Dissertations / Theses on the topic 'Molecular beam mass spectrometry'
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Secco, Andrea. "Use of the molecular beam mass spectrometry to study the low-temperature combustion chemistry." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2017. http://amslaurea.unibo.it/14506/.
Osaka, J., Senthil M. Kumar, H. Toyoda, T. Ishijima, H. Sugai, and T. Mizutani. "Role of atomic nitrogen during GaN growth by plasma-assisted molecular beam epitaxy revealed by appearance mass spectrometry." American Institute of Physics, 2007. http://hdl.handle.net/2237/8775.
Tsang, Roland S. "Characterisation of the gas-phase environment in a hot filament diamond chemical vapour deposition chamber using molecular beam mass spectrometry." Thesis, University of Bristol, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.389238.
Leeds, Stuart M. "Characterisation of the gas-phase environment in a microwave plasma enhanced diamond chemical vapour deposition reactor using molecular beam mass spectrometry." Thesis, University of Bristol, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.297978.
Fox, Oliver James Louis. "Deposition of nanocrystalline diamond films by MW plasma CVD & gas-phase diagnostics using in-situ molecular-beam mass spectrometry and emission spectroscopy." Thesis, University of Bristol, 2011. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.544422.
Crichton, Edward. "Construction of a molecular beam mass spectrometer for in-situ probing of a diamond chemical vapour deposition environment." Thesis, University of Bristol, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.443689.
Ellerweg, Dirk [Verfasser], Achim von [Gutachter] Keudell, and Peter [Gutachter] Awakowicz. "Reaction chemistry in oxygen or hexamethyldisiloxane containing noble gas microplasma jets : a quantitative molecular beam mass spectrometry study / Dirk Ellerweg ; Gutachter: Achim von Keudell, Peter Awakowicz ; Fakultät für Physik und Astronomie." Bochum : Ruhr-Universität Bochum, 2012. http://d-nb.info/1209358409/34.
Fischer, Andreas [Verfasser], Wolfram [Akademischer Betreuer] Sander, and Martina [Akademischer Betreuer] Havenith. "Development of a molecular beam mass spectrometer and a supersonic jet expansion pyrolyzer for the characterization of reactive organic intermediates / Andreas Fischer. Gutachter: Wolfram Sander ; Martina Havenith." Bochum : Ruhr-Universität Bochum, 2016. http://d-nb.info/1089006306/34.
Moreira, Ana Sofia Pereira. "Study of modifications induced by thermal and oxidative treatment in oligo and polysaccharides of coffee by mass spectrometry." Doctoral thesis, Universidade de Aveiro, 2016. http://hdl.handle.net/10773/17074.
Os polissacarídeos são os componentes maioritários dos grãos de café verde e torrado e da bebida de café. Os mais abundantes são as galactomananas, seguindo-se as arabinogalactanas. Durante o processo de torra, as galactomananas e arabinogalactanas sofrem modificações estruturais, as quais estão longe de estar completamente elucidadas devido à sua diversidade e à complexidade estrutural dos compostos formados. Durante o processo de torra, as galactomananas e arabinogalactanas reagem com proteínas, ácidos clorogénicos e sacarose, originando compostos castanhos de alto peso molecular contendo nitrogénio, designados de melanoidinas. As melanoidinas do café apresentam diversas atividades biológicas e efeitos benéficos para a saúde. No entanto, a sua estrutura exata e os mecanismos envolvidos na sua formação permanecem desconhecidos, bem como a relação estrutura-atividade biológica. A utilização de sistemas modelo e a análise por espectrometria de massa permitem obter uma visão global e, simultaneamente, detalhada das modificações estruturais nos polissacarídeos do café promovidas pela torra, contribuindo para a elucidação das estruturas e mecanismos de formação das melanoidinas. Com base nesta tese, oligossacarídeos estruturalmente relacionados com a cadeia principal das galactomananas, (β1→4)-Dmanotriose (Man3), e as cadeias laterais das arabinogalactanas, (α1→5)-Larabinotriose (Ara3), isoladamente ou em misturas com ácido 5-Ocafeoilquínico (5-CQA), o ácido clorogénico mais abundante nos grãos de café verde, e péptidos compostos por tirosina e leucina, usados como modelos das proteínas, foram sujeitos a tratamento térmico a seco, mimetizando