National Library of Energy BETA

Sample records for membrane transport proteins

  1. How the Membrane Protein AmtB Transports Ammonia

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    How the Membrane Protein AmtB Transports Ammonia Print Membrane proteins provide molecular-sized entry and exit portals for the various substances that pass into and out of cells....

  2. How the Membrane Protein AmtB Transports Ammonia

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Membrane Protein AmtB Transports Ammonia Print Wednesday, 25 May 2005 00:00 Membrane proteins provide molecular-sized entry and exit portals for the various substances that pass...

  3. Structures for Three Membrane Transport Proteins Yield Functional...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Structures for Three Membrane Transport Proteins Yield Functional Insights Print Cells depend on contact with their outside environment in order to thrive. Two examples illustrate...

  4. Protein Flips Lipids Across Membranes

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Protein Flips Lipids Across Membranes Print Found ubiquitously in both bacteria and humans, membrane proteins of the adenosine triphosphate (ATP)-binding cassette (ABC) transporter...

  5. Aquaporins comprise a family of water-transporting membrane proteins. All aquaporins are efficient water transporters, while

    E-Print Network [OSTI]

    de Groot, Bert

    . Further insights, particularly with respect to the dynamics of water permeation and the filter mechanism509 Aquaporins comprise a family of water-transporting membrane proteins. All aquaporins are efficient water transporters, while sustaining strict selectivity, even against protons, thereby maintaining

  6. How the Membrane Protein AmtB Transports Ammonia

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    the hydrophobic bilayer, while NH3 is not. Passage of uncharged NH3 would not result in a net change of protons across the membrane nor would it change the membrane potential, thus...

  7. How the Membrane Protein AmtB Transports Ammonia

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration would likeUniverse (JournalvivoHigh energyHighlandWorkshop-SummerHow is the DataHow the Membrane

  8. OXYGEN TRANSPORT CERAMIC MEMBRANES

    SciTech Connect (OSTI)

    Dr. Sukumar Bandopadhyay; Dr. Nagendra Nagabhushana

    2000-10-01

    This is the third quarterly report on oxygen Transport Ceramic Membranes. In the following, the report describes the progress made by our university partners in Tasks 1 through 6, experimental apparatus that was designed and built for various tasks of this project, thermodynamic calculations, where applicable and work planned for the future. (Task 1) Design, fabricate and evaluate ceramic to metal seals based on graded ceramic powder/metal braze joints. (Task 2) Evaluate the effect of defect configuration on ceramic membrane conductivity and long term chemical and structural stability. (Task 3) Determine materials mechanical properties under conditions of high temperatures and reactive atmospheres. (Task 4) Evaluate phase stability and thermal expansion of candidate perovskite membranes and develop techniques to support these materials on porous metal structures. (Task 5) Assess the microstructure of membrane materials to evaluate the effects of vacancy-impurity association, defect clusters, and vacancy-dopant association on the membrane performance and stability. (Task 6) Measure kinetics of oxygen uptake and transport in ceramic membrane materials under commercially relevant conditions using isotope labeling techniques.

  9. Hydrogen transport membranes

    DOE Patents [OSTI]

    Mundschau, Michael V.

    2005-05-31

    Composite hydrogen transport membranes, which are used for extraction of hydrogen from gas mixtures are provided. Methods are described for supporting metals and metal alloys which have high hydrogen permeability, but which are either too thin to be self supporting, too weak to resist differential pressures across the membrane, or which become embrittled by hydrogen. Support materials are chosen to be lattice matched to the metals and metal alloys. Preferred metals with high permeability for hydrogen include vanadium, niobium, tantalum, zirconium, palladium, and alloys thereof. Hydrogen-permeable membranes include those in which the pores of a porous support matrix are blocked by hydrogen-permeable metals and metal alloys, those in which the pores of a porous metal matrix are blocked with materials which make the membrane impervious to gases other than hydrogen, and cermets fabricated by sintering powders of metals with powders of lattice-matched ceramic.

  10. Protein Flips Lipids Across Membranes

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Across Membranes Print Wednesday, 26 October 2005 00:00 Found ubiquitously in both bacteria and humans, membrane proteins of the adenosine triphosphate (ATP)-binding cassette...

  11. OXYGEN TRANSPORT CERAMIC MEMBRANES

    SciTech Connect (OSTI)

    Dr. Sukumar Bandopadhyay; Dr. Nagendra Nagabhushana

    2003-01-01

    In the present quarter, experiments are presented on ceramic/metal interactions of Zirconia/Ni-B-Si system and with a thin Ti coating deposited on zirconia surface. Processing of perovskites of LSC, LSF and LSCF composition for evaluation of mechanical properties as a function of environment are begun. The studies are to be in parallel with LSFCO composition to characterize the segregation of cations and slow crack growth in environmental conditions. La{sub 1-x}Sr{sub x}FeO{sub 3-d} has also been characterized for paramagnetic ordering at room temperature and the evolution of magnetic moments as a function of temperature are investigated. Investigation on the thermodynamic properties of the membrane materials are continued to develop a complete model for the membrane transport.

  12. Oxygen Transport Ceramic Membranes

    SciTech Connect (OSTI)

    S. Bandopadhyay; N. Nagabhushana

    2003-08-07

    In the present quarter, experiments are presented on ceramic/metal interactions of Zirconia/ Ni-B-Si system and with a thin Ti coating deposited on zirconia surface. Existing facilities were modified for evaluation of environmental assisted slow crack growth and creep in flexural mode. Processing of perovskites of LSC, LSF and LSCF composition were continued for evaluation of mechanical properties as a function of environment. These studies in parallel to those on the LSFCO composition is expect to yield important information on questions such as the role of cation segregation and the stability of the perovskite structure on crack initiation vs. crack growth. Studies have been continued on the La{sub 1-x}Sr{sub x}FeO{sub 3-d} composition using neutron diffraction and TGA studies. A transition from p-type to n-type of conductor was observed at relative low pO{sub 2}, at which the majority carriers changed from the holes to electrons because of the valence state decreases in Fe due to the further loss of oxygen. Investigation on the thermodynamic properties of the membrane materials are continued to develop a complete model for the membrane transport. Data obtained at 850 C show that the stoichiometry in La{sub 0.2}Sr{sub 0.8}Fe{sub 0.8}Cr{sub 0.2}O{sub 3-x} vary from {approx}2.85 to 2.6 over the pressure range studied. From the stoichiometry a lower limit of 2.6 corresponding to the reduction of all Fe{sup 4+} to Fe{sup 3+} and no reduction of Cr{sup 3+} is expected.

  13. Hydrogen Bond Shaping of Membrane Protein Structure

    E-Print Network [OSTI]

    Cao, Zheng

    2013-01-01

    Bowie JU (2011) Membrane protein folding: how important areRadford SE (2000) Protein folding mechanisms: new methodset al. (2003) Membrane protein folding: beyond the two stage

  14. Nanoengineered membranes for controlled transport

    DOE Patents [OSTI]

    Doktycz, Mitchel J. (Oak Ridge, TN) [Oak Ridge, TN; Simpson, Michael L. (Knoxville, TN) [Knoxville, TN; McKnight, Timothy E. (Greenback, TN) [Greenback, TN; Melechko, Anatoli V. (Oak Ridge, TN) [Oak Ridge, TN; Lowndes, Douglas H. (Knoxville, TN) [Knoxville, TN; Guillorn, Michael A. (Knoxville, TN) [Knoxville, TN; Merkulov, Vladimir I. (Oak Ridge, TN) [Oak Ridge, TN

    2010-01-05

    A nanoengineered membrane for controlling material transport (e.g., molecular transport) is disclosed. The membrane includes a substrate, a cover definining a material transport channel between the substrate and the cover, and a plurality of fibers positioned in the channel and connected to an extending away from a surface of the substrate. The fibers are aligned perpendicular to the surface of the substrate, and have a width of 100 nanometers or less. The diffusion limits for material transport are controlled by the separation of the fibers. In one embodiment, chemical derivitization of carbon fibers may be undertaken to further affect the diffusion limits or affect selective permeability or facilitated transport. For example, a coating can be applied to at least a portion of the fibers. In another embodiment, individually addressable carbon nanofibers can be integrated with the membrane to provide an electrical driving force for material transport.

  15. Membrane Protein Crystallization in Lipidic Mesophases. Hosting...

    Office of Scientific and Technical Information (OSTI)

    CATIONS; CRYSTALLIZATION; CRYSTALLOGRAPHY; CRYSTALS; HOST; LIPIDS; MEMBRANE PROTEINS; MEMBRANES; NUCLEAR MAGNETIC RESONANCE; PEPTIDES; RANGE; SHAPE; SIZE Word Cloud More...

  16. A survey of integral ?-helical membrane proteins

    E-Print Network [OSTI]

    2009-01-01

    opti- mum eukaryotic integral membrane proteins forLarge-scale identi?cation of yeast integral membrane protein009-9069-8 A survey of integral a-helical membrane proteins

  17. Oxygen Transport Ceramic Membranes

    SciTech Connect (OSTI)

    S. Bandopadhyay; T. Nithyanantham; X.-D Zhou; Y-W. Sin; H.U. Anderson; Alan Jacobson; C.A. Mims

    2006-05-01

    In this quarter a systematic analysis on the decomposition behavior of the OTM membranes at air and nitrogen were initiated to understand the structural and stoichiometric changes associated with elevated temperatures. Evaluation of the flexural strengths using 4-point bend test was also started for the dual phase membranes. Initial results on the synthesis of dual phase composite materials have been obtained. The measurements have focused on the compatibility of mixed conductors with the pure ionic conductors yttria stabilized zirconia (YSZ) and gadolinium doped ceria (GDC). The initial results obtained for three different mixed conductors suggest that (GDC) is the better choice. A new membrane permeation system has been designed and tested and sintering studies of biphasic systems are in progress.

  18. Composite oxygen transport membrane

    DOE Patents [OSTI]

    Christie, Gervase Maxwell; Lane, Jonathan A.

    2014-08-05

    A method of producing a composite oxygen ion membrane and a composite oxygen ion membrane in which a porous fuel oxidation layer and a dense separation layer and optionally, a porous surface exchange layer are formed on a porous support from mixtures of (Ln.sub.1-xA.sub.x).sub.wCr.sub.1-yB.sub.yO.sub.3-.delta. and a doped zirconia. In the porous fuel oxidation layer and the optional porous surface exchange layer, A is Calcium and in the dense separation layer A is not Calcium and, preferably is Strontium. Preferred materials are (La.sub.0.8Ca.sub.0.2).sub.0.95Cr.sub.0.5Mn.sub.0.5O.sub.3-.delta. for the porous fuel oxidation and optional porous surface exchange layers and (La.sub.0.8Sr.sub.0.2).sub.0.95Cr.sub.0.5Fe.sub.0.5O.sub.3-.delta. for the dense separation layer. The use of such materials allows the membrane to sintered in air and without the use of pore formers to reduce membrane manufacturing costs. The use of materials, as described herein, for forming the porous layers have application for forming any type of porous structure, such as a catalyst support.

  19. Ion transport through cell membrane channels

    E-Print Network [OSTI]

    Jan Gomulkiewicz; Jacek Miekisz; Stanislaw Miekisz

    2007-06-05

    We discuss various models of ion transport through cell membrane channels. Recent experimental data shows that sizes of ion channels are compared to those of ions and that only few ions may be simultaneously in any single channel. Theoretical description of ion transport in such channels should therefore take into account interactions between ions and between ions and channel proteins. This is not satisfied by macroscopic continuum models based on Poisson-Nernst-Planck equations. More realistic descriptions of ion transport are offered by microscopic Brownian and molecular dynamics. One should also take into account a dynamical character of the channel structure. This is not yet addressed in the literature

  20. OXYGEN TRANSPORT CERAMIC MEMBRANES

    SciTech Connect (OSTI)

    Dr. Sukumar Bandopadhyay; Dr. Nagendra Nagabhushana

    2000-07-01

    This is the fourth quarterly report on a new study to develop a ceramic membrane/metal joint. The first experiments using the La-Sr-Fe-O ceramic are reported. Some of the analysis performed on the samples obtained are commented upon. A set of experiments to characterize the mechanical strength and thermal fatigue properties of the joints has been designed and begun. Finite element models of joints used to model residual stresses are described.

  1. Membrane Transport Chloride Transport Across Vesicle and Cell

    E-Print Network [OSTI]

    Smith, Bradley D.

    Membrane Transport Chloride Transport Across Vesicle and Cell Membranes by Steroid-Based Receptors-established that molecules which transport cations across cell membranes (cationophores) can have potent biological effects of biological activity. Indeed, chloride transporters have direct medical potential as treatments for cystic

  2. Vertebrate Membrane Proteins: Structure, Function, and Insights from Biophysical Approaches

    E-Print Network [OSTI]

    Palczewski, Krzysztof

    Vertebrate Membrane Proteins: Structure, Function, and Insights from Biophysical Approaches DANIEL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46 B. Membrane proteins . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47 III. Interactions of proteins with membranes

  3. Membrane protein folding on the example of outer membrane protein A of Escherichia coli

    E-Print Network [OSTI]

    Kleinschmidt, Jörg H.

    Membrane protein folding on the example of outer membrane protein A of Escherichia coli J. H and mechanisms by which membrane proteins insert and fold into a biomem- brane have mostly been studiedA that involves at least three struc- turally distinct folding intermediates. Key words. Membrane protein folding

  4. Cell-free system for synthesizing membrane proteins cell free method for synthesizing membrane proteins

    DOE Patents [OSTI]

    Laible, Philip D; Hanson, Deborah K

    2013-06-04

    The invention provides an in vitro method for producing proteins, membrane proteins, membrane-associated proteins, and soluble proteins that interact with membrane-associated proteins for assembly into an oligomeric complex or that require association with a membrane for proper folding. The method comprises, supplying intracytoplasmic membranes from organisms; modifying protein composition of intracytoplasmic membranes from organism by modifying DNA to delete genes encoding functions of the organism not associated with the formation of the intracytoplasmic membranes; generating appropriate DNA or RNA templates that encode the target protein; and mixing the intracytoplasmic membranes with the template and a transcription/translation-competent cellular extract to cause simultaneous production of the membrane proteins and encapsulation of the membrane proteins within the intracytoplasmic membranes.

  5. Renaturing Membrane Proteins in the Lipid Cubic Phase, a Nanoporous...

    Office of Scientific and Technical Information (OSTI)

    Renaturing Membrane Proteins in the Lipid Cubic Phase, a Nanoporous Membrane Mimetic Citation Details In-Document Search Title: Renaturing Membrane Proteins in the Lipid Cubic...

  6. A survey of integral ?-helical membrane proteins

    E-Print Network [OSTI]

    2009-01-01

    cation of all human G-protein coupled receptors. However, avon Heijne G (2007) Membrane protein structure: predictionH (2007) Locating proteins in the cell using TargetP,

  7. Catalyst containing oxygen transport membrane

    DOE Patents [OSTI]

    Christie, Gervase Maxwell; Wilson, Jamie Robyn; van Hassel, Bart Antonie

    2012-12-04

    A composite oxygen transport membrane having a dense layer, a porous support layer and an intermediate porous layer located between the dense layer and the porous support layer. Both the dense layer and the intermediate porous layer are formed from an ionic conductive material to conduct oxygen ions and an electrically conductive material to conduct electrons. The porous support layer has a high permeability, high porosity, and a high average pore diameter and the intermediate porous layer has a lower permeability and lower pore diameter than the porous support layer. Catalyst particles selected to promote oxidation of a combustible substance are located in the intermediate porous layer and in the porous support adjacent to the intermediate porous layer. The catalyst particles can be formed by wicking a solution of catalyst precursors through the porous support toward the intermediate porous layer.

  8. Ion transport membrane module and vessel system

    DOE Patents [OSTI]

    Stein, VanEric Edward (Allentown, PA); Carolan, Michael Francis (Allentown, PA); Chen, Christopher M. (Allentown, PA); Armstrong, Phillip Andrew (Orefield, PA); Wahle, Harold W. (North Canton, OH); Ohrn, Theodore R. (Alliance, OH); Kneidel, Kurt E. (Alliance, OH); Rackers, Keith Gerard (Louisville, OH); Blake, James Erik (Uniontown, OH); Nataraj, Shankar (Allentown, PA); van Doorn, Rene Hendrik Elias (Obersulm-Willsbach, DE); Wilson, Merrill Anderson (West Jordan, UT)

    2008-02-26

    An ion transport membrane system comprising (a) a pressure vessel having an interior, an exterior, an inlet, and an outlet; (b) a plurality of planar ion transport membrane modules disposed in the interior of the pressure vessel and arranged in series, each membrane module comprising mixed metal oxide ceramic material and having an interior region and an exterior region, wherein any inlet and any outlet of the pressure vessel are in flow communication with exterior regions of the membrane modules; and (c) one or more gas manifolds in flow communication with interior regions of the membrane modules and with the exterior of the pressure vessel.The ion transport membrane system may be utilized in a gas separation device to recover oxygen from an oxygen-containing gas or as an oxidation reactor to oxidize compounds in a feed gas stream by oxygen permeated through the mixed metal oxide ceramic material of the membrane modules.

  9. Ion transport membrane module and vessel system

    DOE Patents [OSTI]

    Stein, VanEric Edward; Carolan, Michael Francis; Chen, Christopher M.; Armstrong, Phillip Andrew; Wahle, Harold W.; Ohrn, Theodore R.; Kneidel, Kurt E.; Rackers, Keith Gerard; Blake, James Erik; Nataraj, Shankar; van Doorn, Rene Hendrik Elias; Wilson, Merrill Anderson

    2007-02-20

    An ion transport membrane system comprising (a) a pressure vessel having an interior, an exterior, an inlet, and an outlet; (b) a plurality of planar ion transport membrane modules disposed in the interior of the pressure vessel and arranged in series, each membrane module comprising mixed metal oxide ceramic material and having an interior region and an exterior region, wherein any inlet and any outlet of the pressure vessel are in flow communication with exterior regions of the membrane modules; and (c) one or more gas manifolds in flow communication with interior regions of the membrane modules and with the exterior of the pressure vessel. The ion transport membrane system may be utilized in a gas separation device to recover oxygen from an oxygen-containing gas or as an oxidation reactor to oxidize compounds in a feed gas stream by oxygen permeated through the mixed metal oxide ceramic material of the membrane modules.

  10. Ion transport membrane module and vessel system

    DOE Patents [OSTI]

    Stein, VanEric Edward (Allentown, PA); Carolan, Michael Francis (Allentown, PA); Chen, Christopher M. (Allentown, PA); Armstrong, Phillip Andrew (Orefield, PA); Wahle, Harold W. (North Canton, OH); Ohrn, Theodore R. (Alliance, OH); Kneidel, Kurt E. (Alliance, OH); Rackers, Keith Gerard (Louisville, OH); Blake, James Erik (Uniontown, OH); Nataraj, Shankar (Allentown, PA); Van Doorn, Rene Hendrik Elias (Obersulm-Willsbach, DE); Wilson, Merrill Anderson (West Jordan, UT)

    2012-02-14

    An ion transport membrane system comprising (a) a pressure vessel having an interior, an exterior, an inlet, and an outlet; (b) a plurality of planar ion transport membrane modules disposed in the interior of the pressure vessel and arranged in series, each membrane module comprising mixed metal oxide ceramic material and having an interior region and an exterior region, wherein any inlet and any outlet of the pressure vessel are in flow communication with exterior regions of the membrane modules; and (c) one or more gas manifolds in flow communication with interior regions of the membrane modules and with the exterior of the pressure vessel. The ion transport membrane system may be utilized in a gas separation device to recover oxygen from an oxygen-containing gas or as an oxidation reactor to oxidize compounds in a feed gas stream by oxygen permeated through the mixed metal oxide ceramic material of the membrane modules.

  11. Fluid transport by active elastic membranes

    E-Print Network [OSTI]

    Arthur A. Evans; Eric Lauga

    2013-02-10

    A flexible membrane deforming its shape in time can self-propel in a viscous fluid. Alternatively, if the membrane is anchored, its deformation will lead to fluid transport. Past work in this area focused on situations where the deformation kinematics of the membrane were prescribed. Here we consider models where the deformation of the membrane is not prescribed, but instead the membrane is internally forced. Both the time-varying membrane shape, and the resulting fluid motion, result then from a balance between prescribed internal active stresses, internal passive resistance, and external viscous stresses. We introduce two specific models for such active internal forcing: one where a distribution of active bending moments is prescribed, and one where active inclusions exert normal stresses on the membrane by pumping fluid through it. In each case, we asymptotically calculate the membrane shape and the fluid transport velocities for small forcing amplitudes, and recover our results using scaling analysis.

  12. Transport diffusion of liquid water and methanol through membranes...

    Office of Scientific and Technical Information (OSTI)

    Transport diffusion of liquid water and methanol through membranes Citation Details In-Document Search Title: Transport diffusion of liquid water and methanol through membranes The...

  13. A rational route to probing membrane proteins

    E-Print Network [OSTI]

    Keating, Amy E.

    A recent report describes the design of short peptides that bind specifically to transmembrane regions of integrins, providing an exciting tool for probing the biology of membrane proteins.

  14. Hydrogen Bond Shaping of Membrane Protein Structure

    E-Print Network [OSTI]

    Cao, Zheng

    2013-01-01

    2 1.3. HYDROGEN BOND STRENGTHAND EQUILIBRIUM HYDROGEN / DEUTERIUM FRACTIONATION4 1.4. MEASUING HYDROGEN BOND STRENGTH IN A MEMBRANE PROTEIN

  15. Liners for ion transport membrane systems

    DOE Patents [OSTI]

    Carolan, Michael Francis (Allentown, PA); Miller, Christopher Francis (Macungie, PA)

    2010-08-10

    Ion transport membrane system comprising (a) a pressure vessel comprising an interior, an exterior, an inlet, an inlet conduit, an outlet, and an outlet conduit; (b) a plurality of planar ion transport membrane modules disposed in the interior of the pressure vessel and arranged in series, each membrane module comprising mixed metal oxide ceramic material and having an interior region and an exterior region, wherein the inlet and the outlet of the pressure vessel are in flow communication with exterior regions of the membrane modules; (c) a gas manifold having an interior surface wherein the gas manifold is in flow communication with the interior region of each of the planar ion transport membrane modules and with the exterior of the pressure vessel; and (d) a liner disposed within any of the inlet conduit, the outlet conduit, and the interior surface of the gas manifold.

  16. Deciphering the Mechanism of E. coli tat Protein Transport: Kinetic Substeps and Cargo Properties 

    E-Print Network [OSTI]

    Whitaker, Neal William 1982-

    2012-12-03

    The Escherichia coli twin-arginine translocation (Tat) system transports fully folded and assembled proteins across the inner membrane into the periplasmic space. The E. coli Tat machinery minimally consists of three integral membrane proteins: TatA...

  17. Effective Potential Energy Expression for Membrane Transport

    E-Print Network [OSTI]

    Robert W. Finkel

    2007-02-11

    All living cells transport molecules and ions across membranes, often against concentration gradients. This active transport requires continual energy expenditure and is clearly a nonequilibrium process for which standard equilibrium thermodynamics is not rigorously applicable. Here we derive a nonequilibrium effective potential that evaluates the per particle transport energy invested by the membrane. A novel method is used whereby a Hamiltonian function is constructed using particle concentrations as generalized coordinates. The associated generalized momenta are simply related to the individual particle energy from which we identify the effective potential. Examples are given and the formalism is compared with the equilibrium Gibb's free energy.

  18. Crystallizing Membrane Proteins in Lipidic Mesophases. A Host...

    Office of Scientific and Technical Information (OSTI)

    Crystallizing Membrane Proteins in Lipidic Mesophases. A Host Lipid Screen Citation Details In-Document Search Title: Crystallizing Membrane Proteins in Lipidic Mesophases. A Host...

  19. Composition variation and underdamped mechanics near membrane proteins and coats

    E-Print Network [OSTI]

    S. Alex Rautu; George Rowlands; Matthew S. Turner

    2015-02-14

    We study the effect of membrane proteins on the shape, composition and thermodynamic stability of the surrounding membrane. When the coupling between membrane composition and curvature is strong enough the nearby composition and shape both undergo a transition from over-damped to under-damped spatial variation, well before the membrane becomes unstable in the bulk. This transition is associated with a change in the sign of the thermodynamic energy and hence has the unusual features that it can favour the early stages of coat assembly necessary for vesiculation (budding), while suppressing the activity of mechanosensitive membrane channels and transporters. Our results also suggest an approach to obtain physical parameters that are otherwise difficult to measure.

  20. Investigating cotranslational integration of a multi-spanning membrane protein into the endoplasmic reticulum membrane 

    E-Print Network [OSTI]

    Jongsma, Candice Gene

    2009-05-15

    Most membrane proteins in eukaryotic cells are co-translationally integrated into the endoplasmic reticulum (ER) membrane at aqueous pores termed translocons. During multi-spanning membrane protein (MSMP) integration, the nascent polypeptide...

  1. Interaction of membrane-spanning proteins with peripheral and lipid-anchored membrane proteins: perspectives from protein lipid interactions (Review)

    E-Print Network [OSTI]

    Kleinschmidt, Jörg H.

    Interaction of membrane-spanning proteins with peripheral and lipid-anchored membrane proteins: perspectives from protein ± lipid interactions (Review) D. Marsh{*, L. I. HorvaÂth{, M. J. Swamy}, S ± protein interactions in double-reconstituted systems involving both integral and peripheral or lipid

  2. Directional interactions and cooperativity between mechanosensitive membrane proteins

    E-Print Network [OSTI]

    Christoph A. Haselwandter; Rob Phillips

    2013-05-24

    While modern structural biology has provided us with a rich and diverse picture of membrane proteins, the biological function of membrane proteins is often influenced by the mechanical properties of the surrounding lipid bilayer. Here we explore the relation between the shape of membrane proteins and the cooperative function of membrane proteins induced by membrane-mediated elastic interactions. For the experimental model system of mechanosensitive ion channels we find that the sign and strength of elastic interactions depend on the protein shape, yielding distinct cooperative gating curves for distinct protein orientations. Our approach predicts how directional elastic interactions affect the molecular structure, organization, and biological function of proteins in crowded membranes.

  3. Protein Flips Lipids Across Membranes

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration wouldMass mapSpeedingProgramExemptionsProtein Dynamics Hit the Big Screen ProteinProteinProtein

  4. Protein Flips Lipids Across Membranes

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration wouldMass mapSpeedingProgramExemptionsProtein Dynamics Hit the Big Screen ProteinProtein Flips

  5. Protein Flips Lipids Across Membranes

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration wouldMass mapSpeedingProgramExemptionsProtein Dynamics Hit the Big Screen ProteinProtein

  6. Cellular mechanisms of membrane protein folding William R Skach

    E-Print Network [OSTI]

    Cai, Long

    Cellular mechanisms of membrane protein folding William R Skach The membrane protein­folding. This Perspective will focus on emerging evidence that the RTC functions as a protein-folding machine that restricts. The process of polytopic (multispanning) membrane protein folding can be viewed as a series of sequential

  7. Evaluating cell-free expression of human integral membrane proteins for structural studies by NMR spectroscopy

    E-Print Network [OSTI]

    Chiu, Ellis Jeremy Chua

    2010-01-01

    Genome-wide analysis of integral membrane proteins fromLarge Scale Preparation of Integral Membrane Proteins forLarge Scale Production of Integral Membrane Protein." FEBS

  8. Protein Flips Lipids Across Membranes

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration wouldMass mapSpeedingProgramExemptionsProtein Dynamics Hit the Big Screen Protein

  9. Pearling instability of membrane tubes driven by curved proteins and actin polymerization

    E-Print Network [OSTI]

    Urška Jeler?i?; Nir S. Gov

    2014-09-26

    Membrane deformation inside living cells is crucial for the proper shaping of various intracellular organelles and is necessary during the fission/fusion processes that allow membrane recycling and transport (e.g. endocytosis). Proteins that induce membrane curvature play a key role in such processes, mostly by adsorbing to the membrane and forming a scaffold that deforms the membrane according to the curvature of the proteins. In this paper we explore the possibility of membrane tube destabilisation through a pearling mechanism enabled by the combined effects of the adsorbed curved proteins and the actin polymerization they may recruit. The pearling instability can furthermore serve as the initiation for fission of the tube into vesicles. We find that adsorbed proteins are more likely to stabilise the tubes, while the actin polymerization can provide the additional constrictive force needed for the robust instability. We discuss the relevance of the theoretical results to in-vivo and in-vitro experiments.

  10. Artificial oxygen transport protein

    DOE Patents [OSTI]

    Dutton, P. Leslie

    2014-09-30

    This invention provides heme-containing peptides capable of binding molecular oxygen at room temperature. These compounds may be useful in the absorption of molecular oxygen from molecular oxygen-containing atmospheres. Also included in the invention are methods for treating an oxygen transport deficiency in a mammal.

  11. Microfluidic Generation of Lipidic Mesophases for Membrane Protein Crystallization

    E-Print Network [OSTI]

    Kenis, Paul J. A.

    Microfluidic Generation of Lipidic Mesophases for Membrane Protein Crystallization Sarah L. Perry Mathews AVenue, Urbana, Illinois 61801 ReceiVed March 11, 2009 ABSTRACT: We report on a microfluidic conditions of membrane proteins from a membrane-like phase in sub-20 nL volumes. This integrated microfluidic

  12. Structure and Assembly of -Barrel Membrane Proteins*S

    E-Print Network [OSTI]

    Kleinschmidt, Jörg H.

    Structure and Assembly of -Barrel Membrane Proteins*S Published, JBC Papers in Press, June 29, 2001, Virginia 22908-0736 Integral membrane proteins fall into two major structural classes; they consist apolar en- vironment of the lipid bilayer. No other structural motif has yet been confirmed for membrane

  13. Fabrication of catalyzed ion transport membrane systems

    DOE Patents [OSTI]

    Carolan, Michael Francis; Kibby, Charles Leonard

    2013-06-04

    Process for fabricating a catalyzed ion transport membrane (ITM). In one embodiment, an uncatalyzed ITM is (a) contacted with a non-reducing gaseous stream while heating to a temperature and for a time period sufficient to provide an ITM possessing anion mobility; (b) contacted with a reducing gaseous stream for a time period sufficient to provide an ITM having anion mobility and essentially constant oxygen stoichiometry; (c) cooled while contacting the ITM with the reducing gaseous stream to provide an ITM having essentially constant oxygen stoichiometry and no anion mobility; and (d) treated by applying catalyst to at least one of (1) a porous mixed conducting multicomponent metallic oxide (MCMO) layer contiguous with a first side of a dense layer of MCMO and (2) a second side of the dense MCMO layer. In another embodiment, these steps are carried out in the alternative order of (a), (d), (b), and (c).

  14. MICROFLUIDIC DEVICE FOR SUPER-FAST EVALUATION OF MEMBRANE PROTEIN

    E-Print Network [OSTI]

    Pace, Norman

    MICROFLUIDIC DEVICE FOR SUPER-FAST EVALUATION OF MEMBRANE PROTEIN CRYSTALLIZATION Hsin-Jui Wu1- throughput membraneless microfluidic device to fast produce the reconstitution of membrane protein in microfluidic channel can be completed in seconds to form protein/lipid particles under multiple conditions

  15. Transport Phenomena in Polymer Electrolyte Membranes II. Binary Friction Membrane Model

    E-Print Network [OSTI]

    Struchtrup, Henning

    Transport Phenomena in Polymer Electrolyte Membranes II. Binary Friction Membrane Model J. Fimrite by the need for improved and more gen- eral models to represent transport phenomena within polymer elec dynamic models required for fundamental simulation of in situ processes that are difficult to ob- serve

  16. Membranes for nanometer-scale mass fast transport

    DOE Patents [OSTI]

    Bakajin, Olgica (San Leandro, CA); Holt, Jason (Berkeley, CA); Noy, Aleksandr (Belmont, CA); Park, Hyung Gyu (Oakland, CA)

    2011-10-18

    Nanoporous membranes comprising single walled, double walled, and multiwalled carbon nanotubes embedded in a matrix material were fabricated for fluid mechanics and mass transfer studies on the nanometer scale and commercial applications. Average pore size can be 2 nm to 20 nm, or seven nm or less, or two nanometers or less. The membrane can be free of large voids spanning the membrane such that transport of material such as gas or liquid occurs exclusively through the tubes. Fast fluid, vapor, and liquid transport are observed. Versatile micromachining methods can be used for membrane fabrication. A single chip can comprise multiple membranes. These membranes are a robust platform for the study of confined molecular transport, with applications in liquid and gas separations and chemical sensing including desalination, dialysis, and fabric formation.

  17. Feed gas contaminant removal in ion transport membrane systems

    DOE Patents [OSTI]

    Underwood, Richard Paul (Allentown, PA); Makitka, III, Alexander (Hatfield, PA); Carolan, Michael Francis (Allentown, PA)

    2012-04-03

    An oxygen ion transport membrane process wherein a heated oxygen-containing gas having one or more contaminants is contacted with a reactive solid material to remove the one or more contaminants. The reactive solid material is provided as a deposit on a support. The one or more contaminant compounds in the heated oxygen-containing gas react with the reactive solid material. The contaminant-depleted oxygen-containing gas is contacted with a membrane, and oxygen is transported through the membrane to provide transported oxygen.

  18. Interfacial Water-Transport Effects in Proton-Exchange Membranes

    SciTech Connect (OSTI)

    Kienitz, Brian; Yamada, Haruhiko; Nonoyama, Nobuaki; Weber, Adam

    2009-11-19

    It is well known that the proton-exchange membrane is perhaps the most critical component of a polymer-electrolyte fuel cell. Typical membranes, such as Nafion(R), require hydration to conduct efficiently and are instrumental in cell water management. Recently, evidence has been shown that these membranes might have different interfacial morphology and transport properties than in the bulk. In this paper, experimental data combined with theoretical simulations will be presented that explore the existence and impact of interfacial resistance on water transport for Nafion(R) 21x membranes. A mass-transfer coefficient for the interfacial resistance is calculated from experimental data using different permeation cells. This coefficient is shown to depend exponentially on relative humidity or water activity. The interfacial resistance does not seem to exist for liquid/membrane or membrane/membrane interfaces. The effect of the interfacial resistance is to flatten the water-content profiles within the membrane during operation. Under typical operating conditions, the resistance is on par with the water-transport resistance of the bulk membrane. Thus, the interfacial resistance can be dominant especially in thin, dry membranes and can affect overall fuel-cell performance.

  19. Ultraviolet resonance Raman spectroscopy of the integral membrane protein OmpA : elucidating structure and tryptophan microenvironment of folded and unfolded states

    E-Print Network [OSTI]

    Neary, Tiffany Jonean

    2008-01-01

    Intermediates in Membrane Protein Folding,” Biochemistry (Intermediates in Membrane Protein Folding,” Biochemistry (Engelman. “ Membrane-Protein Folding and Oligomerization -

  20. Simple Model of Membrane Proteins Including Solvent

    E-Print Network [OSTI]

    D. L. Pagan; A. Shiryayev; T. P. Connor; J. D. Gunton

    2006-03-04

    We report a numerical simulation for the phase diagram of a simple two dimensional model, similar to one proposed by Noro and Frenkel [J. Chem. Phys. \\textbf{114}, 2477 (2001)] for membrane proteins, but one that includes the role of the solvent. We first use Gibbs ensemble Monte Caro simulations to determine the phase behavior of particles interacting via a square-well potential in two dimensions for various values of the interaction range. A phenomenological model for the solute-solvent interactions is then studied to understand how the fluid-fluid coexistence curve is modified by solute-solvent interactions. It is shown that such a model can yield systems with liquid-liquid phase separation curves that have both upper and lower critical points, as well as closed loop phase diagrams, as is the case with the corresponding three dimensional model.

  1. Outer membrane protein A of E. coli folds into detergent micelles, but not in the

    E-Print Network [OSTI]

    Kleinschmidt, Jörg H.

    Outer membrane protein A of E. coli folds into detergent micelles, but not in the presence-barrel membrane proteins, folding of OmpA was studied as a function of the hydrophobic chain length, the chemical; membrane protein folding; outer membrane protein A; porin; protein­detergent interaction; protein

  2. 2007 Annual progress report synopsis of the Center for Structures of Membrane Proteins

    E-Print Network [OSTI]

    2009-01-01

    expression of human membrane proteins in E. coli using theand archeal membrane proteins in E. coli. Drs. Choe, MinorStructures of Membrane Proteins (CSMP), UCSF, MC2240, S412C,

  3. Continuum Electromechanical Modeling of Protein-Membrane Interaction

    E-Print Network [OSTI]

    Y. C. Zhou; Benzhuo Lu; Alemayehu A. Gorfe

    2010-08-17

    A continuum electromechanical model is proposed to describe the membrane curvature induced by electrostatic interactions in a solvated protein-membrane system. The model couples the macroscopic strain energy of membrane and the electrostatic solvation energy of the system, and equilibrium membrane deformation is obtained by minimizing the electro-elastic energy functional with respect to the dielectric interface. The model is illustrated with the systems with increasing geometry complexity and captures the sensitivity of membrane curvature to the permanent and mobile charge distributions.

  4. Continuum Electromechanical Modeling of Protein-Membrane Interaction

    E-Print Network [OSTI]

    Zhou, Y C; Gorfe, Alemayehu A

    2010-01-01

    A continuum electromechanical model is proposed to describe the membrane curvature induced by electrostatic interactions in a solvated protein-membrane system. The model couples the macroscopic strain energy of membrane and the electrostatic solvation energy of the system, and equilibrium membrane deformation is obtained by minimizing the electro-elastic energy functional with respect to the dielectric interface. The model is illustrated with the systems with increasing geometry complexity and captures the sensitivity of membrane curvature to the permanent and mobile charge distributions.

  5. IFITM Proteins Restrict Viral Membrane Hemifusion

    E-Print Network [OSTI]

    2013-01-01

    M (2008) HIV-1 accessory proteins–ensuring viral survival intransmembrane genes and proteins. J Interferon Cytokine Reset al. (2009) The IFITM proteins mediate cellular resistance

  6. Lateral mobility of proteins in liquid membranes revisited

    E-Print Network [OSTI]

    Urbach, Wladimir

    Lateral mobility of proteins in liquid membranes revisited Y. Gambin* , R. Lopez-Esparza*, M, December 21, 2005 (received for review December 10, 2005) The biological function of transmembrane proteins a weak, logarithmic dependence of the diffusion coefficient D with the radius R of the protein. Despite

  7. Effective Energy Function for Proteins in Lipid Membranes Themis Lazaridis*

    E-Print Network [OSTI]

    Lazaridis, Themis

    , City College of the City University of New York, New York, New York ABSTRACT A simple extensionEffective Energy Function for Proteins in Lipid Membranes Themis Lazaridis* Department of Chemistry of the EEF1 energy function to heterogeneous membrane-aque- ous media is proposed. The extension consists

  8. Inner nuclear membrane proteins: targeting and influence on genome organization 

    E-Print Network [OSTI]

    Zuleger, Nikolaj

    2012-06-22

    The nuclear envelope is a complex double membrane system that separates the activities of the nuclear and cytoplasmic compartments. A recent explosion in the number of proteins associated with this subnuclear organelle together ...

  9. Application of nuclear magnetic resonance spectroscopy to the structure determination of the integral membrane proteins of the Mer operon

    E-Print Network [OSTI]

    Howell, Stanley Casimir

    2007-01-01

    solid-state NMR spectra of integral membrane proteinstruncated versions of the integral membrane protein Vpu frompreparation for helical integral membrane proteins. J Struct

  10. IFITM Proteins Restrict Viral Membrane Hemifusion

    E-Print Network [OSTI]

    2013-01-01

    an intermediate of fusion, referred to as a cold arrestedcold arrested state (CAS), PLOS Pathogens | www.plospathogens.org January 2013 | Volume 9 | Issue 1 | e1003124 Restriction of Viral Membrane Fusion

  11. Interaction between a plasma membrane-localized ankyrin-repeat protein ITN1 and a nuclear protein RTV1

    SciTech Connect (OSTI)

    Sakamoto, Hikaru; Sakata, Keiko; Kusumi, Kensuke; Kojima, Mikiko; Sakakibara, Hitoshi; Iba, Koh

    2012-06-29

    Highlights: Black-Right-Pointing-Pointer ITN1, a plasma membrane ankyrin protein, interacts with a nuclear DNA-binding protein RTV1. Black-Right-Pointing-Pointer The nuclear transport of RTV1 is partially inhibited by interaction with ITN1. Black-Right-Pointing-Pointer RTV1 can promote the nuclear localization of ITN1. Black-Right-Pointing-Pointer Both overexpression of RTV1 and the lack of ITN1 increase salicylic acids sensitivity in plants. -- Abstract: The increased tolerance to NaCl 1 (ITN1) protein is a plasma membrane (PM)-localized protein involved in responses to NaCl stress in Arabidopsis. The predicted structure of ITN1 is composed of multiple transmembrane regions and an ankyrin-repeat domain that is known to mediate protein-protein interactions. To elucidate the molecular functions of ITN1, we searched for interacting partners using a yeast two-hybrid assay, and a nuclear-localized DNA-binding protein, RTV1, was identified as a candidate. Bimolecular fluorescence complementation analysis revealed that RTV1 interacted with ITN1 at the PM and nuclei in vivo. RTV1 tagged with red fluorescent protein localized to nuclei and ITN1 tagged with green fluorescent protein localized to PM; however, both proteins localized to both nuclei and the PM when co-expressed. These findings suggest that RTV1 and ITN1 regulate the subcellular localization of each other.

  12. Feed gas contaminant control in ion transport membrane systems

    DOE Patents [OSTI]

    Carolan, Michael Francis (Allentown, PA); Minford, Eric (Laurys Station, PA); Waldron, William Emil (Whitehall, PA)

    2009-07-07

    Ion transport membrane oxidation system comprising an enclosure having an interior and an interior surface, inlet piping having an internal surface and adapted to introduce a heated feed gas into the interior of the enclosure, and outlet piping adapted to withdraw a product gas from the interior of the enclosure; one or more planar ion transport membrane modules disposed in the interior of the enclosure, each membrane module comprising mixed metal oxide material; and a preheater adapted to heat a feed gas to provide the heated feed gas to the inlet piping, wherein the preheater comprises an interior surface. Any of the interior surfaces of the enclosure, the inlet piping, and the preheater may be lined with a copper-containing metal lining. Alternatively, any of the interior surfaces of the inlet piping and the preheater may be lined with a copper-containing metal lining and the enclosure may comprise copper.

  13. ADVANCED HYDROGEN TRANSPORT MEMBRANES FOR VISION 21 FOSSIL FUEL PLANTS

    SciTech Connect (OSTI)

    Shane E. Roark; Tony F. Sammells; Richard A. Mackay; Adam E. Calihman; Lyrik Y. Pitzman; Tom F. Barton; Sara L. Rolfe; Richard N. Kleiner; James E. Stephan; Mike J. Holmes; Aaron L. Wagner

    2001-07-30

    Eltron Research Inc., and team members, are developing an environmentally benign, inexpensive, and efficient method for separating hydrogen from gas mixtures produced during industrial processes, such as coal gasification. This project was motivated by the National Energy Technology Laboratory (NETL) Vision 21 initiative which seeks to economically eliminate environmental concerns associated with the use of fossil fuels. This objective is being pursued using dense membranes based in part on Eltron-patented ceramic materials with a demonstrated ability for proton and electron conduction. The technical goals are being addressed by modifying single-phase and composite membrane composition and microstructure to maximize proton and electron conductivity without loss of material stability. Ultimately, these materials must enable hydrogen separation at practical rates under ambient and high-pressure conditions, without deactivation in the presence of feedstream components such as carbon dioxide, water, and sulfur. During this quarter, ceramic, cermet (ceramic/metal), and thin film membranes were prepared, characterized, and evaluated for H{sub 2} transport. For selected ceramic membrane compositions an optimum range for transition metal doping was identified, and it was determined that highest proton conductivity occurred for two-phase ceramic materials. Furthermore, a relationship between transition metal dopant atomic number and conductivity was observed. Ambipolar conductivities of {approx}6 x 10{sup -3} S/cm were achieved for these materials, and {approx} 1-mm thick membranes generated H{sub 2} transport rates as high as 0.3 mL/min/cm{sup 2}. Cermet membranes during this quarter were found to have a maximum conductivity of 3 x 10{sup -3} S/cm, which occurred at a metal phase contact of 36 vol.%. Homogeneous dense thin films were successfully prepared by tape casting and spin coating; however, there remains an unacceptably high difference in shrinkage rates between the film and support, which led to membrane instability. Further improvements in high pressure membrane seals also were achieved during this quarter, and a maximum pressure of 100 psig was attained. CoorsTek optimized many of the processing variables relevant to manufacturing scale production of ceramic H{sub 2} transport membranes, and SCI used their expertise to deposit a range of catalysts compositions onto ceramic membrane surfaces. Finally, MTI compiled relevant information regarding Vision 21 fossil fuel plant operation parameters, which will be used as a starting point for assessing the economics of incorporating a H{sub 2} separation unit.

  14. Continuum electromechanical modeling of protein-membrane interactions Y. C. Zhou*

    E-Print Network [OSTI]

    Lu, Benzhuo

    Continuum electromechanical modeling of protein-membrane interactions Y. C. Zhou* Department; published 28 October 2010 A continuum electromechanical model is proposed to describe the membrane curvature

  15. PHYSICAL REVIEW E 84, 031924 (2011) Fluid transport by active elastic membranes

    E-Print Network [OSTI]

    Lauga, Eric

    2011-01-01

    PHYSICAL REVIEW E 84, 031924 (2011) Fluid transport by active elastic membranes Arthur A. Evans1, if the membrane is anchored, its deformation will lead to fluid transport. Past work in this area focused. In each case, we asymptotically calculate the membrane shape and the fluid transport velocities for small

  16. ADVANCED HYDROGEN TRANSPORT MEMBRANES FOR VISION 21 FOSSIL FUEL PLANTS

    SciTech Connect (OSTI)

    Shane E. Roark; Tony F. Sammells; Richard A. Mackay; Lyrik Y. Pitzman; Alexandra Z. LaGuardia; Tom F. Barton; Sara L. Rolfe; Richard N. Kleiner; James E. Stephan; Mike J. Holmes; Aaron L. Wagner

    2001-10-30

    Eltron Research Inc., and team members CoorsTek, McDermott Technology, Inc., Sued Chemie, Argonne National Laboratory and Oak Ridge National Laboratory are developing an environmentally benign, inexpensive, and efficient method for separating hydrogen from gas mixtures produced during industrial processes, such as coal gasification. This project was motivated by the National Energy Technology Laboratory (NETL) Vision 21 initiative which seeks to economically eliminate environmental concerns associated with the use of fossil fuels. This objective is being pursued using dense membranes based in part on Eltron-patented ceramic materials with a demonstrated ability for proton and electron conduction. The technical goals are being addressed by modifying single-phase and composite membrane composition and microstructure to maximize proton and electron conductivity without loss of material stability. Ultimately, these materials must enable hydrogen separation at practical rates under ambient and high-pressure conditions, without deactivation in the presence of feedstream components such as carbon dioxide, water, and sulfur. During this quarter, mixed proton/electron conductivity and hydrogen transport was measured as a function of metal phase content for a range of ceramic/metal (cermet) compositions. It was found that optimum performance occurred at 44 wt.% metal content for all compositions tested. Although each cermet appeared to have a continuous metal phase, it is believed that hydrogen transport increased with increasing metal content partially due to beneficial surface catalyst characteristics resulting from the metal phase. Beyond 44 wt.% there was a reduction in hydrogen transport most likely due to dilution of the proton conducting ceramic phase. Hydrogen separation rates for 1-mm thick cermet membranes were in excess of 0.1 mL/min/cm{sup 2}, which corresponded to ambipolar conductivities between 1 x 10{sup -3} and 8 x 10{sup -3} S/cm. Similar results were obtained for multiphase ceramic membranes comprised of a proton-conducting perovskite and electron conducting metal oxide. These multi-phase ceramic membranes showed only a slight improvement in hydrogen transport upon addition of a metal phase. The highest hydrogen separation rates observed this quarter were for a cermet membrane containing a hydrogen transport metal. A 1-mm thick membrane of this material achieved a hydrogen separation rate of 0.3 mL/min/cm{sup 2} at only 700 C, which increased to 0.6 mL/min/cm{sup 2} at 950 C.

