• Title/Summary/Keyword: electrical resistance

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The Capacity of Applying Electrical Resistance Probe in Natural Corrosion Tests of Vietnam

  • Pham, Thy San;Le, Thi Hong Lien;Le, Quoc Hung
    • Corrosion Science and Technology
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    • v.2 no.2
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    • pp.98-101
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    • 2003
  • The Electrical Resistance Probe of carbon steel and weight loss coupons were exposed in atmosphere and in the lake water of Hanoi. The comparison of data received by two methods after one year exposure was presented. The correspondence of the data of these methods on the exposure time in both environments showed a capacity of using Electrical Resistance Probe in Vietnamese natural corrosion testing of Carbon steel.

Multiscale Characteristics of Electrical Contact Resistance (전기접촉저항의 멀티스케일 특징)

  • Lee, Chang-Wook;Jang, Yong-Hoon
    • Proceedings of the KSME Conference
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    • 2004.11a
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    • pp.404-409
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    • 2004
  • The electrical contact resistance is here estimated using the multiscale microcontact distribution of elastic contact between rough surfaces, simulated from the Archard's model, and the electrical contact conduction theory suggested by Greenwood. These analysis confirms that the electrical contact resistance is converged to a values, larger than would be obtained if the contact spots were widely separated and hence independent. In multiscale process, the base potential is close to the value of the potential difference between the contact surface and the extremity of body, suggesting a possibility to obtain the multiscale electrical contact resistance relations.

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Electrical Resistance Tomography: Mesh Grouping and Boundary Estimation Algorithms

  • Kim Sin;Cho Hyo-Sung;Lee Bong-Soo
    • International Journal of Contents
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    • v.1 no.1
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    • pp.1-5
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    • 2005
  • This paper presents the development and application of electrical resistance imaging techniques for the visualization of two-phase flow fields. Two algorithms, the so-called the mesh grouping and the boundary estimation, are described for potential applications of electrical resistance tomography (ERT) and results from extensive numerical simulations are also presented. In the electrical resistance imaging for two-phase flows, numerical meshes fairly belonging to each phase can be grouped to improve the reconstruction performance. In many cases, the detection of phase boundary is a key subject and a mathematical model to estimate phase boundary can be formulated in a different manner. Our results indicated that the mesh grouping algorithm is effective to enhance computational performance and image quality, and boundary estimation algorithm to determine the phase boundary directly.

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Electrical Properties of Yarned Carbon Nanotube Fiber Resistors (Yarned CNT Fiber 저항체의 전기적 특성)

  • Lim, Youngtaek;Lee, Sunwoo
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.30 no.1
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    • pp.59-62
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    • 2017
  • CNT (carbon nanotube) resistors with low resistance and negative TCR (temperature coefficient of resistance) were fabricated with yarned CNT (carbon nanotube) fibers. The CNT fibers were prepared by yarning CNTs grown on the silicone substrate by CVD (chemical vapor deposition) method. The CNT resistors were fabricated by winding CNT fibers on the surface of ceramic rod. Both metal terminals were connected with the CNT fiber wound on the ceramic rod. We measured electrical resistance and thermal stability with the number of CNT fibers wound. The CNT resistor system shows linearly decreased resistance with the number of CNTs wound on the ceramic rod and saturated at 20 strands. The CNT resistor system has negative TCR between $-1,000{\sim}-2,000ppm/^{\circ}C$ and stable frequency properties under 100 kHz.

Properties of Carbon for Application of New Light Source Technology

  • Lee Sang-Heon
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.19 no.5
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    • pp.477-479
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    • 2006
  • Carbon films was grown on Si substrates using the method of electrolysis for methanol liquid. Deposition parameters for the growth of the carbon films were current density for the electrolysis, methanol liquid temperature and electrode spacing between anode and cathode. We examined electrical resistance and the surface morphology of carbon films formed under various conditions specified by deposition parameters. It was clarified that the high electrical resistance carbon films with smooth surface morphology are grown when a distance between the electrodes was relatively wider. We found that the electrical resistance in the films was independent of both current density and methanol liquid temperature for electrolysis. The temperature dependence of the electrical resistance in the low resistance carbon films was different from one obtained in graphite.

