Estudo paramétrico da injeção de polímeros em reservatórios de petróleo

Developing an efficient methodology for oil recovery is extremely important . Within the range of enh anced oil recovery, known as EOR, the injection of polymer solutions becomes effective in controlling the mobility of displacing fluid . This method consists of adding polymers to the injection water to increase its viscosity, so that more water diffuses in to the porous medium and increasing the sweep efficiency in the reservoir. This work is studied by numerical simulation , application of the injection polymer solution in a homogeneous reservoir , semisynthetic with similar characteristics to the reservoirs of the Brazilian Northeast , numerical simulations were performed using thermal simulator STARS from CMG (Computer Modelling Group ). The study aimed to analyze the influence of some parameters on the behavior of reservoir oil production, with the response to cumulative production. Simulations were performed to analyze the influence of water injection, polymer solution and alternating injection of water banks and polymer solution, comparing the results for each simulated condition. The primary outcomes were: oil viscosity, percentage of injected polymer, polymer viscosity and flow rate of water injection. The evaluation of the influence of variables consisted of a complete experimental design followed a Pareto analysis for the purpose of pointing out which va riables would be most influential on the response represented b y the cumulative oil production . It was found that all variables significantly influenced the recovery of oil and the injection of polymer solution on an ongoing basis is more efficient for the cumulative production compared to oil recovery by continuous water injection. The primary recovery show ed low levels of oil production , water injection significantly improves the pro duction of oil in the reservoir , but the injection of polymer solution em erges as a new methodology to increase the production of oil, increasing the life of the well and possible reduction of water produced.

Fluidos de perfuração aquosos: a contribuição da goma xantana e carboximetilcelulose no controle de filtrado

This study aimed mainly to evaluate the influence of xanthan gum (XG) and carboxymethylcellulose (CMC) in the filtration process of water-based drilling fluids, considering the conformational changes suffered by the polyelectrolyte with the addition of sodium chloride (NaCl) in different concentrations (0.17, 0.34 and 0.51 mol.L-1). It was also evaluated the behavior of the fluid by the addition of calcium carbonate (CaCO3) in pure water and in brine. Seeking a better understanding of the interaction between the polymers used and CaCO3, polymer adsorption analyzes were performed using a depletion method, which yielded a higher percentage of adsorption of Xanthan Gum in this material (29%), which can justify the formation of a thin and waterproof filter cake for drilling fluids containing this polymer. However, the best values of apparent viscosity (20 and 24 mPa.s) and volume of filtrate (8.0 and 8.1 mL) were obtained for the systems consisting of xanthan gum, CMC and CaCO3, in NaCl aqueous solutions concentrations of 0.34 and 0.51 mol.L-1, respectively. The values can be related to the presence of CMC that increases the apparent viscosity and reduces the volume of filtrate. In addition, the CaCO3 added acts as a bridging agent, promoting the formation of a less permeable filter cake

Ser cuidador de paciente com acidente vascular cerebral: histórias não contadas

The present study aimed to understand the experience of being a family caregiver of a patient with Cerebrovascular Accident (CVA). The relevance of the study is to prove existence of a large number of caregivers of incapacitated patients, due to the CVA and it is not an academic research object, according to the literature. It is a qualitative research, which the guiding principle is the oral history of life, according to the theoretical foundation and operating of Meihy. Therefore, the following steps were highlighted: the target community, composed of all family caregivers of CVA patients; the colony, composed by family caregivers of CVA patients assisted by Home Care Service (HCS) of the Hospital José Pedro Bezerra (HJPB), in the city of Natal/RN; the network was composed of six caregivers who met the criteria for inclusion, and as zero point the first volunteer group. The population was composed of all family caregivers of patients attended by the HCS, of the HJPB having been addressed through interviews. For the empirical research there was the consent of that institution and approval by the Ethics Committee in Research of the Federal University of Rio Grande do Norte as CAAE 24569413.0.0000.5537 and, above all, with the acquiescence of employees in participating in the investigation, signing an informed consent. Of the empirical material, five categories of analysis were identified: the sense of being a caregiver; what has changed in the life of the caregiver; the feelings emerge in the relationship of care; the distance from family and friends; difficulties faced by the caregiver. The results show that the caregiver's life goes through profound transformations within the family as well as in all spheres of life. For the caregivers, assuming the care of a relative with CVA means renunciation and donation, compromising sometimes the individual projects and the family as a whole. In addition, they point out the confrontation of difficulties within the the assistance and humanization in healthcare, information, physical and emotional overload, as well as financial problems. Despite all the adversities that compromise the caregiver's life, it was possible to identify attitudes of resilience among caregivers, making them their daily life less strenuous and with more lightness. It is expected, therefore, that this research can contribute to a better orientation of professionals with the caregivers

