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Drömmar i kras : Analys av glasfragment från Birkas hamnDäcker, Bjarne January 2016 (has links)
This essay reports from a study using XRF of thirteen glass fragments found in the harbour of the Viking town of Birka some interesting observations were made. Two fragments are coloured using antimony and manganese. One fragment could have been made using wood ash glass. Two fragments contain chromium which might imply provenance from Lorraine- Alsace.
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A Multi-Proxy Approach to Identifying Marine Overwash Sedimentation and Terrestrial Flood Sedimentation in a Coastal Lake in Southeastern TexasBeaubouef, Chelsea E. 08 1900 (has links)
This research project focuses on using a multiproxy approach to discriminate between overwash and non-hurricane marsh sediments within the bed of a coastal lake. 3 marsh cores were collected in an area of McFaddin National Wildlife Refuge just south of Clam Lake that are known to contain 4 hurricane overwash deposits, Ike, Rita, Carla, and Audrey. LOI and XRF analysis were used to determine the signature of the hurricane overwash layers. 3 more cores were collected from Clam Lake where there are no visible sand layers. The elemental signature of the overwash layers found in the marsh cores was used to run a hierarchical cluster analysis on the lake cores. This was able to determine the effectiveness of XRF's ability to distinguish between hurricane overwash and marsh sediments. The combination of cluster analysis, LOI, and XRF can tentatively identify hurricane overwash deposits in a coastal lake, however, it is more successful in the marsh cores. Results in the lake cores are somewhat inconsistent and uncertain, possibly because there may have not been enough overwash deposits to identity or that the XRF analysis needs more distinct sand layers to distinguish between overwash and marsh.
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Použití přenosného XRF spektrometru pro hodnocení kvality vápencové suroviny a odhad zásob na ložisku Mořina - východ (Velká Amerika) / Application of portable XRF spectrometer for evaluation of the quality of limestone ore and estimation of reserves at the Mořina - východ (Velká Amerika) depositPechar, Tomáš January 2014 (has links)
The present thesis provides assessment potential of the Mořina - Východ deposit (Velká Amerika) as a raw material reserves for the Kozolupy - Čeřinka deposit. The reason for this work is limited lifetime of the Kozolupy - Čeřinka deposit (approx. 11-14 years) that does not allow fulfilling the requirement to ensure the production of limestone for flue gas desulphurization for ČEZ until 2035. Objective of this work is to summarize all the existing knowledge of the deposit and define the expected technological parameters of raw materials and consider the possibility of its use as a raw material for flue gas desulphurization. Special attention was paid to dolomitization of the limestone, namely to its extent and nature, because elevated Mg content lowers the quality of the limestone ore. Finally, ore reserve calculations and mining intentions are presented. On the basis of microscopic research two types of dolomite were distinguish: diagenetic and epigenetic. Diagenetic dolomite originated at shallow burial together with recrystallization of limestone slurry at temperatures up to 50 řC. Homogenization temperatures of primary fluid inclusions in epigenetic dolomite lay in the range 76-92 řC (sample A9) and 63-88 řC (sample A25).The trapping temperature of these inclusions was probably only slightly...
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Estudo e caracterização física de cerâmicas indígenas brasileiras / Study and physical characterization of native Brazilian potteryCurado, Jessica Fleury 20 April 2012 (has links)
O presente trabalho tem por objetivo caracterizar e identificar a natureza de recursos cerâmicos brasileiros utilizando métodos físicos não destrutivos. O estudo está inserido na área interdisciplinar da Arqueometria e envolve a participação de pesquisadores do Museu de Arqueologia e Etnografia da Universidade de São Paulo (MAE-USP). As amostras analisadas são de grande interesse arqueológico, pois foram coletadas em uma região do Pantanal sul-matogrossense que possui um complexo processo de ocupação envolvendo diversas tradições culturais, entre as quais a tradição Guarani e a tradição Pantanal. Os fragmentos cerâmicos foram caracterizados através das técnicas de Emissão de Raios X Induzido por Partícula (PIXE) e Fluorescência de Raios X (XRF) para a determinação da composição da matriz da pasta cerâmica e através da técnica de Radiografia Computadorizada para a investigação da estrutura interna das peças. A técnica PIXE permitiu uma caracterização dos elementos majoritários encontrados na matriz cerâmica (Z<26), usados na previsão do valor da densidade da matriz. A técnica XRF foi utilizada para determinar as concentrações elementares com destaque para os elementos minoritários (Z>26, wt%<5%) presentes na pasta cerâmica. Essas técnicas, quando associadas a métodos de análise estatísticos permitiram um melhor entendimento do conjunto de amostras. Os resultados encontrados apontam uma clara diferença na composição elementar das amostras encontradas nos diferentes sítios arqueológicos e pertencentes às diferentes tradições. Com a aplicação da técnica de Radiografia as amostras foram separadas de acordo com a presença de tempero em sua estrutura e através da análise das imagens radiográficas foi determinada a densidade dos fragmentos. Neste trabalho foi possível estabelecer uma relação entre os fragmentos cerâmicos estudados às suas tradições, assim como aos sítios arqueológicos nos quais foram coletados. / The present work