![]() The assessment of this portable system was accomplished by comparing some of the compositions obtained in this work with the compositions obtained for the same coins with a fixed ED-XRF, as well as results from the literature on similar coins.ģThe base alloys were determined for coins struck during the Brasil Colônia period (from 1500 to independence, in 1822)and during the Dutch occupation (since the invasion of Bahia in 1624 to the insurrection of Pernambuco in 1654), as well as for Portuguese coins struck in Portugal during the reigns of Fernando I (1367 to 1383) and his successor João I (1383 to 1433). In the present work we used a handmade portable X-ray fluorescence system (pXRF) (Neiva et al., 2005 Appoloni et al., 2007) to analyse a set of gold, silver and billon coins from the collection of the Museu Histórico Nacional do Rio de Janeiro (MHN).ĢThe analyses were carried out in the Numismatic Department of the MHN, and the aim of the study was to test the possibilities and limitations of this portable system for the determination of the coins’ base alloys, and to verify whether the results obtained were consistent with historical facts. In situ experimental setups (Cesareo et al., 2007 Karydas, 2007) have been used to perform analyses in specific situations, such as in the case of large sculptures, frescos, paintings, etc., and to characterise metallic alloys, as well as several pigments. ![]() ![]() Haut de pageġAmong the analytical techniques used in the studies of cultural heritage objects, energy dispersive X-ray fluorescence (ED-XRF) is a very versatile one due to its portable configuration allowing in situ measurements. Les monnaies appartenant à la période Brasil Colônia sont constituées de 80,5 % d’or et de 96,8 % d’argent et les monnaies frappées au Portugal montrent une dévaluation sous Jean I. Le but de ce travail est double : vérifier les possibilités et les limites de ce système portable lors qu’il s’agit de déterminer les alliages constitutifs de monnaies en métal précieux et vérifier les rapports entre l’évolution des compositions des monnaies et les différents faits historiques. Le montage expérimental est constitué d’un mini détecteur Si-PIN et d’une source radioactive de 238Pu, dont la radiation émise est utilisée comme source d’excitation. Certaines de ces monnaies ont été frappées au Brésil pendant la période Brasil Colônia et sous l’occupation hollandaise, alors que d’autres ont été frappées au Portugal sous les règnes de Ferdinand I (1367-1383) et de son successeur Jean I (1383-1433). Any promotions or discounts are applied to the premium above the precious metal price only and not on the metal price itself.Un équipement portable à fluorescence X (pFX) a été utilisé pour l’analyse de monnaies en or, en argent et en billon appartenant à la collection du Museu Histórico Nacional de Rio de Janeiro (MHN). * Bullion product prices displayed include the precious metal price and any applicable premium. Historic financial performance of Bullion is not indicative of and does not guarantee future financial performance. ![]() Investments in Bullion should only be made as part of a diversified investment portfolio and investment advice should be sought before any investment is made. You should carefully consider the risks associated with investing in Bullion, taking into account your own individual financial needs and circumstances. Before making any investment decision, you may wish to seek advice from your financial, legal, tax and accounting advisers. As such, investments in Bullion involve a degree of risk, which may make them unsuitable for certain persons. Bullion markets can be volatile and the value of Bullion may fluctuate dependent on the market value of precious metals. Please note that certain products, storage and delivery services will be dependent on the type of account you hold. All information contained on or available through this website is for general information purposes only and does not constitute investment advice.
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