Search results for "XRF"
showing 10 items of 106 documents
A degradation study of XVIII century graffiti on the walls of Chiaramonte Palace (Palermo, Italy)
2009
NDT for the detection and characterization of superficial treatments on stone material from archaeological sites of Merida (Spain)
2014
Confronto XRF – LIBS per la caratterizzazione chimico-fisiche dei materiali lapidei provenienti dal teatro greco-romano di Taormina
2008
Vengono messe a confronto due tecniche spettroscopiche, la fluorescenza a raggi X (XRF) e la ablazione indotta da laser pulsato (LIBS), al fine di caratterizzare la composizione chimico-fisica di materiali lapidei naturali e non provenienti dal teatro Greco-Romano di Taormina. Entrambe le tecniche permettono un’analisi integrata, offrendo la LIBS la possibilità di ottenere informazioni stratigrafiche. Verranno presentati i risultati di analisi XRF e LIBS effettuate in situ e in laboratorio sui campioni prelevati nel teatro. L’interpretazione quantitativa delle analisi LIBS è stata effettuata mediante una tecnica standarless, ossia che non richiede l’uso di standard e denominata tecnica Cali…
Reconsidering the accuracy of X-ray fluorescence and ion beam based methods when used to measure the thickness of ancient gildings
2017
Since at least 5000 years ago, gilding techniques have been used for decoration purposes or to make artefacts appear as made of solid gold. Investigation of ancient gildings inevitably requires measuring their thickness, which is usually done either through the observation of cross-sections or by methods such as Rutherford backscattering spectroscopy, particle-induced X-ray emission and X-ray fluorescence. Whereas the former method requires sampling, the latter ones are non-invasive and therefore preferable. These non-invasive methods, however, measure the number of atoms per unit area, which can be converted into thickness only if the density is known. So far this has not been considered a…
Food and Environment: Trace Element Content of Hen Eggs from Different Housing Types
2013
AbstractEleven trace elements (Ba, Cu, Fe, Mn, Ni, Pb, Rb, Se, Sr, V, Zn) were quantitatively determined in hen egg samples collected from different poultry housing types (large-scale poultry farms, organic farms and domestic farms) over the territory of Latvia. Samples were wet digested and quantitatively analysed by total reflection X-ray fluorescence spectrometry (TXRF). The accuracy of analytical method was verified with analysis of certified reference material NCS ZC73017 (GSB-10)-Apple. The most variable range of concentrations and the highest content of elements were determined for hen egg samples derived from organic farms, while egg samples from domestic farms and poultry farms mos…
Sulfonēšanas pakāpes noteikšana sulfurētiem poli(ēter ēter ketoniem)
2017
Sulfonēšanas pakāpes noteikšana sulfurētiem poli(ēter ēter ketoniem). Sproģe D., zinātniskais vadītājs Asoc. prof. Dr. Ķīm. Guntars Vaivars. Kursa darbs, 40 lappuses, 19 attēli, 12 tabulas, 28 literatūras avoti, 3 pielikumi. Latviešu valodā. Darbā tiek pētīta PĒĒK sulfurēšanas reakcijas kinētika istabas un 35°C grādu temperatūrā. Paņemtajiem paraugiem, tika aprēķinātas sulfonēšanas pakāpes izmantojot rezultātus, kuri tika iegūti ar titrimetrijas metodi, ar viļņu dispersijas rentgenfluorescences spektrometru un TGA-DTA. Mērot ar WD-XRF metodi tika veikta standartpiedevu metode un mainīti analizējamā parauga diametrs.