Formulação de pastas cimentícias com adição de suspensões de quitosana para cimentação de poços de petróleo

Primary cementing is one of the main operations in well drilling responsible for the mechanical stability and zonal isolation during the production of oil. However, the cement sheath is constantly under mechanical stresses and temperature variations caused by the recovery of heavy oil. In order to minimize fracture and wear of the cement sheath, new admixtures are developed to improve the properties of Portland cement slurries and avoid environmental contamination caused by leaking gas and oil. Polymers with the ability to form polymeric films are candidates to improve the properties of hardened cement slurries, especially their fracture energy. The present study aimed at evaluating the effect of the addition of a chitosan suspension on cement slurries in order to improve the properties of the cement and increase its performance on heavy oil recovery. Chitosan was dissolved in acetic ac id (0.25 M and 2 M) and added to the formulation of the slurries in different concentrations. SEM analyses confirmed the formation of polymeric films in the cementitious matrix. Strength tests showed higher fracture energy compared to slurries without the addition of chitosan. The formation of the polymeric films also reduced the permeability of the slurry. Therefore, chitosan suspensions can be potentially used as cementing admixtures for heavy oil well applications

Evolução diagenética e caracterização dos reservatórios da seção devoniana na Bacia do Rio do Peixe-Nordeste do Brasil

The Rio do Peixe Basin represents a main basin of northeastern Brazil and pioneering work positioned the rocks of this basin in the Early Cretaceous. However, a recent study, based on integrated pollen analysis from three wells, found an unprecedented siliciclastic sedimentary section, in the region, of early Devonian age. Therefore, the present study aims a detailed petrographic and petrological analysis of this devonian section, in the Rio do Peixe Basin and proposes a diagenetic evolution, to understand the characteristics of the porous system, identify the main reservoir petrofacies with the main factors impacting on the quality of these rocks as reservoirs and a quick study on the provenance of this section. The petrographic study was based on samples obtained from subsurface and surface. The diagenetic evolution of petrofacies and its identification were based only on subsurface samples and the study of provenance was based on surface samples. The thin sections were prepared from sandstones, pelites and sandstones intercalated with pelites. The original detrital composition for this section is arcosean and the main diagenetic processes that affected these rocks occur in various depths and different conditions, which resulted in extensive diagenetic variety. The following processes were identified: early fracture and healing of grains; albitization of K-feldspar and plagioclase; siderite; precipitation of silica and feldspar; mechanical infiltration of clay and its transformation to illite/esmectite and illite; autigenesis of analcime; dissolution; autigenesis of chlorite; dolomite/ferrous dolomite/anquerite; apatite; calcite; pyrite; titanium minerals and iron oxide-hidroxide. The occurrence of a recently discovered volcanism, in the Rio do Peixe Basin, may have influenced the diagenetic evolution of this section. Three diagenetic stages affected the Devonian section: eo, meso and telodiagenesis. This section is compositionally quite feldspathic, indicating provenance from continental blocks, between transitional continental and uplift of the basement. From this study, we observed a wide heterogeneity in the role of the studied sandstones as reservoirs. Seven petrofacies were identified, taking into account the main diagenetic constituent responsible for the reduction of porosity. It is possible that the loss of original porosity was influenced by intense diagenesis in these rocks, where the main constituent for the loss of porosity are clays minerals, oxides and carbonate cement (calcite and dolomite)

Nova técnica para obtenção de fraturas com altíssima condutividade em poços de petróleo

