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1
Hajigholizadeh, Mohammad. « Water Quality Modelling Using Multivariate Statistical Analysis and Remote Sensing in South Florida ». FIU Digital Commons, 2016. http://digitalcommons.fiu.edu/etd/2992.
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The overall objective of this dissertation research is to understand the spatiotemporal dynamics of water quality parameters in different water bodies of South Florida. Two major approaches (multivariate statistical techniques and remote sensing) were used in this study. Multivariate statistical techniques include cluster analysis (CA), principal component analysis (PCA), factor analysis (FA), discriminant analysis (DA), absolute principal component score-multiple linear regression (APCS-MLR) and PMF receptor modeling techniques were used to assess the water quality and identify and quantify the potential pollution sources affecting the water quality of three major rivers of South Florida. For this purpose, a 15-year (2000–2014) data set of 12 water quality variables, and about 35,000 observations were used. Agglomerative hierarchical CA grouped 16 monitoring sites into three groups (low pollution, moderate pollution, and high pollution) based on their similarity of water quality characteristics. DA, as an important data reduction method, was used to assess the water pollution status and analysis of its spatiotemporal variation. PCA/FA identified potential pollution sources in wet and dry seasons, respectively, and the effective mechanisms, rules, and causes were explained. The APCS-MLR and PMF models apportioned their contributions to each water quality variable.
Also, the bio-physical parameters associated with the water quality of the two important water bodies of Lake Okeechobee and Florida Bay were investigated based on remotely sensed data. The principal objective of this part of the study is to monitor and assess the spatial and temporal changes of water quality using the application of integrated remote sensing, GIS data, and statistical techniques. The optical bands in the region from blue to near infrared and all the possible band ratios were used to explore the relation between the reflectance of a waterbody and observed data. The developed MLR models appeared to be promising for monitoring and predicting the spatiotemporal dynamics of optically active and inactive water quality characteristics in Lake Okeechobee and Florida Bay. It is believed that the results of this study could be very useful to local authorities for the control and management of pollution and better protection of water quality in the most important water bodies of South Florida.
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Crow, Mason W. « Multiple sensor credit apportionment ». Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 2002. http://library.nps.navy.mil/uhtbin/hyperion-image/02Jun%5FCrow.pdf.
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Mayer, Stefan. « Formulary apportionment for the internal market / ». [München] : [s.n.], 2008. http://opac.nebis.ch/cgi-bin/showAbstract.pl?sys=000259620.
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Wagener, Andreas. « Evolutionary Tax Competition with Formulary Apportionment ». WU Vienna University of Economics and Business, Universität Wien, 2017. http://epub.wu.ac.at/5899/1/SSRN%2Did3078969.pdf.
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Evolutionary stability is a necessary condition for imitative dynamics of policy learning
and innovation to come to a rest. We apply this concept to profit tax competition
in a regime where a common and consolidated profit tax base for multi-jurisdictional
firms is divided among governments by means of formulary apportionment. In evolutionary
play, governments exhibit aggregate-taking behavior: when comparing
their performance with others, they ignore their impact on the consolidated tax
base. Consequently, evolutionarily stable tax rates are less efficient than tax rates
in best-response tax competition.Series: WU International Taxation Research Paper Series
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Maier, Sebastian. « Biproportional apportionment methods : constraints, algorithms, and simulation / ». München : Verl. Dr. Hut, 2009. http://bvbr.bib-bvb.de:8991/F?func=service&doc_library=BVB01&doc_number=017317892&line_number=0001&func_code=DB_RECORDS&service_type=MEDIA.
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Carter-Brown, Clinton Geoffrey. « Voltage drop apportionment in Eskom's distribution networks ». Master's thesis, University of Cape Town, 2002. http://hdl.handle.net/11427/5258.
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Maier, Sebastian. « Biproportional apportionment methods constraints, algorithms, and simulation ». München Verl. Dr. Hut, 2008. http://d-nb.info/992645034/04.
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Laurie, Elizabeth Helen. « Source apportionment of urban atmospheric polycyclic aromatic hydrocarbons ». Thesis, University of Birmingham, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.273558.
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Muir, David. « Source apportionment of PMâ‚â‚€ during pollution episodes ». Thesis, University of the West of England, Bristol, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.274699.
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Christensen, Jonathan Casey. « Bayesian Pollution Source Apportionment Incorporating Multiple Simultaneous Measurements ». BYU ScholarsArchive, 2012. https://scholarsarchive.byu.edu/etd/3005.
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We describe a method to estimate pollution profiles and contribution levels for distinct prominent pollution sources in a region based on daily pollutant concentration measurements from multiple measurement stations over a period of time. In an extension of existing work, we will estimate common source profiles but distinct contribution levels based on measurements from each station. In addition, we will explore the possibility of extending existing work to allow adjustments for synoptic regimes—large scale weather patterns which may effect the amount of pollution measured from individual sources as well as for particular pollutants. For both extensions we propose Bayesian methods to estimate pollution source profiles and contributions.
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Chreiky, Robert. « Informed Non-Negative Matrix Factorization for Source Apportionment ». Thesis, Littoral, 2017. http://www.theses.fr/2017DUNK0464/document.
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Le démélange de sources pour la pollution de l'air peut être formulé comme un problème de NMF en décomposant la matrice d'observation X en le produit de deux matrices non négatives G et F, respectivement la matrice de contributions et de profils. Généralement, les données chimiques sont entâchées d'une part de données aberrantes. En dépit de l'intérêt de la communauté pour les méthodes de NMF, elles souffrent d'un manque de robustesse à un faible nombre de données aberrantes et aux conditions initiales et elles fournissent habituellement de multiples minimas. En conséquence, cette thèse est orientée d'une part vers les méthodes de NMF robustes et d'autre part vers les NMF informées qui utilisent une connaissance experte particulière. Deux types de connaissances sont introduites dans la matrice de profil F. La première hypothèse est la connaissance exacte de certaines composantes de la matrice F tandis que la deuxième information utilise la propriété de somme-à-1 de chaque ligne de la matrice F. Une paramétrisation qui tient compte de ces deux informations est développée et des règles de mise à jour dans le sous-espace des contraintes sont proposées. L'application cible qui consiste à identifier les sources de particules dans l'air dans la région côtière du nord de la France montre la pertinence des méthodes proposées. Dans la série d'expériences menées sur des données synthétiques et réelles, l'effet et la pertinence des différentes informations sont mises en évidence et rendent les résultats de factorisation plus fiablesSource apportionment for air pollution may be formulated as a NMF problem by decomposing the data matrix X into a matrix product of two factors G and F, respectively the contribution matrix and the profile matrix. Usually, chemical data are corrupted with a significant proportion of abnormal data. Despite the interest for the community for NMF methods, they suffer from a lack of robustness to a few abnormal data and to initial conditions and they generally provide multiple minima. To this end, this thesis is oriented on one hand towards robust NMF methods and on the other hand on informed NMF by using some specific prior knowledge. Two types of knowlodge are introduced on the profile matrix F. The first assumption is the exact knowledge on some of flexible components of matrix F and the second hypothesis is the sum-to-1 constraint on each row of the matrix F. A parametrization able to deal with both information is developed and update rules are proposed in the space of constraints at each iteration. These formulations have been appliede to two kind of robust cost functions, namely, the weighted Huber cost function and the weighted αβ divergence. The target application-namely, identify the sources of particulate matter in the air in the coastal area of northern France - shows relevance of the proposed methods. In the numerous experiments conducted on both synthetic and real data, the effect and the relevance of the different information is highlighted to make the factorization results more reliable
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Guastella, Maxence. « Les principes directeurs des répartitions de fonds en procédure collective ». Electronic Thesis or Diss., Université Côte d'Azur, 2022. http://theses.univ-cotedazur.fr/2022COAZ0044.
