In order to determine the degradation of Naphthenic Acids (NAs) in oil sands process-affected water (OSPW), a series of semi-batch ozonation experiments have been conducted resulting in a maximum reduction of NAs greater than 99%. Compared to the high NAs removal, the reduction of both COD and DOC was much lower under the same conditions. Following ozone treatments of approx. 80 mg/L, the cBOD5 and cBOD5/COD tripled as compared to original OSPW measurements, suggesting ozone-treated OSPW has a higher biodegradability. The ozone treatments also detoxified the OSPW; with an ozone treatment of approx. 100 mg/L, the treated OSPW showed no toxicity using the Mircotox® bioassay. Additionally, the coke-treated OSPW, treated using a coke/water slurry process, was found to be non-toxic with an ozone treatment of approx. 20 mg/L. The results obtained during this study shows the great potential ozonation may offer as a possible water treatment application for oil sands water management. / Environmental Engineering

The controlled, _ne-grained microstructure of thermomechanically processed Nb microalloyed linepipe steels is destroyed in the vicinity of welds used in fabricating pipelines. There are conflicting views on the influence of niobium in the `heat-affected zone', particularly in the region closest to the weld fusion line which is most dramatically impacted by the thermal cycling that occurs during welding. Consequently, there is a need to fully characterise the influence of niobium on the evolution of structures and properties in this zone. The aim of the work presented in this thesis was to quantify and characterise precipitates of niobium and dissolved niobium across sub-zones of the weld heat-affected zone, in order to develop a better understanding of the effects of niobium across the region. In order to achieve this, heat treatments were undertaken for the first time to simulate each sub-zone of the heat affected zone such that unique states of dissolved niobium and precipitated niobium was developed. A novel technique as designed and applied for the first time to measure and quantify the precipitate sizes and size distributions in bulk samples of Nb micro-alloyed steels. In addition, measurements of the dissolved niobium across the heat-affected zone were completed in order to ensure that the discrete effects of all states of niobium were subjected to analysis. Weld simulations of the coarse-grained heat-affected zone, the region closest to the weld fusion line, were conducted and assessed against the measured states of niobium. This was followed by the manufacture of commercial welds in order to assess the variation of structures and properties across the heat-affected zone for different plate conditions generated by heat treatment prior to welding. This work established that that a wide range of niobium carbide precipitate sizes were crucial in assuring the excellent mechanical properties in the line-pipe steel, coarser precipitates were found to control the austenite grain size that evolved in the coarse-grain heat affected zone, while fine precipitates dissolved in the thermal cycles close to the weld fusion line, and produced finer microstructures.

The combined effect of temperature, moisture and phosphorus availability on soil organic matter mineralization in permafrost affected soils of northern circumpolar region was investigated. This study was a part of research activities of the European project CryoCARB and it was primarily focused on the cryoturbated organic horizons of permafrost affected soils. During this study, the temperature sensitivity of the organic matter mineralization and its relation to the soil moisture and phosphorus availability was investigated using series of incubation experiments and field measurements.

My study forms part of a bigger project, Resilient Youth in Stressed Environments (RYSE). The purpose of this study of limited scope was to explore the community supports that enable the resilience of adolescents living in the petrochemical-affected community of eMbalenhle in Secunda, South Africa. A number of resilience studies have been conducted both locally and abroad, but none of these has focused on the resilience of youth in petrochemical-affected communities. Since resilience is a complex process that results from individuals’ interaction with their social environments, my study was grounded in the Social Ecology of Resilience Theory (SERT). As an educational psychologist, I employed a phenomenological design with 30 participants (17 males and 13 females) aged 15 to 24 who were selected through purposive sampling from eMbalenhle community. Among these participants, 10 attended school, 2 were at the tertiary educational level and 4 were employed part-time. For this qualitative study I undertook an interpretivist approach to make sense of participants’ interpretations of their experience of living in a petrochemical-affected community. The data was generated by the RYSE team. A variety of arts-based /visual participatory methods (draw-talk-and-write, body theatre, and clay modelling) were used for generating data. I analysed the secondary data by means of inductive thematic content analysis where recurring themes were identified from the data. The main themes that emerged as community supports for adolescent resilience included support from Sasol (jobs, bursaries, learnerships, housing loans etc.), having positive relations with, and drawing support from, other community members and having access to health services and education. These themes indicate that although the petrochemical industry may affect the adolescents negatively it also constitutes their biggest support. The themes also indicate the importance of the social contexts in enabling adolescent wellbeing (as the theory behind SERT suggests should be the case). Therefore, when working with vulnerable adolescents from a petrochemical-affected community, any educational psychologist needs to partner with other role players from the community. / Dissertation (MEd)--University of Pretoria, 2019. / Educational Psychology / MEd / Unrestricted

