• The Transactions of the Korean Institute of Electrical Engineers P
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• v.59 no.2
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• pp.232-237
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• 2010

Fault rate of RCD is increasing due to deterioration and long period usage in domestic. According to Korean standards, the RCDs are installed in panel boards. When RCDs are installed at outdoor, the RCDs must be protected from uv, water etc. by using the housing. However, many RCDs are exposed to the external environment. As a results, many RCDs have malfunctions so that cause the electrical accidents. The RCDs manufactured by four makes were used as the sample to weathering test. Futhermore, those were analyzed the ingredients of RCD'S using SEM, EDX and FT-IR/TAR before and after weathering test.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.07a
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• pp.406-409
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• 2001

In this paper, the microstructure and the dielectric properties of the Sr$_{1-x}$ Ca$_{x}$TiO$_3$(0$\leq$$\chi$$\leq$0.2) -based grain boundary layer ceramics were investigated. The specimens were sintered from 142$0^{\circ}C$ to 152$0^{\circ}C$ for 4hr. in $N_2$ gas. The 2nd phase formed by thermal diffusing from the surface lead to a very high apparent dielectric constant, $\varepsilon$$_{r}$>50000. The structural properties of the specimens were studied by X-ray diffraction and SEM, EDX. All specimens exhibited cubic structure. Increasing content of Ca, the peak intensity were decreased.ed.d.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2010.06a
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• pp.110-110
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• 2010

Suspension insulator have made use of porcelain insulator mainly, but polymer insulator is using recently. Polymer suspension insulator have advantage that it is light than porcelain insulator. The ageing performance is excellent and it is possible for mass production. There is high possibility of mountain fire because a lot of potential inflammables such as fallen leaves are stacked on the ground Therefore surface aging of polymer insulator most of the overhead transmission lines in Korea are operated on the mountain need analysis of transmission line into forest fire. surface aging property is analyzed by SEM, EDX, XPS, FTIR, DSC in this paper.

• Fire Science and Engineering
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• v.12 no.4
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• pp.31-40
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• 1998

Very often, whether accidentally or intentionally set fire, according as building are elevated, varied or complicated day by day. It is of primary importance that we have a treatment of fire damaged structure. In general, strength and elasticity modulus of heated concrete are reduced. Product background of cement, sand and coarse aggregate differ from country to country, so that thermal behaviour of concrete make a difference in high temperature. To cope with demand, this paper is a study on relation to microstructure and strength reduction. In consequence of experiments, concrete exposed to high temperature are estimating the reduction of mechanical properties in comparison with microstructure characteristics which are abtained from the SEM/EDX, XRD and DSC-TG analysis of heated specimens under various temperature.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.16 no.3
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• pp.106-111
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• 2006

The objective of this paper is to compare the surface features of two kinds of nano-porous activated carbon fiber (NPACF) treated with potassium and the variation of their properties by phosphoric acid pre-treatment. X-ray diffraction (XRD) patterns indicate that NPACF containing potassium species show better performance for potassium and potassium salts by pre-treatment with phosphoric acid. In order to present the causes of the differences in surface properties and specific surface area after the samples were treated with phosphoric acid, pore structure and surface morphology are investigated by adsorption analysis and SEM. For the chemical composition microanalysis for potassium loading of the NPACF pre-treated with phosphoric acid, samples were analyzed by EDX. Finally, the type and quality of oxygen groups are determined from the method proposed by Boehm.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.57 no.3
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• pp.332-337
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• 2008

We analyzed carbonization pattern and crystal structure of polyvinyl chloride wire by thermal stress. Copper that is oxidized at normal temperature is a reddish brown. If under the thermal stress range of 500 to 700 [$^{\circ}C$], carbonization and exfoliation occurrence. Section structure of electric wire is same as arrangement of particle in metallograph analysis. But, as thermal stress increases, size of particle is enlarged. Electric wire displays elongation structure in SEM image analysis and elongation structure collapses when receive thermal stress at 300 [$^{\circ}C$]. In EDX analysis, we get the spectra of CuL, CuK, OK, and ClK. FT-IR analysis was shown new spectra with in range of $1,440{\sim}1,430\;[cm^{-1}]$, 1,340 [$cm^{-1}$], 1,240 [$cm^{-1}$].

• Journal of Korean Society for Atmospheric Environment
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• v.16 no.6
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• pp.565-572
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• 2000

To quantitatively estimate mass contribution of long-range transported yellow sand, their sources should be separated independently from various local soil sources having similar elemental compositions. While it is difficult to estimate total mass loadings of pure yellow sand by traditional bulk analysis, it can be clearly solved by an particle-by-particle analysis. To perform this study, two yellow sand samples and three local soil samples were collected by a mini-volume sampler. These samples were three analyzed using a scanning electron microscope(SEM) equipped with an energy dispersive x-ray analyser (EDX) was used to obtain basic chemical information of individual yellow san particles. A total of 19 elements in a single particle were measured to develop a source profile with newly created homogeneous particle classes (HPCs) as chemical variables. The present study showed that the yellow sand samples as well as three local soil samples were characterized with reasonably well created HPCs. Finally the mass fraction of each HPC in each sample was calculated and then compared each other.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2006.05a
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• pp.31-34
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• 2006

In this study, $(Ba_{0.7}\;Sr_{0.3})TiO_3$ was coated on Pt/Ti/$SiO_2$/Si wafer by using Sol-Gel method. Coating process was repeated 3~5 times and then sintered at 750[$^{\circ}C$] for 1 hour. Each specimen was analyzed structure and electrical characteristics. In structure characteristics, EDX analyzed the samples ratio of the formation on the structural property. Thermal behavior was observed with TG-DTA and concluded that the heat-treatment of the samples was degreed 750[$^{\circ}C$]. Surface and section of thin films were observed with SEM.

• Environmental Engineering Research
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• v.9 no.5
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• pp.193-200
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• 2004

A study of the treatment of piggery wastes using a multilayered metal-activated carbon system followed by carbon bed filtration was carried out at bench scale. From the physicochemical properties obtained from samples treated with aqueous solutions containing metallic ions such as Ag$^+$, Cu$^{2+}$, Na$^{-}$, K$^+$ and Mn$^{2+}$, main inspections are subjected to isothem shape, pore distribution with micropore, SEM and EDX. Multilayered metal-activated carbons were contacted to waste water to inwestigate the simultaneous catalytic effect for the COD, BOD, T-N and T-P removal. From these removal performance was achieved. The high efficiency of the multilayered metal-activated carbon bed, satisfactory removal performance was achieved. The high efficiency of the multilayered metal-activated carbon bed was derermined by the properties of this material for trapping, catalytic effect and adsorption of organic solid particles.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.07a
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• pp.671-674
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• 2000

A children's electric shock accidents have broken out because children can easily insert sharp things in 220V receptacle holes. As the test result of pushing force, children's pushing force was about 2-4kg and the pushing force of sharp things was less than 2kg. Therefore, it is reason for electric shock that children's pushing force is large than pushing force of sharp things. We have measured insulation resistance for the receptacles of five companies during 50 weeks in humid condition. As these results, Insulation resistance for the receptacles of J. Co. had rapidly decreased with lapse of time. As the result for investigating the surface of receptacle by SEM and EDX, Al, Fe and Br, which weren't discovered at original form, were produced. Therefore, the receptacles of J. Co. should be the improved in the quality of insulating material because insulation resistance can be decreased in humid environment