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Comment payer les créanciers d'une entreprise placée sous procédure collective lorsque cela n'est pas possible ? Telle est la délicate question que les répartitions de fonds se proposent de résoudre. Le plus souvent, en effet, le montant de l'actif à distribuer est inférieur à celui du passif à apurer. Or, le système juridique ne saurait créer un actif pour corriger cette balance négative. Face à une telle pénurie, le Droit ne peut donc guère qu'arbitrer entre les multiples intérêts en présence. Mais la façon dont il opère cet arbitrage est éminemment problématique. Le régime des répartitions est d'une telle complexité qu'il en devient indéchiffrable, à telle enseigne qu'il est pour ainsi dire impossible de les réaliser correctement. Déterminer le périmètre de l'actif distribuable, identifier les personnes autorisées à participer aux répartitions et les attributs à prendre en considération, définir l'ordre des paiements, c'est-à-dire établir le classement des créanciers et fixer l'ordre des distributions, et rectifier les éventuelles erreurs de répartition, constituent autant d'étapes aussi nécessaires qu'impraticables. Afin d'y voir plus clair, doctrine et praticiens ont exhorté les pouvoirs publics à dégager un ensemble de principes directeurs, et, faute de réponse à cette sollicitation, ont eux-mêmes entrepris leur formalisation. Partant du constat qu'une procédure collective s'analyse en une saisie collective, et, par suite, en une procédure de distribution collective régie par des règles essentielles qui lui sont propres et distinctes de celles gouvernant le droit commun de l'exécution forcée et des procédures de distribution, la présente étude s'appuie sur ces travaux pour livrer une présentation des répartitions de fonds en procédure collective sous la forme d'un système dynamique de principes directeurs destinée à clarifier leur régime juridique et à le rendre praticableHow can the creditors of a company that is the subject of collective insolvency proceedings be paid when it is not possible to do so ? This is the sensitive issue that fund apportionments seek to resolve. Often, the amount of assets to be distributed falls short of liabilities to be discharged. Nevertheless, the legal system cannot create an asset to correct this negative balance. In view of the lack of funds, the law can only arbitrate between the many interests involved. However, the way in which such arbitration works is extremely problematic. The apportionment procedure is so complex as to be incomprehensible, to the extent that it is more or less impossible to carry it out in a satisfactory manner. Determining the perimeter of distributable assets ; identifying the persons authorized to participate in apportionments and the attributes to be taken into consideration ; defining the order of payments, i.e., prioritizing creditors and establishing an order for distributions ; and correcting any apportionment errors are all steps that are at once necessary and unworkable. In order to make sense of all this, legal theorists and practitioners have urged the authorities to issue guidelines and, in the absence of any response to their request, have them-selves set about drafting some. Starting from the observation that collective insolvency proceedings can be seen as a collective seizure, and, therefore, as collective distribution governed by essential rules that are specific to it and distinct from those governing the ordinary law of compulsory enforcement and distribution proceedings, this study draws from such work in order to present fund apportionments in collective insolvency proceedings in the form of a dynamic system of guidelines seeking to clarify their legal regime and render it practicable
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Gietl, Johanna Katharina. « Source apportionment of airborne particulate matter in Münster, Germany / ». Münster, 2008. http://opac.nebis.ch/cgi-bin/showAbstract.pl?sys=000252283.
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Xie, Han. « Source apportionment of particulate matter 2.5 in Southeast Ohio ». Ohio University / OhioLINK, 2002. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1175010260.
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Chowdhury, Raziya Sultana. « Size distribution and source apportionment of airborne particulate matter ». Thesis, Queensland University of Technology, 2021. https://eprints.qut.edu.au/226864/1/Raziya%20Sultana_Chowdhury_Thesis.pdf.
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The study investigated the viability of employing a receptor modelling technique to characterize the sources of atmospheric aerosols from different air quality datasets. Chemical speciated datasets from two Brisbane sites; particle size distribution and organic mass spectral data from Garden Island, Western Australia have been analysed. The investigation produced quantitative information about the nature of the dominant primary and secondary emission sources of atmospheric aerosols at the study sites. Such information can aid air quality management.
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Lingwall, Jeff W. « Bayesian and Positive Matrix Factorization approaches to pollution source apportionment / ». Diss., CLICK HERE for online access, 2006. http://contentdm.lib.byu.edu/ETD/image/etd1295.pdf.
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O'Leary, Kevin C. « Source apportionment of volatile organic compounds in urban micro-environments ». Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape8/PQDD_0015/MQ48454.pdf.
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Lo, Chi On. « Time-based source apportionment of air pollutants for Hong Kong / ». View abstract or full-text, 2007. http://library.ust.hk/cgi/db/thesis.pl?AMCE%202007%20LO.
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Thesis (M.Phil.)--Hong Kong University of Science and Technology, 2007.M.Phil. in Atmospheric Environmental Science. Includes bibliographical references (leaves 82-83). Also available in electronic version.
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Balachandran, Sivaraman. « The development, application and evaluation of advanced source apportionment methods ». Diss., Georgia Institute of Technology, 2013. http://hdl.handle.net/1853/50279.
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Ambient and indoor air pollution is a major cause of premature mortality, and has been associated with more than three million preventative deaths per year worldwide. Most of these health impacts are from the effects from fine particulate matter. It is suspected that PM2.5 health effects vary by composition, which depends on the mixture of pollutants emitted by sources. This has led to efforts to estimate relationships between sources of PM2.5 and health effects. The health effects of PM2.5 may be preferentially dependent on specific species; however, recent work has suggested that health impacts may actually be caused by the net effect of the mixture of pollutants which make up PM2.5. Recently, there have been efforts to use source impacts from source apportionment (SA) studies as a proxy for these multipollutant effects. Source impacts can be quantified using both receptor and chemical transport models (RMs and CTMs), and have both advantages and limitations for their use in health studies.
