Nitrous oxide is an important greenhouse gas that has both natural and anthropogenic sources in the modern atmosphere (Ciais et al., 2013). This project expanded the knowledge of the history of atmospheric N2O in the geologic past by measuring N2O concentrations in air trapped in very old polar ice. A...
Nitrification is a critical step in the global nitrogen cycle involving the biological oxidation of ammonia (NH₃) to nitrite (NO₂⁻ ) and then to nitrate (NO₃⁻). The first step in nitrification is carried out by NH₃-oxidizing bacteria (AOB) and archaea (AOA), and the second by NO₂⁻-oxidizing bacteria (NOB). In addition...
This dissertation addresses gaps of knowledge associated with how ecosystem carbon stocks and greenhouse gas emissions are affected by land use land cover change in tropical peatlands. This was the first study that paired peat swamp forests with oil palm plantations and analyzed site scale variation on greenhouse gas emissions....
Exposure to urban outdoor air pollution is ubiquitous and low birth weight represents an important health disparity in the United States. While previous research suggests that exposure to outdoor air pollutants are associated with term low birth weight, few studies have evaluated the effects of multipollutant outdoor air exposures or...
The three studies that comprise this dissertation seek to answer significant
questions in paleoclimatology through unconventional applications of ice core
greenhouse gas data. These studies involve different gases and span the interval of time
between the Last Glacial Maximum and the Industrial Revolution, but are united by their
nontraditional use...
Emissions of oxides of nitrogen from a small (15 kW) turbine generator burning high fuel bound nitrogen fuels were measured by a chemiluminescence method. Kerosene was used as the base fuel and pyridine was added to achieve different fuel bound nitrogen levels. Mixtures of 0.0%, 0.5%, and 1.0% (by weight)...