This study researched the history of Space Shuttle Reusable Surface Insulation which was designed and developed for use on the United States Orbiter fleet to protect from the high heating experienced during reentry through Earth's atmosphere. Specifically the tile system which is attached to the structure by the means of an RTV adhesive has experienced situations where the bonds are identified as subnominal. The history of these subnominal conditions is presented along with a recent identification of a subnominal bond between the Strain Isolation Pad and the tile substrate itself. Tests were run to identify the cause of these subnominal conditions and also to show how these conditions were proved to be acceptable for flight. The study also goes into cases that could be used to identify subnominal conditions on tile as a non-destructive test prior to flight. Several options of non-destructive testing were identified and recommendations are given for future research into this topic. A recent topic is also discussed in the instance where gap fillers were identified during the STS-114 mission that did not properly adhere to the substrate. The gap fillers were found protruding past the Outer Mold Line of the vehicle which required an unprecedented spacewalk to remove them to allow for a safe reentry through the atmosphere.

No description available.

No description available.

Wearable and mobile devices are an important part of our daily life. Most of those devices are powered by batteries. The limited life span of batteries constitutes a limitation, especially in a multiple-day expedition, where electrical power can not access conveniently. At the same time, there is a huge amount of energy stored in the human body. While walking, there is a large amount of power dissipated in the human body as negative muscle work and the energy loss by impact. By sourcing locally and using locally, human body energy harvesting is a promising solution. This dissertation focuses on harvesting energy from the human body to power wearable and mobile devices while poses a minimum burden on the human body. Three topics related to the human body energy harvesting are explored, i.e, energy harvesting backpack, negative muscle work harvester, and energy harvesting tile/paver. The energy harvesting backpack was invented in 2006. Extensive work was done to improve the performance of backpack energy harvester. The backpack is modeled as a spring-mass-damper system. Mechanical Motion Rectifier was added to the spring-mass-damper system to increase the frequency bandwidth. A spring is added to the spring-mass-damper system, between the harvester and the backpack mass, and a inerter-based 2DOF (degree-of-freedom) backpack is created. The inerter-based 2DOF backpack improves the power output, frequency bandwidth, and power stroke ratio performance. MMR was added to the inerter-based 2DOF backpack to reduce the peak stroke. Compared with the conventional spring-mass-damper backpack, the MMR and inerter-based 2DOF backpack can harvest more power with large bandwidth at a small sacrifice of stroke. The electric damping was also tuned to increase the power output and bandwidth for the energy harvesting backpack. The negative work harvester mounts on the human ankle and harvests energy in the terminal stance phase in human walking, when the calf muscle is doing negative muscle work. This harvester is an analogy to regenerative brake in vehicles. The energy harvesting paver/tile harvests energy when the heel contacts with ground and energy are dissipated by impact. / Doctor of Philosophy / Wearable and mobile devices are an important part of our daily life. Most of those devices are powered by batteries. The limited life span of batteries constitutes a limitation, especially in a multiple-day expedition, where electrical power can not access conveniently. At the same time, there is a huge amount of energy stored in the human body. While walking, there is a large amount of power dissipated in the human body as negative muscle work and the energy loss by impact. By sourcing locally and using locally, human body energy harvesting is a promising solution. This dissertation focuses on harvesting energy from the human body to power wearable and mobile devices while poses a minimum burden on the human body. Three topics related to the human body energy harvesting are explored, i.e, energy harvesting backpack, negative muscle work harvester, and energy harvesting tile/paver. The energy harvesting backpack was invented in 2006. Extensive work was done to improve the performance of backpack energy harvester. The backpack is modeled as a spring-mass-damper system. Extensive work have been done to make the energy harvesting backpack broad frequency bandwidth. The negative work harvester mounts on the human ankle and harvests energy in the terminal stance phase in human walking. This harvester is an analogy to regenerative brake in vehicles. The energy harvesting paver/tile harvests energy when the heel contacts with ground and energy are dissipated by impact.

