Pastas compósitas cimento/sílica/polímero para cimentação de poços de baixa profundidade sujeitas à injeção de vapor

The production of heavy oil fields, typical in the Northeastern region, is commonly stimulated by steam injection. High bottom hole temperatures are responsible not only for the development of deleterious stresses of the cement sheath but also for cement strength retrogression. To overcome this unfavorable scenario, polymeric admixtures can be added to cement slurries to improve its fracture energy and silica flour to prevent strength retrogression. Therefore, the objective of the present study was to investigate the effect of the addition of different concentrations of polyurethane (5-25%) to cement slurries containing 40% BWOC silica flour. The resulting slurries were characterized using standard API (American Petroleum Institute) laboratory tests. In addition to them, the mechanical properties of the slurries, including elastic modulus and microhardness were also evaluated. The results revealed that density, free water and stability of the composite cement/silica/polyurethane slurries were within acceptable limits. The rheological behavior of the slurries, including plastic viscosity, yield strength and gel strength increased with the addition of 10% BWOC polyurethane. The presence of polyurethane reduced the fluid loss of the slurries as well as their elastic modulus. Composite slurries also depicted longer setting times due to the presence of the polymer. As expected, both the mechanical strength and microhardness of the slurries decreased with the addition of polyurethane. However, at high bottom hole temperatures, the strength of the slurries containing silica and polyurethane was far superior than that of plain cement slurries. In summary, the use of polyurethane combined with silica is an interesting solution to better adequate the mechanical behavior of cement slurries to heavy oil fields subjected to steam injection

Estudo da formulação de pré-misturas secas para a cimentação de poços em terra

An economical solution for cementing oil wells is the use of pre-prepared dry mixtures containing cement and additives. The mixtures may be formulated, prepared and transported to the well where is added water to be pumped.Using this method, becomes dispensable to prepare the cement mixes containing additives in the cementing operation, reducing the possibility of error. In this way, the aim of this work is to study formulations of cement slurries containing solid additives for primary cementing of oil wells onshore for typical depths of 400, 800 and 1,200 meters. The formulations are comprised of Special Class Portland cement, mineral additions and solids chemical additives.The formulated mixtures have density of 1.67 g / cm ³ (14.0 lb / gal). Their optimization were made through the analysis of the rheological parameters, fluid loss results, free water, thickening time, stability test and mechanical properties.The results showed that mixtures are in conformity the specifications for cementing oil wells onshore studied depths

Efeito da adição de microfibras de lã de vidro na tenacidade à ruptura de pastas de cimento para poços de petróleo

Although there are a wide variety of additives that act in fresh state, to adjust the properties of cement, there is also a search by additions that improve the tenacity of the cement in the hardened state. This, in turn, can often be increased by inserting fibers, which act on the deflection of microcracks. This study aimed to use a microfiber glass wool (silica-based) as an additive reinforcing the cement matrix, improving the rupture tenacity, in order to prevent the propagation of microcracks in the cement sheath commonly found in oil wells submitted to high temperatures. The fibers were added at different concentrations, 2 to 5% (BWOC) and varied average sizes, grinding for 90 s, 180 s, 300 s, 600 s. The cement slurries were made with a density of 1,90 g/ cm3 (15,6 lb/gal), using Portland cement CPP- Special Class as the hydraulic binder and 40% silica flour. The characterization of the fiber was made by scanning electron microscopy (SEM), particle size by sieving, X-ray fluorescence (XRF), X-ray diffraction (XRD) and thermogravimetry (TG / DTG). Were performed technological tests set by the API (American Petroleum Institute) by rheology, stability, free water, compressive strength, as well as testing rupture energy, elastic modulus and permeability. The characterization results showed good thermal stability of the microfiber glass wool for application in oil wells submitted to steam injection and, also, that from the particle size data, it was possible to suggest that microfibers milled up to 300 s, are ideal to act as reinforcement to the cement slurries. The rheological parameters, there was committal of plastic viscosity when larger lengths were inserted of microfiber (F90). The values obtained by free water and stability were presented according to API. The mechanical properties, the incorporation of microfiber to the cement slurries gave better rupture tenacity, as compared to reference cement slurries. The values of compressive strength, elastic modulus and permeability have been maintained with respect to the reference cement slurries. Thus, cement slurries reinforced with microfiber glass wool can ensure good application for cementing oil wells submitted to steam injection, which requires control of microcracks, due to the thermal gradients

