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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.
51

Techno-economic analysis of an off-grid micro-hydrokinetic river system as a remote rural electrification option

Koko, Sandile Phillip January 2014 (has links)
Thesis (M. Tech. (Electrical Engineering )) - Central University of Technology, Free State, 2014 / Remote rural electrification via grid-extension is a challenging solution due to high connection costs and low electricity consumption rate. As a result, it is difficult to recover the initial investment costs. Therefore, electrification is made possible by means of the commonly used off-grid approaches such as solar, wind, diesel generator and conventional micro-hydro. However, owing to non-continuous availability of sunlight and wind, high cost of diesel fuel, and requirements for construction of diversion weirs, these off-grid approaches might not offer a cost-effective and reliable solution to low income rural residents. There are many rural communities throughout the world without access to grid electricity and with access to flowing water. An off-grid micro-hydrokinetic river (MHR) system is one of the promising technologies to be used in remote rural areas with flowing water. It can bring sustainable improvement to their quality of life due to its high energy density and minimal environmental impact. This technology is still in the development stage and there is a lack of application, especially in rural areas. Hence, this study investigates the current status of MHR technology in rural applications. To demonstrate the economic feasibility of an off-grid MHR system, a rural site with multiple energy sources within South Africa has been used. The economic benefit offered by this proposed system at the selected site is compared to the economic benefits offered by other commonly used standalone systems such a solar, wind and diesel generator (DG). This economic comparison has been performed by making use of a Hybrid Optimization Model for Electric Renewable (HOMER) simulation tool. Grid extension has also been used as a comparison method for obtaining an economical distance between grid lines and the remote rural site. The results highlighted the acceptable economic performance of the MHR system. Finally, most of the available modelling and simulation tools for mechanical and electrical systems are not equipped with hydrokinetic modules. Hence, an MHR system model has been developed in MATLAB/Simulink in order to study its dynamic performance as submitted to variable water resource. Its performance has then been compared to the performance of a wind system counterpart for generating the same amount of electrical power. This proved/verified that the proposed system can generate electricity markedly cheaper than a wind system even in areas with adequate wind resource within South Africa.
52

Techno-economic analysis of an off-grid micro-hydrokinetic river system as a remote rural electrification option

Koko, Sandile Phillip January 2014 (has links)
Thesis (M. Tech. (Electrical Engineering )) - Central University of Technology, Free State, 2014 / Remote rural electrification via grid-extension is a challenging solution due to high connection costs and low electricity consumption rate. As a result, it is difficult to recover the initial investment costs. Therefore, electrification is made possible by means of the commonly used off-grid approaches such as solar, wind, diesel generator and conventional micro-hydro. However, owing to non-continuous availability of sunlight and wind, high cost of diesel fuel, and requirements for construction of diversion weirs, these off-grid approaches might not offer a cost-effective and reliable solution to low income rural residents. There are many rural communities throughout the world without access to grid electricity and with access to flowing water. An off-grid micro-hydrokinetic river (MHR) system is one of the promising technologies to be used in remote rural areas with flowing water. It can bring sustainable improvement to their quality of life due to its high energy density and minimal environmental impact. This technology is still in the development stage and there is a lack of application, especially in rural areas. Hence, this study investigates the current status of MHR technology in rural applications. To demonstrate the economic feasibility of an off-grid MHR system, a rural site with multiple energy sources within South Africa has been used. The economic benefit offered by this proposed system at the selected site is compared to the economic benefits offered by other commonly used standalone systems such a solar, wind and diesel generator (DG). This economic comparison has been performed by making use of a Hybrid Optimization Model for Electric Renewable (HOMER) simulation tool. Grid extension has also been used as a comparison method for obtaining an economical distance between grid lines and the remote rural site. The results highlighted the acceptable economic performance of the MHR system. v Finally, most of the available modelling and simulation tools for mechanical and electrical systems are not equipped with hydrokinetic modules. Hence, an MHR system model has been developed in MATLAB/Simulink in order to study its dynamic performance as submitted to variable water resource. Its performance has then been compared to the performance of a wind system counterpart for generating the same amount of electrical power. This proved/verified that the proposed system can generate electricity markedly cheaper than a wind system even in areas with adequate wind resource within South Africa.
53

Implantation et hydraulique monastiques : le cas de Cluny / Monastic implantation and hydraulic : the case of Cluny

