Subject of the work is design of pedestrian bridge across the river Morava. There are compared 3 variants of structures. Thesis is focused on stress ribbon supported by arch. The geometry of initial stage has been searched to form self-anchored structural system. The structure is verified in according to the European Standards.

The subject of this thesis is alternative design of the pedestrian bridge over Brno reservoir near Veveří castle. Three preliminary studies are created. The chosen variant consists of a stress ribbon supported by a steel arches. Time dependent analysis of load cases effects during construction stages is calculated by ANSYS. The bridge is verified according to the European Standards.

This thesis concerns a range of aspects of theoretical physics. It is composed of two parts. In the first part we motivate our line of research, and introduce and discuss the relevant concepts. In the second part, four research papers are collected. The first paper deals with a possible extension of general relativity, namely the recently discovered classically consistent bimetric theory. In this paper we study the behavior of perturbations of the metric(s) around cosmologically viable background solutions. In the second paper, we explore possibilities for particle physics with low-scale supersymmetry. In particular we consider the addition of supersymmetric higher-dimensional operators to the minimal supersymmetric standard model, and study collider phenomenology in this class of models. The third paper deals with a possible extension of the notion of Lie algebras within category theory. Considering Lie algebras as objects in additive symmetric ribbon categories we define the proper Killing form morphism and explore its role towards a structure theory of Lie algebras in this setting. Finally, the last paper is concerned with the computation of string amplitudes in four dimensional models with reduced supersymmetry. In particular, we develop general techniques to compute amplitudes involving gauge bosons and gravitons and explicitly compute the corresponding three- and four-point functions. On the one hand, these results can be used to extract important pieces of the effective actions that string theory dictates, on the other they can be used as a tool to compute the corresponding field theory amplitudes. / Over the last twenty years there have been spectacular observations and experimental achievements in fundamental physics. Nevertheless all the physical phenomena observed so far can still be explained in terms of two old models, namely the Standard Model of particle physics and the ΛCDM cosmological model. These models are based on profoundly different theories, quantum field theory and the general theory of relativity. There are many reasons to believe that the SM and the ΛCDM are effective models, that is they are valid at the energy scales probed so far but need to be extended and generalized to account of phenomena at higher energies. There are several proposals to extend these models and one promising theory that unifies all the fundamental interactions of nature: string theory. With the research documented in this thesis we contribute with four tiny drops to the filling of the fundamental physics research pot. When the pot will be saturated, the next fundamental discovery will take place.

In this paper we explore the slice-ribbon conjecture for some families of pretzel knots. Donaldson's diagonalization theorem provides a powerful obstruction to sliceness via the union of the double branched cover W of B⁴ over a slicing disk and a plumbing manifold P([capital gamma]). Donaldson's theorem classifies all slice 4-strand pretzel knots up to mutation. The correction term is another 3-manifold invariant defined by Ozsváth and Szabó. For a slice knot K the number of vanishing correction terms of Y[subscript K] is at least the square root of the order of H₁(Y[subscript K];Z). Donaldson's theorem and the correction term argument together give a strong condition for 5-strand pretzel knots to be slice. However, neither Donaldson's theorem nor the correction terms can distinguish 4-strand and 5-strand slice pretzel knots from their mutants. A version of the twisted Alexander polynomial proposed by Paul Kirk and Charles Livingston provides a feasible way to distinguish those 5-strand slice pretzel knots and their mutants; however the twisted Alexander polynomial fails on 4-strand slice pretzel knots. / text