o processo de torra. A oxidação induzida por radicais hidroxilo (HO•) foi também estudada, uma vez que estes radicais parecem estar envolvidos na modificação dos polissacarídeos durante a torra. A identificação das modificações estruturais induzidas por tratamento térmico e oxidativo dos compostos modelo foi feita por estratégias analíticas baseadas principalmente em espectrometria de massa, mas também em cromatografia líquida. A cromatografia de gás foi usada na análise de açúcares neutros e ligações glicosídicas. Para validar as conclusões obtidas com os compostos modelo, foram também analisadas amostras de polissacarídeos do café obtidas a partir de resíduo de café e café instantâneo. Os resultados obtidos a partir dos oligossacarídeos modelo quando submetidos a tratamento térmico (seco), assim como à oxidação induzida por HO• (em solução), indicam a ocorrência de despolimerização, o que está de acordo com estudos anteriores que reportam a despolimerização das galactomananas e arabinogalactanas do café durante a torra. Foram ainda identificados outros compostos resultantes da quebra do anel de açúcares formados durante o tratamento térmico e oxidativo da Ara3. Por outro lado, o tratamento térmico a seco dos oligossacarídeos modelo (individualmente ou quando misturados) promoveu a formação de oligossacarídeos com um maior grau de polimerização, e também polissacarídeos com novos tipos de ligações glicosídicas, evidenciando a ocorrência de polimerização através reações de transglicosilação não enzimática induzidas por tratamento térmico a seco. As reações de transglicosilação induzidas por tratamento térmico a seco podem ocorrer entre resíduos de açúcares provenientes da mesma origem, mas também de origens diferentes com formação de estruturas híbridas, contendo arabinose e manose como observado nos casos dos compostos modelo usados. Os resultados obtidos a partir de amostras do resíduo de café e de café instantâneo sugerem a presença de polissacarídeos híbridos nestas amostras de café processado, corroborando a ocorrência de transglicosilação durante o processo de torra. Além disso, o estudo de misturas contendo diferentes proporções de cada oligossacarídeo modelo, mimetizando regiões do grão de café com composição distinta em polissacarídeos, sujeitos a diferentes períodos de tratamento térmico, permitiu inferir que diferentes estruturas híbridas e não híbridas podem ser formadas a partir das arabinogalactanas e galactomananas, dependendo da sua distribuição nas paredes celulares do grão e das condições de torra. Estes resultados podem explicar a heterogeneidade de estruturas de melanoidinas formadas durante a torra do café. Os resultados obtidos a partir de misturas modelo contendo um oligossacarídeo (Ara3 ou Man3) e 5-CQA sujeitas a tratamento térmico a seco, assim como de amostras provenientes do resíduo de café, mostraram a formação de compostos híbridos compostos por moléculas de CQA ligadas covalentemente a um número variável de resíduos de açúcar. Além disso, os resultados obtidos a partir da mistura contendo Man3 e 5-CQA mostraram que o CQA atua como catalisador das reações de transglicosilação. Por outro lado, nas misturas modelo contendo um péptido, mesmo contendo também 5-CQA e sujeitas ao mesmo tratamento, observou-se uma diminuição na extensão das reações transglicosilação. Este resultado pode explicar a baixa extensão das reações de transglicosilação não enzimáticas durante a torra nas regiões do grão de café mais ricas em proteínas, apesar dos polissacarídeos serem os componentes maioritários dos grãos de café. A diminuição das reações de transglicosilação na presença de péptidos/proteínas pode dever-se ao facto de os resíduos de açúcares redutores reagirem preferencialmente com os grupos amina de péptidos/proteínas por reação de Maillard, diminuindo o número de resíduos de açúcares redutores disponíveis para as reações de transglicosilação. Além dos compostos já descritos, uma diversidade de outros compostos foram formados a partir dos sistemas modelo, nomeadamente derivados de desidratação formados durante o tratamento térmico a seco. Em conclusão, a tipificação das modificações estruturais promovidas pela torra nos polissacarídeos do café abre o caminho para a compreensão dos mecanismos de formação das melanoidinas e da relação estrutura-atividade destes compostos.
