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 20 of 22 for “"Mixed gas"”.
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Fundamental studies of mixed gas plasmas in ICP-MS
… analyzed. This study has investigated the use of mixed gas plasmas as a means of reducing or removing these interference effects. In addition the use of mixed gas plasmas for sensitivity enhancement has been assessed using both wet and dry sample introduction systems. Simplex optimization …
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Combustion dynamics of metal powders in mixed gas flows
… rates of Al, Mg, and Al-Mg alloys in various gas environments.
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Mixed Gas Transport Study Through Polymeric Membranes: A Novel Technique
The gas transport and separation properties of polymers have been successfully exploited in commercial ventures. Industrial applications employing membrane processes range from production of pure gases to barrier coatings for protection against environmental elements. Membrane separations are …
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Stability of Methane-Ethane-Propane Mixed Gas Hydrates under Deep Water Conditions
… However, methane is also a potential greenhouse gas which could play a major role in global climate change. Understanding the stability of gas hydrates can help us to understand their role in the climate change. Three main factors affect the stability of hydrates: Temperature (T), Pressure (P) …
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Mixed-gas Transport in Microporous Polymer Derivatives for Energy-Efficient Gas Separations
Over the past forty years, membrane-based gas separations have emerged as a promising alternative to energy-intensive separation processes such as amine absorption and cryogenic distillation. However, a trade-off between permeability and selectivity as well as issues of decreased performance at …
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Synthesis, Characterization, Membrane Fabrication and Gas Transport Behavior of Liquid Crystal Polymer Materials
… with higher LC concentrations exhibited a higher mixed gas permeability and selectivity for propylene. Permeability selectivity decreased across the smectic to nematic phase transition. Overall, selectivities were low, and membrane stability was a significant problem, especially at higher …
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Evaluation of slurry injection for the determination of metals in solid samples using inductively coupled plasma atomic emission spectrometry
… tension, viscosity, and aerosol droplet size. Mixed gas plasma containing small amounts of nitrogen were used. Results showed that, by adding about 5 ppm of PEO, the emission intensity of an analyte increased significantly. Further experiments demonstrated that the signal enhancement resulted …
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Designing Microporous Polymers for Separations
… is fabricated into a free-standing film. Pure-gas experiments are performed to explore the impact of dispersity and side chain length on gas separation performance. In Chapter 2, we evaluate the mixed-gas performance of a class of bottlebrush polymers described in Chapter 1. Gas sorption, …
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Some studies relating to the design of shallow, fluidized bed boilers
… defined and a preliminary working design for a gas-fired package boiler has been produced. Those areas of the design requiring further study have been specified. Experimental investigations concerning these areas have been carried out. A two-dimensional, conducting paper analog has been …
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A Study on the Heavy Crude Oil Viscosity Reduction with the Dissolution of Nitrogen and Carbon Dioxide
… different compositions of the mixture of the two gases were also injected. In the first mixture, varied quantities of the two gases were used; 62:5%, 82:2% and 86:4% of the mixture was nitrogen while 37:5%, 17:8% and 13:6% was carbon dioxide at total test pressures of 100, 300 and 500 psi. The …
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Development and testing of inorganic membranes for hydrogen separation and purification in a catalytic membrane reactor.
… the effect of annealing at higher temperatures. Gas permeation through silica and alumina membranes was investigated for five single gases including hydrogen. The silica and alumina membranes were fabricated using the dip-coating method and their hydrogen permeation behaviour investigated at …
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Inkjet Printed Graphene-Based Smart Gas Sensors
The current commercial landscape for gas sensing is dominated by metal oxide (MOx) based sensors due to their balance of performance and cost as well as the opportunity for simple device integration, potential for miniaturisation and incorporation into multi-analyte detection systems. However, MOx …
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Hypoxic Incubation Chamber
… hypoxic incubator with fully functional oxygen gas control and temperature control in a humid environment. On the current market, a majority of the few hypoxic incubators use pre-mixed gas that does not offer precise control over gas concentration. The objective for this project was to create a …
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Instrumentation and contrast mechanisms in scanning helium microscopy
… focusses on new contrast mechanisms. By using a mixed gas beam, it is possible to simultaneously probe a surface with atoms at different energies and wavelengths, and the first such images are presented. It is well known that atom beams will diffract from well-ordered surfaces, and diffraction …
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Free Volume Manipulation Techniques of Polymer Membranes for Gas Separations
Gas separations are ubiquitous in today’s industries and society, playing a role in many key applications such as oxygen generation for medical procedures and natural gas separations for power generation and petrochemicals. In the United States, separation processes consume about 16 quadrillion BTU …
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Innovative hydrocarbons recovery and utilization technology using reactor-separation membranes for off-gases emission during crude oil shuttle tanker transportation and natural gas processing.
The increase in greenhouse gas (GHG) concentrations in the atmosphere, as well as the high rate of depletion of hydrocarbon-based resources have become a global concern. A major source of emissions of hydrocarbon vapours occur during loading and offloading operations in crude oil shuttle tanker …
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Composite inorganic membranes for hydrogen reaction, separation and purification.
… Then, the effects of thermal treatment on the gas transport and micro pore structure of the resulting membranes were investigated. The pore size of the silica membrane prepared by conventional technique was in the range of approximately 8 to 11 nm while that prepared by modified dip-coating was …
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Synthesis, Fabrication and Surface Modification of Nanocrystalline Nickel Oxide for Electronic Gas Sensors
Recently, metal oxide gas sensors have attracted much attention in connection with monitoring of combustible and toxic gases because of their higher sensitivity, fast response and recovery times, low power consumption, and low fabrication cost. Nickel oxide (NiO) is a wide band gap and p-type …
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Caratterizzazione di membrane metalliche e ionomeriche per applicazioni energetiche
… permeation in Pd-based systems. Pure and mixed gas permeation tests were performed on Pd-based hydrogen selective membranes at operative conditions close to steam-reforming ones. Two membranes (one produced in this work and another produced by NGK Insulators Japan) showed a virtually …
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Understanding human-space suit interaction to prevent injury during extravehicular activity
… component of human spaceflight. Working in gas-pressurized space suits, however, causes fatigue, unnecessary energy expenditure, and injury. The problem of injury is particularly acute and is exacerbated with the additional hours astronauts spend training inside the suit, especially …
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