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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.
301

Providing Sustainable Life-solutions with a Hybrid Micro-Power Plant in Developing Countries: an Assessment of Potential Applications

Öncel, Melih, Marion, Gonzalo January 2013 (has links)
Today, energy access is a significant challenge all over the world, particularly in African countries. At the same time, providing energy access is generally accepted as a way to promote sustainable development. In countries such as Uganda, lack of energy access is evident. In this country only 9% of households have access to electricity. About 87% of these households are located in rural and remote areas. Thus, off-grid rural electrification solutions are required to supply electricity services to a significant part of the population.The ultimate objective of this thesis is to propose a specific solution to cover basic energy needs of the rural population considering environmental, social and economic benefits. How can sustainable life solutions be provided in rural areas, by using the energy surplus from a decentralized small-scale biomass gasification power plant? The analysis used as a starting point the Green Plant Concept, which considers the design of a sustainable off-grid platform that produces energy to provide life solutions and also to excite local entrepreneurship in the rural sites where it is implemented. The concept implies participation of the private sector – a telecommunication company – which is a unique feature in the context of rural energization.To develop our analysis, a field trip has been conducted in Uganda, Africa, to answer sub-questions such as How to reach a cost-effective system? How to adapt a business oriented approach to the community’s life-style in order to be well accepted? How to foster the development of the area by having a positive socio-economic impact on society? How to create an environmental friendly solution? How to achieve the maximum efficiency in terms of reusing waste? Tools such as Multi Criteria Analysis (MCA) and SWOT analysis were used to interpret collected information and identify impacts of the suggested solutions.The research has shown the great potential of the Green Plan Concept. We conclude by selecting three applications that can enhance the provision of basic energy needs while creating benefits for the stakeholders involved in the process: i) Mini-Grid solutions, ii) Battery Charging Stations and iii) Heat Pipe Exchangers. We also highlighted the relevance of bringing, in addition to appropriated technologies, different stakeholders together, considering their common interests.The research is finalized by estimating the payback period based on the current and expected energy consumption and the capital investment related to the suggested applications. It is important to highlight that the payback time estimations do not include the participation of the telecom companies. This means that the estimated payback period of 7 years could be significantly reduced by the inclusion of this stakeholder.
302

The Potential for Urban Anaerobic Digestion in Quelimane : A model and feasibility assessment of a small scale system implementation Minor Field Study

Rudén, Sophie, Stendahl, Matilda January 2016 (has links)
The Municipality of Quelimane, the fourth biggest city in Mozambique, aims to apply an EcoCity concept in the city. Therefore, the municipality initiated a waste-to-energy project in order to improve the lacking waste management, valorize resources and lessen the burden on the environment. The purpose of the current project was to investigate the potential for implementing a waste-to-energy system in Quelimane. In particular, the technology of anaerobic digestion. This technology had been identified as the best alternative based on local conditions according to a study performed by students at KTH, the municipality of Quelimane and GreenLight about waste-to-energy in Quelimane the spring of 2015. The present project was performed during eight weeks in Mozambique; five weeks in the capital Maputo and three weeks on-site in Quelimane, where the collection of data mainly was made in Quelimane. The gathered information resulted in a model for a small scale anaerobic digestion system in Quelimane. An assessment of the potential for an implementation of an anaerobic digestion system in Quelimane was determined using a feasibility assessment tool. The study was performed using the following methods: literature study, interviews, surveys, on-site observations, modelling and by using a feasibility assessment tool. The analysis performed with the feasibility tool identified the socio-cultural attitude towards the technology and the willingness among the residents to use the end products as key factors for a successful implementation. The attitude towards the technology was determined as mainly positive and the willingness to use the end product high. The strong involvement and initiative from the municipality were also identified as key factors and determined as positive. The environmental, policy and legal and the technological aspects of the system are other identified key factors were mainly identified as positive according to the feasibility assessment tool. However, there is currently no end user for the small scale plant and no established funding for the project. This altogether results in a current marginally high potential for the implementation of a small scale anaerobic digestion plant, with good chances to increase the potential in the future.
303

The contribution of small-scale timber farming in enhancing sustainable livelihood at Sokhulu

