Impacts of high kinetic energy massive gold clusters (~ 500 keV Au400+4) exhibit significantly enhanced secondary ion yields relative to traditional atomic or polyatomic primary ions (e.g. Au3 and C60). The one-of-a-kind instrument used to generate these hypervelocity nanoparticles (~2 nm diameter, ~30 km/s) and monitor emissions from their impacts (SIMS) is described in detail for the first time. The projectile range of 520 keV Au400+4 is measured to be ~20 nm in amorphous carbon and projectile disintegration is observed at the exit of carbon foils as thin as 5 nm. These experiments were performed by monitoring carbon cluster ions emitted from both sides of a foil impacted by the projectile. Surprisingly, clusters emitted in the forward direction are larger than those emitted backward. The composition of the mass spectra is shown to depend on both the thickness of the foil and the size of the projectile. Secondary ion yields for a variety of materials including peptides, lipids, drugs, polymers, inorganic salts, and various small molecules have been measured and molecular ion yields for many of these species exceed unity. Multiplicity measurements show that up to seven molecular ions of leucine-enkephalin (YGGFL) can be detected from the impact of a single projectile. SI yields measured with ~500 keV Au400+4 are generally one to two orders of magnitude greater than those obtained with 130 keV Au3+ and 50 keV C60+ projectiles. The high molecular ion yields observed suggest the internal energies of ions emitted from massive cluster impacts are relatively low. In order to address this hypothesis, a novel method for measuring secondary ion internal energies was developed using a series of benzylpyridinium salts. Using this method, the internal energies were measured to be ~0.19 eV/atom, which is a factor of five less than that seen in atomic-SIMS. Sample metallization is shown to be ineffective for further increasing secondary ion yields with Au400, despite observations from previous molecular dynamic simulations. Coincidence mass spectrometry is applied to nanometric chemical segregations found on samples coated with thin layers of gold and silver. It is possible to measure the surface coverages of the metallic and underlying organic layers using mass spectrometry in a non-imaging mode.

The large amount of turquoise artifacts recovered from archaeological sites in the American Southwest and Mesoamerica suggests that turquoise was an important commodity in pre-Columbian trade networks. However, the spatial and temporal patterns of turquoise exchange networks and the provenance regions of the turquoise in the southwestern United States and Mesoamerica are poorly understood. Turquoise (CuAl6(PO4)4(OH)8•4(H2O)) is a supergene mineral that forms from meteoric water along fractures that are often associated with copper porphyry deposits. This copper-rich mineral can range in color and chemistry within a single sample or deposit. The ability to identify the turquoise resource areas of turquoise artifacts using the stable isotopes of hydrogen (2H/1H) and copper (65Cu/63Cu) has overcome many of the limitations of trace element analyses of complex minerals such as turquoise. The geography and geology of turquoise deposits dictate the isotopic composition of turquoise. Employing the Secondary Ion Mass Spectrometry (SIMS) technique to measure the hydrogen and copper stable isotope ratios in turquoise samples, a comparative reference database consisting of 876 analyses from 21 turquoise resource areas in the western United States was established. Sixty-two turquoise artifacts recovered from Aztec Ruin, Salmon Ruin, and nine sites in Chaco Canyon were analyzed and their isotopic signatures were compared to the reference database identifying the turquoise resource areas of 35 artifacts. These results were compared to pre-existing models of trade and exchange in the American Southwest and models that explain the complex culture history of the inhabitants of these sites. The results showed that turquoise was obtained from several different turquoise provenance regions across the western United States and there are notable differences in the turquoise procurement patterns between the three major great houses and between Pueblo Bonito and the small sites within Chaco Canyon. The results from this study improved the understanding of turquoise trade and relationships among the occupants of important Ancestral Puebloan sites in northwestern New Mexico. The development of the turquoise comparative reference database established the foundation of future research for reconstruction of ancient turquoise trade networks and investigation of turquoise procurement strategies in the American Southwest and Mesoamerica.

