A5101978508- X-ray Spectroscopy and Fluorescence Analysis
- Astro and Planetary Science
- Planetary Science and Exploration
- Cultural Heritage Materials Analysis
- Advanced X-ray and CT Imaging
- Nuclear Physics and Applications
- Astrophysics and Star Formation Studies
- Advanced X-ray Imaging Techniques
- High-pressure geophysics and materials
- Photosynthetic Processes and Mechanisms
- Metal-Catalyzed Oxygenation Mechanisms
- Spectroscopy and Quantum Chemical Studies
- Electron and X-Ray Spectroscopy Techniques
- Conservation Techniques and Studies
- Stellar, planetary, and galactic studies
- Laser-induced spectroscopy and plasma
- Space Exploration and Technology
- Building materials and conservation
- Medical Imaging Techniques and Applications
- Diamond and Carbon-based Materials Research
- X-ray Diffraction in Crystallography
- Radioactive element chemistry and processing
- Enzyme Structure and Function
- Heavy metals in environment
- Metal complexes synthesis and properties
European Synchrotron Radiation Facility
2011-2024
European Science Foundation
2002-2019
Centre de recherche et de restauration des musées de France
2007
Louvre
2007
Centre National de la Recherche Scientifique
2007
Institute of Mineralogy
2002
Universidad de Sevilla
2001
Philipps University of Marburg
1998-2000
Elkhorn Slough Foundation
2000
European Molecular Biology Laboratory
1997-1999
ABSTRACT The dissimilatory Fe(III)-reducing bacterium Geobacter sulfurreducens reduced and precipitated Tc(VII) by two mechanisms. Washed cell suspensions coupled the oxidation of hydrogen to enzymatic reduction Tc(IV), leading precipitation TcO 2 at periphery cell. An indirect, Fe(II)-mediated mechanism was also identified. Acetate, although not utilized efficiently as an electron donor for direct cell-mediated technetium, supported Fe(III), Fe(II) formed able transfer electrons abiotically...
Seven particles captured by the Stardust Interstellar Dust Collector and returned to Earth for laboratory analysis have features consistent with an origin in contemporary interstellar dust stream. More than 50 spacecraft debris were also identified. The candidates are readily distinguished from impacts on basis of elemental composition and/or impact trajectory. seven candidate diverse composition, crystal structure, size. presence crystalline grains multiple iron-bearing phases, including...
ID21 beamline (ESRF) offers combination of μXRF, μXANES (2.0–9.1 keV), μXRD and μFTIR, increasingly used to analyse artistic ancient materials.
Ancient paintings are complex materials in terms of chemical analysis because they usually made organic/mineral, amorphous/crystallized, major/minor mixtures, evolving with time, and organized micrometric multi-layered arrangements. In this context, synchrotron micro-imaging techniques offer a powerful analytical platform to reveal the two dimensional atomic, molecular structural compositions such systems, at micrometre resolution. The selected examples illustrate main concerns restorers...
The ESRF beamline ID26 is dedicated to X-ray absorption spectroscopy on Ultra dilute samples.Technical characteristics are briefly described : optics, monochromator, detectors
Resting cells of the sulfate‐reducing bacterium Desulfovibrio desulfuricans ATCC 29577 were able to precipitate radionuclide technetium, supplied as pertechnetate anion (TcO4 ‐), under anaerobic conditions by two discrete mechanisms. Sulfidogenic cultures, with sulfate and lactate an electron acceptor donor, respectively, precipitated insoluble sulfhide. Using microscopy in combination energy‐dispersive x‐ray analysis (EDAX), was shown be extracellular, contained S major element at a...
Fe K-edge XANES spectra have been measured in more than 35 Fe(II) and Fe(III)-bearing minerals. The separation between the average pre-edge centroid positions for Fe(III) is 1.4 +/- 0.1 eV. Examination of calculated features mechanical mixtures phases containing different proportions reveals that trends position vs. intensity can be observed, depending on coordination environment. Both parameters used to estimate ferric/ferrous ratio 12 natural
A versatile instrument for the in situ study of catalyst surfaces by surface x-ray diffraction and grazing incidence small angle scattering a 13 ml flow reactor combined with reaction product analysis mass spectrometry has been developed. The bridges so-called "pressure gap" "materials at same time, within one experimental setup. It allows preparation catalytically active single crystal is also equipped an evaporator deposition thin, pure metal films, necessary formation particles on oxide...
