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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
41

Rapid quantitative and qualitative screening of naphthenic acids in contaminated waters using condensed phase membrane introduction mass spectrometry

Letourneau, Dane Rene 20 May 2016 (has links)
Naphthenic acids (NA) are a highly complex mixture of aliphatic carboxylic acids that may contain multiple rings and unsaturated double bonds, and are a subset of the naphthenic acid fraction components (NAFC), which can contain heteroatoms, unsaturations, and aromatic structures. Mono-carboxylated NAs can be classically represented by CnH2n+zO2 where z is a negative integer representing the hydrogen deficiency. NAs and NAFCs are components of the acid extractable organics (AEO) frequently associated with increased toxicity and observed at elevated concentrations in oil sands process waters (OSPW). Numerous chromatographic and mass spectrometry techniques have recently emerged to probe the composition and concentrations of these components. This thesis reports the use of a capillary hollow fiber polydimethylsiloxane (PDMS) membrane mounted on a probe interface that can be immersed directly into an aqueous sample. A methanol acceptor phase passing through the lumen transports analyte to an electrospray ionization source and a triple quadrupole mass spectrometer. This technique, termed condensed phase membrane introduction mass spectrometry (CP-MIMS), allows for rapid screening of m/z profiles and on-line quantification of NAs in complex samples within minutes. This thesis reports parametric studies of several model carboxylic acids and a standard naphthenic acid mixture (Merichem) involving the effect of sample pH on membrane transport and acceptor phase pH on ionization enhancement. Several quantitative strategies are explored including the use of an internal standard in the acceptor phase to correct for ionization suppression and variations in instrument sensitivity, and the use of selected ion monitoring (SIM) experiments to increase analytical sensitivity and potentially target specific NA isomer classes for quantitation. Analytical performance measures such as the linear dynamic range (1-2300 ppb [NA]T as Merichem), sensitivity (~1 ppb [NA]T as Merichem detection limit), precision (~20 %RSD for replicates of a single OSPW) and accuracy are reported. Quantitative results for various OSPW samples in the ppb to ppm range are reported as equivalents of several surrogates, including 1-pyrenebutyric acid (PyBA), Merichem, and a large-volume extract of northern Alberta OSPWs. The variety of quantitation strategies allows results to be compared with several other published methods. CP-MIMS results for three mid-range northern Alberta OSPWs are compared to analysis by Environment Canada with an average -21% bias. Results for five archived OSPWs spanning a wider concentration are compared to data from AXYS Analytical, with an average -49% bias. Applications of CP-MIMS as an in-situ monitor of removal efficiencies of NAs on adsorbents and real-time mass profile changes are also presented, along with some interpretation of the resulting high-resolution kinetic data to obtain decay constants. Using the targeted SIM method, adsorption decay can be followed in real-time for various isomer classes within the Merichem mixture, and kinetic data extracted to obtain decay constants for each. CP-MIMS is also used to characterize adsorption behavior for two activated biochars, including % removals for various loadings of each when added to stirred Merichem solutions. Preliminary multi-loading experiments are conducted with one biochar, and the ability of CP-MIMS to characterize adsorbent behavior by constructing adsorption isotherm plots is demonstrated. / Graduate
42

Determining food web impacts on experimental aquatic systems from the disposal of oil sands process-affected waste materials.

