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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.
581

Resolving the atmospheric sulphur budget over the Elandsfontein area of the Mpumalanga Highveld

Igbafe, Anselm Iuebego 02 September 2008 (has links)
A novel study on the investigation of three very common atmospheric sulphur species relevant to the Mpumalanga Highveld subregion was conducted. Long-term in situ measurements were applied in the diurnal and seasonal evaluation of the observed sulphur species. Ambient pollutant concentrations and surface meteorological data were collected at an air quality monitoring station at Elandsfontein. Elandsfontein air quality monitoring station was ideal for the observations due to its high elevation within the Mpumalanga Province surrounded by few rolling hills and negligible windbreaks which easily allows for extensive plume-contact with the surface during convective daytime mixing. The temporal characteristics of the sulphur species have been assessed relative to one another with varying meteorological conditions. The diurnal and seasonal concentration variations were used to describe the physical characteristics exhibited by the compounds over Elandsfontein. Pollution roses were used to target the source of the major release points and areas of these sulphur species relative to the Elandsfontein monitoring station. Gas and particle concentrations were analysed in relation to varying meteorological parameters with a view to ascertaining the sulphur transformation and concentration distribution in the planetary boundary layer. Particulate sulphate distribution has been modelled through multivariate regression analyses in relation to three meteorological parameters, namely, wind speed, relative humidity and ambient temperature for the various seasons observed over southern Africa. This study has shown that hydrogen sulphide, sulphur dioxide and sulphate species are present throughout the year in the Mpumalanga Highveld at notably significant levels. The presence of ambient particulate sulphate has been shown to result from the combination of chemical interactions during long-range aerosol transport; atmospheric recirculation processes shown from back trajectories over the southern Africa sub-region, as well as the variation in the removal mechanisms and rates for the different seasons throughout the year. These transport and removal processes all contribute to the overall sulphur mass balance in the planetary boundary layer. Dosage of the three sulphur species was evaluated to provide data for sulphur pollution loading that could form a basis for health and vii environmental impact assessments over the area. In view of the characteristic patterns displayed by particulate sulphate, multivariate mathematical models have been developed on a seasonal basis with variations in meteorological parameters. This was seen to predict an accuracy of up to 70 % of the particulate sulphate loading for different seasons over the South African Highveld. In order to understand the chemical interactions of atmospheric sulphur species, it is important to be able to predict the route taken and expected products of transformation on any given condition. Theoretical analyses of the chemical thermodynamic properties of the known reacting species and a well-established approach were used in predicting reaction paths and establishing the possible and feasible products of chemical transformation in relation to the ambient temperature. The determination of reaction paths and possible products of chemical transformation provides a measure of the relative importance of the reacting species and the mechanism of reaction. Gas-, aqueous-phase and radical reactions involving sulphur (IV) were investigated with a view to establishing their relative importances. Thermochemical properties of several sulphur-containing compounds not available in the literature have been generated for evaluation of Gibbs free energy (ΔG) and enthalpy (ΔH). An electronic energy structural approach has been applied to model for ΔG and ΔH of 88 sulphur species in 90 chemical reactions comprising gas-phase, aqueousphase and radical reactions. Modelling was evaluated for their relative importances over a temperature range of –100 °C to +100 °C. The temperature range is well above the known tropospheric temperature range to account for variations in the atmospheric environment. To further comprehend the chemistry of sulphur with regards to distribution of the species in the atmosphere, a kinetic model is developed and incorporated into a dispersion model. The kinetic evaluation of the oxidation rate of SO2 to sulphate has been determined with advection and dispersion over the Elandsfontein area. Gas-phase transformation with advection and dispersion has been used to evaluate the extent of the distribution of SO2 relative to the major contributing sources. The dry deposition was considered to be the dominant removal mechanism. It was assumed that the reaction rate was second order in concentration and that the rate of deposition was first order. The oxidation rates obtained for the seasons were 10.9 % h-1 for summer; 8.83 % h-1 for autumn; 6.56 % h-1 for winter; viii 10.8 % h-1 for spring, while an overall rate of 9.6 % h-1 was obtained for the one year study period. The transformation rate model produced a reaction constant and an activation energy of 4.92 x 10-6 μg m-3 s-1 and 36.54 kJ kg-1 for summer; 3.939 x 10-6 μg m-3 s-1 and 43.89 kJ kg-1 for autumn; 2.90 x 10-6 μg m-3 s-1 and 115.69 kJ kg-1 for winter; 4.82 x 10-6 μg m-3 s-1 and 43.29 kJ kg-1 for spring, while for the year 4.29 x 10-6 μg m-3 s-1 and 34.31 kJ kg-1. A Gaussian puff unsteady state Lagrangian dispersion model with reflection at the surface and inversion layer was applied for concentration diffusion. The Lagrangian dispersion model with dry deposition was a better prediction of the observed data than the models from previous studies using a first order rate constant with or without deposition rate.
582

Characterisation of ambient atmospheric aerosols using accelerator-based techniques