Polysaccharides are the major components of green and roasted coffee beans, and coffee brew. The most abundant ones are galactomannans, followed by arabinogalactans. During the roasting process, galactomannans and arabinogalactans undergo structural modifications that are far to be completely elucidated due to their diversity and complexity of the compounds formed. During the roasting process, galactomannans and arabinogalactans react with proteins, chlorogenic acids, and sucrose, originating high molecular weight brown compounds containing nitrogen, known as melanoidins. Several biological activities and beneficial health effects have been attributed to coffee melanoidins. However, their exact structures and the mechanisms involved in their formation remain unknown, as well as the structure-biological activity relationship. The use of model systems and mass spectrometry analysis allow to obtain an overall view and, simultaneously, detailed, of the structural modifications in coffee polysaccharides promoted by roasting, contributing to the elucidation of the structures and formation mechanisms of melanoidins. Based on this thesis, oligosaccharides structurally related to the backbone of galactomannans, (β1→4)-D-mannotriose, and the side chains of arabinogalactans, (α1→5)-Larabinotriose, alone or in mixtures with 5-O-caffeoylquinic acid, the most abundant chlorogenic acid in green coffee beans, and dipeptides composed by tyrosine and leucine, used as models of proteins, were submitted to dry thermal treatments, mimicking the coffee roasting process. The oxidation induced by hydroxyl radicals (HO•) was also studied, since these radicals seem to be involved in the modification of the polysaccharides during roasting. The identification of the structural modifications induced by thermal and oxidative treatment of the model compounds was performed mostly by mass spectrometry-based analytical strategies, but also using liquid chromatography. Gas chromatography was used in the analysis of neutral sugars and glycosidic linkages. To validate the conclusions achieved with the model compounds, coffee polysaccharide samples obtained from spent coffee grounds and instant coffee were also analysed. The results obtained from the model oligosaccharides when submitted to thermal treatment (dry) or oxidation induced by HO• (in solution) indicate the occurrence of depolymerization, which is in line with previous studies reporting the depolymerization of coffee galactomannans and arabinogalactans during roasting. Compounds resulting from sugar ring cleavage were also formed during thermal treatment and oxidative treatment of Ara3. On the other hand, the dry thermal treatment of the model oligosaccharides (alone or when mixed) promoted the formation of oligosaccharides with a higher degree of polymerization, and also polysaccharides with new type of glycosidic linkages, evidencing the occurrence of polymerization via non-enzymatic transglycosylation reactions induced by dry thermal treatment. The transglycosylation reactions induced by dry thermal treatment can occur between sugar residues from the same origin, but also of different origins, with formation of hybrid structures, containing arabinose and mannose in the case of the model compounds used. The results obtained from spent coffee grounds and instant coffee samples suggest the presence of hybrid polysaccharides in these processed coffee samples, corroborating the occurrence of transglycosylation during the roasting process. Furthermore, the study of mixtures containing different proportions of each model oligosaccharide, mimicking coffee bean regions with distinct polysaccharide composition, subjected to different periods of thermal treatment, allowed to infer that different hybrid and non-hybrid structures may be formed from arabinogalactans and galactomannans, depending on their distribution in the bean cell walls and on roasting conditions. These results may explain the heterogeneity of melanoidins structures formed during coffee roasting. The results obtained from model mixtures containing an oligosaccharide (Ara3 or Man3) and 5-CQA and subjected to dry thermal treatment, as well as samples derived from spent coffee grounds, showed the formation of hybrid compounds composed by CQA molecules covalently linked to a variable number of sugar residues. Moreover, the results obtained from the mixture containing Man3 and 5-CQA showed that CQA acts as catalyst of transglycosylation reactions. On the other hand, in the model mixtures containing a peptide, even if containing 5-CQA and subjected to the same treatment, it was observed a decrease in the extent of transglycosylation reactions. This outcome can explain the low extent of non-enzymatic transglycosylation reactions during roasting in coffee bean regions enriched in proteins, although polysaccharides are the major components of the coffee beans. The decrease of transglycosylation reactions in the presence of peptides/proteins can be related with the preferential reactivity of reducing residues with the amino groups of peptides/proteins by Maillard reaction, decreasing the number of reducing residues available to be directly involved in the transglycosylation reactions. In addition to the compounds already described, a diversity of other compounds were formed from model systems, namely dehydrated derivatives formed during dry thermal treatment. In conclusion, the identification of the structural modifications in coffee polysaccharides promoted by roasting pave the way to the understanding of the mechanisms of formation of melanoidins and structure-activity relationship of these compounds.
