Dissertation (Ph.D.)--University of South Florida, 2006. / Title from PDF of title page. Document formatted into pages; contains 153 pages. Includes vita. Includes bibliographical references.

Thesis (Ph. D.)--Ohio State University, 2007. / Title from first page of PDF file. Includes bibliographical references (p. 151-169).

No description available.

Orientador: Luiz Fernando Costa Nascimento / Coorientadora: Andrea Paula Peneluppi de Medeiros / Banca: João Andrade de Carvalho Junior / Banca: Gregório Lorenzo Acácio / Resumo: Este trabalho tem por objetivo avaliar a exposição da gestante aos poluentes do ar em sua somatória de 30, 60 e 90 dias anteriores ao parto, e analisar o efeito desses poluentes sobre o baixo peso ao nascer. Trata-se de estudo longitudinal, com dados todos os nascidos vivos de mulheres residentes no município de São José dos Campos no ano de 2013, excluindo os com peso menor de 500 gramas, os partos ocorridos até 36 semanas e 6/7 de gestação, os partos gemelares e trigemelares, bem como os fetos com mal-formação congênita. A variável dependente, peso ao nascer, foi categorizada como desfavorável ≤ 2500 g e favorável > 2500 g, e as independentes foram idade materna, estado civil, escolaridade, número de consultas e mês do início do pré-natal. Os poluentes do ar analisados foram SO2, PM10, CO, NO2 e O3 com dados acumulados de 30, 60 e 90 dias anteriores ao parto. A análise utilizada foi o modelo de regressão logística hierarquizada em três níveis: distal, intermediário e proximal. Foram 9336 nascidos vivos, sendo incluídos 8028 (86,0%) que atenderam aos critérios de inclusão. As variáveis significativas do nível distal foram idade materna e estado civil, do nível intermediário o número de consultas e no proximal a exposição materna ao O3 com 60 dias (OR= 1,10) e 90 dias (OR= 1,12) anteriores ao parto, sendo para o sexo feminino a associação ao O3 se deu no segundo quartil (OR = 1,61) e no quarto quartil (OR = 1,16) e para o sexo masculino com 90 dias no terceiro quartil (OR = 1... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The purpose of this study is to evaluate the exposure of pregnant women to air pollutants in their sum of 30, 60 and 90 days prior to birth, and to analyze the effect of these pollutants on low birth weight. This is a longitudinal study, with data on all live births of women living in the São José dos Campos City in 2013, excluding newborns under 22 complete weeks of gestation and those weighing less than 500 g, births under to 36 weeks and 6/7, twin and trigeminal gestations, and fetuses with congenital malformation. The dependent variable was birth weight and was categorized as unfavorable ≤ 2500 g and favorable> 2500 g, and the independent variables were maternal age, marital status, schooling, number of prenatal visits and month of prenatal initiation. The air pollutants analyzed were SO2, PM10, CO, NO2 and O3 with cumulative data of 30, 60 and 90 days prior to labor. The analysis used was the hierarchical logistic regression model at three levels: distal, intermediate and proximal. There were 9336 live births and 8028 (86.0%) that filed the inclusion criteria. The significant variables of the distal level were maternal age and marital status, at the intermediate level the number of prenatal visits. In the proximal level the maternal exposure to O3 with 60 days (OR = 1.10) and 90 days (OR = 1.12) prior to delivery, being to females sex the association of the O3 was in the second quartile (OR = 1.61) and in the fourth quartile (OR = 1.16) and for males sex with 90 days in the third quartile (OR = 1, 35). This study allowed the identification of the association only with the exposure of the pregnant woman to the O3 for the accumulated 60 and 90 days before delivery with low birth weight, and for the other pollutants there was no statistical significance / Mestre

Despite the importance of muscle in the development of type 2 diabetes, few studies have investigated the effect of polychlorinated biphenyls (PCBs) on muscle energy metabolism. Previous results from our lab suggested that PCB126 exposure induced an indirect negative effect on muscle mitochondrial function. Since PCBs are stored in adipose tissue, we hypothesized that PCB126 alters adipokine secretion which in turn affects muscle metabolism. Objectives. Study the adipose-to-muscle communication in PCB126-induced metabolic defects. Methods. Communication between adipocytes and myotubes was reproduced by exposing C2C12 or mouse primary myotubes to the conditioned medium (CM) of 3T3L1 adipocytes exposed to environmentally relevant PCB126 levels. Results. PCB126 significantly increased adipokine secretion and decreased mitochondrial function, glucose uptake and glycolysis in insulin resistant (IR) but not in insulin sensitive 3T3L1. However, exposure of myotubes to CM of IR 3T3L1 only decreased glucose uptake and insulin sensitivity, without altering myotubes glycolysis or mitochondrial function. Conclusion. Our results suggest that the increased adipokine secretion by adipocytes could explain the decreased muscle glucose uptake and insulin sensitivity when exposed to PCB126.