Sekonya, Kamela Godwin 15 April 2010 (has links)
Atmospheric haze, which builds up over South Africa including our study areas, Cape Town and the Mpumalanga Highveld under calm weather conditions, causes public concern. The scope of this study was to determine the concentration and composition of atmospheric aerosol at Khayelitsha (an urban site in the Western Cape) and Ferrobank (an industrial site in Witbank, Mpumalanga). Particulate matter was collected in Khayelitsha from 18 May 2007 to 20 July 2007 (i.e. 20 samples) using a Partisol-plus sampler and a Tapered Element Oscillating Microbalance (TEOM) sampler. Sampling took place at Ferrobank from 07 February 2008 to 11 March 2008 (6 samples) using a Partisol-plus sampler and an E-sampler. The gravimetric mass of each exposed sample was determined from pre- and post-sampling weighing. The elemental composition of the particulate matter was determined for 16 elements at Khayelitsha using Proton Induced X-ray Emission (PIXE). The concentration of the elements Al, Si, S, Cl, K, Ca, Ti, Cr, Mn, Fe, Cu, Zn, As, Br, Sn, and Pb was determined by analysing the PIXE spectra obtained. In similar manner, the elemental composition of the particulate matter was determined for 15 elements at Ferrobank (Al, Si, S, Cl, K, Ca, Ti, Cr, Mn, Fe, Cu, Zn, As, Br and Pb). The average aerosol mass concentrations for different days at the Khayelitsha site were found to vary between 8.5 μg/m3 and 124.38 μg/m3. At the Khayelitsha site on three occasions during the sampling campaign the average aerosol mass concentrations exceeded the current South African air quality standard of 75 μg/m3 over 24 h. At the Ferrobank site, there are no single days that exceeded the limit of the South African air quality standard during the sampling campaign. Enrichment factors for each element of the particles sampled with an aerodynamic diameter of less than 10 μm (PM10) samples have been calculated in order to identify their possible sources. The analysis yielded five potential sources of PM10 : soil dust, sea salt, gasoline emissions, domestic wood and coal combustion. Interestingly, enrichment factor values for the Khayelitsha samples show that sea salt constitutes a major source of emissions, while Ferrobank samples, the source apportionment by unique ratios (SPUR) indicate soil dust and coal emission are the major sources of pollution. The source apportionment at Khayelitsha shows that sea salt and biomass burning are major source of air pollution.
583

Pyrolyse et combustion de solides pulvérisés sous forts gradients thermiques : Caractérisation de la dévolatilisation, des matières particulaires générées et modélisation / Pyrolysis and combustion of pulverized solid fuels at high heating rates : Characterisation of devolatilisation, particulate matter emissions and modelisation

Zellagui, Sami 17 November 2016 (has links)
Le charbon est l’une des ressources fossiles les plus économiques pour la production d’énergie. Cependant, il présente des inconvénients liés à l’impact environnemental lors de sa combustion qui produit CO2, principal gaz à effet de serre, ainsi que d’autres gaz et particules polluants et nocifs pour la santé. Afin de lutter contre ces effets, plusieurs procédés sont envisagés dont l’oxycombustion (possibilité de séquestrer CO2 en sortie du système de combustion) et la co-combustion charbon/biomasse sachant que le bilan carbone est neutre pour la biomasse. Pour caractériser ces procédés, un dispositif expérimental a été développé. Il s’agit d’un four à chute qui permet de reproduire en laboratoire les conditions expérimentales prévalant dans les chaudières industrielles dont une vitesse de chauffe des particules de l’ordre de 104 K s-1. Ce dispositif a permis d’étudier la réaction de dévolatilisation de différents solides pulvérisés (charbons, biomasse) à différentes températures (de 600 à 1400 °C). Pour comparer les procédés de combustion et d’oxycombustion, la dévolatilisation sous N2 (étape préliminaire à la combustion sous air) et sous CO2 (étape préliminaire à l’oxycombustion) a été étudiée pour différents charbons à différentes températures. Les résultats obtenus montrent que l’influence de l’atmosphère gazeuse sur la dévolatilisation du charbon n’est significative que pour des températures supérieures à 1200 °C. L’influence des différentes conditions opératoires sur les émissions de particules (PM2.5) issues de la combustion du charbon et de la biomasse a été évaluée et des corrélations sont mises en évidence entre l’intensité d’émission des particules et la nature du combustible, la température et l’atmosphère gazeuse. Une étude cinétique de la pyrolyse a été effectuée et les paramètres cinétiques correspondants déterminés par modélisation à partir de plusieurs schémas cinétiques réactionnels. / Coal is the most economically attractive fossil fuel and the main resource used for electricity production. However, the main issue with coal combustion is the greenhouse gas as well as other gases and particulates matter leading to environmental and human concerns. In order to reduce the environmental impact of coal utilization, researches are conducted to improve the combustion process and to use other carbon-based fuels. The first approach includes the oxy-fuel combustion that can be coupled with Carbon Capture and Storage process (CCS). The second approach promotes the partial substitution of coal by carbon-neutral fuels, such as biomasses, which are promising fuels.For the evaluation of the application of these technologies, an experimental device was developed. This device is a drop tube furnace (DTF) in which high particle heating rate (approximately 104–105 K s−1) has to be achieved in order to characterize solid fuels under conditions similar to those taking place in power plant furnaces. DTF allowed to investigate pyrolysis reaction involving coal and/or biomass particles at different temperatures (600-1400 °C). The comparison between the oxy-combustion and the conventional air combustion process starts with the investigation of the pyrolysis step. The impact of N2 (for conventional air combustion) and CO2 (for oxy-fuel combustion) atmospheres during pyrolysis of different coals at different temperatures was investigated. Results showed that the coal devolatilization is influenced by the gas under which the fuel devolatilization is carried out (N2 or CO2) only at high temperatures (>1200 °C). The influence of different operating conditions on PM2.5 emission were experimented for coals or biomass, including combustion atmosphere (air or oxy-fuel conditions), particle residence time and temperature. A kinetic study of the pyrolysis was carried out and the corresponding kinetic parameters were determined by modeling from several kinetic reaction schemes.
584

Devenir de la fixation d'azote et export de carbone dans l'océan Pacifique tropical sud-ouest / Fate of dinitrogen fixation and carbon export in the western tropical South Pacific Ocean

