• Title/Summary/Keyword: Cathodes

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A Study of Slow Wave Instability on High Power Generator (대 출력 발생장치의 지파불안정성 연구)

  • Kim, Won-Sop;Kim, Jong-Man
    • Proceedings of the KIEE Conference
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    • 2011.07a
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    • pp.2109-2109
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    • 2011
  • High power microwave sources operating in relativistic regions, high current reletivistic electron beams are obtained by using cold cathodes with the help of explosive emission. For these relativistic devices, the pulsed power and magnetic field systems are very large and heavy. The phase velocity of electromagnetic mode should be showed down close to the beam velocity, ensuring enough beam coupling with electromagnetic modes. By using the annular electron beam, a weakly relativistic oversized bwo consisting of rectangularly corrugated cylindrical waveguide is demonstrated.

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A Study on Characteristics of Organic Light-Emitting Device with Various Cathodes (음극전극의 종류에 따른 유기발광소자의 특성에 관한 연구)

  • 노병규;김중연;오환술
    • Proceedings of the IEEK Conference
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    • 2000.11b
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    • pp.37-40
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    • 2000
  • This paper has been studied on characteristics of organic light-emitting device with various cathode materials. These catode materials were Al:Li(5%), Al, Cu, CsF/Al. And in these devices, HTL(hole transfer layer) was TPD and EML(emitting layer) was Alq$\sub$3/. We studied the I-V characteristics for each device. And then, the turn-on voltage of device for Al-Li(5%), Al, Cu, CsF/Al cathode were 7, 9, 13, 3V respectively. So, the CsF/Al cathode is superior to other cathode materials for I-V characteristics.

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Reduction Method of Radio Interference in HVDC Converter System (HVDC 컨버터 시스템에서 라디오 장해에 대한 대책)

  • Kim, Chan-Ki;Choi, Soon-Ho
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.61 no.6
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    • pp.833-837
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    • 2012
  • In HVDC System, the rapid voltage breakdown between anodes and cathodes during valve firing causes radio interference in HVDC converter station. These voltage breakdown causes steep current pulse and inject current in system. As a result, harmonic frequencies are generated from valve, switchyard. In this paper, theoretical background of radio interference in HVDC converter is discussed and its reduction method for radio interference is proposed.

Highly Efficient Top-Emitting Electrophosphorescent Organic Light-Emitting Devices

  • Lu, Min-Hao M.;Weaver, Michael S.;Zhou, Theodore X.;Rothman, Mark;Kwong, Raymond C.;Hack, Mike;Brown, Julie J.
    • 한국정보디스플레이학회:학술대회논문집
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    • 2002.08a
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    • pp.90-93
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    • 2002
  • We present both a theoretical analysis and experimental data to show that electrophosphorescent top-emitting organic light emitting-devices (TOLEDs) with a reflective anode and a transparent cathode can be more efficient than the equivalent state-of-the-art bottom-emitting electrophosphorescent OLEDs (PHOLEDs$^{TM}$). The lifetime of devices with transparent cathodes are shown to approach that of the corresponding bottom-emitting devices.

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Simulation Study for the Vircator with three cathodes ring (고출력 마이크로파 발생장치인 링형태의 세 개의 캐소드를 가전 버카터의 시뮤레이션 연구)

  • Lee, Bong-Kyun
    • Proceedings of the KIEE Conference
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    • 1998.07e
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    • pp.1850-1851
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    • 1998
  • Using the "MAGIC" code, computer simulation is performed to design a cathode structure which provides a radial distribution of electron beam density matching the field distribution of the $TM_{05}$ mode. Thus, very narrow band $TM_{05}$ mode microwave radiation can be generated in an open end waveguide. The simulation results show that the vircator can indeed be operated at the selected frequency 10.2GHz with a very narrow bandwidth(${\Delta}{\omega}/{\omega}$ < 1%).

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Deposition and high temperature oxidation characterization of CrAlSiN thin films

  • Kim, Sun-Kyu;Lee, Dong-Bok
    • Proceedings of the Korean Institute of Surface Engineering Conference
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    • 2007.11a
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    • pp.7-9
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    • 2007
  • Thin films of CrAlSiN were deposited on SKD11 tool steel substrate using Cr and AlSi cathodes by a cathodic arc plasma deposition system. The influence of process parameters on the deposited film properties were investigated. The oxidation characteristics of the films were studied at temperatures ranging from 800 and 1000+C up to 50 h in air. The films showed superhardness and good oxidation resistance..

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The Evaluation of Electrolytic Nitrate Removal Efficiency of TiO2 Nanotube Plate (TiO2 nanotube plate의 질산성질소 전기분해 효율 평가)

  • Kim, Da Eun;Lee, Yongho;Han, Heeju;Choi, Hyo yeon;Pak, Daewon
    • Journal of the Korean Applied Science and Technology
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    • v.35 no.3
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    • pp.612-621
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    • 2018
  • In this study, $TiO_2$ nanotube plate and metal electrodes(Copper, Nickel, Stainless Steel, Aluminum, Tin, Titanium) were compared on cathodic reduction of nitrate ($NO_3{^-}-N$) during electrolysis. The electrochemical characteristics were compared based on electrochemical impedance spectroscopy (EIS). The surface morphology was obtained using scanning electron microscopy (SEM) method. Brunauer-Emmett-Teller (BET) method was implemented for the specific surface area analysis of the cathodes. To study kinetics, 90 minute batch electrolysis of nitrate solution was performed for each cathodes. In conclusion, under the condition of relatively low ($0.04 A\;cm^{-2}$) current density, $TiO_2$ nanotube plate showed no surface corrosion during the electrolysis, and the reaction rate was measured the highest in the kinetic analysis.

Phylogenetic Diversity of Dominant Bacterial and Archaeal Communities in Plant-Microbial Fuel Cells Using Rice Plants

  • Ahn, Jae-Hyung;Jeong, Woo-Suk;Choi, Min-Young;Kim, Byung-Yong;Song, Jaekyeong;Weon, Hang-Yeon
    • Journal of Microbiology and Biotechnology
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    • v.24 no.12
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    • pp.1707-1718
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    • 2014
  • In this study, the phylogenetic diversities of bacterial and archaeal communities in a plant-microbial fuel cell (P-MFC) were investigated together with the environmental parameters, affecting its performance by using rice as a model plant. The beneficial effect of the plant appeared only during a certain period of the rice-growing season, at which point the maximum power density was approximately 3-fold higher with rice plants. The temperature, electrical conductivity (EC), and pH in the cathodic and anodic compartments changed considerably during the rice-growing season, and a higher temperature, reduced difference in pH between the cathodic and anodic compartments, and higher EC were advantageous to the performance of the P-MFC. A 16S rRNA pyrosequencing analysis showed that the 16S rRNAs of Deltaproteobacteria and those of Gammaproteobacteria were enriched on the anodes and the cathodes, respectively, when the electrical circuit was connected. At the species level, the operational taxonomic units (OTUs) related to Rhizobiales, Geobacter, Myxococcus, Deferrisoma, and Desulfobulbus were enriched on the anodes, while an OTU related to Acidiferrobacter thiooxydans occupied the highest proportion on the cathodes and occurred only when the circuit was connected. Furthermore, the connection of the electrical circuit decreased the abundance of 16S rRNAs of acetotrophic methanogens and increased that of hydrogenotrophic methanogens. The control of these physicochemical and microbiological factors is expected to be able to improve the performance of P-MFCs.