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Stoecker, Matthew A. "Biodegradation of aromatic and aliphatic hydrocarbons by Rhodococcus spp. /." Thesis, Connect to this title online; UW restricted, 1998. http://hdl.handle.net/1773/11495.
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Kondaveeti, Rajiv. "Impact of Halogenated Aliphatic and Aromatic Additives on Soot and Polycyclic Aromatic Hydrocarbons -- An Ethylene-air Laminar Co-flow Diffusion Flame Study." University of Dayton / OhioLINK, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=dayton1343786258.
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Becker, Jonathan [Verfasser]. "Synthetic and kinetic investigations on selective oxidation of aromatic and aliphatic hydrocarbons with copper complexes / Jonathan Becker." Gießen : Universitätsbibliothek, 2015. http://d-nb.info/1073119173/34.
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Magoha, Happy Steven. "Destruction of polycyclic aromatic hydrocarbons (PAH's) and aliphatic hydrocarbons in soil using ball milling thesis submitted in (partial) fulfilment of the Master of Applied Science, Auckland University of Technology, May 2004." Full thesis. Abstract, 2004. http://puka2.aut.ac.nz/ait/theses/MagohaH.pdf.
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Tanwar, Shivalika. "Investigation of encapsulation of Aromatic polluants by β-Cyclodextrin in presence of linear aliphatic alcohols." Thesis, Sorbonne Paris Cité, 2018. http://www.theses.fr/2018USPCD076.
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La pollution de l’environnement par les composés organiques est devenue une préoccupation mondiale majeure. Les molécules aromatiques comme les cycles benzéniques et leurs dérivés ont attiré une attention considérable en raison de la toxicité reconnue et de la cancérogénicité. Principalement utilisées en chimie supramoléculaire,les cyclodextrines sont des structures moléculaires en forme de cône tronqué ayant une surface externe hydrophile et une cavité hydrophobe. Ainsi, ils peuvent théoriquement encapsuler un grand nombre de molécules organiques hydrophobes pour former des complexes d'inclusion solubles dans l'eau. Cette propriété de complexation a une application potentielle dans le domaine de la détection et de la quantification des polluants polycycliques aromatiques dans les eaux environnementales par des moyens spectroscopiques portables. Nous souhaitons comprendre ce phénomène d’inclusion en combinant des approches théoriques et expérimentales appliquées à l’état solide et en solution. Il a été observé que seules quelques structures cristallines de complexes de cyclodextrines, molécules aromatiques pures, apparaissent dans les bases de données structurelles après un court examen. L'objectif principal de nos recherches est donc de nous concentrer plus précisément sur les interactions entre les alcools aliphatiques et les molécules de cyclodextrine. Pour cela,afin de corréler nos études expérimentales et théoriques, les résultats obtenus ont été suivis de manière systématique par différentes techniques spectroscopiques afin d'observer l'interaction entre les molécules. De plus, les poudres et les cristaux obtenus en faisant varier la solubilité des mélanges ont été soumis à une analyse physico-chimique, à une diffraction des rayons X et à une surveillance DSC pour étayer nos résultats. Ce travail comprend également la modélisation de complexes d'inclusion en utilisant différentes approches, comme la combinaison de méthodes semi-empiriques de la chimie quantique (DFT / TD-DFT) et de la mécanique moléculaire polarisable. Des calculs ont été effectués sur des clusters internes, ce qui permettra de mettre en évidence des facteurs structurels et énergétiques de complexationEnvironmental water pollution by organic compound has become a major worldwide concern. Aromatic molecules like benzene rings and their derivatives have gained considerable attention due to officially documented toxicity and carcinogenicity. Mostly used in supramolecular chemistry, Cyclodextrins are truncated cone-shaped molecular structures having a hydrophilic outer surface and a hydrophobic cavity. Thus, they can theoretically encapsulate a large number of hydrophobic organic molecules to form water-soluble inclusion complexes. This complexation property has potential application in the field of detection and quantification of aromatic polycyclic pollutants in environmental water by portable spectroscopic means. We are interested in understanding this phenomenon of inclusion by combining theoretical and experimental approaches applied to solid state and in solution. It has been observed that only a few crystalline structures of cyclodextrin- pure aromatic molecule complexes appear in the structural databases after a brief review. Therefore, the main objective of our research is to focus more precisely on the interactions between the aliphatic alcohols and cyclodextrin molecules. For this purpose, to correlate our experimental and theoretical studies, the results obtained were monitored by various spectroscopic techniques in a systematic manner to observe the interaction between the molecules. Moreover, the powders and crystals obtained by varying the solubility of the mixtures were further subjected to physico-chemical analysis, X-ray diffraction, and DSC monitoring to support our findings. This work also includes modeling of inclusion complexes using different approaches like combining semi-empirical methods of quantum chemistry (DFT / TD-DFT) and polarizable molecular mechanics. Calculations were carried out on homemade clusters, which will allow the implementation of evidence of structural and energetic factors for complexation
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Deshmukh, Ashish Pramod. "Sorption and sequestration of phenanthrene In polymethylenic plant biopolymers: proxies for soil and sedimentary rrganic matter." The Ohio State University, 2003. http://rave.ohiolink.edu/etdc/view?acc_num=osu1054564060.
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Lopes, Alcinei Pereira. "Estudo de hidrocarbonetos e metais em sedimentos de fundo do Rio Negro na orla urbana de Manaus." Universidade Federal do Amazonas, 2010. http://tede.ufam.edu.br/handle/tede/3329.
