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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

Grundämnesanalys på S:t Hans individer : Ett metodologiskt arbete med µXRF / An element analysis on the individuals of S:t Hans : a methodological study using µXRF.

Sjögren, Phillip January 2019 (has links)
The practice of using X-Ray fluorescence analysis as a method in ar-chaeological, forensic and osteological studies have resulted in a vast amount of data. It is time and cost efficient, and the method of µXRF element analysis has been of great use to archaeologists, forensic an-thropologists and osteologists to understand dietary customs, techno-logical trade patterns, understanding of diagenesis, elemental accumu-lation in bone and more. Moreover, the method has been crucial due to its non-destructive nature since bones and ancient artifacts are fragile and thus a nonde-structive method is preferable. This essay will give the reader an intro-duction to the basics of micro X-Ray fluorescence analysis and will explore the possibilities of trace elements in right (dexter) and left (sinister) thighbones (femur) on a medieval population in Visby Got-land, namely Sankt Hans. The reader will also come to know the fun-damental principles, applications, strengths and weaknesses of mi-croX-Ray fluorescence, as well as its limitations. Keywords: µXRF, non-destructive, data, method, left, right, thigh-bone, elements, analysis.
2

Mapeamento multielementar de úlceras induzidas utilizando fluorescência de raios X

Vieira, Letícia Diniz January 2018 (has links)
Orientador: Joel Mesa Hormaza / Resumo: A úlcera péptica é provocada pelo desequilíbrio entre fatores lesivos e protetores das mucosas gástrica e duodenal, em consequência a fatores endógenos ou exógenos aos tecidos. Para seu tratamento, algumas plantas são popularmente empregadas e demonstram eficácia semelhante ou superior aos fármacos geralmente utilizados, ocasionando menores efeitos adversos. Apesar de várias pesquisas na área, a compreensão do mecanismo gastroprotetor dos compostos fitoterápicos ainda não é completa. Assim, com o objetivo de contribuir para a compreensão da ação farmacológica dos extratos de três plantas medicinais (Alchornea glandulosa, Davilla elliptica e Davilla nitida), foi realizada uma análise da distribuição elementar dos constituintes das amostras de mucosas gástricas de ratos tratados com os extratos vegetais e que tiveram úlceras gástricas induzidas por álcool ou por droga anti-inflamatória não-esteroidal (DAINE). O experimento foi realizado no Laboratório Nacional de Luz Síncrotron (LNLS) e permitiu a análise dos elementos Cl, Ca, Mn, Fe, Cu e Zn que contem relação com a formação ou neutralização das úlceras pépticas. De acordo com os mapas da distribuição dos elementos, foi possível detectar alta concentração de Fe, Cu e Zn no interior da lesão das amostras de úlcera induzida por DAINE, e de Cu, Zn e Cl no interior da lesão das amostras induzidas por álcool. Nas amostras de úlcera induzida por DAINE e tratadas com Alchornea glandulosa, as concentrações de Ca, Cu e Fe aumentaram. N... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The peptic ulcer is caused by the imbalance between harmful and protective factors of the gastric and duodenal mucosa, as a consequence of factors endogenous or exogenous to the tissues. For its treatment, some plants are popularly employed and demonstrate efficacy akin or superior to the drugs normally used, leading to less adverse effects. Although much research has been conducted in the field, the understanding of the gastroprotective mechanism of phytotherapic compounds is still not complete. Therefore, aiming to advance the understanding of the pharmacological action of the extracts of three medicinal plants (Alchornea glandulosa, Davilla elliptica e Davilla nitida), we conducted an analysis of the elemental distribution of constituents within samples of gastric mucosa from rats treated with phytoterapic extracts and affected with peptic ulcers induced by alcohol or nonsteroidal anti-inflammatory drugs (NSAIDs). The experiment was performed at the Brazilian Synchrotron Light Laboratory (LNLS) and allowed for the analysis of the elements Cl, Ca, Mn, Fe, Cu and Zn that are connected to peptic ulcers development or inhibition. According to the elemental distribution maps, it was possible to detect high concentrations of Fe, Cu and Zn inside the lesion from the NSAID-induced ulcer samples, and of Cu, Zn and Cl inside the lesion from the alcohol-induced ulcer samples. In NSAID-induced ulcer samples treated with Alchornea glandulosa, Ca, Cu and Fe concentrations were augmented... (Complete abstract click electronic access below) / Doutor
3

Micropaleontological (Foraminifera, Testate Amoeba) and µXRF Analysis of the Upper Cretaceous (Turonian) Notom Delta, Ferron Sandstone Member, Mancos Shale Formation, Central Utah, USA

