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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.
1

Chirped-Pulse Fourier Transform Microwave Spectroscopy of Fluoroiodoacetonitrile and Chloropentafluoroacetone

Kadiwar, Gautam 12 1900 (has links)
This work focuses on finding the complete iodine and nitrogen nuclear electric quadrupole coupling tensors for fluoroiodoacetonitrile using chirped-pulse Fourier transform microwave spectroscopy. Fluoroiodoacetonitrile contains two hyperfine nuclei, iodine (I=5/2) and nitrogen (I=1) and the spectra were observed with great resolution. A total of 499 transitions were observed for this molecule. The a, b and c rotational constants were obtained. A study of chloropentafluoroacetone was also done using chirped-pulse Fourier transform microwave spectroscopy. The two chlorine isotopes for this molecule, Cl-35 and Cl-37 were observed and 326 and 170 transitions were recorded, respectively.
2

Becoming Superman: Interpolating Transsexuality into the Superman Narrative

Vena, DANIEL 05 December 2013 (has links)
Reflecting the masculine ethos of the larger comic book industry, superhero comics continue to be male-dominated spaces. Within comic studies, superhero scholars problematically normalize this androcentrism by reiterating the genre’s masculinist rhetoric, repeatedly positioning superheroes as stoic figures of whiteness, nationhood, heteronormativity and able-bodied masculinity. Although some intervention has been made to challenge these interpretations, scholars fail to acknowledge how transgender and/or transsexual readers evaluate comic heroes. This thesis provides one such intervention into the field, specifically focusing on the last son of Krypton, Superman. Drawing together the work of trans, queer, feminist, psychoanalytic, and monster theorists, my research attempts to “trans” Superman; thus, (re)reading the Man of Steel in a way that distinctly reflects the experiences of those who are denied access to the figure via their/our own gender “transgressions”. By interpolating transsexuality into the Superman narrative, I rewrite the figure’s place within the genre’s cis-sexist, masculinist history and while doing so, (re)position him as a more suitable hero for the trans community. / Thesis (Master, Gender Studies) -- Queen's University, 2013-12-05 10:35:05.511
3

Association and Fragmentation Characteristics of Biomolecules and Polymers Studied by Mass Spectrometry

Rivera-Tirado, Edgardo January 2007 (has links)
No description available.
4

Determinação do perfil de compostos fenólicos na própolis vermelha de Alagoas usando técnicas de fingerprinting (impressão digital) com LC-Orbitrap-FTMS e o software MZmine. / Determination of the profile of phenolic compounds in red propolis of Alagoas using fingerprinting techniques with LC-Orbitrap-FTMS and MZmine software

Souza, Naiana Soares de 15 August 2014 (has links)
Red Propolis northeastern Brazil (Alagoas, Brazil) has been widely studied for their biological activity against parasites, microorganisms. The composition of propolis varies according to geographic region and seasonality. Currently only isoflavanas, isoflavones and some propolones / guttiferones identified in propolis in Alagoas. The aim of this study was to apply modern methods of analysis of fingerprinting and screening (Screening), using LC-Orbitrap-FTMS in combination with MZmine software for extracting data from molecular ions to carry out such studies of propolis. Four propolis samples collected in two different towns of state of Alagoas and two of Pernambuco -. Brazil in the month of June / July 2012 The 2 samples of red propolis originating Alagoas (5.0 g) were subjected to extraction with ethanol to obtain their crude extracts, the remaining sample were already sold in the form of crude extract. The extracts solubilized in ethanol, diluted to a concentration of 1mg/mL, and injected directly into the LC-Orbitrap-FTMS, MS data extracted using the software MZmine 02.10. The precise masses of the components of the extracts compared with a database of online data. The LC-FTMS analysis combined with extraction and search database online with MZmine showed the presence of over 2,000 ion in the extract but only 210 could be a probable identification. In the Histogram, analysis showed phenolic groups/chalcones acids; isoflavones/isoflavans/ pterocarpans; propolones/guttiferones/bflavonoids specific mass of bands of common substances such as propolis, present as major compounds. Samples showed differences in the chemical profile, but all showed a high frequency of propolonas, isoflavones, terpenes and guttiferones / terpenosideos. Software MZmine and techniques of LC-FTMS and are extremely applicable for the testing fingerprint and identification of new phenolic compounds, not idetificavéis by conventional techniques phytochemical present in complex matrices. / Fundação de Amparo a Pesquisa do Estado de Alagoas / A Própolis vermelha do nordeste brasileiro (Alagoas, Brasil) tem sido amplamente pesquisada por sua atividade biológica contra diversos tipos de microrganismos. A composição da própolis varia de acordo com a região geográfica e a sazonalidade. Atualmente isoflavonoides e algumas propolonas/guttiferonas foram identificados na própolis vermelha de Alagoas. O objetivo deste estudo foi aplicar métodos modernos de análise de Impressão digital e triagem (Screening), usando LC-Orbitrap-FTMS em combinação com o software MZmine para a extração de dados dos íons. Quatro amostras de própolis foram coletadas: duas na cidade Marechal Deodoro no estado de Alagoas e duas na cidade de Igarassu no estado de Pernambuco – Brasil durante o mês de Junho/Julho de 2012. As amostras de Própolis vermelha de Alagoas, cinco gramas de cada amostra, foram submetidas a extração com etanol para obtenção de seus extratos brutos, as demais foram cedidas sob a forma de extrato bruto. Os extratos foram solubilizados em etanol e diluídos para a concentração de 1mg/mL e injetados diretamente no LC-Orbitrap-FTMS. Os dados de MS foram extraídos usando o software MZmine 2.10. As Massas exatas dos componentes dos extratos foram comparadas com um banco de dados on-line. A análise de LC-FTMS combinada com extração e pesquisa em banco de dados on-line com MZmine demonstrou presença de mais de 2.000 íons no extrato, onde 210 puderam ter uma identificação provável. A análise do Histograma de frequência íons mostrou agrupamentos de ácidos fenólicos/chalconas; isoflavonoides/ isoflavanas/pterocarpanos; propolonas/guttiferonas/ biflavonoides em faixas de massas específicas como substâncias comuns a própolis vermelha e presentes como substâncias majoritárias. Apesar das amostras apresentarem diferenças no perfil químico, todas continham alta frequência dos agrupamentos vistos no histograma. O software MZmine e as técnicas de LC-FTMS são extremamente aplicavéis para identificação de novos compostos fenólicos, não idetificavéis por técnicas convencionais de fitoquímica presentes em matrizes complexas.
5

