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Control strategies for offshore wind farms based on PMSG wind turbines and HVdc connection with uncontrolled rectifierRodríguez D'Derlée, Johel José 16 December 2013 (has links)
The selection of the bulk power transmission technology in offshore wind
farms is strongly related to the wind farm size and its distance to shore.
Several alternatives can be evaluated depending on the rated power of the
offshore wind farm, the transmission losses and the investment cost for
constructing the transmission system. However, when is necessary to
connect larger and more distant offshore wind farms; the best
technological solution tends to the transmission system based on highvoltage
and direct-current with line commutated converters (LCC-HVdc).
This dissertation proposes the use of diode-based rectifers as a technical
alternative to replace the thyristor-based rectifers in an LCC-HVdc link with
unidirectional power flow. This alternative shows advantages with regard
to lower conduction losses, lower installation costs and higher reliability.
Nonetheless, as a counterpart the offshore ac-grid control performed by
the thyristor-based HVdc rectifer is no longer available. This lack of control
is compensated by using new control strategies over an offshore wind
farm composed by wind turbines with permanent-magnet generators and
fully-rated converters. The control strategies have been based mainly on
the ability of the wind turbine grid-side converter to perform the control of
the offshore ac-grid voltage and frequency. The performance has been
evaluated by using PSCAD. Wherein, the most common grid disturbances
have been used to demonstrate the fault-ride-through capability as well as
the adequate steady state and transient response. / Rodríguez D'derlée, JJ. (2013). Control strategies for offshore wind farms based on PMSG wind turbines and HVdc connection with uncontrolled rectifier [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/34510 / TESIS
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"IO PER ME SONO UN'OMBRA". GIOVAN BATTISTA STROZZI IL GIOVANE (1551 - 1634) FRA POESIA E RIFLESSIONE LETTERARIAROSSINI, FRANCESCO 12 April 2019 (has links)
La tesi propone uno studio monografico sul fiorentino Giovan Battista Strozzi il Giovane detto il Cieco (1551-1634), letterato e animatore di circoli culturali dalla Firenze medicea alla Roma barberiniana, attraverso la Milano borromaica e i cenacoli capitolini degli Aldobrandini e degli Umoristi. Nel primo dei tre capitoli che scandiscono la ricerca si è appuntata l’attenzione sulla partecipazione del Giovane alle attività di due vivaci consessi della sua città natale: l’Accademia Fiorentina e l’Accademia degli Alterati. Nel secondo è stata condotta una disamina dell’opera in versi – per la maggior parte ancora inedita – che comprende decine di epistole metriche in endecasillabi sciolti, un incompiuto poema in onore di Amerigo Vespucci, nonché un ricco corpus di madrigali, la cui stesura, nell’esperienza del Cieco, procedette di conserva con la speculazione teorica intorno alla nuova fisionomia cinquecentesca di questo antico genere lirico. La terza sezione si concentra invece sul contributo dello Strozzi alle discussioni di poetica (la ‘Commedia’ dantesca, il poema eroico, le unità aristoteliche) che accesero gli ambienti letterari italiani nella seconda metà del secolo XVI. Affiancando l’esegesi dei testi alla ricostruzione biografica – condotta su un ampio numero di documenti epistolari editi e inediti –, si è cercato di restituire il giusto spessore storico a ciascuno degli scritti presi in esame, ricostruendo i differenti contesti culturali in cui furono composti e scandagliando la fitta trama di relazioni – umane e letterarie – che si profila sullo sfondo di essi. Completano il lavoro una bibliografia delle opere antiche e moderne, un indice dei manoscritti e un indice dei nomi di persona. / The thesis proposes a monographic study on the Florentine Giovan Battista Strozzi the Younger also known as the Blind (1551-1634). He was a writer with connections in cultural circles across Renaissance Italy, including Medici’s Florence, Barberini’s Rome, Borromean Milan and the Roman cenacles of the Aldobrandini and the Humorists. The thesis consists of three chapters. The first chapter focuses on the participation of Strozzi the Younger in the activities of two lively groups in his hometown: the Florentine Academy and the Alterati Academy. The second chapter discusses his poetical works – for the most part still unpublished –, including dozens of versified epistles in loose hendecasyllables, an unfinished poem in honor of Amerigo Vespucci, as well as a rich corpus of madrigals. The drafting of this last corpus proceeded together with Strozzi the Younger’s theoretical speculation around the new sixteenth-century appearance of this ancient lyrical genre. The third section considers the contribution of Strozzi the Younger to the discussions on poetics (Dante’s ‘Comedy’, the heroic poem, the Aristotelian units) that went on in Italian literary circles in the second half of the sixteenth century. In this work, we aimed to restore the appropriate historical depth to each of the writings examined, through the exegesis of texts combined with the biographical reconstruction conducted on a large number of published and unpublished epistolary documents. We also tried to reconstruct the different cultural contexts in which these writings were composed and attempted to analyze the dense network of relationships, both human and literary, that loomed in the background. The thesis is completed by a bibliography of ancient and modern works, an index of manuscripts and an index of names.
