La technique ICP-AES (Inductively-Coupled Plasma Atomic Emission Spectroscopy) est fréquemment appliquée comme méthode de contrôle de la qualité dans l'industrie pharmaceutique pour vérifier le contenu en minéraux de comprimés de multivitamines. C’est une méthode très fiable et éprouvée, mais elle nécessite une longue préparation des échantillons qui réduit l'efficacité du laboratoire. Les techniques XRF (X-Ray Fluorescence) et LIBS (Laser Induced Breakdown Spectroscopy) sont des technologies étudiées afin de déterminer leur potentiel comme une approche alternative à la quantification rapide des minéraux. Leur utilisation permettrait d’économiser sur des consommables dispendieux et nocifs, d’économiser du temps de laboratoire et de quarantaines pour les produits finis. L’objectif de l’étude est de quantifier 10 minéraux dans des comprimés pharmaceutiques avec une précision qui respecte les standards de l’industrie en question. Des méthodes d’analyse appropriées à chacune des technologies évaluées sont proposées pour effectuer une quantification optimale des minéraux. Pour ce faire, une méthodologie adéquate a été développée pour la technologie LIBS permettant de tenir compte de la micro-hétérogénéité des échantillons pharmaceutiques. La méthode permet de déterminer la probabilité d’échantillonnage en fonction des tailles de particules pour chacune des espèces. Ensuite, des modèles quantitatifs multivariés et univariés ont été comparés pour chacune des technologies d’analyse. Il a été démontré que les algorithmes de régression multivariés ne sont pas significativement plus performants que les méthodes traditionnelles pour l’analyse des spectres obtenus. Par contre, en comparant les deux technologies d’analyse, XRF permet d’obtenir des erreurs de prédiction inférieures (MEP = 15 %) à LIBS (MEP = 30 %) ainsi que des courbes de calibration significativement plus linéaires. Toutefois, quoique la technologie LIBS semble obtenir des performances inférieures en général, elle promet certains avantages pour des applications futures telles que les possibilités suivantes : 1- faire du profilage en trois dimensions, 2- échantillonner de très faibles quantités et 3- n’avoir aucune préparation d’échantillon. Au final, LIBS offre davantage de forces pour des applications d’échantillons homogènes ou en profilage alors que XRF serait préférable pour les échantillons hétérogènes. Suite aux efforts de développement de modèles quantitatifs, une analyse des effets de matrice pour la technologie LIBS a permis d’évaluer l’effet de diverses propriétés des matrices en fonction de l’intensité LIBS observée. La concentration volumique élémentaire, la conductivité thermique, la masse volumique des comprimés et la proportion molaire élémentaire dans le plasma sont toutes des propriétés ayant montré des corrélations importantes (R2 ≥ 0.5) avec l’intensité LIBS. En ce qui concerne l’applicabilité au niveau industriel, les erreurs de prédiction obtenues pour les technologies XRF et LIBS ne rencontrent pas les standards pharmaceutiques faisant ainsi que l’application de ces technologies est impossible au moment actuel. Toutefois, d’autres applications simplifiées sont proposées à partir des observations effectuées lors de ces travaux de recherche.

Det är allmänt känt att stora mängder kemikalier används i textilindustrin och även om det är att föredra att återanvända och återvinna textil kommer oönskade kemikalier stanna kvar i det cirkulära kretsloppet. Vid sortering av textil behöver de varor med giftiga, miljö- och hälsofarliga ämnen sorteras bort och uteslutas ur kretsloppet. Det finns ännu ingen icke destruktiv portabel metod utvecklad för att skilja på textil med respektive utan farliga kemikalier. I det här arbetet har analysmetoderna Fourier transform infrarödspektroskopi (FTIR) och röntgenfluorescensdetektion (XRF) undersökts för möjlighet till användning i en sorteringsprocess. Testerna som utfördes var oförstörande tester, utan provberedning, på textila prover. Obehandlade samt färgade respektive fluorkarbonbelagda prover testades. I analyserna av testresultaten jämförs de behandlade proverna med de obehandlade. De testade proverna har också matchats mot två olika befintliga generella materialbibliotek, för att identifiera provets materialinnehåll. Ett materialbibliotek uppfördes med alla de textila material som testats. Mot detta bibliotek matchades ett antal använda klädesplagg med syfte att undersöka potentialen för ett textilanpassat materialbibliotek. FTIR-tester utfördes på ett stationärt instrument medan det för XRF användes ett portabelt instrument, dock finns båda teknikerna att tillgå som handhållna, portabla instrument. Testresultaten visar att XRF inte kan detektera textila fibrer men kan detektera kemikalier innehållande vissa tyngre grundämnen. Däremot gick det inte i testerna att indikera svavelinnehåll i ullproverna, vilket hade förväntats på förhand. Testerna med FTIR visade att det går att skilja på de vanligaste fibrerna inom fiberklasserna cellulosa, protein och syntet; bomull, ull och polyester. Däremot går det inte att skilja olika cellulosafibrer från varandra, vilket även inkluderar regenererade fibrer. Polyamid och polyester är mycket olika och går att skilja åt, dock är polyamid svår att skilja från silke och ull då deras kemiska struktur är mycket lika varandra. I undersökningarna gick det inte att se någon skillnad mellan de färgade proverna och deras respektive referensprov, inte heller gick det att skilja det fluorkarbonbelagda provet från ett obelagt. Matchningarna av de använda kläderna mot det textila materialbiblioteket visade goda resultat då majoriteten av plaggen matchades mot önskat material.

