Caracterização Microestrutural e Tribocorrosiva de Sistemas Metalocerâmicos Odontológicos do Tipo Ni-Cr/Porcelana E Ni-Cr/Ti/Porcelana

The partial fixed prosthodontics restoration is used to rehabilitate form and function of partial or total compromised teeth, having to remain permanently joined to remainder tooth. The most useful material on prosthodontics is the feldspar porcelain, commercialized as aluminosilicate powders. Dental porcelains are presented with limited mechanical properties to rehabilitate extensive spaces. The association with Ni-Cr metallic systems (metal-ceramic system) allows that the metallic substructure compensates the fragile porcelain nature, preserving the thermal insulation and aesthetics desirable, as well as reducing the possibility of cracking during matication efforts. Cohesive flaws by low mechanical strength connect the metallic substructure to the oral environment, characterized by a electrolytic solution (saliva), by aggressive temperature, pH cyclic changes and mechanical requests. This process results on ionic liberation that could promote allergic or inflammatory responses, and/or clinical degradation of ceramometal system. The aim of this study was to evaluate the presence of an intermediate titanium layer on the microscopic fracture behavior of porcelains on ceramometal systems. Plasma deposition of titanium films result in regular passivating oxide layers which act as barriers to protect the metallic substrate against the hazardous effects of corrosive saliva. Tribocorrosion tests were performed to simulate the oral environment and mechanical stress, making it possible the early detection of crack formation and growth on metal-ceramic systems, which estimate the adherence between the compounds of this system. Plain samples consisting of dental feldspar porcelain deposited either onto metallic substrates or titanium films were fired and characterized by scanning electron microscopy. The result showed that the titanium film improved the adherence of the system compared to conventional metal-ceramic interfaces, thus holding crack propagation

Síntese de catalisadores do tipo LaNixFe1-xO3 como precursores catalíticos para reação oxidação parcial do metano

Nickel-bases catalysts have been used in several reform reactions, such as in the partial oxidation of methane to obtain H2 or syngas (H2 + CO). High levels of conversion are usually obtained using this family of catalysts, however, their deactivation resulting from carbon deposition still remains a challenge. Different approaches have been tested aiming at minimizing this difficulty, including the production of perovskites and related structures using modern synthesis methods capable of producing low cost materials with controlled microstructural characteristics at industrial scale. To establish grounds for comparison, in the present study LaNixFe1-xO3 (x=0, 0.3 or 0.7) perovskites were prepared following the Pechini method and by microwave assisted self-combustion. All samples were sub sequently calcined at 900 °C to obtain the target phase. The resulting ceramic powders were characterized by thermogravimetric analysis, infrared spectroscopy, X ray diffraction, specific area and temperature programmed reduction tests. Calcined samples were also used in the partial oxidation reaction of methane to evaluate the level of conversion, selectivity and carbon deposition. The results showed that the calcined samples were crystalline and the target phase was formed regardless of the synthesis method. According to results obtained by Rietveld refinement, we observed the formation of 70.0% of LaNi0.3Fe0.7O3 and 30.0% of La2O3 for samples LN3F7-900- P, LN3F7-900-M and 41,6% of LaNi0.7Fe0.3O3, 30.7% of La2NiO4 and 27.7% of La2O3 for samples LN7F3-900-P and LN7F3-900-M.Temperature-programmed profiles of the LaNiO3 sample revealed the presence of a peak around 510 °C, whereas the LaFeO3 sample depicted a peak above 1000°C. The highest l evel of methane conversion was obtained for LaNiO3 synthesized by the Pechini method. Overall, catalysts prepared by the Pechini method depicted better conversion levels compared to those produced by microwave assisted self-combustion

Avaliação do desenvolvimento neuropsicomotor em crianças na rede básica de saúde utilizando o teste de Denver II: identificação de fatores de risco materno

