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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Din?mica de Sedimenta??o de Lodo em Lagoas de Estabiliza??o / Sludge Sedimentation Dynamics in Stabilization Ponds

Saraiva, Libertalamar Bilhalva 01 June 2007 (has links)
Made available in DSpace on 2014-12-17T15:01:43Z (GMT). No. of bitstreams: 1 LibertalamarBS.pdf: 1245835 bytes, checksum: e50b7694a4b730a50be93e5d2ce30412 (MD5) Previous issue date: 2007-06-01 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / Stabilization ponds are an effective sewage treatment alternative for the climatic conditions prevailing in Brazil. In the present work, a primary facultative pond was studied, in the city of Natal, Rio Grande do Norte, Northeast Brazil. The aim of this study was to evaluate the sedimentation dynamics in the facultative pond. The pond was divided in three section or zones along its length starting from the inlet end namely A1, A2 and A3. The research was accomplished in three phases. In the first the mapping of the sludge layer was done, sludge core samples were also collected for analysis for total, fixed and volatile solids and the depth of the sludge layer was determined using a portable echo sounder. In the second solids sedimentation rates were measured using traps placed in the inlet and outlet zones and in the third phase resuspension sludge was evaluate using a tracer. The amount accumulated sludge since the start operation was 13.583 m3. The sedimentation constant averages changed between 0.93 to 2.94 and 3.90 to 5.80 for the depths of 0.5 and 1.0 m respectively. The relationship between volatile and fixed solids (SV/SF) increased along the pond. The removal efficiencies were 52.12%, 36.09%, and 37.50% for BOD, COD and SS, respectively. The sludge accumulation model proposed had a good adjustment with 0.17 m3/hab.year rate. The results presented here demonstrated that the wind had a direct influence on the sedimentation of solids in this pond affecting the efficiency and sludge accumulation / As lagoas de estabiliza??o s?o alternativas vi?veis para o tratamento de esgoto no Brasil, pelas condi??es clim?ticas. Neste trabalho foi estudada uma lagoa facultativa prim?ria, na cidade do Natal, estado do Rio Grande do Norte. O objetivo do estudo foi avaliar a din?mica de sedimenta??o. A lagoa foi dividida em tr?s se??es ao longo de sua extens?o denominadas A1, A2 e A3 e o estudo foi dividido em tr?s fases. Na primeira foram feitos o mapeamento da camada de lodo, caracteriza??o do lodo e a determina??o da espessura por batimetria. Na segunda, a taxa de sedimenta??o de s?lidos foi determinada usando armadilhas suspensas verticalmente na coluna de ?gua a 50 cm e 100 cm de profundidade. Na terceira fase a re-suspens?o dos s?lidos foi verificada com tra?ador em 10% do volume da lagoa. Amostras de afluente e efluente foram coletadas para an?lise de pH, DBO, DQO e s?lidos suspensos. O volume de lodo acumulado desde o come?o da opera??o do sistema, foi de 13.583 m3. As constantes m?dias de sedimenta??o variaram entre 0,93 a 2,94 e 3,90 a 5,80 para as profundidades de 0,5 e 1 m, respectivamente. A rela??o entre s?lidos vol?teis e fixos (SV/SF) na camada de lodo aumentou ao longo da lagoa. As efici?ncias de remo??o foram de 52,09 %, 36,12%, 37,50 % para DBO, DQO e SST, respectivamente. A taxa de ac?mulo de lodo foi estimada em 0,17 m3. hab-1.ano-1 e o modelo matem?tico proposto conseguiu estimar de forma satisfat?ria o volume de lodo depositado. Os resultados mostram que a dire??o e a velocidade do vento tem uma influ?ncia direta na sedimenta??o dos s?lidos nesta lagoa afetando a efici?ncia e o ac?mulo de lodo
2

Modelagem matem?tica e simula??o num?rica de correntes de gravidade em uma configura??o canal-bacia

