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Vågen, Rolf Åge. "Design of tension leg anchor systems for floating windmills." Thesis, Norges teknisk-naturvitenskapelige universitet, Institutt for marin teknikk, 2011. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-15510.
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Renewable energy is likely to be of great importance in decades to come due to increased energy consumption. Kinetic energy from wind is expected to cover a part of this need, and wind farms are so far built onshore or at shallow water. On the other hand wind turbines are not always wanted close to land due to both the visual aspects and bird life. An alternative may therefore be to place wind turbines offshore. However, large water depths are causing problems for existing bottom fixed structures and floating wind turbines may therefore be a solution. In this thesis feasibility of tension leg anchor systems for floating wind turbines is investigated. A literature study including tension leg principles, relevant load parameters and methods for calculating motions on tension leg structures are looked into. Preliminary calculations of motion based on a one degree of freedom model are coded and executed in Matlab. Finally, a model in scale 1:100 has been built and further exposed to regular waves in a laboratory test. Numerical and experimental results are investigated and compared for different wave parameters in order to reveal potential weaknesses of the concept. Numerical and experimental results coincide quite well for structure motion in the wave direction, and in most cases the structure get small motion amplitudes which generate negligible vertical motions in form of set down. The overturning moment calculations also coincide well, and show that there are limitations in the mooring feasibility when exposed to large waves. The pretension is proven to be a very important parameter for the concept. Measurement of tendon forces from laboratory test show that the model is loaded differently and in larger order of magnitude than expected. For the scaled model a simplified tendon attachment arrangement in form of a steel plate is used. The strange force distribution may therefore represent loading on this plate. The results however show that tension leg anchoring can be a relevant alternative type of anchor system for floating wind turbines if sufficient system pretension is obtained. In addition, if also a reasonable magnitude and distribution of mass are obtained, the structure is expected to handle quite large waves. The design presented in this thesis is far from optimized. For further work it is therefore advised to model the structure in software where structural analysis can be executed in order to decide upon an optimized structural weight, seeing this as an important parameter.
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Roth, Neal Joseph. "A prototype design and performance of the Savonius rotor based irrigation system." Thesis, University of British Columbia, 1985. http://hdl.handle.net/2429/25106.
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Important stages in the development of a wind energy operated irrigation system, which is simple in design and easy to maintain, are described from model tests in wind tunnels through to a prototype prepared for field tests. The attention is focussed on gross features of the protoype including the blade geometry and aspect ratio; mast, sleeve and bearing assemblies; braking system and a load matching concept. Described towards the end are the field test arrangements of the prototype and associated instrumentation. Even according to the most conservative estimate, the prototype tests suggest that the windmill should be able to deliver around 3000 liters of water per day (eight hours of wind) to a head of 5 m in a 24 km/h wind.Applied Science, Faculty of
Mechanical Engineering, Department of
Graduate
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Fernando, Mahamarakkalage Saman Udaya Kumar. "On the performance and wake aerodynamics of the Savonius wind turbine." Thesis, University of British Columbia, 1987. http://hdl.handle.net/2429/27299.
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The objective of the thesis is to establish methodology for development of a wind turbine, simple in design and easy to maintain, for possible application in developing countries. To that end the Savonius configuration is analyzed in detail both experimentally and analytically to lay a sound foundation for its performance evaluation. Following a brief review of relevant significant contributions in the field (Chapter I), an extensive wind tunnel test-program using scale models is described which assesses the relative influence of system parameters such as blade geometry, gap-size, overlap, aspect ratio, Reynolds number, blockage, etc., on the rotor output. The parametric study leads to an optimum configuration with an increase in efficiency by around 100% compared to the reported efficiency of ≈ 12 — 15%. Of particular interest is the blockage correction procedure which is vital for application of the wind tunnel results to a prototype design, and facilitates comparison of data obtained by investigators using different models and test facilities.
With the design and performance results in hand, Chapters III — VI focus attention on analytical approaches to complement the test procedure. Using the concept of a central vortex, substantiated by a flow visualization study, Chapter III develops a semi-empirical approach to predict the rotor performance using measured stationary blade pressure data. The objective here is to provide a simple yet reliable design tool which can replace dynamical testing with a significant saving in time, effort, and cost. The simple approach promises to be quite effective in predicting the rotor performance, even in the presence of blockage, and should prove useful at least in the preliminary design stages.
Chapter IV describes in detail a relatively more sophisticated and rigorous Boundary Element Approach using the Discrete Vortex Model. The method attempts to represent the complex unsteady flow field with separating shear layers in a realistic fashion consistent with the available computational tools. Important steps in the numerical analysis of this challenging problem are discussed at some length in Chapter V and a performance evaluation algorithm established. Of considerable importance is the effect of computational parameters such as number of elements representing the rotor blade, time-step size, location of the nascent vortices, etc., on the accuracy of results and the associated cost. Results obtained using the Discrete Vortex Model are presented and discussed in Chapter VI, for both stationary as well as rotating Savonius configurations. A detailed parametric study provides fundamental information concerning the starting and dynamic torque time histories, power coefficient, evolution of the wake, Strouhal number, etc. A comparison with the flow visualization and wind tunnel test data (Chapter II) shows remarkable correlation suggesting considerable promise for the approach. The thesis ends with concluding remarks and a few suggestions concerning possible
future research in the area.Applied Science, Faculty of
Mechanical Engineering, Department of
Graduate
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Assam, Ukpong D. "Storage model for multibladed water pumping windmills with piston pumps." Thesis, University of Ottawa (Canada), 1986. http://hdl.handle.net/10393/4730.
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Sachithanathamoorthy, Kumaravalavan. "DESIGN AND ANALYSIS OF TENSION LEG ANCHOR SYSTEMS FOR FLOATING WINDMILLS." Thesis, Norges teknisk-naturvitenskapelige universitet, Institutt for marin teknikk, 2012. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-18613.
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Increasing demand for clean and effective energy production turns interests of the world on floating offshore wind technology. To establish floating wind farms, a wind turbine have to be mound on a floating structure. The floating structure has to be carefully design according to sea environmental condition and kept in precise position. Different types of floating structure and stationkeeping systems have been proposed for floating wind turbines. This project deals with design a spar floater with tension leg mooring system, where the vertical fairlead position located between center of buoyancy and center of gravity. In this project a details study about floater design and tension leg concept was presented. Further, a model was established in computer program RIFLEX and static and dynamic analysis was carried out for two different environmental conditions, one for an operation condition to understand the model behaviour in normal sea state. The second one was for extreme condition to estimate the extreme tether forces and find out slacking possibility.
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Phillips, Russell Leslie. "Development of a reciprocating aerofoil wind energy harvester." Thesis, Nelson Mandela Metropolitan University, 2008. http://hdl.handle.net/10948/899.
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Cross flow wind turbines are not unique. The performance of Savonius and Darrieus turbines is well documented. Both share the advantage of being able to accept fluid flow from any direction. The Savonius is drag based and hence has poor power output while the Darrieus is lift based. Due to the fact that the Darrieus has fixed blades the fluid flow through the rotor does not result in optimal lift being generated at all points in the rotation circle. A drawback of the Darrieus system is that it has to operate at a high tip-to wind-speed ratio to obtain reasonable performance with the fixed blades. Deviation from a small optimal range of tip speed ratios results in poor performance. The Darrieus also has poor starting torque. The research conducted in this project focused on overcoming the shortcomings of other turbines and developing an effective cross flow turbine capable of good performance. A number of different concepts were experimented with, however all were based on a symmetrical aerofoil presented to the actual relative airflow at an angle that would produce the highest lift force at all times. The lift force was then utilized to generate movement and to do work on an electrical generator. All concepts contemplated were researched to ascertain their appropriateness for the intended application. During development of the final experimental platform and after lodging of a provisional patent (RSA 2007/00927) it was ascertained that the design shared some similarities with an American patent 5503525 dated 28/4/1994. This patent employed complex electronic sensing and control equipment for control of blade angle. This was thought to be overly complex and costly, particularly for small scale wind energy generation applications and a simpler mechanical solution was sought in the design of the final experimental platform used in this project. The design of the mechanical control system was refined in an attempt to make it simpler, more durable and employ the least number of moving parts. Literature studies and patent searches conducted, suggested that the mechanical control system as developed for the final experimental platform was unique. The enormous variation in the power available from the wind at the different wind speeds likely to be encountered by the device necessitated some means of control. In high wind conditions control of the amount of wind power into the device was deemed to be the preferable means of control. A number of different concepts to achieve this were devised and tested. The final concept employed limited the tail angle deflection and hence the lift produced by the aerofoils. This resulted in a seamless “throttle” control allowing the device to be used in any wind strength by adjusting the control to a position that resulted in the device receiving a suitable amount of power from the wind. The outcome of performance tests conducted indicated that the device has the potential to be developed into a viable wind turbine for both small and large scale applications. The ability to control the power input from the wind to the machine from zero to a maximum is considered to be one of the most beneficial outcomes of this project and together with the quiet operation and low speed, are considered the main advantages of the device over existing wind turbine designs. The possibilities of using the device to compress air for energy storage are exciting avenues that warrant further research.
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Decker, Craig Adams. "Tilters with windmills--the coevolution of the appropriate technology movement in America." Thesis, Massachusetts Institute of Technology, 1988. http://hdl.handle.net/1721.1/36418.
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Barry, Christopher M. "Tilting at windmills the suspension of disbelief in three tone poems of Richard Strauss /." Cincinnati, Ohio : University of Cincinnati, 2005. http://www.ohiolink.edu/etd/view.cgi?acc%5Fnum=ucin1122672809.
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Thesis (Master of Music)--University of Cincinnati 2005.Title from electronic thesis title page (viewed Mar. 3, 2006). Includes abstract. Keywords: suspension of disbelief; Strauss, Richard; music, philosophy of. Includes bibliographical references.
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BARRY, CHRISTOPHER M. "TILTING AT WINDMILLS: THE SUSPENSION OF DISBELIEF IN THREE TONE POEMS OF RICHARD STRAUSS." University of Cincinnati / OhioLINK, 2005. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1122672809.
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Burris, Matthew. "Tilting at windmills? The counterposing policy interests driving the commercial satellite export control reform debate." Thesis, McGill University, 2010. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=95254.
