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Test Manual (Tentative) For Permselective Membranes

Description: From Introduction: "This test manual is intended to be used as an aid to persons purchasing or evaluating permselective membranes. This manual covers specified methods for testing, sampling, storing, and shipping permselective membrane materials of both cationic and anionic types."
Date: January 1964
Creator: United Stats. Bureau of Reclamation.
Partner: UNT Libraries Government Documents Department

Correlation of Structure and Function for CO2 Permeation in Polyphosphazene Membranes

Description: Thermochemical water splitting processes for generating hydrogen have been researched for at least thirty years in which over one-hundred chemical cycles have been proposed that use heat and/or electrochemistry to split water into hydrogen and oxygen. Proposed heat sources include nuclear reactors and solar reflectors. One of the most promising cycles is the Sulfur-Iodine (S-I) process, where aqueous HI is thermochemically decomposed into H2 and I2 at approximately 350 degrees Celsius. Regeneration of HI is accomplished by the Bunsen reaction (reaction of SO2, water, and iodine to generate H2SO4 and HI). Furthermore, SO2 is regenerated from the decomposition of H2SO4 at 850 degrees Celsius yielding the SO2 as well as O2. Thus, the cycle actually consists of two concurrent oxidation-reduction loops. As HI is regenerated, co-produced H2SO4 must be separated so that each may be decomposed. Current flowsheets employ a large amount (~83 mol% of the entire mixture) of elemental I2 to cause the HI and the H2SO4 to separate into two phases. Removal of water from this system has the direct result of lowering the required quantity of I2, thus reducing the amount of material that must be physically moved within and S-I plant. Recent efforts at the INL have concentrated on applying pervaporation through Nafion-117 membranes for the removal of water from HI/water and HI/Iodine/water feedstreams. In pervaporation, a feed is circulated at low pressure across the upstream side of the membrane, while a vacuum is applied downstream. Selected permeants sorb into the membrane, transport through it, and are vaporized from the backside. Thus, a concentration gradient is established, which provides the driving force for transport. In this work, membrane separations have been performed at temperatures as high as 132 degrees Celsius. Transmembrane fluxes of water are commercially competitive (~200 g/m2h) and separation factors ([HIfeed]/[HIpermeate]) have been measured ...
Date: October 1, 2005
Creator: Stewart, Frederick F. & Orme, Christopher J.
Partner: UNT Libraries Government Documents Department

Investigation of Membrane Stack Resistance Increase With a Natural Brackish Water

Description: From Introduction: "An investigation was undertaken by the Bureau of Reclamation to identify the cause of causes of this problem with a particular brackish water. The resistance increase of is of great concern principally because of the increase in power consumption that ultimately contributes to a higher cost for product water. Reports show that membrane stack resistance has increased as much as 200 percent over period of several days."
Date: January 1968
Creator: Furukawa, D. H.
Partner: UNT Libraries Government Documents Department

A New Design Concept for Reverse Osmosis Membrane Cells

Description: From Introduction: "A new concept, that of lateral permeation of product water through a porous substrate, is the basis for both the cost reduction study of plate-and-frame reverse osmosis units and the study of field replacement of membrane and is therefore the subject of the development studies encompassed by this report."
Date: May 1969
Creator: Fluke, G. A.
Partner: UNT Libraries Government Documents Department

Membranes for the Sulfur-Iodine Integrated Laboratory Scale Demonstration

Description: INL has developed polymeric membrane-based chemical separations to enable the thermochemical production of hydrogen. Major activities included studies of sulfuric acid concentration membranes, hydriodic acid concentration membranes, SO2/O2 separation membranes, potential applications of a catalyst reactor system for the decomposition of HI, and evaluation of the chemical separation needs for alternate thermochemical cycles. Membranes for the concentration of sulfuric acid were studied using pervaporation. The goal of this task was to offer the sulfur-iodine (S-I) and the hybrid sulfur (HyS) cycles a method to concentrate the sulfuric acid containing effluent from the decomposer without boiling. In this work, sulfuric acid decomposer effluent needs to be concentrated from ~50 % acid to 80 %. This task continued FY 2006 efforts to characterize water selective membranes for use in sulfuric acid concentration. In FY 2007, experiments were conducted to provide specific information, including transmembrane fluxes, separation factors, and membrane durability, necessary for proper decision making on the potential inclusion of this process into the S-I or HyS Integrated Laboratory Scale demonstration.
Date: August 1, 2007
Creator: Stewart, Frederick F.
Partner: UNT Libraries Government Documents Department