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Sulphate‐reducing bacterial diversity in a calcareous sandy sediment of Mallorca and community response to hydrocarbon contaminationSuárez Suárez, Ana Belén 25 July 2012 (has links)
Aquesta tesi tracta sobre l'efecte de la contaminació per cru de petroli sobre
l'ecosistema costaner mediterrani i sobre el paper fonamental dels sediments marins
en la regulació i el manteniment dels processos biogeoquímics. L'estudi presta especial
atenció a les comunitats bacterianes reductores de sulfat i la seva implicació en la
degradació de contaminants orgànics. La diversitat, abundància i fisiologia dels bacteris
reductors de sulfat que habiten el sediment arenós del nord de Mallorca (Illes Balears),
van ser analitzades mitjançant un enfocament polifàsic, basat en la combinació
d'experiments in situ i in vitro, biologia molecular clàssica i d’última generació, cultius i
determinació d'activitats metabòliques. Els resultats obtinguts durant aquesta tesi
demostren que el sediment mediterrani alberga una microbiota autòctona que podria
prosperar després d'un vessament de cru de petroli i el paper de la qual podria ser
crucial per a la transformació i l'eliminació de compostos orgànics xenobiòtics en
aquest ambient. / Esta tesis trata sobre el efecto de la contaminación por crudo de petróleo en el
ecosistema costero mediterráneo y sobre el papel fundamental de los sedimentos
marinos en la regulación y el mantenimiento de los procesos biogeoquímicos. El
estudio presta especial atención a las comunidades bacterianas reductoras de sulfato y
a su implicación en la degradación de contaminantes orgánicos. La diversidad,
abundancia y fisiología de las bacterias reductoras de sulfato que habitan el sedimento arenoso del norte de Mallorca (Islas Baleares), fueron analizadas mediante un enfoque
polifásico, basado en la combinación de experimentos in situ e in vitro, biología
molecular clásica y de última generación, cultivos y determinación de actividades
metabólicas. Los resultados obtenidos durante esta tesis demuestran que el sedimento
mediterráneo alberga una microbiota autóctona que podría prosperar después de un
derrame de crudo de petróleo y cuyo papel podría ser crucial para la transformación y
la eliminación de compuestos orgánicos xenobióticos en este ambiente. / This thesis discusses the fate and behave of crude oil contamination in the
Mediterranean coastal ecosystem, and the essential role of the marine sediments in
the regulation and maintenance of biogeochemical processes. The study pays
particular attention to the role of sulphate reducing bacterial communities in the
degradation of organic matter and pollutants entering the Mediterranean
environment. A polyphasic approach based in the combination of in situ and in vitro
experiments, next generation and classical molecular biology, cultivation, and the
determination of metabolic activities, provided first insights into the diversity, abundance and physiology of sulphate reducing bacteria inhabiting the undisturbed
sandy sediment at the north of Mallorca (Balearic Islands). The results obtained during
the thesis demonstrate that the undisturbed Mediterranean sediment harbours an
autochthonous microbiota that could prosper after a crude oil spill and which role
might be crucial for the transformation and removal of hazardous organic compounds
in this environment.
