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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.
531

Volatile Organic Compound (VOC) Emission during Cured-in-Place-Pipe (CIPP) Sewer Pipe Rehabilitation

Bourbour Ajdari, Elena 13 May 2016 (has links)
The maintenance or replacement of deteriorated pipes and culverts is a constant and significant concern for municipalities and transportation agencies in the United States (Donaldson and Wallingford, 2010). Trenchless technologies and especially the Cured-in-place pipe (CIPP) method have become increasingly common ways to preserve infrastructures owing to their feasibility, cost-effectiveness, and fewer social impacts (Jung and Sinha, 2007). Therefore, there is a growing need to understand the direct and indirect effects of pipeline rehabilitation activities on the environment. Nearly all past CIPP studies have focused on its mechanical properties, and its environmental impacts are poorly investigated and documented (Allouche et al. 2012). Sewer pipelines and storm-water culverts are administered by municipalities and transportation agencies who bear the responsibility for rehabilitation and renewal of these infrastructures. In consequence, they rarely allow sampling and research projects in the field due to liability issues. This is a main obstacle to conducting comprehensive, precise, and unbiased research on CIPP environmental impacts and to date, the degree of relevant health effects and related environmental impacts have remained unknown. Numerous building indoor air contamination incidents indicate that work is needed to understand the magnitude of styrene emission from CIPP sanitary sewer repairs. The main goal of this study was to better comprehend Volatile Organic Compounds emission at three CIPP sanitary sewer installation sites in one U.S. city. Results showed that CIPP chemical emissions may be a health risk to workers and nearby building inhabitants. Additional testing and investigations regarding chemical emissions from CIPP should be commissioned to fill in the environmental and public health knowledge gaps. The acute and chronic chemical exposure risks of CIPP chemical steam constituents and styrene to sensitive populations should be further examined. Other goals of this study were to estimate the magnitude of solid waste generated as well as the amount of certain criteria air pollutants and greenhouse gases emitted from onsite heavy equipment for both CIPP and open-cut sites in a U.S city. The results indicated that the amount of open-cut related solid waste, criteria air pollutants, and greenhouse gases were greater than those during CIPP activities. Additional work is needed to quantify pollutant emissions from CIPP and open-cut activities and consider emissions from a cradle-to-grave standpoint.
532

Photocatalytic degradation of dyes and pesticides in the presence of ions

Pete, Kwena Yvonne 03 1900 (has links)
M. Tech. (Department of Chemical Engineering, Faculty of Engineering and Technology), Vaal University of Technology / Water pollution caused by organic and inorganic contaminants represents an important ecological and health hazard. Simultaneous treatment of organic and inorganic contaminants had gradually gained great scientific interest. Advanced oxidation processes such as photocatalysis, using TiO2 as a photocatalyst, have been shown to be very robust in the removal of biorecalcitrant pollutants. These methods offer the advantage of removing the pollutants, in contrast to conventional techniques. At present, the main technical challenge that hinder its commercialization remained on the post-recovery of the photocatalyst particles after water treatment. Supporting of the photocatalyst on the adsorbent surface is important as it assists during the filtration step, reducing losses of the materials and yielding better results in degrading pollutants. To overcome this challenge, in this study composite photocatalysts of TiO2/zeolite and TiO2/silica were prepared and investigated to explore the possible application in the simultaneous removal of organic and inorganic compounds from contaminated water. The main objective of this study was to investigate the heterogeneous photocatalytic degradation of organic compounds in the presence of metal ions using composite photocatalysts. The Brunauer–Emmett–Teller (BET), Scanning Electron Microscopy and Energy Dispersive X-ray (SEM-EDX), Raman spectroscopy (RS) and zeta potential (ZP) analyses were used to characterize the prepared composite photocatalysts. The successive composite photocatalysts were used in a semi-batch reactor under an irradiation intensity of 5.5 mW/m2 (protected by a quartz sleeve) at 25 ± 3°C for the photocatalytic degradation of synthetic textile (methyl orange) and agricultural (atrazine) wastewater in the presence of ions. The effect of operating parameters such as TiO2 composition on supporting material, particle size, composite photocatalyst loading, initial pollutant concentration and pH were optimized. The effects of inorganic salts and humic acid on dye and pesticides degradation were also studied, respectively. The performance of the photocatalyst reactor was evaluated on the basis of color removal, metal ion reduction, total organic carbon (TOC) reduction, intermediates product analysis and modeling of kinetics and isotherms. Different kinetic and isotherm models were introduced and applied in this work. Important aspects such as error functions with the optimal magnitude were used for the selection of the best suitable model. / European Union. City of Mikkeli, Finland. Water Research Commission (RSA)
533

