102 resultados para Aqüífero fissural


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Perfis de alteração em basaltos com baixos teores de Ti02 (LTiB) da Parte Sudeste da Bacia do Paraná (SPB) associam-se a superfícies aplainadas, nos planaltos das Araucárias (Ab' Saber, 1973), entre altitudes de 950 m a 750 m (Vacaria) e 1000m a 920m (a Sul de Lages). Em domínios mais dissecados do relevo, que crescem de Este para Oeste, e nas encostas intensamente dissecadas destes planaltos a Sul (calha do rio Antas) e a Norte (calha do rio Pelotas), os perfis de alteração são truncados ou inexistentes. A associação dos perfis de alteração com superfícies geomorfológicamente mais antigas (aplainadas e elevadas) faz supor que o início dos processos de alteração seja correlativo às superfícies aplainadas, antigo e, provável mente, Terciário. As sequências de alteração mais completas localizam-se em morros de topo plano e apresentam as seguintes fácies: Rocha mãe, saprólito, alterito argiloso, alterito esferoidal, "stone line", coberturas móveis e solo atual. Químicamente os produtos de alteração intempérica dos basaltos são "lateritas" segundo definição de Schellmann (1981), com enriquecimento em Fe2D.3 e H20; perdas em Si02, FeO, MgO, CaO, Na20 e K20; prováveis pequenas perdas emA12D.3. No saprólito, os pedaços de rocha fragmentada permitiram a descrição das alterações hidrotermais refletidas nas para gêneses dos sítios intersticiais, constitui dos por materiais cristalinos e criptocristalinos. Os cristais de titanomagnetita aparecem com manchas azuis irregulares que sugerem variações cristaloquímicas contínuas dentro de um mesmo cristal, típicas da maghemitização. O alterito argiloso é sede de pseudomorfoses dos minerais magmáticos e hidrotermais. Esmectitas, ocupam os sítios das camadas mistas hidrotermais; halloysitas 7 e 10 Á são dominantes nos plasmas das pseudomorfoses de plagioclásios e plasmas ricos em ferro e sílica predominam nas pseudomorfoses de piroxênios. Observa-se a transição halloysita -caolinita desordenada rica em ferro estrutural nas partes superiores do conjunto. Os plasmas secundários são silico-aluminosos, nas partes baixas do conjunto, e predominantemente opacos no topo. Estes plasmas constituem-se de halloysita, litioforita (ou plasma rico em Mn), goethita e maghemita. O alterito esferoidal apresenta o núcleo de rocha e um córtex de cor amarelo -alaranjada em que se verifica a presença dominante da goethita aluminosa. Secundáriamente, aparecem cristobalita, maghemita e gibbsita. As coberturas móveis, são constitui das de plasma caolinítico e plasmas ricos em hematita e goethita. Aparecem ainda grânulos, pisólitos e nódulos herdados de antigas couraças desmanteladas. Os minerais, formados em condições lateritizantes, são os filossilicatos halloysita 7Á e lOÁ, caolinita desordenada e os óxidos e hidróxidos, hematita, goethita, gibbsita e litioforita.Observou-se que a mineralogia de alteração está intimamente associada à textura da rocha original. Encontram-se, ainda, nestes horizontes de alteração intempérica, a cristobalita (metaestável) e a titanomaghemita. As titanomaghemitas identificadas nos saprólitos e alteritos apresentam as características de maghemitização: diminuição da taxa 32(Fe+ Ti)/O, aumento de lacunas na malha cristalina e diminuição do parâmetro ~. Mg diminui com o intemperismo, Mn e AI se concentram nas fases magnéticas. A halloysita 7Á predomina sobre a lOÁ, na fração < 2Jlm, do alterito argiloso, alterito esferoidal e no sistema fissural. A caolinita predomina no horizonte "tacheté". No alterito esferoidal, ocorre também caolinita e esmectita. As argilas halloysíticas apresentam quatro morfologias: esferas, tubos, lamelas planares e cones. A halloysita forma-se preferencialmente à caolinita no córtex de alteração do alterito esferoidal e na fácies argilosa, constituindo um primeiro estágio de intemperismo. Os tubos e cones têm os menores teores de Fe2Ü3 enquanto as halloysitas planares têm os mais altos teores de Fe2Ü3. O teor de Fe das partículas esferoidais é variado. Os óxidos e hidróxidos destes perfis caracterizaram variações da atividade a água, de atividade da sílica dissolvida e temperatura, refletindo as paleocondições (climáticas) de formação destas coberturas fósseis.

