Tesi sul tema "Aerosol origins"
Cita una fonte nei formati APA, MLA, Chicago, Harvard e in molti altri stili
Vedi i top-25 saggi (tesi di laurea o di dottorato) per l'attività di ricerca sul tema "Aerosol origins".
Accanto a ogni fonte nell'elenco di riferimenti c'è un pulsante "Aggiungi alla bibliografia". Premilo e genereremo automaticamente la citazione bibliografica dell'opera scelta nello stile citazionale di cui hai bisogno: APA, MLA, Harvard, Chicago, Vancouver ecc.
Puoi anche scaricare il testo completo della pubblicazione scientifica nel formato .pdf e leggere online l'abstract (il sommario) dell'opera se è presente nei metadati.
Vedi le tesi di molte aree scientifiche e compila una bibliografia corretta.
Taubman, Brett F. "Airborne characterization of regional aerosol origins and optical properties". College Park, Md. : University of Maryland, 2004. http://hdl.handle.net/1903/1893.
Thesis research directed by: Chemistry. Title from t.p. of PDF. Includes bibliographical references. Published by UMI Dissertation Services, Ann Arbor, Mich. Also available in paper.
Velazquez, Garcia Alejandra. "Chemical and optical properties of particulate pollution in the Lille area, Northern France based on ATOLL observations". Electronic Thesis or Diss., Ecole nationale supérieure Mines-Télécom Lille Douai, 2023. http://www.theses.fr/2023MTLD0001.
The link between fine aerosol optical properties and their chemical composition is not yet well understood, and was investigated using long-term in situ observations performed at the “ATmospheric Observations in liLLe” platform from 2016 to 2020 using a combination of aerosol mass spectrometer, aethalometer, and nephelometer. Highly absorbing aerosols and a marked seasonality of the mass contribution of ammonium nitrate (AN) in spring were observed. We evidence that AN (35%) and carbonaceous aerosols (51%) are predominant regarding light extinction at 525 nm. Besides, a novel approach combining these in situ measurements to backtrajectories and emission inventories identifies a Brown Carbon (BrC) decrease within 24 hours after emission even during wintertime, pointing at a likely systematic underestimation of the contribution of residential heating (identified by the presence of BrC) to the aerosol absorption in the region
Engvall, 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.
Leung, Fok-Yan Thomas Hoffmann Michael R. "Elucidation of the origins of stratospheric sulfate aerosols by isotopic methods /". Diss., Pasadena, Calif. : California Institute of Technology, 2003. http://resolver.caltech.edu/CaltechETD:etd-05292003-144531.
Garbaras, Andrius. "Study of aerosol particle origin and dispersion by isotope ratio mass spectrometry". Doctoral thesis, Lithuanian Academic Libraries Network (LABT), 2011. http://vddb.laba.lt/obj/LT-eLABa-0001:E.02~2011~D_20110705_095446-72095.
Žemės atmosfera yra svarbiausia klimato sferos dalis ir jautriausias antropogeninei taršai aplinkos sandas. Atmosferoje vykstantys procesai pakeičia ekosistemose per šimtmečius nusistovėjusius procesus – stebime įvairias globalinės klimato kaitos sukeltas pasekmes. Mokslinė šio darbo idėja nukreipta į įvairiapusį atmosferos aerozolio dalelių savybių ir prigimties tyrimą bei tyrimo metodų plėtrą, pasiremiant naujausiomis aplinkotyros mokslo žiniomis, akcentuojant pastarojo dešimtmečio masių spektrometrijos pasiekimus. Šio darbo tikslas yra organinių medžiagų ir juodosios anglies atmosferos aerozolio dalelėse kilmės, aerozolio sudėties ir formavimosi tyrimai bei naujų tyrimo metodų plėtra. Darbe eksperimentiškai įrodyta, kad anglies izotopų santykis antropogeninės kilmės aerozolio dalelėse atitinka deginamo kuro izotopų santykį ir šis parametras tinka, identifikuojant aerozolio dalelių šaltinį. Šis izotopų santykis, kaip metodinė priemonė, buvo panaudotas tiriant įvairios prigimties aerozolio sudėtį, savybes ir kilmę. Tiriant aerozolio daleles tolimojoje oro pernašoje stebėjome elementinės anglies δ13C verčių kaitą akumuliacinėje modoje nuo -22,9 ‰ iki -26,3 ‰, organinės anglies δ13C = -28 ‰. Iš δ13C verčių nustatyta, jog elementinės anglies pirmtakai aerozolio dalelėse buvo degimo produktai, organinės anglies šaltinis – lakūs organiniai junginiai iš augalų. Vietinės kilmės dalelių, didesnių už 1 μm, stebėta karbonatinė komponentė. Apjungus masių ir izotopų santykių masių... [toliau žr. visą tekstą]
Garbarienė, Inga. "Origin, chemical composition and formation of submicron aerosol particles in the atmosphere". Doctoral thesis, Lithuanian Academic Libraries Network (LABT), 2014. http://vddb.library.lt/obj/LT-eLABa-0001:E.02~2014~D_20140520_134625-72680.