Due to environmental concerns, most of persistent organic pollutants (POPs) have been eliminated or reduced in production and use; however, due to their great persistency, POPs are expected still to be found in the environment long after their use has ceased. Although, in recent years, POPs have rarely been detected in river water in the United Kingdom (UK), their concentrations in fish (biota) and sediment are expected to be notable due to their lipophilicity and bioaccumulation; however, there is a lack of information and data to understand the current contamination of POPs in catchments and evaluate their potential risk to the environment and ecosystem. This thesis describes the application of mathematical modelling approaches to (i) predict the current distribution and concentration of POPs in catchments, (ii) evaluate the influence of climate change and extreme weather conditions on the fate of POPs, and (iii) provide guidelines to inform decision-making on managing the potential risks of POPs in river basins. The modelling studies have mainly focused on polychlorinated biphenyls (PCBs). The River Thames catchment was chosen as the study area. The Fugacity level III model was initially used to describe the general distribution of PCBs between different compartments; it was predicted that the greatest mass of PCBs remain in the soil, but the fish and sediments represent compartments with the highest PCB concentrations. The contamination of PCBs in Thames fish was estimated to exceed the unrestricted consumption thresholds of 5.9 μg/kg for ∑PCBs set by the U.S. Environmental Protection Agency (EPA); no current EU Environmental Quality Standards (EQS) are available for PCBs in fish. It was indicated that the PCBs in fish could be linked to PCB contamination in sediment, which was predicted to be about three times higher than the fish concentrations, but insufficient observed data of PCBs in Thames fish and sediment are available to validate the results. In order to address this limitation in observed data, fish and sediment sampling and chemical analysis were carried out for the presence of POPs. In addition to PCBs, the measured results for hexachlorobenzene (HCB) and polybrominated diphenyl ethers (PBDEs) in Thames fish and sediment were assessed. Although the observed fish- and sediment concentrations of the chemicals appear quite variable, when normalised to organic carbon the levels in sediment, they were comparable to the fish lipid normalised concentrations. Using the temperature and rainfall data forecasts in the UK Climate Projections 2009 (UKCP09), climate change scenarios were established and assessed in the fugacity modelling. The modelling results suggested a modest influence of climate change on PCB fate over the next 80 years. The most significant result was a tendency, in the Thames catchment, for climate change to enhance the evaporation of PCBs from soil to air. While the fugacity model successfully simulated the distribution and fate of PCBs, we used greatly simplified representations of climate, hydrology and biogeochemical processes of the catchment: to have a deeper understanding, a newly developed dynamic hydrobiogeochemical transport model - the Integrated Catchment Contaminants model (INCAContaminants) was applied. Using additional information about weather, river flows and water chemistry, the INCA-Contaminants model provided new insights into the behaviour of contaminants in the catchment; this led to a better representation of PCB contamination in sediment. In addition, INCA demonstrated the important impact of short-term weather variation on PCB movement through the environment. It was shown that PCBs contamination in Thames sediment was greatly disturbed by the severe flooding that occurred in early 2014. This thesis presents the application of the INCA model to assess - in addition to POPs - the behaviour of metaldehyde in the River Thames catchment. Metaldehyde is a type of pesticide used mainly to kill snails and slugs. Its application in agricultural areas within the catchment area has in recent years caused severe problems with drinking water supply. The INCA model has proved to be an effective tool for simulating the transport of metaldehyde in the catchment, predicting observed metaldehyde concentrations at multiple locations in the River Thames; this is the first time that a dynamic modelling approach has been used to predict the behaviour of metaldehyde in river basins. Modelling results showed that high concentrations of metaldehyde in the river system are a direct consequence of excessive application rates. In this thesis, a simple decision-support tool was derived from modelling results, based on variable application rates and application areas. This decision-support tool is now being used by Thames Water to help control peak concentrations of metaldehyde at key water supply locations.

