Ondaletas e movimento browniano fracionário: aplicação à caracterização de poços de petróleo

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior

Fractais e percolação na recuperação de Petróleo

The complex behavior of a wide variety of phenomena that are of interest to physicists, chemists, and engineers has been quantitatively characterized by using the ideas of fractal and multifractal distributions, which correspond in a unique way to the geometrical shape and dynamical properties of the systems under study. In this thesis we present the Space of Fractals and the methods of Hausdorff-Besicovitch, box-counting and Scaling to calculate the fractal dimension of a set. In this Thesis we investigate also percolation phenomena in multifractal objects that are built in a simple way. The central object of our analysis is a multifractal object that we call Qmf . In these objects the multifractality comes directly from the geometric tiling. We identify some differences between percolation in the proposed multifractals and in a regular lattice. There are basically two sources of these differences. The first is related to the coordination number, c, which changes along the multifractal. The second comes from the way the weight of each cell in the multifractal affects the percolation cluster. We use many samples of finite size lattices and draw the histogram of percolating lattices against site occupation probability p. Depending on a parameter, ρ, characterizing the multifractal and the lattice size, L, the histogram can have two peaks. We observe that the probability of occupation at the percolation threshold, pc, for the multifractal is lower than that for the square lattice. We compute the fractal dimension of the percolating cluster and the critical exponent β. Despite the topological differences, we find that the percolation in a multifractal support is in the same universality class as standard percolation. The area and the number of neighbors of the blocks of Qmf show a non-trivial behavior. A general view of the object Qmf shows an anisotropy. The value of pc is a function of ρ which is related to its anisotropy. We investigate the relation between pc and the average number of neighbors of the blocks as well as the anisotropy of Qmf. In this Thesis we study likewise the distribution of shortest paths in percolation systems at the percolation threshold in two dimensions (2D). We study paths from one given point to multiple other points. In oil recovery terminology, the given single point can be mapped to an injection well (injector) and the multiple other points to production wells (producers). In the previously standard case of one injection well and one production well separated by Euclidean distance r, the distribution of shortest paths l, P(l|r), shows a power-law behavior with exponent gl = 2.14 in 2D. Here we analyze the situation of one injector and an array A of producers. Symmetric arrays of producers lead to one peak in the distribution P(l|A), the probability that the shortest path between the injector and any of the producers is l, while the asymmetric configurations lead to several peaks in the distribution. We analyze configurations in which the injector is outside and inside the set of producers. The peak in P(l|A) for the symmetric arrays decays faster than for the standard case. For very long paths all the studied arrays exhibit a power-law behavior with exponent g ∼= gl.

Neurofisiologia hipocampal durante sessões de sono intercaladas por exploração espacial: Reverberação do passado ou predição do futuro?

The ability to predict future rewards or threats is crucial for survival. Recent studies have addressed future event prediction by the hippocampus. Hippocampal neurons exhibit robust selectivity for spatial location. Thus, the activity of hippocampal neurons represents a cognitive map of space during navigation as well as during planning and recall. Spatial selectivity allows the hippocampus to be involved in the formation of spatial and episodic memories, including the sequential ordering of events. On the other hand, the discovery of reverberatory activity in multiple forebrain areas during slow wave and REM sleep underscored the role of sleep on the consolidation of recently acquired memory traces. To this date, there are no studies addressing whether neuronal activity in the hippocampus during sleep can predict regular environmental shifts. The aim of the present study was to investigate the activity of neuronal populations in the hippocampus during sleep sessions intercalated by spatial exploration periods, in which the location of reward changed in a predictable way. To this end, we performed the chronic implantation of 32-channel multielectrode arrays in the CA1 regions of the hippocampus in three male rats of the Wistar strain. In order to activate different neuronal subgroups at each cycle of the task, we exposed the animals to four spatial exploration sessions in a 4-arm elevated maze in which reward was delivered in a single arm per session. Reward location changed regularly at every session in a clockwise manner, traversing all the arms at the end of the daily recordings. Animals were recorded from 2-12 consecutive days. During spatial exploration of the 4-arm elevated maze, 67,5% of the recorded neurons showed firing rate differences across the maze arms. Furthermore, an average of 42% of the neurons showed increased correlation (R>0.3) between neuronal pairs in each arm. This allowed us to sort representative neuronal subgroups for each maze arm, and to analyze the activity of these subgroups across sleep sessions. We found that neuronal subgroups sorted by firing rate differences during spatial exploration sustained these differences across sleep sessions. This was not the case with neuronal subgroups sorted according to synchrony (correlation). In addition, the correlation levels between sleep sessions and waking patterns sampled in each arm were larger for the entire population of neurons than for the rate or synchrony subgroups. Neuronal activity during sleep of the entire neuronal population or subgroups did not show different correlations among the four arm mazes. On the other hand, we verified that neuronal activity during pre-exploration sleep sessions was significantly more similar to the activity patterns of the target arm than neuronal activity during pre-exploration sleep sessions. In other words, neuronal activity during sleep that precedes the task reflects more strongly the location of reward than neuronal activity during sleep that follows the task. Our results suggest that neuronal activity during sleep can predict regular environmental changes

