História da botânica em Portugal até finais do século XIX

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Diffusion measurements in liquid mixtures by Raman spectroscopy

Tese de mestrado integrado. Engenharia Química. Faculdade de Engenharia. Universidade do Porto, Department of Chemical Technology. Lappeenranta University of Technology. 200

Emission line taxonomy and the nature of AGN-looking galaxies in the SDSS

Massive spectroscopic surveys like the SDSS have revolutionized the way we study AGN and their relations to the galaxies they live in. A first step in any such study is to define samples of different types of AGN on the basis of emission line ratios. This deceivingly simple step involves decisions on which classification scheme to use and data quality censorship. Galaxies with weak emission lines are often left aside or dealt with separately because one cannot fully classify them onto the standard Star-Forming, Seyfert of LINER categories. This contribution summarizes alternative classification schemes which include this very numerous population. We then study how star-formation histories and physical properties of the hosts vary from class to class, and present compelling evidence that the emission lines in the majority of LINER-like systems in the SDSS are not powered by black-hole accretion. The data are fully consistent with them being galaxies whose old stars provide all the ionizing power needed to explain their line ratios and luminosities. Such retired galaxies deserve a place in the emission line taxonomy.Comment: 8 pages, 4 figures, Proceedings of IAU Symposium 267, Co-Evolution of Central Black Holes and Galaxie

SketchyDynamics apoio à produção de sistemas baseados em interfaces caligráficas para a simulação da dinâmica de corpos rígidos

Mestrado em Engenharia Informática - Área de Especialização em Sistemas Gráficos e MultimédiaO paradigma de interação proporcionado pelas interfaces caligráficas constitui uma forma natural de interação humano-computador. Esta naturalidade deve-se, sobretudo, à semelhança que este estilo de interação possui com a utilização de um lápis sobre papel, tarefa comum e intuitiva. Apesar disso é ainda pouco frequente o emprego de tais interfaces em aplicações informáticas, sendo o estilo de interação WIMP (Windows, Icons, Menus and Pointers) mais utilizado e favorecido. No entanto, antecipa-se um futuro no qual as interfaces caligráficas estarão cada vez mais presentes, pois é notório o surgimento de um número crescente não só de aplicações que adotam este estilo de interação, mas também de equipamentos que incentivam à sua utilização. Com base nesta premissa, é seguro afirmar a necessidade de investir nesta área, de modo a agilizar e acelerar a adoção do estilo de interação caligráfico e, assim, tornar a interação humano-computador num processo cada vez mais natural. O trabalho descrito neste documento visa um estudo à utilização das interfaces caligráficas orientada para a criação e controlo de um ambiente simulado. Mais concretamente, é apresentado o sistema SketchyDynamics, que integra um módulo de simulação da dinâmica de corpos rígidos em simbiose com uma interface caligráfica munida das ações necessárias para a manipulação da simulação. Recorrendo a este sistema, é facilitada a produção de aplicações que tirem partido destas funcionalidades, sem a necessidade de as reimplementar. É ainda descrita uma avaliação de técnicas de reconhecimento caligráfico realizada com o objetivo de determinar aquela que melhor se integraria no sistema desenvolvido. No âmbito desta avaliação são ainda apresentados alguns pormenores sobre a implementação dessas técnicas, bem como procedimentos que permitem uma maximização da sua eficácia. São também discutidos os resultados de uma avaliação de usabilidade conduzida com o propósito de validar o sistema SketchyDynamics do ponto de vista do utilizador. Os resultados desta avaliação mostram que este sistema foi bem-sucedido e que se encontra preparado para o utilizador final, não obstante a existência de margem para futuras melhorias.The interaction paradigm provided by sketch-based interfaces represents a natural method of human-computer interaction. This naturalness is largely due to the similarity that this interaction style has with the use of a pencil on a paper, an intuitive and common task. Despite that, the implementation of these interfaces on computer applications is still unusual, in favor of the WIMP (Windows, Icons, Menus and Points) interaction style. Nevertheless, we can predict a future where sketch-based interfaces will be increasingly more widespread, based on the recent emergence of not only applications that adopt this interaction style, but also equipment that encourage their use. With this premise in mind, it is safe to assert the need for investment in this area, in order to streamline and accelerate the adoption of the sketch-based interaction style and thus make the human-computer interaction a progressively more natural process. The work described in this document aims the study of the use of sketch-based interfaces in the creation and control of simulated environments. More specifically, we present the SketchyDynamics system, which incorporates a rigid body simulation module in symbiosis with a sketch-based interface provided with the necessary actions for the manipulation of the simulation. Using this system, we hope to ease the production of applications that take advantage of these features, without the need to implement them from scratch. An evaluation of various sketch recognition techniques, performed in order to find the one that best fits in the developed system, is also described. As part of this evaluation, we also present some details on the implementation of these techniques, as well as procedures that allow us to maximize their efficiency. Furthermore, we discuss the results of a usability evaluation that was conducted with the purpose of validating the SketchyDynamics system from the user’s point of view. The results of this evaluation suggest that, despite the existence of room for further improvements, the system was successful and is ready for final users