Avaliação da influência de fatores ambientais sobre o diagnóstico de artrite idiopática juvenil em crianças e adolescentes / Evaluation of the influence of environmental factors on the juvenile idiopathic arthritis in children and adolescents

França, Camila Maria Paiva 14 March 2017 (has links)
A artrite idiopática juvenil (AIJ) constitui um grupo heterogêneo de doenças que se caracteriza por inflamação crônica em uma ou mais articulações, com diagnóstico em menores de 16 anos de idade. A poluição atmosférica tem sido responsabilizada pelo aumento da morbidade e mortalidade em doenças cardiorrespiratórias, mas poucos estudos avaliaram os efeitos da exposição prolongada sobre doenças inflamatórias crônicas. Alguns estudos demonstram associação entre fumo e início da doença reumatológica em adultos e outros mostram associação de mães fumantes durante a gravidez com desenvolvimento de AIJ nos filhos. Entretanto, existem poucos estudos na literatura avaliando a exposição à poluição do ar e AIJ. Objetivo: avaliar a influência de poluentes ambientais inalatórios como fatores de risco no desenvolvimento da AIJ em pacientes residentes na Região Metropolitana de São Paulo, acompanhados em um serviço terciário de Reumatologia Pediátrica. Metodologia: Este foi um estudo retrospectivo, do tipo caso-controle, que incluiu 66 pacientes com AIJ e 124 controles saudáveis, semelhantes em idade e gênero, residentes na Região Metropolitana de São Paulo, desde a gestação até o diagnóstico da doença. Um questionário estruturado e com alto índice de confiabilidade (índice kappa para teste-reteste 0,80) avaliou dados demográficos, fatores relacionados à gestação e ao período perinatal, exposição ocupacional materna durante a gravidez a partículas inaláveis e/ou vapor volátil, exposição ao tabaco e exposição à inalação ambiental durante a gravidez e após o nascimento (presença de atividades industriais, pedreiras ou postos de gasolina perto do domiícilio/ trabalho/ creche/ escola). Foram também analisados poluentes troposféricos nos dois períodos: material particulado (PM10), dióxido de enxofre (SO2), dióxido de nitrogênio (NO2), ozônio (O3) e monóxido de carbono (CO). Resultados: Durante a gravidez, o fumo fetal (OR= 3,43, IC 95%: 1,45-8,12, p=0,005) e a exposição ocupacional materna (OR= 13,69, IC95%: 4,43-42,27, p < 0,001) se mostraram fatores de risco independentes para AIJ. Em contrapartida, o fato de a mãe trabalhar fora de casa (OR= 0,06, IC 95%: 0,02- 0,16, p < 0,001) e o ganho de peso ideal da mãe (OR = 0,36, IC 95%: 0,16-0,83, p= 0,017) apresentaram associação negativa. Para o período após o nascimento até o diagnóstico de AIJ, fumo passivo (OR= 3,6, IC 95%: 1,76- 7,31, p < 0,0001) e exposição ao ozônio durante o segundo ano de idade (OR= 2,76, IC 95%: 1,20-6,37, p= 0,017) foram fatores de risco independentes e significativos para o diagnóstico da AIJ. Conclusão: O fumo passivo, a exposição ao ozônio no segundo ano de vida e a exposição ocupacional materna são destacados como importantes fatores de risco para a AIJ / Juvenile idiopathic arthritis (JIA) is a heterogeneous group of diseases characterized by chronic inflammation in one or more joints with onset in children under 16 years of age. Air pollution has been blamed for increased morbidity and mortality in cardiorespiratory diseases, but few studies have evaluated the effects of prolonged exposure on chronic inflammatory diseases. Some studies show an association between smoking and onset of rheumatologic illness in adults, and others show an association of smoking mothers during pregnancy with the development of JIA in children. However, there are few studies in the literature to date evaluating exposure to air pollution and JIA. Objective: To evaluate the influence of exposure to inhalable environmental factors during pregnancy and after birth until JIA diagnosis in residents of the São Paulo metropolitan area. Methods: Case-control study comprising 66 JIA patients and 124 healthy controls matched by age and gender, living in the Sao Paulo metropolitan area until JIA diagnosis, and whose mothers had resided in this region during pregnancy. A structured and reliable questionnaire (kappa index for test-retest was 0.80) assessed demographic data, gestational and perinatal-related factors, mothers\' work-related exposure during pregnancy to inhalable particles and / or volatile vapor, exposure to inhalable elements during pregnancy and after birth (work-related exposure to inhalable particles and/or volatile vapor, exposure to tobacco and the presence of industrial activities, quarries or gas stations near the home/ work/ daycare/ school). Tropospheric pollutants included: particulate matter (PM10), sulphur dioxide (SO2), nitrogen dioxide (NO2), ozone (O3) and carbon monoxide (CO). Results: During pregnancy, fetal smoking (OR=3.43, 95%CI: 1.45-8.12, p=0.005) and mothers\' work-related exposure (OR=13.69, 95%CI: 4.43-42.27, p < 0.001) were independent significant risk factors for JIA diagnosis. In contrast, working mother (OR=0.06, 95% IC: 0.02-0.16, p < 0.001) and ideal mother weight gain (OR=0.36, 95% IC:0.16-0.83, p=0.017) presented a negative association. After birth until JIA diagnosis, secondhand smoking (OR=3.6, 95% IC: 1.76-7.31, p < 0.0001) and exposure to O3 during the second year of age (OR=2.76, 95% IC: 1.20-6.37, p=0.017) were independent and significant risk factors for JIA diagnosis. Conclusion: Secondhand smoking, exposure to O3 during the second year of age and mothers\' work-related exposure are highlighted as important risk factors to JIA
534