Elshayeb, Monalisa January 2006 (has links)
Current mining operators in the Athabasca oil sands deposit of Alberta, Canada have made commitments to zero discharge of oil sands process-affected waste materials (OSPM) from the mine site and rehabilitation of mined lands to a pre-mining state. As part of aquatic reclamation efforts, experimental test sites that contain a range of OSPM (solid and liquid components) were constructed to monitor the evolution and viability of aquatic habitats used as disposal sinks for OSPM produced by mining activities. In the present study, stable isotopes of carbon, nitrogen and sulphur were used to gauge some of the potential effects of OSPM site construction methods on aquatic food webs. Carbon and nitrogen isotopic signatures of sediment, dissolved inorganic carbon, dissolved organic carbon, particulate organic matter, periphytic material, plants, plankton, aquatic invertebrates and fish were used to assess differences related to the naphthenic acid (NA) concentration in OSPM and reference sites. For statistical analyses, sites were grouped into low (0 to 4 mg/L), medium (4 to 15 mg/L) and high (> 15 mg/L) NA concentrations. There were no significant differences in food web area or food web length among the low, medium and high NA concentration sites. In most cases, sample carbon isotope analyses of low, medium and high NA concentration sites were not significantly different, suggesting food web carbon sources did not include significant contributions from OSPM materials at OSPM sites. Significant differences, however, were found in the sample nitrogen isotope signatures between low, medium and high NA concentration sites. Ammonia from OSPM is suggested to be the main contributor to &delta;<sup>15</sup>N enrichment. <br /><br /> To determine the potential effects of site construction and OSPM within experimental test sites, carbon and sulphur stable isotopes of water, plankton, aquatic invertebrates and fish were analyzed. With the exception of <em>Chaoborus</em> and <em>Haliplus</em>, all carbon isotope signatures were not significantly different in constructed and reference sites. Also with the exception of <em>Haliplus</em>, sulphur isotope values for aquatic organisms from constructed and reference sites were significantly different. Aquatic organisms and water samples from constructed sites built in, or close, to the boundary of Kcw clays typically had &delta;<sup>34</sup>S < 0 ?. Coinciding with depleted &delta;<sup>34</sup>S signatures found in these aquatic systems were elevated sulphate concentrations. The waters at experimental test sites are in direct contact with the soil materials that facilitate the accumulation of sulphates as a result of the oxidation of substrate sulphide minerals. In general the results of the study suggest that aquatic food web structure and function do not change with the introduction of OSPM. Shifts in isotopic signatures suggestive of changes in food web structure, however, do occur when site construction exposes Kcw clays in the substrate.
43

Determining food web impacts on experimental aquatic systems from the disposal of oil sands process-affected waste materials.

Elshayeb, Monalisa January 2006 (has links)
Current mining operators in the Athabasca oil sands deposit of Alberta, Canada have made commitments to zero discharge of oil sands process-affected waste materials (OSPM) from the mine site and rehabilitation of mined lands to a pre-mining state. As part of aquatic reclamation efforts, experimental test sites that contain a range of OSPM (solid and liquid components) were constructed to monitor the evolution and viability of aquatic habitats used as disposal sinks for OSPM produced by mining activities. In the present study, stable isotopes of carbon, nitrogen and sulphur were used to gauge some of the potential effects of OSPM site construction methods on aquatic food webs. Carbon and nitrogen isotopic signatures of sediment, dissolved inorganic carbon, dissolved organic carbon, particulate organic matter, periphytic material, plants, plankton, aquatic invertebrates and fish were used to assess differences related to the naphthenic acid (NA) concentration in OSPM and reference sites. For statistical analyses, sites were grouped into low (0 to 4 mg/L), medium (4 to 15 mg/L) and high (> 15 mg/L) NA concentrations. There were no significant differences in food web area or food web length among the low, medium and high NA concentration sites. In most cases, sample carbon isotope analyses of low, medium and high NA concentration sites were not significantly different, suggesting food web carbon sources did not include significant contributions from OSPM materials at OSPM sites. Significant differences, however, were found in the sample nitrogen isotope signatures between low, medium and high NA concentration sites. Ammonia from OSPM is suggested to be the main contributor to &delta;<sup>15</sup>N enrichment. <br /><br /> To determine the potential effects of site construction and OSPM within experimental test sites, carbon and sulphur stable isotopes of water, plankton, aquatic invertebrates and fish were analyzed. With the exception of <em>Chaoborus</em> and <em>Haliplus</em>, all carbon isotope signatures were not significantly different in constructed and reference sites. Also with the exception of <em>Haliplus</em>, sulphur isotope values for aquatic organisms from constructed and reference sites were significantly different. Aquatic organisms and water samples from constructed sites built in, or close, to the boundary of Kcw clays typically had &delta;<sup>34</sup>S < 0 ?. Coinciding with depleted &delta;<sup>34</sup>S signatures found in these aquatic systems were elevated sulphate concentrations. The waters at experimental test sites are in direct contact with the soil materials that facilitate the accumulation of sulphates as a result of the oxidation of substrate sulphide minerals. In general the results of the study suggest that aquatic food web structure and function do not change with the introduction of OSPM. Shifts in isotopic signatures suggestive of changes in food web structure, however, do occur when site construction exposes Kcw clays in the substrate.
44

Remoção de compostos ácidos do petróleo em diferentes tipos de carvão ativado / Acid compounds removal from oil crude in different types of activated carbons

