• Title/Summary/Keyword: applied potential

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Electrosorption of Uranium Ions in Liquid Waste

  • Lee, Hye-Young;Jung, Chong-Hun;Oh, Won-Zin;Park, Jin-Ho;Shul, Yong-Gun
    • Carbon letters
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    • v.4 no.2
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    • pp.64-68
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    • 2003
  • A study on the electrosorption of uranium ions onto a porous activated carbon fiber (ACF) was performed to treat uraniumcontaining lagoon sludge. The result of the continuous flow-through cell electrosorption experiments showed that the applied negative potential increased the adsorption kinetics and capacity in comparison to the open-circuit potential (OCP) adsorption for uranium ions. Effective U(VI) removal is accomplished when a negative potential is applied to the activated carbon fiber (ACF) electrode. For a feed concentration of 100 mg/L, the concentration of U(VI) in the cell effluent is reduced to less than 1 mg/L. The selective removal of uranium ions from electrolyte was possible by the electrosorption process.

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Characterization of Potential Probiotics Bacillus subtilis CS90 from Soybean Paste (Doenjang) and Its Antimicrobial Activity against Food-borne Pathogens

  • Cho, Kye-Man
    • Journal of Applied Biological Chemistry
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    • v.51 no.6
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    • pp.285-291
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    • 2008
  • A potential probiotics bacterial strain, CS90, was isolated from Korean soybean paste (doenjang). The strain CS90 showed antimicrobial activity against food-borne pathogenic bacteria including Salmonella enterica, Salmonella enteritids, Salmonella typhymurium, Bacillus cereus, Listeria ivanovii, Listeria. monocytogenes, Sthaphylococcus aureus, and Sthaphylococcus epidermidis and showed a significant survival rate of 35.7 to 57.8% under the artificial gastric acidic condition (pH 2 to 3). The strain CS90 was classified as Bacillus subtilis based on morphological, physiological, chemotaxonomic features and phylogenetic analysis based on 16S rDNA sequence and designated as B. subtilis CS90. B. subtilis CS90 can be used as a potential probiotics.

A STUDY ON THE GRID GENERATION FOR TWO-DIMENSIONAL FLOW USING A POTENTIAL SOLVER (포텐셜 해석자를 이용한 2차원 유동의 격자 생성 연구)

  • Lee, J.;Jung, K.
    • Journal of computational fluids engineering
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    • v.21 no.1
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    • pp.36-42
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    • 2016
  • One of the obstacles on the grid generation for complex geometries with multi-block structured grids is the domain decomposition. In this paper, the domain decomposition for two-dimensional flow is studied using the flow characteristics. The potential flow equation with the source distribution on the panel surface is solved to extract the information of the flow. The current approach is applied to a two-dimensional cylinder and Bi-NACA0012 problems. The generated grids are applied to generic flow solvers and reasonable results are obtained. It can be concluded that the current methods is useful in the domain decomposition for the multi-block structured grid.

A Study on an Address Discharge Time Lag and a Wall-Charge Loss Due to the Potential (AC-PDP구동에서 전위차로 인한 벽전하의 소실과 어드레스 방전 지연시간에 관한 연구)

  • Jeon, Won-Jae;Kim, Dong-Hoon;Kim, Jong-Yeol;Lee, Seok-Hyun;Lee, Cheon
    • Proceedings of the KIEE Conference
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    • 2008.07a
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    • pp.1315-1317
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    • 2008
  • The plasma display panel is an image expression display using gas discharge. However gas discharge characteristics vary with temperature. Furthermore, the potential difference among three electrodes appears in sustain period due to external applied voltages. It affects to the wall charge state accumulated on the electrodes. This research aims at identifying that the discharge characteristics depend on the potential difference and temperature. The results show that the wall charge loss increases with increase of the number of applied pulse during sustain period and it severely appears at high temperature.

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Comparison of hydrogen embrittlement resistance between 2205 duplex stainless steels and type 316L austenitic stainless steels under the cathodic applied potential (음극 인가전위 하에서 type 2205과 type 316L의 수소취성 저항성)

  • Seo, Dong-Il;Lee, Jae-Bong
    • Corrosion Science and Technology
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    • v.15 no.5
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    • pp.237-244
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    • 2016
  • 2205 duplex stainless steels have been used for the construction of the marine environment, because of their excellent corrosion resistance and high strength. However, the resistance to hydrogen embrittlement (HE) may be less than that of 316L austenitic stainless steel. The reason why 316L stainless steels have better resistance to HE is associated with crystal structure (FCC, face centered cubic) and the higher stacking faults energy than 2205 duplex stainless steels. Furthermore 2205 stainless steels with or without tungsten were also examined in terms of HE. 2205 stainless steels containing tungsten is less resistible to HE. It is because dislocation tangle was formed in 2205 duplex stainless steels. Slow strain-rate tensile test (SSRT) was conducted to measure the resistance to HE under the cathodic applied potential. Hydrogen embrittlement index (HEI) was used to evaluate HE resistance through the quantitative calculation.