Disertacija skirta smulkiosios aerozolio dalelių frakcijos šaltinių, fizikinių ir cheminių savybių įvertinimui kompleksiškai apjungiant įvairius tyrimo metodus. Darbe susieti elementinės ir organinės anglies koncentracijų pokyčiai su tolimąja oro masių pernaša, įvertinta regiono bei vietinių šaltinių įtaka bendrai aerozolio dalelių taršai. Aprašyti anglies turinčių aerozolio dalelių pasiskirstymai pagal dydį foninėse vietovėse ir miesto aplinkoje. Naudojant aerozolio masių spektrometrą Preilos atmosferos užterštumo tyrimų stotyje buvo identifikuotas biogeninis organinių medžiagų šaltinis, kuris vidutiniškai sudaro 15 % nuo organinių medžiagų masės, tačiau Šiaurės Atlanto oro masėje biogeninių medžiagų indėlis siekia net 50 %. Atlikus kompleksinę aerozolio ir stabiliųjų anglies izotopų masių spektrometrinę analizę buvo nustatyta, kad pirminis anglies turinčio aerozolio dalelių šaltinis mieste yra autotransportas, o Rūgšteliškio foninėje vietovėje – biomasės deginimas. Taip pat buvo nustatyta, kad Vilniuje dominavo antropogeninės antrinės organinės medžiagos (76 %), o Rūgšteliškyje vyravo biogeninės antrinės organinės medžiagos (apie 50%). Vertinant tolimosios oro masių pernašos įtaką vietinės kilmės aerozolio dalelių formavimuisi ir kaitai, buvo nustatyta, kad vulkaninės kilmės aerozolio dalelės turi įtakos submikroninės aerozolio dalelių frakcijos koncentracijai, cheminei sudėčiai ir pasiskirstymui pagal dydį.
Finessi, Emanuela <1977>. "Chemical characterization of atmospheric secondary organic aerosol of biogenic and anthropogenic origin". Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2010. http://amsdottorato.unibo.it/2808/1/Finessi_Emanuela_tesi.pdf.
Finessi, Emanuela <1977>. "Chemical characterization of atmospheric secondary organic aerosol of biogenic and anthropogenic origin". Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2010. http://amsdottorato.unibo.it/2808/.
Gérard, Violaine. "Surfactants in atmospheric aerosols and their role on cloud formation". Thesis, Lyon, 2016. http://www.theses.fr/2016LYSE1216/document.
Clouds are essential components of the Earth’s hydrological system and climate but some aspects of their formation are still not completely understood. In particular, although Köhler theory predicts that surfactants should enhance cloud droplet activation, current models consider this role negligible. At the time of this PhD work, a few studies had started to demonstrate the contrary but atmospheric evidence for the role of these compounds was still missing and very little was known about their atmospheric concentrations, sources, and mechanism of action. The objective of this PhD work was to investigate these aspects. A method was developed to quantify surfactant concentrations in aerosols. Its application led to the first absolute atmospheric surfactants’ surface tension curves, in coastal PM2.5 aerosols in Sweden, and to the identification of the ratio C/CMC as the key parameter controlling the cloud-forming efficiency of aerosols. A second study revealed strong correlations between cloud occurrence and intrinsic surfactant properties in boreal PM1 aerosols in Finland, demonstrating for the first time the role of surfactants in cloud formation from direct atmospheric observations. The results predicted Cloud Condensation Nuclei numbers four times larger on average than when neglecting surfactant effects, showing the importance of including surfactant effects in cloud predictions models. The role of surfactants inferred from macroscopic measurements was confirmed by laboratory experiments on individual micron-sized droplets showing an increase of droplet growth in the presence of surfactants. Finally, observations from the different field studies indicated a biological origin for the surfactants present in atmospheric aerosols
Rinehart, Lynn Rebecca. "The origin of polar organic compounds in ambient fine particulate matter". abstract and full text PDF (free order & download UNR users only), 2005. http://0-gateway.proquest.com.innopac.library.unr.edu/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:3210293.
