Influência da modelação de núcleos de betão armado no cálculo automático de estruturas de edifícios

O presente trabalho aborda a questão do comportamento e influência estrutural da modelação de um núcleo de secção aberta de parede fina no modelo tridimensional de elementos finitos de um edifício de betão armado, composto por 5 pisos sujeito à acção sísmica regulamentar. Para o efeito, foram considerados os Eurocódigos estruturais, nomeadamente o Eurocódigo 0, Eurocódigo 1 e Eurocódigo 8. A fim de avaliar a importância do tipo de modelação destes elementos estruturais, elemento fundamental para a caracterização da resposta dinâmica, foi desenvolvido um estudo paramétrico, fazendo-se a análise de quatro formas distintas de modelação do mesmo núcleo. Para os mesmos casos de carregamento, é feita uma análise comparativa entre os resultados obtidos a nível de períodos, percentagem de armadura nos pilares e no próprio núcleo bem como os deslocamentos para os modelos em estudo, com recurso a um programa de cálculo automático. O edifício considerado neste trabalho foi modelado com base no programa comercial de cálculo automático SAP 2000 versão 14.4. Posteriormente apresentam-se e discutem-se os resultados obtidos nos vários modelos em causa e para as várias situações propostas ao longo do trabalho.This work presents the question of structural influence on the modeling a core thin-walled open section of concrete in a building consisting of 5 floors, subject to seismic regulations. To this effect, we considered the structural Eurocodes, in particular Eurocode 0, Eurocode 1 and Eurocode 8. In order to assess the importance of the type of modeling these structural elements, a key factorto characterize the dynamic response, a parametric study was developed, making the analysis of four distinct forms of the same core model. For the same loading cases, a comparative analysis are made between the results obtained in levels of periods, reinforcement percentage in the columns and core and displacements for the model under study, using an automatic calculation program. The building considered in this work was modeled on the basis commercial program for automatic calculation, SAP2000 V14.4 Subsequently, we present and discuss the results obtained for the various models involved and proposals for the various situations along the work

The Analysis and Modeling of the Deployment of NASA's X-38 Parafoil

NASA is currently working on developing the X-38 Crew Return Vehicle for the Internati6nal Space Station (ISS). The aerodynamics of the X-38 and its enormous 7500 square ft parafoil are extremeJy complicated and must be understood and modeled accurately before the vehicle is actually used for human space flight. A large amount of analysis has been performed on the steady state regions of the flight profile when the parafoil is already open. However, the deployment region of the flight profile has not been analyzed in much depth and is a particularly complicated dynamic flight period. During deployment, the X-38 system has its parafoil open up to its full area in five stages over a period of 20-30 seconds. The vehicle transitions from angles of attack around 90 deg to 0 deg in about two seconds and is extremely dynamic. This paper will detail the analysis work done to generate accurate flight profile characteristics of the deployment from flight data from vehicle test drops. Additionally, a computer simulation tool for steady state flight was modified to analyze and model the parafoil deployment. Eventually, a computer model was produced that generated accurate representations of the parafoil deployment dynamics for the vehicle test drops to date

Why do some soccer bettors lose more money than others?

Why do some soccer bettors lose more money than others? In an efficient prediction market, each gambler should break-even before costs (but losing a constant amount after costs, reflecting the bookmaker’s margin). Previous empirical studies across numerous sports betting markets show that bets on longshots tend to lose more than bets on favourites (favourite-longshot bias). We use 163,992 soccer odds from ten European leagues to test plausible hypotheses around why some soccer bettors lose more money than others. Are soccer bettors with above average losses simply biased, or are their losses driven by betting on events that are inherently unpredictable? We confirm the existence of favourite-longshot bias in soccer in this sample, but find another surprising feature of betting on longshots. As measured by the Brier score, bookmakers’ odds were better predictors of longshots than favourites, suggesting another potential channel whereby bettors’ preference for betting on longshots may cost them dearly

La ludoteca como posibilidad para desvelar la rutina del niño con cáncer en tratamiento ambulatorio

A proposta deste estudo é desvelar o sentido de Ser-criança com câncer em tratamento ambulatorial, utilizando a brinquedo-teca como possibilidade de favorecer a expressão, pela criança, de seu mundo cotidiano. Participaram sete crianças entre três e nove anos, com diagnóstico de algum tipo de câncer infantil. A fim de desvelar o sentido das vivências das crianças com câncer, foi realizada uma análise à luz da fenomenologia existencial de Martin Heidegger. A criança-com-câncer configurou-se como um ir e vir permeado ora pela autenticidade, quando a criança assumia sua doença e seu ser-para-a-morte, ora pela inautenticidade, quando se deixava levar pelo modo de ser da decadência dos familiares e da equipe de saúde. O brincar pôde favorecer um rico acesso às vivências da criança gravemente doente.The purpose of this study is to learn the meaning of being-a-child with cancer submitted to ambulatory treatment and using the toy library as a possibility to enable their expression about their world. Participants were seven children of ages 3 to 9 years, who had been diagnosed with some kind of childhood cancer. With the objective of learning about the meaning of these experiences to children with cancer, an analysis of these data was performed based on Martin Heidegger's existential phenomenology. The child-with-cancer showed a movement that was permeated sometimes by authenticity, when the child assumed the disease and their being-toward-death and also by the lack of authenticity, when they were influenced by the decadence attitude of their relatives and health team members. Playing provided a rich contact with the existence of these severely ill children.La propuesta de este estudio es develar el sentido del Ser-niño con cáncer en tratamiento ambulatorio, utilizando la ludoteca como posibilidad de favorecer la expresión, por parte del niño, de su mundo cotidiano. Participaron siete niños de entre tres y nueve años con diagnóstico de algún tipo de cáncer infantil. A los efectos de develar el sentido de las experiencias de los niños con cáncer, se realizó un análisis a la luz de la fenomenología existencial de Martin Heidegger. El niño-con-cáncer exhibió un movimiento de ida y vuelta, permeado algunas veces por la autenticidad, cuando el niño asumía su enfermedad y su ser-para-la-muerte, y otras veces por la inauten-ticidad, cuando se dejaba llevar por el modo de ser de la decadencia de los familiares y del equipo de salud. El jugar puede favorecer un rico acceso a las experiencias del niño gravemente enfermo.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