Efeito da adição de cargas minerais leves na resistência mecânica de grautes para cimentação de poços offshore

The preparation of cement slurries for offshore well cementing involves mixing all solid components to be added to the mixing water on the platform. The aim of this work was to study the formulation of pre-prepared dry mixtures, or grouts, for offshore oilwell cementing. The addition of mineral fillers in the strength of lightweight grouts applied for depths down to 400 m under water depths of 500 m was investigated. Lightweight materials and fine aggregates were selected. For the choice of starting materials, a study of the pozzolanic activity of low-cost fillers such as porcelain tile residue, microsilica and diatomaceous earth was carried out by X-ray diffraction and mechanical strength tests. Hardened grouts containing porcelain tile residue and microsilica depicted high strength at early ages. Based on such preliminary investigation, a study of the mechanical strength of grouts with density 1.74 g/cm3 (14.5 lb/gal) cured initially at 27 °C was performed using cement, microsilica, porcelain tile residue and an anti-foaming agent. The results showed that the mixture containing 7% of porcelain tile residue and 7% of microsilica was the one with the highest compressive strength after curing for 24 hours. This composition was chosen to be studied and adapted for offshore conditions based on testes performed at 4 °C. The grout containing cement, 7% of porcelain tile residue, 7% of active silica and admixtures (CaCl2), anti-foaming and dispersant resulted satisfactory rheology and mechanical strength after curing for 24 hours of curing

Description of a new species of skate of the genus Malacoraja Stehmann, 1970: the first species from the southwestern Atlantic Ocean, with notes on generic monophyly and composition (Chondrichthyes: Rajidae)

O primeiro registro para o Atlântico Sul ocidental de uma espécie do gênero Malacoraja Stehmann, 1970 é feita com base na descrição de Malacoraja obscura, espécie nova, proveniente do talude continental do Sudeste brasileiro dos estados do Espírito Santo e Rio de Janeiro em profundidades de 808-1105 m. A espécie nova é conhecida através de cinco exemplares e é distinta de seus congêneres pela sua coloração dorsal composta por numerosas manchas esbranquiçadas e pequenas na região do disco e nadadeiras pélvicas, por apresentar uma fileira irregular de espinhos ao longo da superfície dorsal mediana da cauda a qual persiste em espécimes maiores (desde a base da cauda até dois-terços do seu comprimento numa fêmea de 680 mm de comprimento total, CT) e uma região pequena desprovida de dentículos na base ventral da cauda (estendendo somente até a margem distal da nadadeira pélvica). Outros caracteres diagnósticos em combinação incluem a ausência de espinhos escapulares em indivíduos maiores, número elevado de fileiras dentárias (64/62 fileiras num macho subadulto de 505 mm de CT e 76/74 numa fêmea de 680 mm de CT) e de vértebras (27-28 Vtr, 68-75 Vprd), coloração ventral do disco uniformemente castanha escura, duas fenestras pós-ventrais na cintura escapular, fenestra pós-ventral posterior grande, forame magno circular e dois forames para a carótida interna na placa basal ventral do neurocrânio. Machos adultos não são conhecidos, porém uma descrição anatômica de M. obscura, sp. nov., é fornecida. Comparações são realizadas com todo o material conhecido de M. kreffti, com a literatura sobre M. senta e com material abundante de M. spinacidermis da África do Sul; M. obscura, sp. nov., assemelha-se mais a M. spinacidermis do Atlântico Sul oriental em esqueleto dérmico, coloração e tamanho. Malacoraja é monofilético devido à sua espinulação e apêndices rostrais conspícuos e é aparentemente composta por dois grupos de espécies, um para M. obscura e M. spinacidermis e outro para M. kreffti e M. senta, porém a elucidação das relações filogenéticas entre as espécies necessita de mais informações anatômicas, principalmente das duas últimas espécies.