The ID21 Scanning X-ray Microscope (SXM) is optimized for micro-spectroscopy with submicron resolution in the 2 to 9.5 keV energy range. After a brief description of microscope setup, we present here recent developments, particular, latest version compact Wavelength Dispersive Spectrometer and refurbished cryo-stage.
Not just a pretty face: Non-invasive X-ray fluorescence spectroscopy was used to reveal the sfumato paint layer stacking method that by Leonardo da Vinci faces in seven of his paintings. A strong diversity technique could clearly be seen with this method.
The geometrical structure of the tetraaquo and tetrachloro Pt(II) complexes in aqueous solutions has been studied by means X-ray absorption spectroscopies (EXAFS XANES), combined with quantum-mechanical computations. latter were carried out to supply independent information about arrangement water molecules around complexes. To this aim [PtCl4]2-•(H2O)2 [Pt(H2O)4]2+•(H2O)8 structures optimized XANES spectra computed using theoretical structural compared experimental spectra. From comparison...
Grünewald is a famous German painter of the 16th century, whose celebrity associated with his unique skill in handling colors. This article presents analysis materials used to render metallic aspect Isenhein Altarpiece and Basel's Crucifixion. Such samples are challenging objects for microanalysis due both chemical physical complexity. Their study by synchrotron-based X-ray microscopy techniques was made possible thanks recent developments carried out at ID21 beam line (European Synchrotron...
This paper describes a protocol for quantification of heritage copper alloys by energy‐dispersive X‐ray fluorescence spectroscopy (ED‐XRF). The protocol, nicknamed CHARMed PyMca, is designed users who wish to maximize inter‐laboratory reproducibility quantitative ED‐XRF results the wide range found in materials. By maximizing reproducibility, this should facilitate collaboration and allow rigorous use shared data databases. uses free, open‐source, fundamental parameters software called...
Abstract With the discovery of bona fide extraterrestrial materials in Stardust Interstellar Dust Collector, NASA now has a fundamentally new returned sample collection, after Apollo, Antarctic meteorite, Cosmic Dust, Genesis, Cometary, Hayabusa, and Exposed Space Hardware samples. Here, companion papers this volume, we present results from Preliminary Examination ( ISPE ). We found two tracks aerogel whose trajectories morphology are consistent with an origin interstellar dust stream,...
A nonproprietary software package, "PyMca", primarily developed for X-ray fluorescence analysis offers an easy-to-use interface calculating maps, by integrating intensity (of fluorescence, as well any spectral data) over Regions Of Interest (ROI), performing per pixel operations or applying multivariate analysis. Here we show that, while initially to analyze hyperspectral two-dimensional (spatial) this tool can be beneficial anyone interested in measuring variations one two dimensions, these...
X-ray absorption spectroscopy at the Mn K-edge has been performed on multilayers of photosystem II-enriched fragments native thylakoid membrane prepared from a higher plant (spinach) and unicellular green alga (Scenedesmus obliquus). Spectra collected for various angles between prevailing orientation normal electric field vector contain information atomic structure tetranuclear manganese complex II (PS II) its with respect to normal. The previously used approach evaluation dichroism extended...
Abstract At Echassières (Allier, France), arsenic speciation was determined in a soil developed over micaschist where Hercynian hydrothermal mineralization, including arsenopyrite FeAsS and löllingite FeAs2, has lead to regional As anomaly. The overlying soils which have from long term weathering exhibit levels as high 900 ppm the richest area, saprolite contains up 5200 As. Analysis by powder XRD, μ-X-ray diffraction on 20μm scale, SEM-EDS electron micro-probe analyses revealed that As,...
Abstract On the basis of an interstellar dust model compatible with Ulysses and Galileo observations, we calculate predict trajectories ( ISD ) in solar system distribution impact speeds, directions, flux particles on Stardust Interstellar Dust Collector during two collection periods mission. We find that expected velocities are generally low (<10 km s −1 for ratio radiation pressure force to gravitational β > 1, some will cometary side collector. If assume astronomical silicates...