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 21 for “"oxygen-hydrogen"”.
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The chromium-oxygen-hydrogen equilibrium in liquid iron.
Massachusetts Institute of Technology. Dept. of Metallurgy. Thesis. 1945. Sc.D.
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Low-Temperature Internal Friction in the Niobium - Hydrogen and Niobium - Oxygen - Hydrogen Systems
Made available in DSpace on 2014-12-12T01:04:10Z (GMT). No. of bitstreams: 1 7500364.pdf: 2681652 bytes, checksum: 4bcad42d06b9189eb9b576b4a5e3efb5 (MD5) Previous issue date: 1974
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Plasma Treatment of Zinc Oxide Thin Film and Temperature Sensing Using the Zinc Oxide Thin Film
… zinc oxide thin films, films were treated with oxygen, hydrogen, and nitrogen plasmas. Oxygen plasma treatment improved the crystallinity of zinc oxide thin film. Hydrogen plasma treatments were found very effective in improving the electrical conductivity of the film sacrificing film’s …
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The Formation of Smoke in Flames
… is described, Results are presented for a simple oxygen / hydrogen flame to which two hydrocarbon fuels, ethylene and acetylene were added. The ethylene flame contained forty-two negative flame ion species, whereas the acetylene flame contained thirty-two. These ions are discussed in parallel, due …
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Geochemical methods for evaluating the origin and evolution of ground water in volcanic rocks
… in the Canary Archipelago. Stable isotopes of oxygen, hydrogen, carbon and sulfur were successfully used to delineate recharge zones and identify solute sources. Laboratory study of water-rock interactions established the source of solutes and the nature of the chemical reactions that control …
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Heat and fluid flow analysis in a molten CuCl heat exchanger
… cycle is a promising method to generate hydrogen as a clean fuel for human use in the future. The cycle can be coupled to nuclear reactors to supply its heat requirements. The cycle generates hydrogen by splitting water molecules through a series of chemical reactions. Thermal management …
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Modelling and Simulation of Carbon Dioxide Transportation in Pipelines: Effects of Impurities
… The impurities include nitrogen, methane, oxygen, hydrogen, sulphur dioxide, hydrogen sulphide, carbon monoxide, ammonia, argon, etc. The effects of the impurities are studied using simulation software; Aspen HYSYS, gPROMS and HydraFlash. The results show that all impurities impacted …
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Numerical investigation of the combustion of liquid oxygen droplets in an environment of hydrogen under microgravity conditions
… studies the configuration of a single liquid oxygen droplet surrounded by gaseous hydrogen diluted with helium. A numerical model using OpenFOAM as well as a coupled droplet evaporation model based on combining OpenFOAM results with the existing theoretical models have been developed to …
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Characterizing Variable Flow Pathways And Geochemical History Of Seepage Under The Mississippi River Levee: 2011, 2015, And 2016 Floods
… trace metals, tritium, and stable isotopes of oxygen, hydrogen, and strontium, enhanced understanding of the nature of flow and the geochemical evolution of the local groundwater. Geochemical signatures identify distinct deep and shallow flow pathways. Deeper flow pathways have lower redox …
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Energy Conversion Materials: Computational Design of Electrocatalysts Toward Sustainable Energy Applications
… electrochemical activities using water, oxygen, hydrogen, carbon dioxide to deliver renewable electricity and value-added chemicals. By using the density functional theory method, it is possible to explore the structural and electronic properties that govern a catalysts’ activity and …
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Investigation of stagnation-flow diamond-forming flames using advanced laser diagnostics
Gas phase temperature and atomic-hydrogen concentration profiles were measured near the deposition substrate in atmospheric-pressure, stagnation-flow diamond-forming flames. In these flames, a rich acetylene/oxygen/hydrogen mixture accelerates through a nozzle and impinges on a water-cooled …
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Stepped single crystals as improved model for supported catalysts: Ethylene, methanol and assorted molecules on platinum(511) and platinum(331)
… surface to break carbon-carbon and carbon-oxygen bonds. Methane formation from ethylene or ethane has been reported for supported platinum catalysts. A model for the methane formation on (1 x 1)Pt(110), was proposed by Yagasaki. In this study, the mechanism of methane formation has been …
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Uso de biomassa de microalgas e cianobactérias cultivadas em águas residuais de avicultura como potencial energético na produção de biodiesel e amônia como transportadora de hidrogênio
… as a fertilizer, but its application as a hydrogen carrier has recently grown. It has the capacity to store hydrogen at 17.7% by weight (corresponding to 120 g/L), superior to methanol (12.5%). Certain microbial biomasses have the capacity to produce ammonia from gasification. The advantage …
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Numerical Modelling of LOX Droplet Combustion in Hydrogen under Micro-gravity Conditions
… spray dispersion method is used to inject liquid oxygen into the combustion chamber, whereas hydrogen enters the combustion chamber in a gas phase, as it is most likely to be pre-vaporized due to the regenerative cooling in the rocket nozzle. When the LOX droplets ignite, combustion happens …
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Seepage of hydrocarbon bearing fluids at the Carlos Ribeiro and Darwin mud volcanoes (Gulf of Cadiz)
… but depleted in chloride relative to seawater. Oxygen, hydrogen and strontium isotope data suggest that the pore fluids are derived from depth and are affected by the transformation of smectite to illite. This process also produces pore fluids that are depleted in chloride and potassium, while B …
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Analyses of flame response to acoustic forcing in a rocket combustor
… experiments. BKH operates with liquid oxygen and gaseous hydrogen propellants at supercritical conditions analogous to real rocket engines. The chamber features an acoustic excitation system that imposes an acoustic disturbance representative of a high frequency instability upon a …
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Optimizing energy conversion efficiency of a proton exchange membrane green hydrogen generation system while incorporating balance of plant modeling
Hydrogen has the potential to decarbonize several difficult to decarbonize sectors of the U.S. energy economy such as medium- and heavy-duty transportation, energy storage, and industrial processes such as steel making. Currently most of the hydrogen produced globally is produced with steam methane …
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The molecular characterisation of the recA locus in the opportunistic pathogen Bacteroides fragilis
… by oxidative stress. The ability to survive oxygen stress is a strong indicator in an anaerobic bacterium of pathogenic potential and bacterial persistence in the oxygen rich peritoneal cavity. The aim of this thesis was to characterise the B. fragilis recA gene cluster with respect to its …
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Investigating recharge rates in Table Mountain springs using oxygen and hydrogen isotopes
This thesis investigates the monthly variation in hydrogen and oxygen isotope composition of four springs at the foot of Table Mountain, and by comparing this variation with that of local rainfall, estimates are made of their recharge rate. The oxygen, hydrogen, and EC data for Main spring, De Waal …
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Addressing Water Resource Issues In Barbados Through An Isotopic and Atmospheric Characterization of Precipitation Variability
<p>Numerous studies have analyzed isotopic variation of meteoric and dripwater in karst environments for paleoclimate reconstructions or aquifer recharge capacity. What is poorly understood is how the isotopic signal of δ<sup>18</sup>O and δ<sup>2</sup>H is transferred through the hydrologic cycle …
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