Stenby, Ejsing Christer. "Molecular characterization of the lipidome by mass spectrometry." Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2007. http://nbn-resolving.de/urn:nbn:de:swb:14-1172770038324-91461.
Stenby, Ejsing Christer. "Molecular characterization of the lipidome by mass spectrometry." Doctoral thesis, Technische Universität Dresden, 2006. https://tud.qucosa.de/id/qucosa%3A25015.
DONG, YONGHUI. "Mass spectrometry imaging: looking fruits at molecular level." Doctoral thesis, country:IT, 2014. http://hdl.handle.net/10449/24270.
Dong, Yonghui. "Mass Spectrometry Imaging: Looking Fruits at Molecular Level." Doctoral thesis, Università degli studi di Trento, 2014. https://hdl.handle.net/11572/368984.
Dong, Yonghui. "Mass Spectrometry Imaging: Looking Fruits at Molecular Level." Doctoral thesis, University of Trento, 2014. http://eprints-phd.biblio.unitn.it/1286/1/Thesis_Yonghui_Dong.pdf.
Fornai, L. "Molecular Imaging of the heart by mass spectrometry." Doctoral thesis, Università degli studi di Padova, 2011. http://hdl.handle.net/11577/3421675.
Introduzione Le malattie cardiovascolari rappresentano nel mondo la prima causa di morte, contando 17.1 milioni di morti ogni anno. Attualmente i meccanismi fisiopatologici alla base delle patologie sono in larga parte ancora sconosciuti. Capire la natura dei complessi processi biologici in atto sia nel miocardio cardiaco sano che malato richiede l’identificazione e la localizzazione degli stessi elementi molecolari coinvolti. METODO Utilizzando tecniche complementari di spettrometria di massa d’immagine (SMI) quali la spettrometria di massa a ioni secondari (Secondary Ion Mass Spectrometry, SIMS) e la spettrometria di massa a desorbimento /ionizzazione laser assistita da matrice (Matrix-assisted laser desorption/ionization, MALDI) abbiamo analizzato le principali componenti del cuore del ratto: il pericardio, il miocardio, l’endocardio, le valvole e i grandi vasi al fine di studiare ed identificare l’originale distribuzione di atomi, lipidi, peptici e proteine nel tessuto cardiaco normale. Quaranta sezioni di tessuto cardiaco sono state acquisite e ricostruite ottenendo un database tridimensionale. RISULTATI L’analisi della superficie delle sezione di tessuto cardiaco ha generato molteplici ioni secondari con un intervallo di massa che raggiunge i 1500 m/z. Utilizzando la modalita’ negativa abbiamo identificato il colesterolo e gli ioni relativi ad esso che mostrato un alta intensita’ in entrambi gli atri, l’aorta, l’arteria polmonare e pericardio. La colina corrispondente a 105 m/z di massa molecolare risulta essere localizzata in entrambi gli atri, aorta, arteria polmonare, valvole atrioventricolari e valvole semilunari ma non risulta essere presente sulla superficie ventricolare. Sono state identificate molecole appartenenti al diacilglicerolo come acido Oleico, Linoleico [OL]+ corrispondenti alla massa molecolare di 602 m/z e [OO]+ (Oleico,Oleico) con massa molecolare di 604 m/z. Le immagini ottenute dalla ricostruzione tridimensionale mostrano una specifica localizzazione complementare tra il sodio, il potassio e gli ioni con massa molecolare di 145 m/z e 667 m/z. Il sodio e’maggiormente localizzato nelle regioni cardiache corrispondenti agli atri, mentre il potassio e’ maggiormente localizzato nelle regioni corrispondenti alla superficie ventricolari. Lo ione con massa molecolare di 667 m/z e’ localizzato con molta precisione all’interno della parete dell’aorta e lo ione con massa molecolare di 145 m/z e’ localizzato a livello delle regioni atriali. CONCLUSIONI Al fine di promuovere un’ulteriore ricerca in