Turkistani, Majed January 2020 (has links)
In this thesis, the results of microfossil, biofacies, and geochemical analyses (µXRF) of the Upper Cretaceous (Turonian) Ferron – Notom delta, Utah, USA are reported and discussed. The Notom delta is the oldest of three clastic deltas in the Ferron Sandstone Member, Mancos Shale Formation. Foraminifera and testate amoebae were recovered from ninety-eight mudstone samples among five well-exposed outcrops (Caineville North, Steamboat, Blue Hills, Neilson Wash, and Coalmine Wash). Detailed observations showed foraminifera, and testate amoebae tests have undergone post-burial compression (flattening), dissolution, and transport/reworking; therefore, identification of these assemblages to their species level is difficult. The micropaleontological analysis of the Ferron-Notom delta consists of three studies. Morphogroup analysis was applied on foraminifera and testate amoebae, where a relationship between the test morphology and habitat was established. Morphogroup analysis resulted in four main morphogroups and eleven morphotypes and were assigned to life mode, environment, and feeding strategies. Three foraminifera morphogroups and one testate amoebae morphogroup were established indicate a range of environments, from shallow shelf to shallow shelf to lagoon/estuary environments. Biofacies analysis using the morphotypes was applied on three outcrops (Caineville North, Steamboat, and Blue Hills). We use the morphotypes to define the four main biofacies using cluster analysis, and biodiversity indices. Four biofacies showed marine and fluvial (freshwater) influences. Salinity and OM indices were derived from the relationship of foraminifera morphotypes (BiS, TrS, TS) and testate amoebae morphotypes (Ta-F, Ta-D, Ta-S) that follows lithofacies trends. Because of the under-representation of calcareous foraminifera (due to taphonomic and/or diagenetic factors), the biodiversity indices are treated herein as relative measures. Despite this taphonomic bias, the agglutinated foraminifera and testate amoebae morphogroups show trends with salinity both among the outcrops and stratigraphically within the outcrops. The Blue Hills outcrop represents the most landward and lowest salinity environment (tidally-influenced backwater), Steamboat is more coast proximal with a higher salinity of the delta front and fluvial estuarine environments, and the Caineville North outcrop represents the most coast proximal (fluvial/estuarine to deltaic/prodeltaic) with salinities ranging from low to medium. It appears that the landward transport and coastward of tests was a significant source of taphonomic bias. Nonetheless, the assemblages provide useful depositional information that correlates with previously documented lithofacies data. A salinity index based on a ratio of trochospiral taxa versus testate amoebae was found to provide a useful measure of coastal proximity that matches lithofacies trends. The µXRF analysis was conducted on twenty-nine mudstone samples from the Caineville North outcrop to examine elemental proxies for paleo-salinity (Sr/Ba), organic matter (K/S), redox (V/Ni), and sediment sources (Zr/Rb, Ti/Fe, Ti/Ca). Twenty-nine surface mudstone samples collected from four lithofacies representing prodelta, delta front, fluvial valley fill and shelf environments. Fourteen elements (Ti, Fe, Ca, Sr, Ba, Ni, Rb, Zr, S, V, Cu, Mn, Si, and K) were used to calculate proxy ratios to detect variations in terrigenous sediments, carbonate production, salinity, grain size, and fluvial inputs in the Caineville North outcrop. Elemental data showed good correspondence between the elemental data and the lithofacies and microfossil indices. Sr/Ba and Ca/Fe showed relationships with carbonate content and proximity to the shoreline. The paleo-salinity proxy (Sr/Ba) did not respond to salinity, but was more responsive to lithological change of carbonate content. The microfossil salinity index seems to be a more accurate paleo-salinity indicator. The proxy for fluvial input of sediment (Zr/Rb and Ti/Fe) agree well with the lithofacies trends, and Zr/Rb and Ti/Fe showed highest values within the fluvial valley fill facies, with higher variability of Ti/Fe compared to the other lithofacies (prodelta, delta front, and shelf), corresponding to response to the proximity of the depositional sites to a fluvial sediment source. The redox proxy V/Ni matched the previously derived microfossil OM index ("bolivind-type" taxa) showing a strong relationship between eutrophication and redox trends. The study aims to establish important baseline geochemical compositions of sediment sources to establish patterns and trends with sediment succession in the deeper basin (offshore; i.e. Mancos Shale). Potentially, these nearshore to fluvial trends will provide important geochemical data to assess changes in paleoclimate, and sea-level in offshore sediment successions. / Dissertation / Doctor of Philosophy (PhD)
4

Entwicklung und Optimierung von Referenzmaterialien, Mess- und Auswertemethoden für die ortsaufgelöste Analyse von biologischen Proben

