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<p>The complex nature and composition of regolith cover in Southern Africa is a major challenge to geochemical mapping for concealed mineralization. Some of the setbacks to successful geochemical exploration may be ascribed to the use of various partial extraction techniques,without a profound understanding of the regolith components and their composition. This investigation therefore focuses on the use of hydroxylamine partial extraction geochemistry for geochemical mapping in regolith over two contrasting environments viz / aeolian sand-calcrete regolith over Au mineralization at Amalia Blue Dot Mine in South Africa and lateritic regolith covering the Ni-Cu deposit at Kabanga Main and Luhuma in Tanzania. Regolith samples from the above areas were sieved and extracted with hydroxylamine hydrochloride solution and analyzed for multi-element by AAS and ICP-MS techniques. A stepwise optimization of the hydroxylamine extraction technique of samples from both areas was carried out and incorporated into the analytical programme (in a pilot study). Results of hydroxylamine partial extraction generally gave better anomaly contrast and reflection of bedrock mineralization than the conventional aqua regia techniques that were previously used in the region. The results however show that lateritic regolith may be best extracted using 0.25M hydroxylamine while 0.1M concentration appears most suitable for extraction of aeolian-calcrete regolith. The above results are corroborated by principal component analysis of the analytical data that show various element associations, e.g. with Fe-Mn oxides while others possibly belong to the loosely adsorbed or exchangeable group. The&nbsp / gochemical maps in the pilot study areas at Amalia, Kabanga and Luhuma show elevated element contents or clusters of anomalies of diverse elements associated with Fe-Mn oxides. Geochemical mapping at Kabanga with deeply concealed mineralization however shows variability of subdued element patterns over mineralized areas. Geochemical signatures associated with hydroxylamine hydrochloride partial leach are therefore characterized by a lower geochemical background than that using conventional aqua regia leach. This study leads recommending for further investigations into partial extraction of the exchangeable group of elements, possibly using ammonium acetate.</p>

The purpose of this study was to develop management guidelines to ensure the long term ecological sustainability of the beach and sand dune area of Grand Beach Provincial Park. A qualitative approach was taken including interviews of individuals who use Grand Beach. A literature review was completed describing the history of use at Grand Beach Provincial Park, ecological processes specific to the park, and management guidelines in other jurisdictions in Canada with similar natural features. Aerial imagery provided a temporal look at intensely used areas in the park. Recommendations include: 1) completion of a biophysical study of the park including an inventory of flora and fauna species 2) development of a monitoring plan incorporating the natural environment with the human dimension of the park 3) engagement of park visitors through signage, education and awareness, and 4) engage the scientific community to form partnerships for further research studies in the park.

The topic of this thesis is the romantic "promenade" as a literary theme in the works of two 19th century authors: Gerard de Nerval and George Sand. / We have used Rousseau's Reveries du promeneur solitaire as foundation text in our research. Our corpus is comprised of two works by Gerard de Nerval: Sylvie and Promenades et Souvenirs, as well as George Sand's Lettres d'un voyageur; included also are some exerpts of her Correspondance. / We discovered that the experience of Nerval's "promenade" equates to a quest for the past, for freedom and for Nature. He also seeks to escape mental sickness, the burden threatening his inspiration. / In George Sand's works, the "promenade" becomes an activity allowing one to overcome familial and sentimental chagrin, a means of regaining a taste for life. / In the conclusion we compared the characteristics of the theme as illustrated by both authors, and brought to light their respective peculiarities.

