• 한국환경과학회지
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• 제12권12호
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• pp.1255-1260
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• 2003

Plasma-photocatalytic oxidation process was applied in the decomposition of Triethylamine(TEA) and Methyl ethyl ketone(MEK). Plasma reactor was made entirely of pyrex glass and consists of 24mm inner diameter, 1,800mm length and discharge electrode of 0.4mm stainless steel. And initial concentrations of TEA and MEK for plasma-photocatalytic oxidation are 100 ppm. Odor gas samples were taken by gas-tight syringe from a glass sampling bulb which was located at reactor inlet and outlet, and TEA and MEK were determined by GC-FID. For plasma process, the decomposition efficiency of TEA and MEK were evaluated by varying different flowrates and decomposition efficiency of TEA and MEK increased considerably with decreasing treatment flowrates. For photocatalytic oxidation process, also the decomposition efficiency of TEA and MEK increased considerably with decreasing treatment flowrates. The decomposition efficiency of MEK was 57.8％, 34.2％, 18.8％ respectively and the decomposition efficiency of TEA was reached all 100％. This result is higher than that of plasma process only, From this study, the results indicate that plasma-photocatalytic oxidation process is ideal for treatment of TEA and MEK.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2004년도 춘계학술대회 논문집
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• pp.227-232
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• 2004

선박에서 발생되는 밸러스트수를 처리하기 위하여 수중에 포함되어 있는 미생물을 북극전해처리시스템을 이용하여 살균처리 하였다. 전해처리시스템에 유입되는 시료는 정량펌프를 사용하여 상향류로 전극판 사이를 통과하도록 하였으며, 반응시간별로 유량을 조절하여 체류시간을 다르게 하였다. 양극판은 티타늄에 이산화이리듐을 전착한 Ti／IrO$_2$ 극판으로 하였으며, 음극판은 스테인리스 스틸판을 사용하였다. 전원공급은 최대 전압이 250V, 전류가 100Amper의 맥류가 전혀 없는 트랜지스트 평활회로를 사용한 D.C. Power Supply를 사용하여 전류밀도를 조절하여 운전하였다. 반응시간에 따라 전류밀도를 0.1~l.0A사이로 변화를 주어 실험한 결과 5초 이내에 대부분의 미생물이 사멸됨을 확인 할 수 있었고 연구결과를 통하여 발라스트수 처리에 적용 가능한 기술임을 알 수 있었다.

• 한국재료학회지
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• 제17권6호
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• pp.313-317
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• 2007

In-situ micro-channeled multi tubular solid oxide fuel cell(SOFC) was fabricated using multi-pass extrusion process with out side diameter of 2.7 mm and active length of 5 mm that contained 61 individual cells. Cell materials used in this work were NiO-YSZ (50 : 50 vol.%), 8 mol% yttria-stabilized zirconia(8YSZ), $La_{0.8}Sr_{0.2}MnO_3(LSM)$ as anode, electrolyte, and cathode, respectively. The arrangement of each electrode and electrolyte layer in green bodies showed uniformity and integrity after extrusion and sintering. The XRD analysis confirmed that no reaction phases appeared and the microstructure of the electrolyte was fairly dense (relative density > 96%) after sintering.

• Journal of Electrochemical Science and Technology
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• 제5권4호
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• pp.115-127
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• 2014

Cd-Pb thin films were electrodeposited from a diluted chloride solution using stainless steel rotating disc electrode. The linear sweep voltammograms of the single metallic ions show that electrodeposition of these ions was mass transfer control due to the plateau observed for different rotations at concentration (50 and 200 ppm). The voltammograms of binary system elucidate that electrodeposition process always start at cathodic potential located between the potential of individual metals. Currents transients measurements, anodic linear sweep voltammetry (ALSV) and atomic force microscopy (AFM) were used to characterize the electrocryatalization process and morphology of thin films. ALSV profiles show a differentiation for the dissolution process of individual metals and binary system. Two peaks of dissolution Cd-Pb film were observed for the binary system with different metal ion concentration ratios. The model of Scharifker and Hills was used to analyze the current transients and it revealed that Cd-Pb electrocrystalization processes at low concentration is governed by three-dimensional progressive nucleation controlled by diffusion, while at higher concentration starts as a progressive nucleation then switch to instantaneous nucleation process. AFM images reveal that Cd-Pb film electrodeposited at low concentration is more roughness than Cd-Pb film electrodeposited at high concentrated solution.

• 한국생산제조학회지
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• 제20권2호
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• pp.180-186
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• 2011

This paper describes a micro electrical discharge machining (MEDM) technique that uses an insulated tool in combination with ultrasonic vibration to drill micro holes. As the machining depth becomes deeper, the dispersion of debris and circulation of the dielectric fluid are difficult to occur. Consequently, machining becomes unstable in the machining region and unnecessary electrochemical dissolution and secondary discharge sparking occur at the tool side face. To reduce the amount of unnecessary side machining, an insulated tool was used. Ultrasonic vibration was applied to the MEDM work fluid to better remove debris. Through these methods, a $1000\;{\mu}m$ thick stainless steel plate was machined by using a $73\;{\mu}m$ diameter electrode. The diameters of the hole entrance and exit were $96\;{\mu}m$ and $88\;{\mu}m$, respectively. It took only 351s to completely drill one hole.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2007년도 하계학술대회 논문집 Vol.8
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• pp.462-463
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• 2007

SF6 widely used as insulating gas is rising as the environment problem. For decreasing this greenhouse gas, electrical breakdown characteristics of composite insulation composed of epoxy resins with N2, air are studied in non-uniform field. The gap of needle to plane was 3mm, 5mm. The pressure of air, nitrogen was varied within the range of 0.1~0.6MPa. The thickness of a needle is 1mm and the curvature radius of the end of needle is 100um. The diameter of a plane made of the stainless steel is 50mm. As a result of the experiment, the breakdown voltage is increased about 3 times when epoxy resins is composited. The thickness of epoxy resins filled opposite to electrode concentrated electric field weakly influences on breakdown voltage.