patologia cardiovascolare, riportiamo l’identificazione delle caratteristiche molecole che mappano l’organizzazione spaziale delle strutture cardiache del cuore del ratto. Una serie di immagini ottenute da sezioni successive del cuore potrebbero inizialmente essere utilizzate come un atlante molecolare e similmente, ad un atlante basato sulle immagini ottiche, essere ampiamente utilizzato come referente sia dal punto di vista fisiologico che anatomico. L’aiuto apportato da questo progetto e’ l’ottimizzazione dei dati ottenuti dall’analisi SIMS e lo sviluppo della tecnica per la ricostruzione tridimensionale al fine di investigare e visualizzare le differenti molecole localizzate nelle strutture del cuore di ratto. I risultati qui riportati rappresentano la prima ricostruzione tridimensionale ottenuta con immagini SIMS, del cuore di ratto.
Boiteau, Rene M. "Molecular determination of marine iron ligands by mass spectrometry." Thesis, Massachusetts Institute of Technology, 2016. http://hdl.handle.net/1721.1/103259.
Page 231 blank. Cataloged from PDF version of thesis.
Includes bibliographical references.
Marine microbes produce a wide variety of metal binding organic ligands that regulate the solubility and availability of biologically important metals such as iron, copper, cobalt, and zinc. In marine environments where the availability of iron limits microbial growth and carbon fixation rates, the ability to access organically bound iron confers a competitive advantage. Thus, the compounds that microbes produced to acquire iron play an important role in biogeochemical carbon and metal cycling. However, the source, abundance, and identity of these compounds are poorly understood. To investigate these processes, sensitive methodologies were developed to gain a compound-specific window into marine iron speciation by combining trace metal clean sample collection and chromatography with inductively coupled plasma mass spectrometry (LCICPMS) and electrospray ionization mass spectrometry (LC-ESIMS). Coupled with isotope pattern assisted search algorithms, these tools provide a means to quantify and isolate specific iron binding ligands from seawater and marine cultures, identify them based on their mass and fragmentation spectra, and investigate their metal binding kinetics. Using these techniques, we investigated the distribution and diversity of marine iron binding ligands. In cultures, LC-ICPMS-ESIMS was used to identify new members of siderophore classes produced by marine cyanobacteria and heterotrophic bacteria, including synechobactins and marinobactins. Applications to natural seawater samples from the Pacific Ocean revealed a wide diversity of both known and novel metal compounds that are linked to specific nutrient regimes. Ferrioxamines B, E, and G were identified in productive coastal waters near California and Peru, in oligotrophic waters of the North and South Pacific Gyre, and in association with zooplankton grazers. Siderophore concentrations were up to five-fold higher in iron-deficient offshore waters (9pM) and were dominated by amphibactins, amphiphilic siderophores that partition into cell membranes. Furthermore, synechobactins were detected within nepheloid layers along the continental shelf. These siderophores reflect adaptations that impact dissolved iron bioavailability and thus have important consequences for marine ecosystem community structures and primary productivity. The ability to map and characterize these compounds has opened new opportunities to better understand mechanisms that link metals with the microbes that use them.
by Rene M. Boiteau.
