• 제목/요약/키워드: redox properties.

검색결과 301건 처리시간 0.031초

바나듐 레독스 흐름전지용 접촉저항 감소 일체형 전극-분리판 조립체 개발 (Development of an Integrated Electrode-bipolar Plate Assembly with Reduced Contact Resistance for Vanadium Redox Flow Battery)

  • ;임준우
    • Composites Research
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    • 제37권3호
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    • pp.190-196
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    • 2024
  • 분리판은 바나듐 레독스 흐름전지(VRFB) 스택 내 셀의 전기적 통로 및 구조적 지지 역할 수행하는 매우 중요한 부품 중 하나이다. 흑연 소재는 전기 전도성이 뛰어나 분리판에 주로 사용되지만, 셀 스택에서 전극과 분리판 사이에 높은 계면 접촉 저항(ICR)이 발생하여 VRFB의 성능에 심각한 제한이 존재한다. 본 연구에서는 ICR의 한계를 해결할 수 있는 일체형 전극-분리판 조립체를 개발하는 것을 목표로 하였다. 일체형 조립체는 핫 프레스 방법을 활용하여 열가소성 및 열경화성 폴리머와 단일 탄소 펠트를 사용하여 제작하였다. 실험 결과, 일체형 조립체가 연속적인 전기 경로로 인해 감소된 전체 저항을 나타냄을 확인하였다. 또한, 충/방전 셀 테스트 결과에서 일체형 조립체는 향상된 셀 성능을 보여주었다. 따라서 개발된 일체형 전극-분리판 조립체는 기존의 분리판 및 전극 조립체를 대체할 수 있을 것으로 판단된다.

폴리피리딘계 LB 단분자막의 표면측정과 전기화학적 감광특성 (Surface Characteristics and Photoelectrochemical Properties of the Polyphridine LB films)

  • 최인희;나재진;임기조;박수길;이주성
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 1995년도 춘계학술대회 논문집
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    • pp.132-135
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    • 1995
  • This paper describes the electrochemical and photochemical behavior of amphiphilic Os bipyridine compelx adsorbed on SnO$_2$electrodes by the Langmuir-Blodgett(LB) film as monolayer state. Theoretical equation of cyclicvoltammetry for redox species were discussed. And the cyclic voltammogram were simulated taking account theinteraction parameters. From these obtained values, we could fit almost all measured voltammograms with these parameters.

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Effects of t-Butyl Hydrogen Peroxide on the Maxi-K Channels of Rat Brain

  • Shin, Jung-Hoon;Suh, Chang-Kook
    • 한국생물물리학회:학술대회논문집
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    • 한국생물물리학회 1998년도 학술발표회
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    • pp.33-33
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    • 1998
  • Oxidation and reduction of amino acid residues in proteins affect their functional properties. Especially, redox modulation of ion channel activities has been reported in number of ion channel proteins. In this study, we investigated the effects of tertiary-butyl hydrogen peroxide (tBHP) on the large-conductance Ca$\^$2+/ -activated K$\^$+/(Maxi-K) channel of rat brain using lipid bilayer reconstitution technique.(omitted)

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바나듐 무기막의 산소투과 특성 (Oxygen Permeation Properties of Vanadium coated inorganic membrane)

  • 문상진;정지훈;홍석인
    • 한국막학회:학술대회논문집
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    • 한국막학회 1995년도 춘계 총회 및 학술발표회
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    • pp.54-55
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    • 1995
  • 무기막은 고분자막에 비해서 고온에서의 사용이 가능하고 구조적 안정성 등이 우수한 특징이 있다. 이러한 무기막에 촉매를 담지하거나 코팅하여 분리막의 역할과 촉매로서의 역할을 동시에 수행하는 막반응기로의 응용이 가능하다. 본 연구에서는 Redox mechanism에 의한 부분산화반응을 일으키는 촉매인 오산화바나듐을 sol-gel법으로 코팅한 무기막을 제조하여, 막내부에 오산화바나듐의 격자산소를 이용하는 부분산화 반응물이 존재할 때 선택적으로 증가하는 산소의 투과특성을 조사하였다.

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Polyaniline 필름의 산화환원 특성 및 리튬 2차 전지 응용 (Redox Properties of Polyaniline Films and Its Application to Lithium Secondary Batteries)

  • 김현철;박영철;구할본
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 1997년도 추계학술대회 논문집
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    • pp.144-148
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    • 1997
  • We synthesized polyaniline films electrochemically under constant current conditions, which exhibited electric conductivity as high as 100 S/cm. By charge and discharge cycling of polyaniline films, we obtained specific discharge capacity as high as 195 mAH/g using HSO$_4$- doped polyaniline. For the polyaniline synthesized using H$_2$SO$_4$ and HClO$_4$ composite electrolyte. we also obtained specific discharge capacity as high as 134 mAHg which rivals inorganic electro- active materials.

