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Investigation of the enhancement of the performance of the SIMS instruments / Recherche sur l'amélioration de la performance des instruments SIMSVerruno, Marina 06 November 2017 (has links)
Résumé : Les instruments de spectrométrie de masse à ionisation secondaire (SIMS) doivent être améliorés afin de satisfaire les exigences et tendances dans de nombreux domaines qui demandent des outils d'analyse pouvant cartographier les échantillons à la fois avec une excellente résolution et une haute sensibilité chimique, mais également avec des temps d’analyse plus court. Les objectifs de cette thèse sont : rechercher à améliorer la résolution en masse des spectromètres de masse à double focalisation en remplaçant le secteur sphérique standard par une nouvelle géométrie sphéroïde ayant de meilleures propriétés de focalisation, et d’étudier la réduction du temps d'analyse en imagerie SIMS, par la preuve de concept du système SIMS à multifaisceaux d'ions. Une comparaison des principales propriétés de focalisation du secteur sphérique, de la géométrie sphéroïde et d’une géométrie de sphéroïde hybride, a été réalisée en utilisant le logiciel SIMION. Une comparaison dans une configuration Nier-Johnson entre le secteur sphérique et le sphéroïde, a montré que le faisceau présente une rotation de 90 ° à la sortie de l'aimant nuisant à la résolution de masse dans la configuration sphéroïde. En ajoutant un élément électrostatique pouvant tourner le faisceau à 90 ° les performances du spectromètre de masse pourrait être amélioré. Toutefois, une comparaison des performances entre les secteurs sphériques et hybrides dans une configuration Mattauch-Herzog a montré que lorsque la double condition de focalisation est optimisée, une meilleure résolution de masse pourrait être obtenue avec la géométrie sphéroïde. Un système multi-faisceau ionique a été étudié pour l'analyse SIMS. La simulation à travers l’optique secondaire d'un Cameca IMS XF de neuf faisceaux a montré une transmission réussie des faisceaux, résultant en neuf points concentrés sur le détecteur plaque à canaux multiples (MCP). La preuve de concept a été achevée expérimentalement dans l'IMS 6F de Cameca, où une ouverture à trous multiples était montée dans la colonne principale, générant 9 et 16 faisceaux de tailles comprises entre 4 µm à 10 µm. Des images d'une grille AlCu ont été obtenues en balayant l'échantillon par le système de multifaisceaux d’ions. Ces résultats montrent que le système multi-faisceau d'ions est une technique possible pour l'imagerie SIMS et qu'en optimisant leur conception les multi-nano-faisceaux d'ions seront une solution permettant de réduire considérablement le temps d'analyse. / Secondary ion mass spectrometry (SIMS) instruments need to be improved in order to satisfy the demands of trends in many fields that require analytical tools that can map samples with both excellent resolution and high-sensitivity chemical information, but also with shorter time of analysis. The objectives of this thesis are: investigate the enhancement of the mass resolution of double focusing mass spectrometers by replacing the standard spherical sector with a novel spheroid geometry which has better focusing properties, and to investigate the reduction of the time of analysis in imaging SIMS by the proof-of-concept of the SIMS multi-ion- beam system.A comparison of the main focusing properties of the spherical sector, the spheroid geometry and a hybrid spheroid geometry, was made using the SIMION software. A comparison in a Nier-Johnson configuration between the spherical sector and the spheroid, showed that the beam presents a rotation of 90° at the exit of the magnet harming the mass resolution in the spheroid configuration. By adding an electrostatic element that can rotate the beam 90° the performance of the mass spectrometer could be improved. However, a comparison of the performances between the spherical and hybrid sectors simulated in a Mattauch-Herzog configuration, showed that when the double focusing condition is properly satisfied, better mass resolution could be achieved with the spheroid geometry.A multi-ion-beam system was investigated for SIMS analysis. A simulation through the secondary optics of a Cameca IMS XF showed successful transmission of nine beams through the optics resulting in nine well focussed spots on the multi channel plate (MCP) detector. The proof-of-concept was completed experimentally in the Cameca IMS 6F, where a multi-hole aperture was mounted in the primary column generating 9 and 16 beams of sizes between 4 μm to 10 μm. Images of an AlCu grid were obtained when t the multi-ion-beam system was scanned over the sample. These results showed that the multi-ion-beam system is a feasible technique for imaging SIMS and by optimizing the design multi-nano-ion-beams will be a solution for reducing drastically the time of analysis.