  17. Hydrogen bond dynamics in membrane protein function Ana-Nicoleta Bondar a,

    E-Print Network [OSTI]

    White, Stephen

    Review Hydrogen bond dynamics in membrane protein function Ana-Nicoleta Bondar a, , Stephen H 30 November 2011 Available online 8 December 2011 Keywords: Membrane protein structure Hydrogen bond Membrane protein dynamics Lipid­protein interactions Changes in inter-helical hydrogen bonding

  18. Protein separations using porous silicon membranes 

    E-Print Network [OSTI]

    Pass, Shannon Marie

    1992-01-01

    ) 61 IX LIST OF TABLES 1. The L9 Orthogonal Array 34 2. Experimental Factors and Levels . 3. Results of Silicon Etching Trials . 35 40 4. Results of Silicon Membrane Separation Experiments 44 5. Results of Single Solute Experiments Using... charge or as the absence of an electron in the crystal structure of silicon. The properties of boron doped siTicon are exploited experimentally by setting up an etch cell in which one surface of the silicon serves as the anode and by using...

  19. Ultraviolet resonance Raman spectroscopy of the integral membrane protein OmpA : elucidating structure and tryptophan microenvironment of folded and unfolded states

    E-Print Network [OSTI]

    Neary, Tiffany Jonean

    2008-01-01

    Elastic Coupling of Integral Membrane Protein Stability toThermodynamic Stability of Integral Membrane Proteins,” J.Raman Spectroscopy of the Integral Membrane Protein OmpA:

  20. Prediction of Membrane Proteins in Post-Genomic Era

    E-Print Network [OSTI]

    Kihara, Daisuke

    by the report that the human genome sequencing project has been completed [1,2]. Beyond the human genome, a surge of world-wide genome projects in the last decade have been producing complete genome sequences1 Prediction of Membrane Proteins in Post-Genomic Era Daisuke Kihara1* & Minoru Kanehisa2 1) Donald

  1. Docosahexaenoic acid differentially modulates plasma membrane targeting and subcellular localization of lipidated proteins in colonocytes 

    E-Print Network [OSTI]

    Seo, Jeongmin

    2006-04-12

    Correct localization of lipidated cytosolic proteins to the plasma membrane (PM) is mediated by interactions between lipid anchors of proteins and cell membranes. Previously, dietary fish oil and its major n-3 polyunsaturated fatty acid (PUFA...

  2. Ultraviolet resonance Raman and fluorescence studies of folded and unfolded conformations of the membrane protein OmpA

    E-Print Network [OSTI]

    Sanchez, Katheryn Marie

    2010-01-01

    Thermodynamics of Membrane Protein Folding: Lessons from theA Model for Membrane Protein Folding”, H. S. Shafaat, K. M.goals of membrane protein folding studies is to ascertain

  3. ADVANCED HYDROGEN TRANSPORT MEMBRANES FOR VISION 21 FOSSIL FUEL PLANTS

    SciTech Connect (OSTI)

    Shane E. Roark; Anthony F. Sammells; Richard A. Mackay; Lyrik Y. Pitzman; Thomas A. Zirbel; Thomas F. Barton; Sara L. Rolfe; U. (Balu) Balachandran; Richard N. Kleiner; James E. Stephan; Frank E. Anderson; George Farthing; Dan Rowley; Tim R. Armstrong; M.K. Ferber; Aaron L. Wagner; Jon P. Wagner

    2002-07-30

    Eltron Research Inc. and their team members are developing an environmentally benign, inexpensive, and efficient method for separating hydrogen from gas mixtures produced during industrial processes, such as coal gasification. This project was motivated by the National Energy Technology Laboratory (NETL) Vision 21 initiative which seeks to economically eliminate environmental concerns associated with the use of fossil fuels. This objective is being pursued using dense membranes based in part on Eltron-patented ceramic materials with a demonstrated ability for proton and electron conduction. The technical goals are being addressed by modifying single-phase and composite membrane composition and microstructure to maximize proton and electron conductivity without loss of material stability. Ultimately, these materials must enable hydrogen separation at practical rates under ambient and high-pressure conditions, without deactivation in the presence of feedstream components such as carbon dioxide, water, and sulfur. During this quarter, new cermet compositions were tested that demonstrated similar performance to previous materials. A 0.5-mm thick membrane achieved at H{sub 2} transport rate of 0.2 mL/min/cm{sup 2} at 950 C, which corresponded to an ambipolar conductivity of 3 x 10{sup -3} S/cm. Although these results were equivalent to those for other cermet compositions, this new composition might be useful if it demonstrates improved chemical or mechanical stability. Ceramic/ceramic composite membranes also were fabricated and tested; however, some reaction did occur between the proton- and electron-conducting phases, which likely compromised conductivity. This sample only achieved a H{sub 2} transport rate of {approx} 0.006 mL/min/cm{sup 2} and an ambipolar conductivity of {approx}4 x 10{sup -4} S/cm. Chemical stability tests were continued, and candidate ceramic membranes were found to react slightly with carbon monoxide under extreme testing conditions. A cermet compositions did not show any reaction with carbon monoxide, but a thick layer of carbon formed on the membrane surface. The most significant technical accomplishment this quarter was a new high-pressure seal composition. This material maintained a pressure differential across the membrane of {approx} 280 psi at 800 C, and is still in operation.

  4. Similar Energetic Contributions of Packing in the Core of Membrane and Water-Soluble Proteins

    SciTech Connect (OSTI)

    Joh, Nathan H.; Oberai, Amit; Yang, Duan; Whitelegge, Julian P.; Bowie, James U.; (UCLA)

    2009-09-15

    A major driving force for water-soluble protein folding is the hydrophobic effect, but membrane proteins cannot make use of this stabilizing contribution in the apolar core of the bilayer. It has been proposed that membrane proteins compensate by packing more efficiently. We therefore investigated packing contributions experimentally by observing the energetic and structural consequences of cavity creating mutations in the core of a membrane protein. We observed little difference in the packing energetics of water and membrane soluble proteins. Our results imply that other mechanisms are employed to stabilize the structure of membrane proteins.

  5. FINAL REPORT:Observation and Simulations of Transport of Molecules and Ions Across Model Membranes

    SciTech Connect (OSTI)

    MURAD, SOHAIL; JAMESON, CYNTHIA J

    2013-10-22

    During the this new grant we developed a robust methodology for investigating a wide range of properties of phospho-lipid bilayers. The approach developed is unique because despite using periodic boundary conditions, we can simulate an entire experiment or process in detail. For example, we can follow the entire permeation process in a lipid-membrane. This includes transport from the bulk aqueous phase to the lipid surface; permeation into the lipid; transport inside the lipid; and transport out of the lipid to the bulk aqueous phase again. We studied the transport of small gases in both the lipid itself and in model protein channels. In addition, we have examined the transport of nanocrystals through the lipid membrane, with the main goal of understanding the mechanical behavior of lipids under stress including water and ion leakage and lipid flip flop. Finally we have also examined in detail the deformation of lipids when under the influence of external fields, both mechanical and electrostatic (currently in progress). The important observations and conclusions from our studies are described in the main text of the report

  6. Proton Transport and the Water Environment in Nafion Fuel Cell Membranes and AOT Reverse Micelles

    E-Print Network [OSTI]

    Fayer, Michael D.

    Proton Transport and the Water Environment in Nafion Fuel Cell Membranes and AOT Reverse Micelles D channels of Nafion fuel cell membranes at various hydration levels are compared to water in a series by its use as a proton conducting membrane in fuel cells. Nafion membranes in fuel cells allow protons

  7. Energy use by biological protein transport pathways

    E-Print Network [OSTI]

    Economou, Tassos

    Energy use by biological protein transport pathways Nathan N. Alder1 and Steven M. Theg2 1 of metabolic energy, using the free energy of ATP and GTP hydrolysis and/or a transmembrane protonmotive force provided insights into the mechanisms of energy transduction, force generation and energy use by different

  8. ADVANCED HYDROGEN TRANSPORT MEMBRANES FOR VISION 21 FOSSIL FUEL PLANTS

    SciTech Connect (OSTI)

    Shane E. Roark; Anthony F. Sammells; Richard Mackay; Scott R. Morrison; Sara L. Rolfe; U. Balachandran; Richard N. Kleiner; James E. Stephen; Frank E. Anderson; Shandra Ratnasamy; Jon P. Wagner; Clive Brereton

    2004-01-30

    The objective of this project is to develop an environmentally benign, inexpensive, and efficient method for separating hydrogen from gas mixtures produced during industrial processes, such as coal gasification. Currently, this project is focusing on four basic categories of dense membranes: (1) mixed conducting ceramic/ceramic composites, (2) mixed conducting ceramic/metal (cermet) composites, (3) cermets with hydrogen permeable metals, and (4) layered composites with hydrogen permeable alloys. The primary technical challenge in achieving the goals of this project will be to optimize membrane composition to enable practical hydrogen separation rates and chemical stability. Other key aspects of this developing technology include catalysis, ceramic processing methods, and separation unit design operating under high pressure. To achieve these technical goals, Eltron Research Inc. has organized a consortium consisting of CoorsTek, Sued Chemie, Inc. (SCI), Argonne National Laboratory (ANL), and NORAM. Hydrogen permeation rates in excess of 50 mL {center_dot} min{sup -1} {center_dot} cm{sup 2} at {approx}440 C were routinely achieved under less than optimal experimental conditions using a range of membrane compositions. Factors that limit the maximum permeation attainable were determined to be mass transport resistance of H{sub 2} to and from the membrane surface, as well as surface contamination. Mass transport resistance was partially overcome by increasing the feed and sweep gas flow rates to greater than five liters per minute. Under these experimental conditions, H2 permeation rates in excess of 350 mL {center_dot} min{sup -1} {center_dot} cm{sup 2} at {approx}440 C were attained. These results are presented in this report, in addition to progress with cermets, thin film fabrication, catalyst development, and H{sub 2} separation unit scale up.

  9. Endocytic proteins drive vesicle growth via instability in high membrane tension environment

    E-Print Network [OSTI]

    Nikhil Walani; Jennifer Torres; Ashutosh Agrawal

    2015-02-14

    Clathrin-mediated endocytosis (CME) is a key pathway for transporting cargo into cells via membrane vesicles. It plays an integral role in nutrient import, signal transduction, neurotransmission and cellular entry of pathogens and drug-carrying nanoparticles. As CME entails substantial local remodeling of the plasma membrane, the presence of membrane tension offers resistance to bending and hence, vesicle formation. Experiments show that in such high tension conditions, actin dynamics is required to carry out CME successfully. In this study, we build upon these pioneering experimental studies to provide fundamental mechanistic insights into the roles of two key endocytic proteins, namely, actin and BAR proteins in driving vesicle formation in high membrane tension environment. Our study reveals a new actin force induced `snap-through instability' that triggers a rapid shape transition from a shallow invagination to a highly invaginated tubular structure. We show that the association of BAR proteins stabilizes vesicles and induces a milder instability. In addition, we present a new counterintuitive role of BAR depolymerization in regulating the shape evolution of vesicles. We show that the dissociation of BAR proteins, supported by actin-BAR synergy, leads to considerable elongation and squeezing of vesicles. Going beyond the membrane geometry, we put forth a new stress-based perspective for the onset of vesicle scission and predict the shapes and composition of detached vesicles. We present the snap-through transition and the high in-plane stress as possible explanations for the intriguing direct transformation of broad and shallow invaginations into detached vesicles in BAR mutant yeast cells.

  10. Molecular Structure and Transport Dynamics in Perfluoro Sulfonyl Imide Membranes

    SciTech Connect (OSTI)

    Idupulapati, Nagesh B.; Devanathan, Ramaswami; Dupuis, Michel

    2011-05-25

    We report a detailed and comprehensive analysis of the nanostructure, transport dynamics of water and hydronium and water percolation in hydrated perfluoro sulfonyl imides (PFSI), a polymer considered for proton transport in PEM fuel cells, using classical molecular dynamics simulations. The dynamical changes are related to the changes in the membrane nanostructure. Water network percolation threshold, the level at which a consistent spanning water network starts to develop in the membrane, lies between hydration level (?) 6 and 7. The higher acidity of the sulfonyl imide acid group of PFSI compared to Nafion reported in our earlier ab initio study, translates into more free hydronium ions at low hydration levels. Nevertheless, the calculated diffusion coefficients of the H3O+ ions and H2O molecules as a function the hydration level were observed to be almost the same as that of Nafion, indicating similar conductivity and consistent with the experimental observations. This research was performed in part using the Molecular Science Computing Facility in the William R. Wiley Environmental Molecular Sciences Laboratory, a U.S. Department of Energy (DOE) national scientific user facility located at the Pacific Northwest National Laboratory (PNNL). This work was supported by the US Department of Energy Basic Energy Sciences' Chemical Sciences, Geosciences & Biosciences Division. Pacific Northwest National Laboratory is operated by Battelle for the US Department of Energy.

  11. The Major Outer Membrane Protein of Fusobacterium nucleatum (FomA) Folds and Inserts into Lipid Bilayers

    E-Print Network [OSTI]

    Kleinschmidt, Jörg H.

    The Major Outer Membrane Protein of Fusobacterium nucleatum (FomA) Folds and Inserts into Lipid-5020 Bergen, Norway Membrane protein insertion and folding was studied for the major outer membrane observation of parallel membrane insertion and folding pathways of a b-barrel membrane protein from

  12. ADVANCED HYDROGEN TRANSPORT MEMBRANES FOR VISION 21 FOSSIL FUEL PLANTS

    SciTech Connect (OSTI)

    Shane E. Roark; Tony F. Sammells; Adam Calihman; Andy Girard; Pamela M. Van Calcar; Richard Mackay; Tom Barton; Sara Rolfe

    2001-01-30

    Eltron Research Inc., and team members CoorsTek, McDermott Technology, Inc., Sued Chemie, Argonne National Laboratory, and Oak Ridge National Laboratory are developing an environmentally benign, inexpensive, and efficient method for separating hydrogen from gas mixtures produced during industrial processes, such as coal gasification. This objective is being pursued using dense membranes based in part on Eltron-patented ceramic materials with a demonstrated ability for proton and electron conduction. The technical goals are being addressed by modifying single-phase and composite membrane composition and microstructure to maximize proton and electron conductivity without loss of material stability. Ultimately, these materials must enable hydrogen separation at practical rates under ambient and high-pressure conditions, without deactivation in the presence of feedstream components such as carbon dioxide, water, and sulfur. This project was motivated by the National Energy Technology Laboratory (NETL) Vision 21 initiative which seeks to economically eliminate environmental concerns associated with the use of fossil fuels. The proposed technology addresses the DOE Vision 21 initiative in two ways. First, this process offers a relatively inexpensive solution for pure hydrogen separation that can be easily incorporated into Vision 21 fossil fuel plants. Second, this process could reduce the cost of hydrogen, which is a clean burning fuel under increasing demand as supporting technologies are developed for hydrogen utilization and storage. Additional motivation for this project arises from the potential of this technology for other applications. Membranes testing during this reporting period were greater than 1 mm thick and had the general perovskite composition AB{sub 1-x}B'{sub x}O{sub 3-{delta}}, where 0.05 {<=} x {<=} 0.3. These materials demonstrated hydrogen separation rates between 1 and 2 mL/min/cm{sup 2}, which represents roughly 20% of the target goal for membranes of this thickness. The sintered membranes were greater than 95% dense, but the phase purity decreased with increasing dopant concentration. The quantity of dopant incorporated into the perovskite phase was roughly constant, with excess dopant forming an additional phase. Composite materials with distinct ceramic and metallic phases, and thin film perovskites (100 {micro}m) also were successfully prepared, but have not yet been tested for hydrogen transport. Finally, porous platinum was identified as a excellent catalyst for evaluation of membrane materials, however, lower cost nickel catalyst systems are being developed.

  13. Simple Host-Guest Chemistry To Modulate the Process of Concentration and Crystallization of Membrane Proteins by

    E-Print Network [OSTI]

    Ismagilov, Rustem F.

    of Membrane Proteins by Detergent Capture in a Microfluidic Device Liang Li, Sigrid Nachtergaele, Annela M the crystallization of membrane proteins and the process of concentration of membrane protein samples. Methyl of membrane proteins by sequestering detergent monomers. Reaction Center (RC) from Blastochloris viridis

  14. Folding and Insertion of the Outer Membrane Protein OmpA Is Assisted by the Chaperone Skp and by Lipopolysaccharide*

    E-Print Network [OSTI]

    Kleinschmidt, Jörg H.

    Folding and Insertion of the Outer Membrane Protein OmpA Is Assisted by the Chaperone Skp have studied the folding pathway of a -barrel membrane protein using outer membrane protein A (Omp membrane proteins of bacteria. We investigated how Skp facilitates the insertion and folding of com

  15. Integral membrane protein structure determination using pseudocontact shifts

    E-Print Network [OSTI]

    Crick, Duncan J.; Wang, Jue X.; Graham, Bim; Swarbrick, James D.; Mott, Helen R.; Nietlispach, Daniel

    2015-01-22

    of using PCSs for the determination of membrane protein structures. Here we demonstrate the use of lanthanide tag-induced PCSs as a powerful tool for the global fold determination of pSRII, a seven-helical transmembrane sensor. The approach makes use of PCS... . 2 Superposition of 2D [1H,15N]-TROSY spectra recorded on C2-lanthanide- tagged pSRII V169C, for the diamagnetic reference Y3? (black) and the paramagnetic metals Dy3? (green), Tm3? (blue) and Yb3? (orange). Lines indicate a selection of observed PCSs...

  16. Progress in the analysis of membrane protein structure and function P.J.L. Wertena

    E-Print Network [OSTI]

    de Groot, Bert

    proteins in a two-dimensional protein^ lipid membrane, allowing its atomic structure to be determined: Membrane protein expression; Two-dimensional crystallization; Atomic force microscopy; Three-dimensional- sulinemia, nephrogenic diabetes insipidus, congestive heart failure, liver cirrhosis, cystic ¢brosis, hyper

  17. Molecular basis of endosomal-membrane association for the dengue virus envelope protein

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Rogers, David M.; Kent, Michael S.; Rempe, Susan B.

    2015-01-02

    Dengue virus is coated by an icosahedral shell of 90 envelope protein dimers that convert to trimers at low pH and promote fusion of its membrane with the membrane of the host endosome. We provide the first estimates for the free energy barrier and minimum for two key steps in this process: host membrane bending and protein–membrane binding. Both are studied using complementary membrane elastic, continuum electrostatics and all-atom molecular dynamics simulations. The predicted host membrane bending required to form an initial fusion stalk presents a 22–30 kcal/mol free energy barrier according to a constrained membrane elastic model. Combined continuummore »and molecular dynamics results predict a 15 kcal/mol free energy decrease on binding of each trimer of dengue envelope protein to a membrane with 30% anionic phosphatidylglycerol lipid. The bending cost depends on the preferred curvature of the lipids composing the host membrane leaflets, while the free energy gained for protein binding depends on the surface charge density of the host membrane. The fusion loop of the envelope protein inserts exactly at the level of the interface between the membrane's hydrophobic and head-group regions. As a result, the methods used in this work provide a means for further characterization of the structures and free energies of protein-assisted membrane fusion.« less

  18. Ion Transport in Nanostructured Block Copolymer/Ionic Liquid Membranes

    E-Print Network [OSTI]

    Hoarfrost, Megan Lane

    2012-01-01

    membranes containing ionic liquid could be designed to take advantage of the interesting gas separation

  19. Towards understanding of Nipah virus attachment protein assembly and the role of protein affinity and crowding for membrane curvature events.

    SciTech Connect (OSTI)

    Stachowiak, Jeanne C.; Hayden, Carl C.; Negrete, Oscar A.; Davis, Ryan Wesley; Sasaki, Darryl Yoshio

    2013-10-01

    Pathogenic viruses are a primary threat to our national security and to the health and economy of our world. Effective defense strategies to combat viral infection and spread require the development of understanding of the mechanisms that these pathogens use to invade the host cell. We present in this report results of our research into viral particle recognition and fusion to cell membranes and the role that protein affinity and confinement in lipid domains plays in membrane curvature in cellular fusion and fission events. Herein, we describe 1) the assembly of the G attachment protein of Nipah virus using point mutation studies to define its role in viral particle fusion to the cell membrane, 2) how lateral pressure of membrane bound proteins induce curvature in model membrane systems, and 3) the role of membrane curvature in the selective partitioning of molecular receptors and specific affinity of associated proteins.

  20. Transport coefficients of D1-D5-P system and the membrane paradigm

    E-Print Network [OSTI]

    Yuya Sasai

    2012-01-12

    I discuss a correspondence between string theory and the black hole membrane paradigm in the context of the D1-D5-P system. By using the Kubo formula, I calculate transport coefficients of the effective string model induced by two kinds of minimal scalars. Then, I show that these transport coefficients exactly agree with the corresponding membrane transport coefficients of a five-dimensional near-extremal black hole with three charges.

  1. BCL::MP-Fold: membrane protein structure prediction guided by EPR restraints

    E-Print Network [OSTI]

    Fischer, Axel Walter; Woetzel, Nils; Karakas, Mert; Weiner, Brian; Meiler, Jens

    2015-01-01

    For many membrane proteins the determination of their topology remains a challenge for methods like X-ray crystallography and nuclear magnetic resonance (NMR) spectroscopy. Electron paramagnetic resonance (EPR) spectroscopy has evolved as an alternative technique to study structure and dynamics of membrane proteins. The present study demonstrates the feasibility of membrane protein topology determination using limited EPR distance and accessibility measurements. The BCL::MP-Fold (BioChemical Library membrane protein fold) algorithm assembles secondary structure elements (SSEs) in the membrane using a Monte Carlo Metropolis (MCM) approach. Sampled models are evaluated using knowledge-based potential functions and agreement with the EPR data and a knowledge-based energy function. Twenty-nine membrane proteins of up to 696 residues are used to test the algorithm. The RMSD100 value of the most accurate model is better than 8{\\AA} for twenty-seven, better than 6{\\AA} for twenty-two and better than 4{\\AA} for fifte...

  2. Oxygen transport membrane system and method for transferring heat to catalytic/process reactors

    DOE Patents [OSTI]

    Kelly, Sean M; Kromer, Brian R; Litwin, Michael M; Rosen, Lee J; Christie, Gervase Maxwell; Wilson, Jamie R; Kosowski, Lawrence W; Robinson, Charles

    2014-01-07

    A method and apparatus for producing heat used in a synthesis gas production is provided. The disclosed method and apparatus include a plurality of tubular oxygen transport membrane elements adapted to separate oxygen from an oxygen containing stream contacting the retentate side of the membrane elements. The permeated oxygen is combusted with a hydrogen containing synthesis gas stream contacting the permeate side of the tubular oxygen transport membrane elements thereby generating a reaction product stream and radiant heat. The present method and apparatus also includes at least one catalytic reactor containing a catalyst to promote the stream reforming reaction wherein the catalytic reactor is surrounded by the plurality of tubular oxygen transport membrane elements. The view factor between the catalytic reactor and the plurality of tubular oxygen transport membrane elements radiating heat to the catalytic reactor is greater than or equal to 0.5.

  3. Advanced Hydrogen Transport Membranes for Vision 21 Fossil Fuel Plants

    SciTech Connect (OSTI)

    Carl R. Evenson; Shane E. Roark

    2006-03-31

    The objective of this project was to develop an environmentally benign, inexpensive, and efficient method for separating hydrogen from gas mixtures produced during industrial processes, such as coal gasification. A family of hydrogen separation membranes was developed including single phase mixed conducting ceramics, ceramic/ceramic composites, cermet membranes, cermet membranes containing a hydrogen permeable metal, and intermediate temperature composite layered membranes. Each membrane type had different operating parameters, advantages, and disadvantages that were documented over the course of the project. Research on these membranes progressed from ceramics to cermets to intermediate temperature composite layered membranes. During this progression performance was increased from 0.01 mL x min{sup -1} x cm{sup -2} up to 423 mL x min{sup -1} x cm{sup -2}. Eltron and team membranes not only developed each membrane type, but also membrane surface catalysis and impurity tolerance, creation of thin film membranes, alternative applications such as membrane promoted alkane dehydrogenation, demonstration of scale-up testing, and complete engineering documentation including process and mechanical considerations necessary for inclusion of Eltron membranes in a full scale integrated gasification combined cycle power plant. The results of this project directly led to a new $15 million program funded by the Department of Energy. This new project will focus exclusively on scale-up of this technology as part of the FutureGen initiative.

  4. Cooperative Gating and Spatial Organization of Membrane Proteins through Elastic Interactions

    E-Print Network [OSTI]

    Tristan Ursell; Kerwyn Huang; Eric Peterson; Rob Phillips

    2007-02-14

    Biological membranes are elastic media in which the presence of a transmembrane protein leads to local bilayer deformation. The energetics of deformation allow two membrane proteins in close proximity to influence each other's equilibrium conformation via their local deformations, and spatially organize the proteins based on their geometry. We use the mechanosensitive channel of large conductance (MscL) as a case study to examine the implications of bilayer-mediated elastic interactions on protein conformational statistics and clustering. The deformations around MscL cost energy on the order of 10 kT and extend ~3nm from the protein edge, as such elastic forces induce cooperative gating and we propose experiments to measure these effects. Additionally, since elastic interactions are coupled to protein conformation, we find that conformational changes can severely alter the average separation between two proteins. This has important implications for how conformational changes organize membrane proteins into functional groups within membranes.

  5. LOSS OF PLASMA MEMBRANE PROTEINS OF BULL SPERMATOZOA THROUGH THE FREEZING -THAWING PROCESS

    E-Print Network [OSTI]

    Zaragoza, Universidad de

    ELSEVIER LOSS OF PLASMA MEMBRANE PROTEINS OF BULL SPERMATOZOA THROUGH THE FREEZING -THAWING PROCESS that some cell membrane proteins are lost through the freezing-thawing process. © 1998by ElsevierScience Inc of sperm cells, adsorption would probably be more affected at freezing temperatures, since some

  6. The New York Consortium on Membrane Protein Structure (NYCOMPS): a high-throughput platform for structural

    E-Print Network [OSTI]

    Hendrickson, Wayne A.

    The New York Consortium on Membrane Protein Structure (NYCOMPS): a high-throughput platform Springer Science+Business Media B.V. 2010 Abstract The New York Consortium on Membrane Protein Structure Core Laboratory, New York Structural Biology Center, New York, NY 10027, USA F. Mancia Á M. Zhou

  7. Defining the Free-Energy Landscape of Curvature-Inducing Proteins on Membrane Bilayers

    E-Print Network [OSTI]

    Tourdot, Richard W; Radhakrishnan, Ravi

    2015-01-01

    Curvature-sensing and curvature-remodeling proteins are known to reshape cell membranes, and this remodeling event is essential for key biophysical processes such as tubulation, exocytosis, and endocytosis. Curvature-inducing proteins can act as curvature sensors as well as induce curvature in cell membranes to stabilize emergent high curvature, non-spherical, structures such as tubules, discs, and caveolae. A definitive understanding of the interplay between protein recruitment and migration, the evolution of membrane curvature, and membrane morphological transitions is emerging but remains incomplete. Here, within a continuum framework and using the machinery of Monte Carlo simulations, we introduce and compare three free-energy methods to delineate the free-energy landscape of curvature-inducing proteins on bilayer membranes. We demonstrate the utility of the Widom test-particle/field insertion methodology in computing the excess chemical potentials associated with curvature-inducing proteins on the membra...

  8. Proton transfer via a transient linear water-molecule chain in a membrane protein

    E-Print Network [OSTI]

    Gerwert, Klaus

    Proton transfer via a transient linear water-molecule chain in a membrane protein Erik Freiera,1-resolution protein ground-state structures of proton pumps and channels have revealed internal protein-bound water. An illustration of the formation of a pro- tonated protein-bound water cluster that is actively involved in proton

  9. Transport Properties and Performance of Polymer Electrolyte Membranes for the Hybrid Sulfur Electrolyzer

    E-Print Network [OSTI]

    Weidner, John W.

    Transport Properties and Performance of Polymer Electrolyte Membranes for the Hybrid Sulfur hydrogen efficiently on a large scale.1 This process has the advantage over traditional i.e., coal gasifica

  10. Experimental characterization of an Ion Transport Membrane (ITM) reactor for methane oxyfuel combustion

    E-Print Network [OSTI]

    Apo, Daniel Jolomi

    2012-01-01

    Ion Transport Membranes (ITM) which conduct both electrons and oxygen ions have been investigated experimentally for oxygen separation and fuel (mostly methane) conversion purposes over the last three decades. The fuel ...

  11. Selective Ionic Transport through Tunable Subnanometer Pores in Single-Layer Graphene Membranes

    E-Print Network [OSTI]

    O’Hern, Sean C.

    We report selective ionic transport through controlled, high-density, subnanometer diameter pores in macroscopic single-layer graphene membranes. Isolated, reactive defects were first introduced into the graphene lattice ...

  12. Systems-level design of ion transport membrane oxy-combustion power plants

    E-Print Network [OSTI]

    Mancini, Nicholas D. (Nicholas David)

    2011-01-01

    Oxy-fuel combustion, particularly using an integrated oxygen ion transport membrane (ITM), is a thermodynamically attractive concept that seeks to mitigate the penalties associated with CO 2 capture from power plants. ...

  13. Water Transport in Polymer Electrolyte Membrane Electrolyzers Used to Recycle Anhydrous HCl

    E-Print Network [OSTI]

    Weidner, John W.

    Water Transport in Polymer Electrolyte Membrane Electrolyzers Used to Recycle Anhydrous HCl I is car- ried out in an electrolyzer similar to a H2-O2 polymer electrolyte membrane PEM fuel cell. The DuPont electrolyzer contains flow channels and gas diffusion backings on the anode and the cathode. The flow channels

  14. ADVANCED HYDROGEN TRANSPORT MEMBRANES FOR VISION 21 FOSSIL FUEL PLANTS

    SciTech Connect (OSTI)

    Carl R. Evenson; Anthony F. Sammells; Richard Mackay; Richard Treglio; Sara L. Rolfe; Richard Blair; U. Balachandran; Richard N. Kleiner; James E. Stephan; Frank E. Anderson; Chandra Ratnasamy; Jon P. Wagner; Clive Brereton; Warren Wolfs

    2004-07-26

    During this quarter, work was focused on testing layered composite membranes under varying feed stream flow rates at high pressure. By optimizing conditions, H{sub 2} permeation rates as high as 423 mL {center_dot} min{sup -1} {center_dot} cm{sup -2} at 440 C were measured. Membrane stability was investigated by comparison to composite alloy membranes. Permeation of alloyed membranes showed a strong dependence on the alloying element. Impedance analysis was used to investigate bulk and grain boundary conductivity in cermets. Thin film cermet deposition procedures were developed, hydrogen dissociation catalysts were evaluated, and hydrogen separation unit scale-up issues were addressed.

  15. Interfacial Water-Transport Effects in Proton-Exchange Membranes

    E-Print Network [OSTI]

    Kienitz, Brian

    2010-01-01

    electrolyte fuel cells (PEFC) are an attractive alternativeproton-exchange membrane in a PEFC must serve many functionsenough to operate under harsh PEFC conditions for thousands

  16. Structure and function of the Influenza membrane protein M2 by magic angle spinning NMR and dynamic nuclear polarization

    E-Print Network [OSTI]

    Andreas, Loren B

    2014-01-01

    Determination of the 3D structure of membrane proteins is a frontier that is rapidly being explored due to the importance of membrane proteins in regulating cellular processes and because they are the target of many drugs. ...

  17. In Vitro Transport of a Fluorescent Nuclear Protein and Exclusion of Non-Nuclear Proteins

    E-Print Network [OSTI]

    Forbes, Douglass

    In Vitro Transport of a Fluorescent Nuclear Protein and Exclusion of Non-Nuclear Proteins Donald D microscopic assay for nuclear transport. The assay uses an extract of Xenopus eggs, normal or synthetic nuclei, and a fluorescently labeled nuclear protein, nucleoplasmin. This in vitro system accurately mimics in vivo nuclear

  18. Pinkbar is an epithelial-specific BAR domain protein that generates planar membrane structures

    SciTech Connect (OSTI)

    Pykäläinen, Anette; Boczkowska, Malgorzata; Zhao, Hongxia; Saarikangas, Juha; Rebowski, Grzegorz; Jansen, Maurice; Hakanen, Janne; Koskela, Essi V.; Peränen, Johan; Vihinen, Helena; Jokitalo, Eija; Salminen, Marjo; Ikonen, Elina; Dominguez, Roberto; Lappalainen, Pekka

    2013-05-29

    Bin/amphipysin/Rvs (BAR)-domain proteins sculpt cellular membranes and have key roles in processes such as endocytosis, cell motility and morphogenesis. BAR domains are divided into three subfamilies: BAR- and F-BAR-domain proteins generate positive membrane curvature and stabilize cellular invaginations, whereas I-BAR-domain proteins induce negative curvature and stabilize protrusions. We show that a previously uncharacterized member of the I-BAR subfamily, Pinkbar, is specifically expressed in intestinal epithelial cells, where it localizes to Rab13-positive vesicles and to the plasma membrane at intercellular junctions. Notably, the BAR domain of Pinkbar does not induce membrane tubulation but promotes the formation of planar membrane sheets. Structural and mutagenesis analyses reveal that the BAR domain of Pinkbar has a relatively flat lipid-binding interface and that it assembles into sheet-like oligomers in crystals and in solution, which may explain its unique membrane-deforming activity.

  19. Trafficking of integral membrane proteins of the inner nuclear membrane can be mediated by the ''sorting motif'' of autographa californica nucleopolyhedrovirus odv-e66 

    E-Print Network [OSTI]

    Williamson, Shawn T

    2006-10-30

    , and has been termed the sorting motif (SM). When abundantly expressed, SM-fusions are also detected in the inner nuclear membrane (INM), outer nuclear membrane and endoplasmic reticulum of infected cells, suggesting proteins with the SM use the same...

  20. Ion transport membrane module and vessel system with directed internal gas flow

    DOE Patents [OSTI]

    Holmes, Michael Jerome (Thompson, ND); Ohrn, Theodore R. (Alliance, OH); Chen, Christopher Ming-Poh (Allentown, PA)

    2010-02-09

    An ion transport membrane system comprising (a) a pressure vessel having an interior, an inlet adapted to introduce gas into the interior of the vessel, an outlet adapted to withdraw gas from the interior of the vessel, and an axis; (b) a plurality of planar ion transport membrane modules disposed in the interior of the pressure vessel and arranged in series, each membrane module comprising mixed metal oxide ceramic material and having an interior region and an exterior region; and (c) one or more gas flow control partitions disposed in the interior of the pressure vessel and adapted to change a direction of gas flow within the vessel.

  1. ADVANCED HYDROGEN TRANSPORT MEMBRANES FOR VISION 21 FOSSIL FUEL PLANTS

    SciTech Connect (OSTI)

    Carl R. Evenson; Anthony F. Sammells; Richard T. Treglio; Jim Fisher; U. Balachandran; Richard N. Kleiner; James E. Stephan; Frank E. Anderson; Chandra Ratnasamy; Mahendra Sunkara; Jyothish Thangla; Clive Brereton; Warren Wolfs; James Lockhart

    2005-01-28

    During this quarter work was continued on characterizing the stability of layered composite membranes under a variety of conditions. Membrane permeation was tested up to 100 hours at constant pressure, temperature, and flow rates. In addition, design parameters were completed for a scale-up hydrogen separation demonstration unit. Evaluation of microstructure and effect of hydrogen exposure on BCY/Ni cermet mechanical properties was initiated. The fabrication of new cermets containing high permeability metals is reported and progress in the preparation of sulfur resistant catalysts is discussed. Finally, a report entitled ''Criteria for Incorporating Eltron's Hydrogen Separation Membranes into Vision 21 IGCC Systems and FutureGen Plants'' was completed.

  2. ADVANCED HYDROGEN TRANSPORT MEMBRANES FOR VISION 21 FOSSIL FUEL PLANTS

    SciTech Connect (OSTI)

    Carl R. Evenson; Anthony F. Sammells; Richard T. Treglio; Adam E. Calihman; U. Balachandran; Richard N. Kleiner; James E. Stephan; Frank E. Anderson; Chandra Ratnasamy; Mahendra Sunkara; Jyothish Thangla; Clive Brereton; Warren Wolfs; James Lockhart

    2005-04-30

    During this quarter long term and high pressure hydrogen separation experiments were performed on Eltron's composite layered membranes. Membranes were tested at 400 C and a 300 psig feed stream with 40% hydrogen for up to 400 continuous hours. In addition membranes were tested up to 1000 psig as demonstration of the ability for this technology to meet DOE goals. Progress was made in the development of new hydrogen separation cermets containing high permeability metals. A sulfur tolerant catalyst deposition technique was optimized and engineering work on mechanical and process & control reports was continued.

  3. ADVANCED HYDROGEN TRANSPORT MEMBRANES FOR VISION 21 FOSSIL FUEL PLANTS

    SciTech Connect (OSTI)

    Carl R. Evenson; Anthony F. Sammells; Richard T. Treglio; U. Balachandran; Richard N. Kleiner; James E. Stephan; Frank E. Anderson; Clive Brereton; Warren Wolfs; James Lockhart

    2004-10-21

    During this quarter, work was focused on characterizing the stability of layered composite membranes in a one hundred percent permeate environment. Permeation data was also collected on cermets as a function of thickness. A thin film deposition procedure was used to deposit dense thin BCY/Ni onto a tubular porous support. Thin film tubes were then tested for permeation at ambient pressure. Process flow diagrams were prepared for inclusion of hydrogen separation membranes into IGCC power plants under varying conditions. Finally, membrane promoted alkane dehydrogenation experiments were performed.

  4. Conformational dynamics of interleukin-1beta and protein- membrane interactions

    E-Print Network [OSTI]

    Anderson, William David

    2007-01-01

    et al. (1995). "Protein folding intermediates: native-statethe equilibrium protein folding pathway: structure-basedEnglander, S. W. (2000). "Protein folding intermediates and

  5. Atomic resolution view into the structure–function relationships of the human myelin peripheral membrane protein P2

    SciTech Connect (OSTI)

    Ruskamo, Salla [University of Oulu, Oulu (Finland); University of Oulu, Oulu (Finland); Yadav, Ravi P. [Banaras Hindu University, Varanasi (India); Helmholtz Centre for Infection Research (CSSB-HZI), German Electron Synchrotron (DESY), Hamburg (Germany); Sharma, Satyan; Lehtimäki, Mari [University of Oulu, Oulu (Finland); University of Oulu, Oulu (Finland); Laulumaa, Saara [University of Oulu, Oulu (Finland); University of Oulu, Oulu (Finland); Helmholtz Centre for Infection Research (CSSB-HZI), German Electron Synchrotron (DESY), Hamburg (Germany); Aggarwal, Shweta; Simons, Mikael [Max Planck Institute for Experimental Medicine, Göttingen (Germany); Bürck, Jochen; Ulrich, Anne S. [Karlsruhe Institute for Technology (KIT), Karlsruhe (Germany); Juffer, André H. [University of Oulu, Oulu (Finland); University of Oulu, Oulu (Finland); Kursula, Inari [University of Oulu, Oulu (Finland); Helmholtz Centre for Infection Research (CSSB-HZI), German Electron Synchrotron (DESY), Hamburg (Germany); Kursula, Petri, E-mail: petri.kursula@oulu.fi [University of Oulu, Oulu (Finland); University of Oulu, Oulu (Finland); Helmholtz Centre for Infection Research (CSSB-HZI), German Electron Synchrotron (DESY), Hamburg (Germany); University of Hamburg, Hamburg (Germany)

    2014-01-01

    The structure of the human myelin peripheral membrane protein P2 has been refined at 0.93 Å resolution. In combination with functional experiments in vitro, in vivo and in silico, the fine details of the structure–function relationships in P2 are emerging. P2 is a fatty acid-binding protein expressed in vertebrate peripheral nerve myelin, where it may function in bilayer stacking and lipid transport. P2 binds to phospholipid membranes through its positively charged surface and a hydrophobic tip, and accommodates fatty acids inside its barrel structure. The structure of human P2 refined at the ultrahigh resolution of 0.93 Å allows detailed structural analyses, including the full organization of an internal hydrogen-bonding network. The orientation of the bound fatty-acid carboxyl group is linked to the protonation states of two coordinating arginine residues. An anion-binding site in the portal region is suggested to be relevant for membrane interactions and conformational changes. When bound to membrane multilayers, P2 has a preferred orientation and is stabilized, and the repeat distance indicates a single layer of P2 between membranes. Simulations show the formation of a double bilayer in the presence of P2, and in cultured cells wild-type P2 induces membrane-domain formation. Here, the most accurate structural and functional view to date on P2, a major component of peripheral nerve myelin, is presented, showing how it can interact with two membranes simultaneously while going through conformational changes at its portal region enabling ligand transfer.

  6. Fluctuation-Driven Molecular Transport Through an Asymmetric Membrane Channel Ioan Kosztin1

    E-Print Network [OSTI]

    Kosztin, Ioan

    asymmetry in the presence of nonequilibrium fluctuations, fueled by the cell's metabolism as observed integrity of the cell. However, cell metabolism requires controlled molecular transport across the cell molecules across the membrane down a free energy gradient. Active transport- ers conduct molecules along

  7. Water transport in fuel cell membranes measured by laser interferometry

    E-Print Network [OSTI]

    Kim, Jungik, 1973-

    2009-01-01

    (cont.) The coefficients of electro-osmotic drag were found to increase with the increasing water content, which indicates that the Grotthuss mechanism of proton transfer is not active in the membranes with low water ...

  8. ADVANCED HYDROGEN TRANSPORT MEMBRANES FOR VISION 21 FOSSIL FUEL PLANTS

    SciTech Connect (OSTI)

    Carl R. Evenson; Anthony F. Sammells; Richard T. Treglio; Adam E. Calihman; U. Balachandran; Richard N. Kleiner; James E. Stephan; Frank E. Anderson; Chandra Ratnasamy; Mahendra Sunkara; Jyothish Thangala; Clive Brereton; Warren Wolfs; James Lockhart

    2005-07-29

    During this quarter catalyst stability studies were performed on Eltron's composite layered membranes. In addition, permeation experiments were performed to determine the effect of crystallographic orientation on membrane performance. Sintering conditions were optimized for preparation of new cermets containing high permeability metals. Theoretical calculations were performed to determine potential sulfur tolerant catalysts. Finally, work was continued on mechanical and process & control documentation for a hydrogen separation unit.

  9. Curvature-Mediated Interactions Between Membrane Proteins K. S. Kim,* John Neu,#

    E-Print Network [OSTI]

    Oster, George

    their pairwise repulsions. GLOSSARY a Annulus surrounding a protein a Mean curvature bending modulus b Gaussian curvature bending modulus a1 Dipole coefficient c Projection of S onto the base plane C Protein and by the membrane's elastic properties. In this paper, we examine the deformation field generated by proteins

  10. ADVANCED HYDROGEN TRANSPORT MEMBRANES FOR VISION 21 FOSSIL FUEL PLANTS

    SciTech Connect (OSTI)

    Shane E. Roark; Tony F. Sammells; Adam E. Calihman; Lyrik Y. Pitzman; Pamela M. Van Calcar; Richard A. Mackay; Tom F. Barton; Sara L. Rolfe; Richard N. Kleiner; James E. Stephan; Tim R. Armstrong; Mike J. Holmes; Aaron L. Wagner

    2001-04-30

    Eltron Research Inc., and team members, are developing an environmentally benign, inexpensive, and efficient method for separating hydrogen from gas mixtures produced during industrial processes, such as coal gasification. This project was motivated by the National Energy Technology Laboratory (NETL) Vision 21 initiative which seeks to economically eliminate environmental concerns associated with the use of fossil fuels. This objective is being pursued using dense membranes based in part on Eltron-patented ceramic materials with a demonstrated ability for proton and electron conduction. The technical goals are being addressed by modifying single-phase and composite membrane composition and microstructure to maximize proton and electron conductivity without loss of material stability. Ultimately, these materials must enable hydrogen separation at practical rates under ambient and high-pressure conditions, without deactivation in the presence of feedstream components such as carbon dioxide, water, and sulfur. During this quarter, it was demonstrated that increasing the transition metal loading in a model perovskite composition resulted in an increase in hydrogen flux. Improved flux corresponded to the emergence of additional phases in the ceramic membrane, and highest flux was achieved for a composite consisting of pseudo-cubic and rhombohedral perovskite phases. A 0.9-mm thick membrane of this material generated a hydrogen flux in excess of 0.1 mL/min/cm{sup 2}, which was approximately 35 times greater than analogs with lower transition metal levels. The dopant level and crystal structure also correlated with membrane density and coefficient of thermal expansion, but did not appear to affect grain size or shape. Additionally, preliminary ceramic-metal (cermet) composite membranes demonstrated a 10-fold increase in flux relative to analogous membranes composed of only the ceramic component. The hydrogen flux for these cermet samples corresponded to a conductivity of {approx} 10{sup -3} S/cm, which was consistent with the predicted proton conductivity of the ceramic phase. Increasing the sweep gas flow rate in test reactors was found to significantly increase hydrogen flux, as well as apparent material conductivity for all samples tested. Adding humidity to the feed gas stream produced a small increase in hydrogen flux. However, the catalyst on ceramic membrane surfaces did not affect flux, which suggested that the process was membrane-diffusion limited. Representative samples and fabrication processes were evaluated on the basis of manufacturing practicality. it was determined that optimum membrane densification occurs over a very narrow temperature range for the subject ceramics. Additionally, calcination temperatures currently employed result in powders that are difficult mill and screen. These issues must be addressed to improve large-scale fabricability.

  11. NMR-Based Computational Studies of Membrane Proteins in Explicit Membranes

    E-Print Network [OSTI]

    Cheng, Xi

    2015-05-31

    , Pf1 coat protein was preassembled in a protein/micelle model and simulated in explicit environment. Compared to previous simulations of Pf1 coat protein in bilayers, different protein conformations were observed in these simulations due...

  12. A Complete Transport Validated Model on a Zeolite Membrane for Carbon Dioxide Permeance and Capture

    E-Print Network [OSTI]

    Gkanas, Evangelos I; Stubos, Athanasios K; Makridis, Sofoklis S

    2013-01-01

    The CO2 emissions from major industries cause serious global environment problems and their mitigation is urgently needed. The use of zeolite membranes is a very efficient way in order to capture CO2 from some flue gases. The dominant transport mechanism at low temperature andor high pressure is the diffusion through the membrane. This procedure can be divided in three steps: Adsorption of the molecules of the species in the surface of the membrane, then a driving force gives a path where the species follow inside the membrane and finally the species desorbed from the surface of the membrane. The current work is aimed at developing a simulation model for the CO2 transport through a zeolite membrane and estimate the diffusion phenomenon through a very thin membrane of 150 nm in a Wicke-Kallenbach cell. The cell is cylindrical in shape with diameter of 19 mm and consists of a retentate gas chamber, a permeate gas chamber which are separated by a cylindrical zeolite membrane. This apparatus have been modeled wit...

