Tesis sobre el tema "Aerosols"
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Kwok, Philip Chi Lip. "Electrostatics of aerosols for inhalation". Thesis, The University of Sydney, 2007. http://hdl.handle.net/2123/1934.
Texto completoKwok, Philip Chi Lip. "Electrostatics of aerosols for inhalation". Faculty of Pharmacy, 2007. http://hdl.handle.net/2123/1934.
Texto completoElectrostatics of aerosols for inhalation is a relatively new research area. Charge properties of these particles are largely unknown but electrostatic forces have been proposed to potentially influence lung deposition. Investigation on the relationship between formulation and aerosol charging is required to understand the fundamental mechanisms. A modified electrical low pressure impactor was employed to measure the particles generated from metered dose inhalers and dry powder inhalers. This equipment provides detailed size and charge information of the aerosols. The particles were sized by impaction onto thirteen stages. The net charges in twelve of the size fractions were detected and recorded by sensitive electrometers. The drug deposits were quantified by chemical assay. The aerosol charge profiles of commercial metered dose inhalers were product-dependent, which was due to differences in the drug, formulation, and valve stem material. The calculated number of elementary charges per drug particle of size ≤ 6.06 μm ranged from zero to several ten thousands. The high charge levels on particles may have a potential effect on the deposition of the aerosol particles in the lung when inhaled. New plastic spacers marketed for use with metered dose inhalers were found to possess high surface charges on the internal walls, which was successfully removed by detergent-coating. Detergent-coated spacer had higher drug output than the new ones due to the reduced electrostatic particle deposition inside the spacer. Particles delivered from spacers carried lower inherent charges than those directly from metered dose inhalers. Those with higher charges might be susceptible to electrostatic forces inside the spacers and were thus retained. The electrostatic low pressure impactor was further modified to disperse two commercial Tubuhaler® products at 60 L/min. The DPIs showed drug-specific responses to particle charging at different RHs. The difference in hygroscopicity of the drugs may play a major role. A dual mechanistic charging model was proposed to explain the charging behaviours. The charge levels on drug particles delivered from these inhalers were sufficiently high to potentially affect deposition in the airways when inhaled. Drug-free metered dose inhalers containing HFA-134a and 227 produced highly variable charge profiles but on average the puffs were negatively charged, which was thought to be due to the electronegative fluorine atoms in the HFA molecules. The charges of both HFAs shifted towards neutrality or positive polarity with increasing water content. The spiked water might have increased the electrical conductivity and/or decreased the electronegativity of the bulk propellant solution. The number of elementary charges per droplet decreased with decreasing droplet size. This trend was probably due to the redistribution of charges amongst small droplets following electrostatic fission of a bigger droplet when the Raleigh limit was reached.
Gallavardin, Stéphane. "Analysis concepts of aerosols by on-line aerosol mass spectrometry". [S.l.] : [s.n.], 2006. http://mediatum2.ub.tum.de/doc/603768/document.pdf.
Texto completoAlfarra, Mohammedrami. "Insights into atmospheric organic aerosols using an aerosol mass spectrometer". Thesis, University of Manchester, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.577471.
Texto completoMa, Yilin. "Developments and improvements to the particle-into-liquid-sampler (PILS) and its applications to Asian outflow studies". Diss., Available online, Georgia Institute of Technology, 2004:, 2004. http://etd.gatech.edu/theses/available/etd-06072004-131244/unrestricted/ma%5Fyilin%5F200405%5Fphd.pdf.
Texto completoLi, Xihao. "Characterization of Perphenazine and Scopolamine Aerosols Generated Using the Capillary Aerosol Generator". VCU Scholars Compass, 2006. http://scholarscompass.vcu.edu/etd/901.
Texto completoWurl, Daniela. "Optimal Estimation Retrieval of Aerosol Microphysical Properties in the Lower Stratosphere from SAGE II Satellite Observations". Thesis, University of Canterbury. Physics and Astronomy, 2007. http://hdl.handle.net/10092/1533.
Texto completoWan, Chun Hong. "Sugars and polyol compounds in ambient aerosols and cooking fume aerosols /". View abstract or full-text, 2006. http://library.ust.hk/cgi/db/thesis.pl?CHEM%202006%20WAN.
Texto completoSvane, Maria. "Aerosol chemistry on the single particle level : an experimental study /". Göteborg : Göteborg University, Department of Chemistry, Atmospheric Science, 2005. http://www.loc.gov/catdir/toc/fy0801/2006411316.html.
