Ambiente para aquisi����o e processamento de sinal eletromiogr��fico de superf��cie

In this work, a platform to the conditioning, digitizing, visualization and recording of the EMG signals was developed. After the acquisition, the analysis can be done by signal processing techniques. The platform consists of two modules witch acquire electromyography (EMG) signals by surface electrodes, limit the interest frequency band, filter the power grid interference and digitalize the signals by the analogue-to- digital converter of the modules microcontroller. Thereby, the data are sent to the computer by the USB interface by the HID specification, displayed in real-time in graphical form and stored in files. As processing resources was implemented the operations of signal absolute value, the determination of effective value (RMS), Fourier analysis, digital filter (IIR) and the adaptive filter. Platform initial tests were performed with signal of lower and upper limbs with the aim to compare the EMG signal laterality. The open platform is intended to educational activities and academic research, allowing the addition of other processing methods that the researcher want to evaluate or other required analysis.

M��todo para reconhecimento de vogais e extra����o de par��metros ac��sticos para analises forenses

Forensic speaker comparison exams have complex characteristics, demanding a long time for manual analysis. A method for automatic recognition of vowels, providing feature extraction for acoustic analysis is proposed, aiming to contribute as a support tool in these exams. The proposal is based in formant measurements by LPC (Linear Predictive Coding), selectively by fundamental frequency detection, zero crossing rate, bandwidth and continuity, with the clustering being done by the k-means method. Experiments using samples from three different databases have shown promising results, in which the regions corresponding to five of the Brasilian Portuguese vowels were successfully located, providing visualization of a speaker���s vocal tract behavior, as well as the detection of segments corresponding to target vowels.

Adapta����o do paradigma orientado a notifica����es para desenvolvimento de sistemas fuzzy

This work proposes to adjust the Notification Oriented Paradigm (NOP) so that it provides support to fuzzy concepts. NOP is inspired by elements of imperative and declarative paradigms, seeking to solve some of the drawbacks of both. By decomposing an application into a network of smaller computational entities that are executed only when necessary, NOP eliminates the need to perform unnecessary computations and helps to achieve better logical-causal uncoupling, facilitating code reuse and application distribution over multiple processors or machines. In addition, NOP allows to express the logical-causal knowledge at a high level of abstraction, through rules in IF-THEN format. Fuzzy systems, in turn, perform logical inferences on causal knowledge bases (IF-THEN rules) that can deal with problems involving uncertainty. Since PON uses IF-THEN rules in an alternative way, reducing redundant evaluations and providing better decoupling, this research has been carried out to identify, propose and evaluate the necessary changes to be made on NOP allowing to be used in the development of fuzzy systems. After that, two fully usable materializations were created: a C++ framework, and a complete programming language (LingPONFuzzy) that provide support to fuzzy inference systems. From there study cases have been created and several tests cases were conducted, in order to validate the proposed solution. The test results have shown a significant reduction in the number of rules evaluated in comparison to a fuzzy system developed using conventional tools (frameworks), which could represent an improvement in performance of the applications.

S��ntese de ze��lita A a partir de diatomita como fonte de aluminossilicato

The synthesis of zeolites from natural sources of silicon and aluminum are promising alternative routes to obtain porous or zeolite MCM family. Such materials are typically used in catalytic processes and / or adsorption is to obtain new products or for separation and purification processes thereof. Environmental legislation is becoming stricter and requires the use of materials more efficient, aiming to achieve pollution prevention, by gas or liquid contaminants in the environment. In order to obtain a material with environmentally friendly features, this study aimed at the synthesis of zeolite A, from an amorphous sediment, diatomite, which is found in abundance in the northeast region of Brazil, may be substituted for conventional products the production of zeolite, involving higher costs. The methodology for obtaining the "Zeolite A" using as a source of silica and alumina diatomite is simple, since this is a source of silicon, not requiring therefore a structural driver, but also by heat treatment, only drying conventional to remove water. The "zeolite A" was obtained from diatomite, but as an intermediate step we obtained the sodalite. The characterization was made by the following techniques: EDX, XRD, FT-IR, SEM and determining a specific area by the BET method and the BJH method for checking the diameter of pores. By characterization of the obtained material was first demonstrated the achievement of sodalite and after modification of the same, there was obtained zeolite A

