• 한국정보디스플레이학회:학술대회논문집
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• 2004.08a
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• pp.495-498
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• 2004

PDP use the mixture of inert gases to generate a discharge inside display pixels. Inside of PDP, there exist highly reactive conditions in the gap between two glass panels. MgO layer and phosphor have been investigated as a function of discharge and thermal process. Impurities such as CO, $CO_2$, OH and $H_2O$ in discharge region may deteriorate the characteristics of PDP operation during life time. Change of impurity generation of various MgO and phosphor surfaces were measured by using x-ray photoelectron spectroscopy(XPS) and quadropole mass spectrometer (QMS). Carbon containing species such as C, CO and $CO_2$ were drastically increased on the surfaces during discharge and thermal treatment. Carbon impurities on the MgO and phosphor are the dominant factor for their instability.

• 한국신재생에너지학회:학술대회논문집
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• 2011.05a
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• pp.214.1-214.1
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• 2011

In this work, the electrochemical properties of the surface treated multi-walled carbon nanotubes (MWNTs) are investigated for supercapacitors. Nitrogen- and oxygen functional groups containing MWNTs are prepared by nitrogen precursors and acidic treatment, respectively. The surface properties of the MWNTs are confirmed by X-ray photoelectron spectroscopy (XPS) and Zeta-potential measurements. The electrochemical properties of the MWNTs are investigated by cyclic voltammetry, impedance spectra, and charge-discharge cycling performance in 1 M $H_2SO_4$ at room temperature. As a result, these functionalized MWNTs lead to an increase in the specific capacitance as compared with the pristine MWNTs. It proposes that the pyridinic and pyridinic-N-oxides nitrogen species influence on the specific capacitance due to their positive charges, and thus an improved electron transfer at high current loads, since they are the most important functional groups affecting capacitive behaviors.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.11a
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• pp.122-123
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• 2005

단층벽 탄소나노튜브(Single-walled carbon nanotube)를 성장시키고 성장된 탄소나노튜브를 여러 단계의 여과과정이 필요 없는 단순한 정제과정을 통하여 비정질 탄소 찌꺼기, 촉매 금속 등의 불순물을 제거하였다. 성장 온도가 증가함에 따라 수율이 증가하고 불순물의 함유량이 적은 탄소나노튜브가 성장이 되었으며 전반적으로 0.41-2.0 nm의 균일한 직경을 가진 SWNT가 합성이 되었으며 정제 후 96% 이상의 순도를 가진 SWNT를 얻을 수 있었다. 전반적으로 실험결과에 대한 물질의 특성 은 field emission scanning electron microscopy (FESEM)와 X-ray diffraction (XRD) 그리고 Raman spectroscopy로 조사하였다.

• 한국신재생에너지학회:학술대회논문집
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• 2009.06a
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• pp.369-372
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• 2009

In the present study, the effect of chemical treatment on graphite nanofibers (GNFs) supports with various concentrated nitric acids was investigated for methanol oxidation. To optimize the electrocatalytic activity, PtRu catalysts were deposited on GNF supports by impregnation method. The surface and structural properties of the GNF supports were characterized by X-ray photoelectron spectroscopy (XPS), element analyzer (EA), and X-ray diffraction (XRD). The morphology of the catalysts was observed by means of transmission electron microscopy (TEM). The electrocatalytic activity of PtRu/GNF catalysts was investigated by cyclic voltammetry measurement. As a result, the oxygen functional groups were introduced on the GNF supports and were gradually increased with increasing of concentrated nitric acid, causing the smaller particle size and higher loading level. And the electrocatalytic activity of the catalysts for methanol oxidation was gradually improved. Consequently, it was found that chemical treatments could influence on surface properties of the carbon supports, resulting in enhancing the electrocatalytic activity of the catalysts for DMFCs.

• Corrosion Science and Technology
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• v.21 no.4
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• pp.250-257
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• 2022

Transition metal sulfide materials have emerged as a new anode material for Li secondary batteries owing to their high capacity and rate capability facilitated by fast Li-ion transport through the layered structure. Among these materials, niobium disulfide (NbS₂) has attracted much attention with its high electrical conductivity and high theoretical capacity (683 mAh g^-1). In this study, we propose a facile synthesis of Fe_xNbS₂/C composite via simple ball milling and heat treatment. The starting materials of FeS and Nb were reacted in the first milling step and transformed into an Fe-Nb-S composite. In the second milling step, activated carbon was incorporated and the sulfide was crystallized into Fe_xNbS₂ by heat treatment. The prepared materials were characterized by X-ray diffraction, electron spectroscopies, and X-ray photoelectron spectroscopy. The electrochemical test results reveal that the synthesized Fe_xNbS₂/C composite electrode demonstrates a high reversible capacity of more than 600 mAh g^-1, stable cycling stability, and excellent rate performance for Li-ion battery anodes.

