• Title/Summary/Keyword: Cathodic

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Optimization of Anodic/cathodic Utilization for a Residential Power Generation System (가정용 연료전지 시스템의 연료/공기 이용률 최적화)

  • Seok, Donghun;Kim, Minjin;Lee, Jinho
    • 한국신재생에너지학회:학술대회논문집
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    • 2011.05a
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    • pp.93.1-93.1
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    • 2011
  • To obtain higher power efficiency of Residential Power Generation System(RPG), it is needed to operate system on optimized stoichiometric ratio of fuel and air. In this paper, optimizing stoichiometric ratio of fuel/air is conducted through systematic experiments and modeling. Based on fundamental principles and experimental data, constraints are chosen. Using these stoichiometric ratios as decision variables, maximum power efficiency of system could be found. As a result of research, power efficiency of RPG system is improved.

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Electrophoretic Analysis of Haemolymph Proteins during Silkworm (Bombyx mori L.) Ontogenesis

  • Staykova, Teodora
    • International Journal of Industrial Entomology and Biomaterials
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    • v.14 no.1
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    • pp.37-44
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    • 2007
  • A study was made of the haemolymph protein spectrum of mulberry silkworm (Bomhyx mori L.) from the first larval instar to imago. Horizontal starch gel electrophoresis was used. Sixteen races and eight F1 interracial hybrids, raised in Bulgaria, were analyzed. During the ontogenesis, a total of 17 protein bands (15 cathodic and 2 anodic) were detected. Distinct dynamics in the haemolymph protein spectrum was observed, in result of different expression during the individual development associated with the processes of growth, histolysis and histogenesis. Based on the ontogenetic dynamics found, a correspondence was assumed between some proteins detected by us using the starch gel electrophoresis and major haemolymph proteins (SP1, SP2, MHPs and Vg) detected by other authors using the polyacrilamide gel electrophoresis. Intraracial and interracial polymorphism was observed in four protein zones. The effect of four polymorphic loci with codominant and null alleles was suggested.

Simulation for transport phenomena of DMFC (Direct Methanol Fuel Cell) (직접메탄올 연료전지내 전달현상에 대한 전산 모사)

  • Im, Hun-Suk;Kim, Yo-Jin;Hong, Won-Hi
    • 한국신재생에너지학회:학술대회논문집
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    • 2006.11a
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    • pp.490-493
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    • 2006
  • The results of simulation of direct methane fuel cell fed with liquid-state methanol feed are shown. This numerical process is based on mass and current conservation equations. The results showed that over low current density $(<200mA/cm^2)$ IV polarization curve was well-presented compared to experimental result. Methanol fed from anodic side moved into cathodic side through electrolyte membrane and the pressure near cathode electrode increased according to amount of methanol crossover and production of water. Besides change of overpotential on each el electrode were checked by x-axis.

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Preperation of catalyst having high activity on oxygen reduction (저온형 연료전지용 산소의 고활성 환원 촉매 제조)

  • 김영우;김형진;이주성
    • Proceedings of the Korea Society for Energy Engineering kosee Conference
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    • 1992.11a
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    • pp.39-40
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    • 1992
  • This paper dealt with the manufacturing of binary alloy catalyst and showed simple electrochemical method for determing catalytic activity of oxygen reduction in acid or alkaline electrolyte. The catalyst was prepared by impregnating transition metal salts on platinum or silver particles adsorbed before on carbon paper substrate. The electrochemical characteristics of the catalysts was investigated with carbon paper electrode or PTFE-boned porous electrode and then cathodic current densities and tafel slopes were compared. As a result, of all binary catalysts utilized in this work, Pt-Fe, Pt-Mo showed better oxygen reduction activity than pure platinum catalyst in acid electrolyte and Ag-Fe, Ag-Pt, and Ag-Ni-Bi-Ti catalyst did than pure silver catalyst in alkaline electrolyte. The current density of Pt-Fe electrode in acid electrolyte was one and half times higher than that of Pt electrode(~500mA/$\textrm{cm}^2$ at 0.7VvsNHE).

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A Study on XPS and XRR Characteristics of DLC films Deposited by FCVA Method (FCVA 방법으로 증착된 다이아몬드상 탄소 박막의 XPS 및 XRR 특성 연구)

  • 박창균;장석모;엄현석;서수형;박진석
    • The Transactions of the Korean Institute of Electrical Engineers C
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    • v.52 no.3
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    • pp.109-115
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    • 2003
  • Diamond-like carbon (DLC) films are deposited at room temperature using a filtered cathodic vacuum arc (FCVA) technique. The influence of negative bias voltage (applied to the substrate from 0 to -250V) on the $sp^3$ hybridized carbon fraction is examined by Raman spectroscopy and x-ray photoelectron spectroscopy (XPS) for C 1s core peak. For the first time, depth profile of C 1s, Si 2p, and O 1s XPS peaks for the deposited DLC film are obtained. DLC film is modeled as a multilayered structure. composing of surface, bulk, and interface. In addition, the x-ray reflectivity (XRR) is proposed as a method for estimating the density, surface roughness, and thickness of each layer constituting the DLC film. The estimated thickness of DLC film is in good agreement with the result obtained from the transmission electron microscope (TEM) measurement.

