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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
531

Optimisation topologique de dispositifs électromagnétiques / Topology optimisation of electromagnetic devices

Mohamodhosen, Bibi Safoorah Bilquis 06 December 2017 (has links)
L’Optimisation Topologique (OT) est un sujet en plein essor qui suscite l’intérêt de nombreux chercheurs depuis ces deux dernières décennies dans le domaine de l’électromagnétisme. L’OT représente une méthode très attrayante et originale car elle permet de trouver des structures innovantes sans aucun a priori. Ce travail de thèse est orienté vers l’OT des dispositifs électromagnétiques en approfondissant plusieurs aspects du sujet. Tout d’abord, un outil d’OT est développé et testé, à partir des outils existant au L2EP. En effet, l’OT requiert un outil d’éléments finis et un outil d’optimisation devant être couplés. Une méthodologie originale d’OT fondée sur les principes de la Méthode de Densité est développée et testée. Un cas test académique est utilisé afin de tester et valider le couplage des outils et la méthodologie. Une approche visant à prendre en compte le comportement non-linéaire des matériaux ferromagnétiques avec nos outils OT est également mise en place. Ensuite, la méthode est appliquée afin d’optimiser un électroaimant en 3 dimensions, représentant un cas test proche de la réalité. Ce cas test permet de comparer les résultats avec un comportement linéaire et non-linéaire des matériaux. Diverses topologies sont présentées, par rapport aux différentes formulations du problème. Par la suite, la méthodologie est appliquée à un dispositif électromagnétique plus complexe : une Génératrice Synchrone à Pôles Saillants. Cet exemple nous permet de voir comment la définition du problème d’optimisation peut grandement affecter les résultats d’OT. Quelques topologies sont présentées, et leur faisabilité est analysée / Topology Optimisation (TO) is a fast growing topic that has been sparking the interest of many researchers for the past two decades in the electromagnetic community. Its attractiveness lies in the originality of finding innovative structures without any layout a priori. This thesis work is oriented towards the TO of electromagnetic devices by elaborating on various aspects of the subject. First of all, a tool for TO is developed and tested, based on the ‘home-made’ tools available at the L2EP. As TO requires a FE and an optimisation tool working together, a coupling is done using both. Furthermore, a TO methodology is developed and tested, based on the Density Method. An academic cubic test case is used to carry out all the tests, and validate the tools and methodology. An approach is also developed to consider the nonlinear behaviour of the ferromagnetic materials with our TO tools. Afterwards, the methodology is applied to a 3D electromagnet, which represents a more real test case. This test case also serves to compare the results with linear and nonlinear behaviour of the materials used. Various topologies are presented, for different problem formulations. Subsequently, the methodology is applied to a more complex electromagnetic device: a Salient Pole Synchronous Generator. This example allows us to see how the problem definition can largely affect TO results. Some topologies are presented and their viability is discussed
532

Mladá - mezi zánikem obce a vznikem vojenského cvičiště (1904-1906) / Mladá - between the Destruction of Village and the Emergence of the Military Training Ground (1904-1906)

Šálová, Andrea January 2013 (has links)
1. 4. ABSTRACT Diploma Thesis Mladá - Between the Destrution of Village and the Emergence of Military Training Ground (1904-1906) discusses the turbulent lives of the parish community on Benátky-Region, which, in 1904, was in the very center of planned artillery firing ranges and military training ground of the Austro-Hungarian army. As the only one of the affected villages, Mladá was doomed, people were forced to move, and the local buildings were used to house troops, and, subsequently, they were used as artillery targets. Sacrificing Mladá village in fact brought economic prosperity to the surrounding municipalities. The Transport infrastructure had improved, local trade got new impulses, agriculture production found a new outlet in the army etc. Finally, the dissolution of Mladá village led to the emergence of a new micro-regional center, when a small village of Milovice became a town that still commemorates this historical event village through the name of one of its urban parts - Mladá.
533