Bressi, Michael. "Les aerosols fins en Ile-de-France : chimie, sources et origines géographiques". Versailles-St Quentin en Yvelines, 2012. http://www.theses.fr/2012VERS0042.
This PhD thesis aims at documenting the chemical composition, the sources and the geographical origins of fine aerosols in the region of Paris, on an extended spatial and temporal scale. Five sampling sites -urban, suburban and rural- covering the entire region were used to sample PM2. 5 on a daily basis for one year. Major chemical compounds and source tracers were analysed. Statistical tools allowed the sources and the geographical origins of PM2. 5 to be determined, based on their chemical composition and back-trajectories analyses, respectively. Unexpectedly, PM2. 5 levels measured in Paris are amongst the lowest in Europe due to the flat orography of the region favouring the dispersion of pollutants. Aerosol pollution events were primarily due to the import of secondary aerosols -resulting from gas to particle conversion- stemming from Continental Europe. On the other hand, local sources (mainly biomass burning and road transport) only contribute a quarter of PM2. 5 levels on an annual scale
Garbarienė, Inga. "Atmosferos aerozolio submikroninės frakcijos dalelių kilmė, cheminė sudėtis bei formavimasis". Doctoral thesis, Lithuanian Academic Libraries Network (LABT), 2014. http://vddb.library.lt/obj/LT-eLABa-0001:E.02~2014~D_20140520_134611-00264.
The objective of the work was to investigate physical and chemical properties and sources of the atmospheric aerosol particles in the submicron fraction by combining different analytical techniques. The dependence of concentrations of organic and elemental carbon in different air masses was determined and the contribution of regional and local sources to the net aerosol particle pollution was estimated. Analysis of the size distribution of carbonaceous aerosol particles in background and urban areas was performed. Biogenic organic aerosol made up 15 % of the organic aerosol mass at the Preila atmospheric pollution research station, but in the North Atlantic air masses this factor was up to 50 %. Aerosol and stable isotope ratio mass spectrometry has revealed that traffic is the primary source of aerosol particles in the city, while biomass burning is the primary source at the Rūgšteliškis background station. It was determined that secondary anthropogenic organic compounds were dominating (76 %) in Vilnius, while in Rūgšteliškis secondary biogenic organic compounds made up 50 % of the total organic aerosol mass. The influence of the long-range air mass transport on the local origin aerosol particle formation and transformation has been evaluated and it has been shown that volcanic aerosol particles can significantly change the concentration, chemical composition and size distribution of local aerosol particles in the submicron range.
Roig, Rodelas Roger. "Chemical characterization, sources and origins of secondary inorganic aerosols measured at a suburban site in Northern France". Thesis, Lille 1, 2018. http://www.theses.fr/2018LIL1R017/document.
