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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.
1

Exploring the adoption rationales and effects of off-grid renewable energy access for African youth: a case study from Tanzania

Rabenold, Colton January 2020 (has links)
In addition to being one of the poorest countries in Africa, Tanzania is considered the 13th most vulnerable nation in the world to climate change and climate variability. Currently over 63% of Tanzanians have no access to the national power grid. Instead they rely on biomass and kerosene lamps to provide energy in their homes. In addition, rural youth in Tanzania have limited occupational pursuits other than subsistence farming (both formal and informal). Utilizing a case study approach, this research qualitatively explores the effects of energy access in the form of solar PV for those seeking to secure this public good at a household-level. Face-to-face interviews conducted in the coastal region of Tanzania concentrated on understanding rationales for adopting off-grid energy (adoption rationales), particularly respondent's 'Awareness', 'Motivation' and selected 'Pathways' (the AMP Framework). High rates of rural poverty highlight systemic lack of energy access in Tanzania. In contrast, livelihood transformations through solar PV were observed in the case to couple with energy access. Indicators of improvement in living standards were observed to have cascading influence on other adopters which, in turn, encouraged further uptake. This innovative adoption lead to decreased pressure on the surrounding ecosystems, but environmental factors did not influence initial adoption rationales. Reflecting on the findings, the author develops a framework for better understanding of the role private actors take in transitions from to off-grid energy access in Africa. Reflecting on the case observations, particularly how respondents sought shape the flow of events independent, and sometimes in spite of, the State, the framework extends current understandings of nodes of change in rural communities and provides a more extensive exploration of behavioural theories (the AMP Framework and Diffusion Theory). Novel connections are made conceptually with emerging nodes of change and decision-making theories of change to provide fresh extension of these approaches to understanding poverty arrangements in Africa and what researchers and decision makers might need to consider for targeted interventions towards universal energy access on the continent. The thesis concludes with a range of principles for energy access in Africa distilled from the observations and framework developed. They include environmental principles of sustainable resource management and socioecological balance, social principles of equality and participation, and economic principles of access and stability.
2

Traditional Peoples and the Struggle for Land in the Amazon Basin

Tucker, Catherine M. January 1996 (has links)
Current processes of deforestation and development in the Amazon Basin continue historical trends that have devastated indigenous populations and drastically reduced their land rights. While protection of the Amazon ecosystem has become a worldwide concern, many indigenous and folk groups employ forest management strategies that utilize natural resources without causing permanent degradation. This paper considers historical, political and socioeconomic circumstances that threaten the survival of indigenous groups and their sustainable forms of forest use. The paper argues that discrepant cultural models and attitudes contribute to the differences in land use between traditional Amazon residents and newcomers. The problems and possibilities entailed by efforts to protect traditional land rights are also discussed.
3

Material Footprint Assessment in a Global Input-Output Framework

Giljum, Stefan, Bruckner, Martin, Martinez, Aldo 30 December 2014 (has links) (PDF)
Material flow-based indicators play an important role in indicator sets related to green and resource-efficient growth. This paper examines the global flows of materials and the amounts of materials directly and indirectly necessary to satisfy domestic final demand in different countries world-wide. We calculate the indicator Raw Material Consumption (RMC), also referred to as Material Footprint (MF), by applying a global, multi-regional input-output (MRIO) model based on the GTAP database and extended by material extraction data. We examine world-wide patterns of material extraction and materials embodied in trade and consumption, investigating changes between 1997 and 2007. We find that flows of materials related to international trade have increased by almost 60% between 1997 and 2007. We show that the differences in Material Footprints per capita are huge, ranging from up to 100 tonnes in the rich, oil-exporting countries to values as low as 1.5 to 2 tonnes in some developing countries. We also quantify the differences between the indicators Domestic Material Consumption (DMC) and RMC, illustrating that net material exporters generally have a DMC larger than RMC, while the reverse is observed for net importers. Finally, we confirm the fact that most countries with stable or declining DMCs actually show increasing RMCs, indicating the occurrence of leakage effects, which are not fully captured by DMC. This challenges the world-wide use of DMC as a headline indicator for national material consumption and calls for the consideration of upstream material requirements of international trade flows.
4

