Nejdůležitější odborné publikace vydané během prvního období (do 31. března 2019). Seznam všech publikací výzkumného programu APPLICATIONS vydaných v rámci projektu CAAS najdete v předchozím příspěvku.
Mediaeval metal threads and their identification using micro-XRF scanning, confocal XRF, and X-ray micro-radiography
M. Hložek, T. Trojek, R. Prokeš, V. Linhart
Radiation Physics and Chemistry, Volume 155, February 2019, Pages 299-303
Fabrics with metal threads were discovered in mediaeval well during excavations in the Mečová 2 Street in Brno. These are thin braids woven of metal threads using a small loom and sewed together into a broader strip. The textile materials are in a relatively good state, because the environment of the well preserved organic materials (fabrics, leather, wood). Furthermore, the positive effect of metal corrosion on the preservation of organic parts of the fabric occurred here. If metal threads are found in graves or dwelling backfills, only spiral-shaped metal fragments with microscopic relics of organic fibers are preserved. Based on microphotographs, we assume that metal threads were made by cutting or scissoring thin strips of metal sheets. The strips were spirally wound on a textile thread. The excavated fabric was deposited in a museum collection storage room for 20 years unnoticed, because its surface was covered with a layer of sediment and corrosion products. During the systematic research of mediaeval fabrics from Brno, it was found out that relics of gold are present in the ends of some of the threads. The fabrics were examined by non-destructive analytical methods. Metal threads covered with sediment and corrosion products were studied using X-ray fluorescence and radiography methods. The concentrations of elements in the individual layers show that the centre of the metal thread is formed by a silver strip. A thin layer of gold was laid on the silver strip. Silver was alloyed with copper, which corrosion products covered the whole metal strip and solidified the layer of sediments in the surface. XRF elemental mapping was employed to find out whether the metal threads pass through the whole braid. The results show that the braids are composed of silver threads with gold deposited on their rims and some central parts only.
Investigation of color layers of Bohemian panel paintings by confocal micro-XRF analysis
Radek Prokeš, Václava Antušková, Radka Šefců, Tomáš Trojek, Štěpánka Chlumská, Tomáš Čechák
Radiation Physics and Chemistry, Volume 151, October 2018, Pages 59-64
Confocal micro X-ray fluorescence spectroscopy (confocal micro-XRF) has recently become a significant instrumental method for analyses of cultural heritage as it provides depth-resolved information on elemental distribution of the investigated samples. This work describes results of confocal micro-XRF analyses of paint layers of two Bohemian panel paintings from the half of the 15th century that are part of the collections of the National Gallery in Prague. All the measurements were performed using a table top confocal micro-XRF setup designed at the Czech Technical University in Prague. A depth-profiling was used for investigation of red and blue paint layers in order to compare the composition and structure of the used pigments. Obtained results were compared with findings from the material survey on the sample taken from the painting Assumpta from Deštná (ca 1450, inv. no. O 724) to verify their origin in the same workshop. Confocal micro-XRF provides satisfactory data to specify the art workshop.
Tissue-equivalence of 3D-printed plastics for medical phantoms in radiology
J. Solca, T. Vrba, L. Burianova
Journal of Instrumentation, Volume 13, September 2018, Published 20 September 2018
The paper describes measurement of the linear attenuation coefficients for 59.5 keV, 122.0 keV and 344.5 keV photons and Hounsfield units for 80 kVp and 120 kVp computed tomography imaging of a large set of commercially 3D-printed test samples of different plastic materials aiming to provide a basis for a selection of a suitable and available material for 3D printing of medical phantoms used in radiology, and specifically for imaging in targeted radionuclide therapy. The results were compared to ICRU44 skeletal muscle and adipose tissues. The results also showed large differences between photon attenuation properties of the same type of plastic material printed by different companies on different printers using filaments from different manufacturers. As a result, it is highly recommended to print a medical phantom on the same printer, with the same settings, and with the same filament as the test sample.