  13. SEPARATION OF PROTEINS BY ION EXCHANGE AND MEMBRANE CHROMATOGRAPHY: BUFFER COMPOSITION, INTERFERING IMPURITIES AND FOULING CONSIDERATIONS 

    E-Print Network [OSTI]

    Imam, Tahmina

    2010-01-16

    in all studies buffers. The second study consisted of surface modification of microfiltration membranes for protein purification and separation and reduces fouling. This study describes adsorption and fouling of chemically modified microfiltration...

  14. Clusters of proteins in bio-membranes: insights into the roles of interaction potential shapes and of protein diversity

    E-Print Network [OSTI]

    Nicolas Meilhac; Nicolas Destainville

    2011-06-07

    It has recently been proposed that proteins embedded in lipidic bio-membranes can spontaneously self-organize into stable small clusters, or membrane nano-domains, due to the competition between short-range attractive and longer-range repulsive forces between proteins, specific to these systems. In this paper, we carry on our investigation, by Monte Carlo simulations, of different aspects of cluster phases of proteins in bio-membranes. First, we compare different long-range potentials (including notably three-body terms) to demonstrate that the existence of cluster phases should be quite generic. Furthermore, a real membrane contains hundreds of different protein species that are far from being randomly distributed in these nano-domains. We take this protein diversity into account by modulating protein-protein interaction potentials both at short and longer range. We confirm theoretical predictions in terms of biological cluster specialization by deciphering how clusters recruit only a few protein species. In this respect, we highlight that cluster phases can turn out to be an advantage at the biological level, for example by enhancing the cell response to external stimuli.

  15. ADVANCED HYDROGEN TRANSPORT MEMBRANES FOR VISION 21 FOSSIL FUEL PLANTS

    SciTech Connect (OSTI)

    Shane E. Roark; Anthony F. Sammells; Richard Mackay; Stewart R. Schesnack; Scott R. Morrison; Thomas F. Barton; Sara L. Rolfe; U. Balachandran; Richard N. Kleiner; James E. Stephan; Frank E. Anderson; Aaron L. Wagner; Jon P. Wagner

    2003-10-30

    Eltron Research Inc. and team members CoorsTek, Sued Chemie, Argonne National Laboratory, and NORAM are developing an environmentally benign, inexpensive, and efficient method for separating hydrogen from gas mixtures produced during industrial processes, such as coal gasification. This project was motivated by the National Energy Technology Laboratory (NETL) Vision 21 initiative, which seeks to economically eliminate environmental concerns associated with the use of fossil fuels. Over the past 12 months, this project has focused on four basic categories of dense membranes: (1) mixed conducting ceramic/ceramic composites, (2) mixed conducting ceramic/metal (cermet) composites, (3) cermets with hydrogen permeable metals, and (4) layered composites containing hydrogen permeable alloys. Ultimately, these materials must enable hydrogen separation at practical rates under ambient and high-pressure conditions, without deactivation in the presence of feedstream components such as carbon dioxide, water, and sulfur. The ceramic/ceramic composites demonstrate the lowest hydrogen permeation rates, with a maximum of approximately 0.1 mL/min/cm{sup 2} for 0.5-mm thick membranes at 800 to 950 C. Under equivalent conditions, cermets achieve a hydrogen permeation rate near 1 mL/min/cm{sup 2}, and the metal phase also improves structural stability and surface catalysis for hydrogen dissociation. Furthermore, if metals with high hydrogen permeability are used in cermets, permeation rates near 4 mL/min/cm{sup 2} are achievable with relatively thick membranes. Layered composite membranes have by far the highest permeation rates with a maximum flux in excess of 200 mL {center_dot} min{sup -1} {center_dot} cm{sup -2}. Moreover, these permeation rates were achieved at a total pressure differential across the membrane of 450 psi. Based on these results, effort during the next year will focus on this category of membranes. This report contains long-term hydrogen permeation data over eight-months of continuous operation, and permeation results as a function of operating conditions at high pressure for layered composite membranes. Additional progress with cermet and thin film membranes also is presented.

  16. ADVANCED HYDROGEN TRANSPORT MEMBRANES FOR VISION 21 FOSSIL FUEL PLANTS

    SciTech Connect (OSTI)

    Shane E. Roark; Anthony F. Sammells; Richard A. Mackay; Lyrik Y. Pitzman; Thomas A. Zirbel; Stewart R. Schesnack; Thomas F. Barton; Sara L. Rolfe; U. (Balu) Balachandran; Richard N. Kleiner; James E. Stephan; Frank E. Anderson; Aaron L. Wagner; Jon P. Wagner

    2003-01-30

    Eltron Research Inc., and team members CoorsTek, Sued Chemie, and Argonne National Laboratory are developing an environmentally benign, inexpensive, and efficient method for separating hydrogen from gas mixtures produced during industrial processes, such as coal gasification. This project was motivated by the National Energy Technology Laboratory (NETL) Vision 21 initiative which seeks to economically eliminate environmental concerns associated with the use of fossil fuels. This objective is being pursued using dense membranes based in part on Eltron-patented ceramic materials with a demonstrated ability for proton and electron conduction. The technical goals are being addressed by modifying composite membrane composition and microstructure to maximize hydrogen permeation without loss of material stability. Ultimately, these materials must enable hydrogen separation at practical rates under ambient and high-pressure conditions, without deactivation in the presence of feedstream components such as carbon dioxide, water, and sulfur. During this quarter, a composite metal membrane based on an inexpensive hydrogen permeable metal achieved permeation rates in excess of 25 mL/min/cm{sup 2}. Preliminary attempts to incorporate this metal into a cermet were successful, and a thick cermet membrane (0.83 mm) with 40 vol.% metal phase achieved a permeation rate of nearly 0.4 mL/min/cm{sup 2}. Increasing the metal phase content and decreasing membrane thickness should significantly increase permeation, while maintaining the benefits derived from cermets. Two-phase ceramic/ceramic composite membranes had low hydrogen permeability, likely due to interdiffusion of constituents between the phases. However, these materials did demonstrate high resistance to corrosion, and might be good candidates for other composite membranes. Temperature-programmed reduction measurements indicated that model cermet materials absorbed 2.5 times as much hydrogen than the pure ceramic analogs. This characteristic, in addition to higher electron conductivity, likely explains the relatively high permeation for these cermets. Incorporation of catalysts with ceramics and cermets increased hydrogen uptake by 800 to more than 900%. Finally, new high-pressure seals were developed for cermet membranes that maintained a pressure differential of 250 psi. This result indicated that the approach for high-pressure seal development could be adapted for a range of compositions. Other items discussed in this report include mechanical testing, new proton conducting ceramics, supported thin films, and alkane to olefin conversion.

  17. ADVANCED HYDROGEN TRANSPORT MEMBRANES FOR VISION 21 FOSSIL FUEL PLANTS

    SciTech Connect (OSTI)

    Carl R. Evenson; Anthony F. Sammells; Richard Mackay; Scott R. Morrison; Sara L. Rolfe; Richard Blair; U. Balachandran; Richard N. Kleiner; James E. Stephan; Frank E. Anderson; Chandra Ratnasamy; Jon P. Wagner; Clive Brereton; Warren Wolfs

    2004-04-26

    During this quarter, work was focused on testing layered composite membranes under varying feed stream flow rates at high pressure. By optimizing conditions, H{sub 2} permeation rates in excess of 400 mL {center_dot} min{sup -1} {center_dot} cm{sup -2} at 440 C were measured. Membrane stability was characterized by repeated thermal and pressure cycling. The effect of cermet grain size on permeation was determined. Finally, progress is summarized on thin film cermet fabrication, catalyst development, and H{sub 2} separation unit scale up.

  18. Solvation and Ionic Transport in Polymer Electrolyte Membranes

    SciTech Connect (OSTI)

    Zawodzinski, T.A., Jr.; Paddison, S.J.; Reagor, D.; Pratt, L.R.

    1999-06-03

    We developed a general theoretical framework to study the problem of proton solvation and transport in Nafion{reg_sign} and related materials.

  19. Advanced Hydrogen Transport Membranes for Vision 21 Fossil Fuel Plants

    SciTech Connect (OSTI)

    Carl R. Evenson; Richard N. Kleiner; James E. Stephan; Frank E. Anderson

    2006-01-31

    During this quarter of the no cost extension a cermet composition referred to as EC101 containing a high permeability metal and a ceramic phase was prepared for sealing and permeability testing. Several different types of seals were developed and tested. In addition membrane surface stability was characterized.

  20. Advanced Hydrogen Transport Membranes for Vision 21 Fossil Fuel Plants

    SciTech Connect (OSTI)

    Carl R. Evenson; Harold A. Wright; Adam E. Calihman; U. Balachandran; Richard N. Kleiner; James E. Stephan; Frank E. Anderson; Chandra Ratnasamy; Mahendra Sunkara; Jyothish Thangala; Clive Brereton; Warren Wolfs; James Lockhart

    2005-10-31

    During this quarter composite layered membrane size was scaled-up and tested for permeation performance. Sintering conditions were optimized for a new cermet containing a high permeability metal and seals were developed to allow permeability testing. Theoretical calculations were performed to determine potential sulfur tolerant hydrogen dissociation catalysts. Finally, work was finalized on mechanical and process & control documentation for a hydrogen separation unit.

  1. ADVANCED HYDROGEN TRANSPORT MEMBRANES FOR VISION 21 FOSSIL FUEL PLANTS

    SciTech Connect (OSTI)

    Shane E. Roark; Anthony F. Sammells; Richard A. Mackay; Lyrik Y. Pitzman; Thomas A. Zirbel; Thomas F. Barton; Sara L. Rolfe; U. (Balu) Balachandran; Richard N. Kleiner; James E. Stephan; Frank E. Anderson; George Farthing; Dan Rowley; Tim R. Armstrong; R.D. Carneim; P.F. Becher; C-H. Hsueh; Aaron L. Wagner; Jon P. Wagner

    2002-04-30

    Eltron Research Inc., and team members CoorsTek, McDermott Technology, inc., Sued Chemie, Argonne National Laboratory, and Oak Ridge National Laboratory are developing an environmentally benign, inexpensive, and efficient method for separating hydrogen from gas mixtures produced during industrial processes, such as coal gasification. This project was motivated by the National Energy Technology Laboratory (NETL) Vision 21 initiative which seeks to economically eliminate environmental concerns associated with the use of fossil fuels. This objective is being pursued using dense membranes based in part on Eltron-patented ceramic materials with a demonstrated ability for proton and electron conduction. The technical goals are being addressed by modifying single-phase and composite membrane composition and microstructure to maximize proton and electron conductivity without loss of material stability. Ultimately, these materials must enable hydrogen separation at practical rates under ambient and high-pressure conditions, without deactivation in the presence of feedstream components such as carbon dioxide, water, and sulfur.

  2. Interfacial Water-Transport Effects in Proton-Exchange Membranes

    E-Print Network [OSTI]

    Kienitz, Brian

    2010-01-01

    1993, "The Contact Angle  between Water and the Surface of Desorption, and Transport of Water in  Polymer Electrolyte Vaporization?Exchange Model  for Water Sorption and Flux in 

  3. Characterization of Plasma Membrane Proteins from Ovarian Cancer Cells Using Mass Spectrometry

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Springer, David L.; Auberry, Deanna L.; Ahram, Mamoun; Adkins, Joshua N.; Feldhaus, Jane M.; Wahl, Jon H.; Wunschel, David S.; Rodland, Karin D.

    2004-01-01

    To determine how the repertoire of plasma membrane proteins change with disease state, specifically related to cancer, several methods for preparation of plasma membrane proteins were evaluated. Cultured cells derived from stage IV ovarian tumors were grown to 90% confluence and harvested in buffer containing CHAPS detergent. This preparation was centrifuged at low speed to remove insoluble cellular debris resulting in a crude homogenate. Glycosylated proteins in the crude homogenate were selectively enriched using lectin affinity chromatography. The crude homogenate and the lectin purified sample were prepared for mass spectrometric evaluation. The general procedure for protein identification began with trypsinmore »digestion of protein fractions followed by separation by reversed phase liquid chromatography that was coupled directly to a conventional tandem mass spectrometer (i.e. LCQ ion trap). Mass and fragmentation data for the peptides were searched against a human proteome data base using the informatics program SEQUEST. Using this procedure 398 proteins were identified with high confidence, including receptors, membrane-associated ligands, proteases, phosphatases, as well as structural and adhesion proteins. Results indicate that lectin chromatography provides a select subset of proteins and that the number and quality of the identifications improve as does the confidence of the protein identifications for this subset. These results represent the first step in development of methods to separate and successfully identify plasma membrane proteins from advanced ovarian cancer cells. Further characterization of plasma membrane proteins will contribute to our understanding of the mechanisms underlying progression of this deadly disease and may lead to new targeted interventions as well as new biomarkers for diagnosis.« less

  4. Characterization of Plasma Membrane Proteins from Ovarian Cancer Cells Using Mass Spectrometry

    SciTech Connect (OSTI)

    Springer, David L.; Auberry, Deanna L.; Ahram, Mamoun; Adkins, Joshua N.; Feldhaus, Jane M.; Wahl, Jon H.; Wunsch, David M.; Rodland, Karin D.

    2003-01-01

    To determine how the repertoire of plasma membrane proteins change with disease state, specifically related to cancer, several methods for preparation of plasma membrane proteins were evaluated. Cultured cells derived from stage IV ovarian tumors were grown to 90% confluence and harvested in buffer containing CHAPS detergent. This preparation was centrifuged at low speed to remove insoluble cellular debris resulting in a crude homogenate. Glycosylated proteins in the crude homogenate were selectively enriched using lectin affinity chromatography. The crude homogenate and the lectin purified sample were prepared for mass spectrometric evaluation. The general procedure for protein identification began with trypsin digestion of protein fractions followed by separation by reversed phase liquid chromatography that was coupled directly to a conventional tandem mass spectrometer (i.e. LCQ ion trap). Mass and fragmentation data for the peptides were searched against a human proteome data base using the informatics program SEQUEST. Using this procedure 398 proteins were identified with high confidence, including receptors, membrane-associated ligands, proteases, phosphatases, as well as structural and adhesion proteins. Results indicate that lectin chromatography provides a select subset of proteins and that the number and quality of the identifications improve as does the confidence of the protein identifications for this subset. These results represent the first step in development of methods to separate and successfully identify plasma membrane proteins from advanced ovarian cancer cells. Further characterization of plasma membrane proteins will contribute to our understanding of the mechanisms underlying progression of this deadly disease and may lead to new targeted interventions as well as new biomarkers for diagnosis.

  5. Biomimetic materials for protein storage and transport

    DOE Patents [OSTI]

    Firestone, Millicent A. (Elmhurst, IL); Laible, Philip D. (Villa Park, IL)

    2012-05-01

    The invention provides a method for the insertion of protein in storage vehicles and the recovery of the proteins from the vehicles, the method comprising supplying isolated protein; mixing the isolated protein with a fluid so as to form a mixture, the fluid comprising saturated phospholipids, lipopolymers, and a surfactant; cycling the mixture between a first temperature and a second temperature; maintaining the mixture as a solid for an indefinite period of time; diluting the mixture in detergent buffer so as to disrupt the composition of the mixture, and diluting to disrupt the fluid in its low viscosity state for removal of the guest molecules by, for example, dialysis, filtering or chromatography dialyzing/filtering the emulsified solid.

  6. Advanced Hydrogen Transport Membranes for Vision 21 Fossil Fuel Plants

    SciTech Connect (OSTI)

    Carl R. Evenson; Richard N. Kleiner; James E. Stephan; Frank E. Anderson

    2006-04-30

    Eltron Research Inc. and team members CoorsTek, Sued Chemie, Argonne National Laboratory, and NORAM are developing an environmentally benign, inexpensive, and efficient method for separating hydrogen from gas mixtures produced during industrial processes, such as coal gasification. This project was motivated by the National Energy Technology Laboratory (NETL) Vision 21 initiative, which seeks to economically eliminate environmental concerns associated with the use of fossil fuels. Currently, this project is focusing on four basic categories of dense membranes: (1) mixed conducting ceramic/ceramic composites, (2) mixed conducting ceramic/metal (cermet) composites, (3) cermets with hydrogen permeable metals, and (4) layered composites containing hydrogen permeable alloys. Ultimately, these materials must enable hydrogen separation at practical rates under ambient and high-pressure conditions, without deactivation in the presence of feedstream components such as carbon dioxide, water, and sulfur. During this final quarter of the no cost extension several planar membranes of a cermet composition referred to as EC101 containing a high permeability metal and a ceramic phase were prepared and permeability testing was performed.

  7. ADVANCED HYDROGEN TRANSPORT MEMBRANES FOR VISION 21 FOSSIL FUELS PLANTS

    SciTech Connect (OSTI)

    Shane E. Roark; Anthony F. Sammells; Richard Mackay; Stewart Schesnack; Scott Morrison; Thomas A. Zirbel; Thomas F. Barton; Sara L. Rolfe; U. Balachandran; Richard N. Kleiner; James E. Stephan; Frank E. Anderson; Aaron L. Wagner; Jon P. Wagner

    2003-07-31

    Eltron Research Inc. and team members CoorsTek, Sued Chemie, and Argonne National Laboratory are developing an environmentally benign, inexpensive, and efficient method for separating hydrogen from gas mixtures produced during industrial processes, such as coal gasification. This project was motivated by the National Energy Technology Laboratory (NETL) Vision 21 initiative, which seeks to economically eliminate environmental concerns associated with the use of fossil fuels. Currently, this project is focusing on four basic categories of dense membranes: (1) mixed conducting ceramic/ceramic composites, (2) mixed conducting ceramic/metal (cermet) composites, (3) cermets with hydrogen permeable metals, and (4) layered composites containing hydrogen permeable alloys. Ultimately, these materials must enable hydrogen separation at practical rates under ambient and high-pressure conditions, without deactivation in the presence of feedstream components such as carbon dioxide, water, and sulfur. This report presents hydrogen permeation data during long term tests and tests at high pressure in addition to progress with cermet, ceramic/ceramic, and thin film membranes.

  8. ADVANCED HYDROGEN TRANSPORT MEMBRANES FOR VISION 21 FOSSIL FUEL PLANTS

    SciTech Connect (OSTI)

    Shane E. Roark; Anthony F. Sammells; Richard A. Mackay; Lyrik Y. Pitzman; Thomas A. Zirbel; Stewart Schesnack; Thomas F. Barton; Sara L. Rolfe; U. (Balu) Balachandran; Richard N. Kleiner; James E. Stephan; Frank E. Anderson; Aaron L. Wagner; Jon P. Wagner

    2003-04-30

    Eltron Research Inc. and team members CoorsTek, Sued Chemie, and Argonne National Laboratory are developing an environmentally benign, inexpensive, and efficient method for separating hydrogen from gas mixtures produced during industrial processes, such as coal gasification. This project was motivated by the National Energy Technology Laboratory (NETL) Vision 21 initiative, which seeks to economically eliminate environmental concerns associated with the use of fossil fuels. Currently, this project is focusing on four basic categories of dense membranes: (i) mixed conducting ceramic/ceramic composites, (ii) mixed conducting ceramic/metal (cermet) composites, (iii) cermets with hydrogen permeable metals, and (iv) hydrogen permeable alloys. Ultimately, these materials must enable hydrogen separation at practical rates under ambient and high-pressure conditions, without deactivation in the presence of feedstream components such as carbon dioxide, water, and sulfur. This report describes resent results for long-term hydrogen permeation and chemical stability measurements, new mixed conducting cermets, progress in cermet, thin film, and thin-walled tube fabrication, hydrogen absorption measurements for selected compositions, and membrane facilitated alkane to olefin conversion.

  9. How the Membrane Protein AmtB Transports Ammonia

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Doorway for Letting Ammonia into Cells Like any factory, a biological cell takes in raw materials and energy and expels waste products. What goes in and out passes through the cell...

  10. Structures for Three Membrane Transport Proteins Yield Functional Insights

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach Home RoomPreservation ofAlbuquerque|SensitiveAprilPhotonStructure of DNA-BoundFinanceStructures for

  11. Structures for Three Membrane Transport Proteins Yield Functional Insights

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power AdministrationRobust,Field-effect PhotovoltaicsStructure and Receptorsurvivor 8 StructureStructures

  12. Structures for Three Membrane Transport Proteins Yield Functional Insights

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power AdministrationRobust,Field-effect PhotovoltaicsStructure and Receptorsurvivor 8

  13. Structures for Three Membrane Transport Proteins Yield Functional Insights

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power AdministrationRobust,Field-effect PhotovoltaicsStructure and Receptorsurvivor 8Structures for Three

  14. Structures for Three Membrane Transport Proteins Yield Functional Insights

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power AdministrationRobust,Field-effect PhotovoltaicsStructure and Receptorsurvivor 8Structures for

  15. How the Membrane Protein AmtB Transports Ammonia

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach Home Room NewsInformation CurrentHenry Bellamy, Ph.D.Food Drive HolidayHoursa Wind Turbine Works HowHow

  16. How the Membrane Protein AmtB Transports Ammonia

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration would likeUniverse (JournalvivoHigh energyHighlandWorkshop-SummerHow is the Data QualityHowHow

  17. How the Membrane Protein AmtB Transports Ammonia

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration would likeUniverse (JournalvivoHigh energyHighlandWorkshop-SummerHow is the Data

  18. How the Membrane Protein AmtB Transports Ammonia

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration would likeUniverse (JournalvivoHigh energyHighlandWorkshop-SummerHow is the DataHow the

  19. Bioenergetics and mechanical actuation analysis with membrane transport experiments for use in biomimetic

    E-Print Network [OSTI]

    Giurgiutiu, Victor

    Bioenergetics and mechanical actuation analysis with membrane transport experiments for use considers the mechanics and bioenergetics of a prototype nastic structure system consisting of an array by the hydrolysis of adenosine triphosphate. After reviewing the biochemistry and bioenergetics of the active

  20. Cathode and electrolyte materials for solid oxide fuel cells and ion transport membranes

    SciTech Connect (OSTI)

    Jacobson, Allan J; Wang, Shuangyan; Kim, Gun Tae

    2014-01-28

    Novel cathode, electrolyte and oxygen separation materials are disclosed that operate at intermediate temperatures for use in solid oxide fuel cells and ion transport membranes based on oxides with perovskite related structures and an ordered arrangement of A site cations. The materials have significantly faster oxygen kinetics than in corresponding disordered perovskites.

  1. Transport Phenomena in Polymer Electrolyte Membranes I. Modeling Framework

    E-Print Network [OSTI]

    Struchtrup, Henning

    and optimization of fuel cells in a design and development environment. Kreuer et al.19 recently presented of ongoing efforts to develop more comprehensive compu- tational fuel cell model14-18 that allow analysis of the fundamental transport mechanisms. In the context of multidimensional fuel cell modeling, practical

  2. Directed transport as a mechanism for protein folding in vivo

    E-Print Network [OSTI]

    Ernesto Gonzalez-Candela; Victor Romero-Rochin

    2009-09-23

    We propose a model for protein folding in vivo based on a Brownian-ratchet mechanism in the multidimensional energy landscape space. The device is able to produce directed transport taking advantage of the assumed intrinsic asymmetric properties of the proteins and employing the consumption of energy provided by an external source. Through such a directed transport phenomenon, the polypeptide finds the native state starting from any initial state in the energy landscape with great efficacy and robustness, even in the presence of different type of obstacles. This model solves Levinthal's paradox without requiring biased transition probabilities but at the expense of opening the system to an external field.

  3. Directed transport as a mechanism for protein folding in vivo

    E-Print Network [OSTI]

    Gonzalez-Candela, Ernesto

    2009-01-01

    We propose a model for protein folding in vivo based on a Brownian-ratchet mechanism in the multidimensional energy landscape space. The device is able to produce directed transport taking advantage of the assumed intrinsic asymmetric properties of the proteins and employing the consumption of energy provided by an external source. Through such a directed transport phenomenon, the polypeptide finds the native state starting from any initial state in the energy landscape with great efficacy and robustness, even in the presence of different type of obstacles. This model solves Levinthal's paradox without requiring biased transition probabilities but at the expense of opening the system to an external field.

  4. Communication Between the Cell Membrane and the Nucleus: Role of Protein Compartmentalization

    SciTech Connect (OSTI)

    Lelievre, Sophie A; Bissell, Mina J

    1998-10-21

    Understanding how the information is conveyed from outside to inside the cell is a critical challenge for all biologists involved in signal transduction. The flow of information initiated by cell-cell and cell-extracellular matrix contacts is mediated by the formation of adhesion complexes involving multiple proteins. Inside adhesion complexes, connective membrane skeleton (CMS) proteins are signal transducers that bind to adhesion molecules, organize the cytoskeleton, and initiate biochemical cascades. Adhesion complex-mediated signal transduction ultimately directs the formation of supramolecular structures in the cell nucleus, as illustrated by the establishment of multi complexes of DNA-bound transcription factors, and the redistribution of nuclear structural proteins to form nuclear subdomains. Recently, several CMS proteins have been observed to travel to the cell nucleus, suggesting a distinctive role for these proteins in signal transduction. This review focuses on the nuclear translocation of structural signal transducers of the membrane skeleton and also extends our analysis to possible translocation of resident nuclear proteins to the membrane skeleton. This leads us to envision the communication between spatially distant cellular compartments (i.e., membrane skeleton and cell nucleus) as a bidirectional flow of information (a dynamic reciprocity) based on subtle multilevel structural and biochemical equilibria. At one level, it is mediated by the interaction between structural signal transducers and their binding partners, at another level it may be mediated by the balance and integration of signal transducers in different cellular compartments.

  5. Mesoscale computational studies of membrane bilayer remodeling by curvature-inducing proteins

    E-Print Network [OSTI]

    N. Ramakrishnan; P. B. Sunil Kumar; Ravi Radhakrishnan

    2015-10-16

    Biological membranes constitute boundaries of cells and cell organelles. Physico-chemical mechanisms at the atomic scale are dictated by protein-lipid interaction strength, lipid composition, lipid distribution in the vicinity of the protein, shape and amino acid composition of the protein, and its amino acid contents. The specificity of molecular interactions together with the cooperativity of multiple proteins induce and stabilize complex membrane shapes at the mesoscale. These shapes span a wide spectrum ranging from the spherical plasma membrane to the complex cisternae of the Golgi apparatus. Mapping the relation between the protein-induced deformations at the molecular scale and the resulting mesoscale morphologies is key to bridging cellular experiments across the various length scales. In this review, we focus on the theoretical and computational methods used to understand the phenomenology underlying protein-driven membrane remodeling. The suite of methods discussed here can be tailored to applications in specific cellular settings such as endocytosis during cargo trafficking and tubulation of filopodial structures in migrating cells, which makes these methods a powerful complement to experimental studies.

  6. Formation of polyhedral vesicles and polygonal membrane tubes induced by banana-shaped proteins

    E-Print Network [OSTI]

    Noguchi, Hiroshi

    2015-01-01

    The shape transformations of fluid membranes induced by curved protein rods are studied using meshless membrane simulations. The rod assembly at low rod density induces a flat membrane tube and oblate vesicle. It is found that the polyhedral shapes are stabilized at high rod densities. The discrete shape transition between triangular and buckled discoidal tubes is obtained and their curvature energies are analyzed by a simple geometric model. For vesicles, triangular hosohedron and elliptic-disk shapes are formed in equilibrium, whereas tetrahedral and triangular prism shapes are obtained as metastable states.

  7. Protein motors induced enhanced diffusion in intracellular transport

    E-Print Network [OSTI]

    I. Santamaria-Holek; M. H. Vainstein; J. M. Rubi; F. A. Oliveira

    2009-02-04

    Diffusion of transported particles in the intracellular medium is described by means of a generalized diffusion equation containing forces due to the cytoskeleton network and to the protein motors. We find that the enhanced diffusion observed in experiments depends on the nature of the force exerted by the protein motors and on parameters characterizing the intracellular medium which is described in terms of a generalized Debye spectrum for the noise density of states.

  8. Quantitative description of ion transport via plasma membrane of yeast and small cells

    E-Print Network [OSTI]

    Vadim Volkov

    2012-12-18

    Modelling of ion transport via plasma membrane needs identification and quantitative understanding of the involved processes. Brief characterisation of ion transport systems of a yeast cell (Pma1, Ena1, TOK1, Nha1, Trk1, Trk2, non-selective cation conductance) and estimates concerning the number of molecules of each transporter per a cell allow predicting the corresponding ion flows. Comparison of ion transport in small yeast cell and several animal cell types is provided and importance of cell volume to surface ratio is stressed. Role of cell wall and lipid rafts is discussed in aspect of required increase in spatial and temporary resolution of measurements. Conclusions are formulated to describe specific features of ion transport in a yeast cell. Potential directions of future research are outlined based on the assumptions.

  9. Influence of protein and lipid domains on the structure, fluidity and phase behavior of lipid bilayer membranes

    E-Print Network [OSTI]

    Horton, Margaret R. (Margaret Ruth)

    2007-01-01

    The lipid bilayer forms the basic structure of the cell membrane, which is a heterogeneous matrix of proteins and lipids that provides a barrier between the interior of a cell and its outside environment. Protein and lipid ...

  10. Catalyzed CO.sub.2-transport membrane on high surface area inorganic support

    DOE Patents [OSTI]

    Liu, Wei

    2014-05-06

    Disclosed are membranes and methods for making the same, which membranes provide improved permeability, stability, and cost-effective manufacturability, for separating CO.sub.2 from gas streams such as flue gas streams. High CO.sub.2 permeation flux is achieved by immobilizing an ultra-thin, optionally catalyzed fluid layer onto a meso-porous modification layer on a thin, porous inorganic substrate such as a porous metallic substrate. The CO.sub.2-selective liquid fluid blocks non-selective pores, and allows for selective absorption of CO.sub.2 from gas mixtures such as flue gas mixtures and subsequent transport to the permeation side of the membrane. Carbon dioxide permeance levels are in the order of 1.0.times.10.sup.-6 mol/(m.sup.2sPa) or better. Methods for making such membranes allow commercial scale membrane manufacturing at highly cost-effective rates when compared to conventional commercial-scale CO.sub.2 separation processes and equipment for the same and such membranes are operable on an industrial use scale.

  11. Research Focus New proteins in the apicoplast membranes: time to

    E-Print Network [OSTI]

    McFadden, Geoff

    , isoprene precursors, iron­sulfur clusters and haem [2,3], and these pathways would seem to make mining has identified 500 proteins that are likely to reside in the apicoplast stroma, but little

  12. Analysis of membrane proteins in metagenomics: Networks of correlated environmental features

    E-Print Network [OSTI]

    impacts, such as pollution and climate change. We show that there is widespread variation in membrane and that the occurrence of iron transporters is connected to the amount of shipping, pollution, and iron-containing dust of spectral tuning of the light-driven proton pump proteorhodopsin reveals a relationship between a single

  13. Renaturing Membrane Proteins in the Lipid Cubic Phase, a Nanoporous

    Office of Scientific and Technical Information (OSTI)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of NaturalDukeWakefieldSulfateSciTech ConnectSpeedingConnect(Conference) |(Patent)(Conference) |Membrane Mimetic

  14. Transport coefficients, membrane couplings and universality at extremality

    E-Print Network [OSTI]

    Miguel F. Paulos

    2009-11-20

    We present an efficient method for computing the zero frequency limit of transport coefficients in strongly coupled field theories described holographically by higher derivative gravity theories. Hydrodynamic parameters such as shear viscosity and conductivity can be obtained by computing residues of poles of the off-shell lagrangian density. We clarify in which sense these coefficients can be thought of as effective couplings at the horizon, and present analytic, Wald-like formulae for the shear viscosity and conductivity in a large class of general higher derivative lagrangians. We show how to apply our methods to systems at zero temperature but finite chemical potential. Our results imply that such theories satisfy $\\eta/s=1/4\\pi$ universally in the Einstein-Maxwell sector. Likewise, the zero frequency limit of the real part of the conductivity for such systems is shown to be universally zero, and we conjecture that higher derivative corrections in this sector do not modify this result to all orders in perturbation theory.

  15. Transport Membrane Condenser for Water and Energy Recovery from Power Plant Flue Gas

    SciTech Connect (OSTI)

    Dexin Wang

    2012-03-31

    The new waste heat and water recovery technology based on a nanoporous ceramic membrane vapor separation mechanism has been developed for power plant flue gas application. The recovered water vapor and its latent heat from the flue gas can increase the power plant boiler efficiency and reduce water consumption. This report describes the development of the Transport Membrane Condenser (TMC) technology in details for power plant flue gas application. The two-stage TMC design can achieve maximum heat and water recovery based on practical power plant flue gas and cooling water stream conditions. And the report includes: Two-stage TMC water and heat recovery system design based on potential host power plant coal fired flue gas conditions; Membrane performance optimization process based on the flue gas conditions, heat sink conditions, and water and heat transport rate requirement; Pilot-Scale Unit design, fabrication and performance validation test results. Laboratory test results showed the TMC system can exact significant amount of vapor and heat from the flue gases. The recovered water has been tested and proved of good quality, and the impact of SO{sub 2} in the flue gas on the membrane has been evaluated. The TMC pilot-scale system has been field tested with a slip stream of flue gas in a power plant to prove its long term real world operation performance. A TMC scale-up design approach has been investigated and an economic analysis of applying the technology has been performed.

  16. DOI: 10.1002/cphc.200800703 How Does a Membrane Protein Achieve a Vectorial Proton

    E-Print Network [OSTI]

    Gerwert, Klaus

    DOI: 10.1002/cphc.200800703 How Does a Membrane Protein Achieve a Vectorial Proton Transfer Via Water Molecules? Steffen Wolf, Erik Freier, and Klaus Gerwert*[a] Introduction How protons migrate Grotthuss[1] proposed the transfer along water molecule chains and Eigen[2] identified fast proton

  17. ER Membrane Protein Complex Required for Nuclear Fusion Davis T.W. Ng and Peter Walter

    E-Print Network [OSTI]

    Walter, Peter

    ER Membrane Protein Complex Required for Nuclear Fusion Davis T.W. Ng and Peter Walter Department is localized to the luminal (i.e., noncytoplasmic) face of the ER mem- brane, yet nuclear fusion must initiate of Sec63p, Sec71p, and Sec72p plays a central role in mediating nuclear mem- brane fusion and requires ER

  18. ATP-independent reversal of a membrane protein aggregate by a chloroplast SRP subunit

    SciTech Connect (OSTI)

    Jaru-Ampornpan, Peera; Shen, Kuang; Lam, Vinh Q.; Ali, Mona; Doniach, Sebastian; Jia, Tony Z.; Shan, Shu-ou (CIT); (Stanford)

    2010-07-23

    Membrane proteins impose enormous challenges to cellular protein homeostasis during their post-translational targeting, and they require chaperones to keep them soluble and translocation competent. Here we show that a novel targeting factor in the chloroplast signal recognition particle (cpSRP), cpSRP43, is a highly specific molecular chaperone that efficiently reverses the aggregation of its substrate proteins. In contrast to 'ATPases associated with various cellular activities' (AAA{sup +}) chaperones, cpSRP43 uses specific binding interactions with its substrate to mediate its 'disaggregase' activity. This disaggregase capability can allow targeting machineries to more effectively capture their protein substrates and emphasizes a close connection between protein folding and trafficking processes. Moreover, cpSRP43 provides the first example to our knowledge of an ATP-independent disaggregase and shows that efficient reversal of protein aggregation can be attained by specific binding interactions between a chaperone and its substrate.

  19. Numerical investigation of interfacial transport resistance due to water droplets in proton exchange membrane fuel cell air channels

    E-Print Network [OSTI]

    Kandlikar, Satish

    (GDL) interface is needed in modelling the performance of a proton exchange membrane fuel cell (PEMFC representative case of a PEMFC air flow channel. The results show that the droplets significantly increase Sh of a proton exchange membrane fuel cell (PEMFC) is an active area of research. The O2 transport loss becomes

  20. Mathematical modeling of liquid/liquid hollow fiber membrane contactor accounting for interfacial transport phenomena: Extraction of lanthanides as a surrogate for actinides

    SciTech Connect (OSTI)

    Rogers, J.D.

    1994-08-04

    This report is divided into two parts. The second part is divided into the following sections: experimental protocol; modeling the hollow fiber extractor using film theory; Graetz model of the hollow fiber membrane process; fundamental diffusive-kinetic model; and diffusive liquid membrane device-a rigorous model. The first part is divided into: membrane and membrane process-a concept; metal extraction; kinetics of metal extraction; modeling the membrane contactor; and interfacial phenomenon-boundary conditions-applied to membrane transport.

  1. A Biophysical Study of Integral Membrane Protein Folding John F. Hunt,, Thomas N. Earnest,|, Olaf Bousche,| Krishna Kalghatgi,3,# Karlyne Reilly,,O Csaba Horvath,3

    E-Print Network [OSTI]

    A Biophysical Study of Integral Membrane Protein Folding John F. Hunt,,§ Thomas N. Earnest,|, Olaf on the process of integral membrane protein folding and assembly, we have conducted a biophysical dissection suggest that the folding of R-helical integral membrane proteins may proceed spontaneously. However

  2. Mechanism of Proton Transport in Proton Exchange Membranes: Insights from Computer Simulation

    SciTech Connect (OSTI)

    Gregory A. Voth

    2010-11-30

    The solvation and transport of hydrated protons in proton exchange membranes (PEMs) such as NafionTM will be described using a novel multi-state reactive molecular dynamics (MD) approach, combined with large scale MD simulation to help probe various PEM morphological models. The multi-state MD methodology allows for the treatment of explicit (Grotthuss) proton shuttling and charge defect delocalization which, in turn, can strongly influence the properties of the hydrated protons in various aqueous and complex environments. A significant extension of the methodology to treat highly acidic (low pH) environments such as the hydrophilic domains of a PEM will be presented. Recent results for proton solvation and transport in NafionTM will be described which reveal the significant role of Grotthuss shuttling and charge defect delocalization on the excess proton solvation structures and transport properties. The role of PEM hydration level and morphology on these properties will also be described.

  3. EFFICIENT OXYGEN SEPARATION MEMBRANE

    E-Print Network [OSTI]

    Mucina, Ladislav

    EFFICIENT OXYGEN SEPARATION MEMBRANE Summary of technology Oxygen can be separated from air using a uniquely structured ceramic ion transport membrane for oxygen separation thatshowsremarkablyhighflux © Curtin University 2013 Gas diffusion in conventional membrane Gas diffusion in new membrane New membrane

  4. Two- or three-step assembly of banana-shaped proteins coupled with shape transformation of lipid membranes

    E-Print Network [OSTI]

    Hiroshi Noguchi

    2014-08-22

    BAR superfamily proteins have a banana-shaped domain that causes the local bending of lipid membranes. We study as to how such a local anisotropic curvature induces effective interaction between proteins and changes the global shape of vesicles and membrane tubes using meshless membrane simulations. The proteins are modeled as banana-shaped rods strongly adhered to the membrane. Our study reveals that the rods assemble via two continuous directional phase separations unlike a conventional two-dimensional phase separation. As the rod curvature increases, in the membrane tube the rods assemble along the azimuthal direction and subsequently along the longitudinal direction accompanied by shape transformation of the tube. In the vesicle, in the addition to these two assembly processes, further increase in the rod curvature induces tubular scaffold formation.

  5. Ideal Desalination through Graphyne-4 Membrane: Nanopores for Quantized Water Transport

    E-Print Network [OSTI]

    Chongqin Zhu; Hui Li; Xiao Cheng Zeng; Sheng Meng

    2013-06-30

    Graphyne-4 sheet exhibits promising potential for nanoscale desalination to achieve both high water permeability and salt rejection rate. Extensive molecular dynamics simulations on pore-size effects suggest that graphyne-4, with 4 acetylene bonds between two adjacent phenyl rings, has the best performance with 100% salt rejection and an unprecedented water permeability, to our knowledge, of ~13L/cm2/day/MPa, about 10 times higher than the state-of-the-art nanoporous graphene reported previously (Nano Lett.s 2012, 12, 3602-3608). In addition, the membrane entails very low energy consumption for producing 1m3 of fresh water, i.e., 3.6e-3 kWh/m3, three orders of magnitude less than the prevailing commercial membranes based on reverse osmosis. Water flow rate across the graphyne-4 sheet exhibits intriguing nonlinear dependence on the pore size owing to the quantized nature of water flow at the nanoscale. Such novel transport behavior has important implications to the design of highly effective and efficient desalination membranes.

  6. Rescuing Those Left Behind. Recovering and Characterizing Underdigested Membrane and Hydrophobic Proteins To Enhance Proteome Measurement Depth

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Giannone, Richard J.; Wurch, Louie L.; Podar, Mircea; Hettich, Robert L.

    2015-07-21

    The marine archaeon Nanoarchaeum equitans is dependent on direct physical contact with its host, the hyperthermophile Ignicoccus hospitalis. This interaction is thought to be membrane-associated, involving a myriad of membrane-anchored proteins; proteomic efforts to better characterize this difficult to analyze interface are paramount to uncovering the mechanism of their association. By extending multienzyme digestion strategies that use sample filtration to recover underdigested proteins for reprocessing/consecutive proteolytic digestion, we applied chymotrypsin to redigest the proteinaceous material left over after initial proteolysis with trypsin of sodium dodecyl sulfate (SDS)-extracted I. hospitalis-N. equitansproteins. We show that proteins with increased hydrophobic character, including membranemore »proteins with multiple transmembrane helices, are enriched and recovered in the underdigested fraction. Chymotryptic reprocessing provided significant sequence coverage gains in both soluble and hydrophobic proteins alike, with the latter benefiting more so in terms of membrane protein representation. These gains were despite a large proportion of high-quality peptide spectra remaining unassigned in the underdigested fraction suggesting high levels of protein modification on these often surface-exposed proteins. Importantly, these gains were achieved without applying extensive fractionation strategies usually required for thorough characterization of membrane-associated proteins and were facilitated by the generation of a distinct, complementary set of peptides that aid in both the identification and quantitation of this important, under-represented class of proteins.« less

  7. Engineering Development of Ceramic Membrane Reactor System for Converting Natural Gas to Hydrogen and Synthesis Gas for Liquid Transportation Fuels

    SciTech Connect (OSTI)

    Air Products and Chemicals

    2008-09-30

    An Air Products-led team successfully developed ITM Syngas technology from the concept stage to a stage where a small-scale engineering prototype was about to be built. This technology produces syngas, a gas containing carbon monoxide and hydrogen, by reacting feed gas, primarily methane and steam, with oxygen that is supplied through an ion transport membrane. An ion transport membrane operates at high temperature and oxygen ions are transported through the dense membrane's crystal lattice when an oxygen partial pressure driving force is applied. This development effort solved many significant technical challenges and successfully scaled-up key aspects of the technology to prototype scale. Throughout the project life, the technology showed significant economic benefits over conventional technologies. While there are still on-going technical challenges to overcome, the progress made under the DOE-funded development project proved that the technology was viable and continued development post the DOE agreement would be warranted.

  8. The effects of storage time on vitelline membrane protein banding patterns and interior egg quality of eggs from non-molted and molted hens 

    E-Print Network [OSTI]

    Kelley, Angela Jean

    2004-09-30

    Vitelline membrane strength plays a role in preventing contamination of albumen by yolk during separation and is important to food safety. Two experiments were conducted to determine if a relationship exists between vitelline membrane protein...

  9. Ion Sorption, Diffusion and Transport in Polymer Membranes J. Kamcev, N. Yan, E.S. Jang, M. Galizia, D. R. Paul, and B. D. Freeman

    E-Print Network [OSTI]

    Turro, Nicholas J.

    fellows performing fundamental research in gas and liquid separations using polymer membranes and barrier separation membrane materials, such as new materials for water/ion separation, hydrogen separation, naturalIon Sorption, Diffusion and Transport in Polymer Membranes J. Kamcev, N. Yan, E.S. Jang, M. Galizia

  10. Palmitoylation of SARS-CoV S protein is necessary for partitioning into detergent-resistant membranes and cell-cell fusion but not interaction with M protein

    SciTech Connect (OSTI)

    McBride, Corrin E.; Machamer, Carolyn E.

    2010-09-15

    Coronaviruses are enveloped RNA viruses that generally cause mild disease in humans. However, the recently emerged coronavirus that caused severe acute respiratory syndrome (SARS-CoV) is the most pathogenic human coronavirus discovered to date. The SARS-CoV spike (S) protein mediates virus entry by binding cellular receptors and inducing fusion between the viral envelope and the host cell membrane. Coronavirus S proteins are palmitoylated, which may affect function. Here, we created a non-palmitoylated SARS-CoV S protein by mutating all nine cytoplasmic cysteine residues. Palmitoylation of SARS-CoV S was required for partitioning into detergent-resistant membranes and for cell-cell fusion. Surprisingly, however, palmitoylation of S was not required for interaction with SARS-CoV M protein. This contrasts with the requirement for palmitoylation of mouse hepatitis virus S protein for interaction with M protein and may point to important differences in assembly and infectivity of these two coronaviruses.

  11. A Discussion of Conductivity Testing in High Temperature Membranes (lessons learned in assessing transport)

    Broader source: Energy.gov [DOE]

    Presentation on conductivity testing in high temperature membranes given by Jim Boncella of Los Alamos National Laboratory at the High Temperature Membrane Working Group meeting in October 2005.

  12. Effective Transport Properties Accounting for Electrochemical Reactions of Proton-Exchange Membrane Fuel Cell Catalyst Layers

    SciTech Connect (OSTI)

    Pharoah, Jon; Choi, Hae-Won; Chueh, Chih-Che; Harvey, David

    2011-07-01

    There has been a rapidly growing interest in three-dimensional micro-structural reconstruction of fuel cell electrodes so as to derive more accurate descriptors of the pertinent geometric and effective transport properties. Due to the limited accessibility of experiments based reconstruction techniques, such as dual-beam focused ion beam-scanning electro microscopy or micro X-Ray computed tomography, within sample micro-structures of the catalyst layers in polymer electrolyte membrane fuel cells (PEMFCs), a particle based numerical model is used in this study to reconstruct sample microstructure of the catalyst layers in PEMFCs. Then the reconstructed sample structure is converted into the computational grid using body-fitted/cut-cell based unstructured meshing technique. Finally, finite volume methods (FVM) are applied to calculate effective properties on computational sample domains.

  13. Experimental phasing for structure determination using membrane-protein crystals grown by the lipid cubic phase method

    SciTech Connect (OSTI)

    Li, Dianfan; Pye, Valerie E.; Caffrey, Martin, E-mail: martin.caffrey@tcd.ie [Trinity College Dublin, Dublin (Ireland)

    2015-01-01

    Very little information is available in the literature concerning the experimental heavy-atom phasing of membrane-protein structures where the crystals have been grown using the lipid cubic phase (in meso) method. In this paper, pre-labelling, co-crystallization, soaking, site-specific mercury binding to genetically engineered single-cysteine mutants and selenomethionine labelling as applied to an integral membrane kinase crystallized in meso are described. An assay to assess cysteine accessibility for mercury labelling of membrane proteins is introduced. Despite the marked increase in the number of membrane-protein structures solved using crystals grown by the lipid cubic phase or in meso method, only ten have been determined by SAD/MAD. This is likely to be a consequence of the technical difficulties associated with handling proteins and crystals in the sticky and viscous hosting mesophase that is usually incubated in glass sandwich plates for the purposes of crystallization. Here, a four-year campaign aimed at phasing the in meso structure of the integral membrane diacylglycerol kinase (DgkA) from Escherichia coli is reported. Heavy-atom labelling of this small hydrophobic enzyme was attempted by pre-labelling, co-crystallization, soaking, site-specific mercury binding to genetically engineered single-cysteine mutants and selenomethionine incorporation. Strategies and techniques for special handling are reported, as well as the typical results and the lessons learned for each of these approaches. In addition, an assay to assess the accessibility of cysteine residues in membrane proteins for mercury labelling is introduced. The various techniques and strategies described will provide a valuable reference for future experimental phasing of membrane proteins where crystals are grown by the lipid cubic phase method.