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The waters of the Rio Negro, in the border city of Manaus, receives large amounts of domestic and industrial waste from its main tributaries (Tarumã-Acu, Sao Raimundo, Pupils and Puraquequara) that may be compromising their natural features (water, plants, sediments and etc.). Due the ability to accumulate organic and inorganic compounds, the bottom sediments are used to assess the contamination levels of aquatic environments. As a result, we determined the concentrations of aliphatic hydrocarbons, polycyclic aromatic hydrocarbons (PAH) and potentially toxic metals (MPT) in ten samples of bottom sediments collected in March 2009 in the confluence between the Rio Negro and major watersheds the city of Manaus. The aim of study was to classify the origin and level of contamination of these compounds. In the determination of hydrocarbons, sediments were freeze dried, extracted with hexane, fractionated by open column liquid chromatography. The determination of aliphatic hydrocarbons was performed by GC-FID and the PAH by GC-MS. After digestion with aqua regia the MPT (Al, Fe, Zn, Cu, Ni, Cr, Pb, Cd and Mn) in total fraction of sediments were determined by ICP-OES. The results showed that concentrations of total aliphatic hydrocarbons were 13.4 to 448 mg g-1, and the sum of 38 PAHs was 58.8 to 6832 ng g-1. These values are considered high for natural aquatic environments that have not suffered oil spill accidents. Among the metals determined Al (32 091 mg kg-1) and Fe (35 474 mg kg-1) were those with the highest concentrations.The sediments that received the largest anthropogenic contribution were those collected at the entrance of the basin of the streams São Raimundo and Educandos. The diagnosis index hydrocarbons the origin of in sediments showed a predominance of mixed sources and petrogenic sources in most seasons
As águas do rio Negro na orla urbana de Manaus recebem grande quantidade de resíduos domésticos e industriais de seus principais afluentes (Tarumã-Açu, São Raimundo, Educandos e Puraquequara) que podem estar comprometendo suas características naturais (água, plantas, sedimentos e etc). Por ter a capacidade de acumular compostos orgânicos e inorgânicos, os sedimentos de fundo são utilizados na avaliação dos níveis de contaminação de ambientes aquáticos. Em virtude disso, foram determinados as concentrações de hidrocarbonetos alifáticos, hidrocarbonetos policíclicos aromáticos (HPA) e metais em dez amostras de sedimentos de fundo, coletadas em março de 2009 nas confluências entre o rio Negro e as principais bacias de drenagem da cidade de Manaus. O estudo tem o objetivo de classificar a origem e o nível de contaminação destes compostos. Nas determinações de hidrocarbonetos, os sedimentos foram liofilizados, extraídos em soxhlet, fracionados por cromatografia líquida de coluna aberta. A determinação de hidrocarbonetos alifáticos foi realizada por CG-DIC e os HPA por CG-EM. Apos digestão com água régia, os metais (Al, Fe, Zn, Cu, Ni, Cr, Pb, V, Cd e Mn) presentes na fração total dos sedimentos foram determinados por ICP-OES. Os resultados mostraram que as concentrações dos hidrocarbonetos alifáticos totais foram de 13,4 a 448 μg g-1, e a somatória dos 38 HPA foi de 58,8 a 6832 ng g-1. Esses valores são considerados elevados para ambientes aquáticos naturais que não sofreram acidentes de derrame de óleo. Entre os metais determinados o Al (32091 mg kg-1) e o Fe (35474 mg kg-1) foram os que apresentaram as maiores concentrações. Os sedimentos que receberam a maior contribuição antrópica foram daqueles coletados na entrada da bacia dos igarapés São Raimundo e Educando. Os índices de diagnósticos da origem de ix hidrocarbonetos nos sedimentos mostraram predominância de fontes petrogênica e fontes mistas na maioria das estações.
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Gualandi, Giovanni <1973>. "Chlorinated aliphatic and aromatic hydrocarbons biodegradation: bioaugmentation tests in slurry microcosmos and study of the catabolic potential of microbial community in the interface between groundwater and surface water." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2007. http://amsdottorato.unibo.it/382/.
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CRAVEIRO, Nykon. "Hidrocarbonetos no sedimento superficial do sistema estuarino do Rio Formoso, nordeste do Brasil." Universidade Federal de Pernambuco, 2016. https://repositorio.ufpe.br/handle/123456789/18335.
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CNPq
A contaminação por hidrocarbonetos (HCs) do petróleo em regiões costeiras marinhas, como os estuários, é considerada uma das mais importantes e impactantes, devido aos danos que esses elementos podem ocasionar aos organismos e ao homem. O objetivo do presente estudo foi investigas, pela primeira vez, os hidrocarbonetos nos sedimentos superficiais do sistema estuarino do Rio Formoso (SERF), litoral Sul do estado de Pernambuco – Brasil. Os compostos de hidrocarbonetos alifáticos (HAs) foram determinados em cromatógrafo a gás (GC) Agilent Tecnologies 7820A, acoplado a um detector de ionização de chamas (DIC) e os compostos de hidrocarbonetos policíclicos aromáticos (HPAs) foram determinados no mesmo cromatógrafo, porém acoplado a um espectrômetro de massas 5975 (MS) em modo de monitoramento de íons selecionados (SIM). A concentração de alifáticos totais (∑Alif) nos sedimentos do SERF variou entre 1,37 e 126,64 μg g-1 peso seco (ps), com as concentrações de n-alcanos totais (Σn-Alc) entre 0,51 e 27,5 μg g-1 ps, oriundos principalmente de fontes biogênicas, como vegetais superiores. A concentração de HPAs (Σ16HPAs) variou entre 3,80 e 500,3 ng g-1 ps, provenientes de fontes petrogências e pirogênicas As concentrações de hidrocarbonetos alifáticos e aromáticos detectados nos sedimentos do sistema estuarino do Rio Formoso foram consideradas baixas, quando comparadas com outras áreas estudadas ao redor do mundo e aos índices propostos por estudos e agências reguladoras nacionais e internacionais, sugerindo um ambiente com pouco impacto sobre a biota. Contudo, a presença de compostos como HPAs é um indicativo de ação antrópica sobre o sistema, sendo importante a implantação e manutenção de um programa de monitoramento na área, quanto aos hidrocarbonetos, para avaliar os possíveis impactos que a presença desses compostos possam ocasionar sobre o SERF e garantir a conservação continuada de um estuário de tamanha importância ecológica, econômica e social.
The contamination by hydrocarbons (HCs) of oil in marine coastal regions, such as estuaries, is considered one of the most important and impactful due to the damage that these elements may cause to the bodies and man. The aim of this study was investigas for the first time, the hydrocarbons in the surface sediments of the estuarine system of the Formoso river (SERF), South coast of the state of Pernambuco - Brazil. Aliphatic hydrocarbon compounds (HAs) were determined on a gas chromatograph (GC) Agilent Technologies 7820A coupled to a flame ionization detector (FID) and polycyclic aromatic hydrocarbon compounds (PAH) were determined in the same chromatograph, however coupled a mass spectrometer 5975 (MS) in selected ion monitoring mode (SIM). The concentration of total aliphatic (ΣAlif) in SERF sediments ranged between 1.37 and 126.64 μg g-1 dry weight (dw), with total n-alkanes concentrations (Σn-Alc) between 0.51 and 27.5 μg g-1 dw, mainly from biogenic sources such as higher plants. The concentration of PAHs (Σ16HPAs) ranged from 3.80 to 500.3 ng g-1 dw, from petrogências sources and pyrogenic Hydrocarbon concentrations aliphatic and aromatic detected in the sediments of the estuarine system of the Formoso river were considered low compared with other areas studied around the world and the indices proposed by studies and national and international regulatory agencies, suggesting an environment with little impact on the biota. However, the presence of compounds such as PAHs is indicative of human action on the system, it is important to establishing and maintaining a monitoring program in the area, as hydrocarbons, to assess the possible impact that the presence of these compounds can cause on SERF and ensure the continued conservation of an estuary of such ecological, economic and social.
