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Tesi sul tema "Electron probe microanalysis EPMA"

Autore: Grafiati

Pubblicato: 19 ottobre 2024

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1

CHO, Deung-Lyong, Mi-Jung JEEN e Takenori KATO. "Validation of physical parameters in quantitative electron probe microanalysis (EPMA) Part I : mass attenuation coefficients". Dept. of Earth and Planetary Sciences, Nagoya University, 2013. http://hdl.handle.net/2237/20540.

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CHO, Deung-Lyong, Mi-Jung JEEN e Takenori KATO. "Validation of physical parameters in quantitative electron probe microanalysis (EPMA) Part II : mean ionization potential". Dept. of Earth and Planetary Sciences, Nagoya University, 2013. http://hdl.handle.net/2237/20541.

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3

Suzuki, Kazuhiro, Takenori Kato, 和博鈴木 e 丈典加藤. "CHIMEの現状と稼働状況(2009年)". 名古屋大学年代測定資料研究センター, 2010. http://hdl.handle.net/2237/14738.

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4

Schweizer, Pia. "Analyse et quantification du lithium par le développement d'un dispositif innovant de spectrométrie et microanalyse X". Electronic Thesis or Diss., Sorbonne université, 2024. https://accesdistant.sorbonne-universite.fr/login?url=https://theses-intra.sorbonne-universite.fr/2024SORUS207.pdf.

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L'analyse quantitative du lithium est aujourd'hui possible, mais repose sur l'usage de techniques destructives. Une analyse quantitative locale non-destructive est encore difficile à mettre en œuvre par les méthodes spectroscopiques classiques de laboratoire. Cette thèse vise à développer un dispositif innovant de quantification du lithium par microsonde électronique. L'implémentation d'une multicouche périodique et de fenêtres de séparation ultra fines dans un spectromètre de la microsonde de Castaing a permis la spectrométrie dans la gamme des très faibles énergies de photons X et ainsi la mesure du lithium. Malgré les difficultés qui compliquent fortement l'analyse, principalement liées aux spécificités de l'instrumentation et aux divers phénomènes physiques tels que le faible rendement de fluorescence du lithium et la forte absorption des photons caractéristiques dans l'échantillon, des premiers résultats quantitatifs ont pu être obtenus pour différents matériaux avec des fractions massiques en lithium comprises entre 4 % et 9 %. Ces résultats conduisent à des limites de détection inférieures à un pourcent. Différentes approches de quantification basées sur une mesure avec des témoins réels et sur des simulations Monte Carlo pour créer des témoins virtuels ont été mises en place. De plus, la mesure expérimentale des coefficients d'atténuation des photons dans la gamme des très faibles énergies a permis d'apporter des précisions aux bases de données existantes pour différents éléments, contribuant ainsi à l'amélioration de la précision des résultats. Malgré les défis persistants, ces travaux ouvrent la voie à de nouvelles avancées dans la quantification du lithium par microsonde électronique et constituent une première étape importante pour un futur développement de cette technique
Quantitative analysis of lithium is feasible today, but relies on the use of destructive techniques. Local non-destructive quantitative analysis remains challenging using traditional laboratory spectroscopic methods. The aim of this thesis is to develop an innovative device for lithium quantification using electron probe microanalysis. By implementing a periodic multilayer and ultra-thin separation windows into the spectrometer of a Castaing microprobe, spectroscopy in the extreme low photon energy range, including Li K measurement was possible. Despite the significant analytical challenges, mainly linked to the specificities of the instrumentation and to various physical phenomena such as low lithium fluorescence yield and strong absorption of the characteristic photons in the sample, quantitative results were obtained for different materials with lithium mass fractions ranging from 4 % to 9 % and detection limits lower than one percent. Two different quantification approaches based on measurement with real standards and Monte Carlo simulations to create virtual standards were employed. In addition, experimental measurement of photon attenuation coefficients in the ultra-soft X-ray range provided precision to existing databases for different elements, helping to improve the accuracy of results. Despite persistent challenges, this work paves the way for further advances in lithium quantification by electron probe microanalysis and represents an important first step towards future development of this technique

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5

Langlois, Jean. "The electron probe x-ray microanalysis of the adult mammalian cardiac muscle". Thesis, University of Ottawa (Canada), 1994. http://hdl.handle.net/10393/6568.

