Study of the stability of a series of synthetic colorants applied with styrene-acrylic copolymer, widely used in contemporary paintings, concerning the effects of accelerated ageing

This study examines the materials of a contemporary pictorial artwork, belonging to the Macedonian Museum of Contemporary Art in Thessaloniki (Greece), and needing conservation. The combined use of micro-FTIR and micro-Raman spectroscopy allowed the identification of almost all painting materials. Moreover, the stability of a series of synthetic pigments towards accelerated ageing is investigated in applications using the contemporary binding medium styrene-acrylic copolymer. The pigments in question are: Hansa yellow PY3 and PY74, quinacridone PV19 and PR122, naphthol AS PR112, phthalocyanine green PG7 and blue PB15, dioxazine PV37, van Dyck brown PBk11, ivory black PBk9, and titanium dioxide PW6. The organic pigments were applied alone or mixed with titanium dioxide, in rutile form or as a mixture of rutile/anatase. The experimental swatches were subjected to ageing tests, and subsequently studied as to colour changes by means of colorimetric measurements, and as to the molecular structure differentiations by infrared spectroscopy in reflectance mode. The ageing tests included exposure to high temperature and humidity (90 °C, 60% RH) and to ultraviolet radiation (350 nm, 30 °C and 50% RH, with a substantial temperature increase at 90 °C for 3 days). The greater colour difference is caused by high temperature and humidity, whereas paint layers containing TiO₂, and especially the mixture of the forms rutile/anatase, prove very susceptible to ultraviolet radiation, demonstrating a significant colour difference and extended molecular changes.     

Spectroscopic methods for the analysis of celadonite and glauconite in Roman green wall paintings

One set of samples from wall paintings of the X^th Regio of Italy containing green colours was analysed exploiting different spectroscopic techniques, aiming to identify the pigments used. The possibility to distinguish between glauconite and celadonite, the most common green pigments used in such paintings, was of particular interest. Samples of celadonite from Monte Baldo and glauconite from Belgium were considered as standard materials for comparison. The results obtained using FTIR, EDS, AAS, Colorimetry, Raman and EPR spectroscopies were compared for the identification of the green pigments.     

Comparative projects and the limits of choice: ethnography and microfinance in India and Paraguay

In recent years, microfinance – the suite of financial products offered to the poor – has been widely adopted in international development policy. Organizations around the world have replicated this model successfully. This essay takes the comparative case more explicitly to read against the tendency to understand microfinance as the globally institutionalized and realized norm, and local unruly credit economies as the exception. We go beyond comparing credit in India and Paraguay in order to illustrate how comparison is actually central to the banking practices of microfinance. Moreover, it is the collaborative anthropological project that helps to show this, allowing not only for empirical grounds of comparison, but also raising theoretical and methodological questions of comparison itself. In juxtaposing microfinance in our two fieldsites, we find that as credit proliferates globally, so do the comparative projects both of borrowers and lenders in the disparate worlds of Kolkata and Ciudad del Este. At the same time, these were constrained by the global financial comparisons between countries made by investors. Ethnographic methods are vital for understanding how microfinance becomes part of a wider repertoire of financial strategies used by women while simultaneously offering the grounds for women to undertake their own acts of comparison.     

Unusual coin from the Parabita hoard: combined use of surface and micro-analytical techniques for its characterisation

Out of the staters collection of the National Archaeological Museum of Taranto, during the full examination of about one hundred coins minted by the Greek colony of Taras between the V century BC and the III century BC, our attention has been devoted to a lead coin, which has been regarded for many years as a genuine silver coin. This artifact, entry number 13 in the inventory list for the Parabita hoard, has been studied with the combined use of surface and micro-analytical techniques (SEM, EDX, PIXE, XRD). The joint use of different analytical techniques allowed us to obtain information about the morphology, the structure and the chemical composition of the analysed coin, that revealed a lead core coated with a bi-layer of copper and silver.     

