• 한국수소및신에너지학회논문집
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• 제27권2호
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• pp.176-181
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• 2016

Recent years, supercapacitors have been attracting a growing attention as an efficient energy storage, due to their long-lifetime, device reliability, simple device structure and operation mechanism and, most importantly, high power density. Along with the increasing interest in flexible/stretchable electronics, the supercapacitors with compatible mechanical properties have been also required. A eutectic gallium-indium (EGaIn) liquid metal could be a strong candidate as a soft electrode material of the supercapacitors because of its insulating surface oxide layer for electric double layer formation. Here, we report the electrochemical study on the charging/reaction process at the interface of EGaIn liquid metal and electrolyte. Numerical fitting of the charging current curves provides the capacitance of EGaIn/insulating layer/electrolyte (${\sim}38F/m^2$). This value is two orders of magnitude higher than a capacitance of a general metal electrode/electrolyte interface.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2007년도 하계학술대회 논문집 Vol.8
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• pp.428-428
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• 2007

In this study, It was studied about the luminance characteristics of 17inch direct-type back light using EEFL(External Electrode Fluorescent Lamp). EEFI has a long life time because the electrode is installed outside of lamp. And it is produced low price than conventional CCFL. It does not need process of installing internal electrode. But EEFL technology has several problems such as difficulty of design driving inverter, and prevents leckage current along the skin of lamps. Therefore, by the optimizing of inverter properties, 7525 nit center luminance was acquired in almost same power consumption condition. It was almost same luminance in CCFL backlight unit. And it was operated stably in low operating temperature such as the value of $40^{\circ}C$, so that it was adopted in conventional LCD-TV application.

• Nuclear Engineering and Technology
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• 제45권4호
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• pp.523-528
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• 2013

The beam position monitor (BPM) is an essential component for the PEFP 100-MeV linac's commissioning. A prototype stripline-type linac BPM was designedfor this purpose. The electrode aperture is 20 mm in diameter, and the electrode is 25 mm long, so it can be installed between Drift Tube Linac (DTL)101 and DTL102, which is the shortest distance. One end of the electrode is connected to the Sub Miniature Type A (SMA) feed through for signal measurement, and the other end is terminated as a short. The signal amplitude of the fundamental component was calculated and compared with that of the second harmonic component. The designed BPM was fabricated and a low-power RF test was conducted. In this paper, the design, fabrication and low power test of the BPM for the PEFP linac are presented.

• Journal of Electrochemical Science and Technology
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• 제10권2호
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• pp.131-138
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• 2019

To improve the performance of Si anodes in advanced Li-ion batteries, the design of the electrode plays a critical role, especially due to the large volumetric expansion in the Si anode during Li insertion. In our study, we used a simple fabrication method to prepare Si-based electrodes by grafting polyacrylic acid (PAA) to a carboxymethyl cellulose (CMC) binder (CMC-g-PAA). The procedure consists of first mixing nano-sized Si and the binders (CMC and PAA), and then coating the slurry on a Cu foil. The carbon network was formed via carbonization of the binders i.e., by a simple heat treatment of the electrode. The carbon network in the electrode is mechanically and electrically robust, which leads to higher electrical conductivity and better mechanical property. This explains its long cycle performance without the addition of a conducting agent (for example, carbon). Therefore, the partially carbonized CMC-g-PAA binder presented in this study represents a new feasible approach to produce Si anodes for use in advanced Li-ion batteries.

• Journal of information and communication convergence engineering
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• 제20권1호
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• pp.49-57
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• 2022

Fertilizers have long been used to increase crop yields; however, farmers are still having difficulties in managing fertilizers for growing crops as well as economic problems. The conventional method of soil sampling and laboratory analysis to determine soil pH is time consuming and costly; therefore, a portable pH sensor is developed to characterize spatial or temporal variability within fields via rapid and dense data acquisition. The portable pH sensor comprises an electrode unit, a portable console, and a USB connector. The soil water content (SWC) and electrical conductivity (EC) affect the electrical resistance of soil. An artificial test soil is performed to evaluate the effect of SWC and EC on soil pH. The test results show that stable pH measurements are achieved at SWCs greater than 20 mL (16.3%). Regardless of the SWC, the electric potential difference (EPD) remains at 2.5 g of NaCl. As the EC increases in the soil samples, the EPD increases.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1995년도 추계학술대회 논문집 학회본부
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• pp.453-455
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• 1995

In electrostatic airclean filter, the collection efficiency defends on particle charge in the ionizer section. The effect of electrostatic airclean filter condition (deposition of dust, variation of corona discharge current) on corona discharge characteristics was well studied. However, it seems not to be studied on corona discharge characteristics of electrostatic airclean filter respect to contaminated electrode which is caused by practical use. In this paper, Long-term(60days) effects are studied experimentally by two methods. The one is ozone concentration, the other is collection efficiency. Generation of ozone level was increased but collection efficiency was slightly reduced in long-term used electrostatic airclean filter.