"Avaliação da atividade clastogênica do resíduo catalítico industrial, por meio do bioensaio de micronúcleos com Tradescantia pallida cv. Purpurea" / Clastogenicity evaluation of industrial catalytic waste using the Tradescantia pallida cv. Purpurea micronucleus biossay (Trad-MCN)

Santos, Iara Terezinha Queiroz Pereira dos 03 September 2004 (has links)
O objetivo deste estudo foi aumentar o banco de dados em relação a resíduos (cake) e efluentes (licor) industriais e o seu nível de clastogenicidade. Este estudo contribuiu para mostrar: a) que o bioensaio com Tradescantia pallida foi sensível para a avaliação da clastogenicidade em mistura complexa de resíduos catalíticos industriais, nunca testados anteriormente. b) a tendência de uma dose resposta para ambos os resíduos catalíticos c)a pasta (cake) apresenta maior clastogenicidade que o licor nas concentrações estudadas. Provavelmente isto se deve a menor concentração de Ti e Al no licor do que no cake. / The aim of this study was to increase data concerning liquid effluent (liquor) and solid waste (cake) and their level of clastogenicity using TradMCN. This study contributed to show a) bioassay Trad-MCN with Tradescantia pallida was sensitive to evaluate the clastogenicity in a complex waste mixture, never tested before b) a tendency of a dose response for both catalytic wastes. c) higher clastogenicity of cake comparing to liquor effluent in concentrations evaluated. Probably this is due to the much lower Ti and Al concentrations in the liquor than in the cake
535