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Concentrações de fluoreto, até 11 mg L-1, têm sido detectadas no aqüífero da Formação Santa Maria, Sistema Aqüífero Guarani, na região central do Estado do Rio Grande do Sul, Brasil. As águas subterrâneas são utilizadas para abastecimento público e levaram a incidência de fluorose dental. Esta área é a maior produtora de tabaco no Brasil, com uma longa história de aplicação de fertilizantes. Duas hipóteses são investigadas na busca de elucidar a origem das anomalias de flúor, a primeira, se refere à contaminação desencadeada pelo uso de fertilizantes fosfatados nas plantações de tabaco, e a segunda relacionada à causa natural, geogênica, determinada por interações rocha-fluido no aqüífero confinado. A hipótese antropogênica é testada nos solos e águas do aqüífero freático. O monitoramento das concentrações de fluoreto em campo, durante o período de dois anos e os experimentos de laboratório de retenção e lixiviação de fluoreto em solos mostram que este elemento é retido pelos solos argilosos. Durante o período de monitoramento das águas do freático, concentrações maiores que 0,16 mg L-1 não foram registradas, confirmando que o fluoreto é sorvido pelos solos argilosos ou transportado para horizontes mais permeáveis para superfície ou água subterrânea, em processo lento. Análise estatística fatorial e de agrupamento associada a técnicas de modelamento geoquímico apontaram as afinidades químicas das águas subterrâneas e possíveis origens para o fluoreto. As águas subterrâneas da Formação Santa Maria são distinguidas em quatro grupos hidroquímicos, o primeiro, cloretado sódico, evolui para águas subterrâneas bicarbonatadas sódicas, e ambos grupos apresentam anomalias de fluoreto. O terceiro grupo é de águas bicarbonatadas cálcicas e o quarto tem o magnésio como parâmetro característico. As hipóteses lançadas são também discutidas com base em análises de isótopos estáveis da água, e de sulfato e nitrato dissolvidos nas águas subterrâneas, que indicam a precipitação meteórica como a principal fonte de recarga do aqüífero estudado. A composição isotópica do sulfato da água é similar a do sulfato nos fertilizantes, não sendo possível distingui-lo de outras fontes que também apresentam assinaturas isotópicas semelhantes. No entanto, os isótopos do nitrato dissolvido nas águas subterrâneas e dos fertilizantes sugerem que não existe uma relação direta com o uso de fertilizantes NPK. Os dados apresentados indicam que os elevados teores de fluoreto no aqüífero da Formação Santa Maria resultam de interações água-rocha associadas à circulação de fluídos em estruturas tectônicas regionais levando a mistura de águas subterrâneas de aqüíferos mais profundos.

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Electrical resistive heating (ERH) is a thermal method used to improve oil recovery. It can increase oil rate and oil recovery due to temperature increase caused by electrical current passage through oil zone. ERH has some advantage compared with well-known thermal methods such as continuous steam flood, presenting low-water production. This method can be applied to reservoirs with different characteristics and initial reservoir conditions. Commercial software was used to test several cases using a semi-synthetic homogeneous reservoir with some characteristics as found in northeast Brazilian basins. It was realized a sensitivity analysis of some reservoir parameters, such as: oil zone, aquifer presence, gas cap presence and oil saturation on oil recovery and energy consumption. Then it was tested several cases studying the electrical variables considered more important in the process, such as: voltage, electrical configurations and electrodes positions. Energy optimization by electrodes voltage levels changes and electrical settings modify the intensity and the electrical current distribution in oil zone and, consequently, their influences in reservoir temperature reached at some regions. Results show which reservoir parameters were significant in order to improve oil recovery and energy requirement in for each reservoir. Most significant parameters on oil recovery and electrical energy delivered were oil thickness, presence of aquifer, presence of gas cap, voltage, electrical configuration and electrodes positions. Factors such as: connate water, water salinity and relative permeability to water at irreducible oil saturation had low influence on oil recovery but had some influence in energy requirements. It was possible to optimize energy consumption and oil recovery by electrical variables. Energy requirements can decrease by changing electrodes voltages during the process. This application can be extended to heavy oil reservoirs of high depth, such as offshore fields, where nowadays it is not applicable any conventional thermal process such as steam flooding