Texto completoPosselt, Julia Rebekka. "Influence of giant sea salt aerosols on global precipitation and aerosol indirect effect /". Zürich : ETH, 2007. http://e-collection.ethbib.ethz.ch/show?type=diss&nr=17467.
Texto completoDreyfus, Matthew A. "Laboratory and field measurements of organic aerosols with the photoionization aerosol mass spectrometer". Access to citation, abstract and download form provided by ProQuest Information and Learning Company; downloadable PDF file, 166 p, 2008. http://proquest.umi.com/pqdweb?did=1654492141&sid=6&Fmt=2&clientId=8331&RQT=309&VName=PQD.
Texto completoAdikesavalu, Ravichandran. "Preliminary modeling of in-duct desulfurization using condensation aerosols". Ohio : Ohio University, 1997. http://www.ohiolink.edu/etd/view.cgi?ohiou1177616476.
Texto completoMeyer, Nicholas Karl. "Water uptake of aerosols with a focus on seeded aerosols and instrumentation techniques". Thesis, Queensland University of Technology, 2008. https://eprints.qut.edu.au/26361/1/Nicholas_Meyer_Thesis.pdf.
Texto completoMeyer, Nicholas Karl. "Water uptake of aerosols with a focus on seeded aerosols and instrumentation techniques". Queensland University of Technology, 2008. http://eprints.qut.edu.au/26361/.
Texto completoZhang, Xiaolu. "The sources, formation and properties of soluble organic aerosols: results from ambient measurements in the southeastern united states and the los angeles basin". Diss., Georgia Institute of Technology, 2012. http://hdl.handle.net/1853/44894.
Texto completoYeung, Ming Chee. "Study of phase transition and hygroscopic properties of pure and multi-component atmospheric particles by optical microscopic imaging and micro-raman spectroscopy /". View abstract or full-text, 2009. http://library.ust.hk/cgi/db/thesis.pl?EVNG%202009%20YEUNG.
Texto completoSummers, Michael David. "Optical micromanipulation of aerosols". Thesis, St Andrews, 2009. http://hdl.handle.net/10023/779.
Texto completoLavelle, S. P. "Characterisation of bioactive aerosols". Thesis, London South Bank University, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.618633.
Texto completoLovrić, Josip. "Molecular modeling of aerosols". Thesis, Lille 1, 2017. http://www.theses.fr/2017LIL10080/document.
Texto completoIn this thesis numerical methods are used to study the properties, described at the molecular level, of organic aerosols, especially marine aerosols, and their interaction with species in the atmosphere. The organisation of the organic matter in these aerosols plays a key role for their optical, chemical properties, and their ability to act as a cloud condensation nuclei.The first part reviews atmospheric context and the methods (classical molecular dynamics and hybrid quantum/classical approaches) used in this thesis. Then applications to three cases are detailed.Firstly, the organization, more particularly the orientation, of palmitic acid molecules adsorbed on a salt (NaCl) surface as a function of the fatty acid coverage and temperature has been studied using classical molecular dynamics (Gromacs package). The impact of the humidity on the structuration of this organic coating has been described in details, showing the existence of structured fatty acid island-like monolayers on NaCl surface.In a second study, the reactivity of NO2 with these heterogeneous marine aerosols has been investigated by a hybrid quantum/classical method (CP2K package), with taking into account the effect of the humidity.The last study is a classical molecular dynamics of n-butanol crystal, water accommodation at these surfaces and simulation of water jet collision with n-butanol surface. These simulations, complementary to experiments, were performed to better understand the fundamental role of the water-organic matter interaction on the properties of the aerosols and clouds
Sukhapan, Jariya. "Surfactants in atmospheric aerosols". Thesis, University of East Anglia, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.251504.
Texto completoTripathi, Sachchida Nand. "Removal of charged aerosols". Thesis, University of Reading, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.325074.
Texto completoDavidson, Nicholas Mark. "Atmospheric processing of aerosols". Thesis, University of Birmingham, 2018. http://etheses.bham.ac.uk//id/eprint/8298/.
Texto completoROVELLI, GRAZIA. "Characterizing the hygroscopic properties of aerosols: from binary aqueous systems to atmospheric aerosols". Doctoral thesis, Università degli Studi di Milano-Bicocca, 2016. http://hdl.handle.net/10281/104639.
