Aplicações da teoria da percolação à modelagem e simulação de reservatórios de petróleo

In this thesis we study some problems related to petroleum reservoirs using methods and concepts of Statistical Physics. The thesis could be divided percolation problem in random multifractal support motivated by its potential application in modelling oil reservoirs. We develped an heterogeneous and anisotropic grid that followin two parts. The first one introduce a study of the percolations a random multifractal distribution of its sites. After, we determine the percolation threshold for this grid, the fractal dimension of the percolating cluster and the critical exponents ß and v. In the second part, we propose an alternative systematic of modelling and simulating oil reservoirs. We introduce a statistical model based in a stochastic formulation do Darcy Law. In this model, the distribution of permeabilities is localy equivalent to the basic model of bond percolation

Influência das propriedades estruturais e magnetostrictivas na dinâmica da magnetização de multicamadas magnéticas amorfas

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior

Estudo das propriedades magnéticas e estruturais do composto (Sm1 - xMMx)2Fe17 e seus nitretos

Conselho Nacional de Desenvolvimento Científico e Tecnológico

Cálculos AB initio de propriedades estruturais, eletrônicas e ópticas de colmpostos CaXo3 (X=Si, Ge, Sn)

In this work we present a study of structural, electronic and optical properties, at ambient conditions, of CaSiO3, CaGeO3 and CaSnO3 crystals, all of them a member of Ca-perovskite class. To each one, we have performed density functional theory ab initio calculations within LDA and GGA approximations of the structural parameters, geometry optimization, unit cell volume, density, angles and interatomic length, band structure, carriers effective masses, total and partial density of states, dielectric function, refractive index, optical absorption, reflectivity, optical conductivity and loss function. A result comparative procedure was done between LDA and GGA calculations, a exception to CaSiO3 where only LDA calculation was performed, due high computational cost that its low symmetry crystalline structure imposed. The Ca-perovskite bibliography have shown the absence of electronic structure calculations about this materials, justifying the present work

Equações preditivas para as pressões respiratórias máximas de crianças brasileiras

I ntroduction: The assessment of respiratory muscle strength is important in the diagnosis and monitoring of the respiratory muscles weakness of respiratory and neuromuscular diseases. However, there are still no studies that provide predictive equations and reference values for maximal respiratory pressures for children in our population. Aim: The purpose of this study was to propose predictive equations for maximal respiratory pressures in healthy school children. Method: This is an observational cross-sectional study. 144 healthy children were assessed. They were students from public and private schools in the city of Natal /RN (63 boys and 81 girls), subdivided in age groups of 7-8 and 9-11 years. The students presented the BMI, for age and sex, between 5 and 85 percentile. Maximal respiratory pressures were measured with the digital manometer MVD300 (Globalmed ®). The maximal inspiratory pressure (MIP) and maximal expiratory pressures (MEP) were measured from residual volume and total lung capacity, respectively. The data were analyzed using the SPSS Statistics 15.0 software (Statistical Package for Social Science) by assigning the significance level of 5%. Descriptive analysis was expressed as mean and standard deviation. T'Student test was used for unpaired comparison of averages of the variables. The comparison of measurements obtained with the predicted values in previous studies was performed using the paired t'Student test. The Pearson correlation test was used to verify the correlation of MRP's with the independent variables (age, sex, weight and height). For the equations analysis the stepwise linear regression was used. Results: By analyzing the data, we observed that in the age range studied MIP was significantly higher in boys. The MEP did not differ between boys and girls aged 7 to 8 years, the reverse occurred in the age between 9 and 11 years. The boys had a significant increase in respiratory muscle strength with advancing age. Regardless sex and age, MEP was always higher than the MIP. The reference values found in this study are similar to a sample of Spanish and Canadian children. The two models proposed in previous studies with children from other countries were not able to consistently predict the values observed in this studied population. The variables sex, age and weight correlated with MIP, whereas the MEP was also correlated with height. However, in the regression models proposed in this study, only gender and age were kept exerting influence on the variability of maximal inspiratory and expiratory pressures. Conclusion: This study provides reference values, lower limits of normality and proposes two models that allow predicting, through the independent variables, sex and age, the value of maximal static respiratory pressures in healthy children aged between 7 and 11 years old