Francisco, Ezequiel Pelisoli 12 March 2018 (has links)
Submitted by PPG Engenharia e Tecnologia de Materiais (engenharia.pg.materiais@pucrs.br) on 2018-03-16T11:45:41Z No. of bitstreams: 1 Tese_Ezequiel_Pelisoli_Francisco.pdf: 24416873 bytes, checksum: 61b6a5e0625a49b1bb008d8f6023eb15 (MD5) / Approved for entry into archive by Tatiana Lopes (tatiana.lopes@pucrs.br) on 2018-04-03T11:57:18Z (GMT) No. of bitstreams: 1 Tese_Ezequiel_Pelisoli_Francisco.pdf: 24416873 bytes, checksum: 61b6a5e0625a49b1bb008d8f6023eb15 (MD5) / Made available in DSpace on 2018-04-03T12:03:22Z (GMT). No. of bitstreams: 1 Tese_Ezequiel_Pelisoli_Francisco.pdf: 24416873 bytes, checksum: 61b6a5e0625a49b1bb008d8f6023eb15 (MD5) Previous issue date: 2018-03-12 / Gravity currents are flows generated by the pressure gradient due density differences between two fluids which are in contact. In this work are presented a set of three-dimensional highly resolved direct numerical simulations of particle-laden gravity currents, solved in an original configuration called channel-basin. The focus is on low concentrations gravity currents, where the density differences are small enough for the Boussinesq approximation may be valid. The mathematical model is based on an Eulerian description of the concentration field by using a transport equation, combined with the incompressible Navier-Stokes equations. The equations are solved by the open-source code Incompact3d, which is based on high-order compact schemes for the concentration and velocity fields discretization, and a spectral method for the pressure field. The adopted mathematical modeling allows the particle sedimentation, however there is no possibility of re-suspension of the particles already deposited, nor the bottom deformation due the growth of the sediment layer thikness. The main goal of this reserach is to know how the initial parameters, such as Reynolds number, settling velocity and channel geometry, affect the dynamics of the current spreading. The results have shown that the spreading form is highly dependent of the settling velocity. For the front velocity of the current, the channel geometry and settling velocity are more important when the Reynolds is lower than when it is higher. The sedimentation rate is highly affected by the settling velocity. The increasing of the Reynolds number mainly affects the size of the turbulent structures such as vortex and lobes. The energy budget is strongly dependent of the settling velocity and slightly dependent of the channel geometry and Reynolds number. / Corrente de gravidade s?o escoamentos que ocorrem devido a um gradiente de press?o gerado, exclusivamente, pela diferen?a na massa espec?fica entre dois fluidos que entram em contato. Neste trabalho ? apresentada uma s?rie de resultados tridimensionais de alta fidedignidade, obtidos atrav?s de simula??o num?rica direta em uma configura??o original, aqui denominada de canal-bacia, a qual busca emular a transi??o entre um escoamento confinado para um n?o confinado. O foco deste estudo est? nas correntes de gravidade de baixas concentra??es, onde as diferen?as de densidade sejam pequenas o suficiente para que a aproxima??o de Boussinesq seja v?lida. O modelo matem?tico baseia-se em uma descri??o Euleriana do campo de concentra??es, que usa uma equa??o de transporte combinada com as equa??es de Navier-Stokes em sua forma incompress?vel. A resolu??o das equa??es ? feita atrav?s do c?digo Incompact3d, o qual baseia-se em esquemas compactos de diferen?as finitas de alta ordem para a solu??o da concentra??o e velocidade, e um m?todo espectral para a solu??o da press?o. O modelo matem?tico adotado permite que as part?culas se depositem no fundo do dom?nio, por?m n?o permite que haja a ressuspens?o nem que o fundo se deforme pelo aumento da espessura da camada de sedimentos. O objetivo proposto nesta Tese ? investigar como os par?metros iniciais, tais como n?mero de Reynolds, velocidade de queda e a geometria do canal de alimenta??o afetam a din?mica de livre espalhamento de correntes conservativas e n?o conservativas. Os resultados mostram que a forma como as correntes se espalham pelo dom?nio ? altamente dependente da velocidade de queda. A velocidade de propaga??o da corrente se mostrou mais dependente da geometria do canal e da velocidade de queda para o menor Reynolds do que para o maior. A taxa de sedimenta??o tamb?m apresentou grande sensibilidade ?s varia??es da velocidade de queda. O aumento no n?mero de Reynolds afetou, principalmente, o tamanho das estruturas turbulentas, tais como v?rtices e lobos. O balan?o de energias ? fortemente dependente da velocidade de queda, sendo pouca a influ?ncia da geometria do canal e do n?mero de Reynolds.
3

Tempo para positivar cultura de bact?rias no l?quido de di?lise peritoneal : avalia??o de diferentes t?cnicas laboratoriais

