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X-ray Fluorescence Analysis (x-ray + fluorescence_analysis)
Selected AbstractsMajor and trace element provenance signatures in stream sediments from the Kando River, San'in district, southwest JapanISLAND ARC, Issue 2 2006Edwin Ortiz Abstract Basement rocks in the catchment of the Kando River in southwest Japan can be divided into two main groups. Paleogene to Cretaceous felsic granitoids and volcanic rocks dominate in the upstream section, and more mafic, mostly Miocene volcanic and volcaniclastic rocks occur in the downstream reaches. Geochemically distinctive Mount Sambe adakitic volcanic products also crop out in the west. X-ray fluorescence analyses of major elements and 14 trace elements were made of two size fractions (<180 and 180,2000 µm) from 86 stream sediments collected within the catchment, to examine contrasts in composition between the fractions as a result of sorting and varying source lithotype. The <180 µm fractions are depleted in SiO2 and enriched in most other major and trace elements relative to the 180,2000 µm fractions. Na2O, K2O, Ba, Rb and Sr are either depleted relative to the 180,2000 µm fractions, or show little contrast in abundance. Sediments from granitoid-dominated catchments are distinguished by greater K2O, Th, Rb, Ba and Nb than those derived from the Miocene volcanic rocks. Granitoid-derived <180 µm fractions are also enriched in Zr, Ce and Y. Sediments derived from the Miocene volcanic rocks generally contain greater TiO2, Fe2O3*, Sc, V, MgO and P2O5, reflecting their more mafic source. Sediments containing Sambe volcanic rocks in their source are marked by higher Sr, CaO, Na2O and lower Y, reflecting an adakitic signature that persists into the lower main channel, where compositions become less variable as the bedload is homogenized. Normalization against source averages shows that compositions of the 180,2000 µm fractions are less fractionated from their parents than are the <180 µm fractions, which are enriched for some elements. Contrast between the size fractions is greatest for the granitoid-derived sediments. Weathering indices of the sediments are relatively low, indicating source weathering is moderate, and typical of temperate climates. Some zircon concentration has occurred in granitoid-derived <180 µm fractions relative to 180,2000 µm counterparts, but Th/Sc and Zr/Sc ratios overall closely reflect both provenance and homogenization in the lower reaches. [source] Formation of Large Clusters in the Reaction of Lanthanide Cations with HeptamolybdateEUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 13 2004Katja Burgemeister Abstract A series of new lanthanide polyoxomolybdates was synthesised by reaction of lanthanide cations with the heptamolybdate anion (Mo7O24)6,. The heteropolyanions [Ln4(MoO4)(H2O)16(Mo7O24)4]14, (Ln = LaIII, CeIII, PrIII, SmIII, GdIII) were isolated as either their ammonium or tetramethylammonium salts and characterised by X-ray structure analysis, energy dispersive X-ray fluorescence analysis, and IR and Raman spectroscopy. The central [Ln4(MoO4)(H2O)16]10+ core of the anion is coordinated by four heptamolybdate groups. Each LnIII atom in the core exhibits ninefold coordination by oxygen atoms belonging to H2O, (MoO4)2, and (Mo7O24)6, units; the central molybdenum atom is coordinated tetrahedrally by four oxygen atoms. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004) [source] Bone material quality in transiliac bone biopsies of postmenopausal osteoporotic women after 3 years of strontium ranelate treatmentJOURNAL OF BONE AND MINERAL RESEARCH, Issue 4 2010Paul Roschger Abstract Strontium ranelate (SrR) is a relatively new treatment for osteoporosis. In this study we investigated its potential impact on human bone material quality in transiliac bone biopsies from postmenopausal osteoporotic women treated 3 years with calcium and vitamin D plus either 2,g SrR per day or placebo. Bone mineralization density distribution (BMDD), strontium (Sr) concentration, collagen cross-link ratio, and indentation modulus were analyzed by quantitative backscattered electron imaging, electron-induced X-ray fluorescence analysis, synchrotron radiation induced micro X-ray fluorescence elemental mapping, Fourier transform infrared imaging, and nanoindentation, respectively. The BMDD of SrR-treated patients was shifted to higher atomic