aims to characterize and identify the nature of Brazilian ceramics using non-destructive physical methods. The study is inserted in the interdisciplinary area of the Archaeometry and involves the participation of researchers from the Museum of Archaeology and Ethnography of the University of São Paulo (MAE-USP). The analyzed samples are of great archaeological interest, as they have been collected in a region of Pantanal in the state of Mato Grosso do sul with a complex settlement process that involves different cultural traditions like the Guarani tradition and the tradition Pantanal. The ceramic fragments were characterized through the techniques of X-ray Emission Particle-Induced (PIXE) and X-Ray Fluorescence (XRF) to determine the composition of the matrix of the ceramic paste and using the technique of Computed Radiography for the investigation of internal structure of the sherds. PIXE technique allowed a characterization of majoritarian elements found in ceramic matrix (Z < 26) and was used in the prediction of the density of the paste. XRF technique was used to determine the elemental concentration with emphasis on the minority elements (Z> 26, wt% < 5%) presents in ceramic paste. These techniques, when associated with statistical methods of analysis allow a better understanding of the sample set. The results show a clear difference in the elemental composition of the samples found in different archaeological sites and from different cultural traditions. By applying the technique of X-ray samples were separated according to the presence of temper in its structure and through images was obtained the density of fragments. In this work it was possible to establish a link between the studied ceramic fragments to their traditions, as well as the archaeological sites in which they were collected.
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Estudo e caracterização física de cerâmicas indígenas brasileiras / Study and physical characterization of native Brazilian potteryJessica Fleury Curado 20 April 2012 (has links)
O presente trabalho tem por objetivo caracterizar e identificar a natureza de recursos cerâmicos brasileiros utilizando métodos físicos não destrutivos. O estudo está inserido na área interdisciplinar da Arqueometria e envolve a participação de pesquisadores do Museu de Arqueologia e Etnografia da Universidade de São Paulo (MAE-USP). As amostras analisadas são de grande interesse arqueológico, pois foram coletadas em uma região do Pantanal sul-matogrossense que possui um complexo processo de ocupação envolvendo diversas tradições culturais, entre as quais a tradição Guarani e a tradição Pantanal. Os fragmentos cerâmicos foram caracterizados através das técnicas de Emissão de Raios X Induzido por Partícula (PIXE) e Fluorescência de Raios X (XRF) para a determinação da composição da matriz da pasta cerâmica e através da técnica de Radiografia Computadorizada para a investigação da estrutura interna das peças. A técnica PIXE permitiu uma caracterização dos elementos majoritários encontrados na matriz cerâmica (Z<26), usados na previsão do valor da densidade da matriz. A técnica XRF foi utilizada para determinar as concentrações elementares com destaque para os elementos minoritários (Z>26, wt%<5%) presentes na pasta cerâmica. Essas técnicas, quando associadas a métodos de análise estatísticos permitiram um melhor entendimento do conjunto de amostras. Os resultados encontrados apontam uma clara diferença na composição elementar das amostras encontradas nos diferentes sítios arqueológicos e pertencentes às diferentes tradições. Com a aplicação da técnica de Radiografia as amostras foram separadas de acordo com a presença de tempero em sua estrutura e através da análise das imagens radiográficas foi determinada a densidade dos fragmentos. Neste trabalho foi possível estabelecer uma relação entre os fragmentos cerâmicos estudados às suas tradições, assim como aos sítios arqueológicos nos quais foram coletados. / The present work aims to characterize and identify the nature of Brazilian ceramics using non-destructive physical methods. The study is inserted in the interdisciplinary area of the Archaeometry and involves the participation of researchers from the Museum of Archaeology and Ethnography of the University of São Paulo (MAE-USP). The analyzed samples are of great archaeological interest, as they have been collected in a region of Pantanal in the state of Mato Grosso do sul with a complex settlement process that involves different cultural traditions like the Guarani tradition and the tradition Pantanal. The ceramic fragments were characterized through the techniques of X-ray Emission Particle-Induced (PIXE) and X-Ray Fluorescence (XRF) to determine the composition of the matrix of the ceramic paste and using the technique of Computed Radiography for the investigation of internal structure of the sherds. PIXE technique allowed a characterization of majoritarian elements found in ceramic matrix (Z < 26) and was used in the prediction of the density of the paste. XRF technique was used to determine the elemental concentration with emphasis on the minority elements (Z> 26, wt% < 5%) presents in ceramic paste. These techniques, when associated with statistical methods of analysis allow a better understanding of the sample set. The results show a clear difference in the elemental composition of the samples found in different archaeological sites and from different cultural traditions. By applying the technique of X-ray samples were separated according to the presence of temper in its structure and through images was obtained the density of fragments. In this work it was possible to establish a link between the studied ceramic fragments to their traditions, as well as the archaeological sites in which they were collected.