Regulating human mammary epithelial stem cells transformation : an interplay between extrinsic and intrinsic signals / La régulation des cellules souches épithéliales mammaires humaines : un jeu entre signaux extrinsèques et intrinsèques

Clément, Flora 05 May 2017 (has links)
L'incidence, le coût et l'issue fatale dans un nombre encore trop élevé de cas font du cancer un problème majeur en santé publique. Malgré les progrès réalisés dans le développement de thérapies ciblées, la plupart des cancers rechutent, vraisemblablement à cause de l'échappement des cellules souches cancéreuses (CSC) qui survivent et régénèrent la tumeur. L'enjeu clinique en cancérologie aujourd'hui est d'éliminer les cellules souches cancéreuses en épargnant les cellules souches normales. Pour atteindre cet objectif, il est primordial de comprendre leurs mécanismes spécifiques de transformation. Nous évaluons dans mon équipe de recherche l'implication du microenvironnement dans la transformation et la résistance des CSC épithéliales, à travers les effets de facteurs solubles et de contacts cellulaires : l'enzyme CD10, et la voie des BMPs (Bone Morphogenetic Proteins).Notre équipe étudie le rôle du dialogue permanent entre la CS normale et son microenvironnement qui régule la prolifération, et la survie des CS. Nous utilisons la glande mammaire et la prostate comme systèmes modèles car ces deux types d'épithélium présentent des similitudes, ce qui nous permet d'aborder la question de l'apparition et la résistance des CSC dans deux modèles tumoraux correspondants. Des dérégulations de la voie des BMPs, comme de l'enzyme CD10 sont observées dans ces tumeurs. Enfin, nous cherchons à comprendre comment les dérégulations de la voie des BMPs apparaissent, en s'intéressant principalement aux facteurs pouvant modifier directement le microenvironnement, tels que les polluants présents dans l'environnement (bisphénols, benzoapyrène) / It has been shown for a number of cancers that a cell population characterized by stem cell (SC) properties and therapeutic resistance is likely responsible for relapse several years after treatment. Current therapies kill most of the tumor cells, but fail to eradicate the so-called cancer stem cells (CSC). Therefore a complete cure of the disease will require the eradication of the tumor-sustaining CSC. We propose to study these CSC in the context of breast cancer as the existence of CSC as already been highlighted in this epithelia.CD10 is a membrane enzyme able to cleave several peptide of the microenvironment (such as oxytocin, bombesin, enkephalin.. ) that can also interact with intracellular signalling pathway through its direct interaction with PTEN. Our results, and those of the literature, indicate that CD10 enzyme controls the fate of SC and is deregulated in normal breast and cancerous tissues. We showed that CD10 membrane expression allows the maintenance of immature cells partly through its enzymatic function that inhibits mammary stem cells differentiation. As CD10 has been described in breast cancer initiation, progression and resistance, we then decided to test the role of CD10 in tumor context. Our strategy consists in flow cytometry cell sorting for CD10+/CD10- cells to compare the functional properties of both sub-population. Only CD10+ cells are able to regenerate both CD10+ and CD10- subpopulations, and CD10+ cells exhibit higher expression of immature genes. Interestingly, modulating CD10 using stable expression of CD10 in our models and Sh strategies do not mimick the normal functions of CD10, indicating that CD10 could be more a marker of a certain population with immature properties prone to transformation rather than a driver. To better characterize the role of CD10 in luminal breast transformation, we developed a new human mammary model, initiated from immature cells to obtain transformed luminal epithelial cells and their resistant counterpart. We observed a higher level of CD10 expression during mammary epithelial cell transformation process. We then performed a microarray on CD10+ and CD10- subpopulations. Preliminary analysis seems to confirm that CD10 is a potential marker for a stem cell population prone to transformation rather than a direct driver of the cell transformation
536

