5 resultados para Plurality of worlds.
em QSpace: Queen's University - Canada
Resumo:
Lithium is used in the cathode and electrolyte of rechargeable batteries in many portable electronics and electric vehicles, and is thus seen as a critical component of modern technology (Gruber et al., 2011). Electric vehicles are promoted as a way to reduce carbon emissions associated with the transportation sector, which accounts for 14.3% of anthropogenic greenhouse gas emissions (OECD International Transport Forum, 2010). However, the sustainability of lithium procurement will influence the overall environmental impact of this proposed “green” solution. It is estimated that 66% of the world’s lithium resource is contained in natural brines, 24% in pegmatites, and 8% in sedimentary rocks such as hectorite clays (Gruber et al., 2011). It has been shown that “[r]ecycling of lithium from Li-ion batteries may be a critical factor in balancing the supply of lithium with future demand” (Gruber et al., 2011). In an attempt to quantify energy and materials consumption associated with production of a unit of useful lithium compounds, industry reports and peer-reviewed scientific literature concerning lithium mining and lithium recycling were reviewed and compared. Other aspects of sustainability, such as waste or by-products produced in the production of a unit of useful lithium, were also explored. Thus, this paper will serve to further the evaluation of the comparative environmental consequences associated with lithium production via extraction versus recycling. Efficiencies must be made in both processes to maximize productivity while minimizing ecological harm.
Resumo:
The Australian southern continental margin is the world’s largest site of cool-water carbonate deposition, and the Great Australian Bight is its largest sector. The Eyre Peninsula is fringed by coastal beaches with aeolianites and marks the eastern edge of the Great Australian Bight. Five shoreline transects of varying lengths spanned a 150km longitudinal distance and at each the intertidal, beach, dune and secondary dune environments were sampled, for a total of 18 samples. Sediments are a mixture of modern, relict, and Cenozoic carbonates, and quartz grains. Carbonate aeolianites on the western Eyre Peninsula are mostly composed of modern carbonate grains: predominantly molluscs (23-33%) and benthic foraminifera (10-26%), locally abundant coralline algae (3-28%), echinoids (2-22%), and bryozoans (2-14%). Cenozoic grain abundance ranges from 1-6% whereas relict grain abundance ranges from 0-17%. A southward increase in bryozoan particles correlates with a nutrient element abundance and decrease in temperature due to a large seasonal coastal upwelling system that drives 2-3 major upwelling events per year, bringing cold, nutrient rich, Sub-Antarctic Surface Water (<12°C) onto the shelf. In southern, mostly wind protected locations, the beach and dune sediment compositions are similar, indicating that wind energy has successfully carried all sediment components of the beach into the adjacent dunes. In northern, exposed locations, the composition is not the same everywhere, and trends indicate that relative wind energy has the ability to impact grain composition through preferential wind transport. Aeolianite composition is therefore a function of both upwelling and the degree of coastal exposure.
Resumo:
Recently, resilience has become a catchall solution for some of the world’s most pressing ecological, economic and social problems. This dissertation analyzes the cultural politics of resilience in Kingston, Jamaica by examining them through their purported universal principles of adaptation and flexibility. On the one hand, mainstream development regimes conceptualize resilience as a necessary and positive attribute of economies, societies and cultures if we are to survive any number of disasters or disturbances. Therefore, in Jamaican cultural and development policy resilience is championed as both a means and an end of development. On the other hand, critics of resilience see the new rollout of resilience projects as deepening neoliberalism, capitalism and new forms of governmentality because resilience projects provide the terrain for new forms of securitization and surveillance practices. These scholars argue that resilience often forecloses the possibilities to resist that which threatens us. However, rather than dismissing resilience as solely a sign of domination and governmentality, this dissertation argues that resilience must be understood as much more ambiguous and complex, rather than within binaries such as subversion vs. neoliberal and resistance vs. resilience. Overly simplistic dualities of this nature have been the dominant approach in the scholarship thus far. This dissertation provides a close analysis of resilience in both multilateral and Jamaican government policy documents, while exploring the historical and contemporary production of resilience in the lives of marginalized populations. Through three sites within Kingston, Jamaica—namely dancehall and street dances, WMW-Jamaica and the activist platform SO((U))L HQ—this dissertation demonstrates that “resilience” is best understood as an ambiguous site of power negotiations, social reproduction and survival in Jamaica today. It is often precisely this ambiguous power of ordinary resilience that is capitalized on and exploited to the detriment of vulnerable groups. At once demonstrating creative negotiation and reproduction of colonial capitalist social relations within the realms of NGO, activist work and cultural production, this dissertation demonstrates the complexity of resilience. Ultimately, this dissertation draws attention to the importance of studying spaces of cultural production in order to understand the power and limits of contemporary policy discourses and political economy.