The large amount of turquoise artifacts recovered from archaeological sites in the American Southwest and Mesoamerica suggests that turquoise was an important commodity in pre-Columbian trade networks. However, the spatial and temporal patterns of turquoise exchange networks and the provenance regions of the turquoise in the southwestern United States and Mesoamerica are poorly understood. Turquoise (CuAl6(PO4)4(OH)8•4(H2O)) is a supergene mineral that forms from meteoric water along fractures that are often associated with copper porphyry deposits. This copper-rich mineral can range in color and chemistry within a single sample or deposit. The ability to identify the turquoise resource areas of turquoise artifacts using the stable isotopes of hydrogen (2H/1H) and copper (65Cu/63Cu) has overcome many of the limitations of trace element analyses of complex minerals such as turquoise. The geography and geology of turquoise deposits dictate the isotopic composition of turquoise. Employing the Secondary Ion Mass Spectrometry (SIMS) technique to measure the hydrogen and copper stable isotope ratios in turquoise samples, a comparative reference database consisting of 876 analyses from 21 turquoise resource areas in the western United States was established. Sixty-two turquoise artifacts recovered from Aztec Ruin, Salmon Ruin, and nine sites in Chaco Canyon were analyzed and their isotopic signatures were compared to the reference database identifying the turquoise resource areas of 35 artifacts. These results were compared to pre-existing models of trade and exchange in the American Southwest and models that explain the complex culture history of the inhabitants of these sites. The results showed that turquoise was obtained from several different turquoise provenance regions across the western United States and there are notable differences in the turquoise procurement patterns between the three major great houses and between Pueblo Bonito and the small sites within Chaco Canyon. The results from this study improved the understanding of turquoise trade and relationships among the occupants of important Ancestral Puebloan sites in northwestern New Mexico. The development of the turquoise comparative reference database established the foundation of future research for reconstruction of ancient turquoise trade networks and investigation of turquoise procurement strategies in the American Southwest and Mesoamerica.

Submitted by MILENA GALHARDO BORGUINI (mgborguini@hotmail.com) on 2018-09-04T04:00:23Z No. of bitstreams: 1 TESE DR MILENA VERSÃO FINAL.pdf: 1584743 bytes, checksum: e7217cc7753006e33573b7f5896cabd8 (MD5) / Approved for entry into archive by Maria Lucia Martins Frederico null (mlucia@fca.unesp.br) on 2018-09-04T11:52:25Z (GMT) No. of bitstreams: 1 borguini _mg_dr_botfca.pdf: 1584743 bytes, checksum: e7217cc7753006e33573b7f5896cabd8 (MD5) / Made available in DSpace on 2018-09-04T11:52:25Z (GMT). No. of bitstreams: 1 borguini _mg_dr_botfca.pdf: 1584743 bytes, checksum: e7217cc7753006e33573b7f5896cabd8 (MD5) Previous issue date: 2018-06-29 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / O Brasil é o principal produtor mundial de maracujá, sendo a produção destinada a indústria de suco e consumo in natura. A presença de compostos bioativos nos frutos tem despertado interesse em pesquisas por apresentarem propriedades antioxidantes benéficos a saúde, tais como: fenólicos, carotenoides, vitamina C e poliaminas. O objetivo desse trabalho foi avaliar o perfil bioquímico de maracujá amarelo (Passiflora edulis Sims) sanitizado e submetido ao armazenamento. Os frutos foram adquiridos em área de produção comercial na cidade de Presidente Prudente SP. Após colhidos, foram selecionados, higienizados, e submetidos aos tratamentos de sanitização, através da imersão em água da rede de abastecimento público; água clorada; ácido peracético (Tsunami) e água ozonizada e, posteriormente, levados para câmara fria sob temperatura de 10 ±1 °C e 90 ± 2 % UR para armazenamento. As avaliações foram realizadas após a colheita e aos 7, 14, 21 e 28 dias de armazenamento em câmara fria e a cada 3 dias armazenadas em ambiente (14+3, 21+3, 28+3) simulando as condições de comercialização. As análises realizadas foram: perda de massa, pH, sólidos solúveis, acidez total titulável, compostos fenólicos (fenóis e flavonoides), vitamina C, carotenoides, ácido ascórbico e dehidroascórbico, poliaminas e atividade antioxidante pelos métodos FRAP e DPPH. O delineamento experimental foi em parcela subdividida com 4 tratamentos, 9 dias de avaliação e 4 repetições ,sendo a parcela o sanitizante e a sub parcela os dias avaliados. Houve uma tendência de aumento nos compostos bioativos quando utilizada água ozonizada, seguida do tratamento com ácido peracético, água clorada e agua de abastecimento público. Conclui-se que os sanitizantes influenciaram nos teores de compostos bioativos ao longo do tempo de armazenamento refrigerado e simulação de comercialização. Para que haja uma sanitização mais eficaz e obtenção de frutos com maiores teores de compostos bioativos, recomenda-se o uso do tratamento com água ozonizada e que sejam consumidos até os 21 dias de armazenamento. / Brazil is the world's leading producer of passion fruit, with production destined for the juice and consumer industry in natura. The presence of bioactive compounds in the fruits has aroused interest in research because they have antioxidant properties beneficial to health, such as: phenolics, carotenoids, vitamin C and polyamines. The objective of this study was to evaluate the biochemical profile of yellow passion fruit (Passiflora Edulis Sims) sanitized and submitted to storage. The fruits were purchased in commercial production area in the city of Presidente Prudente SP. After being harvested, they were selected, sanitized, and submitted to sanitization treatments, by immersing them in water from the public supply network; chlorinated water; (Tsunami) and ozonated water and then taken to a cold room at a temperature of 10 ± 1 ° C and 90 ± 2% RH for storage. The evaluations were performed after harvest and at 7, 14, 21 and 28 days of storage in a cold room and every 3 days stored in the environment (14+3, 21+3, 28+3) simulating the conditions of commercialization. The analyzes were: loss of mass, pH, soluble solids, titratable total acidity, phenolic compounds (phenols and flavonoids), vitamin C, carotenoids, ascorbic and dehydroascorbic acid, polyamines and antioxidant activity by FRAP and DPPH methods. The experimental design was subdivided into 4 treatments, 9 days of evaluation and 4 replicates, with the plot being the sanitizing agent and the subplotting the evaluated days. There was a tendency for bioactive compounds to increase when ozonated water was used, followed by treatment with peracetic acid, chlorinated water and public water supply. It was concluded that the sanitizers influenced the contents of bioactive compounds during the time of refrigerated storage and simulation of commercialization. In order to achieve a more efficient sanitization and fruiting with higher contents of bioactive compounds, it is recommended to use ozonated water treatment and consumed up to 21 days of storage.