La déformation de matériaux élastique dont l'une au moins des dimensions est petite apparaît dans un grand nombre de structures naturelles ou artificielles pour lesquelles une courbure spontanée est présente. Dans ces travaux de thèse, nous couplons plusieurs approches théoriques à des expériences macroscopiques sur des rubans élastiques afin de comprendre la dynamique d'enroulement de biomembranes ouvertes d'un trou. La motivation est issue d'observations récentes d'enroulements obtenues au cours de la sortie de parasites de la Malaria de globules rouges infectés, et de l'explosion de vésicules polymère. Dans une première partie, nous étudions théoriquement la stabilité d'un pore et la propagation de l'enroulement sur une biomembrane sphérique ouverte. Nous modélisons de façon géométrique l'enroulement toroïdal de la membrane par une spirale d'Archimède de révolution et décentrée. Avec cette hypothèse, nous montrons que la stabilité du pore vis-à-vis de l'enroulement dépend fortement de la tension de ligne et du cisaillement et nous discutons ces résultats dans le cadre de l'enroulement de membranes MIRBCs. De plus, en prenant en compte les différentes sources de dissipation, nous obtenons un très bon accord entre les données expérimentales obtenues pour les MIRBCs et la dynamique d'enroulement obtenue par le calcul. Notre approche montre en particulier que la dissipation dans la membrane due à la redistribution de la matière durant l'enroulement domine sur la dissipation visqueuse dans le milieu.Cependant, la complexité de la géométrie sphérique, ainsi que le nombre limité d'observations microscopiques à l'échelle de la membrane sont une entrave au développement de modèles plus détaillés qui permettraient de décrire complètement le couplage entre écoulement et déformation. Nous avons donc étudié dans une seconde partie la déformation d'enroulement dans le cas de rubans élastiques ayant une courbure spontanée dans différents milieux visqueux et pour différentes conditions élastiques. A grands nombres de Reynolds, en raison de la localisation de la courbure pour les rubans au cours de la propagation du front d'enroulement le long du matériau, nous montrons que l'enroulement atteint rapidement une vitesse de propagation constante. Dans ce régime, le ruban s'enroule sur lui-même de façon compacte, sur un cylindre dont la taille est prévue à partir de la solution de l'onde stationnaire pour l'Elastica. A faible nombre de Reynolds, cependant, se rapprochant des conditions d'enroulement d'une membrane microscopique, nous mettons en évidence l'influence des forces de lubrification sur la nature non-compacte de l'enroulement. La taille globale de la spirale de ruban augmente dans le temps conduisant à une diminution de la puissance élastique libérée et donc à une diminution de la vitesse. Nous discutons dans quelle mesure ces résultats peuvent faire avancer la modélisation de l'enroulement dans les MIRBCs et les vésicules polymère. / Curling deformation of thin elastic surfaces appears in numerous natural and man-made structures where a spontaneous curvature is present. In this thesis, we couple theoretical approaches and macroscopic experiments on elastic ribbons to understand the dynamics of curling of opened bio-membranes, motivated by the need to better understand recent microscopic observations during egress of Malaria infected red blood cells (MIRBC) and bursting of artificial polymersomes.In a first part, we study theoretically pore stability and curling propagation of an initially opened spherical bio-membrane. We model geometrically curling deformation as the revolution of a decentered Archimedean spiral, leading to a prescribed toroidal wrapping of the membrane. In this configuration, we show how the stability of a pore to curling depends strongly on both line-tension and shear elasticity and we discuss these results in relation to the curling of MIRBCs membranes. Moreover, taking into account viscous dissipations, the consequent dynamics we calculate agrees quantitatively well with experimental data obtained during opening of MIRBCs. Our approach shows in particular how the membrane dissipation resulting from the surface redistribution dominates curling dynamics over outer viscous dissipation.However, the complexity of the spherical geometry and the lack of detailed images in microscopic observations hamper the development of more accurate models where the coupling between flow and deformation is fully understood. Subsequently, we study in a second part the curling deformation of macroscopic naturally curved elastic ribbons in different viscous media and elastic conditions. At high Reynolds numbers, due to the tendency of ribbons to localize bending deformations when a curling front travels down the material, we show that curling reaches rapidly a constant propagating velocity. In this regime, the ribbon wraps itself into a compact roll whose size is predicted through the solitary wave solution of the associated Elastica. At low Reynolds numbers, however, closer to the hydrodynamic conditions of curling in microscopic membranes, we show that the strong lubrication forces induce a non-compact curling. The overall size of the spiraling ribbon increases in time leading to a temporal decrease of the released elastic power and therefore a consequent decrease in velocity. We discuss how such discovery sheds a new light on the modeling of curling in MIRBCs and polymersomes.

