Abstract In reducing the grid orientation effect for the numerical solution of partial differential equations, interpolation functions play an important role when the advective transport of the governing equations is considered. This is due to the fact that, in general, the unknowns are evaluated in the vertices of the elements and such properties must be extrapolated to inner parts of the elements. First-order schemes, such as upwind, are the easiest methods to use for performing the extrapolation of the properties. However, such methods introduce a large amount of numerical diffusion in the solution. A few higher-order interpolation schemes, on the other hand, are capable of providing solutions free of numerical diffusion, increasing the accuracy of the method and reducing the computational efforts required. In this work, we investigate the TVD interpolation scheme for three-dimensional unstructured grids in conjunction with Element-based Finite Volume Method (EbFVM) using four types of elements: hexahedron, tetrahedron, prism and pyramid.

Abstract In the last decade, unstructured grids have been a very important step in the development of petroleum reservoir simulators. In fact, the so-called third generation simulators are based on Perpendicular Bisection (PEBI) unstructured grids. Nevertheless, the use of PEBI grids is not very general when full anisotropic reservoirs are modeled. Another possibility is the use of the Element based Finite Volume Method (EbFVM). This approach has been tested for several reservoir types and in principle has no limitation in application. In this paper, we implement this approach in an in-house simulator called UTCOMP using four element types: hexahedron, tetrahedron, prism, and pyramid. UTCOMP is a compositional, multiphase/multi-component simulator based on an Implicit Pressure Explicit Composition (IMPEC) approach designed to handle several hydrocarbon recovery processes. All properties, except permeability and porosity, are evaluated in each grid vertex. In this work, four case studies were selected to evaluate the implementation, two of them involving irregular geometries. Results are shown in terms of oil and gas rates and saturated gas field.

INTRODUÇÃO Apesar dos inúmeros benefícios para a saúde humana e considerando o aumento da corrida como exercício, atividade mundialmente popular, este tipo de esporte pode ser a causa de uma série de diferentes lesões. O pé, tornozelo e parte inferior da perna compreendem quase 40% das lesões. No entanto, a etiologia destas lesões permanece mal compreendida. OBJETIVO: investigar as causas do aparecimento da lesão de esforço em corredores. MÉTODOS: Uma busca sistemática foi realizada nas seguintes bases de dados: Bireme, PubMed e PEDro, selecionando-se ensaios clínicos, casos controle, estudos prospectivos e de corte transversal. RESULTADOS: A pesquisa através dos descritores rendeu 324 referências. Usando critérios de inclusão pré-definidos (estudos de casos, ensaios clínicos, estudos prospectivos e estudos transversais que abordavam adultos corredores indivíduos, amador ou profissional) permaneceram 68 artigos; 24 citações foram excluídos depois de ler o título, e 35 foram excluídos após a leitura do resumo e do texto integral. Portanto nove estudos que preencheram os critérios de análise foram incluídos. CONCLUSÃO: A etiologia das lesões de esforço em corredores é multifatorial. Esta revisão mostrou que a distância, tipo de solo e calçados, bem como uma história de lesões prévias, alterações biomecânicas como o aumento da dorsiflexão e eversão do tornozelo, e uma maior flexão do joelho são fatores de risco que influenciam a ocorrência dessas lesões.

INTRODUCTION: In spite of the numerous benefits to human health and given the increase of running as an exercise that has become popular worldwide, this type of sport may be the cause of a number of different injuries. The foot, ankle and lower leg comprise almost 40% of the injuries. However, the etiology of these types of injury is still not completely understood. OBJECTIVE: To investigate the causes of the onset of overuse injury in runners. METHODS: A systematic search of the electronic database was made: Bireme, Pubmed and PEDro, which were selected that addressed clinical trials, control cases, prospective and cross-sectional studies. RESULTS: The search through the descriptors yielded 324 references. Using our predefined inclusion criteria (case studies, clinical trials, prospective studies and cross studies that addressed adult runners, amateur or professional) 68 articles remained; 24 citations were excluded after reading the title, and 35 were excluded after reading the abstract and the full text. Therefore nine studies that met the criteria for analysis were included. CONCLUSION: The etiology of overuse injuries in runners is multifactorial. This review showed that distance, soil type and footwear, as well as a history of previous injuries, biomechanical changes such as increased dorsiflexion and eversion ankle, and greater knee flexion are risk factors that influence the occurrence of these injuries.

