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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
211

Nedläggning av folkbibliotek : Är ideellt idealt? / Closure of libraries : is nonprofit ideal?

Andersson, Heléne January 2015 (has links)
This study examines the closure of public libraries, and the nonprofit organizations takeover of them as a phenomenon. The aim is to understand why the nonprofit takeover is common and what the takeover symbolizes and if the discourse in media invokes the views on libraries and the profession.Interviews were made with librarians, politicians and representatives of a nonprofit organization to study different sides of the phenomenon. Other empirical data were found in local and national newspapers and media-channels. I discovered that public libraries are highly valued by both politicians and the community. The study also showed that a library in a community makes people feel valued. It is often the economical problems of the communities that increases the risk of library closures. The politicians request in media, where they sometimes demand nonprofit organizations to take over library activity, can reflect upon the value of the profession and the opinions about the field. The takeover seems to be an effort of keeping the symbol that the library represents in the community and it also seems to be a symbol for the community. The symbol is for example associated with a democratic meeting-place, education and integration. The librarian is associated with good service. This is a two years master’s thesis in library and information science.
212

Détection de l'initiation de la délamination des matériaux composites par suivi de l'émission acoustique

Silversides, Ian January 2012 (has links)
Cette étude, basée sur la surveillance des ondes d'émission acoustique (E.A.), présente le développement d'une approche de prédiction de l'initiation de la délamination de pièces composites soumises à des chargements statiques et en fatigue. La surveillance des ondes d'E.A. fait parti d'un nombre restreint de méthodes pouvant détecter, en continu, l'apparition et la croissance de dommages dans les matériaux composites. L'approche est comparée à des méthodes conventionnelles ainsi qu'à une modélisation numérique pour des composites à fibre de carbone unidirectionnels et tissés, sur une gamme de rapports de mode mixte. Le présent mémoire met en lumière les différentes étapes abordées durant l'étude. L'utilisation des matériaux composites est mise en contexte au premier chapitre. La complexité des matériaux composites ainsi que la nécessité de modèles de prédiction fiables sont soulignées. Le deuxième chapitre contient une revue de la littérature et présente les outils disponibles pour analyser le délaminage et bâtir un modèle prédictif de sa propagation. Les sujets traités sont la délamination dans un contexte de mécanique de la rupture, la modélisation numérique d'une propagation de fissure, l'approche du monitorage par émission acoustique puis l'analyse fractographiques des surfaces de rupture. Les résultats des essais mécaniques et de la modélisation sont présentés sous forme d'article dans le troisième chapitre. Des essais statiques et en fatigue ont permis de calculer le taux de restitution d'énergie de déformation à l'initiation de la délamination selon des méthodes classiques pour ensuite les comparer à une méthode développée, basée sur le suivi des ondes d'émission acoustique. Une série d'essais de propagation de la délamination en fatigue ont permis d'observer des corrélations entre les émissions acoustiques, la longueur de la délamination, la vitesse de croissance des fissures et la sévérité du chargement. Finalement, une méthodologie de reconnaissance des formes non supervisée est présentée afin de discriminer les signaux d'E.A. d'amorçage et de propagation de fissure du bruit associé à la fatigue.
213

The role of vegetation in characterising landscape function on rehabilitating gold tailings / A.S.H. Haagner