In this work, a technique is developed that reconciles differences between source apportionment (SA) models by ensemble-averaging source impacts results from several SA models. This method uses a two-step process to calculate the ensemble average. An initial ensemble average is used calculate new estimates of uncertainties for the individual SA methods that are used in the ensemble. Next, an updated ensemble average is calculated using the SA method uncertainties as weights. Finally, uncertainties of the ensemble average are calculated using propagation of errors that includes covariance terms. The ensemble technique is extended to include a Bayesian formulation of weights used in ensemble-averaging source impacts. In a Bayesian approach, probabilistic distributions of the parameters of interest are estimated using prior distributions, along with information from observed data.
Ensemble averaging results in updated estimates of source impacts with lower uncertainties than individual SA methods. Overall uncertainties for ensemble-averaged source impacts were ~45 - 74%. The Bayesian approach also captures the expected seasonal variation of biomass burning and secondary impacts. Sensitivity analysis found that using non-informative prior weighting performed better than using weighting based on method-derived uncertainties. The Bayesian-based source impacts for biomass burning correlate better with observed levoglucosan (R2=0.66) and water soluble potassium (R2=0.63) than source impacts estimated using more traditional methods, and more closely agreed with observed total mass. Power spectra of the time series of biomass burning source impacts suggest that profiles/factors associated with this source have the greatest variability across methods and locations.
A secondary focus of this work is to examine the impacts of biomass burning. First a field campaign was undertaken to measure emissions from prescribed fires. An emissions factor of 14±17 g PM2.5/kg fuel burned was determined. Water soluble organic carbon (WSOC) was highly correlated with potassium (K) (R2=.93) and levoglucosan (R2=0.98). Results using a biomass burning source profile derived from this work further indicate that source apportionment is sensitive to levels of potassium in biomass burning source profiles, underscoring the importance of quantifying local biomass burning source profiles. Second, the sensitivity of ambient PM2.5 to various fire and meteorological parameters in was examined using the method of principle components regression (PCR) to estimate sensitivity of PM2.5 to fire data and, observed and forecast meteorological parameters. PM2.5 showed significant sensitivity to PB, with a unit-based sensitivity of 3.2±1 µg m-3 PM2.5 per 1000 acres burned. PM2.5 had a negative sensitivity to dispersive parameters such as wind speed.
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Nowicki, David R. « Reliability allocation and apportionment : addressing redundancy and life-cycle cost / ». Thesis, This resource online, 1993. http://scholar.lib.vt.edu/theses/available/etd-08042009-040416/.
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O'Leary, Kevin C. (Kevin Charles) Carleton University Dissertation Engineering Civil and Environmental. « Source apportionment of volatile organic compounds in urban micro-environments ». Ottawa, 1999.
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Blake, Daniel B. « Source Apportionment of Wastewater Using Bayesian Analysis of Fluorescence Spectroscopy ». BYU ScholarsArchive, 2014. https://scholarsarchive.byu.edu/etd/4216.
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This research uses Bayesian analysis of fluorescence spectroscopy results to determine if wastewater from the Heber Valley Special Service District (HVSSD) lagoons in Midway, UT has seeped into the adjacent Provo River. This flow cannot be directly measured, but it is possible to use fluorescence spectroscopy to determine if there is seepage into the river.Fluorescence spectroscopy results of water samples obtained from HVSSD lagoons and from upstream and downstream in the Provo River were used to conduct this statistical analysis. The fluorescence 'fingerprints' for the upstream and lagoon samples were used to deconvolute the two sources in a downstream sample in a manner similar to the tools and methods discussed in the literature and used for source apportionment of air pollutants. The Bayesian statistical method employed presents a novel way of conducting source apportionment and identifying the existence of pollution.This research demonstrates that coupling fluorescence spectroscopy with Bayesian statistical methods allows researchers to determine the degree to which a water source has been contaminated by a pollution source. This research has applications in determining the affect sanitary wastewater lagoons and other lagoons have on an adjacent river due to groundwater seepage. The method used can be applied in scenarios where direct collection of hydrogeologic data is not possible. This research demonstrates that the Bayesian chemical mass balance model presented is a viable method of performing source apportionment.
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Lingwall, Jeff William. « Bayesian and Positive Matrix Factorization approaches to pollution source apportionment ». BYU ScholarsArchive, 2006. https://scholarsarchive.byu.edu/etd/430.
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The use of Positive Matrix Factorization (PMF) in pollution source apportionment (PSA) is examined and illustrated. A study of its settings is conducted in order to optimize them in the context of PSA. The use of a priori information in PMF is examined, in the form of target factor profiles and pulling profile elements to zero. A Bayesian model using lognormal prior distributions for source profiles and source contributions is fit and examined.
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Friend, Adrian J. « Multi-criteria ranking and source apportionment of airborne particulate matter ». Thesis, Queensland University of Technology, 2012. https://eprints.qut.edu.au/60468/1/Adrian_Friend_Thesis.pdf.
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Particulate matter research is essential because of the well known significant adverse effects of aerosol particles on human health and the environment. In particular, identification of the origin or sources of particulate matter emissions is of paramount importance in assisting efforts to control and reduce air pollution in the atmosphere.
This thesis aims to: identify the sources of particulate matter; compare pollution conditions at urban, rural and roadside receptor sites; combine information about the sources with meteorological conditions at the sites to locate the emission sources; compare sources based on particle size or mass; and ultimately, provide the basis for control and reduction in particulate matter concentrations in the atmosphere.
To achieve these objectives, data was obtained from assorted local and international receptor sites over long sampling periods. The samples were analysed using Ion Beam Analysis and Scanning Mobility Particle Sizer methods to measure the particle mass with chemical composition and the particle size distribution, respectively.
Advanced data analysis techniques were employed to derive information from large, complex data sets. Multi-Criteria Decision Making (MCDM), a ranking method, drew on data variability to examine the overall trends, and provided the rank ordering of the sites and years that sampling was conducted. Coupled with the receptor model Positive Matrix Factorisation (PMF), the pollution emission sources were identified and meaningful information pertinent to the prioritisation of control and reduction strategies was obtained.
This thesis is presented in the thesis by publication format. It includes four refereed papers which together demonstrate a novel combination of data analysis techniques that enabled particulate matter sources to be identified and sampling site/year ranked.
The strength of this source identification process was corroborated when the analysis procedure was expanded to encompass multiple receptor sites. Initially applied to identify the contributing sources at roadside and suburban sites in Brisbane, the technique was subsequently applied to three receptor sites (roadside, urban and rural) located in Hong Kong. The comparable results from these international and national sites over several sampling periods indicated similarities in source contributions between receptor site-types, irrespective of global location and suggested the need to apply these methods to air pollution investigations worldwide. Furthermore, an investigation into particle size distribution data was conducted to deduce the sources of aerosol emissions based on particle size and elemental composition. Considering the adverse effects on human health caused by small-sized particles, knowledge of particle size distribution and their elemental composition provides a different perspective on the pollution problem.
