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Molecular Evolution and Functional Characterization of the Visual Pigment Proteins of the Great Bowerbird (Chlamydera nuchalis) and Other Vertebratesvan Hazel, Ilke 16 December 2013 (has links)
Visual pigments are light sensitive receptors in the eye that form the basis of sensory visual transduction. This thesis presents three studies that explore visual pigment proteins in vertebrates using a number of computational and experimental methods in an evolutionary framework. The objective is not only to identify, but also to experimentally investigate the functional consequences of genetic variation in vertebrate visual pigments. The focus is on great bowerbirds (Chlamydera nuchalis), which are a model system in visual ecology due to their spectacular behaviour of building and decorating courtship bowers. There are 4 chapters: Chapter 1 introduces background information on visual pigments and vision in birds. Among visual pigment types, the short-wavelength-sensitive (SWS1) pigments have garnered particular interest due to the broad spectral range among vertebrates and the importance of UV signals in communication. Chapter 2 investigates the evolutionary history of SWS1 in vertebrates with a view toward its utility as a phylogenetic marker. Chapter 3 investigates SWS1 evolution and short-wavelength vision in birds, with particular focus on C. nuchalis and its SWS1. The evolution of spectral tuning mechanisms mediating UV/violet vision in passerines and parrots is elucidated in this chapter using site-directed mutagenesis, protein expression, and phylogenetic recreation of ancestral opsins. While cone opsins mediate colour vision in bright light, the rhodopsin visual pigment contained in rod photoreceptors is critical for dim light vision. Detailed characterization of rhodopsin function has only been conducted on a few model systems. Chapter 4 examines C. nuchalis RH1 using a number of functional assays in addition to absorbance spectra, including hydroxylamine sensitivity and the rate of retinal release. This chapter includes an investigation into the role of amino acid mutations typical of dim-light adapted vertebrates, D83N and A292S, in regulating functional properties of bovine and avian RH1s using site-directed mutagenesis. Together these chapters describe naturally occurring mutations in visual pigments and explore the way they can influence visual perception. These represent one of the few investigations of visual pigments from a species that is not a model lab organism and form a significant contribution to the field of visual pigment biochemistry and evolution.
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The rate-limiting mechanism for the heterogeneous burning of iron in normal gravity and reduced gravityWard, Nicholas Rhys January 2007 (has links)
This thesis presents a research project in the field of oxygen system fire safety relating to the heterogeneous burning of iron in normal gravity and reduced gravity. Fires involving metallic components in oxygen systems often occur, with devastating and costly results, motivating continued research to improve the safety of these devices through a better understanding of the burning phenomena. Metallic materials typically burn in the liquid phase, referred to as heterogeneous burning. A review of the literature indicates that there is a need to improve the overall understanding of heterogeneous burning and better understand the factors that influence metal flammability in normal gravity and reduced gravity. Melting rates for metals burning in reduced gravity have been shown to be higher than those observed under similar conditions in normal gravity, indicating that there is a need for further insight into heterogeneous burning, especially in regard to the rate-limiting mechanism. The objective of the current research is to determine the cause of the higher melting rates observed for metals burning in reduced gravity to (a) identify the rate-limiting mechanism during heterogeneous burning and thus contribute to an improved fundamental understanding of the system, and (b) contribute to improved oxygen system fire safety for both ground-based and space-based applications. In support of the work, a 2-s duration ground-based drop tower reduced-gravity facility was commissioned and a reduced-gravity metals combustion test system was designed, constructed, commissioned and utilised. These experimental systems were used to conduct tests involving burning 3.2-mm diameter cylindrical iron rods in high-pressure oxygen in normal gravity and reduced gravity. Experimental results demonstrate that at the onset of reduced gravity, the burning liquid droplet rapidly attains a spherical shape and engulfs the solid rod, and that this is associated with a rapid increase in the observed melting rate. This link between the geometry of the solid/liquid interface and melting rate during heterogeneous burning is of particular interest in the current research. Heat transfer analysis was performed and shows that a proportional relationship exists between the surface area of the solid/liquid interface and the observed melting rate. This is confirmed through detailed microanalysis of quenched samples that shows excellent agreement between the proportional change in interfacial surface area and the observed melting rate. Thus, it is concluded that the increased melting rates observed for metals burning in reduced gravity are due to altered interfacial geometry, which increases the contact area for heat transfer between the liquid and solid phases. This leads to the conclusion that heat transfer across the solid/liquid interface is the rate-limiting mechanism for melting and burning, limited by the interfacial surface area. This is a fundamental result that applies in normal gravity and reduced gravity and clarifies that oxygen availability, as postulated in the literature, is not rate limiting. It is also established that, except for geometric changes at the solid/liquid interface, the heterogeneous burning phenomenon is the same at each gravity level. A conceptual framework for understanding and discussing the many factors that influence heterogeneous burning is proposed, which is relevant to the study of burning metals and to oxygen system fire safety in both normal-gravity and reduced-gravity applications.
