• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2001년도 The 6th International Symposium of East Asian Resources Recycling Technology
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• pp.443-447
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• 2001

A laboratory-scale electrodewatering system for enhancing conventional filter pressure dewatering by an electric field has been developed to decrease the water content of sludge generated in the wastewater treatment. It consists of a piston-typed filter press, a power supply and data acquisition system. The offset of electrodewatering is investigated as a function of applied pressure, applied voltage, sludge type and filtration time. Also the optimal conditions for maximizing the dewatering efficiency in the eletrodewatering system are investigated. Electric field strength and mechanical pressure are in the range of from 0 to 120 V/cm and from 98.1 to 392.4 kPa. The dewatering rates increased with increasing electric strength. These experiments produced a final sludge cake with water content of 60 wt% using electrodewatering technology, compared with a 80 wt% using pressure filtration alone. The conventional filtration system using the electrodewatering shows the potential to be effective method for improving dewatering Sludge.

• 대한기계학회논문집B
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• 제33권6호
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• pp.411-417
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• 2009

The transient shear stress response of an electrorheological fluid is investigated experimentally. The characteristic time constants of an electrorheological fluid sheared between two concentric cylinders were obtained under various electric field strengths and shear rates. Also, two experimental modes are adopted to investigate the effect of the shear flow on the dynamic behavior of the fluid; one is that the electric field is induced before shearing, and the other is the electric field is induced after shearing. From the difference in the response time between two modes, the cluster formation time were obtained. The response times were decreased with the increase of the shear rate, irrelatively of the electric field strength. The cluster formation time were monotonically increased with increase of shear rate, and thereafter, were converged with a certain value.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2013년도 제44회 동계 정기학술대회 초록집
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• pp.219-220
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• 2013

The phenomenology of liquid breakdown has been an area of interest for many years but is still not fully understood. Moreover, it was known that the behavior of magnetic nanoparticles in transformer oil could affect the dielectric breakdown voltage positively or negatively. In this study, we have imaged the magnetic nanoparticles in a transformer oil in-situ using an optical microscopic set-up and a microchannel according to the electric and magnetic fields applied. And we have calculated numerically dielectrophoresis and magnetophoresis forces, which must be the driving mechanisms to move magnetic nanoparticles in the fluid. It was found that when the electric field is applied the magnetic nanoparticles in the fluid experience an electrical force directed toward the place of maximum electric field strength. And when the external magnetic field is applied, the magnetic nanoparticles form long chains oriented along the direction of the field.

• Journal of the Optical Society of Korea
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• 제16권1호
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• pp.47-52
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• 2012

The use of a $Ti:LiNbO_3$ symmetric Mach-Zehnder interferometric intensity modulator with a push-pull lumped electrode and a plate-type probe antenna to measure an electric field strength is described. The modulator has a small device size of $46{\times}7{\times}1mm$ and operates at a wavelength of $1.3{\mu}m$. The output characteristic of the interferometer shows the modulation depth of 100% and 75%, and $V_{\pi}$ voltage of 6.6 V, and 6.6 V at the 200 Hz and 1 KHz, respectively. The minimum detectable electric field is ~1.84 V/m, ~3.28 V/m, and ~11.6 V/m, corresponding to a dynamic range of about ~22 dB, ~17 dB, and ~6 dB at frequencies of 500 KHz, 1 MHz and 5 MHz, respectively.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2009년도 9th International Meeting on Information Display
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• pp.625-628
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• 2009

In the bistable chiral splay nematic (BCSN) mode, the splay and ${\pi}$ twist states are used for the two stable states. The switching property is strongly dependent on the amplitude of the electric field. In this paper, we investigated the gray scale capability of BCSN liquid crystal display (LCD) by the gradual horizontal electric field caused the interdigital electrode of by the inequality gap. We demonstrate the gray scale of the BCSN LCD during transition process under the horizontal electric field.

