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Aquesta tesi es centra en la preparació de noves membranes polimèriques per a fotosíntesi artificial. Hem preparat i caracteritzat dos materials diferents, basats en Poli(epicloridina-co-òxid d’etilé) (PECH-co-EO), modificada amb metil 3,4,5-tris[4-(n-dodecan-1-iloxi)benziloxi]benzoat, al 20% (CP20) o 40% (CP40), respectivament. Per assolir propietats de transport eficients, es prepararen membranes orientades homeotròpicament mitjançant un tractament tèrmic. Seguidament, es van analitzar mitjançant anàlisi tèrmic dinàmo-mecànic (DMTA) i dièlectric (DETA). DETA i DMTA van confirmar que la presència del dendró dificulta el moviment dels copolímers; tanmateix, les membranes orientades i no orientades no mostraren una gran diferència, independentment de la quantitat del dendró. A més, vam estudiar les propietats de transport mitjançant proves de permeabilitat de protó i methanol i de voltametria d’escombrat lineal (LSV). Els resultats demostraren que tant en CP20 com en CP40, el transport de cations depèn de la presència de canals de transport definits, no afectats per la presència d’aigua; els experiments LSV realitzats amb diferents cations van demostrar que CP40 posseeix canals amb diàmetres més grans, i que les seves estructures internes són millor definides. D'altra banda, vam intentar millorar el rendiment en absorció de CO2 mitjançant l'ús de membranes de polisulfona amb dos additius diferents en contactors de membrana gas-líquid. Aquests additius estan basats en una polietilenimina comercial hiperramificada (LupasolG20), parcialment modificada amb clorur de benzoil (mG20) o fenilisocianat (UG20). Es prepararen membranes amb diferents quantitats d'additius per precipitació per inversió de fase i es caracteritzaren mitjançant diverses tècniques. Vam trobar que la presència de l'additiu millora molt les característiques de les membranes quant a captura de CO2, especialment la solubilitat, hidrofobicitat i resistència química a la solució aquosa alcalina absorbent, donant els millors resultats per al 5% d'additiu. La permeabilitat i absorció de CO2 van millorar amb tots dos additius, mostrant UG20 un millor rendiment. Esta tesis se centra en la preparación de nuevas membranas poliméricas para dispositivos de fotosíntesis artificial. Preparamos y caracterizamos dos materiales diferentes,basados en Poli(epiclorhidrina-co-óxido de etileno) injertados con 3,4,5-tris[4-(n-dodecan-1-iloxi)benciloxi] benzoato, en un 20% (CP20) o 40%(CP40), respectivamente.Para alcanzar unas propiedades de transporte eficientes, se prepararon membranas orientadas homeotrópicamente mediante un tratamiento térmico controlado y posteriormente se investigaron mediante análisis térmico dinamo-mecánico (DMTA) y análisis térmico dieléctrico (DETA).DMTA y DETA confirmaron que la injerción del dendrón dificulta seriamente los movimientos del copolímero, pero no mostraron grandes diferencias entre las membranas orientadas y las no orientadas, independientemente de la cantidad de dendrones. Además, las propiedades de transporte se estudiaron mediante experimentos de permeabilidad de protones y metanol y mediante voltamperometría de barrido lineal (LSV). Los resultados demostraron que en CP20 y CP40, el transporte de cationes dependía de la presencia de canales catiónicos definidos, no afectados por la presencia de agua;la comparación entre experimentos LSV realizados con diferentes cationes alcalinos sugiere que CP40 posee canales con diámetros más grandes y estructuras internas mejor definidas. Por otro lado, intentamos mejorar el rendimiento en absorción de CO2 mediante el uso de membranas de polisulfona con dos aditivos diferentes en contactores de membrana gas-líquido. Estos aditivos están basados en una polietilenimina commercial hiperramificada (LupasolG20) parcialmente modificada con cloruro de benzoílo (mG20) o fenilisocianato(UG20).Se prepararon membranas con diferentes cantidades de aditivos por precipitación por inversión de fase y se caracterizaron mediante varias técnicas.Se encontró que la presencia del aditivo mejoró mucho las características de las membranas en cuanto a captura de CO2, especialmente la solubilidad, hidrofobicidad y resistencia química a la solución acuosa alcalina absorbente, dando los mejores resultados para 5% de aditivo.El rendimiento de las membranas en términos de permeabilidad y absorción de CO2 mejoró con ambos aditivos, mostrando UG20 un mejor rendimiento. This doctoral thesis focuses on preparing novel polymeric membranes to be used in artificial photosynthesis devices. In particular, we are interested in membranes for both ion conductive and CO2 capture. We prepared and characterized two different materials, based on Poly(epichlorohydrin-co-ethylene oxide) (PECH-co-EO) grafted with potassium 3,4,5-tris[4-(n-dodecan-1-yloxy)benzyloxy] benzoate, containing 20% (CP20) or 40% (CP40) modified units, respectively. In order to reach efficient transport properties, homeotropically oriented membranes were prepared by a fine-tuned thermal annealing treatment and were subsequently investigated by dynamic mechanical thermal analysis (DMTA) and dielectric thermal analysis (DETA). DMTA and DETA confirmed that grafting with the dendron strongly hinders copolymer motions, but did not show great differences between unoriented and oriented membranes, regardless of the amount of dendrons. Moreover, transport properties were studied by methanol and proton conductivity experiment and by linear sweep voltammetry (LSV). Results demonstrated that in CP20 and CP40, cation transport depends on the presence of defined cationic channels, not affected by water presence; the comparison between LSV experiments performed with different alkaline cations suggests that CP40 possesses channels with larger diameters and better-defined inner structures. We focused on improving CO2 absorption performance by using two different additives in neat polysulfone as gas-liquid membrane contactors. These additives are amine additives based on hyperbranched Lupasol G20 partially grafted with benzoyl chloride (mG20) or phenyl isocyanate (UG20). Membranes with different amount of additives were prepared by phase inversion precipitation and characterized by several techniques. In general, it was found that the presence of the additive greatly improved the characteristics of the membranes as regards the CO2 capture, especially solubility, hydrophobicity and chemical resistance to the aqueous alkaline absorbent solution, giving the better results for 5% additive content. In summary, the performance of blend membranes in terms of CO2 permeability and absorption was improved by both additives, while UG20 demonstrates better performance compared to mG20.