Katzap, Roberta Monteiro 02 March 2016 (has links)
Submitted by Setor de Tratamento da Informa??o - BC/PUCRS (tede2@pucrs.br) on 2016-05-19T12:54:32Z No. of bitstreams: 1 DIS_ROBERTA_MONTEIRO_KATZAP_COMPLETO.pdf: 1440611 bytes, checksum: 60581bcd966d13bb2ed8592af3528373 (MD5) / Made available in DSpace on 2016-05-19T12:54:32Z (GMT). No. of bitstreams: 1 DIS_ROBERTA_MONTEIRO_KATZAP_COMPLETO.pdf: 1440611 bytes, checksum: 60581bcd966d13bb2ed8592af3528373 (MD5) Previous issue date: 2016-03-02 / Funda??o de Amparo ? Pesquisa do Estado do Rio Grande do Sul - FAPERGS / Chronic kidney disease patients on peritoneal dialysis therapy are susceptible to infections, with peritonitis being the primary cause of technique failure. Peritoneal fluid culture is one of the essential elements for proper diagnosis and treatment of peritonitis. The aim of this study was to compare the time required to obtain a positive culture using different laboratory methods. An in vitro cross-sectional study comparing different laboratory techniques for preparation and culture of bacteria in peritoneal fluid. The research was conducted with 21 sterile dialysis fluid bags with 1.5% glucose concentration, and 21 peritoneal dialysis bags containing peritoneal fluid drained from patients without peritonitis, assisted at the Nephrology Unit from HSL-PUCRS. Fluids from the 42 peritoneal dialysis bags were contaminated by injecting a coagulase-negative Staphylococcus suspension and then prepared for culture using four distinct techniques - A (direct culture), B (post-centrifugation culture), C (direct culture after 4h sedimentation), and D (culture after 4h sedimentation and centrifugation) ? followed by seeding. In the 21 contaminated sterile bags, the mean times to obtain a positive culture with techniques D (19.6 h ?2.6) and C (19.1 h ?2.3) were longer in comparison to A (15.8 h ?3.0; p<0.01), but not statistically different from group B mean (19.0 h ?3.2). The same occurred in the 21 bags drained from patients, with mean times for techniques D (14.0 h ?1.9) and C (14.5 h ?1.7) being longer than technique A (12.22 h ?1.94; p<0.05), however not statistically different from technique B (13.2 h ?1.3). The sedimentation and centrifugation steps were unnecessary and may delay antibiotics sensitivity test result by approximately 8 hours. / Pacientes com doen?a renal cr?nica que realizam terapia de di?lise peritoneal est?o suscet?veis a infec??es, sendo peritonite a principal causa de fal?ncia do m?todo. A cultura do l?quido peritoneal ? um dos elementos essenciais para o manejo cl?nico e tratamento adequados da peritonite. O objetivo deste estudo foi comparar o tempo necess?rio para obter uma cultura positiva, com diferentes m?todos laboratoriais. Estudo transversal, in vitro, comparando diferentes t?cnicas laboratoriais de preparo e cultura para bact?rias em l?quido peritoneal. O estudo foi feito com 21 bolsas de l?quido de di?lise peritoneal est?reis, com concentra??o de 1,5% de glicose, e em 21 bolsas contendo l?quido peritoneal drenado de pacientes sem peritonite, atendidos pelo Servi?o de Nefrologia do HSL-PUCRS. O dialisado das 42 bolsas de di?lise peritoneal foi contaminado, injetando-se suspens?o de Staphylococcus coagulase negativa e, em seguida, submetido a quatro t?cnicas distintas ? A (cultura direta); B (cultura p?s-centrifuga??o); C (cultura ap?s sedimenta??o de 4 h); e D (cultura ap?s sedimenta??o de 4 h e centrifuga??o) ? de preparo e semeadura. Nas 21 bolsas est?reis contaminadas se verificou que as m?dias de tempo para positivar a cultura nas t?cnicas D (19,6 h ?2,6) e C (19,1 h ?2,3) foram maiores, comparadas ? A (15,8 h ?3,0; p<0,01), mas estatisticamente n?o diferentes da m?dia do grupo B (19,0 h ?3,2). O mesmo aconteceu nas 21 bolsas drenadas dos pacientes, com tempos m?dios para as t?cnicas D (14,0 h ?1,9) e C (14,5 h ?1,7) superiores ao tempo da t?cnica A (12,22 h ?1,94; p<0,05), por?m n?o estatisticamente diferente da t?cnica B (13,2 h ?1,3). As etapas de sedimenta??o e centrifuga??o foram desnecess?rias, podendo postergar em quase oito horas o resultado final da cultura, comparativamente ? cultura direta, atrasando o resultado do teste de sensibilidade aos antibi?ticos.
4

Modelagem e simula??o da sedimenta??o de s?lidos adensantes em fluidos de perfura??o / Modeling and simulation of sedimentation of adsorptive solids in drilling fluids