Celery production has become an important factor in the economy of certain areas in Utah. In 1949 over 400 acres were harvested with an average yield of 800 crates per acre, the average return per crate being $1.80. this amounts to over half a million dollars. The crop serves as a valuable cash crop, creates a demand for hand labor, and serves as an important commercial fertilizer. Little experimental work has been done on the fertilizer requirements of celery in Utah: At the present time estimates of fertilizer need are being based upon grower practices and work done in other areas. Information is needed on the amount of ouch fertilizer element needed to give optimum yields under Utah conditions. The quality of Utah celery in the past has been one of its chief selling points in competition with celery from other areas. If a good market for Utah celery is to be maintained, the quality must be maintained or improved. In the last few years some Utah celery has become pithy and tough which is an expression of poor quality. There is widespread feeling among growers that quality of celery can be improved by fertilizer practice. As yet there is very little experimental evidence on this relationship. This study was arranged to obtain information as to the relationships that exist between yield, quality, the nutrient element content, and applied fertilizer.

Indiana University-Purdue University Indianapolis (IUPUI) / Refugees undergo different kinds of stressors between fleeing their home country and resettling in a new one. Most studies have examined negative aspects of the refugee experience such as mental disorders or resettlement challenges. Building on strengths-based approach, the purpose of this study is to examine resilience-related outcomes. This researcher believes that refugees demonstrate adaptive and positive outcomes in the face of adversities. For this purpose, resilience-related outcomes are conceptualized as local language improvement and social connections in the host country. Using the stress coping model, trauma theory, and resilience theory, this research examines these adaptive outcomes in association with experienced war-trauma and post-migration stressors among Arab-speaking war-affected refugees in the U.S. This researcher recruited 130 participants through mosques and resettlement agencies in Indianapolis. Participants completed a paper-based survey. The researcher conducted several hierarchical regression analyses and found not strong social connections and local language proficiency among the participants. Participants applied problem-focused coping strategies more than other types of strategies. There was a considerable probability of PTSD. Health status and stay length significantly predicted social connections and English language proficiency. In addition, education was found as a significant factor in improving language proficiency. The analysis indicated that problem-focused and emotion-focused coping strategies buffer the negative effects of war trauma and feeling of loss on social connections. The study revealed negative impact of dysfunctional coping strategies on potential PTSD among the participants. Implications for social work practice, education, and policy, as well as, recommendations for future studies are discussed.

The Mackenzie Delta region of the Northwest Territories, Canada, has experienced rapid climate warming in the past century resulting in rapidly thawing permafrost in this region. This thesis examines spatial and temporal changes to sediment organic carbon and mercury flux in lakes from thermokarst regions by comparing sediment cores from lakes with and without retrogressive thaw slumps on their shorelines. We show that sediments from lakes with permafrost thaw slump development on their shorelines (slump lakes) had higher sedimentation rates as well as lower total Hg, methyl mercury (MeHg), and labile OC fractions when compared to lakes where thaw slumps were absent. Total Hg and MeHg concentrations in sediments were correlated with total organic carbon (TOC), S2 (labile algal-derived OC), and inferred chlorophyll a content, indicating an association between autochthonous organic carbon and Hg in these sediments. Correlations between mercury and S2 in these study lakes generally support the hypothesis that algal-derived materials correlate with Hg concentration in sediments. We observed higher S2 concentrations in reference lakes than in slump lakes, likely due to uninterrupted algal production, lower dilution by flux of inorganic matter, and possibly better anoxic preservation in reference lakes compared to slump lakes. It is evident that thaw slump development in this thermokarst region increases inorganic sedimentation in lakes, while decreasing concentrations of organic carbon and associated Hg and MeHg in sediments.