• 한국식품영양학회지
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• 제5권2호
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• pp.77-83
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• 1992

The optimum conditions and mechanisms for the plasmid-mediated genetic transformation of intact cells of Bacillus brevis Pl76-2, an extracellular protein producing bacterium by electroporation were investigated. It was found that pUB110 Plasmid DNA can be introduced into intact bacterial cells by electroporation. The frequency of transformation by this electroporation system depended upon the initial electric field strength, the capacity of the electric discharge capacitor, growth stage, number of successive pulses and composition of electroporation buffer. It was effective for transformation that cells were harvested, washed and resuspended with HSM [7M HEPES(PH 7.4), 272mM sucrose, 1 mM MgCl2] electroporation buffer when cell growth was attained to 1.2 at OD660. A maximum frequency of transformation of 2.40$\times$104 transformants per$\mu$g plasmid DNA was obtained by two succesive Pulses with an initial electric field strength of 12.5kV/cm and with a capacitance of 7.3uF.

• 대한기계학회논문집B
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• 제23권3호
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• pp.299-310
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• 1999

Effect of electrostatic and inertial forces on the pre-charged particle deposition was theoretically and experimentally studied by introducing the inertia impactor subjected to an electric field. To derive the analytic solution, we assumed that a flow was an ideal stagnation flow, a particle had saturation charges, and the electric field within the test section was uniform. On the other hand, $Al_2O_3$ particle groups were used as the test particles, which mean sizes were $1{\mu}m$, $3{\mu}m$, and $5{\mu}m$. To measure the deposition efficiency, the light scattering method was used. The results showed that the deposition efficiency was minimized at a certain nozzle velocity as increasing the nozzle velocity, only if the electric force was applied. As the electric field strength increased, $Stk_{50}{^{1/2}}$ was decreased, and its decreasing rate was reduced with increasing the flow velocity. Moreover the existence of electric field was against the cut-off performance of the inertia impactor.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1994년도 추계학술대회 논문집 학회본부
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• pp.270-273
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• 1994

The capacitive current breaking capability as well as the short circuit current breaking capability is a very important factor in the performance of a circuit breaker. The dielectric recovery capability between poles should be considered in the desist of a circuit breaker because approximately two times of the maximum power system voltage might be applied between poles after the capacitive current be interrupted. The electric field and flow field analyses were utilized in the calculation of dielectric recovery characteristics between poles of 800kV model interrupter. The results show that the separation between moving main contact and moving arcing contact will affect to decrease significantly the electric field strength of a moving arcing contact and an insulation cover, to increase slightly the electric field strength of a fixed arcing contact and to decrease consequently the dielectric recovery capability between poles of the interrupter.

• 폴리머
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• 제27권3호
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• pp.195-200
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• 2003

알지네이트는 곁사슬에 강한 음이온을 가지고 있어 전기장 하에서 구동 특성을 발현할 수 있다. 본 연구에서는 가교제로 CaCl$_2$를 사용하여 가교 알지네이트 필름을 제조하였고, 제조된 필름의 열적 특성, 기계적 특성 및 전기적 구동 특성을 열중량 분석, 인장 강도 실험 및 전기응답 실험을 통하여 조사하였다. 가교제의 농도가 증가함에 따라 필름의 초기 분해 온도와 인장 강도가 증가하였다. 또한 팽윤비는 사슬 내 자유부피와 정전기적 반발력에 기인하여 가교제 농도의 감소와 pH가 증가함에 따라 증가하였다. 저기 자극에 의하여 알지네이트 필름은 유연한 물리적 거동을 발현하였다. 전기장에서 전압, 이온 강도 및 저해질 용액의 종류에 따라서 필름의 응답 속도 띤 거동에 영향을 주었다. 가교제의 농도가 5 wt%일 때 가장 좋은 굽힘 거동과 반복 회복성을 보였으며, NaCl과 KCl 전해질 용액의 이온 강도가 0.1 M일 때 가장 높은 전기 반응성을 나타냈다. 또한 전압이 증가됨에 따라 전하의 이동이 활발해지고 따라서 굽힘 거동이 증가하였다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1996년도 하계학술대회 논문집 C
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• pp.1585-1587
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• 1996

The dielectric properties of DGEBA/MDA/GN system under inhomoneous electric field were investigated. As GN contents increased, impact strength increased, but dielectric breakdown strength decreased. At $150^{\circ}C$, the dielectric breakdown strength decreased and uniformly maintained with the increment of distance between two electrodes. The life-time of epoxy resin increased with the decrement of applied voltage, but dielectric breakdown didn't occur below specific applied voltage.