Encontrados 13 documentos, a visualizar página 1 de 2
Manejo do nitrogênio nas culturas do milho e do feijoeiro de inverno em palhada...
OLIVEIRA, P. de; FAVARIN, J. L.; KLUTHCOUSKI, J.; SANTOS, D. de C.Nessa publicação, são apresentados os resultados de pesquisa sobre o manejo do N na cultura de milho consorciada com braquiária (Brachiaria brizantha) e guandu-anão (Cajanus cajan), proporcionado pela dessecação parcial, e de feijoeiro de inverno em sucessão. ; 2010
Antecipação de nitrogênio em cultivares de feijão sobre palhadas de cobertura d...
OLIVEIRA, P. de; KLUTHCOUSKI, J.; FAVARIN, J. L.; COBUCCI, T.Neste documento, são apresentados resultados de pesquisa do cultivo de cinco cultivares de feijão, no inverno de 2009, sobre palhada de soja e de milho + braquiária. Destaca-se que a área utilizada é mantida sob esquema trienal de rotação de pastagem de braquiária e culturas graníferas. ; 2010
Flux Tracking in delivery polymeric systems
Ferreira, J. A.; Oliveira, P. de; Silva, P. M. da; Simon, L.The dynamics of diffusive and stress-induced transport in polymeric delivery systems was investigated. Partial and ordinary differential equations were first written to describe drug release behaviors in Maxwell and Maxwell-Voigt materials. The time constants governing the flux and concentration responses of a permeating species were determined from a Laplace transform solution of the original model. A ”trackin...
Drug delivery: from a contact lens to the anterior chamber
Ferreira, J. A.; Oliveira, P. de; Silva, P. M. da; Murta, J. N.Mathematical models to describe drug concentration profiles of topically administered drug in the anterior chamber aqueous humor have been proposed by several authors. The aim of this paper is to present a mathematical model to predict the drug concentration in the anterior chamber when a therapeutical contact lens with the drug is entrapped in nanoparticles is used.
Uso de braquiárias para o manejo de doenças causadas por patógenos habitantes d...
LOBO JUNIOR, M.; BRANDÃO, R. S.; CORRÊA, C. A.; GÖRGEN, C. A.; CIVARDI, E. A.; OLIVEIRA, P. de.A severidade de doenças causadas por patógenos habitantes do solo é geralmente proporcional à densidade de inóculo de seus agentes causais, como no caso do mofo branco (Sclerotinia sclerotiorum) e das podridões radiculares do feijoeiro comum, causadas por Fusarium solani e Rhizoctonia solani. As recomendações técnicas para se controlar essas doenças e minimizar seus danos envolvem a redução da população de estr...
Sustained drug released from contact lens
Ferreira, J. A.; Oliveira, P. de; Silva, P. M. da; Carreira, A.; Gil, H.; Murta, J. N.This paper focuses on ophthalmic drug release from a loaded copolymer: the drug is dispersed in the polymeric matrix and entrapped in particles. The copolymer is based in 2-hydroxyethyl methacrylate co-methacrylic acid and silicone is used to prepare the loaded particles. A mathematical model to simulate the drug release is proposed and a qualitative analysis is performed. Experimental results are compared with...
Using splitting methods in continuous digester modeling
Araújo, A.; Ferreira, J. A.; Fernandes, N.; Oliveira, P. deThe pulp and paper industry plays an important role in European economies. The chemical reactions that transform wood chips in pulp occur mainly in a complex moving bed reactor, the digester. Nowadays the use of mathematical models to simulate the transient behaviour of the digester in terms of temperature and compound concentrations represents a real need for industry because it allows simulation of experiment...
Memory in the Black-Scholes model
Ferreira, J. A.; Oliveira, P. deThe evolution in time of European options is usually studied using the Black-Scholes formula. This formula is obtained from the equivalence between the Black-Scholes equation and a heat equation. The solution of the last equation presents infinite speed of propagation which induces the same property for European options. In this paper we study integro-differential equations which can be used to describe the evo...
Memory effects and random walks in reaction-transport systems
Ferreira, J. A.; Oliveira, P. deIn this article, we study continuous and discrete models to describe reaction transport systems with memory and long range interaction. In these models the transport process is described by a non-Brownian random walk model and the memory is induced by a waiting time distribution of the gamma type. Numerical results illustrating the behavior of the solution of discrete models are also included. ; http://www.i...
A phenomenological model for desorption in polymers
Comissiong, D. M. G.; Ferreira, J. A.; Oliveira, P. deA phenomenological formulation is adopted to investigate desorption in polymers. The speed of the front is studied and the well-posedeness of the general model is analyzed. Numerical simulations illustrating the dynamics of the desorption process described by the proposed model are included ; Center for Mathematics of University of Coimbra
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