Obsidian source attribution has become an important tool in examining many aspects of prehistoric lifeways including exchange, identity, social and economic boundaries, and many others. This thesis provides a comprehensive look at obsidian spatial distributions in the Tucson Basin Hohokam Pre-Classic period, ca. A.D. 750-1150. By examining currently available data and providing new data from three sites in the northern Tucson Basin conclusions about trends in spatial and temporal use of obsidian are made. Obsidian procurement and spatial distribution in the Tucson Basin appears to be distinct from neighboring regions and continuity with later Classic period, ca. A.D. 1150-1450 obsidian use is likely. There appears to be a clear preference for western obsidian sources in the northern Tucson basin, while the southern basin may have a slight preference for materials to the east. The limited obsidian data for the Colonial period, ca. A.D. 750-950 suggests that its distribution was controlled by similar processes to those observed in the Sedentary period, ca. A.D. 950-1150. This research further suggests that strong avenues are open for future research.

No description available.

Climate archives are of greatest significance when it comes to paleoclimate studies, since these types of archives in a natural way have registered and preserved the conditions of the past. There are several types of climate archives, one of the most commonly used are lake sediments, because lakes can reveal different types of information, for example weathering, vegetation and precipitation. Another reason why lakes are important in climate research is because they are widely spread over the world, and therefore they can be chosen depending on where the focus of the study will be. In this study, -the Lake Kuchi in the southern part of Taiwan, situated at the boundary between the Asian Mainland and the Western Pacific, was used. What makes this densely populated region of the world particularly interesting for climate research is because it is affected not only by monsoons, but also by typhoons and earthquakes. In this paleoclimate study, a total 16 core sections from three different coring points in the Kuchi Lake were analyzed. The main goal was to clarify if the lake could be used as a reliable climate archive, and also interpret the depositional environment of the sediment layers in the cores. All core sections were described and analyzed with the ITRAX XRF-scanner, which lead to the conclusion that the cores consist of a sedimentary sequence of alternating gray clay and dark gray gyttja clay layers, capped by peat, gyttja or clayey gyttja at topmost part.  By sieving samples from all different layers, it was observed that some dark gyttja clay layers contained terrestrial organic matter, and hard, angular clay clasts that suggest intense rain falls and flash floods as transportation mechanism. The uppermost part of the cores, from 310 cm to the top layers, consist of homogenous clay and in situ organic matter which indicate calmer depositional environments compared to the alternation between dark gyttja clay and homogenous gray clay. LOI-950 data indicate that the carbonate content of the Kuchi Lake is low, since the weight loss during this temperature is insignificant compared to LOI-550, which stood for the majority of the weight loss. Thus, the sediment sequence in the Kuchi Lake consist of alternation of clays deposited in a calm and relatively deep lake, mixed with layers apparently flushed in from land, possibly due to typhoons. This alternation is capped by organic rich layers, including peat, which indicating filling up of the basin, and shallower conditions.