Do discurso da resistência à resistência do discurso: as construções identitárias de Mossoró nos enunciados da literatura de cordel

This study has as objective to investigate the identity constructions of Mossoró, at the statements of the string literature. Having as thread the episode of resistance of the city against the group of Lampião at June the thirteenth of nineteen twenty seven, our study built itself at the statements present in nine strings, produced between the space-time of 1927 and 2007, year that Mossoró celebrated eighty years of the episode. Aware that the theme extrapolated the limits of the means of communication of the time and it became part of the everyday of the people from Mossoró, producing at the collective memory the image of a resistance city at the street’s names, at companies’ names, at radios’ names with the “FM Resistance”, at the discourses of the politicians, at the city hall which name is “Palace of the Resistance”, the central question that guides our investigation congregates the discussion around the dialogical relations done at the statements about the theme in vogue. This bias, the research elected as categories of analysis the concept of social voices and chronology, considering that the different identities are produced according to placements made by the subjects, as well as, by the context of production. Admitted at the area of Applied Linguistics (AL) and its line language and pratic of social the research articulates the theorizations provided from the area of Cultural Studies (especially regarding identity) with the theoretical framework of the bakhitinian Circle (regarding the social-historical conception of language and in its dialogical character). The results indicate that even existing an axiological movement around the representations of Mossoró and of the episode of 1927, the statements of the strings converge to a hegemonic discourse, corroborating with the identity profile of resistance transported over eighty decades

A Experiência como ordenação da realidade: uma estratégia orgânica para a educação científica

Knowledge is understanding. According to the philosopher Gaston Bachelard our immediate contact with the reality is only worth as confusing and provisional data. This phenomenological contact requires inventory and classification. For this reason our first reading on any phenomenon is limited to a basic levels of reality. Elements such as dynamics, functioning or detailed characteristics of what is observed can only be accessed at higher levels of reality, explains the physicist Werner Heisenberg. The ideas woven by these two great intellectuals oxygenates the notion that a well-made thinking does not require only observation and description of the nature, but assigns value and meaning to the knowledge. Based on these ideas and on the cognitive horizon brought by the complexity sciences, this research aims to nurture a reflection on our understanding of the world built from a rational perspective of experience, as an organic sequence of research. This arguments, over the study, describes how the experience is able to oxygenate a well-made thinking, as the concept created by Edgar Morin and expanded by Conceição Almeida. I argue that the experience as a path of investigative research allows one to ventures in the shadows of the unknown to access upper layers of reality. The experience is, therefore, an organic strategy for a well-made thinking - A nutritious mud that oxygenates, regulates, repairs and configures the quality of understanding. As a thread to discuss this ideas I've used my professional journey over a year and a half as a Natural Sciences' teacher on the Federal University of Rio Grande do Norte, where I could see how experiences helped on breaking a simplified understanding of the world. I chose to work with the research problems developed by 398 students over these three semesters. The problems were essential to the questioning of the phenomena that once seemed obvious or uninteresting, bringing out operational reasons and dynamics of the observed structures. Experience, in this sense, is the founder of dynamic thinking, as the need to deconstruct the phenomena's first impressions, assigning value and meaning to gestated knowledge.

