Percorrer por autor "Bottaini, Carlo"
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- Art casting in Portuguese 19th century industrial foundries: a multi-analytical study of an emblematic copper-based alloy monumentPublication . General-Toro, Pablo; Bordalo, Rui; Moreira, Patrícia Raquel; Vieira, Eduarda; Brunetti, Antonio; Iannaccone, Roberta; Bottaini, CarloThe outdoor sculpture of the first Portuguese king, D. Afonso Henriques (~1109 – 1185 AD), placed in Guimarães (North Portugal) is one of the most emblematic national sculptures. Created in 1887 by António Soares dos Reis, it possesses a remarkable symbolic value in the presumed birthplace of the king. In addition to the artistic and heritage importance of the monument, it is one of the few sculptures cast by a Portuguese industrial foundry in the 19th-century. This study obtained data on the sculpture's elemental composition and corrosion products, gathering important historical and technical information. For this purpose, a multi-analytical approach consisting of X-ray fluorescence (XRF), X-ray diffraction (XRD), optical microscopy (OM) and scanning electron microscopy (SEM-EDS) was carried out to characterise the bulk metal and corrosion layers. The data revealed a ternary alloy of Cu, Sn, Zn with Pb, Fe, As, Bi and Mn as minor elements. The alloy matches that of other sculptures cast in that period. In terms of corrosion, it is characterised by the presence of oxides. These results represent the first step for applying an appropriate conservation strategy for bronze sculptures with similar characteristics.
- Art casting in portuguese 19th century industrial foundries: a multi-analytical study of an emblematic copper-based alloy monumentPublication . General-Toro, Pablo; Bordalo, Rui; Moreira, Patrícia Raquel; Vieira, Eduarda; Brunetti, Antonio; Iannaccone, Roberta; Bottaini, CarloThe outdoor sculpture of the first Portuguese king, D. Afonso Henriques (c. 1109–1185 AD), placed in Guimarães (North Portugal), is one of the most emblematic national sculptures. Created in 1887 by António Soares dos Reis, it possesses a remarkable symbolic value in the presumed birthplace of the king. In addition to the artistic and heritage importance of the monument, it is one of the few sculptures cast by a Portuguese industrial foundry in the 19th century. This study obtained data on the sculpture’s elemental composition and corrosion products, gathering important historical and technical information. For this purpose, a multi-analytical approach consisting of X-ray fluorescence (XRF), X-ray diffraction (XRD), optical microscopy (OM) and scanning electron microscopy (SEM-EDS) was carried out to characterise the bulk metal and corrosion layers. The data revealed a ternary alloy of Cu, Sn and Zn, with Pb, Fe, As, Bi and Mn as minor elements. The alloy matches that of other sculptures cast in that period. In terms of corrosion, it is characterised by the presence of oxides. These results represent the first step for applying an appropriate conservation strategy for bronze sculptures with similar characteristics.
- A framework design for information management in heritage science laboratoriesPublication . Bordalo, Rui; Bottaini, Carlo; Candeias, AntónioThe dataflow in any scientific research laboratory is continuous and considerable even in analytical niches such as heritage science laboratories. This article discusses advantages of using a Laboratory Information Management System (LIMS) for organising and systematising research in an interdisciplinary analytical laboratory. LIMS solutions are proven to be effective in managing laboratories, organising their daily management tasks, improving work conditions and increasing productivity, managing equipment and resources, and managing and safeguarding scientific data. LIMS software is commercially available since the 1990s with over a hundred software packages intended either for general or specific purposes. However, the ones currently available do not fulfil all the requirements for heritage science or are over-the-top, complex, one-fits-all standard solutions. The system here proposed was developed for a heritage science laboratory, considering its unique requirements, having as a case study the HERCULES Lab, from the University of Évora (Portugal). This article documents our approach based on the analysis of the unique requirements for the lab resulting in a proposal of a custom user-centred web-based system. For this, we discuss in detail the workflow, and the required system architecture. We conclude that although it is a small niche market for major manufacturers to dwell on, a custom LIMS is of the utmost importance for the current management of heritage science laboratories across the globe.
- Islamic copper-based metal artefacts from the Garb al-Andalus. A multidisciplinary approach on the Alcacova of Martulah (Mertola, South of Portugal)Publication . Bottaini, Carlo; Martínez, Susana Gómez; Bordalo, Rui; Beltrame, Massimo; Mirão, José; Rafael, Lígia; Schiavon, NickA multidisciplinary approach has been applied to investigate the production technology of a collection of copper-based artefacts found during archaeological excavation campaigns carried out in the Almohad neighbourhood of Mārtulah, the Islamic name of modern Mértola (South of Portugal). In stark contrast to other Islamic materials found in the same site such as common and finely decorated pottery, glass, and bone artefacts, metal objects have received less attention despite the high number of artefacts recovered. This study focuses on the chemical characterisation of 171 copper-based artefacts dating back to the 12th and the first half of the thirteenth centuries. The artefacts are daily use objects and consist of personal ornaments (earrings, rings, and casket ornaments), tools (spindles, spatulas, and oil lamp sticks) and artefacts with unknown functions. The analytical results by X-ray fluorescence Spectroscopy (XRF) provided information not only about technological issues but infer as well on the socio-economic implications of metal consumption in Islamic Mértola. Results revealed that metals were produced using a variety of Cu-based alloys, namely unalloyed copper, brasses (Cu + Zn), bronzes (Cu + Sn), and red brasses (Cu + Sn + Zn), with a variable concentration of Pb, without any apparent consistency, as a likely result of recurrent recycling and mixing scrap metals practices or use of mineral raw materials available locally.
