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Peptoid-Modified Bicelles As Surrogate Cell Membranes For Membrane Protein Sensors And Analytics, Helya Najafi 2017 University of Arkansas, Fayetteville

Peptoid-Modified Bicelles As Surrogate Cell Membranes For Membrane Protein Sensors And Analytics, Helya Najafi

Theses and Dissertations

Membrane-affiliated interactions are significant in understanding cell function, detecting biomarkers to diagnose disease, and in testing the efficiency of new therapeutic targets. Model membrane systems have been developed to study membrane proteins, allowing for stable protein structure and maintaining native activity. Bicelles, disc-shaped lipid bilayers created by combining long- and short-chain phospholipids, are the model membrane system of focus in this study. Bicelles are accessible from both sides and have a wide size range, which make them attractive for studying membrane proteins without affecting function. In this work, bicelles were functionalized with two peptoids to alter the edge and face ...


Microbial Desalination Cells With Efficient Platinum Group Metal-Free Cathode Catalysts, Morteza Rezaei Talarposhti 2017 University of New Mexico

Microbial Desalination Cells With Efficient Platinum Group Metal-Free Cathode Catalysts, Morteza Rezaei Talarposhti

Chemical and Biological Engineering ETDs

Iron-nitrogen-carbon based catalyst was used at the cathode of a microbial desalination cell (MDC) and compared with platinum (Pt) and activated carbon (AC) cathode. Fe-N-C catalyst was prepared using nicarbazin (NCB) as organic precursor by sacrificial support method (SSM). Rotating ring disk electrode (RRDE) experiments shows that Fe-NCB had higher electrocatalytic activity compared to AC and Pt. The utilization of Fe-NCB into the cathode improved substantially the performance output with initial maximum power density of 49±2 μWcm-2 in contrast to Pt and AC catalysts which have shown lower values of 34±1 μWcm-2 and 23.5±1 ...


Hybrid Polymer Electrolyte For Lithium-Oxygen Battery Application, Amir Chamaani 2017 Amir Chamaani

Hybrid Polymer Electrolyte For Lithium-Oxygen Battery Application, Amir Chamaani

FIU Electronic Theses and Dissertations

The transition from fossil fuels to renewable resources has created more demand for energy storage devices. Lithium-oxygen (Li-O2) batteries have attracted much attention due to their high theoretical energy densities. They, however, are still in their infancy and several fundamental challenges remain to be addressed. Advanced analytical techniques have revealed that all components of a Li-O2 battery undergo undesirable degradation during discharge/charge cycling, contributing to reduced cyclability. Despite many attempts to minimize the anode and cathode degradation, the electrolyte remains as the leading cause for rapid capacity fading and poor cyclability in Li-O2 batteries. In this ...


Simulating Microbial Electrolysis For Renewable Hydrogen Production Integrated With Separation In Biorefinery, Christian James Wilson 2017 University of Tennessee, Knoxville

Simulating Microbial Electrolysis For Renewable Hydrogen Production Integrated With Separation In Biorefinery, Christian James Wilson

Masters Theses

Biomass conversion to hydrocarbon fuels requires significant amounts of hydrogen. Fossil resources typically supply hydrogen via steam reforming. A new technology called microbial electrolysis cells (MECs) has emerged which can generate hydrogen from organic sources and biomass. The thermochemical route to fuels via pyrolysis generates bio-oil aqueous phase (BOAP) which can be used to make hydrogen. A process engineering and economic analysis of this technology was conducted for application in biorefineries of the future. Steam methane reforming, bio-oil separation and microbial electrolysis unit operations were simulated in Aspen Plus to derive the mass and energy balance for conversion of biomass ...


Membrane Surface Engineering For Biochemical Applications, Anh T. Vu 2017 University of Arkansas, Fayetteville

Membrane Surface Engineering For Biochemical Applications, Anh T. Vu

Theses and Dissertations

Synthetic membranes have been frequently used for many fields, such as, the food and beverage, biopharmaceutical, and biofuel industries. In the beer industry, microfiltration frequently suffers from fouling due to the interaction between different species. It is shown that polyphenols can form cross-links with protein molecules, forming insoluble aggregates. However, by adding an optimal amount of polysaccharides these aggregates can be disrupted thus reducing fouling by the aggregates. Confocal laser scanning microscopy (CLSM) is a powerful technique to locate the foulants inside the wet membrane in order to understand more about the behavior of fouling in microfiltration.

Membrane surface modification ...