Haagner, Adrian Sigmund Harold January 2008 (has links)
Gold mine waste poses a significant challenge for rehabilitation practitioners and can negatively impact on soil, air, surface water and groundwater quality. This, in turn, can affect the environmental quality of humans and other biota in nearby settlements and surrounding ecosystems. All mines are required to have a plan in place to impede or mitigate these environmental impacts and to ensure that all legislation is complied with to apply for closure. Site closure is the eventual goal of all mine residue complexes, as it is the stage at which a company becomes released from all legal and financial liability. The South African legislation is comprehensive and essentially requires that all latent and residual environmental impacts are addressed and that an end land-use designation is put in place that conforms to the principles of sustainable development. The Chemwes Tailings Storage Facility complex near Stilfontein was monitored to provide a strategic assessment of the state of the rehabilitation, and to provide recommendations for the successful remediation of problem sites. A combination of vegetation sampling, landscape function assessments and substrate chemical analyses were conducted to gain a predictive understanding of rehabilitation progress. The monitoring was conducted over two years across a chronosequence of rehabilitating sites from tailings dam slopes and an adjacent spillage site. An undisturbed grassland and a starter-wall served as reference sites. The data were first analysed independently and then by making use of multivariate data ordinations. This allowed for holistic investigations of the relationships between sites, substrate chemistry, vegetation composition and landscape function. The results showed that the tailings dams had a distinctly different suite of vegetation from the reference sites, but had no statistically significant differences in composition across the rehabilitating chronosequence. There were positive correlations between rehabilitation site age and landscape function indices, suggesting that some aspects of ecosystem development were occurring over time. In some sites, deterioration in the substrate quality as a growth medium was observed with increases in acidity and salinity. This was most likely caused by pyrite oxidation in the tailings and the high concentrations of free salts. The increasing acidity and salinity resulted in vegetation senescence and declines in landscape function. However, those sites that possessed higher landscape function appeared to have the ecosystem processes in place that temporarily suppressed negative chemical changes. Whilst this was encouraging,the rehabilitation chronosequence had not yet proven the self-sustainability that it would require for closure purposes. Further monitoring would be required over time. The sustainability of the rehabilitating chronosequence was brought into question by the high acid-forming potential of the tailings growth medium. Concerns were also raised over the ability of the established vegetation cover to persist under conditions of increasing stress and disturbance. Furthermore, the land-use capabilities of the sites are limited by current rehabilitation procedures and various recommendations were made to rectify this. A more streamlined monitoring framework for the tailings complex was also proposed. The contribution of this work lies in its holistic integration of monitoring techniques and the meaningful analysis of ecosystem function, an aspect largely ignored in minesite rehabilitation. / Thesis (M.Sc. (Environmental Sciences and Management))--North-West University, Potchefstroom Campus, 2009.
214

Managing biodiversity in a developing country mining context / Fick H.J.