Respostas morfogênicas e estruturais de gramíneas tropicais em regime de corte no nordeste brasileiro

The production of forage grasses is directly related to the morphogenesis. The knowledge of the morphogenetic and structural variables of forage plants is important for determining appropriate conditions of grazing livestock to ensure efficient and sustainable. Thus the objective of this study was to evaluate morphogenetic and structural responses of three genera of grasses, Brachiaria, Panicum and Cenchrus in a cutting regime. The experimental design was randomized blocks with three replications and six treatments. After each section were evaluated for forage production, appearance and elongation rates of leaves and stem, phyllochron, final leaf length, number of living leaves, leaf lifespan, leaf senescence rate, tiller density and tiller dynamics. On forage yield the highest values were obtained in cultivars Xaraes, Piata and Massai. The tiller density was higher for cv Massai. It is concluded that the cultivars of Panicum and Brachiaria had a higher tillering dynamics in increasing the turnover rate of tissues that are indicators of forage production, assuming that the cultivars of these genera are predisposed to use forage in the Northeast

Caracterização e modelagem dos sistemas de produção de caprinos leiteiros

The objectives of this research were characterizing the dairy goat production systems and model it using linear program. On the first step of this research, the model was developed using data from farms that was affiliated in the ACCOMIG/Caprileite, used a similar dairy goat production systems and have a partnership program with Universidade Federal de Minas Gerais . The data of research were from a structured questionnaire applied with farmers and monitoring of production systems during a guided visit on their farms. The results permitted identify that all farms were classified as a small and have a intensive production system. The average herd size had 63.75 dairy goats on lactation; it permits a production of 153, 38 kg of goat milk per day. It was observed that existing more than one channel of commercialization for the goat milk and their derivative products. The data obtained, on the first step of this research, was used to develop a linear program model. It was evaluated in two goat production systems, called P1 and P2. The results showed that the P1 system, with an annual birth and lactation during approximately 300 days was the best alternative for business. These results were compared with a mixed (beef and dairy) goat system in the semiarid region, which indicated merged with both systems. Therefore, to achieve profits and sustainability of the system, in all simulations it was necessary a minimum limit of funding of U.S. $ 10,000.00; this value permit earning of U.S. $ 792.00 per month and pay the investment within 5 years

Remoção, por flotação, de óleo em águas produzidas na indústria de petróleo: eficiência e modelagem do processo

The separation oil-water by the use of flotation process is characterized by the involvement between the liquid and gas phases. For the comprehension of this process, it s necessary to analyze the physical and chemical properties command float flotation, defining the nature and forces over the particles. The interface chemistry has an important role on the flotation technology once, by dispersion of a gas phase into a liquid mixture the particles desired get stuck into air bubbles, being conduced to a superficial layer where can be physically separated. Through the study of interface interaction involved in the system used for this work, was possible to apply the results in an mathematical model able to determine the probability of flotation using a different view related to petroleum emulsions such as oil-water. The terms of probability of flotation correlate the collision and addition between particles of oil and air bubbles, that as more collisions, better is the probability of flotation. The additional probability was analyzed by the isotherm of absorption from Freundlich, represents itself the add probability between air bubbles and oil particles. The mathematical scheme for float flotation involved the injected air flow, the size of bubbles and quantity for second, the volume of float cell, viscosity of environment and concentration of demulsifier. The results shown that the float agent developed by castor oil, pos pH variation, salt quantity, temperature, concentration and water-oil quantity, presented efficient extraction of oil from water, up to 95%, using concentrations around 11 ppm of demulsifier. The best results were compared to other commercial products, codified by ―W‖ and ―Z‖, being observed an equivalent demulsifier power between Agflot and commercial product ―W‖ and superior to commercial product ―Z‖

Uma linguagem de modelagem da interação para auxiliar a comunicação designer-usuário

