scholarly journals Visualizing mineralization processes and fossil anatomy using synchronous synchrotron X-ray fluorescence and X-ray diffraction mapping

2020 ◽  
Author(s):  
Pierre Gueriau ◽  
Solenn Réguer ◽  
Nicolas Leclercq ◽  
Camila Cupello ◽  
Paulo M. Brito ◽  
...  
Keyword(s):  
Cross Sections ◽  
Soft Tissues ◽  
Imaging Techniques ◽  
Local Strain ◽  
Phase Identification ◽  
X Ray Diffraction ◽  
X Ray ◽  
Area Detector ◽  
Exceptional Preservation ◽  
Mineralization Processes

Paleontologists have always tested, used and developed cutting edge imaging techniques to produce the most complete and accurate descriptions of their fossils. Nowadays, efforts are largely driven by taphonomic studies, especially those investigating the exceptional preservation of organic molecules or soft tissues, leading to a series of developments towards molecular and elemental imaging. Paradoxically, although fossils are mostly mineralized materials only the latter is commonly used to infer their mineral composition, but X-ray diffraction, which specifically provides phase identification, received little attention. Here, we show the use of synchrotron radiation to generate, synchronously to X-ray fluorescence major-to-trace elemental maps, megapixel mineralogical maps in transmission geometry using a two-dimensional area detector placed behind the fossil. This approach was applied to millimeter-thick cross-sections prepared through three-dimensionally preserved fossils, as well as to flat fossils. It allows for mineral phases identification (benefitting from the elemental information collected synchronously) and localization at the microscale over centimetric lateral size objects, and further gives information on texture (preferential orientation), crystallites size and local strain, showing great potential for taphonomic studies, as well as other poorly understood (bio)mineralization processes in environmental sciences. We also illustrate that mineralogical contrasts between fossil tissues and/or the encasing sedimentary matrix can be used to visualize hidden anatomies in fossils.

scholarly journals Visualizing mineralization processes and fossil anatomy using synchronous synchrotron X-ray fluorescence and X-ray diffraction mapping

2020 ◽  
Vol 17 (169) ◽  
pp. 20200216 ◽  
Author(s):  
Pierre Gueriau ◽  
Solenn Réguer ◽  
Nicolas Leclercq ◽  
Camila Cupello ◽  
Paulo M. Brito ◽  
...  
Keyword(s):  
Cross Sections ◽  
Soft Tissues ◽  
Local Strain ◽  
Phase Identification ◽  
X Ray Diffraction ◽  
X Ray ◽  
Area Detector ◽  
Transmission Geometry ◽  
Mineralization Processes ◽  
Elemental Data

Fossils, including those that occasionally preserve decay-prone soft tissues, are mostly made of minerals. Accessing their chemical composition provides unique insight into their past biology and/or the mechanisms by which they preserve, leading to a series of developments in chemical and elemental imaging. However, the mineral composition of fossils, particularly where soft tissues are preserved, is often only inferred indirectly from elemental data, while X-ray diffraction that specifically provides phase identification received little attention. Here, we show the use of synchrotron radiation to generate not only X-ray fluorescence elemental maps of a fossil, but also mineralogical maps in transmission geometry using a two-dimensional area detector placed behind the fossil. This innovative approach was applied to millimetre-thick cross-sections prepared through three-dimensionally preserved fossils, as well as to compressed fossils. It identifies and maps mineral phases and their distribution at the microscale over centimetre-sized areas, benefitting from the elemental information collected synchronously, and further informs on texture (preferential orientation), crystallite size and local strain. Probing such crystallographic information is instrumental in defining mineralization sequences, reconstructing the fossilization environment and constraining preservation biases. Similarly, this approach could potentially provide new knowledge on other (bio)mineralization processes in environmental sciences. We also illustrate that mineralogical contrasts between fossil tissues and/or the encasing sedimentary matrix can be used to visualize hidden anatomies in fossils.

scholarly journals Radiographic and Computed Tomographic Anatomy of the Donkey Carpus

2019 ◽  
Vol 36 (03) ◽  
pp. 145-155
Author(s):  
Mohamed A.M. Alsafy ◽  
Mahmoud H. El-Kammar ◽  
Samir R. Nouh ◽  
Howaida M. Abou-Ahmed ◽  
William Perez ◽  
...  
Keyword(s):  
Cross Sections ◽  
Soft Tissues ◽  
Imaging Techniques ◽  
Ct Scans ◽  
Full Description ◽  
Cross Sectional ◽  
X Ray ◽  
Computed Tomographic ◽  
Carpal Joint ◽  
The Cost