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Geochemická charakteristika půdního prostředí se zaměřením na kontaminaci lesních půd podél vybraných silničních komunikacíPetr, Jan January 2017 (has links)
There was investigation of elemental composition through XRF analysis. Seventeen samples were collected from around Vír and Brno dam. Samples were taken from sites with emphasis on the difference in traffic density. After analyzing the samples three of the eleven risk elements were found, including arsenic (As), lead (Pb) and zinc (Zn). Contamination level was compared with limits given by Czech Ministry of the Environment. Two samples showed increased limits in contamination, arsenic (As) and zinc (Zn). However, after statistical investigation there was not discovered a link between traffic volume and increased concentration of risk elements in the soil.
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Analysis of Inorganic Arsenic In Food Using X-Ray Fluorescence (XRF) SpectroscopyLin, Helen 28 June 2022 (has links)
Arsenic contamination in drinking water and foods is a prevalent concern across the world. Routine testing of inorganic arsenic ensures food safety but requires a cost effective, rapid high throughput, and simple detection method. The objective of this work is to develop a green method using X-Ray fluorescence spectroscopy (XRF) to analyze inorganic arsenic (iAs) in food and their interaction with emerging food contaminants: microplastics and titanium dioxide nanoparticles. XRF measures the secondary X-ray that is characteristic of each element emitted by the sample.
In a prior study, we developed an approach that combines the Gutzeit method and elemental analysis using XRF for arsenic detection in food. This approach is based on a commercial mercury bromide strip to capture arsine gas. Concerning the high toxicity of mercury bromide, we explored the feasibility of using a greener chemical, silver nitrate, to replace mercury bromide. This would benefit the safety of the operating personnel and reduce chemical hazard impact on the environment. In addition, organic acids and zinc nanoparticles were explored for iAs detection. Optimization of various reagents was done to maximize the efficacy of iAs capture and detection. The result demonstrated the greener method has a lower quantification (3.40 µg/L) compared to the original method based on mercury bromide (16.2 µg/L) due to less elemental interferences in the XRF spectrum. The standard curves of water and apple juice were compared, no significant difference was found, suggesting matrix interference is minimal. The spiked apple juice with 0 to 133 µg/L iAs had a good recovery ranging from 85-99% with an average relative standard deviation below 20%, indicating decent reproducibility.
Other than iAs detection, we also explored the XRF to study the iAs and their interaction between microplastics and titanium dioxide nanoparticles, which are considered emerging contaminants of public concerns that may serve as vectors for pollutants and potentially enhances toxicity effects. We developed a screening method to quantify the adsorption under different conditions. The result showed iAs adsorption is highly dependent of particle size and surface morphology. In conclusion, this study demonstrates the feasibility and great potential of XRF quantification of inorganic arsenic in food matrices in a cost-effective and reliable manner and the capability of rapidly quantifying the interaction with emerging contaminants such as microplastics and titanium dioxide nanoparticles.