Non-invasive multi-technique investigation of artworks: A new tool for on-the-spot data documentation and analysis

The main advantage of a multi-technique non-invasive artwork investigations relies on the use of different spectroscopic techniques that give rise to complementary information. Despite the artworks complexity, this approach allows great insight into the artwork composition and alteration phases. However, difficulties arise from the great amount of heterogeneous interconnected data that has to be stored for a prompt analysis and preserved. A suitable tool to handle and analyse all the information on the fly is therefore crucial to optimize work, specially in in situ investigations. In this paper we present MOVIDA, a new tool for the data management and analysis of non-invasive investigations in the Cultural Heritage field that not only allows the digital preservation of all the information and knowledge, but can also be used as an analytical tool while the investigation is being developed. The software can be installed on any computer to record, elaborate and analyse the data on-the-spot. All the data generated can be managed within the same application and the information can be easily consulted, compared and related to the corresponding areas of the artwork. The software is self-comprehensive and user-friendly and can be used by all the professionals involved in the investigation and preservation of Cultural Heritage whatever their background and computer skills are.     

The combined use of IRT and LDV for the investigation of historical thin vaults

Correct interventions on cultural heritage should have as their starting point an accurate diagnosis of its health, in order to design a compatible care. NDTs seem to offer a promising way in this sense. This paper deals with the combined use of IRT and LDV for the investigation of historical thin vaults made by timber arches, reeds, and plaster and it demonstrates that they can effectively support a deeper knowledge of these vaults as it concerns the presence of detached areas among the different mortar layers of the plaster and of detached areas among the mat of reeds and the nailed connection with the wooden bearing elements. This is a very important goal because these ND methodologies can be employed only on the lower surface of these vaults and sufficiently far from it, and they do not have any mechanical interaction with the historical, eventually frescoed or stuccoed, plaster, thus saving money and time.     

The editorial playlist as container technology: on Spotify and the logistical role of digital music packages

ABSTRACT

This article explores the role of editorial playlists in Spotify’s streaming economy. In particular, it approaches Spotify’s playlists as container technologies – i.e. technical solutions that assemble, preserve, and transport music objects and thereby uphold logistical operations within the music industry. Such an approach seeks to complement previous research concerning playlists, which has often analyzed their emotional and affective dimensions but paid less attention to how playlists enhance calculative, mathematical, and logistical retail flows within the online music economy. On the one hand, the article considers how playlists – like containers in general – materialize principles of modularization and automation in ways that enhance control and remote oversight. On the other hand, it discusses how the playlist is far from a perfected means of measurement and control, and sometimes acts as an unruly transport device. Ultimately, the article shows how the playlist format occupies an uneasy position between order and disorder within the digital music economy which has not yet been fully accounted for in the context of music-oriented media studies.     

3D preserving xviii century barroque masterpiece: Challenges and results on the digital preservation of Aleijadinho's sculpture of the Prophet Joel

We present our recent efforts in the digital preservation of a set of baroque sculptures made by Antônio Francisco Lisboa, known as O. Aleijadinho, which is an important American baroque artist. The set was made in the beginning of the xix century and is composed of 12 near real sized sculptures, hand-carved in soapstone. These sculptures represent 12 of the 16 prophets from the Holy Bible and are part of a UNESCO World Heritage Site. Our group has been collaborating with UNESCO in a project that aims to preserve all these statues. We hereby present our initial efforts, consisting of the 3D digital preservation of the Prophet Joel sculpture. We developed a complete 3D digital preservation pipeline composed of four main stages: data acquisition, 3D reconstruction, texture generation and 3D model visualization. By evaluating our results in this first sculpture, we discuss the improvements we conceived before applying our pipeline in the remaining ones. Finally, we present the 3D model of the Prophet which registers the sculpture's current state and will be used in restoration, research and educational activities. We believe this contribution may be useful to guide further research on similar scenarios, showing how to avoid some practical mistakes and achieve good results.     

