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 “"Atmospheric methane"”.
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Novel Earth Abundant Catalytic Materials for Abatement of Atmospheric Methane Sources, and Evaluation of Agricultural Deployment Environments
… high global warming potential (GWP) and short atmospheric residence time (half-life of around 12 years) of methane make it a critical target for action to slow the pace of climate change in this decade. Yet technological solutions for methane abatement are challenged by methane’s inertness, …
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A global study of tropospheric methane chemistry and emissions
Methane is the second most important greenhouse gas after CO2 and affects atmospheric temperatures directly and indirectly. Through its chemical loss in the atmosphere, methane also influences tropospheric ozone concentrations, a major air polluter. Experiments have been performed with a …
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Development of a method for estimating methane gas emissions at high resolution
Methane is the second most important anthropogenic greenhouse gas, with a radiative warming of 0.97 [0.74-1.20] W m-2 (Stocker et al., 2013a) and a global warming potential of 21 times that of CO2 over a 100 year timescale (Reay et al., 2010). Its significance to climate change is significant …
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Investigating the Distribution and Biosynthesis of Modified F<sub>430</sub> Cofactors in Methanogenic and Methanotrophic Archaea
Methanogenesis is the biological production of methane and is utilized by methanogenic archaea (methanogens) to generate energy. This process is responsible for 70% of total atmospheric methane, a potent greenhouse gas and an important energy source (natural gas). In the future, reversing …
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Understanding Biogeochemical and Physical Controls on Methane Air-Sea Exchange Fluxes in the Pacific Ocean
<p>Methane and trace element samples were collected on GEOTRACES GP15 Pacific Meridional Transect (PMT) cruise conducted between the Aleutian Islands (57 °N) and Tahiti (20 °S) from September to November 2018. Uncertainty in methane air-sea exchange fluxes was determined using a propagation of …
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Atmospheric Impacts of Hydrogen as an Aviation Fuel
… overlooked. We quantify the perturbation in the atmospheric composition associated with the introduction of hydrogen-fueled aircraft, broadening the current understanding of the non-CO₂ effects of these fleets. We use the GEOS-Chem High Performance (GCHP) global chemistry-transport model to …
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Chemical transport by methane ebullition in a freshwater lake
Methane bubbling from lakes contributes significantly to atmospheric methane levels, and methane is second only to carbon dioxide in global warming potential. Microorganisms in aquatic sediments produce methane while consuming organic matter, and the majority of this methane is released via …
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Spatiotemporal variability of methane ebullition from lake sediments
Methane is a potent greenhouse gas, and natural sources to the atmosphere include inland waterways and shallow oceans. However, the magnitude of these emissions and their potential for feedbacks with climate change remain poorly constrained. In many settings the majority of atmospheric methane …
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Diversity of methane and short chain hydrocarbon degrading bacteria with an emphasis on methane biofilter systems
Methanotrophs house enzymes capable of methane oxidation, act as a sink for atmospheric methane and play a key role in the global carbon cycle. This study conducted multiple studies on methanotrophs, including: examination of the evolutionary history of copper membrane monooxygenases (CuMMOs), …
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Insights into communities, metabolic and ecological potential of the bacteria of two extreme acidic environments
… as WPS-2, AD3, Ca. Binatia, Elsterales, and atmospheric methane oxidizers ofthe genus Methylocapsa, compared to other habitats reported in the literature. Membersof the phylum WPS-2, also known as Eremiobacterota, dominated bare, nonvegetatedzones. Metabolically, it was proposed that these …
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Partitioning Biological and Anthropogenic Methane Sources
<p>Methane is an important greenhouse gas, and an ideal target for greenhouse gas emissions reductions. Unlike carbon dioxide, methane has a relatively short atmospheric lifetime, so reductions in methane emissions could have large and immediate impacts on anthropogenic radiative forcing. A more …
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An investigation of the combined stable isotopic composition of methane emissions from northern wetlands
Methane is a radiatively active, naturally occurring atmospheric trace gas which is thought to account for as much as 19% of the enhanced greenhouse effect. Ice core studies have shown that the atmospheric concentration has more than doubled since pre-industrial times. Wetlands are the largest …
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Effect of Peat Fuel Extraction and Peatland Reclamation on Vegetation and Greenhouse Gas Exchange
… and are the largest natural source of atmospheric methane (CH<sub>4</sub>). Peat is also an important resource and has been used as a fuel grade source of energy and for horticultural purposes in various countries for hundreds of years. The Ontario Government recently developed a target …
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Ice core methane and carbon monoxide as tracers of the terrestrial biosphere since the pre-industrial
… have been able to capture highly resolved atmospheric information over the most recent centuries. Instead, low-resolution measurements of firn air have often been used to bridge the gap between the end of ice core gas records and the start of direct atmospheric observations. Explanations …
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Methane distribution and oxidation across aquatic interfaces
The increase in atmospheric methane concentration, which is determined by an imbalance between its sources and sinks, has led to investigations of the methane cycle in various environments. Aquatic environments are of an exceptional interest due to their active involvement in methane cycling …
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Carbon and Nitrogen Dynamics of a Lagoon Salt Marsh in Davenport, California
… contributors to global climate change and atmospheric chemistry since they store as much as 33% of the world’s soil organic carbon (SOC), release more than 20% of the atmospheric methane (CH<sub>4</sub>), and produce nitrous oxide (N<sub>2</sub>O), an extremely potent greenhouse gas (GHG). …
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Atmospheric Mercury and Methane in the South-Central U.S.
… characterized temporal and spatial variations of atmospheric mercury and methane (CH4), and investigated their emission sources. Speciated atmospheric mercury observations collected over the period from 2008 to 2010 at the U.S. Atmospheric Mercury Network sites (AMNet) were analyzed. We found …
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Restoration of Degraded Land: A comparison of Structural and Functional Measurements of Recovery
… the rates observed in reference areas. Methane oxidation rates were generally increased in disturbed plots compared to undisturbed references due to increased atmospheric diffusion into the soil. Amended areas exhibited depressed rates relative to unamended, and seeding level had no …