• Title/Summary/Keyword: Complex resistivity

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Industry-University-Research Collaborative Geoscientific Study in Pocheon Area for Groundwater Survey, Part III : Resistivity Technology (포천지역 지하수기초조사 산학연 공동탐사 사례연구(III): 전기탐사기술)

  • You, Young-June;Kim, Jong-Nam;Yoo, In-Kol
    • 한국지구물리탐사학회:학술대회논문집
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    • 2005.05a
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    • pp.129-136
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    • 2005
  • The groundwater survey was carried out by electrical resistivity and resistivity tomography using several kinds of electrode array to delineate the depth of the saturated zone and basement complex, the aquifer system of fractured rock, and the 2-D resistivity structure was obtained by inversion technique. And the hole-to-surface and crosshole tomography were applied for two boreholes and the inverted resistivity tomogram are obtained. The comparison of those data with core logging data was performed and those results were relatively well correlated. And it was possible to find out the configuration of basement and the fracture zone and the aquifer system from the 2-D resistivity structure and resistivity tomogram.

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Study of complex electrodeposited thin film with multi-layer graphene-coated metal nanoparticles

  • Cho, Young-Lae;Lee, Jung-woo;Park, Chan;Song, Young-il;Suh, Su-Jeong
    • Carbon letters
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    • v.21
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    • pp.68-73
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    • 2017
  • We have demonstrated the production of thin films containing multilayer graphene-coated copper nanoparticles (MGCNs) by a commercial electrodeposition method. The MGCNs were produced by electrical wire explosion, an easily applied technique for creating hybrid metal nanoparticles. The nanoparticles had average diameters of 10-120 nm and quasi-spherical morphologies. We made a complex-electrodeposited copper thin film (CETF) with a thickness of $4.8{\mu}m$ by adding 300 ppm MGCNs to the electrolyte solution and performing electrodeposition. We measured the electric properties and performed corrosion testing of the CETF. Raman spectroscopy was used to measure the bonding characteristics and estimate the number of layers in the graphene films. The resistivity of the bare-electrodeposited copper thin film (BETF) was $2.092{\times}10^{-6}{\Omega}{\cdot}cm$, and the resistivity of the CETF after the addition of 300 ppm MGCNs was decreased by 2% to ${\sim}2.049{\times}10^{-6}{\Omega}{\cdot}cm$. The corrosion resistance of the BETF was $9.306{\Omega}$, while that of the CETF was increased to 20.04 Ω. Therefore, the CETF with MGCNs can be used in interconnection circuits for printed circuit boards or semiconductor devices on the basis of its low resistivity and high corrosion resistance.

The role of grain boundary modifier in $BaTiO_3$ system for PTCR device ($BaTiO_3$계 PTC 재료에서 입계 modifier의 역할)

  • Lee, Jun-Hyeong;Jo, Sang-Hui
    • Korean Journal of Materials Research
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    • v.3 no.5
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    • pp.553-561
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    • 1993
  • In this study, thr effect of $Bi_2O_3$ and BN addition as grain boundary modifiers on sintering and electrical properties of semiconducting PTCR(Positive Temperature Coefficient of Resistivity) mate rial were analyzed using TMA, XRD and Complex Impedance Spectroscopy method. Bismut.h Ox~de and Boron Nitride were added to Y-doped $BaTiO_3$ respectively. Bismuth sesquioxide up to O.lmol%solubil~ ty limit of $Bi_2O_3$ in Y--$BaTiO_3$ ceramics-retarded densification and grain growth, and further addition mitigated these retardation effects. The resistivity at room temperature increased with increasing amount of $Bi_2O_3$ and thus decreased the PTCR effect, probably due to the $Bi_2O_3$ segregation on the grain boundaries. From the complex ~mpedance pattern, it is known that the grain boundary resisitivity is dominant on the whole resistivity of sample. In the result of applying the defect chemistry, $Bi^{3+} \;and \; Bi^[5+}$ are substituted for Ua and Ti site, respectively. Boron nitride decomposed and formed liquid phase among the $BaTiO_3$ grains. The decomposed com~ ponents made the second phase and existed the tr~ple juntion from the result of EPMA. From the complex impendencc pattern, the gram and grain boundary resistivity were small. The grain size increased with increasing BN contents, and decreased grain boundary resistivity enhanced the PTCR effect.