Construção e validação de instrumento simplificado para diagnóstico de disfunção temporomandibular em pacientes adultos

As disfunções temporomandibulares (DTM) representam a maior causa de dor não dentária da região orofacial. Dada sua alta prevalência na população em geral e a existência de inúmeros instrumentos diagnósticos não padronizados, buscou-se elaborar e validar um questionário simples, de acessibilidade ampla e aplicação prática, com vistas a contribuir para o diagnóstico e o estudo epidemiológico das mesmas. A estratégia utilizada na montagem do instrumento foi estabelecida com base na avaliação criteriosa de questionários já existentes na literatura, validação de expertos na área de DTM, validação fatorial, de face (na primeira fase do estudo) e, frente ao padrão ouro (RDC/TMD), na segunda fase do estudo. Na primeira fase, participaram 160 indivíduos. A consistência interna resultou num Coeficiente Alfa de Cronbach de 0,752 para o questionário com sete itens; enquanto que para o questionário com cinco itens, este resultado foi de 0,694, não sendo o mesmo, considerado baixo por avaliar apenas cinco questões e ainda, em razão do tema central da pesquisa ser bastante subjetivo. A análise fatorial confirmatória apontou para uma variância total dos fatores extraídos do questionário com sete itens, de 58,2 % e do questionário com cinco itens de 70,04%. Portanto, o questionário com cinco questões, apresentou resultados estatísticos superiores ao de sete questões. Na validação frente ao padrão ouro (RDC/TMD), foram avaliados 99 indivíduos tendo sido testados os dois questionários, com sete e com cinco questões. Na estrutura com sete questões, ao se categorizar as mesmas por totais de pontos obtidos, em quatro condições, obteve-se o melhor resultado quando se considerou com DTM a faixa entre 10 e 21 pontos, sendo 85,1% positivos também no RDC/TMD, com acurácia de 90,1% e Kappa 0,817. Nesta condição, a sensibilidade encontrada foi de 95% (IC 95%, 91 a 99), especificidade de 87% (IC 95%, 81 a 93), VPP 85%, VPN 96%, LR+ 7,3 e LR- 17,4. Quando os dados foram avaliados para o questionário com cinco questões (QST/DTM), pode-se observar que o melhor ponto de corte foi quando se considerou como portadores de DTM, os indivíduos na faixa entre 7 e 15 pontos, com acurácia de 85,8% e Kappa 0,817. Nesta condição, a sensibilidade foi 88% (IC 95%, 81,6 a 94,4), especificidade 84% (IC 95%, 76,8 a 91,2), VPP 80%, VPN 90,5%, LR+ 5,5 e LR- 7,0. A simplicidade do presente questionário (QST/DTM) com apenas cinco questões, possibilita seu uso como elemento de triagem inicial na área da dor orofacial em disfunção temporomandibular, com boa compreensibilidade, confiabilidade, reprodutibilidade e possibilidade de aplicação em pesquisas epidemiológicas. Concluiu-se que o questionário aqui validado, permite sua aplicação de forma simples tanto por profissionais e pesquisadores da Odontologia como de outras áreas da saúde

Um olhar sociológico sobre a criança e o brincar: espaço e tempo de construção, reinvenção e aprendizagem

This research I discuss the play, also talking with the other subjects that make up the universe in which the play is inserted, such as family, school and culture. The fundamental proposition of this dissertation assumes that the absence of play in children's lives affect their physical structure, psychological, biological, cultural, social, historical and theirs development. The initial questions were: What are the spacetimes reserved in the school for play? What is the importance of play in the development of children? Does the school recognize the importance of play in its social space? How the children perceive and use the spacetimes to play at school? Are there spacetimes at school to play? This is a theoretical and empirical research of exploratory study. The research‟s field was the Municipal School Professor Ulysses Góes, located in district of Nova Descoberta, in Natal, Rio Grande do Norte and, as research techniques, I used: participant observation, photography, structured interviews with students and questionnaires with teachers. The results indicate that for most of children, the school allows the play, few disagree with this preposition.Teachers recognize the importance of play in school, but for various reasons do not provide your practice. The dissertation points the possibility of new studies and developments for the theme.

