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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.
121

Water-Energy-Food-Ecosystem Nexus in the Inkomati-Usuthu Water Management Area, South Africa: A Systematic Review.

Chawiya, Aaron Bryce January 2023 (has links)
The growing importance to finding workable solutions to the problem of unsustainable and inefficient resource use cannot be overstated.  In the world facing one of its critical sustainability periods, efficient resource utilization to ensure sustainable development is a problem policymakers should grapple with at a loc, regional and local levels. Because of this, the Water-Energy-Food-Ecosystem (WEFE) nexus has seen a growing number of proponents and supporters worldwide.  This thesis examines the WEFE nexus and its relevance for sustainable resource management, focusing on South Africa’s Inkomati-Usuthu Water Management Area (IUWMA).  WEFE nexus criticizes existing sector-based approaches for their limited recognition of cross-sectoral linkages.  This thesis presents a systematic review of the WEFE nexus in the IUWMA, identifying policy gaps and making recommendations to enhance integrated resource and environmental management based on the WEFE nexus approach.  The findings highlight various factors affecting energy generation, agriculture, water quality and quantity, and ecosystem-related factors within the IUWMA.  The thesis also provides an overview of critical policies related to the WEFE nexus in the IUWMA, demonstrating coherence (or lack thereof) and environmental considerations, and international cooperation.  The implementation of the WEFE nexus policy faces opportunities in collaboration but challenges such as institutional barriers, knowledge gaps, and limited political will.  The IUWMA also presents a complicated case owing to its transboundary nature, to which special attention must be paid when considering WEFE nexus approaches.  The discussion emphasizes the need for a holistic WEFE nexus approach to avoid inefficiencies and conflicts and calls for strong governance structures and equitable resource allocation.  Implementing the WEFE nexus approach can foster collaboration, sustainable resource management, land resilience to climate change impacts with political support, regional cooperation, and stakeholder engagement.
122

Modelling and Assessment of Biomass-PV Tradeoff within the Framework of the Food-Energy-Water Nexus

Bao, Keyu 03 May 2023 (has links)
Food, water and energy are three essential resources for human well-being, poverty reduction and sustainable development. These resources are very much linked to one another, meaning that the actions in any one particular area often can have effects in one or both of the other areas. At the same time, an economy's shift towards climate neutrality requires a massive expansion of energy production from renewable sources. Among these ground-mounted photovoltaic (PV) and biomass will be expanded massively to meet the clean energy generation goal, simultaneously influence regional water and food availability and supply security. It is crucial to understand Food-Water-Energy Nexus (FWE) nexus during the energy transition. However, current studies have limitation both methodically (qualitative assessments) and spatially (aggregated data on a national level is more available). Firstly, a consistent share input data set in geographical format was created with the resolution of building/field. An energy simulation platform (SimStadt) was then extended with new workflows on biomass potential, ground-mounted PV potential, food demand/potential, and urban water demand. Combining with existing workflows on urban building heating/electricity demand and roof PV potential, the dissertation created a complete simulation environmental covering most-relating FWE topics in energy transition with consistent input and output structures at a fine resolution. Secondly, the most representative inter-linkage between ground-mounted PV and biomass on hinterland is investigated in details with the new tools. The output data of each field from ground-mounted PV and biomass workflows are linked and ranked according to the scenarios emphasizing PV yield, feasibility, profit, or biomass. The assessment and scenarios are applied at three representative German counties with distinguished land-use structures and geometries as case studies. Results show that current policies does not guarantee the technically efficient allocation of fields. The optimal technical strategy is to follow the individual market profit drive, which is very likely, at the same time for the social good, to achieve high PV yields with limited biomass losses and more significant crop water-saving effects. The local food, water, and energy demands are also included as a metric for resource allocation on the potential side. Besides focusing on the biomass-PV tradeoff simulation and analysis, pioneer works have also been done to test the transferability of the method in cases outside Germany, and the complement of urban solid waste to agricultural biomass is explored to achieve energy autarky.
123

