Cells of the retinal pigment epithelium (RPE) are generated prenatally and generally survive the lifetime of the individual without undergoing proliferation or replacement. Therefore, the mechanisms promoting individual RPE cell survival and longevity in vivo may be distinct from, or a limited subset of, the mechanisms known to promote survival in proliferative cells in culture. To identify specific factors that sustain cell viability independent of effects on cell division, we studied RPE cells in low-density suspension culture, in which cell proliferation is inhibited. Single cells from Xenopus laevis eyes were plated onto a non-adhesive surface in protein-free medium, then assayed for survival using the 3-(4, 5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay. Cell viability in these cultures was essentially undiminished over the initial 2 days. However, by approximately 1 week in culture, only an average of 53% of the cells remained alive. Plating cells on a fibronectin-coated substratum significantly enhanced survival, such that the number of cells alive at 1 week was 80-90% of the initial level. Essentially identical results were obtained with laminin- or collagen IV-coated substrata, or with insulin (5μg ml-1) in the medium. The absence of cell division in these cultures was confirmed by cell counting and BrdU incorporation experiments. Interestingly, in suspension cultures derived from monolayers previously established on microporous membrane filters, cells lost viability much faster (average of 80% dead at 3 days), and showed a relatively greater response to extracellular matrix proteins (five-fold increase in cell survival at 3 days). Enhanced RPE survival in response to fibronectin required spreading of the cell on a substratum, rather than mere adherence, as there was a high correlation between the percentage of spread cells and the percentage that were MTT-positive (r = 0·940). Cell spreading apparently enhanced survival by preventing the initiation of programmed cell death: unattached non-viable cells in culture exhibited morphological features expected of apoptosis, as well as positive staining by the TUNEL reaction. These studies demonstrate that, of several factors shown to maintain or increase cell number in proliferating cultures, some have their effect, at least in part, by promoting the survival of individual cells. The increased susceptibility of subcultured RPE to cell death has implications for clinical transplantation applications that may require manipulation of RPE in vitro.

The aim of the thesis is to devise a methodology which is capable of reliable evaluation of road vehicle’s crosswind sensitivity. The work consists of writing the mathematical model of a vehicle which includes aerodynamic loads and conducting a validation by means of technical experiment as defined by ISO 12021. A sensitivity analysis describing the influence of individual inputs on evaluation criteria of vehicle’s crosswind sensitivity is performed using the model, thereby establishing the overall model error caused by possible inaccuracies of input parameters. At the end, the relationship between discrete pressures on the surface of the vehicle in several aerodynamic configurations and the properties representing the vehicle’s motion is presented.

This diploma thesis deals with the solution of the southern bypass of the town of Kuřim, especially its connection to the road I / 43. The main goal was to optimize intersections and tracing affected communications. The work was based on previously prepared studies, from which were taken over the routes of the road I / 43 and the southern bypass of Kuřim.The proposal slightly modified the height and directional solution of the taken routes. Route road I / 43 is designed to affect the inhabitants of Moravské Knínice. Part of the work are also the designs of relocations of adjacent roads and new solutions resulting intersections. The proposal was prepared with regard to the Principles of Territorial Development of the South Moravian Region.