Jele, Zanele 05 1900 (has links)
Small-scale timber farming provides alternative income for growers selling to forestry, procurement companies and timber suppliers or agents. The research used focus groups and structured questionnaires in the Sokhulu area to determine the contribution of small-scale timber farming to enhance sustainable livelihood. The Sustainable Livelihood Framework measured livelihood levels of different grower types in terms of access to natural, human, financial, social and physical assets. Findings show that timber suppliers had a higher asset composition, than growers selling to companies or growers selling to timber suppliers. Households lacking access to forestry resources sold timber to agents and households wanting to avoid harvesting and transport risks sold timber to suppliers. Timber farming contributes income, employment and business opportunities towards alleviating poverty rather than providing a complete solution. Tree harvesting support households during financial hardship and reduce vulnerability through diversified livelihood strategies. Disadvantages include: trees taking time to mature while immediate income is required, trees exposed to natural hazards, cheating by local harvesting and transport contractors and timber plot sales sometimes do not receive the agreed price. Despite disadvantages, timber farming provide economic benefits and further studies are needed to determine income level on mature trees, by-product sales and whether higher prices for more tonnage will sustain households that wait for tree maturity, thereby determining optimal break-even point for rural timber farmers. / Environmental Sciences / M.A. (Human Ecolgy)
304

A Socio-Ecological and Economic Approach to Tropical tuna Fisheries in the Mozambique Channel