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Tian, Zhenjiao. "Oxidation and Reduction Process for Polycyclic Aromatic Hydrocarbons and Nitrated Polycyclic Aromatic Hydrocarbons." The Ohio State University, 2008. http://rave.ohiolink.edu/etdc/view?acc_num=osu1228333650.
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Bastow, Trevor. "Sedimentary Processes Involving Aromatic Hydrocarbons." Curtin University of Technology, School of Applied Chemistry, 1998. http://espace.library.curtin.edu.au:80/R/?func=dbin-jump-full&object_id=9379.
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Sedimentary organic matter contains many compounds that have no obvious biogenic precursors, so their formation and occurrence are of geochemical interest. The first part of this thesis (chapters 2-5) discusses the results obtained from studying hydrocarbon racemates. Some of the compounds identified are also suggested as intermediates in the formation of alkylnaphthalenes identified in chapters 6-7. The second part of this thesis (chapters 6-11) covers the identification of a range of alkylnaphthalenes and alkylphenanthrenes in sedimentary organic matter. Possible pathways for the formation of these hydrocarbons are outlined and their application as probes into the processes of petroleum formation are described.In chapter 2 the use of permethylated cyclodextrin capillary gas chromatography columns to separate hydrocarbon racemates are reported. Chapter 3 reports the synthesis of 1,2,2,5-tetramethyltetralin and 1,2,2,5,6-pentamethyltetralin and identifies them as racemates in crude oil. They are proposed as intermediates in the formation of sedimentary alkylnaphthalenes (identified in chapters 6 and 7).The identification of isodihydro-ar-curcumene in sedimentary organic matter is described in chapters 4 and 5. It co-occurs in crude oil with dihydro-ar-curcumene and is suggested to originate from this compound via a sedimentary rearrangement process. Chiral GC-MS techniques have been used to show the presence of both enantiomers of these compounds in crude oils. The elution order of the enantiomers has been established using reference compounds of known configuration. The effects of maturity and biodegradation on dihydro-ar-curcumene and isodihydro-ar-curcumene enantiomers is reported. Optically pure dihydro-ar-curcumene from natural products undergoes rapid racemisation in the subsurface, yielding a racemic mixture before the onset of significant oil formation. ++1,2-Alkyl shifts on the aromatic ring also begin at an early stage to yield isodihydro-ar-curcumene and these processes continue with increasing maturity. Laboratory experiments using proton and clay catalysts (Lewis acid catalyst) show that the alkyl shift reaction is catalysed by both proton and Lewis acids, and racemisation is only catalysed by Lewis acids. A moderately biodegraded crude oil has been shown to be depleted in the R enantiomer of dihydro-ar-curcumene and an extensively degraded oil has dihydro-ar-curcumene depleted relative to isodihydro-ar-curcumene.The identification of a number alkylnaphthalenes and their possible origins in sedimentary organic matter is described in chapters 6 and 7. In chapter 6 a previously unreported tetramethylnaphthalene (TeMN) was identified in petroleum. This compound is structurally similar to bicyclic compounds of microbial origin and these are suggested as a likely source, via a tetralin intermediate identified in chapter 3. In chapter 7 isomeric pentamethylnaphthalenes previously unreported in sedimentary organic matter are reported. These isomeric pentamethylnaphthalenes (PMNs) were identified in a number of crude oils and sediments, ranging in age from Proterozoic to Tertiary. 1,2,3,5,6-PMN is suggested to form predominantly from the aromatisation of drimanoid precursors via 1,2,2,5,6-pentamethyltetralin identified in chapter 3. In laboratory experiments, the other pentamethylnaphthalenes were generated from 1,2,3,5,6-PMN in proportions that reflect the relative stability of the isomers. By analogy, the other PMNs in sediments are suggested to arise via acid catalysed isomerisation or transalkylation processes. A maturity parameter was developed based on laboratory experiments in conjunction with observed distributions of pentamethylnaphthalenes.The formation of alkylnaphthalenes and alkylphenanthrenes through a ++
methylation process is discussed in chapters 8-10. Several crude oils and shales which contain anomalously high concentrations of 1,6-dimethylnaphthalene, 1,2,5-trimethylnaphthalene, 1,2,7-trimethylnaphthalene, 1,2,3,5-tetramethylnaphthalene, 1,2,3,5,6-pentamethylnaphthalene, 2-methyl-6-isopropyl-1(4-methylpentyl)naphthalene, phenanthrene, 1-methylphenanthrene, 1,7-dimethylphenanthrene and retene have been shown to contain relatively high concentrations of their corresponding methylated counterparts. In laboratory experiments carried out under mild conditions, each of the alkylnaphthalenes and alkylphenanthrenes have been shown to be methylated in specific positions when heated with a methyl donor in the presence of a clay catalyst. These observations have been interpreted as evidence for a sedimentary methylation process.The effect of biodegradation on alkylnaphthalenes and alkylphenanthrenes formed from sedimentary methylation is described in chapter 11. Land-plant-derived aromatic hydrocarbons with a range of susceptibilities to reservoir biodegradation have been identified in crude oils. These compounds are the result of reactions of natural products involving aromatisation, rearrangement and methylation in the sediments (chapters 9 and 10). They are therefore suggested as markers for land-plants in severely biodegraded oils in which most of the other biologically derived compounds cannot be recognised. The order of biodegradability of these compounds has been assessed relative to their non-methylated counterparts namely 6-isopropyl-2-methyl-1-(4-methylpentyl)naphthalene and retene. The order of degradation of the four compounds is : retene < 9-methylretene ~ 6-isopropyl-2-methyl-1-(4-methylpentyl)naphthalene > 6-isopropyl-2,4-dimethyl-1-(4-methylpentyl)naphthalene. These results have been used to assess that a crude oil is a mixture of severely biodegraded and ++
less biodegraded crude oil.
