Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 19 of 19 for “"oxygen flux"”.
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Predicting induced sediment oxygen flux in oxygenated lakes and reservoirs
Bubble plume oxygenation systems are commonly used to mitigate anoxia and its deleterious effects on water quality in thermally stratified lakes and reservoirs. Following installation, increases in sediment oxygen flux (JO2) are typically observed during oxygenation and are positively correlated …
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Experimental investigations of oxygen-separating ion transport membranes for clean fuel synthesis
… the potential for 100% selective separation of oxygen from air. ITMs operate at extreme temperatures (>800°C), necessary for the mobility of lattice oxygen ions: this can result in significant experimental challenges. Specifically, the local gas compositions at both the high oxygen (air) and low …
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Multiphysics Computational Model of Fluid Flow and Mass Transport in Aneurysm
… wall. The extent that ILT presence reduces oxygen flux to the wall has not been quantified and there is rather a poor understanding of key parameters that can affect thrombus-mediated oxygen transport in AAA. The purpose of this study is to address this gap and to assess the effects of …
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Membrane-supported hydrogen/syngas production using reactive H₂O/CO₂ splitting for energy storage
… This thesis explores fuel production using oxygen permeable membranes. La₀.₉Ca₀.₁FeO₃-[subscript [delta]] (LCF-91) perovskite is used to develop a framework for reactor design based on a careful assessment of fuel production rates on the membrane design and operating conditions. This …
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Decomposition of Carbon Dioxide in a Capacitively Coupled Radio Frequency Discharge
… direct application of the study is to produce oxygen on the planet Mars. In such an experiment, oxygen was extracted and diffused through a silver membrane used as one of the electrodes during discharge. The oxygen flux produced by the present discharge condition was shown to reach about 5.0 × …
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Mathematical Modeling for Nitrogen Removal via a Nitritation: Anaerobic Ammonium Oxidation-Coupled Biofilm in a Hollow Fiber Membrane Bioreactor and a Rotating Biological Contactor
… in an HFMBR were investigated. The supply of oxygen was simulated with the flow through the lumen of the hollow fiber membrane. For the four scenarios, two scenarios investigated the start-up when nitrite was supplied in the feed while the other two scenarios investigated when the source of …
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Field scale trials of a geosynthetic capillary break
… waste by limiting the ingress of water and/or oxygen. The GCB is a geosynthetic system that is composed of a finely ground rock flour sandwiched between two nonwoven geotextiles and manufactured as a composite layer by needle punching in a process similar to the used for GCL (geosynthetic clay …
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Ecology and biogeochemistry of fluvial microphytobenthic communities on soft sediments
… on natural sediment. Potential nutrient flux was also shown to vary between geology and light levels, with differences being found between habitats within the same river. An attempt to remove variability in these systems using simulated natural sediment was not fully successful, although …
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A NOVEL MEDIATED OXYCOMBUSTION SYSTEM: SUBSYSTEM EVALUATION AND INTEGRATION
… The subsystems included a cerium based oxygen transport membrane, transport membrane coatings to assist in the pickup and release of oxygen, and a molten intermediary oxygen carrier. Various doping levels of yttrium and zirconium were investigated, both as singular dopants and in a …
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Mechanism of Metformin Action in Dermal Fibroblasts
… metformin specifically upregulated oxygen flux activity in fibroblasts, which was independent of AMPK activity. Metformin also altered expression of epithelial-mesenchymal transition (EMT) genes and markers. The primary EMT pathway regulated by metformin was SMAD3, which was …
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Production of biopolymer using a membrane-based bioreactor
… absence of nitrogen and presence of methane and oxygen. In this study, Colorado School of Mines (CSM) and Mango Materials (MM) collaborated on a Phase I NASA grant, investigating the production of PHB in a novel membrane-based bioreactor. Direct gas sparging is MM’s current method of gas …
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Oxygen Transport in the Human Placenta: A Multi-Physics Modelling Approach
… analysis (FEA), were combined to study the oxygen transport mechanism in the human placenta and its relationship to placental structure. Initial research relates to the development of a platform suitable for realistic computational simulations. The work shows how the 3D architecture of a …
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Experimental study and modeling analysis of ion transport membranes for methane partial oxidation and oxyfuel combustion
… Both require significant quantities of oxygen, whose production can impose considerable energy and economic penalties. Alternative technologies, such as intermediate-temperature ceramic membranes, operating under reactive conditions, promise to ameliorate both. Challenges include the …
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Modeling polymerization-based amplification
… orders-of-magnitude larger amounts of dissolved oxygen which acts as an inhibitor. We investigated the mechanism behind eosin's role in the polymerization process and its ability to initiate polymerization at concentrations lower than that of oxygen. A series of model simulation studies that …
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Fabrication and characterization of micro-tubular solid oxide fuel cells
… thickness, which consequently increases oxygen flux to the anode; and (b) using new electrolyte materials thereby making it possible for the fuel cell to operate at lower temperatures. The new material primarily investigated for the SOFC was strontium- and magnesium-doped lanthanum …
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Residence time in coastal canopies
… services such as improved water quality, oxygen flux, sediment stabilisation and trapping and recycling of nutrients. The ecological health of coastal canopies and the significant ecosystem services they provide depends largely on the continuous exchange of dissolved and particulate …
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Mass, heat and nutrient fluxes in the Atlantic Ocean determined by inverse methods
… in crossing the Atlantic. At 32°S the meridional flux of heat is .25±.19x1015 W equatorward, consistent in sign but smaller in magnitude than other recent estimates. This heat flux is carried primarily by a meridional overturning cell in which the export of 17 Sv of North Atlantic Deep Water …
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Mass, heat and nutrient fluxes in the Atlantic Ocean determined by inverse methods
… in crossing the Atlantic. At 32*S the meridional flux of heat is .25±.19x1015 W equatorward, consistent in sign but smaller in magnitude than other recent estimates. This heat flux is carried primarily by a meridional overturning cell in which the export of 17 Sv of North Atlantic Deep Water …
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An assessment of Eddy Correlation technique in marine habitats
Oxygen production and oxygen flux play an important role in marine habitats and ecosystems. The eddy correlation (EC) technique is a key aquatic flux measurement technique to measure and calculate vertical turbulent fluxes within aquatic boundary layers without disturbing environmental …