Ultra-low-cycle fatigue of pipeline steels

PING 2019 is organized with the support of funds for specific university research project SVK1-2019-002.Pipelines and piping components when subjected to extreme loading conditions (e.g. earthquakes, hurricanes, support settlements, industrial plant shutdown) undergo large plastic deformations, associated with widespread yielding, leading to fracture, either due to monotonic loading or ultra-low-cycle fatigue (ULCF). ULCF is neither satisfactorily understood nor conveniently investigated compared to the monotonic ductile or low-cycle fatigue damage mechanisms. Having in mind the existing gaps in the knowledge about the ULCF, the ULCF European project, coordinated by FEUP, aimed at developing innovative computational methodologies for the simulation of steel material fracture under both monotonic and ultra-low-cycle fatigue, based on a significant experimental program including small and large-scale tests. This presentation makes an overview of the main results of the project, which includes: i) Database of small-scale testing data covering the X52, X60, X65, X70 and X80 piping steel grades. Smooth and special notched specimens were tested under both monotonic and cyclic (LCF & ULCF) loading. Dedicated monotonic tests were performed to assess the anisotropic behaviour of some materials (X70/X80). Combined multiaxial loading conditions were also investigated. ii) Database of full-scale testing results covering same materials also tested under small-scale conditions was generated. Monotonic and ULCF tests of pipe components were performed. ULCF tests included buckled and dented pipes, elbows and straight pipes. iii) New constitutive models for both monotonic and ULCF loading were proposed. Besides the Barcelona model, alternative approaches were investigated. Further constitutive refinements of nonlinear monotonic damage and enhanced anisotropic models, were also studied. iv) Developed constitutive models were calibrated and validated using experimentally derived testing data

Fundamentação téorica do modelo matemático para previsão de escorregamentos rasos Shallow Stability

Em áreas tropicais, escorregamentos são fenômenos comuns principalmente durante fortes chuvas que acontecem freqüentemente no verão. No Brasil, vários escorregamentos catastróficos vêm acontecendo em diversas regiões, principalmente nas três últimas décadas, devido à ocupação humana em escarpas íngremes. Com intuito de prever as porções da paisagem susceptíveis a ocorrência desses fenômenos, o modelo SHALSTAB (Shallow Stability) foi desenvolvido combinando um modelo hidrológico com um modelo de estabilidade de encosta, a partir de modelos digitais de terreno.Isto permite determinar a razão entre a quantidade de chuva e a transmissividade necessária para desestabilização da encosta, baseada na área de contribuição,declividade, ângulo de atrito, densidade e coesão do solo. Dentro deste contexto este trabalho tem como objetivo descrever esta metodologia demonstrando os fundamentos utilizados para o desenvolvimento do modelo de predição. _________________________________________________________________________________ ABSTRACTIn tropical areas, landslides are common phenomena especially durin gstrong rainfall that took place frequently in the summer. In Brazil, many catastrophic and slides occurred in many regions, mainly in the three last decades, due to humano ccupation in steep slope areas. In order to predict the landscape portions susceptibleto occurrence of these phenomena the SHALSTAB model was developed combininga hydrological model with the infinite slope stability model from digital elevation model. This allow to calculate the ratio of the steady state rainfall to soil transmissivityneeded to trigger slope failure based on drainage area, local slope, bulk density, frictionangle and soil cohesion. Thus, the present work has aim to describe SHALSTAB showing the fundaments used to develop the predict model

