• Title/Summary/Keyword: Pulse-electrokinetic technology

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Comparison of Improving Dewatering Process at Clay-Sandy Soil based on Pulse-Electrokinetic Technology and Continuous-Electrokinetic Technology (펄스동전기법과 연속처리동전기법을 이용한 점토성-사질토의 탈수화 효율 비교)

  • Shin, Sanghee
    • Journal of the Korean GEO-environmental Society
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    • v.15 no.4
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    • pp.37-41
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    • 2014
  • Pulse electrokinetic technology is proposed for improving the dewatering-process from clay-sandy soil. Proposed electrokinetic technology is to be the dewatering process due to fluid movement of current flow for the stability of clay-sandy soils. Samples produced in this study were completed to verify the proposed performance for 7 days by gradually increasing the pressure to the final pressure of 30 psi ($2.11kgf/cm^2$) through the compression process. In this study, pulse electrokinetic treatment and conventional continuous electrokinetic treatment are tested and observed, respectively. The condition of continuous electrokinetic treatment is a continuous process during 48 hours. And the condition of pulse electrokinetic treatment system is to interrupt the power three times for 48 hours, every 8 hours. These treatments are that the voltage gradient is 3 V/cm. As a result, the efficiency of pulse electrokinetic is similar to the continuous electrokinetic. The power consumption efficiency of pulse electrokinetic is better than continuous electrokinetic.

A Study of Cement Grout for Pulse Powered Underreamed Anchors (펄스파워 확공형 앵커용 그라우트 연구)

  • Kang, Kum-Sik;Kim, Jae-Hyung;Cho, Gyu-Yeon;Kim, Tae-Hoon;Kim, Sun-Ju
    • Proceedings of the Korean Geotechical Society Conference
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    • 2009.09a
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    • pp.1107-1112
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    • 2009
  • The pulse powered anchor is a way to increase the capacity of ground anchor. The pulse powered anchor is an underreamed anchor by using high voltage electrokinetic pulse energy. In this study, property of cement grout for pulse powered underreamed anchor have been carried out. This study is what is the cement grout of pulse powered, for minimize seperation or sweep of cement grout when the soil layer is saturated with water.

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Dewatering of Sewage Sludge by Electrokinetics (동전기를 이용한 슬러지 탈수에 관한 연구)

  • Kim, Ji Tae;Won, Se Yeon;Cho, Won Cheol
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.26 no.6B
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    • pp.661-667
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    • 2006
  • In this study, an experiment of sewage sludge dewatering is carried by using electrokinetic method, and the electrokinetic dewatering efficiency of digested sludge is analyzed. Digested sludge without coagulants is selected and gravitational and pressing dewatering methods are applied in combination with electro-osmotic and electro-osmotic pulse technology. After the test of digested sludge, dewatering test of thickened sludge is carried to evaluate the electrokinetic dewatering feasibility of thickened sludge. Under the condition of constantly applied voltage, however, electrical resistance increases with decreasing of water content so that dewatering rate decreases with time. To reduce such a hindrance caused by constantly applied voltage, electro-osmotic pulse technology which is considered to reduce the difference of water content with height, is applied. For the application of electro-osmotic pulse, the dewatered flow rate and the dewatered volume became more increasing from the middle of the dewatering process than that of continuous voltage. Through the test of thickened sludge, electro-osmotic dewatering combined with gravitational and expression also showed high dewatering rate, which proved the possibility of using electrokinetic dewatering.

Load Transfer on Pulsed Power Discharge Anchors (펄스방전 확공형 앵커의 하중전이에 관한 연구)

  • Kim, Sung-Kyu;Kim, Nak-Kyung;Kim, Jae-Won;Joo, Yong-Sun;Kim, Sun-Ju
    • Proceedings of the Korean Geotechical Society Conference
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    • 2010.03a
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    • pp.832-839
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    • 2010
  • The pulse discharge anchor is a method to increase the capacity of anchors using electric discharge geotechnical technologies, which is also known as pulse discharge and electric-spark technologies. The pulse discharge anchor has bulbed bond length that is expanded by high voltage electrokinetic pulse energy. 24 anchors were installed in the weathered soil and sandy clay at the Geotechnical Experimentation Site at Sungkyunkwan University in Suwon, Korea and attached strain gauge at 10 anchors. The numerical predictions by Beam-Column analysis were compared with observed measurements in a field load test.