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Dispersibility, Electrical Property of Nano-Composite by Solution Mixing Method (용액혼합법에 따른 나노복합재료 분산성 및 전기적 특성)

  • Yang, Hoon;Park, Dae-Hee
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2008.04c
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    • pp.73-74
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    • 2008
  • In this paper, we have investigated dispersibility, volume resistivity of nano-composite by solution mixing method. Dispersibility measured by FE-SEM(Field Emission Scanning Electron Microscope. And volume resistivity measured by ASTM D991. To expect interaction used dual filler system. But, dual filler system had influence on polymer complex. So, polymer chain mobility doesn't resist.

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Interpretation of Electrical Resistivity Tomogram with Contents of Clay Minerals for the Land Creeping Area (점토광물 함유량을 고려한 땅밀림 산사태 지역의 전기비저항 자료의 해석)

  • Kim, Jeong-In;Kim, Ji-Soo;Lee, Sun-Joong;Cho, Kyoung-Seo;Kim, Jong-Woo
    • The Journal of Engineering Geology
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    • v.31 no.2
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    • pp.187-197
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    • 2021
  • Clay mineral content of weathered zone is a key parameter for landslide studies. Electrical resistivity tomography is usually performed to delineate the geometry of complex landslides and to identify the sliding surface. In clay-bearing weathered zone, parallel resistivity Archie equation is employed to investigate the effect of conductivity added (resistivity reduced) by clay minerals of kaolinite and montmorillonite, which is dependent on their specific surface area and cation exchange capacities (CEC). A decrease of overall resistivity and apparent formation factor is observed with increasing pore-water resistivity, significantly in montmorillonite. Formation factor is found decreased with increasing porosity and decreasing cementation factor. Parallel Archie equation was applied to the electrical resistivity data from the test area (Sinjindo-ri, Taean-gun, Chungcheongnam-do, Korea) which experienced land creeping in the year of 2014. A panel test with varying clay-mineral contents provides the best fit section when the theoretical section constructed with the assumed contents approaches the field section, from which the clay-mineral content of the weathered zone is estimated to be approximately 10%. Resistivity interpretation schemes including the clay mineral contents for land creeping studies explored in this paper can be challenged more when porosity, saturation, and pore-water resistivity are provided and they are included in the numerical resistivity modeling.

A Study on the Identification of Equivalent Uniform Soil Model for Grounding Design of 500[tV] Transmission Towers (500[kV] 송전철탑 접지설계를 위한 다층토양구조의 균일매질 등가화에 관한 연구)

  • Choi, Jong-Kee;Lee, Sung-Doo;Lee, Dong-Il;Jung, Gil-Jo;Kim, Kyung-Chul
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.19 no.6
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    • pp.22-28
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    • 2005
  • The electrical characterstic of earth is the most dominant factor for grounding design and an earth is typically represented by a uniform medium with the specific earth resistivity, which is unique for a specific site. For a hand-working grounding design using a specific earth resistivity requires a process converting a real earth of complex medium into a simple uniform medium In this paper, we suggest a procedure to convert a multi-layered earth s into a simpler uniform earth for grounding design of Myanmar 500[kV] transmission towers.

A study on the effect of $TiO_2$ to the characterization of PTC thermister (PTC서미스터의 특성에 미치는 $TiO_2$의 영향에 관한 연구)

  • 신태현;김영조;이기택
    • Electrical & Electronic Materials
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    • v.8 no.1
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    • pp.83-89
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    • 1995
  • In this paper, the specimens-($Ba_{0.997}$ L $a_{0.003}$)Ti $O_{3}$ + xTi $O_{2}$, x=0.005, 0.01, 0.02, 0.03[mol]- were fabricated by a solid-state reaction method which is easy in microstructure control and good in mass production. Their crystalline structures and microstructures were analysed, and electrical properties were investigated. The perovskite-crystalline structure is confirmed by XRD, and it is exhibited by SEM that the grain grows with an addition of Ti $O_{2}$. Resistivity decreases with increasing sinteiing temperature, and the specimen of ($Ba_{0.997}$ L $a_{0.003}$)Ti $O_{3}$ + 0.02Ti $O_{2}$ sintered at 1350.deg. C shows the best PTC effects. The complex impedance plots exhibit the serial equivalent circuit of ( $R_{gb}$ / $C_{gb}$ ) and $R_{g}$ it is realized that PTC effect is attributed to the resistivity of grain boundary.ary.y.

