A carregar...
Projeto de investigação
Sem título
Financiador
Autores
Publicações
In full swing
Publication . Tissot, I.; Ottone Alves, B.; Silva, T.; Nogueira, F.; Manso, M.; LIBPhys-UNL; DF – Departamento de Física; UNIDEMI - Unidade de Investigação e Desenvolvimento em Engenharia Mecânica e Industrial; DEMI - Departamento de Engenharia Mecânica e Industrial; VICARTE - Vidro e Cerâmica para as Artes; DCR - Departamento de Conservação e Restauro; Elsevier
The condition assessment of Industrial Heritage machinery in operation is an open research subject of utmost importance for defining conservation and maintenance plans. The present work approaches this issue by proposing the study of Industrial Heritage machinery that includes the assessment of substrates, coatings, lubricants and operating mechanisms by applying analytical techniques currently used for heritage studies together with techniques employed in condition monitoring of modern machinery. An early 20th century steam engine from the Vale de Milhaços Gunpowder Factory (Portugal), in operation for demonstration purposes, was selected as a case study. The engine metallic alloys and coatings were studied by XRF and Raman spectroscopies, and the main properties of lubricants studied according to EN ISO and ASTM standard tests. Metallic particles present in the oil due to wear were assessed by XRF. The mechanisms were examined by gamma radiography, magnetoscopy, thermography and vibrational analysis. Data showed the use of distinct alloys according to the engine components' function similar to those reported for the same period. Green copper phthalocyanine and toluidine red identified as coatings’ pigments are typical from the late 20th century and thus ascribed to a previous repair. The properties of the fresh and used lubricants are slightly different but without evidence of a significant alteration that could endanger the machine's functioning. However, the presence of metallic particles in the oil suggested the existence of wear phenomena. The engine's operating speed (51 rpm) and the vapour temperature (≈154 °C) attained inside the cylinder were indirectly determined. The presence of cracks on the engine structure was assessed, and possible faults that can imperil the engine functioning were analysed. The vibrational analysis of equipment in operation revealed a lack of lubrication and wear on the feed pump journal bearings.
Characterization of Tableware from Fábrica de Loiça de Sacavém—Linking Analytical and Documental Research
Publication . Coutinho, Mathilda L.; Veiga, João Pedro; Ruivo, Andreia; Pereira da Silva, Teresa; Bottura-Scardina, Silvia; Lima, Maria Margarida R. A.; Pereira, Carlos; Dias, Ana Carvalho; Dias, Luís; Vandenabeele, Peter; Roseiro, José Carlos; VICARTE - Vidro e Cerâmica para as Artes; DCR - Departamento de Conservação e Restauro; CENIMAT-i3N - Centro de Investigação de Materiais (Lab. Associado I3N); DCM - Departamento de Ciência dos Materiais; MDPI - Multidisciplinary Digital Publishing Institute
Fábrica de Loiça de Sacavém (ca. 1858–1994) was among the first to produce white earthenware in Portugal, becoming one of the country’s leading ceramic manufacturers during the late 19th to early 20th centuries. Research on white earthenware has accompanied the growing interest in post-industrial archaeology but is still poorly explored compared to more ancient ceramic productions. This study focused on the ceramic body, glazes, and colourants of tableware produced by Fábrica de Loiça de Sacavém during the first 50 years of its activity (1859–1910). A multi-analytical approach was selected to investigate the chemical and mineralogical composition of the ceramic body, glaze, and pigments using optical microscopy, variable-pressure scanning electron microscope energy-dispersive X-ray spectroscopy (VP-SEM-EDS), μ-Raman spectroscopy, μ-X-ray Diffraction (μ-XRD), and reflectance spectroscopy (hyperspectral image analysis). The studied tableware was produced with a Ca-poor siliceous–aluminous white earthenware ceramic body covered with transparent alkali lead or lead borosilicate glaze, and most colourants were complex Cr-based pigments. These results are in agreement with the little documental evidence from this period found in the manufacturer’s archives.
The colour palette of 16th-18th century azulejos
Publication . Bandiera, Mario; Veronesi, Umberto; Manso, Marta; Ruivo, Andreia; Vilarigues, Márcia; Esteves, Lurdes; Pais, Alexandre; Coentro, Susana; VICARTE - Vidro e Cerâmica para as Artes; LIBPhys-UNL; DCR - Departamento de Conservação e Restauro; Elsevier
This work provides an overview of the pigments used by Portuguese azulejo painters through the study of 34 glazed tiles belonging to the National Azulejo Museum in Lisbon, Portugal. The tiles are dated from the late 16th century to the early 19th century, with most samples attributed to the 17th and 18th centuries. Building on a previous study where the chemical composition of the 17th-century colour palette was characterised [1], we used a non-invasive methodology to further identify compositional differences among groups of colours spanning a wider timeframe. Blue, white, yellow, orange, purple, green and brown decorations were analysed by EDXRF to obtain qualitative and (in some samples) quantitative information on their chemical composition. µ-Raman spectroscopy was used to identify the main colouring agents. Finally, colorimetric measurements of the different hues of each colour were performed to address the relation between colour and chemical composition. Our results show that greens could be obtained through a copper-based pigment or by mixing lead-antimonate with cobalt-blue pigment. Although cobalt is the colouring agent of all blue decorations, compositional differences suggest the use of different types of raw materials or the addition of specific reagents to modify the hue. On the other hand, yellow hues ranging from lemon yellow to orange were manufactured by adding zinc, tin, or iron oxide to a lead antimonate base. Finally, a manganese ore was used to make the purple pigment. Overall, we noted that while the basic pigments remained the same, the colour palette was progressively widened during the 18th century. This was done by using more pure pigments (i.e., with less iron), by changing the ratio in pigment mixtures (i.e., blue and yellow), or by overlapping colour layers for artistic effects. Finally, the results of the chemical and colorimetric analyses are always influenced by the concentration of the pigment in the glaze, its thickness and the overlapping of pigments used by azulejo painters to expand the shades available for the final artistic composition.
Unidades organizacionais
Descrição
Palavras-chave
Contribuidores
Financiadores
Entidade financiadora
Fundação para a Ciência e a Tecnologia
Programa de financiamento
Concurso de avaliação no âmbito do Programa Plurianual de Financiamento de Unidades de I&D (2017/2018) - Financiamento Base
Número da atribuição
UIDB/00729/2020