587 resultados para Prestressing Strands
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Precast prestressed concrete panels have been used in bridge deck construction in Iowa and many other states. To investigate the performance of these panels at abutment or pier diaphragm locations for bridges with various skew angles, a research program involving both analytical and experimental aspects, is being conducted. This interim report presents the status of the research with respect to four tasks. Task 1 which involves a literature review and two surveys is essentially complete. Task 2 which involved field investigations of three Iowa bridges containing precast panel subdecks has been completed. Based on the findings of these investigations, future inspections are recommended to evaluate potential panel deterioration due to possible corrosion of the prestressed strands. Task 3 is the experimental program which has been established to monitor the behavior of five configurations of full scale composite deck slabs. Three dimensional test and instrumentation frameworks have been constructed to load and monitor the slab specimens. The first slab configuration representing an interior panel condition is being tested and preliminary results are presented for one of these tests in this interim report. Task 4 involves the analytical investigation of the experimental specimens. Finite element methods are being applied to analytically predict the behavior of the test specimens. The first test configuration of the interior panel condition has been analyzed for the same loads used in the laboratory, and the results are presented herein. Very good correlation between the analytical and experimental results has occurred.
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A report developed for the Department of Health by the institute of Public Health in Ireland. This report presents a summary of the feedback of key stakeholders based on a consultation document presenting options for action to address Ireland’s overweight and obesity epidemic. There was a very significant level of engagement by a wide range of stakeholders which has resulted in a useful set of considerations for policy development. The findings from this consultation strand along with those from the other two strands of consultation will be studied to inform and enrich the forthcoming Obesity Policy and Action Plan.
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Le byssus est un amas de fibres que les moules produisent afin de s’ancrer aux surfaces immergées sous l’eau. Ces fibres sont pourvues de propriétés mécaniques impressionnantes combinant rigidité, élasticité et ténacité élevées. De plus, elles possèdent un comportement d’auto-guérison de leurs propriétés mécaniques en fonction du temps lorsque la contrainte initialement appliquée est retirée. Les propriétés mécaniques de ces fibres sont le résultat de l’agencement hiérarchique de protéines de type copolymère blocs riches en collagène et de la présence de métaux formant des liens sacrificiels réversibles avec certains acides aminés comme les DOPA et les histidines. Bien que cette fibre soit très intéressante pour la production de matériaux grâce à son contenu élevé en collagène potentiellement biocompatible, cette ressource naturelle est traitée comme un déchet par les mytiliculteurs. L’objectif de cette thèse était de valoriser cette fibre en extrayant les protéines pour générer une nouvelle classe de matériaux biomimétiques. Un hydrolysat de protéines de byssus (BPH) riche en acides aminés chargés, i.e. ~30 % mol, et permettant de former des films a pu être généré. Lorsque solubilisé à pH 10.5, le BPH forme un hydrogel contenant des structures en triple hélice de collagène et des feuillets β anti-parallèles intra- et inter-moléculaires. Suite à l’évaporation de l’eau, le film de BPH résultant est insoluble en milieu aqueux à cause des structures secondaires très stables agissant comme points de réticulation effectifs. Les propriétés mécaniques des films de BPH sont modulables en fonction du pH. Au point isoélectrique (pI = 4.5), les interactions électrostatiques entre les charges opposées agissent comme points de réticulation et augmentent la rigidité des films et leur contrainte à la rupture sans affecter la déformation à la rupture. À pH plus élevé ou plus bas que le pI, les performances mécaniques des films sont plus faibles à cause de la répulsion entre les groupements fonctionnels de même charge qui interagissent plutôt avec les molécules d’eau et causent le gonflement de la matrice protéique des films. Le BPH contenant un nombre élevé d’acides aminés chargés et réactifs, nous avons pu réticuler les films de manière covalente à l’aide d’EDC ou de glutaraldéhyde. Les propriétés mécaniques des films sont modulables en fonction de la concentration d’EDC utilisée lors de la réticulation ou en employant du glutaraldéhyde comme agent réticulant. Les films sont à la fois plus rigides et plus forts avec un degré de réticulation élevé, mais perdent leur extensibilité à mesure que les segments libres de s’étirer lors d’une traction deviennent entravés par les points de réticulation. La réticulation augmente également la résistance à la dégradation enzymatique par la collagénase, les films les plus fortement réticulés lui étant pratiquement insensibles. La spectroscopie infrarouge montre enfin que la réticulation entraîne une transition de feuillets β anti-parallèles inter-moléculaires vers des structures de type hélices de collagène/PPII hydratées. Des liens sacrificiels ont été formés dans les films de BPH par traitement au pI et/ou avec différents métaux, i.e. Na+, Ca2+, Fe3+, afin