RIBEIRO JUNIOR, Jos? Messias 30 August 2016 (has links)
Submitted by Jorge Silva (jorgelmsilva@ufrrj.br) on 2017-02-13T18:29:35Z No. of bitstreams: 1 2016 - Jos? Messias Ribeiro J?nior.pdf: 2014751 bytes, checksum: f6fdac1f2a0f681e038143bedfe908ed (MD5) / Made available in DSpace on 2017-02-13T18:29:35Z (GMT). No. of bitstreams: 1 2016 - Jos? Messias Ribeiro J?nior.pdf: 2014751 bytes, checksum: f6fdac1f2a0f681e038143bedfe908ed (MD5) Previous issue date: 2016-08-30 / CENPES / Petrobras / This work has aimed to evaluate the predictive ability of simplified mathematical models to describe the dynamics of the thickening of solids in drilling fluids. In the early stages, settling experiments of barite and calcite in water-based fluids at graduated cylinders were done at initial volumetric concentrations of 6.7%, 12% and 20%, while the change of interface height was measured on the time steps. The first data modelling approach has used conservation laws, considering the relative velocity between the solid and the liquid phase as function of volumetric concentration of solids. This way, the conservation laws used to simulate these systems were based in mass conservation law and in the flux density functions. For the accuracy evaluation in the numerical data provided by conservation laws, this work has used the interface height variation through a period of time, which was determined by experiments as an auxiliary variable, to imply the prediction quality provided by the proposed model, because there was not any equipment available to determine the spatial profiles of solids concentration. Through this procedure, it was found that conservation laws was capable of predict the interface variation through a period of time with relative errors below 10%, except in regions of rapid increase of local concentration. In the second approach of modelling was used a simplified model consisting of the continuity equation and the momentum equation, considering the interaction forces between the solid and liquid phases. The simplified model describe the variation of the interface height through a period of time in several sedimentations, and the displayed results were quite satisfactory and with relative errors lower than the results showed by the conservation laws. In the final stage of this work, the simplified model was used in the simulation of time and spatial concentration profile of the barite suspended in the BR-Mul fluid, which is a real drilling fluid often used by Petrobras. The concentration profiles obtained by simulation were compared with the experimental data reported by authors from Faculty of Chemical Engineering in Federal University of Uberlandia (FEQ/UFU). In this case study, it was possible to directly compare the model output with the experimental data, and the results has showed that the relative error of the model was lower to the fluid with the highest concentration suspensions of barite, specially in the points near to the compacted zone. However, the experimental methodology used in FEQ/UFU has exhibit much imprecision in the regions of high solids concentration, because of the experimental error in the gamma ray emitter. / O presente trabalho teve como objetivo avaliar a capacidade de predi??o de modelos matem?ticos simplificados para descrever a din?mica de sedimenta??o de s?lidos adensantes em fluidos de perfura??o. Na etapa inicial deste trabalho, foram realizados experimentos de sedimenta??o de suspens?es aquosas de barita e de calcita em colunas de vidro, com concentra??es volum?tricas iniciais de 6; 7%, 12% e 20% para cada s?lido, e a varia??o da altura da interface entre a zona de clarificado e a zona de concentra??o constante foi registrada ao longo do tempo. A primeira abordagem fez uso de modelos conservativos, cuja velocidade relativa entre o s?lido e o fluido ? somente fun??o da concentra??o volum?trica local do s?lido. Dessa forma, os modelos conservativos utilizados para simular esses sistemas foram baseados nas leis de conserva??o da massa e em fun??es de densidade de fluxo. Para avaliar a acur?cia dos resultados fornecidos pelos modelos conservativos, utilizou-se a varia??o da altura da interface de clarifica??o ao longo do tempo, como vari?vel auxiliar para inferir a qualidade das predi??es fornecidas pelo modelo, visto que n?o se dispunha de equipamentos para determinar os perfis espaciais de concentra??o de s?lidos. Atrav?s deste procedimento, verificou-se que os modelos conservativos foram capazes de predizer a varia??o temporal da interface de clarifica??o com erro relativo menor que 10% na maior parte do tempo, exceto na regi?o que a concentra??o local aumenta rapidamente. Na segunda abordagem utilizou-se um modelo simplificado, composto pela equa??o da continuidade e pela equa??o do movimento, considerando as for?as de intera??o entre as fases s?lido e l?quido. O modelo simplificado descreve a varia??o temporal da interface de clarifica??o dos sistemas de sedimenta??o simples, com valores bastante satisfat?rios e com erro relativo menor do que os resultados exibidos pelos modelos conservativos. Na etapa final deste trabalho, este mesmo modelo foi avaliado na simula??o dos perfis temporais e espaciais da concentra??o de barita na sedimenta??o no fluido BR-Mul, que ? um fluido real de perfura??o bastante utilizado pela Petrobras. Os perfis de concentra??o obtidos por simula??o foram comparados a dados experimentais obtidos na Faculdade de Engenharia Qu?mica da Universidade Federal de Uberl?ndia (FEQ/UFU). Neste estudo de caso, foi poss?vel comparar diretamente a sa?da do modelo aos dados experimentais, e os resultados mostraram que o erro relativo do modelo foi menor para o fluido com a maior concentra??o inicial de barita, sobretudo nos pontos que se encontram pr?ximos da regi?o de compacta??o. No entanto, a metodologia experimental utilizada na FEQ/UFU apresenta elevada imprecis?o em regi?es com alta concentra??o de s?lidos, devido ao erro experimental introduzido na utiliza??o do equipamento emissor de raios gama.
5

