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 77 for “"Nitrate concentration"”.
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Baseline Study for Monitoring Variations in Nitrate Concentration in Surface Waters of Cuyamaca Rancho State Park in Relation to Watershed Types
… of this study was to compare the variations in nitrate concentration in the surface waters of five different watershed community types at Cuyamaca Rancho State Park. Monthly water samples were collected at selected sites below each watershed and analyzed by use of a specific ion electrode for …
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Ecorestoration of riparian forests for nonpoint source pollution control: Policy and ecological considerations in Illinois agroecosystem watersheds
… policy. Trend analysis showed that concentrations of nitrate, dissolved phosphorus, and total phosphorus were not reduced in thirteen watersheds between 1986 and 1992 despite implementation of the CRP program. Average stream nitrate concentration between 1977 and 1992 (7.2 mg/L) was …
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Algal nutrients: sources and patterns of flow in the Occoquan Watershed
… Bull Run waters were highest in phosphate and nitrate concentration. Both phosphate and nitrate concentrations were found to correlate highly with AGP for green and blue green test species. For the green alga Selenaetrum capricornutum, the chemical nutrient most highly correlated with AGP was …
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Investigating nitrate attenuation in an urban stream using stable isotope geochemistry and continuous monitoring
… discharge, and biological processing on nitrate concentrations in an urban stream during high and low flow periods. A wastewater treatment plant (WTP) on Pennypack Creek, an urban stream near Philadelphia, PA, increases nitrate concentrations to a mean of 8.5 mg-l-1 (as N). Concentrations …
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Smart-phone-based electrochemical sensor for environmental applications
… a smart phone. This platform was used to measure nitrate concentration using a few microliter liquid samples on field along with providing geospatial map locations through a wireless network. This compact MoboSens platform (~65 gram), based on a smart phone, is able to detect nitrate concentration …
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Wind induced entrainment in the Strait of Georgia and the possible consequences for fish survival
… their early lives in the area, by supplying nitrate rich deep water to the photic zone and increasing primary productivity. Historical records of winds and Fraser River discharge were used to drive the combined GF4/MULES physical/biological model, to simulate entrainment and nitrate …
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Reaction condition effects on Re(VII) sorption kinetics at the zerovalent iron-water interface
… be tested. Because LLW is in caustic brine (high nitrate) solutions, it is a challenging task to reduce 99Tc(VII)O4-. This study evaluated the reducing capacity of zero valent iron (ZVI) as a potential reducing agent in the CWT. Using perrhenate (Re(VII)O4-) as a chemical analogue for …
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Phytoplankton Ecology in the Skidaway River Estuary
… in abiotic factors such as salinity, nutrient concentration, and light availability strongly influence total phytoplankton biomass but less is known about their effects on species-level changes due to difficulties associated with identifying and enumerating individual taxa. Understanding …
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Comparative analysis of nitrate load estimation techniques in watersheds with different land-use characteristics
Water quality issues stemming from high nutrient concentration in water bodies are a commonplace in the United States (US) and all over the world. Nutrient loads in surface water can be estimated by monitoring their concentrations in the water bodies. The challenge is to determine the optimal data …
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Spatial and temporal water quality in the River Esk in relation to freshwater pearl mussels
… probe. Results revealed a number of concentration hotspots with values of nitrate that are thought unsuitable for freshwater pearl mussels. Other water quality variables were all within acceptable limits. Concentrations of nitrate in sub-catchments with smaller upstream areas proved …
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Natural abundance of ¹⁵N as a tool for assessing patterns of nitrogen loss from forest ecosystems
… of a site. Among ecosystems with contrasting nitrate loss patterns, the [delta]15 N of soil and plant material should be higher at sites with higher nitrate losses. An underlying assumption in natural abundance isotope studies is that soil [delta]15 N is at steady-state over time. I found that …
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The effect of sludge age and aerobic sludge mass fraction on low F/M filament bulking in intermittent aeration nitrogen removal systems
… of the aerobic mass fraction, • magnitude of the nitrate concentration during the anoxic period, on the low F /M filaments. The experimental set-up consisted of two intermittently. aerated anoxic-aerobic (20 minute cycles, peak DO 2 to 2,5 mgO/l), single reactor completely mixed continuously fed …
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Portable biomedical measurement devices: MoboSens and impedance sensing systems
… jack on the smartphone. It is used to measure nitrate concentration in water portably. The other method is called impedance sensing measurement. A portable device is used as the platform to combine with the impedance-based sensing technologies. It is designed to detect some species of …
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Novel studies of the dynamics of mineral N species transformations and their mobilities relevant to assessing risks to drainage water.
… nitrification has ceased, and that subsequently nitrate is immobilized when the drying period is protracted. It is suggested that this is probably due to uptake by drought-tolerant microorganisms. The experimental work showed that much of the first flush of nitrate after a period of drying is …
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Separation of Scandium and Calcium by Liquid-Liquid Extraction using Tri-N-Butyl Phosphate as Solvent
… Ca(N03)2- HNO3- TBP- H20 over a wide range of concentration of the metal nitrates in the aqueous solution. Equilibrium acid concentration was used as a parameter for the equilibrium curves.</p><p>For the system Sc(N03)3- Ca(NO3)2- HNO3- TBP- H20 the distribution coefficients of scandium and …
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A study of nitrification in lakes of the English Lake District
… by decreasing ammonium, and increasing nitrate, concentrations. In Grasmere lake this phase was found to be due to the activity of planktonic chemolithotrophic nitrifying bacteria. The observed nitrate concentration increased during this phase and accounted for up to 15% of the total …
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A universal miniaturized electrochemical sensing platform and its applications
… the sensing platform, which include measuring nitrate concentration and counting number of white blood cells. This inexpensive, portable device is also suitable for a variety of other applications, ranging from instant food/water quality examination to long-period environmental monitoring. We …
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Anaerobic transformations of Kepone by denitrifying bacteria
… by denitrifying bacteria grown on benzoate-nitrate medium. In enrichment cultures, Kepone was transformed more extensively than by pure cultures isolated from the enrichments. A gram negative-faculative rod, called K bacterium, transformed 8.8% of the Kepone in a benzoate-nitrate medium in …
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Cover Cropping: A Strategy to Healthy Soil and Nitrogen Management in Corn
… between soil health indicators, soil nitrate (NO3-N) and ammonium (NH4-N), corn N requirement and corn yield, and c) study the decomposition and N release of different cover crops. In a comparison of cover crop treatments, there was a trend of increasing permanganate oxidizable carbon …
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