de moduler les propriétés mécaniques statiques et d’évaluer le rôle de ces traitements sur le comportement d’auto-guérison lors de tests mécaniques cycliques avec différents temps de repos. Plus la valence des ions métalliques ajoutés augmente, plus les propriétés mécaniques statiques affichent un module, une contrainte à la rupture et une ténacité élevés sans toutefois affecter la déformation à la rupture, confirmant la formation de liens sacrificiels. Les tests mécaniques cycliques montrent que les traitements au pI ou avec Ca2+ créent des liens sacrificiels ioniques réversibles qui mènent à un processus d’auto-guérison des performances mécaniques dépendant du pH. L’ajout de Fe3+ à différentes concentrations module les performances mécaniques sur un plus large intervalle et la nature plus covalente de son interaction avec les acides aminés permet d’atteindre des valeurs nettement plus élevées que les autres traitements étudiés. Le Fe3+ permet aussi la formation de liens sacrificiels réversibles menant à l’auto-guérison des propriétés mécaniques. Les spectroscopies Raman et infrarouge confirment que le fer crée des liaisons avec plusieurs acides aminés, dont les histidines et les DOPA. Les résultats dans leur ensemble démontrent que les films de BPH sont des hydrogels biomimétiques du byssus qui peuvent être traités ou réticulés de différentes façons afin de moduler leurs performances mécaniques. Ils pourraient ainsi servir de matrices pour des applications potentielles dans le domaine pharmaceutique ou en ingénierie tissulaire.
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Esta investigação debruça-se sobre a análise do Combate ao Analfabetismo em Angola e o processo de alfabetização levado a cabo pelo Estado e os Parceiros Sociais no meio rural, desde o Acordo de paz em 2002, e especificamente, sobre dos Programas, Estratégias e Planos de Alfabetização do Estado, no contexto do Sistema de Educação, preconizados nesse período. Em Angola a maior parte das ações de alfabetização são asseguradas pelos parceiros sociais do Estado, pelo que procedemos à identificação das Organizações, Associações Nacionais e Organizações Internacionais em processos de Alfabetização e aos Métodos de Alfabetização associados ao Plano Estratégico para a Revitalização da Alfabetização (2012). Os constrangimentos ao processo de alfabetização no meio rural foram analisados em três vertentes: do acesso à educação e alfabetização de jovens e adultos; dos professores e alfabetizadores, sua formação, recrutamento e fixação, e o da utilização da Língua Oficial e das Línguas Nacionais. A investigação teve por base uma metodologia do tipo qualitativo assente na recolha e análise bibliográfica e documental, constituindo um estudo interpretativo fruto de uma Revisão Bibliográfica Narrativa. A gratuitidade, a equidade e a qualidade do ensino em Angola, enquanto objetivos primordiais dos principais documentos reitores do Sistema de Educação, não estão a ser asseguradas ou cumpridas com a amplitude e a eficácia pretendidas. Não obstante as estratégias, os programas e os planos de alfabetização concebidos após 2002, a sua implementação não tem conseguido materializar-se enquanto instrumento facilitador de uma “segunda oportunidade” educativa para jovens e adultos analfabetos. Perpetuam-se problemas no acesso ao ensino no meio rural, particularmente no que respeita à gratuidade, aos fracos apoios e incentivos financeiros do Estado e à insuficiente aplicação de políticas de ação social escolar. Persistem também a escassez de professores e alfabetizadores, as suas dificuldades de caracter formativo e profissional, a limitação de recursos de que dispõem e de incentivos que os levem a fixar-se. A utilização das línguas maternas não se efetiva no processo ensino-aprendizagem, onde a sua pertinência é maior devido à identidade bantu das populações. Estes constrangimentos repercutem-se no insucesso escolar dos alunos e no aumento das taxas de abandono/desistência e comprometem o direito à educação. Apesar do esforço nacional, a afetação de recursos do orçamento destinado ao sector da educação, ao combate ao analfabetismo e à alfabetização de jovens e adultos é ainda inferior a metade do recomendado internacionalmente nesta área. / This study focuses on the analysis of the struggle against Illiteracy in Angola and on the literacy process undertaken by the State and the Social Partners in the rural areas, since the Peace Agreement in 2002, and specifically on the Programs, Strategies and Plans of Literacy of the State in the context of the Education System proclaimed on that period. In Angola most literacy actions are ensured by the social partners of the State, therefore we proceed to identify the Organizations, National Associations and International Organizations in processes of Literacy and the Methods of Literacy associated to the Strategic Plan for the Revitalization of Literacy(2012). The constraints on the process of literacy in rural areas were analyzed in three strands: the access to education and literacy for young people and adults; the teachers and literacy teachers, their school formation, recruitment and fixation, and the use of the Official Language and the National Languages. The study used a qualitative methodology based on bibliographic and documentary collection and analysis, constituting an interpretative study, which is the result of a bibliographic narrative review. Free, equal and quality education in Angola as primary objectives of the main guiding documents of the Education System, are not being provided or accomplished with the scope and effectiveness required. Despite the Strategies, the Programs and the Literacy