Controle fuzzy via alocação de pólos com funções de Lyapunov por partes / Fuzzy pole placement based on piecewise Lyapunov functions

Eduardo Stockler Tognetti 31 March 2006 (has links)
O presente trabalho apresenta um método de projeto de controlador com alocação de pólos em sistemas fuzzy utilizando funções de Lyapunov por partes e contínuas no espaço de estado. A idéia principal é utilizar controladores chaveados no espaço de estado para obter uma resposta transitória satisfatória do sistema, obtida pela localização dos pólos. A modelagem fuzzy Takagi-Sugeno é utilizada para representar um sistema não-linear em diversos pontos de linearização através de uma aproximação por vários modelos locais lineares invariantes no tempo. A análise de estabilidade e o projeto de sistemas de controle podem se formulados em termos de desigualdades matriciais lineares (em inglês, linear matrix inequalities (LMIs)), as quais são resolvidas por técnicas de programação convexa. Na análise de estabilidade ou na síntese de um controlador em sistemas fuzzy é necessário resolver um número determinado de LMIs de acordo com o número de modelos locais. Encontrar uma função de Lyapunov comum a todos os modelos locais pode ser inviável, especialmente quando se impõem critérios de desempenho, que aparecem como restrições no contexto de LMIs. A proposta de uma função de Lyapunov por partes objetiva diminuir o conservadorismo na busca de um controlador que leve os pólos de malha fechada à uma região desejada. Resultados de análise e síntese da teoria de sistemas lineares por partes contribuíram para a construção do resultado apresentado. Exemplos com simulação ilustram o método proposto. / This work presents a controller design method for fuzzy dynamic systems based on piecewise Lyapunov functions with constraints on the closed-loop pole location. The main idea is to use switched controllers to locate the poles of the system to obtain a satisfactory transient response. The pole placement strategy allows to specify the performance in terms of the desired time response of the feedback system. The Takagi-Sugeno fuzzy model can approximate the nonlinear system in several linearization points using linear time invariant systems. Thus, a global fuzzy model can be obtained from a fuzzy combination of these linear systems. Stability analysis and design of fuzzy control systems can be efficiently carried out in the context of linear matrix inequalities (LMIs). If the fuzzy system is described by many local models, the resulting set of LMIs may be infeasible. The search for a Lyapunov function in the fuzzy pole placement problem may be easier to be satisfied in a piecewise framework. Some results from piecewise linear systems theory have contributed to the development of the presented technique. Some examples are given to illustrate the proposed method.
534

Semiklasická energie eliptické Nambuovy-Gotovy struny / Semi-classical energy of elliptic Nambu-Goto string

Kozoň, Marek January 2018 (has links)
Po zhrnutí potrebných teoretických základov a predošlého výskumu v ob- lasti, prezentujeme semi-klasickú kvantovaciu schému pre uzavretú Nambuovu- Gotovu strunu. Týmto zovšeobecňujeme predošlú prácu, ktorá bola vykonaná pre otvorenú strunu a uzavretú strunu kruhového tvaru. Pomocou metód kvan- tovej teórie po©a v zakrivených priestoročasoch počítame strednú hodnotu vo©- ného Hamiltoniánu struny rotujúcej v dvoch na seba kolmých priestorových rovinách v priestoročase všeobecnej dimenzie. Táto hodnota je priamo úmerná kvantovej korekcii k celkovej energii struny, ktorá má formu tzv. Reggeovho interceptu. Výslednú hodnotu Reggeovho interceptu porovnávame s predošlým výskumom. Taktiež uvádzame porovnanie získaného spektra fyzikálnych stavov struny kvantovanej našou metódou so spektrom odvodeným pomocou kovariant- ného kvantovania. 1
535

Conceptions de machines électriques à trajectoires de flux 3D pour application automobiles considerant la réutilisation et le recyclage des aimants / Electrical machine designs based on 3D flux paths with reuse & recycle magnet concepts for automotive applications