The purpose of this study is to identify and analyze the geochemical facies of the Hushpuckney Shale using XRF scanning data and the bioturbation indices, which will contribute to a better understanding of the biogeochemical environment prevalent during the deposition of the Hushpuckney Shale. The Hushpuckney Shale Member of the Swope Formation (Kasimovian Stage) preserved in KGS Spencer core 2 - 6, consists of a black shale submember overlain by bioturbated gray shale. Millimeter-scale core description and analysis of XRF scanning data enables identification of geochemical facies within the study core and contributes to understanding the environment of shale deposition. The XRF spectrometer produces X-ray image of the core and abundance values of selected major and trace elements, including iron (Fe), calcium (Ca), sulfur (S), molybdenum (Mo), zinc (Zn), vanadium (V), chromium (Cr), copper (Cu), nickel (Ni), titanium (Ti), zircon (Zr), potassium (K) and phosphorous (P). Canfield and Thamdrup's (2009) classification of geochemical environments is used to recognize oxic/aerobic, manganous-nitrogenous, ferruginous and sulfidic facies within the black shale submember. A modification of Droser and Bottjer's (1986) semi-quantitative field classification of bioturbation is used to identify facies variations within the gray shale submember. Abundance of apatite nodules and lamina in the black shale submember of the study core suggest that black shale sediments accumulated slowly in a sediment-starved basin. A high abundance of sulfide-scavenged elements, including Mo, Zn, V, Ni and Cr, identifies the sulfidic facies in the black shale submember, and indicates deposition in an oxygen-depleted environment with a high concentration of hydrogen sulfide. The overlying ferruginous facies has lower abundances of sulfide-scavenged elements and lacks cryptic Fe-laminations. The uppermost black shale submember facies, the manganous-nitrogenous facies, has cryptic Fe laminations and a relatively high P/Ca ratio. Abundance of cryptic iron laminations and apatite nodules and lamina indicates the syngenetic deposition of iron and phosphate due to Fe-P coupling mechanism. The gray shale submember is burrowed, indicating deposition under oxygenated conditions. Bioturbation indices reveal the variations in the intensity and nature of burrows within the gray shale, which corresponds to the changes in the depositional environment that may be related to the rise and fall of sea-level.

From excavations of burial complexes of the Early Bronze Age Cyclades (c. 3000-2200 BC) we know that obsidian was just as important and as widely consumed in burial contexts as it was in contemporaneous household contexts; Early Bronze Age Cycladic tomb assemblages are dominated by beautiful obsidian blades produced through a unique knapping technique reserved for burial contexts (Carter 2007; Dickinson 1994). The lack of sourcing studies in the area is an unfortunate pitfall in Aegean archaeology, as understanding patterns of source selection provides us with precious insight into the complex social structures and behaviors that characterized these ancient communities. The research detailed in this thesis set out to accomplish these goals for obsidian assemblages from 11 Early Cycladic cemeteries. Structurally, these assemblages are dominated by pressure-flaked blades manufactured specifically for funerary consumption, but also include a small number of blade cores and some pieces of flaking debris. Contextually, the composition of the assemblages reflects the social significance of body modification amongst these islanders, with the blades themselves likely used for depilation, scarification, and tattooing, and the cores reemployed as pestles in the grinding of pigments, as evidenced by pigment residues located on the artifacts (Carter 1998). Two additional assemblages from settlements on Crete were analyzed, one from a Late Neolithic cave site and another from a Late Minoan settlement. These assemblages served both to provide additional regional and temporal context for the Early Cycladic findings and to advance obsidian sourcing efforts in the Aegean as a whole. In order to characterize the chemical profiles of these artifacts for sourcing purposes, this study employed portable X-ray fluorescence spectrometry, a non-destructive archaeometric method which allows for the time- and cost-effective mass-sampling of objects on-site. The results display clearly that the Early Cycladic artifacts are overwhelmingly made from Melian obsidian, and approximately 88% derive from the Sta Nychia source. How far-reaching this procurement bias is throughout the Early Bronze Age Aegean is currently difficult to say, though contemporary data from previous studies, as well as the results obtained from the two Cretan assemblages in this study, seem to show a similar pattern. Future research integrating regional traditions of obsidian source selection with previously defined regional distinctions in pressure-blade technology is necessary in order to begin to map communities of practice across the broader Aegean.

