• Membrane Journal
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• v.5 no.3
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• pp.109-118
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• 1995

In this study, cell resistivity and membrane resistivity were measured in Fe-Cr redox-fiow battery system using commercial ion-exchange membranes. Cell resistivity and membrane resistivity at charging periods are higher than at discharging periods. And at the same membrane the resistivity were increased with increasing SOC. The resistivity of hydrocarbon type Seiemion CMV membrane was smaller than perfluoro type Nafion 117 and Nafion 551. The cell resistivity and membrne resistivity of CMV membrane at 0 % SOC was $12.864\Omega \textrm{cm}^2$ and $8.751\Omega \textrm{cm}^2$, respectively.

• Proceedings of the Korean Geotechical Society Conference
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• 2009.03a
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• pp.464-475
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• 2009

Electrical resistivity can be used for porosity estimation. In order to improve previously developed ERCP(Electrical Resistivity Cone Probe), 4ERP(4 Electrical Resistivity Probe), which has Wenner array at the tip of probes, has been developed. In properties of current flow Wenner array measures electrical properties of undisturbed area during penetration and relatively correct measurements are guaranteed without polarization. Furthermore, Wenner array equation can estimate electrical resistivity without extra calibration. 4ERP is developed into 2 types, penetration and fixation. Penetration type has wedge-shaped tip. Considering disturbance minimization, fixed type has plane tip. Fixed type 4ERP in consolidation cell measure electrical resistivity increment along porosity decrease, and penetration type 4ERP measured resistivity profile along the depth in chamber. Applying Archie's law, porosity profile was estimated with electrical resistivity. The tests result suggests that 4ERP can be new site investigation equipment with little disturbance.

• Journal of the Korean Geophysical Society
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• v.2 no.4
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• pp.269-276
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• 1999

As a part of trying to get the resistivity values correctly from laboratory core resistivity measurement, the effect of sample holders in resistivity measurement was analyzed and a better way to determine the representative resistivity value from the time series resistivity data was searched. Modified GS type and modified two-electrode type sample holders were devised and their effects have been compared with those of GS and two-electrode type sample holders. The modified two-electrode type sample holder has benefits both in repetition and simplicity in data acquisition. The analysis of distribution trend of the time series resistivity data obtained with different kind of sample holders and source frequencies shows that the maximum curvature point method gives the best result in determining representative resistivity value.

• Proceedings of the Korean Geotechical Society Conference
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• 2003.03a
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• pp.265-272
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• 2003

In this study, the rock mass classification results from the face mapping and the resistivity inversion data are compared and analyzed for the reliability investigation of the determination of the rock support type based on the surface electrical survey. To get the quantitative correlation, rock engineering indices such as RCR(rock condition rating), N(Rock mass number), Q-system based on RMR(rock mass rating) are calculated. Kriging method as a post processing technique for global optimization is used to improve its resolution. The result of correlation analysis shows that the geological condition estimated from 2D electrical resistivity survey is coincident globally with the trend of rock type except for a few local areas. The correlation between the results of 3D electrical resistivity survey and the rock mass classification turns out to be very high. It can be concluded that 3D electrical resistivity survey is powerful to set up the reliable rock support type.

• Proceedings of the Materials Research Society of Korea Conference
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• 2011.05a
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• pp.237.1-237.1
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• 2011

Resistivity of GaN has been investigated under the influence of ion implantation. n-type, p-type and also undoped GaN has been used here. A ring shape pattern of Au was fabricated on GaN film by the photolithography technique. H, He and Ar were used for implantation. The ion implantation energy, fluence and post-implant annealing temperature varied in this research. Because of the making barrier in some selected area using ions, the resistivity changed in all the samples with the change of both fluence and energy. At room temperature, the resistivity of n-type GaN has been increased from $1.9{\times}10-2$ to $17.7{\times}10-2\;{\Omega}-cm$. This is high for He ion. But undoped and p-type GaN showed some anomalous character.