  14. Transport of organelles by elastically coupled motor proteins

    E-Print Network [OSTI]

    Deepak Bhat; Manoj Gopalakrishnan

    2014-12-17

    Motor-driven intracellular transport is a complex phenomenon where multiple motor proteins attached to a cargo are simultaneously engaged in pulling activity, often leading to tug-of-war and bidirectional motion. However, most mathematical and computational models ignore the details of the motor-cargo interaction. A few papers have studied more realistic models of cargo transport by including elastic motor-cargo coupling, but either restricts the number of motors and/or uses purely phenomenological forms for energy-dependent hopping rates. Here, we study a generic Model In which N motors are elastically coupled to a cargo, which itself is subject to thermal noise in the cytoplasm and an additional external applied force. The motor-hopping rates are chosen to satisfy detailed balance with respect to the energy of stretching. The master equation is converted to a linear Fokker-Planck equation (LFPE), which yields the average positions of the cargo and motors, as well as their fluctuations and correlation functions. We apply this formalism to two specific forms of the hopping rates. Analytical results are obtained for mean cargo velocity, diffusion coefficient and the average force experienced by each motor for arbitrary N, and compared with numerical simulations. The expansion procedure also allows us to quantify load-sharing features among the cargo-bound motors. In general, we observe significant deviations between analytical predictions based on LFPE and the corresponding numerical results, which suggests a prominent role for higher order corrections.

  15. Multiscale approaches to protein-mediated interactions between membranes - Relating microscopic and macroscopic dynamics in radially growing adhesions

    E-Print Network [OSTI]

    Bihr, Timo; Smith, Ana-Suncana

    2015-01-01

    Macromolecular complexation leading to coupling of two or more cellular membranes is a crucial step in a number of biological functions of the cell. While other mechanisms may also play a role, adhesion always involves the fluctuations of deformable membranes, the diffusion of proteins and the molecular binding and unbinding. Because these stochastic processes couple over a multitude of time and length scales, theoretical modeling of membrane adhesion has been a major challenge. Here we present an effective Monte Carlo scheme within which the effects of the membrane are integrated into local rates for molecular recognition. The latter step in the Monte Carlo approach enables us to simulate the nucleation and growth of adhesion domains within a system of the size of a cell for tens of seconds without loss of accuracy, as shown by comparison to $10^6$ times more expensive Langevin simulations. To perform this validation, the Langevin approach was augmented to simulate diffusion of proteins explicitly, together ...

  16. Transport and Removal Mechanisms of Trace Organic Pollutants by Nanofiltration and Reverse Osmosis Membranes

    E-Print Network [OSTI]

    Wang, Jinwen

    2014-01-01

    solutions up to seawater salinity, Desalination, 184 (2005)Composite Seawater Reverse-Osmosis Membrane, Desalination,

  17. Transport and Removal Mechanisms of Trace Organic Pollutants by Nanofiltration and Reverse Osmosis Membranes

    E-Print Network [OSTI]

    Wang, Jinwen

    2014-01-01

    treatment technologies are needed. Membrane processes are now the primary separation technology used in wastewater

  18. Self-Assembly and Mass Transport in Membranes for Artificial Photosynthesis

    E-Print Network [OSTI]

    Modestino, Miguel Antonio

    2013-01-01

    for artificial photosynthesis systems ..6Artificial Photosynthesis up process of artificial photosynthesis membranes and open

  19. Insight from molecular modelling: does the polymer side chain length matter for transport properties of perfluorosulfonic acid membranes?

    SciTech Connect (OSTI)

    Devanathan, Ramaswami; Dupuis, Michel

    2012-08-28

    We present a detailed analysis of the nanostructure of short side chain (SSC) perfluorosulfonic acid membrane and its effect on H{sub 2}O network percolation, H{sub 3}O{sup +} and H{sub 2}O diffusion, and mean residence times of H{sub 3}O{sup +} and H{sub 2}O near SO{sub 3}{sup -} groups based on molecular dynamics simulations. We studied a range of hydration levels ({lambda}) at temperatures of 300 and 360 K, and compare the results to our previous findings in the benchmark Nafion membrane at 300 K. The water channel diameter is about 20% larger in Nafion, while the extent of SO3- clustering is more in SSC membrane. The calculated channel diameter is in excellent agreement with the recently proposed cylindrical water channel model of these membranes. The H{sub 2}O network percolation occurs at comparable hydration levels, and the diffusion coefficients of H{sub 2}O and H{sub 3}O{sup +} are similar in SSC and Nafion membranes. Raising the temperature of the SSC membrane from 300 to 360 K provides a much bigger increase in proton vehicular diffusion coefficient (by a factor of about 4) than changing the side chain length. H3O+ ions are found to exchange more frequently with SO{sub 3}{sup -} partners at the higher temperature. Our key findings are that (a) the hydrophobic-hydrophilic separation in the two membranes is surprisingly similar; (b) at all hydration levels studied, the longer side chain of Nafion is bent and is effectively equivalent to a short side chain in terms of extension into the water domain; and (c) proton transport along the centre of the channel is improbable and vehicular proton transport occurs between SO{sub 3}{sup -} groups. The simulations are validated by good agreement with corresponding experimental values for the simulated membrane density and diffusion coefficients of H{sub 2}O.

  20. Proton Transport by the Influenza M2 Protein Gregory S. Boebinger, National High Magnetic Field Laboratory

    E-Print Network [OSTI]

    Weston, Ken

    Proton Transport by the Influenza M2 Protein Gregory S. Boebinger, National High Magnetic Field infections) in native like lipid bilayers has allowed us to determine a novel mechanism for proton transport that has not been observed in any other protein. At the heart of this proton channel is a set of 4

  1. Smart membranes for nitrate removal, water purification, and selective ion transportation

    DOE Patents [OSTI]

    Wilson, William D. (Pleasanton, CA); Schaldach, Charlene M. (Pleasanton, CA); Bourcier, William L. (Livermore, CA); Paul, Phillip H. (Livermore, CA)

    2009-12-15

    A computer designed nanoengineered membrane for separation of dissolved species. One embodiment provides an apparatus for treatment of a fluid that includes ions comprising a microengineered porous membrane, a system for producing an electrical charge across the membrane, and a series of nanopores extending through the membrane. The nanopores have a pore size such that when the fluid contacts the membrane, the nanopores will be in a condition of double layer overlap and allow passage only of ions opposite to the electrical charge across the membrane.

  2. A protein chip membrane-capture assay for botulinum neurotoxin activity

    SciTech Connect (OSTI)

    Marconi, Severine; Ferracci, Geraldine; Berthomieu, Maelys; Kozaki, Shunji; Miquelis, Raymond; Boucraut, Jose; Seagar, Michael

    2008-12-15

    Botulinum neurotoxins A and B (BoNT/A and B) are neuromuscular blocking agents which inhibit neurotransmission by cleaving the intra-cellular presynaptic SNARE proteins SNAP-25 and VAMP2, localized respectively in plasma membrane and synaptic vesicles. These neurotoxins are both dangerous pathogens and powerful therapeutic agents with numerous clinical and cosmetic applications. Consequently there is a need for in vitro assays of their biological activity to screen for potential inhibitors and to replace the widely used in vivo mouse assay. Surface plasmon resonance (SPR) was used to measure membrane vesicle capture by antibodies against SNAP-25 and VAMP2. Substrate cleavage by BoNTs modified capture providing a method to assay toxin activity. Firstly using synaptic vesicles as a substrate, a comparison of the EC{sub 50}s for BoNT/B obtained by SPR, ELISA or flow cytometry indicated similar sensitivity although SPR assays were more rapid. Sonication of brain or neuronal cultures generated plasma membrane fragments with accessible intra-cellular epitopes adapted to measurement of BoNT/A activity. SPR responses were proportional to antigen concentration permitting detection of as little as 4 pM SNAP-25 in crude lysates. BoNT/A activity was assayed using monoclonal antibodies that specifically recognize a SNAP-25 epitope generated by the proteolytic action of the toxin. Incubation of intact primary cultured neurons with BoNT/A yielded an EC{sub 50} of 0.5 pM. The SPR biosensor method was sensitive enough to monitor BoNT/A and B activity in cells cultured in a 96-well format providing an alternative to experimental animals for toxicological assays.

  3. Self-Assembly and Mass Transport in Membranes for Artificial Photosynthesis

    E-Print Network [OSTI]

    Modestino, Miguel Antonio

    2013-01-01

    M. A. ; Pivovar, B. S. Fuel Cells 2005, 5, (2), 213-229.exchange membrane for fuel cells. University of California,exchange membrane for fuel cells. University of California,

  4. Integrated Atomic Force Microscopy Techniques for Analysis of Biomaterials : : Study of Membrane Proteins

    E-Print Network [OSTI]

    Connelly, Laura S.

    2014-01-01

    TECHNIQUES FOR ANALYSIS OF BIOMATERIALS: STUDY OF MEMBRANETECHNIQUES FOR ANALYSIS OF BIOMATERIALS: STUDY OF MEMBRANE

  5. Dynamics of Membrane Protein/Amphipol Association Studied by Forster Resonance Energy Transfer: Implications for in Vitro Studies of

    E-Print Network [OSTI]

    functions, including energy transduction, import and export of nutriments and drugs, assessmentDynamics of Membrane Protein/Amphipol Association Studied by Fo¨rster Resonance Energy Transfer¨rster resonance energy transfer measurements show that extensive dilution of tOmpA/A8-35 particles into an APol

  6. Metal-induced conformational changes in ZneB suggest an active role of membrane fusion proteins in

    E-Print Network [OSTI]

    Stroud, Robert

    Metal-induced conformational changes in ZneB suggest an active role of membrane fusion proteins division (RND)-based efflux complexes mediate multidrug and heavy-metal resistance in many Gram- negative the role of MFPs in RND-driven efflux systems, we chose ZneB, the MFP component of the ZneCAB heavy-metal

  7. Spectroscopic studies of tryptophan and membrane- associated peptides

    E-Print Network [OSTI]

    Schlamadinger, Diana Elizabeth

    2011-01-01

    Thermodynamics of membrane protein folding measured byThermodynamics of Membrane Protein Folding: Lessons from theKim, Thermodynamics of membrane protein folding measured by

  8. Shewanella oneidensis MR-1 Nanowires are Outer Membrane and Periplasmic Extensions of the Extracellular Electron Transport Components

    SciTech Connect (OSTI)

    Pirbadian, S.; Barchinger, S. E.; Leung, K. M.; Byun, H. S.; Jangir, Y.; Bouhenni, Rachida; Reed, Samantha B.; Romine, Margaret F.; Saffarini, Daad; Shi, Liang; Gorby, Yuri A.; Golbeck, J. H.; El-Naggar, Mohamed Y.

    2014-08-20

    Bacterial nanowires offer an extracellular electron transport (EET) pathway for linking the respiratory chain of bacteria to external surfaces, including oxidized metals in the environment and engineered electrodes in renewable energy devices. Despite the global, environmental, and technological consequences of this biotic-abiotic interaction, the composition, physiological relevance, and electron transport mechanisms of bacterial nanowires remain unclear. We report the first in vivo observations of the formation and respiratory impact of nanowires in the model metal-reducing microbe Shewanella neidensis MR-1. Using live fluorescence measurements, immunolabeling, and quantitative gene expression analysis, we report that S. oneidensis MR-1 nanowires are extensions of the outer membrane and periplasm that include the multiheme cytochromes responsible for EET, rather than pilin-based structures, as previously thought. These bacterial nanowires were also associated with outer membrane vesicles and vesicle chains, structures ubiquitous in gram-negative bacteria. Redoxfunctionalized membrane and vesicular extensions may represent a general microbial strategy for electron transport and energy distribution.

  9. Conceptual design report for a Direct Hydrogen Proton Exchange Membrane Fuel Cell for transportation application

    SciTech Connect (OSTI)

    NONE

    1995-09-05

    This report presents the conceptual design for a Direct-Hydrogen-Fueled Proton Exchange Membrane (PEM) Fuel Cell System for transportation applications. The design is based on the initial selection of the Chrysler LH sedan as the target vehicle with a 50 kW (gross) PEM Fuel Cell Stack (FCS) as the primary power source, a battery-powered Load Leveling Unit (LLU) for surge power requirements, an on-board hydrogen storage subsystem containing high pressure gaseous storage, a Gas Management Subsystem (GMS) to manage the hydrogen and air supplies for the FCS, and electronic controllers to control the electrical system. The design process has been dedicated to the use of Design-to-Cost (DTC) principles. The Direct Hydrogen-Powered PEM Fuel Cell Stack Hybrid Vehicle (DPHV) system is designed to operate on the Federal Urban Driving Schedule (FUDS) and Hiway Cycles. These cycles have been used to evaluate the vehicle performance with regard to range and hydrogen usage. The major constraints for the DPHV vehicle are vehicle and battery weight, transparency of the power system and drive train to the user, equivalence of fuel and life cycle costs to conventional vehicles, and vehicle range. The energy and power requirements are derived by the capability of the DPHV system to achieve an acceleration from 0 to 60 MPH within 12 seconds, and the capability to achieve and maintain a speed of 55 MPH on a grade of seven percent. The conceptual design for the DPHV vehicle is shown in a figure. A detailed description of the Hydrogen Storage Subsystem is given in section 4. A detailed description of the FCS Subsystem and GMS is given in section 3. A detailed description of the LLU, selection of the LLU energy source, and the power controller designs is given in section 5.

  10. Selective transport and packaging of the major yolk protein in the sea urchin

    E-Print Network [OSTI]

    Wessel, Gary M.

    Selective transport and packaging of the major yolk protein in the sea urchin Jacqueline M. Brooks of yolk transport, endocytosis, and packaging during the vitellogenic phase of oogenesis in the sea urchin of the ovary and its packaging into yolk platelets of developing oocytes is visualized in isolated oocytes

  11. Kinesin Motor Transport is Altered by Macromolecular Crowding and Transiently Associated Microtubule-Associated Proteins

    E-Print Network [OSTI]

    Ross, Jennifer

    01 Kinesin Motor Transport is Altered by Macromolecular Crowding and Transiently Associated of crowding and an increasingly complex cellular environment on the transport of individual motor proteins, we have performed in vitro reconstitution experiments with single kinesin-1 motors walking on microtubules

  12. Memprot: a program to model the detergent corona around a membrane protein based on SEC–SAXS data

    SciTech Connect (OSTI)

    Pérez, Javier, E-mail: javier.perez@synchrotron-soleil.fr [Synchrotron SOLEIL, L’Orme des Merisiers, BP 48, Saint-Aubin, 91192 Gif-sur-Yvette (France); Koutsioubas, Alexandros [Forschungszentrum Jülich GmbH, Outstation at MLZ, Lichtenbergstrasse 1, 85747 Garching (Germany); Synchrotron SOLEIL, L’Orme des Merisiers, BP 48, Saint-Aubin, 91192 Gif-sur-Yvette (France)

    2015-01-01

    Systematic SAXS simulations have been analysed over a wide range of parameters in order to better understand the detergent corona around a membrane protein. The application of small-angle X-ray scattering (SAXS) to structural investigations of transmembrane proteins in detergent solution has been hampered by two main inherent hurdles. On the one hand, the formation of a detergent corona around the hydrophobic region of the protein strongly modifies the scattering curve of the protein. On the other hand, free micelles of detergent without a precisely known concentration coexist with the protein–detergent complex in solution, therefore adding an uncontrolled signal. To gain robust structural information on such systems from SAXS data, in previous work, advantage was taken of the online combination of size-exclusion chromatography (SEC) and SAXS, and the detergent corona around aquaporin-0, a membrane protein of known structure, could be modelled. A precise geometrical model of the corona, shaped as an elliptical torus, was determined. Here, in order to better understand the correlations between the corona model parameters and to discuss the uniqueness of the model, this work was revisited by analyzing systematic SAXS simulations over a wide range of parameters of the torus.

  13. Sequencing proteins with transverse ionic transport in nanochannels

    E-Print Network [OSTI]

    Boynton, P

    2015-01-01

    {\\it De novo} protein sequencing is essential for understanding cellular processes that govern the function of living organisms and all post-translational events and other sequence modifications that occur after a protein has been constructed from its corresponding DNA code. By obtaining the order of the amino acids that composes a given protein one can then determine both its secondary and tertiary structures through structure prediction, which is used to create models for protein aggregation diseases such as Alzheimer's Disease. Mass spectrometry is the current technique of choice for {\\it de novo} sequencing. However, because some amino acids have the same mass the sequence cannot be completely determined in many cases. Here, we propose a new technique for {\\it de novo} protein sequencing that involves translocating a polypeptide through a synthetic nanochannel and measuring the ionic current of each amino acid through an intersecting {\\it perpendicular} nanochannel. To calculate the transverse ionic curre...

  14. Simple Host?Guest Chemistry To Modulate the Process of Concentration and Crystallization of Membrane Proteins by Detergent Capture in a Microfluidic Device

    SciTech Connect (OSTI)

    Li, Liang; Nachtergaele, Sigrid; Seddon, Annela M.; Tereshko, Valentina; Ponomarenko, Nina; Ismagilov, Rustem F. (UC)

    2009-01-15

    This paper utilizes cyclodextrin-based host-guest chemistry in a microfluidic device to modulate the crystallization of membrane proteins and the process of concentration of membrane protein samples. Methyl-{beta}-cyclodextrin (MBCD) can efficiently capture a wide variety of detergents commonly used for the stabilization of membrane proteins by sequestering detergent monomers. Reaction Center (RC) from Blastochloris viridis was used here as a model system. In the process of concentrating membrane protein samples, MBCD was shown to break up free detergent micelles and prevent them from being concentrated. The addition of an optimal amount of MBCD to the RC sample captured loosely bound detergent from the protein-detergent complex and improved sample homogeneity, as characterized by dynamic light scattering. Using plug-based microfluidics, RC crystals were grown in the presence of MBCD, giving a different morphology and space group than crystals grown without MBCD. The crystal structure of RC crystallized in the presence of MBCD was consistent with the changes in packing and crystal contacts hypothesized for removal of loosely bound detergent. The incorporation of MBCD into a plug-based microfluidic crystallization method allows efficient use of limited membrane protein sample by reducing the amount of protein required and combining sparse matrix screening and optimization in one experiment. The use of MBCD for detergent capture can be expanded to develop cyclodextrin-derived molecules for fine-tuned detergent capture and thus modulate membrane protein crystallization in an even more controllable way.

  15. Spatially resolved in situ measurements of the transport of organic molecules in a polycrystalline nanoporous membrane

    E-Print Network [OSTI]

    Nair, Sankar

    of photoacoustic signal generation from a heterogeneous membrane, allows extraction of concentration profiles and converted into a thermoacoustic signal originating from a cumulative region of the sample down to a certain

  16. The effect of adjacent layers like biofilms on mass transport through nanofiltration membranes

    E-Print Network [OSTI]

    Bothe, Dieter

    , which is always present on the membrane surface in crossflow filtration processes, as well as a feed to high tangential flow velocities in crossflow filtrations, the size of this biofilm is limited to values

  17. Investigation of the performance and water transport of a polymer electrolyte membrane (pem) fuel cell 

    E-Print Network [OSTI]

    Park, Yong Hun

    2009-05-15

    Fuel cell performance was obtained as functions of the humidity at the anode and cathode sites, back pressure, flow rate, temperature, and channel depth. The fuel cell used in this work included a membrane and electrode assembly (MEA) which...

  18. ENGINEERING DEVELOPMENT OF CERAMIC MEMBRANE REACTOR SYSTEM FOR CONVERTING NATURAL GAS TO HYDROGEN AND SYNTHESIS GAS FOR LIQUID TRANSPORTATION FUELS

    SciTech Connect (OSTI)

    NONE

    1998-08-01

    The objective of this contract is to research, develop and demonstrate a novel ceramic membrane reactor system for the low-cost conversion of natural gas to synthesis gas and hydrogen for liquid transportation fuels: the ITM Syngas process. Through an eight-year, three-phase program, the technology will be developed and scaled up to obtain the technical, engineering, operating and economic data necessary for the final step to full commercialization of the Gas-to-Liquids (GTL) conversion technology. This report is a summary of activities through July 1999.

  19. Engineering development of ceramic membrane reactor system for converting natural gas to hydrogen and synthesis gas for liquid transportation fuels

    SciTech Connect (OSTI)

    NONE

    1998-07-01

    The objective of this contract is to research, develop and demonstrate a novel ceramic membrane reactor system for the low-cost conversion of natural gas to synthesis gas and hydrogen for liquid transportation fuels: the ITM Syngas process. Through an eight-year, three-phase program, the technology will be developed and scaled up to obtain the technical, engineering, operating and economic data necessary for the final step to full commercialization of the Gas-to-Liquids (GTL) conversion technology. This report is a summary of activities through June 1998.

  20. ENGINEERING DEVELOPMENT OF CERAMIC MEMBRANE REACTOR SYSTEM FOR CONVERTING NATURAL GAS TO HYDROGEN AND SYNTHESIS GAS FOR LIQUID TRANSPORTATION FUELS

    SciTech Connect (OSTI)

    NONE

    1999-12-01

    The objective of this contract is to research, develop and demonstrate a novel ceramic membrane reactor system for the low-cost conversion of natural gas to synthesis gas and hydrogen for liquid transportation fuels: the ITM Syngas process. Through an eight-year, three-phase program, the technology will be developed and scaled up to obtain the technical, engineering, operating and economic data necessary for the final step to full commercialization of the Gas-to-Liquids (GTL) conversion technology. This report is a summary of activities through November 1999.

  1. ENGINEERING DEVELOPMENT OF CERAMIC MEMBRANE REACTOR SYSTEM FOR CONVERTING NATURAL GAS TO HYDROGEN AND SYNTHESIS GAS FOR LIQUID TRANSPORTATION FUELS

    SciTech Connect (OSTI)

    NONE

    1999-03-01

    The objective of this contract is to research, develop and demonstrate a novel ceramic membrane reactor system for the low-cost conversion of natural gas to synthesis gas and hydrogen for liquid transportation fuels: the ITM Syngas process. Through an eight-year, three-phase program, the technology will be developed and scaled up to obtain the technical, engineering, operating and economic data necessary for the final step to full commercialization of the Gas-to-Liquids (GTL) conversion technology. This report is a summary of activities through February 1999.

  2. Engineering development of ceramic membrane reactor system for converting natural gas to hydrogen and synthesis gas for liquid transportation fuels

    SciTech Connect (OSTI)

    NONE

    1998-05-01

    The objective of this contract is to research, develop and demonstrate a novel ceramic membrane reactor system for the low-cost conversion of natural gas to synthesis gas and hydrogen for liquid transportation fuels: the ITM Syngas process. Through an eight-year, three-phase program, the technology will be developed and scaled up to obtain the technical, engineering, operating and economic data necessary for the final step to full commercialization of the Gas-to-Liquids (GTL) conversion technology. This report is a summary of activities through April 1998.

  3. ENGINEERING DEVELOPMENT OF CERAMIC MEMBRANE REACTOR SYSTEM FOR CONVERTING NATURAL GAS TO HYDROGEN AND SYNTHESIS GAS FOR LIQUID TRANSPORTATION FUELS

    SciTech Connect (OSTI)

    NONE

    1999-10-01

    The objective of this contract is to research, develop and demonstrate a novel ceramic membrane reactor system for the low-cost conversion of natural gas to synthesis gas and hydrogen for liquid transportation fuels: the ITM Syngas process. Through an eight-year, three-phase program, the technology will be developed and scaled up to obtain the technical, engineering, operating and economic data necessary for the final step to full commercialization of the Gas-to-Liquids (GTL) conversion technology. This report is a summary of activities through September 1999.

  4. ENGINEERING DEVELOPMENT OF CERAMIC MEMBRANE REACTOR SYSTEM FOR CONVERTING NATURAL GAS TO HYDROGEN AND SYNTHESIS GAS FOR LIQUID TRANSPORTATION FUELS

    SciTech Connect (OSTI)

    NONE

    2000-02-01

    The objective of this contract is to research, develop and demonstrate a novel ceramic membrane reactor system for the low-cost conversion of natural gas to synthesis gas and hydrogen for liquid transportation fuels: the ITM Syngas process. Through an eight-year, three-phase program, the technology will be developed and scaled up to obtain the technical, engineering, operating and economic data necessary for the final step to full commercialization of the Gas-to-Liquids (GTL) conversion technology. This report is a summary of activities through January 2000.

  5. ENGINEERING DEVELOPMENT OF CERAMIC MEMBRANE REACTOR SYSTEM FOR CONVERTING NATURAL GAS TO HYDROGEN AND SYNTHESIS GAS FOR LIQUID TRANSPORTATION FUELS

    SciTech Connect (OSTI)

    NONE

    2000-01-01

    The objective of this contract is to research, develop and demonstrate a novel ceramic membrane reactor system for the low-cost conversion of natural gas to synthesis gas and hydrogen for liquid transportation fuels: the ITM Syngas process. Through an eight-year, three-phase program, the technology will be developed and scaled up to obtain the technical, engineering, operating and economic data necessary for the final step to full commercialization of the Gas-to-Liquids (GTL) conversion technology. This report is a summary of activities through December 1999.

  6. ENGINEERING DEVELOPMENT OF CERAMIC MEMBRANE REACTOR SYSTEM FOR CONVERTING NATURAL GAS TO HYDROGEN AND SYNTHESIS GAS FOR LIQUID TRANSPORTATION FUELS

    SciTech Connect (OSTI)

    NONE

    1999-11-01

    The objective of this contract is to research, develop and demonstrate a novel ceramic membrane reactor system for the low-cost conversion of natural gas to synthesis gas and hydrogen for liquid transportation fuels: the ITM Syngas process. Through an eight-year, three-phase program, the technology will be developed and scaled up to obtain the technical, engineering, operating and economic data necessary for the final step to full commercialization of the Gas-to-Liquids (GTL) conversion technology. This report is a summary of activities through October 1999.

  7. Amphipathic Polymers: Tools To Fold Integral Membrane Proteins to Their Active Form

    E-Print Network [OSTI]

    Kleinschmidt, Jörg H.

    , Institut de Biologie Physico-Chimique, CNRS FRC 550, 13 rue Pierre et Marie Curie, F-75005 Paris, France, and bacteriorhodopsin, a light-driven proton pump from the plasma membrane of the archaebacterium Halobacterium. Schematically, heterologously expressed MPs targeted to the plasma membrane tend to kill their host, limiting

  8. Application of Polyurethane Thin Films and Membranes for MALDI-MS of Proteins and Glycoproteins

    E-Print Network [OSTI]

    Ens, Werner

    by dissolving PU membrane in THF followed by casting on ca. 1 cm diameter Al disks. The membranes were supports while some effort was made to acquire good quality mass spectra with the metal targets. Samples prepared on the metal targets without washing did not produce mass spectra. Figure 1 shows MALDI mass

  9. Nanowire-integrated microporous silicon membrane for continuous fluid transport in micro cooling device

    SciTech Connect (OSTI)

    So, Hongyun; Pisano, Albert P.; Cheng, Jim C.

    2013-10-14

    We report an efficient passive micro pump system combining the physical properties of nanowires and micropores. This nanowire-integrated microporous silicon membrane was created to feed coolant continuously onto the surface of the wick in a micro cooling device to ensure it remains hydrated and in case of dryout, allow for regeneration of the system. The membrane was fabricated by photoelectrochemical etching to form micropores followed by hydrothermal growth of nanowires. This study shows a promising approach to address thermal management challenges for next generation electronic devices with absence of external power.

  10. Super Boiler: Packed Media/Transport Membrane Boiler Development and Demonstration

    SciTech Connect (OSTI)

    Liss, William E; Cygan, David F

    2013-04-17

    Gas Technology Institute (GTI) and Cleaver-Brooks developed a new gas-fired steam generation system���¢��������the Super Boiler���¢��������for increased energy efficiency, reduced equipment size, and reduced emissions. The system consists of a firetube boiler with a unique staged furnace design, a two-stage burner system with engineered internal recirculation and inter-stage cooling integral to the boiler, unique convective pass design with extended internal surfaces for enhanced heat transfer, and a novel integrated heat recovery system to extract maximum energy from the flue gas. With these combined innovations, the Super Boiler technical goals were set at 94% HHV fuel efficiency, operation on natural gas with <5 ppmv NOx (referenced to 3%O2), and 50% smaller than conventional boilers of similar steam output. To demonstrate these technical goals, the project culminated in the industrial demonstration of this new high-efficiency technology on a 300 HP boiler at Clement Pappas, a juice bottler located in Ontario, California. The Super Boiler combustion system is based on two stage combustion which combines air staging, internal flue gas recirculation, inter-stage cooling, and unique fuel-air mixing technology to achieve low emissions rather than external flue gas recirculation which is most commonly used today. The two-stage combustion provides lower emissions because of the integrated design of the boiler and combustion system which permit precise control of peak flame temperatures in both primary and secondary stages of combustion. To reduce equipment size, the Super Boiler's dual furnace design increases radiant heat transfer to the furnace walls, allowing shorter overall furnace length, and also employs convective tubes with extended surfaces that increase heat transfer by up to 18-fold compared to conventional bare tubes. In this way, a two-pass boiler can achieve the same efficiency as a traditional three or four-pass firetube boiler design. The Super Boiler is consequently up to 50% smaller in footprint, has a smaller diameter, and is up to 50% lower in weight, resulting in very compact design with reduced material cost and labor costs, while requiring less boiler room floor space. For enhanced energy efficiency, the heat recovery system uses a transport membrane condenser (TMC), a humidifying air heater (HAH), and a split-stage economizer to extract maximum energy from the flue gas. The TMC is a new innovation that pulls a major portion of water vapor produced by the combustion process from the flue gases along with its sensible and latent heat. This results in nearly 100% transfer of heat to the boiler feed water. The HAH improves the effectiveness of the TMC, particularly in steam systems that do not have a large amount of cold makeup water. In addition, the HAH humidifies the combustion air to reduce NOx formation. The split-stage economizer preheats boiler feed water in the same way as a conventional economizer, but extracts more heat by working in tandem with the TMC and HAH to reduce flue gas temperature. These components are designed to work synergistically to achieve energy efficiencies of 92-94% which is 10-15% higher than today���¢��������s typical firetube boilers.

  11. Modelling of morphology and proton transport in PFSA membranes James A. Elliotta

    E-Print Network [OSTI]

    Elliott, James

    mechanisms and the need to examine the chemical and physical processes at several distinct time and length with which to guide the process of designing novel membrane materials for fuel cell applications synthesized by the Dow Chemical Company,6­8 but more recently by Solvay- Solexis9­11 as Hyflons ) continue

  12. Microstructure orientation and nanoporous gas transport in semicrystalline block copolymer membranes

    E-Print Network [OSTI]

    Rubloff, Gary W.

    27 August 1999; accepted 30 August 1999 Abstract Gas permeability coefficients were obtained for CO2 properties has resulted in a variety of applications for high throughput membrane materials and low and He gases at room temperature in a semicrystalline ethylene/ethylene­propylene/ ethylene (E

  13. Effect of protein shape on multibody interactions between membrane inclusions K. S. Kim,1,

    E-Print Network [OSTI]

    Oster, George

    for a membrane is given by 11 Em X B 2 S 2 h x 2 dx 2B S 2 dx, 1 where B is the bending modulus. We neglect prop- erties of the membrane. In an earlier paper 7 , we examined the deformation field generated(x) 1, the local mean curvature of S at X x z3 is (x) 1 2 2 h(x). The elastic bending energy

  14. Lipid transport mediated by Arabidopsis TGD proteins is unidirectional from the endoplasmic reticulum to the plastid

    SciTech Connect (OSTI)

    Xu, C.; Moellering, E. R., Muthan, B.; Fan, J.; Benning, C.

    2010-06-01

    The transfer of lipids between the endoplasmic reticulum (ER) and the plastid in Arabidopsis involves the TRIGALACTOSYLDIACYLGLYCEROL (TGD) proteins. Lipid exchange is thought to be bidirectional based on the presence of specific lipid molecular species in Arabidopsis mutants impaired in the desaturation of fatty acids of membrane lipids in the ER and plastid. However, it was unclear whether TGD proteins were required for lipid trafficking in both directions. This question was addressed through the analysis of double mutants of tgd1-1 or tgd4-3 in genetic mutant backgrounds leading to a defect in lipid fatty acid desaturation either in the ER (fad2) or the plastid (fad6). The fad6 tgd1-1 and fad6 tgd4-3 double mutants showed drastic reductions in the relative levels of polyunsaturated fatty acids and of galactolipids. The growth of these plants and the development of photosynthetic membrane systems were severely compromised, suggesting a disruption in the import of polyunsaturated fatty acid-containing lipid species from the ER. Furthermore, a forward-genetic screen in the tgd1-2 dgd1 mutant background led to the isolation of a new fad6-2 allele with a marked reduction in the amount of digalactosyldiacylglycerol. In contrast, the introduction of fad2, affecting fatty acid desaturation of lipids in the ER, into the two tgd mutant backgrounds did not further decrease the level of fatty acid desaturation in lipids of extraplastidic membranes. These results suggest that the role of TGD proteins is limited to plastid lipid import, but does not extend to lipid export from the plastid to extraplastidic membranes.

  15. Mapping the energy and diffusion landscapes of membrane proteins at the cell surface using high-density single-molecule imaging and Bayesian inference: application to the multi-scale dynamics of glycine receptors in the neuronal membrane

    E-Print Network [OSTI]

    Masson, Jean-Baptiste; Salvatico, Charlotte; Renner, Marianne; Specht, Christian G; Triller, Antoine; Dahan, Maxime

    2015-01-01

    Protein mobility is conventionally analyzed in terms of an effective diffusion. Yet, this description often fails to properly distinguish and evaluate the physical parameters (such as the membrane friction) and the biochemical interactions governing the motion. Here, we present a method combining high-density single-molecule imaging and statistical inference to separately map the diffusion and energy landscapes of membrane proteins across the cell surface at ~100 nm resolution (with acquisition of a few minutes). When applying these analytical tools to glycine neurotransmitter receptors (GlyRs) at inhibitory synapses, we find that gephyrin scaffolds act as shallow energy traps (~3 kBT) for GlyRs, with a depth modulated by the biochemical properties of the receptor-gephyrin interaction loop. In turn, the inferred maps can be used to simulate the dynamics of proteins in the membrane, from the level of individual receptors to that of the population, and thereby, to model the stochastic fluctuations of physiologi...

  16. Rapid Impedance Measurement of Tethered Bilayer Lipid Membrane Biosensors

    E-Print Network [OSTI]

    Mason, Andrew

    Rapid Impedance Measurement of Tethered Bilayer Lipid Membrane Biosensors Xiaoyi Mu, Daniel Rairigh of millisecond membrane protein activity in biosensor arrays. I. INTRODUCTION Because of the critical role membrane proteins play in biological function, biosensors utilizing membrane proteins have become

  17. High-Order Membrane Complexes from Activated G-Protein Subunits

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    inhibit the activity of the G proteins. A joint University of Michigan-University of Illinois, Chicago, team has determined the first structure of a particular G-protein-GRK2...

  18. Comparison of soy protein concentrates produced by membrane filtration and acid precipitation 

    E-Print Network [OSTI]

    Kim, Hyun Jung

    2003-01-01

    The recovery of proteins using ultrafiltration (UF) process is an attractive alternative compared to conventional acid precipitation method. The mild processing condition, which leads to less protein denaturation, may be ...

  19. Investigation of molecular mechanisms of action of chelating drugs on protein-lipid model membranes by X-ray fluorescence

    SciTech Connect (OSTI)

    Novikova, N. N., E-mail: nn_novikova@ns.crys.ras.ru [Kurchatov Institute, Russian Research Center (Russian Federation); Zheludeva, S. I.; Koval'chuk, M. V.; Stepina, N. D. [Russian Academy of Sciences, Shubnikov Institute of Crystallography (Russian Federation); Erko, A. I. [Berlin Electron Storage Ring Company for Synchrotron Radiation (Germany); Yur'eva, E. A. [Ministry of Health of the Russian Federation, Moscow Research Institute of Pediatrics and Pediatric Surgery (Russian Federation)

    2009-12-15

    Protein-lipid films based on the enzyme alkaline phosphatase were subjected to the action of chelating drugs, which are used for accelerating the removal of heavy metals from the human body, and the elemental composition of the resulting films was investigated. Total-reflection X-ray fluorescence measurements were performed at the Berlin Electron Storage Ring Company for Synchrotron Radiation (BESSY) in Germany. A comparative estimation of the protective effect of four drugs (EDTA, succimer, xydiphone, and mediphon) on membrane-bound enzymes damaged by lead ions was made. The changes in the elemental composition of the protein-lipid films caused by high doses of chelating drugs were investigated. It was shown that state-of-the-art X-ray techniques can, in principle, be used to develop new methods for the in vitro evaluation of the efficiency of drugs, providing differential data on their actions.

  20. Molecular Mechanism of Biological Proton Transport

    SciTech Connect (OSTI)

    Pomes, R.

    1998-09-01

    Proton transport across lipid membranes is a fundamental aspect of biological energy transduction (metabolism). This function is mediated by a Grotthuss mechanism involving proton hopping along hydrogen-bonded networks embedded in membrane-spanning proteins. Using molecular simulations, the authors have explored the structural, dynamic, and thermodynamic properties giving rise to long-range proton translocation in hydrogen-bonded networks involving water molecules, or water wires, which are emerging as ubiquitous H{sup +}-transport devices in biological systems.

  1. Systematic Identification and Characterization of Novel Human Skin-Associated Genes Encoding Membrane and Secreted Proteins

    E-Print Network [OSTI]

    2013-01-01

    survey: psoriasis vulgaris (PSO), atopic dermatitis (AD),upregulated significantly in PSO, followed by AK and AD (a proinflammatory protein. PSO represents one of the major

  2. Crystallization and preliminary X-ray diffraction analysis of YidC, a membrane-protein chaperone and insertase from Bacillus halodurans

    SciTech Connect (OSTI)

    Kumazaki, Kaoru [The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan); RIKEN, 2-1 Hirosawa, Wako-shi, Saitama 351-0198 (Japan); Tsukazaki, Tomoya, E-mail: ttsukaza@bs.naist.jp [Nara Institute of Science and Technology, 8916-5 Takayama-cho, Ikoma-shi, Nara 630-0192 (Japan); PRESTO, 4-1-8 Honcho, Kawaguchi, Saitama 332-0012 (Japan); Nishizawa, Tomohiro [The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan); RIKEN, 2-1 Hirosawa, Wako-shi, Saitama 351-0198 (Japan); Tanaka, Yoshiki [Nara Institute of Science and Technology, 8916-5 Takayama-cho, Ikoma-shi, Nara 630-0192 (Japan); Kato, Hideaki E. [Stanford University, Stanford, CA 94305 (United States); Nakada-Nakura, Yoshiko [Kyoto University, Yoshidakonoe-cho, Sakyo-ku, Kyoto 606-8501 (Japan); Hirata, Kunio [RIKEN SPring-8 Center, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5148 (Japan); Mori, Yoshihiro; Suga, Hiroaki [The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan); Dohmae, Naoshi [RIKEN, 2-1 Hirosawa, Wako-shi, Saitama 351-0198 (Japan); Ishitani, Ryuichiro; Nureki, Osamu, E-mail: ttsukaza@bs.naist.jp [The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan); RIKEN, 2-1 Hirosawa, Wako-shi, Saitama 351-0198 (Japan)

    2014-07-23

    YidC, a membrane-protein chaperone/insertase from B. halodurans, was expressed, purified and crystallized in the lipidic cubic phase. An X-ray diffraction data set was collected to 2.4 Å resolution. YidC, a member of the YidC/Oxa1/Alb3 family, inserts proteins into the membrane and facilitates membrane-protein folding in bacteria. YidC plays key roles in both Sec-mediated integration and Sec-independent insertion of membrane proteins. Here, Bacillus halodurans YidC2, which has five transmembrane helices conserved among the other family members, was identified as a target protein for structure determination by a fluorescent size-exclusion chromatography analysis. The protein was overexpressed, purified and crystallized in the lipidic cubic phase. The crystals diffracted X-rays to 2.4 Å resolution and belonged to space group P2{sub 1}, with unit-cell parameters a = 43.9, b = 60.6, c = 58.9 Å, ? = 100.3°. The experimental phases were determined by the multiwavelength anomalous diffraction method using a mercury-derivatized crystal.

  3. Folding amphipathic helices into membranes: Amphiphilicity trumps hydrophobicity

    E-Print Network [OSTI]

    Fernández-Vidal, Mónica; Jayasinghe, Sajith; Ladokhin, Alexey S; White, Stephen H

    2007-01-01

    C. (1999). Membrane protein folding and stability: PhysicalA. S. & Hristova, K. (1998). Protein folding in membranes:Mutational analysis of protein folding and stability. In

  4. Structures and Transport Properties of Hydrated Water-Soluble Dendrimer-Grafted Polymer Membranes for Application to Polymer Electrolyte Membrane Fuel Cells

    E-Print Network [OSTI]

    Goddard III, William A.

    for application to polymer electrolyte membrane fuel cells (PEMFC). Using full-atomistic molecular dynamics materials for polymer electrolyte membrane fuel cells (PEMFC).1-6 This has led to a number of new materials or above). Recently, we proposed a strategy for improving the perfor- mance of PEMFC by utilizing

  5. A comprehensive review of the lipid cubic phase or in meso method for crystallizing membrane and soluble proteins and complexes

    SciTech Connect (OSTI)

    Caffrey, Martin, E-mail: martin.caffrey@tcd.ie [Trinity College Dublin, Dublin (Ireland)

    2015-01-01

    A comprehensive and up-to-date review of the lipid cubic phase or in meso method for crystallizing membrane and soluble proteins and complexes is reported. Recent applications of the method for in situ serial crystallography at X-ray free-electron lasers and synchrotrons are described. The lipid cubic phase or in meso method is a robust approach for crystallizing membrane proteins for structure determination. The uptake of the method is such that it is experiencing what can only be described as explosive growth. This timely, comprehensive and up-to-date review introduces the reader to the practice of in meso crystallogenesis, to the associated challenges and to their solutions. A model of how crystallization comes about mechanistically is presented for a more rational approach to crystallization. The possible involvement of the lamellar and inverted hexagonal phases in crystallogenesis and the application of the method to water-soluble, monotopic and lipid-anchored proteins are addressed. How to set up trials manually and automatically with a robot is introduced with reference to open-access online videos that provide a practical guide to all aspects of the method. These range from protein reconstitution to crystal harvesting from the hosting mesophase, which is noted for its viscosity and stickiness. The sponge phase, as an alternative medium in which to perform crystallization, is described. The compatibility of the method with additive lipids, detergents, precipitant-screen components and materials carried along with the protein such as denaturants and reducing agents is considered. The powerful host and additive lipid-screening strategies are described along with how samples that have low protein concentration and cell-free expressed protein can be used. Assaying the protein reconstituted in the bilayer of the cubic phase for function is an important element of quality control and is detailed. Host lipid design for crystallization at low temperatures and for large proteins and complexes is outlined. Experimental phasing by heavy-atom derivatization, soaking or co-crystallization is routine and the approaches that have been implemented to date are described. An overview and a breakdown by family and function of the close to 200 published structures that have been obtained using in meso-grown crystals are given. Recommendations for conducting the screening process to give a more productive outcome are summarized. The fact that the in meso method also works with soluble proteins should not be overlooked. Recent applications of the method for in situ serial crystallography at X-ray free-electron lasers and synchrotrons are described. The review ends with a view to the future and to the bright prospects for the method, which continues to contribute to our understanding of the molecular mechanisms of some of nature’s most valued proteinaceous robots.

  6. Salinity tolerance in plants: attempts to manipulate ion transport

    E-Print Network [OSTI]

    Vadim Volkov

    2014-11-06

    Ion transport is the major determining factor of salinity tolerance in plants. A simple scheme of a plant cell with ion fluxes provides basic understanding of ion transport and the corresponding changes of ion concentrations under salinity. The review describes in detail basic principles of ion transport for a plant cell, introduces set of transporters essential for sodium and potassium uptake and efflux, analyses driving forces of ion transport and compares ion fluxes measured by several techniques. Study of differences in ion transport between salt tolerant halophytes and salt-sensitive plants with an emphasis on transport of potassium and sodium via plasma membranes offers knowledge for increasing salinity tolerance. Effects of salt stress on ion transport properties of membranes show huge opportunities for manipulating ion transport. Several attempts to overexpress or knockout ion transporters for changing salinity tolerance are described. Future perspectives are questioned with more attention given to potential candidate ion channels and transporters for altered expression. The potential direction of increasing salinity tolerance by modifying ion channels and transporters is discussed and questioned. An alternative approach from synthetic biology is to modify the existing membrane transport proteins or create new ones with desired properties for transforming agricultural crops. The approach had not been widely used earlier and leads also to theoretical and pure scientific aspects of protein chemistry, structure-function relations of membrane proteins, systems biology and physiology of stress and ion homeostasis.

  7. The Metal-dependent Function of C2?: A Conditional Membrane Domain from Protein Kinase C? 

    E-Print Network [OSTI]

    Morales-Rivera, Krystal A.

    2013-11-26

    Protein Kinase C (PKC) isoforms function in signaling pathways responsible for controlling cell proliferation, survival and apoptosis. Up or down-regulation of PKCs has been implicated in cancer progression, cardiovascular ...

  8. Nonionic Homopolymeric Amphipols: Application to Membrane Protein Folding, Cell-Free Synthesis, and Solution Nuclear Magnetic

    E-Print Network [OSTI]

    here with BR and with the ghrelin G protein-coupled receptor GHS-R1a, thus extending the range (reviewed in ref 3) and modeled by molecular dynamics simulation.5 While it is by far the best

  9. Structural Insights into Membrane Targeting by the Flagellar Calcium-binding Protein (FCaBP) a Myristoylated and Palmitoylated Calcium Sensor in Trypanosoma cruzi

    SciTech Connect (OSTI)

    J Wingard; J Ladner; M Vanarotti; A Fisher; H Robinson; K Buchanan; D Engman; J Ames

    2011-12-31

    The flagellar calcium-binding protein (FCaBP) of the protozoan Trypanosoma cruzi is targeted to the flagellar membrane where it regulates flagellar function and assembly. As a first step toward understanding the Ca{sup 2+}-induced conformational changes important for membrane-targeting, we report here the x-ray crystal structure of FCaBP in the Ca{sup 2+}-free state determined at 2.2{angstrom} resolution. The first 17 residues from the N terminus appear unstructured and solvent-exposed. Residues implicated in membrane targeting (Lys-19, Lys-22, and Lys-25) are flanked by an exposed N-terminal helix (residues 26-37), forming a patch of positive charge on the protein surface that may interact electrostatically with flagellar membrane targets. The four EF-hands in FCaBP each adopt a 'closed conformation' similar to that seen in Ca{sup 2+}-free calmodulin. The overall fold of FCaBP is closest to that of grancalcin and other members of the penta EF-hand superfamily. Unlike the dimeric penta EF-hand proteins, FCaBP lacks a fifth EF-hand and is monomeric. The unstructured N-terminal region of FCaBP suggests that its covalently attached myristoyl group at the N terminus may be solvent-exposed, in contrast to the highly sequestered myristoyl group seen in recoverin and GCAP1. NMR analysis demonstrates that the myristoyl group attached to FCaBP is indeed solvent-exposed in both the Ca{sup 2+}-free and Ca{sup 2+}-bound states, and myristoylation has no effect on protein structure and folding stability. We propose that exposed acyl groups at the N terminus may anchor FCaBP to the flagellar membrane and that Ca{sup 2+}-induced conformational changes may control its binding to membrane-bound protein targets..

