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

The environmental factors impact on the conservation of an historic marine quay—a baseline study

Changes effected by environmental factors on the biological colonization of an historic marine limestone quay were considered, as a baseline study for the monitoring and test plan definition. Environmental factors play a fundamental role in the deterioration of stone monuments, particularly those located in a marine environment. This eighteenth century quay, situated at the Royal Square of the Portuguese capital, is subject to tidal movement, marine aerosol, high levels of pollution and vibration and is partly submerged in polluted water. Part of the quay was dismantled in 1997 and returned to the river water in 2008; since then, progressive (re)colonization by biological organisms has occurred. By means of periodic photographic registry, from 2010 to 2014, the main alterations and deposits on its surfaces were registered. The present paper discusses and presents a vulnerability assessment and monitoring plan for monuments in a marine environment with a view to establishing a preventive conservation plan.info:eu-repo/semantics/publishedVersio

The environmental factors impact on the conservation of an historic marine quay-a baseline study

Changes effected by environmental factors on the biological colonization of an historic marine limestone quay were considered, as a baseline study for the monitoring and test plan definition. Environmental factors play a fundamental role in the deterioration of stone monuments, particularly those located in a marine environment. This eighteenth century quay, situated at the Royal Square of the Portuguese capital, is subject to tidal movement, marine aerosol, high levels of pollution and vibration and is partly submerged in polluted water. Part of the quay was dismantled in 1997 and returned to the river water in 2008; since then, progressive (re)colonization by biological organisms has occurred. By means of periodic photographic registry, from2010 to 2014, themain alterations and deposits on its surfaces were registered. The present paper discusses and presents a vulnerability assessment and monitoring plan for monuments in a marine environment with a view to establishing a preventive conservation plan

Estudo das formulações proteicas das camadas de preparação de um conjunto de retábulos Portugueses dos séculos XV-XVI por micro-FTIR – uma abordagem quimiométrica

The binding media used for the ground layer production of Portuguese paintings from the 15th-16th centuries was studied by μ-FTIR, following a chemometric approach. Principal Component Analysis was restricted to the ester-amide absorption region (1745-1604 cm-1), which proved to be the best spectral window for characterizing ground layer formulations (namely, the binder-gypsum ratio of ground layers). The PCA analysis allowed to discriminate between artists according to some specificities used in the paintings production, as the use of an oil-based layer over the ground layer, probably as a polish impermeabilization layer. This paper, it will be presented the approach and main findings for the paintings studied mostly integrated in Portuguese workshops of Lisboa and Coimbra.