Le Modèle Standard (MS) de la physique des particules décrit les particules élémentaires et leurs interactions à l'exception de la gravité. Jusqu'à présent, la plupart des résultats expérimentaux sont en accord avec les prédictions du MS. Cependant, il existe encore des questions de nature expérimentale ou théorique qui restent sans réponse. Les particules massives qui se désintègrent en une paire de quarks top-antitop sont prédites par certains des modèles de physique au-delà du Modèle Standard, qui tentent de répondre à ces questions.Une recherche de nouvelles résonances tt est présentée dans ce manuscrit, en utilisant l'ensemble de données 2015 (début des Run 2) à partir des collisions proton-proton produites par le Large Hadron Collider (LHC) avec une énergie de faisceau de 13 TeV dans le centre de masse et avec une luminosité intégrée de 3.2 fb-1 recueillie par le détecteur ATLAS. La signature de l'état final recherché est caractérisée par la présence d'un électron ou d'un muon, d'un certain nombre de jets de hadrons et de l'énergie transverse manquante. La masse invariante des systèmes tt (mrecott ) est la principale observable sur cette recherche, et est utilisée pour tester la compatibilité des données avec l'hypothèse MS seule. Pour la région à grand mtt, les quarks top sont produits avec un grande impulsion et leurs produits de désintégration sont collimatés. Dans cette région, la sous-structure des jets doit être utilisée pour identifier les paires tt (scénario « boosted »), tandis que pour de basses valeurs de mtt, les produits de désintégration des quark top sont bien séparés (scénario « resolved »).Les résultats préliminaires sur l'analyse « boosted » sont présentés dans ce manuscrit. Dans les spectres de masse analysés, aucune preuve de l'existence de nouvelles particules n'a été trouvée. Pour une boson Z’TC2 « Topcolor assisted technicolor » avec une largeur relative de 1.2 %, des masses inférieures à 2 TeV sont exclues, l'améliorant les limites antérieures obtenues lors du Run 1. Des études de perspective pour inclure les topologies « resolved » sont également discutées, avec en particulier l'estimation du bruit de fond multi-jet en utilisant la « méthode de la matrice ». En outre, la méthode d'étalonnage des jets in-situ est proposée pour améliorer la résolution sur mtt. L'impact après chaque étape de la procédure de mise à l'échelle est présentée en utilisant des simulations à 8 TeV. / Massive particles decaying into a top-antitop pair (tt) are predicted by many theoretical models, which are introduced to provide explanations to the various open questions raised by the current formulation of the Standard Model of Particle Physics (SM). A search for new tt resonances is presented in this manuscript, using the 2015 dataset (early Run 2) from the proton-proton collisions at Large Hadron Collider (LHC) with a beam energy of 13 TeV at the centre-of-mass and with an integrated luminosity of 3.2 fb-1 collected by the ATLAS detector. The final state signature focuses on the lepton-plus-jets channel, which is characterised by the presence of an electron or muon, certain number of jets of hadrons and missing transverse energy. The invariant mass of the tt system (mtt) is the main observable on this search, which is used to test the compatibility of the data with the SM-only hypothesis. For the high mtt region, the selected events are dominated by top-quarks with collimated decay products, and jet substructure techniques have to be used to select the tt pairs (boosted scenario), while for low mtt, the selected events are dominated by top-quarks with well separated decay products (resolved scenario).Preliminary results on the boosted analysis are presented in this manuscript. In the analysed mass spectra, no evidence of the existence of new particles was found. For a topcolor-assisted technicolorZ’TC2 boson with a relative width of 1.2%, masses below 2 TeV are excluded, improving the previous limits obtained at Run 1. Perspective studies to include the resolved topologies are also discussed, where the estimation of the QCD multi-jet background using the « matrix method » is exposed in detail. In addition, the in-situ « jet rescaling » method is proposed to improve the mtt resolution. The impact after each step of the rescaling procedure is presented using 8 TeV simulations.