Alterations in the neuropsychomotor development of children are not rare and can manifest themselves with varying intensity at different stages of their development. In this context, maternal risk factors may contribute to the appearance of these alterations. A number of studies have reported that neuropsychomotor development diagnosis is not an easy task, especially in the basic public health network. Diagnosis requires effective, low-cost, and easy - to-apply procedures. The Denver Developmental Screening Test, first published in 1967, is currently used in several countries. It has been revised and renamed as the Denver II Test and meets the aforementioned criteria. Accordingly, the aim of this study was to apply the Denver II Test in order to verify the prevalence of suspected neuropsychomotor development delay in children between the ages of 0 and 12 months and correlate it with the following maternal risk factors: family income, schooling, age at pregnancy, drug use during pregnancy, gestational age, gestational problems, type of delivery and the desire to have children. For data collection, performed during the first 6 months of 2004, a clinical assessment was made of 398 children selected by pediatricians and the nursing team of each public health unit. Later, the parents or guardians were asked to complete a structured questionnaire to determine possible risk indicators of neuropsychomotor development delay. Finally the Denver II Developmental Screening Test (DDST) was applied. The data were analyzed together, using Statistical Package for Social Science (SPSS) software, version 6.1. The confidence interval was set at 95%. The Denver II Test yielded normal and questionable results. This suggests compromised neuropsychomotor development in the children examined and deserves further investigation. The correlation of the results with preestablished maternal risk variables (family income, mother s schooling, age at pregnancy, drug use during the pregnancy and gestational age) was strongly significant. The other maternal risk variables (gestational problems, type of delivery and desire to have children) were not significant. Using an adjusted logistic regression model, we obtained the estimate of the greater likelihood of a child having suspected neuropsychomotor development delay: a mother with _75 4 years of schooling, chronological age less than 20 years and a drug user during pregnancy. This study produced two manuscripts, one published in Acta Cirúrgica Brasileira , in which an analysis was performed of children with suspected neuropsychomotor development delay in the city of Natal, Brazil. The other paper (to be published) analyzed the magnitude of the independent variable maternal schooling associated to neuropsychomotor development delay, every 3 months during the first twelve months of life of the children selected.. The results of the present study reinforce the multifactorial characteristic of development and the cumulative effect of maternal risk factors, and show the need for a regional policy that promotes low-cost programs for the community, involving children at risk of neuropsychomotor development delay. Moreover, they suggest the need for better qualified health professionals in terms of monitoring child development. This was an inter- and multidisciplinary study with the integrated participation of doctors, nurses, nursing assistants and professionals from other areas, such as statisticians and information technology professionals, who met all the requirements of the Postgraduate Program in Health Sciences of the Federal University of Rio Grande do Norte

Estudo dos genes do complexo do antígeno leucocitário humano (hla) associados à susceptibilidade ao diabetes mellitus tipo 1

Of all of the genes associated with the development of Diabetes mellitus type 1 (T1D), the largest contribution comes from the genes in the Human Leukocyte Antigen (HLA) region, mostly the class II DR e DQ genes. Specific combinations of alleles DRB1, DQA1 and DQB1 constituting haplotypes, and further, a combination of more than one haplotype, providing multilocus genotypes are associated with susceptibility, protection and neutrality to DM1. Thus, the aim of present study was to verified the association of polymorphisms of HLA genes class II with susceptibility to type 1 diabetes mellitus (T1D). Ninety-two patients with T1D and 100 individuals normoglycemics (NG) aged between 6 and 20 years were studied. Genomic DNA was obtained from peripheral whole blood, collected in EDTA tube, using the extraction kit Illustra Triple Prep®, GE Healthcare. For HLA typing was used DNA LABType system by One Lambda kit applying Luminex® technology to the method of PCRSSO typing reverse. The alleles DRB1*03:01, *04:05, *04:01, *04:02, DQA1*03:01g, *05:01g, DQB1*02:01g, *03:02, the haplotypes DRB1*03:01-DQA1*05:01-DQB1*02:01, DRB1*04:05-DQA1*03:01g-DQB1*03:02, DRB1*04:02-DQA1*03:01g-DQB1*03:02, DRB1*04:01-DQA1*03:01g-DQB1*03:02 and DR3-DQ2/DR4-DQ8 genotype were significantly associated with the chance of developing T1D. The alleles DRB1*11:01, *15:03, *15:01, *13:01, DQA1*01:02, *04:01g, *01:03, DQB1*06:02, *03:01g, *06:03, *04:02, the haplotypes DRB1*11:01-DQA1*05:01-DQB1*03:01, DRB1*13:01-DQA1*01:03-DQB1*06:03 and DRX-DQX/DRX-DQX genotype, formed by other than the DR3-DQ2 or DR4-DQ8 haplotypes, were significantly associated with T1D protection Despite the major racial Brazilian, even at the regional level, these results are similar to the majority of alleles, genotypes and haplotypes of HLA class II-related susceptibility or resistance to T1D, extensively described in the literature for Caucasian population. Children with age at diagnosis less than 5 years of age had significantly higher frequency of the heterozygous genotype DR3-DQ2/DR4-DQ8 compared to children with age at diagnosis than 5 years old. These results also demonstrate strong association of the genetic profile of the class II HLA for this age group, possibly associated with the severity and rapid progression to the onset of T1D. The knowledge of HLA class II genes may be useful in genetic screens that allow the prediction of T1D