This thesis clearly illustrates that the application of an innovative combination of advanced data interpretation methods to identify particulate matter sources and rank sampling sites/years provides the basis for the prioritisation of future air pollution control measures. Moreover, this study contributes significantly to knowledge based on chemical composition of airborne particulate matter in Brisbane, Australia and on the identity and plausible locations of the contributing sources. Such novel source apportionment and ranking procedures are ultimately applicable to environmental investigations worldwide.
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Engstrom, Erik J. « How party competition constructs democracy : strategic redistricting and American electoral development / ». Diss., Connect to a 24 p. preview or request complete full text in PDF format. Access restricted to UC IP addresses, 2002. http://wwwlib.umi.com/cr/ucsd/fullcit?p3094612.
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Dergaoui, Hilel. « Modélisation d'une population d'aérosols multi-sources et recherche des contributions de chaque source à l'échelle urbaine avec le modèle de dispersion CHIMERE ». Phd thesis, Université Paris-Est, 2012. http://pastel.archives-ouvertes.fr/pastel-00806520.
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L'objectif de cette thèse est le développement et la validation d'un modèle numérique de la dynamique des particules en mélange externe et résolu en taille. Afin de suivre plusieurs compositions chimiques par classe de tailles, une nouvelle approche est présentée dans laquelle la composition chimique des particules est elle-même discrétisée suivant la fraction d'un ou plusieurs des constituants chimiques (e.g. suie, sulfate). Cette approche a pour but de mieux simuler l'évolution d'une population de particules à l'échelle locale et de particulariser des compositions chimiques typiques de certaines sources. Dans l'atmosphère, les particules interagissent essentiellement entre elles et avec les polluants gazeux par coagulation et condensation/évaporation. La première partie de la thèse a été consacrée à l'élaboration du modèle pour la coagulation, processus physique qui s'avère le plus complexe à modéliser selon notre approche du mélange externe. Dans un premier temps, les équations de la coagulation en mélange externe sont présentées et discrétisées suivant un nombre arbitraire de classe de tailles et de compositions chimiques. Plusieurs simulations numériques ont ensuite été effectuées avec ce modèle sur un même cas d'étude, en utilisant deux, trois et quatre composants chimiques. On vérifie à chaque fois que les résultats de la simulation numérique en mélange externe sont cohérents avec ceux du mélange interne du cas d'étude. Les résultats de ces simulations permettent d'apprécier l'effet de mélange de la coagulation qui produit, à partir de particules monocomposées, des particules bicomposées et tricomposées. Étant donné la complexité croissante d'un tel modèle, une attention toute particulière a été portée à l'implémentation numérique et à l'optimisation des algorithmes choisis. L'extension de cette approche à la condensation/évaporation constitue le prochain développement de ce modèle, nous en posons les bases théoriques en annexe. S'il existe aujourd'hui des données de mesure résolues en taille (SMPS), il n'y en a pas encore qui puissent être réellement validantes pour ce modèle de mélange externe, c'est-à-dire qui distinguent quantitativement plusieurs compositions chimiques par classe de taille. Aussi, dans la seconde partie de la thèse, nous avons envisagé le protocole d'une expérience en chambre permettant de mettre en évidence le mélange par coagulation de deux populations de particules de compositions différentes et d'apporter des données validantes pour le modèle développé. Deux séries d'expériences ont été menées, la première dans la chambre de grand volume CESAM et la seconde, dans le réacteur de petit volume de l'INERIS. La première série a mis en évidence l'homococagulation de chaque distribution polydispersée prise séparément et dans une moindre mesure, l'hétérocoagulation des deux distributions de nature différentes (NaBr et KBr) entre elles. La seconde série a montré la possibilité d'observer simultanément deux distributions monodispersées de particules de compositions différentes (CaSO4 et KBr), prérequis pour ce cas. Au final, les résultats de mesure se sont avérés insuffisants pour produire des données validantes pour le modèle, à cause du trop grand écart-type des distributions polydispersées dans la chambre de grand volume et à cause du dépôt au paroi qui domine dans le réacteur de petit volume. Des analyses au microscope électronique ont cependant attesté de la présence de particules issues de la coagulation entre les deux natures. A la suite des différentes expériences menées, nous revenons sur le protocole envisagé et proposons quelques pistes d'améliorations
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Lee, Sangil. « Characterization and source apportionment of PM2.5 in the Southeastern United States ». Diss., Available online, Georgia Institute of Technology, 2006, 2006. http://etd.gatech.edu/theses/available/etd-11062006-122838/.
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Thesis (Ph. D.)--Civil and Environmental Engineering, Georgia Institute of Technology, 2007.Wang, Yuhang, Committee Member ; Chang, Michael, Committee Member ; Bergin, Michael, Committee Member ; Mulholland, James, Committee Member ; Russell, Armistead, Committee Chair.
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Elmquist, Marie. « Measurement and source apportionment of ubiquitous soot black carbon in sediments ». Doctoral thesis, Stockholm : Department of Applied Environmental Science, Stockholm university, 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-6638.
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Al-Saadi, Lubna Saleh. « PM2.5 source apportionment and mass closure study in Doha city, Qatar ». Thesis, University of Birmingham, 2018. http://etheses.bham.ac.uk//id/eprint/8544/.
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This study aims to identify key sources that contribute to fine particulate matter (PM2.5) mass concentrations in Doha city, Qatar. Specifically, to determine the increase in PM2.5 mass caused by dust events, by comparing abundance and composition between the dust events season ‘the summer season’ and non-dust event season ‘the winter season’. Knowing PM2.5 sources in Doha will help to 1) identify the predominant (natural or anthropogenic) sources responsible for particulate matter (PM) exceedances of the daily and annual air quality standards, 2) ensure an appropriate focus on controlling major anthropogenic sources, and 3) evaluate the current air quality standards and potential improvements to the allowable margin of tolerance for PM limit and the number of allowed exceedances to take appropriate account of natural sources. Two parallel sampling campaigns at two urban sites in Doha, namely Al-Corniche (AC) and Qatar University (QU) were conducted during the winter of 2014/2015 and the summer of 2015 using low volume samplers. Chemical analysis of minerals, trace metals, soluble inorganic ions, organic and elemental carbon was carried out on PM2.5 samples. Subsequently, a mass closure analysis, and a source apportionment by means of positive matrix factorisation (PMF-5) were performed. The mass closure solution found a good closure between the samples’ gravimetric mass and the reconstructed mass of the chemical constituents determined on those samples. However, mass discrepancies ranged between -5 and +12% were found between reconstructed mass and gravimetric measured mass as a result of using different filters substances (Teflon & Quartz) to collect PM2.5 samples with contradictory behavior in retaining and releasing organic carbon and ammonium nitrate. Then comparing the sum of chemical constituents from both filters to the mass collected on the Teflon filters.