The mixed sand and gravel barrier beaches located on the South Island's East Coast are formed predominantly of Greywacke, eroded from the mountains, and transported via the major river systems. These barriers act as the interface between the South Pacific Ocean and the surrounding hinterland. In times of high energy coastal events, breaching is common. This thesis examines the form and function of the Waihao-Wainono barrier, a section of the coastline situated north of the Waitaki River. Breaches along this part of the barrier are frequent and several have rendered the surrounding farmland unusable for several years due to the effects of saltwater inundation. There is some concern among the local community as to exactly why the barrier breaches at certain locations and not others, making land planning and management a difficult task for farmers. Several of the local landowners believe that since the construction of the Waitaki Dam in 1935, a significant decrease in sediment size along the barrier has occurred. It is also thought that the barrier form has experienced substantial change. Through the use of physical techniques used in the field of coastal science, 17 sites along the Waihao-Wainono barrier were studied. Excavations were carried out, surface and substrate profiles recorded and sediment samples collected from the surface. sub-surface and substrate of the barrier. Analysis of the barrier form and barrier volume concluded that the past breach sites consisted of steeper lower foreshore slopes than the non-breach sites, and at two sites, the substrate was not reached. Breach areas display the greatest barrier volume of all the study sites, which is contrary to belief. In relation to the surface sediments, the majority of barrier profiles displayed the distinct mean grain size cross shore zonation, characteristic of mixed sand and gravel beaches. The best and most consistent surface sorting was also identified as being a characteristic of the breach sites. The sediment size is not shown to have drastically reduced over the thirty year sampling period as was perceived by the local community. Within the sub-surface of the barrier, the sediments displayed chaotic sizes and generally poorly sorted material. Several of the breach sites contained a distinct change in sediment size between the coarser surface layer and the finer layer located immediately below. This layering of coarse and fine sized sediments leads to differences in permeability within the barrier, which is thought to be a major factor in why these sites have breached. Resulting from these findings, a group of characteristics of breach sites was formed and several predictions made as to where the barrier may breach in the near future.

This research aimed to address the knowledge gaps in the literature regarding the removal of waterborne pathogens (viruses and protozoa) by modified multistage slow sand filtration. In the current study, two pilot-scale multistage slow sand filtration systems were operated continuously for over two years. The pilot systems treated agricultural- and urban-impacted raw river water of variable quality with turbidity peaks over 300 NTU and seasonal cold temperatures <2??C. The first system (Pilot 1) consisted of two independent trains that included pre-ozonation, shallow-bed upflow gravel roughing filtration, and shallow-bed slow sand filtration. Pilot 1 was a pilot-scale version of an innovative, commercially available full-scale system. The second system (Pilot 2) included a full-depth upflow gravel roughing filter, a full-depth slow sand filter, and a second shallow-depth slow sand filter in series. The SSFs of both pilots were operated at high hydraulic loading rates (typically 0.4 m/h) at the upper limit of the literature recommended range (0.05 to 0.4 m/h). Both pilot systems provided excellent turbidity removal despite the high filtration rates. Effluent turbidity of all multistage SSF pilot systems were within the regulated effluent limits in Ontario