Avaliação da influência de fatores ambientais sobre o diagnóstico de artrite idiopática juvenil em crianças e adolescentes / Evaluation of the influence of environmental factors on the juvenile idiopathic arthritis in children and adolescents

Camila Maria Paiva França 14 March 2017 (has links)
A artrite idiopática juvenil (AIJ) constitui um grupo heterogêneo de doenças que se caracteriza por inflamação crônica em uma ou mais articulações, com diagnóstico em menores de 16 anos de idade. A poluição atmosférica tem sido responsabilizada pelo aumento da morbidade e mortalidade em doenças cardiorrespiratórias, mas poucos estudos avaliaram os efeitos da exposição prolongada sobre doenças inflamatórias crônicas. Alguns estudos demonstram associação entre fumo e início da doença reumatológica em adultos e outros mostram associação de mães fumantes durante a gravidez com desenvolvimento de AIJ nos filhos. Entretanto, existem poucos estudos na literatura avaliando a exposição à poluição do ar e AIJ. Objetivo: avaliar a influência de poluentes ambientais inalatórios como fatores de risco no desenvolvimento da AIJ em pacientes residentes na Região Metropolitana de São Paulo, acompanhados em um serviço terciário de Reumatologia Pediátrica. Metodologia: Este foi um estudo retrospectivo, do tipo caso-controle, que incluiu 66 pacientes com AIJ e 124 controles saudáveis, semelhantes em idade e gênero, residentes na Região Metropolitana de São Paulo, desde a gestação até o diagnóstico da doença. Um questionário estruturado e com alto índice de confiabilidade (índice kappa para teste-reteste 0,80) avaliou dados demográficos, fatores relacionados à gestação e ao período perinatal, exposição ocupacional materna durante a gravidez a partículas inaláveis e/ou vapor volátil, exposição ao tabaco e exposição à inalação ambiental durante a gravidez e após o nascimento (presença de atividades industriais, pedreiras ou postos de gasolina perto do domiícilio/ trabalho/ creche/ escola). Foram também analisados poluentes troposféricos nos dois períodos: material particulado (PM10), dióxido de enxofre (SO2), dióxido de nitrogênio (NO2), ozônio (O3) e monóxido de carbono (CO). Resultados: Durante a gravidez, o fumo fetal (OR= 3,43, IC 95%: 1,45-8,12, p=0,005) e a exposição ocupacional materna (OR= 13,69, IC95%: 4,43-42,27, p < 0,001) se mostraram fatores de risco independentes para AIJ. Em contrapartida, o fato de a mãe trabalhar fora de casa (OR= 0,06, IC 95%: 0,02- 0,16, p < 0,001) e o ganho de peso ideal da mãe (OR = 0,36, IC 95%: 0,16-0,83, p= 0,017) apresentaram associação negativa. Para o período após o nascimento até o diagnóstico de AIJ, fumo passivo (OR= 3,6, IC 95%: 1,76- 7,31, p < 0,0001) e exposição ao ozônio durante o segundo ano de idade (OR= 2,76, IC 95%: 1,20-6,37, p= 0,017) foram fatores de risco independentes e significativos para o diagnóstico da AIJ. Conclusão: O fumo passivo, a exposição ao ozônio no segundo ano de vida e a exposição ocupacional materna são destacados como importantes fatores de risco para a AIJ / Juvenile idiopathic arthritis (JIA) is a heterogeneous group of diseases characterized by chronic inflammation in one or more joints with onset in children under 16 years of age. Air pollution has been blamed for increased morbidity and mortality in cardiorespiratory diseases, but few studies have evaluated the effects of prolonged exposure on chronic inflammatory diseases. Some studies show an association between smoking and onset of rheumatologic illness in adults, and others show an association of smoking mothers during pregnancy with the development of JIA in children. However, there are few studies in the literature to date evaluating exposure to air pollution and JIA. Objective: To evaluate the influence of exposure to inhalable environmental factors during pregnancy and after birth until JIA diagnosis in residents of the São Paulo metropolitan area. Methods: Case-control study comprising 66 JIA patients and 124 healthy controls matched by age and gender, living in the Sao Paulo metropolitan area until JIA diagnosis, and whose mothers had resided in this region during pregnancy. A structured and reliable questionnaire (kappa index for test-retest was 0.80) assessed demographic data, gestational and perinatal-related factors, mothers\' work-related exposure during pregnancy to inhalable particles and / or volatile vapor, exposure to inhalable elements during pregnancy and after birth (work-related exposure to inhalable particles and/or volatile vapor, exposure to tobacco and the presence of industrial activities, quarries or gas stations near the home/ work/ daycare/ school). Tropospheric pollutants included: particulate matter (PM10), sulphur dioxide (SO2), nitrogen dioxide (NO2), ozone (O3) and carbon monoxide (CO). Results: During pregnancy, fetal smoking (OR=3.43, 95%CI: 1.45-8.12, p=0.005) and mothers\' work-related exposure (OR=13.69, 95%CI: 4.43-42.27, p < 0.001) were independent significant risk factors for JIA diagnosis. In contrast, working mother (OR=0.06, 95% IC: 0.02-0.16, p < 0.001) and ideal mother weight gain (OR=0.36, 95% IC:0.16-0.83, p=0.017) presented a negative association. After birth until JIA diagnosis, secondhand smoking (OR=3.6, 95% IC: 1.76-7.31, p < 0.0001) and exposure to O3 during the second year of age (OR=2.76, 95% IC: 1.20-6.37, p=0.017) were independent and significant risk factors for JIA diagnosis. Conclusion: Secondhand smoking, exposure to O3 during the second year of age and mothers\' work-related exposure are highlighted as important risk factors to JIA
537