Consumption-based material flow indicators - Comparing six ways of calculating the Austrian raw material consumption providing six results

Eisenmenger, Nina, Wiedenhofer, Dominik, Schaffartzik, Anke, Giljum, Stefan, Bruckner, Martin, Schandl, Heinz, Wiedmann, Thomas, Lenzen, Manfred, Tukker, Arnold, Arjan, de Koning January 2016 (has links) (PDF)
Understanding the environmental implications of consumption and production depends on appropriate monitoring tools. Material flow accounting (MFA) is a method to monitor natural resource use by countries and has been widely used in research and policy. However, the increasing globalization requires the consideration of "embodied" material use of traded products. The indicator raw material consumption (RMC) represents the material use - no matter where in the world it occurs - associated with domestic final demand. It provides a consumption-based perspective complementary to the MFA indicators that have a territorial focus. Several studies on RMC have been presented recently but with diverging results; hence, a better understanding of the underlying differences is needed. This article presents a comparison of Austrian RMC for the year 2007 calculated by six different approaches (3 multi-regional input-output (MRIO) and 3 hybrid life-cycle analysis-IO approaches). Five approaches result in an RMC higher than the domestic material consumption (DMC). One hybrid LCA-IO approach calculates RMC to be lower than DMC. For specific material categories, results diverge by 50% or more. Due to the policy relevance of the RMC and DMC indicators it is paramount that their robustness is enhanced, which needs both data and method harmonization.
5

Nouveaux matériaux photo-réparables à base d'huile végétale. / Titre en anglais non fourni

Geelhand de Merxem, Ludovic 04 April 2019 (has links)
Un revêtement photoréparable à base de 4 constituants, dont de l’huile de lin époxydée et du disulfure de 4,4’-diphényldiamine, a été élaboré via une réaction époxy/amine selon un procédé en deux étapes. Le caractère photoréparable est assuré par la présence de ponts disulfures qui, sous irradiation UV, peuvent être photolysés de manière réversible. Le revêtement obtenu renferme environ 46% en masse de composés biosourcés et 24% en masse de molécules photosensibles. Comparé à un matériau homologue sans pont disulfure, ce revêtement présente une densité de réticulation plus faible et un allongement à la rupture plus élevé. Une réparation significative d’un endommagement de 100 μm de profondeur a pu être réalisée. Un recouvrement de 42% de l’allongement à la rupture a ainsi été observé en seulement 3h d’irradiation UV a 100°C. / A biobased photohealing coating has been developed from 4 components, including epoxidized linseed oil and 4,4’- diphenyldiamine disulfide. The process has been carried out in two steps via an epoxy/amine reaction. The photohealing character is ensured by the presence of disulfide bridges which, under UV irradiation, can be photolyzed reversibly. The obtained coating contains about 46 wt-% of biobased compounds and 24 wt-% of photosensitive molecules. Compared to an analogous material without disulfide bond, the coating exhibits a lower crosslinking density and a higher fracture elongation.A significant repair of a 100 μm depth scratch has been occurred. An increase of 42% of tensile strength has been observed in only 3 hours of UV irradiation at 100°C.
6

Sustainable energy management for a small rural subdivision in New Zealand : a thesis presented in fulfilment of the requirements for the degree of Master of Technology in Energy Management, Massey University, Palmerston North, New Zealand

