A plume of process-affected groundwater was identified in a shallow sand aquifer adjacent to a tailings impoundment at Syncrude Canada Ltd. Quantitative and qualitative Naphthenic Acid (NA) analyses were performed on groundwater samples to investigate NA fate and transport properties in the subsurface. Analysis of dissolved organic and inorganic components was undertaken to identify, quantify and assess the mobility of other dissolved components of environmental significance. NAs at concentrations up to 87 mg/L were found to represent the major contributor to aquatic toxicity. Attenuation of NAs by biodegradation is not observed based on screening techniques developed to date. Retardation of NAs observed at the field scale, is consistent with weak sorption observed in the laboratory by other authors. Concentrations of ammonium approached 4 mg/L in the plume, however mobility is limited by cation exchange. Aromatics and trace metals are present in low quantities (i. e. <10 µg/L) and are only detected in groundwater immediately adjacent to the toe of the tailings impoundment. Cl and Na are found at concentrations of up 282 and 579 mg/L respectively. Dissolved oxygen is typically < 1 mg/L within the plume, while redox indicators Mn(II), Fe(II) and methane are detected between <0. 1 - 2. 6, 0. 2 - 3. 5 and <0. 1 - 2. 1 mg/L respectively within the plume. Solid phase geochemistry, determined through solid phase extractions, was coupled with aqueous geochemistry and reactive transport modeling to identify the dominant geochemical processes occurring within the plume. Based on scenarios evaluated using reactive transport modeling, the most likely origin for the presently observed, weakly reducing conditions in the plume appears to be the presence of a small amount of disssolved, degradable organic carbon. The dominant terminal electron acceptors appear to be Fe(III) and Mn(III/IV) in the plume core and dissolved oxygen at the plume fringe. Dissolved Fe and Mn are observed to enter the domain at the upgradient boundary at maximal concentrations of 4. 2 and 0. 7 mg/L respectively. Trace metal geochemistry of the aquifer material was also assessed using solid phase extractions. The potential for trace metal release via reductive dissolution of the native geologic material is considered minimal in this case, based on the weakly reducing nature of the plume and a lack of excessive trace metal content in the aquifer material.

Albertas oil sands are located in the boreal forest where surface mining disturbs huge tracts of land. One such area, Syncrude Canada Ltd.s Mildred Lake mine, contains waste overburden (OB) piles which can be saline and sodic (SSOB). The objectives of this research were to 1) determine SSOB material impacts on planted tree root distributions, 2) quantify root activity to identify plant species growing at depth, and 3) document coarse woody root structure for planted trees. Root distributions for three mixedwood stands on reclaimed OB in relation to electrical conductivity (EC) and sodium absorption ratio (SAR) were examined using soil cores. Root distributions followed a similar pattern with soil depth as those from undisturbed boreal forest stands and appeared unaffected by the SSOB at this stage; however, future monitoring will be required as the stands mature. Root activity was assessed for jack pine (jP) and white spruce (wS) stands on tailings sand (TS) and OB using a strontium (Sr) chloride tracer. Understory and tree foliage was collected prior to and after application to measure Sr concentration in the control, broadcast, and depth treatments. A small proportion of roots grew in the OB material regardless of its chemical properties. Results from the Sr tracer study suggested that these roots were probably from the clover, sow thistle, and grasses. Planted trees showed little to no change in Sr tissue content suggesting that there were little to no roots in the treatment zones, the understory species out-competed the trees for Sr accessibility, or the tracer was diluted in the tree biomass to undetectable levels. Root systems of planted jP trees older than 10 years and older than 20 years on TS and OB were excavated and the number and diameter of lateral roots, the degree of kinking and coiling, and the presence of a taproot were recorded. Excavated trees showed poor taproot development on 70% of the trees and numerous root deformities, suggesting that more emphasis is needed in correct planting techniques and good planting stock to ensure proper root development. Roots are critical components of boreal forest ecosystems; without healthy root systems productivity may decline, stands may be susceptible to windthrow, and general forest health may suffer.

