Self-consistency in non-extensive thermodynamics of highly excited hadronic states

The self-consistency of a thermodynamical theory for hadronic systems based on the non-extensive statistics is investigated. We show that it is possible to obtain a self-consistent theory according to the asymptotic bootstrap principle if the mass spectrum and the energy density increase q-exponentially. A direct consequence is the existence of a limiting effective temperature for the hadronic system. We show that this result is in agreement with experiments. (C) 2012 Elsevier B.V. All rights reserved.

Co-simulazione e co-progetto non lineare/elettromagnetico di sistemi wireless non convenzionali

L’attività di ricerca contenuta in questa tesi si è concentrata nello sviluppo e nell’implementazione di tecniche per la co-simulazione e il co-progetto non lineare/elettromagnetico di sistemi wireless non convenzionali. Questo lavoro presenta un metodo rigoroso per considerare le interazioni tra due sistemi posti sia in condizioni di campo vicino che in condizioni di campo lontano. In sostanza, gli effetti del sistema trasmittente sono rappresentati da un generatore equivalente di Norton posto in parallelo all’antenna del sistema ricevente, calcolato per mezzo del teorema di reciprocità e del teorema di equivalenza. La correttezza del metodo è stata verificata per mezzo di simulazioni e misure, concordi tra loro. La stessa teoria, ampliata con l’introduzione degli effetti di scattering, è stata usata per valutare una condizione analoga, dove l’elemento trasmittente coincide con quello ricevente (DIE) contenuto all’interno di una struttura metallica (package). I risultati sono stati confrontati con i medesimi ottenibili tramite tecniche FEM e FDTD/FIT, che richiedono tempi di simulazione maggiori di un ordine di grandezza. Grazie ai metodi di co-simulazione non lineari/EM sopra esposti, è stato progettato e verificato un sistema di localizzazione e identificazione di oggetti taggati posti in ambiente indoor. Questo è stato ottenuto dotando il sistema di lettura, denominato RID (Remotely Identify and Detect), di funzioni di scansione angolare e della tecnica di RADAR mono-pulse. Il sistema sperimentale, creato con dispositivi low cost, opera a 2.5 GHz ed ha le dimensioni paragonabili ad un normale PDA. E’ stato sperimentata la capacità del RID di localizzare, in scenari indoor, oggetti statici e in movimento.

First principle study of ions in water and ionic liquids

Die beiden in dieser Arbeit betrachteten Systeme, wässrige Lösungen von Ionen und ionische Flüssigkeiten, zeigen vielfältige Eigenschaften und Anwendungsmöglichkeiten, im Gegensatz zu anderen Systemen. Man findet sie beinahe überall im normalen Leben (Wasser), oder ihre Bedeutung wächst (ioinische Flüssigkeiten). Der elektronische Anteil und der atomare Anteil wurden getrennt voneinander untersucht und im Zusammenhang analysiert. Mittels dieser Methode konnten die in dem jeweiligen System auftretenden Mechanismen genauer untersucht werden. Diese Methode wird "Multiscale Modeling" genannt, dabei werden die Untereinheiten eines Systems genauer betrachtet, wie in diesem Fall die elektronischen and atomaren Teilsystem. Die Ergebnisse, die aus den jeweiligen Betrachtungen hervorgehen, zeigen, dass, im Falle von hydratisierten Ionen die Wasser-Wasser Wechselwirkungen wesentlich stärker sind als die elektrostatischen Wechselwirkung zwischen Wasser und dem Ion. Anhand der Ergebnisse ergibt sich, dass normale nicht-polarisierbare Modelle ausreichen, um Ionen-Wasser Lösungen zu beschreiben. Im Falle der ionischen Flüssigkeiten betrachten wir die elektronische Ebene mittels sehr genauer post-Hartree-Fock Methoden und DFT, deren Ergebnisse dann mit denen auf molekularer Ebene (mithilfe von CPMD/klassischer MD) in Beziehung gesetzt werden. Die bisherigen Ergebnisse zeigen, dass die Wasserstoff-Brückenbindungen im Fall der ionischen Flüssigkeiten nicht vernachässigt werden können. Weiterhin hat diese Studie herausgefunden, dass die klassischen Kraftfelder die Elektrostatik (Dipol- und Quadrupolmomente) nicht genau genug beschreibt. Die Kombination des mikroskopischen Mechanismus und der molekularen Eigenschaften ist besonders sinnvoll um verschiedene Anhaltspunkte von Simualtionen (z.B. mit klassische Molekular-Dynamik) oder Experimenten zu liefern oder solche zu erklären.

