Microplastics (MPs) are plastic particles less than 5 mm in diameter. These contaminants are increasingly found in the environment due to increased plastic production, use, and improper disposal. Detecting and measuring these contaminants in the environment has proven difficult, requiring the use of fate and transport models to assess MP...
Hyporheic zones are important regions that reside below and along the sides of streams. Within this region, several ecosystem services are provided including stream temperature regulation, habitats for a large variety of species, pollutant removal, and nutrient cycling. Exchange between the hyporheic zone and stream occurs across multiple scales, but...
In Oregon perennial and annual grass seed cropping systems conservation management practices and their impacts on soil health and soil microbial community is not well understood. There is strong motivation to employ conservation tillage and other conservation practices to curb atmospheric carbon levels and improve soil health. However, the few...
Phytophthora ramorum is the causal agent of Sudden Oak Death (SOD), which is an economically and environmentally important disease causing up to 80% mortality of tanoaks in Pacific Northwest coastal forests (LeBoldus et al., 2022). There are currently four clonal lineages in the United States and Europe, named North America...
This thesis presents an experimental study of radial porosity in a manually filled cylindrical container with glass spheres. The symmetric distribution of bead diameter allowed for normalization of container properties and porosity models. The aspect ratio of the container was approximately 3.9, with tube-to-particle-diameter ratio λ ≈ 24.6 and height-to-particle-diameter...
Per- and polyfluoroalkyl substances (PFAS) are a broad class of anthropogenic chemicals characterized by highly stable carbon-fluorine (C-F) bonds. PFAS are widely used in industrial and consumer products for their surface-active and stain-resistant properties and are ubiquitously detected in environmental media, biota, and human biomatrices. Although some PFAS are known...
It is considered best practice when designing pedestrian access at intersections to provide two curb ramps at each street corner. In Oregon, there are many locations where long ramp runs cause curb ramps to be set back a significant distance from the apex of the intersection corner to meet this...
(Polycyclic aromatic hydrocarbons) PAHs are widespread in the environment, and are derived from both natural and anthropogenic sources. The physicochemical properties of PAHs along with the wide range of PAH sources leads to their persistence in the environment. Since PAHs are ubiquitous, and have the potential to illicit adverse effects,...
Atmospheric carbon reduction is arguably the most crucial facet among efforts to mitigate climate change. The Fifth International Panel of Climate Change report emphasizes a worldwide goal of maintaining global temperature elevation less than 1.5°C above pre-industrial temperatures. This report also acknowledges without the proper utilization of counteractive emission strategies...
The cometabolic ability of Burkholderia vietnamiensis G4 grown on aromatic substrates was first assessed by resting suspended cells, and subsequently for cells encapsulated with and without slow release compounds (SRCs). In Chapter 3, benzyl alcohol was assessed as a food-grade growth substrate for promoting cometabolism of trichloroethene (TCE), via the...