Historical coastal urban landscapes digital documentation and temporal study with 2D/3D modeling functionality: The case of Thessaloniki,Greece

The study refers to the visual representation of the coastal front of the historical center of Thessaloniki in northern Greece and its changes that have occurred through the years. Most of the old town was destroyed by fire on August 18, 1917. A few years later, the French architect and archeologist Ernest Hébrard proposed the reconstruction of the city centre, but his plans were never fully implemented. Since then, a series of interventions changed the form of the old town and consequently the coastal cityscape. The research was initially based on the photogrammetric processing of archive aerial images (1938) of Thessaloniki's city centre. Besides the vertical images, high oblique aerial images dated back to 1932, proved to be a significant source of information. A rich archive of old photographic material, sketches, drawings and gravures of the coastal forehead of the city was also used. Ortho-images of the coastal front, derived from laser scanning (2010), and a 3D model of the historical city center, derived from the stereo photogrammetric process of aerial images (1990), contributed decisively at the multi temporal study of the city front. The main outcomes of the present documentation study are the 3D representation (at scale of 1:200, accuracy 5 cm) of temporal changes of a part of the coastal front of the historical center of Thessaloniki and the 2D representation (at scale 1:100, accuracy 1–2 cm) of these changes with respect to variations on skyline, lacunas, interventions in old buildings, etc.     

Characterisation of 15 century red and black pastes used for wall decoration in the Qijmas El-Eshaqi mosque (Cairo, Egypt)

The use of coloured pastes for inlaying marble and limestone wall panels is one of the ornamental techniques that were widely used during the Mamluk period in Egypt (1250–1516 AD). Red and black pastes from Qijmas El-Eshaqe mosque (1482 AD) in Cairo were studied to identify their main components. The study of the samples involved the identification of the pigments, additive materials and organic binding media. The study was performed using various analytical methods such as polarising microscopy (PLM), scanning electron microscopy equipped with energy dispersive X-ray analyser (SEM-EDX), inductively-coupled plasma (ICP-AES), X-ray diffraction (XRD) and Fourier-transform infrared spectroscopy (FTIR). These complementary analytical techniques provide precise identification of inorganic and organic substances used in the pastes. The results indicated that the red pigment is mainly obtained from red ochre containing hematite, whereas amorphous carbon (bone black and charcoal) was used to obtain the black colour. Both samples contain calcium sulphate, which was used to give some hardness to the pastes. Beeswax was used as an organic medium in both pastes. The study provides the information required for the conservation of the coloured paste ornaments.     

Archaeometric and geological constraints for the provenance of carbonatic breccias used in monumental works along the Flaminia Consular Road (Umbria-Marche, Central Italy)

Along the Umbria-Marche stretch of the Flaminia Consular Road (220 B.C.) several archaeological finds of the most important monumental works, are well preserved. The stones, employed to build many bridges, substructions and sewerages, are represented by carbonatic breccias whose geological environment of formation and source areas had never been established. On the basis of mineralogical, petrographic and micropalaeontological analyses, two groups of these lithotypes employed in Roman age were distinguished: “monogenic carbonatic breccias” only constituted by clasts of the Maiolica Unit (Late Jurassic – Early Cretaceous) and “polygenic carbonatic breccias” made of fragments (in different proportions) of Calcare Massiccio (Early Jurassic), Corniola (Early Jurassic), Maiolica (Late Jurassic – Early Cretaceous) and Scaglia Rossa (Late Cretaceous – Early Paleogene) Units. The possible source areas of the breccias are compatible with stratified slope-waste to scarp-base deposits of periglacial origin belonging to the Upper Pleistocene. In particular, among the seven investigated areas, we pointed out the most probable provenances (Monte Faeto-Colle, Costacciaro, Scirca, Foci, Secchiano) along the flanks of the Apennine Mesozoic chain of the Umbria and Marche regions. Although the Romans could have exploited the whole thickness of some outcrops (now disappeared) of these carbonatic lithotypes at the deepest part of the valleys, we have constrained a local provenance of the breccias so commonly used in the monumental works of the Flaminia.     