Caffin, Mathieu 21 December 2018 (has links)
Ce travail de thèse porte sur la quantification de la diazotrophie et son influence sur les cycles biogéochimiques dans l'océan de surface Pacifique tropical sud-ouest, une région particulièrement sous-échantillonnée à ce jour. Les objectifs de ce travail étaient (1) de quantifier la fixation de N2 et identifier les principaux acteurs de la diazotrophie dans cette région, (2) d’évaluer l'influence de la fixation de N2 sur la production primaire et sur l'export de carbone, (3) d’identifier les voies de transfert de l’azote fixé dans la chaine trophique planctonique.Il a été mis en évidence que la région du Pacifique tropical sud-ouest était un hot spot de fixation de N2. A l'ouest, les eaux oligotrophes des archipels Mélanésiens présentaient des taux de fixation de N2 élevés et la communauté diazotrophe était dominée par Trichodesmium. A l'est, les eaux ultra-oligotrophes de la gyre du Pacifique sud présentaient des taux de fixation de N2 plus faibles et la communauté diazotrophe était dominée par les UCYN-B.Des bilans d'azote montrent que la fixation de N2 contribuait à plus de 90 % des apports d'azote nouveau dans la couche euphotique, et soutenait donc la quasi intégralité de la production primaire nouvelle. L'étude des voies de transfert de l'azote fixé montre qu’entre 7 et 15 % de la fixation de N2 totale était transféré vers les organismes non-diazotrophes.Ces travaux de thèse démontrent que la diazotrophie soutient la pompe biologique dans l'océan Pacifique tropical sud-ouest, et qu'elle peut jouer un rôle déterminant dans la structure des communautés planctoniques et les cycles biogéochimiques du carbone et de l'azote dans les régions oligotrophes. / This PhD thesis focuses on the quantification of diazotrophy and its influence on biogeochemical cycles in the western tropical South Pacific Ocean, a critically under-sampled region so far. The aim of this work is to (1) quantify N2 fixation and identify the main contributors of diazotrophy in this region, (2) assess the influence of N2 fixation on primary production and carbon export, (3) identify transfer pathways of the fixed nitrogen in the planktonic food web.We have found that the western tropical South Pacific Ocean was a hotspot of N2 fixation. In the western part, the oligotrophic waters of the Melanesian archipelago presented high N2 fixation rates and diazotrophes were dominated by Trichodesmium. In the eastern part, the ultra-oligotrophic waters of the South Pacific gyre presented lower N2 fixation rates, and diazotrophs were dominated by UCYN-B.The nitrogen budgets show that N2 fixation contributed to more than 90 % of the of new nitrogen input in the photic layer. The study of the transfer pathways of the fixed nitrogen has shown that 7 to 15 % of total N2 fixation was transferred to non-diazotrophs.This PhD thesis indicates that diazotrophy sustains the biological pump in the western tropical South Pacific Ocean, and can have a critical influence in the planktonic community structure and in biogeochemical cycles of carbon and nitrogen in oligotrophic regions.
585

Identificação dos elementos do Grupo da Platina (EGPs) oriundos de emissão veicular, utilizando as folhas de Tibouchina granulosa (Desr.) Cong. (Melastomataceae) como biomonitor de material particulado (MP) proveniente da emissão dos catalizadores veiculares, na Região Metropolitana de São Paulo (RMSP) / Identification of Platinum Group Elements (PGEs) from vehicle emission, using the leaves of Tibouchina granulosa (Desr.) Cong. (Melastomataceae) as biomonitor of particulate matter (PM) from the emission of vehicular catalysts, in the Metropolitan Region of São Paulo (RMSP)

Zampieri, Maria Cristina Tessari 31 May 2017 (has links)
O desenvolvimento industrial e urbano tem causado aumento mundial das emissões de poluentes atmosféricos. Nas áreas metropolitanas o problema da deterioração da qualidade do ar tem se constituído numa das mais graves ameaças à qualidade de vida dos seus habitantes e os veículos automotores contribuem diretamente com o aumento do material particulado (MP). Neste trabalho foram descritas as etapas metodológicas para validar a Tibouchina granulosa como biomonitor ambiental. Assim, foram abordados a caracterização das folhas, categorização do MP, protocolo de remoção de MP e determinação dos EGPs (Pd, Pt e Rh) na deposição seca das folhas. Para tanto foram realizadas quatro coletas anuais (2011-2014) de folhas, entre os meses de agosto e setembro, em pontos específicos. Os resultados da caracterização mostraram que as folhas permanecem residentes nos ramos por até 6 meses e ocorre o desenvolvimento duas novas folhas por nó a cada mês, indicando que o biomonitoramento pode ser realizado com distribuição temporal e espacial. Os caracteres anatômicos foliares mais relevantes são os tricomas, sendo caracterizados quatro tipos (glandular, adpresso-escabro, base ramificada e estrigoso) que adsorvem o MP. No protocolo de remoção da deposição seca, o número de MP variou de acordo com os diferentes reagentes analíticos utilizados, sendo os mais significativos o ALCONOX&reg e a água régia, que apresentaram valores de remoção na faixa de 99-98% e de 94-99%. As estimativas das incertezas analíticas dos EGPs apresentam valores de uCPt=5% (Pt), uCPd=12% (Pd) e uCRh=5% (Rh) e as incertezas de amostragem, os valores de 57% para o Pd, 24% para a Pt e 27% para o Rh. Portanto, a incerteza expandida foi da Pt U=48%, Pd U=86% e Rh U=9%, a incerteza do Rh apresentou valor mais baixo por ser o elemento minoritário. A elevada sensibilidade do método para determinação dos EGPs apresentou limite de detecção de 0,1 pg g-1 para o Pd, 1,3 pg g-1 para Pt e 0,3 pg g-1 para o Rh e acompanhada boa reprodutibilidade. As concentrações dos EGPs encontradas na deposição seca nos vários pontos de coletas indicaram a clara diferença de acúmulo destes elementos entre o ponto de referência e os locais impactados, sugerindo que a liberação dos EGPS pelos catalisadores veiculares pode ser considerada alta. A evidência da presença dos EGPs na deposição seca foi confirmada por meio da análise da distribuição, que mostrou claramente a similaridade com o material de referência certificado Used Auto Catalystc-2557. As distribuições espaciais dos EGPs foram semelhantes para a Coleta 2, indicando os hot points da RMSP. As concentrações do EGPs foram ordenadas em Pt>Pd>Rh e foram mais baixas no ponto de coleta para controle das amostragens em comparação com os outros locais amostrados. Pode ser concluído que as folhas de T. granulosa foram validadas como biomonitor passivo dos EGPs constituintes de catalisadores veiculares. / Industrial and urban development has caused worldwide increase in emissions air pollutants. In metropolitan areas, the problem of deterioration air quality has been one the most serious threats to quality life its inhabitants, motor vehicles contribute directly increase pollutants. This work describes the methodological steps to validate Tibouchina granulosa as environmental biomonitor, which involved the characterization the leaves, PM categorization, PM removal protocol and determination PGEs in dry deposition, for which four annual collections (2011-2014) were performed between August and September of each year. The of results leaf characters showed that leaves in the branches remain for up to 6 months and the development two new leaf occurs every month. The most relevant foliar characters anatomical are trichomes, being characterized five types. The highest particle concentrations adsorbed to stray trichomes and star-based trichomes. In dry deposition removal protocol, MP number varied according to different analytical reagents used, the most significant being ALCONOX&reg and aqua regia, which presented range removal values of 99-98% and 94-99%, respectively. The estimates analytical uncertainties PGEs show de uCPt=5% (Pt), uCPd=12% (Pd) e uCRh=5% (Rh) and sampling uncertainties values were 57% (Pd), 24% (Pt) and 27% (Rh). Therefore, the expanded uncertainty was Pt u=48%, Pd u=86% e Rh u=9%, in case Rh the uncertainties should be reevaluated by presenting minority values. The high sensitivity of the method for determination of PGEs showed a detection limit of 0.1 pg g-1 for Pd, 1.3 pg g-1 for Pt and 0.3 pg g-1 for Rh and good reproducibility of the results. The concentrations PGEs found in dry deposition in various collection points indicated the clear difference accumulation these elements between reference point and impacted sites, suggesting that release PGEs by the vehicle catalysts can be considered high. Confirming this evidence, through the ternary graphs, which clearly showed similar distributions in the environmental samples and equality with MRC (Used Auto Catalysts). The spatial distributions of Pt, Pd and Rh are similar for Collection 2. Concentrations of the PGEs were ordered in Pt>Pd>Rh and were lower at the collection points for control samplings compared to other sites sampled. In view of the above, it can be concluded that the leaves of T. granulosa can be used as environmental biomonitor of vehicular emissions of PGEs constituent of vehicular catalysts.
586