[pt] O presente trabalho realiza a integração entre a solução computacional por elementos finitos para as equações que descrevem s condições elétricas reinantes no espaço interletrodos de um Precipitador Eletrostático (PE) fio-placas e dados experimentais obtidos em um canal de precipitação com a mesma forma geométrica. A integração acima é necessária à qualquer tentativa de projeto teórico de um PE, uma vez que tais equações exigem para o seu fechamento a introdução de um parâmetro denominado mobilidade de portador de carga, para o qual não se tem possibilidade de previsão teórica de valor, devido ao grande número de variáveis físicas que podem influenciá-lo. Além disso, as soluções teóricas em geral são obtidas dentro de uma modelagem que supõe a existência de um canal de placas paralelas provido de alguns eletrodos emissores consecutivamente dispostos na linha central do canal de precipitação. Essa redução da situação real à uma situação simplificada impede a observação crucial de que o fenômeno de precipitação eletrostática em um PE é um fenômeno que sofre uma variação física contínua ao longo da região de precipitação, à medida que material particulado vai sendo retirado da carga em escoamento. Qualquer solução teórica acaba sendo de pouca utilidade ao projeto de um canal de precipitação completo. No presente trabalho estamos propondo a utilização de um equipamento laboratorial que permite a medição de correntes elétricas entregues por portadores de carga em áreas discretas das placas planas aterradas em um escoamento de ar com cargas de particulados sólidos, dentro de um canal de precipitação com um número razoável de eletrodos emissores. A partir das correntes de placa medida é determinada um valor para mobilidade elétrica associada a cada região longitudinal da secção de precipitação. Essa mobilidade elétrica é então adimensionalizada em termos de alguns parâmetros, sendo que no presente representa a profundidade de penetração no campo de precipitação. Por fim utiliza-se a mobilidade elétrica adimensional como predição para as condições elétricas à serem esperadas em diferentes valores de tensão aplicada, sendo sugerido seu uso como ferramenta auxiliar no projeto de precipitadores eletrostáticos. Foi observado que o campo elétrico originado em cada um dos eletrodos apresenta uma ação alternada de aceleração ou desaceleração sobre o material particulado em suspensão, respectivamente nas regiões imediatamente após, ou antes, de cada eletrodo emissor, relativamente à direção do escoamento. Esse fenômeno físico, não mencionado em qualquer uma das referencias do presente trabalho, foi denominado aqui efeito de alternância e tem uma importância fundamental com relação ao uso da mobilidade adimensional no projeto de PÉS e também quanto às possibilidades de otimização de PÉS já em operação. / [en] This work integrates a numerical solution, obtained by finite elements and characteristic methods applied to the governing equations of the electrical conditions in the inter-electrodes region of a wire-plate Eletrostatic Precipitador (EP), with data acquired in a precipitation channel with the same geometric form. The integration above mentioned is demanded by any attempt of an analytical project of an EP due to the introduction of a paramenter, denominated mobility of the charge carriers, in the closure of the governing equations. Further, the analytical solutions are in general obtained under the modeling of a precipitation region provided with a small number of corona wires, just enough to give simetry considerations. It must be kept in mind that in an EP each channel is provided with dozens of corona wires. The simplification above interdicts the crucial observation that the precipitation phenomena in an EP suffers physical changes along the axial length of the channel, due to the continuos wuthdrawing of particulate material from the total load. Solutions apropiated to a single region are so not very useful to the project of an entire channel. In this work we present an experimental apparatus which allows the measurement of eletric currents in discrete areas of the colleting plates. The apparatus is provided with a number of corona wires that can simulate a channel of an EP. Using the values of the currents measured at each of thediscrete plates it is obtained a value for the electrical mobility associated to discrete regions longitudinally with the flow. A dimensionless mobility is then obtained in terms of some parameters. In the present work these parameters were restricted to the applied potential. It is then suggested how an EP projectist could use the method as a tool for helping in the design process. It was observed that the eletric field originated in each of the corona wires acts alternatedely accelerating or desaccelerating the charged particulate load, pespectively in the regions immediately after or before each corona wire, with respect to the main direction of the flow. This physical phenomena, not mentioned in any of the references of the present work, was denomitade here as alternation effect, and has fundamental importance in the use of the dimensionless mobility as a project tool and also in the possibilities of upgrading Eps already in use.