numbers (Zmean +1.5%, p,<,.05 versus placebo). We observed Sr being preferentially incorporated in bone packets formed during SrR treatment up to 6% atom fraction [Sr/(Sr,+,Ca)] depending on the SrR serum levels of the individuals (correlation r,=,0.84, p,=,.018). Collagen cross-link ratio was preserved in SR-treated bone. The indentation modulus was significantly decreased in younger versus older bone packets for both placebo- (,20.5%, p,<,.0001) and SrR-treated individuals (,24.3%, p,<,.001), whereas no differences were found between the treatment groups. In conclusion, our findings indicate that after SrR treatment, Sr is heterogeneously distributed in bone and preferentially present in bone packets formed during treatment. The effect of SrR on BMDD seems to be due mainly to the uptake of Sr and not to changes in bone calcium content. Taken together, these data provide evidence that the investigated bone quality determinants at tissue level were preserved in postmenopausal osteoporotic women after 3-year treatment with 2,g SrR per day plus calcium and vitamin D. © 2010 American Society for Bone and Mineral Research [source] Determination of intrathyroidal iodine by X-ray fluorescence analysis in 60- to 65-year olds living in an iodine-sufficient areaJOURNAL OF INTERNAL MEDICINE, Issue 1 2006M. MILAKOVIC Abstract. Objectives., X-ray fluorescence (XRF) is a non-invasive method for determining the iodine content of the thyroid gland in vivo. In spite of the obvious clinical value of such a method in situations of iodine deficiency or iodine overload, the method has not so far been widely used. The objective was to investigate the applicability of the XRF method in a larger number of subjects. Design and subjects., The study comprised 37 individuals, aged 60,65 years, who had spent their entire life with iodine supplementation through iodinated table salt. Individuals with (previous) thyroid disease were excluded. The individual thyroid function had previously been evaluated by measurements of thyroid-related hormones, thyroid volume and 131-Iodine (131I) uptake which indicated a sufficient iodine intake of the population in the area. Iodine in the right thyroid lobe in each subject was examined using XRF. Results., The mean thyroid iodine concentration was 0.4 mg mL,1, corresponding to a mean total iodine content of 5.2 mg (range 0.9,20.2). There was a pronounced difference between individuals. No correlation was found between iodine concentration and 131I uptake or thyroid volume. Neither was iodine content and 131I uptake correlated. Conclusions., In a population living under iodine-sufficient conditions, a large variation of iodine stored in the thyroid is compatible with euthyroidism. Determination of the iodine pool by XRF investigation is feasible in a clinical setting and the method offers a unique possibility to study the intrathyroidal iodine pool in subjects with thyroid disease. The low radiation dose enables the use of the method in pregnant women and also in young individuals. [source] Adhesive bonding of super-elastic titanium,nickel alloy castings with a phosphate metal conditioner and an acrylic adhesiveJOURNAL OF ORAL REHABILITATION, Issue 6 2003H. Matsumura summary, The purpose of the current study was to evaluate the bonding characteristics of super-elastic titanium,nickel (Ti,Ni) alloy castings. Disk specimens were cast from a Ti,Ni alloy (Ti-50·85Ni mol%) using an arc centrifugal casting machine. High-purity titanium and nickel specimens were also prepared as experimental references. The specimens were air-abraded with alumina, and bonded with an adhesive resin (Super-Bond C & B). A metal conditioner containing a phosphate monomer (Cesead II Opaque Primer) was also used for priming the specimens. Post-thermocycling average bond strengths (MPa) of the primed groups were 41·5 for Ti,Ni, 30·4 for Ti and 19·5 for Ni, whereas those of the unprimed groups were 21·6 for Ti, 19·3 for Ti,Ni and 9·3 for Ni. Application of the phosphate conditioner elevated the bond strengths of all alloy/metals (P < 0·05). X-ray fluorescence analysis revealed that nickel was attached to the debonded resin surface of the resin-to-nickel bonded specimen, indicating that corrosion of high-purity nickel occurred at the resin,nickel interface. Durable bonding to super-elastic Ti,Ni alloy castings can be achieved with a combination of a phosphate metal conditioner and