Increase hydrocarbons production is the main goal of the oilwell industry worldwide. Hydraulic fracturing is often applied to achieve this goal due to a combination of attractive aspects including easiness and low operational costs associated with fast and highly economical response. Conventional fracturing usually involves high-flowing high-pressure pumping of a viscous fluid responsible for opening the fracture in the hydrocarbon producing rock. The thickness of the fracture should be enough to assure the penetration of the particles of a solid proppant into the rock. The proppant is driven into the target formation by a carrier fluid. After pumping, all fluids are filtered through the faces of the fracture and penetrate the rock. The proppant remains in the fracture holding it open and assuring high hydraulic conductivity. The present study proposes a different approach for hydraulic fracturing. Fractures with infinity conductivity are formed and used to further improve the production of highly permeable formations as well as to produce long fractures in naturally fractured formations. Naturally open fractures with infinite conductivity are usually encountered. They can be observed in rock outcrops and core plugs, or noticed by the total loss of circulation during drilling (even with low density fluids), image profiles, pumping tests (Mini-Frac and Mini Fall Off), and injection tests below fracturing pressure, whose flow is higher than expected for radial Darcian ones. Naturally occurring fractures are kept open by randomly shaped and placed supporting points, able to hold the faces of the fracture separate even under typical closing pressures. The approach presented herein generates infinite conductivity canal held open by artificially created parallel supporting areas positioned both horizontally and vertically. The size of these areas is designed to hold the permeable zones open supported by the impermeable areas. The England & Green equation was used to theoretically prove that the fracture can be held open by such artificially created set of horizontal parallel supporting areas. To assess the benefits of fractures characterized by infinite conductivity, an overall comparison with finite conductivity fractures was carried out using a series of parameters including fracture pressure loss and dimensionless conductivity as a function of flow production, FOI folds of increase, flow production and cumulative production as a function of time, and finally plots of net present value and productivity index

Influência da lubrirrefrigeração na qualidade superficial de metais retificados

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Prevalência de excesso de peso em pré-escolares na cidade do Natal

Obesity is currently considered a public health problem and there has been growing interest in the study of various aspects related to this infirmity such as: epidemiology, diagnosis, treatment, prevention and others. Thus, the purpose of this study was to determine the prevalence of weight excess and overweight in preschoolers in Natal, Brazil and relate them to variables such as gender, age, type of school (public or private) and zones of the city (east/south and north/west). This is a transversal study, carried out in Natal, Brazil between August and September 2004, in 20 public and 20 private schools/day care centers selected by the systematic sampling method. We measured the weight and height of 3721 students between the ages of 2 and 6 years. The children were stratified, according to age, into age group 1 (2 to 4 years) and age group 2 (5 and 6 years) and according to the region of the school, into north/west and east/south zones, the regions with the smallest and highest quality of life indices in the city, respectively. Children were considered to have weight excess when BMI ≥ 85th percentile, including those with BMI ≥ 95th percentile and overweight when BMI ≥ 95th percentile. The prevalence of weight excess was 26.5%, and of overweight 12.4%. There was greater prevalence of weight excess in the private schools and in the east/south zones. Overweight displayed the same epidemiologic profile, with a greater prevalence in private schools and in the east/south zones. The prevalence of weight excess in preschoolers in Natal, Brazil is high and is related, above all, to private schools and to those located in the highest quality of life areas. Therefore, prevention programs should be implanted in elementary schools in order to decrease weight excess and possible associated co-morbidities. This research project met the norms established by PPGCSa/UFRN and aimed at promoting the interrelation between different researchers and between different fields of knowledge, using multi and interdisciplinary concepts. This study was enriched by the interaction between the following professionals: pediatrician, pediatric gastroenterologist and physician nutrition specialist, pediatric endocrinologist, epidemiologist and biostatistician

Os empoderados da agricultura familiar: capital social nos territórios do seridó e do sertão do Apodi/RN

