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1

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...

2

Conformational Exchange in a Membrane Transport Protein Is Altered in Protein Crystals  

SciTech Connect (OSTI)

Successful macromolecular crystallography requires solution conditions that may alter the conformational sampling of a macromolecule. Here, site-directed spin labeling is used to examine a conformational equilibrium within BtuB, the Escherichia coli outer membrane transporter for vitamin B{sub 12}. Electron paramagnetic resonance (EPR) spectra from a spin label placed within the N-terminal energy coupling motif (Ton box) of BtuB indicate that this segment is in equilibrium between folded and unfolded forms. In bilayers, substrate binding shifts this equilibrium toward the unfolded form; however, EPR spectra from this same spin-labeled mutant indicate that this unfolding transition is blocked in protein crystals. Moreover, crystal structures of this spin-labeled mutant are consistent with the EPR result. When the free energy difference between substates is estimated from the EPR spectra, the crystal environment is found to alter this energy by 3 kcal/mol when compared to the bilayer state. Approximately half of this energy change is due to solutes or osmolytes in the crystallization buffer, and the remainder is contributed by the crystal lattice. These data provide a quantitative measure of how a conformational equilibrium in BtuB is modified in the crystal environment, and suggest that more-compact, less-hydrated substates will be favored in protein crystals.

D Freed; P Horanyi; M Wiener; D Cafiso

2011-12-31T23:59:59.000Z

3

Conformational Exchange in a Membrane Transport Protein Is Altered in Protein Crystals  

SciTech Connect (OSTI)

Successful macromolecular crystallography requires solution conditions that may alter the conformational sampling of a macromolecule. Here, site-directed spin labeling is used to examine a conformational equilibrium within BtuB, the Escherichia coli outer membrane transporter for vitamin B{sub 12}. Electron paramagnetic resonance (EPR) spectra from a spin label placed within the N-terminal energy coupling motif (Ton box) of BtuB indicate that this segment is in equilibrium between folded and unfolded forms. In bilayers, substrate binding shifts this equilibrium toward the unfolded form; however, EPR spectra from this same spin-labeled mutant indicate that this unfolding transition is blocked in protein crystals. Moreover, crystal structures of this spin-labeled mutant are consistent with the EPR result. When the free energy difference between substates is estimated from the EPR spectra, the crystal environment is found to alter this energy by 3 kcal/mol when compared to the bilayer state. Approximately half of this energy change is due to solutes or osmolytes in the crystallization buffer, and the remainder is contributed by the crystal lattice. These data provide a quantitative measure of how a conformational equilibrium in BtuB is modified in the crystal environment, and suggest that more-compact, less-hydrated substates will be favored in protein crystals.

Freed, Daniel M.; Horanyi, Peter S.; Wiener, Michael C.; Cafiso, David S. (UV)

2010-09-27T23:59:59.000Z

4

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:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsrucLas ConchasPassiveSubmittedStatus TomAbout » Staff125,849|Structures for Three Membrane

5

OXYGEN TRANSPORT CERAMIC MEMBRANES  

SciTech Connect (OSTI)

This report covers the following tasks: 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; and Task 6--Measure kinetics of oxygen uptake and transport in ceramic membrane materials under commercially relevant conditions using isotope labeling techniques.

Dr. Sukumar Bandopadhyay; Dr. Nagendra Nagabhushana

2002-04-01T23:59:59.000Z

6

OXYGEN TRANSPORT CERAMIC MEMBRANES  

SciTech Connect (OSTI)

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.

Dr. Sukumar Bandopadhyay; Dr. Nagendra Nagabhushana

2000-10-01T23:59:59.000Z

7

Hydrogen transport membranes  

DOE Patents [OSTI]

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.

Mundschau, Michael V.

2005-05-31T23:59:59.000Z

8

OXYGEN TRANSPORT CERAMIC MEMBRANES  

SciTech Connect (OSTI)

In the present quarter, oxygen transport perovskite ceramic membranes are evaluated for strength and fracture in oxygen gradient conditions. Oxygen gradients are created in tubular membranes by insulating the inner surface from the reducing environment by platinum foils. Fracture in these test conditions is observed to have a gradient in trans and inter-granular fracture as opposed to pure trans-granular fracture observed in homogeneous conditions. Fracture gradients are reasoned to be due to oxygen gradient set up in the membrane, variation in stoichiometry across the thickness and due to varying decomposition of the parent perovskite. The studies are useful in predicting fracture criterion in actual reactor conditions and in understanding the initial evolution of fracture processes.

Dr. Sukumar Bandopadhyay; Dr. Nagendra Nagabhushana

2002-07-01T23:59:59.000Z

9

OXYGEN TRANSPORT CERAMIC MEMBRANES  

SciTech Connect (OSTI)

In the present quarter, the possibility of using a more complex interfacial engineering approach to the development of reliable and stable oxygen transport perovskite ceramic membranes/metal seals is discussed. Experiments are presented and ceramic/metal interactions are characterized. Crack growth and fracture toughness of the membrane in the reducing conditions are also discussed. Future work regarding this approach is proposed are evaluated for strength and fracture in oxygen gradient conditions. Oxygen gradients are created in tubular membranes by insulating the inner surface from the reducing environment by platinum foils. Fracture in these test conditions is observed to have a gradient in trans and inter-granular fracture as opposed to pure trans-granular fracture observed in homogeneous conditions. Fracture gradients are reasoned to be due to oxygen gradient set up in the membrane, variation in stoichiometry across the thickness and due to varying decomposition of the parent perovskite. The studies are useful in predicting fracture criterion in actual reactor conditions and in understanding the initial evolution of fracture processes.

Dr. Sukumar Bandopadhyay; Dr. Nagendra Nagabhushana

2003-01-01T23:59:59.000Z

10

OXYGEN TRANSPORT CERAMIC MEMBRANES  

SciTech Connect (OSTI)

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.

Dr. Sukumar Bandopadhyay; Dr. Nagendra Nagabhushana

2003-01-01T23:59:59.000Z

11

OXYGEN TRANSPORT CERAMIC MEMBRANES  

SciTech Connect (OSTI)

Conversion of natural gas to liquid fuels and chemicals is a major goal for the Nation as it enters the 21st Century. Technically robust and economically viable processes are needed to capture the value of the vast reserves of natural gas on Alaska's North Slope, and wean the Nation from dependence on foreign petroleum sources. Technologies that are emerging to fulfill this need are all based syngas as an intermediate. Syngas (a mixture of hydrogen and carbon monoxide) is a fundamental building block from which chemicals and fuels can be derived. Lower cost syngas translates directly into more cost-competitive fuels and chemicals. The currently practiced commercial technology for making syngas is either steam methane reforming (SMR) or a two-step process involving cryogenic oxygen separation followed by natural gas partial oxidation (POX). These high-energy, capital-intensive processes do not always produce syngas at a cost that makes its derivatives competitive with current petroleum-based fuels and chemicals. This project has the following 6 main tasks: 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.

Dr. Sukumar Bandopadhyay; Dr. Nagendra Nagabhushana

2001-12-01T23:59:59.000Z

12

Oxygen Transport Ceramic Membranes  

SciTech Connect (OSTI)

The present quarterly report describes some of the investigations on the structural properties of dense OTM bars provided by Praxair and studies on newer composition of Ti doped LSF. Thermogravimetric analysis (TGA) was carried out on La{sub 0.2}Sr{sub 0.8}Fe{sub 0.55}Ti{sub 0.45}O{sub 3-{delta}} to investigate oxygen deficiency ({delta}) of the sample. The TGA was performed in a controlled atmosphere using oxygen, argon, carbon monoxide and carbon dioxide with adjustable gas flow rates. In this experiment, the weight loss and gain of La{sub 0.2}Sr{sub 0.8}Fe{sub 0.55}Ti{sub 0.45}O{sub 3-{delta}} was directly measured by TGA. The weight change of the sample was evaluated at between 600 and 1250 C in air or 1000 C as a function of oxygen partial pressure. The oxygen deficiencies calculated from TGA data as a function of oxygen activity and temperature will be estimated and compared with that from neutron diffraction measurement in air. The LSFT and LSFT/CGO membranes were fabricated from the powder obtained from Praxair Specialty Ceramics. The sintered membranes were subjected to microstructure analysis and hardness analysis. The LSFT membrane is composed of fine grains with two kinds of grain morphology. The grain size distribution was characterized using image analysis. In LSFT/CGO membrane a lot of grain pullout was observed from the less dense, porous phase. The hardness of the LSFT and dual phase membranes were studied at various loads. The hardness values obtained from the cross section of the membranes were also compared to that of the values obtained from the surface. An electrochemical cell has been designed and built for measurements of the Seebeck coefficient as a function of temperature and pressure. Measurements on La{sub 0.2}Sr{sub 0.8}Fe{sub 0.55}Ti{sub 0.45}O{sub 3-{delta}} as a function of temperature an oxygen partial pressure are reported. Further analysis of the dilatometry data obtained previously is presented. A series of isotope transients under air separation mode (small gradient) were completed on the membrane of LSCrF-2828 at 900 C. Low pO{sub 2} atmospheres based on with CO-CO{sub 2} mixtures have also been admitted to the delivery side of the LSCrF-2828 membrane to produce the gradients which exist under syngas generation conditions. The CO-CO{sub 2} mixtures have normal isotopic {sup 18}O abundances. The evolution of {sup 18}O on the delivery side in these experiments after an {sup 18}O pulse on the air side reveals a wealth of information about the oxygen transport processes.

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

2005-02-01T23:59:59.000Z

13

Oxygen Transport Ceramic Membranes  

SciTech Connect (OSTI)

The present quarterly report describes some of the initial studies on newer compositions and also includes newer approaches to address various materials issues such as in metal-ceramic sealing. The current quarter's research has also focused on developing a comprehensive reliability model for predicting the structural behavior of the membranes in realistic conditions. In parallel to industry provided compositions, models membranes have been evaluated in varying environment. Of importance is the behavior of flaws and generation of new flaws aiding in fracture. Fracture mechanics parameters such as crack tip stresses are generated to characterize the influence of environment. Room temperature slow crack growth studies have also been initiated in industry provided compositions. The electrical conductivity and defect chemistry of an A site deficient compound (La{sub 0.55}Sr{sub 0.35}FeO{sub 3}) was studied. A higher conductivity was observed for La{sub 0.55}Sr{sub 0.35}FeO{sub 3} than that of La{sub 0.60}Sr{sub 0.40}FeO{sub 3} and La{sub 0.80}Sr{sub 0.20}FeO{sub 3}. Defect chemistry analysis showed that it was primarily contributed by a higher carrier concentration in La{sub 0.55}Sr{sub 0.35}FeO{sub 3}. Moreover, the ability for oxygen vacancy generation is much higher in La{sub 0.55}Sr{sub 0.35}FeO{sub 3} as well, which indicates a lower bonding strength between Fe-O and a possible higher catalytic activity for La{sub 0.55}Sr{sub 0.35}FeO{sub 3}. The program continued to investigate the thermodynamic properties (stability and phase separation behavior) and total conductivity of prototype membrane materials. The data are needed together with the kinetic information to develop a complete model for the membrane transport. Previous report listed initial measurements on a sample of La{sub 0.2}Sr{sub 0.8}Fe{sub 0.55}Ti{sub 0.45}O{sub 3-x} prepared in-house by Praxair. Subsequently, a second sample of powder from a larger batch of sample were characterized and compared with the results from the previous batch.

S. Bandopadhyay; N. Nagabhushana; Thomas W. Eagar; Harold R. Larson; Raymundo Arroyave; X.-D Zhou; Y.-W. Shin; H.U. Anderson; Nigel Browning; Alan Jacobson; C.A. Mims

2003-11-01T23:59:59.000Z

14

Oxygen Transport Ceramic Membranes  

SciTech Connect (OSTI)

The present quarterly report describes some of the investigations on the structural properties of dense OTM bars provided by Praxair and studies on newer composition of Ti doped LSF. In this report, in situ neutron diffraction was used to characterize the chemical and structural properties of La{sub 0.2}Sr{sub 0.8}Fe{sub 0.55}Ti{sub 0.45}O{sub 3-{delta}} (here after as L2SF55T) specimen, which was subject to measurements of neutron diffraction from room temperature to 900 C. It was found that space group of R3c yielded a better refinement than a cubic structure of Pm3m. Oxygen occupancy was nearly 3 in the region from room temperature to 700 C, above which the occupancy decreased due to oxygen loss. Dense OTM bars provided by Praxair were loaded to fracture at varying stress rates. Studies were done at room temperature in air and at 1000 C in a specified environment to evaluate slow crack growth behavior. The X-Ray data and fracture mechanisms points to non-equilibrium decomposition of the LSFCO OTM membrane. The non-equilibrium conditions could probably be due to the nature of the applied stress field (stressing rates) and leads to transition in crystal structures and increased kinetics of decomposition. The formations of a Brownmillerite or Sr2Fe2O5 type structures, which are orthorhombic are attributed to the ordering of oxygen vacancies. The cubic to orthorhombic transitions leads to 2.6% increase in strains and thus residual stresses generated could influence the fracture behavior of the OTM membrane. Continued investigations on the thermodynamic properties (stability and phase-separation behavior) and total conductivity of prototype membrane materials were carried out. The data are needed together with the kinetic information to develop a complete model for the membrane transport. Previously characterization, stoichiometry and conductivity measurements for samples of La{sub 0.2}Sr{sub 0.8}Fe{sub 0.55}Ti{sub 0.45}O{sub 3-{delta}} were reported. In this report, measurements of the chemical and thermal expansion as a function of temperature and p{sub O2} are described.

S. Bandopadhyay; N. Nagabhushana; X.-D Zhou; Q. Cai; J. Yang; W.B. Yelon; W.J. James; H.U. Anderson; Alan Jacobson; C.A. Mims

2004-05-01T23:59:59.000Z

15

Oxygen Transport Ceramic Membranes  

SciTech Connect (OSTI)

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.

S. Bandopadhyay; N. Nagabhushana

2003-08-07T23:59:59.000Z

16

Oxygen Transport Membranes  

SciTech Connect (OSTI)

The focus of this research was to develop new membrane materials by synthesizing different compounds and determining their defect structures, crystallographic structures and electrical properties. In addition to measuring electrical conductivity, oxygen vacancy concentration was also evaluated using thermogravimetry, Neutron diffraction and Moessbauer Spectroscopy. The reducing conditions (CO{sub 2}/CO/H{sub 2} gas mixtures with steam) as encountered in a reactor environment can be expected to have significant influence on the mechanical properties of the oxides membranes. Various La based materials with and without Ti were selected as candidate membrane materials for OTM. The maximum electrical conductivity of LSF in air as a function of temperature was achieved at < 600 C and depends on the concentration of Sr (acceptor dopant). Oxygen occupancy in LSF was estimated using Neutron diffractometry and Moessbauer Spectroscopy by measuring magnetic moment changes depending on the Fe{sup 3+} and Fe{sup 4+} ratio. After extensive studies of candidate materials, lanthanum ferrites (LSF and LSFT) were selected as the favored materials for the oxygen transport membrane (OTM). LSF is a very good material for an OTM because of its high electronic and oxygen ionic conductivity if long term stability and mechanical strength are improved. LSFT not only exhibits p-type behavior in the high oxygen activity regime, but also has n-type conduction in reducing atmospheres. Higher concentrations of oxygen vacancies in the low oxygen activity regime may improve the performance of LSFT as an OTM. The hole concentration is related to the difference in the acceptor and donor concentration by the relation p = [Sr'{sub La}]-[Ti{sm_bullet}{sub Fe}]. The chemical formulation predicts that the hole concentration is, p = 0.8-0.45 or 0.35. Experimental measurements indicated that p is about {approx} 0.35. The activation energy of conduction is 0.2 eV which implies that LSCF conducts via the small polaron conduction mechanism. Scanning transmission electron microscopy (STEM) and electron energy loss spectroscopy (EELS) were used to develop strategies to detect and characterize vacancy creation, dopant segregations and defect association in the oxygen conducting membrane material. The pO{sub 2} and temperature dependence of the conductivity, non-stoichiometry and thermal-expansion behavior of compositions with increasing complexity of substitution on the perovskite A and B sites were studied. Studies with the perovskite structure show anomalous behavior at low oxygen partial pressures (<10{sup -5} atm). The anomalies are due to non-equilibrium effects and can be avoided by using very strict criteria for the attainment of equilibrium. The slowness of the oxygen equilibration kinetics arises from two different mechanisms. In the first, a two phase region occurs between an oxygen vacancy ordered phase such as brownmillerite SrFeO{sub 2.5} and perovskite SrFeO{sub 3-x}. The slow kinetics is associated with crossing the two phase region. The width of the miscibility gap decreases with increasing temperature and consequently the effect is less pronounced at higher temperature. The preferred kinetic pathway to reduction of perovskite ferrites when the vacancy concentration corresponds to the formation of significant concentrations of Fe{sup 2+} is via the formation of a Ruddlesden-Popper (RP) phases as clearly observed in the case of La{sub 0.5}Sr{sub 0.5}FeO{sub 3-x} where LaSrFeO{sub 4} is found together with Fe. In more complex compositions, such as LSFTO, iron or iron rich phases are observed locally with no evidence for the presence of discrete RP phase. Fracture strength of tubular perovskite membranes was determined in air and in reducing atmospheric conditions. The strength of the membrane decreased with temperature and severity of reducing conditions although the strength distribution (Weibull parameter, m) was relatively unaltered. Surface and volume dominated the fracture origins and the overall fracture was purely transgranular. The dual phas

S. Bandopadhyay

2008-08-30T23:59:59.000Z

17

Nanoengineered membranes for controlled transport  

DOE Patents [OSTI]

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.

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

2010-01-05T23:59:59.000Z

18

Oxygen Transport Ceramic Membranes  

SciTech Connect (OSTI)

The present quarterly report describes some of the investigations on the structural properties of dense OTM bars provided by Praxair and studies on newer composition of Ti doped LSF. In this report, Moessbauer spectroscopy was used to study the local environmentals of LSFT with various level of oxygen deficiency. Ionic valence state, magnetic interaction and influence of Ti on superexchange are discussed Stable crack growth studies on Dense OTM bars provided by Praxair were done at elevated temperature, pressure and elevated conditions. Post-fracture X-ray data of the OTM fractured at 1000 C in environment were refined by FullProf code and results indicate a distortion of the parent cubic perovskite to orthorhombic structure with reduced symmetry. TGA-DTA studies on the post-fracture samples also indicated residual effect arising from the thermal and stress history of the samples. An electrochemical cell has been designed and built for measurements of the Seebeck coefficient as a function of temperature and pressure. The initial measurements on La{sub 0.2}Sr{sub 0.8}Fe{sub 0.55}Ti{sub 0.45}O{sub 3-{delta}} are reported. Neutron diffraction measurements of the same composition are in agreement with both the stoichiometry and the kinetic behavior observed in coulometric titration measurements. A series of isotope transients under air separation mode (small gradient) were completed on the membrane of LSCrF-2828 at 900 C. Low pO{sub 2} atmospheres based on with CO-CO{sub 2} mixtures have also been admitted to the delivery side of the LSCrF-2828 membrane to produce the gradients which exist under syngas generation conditions. The COCO{sub 2} mixtures have normal isotopic {sup 18}O abundances. The evolution of {sup 18}O on the delivery side in these experiments after an {sup 18}O pulse on the air side reveals a wealth of information about the oxygen transport processes.

S. Bandopadhyay; N. Nagabhushana; X.-D Zhou; Q. Cai; J. Yang; W.B. Yelon; W.J. James; H.U. Anderson; Alan Jacobson; C.A. Mims

2004-10-01T23:59:59.000Z

19

Energy use by biological protein transport pathways  

E-Print Network [OSTI]

residing within energy-conserving membranes use transmembrane ion gradients to drive substrate transport receptors impart specificity to a targeting route, and transport across or into the membrane is typicallyEnergy use by biological protein transport pathways Nathan N. Alder1 and Steven M. Theg2 1

Economou, Tassos

20

Oxygen Transport Ceramic Membranes  

SciTech Connect (OSTI)

The present quarterly report describes some of the investigations on the structural properties of dense OTM bars provided by Praxair and studies on newer composition of Ti doped LSF. In this report, in situ neutron diffraction was used to characterize the chemical and structural properties of La{sub 0.2}Sr{sub 0.8}Fe{sub 0.55}Ti{sub 0.45}O{sub 3-{delta}} (here after as L2SF55T) specimen, which was subject to measurements of neutron diffraction from room temperature to 900 C in N{sub 2}. Space group of R3c was found to result in a better refinement and is used in this study. The difference for crystal structure, lattice parameters and local crystal chemistry for LSFT nearly unchanged when gas environment switched from air to N{sub 2}. Stable crack growth studies on Dense OTM bars provided by Praxair were done at room temperature in air. A bridge-compression fixture was fabricated to achieve stable pre-cracks from Vickers indents. Post fracture evaluation indicated stable crack growth from the indent and a regime of fast fracture. Post-fracture X-ray data of the OTM fractured at 1000 C in environment were refined by FullProf code and results indicate a distortion of the parent cubic perovskite to orthorhombic structure with reduced symmetry. TGA-DTA studies on the post-fracture samples also indicated residual effect arising from the thermal and stress history of the samples. The thermal and chemical expansion of La{sub 0.2}Sr{sub 0.8}Fe{sub 0.55}Ti{sub 0.45}O{sub 3-{delta}} were studied at 800 {le} T {le} 1000 C and at {approx} 1 x 10{sup -15} {le} pO{sub 2} {le} 0.21 atm. The thermal expansion coefficient of the sample was calculated from the dilatometric analysis in the temperature range between room temperature and 1200 C in air. A series of isotope transients under air separation mode (small gradient) were completed on the membrane of LSCrF-2828 at 900 C. Low pO{sub 2} atmospheres based on with CO-CO{sub 2} mixtures have also been admitted to the delivery side of the LSCrF-2828 membrane to produce the gradients which exist under syngas generation conditions. The CO-CO{sub 2} mixtures have normal isotopic {sup 18}O abundances. The evolution of {sup 18}O on the delivery side in these experiments after an {sup 18}O pulse on the air side reveals a wealth of information about the oxygen transport processes.

S. Bandopadhyay; N. Nagabhushana; X.-D Zhou; Q. Cai; J. Yang; W.B. Yelon; W.J. James; H.U. Anderson; Alan Jacobson; C.A. Mims

2004-05-01T23:59:59.000Z

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We encourage you to perform a real-time search of NLEBeta
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21

Oxygen Transport Ceramic Membranes  

SciTech Connect (OSTI)

The present quarterly report describes some of the investigations on the structural properties of dense OTM bars provided by Praxair and studies on newer composition of Ti doped LSF. In the current research, the electrical conductivity and Seebeck coefficient were measured as a function of temperature in air. Based on these measurements, the charge carrier concentration, net acceptor dopant concentration, activation energy of conduction and mobility were estimated. The studies on the fracture toughness of the LSFT and dual phase membranes at room temperature have been completed and reported previously. The membranes that are exposed to high temperatures at an inert and a reactive atmosphere undergo many structural and chemical changes which affects the mechanical properties. To study the effect of temperature on the membranes when exposed to an inert environment, the membranes (LAFT and Dual phase) were heat treated at 1000 C in air and N{sub 2} atmosphere and hardness and fracture toughness of the membranes were studied after the treatment. The indentation method was used to find the fracture toughness and the effect of the heat treatment on the mechanical properties of the membranes. Further results on the investigation of the origin of the slow kinetics on reduction of ferrites have been obtained. The slow kinetics appears to be related to a non-equilibrium reduction pathway that initially results in the formation of iron particles. At long times, equilibrium can be reestablished with recovery of the perovskite phase. 2-D modeling of oxygen movement has been undertaken in order to fit isotope data. The model will serve to study ''frozen'' profiles in patterned or composite membranes.

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

2005-11-01T23:59:59.000Z

22

Oxygen Transport Ceramic Membranes  

SciTech Connect (OSTI)

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.

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

2006-05-01T23:59:59.000Z

23

Composite oxygen transport membrane  

DOE Patents [OSTI]

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.

Christie, Gervase Maxwell; Lane, Jonathan A.

2014-08-05T23:59:59.000Z

24

OXYGEN TRANSPORT CERAMIC MEMBRANES  

SciTech Connect (OSTI)

This is the fifth quarterly report on a new study to develop a ceramic membrane/metal joint. Results of wetting experiments on commercially available Nickel based brazing alloys on perovskite surfaces are described. Additionally, experimental and numerical investigations on the strength of concentric ceramic/metal joints are presented.

Dr. Sukumar Bandopadhyay; Dr. Nagendra Nagabhushana

2001-02-01T23:59:59.000Z

25

Ion transport through cell membrane channels  

E-Print Network [OSTI]

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

Jan Gomulkiewicz; Jacek Miekisz; Stanislaw Miekisz

2007-06-05T23:59:59.000Z

26

OXYGEN TRANSPORT CERAMIC MEMBRANES  

SciTech Connect (OSTI)

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.

Dr. Sukumar Bandopadhyay; Dr. Nagendra Nagabhushana

2000-07-01T23:59:59.000Z

27

Oxygen Transport Ceramic Membranes  

SciTech Connect (OSTI)

The present quarterly report describes some of the investigations on the structural properties of dense OTM bars provided by Praxair and studies on newer composition of Ti doped LSF. In the previous research, the reference point of oxygen occupancy was determined and verified. In the current research, the oxygen occupancy was investigated at 1200 C as a function of oxygen activity and compared with that at 1000 C. The cause of bumps at about 200 C was also investigated by using different heating and cooling rates during TGA. The fracture toughness of LSFT and dual phase membranes at room temperature is an important mechanical property. Vicker's indentation method was used to evaluate this toughness. Through this technique, a K{sub Ic} (Mode-I Fracture Toughness) value is attained by means of semi-empirical correlations between the indentation load and the length of the cracks emanating from the corresponding Vickers indentation impression. In the present investigation, crack propagation behavior was extensively analyzed in order to understand the strengthening mechanisms involved in the non-transforming La based ceramic composites. Cracks were generated using Vicker's indenter and used to identify and evaluate the toughening mechanisms involved. Preliminary results of an electron microscopy study of the origin of the slow kinetics on reduction of ferrites have been obtained. The slow kinetics appear to be related to a non-equilibrium reduction pathway that initially results in the formation of iron particles. At long times, equilibrium can be reestablished with recovery of the perovskite phase. Modeling of the isotopic transients on operating membranes (LSCrF-2828 at 900 C) and a ''frozen'' isotope profile have been analyzed in conjunction with a 1-D model to reveal the gradient in oxygen diffusivity through the membrane under conditions of high chemical gradients.

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

2005-08-01T23:59:59.000Z

28

Oxygen Transport Ceramic Membranes  

SciTech Connect (OSTI)

The present quarterly report describes some of the investigations on the structural properties of dense OTM bars provided by Praxair and studies on newer composition of Ti doped LSF. The in situ electrical conductivity and Seebeck coefficient measurements were made on LSFT at 1000 and 1200 C over the oxygen activity range from air to 10{sup -15} atm. The electrical conductivity measurements exhibited a p to n type transition at an oxygen activity of 1 x 10{sup -10} at 1000 C and 1 x 10{sup -6} at 1200 C. Thermogravimetric studies were also carried out over the same oxygen activities and temperatures. Based on the results of these measurements, the chemical and mechanical stability range of LSFT were determined and defect structure was established. The studies on the fracture toughness of the LSFT and dual phase membranes exposed to air and N{sub 2} at 1000 C was done and the XRD and SEM analysis of the specimens were carried out to understand the structural and microstructural changes. The membranes that are exposed to high temperatures at an inert and a reactive atmosphere undergo many structural and chemical changes which affect the mechanical properties. A complete transformation of fracture behavior was observed in the N{sub 2} treated LSFT samples. Further results to investigate the origin of the slow kinetics on reduction of ferrites have been obtained. The slow kinetics appear to be related to a non-equilibrium reduction pathway that initially results in the formation of iron particles. At long times, equilibrium can be reestablished with recovery of the perovskite phase. Recent results on transient kinetic data are presented. The 2-D modeling of oxygen movement has been undertaken in order to fit isotope data. The model is used to study ''frozen'' profiles in patterned or composite membranes.