Efeito da exposição ao material particulado atmosférico no desenvolvimento da lesão pulmonar aguda (LPA) induzida por LPS / Effects of the exposure to atmospheric particulate matter on the development of LPS-induced acute lung injury (ALI)

Costa, Natalia de Souza Xavier 04 September 2015 (has links)
Estudos epidemiológicos e experimentais mostram que a poluição do ar pode causar diversos efeitos adversos na saúde, dentre eles inflamação sistêmica e pulmonar, doenças cardiovasculares e exacerbação de doenças pré-existentes. A síndrome do desconforto respiratório aguda é caraterizada por intenso infiltrado inflamatório, dano na barreira alvéolo-capilar e hipoxemia, e desde a sua descrição em 1967 ainda apresenta elevados índices de mortalidade. O presente estudo tem como objetivos: 1. Avaliar qual o impacto da poluição atmosférica de uma região urbana sobre a progressão da LPA induzida por LPS; e 2. Avaliar se a lesão induzida por LPS é alterada em um indivíduo previamente exposto à poluição atmosférica. Os principais achados relativos ao objetivo 1 mostram que, de uma forma geral, quando há a interação do material particulado fino (MP2,5) anterior à fase aguda da LPA, esta não se desenvolve de forma tão grave. Quanto aos parâmetros inflamatórios, nota-se que, na maioria dos parâmetros, as células inflamatórias e citocinas pró-inflamatórias aumentam no grupo LPS 24 horas, mas não, ou não tanto quanto, no grupo poluição+LPS. Como base nestes resultados podemos hipotetizar que pode ter ocorrido uma alteração do perfil da resposta inflamatória ou imunotoxicidade. Quando observamos os resultados referente ao objetivo 2, nota-se que, o grupo LPS + poluição permanece em um estado inflamatório persistente com número de leucócitos aumentado no lavado bronco-alveolar e níveis elevados de citocinas pró-inflamatórias (IL-1beta, IL-6 e IL-8) no tecido pulmonar, enquanto o grupo LPS 5 semanas tem estes parâmetros mais próximos do grupo controle. Na morfologia tecidual, o grupo LPS + poluição a diminuição do espaço aéreo alveolar e o espessamento septal. É bastante plausível que a poluição do ar dificulte recuperação e o reparo adequado da lesão causada pelo LPS, uma vez que a poluição do ar, e especialmente o material particulado fino, exerce um papel pró-inflamatório contínuo sobre a lesão. Podemos concluir que: o uso do LPS por nebulização é um modelo viável para a reprodução dos parâmetros característicos da lesão pulmonar aguda, a exposição ao material particulado pode alterar o perfil de resposta imediata (24 horas) na lesão pulmonar aguda e pode dificultar a recuperação da lesão. Estudo adicionais são necessários para entender o possível papel da modulação da resposta imunológica nos mecanismos envolvidos nestes processos / Epidemiological and experimental studies show that the air pollution can cause several harmful outcomes to the health, which include systemic and pulmonary inflammation, cardiovascular diseases, and exacerbation of preexisting diseases. The acute respiratory distress syndrome is characterized by intense inflammatory response, alveolo-capillary barrier damage and hypoxemia and since it was described for the first time in 1967 it still has high mortality rates. This study aims to 1. Evaluate the impact of urban air pollution exposure on the acute lung injury progression and 2. Evaluate if the LPS-induced injury is altered in an individual previously exposed to the air pollution. The main findings regarding objective 1 show that when there is an interaction of the particulate matter on the acute phase of LPS-induced injury, the lesion is not as severe as in the group that received only LPS. The inflammatory parameters show that inflammatory cells and pro inflammatory cytokines are increased in the LPS 24 hour, whereas not, or not as much as, in the air pollution + LPS group. Based on these results, we can hypothesize that may have occurred a shift of the inflammatory profile or immunotoxicity. Results of the objective 2 show that the group LPS + air pollution remains in a persistent inflammatory condition with increased leucocytes in BALF and pro inflammatory cytokines (IL-1beta, IL-6 e IL-8) also increased in the lung tissue, while the LPS 5 weeks group shows these parameters levels closer to the control group. The tissue morphology displays a diminished alveolar air space and septal thickening. It is very likely that the air pollution interferes on the adequate LPS-induced lesion recovery and repair, once that the air pollution, specially the fine particulate matter, has a continuous pro-inflammatory role over the lesion. We can conclude that: the use of nebulized LPS is a feasible acute lung injury model; the exposure to the particulate matter could alter the profile of the immediate response (24 hours) of the acute lung injury and it can impair the lesion recovery. Additional studies are necessary to understand the possible role of the immunological response modulation mechanisms involved in these processes
587