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Venturini, Elisa <1985>. « Application of innovative methods of source apportionment in air contamination assessment ». Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2013. http://amsdottorato.unibo.it/5584/1/elisa_venturini_tesi.pdf.
Texte intégralRésumé :
In this work, new tools in atmospheric pollutant sampling and analysis were applied in order to go deeper in source apportionment study. The project was developed mainly by the study of atmospheric emission sources in a suburban area influenced by a municipal solid waste incinerator (MSWI), a medium-sized coastal tourist town and a motorway. Two main research lines were followed. For what concerns the first line, the potentiality of the use of PM samplers coupled with a wind select sensor was assessed. Results showed that they may be a valid support in source apportionment studies. However, meteorological and territorial conditions could strongly affect the results. Moreover, new markers were investigated, particularly focusing on the processes of biomass burning. OC revealed a good biomass combustion process indicator, as well as all determined organic compounds. Among metals, lead and aluminium are well related to the biomass combustion. Surprisingly PM was not enriched of potassium during bonfire event.
The second research line consists on the application of Positive Matrix factorization (PMF), a new statistical tool in data analysis. This new technique was applied to datasets which refer to different time resolution data. PMF application to atmospheric deposition fluxes identified six main sources affecting the area. The incinerator’s relative contribution seemed to be negligible. PMF analysis was then applied to PM2.5 collected with samplers coupled with a wind select sensor. The higher number of determined environmental indicators allowed to obtain more detailed results on the sources affecting the area. Vehicular traffic revealed the source of greatest concern for the study area. Also in this case, incinerator’s relative contribution seemed to be negligible. Finally, the application of PMF analysis to hourly aerosol data demonstrated that the higher the temporal resolution of the data was, the more the source profiles were close to the real one.
31
Venturini, Elisa <1985>. « Application of innovative methods of source apportionment in air contamination assessment ». Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2013. http://amsdottorato.unibo.it/5584/.
Texte intégralRésumé :
In this work, new tools in atmospheric pollutant sampling and analysis were applied in order to go deeper in source apportionment study. The project was developed mainly by the study of atmospheric emission sources in a suburban area influenced by a municipal solid waste incinerator (MSWI), a medium-sized coastal tourist town and a motorway. Two main research lines were followed. For what concerns the first line, the potentiality of the use of PM samplers coupled with a wind select sensor was assessed. Results showed that they may be a valid support in source apportionment studies. However, meteorological and territorial conditions could strongly affect the results. Moreover, new markers were investigated, particularly focusing on the processes of biomass burning. OC revealed a good biomass combustion process indicator, as well as all determined organic compounds. Among metals, lead and aluminium are well related to the biomass combustion. Surprisingly PM was not enriched of potassium during bonfire event.
The second research line consists on the application of Positive Matrix factorization (PMF), a new statistical tool in data analysis. This new technique was applied to datasets which refer to different time resolution data. PMF application to atmospheric deposition fluxes identified six main sources affecting the area. The incinerator’s relative contribution seemed to be negligible. PMF analysis was then applied to PM2.5 collected with samplers coupled with a wind select sensor. The higher number of determined environmental indicators allowed to obtain more detailed results on the sources affecting the area. Vehicular traffic revealed the source of greatest concern for the study area. Also in this case, incinerator’s relative contribution seemed to be negligible. Finally, the application of PMF analysis to hourly aerosol data demonstrated that the higher the temporal resolution of the data was, the more the source profiles were close to the real one.
32
Diaz, Poueriet Pablo. « Analysis of Sources Affecting Ambient Particulate Matter in Brownsville, Texas ». Thesis, University of North Texas, 2012. https://digital.library.unt.edu/ark:/67531/metadc115069/.
Texte intégralRésumé :
Texas is the second largest state in U.S.A. based on geographical area, population and the economy. It is home to several large coastal urban areas with major industries and infrastructure supporting the fossil-fuel based energy sector. Most of the major cities on the state have been impacted by significant air pollution events over the past decade. Studies conducted in the southern coastal region of TX have identified long range transport as a major contributor of particulate matter (PM) pollution along with local emissions. Biomass burns, secondary sulfates and diesel emissions sources are comprise as the dominant mass of PM2.5 have been noted to be formed by the long range transport biomass from Central America. Thus, the primary objective of this study was to identify and quantify local as well as regional sources contributing to the PM pollution in the coastal area of Brownsville located along the Gulf of Mexico. Source apportionment techniques such as principal component analysis (PCA) and positive matrix factorization (PMF) were employed on the air quality monitoring data to identify and quantify local and regional sources affecting this coastal region. As a supplement to the PMF and PCA, conditional probability function (CPF) analysis and potential source contribution function (PSCF) analysis were employed to characterize the meteorological influences for PM events. PCA identified an optimal solution of 6 sources affecting the coastal area of Brownsville, while PMF resolved 8 sources for the same area. Biomass comingled with sea salt was identified to be the dominant contributor from the PCA analysis with 30.2% of the apportioned PM mass in Brownsville, meanwhile PMF account secondary sulfates I & II with 27.6%. the other common sources identified included, biomass burning, crustal dust, secondary sulfate, oil combustion, mobile sources and miscellaneous traffic sources.
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Hamman, Jeffrey P. « Theater air apportionment and allocation : application of dynamic algorithms for combat models / ». Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 1995. http://handle.dtic.mil/100.2/ADA306221.
Texte intégral
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Williams, William Benjamin. « Source apportionment and dispersion mapping of fugitive dust using directional passive monitors ». Thesis, University of Portsmouth, 2014. https://researchportal.port.ac.uk/portal/en/theses/source-apportionment-and-dispersion-mapping-of-fugitive-dust-using-directional-passive-monitors(0f3e3b09-c4b9-4e26-b667-7ab2271f7a1e).html.