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United States strategic export controlswhich treat commercial satellite technologies, related technical data, and defense services as munitions subject to the strictest export control criteriahave been under fire for decades. Critics argue that in attempting to bolster national security by limiting the transfer of space technologies to adversaries and potential adversaries, the U.S. has unintentionally and paradoxically harmed national security by undermining the space industrial base, the academic and research institutions that feed and grow that base, and the international partnerships that drive sci entific and technological advancement. There are few, if any, unequivocal supporters of the U.S. export control regime as it stands. As a result, both regulatory and statutory reform initiatives are afoot. Yet this begs the question: if the problems are and have been so apparent, why have the regulations and concomitant organic legislation not been subject to reform before now? This thesis will deconstruct the current discourse (keeping in mind its historical underpinnings) and challenge the orthodoxies of the export control reform debate in order to determine, to the extent possible, the merits of individual arguments and claims.La stratégie des Etats-Unis quant au contrôle des exportations, qui inclut les technologies des satellites commerciaux, leur données techniques, ainsi que les services de défense en tant qu'armes sujettes à des critères plus stricts de contrôle des exportations, essuie les critiques depuis des années. Ses détracteurs avancent qu'en essayant de renforcer la sécurité nationale par des restrictions au transfert de technologies spatiales à ses ennemis et adversaires potentiels, les Etats-Unis ont, malgré eux et paradoxalement, nui à la sécurité nationale en négligeant les bases de l'industrie spatiale, les centres de recherche et universitaires qui nourrissent et développent celles-ci, ainsi que les partenariats internationaux qui conduisent au progrès scientifique et technologique. Il y a peu, si ce n'est, aucun partisan inconditionnel au régime de contrôle des exportations américain tel qu'il est à l'heure actuelle. Par conséquent, des initiatives de réformes des lois et règlements se préparent. Cela soulève, cependant, la question suivante: si des problèmes sont si évidents, pourquoi les règlements et lois correspondantes n'ont-ils pas été sujets à une réforme plus tôt? La présente thèse a pour but de déconstruire le discours usuel (tout en tenant compte de ses fondements historiques) et remet en question la doctrine traditionnelle sur la réforme, dans le but de déterminer, autant que faire ce peut, le bien-fondé des raisons et revendications individuelles, en démêlant, notamment, le vrai du faux.
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Leveille, John J. "Tilting against windmills : a sociological study of the psychoanalytic dominance of American psychiatry, 1930-1980 /." Diss., Connect to a 24 p. preview or request complete full text in PDF format. Access restricted to UC IP addresses, 2000. http://wwwlib.umi.com/cr/ucsd/fullcit?p9975046.
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Bidaud, Pierre. "Analysis of the cyclic behavior of an adhesive in an assembly for offshore windmills applications." Thesis, Brest, 2014. http://www.theses.fr/2014BRES0119/document.
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L’une des principales exigences d’utilisation d’un adhésif est son aptitude à conserver sa capacité à supporter des efforts, appliqués de manière répétée, tout au long de sa vie en service. Toutefois, on dénombre peu d’études sur le comportement en fatigue des assemblages collés. De plus, ces études concernent majoritairement la propagation de fissures et non l'amorçage. Le comportement en fatigue d’assemblages collés est généralement caractérisé grâce à des essais simple-recouvrement auxquels sont associés des états de contrainte complexes présentant de fortes concentrations de contrainte. Le but de ce travail est de développer un outil prédictif du comportement cyclique d’un adhésif dans un assemblage soumis à un chargement de fatigue, en utilisant des essais basés sur l’utilisation d’un montage Arcan modifié. Ce type de montage utilise des éprouvettes générant un état de contrainte avec peu d’effets de bord et un maximum au centre du joint de colle. Une base expérimentale constituée d'essais monotones, cycliques et de fluage pour différents modes de chargement sont présentés. Les résultats expérimentaux concernant un adhésif bi-composant polyuréthane SikaForce®-7817 L60MR permettent de caractériser un comportement reproductible. Ces résultats soulignent une évolution non-linéaire des déformations et fortement dépendante du type de chargement. Ce comportement peut être décrit par l’utilisation d’un modèle visco-élastique-visco-plastique. Implanté dans un code de calcul par éléments finis, ce modèle a permis d’analyser l’influence des phénomènes visqueux. Afin de limiter les temps d'essais, une identification inverse des paramètres a été menée à partir d'une campagne d'essais Arcan en fluage/recouvrement. Les simulations par éléments finis ont permis de décrire le comportement cyclique de structures collées et en utilisant un critère de rupture pertinent, d'effectuer un calcul de durée de vie à l'amorçage d'une fissure. Ce travail a été appliqué à l’étude du comportement en fatigue d'assemblages collés pour applications éoliennes offshores. Aussi, à partir de la stratégie développée, des estimations de la durée de vie de structures composites collés ainsi que d’un cas d’application représentatif ont été réaliséesEstimating capacities of adhesives to endure repetitive loadings is an essential point to perform fatigue assessments. Nevertheless, few studies have been performed on the cyclic behaviour of adhesively bonded structures. Moreover, fatigue crack initiation is less studied for adhesives than the fatigue crack propagation. Fatigue behaviour is mainly analysed using lap-shear type specimens, which are associated with complex stress states and stress concentrations. The aim of this work is to develop a predictive tool describing the cyclic behaviour of an adhesive in an assembly under fatigue loading using an experimental approach based on modified Arcan tests. Such a device is associated with low edge effects and a maximum stress state in the centre of the adhesive. Accurate experimental results under monotonic, creep and cyclic loading are presented for several load amplitudes, mean loads and loading rates. For a two-component polyurethane SikaForce®-7817 L60 MR adhesive, experimental results led to reproducible behaviour. These results underline that the evolutions of the non linear strains strongly depend on the loading type. This behaviour is well described using a visco-elastic-visco-plastic model with non-linear viscous parameters. This model, implemented in 3D finite element simulations, allows analysing the influence of viscosity. In order to limit the experimental test time the inverse identification of the model parameters is performed from modified Arcan creep-relaxation tests. The finite element simulations of bonded structures allowing an efficient description of the cyclic behaviour and using an adequate failure criterion based on the viscous strains evolutions, a validation on fatigue life predictions is performed. This work is dedicated to the study of fatigue of bonded structures in offshore windmills applications. From this strategy a fatigue life estimation of composite structures tests and on an application test is proposed
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Brostrand, H. L. "Evaluating the Tilting at Windmills curriculum's effectiveness in changing attitudes toward people with disabilities in the workplace /." Available to subscribers only, 2006. http://proquest.umi.com/pqdweb?did=1216741291&sid=15&Fmt=2&clientId=1509&RQT=309&VName=PQD.
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Macey, Maxwell N. "Tilting at Windmills: The Treatment of China as a Non-Market Economy Under United States Trade Law." Scholarship @ Claremont, 2017. http://scholarship.claremont.edu/cmc_theses/1484.
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Under World Trade Organization (“WTO”) rules, the United States and other developed countries are specifically permitted to treat the People’s Republic of China (the “PRC” or “China”) as a Non-Market Economy (“NME”). Under U.S. trade laws, China’s designation as an NME allow imposition of tariffs to protect U.S. industries from “dumping” and to offset subsidies provided by foreign countries to their producers. However, on December 11, 2016, 15 years after China’s accession to the WTO, the U.S.’ legal right to automatically treat China as an NME expires under WTO law. The U.S. government has created NME methodologies under U.S. trade laws that impose often staggering duties on imports from China in a wide range of industries—duties that often have little relationship to economic reality. In effect, the U.S. is engaged in a guerrilla trade war with China, with NME status as the primary weapon. There is immense political resistance to ending the automatic NME treatment of China. For example, even Hillary Clinton, who was less openly confrontational towards China than Donald Trump, stated in her recent Presidential campaign, “Right now, Washington is considering Beijing’s request for ‘market economy’ status…if they get market economy status, it would defang our anti-dumping laws and let cheap products flood into our markets. So we should reply with only one word: No.”[i] This intense political anger is fueled by the displacements that China’s rapid rise and exports to the U.S. have engendered.[ii]
Trade policy with respect to China needs to be considered in light of the critical importance of the relationship to both countries. China has become the United States’ largest single trading partner. Although the size of the trade deficit with China clearly accounts for the current heated political rhetoric about unfair trade with China, the fact is that China is by far the U.S.’ largest export trade partner (excluding our NAFTA neighbors Canada and Mexico), with exports almost twice the size of the next nearest country, Japan. This alone indicates it is in the United States’ interest to have a rational trading relationship with China.
The U.S. should end the treatment of China as an NME. The policy is both ineffective and irrational. The capital markets do not consider the policy effective: recent relevant case studies show that protected U.S. companies often do not experience the intended benefit of trade law protection—a healthier business—based on analysis of their stock price performance beyond short term effects. After controlling for overall market fluctuations, companies will, at most, experience a short-term jump in their stock price. In the examples studied below, the stock price typically returns to pre-trade law protection figures within weeks. Such results imply two important points: 1) the company’s long-term fundamentals, which typically determine long-term stock performance (e.g. growth rate, cash flows, and margins), are unchanged by trade law protection; and 2) investors do not believe that these policies have a significant, long-term positive impact on U.S. companies.
Regular “market economy” U.S. trade law provides real and sufficient remedies to address subsidies and dumping. Not only does the treatment of China as an NME exacerbate tensions with China[i], it imposes both unpredictable and excessive costs on U.S. consumers who purchase Chinese goods and makes U.S. businesses that use Chinese products to produce final goods less competitive with foreign competitors not facing such artificial costs[ii].
[i] Hornby, Lucy and Shawn Donnan, “China Fights for Market Economy Status”, May 9, 2016, Financial Times,
https://www.ft.com/content/572f435e-0784-11e6-9b51-0fb5e65703ce.
[ii] Mankiw, Gregory N. and Phillip L. Swagel, “Antidumping: The Third Rail of Trade Policy,” Foreign Affairs,
Vol. 84, No. 4 (Jul. - Aug., 2005), pp. 107-119.
[i] Clinton, Hillary, “Commentary: If Elected President, I’ll level the Playing Field on Global Trade,” Portland Herald Press, February 23, 2016, http://www.pressherald.com/2016/02/23/commentary-if-elected-president-ill-level-the-playing-field-on-global-trade-clinton-says/
[ii] Autor, David H., David Dorn and Gordon H. Hanson, “The China Shock: Learning from Labor Market Adjustment to
Large Changes in Trade,” NBER Working Paper Series, Working Paper 21906, National Bureau of Economic Research, January 2016, http://economics.mit.edu/files/11675.