Expressão de zif268 no cérebro do lagarto Tropidurus Hispidus após exploração de um ambiente enriquecido.

In the present work, we investigated behavioral changes associated with the increase in Zif268 protein expression within telencephalic areas of the tropical lizard Tropidurus hispidus that correspond to the mammalian hippocampus (HC). We used 13 male individuals of this species, collected at the Federal Agrotechnical School of Rio Grande do Norte, under SISBIO license number 19561-1. Four animals had their brains removed and were submitted to a Western blot with antibodies for the Zif268 protein. The remaining animals were separated in two different groups: a control group (n=4) and an exploration group (n=5). Animals from the exploration group were exposed to an enriched environment with many sensory cues novel to them. Control group animals stayed in the environment they were already habituated to. After 90 min from the onset of exposure to the new environment, animals from both groups were submitted to intracardiac perfusion with fixative, and the brains were removed, cryoprotected and frozen. After that, brains were sectioned at 20 μm and the sections were subjected to immunohistochemistry for the Zif268 protein. We verified that the Zif268 protein is likely conserved in the brain of T. hispidus, which showed antigenicity for the antibody anti-Zif268 made in mammals. In animals from the exploration group, we detected an increase of the Zif268 protein in the Septum, Striatum, Dorsoventricular Area and in cortical areas corresponding to the HC. This increase was proportional to the amount of environmental exploration, with maximum positive correlation in the hippocampal subareas Medial Cortex (R = 0.94 and p = 0.004) and Dorsomedial Cortex (R = 0.92 and p = 0.006). The data corroborate the notion that the reptilian hippocampus, as well as the mammalian HC, plays an important role in spatial exploration.

Sexo não é brincadeira: o sentido de infância para adolescentes inseridas na exploração sexual comercial

The childhood has being highlighted by the great concern about the several contexts in which children are inserted, amongst them, commercial sexual exploitation (CSE). The experience of this violence process brings implications to the person constitution. Thus, this research aimed to understand how commercial sexual exploited adolescents to signify the childhood. Participated of this research four female adolescents that had been assisted by Programa de enfrentamento ao Abuso e Exploração Sexual de Crianças e Adolescentes (Sentinela) , with ages between 12 and 17 years. The corpus was composed by the combination of the semi-structured interview and other procedures, like childish stories, draws and photography. Moreover, we used another instruments to constitute the corpus, like the documental research and we proposed the construction of a life story book of each participant. The corpus was analyzed through the Thematic Content Analysis. Five thematic axes emerged from the participants discourse and theoretical perspective: dynamical of family, scholar process, ludic behavior, conception of childhood and insertion on CSE process. The participants presented a conception about childhood as been a preparation and education phase to ingress in adult life. In other words, while children do not grown up, they go to the school, plays, lives with family, are happy and do not have any responsibilities. Nevertheless, the life experience of these girls was implicated by negligence, sexual abuse, child labor, institutionalization and, evidently, the commercial sexual exploitation. Understanding that the childhood experienced by adolescent, as well as, her insertion on CSECA, constitutes her, while person, we investigated how the interrelation expresses it on participants future perspectives. Their goals are defined based on family constitution and professional improvement, although feelings of disillusion and pessimism had been showed up in some moments. According these results, we pointed to the necessity of the effective proposals that promote real improvement of adolescents life quality, through, in which they could to create alternatives to get over the several risks in which they are exposed, mainly, the CSECA condition