[pt] O estudo de bolhas de separação laminar em aerofólios que operam a baixos números de Reynolds é importante para diversas aplicações tais como: turbinas a gás, geradores eólicos, veículos aéreos não tripulados, dentre outros. A perda de performance desses equipamentos, normalmente, está associada à presença e à ruptura de bolhas de separação. Neste trabalho buscou-se investigar, experimentalmente, os efeitos relacionados a variação súbita no nível de perturbações do escoamento a montante da região de formação da bolha. A ideia é avaliar como o escoamento se comporta em uma situação onde o nível de turbulência do escoamento livre pode variar. No caso de turbinas, essa condição pode ser observada quando as esteiras dos aerofólios de um estágio influenciam aquelas do estágio seguinte. Apesar da relevância prática, o regime transiente foi pouco investigado na literatura. Para o presente estudo foi utilizado um canal de água do Laboratório de Engenharia de Fluidos. O gradiente de pressão, necessário para a formação da bolha, foi gerado com uma placa convergente-divergente e o nível de perturbações na camada limite foi controlado através de um gerador do tipo fita vibrante. Os campos de velocidades na região da bolha foram medidos com a técnica de Velocimetria por Imagem de Partícula com alta resolução temporal. A geração de perturbações e as medições de velocidade foram sincronizadas, permitindo assim o uso de técnicas de extração de médias de eventos. Caracterizou-se a bolha em um regime estacionário, onde não houve excitação de perturbações controladas a montante da bolha. Os resultados foram comparados com referências da literatura, apresentando boa concordância. No regime transiente, analisou-se o escoamento desde o instante em que o gerador de perturbações foi subitamente desligado até a recuperação completa da bolha. Nessas condições, notou-se que bolha cresceu até atingir um comprimento maior do que o observado no regime estacionário. Somente após o desprendimento de um grande vórtice, a bolha voltou a exibir características similares àquelas do regime estacionário. Esse comportamento se assemelha àquele reportado na literatura para ruptura de bolhas (bursting) mas que ainda não é bem compreendido. / [en] Laminar separation bubbles in Low Reynolds number airfoils is important for several applications such as: gas turbines, wind generators, unmanned aerial vehicles, among others. The performance loss of this airfoils is usually associated with the presence and rupture of separation bubbles. The effects related to the sudden variation of the level of flow disturbances upstream of the bubble formation region are investigated in this work. The idea is to evaluate how the flow behaves when subjected to a sudden variation in the freestream turbulence. This condition can be observed in airfoil cascade of turbines, where the wake of a previous stage can influence the next. Although this scenario is of practical relevance, it has been poorly investigated in literature. For the present study, a water channel from the Fluids Engineering Laboratory was used. The pressure gradient, necessary for the bubble formation, was generated with a convergentdivergent plate and the level of disturbances in the boundary layer was controlled using a vibrating ribbon. Velocity fields in the bubble region were measured using the Particle Image Velocimetry technique with high temporal resolution. The generation of disturbances and measurements were phase locked, thus allowing the use of ensemble average techniques. The bubble was characterized in a so called steady regime, where there was no excitation of controlled disturbances upstream of the bubble. The results were compared with references in the literature, showing good agreement. In the transient regime, the flow was analyzed from the moment the disturbance generator was suddenly turned off until the bubble had completely recovered. In these conditions, it was noted that the bubble grew until reaching a length greater than that observed in the stationary regime. Only after the release of a large vortex did the bubble return to exhibit characteristics similar to those of the stationary regime. This behavior is similar to that reported in the literature for bubble rupture (bursting) but that is still not well understood.

Architectural and urban design for the reconversion of the part of the Old Brno (former textil fabric of the company Kras and surrounding areas) based on the existing structure of the Old Brno and ideas of compact city (mixing functions> multipurpose buildings, the divergence between private and public space, higher density of the city ...) The work consists of several parts: planning studies, design transportation solutions, waterfront Svratka concept and design for the multifunctional block on the waterfront. What is important is the idea of calming waterfront Svratka (sheltering services to the proposed tunnel and the cancellation of barrier between the city and the river). The waterfront district should become after more attractive location and provide a space for sport, recreation and afternoon walks. There is a block of multipurpose buildings on the waterfront. A corporate underground garage, which is under the block, should be build by a strong investor / city. After underground garage completion, the site will be divided into several parcels and these will be rented to various long-term investors .Tenants can build buildings on them according to their needs. It is possible to build buildings above the garage in sequence development. The project is just one of many options. Individual buildings are design in scale 1:200

No description available.