Membrane Oxygen Enrichment Cost and Application Evaluation

Description: A separation process, similar to the reverse osmosis membrane process for the desalination of water, can be used for the separation and enrichment of multi-component gas streams. The development of new processing methods and modular packing systems together with advanced commercialization of desalination systems now makes similar processes for gas separation appear feasible and economical. Composite membranes have been developed that are both thin enough to provide a large gas flow and strong enough to withstand the driving pressure of the incoming gas. This is done by depositing a polymer on the finely porous surface of a fabric-reinforced supporting membrane. The resulting material is then formed into a spiral-wound element that provides a large amount of membrane area in a small volume. Laboratory experiments using gas separation membranes by Fluid Systems Division of UOP and by General Electric Company have established the technical feasibility of using such membranes to produce oxygen-enriched air. A preliminary analysis of membrane oxygen enrichment economics was prepared by the Fluid System Division of UOP which shows that oxygen enrichment could be profitable for combustion systems up to 100 tons of oxygen per day. A supporting economic study made by Econergy Associates reaffirms the positive economic potential for a 1000-ton/day, 30% oxygen enrichment plant.
Date: March 1979
Creator: Fischer, J. & Burnett, Lowell J.
Partner: UNT Libraries Government Documents Department

Macroscopic Modeling of Polymer-Electrolyte Membranes

Description: In this chapter, the various approaches for the macroscopic modeling of transport phenomena in polymer-electrolyte membranes are discussed. This includes general background and modeling methodologies, as well as exploration of the governing equations and some membrane-related topic of interest.
Date: April 1, 2007
Creator: Weber, A.Z. & Newman, J.
Partner: UNT Libraries Government Documents Department

Modeling biomembranes.

Description: Understanding the properties and behavior of biomembranes is fundamental to many biological processes and technologies. Microdomains in biomembranes or ''lipid rafts'' are now known to be an integral part of cell signaling, vesicle formation, fusion processes, protein trafficking, and viral and toxin infection processes. Understanding how microdomains form, how they depend on membrane constituents, and how they act not only has biological implications, but also will impact Sandia's effort in development of membranes that structurally adapt to their environment in a controlled manner. To provide such understanding, we created physically-based models of biomembranes. Molecular dynamics (MD) simulations and classical density functional theory (DFT) calculations using these models were applied to phenomena such as microdomain formation, membrane fusion, pattern formation, and protein insertion. Because lipid dynamics and self-organization in membranes occur on length and time scales beyond atomistic MD, we used coarse-grained models of double tail lipid molecules that spontaneously self-assemble into bilayers. DFT provided equilibrium information on membrane structure. Experimental work was performed to further help elucidate the fundamental membrane organization principles.
Date: November 1, 2005
Creator: Plimpton, Steven James; Heffernan, Julieanne; Sasaki, Darryl Yoshio; Frischknecht, Amalie Lucile; Stevens, Mark Jackson & Frink, Laura J. Douglas
Partner: UNT Libraries Government Documents Department

Catalytic Membrane Sensors

Description: The proposed "catalytic membrane sensor" (CMS) was developed to generate a device which would selectively identify a specific reagent in a complex mixture of gases. This was to be accomplished by modifying an existing Hz sensor with a series of thin films. Through selectively sieving the desired component from a complex mixture and identifying it by decomposing it into Hz (and other by-products), a Hz sensor could then be used to detect the presence of the select component. The proposed "sandwich-type" modifications involved the deposition of a catalyst layered between two size selective sol-gel layers on a Pd/Ni resistive Hz sensor. The role of the catalyst was to convert organic materials to Hz and organic by-products. The role of the membraneo was to impart both chemical specificity by molecukir sieving of the analyte and converted product streams, as well as controlling access to the underlying Pd/Ni sensor. Ultimately, an array of these CMS elements encompassing different catalysts and membranes were to be developed which would enable improved selectivity and specificity from a compiex mixture of organic gases via pattern recognition methodologies. We have successfully generated a CMS device by a series of spin-coat deposited methods; however, it was determined that the high temperature required to activate the catalyst, destroys the sensor.
Date: December 1, 1998
Creator: Boyle, T.J.; Brinker, C.J.; Gardner, T.J.; Hughes, R.C. & Sault, A.G.
Partner: UNT Libraries Government Documents Department