Introduction: Hypoxia is found in solid cancerous tumours. The presence of hypoxia within tumours inhibits anti-cancer treatment strategies such as chemotherapy from being completely effective and it is suspected that multiple mechanisms contribute to the resistance. Methods: In this project a systems biology approach was applied to determine how the toxicity of doxorubicin is affected by hypoxia at the metabolome level. A multitude of analytical techniques were applied to analyse the intracellular metabolism of a monolayer of cancer cells (MDA-MB-231). Metabolic profiling was used to determine metabolite markers related to hypoxia-induced chemoresistance. For this gas chromatography mass spectrometry (GC-MS) and ultra high performance liquid chromatography mass spectrometry (UHPLC-MS) were used. Furthermore, network-based correlation analysis was developed as a novel tool to bridge the gap between metabolomics dataset and systems biology modelling. This methodology was applied to elucidate novel metabolic pathways as potential therapeutic targets to overcome hypoxia-induced chemoresistance. This algorithm determines significant correlation differences between different physiological states, and through applying graph-theory on large genome scale models; it is possible to construct a metabolic network of the pathways connecting the pair-wise correlation. Finally, imaging mass spectrometry using time-of-flight secondary ion mass spectrometry (ToF-SIMS) was developed as a tool for in situ metabolite analysis to investigate the metabolic response to chemotherapy in multi-tumour spheroids (MTSs). Results: Metabolic fingerprinting analysis characterised a snapshot of cells exposed to various environmental perturbations. Metabolite markers associated with hypoxia-induced chemoresistance were related to metabolic pathways including gluconeogenesis, DNA synthesis and fatty acid synthesis. Furthermore, network-based correlation analysis revealed specific metabolites in the fatty acid synthesis pathways were contributing to drug resistance, which included malonyl-CoA, 3-oxoeicosanoyl-CoA, stearoyl-CoA and octadecanoic acid. To facilitate the detection of metabolites in ToF SIMS datasets, a series of metabolites standard spectra were acquired. Hypoxic metabolite markers detected in ToF-SIMS data of cell lysates included glycine, lactic acid and succinic acid, which were also shown to be metabolite markers in GC-MS metabolic data. Furthermore, MTS sections were imaged using ToF-SIMS to profile the chemical response to chemotherapy treatment within the oxygen gradient. Loadings from image PCA were explored to determine the metabolic response in the highly oxygenated outer region and hypoxic inner region of the MTS. Conclusion: A multitude of analytical techniques were able to contribute to elucidating the metabolic mechanisms associated with hypoxia-induced chemoresistance. Metabolic profiling combined with a systems biology approach was further able to identify potential underlying metabolic regulation of resistance. Finally ToF-SIMS was developed as a tool for metabolite analysis in complex biological systems in situ.

