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 98 for “"Methane (CH4)"”.
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The effects of land use, temperature and water level fluctuations on the emission of nitrous oxide (N2O), carbon dioxide (CO2) and methane (CH4) from organic soil cores in Iceland
… nitrous oxide (N2O), carbon dioxide (CO2) and methane (CH4). The purpose of this study was to gain insight into the influence of temperature, water level and water level fluctuations on the GHG emission of soils representing the three major types of landuse in Iceland: undisturbed peatland, …
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Methane adsorption into sandstones and its role in gas recovery from depleted reservoirs
… process will lead to a better understanding of methane recovery in the EGR-CO2 process. Despite many pilot studies on EGR-CO2 in depleted reservoirs, no projects have moved to commercial phase, due to both technical and economic issues. This research demonstrated the role of adsorption as a …
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Optical Spectroscopy to Determine Intermediate Combustion Product Radicals in a Hydrocarbon Fueled Rocket Engine Exhaust Plume
… engines, such as Rocket Propellant 1 (RP-1) or methane (CH4) fueled engines being considered for use in future space flight systems, the contributions of intermediate or final combustion products resulting from these hydrocarbon fuels are of great interest. The effect of several diatomic …
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Astrochemical dynamics: Fundamental studies relevant to titan's atmosphere
… the reactions of state-prepared N2+ ions with methane (CH4), acetylene (C2H2) ethylene (C2H4), Hydrogen (H2) and acetonitrile (CH3CN) under a rotational temperature ~40 ± 5K.</p>
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Lattice parameter and thermal expansion in solid methane
The lattice parameter of a methane CH4 single crystal with an oxygen impurity of 0.01% has been measured in the range 2.5 to 86.2 K with a precise, back-reflection x-ray camera. The lattice parameters differ significantly from previous imprecise values in the literature. A first-order transition …
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Characterization of organics for anaerobic digestion by modelling augmented biological methane potential test results
… dynamic model for the simulation of biochemical methane potential (BMP) test results, as well as to determine the additional measurements required in the BMP assay procedure for the model to estimate the composition of a homogenous biodegradable particulate organic sample. This research would aid …
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Environmental and biological controls on carbon dioxide and methane exchange in a restored freshwater mineral-soil wetland at Frank Lake, Alberta
… these ecosystems are also strong emitters of methane (CH4), reducing their overall carbon (C) sequestration potential. This study presents growing season (May-September 2022) eddy covariance flux measurements of CO2 and CH4 at a prairie pothole wetland near High River, Alberta with extensive …
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Chemical sputtering studies of lithiated ATJ graphite
… The dominant chemical sputtering product is Methane (CH4). It was found that lithium treatments have suppressed the chemical sputtering of ATJ graphite. The suppression of chemical sputtering effect as function of varying lithium thickness on ATJ graphite has been thoroughly studied. The …
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Development and deployment of a novel deep-sea in situ bubble sampling instrument for understanding the fate of methane in the water column
Methane (CH4) is a potent greenhouse gas that is often found in a solid, hydrate clathrate form in marine sediments along continental margins and will often escape from the seafloor and rise through the water column as bubbles. The estimated marine methane hydrate inventory is over 600 times …
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Remoção de CO2 do biogás por permeação em membranas
… of a mixture of gases, composed mainly of methane (CH4 ) and carbon dioxide (CO2 ). Among the alternatives to reuse it, purification for injection into the natural gas grid is the most interesting option from an economical point of view. Biogas purification requires the removal of CO2 and …
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Modeling of Methane and Carbon Dioxide Sorption Capacity in Tight Reservoirs Using Machine Learning (ML) Techniques
… sets of experiments with 3806 data points where methane (CH4) and/or carbon dioxide (CO2) sorption capacity of shale and coal have been measured at different reservoir conditions. High-accuracy “integrated” shallow and deep learners/predictors were developed, without splitting the dataset into …
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Development of Ecosystem Structure and Function on Reforested Surface-Mined Lands
… carbon dioxide (CO2), nitrous oxide (N2O) and methane (CH4)], soil inorganic-N [nitrate (NO3-) and ammonium (NH4+)], and total and active microbial biomass were measured. Soil organic C (SOC) and total ecosystem C are returning to the mined landscape. Ecosystem C was correlated with N (r= 0.80; …
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Impacts of inundation and season on greenhouse gas fluxes from a low-order floodplain
… carbon dioxide (CO2), nitrous oxide (N2O), and methane (CH4), are produced naturally in the soil during the metabolism of many soil microbial and plant communities. The generation rate of GHGs depends on many factors, including soil community composition, nutrient availability, temperature, and …
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Quantifying Methane Emissions from the Greater Toronto Area
… emissions. In this study, I develop a new methane (CH4) emission inventory, using individual facility reports and emission estimates from area sources gathered for each municipality in the GTA. This allows us to have an emission inventory with a high spatial resolution that can be evaluated …
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Estimating the environmental costs of the hydro fuel cycle using life cycle assessment techniques and economic valuation
… Operations-phase emissions assessed include methane (CH4), carbon dioxide (CO2) and methyl mercury (MeHg), which are primarily associated with microbial activity in reservoirs. In the impact assessment, economic valuation is used to estimate the environmental impact associated with emissions …
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STUDY OF GAS ADSORPTION ON AS-PRODUCED AND MODIFIED CARBON NANOTUBES
… periods. Afterwards, adsorption measurements of Methane (CH4) were conducted on untreated and oxygen plasma treated tubes. The presence of an additional substep, after exposing multiwalled carbon nanotubes to oxygen plasma for varying time periods, suggested progressive cleaning of nanotube …
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Laboratory and field-based investigations of subsurface geochemical processes in seafloor hydrothermal systems
… 2 represents an experimental investigation of methane (CH4) formation under hydrothermal conditions. The overall reduction of carbon dioxide (CO2) to CH4, previously assumed to be kinetically inhibited in the absence of mineral catalysts, is shown to proceed on timescales pertinent to crustal …
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Fabrication SiO2 -NiO foam via replication technique for steam methane reforming catalyst at low temperatures
… properties as a criteria catalyst in the Steam Methane Reforming (SMR) application. In this work, the porous foam fabricated with different compositions of SiO2 as derived from Rice Husk Ash (RHA) (20% to 35%) and at different sintering temperatures (850°C to 1250°C) by using replication sponge …
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Methane in deep sea hydrothermal plumes. Development of a new in-situ methane sensing technology
… the concentration and distribution of dissolved methane (CH4), together with other geochemical tracers, in real time is of great value in detecting, monitoring, and understanding the functioning of hydrothermal plumes. Water column anomalies of light transmission, dissolved CH4, manganese (Mn), …
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Sea surface distribution of nitrous oxide and methane in European shelf seas and the Atlantic Ocean
… active gases, nitrous oxide (N2O) and methane (CH4), in the troposphere. There are currently uncertainties in quantifying the natural sources and sinks of N2O and CH4 in the marine environment. This thesis presents high-‐resolution surface-‐ocean and atmospheric data for N2O, CH4, CO2 …
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