Nataniel, Anildo Naftal 27 September 2021 (has links)
En este estudio se analizan los efectos de las condiciones oceanográficas sobre la captura agregada de las tres principales especies de túnidos tropicales considerando las dos estrategias de pesca principales de la flota española de cerco, es decir, la pesca sobre dispositivo artificiales de agregación de peces (FADs) y banco libre (FSC). Además, para cada estrategia de pesca, se investiga el desplazamiento de la agregación de captura bajo los efectos del cambio climático utilizando la captura de atún Katsuwonus pelamis como indicador biológico, y se discuten las implicaciones sociales y económicas del impacto climático sobre los países costeros alrededor del Canal de Mozambique. El atún Katsuwonus pelamis es el recurso pesquero ecológico más importante que sustenta las necesidades sociales y económicas de los países costeros del MZC y, por tanto, las predicciones de puntos críticos para mediados y finales de siglo bajo diferentes escenarios de cambio climático son resultados que deben ser considerados en los planes de conservación y gestión de este recurso. Además, se analizaron las tendencias en las capturas de atún de las flotas industrial y artesanal y el impacto de su interacción. El objetivo general de esta investigación de tesis es mejorar nuestro conocimiento sobre los factores clave que impulsan la dinámica de las pesquerías de túnidos tropicales en el MZC, bajo un contexto que combina la acción e interacción de la flota de cerco industrial y la pesca a pequeña escala. Para el desarrollo del objetivo general, se han definido y resumido objetivos específicos de la siguiente manera: (i) investigar las relaciones entre los factores ambientales y la acumulación de cardúmenes de túnidos tropicales en hábitats marinos capturados por la flota Española de cerco sobre FADs o sobre FSC en el Canal de Mozambique; (ii) investigar la dinámica temporal y predecir los hábitats espaciales para la agregación de cardúmenes de túnidos o puntos críticos para la pesca en relación con sus preferencia ambientales;, (iii) investigar los cambios de distribución y agregación del Katsuwonus pelamis frente a los escenarios futuros de concentraciones representativas (RCP) de cambios climáticos para 2050 y 2100. (iv) discutir los cambios en las tasas de captura y socioeconómicos que afectan a las comunidades pesqueras considerando la incertidumbre asociada al cambio climático en el Canal de Mozambique; (v) describir las interacciones socioecológicas y socioeconómicas entre la pesca industrial y los sectores de la pesca en pequeña escala en las aguas costeras, en base a la información disponible de las pesquerías de Mozambique; (vi) explorar, desde el punto de vista ecológico, el efecto que ejercen la flota industrial en las poblaciones objetivo, así como el impacto socioeconómico en la pesca a pequeña escala, siendo esta, además, más vulnerable al cambio climático a lo largo de la costa de Mozambique. Los datos científicos utilizados en el análisis de capturas y esfuerzo de la flota española de cerco en el área del Canal de Mozambique se obtuvieron de las bases de datos del Instituto Español de Oceanografía (IEO) para el período de Febrero de 2003 a Junio de 2013 a partir de los cuadernos de pesca de la flota de cerco española, una vez corregida la composición específica de las capturas a partir de los datos detallados de la flota y el muestreo de puertos. Los datos de captura y esfuerzo de los cuadernos de pesca contienen información de los lances de pesca para FADs y FSC. Paralelamente a los datos de pesca, los datos ambientales para la misma subárea del MZC y el mismo periodo de tiempo se obtuvieron del consorcio MyOcean-Copernicus EU (marine.copernicus.eu) en formato netCDF. Finalmente, las conclusiones de estas tres etapas de investigación fueron las siguientes: (i) Entre las condiciones oceanográficas que determinaban los puntos críticos de captura para ambos tipos de pesca de cerco (FSC y FADs) en el canal de MZC se encontraban la temperatura de la superficie del mar y su variabilidad, la productividad, la altura de la superficie del mar y la las interacciones de las variables espaciales y temporales. Sin embargo, las corrientes geostróficas mostraron un efecto significativo solo para la acumulación de captura pescable en los FADs. El efecto dinámico de las variables oceanográficas ambientales sobre la acumulación de captura de túnidos tropicales a lo largo del Canal de Mozambique varía según el modo de pesca FAD y FSC. Los modelos predijeron hábitats preferidos para peces asociados con FADs entre 10ºS y 18ºS, con el núcleo, en general, en la costa noroeste de Madagascar. Las predicciones para el hábitat preferido en FSC muestran que el núcleo se encuentra principalmente en la parte norte del Canal de Mozambique y también cerca de la costa de Mozambique entre las latitudes 10ºS a 16ºS. El modelo predijo un caladero de pesca parcialmente superpuesto entre los FADs y la el FSC, a pesar de la diferencia en las variables oceanográficas seleccionadas por cada modelo aditivo generalizado para establecer hábitats de pesca preferidos a lo largo del canal de Mozambique.(ii) En relación de la captura de K. pelamis bajo el escenario climático, los hallazgos sugieren que las variables biofísicas afectan la distribución de las capturas de barrilete en el MZC y que la distribución de las especies se verá afectada por el cambio climático, particularmente en la parte norte, con posibles implicaciones en las comunidades pesqueras locales e internacionales. El modelo proyectó la distribución del K. pelamis e bajo escenarios de cambio climático optimista (RCP2.6) y pesimista (RCP8.5). El escenario optimista proyectaba que las capturas de K. pelamis se desplazarían hacia la parte sur del Canal de Mozambique, entre las latitudes 19ºS y 25ºS, para el 2050, y que el cambio de distribución sería menor o sin cambios entre 2050 y 2100. En el peor de los casos (RCP8.5), los caladeros potenciales de pesca se proyectaron en latitudes >20ºS para 2050, y se pronosticó que probablemente se producirían anomalías positivas en latitudes <20ºS entre 2050 y 2100. Además, para fines del siglo XXI, se observan signos de una alta distribución de las capturas. se espera fuera del MZC en latitudes >25ºS hacia las regiones templadas. Dado que se prevé que el cambio climático afectará la pesca de barrilete en el MZC, puede generar desafíos socioeconómicos para las comunidades pesqueras. Los estados costeros en el área de MZC deben fortalecer la gobernanza y promover políticas para construir resiliencia y aumentar la capacidad de adaptación de las pesquerías locales, nacionales y regionales para reducir su vulnerabilidad a los impactos climáticos. (iii) Las capturas nominales de atún han ido disminuyendo con el tiempo en Mozambique, independientemente de si los peces son capturados por flotas industriales o pescadores en pequeña escala. La competencia entre las flotas industriales y los pescadores en pequeña escala para maximizar las capturas y los beneficios de las especies de túnidos de alto valor comercial, como el rabil, el listado y el patudo hayan contribuido, muy probablemente, a generar esta tendencia decreciente, ya que los mismos stocks se capturan en diferentes regiones del océano Índico occidental (costa y alta mar) y por todo tipo de artes durante la migración estacional y espacial de las tres especies de túnidos tropicales. La existencia de tal interacción entre flotas industriales y pescadores locales a pequeña escala y la tendencia decreciente de los stocks tiene mayores consecuencias sobre los pescadores locales dada su mayor vulnerabilidad. Por lo tanto, es importante fortalecer la aplicación de la separación legal ya existente de las áreas de extracción entre la pesca artesanal e industrial. Es importante evitar la explotación excesiva del atún en las aguas nacionales de Mozambique y al mismo tiempo establecer acuerdos de pesca que apoyen el desarrollo socioeconómico del país. Los futuros acuerdos deberían ser socialmente justos, viable ecológicamente y estar respaldados por un buen asesoramiento de gestión sobre la sostenibilidad de las tasas de explotación.
305

Seeds of sustainability? : A case study on agricultural sustainability perceptions among small-scale farmers in the Manyara region, Tanzania / Uppfattningar om hållbart jordbruk : En fallstudie av småskaliga jordbrukare i Manyara-regionen, Tanzania