EPR spectroscopy as a tool for the elucidation of non-covalent structuring principles in complex soft matter

This thesis aims at connecting structural and functional changes of complex soft matter systems due to external stimuli with non-covalent molecular interaction profiles. It addresses the problem of elucidating non-covalent forces as structuring principle of mainly polymer-based systems in solution. The structuring principles of a wide variety of complex soft matter types are analyzed. In many cases this is done by exploring conformational changes upon the exertion of external stimuli. The central question throughout this thesis is how a certain non-covalent interaction profile leads to solution condition-dependent structuring of a polymeric system.rnTo answer this question, electron paramagnetic resonance (EPR) spectroscopy is chosen as the main experimental method for the investigation of the structure principles of polymers. With EPR one detects only the local surroundings or environments of molecules that carry an unpaired electron. Non-covalent forces are normally effective on length scales of a few nanometers and below. Thus, EPR is excellently suited for their investigations. It allows for detection of interactions on length scales ranging from approx. 0.1 nm up to 10 nm. However, restriction to only one experimental technique likely leads to only incomplete pictures of complex systems. Therefore, the presented studies are frequently augmented with further experimental and computational methods in order to yield more comprehensive descriptions of the systems chosen for investigation.rnElectrostatic correlation effects in non-covalent interaction profiles as structuring principles in colloid-like ionic clusters and DNA condensation are investigated first. Building on this it is shown how electrostatic structuring principles can be combined with hydrophobic ones, at the example of host-guest interactions in so-called dendronized polymers (denpols).rnSubsequently, the focus is shifted from electrostatics in dendronized polymers to thermoresponsive alkylene oxide-based materials, whose structuring principles are based on hydrogen bonds and counteracting hydrophobic interactions. The collapse mechanism in dependence of hydrophilic-hydrophobic balance and topology of these polymers is elucidated. Complementarily the temperature-dependent phase behavior of elastin-like polypeptides (ELPs) is investigated. ELPs are the first (and so far only) class of compounds that is shown to feature a first-order inverse phase transition on nanoscopic length scales.rnFinally, this thesis addresses complex biological systems, namely intrinsically disordered proteins (IDPs). It is shown that the conformational space of the IDPs Osteopontin (OPN), a cytokine involved in metastasis of several kinds of cancer, and BASP1 (brain acid soluble protein one), a protein associated with neurite outgrowth, is governed by a subtle interplay between electrostatic forces, hydrophobic interaction, system entropy and hydrogen bonds. Such, IDPs can even sample cooperatively folded structures, which have so far only been associated with globular proteins.

Il principio di non discriminazione e l'identita' costituzionale dell'Unione Europea

La definizione dell’ordinamento dell’Unione come ordinamento costituzionale è centrale, ma resta frammentata. Per restituirle sistematicità è importante individuare un principio sul quale poggiarne il consolidamento. Per questo si è scelto di esaminare il principio di non discriminazione attraverso l’analisi della giurisprudenza, con l’obiettivo di verificare se questo principio è parte fondamentale dell’identità costituzionale dell’Unione Europea. Nella prima parte della tesi si analizza la struttura del giudizio sulla discriminazione davanti alla CGUE e davanti alla CEDU, mettendo in evidenza come la struttura ricordi sempre di più quella del giudizio di costituzionalità. Nella seconda parte ci si concentra sul contributo dato dal principio di non discriminazione all’identità costituzionale dell’Unione Europea attraverso la lotta contro specifiche tipologie di discriminazione. Poiché i motivi di discriminazione sono molto numerosi, si è stabilito di esaminare quei motivi che sono regolati dal diritto derivato. Per questo la seconda parte dell’analisi si è concentrata sulle discriminazioni a motivo della nazionalità (dir. 2004/38/CE), della razza (dir. 2000/43/CE), del genere (dir. 2006/54/CE, dir. 2004/113/CE) dell’età, disabilità, religione ed orientamento sessuale (dir. 2000/78/CE). Dall’analisi della giurisprudenza e del diritto derivato che ne dà attuazione è possibile comprendere che questo principio, oltre ad essere sostenuto da un vero e proprio giudizio di legittimità costituzionale (il rinvio pregiudiziale), ha gli strumenti necessari a permetterne lo sviluppo tenendo conto delle identità costituzionali degli stati membri e può aiutare ad offrire delle risposte rispetto a uno dei problemi fondamentali inerenti all’efficacia del diritto dell’Unione Europea: la tensione fra il principio di attribuzione e la dottrina degli effetti diretti. Le conclusioni di questo lavoro portano a sostenere che è possibile individuare una giurisprudenza della Corte che, attraverso alcuni passaggi fondamentali (le sentenze Mangold, Kucukdeveci, Hay, Deckmyn e Zambrano), definisce il principio di non discriminazione come principio fondamentale, e costituzionale, del diritto dell’Unione Europea.

