• Title/Summary/Keyword: Renewable material

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Preparation and Characterization of a Surface Renewable Solid State Hg/HgO Reference Electrode Utilizing Gold Amalgam

  • Kim, Won;Park, Jong-Man
    • Bulletin of the Korean Chemical Society
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    • v.28 no.3
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    • pp.439-442
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    • 2007
  • A solid state Hg(Au)/HgO reference electrode was prepared utilizing gold amalgam solid particles. Solid fine powder of the gold amalgam was prepared by chemical reduction of Au(III) with NaBH4 followed by reduction of Hg(II) in the presence of gold fine particles. The solid content in the suspension of the gold amalgam particles and fine mercury oxide particles in DMF containing PVC was precipitated by the addition of a large amount of water to give solid Hg(Au)/HgO/PVC mixture. After drying, the mixture was pressure-molded to a physically stable Hg(Au)/HgO composite reference electrode material. The electrochemical characteristics of the electrode as a reference electrode were very similar to an ordinary Hg/HgO reference electrode. The electrode material can be molded and fabricated in any desired shape and size. The surface can be renewed by a simple polishing process whenever contaminated or deactivated. The applicability of the electrode in the electrochemical detection of carbohydrates after anion exchange separation was evaluated.

Analytic study and prototype development of a novel micro hydropower generator, Katamax (신개념 소수력 발전설비 Katamax에 대한 이론적 고찰 및 Prototype 제작 결과)

  • Kim, W.;Max, Blomeier;Eom, B.J.;Kim, D.H.;You, H.D.;Koo, H.C.
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2001.11b
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    • pp.69-72
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    • 2001
  • A novel water-turbine, Katamax, for micro hydropower generator is proposed, which has reasonable efficiency even in two meters of water head. The basic concept of Katamax is similar to that of waterwheel except that Katamax has two axis on which the blades rotate, where general waterwheel has only one. Brief structure and principles of Katamax are explained and analysis for efficiency of each module are provided. The result of the prototype product of Katamax is briefly explained.

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Hydrogen Storage Behaviors of Porous Carbons

  • Kim, Byung-Joo;An, Kay-Hyeok;Park, Soo-Jin
    • 한국신재생에너지학회:학술대회논문집
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    • 2009.11a
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    • pp.230-230
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    • 2009
  • In this work, Porous Carbons (PCs) were prepared by using a chemical acid treatment, and the hydrogen storage behaviors of PCs doped by Pt nanoparticles were investigated. The hydrogen storage capacities of the Pt-doped carbons with a platinum content of 0.2 - 1.5 wt.% were evaluated by a volumetric adsorption method at 298K and 10 MPa. The microstructures of samples were examined by XRD and SEM. It was found that the hydrogen storage capacitiesof the PCs dramatically increased, but the amount of hydrogen stored from the samples began to decrease after 0.6 wt.% of Pt content due to the pore blocking. These results indicate that a suitable amount of supported catalysts and layer intervals of carbons had a very important impact on hydrogen storage behaviors.

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Synthesis and Characterization of LSCF/CGO Composite Used as SOFC Cathode Materials (SOFC 용 LSCF/CGO 공기극의 제조 및 특성연구)

  • Park, Jae-Layng;Lim, Tak-Hyoung;Lee, Seung-Bok;Park, Seok-Joo;Shin, Dong-Ryul;Song, Rak-Hyun
    • 한국신재생에너지학회:학술대회논문집
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    • 2009.11a
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    • pp.184-186
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    • 2009
  • Composites of LSCF($La_{0.6}Sr_{0.4}Co_{0.2}Fe_{0.8}O_{3-\delta}$ and CGO(gadolinium doped ceria) is an efficient candidate cathode material with CGO electrolytes. In this study, LSCF with exact perovskite structure was synthesized by using solid state reaction(SSR) method. The optimized temperature to synthesize $La_{0.6}Sr_{0.4}Co_{0.2}Fe_{0.8}O_{3-\delta}$ with rhombohedral structure. was $1100^{\circ}C$. The polarization resistance of the LSCF/CGO(50:50 wt.%) was smaller than those of other composite cathodes. The analysis of the EIS data of LSCF/CGO suggests that the diffusion and adsorption-desorption of oxygen can be the key process in the cathodic reaction of SOFC using LSCF/CGO as cathode material.

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The Study on Activity Star Problem and Optimum Construction Method Through the Defect Case of Zero Energy House in the Existing Building (기축건물의 제로에너지 하우스 하자 사례를 통한 공종별 문제점 및 최적구축 방안에 관한 연구)

  • Kim, Sun-Geun;Kwon, Soon-Wook
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.28 no.4
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    • pp.262-270
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    • 2015
  • In this paper existing buildings, not a new buildings and house for living people not just a displaying and a viewing, created by the imagine effect or virtual simulation was applied various Active and Passive elements. After constructing zero-energy houses, through default case happened during operation period it is described problems and solutions about field part, work classification, installation by Location part, and Installation equipment part. Since then, to take advantage of this thesis, it's the purpose of this paper using as the baseline data for building a zero-energy house in another similar case.