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Oxygen and hydrogen isotopic analysis of tourmaline by secondary ion mass spectrometryWhattam, Jessica L. 16 September 2016 (has links)
The O and H isotopic composition of minerals can provide valuable information on the source of the fluids and temperature of mineral precipitation. To obtain accurate isotopic measurements using SIMS, it is important to select chemically similar standards and samples to correct for both matrix effects and instrumental mass fractionation (IMF), collectively termed instrumental mass bias (IMB). For certain mineral groups (e.g. tourmalines), there are large variations in major element composition between species. This study uses three of these tourmaline species (schorl, dravite, and elbaite) to construct calibration curves to correct for IMB during SIMS analysis of O and H isotopes. I have applied my technique to analyses of tourmalines from the Wollaston Group, Athabasca region, Saskatchewan to test my method, and I have calculated the O and H isotopic composition of the fluids that formed these tourmalines. / October 2016
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Sporadic geometries and their universal representation groupsRichardson, Philip Jonathan January 2000 (has links)
No description available.
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Metabolic profiling and imaging of CHO cells for fusion protein productionSzula, Ewa January 2017 (has links)
Fc-fusion proteins (e.g. EPO-Fc) are the most often created fusion proteins due to their beneficial biological and pharmacological properties. The economic success of Fc-fusion proteins and other biopharmaceuticals production however, greatly depends on a robust, low-cost and highly effective protein mammalian cell extraction system . Understanding of how cells respond to a protein production environment based on metabolic profiles provides new goals for bioengineering of cell lines for best performance in biomanufacturing. Furthermore, insights on how individual cell metabolism and therefore phenotype, respond to cell microenvironment allows the underlying biological mechanisms to be explored in greater detail. This study focused on the application of mass spectrometry (MS) technologies, combining the analysis of metabolic profiles of cells extracts by GC-MS and MALDI-MS and spatial visualisation and distribution of metabolites within cells producing the fusion protein by MALDI-MSI and SIMS imaging. The analysis of external and internal metabolome profiles of cells producing the protein showed an extended effect of EPO-Fc fusion protein production on cell metabolism. The findings indicate that changes observed in EPO-Fc producing cells are related to enhanced protein and lipid synthesis highlighting that these cells are in a state of increased metabolic activity with the protein exocytosis into growth medium. Moreover, the composition of lipid bilayer of induced cells seemed to be different to non-induced cells. These findings were confirmed with the analysis of EPO-Fc induced cells using MS metabolic imaging. Multivariate analysis highlighted a number of metabolites that were significantly influenced by the protein expression when compared to control cells. The major metabolic changes in induced cells were those related to lipid metabolism. The information about metabolic changes in tetracycline-induced cells obtained from the analysis of cell populations was further supported with the analysis based on single-cell studies. Single-cell based studies also proved that investigations of individual cells provide additional insights about changes in metabolism of induced cells that can be referred to a unique, single cell and its phenotype. The analysis of CHO cells revealed a high level of heterogeneity within a cell population. Different cell phenotype and hence, metabolite content allowed for correlation between cell locations and their metabolite characteristics, specific for each type of cells. This project has successfully shown combination of bio-analytical techniques to investigate external and internal metabolome changes related to a fusion protein production in mammalian cells. Additionally, the significance of single cell approaches in metabolomics has also been highlighted, providing insights into the sub-cellular distribution of metabolites in cells producing EPO-Fc and information on the level of heterogeneity within a cell population. A multidimensional approach for metabolic profiling and future technological improvements of single-cell platforms are required to provide improved data acquisition and data analysis in order to better understand unknown processes involved in cell metabolism.