Syskonbädd, or “Sibling’s bed” in English, is a short story or drama, written by Swedish author Stina Aronson and originally published in 1931 under the pen name Sara Sand. While the story did not attract wide attention for many years, it has recently been republished and performed on stage, as well as aired on the radio. The plot is centered on Harriet, a woman who starts to see the world with different eyes, in a less strict and organized way. Her new view is welcomed neither by her husband nor society, and the book starts with Harriet’s escape from a “rest home”, where she has been placed by her husband in order for her to return to her old self. During the escape, Harriet meets several people, some like herself who believe that the world was meant to be different, and some who strive to maintain the social structure.  Swedish literature scholar Eva Adolfsson argues that Aronson’s later works take place in a landscape on the border of the wild, and that both the characters and the story move through such a landscape. I believe that this is also the case for Syskonbädd, one of Aronson’s earlier writings. My essay focuses on the momentum in the book, its double nature, the zone of uncertainty that it creates and the possibilities that it presents. Based on this, my thesis is that the idea of a “sibling’s bed” solidarity is a formula that drives the book; it is the engine for all movements. With a starting point in philosopher Gilles Deleuze’s and psychoanalyst Félix Guattari’s theories about literature, philosophy and art, I follow and analyze these different movements; the lines of flight that dissolve and create chaos, as well as the plane of consistency that holds the work together and on which the chaos is visualized. These structural movements constitute my starting point for an analysis also on a hermeneutical level. Harriet escapes from society and from the norms that it enforces. At the same time, she seeks a new kind of community; a connection beyond knowledge that will allow new sensations. In this aspect, the outer movement of escape leads to another kind of motion, a static one, which may take place between people when they meet under such circumstances.

Aeolian sand transport models, widely employed by coastal scientists and managers, assume temporal and spatial homogeneity within the saltation field. This research questions that assumption by demonstrating that the saltation field is event-driven, therefore indicating that the saltation field is not temporally steady. The findings from this research may explain a portion of the conclusions from previous studies that indicated inequalities between model-estimated and field-measured aeolian sand transport. The relationship between unsteadiness in a turbulent wind field and pulses in a sand transport field was investigated on a beach near Shoalhaven Heads, New South Wales, Australia. Microphone-based saltation sensors, “miniphones,” and thermal anemometers (both instruments constructed exclusively for this field experiment) were co-located (0.02 m separation on center) and deployed between 0.01 and 0.0225 m above the bed, and sampled at 6000 Hz. Average grain size at the field site was 0.30 mm. Five runs totaling 2050 seconds of wind and saltation data were analyzed. The continuous wavelet transform, using the Morlet wavelet base, was the principle method for analyzing the wind and saltation records. The cross continuous wavelet transform was used to analyze the wind and saltation time series concurrently. Wind, saltation, and cross events were discerned by selecting wavelet power coefficients between wavelet scales of 0.4 and 3.0 seconds and with coefficients exceeding the 95% confidence interval. Average event spacing was 6.10, 6.50, and 6.73 seconds for the wind, saltation, and cross events, respectively. The average event spacing measured in this research was compared to the empirical-based model presented by Rao, Narashimha, and Narayanan (1971). The correspondence between the model and this research strongly suggests that bursting-type coherent structures were present. The durations of average wind, saltation, and cross events were 1.87, 2.10, and 1.73 seconds, respectively. Integral time scales, calculated using normalized auto correlation and power spectral density analysis, were approximately two seconds for the wind and saltation systems. The temporal coincidence of the integral time scale estimations and the event durations for the wind and saltation system strongly suggests that wind events are driving sand transport events.

Leishmaniasis is caused by infection with protozoan parasites within the genus Leishmania and, in the New World, is transmitted by the bites of female sand flies within the genus Lutzomyia. The occurrence of leishmaniasis in rodent species, the geographic distribution of sand fly species in Nicaragua, and environmental factors associated with the distribution of human cases of typical cutaneous leishmaniasis were investigated. Three hundred ninety five rodents representing 17 species were collected from 13 localities from August 2001–March 2006 and screened for Leishmania infections. One Heteromys desmarestianus and one Peromyscus mexicanus were found to be positive for leishmanial infections by PCR. This is the first report of Leishmania infections in rodents in Nicaragua. Five hundred fifty six sand flies representing 12 species were collected from 8 localities, including Lutzomyia hartmanni, a new record for this species in Nicaragua. The predominant sand fly species captured in western Nicaragua were Lutzomyia longipalpis and Lutzomyia evansi. The predominant species captured in central and eastern Nicaragua was Lutzomyia cruciata. The geographic distribution of sand flies in this study provides additional support to previouslypublished reports of suspected vectors of Leishmania species that cause typical and atypical forms of cutaneous leishmaniasis in Nicaragua. Distribution data of human cases of typical cutaneous leishmaniasis obtained from the Nicaraguan Ministry of Health, along with GIS and remotely sensed data of elevation, precipitation, temperature, soil types and land use/cover classes, were used to develop predictive logistic regression models for the presence or absence of human cases within 151 municipalities. Mean annual precipitation and land use/cover were determined to be the best environmental variable predictors for the occurrence of typical cutaneous leishmaniasis.

