scholarly journals HR 3D Element Distribution by SR-Xrf Tomography of CM2 Material as Analog for Material Returned in Hayabusa2

2020 ◽  
Author(s):  
B. J. Tkalcec ◽  
P. Tack ◽  
Frank E. Brenker ◽  
Ella De Pauw ◽  
Bart Vekemans ◽  
...  
Keyword(s):  
Element Distribution ◽  
Sr Xrf

Investigation of element distribution between components of a salt-lake system by SR-XRF

2012 ◽  
Vol 6 (6) ◽  
pp. 1009-1018 ◽  
Author(s):  
E. V. Lazareva ◽  
A. V. Bryanskaya ◽  
O. P. Taran ◽  
Yu. P. Kolmogorov ◽  
T. K. Malup ◽  
...  
Keyword(s):  
Salt Lake ◽  
Element Distribution ◽  
Lake System ◽  
Sr Xrf

Electron spectroscopic imaging (ESI) on multiphase polymer materials

1989 ◽  
Vol 47 ◽  
pp. 348-349
Author(s):  
H.-J. Cantow ◽  
M. Kunz ◽  
M. Möller
Keyword(s):  
Energy Loss ◽  
Melt Spinning ◽  
Chromatic Aberration ◽  
Element Distribution ◽  
Polymer Materials ◽  
Specific Energy Loss ◽  
Transmission Electron ◽  
Multicomponent Polymer ◽  
Diffraction Patterns ◽  
Image Planes

In transmission electron microscopy the natural contrast of polymers is very low. Thus the contrast has to be enhanced by staining with heavy metals. The resolution is limited by the size of the staining particles and by the fact that electrons with different energy are focused in different image planes due to the chromatic aberration of the magnetic lenses. The integration of an electron energy loss spectrometer into the optical coloumn of a transmission electron microscope offers the possibility to use monoenergetic electrons and to select electrons with a certain energy for imaging. Thus contrast and resolution are enhanced. By imaging only electrons with an element specific energy loss the element distribution in the sample can be obtained. In addition, elastic bright field images and diffraction patterns yield excellent resolution. Some applications of the method on multicomponent polymer materials are discussed.Bulk polymer samples were prepared by ultramicrotoming at room temperature or well below the glass transition temperature. Very thin films for the direct observation of the structure in semicrystalline polymers were obtained by melt-spinning. Specimens were examined with a ZEISS CEM 902 operated at 80 kV.

Methylmercury and Trace Element Distribution in the Organs of Stenella coeruleoalba Dolphins Stranded on the French Mediterranean Coast

2014 ◽  
Vol 8 (1) ◽  
pp. 35-48 ◽  
Author(s):  
Emmanuel Wafo ◽  
Véronique Risoul ◽  
Thérèse Schembri ◽  
Véronique Lagadec ◽  
Frank Dhermain ◽  
...  
Keyword(s):  
Trace Elements ◽  
Trace Element ◽  
Marine Pollution ◽  
Element Distribution ◽  
Mediterranean Coast ◽  
Trace Element Distribution ◽  
Slight Reduction ◽  
Stenella Coeruleoalba ◽  
Contamination Levels

The main objective of this study was to evaluate the contamination by mercury (Hg), methylmercury (Me-Hg), cadmium (Cd), selenium (Se), zinc (Zn), copper (Cu), iron (Fe) and manganese (Mn) in dolphins stranded on the French Mediterranean coast. The distributions of these contaminants in the organs of dolphins have also been studied. Overall, contamination levels varied according to the following sequence: liver > kidney > lung > muscle, except for cadmium (kidney > liver > lung > muscle). Size and sex of animals were also considered. Young dolphins were less impacted with trace elements than adults, except for copper. Among the studied parameters, the most important appeared to be the size of mammals. In addition, in the case of mercury and selenium, the sex of mammals seemed to be also relevant. The correlations between the concentrations of trace elements suggest the existence of detoxification processes. Since 1990s, using dolphins for tracing marine pollution, a slight reduction in the burden of the considered trace elements could be noted.