An essential element of the reclamation strategy proposed by the oil sands mining industry in northern Alberta, Canada, includes the creation of wetlands for the bioremediation of mining waste materials. The mining process used to extract oil from these deposits results in the production of large volumes of process-affected water (OSPW) and sediments (OSPS), which must be incorporated into wetlands as a component of the reclaimed landscapes. Wood frogs (<i>Rana sylvatica</i>) are an abundant native species that might be expected to inhabit these reclaimed wetlands. The objective of this study was to determine potential detrimental effects of OSPW and OSPS on the growth and development of wood frogs. Several morphological (weight, length, condition factor) and biochemical (whole body tadpole thyroid hormone and triglyceride concentrations and metamorph hepatic glycogen concentration) endpoints were assessed in conjunction with hatchability and survivability of wood frog eggs and tadpoles exposed to process-affected materials (OSPM) under field and laboratory conditions.<p> As part of this study, assay techniques were optimized to enable simultaneous measurement of whole body 3,5,3-triiodothyronine (T3), thyroxine (T4) and triglyceride (TG) concentrations in wood frog tadpoles. These assays were used to monitor changes in T3, T4 and TG in wood frog tadpoles during development from hatching to metamorphosis (Gosner stages 19-46), to establish baseline levels for subsequent application of the assays to evaluate contaminant effects. The results indicated peak T3 and T4 concentrations occurred during metamorphic climax (Gosner stages 40-46) and prometamorphosis (Gosner stages 31-40), respectively. Maximal TG concentrations were also observed during prometamorphosis. These assays were further employed to assess body condition and development in wood frogs during a field study in 2005, and the following laboratory studies in 2006 and 2007.<p> In summer 2005, 29 reclaimed and five unimpacted wetlands were monitored for use by native amphibians, and tadpoles and newly-metamorphosed wood frogs were collected from a subset of sites as a preliminary assessment of contaminant effects. Endpoints such as metamorph hepatic glycogen and whole body tadpole T3, T4 and triglyceride concentrations were compared among six impacted and three reference wetlands. The surveys indicated 60% of OSPW-impacted wetlands were used by breeding adult amphibians, while wood frog tadpoles and newly-metamorphosed frogs were observed in 37 and 30% of OSPW wetlands, respectively. In general, lower whole body tadpole T3 and triglyceride concentrations were observed in wood frogs from wetlands containing OSPM. In contrast, hepatic glycogen concentrations in newly-metamorphosed frogs and whole body tadpole T4 and T3/T4 concentrations were comparable among the reference and impacted wetlands. In addition, the differences observed in total body weight and length of tadpoles and newly-metamorphosed wood frogs among OSPM and reference sites were likely due to minor differences in developmental stages of the animals collected from the various wetlands, rather than any contaminant effect.<p> In 2006 and 2007, wood frog eggs and tadpoles were exposed to several sources of OSPW and OSPS collected from reclaimed Suncor and Syncrude wetlands under controlled laboratory conditions. Hatchability was reduced in eggs exposed to water from only one of the OSPW sites, compared with the other process-affected ponds and the control water (P<0.05). In contrast, survivability of tadpoles was significantly reduced (P<0.05) in all the impacted sites in both years, with nearly all OSPW sites having <10% survival. The exposure study evaluated the toxicity of five types of OSPS. Results indicated no impact of OSPS exposure on survivability of tadpoles, but showed reduced whole body weight (in three OSPS treatments), length (in two OSPS treatments) and body condition (in one OSPS) of tadpoles exposed to process-affected substrates tested (P<0.05). Whole body T3 and T4 concentrations in tadpoles from OSPS treatments were not different from the control treatment, but tadpole TG concentration was reduced in groups exposed to two impacted substrates (P<0.05). Water quality measurements, including determination of dissolved metals were conducted in an initial attempt to relate any potential toxic effect on wood frog growth and development to specific contaminants.<p> Results of the laboratory studies strongly suggest that exposure to OSPW and OSPS may adversely affect wood frog growth and survival. However, these findings were not entirely consistent with field observations and results of concurrent mesocosm studies. Further research is therefore needed to fully evaluate the suitability of reclaimed oil sands wetlands to support indigenous amphibian population. Future work should focus on the cumulative effects of water and substrates, as well as the effect of OSPM ageing on acute and chronic toxicity.

The Mackenzie Delta region of the Northwest Territories, Canada, has experienced rapid climate warming in the past century resulting in rapidly thawing permafrost in this region. This thesis examines spatial and temporal changes to sediment organic carbon and mercury flux in lakes from thermokarst regions by comparing sediment cores from lakes with and without retrogressive thaw slumps on their shorelines. We show that sediments from lakes with permafrost thaw slump development on their shorelines (slump lakes) had higher sedimentation rates as well as lower total Hg, methyl mercury (MeHg), and labile OC fractions when compared to lakes where thaw slumps were absent. Total Hg and MeHg concentrations in sediments were correlated with total organic carbon (TOC), S2 (labile algal-derived OC), and inferred chlorophyll a content, indicating an association between autochthonous organic carbon and Hg in these sediments. Correlations between mercury and S2 in these study lakes generally support the hypothesis that algal-derived materials correlate with Hg concentration in sediments. We observed higher S2 concentrations in reference lakes than in slump lakes, likely due to uninterrupted algal production, lower dilution by flux of inorganic matter, and possibly better anoxic preservation in reference lakes compared to slump lakes. It is evident that thaw slump development in this thermokarst region increases inorganic sedimentation in lakes, while decreasing concentrations of organic carbon and associated Hg and MeHg in sediments.