An Analysis of Capacities, Moral Hierarchies, and the Moral Status of Non-Human Animals in Contemporary Animal Rights Work

The primary objective of this thesis is to demonstrate the pernicious impact that moral hierarchies have on our perception and subsequent treatment of non-human animals. Moral hierarchies in general are characterized by a dynamic in which one group is considered to be fundamentally superior to a lesser group. This thesis focuses specifically on the moral hierarchies that arise when humans are assumed to be superior to non-human animals in virtue of their advanced mental capabilities. The operative hypothesis of this thesis is essentially that moral hierarchies thwart the provision of justice to non-human animals in that they function as a justification for otherwise impermissible actions. When humans are assumed to be fundamentally superior to non-human animals then it becomes morally permissible for humans to kill non-human animals and utilize them as mere instrumentalities. This thesis is driven primarily by an in-depth analysis of the approaches to animal rights that are provided by Peter Singer, Tom Regan, and Gary Francione. Each of these thinkers claim that they overcome anthropocentrism and provide approaches that preclude the establishment of a moral hierarchy. One of the major findings of this thesis, however, is that Singer and Regan offer approaches that remain highly anthropocentric despite the fact that each thinker claims that they have overcome anthropocentrism. The anthropocentrism persists in these respective approaches in that each thinkers gives humans Regan and Singer have different conceptions of the criteria that are required to afford a being moral worth, but they both give preference to beings that have the cognitive ability to form desires regarding the future.. As a result, a moral hierarchy emerges in which humans are regarded to be fundamentally superior. Francione, however, provides an approach that does not foster a moral hierarchy. Francione creates such an approach by applying the principle of equal consideration of interests in a consistent manner. Moreover, Francione argues that mere sentience is both a necessary and sufficient condition for being eligible and subsequently receiving moral consideration. The upshot of this thesis is essentially that the moral treatment of animals is not compatible with the presence of a moral hierarchy. As a result, this thesis demonstrates that future approaches to animal rights must avoid the establishment of moral hierarchies. The research and analysis within this thesis demonstrates that this is not a possibility, however, unless all theories of justice that are to accommodate animals abandon the notion that cognition matters morally.

Inhibition of L-type amino acid transport with non-physiological amino acids in the Pahenu2 mouse model of phenylketonuria

Phenylketonuria, an autosomal recessive Mendelian disorder, is one of the most common inborn errors of metabolism. Although currently treated by diet, many suboptimal outcomes occur for patients. Neuropathological outcomes include cognitive loss, white matter abnormalities, and hypo- or demyelination, resulting from high concentrations and/or fluctuating levels of phenylalanine. High phenylalanine can also result in competitive exclusion of other large neutral amino acids from the brain, including tyrosine and tryptophan (essential precursors of dopamine and serotonin). This competition occurs at the blood brain barrier, where the L-type amino acid transporter, LAT1, selectively facilitates entry of large neutral amino acids. The hypothesis of these studies is that certain non-physiological amino acids (NPAA; DL-norleucine (NL), 2-aminonorbornane (NB; 2-aminobicyclo-(2,1,1)-heptane-2-carboxylic acid), α-aminoisobutyrate (AIB), and α-methyl-aminoisobutyrate (MAIB)) would competitively inhibit LAT1 transport of phenylalanine (Phe) at the blood-brain barrier interface. To test this hypothesis, Pah-/- mice (n=5, mixed gender; Pah+/-(n=5) as controls) were fed either 5% NL, 0.5% NB, 5% AIB or 3% MAIB (w/w 18% protein mouse chow) for 3 weeks. Outcome measurements included food intake, body weight, brain LNAAs, and brain monoamines measured via LCMS/MS or HPLC. Brain Phe values at sacrifice were significantly reduced for NL, NB, and MAIB, verifying the hypothesis that these NPAAs could inhibit Phe trafficking into the brain. However, concomitant reductions in tyrosine and methionine occurred at the concentrations employed. Blood Phe levels were not altered indicating no effect of NPAA competitors in the gut. Brain NL and NB levels, measured with HPLC, verified both uptake and transport of NPAAs. Although believed predominantly unmetabolized, NL feeding significantly increased blood urea nitrogen. Pah-/-disturbances of monoamine metabolism were exacerbated by NPAA intervention, primarily with NB (the prototypical LAT inhibitor). To achieve the overarching goal of using NPAAs to stabilize Phe transport levels into the brain, a specific Phe-reducing combination and concentration of NPAAs must be found. Our studies represent the first in vivo use of NL, NB and MAIB in Pah-/- mice, and provide proof-of-principle for further characterization of these LAT inhibitors. Our data is the first to document an effect of MAIB, a specific system A transport inhibitor, on large neutral amino acid transport.