Texte intégralRésumé :
This study combines passive directional dust monitoring methods with ICP-MS analysis, binary mixing modelling and geostatistical modelling to generate dust dispersion maps, enabling a record of Air Pollution Control residue (APC) dust dispersion on and around a hazardous waste landfill site for a complete calendar year. This is therefore, the first study of nuisance dust dispersion on such a scale, using these methods, and the first time these methods have been used in conjunction to accurately visualise dust dispersion data over time. The proportion of APC in fugitive dust at and around the Wingmoor Farm hazardous waste landfill site near Bishop’s Cleeve, Gloucestershire, UK, was quantified and mapped using passive directional samplers, which were deployed both on the site and in farmland to the north and north-east. Samples from 19 monitors, collected fortnightly over the year, were analysed for Absolute Area Coverage (AAC) and Effective Area Coverage (EAC) prior to HF and HNO3 digestion and analysis by ICP-MS. Following geochemical characterisation of the two key “end-members”, background soils (sand and gravel, and clay) and APC, Ca/Fe and Mn/Pb mixing models were developed providing a means of determining the proportion of APC in each sample. Sample proportions derived from each mixing model were mapped using both variograms and kriging, supported through ISATISTM, to build a model of both general dust and APC dispersion over a square kilometre for the year. Meteorological conditions and movements on site were also recorded and their relationships with dust levels in the surrounding area analysed. APC was found at off-site monitoring locations throughout the year, however at far lower levels than previously assumed by prior modelling exercises. The maps presented a visualisation of dust dispersion on- and off-site, demonstrating the viability of this methodology for modelling both fugitive general dust, and, in this case, APC. In combination with the other data collected on-site, factors affecting the dispersion of both general dust and APC were identified. The development of this modelling and mapping method provides a novel, robust and cost-effective technique for both representing and understanding the dispersion of APC, delivering a useful tool for practical application by industry, local government and in the field of Environmental Forensics.
35
Long, Xuezhu. « Particulate air pollution in central London : characterisation, temporal patterns and source apportionment ». Thesis, University College London (University of London), 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.247431.
Texte intégral
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Tian, Zhe. « Source apportionment of airborne particulate matter in a Chinese megacity : modelling comparison ». Thesis, University of Birmingham, 2018. http://etheses.bham.ac.uk//id/eprint/8201/.
Texte intégralRésumé :
Jinan is one of the most polluted mega-cities in China, which is primarily due to the high levels of PM2.s. A quantitative understanding on the sources of PM2.s is a prerequisite to control the severe pollution. In this project, 103 PM2.s samples were collected and their chemical composition, including water-soluble ions, trace metals, organice carbon, elemental carbon and organice molecular markers, were measured. Mass closure anlysis reveals that OM (29%), sulphate (18%), nitrate (10%), ammonium (9%) and geological material (9%) are the major chemical components in PM2.s in Jinan. The data were fed to both PMF and CMB models for source apportionment and uncertainty analysis. PMF and CMB have identified secondary inorganic aerosol (41%; 31%), coal burning (10%; 16%), biomass burning (20%; 17%), vehicle emission (16%; 14%) and mineral dust (10%; 6%) as the major PM2.s sources in Jinan, respectively. CMB also identified the metallurgic plant (11 %) production as a potentially important source of Jinan's PM2.s. Furtherwork needs to be done including using other source identifications such as back trajectory, chemical transport model and remote sensing. Longer sampling periods is also recommended and establishing the local source profile is vital for the source apportionment in Jinan in the near future.
37
Abood, Ahmed T. « Source Apportionment Analysis of Measured Volatile Organic Compounds in Corpus Christi, Texas ». Thesis, University of North Texas, 2014. https://digital.library.unt.edu/ark:/67531/metadc500059/.
Texte intégralRésumé :
Corpus Christi among of the largest industrialized coastal urban areas in Texas. The strategic location of the city along the Gulf of Mexico allows for many important industries and an international business to be located. The cluster of industries and businesses in the region contribute to the air pollution from emissions that are harmful to the environment and to the people living in and visiting the area. Volatile organic compounds (VOC) constitute an important class of pollutants measured in the area. The automated gas chromatography (Auto GC) data was collected from Texas Commission of Environmental Quality (TCEQ) and source apportionment analysis was conducted on this data to identify key sources of VOC affecting this study region. EPA PMF 3.0 was employed in this sources apportionment study of measured VOC concentration during 2005 - 2012 in Corpus Christi, Texas. The study identified nine optimal factors (Source) that could explain the concentration of VOC at two urbane monitoring sites in the study region. Natural gas was found to be the largest contributor of VOC in the area, followed by gasoline and vehicular exhaust. Diesel was the third highest contributor with emissions from manufacturing and combustion processes. Refineries gases and evaporative fugitive emissions were other major contributors in the area; Flaring operations, solvents, and petrochemicals also impacted the measured VOC in the urban area. It was noted that he measured VOC concentrations were significantly influenced by the economic downturn in the region and this was highlighted in the annual trends of the apportioned VOC.
38
Zanca, Nicola <1985>. « NMR and MASS Spectroscopic Techniques for Source Apportionment of Atmospheric Particulate Matter ». Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2017. http://amsdottorato.unibo.it/8137/1/PhD%20Thesis%20Nicola%20Zanca.pdf.
Texte intégralRésumé :
Aerosols are ubiquitous in the atmosphere, and play a key role in several environmental processes at local and global scale affecting visibility, air quality, and the climate system.
In the present study, proton nuclear magnetic resonance (H-NMR) spectroscopy and aerosol mass spectrometry implemented by an “aerosol chemical speciation monitor” (ACMS) were employed to investigate the chemical composition of submicrometric aerosol collected during a series of intensive field campaigns and to resolve its composition into source-specific fractions including distinct types of primary and secondary organic aerosols (POA and SOA).
During the first study, aerosol samples were collected in the Po Valley, in Bologna (urban site) and San Pietro Capofiume (rural site), during the summer 2012 (PEGASOS project) and fall, winter seasons 2013 (SUPERSITO campaigns). The results show that biomass burning POA and SOA dominate the composition of oxygenated organic aerosols in the Po Valley in the cold season, whereas humic-like substances (HULIS), related to chemically-aged SOA types, are prevalent in the summertime.
In the second part of this thesis work, SOA samples were produced in laboratory using a flow tube reactor designed to simulate prolonged photochemical ageing. The samples were analyzed by H-NMR and high-liquid performance chromatography (HPLC) for the characterization of isoprene, α-pinene and naphthalene SOA products.
The third part of this work was dedicated to two field campaigns at coastal and marine sites in the central Mediterranean region: the first one in Civitavecchia – the port of Rome, for the AIR-SEA Lab project -, and another one onboard the Amerigo Vespucci vessel during the project Dual Use Vespucci. Results showed that PM1 total concentration resulted only 22% lower over the open sea with respect to ports, but the fossil fuel component of OA (the hydrocarbon fraction) was much more enriched in harbors than in off-shore areas.
39
Mishra, Nitika. « Characterisation, toxicity and source apportionment of atmospheric organic pollutants in urban schools ». Thesis, Queensland University of Technology, 2015. https://eprints.qut.edu.au/90055/12/90055%28thesis%29.pdf.
Texte intégralRésumé :
Airborne organic pollutants have significant impacts on health; however their sources, atmospheric characteristics and resulting human exposures are poorly understood. This research characterized chemical composition of atmospheric volatile organic compounds, polycyclic aromatic hydrocarbons and carbonyls in representative number of primary schools in Brisbane Metropolitan Area, quantified their concentrations, assessed their toxicity and apportioned them to their sources. The findings expand scientific knowledge of these pollutants, and will contribute towards science based management of risks associated with pollution emissions and air quality in schools and other urban and indoor environments.