  10. VOLUME 80, NUMBER 20 P H Y S I C A L R E V I E W L E T T E R S 18 MAY 1998 Spontaneous Onset of Coherence and Energy Storage by Membrane Transporters

    E-Print Network [OSTI]

    Derényi, Imre

    of Coherence and Energy Storage by Membrane Transporters in an RLC Electric Circuit Imre Derényi and R. Dean equilibrium the energy flow can be reversed, i.e., power can flow from the downhill transport process that oscillating or fluctuating electric fields can drive thermodynami- cally uphill transport of ions catalyzed

  11. Operation of staged membrane oxidation reactor systems

    DOE Patents [OSTI]

    Repasky, John Michael

    2012-10-16

    A method of operating a multi-stage ion transport membrane oxidation system. The method comprises providing a multi-stage ion transport membrane oxidation system with at least a first membrane oxidation stage and a second membrane oxidation stage, operating the ion transport membrane oxidation system at operating conditions including a characteristic temperature of the first membrane oxidation stage and a characteristic temperature of the second membrane oxidation stage; and controlling the production capacity and/or the product quality by changing the characteristic temperature of the first membrane oxidation stage and/or changing the characteristic temperature of the second membrane oxidation stage.

  12. Temperature-Dependent Simulations of Dry Gas Transport in the Electrodes of Proton Exchange Membrane Fuel Cells

    E-Print Network [OSTI]

    Stockie, John

    Membrane Fuel Cells M. J. Kermani1 J. M. Stockie2 mkermani@unb.ca stockie@unb.ca 1 Post Doctoral Fellow the cathode of a proton exchange membrane (PEM) fuel cell is studied numerically. The di usion to achieve this goal is via proton exchange mem- brane (PEM) fuel cells, which in principle combine oxygen

  13. Nanoscale study of reactive transport in catalyst layer of proton exchange membrane fuel cells with precious and non-precious catalysts using lattice Boltzmann method

    E-Print Network [OSTI]

    Chen, Li; Kang, Qinjun; Holby, Edward F; Tao, Wen-Quan

    2014-01-01

    High-resolution porous structures of catalyst layer (CL) with multicomponent in proton exchange membrane fuel cells are reconstructed using a reconstruction method called quartet structure generation set. Characterization analyses of nanoscale structures are implemented including pore size distribution, specific area and phase connectivity. Pore-scale simulation methods based on the lattice Boltzmann method are developed and used to predict the macroscopic transport properties including effective diffusivity and proton conductivity. Nonuniform distributions of ionomer in CL generates more tortuous pathway for reactant transport and greatly reduces the effective diffusivity. Tortuosity of CL is much higher than conventional Bruggeman equation adopted. Knudsen diffusion plays a significant role in oxygen diffusion and significantly reduces the effective diffusivity. Reactive transport inside the CL is also investigated. Although the reactive surface area of non-precious metal catalyst (NPMC) CL is much higher t...

  14. Molecular modeling of the morphology and transport properties of two direct methanol fuel cell membranes: phenylated sulfonated poly(ether ether ketone ketone) versus Nafion

    SciTech Connect (OSTI)

    Devanathan, Ramaswami; Idupulapati, Nagesh B.; Dupuis, Michel

    2012-08-14

    We have used molecular dynamics simulations to examine membrane morphology and the transport of water, methanol and hydronium in phenylated sulfonated poly ether ether ketone ketone (Ph-SPEEKK) and Nafion membranes at 360 K for a range of hydration levels. At comparable hydration levels, the pore diameter is smaller, the sulfonate groups are more closely packed, the hydronium ions are more strongly bound to sulfonate groups, and the diffusion of water and hydronium is slower in Ph-SPEEKK relative to the corresponding properties in Nafion. The aromatic carbon backbone of Ph-SPEEKK is less hydrophobic than the fluorocarbon backbone of Nafion. Water network percolation occurs at a hydration level ({lambda}) of {approx}8 H{sub 2}O/SO{sub 3}{sup -}. At {lambda} = 20, water, methanol and hydronium diffusion coefficients were 1.4 x 10{sup -5}, 0.6 x 10{sup -5} and 0.2 x 10{sup -5} cm{sup 2}/s, respectively. The pore network in Ph-SPEEKK evolves dynamically and develops wide pores for {lambda} > 20, which leads to a jump in methanol crossover and ion transport. This study demonstrates the potential of aromatic membranes as low-cost challengers to Nafion for direct methanol fuel cell applications and the need to develop innovative strategies to combat methanol crossover at high hydration levels.

  15. Targeted Protein Degradation of Outer Membrane Decaheme Cytochrome MtrC Metal Reductase in Shewanella oneidensis MR-1 Measured Using Biarsenical Probe CrAsH-EDT2

    SciTech Connect (OSTI)

    Xiong, Yijia; Chen, Baowei; Shi, Liang; Fredrickson, Jim K.; Bigelow, Diana J.; Squier, Thomas C.

    2011-10-14

    Development of efficient microbial biofuel cells requires an ability to exploit interfacial electron transfer reactions to external electron acceptors, such as metal oxides; such reactions occur in the facultative anaerobic gram-negative bacterium Shewanella oneidensis MR-1 through the catalytic activity of the outer membrane decaheme c-type cytochrome MtrC. Central to the utility of this pathway to synthetic biology is an understanding of cellular mechanisms that maintain optimal MtrC function, cellular localization, and renewal by degradation and resynthesis. In order to monitor trafficking to the outer membrane, and the environmental sensitivity of MtrC, we have engineered a tetracysteine tag (i.e., CCPGCC) at its C-terminus that permits labeling by the cell impermeable biarsenical fluorophore, carboxy-FlAsH (CrAsH) of MtrC at the surface of living Shewanella oneidensis MR-1 cells. In comparison, the cell permeable reagent FlAsH permits labeling of the entire population of MtrC, including proteolytic fragments resulting from incorrect maturation. We demonstrate specific labeling by CrAsH of engineered MtrC which is dependent on the presence of a functional type-2 secretion system (T2S), as evidenced by T2S system gspD or gspG deletion mutants which are incapable of CrAsH labeling. Under these latter conditions, MtrC undergoes proteolytic degradation to form a large 35-38 kDa fragment; this degradation product is also resolved during normal turnover of the CrAsH-labeled MtrC protein. No MtrC protein is released into the medium during turnover, suggesting the presence of cellular turnover systems involving MtrC reuptake and degradation. The mature MtrC localized on the outer membrane is a long-lived protein, with a turnover rate of 0.043 hr-1 that is insensitive to O2 concentration. Maturation of MtrC is relatively inefficient, with substantial rates of turnover of the immature protein prior to export to the outer membrane (i.e., 0.028 hr-1) that are consistent with the inherent complexity associated with correct heme insertion and acylation of MtrC that occurs in the periplasm prior to its targeting to the outer membrane. These latter results suggest that MtrC protein trafficking to the outer membrane and its subsequent degradation are tightly regulated, which is consistent with cellular processing pathways that target MtrC to extracellular structures and their possible role in promoting electron transfer from Shewanella to extracellular acceptors.

  16. Development of experimental methods to measure osmosis-driven water flux and molecular transport across nanoporous graphene membranes

    E-Print Network [OSTI]

    Jang, Doojoon

    2015-01-01

    Graphene, an atomically thin planar lattice of sp2 bonded carbon atoms with high strength and impermeability, has drawn attention as a promising next generation high flux separation membrane. Molecular dynamics simulations ...

  17. Selective transport of copper(I, II), cadmium(II), and zinc(II) ions through a supported liquid membrane containing bathocuproine, neocuproine, or bathophenanthroline

    SciTech Connect (OSTI)

    Saito, Takashi )

    1994-06-01

    Some selective transport systems for heavy metallic ions through a supported liquid membrane (SLM) containing a 2,2[prime]-dipyridyl derivative ligand, 4,7-diphenyl-2,9-dimethyl-1, 10-phenanthroline (bathocuproine), 2,9-dimethyl-1,10-phenanthroline (neocuproine), or 4,7-diphenyl-1,10-phenanthroline (bathophenanthroline), were investigated. The transport of copper(I, II), cadmium(II), zinc(II), lead(II), and cobalt(II) ions was accomplished with a halogen ion such as chloride, bromide, or iodide ion as a pairing ion species for any SLM. The ranking of the permeability of the metallic ions was Cu[sup +,2+], Zn[sup 2+], Cd[sup 2+] [much gt] Pb[sup 2+], Co[sup 2+]. When the oxidation-reduction potential gradient was used as a driving force for metallic ions, the transport of Cu[sup +] ions was higher than those of Cd[sup 2+] and Zn[sup 2+] ions for any SLM containing bathocuproine, neocuproine, or bathophenanthroline. On the other hand, in the transport system which used the concentration gradient of pairing ion species, the permeability of the Cu[sup 2+] ion decreased whereas that of the Cd[sup 2+] ion increased. Moreover, it was found that the different selectivity for the transport of metallic ions is produced by using various pairing ion species. 18 refs., 9 figs.

  18. Membrane proteomic analysis of pancreatic cancer cells

    E-Print Network [OSTI]

    Liu, Xiaojun; Zhang, Min; Go, Vay Liang W; Hu, Shen

    2010-01-01

    and amino acids, protein folding/ unfolded protein response,ER regulation of protein folding 8.98 Ketone body metabolismcatabolic process; protein folding/transport; response to

  19. Proteins

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Proteins Protein Engineering, Structure, and Function Los Alamos scientists seek a comprehensive understanding of the structure and function of proteins which can lead to a...

  20. System and methods for predicting transmembrane domains in membrane proteins and mining the genome for recognizing G-protein coupled receptors

    DOE Patents [OSTI]

    Trabanino, Rene J; Vaidehi, Nagarajan; Hall, Spencer E; Goddard, William A; Floriano, Wely

    2013-02-05

    The invention provides computer-implemented methods and apparatus implementing a hierarchical protocol using multiscale molecular dynamics and molecular modeling methods to predict the presence of transmembrane regions in proteins, such as G-Protein Coupled Receptors (GPCR), and protein structural models generated according to the protocol. The protocol features a coarse grain sampling method, such as hydrophobicity analysis, to provide a fast and accurate procedure for predicting transmembrane regions. Methods and apparatus of the invention are useful to screen protein or polynucleotide databases for encoded proteins with transmembrane regions, such as GPCRs.

  1. 12.1 Introduction The vast majority of biophysical studies of membrane proteins (MPs) at the atomic

    E-Print Network [OSTI]

    - spectively. Above a certain concentration and temperature, i.e., the critical micellar concentration (cmc well they mimic native membranes, especially when a functional test is difficult or impossible to set, on the contrary, exotic surfactants like amphipols, which could be thought to be inappropriate given

  2. Understanding the Relationship between Osmotic Membrane Structure and Separation Performance

    E-Print Network [OSTI]

    Wong, Mavis C.Y.

    2014-01-01

    Review of Transport through Osmotic Membranes. , J. Membr.and solution chemistry on osmotic structure and performance.relationship between osmotic membrane structure, chemistry,

  3. Autotransporters: The Cellular Environment Reshapes a Folding Mechanism to Promote Protein Transport

    E-Print Network [OSTI]

    Clark, Patricia L.

    the cellular environment affects protein folding mechanisms. Here, we focus on one unique aspect affect protein folding kinetics and the conformations of folding intermediates? We focus on recent have been made to understand the mechanisms by which proteins fold to their native conformations.3

  4. Proteins

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Proteins Scientists manipulate and mimic proteins for use in creating solutions for medicine, sustainable energy, and more Read caption + Los Alamos National Laboratory graduate...

  5. Carrier-mediated transport of actinide ions using supported liquid membranes containing TODGA as the carrier extractant

    SciTech Connect (OSTI)

    Panja, S.; Dakshinamoorthy, A.; Munshi, S.K.; Dey, P.K.; Mohapatra, P.K.; Manchanda, V.K.

    2008-07-01

    The transport behavior of Pu{sup 3+} under varying reducing conditions was investigated from a feed containing 3.0 M HNO{sub 3} into a receiver phase containing 0.1 M HNO{sub 3} using TODGA (N,N,N',N' - tetraoctyl-diglycolamide) as the carrier ligand. A mixture of 0.2 M hydroxyl ammonium nitrate and 0.2 M hydrazinium nitrate (used in the feed as the reducing agent) has been found to be effective for quantitative (>99%) transport of the trivalent Pu in about 3 h. Transport of trivalent plutonium in 3 h (>99%) was higher as compared to that of the tetravalent plutonium (94%), though their D values followed an opposite trend. The permeability coefficient (P) of Pu{sup 3+} was (4.63 {+-} 0.26) x 10{sup -3} cm/s as compared to (2.10 {+-} 0.14) x 10{sup -3} cm/s for Pu{sup 4+} and (3.67 {+-} 0.06) x 10{sup -3} cm/s Am{sup 3+}. P values of trivalent actinide ions such as Am{sup 3+}, Pu{sup 3+}, and Cm{sup 3+} are compared with their distribution data. (authors)

  6. Identifying Calcium Channels and Porters in Plant Membranes

    SciTech Connect (OSTI)

    Sze, Heven

    1998-04-01

    The overall objectives of the proposal submitted in 6/90 was to understand how Ca was transported across plant membranes, and how these transport pathways were regulated. Ca participates in many cellular processes, including the transduction of hormonal and environmental signals, secretion, and protein folding. These processes depend on the coordination of passive Ca fluxes via channels and active Ca pumps; however these transport pathways are poorly understood in plants. We had, therefore, proposed to identify and characterize Ca transport proteins, such as the inositol-1 ,4,5-trisphosphate (IP3)-sensitive Ca channels and Ca pumps. We have had difficulties characterizing and cloning the IP3-sensitive Ca channel, but have made considerable progress on the biochemical characterization, and partial purification of a 120 kD Ca-pumping ATPase. We have begun to determine the structure of Ca pumps by molecular cloning and have already obtained a partial cDNA with features characteristic of Ca pumps.

  7. Ninth International Workshop on Plant Membrane Biology

    SciTech Connect (OSTI)

    Not Available

    1993-12-31

    This report is a compilation of abstracts from papers which were discussed at a workshop on plant membrane biology. Topics include: plasma membrane ATP-ases; plant-environment interactions, membrane receptors; signal transduction; ion channel physiology; biophysics and molecular biology; vaculor H+ pumps; sugar carriers; membrane transport; and cellular structure and function.

  8. Laterally Mobile, Functionalized Self-Assembled Monolayers at the Fluorous?Aqueous Interface in a Plug-Based Microfluidic System: Characterization and Testing with Membrane Protein Crystallization

    SciTech Connect (OSTI)

    Kreutz, Jason E.; Li, Liang; Roach, L. Spencer; Hatakeyama, Takuji; Ismagilov, Rustem F.; (UC)

    2009-11-04

    This paper describes a method to generate functionalizable, mobile self-assembled monolayers (SAMs) in plug-based microfluidics. Control of interfaces is advancing studies of biological interfaces, heterogeneous reactions, and nanotechnology. SAMs have been useful for such studies, but they are not laterally mobile. Lipid-based methods, though mobile, are not easily amenable to setting up the hundreds of experiments necessary for crystallization screening. Here we demonstrate a method, complementary to current SAM and lipid methods, for rapidly generating mobile, functionalized SAMs. This method relies on plugs, droplets surrounded by a fluorous carrier fluid, to rapidly explore chemical space. Specifically, we implemented his-tag binding chemistry to design a new fluorinated amphiphile, RfNTA, using an improved one-step synthesis of RfOEG under Mitsunobu conditions. RfNTA introduces specific binding of protein at the fluorous-aqueous interface, which concentrates and orients proteins at the interface, even in the presence of other surfactants. We then applied this approach to the crystallization of a his-tagged membrane protein, Reaction Center from Rhodobacter sphaeroides, performed 2400 crystallization trials, and showed that this approach can increase the range of crystal-producing conditions, the success rate at a given condition, the rate of nucleation, and the quality of the crystal formed.

  9. Cell envelope of Bordetella pertussis: immunological and biochemical analyses and characterization of a major outer membrane porin protein

    SciTech Connect (OSTI)

    Armstrong, S.K.

    1986-01-01

    Surface molecules of Bordetella pertussis which may be important in metabolism, pathogenesis, and immunity to whooping cough were examined using cell fractionation and /sup 125/I cell surface labeling. Antigenic envelope proteins were examined by immunofluorescence microscopy and Western blotting procedures using monoclonal antibodies and convalescent sera. A surface protein with a high M/sub r/, missing in a mutant lacking the filamentous hemagglutinin, was identified in virulent Bordetella pertussis but was absent in virulent B. pertussis strains. At least three envelope proteins were found only in virulent B. pertussis strains and were absent or diminished in avirulent and most phenotypically modulated strains. Transposon-induced mutants unable to produce hemolysin, dermonecrotic toxin, pertussis toxin, and filamentous hemagglutinin also lacked these three envelope proteins, confirming that virulence-associated envelope proteins were genetically regulated with other virulence-associated traits. Two dimensional gel electrophoresis revealed at least five heat modifiable proteins which migrated as higher or lower M/sub r/ moieties if solubilized at 25/sup 0/C instead of 100/sup 0/C.

  10. Crystal structure of a concentrative nucleoside transporter from Vibrio cholerae at 2.4;#8201;Å

    SciTech Connect (OSTI)

    Johnson, Zachary Lee; Cheong, Cheom-Gil; Lee, Seok-Yong (Duke)

    2012-07-11

    Nucleosides are required for DNA and RNA synthesis, and the nucleoside adenosine has a function in a variety of signalling processes. Transport of nucleosides across cell membranes provides the major source of nucleosides in many cell types and is also responsible for the termination of adenosine signalling. As a result of their hydrophilic nature, nucleosides require a specialized class of integral membrane proteins, known as nucleoside transporters (NTs), for specific transport across cell membranes. In addition to nucleosides, NTs are important determinants for the transport of nucleoside-derived drugs across cell membranes. A wide range of nucleoside-derived drugs, including anticancer drugs (such as Ara-C and gemcitabine) and antiviral drugs (such as zidovudine and ribavirin), have been shown to depend, at least in part, on NTs for transport across cell membranes. Concentrative nucleoside transporters, members of the solute carrier transporter superfamily SLC28, use an ion gradient in the active transport of both nucleosides and nucleoside-derived drugs against their chemical gradients. The structural basis for selective ion-coupled nucleoside transport by concentrative nucleoside transporters is unknown. Here we present the crystal structure of a concentrative nucleoside transporter from Vibrio cholerae in complex with uridine at 2.4 {angstrom}. Our functional data show that, like its human orthologues, the transporter uses a sodium-ion gradient for nucleoside transport. The structure reveals the overall architecture of this class of transporter, unravels the molecular determinants for nucleoside and sodium binding, and provides a framework for understanding the mechanism of nucleoside and nucleoside drug transport across cell membranes.

  11. Development of anomalous diffusion among crowding proteins

    E-Print Network [OSTI]

    Margaret R. Horton; Felix Höfling; Joachim O. Rädler; Thomas Franosch

    2010-03-19

    In cell membranes, proteins and lipids diffuse in a highly crowded and heterogeneous landscape, where aggregates and dense domains of proteins or lipids obstruct the path of diffusing molecules. In general, hindered motion gives rise to anomalous transport, though the nature of the onset of this behavior is still under debate and difficult to investigate experimentally. Here, we present a systematic study where proteins bound to supported lipid membranes diffuse freely in two dimensions, but are increasingly hindered by the presence of other like proteins. In our model system, the surface coverage of the protein avidin on the lipid bilayer is well controlled by varying the concentration of biotinylated lipid anchors. Using fluorescence correlation spectroscopy (FCS), we measure the time correlation function over long times and convert it to the mean-square displacement of the diffusing proteins. Our approach allows for high precision data and a clear distinction between anomalous and normal diffusion. It enables us to investigate the onset of anomalous diffusion, which takes place when the area coverage of membrane proteins increases beyond approximately 5%. This transition region exhibits pronounced spatial heterogeneities. Increasing the packing fraction further, transport becomes more and more anomalous, manifested in a decrease of the exponent of subdiffusion.

  12. Intra-membrane molecular interactions of K%2B channel proteins : application to problems in biodefense and bioenergy.

    SciTech Connect (OSTI)

    Moczydlowski, Edward G.

    2013-07-01

    Ion channel proteins regulate complex patterns of cellular electrical activity and ionic signaling. Certain K+ channels play an important role in immunological biodefense mechanisms of adaptive and innate immunity. Most ion channel proteins are oligomeric complexes with the conductive pore located at the central subunit interface. The long-term activity of many K+ channel proteins is dependent on the concentration of extracellular K+; however, the mechanism is unclear. Thus, this project focused on mechanisms underlying structural stability of tetrameric K+ channels. Using KcsA of Streptomyces lividans as a model K+ channel of known structure, the molecular basis of tetramer stability was investigated by: 1. Bioinformatic analysis of the tetramer interface. 2. Effect of two local anesthetics (lidocaine, tetracaine) on tetramer stability. 3. Molecular simulation of drug docking to the ion conduction pore. The results provide new insights regarding the structural stability of K+ channels and its possible role in cell physiology.

  13. Transportation

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach Home RoomPreservationBio-Inspired SolarAbout / Transforming Y-12Capacity-Forum Sign InTransportation

  14. Expression Analysis of BB0174, A Membrane Protein of Borrelia burgdorferi, the Causative Agent of Lyme Disease 

    E-Print Network [OSTI]

    Modarelli, Joseph 1991-

    2012-04-30

    H and temperature conditions similar to those found in the unfed tick and again from the fed tick. cDNA will then be generated and PCR analysis using specific primers for bb0174 and neighboring regions will be conducted. The BB0174 protein levels will also...

  15. Identification and Structural Analysis of a Novel Carboxysome Shell Protein with Implications for Metabolite Transport

    E-Print Network [OSTI]

    Klein, Michael G.

    Bacterial microcompartments (BMCs) are polyhedral bodies, composed entirely of proteins, that function as organelles in bacteria; they promote subcellular processes by encapsulating and co-localizing targeted enzymes with ...

  16. Transport of misfolded endoplasmic reticulum proteins to the cell surface by MHC class II molecules

    E-Print Network [OSTI]

    2013-01-01

    Structure of the human class I histocompatibility antigen,struc- ture of the human class II MHC protein HLA-DR1ture of an intermediate in class II MHC maturation: CLIP

  17. A MOLECULAR ANALYSIS OF PROTEIN TRAFFICKING IN THE VERTEBRATE RETINA: IMPLICATIONS FOR INTRAFLAGELLAR TRANSPORT AND DISEASE 

    E-Print Network [OSTI]

    Krock, Bryan L.

    2010-07-14

    Vertebrate photoreceptors are highly specialized sensory neurons that utilize a modified cilium known as the outer segment to detect light. Proper trafficking of proteins to the outer segment is essential for photoreceptor function and survival...

  18. The research cluster Membranes for Energy and Sustainable Processes (or in full Membrane Materials Science

    E-Print Network [OSTI]

    Twente, Universiteit

    transport through polymer membranes to identify structure-properties relations and on the application and optimization of the transport of ions through these membranes. Figure 4: Coal fired power plant (Borssele and permeation) through polymer membranes to identify structure-properties relations and on the application

  19. Overdamped thermal ratchets in one and more dimensions. Kinesin transport and protein folding

    E-Print Network [OSTI]

    Ernesto Gonzalez-Candela; Victor Romero-Rochin

    2006-05-26

    The overdamped thermal ratchet driven by an external (Orstein-Uhlenbeck) noise is revisited. The ratchet we consider is unbounded in space and not necessarily periodic . We briefly discuss the conditions under which current is obtained by analyzing the corresponding Fokker-Planck equation and its lack of stationary states. Next, two examples in more than one dimension and related to biological systems are presented. First, a two-dimensional model of a ``kinesin protein'' on a ``microtubule'' is analyzed and, second, we suggest that a ratchet mechanism may be behind the folding of proteins; the latter is elaborated with a multidimensional ratchet model.

  20. Membrane stabilizer

    DOE Patents [OSTI]

    Mingenbach, W.A.

    1988-02-09

    A device is provided for stabilizing a flexible membrane secured within a frame, wherein a plurality of elongated arms are disposed radially from a central hub which penetrates the membrane, said arms imposing alternately against opposite sides of the membrane, thus warping and tensioning the membrane into a condition of improved stability. The membrane may be an opaque or translucent sheet or other material. 10 figs.

  1. YidC protein, a molecular chaperone for LacY protein folding via the SecYEG protein machinery

    E-Print Network [OSTI]

    Zhu, L; Kaback, HR; Dalbey, RE

    2013-01-01

    GroEL-GroES- mediated protein folding. Chem. Rev. 106, 1917–of chaperone-mediated protein folding in the cytosol. Nat.that impair membrane protein folding and generate a membrane

  2. STRUCTURAL REQUIREMENTS OF ORGANIC ANION TRANSPORTING POLYPEPTIDE MEDIATED TRANSPORT

    E-Print Network [OSTI]

    Weaver, Yi Miao

    2010-04-12

    The organic anion transporting polypeptides (human: OATP; other: Oatp) form a mammalian transporter superfamily that mediates the transport of structurally unrelated compounds across the cell membrane. Members in this superfamily participate...

  3. Folding and Function of Proteorhodopsins in Photoenergy Transducing Membranes

    SciTech Connect (OSTI)

    Spudich, John L

    2012-08-10

    The overall research objectives are to develop proteorhodopsin (PR) proteins as a model system for {alpha}?-helical membrane protein insertion and folding, and to advance understanding of the diversity and mechanisms of PRs, a large family of photoenergy transducers (~4000 identified) abundant in the world’s oceans. Specific aims are: (1) To develop a highefficiency genetic selection procedure for light-driven proton-pumping in E. coli cells. Such a procedure would provide a positive selection method for proper folding and function of PRs in the E. coli membrane. (2) Characterize flash-induced absorption changes and photocurrents in PR variants in organisms from various environments, and their expression level and function when expressed in E. coli. Subaims are to: (a) elucidate the relationship of the transport mechanism to mechanisms of other microbial rhodopsins, some of which like PRs function as ion transporters and some of which use light energy to activate signaling pathways (sensory rhodopsins); and (b) identify important residues and chemical events in light-driven proton transport by PRs. In addition to their importance to the energy of the biosphere PRs have attracted interest for their potential for use in making photoenergy-transducing membranes for bioengineering applications.

  4. Direct-hydrogen-fueled proton-exchange-membrane fuel cell system for transportation applications: Conceptual vehicle design report pure fuel cell powertrain vehicle

    SciTech Connect (OSTI)

    Oei, D.; Kinnelly, A.; Sims, R.; Sulek, M.; Wernette, D.

    1997-02-01

    In partial fulfillment of the Department of Energy (DOE) Contract No. DE-AC02-94CE50389, {open_quotes}Direct-Hydrogen-Fueled Proton-Exchange-Membrane (PEM) Fuel Cell for Transportation Applications{close_quotes}, this preliminary report addresses the conceptual design and packaging of a fuel cell-only powered vehicle. Three classes of vehicles are considered in this design and packaging exercise, the Aspire representing the small vehicle class, the Taurus or Aluminum Intensive Vehicle (AIV) Sable representing the mid-size vehicle and the E-150 Econoline representing the van-size class. A fuel cell system spreadsheet model and Ford`s Corporate Vehicle Simulation Program (CVSP) were utilized to determine the size and the weight of the fuel cell required to power a particular size vehicle. The fuel cell power system must meet the required performance criteria for each vehicle. In this vehicle design and packaging exercise, the following assumptions were made: fuel cell power system density of 0.33 kW/kg and 0.33 kg/liter, platinum catalyst loading less than or equal to 0.25 mg/cm{sup 2} total and hydrogen tanks containing gaseous hydrogen under 340 atm (5000 psia) pressure. The fuel cell power system includes gas conditioning, thermal management, humidity control, and blowers or compressors, where appropriate. This conceptual design of a fuel cell-only powered vehicle will help in the determination of the propulsion system requirements for a vehicle powered by a PEMFC engine in lieu of the internal combustion (IC) engine. Only basic performance level requirements are considered for the three classes of vehicles in this report. Each vehicle will contain one or more hydrogen storage tanks and hydrogen fuel for 560 km (350 mi) driving range. Under these circumstances, the packaging of a fuel cell-only powered vehicle is increasingly difficult as the vehicle size diminishes.

  5. Solid-state membrane module

    DOE Patents [OSTI]

    Gordon, John Howard (Salt Lake City, UT); Taylor, Dale M. (Murray, UT)

    2011-06-07

    Solid-state membrane modules comprising at least one membrane unit, where the membrane unit has a dense mixed conducting oxide layer, and at least one conduit or manifold wherein the conduit or manifold comprises a dense layer and at least one of a porous layer and a slotted layer contiguous with the dense layer. The solid-state membrane modules may be used to carry out a variety of processes including the separating of any ionizable component from a feedstream wherein such ionizable component is capable of being transported through a dense mixed conducting oxide layer of the membrane units making up the membrane modules. For ease of construction, the membrane units may be planar.

  6. Proteins

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration wouldMass mapSpeedingProgramExemptionsProtein Dynamics Hit the BigProteinProteins Scientists

  7. Membranes, methods of making membranes, and methods of separating gases using membranes

    DOE Patents [OSTI]

    Ho, W. S. Winston

    2012-10-02

    Membranes, methods of making membranes, and methods of separating gases using membranes are provided. The membranes can include at least one hydrophilic polymer, at least one cross-linking agent, at least one base, and at least one amino compound. The methods of separating gases using membranes can include contacting a gas stream containing at least one of CO.sub.2, H.sub.2S, and HCl with one side of a nonporous and at least one of CO.sub.2, H.sub.2S, and HCl selectively permeable membrane such that at least one of CO.sub.2, H.sub.2S, and HCl is selectively transported through the membrane.

  8. The high risk HPV16 L2 minor capsid protein has multiple transport signals that mediate its nucleocytoplasmic traffic

    SciTech Connect (OSTI)

    Mamoor, Shahan; Onder, Zeynep [Biology Department, Boston College, Chestnut Hill, MA 02467 (United States)] [Biology Department, Boston College, Chestnut Hill, MA 02467 (United States); Karanam, Balasubramanyam; Kwak, Kihyuck [Department of Pathology, The Johns Hopkins University, Baltimore, MD 21231 (United States)] [Department of Pathology, The Johns Hopkins University, Baltimore, MD 21231 (United States); Bordeaux, Jennifer; Crosby, Lauren [Biology Department, Boston College, Chestnut Hill, MA 02467 (United States)] [Biology Department, Boston College, Chestnut Hill, MA 02467 (United States); Roden, Richard B.S. [Department of Pathology, The Johns Hopkins University, Baltimore, MD 21231 (United States)] [Department of Pathology, The Johns Hopkins University, Baltimore, MD 21231 (United States); Moroianu, Junona, E-mail: moroianu@bc.edu [Biology Department, Boston College, Chestnut Hill, MA 02467 (United States)] [Biology Department, Boston College, Chestnut Hill, MA 02467 (United States)

    2012-01-20

    In this study we examined the transport signals contributing to HPV16 L2 nucleocytoplasmic traffic using confocal microscopy analysis of enhanced green fluorescent protein-L2 (EGFP-L2) fusions expressed in HeLa cells. We confirmed that both nuclear localization signals (NLSs), the nNLS (1MRHKRSAKRTKR12) and cNLS (456RKRRKR461), previously characterized in vitro (Darshan et al., 2004), function independently in vivo. We discovered that a middle region rich in arginine residues (296SRRTGIRYSRIGNKQTLRTRS316) functions as a nuclear retention sequence (NRS), as mutagenesis of critical arginine residues within this NRS reduced the fraction of L2 in the nucleus despite the presence of both NLSs. Significantly, the infectivity of HPV16 pseudoviruses containing either RR297AA or RR297EE within the L2 NRS was strongly reduced both in HaCaT cells and in a murine challenge model. Experiments using Ratjadone A nuclear export inhibitor and mutation-localization analysis lead to the discovery of a leucine-rich nuclear export signal ({sub 462}LPYFFSDVSL) mediating 16L2 nuclear export. These data indicate that HPV16 L2 nucleocytoplasmic traffic is dependent on multiple functional transport signals.

  9. ADVANCED MATERIALS Membranes for Clean Water

    E-Print Network [OSTI]

    ADVANCED MATERIALS Membranes for Clean Water Objective This project provides measurement solutions that probe the surface and internal structure of polymer membranes used in water purification, and correlate that structure to the transport of water and other species through the membrane. Our methods are focused

  10. OXYGEN TRANSPORT MEMBRANE (OTM) AIDED

    E-Print Network [OSTI]

    · Benefits to California · Overall Technology Assessment · Appendices o Appendix A: Final Report (under · Industrial/Agricultural/Water End-Use Energy Efficiency · Renewable Energy Technologies · Environmentally

  11. Staged membrane oxidation reactor system

    DOE Patents [OSTI]

    Repasky, John Michael; Carolan, Michael Francis; Stein, VanEric Edward; Chen, Christopher Ming-Poh

    2012-09-11

    Ion transport membrane oxidation system comprising (a) two or more membrane oxidation stages, each stage comprising a reactant zone, an oxidant zone, one or more ion transport membranes separating the reactant zone from the oxidant zone, a reactant gas inlet region, a reactant gas outlet region, an oxidant gas inlet region, and an oxidant gas outlet region; (b) an interstage reactant gas flow path disposed between each pair of membrane oxidation stages and adapted to place the reactant gas outlet region of a first stage of the pair in flow communication with the reactant gas inlet region of a second stage of the pair; and (c) one or more reactant interstage feed gas lines, each line being in flow communication with any interstage reactant gas flow path or with the reactant zone of any membrane oxidation stage receiving interstage reactant gas.

  12. Staged membrane oxidation reactor system

    DOE Patents [OSTI]

    Repasky, John Michael; Carolan, Michael Francis; Stein, VanEric Edward; Chen, Christopher Ming-Poh

    2014-05-20

    Ion transport membrane oxidation system comprising (a) two or more membrane oxidation stages, each stage comprising a reactant zone, an oxidant zone, one or more ion transport membranes separating the reactant zone from the oxidant zone, a reactant gas inlet region, a reactant gas outlet region, an oxidant gas inlet region, and an oxidant gas outlet region; (b) an interstage reactant gas flow path disposed between each pair of membrane oxidation stages and adapted to place the reactant gas outlet region of a first stage of the pair in flow communication with the reactant gas inlet region of a second stage of the pair; and (c) one or more reactant interstage feed gas lines, each line being in flow communication with any interstage reactant gas flow path or with the reactant zone of any membrane oxidation stage receiving interstage reactant gas.

  13. Staged membrane oxidation reactor system

    DOE Patents [OSTI]

    Repasky, John Michael; Carolan, Michael Francis; Stein, VanEric Edward; Chen, Christopher Ming-Poh

    2013-04-16

    Ion transport membrane oxidation system comprising (a) two or more membrane oxidation stages, each stage comprising a reactant zone, an oxidant zone, one or more ion transport membranes separating the reactant zone from the oxidant zone, a reactant gas inlet region, a reactant gas outlet region, an oxidant gas inlet region, and an oxidant gas outlet region; (b) an interstage reactant gas flow path disposed between each pair of membrane oxidation stages and adapted to place the reactant gas outlet region of a first stage of the pair in flow communication with the reactant gas inlet region of a second stage of the pair; and (c) one or more reactant interstage feed gas lines, each line being in flow communication with any interstage reactant gas flow path or with the reactant zone of any membrane oxidation stage receiving interstage reactant gas.

  14. Charged Amino Acids (R83, E567, D617, E625, R669, and K678) of CusA Are Required for Metal Ion Transport in the Cus Efflux System

    SciTech Connect (OSTI)

    Su, Chih-Chia; Long, Feng; Lei, Hsiang-Ting; Reddy Bolla, Jani; Do, Sylvia V.; Rajashankar, Kanagalaghatta R.; Yu, Edward W. (Cornell); (Iowa State)

    2012-10-23

    Gram-negative bacteria expel various toxic chemicals via tripartite efflux pumps belonging to the resistance-nodulation-cell division superfamily. These pumps span both the inner and outer membranes of the cell. The three components of these tripartite systems are an inner-membrane, substrate-binding transporter (or pump); a periplasmic membrane fusion protein (or adaptor); and an outer-membrane-anchored channel. These three efflux proteins interact in the periplasmic space to form the three-part complexes. We previously presented the crystal structures of both the inner-membrane transporter CusA and membrane fusion protein CusB of the CusCBA tripartite efflux system from Escherichia coli. We also described the co-crystal structure of the CusBA adaptor-transporter, revealing that the trimeric CusA efflux pump assembles with six CusB protein molecules to form the complex CusB{sub 6}-CusA{sub 3}. We here report three different conformers of the crystal structures of CusBA-Cu(I), suggesting a mechanism on how Cu(I) binding initiates a sequence of conformational transitions in the transport cycle. Genetic analysis and transport assays indicate that charged residues, in addition to the methionine pairs and clusters, are essential for extruding metal ions out of the cell.

  15. Proteins

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

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  16. Production of permeable cellulose triacetate membranes

    DOE Patents [OSTI]

    Johnson, B.M.

    1986-12-23

    A phase inversion process for the preparation of cellulose triacetate (CTA) and regenerated cellulose membranes is disclosed. Such membranes are useful as supports for liquid membranes in facilitated transport processes, as microfiltration membranes, as dialysis or ultrafiltration membranes, and for the preparation of ion-selective electrodes. The process comprises the steps of preparing a casting solution of CTA in a solvent comprising a mixture of cyclohexanone and methylene chloride, casting a film from the casting solution, and immersing the cast film in a methanol bath. The resulting CTA membrane may then be hydrolyzed to regenerated cellulose using conventional techniques.

  17. Production of permeable cellulose triacetate membranes

    DOE Patents [OSTI]

    Johnson, Bruce M. (Bend, OR)

    1986-01-01

    A phase inversion process for the preparation of cellulose triacetate (CTA) and regenerated cellulose membranes is disclosed. Such membranes are useful as supports for liquid membranes in facilitated transport processes, as microfiltration membranes, as dialysis or ultrafiltration membranes, and for the preparation of ion-selective electrodes. The process comprises the steps of preparing a casting solution of CTA in a solvent comprising a mixture of cyclohexanone and methylene chloride, casting a film from the casting solution, and immersing the cast film in a methanol bath. The resulting CTA membrane may then be hydrolyzed to regenerated cellulose using conventional techniques.

  18. The MUC4 membrane-bound mucin regulates esophageal cancer cell proliferation and migration properties: Implication for S100A4 protein

    SciTech Connect (OSTI)

    Bruyere, Emilie; Jonckheere, Nicolas; Frenois, Frederic; Universite Lille-Nord de France, 1 place de Verdun, 59045 Lille Cedex ; Mariette, Christophe; Universite Lille-Nord de France, 1 place de Verdun, 59045 Lille Cedex; Department of Digestive and Oncological Surgery, University Hospital Claude Huriez, 1 place de Verdun, 59045 Lille Cedex ; Van Seuningen, Isabelle

    2011-09-23

    Highlights: {yields} Loss of MUC4 reduces proliferation of esophageal cancer cells. {yields} MUC4 inhibition impairs migration of esophageal cancer cells but not their invasion. {yields} Loss of MUC4 significantly reduces in vivo tumor growth. {yields} Decrease of S100A4 induced by MUC4 inhibition impairs proliferation and migration. -- Abstract: MUC4 is a membrane-bound mucin known to participate in tumor progression. It has been shown that MUC4 pattern of expression is modified during esophageal carcinogenesis, with a progressive increase from metaplastic lesions to adenocarcinoma. The principal cause of development of esophageal adenocarcinoma is the gastro-esophageal reflux, and MUC4 was previously shown to be upregulated by several bile acids present in reflux. In this report, our aim was thus to determine whether MUC4 plays a role in biological properties of human esophageal cancer cells. For that stable MUC4-deficient cancer cell lines (shMUC4 cells) were established using a shRNA approach. In vitro (proliferation, migration and invasion) and in vivo (tumor growth following subcutaneous xenografts in SCID mice) biological properties of shMUC4 cells were analyzed. Our results show that shMUC4 cells were less proliferative, had decreased migration properties and did not express S100A4 protein when compared with MUC4 expressing cells. Absence of MUC4 did not impair shMUC4 invasiveness. Subcutaneous xenografts showed a significant decrease in tumor size when cells did not express MUC4. Altogether, these data indicate that MUC4 plays a key role in proliferative and migrating properties of esophageal cancer cells as well as is a tumor growth promoter. MUC4 mucin appears thus as a good therapeutic target to slow-down esophageal tumor progression.

  19. Structural Basis for Alginate Secretion Across the Bacterial Outer Membrane

    SciTech Connect (OSTI)

    J Whitney; I Hay; C Li; P Eckford; H Robinson; M Amaya; L Wood; D Ohman; C Bear; et al.

    2011-12-31

    Pseudomonas aeruginosa is the predominant pathogen associated with chronic lung infection among cystic fibrosis patients. During colonization of the lung, P. aeruginosa converts to a mucoid phenotype characterized by the overproduction of the exopolysaccharide alginate. Secretion of newly synthesized alginate across the outer membrane is believed to occur through the outer membrane protein AlgE. Here we report the 2.3 {angstrom} crystal structure of AlgE, which reveals a monomeric 18-stranded {beta}-barrel characterized by a highly electropositive pore constriction formed by an arginine-rich conduit that likely acts as a selectivity filter for the negatively charged alginate polymer. Interestingly, the pore constriction is occluded on either side by extracellular loop L2 and an unusually long periplasmic loop, T8. In halide efflux assays, deletion of loop T8 ({Delta}T8-AlgE) resulted in a threefold increase in anion flux compared to the wild-type or {Delta}L2-AlgE supporting the idea that AlgE forms a transport pathway through the membrane and suggesting that transport is regulated by T8. This model is further supported by in vivo experiments showing that complementation of an algE deletion mutant with {Delta}T8-AlgE impairs alginate production. Taken together, these studies support a mechanism for exopolysaccharide export across the outer membrane that is distinct from the Wza-mediated translocation observed in canonical capsular polysaccharide export systems.

  20. Structural basis for alginate secretion across the bacterial outer membrane

    SciTech Connect (OSTI)

    Whitney, J.C.; Robinson, H.; Hay, I. D.; Li, C.; Eckford, P. D. W.; Amaya, M. F.; Wood, L. F.; Ohman, D. E.; Bear, C. E.; Rehm, B. H.; Howell, P. L.

    2011-08-09

    Pseudomonas aeruginosa is the predominant pathogen associated with chronic lung infection among cystic fibrosis patients. During colonization of the lung, P. aeruginosa converts to a mucoid phenotype characterized by the overproduction of the exopolysaccharide alginate. Secretion of newly synthesized alginate across the outer membrane is believed to occur through the outer membrane protein AlgE. Here we report the 2.3 {angstrom} crystal structure of AlgE, which reveals a monomeric 18-stranded {beta}-barrel characterized by a highly electropositive pore constriction formed by an arginine-rich conduit that likely acts as a selectivity filter for the negatively charged alginate polymer. Interestingly, the pore constriction is occluded on either side by extracellular loop L2 and an unusually long periplasmic loop, T8. In halide efflux assays, deletion of loop T8 ({Delta}T8-AlgE) resulted in a threefold increase in anion flux compared to the wild-type or {Delta}L2-AlgE supporting the idea that AlgE forms a transport pathway through the membrane and suggesting that transport is regulated by T8. This model is further supported by in vivo experiments showing that complementation of an algE deletion mutant with {Delta}T8-AlgE impairs alginate production. Taken together, these studies support a mechanism for exopolysaccharide export across the outer membrane that is distinct from the Wza-mediated translocation observed in canonical capsular polysaccharide export systems.

  1. A unified model of electroporation and molecular transport

    E-Print Network [OSTI]

    Smith, Kyle Christopher

    2011-01-01

    Biological membranes form transient, conductive pores in response to elevated transmembrane voltage, a phenomenon termed electroporation. These pores facilitate electrical and molecular transport across cell membranes that ...

  2. Membrane fluctuations around inclusions

    E-Print Network [OSTI]

    Christian D. Santangelo; Oded Farago

    2004-01-15

    The free energy of inserting a protein into a membrane is determined by considering the variation in the spectrum of thermal fluctuations in response to the presence of a rigid inclusion. Both numerically and through a simple analytical approximation, we find that the primary effect of fluctuations is to reduce the effective surface tension, hampering the insertion at low surface tension. Our results, which should also be relevant for membrane pores, suggest (in contrast to classical nucleation theory) that a finite surface tension is necessary to facilitate the opening of a pore.

  3. Protein Flips Lipids Across Membranes

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

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  4. Protein kinesis: The dynamics of protein trafficking and stability

    SciTech Connect (OSTI)

    NONE

    1995-12-31

    The purpose of this conference is to provide a multidisciplinary forum for exchange of state-of-the-art information on protein kinesis. This volume contains abstracts of papers in the following areas: protein folding and modification in the endoplasmic reticulum; protein trafficking; protein translocation and folding; protein degradation; polarity; nuclear trafficking; membrane dynamics; and protein import into organelles.

  5. Amphiphiles for protein solubilization and stabilization

    DOE Patents [OSTI]

    Gellman, Samuel Helmer; Chae, Pil Seok; Laible, Phillip D; Wander, Marc J

    2014-11-04

    The invention provides amphiphiles for manipulating membrane proteins. The amphiphiles can feature carbohydrate-derived hydrophilic groups and branchpoints in the hydrophilic moiety and/or in a lipophilic moiety. Such amphiphiles are useful as detergents for solubilization and stabilization of membrane proteins, including photosynthetic protein superassemblies obtained from bacterial membranes.

  6. Amphiphiles for protein solubilization and stabilization

    DOE Patents [OSTI]

    Gellman, Samuel Helmer; Chae, Pil Seok; Laible, Philip D.; Wander, Marc J.

    2012-09-11

    The invention provides amphiphiles for manipulating membrane proteins. The amphiphiles can feature carbohydrate-derived hydrophilic groups and branchpoints in the hydrophilic moiety and/or in a lipophilic moiety. Such amphiphiles are useful as detergents for solubilization and stabilization of membrane proteins, including photosynthetic protein superassemblies obtained from bacterial membranes.

  7. The RCK Domain of the KtrAB K+ Transporter: Multiple Conformations of an Octameric Ring

    SciTech Connect (OSTI)

    Albright,R.; Vazquez Ibar, J.; Kim, C.; Gruner, S.; Morais-Cabral, J.

    2006-01-01

    The KtrAB ion transporter is a complex of the KtrB membrane protein and KtrA, an RCK domain. RCK domains regulate eukaryotic and prokaryotic membrane proteins involved in K{sup +} transport. Conflicting functional models have proposed two different oligomeric arrangements for RCK domains, tetramer versus octamer. Our results for the KtrAB RCK domain clearly show an octamer in solution and in the crystal. We determined the structure of this protein in three different octameric ring conformations that resemble the RCK-domain octamer observed in the MthK potassium channel but show striking differences in size and symmetry. We present experimental evidence for the association between one RCK octameric ring and two KtrB membrane proteins. These results provide insights into the quaternary organization of the KtrAB transporter and its mechanism of activation and show that the RCK-domain octameric ring model is generally applicable to other ion-transport systems.