An��lise gr��fica de estruturas porosas sobre a ��tica da estereologia

In this work we developed a computer simulation program for physics porous structures based on programming language C + + using a Geforce 9600 GT with the PhysX chip, originally developed for video games. With this tool, the ability of physical interaction between simulated objects is enlarged, allowing to simulate a porous structure, for example, reservoir rocks and structures with high density. The initial procedure for developing the simulation is the construction of porous cubic structure consisting of spheres with a single size and with varying sizes. In addition, structures can also be simulated with various volume fractions. The results presented are divided into two parts: first, the ball shall be deemed as solid grains, ie the matrix phase represents the porosity, the second, the spheres are considered as pores. In this case the matrix phase represents the solid phase. The simulations in both cases are the same, but the simulated structures are intrinsically different. To validate the results presented by the program, simulations were performed by varying the amount of grain, the grain size distribution and void fraction in the structure. All results showed statistically reliable and consistent with those presented in the literature. The mean values and distributions of stereological parameters measured, such as intercept linear section of perimeter area, sectional area and mean free path are in agreement with the results obtained in the literature for the structures simulated. The results may help the understanding of real structures.

Uma janela tropical: an��lise do desempenho luminoso de ambientes com aberturas sombreadas para o clima de Natal/RN

This master thesis introduces assessment procedures of daylighting performance in office rooms with shaded opening, recommendations for Natal-RN (Latitude 05,47' S, Longitude 35,11' W). The studies assume the need of window exterior shading in hot and humid climate buildings. The daylighting performance analyses are based on simulated results for three levels of illuminance (300,500 e 1000 lux) between 08h00 e 16h00, in rooms with 2,80 m height, 6 m large and 4 m, 6 m e 8 m depths, with a centered single opening, window wall ratio (20%, 40% e 60%), four orientations (North, East, South and West), and two types of sky (clear and partially cloudy). The sky characteristics were statistically determined based on hourly data from INPE-CRN solar and daylighting weather station. The lighting performance is resulted from dynamic computer simulation of 72 models using Troplux 3.12. The simulation results were assessed using a new parameter to quantify the use of interior daylighting, the useful percentage of daylight (PULN), which corresponds to the time fraction with satisfactory light, in accordance with the illuminance design. The passive zone depths are defined based on the PULN. Despite the failures of illuminance data from the weather station, the analyses ratified the high potential of daylighting for shaded rooms. The most influential variables on the lighting performance are the opening size and the illuminance of design, while the orientation is a little influential

Estabilidade de métodos num��ricos LCR para a simulação de escoamento

P��s-gradua����o em Matematica Aplicada e Computacional - FCT

Simulação do escoamento multif��sico no interior de bombas de cavidades progressivas met��licas

The progressing cavity pumping (PCP) is one of the most applied oil lift methods nowadays in oil extraction due to its ability to pump heavy and high gas fraction flows. The computational modeling of PCPs appears as a tool to help experiments with the pump and therefore, obtain precisely the pump operational variables, contributing to pump s project and field operation otimization in the respectively situation. A computational model for multiphase flow inside a metallic stator PCP which consider the relative motion between rotor and stator was developed in the present work. In such model, the gas-liquid bubbly flow pattern was considered, which is a very common situation in practice. The Eulerian-Eulerian approach, considering the homogeneous and inhomogeneous models, was employed and gas was treated taking into account an ideal gas state. The effects of the different gas volume fractions in pump volumetric eficiency, pressure distribution, power, slippage flow rate and volumetric flow rate were analyzed. The results shown that the developed model is capable of reproducing pump dynamic behaviour under the multiphase flow conditions early performed in experimental works

Estudo experimental de trincheiras de infiltra����o no controle da gera����o do escoamento superficial