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The main objective of this project was to master the electron probe x-ray microanalysis technique to permit one to obtain physiologically meaningful quantitative elemental profiles (Na, Cl, K, P, Mg, Ca & S) for the components of a given cell. The techniques which had to be mastered were: preparation of mammalian (rat) cardiac muscle; 'rapid' cryofixation using a Reichert-Jung MM80E 'impact freezer'; cryosectioning using a Reichert-Jung FC4 cryoultramicrotome; transfer and freeze-drying; electron probe x-rays collection using the EDAX 9100 Series Energy Dispersive X-ray Analysis Systems attached to a Philips TEM 420; quantitative analysis using the Hall equation and thin membrane aminoplastic standards. Different methods of transfer and freeze-drying were compared. Method I-a. Cryotransfer to the electron microscope using a modified Philips Cryotransfer system, freeze-drying in the column of the electron microscope, x-rays collection at low temperature; Method I-b. Cryotransfer to the electron microscope using a modified Philips Cryotransfer system, freeze-drying in the column of the electron microscope, x-rays collection at ambient temperature; Method II. Cryotransfer to a vacuum chamber (Edward-Coating System E306 A) using a precooled metal carrier, freeze-drying in a vacuum chamber while warming at ambient temperature, transfer and x-rays collection at ambient temperature. (Abstract shortened by UMI.)

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6

Wroblewski, Joanna. "Studies on chondrocyte differentiation in vivo and in vitro". Stockholm : Kongl Carolinska Medico Chirurgiska Institutet, 1987. http://catalog.hathitrust.org/api/volumes/oclc/15730803.html.

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7

Suzuki, Kazuhiro, Takenori Kato, 和博鈴木 e 丈典加藤. "CHIMEの現状と稼働状況 (2011年)". 名古屋大学年代測定資料研究センター, 2012. http://hdl.handle.net/2237/18144.

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8

Suzuki, Kazuhiro, Takenori Kato, 和博鈴木 e 丈典加藤. "CHIMEの現状と稼働状況 (2010年)". 名古屋大学年代測定資料研究センター, 2011. http://hdl.handle.net/2237/16512.

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9

Pinard, Philippe T. Verfasser], Joachim [Akademischer Betreuer] [Mayer, Jochen M. [Akademischer Betreuer] Schneider e Raynald [Akademischer Betreuer] Gauvin. "Electron probe microanalysis of carbon containing steels at a high spatial resolution / Philippe T. Pinard ; Joachim Mayer, Jochen Michael Schneider, Raynald Gauvin". Aachen : Universitätsbibliothek der RWTH Aachen, 2016. http://d-nb.info/1156786452/34.

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Pinard, Philippe [Verfasser], Joachim [Akademischer Betreuer] Mayer, Jochen M. [Akademischer Betreuer] Schneider e Raynald [Akademischer Betreuer] Gauvin. "Electron probe microanalysis of carbon containing steels at a high spatial resolution / Philippe T. Pinard ; Joachim Mayer, Jochen Michael Schneider, Raynald Gauvin". Aachen : Universitätsbibliothek der RWTH Aachen, 2016. http://d-nb.info/1156786452/34.

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11

Bünger, Jonas Verfasser], Manuel [Akademischer Betreuer] Torrilhon e Joachim [Akademischer Betreuer] [Mayer. "Three-dimensional modelling of x-ray emission in electron probe microanalysis based on deterministic transport equations / Jonas Bünger ; Manuel Torrilhon, Joachim Mayer". Aachen : Universitätsbibliothek der RWTH Aachen, 2021. http://d-nb.info/1239566646/34.

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12

Kyritsis, Konstantinos. "Synthesis and characterization of high temperature cement-based hydroceramic materials". Thesis, University of Edinburgh, 2009. http://hdl.handle.net/1842/3939.