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Crowley, Colin. "Fullerenes from polycyclic aromatic hydrocarbons." Thesis, University of Sussex, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.360582.
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Olariu, Romeo Iulian. "Atmospheric oxidation of selected aromatic hydrocarbons." [S.l.] : [s.n.], 2001. http://deposit.ddb.de/cgi-bin/dokserv?idn=964170299.
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Safinowski, Michael. "Anaerobic biodegradation of polycyclic aromatic hydrocarbons." kostenfrei, 2005. http://deposit.ddb.de/cgi-bin/dokserv?idn=97648627X.
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Robertson, Charles Ray. "Chemistry towards curved polycyclic aromatic hydrocarbons." abstract and full text PDF (free order & download UNR users only), 2006. 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:1438911.
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Wanene, Wilson Kamau. "Toward curved polycyclic aromatic hydrocarbons (PAHs)." abstract and full text PDF (free order & download UNR users only), 2007. 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:1445914.
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Gleisner, Florian Hans. "Bacterial degradation of polycyclic aromatic hydrocarbons." Thesis, University of York, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.247752.
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Peters, Andrew John. "Polycyclic aromatic hydrocarbons in seasonal snowcover." Thesis, University of Southampton, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.315520.
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Sritongkam, Pornpimol. "Electrochemical measurement of polycyclic aromatic hydrocarbons." Thesis, Cranfield University, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.274039.
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Kapinus, Vadym A. Beauchamp Jesse L. "Photophysical properties of protonated aromatic hydrocarbons /." Diss., Pasadena, Calif. : California Institute of Technology, 2005. http://resolver.caltech.edu/CaltechETD:etd-01252005-123917.
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Nowicka, Ewa. "Selective oxidation of polynuclear aromatic hydrocarbons." Thesis, Cardiff University, 2012. http://orca.cf.ac.uk/40092/.
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This thesis targets the selective oxidation of polynuclear aromatic compounds, which is considered as a preliminary step of upgrading of heavy oils, resids and bitumens to higher value materials in the liquid phase using different catalytic systems. Oxidation studies concentrated on simple model polyaromatic compounds and their alkylated derivatives. Ruthenium ion catalyzed oxidation chemistry has the potential to selectively oxidize PAHs and this system was studied in great detail with particular attention made to the reaction solvent system. Through careful studies it was found that the use of a monophasic solvent system led to the selective oxidative opening of an aromatic ring to produce the dialdehyde derivative. It was demonstrated that under standard conditions the rate of oxidation increased with the size of the fused ring system. 1H NMR methodology was developed to quantify the percentage of alkyl chain hydrogens preserved after reaction. It was found that the ruthenium based system demonstrated a high affinity for the oxidation of aromatic carbon with a low tendency to oxidise aliphatic carbon. These studies formed the basis of a detailed investigation into the mechanism of ruthenium ion catalyzed oxidation of PAHs. Investigation into another catalytic system which uses a homogeneous tungsten catalyst with hydrogen peroxide as the oxidant was also performed. Early studies showed that the H2WO4/H2O2 catalytic system exhibits high solvent dependant selectivity towards preferential oxidation of aromatic carbon. What is more, studies using alkylated aromatics with a alkyl chain greater than C8 showed that even in a non polar solvent the selectivity of oxidation is directed towards the aromatic carbon. A range of catalytic systems containing tungsten, ruthenium, heteropolyacids and their heterogenised equivalents were also applied to the oxidation of PAHs. Au-Pd supported catalysts in combination with molecular oxygen and H2WO4 were also used for the oxidation of PAHs and the results obtained opened a new path in the research of PAHs. Studies on the oxidative desulfurization, denitrogenation of heteroaromatics and the demetallation of nickel and vanadium porphyrines was also performed and are reported in this thesis.
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Ouellette, Mélanie. "Gas-phase Ion Chemistry of Hydroxy and Amino-substituted Interstellar Polycyclic Aromatic Hydrocarbons and Protonated Polycyclic Aromatic Hydrocarbons." Thesis, Université d'Ottawa / University of Ottawa, 2014. http://hdl.handle.net/10393/31349.
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The gas-phase ion chemistry of hydroxyl- and amino-substituted polycyclic aromatic hydrocarbons (PAHs) and their protonated counterparts were studied using mass spectrometry. Ions were generated using an electron ionization (EI) source and the unimolecular chemistry of metastable ions was studied by performing mass-analysed ion kinetic energy spectrometry (MIKES) experiments with a magnetic sector tandem mass spectrometer. Collision-induced dissociation (CID) experiments were used in conjunction with MIKES experiments to determine ion structure. The ten molecules studied were: 1-naphthol, 2-naphthol, 1-naphthylamine, 2-naphthylamine, 1-aminoanthracene, 2-aminoanthracene, 1-phenanthrol, 9-phenanthrol, 1-hydroxypyrene and 1-aminopyrene. Since it is believed that larger PAHs, on the order of more than 50 carbon atoms, populate the interstellar medium, the goal of this study was to attempt to extrapolate the results from smaller systems to larger ones. The trends found include: hydroxy-substituted PAH radical cations lose carbon monoxide spontaneously and amino-substituted PAH radical cations lose HCN. Mechanisms for both processes are proposed, and it appears from the present results that this process should extrapolate to larger PAHs. Another trend found was that all the remaining fragment ions were always a closed ring. Protonated amino-substituted PAHs were generated by electrospray ionization using a quadruple time-of-flight mass spectrometer. By protonating 1-naphthol and 2-naphthol using methane in the high-pressure EI source, it was found that they lost exclusively H2O. As for 2-naphthylamine, 1-aminoanthracene and 2-aminoanthracene, it was found that 2-naphthylamine lost NH3 and a hydrogen atom, NH3being the dominant channel. However, as the ion size 3 increases, the hydrogen-loss channel became the dominant channel. This means that larger PAHs will likely lose exclusively a hydrogen atom to reform the parent radical cation.
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Brewster, Ryan Jude Stephen. "Cometabolic Modeling of Chlorinated Aliphatic Hydrocarbons using SEAM3D Cometabolism Package." Master's thesis, Virginia Tech, 2003. http://hdl.handle.net/10919/37103.