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Pull-out Test of Pulse Powered Underreamed Anchors (펄스방전 확공형 앵커의 현장시험)

  • Kim, Nak-Kyung;Ju, Yonh-Sun;Kim, Sung-Kyu;Seo, Hyo-Kyun;Kim, Tae-Hun
    • Proceedings of the Korean Geotechical Society Conference
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    • 2008.10a
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    • pp.1014-1021
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    • 2008
  • Ground anchor should not be used in soft clay, because anchor resistance can not be guaranteed. However, there is a way to increase the capacity of anchors. The pulse powered anchor is an underreamed anchor by using high voltage electrokinetic pulse energy. In this paper, conceptual introduction of the pulse powered anchor was presented. Anchor pull-out tests were performed at the Geotechnical Experimentation Site at Sungkyunkwan University in Suwon, Korea. Data were analyzed in order to verify the performance of pulse powered anchors.

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Expansion Ratio of Pulse Power Underreamed Anchor (펄스방전 그라운드 앵커의 확공 특성에 관한 연구)

  • Kim, Nak-Kyung;Ju, Yonh-Sun;Kim, Sung-Kyu;Seo, Hyo-Kyun;Kim, Sun-Ju
    • Proceedings of the Korean Geotechical Society Conference
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    • 2009.03a
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    • pp.1107-1112
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    • 2009
  • Ground anchor should not be used in soft clay, because anchor resistance can not be guaranteed. However, there is a way to increase the capacity of anchors. The pulse powered anchor is an underreamed anchor by using high voltage electrokinetic pulse energy. In this study, a series of field test were carried out in order to find expansion rate related in number of pulse charge. and Anchor pull-out tests were performed at the Geotechnical Experimentation Site at Sungkyunkwan University in Suwon, Korea. Data were analyzed in order to define a relation between expansion rate and ultimate pullout load.

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Expansion Ratio and Ultimate Load of Pulse-Discharge Bulbed Anchors (펄스방전 그라운드 앵커의 확공특성 및 극한인발력에 관한 연구)

  • Kim, Nak-Kyung;Kim, Sung-Kyu;Joo, Yong-Sun;Seo, Hyo-Kyun;Kim, Sun-Ju
    • Journal of the Korean Geotechnical Society
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    • v.25 no.7
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    • pp.5-10
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    • 2009
  • The ground anchor is not usually used in soft clay and loose sand, because the pullout resistance of anchors can not be guaranteed. However, there is a method to increase the capacity of anchors using electric discharge geotechnical technologies, which are also known as pulse discharge and electric-spark technologies. The pulse-discharge anchor has a bulbed (or underreamed) bond length that is expanded by high voltage electrokinetic pulse energy. 24 anchors were installed in the weathered soil and sandy clay at the Geotechnical Experimentation Site at Sungkyunkwan University in Suwon, Korea. In this study, in order to define a relation between expansion rate of the anchor diameter and ultimate load, anchor load tests were carried out in accordance with testing procedures by AASHTO (AASHTO 1990) and FHWA (Weatheb 1998). And then several anchors were exhumed to measure the diameter of the pulse discharge anchors.

Application of a Pulse Electric Field to Cross-flow Ultrafiltration of Protein Solution

  • Kim, Hyong-Ryul;Lee, Kisay
    • Biotechnology and Bioprocess Engineering:BBE
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    • v.4 no.1
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    • pp.46-50
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    • 1999
  • The application of pulsed electric field was investigated in the crossflow ultrafiltration of BSA (bovine serum albumn) to economize the application time of electric current as well as to avoid inherent problems of long-term application of electric field. During the application of various cyclic patterns of pulsed electric current, the averaged filtration flowrate and the degree of concentration were maintained higher than those obtained in the absence of electric current application. The temperature increase, pH change, and BSA loss by electrodeposition were all negligible during the operation. The averaged filtration flowrate increased as the ON/OFF duration ratio of electric current was higher and as the period of ON/OFF cycle was shorter. The re-establishment of concentration polarization was dependent to the duration of current OFF state and, therefore, a longer duration of OFF state was not favorable in maintaining higher filtration flow rate. Although the averaged filtration flowrate was enhanced as the magnitude of electric current increased, the flowrate enhancement became smaller as the magnitude of current value above which the degree of electrokinetic depolarization is no further improved.

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