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Simões, Vera Lúcia David. "Construir através da memória." Master's thesis, Universidade de Lisboa, Faculdade de Arquitetura, 2020. http://hdl.handle.net/10400.5/21779.
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Dissertação de Mestrado Integrado com a especialização em ArquiteturaCom o decorrer do tempo, o Vale de Alcântara tem vindo a sofrer um processo de artificialização do seu sistema natural perdendo a sua qualidade paisagística e ambiental, fundamentais para a cidade de Lisboa. Alcântara é hoje uma zona densamente infraestruturada, com o encanamento da ribeira, a construção de autoestradas, caminhos de ferro e de pontes. Esta carga infraestrutural reflete-se na sua malha urbana originando bolsas isoladas de habitação, vazios urbanos e grandes áreas industriais abandonadas, transformando profundamente não só a paisagem, mas sobre tudo a relação dos seus habitantes com o vale. A fragmentação do espaço urbano e a descontinuidade natural presente hoje em dia, deixou para trás a imagem de uma paisagem bucólica e verdejante que outrora aqui existiu. A inversão deste processo passa pelo uso da memória como essência conceptual de projeto, desenvolvendo uma proposta de intervenção contemporânea que valorize a utilização sustentável dos recursos e características naturais existentes: a ribeira, os solos férteis, as colinas e a exposição solar. Assim, a proposta deste documento final de mestrado passa por repensar este território, devolvendo a Alcântara um vale estruturante, renaturalizado que coexiste em harmonia com o sistema natural esquecido, numa lógica de eixo natural requalificador, que integre e permita atividades sociais, cultuais e económicas. Onde, para além de se integrar na estrutura da cidade de Lisboa, se traduza num compromisso sustentável e ecológico de regeneração urbana.
ABSTRACT: Over time, the Vale de Alcântara has been suffering a process of artificialization of its natural system losing its landscape and environmental quality, essential for the city of Lisbon. Today Alcântara is a densely infrastructured area, with the plumbing of the river, the construction of highways, railways and bridges. This infrastructure load is reflected in its urban network, originating isolated housing pockets, urban voids and large abandoned industrial areas, profoundly transforming not only the landscape, but above all the relationship of its inhabitants with the valley. The fragmentation of the urban space and the natural discontinuity present today, left behind the image of a bucolic and green landscape that once existed here. The inversion of this process involves the use of memory as the conceptual essence of the project, developing a proposal for contemporary intervention that values the sustainable use of existing natural resources and characteristics: the riverside, fertile soils, hills and sun exposure. Thus, the proposal from this final master’s document goes through rethink this territory, giving Alcântara a structuring valley, renaturalized that coexists in harmony with the forgotten natural system, in a logic of requalifying natural axis, that integrates and allows social, cultural and economic activities. Where, in addition to being integrated into the structure of the city of Lisbon, it translates into a sustainable and ecological commitment to urban regeneration.
N/A
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Gutierrez, Zachary. "Multi-disciplinary capstone assessment project." Laramie, Wyo. : University of Wyoming, 2008. http://proquest.umi.com/pqdweb?did=1864813071&sid=1&Fmt=2&clientId=18949&RQT=309&VName=PQD.
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Sawatzky, Tamara A. "Material culture the Dutch windmill as an icon of Russian Mennonite heritage /." Online full text .pdf document, available to Fuller patrons only, 2002. http://www.tren.com.
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Fürst, Felix Verfasser], and Jörn [Akademischer Betreuer] [Wilms. "Galactic Windmills : Spectroscopical and Timing studies of three X-ray binaries = Galaktische Windmühlen / Felix Fürst. Betreuer: Jörn Wilms." Erlangen : Universitätsbibliothek der Universität Erlangen-Nürnberg, 2012. http://d-nb.info/1019433698/34.
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Pettersson, Maria. "Renewable energy and the function of law : a comparative study of legal rules related to the planning, location and installation of windmills." Doctoral thesis, Luleå tekniska universitet, Samhällsvetenskap, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-18758.
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Swedish energy policy relies heavily on the promotion of renewable energy, in particu-lar wind power. Notwithstanding a substantial political and economic support for this development, the installed capacity of wind power in Sweden remains fairly small both in relation to the corresponding development in other countries and in absolute num-bers. The starting point for this study is that the implementation of a planning policy, such as the Swedish development goal for wind power, is partly dependent on the re- quirements of the law. In other words, in the face of supposedly strong economic incen-tives to promote wind power, barriers to the implementation might be found embedded in the institutional system. The purpose of this study is thus, primarily, to describe and analyse the function of Swedish law with reference to the implementation of renewable energy policy objectives, with focus on the development of wind power. This involves legal rules related to planning, location and operation of windmills. The legal system is evaluated in respect of its capacity to facilitate or impede the development of wind power. Secondly, the study includes a comparative analysis of the corresponding legal functions in Denmark, Norway and England. The result of the analysis of Swedish law indicates that the legal system governing the implementation process encompasses bar- riers to the development of wind power. The main obstacles are found in the system for physical planning and the concession system, although quite a few hindering individual provisions have also been disclosed. The lack of sufficient control functions together with an extensive municipal power creates an unpredictable and ineffective planning system that basically lacks confidence for an efficient implementation of wind power. The installation of windmills may further require as many as five different types of permits, which risks to seriously hamper the development due to lengthy processes and appeals. Among the individual rules, the location requirement in the Swedish Environ-mental Code strikes as notably hindering; the requirement to objectively assess alterna-tive sites has in several cases obstructed the installation of windmills. Overall, the im- plementation deficits are considerable. The examination of the corresponding legal functions in Denmark, Norway and the United Kingdom presents some very important differences with respect to planning control and permit requirements, as well as regard-ing substantial provisions. Generally, it looks as if there is a correlation between the level of overarching control over the physical planning on the one hand, and the poten-tial to successfully implement renewable energy policy objectives on the other. Time-limits for permit procedures, legal standards for emissions, explicit rules for the balanc-ing of opposite interests and so forth, are other interesting features that may be em-ployed in Sweden. A realization of the Swedish wind power planning goal will thus presumably require changes of the law. The most important issue is perhaps to reduce the implementation deficits by improving the legal framework governing the planning and installation processes. A few of the discussed factors emerge as crucial in this re-spect and that is roughly: to remove the general permit requirement, and thus leave the entire trial to the planning system; and to breach the municipal planning monopoly.Godkänd; 2008; 20081124 (ysko)
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Pettersson, Maria. "Renewable energy development and the function of law : a comparative study of legal rules related to the planning, installation and operation of windmills /." Luleå : Luleå University of Technology, 2008. http://epubl.ltu.se/1402-1544/2008/65/LTU-DT-0865-SE.pdf.
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Hameedi, Ayoub. "Addressing the Electricity Shortfall in Pakistan through Renewable resources." Thesis, Uppsala universitet, Institutionen för geovetenskaper, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-188697.
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This report focuses on addressing the electricity shortfall in Pakistan with the help of renewable resources. At present, the country is facing a shortfall of almost 7,000 megawatts (MW) which is affecting every walk of life and causing almost 1.5 to 2% GDP loss on annual basis. Previous research done on this subject reveals that electricity demand has always remained high then the total generation capacity of Pakistan. Similarly, it has been pointed out that the country is not taking maximum benefit from its available hydro, solar and wind resources. This leads us to the basic purpose of this research which is to have an exploratory understanding of the strategies adopted by India, China, Brazil and Spain for electricity generation in a green fashion and how can these strategies be implemented in Pakistan. Case study has been adopted as methodology for this purpose. This research work also discusses the factors contributing in the lack of promotion of renewable energy resources in Pakistan and provide detailed analyses of positive changes these projects can bring in lives of masses in Pakistan. The sustainable management of surface water resource in the country has been discussed in particular as the country faced worst floods in its history during years 2010 & 2011. It will result in enhancing the surface water storage ability of Pakistan which will significantly reduce our dependence on underground water reserves and will directly increase our electricity generation capacity through hydro dams. Similarly, sustainable forest management has been discussed at length as it will not only ensure environmental sustainability but will also result in increase availability of biomass. Not to mention the fact that wood biomass is much cheaper then conventional source of electricity generation provided it is obtained through sustainable forest management. Finally, if all the green strategies discussed in this research work will be implemented, it will increase the overall electricity generation capacity of Pakistan up to 9% respectively.
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Silva, Lara Filipa Raposo da. "A reabilitação do património dos moinhos de vento do oeste: uma proposta integrada para a sustentabilidade dos moinhos do Casal Nordeste." Master's thesis, Universidade de Lisboa. Faculdade de Arquitetura, 2014. http://hdl.handle.net/10400.5/7906.
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Dissertação para obtenção do grau de Mestre em Arquitetura, apresentada na Universidade de Lisboa - Faculdade de Arquitetura.A dissertação tem como título: «A Reabilitação do Património dos Moinhos de Vento do Oeste: uma proposta integrada para a sustentabilidade dos moinhos do Casal Nordeste». A parte teórica da dissertação privilegiou dois eixos essenciais: considerações gerais acerca da temática molinológica, onde se contextualiza histórica e culturalmente a moagem em Portugal, focando a importância social e económica do moleiro, e também, fazendo referência às características específicas dos moinhos do Oeste, aos seus engenhos e o modo de funcionamento; considerações acerca da problemática associada às intervenções em moinhos, referindo tanto as soluções de salvaguarda como as situações de intervenções desadequadas ou descaracterizadoras. A parte prática, isto é, a intervenção propriamente dita, localiza-se no Casal Nordeste, tendo esta sido guiada pela ideia de se elaborar um projecto que fosse susceptível de garantir a salvaguarda sustentada e duradoura dos moinhos lá existentes, através da criação de estruturas físicas e de serviços de apoio que possam conferir ao local uma centralidade aglutinadora de sinergias diversas e possam elevar o local ao estatuto de núcleo-sede dos moinhos da região Oeste. Preconiza-se, pois, que entre o núcleo-sede e os moinhos da região, se possam estabelecer protocolos com benefícios mútuos, passando a funcionar em rede. Ao funcionarem em rede os moinhos poderão ganhar com isso, uma vez que poderá ser maximizada a rentabilidade de exploração e minimizados os custos. Basicamente, prevê-se e promove-se que os moinhos sejam conservados para fins educativos, históricos e etnológicos, quando apresentarem a maioria dos elementos do engenho, e sejam reabilitados para hospedagem em meio rural ou para outros usos quando aquela hipótese não for já viável.