  8. Isabella Inzoli Coupled transports of heat

    E-Print Network [OSTI]

    Kjelstrup, Signe

    about the transport of gas and heat across a membrane and to shed light on the coupling effects between.g. for catalytic cracking and for separation processes. The dynamic behaviour of the molecules entering a membrane transport of gas and heat into and across a silicalite membrane. These simulations allow to follow the time

  9. Knock-Out of the Genes Coding for the Rieske Protein and the ATP-Synthase -Subunit of Arabidopsis.

    E-Print Network [OSTI]

    , Research Triangle Park, North Carolina 27709 (J.Z.L.) In Arabidopsis, the nuclear genes PetC and AtpD code are evident when mRNA expression profiles of nucleus-encoded chloroplast proteins are considered, suggesting response. Plants use light energy to drive electron and proton transport across the thylakoid membrane

  10. Macroscopic Modeling of Polymer-Electrolyte Membranes

    SciTech Connect (OSTI)

    Weber, A.Z.; Newman, J.

    2007-04-01

    In this chapter, the various approaches for the macroscopic modeling of transport phenomena in polymer-electrolyte membranes are discussed. This includes general background and modeling methodologies, as well as exploration of the governing equations and some membrane-related topic of interest.

  11. Elastic moderation of intrinsically applied tension in lipid membranes

    E-Print Network [OSTI]

    Michael A. Lomholt; Bastien Loubet; John H. Ipsen

    2010-10-20

    Tension in lipid membranes is often controlled externally, by pulling on the boundary of the membrane or changing osmotic pressure across a curved membrane. But modifications of the tension can also be induced in an internal fashion, for instance as a byproduct of changing a membranes electric potential or, as observed experimentally, by activity of membrane proteins. Here we develop a theory which demonstrate how such internal contributions to the tension are moderated through elastic stretching of the membrane when the membrane is initially in a low tension floppy state.

  12. Axionic Membranes

    E-Print Network [OSTI]

    A. Aurilia; E. Spallucci

    1992-04-01

    A metal ring removed from a soap-water solution encloses a film of soap which can be mathematically described as a minimal surface having the ring as its only boundary. This is known to everybody. In this letter we suggest a relativistic extension of the above fluidodynamic system where the soap film is replaced by a Kalb-Ramond gauge potential $\\b(x)$ and the ring by a closed string. The interaction between the $\\b$-field and the string current excites a new configuration of the system consisting of a relativistic membrane bounded by the string. We call such a classical solution of the equation of motion an axionic membrane. As a dynamical system, the axionic membrane admits a Hamilton-Jacobi formulation which is an extension of the H-J theory of electromagnetic strings.

  13. Dialysis membrane for separation on microchips

    DOE Patents [OSTI]

    Singh, Anup K. (San Francisco, CA); Kirby, Brian J. (San Francisco, CA); Shepodd, Timothy J. (Livermore, CA)

    2010-07-13

    Laser-induced phase-separation polymerization of a porous acrylate polymer is used for in-situ fabrication of dialysis membranes inside glass microchannels. A shaped 355 nm laser beam is used to produce a porous polymer membrane with a thickness of about 15 .mu.m, which bonds to the glass microchannel and forms a semi-permeable membrane. Differential permeation through a membrane formed with pentaerythritol triacrylate was observed and quantified by comparing the response of the membrane to fluorescein and fluorescently tagging 200 nm latex microspheres. Differential permeation was observed and quantified by comparing the response to rhodamine 560 and lactalbumin protein in a membrane formed with SPE-methylene bisacrylamide. The porous membranes illustrate the capability for the present technique to integrate sample cleanup into chip-based analysis systems.

  14. Experimental phasing for structure determination using membrane...

    Office of Scientific and Technical Information (OSTI)

    in the literature concerning the experimental heavy-atom phasing of membrane-protein structures where the crystals have been grown using the lipid cubic phase (in meso) method. In...

  15. Crystalline Protein Domains and Lipid Bilayer Vesicle Shape Transformations

    E-Print Network [OSTI]

    Gast, Alice Petry

    Cellular membranes can take on a variety of shapes to assist biological processes including endocytosis. Membrane-associated protein domains provide a possible mechanism for determining membrane curvature. We study the ...

  16. Spontaneous Formation of Biomimetic, Nanoporous Membrane Channels...

    Office of Science (SC) Website

    of porins (protein-based biological channels), such as selective transport of protons, water, ions, and small molecules. The Impact The predictive design and creation of robust...

  17. Direct-hydrogen-fueled proton-exchange-membrane (PEM) fuel cell system for transportation applications. Quarterly technical progress report No. 4, April 1, 1995--June 30, 1995

    SciTech Connect (OSTI)

    Oei, D.

    1995-08-03

    This is the fourth Technical Progress Report for DOE Contract No. DE-AC02-94CE50389 awarded to Ford Motor Company on July 1, 1994. The overall objective of this contract is to advance the Proton-Exchange-Membrane (PEM) fuel cell technology for automotive applications. Specifically, the objectives resulting from this contract are to: (1) Develop and demonstrate on a laboratory propulsion system within 2-1/2 years a fully functional PEM Fuel Cell Power System (including fuel cell peripherals, peak power augmentation and controls). This propulsion system will achieve, or will be shown to have the growth potential to achieve, the weights, volumes, and production costs which are competitive with those same attributes of equivalently performing internal combustion engine propulsion systems; (2) Select and demonstrate a baseline onboard hydrogen storage method with acceptable weight, volume, cost, and safety features and analyze future alternatives; and (3) Analyze the hydrogen infrastructure components to ensure that hydrogen can be safely supplied to vehicles at geographically widespread convenient sites and at prices which are less than current gasoline prices per vehicle-mile; (4) Identify any future R&D needs for a fully integrated vehicle and for achieving the system cost and performance goals.

  18. Gas phase fractionation method using porous ceramic membrane

    DOE Patents [OSTI]

    Peterson, Reid A. (Madison, WI); Hill, Jr., Charles G. (Madison, WI); Anderson, Marc A. (Madison, WI)

    1996-01-01

    Flaw-free porous ceramic membranes fabricated from metal sols and coated onto a porous support are advantageously used in gas phase fractionation methods. Mean pore diameters of less than 40 .ANG., preferably 5-20 .ANG. and most preferably about 15 .ANG., are permeable at lower pressures than existing membranes. Condensation of gases in small pores and non-Knudsen membrane transport mechanisms are employed to facilitate and increase membrane permeability and permselectivity.

  19. Computational and experimental platform for understanding and optimizing water flux and salt rejection in nanoporous membranes.

    SciTech Connect (OSTI)

    Rempe, Susan B.

    2010-09-01

    Affordable clean water is both a global and a national security issue as lack of it can cause death, disease, and international tension. Furthermore, efficient water filtration reduces the demand for energy, another national issue. The best current solution to clean water lies in reverse osmosis (RO) membranes that remove salts from water with applied pressure, but widely used polymeric membrane technology is energy intensive and produces water depleted in useful electrolytes. Furthermore incremental improvements, based on engineering solutions rather than new materials, have yielded only modest gains in performance over the last 25 years. We have pursued a creative and innovative new approach to membrane design and development for cheap desalination membranes by approaching the problem at the molecular level of pore design. Our inspiration comes from natural biological channels, which permit faster water transport than current reverse osmosis membranes and selectively pass healthy ions. Aiming for an order-of-magnitude improvement over mature polymer technology carries significant inherent risks. The success of our fundamental research effort lies in our exploiting, extending, and integrating recent advances by our team in theory, modeling, nano-fabrication and platform development. A combined theoretical and experimental platform has been developed to understand the interplay between water flux and ion rejection in precisely-defined nano-channels. Our innovative functionalization of solid state nanoporous membranes with organic protein-mimetic polymers achieves 3-fold improvement in water flux over commercial RO membranes and has yielded a pending patent and industrial interest. Our success has generated useful contributions to energy storage, nanoscience, and membrane technology research and development important for national health and prosperity.

  20. Hydrodynamic Collective Effects of Active Protein Machines in Solution and Lipid Bilayers

    E-Print Network [OSTI]

    Alexander Mikhailov; Raymond Kapral

    2015-03-09

    The cytoplasm and biomembranes in biological cells contain large numbers of proteins that cyclically change their shapes. They are molecular machines that can function as molecular motors or carry out many other tasks in the cell. We analyze the effects that hydrodynamic flows induced by active proteins have on other passive molecules in solution or membranes. We show that the diffusion constants of passive particles are enhanced substantially. Furthermore, when gradients of active proteins are present, a chemotaxis-like drift of passive particles takes place. In lipid bilayers, the effects are strongly nonlocal, so that active inclusions in the membrane contribute to diffusion enhancement and the drift. The results indicate that the transport properties of passive particles in systems containing active proteins machines operating under nonequilibrium conditions differ from their counterparts in systems at thermal equilibrium.

  1. NMR Observable-Based Structure Refinement of DAP12-NKG2C Activating Immunoreceptor Complex in Explicit Membranes

    E-Print Network [OSTI]

    Cheng, Xi; Im, Wonpil

    2012-04-04

    NMR observables, such as NOE-based distance measurements, are increasingly being used to characterize membrane protein structures. However, challenges in membrane protein NMR studies often yield a relatively small number ...

  2. Thermodynamics and Structure of Peptide-Aggregates at Membrane Surfaces

    E-Print Network [OSTI]

    Quake, Stephen R.

    Thermodynamics and Structure of Peptide- Aggregates at Membrane Surfaces INAUGURALDISSERTATION zur. Introduction 01 1.1 ­ Thermodynamics of Protein Aggregation 01 1.2 ­ Formation of Protein Aggregates 03 1 and P-glycoprotein: Connecting Thermodynamics and Membrane Structure with Functional Activity 23 3

  3. Fuel cell water transport

    DOE Patents [OSTI]

    Vanderborgh, Nicholas E. (Los Alamos, NM); Hedstrom, James C. (Los Alamos, NM)

    1990-01-01

    The moisture content and temperature of hydrogen and oxygen gases is regulated throughout traverse of the gases in a fuel cell incorporating a solid polymer membrane. At least one of the gases traverses a first flow field adjacent the solid polymer membrane, where chemical reactions occur to generate an electrical current. A second flow field is located sequential with the first flow field and incorporates a membrane for effective water transport. A control fluid is then circulated adjacent the second membrane on the face opposite the fuel cell gas wherein moisture is either transported from the control fluid to humidify a fuel gas, e.g., hydrogen, or to the control fluid to prevent excess water buildup in the oxidizer gas, e.g., oxygen. Evaporation of water into the control gas and the control gas temperature act to control the fuel cell gas temperatures throughout the traverse of the fuel cell by the gases.

  4. Quantifying the Diffusion of a Fluid through Membranes by Remote Detection MRI

    E-Print Network [OSTI]

    Telkki, Ville-Veikko; Hilty, Christian; Garcia, Sandra; Harel, Elad; Pines, Alexander

    2008-01-01

    membrane diffusion and transport in intact systems of technological importance, such as fuel cells and gas separationgas separation (3), or metabolism (4). Present methods for the characterization of diffusion across membranes

  5. Elementary tetrahelical protein design for diverse oxidoreductase...

    Office of Scientific and Technical Information (OSTI)

    solar (fuels), photosynthesis (natural and artificial), biofuels (including algae and biomass), bio-inspired, charge transport, membrane, synthesis (novel materials), synthesis...

  6. Proton conducting ceramic membranes for hydrogen separation

    DOE Patents [OSTI]

    Elangovan, S. (South Jordan, UT); Nair, Balakrishnan G. (Sandy, UT); Small, Troy (Midvale, UT); Heck, Brian (Salt Lake City, UT)

    2011-09-06

    A multi-phase proton conducting material comprising a proton-conducting ceramic phase and a stabilizing ceramic phase. Under the presence of a partial pressure gradient of hydrogen across the membrane or under the influence of an electrical potential, a membrane fabricated with this material selectively transports hydrogen ions through the proton conducting phase, which results in ultrahigh purity hydrogen permeation through the membrane. The stabilizing ceramic phase may be substantially structurally and chemically identical to at least one product of a reaction between the proton conducting phase and at least one expected gas under operating conditions of a membrane fabricated using the material. In a barium cerate-based proton conducting membrane, one stabilizing phase is ceria.

  7. Microcomposite Fuel Cell Membranes

    Broader source: Energy.gov [DOE]

    Summary of microcomposite fuel cell membrane work presented to the High Temperature Membrane Working Group Meeting, Orlando FL, October 17, 2003

  8. Synthesis of UV-absorbing carrier ampholytes for characterization of isoelectric membranes 

    E-Print Network [OSTI]

    Hwang, Ann

    2006-10-30

    Isoelectric focusing is one of the most important techniques in protein separations. Preparative-scale isoelectric separations often use buffering membranes (isoelectric membranes), but there are no good known methods for the characterization...

  9. Si Nanopores Development for External Control of Transport of Biomolecules

    SciTech Connect (OSTI)

    Ileri, N; Tringe, J; Letant, S; Palozoglu, A; Stroeve, P; Faller, R

    2008-06-13

    Nazar Ileri has been involved in an independent, multidisciplinary effort to create a new class of molecular sieves for proteins and viruses. Her experimental work has been performed concurrently at two campuses, LLNL and UC Davis, while theoretical components have been largely accomplished at UC Davis. As will be described, the devices she is creating have great potential to improve very significantly the efficiency and selectivity of molecular transport over what is presently available from state-of-the-art membranes. Our biotechnology training program is based on an integrated study of the transport of biomolecules through conically-shaped, nanoporous silicon membranes. The overall objective of this effort is to demonstrate an efficient, highly selective membrane technology that is manufacturable for macroscopic areas and can be employed in sensing, diagnostic and biomedical applications. Our specific aims are to (1) fabricate and characterize the physical characteristics of the membranes, (2) to demonstrate their utility for molecular transport and separation, and (3) to develop models that will facilitate understanding of these devices as well as improved performance of the next generation of devices. We have proposed that the conical pores have superior performance characteristics compared to other porous filters. To study this hypothesis, complementary approaches from different disciplines, such as membrane synthesis, experiment, and molecular simulation need to be combined. This provides an ideal training environment for a future leader in biotechnology. Hence, for this study, Nazar Ileri has started to carry out a full range of experimental and theoretical investigations under our guidance. First, she has begun fabrication of filters with conical/pyramidal pores. She characterized the pores by AFM and SEM, and analyzed the images using wavelets and other mathematical tools. She has also started to conduct biomolecule transport experiments to compare the efficiency of fabricated filters vs. state-of-the-art commercial polycarbonate track-etched (PCTE) membranes. Finally, she has performed preliminary molecular calculations to investigate the operating principles of such systems and she has obtained results which she will present at the international 'Nanostructured materials, membrane modeling and simulation' workshop in Greece.

  10. Composite sensor membrane

    DOE Patents [OSTI]

    Majumdar, Arun (Orinda, CA); Satyanarayana, Srinath (Berkeley, CA); Yue, Min (Albany, CA)

    2008-03-18

    A sensor may include a membrane to deflect in response to a change in surface stress, where a layer on the membrane is to couple one or more probe molecules with the membrane. The membrane may deflect when a target molecule reacts with one or more probe molecules.

  11. Co-evolution of primordial membranes and membrane proteins

    E-Print Network [OSTI]

    Steinhoff, Heinz-Jürgen

    , Russia 3 National Center for Biotechnology Information, National Library of Medicine, National Institutes-dependent (and tightly regulated) import and export of metabolites and polymers [1]. Despite the growing

  12. Active membrane having uniform physico-chemically functionalized ion channels

    DOE Patents [OSTI]

    Gerald, II, Rex E; Ruscic, Katarina J; Sears, Devin N; Smith, Luis J; Klingler, Robert J; Rathke, Jerome W

    2012-09-24

    The present invention relates to a physicochemically-active porous membrane for electrochemical cells that purports dual functions: an electronic insulator (separator) and a unidirectional ion-transporter (electrolyte). The electrochemical cell membrane is activated for the transport of ions by contiguous ion coordination sites on the interior two-dimensional surfaces of the trans-membrane unidirectional pores. One dimension of the pore surface has a macroscopic length (1 nm-1000 .mu.m) and is directed parallel to the direction of an electric field, which is produced between the cathode and the anode electrodes of an electrochemical cell. The membrane material is designed to have physicochemical interaction with ions. Control of the extent of the interactions between the ions and the interior pore walls of the membrane and other materials, chemicals, or structures contained within the pores provides adjustability of the ionic conductivity of the membrane.

  13. Membrane-based gas separation is promising for efficient propylene/propane (C3H6/C3H8) separation with low energy consumption and minimum environment impact. Two microporous inorganic membrane

    E-Print Network [OSTI]

    Membrane-based gas separation is promising for efficient propylene/propane (C3H6/C3H8) separation selectivity of ~30. The gas transport and separation properties of CMS membrane are membrane thickness thermal and chemical stability. Application of these membranes into C3H6/C3H8 separation has not been well

  14. A Mechanistic Study of Chemically Modified Inorganic Membranes for Gas and Liquid Separations

    SciTech Connect (OSTI)

    Way, J Douglas

    2011-01-21

    This final report will summarize the progress made during the period August 1, 1993 - October 31, 2010 with support from DOE grant number DE-FG03-93ER14363. The objectives of the research have been to investigate the transport mechanisms in micro- and mesoporous, metal oxide membranes and to examine the relationship between the microstructure of the membrane, the membrane surface chemistry, and the separation performance of the membrane. Examples of the membrane materials under investigation are the microporous silica hollow fiber membrane manufactured by PPG Industries, chemically modified mesoporous oxide membranes, and polymer membranes containing microporous oxides (mixed matrix membranes). Analytical techniques such as NMR, FTIR and Raman spectroscopy, thermal analysis, and gas adsorption were used to investigate membrane microstructure and to probe the chemical interactions occurring at the gas-membrane interface.

  15. Exploiting gene deletion fitness effects in yeast to understand the modular architecture of protein complexes under different growth conditions

    E-Print Network [OSTI]

    Pache, Roland A; Babu, M Madan; Aloy, Patrick

    2009-07-18

    with respect to protein complexes has not yet been systematically carried out. Such study is cru- cial to improve our understanding of living systems, sim- ply because most major cellular processes, such as DNA transcription, translation, metabolism... 1 complex, which is part of the electron transport chain and participates in establishing a proton gradient across the mitochondrial inner membrane, and the F0/F1 ATP synthase, which finally uses that gradient for the genera- tion of ATP. In order...

  16. Glycosyl-phosphatidylinositol (GPI)-anchored membrane association of the porcine reproductive and respiratory syndrome virus GP4 glycoprotein and its co-localization with CD163 in lipid rafts

    SciTech Connect (OSTI)

    Du, Yijun [Department of Pathobiology, University of Illinois at Urbana-Champaign, 2001 South Lincoln Ave, Urbana, IL 61802 (United States) [Department of Pathobiology, University of Illinois at Urbana-Champaign, 2001 South Lincoln Ave, Urbana, IL 61802 (United States); Shandong Key Laboratory of Animal Disease Control and Breeding, Institute of Animal Science and Veterinary Medicine, Shandong Academy of Agricultural Sciences, Jinan (China); Pattnaik, Asit K. [School of Veterinary Medicine and Biomedical Sciences and the Nebraska Center for Virology, University of Nebraska-Lincoln, Lincoln, NE 68583-0900 (United States)] [School of Veterinary Medicine and Biomedical Sciences and the Nebraska Center for Virology, University of Nebraska-Lincoln, Lincoln, NE 68583-0900 (United States); Song, Cheng [Department of Pathobiology, University of Illinois at Urbana-Champaign, 2001 South Lincoln Ave, Urbana, IL 61802 (United States)] [Department of Pathobiology, University of Illinois at Urbana-Champaign, 2001 South Lincoln Ave, Urbana, IL 61802 (United States); Yoo, Dongwan, E-mail: dyoo@illinois.edu [Department of Pathobiology, University of Illinois at Urbana-Champaign, 2001 South Lincoln Ave, Urbana, IL 61802 (United States)] [Department of Pathobiology, University of Illinois at Urbana-Champaign, 2001 South Lincoln Ave, Urbana, IL 61802 (United States); Li, Gang, E-mail: dyoo@illinois.edu [Department of Pathobiology, University of Illinois at Urbana-Champaign, 2001 South Lincoln Ave, Urbana, IL 61802 (United States) [Department of Pathobiology, University of Illinois at Urbana-Champaign, 2001 South Lincoln Ave, Urbana, IL 61802 (United States); Institute of Animal Science and Veterinary Medicine, Chinese Academy of Agricultural Sciences, Beijing (China)

    2012-03-01

    The porcine reproductive and respiratory syndrome virus (PRRSV) glycoprotein 4 (GP4) resembles a typical type I membrane protein in its structure but lacks a hydrophilic tail at the C-terminus, suggesting that GP4 may be a lipid-anchored membrane protein. Using the human decay-accelerating factor (DAF; CD55), a known glycosyl-phosphatidylinositol (GPI) lipid-anchored protein, chimeric constructs were made to substitute the GPI-anchor domain of DAF with the putative lipid-anchor domain of GP4, and their membrane association and lipase cleavage were determined in cells. The DAF-GP4 fusion protein was transported to the plasma membrane and was cleaved by phosphatidylinositol-specific phospholipase C (PI-PLC), indicating that the C-terminal domain of GP4 functions as a GPI anchor. Mutational studies for residues adjacent to the GPI modification site and characterization of respective mutant viruses generated from infectious cDNA clones show that the ability of GP4 for membrane association corresponded to virus viability and growth characteristics. The residues T158 ({omega} - 2, where {omega} is the GPI moiety at E160), P159 ({omega} - 1), and M162 ({omega} + 2) of GP4 were determined to be important for virus replication, with M162 being of particular importance for virus infectivity. The complete removal of the peptide-anchor domain in GP4 resulted in a complete loss of virus infectivity. The depletion of cholesterol from the plasma membrane of cells reduced the virus production, suggesting a role of lipid rafts in PRRSV infection. Remarkably, GP4 was found to co-localize with CD163 in the lipid rafts on the plasma membrane. Since CD163 has been reported as a cellular receptor for PRRSV and GP4 has been shown to interact with this receptor, our data implicates an important role of lipid rafts during entry of the virus.

  17. Role of Water States on Water Uptake and Proton Transport in Nafion using Molecular Simulations and Bimodal Network

    E-Print Network [OSTI]

    Hwang, Gi Suk

    2013-01-01

    of novel sulfonated polyimides from 2,2’-bis(4-aminophenoxy)structure of sul- fonated polyimide membranes on transport

  18. Radio-Frequency Rectification on Membrane Bound Pores

    E-Print Network [OSTI]

    Sujatha Ramachandran; Robert H. Blick; Daniel W. van der Weide

    2007-09-12

    We present measurements on direct radio-frequency pumping of ion channels and pores bound in bilipid membranes. We make use of newly developed microcoaxes, which allow delivering the high frequency signal in close proximity to the membrane bound proteins and ion channels. We find rectification of the radio-frequency signal, which is used to pump ions through the channels and pores.

  19. Sartobind Epoxy 75 A Microporous Coupling Membrane for Affinity Chromatography

    E-Print Network [OSTI]

    Lebendiker, Mario

    ). Since thiol groups are better nucleophiles than amine and hydroxyl groups, epoxy-activated supports can to create an affinity Membrane Adsorber. Any molecule containing amino-, hydroxyl- or thiol-groups may by an ether, amine or thioether linkage between a given protein and the membrane forms an affinity

  20. Dialysis on microchips using thin porous polymer membranes

    DOE Patents [OSTI]

    Singh, Anup K. (San Francisco, CA); Kirby, Brian J. (San Francisco, CA); Shepodd, Timothy J. (Livermore, CA)

    2007-09-04

    Laser-induced phase-separation polymerization of a porous acrylate polymer is used for in-situ fabrication of dialysis membranes inside glass microchannels. A shaped 355 nm laser beam is used to produce a porous polymer membrane with a thickness of about 15 .mu.m, which bonds to the glass microchannel and form a semi-permeable membrane. Differential permeation through a membrane formed with pentaerythritol triacrylate was observed and quantified by comparing the response of the membrane to fluorescein and fluorescently tagging 200 nm latex microspheres. Differential permeation was observed and quantified by comparing the response to rhodamine 560 and lactalbumin protein in a membrane formed with SPE-methylene bisacrylamide. The porous membranes illustrate the capability for the present technique to integrate sample cleanup into chip-based analysis systems.

  1. Method for dialysis on microchips using thin porous polymer membrane

    DOE Patents [OSTI]

    Singh, Anup K. (San Francisco, CA); Kirby, Brian J. (San Francisco, CA); Shepodd, Timothy J. (Livermore, CA)

    2009-05-19

    Laser-induced phase-separation polymerization of a porous acrylate polymer is used for in-situ fabrication of dialysis membranes inside glass microchannels. A shaped 355 nm laser beam is used to produce a porous polymer membrane with a thickness of about 15 .mu.m, which bonds to the glass microchannel and forms a semi-permeable membrane. Differential permeation through a membrane formed with pentaerythritol triacrylate was observed and quantified by comparing the response of the membrane to fluorescein and fluorescently tagging 200 nm latex microspheres. Differential permeation was observed and quantified by comparing the response to rhodamine 560 and lactalbumin protein in a membrane formed with SPE-methylene bisacrylamide. The porous membranes illustrate the capability for the present technique to integrate sample cleanup into chip-based analysis systems.

  2. Membrane fluctuations near a plane rigid surface Oded Farago

    E-Print Network [OSTI]

    Farago, Oded

    barrier to prevent proteins, ions, and metabolites from leaking out of the cell and unwanted toxins from- functional membranes supported by solid interfaces semi- conductors, metals, plastics provide new classes

  3. Alkaline membrane fuel cells with in-situ cross-linked ionomers Yongjun Leng a

    E-Print Network [OSTI]

    optimization is needed for the commercialization of alkaline membrane fuel cell (AMFC) technologiesAlkaline membrane fuel cells with in-situ cross-linked ionomers Yongjun Leng a , Lizhu Wang b membrane fuel cell (AMFC) in-situ cross-linking ionomer net water transport coefficient A B S T R A C

  4. Indirect determination of zeta potential at high ionic strength: Specific application to semipermeable polymeric membranes

    E-Print Network [OSTI]

    reserved. 1. Introduction Membranes are rapidly becoming the leading separation method in a broad range and gas industry [6,12,29,30]. The fouling propensity of RO, NF, and FO membranes and mass transport to semipermeable polymeric membranes Bryan D. Coday a , Thomas Luxbacher b , Amy E. Childress c , Nohemi Almaraz

  5. Composite zeolite membranes

    DOE Patents [OSTI]

    Nenoff, Tina M. (Albuquerque, NM); Thoma, Steven G. (Albuquerque, NM); Ashley, Carol S. (Albuquerque, NM); Reed, Scott T. (Albuquerque, NM)

    2002-01-01

    A new class of composite zeolite membranes and synthesis techniques therefor has been invented. These membranes are essentially defect-free, and exhibit large levels of transmembrane flux and of chemical and isotopic selectivity.

  6. Supported inorganic membranes

    DOE Patents [OSTI]

    Sehgal, Rakesh (Albuquerque, NM); Brinker, Charles Jeffrey (Albuquerque, NM)

    1998-01-01

    Supported inorganic membranes capable of molecular sieving, and methods for their production, are provided. The subject membranes exhibit high flux and high selectivity. The subject membranes are substantially defect free and less than about 100 nm thick. The pores of the subject membranes have an average critical pore radius of less than about 5 .ANG., and have a narrow pore size distribution. The subject membranes are prepared by coating a porous substrate with a polymeric sol, preferably under conditions of low relative pressure of the liquid constituents of the sol. The coated substrate is dried and calcined to produce the subject supported membrane. Also provided are methods of derivatizing the surface of supported inorganic membranes with metal alkoxides. The subject membranes find use in a variety of applications, such as the separation of constituents of gaseous streams, as catalysts and catalyst supports, and the like.

  7. Hybrid adsorptive membrane reactor

    DOE Patents [OSTI]

    Tsotsis, Theodore T. (Huntington Beach, CA); Sahimi, Muhammad (Altadena, CA); Fayyaz-Najafi, Babak (Richmond, CA); Harale, Aadesh (Los Angeles, CA); Park, Byoung-Gi (Yeosu, KR); Liu, Paul K. T. (Lafayette Hill, PA)

    2011-03-01

    A hybrid adsorbent-membrane reactor in which the chemical reaction, membrane separation, and product adsorption are coupled. Also disclosed are a dual-reactor apparatus and a process using the reactor or the apparatus.

  8. Membrane Technology Workshop

    Broader source: Energy.gov [DOE]

    At the Membrane Technology Workshop (held July 24, 2012, in Rosemont, IL), stakeholders from industry and academia explored the status of membrane research and development (R&D). Participants ...

  9. Low doses of ochratoxin A upregulate the protein expression of organic anion transporters Oat1, Oat2, Oat3 and Oat5 in rat kidney cortex

    SciTech Connect (OSTI)

    Zlender, Vilim; Breljak, Davorka; Ljubojevic, Marija; Flajs, Dubravka; Balen, Daniela; Brzica, Hrvoje; Domijan, Ana-Marija; Peraica, Maja; Fuchs, Radovan; Anzai, Naohiko; Sabolic, Ivan

    2009-09-15

    Mycotoxin ochratoxin A (OTA) is nephrotoxic in various animal species. In rodents, OTA intoxication impairs various proximal tubule (PT) functions, including secretion of p-aminohippurate (PAH), possibly via affecting the renal organic anion (OA) transporters (Oat). However, an effect of OTA on the activity/expression of specific Oats in the mammalian kidney has not been reported. In this work, male rats were gavaged various doses of OTA every 2nd day for 10 days, and in their kidneys we studied: tubule integrity by microscopy, abundance of basolateral (rOat1, rOat3) and brush-border (rOat2, rOat5) rOat proteins by immunochemical methods, and expression of rOats mRNA by RT-PCR. The OTA treatment caused: a) dose-dependent damage of the cells in S3 segments of medullary rays, b) dual effect upon rOats in PT: low doses (50-250 {mu}g OTA/kg b.m.) upregulated the abundance of all rOats, while a high dose (500 {mu}g OTA/kg b.m.) downregulated the abundance of rOat1, and c) unchanged mRNA expression for all rOats at low OTA doses, and its downregulation at high OTA dose. Changes in the expression of renal Oats were associated with enhanced OTA accumulation in tissue and excretion in urine, whereas the indicators of oxidative stress either remained unchanged (malondialdehyde, glutathione, 8-hydroxydeoxyguanosine) or became deranged (microtubules). While OTA accumulation and downregulation of rOats in the kidney are consistent with the previously reported impaired renal PAH secretion in rodents intoxicated with high OTA doses, the post-transcriptional upregulation of Oats at low OTA doses may contribute to OTA accumulation and development of nephrotoxicity.

  10. Membrane Technology Workshop

    Broader source: Energy.gov [DOE]

    Presentation by Charles Page (Air Products & Chemicals, Inc.) for the Membrane Technology Workshop held July 24, 2012

  11. Membrane Separations Research 

    E-Print Network [OSTI]

    Fair, J. R.

    1992-01-01

    been dominated by light gas separations and water purification. During this pioneering period, equipment containing the membrane suIfaces has been developed to a point where failures are minimal and the membranes themselves are sufficiently rugged... of separation technology, especially in the area of gas recovery and purification. The field has grown quite large and the literature is voluminous. There is now a North American Membrane Society and there has been for some years the Journal of Membrane...

  12. Membranes with Rotating Motors Peter Lenz,1

    E-Print Network [OSTI]

    Jülicher, Frank

    . These functions are medi- ated by specific proteins, which consume and convert energy. Thus, from a statistical, a theoretical nonequilibrium statistical physics approach has been developed to describe the shapes and fluctuations of membranes containing active pumps [2]. Experiments have been carried out which have confirmed

  13. Cadmium sulfide membranes

    DOE Patents [OSTI]

    Spanhel, Lubomir (Madison, WI); Anderson, Marc A. (Madison, WI)

    1992-07-07

    A method is described for the creation of novel q-effect cadmium sulfide membranes. The membranes are made by first creating a dilute cadmium sulfide colloid in aqueous suspension and then removing the water and excess salts therefrom. The cadmium sulfide membrane thus produced is luminescent at room temperature and may have application in laser fabrication.

  14. Hydrogen Bond Shaping of Membrane Protein Structure

    E-Print Network [OSTI]

    Cao, Zheng

    2013-01-01

    Energy of Amide Hydrogen Bond Formation in Vacuum, in Water, andEnergy of Amide Hydrogen Bond Formation in Vacuum, in Water, andto water is dependent on the zero-point energies, i.e. the

  15. Hydrogen Bond Shaping of Membrane Protein Structure

    E-Print Network [OSTI]

    Cao, Zheng

    2013-01-01

    Almost no signal for the hydroxyl proton was detectedfull deuteration at the hydroxyl group. Acetonitrile and

  16. A survey of integral ?-helical membrane proteins

    E-Print Network [OSTI]

    2009-01-01

    in vertebrates. Annu Rev Genomics Hum Genet 6:123–142 7.Evolutionary and functional genomics of the Archaea. CurrJ Struct Funct Genomics (2009) 10:269–280 DOI

  17. Hydrogen Bond Shaping of Membrane Protein Structure

    E-Print Network [OSTI]

    Cao, Zheng

    2013-01-01

    domain from KvAP. J Mol Biol 403:591– 11. LiWang AC, Bax A (domain from KvAP. J Mol Biol 403:591– CHAPTER 2 SHIFTING

  18. Lipidic phase membrane protein serial femtosecond crystallography

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach Home Room NewsInformationJesse BergkampCenter (LMI-EFRC) ProximityCenterLee Facultya A B C D

  19. Exploring transport and phase behavior in nanoporous carbon materials

    E-Print Network [OSTI]

    Shimizu, Steven (Steven Franklin Esau)

    2015-01-01

    Understanding transport and phase behavior in nanopores has a substantial impact on applications involving membrane fabrication, single-molecule detection, oil reservoir modeling, and drug delivery. While transport and ...

  20. EFFECT OF COMPRESSION ON CONDUCTIVITY AND MORPHOLOGY OF PFSA MEMBRANES

    SciTech Connect (OSTI)

    Kusoglu, Ahmet; Weber, Adam; Jiang, Ruichin; Gittleman, Craig

    2011-07-20

    Polymer-Electrolyte-Fuel-Cells (PEFCs) are promising candidates for powering vehicles and portable devices using renewable-energy sources. The core of a PEFC is the solid electrolyte membrane that conducts protons from anode to cathode, where water is generated. The conductivity of the membrane, however, depends on the water content of the membrane, which is strongly related to the cell operating conditions. The membrane and other cell components are typically compressed to minimize various contact resistances. Moreover, the swelling of a somewhat constrained membrane in the cell due to the humidity changes generates additional compressive stresses in the membrane. These external stresses are balanced by the internal swelling pressure of the membrane and change the swelling equilibrium. It was shown using a fuel-cell setup that compression could reduce the water content of the membrane or alter the cell resistance. Nevertheless, the effect of compression on the membrane’s transport properties is yet to be understood, as well as its implications in the structure-functions relationships of the membrane. We previously studied, both experimentally and theoretically, how compression affects the water content of the membrane.6 However, more information is required the gain a fundamental understanding of the compression effects. In this talk, we present the results of our investigation on the in-situ conductivity of the membrane as a function of humidity and cell compression pressure. Moreover, to better understand the morphology of compressed membrane, small-angle X-ray-scattering (SAXS) experiments were performed. The conductivity data is then analyzed by investigating the size of the water domains of the compressed membrane determined from the SAXS measurements.

  1. Method for voltage-gated protein fractionation

    DOE Patents [OSTI]

    Hatch, Anson (Tracy, CA); Singh, Anup K. (Danville, CA)

    2012-04-24

    We report unique findings on the voltage dependence of protein exclusion from the pores of nanoporous polymer exclusion membranes. The pores are small enough that proteins are excluded from passage with low applied electric fields, but increasing the field enables proteins to pass through. The requisite field necessary for a change in exclusion is protein-specific with a correlation to protein size. The field-dependence of exclusion is important to consider for preconcentration applications. The ability to selectively gate proteins at exclusion membranes is also a promising means for manipulating and characterizing proteins. We show that field-gated exclusion can be used to selectively remove proteins from a mixture, or to selectively trap protein at one exclusion membrane in a series.

  2. Gene Recruitment of the Activated INO1 Locus to the Nuclear Membrane

    E-Print Network [OSTI]

    Walter, Peter

    Gene Recruitment of the Activated INO1 Locus to the Nuclear Membrane Jason H. Brickner* , Peter that activation of INO1 occurs at the nuclear membrane and requires the integral membrane protein Scs2. Scs2, the gene is recruited to the nuclear periphery upon transcriptional activation. Recruitment requires

  3. GM1 structure determines SV40-induced membrane invagination and infection

    E-Print Network [OSTI]

    Sens, Pierre

    ARTICLES GM1 structure determines SV40-induced membrane invagination and infection Helge Ewers1 to the carbohydrate moiety of GM1 gangliosides in the host cell plasma membrane through pentameric VP1 capsid proteins as isolated pentameric VP1) with GM1 is itself sufficient to induce dramatic membrane curvature that leads

  4. Binding kinetics of membrane-anchored receptors and ligands: molecular dynamics simulations and theory

    E-Print Network [OSTI]

    Jinglei Hu; Guang-Kui Xu; Reinhard Lipowsky; Thomas R. Weikl

    2015-11-24

    The adhesion of biological membranes is mediated by the binding of membrane-anchored receptor and ligand proteins. Central questions are how the binding kinetics of these proteins is affected by the membranes and by the membrane anchoring of the proteins. In this article, we (i) present detailed data for the binding of membrane-anchored proteins from coarse-grained molecular dynamics simulations, and (ii) provide a theory that describes how the binding kinetics depends on the average separation and thermal roughness of the adhering membranes, and on the anchoring, lengths, and length variations of the proteins. An important element of our theory is the tilt of bound receptor-ligand complexes and transition-state complexes relative to the membrane normals. This tilt results from an interplay of the anchoring energy and rotational entropy of the complexes and facilitates the formation of receptor-ligand bonds at membrane separations smaller than the preferred separation for binding. In our simulations, we have considered both lipid-anchored and transmembrane receptor and ligand proteins. We find that the binding equilibrium constant and binding on-rate constant of lipid-anchored proteins are considerably smaller than the binding constant and on-rate constant of rigid transmembrane proteins with identical binding domains.

  5. Substituted polyacetylene separation membrane

    DOE Patents [OSTI]

    Pinnau, Ingo (Palo Alto, CA); Morisato, Atsushi (Tokyo, JP)

    1998-01-13

    A separation membrane useful for gas separation, particularly separation of C.sub.2+ hydrocarbons from natural gas. The invention encompasses the membrane itself, methods of making it and processes for using it. The membrane comprises a polymer having repeating units of a hydrocarbon-based, disubstituted polyacetylene, having the general formula: ##STR1## wherein R.sub.1 is chosen from the group consisting of C.sub.1 -C.sub.4 alkyl and phenyl, and wherein R.sub.2 is chosen from the group consisting of hydrogen and phenyl. In the most preferred embodiment, the membrane comprises poly(4-methyl-2-pentyne) ›PMP!. The membrane exhibits good chemical resistance and has super-glassy properties with regard to separating certain large, condensable permeant species from smaller, less-condensable permeant species. The membranes may also be useful in other fluid separations.

  6. Substituted polyacetylene separation membrane

    DOE Patents [OSTI]

    Pinnau, I.; Morisato, Atsushi

    1998-01-13

    A separation membrane is described which is useful for gas separation, particularly separation of C{sub 2+} hydrocarbons from natural gas. The invention encompasses the membrane itself, methods of making it and processes for using it. The membrane comprises a polymer having repeating units of a hydrocarbon-based, disubstituted polyacetylene, having the general formula shown in the accompanying diagram, wherein R{sub 1} is chosen from the group consisting of C{sub 1}-C{sub 4} alkyl and phenyl, and wherein R{sub 2} is chosen from the group consisting of hydrogen and phenyl. In the most preferred embodiment, the membrane comprises poly(4-methyl-2-pentyne) [PMP]. The membrane exhibits good chemical resistance and has super-glassy properties with regard to separating certain large, condensable permeant species from smaller, less-condensable permeant species. The membranes may also be useful in other fluid separations. 4 figs.

  7. Siloxane-grafted membranes

    DOE Patents [OSTI]

    Friesen, D.T.; Obligin, A.S.

    1989-10-31

    Composite cellulosic semipermeable membranes are disclosed which are the covalently bonded reaction product of an asymmetric cellulosic semipermeable membrane and a polysiloxane containing reactive functional group. The two reactants chemically bond by ether, ester, amide or acrylate linkages to form a siloxane-grafted cellulosic membrane having superior selectivity and flux stability. Selectivity may be enhanced by wetting the surface with a swelling agent such as water.

  8. Recent developments in proton exchange membranes for fuel cells

    SciTech Connect (OSTI)

    Devanathan, Ramaswami

    2008-07-23

    Proton exchange membranes (PEMs) that operate at temperatures above 120 °C are needed to avoid catalyst poisoning, speed up electrochemical reactions, simplify the design and reduce the cost of fuel cells. This review summarizes developments in PEMs over the last five years. In order to design new membranes for elevated temperature operation, one must understand the chemistry, morphology and dynamics of protons and small molecules in existing membranes. The integration of experiments with modeling and simulation can shed light on the hierarchical structure of the membrane and dynamical processes associated with molecular transport. Based on such a fundamental understanding, membranes can be modified by controlling the polymer chemistry and architecture or adding inorganic fillers that can retain water under low relative humidity conditions. In addition, the development of anhydrous membranes based on phosphoric acid doped polymers, ionic liquid-infused polymer gels and solid acids can enable fuel cell operation above 150 °C. Considerable work remains to be done to identify proton transport mechanisms in novel membranes and evaluate membrane durability under real world operating conditions.

  9. Modeling Feat Sheds Light on Protein Channel's Function

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    translocon channel (green), which is embedded in the cell membrane (yellow, white). Proteins that are inserted via the ribosome into the channel can either be laterally...

  10. Membrane Technology Workshop

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Page - Air Products & Chemicals, Inc. Chicago 24 July 2012 Modules & Vessels Membranes System Design: Pretreatment & Controls Three Critical Areas So Much Work Performance ...

  11. Anion exchange membrane

    DOE Patents [OSTI]

    Verkade, John G; Wadhwa, Kuldeep; Kong, Xueqian; Schmidt-Rohr, Klaus

    2013-05-07

    An anion exchange membrane and fuel cell incorporating the anion exchange membrane are detailed in which proazaphosphatrane and azaphosphatrane cations are covalently bonded to a sulfonated fluoropolymer support along with anionic counterions. A positive charge is dispersed in the aforementioned cations which are buried in the support to reduce the cation-anion interactions and increase the mobility of hydroxide ions, for example, across the membrane. The anion exchange membrane has the ability to operate at high temperatures and in highly alkaline environments with high conductivity and low resistance.

  12. Sustainable Transport

    E-Print Network [OSTI]

    Webber, Melvin

    2006-01-01

    THOUGHT PIECE Sustainable Transport by Melvin M. Webberwant to sustain any mode of transport only if we judge it todraconian in rejecting transport modes that have failed in

  13. EVALUATION OF PROTON-CONDUCTING MEMBRANES FOR USE IN A SULFUR-DIOXIDE DEPOLARIZED ELECTROLYZER

    SciTech Connect (OSTI)

    Hobbs, D.; Elvington, M.; Colon-Mercado, H.

    2009-11-11

    The chemical stability, sulfur dioxide transport, ionic conductivity, and electrolyzer performance have been measured for several commercially available and experimental proton exchange membranes (PEMs) for use in a sulfur dioxide depolarized electrolyzer (SDE). The SDE's function is to produce hydrogen by using the Hybrid Sulfur (HyS) Process, a sulfur based electrochemical/thermochemical hybrid cycle. Membrane stability was evaluated using a screening process where each candidate PEM was heated at 80 C in 60 wt. % H{sub 2}SO{sub 4} for 24 hours. Following acid exposure, chemical stability for each membrane was evaluated by FTIR using the ATR sampling technique. Membrane SO{sub 2} transport was evaluated using a two-chamber permeation cell. SO{sub 2} was introduced into one chamber whereupon SO{sub 2} transported across the membrane into the other chamber and oxidized to H{sub 2}SO{sub 4} at an anode positioned immediately adjacent to the membrane. The resulting current was used to determine the SO{sub 2} flux and SO{sub 2} transport. Additionally, membrane electrode assemblies (MEAs) were prepared from candidate membranes to evaluate ionic conductivity and selectivity (ionic conductivity vs. SO{sub 2} transport) which can serve as a tool for selecting membranes. MEAs were also performance tested in a HyS electrolyzer measuring current density versus a constant cell voltage (1V, 80 C in SO{sub 2} saturated 30 wt% H2SO{sub 4}). Finally, candidate membranes were evaluated considering all measured parameters including SO{sub 2} flux, SO{sub 2} transport, ionic conductivity, HyS electrolyzer performance, and membrane stability. Candidate membranes included both PFSA and non-PFSA polymers and polymer blends of which the non-PFSA polymers, BPVE-6F and PBI, showed the best selectivity.

  14. Integrated Ceramic Membrane System for Hydrogen Production

    SciTech Connect (OSTI)

    Schwartz, Joseph; Lim, Hankwon; Drnevich, Raymond

    2010-08-05

    Phase I was a technoeconomic feasibility study that defined the process scheme for the integrated ceramic membrane system for hydrogen production and determined the plan for Phase II. The hydrogen production system is comprised of an oxygen transport membrane (OTM) and a hydrogen transport membrane (HTM). Two process options were evaluated: 1) Integrated OTM-HTM reactor – in this configuration, the HTM was a ceramic proton conductor operating at temperatures up to 900°C, and 2) Sequential OTM and HTM reactors – in this configuration, the HTM was assumed to be a Pd alloy operating at less than 600°C. The analysis suggested that there are no technical issues related to either system that cannot be managed. The process with the sequential reactors was found to be more efficient, less expensive, and more likely to be commercialized in a shorter time than the single reactor. Therefore, Phase II focused on the sequential reactor system, specifically, the second stage, or the HTM portion. Work on the OTM portion was conducted in a separate program. Phase IIA began in February 2003. Candidate substrate materials and alloys were identified and porous ceramic tubes were produced and coated with Pd. Much effort was made to develop porous substrates with reasonable pore sizes suitable for Pd alloy coating. The second generation of tubes showed some improvement in pore size control, but this was not enough to get a viable membrane. Further improvements were made to the porous ceramic tube manufacturing process. When a support tube was successfully coated, the membrane was tested to determine the hydrogen flux. The results from all these tests were used to update the technoeconomic analysis from Phase I to confirm that the sequential membrane reactor system can potentially be a low-cost hydrogen supply option when using an existing membrane on a larger scale. Phase IIB began in October 2004 and focused on demonstrating an integrated HTM/water gas shift (WGS) reactor to increase CO conversion and produce more hydrogen than a standard water gas shift reactor would. Substantial improvements in substrate and membrane performance were achieved in another DOE project (DE-FC26-07NT43054). These improved membranes were used for testing in a water gas shift environment in this program. The amount of net H2 generated (defined as the difference of hydrogen produced and fed) was greater than would be produced at equilibrium using conventional water gas shift reactors up to 75 psig because of the shift in equilibrium caused by continuous hydrogen removal. However, methanation happened at higher pressures, 100 and 125 psig, and resulted in less net H2 generated than would be expected by equilibrium conversion alone. An effort to avoid methanation by testing in more oxidizing conditions (by increasing CO2/CO ratio in a feed gas) was successful and net H2 generated was higher (40-60%) than a conventional reactor at equilibrium at all pressures tested (up to 125 psig). A model was developed to predict reactor performance in both cases with and without methanation. The required membrane area depends on conditions, but the required membrane area is about 10 ft2 to produce about 2000 scfh of hydrogen. The maximum amount of hydrogen that can be produced in a membrane reactor decreased significantly due to methanation from about 2600 scfh to about 2400 scfh. Therefore, it is critical to eliminate methanation to fully benefit from the use of a membrane in the reaction. Other modeling work showed that operating a membrane reactor at higher temperature provides an opportunity to make the reactor smaller and potentially provides a significant capital cost savings compared to a shift reactor/PSA combination.