Plans designed after 2002, its implementation has not been able to be materialized as a facilitator of a "second chance" education for young people and adult illiterates. Problems remain in the access to education in rural areas, particularly, as far as free education, weak support and financial incentives from the State and inadequate implementation of the policies of school social work are concerned. The shortage of teachers and literacy teachers, the difficulties related to their training and their profession, the limited resources available and incentives that lead them to settle down also persist. The use of the mother tongues is not effective in the teaching-learning process, where its pertinence is greater due to the bantu identity of the populations. These constraints have repercussions on the students' school failure and on the abandonment rates increase and compromise the right to education. Despite the national effort, the allocation of budget resources intended for the education sector, to fight illiteracy and to improve young people and adults’ literacy, is still less than half of the recommended internationally in this area.
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Abstract Mandevillian intelligence is a specific form of collective intelligence in which individual cognitive vices (i.e., shortcomings, limitations, constraints and biases) are seen to play a positive functional role in yielding collective forms of cognitive success. In this talk, I will introduce the concept of mandevillian intelligence and review a number of strands of empirical research that help to shed light on the phenomenon. I will also attempt to highlight the value of the concept of mandevillian intelligence from a philosophical, scientific and engineering perspective. Inasmuch as we accept the notion of mandevillian intelligence, then it seems that the cognitive and epistemic value of a specific social or technological intervention will vary according to whether our attention is focused at the individual or collective level of analysis. This has a number of important implications for how we think about the cognitive impacts of a number of Web-based technologies (e.g., personalized search mechanisms). It also forces us to take seriously the idea that the exploitation (or even the accentuation!) of individual cognitive shortcomings could, in some situations, provide a productive route to collective forms of cognitive and epistemic success. Speaker Biography Dr Paul Smart Paul Smart is a senior research fellow in the Web and Internet Science research group at the University of Southampton in the UK. He is a Fellow of the British Computer Society, a professional member of the Association of Computing Machinery, and a member of the Cognitive Science Society. Paul’s research interests span a number of disciplines, including philosophy, cognitive science, social science, and computer science. His primary area of research interest relates to the social and cognitive implications of Web and Internet technologies. Paul received his bachelors degree in Psychology from the University of Nottingham. He also holds a PhD in Experimental Psychology from the University of Sussex.
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Beginning with Montaigne’s essayistic dictum Que sais je? — ‘What do I know?’ — this PhD thesis examines the literary history, formal qualities, and theoretical underpinnings of the personal essay to both investigate and to practice its relevance as an approach to writing about art. The thesis proposes the essay as intrinsically linked to research, critical writing, and art making; it is a literary method that embodies the real experience of attempting to answer a question. The essay is a processual and reflexive mode of enquiry: a form that conveys not just the essayist’s thought, but the sense and texture of its movement as it attempts to understand its object. It is often invoked, across disciplines, in reference to the possibility of a more liberal sense of creative practice — one that conceptually and stylistically privileges collage, fragmentation, hybridity, chance, open-endedness, and the meander. Within this question of the essay as form, the thesis contains two distinct and parallel strands of analysis — subject matter and essay writing as research. At the core of the study lie two close-readings: Ana Mendieta’s Labyrinth of Venus (1982) and Le Couvent de la Tourette (1959) by Le Corbusier and Iannis Xenakis. In each case, the writing draws, in its tone and texture, on a range of literary influences, weaving together different voices, discussions, and approaches to enquiry. The practice of essay writing is presented alongside, part and party to, research: a method of interrogation that embraces risk and uncertainty, and simultaneously enacts its own findings as a critical-creative mode of study-via-form, and form-via-study. The thesis is presented as a book-length essay, in which the art in question is equal and intimately connected to the writing used to address it. Method and form are designed to respond to the oft-cited challenge of the essay as fundamentally unmethodical, ranging, and diverse. Research, critical study, writerly description, and storytelling are combined to elucidate and expose each other based not on surface continuity, but on a deep interconnection among ideas that, through language, cohere and become related — imbued with an affinity for one another. The consummate product is the argument, as it works across genres, disciplines, descriptive and critical models, to challenge the narrative structure and language used within contemporary writing about art.
