• 한국진공학회:학술대회논문집
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• 한국진공학회 2012년도 제43회 하계 정기 학술대회 초록집
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• pp.208-208
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• 2012

최근 환경문제가 많이 제기되면서 친환경적 운송수단인 자전거 개발과 관련하여 다양한 기술개발이 이루어지고 있다. 그 중 고부가가치의 서스펜션 포크의 프레임에 고기능성 표면처리로 Arc ion plating deposition system (AIPDS)을 이용하여 부식, 내마모 특성이 뛰어난 TiN 박막을 증착시켰다. AIPDS는 기존의 arc system과 달리 다원계 소재 코팅 공정조건 확립을 위하여 chamber wall에 2개의 rectangular type sputter source를 장착하고 소재의 pre-treatment 용 linear type ion source를 설치하였다. 장비의 Chamber 중앙에는 pipe형 arc cathode를 설치하였으며, 그 주위를 anode 역할을 하는 copper 코일로 감아 이는 발생한 arc를 target인 cathode 축을 중심으로 방향성을 가지고 회전하여 진행 할 수 있도록 유도 하였다. 이 시스템에서 증착된 TiN 박막은 bias 전압 변화에 따른 박막의 구조 및 물성을 평가하였다. XRD 장비를 통하여 TiN 박막의 상분석을 진행하였고, 마모테스터, 원자현미경, 마이크로 비커스 경도기 등을 이용하여 기계적 특성을 평가하였다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1999년도 추계학술대회 논문집
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• pp.617-620
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• 1999

To reduce the consumption of chemicals and ultra pure water(UPW) in cleaning process used in device manufacturing, we proposed wet processes that use electrolytic ionized water(EIW), which is generated by electrolysis of a diluted electrolyte solution or UPW and systemically investicate the EIW\`s characteristics. EIW\`s pH values are increased in cathode chamber and decreased in anode chamber according to the electrolysis time and its varied ratio is reduced with time increasement. The variation of pH and ORP is increased accordin to the applied voltage until critical voltage. But more than that voltage, the variation is decreased because of ion\`s scattering effect. When electrolyte is added, the effects of electrolysis is increased because electrolyte acts as catalyst. But when the density of electrolyte is increased more than critical value, ion\`s flowage is obstructed and the effects of electrolysis is decreased.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1989년도 추계학술대회 논문집 학회본부
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• pp.139-141
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• 1989

The characteristics of the hollow cathode discharge were investigated. Temperature distribution of the hollow cathode was investigated and I-V curves of the hollow cathode discharge were obtained. In this paper variables are chamber pressure, Ar gas flow rate injected through the cathode tube and the gap distance between cathode and anode. The inter electrode electron temperature and density were measured by Langmuir probe.

• 한국물환경학회지
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• 제26권4호
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• pp.681-686
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• 2010

Two different MFC designs were evaluated in batch mode: single compartment combined membrane-electrodes (SCME) design and twin-compartment brush-type anode electrodes (TBE) design (single chamber with two air cathodes and brush anodes at each side of the reactor). In SCME MFC, carbon anode and cathode electrodes were assembled with a proton exchange membrane (PEM). TBE MFC was consisted of brush-type anode and carbon cloth cathode electrodes without the PEM. A brush-type anode was fabricated with carbon fibers and was placed close to the cathode electrode to reduce the internal resistance. Substrates used in this study were glucose, leachate from cattle manure, or sucrose at different concentrations with phosphate buffer solution (PBS) of 200 mM to increase the conductivity thereby reduce the internal resistance. Hydrogen generating bacteria (HGB) were only inoculated in TBE MFC. The peak power densities ($P_{peak}$) produced from the SCME systems fed with glucose and leachate were 18.8 and $28.7mW/m^2$ at external loads of 1000 ohms, respectively. And the $P_{peak}$ produced from TBE MFC were 40.1 and $18.3mW/m^2$ at sucrose concentration of 5 g/L and external loads of 470 ohms, with a mediator (2-hydroxy-1, 4-naphthoquinone) and without the mediator, respectively. The maximum power density ($P_{max}$) produced from mediator present TBE MFC was $115.3mW/m^2$ at 47 ohms of an external resistor.

• 한국지반환경공학회 논문집
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• 제14권10호
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• pp.5-9
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• 2013

점토성-사질토에 분포하는 양이온 금속들과 석유를 효율적으로 회수하기 위한 방법으로 동전기법 연구를 제안하였다. 제안된 동전기법은 투수계수가 낮은 매질 속에 존재하는 중금속에 포함되어 있는 양이온 금속 또는 석유등의 회수를 위해, 양극탱크(Anode chamber)에서 발생하는 잉여가스의 압력을 이용해서 점토성-사질토 샘플에 재주입하여 회수하는 기법이다. 제안된 동전기법의 성능을 확인하기 위해 제작된 샘플은 총 7일간에 점진적으로 압력을 증가시켜 최종 30psi($2.11kgf/cm^2$)의 압력으로 압축과정을 거쳐 완성되었다. 압축 전 샘플 내에 구리링을 삽입하여, 실험 종료 후 구리링의 변화된 모습을 관찰하였다. 본 연구에서 사용된 모듈은 가압식 모듈과 비가압식 모듈이고, 각각의 실험 테스트는 24시간 동안 2V/cm의 전압 경사 조건으로 연속적인 처리 공정으로 진행하였다. 그 결과, 가압식 모듈의 효율이 비가입식 모듈보다 우수한 것으로 나타났다.