Ultrastructure of Azotobacter vinelandii

Description: The purpose of this research was to reveal the morphological and cytological characteristics of Azotobacter vinelandii cells cultured in dialyzed soil medium. Culture samples taken at two, four, eight, sixteen and thirty-two days were prepared and examined with the electron microscope. Comparisons of the morphology of Azotobacter vinelandii grown in dialyzed soil medium with those grown in Burk's nitrogen-free, chemically-defined medium were done.
Date: December 1993
Creator: Chao, Ying L. (Ying Liang)
Partner: UNT Libraries

THE EFFECT OF CO ON HYDROGEN PERMEATION THROUGH PD AND INTERNALLY OXIDIZED AND UN-OXIDIZED PD ALLOY MEMBRANES

Description: The H permeation of internally oxidized Pd alloy membranes such as Pd-Al and Pd-Fe, but not Pd-Y alloys, is shown to be more resistant to inhibition by CO(g) as compared to Pd or un-oxidized Pd alloy membranes. The increased resistance to CO is found to be greater at 423 K than at 473 K or 523 K. In these experiments CO was pre-adsorbed onto the membranes and then CO-free H{sub 2} was introduced to initiate the H permeation.
Date: October 20, 2010
Creator: Shanahan, K.; Flanagan, T. & Wang, D.
Partner: UNT Libraries Government Documents Department

Development of Inorganic Membranes for Gas Separation

Description: In previous years, the annual report concentrated on the work that was performed in the immediate past year. This year, in order to emphasize the great amount of progress that has been made, we will summarize our process and present the many membranes that we fabricated with high separation factors. One of our past major problems has been the classified status of much of our fabrication process. DOE has developed a review process whereby developed membranes can be reviewed for classified information and non-proliferation risk. When a membrane passes that review process the membrane can be declared unclassified and available for commercial manufacture. Currently, we have fifteen membranes/filters approved for commercial manufacture. At present; Pall Corporation is the only company licensed to manufacture these membranes/filters.
Date: May 15, 2002
Creator: Fain, D.E.
Partner: UNT Libraries Government Documents Department

Develpment of Higher Temperature Membrane and Electrode Assembly (MEA) for Proton Exchange Membrane Fuel Cell Devices

Description: Our work will fucus on developing higher temperature MEAs based on SPEKK polymer blends. Thse MEAs will be designed to operatre at 120 degrees C Higher temperatures, up to 200 degrees C will also be explored. This project will develop Nafion-free MEAs using only SPEKK blends in both membrane and catalytic layers.
Date: December 30, 2005
Creator: Susan Agro, Anthony DeCarmine, Shari Williams
Partner: UNT Libraries Government Documents Department

Use of ceragenins to create novel biofouling resistant water-treatment membranes.

Description: Scoping studies have demonstrated that ceragenins, when linked to water-treatment membranes have the potential to create biofouling resistant water-treatment membranes. Ceragenins are synthetically produced molecules that mimic antimicrobial peptides. Evidence includes measurements of CSA-13 prohibiting the growth of and killing planktonic Pseudomonas fluorescens. In addition, imaging of biofilms that were in contact of a ceragenin showed more dead cells relative to live cells than in a biofilm that had not been treated with a ceragenin. This work has demonstrated that ceragenins can be attached to polyamide reverse osmosis (RO) membranes, though work needs to improve the uniformity of the attachment. Finally, methods have been developed to use hyperspectral imaging with multivariate curve resolution to view ceragenins attached to the RO membrane. Future work will be conducted to better attach the ceragenin to the RO membranes and more completely test the biocidal effectiveness of the ceragenins on the membranes.
Date: December 1, 2008
Creator: Hibbs, Michael R.; Altman, Susan Jeanne; Feng, Yanshu (Brigham Young University, Provo, UT); Savage, Paul B. (Brigham Young University, Provo, UT); Pollard, Jacob (Brigham Young University, Provo, UT); Sanchez, Andres L. (LMATA, Albuquerque, NM) et al.
Partner: UNT Libraries Government Documents Department

Hydrogen separation membranes - annual report for FY 2007.

