Experimental observations indicate the presence of attached, gravity induced, horizontal buoyant currents above large area fires. Their driving mechanism is indirect and resembles the one observed above heated horizontal plates. Classic plume modelling is satisfactory for providing information for the flow far from the source. In dealing with large areas and directing attention to the flow close to the source, the classic plume theory should fail because the radial pressure gradient that is responsible for the driving of the flow is squeezed in the long and thin classic plume assumption. For this we propose a new plume structure for the description of the buoyant flow above a circular region of large radius L as “The flow field must be divided into three regions. A region where the flow is predominantly horizontal and attached to the surface, a transition region from horizontal to vertical where separation of the attached current takes place, and a region where vertical flow is established and classic plume theory can be applied”. A model for the description of the gross properties of the horizontal currents is developed under the term “horizontal plume”. The modified Richardson number for the horizontal plume a, being analogous to the radius of the large area, is studied asymptotically in the limit a → ∞ and second order uniformly valid semi-analytical solutions are obtained. The hot plate experiment was set up in order to test the model and facilitate its improvement. A chapter is dedicated to the data analysis coming from thermocouple readings and visualisation of the flow using particle image velocimetry.In the remainder of this thesis two classic problems of laminar natural convection are revisited. That of the first order laminar boundary layer above an isothermal circular plate of radius a and the first order laminar boundary layer above the semi- infinite plate inclined to horizontal. In both cases allowances to variable property effects were made through the introduction of a nondimensional parameter λT, with its value set to zero implying the assumption of the Boussinesq approximation. For the circular plate, fourth order series solutions were obtained valid at the edge of the plate where the effects of λT and Prandtl number Pr are studied. Furthermore a finite difference scheme for the numerical solution of the nonsimilar partial integro- differential equation was developed using the Keller Box method and compared with results obtained from the commercial finite element software COMSOL Multiphysics 3.5a. For the semi-infinite plate, fourth order series approximations valid at the edge of the plate were obtained, while an extensive analysis for the effect of λT, Pr and inclination parameter σ was performed on the flow. Positions of the separation points when the inclination is negative (σ < 0) as a function of Pr and λT were recovered.

[EN] The purpose of the Ph.D. Thesis "Dynamics of strongly continuous semigroups associated to certain differential equations'' is to analyse, from the point of view of functional analysis, the dynamics of solutions of linear evolution equations. These solutions can be represented by a strongly continuous semigroup on an infinite-dimensional Banach space. The aim of our research is to provide global conditions for chaos, in the sense of Devaney, and stability properties of strongly continuous semigroups which are solutions of linear evolution equations. This work is composed of three principal chapters. Chapter 0 is introductory and defines basic terminology and notation used, besides presenting the basic results that we will use throughout this thesis. Chapters 1 and 2 describe, in general way, a strongly continuous semigroup induced by a semiflow in Lebesgue and Sobolev spaces which is a solution of a linear first order partial differential equation. Moreover, some characterizations of the main dynamical properties, including hypercyclicity, mixing, weakly mixing, chaos and stability are given along these chapters. Chapter 3 describes the dynamical properties of a difference equation based on the so-called birth-and-death model and analyses the conditions previously proven for this model improving them by employing a different strategy. The goal of this thesis is to characterize dynamical properties of these kind of strongly continuous semigroups in a general way, whenever possible, and to extend these results to another spaces. Along this memory, these findings are compared with the previous ones given by many authors in recent years. / [ES] La presente memoria "Dinámica de semigrupos fuertemente continuos asociadas a ciertas ecuaciones diferenciales'' es analizar, desde el punto de vista del análisis funcional, la dinámica de las soluciones de ecuaciones de evolución lineales. Estas soluciones pueden ser representadas por semigrupos fuertemente continuos en espacios de Banach de dimensión infinita. El objetivo de nuestra investigación es proporcionar condiciones globales para obtener caos, en el sentido de Devaney, y propiedades de estabilidad de semigrupos fuertemente continuos, los cuales son soluciones de ecuaciones de evolución lineales. Este trabajo está compuesto de tres capítulos principales. El Capítulo 0 es introductorio y define la terminología básica y notación usada, además de presentar los resultados básicos que usaremos a lo largo de esta tesis. Los Capítulos 1 y 2 describen, de forma general, un semigrupo fuertemente continuo inducido por un semiflujo en espacios de Lebesgue y en espacios de Sobolev, los cuales son solución de una ecuación diferencial lineal en derivadas parciales de primer orden. Además, algunas caracterizaciones de las principales propiedades dinámicas, incluyendo hiperciclicidad, mezclante, débil mezclante, caos y estabilidad, se obtienen a lo largo de estos capítulos. El Capítulo 3 describe las propiedades dinámicas de una ecuación en diferencias basada en el llamado modelo de nacimiento-muerte y analiza las condiciones previamente probadas para este modelo, mejorándolas empleando una estrategia diferente. La finalidad de esta tesis es caracterizar propiedades dinámicas para este tipo de semigrupos fuertemente continuos de forma general, cuando sea posible, y extender estos resultados a otros espacios. A lo largo de esta memoria, estos resultados son comparados con los resultados previos dados por varios autores en años recientes. / [CAT] La present memòria "Dinàmica de semigrups fortament continus associats a certes equacions diferencials'' és analitzar, des del punt de vista de l'anàlisi funcional, la dinàmica de les solucions d'equacions d'evolució lineals. Aquestes solucions poden ser representades per semigrups fortament continus en espais de Banach de dimensió infinita. L'objectiu de la nostra investigació es proporcionar condicions globals per obtenir caos, en el sentit de Devaney, i propietats d'estabilitat de semigrups fortament continus, els quals són solucions d'equacions d'evolució lineals. Aquest treball està compost de tres capítols principals. El Capítol 0 és introductori i defineix la terminologia bàsica i notació utilitzada, a més de presentar els resultats bàsics que utilitzarem al llarg d'aquesta tesi. Els Capítols 1 i 2 descriuen, de forma general, un semigrup fortament continu induït per un semiflux en espais de Lebesgue i en espais de Sobolev, els quals són solució d'una equació diferencial lineal en derivades parcials de primer ordre. A més, algunes caracteritzacions de les principals propietats dinàmiques, incloent-hi hiperciclicitat, mesclant, dèbil mesclant, caos i estabilitat, s'obtenen al llarg d'aquests capítols. El Capítol 3 descrivís les propietats dinàmiques d'una equació en diferències basada en el model de naixement-mort i analitza les condicions prèviament provades per aquest model, millorant-les utilitzant una estratègia diferent. La finalitat d'aquesta tesi és caracteritzar propietats dinàmiques d'aquest tipus de semigrups fortament continus de forma general, quan siga possible, i estendre aquests resultats a altres espais. Al llarg d'aquesta memòria, aquests resultats són comparats amb els resultats previs obtinguts per diversos autors en anys recents. / Aroza Benlloch, J. (2015). Dynamics of strongly continuous semigroups associated to certain differential equations [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/57186 / TESIS

