280 research outputs found

    Finite Element Modeling and Experiments of Systems with Viscoelastic Materials for Vibration Attenuation

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    This chapter addresses the finite element modeling methodologies intended for performance evaluation, analysis, and design of viscoelastic systems. The mathematical models widely used to represent the frequency and temperature dependent behavior of viscoelastic materials are also considered, namely the complex modulus approach, the fractional derivative model, the Golla-Hughes-McTavish (GHM) model, and the anelastic displacement fields (ADFs) model. The straightforward strategies to integrate the viscoelastic effects into finite element matrices of structural systems such as three-layer sandwich plates, intended for the modeling of medium and large-scale engineering structures, are presented. In the same context, emphasis is placed on the condensation methods for the reduction of the order of the finite element matrices to perform frequency-response functions, complex eigenvalue problem, and time domain analyses. Based on the fact that for viscoelastic materials subjected to dynamic loadings superimposed on static preloads, the classical modeling assuming isothermal conditions can lead to poor designs, since the energy dissipated within the volume of the material leads to temperature rises, an experimental investigation of the self-heating phenomenon is also addressed

    Wild dogs at stake: deforestation threatens the only Amazon endemic canid, the short-eared dog (Atelocynus microtis)

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    The persistent high deforestation rate and fragmentation of the Amazon forests are the main threats to their biodiversity. To anticipate and mitigate these threats, it is important to understand and predict how species respond to the rapidly changing landscape. The short-eared dog Atelocynus microtis is the only Amazon-endemic canid and one of the most understudied wild dogs worldwide. We investigated short-eared dog habitat associations on two spatial scales. First, we used the largest record database ever compiled for short-eared dogs in combination with species distribution models to map species habitat suitability, estimate its distribution range and predict shifts in species distribution in response to predicted deforestation across the entire Amazon (regional scale). Second, we used systematic camera trap surveys and occupancy models to investigate how forest cover and forest fragmentation affect the space use of this species in the Southern Brazilian Amazon (local scale). Species distribution models suggested that the short-eared dog potentially occurs over an extensive and continuous area, through most of the Amazon region south of the Amazon River. However, approximately 30% of the short-eared dog's current distribution is expected to be lost or suffer sharp declines in habitat suitability by 2027 (within three generations) due to forest loss. This proportion might reach 40% of the species distribution in unprotected areas and exceed 60% in some interfluves (i.e. portions of land separated by large rivers) of the Amazon basin. Our local-scale analysis indicated that the presence of forest positively affected short-eared dog space use, while the density of forest edges had a negative effect. Beyond shedding light on the ecology of the short-eared dog and refining its distribution range, our results stress that forest loss poses a serious threat to the conservation of the species in a short time frame. Hence, we propose a re-assessment of the short-eared dog's current IUCN Red List status (Near Threatened) based on findings presented here. Our study exemplifies how data can be integrated across sources and modelling procedures to improve our knowledge of relatively understudied species

    Bologna process, higher education and a few considerations about the New University

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    O presente artigo analisa o que se convencionou chamar de Processo de Bolonha, isto é, a produção de uma “política pública de um meta-Estado para um meta-campo universitário”, constituindo-se em uma política educacional supranacional, comum aos estados-membros da União Européia, com vista à construção de um “espaço europeu de educação superior”. O processo político e de reformas institucionais, realizado por cada governo nacional, conduzirá ao estabelecimento efetivo do novo sistema europeu de educação superior até 2010, incluindo atualmente 45 países – todos os da UE e outros 18 países europeus não pertencentes a ela. Nesse sentido, por se tratar de um vastíssimo número de “subsistemas nacionais” e de instituições educativas, atribui-se um grande protagonismo às questões relativas à “garantia de qualidade”. Analisam-se, igualmente, as recentes transformações na educação superior no Brasil, em que o projeto da chamada “Universidade Nova” e o Programa de Apoio a Planos de Reestruturação e Expansão das Universidades Federais (REUNI) constituem-se nas manifestações mais claras do reordenamento desse nível de ensino (seguindo os parâmetros de Bolonha), que já experimentara grandes transformações nos governos de Fernando Henrique Cardoso (1995-2002) e teve prosseguimento nos governos de Luiz Inácio Lula da Silva (2003-2006; 2007), embora com distintos matizes.This article analyzes what is conventionally known as the Bologna Process, or the making of a “public policy of a meta-State for a University meta-field” that corresponds to a supranational educational policy for all the European Union membership States, with the goal of building a “European higher education space.” The political process and the institutional reforms of each national government intends to establish the new European higher education system until 2010, with 45 countries – the number reflects current developments, including the EU membership States and 18 non-EU countries. Given the high quantity and the myriads of “national subsystems” and educational institutions involved, “quality assurance” becomes a major task in this process. We analyze, in the same way, the recent higher education changes in Brazil, where the so-called “New University” project and the Program of Support for the Restructuring and Expansion of Brazilian Federal Universities (REUNI, in Portuguese) are the clearest expressions of the reshaping of the higher education system (in accordance with the Bologna standards) after the dramatic changes made by Fernando Henrique Cardoso´s government (1995-2002) and continued by Luiz Inácio Lula da Silva´s government (2003-2006; 2007), despite some differences between both administrations