Nonpoint-Source Pollutants to Determine Runoff Source Areas

Lane, L. J., Norton, H. L., Wallace, D. E., Wilson, R. E., Martin, R. D. 16 April 1977 (has links)
From the Proceedings of the 1977 Meetings of the Arizona Section - American Water Resources Assn. and the Hydrology Section - Arizona Academy of Science - April 15-16, 1977, Las Vegas, Nevada / Hydrologic information is needed to understand and control water pollution from semiarid rangelands. However, the hydrologic systems under any given conditions must be understood and the effects of various land uses predicted. Based on the concept of partial area response, a runoff tracer study was conducted on two small watersheds. The watersheds were partitioned into four geomorphic subzones or hydrologic response units. Each of the four zones on both watersheds was treated with about 1 kg/ha of an individual water soluble herbicide. Runoff volumes and sources estimated using the tracers were consistent with results from simulation studies. Also, the principle of corresponding runoff and pollutant discharge rates was used to develop two methods of runoff hydrograph estimation from each of the geomorphic subzones. Method 1 matched the mean total concentration and total runoff volume. Method 2 matched the instantaneous total concentration and the instantaneous runoff rate from the entire watershed. Results from the two methods suggested that, although they may be equivalent with respect to runoff volume, Method 2 may be more consistent with respect to peak discharge.
538

Health risk assessment of dioxin-like compounds in complex samples /

Öberg, Mattias U. L., January 2003 (has links)
Diss. (sammanfattning) Stockholm : Karol. inst., 2003. / Härtill 5 uppsatser.
539

Characterization of risk from airborne benzene exposure in the state of Florida

Johnson, Giffe. January 2008 (has links)
Dissertation (Ph.D.)--University of South Florida, 2008. / Title from PDF of title page. Document formatted into pages; contains 98 pages. Includes vita. Includes bibliographical references.
540

Modelagem e simulação fluidodinâmica da dispersão de poluentes na microescala atmosférica. / Fluid dynamics modeling and simulation of dispersion of pollutants in the atmospheric microscale.

