DSpace Community:
http://hdl.handle.net/10174/14473
2024-03-28T12:46:28ZCellulose ethers and nanoconsolidants: preliminary observations on the suitability of the use of cellulose derivatives in the synthesis of nanolime particles
http://hdl.handle.net/10174/36519
Title: Cellulose ethers and nanoconsolidants: preliminary observations on the suitability of the use of cellulose derivatives in the synthesis of nanolime particles
Authors: Girginova, Penka; Galacho, Cristina
Abstract: This communication reports the preliminary
results of our ongoing research on the effect of addition of cellulose-derivatives, such as cellulose ethers, in the synthesis of calcium hydroxide (Ca(OH)2) micro-sized particles. Particles of Ca(OH)2 were synthesised without and with addition of different amounts hydroxypropyl methylcellulose (HPMC). The
obtained particles were characterized with X-ray diffraction (XRD), scanning electron microscopy (SEM) and Fourier-transform infrared spectroscopy (FTIR). Our preliminary results anticipate that syntheses with addition of HPMC originated the formation of smaller and more uniform in shape and size Ca(OH)2 particles in comparison with the Ca(OH)2 particles synthesized without addition of HPMC. This study contributes to
the urgent need of innovative non-toxic sustainable materials, compatible with the original artworks, with long-term efficiency and easy for application.2023-10-20T23:00:00ZAn Archaeometric Analysis of Black-Appearing Iron Age Glass Beads from Vinha das Caliças 4 (Portugal)
http://hdl.handle.net/10174/36437
Title: An Archaeometric Analysis of Black-Appearing Iron Age Glass Beads from Vinha das Caliças 4 (Portugal)
Authors: Lončarić, Valentina; Arruda, Ana Margarida; Barrulas, Pedro; Costa, Mafalda
Abstract: Phoenician colonisation of the Iberian Peninsula in the 1st millennium BCE introduced many novel and luxurious goods to the local populations of the Western Mediterranean. Among them, black-appearing glass beads are characteristic of indigenous female burials in Southern Portugal during the 6th century BCE. This study presents the results of the first comprehensive archaeometric investigation of black-appearing glass from Vinha das Caliças 4 (Portugal), and of black-appearing glass from the Iberian Peninsula in general. A multi-analytical approach employing Stereomicroscopic observation of manufacture and use traces, VP-SEM-EDS, μ-XRD, and LA-ICP-MS was used to cover a wide range of questions regarding technology and provenance. All analysed samples are natron glass. All samples of black and white beads are characterized by high Zr and low Sr values typically ascribed to the use of Egyptian sands. A comparison of the results of previous studies from the same site clearly demonstrates at least two geochemical provenances for Phoenician-traded glass beads, located in the Levantine region and Egypt, respectively. Furthermore, different colours of glass in individual polychrome beads exhibit similar trace element patterns, which might suggest these beads could have been produced close to glassmaking sites/regions.2024-01-01T00:00:00ZMortars and Renders: The Case of the Roman Villa Horta da Torre Fronteira, Portugal
http://hdl.handle.net/10174/36379
Title: Mortars and Renders: The Case of the Roman Villa Horta da Torre Fronteira, Portugal
Authors: Ditta, A; Carneiro, André; Galacho, Cristina; Moita, Patrícia
Editors: Veiga, João Pedro
Abstract: The archaeological site of villa Horta da Torre in Portugal reveals distinctive architectural features within the context of Roman villae in Hispania. Notably, the triclinium was designed with an artificial cascade originating from a double apse wall, and the walls were adorned with mosaic tessellae panels and marble skirting. During the Roman era, the surrounding area belonged to the former province of Lusitania, with Augusta Emerita serving as its capital. This study examines 11 mortar samples from various contexts and functions, such as masonry, preparatory, render, and opus signinum mortars. A set of complementary analytical techniques was employed to determine
the textural and mineralogical compositions of the mortars. The aim was to gain insights into the production techniques and the selection of raw materials within the geological context of this rural construction. It was observed that the processing of raw materials and production techniques did not always adhere to the rules of Vitruvius. A comparison with other villas revealed comparatively less meticulous attention to sand selection and precise layering for mural painting. Nevertheless,
it was noted that in preparatory layers for the supranucleus and nucleus tesserae, ceramic pieces were intentionally added to improve the mortar. The binder used was calcitic lime, likely obtained
from locally sourced limestone. The nature of aggregates is diversified but consistent with the local geological provenance within a radius of less than 3 km, in accordance with two sand exploration sites. This research aligns with the United Nations’ 2030 Agenda for Sustainable Development, contributing specifically to SDG 11 and Target 11.4, which “aims to strengthen efforts to protect and
safeguard the world’s cultural and natural heritage”2024-03-14T00:00:00ZA Casa de Fresco do Paço de São Miguel
http://hdl.handle.net/10174/36367
Title: A Casa de Fresco do Paço de São Miguel
Authors: Galacho, Cristina; Moita, Patrícia; Cardoso, Ana
Abstract: Caraterização de argamassas, embrechados, eflorescências salinas e pigmentos pp 60-75
No decorrer do programa de intervenção na Casa de <fresco foi realizada pela equipa de cientistas do Laboratório HERCULES a caracterização dos elementos estruturais, decorativos e estudos das comunidades microbiológicas presentes nesta “arquitetura de água” localizada no jardim do Paço de São Miguel. Esta abordagem especializada permitiu, por um lado, conhecer em detalhe os materiais que constituem este documento e, por outro, identificar os agentes que contribuem para a sua deterioração. A leitura e compreensão destes resultados avalizados são determinantes para a implementação de uma estratégia eficaz no âmbito da salvaguarda deste conjunto patrimonial que conserva um importante valor histórico, artístico e cultural2023-01-01T00:00:00Z