One-year outcomes of repeated adjunctive photodynamic therapy during periodontal maintenance: a proof-of-principle randomized-controlled clinical trial

BACKGROUND: Single photodynamic therapy (PDT) has been effective in initial periodontal therapy, but only improved bleeding on probing (BoP) in maintenance patients after a single use. Repeated PDT has not been addressed. OBJECTIVES: To study the possible added benefits of repeated adjunctive PDT to conventional treatment of residual pockets in patients enrolled in periodontal maintenance. MATERIAL AND METHODS: Ten maintenance patients with 70 residual pockets [probing pocket depth (PPD)>or=5 mm] were randomly assigned for treatment five times in 2 weeks (Days 0, 1, 2, 7, 14) with PDT (test) or non-activated laser (control) following debridement. The primary outcome variable was PPD, and the secondary variables were clinical attachment level (CAL) and BoP. These were assessed at 3, 6 and 12 months following the interventions. RESULTS: Greater PPD reductions were observed in the test (-0.67 +/- 0.34; p=0.01) compared with the control patients (-0.04 +/- 0.33; NS) after 6 months. Significant CAL gain (+0.52 +/- 0.31; p=0.01) was noted for the test, but not in the control (-0.27 +/- 0.52; NS) patients after 6 months. BoP percentages decreased significantly in test (97-64%, 67%, 77%), but not control patients after 3, 6 and 12 months. CONCLUSIONS: Repeated (five times) PDT adjunctive to debridement yielded improved clinical outcomes in residual pockets in maintenance patients. The effects were best documented after 6 months.

Non-invasive and non-occlusive blood pressure estimation via a chest sensor

The clinical demand for a device to monitor Blood Pressure (BP) in ambulatory scenarios with minimal use of inflation cuffs is increasing. Based on the so-called Pulse Wave Velocity (PWV) principle, this paper introduces and evaluates a novel concept of BP monitor that can be fully integrated within a chest sensor. After a preliminary calibration, the sensor provides non-occlusive beat-by-beat estimations of Mean Arterial Pressure (MAP) by measuring the Pulse Transit Time (PTT) of arterial pressure pulses travelling from the ascending aorta towards the subcutaneous vasculature of the chest. In a cohort of 15 healthy male subjects, a total of 462 simultaneous readings consisting of reference MAP and chest PTT were acquired. Each subject was recorded at three different days: D, D+3 and D+14. Overall, the implemented protocol induced MAP values to range from 80 ± 6 mmHg in baseline, to 107 ± 9 mmHg during isometric handgrip maneuvers. Agreement between reference and chest-sensor MAP values was tested by using intraclass correlation coefficient (ICC = 0.78) and Bland-Altman analysis (mean error = 0.7 mmHg, standard deviation = 5.1 mmHg). The cumulative percentage of MAP values provided by the chest sensor falling within a range of ±5 mmHg compared to reference MAP readings was of 70%, within ±10 mmHg was of 91%, and within ±15mmHg was of 98%. These results point at the fact that the chest sensor complies with the British Hypertension Society (BHS) requirements of Grade A BP monitors, when applied to MAP readings. Grade A performance was maintained even two weeks after having performed the initial subject-dependent calibration. In conclusion, this paper introduces a sensor and a calibration strategy to perform MAP measurements at the chest. The encouraging performance of the presented technique paves the way towards an ambulatory-compliant, continuous and non-occlusive BP monitoring system.

Advances in the Simultaneous Multiple Surface optical design method for imaging and non-imaging applications