Encapsulamento de solventes em nanotubos de haloisita para promoção de auto-reparo em polímeros

Micro cracking during service is a critical problem in polymer structures and polymer composite materials. Self-healing materials are able to repair micro cracks, thus their preventing propagation and catastrophic failure of structural components. One of the self-healing approaches presented in the literature involves the use of solvents which react with the polymer. The objective of this research is to investigate a procedure to encapsulate solvents in halloysite nanotubes to promote self-healing ability in epoxy. Healing is triggered by crack propagation through embedded nanotubes in the polymer, which then release the liquid sovent into the crack plane. Two solvents were considered in this work: dimethylsulfoxide (DMSO) and nitrobenzene. The nanotubes were coated using the layer-by-layer technique of oppositely charged polyelectrolytes: cetyltrimethylammonium bromide (CTAB) and sodium polyacrylate. Solvent encapsulation was verified by X-ray diffraction (XRD), Fourier transform infrared (FTIR), analysis thermogravimetry (TGA), adsorption and desorption of nitrogen and scanning electron microscopy (SEM). The introduction of the solvent DMSO into the cavity of the nanotubes was confirmed by the techniques employed. However, was not verified with nitrobenzene only promoted clay aggregation. The results suggest that the CTAB reacted with the halloystite to form a sealing layer on the surface of the nanotubes, thus encapsulating the solvent, while this was not verified using sodium polyacrylate.

Produção e análise do desempenho óptico e elétrico de filmes finos de SnO2:F para aplicações fotovoltaicas

Conselho Nacional de Desenvolvimento Científico e Tecnológico - CNPq

Aplicação de géis de goma guar no processo de clarificação de salmouras e águas produzidas

Produced water is considered the main effluent of the oil industry, due to their increased volume in mature fields and its varied composition. The oil and grease content (TOG) is the main parameter for the final disposal of produced water. In this context, it is of great significance to develop an alternative method based on guar gum gel for the treatment of synthetic produced water, and using as the differential a polymer having high hydrophilicity for clarifying waters contaminated with oil. Thus, this study aims to evaluate the efficiency of guar gum gels in the remotion of oil from produced water. Guar gum is a natural polymer that, under specific conditions, forms three-dimensional structures, with important physical and chemical properties. By crosslinking the polymer chains by borate ions in the presence of salts, the effect salting out occurs, reducing the solubility of the polymer gel in water. As a result, there is phase separation with the oil trapped in the collapsed gel. The TOG was quantified from the spectroscopy in the ultraviolet and visible region. The system was proven to be highly efficient in the removal of dispersed oil from water produced synthetically, reaching removal percentages above 90%.

Tratamento de argila montmorilonítica para a produção de nanocompósitos poliméricos com retardo de propagação de chama

Compared to conventional composites, polymer matrix nanocomposites typically exhibit enhanced properties at a significantly lower filler volume fraction. Studies published in the literature indicate t hat the addition of nanosilicate s can increase the resistance to flame propagation in polymers. In this work, a treatment of montmorillonite (MMT) nano clay and the effect of its ad dition o n flame propagation characteristics of vinyl ester were studied. The resea rch was conducted in two stages. The first stage focused on the purification and activation of the MMT clay collected from a natural deposit to improve compatibility with the polymer matrix . Clay modification with sodium acetate was also studied to improve particle dispersion in the polymer. The second step was focused on the effect of the addition of the treated clay on nanocomposites ’ properties. Nanocomposites with clay con tents of 1, 2, 4 wt. % were processed. T he techniques for the characterization of the clay included X - ray fluorescence (XRF), X - r ay d iffraction (XRD), thermogravimetric a nalysis (TGA), d ifferential scanning c alorimetry (DSC) , s urface area (BET) and Fourier transform infrared spectroscopy (FTIR). For t he characterization of the nanocomposites , the techniques used were thermogravimetric a nalysis (TGA) , differential scanning c alorimetry (DSC), Fourier transform infrared spectroscopy (FTIR) , scanning electron mi croscopy (SEM), transmission electron m icroscopy (TEM), and the determination of tensile strength, modulus of elasticity and resistance to flame propagation. According to the results, the purification and activation treatment with freeze - drying used in thi s work for the montmorillonite clay was efficient to promote compatibility and dispersion in the polymer matrix as evidenced by the characterization of the nanocomposite s . It was also observed that the clay modifica tion using sodium acetate did not produce any significant effect to improve compatibilization of the clay with the polymer. The addition of the treated MMT resulted in a reduction of up to 53% in the polymer flame propagation speed and did not affect the mechanical tensile strength and modulus o f elas ticity of the polymer, indicating compatibility between the clay and polymer. The effectiveness in reducing flame propagation speed peaked for nanocomposites with 2 wt. % clay, indicating that this is the optimum clay concentration for this property. T he clay treatment used in this work enables the production of vinylester matrix nanocomposites with flame - retardancy properties .