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

2005-02-01T23:59:59.000Z

29

Oxygen Transport Ceramic Membranes  

SciTech Connect (OSTI)

The present quarterly report describes some of the investigations on the structural properties of dense OTM bars provided by Praxair and studies on newer composition of Ti doped Ti-substituted perovskites, La{sub 0.7}Sr{sub 0.3}Mn{sub 1-x}Ti{sub x}O{sub 3}, with 0 {le} x {le} 0.20, were investigated by neutron diffraction, magnetization, electric resistivity, and magnetoresistance (MR) measurements. All samples show a rhombohedral structure (space group R3C) from 10 K to room temperature. At room temperature, the cell parameters a, c and the unit cell volume increase with increasing Ti content. However, at 10 K, the cell parameter a has a maximum value for x = 0.10, and decreases for x > 0.10, while the unit cell volume remains nearly constant for x > 0.10. The average (Mn,Ti)-O bond length increases up to x = 0.15, and the (Mn,Ti)-O-(Mn,Ti) bond angle decreases with increasing Ti content to its minimum value at x = 0.15 at room temperature. Below the Curie temperature TC, the resistance exhibits metallic behavior for the x {le} 0.05 samples. A metal (semiconductor) to insulator transition is observed for the x {ge} 0.10 samples. A peak in resistivity appears below TC for all samples, and shifts to a lower temperature as x increases. The substitution of Mn by Ti decreases the 2p-3d hybridization between O and Mn ions, reduces the bandwidth W, and increases the electron-phonon coupling. Therefore, the TC shifts to a lower temperature and the resistivity increases with increasing Ti content. A field-induced shift of the resistivity maximum occurs at x {le} 0.10 compounds. The maximum MR effect is about 70% for La{sub 0.7}Sr{sub 0.3}Mn{sub 0.8}Ti{sub 0.2}O{sub 3}. The separation of TC and the resistivity maximum temperature T{sub {rho},max} enhances the MR effect in these compounds due to the weak coupling between the magnetic ordering and the resistivity as compared with La{sub 0.7}Sr{sub 0.3}MnO{sub 3}. The bulk densities of the membranes were determined using the Archimedes method. The bulk density was 5.029 and 5.57 g/cc for LSFT and dual phase membranes, respectively. The microstructure of the dual phase membrane was analyzed using SEM. It is evident from the micrograph that the microstructure is composed of dual phases. The dense circular regions are enclosed by the less dense, continuous phase which accommodates most of the pores. The pores are normally aggregated and found clustered along the dense regions where as the dense regions do not have pores. Upon closer observation of the micrograph it is revealed that the dense region has a clear circular cleavage or crack as their boundary. The circular cleavage clearly encompasses a dense region and which consists of no pore or any flaw that is visible. The size distribution of the dense, discontinuous regions is varying from 5 to 20 {micro}m with a D{sub 50} of 15 {micro}m. The grain size distribution was estimated from the micrographs using image analysis and a unimodal distribution of grains was observed with an average grain size of 1.99 {micro}m. The chemical compositions of the membranes were analyzed using EDS analysis and no other impurities were observed. The XRD analysis was carried out for the membranes and the phase purity was confirmed. The fracture toughness of LSFT membranes at room temperature has to be calculated using the Vickers indentation method. An electrochemical cell has been designed and built for measurements of the ionic conductivity by the use of blocking electrodes. Preliminary measurements on La{sub 0.2}Sr{sub 0.8}Fe{sub 0.55}Ti{sub 0.45}O{sub 3-{delta}} are reported. Modifications to the apparatus to improve the data quality have been completed. Electron microscopy studies of the origin of the slow kinetics on reduction of ferrites have been initiated. A series of isotope transients under air separation mode (small gradient) were completed on the membrane of LSCrF-2828 at 900 C. Low pO{sub 2} atmospheres based on with CO-CO{sub 2} mixtures have also been admitted to the delivery side of the LSCrF-2828 membrane to produce the gradient

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

2005-05-01T23:59:59.000Z

30

Oxygen Transport Ceramic Membranes  

SciTech Connect (OSTI)

Ti doping on La{sub 1-x}Sr{sub x}FeO{sub 3-{delta}} (LSF) tends to increase the oxygen equilibration kinetics of LSF in lower oxygen activity environment because of the high valence state of Ti. However, the addition of Ti decreases the total conductivity because the acceptor ([Sr{prime}{sub La}]) is compensated by the donor ([Ti{sub Fe}{sup {sm_bullet}}]) which decreases the carrier concentration. The properties of La{sub 0.2}Sr{sub 0.8}Fe{sub 1-x}Ti{sub x}O{sub 3-{delta}} (LSFT, x = 0.45) have been experimentally and theoretically investigated to elucidate (1) the dependence of oxygen occupancy and electrochemical properties on temperature and oxygen activity by thermogravimetric analysis (TGA) and (2) the electrical conductivity and carrier concentration by Seebeck coefficient and electrical measurements. In the present study, dual phase (La{sub 0.2}Sr{sub 0.8}Fe{sub 0.6}Ti{sub 0.4}O{sub 3-{delta}}/Ce{sub 0.9}Gd{sub 0.1}O{sub 2-{delta}}) membranes have been evaluated for structural properties such as hardness, fracture toughness and flexural strength. The effect of high temperature and slightly reducing atmosphere on the structural properties of the membranes was studied. The flexural strength of the membrane decreases upon exposure to slightly reducing conditions at 1000 C. The as-received and post-fractured membranes were characterized using XRD, SEM and TG-DTA to understand the fracture mechanisms. Changes in structural properties of the composite were sought to be correlated with the physiochemical features of the two-phases. We have reviewed the electrical conductivity data and stoichiometry data for La{sub 0.2}Sr{sub 0.8}Cr{sub 0.2}Fe{sub 0.8}O{sub 3-{delta}} some of which was reported previously. Electrical conductivity data for La{sub 0.2}Sr{sub 0.8}Cr{sub 0.2}Fe{sub 0.8}O{sub 3-{delta}} (LSCrF) were obtained in the temperature range, 752 {approx} 1055 C and in the pO{sub 2} range, 10{sup -18} {approx} 0.5 atm. The slope of the plot of log {sigma} vs. log pO{sub 2} is {approx} 1/5 in the p-type region, pO{sub 2} = 10{sup -5} {approx} 10{sup -1} atm. The pO{sub 2} at which the p-n transition is observed increases with increasing temperature. The activation energy for ionic conduction was estimated to be 0.86 eV from an Arrhenius plot of the minimum conductivity vs. reciprocal temperature. At temperatures below 940 C, a plateau in the conductivity isotherm suggests the presence of a two-phase region. Most likely, phase separation occurs to form a mixture of a perovskite phase and an oxygen vacancy ordered phase related to brownmillerite. Additional data for the oxygen non stoichiometry are presented.

S. Bandopadhyay; T. Nithyanantham

2006-12-31T23:59:59.000Z

31

Oxygen Transport Ceramic Membranes  

SciTech Connect (OSTI)

A non-agglomerated and nanocrystalline-sized powder was successfully produced using ethylene glycol nitrate methods. The LSFT powder prepared using this method exhibits well dispersed and nano-sized particles about 100-200 nm. The density of LSFT sintered at 1300 C was about 90% of the theoretical density at which is 100 C less than that of the previous LSFT which was sintered at 1400 C. The sample sintered at 1400 C exhibited the evidence of a liquid phase at the grain boundaries and 2nd phase formation which probably caused low mechanical stability. The electrical conductivity and Seebeck coefficient were measured as a function of temperature. The LSFT-CGO specimens were cut from the as sintered bars and used for the evaluation of Mechanical Properties after polishing. The effect of strain rate on the flexural strength of the LSFT-CGO test specimens was studied. Three strain rates 6, 60 and 600 {micro}m/ min were chosen for this study. It is observed from the results that with increasing cross head speed the membrane takes higher loads to fail. A reduction in the strength of the membrane was observed at 1000 C in N{sub 2}. Two different routes were investigated to synthesis GDC using either formate or carbonate precursors. The precursor and CGO particle morphologies were examined by scanning electron microscopy. The thermal decomposition behaviors of Ce(Gd)(HCOO){sub 3} and Ce(Gd)(CO{sub 3})(OH) were determined by thermogravimetric analysis (TGA) at a rate of 3 C/min in air. The X-ray powder diffraction patterns of the precursor and CGO were collected and nitrogen adsorption isotherms were measured. Conductivity measurements were made by AC impedance spectroscopy on sintered disks in air using platinum electrodes.

S. Bandopadhyay; T. Nithyanantham

2006-06-30T23:59:59.000Z

32

Membrane Transport Chloride Transport Across Vesicle and Cell  

E-Print Network [OSTI]

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 the formation of an ion pair.[4a­g] Anion transport by purely electroneutral systems is still quite rare.[4j

Smith, Bradley D.

33

Oxygen Transport Ceramic Membranes Quarterly Report  

E-Print Network [OSTI]

/Reaction rates in Ion 21 Transport Membranes using Isotope Tracer and Transient Kinetic Techniques CONCLUSIONS 30Oxygen Transport Ceramic Membranes Quarterly Report January 2003 ­ March 2003 Principal Authors on the thermodynamic properties of the membrane materials are continued to develop a complete model for the membrane

Eagar, Thomas W.

34

Oxygen Transport Ceramic Membranes  

SciTech Connect (OSTI)

The present quarterly report describes some of the investigations on the structural properties of dense OTM bars provided by Praxair and initial studies on newer composition of Ti doped LSF. Dense OTM bars provided by Praxair were loaded to fracture at varying stress rates. Studies were done at room temperature in air and at 1000 C in a specified environment to evaluate slow crack growth behavior. In addition, studies were also begun to obtain reliable estimates of fracture toughness and stable crack growth in specific environments. Newer composition of Ti doped LSF membranes were characterized by neutron diffraction analysis. Quench studies indicated an apparent correlation between the unit cell volume and oxygen occupancy. The studies however, indicated an anomaly of increasing Fe/Ti ratio with change in heat treatment. Ti doped LSF was also characterized for stoichiometry as a function of temp and pO{sub 2}. The non stoichiometry parameter {delta} was observed to increase almost linearly on lowering pO{sub 2} until a ideal stoichiometric composition of {delta} = 0.175 was approached.

S. Bandopadhyay; N. Nagabhushana; X.-D Zhou; W.B. Yelon; H.U. Anderson; Alan Jacobson; C.A. Mims

2004-02-01T23:59:59.000Z

35

Controlling membrane protein folding using photoresponsive surfactant.  

E-Print Network [OSTI]

??Membrane proteins perform a number of roles in biological function. Membrane lipids can self assembly into numerous different phases in aqueous solution, including micelles, vesicles (more)

Chang, Chia Hao

2012-01-01T23:59:59.000Z

36

Catalyst containing oxygen transport membrane  

SciTech Connect (OSTI)

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.

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

2012-12-04T23:59:59.000Z

37

Ion transport membrane module and vessel system  

SciTech Connect (OSTI)

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.

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)

2012-02-14T23:59:59.000Z

38

Ion transport membrane module and vessel system  

DOE Patents [OSTI]

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.

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)

2008-02-26T23:59:59.000Z

39

Evidence for a dynamic and transient pathway through the TAT protein transport machinery  

E-Print Network [OSTI]

, University of Florida, Gainesville FL, USA Tat systems transport completely folded proteins across ion Categories: membranes & transport; proteins Keywords: chloroplasts; protein transport; thylakoid; trans transport machinery in thylakoids (called cpTat) consists of three membrane proteins; Tha4, Hcf106, and cp

40

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

DOE Patents [OSTI]

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.

Laible, Philip D; Hanson, Deborah K

2013-06-04T23:59:59.000Z

Note: This page contains sample records for the topic "membrane transport proteins" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


41

Liners for ion transport membrane systems  

SciTech Connect (OSTI)

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.

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

2010-08-10T23:59:59.000Z

42

Class II virus membrane fusion proteins  

SciTech Connect (OSTI)

Enveloped animal viruses fuse their membrane with a host cell membrane, thus delivering the virus genetic material into the cytoplasm and initiating infection. This critical membrane fusion reaction is mediated by a virus transmembrane protein known as the fusion protein, which inserts its hydrophobic fusion peptide into the cell membrane and refolds to drive the fusion reaction. This review describes recent advances in our understanding of the structure and function of the class II fusion proteins of the alphaviruses and flaviviruses. Inhibition of the fusion protein refolding reaction confirms its importance in fusion and suggests new antiviral strategies for these medically important viruses.

Kielian, Margaret [Department of Cell Biology, Albert Einstein College of Medicine, 1300 Morris Park Ave., Bronx, NY 10461 (United States)]. E-mail: kielian@aecom.yu.edu

2006-01-05T23:59:59.000Z

43

Characterization of a plasma membrane zinc transporter in rat brain  

E-Print Network [OSTI]

Ireland Ltd. Keywords: Ion transport; Membrane vesicles; Excitotoxicity; Zinc homeostasis; TransitionCharacterization of a plasma membrane zinc transporter in rat brain Robert A. Colvin* Department transport in the brain. This report provides convincing evidence of a zinc transporter in plasma membrane

44

RESEARCH ARTICLE Open Access Comparison of membrane proteins of Mycobacterium  

E-Print Network [OSTI]

Background: The potential causes for variation in virulence between distinct M. tuberculosis strains are still not fully known. However, differences in protein expression are probably an important factor. In this study we used a labelfree quantitative proteomic approach to estimate differences in protein abundance between two closely related M. tuberculosis strains; the virulent H37Rv strain and its attenuated counterpart H37Ra. Results: We were able to identify more than 1700 proteins from both strains. As expected, the majority of the identified proteins had similar relative abundance in the two strains. However, 29 membrane-associated proteins were observed with a 5 or more fold difference in their relative abundance in one strain compared to the other. Of note, 19 membrane- and lipo-proteins had higher abundance in H37Rv, while another 10 proteins had a higher abundance in H37Ra. Interestingly, the possible protein-export membrane protein SecF (Rv2586c), and three ABCtransporter proteins (Rv0933, Rv1273c and Rv1819c) were among the more abundant proteins in M. tuberculosis H37Rv. Conclusion: Our data suggests that the bacterial secretion system and the transmembrane transport system may be important determinants of the ability of distinct M. tuberculosis strains to cause disease. Background

Tuberculosis Hrv; Hra Strains; Hiwa Mlen; Gustavo A De Souza; Sharad Pathak; Tina Sftel; Harald G Wiker

45

Composition variation and underdamped mechanics near membrane proteins and coats  

E-Print Network [OSTI]

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.

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

2015-02-14T23:59:59.000Z

46

Ion Transport Through Cell Membrane Channels Jan Gomulkiewicz1  

E-Print Network [OSTI]

1 Ion Transport Through Cell Membrane Channels Jan Gomulkiewicz1 , Jacek Mikisz2 , and Stanislaw various models of ion transport through cell membrane channels. Recent experimental data shows that sizes for the life of a cell. In particular, a fundamental phenomenon is a transport of ions through cell membranes

Miekisz, Jacek

47

Membrane Proteins DOI: 10.1002/anie.201107343  

E-Print Network [OSTI]

is hampered by a lack of high-throughput methods for their study. Membrane proteins remain such challengingMembrane Proteins DOI: 10.1002/anie.201107343 Quantification of Membrane Protein Inhibition. Wallace* Despite the importance of membrane proteins as drug targets the discovery of new compounds

Wallace, Mark

48

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:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear Security Administration the1 - SeptemberMicroneedles for4-16HamadaBaO/Al2O3Protecting LabProteinProteinProtein

49

Cellular mechanisms of membrane protein folding William R Skach  

E-Print Network [OSTI]

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

Cai, Long

50

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:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear Security Administration the1 - SeptemberMicroneedles for4-16HamadaBaO/Al2O3Protecting LabProteinProtein Flips

51

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:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear Security Administration the1 - SeptemberMicroneedles for4-16HamadaBaO/Al2O3Protecting LabProteinProtein

52

Artificial oxygen transport protein  

DOE Patents [OSTI]

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.

Dutton, P. Leslie

2014-09-30T23:59:59.000Z

53

Quantitative analysis of cell surface membrane proteins using...  

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

the quantification of membrane proteome changes, enriched membrane protein samples from wild-type and mutant cells (generated from deletion of a type II secretion protein, GspD)...

54

Sorting of inner nuclear membrane-directed proteins at the endoplasmic reticulum membrane  

E-Print Network [OSTI]

The current "diffusion-retention" model for protein trafficking to the inner nuclear membrane (INM) proposes that INM proteins diffuse laterally from the membrane of the endoplasmic reticulum into the INM and are then retained in the INM by binding...

Saksena, Suraj

2006-04-12T23:59:59.000Z

55

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

E-Print Network [OSTI]

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.

Urka Jeler?i?; Nir S. Gov

2014-09-26T23:59:59.000Z

56

Fabrication of catalyzed ion transport membrane systems  

DOE Patents [OSTI]

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).

Carolan, Michael Francis; Kibby, Charles Leonard

2013-06-04T23:59:59.000Z

57

Measurement of Water Transport Properties Through Membrane-Electrode Assemblies  

E-Print Network [OSTI]

a similar apparatus with Pd/H electrodes and obtained EOD equal to 2.5 and 0.9 at 30C for a fully hydratedMeasurement of Water Transport Properties Through Membrane-Electrode Assemblies I. Membranes of Ag/AgCl electrodes to derive a constant current across a membrane in contact on both sides with a 0

58

Self-assembled lipid and membrane protein polyhedral nanoparticles  

E-Print Network [OSTI]

Self-assembled lipid and membrane protein polyhedral nanoparticles Tamara Bastaa,1 , Hsin-Jui Wub,1 for review January 28, 2012) We demonstrate that membrane proteins and phospholipids can self-assemble for the self-assembly of lipids and membrane proteins into closed polyhedral structures that can potentially

Stowell, Michael

59

Membranes for nanometer-scale mass fast transport  

DOE Patents [OSTI]

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.

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

2011-10-18T23:59:59.000Z

60

Membrane porters of ATP-binding cassette transport systems are polyphyletic  

E-Print Network [OSTI]

in Membrane porters of ATP-binding cassette transportin Membrane porters of ATP-binding cassette transportin Membrane porters of ATP-binding cassette transport

Wang, Bin

2010-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "membrane transport proteins" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


61

Microfluidic Generation of Lipidic Mesophases for Membrane Protein Crystallization  

E-Print Network [OSTI]

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

Kenis, Paul J. A.

62

Feed gas contaminant removal in ion transport membrane systems  

SciTech Connect (OSTI)

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.

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

2012-04-03T23:59:59.000Z

63

Interfacial Water-Transport Effects in Proton-Exchange Membranes  

SciTech Connect (OSTI)

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.

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

2009-11-19T23:59:59.000Z

64

MICROFLUIDIC DEVICE FOR SUPER-FAST EVALUATION OF MEMBRANE PROTEIN  

E-Print Network [OSTI]

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

Stowell, Michael

65

Development of active-transport membrane devices  

SciTech Connect (OSTI)

This report introduces the concept of Air Products` AT membranes for the separation of NH{sub 3} and CO{sub 2} from process gas streams and presents results from the first year fabrication concept development studies.

Laciak, D.V.

1994-07-01T23:59:59.000Z

66

Nanostructured Silicon Membranes for Control of Molecular Transport  

SciTech Connect (OSTI)

A membrane that allows selective transport of molecular species requires precise engineering on the nanoscale. Membrane permeability can be tuned by controlling the physical structure of the pores. Here, a combination of electron-beam and optical lithography, along with cryogenic deep reactive ion etching, has been used to fabricate silicon membranes that are physically robust, have uniform pore-sizes, and are directly integrated into a microfluidic network. Additional reductions in pore size were achieved using plasma enhanced chemical vapor deposition of silicon dioxide to coat membrane surfaces. Cross sectioning of the membranes using focused ion beam milling was used to determine the physical shape of the membrane pores before and after coating.

Srijanto, Bernadeta R [ORNL] [ORNL; Retterer, Scott T [ORNL] [ORNL; Fowlkes, Jason Davidson [ORNL] [ORNL; Doktycz, Mitchel John [ORNL] [ORNL

2010-01-01T23:59:59.000Z

67

Ultrafiltration membrane performance when processing oilseed protein extracts  

E-Print Network [OSTI]

feed pressure and 654C feed temperature. The UCARSEP ABR membrane was manufactured by Union Carbide Inc. , Tarrytown, NY. The basic membrane consists of a 0. 24-inch ID tube, 48-inches long. The system, as tested consisted of two tubes connected... or peanut protein isolation by UF and RO membranes 2. Simplified flow diagram for cottonseed protein isolation by UF and RO membranes 10 3. Effect of temperature on flux of the UCARSEP membrane when processing SP extract at 1. 8% solids 19 4. Effect...

Hensley, Donald Wayne

1979-01-01T23:59:59.000Z

68

Vesicle-associated membrane protein 2 mediates trafficking of {alpha}5{beta}1 integrin to the plasma membrane  

SciTech Connect (OSTI)

Integrins are major receptors for cell adhesion to the extracellular matrix (ECM). As transmembrane proteins, the levels of integrins at the plasma membrane or the cell surface are ultimately determined by the balance between two vesicle trafficking events: endocytosis of integrins at the plasma membrane and exocytosis of the vesicles that transport integrins. Here, we report that vesicle-associated membrane protein 2 (VAMP2), a SNARE protein that mediates vesicle fusion with the plasma membrane, is involved in the trafficking of {alpha}5{beta}1 integrin. VAMP2 was present on vesicles containing endocytosed {beta}1 integrin. Small interfering RNA (siRNA) silencing of VAMP2 markedly reduced cell surface {alpha}5{beta}1 and inhibited cell adhesion and chemotactic migration to fibronectin, the ECM ligand of {alpha}5{beta}1, without altering cell surface expression of {alpha}2{beta}1 integrin or {alpha}3{beta}1 integrin. By contrast, silencing of VAMP8, another SNARE protein, had no effect on cell surface expression of the integrins or cell adhesion to fibronectin. In addition, VAMP2-mediated trafficking is involved in cell adhesion to collagen but not to laminin. Consistent with disruption of integrin functions in cell proliferation and survival, VAMP2 silencing diminished proliferation and triggered apoptosis. Collectively, these data indicate that VAMP2 mediates the trafficking of {alpha}5{beta}1 integrin to the plasma membrane and VAMP2-dependent integrin trafficking is critical in cell adhesion, migration and survival.

Hasan, Nazarul [Department of Biochemistry and Molecular Biology, University of Louisville School of Medicine, 319 Abraham Flexner Way, Room 515, Louisville, KY 40202 (United States)] [Department of Biochemistry and Molecular Biology, University of Louisville School of Medicine, 319 Abraham Flexner Way, Room 515, Louisville, KY 40202 (United States); Hu, Chuan, E-mail: chuan.hu@louisville.edu [Department of Biochemistry and Molecular Biology, University of Louisville School of Medicine, 319 Abraham Flexner Way, Room 515, Louisville, KY 40202 (United States)] [Department of Biochemistry and Molecular Biology, University of Louisville School of Medicine, 319 Abraham Flexner Way, Room 515, Louisville, KY 40202 (United States)

2010-01-01T23:59:59.000Z

69

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

E-Print Network [OSTI]

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

Neary, Tiffany Jonean

2008-01-01T23:59:59.000Z

70

Alkylsulfonates as Probes of Uncoupling Protein Transport ION PAIR TRANSPORT DEMONSTRATES THAT DIRECT H TRANSLOCATION BY UCP1 IS NOT NECESSARY  

E-Print Network [OSTI]

Alkylsulfonates as Probes of Uncoupling Protein Transport Mechanism ION PAIR TRANSPORT DEMONSTRATES of Membrane Transport Biophysics, Institute of Physiology, Academy of Sciences, Prague 14220, Czech Republic is transported with the neutral ion pair, the sulfonate is able to deliver protons across the bilayer, behaving

Garlid, Keith

71

Hydrogen transport membranes for dehydrogenation reactions  

DOE Patents [OSTI]

A method of converting C.sub.2 and/or higher alkanes to olefins by contacting a feedstock containing C.sub.2 and/or higher alkanes with a first surface of a metal composite membrane of a sintered homogenous mixture of an Al oxide or stabilized or partially stabilized Zr oxide ceramic powder and a metal powder of one or more of Pd, Nb, V, Zr, Ta and/or alloys or mixtures thereof. The alkanes dehydrogenate to olefins by contact with the first surface with substantially only atomic hydrogen from the dehydrogenation of the alkanes passing through the metal composite membrane. Apparatus for effecting the conversion and separation is also disclosed.

Balachandran; Uthamalingam (Hinsdale, IL)

2008-02-12T23:59:59.000Z

72

Controlling membrane protein folding with light illumination and catanionic surfactant systems.  

E-Print Network [OSTI]

??Membrane proteins are of significant importance, performing a variety of biological functions including pumps, channels, and receptors. Thus, membrane proteins represent attractive candidates as drug (more)

Zhang, Jing

2008-01-01T23:59:59.000Z

73

E-Print Network 3.0 - abnormal membrane proteins Sample Search...  

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

membrane and secreted proteins begin their journey to the surface. Only... of protein folding in the ER coupled across the ER membrane to cytosolic effector domains that...

74

Electrochemical control of ion transport through a mesoporous carbon membrane  

SciTech Connect (OSTI)

The transport of fluids through nanometer scale channels typically on the order of 1 -100 nm often exhibit unique properties compared to the bulk fluid. These phenomena occur because the channel dimensions and molecular size become comparable to the range of several important forces including electrostatic and van der Waals forces. Small changes in properties such as the electric double layer or surface charge can significantly affect molecular transport through the channels. Based on these emerging properties, a variety of nanofluidic devices such as nanofluidic transistors, nanofluidic diodes or lab-on-a-chip devices have been developed3-7 with a diverse range of applications including water purification, biomolecular sensing, DNA separation, and rectified ion transport. Nanofluidic devices are typically fabricated using expensive lithography techniques or sacrificial templates. Here we report a carbon-based, three-dimensional nanofluidic transport membrane that enables gated, or on/off, control of the transport of organic molecular species and metal ions using an applied electrical potential. In the absence of an applied potential, both cationic and anionic molecules freely diffuse across the membrane via a concentration gradient. However, when an electrochemical potential is applied, the transport of ions through the membrane is inhibited.

Surwade, Sumedh P [ORNL] [ORNL; Chai, Songhai [ORNL] [ORNL; Choi, Jai-Pil [ORNL] [ORNL; Wang, Xiqing [ORNL] [ORNL; Lee, Jeseung [ORNL] [ORNL; Vlassiouk, Ivan V [ORNL] [ORNL; Mahurin, Shannon Mark [ORNL] [ORNL; Dai, Sheng [ORNL] [ORNL

2014-01-01T23:59:59.000Z

75

Feed gas contaminant control in ion transport membrane systems  

DOE Patents [OSTI]

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.

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

2009-07-07T23:59:59.000Z

76

Multicomponent Transport through Realistic Zeolite Membranes: Characterization & Transport in Nanoporous Networks  

SciTech Connect (OSTI)

These research studies focused on the characterization and transport for porous solids which comprise both microporosity and mesoporosity. Such materials represent membranes made from zeolites as well as for many new nanoporous solids. Several analytical sorption techniques were developed and evaluated by which these multi-dimensional porous solids could be quantitatively characterized. Notably an approach by which intact membranes could be studied was developed and applied to plate-like and tubular supported zeolitic membranes. Transport processes were studied experimentally and theoretically based on the characterization studies.

William C. Conner

2007-08-02T23:59:59.000Z

77

Investigating cotranslational protein integration into the endoplasmic reticulum membrane  

E-Print Network [OSTI]

During co-translational integration, the transmembrane (TM) sequence of a nascent membrane protein moves laterally into the ER lipid bilayer upon reaching the translocon. Our lab has previously shown that this movement is a multistep process...

McCormick, Peter Joseph

2005-02-17T23:59:59.000Z

78

ADVANCED HYDROGEN TRANSPORT MEMBRANES FOR VISION 21 FOSSIL FUEL PLANTS  

SciTech Connect (OSTI)

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.

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

2001-07-30T23:59:59.000Z

79

ADVANCED HYDROGEN TRANSPORT MEMBRANES FOR VISION 21 FOSSIL FUEL PLANTS  

SciTech Connect (OSTI)

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.

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

2001-10-30T23:59:59.000Z

80

IFITM Proteins Restrict Viral Membrane Hemifusion  

E-Print Network [OSTI]

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

2013-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "membrane transport proteins" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


81

Ballistic electron transport in structured suspended semiconductor membranes  

SciTech Connect (OSTI)

We study ballistic electron transport in freely suspended AlAs/GaAs microstructures containing a high mobility two-dimensional electron gas with square lattice of antidots. We found that the magnetoresistance of the samples demonstrates commensurability oscillations both for the case of non-suspended and suspended devices. The temperature dependence of the commensurability oscillations is similar for both cases. However, the critical dc current, that suppresses these oscillations, in suspended samples is three times lower than in non-suspended ones. The observed phenomenon can be explained by peculiarities of the heat transport in membranes.

Pogosov, A. G.; Budantsev, M. V.; Zhdanov, E. Yu.; Pokhabov, D. A. [Institute of Semiconductor Physics SB RAS, Novosibirsk, Russia and Novosibirsk State University, Novosibirsk (Russian Federation)

2013-12-04T23:59:59.000Z

82

Detergent selection for enhanced extraction of membrane proteins Buenafe T. Arachea 1  

E-Print Network [OSTI]

: Membrane proteins Extraction efficiency Detergents Surfactants Mass spectrometry a b s t r a c t Generating. Introduction Membrane proteins are the last major frontier for protein struc- tural investigation

Viola, Ronald

83

Predicting Three-Dimensional Structures of Transmembrane Domains of -Barrel Membrane Proteins  

E-Print Network [OSTI]

for -barrel membrane proteins, and the lack of an overall quantitative theoretical understandingPredicting Three-Dimensional Structures of Transmembrane Domains of -Barrel Membrane Proteins Information ABSTRACT: -Barrel membrane proteins are found in the outer membrane of gram-negative bacteria

Dai, Yang

84

ADVANCED HYDROGEN TRANSPORT MEMBRANES FOR VISION 21 FOSSIL FUEL PLANTS  

SciTech Connect (OSTI)

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.

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

2002-07-30T23:59:59.000Z

85

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

SciTech Connect (OSTI)

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

MURAD, SOHAIL [University of Illinois at Chicago] [University of Illinois at Chicago; JAMESON, CYNTHIA J [University of Illinois at Chicago] [University of Illinois at Chicago

2013-10-22T23:59:59.000Z

86

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

E-Print Network [OSTI]

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

Fayer, Michael D.

87

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

E-Print Network [OSTI]

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

White, Stephen

88

Transport of Alkali Halides through a Liquid Organic Membrane Containing a Ditopic Salt-Binding Receptor  

E-Print Network [OSTI]

in the solid state as contact ion pairs. Transport experiments, using a supported liquid membrane and high saltTransport of Alkali Halides through a Liquid Organic Membrane Containing a Ditopic Salt and anion receptors. All transport systems exhibit the same qualitative order of ion selectivity; that is

Smith, Bradley D.

89

pH dependence and compartmentalization of zinc transported across plasma membrane of rat cortical neurons  

E-Print Network [OSTI]

pH dependence and compartmentalization of zinc transported across plasma membrane of rat corticalH dependence and compartmental- ization of zinc transported across plasma membrane of rat cortical neurons. Am; ion transport; transition elements; primary culture IT IS KNOWN THAT Zn2 can enter neurons by two

90

Ionic transport in nanocapillary membrane systems Vikhram V. Swaminathan Larry R. Gibson II  

E-Print Network [OSTI]

. Keywords Membranes Á Nanostructures Á Nanofluidics Á Microfluidics Á Ion transport Á Electrokinetics Á lREVIEW Ionic transport in nanocapillary membrane systems Vikhram V. Swaminathan · Larry R. Gibson / Accepted: 23 May 2012 ? Springer Science+Business Media B.V. 2012 Abstract Species transport

91

Polymer electrolyte membranes from fluorinated polyisoprene-block-sulfonated polystyrene: Membrane structure and transport properties  

SciTech Connect (OSTI)

With a view to optimizing morphology and ultimately properties, membranes have been cast from relatively inexpensive block copolymer ionomers of fluorinated polyisoprene-block-sulfonated polystyrene (FISS) with various sulfonation levels, in both the acid form and the cesium neutralized form. The morphology of these membranes was characterized by transmission electron microscopy and ultra-small angle X-ray scattering, as well as water uptake, proton conductivity and methanol permeability within the temperature range from 20 to 60 C. Random phase separated morphologies were obtained for all samples except the cesium sample with 50 mol% sulfonation. The transport properties increased with increasing degree of sulfonation and temperature for all samples. The acid form samples absorbed more water than the cesium samples with a maximum swelling of 595% recorded at 60 C for the acid sample having 50 mol% sulfonation. Methanol permeability for the latter sample was more than an order of magnitude less than for Nafion 112 but so was the proton conductivity within the plane of the membrane at 20 C. Across the plane of the membrane this sample had half the conductivity of Nafion 112 at 60 C.

Sodeye, Akinbode [Department of Polymer Science and Engineering, University of Massachusetts; Huang, Tianzi [University of Tennessee, Knoxville (UTK); Gido, Samuel [University of Massachusetts, Amherst; Mays, Jimmy [ORNL

2011-01-01T23:59:59.000Z

92

E-Print Network 3.0 - aeruginosa membrane transport Sample Search...  