Introduction Joint diseases represent most of the musculoskeletal disorders. Therefore, the aim of the current study was to make a radiographic and computed tomographic analysis of the structures of the donkey carpus and investigate carpal joint affections. Materials and Methods The study was performed with the use of cross-sectional anatomy, digital X-ray and computed tomography (CT) scans. Twelve adult donkeys were used. Results The results provide a full description of the bones and soft tissues of the carpus. The carpal joint was examined at many levels using different CT and X-ray planes. The carpus was studied through bone and soft-tissue windows that were compared with cadaver cross-sections for interpretation. The study revealed some joint affections that were detected by the CT scans but were unapparent in X-ray films, such as bony cysts, hemorrhagic bony cysts, old and microfractures, and bony sclerosis. Some normal anatomic variants were recorded during the examination of the CT scans to assist the equine practitioners that deal with the carpal joints of donkeys. Conclusion Both imaging techniques are suitable for the examination of the carpus, and the selection of the technique is conditioned to many factors, like the type of tissue affected and economic reasons, such as the availability of the apparatus and the cost of the animal.

scholarly journals Local Strain Distribution in ZnO Microstructures Visualized with Scanning Nano X‐Ray Diffraction and Impact on Electrical Properties

2021 ◽  
pp. 2100201
Author(s):  
Philipp Jordt ◽  
Stjepan B. Hrkac ◽  
Jorit Gröttrup ◽  
Anton Davydok ◽  
Christina Krywka ◽  
...  
Keyword(s):  
Electrical Properties ◽  
Strain Distribution ◽  
Local Strain ◽  
X Ray Diffraction ◽  
X Ray

scholarly journals An Insight into Chemistry and Structure of Colloidal 2D-WS2 Nanoflakes: Combined XPS and XRD Study

Nanomaterials ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1969
Author(s):  
Riccardo Scarfiello ◽  
Elisabetta Mazzotta ◽  
Davide Altamura ◽  
Concetta Nobile ◽  
Rosanna Mastria ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Xrd Analysis ◽  
Crystal Habit ◽  
Phase Identification ◽  
X Ray Diffraction ◽  
X Ray ◽  
Morphological Evaluation ◽  
Rational Understanding ◽  
Structural Inspection

The surface and structural characterization techniques of three atom-thick bi-dimensional 2D-WS2 colloidal nanocrystals cross the limit of bulk investigation, offering the possibility of simultaneous phase identification, structural-to-morphological evaluation, and surface chemical description. In the present study, we report a rational understanding based on X-ray photoelectron spectroscopy (XPS) and structural inspection of two kinds of dimensionally controllable 2D-WS2 colloidal nanoflakes (NFLs) generated with a surfactant assisted non-hydrolytic route. The qualitative and quantitative determination of 1T’ and 2H phases based on W 4f XPS signal components, together with the presence of two kinds of sulfur ions, S22− and S2−, based on S 2p signal and related to the formation of WS2 and WOxSy in a mixed oxygen-sulfur environment, are carefully reported and discussed for both nanocrystals breeds. The XPS results are used as an input for detailed X-ray Diffraction (XRD) analysis allowing for a clear discrimination of NFLs crystal habit, and an estimation of the exact number of atomic monolayers composing the 2D-WS2 nanocrystalline samples.

Polyhedral characteristics of the cosalite-type crystal structures

2019 ◽  
Vol 57 (5) ◽  
pp. 647-662
Author(s):  
Sabina Kovač ◽  
Predrag Dabić ◽  
Aleksandar Kremenović ◽  
Aleksandar Pačevski ◽  
Ljiiljana Karanović ◽  
...  
Keyword(s):  
Crystal Data ◽  
Chemical Formula ◽  
X Ray Diffraction ◽  
Orthorhombic Space Group ◽  
X Ray ◽  
Area Detector ◽  
Octahedral Sites ◽  
Distorted Octahedral ◽  
Cation Substitutions ◽  
Type Crystal