ABSTRACT: The essay title is: “The west windmills heritage rehabilitation: an integrated proposal for the sustainability of the Casal Nordeste windmills”. The essay theorical part has two centerlines, the windmill logical theme general considerations, the milling in its Portuguese historical-cultural context, to point out the social and economical importance of the miller, and also refer to the west windmills specific features, its engines and operation, refering to the safeguard solutions, mischaracter and inadequate intervention. The pratical part is the real intervention, located in the Northwest estate guided by the idea of making a project likely to ensure the windmills in place sustainable, its safeguard and livelong. To create physical structures and hold services that give to this local a centrality of several unifying synergies that can enhance the local status as an head-office of the west windmills. It is advocated that between the head-office and the windmill region, it can be established protocols with mutual benefits like a net working. With windmills working together, exploration can be more profitable and costs minimized. Basically, the windmills preservation can be prevised and promoted for educational, historical and etnological purposes as soon as the majority of the engine elements are rehabilitated, and in case it's not viable it can be used for accomodation in rural environment.
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Dahlbom, Roland. "Off grid eller energiplushus. : Är det möjligt att gå off grid?" Thesis, Mittuniversitetet, Institutionen för kemiteknik, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:miun:diva-39322.
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Målet med den här undersökningen har varit att se om fastigheten Orkestern 1 går att koppla off-grid och om det är ekonomiskt försvarbart eller om en on-grid lösning är bättre. Förutsättningarna är goda med ett stort tak med plats för solpaneler i öst-västlig riktning och en årsmedelvind på 4 m/s. Då huset är nybyggt och välisolerat är även energiförbrukning låg. För att kunna beräkna hur mycket energi som ska produceras i form av värme och el med hjälp av solceller, vindkraftverk, pelletskamin och dieselverk upprättas en energibalans och energifördelning med hjälp av transmission och ventilationsberäkningar. Lagring av energi görs i form av pellets, batteri och biodiesel. Simuleringsprogrammet för solceller Polysun används för att beräkna produktion av solel över varje månad på året. Diagram upprättas över året indelat i månader där det framgår hur stort energibehovet är och visar hur stor del varje energiproducent har varje månad. En pay-off kalkyl görs för att se om det är ekonomiskt lönsamt och för att kunna jämföra mellan två olika off-grid system. Pay-off kalkylen används också för att jämföra mellan off-grid och on-grid system. Resultatet landar i att on-grid systemet är ekonomiskt hållbart medan off-grid systemet inte är det men är ändå fullt genomförbart.The main target of this examination has been to see if the real estate Orkestern 1 has the possibility to go off-grid and if it is economical defendable or if on-grid solution is a better way to go. The prerequisites are good with a large roof to place solar panels to the east and west, a yearly average windspeed at 4 m/s and a low energy consumption because the house is new built and well insulated. To calculate how much energy that must be produced in form of heat and electricity with solar cells, windmills, pellet stove and diesel generator an energy balance and an energy distribution will be prepared with help of calculations of transmission and ventilation loses. Storage of energy will be done in form of pellets, battery and biodiesel. The simulation program for solar panels Polysun is used to calculate the produced solar energy for each month on the year. Diagram is prepared for each month to see the need of energy and how much every energy producer is delivering. A straight pay-off calculation is done to see if there are any economic benefits and to compare between off-grid and on-grid systems. The result will be that on-grid system is better economical but still the off-grid system is doable.
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Galvez, Carrillo Manuel Ricardo. "Sensor fault diagnosis for wind-driven doubly-fed induction generators." Doctoral thesis, Universite Libre de Bruxelles, 2011. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/209982.
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Among the renewable energies, wind energy presents the highest growth in installed capacity and penetration in modern power systems. This is why reliability of wind turbines becomes an important topic in research and industry. To this end, condition monitoring (or health monitoring) systems are needed for wind turbines. The core of any condition monitoring system (CMS) are fault diagnosis algorithms whose task is to provide early warnings upon the occurrence of incipient (small magnitude) faults. Thanks to the use of CMS we can avoid premature breakdowns and reduce significatively maintenance costs.The present thesis deals with fault diagnosis in sensors of a doubly-fed induction generator (DFIG) for wind turbine (WT) applications. In particular we are interested in performing fault detection and isolation (FDI) of incipient faults affecting the measurements of the three-phase signals (currents and voltages) in a controlled DFIG. Although different authors have dealt with FDI for sensors in induction machines and in DFIGs, most of them rely on the machine model with
constant parameters. However, the parameter uncertainties due to changes in the operating conditions will produce degradation in the performance of such FDI systems.
In this work we propose a systematic methodology for the design of sensor FDI systems with the following characteristics: i) capable of detecting and isolating incipient additive (bias, drifts) and multiplicative (changes in the sensor
gain) faults, ii) robust against changes in the references/disturbances affecting the controlled DFIG as well as modelling/parametric uncertainties, iii) residual generation system based on a multi-observer strategy to enhance the isolation process, iv) decision system based on statistical-change detection algorithms to treat the entire residual and perform fault detection and isolation at once.
Three novel sensor FDI approaches are proposed. The first is a signal-based approach, that uses the model of the balanced three-phase signals (currents or voltages) for residual generation purposes. The second is a model-based approach
that accounts for variation in the parameters. Finally, a third approach that combines the benefits of both the signal- and the model-based approaches is proposed. The designed sensor FDI systems have been validated using measured voltages, as well as simulated data from a controlled DFIG and a speed-controlled induction
motor.
In addition, in this work we propose a discrete-time multiple input multiple output (MIMO) regulator for each power converter, namely for the rotor side converter (RSC) and for the grid side converter (GSC). In particular, for RSC
control, we propose a modified feedback linearization technique to obtain a linear time invariant (LTI) model dynamics for the compensated DFIG. The novelty of this approach is that the compensation does not depend on highly uncertain parameters such as the rotor resistance. For GSC control, a LTI model dynamics
is derived using the ideas behind feedback linearization. The obtained LTI model dynamics are used to design Linear Quadratic Gaussian (LQG) regulators. A single design is needed for all the possible operating conditions.
Doctorat en Sciences de l'ingénieur
info:eu-repo/semantics/nonPublished
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Hill, Jennifer L. "Female collegiate windmill pitchers : references to injury incidence." Virtual Press, 2003. http://liblink.bsu.edu/uhtbin/catkey/1260621.
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There is little research specifically examining fast-pitch softball pitchers. However of the few studies completed, pitchers have been reported to exhibit a high incidence of injury. How and why these pitchers are suffering from injuries has not been elucidated.The purpose of this study was to investigate the injuries occurring to collegiate softball pitchers and factors that may influence these injuries such as demographic, pitching, training, and injury information.A cross-sectional survey of collegiate softball pitchers from Divisions I, II, and III was conducted using InQsit, a web-based survey system. Instructions on how to complete a web-based survey was sent and completed over a two-week period, by 181 Division I, II, and III collegiate softball pitchers. The survey was composed of questions addressing: 1) demographic information, 2) pitching and game data, 3) training program information, and 4) injury reporting.The results showed that demographic information, pitching and game data, and training were not statistically significant (p<0.05) in relation to injury. Among the 131 reported injuries, 36 were acute, 92 chronic, and 3 unspecified. Of the 92 chronic/overuse injuries, 10 were Grade I, 30 Grade II, 39 Grade III, and 13 Grade IV. Of the total injuries, 80 were a direct result from pitching, with 36 relating to the shoulder and 17 to the lower back. Among the injured pitchers, 109 took Non-Steroidal AntiInflammatory Drugs, 140 used modalities, 11 received surgeries, and 95 saw additional specialists. This study revealed that a high percentage (72.8%) of collegiate pitchers are suffering injuries across the nation and more research focused on this area is needed. In addition, coaches need to continue to be informed of ways they can improve the health and training programs of their pitchers.School of Physical Education
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Eriksson, Lars Erik Ludvig. "Kvarnverk på Gotland : en teknikhistorisk jämförande undersökning av kvarnverk i hättkvarnar av trä på Gotland." Thesis, Uppsala universitet, Konstvetenskapliga institutionen, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-275270.