• Journal of Korean Society on Water Environment
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• v.20 no.3
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• pp.241-244
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• 2004

Radiation treatment with gamma-rays and electron-beams was used to remove polyvinyl alcohol(PVA), one of the main components of dyeing wastewater. PVA was effectively decomposed by radiation treatment, thus the removal was near 100 % at an initial PVA concentration of 44 mg/L. However, total organic carbon(TOC) removal was less than 5 % due to lower transformation of PVA to $CO_2$. This directly indicates the radiation treatment alone is not appropriate for the complete decomposition of PVA. In this sense, the improvement of biodegradability($BOD_5/COD$) of PVA by radiation treatment was studied. Both gamma-ray and electron-beam treatments significantly increased the biodegradability of PVA by transforming non-biodegradable PVA to biodegradable by-products. This suggests radiation treatment, especially electron-beam treatment that showed better improvement of biodegradability, can be used as a pre-treatment of biological degradation process of PVA.

• Korean Journal of Metals and Materials
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• v.50 no.7
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• pp.545-548
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• 2012

The optical and electronic properties of Indium Tin Oxide (ITO) thin films deposited on a RF-plasma treated glass substrate were investigated by X-Ray Photoelectron Spectroscopy (XPS), Ultra-violet Photoelectron Spectroscopy (UPS), Reflected Electron Energy Loss Spectroscopy (REELS). The modification of glass substrates was carried out by varying the time of the plasma surface treatment in an oxygen atmosphere. The focus of this research was to examine how the optical and electronic properties of ITO thin films change with the plasma treatment time. The surface energy increased since the carbon bonds were removed from the surface after the glass substrate received the surface treatment. The ITO thin films produced on the glass substrate with surface treatment showed that the high optical transmittance was approximately 85%. The measured band gap energy was as high as 3.23 eV when the plasma treatment time was 60 s and the work function after the treatment was increased by 0.5 eV in comparison to that before the treatment of 60 s. The ITO thin film exhibited an excellent sheet resistance of $2.79{\Omega}/{\Box}$. We found that the optical and electronic properties of ITO thin films can be improved by RF-plasma surface treatment.

• Carbon letters
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• v.12 no.3
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• pp.143-151
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• 2011

Bagasse fly ash (BFA) is one of the important wastes generated in the sugar industry; it has been studied as a prospective low-cost adsorbent in the removal of congo red (CR) from aqueous solutions. Chemical treatment with $H_2O_2$ was applied in order to modify the adsorbability of the raw BFA. Batch studies were performed to evaluate the influence of various experimental parameters such as dye solution pH, contact time, adsorbent dose, and temperature. Both the adsorbents were characterized by Fourier-transform infrared spectrometer, energy-dispersive X-ray spectrophotometer and nitrogen adsorption at 77 K. Equilibrium isotherms for the adsorption of CR were analyzed by Langmuir, Freundlich and Temkin models using non-linear regression technique. Intraparticle diffusion seems to control the CR removal process. The obtained experimental data can be well described by Langmuir and also followed second order kinetic models. The calculated thermodynamic parameters indicate the feasibility of the adsorption process for the studied adsorbents. The results indicate that BFA can be efficiently used for the treatment of waste water containing dyes.

• Resources Recycling
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• v.10 no.3
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• pp.29-36
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• 2001

Cyclic voltammetry has been applied in the basic studies for the treatment and recovery of heavy metal component contained in wastewater by electrochemical reduction. The electrochemical behaviors of zinc ion for zinc metal electrode and carbon elec-trode were characterized by voltammograms and it was showed that zinc ions were reduced to metallic form below -0.76 V vs SHE. The change in the features of crystalline form of metallic zinc upon oxidation and reduction reaction was observed by X-ray diffraction method and the Am analysis verified that zinc ions were reduced to metal on copper plate. The results of this study were regarded to be important and meaningful in the treatment of heavy metal containing wastewater and, as a result, in the obtainment of metallic product by electrochemical method.

• Applied Chemistry for Engineering
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• v.27 no.6
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• pp.627-632
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• 2016

Ethyl methacrylate (EMA) monomer coupling onto the polyvinylidene fluoride (PVDF) film surface was attempted to enhance the interfacial adhesive force between PVDF-polyvinyl chloride (PVC) bilayer films via dielectric barrier corona discharge. The interfacial forces were quite enhanced when PVDF films were treated by corona discharge in an EMA 1% atmosphere. The contact angle of PVDF films decreased due to corona treatment. X-ray photoelectron spectroscopy (XPS) analysis showed that the carbon and oxygen content of the PVDF film surface increased with corona discharge while the fluoride content decreased. The curve fitting of XPS $C_{1s}$ peaks revealed that the non-polar C-C bonded carbon and oxygen-bonded carbon increased gradually with corona treatment, while the fluorine-bonded carbon decreased.