A Study on the Protection of the Bare and Painted Steel Plates (아연 양극에 의한 도장강판과 나강판의 방식 연구)

  • 문경만;김종신;김진경
    • Journal of Advanced Marine Engineering and Technology
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    • v.17 no.1
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    • pp.55-65
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    • 1993
  • Galvanic protection method is one the cathodic protection methods and is mostly used for corrosion prevention of heat exchangers and ship's hull. In this paper, it was investigated that how cathodic potential distribution was varied with according to the bare and painted steel plates in case of galvanic anode protection. The results obtained above were as follows. 1. Cathodic potential distribution of a painted steel plate was smoothed than that of the bare steel plate all over the cathodic surface area. 2. It was shown that polarization potential of the bare steel plate was somewhat shifted to negative potential, on the contrary that of the painted steel plate was somewhat shifted from negative potential to positive potential as time gone by beginning of galvanic anode method. 3. The applied current density in order to maintain constant protection potential(-770mv SCE) in the painted steel plate was less than that of the bare steel plate because of the high resistance polarization of the painted steel plate. 4. It was suggested that required number and life-time of anode for galvanic anode protection could be decided easily with corrosion prevention coefficient obtained by experimental data.

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The Problems in the Measurement of DC Potential on Meridian Skin Area (경락노선상 직류 전위 측정에서의 문제점)

  • Heo, Ik-Beom;Lee, Woo-Cheol;Lee, Yoo-Jeong;Yin, Chang-Shik
    • The Journal of the Society of Korean Medicine Diagnostics
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    • v.9 no.1
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    • pp.131-135
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    • 2005
  • Background and purpose: The measurement of direct current (DC) potential on skin area of meridian has recently been adopted to explore the electrophysiological characteristics of meridian system, But there exists two problems to be explained; the entity of the DC potential to be measured and the characteristics of electrode gel interface of measurement system, It is not clear whether the DC potential reflect, at least hypothetically, the entity of meridian, and if there exist any unstable factor in the DC potential measurement system. Methods: In this study, we designed an electronic circuit model of skin and applied known DC potential sources $({\pm}10.75mV,\;0mV)$ to the electrode interface of the skin model. Results: The result showed that the measured DC potential changed according to the time, and the same phenomenon was observed when the electrode gel was replaced with an electric condenser. It is suggested that the measurement of DC potential on electrode gel interface is very difficult and produces unstable values due to the capacity effect of electrode gel. Conclusion: Further studies on the DC potential evaluation in the context of meridian study should consider and bypass this problem.

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The Relationship between Electroosmotic Drainage and Zeta Potential of Contaminated Clayey Soil with Heavy Metal (중금속 오염 점성토의 전기삼투 배수와 제타포텐셜의 상관성)

  • 임성철;한상재;김정환;김수삼
    • Proceedings of the Korean Geotechical Society Conference
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    • 2000.11a
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    • pp.455-460
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    • 2000
  • This research is about the relationship of electroosmotic drainage and zeta potential. Two laboratory experiments were conducted, at first a constant 16 voltage was applied to the cylindrical consolidated specimen of 10cm in diameter, 16cm in length at the concentration of 0, 500, 3000ppm Pb(II) and electroosmotic flow was measured for 12days. Then, zeta potential of kaolinite suspension was measured at the same concentration of electroosmotic permeability experiments in the range of pH from 2 to 14. From the result of this study, it was shown that zeta potential was dependent on the concentration of electrolyte and pH, was proportional to coefficient of electroosmotic permeability. According to the compared result of electroosmotic drainage, as the concentration of Pb(II) was low, the negative value of zeta potential was high and electroosmotic total flow was much.

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Preliminary Estimation of Wind Resource Potential in South Korea (남한 풍력자원 잠재량의 예비적 산정)

  • Kim, Hyun-Goo
    • Journal of the Korean Solar Energy Society
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    • v.28 no.6
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    • pp.1-7
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    • 2008
  • The wind resource potentials of South Korea are estimated as preliminary stage using the national wind map which has been being established by numerical wind simulation and GIS (Geographical Information System) exclusion analysis. The wind resource potentials are classifying into theoretical, geographical, technical and implementation potentials and the calculation results are verified by comparing to other countries' potentials. In GIS exclusion, urban, road, water body, national parks and steep slope area are excluded from onshore geographical potential while water depth and offshore distance from the shoreline are applied as offshore exclusion conditions. To estimate implementation potential, dissemination records of European countries are adopted which is about 1/8 of geographical potential. The implementation potential of South Korea would correspond 12.5GW which is 1.7 times of the national wind energy dissemination target until 2030.