The Development of The Remote Real-Time Corrosion Monitoring and Control System Using by TRS for Maritime Metallic Structures (TRS를 이용한 해양구조물의 원격 실시간 부식감시 및 방식 제어시스템 개발)

  • Bae, Jeong-Hyo;Ha, Tae-Hyun;Lee, Hyun-Goo;Kim, Dae-Kyeong;Choi, Sang-Bong;Jeong, Seong-Hwan
    • Proceedings of the KIEE Conference
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    • 2000.11d
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    • pp.657-659
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    • 2000
  • The importance of total management for maritime structures (Ports, Piers, docks. marine bridges, marine roads, submarine pipelines, etc.) is more and more increasing in these days. Especially, in spite of the marine structures are exposed at the various corrosion circumstances, there are not only a standard of Cathodic Protection System but also knowledge of importance for necessity of corrosion monitoring. Therefore, this paper presents the results of development for the Remote Real-Time Corrosion Monitoring and Control System Using by TRS on Maritime Metallic Structures which can be prevents a big accident by corrosion.

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The design of cathodic protection for Sihwa tidal power plant in the sea (시화조력 수차발전설비 해수내 전기방식 설계)

  • Kim, Jong-Deug;Min, Hoon-Jin;Kang, Dong-Hyung;Kang, Il-Kweon
    • Proceedings of the KIEE Conference
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    • 2006.07a
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    • pp.110-111
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    • 2006
  • 본 논문은 시화 방조제상에 공사중인 국내최초, 세계 최대설비용량인 254,000kW의 벌브형 수차발전설비가 수중에 설치되도록 설계되어 있어 해수에 의한 설비부식으로부터 설비를 보호하기 위한 전기방식설비 설계의 적정성과 시스템 구성에 대해서 고찰하기 위한 것이다. 시화조력발전소에 적용될 전기방식설계의 적정성을 사전 예측하기 위하여 전문 프로그램을 활용하여 시뮬레이션을 시행하였으며 방식전위 실시간 감시 및 제어기능은 물론 수차발전설비 운전상태와 연동하여 방식전위를 자동제어 할 수 있는 최적제어시스템 설계내용을 제시하였다.

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On the electropolymerization of acrylonitrile as effected by cyclic voltammetry and chronoamperometry method

  • Seo, H.J.;Cho, M.S.;Nam, J.D.;Lee, Y.
    • Proceedings of the Polymer Society of Korea Conference
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    • 2006.10a
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    • pp.335-335
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    • 2006
  • Polyacrylonitrile (PAN) was deposited as an adherent film on Cu-substrate by the cathodic electropolymerization. This work is an attempt to compare the molecular weight and the fractured surface of PAN prepared by CV and chronoamperometry. The molecular weight and increase weight of PAN measured the according to AN-concentration, scan rate, and cycle number (or time) using CV and chronoamperometry. The morphology of PAN was characterized by SEM image. Mechanism and optimal conditions for electropolymerization of acrylonitrile on Cu-substrate were investigated and discussed.

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A Study on Corrosion Failure of a Weathering Steel Weldment with Various Applied Potentials in Acid-chloride Solution (산-염소이온 분위기의 인자전위에 따른 내후성강 용접부의 부식파괴에 관한 연구)

  • 최윤석;김정구;김종집;이병훈
    • Journal of Welding and Joining
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    • v.18 no.3
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    • pp.97-105
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    • 2000
  • The stress corrosion cracking(SCC) and hydrogen embrittlement cracking(HEC) characteristics of a weathering steel weldment were investigated in aerated acid-chloride solution. The electrochemical properties of weldment were investigated by polarization test and galvanic corrosion test. Weathering steel did not show passive behavior in the acid-chloride solution. Galvanic corrosion between the weld metal and the base metal was not observed because the base metal was anodic to the weld metal. The slow-strain-rate tests(SSRT0 were conducted at a constant strain rate o 7.87×{TEX}$10^{-7}${/TEX}/s at corrosion potential, and at potentiostatically controlled anodic and cathodic potentials. The weldment of weathering steel was susceptible to both anodic dissolution SCC and hydrogen evolution HEC.

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Wear Characterisitics of TiN-coated Boron Cast Iron by Arc Evaporation Process (CAE 증착기술에 의해 TiN이 증착된 보론주철의 마모거동)

  • Song, Kun;Yoon, Eui-Sung;Ahn, Hyo-Sok
    • Tribology and Lubricants
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    • v.8 no.1
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    • pp.63-69
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    • 1992
  • In order to gain better understanding of wear behaviors of TiN-coated boron cast iron, tests and analyses were conducted with block-on disc type tribometer. TiN layer of thickness $2 \mu m$ and $4 \mu m$, coated by cathodic arc evaporation process, were experimentally investigated with the variation of applied load and sliding speed under dry sliding condition. Wear characteristics were expressed in terms of the three-dimentional wear map as well as the wear rate vs sliding speed and load. Comparisons of wear and friction characteristics between coated cast irons and uncoated cast irns were also made. Wear mechanism of TiN layer was explained in view of surface interaction between the mating surfaces. The thicker coating exhibited higher hardness and adhesion strength. the significance of stresses at the surface and in the subsurface was briefly discussed in relation to the wear behavior.