The scale dependence of mass assembly in galaxies

We compare the results of the mark correlation analysis of galaxies in a sample from the Sloan Digital Sky Survey and from two galaxy catalogs obtained by semi-analytical galaxy formation models implemented on the Millennium Simulation. We use the MOPED method to retrieve the star formation history of observed galaxies and use star formation parameters as weights to the mark correlations. We find an excellent match between models and observations when the mark correlations use stellar mass and luminosity as weights. The most remarkable result is related to the mark correlations associated to the evolution of mass assembly through star formation in galaxies, where we find that semi-analytical models are able to reproduce the main trends seen in the observational data. In addition, we find a good agreement between the redshift evolution of the mean total mass formed by star formation predicted by the models and that measured by MOPED. Our results show that close galaxy pairs today formed more stellar mass ~10 Gyr ago than the average, while more recently this trend is the opposite, with close pairs showing low levels of star formation activity. We also show a strong correlation in simulations between the shape and time evolution of the star formation marks and the number of major mergers experienced by galaxies, which drive the environmental dependence in galaxy formation by regulating the star formation process.Comment: 4 pages, 4 figures, final version accepted for publication in ApJ Letter

O ENSINO DE POESIA NOS ANOS FINAIS: O PAPEL DAS PLATAFORMAS DIGITAIS E A UTILIZAÇÃO DA KHAN ACADEMY COMO RECURSO PARA PROFESSORES E ALUNOS

Neste estudo, investigamos o ensino de poesia nos anos finais do Ensino Fundamental, explorando o papel das plataformas digitais e a utilização da Khan Academy como recurso para professores e alunos. Nosso objetivo foi compreender como a tecnologia digital pode ser utilizada no ensino e a relação entre professores e alunos na era digital. Utilizamos textos teóricos para examinar questões relacionadas ao ensino de literatura e poesia, bem como o uso de plataformas digitais. Como resultado, identificamos as vantagens e desvantagens dessas plataformas de ensino. Esta pesquisa contribui para uma melhor compreensão de como as plataformas digitais influenciam a interação entre professores e alunos na era digital

Combining spatial models for shallow landslides and debris-flows prediction

Mass movements in Brazil are common phenomena, especially during strong rainfall events that occur frequently in the summer season. These phenomena cause losses of lives and serious damage to roads, bridges, and properties. Moreover, the illegal occupation by slums on the slopes around the cities intensifies the effect of the mass movement. This study aimed to develop a methodology that combines models of shallow landslides and debris-flows in order to create a map with landslides initiation and debris-flows volume and runout distance. The study area comprised of two catchments in Rio de Janeiro city: Quitite and Papagaio that drained side by side the west flank of the Maciço da Tijuca, with an area of 5 km2. The method included the following steps: (a) location of the susceptible areas to landslides using SHALSTAB model; (b) determination of rheological parameters of debris-flow from the back-analysis technique; and (c) combination of SHALSTAB and FLO-2D models to delineate the areas more susceptible to mass movements. These scenarios were compared with the landslide and debris-flow event of February 1996. Many FLO-2D simulations were exhaustively made to estimate the rheological parameters from the back-analysis technique. Those rheological coefficients of single simulation were back-calculated by adjusting with area and depth of the debris-flow obtained from field data. The initial material volume in the FLO-2D simulations was estimated from SHALSTAB model. The combination of these two mathematical models, SHALSTAB and FLO-2D, was able to predict both landslides and debris-flow events. Such procedures can reduce the casualties and property damage, delineating hazard areas, to estimate hazard intensities for input into risk studies providing information for public policy and planning