a tri- n -butylborane-initiated adhesive resin. [source] Use of highly energetic (116,keV) synchrotron radiation for X-ray fluorescence analysis of trace rare-earth and heavy elementsJOURNAL OF SYNCHROTRON RADIATION, Issue 4 2001Izumi Nakai This study has revealed the advantages of the use of 116,keV X-rays as an excitation source of X-ray fluorescence (XRF) analyses. This technique is suitable for nondestructive multielemental analyses of heavy elements such as rare-earth elements. The lowest MDL value evaluated for the bulk analysis of a JG-1 standard reference sample (granite rock) was 0.1 p.p.m. for W for a 500,s measurement. The spectrum of standard glass samples of SRM612 demonstrated clearly resolved K -line peaks of more than 30 elements, including all the existing rare-earth elements, at 50 p.p.m. levels. The calibration curve for the determination of a rare-earth element shows a linear relation between the XRF intensity and concentrations from 10 to 0.03,ng. This powerful technique should be useful for nondestructive analyses of rare-earth and heavy elements in geological, geochemical and archaeological samples as well as industrial materials. [source] PAUL-LOUIS CYFFLÉ'S (1724,1806) TERRE DE LORRAINE: A TECHNOLOGICAL STUDYARCHAEOMETRY, Issue 5 2010M. MAGGETTI Fragments of four Terre de Lorraine biscuit figurines were subjected to porosity analysis, X-ray fluorescence analysis, X-ray diffraction analysis, backscattered-electron image analysis,coupled with energy dispersive spectrometry,and electron backscatter diffraction analysis to determine the porosity, bulk, major, minor and trace element compositions, and the composition and the proportion of their constituent phases. Cyfflé's Terre de Lorraine wares embrace two distinct types of paste, a calcareous and an aluminous,siliceous one. Both are porous (9,25% water adsorption). The former consists of a mixture of different proportions of ground quartz or calcined flint, ground Pb-bearing glass and calcium carbonate with a refractory clay. The firing temperature was between 950 and 1050°C. For the latter, Cyfflé mixed ground pure amorphous SiO2, ground quartz or calcined flint, ground porcelain, ground Na,Ca-glass and coarse-grained kaolinite with a fine-grained kaolinitic clay. The figurines were fired below 1000°C. The result was a porous, hard paste porcelain-like material. Cyfflé's recipes for both pastes can be calculated from the chemical and the modal analyses. [source] THE HISTORY OF THE LAWRENCE BERKELEY NATIONAL LABORATORY INSTRUMENTAL NEUTRON ACTIVATION ANALYSIS PROGRAMME FOR ARCHAEOLOGICAL AND GEOLOGICAL MATERIALSARCHAEOMETRY, Issue 2 2007F. ASARO The Lawrence Berkeley National Laboratory pottery provenance group developed standards and instrumental neutron activation analysis (INAA) methods that are used at many archaeometry laboratories around the world. The background and development of ,Standard Pottery' and of methods for INAA are described. Early pottery provenance studies are described, and other research programmes, involving obsidian and magmatic mixing, the origin of the stone used for the Colossi of Memnon, and the ,Plate of Brass', are mentioned. Research work by the Laboratory included the discovery of the world-wide iridium anomaly and extensive subsequent research on what has come to be known as the ,Asteroid Impact Theory'. Characteristics of the analytical programme for pottery provenance work, including overall aims, precision and accuracy, intercalibration, and irradiation and measurement protocols, are discussed. New research areas developed in the past 15 years, to broaden the usefulness of chemical compositional data for archaeological investigation, and examples of recent work, are described. This research, which makes use of high-precision X-ray fluorescence analysis in addition to INAA measurements on sample splits, includes distinguishing the products of different workshops located at the same production site, studies on the significance of the distribution of silver in archaeological pottery and the use of high-precision chemical compositional data as an aid for making chronological distinctions. [source] Wavelength-dispersive X-ray fluorescence analysis of ancient glasses,ARCHAEOMETRY, Issue 4 2002R. Falcone The application of X-ray fluorescence to the study of the composition of ancient glasses has been limited by the large amount of material required