955 resultados para Perda de Dente
Resumo:
GURGEL, Bruno Cesar de vasconcelos.Influencia do meloxicam sobre a perda ossea alveolar em periodontite experimental: avaliaçao histometrica em ratos. 2003.97f. Dissertaçao (Mestrado) - Universidade Estadual de Campinas. Faculdade de Odontologia de Piracicaba. Piracicaba, 2003. Disponivel em:
Resumo:
The materials engineering includes processes and products involving several areas of engineering, allowing them to prepare materials that fulfill the needs of various new products. In this case, this work aims to study a system composed of cement paste and geopolymers, which can contribute to solving an engineering problem that directly involves the exploitation of oil wells subject to loss of circulation. To correct it, has been already proposed the use of granular materials, fibers, reducing the drilling fluid or cement paste density and even surface and downhole mixed systems. In this work, we proposed the development of a slurry mixed system, the first was a cement-based slurry and the second a geopolymer-based slurry. The cement-based slurry was formulated with low density and extenders, 12.0 ppg (1.438 g/cm ³), showing great thixotropic characteristics. It was added nano silica at concentrations of 0.5, 1.0 and 1.5 gps (66.88, 133.76 and 200.64 L/m3) and CaCl2 at concentrations of 0.5, 1, 0 and 1.5%. The second system is a geopolymer-based paste formulated from molar ratios of 3.5 (nSiO2/nAl2O3), 0.27 (nK2O/nSiO2), 1.07 (nK2O/nAl2O3) and 13.99 (nH2O/nK2O). Finally, we performed a mixture of these two systems, for their application for correction of circulation lost. To characterize the raw materials, XRD, XRF, FTIR analysis and titration were performed. The both systems were characterized in tests based on API RP10B. Compressive strength tests were conducted after curing for 24 hours, 7 and 28 days at 58 °C on the cement-based system and the geopolymer-based system. From the mixtures have been performed mixability tests and micro structural characterizations (XRD, SEM and TG). The results showed that the nano silica, when combined with CaCl2 modified the rheological properties of the cement slurry and from the concentration of 1.5 gpc (200.64 L / m³) it was possible to obtain stable systems. The system mixture caused a change in the microstructure of the material by favoring the rate of geopolymer formation to hinder the C3S phase hydration, thus, the production of CSH phases and Portlandite were harmed. Through the mixability tests it can be concluded that the system, due to reduced setting time of the mixture, can be applied to plug lost circulation zones when mixed downhole
Resumo:
Waterflooding is a technique largely applied in the oil industry. The injected water displaces oil to the producer wells and avoid reservoir pressure decline. However, suspended particles in the injected water may cause plugging of pore throats causing formation damage (permeability reduction) and injectivity decline during waterflooding. When injectivity decline occurs it is necessary to increase the injection pressure in order to maintain water flow injection. Therefore, a reliable prediction of injectivity decline is essential in waterflooding projects. In this dissertation, a simulator based on the traditional porous medium filtration model (including deep bed filtration and external filter cake formation) was developed and applied to predict injectivity decline in perforated wells (this prediction was made from history data). Experimental modeling and injectivity decline in open-hole wells is also discussed. The injectivity of modeling showed good agreement with field data, which can be used to support plan stimulation injection wells
Resumo:
The oil companies in the area in general are looking for new technologies that can increase the recovery factor of oil contained in reservoirs. These investments are mainly aimed at reducing the costs of projects which are high. Steam injection is one of these special methods of recovery in which steam is injected into the reservoir in order to reduce the viscosity of the oil and make it more mobile. The process assisted gravity drainage steam (SAGD) using steam injection in its mechanism, as well as two parallel horizontal wells. In this process steam is injected through the horizontal injection well, then a vapor chamber is formed by heating the oil in the reservoir and, by the action of gravitational forces, this oil is drained down to where the production well. This study aims to analyze the influence of pressure drop and heat along the injection well in the SAGD process. Numerical simulations were performed using the thermal simulator STARS of CMG (Computer Modeling Group). The parameters studied were the thermal conductivity of the formation, the flow of steam injection, the inner diameter of the column, the steam quality and temperature. A factorial design was used to verify the influence of the parameters studied in the recovery factor. We also analyzed different injection flow rates for the model with pressure drop and no pressure drop, as well as different maximum flow rates of oil production. Finally, we performed an economic analysis of the two models in order to check the profitability of the projects studied. The results showed that the pressure drop in injection well have a significant influence on the SAGD process.
