The Late Neogene sedimentary sequence of the Murray Basin provides an excellent opportunity to examine paleoenvironmental change across southeastern Australia. A detailed stratigraphic analysis of sediments deposited within the basin in the last 10 Ma was undertaken to assess the influence of tectonic and eustatic processes on deposition. / Stratigraphic observations and radiogenic isotope analysis reveals the onset of deposition by 7.2 Ma with a transgressive episode that deposited the marine marls of the Bookpurnong Beds. Deposition was restricted to the central and eastern parts of the basin due to the Hamley Fault. In the west, subsurface elevation contours indicate the presence of incised paleodrainage channels above Miocene limestones, which facilitated the formation of a large estuary system at 5.3 Ma. The sediments of the Norwest Bend Formation were deposited within this western region, while further east, the Loxton-Parilla Sands strandplain deposited over 214 coastal ridges. The basal parts of this unit occur as lateral equivalents to the sediments of the Lower Norwest Bend Formation (in the west). Topographic and magnetic data reveal that tectonism was active during this period and resulted in the erosion and truncation of strandlines. / Tectonic evidence and an estimated minimum 28,037 year cyclicity between strandline sets, suggests that the Loxton-Parilla Sands strandlines do not represent an unbroken record of glacioeustatic change. The subaerial exposure of these sediments at approximately 3.0 Ma caused the formation of a calcareous karst above the Norwest Bend Formation and a ferruginous and/or silicious cap (the Karoonda Surface) above the Loxton-Parilla Sands. The stratigraphic position of these surfaces are indicative of a regional widespread unconformity. / The Douglas-Blackburn paleodrainage system in western Victoria was dammed during the Mid-Late Pliocene by uplift associated with the Padthaway High, which caused the formation of a 400,000 km2 lacustrine system, known as Lake Bungunnia. Topographic analysis indicates that Lake Bungunnia comprised at least four distinct sub-basins with water depths of up to 30 metres, with lake shorelines indicating that active tectonism occurred during this period. The resulting lack of sediment input to the coast caused the formation of the Kanawinka Escarpment, a large erosional scarp along the southern margin of the Padthaway High. / The geomorphology of the modern Murray Basin can be directly attributed to the demise of the Lake Bungunnia system. Movement along the Morgan Fault in the west at approximately 700 Ka, resulted in the draining and progressive drying of Lake Bungunnia as a breach was created along the Padthaway High. The Murray River gorge as observed today was incised following this episode. The modern Murray River (and playa lakes such as Lake Tyrell) occupy the lowest elevations along the former sub-basins of Lake Bungunnia. / The Late Neogene sedimentary sequence across the Murray Basin illustrates a complex interaction of eustatic and tectonic processes on deposition. Sedimentation within strandline, estuarine and lacustrine systems, particularly in the western Murray Basin, display evidence of significant tectonic control. This highlights the important role that neotectonic processes have played in shaping southeastern Australia.

Thesis (D. Min.)--Northern Baptist Theological Seminary, Lombard, Ill., 1999. / Abstract. Includes bibliographical references (leaves 125-128).

Thesis (M.Sc.)--University of Alberta, 2010. / Title from PDF file main screen (viewed on July 9, 2010). A thesis submitted to the Faculty of Graduate Studies and Research in partial fulfillment of the requirements for the degree of Master of Science in Land Reclamation and Remediation, Department of Renewable Resources, University of Alberta. Includes bibliographical references.

Thesis (MSc)--University of Stellenbosch, 2006. / Bibliography. Also available via the Internet.

Thesis (MSc)--University of Stellenbosch, 2006. / Bibliography. Also available via the Internet.

Boreal peatlands play important roles in global C and nutrient cycling. Oligotrophic bogs are naturally nitrogen (N) limited, receiving nutrients only via atmospheric deposition. Increased nutrient deposition, particularly N will almost certainly change the microbiology, biogeochemistry, and C and nutrient balances in bogs. Both primary production and decomposition can be affected, but the net effects of N fertilization are complex and unclear. A three-year N fertilization experiment with 15N double labeled 15NH415NO3 as a tracer was designed to study the effects of increasing N deposition on various N pools (including microbial communities, moss, roots, litter, and aboveground vascular plants) and how these N pools process and retain applied N in four ombrogenous bogs in northern Alberta, Canada. Linear growth of Sphagnum mosses was highly variable. However, both capitulum and stem weight showed increase in weight with N addition, resulting in significant increase of capitulum and stem bulk density with N deposition. Total annual primary production, with both capitulum and stem growth accounted for, doubled from low N deposition plots to high N deposition plots. Microbial biomass N measured by chloroform fumigation-extraction only showed a decrease with N deposition in the first year of the experiment. Fungal biomass declined with N deposition as nutrients are readily available under high N loads, perhaps eliminating the need for help from symbiotic fungi for nutrient uptake. The growth of Sphagnum mosses and microbial communities may have been influenced by drier and warmer growing period during 2005 to 2007. These abnormal climatic events could have masked the effects of N deposition on surface Sphagnum moss and microbial communities. This 15N tracer experiment revealed high retention rates of 15N by moss layers as expected. However, retention efficiency of moss layers declined over time and with increasing N deposition, indicating a leakier system as N deposition exceeds the critical load of Sphagnum moss. Aboveground vascular plants overall benefited from N deposition, but different species responded differently based on the root morphology, rooting depths, and the mycorrhizae associations.

