• Title/Summary/Keyword: Ni-S

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Preparation of Co-Ni Electrode by Precipitation Method and it's Application for Molten Carbonate Fuel Cell or Optimization of Co-Ni Electrode's Fabrication and it's Application for Molten Carbonate Fuel Cell (침전법을 활용한 Co-Ni 전극의 제조와 용융탄산염 연료전지의 그 적용)

  • Kim, S.Y.;Devianto, Hary;Ryu, B.H.;Hahm, H.C.;Han, J.;Yoon, S.P.;Nam, S.W.;Lim, T.H.;Lee, H.I.
    • New & Renewable Energy
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    • v.4 no.1
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    • pp.11-18
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    • 2008
  • In-situ lithiated NiO has been manufactured as a conventional cathode material of molten carbonate fuel cell (MCFC), however this material has a weakness for commercialization of MCFC because NiO is spontaneously dissolved into the electrolyte under MCFC operating conditions, resulting in short circuit between cathode and anode. In this research, therefore, $Co(OH)_2$-coated Ni powder was prepared by precipitation method with controlling pH at low temperature and atmospheric pressure. Modified cathode was fabricated by a conventional tape casting method and sintered at 700$^{\circ}C$ in a $H_2/N_2$ atmosphere, Based on characterization result, Pore size distribution and porosity was suitable for the cathode of MCFC. According to the result of dissolution, Ni solubility of modified cathode was 33% lower than that of conventional cathode. In addition, modified electrode showed a good performance from the single cell operation.

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A study on the effect of alumina coating on NiO dissolution in molten carbonate fuel cell (용융탄산염형 연료전지의 NiO 공기극의 용해거동에 미치는 알루미나 코팅효과에 대한 연구)

  • Ryu B. H.;Yoon S. P.;Han J;Nam S. W.;lim T.-H.;Hong S.-A.
    • New & Renewable Energy
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    • v.1 no.1 s.1
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    • pp.64-71
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    • 2005
  • The stability of alumina-coated NiO cathodes was studied in $Li_{0.62}/K_{0.38}$ molten carbonate electrolyte. Alumina was effectively coated on the porous Ni plate using galvanostatic pulse plating method. The deposition mechanism of alumina was governed by the concentration of hydroixde ions near the working electrode, which was controlled by the temperature of bath solution. Alumina-coated NiO cathodes were formed to $A1_2O_3-NiO$ solid solution by the oxidation process and their Ni solubilities were were than that of NiO up to the immersion time of 100h. However, their Ni solubilities increased and were similar to that of the bare NiO cathode after 100h. It was because aluminum into the solid solution was segregated to $\alpha-LiAlO_2$ on the NiO and its Product did not Play a role of the Physical barrier against NiO dissolution.

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NiO Buffer layer 형성을 통한 유기태양전지 안정성 향상 연구

  • An, Won-Min;Jeong, Seong-Hun;Kim, Do-Geun
    • Proceedings of the Korean Institute of Surface Engineering Conference
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    • 2015.11a
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    • pp.306-307
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    • 2015
  • 유기태양전지의 대표적 Hole Transporting Layer(HTL)로는 전도성 고분자인 PEDOT:PSS이다. PEDOT:PSS는 약산성의 물질로 전극을 부식시켜 디바이스의 효율을 감소시키기 때문에 PEDOT:PSS를 대체하기 위한 Buffer층에 대한 연구가 활발히 진행되어지고 있다. PEDOT:PSS를 대체할 수 있는 Nickel Oxide(NiO) Buffer 층은 wide band-gab으로 Hole Transporting Layer와 Electron Blocking Layer 역할을 동시에 하여 디바이스의 효율을 향상시킬 수 있으며, 디바이스의 수명을 향상시킬 수 있다는 장점이 있다. NiO는 용액공정과 Sputter 증착 방법으로 형성할 수 있는데, 용액공정은 고온공정이 요구되어지고 Sputter 증착방법은 산화되기 쉬운 전극위에서는 전극의 손상을 발생한다. 본 연구에서는 이러한 단점을 해결하기 위해서 Ni을 Magnetron Sputter로 증착한 후 Ion Beam 처리를 통해 산화시켜 NiO 층을 형성하는 방법을 연구하였다. 본 연구에서 제안한 NiO형성 방법으로 유기태양전지를 제작하여 PEDOT:PSS를 Buffer층으로 사용한 태양전지와 Voc가 0.72 V로 유사하게 나와 NiO가 Buffer층으로 잘 형성된 것을 확인하였다.