Fick, Hendrik Jacobus January 2011 (has links)
South Africa is one of the most biologically diverse countries in the world. However, biodiversity is suffering under the huge demand for natural resources and the increasing dependence of rural communities on these same resources. It has also become apparent that an alarming number of species are threatened, endangered or even destroyed. Surveys have revealed that 34% of the country’s 440 terrestrial ecosystems are threatened. The three severest threats to biodiversity are overexploitation, overgrazing and mining. There is however a range of international, regional, national and local laws and best practice guidelines that aim to protect and preserve the natural faunal and floral diversity of the various rural areas and regions. The prescription of sustainable practices enables communities that depend on the services of ecosystem in their area, to utilise without depleting the resources provided by nature. South Africa is a signing party to more than seven conventions and treaties that either protect or govern biodiversity. In addition to this, the South African government has promulgated eighteen pieces of legislation and guidelines to protect and govern the use of biodiversity. The focus of this study was on the impacts platinum mining have on biodiversity and how effectively these impacts are managed. Data for the case study was obtained from Impala Platinum. Impala leases its land from the Royal Bafokeng Nation and inter alia shares it with the people who use the areas in between for grazing and other subsistence activities. The aim of the study was, in the first place to identify how Impala Platinum’s Environmental Management Plans (EMP’s) and Closure Plan (which manages current and post mining activities and their impacts) are aligned with the various international, national and local requirements for biodiversity management, and secondly to evaluate the effectiveness of the current management measures put in place, which regulates activities impacting on biodiversity. To give effect to the above outcome it was necessary to first identify the various international, national and local treaties, legislature and guidelines. Secondly, an environmental risk assessment was conducted where the current management measure were weighed against the various international, national and local requirements in order to deduce the level of effectiveness of the current EMP’s and Closure plan. It was found that the majority of the EMP’s compiled under the Environmental Conservation Act No. 73 of 1989 (ECA) lack substantive management and preventative measures. It was only in the later EMP’s (between the years 2000 - 2004) that the prescribed management measures improved and became more effective. This was because the Environmental Impact Assessment (EIA) process had matured in South Africa and an entire new regime of more descriptive EIA regulations had been promulgated under the National Environmental Act No. 107 of 1998, which repealed the majority of the outdated ECA regulations. It was also found that the environmental standards, management objectives and priorities that were developed in the EMP’s did not contingently and specifically reflect the conditions in relation to the environmental, developmental and biodiversity contexts to which they apply. The Closure plan on the other hand, was a regurgitation of the same unimaginative objectives focusing on remedying past legacies instead of providing a lasting solution to sustain and improve the environmental conditions left by the mine, and most importantly it does not address the social issues that result from mine closure. For example, the overexploitation and overgrazing of the areas in between the various mining operations by the Royal Bafokeng Nation’s people is a crucial aspect that has not been thoroughly addressed in the respective documents. Habitat disturbance, which was not addressed for instance, requires a wide range of actions e.g. educating local communities on pasture management, post–rehabilitation monitoring, amelioration etc. To improve compliance with current legislation and adherence to the guidelines proposed by best practice initiatives, various recommendations are put forward to control both the negative activities brought on by the Royal Bafokeng and Impala Platinum. These include the implementation of: Biodiversity (inclusive) impact assessment, good environmental governance, the precautionary approach, the ecosystems approach, sustainable biodiversity management practices through conservation planning, biodiversity action plans, stewardship and land care tools, conservation plans, biodiversity offsets, effective mine closure planning and the forming of a Biodiversity Action Steering Committee (BASC). Finally, an eight step model is proposed as a tool to evaluate the effectiveness of specifically the platinum mine’s EMP’s and Closure plans to manage activities affecting biodiversity. The model is based on the concepts of direct and indirect drivers of change and the Deming cycle and is an elaboration of the model proposed by UNEP and the International Association of Impact Assessment. The model focuses on both the natural and anthropogenic drivers that may affect biodiversity and will aid the management of a mine to supplement the shortcomings of these documents. As an indirect outcome the model may possibly even improve, the relationship between the specific company and the communities with which it shares its land. / Thesis (M. Environmental Management)--North-West University, Potchefstroom Campus, 2012.
215

An evaluation of the use of natural stable isotopes of water to track water movement through oil sands mine closure landforms

2014 March 1900 (has links)
Surface mining of oil sands results in extensive land disturbance, earth movement and water usage. After mining, the disturbed landscapes must be reconstructed and reclaimed as natural landforms. There are numerous challenges associated with understanding the responses of these landforms over time, including a need to track and characterize water movement through closure landforms to understand the hydrological responses of these landforms over time. This study attempted to use natural stable isotopes of water (δD and δ18O) to identify and characterize source waters from various closure landforms at an oil sands mine site. The study area is Syncrude‟s Mildred Lake mine, an open pit oil sands mine located in northern Alberta. A variety of groundwater, surface water and soil samples from a variety of landforms (overburden dumps, composite and mature fine tailings areas, tailings sand structures and freshwater reservoirs) were collected in an attempt to fully represent the isotopic distribution of waters across the mine site. Laboratory analysis of δD and δ18O was done on all samples. The local meteoric water line first established by Hilderman (2011) was redeveloped with additional precipitation data and calculated to be δD=7.0(δ18O) -18.6‰. A natural evaporation line having a slope of 5.3 was calculated for the mine site with samples collected from three surface water ponds on the mine site. Five primary source waters were identified on the mine site: process affected water/tailings, rainfall, snow, interstitial shale water and Mildred Lake water. It was found that these sources of water generally have unique natural stable water isotope signatures. Process affected water at the site generally had an enriched signature compared to other mine waters. The enrichment was attributed to fractionation from the recycle water circuit and natural evaporation. The characterizations of these source waters were then used in several hydrogeological examples to demonstrate that natural stable water isotopes can be applied to water balance estimates and to identify water movement processes related to closure landforms.
216