for samples. In this paper the setting of a reduced sampling XRF method for the analysis of ancient glasses is described. The method involves the preparation of glass beads by melting the sample with lithium tetraborate flux. By means of reference and synthetic samples, the method allows regression curves to be set, covering broad ranges from ppm to high concentrations. By means of a single program, up to 31 elements of interest in the study of ancient glass are analysed. The reproducibility, sensitivity and reliability of the method are discussed. The results demonstrate that 0.2 g of glass is sufficient to obtain accurate and sensitive analyses for most of the elements of interest. [source] Cloning, expression, purification and crystallization as well as X-ray fluorescence and preliminary X-ray diffraction analyses of human ADP-ribosylhydrolase 1ACTA CRYSTALLOGRAPHICA SECTION F (ELECTRONIC), Issue 5 2009Stefan Kernstock Human ADP-ribosylhydrolase 1 (hARH1, ADPRH) cleaves the glycosidic bond of ADP-ribose attached to an Arg residue of a protein. hARH1 has been cloned, expressed heterologously in Escherichia coli, purified and crystallized in complex with K+ and ADP. The orthorhombic crystals contained one monomer per asymmetric unit, exhibited a solvent content of 43% and diffracted X-rays to a resolution of 1.9,Å. A prerequisite for obtaining well diffracting crystals was the performance of X-ray fluorescence analysis on poorly diffracting apo hARH1 crystals, which revealed the presence of trace amounts of K+ in the crystal. Adding K-ADP to the crystallization cocktail then resulted in a crystal of different morphology and with dramatically improved diffraction properties. [source] The ybeY protein from Escherichia coli is a metalloproteinACTA CRYSTALLOGRAPHICA SECTION F (ELECTRONIC), Issue 11 2005Chenyang Zhan The three-dimensional crystallographic structure of the ybeY protein from Escherichia coli (SwissProt entry P77385) is reported at 2.7,Å resolution. YbeY is a hypothetical protein that belongs to the UPF0054 family. The structure reveals that the protein binds a metal ion in a tetrahedral geometry. Three coordination sites are provided by histidine residues, while the fourth might be a water molecule that is not seen in the diffraction map because of its relatively low resolution. X-ray fluorescence analysis of the purified protein suggests that the metal is a nickel ion. The structure of ybeY and its sequence similarity to a number of predicted metal-dependent hydrolases provides a functional assignment for this protein family. The figures and tables of this paper were prepared using semi-automated tools, termed the Autopublish server, developed by the New York Structural GenomiX Research Consortium, with the goal of facilitating the rapid publication of crystallographic structures that emanate from worldwide Structural Genomics efforts, including the NIH-funded Protein Structure Initiative. [source] Direct luminescence chronology of the Epipaleolithic Kebaran site of Nahal Hadera V, IsraelGEOARCHAEOLOGY: AN INTERNATIONAL JOURNAL, Issue 4 2003D.I. Godfrey-Smith We report direct luminescence ages for the culture-bearing sediments of the Kebaran site of Nahal Hadera V (NHV) in the coastal plain of Israel. Although the site contains, in addition to rich lithic deposits, plentiful mammalian bone, it has proved to be undatable using radiocarbon dating, in spite of the fact that the cultural context places the time of occupation well within the range of radiocarbon dating. In contrast, luminescence dating of the site sediments proved successful. Luminescence ages were determined using the single aliquot additive-dose (SAA) method, applied to sand-sized quartz extracts to determine past equivalent doses (De). Dose rates (R) were calculated using thick source alpha counting for the uranium (U) and thorium (Th) concentrations and x-ray fluorescence analysis for the potassium (K20) concentration. Of the five samples collected at the site, four represent cultural and subcultural deposits and the fifth represents the geological substrate for the archaeological deposit, a quartz-rich, carbonate-cemented dune sand known as aeolianite or kurkar. The luminescence age of the kurkar is 42.7 ± 6.3 ka. Human occupation of the site occurred between 21.3 ka and 14.0 ka ago, during the Last Glacial Maximum. © 2003 Wiley Periodicals, Inc. [source] | ||||||||||||||||