The Water-Energy-Agriculture nexus in Jordan : A case study on As-Samra wastewater treatment plant in the LowerJordan River Basin

Belda Gonzalez, Alberto January 2018 (has links)
Historically, water, energy and agricultural resources have been naturally scarce in Jordan, but current economic, demographic, geopolitical and environmental conditions are aggravating the situation. The influxes of refugees are increasing the already high natural population growth; better economic conditions and living standards are changing consumption and production patterns; surrounding conflicts affect the supply of resources; and negative effects associated to climate change can be noticed already. Therefore, nexus thinking as a basis for integrated and cross-sectorial natural resources management is essential to achieve water, energy and food security, and eventually to move towards a sustainable development of the country. To that end, understanding the existing nexus interlinkages is crucial. This document constitutes a first nexus approach focused on water, energy and agriculture (WEA) sectors in Jordan. The research has adopted a case study method based on literature review to consider different contextual factors, and three levels of study were regarded: national level, Lower Jordan River Basin within Jordanian borders level, and As-Samra WWTP level, which has constituted the case study. Based on an extensive literature review that has resulted in an updated analysis of the current Jordanian context, the main WEA nexus interlinkages have been identified at every level of study. Thirteen future alternative pathways have been proposed, their potential impacts on WEA nexus sectors have been investigated, and related indicators to evaluate these impacts have been suggested. Additionally, three combined pathways have been analyzed in detail. In general, results show that interdependencies between WEA sectors at all levels are strong and projected to intensify in the future, and highlight the critical situation of Jordan in terms of resource management. Inefficiencies and unsustainable uses of natural resources stand out as decisive problems that urge to be solved, and future pathways appear to be potentially harmful for the Jordanian system unless they are included in an integrated nexus-based planning. / Historiskt sett har vatten-, energi- och jordbruksresurser varit naturligt begränsade i Jordanien, men de nuvarande ekonomiska, demografiska, geopolitiska och miljöbetingade förhållandena förvärrar situationen. Inkommande flyktningar ökar den redan höga populationsökningen; bättre ekonomiska förutsättningar och levnadsstandarder ändrar konsumtion- och produktionsmönster; kringliggande konflikter påverkar utbudet av resurser; och negativa effekter associerade med klimatförändringar är redan tydliga. På denna grund så är Nexus en god grund för integrerad och tvärsektoriell förvaltning av naturresurs och vital för att säkerställa resurser för vatten, energi och mat och eventuellt gå mot en hållbar utveckling inom landet. För att åstadkomma det ovannämnda så är förståelse för nuvarande nexus samband avgörande. Denna studie utgör ett tillvägagångssätt för en nexus studie med fokus på vatten, energi och jordbruk (WEA) sektorerna i Jordanien. Arbetet utgår från en fallstudie och baseras på en litteraturstudie som är gjord på tre olika nivåer: nationell, Lower Jordan River Basin inom gränserna av Jordanien och As-Samra vattenreningsverk, sistnämnda utgör fallstudien. Baserat på en omfattande litteraturstudie som resulterat i en uppdaterad analys av Jordaniens situation, så har de huvudsakliga WEA nexus sambanden identifierats för varje nivå. Tretton framtida alternativa utfall har föreslagits, deras potentiella påverkan på WEA sektorerna har undersökts och relaterade indikatorer har föreslagits för att utvärdera deras påverkan. Vidare, tre kombinerade utfall har utvärderats i detalj. Överlag så visar resultaten på starkt ömsesidigt beroende mellan WEA sektorerna på alla nivåer och är beräknad att intensifieras i framtiden, vilket betonar den kritiska situationen Jordanien befinner sig i med avseende på naturresurshantering. Ineffektivt och ohållbart utnyttjande av naturresurser står ut som ett stort problem som kräver en lösning, och framtida utfall tycks vara potentiellt skadliga för Jordanien om de inte inkluderas i en integrerad planering baserat på ett nexus tillvägagångssätt.
124

Towards a more coherent approach to peacebuilding : Mine action paving the way for ex-combatant reintegration in the case of Colombia

