14 documents found, page 1 of 2
Study of Mural Paintings Using In Situ XRF, Confocal Synchrotron-m-XRF, m-XRD, ...
Valadas, S.; Candeias, A.E.; Mirão, J.; Tavares, D.; Coroado, J.; Simon, R.; Silva, A.S.; Gil, M.; Guilherme, A.; Carvalho, M.L.In this work, we present the results of an analytical method developed for detailed pigment identification, stratigraphy, and degradation of the paint layers of mural paintings applied in the study of the 17th century frescoes from the Misericordia Church of Odemira ~Southwest Portugal!. In situ X-ray fluores- cence spectrometry analyses were performed on three panels of the mural paintings and complemented by ...
Limewashing paintings in Alentejo urban heritage: pigment characterization and ...
Gil, M.; Carvalho, M.L.; Seruya, A.; Queralt, I.; Candeias, A.E.; Mirao, J.Pigments used in traditional limewashing paintings in Alentejo urban Heritage are inorganic materials and can be grouped into four categories: a) reds – red ochre (from terras rossas, red schists and iron ore deposits weathering), almagres,terra roxa (natural processed red ochres) and synthetic red iron oxides; b) yellows – yellow ochre (from schists and iron ore deposits), processed natural ochres, yellow iron...
Characterization of Japanese color sticks by energy dispersive X-ray fluorescen...
Manso, M.; Valadas, S.; Pessanha, S.; Guilherme, A.; Queralt, I.; Candeias, A.E.; Carvalho, M.L.This work comprises the use of energy dispersive X-ray fluorescence (EDXRF), X-ray diffraction (XRD) and Fourier transformed infrared (FTIR) techniques for the study of the composition of twentieth century traditional Japanese color sticks. By using the combination of analytical techniques it was possible to obtain information on inorganic and organic pigments, binders and fillers present in the sticks. The col...
Yellow and red ochre pigments from southern Portugal: Elemental composition and...
Gil, M.; Carvalho, M.L.; Seruya, A.; Candeias, A.E.; Mirao, J.; Quiralt, I.Three different yellow and red ochre pigments geological sources from Alentejo—Terras rossas, schist units and weathered iron ore deposits—were studied by elemental and phase analysis complemented with Munsell and CIELAB colour parameters. Central aims were to underline the mineralogical and chemical distinctiveness of natural pigment sources and establish a connection between local geology and use of specific c...
Microscopic characterisation of old mortars from the Santa Maria Church in Évora
Adriano, P.; Santos Silva, A.; Veiga, R.; Mirão, J.; Candeias, A.E.Evora Cathedral (one of the most emblematic monuments of Evora—Portugal) has suffered several conservation and restoration interventions through the ages, without, however, any type of previous knowledge about mortars and materials used. This work was carried out in order to identify the mortar's composition in different locations, which were attributed to different construction or conservation periods. The cha...
Characterisation of roman mortars from the historical town of Mertola
Silva, A.S.; Ricardo, J.; Salta, M.; Adriano, P.; Mirao, J.; Candeias, A.E.Ancient mortars from two Mertola’s important Roman monuments, the River Tower and the Cryptoportic, were characterized by optical microscopy, scanning electron microscopy, X-ray diffraction, thermogravimetric and chemical analyses. The results show that all mortars are calcitic aerial lime mortars and that the aggregates are composed of quartzitic river sand and crushed schist. Samples from the River Tower and ...
Geoquímica de sedimentos de linha de água da antiga mina da Tinoca. Análise est...
Nogueira, P.; Morais, C.; Rosado, L.; Lopes, M.E.; Mirão, J.; Candeias, A.E.A geochemical study based on sequential extraction of four elements (Cu, Zn, Fe, and Pb) was conducted in the stream sediments of the ancient Cu mine of Tinoca (Alto Alentejo – Portugal). The statistical and spatial analysis allowed the inference of the affinities between the chemical elements. The relations can be expressed as stronger between the Cu, the Pb, the Fe and the Zn respectively. The distance to the...
Extracção sequencial em sedimentos e resíduos da antiga mina da Tinoca: geoquím...
Morais, C.; Mirão, J.; Rosado, L.; Pinto, A.P.; Lopes, M.E.; Nogueira, P.; Candeias, A.E.Mine wastes and sediments from the ancient copper mine of Tinoca (Alto Alentejo – Portugal) were submitted to a sequential extraction with the objective to establish distribution patterns for copper (Cu), iron (Fe), zinc (Zn) and lead (Pb) in different specific phases: amorphous oxides; rystalline oxides; sulphides and silicates. The results of the sequential extraction showed that Cu and Fe were predominantly ...
Influence of fly ash and metakaolin in the inhibition of delayed ettringite for...
Soares, D.; Candeias, A.E.; Divet, L.; Santos Silva, A.In the last few years it has been observed in Portugal, as well as in other countries worldwide, several cases of concrete structures affected by internal expansive reactions, particularly by delayed ettringite formation (DEF). This pathology, which is macroscopically characterized by the occurrence of cracks and fissures in concrete due to the expansion of the reaction product, is very difficult to deal with, ...
Os líquenes – sua aplicação em estudos de biomonitorização e etnobotânica
Gouveia, T.; Rosado, L.; Candeias, A.E.; Costa, C.; Santos SIlva, C.Foi efectuado um estudo de monitorização da poluição atmosférica, na região de Évora, utilizando líquenes como bioindicadores. Nos três locais de amostragem, dois próximos de redes viárias com tráfego médio a intenso e outro situado numa área de montado, procedeu-se à inventariação, recolha e mapeamento das espécies liquénicas presentes sobre oliveiras. Das espécies identificadas, seleccionaram-se: Flavoparmeli...