Dans cette thèse, nous présentons l’étude et la réalisation de micro-capteurs pour les systèmes de gestion des risques naturels. Le cahier des charges était centré sur les possibilités de concevoir des capteurs de polluants pour la surveillance des zones lagunaires dans le sud montpelliérain. Ces capteurs devaient être conçus dans une démarche « faible coût », résistant aux contraintes du milieu et pouvant communiquer et temps réel. Le premier chapitre s’appuie sur une étude bibliographique des différentes méthodes de mesures qui peuvent être utilisées pour faire de la détection de polluants et des matériaux potentiels pour réaliser le capteur. La technique de mesure la plus appropriée pour répondre aux deux premiers points du cahier des charges s’appuie sur la réalisation de transducteurs acoustiques à base de PZT en envisageant un processus technologique basé sur la technique de sérigraphie. Après avoir justifié notre choix de la technique de dépôt par sérigraphie, nous avons détaillé dans le second chapitre le processus technologique, en commençant par la réalisation de l’encre PZT, puis par le dessin des masques et pour finir nous avons détaillé les étapes de dépôt et de fonctionnalisation des transducteurs sur substrat d’alumine et sans substrat. A partir de ces premières réalisations, nous avons présenté les moyens et outils de caractérisation nécessaires pour pouvoir évaluer les différentes étapes du processus technologique mis en place, avec une attention particulière portée sur la qualité du matériau PZT et sur ses propriétés piézoélectriques. Il s’agit d’une part d’études morphologiques (images MEB, profilomètre) et structurelles (diffraction X, EDX) et d’autre part de la mesure des grandeurs piézoélectriques et diélectriques (piézomètre, analyses spectrales et d’impédances). Dans le troisième chapitre nous avons abordé le volet système de cette étude, avec la réalisation de prototypes basés sur les transducteurs sérigraphiés développés au chapitre 2. Les capteurs réalisés ont été testés et étalonnés avec des solutions d’éthanol et de toluène. Pour cela les capteurs sérigraphiés ont été testés sur des bancs expérimentaux afin de valider la technique de la mesure du temps de vol des ondes acoustiques. Dans l’optique de la miniaturisation et de l’intégration du système nous avons mis en place une électronique de commande embarquée à l’aide d’un module dédié. Enfin, pour pouvoir affiner les mesures, nous avons vu que nous pouvions envisager de croiser/corréler plusieurs paramètres. C’est ainsi que nous avons développé un capteur sérigraphié pour la mesure de la conductivité électrique en milieu aquatique. A partir des premiers résultats expérimentaux obtenus nous avons pu valider le principe de la méthode. Dans le quatrième et dernier chapitre de ce manuscrit, nous avons présenté les toutes premières études et réalisations sur la technologie LTCC. En reprenant les paramètres du processus utilisés lors des dépôts sur substrat d’alumine, nous avons réalisé et caractérisé des transducteurs déposés sur une feuille de céramique LTCC. Les premières caractérisations morphologiques et piézoélectriques sont encourageantes et les premiers tests acoustiques ont montré que la génération d’ondes acoustiques était tout à fait possible et qu’une utilisation en vue de la réalisation de capteurs de polluants était envisageable avec cette technologie. Enfin, nous avons pu réaliser une première structure 3D intégrant une cavité d’analyse. Là encore les débuts sont très prometteurs même s’il reste encore beaucoup de travail de « réglage » pour améliorer cette technologie. De plus, cette première réalisation 3D, ouvre de nombreuses perspectives au niveau de l’équipe en vue du développement de nouveaux capteurs. / In this thesis, we introduce the study and implementation of micro-sensors for natural risk management systems. The specification focused on the possibilities to develop a pollutant sensor capable of detecting the presence of hydrocarbons in the lagoon environments of southern Montpellier.These sensors should be designed in a "low cost" gait, resistant to environmental constraints and able to communicate in real time. The first chapter is based on a bibliographical study of the different methods of measurement that can be used for the detection of pollutants and potential materials for making the sensor. The most suitable measurement