Avaliação do risco humano a poluentes atmosféricos por meio de biomonitoramento passivo: um estudo de caso em São Mateus do Sul, Paraná / Human risk assessment for air pollution by passive biomonitoring: a case study in São Mateus do Sul, Paraná, Brazil

Ferreira, Angélica Baganha 29 October 2009 (has links)
Em países em desenvolvimento significantes fontes de poluição do ar podem ocorrer em áreas que não possuem uma qualificada estrutura de medição dos contaminantes. Neste contexto, a simplificação dos métodos de medição de partículas no ambiente, tais como impactador portátil e a acumulação de elementos traço em cascas de árvores podem fornecer informações na determinação da área de influência da fonte emissora de poluição. Neste estudo foram combinadas medidas de acumulação dos elementos traço em cascas de árvores e de partículas finas (diâmetro aerodinâmico inferior a 2,5 m) em filtros para avaliar os possíveis efeitos sobre a saúde da população das emissões de uma indústria de xisto operando em São Mateus do Sul, PR. As análises foram realizadas pela técnica de fluorescência de raios X por dispersão de energia (EDXRF) para determinação dos elementos Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, S, Si, V e Zn nas cascas de árvores e Fe, S e Si no material particulado PM2,5. Dados de saúde da população estudada foram coletados nos prontuários médicos dos pacientes no posto de saúde local. Mapas de distribuição das concentrações dos elementos foram obtidos. Estes mapas foram utilizados para identificar hot spots de poluição, para estimar a mobilidade dos elementos Fe, S e Si presentes no ar, bem como para correlacionar as concentrações destes elementos com dados da saúde da população local. O programa geoestatístico SURFER 8.0 (Golden software Surfer) e o modelo de atenuação foram utilizados nos tratamentos de dados e os softwares STATISTIC 8.0 e SPSS 13.0 utilizados nos testes estatísticos. Os resultados obtidos indicam significante associação entre morbidade respiratória e as emissões industriais. Estes resultados mostram que as emissões da indústria de xisto afetam a saúde dos habitantes da cidade de São Mateus do Sul. Isto também foi demonstrado nas medições das concentrações dos elementos no PM2,5 e na acumulação de elementos traço nas cascas de árvores. A análise fatorial e a análise descritiva, feitas a partir das concentrações determinadas nas cascas de árvores, considerando a direção dos ventos a partir da indústria de xisto sugerem que Fe, S e Si podem ser usados como marcadores da poluição desta indústria. A combinação da caracterização espacial da poluição e dados clínicos mostrou que os efeitos adversos foram significativos (p = 0, 042, ANOVA) para a população com mais de 38 anos. A partir dos resultados obtidos, também podemos concluir que a utilização de cascas de árvores como bioindicador é uma estratégia adequada em estudos sobre impacto ambiental em regiões sem rede convencional de monitoramento da poluição atmosférica / In developing countries significant sources of air pollution may go undetected in areas that do not have qualified structure to measure air contaminants. In this context, simplified methods of measuring ambient particles, such as portable impactors and trace elements accumulate in tree barks, may provide information to identify areas influenced by source emissions. In this study, simplified methods to measure trace elements in tree barks and in fine particles in filters to evaluate the possible health effects of the emissions of a shale oil plant operating in São Mateus do Sul (Paraná, Brazil) were used. These analyses were carried out by energy dispersive X ray fluorescence spectrometry (EDXRF) to determine concentrations of Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, S, Si, V and Zn in tree bark and Fe, S and Si in particulate matter PM2.5. Health data of respiratory diseases of the studied population was obtained from the patient files from the local public health center. The resulting data were evaluated obtaining element concentration distribution maps. These maps were also used to identify hot spots, to estimate element mobility of Fe, S and Si present in the air, as well as, to correlate element concentrations found with health data of the local population. The SURFER geo-statistical software (Golden software Surfer) and the attenuation model of concentration were used to treat these results. For statistical tests, STATISTICÒ 8.0 software and SPSS 13.0 was used. Results obtained indicated significant associations between respiratory morbidity and industrial emissions. Thus the emissions from the shale oil industry affect the health of inhabitants of the city of São Mateus do Sul. This was also demonstrated by measurements of element concentrations in PM2.5 and the accumulation of trace elements in tree barks. Factor analysis and the descriptive analysis (ANOVA) of element concentrations in tree barks downwind of the shale plant suggest that Fe, S and Si may be used as tracers of shale industry pollution. The combination of spatial characterization of pollution and clinical data revealed that adverse effects were significant (p = 0.042, ANOVA) for the population older than 38 years. From the results obtained it was also concluded that the use of tree bark as a bioindicator is an adequate strategy in environmental impact studies in those areas with no conventional network of air pollution monitoring
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Influência da queima da cana-de-açúcar nos níveis de HPAs, nitro-HPAs e oxi-HPAs associados ao aerossol atmosférico / Influence of sugar cane burning in the levels PAH, nitro-PAH and oxy-PAH associated to atmospheric particulate matter