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Proměny domu (analýza domu v portugalském románu 20. století) / Transformations of the Concept of House (An Analysis of the House in the 20th Century Portuguese Novel)Válová, Karolina January 2018 (has links)
The dissertation under the title Transformations of the Concept of House (An Analysis of the House in the 20th Century Portuguese Novel) endeavours to map the concept, portrayal and primarily the transformations of the space of a house, which is at the same time interpreted as an archetypical space universal in the 20th century Portuguese novel. Following the introduction and a summary of various literary theory approaches to the analysis of a house, Chapter 2 focuses in particular on a topological analysis and an analysis of the symbolic space. The topos of the house is fundamental for thematology and literary topology. A house, representing either a dwelling place, a temporary refuge or a home, is an essential space in the majority of literary stories; it is a certain static counterpart to a literary character, it forms their background or represents an aim to which they are heading. Its organization may reflect a character's nature or emphasize a significant contradiction between the space and the human being inhabiting it. As the role, function, form and significance of a literary character and of other constitutive elements of a narrative text were transformed in the course of the 20th century, the concept of the space of a house also underwent significant changes. Chapter 3 of the...
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Mecanical and numerical models to unidimensional flexible structures / Modelos mecânicos e numéricos para estruturas flexíveis unidimensionaisAntônio José Boness dos Santos 02 August 2007 (has links)
Apresentamos um modelo matemático geral, baseado na teoria de Cosserat para estruturas flexíveis unidimensionais, em regime de deslocamentos finitos e sujeitas a restrições unilaterais. Ao modelo geral agregamos a hipótese de inextensibilidade e, desprezando os efeitos do cisalhamento e das forças inerciais, formulamos o problema variacionalmente
tanto na forma cinemática quanto em Lagrangiano Aumentado. Para esta última formulação, construímos aproximações por elementos finitos de Galerkin e
utilizamos um algoritmo do tipo Uzawa para a solução do problema aproximado. Apresentamos estudos numéricos com o intuito de avaliar a formulação, validar o algoritmo de solução e exemplificar possíveis aplicações práticas do modelo.
Buscando viabilizar uma análise numérica, realizamos uma linearização consistente do modelo geral apresentado anteriormente, produzindo um modelo em regime de pequenos deslocamentos e deformações, descrito no espaço tridimensional. Para este problema, introduzimos uma aproximação por elementos finitos mistos estabilizados, adicionando à formulação de Galerkin formas residuais de mínimos quadrados provenientes das equações de equilíbrio. Provamos que esta formulação atende às condições suficientes para existência e unicidade de solução, independente da esbeltez da estrutura. Apresentamos estimativas de erro indicando taxas de convergência e resultados numéricos comprovando tais taxas.
Apresentamos algumas aplicações dos modelos ao estudo de estabilidade de dutos aquecidos e enterrados, na análise da estabilidade de armaduras de risers e umbilicais e, na área biológica, apontamos as possibilidades de suas utilizações na modelagem de moléculas de ADN.