The study of social practices aims to overcome the theoretical dichotomies that insist on separating the individual from the social structures and vice versa. In this sense, the debate between objectivism and subjectivism in the construction of social reality still has occupied much time and reflection of various scholars of the humanities. Pierre Bourdieu has extensive work that seeks to advance in relation to the theoretical framework of traditional sociological explanations. Bourdieu`s approach regarding social practices is considered by some researchers as a synthesis of classical theories and by others as an attempt of complexify contemporary studies on the significance of social life. This thesis sharesthis effort to understand the social practices of agents, aiming to analyze the strategies of social and political leaders of family farming in the territories of Seridó and Apodi in Rio Grande do Norte, and it has as reference the theoretical and methodological concepts of habitus, field and capital, in Bourdieu. Therefore, we studied the trajectories of social leaders, here called agents as family farming in the two locations in Rio Grande do Norte. As techniques and procedures of the study, we resortedto semi-structured interviews, observations, participation in events and other researches. In conclusion, this thesis gives an account of the construction of two different relational fields for the activities of agents of family farming in the territories of Seridó and Apodi. Although the relational fields in the territories have been structured under the same prevailing institutions, which are: church, union and political party, the social practice of agents shows itself from social position and political variety. Even with the similarities and differences identified and analyzed in different fields of construction, the social relations of the agents in the territories result in the construction of gated communities, the social capital that is the substrate which the agents called empowered .

Gesso sintético e pinos transcorticais na redução de fratura de tíbia em uma bezerra

Relata-se um caso de fratura de tíbia em uma bezerra de sete meses de idade, 200kg de peso, apresentando fratura fechada, cominutiva em diáfise. A fixação externa foi preferida como método de imobilização óssea, utilizando-se pinos transcorticais e gesso sintético. Obteve-se eficiente imobilização da fratura, com rápida recuperação do animal, dispendendo-se pouco tempo para o pós-operatório (52 dias). A técnica demonstrou ser de fácil realização e passível de ser executada a campo.

Mens sana in corpore sano: compreensões de corpo, saúde e educação

This thesis proposes that the idea expressed in Juvenal s quotation Mens Sana in Corpore Sano, produced in the Ancient Greek-Roman civilization includes undestandings of body, heath and education that were reapropriated and reorganized by scientific and pedagogical theories in the XIX and XX centuries. These theories, especially the ones that received contributions from the biomedical sciences, have influenced Physical Education in the search of becoming a science. In order to realize this reapropriation, we have analyzed the transformations in the concepts of body, health and education produced in the area discourse, aiming at pointing out elements to the configuration of a theory that is being called Corpore Sano. The theory constitutes in possible systematization of scientific, philosophical and pedagogical concepts, and as such, an understanding of the scientific fundaments of Physical Education. The corpus of this analysis was composed by 148 articles that were published in Revista Brasileira de Ciências do Esporte digitalized in the period between 1979 and 2003 and selected according to theme: body, biology, physical activity, effort physiology and health. The analysis of the content and the referential interpretation allowed the combination of philosophical reflection with attention to the empiric field as a comprehensive dimension. Based on the corpus of the analysis it is possible to configure meta-arguments about the concepts of body, health and education in the scientific production of Physical Education. As a metaresearch. Our study did not intend to judge the analyzed production, but look for theoretical elements that may generate a reflection about the scientific rationality in Physical Education and developments in the pedagogical field and in body practices. Such a reflection might be recognized as a theory of the living body, susceptible to modifications and interrogations that are proper of knowledge and practices of Physical Education. It is a theory rejects the idea of the complete truth and holds the comprehension that the truth is built historically through relations among different kinds of knowledge and Physical Education practices

Representações sociais de formação continuada: com a palavra as professoras do ensino fundamental da rede pública de Natal RN

Metaphorically, research is presented as a journey by sea, having as object of study the social representations of Continuing Education for teachers of elementary school and as aim, to analyze them in comparison of participants from state and municipal systems, located in Natal-RN, Brazil .They have contributed to the achievement of this objective the voices of 158 teachers, the vast literature on training in professional development and the theoretical formulations proposed by Moscovici and colleagues, with relevance to the Central Nucleus Theory advocated by Abric. The corpus resulting from evocations about continuing education, as well as teachers' justifications were submitted to different computer methods/techniques, through the EVOC ALCESTE Programs, respectively, providing the opportunity to highlight a network of interconnections between the likely core and the production of discourse. Although the educational ideologies that underlie social perception of the state teachers are anchored in New School and technicist concepts and the teachers in the city tend to an ideology of social interaction, the choice of working with the symbolic field identified the political-social commitment of groups with the impacts of training on learning of their students