Resumo:
Global niobium production is presently dominated by three operations, Araxá and Catalão (Brazil), and Niobec (Canada). Although Brazil accounts for over 90% of the world’s niobium production, a number of high grade niobium deposits exist worldwide. The advancement of these deposits depends largely on the development of operable beneficiation flowsheets. Pyrochlore, as the primary niobium mineral, is typically upgraded by flotation with amine collectors at acidic pH following a complicated flowsheet with significant losses of niobium. This research compares the typical two stage flotation flowsheet to a direct flotation process (i.e. elimination of gangue pre-flotation) with the objective of circuit simplification. In addition, the use of a chelating reagent (benzohydroxamic acid, BHA) was studied as an alternative collector for fine grained, highly disseminated pyrochlore. For the amine based reagent system, results showed that while comparable at the laboratory scale, when scaled up to the pilot level the direct flotation process suffered from circuit instability because of high quantities of dissolved calcium in the process water due to stream recirculation and fine calcite dissolution, which ultimately depressed pyrochlore. This scale up issue was not observed in pilot plant operation of the two stage flotation process as a portion of the highly reactive carbonate minerals was removed prior to acid addition. A statistical model was developed for batch flotation using BHA on carbonatite ore (0.25% Nb2O5) that could not be effectively upgraded using the conventional amine reagent scheme. Results showed that it was possible to produce a concentrate containing 1.54% Nb2O5 with 93% Nb recovery in ~15% of the original mass. Fundamental studies undertaken included FT-IR and XPS, which showed the adsorption of both the protonized amine and the neutral amine onto the surface of the pyrochlore (possibly at niobium sites as indicated by detected shifts in the Nb3d binding energy). The results suggest that the preferential flotation of pyrochlore over quartz with amines at low pH levels can be attributed to a difference in critical hemimicelle concentration (CHC) values for the two minerals. BHA was found to be absorbed on pyrochlore surfaces by a similar mechanism to alkyl hydroxamic acid. It is hoped that this work will assist in improving operability of existing pyrochlore flotation circuits and help promote the development of niobium deposits globally. Future studies should focus on investigation into specific gangue mineral depressants and inadvertent activation phenomenon related to BHA flotation of gangue minerals.
Resumo:
The commodification of natural resources and the pursuit of continuous growth has resulted in environmental degradation, depletion, and disparity in access to these life-sustaining resources, including water. Utility-based objectification and exploitation of water in some societies has brought us to the brink of crisis through an apathetic disregard for present and future generations. The ongoing depletion and degradation of the world’s water sources, coupled with a reliance on Western knowledge and the continued omission of Indigenous knowledge to manage our relationship with water has unduly burdened many, but particularly so for Indigenous communities. The goal of my thesis research is to call attention to and advance the value and validity of using both Indigenous and Western knowledge systems (also known as Two-Eyed Seeing) in water research and management to better care for water. To achieve this goal, I used a combined systematic and realist review method to identify and synthesize the peer-reviewed, integrative water literature, followed by semi-structured interviews with first authors of the exemplars from the included literature to identify the challenges and insights that researchers have experienced in conducting integrative water research. Findings suggest that these authors recognize that many previous attempts to integrate Indigenous knowledges have been tokenistic rather than meaningful, and that new methods for knowledge implementation are needed. Community-based participatory research methods, and the associated tenets of balancing power, fostering trust, and community ownership over the research process, emerged as a pathway towards the meaningful implementation of Indigenous and Western knowledge systems. Data also indicate that engagement and collaborative governance structures developed from a position of mutual respect are integral to the realization of a given project. The recommendations generated from these findings offer support for future Indigenous-led research and partnerships through the identification and examination of approaches that facilitate the meaningful implementation of Indigenous and Western knowledge systems in water research and management. Asking Western science questions and seeking Indigenous science solutions does not appear to be working; instead, the co-design of research projects and asking questions directed at the problem rather than the solution better lends itself to the strengths of Indigenous science.