Previous studies have shown an association between Pb exposure and intelligence quotient (IQ). Up until now, there is a lack of technology and methodology to assess the effects of long-term Pb exposure (such as de-myelination) in brain in-vivo. So we are developing a mouse model that will allow us to assess in vivo Pb in bone and brain structure and myelination using magnetic resonance imaging (MRI). In this project, we will discuss the feasibility of an in vivo x-ray fluorescence (XRF) system for the Pb measurement in the skeleton of whole mice. A review of literature is conducted in chapter 1. Health impacts of lead, measurement of lead, pre-existing bone Pb phantoms and mouse model selection are explained thoroughly. In chapter 2, calibration and minimum detection limits (MDLs) for the XRF measurements are documented. Calibration was performed using Plaster of Paris phantoms mimicking human bone doped with Pb concentrations ranging from 0 to 100 ppm. Detection limits for the pre-existing bone Pb phantoms were found to be 1.52 μg Pb/g plaster for 1-hour measurement. For 2 strains of Pb free mice (CD-1 and C57BL/6J), which had skull and hind facing detectors respectively, MDLs of 5.66 – 7.78 μg Pb/g and 6.69 – 8.50 μg Pb/g were determined for 3-hour measurement. This detectability of MDLs by the XRF system encourages us to proceed to measure mouse-mimicking phantoms. In order to evaluate the feasibility of a 109Cd XRF system for the Pb measurement in the skeleton of whole mice, mouse-mimicking phantoms were made and measured. The effect of variations in Pb distribution across the mouse and the applicability of the normalization in mice are discussed in chapter 3. To sum up, our system can measure Pb in whole mice in vivo at the levels of Pb in bone that are anticipated in brain de-myelination studies. Our results indicate that if multiple orientations (rotated) are measured in mice, the mean bone Pb level in whole mice will be determined accurately. / Thesis / Master of Science (MSc)

This thesis represents the first example of a pre-agricultural, pre-colonial land disturbance event in the archaeological record of North America. It demonstrates the critical importance of multivariate analysis and µ-XRF core scanning in determining precise chronologies for episodes of heightened clastic input from soil erosion, enhanced by human occupation, shellfish harvesting, and burial mound construction. / Serpent Mounds is a prehistoric (Middle Woodland Period, ca. 2000--1000 BP) burial mound complex located on the north shore of Rice Lake, in southern Ontario, Canada. The complex includes a 60m long and 10m wide sinuous earthwork ridge interpreted as a serpent effigy and eight smaller oval mound structures. Archaeological excavations determined seasonal site occupation for harvesting wild rice and shellfish and conducting mortuary rites. The timing of mound construction and site occupation is poorly constrained by limited radiocarbon dates, restricted to burials. The site is of high cultural importance as the only known effigy mound structure in Canada and is a sacred First Nations burial ground; thus all investigation must employ non-invasive techniques. High-resolution XRF Core Scanning and micropaleontologic analysis (testate amoebae) of 12 lake sediment cores was employed to investigate the timing of mound construction, and assess geochemical records of prehistoric land disturbance. Land disturbance is indicated by increased sediment flux, by rising abundance of minerogenic elements (K, Ti, Zr, Si, Fe) within a distinctive silt-rich gyttja unit. The event is also recorded in the thecamoebian assemblage, which is dominated by indicators of a eutrophic, turbid lake environment. Principal Component Analysis and Cluster Analysis of µ-XRF data identify distinctive chemofacies across several cores. AMS 14C dates for the prehistoric land disturbance episode correspond with the Point Peninsula occupation, indicating a protracted occupation period of \textasciitilde 750 years (2050 - 1300 cal BP) with two major peaks in soil erosion at 1900 and 1450 cal BP. The sedimentation rate (>1.5mm/yr) during the Middle Woodland phase of enhanced erosion was comparable to that during the 1838 CE dam construction at Hastings. The reconstructed Middle Woodland paleoshoreline and water levels indicate a shallow lake and wetland environment, with viable habitats for wild rice stands and shellfish resources. The results demonstrate that XRF Core Scanning and micropaleontological methods are important for the investigation of culturally-sensitive archaeological sites, including sacred burial grounds where conventional archaeological excavation cannot be undertaken. / Thesis / Master of Science (MSc) / Serpent Mounds is a prehistoric (Middle Woodland Period, ca. 2000 - 1000 BP) burial mound complex located in Rice Lake, Ontario. Archaeological excavation (1897 - 1970) determined the site was occupied by people of the Point Peninsula culture (ca. 2200 - 1350 BP) on a seasonal basis, for burial rites and shellfish gathering. Many questions remain with regard to the date of mounds construction, how long the site was occupied, and how occupation and construction activities impacted the local environment. The site has been designated as a National Historical Site and excavation is no longer permitted in the interest of site preservation and cultural value to First Nations. This study investigated the history of environmental changes associated with prehistoric indigenous and European land use changes using minimally-invasive methods, including sonar bathymetric mapping, XRF Core Scanning and microfossil analysis of lake sediment cores. Sonar data were employed to map the lake bottom relief (bathymetry) and to reconstruct past changes in lake levels and shoreline positions. µ-XRF methods measures changes in elemental abundance in lake core samples to identify human occupation phases and land disturbance. Microfossils (testate amoebae) track the ecosystem response to environmental changes associated with human occupation. The geochemical and microfossil data identified an interval of increased sediment delivery to Rice Lake, coinciding with the arrival of Point Peninsula peoples. The land disturbance is recognized in cores by an increase in zirconium (Zr), titanium (Ti) and other soil-derived elements. During this phase, lake levels rose gradually, wetlands expanded and wild rice was abundant resource available to indigenous peoples. Following European colonization in the 1820’s, and the construction of the Hastings Dam (1838 CE), lake levels increased rapidly by over \SI{2}{\metre}, causing a shift to a more nutrient-rich (eutrophic) lake environment and a decline in wild rice stands. Soil erosion associated with European land clearance is recorded by in a dramatic increase in the abundance of soil-derived elements.