An?lise de pluma hiperpicnal poli-dispersa por simula??o num?rica direta / Analisys of hiperpycnal poly-disperse plume by direct numerical simulation

Schuch, Felipe Nornberg 31 March 2016 (has links)
Submitted by Setor de Tratamento da Informa??o - BC/PUCRS (tede2@pucrs.br) on 2016-12-06T16:20:59Z No. of bitstreams: 1 DIS_FELIPE_NORNBERG_SCHUCH_COMPLETO.pdf: 1906760 bytes, checksum: 0cbecd09eb2ec152ab66879b383df442 (MD5) / Made available in DSpace on 2016-12-06T16:20:59Z (GMT). No. of bitstreams: 1 DIS_FELIPE_NORNBERG_SCHUCH_COMPLETO.pdf: 1906760 bytes, checksum: 0cbecd09eb2ec152ab66879b383df442 (MD5) Previous issue date: 2016-03-31 / The studies on transport mechanics and sediment deposition in bed slope channels has rapidly increased over the last decade, this is associated with the fact that they play a fundamental role on the formation of hydrocarbon reservoirs. This work aims to investigate, through direct numerical simulation, the plunge phenomena dynamics when a heavier density fluid, full of particles, flows into a lower density environment. Simulations were carried out with Incompact3d, a code based on a Boussinesq system for incompressible fluids was utilized. The channel?s entrance sediment concentration and flow rate influence on the plunge point and deposition profiles were investigated. Results are compared with theoretical models and physical experiments. / O estudo dos mecanismos de transporte e deposi??o dos sedimentos em canal ganhou destaque nas ?ltimas d?cadas, j? que antigos dep?sitos sedimentares no leito do mar formam importantes reservat?rios de hidrocarbonetos. A inten??o desta pesquisa ? investigar, atrav?s de simula??o num?rica direta, a din?mica do fen?meno de mergulho que ocorre quando um escoamento carregado de part?culas em suspens?o adentra em um ambiente de menor densidade. Para tanto, utiliza-se o c?digo computacional Incompact3d, baseado na solu??o da equa??o de Boussinesq para fluidos incompress?veis. ? investigada a influ?ncia da vaz?o e concentra??o de sedimentos na entrada do canal sobre o ponto de mergulho e perfis de deposi??o, e os resultados s?o comparados com modelos te?ricos e experimentos f?sicos.
6

Caracteriza??o geol?gica, geomorfol?gica e oceanogr?fica do Sistema Pisa Sal, Galinhos/RN - Nordeste do Brasil, com ?nfase ? eros?o, ao transporte e ? sedimenta??o