Study of possibilities of thin layers depth profiling by combined use of SIMS and ToF-LEIS methods.

This study examines how queerness can be dislocated in play and the portrayal of digital entities in the computer game The Sims 4. More specifically, in what way its virtually simulated anthropocentric orientations become disoriented through alien deviation. The study aims to identify connections between the game’s transhuman hegemony, alien lives, and queer experiences. Through queer phenomenology, along with performativity theory, the study concludes that aliens become queer objects in the game world by failing to live up to human ideals, which can serve as a symbolic reference to deviations from dominant orientations, norms, and hegemonies in real life.

Thesis (M.Com. (Taxation))--University of the Witwatersrand, Faculty of Commerce, Law and Management, School of Accountancy, 2014. / Cannot copy abstract

Ion implantation and the subsequent redistribution of manganese atoms in Czochralski Silicon (Cz-Si) and Floating Zone Silicon (Fz-Si) due to thermal annealing between 300 C and 1000 C is studied using Secondary Ion Mass Spectroscopy. The samples ion implanted at 340 C showed multiple peak formation above 900 C. This was not observed for the samples ion implanted at room temperature. Cz-Si and Fz-Si showed similar redistribution profiles.

Over the last decade, the interstitial alloying of niobium has proven to be essential for enabling superconducting radiofrequency (SRF) cavities to operate more efficiently at high accelerating gradients. The discovery of "nitrogen doping" was the first readily accessible avenue of interstitial alloying in which researchers saw an increase in cavity performance. However, the serendipitous nature of the discovery led to additional research to fundamentally understand the physics behind the increase in cavity performance. This knowledge gap is bridged by materials characterization. Secondary ion mass spectrometry (SIMS) is a characterization technique which has become a staple of SRF cavity characterization that details elemental concentration profiles as a function of depth into the niobium surface with submicron resolution. SIMS has been widely used by the semiconductor industry for decades but has found less application in other fields due to the difficulty to produce reproducible data for polycrystalline materials. Much effort has been given to reduce the uncertainty of SIMS results to as low as 1% - 2% for single crystals. However, less attention has been given to polycrystalline materials with uncertainty values reported between 40% - 50% The sources of uncertainty were found to be deterministic in nature and therefore could be mitigated to produce reliable results. This dissertation documents the efforts to reduce SIMS method uncertainty which has been further used to solve mysteries regarding the characterization of SRF cavities which include predictive modeling of oxygen diffusion as well as the identification of contaminants resulting from cavity furnace treatments. / Doctor of Philosophy / Particle accelerators find many uses in society in which their complexity depends on their intended purpose. These purposes vary from projecting an image as in cathode ray tube (CRT) TVs, to creating high energy x-rays for life saving cancer treatments, to researching the very fundamental principles of science and physics. The later uses particle accelerators which are very large, spanning multiple miles, and run at extremely high energies. To keep operational costs reasonable, these instruments need to run as efficiently as possible. Therefore, superconducting radiofrequency (SRF) niobium cavities are used and are responsible for propulsion of charged particles. Although, niobium SRF cavities can pass incredibly high currents with very little surface resistance, these high-end particle accelerators push the operational boundaries of efficiency. To improve the efficiency of these cavities, an optimal concentration of impurities, such as oxygen and nitrogen, are added to the niobium surface. The addition of an impurity level that is too high or too low causes the resistance to increase which translates to higher operational costs. Therefore, it is important to accurately determine the concentration of impurities within the niobium and with high depth resolution. Secondary ion mass spectrometry is a characterization method that uses a primary ion beam to impact the surface of a material to remove atoms at the very surface. The ejected atoms are then ionized into a secondary beam which can then be detected to determine the concentration and to identify the species which was removed. Historically, this instrument has yielded results with 40% - 50% uncertainty for polycrystalline metals, such as niobium, which do not sputter evenly. With SRF cavity performance depending on accurate quantitation of impurities, a more robust method is needed. Therefore, this dissertation identifies issues which cause high uncertainties for polycrystalline materials and in addition offers mitigation strategies to reduce uncertainty to below 10%. These methods were then applied to solve real problems aimed to improve the production of niobium SRF cavities.