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 948 for “"organic carbon"”.
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Biogeochemical Alteration of Particulate Pyrogenic Organic Carbon (pyC)
<p>The resistance of plant derived pyrogenic organic carbon (<em>py</em>C) to abiotic and biotic means of degradation has led to increased interest in the role of <em>py</em>C as a potential carbon sink, as well as a strategy for sequestering atmospheric CO2 to mitigate excess carbon emissions. …
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Understanding terrestrial organic carbon export : a time-series approach
Terrestrial organic carbon (OC) erosion, remineralization, transport through river networks, and burial in marine sediments is a major pathway of the global carbon cycle. However, our ability to constrain these processes and fluxes is largely limited by (i) analytical capability and (ii) temporal …
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Organic/carbon nanotubes hybrid thin films for chemical detection.
… attributed to their unique chemical structure. Carbon nanotubes (CNT), on the other hand, are known to enhance the properties of nano-composites in the conjugated molecules, due to their one dimensional electronic skeleton, high surface area and high aspect ratio. In this thesis, work has been …
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Understanding terrestrial organic carbon export : a time-series approach
Terrestrial organic carbon (OC) erosion, remineralization, transport through river networks, and burial in marine sediments is a major pathway of the global carbon cycle. However, our ability to constrain these processes and fluxes is largely limited by (i) analytical capability and (ii) temporal …
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Coupled Biogeochemical Cycles of Iron and Organic Carbon in Soils
Soil organic carbon (OC) is one of the largest carbon (C) reservoirs on the Earth's surface. Because of the high sorption affinity of iron (Fe) minerals for OC, the redox reactions of Fe potentially play an important role in regulating the stability and transformation of OC in soils. Fate of …
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Organic carbon dynamics of the Neches River and its floodplain.
… river that has an extensive forested floodplain. Organic carbon was analyzed within the floodplain waters and the river (upstream and downstream of the floodplain) to determine the amount of organic carbon from the floodplain that is contributing to the nutrient dynamics in the river. Dissolved …
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Measurement of lignin and organic carbon in Lake Mead sediment
… tool for tracing the transport of land derived organic matter in an aquatic environment. Tetramethylammonium hydroxide (TMAH) thermochemolysis at sub-pyrolysis temperatures of 300°C followed by GC-MS analysis showed a great promise in being able to semi quantitatively assess the nature of …
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Sediment and Organic Carbon Variability in a Tropical Urban Catchment.
The aim of this research is to understand the effect on sediment and contaminant accumulation into a reservoir. Five gauging stations were deployed within the Marina Barrage Catchment, Singapore. Different spatial and temporal scales of comparisons of various hydrological parameters were made. An …
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Multifunctional woody polycultures and their influence on soil organic carbon
… food production, habitat for biodiversity, and carbon (C) sequestration. Soil organic matter fractions (particulate organic matter [POM], and potentially mineralizable N [PMN]), inherent soil and landscape factors were quantified on samples collected using plot- and grid-based approaches to …
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Predicting Spatial Variability of Soil Organic Carbon in Delmarva Bays
… health, and wetland restoration rely on soil organic carbon (SOC) as vital for microbial activity and plant health. This study assessed: (1) accuracy of topographic-based non-linear models for predicting SOC; and (2) the effect of analytic strategies and soil condition on performance of …
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Organic Carbon Generation Mechanisms in Main and Premise Distribution Systems
Assimilable organic carbon (AOC) is a suspected contributor to growth of microbes, including pathogens, in plumbing systems. Two phases of research were completed to improve knowledge of AOC and other forms of organic carbon in premise plumbing. In the first phase, the AOC Standard Method 9217B was …
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Spatial Variability of Metals and Organic Carbon In Salt Marsh Sediment
<p>The occurrences of pollutants in salt marsh, especially metals, have been widely studied due to their adverse effects on ecosystem. However, most of the studies use single measurement to assess the metal contamination and ignore the spatial variability of sediment metal concentration. In this …
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Optimization Techniques for Soil Organic Carbon Prediction Using Mid-Infrared Spectroscopy
… techniques for accurate soil carbon estimation are necessary to satisfy the increasing demand for spatiotemporal data. In the last thirty years, mid-infrared (MIR) soil spectroscopy has developed as an accurate, rapid, cost-effective, and non-destructive technique for soil …
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Relationships among Root Traits, Nitrogen Availability, and Mineral-Associated Organic Carbon
Mineral-associated organic carbon (MAOC) is a vital component of soil health and ecosystem productivity, playing a key role in carbon (C) sequestration and nutrient cycling. This dissertation investigates how plant root traits, nitrogen (N) fertilization, and cover cropping influence soil organic …
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Evaluation of Anaerobic Biodegradation of Organic Carbon Extracted from Aquifer Sediment
… method for quantifying potentially biodegradable organic carbon (Rectanus et al 2005), this research was conducted to evaluate the extent to which organic carbon extracted using this method will biodegrade in anaerobic environments. The ultimate goal is to use this method for the evaluation of …
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Mechanisms of terrestrial organic carbon export and preservation in the marine environment
Export of terrestrial carbon from land to sea is a globally important carbon flux that is poorly constrained and has implication for atmospheric carbon levels over modern and geologic timescales. Many factors control the fate of exported carbon and the subsequent impact on carbon budgets, including …
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Organic Carbon Cycling in East China Sea Shelf Sediments: Linkages with Hypoxia
… main source of sediment and terrestrial derived organic carbon (OC) to the Changjiang large delta-front estuary (LDE) in the East China Sea (ECS). This study analyzed bulk OC, biomarkers including lignin and plant pigment, black carbon (BC) on ECS sediments sampled in winter 2009 and 2010 in …
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Dissolved organic carbon and colour dynamics in drained and restored blanket peat
Peatlands are important terrestrial stores of carbon and a principal source of dissolved organic carbon (DOC) to the fluvial environment. Whilst often regarded as a net carbon sink, enhanced DOC concentrations and an associated rise in the level of water discolouration observed in many artificially …
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Salt retention in wetland soils and effects on dissolved organic carbon export
… spots for many nutrients including carbon. The interactions between deicing salt runoff and wetland soil carbon were explored by measuring chloride export and retention, dissolved organic carbon (DOC) export, and carbon quality using mesocosm experiments. Net retention of Cl- was …
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