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In Brazil and around the world, oil companies are looking for, and expected development of new technologies and processes that can increase the oil recovery factor in mature reservoirs, in a simple and inexpensive way. So, the latest research has developed a new process called Gas Assisted Gravity Drainage (GAGD) which was classified as a gas injection IOR. The process, which is undergoing pilot testing in the field, is being extensively studied through physical scale models and core-floods laboratory, due to high oil recoveries in relation to other gas injection IOR. This process consists of injecting gas at the top of a reservoir through horizontal or vertical injector wells and displacing the oil, taking advantage of natural gravity segregation of fluids, to a horizontal producer well placed at the bottom of the reservoir. To study this process it was modeled a homogeneous reservoir and a model of multi-component fluid with characteristics similar to light oil Brazilian fields through a compositional simulator, to optimize the operational parameters. The model of the process was simulated in GEM (CMG, 2009.10). The operational parameters studied were the gas injection rate, the type of gas injection, the location of the injector and production well. We also studied the presence of water drive in the process. The results showed that the maximum vertical spacing between the two wells, caused the maximum recovery of oil in GAGD. Also, it was found that the largest flow injection, it obtained the largest recovery factors. This parameter controls the speed of the front of the gas injected and determined if the gravitational force dominates or not the process in the recovery of oil. Natural gas had better performance than CO2 and that the presence of aquifer in the reservoir was less influential in the process. In economic analysis found that by injecting natural gas is obtained more economically beneficial than CO2

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The city of Natal-RN is constructed on dune areas with wavy relives softly waved and green areas that help to keep a pleasant climate, amongst these is distinguished field Pirangi-Potengi the dune with the areas of San Vale and Lagoinha. These environments are being substituted gradual for property and other workmanships of engineering on behalf of the urban expansion. This study the elaboration of a geoambiental mapping of Field had as objective generality Pirangi-Potengi the Dune with emphasis the San Vale and Lagoinha in Natal-RN. The done mapping had as objective specific to elaborate a vegetation map, a map of registers in cadastre of ambient problems to dunes, a map of flooding susceptibility, a map of vulnerability to the underground water contamination and a map of use and occupation of the ground. Of the carried through analysis, the area in study reveals sufficiently degraded, remaining only few green areas and dunares, as well as, the vulnerable presence of areas of vulnerability in floods and areas the contamination of the water-bearing one. The gotten results allow to affirm that this type of mapping, is of great importance for analysis and evaluation of the environment of the city

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The study that resulted in this dissertation was developed at OU RNCE PETROBRAS, in Natal, which implemented a project of rational use and reuse of water, including use of wastewater from a Sewage Treatment Plant (STP) already in place, diluted with water from own wells for irrigation of green area of the building complex corporate enterprise. Establish a methodology that can serve as guidelines for future projects controlled reuse of water like this was the objective of this research. Been proposed, implemented and evaluated three instruments of sanitary and environmental control: 1) adaptation of sewage treatment plant and quality control of the treated effluent 2) analysis of soil-nutrient interaction in the irrigated area, 3) knowledge of the local hydrogeology, especially with regard to the direction of flow of the aquifer and location of collection wells of Companhia de Águas e Esgotos do Rio Grande do Norte (CAERN) situated in the surroundings. These instruments have proven sufficient and appropriate to ensure the levels of sanitary and environmental control proposed and studied, which were: a) control of water quality off the STP and the output of the irrigation reservoir, b) control of water quality sub surface soil and assessment of progress on soil composition, c) assessment of water quality in the aquifer. For this, we must: 1) establishing the monitoring plan of the STP and its effluent quality sampling points and defining the parameters of analysis, improve the functioning of that identifying the adequacy of flow and screening as the main factors of operational control, and increase the efficiency of the station to a relatively low cost, using additional filters, 2) propose, implement and adapt simple collectors to assess the quality of water percolating into the soil of the irrigated area, 3) determine the direction of groundwater flow in the area study and select the wells for monitoring of the aquifer.