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Cement-based materials are of importance in the construction of geothermal wells and high-temperature oil and gas wells. These materials fill the annulus between the well casing and the rock forming a protective layer, known as sealant, which is used primarily to secure and support the casing inside the well. In addition it prevents entry of unwanted fluids into the well and communication between formation fluids at different levels. These cement based sealants need to perform for many years at high temperatures and in severe chemical environments; conditions which can cause the material of the well-casing to degrade resulting in reduced strength and increased permeability. The aim of this study is to develop new materials which will have the potential properties (high strength and low permeability) for use as sealants in geothermal and deep, hot oil wells. In order to do this special cement slurries, based on the CaO−Al2O3−SiO2−H2O (CASH) hydroceramic system, have been synthesised over the temperature range 200 to 350 °C (i.e. the typical working temperature of these wells). The additives used in these cement slurries are silica flour and alumina. A detailed description of a suite of novel hydroceramic compositions over the temperature range 200 to 350 °C is given. X-ray diffraction has been used to determine the mineralogical composition and Rietveld refinement to quantify the known phases present at different temperatures. In addition the chemistry of some of the major phases present has been examined using electron probe microanalysis. Scanning electron microprobe and simulation software have been employed to study the crystal shape of these major minerals. The engineering properties of the hydroceramic materials are very important. A study of the compressive strength and permeability has been carried out over a range of temperature (200 to 350 °C). In addition permeability has been calculated using simulation software and the results compared with experimental values. Hydroceramic formulations with excellent strength and permeability measurements have been found. Some of these formulations have been tested for durability under simulated well conditions. These materials have been immersed into different brines for a certain period of time at temperatures between 200 to 300 °C. Some preliminary results regarding the changes in mineralogy in these samples are presented in this thesis. These experiments have been carried out at the Synchrotron Radiation Source (SRS) using tomographic energy-dispersive diffraction imaging (TEDII).

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13

McCulla, James K. "Dating Deformation in the Palmer Zone of Transpression, Central Massachusetts: Temporal Constraints on Models for Progressive Deformation in the Middle Crust". UKnowledge, 2016. http://uknowledge.uky.edu/ees_etds/34.

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The Palmer Zone of Transpression (PZoT) in the Bronson Hill zone of central Massachusetts is an expression of late Paleozoic oblique convergence between Avalonia and Laurentia. The steeply W-dipping, N-S trending PZoT is defined by bounding high strain zones (Mt. Dumplin on west, Central Maine and Conant Brook on east) of opposing shear sense enclosing the Monson orthogneiss. Research was designed to establish the timing of deformation to test the hypothesis that strain in transpressional systems occurs contemporaneously. An understanding of the timing of deformation in this zone could elucidate the mechanisms that formed the zone and contribute to a greater overall understanding of fabric evolution in transpressional systems. U-Pb SIMS ages of zircon in deformed pegmatites in Monson orthogneiss and Paxton and Rangeley paragneisses are 369 to 364 Ma. Plutons that contain all fabrics associated with progressive transpression – lineations ranging from subhorizontal (initial) to steeply-plunging parallel to dip (final) – mark the maximum age of deformation. Ages range from 360-355 Ma in the Hardwick tonalite, Wachusett tonalite, West Warren diorite, Walker Mountain orthogneiss, and Nichewaug diorite, and indicate transpression in the PZoT initiated after ca. 355 Ma. Monazite from Rangeley paragneisses and schists selected in the context of petrofabrics and syn-deformational mineral assemblages yield U-Th-Pb EPMA chemical ages that indicate dextral transpression occurred continuously from 355 to 315 Ma. Monazite chemical ages also indicate that sinistral lateral displacement in the west-bounding Mt. Dumplin high strain zone initiated ca. 325 Ma and lasted for roughly 45 m.y., ending around 280 Ma. The data for the Central Maine zone, Conant Brook shear zone, and Greenwich syncline support the idea of contemporaneous deformation across the compartmentalized zones of a transpressive system (355-315 Ma), while the ages for the Mt. Dumplin high strain zone indicate sinistral lateral displacement overlapped dextral transpression by about 10 m.y. but generally continued later in time (325-280 Ma).

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14

Raines, Mark Douglas. "An assessment of equilibrium in the Merensky Reef : a textural, geochemical and Nd isotope study of coexisting plagioclase and orthopyroxene from Winnaarshoek in the eastern Bushveld Complex, RSA". Thesis, Rhodes University, 2014. http://hdl.handle.net/10962/d1015644.

