• 전기의세계
• /
• v.14 no.3
• /
• pp.37-40
• /
• 1965

전기기구의 절연성을 향상시킨다는 것은 품질이나 수명을 향상시키는것과 똑같은 의의를 갖는 것이며, 따라서 기기의 수명은 절연성에 있다해도 과언이 아니다. 절연내력을 높이기 위해서는 질량의 절연재료와 고도의 절연가공기술 및 절연구조의 개량등의 요건을 필요로 하나 건조 처리기술에 의하여도 상당히 전기특성을 회복시킬수 있다. 주지의 사항과 같이 건조 처리법에는 열풍건조법, 열유(분무 및 순환) 건조법증기건조법, 전류건조(냉상전류법 및 단락순환건조법)법, 등등에 진공건조를 병용한 처리법이 있으며 어떤나라의 전력계통에서도 계통의 감시 또는 정기보수시 전력용 변압기를 건조(현지)해야 되는 작업은 기기 maker에서 공장건조해야 되는것과 똑같이 거쳐야 하는 공정중의 하나인 것이다. 여기서 언급코져 하는 변압기 tank 유도가열법은 본인이 일본 삼릉전기에서 연수중 조사한 바 있는것으로서 소련, 일본등지에서는 벌써부터 타 건조처리법과 병용해서 척용하고 있으며, 보유하고 있는 건조실의 size가 적을때나 또는 수송 제한조건때문에 현지 조립을 요하는 지역에서는 편리한 처리법의 하나라 할 수 있다. 이하 그 설계 계산법과 설계예를 간략한다.

• 한국전기화학회:학술대회논문집
• /
• 2000.04a
• /
• pp.30-30
• /
• 2000

• Journal of the Korean Chemical Society
• /
• v.38 no.10
• /
• pp.734-740
• /
• 1994

Electrochemical determination of Ag(I) ion was carried out by cyclic voltammetry (CV) and differential pulse voltammetry (DPV) with the carbon paste electrode (CPE) containing cinchonidine. The detection limit for Ag(I) ion was shown to be $1.0 {\times}10^{-6}$ M in conventional CV and up to $8.0{\times}10^{-9}$ M (${\pm}$0.6%) using DPV. The optimum analytical condition of Ag(I) ion was determined as follows: pH 7, 20 minutes of deposition time, and 50% (w/w) cinchonidine to carbon powder composition of electrode. The interference effect of various metal ions added to the deposition solution was also studied. The peak current of Ag(I) ion except Hg(II) ion was decreased roughly 25% compare to Ag(I) ion only. When Mn(II) ion was present in sample solution at pH 9, shown a large interference effect.

• Journal of the Korean Chemical Society
• /
• v.37 no.4
• /
• pp.462-469
• /
• 1993

The electrocatalytic reduction of dioxygen is investigated by cyclic voltammetry and chronoamperometry at glassy carbon electrode and carbon microelectrode coated with a variety of cobalt phenylporphyrins. The n value obtained at carbon microelectrode is slightly different from that determined at glassy carbon electrode. Dioxygen reduction catalyzed by the monormeric porphyrin Co(II)-TPP mainly occurs through the $2e^-$ reduction pathway resulting in the formation of hydrogen peroxide, electrocatalytic process carries out $4e^-$ reduction pathway of dioxygen to $H_2O$ at the electrodes coated with bis-cobalt phenylporphyrins. The electrocatalytic reduction of dioxygen is irreversible and diffusion controlled.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2014.02a
• /
• pp.403.2-403.2
• /
• 2014

본 연구에서는 갭을 갖는 전극을 제작하고, 전극사이의 간격이 좁아짐에 따른 분석물질의 전기화학적 신호증폭현상을 확인하였다. 광 리소그래피와 전자빔 리소그래피를 이용하여 기본 전극을 구성하고 이를 바탕으로 전극의 표면에 금속의 환원을 유도함으로써 환원시간에 따라 전극이 점점 좁아지게 하는 방법을 이용하여 다양한 간격의 갭 전극을 제작하였다. 이와같은 방법으로 제작된 전극을 전기화학 신호분석장치에 연결하고, $2{\mu}m$의 간격부터 약 50 nm 까지의 다양한 전극 간격을 가지는 갭 전극 각각에 대한 전기화학적 신호를 분석하였다. 전극에 Ferricyanide 를 노출시켜 전극의 간격이 좁을수록 FeCN63-의 산화 환원에 따른 패러데이 전류가 증폭하는 것을 확인하였으며, 분석물질의 검출 한계 농도 또한 낮아짐을 확인하였다. 이러한 실험결과는 일정전위기의 순환전압전류법, 주사전자현미경, 원자힘현미경을 이용하여 분석되었다.