The role of vegetation in characterising landscape function on rehabilitating gold tailings / A.S.H. Haagner

Haagner, Adrian Sigmund Harold January 2008 (has links)
Gold mine waste poses a significant challenge for rehabilitation practitioners and can negatively impact on soil, air, surface water and groundwater quality. This, in turn, can affect the environmental quality of humans and other biota in nearby settlements and surrounding ecosystems. All mines are required to have a plan in place to impede or mitigate these environmental impacts and to ensure that all legislation is complied with to apply for closure. Site closure is the eventual goal of all mine residue complexes, as it is the stage at which a company becomes released from all legal and financial liability. The South African legislation is comprehensive and essentially requires that all latent and residual environmental impacts are addressed and that an end land-use designation is put in place that conforms to the principles of sustainable development. The Chemwes Tailings Storage Facility complex near Stilfontein was monitored to provide a strategic assessment of the state of the rehabilitation, and to provide recommendations for the successful remediation of problem sites. A combination of vegetation sampling, landscape function assessments and substrate chemical analyses were conducted to gain a predictive understanding of rehabilitation progress. The monitoring was conducted over two years across a chronosequence of rehabilitating sites from tailings dam slopes and an adjacent spillage site. An undisturbed grassland and a starter-wall served as reference sites. The data were first analysed independently and then by making use of multivariate data ordinations. This allowed for holistic investigations of the relationships between sites, substrate chemistry, vegetation composition and landscape function. The results showed that the tailings dams had a distinctly different suite of vegetation from the reference sites, but had no statistically significant differences in composition across the rehabilitating chronosequence. There were positive correlations between rehabilitation site age and landscape function indices, suggesting that some aspects of ecosystem development were occurring over time. In some sites, deterioration in the substrate quality as a growth medium was observed with increases in acidity and salinity. This was most likely caused by pyrite oxidation in the tailings and the high concentrations of free salts. The increasing acidity and salinity resulted in vegetation senescence and declines in landscape function. However, those sites that possessed higher landscape function appeared to have the ecosystem processes in place that temporarily suppressed negative chemical changes. Whilst this was encouraging,the rehabilitation chronosequence had not yet proven the self-sustainability that it would require for closure purposes. Further monitoring would be required over time. The sustainability of the rehabilitating chronosequence was brought into question by the high acid-forming potential of the tailings growth medium. Concerns were also raised over the ability of the established vegetation cover to persist under conditions of increasing stress and disturbance. Furthermore, the land-use capabilities of the sites are limited by current rehabilitation procedures and various recommendations were made to rectify this. A more streamlined monitoring framework for the tailings complex was also proposed. The contribution of this work lies in its holistic integration of monitoring techniques and the meaningful analysis of ecosystem function, an aspect largely ignored in minesite rehabilitation. / Thesis (M.Sc. (Environmental Sciences and Management))--North-West University, Potchefstroom Campus, 2009.
217

Managing biodiversity in a developing country mining context / Fick H.J.