Costa Neto, Le?o Xavier da 27 February 2009 (has links)
Submitted by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2017-08-29T21:47:08Z No. of bitstreams: 1 Le?o Xavier da Costa Neto_TESE.pdf: 17237342 bytes, checksum: 34347f57336cb2d8b2728d4e7e54da2f (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2017-08-29T21:49:31Z (GMT) No. of bitstreams: 1 Le?o Xavier da Costa Neto_TESE.pdf: 17237342 bytes, checksum: 34347f57336cb2d8b2728d4e7e54da2f (MD5) / Made available in DSpace on 2017-08-29T21:49:31Z (GMT). No. of bitstreams: 1 Le?o Xavier da Costa Neto_TESE.pdf: 17237342 bytes, checksum: 34347f57336cb2d8b2728d4e7e54da2f (MD5) Previous issue date: 2009-02-27 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico (CNPq) / Este trabalho tem como objetivo estudar o comportamento das caracter?sticas f?sicoambientais do sistema Pisa Sal, especificamente, a configura??o batim?trica, a caracteriza??o faciol?gica e a morfologia de fundo; o padr?o de circula??o das correntes de mar?s e das propriedades termohalinas; as zonas de eros?o e sedimenta??o, o volume de material erodido e suas rela??es com a hidrodin?mica; o transporte de sedimentos, a idade dos sedimentos e a taxa de sedimenta??o. Para isso, foram realizados levantamentos, meteorol?gico, batim?trico, sonogr?fico, oceanogr?fico (correntes e propriedades termohalinas), topogr?fico, amostragem de sedimentos de fundo e suspens?o e data??o por 14C e 210Pb. O sistema Pisa Sal faz parte do complexo estuarino lagunar Galinhos-Guamar?, localizado no litoral setentrional do estado do Rio Grande do Norte, no munic?pio de Galinhos-RN, uma regi?o sob influ?ncia da ind?stria salineira, carcinicultura e ind?stria petrol?fera. As informa??es meteorol?gicas definem para regi?o um clima seco com temperatura elevada, precipita??o baixa e ventos fortes e constantes que influenciam sobremaneira nas altera??es ambientais do sistema. O sistema Pisa Sal apresenta pequenas dimens?es (extens?o de 8,0 km, largura m?dia de 150 m e profundidade m?xima de - 4,23 m), perfil longitudinal regular, perfil transversal em ?V? (montante) e em ?U? (jusante), gradiente horizontal e diferentes formas de leito (fundo plano, marcas de ondas, dunas subaqu?ticas 2D e 3D, superposi??o de formas e rochoso). As f?cies sedimentares s?o representadas por sedimentos arenosos e lamosos de composi??o silic?tica, com varia??o na quantidade de gr?nulo e cascalho biodetr?ticos. Texturalmente, os sedimentos variam de areia muito grossa a silte. As correntes de mar?s variam de sim?trica a fracamente assim?tricas, com maiores velocidades durante as vazantes de siz?gia no per?odo de inverno, com dire??es que refletem a orienta??o dos canais. Os canais artificiais de despesca/drenagem (CDs) apresentam o mesmo comportamento do canal Pisa Sal, por?m com menor intensidade. As propriedades termohalinas classificam o sistema Pisa Sal como um canal de mar? com caracter?sticas hipersalinas, comportamento de um estu?rio inverso (negativo), verticalmente bem misturado, for?ado, predominantemente, pela mar?, no qual o processo de difus?o turbulenta da mar? ? respons?vel pelo transporte de sal canal acima e que provoca a redu??o da salinidade ao longo do ano. A eros?o no canal Pisa Sal e nos CDs est?o associadas ? margem c?ncava dos meandros causadas por fen?menos oceanogr?ficos, clim?ticos e antr?picos, entre os quais destacam-se: as mar?s, as correntes de mar?s, a chuva, o escoamento superficial, o vento, as ondula??es,a escava??o de canais, a infiltra??o, a composi??o e a manuten??o de taludes. O transporte de sedimentos de fundo e suspens?o ? controlado pela varia??o da velocidade das correntes de mar?s. O transporte ? mais eficiente durante as mar?s de siz?gia e nos ciclos de vazante, causando exporta??o de sedimentos. A idade dos sedimentos do canal Pisa Sal ? de 1562 ? 22 cal AP e do canal Volta do Sert?o ? 332- 432 ? 25 anos cal AP. A taxa de sedimenta??o nesses dois canais varia de 0,47 e 0,50 cm/ano, respectivamente. As atividades econ?micas da ind?stria salineira, da carcinicultura e da ind?stria petrol?fera associadas aos fen?menos naturais (temperatura do ar e n?vel de evapora??o alto, ?ndice de precipita??o baixo, regime de mesomar?, velocidade alta das correntes de mar?s e a??o dos ventos) s?o respons?veis pelas altera??es ambientais que ocorrem no sistema Pisa Sal. / The present work has as objective to study the behavior of physical-environmental characteristics of the Pisa Sal system, particularly the bathymetry, the facies characterization and the bottom morphology; the pattern of tidal currents circulation and of the termohalinas properties; the erosion and sedimentation zones, the bulk erosion and your relationships with the hydrodynamic; the sediments transport, the sediments age and sedimentation rate. The integrated data set used includes meteorological, bathymetric, sonographic, oceanographic (currents and termohalinas properties), topographic and sedimentological data, as well 14C and 210Pb datation. The Pisa Sal system is part of the Galinhos-Guamar? lagoon-estuarine complex, located in Galinhos, northern coast of the Rio Grande do Norte state. It is an area under influence of salt industry, shrimp farming and oil industry. The meteorological data classifies the area climate as dry, with high temperature, low precipitation and strong and constant winds, responsible for important environmental alterations in the system. The Pisa Sal system presents small dimensions (extension of 8,0 km, medium width of 150 m and maximum depth of -4,23 m), longitudinal profile to regulate, traverse profile in " V " (head) and in " U " (mouth), horizontal gradient, and different bedforms (e.g. ripples marks, 2D and 3D sub-aquatic dunes, flat, rocky). The sedimentary facies are represented by siliciclastic sandy and muddy sediments, with amount variation of biodetritic granule and gravel. The sediments texture varies from very coarse sand to silt. The tidal currents changes from weakly asymmetric to symmetrical, with higher speeds during the ebb-spring tide in the winter period, and directions reflecting the channels orientation. The drainage artificial channels (CDs) present the same behavior of the Pisa Sal channel, however with smaller intensity. The thermohaline properties classify the system as a tidal channel with hyper-saline characteristics, behavior of an inverse estuary (negative estuary), vertically very mixed, tidal forced, where the turbulent diffusion process is responsible for the salt transport and by the salinity reduction over the year. The Pisa Sal channel and CDs erosion are associated to the concave margin of the meandring channel caused by oceanographical, climatic and anthropic phenomena, which stand out: tides, tidal currents, rain, superficial drainage, winds, small waves, channels excavation, infiltration, composition and slope maintenance. The transport of bottom sediments and suspension is controlled by the speed variation of tidal currents. It is more efficient during the spring tides and in the ebb cycles, causing sediments exports. The age of the sediments of the Pisa Sal channel is 1562 ? 22 cal years AP and of the Volta do Sert?o channel is 332-432 ? 25 cal years AP. The calculated sedimentation rates in these two channels was 0,47 and 0,50 cm/year, respectively. The economical activities of the salt industry, shrimp farming and oil industry associated to the natural phenomena (temperature of the air and high evaporation level, low precipitation index, mesotidal conditions, high speed of the tidal currents and winds) are responsible for the environmental alterations in the Pisa Sal system.
7