Texto completoSodeman, David Alan. "Characterization of ambient, automobile, and diesel aerosols utilizing aerosol time of flight mass spectrometry /". Diss., Connect to a 24 p. preview or request complete full text in PDF format. Access restricted to UC campuses, 2004. http://wwwlib.umi.com/cr/ucsd/fullcit?p3144344.
Texto completoMills, Jessica Breyan. "Evaluation of the DiSCmini personal aerosol monitor for submicrometer sodium chloride and metal aerosols". Thesis, University of Iowa, 2013. https://ir.uiowa.edu/etd/2584.
Texto completoZuluaga-Arias, Manuel D. "Spatio-temporal variability of aerosols in the tropics relationship with atmospheric and oceanic environments". Diss., Georgia Institute of Technology, 2011. http://hdl.handle.net/1853/41202.
Texto completoCapes, Gerard. "Aging of biomass burning aerosols and formation of secondary organic aerosols over West Africa". Thesis, University of Manchester, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.498784.
Texto completoLaucks, Mary Lisa. "Quantifying the uncertainties in measurements of aerosol optical properties relevant to the direct shortwave forcing of climate /". Thesis, Connect to this title online; UW restricted, 1996. http://hdl.handle.net/1773/10314.
Texto completoPierce, Flint G. "Aggregation in colloids and aerosols". Diss., Manhattan, Kan. : Kansas State University, 2007. http://hdl.handle.net/2097/348.
Texto completoKnox, Christopher James Henry. "The photochemistry of liquid aerosols". Thesis, University of Canterbury. Chemistry, 2002. http://hdl.handle.net/10092/6076.
Texto completoSimo, John A. (John Alfred). "Turbulent transport of inertial aerosols". Thesis, Massachusetts Institute of Technology, 1991. http://hdl.handle.net/1721.1/38716.
Texto completoTranchant, Benoît. "Simulations numeriques des aerosols marins". Nantes, 1997. http://www.theses.fr/1997NANT2009.
Texto completoWarren, Dale Ross Seinfeld John H. "Nucleation and growth of aerosols /". Diss., Pasadena, Calif. : California Institute of Technology, 1986. http://resolver.caltech.edu/CaltechETD:etd-03212008-085926.
Texto completoWexler, Anthony S. Seinfeld John H. Seinfeld John H. "Inorganic components of atmospheric aerosols /". Diss., Pasadena, Calif. : California Institute of Technology, 1991. http://resolver.caltech.edu/CaltechETD:etd-07172007-083859.
Texto completoSilva, Leticia Caetano da [UNESP]. "Propriedades químicas e físicas do material particulado atmosférico e seus efeitos no crescimento de partículas". Universidade Estadual Paulista (UNESP), 2013. http://hdl.handle.net/11449/108489.
Texto completoAerossóis são espécies sólidas ou líquidas suspendidas e/ou transportadas pelo ar, com diâmetro médio da ordem nano ou micrométrica. Os aerossóis podem modificar a atmosfera do planeta, afetar a saúde dos seres vivos, alterar a visibilidade e até mesmo o clima e a disponibilidade de água potável. Estes fatos justificam a necessidade de melhorar o conhecimento sobre suas características físicas e químicas. As rápidas mudanças na quantidade e composição dos aerossóis na atmosfera são resultados de atividades antrópicas que estão se intensificando como resultado de expansão econômica. Fora dos centros urbanos, as atividades relacionadas ao agronegócio são responsáveis por grande parte da emissão dos aerossóis. A região do centro-oeste paulista destaca-se pela grande área destinada à plantação de cana-de-açúcar. Parte significativa ainda utiliza a queima da palha para facilitação da colheita manual. O presente estudo descreve a caracterização química e física do material particulado atmosférico no interior do estado de São Paulo no período entre Maio de 2010 a Fevereiro de 2012. O maior número de amostras foi coletada na região central do estado, no município de Araraquara, dentro do Campus da Unesp, localizado a sudoeste da área urbana. Outras amostras foram coletadas a sudoeste do Estado, no município de Ourinhos, no Campus da UNESP, localizado a 5 km do centro urbano Nesta campanha participaram diferentes grupos de pesquisa. Para a coleta do aerossol utilizou-se filtros de Teflon e vazão de amostragem de ≈9 L min-1. Este procedimento possibilitou a coleta do material particulado suspenso total. Nas amostras coletadas foram determinadas as espécies iônicas solúveis em água por cromatografia de íons (NH4+, Na+, K+, Mg2+, Ca2+, Cl-, NO3-, SO42-, PO43-, C2O42-. O equipamento utilizado não permitiu a separação das espécies orgânicas acetato e formiato, apresentadas aqui como a somatórias...