Plano de Desenvolvimento da Escola (PDE): o processo de implantação de uma nova proposta de descentralização em duas escolas da rede municipal de ensino de Natal de 1999 a 2002

The 1988 Constitution was the legal marc to define changes in Brazilian State with major importance to the layout of public politician. In that moment of redefinitions e openness to new ways the redemocratization, participation and decentralization of public school had as their starter the elementary school. This work focus on the manage of FUNDESCOLA, particularly one of its politics called PDE (Educational Development Plan) wich purpose is guarantee a better quality in teaching and spread out democracy throughout its methodology. It was chosen two public schools: Professor Ulisses de Góis and Antonio Campos. The theoretical and methodological orientation is based on the theory of participative democracy developed by authors such as Putnam and Pateman. They says that a cultural background precedes individual participation in society. The collected data (educational legislation, surveys with all sectors of schools and technicians of Natal educational secretary, and relevant documents of de institutions) showed that PDE. Implementation had opposite runnings in the schools studied. In one, as a consequence of bad preparations of its teachers to absorve its methodology, PDE failed. In another way, PDE achieved its goals, especially helping the structure of action plans of the school and the administrative organization making possible several pedagogic activities planned. The work concludes that the main factor the failure or success of PDE relies on the organizational (both political and pedagogical) structure of each school. This discovery implies three important guidelines when comes to formulation of public politicians: a) Constitution of school; b) the local actors who manages the actions; c) the colletive interest in taking part of decisions

Brincar, atividade humana e ferramenta pedagógica no contexto escolar da região metropolitana de natal

This thesis talks about the use of guided educational tools in play and playful in public schools in the Metropolitan Region of Natal (MRN), contributing to the teaching and students learning of basic education in the contents of portuguese and mathematics. We assume that the play is an activity / human need and therefore implies the proper development of children in physical, psychological, biological, cultural, social and historical aspects. We consider the mediation exercised by the teacher in the classroom, and the affection existing between teacher and student, sine qua non terms, so that the truth and fact of the process of teaching and learning occur. Thus, theoretically collaborated Paulo Freire, with his dialogical vision; Lev S. Vygotsky says that we learn and why we develop; Lev S. Vygotsky that states that we learn and for that we develop ourselves; Pierre Bourdieu and the concept of habitus, as something embedded and therefore procedural, and the cultural capital that needs to be fed and (re)meaning at school; Luiz Pereira, Bernard Lahire, Gilles Brougère and others brought their theoretical contributions. The empirical field of research was composed by the Municipal School Professor Ulysses de Góis, located in the neighborhood of Nova Descoberta in Natal, and the Municipal School José Horacio de Góis, located in the community of Guanduba, in São Gonçalo do Amarante, municipalities of the Metropolitan Region of Natal (MRN). We used as methodology the collaborative-action-research as a possible of effective participation of the research subjects, imputing them a voice and performance in the process, and not considering them just observers. The results indicate the effectiveness of the pedagogical tools in play and playful to the learning of students, but that alone is not able to solve all the problems of the school, other referrals need to be secured, as the planning of the actions to be developed in the school and in the classroom, systematized pedagogical orienttion for faculty, family participation/involvement in the school life of students, among other actions that need to be weighted so that education fulfills its role and promote the emancipation of the subject, because in the freireana liberating perspective, "the reading of the world preced the lecture of the word"

A sistematização do conteúdo jogo nas aulas de educação física do ensino fundamental e médio