The development of interactive systems involves several professionals and the integration between them normally uses common artifacts, such as models, that drive the development process. In the model-driven development approach, the interaction model is an artifact that includes the most of the aspects related to what and how the user can do while he/she interacting with the system. Furthermore, the interactive model may be used to identify usability problems at design time. Therefore, the central problematic addressed by this thesis is twofold. In the first place, the interaction modeling, in a perspective that helps the designer to explicit to developer, who will implement the interface, the aspcts related to the interaction process. In the second place, the anticipated identification of usability problems, that aims to reduce the application final costs. To achieve these goals, this work presents (i) the ALaDIM language, that aims to help the designer on the conception, representation and validation of his interactive message models; (ii) the ALaDIM editor, which was built using the EMF (Eclipse Modeling Framework) and its standardized technologies by OMG (Object Management Group); and (iii) the ALaDIM inspection method, which allows the anticipated identification of usability problems using ALaDIM models. ALaDIM language and editor were respectively specified and implemented using the OMG standards and they can be used in MDA (Model Driven Architecture) activities. Beyond that, we evaluated both ALaDIM language and editor using a CDN (Cognitive Dimensions of Notations) analysis. Finally, this work reports an experiment that validated the ALaDIM inspection method

Visual IMML: um perfil UML para a modelagem de interfaces de usuário

The software development processes proposed by the most recent approaches in Software Engineering make use old models. UML was proposed as the standard language for modeling. The user interface is an important part of the software and has a fundamental importance to improve its usability. Unfortunately the standard UML does not offer appropriate resources to model user interfaces. Some proposals have already been proposed to solve this problem: some authors have been using models in the development of interfaces (Model Based Development) and some proposals to extend UML have been elaborated. But none of them considers the theoretical perspective presented by the semiotic engineering, that considers that, through the system, the designer should be able to communicate to the user what he can do, and how to use the system itself. This work presents Visual IMML, an UML Profile that emphasizes the aspects of the semiotic engineering. This Profile is based on IMML, that is a declarative textual language. The Visual IMML is a proposal that aims to improve the specification process by using a visual modeling (using diagrams) language. It proposes a new set of modeling elements (stereotypes) specifically designed to the specification and documentation of user interfaces, considering the aspects of communication, interaction and functionality in an integrated manner

Em direção a uma representação para equações algébricas :uma lógica equacional local

The intervalar arithmetic well-known as arithmetic of Moore, doesn't possess the same properties of the real numbers, and for this reason, it is confronted with a problem of operative nature, when we want to solve intervalar equations as extension of real equations by the usual equality and of the intervalar arithmetic, for this not to possess the inverse addictive, as well as, the property of the distributivity of the multiplication for the sum doesn t be valid for any triplet of intervals. The lack of those properties disables the use of equacional logic, so much for the resolution of an intervalar equation using the same, as for a representation of a real equation, and still, for the algebraic verification of properties of a computational system, whose data are real numbers represented by intervals. However, with the notion of order of information and of approach on intervals, introduced by Acióly[6] in 1991, the idea of an intervalar equation appears to represent a real equation satisfactorily, since the terms of the intervalar equation carry the information about the solution of the real equation. In 1999, Santiago proposed the notion of simple equality and, later on, local equality for intervals [8] and [33]. Based on that idea, this dissertation extends Santiago's local groups for local algebras, following the idea of Σ-algebras according to (Hennessy[31], 1988) and (Santiago[7], 1995). One of the contributions of this dissertation, is the theorem 5.1.3.2 that it guarantees that, when deducing a local Σ-equation E t t in the proposed system SDedLoc(E), the interpretations of t and t' will be locally the same in any local Σ-algebra that satisfies the group of fixed equations local E, whenever t and t have meaning in A. This assures to a kind of safety between the local equacional logic and the local algebras

AutoWebS: um Ambiente para Modelagem e Geração Automática de ServiçosWeb Semânticos