• Computers and Concrete
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• v.21 no.1
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• pp.1-9
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• 2018

Electrical resistivity is a property associated with both the physical and chemical characteristics of concrete. It allows the evaluation of the greater or lesser difficulty with which aggressive substances penetrate the concrete's core before the dissolution of the passive film process and the consequent reinforcement's corrosion begin. This work addresses the steel fiber addition to concrete with two types and various contents from 0% to 1.3%, correlating it with its electrical resistivity. To that effect, 9 different mixes of steel fiber reinforced concrete (SFRC) were produced. The electrical resistivity was evaluated on the on six years aged SFRC by direct measurement at different frequency from 0.1 kHz to 100 kHz. The results indicate that steel fiber content is strongly conditioned by the type and quantity of the additions used. It was also found that long type of fibers has more effect on decreasing the electrical resistivity of concrete than short fibers. Therefore, they increase the corrosion risk of concrete depending on fiber volume fraction and moisture percentage.

• Journal of the Semiconductor & Display Technology
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• v.11 no.3
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• pp.63-67
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• 2012

The films were deposited at evaporator system and were annealed at heat treatment. The films had a dense microstructure with fine grains. The electrical properties of the films were dramatically controlled with annealing. Samples Preparation were analyzed in term of positive temperature coefficient of Resistivity Samples were made in the substrate tempera-true of $400^{\circ}C$ deposition time of 10 hours, and forward power of 210watt. R-T(resistivity-temperature) Characteristics of the samples were investigated as a function of the substrate type and the ambient temperature. The resistivity of the thin film specimens was compared with that of the bulk type specimens. By using RF/DC magnetron sputtering system, we obtained lower resistivity in the thermistor with thin $BaTiO_3$ film than that in the bulk type thermistor.

• Tunnel and Underground Space
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• v.13 no.4
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• pp.279-286
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• 2003

Many trials to set up the correlation between the rock mass classification and the earth resistivity have been carried out to design tunnel support type based on the interpreted electrical resistivity acquired by surface electrical survey. But it is hard to find reports on the comparison of the real rock support type determined during the excavation with the electrical resistivity by the inversion of the survey data acquired before the tunneling. In this study, the rock mass classification based on the face mapping data and the resistivity inversion data are investigated to see if it is possible to design reliably the rock support type based on the surface electrical survey. To get the quantitative correlation, rock engineering indices such as RCR(rock condition rating), N(Rock mass number), Q-system and RMR(rock mass rating) are calculated. Since resistivity data has low resolution, Kriging method as a post processing technique which minimizes the estimated variance is used to improve resolution. The result of correlation analysis shows that the 2D electrical resistivity survey is appropriate to see the general trend of the geology in the sense of rock type, though there might be some local area where these two factors do not coincide. But the correlation between the result of 3D survey and the rock mass classification turns out to be very high, and then 3D electrical resistivity survey can make it possible to set up more reliable rock support type.

• Journal of Powder Materials
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• v.18 no.5
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• pp.423-429
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• 2011

Thermoelectric-thick films were fabricated by using a screen printing process of n and p-type bismuth-telluride-based pastes. The screen-printed thick films have approximately 30 ${\mu}m$ in thickness and show rough surfaces yielding an empty gap between an electrode and the thick film. The gap might result in an increase of an electrical resistivity of the fabricated thick-film-type thermoelectric module. In this study, we suggest a conductive metal coating onto the surfaces of the screen-printed paste in order to reduce the contact resistance in the module. As a result, the electrical resistivity of the thermoelectric module having a gold coating layer was significantly reduced up to 30% compared to that of a module without any metal coating. This result indicates that an introduction of conductive metal layers is effective to decrease the contact resistivity of a thick-film-typed thermoelectric module processed by screen printing.

• 한국지구물리탐사학회:학술대회논문집
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• 2009.05a
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• pp.73-87
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• 2009

Geophysical survey for unconformity-type uranium deposit applied to this study area in Athabaska Basin, Canada were carried out airborne TEM and magnetic, resistivity-induced polarization (DC-IP), puser seismic reflection and well-logging method. The results of airborne survey interpreted the lithological boundary, geological structures, and conductors. Also, these results decided to main targets for ground DC-IP survey. The Low resistivity and the high chargeability slices of 3D modeling interpreted from DC-IP survey response for conductors related to hydrothermal alteration zones and fault-controlled graphitic zones occurring at the unconformity-type uranium deposit, and they confirmed by diamond drilling. Seismic results interpreted to lake bottom surface, alluvium layer and intra-sandstone faults. We suggest the resonable field data acquisition of DC-IP method on the land or the lake in Athabaska Basin.