[pt] A união de materiais por soldagem é um dos processos mais utilizados na fabricação de estruturas. A soldagem traz maior confiabilidade, segurança ao projeto e resistência mecânica das uniões. Atualmente, diversas indústrias, tais como aeronáutica e automotiva, têm procurando utilizar materiais de baixa densidade e alta resistência mecânica, como as ligas de magnésio e de alumínio. Porém, estas ligas dificultam o processo de união através da soldagem convencional, que tem no seu principal fundamento a fusão do material, por possuírem baixa soldabilidade. Nas ligas de Mg e de Al há a formação uma camada de óxido que precisa ser removida durante o processo de soldagem, além de apresentarem grande susceptibilidade a geração de defeitos, tais como trincas e poros durante o processo de resfriamento da solda. A soldagem por fricção ou por mistura mecânica (FSW) foi desenvolvida como uma alternativa às técnicas de soldagem e uso mais comum existente na indústria, pois esta técnica elimina a fusão do material reduzindo, assim, os defeitos que surgiriam com a soldagem convencional. Por ser uma solda de estado sólido, tem a possibilidade de unir materiais dissimilares, polímeros, compósitos, ligas ferrosas e não ferrosas. O presente trabalho buscou avaliar parâmetros de soldagem variando a velocidade de soldagem (ν) e velocidade de rotação da ferramenta (ômega) utilizando uma ferramenta com rosca. Foram analisados o torque e as forças presentes no processo. Os resultados foram comparados com os resultados obtidos com uma ferramenta de soldagem sem rosca. A qualidade da solda foi correlacionada com os parâmetros de soldagem utilizados por meio de ensaios de dureza e tomografia. Foi concluído que a ferramenta com rosca gera defeito de túnel e demanda maior energia do processo em relação ao torque e à força axial. O comportamento das forças envolvidas no processo foi o mesmo para ambas as geometrias de ferramenta. A microdureza ao longo do eixo neutro mostrou a mudança entre a zona de mistura, zona termicamente afetada e o metal de base. / [en] The joining of materials by welding is the process most used in the fabrication of structures. Welding brings greater reliability, safety to the design and mechanical strength of the joints. Today, many industries, such as aeronautics and automotive, are looking to use low density and high mechanical strength materials such as magnesium and aluminum alloys. However, these alloys hinder the bonding process through conventional welding, which has in its main foundation the melting of the material, because they have low weldability. In Mg and Al alloys there is a layer of oxide that needs to be removed during the welding process, besides being very susceptible to the generation of defects, such as cracks and pores during the process of cooling the weld. Friction stir welding (FSW) was developed as an alternative to most commonly used in industry welding techniques, as this technique eliminates melting of the material thus reducing defects that would arise with conventional welding. To being a solid state weld, it has the possibility of joining dissimilar materials, polymers, composites, ferrous and non-ferrous alloys. The present work seeked to evaluate welding parameters by varying the welding speed (ν) and tool rotation (omega) using a threaded tool. The torque and forces were analyzed and the results will be compared with the results obtained with a threadless welding tool. The quality of the weld will be correlated with the welding parameters used by means of hardness test and tomography. It was concluded that the threaded tool generates tunnel defect and demands higher process energy. The behavior of the forces involved in the process was the same for both tool geometries. The microhardness along the neutral axis showed the clear the change between the mixing zone, thermally affected zone and the base metal.

[pt] Esta dissertação apresenta um resumo geral sobre as obras de construção do Túnel Milagres, escavado em rocha (filito), com extensão de 818 metros, entre os municípios de Salgueiro (PE) e Penaforte (CE). Este túnel faz parte do Projeto de Integração do São Francisco (PISF), em execução desde 2007, e com inauguração prevista para 2021. O trabalho aborda brevemente os métodos de classificação de maciços rochosos, os métodos de escavação de túneis e a importância da instrumentação geotécnica na execução desta obra. São estudadas seis seções instrumentadas da escavação do Túnel Milagres, avaliando-se os deslocamentos medidos por meio das convergências e os recalques. Observou-se que as medições de convergência e de recalque estão interligadas. Verificou-se, ainda, a estabilização das seções monitoradas após 60 dias. / [en] This dissertation presents a general summary on the excavation works of the Milagres Tunnel, excavated in rock (Phyllite), with an extension of 818 meters, between the municipalities of Salgueiro (PE) and Penaforte (CE). This tunnel is part of the São Francisco Transposition Project (PISF), under construction since 2007, and planned to be inaugurated in 2021. This work briefly addresses the classification methods of rocky masses, the tunneling excavation methods of and the importance of geotechnical instrumentation on this project. Six instrumented sections of the excavation of the Milagres Tunnel are evaluated, focusing at the measured values of convergence and displacements. It is observed that convergence and settlement measurements are interconnected. stabilization of the monitored sections was observed after 60 days has been noted.

En la realización de este trabajo se obtendrán las expresiones analíticas que permiten describir las propiedades acústicas de una red de elementos dispersivos en el interior de una guía de ondas, permitiendo así, obtener en el límite de homogenización los parámetros efectivos que caracterizan al metamaterial y la verificación experimental de las propiedades acústicas del metamaterial. Matemáticamente este problema se tratará con la teoría de la dispersión múltiple, ya que las geometrías a tratar en este trabajo van a ser cilíndricas y dicha teoría se ha demostrado ser la mas efectiva para esos casos y usando la técnica de ¿mode matching ¿para la resolución general del problema de la dispersión de campo acústico en el interior de una guía de ondas. / Graciá Salgado, R. (2014). Diseño y caracterización de metamateriales acústicos basados en guías de onda [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/38759 / TESIS

No description available.