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Objekt pro administrativmí a logistické účely / Office and logictic buildingNavrátil, Ondřej January 2012 (has links)
Design of a steel supporting structure for one-storeyed hall based on ground plan of 60 x 80 m, clear height 10 m and total height 13,3 m. In the front part there is along the whole widht designed two-storeyed skeleton structure penetrating into the hall. From the second floor rods supported frontal part which exceeds ground plan by 2 m and on the right side is closed by pre-set cylindric structure with radius 8,6 m which covers the right frontal corner of building. The cylindric structure is around its perimeter distanced max 3,6 m from hall grand plan and is supported by posts. Both spaces had saddle roof with 8% slant, gutter edge in height 11,6 m, top line in height 12,8 m. Walls are around perimeter closed by horizontal atic in height of 13,3 m. Shape and dimensional design, load specification – stady, utility, climacic load. Calculation of imide forces and further static dimensioning of the main supporting elements and selected details. Elaboration of design documentation (dosposition, production drawing of the anchorage plan, details definited by project supervizor).
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Víceúčelová sportovní hala / Multi - Purpose Sports HallBaudišová, Monika January 2014 (has links)
This thesis deals with design of a multi-purpose sports hall. The aim of this work is to design a support structure with a diameter of 80.0 m at ± 0.000. Construction of a circular layout in the level of ± 0.000 of an external diameter 80.0 m. Height of the hall at the top is 20.0 m Indoors girders is solved in 36 beams which meet at the middle of the rings. Ensure the stability of bracing. Anchoring is done by pin connections located at the bottom of the strip, anchored in concrete bases through the base plate and pre-concreted anchor bolts.
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Ocelová konstrukce vojenského muzea / Steel structure of a military museumŠašinka, Jakub January 2015 (has links)
The diploma thesis describes the design and assessment of steel structure of the roofing of the military museum in Králíky. The supporting structure of hall is 40.00 meters span. The total layout are 55.93 x 72.04 m, building height 11.43 m, 16.11 m pylon height. Main construction material is steel, grade S355, secondary constructions are made from steel grade S235, rods are made from steel grade S460. I did optimization of steel structure and chose the best option. For this option I made detailed structural analysis. It is prepared by static analysis of the main load-bearing parts of the structure, including joints and details. The supporting structure of hall consists in the transverse direction from the curved spatial lattice structure made of steel circular tubes which hang on rods on a sloped pylon. Part of the report is open-air roofing.
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Trojlodní objekt pro průmyslovou výrobu. / Three-Aisled Steel BuildingLečbych, Antonín January 2015 (has links)
The thesis contains the design and assessment of three-aisled steel building for small metal production. Supporting span of construction hall is 9, 18 and 9 m. In the middle wing is situated bridge crane with capacity of 2 tons. The estimated location of the object is Luhačovice. The initial design concept was specified by supervisor (as the idea of the investor/architect), for which was did static and structural solution and assembly details. For selected option was made a calculation of supporting structures and selected assembly details. The hall has a rectangular floor plan of 36x36m and ridge height is 9 m. The central wing is made of steel and side extensions are made of glued laminated timber.
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Konstrukce univerzálního zařízení na dělení pneumatik . / Design of Universal Equipment for Tire CuttingKohoutek, Petr January 2009 (has links)
The main content of of this thesis is a construction design and analysis of a machine for cutting tires. The resulting solution emerges from the design options and the option that meets the best selection criteria is chosen. Then the thesis stops for a while at the choice of cutting technology and tries to exemine its suitability for cutting tires. In its other part there is an attempt to clarify the relevant parts of the machine, where the benefits of three-dimensional views is used. Basic design and check calculations are done in the selected machine parts.
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Výpočtová simulace kosoúhlého rovnání tyčí / Computational simulation of cross-roll leveling of rodsBenešovský, Marek January 2015 (has links)
Final thesis describes two variants of computational models to simulate cross-roll leveling of rods, which are based on the Lagrangian approach to describe the continuum. Implementation of both variants was performed in ANSYS software, and their main difference lies in the choice of the type of elements for the discretization. An integral part of this thesis is the description of the principle, which is an evaluation of the curvature of the rod after completion of the simulation leveling. In the other part of the work are presented the results, which are then compared with realized experiment and simulation algorithm for cross-roll leveling based on the Euler approach. The final part is dedicated to the optimal settings of the leveller.
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