Exploração sexual comercial de crianças e adolescentes : o estado da arte nas produções acadêmicas em psicologia

The Commercial Sexual Exploitation of Children and Adolescents (ESCCA) is a phenomenon that has been given priority in public policy agenda of many democratic governments of Western countries and civil sectors of society, besides the object of studies in different fields of knowledge. Psychology is among these areas and is considered one of the references in the construction of knowledge and actions to confront the phenomenon. However, the epistemological foundations of psychological science are quite different, and so, several are his speeches, knowledge produced and ways of conceiving man and the world. This is evident in the publications of psychology on ESCCA. This work aims to achieve a state of the art of psychology publication in Brazil (in the post-graduation - through theses and dissertations - and journals) on the Commercial Sexual Exploitation of Children and Adolescents. More specifically try to evidence (a) what conceptions of commercial sexual exploitation of children and adolescents the authors lists, (b) what are aimed at research and publications, (c) how the research and issues are justified, and (d) that theoretical approaches the authors are affiliated and methodological possibilities are applied to range the aim proposed in their work. In order to do so, a survey was conducted in the major index sites (eg, BVS-Psi, Capes, theses and dissertations database of university libraries) of the material, covering the period 1990 to 2007. Through research on these sites, we built a database, including information relating to the work sought from specific descriptors for studies in the area of victimization of children and adolescents, with reference to a list provided by Faleiros (2000). After reading the summary of the work, the number of recovered 25 productions was reached - including theses, dissertations and articles. For analysis of the material used in the analysis of thematic content. Two axes themes were established in order to guide the analysis: conceptual elements of commercial sexual exploitation, and theoretical and methodological strategies employed. The axes have as reference for analysis a chapter built on the concept of commercial sexual exploitation, so that all analysis is anchored on it. The analysis points to the existence, still strong, conceptual and terminological confusion about ESCCA. Few studies have not demonstrated this confusion, maintaining a consistent theoretical approach. In relation to the theoretical and methodological strategies, there is a great diversity of approaches in psychology surrounding the phenomenon of ESCCA, enriching levels of understanding and action. This diversity reflects a constitutive heterogeneity of psychological science. We emphasize the perspective of socio-historical psychology, most frequently among the publications. It is hoped that this research will help advance the qualitative approach to ESCCA, especially in the field of psychology, as well as contribute to new research in the area and construction of new means of addressing this human rights violation

Efeitos do turno fixo sobre a saúde mental em operadores de petróleo :um estudo de caso em dois ativos produção da Petrobrás

Un conjunto de cambios viene siendo implantado en la Petrobrás procurando que sus unidades de negocios resulten más modernas y competitivas para atender las necesidades del mercado. Dentro de esta perspectiva, un nuevo régimen de trabajo, denominado turno fijo , ha sido implantado en dos activos de producción de la provincia de Rio Grande do Norte. Tal situación originó varios reclamos de los petroleros y, consecuentemente, el interés del SINDIPETRO-RN en obtener una evaluación más precisa de las consecuencias de los mismos. Este estudio, realizado a partir de la demanda sindical de esos trabajadores, ha tenido como objetivo central analizar los efectos del turno fijo sobre la salud mental de los operadores de producción, actualmente lotados en los referidos activos. El estudio ha sido realizado con 39 operadores que representan el 82,9% de la población objeto de este estudio. La muestra ha sido homogénea en cuanto al género, grado de instrucción, edad y tiempo de servicio en la compañía, lo que ha posibilitado un mayor control de las variables y un estudio comparativo entre los dos activos. Para el desarrollo del estudio, se han aplicado los siguientes instrumentos de colecta de datos: una escala de medida probada y validada (QSG-12), un cuestionario abierto, entrevistas individuales y una ficha socio-demográfica. Las respuestas del cuestionario abierto han sido categorizadas mediante la aplicación de análisis de contenido. Los resultados de ese tratamiento y las respuestas del QSG-12 han sido registradas en la forma de banco de datos del SPSS for Windows (Statical Package for social sciense for Windows) para luego procederse con el desarrolllo de los análisis estadísticos. Los principales resultados encontrados en el estudio han sido que la mitad de los participantes de la muestra han presentado resultados de deteriorización de la autoeficacia más elevado que 1,44 (un una escala de 0 a 3) y, en tensión emocional y depresión, el resultado es más elevado que 1,67; la mayoría se da cuenta del aumento de carga de trabajo, revela acentuado sufrimiento con el distanciamiento de la familia, y 58,8% presenta enfermedades psicosomáticas crónicas. La percepción de los operadores sobre el turno fijo e el análisis de éste, conforme el modelo vitamínico de Warr, conducen a la conclusión de que el turno fijo es uno de los factores que está influyendo negativamente en la salud mental de esos trabajadores