Armstrong, Amanda S. January 2009 (has links)
An eight-lot residential subdivision in central Wairarapa is being developed to demonstrate the principles of sustainable resource management. Local energy sources for low and high grade use, including electricity sourced from proposed grid-integrated, on-site, distributed generation will supplement imported network electricity. A unique component is an internal loop grid for lot connection that interfaces with the local network through a single connection point. A decision model was designed as a decision-support tool for the development based on the annual supply-demand electrical energy balance, site infrastructure covenants and a range of economic and technology criteria. Solar and wind resources were assessed for potential supply of electricity to the community energy system. Three demand profiles were developed using supplied and estimated electrical demand data; and included assumptions on thermal performance of the houses, the use of low-grade heat, user behaviour, and appliance use. Supply and demand were analysed as daily average profiles by hour for each month of the year. The decision model outputs were designed to give a graphic view of the system options. The accompanying output datasets also enabled a number of scenarios for connection configurations, load management, and economic sensitivity to be explored for their impact on the communal approach to managing energy. The viability of the community energy system is significantly influenced by managing demand level in conjunction with system size, capital cost management, and tariffs for electricity import and export. Energy requirements could be best met in the short term by installing a site-wide mixed generation system of sized capacity between 5 and 11kW, supported by metering and information technology to deliver management data to the residents. Future research opportunities exist to continue monitoring technical, economic and social outcomes from this unique community development. Incentivising private investment in userfocussed energy innovations is an option for New Zealand to consider in the current climate of market-driven large scale electricity developments.
7

Quelles méthodes pour la gestion durable de la ressource des plantes aromatiques et médicinales ? : Analyse des inventaires historiques en Albanie, modélisation des habitats à partir des traces GPS des cueilleurs et construction d’un observatoire / What methods for the sustainable management of the resource of medicinal and aromatic plants? : Analysis of historical inventories in Albania habitat modeling using GPS traces pickers and the construction of an observatory

Hoxha, Valter 16 December 2014 (has links)
Les plantes aromatiques et médicinales en Albanie constituent un secteur économique qui exerce de fortes pressions sur la ressource naturelle et entraine la dégradation des habitats des plantes, voire même les expose à des risques d'extinction. L'objectif global de la thèse est de proposer de nouvelles approches complémentaires pour améliorer la base de connaissance sur la ressource des PAM en Albanie. La première partie de la thèse traite du travail qu'il a fallu réaliser sur l'existant (inventaires et études) pour en tirer les enseignements et détecter les manques éventuels. Le travail sur les archives albanaises recouvrant la période allant de 1920 à 1986 et différentes études réalisées entre 1988 et 2010 ont permit de cerner les différents dispositifs de gestion de la ressource. Une partie des données historiques exploitables a été rassemblée et structurée sous forme de base de données. La seconde partie de la thèse propose une méthode de modélisation de l'habitat exploitée à partir des traces GPS des cueilleurs en utilisant essentiellement des concepts issues de la « Time Geography ». La collecte de l'information repose sur une approche participative (crowdsourcing) associant les cueilleurs en tant que contributeur d'information. Les traces GPS sont traitées et analysées par un modèle qui met en œuvre un ensemble de filtres pour ne retenir que les portions de trace qui appartiennent à l'action de cueillette stricto sensu. Déterminer l'action de cueillette reviens à détecter indirectement l'emplacement d'une plante. L'application successive des filtres de la vitesse instantanée, de la densité spatio-temporelle, de la surface et de la moyenne des variations d'angles sert à modéliser la zone de cueillette (zc) qui par agrégation à différentes échelles permet de reconstituer l'habitat exploité. La construction du modèle théorique a été traduite en langage SQL et implémentée dans une base de données spatiale pour faciliter le traitement automatisé des données. Ce modèle a été testé sur trois types plantes : la sauge, le romarin et le tilleul. La comparaison des résultats de la modélisation, représentés sous forme de cartographies synthétiques, d'un côté, avec les données terrains (photos géoréférencées) de l'autre, ont permis de faire évoluer le modèle dans un premier temps et de valider les résultats dans un second temps. La construction d'une base de données capable d'intégrer le résultat du traitement des traces GPS et les données historiques d'archives, tout en les restituant sous forme de vues cartographiques ou statistiques permet de démontrer qu'il est possible de faire cohabiter et de croiser des données provenant de sources d'origine et de nature différente. Malgré un nombre d'expérimentions limités, le modèle couplé à la base de données «BD OPAM», jette les premières bases d'un observatoire préfigurant la gestion évolutive des PAM. / Medicinal and aromatic plants in Albania is an economic sector that exerts great pressure on the natural resource and causes the deterioration of the habitats of plants and even puts them at risk of extinction. The overall aim of the thesis is to provide new complementary approaches to improve the knowledge base on PAM resource in Albania. The first part of the thesis deals with the work that had to be made on the existing (inventories and studies) to draw lessons and identify potential gaps. The Work on the Albanian archives covering the period from 1920 to 1986 and various studies conducted between 1988 and 2010 have made it possible to identify the various devices of resource management. A harvestable part was collected as historical data and structured as a database. The second part of the thesis proposes a method of habitat modeling operated from GPS traces of the gatherers using mainly concepts from the "Time Geography." The collection of information is based on a participatory approach (crowdsourcing) involving gatherers as information contributor. GPS tracks are processed and analyzed by a model that uses a set of filters to select only those portions that belong to trace's action of picking in strict sense. Determine the action of gathering come back to indirectly detect the location of a plant. The successive application filters of the instantaneous speed, of the spatio-temporal density, of the surface and the mean variation of angles used to model the collection area (zc) that the aggregation at the different scales used to reconstruct the exploited habitat. The construction of the theoretical model has been translated into the SQL language and implemented in a spatial database to facilitate automated data processing. This model has been tested on three herbs: sage, rosemary and linden. Comparison of the results of modeling, represented as synthetic maps on one side, with the land data (photos georeferenced) on the other, have helped to change the model initially and validate results a second time. Building a database that can integrate the treatment outcome of GPS tracks and historical data archives, while restoring the form of map views or statistics used to demonstrate that it is possible to integrate and crossing data from sources of different nature and origin. Despite a limited number of experimenting, the coupled to the database "BD OPAM" model, laying the first foundations of a monitoring foreshadowing adaptive management of PAM.
8