Membranes For Food And Bioproduct Processing, Alexandru Marius Avram 2017 University of Arkansas, Fayetteville

Membranes For Food And Bioproduct Processing, Alexandru Marius Avram

Theses and Dissertations

Modified membranes for process intensification in biomass hydrolysis

Production of biofuels and chemicals from lignocellulosic biomass is one of the leading candidates for replacement of petroleum based fuels and chemicals. However, conversion of lignocellulosic biomass into fuels and chemicals is not cost effective compared to the production of fuels and chemicals from crude oil reserves. Some novel and economically feasible approaches involve the use of ionic liquids as solvents or co-solvents, since these show improved solvation capability of cellulose over simple aqueous systems. Membranes offer unique opportunities for process intensification which involves fractionation of the resulting biomass hydrolysate leading to ...


Removal Of Endocrine Disrupting Compounds Using Membrane Bioreactor, Mohanad Ali Abdulsahib Kamaz 2017 University of Arkansas, Fayetteville

Removal Of Endocrine Disrupting Compounds Using Membrane Bioreactor, Mohanad Ali Abdulsahib Kamaz

Theses and Dissertations

The presence of endocrine disrupting compounds (EDCs) and pharmaceutically active compounds (PhAC) such as pesticides, personal care products, antibiotics and pharmaceutical compounds, in sewage, industrial, and domestic waters has extensively become the major concern for health and environmental organizations. These compounds have the ability to interact with mammalian endocrine system and disrupting their functions. The traditional activated sludge processes are designed to degrade solids, organic carbon and nitrogen loading. Although several treatment steps in a wastewater treatment plant can contribute to partial removal of EDCs, effective removal has been a challenge due to their resistant chemical and biological degradation and ...


Mesoporous Zsm-5 Zeolites In Acid Catalysis: Top-Down Vs. Bottom-Up Approach, Pit Losch, Thomas C. Hoff, Joy F. Kolb, Claire Bernardon, Jean-Philippe Tessonnier, Benoît Louis 2017 Université de Strasbourg

Mesoporous Zsm-5 Zeolites In Acid Catalysis: Top-Down Vs. Bottom-Up Approach, Pit Losch, Thomas C. Hoff, Joy F. Kolb, Claire Bernardon, Jean-Philippe Tessonnier, Benoît Louis

Chemical and Biological Engineering Publications

A top-down desilication of Al-rich ZSM-5 zeolites and a bottom-up mesopores creating method were evaluated in this study. Three liquid–solid and one gas–solid heterogeneously-catalysed reactions were chosen to establish relationships between zeolites textural properties and their catalytic behavior in acid-catalysed model reactions that are influenced by shape selectivity: Diels-Alder cyclization between isoprene and methylacrylate, Methanol-to-Olefins (MTO) reaction, chlorination of iodobenzene with trichloroisocyanuric acid (TCCA), and Friedel-Crafts acylation of anisole by carboxylic acids with differing sizes. It is found amongst others that no optimal mesoporosity for all the different reactions can be easily obtained, but depending on the chosen ...


Liquid Gating Ptfe Membranes To Reduce Fouling, Jonathan C. Overton 2017 University of Maine

Liquid Gating Ptfe Membranes To Reduce Fouling, Jonathan C. Overton

Electronic Theses and Dissertations

In the processing industry, fouling due to the accumulation of bioparticles or bacteria on the surface of membranes results in decreased capacity, and subsequently requires filtration membranes to require periodic cleaning, causing increased operating costs. In this work, we evaluate the recently discovered concept of liquid-gated membranes (LGMs) in both filtration characteristics, as well as their ability to facilitate passive cleaning of membranes fouled with whey proteins. Additionally, we show that biofilms formed on the surface of these membranes can be removed through exposure to an air-water interface through a simple dipping step. We further analyze the mechanisms of fouling ...


Biomass Utilization Of Carbon, Kathryn M. Hopfensperger, Catherine Brame, Mary Uselmann, Traci Reusser 2017 University of Wyoming

Biomass Utilization Of Carbon, Kathryn M. Hopfensperger, Catherine Brame, Mary Uselmann, Traci Reusser

Honors Theses AY 16/17

The goal of this project was to address the environmental implications of an algae biomass system that sequesters carbon dioxide to produce economically valuable products. The Algalrithm, a theoretical company driven by reducing CO2 emissions, chose a final product based upon the results of economic analyses that considered potential carbon capture and utilization incomes, as well as the value of diverse products under various commodity pricing constraints. Many algae-based bio-products were considered before narrowing in on a specific product that would encompass the volume of typical utility-scale electricity producing plants, a wide range of future carbon costs, and the ...