Cinem?tica de part?culas em fluidos de viscosidade vari?vel com o tempo e sua aplica??o na constru??o de po?os de petr?leo: avalia??o durante paradas operacionais

Pinto, Gustavo Henrique Vieira Pereira 03 November 2008 (has links)
Made available in DSpace on 2014-12-17T14:08:31Z (GMT). No. of bitstreams: 1 GustavoHVPP.pdf: 1012393 bytes, checksum: d85648d797f788ab43d046f3e32bca54 (MD5) Previous issue date: 2008-11-03 / The new oil reservoirs discoveries in onshore and ultra deep water offshore fields and complex trajectories require the optimization of procedures to reduce the stops operation during the well drilling, especially because the platforms and equipment high cost, and risks which are inherent to the operation. Among the most important aspects stands out the drilling fluids project and their behavior against different situations that may occur during the process. By means of sedimentation experiments, a correlation has been validated to determe the sedimentation particles velocity in variable viscosity fluids over time, applying the correction due to effective viscosity that is a shear rate and time function. The viscosity evolution over time was obtained by carrying out rheologic tests using a fixed shear rate, small enough to not interfere in the fluid gelling process. With the sedimentation particles velocity and the fluid viscosity over time equations an iterative procedure was proposed to determine the particles displacement over time. These equations were implemented in a case study to simulate the cuttings sedimentation generated in the oil well drilling during stops operation, especially in the connections and tripping, allowing the drilling fluid project in order to maintain the cuttings in suspension, avoiding risks, such as stuck pipe and in more drastic conditions, the loss of the well / As novas descobertas de reservat?rios de petr?leo em campos onshore e offshore em l?minas d ?guas ultra-profundas e de trajet?rias complexas demandam a otimiza??o dos processos de perfura??o para reduzir as opera??es de paradas durante a perfura??o de um po?o, especialmente devido ao elevado custo das plataformas, equipamentos e dos riscos que s?o inerentes ? opera??o. Dentre os aspectos mais importantes destaca-se o projeto de fluidos de perfura??o e o estudo de seu comportamento frente a diferentes situa??es que podem ocorrer durante o processo. Atrav?s de experimentos de sedimenta??o, foi validada uma correla??o para determina??o da velocidade de sedimenta??o de part?culas em fluidos de viscosidade vari?vel com o tempo, aplicando-se as devidas corre??es para viscosidade efetiva que ? fun??o da taxa de deforma??o e do tempo. A evolu??o da viscosidade com o tempo foi obtida atrav?s de ensaios reol?gicos utilizando uma taxa de deforma??o fixa, pequena o suficiente para n?o interferir no processo de gelifica??o do fluido. Com as equa??es de velocidade de sedimenta??o de part?culas e da viscosidade do fluido com o tempo foi proposto um procedimento iterativo capaz de determinar o deslocamento das part?culas com o tempo. Essas equa??es constitutivas foram aplicadas no estudo de caso para simula??o da sedimenta??o dos cascalhos gerados na perfura??o de um po?o de petr?leo durante paradas operacionais, especialmente as conex?es e manobras, possibilitando o projeto do fluido de perfura??o de maneira a manter os cascalhos em suspens?o, evitando riscos, como por exemplo, a pris?o da coluna de perfura??o e em condi??es mais dr?sticas, a perda do po?o
8