Submitted by Luciana Ferreira (lucgeral@gmail.com) on 2016-02-11T11:05:11Z No. of bitstreams: 2 Dissertação - Vinícius Gonçalves Braga - 2015.pdf: 9659356 bytes, checksum: 08fb0b3eae5f3af9311d9db5be529be4 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2016-02-11T11:06:52Z (GMT) No. of bitstreams: 2 Dissertação - Vinícius Gonçalves Braga - 2015.pdf: 9659356 bytes, checksum: 08fb0b3eae5f3af9311d9db5be529be4 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Made available in DSpace on 2016-02-11T11:06:52Z (GMT). No. of bitstreams: 2 Dissertação - Vinícius Gonçalves Braga - 2015.pdf: 9659356 bytes, checksum: 08fb0b3eae5f3af9311d9db5be529be4 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Previous issue date: 2015-11-10 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / Web mapping systems, or Web GIS, are important tools for geographic orientation and spatial data analysis. In recent years, the use of these systems has increased, as well as the challenge to ensure performance while the number of users and the data volume continue to grow. The performance evaluation is an important activity to investigate and mitigate systems performance issues. The workload is the starting point of the performance evaluation and is responsible for sending resquests to the system under evaluation. The reliability of the evaluation results is related to an appropriate load. Despite the importance of web map systems, the literature as presented little efforts to model the workload of these systems. In this dissertation, we present a methodology to collect and analyze data in order to create a model of Web GIS users’ behavior and to instantiate the model in a workload generator. We also propose a generic model, named MUSe-GM (Maps User Session Generative Model), and present a characterization of the users’ behavior using data of the access to a popular mapping application, collected by an extension developed for the Google Chrome browser. The characterization results were used to develop an instance of the behavior model and to implement a workload generator. The instance was evaluated by testing in a realWeb map system, using the workload generator, and through simulations. The results were compared with two other models from literature. The proposed model in this dissertation was significantly different in several aspects compared to the other, presenting a behavior closer to the real users’ behavior. / Sistemas de mapa Web, ou SIGs Web, são ferramentas importantes para orientação geográfica e análise de dados espaciais. Nos últimos anos, o uso desse tipo de sistema tem aumentado, bem como o desafio para garantir o desempenho frente ao aumento do número de usuários e do volume de dados. A avaliação de desempenho é uma importante atividade para investigar e mitigar problemas de desempenho em sistemas. O ponto inicial da avaliação de desempenho é a carga de trabalho, responsável por enviar requisições ao sistema sob avaliação. A confiabilidade dos resultados da avaliação depende de uma carga adequada. Apesar da importância dos sistemas de mapa Web, existem poucos esforços na literatura para modelar a carga de trabalho desse tipo de sistema. Nesta dissertação, apresentamos uma metodologia para coleta e análise de dados, visando a criação de um modelo do comportamento dos usuários de SIGs Web e sua instanciação em um gerador de cargas de trabalho. Propomos também um modelo genérico, chamado MUSe- GM (Maps User Session Generative Model), e apresentamos uma caracterização do comportamento dos usuários utilizando dados de acesso a um sistema de mapas popular, coletados a partir de uma extensão desenvolvida para o navegador Google Chrome. Os resultados da caracterização foram utilizados para a criação de uma instância do modelo de comportamento e na implementação de um gerador de cargas. A instância foi avaliada através de testes em um sistema de mapas real, utilizando o gerador de cargas, e por meio de simulações. Os resultados foram comparados aos de outros dois modelos da literatura. O modelo proposto nesta dissertação se mostrou significativamente diferente em vários aspectos em relação aos outros dois, apresentando um comportamento mais próximo do comportamento de usuários reais.