Saúde mental em operadores de petróleo do Rio Grande do Norte

The importance of identifying the consequence of the hours worked on people in society has been well recognized within Organizational and Work Psychology. From this point of view, the present research had the objective of analysing the effects of work regimes on the mental health of petroleum operators of Petrobrás. The sample totaled 144 subjects, corresponding to 27% of the work population. The mental health of the participants was evaluated using the following instruments of measurement: QSG-12, Scale of self-esteem, Scale of Positive and Negative Affections and the Scale of Valuable Attributes of IMST, each representing an empirical factor used to indicate and measure the five dimensions of mental health. The subjects perceptions of their work regime and the rest of their conditions of work were evaluated using scales of descriptive attributes of IMST, by applying a semi-structured questionnaire and by use of interviews. A socio-demographic file was used to collect information related to the biographical and socio-occupational profile of the worker sample. The answers to the questionnaire were inserted into the data bank of SPSS (Statistical Package for Social Science), for statistical analysis, and the interviews were analised based on the technique of Contents Analysis recommended by Bardin (1995). The main results revealed that one third of the worker sample were tense; however, the mental health of the majority was preserved. Cluster Analysis applied to the group of seven factors which measured the five dimensions of mental health identified four profiles of psychological well-being shared between members of the sample. It was observed that the people working in the system of Continuous Shift Alternation (TIR) and in the system of Pre-advising tended to present balanced and satisfactory profiles, while the ones which worked in the Administrative Field tended to present anxious and oscillating profiles, and thus were more affected psychologically. These were also the ones that also perceived the more negative aspects of their laborious conditions (reduced chances of self-improvement, physically stressful and financial resources below expectations with which to supply family and personal necessities. In agreement with the ecological model formulated by Warr (1987), the present study concluded that the positive and negative effects on the psychological well-being tended to occur as a consequence of the perceptions the petrol operators developed to face their work conditions

Síntese enzimática de biosurfactante e sua aplicabilidade na indústria do petróleo

Enzymes have been widely used in biosynthesis/transformation of organic compounds in substitution the classic synthetic methods. This work is the first writing in literature of enzymatic synthesis for attainment the biossurfactants, the use glucose sucrose, ricinoleic acid e castor oil as substratum, and as biocatalyst, used immobilized lipase Thermomyces lanuginose, Rhizomucor miehei and the Candida antarctica lipase B; alkaline protease and neutral protease from Bacillus subtillis and yeast Saccharomyces cerevisiaeI. The analysis of HPLC (high performance liquid chromatography) showed that highest conversions were reached of used the alkaline protease from Bacillus subtillis. Laboratory tests, to evaluate the applicability, indicated that the produced biosurfactantes had good stability in presence of salts (NaCl) and temperature (55 e 25°C), they are effective in the reduction of the superficial tension and contac angle, but they have little foaming capacity, when compared with traditional detergents. These results suggest that the prepared surfactants have potential application as wetting agent and perforation fluid stabilizer

Obtenção e aplicação de sistemas microemulsionados na recuperação avançada de petróleo