Classical imaging optics has been developed over centuries in many areas, such as its paraxial imaging theory and practical design methods like multi-parametric optimization techniques. Although these imaging optical design methods can provide elegant solutions to many traditional optical problems, there are more and more new design problems, like solar concentrator, illumination system, ultra-compact camera, etc., that require maximum energy transfer efficiency, or ultra-compact optical structure. These problems do not have simple solutions from classical imaging design methods, because not only paraxial rays, but also non-paraxial rays should be well considered in the design process. Non-imaging optics is a newly developed optical discipline, which does not aim to form images, but to maximize energy transfer efficiency. One important concept developed from non-imaging optics is the “edge-ray principle”, which states that the energy flow contained in a bundle of rays will be transferred to the target, if all its edge rays are transferred to the target. Based on that concept, many CPC solar concentrators have been developed with efficiency close to the thermodynamic limit. When more than one bundle of edge-rays needs to be considered in the design, one way to obtain solutions is to use SMS method. SMS stands for Simultaneous Multiple Surface, which means several optical surfaces are constructed simultaneously. The SMS method was developed as a design method in Non-imaging optics during the 90s. The method can be considered as an extension to the Cartesian Oval calculation. In the traditional Cartesian Oval calculation, one optical surface is built to transform an input wave-front to an out-put wave-front. The SMS method however, is dedicated to solve more than 1 wave-fronts transformation problem. In the beginning, only 2 input wave-fronts and 2 output wave-fronts transformation problem was considered in the SMS design process for rotational optical systems or free-form optical systems. Usually “SMS 2D” method stands for the SMS procedure developed for rotational optical system, and “SMS 3D” method for the procedure for free-form optical system. Although the SMS method was originally employed in non-imaging optical system designs, it has been found during this thesis that with the improved capability to design more surfaces and control more input and output wave-fronts, the SMS method can also be applied to imaging system designs and possesses great advantage over traditional design methods. In this thesis, one of the main goals to achieve is to further develop the existing SMS-2D method to design with more surfaces and improve the stability of the SMS-2D and SMS-3D algorithms, so that further optimization process can be combined with SMS algorithms. The benefits of SMS plus optimization strategy over traditional optimization strategy will be explained in details for both rotational and free-form imaging optical system designs. Another main goal is to develop novel design concepts and methods suitable for challenging non-imaging applications, e.g. solar concentrator and solar tracker. This thesis comprises 9 chapters and can be grouped into two parts: the first part (chapter 2-5) contains research works in the imaging field, and the second part (chapter 6-8) contains works in the non-imaging field. In the first chapter, an introduction to basic imaging and non-imaging design concepts and theories is given. Chapter 2 presents a basic SMS-2D imaging design procedure using meridian rays. In this chapter, we will set the imaging design problem from the SMS point of view, and try to solve the problem numerically. The stability of this SMS-2D design procedure will also be discussed. The design concepts and procedures developed in this chapter lay the path for further improvement. Chapter 3 presents two improved SMS 3 surfaces’ design procedures using meridian rays (SMS-3M) and skew rays (SMS-1M2S) respectively. The major improvement has been made to the central segments selections, so that the whole SMS procedures become more stable compared to procedures described in Chapter 2. Since these two algorithms represent two types of phase space sampling, their image forming capabilities are compared in a simple objective design. Chapter 4 deals with an ultra-compact SWIR camera design with the SMS-3M method. The difficulties in this wide band camera design is how to maintain high image quality meanwhile reduce the overall system length. This interesting camera design provides a playground for the classical design method and SMS design methods. We will show designs and optical performance from both classical design method and the SMS design method. Tolerance study is also given as the end of the chapter. Chapter 5 develops a two-stage SMS-3D based optimization strategy for a 2 freeform mirrors imaging system. In the first optimization phase, the SMS-3D method is integrated into the optimization process to construct the two mirrors in an accurate way, drastically reducing the unknown parameters to only few system configuration parameters. In the second optimization phase, previous optimized mirrors are parameterized into Qbfs type polynomials and set up in code V. Code V optimization results demonstrates the effectiveness of this design strategy in this 2-mirror system design. Chapter 6 shows an etendue-squeezing condenser optics, which were prepared for the 2010 IODC illumination contest. This interesting design employs many non-imaging techniques such as the SMS method, etendue-squeezing tessellation, and groove surface design. This device has theoretical efficiency limit as high as 91.9%. Chapter 7 presents a freeform mirror-type solar concentrator with uniform irradiance on the solar cell. Traditional parabolic mirror concentrator has many drawbacks like hot-pot irradiance on the center of the cell, insufficient use of active cell area due to its rotational irradiance pattern and small acceptance angle. In order to conquer these limitations, a novel irradiance homogenization concept is developed, which lead to a free-form mirror design. Simulation results show that the free-form mirror reflector has rectangular irradiance pattern, uniform irradiance distribution and large acceptance angle, which confirm the viability of the design concept. Chapter 8 presents a novel beam-steering array optics design strategy. The goal of the design is to track large angle parallel rays by only moving optical arrays laterally, and convert it to small angle parallel output rays. The design concept is developed as an extended SMS method. Potential applications of this beam-steering device are: skylights to provide steerable natural illumination, building integrated CPV systems, and steerable LED illumination. Conclusion and future lines of work are given in Chapter 9. Resumen La óptica de formación de imagen clásica se ha ido desarrollando durante siglos, dando lugar tanto a la teoría de óptica paraxial y los métodos de diseño prácticos como a técnicas de optimización multiparamétricas. Aunque estos métodos de diseño óptico para formación de imagen puede aportar