Upadhayay, Pranshu 11 December 2018 (has links)
Les travaux de recherche présentés dans cette thèse visent à développer une machine à griffes à base d'aimants permanents pour les applications automobiles avec un concept de réutilisation et de recyclage des aimants permanents. Ces recherches sont menées dans le cadre du projet DEMETER, qui s'inscrit dans le cadre des Marie Sklodowska-Curie Actions dans Horizon 2020 de l'Union européenne. Le projet se concentre sur la récupération des aimants permanents à base de terres rares utilisés dans les applications automobiles en raison des problèmes actuels de fluctuation des prix et des problèmes d’offre et de demande de ces aimants permanents.La machine à griffes est utilisée dans presque toutes les automobiles du monde pour les applications d'alternateur. Avec l'augmentation de la demande en puissance, la machine à griffes est également développée en tant que moteur-générateur utilisé dans les véhicules électriques hybrides. Actuellement, la machine à griffes à base d'aimants permanents est utilisée dans des systèmes d’hybridation légère afin de réaliser des économies d'énergie. La littérature regorge de différentes configurations de machines à griffes pouvant être développées pour obtenir de meilleures performances. Cependant, le montage et le démontage facile des différentes parties de la machine sont également importants pour la réutilisation et le recyclage des aimants. Dans ce travail de recherche, deux concepts ont été développés; premièrement, le concept de réutilisation directe, c’est-à-dire le montage / démontage facile du rotor et des aimants, de manière à pouvoir retirer facilement les aimants pour les réutiliser ou les recycler directement; deuxièmement, le concept de recyclage direct, c'est-à-dire l'utilisation d'aimants recyclés dans la machine pour obtenir les performances souhaitées.Au cours de cette recherche, la conception de base de la machine à griffes a été développée, analysée et optimisée de manière à obtenir le meilleur rapport couple / poids aimant. Cela a permis de réduire le coût des aimants pour presque le même couple. L'optimisation a été effectuée en utilisant une analyse numérique en éléments finis 3D. Le modèle optimisé a été développé de manière à ce que le processus d’assemblage des aimants et des griffes reste le même. Cependant, lors du démontage, les aimants peuvent facilement être retirés sans démonter le rotor complet; et ainsi se servir de ces aimants pour les réutiliser directement dans d'autres applications ou les envoyer au recyclage. Dans le concept de recyclage direct, les aimants utilisés dans la machine sont des aimants recyclés aux performances dégradées. Le type de processus de recyclage est un facteur déterminant de la détérioration des performances de ces aimants recyclés. L'objectif du concept de recyclage direct était d'analyser la machine avec des aimants vierges et recyclés et d'évaluer la consommation d'énergie de la machine selon différents cycles de conduite. On a observé qu'avec l'utilisation d'aimants recyclés dans la machine à griffes, la consommation d'énergie était presque identique à celle de la machine à aimants vierges. On peut donc en conclure que pour les machines à griffes à aimants permanents, l’utilisation d’aimants recyclés est plus durable pour l’environnement car elle peut entraîner une diminution à l’extraction des matériaux de terres rares. Les fluctuations des prix et les problèmes d’offre peuvent également être réduits grâce à l’utilisation accrue des aimants recyclés, même si des politiques et des normes sont appliquées.Le prototype de la machine à aimants vierges a été fabriqué et testé pour ses performances. Il a été observé que les résultats expérimentaux correspondent très bien aux résultats des analyses de conception, validant ainsi le processus de conception et la méthodologie. / The research work presented in this thesis aims at developing a permanent magnet based claw-pole machine for automotive application with permanent magnet reuse and recycle concept. The aforesaid research is under the aegis of Project DEMETER which is in the framework of European Union’s Horizon 2020 Marie Sklodowska-Curie actions. The project focuses on the recovery of rare earth permanent magnets utilized in automotive applications due to the prevailing problems of price fluctuations and supply-demand issues of these permanent magnets.The claw-pole machine is employed in almost all of the automobiles in the world for alternator application. With the increase in power demands, the claw-pole machine is also being developed as a motor-generator utilized in the hybrid electric vehicles. At present the permanent magnet based claw-pole machine is being used in mild hybrid electric vehicles for energy savings. The literature is replete with various configurations of claw-pole machines that can be developed to achieve better performances. However, easy assembly and disassembly of various parts of the machine is also important for the reuse and recycle of magnets. In this research work two concepts have been developed; first, the direct reuse concept i.e. easy assembly/disassembly of the rotor and magnets, so as to easily take out the magnets for direct reuse or recycle and; second, the direct recycle concept i.e. utilization of recycled magnets in the machine to achieve the desired performance.In the course of this research the base design of the claw-pole machine was developed, analyzed and optimized so as to attain best torque versus magnet-weight ratio. This helped in the reduction of magnet cost for almost the same torque. The optimization was carried out using 3-D numerical analysis. The optimized model was developed in a way that the assembly process of the magnets and claw-poles remained the same. However, during disassembly the magnets can easily be withdrawn without disassembling the complete rotor; therefore utilizing these magnets for direct reuse in other applications or sent for recycling. In the direct recycle concept, the magnets used in the machine are recycled magnets with deteriorated performance. The type of recycling process is a strong determinant of the deterioration in performance of these recycled magnets. The aim of the direct recycle concept was to analyze the machine with virgin and recycled magnets, and evaluate the energy consumption of the machine under different drive cycles. It was observed that with utilization of recycled magnets in the claw-pole machine, the energy consumption was almost same as that of the machine with virgin magnets. Thus it can be concluded that for the permanent magnet based claw-pole machine, the utilization of recycled magnets is more sustainable for the environment as it can lead to consequential limits on the mining of rare earth materials. The price fluctuations and supply-demand problems can also be reduced with the increase in utilization of recycled magnets, albeit policy and norms are effectuated.The prototype of the machine with virgin magnets have been developed and tested for performance. It has been observed that the experimental results match fairly well with the design analysis results, hence validating the design process and methodology.
536

