• Title/Summary/Keyword: membrane transport

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Modeling of Water Transport in Porous Membrane for PEMFC Humidifer (PEMFC 가습기 용 다공성 중공사막의 물전달 모델링)

  • Hwang, Jun Y.;Park, J.Y.;Kang, K.;Kim, J.H.;Kim, K.J.;Lee, M.S.
    • 한국신재생에너지학회:학술대회논문집
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    • 2011.05a
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    • pp.96.2-96.2
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    • 2011
  • Water transport through the microporous membrane was modeled considering capillary condensation as well as capillary flow in porous media as a function of pore diameter and relative humidity at the surface. The present model was adopted by the numerical simulation of non-isothermal, non-homogenous flow in a shell and tube typed gas to gas membrane humidifier for PEMFC (proton exchange membrane fuel cell) and the result shows good agreement with experimental data.

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Transport Characteristics of Organic Anions through Poly (1-methyl-4vinylpyridium iodide-co-styrene) Membrane (Poly(1-methyl-4-vinylpyridium iodide-co-styrene)막을 통한 유기음이온의 투과특성)

  • 이광재;한정우박돈희조영일
    • KSBB Journal
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    • v.6 no.2
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    • pp.207-213
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    • 1991
  • In this study poly (1-methyl-4-vinylpyridinium iodide-co-styrene) membrane with pyridinium cation as a fixed carrier was synthesized and the transport characteristics of the membrane was examined over various factors. As the concentration of the fixed carrier in the membrane was increased, the water content was increased. Meanwhile, the counter current of the organic anion and the chloride ion, the following results were obtained. Initial flux of Cl-, organic anion and Na+ decreased with the increasing thickness of membrane, and as the concentration of the fixed carrier increases, the initial flux of Cl- and organic anion increase but the initial flux of Na+ decreased. The flux equation of the organic anion, CCl3COO- was obtained from saturation kinetics as follows;$V_{o}=\frac{(8.67{\times}10^{-5}){\cdot}[NaCl]}{9.63{\times}10^{-2}+[NaCl]} mol/cm^2h$

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The Correlation between Gas Transport Properties and Physical Properties of Modified Polysulfones (변형 폴리술폰의 기체 투과 성질과 물리적 성질의 상관관계)

  • ;;;;;Guiver, Michael D.;R
    • Proceedings of the Membrane Society of Korea Conference
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    • 1997.10a
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    • pp.67-68
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    • 1997
  • 1. Introduction : Gas transport through dense polymeric membranes is predominantly determined by the chain packing density as well as the chain flexibility. Thus, improved permeation properties can be obtained by controlling these two factors. In this work, the introduction of bulky substituents was attempted to improve permeation properties. Polysulfone, widely used material for gas separation membrane, was the starting material of this modification. Gas transport properties of resulting modified polysulfones were examined, and the improved properties were explained by probing the change of physical properties.

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Pore-network Study of Liquid Water Transport through Multiple Gas Diffusion Medium in PEMFCs (고분자 연료전지의 다공성층 내에서의 액상수분 이동에 관한 공극-네트워크 해석 연구)

  • Kang, Jung-Ho;Lee, Sang-Gun;Nam, Jin-Hyun;Kim, Charn-Jung
    • 한국전산유체공학회:학술대회논문집
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    • 2011.05a
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    • pp.46-53
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    • 2011
  • Water is continuously produced in polymer electrolyte membrane fuel cell (PEMFC), and is transported and exhausted through polymer electrolyte membrane (PEM), catalyst layer (CL), microporous layer (MPL), and gas diffusion layer (GDL). The low operation temperatures of PEMFC lead to the condensation of water, and the condensed water hinders the transport of reactants in porous layers (MPL and GDL). Thus, water flooding is currently one of hot issues that should be solved to achieve higher performance of PEMFC. This research aims to study liquid water transport in porous layers of PEMFC by using pore-network model, while the microscale pore structure and hydrophilic/hydrophobic surface properties of GDL and MPL were fully considered.

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Facilitated Transport of Cr(VI) through a Supported Liquid Membrane with a Carrier

  • Park, Sang-Wook;Lee, Jae-Wook;Kim, Sung-Soo;Choi, Byoung-Sik
    • Journal of the Korean Applied Science and Technology
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    • v.20 no.2
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    • pp.154-164
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    • 2003
  • This paper has applied a simple model to the mass transfer mechanism of Cr(VI) with crownether in a batch-type, supported liquid membrane module. Concentration at pH 3 are as follows : 0.012 kmol/$m^3{\le}$18-crown-6${\le}$0.036 kmol/$m^3$ and 20 g/$m^3{\le}$ Cr(VI)${\le}$500 g/$m^3$. The measured values of forward- and backward-reaction rate constants between Cr(VI) and 18-crown-6 were used to simulate the model with the mass conservation equation and associated boundary conditions. Comparison between the experimental and simulated facilitated factor of Cr(VI) transport led to classification of reaction regions.

Modulation of Phytotropin Receptors by Fluoride and ATP

  • Nam, Myung-Hee;Kang, Bin-G.
    • BMB Reports
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    • v.28 no.6
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    • pp.552-555
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    • 1995
  • Treatment of microsomal vesicles isolated from etiolated Pisum sativum L cv. Alaska epicotyl tissue with agents inhibiting protein dephosphorylation, namely NaF and/or ATP, resulted in increased binding of the phytotropin NPA to the putative auxin efflux carriers localized on the plasma membrane. The phytotropin effect was especially conspicuous if the vesicles were simultaneously treated with Triton X-100. Kinetic analysis of the binding indicated the existance of two distinct sites for NPA, each having different affinities. Increased binding of the phytotropin to the membrane where protein dephosphorylation was inhibited was attributable to the increased ligand affinity of both sites. Treatment of tissue segments with flubride was found to enhance in vivo auxin transport. Implications of covalent modification of the auxin efflux carrier complex for the regulation of membrane transport of auxin molecules are discussed.

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