40
Khan, Md Badiuzzaman <1979>. « Inorganic and organic pollutants in atmospheric aerosols : chemical composition and source apportionment ». Doctoral thesis, Università Ca' Foscari Venezia, 2015. http://hdl.handle.net/10579/8350.
Texte intégralRésumé :
This work is the first one conducted in Veneto region, Italy with collaboration of ARPAV including important organic (OC/EC and PAHs) and inorganic pollutants (trace elements), which were characterized for longer period of time in order to quantify the source contributions of PM2.5 at regional scale (Veneto) using receptor modelling [Factor Analysis]. 360 samples were collected from six major cities located in 6 Provinces during April 2012- February 2013. The results show that OC, EC, PAHs and Trace elements exhibited higher concentration during winter month in all measurement sites, suggesting that the stable atmosphere and lower mixing layer play important role for the accumulation of pollutant. Meteorological parameters especially wind velocity and temperature play significant role in pollutant accumulation from local sources. Finally, possible sources of particulate matter have been characterized using Conditional Bivariate Probability Function, diagnostic ratios and Factor Analysis and results indicated that biomass burning for household heating and cooking, followed by vehicular traffic, oil combustion and crustal are the main sources of particulate matter in Veneto region.
41
Grimbeek, Mathew. « The applicability of the apportionment of Damages Act 34 of 1956 to contractual claims with emphasis on the development of apportionment laws in South Africa and similar foreign jurisdictions ». Diss., University of Pretoria, 2012. http://hdl.handle.net/2263/26669.
Texte intégralRésumé :
This study will follow the development of the rules pertaining to apportionment of damages, with particular emphasis on the Apportionment of Damages Act 34 of 1956 (‘the Act”) and its applicability to contractual claims. It furthermore delves into the current legal position in England, Australia and New Zealand. In Thoroughbred Breeders Association v Price Waterhouse 1999 (4) SA 968 (W), the Court decided that the Act was applicable to contractual claims and apportioned the damages payable by the defendant to the plaintiff. However, the matter was taken on appeal with the decision of the Court a Quo overturned. It will be argued that, although the reasoning at first glance seems sound, upon closer examination, the application of the Act need not be limited solely to delictual claims. The best manner in which to remedy this lacunae in our law is an amendment to Section 1 (1) and 1(3) of the Act, to explicitly extend the application thereof to contractual claims.Dissertation (LLM)--University of Pretoria, 2012.
Private Law
unrestricted
42
Petutschnig, Matthias. « Common consolidated corporate tax base. Effects of formulary apportionment on corporate group entities ». SFB International Tax Coordination, WU Vienna University of Economics and Business, 2010. http://epub.wu.ac.at/428/1/document.pdf.
Texte intégralRésumé :
The European Commission is currently working on a legislative draft to harmonise the corporate income tax provisions for multinational groups of companies throughout the European Union. For that purpose the European Commission has installed a working group with the mission to draft a Common Consolidated Corporate Tax Base (CCCTB) applicable for multinational companies. As the EU member states are not willing to surrender their taxing power to the supranational level of the EU each group entity's tax base would be determined by apportionment of the group's overall taxable income according to a predefined micro-economic factor based formula whereas the group income will be calculated by consolidating earnings beforehand separately determined by each group entity (preconsolidation income). The situs state of the particular group entity would then apply its statutory corporate tax rate on the apportioned tax base. This paper evaluates the effects of this prospective apportionment procedure on any given corporate group entity and finds that the share of the group's income allocated to a particular entity using the apportionment formula does regularly not equal the pre-consolidation income of the respective group entity. The reasons for this regular observable deviation can be found on the one hand in the concept of the apportionment formula and on the other hand in the specifics of the definitions of the apportionment factors. (author's abstract)Series: Discussion Papers SFB International Tax Coordination
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Ortmann, Regina, et Erich Pummerer. « Formula Apportionment or Separate Accounting ? Tax-Induced Distortions of Multinationals' Location Investment Decisions ». WU Vienna University of Economics and Business, Universität Wien, 2015. http://epub.wu.ac.at/4703/1/SSRN%2Did2688090.pdf.
Texte intégralRésumé :
We examine which tax allocation system leads to more severe distortions with respect to locational
investment decisions. We consider separate accounting (SA) and formula apportionment (FA). The
effects of both systems have been hotly debated in Europe in the past years. The reason is that the EU
Member States are striving to implement a common European tax system that would lead to a switch
from SA to FA. While existing studies focus primarily on the impact of taxes on locational decisions
under either SA or FA, the main innovation of this paper is that it compares both systems with regard
to the level of distortions they induce. We compare the optimal pre-tax investment decision with the
optimal after-tax investment decision and infer from the difference in the allocation of investment
funds which tax allocation system causes more severe distortions. We assume that the multinational
group (MNG) has comprehensive book income shifting opportunities under SA. We find that the
investment incentives under SA are opposed to those under FA for a profitable investment project.
Whereas under SA as much as possible should be invested in a high-tax country, under FA as much as
possible should be invested in a low-tax country. The distortions of locational investment decisions
tend to be more severe under SA than under FA if a greater share of investment funds is to be invested
in a low-tax country from a pre-tax perspective and the investment is profitable. Vice versa, locational
decisions may be more distorted under FA if the optimal pre-tax investment decision requires
investing a major share of funds in the high-tax country. In contrast to the often stated insensitivity of
FA towards income shifting, we find the introduction of a tax allocation system based on FA in
Europe could lead to a severe shift of economic substance to low-tax countries. The results of this
paper are of particular interest for European policy makers and MNGs as our findings may induce
European MNGs to reassess their recent locational investment decisions in the face of a potential
future change in the applied tax allocation system. (authors' abstract)Series: WU International Taxation Research Paper Series
44
Zhou, Jinpeng. « Chemical characterisation and source apportionment study of PM10 in the atmosphere of London ». Thesis, King's College London (University of London), 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.267484.
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Hafner, William D. « Source apportionment and atmospheric transport of persistent organic pollutants near the Great Lakes ». [Bloomington, Ind.] : Indiana University, 2005. http://wwwlib.umi.com/dissertations/fullcit/3162972.
Texte intégralRésumé :
Thesis (Ph.D.)--Indiana University, School of Public Environmental Affairs, 2005.Title from PDF t.p. (viewed Dec. 2, 2008). Source: Dissertation Abstracts International, Volume: 66-02, Section: B, page: 0785. Chair: Ronald A. Hites.
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Estep, Robert Noah. « Examination of the application and limitations of structural mode extraction via force apportionment ». Thesis, This resource online, 1996. http://scholar.lib.vt.edu/theses/available/etd-02132009-172353/.