Gegenstand der vorliegenden Untersuchungen waren das retinaspezifische palmitoylierte Membranprotein 4 (engl. membrane palmitoylated protein 4, MPP4) und das ubiquitär exprimierte MPP5, die beide zur großen Familie der Membran-assoziierten Guanylatkinasen (engl. membrane-associated guanylate kinases, MAGUKs) gehören. Beide Proteine haben wichtige organisatorische Funktionen als Adapterproteine in der Netzhaut. MPP4 ist am Aufbau von präsynaptischen Proteinkomplexen in den Photorezeptor-Ribbonsynapsen beteiligt. Ein Fehlen von MPP4 in Mäusen führt zum Verlust von einigen präsynaptischen Proteinen von der Ribbonsynapse, was eine wichtige Rolle von MPP4 für die Organisation dieses Komplexes indiziert. Um neue Komponenten dieses Multiproteinkomplexes zu identifizieren, wurde in der vorliegenden Arbeit ein proteomischer Ansatz etabliert. Dazu wurde der MPP4-assoziierte Proteinkomplex aus Proteinextrakten der bovinen Retina durch Immunaffinitätschromatographie isoliert, mittels zweidimensionaler Gelelektrophorese aufgetrennt und resultierende Protein-spots massenspektrometrisch analysiert. Diese Untersuchungen identifizierten 18 kopräzipitierte Proteine. Darunter waren der bekannte Interaktionspartner Veli3 und das MAGUK-Protein PSD95. Für letzteres konnte gezeigt werden, dass speziell die β-Isoform von PSD95 mit MPP4 über die N-terminalen L27-Domänen heterodimerisiert. Daneben konnte die Assoziation von MPP4 mit Hsc70 und Recoverin durch unabhängige Bindungs-assays verifiziert werden, wobei diese Interaktionen indirekt waren und möglicherweise von retinaspezifischen Proteinen vermittelt werden. Diese Ergebnisse unterstützen die herausragende Rolle von MPP4 als Gerüstprotein für die Organisation eines Proteinkomplexes der Photorezeptorsynapse, der an der Regulierung der Ca2+-Homöostase in den präsynaptischen Enden, sowie vermutlich auch an der Exozytose der synaptischen Vesikel beteiligt ist. Die übrigen kopräzipitierten Proteine waren Bestandteile des Zytoskeletts und verschiedener Signalwege und wahrscheinlich unspezifische Kontaminanten. Das MPP5-Protein ist Teil eines evolutionär konservierten Proteinkomplexes, der für die Entstehung und Aufrechterhaltung der apikobasalen Polarität in Epithelzellen eine wichtige Rolle spielt und in der Netzhaut für die speziellen Zellverbindungen zwischen Müller-Gliazellen und Photorezeptoren in der externen limitierenden Membran essentiell ist. Mutationen, die zu Störungen in der Funktion dieses Proteinkomplexes führen, verursachen retinale Defekte bei Mensch (z.B. Retinitis Pigmentosa, Lebersche kongenitale Amaurose), Maus, Zebrafisch und Fruchtfliege. Die PDZ-Domäne von MPP5 bindet an den C-Terminus der CRB-Proteine. In der vorliegenden Arbeit wurde die Auswirkung einer Punktmutation in der PDZ-Domäne von MPP5 (V301N), funktionell untersucht. Diese hat im Zebrafisch eine fehlende Photorezeptoradhäsion und die Zerstörung der retinalen Architektur zur Folge. Es wurde gezeigt, dass die V301N-Mutation die Interaktion zwischen MPP5 und den drei CRB-Isoformen verhindert. Außerdem führt sie zu einer Fehllokalisierung von heterolog exprimiertem MPP5V301N in MDCK-Zellen, die zudem einen erhöhten transepithelialen Widerstand aufweisen. Über quantitative real-time PCR wurde in diesen Zellen eine verminderte Genexpression von Untereinheiten des apikalen epithelialen Natriumkanals ENaC und der basolateralen Na+/K+-ATPase festgestellt, was die Ursache für einen verminderten Ionenfluss durch die Zellschicht darstellen könnte. Somit übt heterolog exprimiertes MPP5V301N in MDCK-Zellen einen dominanten Effekt aus, der möglicherweise über einen Einfluss auf die Genregulation bestimmter Proteine vermittelt wird. Zur Untersuchung welche Auswirkungen die MPP5V301N-Mutation in vivo hat, wurde eine MPP5V301N-knock-in-Mauslinie generiert. Die bisherige Charakterisierung der Mäuse zeigte bei heterozygoten Tieren keinen äußerlich erkennbaren Phänotyp, wohingegen homozygote Mäuse nicht lebensfähig waren. Vermutlich führt das Vorkommen beider mutanter Allele in frühen embryonalen Stadien zum Abstoßen der Embryos. Das Mausmodell bietet die Basis für weitere Untersuchungen über die molekularen Konsequenzen einer Expression von MPP5V301N in der Netzhaut und anderen Geweben und wird Beiträge zur Aufklärung von Entstehungsmechanismen CRB1-MPP5-assoziierter Netzhauterkrankungen liefern. / The objects of the present study were the retina specific membrane palmitoylated protein 4 (MPP4) and the ubiquitous expressed MPP5 protein which belong to the large family of the membrane-associated guanylate kinase homologs (MAGUKs). Both proteins have important organizational functions as adaptor proteins in the retina. MPP4 is involved in the assembly of presynaptic protein complexes in the photoreceptor synapses. The absence of MPP4 in mice leads to the loss of several presynaptic proteins from the ribbon synapse indicating an important role for MPP4 in organizing this complex. This work was aimed to identify new components of this multiprotein complex by establishing a proteomic approach. More precisely, the MPP4-associated protein complex was isolated with immunoaffinity chromatography from bovine retinal protein extracts followed by two-dimensional electrophoresis and analysis of the resulting protein spots by mass spectrometry. This analysis identified 18 co-precipitated proteins. Among these molecules the known interacting partner Veli3 and the MAGUK protein PSD95 were detected. For the latter, a selective association between MPP4 and the PSD95-β isoform was demonstrated showing specific heterodimerization of their N-terminal L27 domains. Additionally independent binding assays verified the association of MPP4 with recoverin and Hsc70. These interactions seem to be indirect and are presumably mediated by retina specific proteins in vivo. In summary, these findings support a protruding role for MPP4 as scaffolding protein for the organization of a protein complex of the photoreceptor synapses, which is involved in the regulation of Ca2+ homeostasis within the presynaptic terminals and eventually plays a role in synaptic vesicle exocytosis. The remaining co-precipitated proteins represented cytoskeletal constituents and components of different pathways and were probably unspecific contaminants. The MPP5 protein, a member of the evolutionarily conserved CRB protein complex, plays an important role in establishing and maintaining the apicobasal polarity of epithelial cells. Furthermore, this complex is essential for specific cell junctions between Müller glia cells and photoreceptors in the outer limiting membrane of the retina. Mutations that disrupt the function of this protein complex were reported to cause retinal defects in human (e.g. retinitis pigmentosa, Leber’s congenital amaurosis), mouse, zebrafish and fruit fly. The PDZ domain of MPP5 binds to the C-terminus of the CRB proteins. The present study aimed to analyze the consequences of a point mutation within the PDZ domain of MPP5 (V301N). In zebrafish, this mutation resulted in the loss of photoreceptor adhesion and in the disruption of retinal layers. It was demonstrated that the V301N mutation prevents the interaction between MPP5 and the three CRB isoforms. Additionally, heterologously expressed MPP5V301N mislocalizes in MDCK cells which furthermore develop an increased transepithelial resistance. Quantitative real-time PCR revealed decreased gene expression levels for subunits of the apical epithelial sodium channel (ENaC) and the basolateral Na+/K+-ATPase, supposedly causing the reduced ion movement through the cell layer. Thus, heterologously expressed MPP5V301N apparently has a dominant effect in MDCK cells which might be mediated by an influence on the gene expression of other yet unknown proteins. To further elucidate the MPP5V301N mutation in vivo, a knock in mouse line was generated. So far the characterization of these mice revealed no apparent phenotype for heterozygous animals, whereas homozygous mice were not viable. The presence of both mutant alleles presumably results in a rejection at early embryonic stages. The mouse model provides the basis to further analyze molecular consequences of MPP5V301N expression in the retina and other tissues and will contribute to enlighten the development of CRB1-MPP5-associated retinal diseases.

