Development of the materials analysis and particle probe for Proto-MPEX

The goal of the work was to develop a concept of intensification of mining operations, taking into account geomechanical processes occurring in the “rock massif – mining workings – support and protective structures” system. The article is the result of theoretical and experimental research materials analysis and synthesis, carried out for the conditions of coal, non-metallic and iron-ore mines. Positive and negative geomechanical processes and phenomena, occurring during intensification of mining operations, have been substantiated. A set of technical and technological solutions to eliminate the negative phenomena associated with high mining rates development of mineral resources has been proposed. Recommendations, presented in this article, will significantly reduce the conditionally fixed costs of mining production and improve miner’s safety.

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Integrated quantitative PIXE analysis and EDX spectroscopy using a laser-driven particle source

Science Advances ◽

10.1126/sciadv.abc8660 ◽

2021 ◽

Vol 7 (3) ◽

pp. eabc8660

Author(s):

F. Mirani ◽

A. Maffini ◽

F. Casamichiela ◽

A. Pazzaglia ◽

A. Formenti ◽

...

Keyword(s):

Experimental Investigation ◽

Materials Science ◽

Quantitative Information ◽

Pixe Analysis ◽

Materials Analysis ◽

Particle Source ◽

X Ray ◽

Analysis Techniques ◽

Sample Structure ◽

Elemental Characterization

Among the existing elemental characterization techniques, particle-induced x-ray emission (PIXE) and energy-dispersive x-ray (EDX) spectroscopy are two of the most widely used in different scientific and technological fields. Here, we present the first quantitative laser-driven PIXE and laser-driven EDX experimental investigation performed at the Centro de Láseres Pulsados in Salamanca. Thanks to their potential for compactness and portability, laser-driven particle sources are very appealing for materials science applications, especially for materials analysis techniques. We demonstrate the possibility to exploit the x-ray signal produced by the co-irradiation with both electrons and protons to identify the elements in the sample. We show that, using the proton beam only, we can successfully obtain quantitative information about the sample structure through laser-driven PIXE analysis. These results pave the way toward the development of a compact and multifunctional apparatus for the elemental analysis of materials based on a laser-driven particle source.

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Does substrate colour affect the visual appearance of gilded medieval sculptures? Part II: SEM–EDX observations on gold leaf samples taken from medieval wooden sculptures

Heritage Science ◽

10.1186/s40494-020-00456-2 ◽

2020 ◽

Vol 8 (1) ◽

Author(s):

Qing Wu ◽

Max Döbeli ◽

Tiziana Lombardo ◽

Katharina Schmidt-Ott ◽

Benjamin Watts ◽

...

Keyword(s):

Rutherford Backscattering Spectrometry ◽

Substrate Type ◽

Surface Appearance ◽

Late Medieval ◽

Visual Appearance ◽

Materials Analysis ◽

Gold Leaf ◽

X Ray ◽

Technical Specifications ◽

Peak Value

AbstractIn the previous paper (Part I), the colorimetry and interferometric microscopy measurements on modern gold leaf models have revealed that the visual appearance of a gilded surface, both burnished and unburnished, depends strongly on the substrate type, surface roughness and texture, but not on the colour of the substrate. In this second part, we investigate the materials compositions and technical specifications of medieval gold leaf through combining literature sources and materials analysis such as scanning electron microscopy coupled with energy dispersive X-ray analysis (SEM–EDX) on samples taken from gilded wooden sculptures. Our study shows that the late medieval gold leaf has a high purity of about 23.7 carat and has an average thickness of 160 nm (with a peak value of 138 nm), purer and thicker than the modern gold leaves studies in Part I. Supportive Rutherford backscattering spectrometry (RBS) measurements on gilded models confirms the accuracy and reliability of the SEM–EDX observations on the medieval gold leaf samples. We additionally present observations of a rarely recorded special variant of medieval gold leaf—“fine reinforced gold leaf”. Combined with the findings from Part I, we conclude that light penetrating the medieval gold leaf and reflected from the gilding substrate could not be a significant, or even perceptible contribution to the visual appearance of the gilding. We argue that the misconception surrounding the correlation between the substrate colour and the gilded surface appearance can be attributed to the historical development of gilding and polychromy technologies.

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