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

U. The membrane-bound electron transport system of Methanosarcina species. J. Bioenerg. Biomembr... of methanophenazine and function of phenazines in ... Source: Dietrich,...

93

E-Print Network 3.0 - active transport membrane Sample Search...  

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

84 CURRICULUM VITAE JOHN PETER PALMERI Summary: Membrane Transport Theory Dual American-French Nationality PROFESSIONAL ADDRESS Laboratoire de Physique... of Montpellier II,...

94

Charge Transport through a Novel Zeolite Y Membrane by a Self-Exchange Process Hyunjung Lee and Prabir K. Dutta*  

E-Print Network [OSTI]

Charge Transport through a Novel Zeolite Y Membrane by a Self-Exchange Process Hyunjung Lee-photoresist-coated membranes were found. Accessibility of the intrazeolitic volume was examined by ion exchange and for optimally illuminated membranes was comparable to uncoated membranes. Charge transport through the membrane

Dutta, Prabir K.

95

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

E-Print Network [OSTI]

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

Sanchez, Katheryn Marie

2010-01-01T23:59:59.000Z

96

Structural Origins of Nitroxide Side Chain Dynamics on Membrane Protein [alpha]-Helical Sites  

SciTech Connect (OSTI)

Understanding the structure and dynamics of membrane proteins in their native, hydrophobic environment is important to understanding how these proteins function. EPR spectroscopy in combination with site-directed spin labeling (SDSL) can measure dynamics and structure of membrane proteins in their native lipid environment; however, until now the dynamics measured have been qualitative due to limited knowledge of the nitroxide spin label's intramolecular motion in the hydrophobic environment. Although several studies have elucidated the structural origins of EPR line shapes of water-soluble proteins, EPR spectra of nitroxide spin-labeled proteins in detergents or lipids have characteristic differences from their water-soluble counterparts, suggesting significant differences in the underlying molecular motion of the spin label between the two environments. To elucidate these differences, membrane-exposed {alpha}-helical sites of the leucine transporter, LeuT, from Aquifex aeolicus, were investigated using X-ray crystallography, mutational analysis, nitroxide side chain derivatives, and spectral simulations in order to obtain a motional model of the nitroxide. For each crystal structure, the nitroxide ring of a disulfide-linked spin label side chain (R1) is resolved and makes contacts with hydrophobic residues on the protein surface. The spin label at site I204 on LeuT makes a nontraditional hydrogen bond with the ortho-hydrogen on its nearest neighbor F208, whereas the spin label at site F177 makes multiple van der Waals contacts with a hydrophobic pocket formed with an adjacent helix. These results coupled with the spectral effect of mutating the i {+-} 3, 4 residues suggest that the spin label has a greater affinity for its local protein environment in the low dielectric than on a water-soluble protein surface. The simulations of the EPR spectra presented here suggest the spin label oscillates about the terminal bond nearest the ring while maintaining weak contact with the protein surface. Combined, the results provide a starting point for determining a motional model for R1 on membrane proteins, allowing quantification of nitroxide dynamics in the aliphatic environment of detergent and lipids. In addition, initial contributions to a rotamer library of R1 on membrane proteins are provided, which will assist in reliably modeling the R1 conformational space for pulsed dipolar EPR and NMR paramagnetic relaxation enhancement distance determination.

Kroncke, Brett M.; Horanyi, Peter S.; Columbus, Linda (UV)

2010-12-07T23:59:59.000Z

97

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

SciTech Connect (OSTI)

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.

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

2009-09-15T23:59:59.000Z

98

Assembly and Repair of Membrane-Bound Electron Transport Complexes similar to NifS than is Slr0387, but shows strong  

E-Print Network [OSTI]

Assembly and Repair of Membrane-Bound Electron Transport Complexes similar to NifS than is Slr0387 in the maturation of FeS proteins. We found that under some conditions the Synechocystis NifU-like protein can oxidation of the cysteine side chains at NifU. The same reaction might have occurred in lysed chloroplasts

99

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

E-Print Network [OSTI]

and topological transformations of membrane are crucial steps in numerous transport and signaling processes of cells, includ- ing cell migration, membrane trafficking, and ion conduc- tance 1­3 . There are various sorting complex required for transport III ESCRT III in- duced membrane budding or protrusion 5

Lu, Benzhuo

100

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

E-Print Network [OSTI]

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.

Nikhil Walani; Jennifer Torres; Ashutosh Agrawal

2015-02-14T23:59:59.000Z

Note: This page contains sample records for the topic "membrane transport proteins" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


101

ATP-binding cassette-like transporters are involved in the transport of lignin precursors across plasma and vacuolar membranes  

SciTech Connect (OSTI)

Lignin is a complex biopolymer derived primarily from the condensation of three monomeric precursors, the monolignols. The synthesis of monolignols occurs in the cytoplasm. To reach the cell wall where they are oxidized and polymerized, they must be transported across the cell membrane. However, the molecular mechanisms underlying the transport process are unclear. There are conflicting views about whether the transport of these precursors occurs by passive diffusion or is an energized active process; further, we know little about what chemical forms are required. Using isolated plasma and vacuolar membrane vesicles prepared from Arabidopsis, together with applying different transporter inhibitors in the assays, we examined the uptake of monolignols and their derivatives by these native membrane vesicles. We demonstrate that the transport of lignin precursors across plasmalemma and their sequestration into vacuoles are ATP-dependent primary-transport processes, involving ATP-binding cassette-like transporters. Moreover, we show that both plasma and vacuolar membrane vesicles selectively transport different forms of lignin precursors. In the presence of ATP, the inverted plasma membrane vesicles preferentially take up monolignol aglycones, whereas the vacuolar vesicles are more specific for glucoconjugates, suggesting that the different ATP-binding cassette-like transporters recognize different chemical forms in conveying them to distinct sites, and that glucosylation of monolignols is necessary for their vacuolar storage but not required for direct transport into the cell wall in Arabidopsis.

Miao, Y.C.; Liu, C.

2010-12-28T23:59:59.000Z

102

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

E-Print Network [OSTI]

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 with reaction kinetics and membrane dynamics. We use the Monte Carlo scheme to gain deeper insight to the experimentally observed radial growth of micron sized adhesion domains, and connect the effective rate with which the domain is growing to the underlying microscopic events. We thus demonstrate that our technique yields detailed information about protein transport and complexation in membranes, which is a fundamental step toward understanding even more complex membrane interactions in the cellular context.

Timo Bihr; Udo Seifert; Ana-Suncana Smith

2015-03-05T23:59:59.000Z

103

RAPID COMMUNICATION An Integral Membrane Green Fluorescent Protein Marker, Us9-GFP,  

E-Print Network [OSTI]

RAPID COMMUNICATION An Integral Membrane Green Fluorescent Protein Marker, Us9-GFP described GFP-spectrin, a membrane- localized derivative of the green fluorescent protein that can proteins employed in this assay. © 1999 Academic Press Key Words: green fluorescent protein; cell cycle

104

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

DOE Patents [OSTI]

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.

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

2014-01-07T23:59:59.000Z

105

Red Fluorescent Protein pH Biosensor to Detect Concentrative Nucleoside Transport*S  

E-Print Network [OSTI]

Red Fluorescent Protein pH Biosensor to Detect Concentrative Nucleoside Transport*S Received concentrative nucleoside transporter, hCNT3, medi- ates Na /nucleoside and H /nucleoside co-transport. We describe a new approach to monitor H /uridine co-transport in cultured mammalian cells, using a p

Campbell, Robert E.

106

Interfacial Water-Transport Effects in Proton-Exchange Membranes  

E-Print Network [OSTI]

MaterialsModelinginPemFuelCells,A CombinationModelIonomerMembranesforPem?FuelCells,"ElectrochimicaActa,

Kienitz, Brian

2010-01-01T23:59:59.000Z

107

Diffusion and selective transport of alkali cations on cation-exchange membrane  

SciTech Connect (OSTI)

The diffusion coefficients and selective transport for alkali metal cations through a charged polysulfonated ICE-450 ion-exchange membrane were measured as a function of pH at 25{degrees}C. The permeability and diffusion coefficients were found to increase in the sequence Cs{sup +} {ge} K{sup +} {ge} Na{sup +} {ge} Li{sup +}. The relationship between the permeability and the diffusion coefficients, and the hydrated radii of cations in the membrane were shown. This sequence was also explained by considering the hydration of ions in the membrane. The selectivity transport of K-Na and K-Li binary systems at various pH gradients through the membrane were also investigated under various conditions. In the selective transport of metal ions, the selectivity depended on both the hydrated ionic size and the interaction between the fixed groups in the membrane and the metal ions.

Ersoez, M. [Selcuk Univ., Konya (Turkey)

1995-11-01T23:59:59.000Z

108

The Structure of a Cyanobacterial Bicarbonate Transport Protein...  

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

Cyanobacterial Bicarbonate Transport Protein, CmpA. Abstract: Cyanobacteria, blue-green algae, are the most abundant autotrophs in aquatic environments and form the base of the...

109

Facilitated transport of sodium or potassium chloride across vesicle membranes using a ditopic salt-binding macrobicycle  

E-Print Network [OSTI]

Facilitated transport of sodium or potassium chloride across vesicle membranes using a ditopic salt or potassium chloride as a contact ion-pair, is shown to effect- ively transport either salt across vesicle membranes. Sig- nificant transport is observed even when the transporter : phospholipid ratio is as low as 1

Smith, Bradley D.

110

Numerical simulations of ion transport membrane oxy-fuel reactors for CO? capture applications  

E-Print Network [OSTI]

Numerical simulations were performed to investigate the key features of oxygen permeation and hydrocarbon conversion in ion transport membrane (ITM) reactors. ITM reactors have been suggested as a novel technology to enable ...

Hong, Jongsup

2013-01-01T23:59:59.000Z

111

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

E-Print Network [OSTI]

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 ...

Apo, Daniel Jolomi

2012-01-01T23:59:59.000Z

112

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

E-Print Network [OSTI]

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. ...

Mancini, Nicholas D. (Nicholas David)

2011-01-01T23:59:59.000Z

113

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

SciTech Connect (OSTI)

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.

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

2013-10-01T23:59:59.000Z

114

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

DOE Patents [OSTI]

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.

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

2010-02-09T23:59:59.000Z

115

Water transport in fuel cell membranes measured by laser interferometry  

E-Print Network [OSTI]

(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 ...

Kim, Jungik, 1973-

2009-01-01T23:59:59.000Z

116

ADVANCED HYDROGEN TRANSPORT MEMBRANES FOR VISION 21 FOSSIL FUEL PLANTS  

SciTech Connect (OSTI)

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.

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

2001-04-30T23:59:59.000Z

117

Transport Modeling of Membrane Extraction of Chlorinated Hydrocarbon from Water for Ion Mobility Spectrometry  

SciTech Connect (OSTI)

Membrane-extraction Ion Mobility Spectrometry (ME-IMS) is a feasible technique for the continuous monitoring of chlorinated hydrocarbons in water. This work studies theoretically the time-dependent characteristics of sampling and detection of trichloroethylene (TCE). The sampling is configured so that aqueous contaminants permeate through a hollow polydimethylsiloxane (PDMS) membrane and are carried away by a transport gas flowing through the membrane tube into IMS analyzer. The theoretical study is based on a two-dimensional transient fluid flow and mass transport model. The model describes the TCE mixing in the water, permeation through the membrane layer, and convective diffusion in the air flow inside membrane tube. The effect of various transport gas flow rates on temporal profiles of IMS signal intensity is investigated. The results show that fast time response and high transport yield can be achieved for ME-IMS by controlling the flow rate in the extraction membrane tube. These modeled time-response profiles are important for determining duty cycles of field-deployable sensors for monitoring chlorinated hydrocarbons in water.

Zhang, Wei [ORNL; Du, Yongzhai [ORNL; Feng, Zhili [ORNL; Xu, Jun [ORNL

2010-01-01T23:59:59.000Z

118

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

E-Print Network [OSTI]

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...

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

2013-01-01T23:59:59.000Z

119

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

E-Print Network [OSTI]

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. ...

Andreas, Loren B

2014-01-01T23:59:59.000Z

120

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]

, 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...

Williamson, Shawn T

2006-10-30T23:59:59.000Z

Note: This page contains sample records for the topic "membrane transport proteins" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


121

ADVANCED HYDROGEN TRANSPORT MEMBRANES FOR VISION 21 FOSSIL FUEL PLANTS  

SciTech Connect (OSTI)

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.

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

2003-01-30T23:59:59.000Z

122

Electric transport and oxygen permeation properties of lanthanum cobaltite membranes synthesized by different methods  

SciTech Connect (OSTI)

Dense perovskite-structured membranes with desired composition of La{sub 0.8}Sr{sub 0.2}Co{sub 0.6}Fe{sub 0.4}O{sub 3{minus}{delta}} (LSCF) were prepared from powders produced by four different methods. LSCF powders prepared by citrate, solid-state, and spray-pyrolysis methods had compositions close to the desired stoichiometry with a slight difference in cobalt concentration, whereas coprecipitated powders had a large strontium deficiency. The membrane composition was a determining factor that affected the electronic conductivity and therefore oxygen permeability. The membrane with a large strontium deficiency had much lower electronic conductivity and oxygen permeability (ionic conductivity) than the other three membranes with compositions close to the desired stoichiometry. The electronic conductivity of membranes prepared from citrate, solid-state, and spray-pyrolysis methods increases with the cobalt concentration of the membrane. For the three membranes with similar composition, the activation energy of oxygen flux decreases with increasing grain size. Oxygen pressure dependency of oxygen vacancy concentration is also influenced by the membrane microstructure and composition. LSCF membranes with same composition and similar microstructure should have similar electric and oxygen transport properties.

Qi, X.; Lin, Y.S.; Swartz, S.L.

2000-03-01T23:59:59.000Z

123

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

E-Print Network [OSTI]

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

Anderson, William David

2007-01-01T23:59:59.000Z

124

ADVANCED HYDROGEN TRANSPORT MEMBRANES FOR VISION 21 FOSSIL FUEL PLANTS  

SciTech Connect (OSTI)

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.

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

2002-04-30T23:59:59.000Z

125

The RCK Domain of the KtrAB K+ Transporter: Multiple Conformations  

E-Print Network [OSTI]

that is propagated to the membrane-bound protein, leading to ion transport (Jiang et al., 2002a; Roosild et al., 2002 transporter is a complex of the KtrB membrane protein and KtrA, an RCK do- main. RCK domains regulate eukaryotic and prokaryotic membrane proteins involved in K+ transport. Conflicting functional models have

Gruner, Sol M.

126

Transport Phenomena in Polymer Electrolyte Membranes I. Modeling Framework  

E-Print Network [OSTI]

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

Struchtrup, Henning

127

Control systems for membrane fusion in the ancestral eukaryote; evolution of tethering complexes and SM proteins  

E-Print Network [OSTI]

Abstract Background In membrane trafficking, the mechanisms ensuring vesicle fusion specificity remain to be fully elucidated. Early models proposed that specificity was encoded entirely by SNARE proteins; more recent models include contributions...

Koumandou, V Lila; Dacks, Joel B; Coulson, Richard M R; Field, Mark C

2007-02-23T23:59:59.000Z

128

Thorium ions transport across Tri-n-butyl phosphate-benzene based supported liquid membranes  

SciTech Connect (OSTI)

Transport of Th(IV) ions across tri-n-butyl phosphate (TBP) benzene based liquid membranes supported in microporous hydrophobic polypropylene film (MHPF) has been studied. Various parameters such as variation of nitric acid concentration in the feed, TBP concentration in the membrane, and temperature on the given metal ions transport have been investigated. The effects of nitric acid and TBP concentrations on the distribution coefficient were also studied, and the data obtained were used to determine the Th ions-TBP complex diffusion coefficient in the membrane. Permeability coefficients of Th(IV) ions were also determined as a function of the TBP and nitric acid concentrations. The optimal conditions for the transport of Th(IV) ions across the membrane are 6 mol{sm_bullet}dm{sup -3} HNO{sub 3} concentration, 2.188 mol {center_dot} dm{sup -3} TBP concentration, and 25{degrees}C. The stoichiometry of the chemical species involved in chemical reaction during the transport of Th(IV) ions has also been studied.

Rasul, G.; Chaudry, M.A. [Pakistan Institute of Nuclear Chemistry, Islamabad (Pakistan); Afzal, M. [Quaid-I-Azam Univ., Islamabad (Pakistan)

1995-12-01T23:59:59.000Z

129

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

E-Print Network [OSTI]

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

Giurgiutiu, Victor

130

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

DOE Patents [OSTI]

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.

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

2014-01-28T23:59:59.000Z

131

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

E-Print Network [OSTI]

not consume fossil fuels or pro- duce CO2 while producing highly pure hydrogen.1-10 Gaseous SO2 fedTransport Properties and Performance of Polymer Electrolyte Membranes for the Hybrid Sulfur and Biological Systems Department, Albuquerque, New Mexico 87123, USA c Department of Materials Science

Weidner, John W.

132

Correlating Humidity-Dependent Ionically Conductive Surface Area with Transport Phenomena in Proton-Exchange Membranes  

SciTech Connect (OSTI)

The objective of this effort was to correlate the local surface ionic conductance of a Nafion? 212 proton-exchange membrane with its bulk and interfacial transport properties as a function of water content. Both macroscopic and microscopic proton conductivities were investigated at different relative humidity levels, using electrochemical impedance spectroscopy and current-sensing atomic force microscopy (CSAFM). We were able to identify small ion-conducting domains that grew with humidity at the surface of the membrane. Numerical analysis of the surface ionic conductance images recorded at various relative humidity levels helped determine the fractional area of ion-conducting active sites. A simple square-root relationship between the fractional conducting area and observed interfacial mass-transport resistance was established. Furthermore, the relationship between the bulk ionic conductivity and surface ionic conductance pattern of the Nafion? membrane was examined.

He, Qinggang; Kusoglu, Ahmet; Lucas, Ivan T.; Clark, Kyle; Weber, Adam Z.; Kostecki, Robert

2011-08-01T23:59:59.000Z

133

Simulation of Membrane and Cell Culture Permeability and Transport  

E-Print Network [OSTI]

for neutral and ionized species partitioning into the membrane - only non-ionized species. Donor bulk (D) Acceptor bulk (A) D w h w D w h w k i c N k o c N ?? = ? = ?+?? ? + ? + = == i 1p pKa-pHpj 1r pH1)r(jpKa Ux N x p 1s a s j rs b s 10101 1 cc c..., Kansas, 2006 Pgp expression in human SI Mouly, S., Paine, M.F. PharmRes-20(10):1595-1598 (2003) GPEN, Kansas, 2006 Talinolol Non-linear Dose Dependence Talinolol Dose Dependence de Mey et al. J. Cardio. Pharmacol. 26(6):879 (1995) 0 200 400 600 800 1000...

Bolger, Michael

2006-10-26T23:59:59.000Z

134

Biomimetic materials for protein storage and transport  

DOE Patents [OSTI]

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.

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

2012-05-01T23:59:59.000Z

135

How the Membrane Protein AmtB Transports Ammonia  

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

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136

How the Membrane Protein AmtB Transports Ammonia  

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

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137

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:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth7-1D: Vegetation ProposedUsingFun withconfinement plasmas inPortalAllBPA addressesHow You Can SaveHowHowHow

138

How the Membrane Protein AmtB Transports Ammonia  

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

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139

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:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth7-1D: Vegetation ProposedUsingFun withconfinement plasmas inPortalAllBPA addressesHow You CanHow the

140

Structures for Three Membrane Transport Proteins Yield Functional Insights  

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

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Note: This page contains sample records for the topic "membrane transport proteins" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


141

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:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear Security AdministrationcontrollerNanocrystalline Gallium Oxide Thin Films. | EMSLStructures for Three

142

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:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear Security AdministrationcontrollerNanocrystalline Gallium Oxide Thin Films. | EMSLStructures for

143

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:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear Security AdministrationcontrollerNanocrystalline Gallium Oxide Thin Films. | EMSLStructures forStructures for

144

E-Print Network 3.0 - abc transporter mutants Sample Search Results  

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

THE ABC TRANSPORTER SUPERFAMILY Summary: -association of point mutants. 1. Introduction ATP-binding cassette (ABC) transporters are membrane-spanning proteins... -associated...

145

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

E-Print Network [OSTI]

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.

Volkov, Vadim

2012-01-01T23:59:59.000Z

146

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

E-Print Network [OSTI]

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.

Vadim Volkov

2012-12-18T23:59:59.000Z

147

An Outer Membrane Protein Undergoes Enthalpy-and Entropy-Driven Transitions  

E-Print Network [OSTI]

of Massachusetts Medical School, Worcester, Massachusetts 01605, United States § Syracuse Biomaterials Institute ABSTRACT: -Barrel membrane proteins often fluctuate among various open substates, yet the nature distinguishable, time-resolvable open substates. Native and loop-deletion OccK1 proteins showed substantial

Movileanu, Liviu

148

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

DOE Patents [OSTI]

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.

Liu, Wei

2014-05-06T23:59:59.000Z

149

Directed transport as a mechanism for protein folding in vivo  

E-Print Network [OSTI]

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.

Ernesto Gonzalez-Candela; Victor Romero-Rochin

2009-09-23T23:59:59.000Z

150

Proteomic Profiling of Nonenzymatically Glycated Proteins in Human Plasma and Erythrocyte Membrane  

SciTech Connect (OSTI)

Non-enzymatic glycation of peptides and proteins by D-glucose has important implications in the pathogenesis of diabetes mellitus, particularly in the development of diabetic complications. In this report, a thorough proteomic profiling of glycated proteins was attempted by using phenylboronate affinity chromatography to enrich glycated proteins and glycated, tryptic peptides from human plasma and erythrocyte membranes. Enriched peptides were subsequently analyzed by liquid chromatography coupled with electron transfer dissociation tandem mass spectrometry, and 76 and 31 proteins were confidently identified as glycated from human plasma and erythrocyte membrane, respectively. It was observed that most of the glycated proteins can be identified in samples from individuals with normal glucose tolerance, although samples from individuals with impaired glucose tolerance and type 2 diabetes mellitus have slightly higher numbers of glycated proteins and more glycation sites identified.

Zhang, Qibin; Tang, Ning; Schepmoes, Athena A.; Phillips, Lawrence S.; Smith, Richard D.; Metz, Thomas O.

2008-05-01T23:59:59.000Z

151

Biomimetic Interfaces Based on Membrane Proteins for Bioelectronic  

E-Print Network [OSTI]

, R. Michael Garavito2 and R. Mark Worden1 1 Department of Chemical Engineering and Materials Science bilayer lipid membrane (tBLM) Electrochemical impedance spectroscopy (EIS) Methodology for t-throughput drug screening These interfaces can be characterized using electrochemical and optical techniques #12

152

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

SciTech Connect (OSTI)

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.

Dexin Wang

2012-03-31T23:59:59.000Z

153

Correlation of Structural Differences between Nafion/Polyaniline and Nafion/Polypyrrole Composite Membranes and Observed Transport Properties  

SciTech Connect (OSTI)

Polyaniline/Nafion and polypyrrole/Nafion composite membranes, prepared by chemical polymerization, are studied by infrared and nuclear magnetic resonance spectroscopy, and scanning electron microscopy. Differences in vanadium ion diffusion through the membranes and in the membranes area specific resistance are linked to analytical observations that polyaniline and polypyrrole interact differently with Nafion. Polypyrrole, a weakly basic polymer, binds less strongly to the sulfonic acid groups of the Nafion membrane, and thus the hydrophobic polymer aggregates in the center of the Nafion channel rather than on the hydrophilic side chains of Nafion that contain sulfonic acid groups. This results in a drastically elevated membrane resistance and an only slightly decreased vanadium ion permeation compared to a Nafion membrane. Polyaniline on the other hand is a strongly basic polymer, which forms along the sidewalls of the Nafion pores and on the membrane surface, binding tightly to the sulfonic acid groups of Nafion. This leads to a more effective reduction in vanadium ion transport across the polyaniline/Nafion membranes and the increase in membrane resistance is less severe. The performance of selected polypyrrole/Nafion composite membranes is tested in a static vanadium redox cell. Increased coulombic efficiency, compared to a cell employing Nafion, further confirms the reduced vanadium ion transport through the composite membranes.

Schwenzer, Birgit; Kim, Soowhan; Vijayakumar, M.; Yang, Zhenguo; Liu, Jun

2011-04-15T23:59:59.000Z

154

Biological Detergents Guide for solubilization of membrane proteins  

E-Print Network [OSTI]

, but their solu- bilization and purification is more challenging because most of these proteins are present hydrophobic carbon chain at the other end. The polar group forms hydrogen bonds with water molecules, while be affected by other components of the biological system, such as lipids, proteins, pH, ionic strength

Lebendiker, Mario

155

Dynamics of a vesicle as a cell mimic: Effects of interior structure, cross-membrane transport, and interaction with filaments  

E-Print Network [OSTI]

Dynamics of a vesicle as a cell mimic: Effects of interior structure, cross-membrane transport, and interaction with filaments The biological membrane is, in essence, a thermodynamically-nonequilibrium lipid bilayer [6, 30, 34, 43, 47] with a variety of molecular motors, ion pumps, or channels residing within [19

Young, Yuan N.

156

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)

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.

Rogers, J.D.

1994-08-04T23:59:59.000Z

157

Synthesizing Membrane Proteins Using In Vitro Methodology | Argonne  

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

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158

ccsd-00014522,version1-5Oct2006 Co-transport-induced instability of membrane voltage in tip-growing cells  

E-Print Network [OSTI]

ccsd-00014522,version1-5Oct2006 Co-transport-induced instability of membrane voltage in tip at the same time. It is shown that these co-transporters destabilize generically the membrane voltage- tive dynamics and activity of membrane ion channels. Action potential and cardiac excitation spiral

Paris-Sud XI, Université de

159

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

E-Print Network [OSTI]

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

Walter, Peter

160

Sartobind Protein A 75 Membrane Adsorbers Operating Instructions  

E-Print Network [OSTI]

from the cell wall of specific Staphylococcus aureus strains has the ability to specifically bind several mg. The 15 layer device Sartobind Protein A 75 is perfectly designed as a down scale unit +4°C temperature Storage buffer PBS, 0.1 M sodium phosphate pH 7.0 - 8.0 and 0.02% azide Table 1

Lebendiker, Mario

Note: This page contains sample records for the topic "membrane transport proteins" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


161

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

SciTech Connect (OSTI)

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.

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

2010-07-23T23:59:59.000Z

162

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

E-Print Network [OSTI]

supporting nascent chain occupancy an aqueous channel would be obtained (Crowley et al., 1994). The secretory protein preprolactin (pPL) was used in early studies to glean information about the structure of the translocon and the cotranslational translocation... process. Aminoacyl-tRNA analogs were used to site specifically incorporate water-sensitive fluorescent probes into the nascent chain of pPL during its synthesis by the ribosome (Crowley et al., 1994; Crowley et al., 1993). Fluorescence lifetime...

Jongsma, Candice Gene

2009-05-15T23:59:59.000Z

163

Chemical crosslinking and mass spectrometry studies of the structure and dynamics of membrane proteins and receptors.  

SciTech Connect (OSTI)

Membrane proteins make up a diverse and important subset of proteins for which structural information is limited. In this study, chemical cross-linking and mass spectrometry were used to explore the structure of the G-protein-coupled photoreceptor bovine rhodopsin in the dark-state conformation. All experiments were performed in rod outer segment membranes using amino acid 'handles' in the native protein sequence and thus minimizing perturbations to the native protein structure. Cysteine and lysine residues were covalently cross-linked using commercially available reagents with a range of linker arm lengths. Following chemical digestion of cross-linked protein, cross-linked peptides were identified by accurate mass measurement using liquid chromatography-fourier transform mass spectrometry and an automated data analysis pipeline. Assignments were confirmed and, if necessary, resolved, by tandem MS. The relative reactivity of lysine residues participating in cross-links was evaluated by labeling with NHS-esters. A distinct pattern of cross-link formation within the C-terminal domain, and between loop I and the C-terminal domain, emerged. Theoretical distances based on cross-linking were compared to inter-atomic distances determined from the energy-minimized X-ray crystal structure and Monte Carlo conformational search procedures. In general, the observed cross-links can be explained by re-positioning participating side-chains without significantly altering backbone structure. One exception, between C3 16 and K325, requires backbone motion to bring the reactive atoms into sufficient proximity for cross-linking. Evidence from other studies suggests that residues around K325 for a region of high backbone mobility. These findings show that cross-linking studies can provide insight into the structural dynamics of membrane proteins in their native environment.

Haskins, William E.; Leavell, Michael D.; Lane, Pamela; Jacobsen, Richard B.; Hong, Joohee; Ayson, Marites J.; Wood, Nichole L.; Schoeniger, Joseph S.; Kruppa, Gary Hermann; Sale, Kenneth L.; Young, Malin M.; Novak, Petr

2005-03-01T23:59:59.000Z

164

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

SciTech Connect (OSTI)

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.

Air Products and Chemicals

2008-09-30T23:59:59.000Z

165

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

SciTech Connect (OSTI)

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.

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

2011-07-01T23:59:59.000Z

166

ZERO EMISSION POWER PLANTS USING SOLID OXIDE FUEL CELLS AND OXYGEN TRANSPORT MEMBRANES  

SciTech Connect (OSTI)

Over 16,700 hours of operational experience was gained for the Oxygen Transport Membrane (OTM) elements of the proposed SOFC/OTM zero-emission power generation concept. It was repeatedly demonstrated that OTMs with no additional oxidation catalysts were able to completely oxidize the remaining depleted fuel in a simulated SOFC anode exhaust at an O{sub 2} flux that met initial targets. In such cases, neither residual CO nor H{sub 2} were detected to the limits of the gas chromatograph (<10 ppm). Dried OTM afterburner exhaust streams contained up to 99.5% CO{sub 2}. Oxygen flux through modified OTMs was double or even triple that of the standard OTMs used for the majority of testing purposes. Both the standard and modified membranes in laboratory-scale and demonstration-sized formats exhibited stable performance over extended periods (2300 to 3500 hours or 3 to 5 months). Reactor contaminants, were determined to negatively impact OTM performance stability. A method of preventing OTM performance degradation was developed and proven to be effective. Information concerning OTM and seal reliability over extended periods and through various chemical and thermal shocks and cycles was also obtained. These findings were used to develop several conceptual designs for pilot (10 kWe) and commercial-scale (250 kWe) SOFC/OTM zero emission power generation systems.

G. Maxwell Christie; Troy M. Raybold

2003-06-10T23:59:59.000Z

167

Dr. Ing. /PhD / Dr.techn. Students supervised by Signe Kjelstrup 1. Torleif Holt, Transport and equilibrium properties of a cation exchange membrane (1983)  

E-Print Network [OSTI]

, (1996) 6. Magnar Ottøy, Mass and heat transfer in ion-exchange membranes (1996) 7. Belinda Flem, Peltier in the Polymer Electrolyte Membrane Fuel Cell (2007) 17. Isabella Inzoli, Coupled transports of heat and massDr. Ing. /PhD / Dr.techn. Students supervised by Signe Kjelstrup 1. Torleif Holt, Transport

Kjelstrup, Signe

168

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.