Tarvainen, Evelina January 2020 (has links)
Agricultural policies worldwide are giving an increased focus to the goal of sustainable agriculture, but there are still uncertainties around how this is performed and achieved. As small-scale farmers are a fundamental part of agricultural production worldwide, earlier scholars request deeper understanding of how these farmers perceive sustainable agriculture and how they perceive the pathway towards sustainability. In Tanzania, many small-scale farmers choose to participate in initiatives and organizations under the Organic Farming Movement. By focusing on small-scale farmers that have joined an organic initiative in the Manyara region in Tanzania, this study aims to interpret how these farmers perceive that joining the Organic initiative of a local seed trading system could contribute to sustainable agriculture for them. The study's theoretical approach was a framework where agricultural sustainability consists of an ecological, economic, and social dimension and that normative assumptions of sustainability can be divided into either an Environmentalist or Ecologist approach. Through an open-ended question survey, ten local farmers' perceptions of agricultural sustainability were collected. The result indicates that the farmers perceive that the local seed trading system to some extent will contribute to parts of all three dimensions of agricultural sustainability, and that normative assumptions in both Environmentalism and Ecologism can be identified within the farmer's answers.
306

Practices for co-productive planning modes: Urban development in Cape Town : A case study based on the implementation of a design and building development incubator / Tillämpning av samskapade planeringsstrategier inom stadsutveckling i Kapstaden : En fältstudie av implementeringen av en bygg- och designinkubator

Warsame, Idil January 2019 (has links)
Together with a steadily increasing urban population, South Africa and the city of Cape Town is facing continuously expanding informal settlements and communities with no access to basic human services or adequate housing. There’s an urgent need to design, plan and implement alternative and creative approaches to help stimulate an equal, inclusive and sustainable urban development and strategic spatial planning. Integrating methods and processes that includes participation, communication and collaboration by incorporating civil society and local community members in urban planning practices is one way of promoting sustainable and equal spatial growth. Co-production is a concept used in urban development theory that embraces this in and can be described as a communicative form of spatial planning where state, planners and citizens mutually interact in the planning process. In consideration of these challenges, this thesis aims to apprehend how marginalized, local communities in Cape Town can be included in matters regarding urban development and spatial planning practically and if co-production can be used to define and explain this form of approach. Therefore, this thesis is based on a case study research of the Better Living Challenge (BLC) incubator, a two-week long project in Cape Town, which supported 15 informal builders in improving and developing their designing, building and marketing skills. The practical implementation of this incubator and its process has been examined to determine if the theory of co-production can be used to outline the project and understand the results emerging from it. The incubator proved to be successful in several ways and was met with impressive feedback from the stakeholders. It was also followed with difficulties and restrictions like power dynamics and tension. The conclusions that were made highlights that the incubator can be defined as an alternative and unorthodox co-productive approach based on the aim and lay-out of the process.
307

Small-scale maize farmers' willingness to pay for changing planting dates in the face of climate change : a case study of Makhuduthamaga Local Municipality, Limpopo Province

Tau, Lekobane Lebogang January 2023 (has links)
Thesis (M.Sc. (Agricultural Economics)) -- University of Limpopo, 2023 / The agricultural sector plays an important role in South Africa regardless of the small contribution of 1.88% it has to the GDP of the Country. Small-scale maize farmers’ decisions to adopt adaptation options in response to climate change and variability are influenced by socioeconomic, institutional, and environmental factors, indicating that decision patterns can be very specific to a given locality. The study aimed to analyse the determinants of small-scale maize farmers’ willingness to pay for changing planting dates in the face of climate change. This study had two main objectives, to identify and describe the socio-economic characteristics of small-scale maize farmers, and to determine factors influencing the small-scale maize farmer’s willingness to pay for changing planting dates in the face of climate change in Makhuduthamaga Local Municipality. The study used primary data with a sample size of 150 small-scale maize farmers. Descriptive statistics and the Probit Regression Model were employed when analysing data. The study employed purposive sampling in the data collection process and three villages were selected. Probability was proportional to sample size and was used to select the number of small-scale maize farmers for the sample frame of each village. About 58% of the sampled small-scale maize farmers were willing to pay for changing planting dates in the face of climate change, as opposed to 42% of those not willing to pay for changing planting dates. Empirical results from the analysis reported that age (10%), educational level (1%), level of income (1%), years of farming (10%), total output (1%), exposure to climate information services (5%), and use of indigenous forecast (1%) out of twelve explanatory variables were found to be significant. Based on the empirical findings of the study it is recommended that government officials together with other stakeholders such as NGOs and research institutions should invest in the education of small-scale maize farmers through knowledge systems such as (presentations, conferences, seminars, abet etc). Government policies and strategic investment plans that support improved small-scale maize farmers’ accessibility to climate information are also recommended.
308