Aerosols are suspended solid or liquid species and / or airborne, with an average diameter of the nano or micron order. Aerosols can modify the atmosphere of the planet, affect the health of living beings, change the visibility and even the weather and availability of drinking water. These facts justify the need to improve the knowledge about their physical and chemical characteristics. Rapid changes in the amount and composition of aerosols in the atmosphere are the result of human activities, which are increasing as a result of economic expansion. Outside urban centers , the activities related to agribusiness are responsible for much of the emission of aerosols. The region of the center - west of São Paulo is distinguished by large area for sugar cane crop. Significant part still uses the of straw burning to facilitate the manual harvesting. The present study describes the chemical and physical characterization of atmospheric particulate matter in the state of São Paulo in the period from May 2010 to February 2012. The largest number of samples was collected in the central region of the state, the city of Araraquara, UNESP at the Campus, located southwest of the urban area. Other samples were collected southwest of the state , in the Ourinhos city, at the campus of UNESP, located 5 km from the city center. Together the campaign participated different research groups. To collect the aerosol was used Teflon filters and flow sampling ≈ 9 L min-1. This procedure allowed the collection of total suspended particulate matter. In the collected samples were determined water soluble ionic species by ion chromatography (NH4+, Na+, K+ , Mg2+ , Ca2+ , Cl- , NO3- , SO42- , PO43- , C2O42-). Equipment used did not enabled the separation of organic species acetate and formate, shown here as the summation of these organic anions ( H3CCOO- + HCOO-). In parallel directly measurements were performed to get the number concentration of particles...
Souza, Michele de Lima. "Estudo da distribuição de tamanhos e composição iônica de aerossóis e seus efeitos na capacidade de nuclear gotas de nuvens /". Araraquara, 2016. http://hdl.handle.net/11449/136462.
Texto completoBanca: Paulo Clairmont Feitosa de Lima Gomes
Banca: Theotonio Mendes Pauliquevis Júnior
Banca: Adalgiza Fornaro
Banca: Bernardino Ribeiro de Figueiredo
Resumo: Este trabalho buscou evidências para reconhecer mudanças sazonais nas emissões e consequentes mudanças na composição de aerossóis presentes em uma região subtropical a fetada pela queima de biomassa agrícola. Aquisições de dados de distribuição de tamanho e amostragem de aerossol foram feitas próximas ao centro geográfico do estado de São Paulo, no município de Araraquara. A composição iônica das espécies solúveis foram determinadas pela técnica da cromatografia de íons. Diferentes concentrações numéricas da fração mais fina de aerossóis mostraram ser dependentes de condições atmosféricas e, portanto, mostram variações sazonais na formação e crescimento de partículas. A o corrência preferencial de processos de nucleação homogênea, foram mais pronunciados durante os meses mais chuvosos de verão. Já os processos de nucleação heterogênea, foram favorecidos durante o inverno, quando ocorrem emissões mais intensas da queima de b iomassa. A moda de nucleação e a moda de Aitken foram favorecidas no período úmido (verão) e períodos de seca (inverno queima de biomassa), respectivamente. A moda de acumulação mostrou picos no verão e no inverno, o que pode ser explicado pelo crescimento das partículas por efeitos de higroscopicidade e reações heterogêneas concomitantes. Também buscou - se quantificar o possível efeito da presença de aerossóis localizados próximos ao solo nas propriedades das nuvens. Para buscar evidências de interção aeros sol - nuvem foram coletados dados a respeito do raio efetivo da gota e da profundidade óptica da nuvem. Estes dados foram obtidos pelo tratamento das medidas realizadas por satélites que orbitam sobre a região de estudo. Os resultados obtidos ao longo de ma is de um ano indicaram que as fontes de emissões regionais contribuem para a emissão de aerossóis primários ou formação de aerossóis secundários, que...