The object of the thesis is the computational complexity of certain combinatorial optimisation problems called \emph{valued constraint satisfaction problems}, or \emph{VCSPs} for short. The requirements and optimisation criteria of these problems are expressed by sums of \emph{(valued) constraints} (also called \emph{cost functions}). More precisely, the input of a VCSP consists of a finite set of variables, a finite set of cost functions that depend on these variables, and a cost $u$; the task is to find values for the variables such that the sum of the cost functions is at most $u$. By restricting the set of possible cost functions in the input, a great variety of computational optimisation problems can be modelled as VCSPs. Recently, the computational complexity of all VCSPs for finite sets of cost functions over a finite domain has been classified. Many natural optimisation problems, however, cannot be formulated as VCSPs over a finite domain. We initiate the systematic investigation of infinite-domain VCSPs by studying the complexity of VCSPs for piecewise linear (PL) and piecewise linear homogeneous (PLH) cost functions. The VCSP for a finite set of PLH cost functions can be solved in polynomial time if the cost functions are improved by fully symmetric fractional operations of all arities. We show this by (polynomial-time many-one) reducing the problem to a finite-domain VCSP which can be solved using a linear programming relaxation. We apply this result to show the polynomial-time tractability of VCSPs for {\it submodular} PLH cost functions, for {\it convex} PLH cost functions, and for {\it componentwise increasing} PLH cost functions; in fact, we show that submodular PLH functions and componentwise increasing PLH functions form maximally tractable classes of PLH cost functions. We define the notion of {\it expressive power} for sets of cost functions over arbitrary domains, and discuss the relation between the expressive power and the set of fractional operations improving the same set of cost functions over an arbitrary countable domain. Finally, we provide a polynomial-time algorithm solving the restriction of the VCSP for {\it all} PL cost functions to a fixed number of variables.

By counting 1's in the "right half" of 2w consecutive rows, we locate the main diagonal of any doubly infinite permutation matrix with bandwidth w. Then the matrix can be correctly centered and factored into block-diagonal permutation matrices. Part II of the paper discusses the same questions for the much larger class of band-dominated matrices. The main diagonal is determined by the Fredholm index of a singly infinite submatrix. Thus the main diagonal is determined "at infinity" in general, but from only 2w rows for banded permutations.