This study reviews the theoretical and experimental aspects of the X-ray diffraction (XRD) technique and evaluates its use in identifying toxic elements or compounds in waste that has been incinerated. Many industries incinerate materials that contain large significant amounts of toxic elements, and these elements should be identified and re-moved to reduce environmental pollution. The aim of this project is to identify the elemental content of an incinerated ash sample, and to recommend a proper identification method when using XRD. Here, we test two ash samples (raw ash without any treatment and ash that has been stabilized by washing) using the software DIFFRAC.EVA that is integrated into Bruker’s diffractometer D2Phaser to match different diffraction patterns to identify the contents of the ash sample. Finally concluding the results XRF is more suitable than XRD for ash surveil-lance.

The Northern Isles are strongly influenced by changes in the North Atlantic Ocean atmosphere system and, as they project northwards from the British Isles, provide an ideal geographical opportunity to study changing climatic gradients during the last glacial/interglacial transition along with the detection of regime shifts. Three proxies, diatoms, pollen, and micro-XRF sediment chemistry, have been employed to explore the nature and timing of environmental changes within the water columns and the wider catchments of Loch of Sabiston, Orkney, and Loch of Clumlie and Loch of Grimsetter, Shetland to better understand the nature and timing of environmental change within and among the island groups. The records are constrained by radiocarbon dating, supported by tephrochronology, and the Greenland ice core chronology to enable the comparison of the records produced by this study with previous research in the North Atlantic region. The diatom and lithological results from Loch of Sabiston suggest early deglaciation at c. 23,000 cal BP followed by gradual warming (GI-1e) punctuated by the cooling events coeval with GS-1 and GI-1b. However, the pollen record reflects a lagged response in the development from colonising cold tolerant vegetation to more temperate shrub and woodland communities. The Oracadian signal is dominated by the switching on and off of the accumulation of marl which serves as a supporting indicator of warmer conditions. The Shetland landscape appears to have been deglaciated later at c. 16,400 cal BP, but also has clear representation of GI-1e and the cooling events of GI-1b and GS-1. Both the Shetland and Orkney records record the dramatic cooling of the Younger Dryas but also suggest a two stage change from colder and drier to colder and wetter conditions before the onset of the Holocene. Shetland appears to have experienced less extreme climatic changes in comparison to Orkney despite being in the same present phytogeographical region. This is likely due to the former persisting in the arctic domain and the latter being closer to the latitudinal shifts in the warmer ocean circulation of the North Atlantic during the LGIT. Comparison of the three proxies demonstrates that they may differ by several hundred years in their response to dramatic climatic changes and, therefore, highlights the strength of multi-proxy approaches to reconstructing Quaternary environments. Combining proxies such as diatom and μ-XRF scanning techniques will provide a greater understanding of the processes occurring during environmental change in this region.