Resumo:
Injectivity decline, which can be caused by particle retention, generally occurs during water injection or reinjection in oil fields. Several mechanisms, including straining, are responsible for particle retention and pore blocking causing formation damage and injectivity decline. Predicting formation damage and injectivity decline is essential in waterflooding projects. The Classic Model (CM), which incorporates filtration coefficients and formation damage functions, has been widely used to predict injectivity decline. However, various authors have reported significant discrepancies between Classical Model and experimental results, motivating the development of deep bed filtration models considering multiple particle retention mechanisms (Santos & Barros, 2010; SBM). In this dissertation, inverse problem solution was studied and a software for experimental data treatment was developed. Finally, experimental data were fitted using both the CM and SBM. The results showed that, depending on the formation damage function, the predictions for injectivity decline using CM and SBM models can be significantly different
Resumo:
Nowadays, most of the hydrocarbon reserves in the world are in the form of heavy oil, ultra - heavy or bitumen. For the extraction and production of this resource is required to implement new technologies. One of the promising processes for the recovery of this oil is the Expanding Solvent Steam Assisted Gravity Drainage (ES-SAGD) which uses two parallel horizontal wells, where the injection well is situated vertically above the production well. The completion of the process occurs upon injection of a hydrocarbon additive at low concentration in conjunction with steam. The steam adds heat to reduce the viscosity of the oil and solvent aids in reducing the interfacial tension between oil/ solvent. The main force acting in this process is the gravitational and the heat transfer takes place by conduction, convection and latent heat of steam. In this study was used the discretized wellbore model, where the well is discretized in the same way that the reservoir and each section of the well treated as a block of grid, with interblock connection with the reservoir. This study aims to analyze the influence of the pressure drop and heat along the injection well in the ES-SAGD process. The model used for the study is a homogeneous reservoir, semi synthetic with characteristics of the Brazilian Northeast and numerical simulations were performed using the STARS thermal simulator from CMG (Computer Modelling Group). The operational parameters analyzed were: percentage of solvent injected, the flow of steam injection, vertical distance between the wells and steam quality. All of them were significant in oil recovery factor positively influencing this. The results showed that, for all cases analyzed, the model considers the pressure drop has cumulative production of oil below its respective model that disregards such loss. This difference is more pronounced the lower the value of the flow of steam injection
Resumo:
Stress urinary incontinence (SUI) is defined as "involuntary loss of urine" due to several processes that alter the ability of the bladder to hold urine properly, regarded as a social and hygienic problem that adversely affects quality of life. In postmenopausal women, IU is associated with atrophy and weakness of the pelvic floor muscles. The objective this study was investigate, using the onehour pad test, stress urinary leakage (SUI), evaluate and compare their results in postmenopausal and premenopausal women. The survey was characterized as a cross-sectional study. The study consisted of 60 postmenopausal women were divided into GIU - consisting of 34 volunteers complaining of involuntary loss of urine during stress - and GSIU - consisting of 26 volunteers without complaints of loss of urine during stress, and 15 women, during the premenopausal (GPM), and ovulatory with normal menstrual cycle. All volunteers were evaluated clinically, subjected to one-hour pad test, after the biochemical evaluation of blood and sex hormones. Statistical analysis was performed by descriptive analysis, ANOVA, Turkey´s post-test and Pearson correlation. The results showed that 100% of postmenopausal patients had involuntary loss of urine during one hour pad test (GIU: 4.0 g; GSIU: 4.5 g). GPM remained continent after an hour pad test (GPM: 0.4 g). In addition, Pearson showed a strong correlation between urine loss with time since menopause (r = 0.8, p <0.01) and body mass index - BMI (r = 0.7; p = 0.01). These data suggest that the one-hour pad test is a useful test to assess and quantify urinary leakage, including those volunteers who had no previous complaint of SUI