Brincadeira do reisado na comunidade Cipó, Pedro II PI: mediação cultural, tradição e modernidade

This research studies the tradition of epiphany in the community of Cipó de Baixo, which belongs to the city of Pedro II, in the state of Piauí. Readings were made seeeking to emphasize the processivity of the play that navigates between permanence and change. The study starts with a social context of the community, in dialogue with the life history of the owner of the epiphany, Raimundo Milú: strong figure who, along with his family networks, as well as networks of patronage and friendship, struggles for the resistence of the play. The description of the ceremony of Kings, with its constituent parts, punctuates the remarkable character of Cipó community epiphany. This detailed understanding of the play favors the understanding of some of the social vines that serve as the basis for the warp of this cultural practice: modernization vine, where we explore the general motivation of Cipó community epiphany transformations - modernity; family and community exchange vine, which describes the scheme that holds the permanence of the play; masculinity vine, explains the strong gender system that crosses Cipó community epiphany; reinvented tradition vine, where we locate the uniqueness of Cipó community epiphany tradition and its dialogues with modern dynamism; conflict between generation vine, depicts the differences between generations and how they contribute to the dialogue between the traditional and the new; theatrical spectacle vine, describes the play as a performative activity. Thus, we build a social scheme that analyzes the play of Kings of Cipó community as a whole, where change and continuity plan a cultural plot on their own

Diagnóstco geoambiental e avaliação de uso e ocupação do campo de dunas da zona especial de interesse turístco II (ZET-II) Natal/RN

The accelerated pressure of use and occupation of Rio Grande do Norte coastline in the last two decades presented the tourism as its main vector, having as a consequence a strong, articulated and growing real estate speculation of this area. In the Natal County there is a Zona Especial de Interesse Turistico II (Special Zone of Tourism Interest II) (ZET-II), consisted of urban beaches with approximately 8.5 km that is an important seashore of the city. The purpose of this research was identification, characterization and assessment of the process of use and occupation of dunes fields emphasizing the role of ZET-II, whereas the specific goals was the analysis of weather, geology and geomorphology, characterization of use and occupation of soil, and elaboration of an environmental diagnosis with identification and description of its mains consequences. The result of this work was the delineation of geologic-geomorphological map of the area with identification of principals units, determining its use and occupation, the measurement of the area already occupied by equipments, besides the description of the environmental impacts on dune fields: devastation, coastline erosion, ocean pollution by sewer and pluvial waters, contamination of groundwater, distribution inadequate of solid residues, landscape degradation, and occupation of seashore through the privatization of public areas. Concluding that the degrading changes occurred in this areas are resulting from the nature of use and urban seashore regulations, which have been diminishing the natural aspect, altering the landscape definitely, compromising the quality of hydro resources and altering its use, privatizing the areas between tides, complicating the population access and obstructing the scenery visualization of dunes and ocean. There is an urgent necessity of improvement of public politics in order to improve the strategies and organization of use and occupation of space urban-coastline