Description: 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.
Date: January 31, 2008
Creator: Chen, L.; Dorris, S. E.; Emerson, J. E.; Lee, T. H.; Park, C. Y.; Picciolo, J. J. et al.
Partner: UNT Libraries Government Documents Department

Simulating Nonuniform Properties in Polymer-Electrolyte FuelCells

Description: In this transaction, results from mathematical, pseudo 2-D simulations are shown for four different thickness distributions of both the membrane and cathode catalyst layer. The results and subsequent analysis clearly demonstrate that the position along the gas channel is more important than the local thickness variations, especially for the membrane.
Date: July 1, 2006
Creator: Weber, A.Z. & Newman, J.
Partner: UNT Libraries Government Documents Department

LDRD final report on imaging self-organization of proteins in membranes by photocatalytic nano-tagging.

Description: We have developed a new nanotagging technology for detecting and imaging the self-organization of proteins and other components of membranes at nanometer resolution for the purpose of investigating cell signaling and other membrane-mediated biological processes. We used protein-, lipid-, or drug-bound porphyrin photocatalysts to grow in-situ nanometer-sized metal particles, which reveal the location of the porphyrin-labeled molecules by electron microscopy. We initially used photocatalytic nanotagging to image assembled multi-component proteins and to monitor the distribution of lipids and porphyrin labels in liposomes. For example, by exchanging the heme molecules in hemoproteins with a photocatalytic tin porphyrin, a nanoparticle was grown at each heme site of the protein. The result obtained from electron microscopy for a tagged multi-subunit protein such as hemoglobin is a symmetric constellation of a specific number of nanoparticle tags, four in the case of the hemoglobin tetramer. Methods for covalently linking photocatalytic porphyrin labels to lipids and proteins were also developed to detect and image the self-organization of lipids, protein-protein supercomplexes, and membrane-protein complexes. Procedures for making photocatalytic porphyrin-drug, porphyrin-lipid, and porphyrin-protein hybrids for non-porphyrin-binding proteins and membrane components were pursued and the first porphyrin-labeled lipids was investigated in liposomal membrane models. Our photocatalytic nanotagging technique may ultimately allow membrane self-organization and cell signaling processes to be imaged in living cells. Fluorescence and plasmonic spectra of the tagged proteins might also provide additional information about protein association and membrane organization. In addition, a porphyrin-aspirin or other NSAID hybrid may be used to grow metal nanotags for the pharmacologically important COX enzymes in membranes so that the distribution of the protein can be imaged at the nanometer scale.
Date: November 1, 2005
Creator: Zavadil, Kevin Robert; Shelnutt, John Allen; Sasaki, Darryl Yoshio; Song, Yujiang & Medforth, Craig J.
Partner: UNT Libraries Government Documents Department

Three-dimensional architecture of hair-cell linkages as revealedby electron-microscopic tomography

Description: The senses of hearing and balance rest upon mechanoelectrical transduction by the hair bundles of hair cells in the inner ear. Located at the apical cellular surface, each hair bundle comprises several tens of stereocilia and a single kinocilium that are interconnected by extracellular proteinaceous links. Using electron-microscopic tomography of bullfrog saccular sensory epithelia, we examined the three-dimensional structures of ankle or basal links, kinociliary links, and tip links. We observed clear differences in the dimensions and appearances of the three links. We found two distinct populations of tip links suggestive of the involvement of two proteins or splice variants. We noted auxiliary links connecting the upper portions of tip links to the taller stereocilia. Tip links and auxiliary links show a tendency to adopt a globular conformation when disconnected from the membrane surface.
Date: July 28, 2006
Creator: Auer, Manfred; Koster, Bram; Ziese, Ulrike; Bajaj, Chandrajit; Volkmann, Niels; Wang, Da Neng et al.
Partner: UNT Libraries Government Documents Department