Tropospheric fine particles with aerodynamic diameters less than 2.5 µm (PM2.5) may impact health, climate and ecosystems. Secondary inorganic (SIA) and organic aerosols (OA) contribute largely to PM2.5. To understand their formation and origin, a 1-year campaign (August 2015 to July 2016) of inorganic precursor gases and PM2.5 water-soluble ions was performed at an hourly resolution at a suburban site in northern France using a MARGA 1S, complemented by mass concentrations of PM2.5, Black Carbon, nitrogen oxides and trace elements. The highest levels of ammonium nitrate (AN) and sulfate were observed at night in spring and during daytime in summer, respectively. A source apportionment study performed by positive matrix factorization (PMF) determined 8 source factors, 3 having a regional origin (sulfate-rich, nitrate-rich, marine) contributing to PM2.5 mass for 73-78%; and 5 a local one (road traffic, biomass combustion, metal industry background, local industry and dust) (22-27%). In addition, a HR-ToF-AMS (aerosol mass spectrometer) and a SMPS (particle sizer) were deployed during an intensive winter campaign, to gain further insight on OA composition and new particle formation, respectively. The application of PMF to the AMS OA mass spectra allowed identifying 5 source factors: hydrocarbon-like (15%), cooking-like (11%), oxidized biomass burning (25%), less- and more-oxidized oxygenated factors (16% and 33%, respectively). Combining the SMPS size distribution with the chemical speciation of the aerosols and precursor gases allowed the identification of nocturnal new particle formation (NPF) events associated to the formation of SIA, in particular AN
Roig, Rodelas Roger. "Chemical characterization, sources and origins of secondary inorganic aerosols measured at a suburban site in Northern France". Electronic Thesis or Diss., Université de Lille (2018-2021), 2018. http://www.theses.fr/2018LILUR017.
Tropospheric fine particles with aerodynamic diameters less than 2.5 µm (PM2.5) may impact health, climate and ecosystems. Secondary inorganic (SIA) and organic aerosols (OA) contribute largely to PM2.5. To understand their formation and origin, a 1-year campaign (August 2015 to July 2016) of inorganic precursor gases and PM2.5 water-soluble ions was performed at an hourly resolution at a suburban site in northern France using a MARGA 1S, complemented by mass concentrations of PM2.5, Black Carbon, nitrogen oxides and trace elements. The highest levels of ammonium nitrate (AN) and sulfate were observed at night in spring and during daytime in summer, respectively. A source apportionment study performed by positive matrix factorization (PMF) determined 8 source factors, 3 having a regional origin (sulfate-rich, nitrate-rich, marine) contributing to PM2.5 mass for 73-78%; and 5 a local one (road traffic, biomass combustion, metal industry background, local industry and dust) (22-27%). In addition, a HR-ToF-AMS (aerosol mass spectrometer) and a SMPS (particle sizer) were deployed during an intensive winter campaign, to gain further insight on OA composition and new particle formation, respectively. The application of PMF to the AMS OA mass spectra allowed identifying 5 source factors: hydrocarbon-like (15%), cooking-like (11%), oxidized biomass burning (25%), less- and more-oxidized oxygenated factors (16% and 33%, respectively). Combining the SMPS size distribution with the chemical speciation of the aerosols and precursor gases allowed the identification of nocturnal new particle formation (NPF) events associated to the formation of SIA, in particular AN
Basile, Isabelle. "Origine des aérosols volcaniques et continentaux de la carotte de glace de Vostok (Antarctique)". Phd thesis, Université Joseph Fourier (Grenoble ; 1971-2015), 1997. http://www.theses.fr/1997GRE10170.
Basile, Isabelle. "Origine des aérosols volcaniques et continentaux de la carotte de glace de Vostok (Antarctique)". Phd thesis, Grenoble 1, 1997. http://tel.archives-ouvertes.fr/tel-00756041.
Alvarez, Sergio L. Shauck Maxwell Eustace. "A 2007 aircraft-based study of plumes from biomass burning origin from Mexico and Central America advected over south Texas and the western Gulf of Mexico". Waco, Tex. : Baylor University, 2009. http://hdl.handle.net/2104/5326.
Fleury, Benjamin. "La haute atmosphère de la Terre primitive, une source de composés organiques prébiotiques". Thesis, Université Paris-Saclay (ComUE), 2015. http://www.theses.fr/2015SACLV012/document.