169

Two Chlamydomonas CTR Copper Transporters with a Novel Cys-Met Motif Are Localized to the Plasma Membrane and  

E-Print Network [OSTI]

Two Chlamydomonas CTR Copper Transporters with a Novel Cys-Met Motif Are Localized to the Plasma Membrane and Function in Copper Assimilation W M. Dudley Page, Janette Kropat, Patrice P. Hamel,1, California 90095-1569 Inducible high-affinity copper uptake is key to copper homeostasis in Chlamydomonas

Meier, Iris

170

Development of an spFRET method to measure structure changes in ion exchange proteins  

E-Print Network [OSTI]

transporter, major facilitator superfamily, membrane transport, membrane transporter, OxlT, single molecule, spFRET, transport protein. Tightly coupled ion exchangers, such as the AE anion exchange systems only take place at an appreciable rate if a suitable substrate ion is bound to the transport site

Novotny, Lukas

171

E-Print Network 3.0 - abc transporter proteins Sample Search...  

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

Search Sample search results for: abc transporter proteins Page: << < 1 2 3 4 5 > >> 1 ATP-binding cassette protein E is involved in gene transcription and translation in...

172

E-Print Network 3.0 - abc transport proteins Sample Search Results  

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

Search Sample search results for: abc transport proteins Page: << < 1 2 3 4 5 > >> 1 ATP-binding cassette protein E is involved in gene transcription and translation in...

173

Self-Assembly and Mass Transport in Membranes for Artificial Photosynthesis  

E-Print Network [OSTI]

for artificial photosynthesis systems ..6Photosynthesis 7up process of artificial photosynthesis membranes and open

Modestino, Miguel Antonio

2013-01-01T23:59:59.000Z

174

Transport of organelles by elastically coupled motor proteins  

E-Print Network [OSTI]

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.

Deepak Bhat; Manoj Gopalakrishnan

2014-12-17T23:59:59.000Z

175

Protein-Lipid Interactions with Fusobacterium nucleatum Major Outer Membrane Protein FomA: Spin-Label EPR and Polarized Infrared Spectroscopy  

E-Print Network [OSTI]

-Label EPR and Polarized Infrared Spectroscopy V. Anbazhagan, N. Vijay,§ J. H. Kleinschmidt,*,§ and D. Marsh, and lipid-protein interactions with FomA were characterized by using electron paramagnetic resonance (EPR-protein interaction from EPR demonstrates that FomA is not trimeric in membranes of diC(14:0) phosphatidylcholine

Kleinschmidt, Jörg H.

176

SHORT COMMUNICATION Assignment of the Norepinephrine Transporter Protein (NET1) Locus  

E-Print Network [OSTI]

SHORT COMMUNICATION Assignment of the Norepinephrine Transporter Protein (NET1) Locus to Chromosome; revisedJuly 19, 1993 The norepinephrine transporter protein (NET) is the presynaptic reuptake site assignment to chromo- some 16. We then typed a genetic polymorphism at the NET1 locus in three large

Kidd, Kenneth

177

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

DOE Patents [OSTI]

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.

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

2009-12-15T23:59:59.000Z

178

Myocardial Reloading after Extracorporeal Membrane Oxygenation Alters Substrate Metabolism While Promoting Protein Synthesis  

SciTech Connect (OSTI)

Extracorporeal membrane oxygenation (ECMO) unloads the heart providing a bridge to recovery in children after myocardial stunning. Mortality after ECMO remains high.Cardiac substrate and amino acid requirements upon weaning are unknown and may impact recovery. We assessed the hypothesis that ventricular reloading modulates both substrate entry into the citric acid cycle (CAC) and myocardial protein synthesis. Fourteen immature piglets (7.8-15.6 kg) were separated into 2 groups based on ventricular loading status: 8 hour-ECMO (UNLOAD) and post-wean from ECMO (RELOAD). We infused [2-13C]-pyruvate as an oxidative substrate and [13C6]-L-leucine, as a tracer of amino acid oxidation and protein synthesis into the coronary artery. RELOAD showed marked elevations in myocardial oxygen consumption above baseline and UNLOAD. Pyruvate uptake was markedly increased though RELOAD decreased pyruvate contribution to oxidative CAC metabolism.RELOAD also increased absolute concentrations of all CAC intermediates, while maintaining or increasing 13C-molar percent enrichment. RELOAD also significantly increased cardiac fractional protein synthesis rates by >70% over UNLOAD. Conclusions: RELOAD produced high energy metabolic requirement and rebound protein synthesis. Relative pyruvate decarboxylation decreased with RELOAD while promoting anaplerotic pyruvate carboxylation and amino acid incorporation into protein rather than to the CAC for oxidation. These perturbations may serve as therapeutic targets to improve contractile function after ECMO.

Kajimoto, Masaki; Priddy, Colleen M.; Ledee, Dolena; Xu, Chun; Isern, Nancy G.; Olson, Aaron; Des Rosiers, Christine; Portman, Michael A.

2013-08-19T23:59:59.000Z

179

Conditions for extreme sensitivity of protein diffusion in membranes to cell environments  

E-Print Network [OSTI]

We study protein diffusion in multicomponent lipid membranes close to a rigid substrate separated by a layer of viscous fluid. The large-distance, long-time asymptotics for Brownian motion are calculated using a nonlinear stochastic Navier-Stokes equation including the effect of friction with the substrate. The advective nonlinearity, neglected in previous treatments, gives only a small correction to the renormalized viscosity and diffusion coefficient at room temperature. We find, however, that in realistic multicomponent lipid mixtures, close to a critical point for phase separation, protein diffusion acquires a strong power-law dependence on temperature and the distance to the substrate $H$, making it much more sensitive to cell environment, unlike the logarithmic dependence on $H$ and very small thermal correction away from the critical point.

Yaroslav Tserkovnyak; David R. Nelson

2006-09-29T23:59:59.000Z

180

Cargo transportation by two species of motor protein  

E-Print Network [OSTI]

The cargo motion in living cells transported by two species of motor protein with different intrinsic directionality is discussed in this study. Similar to single motor movement, cargo steps forward and backward along microtubule stochastically. Recent experiments found that, cargo transportation by two motor species has a memory, it does not change its direction as frequently as expected, which means that its forward and backward step rates depends on its previous motion trajectory. By assuming cargo has only the least memory, i.e. its step direction depends only on the direction of its last step, two cases of cargo motion are detailed analyzed in this study: {\\bf (I)} cargo motion under constant external load; and {\\bf (II)} cargo motion in one fixed optical trap. Due to the existence of memory, for the first case, cargo can keep moving in the same direction for a long distance. For the second case, the cargo will oscillate in the trap. The oscillation period decreases and the oscillation amplitude increases with the motor forward step rates, but both of them decrease with the trap stiffness. The most likely location of cargo, where the probability of finding the oscillated cargo is maximum, may be the same as or may be different with the trap center, which depends on the step rates of the two motor species. Meanwhile, if motors are robust, i.e. their forward to backward step rate ratios are high, there may be two such most likely locations, located on the two sides of the trap center respectively. The probability of finding cargo in given location, the probability of cargo in forward/backward motion state, and various mean first passage times of cargo to give location or given state are also analyzed.

Yunxin Zhang

2012-11-06T23:59:59.000Z

Note: This page contains sample records for the topic "membrane transport proteins" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


181

Zero Emission Power Plants Using Solid Oxide Fuel Cells and Oxygen Transport Membranes  

SciTech Connect (OSTI)

Siemens Westinghouse Power Corp. (SWPC) is engaged in the development of Solid Oxide Fuel Cell stationary power systems. SWPC has combined DOE Developmental funds with commercial customer funding to establish a record of successful SOFC field demonstration power systems of increasing size. SWPC will soon deploy the first unit of a newly developed 250 kWe Combined Heat Power System. It will generate electrical power at greater than 45% electrical efficiency. The SWPC SOFC power systems are equipped to operate on lower number hydrocarbon fuels such as pipeline natural gas, which is desulfurized within the SOFC power system. Because the system operates with a relatively high electrical efficiency, the CO2 emissions, {approx}1.0 lb CO2/ kW-hr, are low. Within the SOFC module the desulfurized fuel is utilized electrochemically and oxidized below the temperature for NOx generation. Therefore the NOx and SOx emissions for the SOFC power generation system are near negligible. The byproducts of the power generation from hydrocarbon fuels that are released into the environment are CO2 and water vapor. This forward looking DOE sponsored Vision 21 program is supporting the development of methods to capture and sequester the CO2, resulting in a Zero Emission power generation system. To accomplish this, SWPC is developing a SOFC module design, to be demonstrated in operating hardware, that will maintain separation of the fuel cell anode gas, consisting of H2, CO, H2O and CO2, from the vitiated air. That anode gas, the depleted fuel stream, containing less than 18% (H2 + CO), will be directed to an Oxygen Transport Membrane (OTM) Afterburner that is being developed by Praxair, Inc.. The OTM is supplied air and the depleted fuel. The OTM will selectively transport oxygen across the membrane to oxidize the remaining H2 and CO. The water vapor is then condensed from the totally 1.5.DOC oxidized fuel stream exiting the afterburner, leaving only the CO2 in gaseous form. That CO2 can then be compressed and sequestered, resulting in a Zero Emission power generation system operating on hydrocarbon fuel that adds only water vapor to the environment. Praxair has been developing oxygen separation systems based on dense walled, mixed electronic, oxygen ion conducting ceramics for a number of years. The oxygen separation membranes find applications in syngas production, high purity oxygen production and gas purification. In the SOFC afterburner application the chemical potential difference between the high temperature SOFC depleted fuel gas and the supplied air provides the driving force for oxygen transport. This permeated oxygen subsequently combusts the residual fuel in the SOFC exhaust. A number of experiments have been carried out in which simulated SOFC depleted fuel gas compositions and air have been supplied to either side of single OTM tubes in laboratory-scale reactors. The ceramic tubes are sealed into high temperature metallic housings which precludes mixing of the simulated SOFC depleted fuel and air streams. In early tests, although complete oxidation of the residual CO and H2 in the simulated SOFC depleted fuel was achieved, membrane performance degraded over time. The source of degradation was found to be contaminants in the simulated SOFC depleted fuel stream. Following removal of the contaminants, stable membrane performance has subsequently been demonstrated. In an ongoing test, the dried afterburner exhaust composition has been found to be stable at 99.2% CO2, 0.4% N2 and 0.6%O2 after 350 hours online. Discussion of these results is presented. A test of a longer, commercial demonstration size tube was performed in the SWPC test facility. A similar contamination of the simulated SOFC depleted fuel stream occurred and the performance degraded over time. A second test is being prepared. Siemens Westinghouse and Praxair are collaborating on the preliminary design of an OTM equipped Afterburner demonstration unit. The intent is to test the afterburner in conjunction with a reduced size SOFC test module that has the anode gas separati

Shockling, Larry A.; Huang, Keqin; Gilboy, Thomas E. (Siemens Westinghouse Power Corporation); Christie, G. Maxwell; Raybold, Troy M. (Praxair, Inc.)

2001-11-06T23:59:59.000Z

182

Myocardial Oxidative Metabolism and Protein Synthesis during Mechanical Circulatory Support by Extracorporeal Membrane Oxygenation  

SciTech Connect (OSTI)

Extracorporeal membrane oxygenation (ECMO) provides mechanical circulatory support essential for survival in infants and children with acute cardiac decompensation. However, ECMO also causes metabolic disturbances, which contribute to total body wasting and protein loss. Cardiac stunning can also occur which prevents ECMO weaning, and contributes to high mortality. The heart may specifically undergo metabolic impairments, which influence functional recovery. We tested the hypothesis that ECMO alters oxidative. We focused on the amino acid leucine, and integration with myocardial protein synthesis. We used a translational immature swine model in which we assessed in heart (i) the fractional contribution of leucine (FcLeucine) and pyruvate (FCpyruvate) to mitochondrial acetyl-CoA formation by nuclear magnetic resonance and (ii) global protein fractional synthesis (FSR) by gas chromatography-mass spectrometry. Immature mixed breed Yorkshire male piglets (n = 22) were divided into four groups based on loading status (8 hours of normal circulation or ECMO) and intracoronary infusion [13C6,15N]-L-leucine (3.7 mM) alone or with [2-13C]-pyruvate (7.4 mM). ECMO decreased pulse pressure and correspondingly lowered myocardial oxygen consumption (~ 40%, n = 5), indicating decreased overall mitochondrial oxidative metabolism. However, FcLeucine was maintained and myocardial protein FSR was marginally increased. Pyruvate addition decreased tissue leucine enrichment, FcLeucine, and Fc for endogenous substrates as well as protein FSR. Conclusion: The heart under ECMO shows reduced oxidative metabolism of substrates, including amino acids, while maintaining (i) metabolic flexibility indicated by ability to respond to pyruvate, and (ii) a normal or increased capacity for global protein synthesis, suggesting an improved protein balance.

Priddy, MD, Colleen M.; Kajimoto, Masaki; Ledee, Dolena; Bouchard, Bertrand; Isern, Nancy G.; Olson, Aaron; Des Rosiers, Christine; Portman, Michael A.

2013-02-01T23:59:59.000Z

183

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

E-Print Network [OSTI]

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 ...

Bihr, Timo; Smith, Ana-Suncana

2015-01-01T23:59:59.000Z

184

Studies of protein folding on membranes and in crowded environments and bridging the research-teaching gap in K-12 science.  

E-Print Network [OSTI]

??This work deals with three important problems in membrane protein folding studies, namely the preparation and storage of homogeneous small unilamellar vesicles (SUV), the development (more)

Denos, Sharlene

2010-01-01T23:59:59.000Z

185

acid transport protein: Topics by E-print Network  

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

Howard W. Davidson; Clare H Mcgowan; William E Balch 1992-01-01 4 Long range transport of acid rain precursors MIT - DSpace Summary: A model of the long range transport of primary...

186

acid transport proteins: Topics by E-print Network  

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

Howard W. Davidson; Clare H Mcgowan; William E Balch 1992-01-01 4 Long range transport of acid rain precursors MIT - DSpace Summary: A model of the long range transport of primary...

187

Additional Table 3. COGs Analyzed and their Descriptions COG Protein Name  

E-Print Network [OSTI]

protein COG1446 Asparaginase COG1464 ABC-type metal ion transport system, periplasmic component Putative salt-induced outer membrane protein COG3143 Chemotaxis protein COG3158 K+ transporter COG3160 protein A COG0753 Catalase COG0755 ABC-type transport system involved in cytochrome c biogenesis, permease

Gerstein, Mark

188

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

SciTech Connect (OSTI)

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.

NONE

1995-09-05T23:59:59.000Z

189

Membrane Porters of ATP-Binding Cassette Transport Systems Are Polyphyletic  

E-Print Network [OSTI]

REVIEW Membrane Porters of ATP-Binding Cassette Transportat Springerlink.com Abstract The ATP-binding cassette (ABC)classi?ed according to the ATP hydrolyzing constituents,

Wang, Bin; Dukarevich, Maxim; Sun, Eric I.; Yen, Ming Ren; Saier, Milton H.

2009-01-01T23:59:59.000Z

190

The Crystal Structures of Yeast Get3 Suggest a Mechanism for Tail-Anchored Protein Membrane Insertion  

SciTech Connect (OSTI)

Tail-anchored (TA) proteins represent a unique class of membrane proteins that contain a single C-terminal transmembrane helix. The post-translational insertion of the yeast TA proteins into the ER membrane requires the Golgi ER trafficking (GET) complex which contains Get1, Get2 and Get3. Get3 is an ATPase that recognizes and binds the C-terminal transmembrane domain (TMD) of the TA proteins. We have determined the crystal structures of Get3 from two yeast species, S. cerevisiae and D. hansenii, respectively. These high resolution crystal structures show that Get3 contains a nucleotide-binding domain and a 'finger' domain for binding the TA protein TMD. A large hydrophobic groove on the finger domain of S. cerevisiae Get3 structure might represent the binding site for TMD of TA proteins. A hydrophobic helix from a symmetry-related Get3 molecule sits in the TMD-binding groove and mimics the TA binding scenario. Interestingly, the crystal structures of the Get3 dimers from S. cerevisiae and D. hansenii exhibit distinct conformations. The S. cerevisiae Get3 dimer structure does not contain nucleotides and maintains an 'open' conformation, while the D. hansenii Get3 dimer structure binds ADP and stays in a 'closed' conformation. We propose that the conformational changes to switch the Get3 between the open and closed conformations may facilitate the membrane insertions for TA proteins.

Hu, Junbin; Li, Jingzhi; Qian, Xinguo; Denic, Vlad; Sha, Bingdong; (UAB); (Harvard)

2010-08-16T23:59:59.000Z

191

Protein nucleocytoplasmic transport and its light regulation in plants  

E-Print Network [OSTI]

of plant cells and how light may exert its regulatory effect. Nuclear import system An overview investigations into plant nuclear transport systems and specific cases where nucleocytoplasmic transport conditions. Among a variety of environmental stimuli that affect plants, light exerts the most promi- nent

Deng, Xing-Wang

192

International Journal of Mass Spectrometry 219 (2002) 7377 Protein charge transport in gas phase  

E-Print Network [OSTI]

temperature limit, the rotational energy can be transferred with very high efficiency and hence one obtainsInternational Journal of Mass Spectrometry 219 (2002) 73­77 Protein charge transport in gas phase high charge transport efficiency. (Int J Mass Spectrom 219 (2002) 73­77) © 2002 Elsevier Science B

Sheu, Sheh-Yi

193

Does Magnesium Transport Protein (MgtE) Contribute to the Antibiotic Resistance of Pseudomonas aeruginosa?  

E-Print Network [OSTI]

Does Magnesium Transport Protein (MgtE) Contribute to the Antibiotic Resistance of Pseudomonas is more resistant to antibiotics. The purpose of this project was to find out if the magnesium transport by using two different strains of P.aeruginosa; PA14 wild-type and GGA52 mutant (without the magnesium

Zhou, Yaoqi

194

Dynamin-like protein 1 at the Golgi complex: A novel component of the sorting/targeting machinery en route to the plasma membrane  

SciTech Connect (OSTI)

The final step in the liberation of secretory vesicles from the trans-Golgi network (TGN) involves the mechanical action of the large GTPase dynamin as well as conserved dynamin-independent fission mechanisms, e.g. mediated by Brefeldin A-dependent ADP-ribosylated substrate (BARS). Another member of the dynamin family is the mammalian dynamin-like protein 1 (DLP1/Drp1) that is known to constrict and tubulate membranes, and to divide mitochondria and peroxisomes. Here, we examined a potential role for DLP1 at the Golgi complex. DLP1 localized to the Golgi complex in some but not all cell lines tested, thus explaining controversial reports on its cellular distribution. After silencing of DLP1, an accumulation of the apical reporter protein YFP-GL-GPI, but not the basolateral reporter VSVG-SP-GFP at the Golgi complex was observed. A reduction in the transport of YFP-GL-GPI to the plasma membrane was confirmed by surface immunoprecipitation and TGN-exit assays. In contrast, YFP-GL-GPI trafficking was not disturbed in cells silenced for BARS, which is involved in basolateral sorting and trafficking of VSVG-SP-GFP in COS-7 cells. Our data indicate a new role for DLP1 at the Golgi complex and thus a role for DLP1 as a novel component of the apical sorting machinery at the TGN is discussed.

Bonekamp, Nina A. [Centre for Cell Biology and Department of Biology, University of Aveiro, Campus Universitario de Santiago, 3810-193 Aveiro (Portugal)] [Centre for Cell Biology and Department of Biology, University of Aveiro, Campus Universitario de Santiago, 3810-193 Aveiro (Portugal); Vormund, Kerstin; Jacob, Ralf [Department of Cell Biology and Cell Pathology, University of Marburg, Robert-Koch-Str. 6, 35037 Marburg (Germany)] [Department of Cell Biology and Cell Pathology, University of Marburg, Robert-Koch-Str. 6, 35037 Marburg (Germany); Schrader, Michael, E-mail: mschrader@ua.pt [Centre for Cell Biology and Department of Biology, University of Aveiro, Campus Universitario de Santiago, 3810-193 Aveiro (Portugal)] [Centre for Cell Biology and Department of Biology, University of Aveiro, Campus Universitario de Santiago, 3810-193 Aveiro (Portugal)

2010-12-10T23:59:59.000Z

195

Self-Assembly and Mass Transport in Membranes for Artificial Photosynthesis  

E-Print Network [OSTI]

45 CHAPTER 3. SELF-ASSEMBLY AND TRANSPORT LIMITATIONS IN7371. CHAPTER 3. SELF-ASSEMBLY AND TRANSPORT LIMITATIONS IN2. CONTROLLING NANOROD SELF-ASSEMBLY IN POLYMER THIN-FILMS

Modestino, Miguel Antonio

2013-01-01T23:59:59.000Z

196

Spectroscopic studies of tryptophan and membrane- associated peptides  

E-Print Network [OSTI]

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

Schlamadinger, Diana Elizabeth

2011-01-01T23:59:59.000Z

197

Active membrane fluctuations studied by micropipet aspiration J.-B. Manneville,1  

E-Print Network [OSTI]

, mostly performed by proteins embedded inside the lipid bi- layer, such as solute transport via ion channels or pumps, cell locomotion and adhesion, membrane transport through exo- cytic and endocyticActive membrane fluctuations studied by micropipet aspiration J.-B. Manneville,1 P. Bassereau,1

Ramaswamy, Sriram

198

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

E-Print Network [OSTI]

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...

Park, Yong Hun

2009-05-15T23:59:59.000Z

199

Experimental characterization of water sorption and transport properties of polymer electrolyte membranes for fuel cells.  

E-Print Network [OSTI]

??L'objectif gnral de cette thse de doctorat est de caractriser les proprits de membranes PFSA de type Nafion N115 et Nafion NRE212 en termes de (more)

Maldonado Snchez, Libeth

2012-01-01T23:59:59.000Z

200

Self-Assembly and Mass Transport in Membranes for Artificial Photosynthesis  

E-Print Network [OSTI]

membranes are in hydrogen fuel- cells and electrolyzers. Thefuel cells and electrolyzers used both for hydrogenhydrogen production and device geometry requirements dictated by the light absorption. In fuel cells,

Modestino, Miguel Antonio

2013-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "membrane transport proteins" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


201

A trans-outer membrane porin-cytochrome protein complex for extracellular electron transfer by Geobacter sulfurreducens PCA  

SciTech Connect (OSTI)

The multiheme, outer membrane c-type cytochrome (c-Cyt) OmcB of Geobacter sulfurreducens was previously proposed to mediate electron transfer across the outer membrane. However, the underlying mechanism has remained uncharacterized. In G. sulfurreducens, the omcB gene is part of two tandem four-gene clusters, each is predicted to encode a transcriptional factor (OrfR/OrfS), a porin-like outer membrane protein (OmbB/OmbC), a periplasmic c-type cytochrome (OmaB/OmaC), and an outer membrane c-Cyt (OmcB/OmcC), respectively. Here we showed that OmbB/OmbC, OmaB/OmaC and OmcB/OmcC of G. sulfurreducens PCA formed the porin-cytochrome (Pcc) protein complexes, which were involved in transferring electrons across the outer membrane. The isolated Pcc protein complexes reconstituted in proteoliposomes transferred electrons from reduced methyl viologen across the lipid bilayer of liposomes to Fe(III)-citrate and ferrihydrite. The pcc clusters were found in all eight sequenced Geobacter and 11 other bacterial genomes from six different phyla, demonstrating a widespread distribution of Pcc protein complexes in phylogenetically diverse bacteria. Deletion of ombB-omaB-omcB-orfS-ombC-omaC-omcC gene clusters had no impact on the growth of G. sulfurreducens PCA with fumarate, but diminished the ability of G. sulfurreducens PCA to reduce Fe(III)-citrate and ferrihydrite. Complementation with the ombB-omaB-omcB gene cluster restored the ability of G. sulfurreducens PCA to reduce Fe(III)-citrate and ferrihydrite.

Liu, Yimo; Wang, Zheming; Liu, Juan; Levar, Caleb; Edwards, Marcus; Babauta, Jerome T.; Kennedy, David W.; Shi, Zhi; Beyenal, Haluk; Bond, Daniel R.; Clarke, Thomas A.; Butt, Julea N.; Richardson, David J.; Rosso, Kevin M.; Zachara, John M.; Fredrickson, Jim K.; Shi, Liang

2014-09-24T23:59:59.000Z

202

Aptamer Directly Evolved from Live Cells Recognizes Membrane Bound Immunoglobin  

E-Print Network [OSTI]

. These include cell signaling, cell-cell interactions, ion/solute transport that facilitates the exchangeAptamer Directly Evolved from Live Cells Recognizes Membrane Bound Immunoglobin Heavy Mu Chain, and Weihong Tan The identification of tumor related cell membrane protein targets is important

Tan, Weihong

203

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

SciTech Connect (OSTI)

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.

Liss, William E; Cygan, David F

2013-04-17T23:59:59.000Z

204

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

SciTech Connect (OSTI)

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.

So, Hongyun; Pisano, Albert P. [Department of Mechanical Engineering, Berkeley Sensor and Actuator Center, University of California, Berkeley, California 94720 (United States)] [Department of Mechanical Engineering, Berkeley Sensor and Actuator Center, University of California, Berkeley, California 94720 (United States); Cheng, Jim C. [Department of Electrical Engineering, Berkeley Sensor and Actuator Center, University of California, Berkeley, California 94720 (United States)] [Department of Electrical Engineering, Berkeley Sensor and Actuator Center, University of California, Berkeley, California 94720 (United States)

2013-10-14T23:59:59.000Z

205

E-Print Network 3.0 - ankyrin-repeat membrane protein Sample...  

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

10 Stabilizing IB by "Consensus" Design Diego U. Ferreiro1,3 Summary: Keywords: protein folding; ankyrin repeat protein; NF-B; transcription factor; repeat protein...

206

Axonal Transport of Microtubule-Associated Protein 1B (MAP1B) in the Sciatic Nerve of Adult Rat: Distinct Transport Rates of Different  

E-Print Network [OSTI]

transported with slow com- ponents a and b (SCa and SCb). In peripheral nerves, the transport velocity of SCa, which includes neurofilaments and tubulin, is 12 mm/d, whereas SCb, which includes actin, tu- bulin transport components SCa and SCb. Several other proteins were detected within the component that moved

Fischer, Itzhak

207

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)

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.

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

2009-01-15T23:59:59.000Z

208

Measurements of water uptake and transport properties in anion-exchange membranes  

E-Print Network [OSTI]

the cost of the fuel cell systems. Although promising, conventional liquid electrolyte- based alkaline fuel Keywords: Direct ethanol fuel cells Anion-exchange membrane Water uptake Water diffusivity Mass. All rights reserved. 1. Introduction Alkaline fuel cells allow the use of non-platinum (Pt) catalysts

Zhao, Tianshou

209

Lipid Dynamics and ProteinLipid Interactions in 2D Crystals Formed with the ?-Barrel Integral Membrane Protein VDAC1  

E-Print Network [OSTI]

We employ a combination of [superscript 13]C/[superscript 15]N magic angle spinning (MAS) NMR and [superscript 2]H NMR to study the structural and functional consequences of different membrane environments on VDAC1 and, ...

Ong, Ta-Chung

210

Protein domain organisation: adding order  

E-Print Network [OSTI]

4 81811 membrane_organization_and_biogenesis 4 81811 vesicle-mediated_transport 4 81811 intracellular_protein_transport 4 54117 immune_response 3 54117 negative_regulation_of_cell_proliferation 3 54117 signal_transducer_activity 3 50715 ligase... -type_endopeptidase_activity 4 69055 binding 3 52788 identical_protein_binding 4 54585 nucleoside-triphosphatase_activity 3 54585 ATPase_activity 3 54585 protein_transport 3 54585 caspase_activation 3 54585 unfolded_protein_response 3 54585 magnesium_ion_binding 3 54585 protein...

Kummerfeld, Sarah K; Teichmann, Sarah A

2009-01-29T23:59:59.000Z

211

Transmembrane protein PERP is a component of tessellate junctions and of other junctional and non-junctional plasma membrane regions in diverse epithelial and epithelium-derived cells  

E-Print Network [OSTI]

Protein PERP (p53 apoptosis effector related to PMP-22) is a small (21.4 kDa) transmembrane polypeptide with an amino acid sequence indicative of a tetraspanin character. It is enriched in the plasma membrane and apparently ...

Franke, Werner W.

212

Self-Induced Docking Site of a Deeply Embedded Peripheral Membrane Protein  

E-Print Network [OSTI]

paramagnetic resonance (EPR). Noting that in the membrane-bound state the three calcium binding loops features: an eight-strand antiparallel b-sandwich, and three negatively charged calcium-binding loops (CBLs are complexed to two calcium ions, we initially restrained the calcium ions at the membrane depth determined

White, Stephen

213

Ammonium Bicarbonate Transport in Anion Exchange Membranes for Salinity Gradient Energy  

E-Print Network [OSTI]

such as reverse electrodialysis (RED) rely on highly selective anion transport through polymeric anion exchange to address global energy needs, such as reverse electro- dialysis1-4 (RED), capacitive energy extraction based on Donnan potential5 (CDP), and capacitive reverse electro- dialysis6 (CRED), has encouraged

214

Molecular Mechanism of Biological Proton Transport  

SciTech Connect (OSTI)

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.

Pomes, R.

1998-09-01T23:59:59.000Z

215

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]

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...

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

2015-01-01T23:59:59.000Z

216

Recent Progress in the Structure Determination of GPCRs, a Membrane Protein Family with High Potential as Pharmaceutical Targets  

SciTech Connect (OSTI)

G protein-coupled receptors (GPCRs) constitute a highly diverse and ubiquitous family of integral membrane proteins, transmitting signals inside the cells in response to an assortment of disparate extra-cellular stimuli. Their strategic location on the cell surface and their involvement in crucial cellular and physiological processes turn these receptors into highly important pharmaceutical targets. Recent technological developments aimed at stabilization and crystallization of these receptors have led to significant breakthroughs in GPCR structure determination efforts. One of the successful approaches involved receptor stabilization with the help of a fusion partner combined with crystallization in lipidic cubic phase (LCP). The success of using an LCP matrix for crystallization is generally attributed to the creation of a more native, membrane-like stabilizing environment for GPCRs just prior to nucleation and to the formation of type I crystal lattices, thus generating highly ordered and strongly diffracting crystals. Here they describe protocols for reconstituting purified GPCRs in LCP, performing pre-crystallization assays, setting up crystallization trials in manual mode, detecting crystallization hits, optimizing crystallization conditions, harvesting, and collecting crystallographic data. The protocols provide a sensible framework for approaching crystallization of stabilized GPCRs in LCP, however, as in any crystallization experiment, extensive screening and optimization of crystallization conditions as well as optimization of protein construct and purification steps are required. The process remains risky and these protocols do not necessarily guarantee success.