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The groundwater represents the most important freshwater supply of planet. Dailly, in all world a great amount of toxic and genotoxic material reaches the aquatic systems, mainly the aquifers. The Barreiras aquifer through of five water wells is responsible for the supplying of Universidade Federal do Rio Grande do Norte (UFRN). All water wells are polluted with nitrate and some heavy metals, two of them were disabled. The genotoxicity of groundwater samples from Barreiras Aquifer in UFRN was assessed using the Allium cepa test, the Ames test and the Salmonella typhymurium microsuspension test (Kado test). For the Allium cepa test the influence of the groundwater samples collected on macroscopic (root length, colour and form) and microscopic (root tip mitotic index, chromosome aberrations and micronucleus) parameters was examined. All water samples caused a significant increase of the chromosome and mitotic aberration frequency and reduction on the rooth growth compared to negative control. Bridges and chromosome stickness were the most frequent kind of aberration in dividing cells. Furthermore, breaks were also observed. No significant increase in the number of micronuclei was found in relation to the negative controls. For Ames test were used the Salmonella typhymurium strains TA98 and TA100 without metabolic activation, applying the direct method. Prior to the Kado test, organic fractions from the water samples were obtained through XAD resin concentration. The mutagenicity organic extracts were evaluated by Kado test using TA98 and TA100 strains, in the absence and presence of S9 mix (metabolic activation). The concentrations of seven heavy metal ions were measured in water samples, but only Ni, Cu and Cr levels exceeded the permissible maximum concentration for the natural reservoirs. The results obtained for mutagenic activity using the Ames test were negative in all raw water samples analyzed. Positive results in XAD4 extracts of water samples were obtained for TA98 in the presence of S9 mix for two stations. Concentrations of heavy metals and nitrate can be correlated with the toxicity and genotoxicity of water analyzed. The mutagenic effect detected with TA98 strain suggested that organic compounds (after metabolization) are involved with the mutagenicity detected in the samples analyzed. The data set obtained in this work indicated the presence of at least two classes of mutagens: organic and inorganic compounds

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior

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A research project is being developed by PPGG/UFRN and PETROBRAS in the Xaréu Oil Field located in Ceará Basin, Northeastern Brazil. The objective of the research is to characterize a fractured carbonate reservoir, the Trairi Limestone, in order to drill a borehole with two horizontal legs taking advantage of the natural fracture system to enhance the oil recovery. The present master thesis is part of this research and its contribution is to estimate fault orientation from unoriented cores, using the method proposed by Hesthammer & Henden (2000). In order to orient a fault cutting a bed observed in the core, the bed should be previously oriented. As additional constraint to orient the bed, we use regional bedding orientation obtained from structure maps of Trairi Limestone. Because the number of cores drilled from the Trairi Limestone was too small, we analyzed all cores from the field. As geologic constraint, we admit that all faults were formed as result of the South America and Africa separation, in the context of a regional dextral strike-slip fault formation. In this context, secondary faults are manly T and R faults according Riedel s classification. We analyzed 236.5 m of cores. The dip of bedding varies from 0o to 8o, being the most frequent value equal to 2o. We interpret this result as evidence that the deformation process was manly ruptil. 77 faults were identified in the cores. These faults strike manly to NW and NE with dips, in general, inside the interval 700 - 900. We suggest that the horizontal legs of the borehole should be oriented to NW and NE in order to improve the probability of intercepting open fractures and faults