A presente pesquisa realizou um estudo que investiga a viabilidade técnica para a reciclagem do resíduo sólido gerado pelo descarte das areias de fundição aglomeradas com argila, para aplicação no setor da construção civil. Para isso, o trabalho estabelece uma metodologia, a qual avalia a estabilização do resíduo em matrizes solidificadas de cimento Portland, melhoradas através de adições de argila bentonita sódica e/ou sílica ativa. A estabilização do resíduo foi verificada através de ensaio de solubilização, o qual submete as matrizes solidificadas a contatos dinâmico e estático com água destilada. Os desempenhos mecânico e físico das matrizes foram avaliados em ensaios de resistência à compressão, absorção de água e permeabilidade ao ar. Os resultados obtidos demonstram que, tanto a bentonita sódica, quanto a sílica ativa contribuem para o aumento da eficiência de fixação dos metais \'AL\', \'FE\' e \'CR\' por parte das matrizes de cimento Portland. As composições que obtiveram os melhores desempenhos mecânico, físico e químico foram utilizadas na confecção de tijolos maciços, visando aplicação na execução de alvenarias. Para a moldagem dos tijolos foi empregada uma prensa hidráulica, o que possibilitou manter a regularidade dimensional das faces. Ao mesmo tempo, o formato dos tijolos foi concebido com design diferenciado, proporcionando modulação e encaixes que podem reduzir significativamente o consumo da argamassa de assentamento. Os tijolos foram submetidos aos ensaios de solubilização, resistência à compressão e absorção de água, apresentando resultados satisfatórios e comprovando a viabilidade técnica para aplicação na execução de alvenarias. / In this research, a study that investigates the technical feasibility for the recycling of solid waste generated by the disposal of the foundry sands bonded with clay, for implementation in the construction industry, was conducted. For this reason, the work establishes a method, which assesses the stabilization of waste in solidified matrices of Portland cement, improved by the additions of sodium bentonite clay and/or silica fume. The stabilization of the waste was verified by solubilization test, which puts the solidified matrices in static and dynamic contacts with distiled water. The mechanical and physical performances of the matrices were evaluated in tests of resistance to compression, absorption of water and air permeability. The results show that both the sodium bentonite, and the active silica contribute to increase the fixation efficiency of the metals \'AL\', \'FE\' and \'CR\' by the matrices of Portland cement. The compositions that have the best mechanical, physical and chemical performance were used in the manufacture of massive bricks, seeking their use in the implementation of masonry. For the molding of bricks a hydraulic press was used, which allowed to keep the dimensional regularity of the faces. At the same time, the format of the bricks was designed with different shapes, providing modulation and fitting that can significantly reduce the consumption of settlement mortar. The bricks were subjected to tests of solubilization, resistance to compression and absorption of water, showing satisfactory results that confirm the technical feasibility for being used in the implementation of masonry.