Avaliação da eficiência da remoção de matéria orgânica e microbiológica de três sistemas de lagoas de estabilização em série na Grande Natal-RN: Beira Rio, Jardim Lola I e Jardim Lola II

Waste stabilization ponds are the main technology in use for domestic sewage treatment in Rio Grande do Norte State (RN), northeast Brazil. The are around 80 systems, constructed mainly by municipal city halls, being series comprised by a primary facultative pond followed by two maturation ponds the most used configuration. Due to problems related with the production and destination of sludge and generation of bad odors, the designers have avoided the use of anaerobic lagoons. The majority of systems are rarely monitored to verify their efficiencies and to get new project parameters for future designing. This work has as purpose to make a diagnosis of efficiency of three series of waste stabilization pond series (WSPS) of Jardim Lola 1, Jardim Lola 2 and Beira Rio, located in the North Zone of the city of the Natal/RN, treating domestic raw sewage, on the removal of organic matter and thermotolerant coliform, comparing the operational conditions of the systems this inside of the bands foreseen in the project, through parameters BOD5, QOD, thermotolerant coliforms, dissolved oxygen, pH, temperature, ammoniac nitrogen, total and suspended solids. The work was carried through in the WSPS, all constituted by a primary facultative pond followed by two maturation ponds. Socioeconomic characteristics of population are predominantly low and all the plants are very near of the contributing basins. The series were monitored from of May the November of 2002, totalizing 20 collections of grab samples of raw sewage and ponds effluents between 8:00 and 9:50 h. The main aspect to be detached by the results was the great concentration of organic matter (BOD and COD) and microorganisms the raw sewage which were around two times more concentrated than those values foreseen one in project. Considering all series the highest removals of organic matter were observed in system Beira Rio (84 and 78% of BOD and COD, respectively), which presented high hydraulic detention time (TDH = 89 days). On the other hand, Jardim Lola 1 and Jardim Lola 2 presented a much lower values of HDT (36 days and 18 days respectively) and their removals of BOD and COD were the same (76% and 60%, respectively). The Beira Rio WSPS, was the most efficient verified in relation to solids and ammonia, proving the great influence of the operational variables such as HDT and applied surface organic loadings on the performance of pond series. Although the treatment plants have reached efficiencies of thermotolerant coliforms around 99,999%, the concentrations in the final effluent can be considered very high for launching in aquatic bodies, particularly those produced by Jardim Lola 1 and Jardim Lola 2 series

Em busca de um novo indicador Espectroscópico do período de rotação das Estrelas do tipo solar

The study of sunspots consistently contributed to a better understanding of magnetic phenomena of the Sun, as its activity. It was found with the dynamics of sunspots that the Sun has a rotation period of twenty-seven days around your axis. With the help of Project Sun-As-A-Star that solar spectra obtained for more than thirty years we observed oscillations of both the depth of the spectral line and its equivalent width, and analysis of the return information about the characteristics of solar magnetism. It also aims to find patterns of solar magnetic activity cycle and the average period of rotation of the Sun will indicate the spectral lines that are sensitive to magnetic activity and which are not. Sensitive lines how Ti II 5381.0 Å stands as the best indicator of the solar rotation period and also shows different periods of rotation cycles of minimum and maximum magnetic activity. It is the first time we observe clearly distinct rotation periods in the different cycles. The analysis also shows that Ca II 8542.1 Å and HI 6562.0 Å indicate the cycle of magnetic activity of eleven years. Some spectral lines no indicated connection with solar activity, this result can help us search for programs planets using spectroscopic models. Data analysis was performed using the Lomb-Scargle method that makes the time series analysis for unequally spaced data. Observe different rotation periods in the cycles of magnetic activity accounts for a discussion has been debated for many decades. We verified that spectroscopy can also specify the period of stellar rotation, thus being able to generalize the method to other stars

