Traditional dyeing – an educational approach

This paper describes a mini-project developed with 10th grade Portuguese students where, by using an experimental activity involving the use of natural dyes to colour wool, students acquired a better understanding of the concepts and relationship between the colour, the electromagnetic spectrum, and chemical bonding. As demonstrated by the results of a laboratory activity interest survey, the interdisciplinary nature of the mini-project contributed to raise student awareness to the existing relationship between science, culture and daily life, promoting their overall interest in scientific topics

Coumarin amine-reactive dye C392STP: an efficient building block to synthesize single-labeled oligonucleotides with application as FISH probes

The demand of new reactive fluorophores with improved photophysical characteristics for labeling oligonucleotide probes is growing. Sodium (E/Z)-4-(4-(2-(6,7-dimethoxycoumarin-3-yl)vinyl)-benzoyl)- 2,3,5,6-tetrafluoro-benzenesulfonate (C392STP) is an amine-reactive fluorescent dye that has recently shown interesting photophysical properties. In this work, we investigate the possibility of: i) synthesizing it cheaply and easily; ii) using this reactive dye to synthesize single-labeled fluorescent oligonucleotides; and iii) applying the resulting fluorescently labeled oligonucleotides as fluorescence in situ hybridization (FISH) probes. According to the results obtained in this study, C392STP: i) can be synthesized through a low cost and simple pathway; ii) is an efficient building block for mono-labeling of oligomers with an efficiency as high as that of an amine-reactive Alexa Fluor® 488 dye supplied in a commercial oligonucleotide labeling kit. Furthermore, the RNA-FISH assays revealed that C392-mono-labeled probes containing standard carbon linkers (C6) exhibited effective performance as RNA-FISH probes. These findings evidenced the applicability of C392STP in labeling of biomolecules and bioimaging. The results invite the researchers to continue exploring other uses of this reactive dye for exploiting its potential in biological applications

Tracking old and new colours: Material study of 16th century mural paintings from Évora Cathedral (Southern Portugal)

This article describes the results of a multi-analytical research carried out on the mural paintingsfromEvora Cathedral, one of the oldest and most promi-nent monuments ofEvora city. The paintings were a late16th Century addition to the cathedral’s northern tran-sept chapel and are attributed to the painter JosedeEscovar, whose painting workshop was remarkably activein the so-called golden age of mural pai ntings in south-ern Portugal. The aim of the study was to reconstruct thepaintings’ life story through a material s science perspec-tive by discerning the material characteristics of the orig-inal and overpaint campaigns. The analytical setupcomprised technical photography (TP) in the visible andUV light, Vis-Spectrophotometry, optical microsc opy(OM) complemented with scanning electron microscopywith energy dispersive X-ray spectrometry (SEM-EDS),micro Fourier transform infrared spectrometry (mFT-IR)and pyrolysis–gas chromatography (Py-GC/MS) analysesof the collected samples. Results show that the originalpaint layers were executed with a combination of frescoand secco techniques, using a very simple chromatic pal-ette composed of earth pigments, mercury sulphide, cal-cium carbonate and green copper based pigments. Thepaintings were heavily retouched and overpainted usingearth pigments, smalt, Prussian blue, zinc white and leadwhite. Furthermo re, the analyses of the cross-sectionstaken from the stuccoed frames revealed a first decora-tive campaign made with gold and silver allo

Stucco Marble in the Portuguese Architecture: Multi-analytical Characterisation

The presence of stucco marble in the Portuguese architecture is not surveyed and studies addressing the materials used to produce it are almost inexistent. In this paper, the results of the multi-analytical characterisation using XRD, SEM-EDS, Py-GC/MS and the determination of capillary water absorption and dynamic modulus of elasticity of 15 samples belonging to seven case studies are presented and discussed. XRD showed that gypsum is the main constituent, but anhydrite is also present in most samples. These results were consistent with the observations by SEM-EDS, attesting temperatures of calcination above 350ºC. The use of a multiphase gypsum plaster as a binder was probably intentional. The treatment of the surfaces, which is used to obtain an aesthetical appearance similar to the natural stone, has also a major influence in the main properties of the final materials. The search for organic compounds showed the presence of animal glues in the inner core and beeswax and oils at the surface. The dynamic moduli of elasticity are extremely high in the samples incorporating anhydrite and the capillary water absorption is almost inexistent. The results obtained intend to contribute to promote sustainable interventions on this type of materials, namely the future development of compatible restoration products

Behind the Light: Pink-lake Paints’ Characterization on a 16th Century Illuminated Antiphonary held by the Biblioteca Pública de Évora – a Spectroscopic Approach

The complete characterization of illuminated paints (pigments, extendersin its full composition (pigments, extenders, binders and any other additives) is a challenging task. If for inorganic materials it is often performed using in-situ and non-invasive analysis, for lake-pigment-based paints it becomes difficult to identify them via a non-invasive approach. This work focuses on the characterization of pink-lake paints present in the illuminations of Manizola 116c codex, a large 16th century Antiphonary produced to be used as a Choir book at the female Cistercian Monastery of São Bento de Cástris, Évora (Portugal). For this, the pink-to-reddish paints of seven representative illuminated capital letters were analyzed by in-situ fiber optic reflectance spectroscopy (FORS), and the results compared with 48 FORS reference spectra of historical accurate reconstructions of pink-lake pigments produced from four late-medieval-to-renaissance treatises. PCA analysis was performed on the 48 reference spectra, and the historical spectra projected into the PCA model. With this approach it became possible to identify the use of cochineal lake-pigments for either the roses and the reddish-pink paints. To corroborate the results, two micro-samples representative of these reddish-to-pink-lake paints were analysed by LC/DAD/MS