The identification of petroleum acids, also known as ‘naphthenic’ acids (NA), has been an analytical challenge for over 140 years. However, most recent interest in NA has arisen due to concerns over their presence and apparent associated toxic effect in oil platform produced waters and oil sands process waters (OSPW), respectively. Understanding the toxicity, transformations during biodegradation and remediation treatments and predicting the fate of NA in the environment will be aided by the identification of individual NA. However the elucidation of individual acid structures by standard chromatographic techniques, such as GC-MS, has so far been limited by the extreme complexity of the NA mixtures. Recent analysis of NA as the methyl ester derivatives, by multidimensional gas chromatography-mass spectrometry (GC×GC-MS), has resulted in the identification of several tri- to pentacyclic, aromatic and sulphur-containing acids as well as tricyclic diacids. Therefore the current investigation focused on the identification of the abundant bicyclic acids in petroleum and OSPW acid extracts, utilising the unparalleled chromatographic separation and mass spectrometric detection offered by GC×GC-MS. Analysis of fractionated NA as methyl esters, resulted in the first identification of several bicyclic acids in OSPW including several novel bridged bicyclic acids, several fused bicyclic acids, as well as some terpenoid-derived drimane and labdane acids. However, identifications were limited somewhat by a lack of reference mass spectra and lack of availability of reference compounds for co-chromatography. A complementary method, based on an historical approach, involving reduction of NA esters to hydrocarbons, was modified and substantially improved. Analysis of the hydrocarbons resulting from the reduced acids, by GC×GC-MS, and comparison of the hydrocarbon mass spectra with the more abundant reference spectra available for petroleum hydrocarbons, resulted in the identification of over 40 individual bicyclic acids including fused, bridged and terpenoid-derived acids. The study provides the most comprehensive analysis of one of the major classes of NA (the bicyclic acids) to date. The methods developed were applied to the structural elucidation of NA in commercial NA and OSPW NA and resulted in the identification of numerous alicyclic, aromatic and sulphur-containing acids, supporting and extending previous identifications. There is clear potential for this method to be used for the identification of other unknown acids and functionalised biomarkers in complex matrices. The new knowledge of the acid structures in petroleum and OSPW NA can now be used to inform future research into the environmental monitoring and toxicity of NA.

In the spring of 2016, a wildfire consumed the boreal forest that encircles the municipality of Fort McMurray, Alberta. Notwithstanding the severity of the blaze, known as “The Beast,” attention turned to the community because of its link to Canada’s largest industrial project – the Athabasca tar/oil sands in northern Alberta. A moment of controversy erupted in May 2016 when commentary pinned the cause of the wildfire on climate change, a charge that was quickly judged insensitive. With this context in mind, Fort McMurray holds scholarly value in the investigation of discourse related to today’s dominant form of energy – fossil fuels. Using a dataset of opinion discourse (N=40) sourced from four Canadian newspapers (The Globe and Mail, the National Post, the Calgary Herald, and the Edmonton Journal), this thesis presents a critical discourse analysis of how commentators and editorial boards articulated the relationship between the 2016 Fort McMurray wildfire and concerns about the tar/oil sands contribution to climate change. The opinion pages are free from the journalistic pressure of objectivity and thus offer a place for argumentative narratives to reside. As such, my analysis focuses on the use of storylines in the dataset to give meaning to the wildfire and the tar/oil sands industry. The analysis reveals that the storylines cast environmentalist groups as ideologically motivated radicals while the oil industry was positioned as Alberta’s economic champion, thereby fusing the petro-state with the common good.

During oil-sands mining all vegetation cover, soil, overburden and oil-sand is removed, leaving pits several kilometres wide and hundreds of metres deep. These pits are reclaimed by a variety of treatments using mineral soil or a mixed peat and mineral soil as the capping layer and planted with trees with natural colonisation from adjacent sites. A number of reclamation treatments covering different age classes were compared with a range of natural forest ecotypes to identify the age at which the treatments become similar to a natural site with respect to vegetation composition and key soil attributes relevant to nutrient cycling. Ecosystem function was estimated from plant community composition, litter decomposition, development of an organic layer and bio-available nutrients. Key response variables including moisture, pH, C:N ratios, bio-available nutrients and ground-cover were analysed by non-metric multidimensional scaling and cluster analysis to discover which reclamation treatments were moving towards or merging with natural forest ecotypes and at what age this occurs. On reclaimed sites, bio-available nutrients including nitrate generally were above the natural range of variability but ammonium, phosphorus, potassium, sodium and manganese were generally very low and limiting to ecosystem development. Plant diversity was similar to natural sites from 5 years to 30 years after reclamation, but declined as reclaimed sites approached canopy closure. Grass and forb leaf litters decomposed faster than aspen or pine in the first year, but decomposition on one reclamation treatment fell below the natural range of variability. Development of an organic layer appeared to be facilitated by the presence of shrubs, while forbs correlated negatively with first-year decomposition of aspen litter. The better restoration amendments for tailings sands involved repeated fertilisation of peat: mineral mixtures in the early years of plant establishment, these became similar to a target ecotype at about 25 years. Good results were also shown by subsoil laid over non-saline overburden and fertilised once, these became similar to a target ecotype at about 15 years. Other treatments receiving a single application of fertiliser remain entrenched in the early reclamation phase for up to 25 years. / Forestry, Faculty of / Graduate