soluciones elegantes a muchos problemas convencionales, siguen apareciendo nuevos problemas de diseño óptico, concentradores solares, sistemas de iluminación, cámaras ultracompactas, etc. que requieren máxima transferencia de energía o dimensiones ultracompactas. Este tipo de problemas no se pueden resolver fácilmente con métodos clásicos de diseño porque durante el proceso de diseño no solamente se deben considerar los rayos paraxiales sino también los rayos no paraxiales. La óptica anidólica o no formadora de imagen es una disciplina que ha evolucionado en gran medida recientemente. Su objetivo no es formar imagen, es maximazar la eficiencia de transferencia de energía. Un concepto importante de la óptica anidólica son los “rayos marginales”, que se pueden utilizar para el diseño de sistemas ya que si todos los rayos marginales llegan a nuestra área del receptor, todos los rayos interiores también llegarán al receptor. Haciendo uso de este principio, se han diseñado muchos concentradores solares que funcionan cerca del límite teórico que marca la termodinámica. Cuando consideramos más de un haz de rayos marginales en nuestro diseño, una posible solución es usar el método SMS (Simultaneous Multiple Surface), el cuál diseña simultáneamente varias superficies ópticas. El SMS nació como un método de diseño para óptica anidólica durante los años 90. El método puede ser considerado como una extensión del cálculo del óvalo cartesiano. En el método del óvalo cartesiano convencional, se calcula una superficie para transformar un frente de onda entrante a otro frente de onda saliente. El método SMS permite transformar varios frentes de onda de entrada en frentes de onda de salida. Inicialmente, sólo era posible transformar dos frentes de onda con dos superficies con simetría de rotación y sin simetría de rotación, pero esta limitación ha sido superada recientemente. Nos referimos a “SMS 2D” como el método orientado a construir superficies con simetría de rotación y llamamos “SMS 3D” al método para construir superficies sin simetría de rotación o free-form. Aunque el método originalmente fue aplicado en el diseño de sistemas anidólicos, se ha observado que gracias a su capacidad para diseñar más superficies y controlar más frentes de onda de entrada y de salida, el SMS también es posible aplicarlo a sistemas de formación de imagen proporcionando una gran ventaja sobre los métodos de diseño tradicionales. Uno de los principales objetivos de la presente tesis es extender el método SMS-2D para permitir el diseño de sistemas con mayor número de superficies y mejorar la estabilidad de los algoritmos del SMS-2D y SMS-3D, haciendo posible combinar la optimización con los algoritmos. Los beneficios de combinar SMS y optimización comparado con el proceso de optimización tradicional se explican en detalle para sistemas con simetría de rotación y sin simetría de rotación. Otro objetivo importante de la tesis es el desarrollo de nuevos conceptos de diseño y nuevos métodos en el área de la concentración solar fotovoltaica. La tesis está estructurada en 9 capítulos que están agrupados en dos partes: la primera de ellas (capítulos 2-5) se centra en la óptica formadora de imagen mientras que en la segunda parte (capítulos 6-8) se presenta el trabajo del área de la óptica anidólica. El primer capítulo consta de una breve introducción de los conceptos básicos de la óptica anidólica y la óptica en formación de imagen. El capítulo 2 describe un proceso de diseño SMS-2D sencillo basado en los rayos meridianos. En este capítulo se presenta el problema de diseñar un sistema formador de imagen desde el punto de vista del SMS y se intenta obtener una solución de manera numérica. La estabilidad de este proceso se analiza con detalle. Los conceptos de diseño y los algoritmos desarrollados en este capítulo sientan la base sobre la cual se realizarán mejoras. El capítulo 3 presenta dos procedimientos para el diseño de un sistema con 3 superficies SMS, el primero basado en rayos meridianos (SMS-3M) y el segundo basado en rayos oblicuos (SMS-1M2S). La mejora más destacable recae en la selección de los segmentos centrales, que hacen más estable todo el proceso de diseño comparado con el presentado en el capítulo 2. Estos dos algoritmos representan dos tipos de muestreo del espacio de fases, su capacidad para formar imagen se compara diseñando un objetivo simple con cada uno de ellos. En el capítulo 4 se presenta un diseño ultra-compacto de una cámara SWIR diseñada usando el método SMS-3M. La dificultad del diseño de esta cámara de espectro ancho radica en mantener una alta calidad de imagen y al mismo tiempo reducir drásticamente sus dimensiones. Esta cámara es muy interesante para comparar el método de diseño clásico y el método de SMS. En este capítulo se presentan ambos diseños y se analizan sus características ópticas. En el capítulo 5 se describe la estrategia de optimización basada en el método SMS-3D. El método SMS-3D calcula las superficies ópticas de manera precisa, dejando sólo unos pocos parámetros libres para decidir la configuración del sistema. Modificando el valor de estos parámetros se genera cada vez mediante SMS-3D un sistema completo diferente. La optimización se lleva a cabo variando los mencionados parámetros y analizando el sistema generado. Los resultados muestran que esta estrategia de diseño es muy eficaz y eficiente para un sistema formado por dos espejos. En el capítulo 6 se describe un sistema de compresión de la Etendue, que fue presentado en el concurso de iluminación del IODC en 2010. Este interesante diseño hace uso de técnicas propias de la óptica anidólica, como el método SMS, el teselado de las lentes y el diseño mediante grooves. Este dispositivo tiene un límite teórica en la eficiencia del 91.9%. El capítulo 7 presenta un concentrador solar basado en un espejo free-form con irradiancia uniforme sobre la célula. Los concentradores parabólicos tienen numerosas desventajas como los puntos calientes en la zona central de la célula, uso no eficiente del área de la célula al ser ésta cuadrada y además tienen ángulos de aceptancia de reducido. Para poder superar estas limitaciones se propone un novedoso concepto de homogeneización de la irrandancia que se materializa en un diseño con espejo free-form. El análisis mediante simulación demuestra que la irradiancia es homogénea en una región rectangular y con mayor ángulo de aceptancia, lo que confirma la viabilidad del concepto de diseño. En el capítulo 8 se presenta un novedoso concepto para el diseño de sistemas afocales dinámicos. El objetivo del diseño es realizar un sistema cuyo haz de rayos de entrada pueda llegar con ángulos entre ±45º mientras que el haz de rayos a la salida sea siempre perpendicular al sistema, variando únicamente la posición de los elementos ópticos lateralmente. Las aplicaciones potenciales de este dispositivo son varias: tragaluces que proporcionan iluminación natural, sistemas de concentración fotovoltaica integrados en los edificios o iluminación direccionable con LEDs. Finalmente, el último capítulo contiene las conclusiones y las líneas de investigación futura.