Araújo, Anderson Barros Caixeta 29 February 2016 (has links)
Submitted by Cássia Santos (cassia.bcufg@gmail.com) on 2016-09-20T11:12:34Z No. of bitstreams: 2 Dissertação - Anderson Barros Caixeta Araújo - 2016.pdf: 3153002 bytes, checksum: ba1e261db38d81f09762632dfc921e8b (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2016-09-20T11:58:38Z (GMT) No. of bitstreams: 2 Dissertação - Anderson Barros Caixeta Araújo - 2016.pdf: 3153002 bytes, checksum: ba1e261db38d81f09762632dfc921e8b (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2016-09-20T11:58:39Z (GMT). No. of bitstreams: 2 Dissertação - Anderson Barros Caixeta Araújo - 2016.pdf: 3153002 bytes, checksum: ba1e261db38d81f09762632dfc921e8b (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2016-02-29 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / The naphthenic acids comprise a complex mixture of carboxylic acids that are present in petroleum. They are directly responsible for the oil acidity and its corrosiveness in liquid phase during the refining process. Such compounds are also presents in the derivatives, causing several problems to product quality. A possible way of removing these acids from those oil fractions is using the adsorption process in porous solids, as activated carbons. There are few studies about the removal of naphthenic acids on coals. For this reason, we chose four types of activated carbons for adsorption tests, and they coal babassu, palm kernel, coconut and of Bahia ox bone. In order to assess the possibility of further removing acidic compounds, the four carbons were subjected to a chemical treatment with concentrated sodium hydroxide. Physical and chemical analyzes were performed in order to promote the characterization of all adsorbents, showing that the treatment previously mentioned was leading to an increase in the adsorption capacity of the coals. The adsorption experiments with commercial batch naphthenic acid solution showed that the treated ox bone char had the highest retention efficiency, which is the adsorbent used to construct the adsorption isotherms. The isotherms were better adjusted by Langmuir model, revealing the chemisorption of character adsorptive process. The thermodynamic data showed that the process is spontaneous and endothermic, is favored by increasing the temperature. Regarding the crude oil sample, batch adsorption experiments were conducted in such a way as to determine the removal efficiency of class O2 and reducing the Total Acid Number (IAT). The results spectrometry FTICR ix MS Pasta, they showed that all coals chemically treated were able to remove more acidic compounds in relation to their untreated related. The raw coals babassu oil, palm oil and coconut Bahia showed a potential for adsorption of nitrogen compounds from oil, given that there was a decrease in its class in the class chart. As a final analysis, all the coals were evaluated for their ability to lower oil IAT, it was found that the ox bone char treated again achieved the best result, reducing by 70% the value of the IAT. / Os ácidos naftênicos correspondem à complexa mistura de ácidos carboxílicos presentes no petróleo, responsáveis diretamente pela sua acidez e pela sua corrosividade em fase líquida durante o refino. Tais compostos também estão presentes nas frações destiladas do petróleo, causando diversos problemas na qualidade final do produto. Uma alternativa para a remoção desses ácidos das frações destiladas é por meio da adsorção em materiais porosos, como os carvões ativados. Poucos são os estudos a respeito da remoção de ácidos naftênicos em carvões. Por esta razão, foram escolhidos quatro tipos de carvões ativados para os ensaios de adsorção, sendo eles carvão de babaçu, dendê, coco da Bahia e osso de boi. A fim de avaliar a possibilidade de uma maior remoção de compostos ácidos, os quatro carvões foram submetidos a um tratamento químico com solução concentrada de hidróxido de sódio. Análises físico-químicas foram realizadas com o intuito de promover a caracterização de todos os adsorventes, revelando que o tratamento anteriormente citado foi preponderante para um aumento na capacidade adsortiva dos carvões. Os ensaios de adsorção em batelada com solução comercial de ácidos naftênicos mostraram que o carvão de osso de boi tratado apresentou a maior eficiência de retenção, sendo este o adsorvente utilizado para a construção das isotermas de adsorção. As isotermas foram melhor ajustadas pelo Modelo de Langmuir, revelando o caráter de quimiossorção do processo adsortivo. Os dados termodinâmicos mostraram que o processo é espontâneo e endotérmico, sendo mais favorecido pelo aumento da temperatura. Em relação à amostra de petróleo bruto, ensaios de adsorção em batelada foram conduzidos de tal forma a averiguar a eficiência na remoção da classe O2 e na redução do Índice de Acidez Total (IAT). Os resultados de Espectrometria de Massas FT-ICR MS, mostraram que todos os carvões tratados quimicamente conseguiram remover mais compostos ácidos em relação a seus correlatos não tratados. Os carvões brutos de babaçu, dendê e coco da Bahia apresentaram uma potencialidade para adsorção de compostos nitrogenados do petróleo, haja vista que houve a diminuição desta classe no gráfico de classes. Como análise final, todos os carvões foram avaliados quanto suas capacidades de redução do IAT do petróleo, em que foi constatado que o carvão de osso de boi tratado novamente conseguiu o melhor resultado, reduzindo em 70% o valor do IAT.
45