Resumo:
Introdução: A obesidade e suas formas extremas como a forma mórbida, vem assumindo preocupação nos sistemas de saúde pública e é atualmente considerado um dos mais importantes agravos de saúde no mundo desenvolvido. Acarreta repercussões em várias partes do corpo, com potencial para interferir negativamente também na função reprodutiva, recentemente sendo mais estudado na população masculina. Objetivo: avaliar parâmetros hormonais e seminais da função reprodutiva em um grupo de homens obesos mórbidos, antes e após 6 meses da perda de peso induzida pela cirurgia bariátrica. Métodos: Inicialmente, de uma amostra de 36 pacientes com idade entre 18 e 40 anos e índice de massa corporal (IMC) ≥40 Kg/m2, apenas 1 caso foi excluído por ser portador de hiperprolactinoma e outros 24 pacientes não completaram todo o protocolo de avaliação laboratorial solicitada. Um total de apenas 11 pacientes completou o protocolo. Todos foram previamente avaliados por uma equipe multidisciplinar. O grupo selecionado foi submetido a avaliação seminal e dosagens hormonais de testosterona total(TT), FSH e LH. Os parâmetros foram reavaliados após 6 meses de realização da cirurgia pela técnica de Y-em-Roux, para análise dos efeitos da perda de peso sobre os parâmetros da função reprodutiva. Resultados: No grupo selecionado ao estudo, os exames pré-operatórios mostraram um grupo heterogêneo de resultados. Após seis meses do tratamento cirúrgico, a perda ponderal foi significativa no grupo analisado, com redução do IMC de mediana 46 Kg/m2para mediana de 36 Kg/m2(p=0,03). Em relação ao perfil hormonal, houve elevação significativa do nível sérico de TT com mediana de 187ng/ml no período pré-operatório para 457 ng/ml (p=0,02) no período pós-operatório. Entre os períodos pré e pós-operatório, não foram observadas alterações significantes do FSH (2,70 mIU/ml para 3,31 mIU/ml, p=0,79), LH (4,82 mIU/ml para 3,00mIU/ml, p=0,39), concentração espermática (38milhões/ml para 31milhões/ml, p=0,88) e motilidade A+B (50% para 50%, p=0,89).Conclusão: A redução ponderal decorrente da cirurgia em obesos mórbidos parece levar a uma elevação dos níveis de testosterona total, sem alterações nas demais provas de avaliação reprodutiva. Estudos adicionais com casuística maior e múltiplos parâmetros são necessários para esclarecimento definitivo do impacto da obesidade e da perda de peso induzida pela cirurgia sobre a função reprodutiva masculina
Resumo:
O objetivo deste trabalho foi avaliar a perda de solo de área de nascentes da Microbacia do Córrego do Tijuco, SP. Foi utilizada a análise espacial dos fatores da equação universal da perda de solo (EUPS), em integração com análise de componentes principais e geoestatística. A perda de solo média, estimada para a área, foi de 118,5 Mg ha‑1 por ano, considerada alta. Próximo à zona urbana, houve alta interação dos fatores erosividade da chuva e práticas conservacionistas, o que evidencia grande perda de solo, em razão da concentração da água proveniente da camada impermeabilizada urbana, com alta velocidade de escoamento. Nos divisores de águas, a atuação da erodibilidade foi proeminente, em contraste com o fator topográfico. Foram observadas áreas com atuação conjunta destes fatores, inclusive em locais de inclinação suave, porém com alto potencial natural de erosão. A interação das análises multivariadas e geoestatística permite a estratificação da área, identifica locais com propriedades específicas quanto à perda de solo, e espacializa os fatores do processo erosivo e suas interações ao longo do relevo.
