Injectivity
Mostrando 1-12 de 13 artigos, teses e dissertações.
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1. Injectivity of the Dirichlet-to-Neumann Functional and the Schwarzian Derivative
Neste artigo mostramos a relação entre os núcleos de Schwartz dos operadores Dirichlet-to-Neumann associados à métrica g0 e h = F* (e²φ g0), no anel circular A R, e a Derivada Schwarziana da função argumento f, da restrição do difeomorfismo F à fronteira de A R.
Anais da Academia Brasileira de Ciências. Publicado em: 2010-12
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2. Injetividade de aplicações polinomiais via resolubilidade de campos vetoriais
Seja F : Rn → Rn uma aplicação polinomial tal que a aplicação derivada DF(x) seja invertível em cada ponto x ∈ Rn. Neste trabalho, usando técnicas de resolubilidade de certos campos de vetores, investigamos o papel do grau de F na sua injetividade. Em R2, mostramos que se o grau de uma das componentes de F é menor ou igual a 3, então F é
Publicado em: 2010
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3. Uma condição de injetividade e a estabilidade assintótica global no plano / A injectividade condition and the global asymptotic estability on the plane
In this work we are interested in the solution of the following problem: Let Y = ( f ,g) be a vector field of class C1 in R2. Suppose that (x, y) = (0,0) is a singular point of Y and assume that for any q ∈ R2, the eigenvalues of DY have negative real part, this is, det(DY) >0 and tr(DY) <0. Then, the solution (x, y) = (0,0) of Y is globally asymptotic
Publicado em: 2010
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4. Estudo sobre injeção de agua acima da pressão de propagação de fratura / Study of water injection with fracture propagation pressure
Produced water re-injection is a valuable method of water disposal and pressure and energy support. A common water re-injection problem is the injectivity loss, which affects negatively the process and restrains optimal water injection rates. The injectivity loss can be minimized by water injection with fracture propagation pressure (IFPP), which aims to res
Publicado em: 2008
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5. Estudo do fenômeno da auto-intersecção em um anel anisotrópico / Study of the self-intersection anomaly in an anisotropic ring
This work concerns a numerical study of a homogeneous circular plate with a centered hole that is under a state of plane strain. The plate is fixed at its inner surface and is under uniform radial compression at its outer surface. The plate is linear, elastic, and anisotropic. An analytical solution for this problem, which satisfies the governing equations o
Publicado em: 2008
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6. Global injectivity for applications between euclidean spaces / Injetividade global para aplicações entre espaços euclideanos
We present some results which give suficient conditions for a local diffeomorphism from the n-dimensional Euclidean space into itself be globally injective. Within this context, we consider some partial results addressed to solve the well known Fixed Point Conjecture and Jacobian Conjecture. From the dynamical point of view, there are connections between glo
Publicado em: 2007
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7. Modelagem de injeção de agua acima da pressão de fratura do reservatorio atraves de poço horizontal virtual / Modeling water injection above reservoir formation parting pressure through a virtual horizontal well
Water injection has been the most used method to improve oil recovery. The main problem of this method, related directly with operational efficiency, is the injectivity loss which is the loss of capacity to maintain water injection rates due to formation damage. Different models have been proposed to minimize the injectivity loss effects due to its high econ
Publicado em: 2007
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8. MODELO ESTOCÁSTICO PARA A EXCLUSÃO PELO TAMANHO DURANTE O TRANSPORTE DE SUSPENSÕES PARTICULADAS EM MEIOS POROSOS / STOCHASTIC MODEL FOR SIZE EXCLUSION MECHANISM DURING SUSPENDED PARTICLE SUSPENSION TRANSPORT IN POROUS MEDIUM
Deep bed filtration of water with particles occurs in several industrial and environmental processes like water filtration and soil contamination. In petroleum industry, deep bed filtration occurs near to injection wells during water injection, causing injectivity reduction. It also takes place during well drilling, sand production control, produced water di
Publicado em: 2005
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9. VERIFICAÇÃO DE MODELOS ANALÍTICOS PARA A PERDA DE INJETIVIDADE DE ROCHAS / ANALYTICAL STUDY OF THE INJECTIVITY LOSS OF ROCKS
This work deals with the impairment of rocks subjected to the injection of water with solid particles in suspension. The effect of the permeability reduction and consequent loss in rock injectivity is analyzed by the interpretation of core flow tests, previously reported, and simulated by using a computational program developed for this research. The program
Publicado em: 2002
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10. NUMERICAL STUDY OF LOSS OF INJECTIVITY IN ROCK / ESTUDO NUMÉRICO DE DECLÍNIO DE INJETIVIDADE EM ROCHA
Esta dissertação apresenta um estudo numérico, utilizando o método dos elementos finitos, para simular o entupimento de rochas provocado pela injeção de água contendo partículas sólidas. Dentre os diferentes parâmetros que afetam o declínio de injetividade, quatro foram analisados, considerando-se a situação de fluxo unidimensional: fator de dan
Publicado em: 2002
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11. Alguns aspectos da geometria riemanniana das variedades de Hilbert
The aim of this work is to formalize the local theory of infinite dimensional Riemannian manifold and to study the geometry/ topology when the sectional curvature is bounded by two positive constant. We compare this situation with the finite dimensional case and emphasize the difference. The local theory was already developed since 1960, so we describe, brie
Publicado em: 2002
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12. Analise de testes em poços injetores de agua
Analytical solutions for different water injection models are compared and some interesting analogies and conclusions are established, for instance, concerning the measured skin factor in an injectivity testo A new semi-analytical model for water injection transient studies is proposed. Also, a new and simple method to estimate oil and water relative permeab
Publicado em: 1991