GOMES, Valério de Araújo. 26 March 2018 (has links)
Submitted by Johnny Rodrigues (johnnyrodrigues@ufcg.edu.br) on 2018-03-26T21:38:56Z No. of bitstreams: 1 VALÉRIO DE ARAÚJO GOMES - TESE PPGEQ 2017..pdf: 1988053 bytes, checksum: b420f6b012569ad3bbe40c4e9567f181 (MD5) / Made available in DSpace on 2018-03-26T21:38:56Z (GMT). No. of bitstreams: 1 VALÉRIO DE ARAÚJO GOMES - TESE PPGEQ 2017..pdf: 1988053 bytes, checksum: b420f6b012569ad3bbe40c4e9567f181 (MD5) Previous issue date: 2017 / O desenvolvimento de modelos matemáticos aplicados a simulação de dispersão de poluentes na atmosfera, utilizando fluidodinâmica computacional, tem sido cada vez mais intenso em função da evolução tecnológica das rotinas computacionais. Porém, o maior desafio ainda é o entendimento e a modelagem adequada dos fenômenos que caracterizam a dispersão quando ocorrem em regime turbulento. Para o fechamento dos termos que representam a turbulência, o modelo de duas equações k- padrão é o que mais largamente tem sido utilizado. Contudo, este é um modelo desenvolvido a altos números de Reynolds e apresenta limitações quando o escoamento ocorre próximo das paredes do domínio. Desta forma, quando os efeitos de escoamentos a baixos números de Reynolds devem ser levados em consideração (quando a viscosidade molecular não pode ser desprezada), funções amortecedoras devem ser inseridas resultando em uma espécie de k- para baixos números de Reynolds. Com isso, esta tese tem como objetivo apresentar o desenvolvimento de um modelo de dispersão atmosférica matemático, tendo como contribuição científica o desenvolvido de equações empíricas para definição da função amortecimento (𝑓µ) no cálculo da viscosidade turbulenta, em complemento as funções “paredes” utilizadas comumente pelos códigos computacionais comerciais, corrigindo desta forma o modelo k- padrão. Como ferramenta computacional, foi utilizado o software CFX® para as simulações fluidodinâmicas. Para validação do modelo, foram utilizados os dados do experimento de Copenhagen. Os índices estatísticos do modelo também foram comparados com os resultados de outras pesquisas encontradas na literatura. Os resultados mostraram que a metodologia proposta foi capaz de simular o experimento de campo com um nível bastante satisfatório, atingindo um erro quadrático médio normalizado (NMSE) de 0,02 e um fator de correlação (Cor) de 0,95. / The development of mathematical models, which simulate the dispersion of pollutants in the atmosphere using computational fluid dynamics, has been increasingly intense due to the technological evolution of computational routines. For the closure of the terms representing the turbulence, the model of standard two equations k- is the most widely used. However, when the effects of low Reynolds numbers should be considered (when molecular viscosity cannot be neglected), damping functions should be inserted resulting in a kind of k- for low Reynolds numbers. This thesis aims to present the development of a mathematical atmospheric dispersion model, whose scientific contribution is the development of empirical equations to define the damping function (𝑓�µ) in the calculation of turbulent viscosity, in addition the functions "walls" commonly used by commercial computer codes. As a computational tool, CFX® software has been used to perform fluid dynamics simulation. For the validation of the model, the data from the Copenhagen experiment were used. The statistical indices of the model were also compared with the results of other studies found in the literature. The results showed that the proposed methodology was able to simulate the field experiment with a very satisfactory level, reaching a normalized mean square error (NMSE) of 0.02 and a correlation factor (Color) of 0.95.

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