Phosphorus Balance of Sweden / Fosforbalansen i Sverige

Wikberg, Karl Anders January 2019 (has links)
Phosphorus (P) is an essential element for all life on our planet. During the past century anthropogenic consumption of P has reached critically unsustainable levels, the mining of finite phosphate rock and the dispersion of this resource could lead to resource scarcity in the future. The need to increase knowledge and understanding for the P system is an essential part of sustainable decision making. In this thesis the P balance of Sweden is characterised and quantified using material flow analysis methodology. Furthermore, the study provides a solid foundation of knowledge and understanding of the current state of P balance in Sweden. Major challenges are highlighted and further improvement potential is established for the Swedish flows of P. The major identified contributors to the Swedish P balance are the consumption of mineral fertilizers, the consumption patterns in society and the waste management. Moreover, there is a need to reduce the emissions of P to the environment in order to preserve natural state. The most effective ways of reducing the emissions are to reduce inputs to the system and improve the system efficiency through technical solutions, political tools and financial incentives. It is important to reduce emissions without shifting of burdens onto others. The anthropogenic activities in Sweden have a significant impact on the environment, this is due to Sweden importing P fertilizer that is added to the system. Nevertheless, there is a large potential for improvement of P resource management, where recycling and reuse of P is highlighted. Furthermore, Sweden has historically proven that political action and financial incentives are effective in reducing emissions. / Fosfor (P) är ett väsentligt element för allt liv på vår planet. Under det senaste århundradet har den antropogena förbrukningen av P uppnått kritiskt ohållbara nivåer, brytning av begränsade mängder fosfatmalm som finns och spridningen av denna resurs kan leda till resursbrist i framtiden. Behovet av att öka kunskapen och förståelsen för P systemet är en väsentlig del av hållbart beslutsfattande. I denna avhandling karakteriseras och kvantifieras P balansen i Sverige med hjälp av metoder för materialflödesanalys. Dessutom ger studien en stadig grund för kunskap och förståelse för det nuvarande tillståndet för fosforbalansen i Sverige. Viktiga utmaningar lyfts upp och ytterligare förbättringspotentialer fastställs för de svenska flödena av P. De viktigaste identifierade påverkningsfaktorerna till den svenska P-balansen är konsumtion av mineralgödsel, konsumtionsmönstren i samhället och avfallshanteringen. Utöver detta, finns det ett behov av att minska utsläppen av P till miljön för att bevara ett naturligt tillstånd. De mest effektiva sätten att minska utsläppen är att minska tillförseln av P till systemet och förbättra systemeffektiviteten genom tekniska lösningar, politiska verktyg och ekonomiska incitament. Det är viktigt att minska utsläppen utan att förskjuta bördorna på andra. Den antropogena verksamheten i Sverige har en betydande påverkan på miljön, detta beror på att Sverige importerar P gödsel som läggs till systemet. Ändå finns det en stor potential för förbättring av P resurshanteringen, där återvinning och återanvändning av P framlyfts. Dessutom har Sverige historiskt bevisat att politiska åtgärder och ekonomiska incitament är effektiva för att minska utsläppen.
9