Micropartículas contendo nanopartículas de quitosana usando sulfato e genipina para liberação modificada da triancinolona: obtenção, caracterização e estudo em células tumorais

Chitosan is a polymer biocompatibility and biodegradability widely used in drug delivery systems. The co-crosslinking of chitosan with sodium sulfate and genipin, to form particulate systems is related of making them more resistant to acidic pH and to modulate the release kinetics for the oral route. Triamcinolone is a glucocorticoid with anti-inflammatory and immunosuppressive actions. The nanoparticles were prepared by co-crosslinking and characterized for particle size, PDI, zeta potential, crosslinking degree, encapsulation rate, morphology, infrared spectroscopy, thermal analysis, release kinetics and cells studies. The nanoparticles were prepared initially without genipin with sodium sulphate and the particles parameters were monitored in function of different ratio of drug / polymer, different concentrations of sodium sulfate and polysorbate 80 and the drip mode of crosslinkers on polymers. After optimizing conditions, the chosen system parameters without genipin included mean diameter of 312.20 ± 5.70 nm, PDI 0.342 ± 0.013 and zeta potential of 20.18 ± 2.28 mV. The genipin was introduced into the system analyzing different concentrations (0.5, 1.0 and 2.0 mM) and crosslinking times (3, 6, 12 and 24 h). Evaluating crosslinking time with genipin (0.5 mM) it was showed that varying the genipin reaction time the systems size ranged from 235.1 to 334.4 nm, the PDI from 0.321 to 0.392 and zeta potential 20.92 to 30.39 mV. The crosslinking degree that coud vary from 14 to 30 %. Nanoparticles without genipina, 6 h and 24 h crosslinking time were dried by spray-drying method. Analysis by scanning electron micrograph (SEM) revealed that the microparticles showed spherical morphology. The encapsulation rate was 75 ± 2.3 % using validated HPLC methodology. The infrared analysis showed chemical interactions between the components of the formulation. Thermal analysis showed that systems with a higher degree of crosslinking had a higher thermal stability. On release kinetics, increasing the degree of crosslinking was able to decrease the concentration and rate of release of triamcinolone. In studies with liver cancer cells (HepG2) and colon (HT-29), the microparticulate prepared with triamcinolone and 24 h of crosslinking with genipin showed a potential for antitumor activity in hepatic cell line HepG2. Therefore, a new delivery system for triamcinolone on polymeric nanoparticles of chitosan cocrosslinked with genipin and sodium sulfate was obtained with hepatic antitumor potential.

Síntese e caracterização de nanopartículas magnéticas de Co e Ni com aplicação em magneto hipertermia

Nanoparticles are importante for the study of new phenomena and for the development of new applications. Metallic magnetic nanoparticles like Cobalt and Nickel are important for their applications in nanoscience and nanotechnology. In this work, we report on the synthesis and characterization of Ni and Co nanoparticles. The nanoparticles were prepared by the modi- ed sol-gel method and were formed in the pore-network of the biopolymer quitosan. The reduction occurred in absence of H2 ux. The metallic particles and their monoxides have a face-centered- cubic structure. The metallic particles sizes ranged from 59 to 77 nm and from 19 to 50 nm for Ni and Co, respectively. Their monoxides chemically passivated the metallic cores, and after several weeks we have not observed further increase in oxidation. The synthesis method was tuned to obtain mainly the ferromagnetic phase. The system behaves like a core/shell structure with a ferromagnetic core and an antiferromagnetic shell. Exchange bias e ect was observed at temperatures below the Néel temperature. Both systems were submitted to an alternated magnetic eld and the heat released by the particles increased the temperature to 140°C in an interval of 5 min. Similar studies in samples dispersed in water increased the temperatures to 40-59°C, these results suggest that these materials are candidates for magnetic hyperthermia.