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Evidence of mineral disequilibrium is presented for the Merensky Reef at Winnaarshoek in the eastern Bushveld Complex. Petrographic disequilibrium textures, disequilibrium in orthopyroxene, plagioclase and clinopyroxene mineral compositions as well as disequilibrium in Sm-Nd isotopic compositions of whole rock samples and coexisting plagioclase and orthopyroxene are presented. Disequilibrium textures presented include clinopyroxene exsolution lamellae in orthopyroxene; resorbed plagioclase in orthopyroxene or relict plagioclase; various inclusions such as orthopyroxene, plagioclase or clinopyroxene in larger oikocrysts of clinopyroxene or orthopyroxene; discontinuous rims of clinopyroxene surrounding orthopyroxene; resorbed orthopyroxene in clinopyroxene; and corona textures associated with olivine. These textures were used to derive a possible mineral crystallization sequence. At least two sequences of crystallization took place, both of which crystallized plagioclase first. One sequence then crystallized olivine which was then consumed to produce orthopyroxene which crystallized prior to late clinopyroxene. The other sequence indicates orthopyroxene crystallization after plagioclase crystallization, followed by crystallization of clinopyroxene. These sequences indicate at least two magmas were responsible for the genesis of the Merensky Reef and its hanging wall and footwall units. Compositionally, disequilibrium is evident in the range of compositions found in coexisting orthopyroxene, plagioclase and clinopyroxene with stratigraphic height, with particular reference to the change in mineral composition in each of the hanging wall, Reef and footwall units. Orthopyroxene compositions range in Mg numbers between 74.6 and 82.9 (77.4) in the hanging wall, 78.5 and 87.0 (avg. 81.1) in the Reef, and 77.9 and 84.1 (avg. 81.3) in the footwall. Plagioclase compositions range in An content between An64.9 and An82.3 (avg. An75.1) in the hanging wall, An56.8 to An70.8 (avg. An62.7) in the Reef, and An54.2 to An86.3 (avg. An73.2) in the footwall. In terms of Sm-Nd isotopic compositions, disequilibrium is evident between both whole rock samples and coexisting plagioclase and orthopyroxenes. Bulk rock Sm-Nd isotopic compositions show a range in ԐNd values between ԐNd (2.06 Ga) = -4.8 to -6.4 in the hangingwall, ԐNd (2.06 Ga) = -6.3 to -8.5 in the Reef, and ԐNd (2.06 Ga) = -4.5 to -6.3 in the footwall. Similar ԐNd values are present in the hanging wall and footwall units, with a clear “spike” in the Merensky Reef. ԐNd values in plagioclase are between ԐNd (2.06 Ga) = -5.8 and -7.8, while orthopyroxene isotopic Sm-Nd values are between ԐNd (2.06 Ga = -7.1 and -9.1. The mineral disequilibrium features presented within this study help elucidate the crystallization sequence of the magma as well as to constrain the contamination of the magma upon ascension and emplacement of the Merensky Reef. The results of this study favour a model where a mantle plume resulted in the ascent of a new magma which was contaminated by the assimilation of old, lower crust. Contamination took place prior to the possible lateral emplacement of the Merensky reef as a density current. 5-10% contamination of depleted mantle or a B2-“like” source by Archaean TTGs is modeled to achieve the contamination “spike” of ԐNd = -8.5 in the Merensky Reef.

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15

Leinonen, P. (Pekka). "Calcium signaling in epithelium:special focus on Hailey-Hailey and Darier diseases, neurofibromatosis 1 and transitional cell carcinoma". Doctoral thesis, University of Oulu, 2008. http://urn.fi/urn:isbn:9789514290008.