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Metallförorenade bottensediment : En undersökning av fem sjöar påverkade av metallutvinning i Bergslagen och i Västerbottens inlandRaninen, Linn January 2017 (has links)
This study aims to assess the potential environmental risks posed by sediments in five lakes affected by present or historical metallurgy. Special attention is paid to the lakes Dammsjön and Värlingen in mid Sweden, where the sediments were contaminated after a breach in a nearby tailings dam used for storing residue from a metal processing plant. The sediments were examined for their metal content by X-ray fluorescence spectroscopy (XRF) analysis of loose powder samples. A subset of the samples from Dammsjön and Värlingen was also used for a simple pH-analysis and an experimental XRF analysis of evaporated leachate. To obtain a larger variety of samples for the XRF analysis of evaporated leachate, loose powder sediment and leachate from three additional lakes affected by extractive metallurgy, Tisken, Gruvsjön and Storjuktan, were likewise examined with XRF. The sediments from all lakes contained high levels of metals, and environmental standards for Pb (in all lakes) and Cd (in Storjuktan) were exceeded. The leachate tests showed that metals can be extracted using this method, including Cu and Ni in lake Tisken. This might indicatehigher bioavailability, but further studies are needed to confirm this interpretation. Dammsjön andVärlingen are contaminated by several metals, including Hg and As. The pH-analysis indicated that the deposited sediment is not the source of the prolonged low pH in Dammsjön, and that another source, possibly continued leaks from the tailings dam, needs to be found. The results call for close environmental monitoring, to minimise further contamination and damage to the environment.
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Distribution et mobilité de l'arsenic dans les sols : effets de cycles redox successifs / Distribution and mobility of arsenic in soils and sediments : the effects of redox cyclingParsons, Christopher 19 October 2011 (has links)
L'arsenic est un metalloïde toxique et cancérigène. Ubiquiste dans la pedosphere, il est très sensibleaux fluctuations des conditions redox du sol, ce qui influe significativement sa toxicité et mobilité. Nousétudions le cycle biogéochimique global de l'arsenic, en tenant compte de l'usage croissant des ressources, etpassons en revue l'importance respective de l’arsenic geogénique et anthropogénique dans l’environnement.La contamination à l’arsenic est souvent diffuse dans les bassins sédimentaires de l'Europe. Cependant, desconcentrations dans l'eau interstitielle du sol peuvent être élevées lors de périodes de saturation du solcausées par la monté des eaux souterraines ou les inondations, prévues d'augmenter dû aux changementsclimatiques. La spectrométrie de fluorescence X quantitative et sans standard a été utilisée pour analyserl'arsenic dans des sols relativement contaminés de la plaine alluviale de la Saône au moyen de protocoles depréparation d'échantillons conçus pour optimiser la précision d'analyse et l'exactitude in situ aux bassesconcentrations d'arsenic. L'arsenic dans ces sols est associe aux (hydr)oxydes du fer et de manganèse de lataille d'argile colloïdale. Ceux-ci subissent une dissolution réductrice par les microorganismes lors desinondations, libérant une importante concentration d'arsenic dans la phase aqueuse. Si, par la suite, l'arsenicdégagé n'est pas éliminé avec l'eau de crue évacuée, il est ré-immobilisé pendant l'oxydation du sol et lareprécipitation des oxydes métalliques. Grâce à une combinaison novatrice d'analyses chimiques par voiehumide, d’écologie microbienne, de spectroscopie ainsi que de modélisation thermodynamique et cinétique,nous démontrons que les cycles d'oxydo-réduction séquentiels entraînent une atténuation d'arsenic aqueuxdans des conditions réductrices dû à la coprécipitation croissante, et a une diminution de l'activitémicrobienne causée par l’appauvrissement en matière organique labile. Des processus d'atténuationsimilaires sont observés en l'absence d'activité microbienne pour Cr et As dans des argiles pyriteuses lorsquecelles-ci sont exposés aux oscillations redox provoquées par l'ajout de substances humiques réduites. Ainsi,nous montrons que les effets cumulatifs de cycles redox successifs sont extrêmement importants pour lamobilité de divers contaminants dans l'environnement. / Arsenic is a toxic and carcinogenic metalloid, ubiquitous in the pedosphere and highly sensitive tofluctuations in soil redox conditions which dramatically influence both its toxicity and mobility. We reviewthe global biogeochemical cycle of arsenic in light of increasing resource usage and re-evaluate theimportance of anthropogenic and geogenic arsenic inputs to the exogenic cycle. Arsenic contamination isoften diffuse in European sedimentary basins. Despite this, concentrations in soil pore-water may be highduring periods of soil saturation caused by rising groundwater or surface flooding which is predicted toincrease due to climatic change. Standardless quantitative X-ray fluorescence spectrometry is used toanalyse for arsenic in moderately contaminated soils on the alluvial plain of the Saône River with samplepreparation protocols designed to optimize analytical precision and accuracy in-situ at trace arsenicconcentrations. Arsenic in these soils is