• 한국안전학회지
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• 제17권4호
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• pp.25-30
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• 2002

This paper demonstrates the effects of dust electrical resistivity on electrostatic precipitability. The effects of gas temperature, velocity and humidity on the collection efficency were considered by used of coal fly ashes from fluidized bed combustion boiler. The experiments for collection efficiency were carried out in the pilot plant. The ashes which have non-spherical geometry and high electrical resistivity were used. Electrical resistivity is an important property for the collection efficiency in the electrostatic precipitators. Fly ash resistivity as a function of temperature up $350{\circ}C$ and water concentration(up to 15%) has been experimentally investigated using the resistivity test equipment consisted of the movable electrode, dust cup, and furnace. As the resistivity of fly ash in the operating temperature($150{\circ}C$) of an electrostatic precipitator was measured higher than $1010{\Omega}{\cdot}$cm, flue gas conditioning in the electrostatic precipitator to reduce the resistivity of fly ash is required.

• KIEE International Transactions on Power Engineering
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• 제5A권4호
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• pp.350-356
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• 2005

Earth equipments are essential to protect humans and other types of equipment from abnormal conditions. Earth resistance and potential must be restricted within a low value. An estimation algorithm of earth parameters and equivalent resistivity is introduced to calculate reliable earth resistance in this research. The proposed algorithm is based on the relationship between apparent resistances and earth parameters. The proposed algorithm, which approximates the non-linear characteristics of earth by using the Artificial Neural Network (ANN), estimates the earth parameters and equivalent resistivity. The effectiveness of the proposed method is verified with case studies.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1997년도 추계학술대회 논문집 학회본부
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• pp.267-269
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• 1997

The electrical properties due to the Benzotriazole(following as BTA) additive in fluids for insulating and cooling the ultra-high voltage transformer is studied in this paper. Specimen having the several contents of BTA, such as 5[ppm]. 10[ppm] and 30[ppm] is used in order to investigate the characteristics on volume resistivity in case of fluid flow in experimental device made in lab. Volume resistivity is decreased with an increase of fluid flow velocity and increased with BTA content in low temperature region, but volume resistivity of specimen contained BTA 10[ppm] is the largest thing over $30[^{\circ}C]{\sim}50[^{\circ}C]$ than the others in experiment.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1996년도 춘계학술대회 논문집
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• pp.211-215
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• 1996

In this paper, the volume resistivity of transformer oil is made researches so that the electrical properties for transformer oil is investigated. The specimen is produced by the irradiation of electron beam classified into the low dose, such as 0.5[Mrad], 1[Mrad], 2[Mrad]. The effect of electron team irradiation is studied by investigating the electrical properties of dielectric liquid due to the difference of electron beam dose. To measure the physical properties of transformer oil, courier Transform-Infrared Spectroscopy is investigated. And the study far the electrical properties is made by measuring the volume resistivity of each specimen. By means of the result from this experiments, it is introduced that the movement of carrier to contribute to the volume resistivity on the electrical properties.

• 한국재료학회지
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• 제30권10호
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• pp.522-532
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• 2020

Conductive polymer composites with high electrical and mechanical properties are in demand for bipolar plates of phosphoric acid fuel cells (PAFC). In this study, composites based on natural graphite/fluorinated ethylene propylene (FEP) and different ratios of carbon black are mixed and hot formed into bars. The overall content of natural graphite is replaced by carbon black (0.2 wt% to 3.0 wt%). It is found that the addition of carbon black reduces electrical resistivity and density. The density of composite materials added with carbon black 3.0 wt% is 2.168 g/㎤, which is 0.017 g/㎤ less than that of non-additive composites. In-plane electrical resistivity is 7.68 μΩm and through-plane electrical resistivity is 27.66 μΩm. Compared with non-additive composites, in-plane electrical resistivity decreases by 95.7 % and through-plane decreases by 95.9 %. Also, the bending strength is about 30 % improved when carbon black is added at 2.0 wt% compared to non-additive cases. The decrease of electrical resistivity of composites is estimated to stem from the carbon black, which is a conductive material located between melted FEP and acts a path for electrons; the increasing mechanical properties are estimated to result from carbon black filling up pores in the composites.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 제37회 하계학술대회 논문집 D
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• pp.1795-1796
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• 2006

The accurate measurement of soil resistivity and earthing system resistance is fundamental to electrical safety. However, geological and meterological factors can have a considerable effect on the accuracy of conventional measurements and the validity of the measurement methods. This paper presents optimization method of dc resistivity data acquisition system using multi-electrode arrays.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2007년도 추계학술대회 논문집
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• pp.216-217
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• 2007

In this paper we investigated the volume resistivity and AC conduction current according to the temperature and voltage. As a result, the volume resistivity comes to be small according to the measurement temperature and voltage. AC conduction current of the heat treatment specimen is increased because of the decrease of insulation.