Cherezov, Vadim; Abola, Enrique; Stevens, Raymond C.

2012-05-09T23:59:59.000Z

217

Angiotensin 2 directly increases rabbit renal brush-border membrane sodium transport: Presence of local signal transduction system  

SciTech Connect (OSTI)

In the present study, the authors have examined the direct actions of angiotensin II (AII) in rabbit renal brush border membrane (BBM) where binding sites for AII exist. Addition of AII (10(-11)-10(-7) M) was found to stimulate 22Na+ uptake by the isolated BBM vesicles directly. All did not affect the Na(+)-dependent BBM glucose uptake, and the effect of AII on BBM 22Na+ uptake was inhibited by amiloride, suggesting the involvement of Na+/H+ exchange mechanism. BBM proton permeability as assessed by acridine orange quenching was not affected by AII, indicating the direct effect of AII on Na+/H+ antiport system. In search of the signal transduction mechanism, it was found that AII activated BBM phospholipase A2 (PLA) and that BBM contains a 42-kDa guanine nucleotide-binding regulatory protein (G-protein) that underwent pertussis toxin (PTX)-catalyzed ADP-ribosylation. Addition of GTP potentiated, while GDP-beta S or PTX abolished, the effects of AII on BBM PLA and 22Na+ uptake, suggesting the involvement of G-protein in AII's actions. On the other hand, inhibition of PLA by mepacrine prevented AII's effect on BBM 22Na+ uptake, and activation of PLA by mellitin or addition of arachidonic acid similarly enhanced BBM 22Na+ uptake, suggesting the role of PLA activation in mediating AII's effect on BBM 22Na+ uptake. In summary, results of the present study show a direct stimulatory effect of AII on BBM Na+/H+ antiport system, and suggest the presence of a local signal transduction system involving G-protein mediated PLA activation.

Morduchowicz, G.A.; Sheikh-Hamad, D.; Dwyer, B.E.; Stern, N.; Jo, O.D.; Yanagawa, N. (Sepulveda Veterans Administration, CA (USA))

1991-05-01T23:59:59.000Z

218

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

E-Print Network [OSTI]

on identifying major impurity and optimization of solution properties for target protein purification. The second approach consisted of designing an adsorbent that interacted specifically with the target molecule. The first study included modification of protein...

Imam, Tahmina

2010-01-16T23:59:59.000Z

219

Salinity tolerance in plants: attempts to manipulate ion transport  

E-Print Network [OSTI]

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.

Vadim Volkov

2014-11-06T23:59:59.000Z

220

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

E-Print Network [OSTI]

, respectively. A series of operations including pH adjustment (8.0), agitation (250 rpm, 30 min), sonication (40 dB, 20 min), homogenization (3 min), and centrifugation (3,000 x g, 15 min) were followed. For the membrane processing, the ultrafiltration cartridge...

Kim, Hyun Jung

2003-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "membrane transport proteins" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


221

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

E-Print Network [OSTI]

), which associates with anionic membranes in response to binding Ca^(2+) ions in the first step of activation. The objective of this work was to determine the specific role of divalent metal ions on the modulation of C2alpha structure, function...

Morales-Rivera, Krystal A.

2013-11-26T23:59:59.000Z

222

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]

of Coherence and Energy Storage by Membrane Transporters in an RLC Electric Circuit Imre Derényi and R. Dean that oscillating or fluctuating electric fields can drive thermodynami- cally uphill transport of ions catalyzed by a molecular ion pump, the Na,K-ATPase. Theory suggests that if the transport reaction is very far from

Derényi, Imre

223

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

E-Print Network [OSTI]

to-protein ratio and the mass of the entire PDC, and thuswith the precise PDC composition. They also allow us to

2009-01-01T23:59:59.000Z

224

Automated Builder and Database of Protein/Membrane Complexes for Molecular Dynamics Simulations  

E-Print Network [OSTI]

it if necessary, and generate a structure topology file. Users can upload their own pre-oriented protein structure, or specify PDB entry ID and a database, either of PDB database [14] or OPM database [25]. Protein structures from OPM database are pre... to the Z-axis. In the case that the protein structure is not easily aligned with the available options, one should align it in a local machine and then upload it. One can skip the alignment step for the protein structures from OPM database [25] or pre...

Jo, Sunhwan; Kim, Taehoon; Im, Wonpil

2007-09-12T23:59:59.000Z

225

Folding amphipathic helices into membranes: Amphiphilicity trumps hydrophobicity  

E-Print Network [OSTI]

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

Fernndez-Vidal, Mnica; Jayasinghe, Sajith; Ladokhin, Alexey S; White, Stephen H

2007-01-01T23:59:59.000Z

226

Nanocomposite Membranes for Complex Separations  

E-Print Network [OSTI]

membranes for reverse-selective removal of alkanes from light gases, 2) defect-free inorganic nanocomposite membranes that have uniform pores, and 3) nanocomposite membranes for minimizing protein fouling in microfiltration applications. Reverse-selective...

Yeu, Seung Uk

2010-10-12T23:59:59.000Z

227

High-Order Membrane Complexes from Activated G-Protein Subunits  

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:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth7-1D: Vegetation ProposedUsingFun withconfinement plasmas in thein the AssemblyHigh-Order Membrane Complexes

228

Water-Protein Interactions of an Arginine-Rich Membrane Peptide in Lipid Bilayers Investigated by Solid-State Nuclear Magnetic Resonance Spectroscopy  

E-Print Network [OSTI]

Water-Protein Interactions of an Arginine-Rich Membrane Peptide in Lipid Bilayers InvestigatedVised Manuscript ReceiVed: February 16, 2010 The interaction of an arginine (Arg) residue with water HETCOR experiments, we unambiguously assigned a water-guanidinium cross-peak that is distinct from

Hong, Mei

229

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

E-Print Network [OSTI]

. In order to explore the potential regulatory role of the cellular lipid environment in PM targeting of lipidated proteins, young adult mouse colon (YAMC) cells were treated with 50 µM DHA, LA, or oleic acid (OA) 24 h prior to and 36-48 h after transfection...

Seo, Jeongmin

2006-04-12T23:59:59.000Z

230

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

E-Print Network [OSTI]

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

Stockie, John

231

Operation of staged membrane oxidation reactor systems  

SciTech Connect (OSTI)

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.

Repasky, John Michael

2012-10-16T23:59:59.000Z

232

OXYGEN TRANSPORT CERAMIC MEMBRANES  

SciTech Connect (OSTI)

The mechanical properties of model systems were analyzed. A reasonably accurate finite element model was implemented and a rational metric to predict the strength of ceramic/metal concentrical joints was developed. The mode of failure of the ceramic/metal joints was determined and the importance of the mechanical properties of the braze material was assessed. Thermal cycling experiments were performed on the model systems and the results were discussed. Additionally, experiments using the concept of placing diffusion barriers on the ceramic surface to limit the extent of the reaction with the braze were performed. It was also observed that the nature and morphology of the reaction zone depends greatly on the nature of the perovskite structure being used. From the experiments, it is observed that the presence of Cr in the Fe-occupied sites decreases the tendency of Fe to segregate and to precipitate out of the lattice. In these new experiments, Ni was observed to play a major role in the decomposition of the ceramic substrate.

Dr. Sukumar Bandopadhyay; Dr. Nagendra Nagabhushana

2001-05-01T23:59:59.000Z

233

OXYGEN TRANSPORT CERAMIC MEMBRANES  

SciTech Connect (OSTI)

Conversion of natural gas to liquid fuels and chemicals is a major goal for the Nation as it enters the 21st Century. Technically robust and economically viable processes are needed to capture the value of the vast reserves of natural gas on Alaska's North Slope, and wean the Nation from dependence on foreign petroleum sources. Technologies that are emerging to fulfill this need are all based syngas as an intermediate. Syngas (a mixture of hydrogen and carbon monoxide) is a fundamental building block from which chemicals and fuels can be derived. Lower cost syngas translates directly into more cost-competitive fuels and chemicals. The currently practiced commercial technology for making syngas is either steam methane reforming (SMR) or a two-step process involving cryogenic oxygen separation followed by natural gas partial oxidation (POX). These high-energy, capital-intensive processes do not always produce syngas at a cost that makes its derivatives competitive with current petroleum-based fuels and chemicals.

Dr. Sukumar Bandopadhyay; Dr. Nagendra Nagabhushana

2002-01-01T23:59:59.000Z

234

OXYGEN TRANSPORT CERAMIC MEMBRANES  

SciTech Connect (OSTI)

The mechanical properties of model systems were analyzed. A reasonably accurate finite element model was implemented and a rational metric to predict the strength of ceramic/metal concentrical joints was developed. The mode of failure of the ceramic/metal joints was determined and the importance of the mechanical properties of the braze material was assessed. Thermal cycling experiments were performed on the model systems and the results were discussed. Additionally, experiments using the concept of placing diffusion barriers on the ceramic surface to limit the extent of the reaction with the braze were performed. It was also observed that the nature and morphology of the reaction zone depends greatly on the nature of the perovskite structure being used. From the experiments, it is observed that the presence of Cr in the Fe-occupied sites decreases the tendency of Fe to segregate and to precipitate out of the lattice. In these new experiments, Ni was observed to play a major role in the decomposition of the ceramic substrate.

Dr. Sukumar Bandopadhyay; Dr. Nagendfra Nagabhushana

2001-07-01T23:59:59.000Z

235

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)

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.

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

2012-08-14T23:59:59.000Z

236

Bismuth Dimercaptopropanol (BisBAL) Inhibits the Expression of Extracellular Polysaccharides and Proteins by Brevundimonas diminuta: Implications for Membrane Microfiltration  

SciTech Connect (OSTI)

A 2:1 molar ratio preparation of bismuth with a lipophilic dithiol (3-dimercapto-1-propanol, BAL)significantly reduced extracellular polymeric substances (EPS) expression by Brevundimonas diminuta in suspended cultures at levels just below the minimum inhibitory concentration (MIC). Total polysaccharides and proteins secreted by B. diminuta decreased by approximately 95% over a 5-day period when exposed to the bismuth-BAL chelate (BisBAL) at near MIC (12 ?M). Fourier-transform infrared spectroscopy (FTIR) suggested that a possible mechanism of biofilm disruption by BisBAL is the inhibition of carbohydrate Oacetylation. FTIR also revealed extensive homology between EPS samples with and without BisBAL treatment, with proteins, polysaccharides, and peptides varying predominantly only in the amount expressed. EPS secretion decreased following BisBAL treatment as verified by atomic force microscopy and scanning electron microscopy. Without BisBAL treatment, a slime-like EPS matrix secreted by B. diminuta resulted in biofouling and inefficient hydrodynamic backwashing of microfiltration membranes.

Badireddy, Appala R.; Chellam, Shankararaman; Yanina, Svetlana; Gassman, Paul L.; Rosso, Kevin M.

2008-02-15T23:59:59.000Z

237

Transportation  

E-Print Network [OSTI]

Transportation in ancient Egypt entailed the use of boats2007 Land transport in Roman Egypt: A study of economics andDieter 1991 Building in Egypt: Pharaonic stone masonry. New

Vinson, Steve

2013-01-01T23:59:59.000Z

238

Mechanical and Transport Properties of Layer-by-Layer Electrospun Composite Proton Exchange Membranes for Fuel Cell Applications  

E-Print Network [OSTI]

Composite membranes composed of highly conductive and selective layer-by-layer (LbL) films and electrospun fiber mats were fabricated and characterized for mechanical strength and electrochemical selectivity. The LbL ...

Mannarino, Matthew M.

239

Transport study of hafnium(IV) and zirconium(IV) ions mutual separation by using Tri-n-butyl phosphate-xylene-based supported liquid membranes  

SciTech Connect (OSTI)

A Hf transport study through supported liquid membranes has been carried out to determine flux and permeability data for this metal ion. Tri-n-butyl phosphate (TBP)-xylene-based liquid membranes supported in polypropylene hydrophobic microporous film have been used. These data for hafnium and the previous data for zirconium have furnished the Zr to Hf flux ratio (S) as a function of nitric acid and TBP concentrations of the order of 12 in a single stage at room temperature. Optimum conditions for the separation of these two metal ions appear to 5-6 TBP mol/dm{sup 3} HNO{sub 3}, concentrations {le} 2.93 mol/dm{sup 3}, and 10C. The value of S from an aqueous solution containing 2.4% Hf with respect to Zr has been found to be >125 at 10C and 1.78 mol/dm{sup 3} TBP concentration in the membrane. The technique appears to be feasible for purification of Zr respect to Hf or vice versa.

Chaudry, M.A.; Ahmed, B. (Pakistan Inst. of Nuclear Science and Technology, Islamabad (Pakistan))

1992-02-01T23:59:59.000Z

240

Engineering Development of Ceramic Membrane Reactor  

E-Print Network [OSTI]

ceramic Ion Transport Membrane (ITM) reactor system for low-cost conversion of natural gas to hydrogen;7 A Revolutionary Technology Using Ceramic Membranes Ion Transport Membranes (ITM) ­ Non-porous multiEngineering Development of Ceramic Membrane Reactor Systems for Converting Natural Gas to Hydrogen

Note: This page contains sample records for the topic "membrane transport proteins" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


241

Crystallization of Mitochondrial Respiratory Complex II fromChicken Heart: A Membrane-Protein Complex Diffracting to 2.0Angstrom  

SciTech Connect (OSTI)

Procedure is presented for preparation of diffraction-quality crystals of a vertebrate mitochondrial respiratory Complex II. The crystals have the potential to diffract to at least 2.0 Angstrom with optimization of post-crystal-growth treatment and cryoprotection. This should allow determination of the structure of this important and medically relevant membrane protein complex at near-atomic resolution and provide great detail of the mode of binding of substrates and inhibitors at the two substrate-binding sites.

Huang, Li-shar; Borders, Toni M.; Shen, John T.; Wang, Chung-Jen; Berry, Edward A.

2004-12-17T23:59:59.000Z

242

IONICALLY CONDUCTING MEMBRANES FOR HYDROGEN PRODUCTION AND  

E-Print Network [OSTI]

SEQUESTRATION Oxygen Transport Membrane Hydrogen Transport Membrane Natural Gas Coal Biomass Syngas CO/H2 WGS H2 operating experience. #12;ELTRON RESEARCH INC. Syngas Production Rate ­ 60 mL/min cm2 @ 900°C Equivalent O2 Operational Experience Under High Pressure Differential SUMMARY OF ELTRON OXYGEN TRANSPORT MEMBRANE SYNGAS

243

Support Vector Machines A Literature Based Method for Protein  

E-Print Network [OSTI]

motility and secretion P 160 5112 Inorganic ion transport and metabolism T 97 3627 Signal transduction modification, protein turnover, chaperones M 155 4079 Cell envelope biogenesis, outer membrane N 133 3110 Cell mechanisms Metabolism C 224 5594 Energy production and conversion G 171 5262 Carbohydrate transport

244

Membrane proteomic analysis of pancreatic cancer cells  

E-Print Network [OSTI]

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

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

2010-01-01T23:59:59.000Z

245

Molecular Origin of Electron Paramagnetic Resonance Line Shapes on [beta]-Barrel Membrane Proteins: The Local Solvation Environment Modulates Spin-Label Configuration  

SciTech Connect (OSTI)

In this work, electron paramagnetic resonance (EPR) spectroscopy and X-ray crystallography were used to examine the origins of EPR line shapes from spin-labels at the protein-lipid interface on the {beta}-barrel membrane protein BtuB. Two atomic-resolution structures were obtained for the methanethiosulfonate spin-label derivatized to cysteines on the membrane-facing surface of BtuB. At one of these sites, position 156, the label side chain resides in a pocket formed by neighboring residues; however, it extends from the protein surface and yields a single-component EPR spectrum in the crystal that results primarily from fast rotation about the fourth and fifth bonds linking the spin-label to the protein backbone. In lipid bilayers, site 156 yields a multicomponent spectrum resulting from different rotameric states of the labeled side chain. Moreover, changes in the lipid environment, such as variations in bilayer thickness, modulate the EPR spectrum by modulating label rotamer populations. At a second site, position 371, the labeled side chain interacts with a pocket on the protein surface, leading to a highly immobilized single-component EPR spectrum that is not sensitive to hydrocarbon thickness. This spectrum is similar to that seen at other sites that are deep in the hydrocarbon, such as position 170. This work indicates that the rotameric states of spin-labels on exposed hydrocarbon sites are sensitive to the environment at the protein-hydrocarbon interface, and that this environment may modulate weak interactions between the labeled side chain and the protein surface. In the case of BtuB, lipid acyl chain packing is not symmetric around the {beta}-barrel, and EPR spectra from labeled hydrocarbon-facing sites in BtuB may reflect this asymmetry. In addition to facilitating the interpretation of EPR spectra of membrane proteins, these results have important implications for the use of long-range distance restraints in protein structure refinement that are obtained from spin-labels.

Freed, Daniel M.; Khan, Ali K.; Horanyi, Peter S.; Cafiso, David S. (UV)

2012-01-20T23:59:59.000Z

246

Dlg1 in the vesicle trafficking machinery Emerging role of the scaffolding protein Dlg1 in interfacing  

E-Print Network [OSTI]

recruit components of the vesicle trafficking machinery either to the plasma membrane or to transport required for transport; GluR1, AMPA receptor subunit; Glut4, glucose transporter type 4; GUK, guanylate complexes, including receptors, ion channels and signaling proteins, at specialized zones of the plasma

Paris-Sud XI, Université de

247

Dissecting functional domains on nucleotide sugar transporters. Ignacio Moreno, Adrian Moreno, Maribel Donoso, Carol Moraga, Jean-Christophe Nebel*, Ariel Orellana.  

E-Print Network [OSTI]

Dissecting functional domains on nucleotide sugar transporters. Ignacio Moreno, Adrian Moreno.moreno@uandresbello.edu Nucleotide sugar transporters (NSTs) are membrane proteins involved in the translocation of nucleotide sugars involving structure prediction using ab initio software will be discussed. Nucleotide sugar transporters

Nebel, Jean-Christophe

248

Intestinal-fatty acid binding protein and lipid transport in human intestinal epithelial cells  

SciTech Connect (OSTI)

Intestinal-fatty acid binding protein (I-FABP) is a 14-15 kDa cytoplasmic molecule highly expressed in the enterocyte. Although different functions have been proposed for various FABP family members, the specific function of I-FABP in human intestine remains unclear. Here, we studied the role of I-FABP in molecularly modified normal human intestinal epithelial cells (HIEC-6). cDNA transfection resulted in 90-fold I-FABP overexpression compared to cells treated with empty pQCXIP vector. The high-resolution immunogold technique revealed labeling mainly in the cytosol and confirmed the marked phenotype abundance of I-FABP in cDNA transfected cells. I-FABP overexpression was not associated with alterations in cell proliferation and viability. Studies using these transfected cells cultured with [{sup 14}C]oleic acid did not reveal higher efficiency in de novo synthesis or secretion of triglycerides, phospholipids, and cholesteryl esters compared to cells treated with empty pQCXIP vector only. Similarly, the incubation with [{sup 35}S]methionine did not disclose a superiority in the biogenesis of apolipoproteins (apo) A-I, A-IV, B-48, and B-100. Finally, cells transfected with I-FABP did not exhibit an increased production of chylomicrons, VLDL, LDL, and HDL. Our observations establish that I-FABP overexpression in normal HIEC-6 is not related to cell proliferation, lipid esterification, apo synthesis, and lipoprotein assembly, and, therefore, exclude its role in intestinal fat transport.

Montoudis, Alain [Department of Nutrition, Universite de Montreal and Research Center, CHU Sainte Justine, 3175 Cote Ste-Catherine, Montreal, Que., H3T 1C5 (Canada); Delvin, Edgard [Department of Biochemistry, Universite de Montreal and Research Center, CHU Sainte Justine, 3175 Cote Ste-Catherine, Montreal, Que., H3T 1C5 (Canada); Canadian Institute of Health Research, Group of the Functional Development and Physiopathology of the Digestive Tract, and Department of Anatomy and Cellular Biology, Faculty of Medicine and Health Sciences, Universite de Sherbrooke, Sherbrooke, Que., Canada J1H 5N4 (Canada); Menard, Daniel [Department of Pathology and Cell Biology, Universite de Montreal and Research Center, CHU Sainte Justine, 3175 Cote Ste-Catherine, Montreal, Que., H3T 1C5 (Canada); Canadian Institute of Health Research, Group of the Functional Development and Physiopathology of the Digestive Tract, and Department of Anatomy and Cellular Biology, Faculty of Medicine and Health Sciences, Universite de Sherbrooke, Sherbrooke, Que., J1H 5N4 (Canada)] (and others)

2006-01-06T23:59:59.000Z

249

Studies on the in situ electrooxidation and selective permeation of cerium(IV) across a bulk liquid membrane containing tributyl phosphate as the ion transporter  

SciTech Connect (OSTI)

The results of experiments carried out to develop a liquid membrane (LM) technique for the extractive permeation of cerium from nitric acid solutions are described. In-situ electrooxidation of Ce{sup 3+} to extractable Ce{sup 4+} and its transport across bulk LM (BLM) composed of tri-n-butyl phosphate (TBP)/dodecane mixtures was systematically studied under varied hydrodynamical and chemical conditions. The permeability of metal ions across the BLM was dependent on the efficiency of extraction, ionic activity of feed solutions, stirring rate, composition of the receiving phase, etc. The transport rates were found to vary linearly (a log-log correlation) with the cation concentration in feed solutions and concentration of TBP in BLM. A permeation velocity equation for cerium ion through the membrane has been proposed. More than 90% permeation of Ce with a maximum flux of 8.63 x 10{sup {minus}5} mol/m{sup 2}/s could be accomplished under the experimental conditions: stirring rates at feed and strip solutions were 380 and 300 rpm, respectively; feed was 1 mol/dm{sup 3} of HNO{sub 3} containing 0.005 mol/dm{sup 3} Ce(NO{sub 3}){sub 3}; LM contained 30% TBP/dodecane; and the receiving phase was distilled water. Radiochemically pure Ce-144 was partitioned from the Ce-Am mixture obtained by extraction chromatographic fractioning of high level radioactive waste. This also resulted in the purification of Am-241 in the feed solution with a decontamination factor of {approximately} 12 from Ce.

Kedari, C.S.; Pandit, S.S.; Ramanujam, A. [Bhabha Atomic Research Centre, Trombay (India). Fuel Reprocessing Div.] [Bhabha Atomic Research Centre, Trombay (India). Fuel Reprocessing Div.

1999-06-01T23:59:59.000Z

250

Salt Concentration Differences Alter Membrane Resistance in Reverse Electrodialysis Stacks  

E-Print Network [OSTI]

,3,4 Selective transport of ions through the membranes creates an electric potential across pairs of AEMs by changing the membrane polymer chemistry and/or membrane form factor.9-13 The ion transport properties on either side of the membrane on ion transport properties must be studied to improve our under- standing

251

MEMBRANE FUNCTION, Part 2. Passive Movement: Diffusion, Osmosis, and Gibbs-Donnan Equilibrium 1  

E-Print Network [OSTI]

such as ion gradients or sunlight. I. Passive transport Passive transport is diffusion through a membrane of the membrane. This movement is entirely by the process of diffusion (to be covered below) · ions and polar. Mechanisms of Membrane Transport There are two general modes of transport across membranes: passive transport

Prestwich, Ken

252

Grafted polyelectrolyte membranes for lithium batteries and fuel cells  

E-Print Network [OSTI]

MEMBRANES FOR LITHIUM BATTERIES AND FUEL CELLS. John Kerralso be discussed. Lithium Batteries for Transportation andpolymer membrane for lithium batteries. This paper will give

Kerr, John B.

2003-01-01T23:59:59.000Z

253

Topical Review Fluctuations and Fractal Noise in Biological Membranes  

E-Print Network [OSTI]

and transport of ions and molecules across biological membranes. We know that ion transport through mem- branes in electrical properties associated with cell membrane ion transport. Key words: Brownian motion -- Cell membrane elec- trical properties -- Fractals -- Gaussian noise -- Ion transport -- Nonlinear dynamics

254

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

DOE Patents [OSTI]

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.

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

2013-02-05T23:59:59.000Z

255

Huntingtin is required for ER-to-Golgi transport and for secretory vesicle fusion at the plasma membrane  

E-Print Network [OSTI]

et al., 2009; Presley et al., 1997; Roghi and Allan, 1999). To determine whether compromising dynein activity affects the ER-to-Golgi GFP-hGH transport assay, we performed siRNA knockdown of the dynein associated intermediate chain (DIC... cells. Nature. 389:81-85. Roghi, C., and V.J. Allan. 1999. Dynamic association of cytoplasmic dynein heavy chain 1a with the Golgi apparatus and intermediate compartment. J Cell Sci. 112 ( Pt 24):4673-4685. Sahlender, D.A., R.C. Roberts, S.D. Arden...

Brandstaetter, Hemma; Kruppa, Antonina J.; Buss, Folma

2014-10-31T23:59:59.000Z

256

Research and Development of Proton-Exchange Membrane (PEM) Fuel Cell System for Transportation Applications: Initial Conceptual Design Report  

SciTech Connect (OSTI)

This report addresses Task 1.1, model development and application, and Task 1.2, vehicle mission definition. Overall intent is to produce a methanol-fueled 10-kW power source, and to evaluate electrochemical engine (ECE) use in transportation. Major achievements include development of an ECE power source model and its integration into a comprehensive power source/electric vehicle propulsion model, establishment of candidate FCV (fuel cell powered electric vehicle) mission requirements, initial FCV studies, and a candidate FCV recommendation for further study.

Not Available

1993-11-30T23:59:59.000Z

257

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:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsrucLas ConchasPassiveSubmittedStatusButler TinaContact-Information-Transmission SignTransport

258

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

E-Print Network [OSTI]

.................................................................................... 31 Results ............................................................................................ 33 Discussion ...................................................................................... 45 Materials and Methods... ...................................................................................... 70 Materials and Methods ................................................................... 76 IV RETROGRADE INTRAFLAGELLAR TRANSPORT BY CYTOPLASMIC DYNEIN-2 IS REQUIRED FOR OUTER SEGMENT EXTENSION...

Krock, Bryan L.

2010-07-14T23:59:59.000Z

259

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

E-Print Network [OSTI]

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

Clark, Patricia L.

260

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

SciTech Connect (OSTI)

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.

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

2012-07-11T23:59:59.000Z

Note: This page contains sample records for the topic "membrane transport proteins" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


261

Identifying Calcium Channels and Porters in Plant Membranes  

SciTech Connect (OSTI)

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.

Sze, Heven

1998-04-01T23:59:59.000Z

262

Ninth International Workshop on Plant Membrane Biology  

SciTech Connect (OSTI)

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.

Not Available

1993-12-31T23:59:59.000Z

263

On a novel rate theory for transport in narrow ion channels and its application to the study of flux optimization via geometric effects  

E-Print Network [OSTI]

On a novel rate theory for transport in narrow ion channels and its application to the study passage time to describe single-ion conduction in narrow, effectively one-dimensional membrane channels. DOI: 10.1063/1.3077205 I. INTRODUCTION Ion channels are membrane proteins which enable se- lected ions

Reingruber, Jürgen

264

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

E-Print Network [OSTI]

energization ............................... 39 A ??-dependent step precedes cargo migration away from the TatBC complex .......................................................... 41 Pre-SufI is released from TatBC complexes when membranes... are energized in the absence of TatA ........................... 42 Discussion .............................................................................................. 44 Methods...

Whitaker, Neal William 1982-

2012-12-03T23:59:59.000Z

265

E-Print Network 3.0 - anthocyanin transport proteins Sample Search...  

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

frequently and in large amounts can be transported... is expressed as KY 97,03. 12;82 Subcritical water and carbonated water extraction of anthocyanins from grape Source: Brye,...

266

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)

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.

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

2009-11-04T23:59:59.000Z

267

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

SciTech Connect (OSTI)

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.

Armstrong, S.K.

1986-01-01T23:59:59.000Z

268

STRUCTURAL REQUIREMENTS OF ORGANIC ANION TRANSPORTING POLYPEPTIDE MEDIATED TRANSPORT  

E-Print Network [OSTI]

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 ...

Weaver, Yi Miao

2010-04-12T23:59:59.000Z

269

Futile cycling at the plasma membrane: a hallmark of  

E-Print Network [OSTI]

. Transport systems catalyzing ion influx across the plasma membrane of root cells fall into two broadFutile cycling at the plasma membrane: a hallmark of low-affinity nutrient transport Dev T. Britto-affinity transport systems in the plasma membranes of root cells. In this Opinion article, we illustrate that for six

Britto, Dev T.

270

Journal of Membrane Science 239 (2004) 1726 Highly conductive ordered heterogeneous ion-exchange membranes  

E-Print Network [OSTI]

in the matrix required for reasonable ion transport through the membrane is 50­70 wt.% [2Journal of Membrane Science 239 (2004) 17­26 Highly conductive ordered heterogeneous ion-exchange membranes are used in electrodialysis (ED) as ion-selective membranes and in power sources (such as fuel

Freger, Viatcheslav "Slava"

271

Proteins  

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

Bioscience: Bioenergy, Biosecurity, and Health Proteins Protein Engineering, Structure, and Function Los Alamos scientists seek a comprehensive understanding of the structure...

272

Diffusion through Carbon Nanotube Semipermeable membranes  

SciTech Connect (OSTI)

The goal of this project is to measure transport through CNTs and study effects of confinement at molecular scale. This work is motivated by several simulation papers in high profile journals that predict significantly higher transport rates of gases and liquids through carbon nanotubes as compared with similarly-sized nanomaterials (e.g. zeolites). The predictions are based on the effects of confinement, atomically smooth pore walls and high pore density. Our work will provide the first measurements that would compare to and hopefully validate the simulations. Gas flux is predicted to be >1000X greater for SWNTs versus zeolitesi. A high flux of 6-30 H2O/NT/ns {approx} 8-40 L/min for a 1cm{sup 2} membrane is also predicted. Neutron diffraction measurements indicate existence of a 1D water chain within a cylindrical ice sheet inside carbon nanotubes, which is consistent with the predictions of the simulation. The enabling experimental platform that we are developing is a semipermeable membrane made out of vertically aligned carbon nanotubes with gaps between nanotubes filled so that the transport occurs through the nanotubes. The major challenges of this project included: (1) Growth of CNTs in the suitable vertically aligned configuration, especially the single wall carbon nanotubes; (2) Development of a process for void-free filling gaps between CNTs; and (3) Design of the experiments that will probe the small amounts of analyte that go through. Knowledge of the behavior of water upon nanometer-scale confinement is key to understanding many biological processes. For example, the protein folding process is believed to involve water confined in a hydrophobic environment. In transmembrane proteins such as aquaporins, water transport occurs under similar conditions. And in fields as far removed as oil recovery and catalysis, an understanding of the nanoscale molecular transport occurring within the nanomaterials used (e.g. zeolites) is the key to process optimization. Furthermore, advancement of many emerging nanotechnologies in chemistry and biology will undoubtedly be aided by an understanding confined water transport, particularly the details of hydrogen bonding and solvation that become crucial on this length scale. We can envision several practical applications for our devices, including desalination, gas separations, dialysis, and semipermeable fabrics for protection against CW agents etc. The single wall carbon nanotube membranes will be the key platform for applications because they will allow high transport rates of small molecules such as water and eliminate solvated ions or CW agents.