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New capabilities for molecular surface and in-depth analysis with cluster secondary ion mass spectrometryAlturaifi, Huriyyah January 2018 (has links)
Energetic polyatomic cluster beams are increasingly used in materials processing and surface analysis applications. In secondary ion mass spectrometry (SIMS) such beams have previously been utilised to investigate the chemical distribution of organic molecules (polymers, biological molecules and pharmaceuticals etc). One important application is in organic electronics, where the depth-distribution of organic components is important in the device performance. Massive gas cluster ion beams (GCIBs) have produced more successful depth-profiles for organic electronic devices that smaller projectiles including SF5+ and C60+. However, further work is needed to investigate and optimise experimental parameters to deliver the necessary SIMS performance. This study focused on molecular depth profiling of organic insulator (PMMA) and semiconductor (PTAA and TIPS-pentacene) materials, in single and bi-layered combinations, utilising cluster SIMS, using C60+ and Arn+, at different temperatures and energies. In general, at room temperature, the best depth resolution was obtained, using large Ar-GCIBs of low energy per atom (E/n ~10 eV), in comparison with the smaller Ar-GCIBs or with C60+ beams at the same total impact energy. On materials which sputtering under C60+ bombardment, ion and neutral yields were greatest due to the higher E/n, compared with GCIBs. Data from PMMA show that the sputter yield under C60 and Arn projectiles conform to the published 'universal' dependence of Y/n to E/n. Depth profiling of the semiconductor compounds were unsuccessful, using C60+ projectiles. For depth profiles using large GCIB projectiles, an increase in the secondary ion yield was observed at the interface with the silicon substrate - a phenomenon which was not observed for the smaller projectiles. In general, the most successful depth profiles (i.e. more constant molecular and fragment secondary ion yields, observed at pseudo-steady-state regions) and best depth resolutions were obtained at cryogenic temperatures - conditions under which corresponding sputtering yields and secondary ion yields were suppressed.
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Flickors och pojkars motivationsfaktorer till idrottsämnet i årskurs 7 och 9Granqvist, Ulf January 2007 (has links)
<p>Syftet med studien var att undersöka relationer mellan faktorer som motiverar elever till att delta i idrottslektioner i skolan. Dessutom studerades skillnad på motivationsfaktorer till idrottsundervisningen mellan flickor och pojkar, samt mellan elever i årskurs 7 och årskurs 9. Instrumenten som användes var TEOSQ, PCSC och SIMS. Studien genomfördes på två olika högstadieskolor på elever i årskurs 7 och 9. Totalt deltog 85 elever i studien. Resultatet visade ett positivt samband mellan resultatorienterad motivation, identifierad reglering och med positiv syn på förmågan. Vidare uppvisades ett positivt samband mellan positiv syn på förmågan, inre motivation och uppgiftsorienterad motivation. Yttre motivation var negativt relaterat med negativ syn på förmågan och positivt relaterat med amotivation. Resultatet visade även att pojkar var mer inre motiverade än flickor. Elever i årskurs 7 var mer inre motiverade och mer amotiverade än elever i årskurs 9. Vidare diskuteras det hur idrottsundervisning bäst skall vara upplagd för att få eleverna bäst motiverade framförallt jämställt mellan könen.</p>
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Flickors och pojkars motivationsfaktorer till idrottsämnet i årskurs 7 och 9Granqvist, Ulf January 2007 (has links)
Syftet med studien var att undersöka relationer mellan faktorer som motiverar elever till att delta i idrottslektioner i skolan. Dessutom studerades skillnad på motivationsfaktorer till idrottsundervisningen mellan flickor och pojkar, samt mellan elever i årskurs 7 och årskurs 9. Instrumenten som användes var TEOSQ, PCSC och SIMS. Studien genomfördes på två olika högstadieskolor på elever i årskurs 7 och 9. Totalt deltog 85 elever i studien. Resultatet visade ett positivt samband mellan resultatorienterad motivation, identifierad reglering och med positiv syn på förmågan. Vidare uppvisades ett positivt samband mellan positiv syn på förmågan, inre motivation och uppgiftsorienterad motivation. Yttre motivation var negativt relaterat med negativ syn på förmågan och positivt relaterat med amotivation. Resultatet visade även att pojkar var mer inre motiverade än flickor. Elever i årskurs 7 var mer inre motiverade och mer amotiverade än elever i årskurs 9. Vidare diskuteras det hur idrottsundervisning bäst skall vara upplagd för att få eleverna bäst motiverade framförallt jämställt mellan könen.
