We begin by recalling the notion of a coarse space as defined by John Roe. We show that metrizability of coarse spaces is a coarse invariant. The concepts of bounded geometry, asymptotic dimension, and Guoliang Yu's Property A are investigated in the setting of coarse spaces. In particular, we show that bounded geometry is a coarse invariant, and we give a proof that finite asymptotic dimension implies Property A in this general setting. The notion of a metric approximation is introduced, and a characterization theorem is proved regarding bounded geometry. Chapter 7 presents a discussion of coarse structures on the minimal uncountable ordinal. We show that it is a nonmetrizable coarse space not of bounded geometry. Moreover, we show that this space has asymptotic dimension 0; hence, it has Property A.Finally, Chapter 8 regards coarse structures on products of coarse spaces. All of the previous concepts above are considered with regard to 3 different coarse structures analogous to the 3 different topologies on products in topology. In particular, we see that an arbitrary product of spaces with any of the 3 coarse structures with asymptotic dimension 0 has asymptotic dimension 0.

A year-long study was conducted in Pinal County, Arizona to characterize fine and coarse particulate matter as a means of furthering our understanding of ambient concentrations and composition in rural, arid environments. Detailed measurement of ambient fine and coarse mass, ion, metal, and carbon concentrations at one-in-six day resolution was conducted at three sites from February 2009 to February 2010. Detailed organic carbon speciation was collected at 5-week resolution. A series of samples representing native soil, agricultural soil, road dust, and cattle feed lot material was collected, resuspended in the laboratory, and analyzed to provide a chemical source profile for each soil type yielding insights into unique source signatures. Observations within the chemical speciation data and subsequent modeling analysis show a strong impact from local sources at the Cowtown site where mass concentrations are highest. Source apportionment results confirm the significant impact from the cattle feedlot adjacent to the site. Chemical analysis of ambient particles and local feedlot material shows the presence of chemical marker species including phosphate which is unique to this source. Fugitive dust is a significant contributor to ambient particulate matter concentrations at all monitoring locations. Seasonal observations show higher concentrations during tilling and harvesting indicating the large role agricultural sources play on particle concentrations in this area. Chemical characterization and modeling show that re-entrained road dust is a significant factor. Fine particle modeling results indicate that concentrations are influenced significantly by motor vehicles including impacts from direct emissions including brake wear and indirect emissions including resuspended road dust. A significant fraction is also associated with crustal sources while about 5 g/m3 appears to be transported into the region from beyond the air shed. Detailed analysis of the local monsoon season indicates that monsoon rains serve to clean the atmosphere resulting in a marked decrease in ambient coarse mass and resulted in a period where local coarse PM concentrations measured at all sites became more uniform. The monsoon season also featured localized high wind events which severely increased coarse PM concentrations and often caused exceedences of the PM National Ambient Air Quality Standard.

A year-long study was conducted in Pinal County, Arizona to characterize fine and coarse particulate matter as a means of furthering our understanding of ambient concentrations and composition in rural, arid environments. Detailed measurement of ambient fine and coarse mass, ion, metal, and carbon concentrations at one-in-six day resolution was conducted at three sites from February 2009 to February 2010. Detailed organic carbon speciation was collected at 5-week resolution. A series of samples representing native soil, agricultural soil, road dust, and cattle feed lot material was collected, resuspended in the laboratory, and analyzed to provide a chemical source profile for each soil type yielding insights into unique source signatures. Observations within the chemical speciation data and subsequent modeling analysis show a strong impact from local sources at the Cowtown site where mass concentrations are highest. Source apportionment results confirm the significant impact from the cattle feedlot adjacent to the site. Chemical analysis of ambient particles and local feedlot material shows the presence of chemical marker species including phosphate which is unique to this source. Fugitive dust is a significant contributor to ambient particulate matter concentrations at all monitoring locations. Seasonal observations show higher concentrations during tilling and harvesting indicating the large role agricultural sources play on particle concentrations in this area. Chemical characterization and modeling show that re-entrained road dust is a significant factor. Fine particle modeling results indicate that concentrations are influenced significantly by motor vehicles including impacts from direct emissions including brake wear and indirect emissions including resuspended road dust. A significant fraction is also associated with crustal sources while about 5 g/m3 appears to be transported into the region from beyond the air shed. Detailed analysis of the local monsoon season indicates that monsoon rains serve to clean the atmosphere resulting in a marked decrease in ambient coarse mass and resulted in a period where local coarse PM concentrations measured at all sites became more uniform. The monsoon season also featured localized high wind events which severely increased coarse PM concentrations and often caused exceedences of the PM National Ambient Air Quality Standard.

Current advancements in nuclear reactor core design are pushing reactor cores towards greater heterogeneity in an attempt to make nuclear power more sustainable in terms of fuel utilization and long-term disposal needs. These new designs are now being limited by the accuracy of the core simulators/methods. Increasing attention has been given to full core transport as the flux module in future core simulators. However, the current transport methods, due to their significant memory and computational time requirements, are not practical for whole core calculations. While most researchers are working on developing new acceleration and phase space parallelization techniques for the current fine mesh transport methods, this dissertation focuses on the development of a practical heterogeneous coarse mesh transport method. In this thesis, a heterogeneous coarse mesh transport method is extended from two to three dimensions in Cartesian geometry and new techniques are developed to reduce the strain on computational resources. The high efficiency of the method is achieved by decoupling the problem into a series of fixed source calculations in smaller sub-volume elements (e.g. coarse meshes). This decoupling lead to shifting the computation time to a priori calculations of response functions in unique sub-volumes in the system. Therefore, the method is well suited for large problems with repeated geometry such as those found in nuclear reactor cores. Even though the response functions can be generated with any available existing fine-mesh (deterministic or stochastic) code, a stochastic method was selected in this dissertation. Previous work in two dimensions used discrete polynomial expansions that are better suited for treating discrete variables found in pure deterministic transport methods. The amount of data needed to represent very heterogeneous problems accurately became quite large making the three dimensional extension impractical. The deterministic method was thus replaced by a stochastic response function generator making the transition to continuous variables fairly simple. This choice also improves the geometry handling capability of the coarse mesh method.