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Bioremediation of chlorinated aliphatic hydrocarbon (CAH) compounds commonly found at contaminated sites has been an area of focus in recent years. The cometabolic transformation of CAH compounds is important at sites where the redox condition does not favor natural attenuation or populations of indigenous microorganisms are relatively low. At sites where the ground-water system is aerobic, monitored natural attenuation strategies will not meet remediation objectives, or both, enhanced bioremediation via cometabolism is an option. Models are needed to simulate cometabolism in an effort to improve performance and design. The SEAM3D Cometabolism Package was designed to address this need. The objective of this report is to model field data to determine the ability of SEAM3D to simulate the performance of cometabolism. A ground-water flow and transport model was designed based on reported parameters used in the field experiments at Moffett Field. Electron donor and acceptor breakthrough curves were also simulated in an effort to calibrate the model. Several data sets describing the cometabolism of CAHs were used in the cometabolism modeling for calibration to field data. The cometabolism modeling showed areas of best fit calibration with modification to the model parameters reported for the pilot tests at Moffett Field. The overall performance of the SEAM3D Cometabolism Package described in this report establishes validation of the model using field experiment results from the literature. Additional model validation is recommended for other contaminants.Master of Science
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Pizzul, Leticia. "Degradation of polycyclic aromatic hydrocarbons by actinomycetes /." Uppsala : Department of Microbiology, Swedish University of Agricultural Sciences, 2006. http://epsilon.slu.se/200650.pdf.
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Candian, Alessandra. "Polycyclic aromatic hydrocarbons in the interstellar medium." Thesis, University of Nottingham, 2012. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.604895.
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The Unidentified Infrared (UIR) bands are a family of emission features seen in dusty objects, which are generally attributed to IR fluorescence of small (~ 50 C-atoms) polycyclic aromatic hydrocarbon (PAH) molecules. However, no specific PAH has so far been identified. The spatial distribution of 3.3 p,m PAH emission in the inner region of the Red Rectangle nebula is studied using an Integral Field spectroscopy technique. The presence of two components at 3.28 and 3.30 p,m with different spatial distributions, originally proposed by Song et al. (2003, 2007) is supported by these data. This implies the presence of two classes of 3.3 p,m band carrier with peak wavelength separation of ",0.02 p,m. From comparison of the 3.3 p,m observations with laboratory and theoretical spectra for a range of PAH molecules it is inferred that the 3.28 p,m and 3.30 p,m components arise from 'bay' and 'non-bay' hydrogen sites, respectively, on the periphery of neutral PAHs. The vibrational spectrum of a large number of PAH molecules are investigated with Density Functional Theory (DFT) calculations to find possible trends which may help in the identification of specific PAHs. It has been found that for acenes (single row), the position of the solo out-of-plane bending mode moves to shorter wavelength with increase number of carbon atoms. A similar behaviour holds also for 2-rows, 3-rows and large compact PAH molecules. Pericondensed and catacondensed PAHs with functional groups are investigated to assess their contribution to the unidentified 21 p,m feature, found in carbon-rich environments. They are unlikely to be responsible for the feature. The results of DFT calculations for large, solo-containing PAHs are then used to model Abstract 4 the asymmetric profile of the 11.2 p,m feature. The IR emission mechanism is taken into account, together with the effects of the DV radiation field in different sources; the temperature dependence of the solo out-of-plane bending mode and position are also considered, using state-of-the-art experimental data. It is found that the model reproduces very well the shape and the val1ations of the 11.2 p,m band in a few environments, supporting the idea that these variations are due to different mass distributions of PAHs, rather than anharmonicity. A similar model is then applied to acenes, which appear to contribute most of the intensity of the 11.0 p,m feature. High-resolution long-slit spectroscopic observations of the 11.2 p,m band in two PNe (NGC 7027 and BD+30° 3639) and in a PDR (The Orion Bar), in a search for fine stmcture have been carried out. While the presence of fine structure cannot ruled out, changes in the 11.2 p,m feature along the Orion Bar, from the molecular cloud to the ionised region, is seen suggesting possible evolution of the carriers of the feature. ..
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Goodman, Michael David. "Polynuclear aromatic hydrocarbons in the marine environment." Thesis, Heriot-Watt University, 1985. http://hdl.handle.net/10399/1611.
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James, Ian M. "Behaviour of aromatic hydrocarbons in urban atmospheres." Thesis, Northumbria University, 2001. http://nrl.northumbria.ac.uk/2681/.
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Quasi-continuous measurement of benzene, toluene, ethylbenzene and isomers of xylene in northern England has been performed using an automated thermal desorption - gas chromatography - flame ionisation detector (TD-GC-FID) system. The TD-GC-FID system was mounted in a mobile laboratory, together with a TEOM (Tapered Element Oscillating Microbalance) system for particulate monitoring, and a weather station. Both systems have been applied to urban and suburban sites in order to examine the behaviour of BTEX aromatics at these localities, under a range of boundary layer environments. Measurement of BTEX aromatics and particulate matter has also been performed within a bus depot, a site which was effectively isolated from the free boundary layer overnight, to contrast the behaviour of BTEX in sunlit and non-sunlit atmospheres. Time series analysis of the concentration ratios of individual BTEX aromatics has been performed and diurnal seasonality has been demonstrated at a number of sites. Significant differential removal of individual BTEX aromatics has been found to occur overnight. Relative removal rates have been measured for this period, and values indicate that accepted tropospheric transformation mechanisms of the BTEX aromatics are not responsible. The available experimental and theoretical evidence collected in this research serves to support the supposition that a physical process, which is related to atmospheric temperature, volatility of individual BTEX aromatics, and pressures of individual BTEX aromatics, governs nocturnal differentiation of the concentration of BTEX aromatics. A postulated effect, which may contribute to nocturnal differential, is preferential absorption of particular BTEX aromatics to a liquid organic carbon phase, which has been shown to be associated with diesel carbonaceous combustion aerosol. The latter supposition has been partially corroborated by the findings of a separate study exploring the composition of carbonaceous combustion aerosol by GCMS, XRF, DTA, DSC, and FTIR.
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Smith, Michael John. "Bioremediation of polycyclic aromatic hydrocarbons in soil." Thesis, University of Kent, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.242929.
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Hoban, T. J. "Polycyclic aromatic hydrocarbons in the Severn Estuary." Thesis, University of South Wales, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.305737.