  15. Polymide gas separation membranes

    DOE Patents [OSTI]

    Ding, Yong; Bikson, Benjamin; Nelson, Joyce Katz

    2004-09-14

    Soluble polyamic acid salt (PAAS) precursors comprised of tertiary and quaternary amines, ammonium cations, sulfonium cations, or phosphonium cations, are prepared and fabricated into membranes that are subsequently imidized and converted into rigid-rod polyimide articles, such as membranes with desirable gas separation properties. A method of enhancing solubility of PAAS polymers in alcohols is also disclosed.

  16. Microporous alumina ceramic membranes

    DOE Patents [OSTI]

    Anderson, Marc A. (Madison, WI); Sheng, Guangyao (Madison, WI)

    1993-01-01

    Several methods are disclosed for the preparation microporous alumina ceramic membranes. For the first time, porous alumina membranes are made which have mean pore sizes less than 100 Angstroms and substantially no pores larger than that size. The methods are based on improved sol-gel techniques.

  17. Membrane module assembly

    DOE Patents [OSTI]

    Kaschemekat, J.

    1994-03-15

    A membrane module assembly is described which is adapted to provide a flow path for the incoming feed stream that forces it into prolonged heat-exchanging contact with a heating or cooling mechanism. Membrane separation processes employing the module assembly are also disclosed. The assembly is particularly useful for gas separation or pervaporation. 2 figures.

  18. Membrane module assembly

    DOE Patents [OSTI]

    Kaschemekat, Jurgen (Palo Alto, CA)

    1994-01-01

    A membrane module assembly adapted to provide a flow path for the incoming feed stream that forces it into prolonged heat-exchanging contact with a heating or cooling mechanism. Membrane separation processes employing the module assembly are also disclosed. The assembly is particularly useful for gas separation or pervaporation.

  19. Microporous alumina ceramic membranes

    DOE Patents [OSTI]

    Anderson, M.A.; Guangyao Sheng.

    1993-05-04

    Several methods are disclosed for the preparation microporous alumina ceramic membranes. For the first time, porous alumina membranes are made which have mean pore sizes less than 100 Angstroms and substantially no pores larger than that size. The methods are based on improved sol-gel techniques.

  20. Multicomponent ballistic transport in narrow single wall carbon nanotubes: Analytic model and molecular dynamics simulations

    E-Print Network [OSTI]

    Adler, Joan

    online 27 January 2011) The transport of gas mixtures through molecular-sieve membranes such as narrow The transport of gas mixtures through molecular-sieve membranes and catalysts has been a subject of intensive inMulticomponent ballistic transport in narrow single wall carbon nanotubes: Analytic model

  1. MembraneScienceandTechnologyatUTwente MembraneNewsTwente

    E-Print Network [OSTI]

    Twente, Universiteit

    for water treatment, e.g. water purification, desalination, membrane bioreactors and waste water treatment purification - Drinking water prod. - Membrane bioreactors - Waste water treatment - Desalination Energy - Gas

  2. Membrane projection lithography

    SciTech Connect (OSTI)

    Burckel, David Bruce; Davids, Paul S; Resnick, Paul J; Draper, Bruce L

    2015-03-17

    The various technologies presented herein relate to a three dimensional manufacturing technique for application with semiconductor technologies. A membrane layer can be formed over a cavity. An opening can be formed in the membrane such that the membrane can act as a mask layer to the underlying wall surfaces and bottom surface of the cavity. A beam to facilitate an operation comprising any of implantation, etching or deposition can be directed through the opening onto the underlying surface, with the opening acting as a mask to control the area of the underlying surfaces on which any of implantation occurs, material is removed, and/or material is deposited. The membrane can be removed, a new membrane placed over the cavity and a new opening formed to facilitate another implantation, etching, or deposition operation. By changing the direction of the beam different wall/bottom surfaces can be utilized to form a plurality of structures.

  3. Novel, Ceramic Membrane System For Hydrogen Separation

    SciTech Connect (OSTI)

    Elangovan, S.

    2012-12-31

    Separation of hydrogen from coal gas represents one of the most promising ways to produce alternative sources of fuel. Ceramatec, teamed with CoorsTek and Sandia National Laboratories has developed materials technology for a pressure driven, high temperature proton-electron mixed conducting membrane system to remove hydrogen from the syngas. This system separates high purity hydrogen and isolates high pressure CO{sub 2} as the retentate, which is amenable to low cost capture and transport to storage sites. The team demonstrated a highly efficient, pressure-driven hydrogen separation membrane to generate high purity hydrogen from syngas using a novel ceramic-ceramic composite membrane. Recognizing the benefits and limitations of present membrane systems, the all-ceramic system has been developed to address the key technical challenges related to materials performance under actual operating conditions, while retaining the advantages of thermal and process compatibility offered by the ceramic membranes. The feasibility of the concept has already been demonstrated at Ceramatec. This project developed advanced materials composition for potential integration with water gas shift rectors to maximize the hydrogenproduction.

  4. Original article Flat ceramic membranes

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    with tubular ceramic membranes André GRANGEON, Philippe LESCOCHE* TAMI Industries, ZA les Laurons, 26110 Nyons membranes. The orig- inal intellectual concept is protected by two international patents. Strategically

  5. Nanoengineered membrane electrode assembly interface

    DOE Patents [OSTI]

    Song, Yujiang; Shelnutt, John A

    2013-08-06

    A membrane electrode structure suitable for use in a membrane electrode assembly (MEA) that comprises membrane-affixed metal nanoparticles whose formation is controlled by a photochemical process that controls deposition of the metal nanoparticles using a photocatalyst integrated with a polymer electrolyte membrane, such as an ionomer membrane. Impregnation of the polymer membrane with the photocatalyst prior to metal deposition greatly reduces the required amount of metal precursor in the deposition reaction solution by restricting metal reduction substantially to the formation of metal nanoparticles affixed on or near the surface of the polymer membrane with minimal formation of metallic particles not directly associated with the membrane.

  6. Crystal structure of the Alcanivorax borkumensis YdaH transporter reveals an unusual topology

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Bolla, Jani Reddy; Su, Chih-Chia; Delmar, Jared A.; Radhakrishnan, Abhijith; Kumar, Nitin; Chou, Tsung-Han; Long, Feng; Rajashankar, Kanagalaghatta R.; Yu, Edward W.

    2015-04-20

    The potential of the folic acid biosynthesis pathway as a target for the development of antibiotics has been clinically validated. However, many pathogens have developed resistance to these antibiotics, prompting a re-evaluation of potential drug targets within the pathway. The ydaH gene of Alcanivorax borkumensis encodes an integral membrane protein of the AbgT family of transporters for which no structural information was available. Here we report the crystal structure of A. borkumensis YdaH, revealing a dimeric molecule with an architecture distinct from other families of transporters. YdaH is a bowl-shaped dimer with a solvent-filled basin extending from the cytoplasm tomore »halfway across the membrane bilayer. Each subunit of the transporter contains nine transmembrane helices and two hairpins that suggest a plausible pathway for substrate transport. Further analyses also suggest that YdaH could act as an antibiotic efflux pump and mediate bacterial resistance to sulfonamide antimetabolite drugs.« less

  7. Catalytic nanoporous membranes

    DOE Patents [OSTI]

    Pellin, Michael J; Hryn, John N; Elam, Jeffrey W

    2013-08-27

    A nanoporous catalytic membrane which displays several unique features Including pores which can go through the entire thickness of the membrane. The membrane has a higher catalytic and product selectivity than conventional catalysts. Anodic aluminum oxide (AAO) membranes serve as the catalyst substrate. This substrate is then subjected to Atomic Layer Deposition (ALD), which allows the controlled narrowing of the pores from 40 nm to 10 nm in the substrate by deposition of a preparatory material. Subsequent deposition of a catalytic layer on the inner surfaces of the pores reduces pore sizes to less than 10 nm and allows for a higher degree of reaction selectivity. The small pore sizes allow control over which molecules enter the pores, and the flow-through feature can allow for partial oxidation of reactant species as opposed to complete oxidation. A nanoporous separation membrane, produced by ALD is also provided for use in gaseous and liquid separations. The membrane has a high flow rate of material with 100% selectivity. Also provided is a method for producing a catalytic membrane having flow-through pores and discreet catalytic clusters adhering to the inside surfaces of the pores.

  8. Computational and experimental study of nanoporous membranes for water desalination and decontamination.

    SciTech Connect (OSTI)

    Hickner, Michael A. (Penn State University, University Park, PA); Chinn, Douglas Alan (Sandia National Laboratories, Albuquerque, NM); Adalsteinsson, Helgi; Long, Kevin R. (Texas Tech University, Lubbock, TX); Kent, Michael Stuart (Sandia National Laboratories, Albuquerque, NM); Debusschere, Bert J.; Zendejas, Frank J.; Tran, Huu M.; Najm, Habib N.; Simmons, Blake Alexander

    2008-11-01

    Fundamentals of ion transport in nanopores were studied through a joint experimental and computational effort. The study evaluated both nanoporous polymer membranes and track-etched nanoporous polycarbonate membranes. The track-etched membranes provide a geometrically well characterized platform, while the polymer membranes are more closely related to ion exchange systems currently deployed in RO and ED applications. The experimental effort explored transport properties of the different membrane materials. Poly(aniline) membranes showed that flux could be controlled by templating with molecules of defined size. Track-etched polycarbonate membranes were modified using oxygen plasma treatments, UV-ozone exposure, and UV-ozone with thermal grafting, providing an avenue to functionalized membranes, increased wettability, and improved surface characteristic lifetimes. The modeling effort resulted in a novel multiphysics multiscale simulation model for field-driven transport in nanopores. This model was applied to a parametric study of the effects of pore charge and field strength on ion transport and charge exclusion in a nanopore representative of a track-etched polycarbonate membrane. The goal of this research was to uncover the factors that control the flux of ions through a nanoporous material and to develop tools and capabilities for further studies. Continuation studies will build toward more specific applications, such as polymers with attached sulfonate groups, and complex modeling methods and geometries.

  9. Novel membrane technology for green ethylene production.

    SciTech Connect (OSTI)

    Balachandran, U.; Lee, T. H.; Dorris, S. E.; Udovich, C. A.; Scouten, C. G.; Marshall, C. L.

    2008-01-01

    Ethylene is currently produced by pyrolysis of ethane in the presence of steam. This reaction requires substantial energy input, and the equilibrium conversion is thermodynamically limited. The reaction also produces significant amounts of greenhouse gases (CO and CO{sub 2}) because of the direct contact between carbon and steam. Argonne has demonstrated a new way to make ethylene via ethane dehydrogenation using a dense hydrogen transport membrane (HTM) to drive the unfavorable equilibrium conversion. Preliminary experiments show that the new approach can produce ethylene yields well above existing pyrolysis technology and also significantly above the thermodynamic equilibrium limit, while completely eliminating the production of greenhouse gases. With Argonne's approach, a disk-type dense ceramic/metal composite (cermet) membrane is used to produce ethylene by dehydrogenation of ethane at 850 C. The gas-transport membrane reactor combines a reversible chemical reaction with selective separation of one product species and leads to increased reactant conversion to the desired product. In an experiment ethane was passed over one side of the HTM membrane and air over the other side. The hydrogen produced by the dehydrogenation of ethane was removed and transported through the HTM to the air side. The air provided the driving force required for the transport of hydrogen through the HTM. The reaction between transported hydrogen and oxygen in air can provide the energy needed for the dehydrogenation reaction. At 850 C and 1-atm pressure, equilibrium conversion of ethane normally limits the ethylene yield to 64%, but Argonne has shown that an ethylene yield of 69% with a selectivity of 88% can be obtained under the same conditions. Coking was not a problem in runs extending over several weeks. Further improved HTM materials will lower the temperature required for high conversion at a reasonable residence time, while the lower temperature will suppress unwanted side reactions and prolong membrane life. With the Argonne approach, oxygen does not contact the ethane/ethylene stream, so oxidation products are not formed. Consequently, higher selectivity to ethylene and fewer by-products can be achieved. Some benefits are: (1) Simplifies overall product purification and processing schemes; (2) Results in greater energy efficiency; (3) Completely eliminates greenhouse gases from the reactor section; and (4) Lowers the cost of the 'back end' purification train, which accounts for about 70% of the capital cost of a conventional ethylene production unit.

  10. Cyclic membrane separation process

    DOE Patents [OSTI]

    Nemser, Stuart M.

    2005-05-03

    A cyclic process for controlling environmental emissions of volatile organic compounds (VOC) from vapor recovery in storage and dispensing operations of liquids maintains a vacuum in the storage tank ullage. In the first part of a two-part cyclic process ullage vapor is discharged through a vapor recovery system in which VOC are stripped from vented gas with a selectively gas permeable membrane. In the second part, the membrane is inoperative while gas pressure rises in the ullage. In one aspect of this invention, a vacuum is drawn in the membrane separation unit thus reducing overall VOC emissions.

  11. Cyclic membrane separation process

    DOE Patents [OSTI]

    Bowser, John

    2004-04-13

    A cyclic process for controlling environmental emissions of volatile organic compounds (VOC) from vapor recovery in storage and dispensing operations of liquids maintains a vacuum in the storage tank ullage. In one of a two-part cyclic process ullage vapor is discharged through a vapor recovery system in which VOC are stripped from vented gas with a selectively gas permeable membrane. In the other part, the membrane is inoperative while gas pressure rises in the ullage. Ambient air is charged to the membrane separation unit during the latter part of the cycle.

  12. Composite metal membrane

    DOE Patents [OSTI]

    Peachey, Nathaniel M. (Espanola, NM); Dye, Robert C. (Los Alamos, NM); Snow, Ronny C. (Los Alamos, NM); Birdsell, Stephan A. (Los Alamos, NM)

    1998-01-01

    A composite metal membrane including a first metal layer of Group IVB met or Group VB metals, the first metal layer sandwiched between two layers of an oriented metal of palladium, platinum or alloys thereof is provided together with a process for the recovery of hydrogen from a gaseous mixture including contacting a hydrogen-containing gaseous mixture with a first side of a nonporous composite metal membrane including a first metal of Group IVB metals or Group VB metals, the first metal layer sandwiched between two layers of an oriented metal of palladium, platinum or alloys thereof, and, separating hydrogen from a second side of the nonporous composite metal membrane.

  13. Composite metal membrane

    DOE Patents [OSTI]

    Peachey, N.M.; Dye, R.C.; Snow, R.C.; Birdsell, S.A.

    1998-04-14

    A composite metal membrane including a first metal layer of Group IVB met or Group VB metals, the first metal layer sandwiched between two layers of an oriented metal of palladium, platinum or alloys thereof is provided together with a process for the recovery of hydrogen from a gaseous mixture including contacting a hydrogen-containing gaseous mixture with a first side of a nonporous composite metal membrane including a first metal of Group IVB metals or Group VB metals, the first metal layer sandwiched between two layers of an oriented metal of palladium, platinum or alloys thereof, and, separating hydrogen from a second side of the nonporous composite metal membrane.

  14. Power-law scaling in protein synthesis of a stochastic regulon

    E-Print Network [OSTI]

    Emily Chapman-McQuiston; Chuck Yeung; X. L. Wu

    2008-08-07

    We investigate the protein expression pattern of the lamB gene in Escherichia coli LE392. The gene product LamB is an important membrane protein for maltose transport into cells but it is also exploited by bacteriophage lambda for infection. Although our bacterial population is clonal, stochastic gene expression leads to a majority population with a large receptor number and a minority population with a small receptor number. We find that the LamB receptor distribution p(n) of the small-n population is scale invariant with the exponent depending on growth conditions. A heuristic model is proposed that relates the observed exponent to the protein production rate.

  15. Gas Separation Using Membranes 

    E-Print Network [OSTI]

    Koros, W. J.; Paul, D. R.

    1984-01-01

    Commercial membrane-based gas separator systems based upon high-flux, asymmetric polysulfone hollow fibers were first introduced in 1977 by Monsanto. These systems were packaged in compact modules containing large amounts of permeation surface area...

  16. Fuel cell membrane humidification

    DOE Patents [OSTI]

    Wilson, Mahlon S. (Los Alamos, NM)

    1999-01-01

    A polymer electrolyte membrane fuel cell assembly has an anode side and a cathode side separated by the membrane and generating electrical current by electrochemical reactions between a fuel gas and an oxidant. The anode side comprises a hydrophobic gas diffusion backing contacting one side of the membrane and having hydrophilic areas therein for providing liquid water directly to the one side of the membrane through the hydrophilic areas of the gas diffusion backing. In a preferred embodiment, the hydrophilic areas of the gas diffusion backing are formed by sewing a hydrophilic thread through the backing. Liquid water is distributed over the gas diffusion backing in distribution channels that are separate from the fuel distribution channels.

  17. Orbifolding the Membrane Action

    E-Print Network [OSTI]

    Seiji Terashima; Futoshi Yagi

    2008-12-08

    We study a simple class of orbifolds of the N=6 Chern-Simons Matter theory proposed by Aharony, Bergman, Jafferis and Maldacena. They are considered as a world volume theory of membranes probing C^4/ (Z_k x Z_n) and include a new membrane theory with N=4 supersymmetries. We find that the moduli spaces of them are consistent with the fact that they probe C^4/ (Z_k x Z_n).

  18. Microprobes aluminosilicate ceramic membranes

    DOE Patents [OSTI]

    Anderson, Marc A. (2114 Chadbourne Ave., Madison, WI 53705); Sheng, Guangyao (45 N. Orchard St., Madison, WI 53715)

    1993-01-01

    Methods have been developed to make mixed alumina-silicate and aluminosilicate particulate microporous ceramic membranes. One method involves the making of separate alumina and silica sols which are then mixed. Another method involves the creation of a combined sol with aluminosilicate particles. The resulting combined alumina and silica membranes have high surface area, a very small pore size, and a very good temperature stability.

  19. Battery utilizing ceramic membranes

    DOE Patents [OSTI]

    Yahnke, Mark S. (Berkeley, CA); Shlomo, Golan (Haifa, IL); Anderson, Marc A. (Madison, WI)

    1994-01-01

    A thin film battery is disclosed based on the use of ceramic membrane technology. The battery includes a pair of conductive collectors on which the materials for the anode and the cathode may be spin coated. The separator is formed of a porous metal oxide ceramic membrane impregnated with electrolyte so that electrical separation is maintained while ion mobility is also maintained. The entire battery can be made less than 10 microns thick while generating a potential in the 1 volt range.

  20. Membrane separation of hydrocarbons

    DOE Patents [OSTI]

    Funk, Edward W. (Highland Park, IL); Kulkarni, Sudhir S. (Hoffman Estates, IL); Chang, Y. Alice (Des Plaines, IL)

    1986-01-01

    Mixtures of heavy oils and light hydrocarbons may be separated by passing the mixture over a polymeric membrane which comprises a polymer capable of maintaining its integrity in the presence of hydrocarbon compounds at temperature ranging from about ambient to about 100.degree. C. and pressures ranging from about 50 to about 1000 psi. The membranes which possess pore sizes ranging from about 10 to about 500 Angstroms are cast from a solvent solution and recovered.

  1. Composite membranes for fluid separations

    DOE Patents [OSTI]

    Blume, Ingo (Hengelo, NL); Peinemann, Klaus-Viktor (Reinbek, DE); Pinnau, Ingo (Austin, TX); Wijmans, Johannes G. (Menlo Park, CA)

    1991-01-01

    A method for designing and making composite membranes having a microporous support membrane coated with a permselective layer. The method involves calculating the minimum thickness of the permselective layer such that the selectivity of the composite membrane is close to the intrinsic selectivity of the permselective layer. The invention also provides high performance membranes with optimized properties.

  2. High Temperature Membrane Working Group

    Broader source: Energy.gov [DOE]

    This presentation provides an overview of the High Temperature Membrane Working Group Meeting in May 2007.

  3. Catalytic nanoporous membranes

    DOE Patents [OSTI]

    Pellin, Michael J. (Naperville, IL); Hryn, John N. (Naperville, IL); Elam, Jeffrey W. (Elmhurst, IL)

    2009-12-01

    A nanoporous catalytic membrane which displays several unique features including pores which can go through the entire thickness of the membrane. The membrane has a higher catalytic and product selectivity than conventional catalysts. Anodic aluminum oxide (AAO) membranes serve as the catalyst substrate. This substrate is then subjected to Atomic Layer Deposition (ALD), which allows the controlled narrowing of the pores from 40 nm to 10 nm in the substrate by deposition of a preparatory material. Subsequent deposition of a catalytic layer on the inner surfaces of the pores reduces pore sizes to less than 10 nm and allows for a higher degree of reaction selectivity. The small pore sizes allow control over which molecules enter the pores, and the flow-through feature can allow for partial oxidation of reactant species as opposed to complete oxidation. A nanoporous separation membrane, produced by ALD is also provided for use in gaseous and liquid separations. The membrane has a high flow rate of material with 100% selectivity.

  4. High temperature CO2 perm-selective membranes offer potential for uses in various processes for CO2 separation. Recently, efforts are reported on fabrication of dense ceramic-carbonate dual-phase

    E-Print Network [OSTI]

    separation. Recently, efforts are reported on fabrication of dense ceramic-carbonate dual-phase membranes on transport mechanism demonstrates that gas transport for ceramic- carbonate dual-phase membrane is rate and Characterization of Thin Ceramic-Carbonate Dual-Phase Membranes for Carbon Dioxide Separation Bo Lu Advisor: Jerry

  5. Direct numerical simulation of electroconvective instability and hysteretic current-voltage response of a permselective membrane

    E-Print Network [OSTI]

    Pham, Van Sang

    We present a systematic, multiscale, fully detailed numerical modeling for dynamics of fluid flow and ion transport covering Ohmic, limiting, and overlimiting current regimes in conductance of ion-selective membrane. By ...

  6. Reconstructing phonon mean-free-path contributions to thermal conductivity using nanoscale membranes

    E-Print Network [OSTI]

    Cuffe, John

    Knowledge of the mean-free-path distribution of heat-carrying phonons is key to understanding phonon-mediated thermal transport. We demonstrate that thermal conductivity measurements of thin membranes spanning a wide ...

  7. Influence of Ibuprofen on Phospholipid Membranes

    E-Print Network [OSTI]

    Jaksch, Sebastian; Koutsioubas, Alexandros; Mattauch, Stefan; Holderer, Olaf; Ivanova, Oxana; Frielinghaus, Henrich; Hertrich, Samira; Nickel, Bert

    2014-01-01

    Basic understanding of biological membranes is of paramount importance as these membranes comprise the very building blocks of life itself. Cells depend in their function on a range of properties of the membrane, which are important for the stability and function of the cell, information and nutrient transport, waste disposal and finally the admission of drugs into the cell and also the deflection of bacteria and viruses. We have investigated the influence of ibuprofen on the structure and dynamics of L-alpha-phosphatidylcholine (SoyPC) membranes by means of grazing incidence small-angle neutron scattering (GISANS), neutron reflectometry and grazing incidence neutron spin echo spectroscopy (GINSES). From the results of these experiments we were able to determine that ibuprofen induces a two-step structuring behavior in the SoyPC films, where the structure evolves from the purely lamellar phase for pure SoyPC over a superposition of two hexagonal phases to a purely hexago- nal phase at high concentrations. Add...

  8. Multi-block sulfonated poly(phenylene) copolymer proton exchange membranes

    DOE Patents [OSTI]

    Fujimoto, Cy H. (Albuquerque, NM); Hibbs, Michael (Albuquerque, NM); Ambrosini, Andrea (Albuquerque, NM)

    2012-02-07

    Improved multi-block sulfonated poly(phenylene) copolymer compositions, methods of making the same, and their use as proton exchange membranes (PEM) in hydrogen fuel cells, direct methanol fuel cells, in electrode casting solutions and electrodes. The multi-block architecture has defined, controllable hydrophobic and hydrophilic segments. These improved membranes have better ion transport (proton conductivity) and water swelling properties.

  9. Hydrogen separation membranes annual report for FY 2006.

    SciTech Connect (OSTI)

    Balachandran, U.; Chen, L.; Ciocco, M.; Doctor, R. D.; Dorris, S.E.; Emerson, J. E.; Fisher, B.; Lee, T. H.; Killmeyer, R. P.; Morreale,B.; Picciolo, J. J.; Siriwardane, R. V.; Song, S. J.

    2007-02-05

    The objective of this work is to develop dense ceramic membranes for separating hydrogen from other gaseous components in a nongalvanic mode, i.e., without using an external power supply or electrical circuitry. This goal of this project is to develop two types of dense ceramic membrane for producing hydrogen nongalvanically, i.e., without electrodes or external power supply, at commercially significant fluxes under industrially relevant operating conditions. The first type of membrane, hydrogen transport membranes (HTMs), will be used to separate hydrogen from gas mixtures such as the product streams from coal gasification, methane partial oxidation, and water-gas shift reactions. Potential ancillary uses of HTMs include dehydrogenation and olefin production, as well as hydrogen recovery in petroleum refineries and ammonia synthesis plants, the largest current users of deliberately produced hydrogen. The second type of membrane, oxygen transport membranes (OTMs), will produce hydrogen by nongalvanically removing oxygen that is generated when water dissociates at elevated temperatures. This report describes progress that was made during FY 2006 on the development of OTM and HTM materials.

  10. Think positively : the structural basis of cation-binding and coupling of the multidrug and toxic-compound Extrusion (MATE) transporter family

    E-Print Network [OSTI]

    He, Xiao

    2010-01-01

    plant homolog Nt- JAT1 transporting secondary metaboliteSecondary transport as an efficient membrane transport mechanism for plant secondary metabolites.of secondary metabolites. Curr. Opin. Plant Biol. 8, 301-

  11. Membranes and MEAs at Freezing Temperatures Thomas A. Zawodzinski, Jr.

    E-Print Network [OSTI]

    University Cleveland, Ohio #12;2 Freezing Fuel Cells: Impact on MEAS Below 0oC ·Transport processesMembranes and MEAs at Freezing Temperatures Thomas A. Zawodzinski, Jr. Case Western Reserve' of Water in Proton Conductors ? Freezing (bulk), bound freezable, bound non freezable water states claimed

  12. Monte Carlo Simulations of Thermal Conductivity in Nanoporous Si Membranes

    E-Print Network [OSTI]

    1 Monte Carlo Simulations of Thermal Conductivity in Nanoporous Si Membranes Stefanie Wolf1 transport in Si nanomeshes. Phonons are treated semiclassically as particles of specific energy and velocity, ii) the roughness amplitude of the pore surfaces on the thermal conductivity of the nanomeshes. We

  13. Transport Reactor Development Unit Modification to Provide a Syngas Slipstream at Elevated Conditions to Enable Separation of 100 LB/D of Hydrogen by Hydrogen Separation Membranes Year - 6 Activity 1.15 - Development of a National Center for Hydrogen Technology

    SciTech Connect (OSTI)

    Schlasner, Steven

    2012-03-01

    Gasification of coal when associated with carbon dioxide capture and sequestration has the potential to provide low-cost as well as low-carbon hydrogen for electric power, fuels or chemicals production. The key element to the success of this concept is inexpensive, effective separation of hydrogen from carbon dioxide in synthesis gas. Many studies indicate that membrane technology is one of the most, if not the most, economical means of accomplishing separation; however, the advancement of hydrogen separation membrane technology is hampered by the absence of experience or demonstration that the technology is effective economically and environmentally at larger scales. While encouraging performance has been observed at bench scale (less than 12 lb/d hydrogen), it would be imprudent to pursue a largescale demonstration without testing at least one intermediate scale, such as 100 lb/d hydrogen. Among its many gasifiers, the Energy & Environmental Research Center is home to the transport reactor demonstration unit (TRDU), a unit capable of firing 200—500 lb/hr of coal to produce 400 scfm of synthesis gas containing more than 200 lb/d of hydrogen. The TRDU and associated downstream processing equipment has demonstrated the capability of producing a syngas over a wide range of temperatures and contaminant levels — some of which approximate conditions of commercial-scale gasifiers. Until this activity, however, the maximum pressure of the TRDU’ s product syngas was 120 psig, well below the 400+ psig pressures of existing large gasifiers. This activity installed a high-temperature compressor capable of accepting the range of TRDU products up to 450°F and compressing them to 500 psig, a pressure comparable to some large scale gasifiers. Thus, with heating or cooling downstream of the TRDU compressor, the unit is now able to present a near-raw to clean gasifier synthesis gas containing more than 100 lb/d of hydrogen at up to 500 psig over a wide range of temperatures to hydrogen separation membranes or other equipment for development and demonstration.

  14. Durable Fuel Cell Membrane Electrode Assembly (MEA)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Durable Fuel Cell Membrane Electrode Assembly (MEA) Durable Fuel Cell Membrane Electrode Assembly (MEA) A revolutionary method of building a membrane electrode assembly (MEA) for...

  15. Battery utilizing ceramic membranes

    DOE Patents [OSTI]

    Yahnke, M.S.; Shlomo, G.; Anderson, M.A.

    1994-08-30

    A thin film battery is disclosed based on the use of ceramic membrane technology. The battery includes a pair of conductive collectors on which the materials for the anode and the cathode may be spin coated. The separator is formed of a porous metal oxide ceramic membrane impregnated with electrolyte so that electrical separation is maintained while ion mobility is also maintained. The entire battery can be made less than 10 microns thick while generating a potential in the 1 volt range. 2 figs.

  16. Supported microporous ceramic membranes

    DOE Patents [OSTI]

    Webster, Elizabeth (Madison, WI); Anderson, Marc (Madison, WI)

    1993-01-01

    A method for permformation of microporous ceramic membranes onto a porous support includes placing a colloidal suspension of metal or metal oxide particles on one side of the porous support and exposing the other side of the porous support to a drying stream of gas or a reactive gas stream so that the particles are deposited on the drying side of the support as a gel. The gel so deposited can be sintered to form a supported ceramic membrane useful for ultrafiltration, reverse osmosis, or molecular sieving having mean pore sizes less than 100 Angstroms.

  17. Supported microporous ceramic membranes

    DOE Patents [OSTI]

    Webster, E.; Anderson, M.

    1993-12-14

    A method for the formation of microporous ceramic membranes onto a porous support includes placing a colloidal suspension of metal or metal oxide particles on one side of the porous support and exposing the other side of the porous support to a drying stream of gas or a reactive gas stream so that the particles are deposited on the drying side of the support as a gel. The gel so deposited can be sintered to form a supported ceramic membrane useful for ultrafiltration, reverse osmosis, or molecular sieving having mean pore sizes less than 100 Angstroms. 4 figures.

  18. Membranes Improve Insulation Efficiency 

    E-Print Network [OSTI]

    Bullock, C. A.

    1986-01-01

    °F Temp. Under One White Membrane 74°F 74°F 73°F 88°F Temp. Inside Box 77°F 78°F 85" F 94" F test and the reason is speculated to be the same as test number 1. Legend: 1 Outside Air Temperature 2 One Clear 2 Mil. Membrane 3 One... suspended in their normal place. These data are plotted on Figure 8. In all cases, the function was a straight line and all points plotted on the line (A-E). Function (F) on Figure 8 is the calculated heat loss through the simulator walls and bottom...

  19. Poly(vinyl alcohol)-based buffering membranes for isoelectric trapping separations 

    E-Print Network [OSTI]

    Craver, Helen C.

    2009-05-15

    Isoelectric trapping (IET) in multicompartment electrolyzers (MCE) has been widely used for the electrophoretic separation of ampholytic compounds such as proteins. In IET, the separation occurs in the buffering membranes that form a step-wise p...

  20. Protein translocation without specific quality control in a computational model of the Tat system

    E-Print Network [OSTI]

    Chitra R. Nayak; Aidan I. Brown; Andrew D. Rutenberg

    2014-08-20

    The twin-arginine translocation (Tat) system transports folded proteins of various sizes across both bacterial and plant thylakoid membranes. The membrane-associated TatA protein is an essential component of the Tat translocon, and a broad distribution of different sized TatA-clusters is observed in bacterial membranes. We assume that the size dynamics of TatA clusters are affected by substrate binding, unbinding, and translocation to associated TatBC clusters, where clusters with bound translocation substrates favour growth and those without associated substrates favour shrinkage. With a stochastic model of substrate binding and cluster dynamics, we numerically determine the TatA cluster size distribution. We include a proportion of targeted but non-translocatable (NT) substrates, with the simplifying hypothesis that the substrate translocatability does not directly affect cluster dynamical rate constants or substrate binding or unbinding rates. This amounts to a translocation model without specific quality control. Nevertheless, NT substrates will remain associated with TatA clusters until unbound and so will affect cluster sizes and translocation rates. We find that the number of larger TatA clusters depends on the NT fraction $f$. The translocation rate can be optimized by tuning the rate of spontaneous substrate unbinding, $\\Gamma_U$. We present an analytically solvable three-state model of substrate translocation without cluster size dynamics that follows our computed translocation rates, and that is consistent with {\\em in vitro} Tat-translocation data in the presence of NT substrates.

  1. Membrane Mechanics of Endocytosis in Cells with Turgor

    E-Print Network [OSTI]

    Dmitrieff, Serge

    2015-01-01

    Endocytosis is an essential process by which cells internalize a piece of plasma membrane and material from the outside. In cells with turgor, pressure opposes membrane defor- mations, and increases the amount of force that has to be generated by the endocytic machinery. To determine this force, and calculate the shape of the membrane, we used physical theory to model an elastic surface under pressure. Accurate fits of experimental profiles are obtained assuming that the coated membrane is highly rigid and preferentially curved at the endocytic site. The forces required from the actin machinery peaks at the onset of deformation, indicating that once invagination has been initiated, endocytosis is unlikely to stall before completion. Coat proteins do not lower the initiation force but may affect the process by the curvature they induce. In the presence of isotropic curvature inducers, pulling the tip of the invagination can trigger the formation of a neck at the base of the invagination. Hence direct neck cons...

  2. Ternary structure reveals mechanism of a membrane diacylglycerol kinase

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Li, Dianfan; Stansfeld, Phillip J.; Sansom, Mark S. P.; Keogh, Aaron; Vogeley, Lutz; Howe, Nicole; Lyons, Joseph A.; Aragao, David; Fromme, Petra; Fromme, Raimund; et al

    2015-12-17

    Diacylglycerol kinase catalyses the ATP-dependent conversion of diacylglycerol to phosphatidic acid in the plasma membrane of Escherichia coli. The small size of this integral membrane trimer, which has 121 residues per subunit, means that available protein must be used economically to craft three catalytic and substrate-binding sites centred about the membrane/cytosol interface. How nature has accomplished this extraordinary feat is revealed here in a crystal structure of the kinase captured as a ternary complex with bound lipid substrate and an ATP analogue. Residues, identified as essential for activity by mutagenesis, decorate the active site and are rationalized by the ternarymore »structure. The ?-phosphate of the ATP analogue is positioned for direct transfer to the primary hydroxyl of the lipid whose acyl chain is in the membrane. A catalytic mechanism for this unique enzyme is proposed. As a result, the active site architecture shows clear evidence of having arisen by convergent evolution.« less

  3. Ceramic membranes having macroscopic channels

    DOE Patents [OSTI]

    Anderson, Marc A. (Madison, WI); Peterson, Reid A. (Madison, WI)

    1996-01-01

    Methods have been developed to make porous ceramic membranes having macroscopic channels therethrough. The novel membranes are formed by temporarily supporting the sol-gel membrane precursor on an organic support which is ultimately removed from the interior of the membrane, preferably by pyrolysis or by chemical destruction. The organic support may also include an inorganic metal portion that remains on destruction of the organic portion, providing structural support and/or chemical reactivity to the membrane. The channels formed when the organic support is destroyed provide the ability to withdraw small catalytic products or size-separated molecules from the metal oxide membrane. In addition, the channel-containing membranes retain all of the advantages of existing porous ceramic membranes.

  4. Hydrogen-selective membrane

    DOE Patents [OSTI]

    Collins, J.P.; Way, J.D.

    1997-07-29

    A hydrogen-selective membrane comprises a tubular porous ceramic support having a palladium metal layer deposited on an inside surface of the ceramic support. The thickness of the palladium layer is greater than about 10 {micro}m but typically less than about 20 {micro}m. The hydrogen permeation rate of the membrane is greater than about 1.0 moles/m{sup 2} s at a temperature of greater than about 500 C and a transmembrane pressure difference of about 1,500 kPa. Moreover, the hydrogen-to-nitrogen selectivity is greater than about 600 at a temperature of greater than about 500 C and a transmembrane pressure of about 700 kPa. Hydrogen can be separated from a mixture of gases using the membrane. The method may include the step of heating the mixture of gases to a temperature of greater than about 400 C and less than about 1000 C before the step of flowing the mixture of gases past the membrane. The mixture of gases may include ammonia. The ammonia typically is decomposed to provide nitrogen and hydrogen using a catalyst such as nickel. The catalyst may be placed inside the tubular ceramic support. The mixture of gases may be supplied by an industrial process such as the mixture of exhaust gases from the IGCC process. 9 figs.

  5. Hydrogen-selective membrane

    DOE Patents [OSTI]

    Collins, John P. (Boulder, CO); Way, J. Douglas (Boulder, CO)

    1997-01-01

    A hydrogen-selective membrane comprises a tubular porous ceramic support having a palladium metal layer deposited on an inside surface of the ceramic support. The thickness of the palladium layer is greater than about 10 .mu.m but typically less than about 20 .mu.m. The hydrogen permeation rate of the membrane is greater than about 1.0 moles/m.sup.2. s at a temperature of greater than about 500.degree. C. and a transmembrane pressure difference of about 1,500 kPa. Moreover, the hydrogen-to-nitrogen selectivity is greater than about 600 at a temperature of greater than about 500.degree. C. and a transmembrane pressure of about 700 kPa. Hydrogen can be separated from a mixture of gases using the membrane. The method may include the step of heating the mixture of gases to a temperature of greater than about 400.degree. C. and less than about 1000.degree. C. before the step of flowing the mixture of gases past the membrane. The mixture of gases may include ammonia. The ammonia typically is decomposed to provide nitrogen and hydrogen using a catalyst such as nickel. The catalyst may be placed inside the tubular ceramic support. The mixture of gases may be supplied by an industrial process such as the mixture of exhaust gases from the IGCC process.

  6. Hydrogen-Selective Membrane

    DOE Patents [OSTI]

    Collins, John P. (Boulder, CO); Way, J. Douglas (Boulder, CO)

    1995-09-19

    A hydrogen-selective membrane comprises a tubular porous ceramic support having a palladium metal layer deposited on an inside surface of the ceramic support. The thickness of the palladium layer is greater than about 10 .mu.m but typically less than about 20 .mu.m. The hydrogen permeation rate of the membrane is greater than about 1.0 moles/m.sup.2.s at a temperature of greater than about 500.degree. C. and a transmembrane pressure difference of about 1,500 kPa. Moreover, the hydrogen-to-nitrogen selectivity is greater than about 600 at a temperature of greater than about 500.degree. C. and a transmembrane pressure of about 700 kPa. Hydrogen can be separated from a mixture of gases using the membrane. The method may include the step of heating the mixture of gases to a temperature of greater than about 400.degree. C. and less than about 1000.degree. C. before the step of flowing the mixture of gases past the membrane. The mixture of gases may include ammonia. The ammonia typically is decomposed to provide nitrogen and hydrogen using a catalyst such as nickel. The catalyst may be placed inside the tubular ceramic support. The mixture of gases may be supplied by an industrial process such as the mixture of exhaust gases from the IGCC process.

  7. Hydrogen-selective membrane

    DOE Patents [OSTI]

    Collins, J.P.; Way, J.D.

    1995-09-19

    A hydrogen-selective membrane comprises a tubular porous ceramic support having a palladium metal layer deposited on an inside surface of the ceramic support. The thickness of the palladium layer is greater than about 10 {micro}m but typically less than about 20 {micro}m. The hydrogen permeation rate of the membrane is greater than about 1.0 moles/m{sup 2}s at a temperature of greater than about 500 C and a transmembrane pressure difference of about 1,500 kPa. Moreover, the hydrogen-to-nitrogen selectivity is greater than about 600 at a temperature of greater than about 500 C and a transmembrane pressure of about 700 kPa. Hydrogen can be separated from a mixture of gases using the membrane. The method may include the step of heating the mixture of gases to a temperature of greater than about 400 C and less than about 1000 C before the step of flowing the mixture of gases past the membrane. The mixture of gases may include ammonia. The ammonia typically is decomposed to provide nitrogen and hydrogen using a catalyst such as nickel. The catalyst may be placed inside the tubular ceramic support. The mixture of gases may be supplied by an industrial process such as the mixture of exhaust gases from the IGCC process. 9 figs.

  8. Investigating transport through sub-nanometer zeolites pores

    E-Print Network [OSTI]

    Humplik, Thomas

    2014-01-01

    Membrane-based reverse osmosis (RO), which accounts for over 40% of the current worldwide desalination capacity, is limited by the solution-diffusion mode of water transport through a tortuous polymeric active layer. ...

  9. Facilitated Transport of Small Carbohydrates through Plasticized Cellulose Triacetate

    E-Print Network [OSTI]

    Smith, Bradley D.

    Facilitated Transport of Small Carbohydrates through Plasticized Cellulose Triacetate Membranes.7,8 This report describes plasticized cellulose triacetate mem- branes that incorporate a large involved plasticized films that are homogeneous mixtures of cellulose triacetate (CTA), plasticizer (e

  10. Automotive Perspective on Membrane Evaluation

    Broader source: Energy.gov [DOE]

    Presentation at the 2008 High Temperature Membrane Working Group Meeting held June 9, 2008, in Washington, DC

  11. THE JOURNAL OF CHEMICAL PHYSICS 134, 044908 (2011) Multicomponent ballistic transport in narrow single wall carbon

    E-Print Network [OSTI]

    Adler, Joan

    2011-01-01

    online 27 January 2011) The transport of gas mixtures through molecular-sieve membranes such as narrow The transport of gas mixtures through molecular-sieve membranes and catalysts has been a subject of intensive in single wall carbon nanotubes: Analytic model and molecular dynamics simulations T. Mutat,1 J. Adler,1,a

  12. Recycling of used perfluorosulfonic acid membranes

    DOE Patents [OSTI]

    Grot, Stephen (Middletown, DE); Grot, Walther (Chadds Ford, PA)

    2007-08-14

    A method for recovering and recycling catalyst coated fuel cell membranes includes dissolving the used membranes in water and solvent, heating the dissolved membranes under pressure and separating the components. Active membranes are produced from the recycled materials.

  13. Hydrogen production by water dissociation using ceramic membranes - annual report for FY 2010.

    SciTech Connect (OSTI)

    Balachandran, U.; Dorris, S. E.; Emerson, J. E.; Lee, T. H.; Lu, Y.; Park, C. Y.; Picciolo, J. J. (Energy Systems)

    2011-03-14

    The objective of this project is to develop dense ceramic membranes that can produce hydrogen via coal/coal gas-assisted water dissociation without using an external power supply or circuitry. This project grew from an effort to develop a dense ceramic membrane for separating hydrogen from gas mixtures such as those generated during coal gasification, methane partial oxidation, and water-gas shift reactions. That effort led to the development of various cermet (i.e., ceramic/metal composite) membranes that enable hydrogen production by two methods. In one method, a hydrogen transport membrane (HTM) selectively removes hydrogen from a gas mixture by transporting it through either a mixed protonic/electronic conductor or a hydrogen transport metal. In the other method, an oxygen transport membrane (OTM) generates hydrogen mixed with steam by removing oxygen that is generated through water splitting. This project focuses on the development of OTMs that efficiently produce hydrogen via the dissociation of water. Supercritical boilers offer very high-pressure steam that can be decomposed to provide pure hydrogen using OTMs. Oxygen resulting from the dissociation of steam can be used for coal gasification, enriched combustion, or synthesis gas production. Hydrogen and sequestration-ready CO{sub 2} can be produced from coal and steam by using the membrane being developed in this project. Although hydrogen can also be generated by high-temperature steam electrolysis, producing hydrogen by water splitting with a mixed-conducting membrane requires no electric power or electrical circuitry.

  14. Robust Polymer Composite Membranes for Hydrogen Separation |...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Robust Polymer Composite Membranes for Hydrogen Separation Robust Polymer Composite Membranes for Hydrogen Separation polymercompositemembranes.pdf More Documents & Publications...

  15. Non-Tracial Free Transport and Applications

    E-Print Network [OSTI]

    Nelson, Brent Andrew

    2015-01-01

    tracial transport . . . . . . . . . . . . . . . . . . . .the transport element . . . . . . . . . . . . . .Free Transport . . . . . . . . . . . .

  16. Pilot Scale Water Gas Shift - Membrane Device for Hydrogen from Coal

    SciTech Connect (OSTI)

    Barton, Tom

    2013-06-30

    The objectives of the project were to build pilot scale hydrogen separation systems for use in a gasification product stream. This device would demonstrate fabrication and manufacturing techniques for producing commercially ready facilities. The design was a 2 lb/day hydrogen device which included composite hydrogen separation membranes, a water gas shift monolith catalyst, and stainless steel structural components. Synkera Technologies was to prepare hydrogen separation membranes with metallic rims, and to adjust the alloy composition in their membranes to a palladium-gold composition which is sulfur resistant. Chart was to confirm their brazing technology for bonding the metallic rims of the composite membranes to their structural components and design and build the 2 lbs/day device incorporating membranes and catalysts. WRI prepared the catalysts and completed the testing of the membranes and devices on coal derived syngas. The reactor incorporated eighteen 2'' by 7'' composite palladium alloy membranes. These membranes were assembled with three stacks of three paired membranes. Initial vacuum testing and visual inspection indicated that some membranes were cracked, either in transportation or in testing. During replacement of the failed membranes, while pulling a vacuum on the back side of the membranes, folds were formed in the flexible composite membranes. In some instances these folds led to cracks, primarily at the interface between the alumina and the aluminum rim. The design of the 2 lb/day device was compromised by the lack of any membrane isolation. A leak in any membrane failed the entire device. A large number of tests were undertaken to bring the full 2 lb per day hydrogen capacity on line, but no single test lasted more than 48 hours. Subsequent tests to replace the mechanical seals with brazing have been promising, but the technology remains promising but not proven.

