1,035 research outputs found
Mathematical modeling of bovine brucellosis control by vaccination
As fêmeas bovinas, por sua importância na transmissão e na manutenção da brucelose, constituíram o alvo dos inquéritos do Programa Nacional de Controle e Erradicação da Brucelose e da Tuberculose Animal. Com base em informações obtidas em unidades federativas onde foram realizados inquéritos sorológicos e observadas prevalências de animais acima de 2%, elaborou-se um modelo para simular a dinâmica da brucelose em rebanhos bovinos formados exclusivamente por fêmeas, analisando o efeito de estratégias de vacinação. Para baixa cobertura vacinal, da ordem de 30%, o tempo para reduzir a prevalência a 2%, valor adotado como referência, pode ser longo, aproximando-se do dobro do tempo necessário para uma cobertura mais alta, de 90%. De acordo com o modelo, o tempo para reduzir a prevalência a 1% ou 2%, que permitam passar à fase de erradicação, pode chegar a uma década. Recomenda-se a intensificação do esforço para a vacinação de fêmeas, procurando atingir alta cobertura vacinal.Due to the important role played by female bovines in the transmission and maintenance of brucellosis, they were the target of the serological surveys of the Brazilian National Program for the Control and Eradication of Bovine Brucellosis and Tuberculosis. Based on the information obtained in Brazilian states, where the serological surveys were carried out and prevalences higher than 2% were observed, a model to simulate the dynamics of brucellosis in herds of female bovines was developed to analyze the effects of vaccination strategies. For low vaccination coverage (around 30%), the time to reduce the prevalence to 2%, adopted as a reference, may be long, approximately twice as long as the time observed for a higher coverage (90%). According to the model, the time to reduce the prevalence to levels of 1% or 2%, adequate to start the eradication phase, may reach a decade. It is recommended an intensification of the effort to vaccinate females, aiming at attaining high vaccination coverage.FAPESPCNPqMAPA Ministério da Agricultura, Pecuária e Abasteciment
34. Grip strength across Europe –North/ South and East/West divides
info:eu-repo/semantics/publishedVersio
Ventilation and energy efficiency of buildings
O presente artigo sustenta-se numa síntese de conhecimentos sobre ventilação e eficiência energética, num contexto social de maior procura de condições de conforto no interior dos mesmos. Nas últimas décadas tem aumentado a preocupação com o consumo excessivo de energias nos edifícios, o que conduziu ao desenvolvimento e implementação legislação de modo a controlar o problema. A par disso, têm-se desenvolvido diversos tipos de edifícios com elevada eficiência energética, tirando partido do meio em que se inserem e integrando princípios da arquitetura sustentável. Por outro lado, a qualidade de ar interior tem sido uma preocupação constante dos projetistas pois, atualmente, grande parte do dia é passado em espaços fechados e com concentrações de poluentes acima dos recomendados. Estas concentrações devem-se ao aumento da preocupação com a diminuição das infiltrações sem acautelar os valores de renovação de ar adequados. Atualmente, a legislação relativa ao desempenho energético dos edifícios veio evidenciar uma evolução ao nível das exigências regulamentares relativas aos vãos envidraçados, mostrando o forte impacto que estes elementos têm nas condições de conforto interior e por consequência nos consumos energéticos dos mesmos. Os vãos envidraçados são um elemento intermediário nas trocas de energia entre o interior e o exterior, representando também pontos de infiltração não controlada de ar. Torna-se vantajoso a reabilitação dos vãos envidraçados de modo a maximizar a qualidade do ar interior e as condições de conforto, sem aumentar os consumos energéticos.This article is based on a synthesis of knowledge regarding ventilation and energy efficiency, in a social context of greater
demand for comfort conditions inside them. In recent decades there has been a growing concern about the excessive
consumption of energy in buildings, which has led to the development and implementation of legislation to control the
problem. In addition, several types of buildings have been developed with high energy efficiency, taking advantage of the
environment in which they integrate and with integrating principles of sustainable architecture. On the other hand, the
quality of indoor air has been a constant concern of the project engineer because, today, a large part of the day is spent in
enclosed spaces and with concentrations of pollutants above those recommended. These concentrations are due to the
rising concern with the reduction of infiltrations without taking in consideration the adequate air renewal values. Currently,
the legislation on the energy performance of buildings has shown an evolution in the regulatory requirements for glazed
sills, showing the strong impact that these elements have on the interior comfort conditions and consequently on the energy
consumptions of themselves. Glazed sills are an intermediate element in energy exchanges between the interior and
exterior, also representing points of uncontrolled infiltration of air. It is advantageous to rehabilitate glazed sills in order to
maximize indoor air quality and comfort conditions without increasing energy consumption.info:eu-repo/semantics/publishedVersio
Fotossíntese, atividade cambial e diâmetro do coleto em Parkia gigantocarpa Ducke e Schizolobium amazonicum Huber ex Ducke (Leguminosae).
Prováveis causas da morte do capim-braquiarão (Brachiaria brizantha cv. Marandu) na Amazônia Oriental: relatório técnico.
bitstream/item/62003/1/Oriental-Doc36.pd
Infill masonry: simple analytical methods for seismic design
The latest earthquake codes in Europe require the safety assessment of no-structural elements (parapets, masonry wall’s veneer, infill walls, etc.), as their collapse entails risks for people or for the main structure stability. This work made possible th e development of a design method, supported by previous experimental researches by applying cyclic out-of-plane loads to damaged masonry infill in RC frames. Panels tested reproduce Portuguese traditional RC structure construction system and two reinforced solutions were created as innovative solutions. The experimental campaign was carried out in order to determine: masonry properties; out-of-plane panel behaviour with previous in-plane damage; building behaviour subjected to dynamic tests
performed in shaking table. Using finite element method to reproduce experimental tests and to broaden the range of samples it was possible to figure out equations according to parametric analysis which was able to reproduce in-plane and out-plane behaviour leading to an estimated load bearing capacity of each model and to determine frame strength and its stiffness. Those equations permit to design or verify the masonry infill panels in RC frames subjected to seismic loads
Behavior of masonry infill panels in RC frames subjected to in plane and out of plane loads
The building envelope in Europe is usually made of masonry walls, with enclosure and infill
functions. Masonry walls have a major economical importance and contribute significantly to
the building performance. Even if infill walls have no load-bearing function, they contribute
significantly to the seismic behavior of buildings. Therefore, their adequate structural
performance is needed, avoiding the occurrence of severe in-plane damage, with very large
economical losses, and the out-of-plane expulsion, which additionally represents a large risk
for human life.
Recent earthquake codes in Europe require the safety assessment of non-structural elements
(parapets, veneer masonry walls, infill walls, etc.), when their collapse entails risks for people
or for the main structure. The Eurocode standards, entering the mandatory stage now,
incorporate new requirements to be fulfilled by buildings or their parts. Such is the case of
masonry infilled RC frames whose panels, according to Eurocode 8, are explicitly required to
withstand the out-of-plane movement induced by earthquakes. Appropriate measures should
be taken to avoid brittle failure and premature disintegration of the infill walls, as well as the
partial or total out-of-plane collapse of slender masonry panels.
This paper presents the experimental work and results achieved by applying cyclic out-ofplane
loads to damaged masonry infilled RC frames. The masonry panels were previously
damaged by applying an in-plane cyclic load after which the cyclic out-of- plane loads were
applied. The frames and panels tested follow the traditional Portuguese RC structure
construction system to which different types of reinforcement have been introduced in the
panels
- …