Kamoun, Sara January 2022 (has links)
There is a growing awareness among researchers, policy-makers, and practitioners regarding the importance of increased coordination among numerous post-conflict peacebuilding processes and the consequent need for conceptual clarity as a precondition for coordinated, holistic peacebuilding interventions. Disarmament, demobilization, and reintegration (DDR), and Mine Action are among the very first entry points in post-conflict reconstruction, however, despite sharing similarities they form part of distinct communities of practice, and the nexus between the two remains widely unaddressed academically and in practice. This research aims to address this disconnection. A particular window of opportunity is identified through the difficulties that DDR reintegration generates.  In particular, this study proposes the reintegration of ex-combatants through mine action. The author suggests that DDR can only enable sustainable long-term results if it is part of a wider set of security promotion strategies with devoted attention to community security which is argued to be achieved through mine action. Using a qualitative single case idea analyses the research argues that the adoption of a bottom-up approach provides an alternative understanding of ex-combatant reintegration. The results suggest that Humanitarian Demining, Explosive Ordnance Risk Education (EORE) and Victim assistance (VA) can pave the way for reintegration and reconciliation between ex-combatants and local communities in the case of Colombia.
125

The Man-Environment Nexus in Morocco : A Qualitative Study of Hegemonic Masculinity Norms and Attitudes Towards Pro-Environmental Behavior amongst Male University Students in Rabat, Morocco

Jilg, Mathilda January 2023 (has links)
Whilst several studies acknowledge the role of gender norms and structures in environmental research, little attention is paid to the explicit influence of men and masculinities in pro-environmental behavior. Additionally, research concerning this man-environment nexus is almost nonexistent in the context of the Global South. This thesis aims to address this research gap by analyzing the influence of hegemonic masculinity norms on the attitudes of male university students in Rabat, Morocco to engage in pro-environmental behavior. The research is conducted by qualitative semi-structured focus group interviews with 15 male university students in Rabat during May and June 2023, with a theoretical framework drawing upon Martin Hultman and Paul M. Pulé’s theoretical efforts of Ecological Masculinities. The findings suggest that the contextual hegemonic masculinity norms socialize the respondents into internalizing a myopic approach to engaging in pro-environmental behavior; materializing into either anti-environmental attitudes or, more prominently, techno-scientific solutionist attitudes. Relatedly, the respondents dismiss engaging in the individual pro-environmental behaviors considered feminine in order to avoid judgements, social exclusion and demasculinization. The thesis concludes by delineating the importance of including men and multiple masculinities in environmental research, especially as men can be considered the gatekeepers to transformative climate change adaptation and mitigation.
126

A GIS-Based Simulation Method for Regional Food Potential and Demand

Bao, Keyu, Padsala, Rushikesh, Coors, Volker, Thrän, Daniela, Schröter, Bastian 05 May 2023 (has links)
A quantitative assessment of food-water-energy interactions is important to assess pathways and scenarios towards a holistically sustainable regional development. While a range of tools and methods exist that assess energetic demands and potentials on a regional scale, the same is not true for assessments of regional food demand and potential. This work introduces a new food simulation workflow to address local food potential and demand at the regional level, by extending an existing regional energy-water simulation platform. The goal of this work is to develop a GIS-based bottom-up approach to simulate regional food demand that can be linked to similarly GIS-based workflows assessing regional water demands and energetic demands and potentials. This allows us to study food-water-energy issues on a local scale. For this, a CityGML land use data model is extended with a feed and animal potential raster map as well as a soil type map to serve as the main inputs. The workflow simulates: (1) the vegetal and animal product food potentials by taking climate, crop type, soil type, organic farming, and food waste parameters into account; (2) the food demand of vegetal and animal products influenced by population change, body weight, age, human development index, and other indicators. The method is tested and validated in three German counties with various land use coverages. The results show that restricting land used exclusively for energy crop production is the most effective way to increase annual food production potential. Climate change by 2050 is expected to result in annual biomass yield changes between −4% and 2% depending on the region. The amount of animal product consumption is expected to rise by 16% by 2050, while 4% fewer vegetal products are excepted to be consumed.
127