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Hettiyadura, Anusha Priyadarshani Silva. « Quantification of organosulfates and their application in source apportionment of atmospheric organic aerosols ». Diss., University of Iowa, 2018. https://ir.uiowa.edu/etd/6132.
Texte intégralRésumé :
Organic aerosol is a major constituent of atmospheric fine particulates (PM2.5), which adversely affect human health and change the Earth’s radiative energy balance. Primary organic aerosol is directly emitted from sources and secondary organic aerosol (SOA) is formed in the atmosphere following oxidation of volatile organic compounds (VOC) from anthropogenic and biogenic sources. Biogenic SOA is enhanced by anthropogenic pollutants such as sulfate and NOx that mainly come from fossil fuel combustion. However, the extent to which the anthropogenic pollutants enhance biogenic SOA in different environments is unknown. The central hypothesis of this thesis is that organosulfates, organic compounds containing a sulfate ester group, are useful as tracers for anthropogenically-influenced biogenic SOA. This research aims to provide a better understanding of the sources of PM2.5 organic carbon (OC), particularly secondary organic carbon (SOC), through the inclusion of organosulfates in an organic tracer-based source apportionment model. The specific objectives of this research include 1) development of a highly sensitive and accurate method to quantify highly polar organosulfates in atmospheric aerosols, 2) identification and quantification of major organosulfate species in the ambient air, and 3) determination of anthropogenic and biogenic sources and their contributions to PM2.5 OC using an organic tracer-based positive matrix factorization (PMF) model.
A highly sensitive and accurate method was developed and validated for the quantification of highly polar organosulfates using hydrophilic interaction liquid chromatography (HILIC) and tandem mass spectrometry (MS/MS). The developed method shows excellent retention of carboxylic acid and hydroxyl containing organosulfates. The HILIC-MS/MS method was applied to PM2.5 samples collected in summer 2013 at a rural site in Centreville, AL. Quantified organosulfates accounted for approximately 0.3% of PM2.5 OC. Other major organosulfates, for which standards are not available, were monitored by their fragmentation to the bisulfate anion and/ or sulfate ion radical. The major organosulfates were determined to be 2-methyltetrol sulfate and other isoprene-derived organosulfates. Eight sources of the PM2.5 OC in Centreville, AL were identified using PMF model through the application of organosulfates and commonly used organic tracers measured in samples collected during the daytime and nighttime: vehicle emissions (8%), prescribed burning (11%), isoprene SOC formed under low-NOx (13%) and high-NOx conditions (11%), SOC formed by photochemical reactions (9%), oxidatively aged biogenic SOC (6%), sulfuric acid-influenced SOC (21%), and monoterpene SOC formed under high-NOx conditions (21%). The organosulfates enabled organic tracer-based PMF to resolve sulfuric acid-influenced SOC, while the daytime and nighttime measurements enabled organic tracer-based PMF to resolve SOC formation pathways with diurnal variations (e.g. SOC formed by photochemical reactions). The PM2.5 OC in Centreville was mainly secondary in origin (81%) and was influenced by NOx, ozone (a product of photochemical reactions of NOx and VOC), and sulfuric acid. Together, primary and secondary OC influenced by the fossil fuel use was 76%. Thus, the majority of the PM2.5 OC in Centreville during summer can be controlled by the reduction of fossil fuel use.
The HILIC-MS/MS method was also applied to daily PM2.5 samples collected from an urban site in Atlanta, GA during August 2015. The major organosulfate species identified in Atlanta were dominated by 2-methyltetrol sulfate and other isoprene-derived organosulfates, similar to Centreville. They contributed 16% of PM2.5 OC and accounted for the majority of the isoprene-derived SOA that had not previously been identified at the molecular level. The concentrations of the major isoprene-derived organosulfates in Atlanta were two to six times higher than in Centreville. The greatest enhancement was obtained for 2-methylglyceric acid sulfate, a known isoprene SOA tracer formed under high-NOx conditions, reflecting the 15 times higher average NOx concentration in Atlanta during August 2015 compared to Centreville in summer 2013. These results indicate that NOx had a stronger influence on isoprene-derived organosulfate formation in urban Atlanta compared to rural Centreville.
Overall, these results indicate that organosulfates are useful tracers for anthropogenically-influenced biogenic SOA. Thus, it is important to quantify them for use in organic tracer-based PMF modeling to determine the anthropogenically-influenced biogenic SOC in PM2.5 OC.
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George, K. V. « Source apportionment of particulate matter pollution around a pit head thermal power station ». Thesis, IIT Delhi, 2016. http://localhost:8080/iit/handle/2074/7042.
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Nelson, Ludwig W. « Value-Added Tax apportionment methodology applied in the higher sector of South Africa : Is the apportionment method currently applied in the higher education sector effective and appropriate in a South African context ? » Master's thesis, University of Cape Town, 2016. http://hdl.handle.net/11427/20975.
Texte intégralRésumé :
This dissertation focusses on the value-added tax apportionment methodology applied in the higher education sector of South Africa. The current apportionment method applied by universities is the varied input-based method. The research question that is posed, is whether the varied input-based method is effective and appropriate in the higher education sector in a South African context and whether or not there are other solutions which could apply to alleviate the burden that apportionment has placed on the universities. In addressing the research question the dissertation specifically discusses the principles of apportionment, turnover-based method, input-based method and varied input-based method. Furthermore, the dynamics of the higher education sector is discussed in detail with specific focus on the income streams and expense types of universities and how this influences the application of apportionment methods. Lastly, other solutions are considered such as a reduced Value-Added Tax rate for the supply of educational services and the zero-rating of the supply of educational services. It is concluded that the varied input-based method is definitely not the long term solution as the difficulty in its application and the financial burden makes it impracticable to use. Also, it is concluded that a possible solution is to zero-rate the supply of educational services by universities in terms of section 11 of the Value-Added Tax Act No. 89 of 1991. This would not only alleviate the burden of apportionment, but also result in universities being allowed to claim all the VAT it incurs (except for input tax denied in terms of section 17(2) of the Value- Added Tax Act No. 89 of 1991) and result in a net gain for the universities. Whatever is decided, the current investigation of apportionment methodology applied in the higher education sector of South Africa needs to be concluded as soon as possible and a clear practical and sustainable approach needs to be agreed upon, as it is in the best interest of all of the parties involved as well as South Africa and the education of its people as a whole.
50
Toner, Stephen Mark. « Anthropogenic particulate source characterization and source apportionment using aerosol time-of-flight mass spectrometry ». Connect to a 24 p. preview or request complete full text in PDF format. Access restricted to UC campuses, 2007. http://wwwlib.umi.com/cr/ucsd/fullcit?p3283574.
Texte intégralRésumé :
Thesis (Ph. D.)--University of California, San Diego, 2007.Title from first page of PDF file (viewed November 21, 2007). Available via ProQuest Digital Dissertations. Vita. Includes bibliographical references.