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Analysis of distortion effect of resistivity data due to 3D geometry of fill dam (필댐의 3차원 기하 효과에 따른 전기비저항 왜곡 효과 분석)

  • Oh Seokhoon;Kim Hyoung-Soo
    • 한국지구물리탐사학회:학술대회논문집
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    • 2005.05a
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    • pp.55-58
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    • 2005
  • Low resistivity zone is observed at the lower part of a CFRD (Concrete Face Rockfill Dam). Generally, CFRD tends not to have any saturated zone within the body, but the result of resistivity survey shows that it is possible for the dam to be saturated under 20m depth with water. The level of reservoir was under 10m from the crest. We suspect that this result may come from the wrong 2D inversion process ignoring the 3D geometry of dams. For the analysis of possibility of distortion by different geometry, we perform the 3D forward modeling for the dam and apply the 2D inversion process. And then we check the point of traditional interpretation of resistivity data. By the analysis, it is found that the result of 2D inversion process of 3D geometry of dams, seems to have deep relation with the reservoir level, and the complex 3D structure hide some internal electrical anomaly of dams from resistivity information.

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Analysis of Distortion Effect of Resistivity Data Due to 3D Geometry of Fill Dam (필댐의 3차원 기하 효과에 따른 전기비저항 왜곡 효과 분석)

  • Oh, Seok-Hoon;Kim, Hyoung-Soo
    • Journal of the Korean Geophysical Society
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    • v.8 no.4
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    • pp.211-214
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    • 2005
  • Low resistivity zone is observed at the lower part of a CFRD (Concrete Face Rockfill Dam). Generally, CFRD tends not to have any saturated zone within the body, but the result of resistivity survey shows that it is possible for the dam to be saturated under 20m depth with water. The level of reservoir was under 10 m from the crest. We suspect that this result may come from the wrong 2D inversion process ignoring the 3D geometry of dams. For the analysis of possibility of distortion by different geometry, we perform the 3D forward modeling for the dam and apply the 2D inversion process. And then we check the point of traditional interpretation of resistivity data. By the analysis, it is found that the result of 2D inversion process of 3D geometry of dams, seems to have deep relation with the reservoir level, and the complex 3D structure hide some internal electrical anomaly of dams from resistivity information.

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Electrical resistivity and seismic reflection mapping for the southeastern part of the Yongdong basin (Cretaceous), Korea (영동분지(백악기) 남동부의 전기비저항 및 탄성파탐사자료 해석)

  • Kim, Ji-Su;Han, Su-Hyeong;Lee, Cheol-U;Kim, Bok-Cheol;Yang, U-Heon;Son, Ho-Ung;Son, Yeong-Gwan
    • Journal of the Korean Geophysical Society
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    • v.3 no.2
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    • pp.77-90
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    • 2000
  • Five electrical resistivity dipole-dipole and two seismic reflection surveys were performed in the southeastern margin of the Yongdong basin to delineate the shallow basin architecture. To investigate the intra-basin structure, twenty four resistivity sounding points and three dipole-dipole lines were selected especially in the vicinity of volcanic masses. The basin-fault boundaries are identified in electrical dipole-dipole resistivity section as high resistivity-contrast of approximately $1,500\;{\Omega}{\cdot}m$, characterized as a band of high standard-deviation. They are also effectively clarified in the seismic reflection data: amplitude and continuity contrasts in the common shot gather, first-arrival profiles, complex attribute plots. The intra-basin resistivity structures are constructed by interpolating vertical electrical sounding data and dipole-dipole profiles. The high-resistivity anomalies most likely originate from the northsouth-trending and northeast-dipping volcanic masses, which are to be further quantitatively investigated with geomagnetic and magnetotelluric surveys.

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