Abstract The crystal structure of cosalite from the Trepča orefield was refined in the orthorhombic space group Pnma [a = 23.7878 (9), b = 4.0566 (3), c = 19.1026 (8) Å, V = 1843.35 (17) Å3, Z = 2] from single-crystal data (MoKα X-ray diffraction, CCD area detector) to the conventional R1 factor 0.031 for 1516 unique reflections with I > 2σ(I). The chemical formula (Cu0.15Ag0.24)+(Fe0.19Pb7.20)2+(Bi7.06Sb1.06)3+S20, calculated on the basis of 20 S atoms per formula unit, was determined by WDX. The unit cell contains 18 + 2 symmetrically nonequivalent atomic sites: 10 occupied by S; two by pure Pb (Pb3 and Pb4); one by pure Bi (Bi1); two by a combination of Bi and small amounts of Sb (Bi2/Sb2, Bi4/Sb3); two by Pb and Bi, and in one of these also by a small amount of Ag [Me1 = Pb2 >> Bi5 > Ag1, Me3 = Pb1 >> Bi3]; and finally one site, Me2 (Bi6 >> □), is partly occupied by Bi and partly split into an additional two adjacent trigonal planar “interstitial positions”, Cu1 and Cu2, where small amounts of Cu, Ag, and Fe can be situated. All atoms are at 4c special positions at y = 0.25 or 0.75. The structure consists of slightly to moderately distorted MeS6 octahedra sharing edges, bicapped trigonal PbS8 coordination prisms, and fairly distorted Cu1S6 and Cu2S4 polyhedra. The effects of the cation substitutions, bond valence sums, and the polyhedral characteristics are compared with other published cosalite-type structures. Among known cosalite-type structures, the largest volume contraction is shown by sample 4 (Altenberg) and involves the replacement of large cations (Bi3+ and Pb2+) by the smaller Sb3+, as well as Cu+ and Ag+. These replacements are reflected in the variations of individual Me–S bond distances, which are accompanied by variations in average Me–S distances. The degree of polyhedral distortion, Δ, progressively increases for the four Bi-hosting sites of nine cosalite-type structures: Me2 < Bi2 < Bi1 < Bi4. The Bi4 and Me3 are the most and the Me1 and Me2 are the least distorted octahedral sites of the nine cosalite-type structures.

Full-field X-ray diffraction microscopy using polymeric compound refractive lenses

2014 ◽  
Vol 47 (6) ◽  
pp. 1882-1888 ◽  
Author(s):  
J. Hilhorst ◽  
F. Marschall ◽  
T. N. Tran Thi ◽  
A. Last ◽  
T. U. Schülli
Keyword(s):  
Imaging Techniques ◽  
Light And Electron Microscopy ◽  
Added Value ◽  
Acquisition Time ◽  
Imaging Method ◽  
X Ray Diffraction ◽  
Polymeric Compound ◽  
Full Field ◽  
X Ray ◽  
Diffraction Imaging

Diffraction imaging is the science of imaging samples under diffraction conditions. Diffraction imaging techniques are well established in visible light and electron microscopy, and have also been widely employed in X-ray science in the form of X-ray topography. Over the past two decades, interest in X-ray diffraction imaging has taken flight and resulted in a wide variety of methods. This article discusses a new full-field imaging method, which uses polymer compound refractive lenses as a microscope objective to capture a diffracted X-ray beam coming from a large illuminated area on a sample. This produces an image of the diffracting parts of the sample on a camera. It is shown that this technique has added value in the field, owing to its high imaging speed, while being competitive in resolution and level of detail of obtained information. Using a model sample, it is shown that lattice tilts and strain in single crystals can be resolved simultaneously down to 10−3° and Δa/a= 10−5, respectively, with submicrometre resolution over an area of 100 × 100 µm and a total image acquisition time of less than 60 s.

scholarly journals Cryogenic Coherent X-ray Diffraction Imaging Techniques for Structural Analyses of Biological Cells and Cellular Organelles

2018 ◽  
Vol 24 (S2) ◽  
pp. 14-15
Author(s):  
Amane Kobayashi ◽  
Yuki Takayama ◽  
Tomotaka Oroguchi ◽  
Koji Okajima ◽  
Mao Oide ◽  
...  
Keyword(s):  
Imaging Techniques ◽  
Biological Cells ◽  
X Ray Diffraction ◽  
X Ray ◽  
Diffraction Imaging ◽  
Cellular Organelles

Diffraction

2012 ◽  
Vol 20 (2) ◽  
pp. 7-7
Author(s):  
Charles Lyman
Keyword(s):  
Electron Diffraction ◽  
100Th Anniversary ◽  
Primary Phase ◽  
Phase Identification ◽  
X Rays ◽  
X Ray Diffraction ◽  
Identification Methods ◽  
X Ray ◽  
Structure Of Matter

This year marks the 100th anniversary of the discovery of X-ray diffraction and the 85th anniversary of electron diffraction (see Microscopy Pioneers). For most of the time since their introduction, microscopists have known these two techniques as the primary phase identification methods used in conjunction with various microscopies. However, these two diffraction methods also have played enormous roles in understanding the structure of matter, as well as the nature of both X rays and electrons.

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