Rollier, Gilles 30 March 2010 (has links)
En 910, l’abbé Bernon et le duc d’Aquitaine, Guillaume le Pieux, implantent l’abbaye de Cluny, dans une vallée du Mâconnais, sur une terrasse alluviale formée à la confluence entre la Grosne et un de ses affluents. Cette situation offre des possibilités importantes d’utilisation des cours d’eau pour les divers besoins des moines. L’affluent, qui prendra dans le courant du Moyen Âge le nom évocateur de Médasson, est capté pour les fontaines du monastère et pour les réseaux d’assainissement où les latrines se trouvent mises en place. Les moulins, dont le moulin monastique, sont construits sur les bras dérivés de la Grosne.Par le choix d’un site placé en bordure de rivière, les fondateurs de Cluny pourraient avoir perpétué des traditions d’implantation qu’il est possible de percevoir dès la période carolingienne et qui seront par la suite suivies par les cisterciens.Dans l’environnement de ce site d’interfluve, les moines de Cluny vont progressivement développer un réseau hydraulique dont la complexité est liée à la fois aux besoins d’une communauté monastique importante, aux modifications successives des constructions monastiques et au respect des limites des territoires immunitaires de l’abbaye. / In 910, abbot Bernon and duke of Aquitaine, Guillaume le Pieux, implanted the abbey of Cluny, in a valley of Mâconnais, on an alluvial terrace formed in the confluence between Grosne and one of his tributaries. This situation offers important possibilities of use of streams for the diverse needs of the monks. The tributary, which will take in the course of the Middle Ages the suggestive name of Médasson, is used for the fountains of the monastery and for the sewer systems where latrines are installed. The mills, which the monastic mill, are built on arms derived of Grosne.By the choice of a site placed in border of river, the founders of Cluny could have perpetuated the traditions of implantation which we can to perceive from the Carolingian period and which will be followed by the Cistercians.In the environment of this site of confluence, the monks of Cluny are gradually going to develop a hydraulic network the complexity of which is bound at the same time to the needs of an important monastic community, to the successive modifications of the Monastic constructions and to the respect for the limits of the immunity territories of the abbey.
54

Návrh pohyblivého jezu na řece Želivce / Design of gated weir on the Želivka river

Staněk, Tomáš Unknown Date (has links)
The purpose of the diploma thesis „Design of a movable weir on the Želivka river" is a design of the reconstruction of a fixed weir in Soutice village on the river Želivka at km 1,639. The first part of the thesis deals with the localization of the area of interest and a description of all documents needed for the weir design. The first part also includes a short search of the considered structures, the findings of which are further applied in the design of a movable weir structure. Furthermore, the work continues by determining the design flow and selecting a suitable structure of the fixed weir substructure and movable closure, which is fitted to the substructure. Based on the selected types of structures, hydrotechnical calculations are performed, which also include a partial assessment of the weir stability. The thesis ends with a technical description of the proposed objects and a final evaluation of the determined achievements of the work. Part of the study is a drawing part documenting designed objects.
55

Podnikatelský záměr v oblasti obnovitelných zdrojů energie / Business Project in the Area of Renewable Resources of Energy

Kerndl, Michal January 2009 (has links)
The aim of my thesis, which is called „Business project in the area of renewable energy resources“, is to analyze business opportunities in the area of renewable energy resources, which have been highly actual and discussed recently, whether in term of benefit for environment or in connection with international problem of shortness in energy resources. Result of this thesis is, on the basis of the analysis, to define recommendations in the form of optimal proposal for realization. The thesis is engaged in description of current state in the area of the renewable energy resources, their utilization in practice and consequential proposals for realization including project financial plan. The thesis is also engaged in possibilities of state budget and EU grants use.
56

Analýza nesrovnalostí MVE Ostravice / Contradictions analysis of small water power Ostravice.

Kupčík, Roman January 2009 (has links)
The main subject of the diploma thesis „Contradiction analysis of small water power Ostravice“ is solution of reduced output of small water power plant on the river Ostravice near the town Vratimov. Power plant equippment is axial flow Kaplans turbine RA – 3,5 – 0 1000 with runner diametr 1000 mm. Low output is caused by draft tube. New draft tube is designed in this masters thesis. For hydraulic layout was used CFD software Fluent. The aim of this work is finding of optimal shape which leads to increasing of power from current 30 kW to projected 55 kW.
57

Měření napjatosti ve spirále vodní turbíny pomocí tenzometrů / Measurements of the stress in the turbine spiral casing using the strain gauges