A model for DNA recombination uses 4-valent rigid vertex graphs, called assembly graphs. An assembly graph, similarly to the projection of knots, can be associated with an unsigned Gauss code, or double occurrence word. We define biologically motivated reductions that act on double occurrence words and, in turn, on their associated assembly graphs. For every double occurrence word w there is a sequence of reduction operations that may be applied to w so that what remains is the empty word, [epsilon]. Then the nesting index of a word w, denoted by NI(w), is defined to to be the least number of reduction operations necessary to reduce w to [epsilon]. The nesting index is the first property of assembly graphs that we study. We use chord diagrams as tools in our study of the nesting index. We observe two double occurrence words that correspond to the same circle graph, but that have arbitrarily large differences in nesting index values. In 2012, Buck et al. considered the cellular embeddings of assembly graphs into orientable surfaces. The genus range of an assembly graph [Gamma], denoted gr([Gamma]), was defined to be the set of integers g where g is the genus of an orientable surface F into which [Gamma] cellularly embeds. The genus range is the second property of assembly graphs that we study. We generalize the notion of the genus range to that of the genus spectrum, where for each g [isin] gr([Gamma]) we consider the number of orientable surfaces F obtained from [Gamma] by a special construction, called a ribbon graph construction, that have genus g. By considering this more general notion we gain a better understanding of the genus range property. Lastly, we show how one can obtain the genus spectrum of a double occurrence word from the genus spectrums of its irreducible parts, i.e., its double occurrence subwords. In the final chapter we consider constructions of double occurrence words that recognize certain values for nesting index and genus range. In general, we find that for arbitrary values of nesting index [ge] 2 and genus range, there is a double occurrence word that recognizes those values.