Abstract: This study aimed to recognize seasonal changes in emissions and consequent changes in the composition of aerosols present in a subtropical region affected by the agricultural biomass burning. Data acquisition relat ed to the size distribution and aerosol samples were taken near the geog raphical center of the São Paulo state, in the city of Araraquara. The ionic composition of the soluble species were determined by the ion - chromatography technique. Different numerical concentrations of the finer fraction of aerosols showed to be dependent of the atmospheric conditions and, thus, show ed seasonal variations in particle formation and growth. The preferential occurrence of homogeneous nucleation processes were more pronou nced during the rainy summer months. But, the heterogeneous nucleation processes were favored during the winter, when there are more intense emissions from biomass burning. The nucleation and Aitken modes were favored in the wet season (summer) and dry per iods (winter biomass burning), respectively. Accumulation mode showed peaks in summer and winter, which can be explained by the growth of the particles by the effects of hygroscopicity and concur rent heterogeneous reactions. This work also sought to quanti fy the possible effect of the presence of aerosols located close to the ground in the clouds properties.To seek evidence of aerosol - cloud interaction, data were collected about the effective radius of the drop and the optical depth of the cloud. These data were obtained from satellites that orbiting over the region of study. The results of the studies over more than one year indicated that the sources of regional emissions contribute to the emission of primary aerosols or formation of secondary aerosols, that can influence the cloud formation process. These facts suggest that the seasonal human activities in the region can alter the composition of the aerosol and this, in t...
Doutor
Silva, Leticia Caetano da. "Propriedades químicas e físicas do material particulado atmosférico e seus efeitos no crescimento de partículas /". Araraquara, 2013. http://hdl.handle.net/11449/108489.
Texto completoBanca: Mercedes de Moraes
Banca: Janaína Braga do Carmo
Banca: Lilian Rothschild Franco de Carvalho
Banca: Gisele Olimpio da Rocha
Resumo: Aerossóis são espécies sólidas ou líquidas suspendidas e/ou transportadas pelo ar, com diâmetro médio da ordem nano ou micrométrica. Os aerossóis podem modificar a atmosfera do planeta, afetar a saúde dos seres vivos, alterar a visibilidade e até mesmo o clima e a disponibilidade de água potável. Estes fatos justificam a necessidade de melhorar o conhecimento sobre suas características físicas e químicas. As rápidas mudanças na quantidade e composição dos aerossóis na atmosfera são resultados de atividades antrópicas que estão se intensificando como resultado de expansão econômica. Fora dos centros urbanos, as atividades relacionadas ao agronegócio são responsáveis por grande parte da emissão dos aerossóis. A região do centro-oeste paulista destaca-se pela grande área destinada à plantação de cana-de-açúcar. Parte significativa ainda utiliza a queima da palha para facilitação da colheita manual. O presente estudo descreve a caracterização química e física do material particulado atmosférico no interior do estado de São Paulo no período entre Maio de 2010 a Fevereiro de 2012. O maior número de amostras foi coletada na região central do estado, no município de Araraquara, dentro do Campus da Unesp, localizado a sudoeste da área urbana. Outras amostras foram coletadas a sudoeste do Estado, no município de Ourinhos, no Campus da UNESP, localizado a 5 km do centro urbano Nesta campanha participaram diferentes grupos de pesquisa. Para a coleta do aerossol utilizou-se filtros de Teflon e vazão de amostragem de ≈9 L min-1. Este procedimento possibilitou a coleta do material particulado suspenso total. Nas amostras coletadas foram determinadas as espécies iônicas solúveis em água por cromatografia de íons (NH4+, Na+, K+, Mg2+, Ca2+, Cl-, NO3-, SO42-, PO43-, C2O42-. O equipamento utilizado não permitiu a separação das espécies orgânicas acetato e formiato, apresentadas aqui como a somatórias...