shown to be associated with colloidal and clay sized iron andmanganese (hydr)oxides which undergo microbially mediated reductive dissolution during flooding, releasingsubstantial arsenic to the aqueous phase. If released arsenic is not subsequently removed with recedingflood water it is re-immobilized during soil oxidation and re-precipitation of metal oxides. We demonstratethrough a novel combination of wet chemistry, microbial ecology, spectroscopy and thermodynamic andkinetic modelling that sequential reduction-oxidation cycles result in aqueous arsenic attenuation duringreducing conditions due to increased co-precipitation and decreases in microbial activity due to depletion oflabile organic matter. Similar attenuation processes are observed in the absence of microbial activity for Crand As in pyrite-bearing clays when subjected to redox oscillations induced by addition of reduced humicsubstances. We demonstrate that the cumulative effects of successive redox cycling are therefore of greatimportance to contaminant mobility in a variety of environments. / El arsénico es un metaloide tóxico y cancerígeno, ubicuo en la pedosfera y altamente sensible a lasfluctuaciones de las condiciones redox del suelo, las cuales controlan tanto su toxicidad como su movilidad.La presente tesis doctoral tiene como objeto de estudio el ciclo biogeoquímico global del arsénico y examinala importancia de los aportes del arsénico antropogénicos y geogénicos al ciclo exógeno tomando en cuentael uso creciente de recursos.La contaminación con arsénico es generalmente difusa en las cuencas sedimentarias europeas. No obstante,las concentraciones en las aguas intersticiales del suelo pueden ser elevadas durante los periodos desaturación causados por el aumento de aguas subterráneas o inundaciones, cuyo incremento se prevédebido a los cambios climáticos. La espectrometría de fluorescencia de Rayos-X cuantitativa y sin estándar esutilizada para analizar el arsénico en suelos relativamente contaminados en la llanura aluvial del río Saône,mediante protocolos de preparación de muestras diseñados para mejorar la precisión analítica y la exactitudin-situ a bajas concentraciones de arsénico. La presencia de arsénico en estos suelos demuestra estarasociada a los (hidr)óxidos de hierro y de manganeso de tamaño de arcilla coloidal, los cuales experimentanuna disolución reductora por acción microbiana durante las inundaciones, liberando así una importanteconcentración de arsénico en la fase acuosa. Si, posteriormente, el arsénico despedido no se elimina con elagua saliente, éste se vuelve a inmovilizar durante la oxidación del suelo y la re-precipitación de óxidosmetálicos. Gracias a una combinación innovadora de análisis químicos por vía húmeda, ecología microbiana,espectroscopia, así como modelado termodinámico y cinético, demostramos que los ciclos de oxidoreducciónsecuenciales provocan una atenuación de arsénico acuoso durante condiciones de reduccióndebido al aumento de coprecipitacion y disminución de la actividad microbiana causada por el agotamientode materia orgánica lábil. Se observan procesos de atenuación similares en caso de ausencia de actividadmicrobiana para Cr y As en arcillas piritas cuando son sometidos a oscilaciones de redox inducidas mediantela adición de sustancias húmicas reducidas. Es así como demostramos que los efectos acumulativos de ciclossucesivos de redox son muy importantes para la movilidad contaminante en una variedad de ambientes.
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X-Ray Fluorescence Measurements Of Molten Aluminum Elemental CompositionDuren, Leigh C 09 January 2008 (has links)
The aluminum industry is in need of high-speed in-situ elemental identification technology for molten metals. wTe Corporation of Bedford, MA was granted funds to research this technology for aluminum through the Advanced Technology Program (ATP) of the National Institute of Standards and Technology (NIST). As a secondary metal scrap processor, wTe Corporation is interested in increasing the value of scrap and better identification technology is one way of doing this. With better identification technology, foundries and smelters will be more confident in the melt chemistry and more apt to use secondary aluminum which decreases the energy required for processing by approximately 85%. wTe Corporation is exploring two avenues for in-situ molten metal identification: Laser Induced Breakdown Spectroscopy (LIBS) and X-Ray Fluorescence (XRF). The objectives of this work were to contribute to developing XRF technology for in-situ identification of molten metal by establishing a method of data instrumentation and analysis for XRF to determine aluminum melt composition, investigate the major alloying elements in the Al380 alloy series and determine the relationship between intensity and concentration, and to determine the effect of temperature on XRF Spectra. The XRF instrumentation development and the technical challenges associated with high temperature measurements are presented. The relationship between intensity and concentration is presented for three alloys within the 380 alloy series, and lastly it is observed that there are significant differences between liquid and solid spectra and that a calibration curve for liquid data is necessary. Several hypotheses are given as to why this difference between liquid and solid state spectra may occur.
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