• 신재생에너지
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• 제19권4호
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• pp.20-26
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• 2023

Emitted CO₂ is an attractive material for microbial electrochemical CO₂ reduction. Microbial electrochemical CO₂ reduction (i.e., microbial electrosynthesis, MES) using biocatalysts has advantages compared to conventional CO₂ reduction using electrocatalysts. However, MES has several challenges, including electrode performance, biocatalysts, and reactor optimization. In this study, an MES system was investigated for optimizing reactor types, counter electrode materials, and CO₂-converting microorganisms to achieve effective CO₂ upcycling. In autotrophic cultivation (supplementation of CO₂ and H₂), CO₂ consumption of Rhodobacter sphaeroides was observed to be four times higher than that with heterotrophic cultivation (supplementation of succinic acid). The bacterial growth in an MES reactor with a single-chambered shape was two times higher than that with a double chamber (H-type MES reactor). Moreover, a single-chambered MES reactor equipped with titanium mesh as the counter electrode (anode) showed markedly increased current density in the graphite felt as a working electrode (cathode) compared to that with a graphite felt counter electrode (anode). These results demonstrate that the optimized conditions of a single chamber and titanium mesh for the counter electrode have a positive effect on microbial electrochemical CO₂ reduction.

• 한국진공학회지
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• 제12권1호
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• pp.1-6
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• 2003

50 kW급 출력의 전자빔을 발생시킬 수 있는 축선 방식 전자총 (axial electron beam gun)과 전원장치를 제작하였다. 전자총은 전자빔 발생장치와 전자빔 궤적제어장치로 이루어졌다. 전자빔 발생장치는 필라멘트와 음극(cathode), 양극(anode)으로 구성되었고 전자빔의 최대전류는 2A, 가속전압은 평균 25kV이다. 전자빔 궤적제어장치는 전자빔의 크기를 조절하는 초점 (focusing) 코일과 전자빔의 방향을 조절하는 편향(deflection) 코일 및 주사 (scanning) 코일로 구성되었다. 전자총과 별개로 진공용기 내부에 Helmholtz 코일을 설치하여 시료의 표면에 입사되는 전자빔의 입사각도를 최적화시켰다. 각 부분의 동작 특성을 측정한 결과와 제작된 전자총으로 고융점 원소인 지르코늄 (zirconium, Zr)과 가돌리늄(gadolinium, Gd) 금속을 증발시킨 결과를 정리하였다.

• Journal of Microbiology and Biotechnology
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• 제25권7호
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• pp.1114-1118
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• 2015

Microbial fuel cells (MFCs) have gathered attention as a novel bioenergy technology to simultaneously treat wastewater with less sludge production than the conventional activated sludge system. In two different operations of the MFC and aerobic process, microbial growth was determined by the protein assay method and their biomass yields using real wastewater were compared. The biomass yield on the anode electrode of the MFC was 0.02 g-COD-cell/gCOD-substrate and the anolyte planktonic biomass was 0.14 g-COD-cell/g-COD-substrate. An MFC without anode electrode resulted in the biomass yield of 0.07 ± 0.03 g-COD-cell/g-CODsubstrate, suggesting that oxygen diffusion from the cathode possibly supported the microbial growth. In a comparative test, the biomass yield under aerobic environment was 0.46 ± 0.07 g-COD-cell/g-COD-substrate, which was about 3 times higher than the total biomass value in the MFC operation.

• 한국마이크로전자및패키징학회:학술대회논문집
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• 한국마이크로전자및패키징학회 2000년도 Proceedings of 5th International Joint Symposium on Microeletronics and Packaging
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• pp.110-110
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• 2000

Cantilever-shaped lateral field emitters were fabricated and their electrical characteristics were tested. As shown in Fig.1, poly-silicon cantilevers were fabricated by the surface micromachining and they were used to the vacuum magnetic field sensors. The tunneling devices were vacuum sealed with the tubeless packaging method, as shown in Fig.2 and Fig.3. The soda-lime glasses were used for better encapsulation, so the sputtered silicon and the glass layers on the soda-lime glasses were bonded together at 1x10$^{-6}$ Torr. The getter was activated after the vacuum sealing fur the stable emissions. The devices were tested outside of the vacuum chamber. Through vacuum packaging, the tunneling sensors can be utilized. Fig.4 shows that the sensor operates with the switching of the magnetic field. When the magnetic field was applied to the device, the anode currents were varied by the Lorentz force. The difference of anode currents can be varied with the strength of the applied magnetic field.

• Journal of Microbiology and Biotechnology
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• 제22권10호
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• pp.1395-1400
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• 2012

In this study, we investigated various cultural and operational factors to enhance electricity generation in a microbial fuel cell (MFC) using Geobacter sulfurreducens. The pure culture of G. sulfurreducens was cultivated using various substrates including acetate, malate, succinate, and butyrate, with fumarate as an electron acceptor. Cell growth was observed only in acetate-fed medium, when the cell concentrations increased 4-fold for 3 days. A high acetate concentration suppressed electricity generation. As the acetate concentration was increased from 5 to 20 mM, the power density dropped from 16 to $13mW/m^2$, whereas the coulombic efficiency (CE) declined by about half. The immobilization of G. sulfurreducens on the anode considerably reduced the enrichment period from 15 to 7 days. Using argon gas to create an anaerobic condition in the anode chamber led to increased pH, and electricity generation subsequently dropped. When the plain carbon paper cathode was replaced by Pt-coated carbon paper (0.5 mg $Pt/cm^2$), the CE increased greatly from 39% to 83%.