Ph. D.
Kim, Yong-Dal. "Accelerator Mass Spectrometry Studies of Highly Charged Molecular Ions." Thesis, University of North Texas, 1994. https://digital.library.unt.edu/ark:/67531/metadc279004/.
Richardson, Jerry Christopher. "Transport, vaporization, and ionization in particle beam liquid chromatography/mass spectrometry interfacing." Thesis, Georgia Institute of Technology, 1993. http://hdl.handle.net/1853/30974.
Baxter, Christina M. "Development of a low-flow particle beam interface for enviromental mass spectrometry." Diss., Georgia Institute of Technology, 2000. http://hdl.handle.net/1853/30656.
Watson, R. Craig Jr. "Laser-Ionization Time-of-Flight Mass Spectrometry of High Molecular Mass Inorganic Complexes." Thesis, Virginia Tech, 1997. http://hdl.handle.net/10919/35554.
This thesis describes the characterization of a LI-TOF-MS instrument and confirmation of theoretical time-of-flight mass-separation principles. Several test cases demonstrate the instrument's proper operation and calibration for a wide mass range of analytes. Mass spectral results of three organometallic compounds: i. [Ir(dpp)2Cl2](PF6), ii. {[(bpy)2Ru(dpp)]2IrCl2}(PF6)5, and iii. {[(bpy)2Ru(dpp)]2RuCl2}(PF6)5 under a variety of laser ionization and sample preparation conditions are compared. A complete structural characterization of the monometallic complex, [Ir(dpp)2Cl2](PF6), is presented. The two trimetallic analytes fragmented easily, but significant components of the molecules are successfully identified. After optimizing the ionization and analytical procedure, LI-TOF-MS proved useful in the analysis of high molecular mass metal complexes.
Master of Science
Kuzema, P. O., M. Ya Dovzhyk, and O. S. Kuzema. "Main Stages of Development and Recent Advances of Mass Spectrometry." Thesis, Sumy State University, 2015. http://essuir.sumdu.edu.ua/handle/123456789/42625.
Harris, William Eric. "Characterization of transport and vaporization processes in particle beam liquid chromatography/mass spectrometry." Diss., Georgia Institute of Technology, 1991. http://hdl.handle.net/1853/30564.
Burdette, Diana Marguerite. "Interfacing packed column supercritical fluid chromatography with mass spectrometry using the particle beam interfaceBurdette." Thesis, Georgia Institute of Technology, 1995. http://hdl.handle.net/1853/27555.
Undin, Torgny. "Characterization of Molecular Adsorption Using Liquid Chromatography and Mass Spectrometry." Doctoral thesis, Uppsala universitet, Analytisk kemi, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-249003.
Gallimore, Peter James. "Molecular characterisation of organic aerosols using soft ionisation mass spectrometry." Thesis, University of Cambridge, 2015. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.709386.
Wright, Scott Jason. "In situ molecular analysis using two-step laser mass spectrometry." Thesis, University of Edinburgh, 1997. http://hdl.handle.net/1842/11612.
Sookdeo, Adam. "The Determination of 210Pb by Accelerator Mass Spectrometry." Thesis, Université d'Ottawa / University of Ottawa, 2015. http://hdl.handle.net/10393/32010.
Rennie, Emma E. "Decay mechanisms of photoexcited molecular ions." Thesis, Heriot-Watt University, 1997. http://hdl.handle.net/10399/658.
Ekroos, Kim. "Characterization of Molecular Glycerophospholipids by Quadrupole Time-of-Flight Mass Spectrometry." Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2003. http://nbn-resolving.de/urn:nbn:de:swb:14-1071755489156-08653.
