3,881 research outputs found
A utilização de óleo de palma como componente do biodiesel na Amazônia.
bitstream/item/27700/1/com.tec.103.pd
A kinetic model for chemical reactions without barriers : transport coefficients and eigenmodes
The kinetic model of the Boltzmann equation proposed in the work of Kremer and Soares 2009 for a binary mixture undergoing chemical reactions of symmetric type which occur without activation energy is revisited here, with the aim of investigating in detail the transport properties of the reactive mixture and the influence of the reaction process on the transport coefficients. Accordingly, the non-equilibrium solution of the Boltzmann equation is determined through an expansion in Sonine polynomials up to the first order, using
the Chapman-Enskog method, in a chemical regime for which the reaction process is close to its final equilibrium state. The non-equilibrium deviations are explicitly calculated for what concerns the thermal-diffusion ratio and coefficients of shear viscosity, diffusion and thermal conductivity. The theoretical and formal analysis developed in the present paper is complemented with some numerical simulations performed for different concentrations of reactants and products of the reaction as well as for both exothermic and endothermic chemical processes. The results reveal that chemical reactions without energy barrier can induce an appreciable influence on the transport properties of the mixture. Oppositely to the case of reactions with activation energy, the coefficients of shear viscosity and thermal conductivity become larger than those of an inert mixture when the reactions are exothermic. An application of the non-barrier model and its detailed transport picture is included in this paper, in order to investigate the dynamics of the local perturbations on the constituent number densities, and velocity and temperature of the whole mixture, induced by spontaneous internal fluctuations. It is shown that for the longitudinal disturbances there exist two hydrodynamic sound modes, one purely diffusive hydrodynamic mode and one kinetic mode.This paper is partially supported by the Brazilian Research Council (CNPq), by Minho University Mathematics Centre (CMAT-FCT) and by Project FCT-PTDC/MAT/68615/2006
Efeito de infestação de Tibraca limbativentris (Heteroptera: pentatomidae) na produção de arroz irrigado.
Experimentos de campo foram conduzidos durante os cultivos de 2006 e 2007 para determinar o impacto de infestação de T. limbativentris (percevejo-do-colmo) na produção de grãos de arroz irrigado.Resumo ID: 111-1
Efeito do regulador vegetal cloreto de clormequat nos componentes da produção e na produtividade do feijoeiro.
O objetivo deste trabalho foi avaliar os efeitos de doses do regulador de crescimento cloreto de clormequat, marca comercial Tuval®, aplicado de forma parcelada, em algumas características agronômicas e na produtividade do feijoeiro
Doses e formas de aplicação de uréia comum e aditivada no feijoeiro irrigado cultivado em plantio direto.
O objetivo deste trabalho foi avaliar a resposta do feijoeiro irrigado por aspersão, sistema pivô central, cultivado em condições de plantio direto no sistema integração lavourapecuária, à adubação com duas fontes de N, uréia normal e uréia aditivada, duas formas de aplicação, em superfície e incorporada, e quatro doses de N em cobertura, em Latossolo Vermelho distroférrico
Estudo da desidratação osmótica de abóbora utilizando metodologia de superfície de resposta.
Suplemento 1. Edição dos Resumos do 43 Congresso Brasileiro de Olericultura, Recife, jul. 2003
Padronização de procedimentos para upload de dados no Sistema de Gerenciamento de Rebanhos - SGR.
Resposta do arroz irrigado à infestação de Tibraca limbativentris (Heteroptera: pentatomidae).
O objetivo deste trabalho foi determinar o relacionamento entre a população de T. limbativentris e a redução na produção de arroz irrigado. A quantificação desta relação é essencial para a determinação do nível de dano econômico para esta praga
Performance of tiles composed of blast furnace slag and vegetable fiber in prototype barns
Busca-se, em todo o mundo, a substituição do cimento amianto por alternativas seguras para o ambiente e para a saúde do trabalhador, além de econômicas, razão por que o uso de fibras vegetais como aglomerado em países tropicais onde estes resíduos são abundantes, tem-se mostrado bastante viável. No presente experimento foram comparadas telhas de cimento amianto pintadas com tinta reflexiva, telhas cerâmicas e telhas compostas de uma matriz à base de cimento Portland CPII 32Z (ABNT NBR-5735), escória de alto-forno (EAF) e sílica ativa, reforçadas com fibras de polpa celulósica de sisal (Agave sisalana). Utilizaram-se protótipos de galpões avícolas nos quais o calor produzido pelas aves foi simulado por lâmpadas incandescentes. Para caracterização do ambiente térmico lançou-se mão dos índices de conforto: ITU (índice de temperatura e umidade), ITGU (índice de temperatura de globo e umidade), CTR (carga térmica radiante) e entalpia (H) em que os resultados demonstraram que as telhas compostas apresentaram comportamento térmico semelhante ao das telhas cerâmicas, podendo ser utilizadas em substituição às telhas de cimento amianto.The substitution of cement asbestos by safer and equally economical alternatives has being searched for throughout the world. The usage of vegetal staple fiber as agglomerate in tropical countries where these residues are abundant has shown it self to be viable. In this study, roofing tiles fabricated with cement base Portland CPII 32Z (ABNT NBR-5735), blast furnace slag (EAF), active silica reinforced with cellulose pulp staple fibers of sisal (Agave sisalana) were compared with cement asbestos roofing tiles with white paint and ceramic roofing tiles. Prototypes of poultry facilities were used and lamps simulated the heat produced by the birds. Indices ITU, ITGU, CTR and entalpy (H) were employed for the characterization of the thermal atmospheric comfort and the results showed that the alternative roofing tiles were similar to the ceramic tiles and could be used as a substitute for asbestos roofing tiles
Anatomical Basis, Histological Findings and Hemodinamics in the Modern Perfusion Model for Human Corpses
sSeveral modern human cadaveric fixation methods are subject to permanent evaluation. Formaldehyde is the
oldest and still the most widely used method of embalming. However, the International Agency for Research on Cancer has proven its high carcinogenic potential and its use was banned, with the recommendation of research for better alternatives in the conservation of corpses. The embalming method of excellence, which preserves all features, while keeping the disinfectant properties against cadaveric decomposition was proposed by João Goyri O’Neill. Their method was considered “the most modern and efficient technique in cadaveric preservation”. The aim of this present study was to analyze the quality of this original perfusion technique, at the organic level, based on central and peripheral hemodynamics. The cadaveric material was embalmed through a pulsed arterial perfusion system, connected to an automatic intermittent pump, that permits stability
of the microvascular network, as well as the computerized measurement of the main perfusion parameters, such as flow and pressure. This procedure ensures good preservation of color, elasticity, texture, flexibility and fresh appearance, for several years. The morphological characteristics of the organs exhibited astonishing similarity to the living organic tissues, even several years after embalming and high freezing. Microscopic analysis demonstrated preservation of the structure of vessels, such as the aorta. Further studies on the integrity of the endocardial layer of the heart will enable to adapt the intermittent perfusion pump system to best simulate cardiac rhythm and arterial pulse, during cadaveric surgical training.info:eu-repo/semantics/publishedVersio
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