• 전기화학회지
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• 제4권3호
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• pp.87-93
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• 2001

외부 Ag/AgCl 기준 전극은 가압형 및 비등형 경수로 환경에 널리 사용되었다. 전극의 채움 용액 (Siting solution)으로 통상 KCl을 사용하는데, 다공성 지르코니아로 만들어지는 플러그를 통한 Cl 이온의 누설이 전극의 전위차 변동을 유발하는 문제가 있다. 누설로 인한 전위차 변동의 문제를 해결하기 위해 채움 용액으로 순수를 사용하였다 순수를 사용하는 경우 상온에서의 AgCl용해도에 의해 Cl이온의 농도가 결정된다. 붕산과 수산화리튬 혼합용액으로 $288^{\circ}C$에서 전극의 안정성 실험을 실시하였다. 약 일주일간 전위차 변화는 10mV 이내였으며, $288^{\circ}C$와 $240^{\circ}C$에서의 온도 사이클링 시험 전후의 전위차 변화는 15mV 이내였다. 이온의 limiting equivalent conductances와 Agar의 수역학적 이론을 토대로 하여 전극의 TLJP을 계산하였다. 전극 채움 용액 내의 Cl이온 농도를 상온에서 측정한 값으로 보정하여 이론값을 계산할 경우, 실험값과 비교적 잘 일치하는 것을 알 수 있었다.

• 한국지반환경공학회 논문집
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• 제17권1호
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• pp.13-19
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• 2016

연약한 점토지반에 대규모 토목시설을 건설하기 위해서는 연약지반 안정화 처리가 불가피하다. 일반적으로 연약지반 안정화 처리를 위해 압밀촉진공법으로 선행재하공법이 사용되고 있으나 선행재하공법은 공사기간이 매우 길고, 재하용 성토재료를 확보해야 하는 단점이 있기 때문에 이를 해결하기 위한 방법으로 전기삼투공법 등이 사용되고 있다. 전기삼투공법은 금속성 전극재가 사용되기 때문에 시공 및 경제적 측면에서 불리하다. 따라서 금속성 전극재를 대신하기 위해 기존 플라스틱 드레인 보드(PBD)에 전기를 공급할 수 있도록 나노기술을 이용한 플라스틱 전극재가 개발되었다. 이에 본 연구에서는 플라스틱 전극재의 간격에 따른 연약지반의 개량 효과와 전기적 특성을 확인하기 위한 모형실험을 수행하였으며, 그 결과 지반개량 효과는 전극간 거리가 길수록 최대 49% 감소하였고 전기적 특성은 전극간 거리에 따른 압밀침하에 영향을 받는 것으로 나타났다.

• 대한의용생체공학회:의공학회지
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• 제28권1호
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• pp.17-23
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• 2007

Long-term potentiation (LTP) of synaptic transmission is the most widely studied model for learning and memory. However its mechanisms are not clearly elucidated and are a subject for intense investigation. Previous attempts to decipher cellular mechanisms and network properties involved a current-source density analysis (CSDA) of the LTP from small animal hippocampus measured with a limited number of microelectrodes (typically <3), only revealing limited nature of spatiotemporal dynamics. Recent advancement in multi-electrode array (MEA) technology allows continuous and simultaneous recordings of LTP with more than 60 electrodes. However CSDA via the standard Laplacian transform is still limited due to its relatively high sensitivity toward noise, inability of resolving overlapped current sources and sinks, and its requirement for tissue conductivity values. In this study, we propose a new methodology for improved CSDA. Independent component analysis and its joint use (i.e., Joint-ICA) are applied to extract spatiotemporal components of LTP. The results show that ICA and Joint-ICA are capable of extracting independent spatiotemporal components of LTP generators. The ICs of LTP indicate the reversing roles of current sources and sinks which are associated with LTP.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제49권12호
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• pp.679-684
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• 2000

Closing switch, key component of pulsed power system, is constructed simply and used frequently due to the easy control and manufacture of one. The kind of one are spark-gap, triggered vacuum switch, pseudo-spark switch and INPIStron. But the electrode of spark gap switch is damaged with the hot spot by Z-pinch and then the life of one become short. INPIStron with inverse pinch effect has long life but it is difficult trigger system to provide uniform discharge between cathode and anode. In this paper, the design and manufacturing of INPIStron with gas puffing trigger method in order to supply uniform discharge inter-electrode and the performance of the developed INPIStron applied to 500[kA]-2[MJ] pulsed power system is presented.