A participação das mães no conselho escolar do CMEI Amor de Mãe

This research aims to study the participation of mothers in the School Council of the Centro Municipal de Educação Infantil Amor de Mãe. The goal is to understand the relationship among concepts that mothers have and their practices as advisors. The historical-philosophical approach taken along the research permitted working with real people and not those derived or idealized ones. It searched an approximation of the mode of being and living of the councilor mothers in their homes, and the concepts and practices in the School Council. It was inspired by ethnographic researches to describe data, habits, cultural practices, meanings and values of people involved. As sources of research, we used: interviews with mothers and school staff; documentary and photographic collection of CMEI Amor de Mãe; local and national legislation; notebooks of the National Program for the Strengthening of School Council (2004); data bank of dissertations and theses of the Post-Graduate Program in Education of the UFRN dealing with democratic management and the relationship school and family. The study indicates the existence of a narrative of the school community that shows mothers as "missing" or "passive" and a practice that point out to how people participate actively in the school routine. This contradiction reveals the existence of a historically constructed school mindset that is rooted in a model of family and school that differs from the reality found in CMEI Amor de Mãe and how families served by CMEI Amor de Mãe organize themselves. It is recommended that the school community and families reorganize the conceptions that guide their practices in educating and caring for children with whom they live and work to make progress together in managing this process

Gestão da satisfação e fidelidade do cliente: um estudo em uma instituição de ensino superior

This Master of Science Thesis deals with the customer satisfaction and loyalty focusing on a private higher education institution in Belém city, Brazil. The literature review focuses on costumer satisfaction and loyalty concepts and theory, models of quality managing systems and methodologies of costumer satisfaction measurement. The research was a survey with a random stratified sample of 329 undergraduate students of Business Administration at the Faculdade do Pará , in the morning and the night periods. The data analysis was made through the descriptive statistics and multiple regression analysis. The main findings are that the model was satisfactory and the main factors affecting Satisfaction to the School were Best Professor Didatics (beta=0.297), Courses Contents (beta=0.280), Clerks Sympathy (beta=0.201), and Number of Students in Classroom (beta=0,187) with a adjusted R2 = 0,47. The main factors affecting School Loyalty with an adjusted R2 = 0,43 were School Image (beta=0.383), Affective Commitment (beta=0.255), and Satisfaction with Professors (beta=0,218). The findings suggest also that may be differences between the set of students and those that complain for something

Utilização de subprodutos de origem animal em dietas para frangos de corte com base no conceito de proteínas bruta e ideal, no período de 43 a 49 dias de idade

Foi conduzido um experimento para avaliar a utilização de subprodutos de origem animal em rações para frangos de corte, formuladas com base nas proteínas bruta e ideal no período de 43 a 49 dias de idade. Foram utilizados 600 frangos machos distribuídos em arranjo fatorial 2x2+1, com duas fontes de proteína de origem animal (farinha de vísceras de aves e farinha de sangue bovino), dois conceitos de formulação (proteínas bruta e ideal) e uma ração testemunha à base de milho e de farelo de soja, com quatro repetições cada. As características avaliadas foram ganho de peso, consumo de ração, conversão alimentar, rendimento de carcaça, peito e porcentagem de gordura abdominal. Os melhores ganho em peso e conversão alimentar foram obtidos quando a dieta à base de milho e farelo de soja foi utilizada. As farinhas de vísceras e de sangue e os conceitos de formulação não exerceram influência sobre as características avaliadas.