Abstract: Aerosols are suspended solid or liquid species and / or airborne, with an average diameter of the nano or micron order. Aerosols can modify the atmosphere of the planet, affect the health of living beings, change the visibility and even the weather and availability of drinking water. These facts justify the need to improve the knowledge about their physical and chemical characteristics. Rapid changes in the amount and composition of aerosols in the atmosphere are the result of human activities, which are increasing as a result of economic expansion. Outside urban centers , the activities related to agribusiness are responsible for much of the emission of aerosols. The region of the center - west of São Paulo is distinguished by large area for sugar cane crop. Significant part still uses the of straw burning to facilitate the manual harvesting. The present study describes the chemical and physical characterization of atmospheric particulate matter in the state of São Paulo in the period from May 2010 to February 2012. The largest number of samples was collected in the central region of the state, the city of Araraquara, UNESP at the Campus, located southwest of the urban area. Other samples were collected southwest of the state , in the Ourinhos city, at the campus of UNESP, located 5 km from the city center. Together the campaign participated different research groups. To collect the aerosol was used Teflon filters and flow sampling ≈ 9 L min-1. This procedure allowed the collection of total suspended particulate matter. In the collected samples were determined water soluble ionic species by ion chromatography (NH4+, Na+, K+ , Mg2+ , Ca2+ , Cl- , NO3- , SO42- , PO43- , C2O42-). Equipment used did not enabled the separation of organic species acetate and formate, shown here as the summation of these organic anions ( H3CCOO- + HCOO-). In parallel directly measurements were performed to get the number concentration of particles...
Doutor
Sullivan, Amy Patricia. "The Ambient Organic Aerosol Soluble in Water: Measurements, Chemical Characterization, and an Investigation of Sources". Diss., Available online, Georgia Institute of Technology, 2006, 2006. http://etd.gatech.edu/theses/available/etd-05022006-111928/.
Texto completoRodney J. Weber, Committee Chair ; Michael H. Bergin, Committee Member ; Committee Member ; Martial Taillefert, Committee Member ; Paul H. Wine, Committee Member.
Hsieh, Wei-Chun. "Representing droplet size distribution and cloud processes in aerosol-cloud-climate interaction studies". Diss., Atlanta, Ga. : Georgia Institute of Technology, 2009. http://hdl.handle.net/1853/29619.
Texto completoCommittee Chair: Athanasios Nenes; Committee Member: Andrew G. Stack; Committee Member: Irina N. Sokolik; Committee Member: Judith A. Curry; Committee Member: Mike Bergin; Committee Member: Rodney J. Weber. Part of the SMARTech Electronic Thesis and Dissertation Collection.
Steele, Henry Donnan 1974. "Investigations of cloud altering effects of atmospheric aerosols using a new mixed Eulerian-Lagrangian aerosol model". Thesis, Massachusetts Institute of Technology, 2004. http://hdl.handle.net/1721.1/58445.
Texto completoIncludes bibliographical references (p. 275-315).
Industry, urban development, and other anthropogenic influences have substantially altered the composition and size-distribution of atmospheric aerosol particles over the last century. This, in turn, has altered cloud albedo, lifetime, and patterns which together are thought to exert a negative radiative forcing on the climate; these are the indirect effects of atmospheric aerosols. The specifics of the process by which aerosol particles seed cloud particles are complex and highly uncertain. The goal of this thesis is to refine understanding of the role of various aerosol types in determining cloud properties. We approach this goal by constructing a new highly detailed aerosol-cloud process model that is designed to simulate condensation upon complex aerosol populations. We use this model to investigate the microphysics of aerosol-cloud interactions, specifically considering the role of cloud dynamics and of the ubiquitous mixed soot / sulfate aerosols. We describe the Mixed Eulerian-Lagrangian Aerosol Model (MELAM). This new computer model of aerosol microphysics is specifically tailored to simulate condensation and activation as accurately as possible. It specifically calculates aerosol thermodynamics, condensation, coagulation, gas and aqueous phase chemistry, and dissolution. The model is able to consider inorganic aerosols and aerosols with both inorganics and insoluble cores; the specific chemical system to be considered is specified by the user in text input files. Aerosol particles may be represented using "sectional distributions" or using a "representative sample" distribution which tracks individual particles.
(cont.) We also develop a constant updraft speed, adiabatic parcel model and a variable updraft speed, episodically entraining parcel model to provide boundary conditions to MELAM and allow simulations of aerosol activation in cloud updrafts. Using MELAM and the parcel models, we demonstrate that aerosol activation depends on the composition and size distribution of the sub-cloud aerosol population, on the updraft speed through a parcel's lifting condensation level, on the vertical profile of the updraft speed, and on entrainment. We use a convective parameterization that was developed for use in global or regional models to drive the episodically entraining, variable updraft speed parcel model. Ultimately, reducing the uncertainty of the global impact of the indirect effects of aerosols will depend on successfully linking cloud parameterizations to models of aerosol activation; our work represents a step in that direction. We also consider the activation of mixed soot / sulfate particles in cloud updrafts. We constrain for the first time a model of condensation onto these mixed particles that incorporates the contact angle of the soot / solution interface and the size of the soot core. We find that as soot ages and its contact angle with water decreases, mixed soot / sulfate aerosols activate more readily than the equivalent sulfate aerosols that do not have soot inclusions. We use data from the Aerosol Characterization Experiments (ACE) 1 and 2, and from the Indian Ocean Experiment (INDOEX) to define representative aerosol distributions for clean, polluted, and very polluted marine environments. Using these distributions, we argue that the trace levels of soot observed in clean marine environments do not substantially impact aerosol activation, while the presence of soot significantly increases the number of aerosol that activate in polluted areas.
by Henry Donnan Steele.