Qualitative evaluation of fruits from different Opuntia ficus indica ecotypes/cultivars harvested in South Portugal

Opuntia ficus‐indica fruits have an important nutritional value and show several biological properties. This work studied the fruit physicochemical characteristics of two wild ecotypes (“Green” and “Orange”) and two cultivars (“Rossa” and “Gialla”) from Portugal. The results showed that the largest and heaviest fruits were those from ecotype “Orange,”, whereas the wild ecotype “Green” had fruits with firmer flesh. The fruit peels of cultivars “Rossa” and “Gialla” presented the highest fibre content. Glucose was the major carbohydrate in the fruits, particularly in the peels. Malic acid was the sole organic acid in both peels and pulps of all samples. The betacyanins’ content was higher in fruits of the “Rossa” cultivar, and the higher betaxanthins’ content was present in the peel of the cultivar “Gialla.” Peels of all samples generally had higher amounts of betalains than the pulps. The peel was a better scavenger of DPPH and ABTS free radicals than the pulp

A multi-analytical approach for the study of Neolithic pottery from the great Dolmen of Zambujeiro (Évora, Portugal)

The Great Dolmen of Zambujeiro (GDZ), built between the )th and the middle of the Crd millennium BC, between the late Neolithic and Chalcolithic periods, is located on the right margin of Peramanca riverside, in Valverde, municipality of Évora (Portugal), and is one of the largest megalithic monuments on the Iberian Peninsula. The GDZ was identified and excavated between (lm) and (lmp by Henrique Leonor Pina and is classified as a national monument since (lo). During the p's decade of last century, due to the monument degradation, some conservation works were carried over under the direction of Caetano Mello Beirão, and some archaeological research was also performed

Preserving European paintings in Asian environment. The case of Goa Cathedral former altarpiece

How to preserve a set of paintings made with European materials and taken to South Asia in the 16th century? A set of seven paintings belonging to the first altarpiece of Goa Cathedral now remain in its sacristy. Art history states that these paintings, assigned to the painter Garcia Fernandes, were produced in Lisbon circa 1530 and carried to Goa shortly after, Serrão (2011), Reis-Santos (1957). Presently, the conservation state of the paintings indicates urgent treatment. The most damaged paintings show significant loss of the original chromatic layer. This is mostly due to the high temperatures and relative humidity existing in tropical climates, such as Goa, different from the European. The Baltic oak support is covered with ground layers of calcium suphate, which present fissures and great losses due to the shrinkages of the wood support. The high reactivity of the ground materials to water is also a factor leading to specific material deterioration and degradation mechanisms. In comparison with the paintings of the same period produced in Portugal using the same materials, we verify a much higher degradation of the state of conservation. To access the procedures for preservation and restoration of this set of paintings we must take into account the possible degradation mechanisms of the constituent materials brought by specific environmental factors. This paper discusses the degradation problematic of this specific set of paintings taking into account their particular environment, while bringing results on the materials used. Concluding, this study will allow the knowledge on how to preserve and restore one of the most ancient sets of European paintings in India, kept since the 16th century in tropical climate

Elementos decorativos quinhentistas no convento dos Capuchos (Parques de Sintra - Monte da Lua)

Reaberto ao público em 2001 o convento dos Capuchos encontra-se num avançado estado de deterioração, nomeadamente ao nível dos revestimentos. Neste sentido foi possível identificar, sob pinturas murais do Séc. XVIII, a existência de uma cor negra que revestiria – barramento - a generalidade dos espaços interiores. No âmbito do diagnóstico de conservação conduzido pela empresa In-Situ a pedido da Parques de Sintra-Monte da Lua foram recolhidas amostras de materiais de revestimento e decoração quinhentista do convento (argamassas, barramentos, embrechados e embutido), com vista à sua caracterização

Analytical characterization of the palette and painting techniques of Jorge Afonso, the great 16th century Master of Lisbon painting workshop

In this work, a study on a set of paintings from the most significant altarpiece assigned to Master Jorge Afonso (c. 1470–1540) painting workshop is presented. This altarpiece is composed by fourteen paintings made to the church of Convento de Jesus, in Setúbal, Portugal, and was made circa 1517–19/1530, according to art-history. This set of paintings is compared to one of the other most important Portuguese altarpieces from the 16th century: the panels of the Round Church of the Convento de Cristo, in Tomar, made circa 1510–1515. The aim of this study is to characterize the wooden support, pigments, ground layers materials and technique used in Jorge Afonso workshop by means of complementary analyses. A dendrochronological approach was made in order to corroborate (or not) the historical date initially assigned. Infrared photography (IRP) and reflectography (IRR) allowed the study of the underdrawing technique and macro photography (MP) was used to recognize overlapping layers technique. Cross-sections from the paintings were examined by optical microscopy (OM), and analyzed by μ-X-ray diffraction (μ-XRD), Energy Dispersive X-ray Fluorescence spectroscopy (EDXRF), Scanning Electron Microscopy with Energy Dispersive X-ray Spectroscopy (SEM-EDS), micro-Raman spectroscopy (μ-Raman), micro-Fourier Transform Infrared spectroscopy (μ-FTIR), Pyrolysis Gas Chromatography Mass Spectrometry (py-GC/MS). The characterization of the palette and ground layers and the study of the overlapping of paint layers brought a new insight of the adopted painting techniques by the most important group of painters working in Portugal in the 16th century - the Lisbon workshop, leaded by Master Jorge Afonso