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Thermodynamic Phase Equilibrium of Aqueous Fe-Ni-Cu-S-H2O Solution for Fe-Ni-Cu Alloy Plating (Fe-Ni-Cu 합금도금을 위한 Fe-Ni-Cu-S-H2O 용액의 열역학적 상의 안정도)

  • Baek, Yeol;Han, Sang-Seon;Choe, Yong
    • Proceedings of the Korean Institute of Surface Engineering Conference
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    • 2017.05a
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    • pp.123.2-123.2
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    • 2017
  • Fe-Ni-Cu 합금 전주를 위하여 황화물 용액에의 상의 열역학적 안정도를 작성하고 전주 조건을 선정하였다. $Fe-Ni-Cu-S-H_2O$ 용액의 열역학적 상의 안정도를 전산모사하기 위한 프로그램은 C#으로 작성하였다. JANAF 자료를 근거한 적정 전주 조건은 $130mA/cm^2$, $50{\sim}55^{\circ}C$, pH 2.4 이었다. XRF을 이용한 Fe-Ni-Cu의 합금 도막의 평균 조성은 Fe-42Ni-1Cu [wt.%] 이었다, 전류밀도가 낮아질수록 Ni과 Cu량은 증가하였다. 구리 농도가 증가하면 표면조도는 60 nm로 변화하였다.

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Effects of Ni addition on continuous cooling transformation behavior of low carbon HSLA steels (저탄소${\cdot}$저합금 강의 연속 냉각 변태에 미치는 Ni의 영향)

  • Kang J. S.;Jun J. H.;Park C. G.
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 2005.10a
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    • pp.456-459
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    • 2005
  • Continuous cooling transformation behaviors were studied fur low carbon HSLA steels containing three different level $(1\~3\;wt\%)$ of Ni addition. Thermo-mechanical processing (TMP) simulations to construct continuous cooling (CCT) diagram were conducted by using Gleeble system. As cooling rate increased, pearlite, granular bainite, acicular ferrite, bainitic ferrite and lath martensite were transformed from deformed austenite. Fully bainitic microstructure were developed at all cooling rate condition in high Ni containing steel due to hardenability increasing effects of Ni. Ni also influenced the transformation kinetics. At the slowest cooling rate of $0.3^{\circ}C/s$, transformation delayed with decreasing Ni contents because of the diffusion of substitutional alloy elements. However, cooling rate slightly increased to $1^{\circ}C/s$, transformation kinetics accelerated with decreasing Ni contents because nucleation of bainite was sluggish due to hardening of residual austenite.

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Exchange anisotropy depending on Interfacial Structure of the NiO/NiFe bilayers

  • Suh, S.J.;Kwak, J.O.;J.C.Ro;Kim, Y.S.;Park, G.S.
    • Proceedings of the Korea Association of Crystal Growth Conference
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    • 1998.06a
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    • pp.87-90
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    • 1998
  • ABSTRACT- we have analyzed the effect of microstructure and interface conditions on the anisotropic exchange filelds of NiO/NiFe bilayers. The NiO films were deposited by R.F. magentron sputtering. By using different atgon pressure NiO Films, Grain Size And Surface Roughness Of NiO can be manipulated. The exchange field is enhanced in the small granined NiO And This Increment Is Based On The Formation Of Small Domains In NiO

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Study on Accumulation of Ni in Seedlings and Growth rate of Salix reichardtii by Hydroponic Culture in Ni Solution (수경재배에 의한 Salix reichardtii 묘의 생장 및 부위별 Ni축적에 관한 연구)

