9 resultados para problem solution fit
em Universidade Federal do Rio Grande do Norte(UFRN)
Resumo:
Injectivity decline, which can be caused by particle retention, generally occurs during water injection or reinjection in oil fields. Several mechanisms, including straining, are responsible for particle retention and pore blocking causing formation damage and injectivity decline. Predicting formation damage and injectivity decline is essential in waterflooding projects. The Classic Model (CM), which incorporates filtration coefficients and formation damage functions, has been widely used to predict injectivity decline. However, various authors have reported significant discrepancies between Classical Model and experimental results, motivating the development of deep bed filtration models considering multiple particle retention mechanisms (Santos & Barros, 2010; SBM). In this dissertation, inverse problem solution was studied and a software for experimental data treatment was developed. Finally, experimental data were fitted using both the CM and SBM. The results showed that, depending on the formation damage function, the predictions for injectivity decline using CM and SBM models can be significantly different
Resumo:
This work contains the problematic of sub-education among the population that was excluded from school attendance in the regular time, contributing to knowledge production about educational practices developed in EJA (the Young and Adult Education). It focuses on the Pedagogical proposal and on the experience in young and adult literacy in the context of the mobilization of people affected by dam building. It depicts the international, national and regional mobilization against huge dams building and the emergence of the Movement of Dam Affected People (MAB), highlighting their general project and registering their teaching performance, particularly in young and adult literacy. In methodological and theoretical approaches, two interconnected categories are considered: the historical entirety, essentially theoretical, and the young and adult education practice. Based on the entirety, it outlines a contextualized explanation about the stakeholder s situation and, respecting the second category, which is part of the first one, places literacy as one of the basic aspects of an omnilateral man upbringing. The study broaches a wide context of dams in the world, placing the socio-environmental effects resulting from dams building in Brazil, in Northeast region and in Paraíba, and emphasizing the consequences of Acauã Dam building in the Paraíba cities of Aroeiras, Itatuba and Natuba. It presents the particular context of the population affected by Acauã, summarizing a panoramic view about the involved Paraíba cities and learning the conditions of residents relocation. It appraises the educational project and the National-MAB literacy proposal, operationalized by Paraíba-MAB in resettlements sited on Acauã s surroundings. It ensures that, besides public policies including financing, the feasibility of literacy problem solution can be completed with Pedagogical actions attached to the target people peculiarities and immediate necessities, respecting actions connected through one comprehensive and contextualized educational project. It evaluates the young and adult literacy project developed in the restricted Paraíba-MAB area, as an example of a Pedagogical action minimally contextualized. Eventually, it recommends researchers and teachers in general, that are committed to this work perspective, to pay attention to the way they articulate discussions and participation, so as to contemplate these communities expectations and necessities in Pedagogical projects and spaces based on discussion, dialogue and collective reflection
Resumo:
Microstrip antennas are widely used in modern telecommunication systems. This is particularly due to the great variety of geometries and because they are easily built and integrated to other high frequency devices and circuits. This work presents a study of the properties of the microstrip antenna with an aperture impressed in the conducting patch. Besides, the analysis is performed for isotropic and anisotropic dielectric substrates. The Multiport Network Model MNM is used in combination with the Segmentation Method and the Greens function technique in the analysis of the considered microstrip antenna geometries. The numerical analysis is performed by using the boundary value problem solution, by considering separately the impedance matrix of the structure segments. The analysis for the complete structure is implemented by choosing properly the number and location of the neighboor element ports. The numerial analysis is performed for the following antenna geometries: resonant cavity, microstrip rectangular patch antenna, and microstrip rectangular patch antenna with aperture. The analysis is firstly developed for microstrip antennas on isotropic substrates, and then extended to the case of microstrip antennas on anisotropic substrates by using a Mapping Method. The experimental work is described and related to the development of several prototypes of rectangular microstrip patch antennas wtih and without rectangular apertures. A good agreement was observed between the simulated and measured results. Thereafter, a good agreement was also observed between the results of this work and those shown in literature for microstrip antennas on isotropic substrates. Furthermore, results are proposed for rectangular microstrip patch antennas wtih rectangular apertures in the conducting patch
Resumo:
Injectivity decline, which can be caused by particle retention, generally occurs during water injection or reinjection in oil fields. Several mechanisms, including straining, are responsible for particle retention and pore blocking causing formation damage and injectivity decline. Predicting formation damage and injectivity decline is essential in waterflooding projects. The Classic Model (CM), which incorporates filtration coefficients and formation damage functions, has been widely used to predict injectivity decline. However, various authors have reported significant discrepancies between Classical Model and experimental results, motivating the development of deep bed filtration models considering multiple particle retention mechanisms (Santos & Barros, 2010; SBM). In this dissertation, inverse problem solution was studied and a software for experimental data treatment was developed. Finally, experimental data were fitted using both the CM and SBM. The results showed that, depending on the formation damage function, the predictions for injectivity decline using CM and SBM models can be significantly different
Resumo:
Heavy metals are used in many industrial processestheirs discard can harm fel effects to the environment, becoming a serious problem. Many methods used for wastewater treatment have been reported in the literature, but many of them have high cost and low efficiency. The adsorption process has been used as effective for the metal remoal ions. This paper presents studies to evaluate the adsorption capacity of vermiculite as adsorbent for the heavy metals removal in a synthetic solution. The mineral vermiculite was characterized by differents techniques: specific surface area analysis by BET method, X-ray diffraction, raiosX fluorescence, spectroscopy in the infraredd region of, laser particle size analysis and specific gravity. The physical characteristics of the material presented was appropriate for the study of adsorption. The adsorption experiments weredriveal finite bath metod in synthetic solutions of copper, nickel, cadmium, lead and zinc. The results showed that the vermiculite has a high potential for adsorption, removing about 100% of ions and with removal capacity values about 85 ppm of metal in solution, 8.09 mg / g for cadmium, 8.39 mg/g for copper, 8.40 mg/g for lead, 8.26 mg/g for zinc and 8.38 mg/g of nickel. The experimental data fit in the Langmuir and Freundlich models. The kinetic datas showed a good correlation with the pseudo-second order model. It was conducteas a competition study among the metals using vermiculiti a adsorbent. Results showed that the presence of various metals in solution does not influence their removal at low concentrations, removing approximat wasely 100 % of all metals present in solutions
Resumo:
The manufacture of prostheses for lower limb amputees (transfemural and transtibial) requires the preparation of a cartridge with appropriate and custom fit to the profile of each patient. The traditional process to the patients, mainly in public hospitals in Brazil, begins with the completion of a form where types of equipment, plugins, measures, levels of amputation etc. are identified. Currently, such work is carried out manually using a common metric tape and caliper of wood to take the measures of the stump, featuring a very rudimentary, and with a high degree of uncertainty geometry of the final product. To address this problem, it was necessary to act in two simultaneously and correlated directions. Originally, it was developed an integrated tool for viewing 3D CAD for transfemoral types of prostheses and transtibial called OrtoCAD I. At the same time, it was necessary to design and build a reader Mechanical equipment (sort of three-dimensional scanner simplified) able to obtain, automatically and with accuracy, the geometric information of either of the stump or the healthy leg. The methodology includes the application of concepts of reverse engineering to computationally generate the representation of the stump and/or the reverse image of the healthy member. The materials used in the manufacturing of prostheses nor always obey to a technical scientific criteria, because, if by one way it meets the criteria of resistance, by the other, it brings serious problems mainly due to excess of weight. This causes to the user various disorders due to lack of conformity. That problem was addressed with the creation of a hybrid composite material for the manufacture of cartridges of prostheses. Using the Reader Fitter and OrtoCAD, the new composite material, which aggregates the mechanical properties of strength and rigidity on important parameters such as low weight and low cost, it can be defined in its better way. Besides, it brings a reduction of up steps in the current processes of manufacturing or even the feasibility of using new processes, in the industries, in order to obtain the prostheses. In this sense, the hybridization of the composite with the combination of natural and synthetic fibers can be a viable solution to the challenges offered above
Resumo:
This work presents a algorithmic study of Multicast Packing Problem considering a multiobjective approach. The first step realized was an extensive review about the problem. This review serverd as a reference point for the definition of the multiobjective mathematical model. Then, the instances used in the experimentation process were defined, this instances were created based on the main caracteristics from literature. Since both mathematical model and the instances were definined, then several algoritms were created. The algorithms were based on the classical approaches to multiobjective optimization: NSGA2 (3 versions), SPEA2 (3 versions). In addition, the GRASP procedures were adapted to work with multiples objectives, two vesions were created. These algorithms were composed by three recombination operators(C1, C2 e C3), two operator for build solution, a mutation operator and a local search procedure. Finally, a long experimentation process was performed. This process has three stages: the first consisted of adjusting the parameters; the second was perfomed to indentify the best version for each algorithm. After, the best versions for each algorithm were compared in order to identify the best algorithm among all. The algorithms were evaluated based on quality indicators and Hypervolume Multiplicative Epsilon
Resumo:
The early onset of mental disorders can lead to serious cognitive damage, and timely interventions are needed in order to prevent them. In patients of low socioeconomic status, as is common in Latin America, it can be hard to identify children at risk. Here, we briefly introduce the problem by reviewing the scarce epidemiological data from Latin America regarding the onset of mental disorders, and discussing the difficulties associated with early diagnosis. Then we present computational psychiatry, a new field to which we and other Latin American researchers have contributed methods particularly relevant for the quantitative investigation of psychopathologies manifested during childhood. We focus on new technologies that help to identify mental disease and provide prodromal evaluation, so as to promote early differential diagnosis and intervention. To conclude, we discuss the application of these methods to clinical and educational practice. A comprehensive and quantitative characterization of verbal behavior in children, from hospitals and laboratories to homes and schools, may lead to more effective pedagogical and medical intervention
Resumo:
Heavy metals are used in many industrial processestheirs discard can harm fel effects to the environment, becoming a serious problem. Many methods used for wastewater treatment have been reported in the literature, but many of them have high cost and low efficiency. The adsorption process has been used as effective for the metal remoal ions. This paper presents studies to evaluate the adsorption capacity of vermiculite as adsorbent for the heavy metals removal in a synthetic solution. The mineral vermiculite was characterized by differents techniques: specific surface area analysis by BET method, X-ray diffraction, raiosX fluorescence, spectroscopy in the infraredd region of, laser particle size analysis and specific gravity. The physical characteristics of the material presented was appropriate for the study of adsorption. The adsorption experiments weredriveal finite bath metod in synthetic solutions of copper, nickel, cadmium, lead and zinc. The results showed that the vermiculite has a high potential for adsorption, removing about 100% of ions and with removal capacity values about 85 ppm of metal in solution, 8.09 mg / g for cadmium, 8.39 mg/g for copper, 8.40 mg/g for lead, 8.26 mg/g for zinc and 8.38 mg/g of nickel. The experimental data fit in the Langmuir and Freundlich models. The kinetic datas showed a good correlation with the pseudo-second order model. It was conducteas a competition study among the metals using vermiculiti a adsorbent. Results showed that the presence of various metals in solution does not influence their removal at low concentrations, removing approximat wasely 100 % of all metals present in solutions