A crescente urbaniza����o observada nas ��ltimas d��cadas tem sido acompanhada por problemas relacionados a quase todos aspectos da infra-estrutura urbana. No que se refere �� drenagem pluvial, a situa����o n��o �� diferente. A impermeabiliza����o gerada pelo processo de urbaniza����o faz com que os hidrogramas se tornem progressivamente mais cr��ticos, com maiores volumes escoados, maiores vaz��es de pico e menores tempos de escoamento. Agravando esta situa����o, o sistema tradicional de drenagem, baseado na m��xima ���pegar e largar depressa���, busca a elimina����o da ��gua, o mais r��pido poss��vel, atrav��s de galerias, condutos enterrados e canaliza����es, significando, muitas vezes, a simples transfer��ncia da cheia para as se����es de jusante. A solu����o cl��ssica para o problema das cheias baseiase na amplia����o do sistema e/ou aumento da efici��ncia das redes, com custos geralmente elevados. Este trabalho apresenta um estudo experimental efetuado em trincheiras de infiltra����o, dentro de uma filosofia compensat��ria dos efeitos da urbaniza����o. Esses dispositivos se inserem dentro de um conceito ambiental da drenagem urbana, onde se busca n��o mais a elimina����o da ��gua o mais rapidamente poss��vel, mas sua valoriza����o dentro do espa��o urbano, atrav��s de dispositivos bem integrados e, preferencialmente, multifuncionais. Duas trincheiras de infiltra����o foram instaladas e monitoradas em uma ��rea do IPH-UFRGS. A implanta����o das trincheiras baseou-se na adapta����o, para as condi����es brasileiras, de t��cnicas descritas na literatura, principalmente no que se refere aos métodos construtivos e materiais utilizados, assim como aos métodos e crit��rios de utiliza����o e dimensionamento. Durante o per��odo de monitoramento e an��lise de dados, foram avaliados e discutidos aspectos relacionados a: condi����es de funcionamento, tais como magnitude do evento pluviom��trico e condi����es antecedentes de umidade do solo; efici��ncia dos dispositivos; ocorr��ncia de escoamento preferencial; custos; limita����es de aplica����o. Aspectos relacionados ao funcionamento do dispositivo ao longo do per��odo de monitoramento s��o tamb��m discutidos, buscando avaliar seu desempenho a longo prazo, apesar do curto per��odo de observa����o. Adicionalmente, um modelo num��rico de simulação do funcionamento quantitativo de dispositivos de infiltra����o foi testado (modelo de Bouwer), sendo sugeridas modifica����es para torn��-lo mais abrangente. As duas trincheiras mostraram-se eficientes, controlando 100% do volume escoado, mesmo para eventos de per��odo de retorno superiores aos de projeto. Verificou-se que a metodologia de projeto gera super-dimensionamento das estruturas e que as condi����es iniciais de umidade do solo e as caracter��sticas dos eventos s��o fatores determinantes para seu funcionamento. Durante os 33 meses de observa����o da trincheira I e os 6 meses da trincheira II, n��o houve altera����es significativas do funcionamento. Os eventos monitorados na trincheira I indicam a ocorr��ncia de escoamento preferencial. Um ensaio destrutivo refor��ou esta hip��tese, al��m de mostrar acentuado grau de colmata����o da primeira camada, em fun����o do excessivo aporte de material em suspens��o. Recomenda����es para utiliza����o deste tipo de solu����o s��o apresentadas, visando estimular seu uso.

Caracteriza����o, simulação (�� escala) e modela����o do escoamento em canais artificiais: aplica����o a caso de estudo

Os escoamentos no interior de zonas urbanas, apresentam grande heterogeneidade, pelo que a sua caracteriza����o, requer uma formula����o que incorpore explicitamente essa variabilidade espacial. A caracteriza����o, simulação (�� escala) e modela����o do escoamento em canais artificiais e a aplica����o a um caso de estudo, no Laborat��rio de Hidr��ulica da UMa, representa o cerne desta disserta����o. Os objetivos principais desta disserta����o s��o: a caracteriza����o e desenvolvimento de ferramentas de simulação do comportamento do escoamento em canais artificiais, no caso de uma varia����o s��bita dos caudais afluentes, mecanismos de preven����o de cheia; o desenvolvimento de um modelo de simulação hidrodin��mico, considerando os escoamentos vari��veis em superf��cie livre no caso de situa����es de cheia, na simulação entre as condi����es vari��veis das aflu��ncias, das condi����es hidromorfol��gicas do canal e da instala����o e opera����o dos sistemas e regula����o dos escoamentos; e ainda a an��lise da viabilidade da simulação (modelo) na gest��o e preven����o de cheias em canais artificiais. Numa primeira inst��ncia, procede-se �� recolha de toda a informa����o bibliogr��fica dispon��vel. Com recurso aos modelos digitais do terreno e ao programa ArcGis, �� efetuada toda uma exaustiva caracteriza����o da bacia hidrogr��fica, relativa ao caso de estudo (canal artificial), a partir da qual foi poss��vel obter os dados inerentes ��s caracter��sticas geom��tricas, caracter��sticas de relevo e caracter��sticas de drenagem. Segue-se a an��lise da precipita����o com recurso a folhas de c��lculo e dados fornecidos pelas institui����es pertinentes, de forma a obter valores de precipita����o m��dia di��ria e anual para aplica����o de f��rmulas, tanto para calcular valores de tempo de concentra����o, bem como caudais. O pr��ximo passo �� selecionar os tro��os relevantes do canal em estudo e com recurso ao equipamento dispon��vel no Laborat��rio de Hidr��ulica da UMa, �� folha de c��lculo programada e ao programa HEC-RAS procede-se �� simulação/modela����o/an��lise desses tro��os, comparando o resultado/comportamento simulado, com o expect��vel e entre os v��rios métodos. Por fim, s��o expostas as conclus��es, bem como algumas considera����es finais e uma listagem de objetivos a manter ou alcan��ar nos pr��ximos anos, onde se incluem, a����es priorit��rias e recomenda����es visando, n��o s�� melhorar o processo de caracteriza����o do escoamento em canais artificiais, bem como simplificar a preven����o e gest��o de cheias.