Petroleômica : caracterização de petróleos nacionais por espectrometria de massas de altíssima resolução: que os compostos ácidos podem revelar sobre o petróleo / Petroleomics : characterization of Brazilian crude oils by ultra high resolution mass spectrometry: what acidic compounds can reveal about petroleum

Pereira, Rosana Cardoso Lopes, 1959- 22 August 2018 (has links)
Orientadores: Marcos Nogueira Eberlin, Eugenio Vaz dos Santos Neto / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Química / Made available in DSpace on 2018-08-22T16:54:54Z (GMT). No. of bitstreams: 1 Pereira_RosanaCardosoLopes_D.pdf: 5832219 bytes, checksum: 88820b58f8b6360b78a6aa2f16ceb943 (MD5) Previous issue date: 2012 / Resumo: Este trabalho consistiu na aplicação de tecnologia que se encontra hoje na vanguarda do conhecimento: a Petroleômica via ESI FT-ICR MS, com o objetivo de caracterizar as mais diversas classes de compostos polares ácidos presentes em amostras representativas de óleos de bacias brasileiras. O propósito ambicioso foi o de focalizar aspectos relacionados à toda cadeia de valor da indústria do petróleo, desde a geração do óleo até o seu refino, visando contribuir para novos estudos de interesse às atividades de upstream e downstream da PETROBRAS e, principalmente, fomentar a integração dos conhecimentos das diferentes áreas, o que contribuirá para ganhos de produtividade da empresa. A técnica ESI FT-ICR-MS mostrou-se uma técnica rápida e adequada para acompanhar as alterações verificadas na composição de amostras de petróleo, fornecendo subsídios a partir de uma caracterização única, para estudos diversos, abrangendo toda a cadeia de valor da indústria do petróleo. As alterações composicionais de óleos e extratos obtidos em experimentos de maturação artificial por hidropirólise de matéria orgânica dos tipos I e III foram avaliadas, evidenciando o potencial da técnica para utilização em estudos cinéticos. O estudo de biodegradação utilizando trinta amostras de óleos da Bacia Potiguar evidenciou que a técnica é sensível as variações de composição dos compostos polares que ocorrem em função do processo de biodegradação, e as amostras puderam ser agrupadas de acordo com o grau de biodegradação através da utilização de ferramentas quimiométricas (PCA). A partir dos dados de caracterização obtidos por ESI FT-ICR MS, foi possível agregar informações úteis para o entendimento de comportamentos diferenciados frente à tendência de formação de emulsão/gel durante a produção e frente à corrosão durante o refino / Abstract: This work focuses on the application of a technology that is cutting edge: Petroleomics by ESI FT-ICR MS with the goal of characterizing the large variety of acidic polar compound classes present in representative petroleum samples from Brazilian basins. The ambitious proposal was to focus on aspects related to the whole petroleum industry chain, since crude oil generation up to its processing in refinery units, to contribute to state-of-the-art studies of interest to upstream and downstream activities in PETROBRAS and mostly to encourage the knowledge integration, i.e. to form or blend the information into a whole, to UNITE, accessing high levels of productivity. The ESI FT-ICR MS technique exhibits characteristics like fast response, resolution, selectivity and sensibility, which make it suitable to monitor the changes in composition of petroleum samples and because of its unique and comprehensive characterization attained, to help different studies in the whole petroleum industry chain. The compositional alteration observed in extracts and oils during artificial maturation experiments by hydrouspyrolysis of organic matter types I and III were evaluated showing the potential of the technique to kinetic studies. Biodegradation studies were performed on 30 petroleum samples from Potiguar Basin and the results showed that the technique is sensitive to the variations on the composition of the polar compounds that occur as a result of the biodegradation process, and additionally, that the samples can be grouped according to their biodegradation level by the use of chimiometric tools (PCA). Also from the characterization data from ESI FT-ICR MS analysis it was shown that very useful information can be provided to better understand the differences in the rheological and corrosion behaviors of petroleum samples / Doutorado / Quimica Analitica / Doutora em Ciências
46

Mechanism of Corrosion by Naphthenic Acids and Organosulfur Compounds at High Temperatures