The cascade of uncertainty in modeling forest ecosystem responses to environmental change and the challenge of sustainable resource management

Reyer, Christopher 30 May 2013 (has links)
Projektionen der Effekte von Umweltveränderungen auf sozio-ökologische Systeme sind ein fester Bestandteil der Nachhaltigkeitsforschung. Solche Projektionen beruhen auf Modellen und Modellketten. In jedem Modellierungsschritt werden modelspezifische Unsicherheiten bezüglich Parameterwerten, Eingabedaten und Modelstruktur akkumuliert und führen zu einer Kaskade der Unsicherheiten. Ziel dieser Dissertation ist es, die Kaskade der Unsicherheiten der Wirkungen von Umweltveränderungen am Beispiel der Waldökosystemmodellierung zu behandeln. Dies führt zu zwei übergreifenden Forschungsfragen: 1. Wie beeinflussen unterschiedliche Typen von Unsicherheiten die Projektionen der Wirkungen sich verändernder Umweltbedingungen auf Waldökosysteme? 2. Gibt es einen übergeordneten Rahmen für nachhaltiges Ressourcenmanagement in sozio-ökologischen Systemen, in den Unsicherheiten eingebettet werden können? Diese Dissertation zeigt, dass die Produktivität von Wäldern unter Bedingungen des Klimawandels in kühleren und feuchteren Regionen zunehmen und in wärmeren und trockeneren abnehmen kann. Diese Ergebnisse sind qualitativ konsistent über eine Vielzahl von Modellstrukturen, Klimaszenarien und Modelparameter, die jedoch quantitativ zu nennenswerten Unsicherheiten in Projektionen führen. Diese Arbeit zeigt, dass es Methoden gibt, um bestimmte Unsicherheiten einzuschätzen, aber auch, dass viele Klimawirkungsstudien die Wirkung von Veränderungen im Mittelwert von Klimavariablen betrachten und nicht die von Extremwerten. Außerdem zeigt diese Arbeit, dass adaptive, sektorenübergreifende Strategien für ein nachhaltiges Ressourcenmanagement existieren, die mit Unsicherheiten von Klimawirkungen umgehen können und nachhaltige, regionale Entwicklungen fördern. Die Kaskade der Unsicherheiten ist eine zentrale Herausforderung für nachhaltiges Ressourcenmanagement. Eine systematischere Behandlung von Unsicherheiten ermöglicht robuste Projektionen der Wirkungen sich verändernder Umweltbedingungen. / Projecting the effects of environmental change on social-ecological systems is a crucial component of sustainability science. Such projections rely on models and modeling chains. At each modeling step, model-specific uncertainties about parameter values, input data or structure accumulate and lead to a cascade of uncertainty. The aim of this thesis is to explore the cascade of uncertainties in responses to environmental change in a structured way at the example of forest ecosystem modeling. This leads to two overarching research questions: 1. How do different types of uncertainties affect projections of the effects of environmental change on forest ecosystems? 2. What is the general framework of sustainable natural resource management in coupled social-ecological systems in which uncertainties need to be integrated? This thesis shows that forest productivity under climate change may increase in cool and wet regions and decrease in already warm and dry regions. These findings are robust despite large differences in model structure, climate change scenarios and model parameters that induce considerable uncertainty into future projections. It also stresses that there are methods available to assess uncertainties but also that many climate change impact studies have focused on testing the response of plants to changes in mean climate rather than climatic extremes. Finally, this thesis shows that adaptive, cross-sectoral natural resource management strategies exist that accommodate uncertain impacts of environmental and societal change and foster sustainable regional development. I conclude that the cascade of uncertainty challenges sustainable natural resource management and that a more systematic treatment of uncertainties is strongly needed to generate robust projections of the impacts of environmental change. The findings of this thesis provide a general framework in which both modelers and decision-makers can integrate model results and assess their robustness.
10