Bakajin, O

2006-02-13T23:59:59.000Z

273

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

E-Print Network [OSTI]

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.

Ernesto Gonzalez-Candela; Victor Romero-Rochin

2006-05-26T23:59:59.000Z

274

Visualization of the African swine fever virus infection in living cells by incorporation into the virus particle of green fluorescent protein-p54 membrane protein chimera  

SciTech Connect (OSTI)

Many stages of African swine fever virus infection have not yet been studied in detail. To track the behavior of African swine fever virus (ASFV) in the infected cells in real time, we produced an infectious recombinant ASFV (B54GFP-2) that expresses and incorporates into the virus particle a chimera of the p54 envelope protein fused to the enhanced green fluorescent protein (EGFP). The incorporation of the fusion protein into the virus particle was confirmed immunologically and it was determined that p54-EGFP was fully functional by confirmation that the recombinant virus made normal-sized plaques and presented similar growth curves to the wild-type virus. The tagged virus was visualized as individual fluorescent particles during the first stages of infection and allowed to visualize the infection progression in living cells through the viral life cycle by confocal microscopy. In this work, diverse potential applications of B54GFP-2 to study different aspects of ASFV infection are shown. By using this recombinant virus it was possible to determine the trajectory and speed of intracellular virus movement. Additionally, we have been able to visualize for first time the ASFV factory formation dynamics and the cytophatic effect of the virus in live infected cells. Finally, we have analyzed virus progression along the infection cycle and infected cell death as time-lapse animations.

Hernaez, Bruno [Departamento de Biotecnologia, INIA, Carretera de la Coruna Km 7, 28040 Madrid (Spain)]. E-mail: hernaez@inia.es; Escribano, Jose M. [Departamento de Biotecnologia, INIA, Carretera de la Coruna Km 7, 28040 Madrid (Spain)]. E-mail: escriban@inia.es; Alonso, Covadonga [Departamento de Biotecnologia, INIA, Carretera de la Coruna Km 7, 28040 Madrid (Spain)]. E-mail: calonso@inia.es

2006-06-20T23:59:59.000Z

275

Folding and Function of Proteorhodopsins in Photoenergy Transducing Membranes  

SciTech Connect (OSTI)

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 worlds 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.

Spudich, John L

2012-08-10T23:59:59.000Z

276

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

277

Solid-state membrane module  

DOE Patents [OSTI]

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.

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

2011-06-07T23:59:59.000Z

278

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

DOE Patents [OSTI]

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.

Ho, W. S. Winston

2012-10-02T23:59:59.000Z

279

A Role for the Membrane in Regulating Chlamydomonas Flagellar Length  

E-Print Network [OSTI]

to the old flagellar proteins? Axonemal components can be recycled to form new flagella [55] and some cilia may recycle membrane by endocytosis [42]. However, algal and mammalian cilia also shed membrane from their tips [1], [44][46] and data reported here... is shed from flagellar tips, the lack of membrane resupply may stimulate the flagellar disassembly reported here. Inhibition of secretion should affect both protein and membrane delivery to flagella. CX, a protein synthesis inhibitor, inhibits protein...

Dentler, William L., Jr

2013-01-24T23:59:59.000Z

280

Myocardial Reloading after Extracorporeal Membrane Oxygenation...  

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

Protein Synthesis. Abstract: Extracorporeal membrane oxygenation (ECMO) unloads the heart providing a bridge to recovery in children after myocardial stunning. Mortality after...

Note: This page contains sample records for the topic "membrane transport proteins" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


281

Staged membrane oxidation reactor system  

DOE Patents [OSTI]

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.

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

2012-09-11T23:59:59.000Z

282

Staged membrane oxidation reactor system  

DOE Patents [OSTI]

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.

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

2014-05-20T23:59:59.000Z

283

Staged membrane oxidation reactor system  

DOE Patents [OSTI]

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.

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

2013-04-16T23:59:59.000Z

284

Neurotransmitter Transporters  

E-Print Network [OSTI]

at specialized synaptic junctions where electrical excitability in the form of an action potential is translated membrane of neurons and glial cells. Transporters harness electrochemical gradients to force the movement.els.net #12;The response produced when a transmitter interacts with its receptors, the synaptic potential

Bergles, Dwight

285

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)

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.

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

2012-10-23T23:59:59.000Z

286

Poxvirus entry and membrane fusion  

SciTech Connect (OSTI)

The study of poxvirus entry and membrane fusion has been invigorated by new biochemical and microscopic findings that lead to the following conclusions: (1) the surface of the mature virion (MV), whether isolated from an infected cell or by disruption of the membrane wrapper of an extracellular virion, is comprised of a single lipid membrane embedded with non-glycosylated viral proteins; (2) the MV membrane fuses with the cell membrane, allowing the core to enter the cytoplasm and initiate gene expression; (3) fusion is mediated by a newly recognized group of viral protein components of the MV membrane, which are conserved in all members of the poxvirus family; (4) the latter MV entry/fusion proteins are required for cell to cell spread necessitating the disruption of the membrane wrapper of extracellular virions prior to fusion; and furthermore (5) the same group of MV entry/fusion proteins are required for virus-induced cell-cell fusion. Future research priorities include delineation of the roles of individual entry/fusion proteins and identification of cell receptors.

Moss, Bernard [Laboratory of Viral Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892-0445 (United States)]. E-mail: bmoss@nih.gov

2006-01-05T23:59:59.000Z

287

A Genomic Reappraisal of Symbiotic Function in the Aphid/Buchnera Symbiosis: Reduced Transporter Sets  

E-Print Network [OSTI]

the physiology of aphids by complementing their exclusive phloem sap diet. In this study, we reappraised, Baizongia pistaciae and Cinara cedri, using the re-annotation of their transmembrane proteins coupled, an astonishing lack of inner- membrane importers was observed. In Buchnera, the transport function has been

Paris-Sud XI, Universit de

288

Proteins  

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

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

289

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

E-Print Network [OSTI]

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

Zhu, L; Kaback, HR; Dalbey, RE

2013-01-01T23:59:59.000Z

290

A unified model of electroporation and molecular transport  

E-Print Network [OSTI]

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 ...

Smith, Kyle Christopher

2011-01-01T23:59:59.000Z

291

Production of permeable cellulose triacetate membranes  

DOE Patents [OSTI]

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.

Johnson, B.M.

1986-12-23T23:59:59.000Z

292

Production of permeable cellulose triacetate membranes  

DOE Patents [OSTI]

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.

Johnson, Bruce M. (Bend, OR)

1986-01-01T23:59:59.000Z

293

THE VITELLINE MEMBRANE OF THE UNFERTILIZED HEN'S EGG  

E-Print Network [OSTI]

membrane is charged and asymmetrical. It's directional specificity to ion transport and accompanying volumeTHE VITELLINE MEMBRANE OF THE UNFERTILIZED HEN'S EGG : ELECTROLYTE AND WATER TRANSPORT T. RYMEN J more than just the result of the membrane's ion exchange behaviour and that it may involve an enzymatic

Paris-Sud XI, Université de

294

Supporting Information for: Salt concentration differences alter membrane  

E-Print Network [OSTI]

). The membrane area available for ion transport was 11.4 cm2 . Platinum mesh electrodes that spanned the crossS1 Supporting Information for: Salt concentration differences alter membrane resistance in reverse-814-867-1847 #12;S2 Membrane resistance measurement Without a concentration difference Membrane resistance

295

Phosphatidylethanolamine mediates insertion of the catalytic domain of leader peptidase in membranes  

E-Print Network [OSTI]

: Leader peptidase; Membrane protein; Protein-lipid interaction; Protein secretion and Lipid Enzymology, Institute of Biomembranes, Utrecht University, Padualaan 8, 3584 CH Utrecht vesicles and vesicles composed of purified inner membrane lipids with comparable efficiency. It is shown

Paetzel, Mark

296

Multicomponent membranes  

DOE Patents [OSTI]

A multicomponent membrane which may be used for separating various components which are present in a fluid feed mixture comprises a mixture of a plasticizer such as a glycol and an organic polymer cast upon a porous organic polymer support. The membrane may be prepared by casting an emulsion or a solution of the plasticizer and polymer on the porous support, evaporating the solvent and recovering the membrane after curing.

Kulprathipanja, Santi (Hoffman Estates, IL); Kulkarni, Sudhir S. (Hoffman Estates, IL); Funk, Edward W. (Highland Park, IL)

1988-01-01T23:59:59.000Z

297

Genetic Analysis of Arabidopsis Mutants Impaired in Plastid Lipid Import Reveals a Role of Membrane Lipids in Chloroplast Division  

SciTech Connect (OSTI)

The biogenesis of photosynthetic membranes in plants relies largely on lipid import from the endoplasmic reticulum (ER) and this lipid transport process is mediated by TGD proteins in Arabidopsis. Such a dependency of chloroplast biogenesis on ER-to-plastid lipid transport was recently exemplified by analyzing double mutants between tgd1-1 or tgd4-3 and fad6 mutants. The fad6 mutants are defective in the desaturation of membrane lipids in chloroplasts and therefore dependent on import of polyunsaturated lipid precursors from the ER for constructing a competent thylakoid membrane system. In support of a critical role of TGD proteins in ER-to-plastid lipid trafficking, we showed that the introduction of the tgd mutations into fad6 mutant backgrounds led to drastic reductions in relative amounts of thylakoid lipids. Moreover, the tgd1-1 fad6 and tgd4-3 fad6 double mutants were deficient in polyunsaturated fatty acids in chloroplast membrane lipids, and severely compromised in the biogenesis of photosynthetic membrane systems. Here we report that these double mutants are severely impaired in chloroplast division. The possible role of membrane lipids in chloroplast division is discussed.

Fan, J.; Xu, C.

2011-03-01T23:59:59.000Z

298

E-Print Network 3.0 - apical membrane antigen Sample Search Results  

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

network (TGN) to apical membrane delivery... of newly synthesized proteins and lipids to differentiated apical and basolateral plasma membrane domains... 4KIII inhibits...

299

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:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsrucLas ConchasPassive Solar HomePromising Science for PlutoniumAbout Us / Our Programs

300

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:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear Security Administration the1 - SeptemberMicroneedles for4-16HamadaBaO/Al2O3Protecting

Note: This page contains sample records for the topic "membrane transport proteins" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


301

The Arabidopsis Chaperone J3 Regulates the Plasma Membrane H+-ATPase through Interaction with the  

E-Print Network [OSTI]

membrane H+-ATPase (PM H+-ATPase) plays an important role in the regulation of ion and metabolite transport inactivation of the PKS5 kinase. INTRODUCTION In both plants and fungi, transport across the plasma membrane constitutes a driving force for the transport of solutes and metab- olites across the plasma membrane

Deng, Xing-Wang

302

Substrate-induced changes in the structural properties of LacY  

E-Print Network [OSTI]

speed limit for protein folding measured by structure membrane protein folding membrane transport

2014-01-01T23:59:59.000Z

303

Compounds having aromatic rings and side-chain amide-functionality and a method for transporting monovalent anions across biological membranes using the same  

DOE Patents [OSTI]

A compound containing at least two aromatic rings covalently bonded together, with each aromatic ring containing at least one oxyacetamide-based side chain, the compound being capable of forming a chloride ion channel across a lipid bilayer, and transporting chloride ion across the lipid bilayer.

Davis, Jeffery T. (College Park, MD); Sidorov, Vladimir (Richmond, VA); Kotch, Frank W. (New Phila., PA)

2008-04-08T23:59:59.000Z

304

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:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear Security Administration the1 - SeptemberMicroneedlesAdvanced Photon Source The SuperpowerrelatedProteins

305

Biomolecular transport and separation in nanotubular networks.  

SciTech Connect (OSTI)

Cell membranes are dynamic substrates that achieve a diverse array of functions through multi-scale reconfigurations. We explore the morphological changes that occur upon protein interaction to model membrane systems that induce deformation of their planar structure to yield nanotube assemblies. In the two examples shown in this report we will describe the use of membrane adhesion and particle trajectory to form lipid nanotubes via mechanical stretching, and protein adsorption onto domains and the induction of membrane curvature through steric pressure. Through this work the relationship between membrane bending rigidity, protein affinity, and line tension of phase separated structures were examined and their relationship in biological membranes explored.

Stachowiak, Jeanne C.; Stevens, Mark Jackson (Sandia National Laboratories, Albuquerque, NM); Robinson, David B.; Branda, Steven S.; Zendejas, Frank; Meagher, Robert J.; Sasaki, Darryl Yoshio; Bachand, George David (Sandia National Laboratories, Albuquerque, NM); Hayden, Carl C.; Sinha, Anupama; Abate, Elisa; Wang, Julia; Carroll-Portillo, Amanda (Sandia National Laboratories, Albuquerque, NM); Liu, Haiqing (Sandia National Laboratories, Albuquerque, NM)

2010-09-01T23:59:59.000Z

306

FY08 MEMBRANE CHARACTERIZATION REPORT FOR HYBRID SULFUR ELECTROLYZER  

SciTech Connect (OSTI)

This report summarizes results from all of the membrane testing completed to date at the Savannah River National Laboratory (SRNL) for the sulfur dioxide-depolarized electrolyzer (SDE). Several types of commercially-available membranes have been analyzed for ionic resistance and sulfur dioxide transport including perfluorinated sulfonic acid (PFSA), sulfonated polyether-ketone-ketone (SPEKK), and polybenzimidazole membranes (PBI). Of these membrane types, the poly-benzimidazole membrane, Celtec-L, exhibited the best combination of characteristics for use in an SDE. Several experimental membranes have also been analyzed including hydrated sulfonated Diels-Alder polyphenylenes (SDAPP) membranes from Sandia National Laboratory, perfluorosulfonimide (PFSI) and sulfonated perfluorocyclobutyl aromatic ether (S-PFCB) prepared by Clemson University, hydrated platinum-treated PFSA prepared by Giner Electrochemical Systems (GES) and Pt-Nafion{reg_sign} 115 composites prepared at SRNL. The chemical stability, SO{sub 2} transport and ionic conductivity characteristics have been measured for several commercially available and experimental proton-conducting membranes. Commercially available PFSA membranes such as the Nafion{reg_sign} series exhibited excellent chemical stability and ionic conductivity in sulfur dioxide saturated sulfuric acid solutions. Sulfur dioxide transport in the Nafion{reg_sign} membranes varied proportionally with the thickness and equivalent weight of the membrane. Although the SO{sub 2} transport in the Nafion{reg_sign} membranes is higher than desired, the excellent chemical stability and conductivity makes this membrane the best commercially-available membrane at this time. Initial results indicated that a modified Nafion{reg_sign} membrane incorporating Pt nanoparticles exhibited significantly reduced SO{sub 2} transport. Reduced SO{sub 2} transport was also measured with commercially available PBI membrane and several experimental membranes produced at SNL and Clemson. These membranes also exhibit good chemical stability and conductivity in concentrated sulfuric acid solutions and, thus, serve as promising candidates for the SDE. Therefore, we recommend further testing of these membranes including electrolyzer testing to determine if the reduced SO{sub 2} transport eliminates the formation of sulfur-containing films at the membrane/cathode interface. SO{sub 2} transport measurements in the custom built characterization cell identified experimental limitations of the original design. During the last quarter of FY08 we redesigned and fabricated a new testing cell to overcome the previous limitations. This cell also offers the capability to test membranes under polarized conditions as well as test the performance of MEAs under selected electrolyzer conditions.

Hobbs, D; Hector Colon-Mercado, H; Mark Elvington, M

2008-09-01T23:59:59.000Z

307

Structural and Functional Proteomic Analysis of a Developing Energy Transducing Membrane  

SciTech Connect (OSTI)

While much is known about the light reactions of photosynthesis in purple bacteria, comparatively little information is available on how the requisite integral membrane proteins are assembled, their patterns of cellular localization are established or their apoproteins cooperate with numerous assembly factors in their insertion into the growing intracytoplasmic membrane (ICM). This problem was approached through a detailed structural and functional proteomic analysis of ICM assembly process in the well-characterized purple bacterium Rhodobacter sphaeroides. Proteomic approaches have focused upon identification of membrane proteins temporally expressed during ICM development and spatially localized in both membrane growth initiation sites and in mature ICM vesicles. Protocols were established for ICM induction under reduced aeration and ICM remodeling in cells adapting to low intensity illumination, which permitted isolation, in sucrose density gradients, of ICM growth initiation sites as an upper pigmented band (UPB) and mature ICM vesicles as the main (chromatophore) band. Non-denaturing clear native gel electrophoresis (CNE) of these isolated membrane fractions gave rise to pigmented bands containing the peripheral light-harvesting 2 (LH2) antenna and the reaction center-light-harvesting 1 (RC-LH1) core complex, together with a full array of other ICM proteins, which were subjected to proteomic analysis. Proteomic analysis of the gel bands from chromatophores revealed developmental changes including increasing levels of the LH2 complex as ICM development proceeded, as well as a large array of other associated proteins including high spectral counts for the F1FOâ?? ATP synthase subunits, given the inability to detect this coupling factor, as well as the more abundant cytochrome bc1 complex by atomic force microscopy (AFM). Significant levels of general membrane assembly factors were encountered, as well as high counts for RSP6124, a protein of unknown function, correlated with increasing LH2 levels. RC-LH1-containing CNE gel bands from the UPB were enriched in cytoplasmic membrane (CM) markers, including electron transfer and transport proteins, as well as general membrane assembly factors relative to chromatophore bands. This confirms the origin of the UPB from both peripheral respiratory membrane and sites of CM invagination. Significant levels of preprotein translocases YidC, YajC and SecY, bacterial type 1 signal peptidase and twin arg translocation subunit TatA were found. Such general membrane assembly factors were significantly enriched in the UPB RC-LH1 gel bands, confirming the active role of membrane invagination sites in pigment-protein complex assembly. Functional correlates of proteomics approaches were provided by near-IR fluorescence induction/relaxation transients arising from LH-BChl components. A linear relation was found between increasing functional absorption cross-section and slowing of RC electron transfer turnover rate, thought to arise from the imposition of constraints upon free UQ diffusion between the RC and cytochrome bc1 complex as the membrane became saturated with new LH2 rings. In cells undergoing ICM induction in which generation of the electrochemical proton gradient was uncoupled with CCCP, blockage in membrane insertion of the LH and RC polypetides was demonstrated. This was reflected in a diminution of quantum yield of the primary charge separation, a cessation in expansion of functional absorption cross-section and a >4-fold slowing in RC electron transfer turnover. The ICM insertion of ATP synthase and transhydrogenase was also significantly diminished. Importantly, for the UPB fraction, CCCP treatment resulted in accumulation of ~2-fold greater levels of the preprotein translocase SecY, the SecA translocation ATPase, Sec D and SecF insertion components, and chaperonins DnaJ and DnaK, suggesting that these general membrane assembly factors had accumulated in association with nascent LH and RC assembly intermediates. In addition to spectrally homogeneous bands c

Niederman, Robert A

2012-06-04T23:59:59.000Z

308

Computational prediction and analysis of protein structure  

E-Print Network [OSTI]

I, and Bowie JU. Kink prediction in membrane proteins.Los Angeles Computational prediction and analysis of proteinOF THE DISSERTATION Computational prediction and analysis of

Meruelo, Alejandro Daniel

2012-01-01T23:59:59.000Z

309

Amphiphiles for protein solubilization and stabilization  

DOE Patents [OSTI]

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.

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

2012-09-11T23:59:59.000Z

310

Amphiphiles for protein solubilization and stabilization  

DOE Patents [OSTI]

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.

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

2014-11-04T23:59:59.000Z

311

Protein kinesis: The dynamics of protein trafficking and stability  

SciTech Connect (OSTI)

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.

NONE

1995-12-31T23:59:59.000Z

312

Hybrid membrane/cryogenic separation of oxygen from air for use in the oxy-fuel process  

E-Print Network [OSTI]

and high temperature ion transport membranes. While polymeric membranes can produce oxygen enriched air of various concentrations, ion transport membranes can produce purities of close to 100%. Both membraHybrid membrane/cryogenic separation of oxygen from air for use in the oxy-fuel process Thomas

Struchtrup, Henning

313

6 Ion Transport, Osmoregulation, and  

E-Print Network [OSTI]

177 6 Ion Transport, Osmoregulation, and Acid­Base Balance W.S. Marshall and M. Grosell CONTENTS I)............................................................................182 5. Skin and Opercular Membrane..................................................................................................183 2. Sea-Water Transport Mode -- Na+,K+-ATPase and Na+,K+, 2Cl­ Co-transport

Grosell, Martin

314

The influence of oscillating electromagnetic fields on membrane structure and function: Synthetic liposome and natural membrane bilayer systems with direct application to the controlled delivery of chemical agents  

SciTech Connect (OSTI)

Investigations have been conducted to determine if an imposed electromagnetic field can influence membrane transport, and ion and drug permeability in both synthetic and natural cell membrane systems. Microwave fields enhance accumulation of sodium in the lymphocyte and induce protein shedding at Tc. Microwaves also trigger membrane permeability of liposome systems under specific field exposure conditions. Sensitivity varies in a defined way in bilayers displaying a membrane structural phase transition temperature, Tc; maximal release was observed at or near Tc. Significantly, liposome systems without a membrane phase transition were also found to experience permeability increases but, in contrast, this response was temperature independent. The above results indicate that field-enhanced drug release occurs in liposome vesicles that possess a Tc as well as non-Tc liposomes. Additional studies extend non-Tc liposome responses to the in vivo case in which microwaves trigger Gentamicin release from a liposome depot'' placed subcutaneously in the rat hind leg. In addition, evidence is provided that cell surface sequestered liposomes can be triggered by microwave fields to release drugs directly into target cells. 24 refs., 6 figs.

Liburdy, R.P.; de Manincor, D.; Fingado, B.

1989-09-01T23:59:59.000Z

315

Nucleotide-induced conformational motions and transmembrane gating dynamics in a bacterial ABC transporter  

E-Print Network [OSTI]

ATP-binding cassette (ABC) transporters are integral membrane proteins that mediate the exchange of diverse substrates across membranes powered by ATP hydrolysis. We report results of coarse-grained dynamical simulations performed for the bacterial heme transporter HmuUV. Based on the nucleotide-free structure, we have constructed a ligand-elastic-network description for this protein and investigated ATP-induced conformational motions in structurally resolved computer experiments. As we found, interactions with nucleotides resulted in generic motions which are functional and robust. Upon binding of ATP-mimicking ligands the structure changed from a conformation in which the nucleotide-binding domains formed an open shape, to a conformation in which they were found in tight contact and the transmembrane domains were rotated. The heme channel was broadened in the ligand-bound complex and the gate to the cytoplasm, which was closed in the nucleotide-free conformation, was rendered open by a mechanism that involv...

Flechsig, Holger

2014-01-01T23:59:59.000Z

316

A Novel Cl Inward-Rectifying Current in the Plasma Membrane of the Calcifying Marine Phytoplankton  

E-Print Network [OSTI]

as much as 40% of annual global carbon assimilation. Ion and nutrient transport across the plasma membrane revealed a dominant anion conductance in response to membrane hyperpolarization. Ion substitution showed conductances play an essential role in membrane voltage regulation that relates to the unique transport

Taylor, Alison

317

Neutron Reflectivity Study of Lipid Membranes Assembled on Ordered Nanocomposite and Nanoporous Silica Thin  

E-Print Network [OSTI]

moleculestrappedwithinthenanocompositethinfilmmay be used to detect trans-membrane transport (e.g., ion channel function). Furthermore, the ability in facilitating molecular transport across the membrane plane. In this regard, the use of ultrathin polymericNeutron Reflectivity Study of Lipid Membranes Assembled on Ordered Nanocomposite and Nanoporous

Parikh, Atul N.

318

Fuel cell water transport  

DOE Patents [OSTI]

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.

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

1990-01-01T23:59:59.000Z

319

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

SciTech Connect (OSTI)

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.

Rempe, Susan B.

2010-09-01T23:59:59.000Z

320

ITM Syngas and ITM H2: Engineering Development of Ceramic Membrane Reactor Systems for  

E-Print Network [OSTI]

(U.S. DOE) and other members of the ITM Syngas/ITM H2 Team, is developing Ion Transport Membrane (ITM of the ITM membrane to oxygen ions, which diffuse through the membrane under a chemical potential gradientITM Syngas and ITM H2: Engineering Development of Ceramic Membrane Reactor Systems for Converting

Note: This page contains sample records for the topic "membrane transport proteins" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


321

Mitochondrial potassium transport: the K+ Keith D. Garlid*, Petr Paucek  

E-Print Network [OSTI]

; Ion channel gating; Membrane transport; Volume regulation 1. Introduction The inner membrane. This means that ion traffic across the inner membrane will be very high. Moreover, the gradients driving saltReview Mitochondrial potassium transport: the K+ cycle Keith D. Garlid*, Petr Paucek Department

Garlid, Keith

322

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]

and stored (4C) per experiment. Three eggs were evaluated on days 0, 7, 14, 21, 28, 35, and 42 for eggs from pre-molted hens; and 1, 7, 14, 21, 28, 35, and 42 for eggs from molted hens for changes in SDS-PAGE protein banding patterns. The yolk from each...

Kelley, Angela Jean

2004-09-30T23:59:59.000Z

323

Thermodynamics and Structure of Peptide-Aggregates at Membrane Surfaces  

E-Print Network [OSTI]

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

Quake, Stephen R.

324

Identification and functional characterization of lipid binding proteins in liver and adipose tissues of Gallus domesticus  

E-Print Network [OSTI]

; whereas the second hepatic lipid transport protein is most likely liver-FABP (L-FABP). An FABP from chicken adipose cytosol (A-FABP) was purified by membrane ultrafiltration and molecular sieve chromatography. Purification was verified by SDS... via ion exchange chromatography, pH 7. 73. Purification was verified by ligand binding assays and SDS-PAGE. The first protein eluted (designated ns-LTP) had a molecular weight of approximately 14. 5 kDa and the second protein (designated L...

Sams, Gretchen Hubler

1990-01-01T23:59:59.000Z

325

Living cells are delimited by the lipid bilayer membrane, which separates an internal environment from a drastic  

E-Print Network [OSTI]

. As this region is extremely thin (around 27 ?), the membrane potential translates into an intense electric field of the cell and to harness the membrane electric field, so the embedded membrane proteins must sense changes separation across the membrane, which trans lates into a membrane potential that is on the order of ­100 m

Bezanilla, Francisco

326

Proton conducting ceramic membranes for hydrogen separation  

DOE Patents [OSTI]

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.

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

2011-09-06T23:59:59.000Z

327

Membranes for corrosive oxidations. Final CRADA report.  

SciTech Connect (OSTI)

The objective of this project is to develop porous hydrophilic membranes that are highly resistant to oxidative and corrosive conditions and to deploy them for recovery and purification of high tonnage chemicals such as hydrogen peroxide and other oxychemicals. The research team patented a process for membrane-based separation of hydrogen peroxide (US Patent No. 5,662,878). The process is based on using a hydrophilic membrane to separate hydrogen peroxide from the organic working solution. To enable this process, a new method for producing hydrophilic membrane materials (Patent No.6,464,880) was reported. We investigated methods of producing these hydrophilic materials and evaluated separations performance in comparison to membrane stability. It was determined that at the required membrane flux, membrane stability was not sufficient to design a commercial process. This work was published (Hestekin et al., J. Membrane Science 2006). To meet the performance needs of the process, we developed a membrane contactor method to extract the hydrogen peroxide, then we surveyed several commercial and pre-commercial membrane materials. We identified pre-commercial hydrophilic membranes with the required selectivity, flux, and stability to meet the needs of the process. In addition, we invented a novel reaction/separations format that greatly increases the performance of the process. To test the performance of the membranes and the new formats we procured and integrated reactor/membrane separations unit that enables controlled mixing, flow, temperature control, pressure control, and sampling. The results were used to file a US non-provisional patent application (ANL-INV 03-12). Hydrogen peroxide is widely used in pulp and paper applications, environmental treatment, and other industries. Virtually all hydrogen peroxide production is now based on a process featuring catalytic hydrogenation followed by auto-oxidation of suitable organic carrier molecules. This process has several drawbacks, particularly in the extraction phase. One general disadvantage of this technology is that hydrogen peroxide must be produced at large centralized plants where it is concentrated to 70% by distillation and transported to the users plant sites where it is diluted before use. Advanced membranes have the potential to enable more efficient, economic, and safe manufacture of hydrogen peroxide. Advanced membrane technology would allow filtration-based separation to replace the difficult liquid-liquid extraction based separation step of the hydrogen peroxide process. This would make it possible for hydrogen peroxide to be produced on-site in mini-plants at 30% concentration and used at the same plant location without distillation and transportation. As a result, production could become more cost-effective, safe and energy efficient.

Snyder, S. W.; Energy Systems

2010-02-01T23:59:59.000Z

328

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

329

E-Print Network 3.0 - anion selective membrane Sample Search...  

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

potential... Development of synthetic membrane transporters for anions ... Source: Smith, Bradley D. - Department of Chemistry and Biochemistry, University of Notre Dame...

330

Active membrane having uniform physico-chemically functionalized ion channels  

DOE Patents [OSTI]

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.

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

2012-09-24T23:59:59.000Z

331

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

E-Print Network [OSTI]

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...

Hwang, Ann

2006-10-30T23:59:59.000Z

332

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

SciTech Connect (OSTI)

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.

Way, J Douglas

2011-01-21T23:59:59.000Z

333

Membrane fluids and Dirac membrane fluids  

E-Print Network [OSTI]

There are two different methods to describe membrane (string) fluids, which use different field content. The relation between the methods is clarified by construction of combined method. Dirac membrane field appears naturally in new approach. It provides a possibility to consider new aspects of electrodynamics-type theories with electric and magnetic sources. The membrane fluid models automatically prohibit simulatenos existence of electric and magnetic currents. Possible applications to the dark energy problem are mentioned.