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Synthesis and Characterization of Copper(Ⅱ) Complex Containing 2,2'-dipyridylbenzamide

  • 이동환;김병순;오영희;라명수;장원길
    • Bulletin of the Korean Chemical Society
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    • 제17권9호
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    • pp.836-839
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    • 1996
  • A new copper complex containing 2,2'-dipyridylbenzamide(dpba), Cu(dpba)(NO3)2(CH3CN), has been synthesized and characterized. The crystal structure has been determined. Crystal data: space group P212121, Z=8, a=13.911(3) Å, b=16.813(3) Å, c=18.932(3) Å, V=4427.9(1) Å3 and R=0.0674 for 1716 reflections. The copper environment is square pyramidal containing acetonitrile in axial site. Spectroscopic properties has been characterized in solution state. The redox property of the Cu(dpba)(NO3)2 complex is different from that of corresponding copper-dpa complex.

The Mechanism of DNA Strand Scissions Induced by Brazilin : Involvement of Reactive Oxygen Species and Cu(II)/Cu(I) Redox Cycling

  • Lee, Sun-Young;Kim, Tae-Ho;Kim, Seog K.;Mar, Woong-Chon;Seo, Eun-Kyoung;Lee, Chong-Soon
    • 대한약학회:학술대회논문집
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    • 대한약학회 2003년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.1
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    • pp.268.1-268.1
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    • 2003
  • Brazilin is the phenolic compound isolated from the Caesalpinia sappan. This compound has shown a wide range of physiological properties, such as hypoglycemic, anticonvulsant, vasorelaxing, and immunomodulating effects. In this study, we have found that brazilin induced DNA strand scissions in the presence of Cu(II) and this DNA cleavages were mediated by reactive oxygen species. (omitted)

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Mass Transport Properties and Influence of Natural Convection for Voltammetry at the Agarose Hydrogel Interface

  • Kim, Byung-Kwon;Park, Kyungsoon
    • Journal of Electrochemical Science and Technology
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    • 제13권3호
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    • pp.347-353
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    • 2022
  • Agarose hydrogel, a solid electrolyte, was investigated voltammetrically in terms of transport properties and natural convection effects using a ferrocenyl compound as a redox probe. To confirm the diffusion properties of solute on the agarose interface, the diffusion coefficients (D) of ferrocenemethanol in agarose hydrogel were determined by cyclic voltammetry (CV) according to the concentration of agarose hydrogel. While the value of D on the agarose interface is smaller than that in the bulk solution, the square root of the scan rate-dependent peak current reveals that the mass transport behavior of the solute on the agarose surface shows negligible convection or migration effects. In order to confirm the reduced natural convection on the gel interface, scan rate-dependent CV was performed in the solution phase and on the agarose surface, respectively. Slow scan voltammetry at the gel interface can determine a conventional and reproducible diffusion-controlled current down to a scan rate of 0.3 mV/s without any complicated equipment.

적변삼의 생물.화학적 특성과 그 발생원인에 관하여 (Studies on the Biological and Chemical Properties of Musty Ginseng Root and its Causal Mechanism)

  • 정영륜;오승환
    • Journal of Ginseng Research
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    • 제9권1호
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    • pp.24-35
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    • 1985
  • Rusty root of ginseng has been known as one of the limiting factors in ginseng production in Korea. An attempt was, therefore, made to elucidate biological and chemical natures of the rusty root, and the redox Potential of the ginseng cultivated soils were measured and compared with diseased and non-diseased soils. Reddish discoloration was most frequently observed on the epidermis of ginseng root and the pigments were accumulated in all epidermal cells of the diseased lesions. The lower the redox potential of the ginseng cultivated soil was, the more severe the rusty root was observed. Fe content in the diseased epidermis was 3 times higher than that of healthy one. Organic acids such as oxalic, malonic, succinic, and citric acids were also higher in the mss root than in the healthy one. Thin layer chromatogram of phenolic acid fractions obtained from the epidermal cells of the rusty root of ginseng exhibited 3 to 4 unidentified substances not found in the healthy root. Also lignification of the epidermal cells and the activity of phenylalanine ammonia lyase were greater in the rusty root than the healthy root. Colony formation and conidia production of F. solani, And mycelial growth and sclerotium formation of Sclerotinia sp. isolated from ginseng root were suppressed in a nutritionally minimal medium supplemented with water extract of rusty ginseng root epidermis. It is, therefore, suggested that rusty root of ginseng is caused by unfavorable rhizosphere environmental stress or stresses resulting abnormal metabolism in the root as a selfdefence mechanism of non-specific resistance responses.

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