Estudo clínico-patológico do carcinoma epidermóide de língua e imunoistoquímico das proteínas BMP-2, BMPR-IA, BMPR-II e endoglina

Bone morphogenetic proteins (BMPs) are cytokines involved in proliferation and angiogenesis of many kind of human cancer. The present study analyzed the immunohistochemical expression of BMP-2, BMPR-II, BMPR-IA and endoglin (CD105) and their relationship with the biological behavior and local angiogenesis in tongue oral squamous cells carcinoma (SCC). The sample consisted of 25 cases of tongue SCC without metastasis, 25 tongue SCC with metastasis and 25 cases of Inflamatory Fibrous Hyperplasia (IFH).The histological grade of malignancy proposed by Bryne (1998), adapted by Miranda (2002) was used to classify all tongue SCC cases. Score 0 was attributed to absent-weak immunoexpression and score 1 for strong immunostaning and pattern of distribution was focal or diffuse. Microvessel counts (MVC) was established for CD105. Most of the patients with tongue SCC was male. The principal age in tongue SCC without metastasis was over 65 years and in tongue SCC with metastasis was between 45-65 years. There were predominance of stage II in TNM and in the specimens with high-grade, independent of studied group. For BMP-2, 56% of tongue SCC without metastasis and 72% tongue SCC with metastasis exhibited score 1 while the IFH showed secore 0 in 72% of the cases, with statistical association (p=0,007). Considering the BMPR-II, 52% of tongue SCC without metastasis exhibited score 0; 56% tongue SCC with metastasis and 60% IFH showed score 1. The majority cases of BMPR-IA demonstrated score 1 and 100% of CD105 exhibited strong immunoexpression in tongue SCC. Regarding the pattern distribution, it was noted a tendency to diffuse pattern for the proteins in all groups. The means of MVC were similar in tongue SCC without metastasis (32,91) and in tongue SCC with metastasis (32,05), however existed statistical difference with IFH (p<0,001). There was statistical association of BMP-2 expression with BMPR-II (p=0,008), BMPR-IA (p=0,006) and CD105 (p=0,046). An association between TNM and BMP-2 immunoexpression and their receptors was not detected, nevertheless this association was found with MVC (p=0,047) whose averages were higher for the stages II (35,97) e IV (35,69). No association between histological grading and these proteins was observed. This study suggests that the superexpression of BMP-2 signaling pathways acts on cell proliferation in tongue SCC and can be implicated with more invasive potential. Additionaly, the CD105 is a potent biological marker of neovascularization in this neoplasm and their association with BMP-2 and BMPR-IA receptor, showed that this type of cancer in BMP-2 is presented as pro-angiogenic in the metastatic process

Influência do tipo de abrigo e da frequência de oferta alimentar no comportamento do camarão Macrobrachium rosenbergii (De Man 1879)

Macrobrachium rosenbergii is a freshwater prawn which presents agonistic behavior and heterogeneous growth. It is known that captive conditions can intensify agonism causing injuries and decreased survival, generating a condition of poor welfare. Based on this, we aim to investigate the behavior of M. rosenbergii in the juvenile phase according to different types of shelter and frequencies of feed offer, emphasizing their agonistic behavior. For this, juveniles were observed in the laboratory in three steps. At step I we characterized the behavioral profile; prawns were kept in eight aquariums (27 prawns/m2 ), identified and observed four times along both phases of 24 h light cycle. At step II (2 experiments), we evaluated the use of shelters (brick or polyethylene rolls) and their influence on agonism by the animals. For classification of animals in dominance rank, the method used was David's Score. At step III (3 experiments), we evaluated different frequencies of feed offer on the behavior of individuals, in particular agonism. Results showed that juveniles do not present a pattern activity/inactivity between the phases of the light cycle. We identified a dominance hierarchy among individuals taking advantage of access to food by the dominant, which showed greater weight gain although the frequency of intake did not differ between individuals. The type of shelter influenced the behavior of animals. Brick shelter generated a higher frequency of permanence and a reduction in the frequency of agonistic interactions. The distribution of food more frequently throughout the day, decreased the motivation of animals for food, as well as to fight. Prawns fed four times showed lower frequency of feed intake and agonistic interactions. Thus, we conclude the shelters which reduce animal’s detection by coespecifics and offer the food four times along the day reduce agonistic behavior. This result causes na improvement in life quality of the prawns and also in its quality as final product.