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Al-Naiema, Ibrahim Mohammed Jasim. "Anthropogenic secondary organic aerosol from aromatic hydrocarbons." Diss., University of Iowa, 2018. https://ir.uiowa.edu/etd/3242.
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Atmospheric aerosols deteriorate visibility and pose a significant risk to human health. The global fluxes of secondary organic aerosols (SOA) that form in the atmosphere from aromatic hydrocarbons are poorly constrained and highly uncertain. The lack of molecular tracers to quantify anthropogenic SOA (ASOA) in part limits the understanding of its abundance and variability, and results in a systematic underestimation of the role of ASOA in the atmosphere. The research presented in this thesis advances the knowledge about ASOA through the i) development of new and advanced methods to quantify potential ASOA tracers, ii) evaluation of their suitability as tracers for ASOA, and iii) application of the validated tracers to assess the spatial, diurnal and seasonal variation of ASOA in three urban environments.
In this research, a greater understanding of the role of ASOA is gained through the expansion of tracers for SOA from aromatic hydrocarbons. An analytical method to quantify furandiones, which are produced in high yields from the photooxidation of aromatic hydrocarbons, was developed and enabled the first ambient measurements of furandiones. The optimized method allows for the simultaneous extraction of primary source tracers (e.g., polycyclic aromatic hydrocarbons, hopanes, levoglucosan) and other potential ASOA tracers (e.g., 2,3-dihydroxy-4-oxopentanoic acid [DHOPA], benzene dicarboxylic acids, and nitromonoaromatics). The systematic evaluation of potential ASOA tracers by their detectability, gas-particle partitioning, and specificity revealed that DHOPA, phthalic acid, 4-methylphthalic acids, and some nitromonoaromatics are good ASOA tracers because they are specific to aromatic hydrocarbon photooxidation, readily detected in ambient air, and substantially partition to the particle phase under ambient conditions. These tracers are thus recommended for use in field studies to estimate ASOA contributions to atmospheric aerosol relative to other sources.
ASOA was determined to be a significant contributor to PM2.5 organic carbon (OC) in three urban environments. In the industrial Houston Ship Channel area in Houston, TX, ASOA contributed 28% of OC, while biogenic SOA (BSOA) contributed 11%. Diurnally, ASOA peaked during daytime and was largely associated with motor vehicle emissions. In Shenzhen, a megacity in China, 13-23% of OC mass was attributed to ASOA, three folds higher than BSOA. When China controlled the emissions from fossil fuel-related sources, the ASOA contribution to OC reduced by 42-75% and visibility remarkably improved. In downtown Atlanta, GA, ASOA contributed 29% and 16% of OC during summer and winter, respectively. ASOA dominates over BSOA during winter, while high biogenic VOC fluxes made BSOA the major SOA source in Atlanta, GA during summertime. These results indicate the high abundance of ASOA in urban air that has potential to be reduced by modification of anthropogenic activities.
Overall, the work presented in this dissertation advances the knowledge about the abundance and variation of ASOA in urban atmospheres through the development of quantification methods and expansion of ASOA tracers. These tracers improve source apportionment of ASOA in receptor based models, which can ultimately aid in developing and implementing effective strategies for air quality management.
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Al-Bashir, Bilal. "Biodegradation of polycyclic aromatic hydrocarbons in soilwater systems." Thesis, McGill University, 1991. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=59963.
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This study is concerned with the biodegradation of polycyclic aromatic hydrocarbons (PAHs), particularly the utilization of biological processes in the bioremediation of PAH-contaminated soils. In this regard, the effects of the contaminant bioavailability and the redox environment on the biodegradation process have been investigated.First, the mineralization of naphthalene in soil/water systems under denitrifying conditions has been studied. Results showed that naphthalene mineralization is influenced by its availability to the microbial population, which in turn is a function of the compound initial concentration, the sorption/desorption characteristics of the soil/contaminant complex and the organic content of the soil.
Second, the biodegradation of four PAH compounds, acenaphthene, acenaphthylene, fluorene and anthracene, in a soil/water system under four redox environments has been studied. Both aerobic and denitrifying environments supported appreciable PAH biodegradation rates. The denitrifying environment was chosen for a further experiment to investigate the performance of a bioreactor system in treating PAH-contaminated soils. Results showed that by enlarging the scale of the reactor by approximately eight times and simultaneously reducing the mixing intensity of the soil slurry, the biodegradation rates of the PAH compounds remained virtually unchanged.
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Petry, Thomas. "Human exposure to airborne polycyclic aromatic hydrocarbons (PAHs) /." [S.l.] : [s.n.], 1994. http://e-collection.ethbib.ethz.ch/show?type=diss&nr=10726.
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Yi, Ling. "Micellar liquid chromatographic separation of polycyclic aromatic hydrocarbons /." free to MU campus, to others for purchase, 2004. http://wwwlib.umi.com/cr/mo/fullcit?p1426117.
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Diegor, Elizabeth Justa M. "Biodegradation of aromatic hydrocarbons : microbial and isotopic studies /." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape4/PQDD_0016/MQ55501.pdf.
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Godschalk, Roger Wilhelmus Laurentius. "Biological markers for exposure to polycyclic aromatic hydrocarbons." Maastricht : Maastricht : Universiteit Maastricht ; University Library, Maastricht University [Host], 1999. http://arno.unimaas.nl/show.cgi?fid=6862.
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Gachanja, Anthony Ngure. "Analysis of polycyclic aromatic hydrocarbons from biomass combustion." Thesis, University of Hull, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.335081.
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Seitz, Fabian. "Ions colliding with Polycyclic Aromatic Hydrocarbons and Fullerenes." Doctoral thesis, Stockholms universitet, Fysikum, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-88427.