The emergence of GaN devices have brought new challenges within power electronics especially consumer electronics since the voltage rating has not become as high as silicon carbide. This new emergence resulted in an increase in switching frequency capability of power electronics circuits and may be used to increase the efficiency of current topologies, decrease the profile, and cost of the total circuit. Since most important and expensive part of each SMPS is its inductor, the increase in switching frequency will result in a significant decrease in passive component size and potentially the total price of the circuit. Nowadays most people carry laptops, cellphones and in general a lot of handheld devices and all of them need charging. Previously, every single device has its own specific charger and as a result, you had to bring multiple cords and chargers to make sure you do not run out of battery. With the development of USB-C, the era of multiple chargers has ended. Instead, a single cable and a single high capacity charger or power bank is sufficient to carry through each day without running out of battery. This thesis will investigate a 60watt USB-C charger with power delivery to fast charge every USB-C compatible device. The objective is to modify an existing topology which has the least number of components and make it as efficient, small, and cost effective as possible.

Light-field (LF) 3D displays are anticipated to be the next-generation 3D displays by providing smooth motion parallax, wide field of view (FOV), and higher depth range than the current autostereoscopic displays. The projection-based multi-view LF 3D displays bring the desired new functionalities through a set of projection engines creating light sources for the continuous light field to be created. Such displays require a high number of perspective views as an input to fully exploit the visualization capabilities and viewing angle provided by the LF technology. Delivering, processing and de/compressing this amount of views pose big technical challenges. However, when processing light fields in a distributed system, access patterns in ray space are quite regular, some processing nodes do not need all views, moreover the necessary views are used only partially. This trait could be exploited by partial decoding of pictures to help providing less complex and thus real-time operation. However, none of the recent video coding standards (e.g., Advanced Video Coding (AVC)/H.264 and High Efficiency Video Coding (HEVC)/H.265 standards) provides partial decoding of video pictures. Such feature can be achieved by partitioning video pictures into partitions that can be processed independently at the cost of lowering the compression efficiency. Examples of such partitioning features introduced by the modern video coding standards include slices and tiles, which enable random access into the video bitstreams with a specific granularity. In addition, some extra requirements have to be imposed on the standard partitioning tools in order to be applicable in the context of partial decoding. This leads to partitions called self-contained which refers to isolated or independently decodable regions in the video pictures. This work studies the problem of creating self-contained partitions in the conventional AVC/H.264 and HEVC/H.265 standards, and HEVC 3D extensions including multi-view (i.e., MV-HEVC) and 3D (i.e., 3D-HEVC) extensions using slices and tiles, respectively. The requirements that need to be fulfilled in order to build self-contained partitions are described, and an encoder-side solution is proposed. Further, the work examines how slicing/tiling can be used to facilitate random access into the video bitstreams, how the number of slices/tiles affects the compression ratio considering different prediction structures, and how much effect partial decoding has on decoding time. Overall, the experimental results indicate that the finer the partitioning is, the higher the compression loss occurs. The usage of self-contained partitions makes the decoding operation very efficient and less complex.

Light field 3D displays represent a major step forward in visual realism, providing glasses-free spatial vision of real or virtual scenes. Applications that capture and process live imagery have to process data captured by potentially tens to hundreds of cameras and control tens to hundreds of projection engines making up the human perceivable 3D light field using a distributed processing system. The associated massive data processing is difficult to scale beyond a specific number and resolution of images, limited by the capabilities of the individual computing nodes. The authors therefore analyze the bottlenecks and data flow of the light field conversion process and identify possibilities to introduce better scalability. Based on this analysis they propose two different architectures for distributed light field processing. To avoid using uncompressed video data all along the processing chain, the authors also analyze how the operation of the proposed architectures can be supported by existing image/video codecs. publishedVersion