Creative Musical Improvisation in the Development and Formation of NEXUS Percussion Ensemble

Piedra, Olman E. 14 April 2014 (has links)
No description available.
128

ELECTRON EMISSION THEORIES FOR MULTIPLE MECHANISMS AND DEVICE CONFIGURATIONS

Adam M Darr (13140378) 22 July 2022 (has links)
<p>  </p> <p>Electron emission plays a vital role in many modern technologies, from plasma medicine to heavy ion beams for fusion. An accurate theoretical model based upon the physics involved is critical to efficient operation of devices pushing the boundaries of complexity. The interactions between different electron emission mechanisms can severely alter device performance, especially when operating in extreme conditions. This dissertation studies electron emission from the perspectives of increasing geometric and physical mechanism complexities </p> <p>One half of this dissertation derives new relations for space-charge limited emission (SCLE) in non-planar geometries. SCLE is the maximum stable current that may be produced by electron emission before the electric field of the electrons themselves self-limits further emission. In planar devices, this is modeled by the well-established Child-Langmuir (CL) equation. The Langmuir-Blodgett (LB) equations remain the most commonly accepted theory for SCLE for cylindrical and spherical geometries after nearly a century; however, they suffer from being approximations based on a polynomial series expansion fit to a nonlinear differential equation. I derive exact, fully analytic equations for these geometries by using variational calculus to transform the differential equation into a new form that is fully and exactly solvable. This variational approach may be extended to any geometry and offers a full description of the electric field, velocity, and charge density profiles in the diode. </p> <p>SCLE is also an important mechanism for characterizing the operation of devices with an external magnetic field orthogonal to the electric field. This “crossed-field” problem decreases the limiting current as electrons travel longer, curved paths, effectively storing some charge in the gap (moving parallel to the emitter). At a critical magnetic field called the Hull cutoff, electron paths become so tightly curved that the circuit can no longer be completed, a condition called magnetic insulation. Crossed-field SCLE has been accurately modeled in planar devices by Lau and Christenson. Using the variational approach, I replicate their planar results and extend the calculation to cylindrical geometry, a common choice for magnetron devices. Further, I derive additional equations with simplified assumptions that, for the first time, provide an analytic description of experimental results below the Hull cutoff field. Following this I incorporate a series resistor: device resistance (or impedance) changes non-linearly with current and voltage, so I couple Ohm’s Law (OL) to all the models of crossed-field devices. For devices just below the Hull cutoff, I predict analytically and show in simulation novel bi-modal behavior, oscillating between magnetically insulated and non-insulated modes. With crossed-field device assessment, the variational calculus approach to space-charge may be used for numerous applications, including high power microwave sources, relativistic klystron devices, heavy ion beams, Hall thrusters, and plasma processing. </p> <p>The other half of this dissertation derives analytic theories to solve for emission current with three or more electron emission mechanisms simultaneously. In addition to the CL law, SCLE may also occur in neutral, non-vacuum diodes, modeled by the Mott-Gurney (MG) equation. These are the two limiting mechanisms I study; the other major modality of electron emission is direct electron production, the source of current in the device. Electrons are ejected when impelled by high temperature or electric field at the emission surface. These mechanisms are thermionic (or thermal) emission, modeled by the Richardson-Laue-Dushman (RLD) equation, and field emission, modeled by the Fowler-Nordheim (FN) equation, respectively. Additionally, just as I calculated the impedance of devices operating in a crossed-field configuration, all these models can be similarly coupled to OL. I derive models unifying FN, MG, and CL (with an extension linking OL, mentoring an undergraduate) and RLD, FN, and CL. These models are relevant for modern device design, especially as micro- and nano-scale devices seek to eliminate vacuum requirements and as space and military applications require higher temperature tolerances.</p> <p>While multi-physics models, like the ones described above, are important, the single-physics models (FN, RLD, MG, CL, OL) are still valid (and much easier to use) in their respective asymptotic limits. For example, a circuit behaves purely according to OL for very high resistances, according to MG for very high pressures, and so forth. Importantly, when devices operate in transition regions between these asymptotic limits, <em>none </em>of the asymptotic equations match the predictions of multi-physics models. Yet, intersections between the asymptotic equations are easily found, say for a certain set of voltage, gap distance, and pressure, CL=MG. Since both asymptotic equations give the same prediction, we may conclude that both must be inaccurate for those physical parameters! This gives rise to what I term “nexus theory:” solving two or more asymptotic equations simultaneously to rapidly and accurately predict sets of physical parameters at which multi-physics models (specifically, the physics leading to the “nexus point” parameters, points or curves at which nexus conditions are satisfied) are required for accurate device predictions. In fact, I show that multi-physics models are necessary within roughly one to two orders of magnitude from a nexus. In effect, nexus theory provides a simple, powerful tool to determine how complex a model is necessary for a particular device. Both nexus theory and multi-physics results in this dissertation have been successfully used to design devices to operate in specific transition regimes and identify the resulting device behavior.  </p>
129