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This work aims to analyze socio-environmental vulnerability in the Zone of Environmental Preservation -9, located in the northern of the city of Natal / RN. This objective was outlined when we noted a large number of households (about 2000) located in an area considered relevant in terms of environmental and social conditions, notably because of the existence of lakes, sand dunes and rivers that contribute to groundwater recharge Dunas/Barreiras Furthermore, this area is widely used for agricultural activities. The methodology used during this research is accorded to the literature review about the concept of vulnerability, consultations in public agencies for data acquisition, field research and questionnaires. Data collected from each category of vulnerability (social and environmental) were tabulated, analyzed and presented as tables, maps and texts. According to theoretical concepts and methodology of Alves (2006), Cutter (1996), Torres (2000), Acselrad (2006) e Hogan e Marandola Junior (2005; 2006; 2007), the research is structured in the preparation of an environmental diagnosis of the neighborhoods of Blue Lagoon and Pajuçara and subsequent analysis of socio-environmental vulnerability in the Zone of Environmental Preservation -9, especially Area 1, 2 and 3.There was a variation in results between the social vulnerability and environmental vulnerability categories for each area of the Zone of Environmental Preservation -9. However, the crossing between the two categories above showed that Area 3 had the highest level of environmental vulnerability, followed by Area 1. On the other hand, the Area 2 was considered of minor environmental vulnerability. In this sense, this work presents relevant subsidies to the planning of public policies, to identify and characterize the critical areas with high socio-environmental vulnerability

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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Foi estudada a anatomia foliar de Tillandsia crocata (E. Morren) Baker, T. gardneri Lindl., T. geminiflora Brongn., T. linearis Vell., T. lorentziana Griseb., T. mallemontii Glaziou ex Mez, T. recurvata L., T. streptocarpa Baker, T. stricta Soland ex Sims, T. tenuifolia L. T. usneoides L. e Tillandsia sp., dos Campos Gerais, Paraná, Brasil. em vista frontal a epiderme apresenta células com paredes lineares até sinuosas, corpos silicosos e escamas epidérmicas que protegem os estômatos anomocíticos. A epiderme e o primeiro estrato da hipoderme apresentam células lignificadas na maioria das espécies. em secção transversal observa-se estômatos que ocorrem um pouco abaixo do nível das demais células da epiderme; presença de parênquima aqüífero; canais de ar longitudinais e feixes vasculares colaterais circundados por bainha dupla. Essas estruturas anatômicas são xeromórficas e usualmente consideradas como adaptações ao hábito epifítico das Tillandsia atmosféricas. Além disso, elas poderiam também ser usadas com finalidades diagnósticas para as espécies. Forma do limbo da folha em secção transversal, ornamentação da cutícula, estrutura das escamas epidérmicas, espessamento das paredes das células epidérmicas, distribuição dos estômatos, estrutura e distribuição das células do parênquima aqüífero, presença de canais de ar e tamanho de feixes vasculares são caracteres que podem auxiliar na delimitação taxonômica das espécies dentro do gênero.

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Estudou-se a anatomia de escapos, folhas e brácteas de 24 espécimes de Syngonanthus sect. Eulepis, que ocorrem nos campos rupestres do Brasil. Os escapos apresentam número variado de costelas, epiderme unisseriada, com células de paredes totalmente espessadas; córtex com esclerênquima e parênquima clorofiliano alternados; endoderme contínua ou descontínua; periciclo estrelado; feixes vasculares colaterais; medula com células de paredes finas ou espessadas. As folhas e as brácteas apresentam epiderme com células de paredes total ou parcialmente espessadas, estômatos na face abaxial, margem com parênquima clorofiliano ou esclerênquima; mesofilo com hipoderme constituída de esclerênquima ou parênquima aqüífero, feixes vasculares colaterais envolvidos externamente pela endoderme e internamente pelo periciclo. Escapos, folhas e brácteas de Syngonanthus sect. Eulepis apresentam células com paredes espessadas e grande quantidade de esclerênquima, provavelmente como resposta adaptativa dessas plantas ao vento e à radiação excessiva comum nos campos rupestres. Epiderme com células de paredes espessadas, estômatos com câmara subestomática não especializada, presença de hipoderme, esclerênquima, e parênquima clorofiliano compacto, caracterizam anatomicamente escapos, folhas e brácteas de Syngonanthus sect. Eulepis. No geral, os caracteres anatômicos não são consistentes para separar os táxons dentro da seção.

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

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O cisto nasolabial é classificado como um cisto fissural, localizado externamente ao tecido ósseo, na região correspondente ao sulco nasolabial e asa do nariz. Estes cistos são freqüentemente assintomáticos e geralmente promovem a elevação da asa do nariz. Apesar da sua difícil ocorrência, é importante reconhecermos as características desta lesão. O objetivo deste artigo é o de revisar a literatura e de discutir aspectos histológicos e etiológicos desta condição, bem como o tratamento por meio da excisão cirúrgica.