Este trabalho teve como objetivo a identificação e quantificação das fontes do Material Particulado fino (MP2,5) da Região Metropolitana de Porto Alegre (RMPA), em especial, as fontes veiculares. Foram utilizadas amostras coletadas diariamente durante 24 horas, entre junho/2007 a fevereiro/2009 na Universidade Federal de Ciências da Saúde de Porto Alegre, próxima a vias de intenso tráfego. As amostras foram analisadas para determinação da concentração em massa, composição elementar e iônica do MP2,5. A concentração média do particulado fino durante o experimento foi de 13,4 µg m-3 e do Black Carbon foi de 3,8 µg m-3. Os elementos-traço S, K e Fe destacaram-se com concentrações mais elevadas. Através de Modelagem Receptora (Análise de Fatores AF e Fatoração de Matriz Positiva, Positive Matrix Factorization PMF), identificaram-se as possíveis fontes de MP2,5 da região. A utilização do PMF, modelo multivariado mais avançado, embora não tenha mostrado uma clara separação das fontes, possibilitou uma quantificação mais acurada das fontes identificadas. Por essa metodologia foram identificadas como fontes do MP2,5 as emissões veiculares, a ressuspensão do solo e as indústrias. Para ambos os modelos, a principal fonte identificada está relacionada com as emissões veiculares, respondendo por aproximadamente 50 % da massa do particulado fino. Dos resultados obtidos com o PMF, o solo tem uma pequena participação (2,5 %). A dificuldade na identificação das fontes pode ser atribuída a falta de medida de traçadores específicos dos combustíveis utilizados no setor de transporte e as limitações analíticas do sistema de Fluorescência de Raio-X, que possui baixos limites de detecção para importantes traçadores de fontes móveis e industriais como V, Ni, Cr, Se e Cu. / The aim of this work was to identify and quantify the sources of fine particles in the Metropolitan Region of Porto Alegre, specially the vehicular sources. PM2.5 samples collected daily for 24 hours between june/2007 to february/2009 at the Universidade Federal de Ciências da Saúde de Porto Alegre, near heavy traffic routes. The samples were analyzed for determination of mass concentration, elemental and ionic composition. The average concentration of fine particulate matter during the experiment was 13.4 µg m-3 and Black Carbon was 3.8 µg m-3. The trace elements S, K and Fe stood out with higher concentrations. Through Receptor Modeling (Factor Analysis AF and Positive Matrix Factorization PMF), identified the possible sources of PM2,5 in the region. Using the most advanced multivariate model PMF, although it has not shown a clear separation of sources, enabled a more accurate quantification of the identified sources. For this methodology have been identified as sources of PM2,5 vehicle emissions, ressuspension of soil and industries. For both models, the main source identified is related to vehicle emissions approximately 50 % of the mass of fine particulate was explained by vehicular emission (light- and heavy-duty fleet). In the results obtained with PMF, participation of the dust soil was small (2.5 %). The difficulty in identifying the sources can be attributed to lack of measurement of specific tracers of fuels used in the transport sector and the limitations of the analytical system by X-Ray Fluorescence, which has low detection limits for important tracers of industrial and mobile sources as V, Ni, Cr, Se and Cu.

Este trabalho teve como objetivo a identificação e quantificação das fontes do Material Particulado fino (MP2,5) da Região Metropolitana de Porto Alegre (RMPA), em especial, as fontes veiculares. Foram utilizadas amostras coletadas diariamente durante 24 horas, entre junho/2007 a fevereiro/2009 na Universidade Federal de Ciências da Saúde de Porto Alegre, próxima a vias de intenso tráfego. As amostras foram analisadas para determinação da concentração em massa, composição elementar e iônica do MP2,5. A concentração média do particulado fino durante o experimento foi de 13,4 µg m-3 e do Black Carbon foi de 3,8 µg m-3. Os elementos-traço S, K e Fe destacaram-se com concentrações mais elevadas. Através de Modelagem Receptora (Análise de Fatores AF e Fatoração de Matriz Positiva, Positive Matrix Factorization PMF), identificaram-se as possíveis fontes de MP2,5 da região. A utilização do PMF, modelo multivariado mais avançado, embora não tenha mostrado uma clara separação das fontes, possibilitou uma quantificação mais acurada das fontes identificadas. Por essa metodologia foram identificadas como fontes do MP2,5 as emissões veiculares, a ressuspensão do solo e as indústrias. Para ambos os modelos, a principal fonte identificada está relacionada com as emissões veiculares, respondendo por aproximadamente 50 % da massa do particulado fino. Dos resultados obtidos com o PMF, o solo tem uma pequena participação (2,5 %). A dificuldade na identificação das fontes pode ser atribuída a falta de medida de traçadores específicos dos combustíveis utilizados no setor de transporte e as limitações analíticas do sistema de Fluorescência de Raio-X, que possui baixos limites de detecção para importantes traçadores de fontes móveis e industriais como V, Ni, Cr, Se e Cu. / The aim of this work was to identify and quantify the sources of fine particles in the Metropolitan Region of Porto Alegre, specially the vehicular sources. PM2.5 samples collected daily for 24 hours between june/2007 to february/2009 at the Universidade Federal de Ciências da Saúde de Porto Alegre, near heavy traffic routes. The samples were analyzed for determination of mass concentration, elemental and ionic composition. The average concentration of fine particulate matter during the experiment was 13.4 µg m-3 and Black Carbon was 3.8 µg m-3. The trace elements S, K and Fe stood out with higher concentrations. Through Receptor Modeling (Factor Analysis AF and Positive Matrix Factorization PMF), identified the possible sources of PM2,5 in the region. Using the most advanced multivariate model PMF, although it has not shown a clear separation of sources, enabled a more accurate quantification of the identified sources. For this methodology have been identified as sources of PM2,5 vehicle emissions, ressuspension of soil and industries. For both models, the main source identified is related to vehicle emissions approximately 50 % of the mass of fine particulate was explained by vehicular emission (light- and heavy-duty fleet). In the results obtained with PMF, participation of the dust soil was small (2.5 %). The difficulty in identifying the sources can be attributed to lack of measurement of specific tracers of fuels used in the transport sector and the limitations of the analytical system by X-Ray Fluorescence, which has low detection limits for important tracers of industrial and mobile sources as V, Ni, Cr, Se and Cu.