M. G. Ivanov

2005-05-04T23:59:59.000Z

334

Theoretical and experimental analysis of conductivity, ion diffusion and molecular transport during cell electroporation --Relation between short-lived and  

E-Print Network [OSTI]

electric field, which enables transport of molecules and ions across the cell membrane. Several and ions due to the hydrophobic nature of the lipid bilayer. Transport through the membrane occurs only for certain molecules and ions through membrane channels by means of diffusion or by active transport. However

Ljubljana, University of

335

An increasing number of synthetic compounds have been shown to facilitate ion and polar molecule transport across  

E-Print Network [OSTI]

transport of ions and polar molecules across biological membranes is essential for normal cell function synthetic transporters shown to be active in both model bilayers and cellular membranes. Mechanism of ion simulations of unassisted Na+ and Cl­ ion transport across a bilayer membrane. As the ion enters the outer

Smith, Bradley D.

336

Poisson-Nernst-Planck systems for narrow tubular-like membrane and Bixiang Wang  

E-Print Network [OSTI]

membrane channels, transport of holes and electrons in semiconductors (see, e.g., [1, 2, 24, 4, 6, 7, 8, 17, 25]). In the context of ion flow through membrane channels, it is physicallyPoisson-Nernst-Planck systems for narrow tubular-like membrane channels Weishi Liu and Bixiang Wang

Liu, Weishi

337

Electric Field Modulation of the Membrane Potential in Solid-State Ion Channels  

E-Print Network [OSTI]

channel. KEYWORDS: Nanochannel, membrane potential, electrofluidic gating, ion transport, salinityElectric Field Modulation of the Membrane Potential in Solid-State Ion Channels Weihua Guan a rapid flow of ions across the cell membrane. Normal physiological functions, such as generating action

Reed, Mark

338

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

339

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)

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.

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)

2012-03-01T23:59:59.000Z

340

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)

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.

Zlender, Vilim [Unit of Toxicology, Institute for Medical Research and Occupational Health, Zagreb (Croatia); Breljak, Davorka; Ljubojevic, Marija [Molecular Toxicology, Institute for Medical Research and Occupational Health, Ksaverska cesta 2, HR-10001, Zagreb (Croatia); Flajs, Dubravka [Unit of Toxicology, Institute for Medical Research and Occupational Health, Zagreb (Croatia); Balen, Daniela; Brzica, Hrvoje [Molecular Toxicology, Institute for Medical Research and Occupational Health, Ksaverska cesta 2, HR-10001, Zagreb (Croatia); Domijan, Ana-Marija; Peraica, Maja; Fuchs, Radovan [Unit of Toxicology, Institute for Medical Research and Occupational Health, Zagreb (Croatia); Anzai, Naohiko [Department of Pharmacology and Toxicology, Kyorin University School of Medicine, Tokyo (Japan); Sabolic, Ivan [Molecular Toxicology, Institute for Medical Research and Occupational Health, Ksaverska cesta 2, HR-10001, Zagreb (Croatia)], E-mail: sabolic@imi.hr

2009-09-15T23:59:59.000Z

Note: This page contains sample records for the topic "membrane transport proteins" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


341

Water uptake, ionic conductivity and swelling properties of anion-exchange membrane  

E-Print Network [OSTI]

occurs with negative excess volume of mixing. Percolative nature of the ion transport has been is reduced at the cathode to produce OH? , which transports through the anion-exchange membrane (AEM membrane, AEM can conduct ions only in the presence of water. In addition, water is one of the reactants

342

Journal of Membrane Science 279 (2006) 608614 Direct measurement of nanofluxes and structural relaxations of  

E-Print Network [OSTI]

of the membrane are very important in explain- ing solvent swelling [8,9]. Besides water transport, the gas. For insufficiently hydrated Nafion® membranes, the proton transport is slow, and thus, the conversion efficiency. Originally, it was argued that the gas mainly permeates either through the hydrated ionic cluster region [10

343

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 ...

344

Composite zeolite membranes  

DOE Patents [OSTI]

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.

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

2002-01-01T23:59:59.000Z

345

Hybrid adsorptive membrane reactor  

DOE Patents [OSTI]

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.

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)

2011-03-01T23:59:59.000Z

346

Supported inorganic membranes  

DOE Patents [OSTI]

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.

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

1998-01-01T23:59:59.000Z

347

Introduction Protein secretion is an essential process in prokaryotes and  

E-Print Network [OSTI]

Introduction Protein secretion is an essential process in prokaryotes and eukaryotes (Matlack et al., 1998). Protein synthesis takes place in the cytoplasm, therefore secretion requires one protein not understood. Protein translocation across biological membranes is dependent on temperature and membrane lipid

Cheng, Chi-Hing Christina

348

Method for dialysis on microchips using thin porous polymer membrane  

DOE Patents [OSTI]

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.

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

2009-05-19T23:59:59.000Z

349

Dialysis on microchips using thin porous polymer membranes  

DOE Patents [OSTI]

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.

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

2007-09-04T23:59:59.000Z

350

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

351

Composite fuel cell membranes  

SciTech Connect (OSTI)

A bilayer or trilayer composite ion exchange membrane suitable for use in a fuel cell. The composite membrane has a high equivalent weight thick layer in order to provide sufficient strength and low equivalent weight surface layers for improved electrical performance in a fuel cell. In use, the composite membrane is provided with electrode surface layers. The composite membrane can be composed of a sulfonic fluoropolymer in both core and surface layers.

Plowman, Keith R. (Lake Jackson, TX); Rehg, Timothy J. (Lake Jackson, TX); Davis, Larry W. (West Columbia, TX); Carl, William P. (Marble Falls, TX); Cisar, Alan J. (Cypress, TX); Eastland, Charles S. (West Columbia, TX)

1997-01-01T23:59:59.000Z

352

Membrane Separations Research  

E-Print Network [OSTI]

MEMBRANE SEPARATIONS RESEARCH James R. Fair Chemical Engineering Department The University of Texas at Austin Austin, TX 78712 ABSTRACT The use of membranes for separating gaseous and liquid mixtures has grown dramatically in the past 15... years. Applications have 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...

Fair, J. R.

353

Composite fuel cell membranes  

DOE Patents [OSTI]

A bilayer or trilayer composite ion exchange membrane is described suitable for use in a fuel cell. The composite membrane has a high equivalent weight thick layer in order to provide sufficient strength and low equivalent weight surface layers for improved electrical performance in a fuel cell. In use, the composite membrane is provided with electrode surface layers. The composite membrane can be composed of a sulfonic fluoropolymer in both core and surface layers.

Plowman, K.R.; Rehg, T.J.; Davis, L.W.; Carl, W.P.; Cisar, A.J.; Eastland, C.S.

1997-08-05T23:59:59.000Z

354

Characterization of the Bacteriophage Lambda Holin and Its Membrane Lesion  

E-Print Network [OSTI]

optimized in this work, has been a valuable biochemical tool for analysis and reconstitution of the pathway to S105 hole formation in the cell membrane. iv Due to the difficulty associated with over-expression and purification of toxic membrane... ...................................................................................................... 34 Part I: Protection of Holin Thiols During Protein Purification....... 34 Results ................................................................................................ 35 Discussion...

Dewey, Jill Sayes

2011-10-21T23:59:59.000Z

355

Cadmium sulfide membranes  

DOE Patents [OSTI]

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.

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

1991-10-22T23:59:59.000Z

356

Cadmium sulfide membranes  

DOE Patents [OSTI]

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.

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

1992-07-07T23:59:59.000Z

357

Meniscus Membranes For Separation  

DOE Patents [OSTI]

Gas separation membranes, especially meniscus-shaped membranes for gas separations are disclosed together with the use of such meniscus-shaped membranes for applications such as thermal gas valves, pre-concentration of a gas stream, and selective pre-screening of a gas stream. In addition, a rapid screening system for simultaneously screening polymer materials for effectiveness in gas separation is provided.

Dye, Robert C. (Irvine, CA); Jorgensen, Betty (Jemez Springs, NM); Pesiri, David R. (Aliso Viejo, CA)

2005-09-20T23:59:59.000Z

358

Meniscus membranes for separations  

DOE Patents [OSTI]

Gas separation membranes, especially meniscus-shaped membranes for gas separations are disclosed together with the use of such meniscus-shaped membranes for applications such as thermal gas valves, pre-concentration of a gas stream, and selective pre-screening of a gas stream. In addition, a rapid screening system for simultaneously screening polymer materials for effectiveness in gas separation is provided.

Dye, Robert C. (Irvine, CA); Jorgensen, Betty (Jemez Springs, NM); Pesiri, David R. (Aliso Viejo, CA)

2004-01-27T23:59:59.000Z

359

Polyphosphazene semipermeable membranes  

DOE Patents [OSTI]

A semipermeable, inorganic membrane is disclosed; the membrane is prepared from a phosphazene polymer and, by the selective substitution of the constituent groups bound to the phosphorous in the polymer structure, the selective passage of fluid from a feedstream can be controlled. Resistance to high temperatures and harsh chemical environments is observed in the use of the phosphazene polymers as semipermeable membranes.

Allen, Charles A. (Idaho Falls, ID); McCaffrey, Robert R. (Idaho Falls, ID); Cummings, Daniel G. (Idaho Falls, ID); Grey, Alan E. (Idaho Falls, ID); Jessup, Janine S. (Darlington, ID); McAtee, Richard E. (Idaho Falls, ID)

1988-01-01T23:59:59.000Z

360

EFFECT OF COMPRESSION ON CONDUCTIVITY AND MORPHOLOGY OF PFSA MEMBRANES  

SciTech Connect (OSTI)

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 membranes 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.

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

2011-07-20T23:59:59.000Z

Note: This page contains sample records for the topic "membrane transport proteins" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


361

Challenging Proteins Principles and Methods  

E-Print Network [OSTI]

.............................................................................................................................................................12 Small-scale expression screening of histidine-tagged membrane proteins from E. coli lysates Gel Filtration Principles and Methods 18-1022-18 Recombinant Protein Purification Handbook Principles and Methods 18-1142-75 Protein Purification Handbook 18-1132-29 Hydrophobic Interaction and Reversed Phase

Jacobsen, Steve

362

Enhanced membrane gas separations  

SciTech Connect (OSTI)

An improved membrane gas separation process is described comprising: (a) passing a feed gas stream to the non-permeate side of a membrane system adapted for the passage of purge gas on the permeate side thereof, and for the passage of the feed gas stream in a counter current flow pattern relative to the flow of purge gas on the permeate side thereof, said membrane system being capable of selectively permeating a fast permeating component from said feed gas, at a feed gas pressure at or above atmospheric pressure; (b) passing purge gas to the permeate side of the membrane system in counter current flow to the flow of said feed gas stream in order to facilitate carrying away of said fast permeating component from the surface of the membrane and maintaining the driving force for removal of the fast permeating component through the membrane from the feed gas stream, said permeate side of the membrane being maintained at a subatmospheric pressure within the range of from about 0.1 to about 5 psia by vacuum pump means; (c) recovering a product gas stream from the non-permeate side of the membrane; and (d) discharging purge gas and the fast permeating component that has permeated the membrane from the permeate side of the membrane, whereby the vacuum conditions maintained on the permeate side of the membrane by said vacuum pump means enhance the efficiency of the gas separation operation, thereby reducing the overall energy requirements thereof.

Prasad, R.

1993-07-13T23:59:59.000Z

363

Protein separations using porous silicon membranes  

E-Print Network [OSTI]

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... terminals located on the top surface of the etch cell. The current to be used in the experiment and the total time were previously calculated to produce the desired average pore size and porous silicon film thickness, respectively. The power source...

Pass, Shannon Marie

1992-01-01T23:59:59.000Z

364

Computational and pharmacological modeling of membrane proteins  

E-Print Network [OSTI]

Figure 35: Inhibitors of GIVA PLA 2 . 1. MAFP. 2. Efipladib.lipid binding with the GIVA PLA 2 and discovered changes inatomic-level details in the GIVA PLA 2 -Inhibitor complex.

Babakhani, Arneh

2009-01-01T23:59:59.000Z

365

A survey of integral ?-helical membrane proteins  

E-Print Network [OSTI]

in vertebrates. Annu Rev Genomics Hum Genet 6:123142 7.Evolutionary and functional genomics of the Archaea. CurrJ Struct Funct Genomics (2009) 10:269280 DOI

2009-01-01T23:59:59.000Z

366

Lipidic phase membrane protein serial femtosecond crystallography  

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

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367

Charge Inversion, Water Splitting, and Vortex Suppression Due to DNA Sorption on Ion-Selective Membranes and Their Ion-Current  

E-Print Network [OSTI]

These membranes show a unique property of selective ion transport through the nanopores of IEMs embedded to saturate at a limiting current beyond a critical cross-membrane voltage drop as a result of the ion-transport-Selective Membranes and Their Ion-Current Signatures Zdenek Slouka, Satyajyoti Senapati, Yu Yan, and Hsueh-Chia Chang

Chang, Hsueh-Chia

368

BASELINE MEMBRANE SELECTION AND CHARACTERIZATION FOR AN SDE  

SciTech Connect (OSTI)

Thermochemical processes are being developed to provide global-scale quantities of hydrogen. A variant on sulfur-based thermochemical cycles is the Hybrid Sulfur (HyS) Process which uses a sulfur dioxide depolarized electrolyzer (SDE) to produce the hydrogen. In FY05 and FY06, testing at the Savannah River National Laboratory (SRNL) explored a low temperature fuel cell design concept for the SDE. The advantages of this design concept include high electrochemical efficiency and small footprint that are crucial for successful implementation on a commercial scale. A key component of the SDE is the ion conductive membrane through which protons produced at anode migrate to the cathode and react to produce hydrogen. An ideal membrane for the SDE should have both low ionic resistivity and low sulfur dioxide transport. These features allow the electrolyzer to perform at high currents with low potentials, along with preventing contamination of both the hydrogen output and poisoning of the catalysts involved. Another key component is the electrocatalyst material used for the anode and cathode. Good electrocatalysts should be chemically stable and have a low overpotential for the desired electrochemical reactions. This report summarizes results from activities to evaluate commercial and experimental membranes for the SDE. Several different types of commercially-available membranes were analyzed for sulfur dioxide transport as a function of acid strength including perfluorinated sulfonic acid (PFSA), sulfonated poly-etherketone-ketone, and poly-benzimidazole (PBI) membranes. Experimental membranes from the sulfonated diels-alder polyphenylenes (SDAPP) and modified Nafion{reg_sign} 117 were evaluated for SO{sub 2} transport as well. These membranes exhibited reduced transport coefficient for SO{sub 2} transport without the loss in ionic conductivity. The use of Nafion{reg_sign} with EW 1100 is recommended for the present SDE testing due to the limited data regarding chemical and mechanical stability of experimental membranes. Development of new composite membranes by incorporating metal particles or by forming multilayers between PFSA membranes and hydrocarbon membranes will provide methods that will meet the SDE targets (SO{sub 2} transport reduction by a factor of 100) while decreasing catalyst layer delamination and membrane resistivity.

Colon-Mercado, H; David Hobbs, D

2007-04-03T23:59:59.000Z

369

Active Fusion and Fission Processes on a Fluid Membrane  

E-Print Network [OSTI]

We investigate the steady states and dynamical instabilities resulting from ``particles'' depositing on (fusion) and pinching off (fission) a fluid membrane. These particles could be either small lipid vesicles or isolated proteins. In the stable case, such fusion/fission events suppress long wavelength fluctuations of the membrane. In the unstable case, the membrane shoots out long tubular structures reminiscent of endosomal compartments or folded structures as in internal membranes like the endoplasmic reticulum or Golgi. We argue that these fusion/fission events should be strongly affected by tension.

Madan Rao; Sarasij R C

2001-02-26T23:59:59.000Z

370

Journal of Bioenergetics and Biomembranes, Vol. 36, No. 1, February 2004 ( C 2004) Extreme Secretion: Protein Translocation Across  

E-Print Network [OSTI]

Secretion: Protein Translocation Across the Archaeal Plasma Membrane Gabriela Ring1 and Jerry Eichler1- drophobic, lipid-based membranes. While numerous aspects of the protein translocation process have been well translocation process in vitro. KEY WORDS: Archaea; inverted membrane vesicles; protein secretion; protein

Eichler, Jerry

371

E-Print Network 3.0 - affecting protein folding Sample Search...  

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

protein folding Search Powered by Explorit Topic List Advanced Search Sample search results for: affecting protein folding Page: << < 1 2 3 4 5 > >> 1 Current status of membrane...

372

Substituted polyacetylene separation membrane  

DOE Patents [OSTI]

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.

Pinnau, I.; Morisato, Atsushi

1998-01-13T23:59:59.000Z

373

Substituted polyacetylene separation membrane  

DOE Patents [OSTI]

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.

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

1998-01-13T23:59:59.000Z

374

Nucleotide-induced conformational motions and transmembrane gating dynamics in a bacterial ABC transporter  

E-Print Network [OSTI]

ATP-binding cassette (ABC) transporters are integral membrane proteins that mediate the exchange of diverse substrates across membranes powered by ATP hydrolysis. We report results of coarse-grained dynamical simulations performed for the bacterial heme transporter HmuUV. Based on the nucleotide-free structure, we have constructed a ligand-elastic-network description for this protein and investigated ATP-induced conformational motions in structurally resolved computer experiments. As we found, interactions with nucleotides resulted in generic motions which are functional and robust. Upon binding of ATP-mimicking ligands the structure changed from a conformation in which the nucleotide-binding domains formed an open shape, to a conformation in which they were found in tight contact and the transmembrane domains were rotated. The heme channel was broadened in the ligand-bound complex and the gate to the cytoplasm, which was closed in the nucleotide-free conformation, was rendered open by a mechanism that involved tilting motions of essential transmembrane helices. Based on our findings we propose that the HmuUV transporter behaves like a `simple' mechanical device in which, induced by binding of ATP ligands, linear motions of the nucleotide-binding domains are translated into rotational motions and internal tilting dynamics of the transmembrane domains that control gating inside the heme pathway.

Holger Flechsig

2014-02-07T23:59:59.000Z

375

Polyarylether composition and membrane  

DOE Patents [OSTI]

A composition including a polyarylether copolymer is provided. The copolymer includes a polyarylether backbone; and a sulfonated oligomeric group bonded to the polyarylether suitable for use as a cation conducting membrane. Method of bonding a sulfonated oligomeric group to the polyarylether backbone to form a polyarylether copolymer. The membrane may be formed from the polyarylether copolymer composition. The chain length of the sulfonated oligomeric group may be controlled to affect or control the ion conductivity of the membrane.

Hung, Joyce (Auburn, AL); Brunelle, Daniel Joseph (Burnt Hills, NY); Harmon, Marianne Elisabeth (Redondo Beach, CA); Moore, David Roger (Albany, NY); Stone, Joshua James (Worcester, NY); Zhou, Hongyi (Niskayuna, NY); Suriano, Joseph Anthony (Clifton Park, NY)

2010-11-09T23:59:59.000Z

376

Siloxane-grafted membranes  

DOE Patents [OSTI]

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.

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

1989-10-31T23:59:59.000Z

377

Anion exchange membrane  

DOE Patents [OSTI]

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.

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

2013-05-07T23:59:59.000Z

378

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

SciTech Connect (OSTI)

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.

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

2009-11-11T23:59:59.000Z

379

Method for voltage-gated protein fractionation  

DOE Patents [OSTI]

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.

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

2012-04-24T23:59:59.000Z

380

Sandia National Laboratories: Cellular Membrane Bending by Protein-Protein  

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

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Note: This page contains sample records for the topic "membrane transport proteins" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


381

Integrated Ceramic Membrane System for Hydrogen Production  

SciTech Connect (OSTI)

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 900C, and 2) Sequential OTM and HTM reactors in this configuration, the HTM was assumed to be a Pd alloy operating at less than 600C. 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.

Schwartz, Joseph; Lim, Hankwon; Drnevich, Raymond

2010-08-05T23:59:59.000Z

382

Effective zero-thickness model for a conductive membrane driven by an electric field Falko Ziebert,1  

E-Print Network [OSTI]

membrane models is that they do not describe electrostatic effects associated with ion transport in details cells. A membrane can be driven out of equilibrium in many ways, for instance by ion concentration. The generation of ion con- centration gradients by internal means is controlled in bio- logical cells by membrane

Bazant, Martin Z.

383

Membrane module assembly  

DOE Patents [OSTI]

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.

Kaschemekat, J.

1994-03-15T23:59:59.000Z

384

Microporous alumina ceramic membranes  

DOE Patents [OSTI]

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.

Anderson, M.A.; Guangyao Sheng.

1993-05-04T23:59:59.000Z

385

Novel, Ceramic Membrane System For Hydrogen Separation  

SciTech Connect (OSTI)

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.

Elangovan, S.

2012-12-31T23:59:59.000Z

386

J. Membrane Biol. 4,179-192 (1971) 9 by Springer-Verlag New York Inc. 1971  

E-Print Network [OSTI]

antibiotics increase the ion permeability of biological membranes have been carried out on artificial model the possibility that they may serve as model systems for active transport across biological membranes. Moore and Pressman (1964) discovered the influence of valinomycin on the ion transport across the mitochondrial

Junge, Wolfgang

387

E-Print Network 3.0 - anion transporter sat1 Sample Search Results  

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

(ClC) family... in the complex network of membrane transport and solute fluxes. We used a reverse genetics approach with T Source: Groningen, Rijksuniversiteit - Centre for...

388

E-Print Network 3.0 - anion transporters oat1 Sample Search Results  

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

(ClC) family... in the complex network of membrane transport and solute fluxes. We used a reverse genetics approach with T Source: Groningen, Rijksuniversiteit - Centre for...

389

Transportation Services  

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

Transportation Services Transporting nuclear materials within the United States and throughout the world is a complicated and sometimes highly controversial effort requiring...

390

Local Transportation  

E-Print Network [OSTI]

Local Transportation. Transportation from the Airport to Hotel. There are two types of taxi companies that operate at the airport: special and regular taxis (

391

Greening Transportation  

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

Transportation Goal 2: Greening Transportation LANL supports and encourages employees to reduce their personal greenhouse gas emissions by offering various commuting and work...

392

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

SciTech Connect (OSTI)

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.

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

2008-11-01T23:59:59.000Z

393

Original article Flat ceramic membranes  

E-Print Network [OSTI]

membranes. The orig- inal intellectual concept is protected by two international patents. Strategically of investment and functioning costs while keeping the interest of ceramics. ceramic membrane / plate / tubular

Paris-Sud XI, Université de

394

Chamber transport  

SciTech Connect (OSTI)

Heavy ion beam transport through the containment chamber plays a crucial role in all heavy ion fusion (HIF) scenarios. Here, several parameters are used to characterize the operating space for HIF beams; transport modes are assessed in relation to evolving target/accelerator requirements; results of recent relevant experiments and simulations of HIF transport are summarized; and relevant instabilities are reviewed. All transport options still exist, including (1) vacuum ballistic transport, (2) neutralized ballistic transport, and (3) channel-like transport. Presently, the European HIF program favors vacuum ballistic transport, while the US HIF program favors neutralized ballistic transport with channel-like transport as an alternate approach. Further transport research is needed to clearly guide selection of the most attractive, integrated HIF system.

OLSON,CRAIG L.

2000-05-17T23:59:59.000Z

395

Catalytic nanoporous membranes  

DOE Patents [OSTI]

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.

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

2013-08-27T23:59:59.000Z

396

Solution NMR Structure of Photosystem II Reaction Center Protein...  

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

is initiated by photosystem II (PSII) in the thylakoid membranes of plants, algae and cyanobacteria. PSII is a multi-subunit pigment-protein complex responsible for...

397

Cyclic membrane separation process  

DOE Patents [OSTI]

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.

Bowser, John

2004-04-13T23:59:59.000Z

398

Cyclic membrane separation process  

DOE Patents [OSTI]

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.

Nemser, Stuart M.

2005-05-03T23:59:59.000Z

399

Composite metal membrane  

DOE Patents [OSTI]

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.

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

1998-01-01T23:59:59.000Z

400

Composite metal membrane  

DOE Patents [OSTI]

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.

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

1998-04-14T23:59:59.000Z

Note: This page contains sample records for the topic "membrane transport proteins" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


401

Rotating bubble membrane radiator  

DOE Patents [OSTI]

A heat radiator useful for expelling waste heat from a power generating system aboard a space vehicle is disclosed. Liquid to be cooled is passed to the interior of a rotating bubble membrane radiator, where it is sprayed into the interior of the bubble. Liquid impacting upon the interior surface of the bubble is cooled and the heat radiated from the outer surface of the membrane. Cooled liquid is collected by the action of centrifical force about the equator of the rotating membrane and returned to the power system. Details regarding a complete space power system employing the radiator are given.

Webb, Brent J. (West Richland, WA); Coomes, Edmund P. (West Richland, WA)

1988-12-06T23:59:59.000Z

402

Nagarajan Vaidehi and Judith Klein-Seetharaman (eds.), Membrane Protein Structure and Dynamics: Methods and Protocols, Methods in Molecular Biology, vol. 914, DOI 10.1007/978-1-62703-023-6_14, Springer Science+Business Media, LLC 2012  

E-Print Network [OSTI]

, peptides, lipids, nucleotides, and proteins) modulate GPCR activity to affect regulation of essential physiological processes (e.g., neurotransmission, cellular metabolism, secretion, cell growth, immune defense

Goddard III, William A.

403

Wrinkling in polygonal membranes  

E-Print Network [OSTI]

boundary conditions of the polygons. When pressurised, the polygonal membranes naturally reach a parabolic shape towards their centre, the extent of which varies greatly depending on a large number of parameters, including most particularly pre...

Bonin, Arnaud Stephane

2012-02-07T23:59:59.000Z

404

Gas Separation Using Membranes  

E-Print Network [OSTI]

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...

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

1984-01-01T23:59:59.000Z

405

Membrane separation of hydrocarbons  

DOE Patents [OSTI]

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.

Funk, Edward W. (Highland Park, IL); Kulkarni, Sudhir S. (Hoffman Estates, IL); Chang, Y. Alice (Des Plaines, IL)

1986-01-01T23:59:59.000Z

406

Membrane reference electrode  

DOE Patents [OSTI]

A reference electrode utilizes a small thin, flat membrane of a highly conductive glass placed on a small diameter insulator tube having a reference material inside in contact with an internal voltage lead. When the sensor is placed in a non-aqueous ionic electrolytic solution, the concentration difference across the glass membrane generates a low voltage signal in precise relationship to the concentration of the species to be measured, with high spatial resolution. 2 figs.

Redey, L.; Bloom, I.D.

1988-01-21T23:59:59.000Z

407

Battery utilizing ceramic membranes  

DOE Patents [OSTI]

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.

Yahnke, Mark S. (Berkeley, CA); Shlomo, Golan (Haifa, IL); Anderson, Marc A. (Madison, WI)

1994-01-01T23:59:59.000Z

408

Microprobes aluminosilicate ceramic membranes  

DOE Patents [OSTI]

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.

Anderson, Marc A. (2114 Chadbourne Ave., Madison, WI 53705); Sheng, Guangyao (45 N. Orchard St., Madison, WI 53715)

1993-01-01T23:59:59.000Z

409

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.

410

Direct numerical simulation of electroconvective instability and hysteretic current-voltage response of a permselective membrane  

E-Print Network [OSTI]

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 ...

Pham, Van Sang

411

Free-standing graphene membranes on glass nanopores for ionic current measurements  

E-Print Network [OSTI]

A method is established to reliably suspend graphene monolayers across glass nanopores as a simple, low cost platform to study ionic transport through graphene membranes. We systematically show that the graphene seals glass nanopore openings...

Walker, Michael I.; Weatherup, Robert S.; Bell, Nicholas A. W.; Hofmann, Stephan; Keyser, Ulrich F.

2015-01-16T23:59:59.000Z

412

Sequestration and Transport of Lignin Monomeric Precursors  

SciTech Connect (OSTI)

Lignin is the second most abundant terrestrial biopolymer after cellulose. It is essential for the viability of vascular plants. Lignin precursors, the monolignols, are synthesized within the cytosol of the cell. Thereafter, these monomeric precursors are exported into the cell wall, where they are polymerized and integrated into the wall matrix. Accordingly, transport of monolignols across cell membranes is a critical step affecting deposition of lignin in the secondarily thickened cell wall. While the biosynthesis of monolignols is relatively well understood, our knowledge of sequestration and transport of these monomers is sketchy. In this article, we review different hypotheses on monolignol transport and summarize the recent progresses toward the understanding of the molecular mechanisms underlying monolignol sequestration and transport across membranes. Deciphering molecular mechanisms for lignin precursor transport will support a better biotechnological solution to manipulate plant lignification for more efficient agricultural and industrial applications of cell wall biomass.

Liu, C.J.; Miao, Y.-C.; Zhang, K.-W.

2011-01-18T23:59:59.000Z

413

Inorganic membranes: The new industrial revolution  

SciTech Connect (OSTI)

Separation systems are a vital part of most industrial processes. These systems account for a large fraction of the capital equipment used and the operating costs of industrial processes. Inorganic membranes have the potential for providing separation systems that can significantly reduce both the capital equipment and operating costs. These separation processes include waste management and recycle as well as the primary production of raw materials and products. The authors are rapidly learning to understand the effect of physical and chemical properties on the different transport mechanisms that occur in inorganic membranes. Such understanding can be expected to provide the information needed to design, engineer and manufacture inorganic membranes to produce very high separation factors for almost any separation function. To implement such a revolution, the authors need to organize a unique partnership between the national laboratories, and industry. The university can provide research to understand the materials and transport mechanisms that produce various separations, the national laboratories the development of an economical fabrication and manufacturing capability, and industry the practical understanding of the operational problems required to achieve inplementation.

Fain, D.E. [Martin Merietta Energy Systems, Oak Ridge, TN (United States)

1994-12-31T23:59:59.000Z

414

Structural basis for solute transport, nucleotide regulation, and immunological recognition of Neisseria meningitidis PorB  

SciTech Connect (OSTI)

PorB is the second most prevalent outer membrane protein in Neisseria meningitidis. PorB is required for neisserial pathogenesis and can elicit a Toll-like receptor mediated host immune response. Here, the x-ray crystal structure of PorB has been determined to 2.3 {angstrom} resolution. Structural analysis and cocrystallization studies identify three putative solute translocation pathways through the channel pore: One pathway transports anions nonselectively, one transports cations nonselectively, and one facilitates the specific uptake of sugars. During infection, PorB likely binds host mitochondrial ATP, and cocrystallization with the ATP analog AMP-PNP suggests that binding of nucleotides regulates these translocation pathways both by partial occlusion of the pore and by restricting the motion of a putative voltage gating loop. PorB is located on the surface of N. meningitidis and can be recognized by receptors of the host innate immune system. Features of PorB suggest that Toll-like receptor mediated recognition outer membrane proteins may be initiated with a nonspecific electrostatic attraction.

Tanabe, Mikio; Nimigean, Crina M.; Iverson, T.M. (Weill-Med); (Vanderbilt)

2010-06-25T23:59:59.000Z

415

Interpenetrating polymer network ion exchange membranes and method for preparing same  

DOE Patents [OSTI]

Interpenetrating polymer network ion exchange membranes include a microporous polymeric support film interpenetrated by an ion exchange polymer and are produced by absorbing and polymerizing monomers within the support film. The ion exchange polymer provides ion exchange ligands at the surface of and throughout the support film which have sufficient ligand mobility to extract and transport ions across the membrane.