The origin of the organic matter on the early Earth is an important subject of research in planetology. This thesis presents an experimental study of the formation of organic compounds in the atmosphere of the early Earth investigating the reactivity of gaseous mixtures majority made of N2 and CO2. They present an important reactivity highlighted by the formation of gaseous products and solid products called tholins. The formation of these products points out CO2 as an efficiency source of carbon for the organic atmospheric growth. The identification of the gaseous products and the elemental analysis of the tholins showed a composition by C, N, H and O highlighting an efficiency coupling between the chemistry of these elements necessary for the formation of prebiotic compounds. This type of study have been applied then toTitan, which have a more reduced atmosphere, made of N2 and CH4, but, which contained also oxygenated trace species: principally CO. The addition of CO in the reactive medium involves also a coupling between the chemistry of O and the C, N, H chemistry currently considered for Titan. Finally I propose and investigate experimentally two phenomena, which may involve a chemical evolution of the aerosols of Titan during their sedimentation to the surface. First, an exposition of tholins to VUV photons, characteristic of the thermosphere of Titan, involves a selective depletion of amines function in favor of aliphatic functions. Second, an irradiation by UV photons of condensed species at the surface of tholins involves a reactivity of the solid species in interaction with the tholins, changing their chemical composition
Vallelonga, Paul Travis. "Measurement of Lead Isotopes in Snow and Ice from Law Dome and other sites in Antarctica to characterize the Lead and seek evidence of its origin". Thesis, Curtin University, 2002. http://hdl.handle.net/20.500.11937/2580.
Querol, Balaguer María Ángeles. "Estudio comparativo de los niveles, composición y origen de la contaminación por aerosoles en el cluster cerámico de la provincia de Castellón y su capital". Doctoral thesis, Universitat Jaume I, 2013. http://hdl.handle.net/10803/669133.
Vallelonga, Paul Travis. "Measurement of Lead Isotopes in Snow and Ice from Law Dome and other sites in Antarctica to characterize the Lead and seek evidence of its origin". Curtin University of Technology, School of Applied Science, 2002. http://espace.library.curtin.edu.au:80/R/?func=dbin-jump-full&object_id=14018.
Particular attention was given to the quantity of Pb added to the samples during the decontamination and sample storage stages of the sample preparation process. These stages, including the use of a stainless steel chisel for the decontamination, contributed ~5.2 pg to the total sample analysed, amounting to a concentration increase of ~13 fg g-1. In comparison, the mass spectrometer ion source contributed typically 89 +/- 19 fg to the blank, however its influence depended upon the amount of Pb available for analysis and so had the greatest impact when small volumes of samples with a very low concentration were analysed. As a consequence of these careful investigations of the Pb blank contributions to the samples, the corrections made to the Pb isotopic ratios and concentrations measured are smaller than previously reported evaluations of Pb in Antarctica by thermal ionisation mass spectrometry. The data indicate that East Antarctica was relatively pristine until -1884 AD, after which the first influence of anthropogenic Pb in Law Dome is observed. "Natural", pre-industrial, background concentrations of Pb and Ba were - 0.4 pg/g and - 1.3 pg/g, respectively, with Pb isotopic compositions within the range 206Pb/207Pb = 1.20 - 1.25 and 208Pb/207Pb = 2.46 - 2.50 and an average rock and soil dust Pb contribution of 8-12%. A major pollution event was observed at Law Dome between 1884 and 1908 AD, elevating the Pb concentration fourfold and changing 206Pb/207Pb ratios in the ice to ~1.12. Based on Pb isotopic systematics and Pb emissions statistics, this was attributed to Pb mined at Broken Hill and smelted at Broken Hill and Port Pirie, Australia.
Anthropogenic Pb inputs to Law Dome were most significant from ~1900 to 1910 and from ~1960 to 1980. During the 20th century, Ba concentrations were consistently higher than "natural" levels. This was attributed to increased dust production, suggesting the influence of climate change and/or changes in land coverage with vegetation. Law Dome ice dated from 1814 AD to 1819 AD was analysed for Pb isotopes and Pb, Ba and Bismuth (Bi) concentrations to investigate the influence of the 1815 AD volcanic eruption of Tambora, Indonesia. The presence of volcanic debris in the core samples was observed from late-1816 AD to 1818 AD as an increase in sulphate concentrations and electrical conductivity of the ice. Barium concentrations were approximately three times higher than background levels from mid-1816 to mid1818, consistent with increased atmospheric loading of rock and soil dust, while enhanced Pb/Ba and Bi/Ba ratios, associated with deposition of volcanic debris, were observed at mid-1814 and from early-1817 to mid-1818. From the results, it appeared likely that Pb emitted from Tambora was removed from the atmosphere within the 1.6 year period required to transport aerosols to Antarctica. Increased Pb and Bi concentrations observed in Law Dome ice ~1818 AD were attributed to either increased heavy metal emissions from Mount Erebus, or increased fluxes of heavy metals to the Antarctic ice sheet resulting from climate and meteorological modifications following the Tambora eruption.