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En inventering i början av 1970-talet visade på 255 existerande väderkvarnar (100 stolpkvarnar, 155 hättkvarnar) på Gotland i varierande skick. En småindustriinventering 2001 bekräftade antalet ungefärligt. Dessa inventeringar av Gotlands kvarnbestånd fokuserade helt på det exteriöra och förbisåg kvarnarnas interiörer. Ingen heltäckande inventering har således gjorts av väderkvarnarnas på Gotland interiörer. Många står och ruttnar bort, en del byggs om och många har redan byggts om till fritidsboenden. Varken Länsstyrelsen Gotlands län eller Region Gotland (Gotlands kommun) har i nuläget någon plan för kvarnarna. Medvetenheten och kunskapen är påtagligt liten om kvarnverken i dessa kvarnar, och denna omedvetenhet eller okunskap kan leda till ett ofrivilligt ointresse, inte minst hos beslutsfattare, med den effekten att för eftervärlden värdefull dokumentation inte genomförs, och naturligtvis även att många kvarnverk går förlorade - för alltid. Vi och våra efterkommande går då miste om kunskap om vårt förflutna, om olika historiska uttryck vad gäller teknikhistoria från olika tidsperioder och regioner. Kanske får vi kvar en mindre mängd exempel som talar till oss från det förflutna och som säger ”så här var det”, men verkligheten var mer varierad. Eftersom forskningen om Gotlands väderkvarnar är eftersatt vet vi inte vilka som byggde väderkvarnarna, medan man på andra håll vet namn på kvarnmästare och kvarnmästarfamiljer. Kvarnarna utgör spår efter en månghundraårig hantverkstradition vars hantverksmässiga uttryck nådde sin kulmen under 1800-talet, det århundrade då de flesta av kvarnarna i undersökningen uppfördes i. Denna omedvetenhet eller okunskap om kvarnverken kan leda till tanken och föreställningen att en kvarns interiör bara är ”en sak och inget annat”, vilket i sin tur kan leda till tanken eller beslutsfattandet, att det räcker med att bevara en utvald liten skara kvarnar för eftervärlden, som ska stå och säga till betraktaren, att ”så här var det”, men om en ny tanke lyckas bli etablerad, att det inte alls är ”en sak och inget annat”, utan ”många olika uttryck, inget kvarnverk är riktigt likt ett annat”, blir bevaringsproblematiken genast mer komplicerad, och det är den nya tanken författaren vill etablera hos läsare av olika slag. Författaren har dokumenterat de nitton kvarvarande hättkvarnarna av trä på Gotland (av vilka tolv bedömdes ha tillräckligt med och tillräckligt bevarat kvarnverk i sig för att vara med i undersökningen) i syfte att ge en översiktlig samt jämförande bild av teknikhistoriska uttryck och värden som finns i dem. De delar av kvarnverken som behandlas är: kronhjul, stjärnhjul, krondrev, stjärndrev, pärsar och mötet mellan kvarnhuset och hättan. Undersökningen visar på en mångfald och en varietet i kvarnarna och kvarnverken, att kvarninteriörerna istället för att bara vara ”en sak och inget annat”, är ”många olika uttryck, inget kvarnverk är riktigt likt ett annat”. Undersökningen visar också på skillnader i tidsuttryck vad gäller material och konstruktion, och en teknisk utveckling har på så vis kunnat spåras, bl.a. i och med gjutjärnets intåg under slutet av 1800-talet.An inventory in the early 1970’s showed the existence of 255 windmills (100 postmills, 155 cap-mills) on the Swedish island of Gotland, in varying condition. An inventory of small scale industry on the island in 2001 confirmed the number roughly. These inventories focused on the exteriors and overlooked the interiors. Many of these windmills now rot away, some are being altered and many have been turned into summer houses. Neither Länsstyrelsen Gotlands län (the county administrative board) nor Region Gotland (the local authority) have at present any plan for the windmills. The awareness and knowledge of the machinery in these windmills is evidently small, and this unawareness or ignorance may lead to an involuntary disinterest, not least among decision-makers, to the effect that valuable documentation for the posterity is not being accomplished, and naturally also that many machineries are lost – for ever. We and our descendants then lose knowledge of our past, of different historical expressions of technique-history from different periods and regions. Perhaps a smaller amount of examples will remain to speak to us from the past and say: “This is how it was”, but reality was more diversified. Since the research in windmills on Gotland is neglected, we don’t even know who built them, while in other places names of millwrights or millwright families are known. We have here a craftsmanship of centuries-old tradition, even a neglected profession, whose expressions in craftsmanship culminated in the 19th century, the century in which most of the windmills in this survey were built. This unawareness or ignorance of the windmill machinery may lead to the thought or the notion that the interior of a windmill is just “one thing and nothing else”, which in turn leads to the thought or the decision-making, that it will be enough to preserve just a small amount of chosen windmills for the posterity, which will stand there and tell the onlookers: “This is how it was”, but if a new thought manages to be established, that it isn’t just “one thing and nothing else”, but “many different expressions, no windmill machinery resembles another”, then the preservation problems immediately become more complex, and that is the new thought the author would like to establish among different kinds of readers. The author have documented the nineteen remaining wooden cap-mills on Gotland (twelve of which were judged had enough of and sufficiently preserved machinery to take part in the survey) with the aim to provide a lucid and comparative picture of what technique-historical expressions and values there are in the machineries, expressions and values which heretofore have not been given their due attention. The parts of the windmill machineries which are dealt with are: brake wheels, spur wheels, brake wheel wallowers, spur wheel wallowers, brakes and the meeting between the millhouse and the cap. The survey shows an existing variety in the windmills and their machineries, that these mill interiors are not just “one thing and nothing else”, but rather “many different expressions, no windmill machinery resembles another”. The survey also shows different expressions in time when it comes to material and construction, and a technical development has thus been traced, for example with the entry of cast iron at the end of the 19th century.
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Robinson, Roderick Q. "Desalination of groundwater using reverse osmosis coupled to a windmill." Thesis, Robinson, Roderick Q. (1990) Desalination of groundwater using reverse osmosis coupled to a windmill. Masters by Research thesis, Murdoch University, 1990. https://researchrepository.murdoch.edu.au/id/eprint/52405/.
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Reverse osmosis (RO) has the potential to fulfill the requirements of reliability, small size and low energy input suitable for remote area drinking water desalination by linking this technology to a standard multi-vane windmill pump. The research contained in this Masters thesis covers the design, construction, field testing and performance analysis of a prototype windpowered RO desalination system set up at a site near Murdoch University, Western Australia. The prototype was run from July 1988 for thirteen months, yielding 3348 hours of usable windspeed, direction input data, and desalinated water output data. This data has been analysed and the performance determined for the test site wind regime.
Once performance data was obtained under the measured wind regime, a projection of expected performance using wind data from other areas was constructed to establish the performance of the system in remote settings. The performance projection is based on a production model using variables measured during the test period, which are quantified and matched to the wind characteristics of any site as determined by its windspeed distribution curve. All data is entered into a spreadsheet programme, which calculates the projected performance.
Fouling by feedwater contaminants represents another area of potential problems in RO desalination. The Masters research seeks to address this problem by investigating fouling, both by a literature review and experimentation. The solution to the problem is to adopt a number of pretreatment systems and design solutions which minimize fouling in RO systems.
The thesis draws together these two areas of investigation to predict the performance and pretreatment requirements for groundwater desalinations in a typical remote setting in Western Australia.
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Kong, Zhaoyang. "Entering and Revealing of Architecture_ A Kindergarten at Windmill Hill Park." Thesis, Virginia Tech, 2013. http://hdl.handle.net/10919/19282.
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This thesis topic is focused on the experience of entering and revealing architecture. An entrance is not solely about the physical form of a door, rather it is the beginning of a building; a conversation between public and private, light and dark, safety and danger. The entrance is also a threshold for smell, texture, sound, light, and color. It is the preface of a poem that will lead you to fall in love with the rhythm of the building. It is where beauty begins and never ends.Master of Architecture
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Batuman, Elif. "The windmill and the giant : double-entry bookkeeping in the novel /." May be available electronically:, 2007. http://proquest.umi.com/login?COPT=REJTPTU1MTUmSU5UPTAmVkVSPTI=&clientId=12498.
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Moshtaghe, Gohari Kambiz. "Morphogenèse des moulins à vent d’Iran, techniques de gestion du vent de manière architectonique." Thesis, Paris Est, 2018. http://www.theses.fr/2018PESC1079/document.
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« Le passé est un pays étranger : ils font les choses différemment là-bas » L.P. Hartly Nous avons souhaité nous pencher sur l’histoire des premiers moulins à vent. Plusieurs raisons à cela : une grande partie de l’histoire du moulin à vent demeure obscure et entre autres ; deux choses sont mal connues : la première concerne la date où le moulin à vent à axe vertical apparu pour la première fois en Iran (Perse antique), et la deuxième son évolution, les différents types de cette invention. Dernière raison justifiant la nécessité de notre recherche : il n’y a pas encore d’hypothèse claire permettant d’établir un lien entre les différents types des moulins a vent a axe vertical et présentant une chronologie datée et documentée de l’évolution des types différents, en particulier le moulin à vent à axe vertical iranien. Les sources d’énergie comme le vent – et le moulin à vent sont considérées comme une technologie médiatrice entre le vent et la société humaine. R. J. Forbes , l’historien de la technologie allemand, défendait l’idée que les « moteurs primaires » étaient la « clé de voûte de la technologie ». En utilisant comme critère ces « moteurs primaires », il distingue cinq périodes dans l’histoire de la technologie de l’humanité : l’ère de l’utilisation du muscle d’humain, l’ère de l’utilisation du muscle animal, l’ère de l’énergie fournie par l’eau, l’ère de l’énergie créée par la vapeur et l’ère de l’énergie atomique. Dans sa classification, Forbes n’a pas inclus l’ère de l’énergie du vent ; nous verrons que cette ère est le chaînon manquant entre l’ère de l’énergie hydraulique et l’ère de l’énergie fournie par la vapeur. Avec l’utilisation de l’énergie éolienne, cette ère devient par ailleurs la plus longue de l’histoire de l’utilisation des énergies. Parmi les technologies connues en matière de production d’énergie dans l’Antiquité figure la technologie du moulin à vent, qui a des liens directs avec les deux ères longues et importantes en matière d’utilisation de l’énergie : l’ère de l’énergie hydraulique et l’ère de l’énergie fournie par la vapeur. Malgré tout ce que l’on sait sur l’histoire du moulin à vent européen, l’origine et la diffusion de cette invention technique ne sont pas claires. Maurice Daumas écrit que : « L’origine et la diffusion du moulin à vent posent encore aux historiens de nombreux problèmes et de non moins nombreuses énigmes ». Il manque une chronologie des divers types de moulins à vent dans les diverses civilisations ; par conséquent, une théorie présentant cette diversité architecturale et technique dans le plateau d’Iran fait défaut encore aujourd’hui. La diffusion du moulin à vent dans le monde antique, y a compris l’Iran, pose également question. Une partie importante de cette thèse sera donc consacrée à répondre à ces questions, particulièrement en Iran, dans le but d’éclaircir autant que possible l’origine et la diffusion de cette invention architecturale et technique"The past is a foreign country: they do things differently over there"L.P. Hartly We wanted to look at the history of the first windmills. There are several reasons for this: much of the history of the windmill remains obscure and among others; two things are poorly known: the first relates to the date when the vertical axis windmill appeared for the first time in Iran (ancient Persia), and the second its evolution, the different types of this invention. The last reason for the need for our research is that there is as yet no clear hypothesis for linking the different types of vertical wind mills with a dated and documented chronology of the evolution of types in particular the Iranian vertical axis windmill. Energy sources like the wind - and the windmill are seen as a mediating technology between wind and human society. R. J. Forbes, the German historian of technology, argued that "primary engines" were the "keystone of technology". Using as a criterion these "primary engines," he distinguishes five periods in the history of human technology: the age of human muscle utilization, the era of animal muscle utilization, the era of energy provided by water, the era of energy created by the vapor and the era of atomic energy. In his classification, Forbes did not include the era of wind energy; we shall see that this era is the missing link between the era of hydraulic energy and the era of energy supplied by steam. With the use of wind energy, this era is also the longest in the history of energy use
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Eriksson, Lars Erik Ludvig. "Träslag i kvarnar : En träslagsundersökning av kvarnverken i väderkvarnarna i Eksta socken, Gotland." Thesis, Uppsala universitet, Konstvetenskapliga institutionen, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-275266.