Dokoupil, Pavel January 2014 (has links)
The Master‘s thesis is focused on measuring of the stress in the spiral case of water turbine using the strain gauges measurement. It contains the theoretical and the practical part. The theoretical part includes a description of theoretical background (basic mechanics, measurement and evaluation, strain gauges, pressure measurement, uncertainty of measurement). One of the chapters describes Water Power Plant Lipno nad Vltavou (history of power plant, issues and the history of measurement). The practical part contains a theoretical calculation of measurement uncertainty and measuring of stress on spiral case Francis turbine at Water Power Plant Lipno I (Unit TG2). Measurement was made before and after overhaul. There are described technical data of spiral cases, description of measurement, results of measuring of strain and stress including comparison with the pressure in spiral case and calculation of uncertainties of measurement.
58

A proteção do meio ambiente sobre a perspectiva das fontes alternativas de energia

Riquelme, Daniela Maria 03 December 2008 (has links)
Made available in DSpace on 2016-04-26T20:28:20Z (GMT). No. of bitstreams: 1 Daniela Maria Riquelme.pdf: 3664410 bytes, checksum: f671a6b4378f17885fbd022301cd8f41 (MD5) Previous issue date: 2008-12-03 / This present work has the intention to present the environment as a diffuse good belonging to an undetermined plurality of subjects, which are undividable in relation to its holders and their protection is responsibility of Public Power and also the collectivity. Therefore, when we deal with sustainable energy consumption, which is in the present case the alternative energy sources, we are preserving the current environment for us and for the future generations, respecting ourselves as citizens and the legal norms / A presente dissertação pretende demonstrar que o meio ambiente é um bem difuso pertencente a uma pluralidade indeterminada de sujeitos, indivisíveis em relação aos seus titulares e cuja defesa incumbe tanto ao Poder Público quanto a coletividade. Desta forma, quando nos preocupamos com o consumo consciente da energia, no caso presente das fontes alternativas de energia, estamos cuidando do meio em que vivemos, tanto para nós quanto para as futuras gerações respeitando, assim, nós mesmos como cidadãos e, as normas legais
59

The use of Water Point Mapping (WPM) as a tool to assess improved water resources in rural communities

Taonameso, Solomon 05 1900 (has links)
MSc (Microbiology) / Department of Microbiology / See the attached abstract below
60

Mind the gap : En fenomenologisk analys av möjligheter och hinder för entreprenöriell förnybar elproduktion i Stockholms skärgård

Christensson, Ellinor, Svedberg, Simon January 2023 (has links)
This study uses Friederike Welter’s (2011; Welter, Baker & Wirsching 2019) concept of contextualizing entrepreneurship by analyzing discrete and omnibus variables within contexts to distinguish underlaying factors that hinder or create opportunities for increased entrepreneurship within renewable energy sources in Stockholm’s archipelago. The study is based on semi-structured interviews from stakeholders who work with renewable energy in the area both within the private and public sector. The sample number was selected by purposive sampling and consisted of 7 respondents. The qualitative analysis resulted in five phenomenologically derived themes. The results shine a light on overarching obstacles that hinder the establishment of renewable energy production in Stockholm’s archipelago such as overcomplicated institutional processes as well as overcomplicated institutional permit processes, resistance to change and lack of responsibility, regulatory gaps and regulatory overload, minimal access to the energy market and that the infrastructure of Stockholm’s electrical grid is underdeveloped. / Studien använder Friederike Welters (2011; Welter, Baker & Wirsching 2019) koncept om att kontextualisera entreprenörskap genom att analysera diskreta- samt omnibusvariabler inom kontexter för att urskilja underliggande faktorer som hindrar eller skapar möjligheter för framgångsrikt entreprenörskap inom förnybar energi i Stockholms skärgård. Studiens empiri baseras på semistrukturerade intervjuer av aktörer, både inom privat och offentlig sektor, som arbetar med förnybar energi i området. Respondenterna valdes ut genom strategiskt urval och bestod av sju respondenter. Studien antar en kvalitativ metod och resulterade i fem fenomenologiskt utvalda teman. Studiens resultat belyser förbättringsmöjligheter genom att urskilja övergripande barriärer som hindrar den entreprenöriella etableringen av förnybar energi i Stockholms skärgård såsom regulatoriska glapp, bristande definition och regelverk för Sveriges skärgård, motstånd mot förändring, överkomplicerade institutionella tillståndsprocesser och regulatorisk överbelastning, brist på tillgång till energimarknaden samt en underutvecklad infrastruktur av Stockholms elnätverk.

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