A non-continuous series of Law Dome snow core samples dating from 1980 to 9185 AD were analysed to investigate seasonal variations in the deposition of Pb and Ba. It was found that Pb and Ba at Law Dome do exhibit seasonal variations in deposition, with higher concentrations of Pb and Ba usually observed during Summer and lower concentrations of Pb and Ba usually observed during the Autumn and Spring seasons. At Law Dome, broad patterns of seasonal Pb and Ba deposition are evident however these appear to be punctuated by short-term deposition events or may even be composed of a continuum of short-term deposition events. This variability suggests that complex meteorological systems are responsible for the transport of Pb and Ba to Law Dome, and probably Antarctica in general.
Cachier-Rivault, Hélène. "Approche isotopique du cycle atmospherique du carbone particulaire". Paris 7, 1987. http://www.theses.fr/1987PA077061.
Leung, Fok-Yan Thomas. "Elucidation of the Origins of Stratospheric Sulfate Aerosols by Isotopic Methods". Thesis, 2003. https://thesis.library.caltech.edu/2233/5/4SO2.pdf.
Hildemann, Lynn Mary. "A study of the origin of atmospheric organic aerosols". Thesis, 1990. https://thesis.library.caltech.edu/1957/1/Hildemann_lm_1990.pdf.
Lai, Sin-you, e 賴信佑. "Aerosol property and air mass origin at high-alpine mountain in central Taiwan". Thesis, 2009. http://ndltd.ncl.edu.tw/handle/47002005971172846209.
國立中央大學
環境工程研究所
97
The tremendous amounts of aerosols and gas pollutants produced in Indo China will affect the downwind region as they are transported in a long distance. Taiwan is one of the best places to observe these transported pollutants as it is located in the downwind region. To circumbent the interference from ground level pollution, this study observed atmospheric aerosols at Mt. Lulin (2,862 m above sea level) from July 2007 to April 2008. The goal is to resolve the differences of aerosol property between biomass burning (BB) and non-biomass burning (NBB) periods. The PM2.5 level is three-fold during BB period as compared to that of NBB period. The PM2.5 ammonium ion, sulfate, and nitrate levels are 1.50 µg m-3, 4.06 µg m-3, and 0.50 µg m-3, respectively. Notably, the PM2.5 potassium ion as one of the markers for BB was four-fold as high as that during NBB period. As for the levels of the resolved carbonaceous fractions, organic carbons (OC) were increased significantly, while only EC1-OP was increased for elemental carbon (EC). Moreover, the mean values of water-soluble OC, levoglucosan, and low molecular-weight diacids during BB period were 3.2, 3, and 4.5 times, respecticely, in contrast to those during NBB period. Trajectory analysis for the air masses during observation period shows that the levels of aerosol components were the lowest for oceanic origin. It also shows that PM10-2.5 and calcium ion from China continent were apparently higher than those from other transport paths probably due to the influence of Asian dust. For the air masses from BB source region via southern China, PM2.5, potassion ion, oxalic acid, and levoglucosan were all higher during BB period than that of NBB period. For the aerosol morphology during BB period, the analysis of scanning electron microscopy reveals that rectangular crystal type is around 70-80% in the number of the observed aerosol particles followed by tar ball type and grape chain aggregrate takes the least. Different size cut samplers were adopted at Mt. Lulin to collect aerosols when in the uprising convective cloud, little difference was found for PM1 and PM2.5 aerosol components; however, a difference was exist for PM1 and TSP. Among aerosol components, the scavenging ratio was highest at 0.41 for nitrate followed by ammonium ion and sulfate. The scavenging ratio for OC and EC were 0.20 and 0.22, respectively. During cloud affecting period, the levels of PM2.5 ammonium ion, sulfate, and nitrate were significantly increased, which indicates anthropogenic pollutants were entrained in the cloud.