Fick, Hendrik Jacobus January 2011 (has links)
South Africa is one of the most biologically diverse countries in the world. However, biodiversity is suffering under the huge demand for natural resources and the increasing dependence of rural communities on these same resources. It has also become apparent that an alarming number of species are threatened, endangered or even destroyed. Surveys have revealed that 34% of the country’s 440 terrestrial ecosystems are threatened. The three severest threats to biodiversity are overexploitation, overgrazing and mining. There is however a range of international, regional, national and local laws and best practice guidelines that aim to protect and preserve the natural faunal and floral diversity of the various rural areas and regions. The prescription of sustainable practices enables communities that depend on the services of ecosystem in their area, to utilise without depleting the resources provided by nature. South Africa is a signing party to more than seven conventions and treaties that either protect or govern biodiversity. In addition to this, the South African government has promulgated eighteen pieces of legislation and guidelines to protect and govern the use of biodiversity. The focus of this study was on the impacts platinum mining have on biodiversity and how effectively these impacts are managed. Data for the case study was obtained from Impala Platinum. Impala leases its land from the Royal Bafokeng Nation and inter alia shares it with the people who use the areas in between for grazing and other subsistence activities. The aim of the study was, in the first place to identify how Impala Platinum’s Environmental Management Plans (EMP’s) and Closure Plan (which manages current and post mining activities and their impacts) are aligned with the various international, national and local requirements for biodiversity management, and secondly to evaluate the effectiveness of the current management measures put in place, which regulates activities impacting on biodiversity. To give effect to the above outcome it was necessary to first identify the various international, national and local treaties, legislature and guidelines. Secondly, an environmental risk assessment was conducted where the current management measure were weighed against the various international, national and local requirements in order to deduce the level of effectiveness of the current EMP’s and Closure plan. It was found that the majority of the EMP’s compiled under the Environmental Conservation Act No. 73 of 1989 (ECA) lack substantive management and preventative measures. It was only in the later EMP’s (between the years 2000 - 2004) that the prescribed management measures improved and became more effective. This was because the Environmental Impact Assessment (EIA) process had matured in South Africa and an entire new regime of more descriptive EIA regulations had been promulgated under the National Environmental Act No. 107 of 1998, which repealed the majority of the outdated ECA regulations. It was also found that the environmental standards, management objectives and priorities that were developed in the EMP’s did not contingently and specifically reflect the conditions in relation to the environmental, developmental and biodiversity contexts to which they apply. The Closure plan on the other hand, was a regurgitation of the same unimaginative objectives focusing on remedying past legacies instead of providing a lasting solution to sustain and improve the environmental conditions left by the mine, and most importantly it does not address the social issues that result from mine closure. For example, the overexploitation and overgrazing of the areas in between the various mining operations by the Royal Bafokeng Nation’s people is a crucial aspect that has not been thoroughly addressed in the respective documents. Habitat disturbance, which was not addressed for instance, requires a wide range of actions e.g. educating local communities on pasture management, post–rehabilitation monitoring, amelioration etc. To improve compliance with current legislation and adherence to the guidelines proposed by best practice initiatives, various recommendations are put forward to control both the negative activities brought on by the Royal Bafokeng and Impala Platinum. These include the implementation of: Biodiversity (inclusive) impact assessment, good environmental governance, the precautionary approach, the ecosystems approach, sustainable biodiversity management practices through conservation planning, biodiversity action plans, stewardship and land care tools, conservation plans, biodiversity offsets, effective mine closure planning and the forming of a Biodiversity Action Steering Committee (BASC). Finally, an eight step model is proposed as a tool to evaluate the effectiveness of specifically the platinum mine’s EMP’s and Closure plans to manage activities affecting biodiversity. The model is based on the concepts of direct and indirect drivers of change and the Deming cycle and is an elaboration of the model proposed by UNEP and the International Association of Impact Assessment. The model focuses on both the natural and anthropogenic drivers that may affect biodiversity and will aid the management of a mine to supplement the shortcomings of these documents. As an indirect outcome the model may possibly even improve, the relationship between the specific company and the communities with which it shares its land. / Thesis (M. Environmental Management)--North-West University, Potchefstroom Campus, 2012.
218

The Role of Mechanically Gated Ion Channels in Dorsal Closure During Drosophila Morphogenesis

Hunter, Ginger January 2012 (has links)
<p>Physical forces play a key role in the morphogenesis of embryos. As cells and tissues change shape, grow, and migrate, they exert and respond to forces via mechanosensitive proteins and protein complexes. How the response to force is regulated is not completely understood. </p><p>Dorsal closure in Drosophila is a model system for studying cell sheet forces during morphogenesis. We demonstrate a role for mechanically gated ion channels (MGCs) in dorsal closure. Microinjection of GsMTx4 or GdCl<sub>3</sub>, inhibitors of MGCs, blocks closure in a dose-dependent manner. UV-mediated uncaging of intracellular Ca<super>2+</super> causes cell contraction whereas the reduction of extra- and intracellular Ca<super>2+</super> slows closure. Pharmacologically blocking MGCs leads to defects in force generation via failure of actomyosin structures during closure, and impairs the ability of tissues to regulate forces in response to laser microsurgery.</p><p>We identify three genes which encode candidate MGC subunits that play a role in dorsal closure, <italic>ripped pocket</italic>, <italic>dtrpA1</italic>, and <italic>nompC</italic>. We find that knockdown of these channels either singly or in combination leads to defects in force generation and cell shapes during closure. </p><p>Our results reveal a key role for MGCs in closure, and suggest a mechanism for the coordination of force producing cell behaviors across the embryo.</p> / Dissertation
219