Utilização de subprodutos de origem animal em dietas formuladas com base em proteína bruta e proteína ideal para frangos de corte de 22 a 42 dias de idade

Foi conduzido um experimento para avaliar a utilização de subprodutos de origem animal em dietas para frangos de corte de 22 a 42 dias de idade, formuladas com base nos conceitos de proteína bruta e proteína ideal. O delineamento foi inteiramente casualizado em esquema fatorial 2x2+1, ou seja, duas fontes de proteína de origem animal (farinha de vísceras de aves e farinha de sangue bovino), dois conceitos de formulação (proteína bruta e proteína ideal) e uma dieta controle à base de milho e farelo de soja, com quatro repetições. As características avaliadas foram ganho de peso, consumo de ração, conversão alimentar, rendimentos de carcaça e de peito e gordura abdominal. O ganho de peso, consumo de ração e conversão alimentar não foram afetados pelas fontes de proteína e conceitos de formulação, no entanto, o teor de gordura abdominal foi menor nas aves alimentadas com farinha de vísceras que naquelas alimentadas com dieta contendo farinha de sangue.

Aplicação de sistemas multi-classificadores no diagnóstico de falhas em motores de indução trifásicos

Equipment maintenance is the major cost factor in industrial plants, it is very important the development of fault predict techniques. Three-phase induction motors are key electrical equipments used in industrial applications mainly because presents low cost and large robustness, however, it isn t protected from other fault types such as shorted winding and broken bars. Several acquisition ways, processing and signal analysis are applied to improve its diagnosis. More efficient techniques use current sensors and its signature analysis. In this dissertation, starting of these sensors, it is to make signal analysis through Park s vector that provides a good visualization capability. Faults data acquisition is an arduous task; in this way, it is developed a methodology for data base construction. Park s transformer is applied into stationary reference for machine modeling of the machine s differential equations solution. Faults detection needs a detailed analysis of variables and its influences that becomes the diagnosis more complex. The tasks of pattern recognition allow that systems are automatically generated, based in patterns and data concepts, in the majority cases undetectable for specialists, helping decision tasks. Classifiers algorithms with diverse learning paradigms: k-Neighborhood, Neural Networks, Decision Trees and Naïves Bayes are used to patterns recognition of machines faults. Multi-classifier systems are used to improve classification errors. It inspected the algorithms homogeneous: Bagging and Boosting and heterogeneous: Vote, Stacking and Stacking C. Results present the effectiveness of constructed model to faults modeling, such as the possibility of using multi-classifiers algorithm on faults classification

Envelhecimento ambiental acelerado em PRF a base de tecidos híbridos kevlar/vidro: propriedades e instabilidade estrutural

There are a number of damaging mechanisms that various materials can suffer in service. However, when working with polymer composite materials, this is something that requires analysis, especially when exposed to adverse environmental conditions. Thus, the objective of the present thesis is the study of the direct influence of environmental aging and the form of hybridization of the reinforcement woven on the structural stability, surfacedegradation and fracture process of polymer composites laminates. For this, the development of two polymer composite laminates was necessary, where one of them was reinforced with a bi-directional woven with hybrid strandsofkevlar-49/glass-Efibers, and the other also with a bi-directionalwoven, however with weft and warpformed of alternating strandsof Kevlar-49 fibers and glass-E fiber The reinforcementwoven are industrially manufactured. Both laminates use a polyester resin as a matrixand are made up of four layers each. All laminates were industrially prepared by the hand lay-up method of manufacturing. To do this, test specimens were manufactured of the respective laminates and submitted to environmental aging accelerated through the aging chamber. They were exposed to alternating cycles of UV radiation and moisture (heated steam) for a standard defined period. At the end of the exposure period the specimens were subjected to mechanical tests of uniaxial tensile and bending in three points and to the characterizationsof the fracture and surface deterioration. In addition, they were submitted to a structural degradation assessment by the measurement of mass variation technique (MMVT) and the measurement of thickness variation technique (MTVT), this last technique being developed in this thesis. At the end of the analysis it was observed that the form of hybridization of the reinforcement woven and the aging process directly influence with losses or gain in mechanical properties, with losses in the structural degradation and in the formation and propagation of damage mechanism of the developedcomposite laminates