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John Newman - One of the best experts on this subject based on the ideXlab platform.

  • simulation of the direct methanol fuel cell ii modeling and data analysis of transport and kinetic phenomena
    Journal of The Electrochemical Society, 2002
    Co-Authors: Jeremy P Meyers, John Newman
    Abstract:

    A mathematical model that describes the transport of species in a multicomponent membrane is presented. The transport is described by Concentrated-Solution theory, and the electrochemical potential driving forces are described by a thermodynamic framework set forth in the first paper in this series. A kinetic model is developed to describe methanol oxidation kinetics on Pt-Ru catalysts. Physical properties are estimated by correlation of data in the literature and by simulation of methanol electrolysis experiments. This model provides the framework for direct methanol fuel cell simulation and design in the third paper in this series.

  • simulation of the direct methanol fuel cell ii modeling and data analysis of transport and kinetic phenomena
    Journal of The Electrochemical Society, 2002
    Co-Authors: Jeremy P Meyers, John Newman
    Abstract:

    A mathematical model that describes the transport of species in a multicomponent membrane is presented. The transport is described by Concentrated-Solution theory, and the electrochemical potential driving forces are described by a thermodynamic framework set forth in the first paper in this series. A kinetic model is developed to describe methanol oxidation kinetics on Pt-Ru catalysts. Physical properties are estimated by correlation of data in the literature and by simulation of methanol electrolysis experiments. This model provides the framework for direct methanol fuel cell simulation and design in the third paper in this series. © 2002 The Electrochemical Society. All rights reserved.

G J M Janssen - One of the best experts on this subject based on the ideXlab platform.

  • a phenomenological model of water transport in a proton exchange membrane fuel cell
    Journal of The Electrochemical Society, 2001
    Co-Authors: G J M Janssen
    Abstract:

    A steady-state, two-dimensional model is presented and discussed that describes the water transport in a proton exchange membrane fuel cell. Concentrated Solution theory is used to describe the transport of water in the membrane, and of water vapor and liquid water in the electrodes. The inclusion of the liquid water transport into the model turned out to be essential for explaining recent experimental results on the effective drag coefficient and its dependence on operating conditions as well as on variations of the components that constitute the membrane electrode assembly.

Jeremy P Meyers - One of the best experts on this subject based on the ideXlab platform.

  • simulation of the direct methanol fuel cell ii modeling and data analysis of transport and kinetic phenomena
    Journal of The Electrochemical Society, 2002
    Co-Authors: Jeremy P Meyers, John Newman
    Abstract:

    A mathematical model that describes the transport of species in a multicomponent membrane is presented. The transport is described by Concentrated-Solution theory, and the electrochemical potential driving forces are described by a thermodynamic framework set forth in the first paper in this series. A kinetic model is developed to describe methanol oxidation kinetics on Pt-Ru catalysts. Physical properties are estimated by correlation of data in the literature and by simulation of methanol electrolysis experiments. This model provides the framework for direct methanol fuel cell simulation and design in the third paper in this series.

  • simulation of the direct methanol fuel cell ii modeling and data analysis of transport and kinetic phenomena
    Journal of The Electrochemical Society, 2002
    Co-Authors: Jeremy P Meyers, John Newman
    Abstract:

    A mathematical model that describes the transport of species in a multicomponent membrane is presented. The transport is described by Concentrated-Solution theory, and the electrochemical potential driving forces are described by a thermodynamic framework set forth in the first paper in this series. A kinetic model is developed to describe methanol oxidation kinetics on Pt-Ru catalysts. Physical properties are estimated by correlation of data in the literature and by simulation of methanol electrolysis experiments. This model provides the framework for direct methanol fuel cell simulation and design in the third paper in this series. © 2002 The Electrochemical Society. All rights reserved.

Bradley D. Olsen - One of the best experts on this subject based on the ideXlab platform.