Due to the need of increasing production in reservoirs that are going through production decline, methods of advanced recovery have frequently been used in the last years, as the use of conventional methods has not been successful in solving the problem of oil drifting. In this work, the efficiency of different microemulsionated systems in the flow of oil from cores from Assu and Botucatu formations. Regarding drifting tests, cores were calcinated at a temperature of 1000°C, for 18 hours, with the aim of eliminating any organic compound present in it, increasing the resultant permeability. Following, the cores were isolated with resin, resulting in test specimens with the following dimensions: 3.8 cm of diameter and 8.7 cm of length. Cores were saturated with brine, composed of aqueous 2 wt % KCl, and oil from Guamaré treatment station (Petrobras/RN). A pressure of 20 psi was used in all tests. After core saturation, brine was injected again, followed by oil at constant flow rate. The system S3 - surfactant (anionic surfactant of short chain), isoamillic alcohol, pine oil, and water - presented the best drift efficiency, 81.18%, while the system S1E commercial surfactant, ethyl alcohol, pine oil, and distilled water presented low drift efficiency, 44,68%

Estudo da modificação de bentonita para a remoção de fenol em águas produzidas na indústria de petróleo

This study evaluates the inclusion of quaternary ammonium salt, bromide hexadecyl trimethyl ammonium (HDTMA-Br) on sodium bentonite to evaluate their performance on the adsorption of phenol present in produced water. It was observed an increase in d001 samples modified with HDTMA-Br by diffraction of X-rays, showing the intercalation of quaternary ammonium cations in the interlamellar layers of clay. Through the adsorption isotherms could be abserver adsorption behavior of sodium bentonite and organophilic bentonite produced in three different concentrations of HDTMA-Br for adsorption of phenol, which is the main phenolic compound found in the product water. Different concentrations of synthetic solutions of phenol were placed in contact with these adsorbents under the same conditions of agitation and temperature. The adsorbent showed adsorptive favorable, especially the clay modified with the highest concentration of HDTMA-Br, 150% CEC of clay, BEN30-14, with higher amounts of phenol adsorbed per gram of adsorbent (mg.g-1)

Análise química de produtos de incrustação em dutos de petróleo por espectometria de fluorescência de raios X

The quantitative chemical characterization of the inorganic fraction of scale products is very relevant in studying, monitoring and controlling corrosive processes of oil pipelines. The X-ray fluorescence spectrometry (XRF) is a very versatile analytical technique, which can be used in quantitative analysis in solid samples at low concentrations of the chemical element, in the order of few ppm. A methodology that involves sample preparation diluted in the proportion of 1:7 (one portion of the sample for seven of wax), pressed as pellets was used in the XRF calibration for chemical analysis of scale products from oil pipelines. The calibration involved the preparation of reference samples from mixtures of P.A. reagents, aiming to optimize the time consumed in the steps of sample preparation and analysis of Al, Ba, Ca, Fe, K, Mg, Mn, Na, P, S, Si, Sr and Ti, using the same pressed pellet for trace and major elements analysis

Síntese, caracterização e aplicação do MCM-41 e A1-MCM-41 na pirólise do resíduo atmosférico de petróleo