Electromagnetic Analysis of Hydroelectric Generators / Elektromagnetisk analys av vattenkraftgeneratorer

Ranlöf, Martin January 2011 (has links)
Hydropower maintains its position as the most important source of renewable electric energy in the world. The efficiency of large hydropower plants is unsurpassed, and after more than hundred years of development, the technology is mature and highly reliable. While new hydro resources are currently being developed in Asia and South America, most European countries go through a phase of intense refurbishment and upgrading of existing plants. Challenges faced by the hydropower industry include a knowledge transfer to new generations and the adaptation of unit designs to meet new operational requirements. As with all branches of engineering, the use of computerized design tools has revolutionized the art of hydropower plant design and the analysis of its performance. In the present work, modern tools like coupled field-circuit models and semi-analytic permeance models are used to address different aspects of electromagnetic analysis of generators in large hydropower plants. The results include the presentation of a mathematical model that uses concepts from rotating field theory to determine the air-gap flux density waveform in a hydroelectric generator. The model was succesfully used to evaluate armature voltage harmonics and damper bar currents at no-load and load conditions. A second study is concerned with the importance of losses due to rotational fields in core loss calculations. It is found that dynamic and rotational effects typically increase the total core loss estimates with about 28% in large hydroelectric generators. In a third study, linear models for the calculation of salient pole shoe form factors at an arbitrary level of magnetic loading are presented. The effect of the damper winding configuration on the damping capability of salient-pole generators is then evaluated in a separate study. The predicted impact of the coupling between damper cages on adjacent poles on the damping torque production is verified in a set of experiments.
537