Influência da estratigrafia mecânica no desenvolvimento de falhas distensionais em bacias do tipo Rifte: contribuição da modelagem física

In the last decades, analogue modelling has been used in geology to improve the knowledge of how geological structures are nucleated, how they grow and what are the main important points in such processes. The use of this tool in the oil industry, to help seismic interpretations and mainly to search for structural traps contributed to disseminate the use of this tool in the literature. Nowadays, physical modelling has a large field of applications, since landslide to granite emplacement along shear zones. In this work, we deal with physical modelling to study the influence of mechanical stratifications in the nucleation and development of faults and fractures in a context of orthogonal and conjugated oblique basins. To simulate a mechanical stratigraphy we used different materials, with distinct physical proprieties, such as gypsum powder, glass beads, dry clay and quartz sand. Some experiments were run along with a PIV (Particle Image Velocimetry), an instrument that shows the movement of the particles to each deformation moment. Two series of experiments were studied: i) Series MO: We tested the development of normal faults in a context of an orthogonal (to the extension direction) basin. Experiments were run taking into account the change of materials and strata thickness. Some experiments were done with sintectonic sedimentation. We registered differences in the nucleation and growth of faults in layers with different rheological behavior. The gypsum powder layer behaves in a more competent mode, which generates a great number of high angle fractures. These fractures evolve to faults that exhibit a higher dip than when they cross less competent layers, like the one of quartz sand. This competent layer exhibits faulted blocks arranged in a typical domino-style. Cataclastic breccias developed along the faults affecting the competent layers and showed different evolutional history, depending on the deforming stratigraphic sequence; ii) Series MOS2: Normal faults were analyzed in conjugated sub-basins (oblique to the extension direction) developed in a sequence with and without rheological contrast. In experiments with rheological contrast, two important grabens developed along the faulted margins differing from the subbasins with mechanical stratigraphy. Both experiments developed oblique fault systems and, in the area of sub-basins intersection, faults traces became very curved.

Análise bioclimática do bairro do Renascença II São Luis-MA: realidade e perspectiva do conforto térmico em espaços externos

The present research concerns about outdoor s thermal comfort conditions in hot-humid climate cities, understanding that life quality is a result of the urban object s type built for the human being in an environment with specific climate and morphological characteristics. It is presented as object of study the correlation between the neighborhood Renascença II s microclimate in São Luis /MA-Brazil, hot-humid climate city, and its urban morphological changes. As well as the thermal comfort s satisfaction level of its outdoor users. The research has as general goal to diagnosis the way these transformations caused by the urbanization influence the Renascença II s microclimate, identifying critical spots of the studied area, in order to contribute with land use recommendations based on bioclimatic architecture concepts and supply bases to urban design decisions adequate to the São Luis climate. It is presented as theoretical bases the urban climate, its concepts and elements. After that, the thermal comfort conditioners and its prediction models of thermal comfort sensation in outdoor are presented. The predictive models are presented along with bioclimatic assessment methods. Finally the use of bioclimatic assessment as an effective tool to identify places that need changes or preservation in order to seek environment quality. The applied methodology was based on the studies of Katzschner (1997), complemented by Oliveira s (1988) and Bustos Romero s (2001) studies that suggest an analysis and evaluation of maps of topography, buildings floors, land use, green areas and land covering, in order to overlap their characteristics and identify climate variable s measurements points; then a quantitative analysis of the climate variables (air temperature and humidity, wind speed and direction) of the chosen points takes place. It was perceived that Renaissance II has no permanence areas as squares or parks, its outdoor has little vegetation and presets high land impermeability and built density levels. The majority of the people interviewed said that was comfortable in a range of air temperature between 27,28ºC and 30,71ºC. The elaboration of a neighborhood master plan is important, which defines strategies for improvement of the life quality of its inhabitants