Narrativa transmídia e a expansão do universo ficcional: os princípios e as estratégias de transmidiação da telenovela Cheias de Charme

This research analyzes the transmedia narrative television series Cheias de Charme, understood as a fictional multiplatform world, composed of several pieces distributed in different media, and into the context of media convergence. With a view to its expansion in various media controlled by production, we investigated how the principles (Jenkins 2008, 2009a, 2009b) and the strategies of expansion and spread (Fechine et al., 2013) were appropriate for fiction. To do this, literature reviews were conducted about transmidiation processes and the specifics of transmedia narrative, in order to identify possible areas of action and forms of engagement with the public. In addition, he reflected on reconfigurations of the soap opera genre in the era of participatory culture. For a better understanding of the dissertation, the observations were divided into four distinct chapters, taking as a guide and starting point the inclusion of the soap opera in the internet environment. With the aid of a descriptive research with a view to the application of the Case Study procedure in the light of Gil contributions (2010), it is believed that the proposed objectives were achieved. Finally, it was concluded that Cheias de Charme, aired by TV Globo in 2012, in time of 19h, we used creative and planned actions that have worked effectively in developing a transmedia narrative.

Narrativa transmídia e a expansão do universo ficcional: os princípios e as estratégias de transmidiação da telenovela Cheias de Charme

This research analyzes the transmedia narrative television series Cheias de Charme, understood as a fictional multiplatform world, composed of several pieces distributed in different media, and into the context of media convergence. With a view to its expansion in various media controlled by production, we investigated how the principles (Jenkins 2008, 2009a, 2009b) and the strategies of expansion and spread (Fechine et al., 2013) were appropriate for fiction. To do this, literature reviews were conducted about transmidiation processes and the specifics of transmedia narrative, in order to identify possible areas of action and forms of engagement with the public. In addition, he reflected on reconfigurations of the soap opera genre in the era of participatory culture. For a better understanding of the dissertation, the observations were divided into four distinct chapters, taking as a guide and starting point the inclusion of the soap opera in the internet environment. With the aid of a descriptive research with a view to the application of the Case Study procedure in the light of Gil contributions (2010), it is believed that the proposed objectives were achieved. Finally, it was concluded that Cheias de Charme, aired by TV Globo in 2012, in time of 19h, we used creative and planned actions that have worked effectively in developing a transmedia narrative.

Efeito da força iônica nas propriedades de fluidos de perfuração aquosos à base de polímeros carboxilados e sulfatados

In the well drilling operations problems caused by contamination of the drilling fluid are common. The dissolution of ions from the geological formations affects the rheological and filtration properties of the fluids. These ions shield the charges of ionic polymers, leading to its precipitation. In this work was performed a detailed study on the stability of the properties of aqueous solutions and aqueous drilling fluids in the presence of sulphated and carboxylated polymers, using carboxymethylcellulose and kappa-carrageenan as polymer compounds carboxylated and sulfated model, respectively. The effects of ionic strength of the aqueous medium containing Na+, Mg2+ and Ca2+ on rheological properties of the polymer and drilling fluids solutions were evaluated by varying the concentration of salts, pH and temperature. It was observed that the fluids with κ-carrageenan suffered less influence against the contamination by the ions at pH 9 to 10, even at higher concentrations, but higher influence on pH> 11. The fluids containing carboxymethylcellulose were more sensitive to contamination, with rapid reduction in viscosity and significant increase of the filtrate volume, while the fluid based polymer sulfated kappa-carrageenan showed evidence of interaction with cations and preserve the rheological properties and improved stability the volume of filtrate.

Efeito da força iônica nas propriedades de fluidos de perfuração aquosos à base de polímeros carboxilados e sulfatados

In the well drilling operations problems caused by contamination of the drilling fluid are common. The dissolution of ions from the geological formations affects the rheological and filtration properties of the fluids. These ions shield the charges of ionic polymers, leading to its precipitation. In this work was performed a detailed study on the stability of the properties of aqueous solutions and aqueous drilling fluids in the presence of sulphated and carboxylated polymers, using carboxymethylcellulose and kappa-carrageenan as polymer compounds carboxylated and sulfated model, respectively. The effects of ionic strength of the aqueous medium containing Na+, Mg2+ and Ca2+ on rheological properties of the polymer and drilling fluids solutions were evaluated by varying the concentration of salts, pH and temperature. It was observed that the fluids with κ-carrageenan suffered less influence against the contamination by the ions at pH 9 to 10, even at higher concentrations, but higher influence on pH> 11. The fluids containing carboxymethylcellulose were more sensitive to contamination, with rapid reduction in viscosity and significant increase of the filtrate volume, while the fluid based polymer sulfated kappa-carrageenan showed evidence of interaction with cations and preserve the rheological properties and improved stability the volume of filtrate.