This master’s thesis deals with problems of noise source identification using nearfield acoustical holography (NAH). In the beginning there is the summary of basic terms and values of a sound pressure field, which is unnecessary for understanding of the theme. In the next part the thesis continues with more detailed description of the NAH technology and the historical context of its emergence. Measurement equipment which is used for scanning of sound pressure fields is also introduced. In addition, the kinds of NAH (according the shape of the wave front) are showed and the planar NAH is descripted most closely. Because of the NAH algorithms are implemented in the wave number domain (k-space), there is also a chapter focused to this problem in the thesis. There are briefly descripted some similar methods in next chapter, like statistically optimized NAH, (SONAH) and iterative NAH with recursive filtration. The main product of the thesis is the practical part represented by testing application. That is created in the Matlab environment and is able to calculate and display hologram of the scanned array by the planar NAH method using the “k-space” filter. The application supposes a planar sound source and in other cases the accuracy of the reconstruction is not guaranteed. There are also given some holograms calculated with the application.

Cette étude est consacrée au problème inverse d’estimation de l’intensité et de la position d’une source de polluant. Nous inversons tout d’abord des mesures de concentration à l’intérieur d’une chambre à sable(extension des égouts souterrain) en utilisant la méthode d’identification modale pour estimer l’intensité d’émission du gaz H2S. Une approche originale est ensuite proposée pour estimer la position d’une source en utilisant la notion de transmittance entre deux capteurs. Des outils de régularisation sont utilisés afin d’estimer chaque transmittance, dont le produit de convolution avec la concentration d’un capteur choisi comme référence correspond à la réponse d’un capteur quelconque. Les transmittances estimées à partir des signaux de concentration simulés dans une configuration d’un écoulement tunnel avec source ponctuelle sont ensuite comparées à la sortie d’un modèle analytique 1D de l’équation de transport.L’utilisation d’un algorithme de minimisation non linéaire a permis d’estimer d’abord la vitesse et le coefficient de diffusion de l’écoulement et ensuite la position de la source, sous certaines hypothèses / This numerical study deals with the inverse problem of estimating the intensity and the positionof a pollutant source. The estimation of time-varying emission rates of pollutant sources of H2S in asewer chamber is first implemented through inversion of concentration measurements using the modal identification method. A specific method based on transmittance functions between sensors output isused to estimate the source position. Regularization tools are applied to estimate each transmittance,whose convolution product with the concentration of a reference sensor models the response of any sensor.Transmittances estimated from simulated concentration signals in a tunnel flow with a point source arethen compared to the output of 1D analytical model for the transport equation. A nonlinear minimizationalgorithm is used to estimate the velocity and the diffusion coefficient first and the source position next,under some assumption

L'objectif de ce travail de thèse est la conception d'un système de haut-parleurs transportable, capable de générer un champ sonore prédéfini et focalisé avec un contraste spatial élevé. Ce système doit permettre à terme d'effectuer différents types d'études, par exemple des essais de transparence acoustique ou encore des essais vibratoires en conditions non-anéchoïques. La minimisation du nombre de canaux à piloter ainsi que du nombre des transducteurs est l'un des enjeux principaux du travail. Le choix du nombre de sources et la sélection de leurs positions optimales afin de générer un champ acoustique cible n'a pas de solution triviale. Pour répondre à cette question, la méthode proposée se base sur la décomposition du rayonnement d’une source en série de fonctions orthogonales indépendantes (les"modes de rayonnement"), construits numériquement via une décomposition en valeurs singulières de la matrice d'impédance. En filtrant les termes évanescents, le champ lointain peut être reconstruit à l'aide d'un faible nombre de termes. De plus, la méthode permet d'estimer une distribution de débit efficace pour générer le champ cible. La méthode proposée étant relativement peu étudiée dans la littérature, la première partie de la thèse a été consacrée au problème de la validation expérimentale de la méthode directe et à l'étude des principaux paramètres en influençant le résultat. La problématique du positionnement des sources permettant de synthétiser un champ sonore prédéfini et focalisé est abordée dans la deuxième partie du travail. / The goal of this thesis is the design of a transportable speaker system, able to generate a predefined and focused sound field with a high spatial contrast. This system has eventually to allow carrying out different types of studies, for example acoustic transmission loss tests or vibration tests in non-anechoic conditions. The minimization of the number of driven channels and the number of transducers is one of the main goals of the work. The choice of the number of sources and the selection of their optimal positions in order to generate a target acoustic field has no trivial solution. To answer this question, the proposed method is based on the decomposition of the source radiation into a series of independent orthogonal functions (the "radiation modes"), constructed numerically via a singular value decomposition of the impedance matrix. By filtering the evanescent terms, the far field can be reconstructed using a small number of terms. In addition, the method allows the estimation of an efficient flow distribution to generate the target field. With the proposed method having been scarcely studied in the literature, the first part of the thesis is devoted to the problem of the experimental validation of the direct method and the study of the main parameters that are influencing the result. The problem of sources positioning in order to synthesize a predefined and focused sound field is discussed in the second part of the thesis.