An essential element of the reclamation strategy proposed by the oil sands mining industry in northern Alberta, Canada, includes the creation of wetlands for the bioremediation of mining waste materials. The mining process used to extract oil from these deposits results in the production of large volumes of process-affected water (OSPW) and sediments (OSPS), which must be incorporated into wetlands as a component of the reclaimed landscapes. Wood frogs (<i>Rana sylvatica</i>) are an abundant native species that might be expected to inhabit these reclaimed wetlands. The objective of this study was to determine potential detrimental effects of OSPW and OSPS on the growth and development of wood frogs. Several morphological (weight, length, condition factor) and biochemical (whole body tadpole thyroid hormone and triglyceride concentrations and metamorph hepatic glycogen concentration) endpoints were assessed in conjunction with hatchability and survivability of wood frog eggs and tadpoles exposed to process-affected materials (OSPM) under field and laboratory conditions.<p> As part of this study, assay techniques were optimized to enable simultaneous measurement of whole body 3,5,3-triiodothyronine (T3), thyroxine (T4) and triglyceride (TG) concentrations in wood frog tadpoles. These assays were used to monitor changes in T3, T4 and TG in wood frog tadpoles during development from hatching to metamorphosis (Gosner stages 19-46), to establish baseline levels for subsequent application of the assays to evaluate contaminant effects. The results indicated peak T3 and T4 concentrations occurred during metamorphic climax (Gosner stages 40-46) and prometamorphosis (Gosner stages 31-40), respectively. Maximal TG concentrations were also observed during prometamorphosis. These assays were further employed to assess body condition and development in wood frogs during a field study in 2005, and the following laboratory studies in 2006 and 2007.<p> In summer 2005, 29 reclaimed and five unimpacted wetlands were monitored for use by native amphibians, and tadpoles and newly-metamorphosed wood frogs were collected from a subset of sites as a preliminary assessment of contaminant effects. Endpoints such as metamorph hepatic glycogen and whole body tadpole T3, T4 and triglyceride concentrations were compared among six impacted and three reference wetlands. The surveys indicated 60% of OSPW-impacted wetlands were used by breeding adult amphibians, while wood frog tadpoles and newly-metamorphosed frogs were observed in 37 and 30% of OSPW wetlands, respectively. In general, lower whole body tadpole T3 and triglyceride concentrations were observed in wood frogs from wetlands containing OSPM. In contrast, hepatic glycogen concentrations in newly-metamorphosed frogs and whole body tadpole T4 and T3/T4 concentrations were comparable among the reference and impacted wetlands. In addition, the differences observed in total body weight and length of tadpoles and newly-metamorphosed wood frogs among OSPM and reference sites were likely due to minor differences in developmental stages of the animals collected from the various wetlands, rather than any contaminant effect.<p> In 2006 and 2007, wood frog eggs and tadpoles were exposed to several sources of OSPW and OSPS collected from reclaimed Suncor and Syncrude wetlands under controlled laboratory conditions. Hatchability was reduced in eggs exposed to water from only one of the OSPW sites, compared with the other process-affected ponds and the control water (P<0.05). In contrast, survivability of tadpoles was significantly reduced (P<0.05) in all the impacted sites in both years, with nearly all OSPW sites having <10% survival. The exposure study evaluated the toxicity of five types of OSPS. Results indicated no impact of OSPS exposure on survivability of tadpoles, but showed reduced whole body weight (in three OSPS treatments), length (in two OSPS treatments) and body condition (in one OSPS) of tadpoles exposed to process-affected substrates tested (P<0.05). Whole body T3 and T4 concentrations in tadpoles from OSPS treatments were not different from the control treatment, but tadpole TG concentration was reduced in groups exposed to two impacted substrates (P<0.05). Water quality measurements, including determination of dissolved metals were conducted in an initial attempt to relate any potential toxic effect on wood frog growth and development to specific contaminants.<p> Results of the laboratory studies strongly suggest that exposure to OSPW and OSPS may adversely affect wood frog growth and survival. However, these findings were not entirely consistent with field observations and results of concurrent mesocosm studies. Further research is therefore needed to fully evaluate the suitability of reclaimed oil sands wetlands to support indigenous amphibian population. Future work should focus on the cumulative effects of water and substrates, as well as the effect of OSPM ageing on acute and chronic toxicity.