Die Immobilisierung homogener Katalysatoren ist eine wichtige Methode zur Realisierung der Abtrennbarkeit und Wiederverwendbarkeit aktiver Spezies. Im Rahmen dieser Arbeit wurde durch die Komplexierung von Palladium mit 1,4-Bis-(4′-pyrazolyl)benzen ein neues mikroporöses Koordinationspolymer generiert und dieses als heterogener Katalysator in der Suzuki-Miyaura-Kreuzkupplungsreaktion erfolgreich eingesetzt. Dabei konnten vollständige Umsätze und hohe Selektivitäten erzielt werden, die vergleichbar zu bereits kommerziell erhältlichen homogenen Katalysatoren sind. Die Besonderheit des Katalysators ist, neben dessen außergewöhnlich hohen chemischen Stabilität, die Variation seiner Struktureigenschaften durch die Wahl der Synthesebedingungen und die damit verbundene Steuerung seiner katalytischen Aktivität.:1 EINLEITUNG 1 2 KENNTNISSTAND 5 2.1 Immobilisierung von Palladium 5 2.1.1 Organische Trägermaterialien 6 2.1.1.1 Polyanilin 6 2.1.1.2 Polymerverankerte Phosphanliganden 8 2.1.1.3 Imprägnierung komplexfunktionalisierter Polymere 10 2.1.2 Anorganische Trägermaterialien 11 2.1.2.1 Aktivkohle 11 2.1.2.2 Metalloxide 13 2.1.3 Hybridmaterialien 14 2.1.3.1 Infinite Coordination Polymers 14 2.1.3.2 Metal-Organic Frameworks 17 2.2 Die Suzuki-Miyaura-Kreuzkupplungsreaktion 24 2.2.1 Allgemeine mechanistische Vorstellungen zur Reaktion 27 2.2.2 Die PdII/PdIV-Katalyse – Ein umstrittener Mechanismus 29 3 AUFGABENSTELLUNG UND LÖSUNGSSTRATEGIE 33 4 ERGEBNISSE UND DISKUSSION 38 4.1 Charakterisierung des Koordinationspolymers [Pd(BPB)]n 38 4.1.1 Bis(triphenylphosphan)palladium(II)dichlorid als Palladiumprecursor 38 4.1.1.1 Synthese und Charakterisierung 38 4.1.1.2 Porosität 49 4.1.1.3 Oxidationsstufe des Palladium 57 4.1.1.4 Strukturdiskussion 64 4.1.2 Mechanistische Untersuchungen zur Bildung von [Pd(BPB)]n 74 4.1.2.1 Verfolgung des Reaktionsablaufes mittels Kernresonanzspektroskopie 74 4.1.2.2 Vorschläge zum Reaktionsmechanismus 81 4.1.3 Alternative Palladiumprecursoren für [Pd(BPB)]n 88 4.1.3.1 Bis(triphenylphosphan)palladium(II)dibromid 88 4.1.3.2 Natriumtetrachloropalladat 90 4.1.3.3 Weitere Palladiumprecursoren 93 4.1.4 Alternative Synthesetechniken für [Pd(BPB)]n 94 4.1.4.1 Solvothermale Synthese 94 4.1.4.2 Basendiffusionsmethode 95 4.2 Heterogen katalysierte Suzuki-Miyaura-Reaktion mit [Pd(BPB)]n 97 4.2.1 Verifizierung des Versuchsablaufes mittels Vergleichskatalysatoren 97 4.2.2 Die katalytische Aktivität von [Pd(BPB)]n in der Suzuki-Reaktion 100 4.2.3 Katalysatorstabilität und Wiederverwendbarkeit von [Pd(BPB)]n 104 4.2.4 Einfluss der Reaktionstemperatur 110 4.2.5 Einfluss des phosphanhaltigen Palladiumprecursors 114 5 ZUSAMMENFASSUNG 116 A EXPERIMENTELLER TEIL 120 A.1 Synthese und Charakterisierung von [Pd(BPB)]n 120 A.1.1 Arbeitstechniken und verwendete Chemikalien 120 A.1.2 Synthesevorschriften für [Pd(BPB)]n 122 A.1.2.1 Darstellung von 1,4-Bis-(4′-pyrazolyl)benzen (H2BPB) 122 A.1.2.2 Fällungssynthese von [Pd(BPB)]n 122 A.1.2.3 Solvothermale Synthese von [Pd(BPB)]n 123 A.1.2.4 Diffusionskontrollierte Synthese von [Pd(BPB)]n 124 A.1.2.5 Synthese aus Natriumtetrachloropalladat 124 A.1.2.6 Synthese aus Palladiumacetat 124 A.1.2.7 Synthese aus PdBr2(PPh3)2 125 A.1.3 Charakterisierung von [Pd(BPB)]n 125 A.2 Durchführung der Suzuki-Miyaura-Reaktion 127 A.2.1 Umsetzung von 4-Bromacetophenon mit Phenylboronsäure 127 A.2.2 Katalysatorstabilität und Wiederverwendbarkeit 128 A.2.3 Analyse und Identifizierung der Reaktionsprodukte 129 B ANHANG 134 B.1 Charakterisierung von [Pd(BPB)]n 134 B.2 Mechanistische Untersuchungen zur Bildung von [Pd(BPB)]n 140 B.3 Katalytische Aktivität von [Pd(BPB)]n 141 B.4 Tabellenverzeichnis 143 B.5 Abbildungsverzeichnis 145 B.6 Symbole und Abkürzungen 150 B.7 Literaturverzeichnis 154