Barracas de Praia, praia de barracas: configuração, tipo e usos na praia do futuro, Fortaleza CE

The purpose of this dissertation is to analyse the importance of the huts of Praia do Futuro to their users and to the city of Fortaleza in Ceará through the comprehension of relations between morphological categories - in urban and edified contexts - of the establishments and their use patterns. This place is one of the main recreation and leisure areas of the city, formed by six kilometres of waterfront, corresponding to a differentiated area through the coast. This space has beach huts with varied profiles: while some more simple huts persist, great complexes are being developed, building even water parks on the beach area. This study analyses relations between:i) spatial configuration (in geometric and mainly topological terms) based on the Social Logic of Space; ii) edified typology (analysing capacity, landscap treatment and program of the huts); and iii) use and environmental perception of the beach by its frequenters. There are consistent relations between the type of hut and their localization in the urban grid, of which were identified groups with different patterns: segregated (north, central and south) and integrated (north: more integrated. and south: less integrated). Such relations also reflect, in varied patterns of use and environmental perception. In spite of their strong economy, the beach huts find themselves in a fragile legal situation because they occupy the beach area, so that this study may come to assist the decision-making for the future of the region. For a sustainable development of the area by those responsible and managers it is necessary to evaluate the cultural importance of the huts at Praia do Futuro, understanding their occupation and uses.

Avaliação de heterociclo do tipo mesoiônico solubilizado em sistema microemulsionado para aplicação em dutos

The efficiency of inhibition to corrosion of steel AISI 1018 of surfactant coconut oil saponified (SCO) and heterocyclic type mesoionics (1,3,4-triazólio-2-tiolato) in systems microemulsionados (SCO-ME and SCO-ME-MI) Of type O/A (rich in water emulsion) region with the work of Winsor IV. The systems microemulsionados (SCO-ME and SCO-ME-MI) were evaluated with a corrosion inhibitor for use in saline 10,000 ppm of chloride enriched with carbon dioxide (CO2). The assessment of corrosion inhibitors were evaluated by the techniques of linear polarization resistance (LPR) and loss of weight (MW) in a cell instrumented given the gravity and electrochemical devices. The systems were shooting speed of less than 60 minutes and efficiency of inhibition [SCO-ME (91.25%) and SCO-ME-MI (98.54%)]

Desenvolvimento de pastas de cimento flexíveis para poços de petróleo submetidos à injeção de vapor utilizando látex do tipo SBR

Novel cementing materials formulations containing flexible polymeric admixtures have been studied aiming at improving the mechanical behavior of oil well cement slurries submitted to steam injection. However, research activities in this sector are still under development. The steam injected directly into the well causes casing dilation, which after a reduction in temperature, tends to return to its original dimensions, resulting in crack formation and hydraulic isolation loss of the well, which will result in shortening of well life. In this scenario, the objective of the present study was to evaluate the mechanical behavior of Portland-based slurries containing SBR latex, applied in oil well cementing of wells submitted to steam injection. Were formulated slurries with densities of 1.797 g/cm3 (15.0 lb/Gal) and 1.869 g/cm3 (15.6 lb/Gal), containing admixtures with a latex concentration of 0; 66.88; 133.76; 200.64 and 267.52 L/m3 (0, 0.5, 1.0, 1.5 and 2.0 gpc). Tests including rheology, fluid loss control, thickening time, API compressive strength and splitting tensile strength, beyond steam injection simulation. Microstrutural characteristics of the slurries were also performed (XRD, TG, FTIR and SEM). The results showed that increasing the polymer concentration increased in the rheological properties and fluid loss, and a decrease in the elasticity modulus of the cement slurries. The results obtained showed that the slurries can be applied in cementing operations of oil wells submitted to steam injection.