MEMS-based phase-locked-loop clock conditioner

Pardo Gonzalez, Mauricio 02 April 2012 (has links)
Ultra narrow-band filters and the use of two loops in a cascade configuration dominate current clock conditioners based on phase-locked-loop (PLL) schemes. Since a PLL exhibits a low-pass transfer function with respect to the reference clock, the noise performance at very close-to-carrier offset frequencies is still determined by the input signal. Although better cleaning can be achieved with extremely narrow loops, an ultra low cut-off frequency could not be selected since the stability of the configuration deteriorates as the filter bandwidth is reduced. This fact suggests that a full-spectrum clock conditioning is not possible using traditional PLL architectures, and an alternative scheme is necessary to attenuate the very-close-to-carrier phase noise (PN). In addition, ultra-narrow loop filters can compromise on-chip integration because of the large size capacitors needed when chosen as passive. Input signal attenuation with relaxed bandwidth requirements becomes the main aspect that a comprehensive clock cleaner must address to effectively regenerate a reference signal. This dissertation describes the Band-Reject Nested-PLL (BRN-PLL) scheme, a modified PLL-based architecture that provides an effective signal cleaning procedure by introducing a notch in the input transfer function through inner and outer loops and a high-pass filter (HPF). This modified response attenuates the reference-signal PN and reduces the size of the loop-filter capacitors substantially. Ultra narrow loops are no longer required because the notch size is related to the system bandwidth. The associated transfer function for the constitutive blocks (phase detectors and local oscillators) show that the output close-to-carrier and far-from-carrier PN sections are mainly dominated by the noise from the inner-PLL phase detector (PD) and local oscillator (LO) located in the outer loop, respectively. The inner-PLL PD transfer function maintains a low-pass characteristic with a passband gain inversely proportional to the PD gain becoming the main contribution around the carrier signal. On the other hand, the PN around the transition frequency is determined mainly by the reference and the inner-PLL LO. Their noise contributions to the output will depend on the associated passband local maxima, which is located at the BRN-PLL transition frequency. Hence, in this region, the inner-PLL LO is selected so that its effect can be held below that of the outer-PLL PD. The BRN-PLL can use a high-Q MEMS-based VCO to further improve the transition region of the output PN profile and an LC-VCO as outer-PLL LO to reduce the noise floor of the output signal. In particular, two tuning mechanisms are explored for the MEMS-VCO: series tuning using varactors and phase shifting of a resonator operating in nonlinear regime. Both schemes are implemented to generate a tunable oscillator with no PN-performance degradation.
538

Les nouvelles méthodes de navigation durant le Moyen Age / New navigational Methods during the Middle Ages