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In this thesis a series of experiments on collisions between atomic projectile ions at keV energies and target vapors of either isolated molecules or van der Waals clusters is presented and analyzed. The atomic ions are produced in an Electron Cyclotron Resonance (ECR) ion source, accelerated and guided into the target volume. The charged target collision products are mass-to-charge analyzed in a time-of-flight spectrometer. The Polycyclic Aromatic Hyrdrocarbons (PAHs) Anthracene (C14H10), Coronene (C24H12), two C16H10 isomers, Pyrene and Fluoranthene, and the fullerene C60 are examined. For projectile ions in low charge states, small impact parameter collisions dominate, which leads to internal heating of the target. With isolated molecules as targets, this typically results in ionization and often also in fragmentation. For cluster targets energy and charge are rapidly distributed among the cluster building blocks. This is followed by cluster evaporation and very limited fragmentation of the individual molecules. C119+ and C118+ are observed as products. These are due to the formation of the reactive C58/59+ ions by direct knockout processes, which react with another C60 of the cluster to form dumb-bell shaped molecules. For projectile ions of high charge (Xe20+) larger impact parameters dominate, leading to little internal heating. For isolated molecule targets, intact molecular ions are the main collision products. Charged fragments stem mostly from multifragmentation following ionization to high charge states. For cluster targets, the collision products consist mainly of singly charged monomers. Fragmentation of the individual molecules is comparatively strong. This suggests a quick distribution of charges followed by a Coulomb explosion, which leads to internal heating. The results show that weakly bound clusters do not sustain the impact of keV-ions and that it is possible to form new molecular structures.At the time of doctoral defense, the following papers were unpublished and had a status as follows: Paper 5: Submitted. Paper 6: Submitted.
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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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Pushparajah, Daphnee S. "Interactions between polycyclic aromatic hydrocarbons in the liver." Thesis, University of Surrey, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.436082.
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Jaskolka, John E. "Polycyclic Aromatic Hydrocarbons (PAH) Exposure in Firefighter Recruits." University of Cincinnati / OhioLINK, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1250636298.
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Bryant, Yazmina Mercedes. "Interactions of polycyclic aromatic hydrocarbons with mineral surfaces." Thesis, University of Manchester, 2011. https://www.research.manchester.ac.uk/portal/en/theses/interactions-of-polycyclic-aromatic-hydrocarbons-with-mineral-surfaces(a81215d1-4510-48c8-ad75-a5b6433e80de).html.
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The toxicity and ubiquitousness of PAHs within different terrestrial environments has been an increasing cause for concern amongst environmental scientists in the last decades, in particular regarding their transport within the soil. In an attempt to understand the role of pure inorganic phases in PAH-mobility; experiments exposing mineral soil components with low organic matter content to a PAH-representative were carried out. The systems consisted of four different mineral phases (quartz sand, hematite, iron coated quartz sand and montmorillonite) which were individually exposed to naphthalene in electrolyte solutions prepared at increasing ionic strengths (NaNO3: 0.001 M; 0.01 M; 0.1 M) and pH (4.0 and 5.5). All experiments were conducted over at 24 reaction intervals and at ambient temperature conditions.Mineral geosorbents are traditionally known to be poor PAH-scavengers; in particular when compared to organic, high surface area materials such as activated carbons. On this basis, a preliminary validation experiment (Proof of Concept Experiment) was conducted to test the sensitivity of the selected extraction method (SPME) under complete uptake (activated carbon) and very low uptake (quartz sand) conditions. By extracting and analysing the supernatant after 24 hr of exposure of both sorbents to naphthalene under identical conditions it was concluded that SPME was a feasible extraction technique, yielding good reproducibility (n=3, inter-day RSD%= 11.18% ) even at very low PAH concentrations (0.2 µg / L). The final concentration of naphthalene in the sample supernatant after 24 hours was determined by GC-FID. All samples were extracted using the Solid Phase Microextraction method developed during the Proof of Concept which allowed the rapid extraction of naphthalene in the headspace HS-SPME (extraction time = 3 minutes) using temperature control and ultrasonication as means of agitation. Each sample set included triplicates of blanks and samples as well as calibration standards (in duplicate where possible)Out of the four minerals, only quartz sand and hematite showed a slight tendency towards naphthalene removal from solution; a finding which correlated well with increasing ionic strength. The other two minerals did not show any such trend and the results were deemed inconclusive. In regards to the results for quartz and hematite; the detected uptake was found to be below the sensitivity of the current SPME extraction method according to the error analysis carried out by comparing the sample and blank means whilst accounting for error equal to 1σ. The overlapping of both means in the majority of the samples indicated that both averages were too close to be accurately resolved (due to very low naphthalene uptake). Modifications to the SPME method could improve the reproducibility and decrease the spread of the data; however, this measure would only guarantee higher statistical confidence (95 %) and not higher naphthalene uptake by these minerals. These observations lead to the conclusion that naphthalene was being salted out of solution rather than being removed by sorption; and under these experimental conditions it would not have been possible to detect any real PAH-mineral interaction. In view of this outcome, a different approach was attempted in order to detect surface reactions between the minerals and naphthalene. A series of preliminary (qualitative) surface analysis (AFM, XPS and ATR-FTIR) on pre-loaded mineral specimens were carried out in air at ambient temperature conditions. No naphthalene was positively identified on the surfaces of the studied sorbents. Factors such as molecular size, sorbents characteristics (i.e. roughness, surface charge) and loading conditions impeded the detection of the target molecules. Innovative sample preparation protocols as well as controlled analytical conditions would need to be implemented and evaluated before this kind of analytical tool can be used. The main outcome of this research work was the successful adaptation of SPME to the rapid extraction of naphthalene in electrolyte solutions at optimal and sub-optimal concentration levels; as the proof of concept preliminary experiment showed.
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Bagga, Amit. "Femtosecond Laser Mass Spectroscopy of Cyclic Aromatic Hydrocarbons." Thesis, Université d'Ottawa / University of Ottawa, 2018. http://hdl.handle.net/10393/37098.
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Cyclic Aromatic molecules are the subject of continued research due to their highly advantageous characteristics which can be exploited in the areas of pharmaceuticals, material science and nano-electronics. While the defining properties and criteria for a molecule to be considered aromatic are very specific and well established, the degree of aromaticity of these molecules and their corresponding ordering remains a source of continued debate. Given that the macroscopic aromatic properties are fundamentally rooted in the underlying electronic structure and molecular dynamics, these properties can be probed in numerous ways. One such method is to exploit the strong laser field as it pertains to non-linear light-matter interaction. More specifically, the study of photoionization, as a direct resultant effect of strong field light-matter interaction, gives us direct insight into electronic and spatial properties as captured via mass spectroscopy. As a strong-field process, photoionization is effective because the variables that influence its results are also the ones that define aromaticity thus a correlation can be postulated. Other strong field advanced techniques to probe aromacity such as High Harmonic Generation (HHG) have already been successful shown by our group to be effective spectroscopic tools. In this way, photoionization provides supporting evidence to enhance the understanding of these novel spectroscopic tools. This thesis demonstrates that photoionization mass spectroscopy can be used as a probe into the aromaticity order of 5-membered cyclic aromatic molecules. Furthermore, the thesis will show that photoionization results correlate with the previously conducted HHG studies in this area thus further supporting these techniques as sensitive spectroscopic tools into aromaticity. The first part of this thesis describes the characterization of aromatic molecules and the corresponding process to obtain photoionization results that can be correlated to aromaticity. In the second part, these results are compared to the theoretical model and HHG demonstrating consistent results. The third and final component of this thesis describes future work, namely two-colour control of photoionization which is intended to provide greater resolution and variation of photoionization spectra thereby providing a more comprehensive and conclusive understanding of the proposed correlation with aromaticity.