Simulação do escoamento monof��sico em um est��gio de uma bomba centr��fuga utilizando t��cnicas de fluidodin��mica computacional

Oil production and exploration techniques have evolved in the last decades in order to increase fluid flows and optimize how the required equipment are used. The base functioning of Electric Submersible Pumping (ESP) lift method is the use of an electric downhole motor to move a centrifugal pump and transport the fluids to the surface. The Electric Submersible Pumping is an option that has been gaining ground among the methods of Artificial Lift due to the ability to handle a large flow of liquid in onshore and offshore environments. The performance of a well equipped with ESP systems is intrinsically related to the centrifugal pump operation. It is the pump that has the function to turn the motor power into Head. In this present work, a computer model to analyze the three-dimensional flow in a centrifugal pump used in Electric Submersible Pumping has been developed. Through the commercial program, ANSYS�� CFX��, initially using water as fluid flow, the geometry and simulation parameters have been defined in order to obtain an approximation of what occurs inside the channels of the impeller and diffuser pump in terms of flow. Three different geometry conditions were initially tested to determine which is most suitable to solving the problem. After choosing the most appropriate geometry, three mesh conditions were analyzed and the obtained values were compared to the experimental characteristic curve of Head provided by the manufacturer. The results have approached the experimental curve, the simulation time and the model convergence were satisfactory if it is considered that the studied problem involves numerical analysis. After the tests with water, oil was used in the simulations. The results were compared to a methodology used in the petroleum industry to correct viscosity. In general, for models with water and oil, the results with single-phase fluids were coherent with the experimental curves and, through three-dimensional computer models, they are a preliminary evaluation for the analysis of the two-phase flow inside the channels of centrifugal pump used in ESP systems

Simulação de fluxo de fluidos em meios porosos desordenados uma an��lise de efeito de escala na estimativa da permeabilidade e do coeficiente de arrasto

The present study provides a methodology that gives a predictive character the computer simulations based on detailed models of the geometry of a porous medium. We using the software FLUENT to investigate the flow of a viscous Newtonian fluid through a random fractal medium which simplifies a two-dimensional disordered porous medium representing a petroleum reservoir. This fractal model is formed by obstacles of various sizes, whose size distribution function follows a power law where exponent is defined as the fractal dimension of fractionation Dff of the model characterizing the process of fragmentation these obstacles. They are randomly disposed in a rectangular channel. The modeling process incorporates modern concepts, scaling laws, to analyze the influence of heterogeneity found in the fields of the porosity and of the permeability in such a way as to characterize the medium in terms of their fractal properties. This procedure allows numerically analyze the measurements of permeability k and the drag coefficient Cd proposed relationships, like power law, for these properties on various modeling schemes. The purpose of this research is to study the variability provided by these heterogeneities where the velocity field and other details of viscous fluid dynamics are obtained by solving numerically the continuity and Navier-Stokes equations at pore level and observe how the fractal dimension of fractionation of the model can affect their hydrodynamic properties. This study were considered two classes of models, models with constant porosity, MPC, and models with varying porosity, MPV. The results have allowed us to find numerical relationship between the permeability, drag coefficient and the fractal dimension of fractionation of the medium. Based on these numerical results we have proposed scaling relations and algebraic expressions involving the relevant parameters of the phenomenon. In this study analytical equations were determined for Dff depending on the geometrical parameters of the models. We also found a relation between the permeability and the drag coefficient which is inversely proportional to one another. As for the difference in behavior it is most striking in the classes of models MPV. That is, the fact that the porosity vary in these models is an additional factor that plays a significant role in flow analysis. Finally, the results proved satisfactory and consistent, which demonstrates the effectiveness of the referred methodology for all applications analyzed in this study.