Rogoll, Anika 10 July 2023 (has links)
Die Herstellung von homogenen Referenzmaterialien ist für die ortsaufgelöste Festkörperanalytik von besonderer Bedeutung. Eine neue Methode zur Herstellung von Referenzmaterialien auf Polymerbasis unter Verwendung von Metallacetylacetonaten wurde entwickelt. Die Elemente Al, Ca, Cd, Co, Cr, Fe, La, Mg, Pb, Sr und Zn wurden im Spurenbereich eingebracht. Mit µRFA, LA-ICP-MS und LIBS konnte die homogene Elementverteilung in den auf diese Weise hergestellten Polymerschichten und deren Anwendbarkeit zur Kalibrierung von quantitativen Analysen gezeigt werden. Aufgrund der guten Stapelbarkeit der Polymerschichten, konnten diese auch für tiefenaufgelöste Messungen mittels CµRFA erfolgreich eingesetzt werden. Anhand der hergestellten Materialien wurden die Einflüsse verschiedener Messbedingungen bei LA-ICP-MS-Analysen auf das Untersuchungsergebnis evaluiert. Für die Auswertung und Visualisierung der Elementverteilungen sowie deren Kombination mit molekülspektrometrischen Daten wurden, passende Pythonskripte entwickelt.:1 Abkürzungsverzeichnis 2 Einleitung 3 Stand der Forschung 3.1 LA-ICP-MS 3.1.1 Allgemeiner Aufbau 3.1.2 Einflüsse auf das Messergebnis 3.2 Röntgenfluoreszenzanalyse 3.2.1 Allgemeines Prinzip 3.2.2 Besonderheiten der Mikro- und konfokalen Röntgenfluoreszenzanalyse 3.3 Referenzmaterialien 3.3.1 Allgemeiner Zweck 3.3.2 Kalibrierstrategien 3.3.3 Etablierte Materialien für matrixangepasste Standards 3.3.4 Referenzmaterialien auf Basis polymerer Kunststoffe 3.3.5 Zusammenfassung 4 Herstellung von Referenzmaterialien auf Basis strahlenhärtender Lacke 4.1 Hinführung zum Thema 4.2 Herstellung der Acetylacetonat-Komplexe 4.3 Einbringen der Komplexe in die Lackschichten und Bestimmung der Homogenität4.3.1 Präparation der Lackschichten 4.3.2 Probensysteme 4.3.3 Homogenitätsbestimmung 4.3.4 Analyse mit NMR 4.4 Kalibrierreihe 4.4.1 μRFA 4.4.2. LA-ICP-MS 4.4.3 Handheld LIBS 4.4.4 Tiefenprofile 4.5 Multischichtsysteme 4.5.1 Tiefenprofilmessungen gestapelter Lackschichten 4.5.2 Anwendbarkeit für die Tiefenkalibrierung 4.5.3 Temperatureinflüsse auf gestapelte Proben 4.6 Zusammenfassung 5 Einfluss verschiedener Messparameter auf das Ergebnis der LA-ICP-MS-Analysen 5.1 Hinführung zum Thema 5.2 Einfluss auf die Gesamtintensität 5.2.1 Gasflussgeschwindigkeiten 5.2.2 Beurteilung der Schussrate 5.3 Einfluss auf das Austragsverhalten 5.3.1 Skript zur Auswertung der Peakform 5.3.2 Auswertung der Peakform 5.4 Ablagerung von Material auf der Probenoberfläche 5.4.1 Analyse der geklebten Proben 5.4.2 Analyse der gestapelten Proben 5.5 Zusammenfassung 6 Etablierung einer Auswerteroutine 6.1 LA-ICP-MS-Mapping 6.1.1 Einlesen der Daten 6.1.2 Offset-Korrektur 6.1.3 Auswerten von Linienmessungen 6.1.4 Auswertung und Darstellung von Mappings 6.1.5 Clusteranalyse 6.2 Datenkombination verschiedener Analysemethoden 6.2.1 Daten der ultrahochauflösenden Molekülmassenspektrometrie 6.2.2 Probenpräparation 6.2.3 Zusammenfügen der Einzeldaten 6.3 CμRFA-Datenverarbeitung 6.3.1 Einlesen der Daten 6.3.2 Subtraktion und Addition 6.3.3 Darstellung der dreidimensionalen Elementverteilung mit MayaVi 6.3.4 Anpassung des dargestellten Volumens 6.3.5 Datenkorrektur mittels Gaußfit 6.4 Zusammenfassung 7 Zusammenfassung und Ausblick 8 Anhang 8.1 Literatur 8.2 zusätzliche Graphiken und Tabellen 8.3 Pythonskripte 8.4 Geräte und Chemikalien 8.4.1 Chemikalienliste 8.4.2 Geräte und Parameter 8.5 Publikationsliste 8.5.1 Artikel in Fachzeitschriften 8.5.2 Patenteinreichung 8.5.3 Konferenzbeiträge 8.6 Lebenslauf

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