Hurricanes are amongst the most devastating of the world’s natural disasters and can cause billions of dollars’ worth of damage every year. Efforts to predict where and when tropical cyclones might strike, then, could potentially save money and lives. A lack of data exists for the GA coast, and the future direction of climate change could potentially bring more hurricanes to the state. This study provides information to enhance the paleohurricane record by examining three vibracores drawn from St. Catherines Island, GA. After interpreting the environments that generated the sediment found in one of these cores and corroborating evidence from the additional cores, six potential hurricane events were discovered, five of which were likely major hurricanes, category 3 or higher. Magnitudes were determined by comparison to event six, thought to be “The Great Gale of 1804”, a major hurricane recorded by the sedimentary record of St. Catherines Island.

Roadside soils are affected by traffic. Topsoil samples were collected at 35 Moravian localities with varying traffic intensity. They were analyzed by XRF spectrometry to obtain total element composition. The evaluation of results was carried out with an emphasis on risk elements (Cr, Ni, Cu, Zn, As, Mo, Cd, Pb). Positive correlation between traffic intensity and Cu and Pb content in the soil was discovered. The evaluation of the level of contamination was carried out on the basis of the limits announced by the Czech Ministry of Environment. The whole diploma thesis is supplemented by a review in order to provide a comprehensive view on this extensive issue.

Loess from west Greenland was studied to evaluate Holocene paleoclimate in the Arctic region. Deposits of loess are formed over long time scales through deposition of fine aeolian sediment and they exist in several places in the world. The main aeolian dust source in the study area is glaciofluvial material derived from the Greenland Ice Sheet (GrIS). Studying and understanding paleoclimate can help to make better predictions about the future in this sensitive region. Apart from sea level rise, melting of the GrIS also leads to an increase of aeolian dust as it gets released from the ice, which influences atmospheric and metrological phenomenon as well as the ice sheet’s albedo. This creates negative feedback mechanisms through increasing melting rates of glaciers and warming of the Arctic. Loess samples from two sites in the Kangerlussuaq area were analyzed and the mineral composition was measured with X-Ray Florescence Spectroscopy (XRF). With the measured mineral content, weathering indices were calculated to identify rates of weathering during the Holocene. Increased weathering intensities indicate warmer and more humid climate. The deposits in Greenland are relatively thin. Radiocarbon dating of the sediment suggests that the oldest parts of the profiles are about 4000 cal. yr B.P. (calibrated years before present). Arctic loess has not been studied very extensively. Weathering indices and ratios developed for classical loess, that had not been tested on Arctic loess, was used. The results were plotted by depth and age to visually identify changes over time. By considering the geology, climate and local conditions of the study area, some weathering indices seemed to be suitable, generating matching trends between the two sites. Compared with results from previous studies, the results also seemed credible. / Löss från västra Grönland studerades för att utvärdera holocent paleoklimat i Arktis. Lössjordar bildas över långa tidsskalor genom avsättning av fint vindburet sediment och de finns på flera platser i världen. Den huvudsakliga källan till det vindburna sedimentet i studieområdet är glaciofluvialt material härstammande från Grönlandsisen (GrIS). Att studera och förstå paleoklimat kan underlätta skapandet av bättre prognoser om framtiden i denna känsliga region. Bortsett från höjning av de globala havsnivåerna leder smältningen av GrIS också till en ökning av vindburet sediment då det frigörs från isen, vilket påverkar atmosfäriska och metrologiska fenomen samt isens albedo. Detta skapar negativa återkopplingsmekanismer genom ökande smälthastighet av glaciärer och uppvärmning av Arktis. Lössprover från två ställen i Kangerlussuaq-området analyserades och mineralsammansättningen mättes med röntgenstrålningsspektroskopi (XRF). Med det uppmätta mineralinnehållet beräknades vittringssindex för att identifiera vittringshastigheter under Holocen. Ökad vittringsintesitet indikerar varmare och fuktigare klimat. Avlagringarna på Grönland är relativt tunna. Kol-14-datering av sedimentet antyder att de äldsta delarna är cirka 4000 cal. yr B.P. (kalibrerade år före nutid). Arktisk löss är relativt ostuderad. Vittringsindex som har utvecklats för klassisk löss i tempererade regioner, och tidigare inte testats på arktisk löss, användes. Resultaten ritades i grafer efter djup och ålder för att visuellt identifiera förändringar över tid. Genom att ta hänsyn till geologin, klimatet och lokala förhållanden i studieområdet, verkade några av vittringsindexen ge trovärdiga resultat då matchande trender mellan bägge profiler kunde utläsas. I jämförelse med resultat från tidigare studier verkade resultaten också trovärdiga.