technology to answer the first two points of the specification is based on the implementation of acoustic transducers made from PZT with a technological process using the screen-printing technique. After justifying our choice of screen-printing deposition technique, we have detailed in the second chapter the technological process: first with the achievement of PZT ink, then with the masks design, and finally with the steps deposition and functionalization of transducers on alumina substrate and without substrate. From these first achievements, we have submitted the means and characterization tools needed to evaluate the different steps of the technological process set up with a focus on the quality of the PZT material and its piezoelectric properties. It is first about morphological (SEM images, profilometer) and structural (XRD, EDX) studies, and then about the measurement of piezoelectric and dielectric values (piezometer, spectral and impedance analyses). In the third chapter we discussed the sensor, with the production of prototypes based on screen-printed transducers developed in Chapter 2. The sensors were tested and calibrated with solutions of ethanol and toluene. For this, the screen-printed sensors were tested in experimental benches to validate the measurement technique of the acoustic waves time of flight. In view of the miniaturization and the integration of the system, we have set an electronic control board with a dedicated module. Finally in order to improve the measurements, we have shown that we could consider crossing/correlating several parameters. Thus, we have developed a screen-printed sensor for the measurement of the electrical conductivity in aquatic environment. From the first experimental results we validated the principle of the method. In the fourth and final chapter of this manuscript, we presented the first studies and achievements on the LTCC technology. By repeating the process parameters used during deposition on alumina substrate, we realized and characterized transducers placed on on a LTCC ceramic sheet. The first morphological and piezoelectric characterizations are encouraging, and the first acoustic tests have shown that the generations of acoustic waves, and a use for the production of sensors of pollutants were possible with this technology. Finally we have been able to achieve a first 3D structure incorporating an analysis cavity. Here again, results are very encouraging, although "adjustments" are needed to improve the technology. Also this 3D realization opens up many opportunities for the team to develop new sensors.

Submitted by Jos? Henrique Henrique (jose.neves@ufvjm.edu.br) on 2018-03-08T18:31:35Z No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) jose_geraldo_mendes_castro_junior.pdf: 20723597 bytes, checksum: f867ab4f1cb9235c24c8c6d16d42c22c (MD5) / Approved for entry into archive by Rodrigo Martins Cruz (rodrigo.cruz@ufvjm.edu.br) on 2018-03-09T18:46:17Z (GMT) No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) jose_geraldo_mendes_castro_junior.pdf: 20723597 bytes, checksum: f867ab4f1cb9235c24c8c6d16d42c22c (MD5) / Made available in DSpace on 2018-03-09T18:46:17Z (GMT). No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) jose_geraldo_mendes_castro_junior.pdf: 20723597 bytes, checksum: f867ab4f1cb9235c24c8c6d16d42c22c (MD5) Previous issue date: 2017 / Eletrodos de di?xido de chumbo (PbO2) suportados sobre tecido de carbono e tela de a?o inoxid?vel foram utilizados na degrada??o eletroqu?mica dos f?rmacos paracetamol (PCT) e dipirona (DPN), utilizando-se uma c?lula eletroqu?mica do tipo eletr?lito polim?rico s?lido (EPS) munida de eletrodos perme?veis a fluidos (EPFs). Todos os estudos foram conduzidos na condi??o de batelada empregando-se a ?gua livre de eletr?litos. Os estudos eletroqu?micos de degrada??o dos f?rmacos foram conduzidos em fun??o da densidade de corrente aparente (jap) (ex., 5, 10, 20, 100, 150 e 200 mA cm-2) e da concentra??o inicial (ex., 10, 30 e 50 mg L 1). As amostras tratadas foram analisadas pelas t?cnicas de espectrofotometria na regi?o do UVVis, cromatografia l?quida de alta efici?ncia (CLAE) e demanda qu?mica de oxig?nio (DQO). Verificou-se para os diferentes casos envolvendo as baixas densidades de corrente que a remo??o das bandas de absor??o no UV-Vis, a remo??o da concentra??o dos f?rmacos (CLAE) e a redu??o da DQO (grau de mineraliza??o) n?o