• 지질공학
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• 제22권4호
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• pp.409-416
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• 2012

가축사체 매몰지로부터 유출되는 침출수는 환경적으로 치명적인 영향을 주는 고농도 오염폐수의 일종이다. 본 연구에서는 효율적인 가축사체 매몰지의 특성을 파악하기 위하여 전기비저항 탐사와 함께 시추조사를 실시하였다. 또한, 가축사체 매몰지에서 샘플링한 침출수의 화학적 분석을 실시하였다. 매몰지 내부에서 5측선의 쌍극자 전기비저항 탐사와 3지점의 시추조사를 실시하였으며, 매몰지 주변의 11지점에서 시추조사를 수행하였다. 전기 비저항 탐사에 의하여 수집된 자료를 이용하여 2차원 역산 모델링을 수행하여 매몰지의 특성(크기, 심도, 형태 등)을 평가하였다. 침출수 분석결과, pH는 7.4에서 6.7로 감소하였고, Eh는 -358 mV에서 -48 mV로 변화하였다. 또한, 가축사체 부패에 의하여 용존 이온이 증가하였다. 전기비저항 탐사 자료의 해석결과, 지표에서 심도 8 m 이내에서 최소 $0.64{\Omega}m$의 낮은 비저항값을 가지는 영역이 나타났다. 이 지역의 기반암 위치와 가축사체의 매립 깊이를 고려할 때, 매립지 내부에서는 침출수에 의한 기반암의 오염은 진행되지 않은 것으로 나타났다. 전기비저항 탐사의 결과는 시추조사의 결과와 잘 일치 하였으며, 이는 전기비저항 탐사가 가축매몰지의 특성을 효과적으로 묘사한다는 것을 보여주었다. 본 연구에 의하면, 전기비저항 탐사가 가축사체 매몰지의 현황을 조사하는데 적합한 기술로 판단된다.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제55권8호
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• pp.381-386
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• 2006

In this study, we have investigated electrical and mechanical properties of semiconducting materials for power cable caused by CNT. Specimens were made of sheet form with the four of specimens for measurement. Volume resistivity of specimens was measured by volume resistivity meter after 10 minutes in the pre-heated oven of both $23{\pm}\;1\;[^{\circ}C]\;and\;90{\pm}\;1\;[^{\circ}C]$. And stress-strain of specimens was measured by TENSOMETER 2000. A speed of measurement was 200[mm/min], ranges of stress and strain were 400[Kgf/Cm2] and 600[%]. From this experimental results, the volume resistivity had different properties because of PTC/NTC tendency at between $23[^{\circ}C]\;and\;90[^{\circ}C]$. Also volume resistivity was low by increasing the content of CNT. It means that a small amount of CNT has a excellent electrical properties. And stress was increased, while strain was decreased by increasing the content of CNT. Thus, we could know that a small amount of CNT has a excellent electrical and mechanical oroperties.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2010년도 하계학술대회 논문집
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• pp.46-46
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• 2010

In this paper, we studied the volume resistivity and the electrical conductivity properties of nano composites to investigate the electrical properties of epoxy composites added nano MgO. The specimens were produced by classifying to 1.0, 3.0, 5.0, 10[wt%] and virgin specimen according to the addition amount of MgO. We measured the volume resistivity of nano filler using the High Resistance Meter(4329A) at the measuring temperature changed to 25, 50, 80, 100, and [$120^{\circ}C$]. As the result, it is confirmed that the volume resistivity was the highest stability and volume resistivity value is $2.6{\times}10^{17}\;[\Omega{\cdot}cm]$ at 3.0[wt%]. And it is confirmed that the electrical conductivity property is sharply increased at low electric filed region and the conductivity current density is rapidly increased at high electric filed region.