Alexandratos, Spiro D. (Knoxville, TN); Danesi, Pier R. (Vienna, AT); Horwitz, E. Philip (Naperville, IL)

1989-01-01T23:59:59.000Z

416

Multi-block sulfonated poly(phenylene) copolymer proton exchange membranes  

DOE Patents [OSTI]

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.

Fujimoto, Cy H. (Albuquerque, NM); Hibbs, Michael (Albuquerque, NM); Ambrosini, Andrea (Albuquerque, NM)

2012-02-07T23:59:59.000Z

417

Power-law scaling in protein synthesis of a stochastic regulon  

E-Print Network [OSTI]

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.

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

2008-08-07T23:59:59.000Z

418

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)

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 200500 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 450F 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.

Schlasner, Steven

2012-03-01T23:59:59.000Z

419

E-Print Network 3.0 - abc transporter homology Sample Search...  

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

KELLY1... Francisco, CA 94158, USA. ABC transporter proteins couple the energy of ATP binding and hydrolysis... known ABC transporters in diseases such as cystic fibrosis...

420

Hydrogen separation membranes annual report for FY 2006.  

SciTech Connect (OSTI)

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.

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.

2007-02-05T23:59:59.000Z

Note: This page contains sample records for the topic "membrane transport proteins" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


421

CENTRIFUGAL MEMBRANE FILTRATION  

SciTech Connect (OSTI)

SpinTek Membrane Systems, Inc., the developer of a centrifugal membrane filtration technology, has engineered and developed a system for use within the U.S. Department of Energy (DOE) Environmental Management (EM) Program. The technology uses supported microporous membranes rotating at high rpm, under pressure, to separate suspended and colloidal solids from liquid streams, yielding a solids-free permeate stream and a highly concentrated solids stream. This is a crosscutting technology that falls under the Efficient Separations and Processing Crosscutting Program, with potential application to tank wastes, contaminated groundwater, landfill leachate, and secondary liquid waste streams from other remediation processes, including decontamination and decommissioning systems. SpinTek II High Shear Rotary Membrane Filtration System is a unique compact crossflow membrane system that has large, demonstrable advantages in performance and cost compared to currently available systems: (1) High fluid shear prevents membrane fouling even with very high solids content; hazardous and radioactive components can be concentrated to the consistency of a pasty slurry without fouling. (2) Induced turbulence and shear across the membrane increases membrane flux by a factor of ten over existing systems and allows operation on fluids not otherwise treatable. (3) Innovative ceramic membrane and mechanical sealing technology eliminates compatibility problems with aggressive DOE waste streams. (4) System design allows rapid, simple disassembly for inspection or complete decontamination. (5) Produces colloidal- and suspended-solids-free filtrate without the addition of chemicals. The first phase of this project (PRDA maturity stage 5) completed the physical scale-up of the SpinTek unit and verified successful scale-up with surrogate materials. Given successful scale-up and DOE concurrence, the second phase of this project (PRDA maturity stage 6) will provide for the installation and operation of the full-scale two-stage SpinTek unit for treatment of a DOE waste-stream at the Los Alamos National Laboratory. This technology has very broad application across the DOE system. Nineteen DOE technical needs areas (Appendix C) have been identified. Following successful full-scale demonstration for treatment of DOE wastes, this innovative technology will be rapidly deployed on a wide range of waste and process streams throughout the DOE system.

William A. Greene; Patricia A. Kirk; Richard Hayes; Joshua Riley

2005-10-28T23:59:59.000Z

422

Development of novel active transport membrande devices  

SciTech Connect (OSTI)

Air Products has undertaken a research program to fabricate and evaluate gas separation membranes based upon promising ``active-transport`` (AT) materials recently developed in our laboratories. Active Transport materials are ionic polymers and molten salts which undergo reversible interaction or reaction with ammonia and carbon dioxide. The materials are useful for separating these gases from mixtures with hydrogen. Moreover, AT membranes have the unique property of possessing high permeability towards ammnonia and carbon dioxide but low permeability towards hydrogen and can thus be used to permeate these components from a gas stream while retaining hydrogen at high pressure.

Laciak, D.V.

1994-11-01T23:59:59.000Z

423

Battery utilizing ceramic membranes  

DOE Patents [OSTI]

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.

Yahnke, M.S.; Shlomo, G.; Anderson, M.A.

1994-08-30T23:59:59.000Z

424

Supported microporous ceramic membranes  

DOE Patents [OSTI]

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.

Webster, Elizabeth (Madison, WI); Anderson, Marc (Madison, WI)

1993-01-01T23:59:59.000Z

425

Supported microporous ceramic membranes  

DOE Patents [OSTI]

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.

Webster, E.; Anderson, M.

1993-12-14T23:59:59.000Z

426

Separation of Olefin/Paraffin Mixtures with Carrier Facilitated Membrane Final Report  

SciTech Connect (OSTI)

This document describes the results of a DOE funded joint effort of Membrane Technology and Research Inc. (MTR), SRI International (SRI), and ABB Lummus (ABB) to develop facilitated transport membranes for olefin/paraffin separations. Currently, olefin/paraffin separation is done by distillationan extremely energy-intensive process because of the low relative volatilities of olefins and paraffins. If facilitated transport membranes could be successfully commercialized, the potential energy savings achievable with this membrane technology are estimated to be 48 trillion Btu per year by the year 2020. We discovered in this work that silver salt-based facilitated transport membranes are not stable even in the presence of ideal olefin/paraffin mixtures. This decline in membrane performance appears to be caused by a previously unrecognized phenomenon that we have named olefin conditioning. As the name implies, this mechanism of performance degradation becomes operative once a membrane starts permeating olefins. This project is the first study to identify olefin conditioning as a significant factor impacting the performance of facilitated olefin transport membranes. To date, we have not identified an effective strategy to mitigate the impact of olefin conditioning. other than running at low temperatures or with low olefin feed pressures. In our opinion, this issue must be addressed before further development of facilitated olefin transport membranes can proceed. In addition to olefin conditioning, traditional carrier poisoning challenges must also be overcome. Light, hydrogen, hydrogen sulfide, and acetylene exposure adversely affect membrane performance through unwanted reaction with silver ions. Harsh poisoning tests with these species showed useful membrane lifetimes of only one week. These tests demonstrate a need to improve the stability of the olefin complexing agent to develop membranes with lifetimes satisfactory for commercial application. A successful effort to improve membrane coating solution stability resulted in the finding that membrane performance loss could be reversed for all poisoning cases except hydrogen sulfide exposure. This discovery offers the potential to extend membrane lifetime through cyclic regeneration. We also found that certain mixed carriers exhibited greater stability in reducing environments than exhibited by silver salt alone. These results offer promise that solutions to deal with carrier poisoning are possible. The main achievement of this program was the progress made in gaining a more complete understanding of the membrane stability challenges faced in the use of facilitated olefin transport membranes. Our systematic study of facilitated olefin transport uncovered the full extent of the stability challenge, including the first known identification of olefin conditioning and its impact on membrane development. We believe that significant additional fundamental research is required before facilitated olefin transport membranes are ready for industrial implementation. The best-case scenario for further development of this technology would be identification of a novel carrier that is intrinsically more stable than silver ions. If the stability problems could be largely circumvented by development of a new carrier, it would provide a clear breakthrough toward finally recognizing the potential of facilitated olefin transport. However, even if such a carrier is identified, additional development will be required to insure that the membrane matrix is a benign host for the olefin-carrier complexation reaction and shows good long-term stability.

Merkel, T.C.; Blanc, R.; Zeid, J.; Suwarlim, A.; Firat, B.; Wijmans, H.; Asaro, M. (SRI); Greene, M. (Lummus)

2007-03-12T23:59:59.000Z

427

Advanced Materials for Proton Exchange Membranes | Department...  

Broader source: Energy.gov (indexed) [DOE]

Advanced Materials for Proton Exchange Membranes Advanced Materials for Proton Exchange Membranes A presentation to the High Temperature Membranes Working Group meeting, May 19,...

428

Colloidal fouling of reverse osmosis membranes  

E-Print Network [OSTI]

the rate of fouling of reverse osmosis membranes treating32, 127-135. fouling of reverse osmosis membranes." Buros,Colloidal fouling of reverse osmosis membranes." J. Colloid

Elimelech, Menachem

1994-01-01T23:59:59.000Z

429

Membrane separation systems---A research and development needs assessment  

SciTech Connect (OSTI)

Membrane based separation technology, a relative newcomer on the separations scene, has demonstrated the potential of saving enormous amounts of energy in the processing industries if substituted for conventional separation systems. Over 1 quad annually, out of 2.6, can possibly be saved in liquid-to-gas separations, alone, if membrane separation systems gain wider acceptance, according to a recent DOE/OIP (DOE/NBM-80027730 (1986)) study. In recent years great strides have been made in the field and offer even greater energy savings in the future when substituted for other conventional separation techniques such as distillation, evaporation, filtration, sedimentation, and absorption. An assessment was conducted by a group of six internationally known membrane separations experts who examined the worldwide status of research in the seven major membrane areas. This encompassed four mature technology areas: reverse osmosis, micorfiltration, ultrafiltration, and electrodialysis; two developing areas: gas separation and and pervaporation; and one emerging technology: facilitated transport. Particular attention was paid to identifying the innovative processes currently emerging, and even further improvements which could gain wider acceptance for the more mature membrane technology. The topics that were pointed out as having the greatest research emphasis are pervaporation for organic-organic separations; gas separation; micorfiltration; an oxidant-resistant reverse osmosis membrane; and a fouling-resistant ultrafiltration membrane. 35 refs., 6 figs., 22 tabs.

Baker, R.W. (Membrane Technology and Research, Inc., Menlo Park, CA (USA)); Cussler, E.L. (Minnesota Univ., Minneapolis, MN (USA). Dept. of Chemical Engineering and Materials Science); Eykamp, W. (California Univ., Berkeley, CA (USA)); Koros, W.J. (Texas Univ., Austin, TX (USA)); Riley, R.L. (Separation Systems Technology, San Diego, CA (USA)); Strathmann, H. (Fraunhofer-Institut fuer Grenzflaech

1990-03-01T23:59:59.000Z

430

Prion protein in health and disease  

E-Print Network [OSTI]

The prion protein (PrP) is a conserved glycoprotein tethered to cell membranes by a glycosylphosphatidylinositol anchor. In mammals, PrP is expressed in many tissues, most abundantly in brain, heart, and muscle. Importantly, ...

Steele, Andrew D., Ph. D. Massachusetts Institute of Technology

2008-01-01T23:59:59.000Z

431

Hydrogen-selective membrane  

DOE Patents [OSTI]

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.

Collins, J.P.; Way, J.D.

1995-09-19T23:59:59.000Z

432

Hydrogen production by water dissociation using ceramic membranes - annual report for FY 2010.  

SciTech Connect (OSTI)

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.

Balachandran, U.; Dorris, S. E.; Emerson, J. E.; Lee, T. H.; Lu, Y.; Park, C. Y.; Picciolo, J. J. (Energy Systems)

2011-03-14T23:59:59.000Z

433

Hydrogen production by water dissociation using ceramic membranes - annual report for FY 2008.  

SciTech Connect (OSTI)

The objective of this project is to develop dense ceramic membranes that, without using an external power supply or circuitry, can produce hydrogen via coal/coal gas-assisted water dissociation. 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 by means of 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.

Balachandran, U.; Dorris, S. E.; Emerson, J. E.; Lee, T. H.; Lu, Y.; Park, C. Y.; Picciolo, J. J.; Energy Systems

2009-03-25T23:59:59.000Z

434

Membrane Scientist Los Angeles, CA  

E-Print Network [OSTI]

and working hands on to ensure quality and commercial viability of reverse osmosis products including hand cast and commercial reverse osmosis membrane testing and synthesis, prototype membrane testing and new

Alpay, S. Pamir

435

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

436

Functional analysis of the Arabidopsis PHT4 family of intracellular phosphate transporters  

E-Print Network [OSTI]

from genetic and biochemical studies. The Arabidopsis thaliana genome encodes a family of six proteins that share similarity with SLC17/type I Pi transporters, a diverse group of animal proteins involved in the transport of Pi, organic anions...

Guo, Biwei

2009-05-15T23:59:59.000Z

437

Phosphorylation of Photosystem II Controls Functional Macroscopic Folding of Photosynthetic Membranes  

E-Print Network [OSTI]

mobility of membrane proteins and sustained photosynthetic activity. The use of captured sunlight energy, Linko ping University, SE-581 85 Linko ping, Sweden b Departments of Molecular Biology and Plant contain highly folded membrane layers enriched in photosystem II, which uses light energy to oxidize water

Halazonetis, Thanos

438

Integration of Dialysis Membranes into a Poly(dimethylsiloxane) Microfluidic Chip for  

E-Print Network [OSTI]

Integration of Dialysis Membranes into a Poly(dimethylsiloxane) Microfluidic Chip for Isoelectric(dimethylsiloxane) microfluidic chip-based car- tridge is developed and reported here for protein analysis using isoelectic of dialysis membranes into a microfluidic chip significantly improves IEF repeat- ability by eliminating

Le Roy, Robert J.

439

Structure and Dynamics of Cholesterol-Containing Polyunsaturated Lipid Membranes Studied by Neutron  

E-Print Network [OSTI]

and peripheral membrane proteins. The complexity of structural and functional phenomena in cell membranes from x-3 fatty acid precursors such as a-linolenic acid (18:2n3, ALA). The lack of DHA or its x-3 fatty acid precursors in the diet, in particular during periods of rapid brain development, has been

White, Stephen

440

Understanding external forces acting on cells control lipid membrane structure and dynamics  

E-Print Network [OSTI]

Understanding external forces acting on cells control lipid membrane structure and dynamics Overview: Plasma membranes composed of a variety of lipids and proteins are complex and dynamic structures optical microscopy. Much of the molecular insights into the structure and dynamics of these structures has

Bjrnstad, Ottar Nordal

Note: This page contains sample records for the topic "membrane transport proteins" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


441

Journal of Membrane Science 330 (2009) 388398 Contents lists available at ScienceDirect  

E-Print Network [OSTI]

for the coupled heat and mass transport through a zeolite membrane are derived from the framework of non polarization is, to a large extent, a surface effect. The heat flux induces an extra driving force for mass at the interfaces, revealing the mass transport across the interfaces is governed by the coupling with the heat flux

Kjelstrup, Signe

2009-01-01T23:59:59.000Z

442

Recycling of used perfluorosulfonic acid membranes  

DOE Patents [OSTI]

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.

Grot, Stephen (Middletown, DE); Grot, Walther (Chadds Ford, PA)

2007-08-14T23:59:59.000Z

443

Poly(vinyl alcohol)-based buffering membranes for isoelectric trapping separations  

E-Print Network [OSTI]

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...

Craver, Helen C.

2009-05-15T23:59:59.000Z

444

Measuring material properties of tectorial membranes from normal and genetically modified mice  

E-Print Network [OSTI]

With the discovery of hearing disorders caused by mutations in proteins expressed in the tectorial membrane (TM), the importance of the TM in cochlear mechanics has never been clearer. However, the exact role of the TM in ...

Masaki, Kinuko

2006-01-01T23:59:59.000Z

445

Myosin IIA participates in docking of Glut4 storage vesicles with the plasma membrane in 3T3-L1 adipocytes  

SciTech Connect (OSTI)

In adipocytes and myocytes, insulin stimulation translocates glucose transporter 4 (Glut4) storage vesicles (GSVs) from their intracellular storage sites to the plasma membrane (PM) where they dock with the PM. Then, Glut4 is inserted into the PM and initiates glucose uptake into these cells. Previous studies using chemical inhibitors demonstrated that myosin II participates in fusion of GSVs and the PM and increase in the intrinsic activity of Glut4. In this study, the effect of myosin IIA on GSV trafficking was examined by knocking down myosin IIA expression. Myosin IIA knockdown decreased both glucose uptake and exposures of myc-tagged Glut4 to the cell surface in insulin-stimulated cells, but did not affect insulin signal transduction. Interestingly, myosin IIA knockdown failed to decrease insulin-dependent trafficking of Glut4 to the PM. Moreover, in myosin IIA knockdown cells, insulin-stimulated binding of GSV SNARE protein, vesicle-associated membrane protein 2 (VAMP2) to PM SNARE protein, syntaxin 4 was inhibited. These data suggest that myosin IIA plays a role in insulin-stimulated docking of GSVs to the PM in 3T3-L1 adipocytes through SNARE complex formation.

Chung, Le Thi Kim, E-mail: ngocanh@nutr.med.tokushima-u.ac.jp [Department of Nutrition and Metabolism, Institute of Health Biosciences, The University of Tokushima Graduate School, 3-18-15 Kuramoto-cho, Tokushima 770-8503 (Japan); Hosaka, Toshio [Department of Public Health and Applied Nutrition, Institute of Health Biosciences, The University of Tokushima Graduate School, Tokushima (Japan)] [Department of Public Health and Applied Nutrition, Institute of Health Biosciences, The University of Tokushima Graduate School, Tokushima (Japan); Harada, Nagakatsu; Jambaldorj, Bayasgalan; Fukunaga, Keiko; Nishiwaki, Yuka [Department of Nutrition and Metabolism, Institute of Health Biosciences, The University of Tokushima Graduate School, 3-18-15 Kuramoto-cho, Tokushima 770-8503 (Japan)] [Department of Nutrition and Metabolism, Institute of Health Biosciences, The University of Tokushima Graduate School, 3-18-15 Kuramoto-cho, Tokushima 770-8503 (Japan); Teshigawara, Kiyoshi [Clinical Research Center for Diabetes, Tokushima University Hospital, 2-50-1 Kuramoto-cho, Tokushima 770-8503 (Japan)] [Clinical Research Center for Diabetes, Tokushima University Hospital, 2-50-1 Kuramoto-cho, Tokushima 770-8503 (Japan); Sakai, Tohru [Department of Public Health and Applied Nutrition, Institute of Health Biosciences, The University of Tokushima Graduate School, Tokushima (Japan)] [Department of Public Health and Applied Nutrition, Institute of Health Biosciences, The University of Tokushima Graduate School, Tokushima (Japan); Nakaya, Yutaka [Department of Nutrition and Metabolism, Institute of Health Biosciences, The University of Tokushima Graduate School, 3-18-15 Kuramoto-cho, Tokushima 770-8503 (Japan)] [Department of Nutrition and Metabolism, Institute of Health Biosciences, The University of Tokushima Graduate School, 3-18-15 Kuramoto-cho, Tokushima 770-8503 (Japan); Funaki, Makoto, E-mail: m-funaki@clin.med.tokushima-u.ac.jp [Clinical Research Center for Diabetes, Tokushima University Hospital, 2-50-1 Kuramoto-cho, Tokushima 770-8503 (Japan)] [Clinical Research Center for Diabetes, Tokushima University Hospital, 2-50-1 Kuramoto-cho, Tokushima 770-8503 (Japan)

2010-01-01T23:59:59.000Z

446

Unique battery with an active membrane separator having uniform physico-chemically functionalized ion channels and a method making the same  

DOE Patents [OSTI]

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.

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)

2012-02-21T23:59:59.000Z

447

Final Report - Membranes and MEA's for Dry, Hot Operating Conditions  

SciTech Connect (OSTI)

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.

Hamrock, Steven J.

2011-06-30T23:59:59.000Z

448

Pilot Scale Water Gas Shift - Membrane Device for Hydrogen from Coal  

SciTech Connect (OSTI)

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.

Barton, Tom

2013-06-30T23:59:59.000Z

449

Transportation Security  

Broader source: Energy.gov (indexed) [DOE]

Preliminary Draft - For Review Only 1 Transportation Security Draft Annotated Bibliography Review July 2007 Preliminary Draft - For Review Only 2 Work Plan Task * TEC STG Work...

450

Computational Transportation  

E-Print Network [OSTI]

), in-vehicle computers, and computers in the transportation infrastructure are integrated ride- sharing, real-time multi-modal routing and navigation, to autonomous/assisted driving

Illinois at Chicago, University of

451

Parallel topology of genetically fused EmrE Sonia Steiner-Mordoch1  

E-Print Network [OSTI]

: ion-coupled transport; membrane protein evolution; membrane protein structure; membrane protein for biochemical and biophysical studies of membrane-based, ion-coupled transporters due to its size, stability.emboj.7601951; Published online 6 December 2007 Subject Categories: membranes & transport; proteins Keywords

Lebendiker, Mario

452

Membrane separation of hydrocarbons  

DOE Patents [OSTI]

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.

Chang, Y. Alice (Des Plaines, IL); Kulkarni, Sudhir S. (Hoffman Estates, IL); Funk, Edward W. (Highland Park, IL)

1986-01-01T23:59:59.000Z

453

Membrane Applications at Ceramatec  

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 RankCombustion | Department of EnergyDevelopmentTechnologies | DepartmentADVISORYFinalMeltonMembrane

454

Novel Catalytic Membrane Reactors  

SciTech Connect (OSTI)

There are many industrial catalytic organic reversible reactions with amines or alcohols that have water as one of the products. Many of these reactions are homogeneously catalyzed. In all cases removal of water facilitates the reaction and produces more of the desired chemical product. By shifting the reaction to right we produce more chemical product with little or no additional capital investment. Many of these reactions can also relate to bioprocesses. Given the large number of water-organic compound separations achievable and the ability of the Compact Membrane Systems, Inc. (CMS) perfluoro membranes to withstand these harsh operating conditions, this is an ideal demonstration system for the water-of-reaction removal using a membrane reactor. Enhanced reaction synthesis is consistent with the DOE objective to lower the energy intensity of U.S. industry 25% by 2017 in accord with the Energy Policy Act of 2005 and to improve the United States manufacturing competitiveness. The objective of this program is to develop the platform technology for enhancing homogeneous catalytic chemical syntheses.

Stuart Nemser, PhD

2010-10-01T23:59:59.000Z

455

Synthesis of an un-supported, high-flow ZSM-22 zeolite membrane  

DOE Patents [OSTI]

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.

Thoma, Steven G. (Albuquerque, NM); Nenoff, Tina M. (Albuquerque, NM)

2006-10-10T23:59:59.000Z

456

Energy for Cleaner Transportation Hydro-Quebec  

E-Print Network [OSTI]

W. Yu, X. Yang, P. Wang, and L. Meng 19 Rotating Rate Dependency of Methanol Oxidation on a Smooth and Methanol Transport in Direct Methanol Proton Exchange Membrane Fuel Cells M. Lefebvre and D. Olmeijer 35 solution-based room temperature reduction technique whereby nanoscale iron powder is produced. This new

Azad, Abdul-Majeed

457

Highly Confined Photon Transport in Subwavelength Metallic Slot Waveguides  

E-Print Network [OSTI]

was deposited on one side of a free-standing Si3N4 membrane. Using focused ion- beam milling, wire waveguidesHighly Confined Photon Transport in Subwavelength Metallic Slot Waveguides J. A. Dionne,*, H. J and electronic components. Although optical interconnects exhibit a large bandwidth for signal transport, minimum

Atwater, Harry

458

Molecular Squares as Molecular Sieves: Size-Selective Transport Through  

E-Print Network [OSTI]

Molecular Squares as Molecular Sieves: Size-Selective Transport Through Porous-Membrane squaresº: cyclic structures typically featuring metal-ion cor- ners and difunctional bridging ligands processes: size-selective molecular transport from a guest-containing solution to one initially free

459

proteinsSTRUCTURE O FUNCTION O BIOINFORMATICS Role of partial protein unfolding in  

E-Print Network [OSTI]

Cl, guanidinium chloride; HX, hydrogen exchange; NMR, nuclear magnetic resonance; SEC, size exclusion- tein formulations,11 as an anesthetic,12 as a membrane fluidizer,13 as a heat shock protein inducer,14

Mallela, Krishna M. G.

460

High temperature ceramic membrane reactors for coal liquid upgrading  

SciTech Connect (OSTI)

In this project we will study a novel process concept, i.e., the use of ceramic membrane reactors in upgrading of coal model compounds and coal derived liquids. In general terms, the USC research team is responsible for constructing and operating the membrane reactor apparatus and for testing various inorganic membranes for the upgrading of coal derived asphaltenes and coal model compounds. The USC effort will involve the principal investigator of this project and two graduate research assistants. The ALCOA team is responsible for the preparation of the inorganic membranes, for construction and testing of the ceramic membrane modules, and for measurement of their transport properties. The ALCOA research effort will involve Dr. Paul K. T. Liu, who is the project manager of the ALCOA research team, an engineer and a technician. UNOCAL's contribution will be limited to overall technical assistance in catalyst preparation and the operation of the laboratory upgrading membrane reactor and for analytical back-up and expertise in oil analysis and materials characterization. UNOCAL is a no-cost contractor but will be involved in all aspects of the project, as deemed appropriate.

Tsotsis, T.T.

1992-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "membrane transport proteins" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


461

Transportation Market Distortions  

E-Print Network [OSTI]

of Highways, Volpe National Transportation Systems Center (Evaluating Criticism of Transportation Costing, VictoriaFrom Here: Evaluating Transportation Diversity, Victoria

Litman, Todd

2006-01-01T23:59:59.000Z

462

Electrical properties of polar membranes  

E-Print Network [OSTI]

Biological membranes are capacitors that can be charged by applying a field across the membrane. The charges on the capacitor exert a force on the membrane that leads to electrostriction, i.e. a thinning of the membrane. Since the force is quadratic in voltage, negative and positive voltage have an identical influence on the physics of symmetric membranes. However, this is not the case for a membrane with an asymmetry leading to a permanent electric polarization. Positive and negative voltages of identical magnitude lead to different properties. Such an asymmetry can originate from a lipid composition that is different on the two monolayers of the membrane, or from membrane curvature. The latter effect is called 'flexoelectricity'. As a consequence of permanent polarization, the membrane capacitor is discharged at a voltage different from zero. This leads to interesting electrical phenomena such as outward or inward rectification of membrane permeability. Here, we introduce a generalized theoretical framework, that treats capacitance, polarization, flexoelectricity and piezoelectricity in the same language.

Lars D. Mosgaard; Karis A. Zecchi; Thomas Heimburg

2014-11-25T23:59:59.000Z

463

Photochemical energy conversion by membrane-bound photoredox systems  

SciTech Connect (OSTI)

Most of our effort during the past grant period has been directed towards investigating electron transfer processes involving redox proteins at lipid bilayer/aqueous interfaces. This theme, as was noted in our previous three year renewal proposal, is consistent with our goal of developing biomimetic solar energy conversion systems which utilize the unique properties of biological electron transfer molecules. Thus, small redox proteins such as cytochrome c, plastocyanin and ferredoxin function is biological photosynthesis as mediators of electron flow between the photochemical systems localized in the membrane, and more complex soluble or membrane-bound redox proteins which are designed to carry out specific biological tasks such as transbilayer proton gradient formation, dinitrogen fixation, ATP synthesis, dihydrogen synthesis, generation of strong reductants, etc. In these studies, we have utilized two principal experimental techniques, laser flash photolysis and cyclic voltammetry, both of which permit direct measurements of electron transfer processes.

Tollin, G.

1992-03-01T23:59:59.000Z

464

E-Print Network 3.0 - antioxidant proteins protect Sample Search...  

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

using the total equivalent antioxidant capacity' Summary: and its protective role in acrolein- induced protein in synaptosomal membranes: relevance to brain lipid......

465

Hydrogen separation membranes annual report for FY 2010.  

SciTech Connect (OSTI)

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.

Balachandran, U.; Dorris, S. E; Emerson, J. E.; Lee, T. H.; Lu, Y.; Park, C. Y.; Picciolo, J. J. (Energy Systems)

2011-03-14T23:59:59.000Z

466

Supported liquid membrane electrochemical separators  

DOE Patents [OSTI]

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.

Pemsler, J. Paul (Lexington, MA); Dempsey, Michael D. (Revere, MA)

1986-01-01T23:59:59.000Z

467

High Temperature Membrane Working Group  

Broader source: Energy.gov (indexed) [DOE]

Using Advanced Polymeric Membranes BESP 20 Michael Heben NREL Carbon Nanotube Materials for Substrate Enhanced Control of Catalytic Activity BESP 21 G. Kane Jennings...

468

Amorphous Alloy Membranes for High Temperature Hydrogen Separation  

SciTech Connect (OSTI)

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.

Coulter, K

2013-09-30T23:59:59.000Z

469

Crystal Structure of a Potassium Ion Transporter TrkH  

SciTech Connect (OSTI)

The TrkH/TrkG/KtrB proteins mediate K{sup +} uptake in bacteria and probably evolved from simple K{sup +} channels by multiple gene duplications or fusions. Here we present the crystal structure of a TrkH from Vibrio parahaemolyticus. TrkH is a homodimer, and each protomer contains an ion permeation pathway. A selectivity filter, similar in architecture to those of K{sup +} channels but significantly shorter, is lined by backbone and side-chain oxygen atoms. Functional studies showed that TrkH is selective for permeation of K{sup +} and Rb{sup +} over smaller ions such as Na{sup +} or Li{sup +}. Immediately intracellular to the selectivity filter are an intramembrane loop and an arginine residue, both highly conserved, which constrict the permeation pathway. Substituting the arginine with an alanine significantly increases the rate of K{sup +} flux. These results reveal the molecular basis of K{sup +} selectivity and suggest a novel gating mechanism for this large and important family of membrane transport proteins.

Y Cao; X Jin; H Huang; M Getahun Derebe; E Levin; V Kabaleeswaran; Y Pan; M Punta; J Love; et al.

2011-12-31T23:59:59.000Z

470

Feed gas contaminant removal in ion transport membrane systems  

DOE Patents [OSTI]

Method for gas purification comprising (a) obtaining a feed gas stream containing one or more contaminants selected from the group consisting of volatile metal oxy-hydroxides, volatile metal oxides, and volatile silicon hydroxide; (b) contacting the feed gas stream with a reactive solid material in a guard bed and reacting at least a portion of the contaminants with the reactive solid material to form a solid reaction product in the guard bed; and (c) withdrawing from the guard bed a purified gas stream.

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

2008-09-16T23:59:59.000Z

471

Ion Transport in Nanostructured Block Copolymer/Ionic Liquid Membranes  

E-Print Network [OSTI]

14-18 fuel cells, 19-26 dye-sensitized solar cells, 27, 28batteries or dye-sensitized solar cells. 57, 58 PVdF-co-PHFP

Hoarfrost, Megan Lane

2012-01-01T23:59:59.000Z

472

anandamide membrane transporter: Topics by E-print Network  

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

and fuel (mostly methane) conversion purposes over the last three decades. The fuel ... Apo, Daniel Jolomi 2012-01-01 47 Bioenergetics and mechanical actuation analysis with...

473

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:YearRound-Up fromDepartment ofEnergy Natura