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 18 of 18 for “"methane hydrates"”.
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Formation and characterization of pure methane hydrates and methane hydrates in unconsolidated and consolidated sediments
Includes bibliographical references.
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Dynamics of confined chemical gardens and implications for submarine methane hydrates
… to geological fluid and venting systems of methane. The precipitate filaments grown in the laboratory are used as a theoretical analogue of the spreading of methane hydrates under the seabed. We discuss how this methane venting leads to the formation of marine authigenic carbonate rocks, and …
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Heat capacity and heat of dissociation of methane hydrates: a new approach, The
Includes bibliographical references (pages 124-127).
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Modeling of gas hydrates from first principles
… surface (PES) accurately for use in modeling gas hydrates. Electron correlation was found to be treated accurately by the second-order Moller-Plesset method (MP2). However, a large basis set, cc-pVQZ, was found to be necessary in order to compute the binding energies to within 0.1 kcal/mol of the …
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Governance of Offshore Freshwater Resources
… two completely different forms: aquifers and methane hydrates. Neither of these reserves has been commercially developed, and, while current technology could be utilized for aquifers, methods for extracting freshwater from methane hydrates do not yet exist. Given the vital and unique nature of …
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Multiphase flow in porous media with phase transitions : from CO₂ sequestration to gas hydrate systems
… long-term storage. Among natural contributors, methane hydrates, an ice-like substance commonly found in seafloor sediments and permafrost, hold large amounts of the world's mobile carbon and are subject to an increased risk of dissociation due to rising temperatures. The dissociation of methane …
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Preferential mode of gas invasion in sediments : grain-scale model of coupled multiphase fluid flow and sediment mechanics
… pattern. In coarse sediments, the buoyant methane gas is likely to invade the pore space more uniformly, in a process akin to invasion percolation, and the overall pore occupancy is likely to be much higher than for a fracture-dominated regime. These implications are consistent with …
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Investigation into potential gas hydrate and gas zones off the South African coastline
… is formed when a gas molecule (such as methane) is trapped in a lattice of ice. Once considered oilfield nuisances, they are now being considered as an alternative fuel source. I asked whether any indications of hydrates, and gas, were present off the South African coastline within Block …
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Experimental Study of the PVTX Properties of the System H₂O-CH₄
… A study has also been conducted to determine methane hydrate stability over the temperature range of -40~20°C. Synthetic fluid inclusions were employed in both studies as miniature autoclaves. Experimental data for the PVTX properties of H₂O-CH₄ fluids under late diagenetic to low grade …
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Stability of Methane-Ethane-Propane Mixed Gas Hydrates under Deep Water Conditions
Methane hydrates are globally distributed in sediments along the continental margins and potentially contain more energy than all fossil fuel reserves. However, methane is also a potential greenhouse gas which could play a major role in global climate change. Understanding the stability of gas …
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A magmatic trigger for the Paleocene-Eocene Thermal Maximum?
… isotopically light carbon (<13C/12C values) from methane hydrates, terrestrial or marine organic matter, as indicated by a pronounced excursion to light carbon isotope values across the PETM. I test the hypothesis that the PETM warming and isotope excursion were caused by the intrusion of a …
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The comparison of experimental and theoretical hydrate numbers
… determination of the hydrate numbers of gas hydrates were developed. Hydrate numbers (the ratio of the moles of water to moles of gas in the gas hydrate) were determined for pure component ethane and methane hydrates at several equilibrium decomposition conditions and compared with hydrate …
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Impact of Hydrate Dissociation on the Stiffness and Strength of Hydrate Bearing Sands
… energy resources, notably natural gas hydrates. These ice-like compounds, abundant in permafrost and marine sediments, harbor vast quantities of methane, a potent energy source. However, conventional methods for recovering methane gas from natural hydrate bearing sand (HBS) deposits …
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A magmatic trigger for the Paleocene-Eocene thermal maximum?
… isotopically light carbon (<¹³C/¹²C values) from methane hydrates, terrestrial or marine organic matter, as indicated by a pronounced excursion to light carbon isotope values across the PETM. I test the hypothesis that the PETM warming and isotope excursion were caused by the intrusion of a …
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Probing Nucleation Mechanisms of Gas Hydrates via Molecular Simulations
Gas hydrates are ice-like solids where guest species can be encapsulated in water cages. Gas hydrates have received considerable attention because of the vast natural methane hydrates and various promising hydrate-based technologies. Relevant to the applications, a fundamental molecular-level …
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Application of superparamagnetic nanoparticle-based heating for non-abrasive removal of wax deposits from subsea oil pipelines
… flow of hydrocarbon-based fluids by formation of methane hydrate and wax deposits on the inner surface of pipelines. Commonly used methods for removal of deposits from pipelines are chemical injection and foam or gel pigs, which face several limitations. In our work, an application to use …
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Pore size distribution and methane equilibrium conditions at Walker Ridge Block 313, northern Gulf of Mexico
… and pore size may allow coexistence of three methane phases: liquid (L), gas (G), hydrate (H) in marine gas hydrate systems. A discrete zone of three-phase equilibrium may occur near the base of the gas hydrate stability zone (GHSZ) in sediments with salinity close to seawater due to capillary …
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On the theory of Brownian aggregation in colloidal dispersions
Brownian aggregation kinetics is a topic of interest for colloidal dispersions, macromolecular fluids, nanoparticle self-assembly, and biochemical reactions. The manipulation of colloidal dispersion stability by containing or promoting aggregation rates is manifest in several natural phenomena and …