<p>Many hydrocarbon reservoirs are situated in barren sequences that display poor stratigraphic control. Correlation between the wells can become extremely difficult and traditional correlation techniques can prove to be inadequate. Past studies have shown that trace and major element concentrations can be used as a correlation tool. This practice of using geochemical fingerprints to characterize between wells is called Chemostratigraphic analysis. (Pearce et al, 1999) Chemostratigraphy has been recognized as a very important correlation technique as it can be used for rocks of any age, in any geological setting as well as sequences that are traditionally defined as barren. Chemostratigraphic analyses can be used as a means of getting rid of ambiguities within data produced by traditional correlation methods such as Biostratigraphy, Lithostratigraphy and Geophysical Logging. In areas where stratigraphic data is not available it can be used to construct correlation frameworks for the sequences found in the area. The motivation behind this study is that the research is not only worthy of academic investigation, but can also provide the industry with new insights into areas that were previously misunderstood because traditional correlation methods were not adequate. The study area, the Orange basin, is located offshore South Africa and is largely underexplored. The basin, that hosts two gas field namely the Ibhubesi and the Kudu gas fields, has large potential but in the past has not been given due attention with only 34 wells being drilled in the area. The Orange basin has recently been the topic of investigation because of the belief that it may be hosts to more hydrocarbons. This study will utilise Chemostratigraphy to attempt to provide geological information on this relatively under-explored basin. The aim of this research study is to produce a chemostratigraphic framework -scheme for the Orange Basin in order to facilitate reservoir scale interwell correlation. The Objectives of this research study will be to identify chemostratigraphic units or indices, to prove the adequate use of chemostratigraphy as an independent correlation technique and to integrate the chemostratigraphy and petrophysical characteristics of the four wells to facilitate lithological identification.</p>

A better understanding of the brine-rock- supercritical CO2 interaction is needed to evaluate the risks of geologic CO2 sequestration. The geochemical effects of brine and supercritical CO2 were examined via laboratory modeling of in situ conditions on two reservoir caprocks in the Black Warrior River Basin, the Pottsville and Parkwood Formations. The clay fraction was extracted and treated at ~ 100 bar and 363 K (90 °C) over periods of up to 70 hours. Supercritical CO2 was introduced as dry ice in a pressurized vessel. Samples were observed using XRD, WD-XRF, AA, SEM, and EDS. Clay fractions contained Fe-chlorite, illite, kaolinite, and quartz. Results show the dissolution of illite, CO2-brine induced cation exchange ok K+, and the dissolution of silicate minerals. Steady-state K/Si ratios in the fluid suggest quartz re-precipitation. These interactions could adversely affect the long-term storativity of the caprock and point to a need for further study.

Hedeby Hochburg, borgen i Hedeby, har fått förhållandevis lite uppmärksamhet, jämfört med själva samhället i Hedeby. Utgrävningen från 2012 har dock väckt ett intresse, med ett antal frågor som behöver besvaras. I denna uppsats analyseras jordprover som samlats under utgrävningen, för att se om de kan visa något om den kronologiska relationen mellan borgvallen och gravarna i borgen. Tre metoder användes, FTIR (Fourier Transform Infrared Spectroscopy), röntgendiffraktion (XRD) och röntgenfluorescens (XRF). Resultaten från XRF och XRD visar på en rumslig relation mellan minst en av vallens konstruktionsfaser och nedsänkningen i ett lager innanför vallen. Relationen med gravarna är inte tydlig än, och analysen gav inga kronologiska ledtrådar. Resultatet kan användas som hypotes för vidare prövning i framti

<p>Many hydrocarbon reservoirs are situated in barren sequences that display poor stratigraphic control. Correlation between the wells can become extremely difficult and traditional correlation techniques can prove to be inadequate. Past studies have shown that trace and major element concentrations can be used as a correlation tool. This practice of using geochemical fingerprints to characterize between wells is called Chemostratigraphic analysis. (Pearce et al, 1999) Chemostratigraphy has been recognized as a very important correlation technique as it can be used for rocks of any age, in any geological setting as well as sequences that are traditionally defined as barren. Chemostratigraphic analyses can be used as a means of getting rid of ambiguities within data produced by traditional correlation methods such as Biostratigraphy, Lithostratigraphy and Geophysical Logging. In areas where stratigraphic data is not available it can be used to construct correlation frameworks for the sequences found in the area. The motivation behind this study is that the research is not only worthy of academic investigation, but can also provide the industry with new insights into areas that were previously misunderstood because traditional correlation methods were not adequate. The study area, the Orange basin, is located offshore South Africa and is largely underexplored. The basin, that hosts two gas field namely the Ibhubesi and the Kudu gas fields, has large potential but in the past has not been given due attention with only 34 wells being drilled in the area. The Orange basin has recently been the topic of investigation because of the belief that it may be hosts to more hydrocarbons. This study will utilise Chemostratigraphy to attempt to provide geological information on this relatively under-explored basin. The aim of this research study is to produce a chemostratigraphic framework -scheme for the Orange Basin in order to facilitate reservoir scale interwell correlation. The Objectives of this research study will be to identify chemostratigraphic units or indices, to prove the adequate use of chemostratigraphy as an independent correlation technique and to integrate the chemostratigraphy and petrophysical characteristics of the four wells to facilitate lithological identification.</p>