Souza, Kely Ferreira de 01 December 2014 (has links)
Os hidrocarbonetos policíclicos aromáticos (HPAs) e seus derivados nitrados (nitro-HPAs) e oxigenados (oxi-HPAs) são compostos de grande interesse devido seus efeitos deletérios à saúde. Estes compostos são encontrados associados ao material particulado atmosférico e são formados durante a combustão de compostos orgânicos, no caso dos HPAs, e também por reações in situ através dos HPAs precursores, no caso dos nitro- e oxi-HPAs. Para avaliar a influência da queima de cana-de-açucar, amostras de material particulado foram coletadas nas cidades de Ourinhos e Araraquara (Estado de São Paulo), regiões afetadas pela queima de cana-de-açucar. Os filtros carregados foram submetidos à extração por Soxhlet, o extrato orgânico foi fracionado por HPLC e as frações de interesse foram analisadas por cromatografia a gás. Foram investigados 12 HPAs, 7 nitro-HPAs e 3 oxi-HPAs. Na cidade de Ourinhos coletou-se material particulado total (MPT) e material particulado em diferentes tamanhos. Os HPAs e a benzantrona (oxi-HPA) apresentaram concentrações maiores nas partículas menores, ao passo que nitro-HPA e os outros dois oxi-HPAs estudados (9-fluorenona e 9,10-antrona) predominaram nas partículas maiores. Em Araraquara foram coletadas amostras de MPT nos períodos diurno e noturno, e amostras de 24h nos períodos de safra e entressafra. Os HPAs e a benzantrona apresentaram predominância no período noturno, sugerindo que esses compostos devem ter sido provenientes de emissões da queima da cana-de-açucar, ao passo que os outros dois oxi-HPAs estudados (9-fluorenona e 9,10-antraquinona) não apresentaram esse comportamento. Os nitro-HPAs foram detectados em poucas amostras noturnas, provavelmente devido ao processo de remoção destes compostos por fotólise durante o dia. As correlações altas entre HPAs e alguns nitro-HPAs sugerem que tais compostos são provenientes provavelmente das mesmas fontes que os HPAs, embora alguns nitro-HPAs possam também ser formados in situ. Os compostos oxi-HPAs apresentaram correlações com alguns HPAs, mas devem ser também oriundos de outras fontes de emissão além da queima da cana-de-açúcar. De um modo geral, a queima desse tipo de biomassa parece influenciar nos níveis atmosféricos dos compostos estudados. / The polycyclic aromatic hydrocarbons (PAH) and their nitrated (nitro-PAH) and oxygenated (oxy-PAH) derivatives are compound of great interest due to their noxious effects on health. These compounds are found associated to the atmospheric particulate matter and are formed during the organic compound combustion, in case of PAH, and also by in situ reactions through the PAH precursors, in case of nitro- and oxy-PAH. In order to evaluate the sugar cane burning influence, particulate matter samples were collected at Ourinhos and Araraquara cities and submitted to Soxhlet extraction, frationating by HPLC and analized by gas-chromatography. 12 PAH, 11 nitro-PAH and 3 oxy-PAH were investigated. Total particulate matter and particulate matter in different particle sizes were collected at Ourinhos. Particulate matter in different particle sizes presented maximum concentration of PAH and benzanthrone (oxi-PAH) in the smaller particles, while nitro-PAH and the two other oxy-PAH (9-fluorenone and 9,10-anthraquinone) predominated in the larger particles. The sampling of total particulate matter in Araraquara was carried out in daytime and nighttime periods and also 24h sampling in harvest and post-harvest seasons. The PAH and the benzanthrone presented predominance in the nighttime period, suggesting sugar cane burning emissions. Moreover, the other two oxy-PAH (9-fluorenone and 9,10-anthraquinone) did not show that behavior. The nitro-PAH were detected in a few samples, and only at nighttime period in some cases. This is probably due to removal by photolysis during the daytime. The correlations between the compounds suggest a commom source between PAH and some nitro-PAH, although nitro-PAH can also be formed in situ. The oxy-PAH presented some correlations with PAH, but it seems that oxygenated PAH have another emission sources appart from burning. Biomass burning seems to influenciate the PAH and derivative levels in atmosphere.
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Toxoide diftérico: nova roupagem para uma vacina tradicional / Diphtheric toxoid: new clothes for a traditional vaccine