Jin, Peng January 2013 (has links)
No description available.
47

Condensed phase membrane introduction mass spectrometry

Duncan, Kyle Daniel 17 December 2015 (has links)
Over the last few decades, membrane introduction mass spectrometry (MIMS) has been established as a robust tool for the on-line continuous monitoring of trace gases and volatile organic compounds. However, the range of amenable anlaytes has been limited by the need for molecules to pervaporate into a gaseous acceptor phase, or high vacuum environment of a mass spectrometer. This thesis expands the range of amenable analytes for MIMS to include larger, less volatile molecules (e.g., 200 to 500 Da), such as pharmaceuticals, persistent organic pollutants, and small biomolecules. This was achieved through the use of a liquid|membrane|liquid interface. We distinguish the technique from conventional MIMS, which uses a gaseous acceptor phase, by inserting the prefix ‘condensed phase’ to emphasize the use of a solvent acceptor phase – thus yielding CP-MIMS. An initial flow-cell interface with a methanol acceptor phase was characterized, yielding detection limits for model analytes in pptr to ppb, and analyte response times from 1-10 minutes. The flow cell interface was miniaturized into an immersion style CP-MIMS probe (~2 cm), which allowed for analysis of smaller volume samples and improved membrane washing capabilities. Comparable detection limits were observed for the immersion probe, however, it was noticed that significant analyte depletion was observed for samples under 2 mL. In addition, each of the developed membrane interfaces were observed to suffer from ionization suppression effects from complex samples when paired with ESI. Several strategies for mitigating ionization suppression using CP-MIMS are presented, including the use of a continuously infused internal standard present within the acceptor solvent. The developed CP-MIMS system was challenged with the analysis of naphthenic acids (a complex mixture of aliphatic carboxylic acids) directly in contaminated real-world samples. The method used negative ESI to rapidly screen and mass profile aqueous samples for naphthenic acids (as [M-H]-), with sample duty cycles ~20 min. However, it was found that Negative ESI did not differentiate hydroxylated and carboxylated analytes, and both species contributed signal to the total naphthenic acid concentration. To increase method specificity for carboxylic acids, barium ion chemistry was used in conjunction with positive ion tandem mass spectrometry. Common product ions were used to quantify carboxylated analytes, while a qualifier ion was used to confirm the functionality. The increased selectivity afforded by the barium ion chemistry was at the cost of a modest increase in detection limits. CP-MIMS has been established as a technique capable of the direct analysis of real-world samples, and shows promise as a rapid screening method for amenable environmental contaminants and/or biomolecules. / Graduate / 0486 / 0485 / kyle.duncan@viu.ca
48

Étude de la stabilité des émulsions et de la rhéologie interfaciale des systèmes pétrole brut/eau : influence des asphaltènes et des acides naphténiques / Study of the water in oil emulsions and interfacial rheology for crude oil/water systems : influence of asphaltenes and naphthenic acids