Morphological And Photoelectrochemical Characterization Of Membrane Reconstituted Photosystem I (Psi), Seyedeh Hanieh Niroomand 2017 University of Tennessee, Knoxville

Morphological And Photoelectrochemical Characterization Of Membrane Reconstituted Photosystem I (Psi), Seyedeh Hanieh Niroomand

Doctoral Dissertations

The robust structural and photoactive electrochemical properties of Photosystem I (PSI), a transmembrane photosynthetic protein complex, make it an ideal candidate for incorporation into solid state bioelectronic or hybrid photovoltaic devices. However, the first step towards the successful fabrication of such devices requires systematic assembly of oriented and functional PSI onto desired bio-abio interfaces via suitable protein scaffoldings. Hence, this dissertation focuses on utilizing the cyanobacterial PSI for integration into organic/inorganic interfaces that mediate photo-electrochemical energy conversions for electricity and/or solar fuel production. To this end, in this study the effect of systematic incorporation of PSI complexes into ...


An Investigation Of Lsf-Ysz Conductive Scaffolds For Infiltrated Sofc Cathodes, Yuan Cheng, Tae-Sik Oh, Rachel Wilson, Raymond J. Gorte, John M. Vohs 2017 University of Pennsylvania

An Investigation Of Lsf-Ysz Conductive Scaffolds For Infiltrated Sofc Cathodes, Yuan Cheng, Tae-Sik Oh, Rachel Wilson, Raymond J. Gorte, John M. Vohs

Departmental Papers (CBE)

Porous compostites of Sr-doped LaFeO3 (LSF and yttria-stabilized zirconia (YSZ) were investigated as conductive scaffolds for infiltrated SOFC cathodes with the goal of producing scaffolds for which only a few perovskite infiltration steps are required to achieve sufficient conductivity. While no new phases form when LSF-YSZ composites are calcined to 1623 K, shifts in the lattice parameters indicate Zr can enter the perovskite phase. Measurements on dense, LSF-YSZ composites show that the level of Zr doping depends on the Sr:La ration. Because conductivity of undoped LSF increases with Sr content while both the iconic and electronic conductivities of ...


A Quartz Crystal Microbalance Study Of Thiol:Ene Poly(Ionic Liquid) Polymerization And Gas Absorption, yueming wu 2017 Murray State University

A Quartz Crystal Microbalance Study Of Thiol:Ene Poly(Ionic Liquid) Polymerization And Gas Absorption, Yueming Wu

Murray State Theses and Dissertations

ABSTRACT

The polymerization process of, and gas absorption by, imidazolium-containing thiol:ene poly (ionic liquid)s (PILs), prepared from bisallylimidazolium bis(trifluoromethyl sulfonyl)imide [NTf2-] and pentaerythritoltetrakis(3 mercaptopropionate), was studied. The thiol:ene PILs examined were recently reported by groups at Murray State University. The advantage of thiol:ene PILs over other reported PILs is that thiol:ene polymers are made rapidly by UV exposure and exhibit high mechanical and thermal stability due to high cross-linking. The properties of interest for the thiol:ene PILs were studied using a quartz crystal microbalance (QCM). QCM techniques are based on ...


Tunable Nanocomposite Membranes For Water Remediation And Separations, Sebastián Hernández Sierra 2017 University of Kentucky

Tunable Nanocomposite Membranes For Water Remediation And Separations, Sebastián Hernández Sierra

Theses and Dissertations--Chemical and Materials Engineering

Nano-structured material fabrication using functionalized membranes with polyelectrolytes is a promising research field for water pollution, catalytic and mining applications. These responsive polymers react to external stimuli like temperature, pH, radiation, ionic strength or chemical composition. Such nanomaterials provide novel hybrid properties and can also be self-supported in addition to the membranes.

Polyelectrolytes (as hydrogels) have pH responsiveness. The hydrogel moieties gain or lose protons based on the pH, displaying swelling properties. These responsive materials can be exploited to synthesize metal nanoparticles in situ using their functional groups, or to immobilize other polyelectrolytes and biomolecules. Due to their properties, these ...


Functionalization Of Silver Nanoparticles On Membranes And Its Influence On Biofouling, Conor G. Sprick 2017 University of Kentucky

Functionalization Of Silver Nanoparticles On Membranes And Its Influence On Biofouling, Conor G. Sprick

Theses and Dissertations--Chemical and Materials Engineering

Ultrafiltration (UF) processes are often used as pretreatment before more retentive/costly processes, such as nanofiltration and reverse osmosis. This study shows the results of low-biofouling nanocomposite membranes, loaded with casein-coated silver nanoparticles (casein-Ag-NPs). Membranes were cast and imbedded with Ag-NPs using two approaches, physical blending of Ag-NPs in the dope solution (PAg-NP/CA membranes) and chemical attachment of Ag-NPs to cast membranes (CAg-NP/CA membranes), to determine their biofouling control properties. The functionalization of Ag-NPs onto the CA membranes was achieved via attachment with functionalized thiol groups with the use of glycidyl methacrylate (GMA) and cysteamine chemistries ...