Namur, Jocimara Ambrosio de Moraes 27 November 2007 (has links)
O processo de micrencapsulação de proteínas em microesferas (MS) de PLGA [poli (ácido lactico-co-glicolico)] é fácil de fazer e é uma ferramenta útil para melhorar tanto uma formulação quanto para aumentar a atividade imunológica de vacinas de novas gerações. A MS-PLGA têm caráter adjuvante porque é um sistema particulado e, além disto, controla a liberação do antígeno. O escopo desta tese foi o de dar uma nova roupagem para um antígeno vacinal tradicional e muito bem estudado- o toxoide diftérico (Dtxd). Estudaram-se a produção de MS de tamanho desejado; os mecanismos que controlam danos nas proteínas durante o processo de micrencapsulação; a produção de microesferas com características de liberações em tempos distintos e ensaios biológicos. O tamanho de MS é um determinante fundamental para controlar a velocidade de liberação de um soluto. Para se produzir MS com tamanhos controlados usou-se um desenho fatorial experimental com três fatores distintos e três pontos centrais, para se determinar a influência das variáveis (concentração de poli álcool vinílico; velocidade de agitação e relação fase dispersa/fase contínua) na determinação do tamanho das MS. Foram obtidas MS esféricas e lisas de 4- 15 µm de diâmetro. Estes resultados abrem a possibilidade de se formular PLGA-MS com tamanhos planejados através de um mínimo de experimentos. O mecanismo de danos conformacionais nas proteínas nas várias fases do processo de produção de PLGA-MS é ainda uma questão em aberto. Usaram-se várias técnicas biofísicas (HPLC, espectroscopias no uv, fluorescência e CD) além de ELISA para se testar a interferência dos sais da série de Hofmeister sobre a solubilidade e estabilidade da proteína durante a emulsificação e do contacto com a interface água/cloreto de metileno (primeira etapa do processo de preparação de MS). Estudaram-se também a influência de oligômeros de PLGA e SDS sobre a estrutura da proteína no meio de liberação (etapa de liberação do soluto). A emulsificação de Dtxd na presença de Mg2+ induziu agregação protéica, com exposição de resíduos hidrofóbicos para o meio; variações no ângulo diédrico do S-S proteico e perda de identidade imunológica. Esta agregação foi quase abolida pelo caotrópico SCN- (toxicidade = 30 g/ homem adulto de 70 kg). A conformação \"nativa\" do Dtxd e sua atividade biológica foram protegidas pelo KSCN. Os oligômeros de PLGA e o SDS induziram uma conformação de Dtxd nova. A adição de KSCN na fase aquosa aumentou a eficiência de encapsulação de Dtxd pela PLGA-MS em 20 %. Esta foi a solução mais simples quando comparada com aquelas descritas na literatura. Produziram-se seis formulações diferentes (diferentes massas molares e carboximetilações do PLGA) com pelo menos três cinéticas de liberações distintas. Imunizaram-se camundongos com 5 µg de Dtxd encapsulado em MS-PLGA usando-se dois polímeros de 12 kDa (-COOH livre ou metilado) e um outro de 63 kDa (metilado). O padrão de resposta e a maturidade imunológicas foram medidos por titulações de IgG1 e IgG2a. Mantiveram-se os mesmos padrões de resposta humoral (desejável). Menores quantidades de antígenos foram necessárias para se obter os mesmos benefícios gerados pela vacina tradicional de Dtxd. Aumentaram-se a produção e a seletividade de anticorpos através de duas manipulações simples: a formulação e o tempo da aplicação da dose de reforço. Estes resultados colocam estas formulações na área de vacinas de sucesso uma vez que também foram obtidas memórias imunológicas. / The protein microencapsulation within microspheres (MS) of PLGA (Poly-lactide-co-glycolide) is easy to do and, it is a useful tool to enhance formulation and immunologic performances for new generation vaccines. MS-PLGA has adjuvant character because it is a particulate system and can control the antigen release. The question addressed in this thesis was to give this new dress for the traditional and well studied vaccine antigen - the diphtheria toxoid (Dtxd). The steps of MS control size production; mechanism to control protein damages; MS production with different polymers and biological assay were addressed here. MS size is a primary determinant of solute release velocity. A full factorial experimental design 23 with triplicate at the central point was used to determine the influence of variables (polyvinyl alcohol concentration, stirring velocity and the relationship between dispersed /continuous phase) on MS size. Uniformly spherical and smooth microspheres (4 - 15 µm of diameter) were obtained. These results open the possibility of formulating PLGA microspheres with custom sizes performing a minimum of experiments as required for specific applications. It stills an open question to detail the conformational mechanism of protein damages during the various steps of the PLGA microencapsulation process. Various techniques (HPLC gel filtration, ELISA, Fluorescence, UV and Circular dichroism spectroscopies) were tested on the interference of the Hofmeister ion series over protein solubility and stability during the emulsification and contact with the interface water/CH2Cl2 interface (First step on MS preparation). The interference of SDS and PLGA olygomers over protein structure in the liberation media was also studied (solute liberation step). The Dtxd emulsification in the presence of Mg2+ was followed by protein aggregation, with exposition of hydrophobic residues and changes on the dihedral S-S protein angle and loses on immunological identity. This aggregation is 95% avoided by the chaotropic and little toxic salt KSCN (30g/ adult human of 70 kg). All the \"native\" Dtxd conformation and biological properties were maintained by KSCN. MS with different liberation kinetics profile and different erosion characteristics were obtained by using six different polymers. The SDS and PLGA olygomers exerted a generation of new Dtxd molecular organization. The KSCN increased Dtxd encapsulation within PLGA-MS in more than 20 %. This was the simplest solution used to solve protein aggregation compared with others solutions used in the literature. The six different formulations produced (differing in molar mass and carboxymethylation) produced, at least, three different Dtxd liberation profiles. Mice were primed with 5 µg of Dtxd microencapsulated within MS prepared with 12 kDa (ended carboxymethylated or free PLGA) and with 63 kDa (methylated) PLGA. The response patterns and the immune maturity were measured by IgG1 and IgG2a titrations. The humoral pattern was maintained, but fewer antigens were needed to obtain the same traditional Dtxd vaccine benefits. The simple change on Dtxd-PLGA formulation and timing of the booster enhanced both, antibody production and selectivity. An immunological memory was also obtained, putting so, these formulations in the field of successful vaccine.
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Efeitos hemodinâmicos, inflamatórios e histológicos após a exposição à exaustão do combustível diesel em modelo experimental de hipertensão arterial / Hemodynamic, inflammatory and histological effects after exposure to diesel exhaust in experimental model of arterial hypertension