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Då den nuvarande kunskapen om vilka träslag det är i de olika delarna av kvarnverken i gotländska väderkvarnar baserar sig på bristfälliga muntliga uppgifter, har författaren tagit totalt 59 träprov från sju väderkvarnar i Eksta socken, Gotland, och genom mikroskopanalys försökt identifiera träslagen. Resultaten gav fyra olika träslag (furu, ek, oxel och björk) till totalt nio olika delar. Författaren diskuterar sannolika skäl till varför just de träslagen har valts till just de delarna. Resultaten kan anses vara (mer eller mindre) representativa för hela ön. Resultaten har vidare jämförts med uppgifter från Gotland, Öland och Dagö (Estland). En intressant diskrepans uppmärksammades: de delar (kuggar och drevpinnar) som på Öland och Gotland är av oxel (med undantaget björk), är på Dagö av ask eller äppelträd. Övriga delar överensstämmer (mer eller mindre). Författaren sätter detta i samband med en tes som estländaren Dan Lukas har, som går ut på att den estländska kvarntypen tog sig dit söderifrån genom väg över Gotland. Om denna tes skulle stämma, finns det anledning att förvänta sig stora likheter öarna emellan när det gäller träslagsvalen. Anledningen till att kuggarna och drevpinnarna på Dagö, till skillnad från på Öland och Gotland, där de är tillverkade av oxel (och i enstaka fall av björk), tillverkades av ask eller äppelträd, kan bero på att endast enstaka fynd av oxel (eng. Swedish whitebeam) har påträffats där eller att oxel inte alls växte där på den tid då kvarnarna byggdes, medan oxel är allmänt förekommande på Gotland och mindre allmänt förekommande på Öland. Författarens förhoppning är att undersökningens resultat ska kunna fylla ett praktiskt syfte för lokala antikvarier och väderkvarnsägare på ön vid restaurering, ifall en önskan finns om att ersätta eller återskapa skadade delar på ett ”antikvariskt korrekt” sätt, vad gäller materialvalet.The current knowledge of what types of woods there are in the different parts of the Gotland windmill machinery are based on unsatisfactory verbal information. The author has therefore himself taken in total 59 wood samples from seven windmills in the parish of Eksta, Gotland, and through microscope analysis tried to identify the types of woods. The results gave four different types of woods (pine, oak, Swedish whitebeam and birch) for in total nine parts. The author discusses probable reasons to why just those types of woods were chosen to just those parts. The results can be considered (more or less) representative for the whole island. The results have furthermore been compared with information from Gotland, Öland and Dagö (Estonia). One interesting discrepancy was observed: those parts (the cogs and the wallower’s staves) which on Öland and on Gotland are made from Swedish whitebeam (with the exception birch), are on Dagö made from ash or apple tree. Other parts accord (more or less). The author relates this with a theory of the Estonian Dan Lukas, and the drift of that theory is that the Estonian type of windmill came there from the south by way over Gotland. If this theory would be true, there is reason to expect great similarities between the islands when it comes to selection of types of woods. The reason why the cogs and the wallower’s staves on Dagö are made from ash or apple tree, unlike on Öland and on Gotland where they are made from Swedish whitebeam (and in a few cases from birch), can be that only isolated finds of Swedish whitebeam have been found there or that Swedish whitebeam didn’t grow there at all during the time when the windmills were built, while Swedish whitebeam is common on Gotland and less common on Öland. The author’s hope is that the results of the investigation will be able to serve a practical purpose for local antiquarians and windmill owners on the island during restauration work, in case a wish would be existent to replace or recreate damaged parts in an “antiquarian correct” way, with regards to the choice of the material.
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Windmiller, Julia Miriam [Verfasser], and George C. [Akademischer Betreuer] Craig. "Organization of tropical convection / Julia Miriam Windmiller ; Betreuer: George C. Craig." München : Universitätsbibliothek der Ludwig-Maximilians-Universität, 2017. http://d-nb.info/114211371X/34.
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Salomonsson, Sara, and Helena Thoresson. "Windmill driven water pump for small-scale irrigation and domestic use : In Lake Victoria basin." Thesis, University of Skövde, School of Technology and Society, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:his:diva-4222.
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This project is a combination of mechanical engineering and sustainable development in developing countries. The goal has been to build a windmill driven water pump and to design a small-scale irrigation system for SCC-Vi Agroforestry’s demonstration farm in Musoma, Mara region, Tanzania. The purpose was to enable SCC-Vi Agroforestry to demonstrate and spread knowledge about these techniques to farmers in the region.
In 2007, two students from Halmstad University conducted a field study in the Mara region and found that many farmers lack clean and running water. Back in Sweden they constructed a prototype of a windmill that employs wind energy to pump water using a semi-rotary pump. The intention is that local farmers should be able to build their own windmill, and thus have running water in their household. However, the windmill has never been built in Tanzania.
The windmill construction in this report is based on the prototype, but the original drawings were changed to fit the specific situation in Tanzania better. Important throughout the project has been to minimise cost and to only use material that local farmers can get hold of. Building and assembling of the windmill were then performed by the authors in co-operation with local workers. The windmill drives a pump that pumps water from a well to a tank for further use in irrigation.
Calculations have been made on the energy available in the wind and an energy analysis was then performed to see what wind speed is required for the system to work. If wind speed is low, the windmill can be adjusted by placing the connecting rod closer to the rotation centre where it requires less work to function. As a result of that, the volume of water per stroke will decrease and it will take longer time to fill the tank. This project was carried out during the rainy season when there is less wind; therefore the windmill has not been tested during optimal wind speed conditions. The tests that have been performed during the circumstances at the time showed that the performance of the windmill is consistent with the theoretical calculations.
A proposed design for a simple drip irrigation system has been developed based on the conditions at the project area. It is constructed of plastic pipes with holes that emit water. Covers are in place to prevent soil from clogging the holes. Building the irrigation system was not part of this project.
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Poyhonen, Alexander J. "Don Quijote lo Interminable: La Cuestión de los Textos Originales y las Emanaciones a Través de Formas Secundarias de Arte." Scholarship @ Claremont, 2012. http://scholarship.claremont.edu/cmc_theses/522.
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In chapter 1, I ponder the role of authorship and whether or not an original text can truly exist. Specifically, the claim that Borges has that a copy can be superior to an original. From this, brings me to chapter 2 with the movie Man of la Mancha. In this movie, I highlight some of the pros and cons of a copy. The windmill scene is a negative emanation of the Quixote, while the interaction between people and the presence of women is something the movie truly displays well. In the third chapter, I look at Lost in la Mancha because it demonstrates a failed attempt to translate the Quixote. In essence, anything that tries to represent this truly great text will fail; however, it's failure can paradoxically be thought of as a success because it's an homage to the Quixote. As far as the Ezra Pound material, I thought it extremely pertinent to look at his experience on a metro because he attempts to describe a vision that he had through poetry. He notes that it is very difficult to encapsulate his entire experience because the primary form of art (his vision) is being described through a secondary form (words). Thus, when you translate a form of art through a medium it loses some of its value. This is what happens with the Quixote; its primary form (words) is being displayed through a secondary form (film), and it inevitably loses something in the translation. The final chapter/conclusion is a more in-depth investigation of this investigation primary form of art (writing). This uses the character of Gines as a concrete example of a formal and stylistic quality that is unique to literature. Namely, the physical ranging of words on a page in both a spatial and literary sense. When you extract those lines from a novel you implicitly remove some of the dialectic between Cervantes' work and the genres he's invoking, just by taking it out of the form of literature. The surroundings of text establish the meaning of the novel. The conclusion is my final chance to argue why the Quixote is so special and untranslatable. I touch on the qualities that keep it forever live and present in us today. Through the Quixote's proclivity for renaming the real world (established societal beliefs/values, etc.) in his own vein, Cervantes allows for the Quixote to reappropriate the world around him, making it uniquely his. In so doing, Cervantes creates a character who is able, not only to write his own self-history, but to control the way that said self-history will be written by others. By blurring the lines between narrator and narration and history and fiction, Cervantes creates a work that is endlessly present, where words becoming living page, and actions occur as they are said.
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Craddock, Michael Charles. "The windmill and the giant : Don Quijote and the eighteenth-century English novel; being a study of three Quixotic novels and their Cervantine context." Thesis, University of York, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.238712.
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Marchandin, Pierre. "Moulins et énergie à Paris du XIIIe au XVIe siècle." Thesis, Université Paris sciences et lettres, 2021. http://www.theses.fr/2021UPSLN002.
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L’étude de la place des dispositifs de production d’énergie renouvelable dans la satisfaction des besoins des sociétés préindustrielles a beaucoup à apporter à la compréhension des enjeux du débat autour de la transition énergétique. Afin d’envisager de manière nouvelle cette question, à laquelle de nombreuses réponses se trouvent à l’échelle des grandes villes, le présent travail se propose d’examiner la manière dont ces dispositifs, et en particulier les moulins à eau et à vent, contribuèrent à satisfaire la demande énergétique de la région métropolitaine du Paris médiéval, comptant, à l’aube du XIVe siècle, environ 250 000 habitants. Grâce à un corpus de documents et d’images en grande partie inédit, il dresse un tableau qualitatif, quantitatif et relationnel de l’équipement énergétique de la capitale, et met au jour les évolutions qu’il connut entre le XIIIe et le XVIe siècles, démentant l’idée d’un système énergétique préindustriel figé. Il s'intéresse également à la façon dont l'approvisionnement en énergie et l'installation des infrastructures énergétiques ont constitué un enjeu politique et institutionnel mobilisant de nombreux acteursThe study of the place of renewable energy providing devices took in the satisfaction of preindustrial societies’ needs is very useful to understand what is at stake in the energetic transition debate. In order to address this question from a new perspective, and given that quite a few answers can be found on the scale of large cities, the present work aims at examining how those installations, and especially watermills and windmills contributed to satisfying the energetic demands of the metropolitan region of medieval Paris, which counted about 250,000 inhabitants in the early 14th century. Through a corpus of documents and images – most of which have never been previously published – it paints a qualitative, quantitative and relational picture of the Parisian energetic equipment and highlights its evolutions between the 13th and the 16th centuries, thus contradicting the idea of a fixed preindustrial energetic system. This work also studies the way energy providing represented a political and institutional issue, mobilizing numerous stakeholders
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Bruyerre, Philippe. "Dynamiques d'innovation technique et d'intégration socio-économique. : le cas de l'éolienne en Allemagne, au Danemark et en France." Thesis, Paris, EHESS, 2017. http://www.theses.fr/2017EHES0144.