Com'Nougue, Michel 29 November 2012 (has links)
Les nouvelles méthodes de navigation durant le Moyen Age. Le navire de commerce à voile est propulsé par le vent et doit donc suivre cette direction générale. La navigation peut se définir selon un aspect d’abord stratégique comme le choix d’une route en tenant compte des contraintes imposées par le vent et un aspect tactique concernant le tracé et le contrôle, en cours d’exécution de cette route. 1-Dans un premier temps, la navigation antique ne se réfère qu’au seul vent qui est le moteur mais aussi le guide du navigateur pour suivre la route fixée par l’observation des traces qu’il imprime sur la mer. C’est la navigation à vue. La limite de la méthode est atteinte quand le vent devient changeant au large, ce qui oblige alors une vérification de la direction par l’observation des astres. 2- L’apparition de l’aiguille aimantée résout en partie ce problème. L’orientation géographique entraine la mise au point, à la fin du XIIIe siècle, d’une nouvelle méthode : l’estime. L’estime est la résolution graphique des problèmes que pose le contrôle de la route choisie. Cette résolution suppose, d’une part, l’usage de la boussole et d’une orientation géographique et, d’autre part, une analyse vectorielle sur un support la carte marine qui est donc indissociable de la méthode. Le plus gros défaut de l’estime est que les positions sont définies par projection dans le futur de paramètres, cap et distances parcourues actuels. Des différences sont donc à prévoir qui entrainent une zone d’incertitude sur le point estimé. 3- Lorsqu’au début du XVe siècle les navigateurs se lancent dans l’inconnu, obligés de suivre le vent qui décrit des boucles, les voyages s’allongent sans voir la terre pour une confrontation avec des positions avérées. La taille des zones d’incertitude obligent le navigateur a préciser sa position finale par d’autres méthodes basées sur des observations astronomiques. On peut distinguer deux méthodes : Tout d’abord, la méthode des hauteurs de polaire, de 1433 à 1480 environ, qui permet de finaliser la volta et d’effectuer un atterrissage selon une route Est-Ouest. L’analyse de la technique nautique de Colomb, qui utilise cette méthode, est très semblable à celle décrite par Ibn Majid dans son traité de navigation. Il est probable qu’il y a eu transmission sans pouvoir préciser les circonstances exactes.Mais dès que les navigateurs franchissent l’équateur la polaire devient indisponible, les navigateurs doivent observer le soleil. Cette deuxième méthode est plus délicate car les paramètres du soleil changent chaque jour. Ils obligent donc le navigateur à calculer la latitude, à partir de l’observation de la méridienne de soleil et par l’usage de tables des données solaire : os regimentos do sol. C’est cette méthode qui permet à Vasco da Gama de doubler le cap de Bonne Esperance, en 1498, ce qui marque la fin de la période étudiée. Pour conclure il faut remarquer que ces deux derniers méthodes sont le fruit d’une coopération entre les usagers et les scientifiques sous l’égide du pouvoir, décidé à atteindre le but fixé. C’est donc le fruit d’une véritable recherche scientifique. En second lieu, il faut également noter que les progrès de la navigation accompagnent des progrès parallèles en architecture navale, le gouvernail d’étambot, ainsi que de nouvelles procédures dans le commerce maritime. L’étude des interactions entre ces divers domaines reste à faire. / New navigational methods during the Middle Ages.A sailing vessel is pushed forwards by the wind in the general direction towards it is blowing. Navigation should comply with strategic goals: i.e. the choice of a route to a port of destination, taking into account this wind constraint. A tactical aspect is involved when following this route and checking, the entire voyage long, the good guidance of the ship. 1-In the first ages of navigation, the mariner is referring to the sole element at his disposal: the wind. It gives him elements for the direction to choose, if it is a convenient time for sailing and also it supplies the means of checking and controlling the course of the ship, by observation of the marks it is printing on the surface of the sea. Variable wind is the limit of this method. In this case, only sky observation can give an indication of the direction to follow.2- The finding of the magnetic needle solves this problem and from this new tool, a new navigation method is implemented, around the end of the XIII.th century. Dead reckoning is a way to determinate ship’s position at any moment, using a vector analysis for solving graphically the problems that checking the chosen course can induce. This graphical method is using the compass indications and needs necessarily using a marine chart. The main problem of dead reckoning is that, using present data to reckon future positions , any error in assessing these data supposes an uncertainty in this position. Correction of the route is necessary by verifying with actual land falls. Longer the voyage without such confrontation and bigger the uncertainty zone to be faced.3-In the beginning of the XV.th century, Portuguese mariners started to run the open ocean. They had to follow the wind which runs along a long loop across the ocean, la volta. Therefore running in the open seas, without any land to be seen, in order to check the actual position, obliged mariners to elaborate new methods based on astronomical observations in order to reduce the size of this uncertainty zone, when arriving to the landing point. A first method is based on the observation of the pole star depth; between the years 1433 to 1480. It is based on observation of the pole star depth. Analysis of C. Columbus nautical art shows similarities with the written work of Ibn Majid, his contemporaneous Arab nautical expert. Crossing the equator line made the polar star not available any more. Therefore, the method had to be changed and the second method involved sun observations. This is more complex as the sun data are changing every day. Therefore mariners had to reckon the latitude, using the observations of the meridian line and using of sun data tables: the so called regimentos do sol. Through this method Vasco da Gama was able to reach the Indian Ocean after passing the Cape of Good Hope. This closes the period of this study.The conclusion should take into account the fact that these astronomical methods were not entirely empiric but the result of a joint research of users, mariners and scientists. This endeavor was made possible because a central power, the Infant first , then King Joao II, were willing to proceed more south and gave their mariners the technical means to do so.A second conclusion observes that progress of navigation were accompanied by parallels progresses in naval construction and maritime new contracts and ways of handling commercial matters. There are surely interactions between these three domains, but we have still to put them into evidence.
539