Development of an Elevated Temperature Loop Heat Pipe for Space Applications and Investigation of Non Condensable Gas Impact on its Performance

Un caloducto en bucle cerrado o Loop Heat Pipe (LHP) es un dispositivo de transferencia de calor cuyo principio de operación se basa en la evaporación/condensación de un fluido de trabajo, que es bombeado a través de un circuito cerrado gracias a fuerzas de capilaridad. Gracias a su flexibilidad, su baja masa y su mínimo (incluso nulo) consumo de potencia, su principal aplicación ha sido identificada como parte del subsistema de control térmico de vehículos espaciales. En el presente trabajo se ha desarrollado un LHP capaz de funcionar eficientemente a temperaturas de hasta 125 oC, siguiendo la actual tendencia de los equipos a bordo de satélites de incrementar su temperatura de operación. En la selección del diseño optimo para dicho LHP, la compatibilidad entre materiales y fluido de trabajo se identificó como uno de los puntos clave. Para seleccionar la mejor combinación, se llevó a cabo una exhaustiva revisión del estado del arte, además de un estudio especifico que incluía el desarrollo de un banco de ensayos de compatibilidad. Como conclusión, la combinación seleccionada como la candidata idónea para ser integrada en el LHP capaz de operar hasta 125 oC fue un evaporador de acero inoxidable, líneas de titanio y amoniaco como fluido de trabajo. En esa línea se diseñó y fabricó un prototipo para ensayos y se desarrolló un modelo de simulación con EcosimPro para evaluar sus prestaciones. Se concluyó que el diseño era adecuado para el rango de operación definido. La incompatibilidad entre el fluido de trabajo y los materiales del LHP está ligada a la generación de gases no condensables. Para un estudio más detallado de los efectos de dichos gases en el funcionamiento del LHP se analizó su comportamiento con diferentes cantidades de nitrógeno inyectadas en su cámara de compensación, simulando un gas no condensable formado en el interior del dispositivo. El estudio se basó en el análisis de las temperaturas medidas experimentalmente a distintos niveles de potencia y temperatura de sumidero o fuente fría. Adicionalmente, dichos resultados se compararon con las predicciones obtenidas por medio del modelo en EcosimPro. Las principales conclusiones obtenidas fueron dos. La primera indica que una cantidad de gas no condensable más de dos veces mayor que la cantidad generada al final de la vida de un satélite típico de telecomunicaciones (15 años) tiene efectos casi despreciables en el funcionamiento del LHP. La segunda es que el principal efecto del gas no condensable es una disminución de la conductancia térmica, especialmente a bajas potencias y temperaturas de sumidero. El efecto es más significativo cuanto mayor es la cantidad de gas añadida. Asimismo, durante la campaña de ensayos se observó un fenómeno no esperado para grandes cantidades de gas no condensable. Dicho fenómeno consiste en un comportamiento oscilatorio, detectado tanto en los ensayos como en la simulación. Este efecto es susceptible de una investigación más profunda y los resultados obtenidos pueden constituir la base para dicha tarea. ABSTRACT Loop Heat Pipes (LHPs) are heat transfer devices whose operating principle is based on the evaporation/condensation of a working fluid, and which use capillary pumping forces to ensure the fluid circulation. Thanks to their flexibility, low mass and minimum (even null) power consumption, their main application has been identified as part of the thermal control subsystem in spacecraft. In the present work, an LHP able to operate efficiently up to 125 oC has been developed, which is in line with the current tendency of satellite on-board equipment to increase their operating temperatures. In selecting the optimal LHP design for the elevated temperature application, the compatibility between the materials and working fluid has been identified as one of the main drivers. An extensive literature review and a dedicated trade-off were performed, in order to select the optimal combination of fluids and materials for the LHP. The trade-off included the development of a dedicated compatibility test stand. In conclusion, the combination of stainless steel evaporator, titanium piping and ammonia as working fluid was selected as the best candidate to operate up to 125 oC. An LHP prototype was designed and manufactured and a simulation model in EcosimPro was developed to evaluate its performance. The first conclusion was that the defined LHP was suitable for the defined operational range. Incompatibility between the working fluid and LHP materials is linked to Non Condensable Gas (NCG) generation. Therefore, the behaviour of the LHP developed with different amounts of nitrogen injected in its compensation chamber to simulate NCG generation, was analyzed. The LHP performance was studied by analysis of the test results at different temperatures and power levels. The test results were also compared to simulations in EcosimPro. Two additional conclusions can be drawn: (i) the effects of an amount of more than two times the expected NCG at the end of life of a typical telecommunications satellite (15 years) is almost negligible on the LHP operation, and (ii) the main effect of the NCG is a decrease in the LHP thermal conductance, especially at low temperatures and low power levels. This decrease is more significant with the progressive addition of NCG. An unexpected phenomenon was observed in the LHP operation with large NCG amounts. Namely, an oscillatory behaviour, which was observed both in the tests and the simulation. This effect provides the basis for further studies concerning oscillations in LHPs.