No description available.

Photovoltaics offers a unique solution to energy and environmental problems simultaneously. However, widespread application of photovoltaics will not be realized until costs are reduced by about a factor of four without sacrificing performance. Silicon crystallization and wafering account for about 55% of the photovoltaic module manufacturing cost, but can be reduced significantly if a ribbon silicon material, such as String Ribbon Si, is used as an alternative to cast Si. However, the growth of String Ribbon leads to a high density of electrically active bulk defects that limit the minority carrier lifetime and solar cell performance. The research tasks of this thesis focus on the understanding, development, and implementation of defect passivation techniques to increase the bulk carrier lifetime in String Ribbon Si in order to enhance solar cell efficiency. Hydrogen passivation of defects in Si can be performed during solar cell processing by utilizing the hydrogen available during plasma-enhanced chemical vapor deposition (PECVD) of SiNx:H films. It is shown in this thesis that hydrogen passivation of defects during the simultaneous anneal of a screen-printed Al layer on the back and a PECVD SiNx:H film increases the bulk lifetime in String Ribbon by more than 30 ?A three step physical model is proposed to explain the hydrogen defect passivation. Appropriate implementation of the Al-enhanced defect passivation treatment leads to String Ribbon solar cell efficiencies as high as 14.7%. Further enhancement of bulk lifetime up to 92 ?s achieved through in-situ NH3 plasma pretreatment and low-frequency (LF) plasma excitation during SiNx:H deposition followed by a rapid thermal anneal (RTA). Development of an optimized two-step RTA firing cycle for hydrogen passivation, the formation of an Al-doped back surface field, and screen-printed contact firing results in solar cell efficiencies as high as 15.6%. In the final task of this thesis, a rapid thermal treatment performed in a conveyer belt furnace is developed to achieve a peak efficiency of 15.9% with a bulk lifetime of 140 ?Simulations of further solar cell efficiency enhancement up to 17-18% are presented to provide guidance for future research.

Roads are significant objects of an infrastructure and the extraction of roads from aerial and satellite images are important for different applications such as automated map generation and change detection. Roads are also important to detect other structures such as buildings and urban areas. In this thesis, the road extraction approach is based on Active Contour Models for 1- meter resolution gray level images. Active Contour Models contains Snake Approach. During applications, the road structure was separated as salient-roads, non-salient roads and crossings and extraction of these is provided by using Ribbon Snake and Ziplock Snake methods. These methods are derived from traditional snake model. Finally, various experimental results were presented. Ribbon and Ziplock Snake methods were compared for both salient and non-salient roads. Also these methods were used to extract roads in an image. While Ribbon snake is described for extraction of salient roads in an image, Ziplock snake is applied for extraction of non-salient roads. Beside these, some constant variables in literature were redefined and expressed in a formula as depending on snake approach and a new approach for extraction of crossroads were described and tried.