Tito, Mark Anthony. "Assembly of macromolecular complexes examined by electrospray ionisation mass spectrometry." Thesis, University of Oxford, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.365340.
Rabus, Jordan. "Mass Spectrometry of Carbohydrates by Experimental and Theoretical Methods." Ohio University / OhioLINK, 2021. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1628688928273698.
Dmitriev, Artëm. "Kinetic study of ester biofuels in flames." Electronic Thesis or Diss., Université de Lorraine, 2020. http://www.theses.fr/2020LORR0238.
Global progress all over the world requires a variety of clean energy sources. Liquid ester-based biofuels seem to be very effective in this context since they are easy to use in modern vehicles, they can be produced from a variety of renewable resources, and they provide environmentally friendly combustion characteristics. In this regard, fatty acid ethyl esters (FAEEs) are considered as a promising class of biofuels. The main goal of this thesis was to develop an updated chemical kinetic mechanism of combustion of light FAEEs up to ethyl pentanoate and validate it against the new experimental data on chemical speciation in low and atmospheric pressure premixed laminar flames. The flames fueled by three FAEEs, ethyl acetate, ethyl butanoate and ethyl pentanoate, were investigated by means of molecular-beam mass-spectrometry and gas-chromatography. More than 40 stable and intermediate species including radicals were detected and quantified in the flames. A comprehensive analysis of the developed mechanism was performed. The thesis consists of 3 chapters. In the first chapter a review of literature is presented. The most important experimental and theoretic studies on FAEEs are discussed. The second chapter presents an overview of experimental and simulation methods used in the work. Details on the mechanism development are also provided in this part. The last chapter present experimental and modeling results on the esters studied in comparison with the literature kinetic mechanisms
Théberge, Roger. "An investigation of the beam-induced dehalogenation process in liquid secondary ion mass spectrometry." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/nq26743.pdf.
White, John. "The determination of trace organic micro-pollutants by particle beam liquid chromatography mass spectrometry." Thesis, Sheffield Hallam University, 2000. http://shura.shu.ac.uk/20526/.
Li, Libing. "Strategies for secondary ion yield enhancements in focused ion beam secondary ion mass spectrometry." Thesis, Imperial College London, 2010. http://hdl.handle.net/10044/1/11806.
Cerruti, Laura F. "Evaluation of a particle beam interface for LC/MS." Thesis, Virginia Tech, 1989. http://hdl.handle.net/10919/44624.
The performance of a Hewlett Packard Particle Beam LC/MS interface is evaluated using EPA appendix VIII and IX compounds. The behavior of these priority pollutants in the interface could determine its feasibility as a future EPA certified technique.
The evaluation process consists of studies to determine minimum detectable quantities (MDQ), linear response, and band broadening contributions. The MDQ's of the analytes in electron impact and chemical ionization modes are extrapolated from experimental signal to noise data. The linearity study involves ten compounds analyzed at five different concentrations. The response factors (RF) are calculated and discussed. The study concerning the band broadening contributions of the interface involves four independent variables (helium flow, desolvation chamber temperature, source temperature, and 96 methanol) and their effects on peak width. A Boxâ Behnken experimental design is used and described. Response surfaces are generated from the best fit equation describing the data.
Master of Science
Perumal, Karthick. "Epitaxial growth of Ge-Sb-Te based phase change materials." Doctoral thesis, Humboldt-Universität zu Berlin, Mathematisch-Naturwissenschaftliche Fakultät I, 2013. http://dx.doi.org/10.18452/16815.