Resumo:
High levels of local, regional, and global extinctions has progressively simplified communities in terms of both species and ecosystem functioning. Theoretical models demonstrated that the degree of functional redundancy determines the rates of functional group loss in response to species extinctions. Here, we improve the theoretical predictions by incorporating in the model interactions between species and between functional groups. In this study, we tested the effect of different scenarios of interspecific interactions and effects between functional groups on the resistance to loss of community functional groups. Virtual communities have been built with different distribution patterns of species in functional groups, both with high and low evenness. A matrix A was created to represent the net effect of interspecific interactions among all species, representing nesting patterns, modularity, sensitive species, and dominant species. Moreover, a second matrix B was created to represent the interactions between functional groups, also exhibiting different patterns. The extinction probability of each species was calculated based on community species richness and by the intensity of the interspecific interactions that act upon it and group to which it belongs. In the model, successive extinctions decrease the community species richness, the degree of functional redundancy and, consequently, the number of functional groups that remain in the system. For each scenario of functional redundancy, A, and B, we ran 1000 simulations to generate an average functional extinction curve. Different model assumptions were able to generate remarkable variation on functional extinction curves. More extreme variations occurred when the matrix A and B caused a higher heterogeneity in the species extinction probability. Scenarios with sensitive species, positive or negative, showed a greater variation than the scenarios with dominant species. Nested interactions showed greater variation than scenarios where the interactions were in modules. Communities with maximal functional evenness can only be destabilized by the interactions between species and functional groups. In contrast, communities with low functional evenness can have its resistance either increased or decreased by the interactions. The concentration of positive interactions in low redundancy groups or negative interactions in high redundancy groups was able to decrease the functional extinction rates. In contrast, the concentration of negative interactions in low redundancy groups or positive interactions in high redundancy groups was able to increase the functional extinction rates. This model shows results that are relevant for species priorization in ecosystem conservation and restoration
Resumo:
O objetivo do presente estudo foi avaliar se a forma física da ração (farelada e peletizada) afeta a porosidade e espessura da casca, e porcentagem de perda de água e eclodibilidade de ovos de perdiz. Os ovos foram coletados logo após a postura e separados em diferentes intervalos de peso (35-45g, 46-50g, 51-55g, 56-60g e 61-70g), sendo 10 ovos/classe/ração. O número de poros das cascas foi avaliado nas regiões apical, equatorial e basal dos ovos. Utilizou-se um micrômetro digital para a mensuração da espessura das três regiões da casca dos ovos, a partir dos quais obteve-se a espessura média por ovo. Os ovos para avaliação da eclodibilidade e porcentagem de perda de água do ovo até a transferência para o nascedouro (16º dia) foram pesados, desinfectados, incubados (T=35,5ºC e UR= 70%) e transferidos no 16º dia de incubação para o nascedouro, onde foram mantidos até a eclosão. As análises estatísticas empregadas foram: Análise de Variância e de Correlação, e teste de Tukey 5%. Os dados mostraram que, em perdizes, o número de poros na casca pode variar com a região da casca, peso do ovo e a forma física da ração, e que a ingestão de ração peletizada promove um aumento na espessura da casca dos ovos sem alterar a eclodibilidade e a porcentagem de perda de água dos mesmos durante a incubação.