- Modelling an XRF method for determining gilding thickness in silver cultural heritage objects without sample collection: case studies on 16th century Portuguese silverwarePublication . Lopes Cordeiro, Catarina; Bottaini, Carlo; Bordalo, Rui; Sousa, Gonçalo Vasconcelos e; Pessanha, SofiaIn situ X-ray fluorescence is a non-invasive technique that is widely used in historical objects, namely in pieces of gilded silver, to determine the composition of the alloy and gilding. In the case of gilded silver, fire gilding was a mercury-based historical technique that is no longer practiced. Moreover, with traditional XRF analysis is possible to determine the thickness of the gilding by using given intensity ratios of the characteristic lines of silver. However, this requires the analysis of the substrate, for the calculation of the intensity ratio without gilding, which is not always accessible. This study presents and validates a methodology for the calculation of the thickness of fire gilding silver pieces using XRF analysis with a commercial spectrometer and without the need to analyse the isolated substrate. Six silver alloy mock-up samples were produced following historical techniques and generic intensity ratio for K? and K? lines of silver in the alloy was calculated (6.35 ± 0.05), to be used in any alloy with a silver composition over 75 %. Since attenuation of the silver's characteristic lines depends on the gilding composition, different Hg concentrations (5 %–20 %) were tested. The results obtained with this approach for the mock-ups was compared with SEM-EDS measurements for gauging uncertainty and the methodology was then applied to three pieces of 16th century Portuguese silverware. This adaptation of previously established principles, proved to be effective to calculate the thickness of fire gilding on silver and was validated to be applied, in situ, in real museum artworks without the need for sample collection.
- Ourivesaria portuguesa do século XVI: estudo multidisciplinar da prataria religiosaPublication . Cordeiro, Catarina Lopes; Bottaini, Carlo; Bordalo, Rui; Sousa, Gonçalo de Vasconcelos eO século XVI foi um período de grande desenvolvimento da ourivesaria portuguesa. No entanto, os estudos realizados até ao momento sobre este rico espólio artístico têm-se focado principalmente nos aspetos iconográficos, estilísticos e histórico-artísticos sendo que ainda pouco se conhece quanto aos aspetos materiais e técnicos. De modo a ajudar a colmatar esta lacuna, encontra-se em desenvolvimento um projeto que, através de métodos de exame e análise, pretende obter informações, até hoje desconhecidas, sobre as características tecnológicas de um grupo selecionado de objetos em prata, que inclui cálices, patenas, custódias e cruzes.
- Supercritical carbon dioxide: cleaning and stabilization tests for copper alloys and iron keys from a scientific collection of the Centro Hospitalar Conde de Ferreira (Porto, Portugal)Publication . Figueiredo, Catarina; Camarneiro, Nuno; Bottaini, Carlo; Bordalo, Rui; Silva, Inês; Duarte, Marta; Vieira, EduardaAn increasing number of eco-friendly nanotechnologies for the conservation of cultural heritage materials are becoming available. These include supercritical carbon dioxide (scCO2), which has proven to be a viable green, non-flammable, and ecological method. While previously tested and now widely used in the pharmaceutical and food industries, scCO2 has recently been applied in the conservation of cultural heritage objects, and specifically for their cleaning, consolidation, and stabilization. Experience has shown that scCO2 is a promising alternative to conventional toxic organic solvents for the removal of organic materials, such as oils, grease deposits, and active corrosion products. In this study, we tested and applied scCO2 as a cleaning and stabilization agent on two coils of copper and silk textile wires used in the electrical induction mechanism of a faradic machine and on an iron key from a set of handcuffs. Both objects come from a set of psychiatric instruments and equipment dating from the 19th to the mid-20th century that now form part of the scientific collection of the Centro Hospitalar Conde de Ferreira, which belongs to Museu da Misericórdia do Porto, Portugal. Portable X-ray fluorescence was carried out before and after scCO2 treatment to determine the elemental composition of the metal alloys and the effectiveness of the cleaning process. Before the objects were treated, scCO2 was tested on eight samples of similar material and degradation pathologies. Comparative experiments were performed with and without the addition of a co-solvent to scCO2. The co-solvents included ethanol, hydrogen peroxide, ethylenediaminetetraacetic acid (EDTA), and sodium hexametaphosphate. Different temperatures, reaction times, and pressures were evaluated. Cleaning efficiency was assessed by the visual examination of dirt removal, material stabilization, oxidation stain removal, fiber mechanical strength, and dye loss. The results revealed that scCO2 without the addition of a co-solvent did not have a significant impact on the samples compared to when it was applied with ethanol or EDTA, which as co-solvents improved cleaning and stabilized the corrosion products. The respective formulations proved to be suitable alternatives for the treatment of metal artifacts as well as objects composed of different materials.