In present work, mesoporous materials of the M41S family were synthesized, which were discovered in the early 90s by researchers from Mobil Oil Corporation, thus allowing new perspectives in the field of catalysis. One of the most important members of this family is the MCM-41, which has a hexagonal array of mesopores with pore diameters ranging from 2 to 10 nm and a high surface area, enabling it to become very promising for the use as a catalyst in the refining of oil in the catalytic cracking process, since the mesopores facilitate the access of large hydrocarbon molecules, thereby increasing the production of light products, that are in high demand in the market. The addition of aluminum in the structure of MCM-41 increases the acidity of the material, making it more beneficial for application in the petrochemical industry. The mesoporous materials MCM-41 and Al-MCM-41 (ratio Si / Al = 50) were synthesized through the hydrothermal method, starting with silica gel, NaOH and distilled water. CTMABr was used as template, for structural guiding. In Al-MCM-41 the same reactants were used, with the adding of pseudoboehmite (as a source of aluminum) in the synthesis gel. The syntheses were carried out over a period of four days with a daily adjustment of pH. The optimum conditions of calcination for the removal of the organic template (CTMABr) were discovered through TG / DTG and also through analysis by XRD, FTIR and Nitrogen Adsorption. It was found that both the method of hydrothermal synthesis and calcination conditions of the studies based on TG were promising for the production of mesoporous materials with a high degree of hexagonal array. The acidic properties of the materials were determined by desorption of n-butylamine via thermogravimetry. One proved that the addition of aluminum in the structure of MCM-41 promoted an increase in the acidity of the catalyst. To check the catalytic activity of these materials, a sample of Atmospheric Residue (RAT) that is derived from atmospheric distillation of oil from the Pole of Guamaré- RN was used. This sample was previously characterized by various techniques such as Thermogravimetry, FTIR and XRF, where through thermal analysis of a comparative study between the thermal degradation of the RAT, the RAT pyrolysis + MCM-41 and RAT + Al- MCM-41. It was found that the Al-MCM-41 was most satisfactory in the promotion of a catalytic effect on the pyrolysis of the RAT, as the cracking of heavy products in the waste occurred at temperatures lower than those observed for the pyrolysis with MCM-41, and thereby also decreasing the energy of activation for the process and increasing the rates of conversion of residue into lighter products

Análise dos Processos de Flotação e Oxidação Avançada para o Tratamento de Efluente Modelo da Indústria do Petróleo

The generation of wastes in most industrial process is inevitable. In the petroleum industry, one of the greatest problems for the environment is the huge amount of produced water generated in the oil fields. This wastewater is a complex mixture and present great amounts. These effluents can be hazardous to the environmental without adequate treatment. This research is focused in the analysis of the efficiencies of the flotation and photo-oxidation processes to remove and decompose the organic compounds present in the produced water. A series of surfactants derivated from the laurilic alcohol was utilized in the flotation to promote the separation. The experiments have been performed with a synthetic wastewater, carefully prepared with xylene. The experimental data obtained using flotation presented a first order kinetic, identified by the quality of the linear data fitting. The best conditions were found at 0.029 g.L-1 for the surfactant EO 7, 0.05 g.L-1 for EO 8, 0.07 g.L-1 for EO 9, 0.045 g.L-1 for EO 10 and 0.08 g.L-1 for EO 23 with the following estimated kinetic constants: 0.1765, 0.1325, 0.1210, 0.1531 and 0.1699 min-1, respectively. For the series studied, the most suitablesurfactant was the EO 7 due to the lower reagent consumption, higher separation rate constant and higher removal efficiency of xylene in the aqueous phase (98%). Similarly to the flotation, the photo-Fenton process shows to be efficient for degradation of xylene and promoting the mineralization of the organic charge around 90% and 100% in 90 min

Hidrólise e caracterização de poliacrilamida hidrofobicamente modificada: avaliação da aplicabilidade na recuperação de petróleo

The hydrolysis reaction in alkaline conditions of the commercial polymer poly(acrylamide-co-metacrylate of 3,5,5-trimethyl-hexane) called HAPAM, containing 0.75 % of hydrophobic groups, was carried out in 0.1 M NaCl and 0.25M NaOH solutions, varying the temperature and reaction time. The polymers were characterized by 1H and 13C Nuclear Magnetic Resonance (NMR), Elemental Analysis and Size Exclusion Chromatography (SEC). The values of the hydrolysis degree were obtained by 13C NMR. The viscosity of HAPAM and HAPAM-10N-R solutions was evaluated as a function of shear rate, ionic strength and temperature. At high polymer concentration (Cp), the viscosity of HAPAM solutions increased with the ionic strength and decreased with the temperature. The viscosity of HAPAM-10N-R solutions increased significantly in distilled water, due to repulsions between the carboxylate groups. At high Cp, with the increase of ionic strength and temperature, occurred a decrease of viscosity, due to mainly the high hydrolysis degree and the low amount of hydrophobic groups. These results indicated that the studied polymers have properties more suitable for the application in Enhanced Oil Recovery (EOR) in low salinity and moderate temperature reservoirs