No description available.

On étudie la conjecture des graphes jumeaux dénombrables, cas spécifique d’une conjecture de Thomassé, qui dit que le nombre de jumeaux d’un graphe dénombrable ( ses sous-graphes propres desquels il est aussi un sous-graphe propre) est soit nul, soit infini. On commence par étudier les graphes auto-abrités, que nous définissons, et en utilisant notre classification de ces graphes nous prouvons la conjecture dans certains cas, en précisant la cardinalité exacte du nombre de jumeaux. Nous donnons également des contre-exemples à l’article de l’arXiv «Self-contained graphs». / We make progress on the Graph Alternative Conjecture, a special case of a conjecture of Thomassé which says that the number of twins of a countable graph (i.e. its proper subgraphs of which that graph is also a proper subgraph) is either null or infinite. We begin by studying self-embedded graphs, which we define, and using our classification of these graphs, we prove the conjecture in some cases while specifying the exact number of twins. We also give counter-examples to a paper on arXiv called "Self-contained graphs".

No description available.

This research thesis is an exploration into what possibilities lie beyond the representation of analog material when it transcends into the digital realm. Specifically, how printed comics can be altered in realtime by creator- allowed user interaction, when adapted for presentation within the digital sphere of mobile smartphones and computer tablets. Using legacy computer-game techniques like parallax scrolling with modern digital layer filters, device sensors and applying them in realtime to the comic creators digitally layered content, alternative forms of presentation arise.This is an investigation into the comic creator’s will of allowing possibilities of added depth perception, interactivity and alternative visual narratives in their comic, manga or graphic novels when employing new techniques based on sensor data input from a reader, like accelerometer-, gyroscope- or eye-tracking sensors. Several different techniques are evaluated. The focus is mainly on the context of creators of comics or manga who use digital tools and layer compositions when producing their work. Several aspects of the user-centered experience are also explored.Although mainly an interaction design project, most of the design methods are used from a service design approach, emphasizing co-design techniques like interviews, observations and user tests. The results are digital prototypes and proof-of-concepts featuring technology tests that support final design conclusions.The results will show both enthusiasm and reluctance from test subjects towards the new technologies presented. The professional craft of comic, manga and graphic novel creation has a deeply rooted aesthetic and production cycle in its history of the printed form. It could be difficult to alter its standard, reverence and nostalgia in the eyes of its readers and creators, when pursuing the digital format and narrative possibilities of the future. A video explaining the project’s “Drawn To Life” technology is available online.

Given a full-range simply-invariant shift-invariant subspace <i>M</i> of the vector-valued <i>L²</i> space on the unit circle, the classical Beurling-Lax-Halmos (BLH) theorem obtains a unitary operator-valued function <i>W</i> so that <i>M</i> may be represented as the image of of the Hardy space <i>H²</i> on the disc under multiplication by <i>W</i>. The work of Ball-Helton later extended this result to find a single function representing a so-called dual shift-invariant pair of subspaces <i>(M,M^Ã)</i> which together form a direct-sum decomposition of <i>L²</i>. In the case where the pair <i>(M,M^Ã)</i> are finite-dimensional perturbations of the Hardy space <i>H²</i> and its orthogonal complement, Ball-Gohberg-Rodman obtained a transfer function realization for the representing function <i>W</i>; this realization was parameterized in terms of zero-pole data computed from the pair <i>(M,M^Ã)</i>. Later work by Ball-Raney extended this analysis to the case of nonrational functions <i>W</i> where the zero-pole data is taken in an infinite-dimensional operator theoretic sense. The current work obtains analogues of these various results for arbitrary dual shift-invariant pairs <i>(M,M^Ã)</i> of the <i>L²</i> spaces on the real line; here, shift-invariance refers to invariance under the translation group. These new results rely on recent advances in the understanding of continuous-time infinite-dimensional input-state-output linear systems which have been codified in the book by Staffans. / Ph. D.