"Junk"

Milner, Meaghan January 2013 (has links)
No description available.
309

Small-scale Experiments for Blast-induced Damage: Exploring crack propagation through Digital Image Correlation

Rodriguez San Miguel, Carlota January 2024 (has links)
Blasting plays a crucial role in several engineering applications, from mining and tunneling to demolition projects. One of the remaining challenges of this process is that it can significantly affect the integrity of the rock mass by inducing damage in the form of cracks. Broadening the understanding of the behavior of the blast-induced cracks is essential for predicting the damage. One way of investigating this issue is through small-scale blasting experiments focused on crack propagation behavior. Controlled blasting experiments were conducted on rock-like cylindrical samples charged with Pentaerythritol tetranitrate (PETN) cords. Different blast designs were tested and a method for integrating a Digital Image Correlation (DIC) technique in the analysis was developed. The DIC system was composed of an Ultra High-Speed Camera (UHSC), a light system, and a data acquisition system. The setup was tested in a laboratory and underwent different calibrations before implementing it in the mine, where using explosives during the tests is allowed. The UHSC captured the blasting process regarding crack propagation. To analyze the development of the cracks, DIC technique was employed and results in terms of displacement versus time were measured from the sample surface. The described experiments integrate a novel analysis approach to the results from the DIC technique and propose a way of interpreting the outcomes regarding crack development in terms of velocity. While developing the methodology, the pre-processing of the data (UHSC images) was shown to enhance the DIC analysis and affect the further post-processing of the results. The presented methodology proposes a human-independent procedure of analysis that can help to differentiate the displacement of the crack along its time. Nevertheless, a visual analysis of the results was performed to complement the results and try to broaden the understanding of the crack development process. The DIC results indicated a nonconstant crack propagation velocity while the development patterns were interpreted to match previous literature. The experimental studies confirmed the radial propagation behavior surrounding the blasthole in the single borehole test, while the two borehole configurations show to influence the crack propagation direction and interconnection. This work describes small-scale experiments that provide meaningful insights in crack propagation and how the different blast design parameters can affect their development. The findings of this study could be useful as an input of a predictive tool to assess blast-induced crack initiation and development. / BeFo (Rock Engineering Research Foundation, Sweden) project number 427, “Experimental and Numerical modeling of blast-induced damage around rock tunnel using LS-DYNA”
310

Staple Crop Diversity and Risk Mitigation - Potatoes in Bolivia

Castelhano, Michael Joseph 18 November 2008 (has links) (PDF)
Rural areas of most developing nations are dependent on agriculture. In the most remote areas, sometimes referred to as the "less favored areas" (LFAs), the economic importance of agriculture is paramount. An important obstacle to development in these areas is that agriculture is at the mercy of nature, which may not be particularly friendly. These areas have remained remote due to natural shortcomings causing economic development to occur slower than more advantaged areas elsewhere. Cochabamba Department, in central Bolivia, is home to some of these LFAs. Most Cochabamban producers are located in the "high climatic risk" (CIP-WPA) Andean highlands. Farmers in LFAs surrounding Cochabamba city produce (among other things) potatoes for market and home consumption; the potato is the main source of food and income for most residents. Previous studies and anecdotal evidence have shown that Andean potato farmers may plant upwards of 10 varieties of potatoes on small amounts of land (Brush, 92). Because of the low rates of improved crop variety adoption in many LFA's, efforts are needed to understand farmer objectives and needs with respect to variety characteristics. The goal of this study is to determine how exposure to risk factors impacts potato planting decisions through demand for potato variety characteristics. The main source of data for this project is a survey of 145 farm households implemented during the last quarter of 2007 in 3 communities of Cochabamba. These data were used to estimate an econometric model that evaluated the role of household, regional and variety characteristics in farmer decision making. Decisions about planting each variety were modeled with a Tobit framework and estimated by the Heckman method (as suggested by Cameron and Trivedi), with the impact of individual variety characteristics restricted to be the same for each variety. Several hypotheses were confirmed such as the importance of yield, though many results were different than expected. Blight tolerance was found to be negatively correlated with selection, although most farmers report taking some kind of action to decrease damage from blight. Possible explanations for this negative correlation are discussed in this paper, and strategies for overcoming these obstacles are suggested. / Master of Science

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