Typically Web services contain only syntactic information that describes their interfaces. Due to the lack of semantic descriptions of the Web services, service composition becomes a difficult task. To solve this problem, Web services can exploit the use of ontologies for the semantic definition of service s interface, thus facilitating the automation of discovering, publication, mediation, invocation, and composition of services. However, ontology languages, such as OWL-S, have constructs that are not easy to understand, even for Web developers, and the existing tools that support their use contains many details that make them difficult to manipulate. This paper presents a MDD tool called AutoWebS (Automatic Generation of Semantic Web Services) to develop OWL-S semantic Web services. AutoWebS uses an approach based on UML profiles and model transformations for automatic generation of Web services and their semantic description. AutoWebS offers an environment that provides many features required to model, implement, compile, and deploy semantic Web services

LWiSSy: uma linguagem específica de domínio para modelagem de sistemas de redes de sensores e atuadores sem fio

The field of Wireless Sensor and Actuator Networks (WSAN) is fast increasing and has attracted the interest of both the research community and the industry because of several factors, such as the applicability of such networks in different application domains (aviation, civil engineering, medicine, and others). Moreover, advances in wireless communication and the reduction of hardware components size also contributed for a fast spread of these networks. However, there are still several challenges and open issues that need to be tackled in order to achieve the full potential of WSAN usage. The development of WSAN systems is one of the most relevant of these challenges considering the number of variables involved in this process. Currently, a broad range of WSAN platforms and low level programming languages are available to build WSAN systems. Thus, developers need to deal with details of different sensor platforms and low-level programming abstractions of sensor operational systems on one hand, and they also need to have specific (high level) knowledge about the distinct application domains, on the other hand. Therefore, in order to decouple the handling of these two different levels of knowledge, making easier the development process of WSAN systems, we propose LWiSSy (Domain Language for Wireless Sensor and Actuator Networks Systems), a domain specific language (DSL) for WSAN. The use of DSLs raises the abstraction level during the programming of systems and modularizes the system building in several steps. Thus, LWiSSy allows the domain experts to directly contribute in the development of WSANs without having knowledge on low level sensor platforms, and network experts to program sensor nodes to meet application requirements without having specific knowledge on the application domain. Additionally, LWiSSy enables the system decomposition in different levels of abstraction according to structural and behavioral features and granularities (network, node group and single node level programming)

PUPSI :uma proposta de processo unificado para políticas de segurança da informação

The way to deal with information assets means nowadays the main factor not only for the success but also for keeping the companies in the global world. The number of information security incidents has grown for the last years. The establishment of information security policies that search to keep the security requirements of assets in the desired degrees is the major priority for the companies. This dissertation suggests a unified process for elaboration, maintenance and development of information security policies, the Processo Unificado para Políticas de Segurança da Informação - PUPSI. The elaboration of this proposal started with the construction of a structure of knowledge based on documents and official rules, published in the last two decades, about security policies and information security. It's a model based on the examined documents which defines the needed security policies to be established in the organization, its work flow and identifies the sequence of hierarchy among them. It's also made a model of the entities participating in the process. Being the problem treated by the model so complex, which involves all security policies that the company must have. PUPSI has an interative and developing approach. This approach was obtained from the instantiation of the RUP - Rational Unified Process model. RUP is a platform for software development object oriented, of Rational Software (IBM group). Which uses the best practice known by the market. PUPSI got from RUP a structure of process that offers functionality, diffusion capacity and comprehension, performance and agility for the process adjustment, offering yet capacity of adjustment to technological and structural charges of the market and the company

Modelagem de arquiteturas reconfiguráveis com espaços de Chu

The Reconfigurables Architectures had appeares as an alternative to the ASICs and the GGP, keeping a balance between flexibility and performance. This work presents a proposal for the modeling of Reconfigurables with Chu Spaces, describing the subjects main about this thematic. The solution proposal consists of a modeling that uses a generalization of the Chu Spaces, called of Chu nets, to model the configurations of a Reconfigurables Architectures. To validate the models, three algorithms had been developed and implemented to compose configurable logic blocks, detection of controllability and observability in applications for Reconfigurables Architectures modeled by Chu nets