The Relationship between Social Sustainability and Financial Performance : A quantitative study looking at the Social Pillar of ESG in the Nordic countries

Singh, Nathalie, Sørensen, Jonas January 2024 (has links)
This thesis aims to investigate the relationship between social sustainability and financial performance in Nordic large and mid-cap firms. Lately, there has been an increasing focus on ESG factors, however previous studies of the ESG factors’ relationship to financial performance have given mixed results. Moreover, in previous studies, the focus on social sustainability has fallen behind compared to the environmental and governance pillars. Therefore, the study analyses the relationship between the social pillar of ESG and financial performance, as well as the 4 social subcategories making up the social pillar. Thereby making the study a multi-ESG level study during the period 2018-2022. The study relies on a sample of 136 Nordic firms (123 for the ROE models) extracted from the LSEG database and tests the relationship between social sustainability and financial performance using nine panel regression models. Our findings are mixed, some showcasing negative, positive, and insignificant results. We find the social pillar of ESG to be a negative predictor of ROE, the social category of product responsibility was found to be a positive predictor of Tobin’s Q, and finally, the category of human rights was found to be a negative predictor of ROE. The other ESG variables were found to be insignificant as predictors of financial performance. The study thereby contributes to the research by investigating the under-researched pillar of sustainability, i.e. social sustainability, as well as shedding a light on the relationship in a Nordic context.
130

Challenges and Counter-Strategies for Engaging Stakeholders in Water-Energy-Food Nexus Decision-Making Processes

Kipruto, Brian January 2024 (has links)
Global environmental challenges have become more prevalent in the Anthropocene, with the cross-cutting nature of global challenges necessitating a unique way of looking at resource streams. The Water-Energy-Food Nexus (WEF Nexus) provides a conceptual framework for highlighting scarcity concerns and interdependencies between the three natural resource streams. However, stakeholders in the WEF nexus sectors tend to operate at different temporal and spatial scales and existing governance structures are plagued by disproportionate stakeholder contributions and unclear strategic goals. This thesis uses a systematic literature review and expert interviews to evaluate stakeholders' contribution in WEF nexus decision-making processes. A social-constructivist approach is adopted to conduct a thematic analysis of relevant articles and expert interviews with two main focuses. First, identifying the challenges of engaging public, private and civil society stakeholders in WEF nexus decision-making processes and second, developing counterstrategies to the identified challenges. The analysis shows that external influences, coordination challenges, process asymmetries, structural asymmetries and nexus cognition are challenges that underpin WEF decision-making processes. As a result of these challenges, decision-making processes are plagued by reduced trust, stakeholder fatigue, power imbalances and disproportionate nexus understanding. The analysis also develops solutions based on implemented practices and recommendations from prospective remedies. The discussion links the findings to broader debates on mainstream media communication, power asymmetries and participatory processes. Therefore, this thesis demonstrates that engagement challenges can be understood through collaborative governance and WEF nexus governance and that counterstrategies exist both in current practices and as future recommendations

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