Modeling Of Nanoscale Transport In Mesoporous Membranes, Ashutosh Rathi 2017 University of Massachusetts Amherst

Modeling Of Nanoscale Transport In Mesoporous Membranes, Ashutosh Rathi

Doctoral Dissertations

Mesoporous membranes with pore sizes in the range 2-50 nm provide an energy efficient alternative for separation of mixtures such as CO2 from stack effluents and volatile organic compounds (VOC) from air. Transport mechanisms such as capillary condensation, Knudsen diffusion and surface adsorption help in enrichment of a more condensable component based on the bulk mixture thermodynamics, surface chemistry and geometry of the mesopores. Despite the progress in synthesis techniques, design of better mesoporous materials for targeted separations is still a challenge due to the absence of clear design rules. Modeling techniques can be used to quantify the relevant ...


Quantifying Gauche Defects And Phase Evolution In Self-Assembled Monolayers Through Sessile Drops, Jiahao Chen, Boyce Chang, Stephanie Oyola-Reynoso, Zhengjia Wang, Martin M. Thuo 2017 Iowa State University

Quantifying Gauche Defects And Phase Evolution In Self-Assembled Monolayers Through Sessile Drops, Jiahao Chen, Boyce Chang, Stephanie Oyola-Reynoso, Zhengjia Wang, Martin M. Thuo

Materials Science and Engineering Publications

Self-assembled monolayers (SAMs) are widely used in surface modifications, specifically in tuning the surface chemistry of materials. The structure and properties of SAMs have been extensively studied often with sophisticated tools, even for the simplest n-alkanethiolate SAMs. In SAMs, especially in linear n-alkanethiolates, the properties are dependent on the chain length, which is best manifested in the so-called odd–even effect, a simple yet not fully understood phenomenon. One main challenge is fully delineating the origin of length-dependent properties, which can be due to the structure (ideal SAMs), defect evolution, or substrate-molecule effects. This study demonstrates that utilizing ...


Biomimetic Devices To Drive A Thermodynamically Uphill Reaction Using Light And To Degrade Industrial Waste Stream Components, Madison JoAnne Sloan 2017 University of Kentucky

Biomimetic Devices To Drive A Thermodynamically Uphill Reaction Using Light And To Degrade Industrial Waste Stream Components, Madison Joanne Sloan

Theses and Dissertations--Chemistry

Given the amount of industrial waste produced each year, as well as the accruing amount of greenhouse gases in our atmosphere produced by the burning of fossil fuels, it is imperative that humanity develop environmentally-sustainable sources of energy and methods of remediation. Nature achieves both of these by use of enzymes as catalysts, inspiring interest in designing biomimetic systems capable of harnessing clean energy and remediating industrial waste. This study examined the ability of enzymes in electrochemical and convective flow systems to achieve these tasks. The first portion studied the incorporation of enzymes into an electrochemical system to drive the ...


Pore-Confined Carriers And Biomolecules In Mesoporous Silica For Biomimetic Separation And Targeting, Shanshan Zhou 2017 University of Kentucky

Pore-Confined Carriers And Biomolecules In Mesoporous Silica For Biomimetic Separation And Targeting, Shanshan Zhou

Theses and Dissertations--Chemical and Materials Engineering

Selectively permeable biological membranes composed of lipophilic barriers inspire the design of biomimetic carrier-mediated membranes for aqueous solute separation. This work imparts selective permeability to lipid-filled pores of silica thin film composite membranes using carrier molecules that reside in the lipophilic self-assemblies. The lipids confined inside the pores of silica are proven to be a more effective barrier than bilayers formed on the porous surface through vesicle fusion, which is critical for quantifying the function of an immobilized carrier. The ability of a lipophilic carrier embedded in the lipid bilayer to reversibly bind the target solute and transport it through ...


Investigating The Synergistic Effects Of Combined Modified Alginates On Macrophage Phenotype, Hannah C. Bygd, Kaitlin M. Bratlie 2016 Iowa State University

Investigating The Synergistic Effects Of Combined Modified Alginates On Macrophage Phenotype, Hannah C. Bygd, Kaitlin M. Bratlie

Materials Science and Engineering Publications

Understanding macrophage responses to biomaterials is crucial to the success of implanted medical devices, tissue engineering scaffolds, and drug delivery vehicles. Cellular responses to materials may depend synergistically on multiple surface chemistries, due to the polyvalent nature of cell–ligand interactions. Previous work in our lab found that different surface functionalities of chemically modified alginate could sway macrophage phenotype toward either the pro-inflammatory or pro-angiogenic phenotype. Using these findings, this research aims to understand the relationship between combined material surface chemistries and macrophage phenotype. Tumor necrosis factor-α (TNF-α) secretion, nitrite production, and arginase activity were measured and used to determine ...


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