Experimental testing of a wake ingesting propeller

The aviation industry is rapidly changing, lead by a growing demand on more modern aircrafts who are able to address the future challenges in terms of fuel consumption, effciency and green emissions among other factors. In order to correctly address these challenges, new technologies and non-conventional designs are being investigated upon. One of the phenomena which could be taken advantage of is the Boundary Layer Ingestion (BLI). Such phenomena take place whenever the propulsive system ingests an air ow which has been modified from the freestream conditions, either containing boundary layer ow from near aircraft features, or the more developed wake of a body. The aim of this paper is to gain a deeper insight on the parameters governing such phenomena. For such purpose, an experimental parametric study of a propeller performance ingesting the wake of three spheres at three different distances between them will be carried out on a closed loop wind tunnel. Results show that the distance between the propulsive unit and the bodies does not produce performance differences on the advance ratios range considered. However, the sphere size does produce changes on the system performance, either by increasing the produced thrust, or by decreasing the consumed power. The performance improvement mechanism is observed to depend on the sphere non dimensionalised size with the propeller diameter. For smaller spheres, a power reduction is observed, while for bigger ones thrust enhancement is produced.Ingeniería Aeroespacial (Plan 2010

The Politics of Mexican Documentary Distribution: Three Case Studies, 1988-2006

This dissertation examines the politics involved in the distribution of Mexican documentaries during the 1988-2006 period, as a way to pinpoint the factors shaping the circulation of these films. The research explores inequalities in audiovisual distribution, which have affected the circulation of Mexican documentaries in the domestic market. In my argument, I sustain that these inequalities are the result of complex political and economic tensions within the field of cultural production in a country that has entered an era of neoliberalism and transitional democracy. To narrow the scope of this study to feasible and attainable proportions, I analyze three distribution case studies applying a cultural industries approach within critical political economy, informed by Pierre Bourdieu's field theory and concepts borrowed from cultural studies. The case studies under analysis involved the documentary production and distribution of three production houses. Each of them participates in a different field of cultural production: film, video, or television. These production houses are the film company La Media Luna, the video collective Canal 6 de Julio, and the publishing and video company Clío. By examining these case studies, I highlight what is at stake when some audiovisual texts have greater access to audiences and markets than others. This is important since documentaries have helped to ensure a diversity of voices, both social and political, in the Mexican public sphere. In order to ensure this diversity, it is crucial to understand how Mexican documentaries can gain access to larger Mexican audiences. This is what this dissertation seeks to address

Unbalanced Current Static Compensator

The objective of this thesis is to present and evaluate a solution to the unbalanced current issue that can be found in three-phase electrical power grids. The solution is named unbalanced current static compensator (UCSC) and has the goal of balancing the currents at the source in order to mitigate adverse issues such as of negative- and zero-sequence currents that are generated by three-phase current unbalances. The solution topology consists of three single-phase H-bridge converters that are controlled through an algorithm working in the d-q frame of reference. The algorithm is divided in three different stages: the phase synchronization and reference current generator stage, the DC-link voltage and current controller stage, and the PWM stage. The design and functionality of the UCSC topology and algorithm is validated through MATLAB/SIMULINKTM simulations

Physical principles of memory and logic devices based on nanostructured Dirac materials

During the las decades, the silicon-based semiconductor industry has enabled higher performance per cost of integrated circuits due to the ability of nearly doubling the amount of transistors per chip every two years, however, this has resulted in overheating issues and fundamental manufacturing problems that are very di¿cult to solve. Therefore, Dirac materials (DMs), such as graphene and topological insulators (TIs), are being extensively investigated as possible candidates for replacing silicon-channel devices in the next-generation integrated circuits, due to their attractive ultrahigh carrier mobility and possibility of quantum e¿ects that may be useful for electronic applications. This requires to study the physical principles of such nanostructures to e¿ectivelypredictthequantumtransportbehaviorofpossibledevices. Theaimofthis work is to explore the physical properties of Dirac material-based nanostructures that could be used for novel memory and logic devices, by using tight-binding (TB) and density function theory (DFT) methods combined with the non-equilibrium function (NEGF) formulationDoctoradoDOCTOR(A) EN INGENIERÍA ELECTRICA Y ELECTRÓNIC

La reserva de dominio mobiliaria en el concurso del comprador: Comentario a la Sentencia núm. 592/2007, de 19 de diciembre

Para la Sentencia no procede que el vendedor de unos bienes muebles, que se ha reservado el dominio, ejercite el derecho de separación de los mismos en el concurso del comprador. Asimismo tampoco estima la resolución de dichos contratos por incumplimiento del comprador, pues una vez entregados los bienes, no queda ninguna prestación pendiente por parte del vendedor y eso impediría la aplicación de la facultad resolutoria, según los arts. 61 y 62 LC. Frente a esas ideas, se argumenta en el comentario sobre la base del art. 56 LC, ni siquiera citado en los FD. De dicho precepto entendemos que derivaría la solución contraria: la procedencia de la resolución de los contratos de compraventa por falta de pago del comprador, y la consiguiente recuperación de los bienes objeto de la compraventa por el vendedor.Secretaría de Estado de Universidades DER2008-0430

Mejora presunta por donación: su exclusión del sistema de nuestro código: Comentario a la Sentencia del Tribunal Supremo de 29 de mayo de 2006 (RJ 2006, 3343)

Al hilo del caso enjuiciado en la sentencia comentada, se plantea el margen de admisibilidad de mejoras tácitas en el Código Civil por vía de donación que exceda de la legítima del donatario y de la parte de libre disposición. Frente a la doctrina que postula una interpretación casi abrogatoria del artículo 825 del Código Civil, se sostiene la necesidad de respetar su tenor literal, cuya finalidad es precisamente dispensar tratamiento diferente a las liberalidades efectuadas en vida frente a aquellas efectuadas en testamento. Como demuestran con excepcional nitidez sus antecedentes, la ratio del precepto es precisamente establecer esa radical diferencia entre ambas categorías de atribuciones