Fabrication of Carbon Film for New Light Source (광원용 탄소박막의 합성)

  • Lee, Sang-Heon;Choi, Young-Sung;Park, Dae-Hee
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2006.06a
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    • pp.553-554
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    • 2006
  • Carbon films was grown on Si substrates using the method of electrolysis for methanol liquid. Deposition parameters for the growth of the carbon films were current density for the electrolysis. methanol liquid temperature and electrode spacing between anode and cathode. We examined electrical resistance and the surface morphology of carbon films formed under various conditions specified by deposition parameters. It was clarified that the high electrical resistance carbon films with smooth surface morphology are grown when a distance between the electrodes was relatively wider. We found that the electrical resistance in the films was independent of both current density and methanol liquid temperature for electrolysis. The temperature dependence of the electrical resistance in the low resistance carbon films was different from one obtained in graphite.

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Evaluation of the Electrical Resistance between ITO/black interlayer/Bus electrodes in a Plasma Display Panel (플라스마 디스플레이 패널에서 ITO/black interlayer/Bus 전극 간의 전기저항 평가)

  • Moon, Cheol Hee
    • Korean Journal of Metals and Materials
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    • v.46 no.2
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    • pp.97-104
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    • 2008
  • Black interlayer was introduced into between ITO and Bus electrodes to enhance a bright room contrast ratio of a plasma display panel. To measure the electrical resistance of the black interlayer, we designed two test patterns, type I and type II, of which type II pattern was successful. Using type II test pattern, the electrical resistance of the black interlayer was measured to be $300{\Omega}$ for $2{\mu}m$ thickness case and infinitely high for 4, $6{\mu}m$ thickness. This result shows that electrical resistance of the black interlayer in the ITO/black interlayer/Bus electrodes structure is a critical parameter which determines the electrical characteristics of the PDP.

Development of Contaminant Leakage Detection System Using Electrical Resistance Measurement: ll. Evaluation of Applicability for Landfill Site by Field Model Tests (전기저항 측정기법을 이용한 오염물질 누출감지시스템의 개발: II. 현장모형시험을 통한 매립지에의 적용성 평가)

  • 오명학;이주형;박준범;김형석;강우식
    • Journal of the Korean Geotechnical Society
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    • v.17 no.6
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    • pp.225-233
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    • 2001
  • Field model tests were performed to develop the grid-net landfill leachate leakage detection system using electrical resistance. Electric circuit tests were also carried out to investigate the expected electrical effects of grid-net electric circuit. The resistance of leaking point showed lower value than that of non leaking point. Grid-net leakage detection system was thought to be effective to locate the leachate leaking point. The measured electrical resistance along the wire including the leaking point was slightly reduced following the reduction of electrical resistance at the leaking point, which was explained by electric circuit test results.

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Temperature Dependence of Volume Resistivity on Epoxy Nano-composites (에폭시 나노컴퍼지트 체적 고유저항의 온도 의존성)

  • Kim, Chang-Hoon;Lee, Young-Sang;Kang, Yong-Gil;Park, Hee-Doo;Shin, Jong-Yeol;Hong, Jin-Woong
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.24 no.10
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    • pp.834-838
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    • 2011
  • This research shows the electrical characteristic using excellent epoxy nano-composite of MgO 5.0 wt% and $SiO_2$ 0.4 wt% in mechanical strength test depending on nano-additive. First of all, volume resistance depending on nano-additive and temperature using high resistance meter (HP. 4329A) by increasing 10, 100, 1,000 V of applying voltage was measured. Moreover, temperature range of $25{\sim}120^{\circ}C$ with virgin sample was tested using TO-9B oven by Ando Company. The result showed that virgin and the samples added with MgO and $SiO_2$ had similar value of volume resistance in low temperature and low electric field region and reduced with slow slope. The nano-composite's volume resistance of sample added with MgO and $SiO_2$ had higher value than virgin sample's volume resistance in high temperature region more than $80^{\circ}C$. Moreover, the slope has steeply reduced. The volume resistance of sample added with MgO 5.0 wt% was $8.38{\times}10^{13}\;{\Omega}{\cdot}cm$ and it was 6.8 times more than virgin sample in high temperature at $120^{\circ}C$. The insulation characteristics were constant although filler has changed in low temperature region. But, in high temperature region, the value of volume resistance of sample with MgO 5.0 wt% was 7.6 times more than the virgin sample's volume resistance.