  17. Unique battery with an active membrane separator having uniform physico-chemically functionalized ion channels and a method making the same

    DOE Patents [OSTI]

    Gerald, II, Rex E. (Brookfield, IL); Ruscic, Katarina J. (Chicago, IL); Sears, Devin N. (Spruce Grove, CA); Smith, Luis J. (Natick, MA); Klingler, Robert J. (Glenview, IL); Rathke, Jerome W. (Homer Glen, IL)

    2012-02-21

    The invention relates to a unique battery having an active, porous membrane and method of making the same. More specifically the invention relates to a sealed battery system having a porous, metal oxide membrane with uniform, physicochemically functionalized ion channels capable of adjustable ionic interaction. The physicochemically-active porous membrane purports dual functions: an electronic insulator (separator) and a unidirectional ion-transporter (electrolyte). The electrochemical cell membrane is activated for the transport of ions by contiguous ion coordination sites on the interior two-dimensional surfaces of the trans-membrane unidirectional pores. The membrane material is designed to have physicochemical interaction with ions. Control of the extent of the interactions between the ions and the interior pore walls of the membrane and other materials, chemicals, or structures contained within the pores provides adjustability of the ionic conductivity of the membrane.

  18. Final Report - Membranes and MEA's for Dry, Hot Operating Conditions

    SciTech Connect (OSTI)

    Hamrock, Steven J.

    2011-06-30

    The focus of this program was to develop a new Proton Exchange Membrane (PEM) which can operate under hotter, dryer conditions than the state of the art membranes today and integrate it into a Membrane Electrode Assembly (MEA). These MEA's should meet the performance and durability requirements outlined in the solicitation, operating under low humidification conditions and at temperatures ranging from -20���ºC to 120���ºC, to meet 2010 DOE technical targets for membranes. This membrane should operate under low humidification conditions and at temperatures ranging from -20���ºC to 120���ºC in order to meet DOE HFCIT 2010 commercialization targets for automotive fuel cells. Membranes developed in this program may also have improved durability and performance characteristics making them useful in stationary fuel cell applications. The new membranes, and the MEA�¢����s comprising them, should be manufacturable at high volumes and at costs which can meet industry and DOE targets. This work included: A) Studies to better understand factors controlling proton transport within the electrolyte membrane, mechanisms of polymer degradation (in situ and ex situ) and membrane durability in an MEA; B) Development of new polymers with increased proton conductivity over the range of temperatures from -20���ºC to 120���ºC and at lower levels of humidification and with improved chemical and mechanical stability; C) Development of new membrane additives for increased durability and conductivity under these dry conditions; D) Integration of these new materials into membranes and membranes into MEA�¢����s, including catalyst and gas diffusion layer selection and integration; E) Verification that these materials can be made using processes which are scalable to commercial volumes using cost effective methods; F) MEA testing in single cells using realistic automotive testing protocols. This project addresses technical barriers A (Durability) and C (Performance) from the Fuel Cells section of the 2005 Hydrogen, Fuel Cells and Infrastructure Technologies Program Multi-Year R&D Plan. In the course of this four-year program we developed a new PEM with improved proton conductivity, chemical stability and mechanical stability. We incorporated this new membrane into MEAs and evaluated performance and durability.

  19. Center for Nanostructured Biomimetic Interfaces Integrated Electrochemical and Optical Methods for Studying TRPV Channel Proteins

    E-Print Network [OSTI]

    for Studying TRPV Channel Proteins Sachin Vaidya, Neeraj kohli, Brian Hassler, Lavanya Parthasarathy Robert is a transmembrane protein; sufficient space is needed on either side of bilayer to allow the reconstituted protein) and membrane-bound protein(s) to efficiently perform a diverse array of vital molecular processes ·These

  20. Cotranslational integration and initial sorting at the endoplasmic reticulum translocon of proteins

    E-Print Network [OSTI]

    Summers, Max D.

    Cotranslational integration and initial sorting at the endoplasmic reticulum translocon of proteins for protein trafficking to the inner nuclear membrane (INM) proposes that INM proteins diffuse laterally from proteins or DNA. Because some data indicate that the sorting of baculovirus envelope proteins to the INM

  1. Membrane separation of hydrocarbons

    DOE Patents [OSTI]

    Chang, Y. Alice (Des Plaines, IL); Kulkarni, Sudhir S. (Hoffman Estates, IL); Funk, Edward W. (Highland Park, IL)

    1986-01-01

    Mixtures of heavy oils and light hydrocarbons may be separated by passing the mixture through a polymeric membrane. The membrane which is utilized to effect the separation comprises a polymer which is capable of maintaining its integrity in the presence of hydrocarbon compounds and which has been modified by being subjected to the action of a sulfonating agent. Sulfonating agents which may be employed will include fuming sulfuric acid, chlorosulfonic acid, sulfur trioxide, etc., the surface or bulk modified polymer will contain a degree of sulfonation ranging from about 15 to about 50%. The separation process is effected at temperatures ranging from about ambient to about 100.degree. C. and pressures ranging from about 50 to about 1000 psig.

  2. Membranes on an Orbifold

    E-Print Network [OSTI]

    Neil Lambert; David Tong

    2008-04-15

    We harvest clues to aid with the interpretation of the recently discovered N=8 supersymmetric Chern-Simons theory with SO(4) gauge symmetry. The theory is argued to describe two membranes moving in the orbifold R8/Z2. At level k=1 and k=2, the classical moduli space M coincides with the infra-red moduli space of SO(4) and SO(5) super Yang-Mills theory respectively. For higher Chern-Simons level, the moduli space is a quotient of M. At a generic point in the moduli space, the massive spectrum is proportional to the area of the triangle formed by the two membranes and the orbifold fixed point.

  3. Elastohydrodynamics and kinetics of protein patterning in the immunological synapse

    E-Print Network [OSTI]

    Carlson, Andreas

    2015-01-01

    The cellular basis for the adaptive immune response during antigen recognition relies on a specialized protein interface known as the immunological synapse (IS). Understanding the biophysical basis for protein patterning by deciphering the quantitative rules for their formation and motion is an important aspect of characterizing immune cell recognition and thence the rules for immune system activation. We propose a minimal mathematical model for the physical basis of membrane protein patterning in the IS, which encompass membrane mechanics, protein binding kinetics and motion, and fluid flow in the synaptic cleft. Our theory leads to simple predictions for the spatial and temporal scales of protein cluster formation, growth and arrest as a function of membrane stiffness, rigidity and kinetics of the adhesive proteins, and the fluid in the synaptic cleft. Numerical simulations complement these scaling laws by quantifying the nucleation, growth and stabilization of proteins domains on the size of the cell. Dire...

  4. Synthesis of an un-supported, high-flow ZSM-22 zeolite membrane

    DOE Patents [OSTI]

    Thoma, Steven G. (Albuquerque, NM); Nenoff, Tina M. (Albuquerque, NM)

    2006-10-10

    Novel methods for synthesizing wholly un-supported, high-flow catalytic membranes consisting of 100% crystalline ZSM-22 crystals with no binder phase, having sufficient porosity to allow high Weight Hourly Space Velocities of feedstock to pass through without generating back pressure. The ZSM-22 membranes perform favorably to existing bulk ZSM-22 catalysts (e.g., via 1-butene conversion and selectivity). The method of membrane synthesis, based on Vapor Phase Transport, allows free-standing, binder-less membranes to be fabricated in varied geometries and sizes so that membranes can be tailor-made for particular geometries applications. The ZSM-22 precursor gel may be consolidated into a semi-cohesive body prior to vapor phase crystallization, for example, by uniaxial pressing. These crystalline membranes may be modified by ion exchange, pore ion exchange, framework exchange, synthesis modification techniques to incorporate other elements into the framework, such as K, H, Mg, Zn, V, Ga, and Pt.

  5. Hierarchical organization of chiral rafts in colloidal membranes

    E-Print Network [OSTI]

    Prerna Sharma; Andrew Ward; T. Gibaud; Michael F. Hagan; Zvonimir Dogic

    2014-09-09

    Liquid-liquid phase separation is ubiquitous in suspensions of nanoparticles, proteins and colloids. With a few notable exceptions, surface-tension-minimizing liquid droplets in bulk suspensions continuously coalesce, increasing in size without bound until achieving macroscale phase separation. In comparison, the phase behavior of colloids, nanoparticles or proteins confined to interfaces, surfaces or membranes is significantly more complex. Inclusions distort the local interface structure leading to interactions that are fundamentally different from the well-studied interactions mediated by isotropic solvents. Here, we investigate liquid-liquid phase separation in monolayer membranes composed of dissimilar chiral colloidal rods. We demonstrate that colloidal rafts are a ubiquitous feature of binary colloidal membranes. We measure the raft free energy landscape by visualizing its assembly kinetics. Subsequently, we quantify repulsive raft-raft interactions and relate them to directly imaged raft-induced membrane distortions, demonstrating that particle chirality plays a key role in this microphase separation. At high densities, rafts assemble into cluster crystals which constantly exchange monomeric rods with the background reservoir to maintain a self-limited size. Lastly, we demonstrate that rafts can form bonds to assemble into higher-order supra-structures. Our work demonstrates that membrane-mediated liquid-liquid phase separation can be fundamentally different from the well-characterized behavior of bulk liquids. It outlines a robust membrane-based pathway for assembly of monodisperse liquid clusters which is complementary to existing methods which take place in bulk suspensions. Finally, it reveals that chiral inclusions in membranes acquire long-ranged repulsive interactions, which might play a role in stabilizing assemblages of finite size.

  6. A Robust and Rapid Method of Producing Soluble, Stable, and Functional G-Protein Coupled Receptors

    E-Print Network [OSTI]

    Baaske, Philipp

    Membrane proteins, particularly G-protein coupled receptors (GPCRs), are notoriously difficult to express. Using commercial E.coli cell-free systems with the detergent Brij-35, we could rapidly produce milligram quantities ...

  7. Oxygen-permeable ceramic membranes for gas separation

    SciTech Connect (OSTI)

    Balachandran, U.; Ma, B.; Maiya, P.S.; Dusek, J.T.; Mieville, R.L.; Picciolo, J.J.

    1998-02-01

    Mixed-conducting oxides have a wide range of applications, including fuel cells, gas separation systems, sensors, and electrocatalytic equipment. Dense ceramic membranes made of mixed-conducting oxides are particularly attractive for gas separation and methane conversion processes. Membranes made of Sr-Fe-Co oxide, which exhibits high combined electronic and oxygen ionic conductivities, can be used to selectively transport oxygen during the partial oxidation of methane to synthesis gas (syngas, i.e., CO + H{sub 2}). The authors have fabricated tubular Sr{sub 2}Fe{sub 2}CoO{sub 6+{delta}} membranes and tested them (some for more than 1,000 h) in a methane conversion reactor that was operating at 850--950 C. An oxygen permeation flux of {approx} 10 scc/cm{sup 2} {center_dot} min was obtained at 900 C in a tubular membrane with a wall thickness of 0.75 mm. Using a gas-tight electrochemical cell, the authors have also measured the steady-state oxygen permeability of flat Sr{sub 2}Fe{sub 2}CoO{sub 6+{delta}} membranes as a function of temperature and oxygen partial pressure(pO{sub 2}). Steady-state oxygen permeability increases with increasing temperature and with the difference in pO{sub 2} on the two sides of the membrane. At 900 C, an oxygen permeability of {approx} 2.5 scc/cm{sup 2} {center_dot} min was obtained in a 2.9-mm-thick membrane. This value agrees with that obtained in methane conversion reactor experiments. Current-voltage (I-V) characteristics determined in the gas-tight cell indicate that bulk effect, rather than surface exchange effect, is the main limiting factor for oxygen permeation of {approx} 1-mm-thick Sr{sub 2}Fe{sub 2}CoO{sub 6+{delta}} membranes at elevated temperatures (> 650 C).

  8. Among the major applications of pervaporation membrane processes, organic separation from organic/water mixtures is becoming increasingly important. The

    E-Print Network [OSTI]

    Among the major applications of pervaporation membrane processes, organic separation from organic referred to as "silicone rubber", exhibiting excellent film-forming ability, thermal stability, chemical for Engineering of Matter, Transport and Energy #12;

  9. Implications of Permeation through Intrinsic Defects in Graphene on the Design of Defect-Tolerant Membranes for Gas Separation

    E-Print Network [OSTI]

    Sun, Chengzhen

    Gas transport through intrinsic defects and tears is a critical yet poorly understood phenomenon in graphene membranes for gas separation. We report that independent stacking of graphene layers on a porous support exponentially ...

  10. a p p l i c a t i o n n o t e Purification/Polishing of His-tagged proteins -Application of Centrifugal

    E-Print Network [OSTI]

    Lebendiker, Mario

    of Centrifugal Vivapure Ion-exchange Membrane Devices to the Purification/Polishing of His- tagged Proteins of Centrifugal Vivapure Ion-exchange Membrane Devices to the Purification/Polishing of His-tagged Proteins of centrifugal Vivapure ion exchange membrane devices for rapid comparison of anion (Q), and cation (S) ion

  11. Insights into a Single Rod-like Helix in Activated Radixin Required for Membrane-Cytoskeletal Cross-Linking

    E-Print Network [OSTI]

    Ikura, Mitsuhiko

    : The members of the ezrin-radixin-moesin (ERM) family of proteins function as membrane- cytoskeletal cross-linkers in actin-rich cell surface structures. ERM proteins are thereby thought to be essential for cortical regulation of ERM protein function occurs by association of the FERM and C-terminal domains, whereby

  12. Supported liquid membrane electrochemical separators

    DOE Patents [OSTI]

    Pemsler, J. Paul (Lexington, MA); Dempsey, Michael D. (Revere, MA)

    1986-01-01

    Supported liquid membrane separators improve the flexibility, efficiency and service life of electrochemical cells for a variety of applications. In the field of electrochemical storage, an alkaline secondary battery with improved service life is described in which a supported liquid membrane is interposed between the positive and negative electrodes. The supported liquid membranes of this invention can be used in energy production and storage systems, electrosynthesis systems, and in systems for the electrowinning and electrorefining of metals.

  13. Alkaline Membrane Electrolysis

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Delicious Rank EERE:FinancingPetroleum Based Fuels Research at NRELDepartmentJune 2, 2015AlignedRPTnnnn Membrane-Based

  14. Microalgae Cultivation using Offshore Membrane Enclosures for Growing Algae (OMEGA)

    E-Print Network [OSTI]

    Wiley, Patrick Edward

    2013-01-01

    Microalgae cultivation using offshore membrane enclosuresbiofouling on the proposed offshore membrane enclosures forMicroalgae cultivation using offshore membrane enclosures

  15. Plastidic Pi transporters in Arabidopsis thaliana 

    E-Print Network [OSTI]

    Irigoyen Aranda, Sonia Cristina

    2012-10-19

    and reverse genetics to demonstrate functional specialization for the PHT4 family members with a focus on PHT4;1 and PHT4;2. The PHT4;1 Pi transporter is localized to chloroplast thylakoid membranes and it is expressed in a circadian manner. Plants that lack a...

  16. Hydrogen separation membranes annual report for FY 2010.

    SciTech Connect (OSTI)

    Balachandran, U.; Dorris, S. E; Emerson, J. E.; Lee, T. H.; Lu, Y.; Park, C. Y.; Picciolo, J. J.

    2011-03-14

    The objective of this work is to develop dense ceramic membranes for separating hydrogen from other gaseous components in a nongalvanic mode, i.e., without using an external power supply or electrical circuitry. The goal of this project is to develop dense hydrogen transport membranes (HTMs) that nongalvanically (i.e., without electrodes or external power supply) separate hydrogen from gas mixtures at commercially significant fluxes under industrially relevant operating conditions. These membranes will be used to separate hydrogen from gas mixtures such as the product streams from coal gasification, methane partial oxidation, and water-gas shift reactions. Potential ancillary uses of HTMs include dehydrogenation and olefin production, as well as hydrogen recovery in petroleum refineries and ammonia synthesis plants, the largest current users of deliberately produced hydrogen. This report describes the results from the development and testing of HTM materials during FY 2010.

  17. Palladium-coated zirconium membranes for oxidative extraction of hydrogen

    SciTech Connect (OSTI)

    Hsu, C.; Buxbaum, R.E.

    1987-01-01

    Palladium-coated metal membranes are attractive choices for low pressure, high temperature hydrogen and hydrogen isotope extractions, e.g. from fusion blanket fluids. The authors present experimental data on hydrogen transport through palladium-coated zirconium membranes at 600 - 700/sup 0/K. The upstream hydrogen pressure range is 10/sup -4/ to 10/sup -6/ torr and an oxygen-containing gas flows over the downstream side of the membrane. Thus, the irreversible oxidation reaction drives the flux. Deuterium permeabilities in zirconium are 2.00x10/sup -6/exp(59/T)+-20% g-mol/m.s.Pa/sup 1/2/, similar to the values obtained from diffusivity and solubility measurements. Extrapolated deuterium absorptive sticking coefficients on palladium are about .05.

  18. Water Transport in Hydrophilic Channels of Nafion (DMR 0819860)

    E-Print Network [OSTI]

    Petta, Jason

    (RH) that open up the ion channels for optimal proton transport. Nafion, a polymer used for fuel cells Benziger, Princeton University Sr Fuel cells convert chemical energy to electrical energy by transporting protons through ion conducting channels in polymer membranes. Improving proton conduction will make fuel

  19. Sustainable Transportation

    SciTech Connect (OSTI)

    2012-09-01

    This document highlights DOE's Office of Energy Efficiency and Renewable Energy's advancements in transportation technologies, alternative fuels, and fuel cell technologies.

  20. Crystallographic Structure of SurA, a Molecular Chaperone that Facilitates Folding of Outer Membrane Porins

    SciTech Connect (OSTI)

    Bitto, E.

    2002-01-01

    The SurA protein facilitates correct folding of outer membrane proteins in gram-negative bacteria. The sequence of Escherichia coli SurA presents four segments, two of which are peptidyl-prolyl isomerases (PPIases); the crystal structure reveals an asymmetric dumbbell, in which the amino-terminal, carboxy-terminal, and first PPIase segments of the sequence form a core structural module, and the second PPIase segment is a satellite domain tethered approximately 30 A from this module. The core module, which is implicated in membrane protein folding, has a novel fold that includes an extended crevice. Crystal contacts show that peptides bind within the crevice, suggesting a model for chaperone activity whereby segments of polypeptide may be repetitively sequestered and released during the membrane protein-folding process.

  1. Amorphous Alloy Membranes for High Temperature Hydrogen Separation

    SciTech Connect (OSTI)

    Coulter, K

    2013-09-30

    At the beginning of this project, thin film amorphous alloy membranes were considered a nascent but promising new technology for industrial-scale hydrogen gas separations from coal- derived syngas. This project used a combination of theoretical modeling, advanced physical vapor deposition fabricating, and laboratory and gasifier testing to develop amorphous alloy membranes that had the potential to meet Department of Energy (DOE) targets in the testing strategies outlined in the NETL Membrane Test Protocol. The project is complete with Southwest Research Institute® (SwRI®), Georgia Institute of Technology (GT), and Western Research Institute (WRI) having all operated independently and concurrently. GT studied the hydrogen transport properties of several amorphous alloys and found that ZrCu and ZrCuTi were the most promising candidates. GT also evaluated the hydrogen transport properties of V, Nb and Ta membranes coated with different transition-metal carbides (TMCs) (TM = Ti, Hf, Zr) catalytic layers by employing first-principles calculations together with statistical mechanics methods and determined that TiC was the most promising material to provide catalytic hydrogen dissociation. SwRI developed magnetron coating techniques to deposit a range of amorphous alloys onto both porous discs and tubular substrates. Unfortunately none of the amorphous alloys could be deposited without pinhole defects that undermined the selectivity of the membranes. WRI tested the thermal properties of the ZrCu and ZrNi alloys and found that under reducing environments the upper temperature limit of operation without recrystallization is ~250 °C. There were four publications generated from this project with two additional manuscripts in progress and six presentations were made at national and international technical conferences. The combination of the pinhole defects and the lack of high temperature stability make the theoretically identified most promising candidate amorphous alloys unsuitable for application as hydrogen separation membranes in coal fire systems.

  2. Performance modelling of a proton exchange membrane fuel cell

    SciTech Connect (OSTI)

    Marr, C.; Li, X.

    1998-12-31

    This paper presents a performance model of a proton exchange membrane fuel cell that has sufficient accuracy for engineering applications with reduced computational requirements. The model includes electrochemical reaction in the catalyst layers and formulation for electrical resistance in the membrane, electrodes and bipolar plates, and employs engineering correlation for the reactant gas transport in the flow channels and through the electrodes. It is shown that the present model predictions are in reasonable agreement with known experimental observations, indicating that the present model can be employed for fuel cell stack and system modeling. The effect of various operating and design parameters on the cell performance has been investigated. It is found that mass transport limitations are the largest cause of performance loss in the cell when graphite is used as the material for bipolar plates and electrodes. If conducting polymers are substituted as construction materials, cell performance is expected to suffer considerably at high current densities due to their reduced electrical conductivity.

  3. Environment-Assisted Quantum Transport

    E-Print Network [OSTI]

    Patrick Rebentrost; Masoud Mohseni; Ivan Kassal; Seth Lloyd; Alán Aspuru-Guzik

    2009-02-10

    Transport phenomena at the nanoscale are of interest due to the presence of both quantum and classical behavior. In this work, we demonstrate that quantum transport efficiency can be enhanced by a dynamical interplay of the system Hamiltonian with pure dephasing induced by a fluctuating environment. This is in contrast to fully coherent hopping that leads to localization in disordered systems, and to highly incoherent transfer that is eventually suppressed by the quantum Zeno effect. We study these phenomena in the Fenna-Matthews-Olson protein complex as a prototype for larger photosynthetic energy transfer systems. We also show that disordered binary tree structures exhibit enhanced transport in the presence of dephasing.

  4. Structural Rearrangement in Ebola Virus Protein VP40 Creates...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Virus Protein VP40 Creates Multiple Functions Monday, March 31, 2014 Figure 1. Three structures of VP40. Top, a butterfly-shaped dimer structure critical for membrane trafficking....

  5. High Flux Metallic Membranes for Hydrogen Recovery and Membrane Reactors

    SciTech Connect (OSTI)

    Buxbaum, Robert

    2010-06-30

    We made and tested over 250 new alloys for use as lower cost, higher flux hydrogen extraction membrane materials. Most of these were intermetallic, or contained significant intermetallic content, particularly based on B2 alloy compositions with at least one refractory component; B2 intermetallics resemble BCC alloys, in structure, but the atoms have relatively fixed positions, with one atom at the corners of the cube, the other at the centers. The target materals we were looking for would contain little or no expensive elements, no strongly toxic or radioactive elements, would have high flux to hydrogen, while being fabricable, brazable, and relatively immune to hydrogen embrittlement and corrosion in operation. The best combination of properties of the membrane materials we developed was, in my opinion, a Pd-coated membrane consisting of V -9 atomic % Pd. This material was relatively cheap, had 5 times the flux of Pd under the same pressure differential, was reasonably easy to fabricate and braze, and not bad in terms of embrittlement. Based on all these factors we project, about 1/3 the cost of Pd, on an area basis for a membrane designed to last 20 years, or 1/15 the cost on a flux basis. Alternatives to this membrane replaced significant fractions of the Pd with Ni and or Co. The cost for these membranes was lower, but so was the flux. We produced successful brazed products from the membrane materials, and made them into flat sheets. We tested, unsuccessfully, several means of fabricating thematerials into tubes, and eventually built a membrane reactor using a new, flat-plate design: a disc and doughnut arrangement, a design that seems well- suited to clean hydrogen production from coal. The membranes and reactor were tested successfully at Western Research. A larger equipment company (Chart Industries) produced similar results using a different flat-plate reactor design. Cost projections of the membrane are shown to be attractive.

  6. Olefin separation membrane and process

    DOE Patents [OSTI]

    Pinnau, Ingo (Palo Alto, CA); Toy, Lora G. (San Francisco, CA); Casillas, Carlos (San Jose, CA)

    1997-01-01

    A membrane and process for separating unsaturated hydrocarbons from fluid mixtures. The membrane and process differ from previously known membranes and processes, in that the feed and permeate streams can both be dry, the membrane need not be water or solvent swollen, and the membrane is characterized by a selectivity for an unsaturated hydrocarbon over a saturated hydrocarbon having the same number of carbon atoms of at least about 20, and a pressure-normalized flux of said unsaturated hydrocarbon of at least about 5.times.10.sup.-6 cm.sup.3 (STP)/cm.sup.2 .multidot.s.multidot.cmHg, said flux and selectivity being measured with a gas mixture containing said unsaturated and saturated hydrocarbons, and in a substantially dry environment.

  7. Olefin separation membrane and process

    DOE Patents [OSTI]

    Pinnau, I.; Toy, L.G.; Casillas, C.

    1997-09-23

    A membrane and process are disclosed for separating unsaturated hydrocarbons from fluid mixtures. The membrane and process differ from previously known membranes and processes, in that the feed and permeate streams can both be dry, the membrane need not be water or solvent swollen, and the membrane is characterized by a selectivity for an unsaturated hydrocarbon over a saturated hydrocarbon having the same number of carbon atoms of at least about 20, and a pressure-normalized flux of said unsaturated hydrocarbon of at least about 5{times}10{sup {minus}6}cm{sup 3}(STP)/cm{sup 2}{center_dot}s{center_dot}cmHg, said flux and selectivity being measured with a gas mixture containing said unsaturated and saturated hydrocarbons, and in a substantially dry environment. 4 figs.

  8. Hydrogen Selective Exfoliated Zeolite Membranes

    SciTech Connect (OSTI)

    Tsapatsis, Michael; Daoutidis, Prodromos; Elyassi, Bahman; Lima, Fernando; Iyer, Aparna; Agrawal, Kumar; Sabnis, Sanket

    2014-09-30

    The objective of this project was to develop and evaluate an innovative membrane technology at process conditions that would be representative of Integrated Gasification Combined Cycle (IGCC) advanced power generation with pre-combustion capture of carbon dioxide (CO2). This research focused on hydrogen (H2)-selective zeolite membranes that could be utilized to separate conditioned syngas into H2-rich and CO2-rich components. Both experiments and process design and optimization calculations were performed to evaluate the concept of ultra-thin membranes made from zeolites nanosheets. In this work, efforts in the laboratory were made to tackle two fundamental challenges in application of zeolite membranes in harsh industrial environments, namely, membrane thickness and membrane stability. Conventional zeolite membranes have thicknesses in the micron range, limiting their performance. In this research, we developed a method for fabrication of ultimately thin zeolite membranes based on zeolite nanosheets. A range of layered zeolites (MWW, RWR, NSI structure types) suitable for hydrogen separation was successfully exfoliated to their constituent nanosheets. Further, membranes were made from one of these zeolites, MWW, to demonstrate the potential of this group of materials. Moreover, long-term steam stability of these zeolites (up to 6 months) was investigated in high concentrations of steam (35 mol% and 95 mole%), high pressure (10 barg), and high temperatures (350 oC and 600 oC) relevant to conditions of water-gas-shift and steam methane reforming reactions. It was found that certain nanosheets are stable, and that stability depends on the concentration of structural defects. Additionally, models that represent a water-gas-shift (WGS) membrane reactor equipped with the zeolite membrane were developed for systems studies. These studies had the aim of analyzing the effect of the membrane reactor integration into IGCC plants in terms of performance and economic aspects of the plants. Specifically, simulation and design optimization studies were performed using the developed stand-alone membrane reactor models to identify the membrane selectivity and permeance characteristics necessary to achieve desired targets of CO2 capture and H2 recovery, as well as guide the selection of the optimal reactor design that minimizes the membrane cost as a function of its surface area required. The isothermal membrane reactor model was also integrated into IGCC system models using both the MATLAB and Aspen software platforms and techno-economic analyses of the integrated plants have been carried out to evaluate the feasibility of replacing current technologies for pre-combustion capture by the proposed novel approach in terms of satisfying stream constraints and achieving the DOE target goal of 90% CO2 capture. The results of the performed analyses based on present value of annuity calculations showed break even costs for the membrane reactor within the feasible range for membrane fabrication. However, the predicted membrane performance used in these simulations exceeded the performance achieved experimentally. Therefore, further work is required to improve membrane performance.

  9. PROTON-CONDUCTING DENSE CERAMIC MEMBRANES FOR HYDROGEN SEPARATION

    SciTech Connect (OSTI)

    Jerry Y. S. Lin; Scott Cheng; Vineet Gupta

    2003-12-01

    Dense perovskite-type structured ceramic membranes, SrCe{sub 0.95}Tm{sub 0.05}O{sub 3} (SCTm), of different thickness, were prepared by the dry-press method. Membrane thickness was varied from 3 mm to 150 {micro}m. The hydrogen permeation flux was found to be inversely proportional to the thickness of the dense films, indicating that the bulk diffusion rather than the surface reaction played a dominant role in the H{sub 2} transport through these dense membranes within the studied thickness range. Hydrogen permeation flux increases with increasing upstream hydrogen partial pressure and decreasing downstream hydrogen partial pressure. The activation energy for hydrogen permeation through the SCTm membrane is about 116 kJ/mol in 600-700 C and 16 kJ/mol in 750-950 C. This indicates a change in the electrical and protonic conduction mechanism at around 700 C. Pd-Cu thin films were synthesized with elemental palladium and copper targets by the sequential R.F. sputter deposition on porous substrates. Pd-Cu alloy films could be formed after proper annealing. The deposited Pd-Cu films were gas-tight. This result demonstrated the feasibility of obtaining an ultrathin SCTm film by the sequential sputter deposition of Sr, Ce and Tm metals followed by proper annealing and oxidation. Such ultrathin SCTm membranes will offer sufficiently high hydrogen permeance for practical applications.

  10. High resolution neutron imaging of water in the polymer electrolyte fuel cell membrane

    SciTech Connect (OSTI)

    Mukherjee, Partha P [Los Alamos National Laboratory; Makundan, Rangachary [Los Alamos National Laboratory; Spendelow, Jacob S [Los Alamos National Laboratory; Borup, Rodney L [Los Alamos National Laboratory; Hussey, D S [NIST; Jacobson, D L [NIST; Arif, M [NIST

    2009-01-01

    Water transport in the ionomeric membrane, typically Nafion{reg_sign}, has profound influence on the performance of the polymer electrolyte fuel cell, in terms of internal resistance and overall water balance. In this work, high resolution neutron imaging of the Nafion{reg_sign} membrane is presented in order to measure water content and through-plane gradients in situ under disparate temperature and humidification conditions.

  11. Supporting Information for: Ammonium Bicarbonate Transport in Anion Exchange Membranes

    E-Print Network [OSTI]

    films were cast in PTFE molds from 5% (w/v) solutions of polymer in 1-methyl-2-pyrrolidinone (NMP a given film) was achieved by placing the PTFE molds on a level casting plate in a gravity oven (VWR removed from the PTFE molds and soaked in de-ionized (DI) water (18.2 M cm) to extract any residual

  12. Ion Transport in Nanostructured Block Copolymer/Ionic Liquid Membranes

    E-Print Network [OSTI]

    Hoarfrost, Megan Lane

    2012-01-01

    Bee, M. , Quasielastic Neutron Scattering: Principles andBee, M. , Quasielastic Neutron Scattering: Principles andand Quasi-Elastic Neutron Scattering ii 5.1. Introduction

  13. Ion Transport in Nanostructured Block Copolymer/Ionic Liquid Membranes

    E-Print Network [OSTI]

    Hoarfrost, Megan Lane

    2012-01-01

    imide ([Im][TFSI]) and poly(styrene-b-2-vinyl pyridine) (PS-behavior of mixtures of poly(styrene-b-2-vinyl pyridine) (thermal properties of poly(styrene-b-2-vinylpyridine) (PS-b-

  14. Ion Transport in Nanostructured Block Copolymer/Ionic Liquid Membranes

    E-Print Network [OSTI]

    Hoarfrost, Megan Lane

    2012-01-01

    the Joint Center for Artificial Photosynthesis, a DOE Energythe Joint Center for Artificial Photosynthesis, a DOE Energy

  15. Membrane transporters in the relict plastid of malaria parasites

    E-Print Network [OSTI]

    McFadden, Geoff

    . The parasite plastid synthesizes fatty acids, heme, iron sulfur clusters and isoprenoid precursors are fuelled in the absence of photosynthetic capture of energy and carbon was not clear. Here, we describe fatty acids, isoprene subunits, heme and iron sulfur clusters, which might be exported from

  16. Anion Exchange Membranes - Transport/Conductivity | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Delicious Rank EERE:FinancingPetroleum Based Fuels Research at 1 Table ofDepartment of EnergyOperationsAndrewAndy-

  17. Transport diffusion of liquid water and methanol through membranes (Journal

    Office of Scientific and Technical Information (OSTI)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of NaturalDukeWakefieldSulfateSciTechtail.Theory of rare Kaon and PionExperiments (Journallithium(Journal Article)Article) |

  18. Surface Segregation in a PdCu Alloy Hydrogen Separation Membrane

    SciTech Connect (OSTI)

    Miller, J.B.; Matranga, C.S.; Gellman, A.J.

    2007-06-01

    Separation of hydrogen from mixed gas streams is an important step for hydrogen generation technologies, including hydrocarbon reforming and coal/biomass gasification. Dense palladium-based membranes have received significant attention for this application because of palladium’s ability to dissociatively adsorb molecular hydrogen at its surface for subsequent transport of hydrogen atoms through its bulk. Alloying palladium with minor components, like copper, has been shown to improve both the membrane’s structural characteristics and resistance to poisoning of its catalytic surface [1]. Surface segregation—a composition difference between the bulk material and its surface—is common in alloys and can affect important surface processes. Rational design of alloy membranes requires that surface segregation be understood, and possibly controlled. In this work, we examine surface segregation in a polycrystalline Pd70Cu30 hydrogen separation membrane as a function of thermal treatment and adsorption of hydrogen sulfide.

  19. Advanced Membrane Systems: Recovering Wasteful and Hazardous...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    while reducing fuel losses. Compact Membrane Systems, Inc. (CMS) was founded in 1993 in Wilmington, DE, with the acquisition of rights to certain DuPont polymer membrane...

  20. Fullerene-Nafion Composite Recast Membranes

    Broader source: Energy.gov [DOE]

    Presentation on Fullerene-Nafion Composite Recast Membranes to the High Temperature Membrane Working Group Meeting held in Arlington, Virginia, May 26,2005.

  1. Advanced Membrane Systems: Recovering Wasteful and Hazardous...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Advanced Membrane Systems: Recovering Wasteful and Hazardous Fuel Vapors at the Gasoline Tank Advanced Membrane Systems: Recovering Wasteful and Hazardous Fuel Vapors at the...

  2. Advanced Membrane Systems: Recovering Wasteful and Hazardous...

    Broader source: Energy.gov (indexed) [DOE]

    Case study covering Compact Membrane Systems, Inc. and its membrane vapor processor that recovers fuel vapors from gasoline refueling. cmssbircasestudy2010.pdf More Documents &...

  3. Membrane and MEA Accelerated Stress Test Protocols

    Broader source: Energy.gov [DOE]

    This presentation on fuel cell membrane and MEA stress test protocols was given by T. Benjamin at the High Temperature Membrane Working Group Meeting in May 2007.

  4. Acid Doped Membranes for High Temperature PEMFC

    Broader source: Energy.gov [DOE]

    Presentation on Acid Doped Membranes for High Temperature PEMFC to the High Temperature Membrane Working Group, May 25, 2004 in Philadelphia, PA.

  5. New Membranes for PEM Fuel Cells

    Broader source: Energy.gov [DOE]

    Presentation on New Membranes for PEM Fuel Cells to the High Temperature Membrane Working Group Meeting held in Arlington, Virginia, May 26,2005.

  6. Apparatus for tensioning a heliostat membrane

    DOE Patents [OSTI]

    Sallis, Daniel V. (P.O. Box 554, Littleton, CO 80120)

    1986-01-01

    An apparatus for pneumatically or hydraulically tensioning a membrane, which stretched membrane can support a reflective surface for use as a heliostat in a solar energy collection system.

  7. Neuron, Vol. 19, 12711283, December, 1997, Copyright 1997 by Cell Press Vesicular Transport Regulates Monoamine Storage

    E-Print Network [OSTI]

    Sulzer, David

    -University of California plasm, requiring transport into the vesicle, and severalSan Francisco, California 94143 distinctNeuron, Vol. 19, 1271­1283, December, 1997, Copyright ©1997 by Cell Press Vesicular Transport, cocaine and antidepressants act by inhibiting plasma membrane transport, thereby in- creasing the synaptic

  8. Functionalized inorganic membranes for gas separation

    DOE Patents [OSTI]

    Ku, Anthony Yu-Chung (Rexford, NY); Ruud, James Anthony (Delmar, NY); Molaison, Jennifer Lynn (Marietta, GA); Schick, Louis Andrew ,(Delmar, NY); Ramaswamy, Vidya (Niskayuna, NY)

    2008-07-08

    A porous membrane for separation of carbon dioxide from a fluid stream at a temperature higher than about 200.degree. C. with selectivity higher than Knudsen diffusion selectivity. The porous membrane comprises a porous support layer comprising alumina, silica, zirconia or stabilized zirconia; a porous separation layer comprising alumina, silica, zirconia or stabilized zirconia, and a functional layer comprising a ceramic oxide contactable with the fluid stream to preferentially transport carbon dioxide. In particular, the functional layer may be MgO, CaO, SrO, BaO, La.sub.2O.sub.3, CeO.sub.2, ATiO.sub.3, AZrO.sub.3, AAl.sub.2O.sub.4, A.sup.1FeO.sub.3, A.sup.1MnO.sub.3, A.sup.1CoO.sub.3, A.sup.1NiO.sub.3, A.sup.2HfO.sub.3, A.sup.3CeO.sub.3, Li.sub.2ZrO.sub.3, Li.sub.2SiO.sub.3, Li.sub.2TiO.sub.3 or a mixture thereof; wherein A is Mg, Ca, Sr or Ba; A.sup.1 is La, Ca, Sr or Ba; A.sup.2 is Ca, Sr or Ba; and A.sup.3 is Sr or Ba.

  9. From Protein Structure to Function: Ring Cycle for Dilating and...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Pore Print Nuclear pore complexes (NPCs) act as the central gatekeepers for selective transport between the cytoplasm and the nucleus. They allow the exchange of selected proteins...

  10. Structural studies of large architectural nucleoporins and coat proteins

    E-Print Network [OSTI]

    Whittle, James Richardson Ross

    2010-01-01

    The Nuclear Pore Complex (NPC) is a ~50 MDa protein complex that forms the sole conduit for macromolecular transport across the nuclear envelope. It assembles from ~30 proteins, termed nucleoporins or nups, symmetrically ...

  11. Method and apparatus for producing oxygen and nitrogen and membrane therefor

    DOE Patents [OSTI]

    Roman, I.C.; Baker, R.W.

    1985-09-17

    Process and apparatus for the separation and purification of oxygen and nitrogen as well as a novel membrane useful therein are disclosed. The process utilizes novel facilitated transport membranes to selectively transport oxygen from one gaseous stream to another, leaving nitrogen as a byproduct. In the method, an oxygen carrier capable of reversibly binding molecular oxygen is dissolved in a polar organic membrane which separates a gaseous feed stream such as atmospheric air and a gaseous product stream. The feed stream is maintained at a sufficiently high oxygen pressure to keep the oxygen carrier in its oxygenated form at the interface of the feed stream with the membrane, while the product stream is maintained at a sufficiently low oxygen pressure to keep the carrier in its deoxygenated form at the interface of the product stream with the membrane. In an alternate mode of operation, the feed stream is maintained at a sufficiently low temperature and high oxygen pressure to keep the oxygen carrier in its oxygenated form at the interface of the feed stream with the membrane and the product stream is maintained at a sufficiently high temperature to keep the carrier in its deoxygenated form at the interface of the product stream with the membrane. Under such conditions, the carrier acts as a shuttle, picking up oxygen at the feed side of the membrane, diffusing across the membrane as the oxygenated complex, releasing oxygen to the product stream, and then diffusing back to the feed side to repeat the process. Exceptionally and unexpectedly high O[sub 2]/N[sub 2] selectivity, on the order of 10 to 30, is obtained, as well as exceptionally high oxygen permeability, on the order of 6 to 15 [times] 10[sup [minus]8] cm[sup 3]-cm/cm[sup 2]-sec-cmHg, as well as a long membrane life of in excess of 3 months, making the process commercially feasible. 2 figs.

  12. Gas Separations using Ceramic Membranes

    SciTech Connect (OSTI)

    Paul KT Liu

    2005-01-13

    This project has been oriented toward the development of a commercially viable ceramic membrane for high temperature gas separations. A technically and commercially viable high temperature gas separation membrane and process has been developed under this project. The lab and field tests have demonstrated the operational stability, both performance and material, of the gas separation thin film, deposited upon the ceramic membrane developed. This performance reliability is built upon the ceramic membrane developed under this project as a substrate for elevated temperature operation. A comprehensive product development approach has been taken to produce an economically viable ceramic substrate, gas selective thin film and the module required to house the innovative membranes for the elevated temperature operation. Field tests have been performed to demonstrate the technical and commercial viability for (i) energy and water recovery from boiler flue gases, and (ii) hydrogen recovery from refinery waste streams using the membrane/module product developed under this project. Active commercializations effort teaming with key industrial OEMs and end users is currently underway for these applications. In addition, the gas separation membrane developed under this project has demonstrated its economical viability for the CO2 removal from subquality natural gas and landfill gas, although performance stability at the elevated temperature remains to be confirmed in the field.

  13. Membrane Separations of Liquid Mixtures 

    E-Print Network [OSTI]

    Lloyd, D. R.

    1985-01-01

    , respectively. 147 A membrane (defined below) can be used to separate gas-phase mixtures and liquid-phase mixtures. This paper deals almost exclusively with the latter - a catagory of separation that includes dissolved and suspended solids in liquids... valuable. I ESL-IE-85-05-27 Proceedings from the Seventh National Industrial Energy Technology Conference, Houston, TX, May 12-15, 1985 The membrane may be a gas [56 L a liquid [57,15], or a solid [11-23]. Solid polymeric membranes,and to a lesser extent...

  14. Thermally tolerant multilayer metal membrane

    DOE Patents [OSTI]

    Dye, Robert C. (Los Alamos, NM); Snow, Ronny C. (Los Alamos, NM)

    2001-01-01

    A composite metal membrane including a first metal layer of a Group IVB or Group VB metal sandwiched between two layers of a Group VIIIB metal selected from the group consisting of palladium, platinum, nickel, rhodium, iridium, cobalt, and alloys thereof, and a non-continuous layer of a metal chalcogenide upon one layer of the Group VIIIB metal is disclosed together with a process for the recovery of hydrogen from a gaseous mixture using such a composite membrane and a process for forming such a composite metal membrane.

  15. A Plasma Membrane E-MAP Reveals Links Between the Eisosome, Sphingolipid Metabolism and

    E-Print Network [OSTI]

    Shamir, Ron

    A Plasma Membrane E-MAP Reveals Links Between the Eisosome, Sphingolipid Metabolism and Endosomal between pairs of proteins. The predictive power of the plasma membrane E-MAP (blue) is comparable.5 0.0 1.5 3.0 S-scores MYO5 BNR1 BCK1 SYP1 BBC1 SLA1 ARC18 SLT2 CAP1 EDE1 CLA4BEM3 ABP1 CAP2 TWF1 BZZ1

  16. Transportation Plan 

    E-Print Network [OSTI]

    Boreo, Andrea; Li, Wei; Wunnenbuger, Douglas; Giusti, Cecilia; Cooper, John T.; Masterson, Jaimie

    2015-01-01

    Mobility throughout a community ensures freedom of movement and enhances quality of life. Traffic congestion, pollution, urban sprawl, social exclusion, safety and health can decrease mobility and should be a part of a sustainable transportation...

  17. electrifyingthefuture transportation

    E-Print Network [OSTI]

    Birmingham, University of

    programme of electrification and the potential introduction of diesel hybrids. The Department for Transport vehicles Wind turbine systems Industrial equipment The lab has full ethernet capability which will enable

  18. Shear-response of the spectrin dimer-tetramer equilibrium in the red blood cell membrane

    SciTech Connect (OSTI)

    An, Xiuli; Lecomte, M. Christine; Chasis, Joel Anne; Mohandas, Narla; Gratzer, Walter

    2003-06-18

    The red cell membrane derives its elasticity and resistance to mechanical stresses from the membrane skeleton, a network composed of spectrin tetramers. These are formed by the head-to-head association of pairs of heterodimers attached at their ends to junctional complexes of several proteins. Here we examine the dynamics of the spectrin dimer-dimer association in the intact membrane. We show that univalent fragments of spectrin, containing the dimer self-association site, will bind to spectrin on the membrane and thereby disrupt the continuity of the protein network. This results in impairment of the mechanical stability of the membrane. When, moreover, the cells are subjected to a continuous low level of shear, even at room temperature, the incorporation of the fragments and the consequent destabilization of the membrane are greatly accentuated. It follows that a modest shearing force, well below that experienced by the red cell in the circulation, is sufficient to sever dimer-dimer links in the network. Our results imply (1) that the membrane accommodates the enormous distortions imposed on it during the passage of the cell through the micro vasculature by means of local dissociation of spectrin tetramers to dimers, (2) that the network in situ is in a dynamic state and under goes a ''breathing'' action of tetramer dissociation and re-formation.

  19. Calcium-Mediated Regulation of Proton-Coupled Sodium Transport - Final Report

    SciTech Connect (OSTI)

    Schumaker, Karen S

    2013-10-24

    The long-term goal of our experiments was to understand mechanisms that regulate energy coupling by ion currents in plants. Activities of living organisms require chemical, mechanical, osmotic or electrical work, the energy for which is supplied by metabolism. Adenosine triphosphate (ATP) has long been recognized as the universal energy currency, with metabolism supporting the synthesis of ATP and the hydrolysis of ATP being used for the subsequent work. However, ATP is not the only energy currency in living organisms. A second and very different energy currency links metabolism to work by the movement of ions passing from one side of a membrane to the other. These ion currents play a major role in energy capture and they support a range of physiological processes from the active transport of nutrients to the spatial control of growth and development. In Arabidopsis thaliana (Arabidopsis), the activity of a plasma membrane Na+/H+ exchanger, SALT OVERLY SENSITIVE1 (SOS1), is essential for regulation of sodium ion homeostasis during plant growth in saline conditions. Mutations in SOS1 result in severely reduced seedling growth in the presence of salt compared to the growth of wild type. SOS1 is a secondary active transporter coupling movement of sodium ions out of the cell using energy stored in the transplasma membrane proton gradient, thereby preventing the build-up of toxic levels of sodium in the cytosol. SOS1 is regulated by complexes containing the SOS2 and CALCINEURIN B-LIKE10 (CBL10) or SOS3 proteins. CBL10 and SOS3 (also identified as CBL4) encode EF-hand calcium sensors that interact physically with and activate SOS2, a serine/threonine protein kinase. The CBL10/SOS2 or SOS3/SOS2 complexes then activate SOS1 Na+/H+ exchange activity. We completed our studies to understand how SOS1 activity is regulated. Specifically, we asked: (1) how does CBL10 regulate SOS1 activity? (2) What role do two putative CBL10-interacting proteins play in SOS1 regulation? (3) Are there differences in the regulation and/or activity of SOS1 in plants differing in their adaptation to salinity?

  20. Composite solid polymer electrolyte membranes

    DOE Patents [OSTI]

    Formato, Richard M. (Shrewsbury, MA); Kovar, Robert F. (Wrentham, MA); Osenar, Paul (Watertown, MA); Landrau, Nelson (Marlborough, MA); Rubin, Leslie S. (Newton, MA)

    2001-06-19

    The present invention relates to composite solid polymer electrolyte membranes (SPEMs) which include a porous polymer substrate interpenetrated with an ion-conducting material. SPEMs of the present invention are useful in electrochemical applications, including fuel cells and electrodialysis.