Since the enactment of LDBEN 9.9394/96, Physical Education began to be understood as a curricular component in school. Thus, we see the need for systematization of content. We observed that the physical education classes at the public schools in Natal/RN from the game content, teachers did not use the existing proposals for systematization. And it was on this reality that the study occurred, aiming to present and discuss a proposal to systematization the game content in physical education classes in elementary and secondary education. Accordingly, we departed of following question: What possibilities of systematization of the game content in school physical education classes?. The methodology used was the action research, which allowed us to structure the intervention plan for the game content, directed to a reflective didactic process. The dialogue with action research provided an opportunity to understand of the proposal of systematization, the knowledge of game content, the planning and process of teaching and learning in physical education lessons developed. We use the proposed systematization the book Educação Física Escolar e Organização Curricular , to direct and organize the lesson plans. As research technique, we use the participant observation, filming, photographic records and field diary, guiding us in the debates and discussions about the field of research. The applications of the lesson plans were carried out in three schools, all located in Natal / RN: Escola Municipal Professora Ivonete Maciel, Escola Municipal Professor Ulisses de Góis e Professor Escola Estadual Josino Macedo. The members of this study were students PIBID-EF-UFRN, teachers, supervisors and school. They made the bridge between research and action, theoretical foundation and pedagogical practice, university and school. The results were advanced for beyond the propositions submitted by the above-mentioned book. For the Elementary School 1, the proposed systematization broadened experiences and learning of knowledge of the game and of playful and body manifestations. Provided an opportunity to know and learn about game of make account, rules, popular games, cooperative games, among others. For Elementary Schools 2 and Middle education, systematized lessons allowed the practical, the incorporation of knowledge of the game and its features: such as rules, origin, meaning of the name, different denominations, among others. The students experienced and learned, popular games, pre-sport games, cooperative games, with recycled material, among others. The treatment from three dimensions of contents: procedural, conceptual and attitudinal, occurred parallel to approach the game content, and in conjunction with our interventions, not being done separately during practice, but an ongoing process during class. This new perspective of work the game, in a systematized way, with applying, description and discussion the activities, allowed elaborate a summary framework of thematizations for game content, by year of teaching

Sistema de gestão ambiental na produção de água mineral

It s more and more evident the subject of the shortage of water, worsened by the accelerated urbanization, growth of the population, increase of the demand and of the costs of its treatment, factors that are also tied up to the increase of the consumption of mineral waters, whose chemical composition or physical-chemistries characteristics do with that are considered beneficial to the health. The growth accelerated all over the world in its consumption aims the concern with the waters quality, the health and the incentive to the consumption of natural products. However, in spite of quite valuable, that resource is explored, most of the time, without optimization of production or actions that avoid wastefulness. This research is justified for the need of minimizing the negative environmental impacts caused by the mineral water s production, mainly in what it say about the generation of effluents and wastes in the productive process, through the study, development and application of cleaner production tools for the environmental management, pertinent for that section. The applicability of Environmental Management System was determined by means of the characterization of the environmental aspects of productive process in a company of the section, in the state of Rio Grande do Norte and of the discussion of the panoramas that demonstrate the tendency for a sustainable development. Actions as a reforestation, optimization of energy and water uses, recycle of solid residues and water reuse were applied during the research, resulting in the considerable reduction of wastes of raw materials and inputs and consequent environmental and economic won. A specific methodology was proposed with concepts of Environmental Management, integrating with Quality Management. As foundations for the elaboration of the methodology, it was realized a similarity analysis among the systems and, mainly, an analysis of the experiences observed in the case study, including specificities, needs and difficulties of the company. With these results, the implantation of a EMS as a company strategy has environmental, economic and social benefits, and this research can be applied and adequate to others companies and sectors

Performance evaluation on electronic control systemsfor field sprayers using programmable logic controllers

The aim of this study was to develop a laboratory method for time response evaluation on electronically controlled spray equipment using Programmable Logic Controllers (PLCs). For that purpose, a PLC controlled digital drive inverter was set up to drive an asynchronous electric motor linked to a centrifugal pump on a experimental sprayer equipped with electronic flow control. The PLC was operated via RS232 serial communication from a PC computer. A user program was written to control de motor by adjusting the following system variables, all related to the motor speed: time stopped; ramp up and ramp down times, time running at a given constant speed and ramp down time to stop the motor. This set up was used in conjunction with a data acquisition system to perform laboratory tests with an electronically controlled sprayer. Time response for pressure stabilization was measured while changing the pump speed by +/-20%. The results showed that for a 0.2 s ramp time increasing the motor speed, as an example, an AgLogix Flow Control system (Midwest Technologies Inc.) took 22 s in average to readjust the pressure. When decreasing the motor speed, this time response was down to 8 s. General results also showed that this kind of methodology could make easier the definition of standards for tests on electronically controlled application equipment.