In-situ Raman Spectroscopy of Amorphous Hydrous $RuO_2$ Thin Films

  • Hyeonsik Cheong;Jung, Bo-Young;Lee, Se-Hee
    • Journal of the Korean Vacuum Society
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    • v.12 no.S1
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    • pp.49-51
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    • 2003
  • Amorphous hydrous ruthenium oxide thin films have attracted much interest owing to the possibility of using this material in electrochemical supercapacitors. Recently, it was found that this material is also electrochromic: during the charging/discharging cycle, the optical transmittance of the thin film is modulated. The physical and chemical origin of this phenomenon is not fully understood yet. In this work, we performed in-situ Raman spectroscopy measurements on amorphous hydrous ruthenium oxide thin films during the charging/discharging cycles. Unambiguous changes in the Raman spectrum were observed as protons were injected or extracted from the thin film. When the samples were annealed to reduce the water content, there is a consistent trend in the Raman spectrum. The origins of the Raman features and their relation to the electrochromic and/or supercapacitor characteristics is discussed.

Analytic study and prototype development of a novel micro hydropower generator, Katamax (신개념 소수력 발전설비 Katamax에 대한 이론적 고찰 및 Prototype 제작 결과)

  • Kim, W.;Blomeier, M. H.;Eom, B. J.;Kim, D. H.;You, H. D.;Koo, H. C.
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2001.11a
    • /
    • pp.69-72
    • /
    • 2001
  • A novel water-turbine, Katamax, for micro hydropower generator is proposed, which has reasonable efficiency even in two meters of water head. The basic concept of Katamax is similar to that of waterwheel except that Katamax has two axis on which the blades rotate, where general waterwheel has only one. Brief structure and principles of Katamax are explained and analysis for efficiency of each module are provided. The result of the prototype product of Katamax is briefly explained.

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Study on the Design of Power MOSFET with ESD Protection Circuits (Zener ESD 보호회로 내장 전력 MOSFET 최적 설계)

  • Nahm, Eui-Seok;Kang, Ey Goo
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.28 no.9
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    • pp.555-560
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    • 2015
  • This paper was proposed 900 V Power MOSFET with ESD protection circuits using zener diodes. And we were carried out and analyzed its electrical characteristics. As a result of designing 900 V power MOSFET, we obtained 1,000 V breakdown voltage, 3.49 V threshold voltage and $0.249{\Omega}{\cdot}cm^2$. And we designed ESD circuits using 2 series zener diode and 4 series zener diodes. After analyzing electrical characteristics, we obtained 26 V forward voltage drop and 47 V breakdown voltage. Therefore, This devices can enoughly use power module, SMPS and Automotive.

Analysis of Electrical Properties for Optimal Operating Conditions of Mono-crystalline Si Solar Cell (단결정 실리콘 태양전지 최적 운전조건을 위한 전기적 특성 분석)

  • Kim, Ji-Woong;Choi, Yong-Sung;Lee, Kyung-Sup;Cho, Soo-Young;Hwang, Jong-Sun
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.24 no.8
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    • pp.654-658
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    • 2011
  • This paper was investigated the electrical properties for optimal operating conditions of monocrystalline silicon solar cell. The output of electricity for monocrystalline solar cell was investigated according to the distances between solar cell and halogen lamp and to the resistances by the variable resistor.

Modelling of Grain Boundary in Polysilicon Film for Photodetector Through Current-Voltage Analysis (광검출기용 다결정 실리콘 박막의 전도특성 분석을 통한 결정립계의 모형화)

  • Lee, Jae-Sung
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.33 no.4
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    • pp.255-262
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    • 2020
  • Grain boundaries play a major role in determining device performance, particularly of polysilicon-based photodetectors. Through the post-annealing of as-deposited polysilicon and then, the analysis of electric behavior for a metal-polysilicon-metal (MSM) photodetector, we were able to identify the influence of grain boundaries. A modified model of polysilicon grain boundaries in the MSM structure is presented, which uses a crystalline-interfacial layer-SiOx layer- interfacial layer-crystalline system that is similar to the Si-SiO2 system in MOS device. Hydrogen passivation was achieved through a hydrogen ion implantation process and was used to passivate the defects at both interfacial layers. The thin SiOx layer at the grain boundary can enhance the photosensitivity of an MSM photodetector by decreasing the dark current and increasing the light absorption.