Almeida, Natalia Madureira de 01 August 2017 (has links)
É plausível que a poluição urbana das grandes metrópoles possa favorecer o desenvolvimento ou mesmo agravar o quadro de hipertensão arterial. A possibilidade de estudar o efeito direto do DE em roedores é extremamente importante e eficaz através do modelo de exposição com o gerador de combustíveis instalado no campus da Faculdade de Medicina da USP. A nossa proposta principal foi avaliar os efeitos hemodinâmicos, aspectos de remodelamento das fibras da matriz extracelular cardíaca e perfil inflamatório pulmonar, visando obter uma conexão entre a exposição ao DE e seus efeitos sistêmicos em 60 ratos hipertensos: SHR (Spontaneously Hypertensive Rats) e 60 normotensos: WKY (Wistar Kyoto). Esses animais foram divididos em 2 grupos: expostos ao ar filtrado e expostos ao diesel e também em 3 tempos de exposição: 15, 30 e 45 dias. Para tanto, foi proposto neste estudo a avaliação dos seguintes parâmetros: Frequência cardíaca, variabilidade da frequência cardíaca, pressão arterial, lavado broncoalveolar, hemograma completo e fatores de coagulação; expressão de marcadores de estresse oxidativo através das análises de citocinas (IL1alfa, IL6, CINC e TNF-alfa) e da enzima superóxido dismutase (SOD) e avaliação qualitativa e quantitativa do tamanho e número de cardiomiócitos e volume de ventrículo esquerdo, através de técnicas estereológicas, e o remodelamento dos elementos fibrilares da matriz extracelular do ventrículo esquerdo dos ratos. Resultados: A exposição DE causou uma diminuição da VFC: SDNN: (p=0,017), RMSSD (p=0,045) nos SHR comparados com WKY todos os tempos de exposição, também foi observado um aumento do tempo de tromboplastina parcial ativada no grupo de 45 dias (p= 0,000), do tempo de protombina nos grupos 30 (p=0,004) e 45 (p=0,000) e uma diminuição da concentração de fibrinogêni no grupo 15 dias (p=0,020). Houve um aumento da concentração de plaquetas nos grupos 30 (p=0,000) e 45 dias (p=0,004) e hipertrofia ventricular esquerda, no grupo 45 dias (p=0,000) para os animais SHR quando comparado aos animais WKY expostos ao DE. Notamos um aumento das fibras colagênicas no grupo 45 dias (p= 0,000) e aumento de volume de cardiomiócitos nos grupos 15 (p= 0,000) 30 (p= 0,000) e 45 dias (p=0,023) em ratos SHR expostos ao DE comparados aos WKY. Também ocorreu um aumento da produção das citocinas IL1beta nos grupos 30 (p=0,002) e 45 dias (p=0,000) e TNF-alfa nos grupos 30 (p=0,012) e 45 dias (p=0,003) e CINC no grupo 45 dias (p= 0,021) em ratos SHR expostos ao DE. Comparando as linhagens, os ratos SHR expostos ao DE apresentaram maiores valores de IL1? no grupo 45 dias (p=0,043). Os valores de SOD foram menores em ratos SHR no grupo 30 dias (p= 0,016) de exposição ao DE. Nos ratos SHR, expostos ao DE, nos grupos 30 (p= 0,008) e 45 dias (p= 0,002), notou-se um aumento de macrófagos no lavado broncoalveolar. Conclusões: De acordo com esses achados, notamos que a exposição ao diesel promove inflamação pulmonar e sistêmica, desbalanço do sistema nervoso autônomo e remodelamento do miocárdio em animais hipertensos. Estes fatores poderão promover ou agravar os quadros de hipertensão arterial sistêmica em indivíduos suscetíveis e expostos a poluição urbana / The expousure to DEP (Diesel Exhaust Particles) it is related to oxidative stress, it is possible that air pollution of the cities may aggravate hypertension. The possibility of studying the direct effects of DEP in rats it is important and effective through intoxication model with the fuel generator installed in Medicine University of USP. The fuel generator system possible to evaluate the toxicological risks to the use of diesel. The study allowed hemodynamics effects, remodeling of left ventricle, pulmonary inflammation, having the connection between exposure to DEP and your systemic effects. It was evaluated: heart rate, heart rate variability, blood pressure, bronchoalveolar lavage, complete blood count and coagulation factors, citokines evaluation (IL1beta, 1L6, CINC and TNF-alpha) and SOD, vascular endothelium peribronchial vessels in bronchoalveolar lavage through immunoassay and qualitative and quantitative remodeling of extracellular matrix elements in left ventricle of 60 rats hypertensive: SHR (Spontaneosly Hypertensive Rtas) and 60 normotensive WKY (Wistar Kyoto). This animals were divided in 2 groups: exposed to filtred air and exposed to diesel and to 3 times exposures groups: 15, 30 and 45 days. Results: The DE exposure caused decreased in HRV: SDNN: (p=0,017), RMSSD (p=0,045) in SHR in all times of exposure, increased in the values of coagulation factors in SHR exposed to DE after 30 (p=0,001) and 45 days (p=0,000), an aggregation of platelets after 30 (p=0,000) and 45 days (p=0,004), and left ventricular hypertrophy after 45 days (p=0,000) in SHR exposed to DE. We noticed an increase in colagenous fibers after 45 days (p= 0,000) in SHR rats exposed to DE and increased volume of cardiomyocytes after 15 (p= 0,000), 30 (p= 0,000) and 45 days (p=0,023). A increased in citokines production IL1beta after 30 (p=0,002) and 45 days (p=0,000) e TNF-alpha after 30 (p=0,012) and 45 days (p=0,003) and CINC after 45 days (p= 0,021) in SHR exposed to DE. Comparing the lineages, the SHR exposed to DE presented increased in values of IL1beta after 45 days (p=0,043). The SOD values increased in SHR after 30 days (p= 0,016) of exposure to DE. In SHR exposed to DE presented increased after de 30 (p= 0,008) and 45 days (p= 0,002), in values of macrophages. Conclutions: According to these findings, we noticed that exposure to diesel can promote pulmonary and systemic inflammation, imbalance the autonomic nervous system and remodeling the myocardium. These factors may promote or worsen hypertension in susceptible individuals exposed to urban pollution

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