Il mio progetto di ricerca ha avuto come focus il Salento nell’età del Ferro partendo dallo studio contestuale di un sito scoperto recentemente a Vaste, nel sud della provincia di Lecce. Si tratta di un sito inedito rivelatosi particolarmente importante perché è uno dei pochi contesti ritenuti cultuali documentati nel Salento per l’età del Ferro. Si tratta di una vasta area caratterizzata dalle presenza di buche terragne i cui depositi si sono rivelati di natura rituale. È stato uno dei pochi contesti salentini che ha restituito materiale iapigio integro. La cronologia del contesto è prima metà del VII sec. a.C. L’analisi del contesto di Vaste è stata preceduta da una schedatura dei siti dell’età del Ferro editi nel Salento. L’altra parte importante del progetto è stata l’analisi chimica tramite tecnica XRF svolta presso il CEDAD su un campione di ceramica d’importazione databile tra fine VIII e VII sec. a.C. proveniente da alcuni siti salentini (Vaste, Otranto e San Vito dei Normanni) e della Basilicata (Policoro e Torre di Satriano). Il lavoro ha permesso di stabilire i luoghi di produzione delle varie classi ceramiche analizzate. / My research project will focus on the Salento region during the Iron Age; beginning with the study of a site that was recently discovered in Vaste, in the Southern province of Lecce. Little is known or has been published about the site, but as studies of the area continue it was discovered to have been one of the few sites to be officially religious in Salento during the Iron Age. Interestingly, it is a vast area characterised by the presence of ‘earth pits’, which are earthy deposits of a ritualistic nature. It is also one of the few areas in Salento where undamaged ‘Iapygian’ artefacts have been discovered. This period chronologically dates from the 7th century B.C. Further studies for this project have been done using chemical analysis (an XRF technique done in CEDAD laboratories) on pottery samples dating from the 8th to the 7th century B.C. from various sites in Salento, such as, Vaste, Otrano and San Vito dei Normanni and sites in Basilicata, such as, Policoro and Torre di Satriano.

[pt] A pesquisa em meteoritos é de extrema importância para o entendimento de certos processos astrofísicos, pois estes objetos trazem em sua estrutura informações fundamentais para a compreensão da evolução do Sistema Solar. Neste trabalho, são estudadas amostras dos meteoritos Isna, Allende e Zagami. As técnicas analíticas utilizadas foram: espectrometria de massa (252Cf-PDMS-TOF), espectroscopia vibracional (FTIR-MIR e Raman) e espectroscopias de raios X (XRF, XRD e PIXE). Além dessas análises, o meteorito Isna foi submetido a um processamento térmico com o objetivo de separar os constituintes refratários dos voláteis; as frações separadas foram analisadas por FTIR, Raman e PDMS. A composição elementar das amostras foi determinada por XRF e PIXE e comparadas. A informação dada pela técnica FTIR restringe-se praticamente à vibração da ligação Si-O. A técnica XRD fornece a composição mineralógica majoritária das fases cristalinas dos meteoritos Isna e Allende mostrando que ambos possuem olivina (forsterita - Mg2SiO4) e troilita (FeS). Os espectros Raman dos condritos carbonáceos Isna e Allende confirmam a ocorrência de olivina e revelam o grau de desordem da matéria orgânica contida em suas matrizes: o Allende tem maior grau de maturidade térmica, possivelmente por ter sido exposto a maiores temperaturas. O espectro Raman do não condrito Zagami mostra a existência de diopsídio (MgCaSi2O6). Os resultados obtidos por PDMS, para íons secundários positivos e negativos, permitem a identificação de isótopos e de estruturas silicáticas. / [en] The research on meteorites is particularly relevant for the study of several astrophysics processes since these cosmic objects carry in their structure basic information useful for the understanding of the solar system evolution. In this work, samples of the Isna, Allende e Zagami meteorites are studied. The employed analytical techniques were: mass spectrometry (252Cf-PDMS-TOF), vibrational spectroscopy (FTIR-MIR and Raman) and X-ray spectroscopies (XRF, XRD and PIXE). In another series of measurements, the Isna meteorite was thermally processed aiming to separate the material into two samples: one, having residuals with refractory minerals, and another containing the sublimated and re-condensed constituents; the two fractions were analyzed by FTIR, Raman and PDMS. The elemental compositions of the samples were determined by XRF and PIXE. FTIR results are practically limited to the Si-O link absorption. The XRD analyses of Isna and Allende meteorites inform that the majoritarian mineralogical compositions of their crystalline phases are due to olivine (forsterite - Mg2SiO4) and to troilite (FeS). The Raman spectra the carbonaceous chondrites Isna and Allende confirm the occurrence of olivine and yields the disorder degree of the organic material in their matrixes: the Allende one has a higher thermal maturity degree, suggesting that it was exposed to higher temperatures in outer space. The Raman spectrum of the achondrite Zagami sample shows the occurrence of diopside (MgCaSi2O6). The PDMS results, obtained for positive and negative secondary ions, allow the identification of isotopes and of silicate structures.