for full-scale SSFs (below 1 NTU at least 95% of the time and never exceeded 3 NTU), despite raw water turbidity peaks over 100 NTU. The roughing filters contributed to approximately 60-80% of the full-train turbidity removal, compared to and 20-40% for the slow sand filters. On average, the second slow sand filter in pilot 2 provided almost no additional turbidity removal. The slow sand filter run lengths were short because of frequent high raw water turbidity, with about 50-80% of the runs in the range of 1-3 weeks. To prevent excessive SSF clogging and maintenance, filtration rates should be decreased during periods of high turbidity. Seven Cryptosporidium and Giardia challenge tests were conducted on the slow sand filters of both pilot systems at varying filtration rates (0.4 or 0.8 m/h), temperatures (2 to 25??C), and biological maturities (4 to 20 months). Removal of oocysts and cysts were good regardless of sand depth, hydraulic loading rate, and water temperature in the ranges tested. Average removals in the SSFs ranged from 2.6 to >4.4 logs for Cryptosporidium oocysts and ranged from >3.8 to >4.5 logs for Giardia cysts. This was consistent with findings in the literature, where oocyst and cyst removals of >4 logs have been reported. Cryptosporidium oocyst removals improved with increased biological maturity of the slow sand filters. At a water temperature of 2??C, average removal of oocysts and cysts were 3.9 and >4.5 logs, respectively, in a biologically mature SSF. Doubling the filtration rate from 0.4 to 0.8 m/h led to a marginal decrease in oocyst removals. Sand depths in the range tested (37-100 cm) had no major impact on oocyst and cyst removals, likely because they are removed primarily in the upper section of slow sand filter beds by straining. In general, good oocyst and cyst removals can be achieved using shallower slow sand filter bed depths and higher filtration rates than recommended in the literature. There are very few studies in the literature that quantify virus removal by slow sand filtration, especially at high filtration rates and shallow bed depths. There are no studies that report virus removal by slow sand filtration below 10??C. As such, 16 MS2 bacteriophage challenge tests were conducted at varying water temperatures (<2 to >20??C) and filtration rates (0.1 vs. 0.4 m/h) between February and June 2006 on biologically mature slow sand filters with varying bed depths (40 vs. 90 cm). Biologically mature roughing filters were also seeded with MS2. Average MS2 removals ranged from 0.2 to 2.2 logs in the SSFs and 0.1 to 0.2 logs in the RFs under all conditions tested. Virus removal by slow sand filtration was strongly dependant on hydraulic loading rate, sand depth, and water temperature. Virus removal was greater at a sand depth of 90 cm vs. 40 cm, at an HLR of 0.1 m/h vs. 0.4 m/h, and at warm (20-24??C) vs. cold (<2-10??C) water temperatures when sufficient warm water acclimation time was provided. Increased sand depth likely increased MS2 removal because of greater detention time for predation and greater contact opportunities for attachment to sand grains and biofilms. A lower HLR would also increase MS2 removal by increasing detention time, in addition to decreasing shear and promoting attachment to filter media and biofilms. Greater MS2 removal at warmer water temperatures was attributed to improved biological activity in the filters. Schmutzdecke scraping was found to have only a minor and short-term effect on MS2 removals. Virus removal can be optimized by providing deep SSF beds and operating at low filtration rates. Virus removal may be impaired in cold water, which could affect the viability of using SSF/MSF at northern climates if communities do not use disinfection or oxidation. As a stand-alone process, slow sand filtration (with or without roughing filtration) may not provide complete virus removal and should be combined with other treatment processes such as disinfection and oxidation to protect human health.