Evolu??o morfotect?nica da por??o centro-sul da Bacia Para?ba

Lima, Jean Carlos Ferreira de 08 March 2016 (has links)
Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2016-08-25T20:24:52Z No. of bitstreams: 1 JeanCarlosFerreiraDeLima_TESE.pdf: 23398507 bytes, checksum: fb46bab4c3c63c30912415f64f97c8b4 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2016-08-25T22:13:57Z (GMT) No. of bitstreams: 1 JeanCarlosFerreiraDeLima_TESE.pdf: 23398507 bytes, checksum: fb46bab4c3c63c30912415f64f97c8b4 (MD5) / Made available in DSpace on 2016-08-25T22:13:57Z (GMT). No. of bitstreams: 1 JeanCarlosFerreiraDeLima_TESE.pdf: 23398507 bytes, checksum: fb46bab4c3c63c30912415f64f97c8b4 (MD5) Previous issue date: 2016-03-08 / Processos end?genos recentes proporcionam din?mica ? litosfera e geram as mais variadas formas de relevo, mesmo em ?reas de margens continentais passivas, como ? o caso da ?rea de pesquisa deste trabalho, localizada no Nordeste brasileiro. A reativa??o das estruturas do embasamento pr?-cambriano, ap?s a separa??o entre a Am?rica do Sul e ?frica no Cret?ceo, teve um papel importante na evolu??o de suas bacias, o que proporcionou formas de relevo variadas. Estas caracter?sticas morfodin?micas podem ser facilmente percebidas nos sedimentos de borda das bacias marginais, que apresentam fortes ind?cios dessas reativa??es. O objetivo deste trabalho ? investigar a influ?ncia dos processos morfotect?nicos na estrutura??o da paisagem nos sedimentos da Bacia Para?ba. Para tanto foram utilizados dados aeromagn?ticos de alta resolu??o, imagens da Shuttle Radar TopographicMission-SRTM, dados geol?gicos estruturais, dados de po?os profundos e dados geol?gicos de campo. Nos resultados foi observado que algumas estruturas conhecidas no embasamento da Bacia Para?ba coincidem com os lineamentos magn?ticos e topogr?ficos interpretados como reativa??es de falhas do P?s-Mioceno. A atividade neotect?nica ocorrida na Bacia Para?ba teve a capacidade de reorganizar a deposi??o dos sedimentos e de dominar os padr?es das formas de relevo. Dados estruturais adquiridos nas unidades litoestratigr?ficas mostram evid?ncias de atividade tect?nica associada ? deposi??o e eros?o de sedimentos do final do Cret?ceo at? o presente. Isto indica que a deposi??o dos sedimentos p?s-cret?ceos foi influenciada por reativa??es de estruturas do embasamento pr?-cambriano nesta por??o da margem continental brasileira. / Recent endogenous processes provide dynamic movements in the lithosphere and generate the varied forms of relief, even in areas of passive continental margins, such as the research area of this work located in northeastern Brazil. The reactivation of Precambrian basement structures, after the breakup between South America and Africa in the Cretaceous played an important role in the evolution of basins, which provided generated forms of relief. These morphodynamic characteristics can be easily observed in marginal basins that exhibit strong evidence fault reactivations. The purpose of this study is to investigate the influence of morphotectonic processes in the landscape structuring of Para?ba Basin. Therefore, we used aeromagnetic, high?resolution images of the Shuttle Radar Topographic Mission?SRTM, structural geological data, deep well data and geological field data. Based on the results of the data was observed that some preexisting structures in the crystalline basement coincide with magnetic and topographic lineaments interpreted as fault reactivation of the Post?Miocene units in the Para?ba Basin. Faults that offset lithostratigraphic units provided evidence that tectonic activity associated with the deposition and erosion in the Para?ba Basin occurred from Cretaceous to the Quaternary. The neotectonic activity that occurred in Para?ba Basin was able to influence the deposition of sedimentary units and landforms. It indicates that the deposition of post?Cretaceous units was influenced by reactivation of Precambrian basement structures in this part of the Brazilian continental margin.

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