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Thesis (Ph.D.)--University of Washington, 2016-06
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Thesis (Ph.D.)--University of Washington, 2016-08
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Trabalho de Projeto para obtenção do grau de Mestre em Engenharia Civil na Área de Especialização em Estruturas
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The purpose of this study is to understand, impact and evaluate the development of intercultural communicative competencies among European credit-seeking exchange students and other sojourners through purposeful intercultural pedagogy. This pedagogy encompasses intentional intercultural- educational approaches which aim to support and enhance sojourners’ intercultural learning throughout the study abroad cycle (pre-departure, in-country and reentry phases). To test and validate these pedagogies a 20-hour intervention was designed and implemented among two cohorts of 31 sojourners during the in-country phase of their sojourn in Portugal. The process to develop and validate the intercultural intervention was driven by a mixed-methods methodology which combined quantitative and qualitative data to triangulate, complement and expand research results from a pragmatic stance. The mixed methods research design adopted is multi-phased and encompasses a multi-case study and an evaluative component. The multi-case component is embodied by sojourner cohorts: (1) the primary case study involves 19 incoming students at the University of Aveiro (Portugal) as participants in the European exchange program Campus Europae; (2) the second case study comprises three incoming Erasmus students and nine highly skilled immigrants at the same university. All 31 sojourners attended two intermediate Portuguese as Foreign Language classrooms where the intervention was employed. Data collection was extensive and involved collecting, analyzing and mixing quantitative and qualitative strands across four research phases. These phases refer to the: (1) development, (2) implementation and (3) evaluation of the intervention, as well as to (4) a stakeholder analysis of the external value of the intervention and of the Campus Europae program. Data collection instruments included pre and posttest questionnaires and semi-structured interviews. Results confirm the intercultural effectiveness of the intervention and the positive impact upon research participants’ intercultural gains. This impact was, however, greater in case study 2. Among explanatory variables, three stand out: (1) participant meaning-making abilities, (2) host language proficiency and related variables, and (3) type of sojourn or exchange programs. Implications for further research highlight the need to systematize purposeful intercultural pedagogy in sojourner populations in general, and in European credit student mobility in particular. In the latter case, these pedagogies should be part of the design and delivery of credit-bearing exchange programs in pre- departure, in-country and re-entry phases. Implications for practice point to the urge to improve intercultural practices in: macro (higher education institutions), mezzo (exchange programs) and micro (sojourner language classrooms) contexts where this research took place, and wider social scenarios they represent.
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Interactions of the cationic lipodepsipeptide syringopeptin 25 A (SP25A) with mercury-supported dioleoylphosphatidylcholine (DOPC), dioleoylphosphatidylserine (DOPS) and dioeleoylphosphatidic acid (DOPA) self-assembled monolayers (SAMs) were investigated by AC voltammetry in 0.1 M KCl at pH 3, 5.4 and 6.8. SP25A targets and penetrates the DOPS SAM much more effectively than the other SAMs not only at pH 6.8, where the DOPS SAM is negatively charged, but also at pH 3, where it is positively charged just as SP25A. Similar investigations at tethered bilayer lipid membranes (tBLMs) consisting of a thiolipid called DPTL anchored to mercury, with a DOPS, DOPA or DOPC distal monolayer on top of it, showed that, at physiological transmembrane potentials, SP25A forms ion channels spanning the tBLM only if DOPS is the distal monolayer. The distinguishing chemical feature of the DOPS SAM is the ionic interaction between the protonated amino group of a DOPS molecule and the carboxylate group of an adjacent phospholipid molecule. Under the reasonable assumption that SP25A preferentially interacts with this ion pair, the selective lipodepsipeptide antimicrobial activity against Gram-positive bacteria may be tentatively explained by its affinity for similar protonated amino-carboxylate pairs, which are expected to be present in the peptide moieties of peptidoglycan strands.