TRACE-ELEMENT DISTRIBUTION IN GIANT SPODUMENE CRYSTALS IN GRANITIC PEGMATITES FROM THE BLACK HILLS, SOUTH DAKOTA AND NEWRY, MAINE

2019 ◽  
Author(s):  
Stephan R. Hlohowskyj ◽  
◽  
Mona-Liza C. Sirbescu ◽  
James J. Student ◽  
Niels Hulsbosch ◽  
...  
Keyword(s):  
South Dakota ◽  
Trace Element ◽  
Element Distribution ◽  
Black Hills ◽  
Trace Element Distribution ◽  
Granitic Pegmatites

Minor-Element Distribution in Olivine

1970 ◽  
Vol 78 (3) ◽  
pp. 304-325 ◽  
Author(s):  
Tom Simkin ◽  
J. V. Smith
Keyword(s):  
Minor Element ◽  
Element Distribution

scholarly journals Microstructures and Macrosegregation of Al–Zn–Mg–Cu Alloy Billet Prepared by Uniform Direct Chill Casting

Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 708
Author(s):  
Li Zhou ◽  
Yajun Luo ◽  
Zhenlin Zhang ◽  
Min He ◽  
Yinao Xu ◽  
...  
Keyword(s):  
Mold Wall ◽  
Direct Chill ◽  
Element Distribution ◽  
Direct Chill Casting ◽  
Electromagnetic Stirring ◽  
Alloying Elements ◽  
Alloying Element ◽  
Casting Method ◽  
Chill Casting ◽  
Cu Alloy

In this study, large-sized Al–Zn–Mg–Cu alloy billets were prepared by direct chill casting imposed with annular electromagnetic stirring and intercooling; a process named uniform direct chill casting. The effects of uniform direct chill casting on grain size and the alloying element distribution of the billets were investigated and compared with those of the normal direct chill casting method. The results show that the microstructures were refined and the homogeneity of the alloying elements distribution was greatly improved by imposing the annular electromagnetic stirring and intercooling. In uniform direct chill casting, explosive nucleation can be triggered, originating from the mold wall and dendrite fragments for grain refinement. The effects of electromagnetic stirring on macrosegregation are discussed with consideration of the centrifugal force that drives the movement of melt from the central part towards the upper-periphery part, which could suppress the macrosegregation of alloying elements. The refined grain can reduce the permeability of the melt in the mushy zone that can restrain macrosegregation.

Influence of element distribution on mechanical properties in the bonding zone of explosively welded steels

2021 ◽  
Vol 199 ◽  
pp. 113860
Author(s):  
C. Borchers ◽  
J. Arlt ◽  
C. Nowak ◽  
F. Gärtner ◽  
M. Hammerschmidt ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Element Distribution ◽  
Bonding Zone

scholarly journals More than XRF Mapping: STEAM (Statistically Tailored Elemental Angle Mapper) a Pioneering Analysis Protocol for Pigment Studies

2021 ◽  
Vol 11 (4) ◽  
pp. 1446
Author(s):  
Jacopo Orsilli ◽  
Anna Galli ◽  
Letizia Bonizzoni ◽  
Michele Caccia
Keyword(s):  
Cultural Heritage ◽  
Element Distribution ◽  
Elemental Distribution ◽  
X Rays ◽  
Spectral Angle Mapper ◽  
X Ray ◽  
Fluorescence Radiation ◽  
Set Up ◽  
Non Destructive ◽  
Analysis Protocol

Among the possible variants of X-Ray Fluorescence (XRF), applications exploiting scanning Macro-XRF (MA-XRF) are lately widespread as they allow the visualization of the element distribution maintaining a non-destructive approach. The surface is scanned with a focused or collimated X-ray beam of millimeters or less: analyzing the emitted fluorescence radiation, also elements present below the surface contribute to the elemental distribution image obtained, due to the penetrative nature of X-rays. The importance of this method in the investigation of historical paintings is so obvious—as the elemental distribution obtained can reveal hidden sub-surface layers, including changes made by the artist, or restorations, without any damage to the object—that recently specific international conferences have been held. The present paper summarizes the advantages and limitations of using MA-XRF considering it as an imaging technique, in synergy with other hyperspectral methods, or combining it with spot investigations. The most recent applications in the cultural Heritage field are taken into account, demonstrating how obtained 2D-XRF maps can be of great help in the diagnostic applied on Cultural Heritage materials. Moreover, a pioneering analysis protocol based on the Spectral Angle Mapper (SAM) algorithm is presented, unifying the MA-XRF standard approach with punctual XRF, exploiting information from the mapped area as a database to extend the comprehension to data outside the scanned region, and working independently from the acquisition set-up. Experimental application on some reference pigment layers and a painting by Giotto are presented as validation of the proposed method.

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