  • Lee, Chang-Heon;Lim, Yu-Mi
    • Journal of Korean Society of Forest Science
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    • v.99 no.3
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    • pp.292-297
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    • 2010
  • This study was carried out to provide preliminary data to purify contaminated sites by nickel (Ni). After rooted cuttings of Salix reichardtii had been grown in Ni solution (hydroponic culture), pH changes in the solution and the accumulated Ni amount in plant parts were measured and analyzed. When the Ni concentration was low enough for S. reichardtii cuttings to grow well, the pH value of the solution decreased considerably. As the Ni concentration got higher, the plant growth got poorer and the pH value decreased slowly. Roots accumulated the highest Ni amount. Leaves and stems followed after. When stems were older, the accumulated Ni amount was lower. more Ni was accumulated in the plant parts which had more flexible tissue and live cells. As the Ni concentration in solution got higher up to 50.0 ${\mu}mol$/L, so did the Ni accumulation in the plant parts. However, the plant individuals nearly died and the Ni accumulation tended to drop when the Ni concentration in solution was 100.0 ${\mu}mol$/L. The rooted cuttings of S. reichardtii grew poorer as the Ni concentration in solution got higher. The plants in solution with 100.0 ${\mu}mol$/L of Ni were practically dead in four weeks.

Synthesis of Ni-YSZ cermets for SOFC by glycine nitrate process (Glycine nitrate process에 의한 SOFC용 Ni-YSZ cermets 제조)

  • Lee, Tae-Suk;Ko, Jung-Hoon;Kim, Bok-Hee
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.20 no.6
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    • pp.289-294
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    • 2010
  • Ni-YSZ (Yttria Stabilized Zirconia) composite powders for SOFC were fabricated by glycine nitrate process. $ZrO(NO_3)_2{\cdot}2H_2O$, $Y(NO_3)_3{\cdot}6H_2O$, $Ni(NO_3)_2{\cdot}6H_2O$ and glycine were chosen as the starting materials. The structural properties of the sintered Ni-YSZ cermets have been investigated with respect to the volume contents of Ni. A porous microstructure consisting of homogeneously distributed Ni and YSZ phases together with well-connected grains was observed. The sintered Ni-YSZ cermets showed a porous microstructure consists of homogeneously distributed Ni and YSZ phases and the grains were well-connected. It was found that the open porosity is sensitive to the volume content of Ni. The Ni-YSZ cermet containing 35 vol% Ni seems to be suitable for the electrode material of SOFC since it provides sufficient open porosity higher than 30%.

The Effects of Deposition Rates on Exchange Coupling and Magnetoresistance in NiO Spin-Valve Films

  • D. G. Hwang;Park, C. M.;Lee, S. S.;Lee, K. A.
    • Journal of Magnetics
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    • v.2 no.4
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    • pp.143-146
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    • 1997
  • The effects of deposition rate on exchange coupling field Hex and coercive field Hc in NiO spin-valves are discussed. The Hex and Hc increased with deposition rate of NiO film. The rms roughnesses of the NiO deposited at 6 ${\AA}$/min (NiO-Low) and 30${\AA}$/min (NiO-High) were almost similar, however, the short-range roughness increased with the deposition rate. The Hex, Hc and surface morphologies for the modulated NiO spin-valve films such as NiO-Low\NiO-High\NiO-Low and NiO-High\NiO-Low were investigated.

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The Effect of K Promoter on Ni-Co (Bimetallic) Catalyst for Dry Methane Reforming

  • Dharmasaroja, Nichthima;Phongaksorn, Monrudee;Tungkamani, Sabaithip;Ratana, Tanakorn;Sornchammi, Thana
    • International Journal of Advanced Culture Technology
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    • v.3 no.2
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    • pp.110-117
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    • 2015
  • 10 wt% (Ni-Co) catalysts with different Ni and Co content : 10%Ni, 9%Ni1%Co, 7%Ni3%Co, 5%Ni5%Co, 3%Ni7%Co, and 10%Co; were prepared using sol-gel method followed by incipient wetness impregnation method. To investigate the catalytic activity including the stability, dry methane reforming were demonstrated over the pelletized catalysts at $620^{\circ}C$ under atmospheric pressure in a $CH_4:CO_2:N_2$ feedstock for 360 min. The results showed that bimetallic catalysts with the Co content equal to or greater than 3% were more stable than monometallic catalysts (10%Ni and 10%Co). The temperature programmed hydrogenation interpreted that the additional of Co into Ni catalyst improved the carbon resistance from methane cracking. Promoted this type of bimetallic catalyst using 1wt% K (trimetallic catalyst) prevented the carbon formation on the catalyst. The temperature programmed desorption of $CO_2$ indicated that this trimetallic catalyst has a greater number of strong basic sites. Moreover, the appearance of K lowered the number of weak basic sites and decreased the conversion of methane by 12 %.