foram significativos. Contrariamente, no caso das elevadas densidades de corrente evidenciou-se uma significante melhora na degrada??o dos f?rmacos em decorr?ncia da atua??o do oz?nio gerado eletroquimicamente. Os melhores resultados foram obtidos para baixas concentra??es dos f?rmacos. Redu??es superiores a 95 % de DQO para o PCT e superiores a 75 % para a DPN foram obtidas. Eletrodos de PbO2 dopados com n?quel (ex., Ni-PbO2) suportados sobre tecido de carbono e tela de a?o inoxid?vel foram confeccionados e caracterizados. A an?lise de microscopia eletr?nica de varredura (MEV) revelou o aparecimento de defeitos superficiais, com a varia??o da concentra??o nominal do Ni no banho eletrol?tico utilizado no preparo do eletrodo por eletrodeposi??o. An?lises de difratometria de raios-X (DRX) corroboraram os resultados de MEV revelando, em alguns casos, picos mais alargados e de menor intensidade (ex., redu??o no tamanho m?dio dos cristalitos) com a varia??o da concentra??o nominal do Ni, indicando assim uma interfer?ncia no processo de eletrodeposi??o do PbO2. Curvas de polariza??o em condi??es quaseestacion?rias foram obtidas para o processo eletr?dico da rea??o de desprendimento de oxig?nio (RDO) sendo verificado que n?o houve influ?ncia significativa do dopante sobre esta rea??o, a qual ocorre em paralelo ao processo de degrada??o oxidativa dos f?rmacos. Verificou-se que a produ??o de oz?nio foi ligeiramente favorecida em algumas concentra??es do dopante e em altas densidades de corrente. No entanto, n?o foi verificada influ?ncia significativa sobre o grau de mineraliza??o dos f?rmacos PCT e DPN mediante uso de eletrodos dopados com Ni. / Disserta??o (Mestrado) ? Programa de P?s-Gradua??o em Qu?mica, Universidade Federal dos Vales do Jequitinhonha e Mucuri, 2017. / Lead dioxide (PbO2) electrodes supported on carbon cloth and stainless-steel mesh substrates were used in the electrochemical degradation of the drugs paracetamol (PCT) and dipyrone (DPN), using a solid polymer electrolyte electrochemical cell (SPE) having fluid-permeable electrodes (FPEs). All studies were conducted in batch condition using the electrolyte-free water. The electrochemical degradation of the drugs was accomplished as a function of the apparent current density (ex., 5, 10, 20, 100, 150 and 200 mA cm-2) and the initial concentration (ex., 10, 30 and 50 mg L-1). The treated samples were analyzed using the UV-Vis spectrophotometry technique, the high-performance liquid chromatography (HPLC), as well as the chemical oxygen demand (COD). For the different cases involving the application of low current density values, it was not verified significant changes accounting for the removal of the UV-Vis absorption band, the drug concentration (HPLC), and the COD decrease (ex., the degree of mineralization). In contrast, in the case of high current densities, a significant improvement in the degradation of the drugs was evidenced as a result of the influence of the electrochemically generated ozone. The best findings were obtained for low drug concentrations. Reductions of above 95% COD for PCT and above 75% for DPN were obtained. Nickel-doped PbO2 electrodes (ex., Ni-PbO2) supported on carbon cloth and stainlesssteel mesh were fabricated and characterized. Scanning electron microscopy (SEM) revealed the appearance of surface defects with a reduction in crystal size with the different Ni concentration in the electrolytic bath used to prepare the electrode by electrodeposition. X-ray diffraction (XRD) analyzes corroborated with the SEM results revealing the formation of broader peaks with lower intensity, in some cases, (ex., reduction in the average crystallite size) with the variation of the nominal dopant concentration in the electrolytic bath, thus indicating an interference in the electrodeposition process for PbO2. Quasi-stationary polarization curves were obtained for the electrode process of the oxygen evolution reaction (OER) and it was verified that there was no significant influence of the dopant on this reaction, which occurs in parallel to the process comprising the oxidative degradation of the drugs. It was found that the ozone generation was slightly favored in some concentrations of the dopant and in higher current densities. However, no significant influence was verified on the degree of mineralization of PCT and DPN by the use of Ni-PbO2 electrodes.

