• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1999년도 추계학술대회 논문집
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• pp.505-508
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• 1999

In this study, weight loss, ESDD, surface conductivity and leakage current were measured at the different saline solutions by salt fog method. The magnitude of leakage current was higher at higher conductivity of 2 S/m saline water, but weight loss ESDD and surface conductivity which are indices of degradation were lower. This is considered that the current includes mainly ohmic component which doesn\`t contribute to surface degradation. In addition, it is shown that FFT could be useful in measuring initial transition from hydrophobic to hydrophilic surface.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1997년도 추계학술대회 논문집
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• pp.418-420
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• 1997

We synthesized the polymer that can have function group and improvement of mechnical strength and then confirmed the possibility of molecular device made by LB method. In this paper, the $\pi$-A isotherm has been investigated as to the kinds and various concentrations of the metal ions complexed with imidazole group. The experimental results for the electrical properties of MIM fabricated has been obtained as following. There is no change in limiting area as to the kinds of the metal ions, also the shift of conductivity as to the metal ions couldn't be observed, which was 10$\^$-14/[S/cm]. There are some changes in limiting area as to the concentration of the metal ions, the conductivity shift was increased with the occupied molecular area.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2000년도 춘계학술대회 논문집 유기절연재료 방전 플라즈마
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• pp.82-85
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• 2000

Polymeric composite insulators are used for outdoor insulation. However, our knowledge about their long-term performance in an outdoor environment is still very limited. The electrical stress caused the surface of these insulators to become degradation. In order to evaluate the tracking resistance of polymer insulators, we performed the tracking wheel test which is recommended by CEA LWIWG-01. And the flashover voltage tests were conducted for understanding electrical characteristics after tacking wheel test. Also, these insulators are studied by characterization methods such as contact angle measurement, SEM, etc.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2000년도 추계학술대회 논문집
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• pp.395-398
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• 2000

In this study mechanical and environment ability of FRP pole for a distribution line about high strength and good insulation properties. The basic filament winding process creates a helical winding pattern. In mechanical analysis of splice with mechanical fastened joint it is important to evaluate a critical load of faster having maximum stress. It is also present a result of several examples to compare this with analytical one. On repair design this finite element method will be used as basis. The influence of environmental factors, such as elevated temperatures, high humidity, and corrosive fluids, and ultraviolet(UV) rays, upon the performance of polymeric matrix composite is of concern in many applications.

• 한국분말야금학회:학술대회논문집
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• 한국분말야금학회 2006년도 Extended Abstracts of 2006 POWDER METALLURGY World Congress Part 1
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• pp.91-92
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• 2006

Metallic foams have a combination of attractive properties such as high specific mechanical properties and good energy absorption characteristics. This paper presents the properties of steel foam sandwiches produced using powder metallurgy approach. Metallic powder, solid polymeric binder and a foaming agent are dry-mixed and molded into the desired shape. The molded powder mix is then heat-treated to foam, debind and sinter the material. The resulting material has an open cell structure with high porosity. The structure and properties of sandwiches specimens produced with the process are presented and discussed.

• 연구논문집
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• 통권24호
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• pp.81-96
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• 1994

To investigate failure mechanisms observed in carbon-phenolic thermal insulators, differential equations which govern the decomposition process in a deformable anisotropic porous solid are derived for three-dimensional axisymmetric constructions. The governing equations not only couple the material deformation with pore pressure, but also couple pressure and temperature, which means that heat convected by the pyrolysis gases is properly accounted for. Then the Bubnov-Galerkin finite element method is applied to these equations to transform them into a semidescrete finite element system. A thermal insulation liner in the cowl region under typical operating conditions is analyzed to find a mechanism for plylift. The results from the structural analysis show across-ply failure in the cowl zone. The mechanism for plylift is hypothesized as a sequential procedure : 1) the across-ply failure which is the precursor to plylift and 2) the local fiber buckling caused by generation of excessive in-plane compressive stress. To prevent plylift, the across-ply stress can be reduced by using appropriate material ply angles in cowl zone design.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2000년도 하계학술대회 논문집
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• pp.824-827
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• 2000

Fabrication of InP-based photonic devices by dry etch Process is important for clear formation of waveguide mesa structure. We have developed more efficient etch process of the inductively coupled plasma (ICP) with low damages and less polymeric deposits for the InP-based photonic devices than the reactive ion etching (RIE) technique. We report the tendency of etch rate variation by the process parameters of the RF power, pressure, gas flow rate, and the gas mixing ratio. The surface roughness of InP-based waveguide structure was more improved by the light wet etching in the mixed solution of H$_2$SO$_4$:H$_2$O (1:1)

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2000년도 하계학술대회 논문집
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• pp.265-269
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• 2000

Nowadays the hydrophilic polymeric networks (polymer hydrogels) due to the complex of benefit physico-chemical properties attract a wide attention of specialists working in various fields of science, medicine and technology. The special attention of chemists is aimed on so-called stimuli-sensitive or intelligent hydrogels, which can undergo a volume phase transition in response to change in environmental parameters such as temperature, pH, solvent composition, etc [1]. Scientific group of Kazak State National University, Department of Macromolecular Chemistry works in this field [2-5]. Here we report about our achievements on pH-sensitive hydrogens.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2004년도 하계학술대회 논문집 Vol.5 No.1
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• pp.425-428
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• 2004

65% of the Korean peninsula is composed of mountainous area, 97% of which is composed of forest. Therefore, there is high possibility of mountain fire because a lot of potential inflammables such as fallen leaves are stacked on the ground. Moreover, most of the overhead transmission lines in Korea are operated on the mountain. However, there has been very little study for the effect of mountain fire on polymeric insulator for transmission line, though the study is significantly required Therefore, in this study the authors observed the deformation of the housing of the insulator under fire with respect to the ignition time, using artificial ignition testing equipment, and investigated electrical and mechanical characteristics of the insulator by dry withstand voltage test, impulse flashover test and tensile load test.

• 한국정밀공학회지
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• 제13권9호
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• pp.130-137
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• 1996

In the present paper the effect of various process conditions on the final weight of injection molded rectangular plates has been investigated in detail. The main parameters involved in the simulations were melt temperature, mold temperature, injection speed and packing pressure. The dimensions of the plate used were 100mm long, 2mm of width and polystyrene was used as a molding material. The shear viscosity of the polymeric material was treated as a function of shear rate, temperature and pressure through the whole processes including packing and cooling stages. By increasing a packing pressure the final weight of sample increased linearly. Furthermore, as the melt temperature, the mold temperature and the injection speed increased, the final weight of the injection molded plate decreased within the molding window.