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Abstract This study utilized normal and defective epithelial cell cultures and epidermal skin samples to examine intra- and intercellular calcium signaling. The main interests of this thesis were Hailey-Hailey disease (HHD), Darier disease (DD), neurofibromatosis 1 (NF1) and transitional cell carcinoma (TCC). HHD and DD diseases are rare autosomal dominant skin disorders characterized by dissociation of epidermal keratinocytes (acantholysis) at the suprabasal layer of the epidermis. HHD and DD diseases are caused by mutations in the genes encoding the calcium pumps in the Golgi apparatus (hSPCA1) and endoplasmic reticulum (SERCA2b), respectively. Due to these mutations calcium uptake into the Golgi apparatus or ER is diminished, which is believed to cause abnormal cell junction protein processing and dissociation of keratinocytes. This study utilized electron probe microanalysis (EPMA) and demonstrated for the first time that lesional areas of HHD and DD and non-lesional areas of DD epidermis display abnormally low calcium content in the basal cell layer. Furthermore, ATP mediated calcium signaling was impaired in cultured HHD and DD keratinocytes and epidermal ATP receptor localization was disrupted. In conclusion, these results suggest that the low calcium content in the basal cell layer is the reason for suprabasal ruptures in HHD but not necessarily in DD lesions, and that abnormal ATP receptor localization contributes to the calcium signaling defects. NF1 deficient keratinocytes display abnormally low resting cytosolic calcium levels and it has been suggested that the calcium concentration in the lumen of the endoplasmic reticulum is decreased. This study demonstrated that NF1 keratinocytes rely mostly on ATP mediated calcium signaling while normal keratinocytes rely mostly on gap junctional intercellular communication (GJIC). Studies with TCC cells have demonstrated that gap junctions participate in intercellular calcium wave propagation. This thesis demonstrated that the ATP mediated pathway was also operational in calcium wave propagation in normal uroepithelial and TCC cell cultures. Furthermore, impaired calcium wave propagation in the TCC cell culture could be improved through PKC α/βI –isoenzyme inhibition with Gö6976. Gö6976 treatment increased connexin 26 clustering at plasma membrane but did not alter expression level of the protein. This thesis contains a wide repertoire of calcium detection techniques including a new cutting-edge technology for elemental calcium detection of epidermal samples. These techniques can be used for molecular specific analysis of calcium signaling in epithelial cells.

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16

Newton, Thomas Russell. "Investigation of the effect of process parameters on the formation of recast layer in wire-EDM of Inconel 718". Thesis, Atlanta, Ga. : Georgia Institute of Technology, 2008. http://hdl.handle.net/1853/22580.

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17

Thomas, Colin. "EMPA and EDXA analysis of slag from the multicomponent site of Pirque Alto, Bolivia /". 2008. http://minds.wisconsin.edu/handle/1793/37564.

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18

Píšová, Barbora. "Chemická variabilita granátů z Českého středohoří a charakterizace jejich minerálních inkluzí". Master's thesis, 2020. http://www.nusl.cz/ntk/nusl-435812.

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The samples of garnets used in this study come from clastic sediments from the drillcores Tř-1 and T-31, selected localities of the České středohoří Mountains and garnet-bearing ultramafic rocks sampled by the drillcore T-7. The contents of the major and some minor elements were determined by an electron probe microanalyzer. The garnets from the sediments were divided into 3 groups according to the contents of the end-members: 1) pyrope-, 2) almandine - pyrope- and 3) grosular - almandine-rich. Garnets from the drillcore T-7 were classified according to individual rock types in which they occurred: lherzolite, hazburgite, pyroxenite, eclogite and granulite. Chemical analyzes of garnets displayed the presence of positive correlations Cr vs. Ca vs. Ti Mn in pyrope grains. The contents of trace elements in garnets were studied by an LA-ICP-MS. After normalization to the CI-reservoir, garnets most often show lherzolite profiles of rare earth elements. Garnets of intense red and purple colors show slightly sinusoidal REE profiles. Inclusions enclosed in garnets were studied by a scanning electron microscope. If their dimensions allowed, the major and minor elements were determined by electron microanalysis for inclusions. Inclusions of amphiboles in association with spinel group minerals, carbonates and...

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19

Steinbrecher, Stefan [Verfasser]. "A unified Monte Carlo approach for quantitative standardless X-ray fluorescence and electron probe microanalysis inside the scanning electron microscope = Ein vereinheitlichter Monte-Carlo-Ansatz zur quantitativen standardfreien Röntgenfluoreszenz und Elektronenstrahlmikroanalyse im Rasterelektronenmikroskop / vorgelegt von Stefan Steinbrecher". 2004. http://d-nb.info/971858284/34.

