Browsing by Author "Figueiredo, M. Ondina"
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- An approach to the binding state of indium in natural chalcogenides through the analysis of In L3 edge XANES spectraPublication . Silva, Teresa; de Oliveira, Daniel Pipa Soares; Veiga, JP; Rosa, Diogo; Figueiredo, M. OndinaA study using synchrotron radiation X-ray absorption spectroscopy at In L3-edge is presented, as a contribution to interpret the binding state of indium in natural chalcogenides considering the increase of applications of this scarce metal.
- An X-ray spectrometry and absorption spectroscopy study of blue-and-white glazes from ancient Chinese porcelains [Abstract]Publication . Figueiredo, M. Ondina; Silva, Teresa; Veiga, JP
- Análise expedita de U e de razões Zr/Rb em solos e relação com a componente geológica na região de Nisa-Castelo de Vide, PortugalPublication . Prazeres, Cátia; Batista, Maria Joao; Silva, Teresa; Figueiredo, M. Ondina
- Ancient Chinese blue-and-white porcelain glazes : can we measure the oxidation state of cobalt through X-ray absorption spectroscopy?Publication . Figueiredo, M. Ondina; Silva, Teresa; Veiga, JP
- Ancient glazed ceramic tiles : a long-term, study from the remediation of environmental impacts to the non-destructive characterization of materialsPublication . Figueiredo, M. Ondina; Silva, Teresa; Veiga, JPSince the involvement in a national research project in 1995-1997 with the partnership of the National Tile Museum in Lisbon, until a recent European project with partners from Mediterranean countries which cultural patrimony entails glazed ceramic tiles, the authors have been active in the non-destructive characterization of ceramic and vitreous materials used to manufacture ancient decorated tiles (16th-19th century) through the access to the European Synchroton Research Facility (ESRF, Grenoble/France). As an input to the preservation of this important cultural patrimony through the improvement of restoration techniques, a synopsis is presented of the work so far developed.
- Ascertaining the degradation state of ceramic tiles : a preliminary non-destructive step in view of conservation treatmentsPublication . Silva, Teresa; Figueiredo, M. Ondina; Prudêncio, Maria IsabelConserving the cultural heritage is a general concern and the use of non-destructive techniques to characterize ancient materials is important. Serious deterioration effects in environmentally exposed ancient glazed ceramic tiles arise from the development of micro-organisms (algae/fungi) within the pore system. Subsequent biodegradation processes are particularly harmful once the decorated glaze is damaged by exfoliation/detachment. Three case studies will be addressed: Portuguese polychrome decorated tiles from the interior of two churches (16th–17th century) and from the outdoor of a Palace (18th century). Small tile fragments were directly irradiated in a wavelength-dispersive X-ray fluorescence spectrometer for glaze chemical characterization and subsequently irradiated in a powder diffractometer to assess the phase constitution of both glaze and ceramic body. Cleaning and conserving these ancient cultural artifacts involve a decontamination process applying innovative non-destructive techniques. The present work is intended as a contribution to diagnose the actual degradation state of ancient tiles in view of future decontamination actions using gamma radiation.
- Ascertaining the degradation state of ceramic tiles : a preliminary non-destructive step in view of conservation treatments using gamma radiationPublication . Silva, Teresa; Figueiredo, M. Ondina; Prudêncio, Maria Isabel
- Blue pigments in XVI-XVII century glazes : a comparative study between portuguese faiences and chinese porcelainsPublication . Figueiredo, M. Ondina; Silva, Teresa; Veiga, JP; Prudêncio, Maria Isabel; Dias, Maria Isabel; Matos, M. A.; Pais, A. M.
- Blue pigments in XVI-XVII century glazes : a comparative study between portuguese faiences and contemporary chinese porcelains manufactured for portuguese marketPublication . Figueiredo, M. Ondina; Silva, Teresa; Veiga, JP; Prudêncio, M. Isabel; Dias, M. Isabel; Matos, Maria Antónia; Pais, Alexandre Manuel
- Chromophore behaviour of iron, copper, cobalt and antimony in ancient tile, faience and porcelain glazes plus archaeological glass beads : an overview on X-ray absorption near-edge spectroscopy studiesPublication . Figueiredo, M. Ondina; Veiga, JP; Silva, Teresa