Knowledge, Organization and the Division Of Labour: Evaluating the Knowledge Class in Canada

Scholtz, Antonie 13 August 2013 (has links)
This dissertation explores the claim that, in advanced capitalist countries like Canada, a powerful knowledge class is assuming increasing dominance within the social relations of production. Attached to such theories are claims of trends toward post-bureaucratic organizations, rising job complexity and autonomy, and increased power within operational and strategic decision-making processes. In my study I focus on Canadian “specialist” employees (professionals and semi-professionals) and managers. I present aggregated and disaggregated data from two Canadian surveys conducted in 1983 and 2004 and complement this with original interviews with information technology (IT) workers and engineers. I find a seeming paradox within the labour process of specialists and managers, with task-level autonomy declining even as job complexity and involvement in organizational decisions are rising. I provide evidence that imperatives for profit/cost effectiveness are leading to efforts to make specialist and managerial labour and knowledge more transparent, integrated, and manageable, but this is not the same as degradation or proletarianization. In contrast to my expectation, I find boundaries in the division of labour are durable despite this “socialization” of many labour processes. I argue that a specialist-and-managerial class (SMC) exists in Canada, and will continue to exist, though it is subordinate to and exploited by the capitalist elite even as it excludes and exploits the working class through occupational closure and credential barriers. The SMC is thus contradictory, internally heterogeneous and fraying at its borders, but simultaneously resilient. The resiliency comes via possession of specific strategic knowledge and consequent ability to secure rents and/or control specific organization assets via delegated authority. Resiliency is also structural, with management in many organizations retaining an interest in separating planning and design (“conception”), on the one hand, from process and completion (“execution”), on the other, in order to maximize efficiency and productivity through more centralized control.
220

Knowledge, Organization and the Division Of Labour: Evaluating the Knowledge Class in Canada

Scholtz, Antonie 13 August 2013 (has links)
This dissertation explores the claim that, in advanced capitalist countries like Canada, a powerful knowledge class is assuming increasing dominance within the social relations of production. Attached to such theories are claims of trends toward post-bureaucratic organizations, rising job complexity and autonomy, and increased power within operational and strategic decision-making processes. In my study I focus on Canadian “specialist” employees (professionals and semi-professionals) and managers. I present aggregated and disaggregated data from two Canadian surveys conducted in 1983 and 2004 and complement this with original interviews with information technology (IT) workers and engineers. I find a seeming paradox within the labour process of specialists and managers, with task-level autonomy declining even as job complexity and involvement in organizational decisions are rising. I provide evidence that imperatives for profit/cost effectiveness are leading to efforts to make specialist and managerial labour and knowledge more transparent, integrated, and manageable, but this is not the same as degradation or proletarianization. In contrast to my expectation, I find boundaries in the division of labour are durable despite this “socialization” of many labour processes. I argue that a specialist-and-managerial class (SMC) exists in Canada, and will continue to exist, though it is subordinate to and exploited by the capitalist elite even as it excludes and exploits the working class through occupational closure and credential barriers. The SMC is thus contradictory, internally heterogeneous and fraying at its borders, but simultaneously resilient. The resiliency comes via possession of specific strategic knowledge and consequent ability to secure rents and/or control specific organization assets via delegated authority. Resiliency is also structural, with management in many organizations retaining an interest in separating planning and design (“conception”), on the one hand, from process and completion (“execution”), on the other, in order to maximize efficiency and productivity through more centralized control.

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