Aerosol Particles
Mostrando 13-24 de 87 artigos, teses e dissertações.
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13. Estudo do mecanismo eletroforético de coleta na filtração de aerossóis.
Previous works have shown that the presence of electrostatic forces in particles significantly affect the performance of a filter, both increasing collection efficiency and reducing pressure drop. Recently, in the Environmental Control research group of the Chemical Engineering Department of UFSCar, Rodrigues (2005) have studied the filtration of electric ch
Publicado em: 2007
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14. Size distribution of atmospheric particulate ionic species at a coastal site in Portugal
A Berner impactor was used to collect size-differentiated aerosol samples from March to August 2003 in the city of Aveiro, on the Portuguese west coast. The samples were analysed for the main water-soluble ion species. The average concentration of sulphate, nitrate, chloride and ammonium was 6.38, 3.09, 1.67 and 1.27 µg m-3, respectively. The results show t
Química Nova. Publicado em: 2007
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15. Measurement of the electrostatic charge in airborne particles: II - particle charge distribution of different aerosols
This work gives sequence to the study on the measurement of the electrostatic charges in aerosols. The particle charge classifier developed for this purpose and presented in the previous paper (Marra and Coury, 2000) has been used here to measure the particle charge distribution of a number of different aerosols. The charges acquired by the particles were na
Brazilian Journal of Chemical Engineering. Publicado em: 2006-03
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16. Studies of air pollution in the municipal district of Sete Lagoas, MG using nuclear techniques / Estudos da poluição do ar do município de Sete Lagoas, MG utilizando técnicas nucleares
Toxic metals, such as Ni, V, Zn, Cu, Cr, Mn and metalloids as As and Se and their compositions are associated mainly with the smaller diameter particulates present in the atmospheric aerosols. This fact is important, principally, when it concerns public health, because this is considered the breathable fraction of particles that can penetrate deeply into the
Publicado em: 2006
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17. "Os fluxos turbulentos de partículas e de compostos orgânicos voláteis, e a distribuição vertical de aerossóis na baixa troposfera da Amazônia" / Measurement of turbulent fluxes of particles and volatile organic compounds, and the aerosol vertical distribution at the Amazonian low troposphere
A Amazônia constitui um ecossistema complexo, no qual a biosfera e a atmosfera estão intrinsecamente relacionadas. Às fontes biogênicas naturais somam-se emissões de queimadas, que alteram significativamente as características da população de aerossóis, e que afetam processos importantes no funcionamento do ecossistema. O presente trabalho integra o
Publicado em: 2006
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18. Comparação de duas metodologias de amostragem atmosférica com ferramenta estatística não paramétrica
In atmospheric aerosol sampling, it is inevitable that the air that carries particles is in motion, as a result of both externally driven wind and the sucking action of the sampler itself. High or low air flow sampling speeds may lead to significant particle size bias. The objective of this work is the validation of measurements enabling the comparison of sp
Química Nova. Publicado em: 2005-03
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19. Effect of biomass-burning emitted aerosols on cloud droplets formation and rainwater chemistry in the Amazon Basin / "Os efeitos de aerossóis emitidos por queimadas na formação de gotas de nuvens e na composição da precipitação na Amazônia"
The main objective of this study was to investigate the relationship between anthropogenic emissions in the Amazon basin and the indirect aerosol effect on climate. A detailed study of physical and chemical properties of natural and biomass burning aerosols was conducted, in order to understand how these completely different aerosols behave as Cloud Condensa
Publicado em: 2005
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20. DESIGN, NUMERICAL SIMULATION AND EXPERIMENTAL EVALUATION OF AN INERTIAL IMPACTOR USED TO COLLECT ATMOSPHERIC AEROSOLS / PROJETO, SIMULAÇÃO NUMÉRICA E TESTE EXPERIMENTAL DE UM IMPACTADOR INERCIAL EM CASCATA PARA AMOSTRAGEM DE AEROSSÓIS ATMOSFÉRICOS
Impactors are simple devices in which a sample flows of air and pollutants flow around an obstacle, called impaction plate. Particles with sufficient inertia will slip across the flow streamlines and impact on the obstacle. Particles with less inertia will follow the airflow away from the impaction surface. Inertial cascade impactors have more than one impac
Publicado em: 2005
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21. Modeling and simulation of multi-component aerosol dynamics
In this paper we consider the modeling of heterogeneous aerosol coagulation where the heterogeneous aerosol particles (called droplets) contain smaller particles (enclosures). Droplets and enclosures coagulate with different collision kernels. We discuss macroscopic modeling and simulation of these processes using both deterministic and Monte-Carlo methods.
Computational & Applied Mathematics. Publicado em: 2004-12
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22. AEROSOL CHARACTERIZATION IN A REGION WITH HIGH CONCENTRATION OF MINERAL SANDS. / CARACTERIZAÇÃO DE AEROSSÓIS EM UMA REGIÃO RICA EM AREIAS MONAZÍTICAS.
The main deposit of mineral sands in Brasil occur from the Rio Grande do Norte State to Rio de Janeiro State. The main commercial deposit is located in Buena, a village at São Francisco de Itabapoana, Rio de Janeiro State. In buena there is a plant that process minerals sands to obtain ilmenite, zirconite, rutile and monazite concentrates. This plant belong
Publicado em: 2003
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23. Origem e implicações dos ácidos carboxílicos na atmosfera
A general overview about the ambient levels of low molecular weight carboxylic acids and their possible emission sources, as well as the implication of them in the atmosphere is presented. Carboxylic acids are considered to be one of the dominant classes of organic compounds found in the atmosphere in a variety of phases, such as in rainwater, snow and ice,
Química Nova. Publicado em: 2001-02
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24. Aerosol Source Apportionment study in São Paulo city / A Determinação Quantitativa de Fontes de Material Particulado na Atmosfera da Cidade de São Paulo
A região metropolitana de São Paulo apresenta problemas crônicos de poluição atmosférica. A poluição atmosférica em centros urbanos é comprovadamente prejudicial à saúde da população exposta, o que gera uma preocupação mundial acerca deste tema. Com o intuito de identificar e quantificar a contribuição de fontes e a importância das emissõ
Publicado em: 1999