Exploring the potential of cuttlebone waste to produce building lime

The goal of this study is to find a practicable way to recycle cuttlebone waste in the production of lime. It was studied the behavior of calcium oxide obtained from the calcination of this waste at 900, 1000 and 1100 ºC and, after wet slaking, the produced lime was characterized. All the results were compared to calcium oxide or to hydrated lime obtained from commercial limestone. According to the slaking results, the waste and the limestone calcined at 1000 ºC achieved the R4 (around 13 min to reach 60 ºC) and R5 (60 ºC in 25 s) reactiv­ity class, respectively. Changing the calcination temperature to 900 or 1100 ºC did not promote an increase in the reactivity of the calcined waste. Although less reactive than the calcined limestone, the calcined cuttlebone can be transformed without significant constraint into building lime, since this construction material fulfills the relevant physic-chemical standard specifications.The authors thank VAC Minerais, S.A. (Rio Maior, Portugal) for supplying the commercial limestone, the support of Quadro de Referência Estratégica Nacional (QREN) and R&D units: Techn&Art (UID/05488/2018) and Geobiotec (UID/GEO/04035/2019). They also thank Prof. Dr. Francisco Franco Duro, from the University of Malaga (Spain), for the translations to Spanish language.info:eu-repo/semantics/publishedVersio

Estudo das argamassas do Cais das Colunas (Séc. XVIII), Lisboa, Portugal

O Cais das Colunas é o único cais monumental construído, em Lisboa, no âmbito do projeto de reconstrução da cidade depois do terramoto de 1755. O cais foi parcialmente desmontado em 1997 e reconstruído em 2008. Durante os trabalhos de reposição foram recolhidas amostras de argamassas originais, datáveis das décadas de 1770 a 1790, do núcleo do embarcadouro, tendo em vista o seu estudo e caracterização. A metodologia analítica envolveu a realização de ensaios químicos, mineralógicos e físicos, nomeadamente de espetrometria de fluorescência de raios X (FRX), difração de raios X (DRX) e absorção capilar por contacto (ACC). Os resultados obtidos foram comparados com os de argamassas de período cronológico e localização congéneres, confirmando-se a sua consonância, nomeadamente do uso, para a formulação das argamassas, de areias locais e da cal aérea como ligante.info:eu-repo/semantics/publishedVersio

Selection of processing parameters in laser microwelding. Part 1: Continuous wave (CW) mode

A phenomenological model which specifies the penetration depth and width of the fusion zone in laser microjoining can be a very useful tool in achieving the required welding parameters for a desired application. In this study the power factor model, previously established and validated in macrowelding, has been tested in fibre laser microwelding, enabling achievement of a particular weld independently of a laser system. Differ-ent weld profiles in aluminium and stainless steel were correlated with various combinations of parameters for a wide range of beam diameters. It has been shown that the same penetration depth can be achieved with different weld profiles. A similar trend, as previously found in macrow-elding, has been confirmed in microwelding. It was demonstrated that the depth of penetration can be kept constant independently of the laser sys-tem until certain limit of beam size

X-ray fluorescence (conventional and 3D) and scanning electron microscopy for the investigation of Portuguese polychrome glazed ceramics: Advances in the knowledge of the manufacturing techniques

This work shows the first analytical results obtained by X-Ray Fluorescence (XRF) (conventional and 3D) and Scanning Electron Microscopy with Energy Dispersive System (SEM-EDS) on original Portuguese ceramic pieces produced between the 16th and 18th centuries in Coimbra and Lisbon. Experts distinguished these productions based only on the color, texture and brightness, which originates mislabeling in some cases. Thanks to lateral and spatial resolution in the micrometer regime, the results obtained with μ-XRF were essential in determining the glaze and pigment thicknesses by monitoring the profile of the most abundant element in each “layer”. Furthermore, the dissemination of these elements throughout the glaze is different depending on the glaze composition, firing temperature and on the pigment itself. Hence, the crucial point of this investigation was to analyze and understand the interfaces color/glaze and glaze/ceramic support. Together with the XRF results, images captured by SEM and the corresponding semi-quantitative EDS data revealed different manufacturing processes used by the two production centers. Different capture modes were suitable to distinguish different crystals from the minerals that confer the color of the pigments used and to enhance the fact that some of them are very well spread through the glassy matrix, sustaining the theory of an evolved and careful procedure in the manufacturing process of the glaze

Technological and compositional study of the gold leaf from Portuguese Baroque altarpieces from the northwest region

No abstract available

Propiedades cerámicas de las arcillas de la cantera de Asseiceira (Tomar, Portugal)

The clay mined at the Asseiceira quarry near the city of Tomar, Portugal, has traditionally been used to manufacture hollow brick. However, since an assessment has shown the ceramic properties of the strata to vary, the quarry could potentially produce clay blends of different qualities to form raw materials appropriate for items demanded by different market segments, such as high quality facing brick and roof or floor tiles. The composition and texture of the various clay materials identified in the Asseiceira quarry were characterized using analytical techniques such as X-ray diffraction (XRD), X-ray fluorescence (XRF), Atterberg limits and grain size analysis The phases resulting from the thermal transformations taking place during drying and firing were identified with thermogravimetric (TG), differential scanning calorimetric (DSC), and thermodilatometric (TD) techniques. Finally, certain relevant ceramic properties such as linear shrinkage, bending strength and water absorption at 875 °C, 950 °C, 1025 °C and 1100 °C were determined on the raw material after extrusion.Las arcillas de la cantera de Asseiceira, localizadas cerca de la ciudad de Tomar (Portugal), han sido utilizadas tradicional mente en la fabricación de ladrillos. Sin embargo, el estudio de muestras procedentes de distintas capas de la cantera, ha mostrado que sus propiedades cerámicas son diferentes, lo que hace posible la formulación con diferentes grados de calidad apropiados para aprovisionar a distintos sectores del mercado de materiales cerámicos para la construcción. En este trabajo se exponen los resultados de la caracterización de los materiales arcillosos identificados en la cantera de Asseiceira mediante difracción de rayos-X (DRX), fluorescencia de rayos-X (FRX), plasticidad de Atterberg y análisis granulométrico. Las transformaciones térmicas que tienen lugar durante las etapas de secado y cocción han sido identificadas mediante análisis termogravimétrico (TG), calorimetría de barrido diferencial análisis termodilatométrico (TD). En último lugar, se han determinado algunas propiedades cerámicas relevantes, tales como contracción lineal, resistencia mecánica a la flexión y absorción de agua a 875 °C, 950 °C, 1.025 °C y 1.100 °C, después de someter las materias primas a conformación plástica

Estudo tecnol gico e composicional da folha de ouro de ret bulos barrocos bases para uma metodologia de investiga o

The gold leaf from one of the most important art works of the Portuguese Baroque period, the main altarpiece of the Church of Jesus in Aveiro, currently part of the city Museum and former Convent of Jesus, was studied. Qualitative analysis of the samples cross-section was performed by optical microscopy. Three different layers – ground layer, bole and gold – were identified, a result consistent with a traditional gilding. The use of scanning electron microscopy with energy dispersive spectroscopy (SEM-EDS) showed the use of a ternary Au-Ag-Cu alloy, with approximately 22 carats. Through inductively coupled plasma mass spectrometry (ICP-MS) it was possible to identify trace elements such as Cr, Pt, Pd and Sn in the gold, and Pb and Hg in the bole layer. The use of synchrotron radiation micro X-ray fluorescence (SR-µXRF) confirmed the presence of Sn and allowed to establish a profile of the main elements in the samples