Simulação computacional do escoamento em bombas de cavidades progressivas

The use of Progressing Cavity Pumps (PCPs) in artificial lift applications in low deep wells is becoming more common in the oil industry, mainly, due to its ability to pump heavy oils, produce oil with large concentrations of sand, besides present high efficiency when compared to other artificial lift methods. Although this system has been widely used as an oil lift method, few investigations about its hydrodynamic behavior are presented, either experimental or numeric. Therefore, in order to increase the knowledge about the BCP operational behavior, this work presents a novel computational model for the 3-D transient flow in progressing cavity pumps, which includes the relative motion between rotor and stator, using an element based finite volume method. The model developed is able to accurately predict the volumetric efficiency and viscous looses as well as to provide detailed information of pressure and velocity fields inside the pump. In order to predict PCP performance for low viscosity fluids, advanced turbulence models were used to treat, accurately, the turbulent effects on the flow, which allowed for obtaining results consistent with experimental values encountered in literature. In addition to the 3D computational model, a simplified model was developed, based on mass balance within cavities and on simplification on the momentum equations for fully developed flow along the seal region between cavities. This simplified model, based on previous approaches encountered in literature, has the ability to predict flow rate for a given differential pressure, presenting exactness and low CPU requirements, becoming an engineering tool for quick calculations and providing adequate results, almost real-time time. The results presented in this work consider a rigid stator PCP and the models developed were validated against experimental results from open literature. The results for the 3-D model showed to be sensitive to the mesh size, such that a numerical mesh refinement study is also presented. Regarding to the simplified model, some improvements were introduced in the calculation of the friction factor, allowing the application fo the model for low viscosity fluids, which was unsuccessful in models using similar approaches, presented in previous works

Estudo de materiais supercondutores em forma de SQUID com uma constri����o usando métodos de paraleliza����o computacional

P��s-gradua����o em Ci��ncia e Tecnologia de Materiais - FC

Simulação do escoamento monof��sico em um est��gio de uma bomba centr��fuga utilizando t��cnicas de fluidodin��mica computacional

Oil production and exploration techniques have evolved in the last decades in order to increase fluid flows and optimize how the required equipment are used. The base functioning of Electric Submersible Pumping (ESP) lift method is the use of an electric downhole motor to move a centrifugal pump and transport the fluids to the surface. The Electric Submersible Pumping is an option that has been gaining ground among the methods of Artificial Lift due to the ability to handle a large flow of liquid in onshore and offshore environments. The performance of a well equipped with ESP systems is intrinsically related to the centrifugal pump operation. It is the pump that has the function to turn the motor power into Head. In this present work, a computer model to analyze the three-dimensional flow in a centrifugal pump used in Electric Submersible Pumping has been developed. Through the commercial program, ANSYS�� CFX��, initially using water as fluid flow, the geometry and simulation parameters have been defined in order to obtain an approximation of what occurs inside the channels of the impeller and diffuser pump in terms of flow. Three different geometry conditions were initially tested to determine which is most suitable to solving the problem. After choosing the most appropriate geometry, three mesh conditions were analyzed and the obtained values were compared to the experimental characteristic curve of Head provided by the manufacturer. The results have approached the experimental curve, the simulation time and the model convergence were satisfactory if it is considered that the studied problem involves numerical analysis. After the tests with water, oil was used in the simulations. The results were compared to a methodology used in the petroleum industry to correct viscosity. In general, for models with water and oil, the results with single-phase fluids were coherent with the experimental curves and, through three-dimensional computer models, they are a preliminary evaluation for the analysis of the two-phase flow inside the channels of centrifugal pump used in ESP systems