Assessment and management of environmental and socio-economic impacts of small-scale gold mining at Giyani Greenstone Belt

Magodi, Rofhiwa 18 September 2017 (has links)
MENVSC (Geography) / Department of Geography and Geo-Information Science / Artisanal and small-scale gold mining (ASGM) has devastating impacts on different parts of the environment and is a source of environmental degradation and contamination. ASGM degrades water resources, contaminate soil, sediments and water and lead to serious land degradation problems. ASGM activities are also associated with socio-economic issues such as child labour, prostitution and health and safety concerns. Insufficient understanding of the environmental and social problems of ASGM in Giyani Greenstone Belt has led to lack of mitigation strategies to reduce such problems. The main aim of this research was to assess and manage the environmental and socio-economic impacts of ASGM in Giyani Greenstone Belt. Remote sensing and GIS and Normalised Differential Vegetation Index were used to assess the effects of mining activities on vegetation cover. Assessment of the effects of ASGM on water, sediments and soil quality involved collection of samples in order to establish their physical and chemical properties. The concentration of toxic and trace metals were determined using Atomic Absorption Spectrometer (AAS) and X-ray Fluorescence (XRF) instruments. The pH meter was used to determine the pH level of the collected samples. Questionnaires, interviews and SPSS were used to assess socio-economic impacts of ASGM. The study culminated in devolvement of NDVI maps and this was used to assess the effects of ASGM on vegetation cover. Results showed that the mining activities in the area had caused extensive environmental degradation due to serious removal of vegetation cover in the site. ASGM had serious effects on soil, water and sediments quality such as environmental contamination by toxic and trace elements. Soil samples were found with high concentration of As, Cr, Cu, Ni, Pb and Zn as compared to the recommended South African Soil Quality and WHO threshold values for plants. It was found that Klein Letaba had high concentration of Ba, La, V, and Ce above the World Soil Averages for plants. Sediments were heavily contaminated with Cr, Ni, Pb, Zn, As and Ba as compared to the recommended standards prescribed by US EPA and WHO. The pH of water, soil and sediments samples collected from both mining sites were found to be strongly alkaline which affects the plants growth as well as aquatic flora and fauna. Socio-economic issues such as child labour, injuries, educational problems, health and safety issues, police disturbance, creation of jobs and income generation were identified at mine sites. ASGM had serious effect on vegetation cover through environmental degradation. ASGM also had serious environmental contamination by toxic and trace elements. ASGM had both positive and negative socio-economic issues at mining site which include employment opportunities, income generation, occupational health and safety, police disturbance and arrests and the use of child labour. Mine site rehabilitation is recommended in this study to reduce environmental degradation. The remediation of contaminated area by concentrated toxic and trace elements should be applied at both mining sites. ASGM should be legalised to enhance positive aspects of the mining such as increase in income generation and creation of more employment opportunities. However, there should be enforcement of mining policies to reduce social and environmental problems.

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