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20

Pietersen, Kevin John. "Richards Bay zircon". Thesis, 1992. http://hdl.handle.net/10413/6044.

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Zircon from the zircon concentrate of Richards Bay Minerals was investigated with a view to understanding the morphology and provenance. The obsevations were applied to the reduction of uranium, thorium and other trace elements in the heavy mineral placer deposits. It is evident from differences in morphology, optical characteristics, cathodoluminescence, inclusion types and trace element analyses that the zircon is derived from numerous parent rocks. Rare earth element modelling reveals several possible parent rocks including rhyolites, granites, syenites, pegmatites and carbonatites. Fission track U mapping of individual zircons indicated an enrichment of U in the rims and grain terminations. The U maps were used to devise and test several methods, including abrasion and partial dissolution, to reduce the combined U and Th concentration from 450-563ppm to below 400ppm. The effect of magnetic cleaning, density separation and size classification of the zircon concentrate on the U +Th concentration was found to be negligible. Air abrasion and HF acid dissolution successfully reduced the U +Th concentrations to between 332 and 383ppm. The contribution of trace elements from inclusions, surface pit fillings and coatings, and foreign minerals within the zircon concentrate were evaluated by by scanning electron microscope identification.
Thesis (M.Sc.)-University of Natal, Durban, 1992.

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Décima, Mayco David. "Determinación experimental de secciones eficaces de producción de rayos x para las subcapas M de iridio por impacto de electrones". Bachelor's thesis, 2022. http://hdl.handle.net/11086/23793.

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Tesis (Lic. en Física)--Universidad Nacional de Córdoba, Facultad de Matemática, Astronomía, Física y Computación, 2022.
En este trabajo se determinaron secciones eficaces de producción de rayos x de la capa M de iridio, por impacto de electrones. Para ello, se bombardeó una muestra gruesa de iridio puro con un haz monoenergético de electrones a distintas energías de incidencia, entre 2 y 28 keV. La descripción de las intensidades de los rayos x primarios emitidos por una muestra extensa se realizó con la función distribución de ionizaciones. Los rayos x provenientes del iridio se detectaron utilizando un espectrómetro dispersivo en energías y los espectros obtenidos se procesaron con un robusto método de optimización de parámetros previamente desarrollado e implementado en el software POEMA. Mediante este procedimiento se obtuvieron catorce funciones analíticas que describen de manera precisa las intensidades de los espectros experimentales para rangos de energía entre 1 keV y la energía de los electrones incidentes. Como resultado del procesamiento de estos espectros, se determinaron valores para las secciones eficaces de producción de rayos x por impacto de electrones de las subcapas M2, M3, M4 y M5 entre 2 y 28 keV. Debido a la escasez de datos experimentales en la literatura, se compararon los resultados del presente trabajo con resultados obtenidos por otros autores de manera similar para elementos con un número atómico cercano.
Fil: Décima, Mayco David. Universidad Nacional de Córdoba. Facultad de Matemática, Astronomía, Física y Computación; Argentina.

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Pérez, Pablo Daniel. "Caracterización de mezclas de distintos compuestos de azufre mediante espectroscopía de emisión de rayos x /". Bachelor's thesis, 2010. http://hdl.handle.net/11086/37.

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Tesis (Lic. en Física)--Universidad Nacional de Córdoba. Facultad de Matemática, Astronomía y Física, 2010.
Se idearon métodos que permiten, mediante EPMA, diferenciar y cuantificar los compuestos presentes en una muestra (especiación). Para ello, se tomaron los espectros de rayos x emitidos por muestras preparadas con diferentes compuestos de azufre (para obtener diversos estados de oxidación). Se realizaron caracterizaciones de los espectros Kα y Kβ obtenidos y se propusieron métodos para cuantificar las muestras. Uno de ellos, consiste simplemente en seguir el desplazamiento relativo del pico Kα; otro, más elaborado, se basa en minimizar una diferencia cuadrática entre el espectro experimental y un espectro predicho; además se investigó la variación del cociente Kβ/Kα para muestras puras. La corroboración de los métodos propuestos fue positiva, demostrando que éstos pueden ser utilizados en situaciones similares a las que aquí se presentan.
Pablo Daniel Pérez.

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