Thin polyurethane films have been widely used as erosion-resistant coatings on helicopter rotor blades. Published research has mainly focused on empirical studies that relate the mechanical properties such as rebound resilience and hardness of polyurethane to solid particle erosion resistance. However polyurethane possesses phase mixing at multiple scales and thus sand particle erosion resistance depends also on the micro structure and the phase mixing. Hence, it is very important to carry out detailed and systematic investigations to understand the step-by-step mechanism of erosion and how it relates to the polyurethane micro, meso, and macrostructure. Thermal transitions of the pristine films have been studied through Differential Scanning Calorimetry (DSC) and Dynamic Mechanical Analysis (DMA) yielding micro-scale information such as glass transition temperatures of the hard and soft segments and melting temperature of the soft segment. The next stage of our study involved sand particle erosion tests carried out at 500 mph, at an impact angle of 30 degrees. Test specimens were exposed to two different sand media at different mass loadings ranging from 0.1 to 20 g/cm^2. The tools of characterization used on the pristine polyurethane are once again used on the eroded specimens, with the goal to compare pre- and post- erosion results. The comparison of FTIR results on pre-eroded and eroded films reveal the removal of macromolecular bonds corresponding to soft segments in the micro scale. The reduction of the crystalline portion of the soft segment observed from DSC results supports the FTIR findings. Scanning electron microscopy (SEM) images of the eroded specimens are used to correlate the sequence of the damage due to erosion. The observations revealed that after initial ductile deformation of the soft segments on the surface, brittle cracks are formed on the hard segments. The increased exposure to sand particles leads to formation of fragments containing mainly soft segments with cracks in the hard segments propagating in a brittle manner. As exposure increases, cracks intersect and material on the surface gets removed which mainly contains the soft segments as revealed by the FTIR and DSC results.

In many regions of the world, groundwater is contaminated with a high level of arsenic that must be treated before it can be safely used as drinking water. In situ immobilization of arsenic from groundwater within subsurface environment could have major advantages over the conventional above-ground chemical coagulation-precipitation treatment process. In this study, we develop a novel technique that can in situ emplace iron oxides onto the sand grain surface of porous media under mild chemical and temperature conditions. The technique involves sequential injections of a preconditioned ferrous iron solution and an oxidant solution and then orchestrate the advective-diffusive transport of the two reagents in porous media to create an overlapped reaction zone where ferrous iron is oxidized and precipitated on the sand grain surfaces. We demonstrate through bench-scale column tests the feasibility of using this technique to create a large-scale iron oxide-enriched reactive barrier in subsurface environment for in situ removal of arsenic. A sand filter with a fresh iron oxide coating can treat thousands of pore volumes of water contaminated with dozens of ppb arsenic before the coating needs to be regenerated. Arsenic breakthrough curves through the sand filter suggest that both reversible adsorption and irreversible precipitation are responsible for removing arsenic from the water. Unlike conventional excavate-and-fill permeable reactive barriers, the treatment capacity of our in situ created barrier can be in situ regenerated and replenished with a fresh coating.

The modeling of Sand Asphalt and experiments to measure their rheological properties are of vital concern to many industrial processes especially highway and roadway pavement construction industry. A variety of hot mix asphalt mixtures are used in highway and runway pavement construction, with each mixture catering to a specific need. These mixtures vary in type and percentage of aggregates and asphalt used and consequently exhibit marked differences in their response. The main thrust of this research is to provide experimental data which would be helpful in determining the efficacy of the constitutive models that have been developed for these hot mix asphalt mixtures. Here we attempt to provide experimental data in the raw form for Sand Asphalt mixtures that would be helpful in the theoretical modeling efforts involving asphalt materials using a continuum point of view. For example the data obtained can be of immense help to evaluate the constitutive model developed by Murali Krishnan and Rajagopal. The Sand Asphalt mixture in their model is modeled as `homogenized' single constituent due to the peculiarity of its makeup. The constitutive model of Murali Krishnan and Rajagopal is based on a thermodynamical framework for materials possessing multiple natural configurations (multiple stress free states) to derive the constitutive equations. Recently an Orthogonal Rheometer was built to characterize the granular solids by Gupta and Rajagopal which was later used by Baek in the torsional mode. In this work we have used the same Torsional Rheometer with some minor modifications in the design to measure some general properties of Sand Asphalt mixtures. Sand Asphalt mixtures, due to their non-linear viscoelastic character, exhibit `normal stress effects' and `stress relaxation'. The Rheometer that we used was able to capture these responses with high precision. We have laid out proper procedures for the further testing of asphalt related mixtures. A typical sand asphalt mixture sample in cylindrical shape was used as the test specimen. From this work some interesting data was obtained. A remarkable observation was that as the shear rate is increased, the normal force and torque generated initially decrease, but beyond a certain shear rate they attain a constant value.