• Journal of Electrochemical Science and Technology
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• 제14권1호
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• pp.15-20
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• 2023

Ionic liquids are considered as a promising, alternative solvent for the electrochemical synthesis of metals because of their high thermal and chemical stability, relatively high ionic conductivity, and wide electrochemical window. In particular, their wide electrochemical window enables the electrodeposition of metals without any side reaction of electrolytes such as hydrogen evolution. The electrodeposition of silver is conducted in 1-n-butyl-3-methylimidazolium chloride ([C4mim]Cl) ionic liquid system with a silver source of AgCl. This study is the first attempt to electrodeposit silver nanoparticles without using co-solvents other than [C4mim]Cl. Pulse electrolysis is employed for the synthesis of silver nanoparticles by varying applied potentials from -3.0 V to -4.5 V (vs. Pt-quasi reference electrode) and pulse duration from 0.1 s to 0.7 s. Accordingly, the silver nanoparticles whose size ranges from 15 nm to ~100 nm are obtained. The successful preparation of silver nanoparticles is demonstrated regardless of the kinds of substrate including aluminum, stainless steel, and carbon paper in the pulse electrolysis. Finally, the antimicrobial property of electrodeposited silver nanoparticles is confirmed by an antimicrobial test using Staphylococcus aureus.

• 한국수소및신에너지학회논문집
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• 제9권4호
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• pp.169-176
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• 1998

Ni/MH 2차전지의 음극용 금속간화합물전극의 부식특성에 미치는 합금원소와 결합제의 영향을 조사하였다. 전극의 재료는 $(LM)Ni_{4.49}Co_{0.1}Mn_{0.205}Al_{0.205}$와 $(LM)Ni_{3.6}Co_{0.7}Mn_{0.3}Al_{0.4}$의 $AB_5$ type합금을 모재로 하였다. 여기에 Si sealant 또는 PTFE를 결합제로 첨가한 것과 원재료 분말에 구리를 20% 무전해도금한 것을 냉간 압착하여 전극을 제조하였다. 부식특성을 조사하기위해 탈공기된 6M의 KOH 용액에서 동전위법과 순환전위법을 이용하여 부식전류와 전류밀도를 측정하였다. 모재에 Co가 많이 함유되면 전극의 내식성을 향상시키고 Ni이 많이 함유되면 충전과 방전을 반복하는 동안에 전극의 안정성을 저하시켰다. 부식전류밀도는 Si sealant를 결합제로 사용한 전극의 경우가 PTFE를 사용한 전극의 경우보다 낮았고 Cu가 도금된 전극은 내식성에서 가장 우수하게 나타났다.

• 한국지하수토양환경학회지:지하수토양환경
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• 제8권3호
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• pp.56-60
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• 2003

전기분해에 의한 부상현상을 이용하여 유류로 오염된 토양 세정 후 발생되는 유출수 중 유분 등을 분리하기 위한 적정 운전조건을 찾고자 하였다. 전기분해 반응조(200${\times}$10${\times}$15cm)를 이용하여 혼합계면활성제($POE_5$ : $POE_{14} $, 1:1) 1%용액에 디젤을 1,000 mg/L 농도로 용해시켜 실험하였다. 양극에는 티타늄 코팅전극, 음극으로는 스테인레스 스틸전극을 이용하였다. 반응시간은 62분(반응 :60분, 부상시간 :2분)이었으며 전압은 6V였다. 전해질 첨가에 의한 영향을 알아보기 위하여 실험한 결과, 전해질을 첨가하였을 경우 첨가하지 않았을 때보다 40% 정도의 효율이 증가하였다. 적정 전해질, 주입농도 및 반응시간을 알아보기 위하여 1N NaCl과 NaOH의 농도를 변화시켜 가면서 실험하였다. NaCl의 경우 더 좋은 효율을 나타내었다. 전해질의 농도는 0.2-1.0%의 농도범위에서 NaCl와 NaOH 모두 농도에 따라 순차적으로 효율이 증가하였다. 두 전해질 모두 0.4-1.0% 농도 범위에서 평형에 도달하는 시간은 20분으로 나타났다.

• 한국항해항만학회지
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• 제28권10호
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• pp.955-960
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• 2004

선박에서 발생되는 밸러스트수를 전처리하기 위하여 수중에 포함되어 있는 미생물을 복극전해처리시스템을 이용하여 살균처하였다. 전해처리시스템에 유입되는 시료는 정량펌프를 사용하여 상향류로 전극판 사이를 통과하도록 하였으며, 반응시간별로 유량을 조절하여 체류시간을 다르게 하였다. 양극판은 티타늄에 이산화이리듐을 전착한 Ti/Ir02 극판으로 하였으며, 음극판은 스테인리스 스틸판을 사용하였다. 전원공급은 최대 전압이 250V, 전류가 100Amper의 맥류가 전혀 없는 트랜지스트 평활회로를 사용한 D.C. Power Supply를 사용하여 전류밀도를 조절하여 운전하였다. 반응시간에 따라 전류밀도를 0.1$\~$1.0A사이로 변화를 주어 실험한 결과 5초 이내에 E. coli, Bacteria, Bacillus sp.의 미생물이 사멸됨을 확인할 수 있었고, 전극간격은 75mm, 전류밀도 2.0A/dm2, 체류시간을 5초로 하였을 때 제거율이 $90\%$이상이였다. 연구결과를 통하여 밸러스트수 처리에 적용 가능한 기술임을 알 수 있었다.