Studium interakcí iontů s molekulárním vodíkem v závislosti na jaderném spinu při teplotách relevantních pro astrochemii / Study of state selected interactions of ions with molecular hydrogen at temperatures relevant to astrochemistry

Zymak, Illia January 2013 (has links)
In this work are presented results of the experimental study of state selected reactions of H+ and N+(3PJa) ions with molecular hydrogen H2(J = 0, 1) at temperatures in the range 10 - 100 K using 22-pole rf ion trap apparatus. These reactions are important for the formation of interstellar trihydrogen cations and ammonia. To determine the temperature of ions, calibration measurements of the Doppler broadening of spectral lines using N2+ + Ar  Ar+ + N2 laser induced reaction and rate of the ternary association He+ + 2He  He2+ + He were performed. Both ternary and radiative channels of the H+ + H2(J) association reaction were observed at hydrogen number densities in the range 1012 - 1014 cm-3 and 1011 - 1012 cm-3 respectively. Obtained temperature dependences at 11 - 33 K demonstrate substantial role of the H2 rotational energy, results cannot be explained with the existed theories of the stabilization of collisional complexes. Measurements of the rate coefficient of N+(3PJa) + H2(J) reaction at different ortho fractions of H2 show dependence on internal energy of both reactants. State specific rate coefficients of the reaction of nitrogen and hydrogen ions were derived. The adiabatic model and collisional relaxations of N+(3PJa) fine structure levels were considered. Powered by TCPDF (www.tcpdf.org)
540

A Urbanização no litoral norte do estado do Rio Grande do Sul : contribuição para a gestão urbana ambiental do município de Capão da Canoa