Remote sensing reflectance data collected with a remotely operated vehicle (ROV) were used to derive bottom albedo and optical properties for a shallow marine environment near Lee Stocking Island, Bahamas. Optical model inversion techniques were applied to hyperspectral measurements of remote-sensing reflectance to derive water absorption and backscatter coefficients. Using these derived water properties, path attenuation and radiance effects were removed from bottom observations to derive bottom albedos. Histograms from multispectral, hyperspatial video images were used to determine the albedo range of optical end members observed in scenes of sand and seagrass. Variations of spectral signatures for optical end members caused by path-adjacency effects are shown to influence the reflectance measurements. Low-altitude albedo histograms for heterogeneous scenes demonstrate higher contrast between sand and seagrass than is observed at higher altitudes, even after correction for path radiance and attenuation effects. For example, reflected light from bright sand scatters into the field of view of dark seagrass, while less light scatters out from the seagrass into the field of view of sand. This decreases the apparent sand albedo, and increases that for seagrass when viewed from higher altitudes, including aircraft. Evidence provided suggests that simple bottom classifications based upon expected albedo values for scene end members are in error unless the water depth is very shallow.

Particle-laden flows occur in a variety of natural and industrial situations. As particulate suspensions flow through a medium, particles are often retained at constrictions such as pore throats, outlets or orifices. This occurs not only with oversized particles, but also with particles smaller than the constriction. For instance, jams are caused by the formation of particle bridges/arches when several particles attempt to flow through a constriction simultaneously. In many instances the success of an operation depends on our ability to either ensure or stop the flow of particles in the flow stream. Managing the flow of sand into wellbores during hydrocarbon production from poorly consolidated sandstone reservoirs, also referred to as sand control, is one such application in the oil and gas industry. This dissertation presents a multi-pronged effort at modeling the flow of granular suspensions of different concentrations, and through pore openings of different shapes, with two main objectives: (1) predicting the mass and size-distribution of the particles that are produced before jamming, and (2) investigating the underlying factors that influence the onset and stability of particle arches. Since, the dominant interactions and retention mechanisms are concentration dependent, we divided particulate suspensions into three groups based on the volumetric particle concentration ([phi]). High-concentration suspension flows ([phi]>~50%) are dominated by particle-particle interactions. We modeled polydisperse sand packs flowing through screens with rectangular and woven-square openings using 3D discrete element method (DEM). Simulations were validated against experimental data for a wide range of screen opening and sand size distributions. From the experiments and DEM simulations, a new scaling relation is identified, in which the number of different sized particles produced before retention follows a power-law correlation with the particle-to-outlet size ratio. This correlation is explained with a simple probabilistic model of bridging in polydisperse systems and a particle-size dependent jamming probability calculated from experimental data. A new method is presented to estimate the mass and size distribution of the produced solids through screens. The method uses the entire particle size distribution (PSD) of the formation sand, is validated with experimental data and numerical simulations, and provides more quantitative and accurate predictions of screen performance compared to past methods. It is also found that the stability of particle arches is compromised when adjacent outlets are less than three particle diameters away from each other. Low-concentration suspension flows ([phi]<~1%) are dominated by particle-fluid interactions. They were modeled using analytical and stochastic methods to predict sand production through screens with slot and woven-square openings. Analytical expressions were derived for screens with a constant outlet size or with a known outlet size distribution. Monte Carlo simulations showed excellent agreement with the analytical solutions. Based on experiments, we have demonstrated that the models presented here are predictive, provided that an accurate representation of the formation sand PSD and the screen pore size distribution are available. In the intermediate-concentration regime (~1%<[phi]<~50%), the particle trajectories and the flow field are both influenced by each other. The onset of particle bridging due to hydrodynamic forces was studied for monodisperse systems, in a rectangular channel with a single constriction, using coupled computational fluid dynamics (CFD) and DEM simulations. It is shown that the probability of jamming increases with [phi], and there is a critical particle concentration ([phi, superscript asterisk]) for spontaneous bridging. The outlet-to-particle size ratio is the most critical parameter affecting [phi, superscript asterisk]. The effect of inlet-to-particle size ratio, fluid velocity, particle stiffness, particle-to-fluid density ratio, and the effect of convergence in flow geometry were also studied quantitatively. Finally, the application of micro-tomography images in constructing accurate 3D representations and calculating the pore size distribution of complex filter media is demonstrated. A simulation tool is presented that allows one to evaluate the performance of different screens without running expensive and sometimes inconclusive experiments, and enhances our understanding of screen performance. This helps to improve sand screen selection to meet performance criteria under a wide variety of conditions. / text