Flesinski, Lionel 14 December 2011 (has links)
La formation d'émulsions eau-dans-huile stables est un problème majeur rencontré par les pétroliers au niveau de la production mais aussi du raffinage. Afin d'essayer de prévoir ce phénomène, Total a développé une méthode de classement des huiles qui permet, à partir de leurs propriétés physico-chimiques, de déterminer a priori leur capacité à former ou non des émulsions stables. Cependant, les mécanismes interfaciaux sous-jacents ainsi que l’influence des molécules tensioactives du brut sur la stabilité des émulsions n’est pas très clair. Notre travail a consisté à étudier la contribution des acides naphténiques et des asphaltènes dans les phénomènes observés. L’étude d’huiles réelles a permis d’établir un lien entre la stabilité des émulsions et la formation à l'interface d'un gel 2D. Les études menées sur les huiles réelles dont les acides naphténiques ont été extraits ont permis de montrer que ces derniers, en compagnie de leurs formes ionisées, les naphténates, ont la capacité de réduire la stabilité des émulsions en diminuant la résistance du gel interfacial, ou même en empêchant sa formation. Les expériences réalisées sur les huiles réelles dépourvues d’asphaltènes ont permis de confirmer le rôle stabilisant des asphaltènes. Les résultats obtenus suggèrent que les asphaltènes s’adsorbent sur le gel 2D déjà formé par des tensioactifs passés de l’huile vers l’eau et le rapprochent ainsi de sa transition vitreuse. La résistance du gel interfacial s'en trouve alors augmentée, ce qui conduit à la formation d'émulsions plus stables. En croisant le classement industriel des bruts opéré par Total et les résultats de l’étude, un mécanisme global, régi par la compétition entre les acides naphténiques, les naphténates et les asphaltènes à l’interface E/H est proposé pour expliquer les différences de stabilité observées avec les différentes huiles. Lorsque les acides et les naphténates sont suffisamment concentrés, ils empêchent la formation du gel interfacial et les émulsions sont peu stables. Lorsqu’ils sont moins concentrés le rôle des asphaltènes peut alors devenir prépondérant en donnant une cohésion plus importante au gel qui se rapproche de sa transition vitreuse, ce qui conduit en général au renforcement de la stabilité des émulsions formées. / Water-in-crude oil emulsions are a major issue for oil companies in both production and refining facilities. Thanks to physical and chemical characterizations, Total set a classification which allows the decision of a crude oil ability to create stable emulsions. However the interfacial mechanisms implied and the influence of the indigenous surfactants of crude oil remain unclear. Our work consists in studying the naphthenic acids and asphaltenes contribution to the w/o emulsion stability. The study of realistic crude oils enabled the discovery of a link between the emulsion stability with the formation of a very particular interfacial behavior: a two-imensional gel. Experiments with desacidified oils have proven the destabilizing ability of naphthenic acids and their ionized form, naphthenates. They actually decrease the interfacial gel strength and can even prevent the gel formation. Asphaltenes-free crude oils have permitted to confirm the stabilizing role of asphaltenes. Rather than adsorbing directly on the interface, asphaltenes seem to adsorb on the interfacial gel already formed. The gel strength is thus increased and lead to higher emulsion stability. Thanks to these results and the industrial classification of crude oil developed by Total, a global mechanism explaining the emulsion stability process has been proposed. This mechanism is governed by the competition between asphaltenes, naphthenates and naphthenic acids at the water/oil interface. If the concentration of naphthenic acids and naphthenates is high enough, the interfacial gel cannot be formed and the emulsions are unstable. If the crude oil is not acidic enough, the asphaltenes influence increases dramatically and implies the strengthening of the gel which becomes closer to his glass transition. This generally leads to the formation of more stable emulsions.
49

Chemical fingerprinting of naphthenic acids by comprehensive two-dimensional gas chromatography mass spectrometry at reclamation sites in the Alberta oil sands

Bowman, David Thomas January 2017 (has links)
The processing of bitumen in the Athabasca oil sands region (AOSR) produces extensive volumes of oil sands process-affected water (OSPW) and tailings, which are stored within tailings ponds and settling basins to promote the consolidation of solids and the recycling of water. Oil sands operators are actively investigating dry and wet reclamation strategies in order to reduce their inventory of tailings and return disturbed land back to its original state. An important component of the reclamation of tailings is understanding the environmental fate of naphthenic acids (NAs), which are considered the most toxic constituents of OSPW and tailings. However, since NAs exist as a complex mixture comprised of thousands of compounds from dozens of chemical classes, the characterization of NAs within environmental samples poses significant challenges to analytical chemists. This dissertation is focused on the characterization of naphthenic acids by comprehensive two-dimensional gas chromatography coupled to mass spectrometry (GC×GC/MS). GC×GC/MS offers unparalleled chromatographic separation and peak capacity and has been used in recent years to resolve individual constituents within complex mixtures, including structural isomers. Since the biodegradation and toxicity of NAs is structure-specific and can vary between structural isomers, the profiling of individual NAs by GC×GC/MS is expected to enhance the monitoring of NAs within environmental samples impacted by oil sands activity. In this thesis, GC×GC coupled with time-of-flight mass spectrometry (TOFMS) was used to structurally elucidate a number of ‘unknown’ classical and sulfur-containing naphthenic acids by interpretation of their electron ionization (EI) mass spectra and, if available, confirmed by comparison with the spectra of references standards. GC×GC/TOFMS was also utilized as a fingerprinting tool to assess the temporal and spatial variability at two reclamation sites in the AOSR: Syncrude’s Sandhill Fen reclamation site and Base Mine Lake. Lastly, a methodology was developed which coupled GC×GC with a high resolution quadrupole time-of-flight mass spectrometer (QTOFMS) for the improved profiling of NAs. GC×GC/QTOFMS is advantageous for the monitoring of NAs since it can provide useful fingerprints via isomer distributions, differentiate NAs from several chemical classes, and provide a global overview of the elemental compositions (assigned by mass accuracy) within NA mixtures. / Thesis / Doctor of Philosophy (PhD)
50

Хемијско проређивање цветова и плодова јабуке / Hemijsko proređivanje cvetova i plodova jabuke / Flower and fruit chemical thinning of apple