Microestructure and mechanical properties of biomorphic SiC obtained from eucalyptus

El desarrollo de materiales cerámicos con una estructura de tipo celular, similar a la del hueso o la madera, ha sido una cuestión que ha suscitado un gran interés en los últimos años. Su atractivo se debe al hecho de poseer una estructura porosa altamente interconectada de baja densidad, perfeccionada por la evolución. En el caso del SiC biomórfico (bio-SiC) el proceso de fabricación es sencillo: se piroliza una pieza de madera y a continuación se inyecta con silicio líquido, el material así obtenido es un compuesto Si/SiC en el que el SiC mimetiza la estructura de la madera original. En este trabajo se estudian las propiedades mecánicas del SiC biomórfico fabricado a partir de eucalipto (madera dura con una distribución bimodal de poros). Se ha estudiado el comportamiento mecánico del mismo (resistencia a compresión, resistencia a flexión, tenacidad de fractura y módulo de elasticidad) entre 25 y 1350 o C. Asimismo, se discute la relación entre el comportamiento mecánico del material y su microestructura.The development of cellular ceramics with a biological structure, like bones and wood, has been a matter of interest in recent years. A low density highly interconnected structure, perfected by evolution, rises as the principal advantage of these materials. In the case of biomimetic SiC (biomorphic SiC, or bioSiC), the fabrication process technique is quite simple: a piece of wood is pyrolysed and is infiltrated with molten silicon after, the final product is a composite Si/SiC, which replicates the wood anisotropic microstructure This work focus on the mechanical properties of bioSiC fabricated using eucalyptus wood as precursor (hard wood with a bimodal channel distribution). It has been studied the mechanical behavior of this bioSiC (compression strength, flexure strength, fracture toughness and elastic modulus) between 25 and 1350 o C. It is also discussed the relationship between mechanical behavior of the material and its microstructure

Aplicaciones del SiC biomórfico como reforzante estructural en hormigones refractarios

Una posible aplicación del SiC biomórfico (bioSiC) son los reforzante estructural en hormigones refractarios. En este caso se han fabricado piezas de bioSiC con forma de cilindros alargados, 3-4 mm de diámetro y 30-35 mm de longitud, mediante infiltración reactiva de Si líquido en piezas de carbón obtenidas por pirolización de madera de haya de calidad comercial. Hemos estudiado las características microestructurales y las propiedades mecánicas de los reforzantes, como paso previo al estudio de la aplicación mencionada, de la que se ofrece un avance en este trabajo. Para caracterizar la calidad del material y del proceso de fabricación, la microestructura de las piezas se ha estudiado mediante microscopía electrónica de barrido. Los reforzantes de bioSiC fueron ensayados a compresión uniaxial y flexión en cuatro puntos a temperatura ambiente y a alta temperatura (1250-1400ºC) para la determinación de sus propiedades mecánicas, y se realizaron estudios fractográficos en el segundo tipo de ensayos. Subsecuentemente, se prepararon ladrillos refractarios con un 3% en peso de reforzantes de bioSiC, que fueron curados a diferentes temperaturas (máx. 1600ºC). Estos ladrillos se han ensayado en compresión y flexión en tres puntos, a temperatura ambiente, comparándose los resultados con los obtenidos en ladrillos sin reforzantes y reforzados con agujas metálicas de calidad comercial (acero refractario 306 ó 310), con la misma formulación y condiciones de curado.This work is devoted to the study of the time and temperature dependence of the static grain growth in YTZP 4 mol %, with an average grain size within the submicrometric range ( > 0.1 µm). Also, the mechanical response in the temperature interval between 1200 ºC and 1500 ºC is analysed. The grain growth is controlled by the yttria segregation at the grain boundaries, which plays a key role in the cationic diffusion processes. Microstructural characterization of both as-received and deformed samples allows to conclude that plastic deformation is due to grain boundary sliding (GBS), with stress exponents increasing with the flow stress, but in all cases they are lower than n = 2

Gardner-Webb Review, Volume 2, 2000

Annual publication associated with the Life of the Scholar Multidisciplinary Conference. This publication presents selected essays written by undergraduate students at Gardner-Webb University

Gardner-Webb Review, Volume 3, 2001

Annual publication associated with the Life of the Scholar Multidisciplinary Conference. This publication presents selected essays written by undergraduate students at Gardner-Webb University