Este trabalho versa sobre a possibilidade de utilização da dispersão de poluentes como fator limitante à ocupação territorial, sendo esta uma ferramenta de avaliação para o Plano Diretor. O estudo de caso faz referência ao município de Porto Alegre, localizado no Estado do Rio Grande do Sul, Brasil. A partir de uma revisão da literatura que aborda a emissão de partículas de gases tóxicos para a atmosfera em centros urbanos, adotaram-se critérios para a escolha de determinadas variáveis meteorológicas, de monitoramento da qualidade do ar, de uma possível fonte emissora e zonas de uso em Porto Alegre. Primeiramente, fez-se a escolha das unidades amostrais para qualidade do ar do município, sendo esta etapa seguida da obtenção dos dados dos critérios anteriormente citados junto aos órgãos competentes, acompanhada por análises estatísticas das diferentes variáveis. Na segunda parte do trabalho fez-se a comparação entre os doze meses do ano por meio de representação gráfica e constatou-se que os níveis de emissão de poluentes nos três diferentes pontos amostrais atingiram seu pico máximo no inverno, quando o vento predominante no município é sudeste, e que sua velocidade varia entre a máxima de 2,46 m/s e a mínima de 1,20 m/s, ainda que o mapa que divide o município de Porto Alegre em zonas de uso não levasse em conta a dispersão dos poluentes (sua direção e os efeitos sobre a saúde da população). Concluiu-se que, mesmo sem a utilização de um software avançado, o trabalho conseguiu mostrar a importância de se utilizar a poluição atmosférica como um condicionante no processo de ocupação urbana no município, isso em decorrência das distâncias em relação ao tempo em que os poluentes atingem o receptor e suas concentrações. Por fim, constata-se que a poluição atmosférica não condiciona a ocupação do espaço urbano, mesmo com uma legislação vigente no município, sendo a ocupação do território urbano basicamente influenciada pelo mercado imobiliário em Porto Alegre, RS. / This work deals with the possibility of using the dispersion of pollutants as a limiting factor to the territorial occupation, which is a tool for evaluating the Master Plan. The case study refers to the municipality of Porto Alegre, located in the State of Rio Grande do Sul, Brazil. From the literature review that addresses the particle emission of toxic gases into the atmosphere in urban centers, were adopted criteria for the choice of certain meteorological variables, monitoring of air quality, a possible source of authority and areas of use in Porto Alegre. First became the choice of samples to air quality in the city, and then this step of obtaining data of the criteria mentioned above with the competent organs, accompanied by statistical analysis of the different variables. In the second part of the work, made a comparison between the twelve months of the year by means of graphic representation. It was found that the emission levels of pollutants in three different sample points reached its peak in the winter when the prevailing wind in the city of Porto Alegre is southeast and its velocity varies between the peak of 2.46 m / s and a minimum,1.20m / s, although the map that divides the municipality into zones of use study did not take into account the dispersion of pollutants (its direction and the effects on the health of the population). We conclude that, even without the use of advanced software, the work was able to show the importance of using air pollution as a determinant in the process of urban settlement in the municipality, that due to the distances from the time that the pollutants reach and concentrations. Finally we note that the city is not prepared enough to deal with pollutants that are emitted daily by the different sources of emissions, even with a legislation that deals with the issue, because often they are influenced by the housing market of Porto Alegre/RS.