Mining operations lead to considerable land disturbance and accumulation of large amounts of waste rock that may contain elevated concentrations of hazardous substances. Without proper capping, they may have considerable negative environmental impact on different spheres of the Earth. Capping of waste rock with a soil cover re-creates the water and nutrient regimes required for the growth of native plants and returns biological productivity and biodiversity of the land to a condition similar to that existing before site disturbance. In many cases the area of disturbance is composed of coarse-textured materials with low water retention properties, which are not desirable in semi-arid zones. This study was conducted to determine (1) whether a considerable increase of water storage is possible after separation of coarse-textured soil into size fractions and layering them in such a way that the finer fraction overlies the coarser fraction; and (2) whether such soil covers are susceptible to preferential flow under various initial and boundary conditions and what influence this type of flow has on residence time. Four types of soil covers were constructed in chambers: homogeneous covers composed of natural sand, two-layered covers with abrupt and gradual interlayer transitions, and four layered soil covers with abrupt transitions. Soil water storage was measured at field capacity (FC). Soil covers were tested under two types of lower boundary conditions: gravel layer and -25-cm matric potential. Flow stability was assessed during intermittent and constant ponded infiltrations. Water storage capacities (WSCs) for soil covers with -25-cm matric potential at the bottom of a cover were additionally simulated in HYDRUS-1D. Water storage capacities increased with the number of layers under both lower boundary conditions. Two-layered covers with a transition layer had slightly lower water storage than the same cover without the transition, due to a decreased hydraulic contrast at the layer interface. Simulated WSCs under -25-cm matric potential at the bottom were in satisfactory agreement with measured WSCs. The wetting front was stable in the homogeneous cover under both initially dry and FC conditions and in the two-layered cover with a gradual transition under initially dry water content during intermittent ponded infiltration. Unstable flow was observed only in the two-layered soil cover under both initial water contents. Other covers were partially unstable under initially air-dry and FC conditions. Generally, the wetting front was more diffuse at FC. Flow in all covers was stable under constant ponded infiltration. The residence time of water increased with the increase in the number of layers under both types of infiltration. Results of the study show that WSC and residence time do increase with increasing number of layers in soil covers, where layers are composed of different fractions of coarse-textured soil. In addition, tested soil covers have shown limited susceptibility to preferential flow even when layered into finer-over-coarser soil systems.

The environmental impact of bitumen mining in the Athabasca region of Canada is of growing concern. Among these concerns is the need and difficulty to remediate and reclaim affected land, including tailing sands (TS), a byproduct of the hot water extraction used to separate bitumen from solid materials. Current reclamation methods consist of multiple steps and take several decades to be effective. The primary reason for the difficulty in reclaiming disturbed land is the harsh environment found within the TS combined with the scale of the problem. TS are extremely nutrient poor, having below-detectable levels of NPK and extremely low C and S. In addition to this TS have pHs outside of environmental normals, and are hydrophobic due to residual hydrocarbons. Previously, an endophytic fungus, Trichoderma harzianum strain TSTh20-1, was isolated from pioneer plants growing naturally on TS sites, and was found to promote plant growth on TS. In my study TSTh20-1 was also found to increase the rate of drought recovery, and to enhance seed germination rates on a variety of soils. Suitable application methods were explored for this endophyte, including seed coatings, granules, as well as direct application to plant/soil. Regardless of method, TSTh20-1 was found to successfully colonize the plants. Twenty-four species of grasses, forbs, and legumes were tested for their ability to grow on TS. The four most successful species (Trifolium repens, Bouteloua gracilis, Medicago sativa, and Elymus trachycaulus) were put into a seed mixture for use in experiments. In mesocosm-scale experiments, plant health and soil parameters were measured after 2 months of growth. Hydrocarbon analysis of the first mesocosm showed a 2.7-fold increase in total hydrocarbons when TSTh20-1 and plants were present, suggesting degradation of large hydrocarbons beyond the scope of the analysis. A repeat experiment using a different source of tailings did not yield this same result. This is most likely due using a source of tailings that had substantially different chemical characteristics. TSTh20-1 was also analyzed for its ability to produce plant hormones or siderophores, to increase peroxidase enzyme activity, to protect plants from reactive oxygen species, and to solubilize phosphate precipitates from soil. All of these are known mechanisms microbes use to promote plant growth.

Thesis (doctoral)--Swedish University of Agricultural Sciences, 2008. / Includes reprints of four papers and manuscripts co-authored with others. Includes bibliographical references. Also partially available electronically via World Wide Web in PDF format; online version lacks reprints of four papers and manuscripts.

Thesis (M.S.)--Oregon State University, 1995. / Typescript (photocopy). Includes bibliographical references (leaves 78-83). Also available on the World Wide Web.

Zugl.: Freiburg (Breisgau), Univ., Diss., 2009

Thesis (M.S.)--Oregon State University, 1991. / Typescript (photocopy). Includes bibliographical references (leaves 84-90). Also available on the World Wide Web.