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Os microRNAs (miRNAs) são curtas cadeias de RNA não codificante, com cerca de 18 a 25 nucleotídeos, que regulam os níveis de mRNAs que são produzidos a partir de genes codificantes de proteínas. A descoberta dos miRNAs e a sua subsequente caracterização estrutural e funcional revelou a existência de um novo processo de regulação pós-transcricional da expressão génica em células eucarióticas que afeta uma grande variedade de funções celulares. A senescência acompanha o processo de evelhecimento dos organismos e é manifestada pela perda da capacidade proliferativa das células em resposta a diversos fatores de stress que desencadeiam alterações moleculares específicas. Na última década foram identificados e caracterizados vários miRNAs que participam na regulação do fenótipo da senescência celular, quer através da modulação de vias de sinalização endógenas que controlam a progressão do ciclo celular, quer através da secreção de factores de sinalização. Vários estudos têm também revelado a enorme potencialidade dos miRNAs como biomarcadores e alvos moleculares de novas abordagens terapêuticas. No futuro, é expectável que os avanços científicos possam ser transferidos para a prática clínica com vista a uma efetiva prevenção, vigilância e tratamento do envelhecimento prematuro e de doenças associadas ao envelhecimento.
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A presente investigação propõe-se a atuar no sector turístico, uma vez que este é bombardeado diariamente por uma quantidade considerável de dados e informações. Atualmente, usufrui-se significativamente mais da tecnologia com a finalidade de promover e vender os produtos/serviços disponíveis no mercado. A par da evolução tecnológica, os utilizadores/clientes conseguem comprar, cada vez mais, à distancia de um clique os produtos turísticos que desejam. No entanto, há um variado leque de aplicações sobre o turismo que permitem entender os gostos e as necessidades dos turistas assim como a sua atitude para com o mesmo. Porém, nem as entidades nem os gestores turísticos usufruem inteligentemente dos dados que lhes são facultados. Estes tendem normalmente a prender-se pelo turismo em Portugal e de que forma é que a sua entidade é apresentada acabando por esquecer que os dados podem e devem ser utilizados para expandir o mercado assim como entender/conhecer potenciais mercados. Deste modo, o fundamento principal desta investigação remete para a criação de uma plataforma infocomunicacional que analise na totalidade os dados obtidos, assim como fornecer as ferramentas pertinentes para que se consiga fazer esta análise, nomeadamente através de uma representação infográfica adequada e estratégias de a comunicar aos stakeholders.. Para tal foi aplicada no âmbito desta dissertação a metodologia investigação/ação, vista como um processo cíclico que para além de incluir simultaneamente estas duas vertentes, vai alternando entre a ação e a reflexão critica sendo sustentada por bases teóricas. A criação do protótipo da plataforma Smart Tourism, resultou num sistema inovador que tenta responder aos indicadores escolhidos no Dashbord e ao problema infocomunicacional, tentando criar as bases necessárias para que as entidades consigam analisar de forma mais integrada/sistematizada e racional a atividade turística. Foi por isso, desenvolvido e avaliado qualitativamente um protótipo de base infocomunicacional visual (dashboard visual) que para além do que para além do que já foi referido, consegue proporcionar a gestão dos produtos, clientes, staff e parceiros, aumentando assim o valor deste sector.
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O presente Trabalho Final de Mestrado consiste na elaboração de um Estudo Prévio de um viaduto rodoviário, em betão armado pré-esforçado. O viaduto, com tabuleiro em laje vigada, é constituído por 10 tramos, prevendo-se que seja construído tramo a tramo, com juntas de betonagem a quintos de vão. A plataforma do viaduto é constituída por duas vias de tráfego com 3.5m cada, duas bermas de 1.00 m e dois passeios laterais com 1.10 m cada, perfazendo uma largura total de 11.20. O viaduto localiza-se em Polónia e foi dimensionado de acordo com os Eurocódigos e os Anexos Nacionais desse país.
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The second generation of large scale interferometric gravitational wave (GW) detectors will be limited by quantum noise over a wide frequency range in their detection band. Further sensitivity improvements for future upgrades or new detectors beyond the second generation motivate the development of measurement schemes to mitigate the impact of quantum noise in these instruments. Two strands of development are being pursued to reach this goal, focusing both on modifications of the well-established Michelson detector configuration and development of different detector topologies. In this paper, we present the design of the world's first Sagnac speed meter (SSM) interferometer, which is currently being constructed at the University of Glasgow. With this proof-of-principle experiment we aim to demonstrate the theoretically predicted lower quantum noise in a Sagnac interferometer compared to an equivalent Michelson interferometer, to qualify SSM for further research towards an implementation in a future generation large scale GW detector, such as the planned Einstein telescope observatory.