Agricultural management is essential for achieving optimum crop production and maintaining soil quality. Soil microorganisms are responsible for nutrient cycling and are an important consideration for effective soil management. The overall goal of the present research was to better understand microbial communities in agricultural soils as they relate to soil management practices. For this, we evaluated the differential impact of two contrasting drainage practices on microbial community composition and characterized active denitrifiers from selected agricultural sites. Field drainage is important for crop growth in arable soils. Controlled and uncontrolled tile drainage practices maintain water in the field or fully drain it, respectively. Because soil water content influences nutrient concentration, moisture, and oxygen availability, the effects of these two disparate practices on microbial community composition was compared in paired fields that had diverse land management histories. Libraries of the 16S rRNA gene were generated from DNA from 168 soil samples collected from eight fields during the 2012 growing season. Paired-end sequencing using next-generation sequencing was followed by read assembly and multivariate statistical analyses. Results showed that drainage practice exerted no measureable effect on the bacterial communities. However, bacterial communities were impacted by plant cultivar and applied fertilizer, in addition to sampled soil depth. Indicator species were only recovered for depth; plant cultivar or applied fertilizer type had no strong and specific indicator species. Among indicator species for soil depth (30-90 cm) were Chloroflexi (Anaerolineae), Betaproteobacteria (Janthinobacterium, Herminiimonas, Rhodoferax, Polaromonas), Deltaproteobacteria (Anaeromyxobacter, Geobacter), Alphaproteobacteria (Novosphingobium, Rhodobacter), and Actinobacteria (Promicromonospora). Denitrification in agricultural fields transforms nitrogen applied as fertilizer, reduces crop production, and emits N2O, which is a potent greenhouse gas. Agriculture is the highest anthropogenic source of N2O, which underlines the importance of understanding the microbiology of denitrification for reducing greenhouse gas emissions by altered management practices. Existing denitrifier probes and primers are biased due to their development based mostly on sequence information from cultured denitrifiers. To circumvent this limitation, this study investigated active and uncultivated denitrifiers from two agricultural sites in Ottawa, Ontario. Using DNA stable-isotope probing, we enriched nucleic acids from active soil denitrifiers by exposing intact replicate soil cores to NO3- and 13C6-glucose under anoxic conditions using flow-through reactors, with parallel native substrate controls. Spectrophotometric chemistry assays and gas chromatography confirmed active NO3- depletion and N2O production, respectively. Duplicate flow-through reactors were sacrificed after one and four week incubation periods to assess temporal changes due to food web dynamics. Soil DNA was extracted and processed by density gradient ultracentrifugation, followed by fractionation to separate DNA contributed by active denitrifiers (i.e., “heavy” DNA) from that of the background community (i.e., “light” DNA). Light and heavy DNA samples were analyzed by paired-end sequencing of 16S rRNA genes using next-generation sequencing. Multivariate statistics of assembled 16S rRNA genes confirmed unique taxonomic representation in heavy fractions from flow-through reactors fed 13C6-glucose, which exceeded any site-specific or temporal shifts in putative denitrifiers. Based on high relative abundance in heavy DNA, labelled taxa affiliated with the Betaproteobacteria (71%; Janthinobacterium, Acidovorax, Azoarcus, Dechloromonas), Alphaproteobacteria (8%; Rhizobium), Gammaproteobacteria (4%; Pseudomonas), and Actinobacteria (4%; Streptomycetaceae). Metagenomic DNA from the original soil and recovered heavy fractions were subjected to next-generation sequencing and the results demonstrated enrichment of denitrification genes with taxonomic affiliations to Brucella, Ralstonia, and Chromobacterium in heavy fractions of flow-through reactors fed 13C6-glucose. The vast majority of heavy-DNA-associated nitrite-reductase reads annotated to the copper-containing form (nirK), rather than the heme-containing enzyme (nirS). Analysis of recovered nirK genes demonstrated low sequence identity across common primer-binding sites used for the detection and quantification of soil denitrifiers, indicating that these active denitrifiers would not have been detected in molecular surveys of these same soils.