Ph.D.
Aiken, Allison Carol. "Quantitative chemical analysis of ambient organic aerosols using high-resolution time-of-flight aerosol mass spectrometry". Connect to online resource, 2008. http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:3337069.
Texto completoPeltier, Richard Edward. "Ambient Submicron Particles In North America: Their Sources, Fate, and Impact". Diss., Atlanta, Ga. : Georgia Institute of Technology, 2007. http://hdl.handle.net/1853/19750.
Texto completoCommittee Chair: Weber, Rodney J.; Committee Member: Bergin, Michael H.; Committee Member: Huey, L Gregory; Committee Member: Ingall, Ellery D.; Committee Member: Nenes, Athanasios.
Vinchurkar, Samir C. "Numerical Analysis of Respiratory Aerosol Deposition: Effects of Exhalation, Airway Constriction and Electrostatic Charge". VCU Scholars Compass, 2008. http://hdl.handle.net/10156/2014.
Texto completoPrepared for: Dept. of Mechanical Engineering. Includes bibliographical references (leaves 212-233). Also available online via the Internet.
Indoitu, Rodica. "Chemical properties of aerosols over Israel /". [Sede Boker] : Albert Katz International School for Desert Studies, 2006. http://aranne5.lib.ad.bgu.ac.il/others/IndoituRodica.pdf.
Texto completoEngvall, Ann-Christine. "Properties and origin of arctic aerosols /". Stockholm : Department of Meteorology, Stockholm university, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-7524.
Texto completoMegner, Linda. "Meteoric Aerosols in the Middle Atmosphere". Doctoral thesis, Stockholm : Department of Meteorology, Stockholm university, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-7734.
Texto completoRowland, Glenn Anthony. "The photochemistry of sulfuric acid aerosols". Thesis, University of Canterbury. Chemistry, 2001. http://hdl.handle.net/10092/5949.
Texto completoHamilton, Douglas Stephen. "Effects of natural aerosols on climate". Thesis, University of Leeds, 2016. http://etheses.whiterose.ac.uk/16272/.
Texto completoChatain, Audrey. "Aerosols-plasma interaction in Titan’s ionosphere". Thesis, université Paris-Saclay, 2020. http://www.theses.fr/2020UPASV022.
Texto completoThe climatic system of Saturn’s moon Titan is governed by the intense production of organic aerosols in its upper atmosphere. This phenomenon also certainly happened on Earth at the beginning of life. These two points strongly motivate research on the formation and evolution processes of the aerosols in the atmosphere of Titan. The aerosols form and stay several weeks in the ionosphere, between ~900-1200 km of altitude. This atmospheric layer is ionized by UV solar rays and energetic particles coming from Saturn’s magnetosphere, forming a plasma with very reactive species: radicals, excited species, ions and electrons. In such an environment, the main question I tackle is how the organic aerosols interact with the plasma species.The phenomenon is simulated in the laboratory with a plasma setup developed on purpose: analogues of Titan aerosols are exposed to a N2-H2 plasma discharge. Both an evolution of the solid and the gas phase are observed. H and N atoms chemically interact with the aerosols. Then, hydrogen cyanide (HCN) and other organic molecules are ejected in the gas phase by ion sputtering. These results highlight an important contribution of heterogeneous processes in Titan’s upper atmosphere.My re-analysis of the Cassini Langmuir probe data revealed the presence of an unexpected electron population in the ionosphere, below 1200 km and on the day-side, where heavy ions are also detected. These electrons could be emitted by the aerosols, after collision with a photon, and/or heating by the active ion chemistry
Riggs, Charles Alan. "Adsorption isotherms of cesium reactor aerosols /". free to MU campus, to others for purchase, 2002. http://wwwlib.umi.com/cr/mo/fullcit?p3074439.
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