Strohaecker, Tania Marques January 2007 (has links)
As relações entre sociedade e natureza ampliaram-se nas últimas décadas, devido, entre outros fatores, ao fenômeno de urbanização. No Litoral Norte do Estado do Rio Grande do Sul esse processo impulsionou a diversificação econômica e a ocorrência de problemas em um ambiente caracterizado por ecossistemas raros e de grande vulnerabilidade. Nesse sentido, a diretriz investigatória fundamenta-se na hipótese de que a urbanização é um vetor potencial de desenvolvimento sustentável para o Litoral Norte do Estado do Rio Grande do Sul. O trabalho objetiva a proposição de diretrizes e instrumentos de ação baseados no marco da sustentabilidade, para subsidiar políticas de desenvolvimento regional e urbano. A metodologia que norteou a pesquisa caracteriza-se pela análise das interações entre sociedade e natureza em duas escalas de abordagem, a regional e a local. Entre as conclusões do trabalho na escala regional, salienta-se que: a) as políticas de Estado, as emancipações, as migrações e o empreendedorismo são os principais condicionantes da urbanização; b) a região apresenta quatro perfis sócio-econômicos de municípios; c) a maior carência urbana ambiental é o saneamento básico; d) a diversidade sócio-ambiental do Litoral Norte constitui-se em importante elemento para o seu desenvolvimento e para a construção de uma identidade regional. Como contribuições originais destacam-se a elaboração de dois modelos gráficos sobre a dinâmica territorial e a proposição de diretrizes de caráter regional. Na escala local, analisa-se a dinâmica urbana ambiental do município de Capão da Canoa propondo-se estratégias e instrumentos de ação integrados às diretrizes regionais. Através da análise espacial identificaram-se três setores prioritários de intervenção: o saneamento básico, a preservação ambiental e cultural e o controle do uso e ocupação do solo. Constatou-se que a impermeabilização do solo, além de ampliar o escoamento superficial, provoca, entre outros fatores, o seccionamento do campo de dunas no pós-praia, comprometendo a qualidade sanitária da areia de praia e a balneabilidade das águas. As medidas propostas caracterizam-se pela multifuncionalidade, baixo custo de implantação e amplo alcance social. Entre as contribuições originais para a escala local propõe-se: a) bacias de amortecimento nos lotes (reservatórios) e nas áreas verdes (lagos) para minimizar os impactos do escoamento superficial em direção ao sistema praial; b) uma zona de proteção à costa com uma faixa mínima de não ocupação de 50 m de largura à retaguarda da praia (curto prazo) para diminuir os impactos decorrentes da energia de ondas e uma faixa de 150 m de largura (longo prazo) como prevenção a uma elevação do nível médio do mar nos próximos cem anos; c) a adoção de medidas preventivas e de controle do uso e ocupação do solo urbano, através de instrumentos urbanísticos previstos no Estatuto da Cidade. Conclui-se que a decisão política para a adoção ou não das medidas e ações aqui explicitadas depende essencialmente de mudanças culturais. O engajamento do poder público, da sociedade civil e de suas instituições é fator decisivo para a transformação do Litoral Norte do Estado do Rio Grande do Sul em um Pólo de Sustentabilidade Ambiental. / The relationships between society and nature have broadened in the last decades, owed, among other factors, to the phenomenon of urbanization. In the Northern Coast of Rio Grande do Sul this process drove the economical diversification and the incident of problems in rare ecosystems and of great vulnerability. In this sense, the main inquirenment is based on the hypothesis that urbanization is a potential vector of sustainable development for the Northern Coast of Rio Grande do Sul. The aim of this work is the proposition of directives and instruments of action based on the sustentability landmark, to subsidize politics of regional and urban development. The methodology that has orientated this research is characterized for the analysis of the interactions between society and nature in two scales of approach, the regional and the local. Among the conclusions of the work in the regional scale which include 21 municipalities, could be pointed out that: a) the politics of State, the emancipations, the migrations and the entrepeneurship are the principal factors of the urbanization process; b) the region presents four municipal socioeconomic profiles; c) the biggest urban environmental lack is the basic sanitation; d) the environmental social diversity of the Northern Coast sets itself up as important element for his development and for the construction of a regional identity. The production of two graphic models on the territorial dynamic and the proposition of directives of regional character stand out as original contributions. Three priority sectors of intervention were identified through the spacial analysis in the local scale (Capão da Canoa municipality): the basic sanitation, the environmental and cultural preservation and the control of the use and occupation of the land. It was noticed that the soil impermeabilization, besides enlarging the superficial drainage leads, among other factors, cause the seccionment of the dune fields in backshore, compromising the sanitary quality of the beach sand and the balneability of the water. The proposed measures are characterized by multifunctionality, implantation low cost and spacious social search. Among the original contributions for the urban scale could be proposed: a) basins of deadening in the shares (reservoirs) and in the green areas (lakes) to minimize the impacts of the superficial drainage towards the beach system; b) a protection zone to the coast with a least bealt of not occupation of 50 m of width to the rearguard of the beach (short term) to reduce the impacts resulting from the waves energy and a belt of 150 m of width (long term) as prevention to an elevation of the medial sea level in the next one hundred years; c) the adoption of preventive measures and of the use control and occupation of the urban land, through urbanistic instruments predicted in the City Statute. Through the methodology and the development of the work and his objectives in the regional and local scales, was possible to confirm the initially formulated hypothesis. The conclusion is that the political decision for the adoption or not of the measures and actions here set out depends essentially on cultural changes. The commitment of the public power, of the civil society and of his institutions is a decisive factor to transform the Northern Coast of Rio Grande do Sul in an Environmental Sustentability Pole.

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