Milić Biserka 25 March 2016 (has links)
<p>Циљ савременог гајења јабуке је да се у засаду велике густине садње, заснованом са садницама високог квалитета које рађају већ у години садње, и савременим сортиментом који укључује и сорте склоне алтернативној родности, успоставе редовни и високи приноси који ће се кретати од 50-70 t/ha и добар квалитет плодова. Мера која је од највећег значаја за регулисање родности јесте хемијско проређивање цветова и плодова јабуке.<br />Циљ обављених истраживања је да се испита утицај хемијског проређивања цветова и плодова на заметање, квалитет плодова и родност пупољака сорти јабуке као и да се испита интеракција између минералне исхране азотом и хемијског проређивања. Резултати истраживања били би смернице за хемијско проређивање плодова у агроеколошким условима Србије, са тежњом да у скорој будућности постану део законске регулативе и припадајућих правилника за интегралну производњу, као и развој побољшаних формулација препарата за проређивање.<br />На основу испитивања проређивања цветова може се закључити да сорте јабуке бребурн и златни делишес различито реагују на примену ATS и KTS. Примена 3% ATS и 1,5% KTS код сорте бребурн изазива јаке ожеготине на листовима које могу бити узрок смањеној маси плода и слабијем образовању родних пупољака. Код сорте златни делишес ATS концентрације 3% не испољава негативно дејство на крупноћу плодова и родност пупољака, али са друге стране није ефикаснији од ATS нижих концентрација, док KTS има знатно слабије дејство.<br />Ефикасност препарата на бази NAA у смањењу заметања и приноса сорте јабуке бребурн није зависила од примењене концентрације, док је маса плода у свим варијантама била веома велика, те се за практичну примену могу препоручити ниже концентрације, до 10 &mu;l/l NAA. Сви третмани са NAA у распону концентрација од 8 до 12 &mu;l/l били су једнако ефикасни у редуковању заметања и приноса плодова, док је BA испољио слабију ефикасност у проређивању сорте јабуке камспур. Родност пупољака у третманима проређивања плодова сорти бребурн и камспур није сразмерна повећању концентрације препарата, већ у великој мери зависи од године испитивања.<br />Значајна интеракција је утврђена између фактора ђубрење и проређивање за параметре заметања плодова. Интеракција ова два фактора огледа се у томе да се у режиму интензивног ђубрења азотним ђубривима концентрација препарата на бази NAA и BA треба повећати како би се постигао задовољавајући ниво проређивања.<br />Додавање нафтенских киселина нафтилсирћетној киселини и бензиладенину значајно доприноси повећању просечне масе плода сорте јабуке златни делишес у односу на формулације без нафтенских киселина, као последица биолошке активности нафтенских киселина у смеши. Запажено је повећање чврстине плода у варијантама где је примењена формулација BA са нафтенским киселинама у односу на формулације без<br />нафтенских киселина.<br />Датум прихватања теме од стране Сената:<br />ДП<br />30.5.2013.<br />Чланови комисије:</p> / <p>Cilj savremenog gajenja jabuke je da se u zasadu velike gustine sadnje, zasnovanom sa sadnicama visokog kvaliteta koje rađaju već u godini sadnje, i savremenim sortimentom koji uključuje i sorte sklone alternativnoj rodnosti, uspostave redovni i visoki prinosi koji će se kretati od 50-70 t/ha i dobar kvalitet plodova. Mera koja je od najvećeg značaja za regulisanje rodnosti jeste hemijsko proređivanje cvetova i plodova jabuke.<br />Cilj obavljenih istraživanja je da se ispita uticaj hemijskog proređivanja cvetova i plodova na zametanje, kvalitet plodova i rodnost pupoljaka sorti jabuke kao i da se ispita interakcija između mineralne ishrane azotom i hemijskog proređivanja. Rezultati istraživanja bili bi smernice za hemijsko proređivanje plodova u agroekološkim uslovima Srbije, sa težnjom da u skoroj budućnosti postanu deo zakonske regulative i pripadajućih pravilnika za integralnu proizvodnju, kao i razvoj poboljšanih formulacija preparata za proređivanje.<br />Na osnovu ispitivanja proređivanja cvetova može se zaključiti da sorte jabuke breburn i zlatni delišes različito reaguju na primenu ATS i KTS. Primena 3% ATS i 1,5% KTS kod sorte breburn izaziva jake ožegotine na listovima koje mogu biti uzrok smanjenoj masi ploda i slabijem obrazovanju rodnih pupoljaka. Kod sorte zlatni delišes ATS koncentracije 3% ne ispoljava negativno dejstvo na krupnoću plodova i rodnost pupoljaka, ali sa druge strane nije efikasniji od ATS nižih koncentracija, dok KTS ima znatno slabije dejstvo.