Simulating the FTICR-MS Signal of a Decaying Beryllium-7 Ion Plasma in a 2D Electrostatic PIC Code

Nakata, Michael Takeshi 15 January 2010 (has links) (PDF)
Beryllium-7 (Be-7) only decays by electron capture into lithium-7 (Li-7) with a half life of 53 days. We study the effect of ionization on this decay rate. We do so by trapping a Be-7 ion plasma in a cylindrical Malmberg-Penning trap and measuring Be-7 and Li-7 concentrations as functions of time by using Fourier transform ion cyclotron resonance mass spectrometry (FTICR-MS). We have simulated these signals in a 2-dimensional electrostatic particle-in-cell (PIC) code. The two spectrum peaks merge at high ion densities whereas at low ion densities they can be resolved. The merged peak shifts linearly according to the relative abundances of these species. We have also simulated singly-ionized beryllium-7 hydride (BeH+) and Li-7 ion plasmas at high densities. These two separate peaks shift according to their relative abundances. We describe an analytical model that explains how these peaks shift.
6

Plasmas micro-ondes d'argon à la pression atmosphérique : diagnostics et applications au nettoyage de surfaces / Atmospheric pressure argon microwave plasmas : diagnostics and applications to surface cleaning

Noel, Cédric 13 May 2009 (has links)
Les travaux présentés dans ce mémoire concernent l’étude des plasmas d’argon créés dans une cavité résonnante micro-ondes fonctionnant à la pression atmosphérique et leur application au nettoyage de surface. Tout d’abord, une étude des enjeux du nettoyage de surfaces industrielles est présentée ainsi qu’un état de l’art des solutions existantes et leurs limitations, mettant en évidence l’intérêt des plasmas comme alternative, notamment ceux fonctionnant en cavité résonnante micro-ondes à pression atmosphérique dont les particularités sont présentées. Dans le cas de l’argon, ces décharges présentent la particularité de ne pas être homogènes mais constituées de un ou plusieurs filaments de faibles diamètres, dépendant des conditions expérimentales. L’étude de la filamentation de ces décharges est l’objet du second chapitre où il a été mis en évidence les corrélations, dans le cas d’un filament unique, entre ses dimensions, sa température et la puissance dissipée et qu’il existait un seuil de puissance au-delà duquel la filamentation apparaissait. Une modélisation électromagnétique simple a été réalisée permettant de décrire l’influence des paramètres principaux de la décharge sur la filamentation. Le troisième chapitre présente les résultats de la caractérisation d’un filament d’argon par absorption laser en plasma continu et pulsé. L’effet de l’addition d’oxygène y est également présenté. Le dernier chapitre concerne l’étude de l’application des post-décharges micro-ondes à la pression atmosphérique créées dans des mélanges argon-azote et argon-oxygène au nettoyage de surface. On y étudie notamment l’interaction de ces post-décharges avec des molécules organiques modèles (acide stéarique et 1-octadécène). L’analyse de surface avec des techniques d’analyse d’extrême surface par spectrométrie de masse (ToF-SIMS et FTMS) a permis d’améliorer notre compréhension des mécanismes de nettoyage / The present work deals with the study of argon microwave plasmas generated in resonant cavity at atmospheric pressure and their application to surface cleaning. First, a study of the aim of surface cleaning of industrial surfaces is presented, followed by a state of the art of existing solutions and their limitations, showing the interest of plasmas as an alternative, especially atmospheric pressure microwave resonant cavity plasmas. In the case of argon, these plasmas have the particularity to be inhomogeneous and constituted of one or many small diameter filaments, depending on experimental conditions. The study of the filamentation of these discharges is the subject of the second chapter. In the case of one filament, correlations have been evidenced between its size, its temperature and the dissipated power. A simple electromagnetic simulation allowed us to describe the influence of the main plasmas parameters on the filamentation process. The third chapter presents results from the characterisation of a single argon filament by the mean of diode laser absorption in continuous and pulsed plasma mode. The effect of oxygen addition is also studied. The last chapter deals with the study of the use of atmospheric pressure microwave post-discharges in argon-nitrogen or argon-oxygen mixtures for surface cleaning application. We studied the interaction of such post-discharges with model organic molecules (stearic acid and 1-octadecene). Surface analyses by the mean of extreme surface analysis techniques based on mass spectrometry (ToF-SIMS and FTMS) allow us to improve our understanding of cleaning mechanisms

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