• Title/Summary/Keyword: Energy Diffusion

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Effect of Anode Gas Channel Height on Gas Diffusion and Cell Performance in a Molten Carbonate Fuel Cell (용융탄산염 연료전지 연료극 기체 유로 높이에 따른 가스 확산 및 단전지 성능 변화 연구)

  • Lee, Jung-Hyun;Kim, Do-Hyung;Kim, Beum-Ju;Kang, Seung-Won;Lim, Hee-Chun
    • Transactions of the Korean hydrogen and new energy society
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    • v.20 no.6
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    • pp.479-484
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    • 2009
  • The effect of anode gas channel height on gas diffusion and cell performance in a 100 $cm^2$ class molten carbonate single cell is investigated. Single cell separators with three different channel height are used. The effect of the gas channel height on the distribution of the reactive gas concentration is evaluated by the two-dimensional concentration diffusion equation. The overpotential caused by concentration drop with different channel height is estimated by the voltage decay related to diffusion of reactants, well known as concentration polarization, using limiting current density. The estimation could have the possibility to identify the reactant mass transfer polarization in the complicate factors of the overall electrodes.

Diffusion Coefficient of Ag(I) ion in the Concentrated Nitric Acid Solution (고농도 질산용액에서 Ag(I) 이온의 확산계수 측정)

  • Park Sang Yoon;Choi Wang Kyu;Lee Kune Woo;Moon Jei Kwon;Oh Won Zin
    • Journal of the Korean Electrochemical Society
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    • v.2 no.2
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    • pp.93-97
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    • 1999
  • From the anodic peak currents of cyclic voltammograms for Ag(I)/Ag(II) couple obtained with the variation of nitric acid concentration, Ag(I) concentration and solution temperature at a Pt electrode in concentrated nitric acid solutions, the diffusion coefficients of Ag(I) ion were evaluated to estimate the limiting current density of Ag(II)-mediated electrochemical oxidation (MEO) process, which has been effectively used for the complete destruction of hazardous organic materials. The results showed that, due to the water decomposition reaction which occurred simultaneously with the Ag(I) ion oxidation, background subtractions for the cyclic voltammograms were required to estimate the correct peak currents. The empirical relationship for the diffusion coefficient of Ag(I) was suggested as a function of solution viscosity and temperature.

Synthesis of 58Ni Target and Co Diffused Rh Composite for Application of Mössbauer Source (뫼스바우어선원 적용을 위한 58Ni 표적체 및 Co가 확산된 Rh복합재 제조)

  • Uhm, Young Rang;Choi, Sang Mu;Kim, Jong-bum;Son, Kwang Jae
    • Journal of Powder Materials
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    • v.22 no.6
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    • pp.432-437
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    • 2015
  • The en-riched $^{58}Ni$ powders are dissolved in acid solution and coated on a Cu target for proton irradiation at cyclotron to produce $^{57}Co$ radioisotope. The condition of the plating bath and the coating process are determined using the en-riched powders. To establish the coating conditions for $^{57}Co$, non-radioactive Co ions are dissolved in an acid solution and electroplated on to a rhodium plate. The thermal diffusion of electroplated Co into a rhodium matrix was studied to apply a $^{57}Co$ Mssbauer source. The diffusion depth from surface to matrix of Co is depended on the annealing temperature and time. The deposited Co atoms diffuse completely into a rhodium (Rh) matrix without substantial loss at an annealing temperature of 1200 for 4 hours.

Analysis of n+ emitter properties using Dopant Pastes for Crystalline Silicon Solar Cells (결정질 실리콘 태양전지에 적용하기 위한 Dopant Pastes의 n+ emitter 특성 분석)

  • Lee, Ji-Hun;Cho, Kyeong-Yeon;Choi, Jun-Young;Lee, Soo-Hong
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2007.11a
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    • pp.15-16
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    • 2007
  • The high efficiency and low cost solar cells in order to it applied a dopant pastes diffusion process. The dopant pastes diffusion process which it uses is easily applied in screen-printing solar cells output line. in this paper, it used the Ferro 99-038 phosphorus diffusion pastes source and it analyzed a sheet resistance and a uniformity degree. And it knew the quality of the sheet resistance which it follows in temperature and time condition. The temperature variable it let and it fixed the time in 7 minutes. It will be able to measure the sheet resistance of $40({\Omega}/sq),\;30({\Omega}/sq),\; 20({\Omega}/sq)$. also average uniformity of the sheet resistance was below 5%.

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A study on the heat dissipation characteristic of thermal interface materials with Graphene, Cu and Ag nano powders (Graphene, Cu와 Ag 나노 파우더를 이용한 열전도재의 방열 특성에 관한 연구)

  • Park, Sang-Hyeok;Im, Sung-Hoon;Kim, Hyun-Ji;Noh, Jung-Pil;Huh, Sun-Chul
    • Journal of the Korean Society of Industry Convergence
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    • v.22 no.6
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    • pp.767-773
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    • 2019
  • The thermal diffusion performance of the electronic device is a factor for evaluating the stability of the electronic device. Therefore, many of research have been conducted to improve the thermal characteristics of thermal interface materials, which are materials for thermal diffusion of electronic products. In this study, nano thermal grease was prepared by blending graphene, silver and copper nano powders into a thermal grease, a type of thermal interface materials, and the heat transfer rate was measured and compared for the purpose of investigating the improved thermal properties. As a result, the thermal properties were good in the order of graphene, silver and copper, which is thought to be due to the different thermal properties of the nano powder itself.