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Articles 1 - 5 of 5
Full-Text Articles in Physical Sciences and Mathematics
Seasonal Soil Carbon Fluxes In Transitioning Agricultural Soils In Central Washington State: Relations To Land-Use, Environmental Factors And Soil Carbon-Nitrogen Characteristics, Brandon Kautzman
All Master's Theses
Changing agricultural land-use practices to increase soil carbon sequestration contributes to climate change mitigation and improved food security by moving CO2 from the atmosphere into soil as soil organic carbon (SOC). In 2016, a farm in Thorp, Washington, Spoon Full Farm, began converting land historically farmed using conventional methods of tillage and synthetic fertilizers to conservation farming methods with direct seeding and organic soil amendments with a goal of sequestering carbon in the soil. This project evaluates relationships of soil CO2 respiration and net ecological exchange (NEE) with land-use types, seasonal environmental factors (air temperature, relative humidity, soil …
Effect Of Carbonaceous Nanoparticles On Naturally Occurring Iron Reduction By Carboxylates, Ashleen Reddy
Effect Of Carbonaceous Nanoparticles On Naturally Occurring Iron Reduction By Carboxylates, Ashleen Reddy
All Master's Theses
The emission of ambient particulate matter (PM) is regulated by many institutions due to the detrimental effects on health, environment and climate; yet many underlying mechanisms of PM reactivity are still not well understood. In the current study, the effect of carbonaceous nanoparticles (CNPs), contained within ultrafine PM (particle diameter ≤ 100 nm), is investigated on naturally occurring processes that increase the abundance of bioavailable iron. Enhancing iron bioavailability (i) increases primary productivity of iron-limited microorganisms, affecting the carbon cycle and global climate, and (ii) increase toxicity of inhaled particles through the associated production of reactive oxygen species (ROS). Specifically, …
Determination Of The Oxidative Capacity Of Soot Toward Gsh And Characterization Of Soot Physicochemical Properties, Kaylee Troth
Determination Of The Oxidative Capacity Of Soot Toward Gsh And Characterization Of Soot Physicochemical Properties, Kaylee Troth
All Master's Theses
Fine atmospheric particulate matter (PM2.5) emitted during the combustion of fossil and biomass fuels is known to adversely affect human health. While the underlying mechanisms are thought to be driven by the generation of reactive oxygen species (ROS), specific particle characteristics responsible for this detrimental effect are not well understood. In this research, the quantitative determination of the biologically relevant antioxidant, glutathione (GSH), was optimized for use as an indicator of oxidative stress to shed light on relevant particle characteristics. This was accomplished via fluorescent spectroscopy for GSH determination by way of reaction with o-phthalaldehyde (OPA), a …
Bioavailable Iron In Equatorial Pacific Ocean Aerosol Samples, Hsiang T Teng
Bioavailable Iron In Equatorial Pacific Ocean Aerosol Samples, Hsiang T Teng
All Master's Theses
Oceanic iron (Fe) fertilization experiments performed in remote regions have established that Fe additions draw carbon into the ocean, at least over the months-long time frame of the experiments. However, the mechanisms that control Fe speciation in atmospheric aerosol particles before and after deposition into the surface ocean remain largely unknown. This is in part due to the analytical challenge of quantifying Fe at environmentally significant sub-nano molar levels. The flow injection analysis method combined with the luminol chemiluminescence analytical system allows us to explore the near-real time determination of pico-molar levels of both Fe(II) and H2O2 …
The Effects Of Herbicides On Three Soil Inhabiting Blue Green Algal Species, Lee C. Darlington
The Effects Of Herbicides On Three Soil Inhabiting Blue Green Algal Species, Lee C. Darlington
All Master's Theses
The object of this study was to examine the effects of varying concentrations of 2, 4-D, Dalapon, and Tordon on the growth of several nitrogen-fixing blue-green algal species obtained from soil samples and grown under culture conditions in the laboratory.