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Nishino, Noriko. "Mechanistic studies of atmospheric chemical reactions of hydroxyl radicals with aromatic hydrocarbons, including 2-ring polycyclic aromatic hydrocarbons, and terminal alkenes." Diss., UC access only, 2009. http://proquest.umi.com/pqdweb?index=94&did=1907248571&SrchMode=1&sid=1&Fmt=7&retrieveGroup=0&VType=PQD&VInst=PROD&RQT=309&VName=PQD&TS=1270251046&clientId=48051.
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Onchoke, Kefa Karimu. "Experimental and theoretical studies of nitrated polycyclic aromatic hydrocarbons." Columbus, Ohio : Ohio State University, 2006. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1143220534.
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Mannion, Michael R. "Synthesis and chemistry of highly distorted polycyclic aromatic hydrocarbons." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape7/PQDD_0017/NQ52693.pdf.
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McConkey, Brendan. "Environmental photooxidation and mixture toxicity of polycyclic aromatic hydrocarbons." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape8/PQDD_0028/NQ51212.pdf.
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Parbin, Elbin Sehnza. "Synthesis of polycyclic aromatic hydrocarbons via benzannulated enediynyl alcohols." Morgantown, W. Va. : [West Virginia University Libraries], 2007. https://eidr.wvu.edu/etd/documentdata.eTD?documentid=5331.
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Thesis (M.S.)--West Virginia University, 2007.Title from document title page. Document formatted into pages; contains vii, 65 p. : ill. Includes abstract. Includes bibliographical references (p. 33-36).
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Hatjian, Berj Armen. "Risk assessment of occupational exposure to polycyclic aromatic hydrocarbons." Thesis, University of Newcastle Upon Tyne, 1995. http://hdl.handle.net/10443/372.
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A novel strategy was used to assess the risk to health from exposure to polycyclic aromatic hydrocarbons (PAHs), an important class of chemical carcinogens, in workers in the paving and roofing industries using bitumen. The aim was to evaluate the risk of exposure to PAHs at three different stages: these were external exposure "external dose", internal exposure "internal dose" and biological effect "biologically effective dose". The approaches used for quantifying the risk at these stages were ambient monitoring, biological monitoring and biological effect monitoring, respectively. Ambient monitoring was carried out by personal air sampling and measurement of PAH-exposure. Excretion of thioethers (a non-selective biomarker) and 1-hydroxypyrene (a selective biomarker of exposure to pyrene) in urine were determined. Urinary d-glucaric acid, sister chromatid exchange in peripheral blood lymphocytes and micronuclei in exfoliated cells were use for biological effect monitoring. Seven groups of workers were studied. These were office workers, departmental staff and manual workers who were not occupationally exposed to PAHs and who were included as controls, and two groups of payers and roofers who were exposed to bitumen fumes during their work. The ambient monitoring program revealed that concentrations of PAHs in environmental air could be as high as those found in the payers' and roofers' occupational environments. The contribution of these background levels to the external dose of the pa yers and roofers was considerable. Payers and roofers were occupationally exposed to low levels of PAHs. The PAH profile in the personal air sample of the workers was different between the two industries. This was attributed to the presence of PAH-emission sources other than hot bitumen, such as vehicle exhaust. The concentration of naphthalene measured in air samples was a good indicator for identifying the existence of these sources. The quantitative evaluation of the carcinogenic risk inherent in the external dose using the 8 hour TWA concentration as a measuring stick did not seem to be effective due to the low "noise" levels of carcinogenic PAHs present. A semi-quantitative measure of the external exposure was suggested which appeared to be a better reflection of the carcinogenic risk. Urinary thioethers are not sensitive enough to be used as a nonselective biomarker of exposure to low levels of PAHs; however, urinary 1- hydroxypyrene was a good indicator of internal exposure to pyrene and therefore PAHs in bitumen fume. The relationship between 1-hydroxypyrene in urine and specific airborne PAH-exposure indices in the results of the payers, but not the roofers, suggested that the route of exposure in the latter is mainly dermal while that in the payers is more related to respiratory uptake. This observation, however, did not agree with the subjective occupational hygiene assessment where it was observed that the roofers were closer to the source of PAH-emissions due to the nature of their job and both groups did not use any respiratory or personal protective equipment. The measurement of urinary d-glucaric acid excretion suggested, but not strongly, that hepatic enzyme activity was induced in the occupationally PAH-exposed groups in comparison to controls and reflected the internal dose of pyrene or total PAHs. These observation; however, need further investigation. Micronuclei in exfoliated epithelial cells could not be measured in these populations as insufficient bladder epithelial cells were obtained for analysis. Sister chromatid exchange in peripheral blood lymphocytes of payers and roofers was significantly elevated in comparison to control and manual worker group. The group mean frequencies of SCE were significantly correlated with the external exposure to carcinogenic PAHs. This observation suggested that sister chromatid exchange is a very sensitive cytogenetic endpoint and is useful for evaluating the risk of exposure to low levels of carcinogenic PAHs. Risk assessment, such as the one conducted in this study, allows a quantitative estimation of risk associated with long-term exposure to moderate and low levels of airborne exposure to PAHs in bitumen fume. Knowledge of dose response relationship may allow a review of current Occupational Exposure Standards (OES) and Biological Exposure Limits, which are at present either unavailable or based on poor background scientific knowledge for most PAH compounds. In this study we have suggested an Occupational Exposure Limit for PAHs based on the sum of fourteen PAH-species.
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Ives, Sian E. "The biodegradation of polycyclic aromatic hydrocarbons (PAHs) in groundwater." Thesis, University of Huddersfield, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.368319.
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O'Kane, Gerard Anthony. "Metabolites and potential metabolites of polycyclic aromatic hydrocarbons (PAH's)." Thesis, Queen's University Belfast, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.317097.
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