The purpose of this study was to develop management guidelines to ensure the long term ecological sustainability of the beach and sand dune area of Grand Beach Provincial Park. A qualitative approach was taken including interviews of individuals who use Grand Beach. A literature review was completed describing the history of use at Grand Beach Provincial Park, ecological processes specific to the park, and management guidelines in other jurisdictions in Canada with similar natural features. Aerial imagery provided a temporal look at intensely used areas in the park. Recommendations include: 1) completion of a biophysical study of the park including an inventory of flora and fauna species 2) development of a monitoring plan incorporating the natural environment with the human dimension of the park 3) engagement of park visitors through signage, education and awareness, and 4) engage the scientific community to form partnerships for further research studies in the park.

Recent research has revealed that quasi-instantaneous turbulent Reynolds stresses (RS, -u’w’) and decomposed ‘quadrant’ activity (e.g., ejections and sweeps) over dunes in fluvial and wind tunnel studies has shown that turbulent stresses at the toe of a dune often exceed time-averaged, streamwise shear stress (u*2) estimates. It is believed that semi-coherent turbulent structures are conveyed toward the bed along concave streamlines in this region, and these activities cause fluctuations in local surface stresses that assist in grain entrainment. This study focuses on event-based landform scale interactions between turbulent airflow and sediment transport over a vegetated foredune through the assessment of two different experiments that took place at Greenwich Dunes, Prince Edward Island National Park, P.E.I., Canada. Reynolds decomposition of quasi-instantaneous fluctuating u’ and w’ signals into quadrant (Q) activity (i.e., Q1 outward interactions: u’>0, w’>0; Q2 ejections: u’<0, w’>0; Q3 inward interactions: u’<0, w’<0; Q4 sweeps: u’>0, w’<0) is explored to identify patterns of Reynolds stress signal distributions over the dune. Over flat surfaces, Q2 ejections and Q4 sweeps often dominate RS signals, whereas Q1 outward and Q3 inward interactions are less frequent and contribute negatively to RS generation. Over dunes, however, topographically forced streamline curvature effects alter quadrant activity distributions and, hence, near-surface RS generation by enhancing (at the toe) or inhibiting (at the crest) turbulent motions. This results in Q2 ejection and Q4 sweep activity dominating stress generation on the beach, dune toe, and lower stoss slope, whereas, toward the crest, there is a shift toward Q1 outward and Q3 inward interactions. A flow 'exuberance effect' was identified that explains the contribution of positive to negative contributing activities that varies over the dune and helps explain the spatial pattern in RS. RS generation and sand transport depend on location over the dune (via topographic forcing effects on streamline curvature and flow stagnation/acceleration) and on incident flow direction via topographic steering effects that alter the apparent ‘steepness’ of the dune to flow streamlines. Transport on the lower portion of the dune was driven predominantly by ejection and sweep activity, while toward the crest it became dominated by outward and inward interactions, likely due to increased frequency of streamwise gusts (+u’) and vertical lift (+w’) in topographically compressed flow. / Graduate

Steam assisted gravity drainage (SAGD) has been demonstrated as a proven technology to unlock heavy oil and bitumen in Canadian reservoirs. Given the large energy requirements and volumes of emitted greenhouse gases from SAGD processes, there is a strong motivation to develop enhanced oil recovery processes with lower energy and emission intensities. In this study, the addition of solvents to steam has been examined to reduce the energy intensity of the SAGD process. Higher oil recovery, accelerated oil production rate, reduced steam-to-oil ratio, and more favorable economics are expected from the addition of suitable hydrocarbon additives to steam. A systematic approach was used to develop an effective hybrid steam/solvent injection to improve the SAGD process. Initially, an extensive parametric simulation study was carried out to find the suitable hydrocarbon additives and injection strategies. Simulation studies aim to narrow down hybrid steam/solvent processes, design suitable solvent type and concentration, and explain the mechanism of solvent addition to steam. In the experimental phase, the most promising solvents (n-hexane and n-heptane) were used with different injection strategies. Steam and hydrocarbon additives were injected in continuous or alternating schemes. The results of the integrated experimental and simulation study were used to better understand the mechanism of hybrid steam/solvent processes. Experimental and simulation results show that solvent co-injection with steam leads to a process with higher oil production, better oil recovery, and less energy intensity with more favorable economy. Solvent choice for hybrid steam/solvent injection is not solely dependent on the mobility improvement capability of the solvents but also reservoir properties and operational conditions such as operating pressure and injection strategy. Pure heated solvent injection requires significant quantities. A vaporized solvent chamber is not sustainable due to low latent heat of the solvents. Alternating steam and solvent injection provides heat for the solvent cycles and increases oil recovery. Co-injection of small volumes (5-15% by volume) of suitable solvents at the early times of the SAGD operation considerably improves the economics of the SAGD process.

Molecular dynamics simulation and density functional theory were applied to calculate heats of immersion (Himm) of n-heptane, toluene, pyridine and water on two model sand surfaces and two model clay surfaces. Our results indicated that water showed the highest Himm for the model clay surfaces when multi-molecular water layers were used but the lowest when a single molecular layer was used. Simulations of a single molecular water layer sandwiched between a single molecular layer of the aforementioned organic compounds and the octahedral surface of clay indicated that the water layer was not stable. In particular, water molecules tended to desorb from the surface and clustered together to form water/water hydrogen bonds. Given the nature of bitumen molecules, the current results support the hypothesis that a pre-existing water layer on the sand and clay surfaces in raw oil sands is plausible so long as it is thick enough. / Chemical Engineering