Periodic inspection on crop sprayers: Results according to age of sprayers

The objectives of the IPP Project-Periodic Inspection on Crop Sprayers-are to develop methods for sprayer certification, analyze quality on spray operation, propose an inspection system for crop sprayers in Brazil, improve environmental quality on spray operation, and reduce costs on chemical control for plant protection systems. Periodic inspections on crop sprayers are performed in several countries and are compulsory in most of them, and it is becoming an important tool for improvement and optimization of use of chemicals. The IPP Project in Brazil is funded by FAPESP-Fundação de Amparo a Pesquisa do Estado de São Paulo. The results so far showed that all the sprayers presented failures. However, most of them could be approved with minor services. As an example, 56.6% of the sprayers with more than 2 years of use presented leaks, 47% of them had damaged hoses and 80.5% presented bad tips (nozzles). These results indicate the need for better procedures of use and maintenance of sprayers, justifying the periodic inspection system.

Influência de pontas de pulverização e adjuvantes na deriva em caldas com glyphosate

O uso inadequado da tecnologia de aplicação de agrotóxicos, relacionados ao uso de pontas de pulverização e adição de adjuvantes, resulta diretamente em um maior risco de deriva. Objetivou-se como trabalho quantificar a deriva gerada por pontas de pulverização com e sem indução de ar, em aplicações de glyphosate e adjuvantes. O experimento foi realizado em túnel de vento, com o herbicida glyphosate isolado ou em mistura com ureia ou adjuvante redutor de deriva (LI700). As coletas foram realizadas, com fios de polietileno, nas distâncias de 5,0; 10,0 e 15,0 m em relação à barra e nas alturas de 0,2; 0,4; 0,6; 0,8 e 1,0 m em relação ao piso do túnel, a deriva foi aferida por meio do processo de condutividade elétrica. Os resultados apresentaram maior deriva nas menores alturas, tendo igual comportamento para todas as caldas e em todas as distâncias. A ponta de jato plano com indução de ar (AVI 110-015) proporcionou menor deriva em relação à ponta jato plano padrão (AXI 110-015), para todas as caldas avaliadas. Para a ponta de jato plano padrão o acréscimo de adjuvante reduziu a deriva para as três distâncias avaliadas em relação à calda contendo somente o herbicida. Já para a ponta de jato plano com indução de ar a ureia elevou a deriva para todas as distâncias em relação às outras caldas. A ureia pode ser utilizada em aplicações com o modelo de ponta jato plano padrão, por diminuir os riscos de deriva.

Viabilidade econômica dos sistemas manual e mecanizado de aplicação de herbicidas em ferrovias

A aplicação mecanizada de herbicidas em ferrovias tem como principal vantagem a grande capacidade operacional, cobrindo trechos extensos em curtos espaços de tempo. Entretanto em função das características dos equipamentos utilizados, quase sempre ocorre grande desperdício de herbicida. A aplicação manual, através de pulverizadores costais, tem como principal vantagem a possibilidade da pulverização dirigida às áreas infestadas, diminuindo a quantidade de herbicida aplicado. Por outro lado, sua reduzida capacidade operacional faz com que a aplicação de longos trechos seja demorada, tornando-a, assim, mais dependente dos problemas climáticos e operacionais da ferrovia. O objetivo do trabalho foi realizar uma análise comparativa das características operacionais e econômicas destes sistemas de aplicação, apontando os fatores mais importantes a serem avaliados para a sua implantação. Para tanto, foram realizadas simulações em computador, baseando-se em diversas equações matemáticas e dados levantados no campo. Os resultados mostraram que a aplicação manual apresentou-se mais econômica apenas para trechos com baixas infestações (até 10%, e média). Na composição de custos, os gastos com herbicidas corresponderam a cerca de 80% do total para a aplicação mecanizada e apenas 8% na manual. Levando-se em conta os fatores operacionais e de mão-de-obra, em apenas um dos trechos avaliados houve vantagem econômica do uso da aplicação manual.