Ge-Sb-Te based phase change materials are considered as a prime candidate for optical and electrical data storage applications. With the application of an optical or electrical pulse, they can be reversibly switched between amorphous and crystalline state, thereby exhibiting large optical and electrical contrast between the two phases, which are then stored as information in the form of binary digits. Single crystalline growth is interesting from both the academic and industrial perspective, as ordered Ge-Sb-Te based metamaterials are known to exhibit switching at reduced energies. The present study deals with the epitaxial growth and analysis of Ge-Sb-Te based thin films. The first part of the thesis deals with the epitaxial growth of GeTe. Thin films of GeTe were grown on highly mismatched Si(111) and (001) substrates. On both the substrate orientations the film grows along [111] direction with an amorphous-to-crystalline transition observed during the initial stages of growth. The amorphous-to-crystalline transition was studied in-vivo using azimuthal reflection high-energy electron diffraction scans and grazing incidence x-ray diffraction. In the second part of the thesis epitaxy and characterization of Sb2Te3 thin films are presented. The third part of the thesis deals with the epitaxy of ternary Ge-Sb-Te alloys. The composition of the films are shown to be highly dependent on growth temperatures and vary along the pseudobinary line from Sb2Te3 to GeTe with increase in growth temperatures. A line-of-sight quadrupole mass spectrometer was used to reliably control the GeSbTe growth temperature. Growth was performed at different Ge, Sb, Te fluxes to study the compositional variation of the films. Incommensurate peaks are observed along the [111] direction by x-ray diffraction. The possibility of superstructural vacancy ordering along the [111] direction is discussed.
De, Brabandere Heidi. "Organic Phosphorus Compounds in Aquatic Sediments : Towards Molecular Identification with Mass Spectrometry." Doctoral thesis, Uppsala universitet, Institutionen för fysikalisk och analytisk kemi, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-9319.
Bennet, Francesca Chemical Sciences & Engineering Faculty of Engineering UNSW. "Studying polymer degradation at a molecular level via soft ionisation mass spectrometry." Publisher:University of New South Wales, 2009. http://handle.unsw.edu.au/1959.4/43692.
Arnberg, Elise. "Investigation of molecular probes for pH determination with electrospray ionization mass spectrometry." Thesis, Uppsala universitet, Institutionen för kemi - BMC, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-381962.
Carr, R. H. "High sensitivity stable carbon isotope ratio mass spectrometry : instrument development application." Thesis, University of Cambridge, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.303835.
Blair, Sheryl McCutcheon. "Evaluation of metal complexation in molecular recognition using quadrupole ion trap mass spectrometry /." Digital version accessible at:, 2000. http://wwwlib.umi.com/cr/utexas/main.
Chaput, Dale. "Mass Spectrometry-Based Investigation of APP-Dependent Mechanisms in Neurodegeneration." Scholar Commons, 2015. http://scholarcommons.usf.edu/etd/5921.
Sui, Ping. "Molecular Signatures of Neuropathic Pain : Revealing Pain-Related Signaling Processes in Spinal Cord Using Mass Spectrometric Methodologies." Doctoral thesis, Uppsala universitet, Analytisk kemi, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-251334.
Flowers, Antwoine. "Mass-spectrometry Based Proteomics of Age-related Changes in Murine Microglia." Scholar Commons, 2017. http://scholarcommons.usf.edu/etd/6840.
Wood, Erin. "Analysis of high molecular weight organic compounds in ambient aerosols using mass spectrometry." Diss., Connect to online resource, 2005. http://wwwlib.umi.com/cr/colorado/fullcit?p1427784.
Lopez, Sanchez Susana. "Identification of high molecular weight polycyclic aromatic hydrocarbons by chromatography and mass spectrometry." Diss., Georgia Institute of Technology, 1985. http://hdl.handle.net/1853/27115.
Finch, Jeffrey William. "Selective mass spectrometry by single-photon ionization from a molecular hydrogen laser source." Diss., The University of Arizona, 1992. http://hdl.handle.net/10150/185895.
PIGA, ISABELLA. "Proteomics tools and mass spectrometry imaging techniques for the molecular characterization of pancreas." Doctoral thesis, Università di Siena, 2016. http://hdl.handle.net/11365/1007351.
Tung-Nguyen, Ngoc Hoang. "Analytical method development for determination of methylmercury low molecular mass thiol complexes by liquid chromatography tandem mass spectrometry." Thesis, Umeå universitet, Kemiska institutionen, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-122071.