  • improved ordering in low molecular weight protein polymer conjugates through oligomerization of the protein block
    Biomacromolecules, 2018
    Co-Authors: Justin M Paloni, Eric Miller, Hadley D Sikes, Bradley D. Olsen
    Abstract:

    The self-assembly of protein-polymer conjugates incorporating oligomers of a small, engineered high-affinity binding protein, rcSso7d.SA, is studied to determine the effect of protein oligomerization on nanoscale ordering. Oligomerization enables a systematic increase in the protein molar mass without changing its overall folded structure, leading to a higher driving force for self-assembly into well-ordered structures. Though conjugates of monomeric rcSso7d.SA are found to only exist in disordered states, oligomers of this protein linked to a poly( N-isopropylacrylamide) (PNIPAM) block self-assemble into lamellar nanostructures. Conjugates of trimeric and tetrameric rcSso7d.SA are observed to produce the strongest ordering in Concentrated Solution, displaying birefringent lamellae at concentrations as low as 40 wt %. In highly Concentrated Solution, the oligomeric rcSso7d.SA-PNIPAM block copolymers exhibit ordering and domain spacing trends atypical from that of most block copolymers. Fluorescent binding assays indicate that oligomerized protein blocks retain binding functionality and exhibit limits of detection up to three times lower than that of surface-immobilized protein sensors. Therefore, oligomerization of the protein block in these block copolymers serves as an effective method to improve both nanoscale ordering and biosensing capabilities.

  • phase transitions in Concentrated Solution self assembly of globular protein polymer block copolymers
    Soft Matter, 2013
    Co-Authors: Bradley D. Olsen
    Abstract:

    The phase behaviour of mCherry-b-PNIPAM (mChP) block copolymers with four different PNIPAM coil fractions is investigated in Concentrated aqueous Solution as a function of both concentration and temperature, demonstrating both order–order transitions (OOTs) and order–disorder transitions (ODTs) in globular protein–polymer block copolymers. Independent of coil volume fraction from 0.25 to 0.70, the temperature–concentration phase diagrams share several common features. At low concentrations, mCherry-b-PNIPAM forms a homogeneous disordered phase, and macrophase separation into an ordered conjugate-rich phase and a solvent-rich phase is observed at temperatures above the PNIPAM thermoresponsive transition temperature. mChP Solutions are also observed to undergo a low-temperature ODT driven by increasing concentration. The order–disorder transition concentration (ODTC) behaviour of mChP is minimized for symmetric conjugates, suggesting that repulsive solvent-mediated protein–polymer interactions provide a driving force for self-assembly. Both coil fraction and solvent selectivity have large effects on the morphologies formed—disordered micelles, hexagonally packed cylinders, lamellae, and perforated lamellae are identified with the combination of small-angle X-ray scattering (SAXS), depolarized light scattering (DPLS), turbidimetry, and differential scanning calorimetry (DSC). An OOT is observed upon increasing temperature for three of the studied coil fractions at concentrations of 40–50 wt% due to changing solvent selectivity. SANS contrast-matching experiments show that water is weakly selective for PNIPAM at low temperatures and strongly selective for mCherry at high temperatures.

Z Ogumi - One of the best experts on this subject based on the ideXlab platform.

  • interfacial reactions between graphite electrodes and propylene carbonate based Solutions electrolyte concentration dependence of electrochemical lithium intercalation reaction
    Journal of Power Sources, 2008
    Co-Authors: Soonki Jeong, Minoru Inaba, Yasutoshi Iriyama, Z Ogumi
    Abstract:

    Abstract This study examines the electrochemical reactions occurring at graphite negative electrodes of lithium-ion batteries in a propylene carbonate (PC) electrolyte that contains different concentrations of lithium salts such as, LiClO 4 , LiPF 6 or LiN(SO 2 C 2 F 5 ) 2 . The electrode reactions are significantly affected by the electrolyte concentration. In Concentrated Solutions, lithium ions are reversibly intercalated within the graphite to form stage 1 lithium–graphite intercalation compounds (Li–GICs), regardless of the lithium salt used. On the other hand, electrolyte decomposition and exfoliation of the graphene layers occur continuously in the low-concentration range. In situ analysis with atomic force microscopy reveals that a thin film (thickness of ∼8 nm) forms on the graphite surface in a Concentrated Solution, e.g., 3.27 mol kg −1 LiN(SO 2 C 2 F 5 ) 2 /PC, after the first potential cycle between 2.9 and 0 V versus Li + /Li. There is no evidence of the co-intercalation of solvent molecules in the Concentrated Solution.