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L’étude de cas de l’« éolienne » est abordée au travers de quatre scènes techniques : moulins à huile à Lille à la fin du XVIIIe siècle, moulins électriques au Danemark au tournant du XXe siècle, aérogénérateurs en France dans les années 1950, éoliennes modernes à la fin du XXe siècle en Allemagne du Nord. Chacune de ces scènes techniques fait l’objet d’une analyse technique articulée autour de la connaissance du vent, de l’aérodynamique et de la mécanique des structures et d’une analyse socio-économique centrée sur le secteur d’activité dans lequel elles sont intégrées, pour comprendre ce que les gens font avec cet objet technique. Cette recherche montre que toutes les éoliennes ayant connu une large diffusion sont fondées sur une même architecture globale et sur un même principe physique permettant de définir des indicateurs de performance et de régularité sur une longue période. Envisagée comme machine de production et non comme convertisseur d’énergie, chaque éolienne est optimale dans le contexte technique et socio-économique de son époque. L’histoire des techniques proposée s’articule autour de la notion de fonction en relation d’une part avec le fonctionnement opératoire d’une combinaison de structures matérielles, d’autre part, l’intention de concepteurs et d’utilisateurs agissant suivant des normes sous-tendues par des valeurs morales, esthétiques et culturellesThe case study of the "wind turbine" is analyzed through four technical scenes: oil mills in Lille at the end of the 18th century, electric mills in Denmark at the turn of the 20th century, aerogenerators in France in the 1950s, modern wind turbines in the late twentieth century in northern Germany. Each of these technical scenes is the subject of a technical analysis based on the knowledge of wind, aerodynamics and structural mechanics and a socio-economic analysis centered on the sector of activity in which they are integrated, to understand what people are doing with this technical object.This research shows that all wind turbines that have been widely distributed are based on the same global architecture and on the same physical principle allowing the definition of indicators of performance and regularity over a long period. Considered as a production machine and not as an energy converter, each wind turbine is optimal in the technical and socio-economic context of its time.The proposed history of the techniques revolves around the notion of function in relation, on the one hand, to the operation of a combination of material structures and on the other to the intention of designers and users acting according to standards underpinned by moral, aesthetic and cultural values
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Ortolan, Aurélie. "Etude aérodynamique de ventilateurs axiaux réversibles à performance duale compresseur/turbine élevée." Thesis, Toulouse, ISAE, 2017. http://www.theses.fr/2017ESAE0019/document.
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Dans le contexte des avions plus électriques, le potentiel de récupération d'énergie de ventilateurs de refroidissement embarqués est étudié. Ces compresseurs conventionnels, utilisés uniquement au sol, fonctionnent en autorotation libre en vol. Dans cette dernière configuration, appliquer un couple donné sur l'arbre permet de récupérer de l'énergie électrique, le ventilateur fonctionne alors en autorotation chargée (mode turbine). Cependant, ces géométries conventionnelles obtiennent de faibles rendements turbine, causés par des incidences fortement négatives conduisant à des décollements massifs. Il est alors nécessaire de concevoir une machine axiale réversible capable de fonctionner de manière duale en mode compresseur et turbine, avec une performance élevée dans les deux cas. Ce nouveau concept permet de capitaliser l’équipement tout au long de la mission. Dans cette étude, l'adéquation de l'approche quatre-quadrants et du formalisme psi-phi à propos du mode dual de turbomachines est soulignée, au détriment des représentations classiques séparant les performances compresseur et turbine. Une analyse du fonctionnement du mode compresseur à l'autorotation chargée a permis de mettre en évidence les propriétés génériques des écoulements d'autorotation ainsi que ce qui fait la spécificité des machines duales. Les mécanismes de l’écoulement et les paramètres géométriques impactant la performance le long de la ligne de fonctionnement ont également été identifiés. Le concept de machine duale est validé grâce aux grands rendements obtenus en essais. Enfin, une géométrie optimisée est proposée et des recommandations liées au design de machines duales sont donnéesIn the more electric aircrafts context, the in-flight windmilling operation of conventional onboard axial fans is regarded as a functioning mode that enables energy recovery. Poor turbine efficiencies of classical geometries, due to massive separations, require to design a reversible machine. The latter allows a dual compressor/turbine functioning with high performances in both modes to capitalize the equipment throughout the mission. In this study, the relevance of psi-phi formalism to multi-quadrant approach is underlined. The flow analysis from compressor to load-controlled windmill enables to highlight generic properties of windmilling flows as well as dual machines specificities. The flow mechanisms and geometrical parameters impacting the performances along the operating line are also identified. Finally, an optimized dual machine design is proposed
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Pallesen, Trine. "L’assemblage d’un marché de l'électricité éolienne : analyse de la construction de dispositifs de marché." Thesis, Paris, ENMP, 2013. http://www.theses.fr/2013ENMP0019/document.
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Ce projet étudie la réalisation d’un marché d’énergie éolienne en France. Les marchés d'énergie éolienne sont souvent désignés comme des «marchés politiques» : D'une part, l'énergie éolienne réduit les émissions de CO2 et retarde les effets de la production d'électricité sur le changement climatique. D'autre part, comme bien économique, l'énergie éolienne se dit souffrir «d’handicaps» technico-économiques (les coûts élevés, la production fluctuante et imprévisible, etc.). Par conséquent, en raison de sa performance comme bien économique, il est argumenté que la survie de l'énergie éolienne dans le marché est fondée sur différents instruments, dont certains que je qualifierai de «prothèses». Cette thèse s’interroge sur deux de ces prothèses : Le tarif d’achat et les Zones de Développement Eolien (ZDE) comme ils sont négociés et mis en pratique en France, ainsi que la manière dont ils affectent la réalisation des marchés de l'énergieThis project studies the making of a market for wind power in France. Markets for wind power are often referred to as ‘political markets: On the one hand, wind power has the potential to reduce CO2-emissions and thus stall the effects of electricity generation on climate change; and on the other hand, as an economic good, wind power is said to suffer from (techno-economic) ‘disabilities', such as high costs, fluctuating and unpredictable generation, etc. Therefore, because of its performance as a good, it is argued that the survival of wind power in the market is premised on different instruments, some of which I will refer to as ‘prosthetic devices'. This thesis inquires into two such prosthetic devices: The feed-in tariff and the wind power development zones (ZDE) as they are negotiated and practiced in France, and also the ways in which they affect the making of markets for wind power. Theoretically, this dissertation mobilizes a constructivist approach according to which markets are seen as socio-technical assemblages, stressing the heterogeneous and distributed character of their constituent elements. Furthermore, the approach allows questioning the deadlocked delineation between politics and economics, a delineation that appears to underlie the idea of the political market. Based on fieldwork in France, the core of this thesis is made up of two analyses; firstly, the definition of a feed-in tariff is empirically followed as a process of valuation in which value is seen as the outcome of irregular and costly activities, rather than the identification of an inherent value.To study how value, here in the form of a price, comes about in the case of wind power, five different empirical traces are followed with each one representing a distinct approach to valuation. These valuation proposals involve qualifying and disqualifying wind power, e.g., from CO2-reducing to CO2-emitting, and they span a range of controversies. The second analysis addresses the ZDE-device. It follows the device along two phases; namely, its conception and its emerging practice in a specific case, the territory of Pays de la Serre. The first phase is discussed as a politicization of wind power, a distinct framing of location in which the possibility for local opposition is enforced. The second phase, i.e. the practice of the device in Pays de la Serre, is better described as an economization of the landscape, a process of translating the territory according to one-dimensional layers. In their final presentation, these layers are accumulated and black-boxed, and the criteria for their construction disappear
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Alves, Andreia Luísa da Costa. "O complexo arqueológico de São Fausto do Torrão: memória e identidades." Master's thesis, Universidade de Évora, 2018. http://hdl.handle.net/10174/23691.
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O presente trabalho consiste na divulgação do potencial histórico e arqueológico do sítio de São Fausto. Visto que nunca foi alvo de escavações arqueológicas ou de outro trabalho aprofundado de investigação, pretende-se, com este trabalho, que o sítio de São Fausto seja divulgado e que o seu estudo possa contribuir para uma melhor compreensão da história dos torranenses e do Torrão.
Com base maioritariamente nas prospeções arqueológicas e posterior recolha e análise do espólio recolhido no campo, este trabalho tentou desenhar uma linha cronológica que permitisse perceber que ocupações o sítio tivera.
Os distintos períodos cronológicos que estão presentes no Complexo Arqueológico de São Fausto foram o ponto de partida para a realização desta dissertação. Numa tentativa de perceber de que forma é que cronologias que vão deste o período do Neolítico até à Idade Contemporânea se podem relacionar num mesmo espaço, chegando-se à conclusão de que estamos perante um sítio sem interregnos de ocupação;
Abstract: The archaeological complex of São Fausto do Torrão: memory and identities
The present work consists on the divulgation of the historical and archaeological potential of the São Fausto place. Since it has never been the object of archaeological excavations or other in-depth research, it is intended, with this work, that the place of São Fausto could be published and that its study may contribute to a better understanding of the history of Torrão and its people.
Based mainly on the archaeological prospects and analysis of the assets collected in the field, this work tried to draw a chronological line that allowed to realize what occupations the place had.
The different chronological periods that are present in the Archaeological Complex of São Fausto were the starting point for this dissertation. In an attempt to understand how the chronologies ranging from the Neolithic period to the Contemporary Age could be related in the same space, we came to the conclusion that we are facing something without any interludes of occupation.
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Kayahan, Hüseyin. "INTRUSION EXECUTION SYSTEMS : Prototype: IMPETUS." Thesis, Linnéuniversitetet, Institutionen för datavetenskap (DV), 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:lnu:diva-29546.
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In nature, it is inspiring to observe such an extensive variety of defensive skills distributed among species. The speed of an antelope, and the sting of a scorpion, wasp or a bee are some examples of such defensive tools or mechanisms important to survive against predators. However sophisticated the skills or tools are, the correct accurate use and on-time triggering of those tools is a matter of life and death for animals. With those defensive measures, animals come with a complementary ability called "vigilance". Vigilance is costly and the human tries to minimize vigilant behaviour in every aspect of life. The absence of vigilance, or negligence in other words, allows humans to spend more time and cognition on matters that he or she wants rather than on problems that need time. The human has an inherent and intricate mechanism that determine the vigilance level required for a particular problem. The consequences of the lack of vigilance in a work environment, more especially in the Information Technologies Security field are catastrophic and even lethal as humanity becomes an increasingly associated habitant of cyberspace ecosystem. Intrusion Execution Systems (IES) which is one of my conceptual propositions in this research, is my approach to reduce negligent behaviour in IT Security personnel. Impetus is the name of the first prototype for IES concept with limitations, which is included in this research. Impetus can successfully achieve desired behaviour in test environment, however the conceptual propositions in this research among with Impetus, should further be experimented in real-world in order to be convinced of its effectiveness.