<br />Efikasnost preparata na bazi NAA u smanjenju zametanja i prinosa sorte jabuke breburn nije zavisila od primenjene koncentracije, dok je masa ploda u svim varijantama bila veoma velika, te se za praktičnu primenu mogu preporučiti niže koncentracije, do 10 &mu;l/l NAA. Svi tretmani sa NAA u rasponu koncentracija od 8 do 12 &mu;l/l bili su jednako efikasni u redukovanju zametanja i prinosa plodova, dok je BA ispoljio slabiju efikasnost u proređivanju sorte jabuke kamspur. Rodnost pupoljaka u tretmanima proređivanja plodova sorti breburn i kamspur nije srazmerna povećanju koncentracije preparata, već u velikoj meri zavisi od godine ispitivanja.<br />Značajna interakcija je utvrđena između faktora đubrenje i proređivanje za parametre zametanja plodova. Interakcija ova dva faktora ogleda se u tome da se u režimu intenzivnog đubrenja azotnim đubrivima koncentracija preparata na bazi NAA i BA treba povećati kako bi se postigao zadovoljavajući nivo proređivanja.<br />Dodavanje naftenskih kiselina naftilsirćetnoj kiselini i benziladeninu značajno doprinosi povećanju prosečne mase ploda sorte jabuke zlatni delišes u odnosu na formulacije bez naftenskih kiselina, kao posledica biološke aktivnosti naftenskih kiselina u smeši. Zapaženo je povećanje čvrstine ploda u varijantama gde je primenjena formulacija BA sa naftenskim kiselinama u odnosu na formulacije bez<br />naftenskih kiselina.<br />Datum prihvatanja teme od strane Senata:<br />DP<br />30.5.2013.<br />Članovi komisije:</p> / <p>The goal of modern apple growing in high density orchards, established with high-quality nursery trees which bear fruits in the year of planting, often including varieties prone to biennial bearing is to achieve high and regular yields that range from 50 to 70 t/ha with good fruit quality. Chemical thinning of flowers and fruits is a technical practice which is of great importance for crop regulation.<br />The aim of the research was to investigate the effect of chemical thinning of apple flowers and fruits on fruit set, fruit quality and bearing potential of apple buds as well as to examine the interaction between the nitrogen supply and chemical thinning treatments. The research will result with guidelines for the chemical thinning in agroecological conditions of Serbia, aiming to become a part of the legislation and associated regulations for integrated production in the near future. Testing of improved formulations of thinning chemicals will be included into expe rimental plan.<br />Considering the results derived from flower thinning experiments, it could be concluded that cv. Braeburn and Golden Delicious react differently to the application of ATS and KTS. Application of 3% ATS and 1.5% of KTS in cv Braeburn causes severe leaf burns that may be causing reduced fruit weight and a decrease in bearing potential. In cv Golden Delicious ATS applied at the concentration of 3% does not exhibit a negative effect on fruit size and bearing potential, but at the other side is not more efficient than ATS at lower concentrations, whereas KTS has a much weaker thinning effect.<br />The efficacy of NAA in reducing fruit set and yield of apple variety Braeburn is not dependent on the concentration applied, while fruit size was very large within the range of NAA concentrations. Therefore, for the practical application, concentrations lower than 10 ml/l NAA would be recommended. All treatments with NAA at concentrations ranging from 8 to 12 ml/l were equally effective in reducing fruit set and yield, while the BA exhibited decreased efficiency in thinning apple variety Camspur. Fertility of buds in Braeburn and Camspur varieties was not proportional to the increase in concentration of chemical, but to a large extent depends on the conditions of the experimental year.<br />An interaction between nitrogen supply and chemical thinning significantly affected fruit set in a way that concentration of NAA and BA for fruit thinning should be increased in order to achieve a satisfactory level of thinning at a higher level of nitrogen supply.<br />Adding of naphthenic acids to NAA and BA significantly contributed to the increase of average fruit weight of apple variety Golden Delicious compared to same chemical formulation without naphthenic acids, as a result of the biological activity of naphthenic acids in the mixture. An increase of fruit firmness was detected in thinning treatments where naphthenic acids were added to BA compared BA applied alone.</p>

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