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Cataloging and classification manual of the L.A. Sims Memorial Library, Southeastern Louisiana College, Hammond, LouisianaMiller, Marjorie Elaine. January 1958 (has links)
Thesis (A.M.L.S.)--University of Michigan, 1958. Cf. Library literature, 1958-1960, p. 412.
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The extraction and study of interstellar grainsClarke, Alex January 2018 (has links)
The aim of this thesis is to comprehensively analyse presolar silicon carbide (SiC) grains from several primitive meteorites in order to investigate their complicated history. During their residence in the interstellar medium, presolar grains are predicted to be affected by many processes which may modify their original elemental and isotopic composition. Presolar SiC grains from three acid residues and two polished meteorite sections were analysed for their carbon, nitrogen and silicon isotope ratios with high spatial resolution, in order to compare the distribution of 14N/15N ratios compared to those found in the literature. As a result of this work, isotopic fractionation effects caused by the distortion of the electric field around the grain topography were identified. These effects have the potential to cause differential transmission of atomic and molecular secondary ions, particularly when small slits and apertures are selected during NanoSIMS analyses. The measured 14N/15N ratios of the presolar SiC grains analysed in this work match well with existing literature data, although many grains cluster at relatively low 14N/15N values. These low ratios do not appear to be the result of either terrestrial contamination or isotopic dilution, and may instead represent real differences between the SiC grain populations of different meteorites. The majority of mainstream SiC grains analysed in this work lie on a slope with a gradient of ~1.3 on a Si 3-isotope plot, in agreement with literature data. SiC grains from the JAMM and JA-MM2 acid residues appear to lie on shallower slopes, although these samples show significant scatter in the data. Neither terrestrial contamination nor isotopic dilution can explain the apparent fractionation of silicon isotopes in these samples. It is possible that these ratios may represent a difference in the Si ratios of grain populations of different meteorites, although fractionation during the sample preparation phase cannot be excluded. Ten presolar SiC grains from the KJG and JA-MM2 acid residues are comprehensively analysed for their trace element compositions using Time-of-Flight Secondary Ion Mass Spectrometry. The majority of analyses are significantly affected by the proximity of neighbouring grains, leading to high background counts which prevent the reliable determination of elemental abundances for many elements. Depth profiles of several elements are determined for two grains from the KJG residue. Each of the measured elements displays approximately homogeneous profiles through the grains, with abundances in agreement with existing literature data. The uniform depth profiles may represent formation in a stellar envelope with a stable composition, although homogenisation by secondary alteration processes cannot be ruled out.
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Analyzing Nitrogen in Silicate Glasses by Secondary Ion Mass SpectrometryJanuary 2016 (has links)
abstract: Volcanic devolatilization is one of the major processes in the global nitrogen cycle. Past studies have often estimated the magnitude of this flux using volcanic emission measurements, which are limited to currently active systems and sensitive to atmospheric contamination. A different methodological approach requires appropriate analytical parameters for nitrogen analysis in silicate glasses by secondary ion mass spectrometry (SIMS), which have not yet been established. To this end, we analyze various ion implanted basaltic and rhyolitic glasses by SIMS. We demonstrate that water content significantly affects the ion yields of 14N+ and 14N16O−, as well as the background intensity of 14N+ and 12C+. Application of implant-derived calibrations to natural samples provide the first reported concentrations of nitrogen in melt inclusions. These measurements are from samples from the Bishop Tuff in California, the Huckleberry Ridge Tuff of the Yellowstone Volcanic Center, and material from the Okaia and Oruanui eruptions in the Taupo Volcanic Center. In all studied material, we find maximum nitrogen contents of less than 45 ppm and that nitrogen concentration varies positively with CO2 concentration, which is interpreted to reflect partial degassing trend. Using the maximum measured nitrogen contents for each eruption, we find that the Bishop released >3.6 x 1013 g of nitrogen, the Huckleberry Ridge released >1.3 x 1014 g, the Okaia released >1.1 x 1011 g of nitrogen, the Oruanui released >4.7 x 1013 g of nitrogen. Simple calculations suggest that with concentrations such as these, rhyolitic eruptions may ephemerally increase the nitrogen flux to the atmosphere, but are insignificant compared to the 4 x 1021 g of nitrogen stored in the atmosphere. / Dissertation/Thesis / Masters Thesis Geological Sciences 2016
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