On a competitive system under chemotactic effects with non-local terms

In this paper, we study a system of partial differential equations describing the evolution of a population under chemotactic effects with non-local reaction terms. We consider an external application of chemoattractant in the system and study the cases of one and two populations in competition. By introducing global competitive/cooperative factors in terms of the total mass of the populations, weobtain, forarangeofparameters, thatanysolutionwithpositive and bounded initial data converges to a spatially homogeneous state with positive components. The proofs rely on the maximum principle for spatially homogeneous sub- and super-solutions.

Judicial Selection, Lay Participation, and Judicial Culture in the Czech Republic: A Study in a Central European (Non)Transformation. College of Europe Research Paper in Law 03/2014

Introduction. The idea that “merit” should be the guiding principle of judicial selections is a universal principle, unlikely to be contested in whatever legal system. What differs considerably across legal cultures, however, is the way in which “merit” is defined. For deeper cultural and historical reasons, the current definition of “merit” in the process of judicial selections in the Czech Republic, at least in the way it is implemented in the institutional settings, is an odd mongrel. The old technocratic Austrian judicial heritage has in some aspects merged with, in others was altered or destroyed, by the Communist past. After 1989, some aspects of the judicial organisation were amended, with the most problematic elements removed. Furthermore, several old as well as new provisions relating to the judiciary were struck down by the Constitutional Court. However, apart from these rather haphazard interventions, there has been neither a sustained discussion as to how a new judicial architecture and system of judicial appointments ought to look like nor much of broader, conceptual reform in this regard. Thus, some twenty five years after the Velvet Revolution of 1989, the guiding principles for judicial selection and appointments are still a debate to be had.

Taxation of couples: a mirrleesian approach for non-unitary households

Optimal tax theory in the Mirrlees’ (1971) tradition implicitly relies on the assumption that all agents are single or that couples may be treated as individuals, despite accumulating evidence against this view of household behavior. We consider an economy where agents may either be single or married, in which case choices result from Nash bargaining between spouses. In such an environment, tax schedules must play the double role of: i) defining households’ objective functions through their impact on threat points, and; ii) inducing the desired allocations as optimal choices for households given these objectives. We find that the taxation principle, which asserts that there is no loss in relying on tax schedules is not valid here: there are constrained efficient allocations which cannot be implemented via taxes. More sophisticated mechanisms expand the set of implementable allocations by: i) aligning the households’ and planner’s objectives; ii) manipulating taxable income elasticities, and; iii) freeing the design of singles’ tax schedules from its consequences on households’ objectives.

Supreme Emergencies and the protection of non-combatants in war

Is it ever justifiable to target non-combatants deliberately? This article assesses Michael Walzer's claim that the deliberate targeting of non-combatants may be justifiable during 'supreme emergencies', a view that has received some support but that has elicited little debate. It argues that the supreme emergencies exception to the prohibition on targeting non-combatants is problematic for at least four reasons. First, its utilitarianism contradicts Walzer's wider ethics of war based on a conception of human rights. Second, the exception may undermine the principle of non-combatant immunity. Third, it is based on a historical fallacy. Finally, it is predicated on a strategic fallacy-the idea that killing noncombatants can win wars. The case for rejecting the exception, however, has been opposed by those who persuasively argue that it is wrong to tie leaders' hands when they confront supreme emergencies. The final part of the article addresses this question and suggests that the principle of proportionality may give political leaders room for manoeuvre in supreme emergencies without permitting them deliberately to target non-combatants.