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Parcs nationaux en transition vers des parcs nationaux naturels anthropisés (PNNa) ? Étude comparative de trois parcs nationaux naturels habités du Continent américain (Colombie, Guyane française, Québec). / National parks in transition towards "nature and anthropic national parks" (PNNa)? Comparative study of three inhabited natural national parks of the American continent : the example of Quebecker, Guyanese and Colombian Cases. / ¿Parques nacionales naturales en transicion hacias parques nationales naturales antropicos (PNNa)? Estudio comparativo de tres parques nacionales naturales habitados del contiente americano : ejemplo de los casos Quebenquense, Guyanes y Colombanio.Sierra Jimenez, Mara Johanna 27 May 2016 (has links)
L’évolution des politiques de gouvernance environnementale internationale et la transition des contextes nationaux et locaux de conservation favorisent de plus en plus l’intégration de la dimension anthropique au sein des parcs nationaux (catégorie II-UICN). Cette dimension s’adresse d’une part aux populations locales qui habitent de manière permanente les diverses zones de protection, et d’autre part, aux acteurs économiques (légaux et illégaux) qui exploitent le territoire protégé (tourisme, orpaillage, bois, etc.) ou qui participent de manière directe et indirecte aux processus de construction territoriale du parc national. L’intégration de la dimension anthropique au sein de ces territoires naturels de protection favorise en conséquence l’émergence de nouvelles dynamiques et stratégies de gestion et de gouvernance participatives.Avec une triple approche scientifique construite autour des regards croisés de la géographie politique, de la géographie socioculturelle et de la political ecology, cette thèse s’intéresse à l’analyse de trois cas d’études particuliers du continent américain afin de comprendre comment l’intégration de cette dimension anthropique (socioculturelle et économique) favorise la transition de certains espaces naturels protégés classiques vers une nouvelle configuration que nous proposons d’identifier ici sous le nom de « parcs nationaux naturels anthropisés - PNNa ». L’analyse systémique de la structure et du fonctionnement des macrostructures de gouvernance et des microstructures de gestion du Parc amazonien de la Guyane en France, du Parc marin du Saguenay-Saint-Laurent au Québec (Canada) et du Parc national naturel Amacayacu en Amazonie colombienne, nous ont permis ainsi de mettre en évidence quelques aspects de cette transition dans la gestion territoriale des espaces naturels protégés de catégorie II, ainsi que les conflits de pouvoir qui en résultent. / The evolution of international environmental policies and national and local conservation contexts gives increasing importance to the anthropic dimension within the national parks (category II UICN). Not only does this dimension takes into account the local population that lives permanently in these various natural areas, but also the economic actors who, legally or illegally, benefit from those protected areas (tourism, gold-washing, wood, etc.) or participate directly or indirectly in the process of the territorial elaboration of a national park. The integration of the anthropic aspect definitely help the emergence of new dynamics and strategies of collaborative management and policies. Building on political geography, socio-cultural geography and political ecology, this thesis aims to shed light how that anthropic dimension (sociocultural as well as economical) entails the transition of some protected areas from a classical type to a new category we identify as the “Nature and Anthropic National Park” (PNNa). We focus on three specific study cases in the American continent: the Amazonian park of the French Guiana, the Sea Park of Saguenay-Saint-Laurent of Québec, Canada, and the Amazonian Amacayacu National Park of Colombia. The systemic analysis of their structure and their functioning, as far as macrostructure of policies and microstructures of management are concerned, has allowed us to bring out that transition in the territorial management of these category II protected natural areas and the deriving conflicts for power. / La evolución de las políticas de gobernanza medioambiental internacional y la transición de los contextos nacionales y locales de conservación, favorecen cada vez más la integración de la dimensión antrópica al interior de los parques nacionales (categoría II-UICN). Esta dimensión corresponde de una parte, a las poblaciones locales que habitan de manera permanente las diversas zonas de protección dentro del parque nacional, y de otra parte, a los actores económicos (legales e ilegales) que explotan el territorio protegido (Turismo, explotación minera, explotación de madera, etc), o que participan de manera directa o indirecta en los procesos de construcción territorial del parque nacional. La integración de la dimensión antrópica dentro de estos territorios naturales de protección favorece en consecuencia la emergencia de nuevas dinámicas y estrategias participativas de gestión y de gobernanza. A través de un triple enfoque científico construido mediante el cruce de diversos puntos de vista de la geografía política, de la geografía sociocultural y de la political ecology, esta tesis se interesa en el análisis de tres casos de estudio particulares del Continente americano. El objetivo de esta contribución es el de intentar mostrar, cómo la integración de la dimensión antrópica (sociocultural y económica) influencia la transición de algunos espacios naturales protegidos hacia una nueva configuración que nosotros proponemos identificar aquí bajo el nombre de “parques nacionales naturales antropizados – PNNa”.El análisis sistémico de la estructura y del funcionamiento de las macroestructuras de gobernanza y de las microestructuras de gestión participativa del Parque amazónico de la Guayana, en Francia, del Parque marino del Saguenay-Saint-Laurent en Quebec, Canadá, y del Parque nacional natural Amacayacu en Amazonia colombiana, nos permitieron poner en evidencia este tipo de transición en la gestión territorial de los espacios naturales protegidos de categoría II, así que los conflictos de poder que resultan de esta transformación.
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