    Impact of common cardio-metabolic risk factors on fatal and non-fatal cardiovascular disease in Latin America and the Caribbean: An individual-level pooled analysis of 31 cohort studies

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    Background: Estimates of the burden of cardio-metabolic risk factors in Latin America and the Caribbean (LAC) rely on relative risks (RRs) from non-LAC countries. Whether these RRs apply to LAC remains unknown. Methods: We pooled LAC cohorts. We estimated RRs per unit of exposure to body mass index (BMI), systolic blood pressure (SBP), fasting plasma glucose (FPG), total cholesterol (TC) and non-HDL cholesterol on fatal (31 cohorts, n=168,287) and non-fatal (13 cohorts, n=27,554) cardiovascular diseases, adjusting for regression dilution bias. We used these RRs and national data on mean risk factor levels to estimate the number of cardiovascular deaths attributable to non-optimal levels of each risk factor. Results: Our RRs for SBP, FPG and TC were like those observed in cohorts conducted in high-income countries; however, for BMI, our RRs were consistently smaller in people below 75 years of age. Across risk factors, we observed smaller RRs among older ages. Non-optimal SBP was responsible for the largest number of attributable cardiovascular deaths ranging from 38 per 100,000 women and 54 men in Peru, to 261 (Dominica, women) and 282 (Guyana, men). For non-HDL cholesterol, the lowest attributable rate was for women in Peru (21) and men in Guatemala (25), and the largest in men (158) and women (142) from Guyana. Interpretation: RRs for BMI from studies conducted in high-income countries may overestimate disease burden metrics in LAC; conversely, RRs for SBP, FPG and TC from LAC cohorts are similar to those estimated from cohorts in high-income countries. Funding: Wellcome Trust (214185/Z/18/Z)Fil: Carrillo Larco, Rodrigo M.. Imperial College London; Reino UnidoFil: Stern, Dalia. Instituto Nacional de Salud Publica (insp);Fil: Hambleton, Ian R.. The University Of The West Indies; BarbadosFil: Hennis, Anselm. Pan American Health Organization; Estados UnidosFil: Cesare, Mariachiara Di. Middlesex University; Reino UnidoFil: Lotufo, Paulo. Universidade de Sao Paulo; BrasilFil: Ferreccio, Catterina. Pontificia Universidad Católica de Chile; ChileFil: Irazola, Vilma. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Centro de Investigaciones en Epidemiología y Salud Pública. Instituto de Efectividad Clínica y Sanitaria. Centro de Investigaciones en Epidemiología y Salud Pública; Argentina. Instituto de Efectividad Clínica y Sanitaria; ArgentinaFil: Perel, Pablo. London School of Hygiene and Tropical Medicine; Reino UnidoFil: Gregg, Edward W. Imperial College London; Reino UnidoFil: Miranda, J. Jaime. Universidad Peruana Cayetano Heredia; PerúFil: Ezzati, Majid. Imperial College London; Reino UnidoFil: Danaei, Goodarz. Harvard Medical School; Estados UnidosFil: Aguilar Salinas, Carlos A.. Instituto Nacional de Ciencias Médicas y Nutrición; MéxicoFil: Alvarez Váz, Ramón. Universidad de la República; UruguayFil: Amadio, Marselle B.. Centro Universitario Senac Santo Amaro; BrasilFil: Baccino, Cecilia. Universidad de la República; UruguayFil: Bambs, Claudia. Pontificia Universidad Católica de Chile; ChileFil: Bastos, João Luiz. Universidade Federal de Santa Catarina; BrasilFil: Beckles, Gloria. Centers for Disease Control and Prevention; Estados UnidosFil: Bernabe Ortiz, Antonio. Universidad Peruana Cayetano Heredia; PerúFil: Bernardo, Carla DO. University of Adelaide; AustraliaFil: Bloch, Katia V.. Universidade Federal do Rio de Janeiro; BrasilFil: Blümel, Juan E.. Universidad de Chile; ChileFil: Boggia, Jose G.. Universidad de la República; UruguayFil: Borges, Pollyanna K.. Universidade Estadual do Ponta Grossa; BrasilFil: Bravo, Miguel. MELISA Institute; ChileFil: Brenes Camacho, Gilbert. Universidad de Costa Rica; Costa RicaFil: Carbajal, Horacio A.. Universidad Nacional de La Plata; ArgentinaFil: Castillo Rascón, María Susana. Universidad Nacional de Misiones; Argentin
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