• Journal of the Korean Applied Science and Technology
• /
• v.30 no.4
• /
• pp.754-760
• /
• 2013

We investigated an electrochemical properties for Langmuir-Blodgett (LB) monolayer films of sphingomyelin(SP) and polyamic acid(PAA) mixture(1:1, 2:1 and 3:1 molar ratio). LB monolayer films of mixture was deposited by the LB method on the indium tin oxide(ITO) glass. The electrochemical properties measured by cyclic voltammetry with three-electrode system in 0.1N $KClO_4$ solution. As a result, LB monolayer films of SP and PAA mixture was appeared on irreversible process caused by the reduction current from the cyclic voltammogram. Diffusion coefficient(D) in the SP and PAA mixture was calculated $2.670{\times}10^{-5}$, $3.562{\times}10^{-5}$ and $1.005{\times}10^{-5}cm^2s^{-1}$ at 1:1, 2:1 and 3:1 molar ratio, respectively.

• Journal of the Korean Applied Science and Technology
• /
• v.32 no.4
• /
• pp.789-794
• /
• 2015

In this study, we investigated the stability with respect to the Langmuir-Blodgett(LB) monolayer films of stearic acid and phospholipid(L-${\alpha}$-dimyristoylphosphatidyl choline, DMPC) mixture. LB films of stearic acid and DMPC monolayer were deposited by the LB method on the indium tin oxide(ITO) glass. The electrochemical properties measured by cyclic voltammetry with three-electrode system in $0.05N\;NaClO_4$ solution, -0.3 V initial, 1650 mV switching potential and -1350 mV final potential. As a result, monolayer LB films of stearic acid and phospholipid mixture was appeared on irreversible process caused by the oxidation current from the cyclic voltammogram. Diffusion coefficient (D) of stearic acid and DMPC mixture(molar ratio 1:1, 1:2, 1:3) was calculated $1.4{\times}10^{-3}$, $1.7{\times}10^{-3}$ and $1.6{\times}10^{-3}(cm^2/s)$ in $0.05N\;NaClO_4$ solution, respectively.

• Journal of the Korean Applied Science and Technology
• /
• v.29 no.1
• /
• pp.88-94
• /
• 2012

In this study, the current-voltage curves for metals were measured using cyclic voltammetry. The relationship between the electrochemical properties and surface states of metals were investigated by Scanning Electron Microscope (SEM). In cyclic voltammetry, we used a 3-electrode system for the electrochemical measurements. The measurement was conducted at the condition that consists of the first reduction from the initial potential to -1350 mV, continuous oxidation to 1650 mV, and last reduction to the initial potential. The scan rates were 50, 100, 150 and 250 mV/s. The results show the C-V characteristics of metals to be for an irreversible process, which was caused by the oxidation current from cyclic voltammogram, when monoethanolamine (MEA) was used as a corrosion inhibitor. When we used MEA as a corrosion inhibitor, the diffusion coefficient was decreased as the concentration of electrolyte was increased. In the SEM images of copper, we observed an increase of surface corrosion at the increased electrolyte concentration. Addition of $1.0{\times}10^{-3}M$ corrosion inhibitor MEA reduced the effect of corrosion prevention due to the relatively large diffusion coefficient at the electrolyte concentration of 0.1N.

• Journal of the Korean Applied Science and Technology
• /
• v.30 no.1
• /
• pp.64-70
• /
• 2013

We investigated an electrochemical properties for Langmuir-Blodgett (LB) monolayer films of sphingomyelin and polyamic acid(1:1 molar ratio) mixture. LB monolayer films of mixture was deposited by the LB method on the indium tin oxide(ITO) glass. The electrochemical properties measured by cyclic voltammetry with three-electrode system in $KClO_4$ solution. The current of reduction and oxidation range was measured from 1650 mV to -1350 mV, continuously. The scan rates were 50, 100, 150, 200 and 250 mV/s, respectively. As a result, LB monolayer films of sphingomyelin and polyamic acid mixture was appeared on irreversible process caused by the reduction current from the cyclic voltammogram. Diffusion coefficient (D) in the sphingomyelin and polyamic acid mixture was calculated $2.67cm^2s^{-1}{\times}10^5$, $5.23cm^2s^{-1}{\times}10^6$ at 0.1 N and 0.2 N $KClO_4$ solutions, respectively.

• Journal of the Korean Applied Science and Technology
• /
• v.31 no.1
• /
• pp.66-73
• /
• 2014

In this work, the current-voltage curves for stainless steel in the ethanolamine solution containing alkyl group were measured using the conventional three electrodes of cyclic voltammetry. Stainless steel as working electrode, Ag/AgCl electrode as reference electrode and Pt wire as counter electrode were used respectively. As a result, the C-V characteristics of stainless steel were to be for an irreversible process due to the oxidation current from cyclic voltammogram, using N-ethylethanolamine and N,N-dimethylethanolamine solutions. Effective diffusivity of corrosion inhibitors was decreased with increasing concentration. It was found from SEM images of the metal that the electrolyte (specific name ?)(0.5 N) as corrosion inhibitor was added into a N, N-diethylethanolamine solution ($1.0{\times}10^{-3}M$) containing copper and nickel, the corrosion inhibiting effect was enhanced.