Resumo:
O objetivo deste trabalho foi estudar a influência das superfícies geomórficas na variação espacial da perda de solo por erosão na região de Pereira Barreto, São Paulo (SP). Os solos foram amostrados nos pontos de cruzamento de uma malha, georreferenciados, com intervalos de 350m, na profundidade de 0,0-0,2m, totalizando 67 pontos. Foram feitas determinações da composição granulométrica e do conteúdo de matéria orgânica. Foram avaliados os fatores de erosão locais, tais como erosividade (R), erodibilidade (K), fator topográfico (LS), uso e manejo (C), práticas conservacionistas (P), potencial natural de erosão (PNE), perda de solo com e sem práticas conservacionistas (A e *A), tolerância de perda de solo (T) e risco de erosão (RE). As variáveis A, PNE e RE apresentaram forte correlação espacial com o fator topográfico (LS), indicando a forte relação do relevo sobre os fatores de erosão. As perdas de solo (A e *A) apresentaram comportamento coerente com a conceituação de superfícies geomórficas, evidenciando as relações de dependência do processo erosivo do solo aos ambientes geomórficos.
Resumo:
A perda de calor por evaporação cutânea e as características morfológicas do pelame (espessura da capa, comprimento médio dos pêlos, número de pêlos por unidade de área e diâmetro médio dos pêlos) foram avaliadas em 254 cabras das raças Saanen, Alpina e mestiças ½ Boer ½ Saanen. Utilizou-se uma cápsula ventilada para medir a evaporação cutânea, determinada em três regiões do corpo (próximo ao pescoço, meio do flanco e quarto traseiro), enquanto as características morfológicas do pelame foram avaliadas a partir de amostras de pêlos, tomadas 18 cm abaixo da coluna vertebral, exceto a espessura da capa, que foi medida in situ. Os resultados indicaram que os animais apresentam pelame pouco denso, formado por pêlos finos e compridos. Animais mestiços (½ Bôer ½ Saanen) apresentaram taxas de evaporação cutânea mais elevadas que os puros das raças Saanen e Alpina.
Resumo:
In this dissertation new models of propagation path loss predictions are proposed by from techniques of optimization recent and measures of power levels for the urban and suburban areas of Natal, city of Brazilian northeast. These new proposed models are: (i) a statistical model that was implemented based in the addition of second-order statistics for the power and the altimetry of the relief in model of linear losses; (ii) a artificial neural networks model used the training of the algorithm backpropagation, in order to get the equation of propagation losses; (iii) a model based on the technique of the random walker, that considers the random of the absorption and the chaos of the environment and than its unknown parameters for the equation of propagation losses are determined through of a neural network. The digitalization of the relief for the urban and suburban areas of Natal were carried through of the development of specific computational programs and had been used available maps in the Statistics and Geography Brazilian Institute. The validations of the proposed propagation models had been carried through comparisons with measures and propagation classic models, and numerical good agreements were observed. These new considered models could be applied to any urban and suburban scenes with characteristic similar architectural to the city of Natal
Resumo:
The telecommunications industry has experienced recent changes, due to increasing quest for access to digital services for data, video and multimedia, especially using the mobile phone networks. Recently in Brazil, mobile operators are upgrading their networks to third generations systems (3G) providing to users broadband services such as video conferencing, Internet, digital TV and more. These new networks that provides mobility and high data rates has allowed the development of new market concepts. Currently the market is focused on the expansion of WiMAX technology, which is gaining increasingly the market for mobile voice and data. In Brazil, the commercial interest for this technology appears to the first award of licenses in the 3.5 GHz band. In February 2003 ANATEL held the 003/2002/SPV-ANATEL bidding, where it offered blocks of frequencies in the range of 3.5 GHz. The enterprises who purchased blocks of frequency were: Embratel, Brazil Telecom (Vant), Grupo Sinos, Neovia and WKVE, each one with operations spread in some regions of Brazil. For this and other wireless communications systems are implemented effectively, many efforts have been invested in attempts to developing simulation methods for coverage prediction that is close to reality as much as possible so that they may become believers and indispensable tools to design wireless communications systems. In this work wasm developed a genetic algorithm (GA's) that is able to optimize the models for predicting propagation loss at applicable frequency range of 3.5 GHz, thus enabling an estimate of the signal closer to reality to avoid significant errors in planning and implementation a system of wireless communication