Made available in DSpace on 2017-07-21T20:42:41Z (GMT). No. of bitstreams: 1 Edney Melo Neves.pdf: 2401483 bytes, checksum: 62f3e20bc1f9efd71b600800871b29fc (MD5) Previous issue date: 2013-08-28 / This work aims to investigate the incorporation of waste lime mud, generated by the pulp industry, in the formulations of the porous ceramic body in substitution the raw material calcite. The experiments covered the physico-chemical and mineralogical of the raw materials, the waste, and the compositions proposals. It was verified that the residue has the carbonate content slightly larger than the calcite, a larger average particle size and similar thermal properties. The ceramic bodies studied were prepared by the wet process, conformed by uniaxial pressing and sintered in an industrial furnace at 1135 °C and laboratory at temperatures of 1115 °C, 1125 °C, 1135 °C and 1145.°C with sintering cycle fast. Then, technological tests were carried total shrinkage, absorption of water, loss on ignition, mechanical strength and colorimetric coordinate. It was observed that, with the increase in substitution of calcite for the residue lime mud, the total shrinkage test samples decreased, while increasing the dimensional stability. Thus, other formulations have been proposed with the objective of keeping the shrinkage closest to standard composition. Compositions were selected, tested and characterized by differential thermal analysis and thermogravimetryc analysis, dilatometry and microstructure analysis of the fracture of the sintered specimens. The results shown to be possible to use waste "lime mud" in wall tiles compositions as a substitute for raw material calcite, keeping requirements of the NBR 13818, and with the advantage of reducing the percentage of carbonates in the composition, increased dimensional stability during sintering, lighten the color of ceramic body, addition to being an environmental solution. / Este trabalho tem por objetivo investigar a incorporação do resíduo “lama de cal”, gerado pela indústria de celulose, nas formulações de massa cerâmica de revestimento poroso em substituição a matéria-prima calcita tradicional. Os experimentos abrangeram a caracterização físico-química e mineralógica das matérias-primas, do resíduo e das composições propostas. Verificou-se que o resíduo possui o teor de carbonatos ligeiramente maior que a calcita tradicional, um maior tamanho médio de partículas, e propriedades térmicas semelhantes. As massas cerâmicas estudadas foram preparadas pelo processo via úmida, conformada por prensagem uniaxial e sinterizadas em forno industrial a 1135 °C e de laboratório nas temperaturas de 1115.°C, 1125 °C, 1135 °C e 1145 °C em ciclo de sinterização rápido. Em seguida, foram realizados os ensaios tecnológicos de retração total, de absorção de água, de perda ao fogo, de resistência mecânica e de coordenada colorimétrica. Constatou-se que, conforme o aumento da substituição da calcita tradicional pelo resíduo “lama de cal”, a retração total dos corpos de provas diminuiu, além de aumentar a estabilidade dimensional. Assim, foram propostas outras formulações com o objetivo de manter a retração próxima a composição padrão. Selecionaram-se composições e realizaram-se os ensaios de análise térmica diferencial e termogravimétrica, dilatometria, e análise da microestrutura da fratura dos corpos de prova sinterizados. Os resultados revelaram ser possível o uso do resíduo “lama de cal” em composições de monoporosa como substituto da matéria-prima calcita tradicional, mantendo os requisitos exigidos pela NBR 13818, e com as vantagens de redução do percentual de carbonatos na composição, aumento da estabilidade dimensional durante a sinterização, clarear a cor da massa, além de ser uma solução ambiental.

<p>To be able to run a flight simulator a large area of terrain needs to be visualized. The simulator must update the screen in real-time to make the simulation work well. One way of managing large terrains is to tile the area into quadratic tiles to be able to work with different detailed representations of the terrain at different distances from the user. The tiles need to match with the adjacent tiles in the edge points to avoid cracks. When every tile can have a number of different levels of detail this means that the different levels of detail need to match too. This was previously done by having the same edge points in all levels of detail, giving an unnicessarily large polygon count in the less detailed levels. the method developed in this report uses different versions of borders with their own level of detail, adapting to different detail levels at the adjacent tile, reducing hte number of polygons.</p>

Fiber reinforced polymers (FRPs) have gained popularity in upgrade projects for reinforced concrete structural elements within the last decade because of its ease of application and high strength-to-weight ratio. In the design of an effective retrofitting solution by means of an FRP system, the anchorage capacity has an important role. This study presents the results of an experimental program conducted to determine the strength of carbon fiber reinforced polymers (CFRPs) bonded to concrete prisms or hollow clay tiles that are finished with or without plaster. In the experimental program, different types of anchorage methods were tested in a double shear push-out test setup. A simple and effective strength model is proposed for strip type anchorages based on the existing analytical models and experimental observations from this study. This new model is suitable for determining the design capacity of CFRP-to-concrete and CFRP-to- hollow clay tile joints with or without plaster and accounts for the presence of embedment and concrete strength. Obtained results by using this model were found to closely match with the experimental observations.