Abstract In the past thirty years, the development of compositional reservoir simulators using an equation of state (EOS) has been addressed in the literature. However, the development of compositional thermal simulators in conjunction with the EOS formulation, in particular, has not been addressed extensively. In this work, a fully implicit, thermal, compositional EOS-based simulator in conjunction with unstructured meshes has been developed. In this model, an equation of state is used for equilibrium calculations among phases. Also, the physical properties are calculated based on an EOS, hence obviating the need for using steam tables for calculation of water/steam properties. The governing equations for the model comprise fugacity equations, material balance, pore volume constraint and energy equation. The governing partial differential equations are solved using the EbFVM (Element based Finite Volume Method). Results for several case studies consisting of 2D and 3D reservoirs are presented in order to demonstrate the applicability of the method.

In compositional reservoir simulation, a set of non-linear partial differential equations must be solved. In this work, two numerical formulations are compared. The first formulation is based on an implicit pressure and explicit composition (IMPEC) procedure, and the second formulation uses an implicit pressure and implicit saturation (IMPSAT). The main goal of this work is to compare the formulations in terms of computational times for solving 2D and 3D compositional reservoir simulation case studies. In the comparison, both UDS (Upwind difference scheme) and third order TVD schemes were used. The computational results for the aforementioned formulations and the two interpolation functions are presented for several case studies involving homogeneous and heterogeneous reservoirs. Based on our comparison of IMPEC and IMPSAT formulations using several case studies presented in this work, the IMPSAT formulation was faster than the IMPEC formulation.

Em razão da curta duração de seu ciclo estral, ratas constituem bom modelo para o estudo das alterações que ocorrem durante o ciclo reprodutivo. O ciclo estral de ratas tem duração média de quatro ou cinco dias e é caracterizado por quatro fases, proestro, estro, metaestro e diestro, as quais podem ser determinadas pelos tipos celulares observados no esfregaço vaginal. Como a coleta da secreção vaginal e o uso de material corado geralmente são demorados, o objetivo deste trabalho foi fornecer aos pesquisadores algumas considerações úteis para a determinação das fases do ciclo estral de maneira rápida e prática. A secreção vaginal de trinta ratas foi coletada diariamente pela manhã, durante um mês, e o lavado vaginal não corado foi observado a fresco, em microscópio ótico, sem a utilização das lentes do condensador. O uso das objetivas de aumento de 10 vezes facilita a análise da proporção entre os três tipos celulares presentes no material. O uso das objetivas de aumento de 40 vezes permite o reconhecimento de cada um dos tipos celulares. Descrevemos o método utilizado, no qual a coleta do lavado vaginal, a observação do material e a identificação das fases do ciclo estral de 30 ratas podem ser realizados em 15-20 minutos.

The short length of the estrous cycle of rats makes them ideal for investigation of changes occurring during the reproductive cycle. The estrous cycle lasts four days and is characterized as: proestrus, estrus, metestrus and diestrus, which may be determined according to the cell types observed in the vaginal smear. Since the collection of vaginal secretion and the use of stained material generally takes some time, the aim of the present work was to provide researchers with some helpful considerations about the determination of the rat estrous cycle phases in a fast and practical way. Vaginal secretion of thirty female rats was collected every morning during a month and unstained native material was observed using the microscope without the aid of the condenser lens. Using the 10 x objective lens, it was easier to analyze the proportion among the three cellular types, which are present in the vaginal smear. Using the 40 x objective lens, it is easier to recognize each one of these cellular types. The collection of vaginal lavage from the animals, the observation of the material, in the microscope, and the determination of the estrous cycle phase of all the thirty female rats took 15-20 minutes.