계적인 특성 및 슬러지의 양에 대하여 분석하였다.

• Journal of the Korean institute of surface engineering
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• v.53 no.2
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• pp.53-58
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• 2020

In this study, we developed plasma electrolytic oxidation (PEO) process for aluminum 7075 alloy to improve the corrosion and mechanical properties. The electrolyte consists of potassium hydroxide and sodium silicate. Additionally, sodium stannate was added into the electrolyte to investigate its effect on PEO film formation. Titanium was used as the counter electrode. Plasma generation voltage reduced from 300V to 150 V by adding 4 g/L of sodium stannate. The thin oxide films were observed by SEM(Scanning Electron Microscopy)/EDS (Energy Dispersive Spectroscopy) for quantitative and qualitative analyses. XRD (X-ray diffraction) and XRF (X-ray Fluorescences) analyses were also carried out to identify oxide layer on aluminum 7075 surface. Vicker's hardness test was performed on the PEO-treated aluminum 7075 surface.

• Journal of Microbiology and Biotechnology
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• v.27 no.7
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• pp.1331-1335
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• 2017

In this study, the feasibility of introducing calcite-forming bacteria into concrete pavements to improve their mechanical performance was investigated. Lysinibacillus sphaericus WJ-8, which was isolated in a previous study and is capable of exhibiting high urease activity and calcite production, was used. When analyzed via scanning electron microscopy (SEM) and X-ray diffraction, WJ-8 showed a significant amount of calcite precipitation. The compressive strength of cement mortar mixed with WJ-8 cells and nutrient medium (urea with calcium lactate) increased by 10% compared with that of the controls. Energy dispersive x-ray spectroscopy analyses confirmed that the increase in strength was due to the calcite formed by the WJ-8 cells.

• Journal of the Korean Ceramic Society
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• v.48 no.3
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• pp.211-216
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• 2011

Nickel oxide-doped ACF and $TiO_2$ composites (NiO/ACF/$TiO_2$) were prepared by a sol-gel method. The composite obtained was characterized by BET surface area measurements, X-ray diffraction, transmission electron microscopy and energy dispersive X-ray analysis. A methylene blue (MB) solution under visible light irradiation was used to determine their photocatalytic activity. Excellent photocatalytic degradation of the MB solution was observed using the $TiO_2$, Ti-ACF and NiO/ACF/$TiO_2$ composite under visible light.