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Lokuge, Meepa A. "Tissue Culture, Genetic Transformation and Cold Tolerance Mechanisms in Cold-Hardy Palms." Miami University / OhioLINK, 2006. http://rave.ohiolink.edu/etdc/view?acc_num=miami1165607767.
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Subramanian, Rohit. "COMPUTATIONAL FRAMEWORK TO ASSESS ROLE OF MANUFACTURING IN MATERIAL-DEFECT RELATED FAILURE RISK." The Ohio State University, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=osu1398998282.
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Cisneros, Montoya Rafael. "Commande PI basée sur la passivité : application aux systèmes physiques." Thesis, Université Paris-Saclay (ComUE), 2016. http://www.theses.fr/2016SACLS187/document.
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Le régulateur PID (Proportionnel-Intégral-Dérivée) est la commande par retour d'état la plus connue. Elle permet d'aborder un bon nombre de problèmes de commande, particulièrement pour des systèmes faiblement non linéaire et dont la performance requise est relativement modeste. En plus, en raison de sa simplicité, la commande PID est largement utilisée en l'industrie. Étant donnés que les méthodes de réglage de la commande PID sont basées sur la linéarisation, la synthèse d'un contrôleur autour d'un point d'équilibre est relativement simple, néanmoins, la performance sera faible dans des modes de fonctionnement loin du point d'équilibre. Pour surmonter ce désavantage, une pratique courante consiste en adapter les gains du PID, procédure connue sous le nom de séquencement de gain (ou gain-scheduling en anglais). Il y a plusieurs désavantages à cette procédure, comme la commutation des gains de la commande et la définition -non triviale- des régions de l'espace d'état dans lesquelles cette commutation aura lieu. Ces deux problèmes se compliquent quand la dynamique est fortement non linéaire. Dans d'autres méthodes, la synthèse de la commande utilise des schémas empiriques, ce qui ne permet pas l'analyse de la stabilité globale du processus. Dans ce contexte, ce travail de thèse a pour objectif de synthétiser des contrôleurs PI, basés sur la passivité, de telle sorte que la stabilité globale du système en boucle fermé soit garantie. L'un des avantages à utiliser la passivité est son attrait intuitif, qui exploite les propriétés physique des systèmes. L'idée centrale dans un système passive est que l'écoulement d'énergie entrante au système provenant de l'extérieur n'est pas inférieur à l'incrément de son énergie de stockage. Par conséquence, ces systèmes ne peuvent pas stocker plus d'énergie que celle fournie, dont la différence correspond à l'énergie dissipée. En introduisant le concept d'énergie, cette méthodologie nous permet de formuler le problème de commande en celui de trouver un système dynamique dont la fonction de stockage d'énergie prend la forme désirée. En incorporant le concept d'énergie cette méthode devient accessible à la communauté de praticiens et permets de fournir des interprétations physique de l'action de commande. Dans cette thèse, une méthodologie constructive de commande PI basée sur la passivité est présentée et motivée par des applications à des systèmes physiquesOne of the best known forms of feeding back a system is through a three-term control law called PID (Proportional-Integral-Derivative) controller. PID controllers are sufficient for many control problems, particularly when process dynamics are not highly nonlinear and the performance requirements are modest. Besides, because of its simple structure, the PID controller is the most adopted control scheme by industry and practitioners, beeing the PI the form mostly employed. Since the PI tuning methods are based on the linearization, commissioning a PI to operate around a single operating point is relatively easy, however, the performance will be below par in wide operating regimes. To overcome this drawback the current practice is to re-tune the gains of the PI controllers based on a linear model of the plant evaluated at various operating points, a procedure known as gain-scheduling. There are several disadvantages of gain-scheduling including the need to switch (or interpolate) the controller gains and the non-trivial definition of the regions in the plants state space where the switching takes place - both problems are exacerbated if the dynamics of the plant is highly nonlinear. In other common scenarios, a little information about the process dynamics or only a "good" linear approximation is taken into account when designing the control design. This impedes to analyse the global stability of the system. In this context, the current thesis work is aimed at the designing of PI controllers, based on the passivity theory, such that the stability of the closed-loop system is guarantied. One of the main advantages of passivity concepts is that they offer a physical and intuitive appeal. The primary idea in passive systems is that the power flowing into the system is not less that the increase of storage. Thus, they cannot store more energy than is supplied to it from the outside, with the difference being the dissipated energy. Thus, introducing the concept of energy, this methodology allows to recast the control problem as finding a dynamical system such that system energy function takes the desired form. Also, with this formulation, the communication between practitioners and control theorists is facilitated, incorporating prior knowledge of the system and providing physical interpretations of the control action. In this thesis, a constructive methodology for deriving PI passivity-based controllers is presented and motivated by the application to physical systems
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Sýkora, Martin. "Studie připojitelnosti výrobny." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2011. http://www.nusl.cz/ntk/nusl-219019.
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It is necessary to judge the influences of producers on the electric compounds while creating electrical energy or during the regulation of those existing. These analyses are sorted out by so called studies of connectivity. These calculations analyze the degree of connection of the producer and the standby unit during a break-down. The results of this report are several recommendations for creating such unit and succeeding steps leading to secure the stability and safety of the electric compound operation. The aim of this thesis is to discuss about software for PC solutions for static and dynamic network model, to draft power outlet into a network of generating high voltage, to complete a study of connectivity with respect to all the distortion factor, as increased voltage, inrush current at startup, flicker, harmonic currents, interference ripple, contribution to short-circuit current, reactive power control options, and demands for compensation.
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Liang, Percy, and Nati Srebro. "How Much of a Hypertree can be Captured by Windmills?" 2005. http://hdl.handle.net/1721.1/30515.
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Current approximation algorithms for maximum weight {\em hypertrees} find heavy {\em windmill farms}, and are based on the fact that a constant ratio (for constant width $k$) of the weight of a $k$-hypertree can be captured by a $k$-windmill farm. However, the exact worst case ratio is not known and is only bounded to be between $1/(k+1)!$ and $1/(k+1)$. We investigate this worst case ratio by searching for weighted hypertrees that minimize the ratio of their weight that can be captured with a windmill farm. To do so, we use a novel approach in which a linear program is used to find ``bad'' inputs to a dynamic program.
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Worthen, Shana Sandlin. "The memory of medieval inventions, 1200-1600 : windmills, spectacles, mechanical clocks, and sandglasses." 2006. http://link.library.utoronto.ca/eir/EIRdetail.cfm?Resources__ID=442401&T=F.
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Lin, Chi-Chia, and 林其加. "Development of Casting Technologies for Heavy Section Ductile Iron Castings Used in Large-scale Windmills." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/18601036216885410456.
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碩士國立臺灣大學
機械工程學研究所
101
The primary purpose of this research is to establish the optimal alloy design and microstructure for achieving the desired mechanical properties (tensile strength, yield strength, elongation and low temperature impact value) of key casting components used in large-scale windmills. Based upon the experimental results from cast-on specimens (series A), multiple regression analyses have been performed to correlate the mechanical properties with chemical compositions and microstructures. The derived regression equations can be used to attain the optimal alloy design for castings with targeted specification. Furthermore, by employing these regression equations, the mechanical properties can be predicted based upon the chemical compositions and microstructures of cast irons. On the other hand, the type of pig irons, the addition amount of nodularizer, ladle and late inoculant, and the method of late inoculation were also investigated in this study. Furthermore, computer simulation was performed on 2 MW main frame casting to simulate the filling and solidification phenomena for achieving the optimal gating and riser system design.
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Babu, Harish, and Dona Maria Mathew. "A Feasibility Study and Business Model for Micro Vertical Axis Wind Turbine in Sweden." Thesis, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:hh:diva-44712.
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This project is a part of the master thesis for the course Energy smart innovation in the built environment at Halmstad University. This project is done to check the feasibility of VAWT on replacing traditional horizontal axis windmills, costly offshore windmills, and other renewables. As Micro VAWT are smaller, they can be placed where traditional windmills will not be. To stress the point, these can be placed in places like traffic islands and open garden areas. Lots of such projects are currently ongoing in different parts of the world. Sweden is lagging in this technology diffusion. We concluded that VAWM couldn't alone be used to replace traditional HAWTs or be enough to reach the full renewable target. They can be used in conjunction with HAWT to boost production and efficiency, and we also found other similar uses for VAWM. A business model is suggested so as for the optimal diffusion of VAWT. Our proposal of a micro VAWT of 1.8 million was able to produce 1.41TWh.We found that it was not possible to achieve with VAWT alone.
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Chin-Ling, Chang Chien, and 張簡金玲. "FASTPITCH SOFTBALL Windmill Pitching." Thesis, 2001. http://ndltd.ncl.edu.tw/handle/57167808906224792542.
Full textAbstract:
碩士國立體育學院
教練研究所
89
Fastpitch softball became a women''s Olympic sport in 1996. Underhand pitching presents power and acceleration characters same with baseball. But windmill style is different than baseball pitching. Pitcher is the key ingredient and make such much a significant contribution in fastpitch. The subjects of this research are the pitchers chosen from the final games of 1999 I.S.F.Ⅵ Junior Women''s World Championship. This report is intended to collect as much of information derived from the publications, books and experiences. The report contains the results of what author had been learning during 4 years of research and 29 years experiences of pitcher and pitching coach. The content of the report is composed of six parts. There are chapter one fastpitch development, chapter two fitness training, chapter three technique and mechanics, chapter four pitching tactics and strategies, chapter five pitching psychology, chapter six health management. It is a appropriate to expand on some physiological basics and exercise physiology protocols to maximize results for achieving peak pitching performance. The human mind and feelings can be trained with scientific theory and experience to support proper mechanics and physical conditioning. Applying pitching knowledge before training is the main purpose of this report. It will provide a comprehensive understanding of the aspects of pitching benefiting coaches and players on developing effective ways and reaching individual potential. Key words:Softball,Fastpitch,Pitching,Pitcher