Documentation of soiled and biodeteriorated facades: A case study on the Coliseum,Rome, using hyperspectral imaging fluorescence lidars

Non-invasive documentation of historic façades with fluorescence lidar techniques can provide helpful information for the cultural heritage sector, especially when large areas outdoors are to be examined. This paper presents a case study of the Coliseum, Rome, where both cleaned and heavily soiled areas of the monument were scanned and analysed with two fluorescence lidar systems. Biodeterioration processes were also addressed during the experiment, with the aim of assessing the colonisation extent on selected areas of the monument. Results show the usefulness of a mobile fluorescence lidar system for documentation and survey of large surfaces with complex conditions without limiting the public access to the monument.     

The scientific investigation for the study and conservation of the wooden model of S. Maria della Consolazione's church (Todi,Italy)

The focus of this work is the wood polychrome model of the church of S. Maria della Consolazione in Todi, an artefact whose author and historical events are not completely known except a general reference to the construction period of the church (1508–1607 AD). In this study, original and additional materials were examined in order to provide a deeper understanding of the painting and assembly techniques, and a greater awareness of how well preserved the object is, as well as an analysis of previous preservation and conservation interventions. The samples from the painted surfaces were examined by means of micro-Raman spectroscopy, fourier transform infrared (FTIR) spectrometry and internal microstratigraphic analysis. Thin sections of the wood samples were examined under an optical transmission light microscope in order to identify the botanical species. The results shown in this paper suggest the possibility that the original painted layers are made of calcium carbonate white, red ochre and indigo and they were applied by protein binder without any ground layer. Some non-original pigments were found on the model surface like Prussian blue and chrome yellow. Concerning wood components, poplar was characterized both in the original and non-original parts of the model whereas pine species were detected only in the restoration elements.     

A methodology for the identification of glass panes of different origin in a single stained glass window: Application on two 13th century windows

The chemical composition of 11 glass panes originating from two 13th century non-figurative windows were analyzed by means of Scanning Electron Microscopy–Energy Dispersive X-ray system (SEM-EDX). The windows were discovered in the back-wall of the triforium during the restoration of the choir of the cathedral St. Michael and St. Gudule in Brussels (Belgium). In order to determine if these windows were fabricated with glass of different origin or not, the compositional difference between the panes were compared with the variation in composition as a result of the following causes: (1) compositional fluctuation between panes cut from the same sheet of glass, (2) compositional fluctuation caused when panes are cut from different sheets that were made with the same batch, (3) compositional fluctuation caused when the glass is made from different batches at the same production center, and (4) compositional fluctuation as a result of glass produced at different fabrication centers.     

Programmatic choices and the demand for theatre: the case of Flemish theatres

Theatre experts generally agree that the Flemish theatre has flourished artistically over the period 1980–2000. Attendance, on the other hand, has declined significantly. Following Lancaster’s characteristics approach, we identify several output characteristics of individual theatre productions. Using a panel of 59 Flemish theatres, we examine the impact on demand of both these output characteristics and of traditional determinants such as own price, income and the price of substitutes. Differences in the relevant geographical market for touring and non-touring theatres are considered. We find that the nature of the artistic output affects demand. Theatregoers prefer large productions (in terms of cast size), plays by Dutch-speaking playwrights and revivals of old productions. Own price and consumer income have the expected negative and positive effects on attendance. Observed trends toward a decreasing proportion of new plays, an increasing presence of plays by Dutch-speaking playwrights, and increasing consumer income had a stimulating effect on attendance. These trends have been offset, however, by trends toward smaller cast sizes and higher ticket prices as well as by unobserved factors captured by time dummies. The net result has been a considerable drop in attendance.

Guidelines for selecting roofing slate for the restoration of historical buildings and monuments: Two case studies

Slate has been used for centuries as a building material, and many historical buildings and monuments use slate in roofs and structures. When slate roofs must be totally or partially replaced, the structural and aesthetic integrity of the building as a whole must be guaranteed, based on both international criteria for restoration, and on current local legislation regarding historical buildings. For selection of the most appropriate type of slate to use in the restoration of historical slate roofing, we propose the following steps: a) study of the roof's state, b) spectrophotometric determination of the texture and colour of the original slate, c) petrographic study and determination of the weatherability of the replacement slate, and d) location of the original slate quarry area. With all these data it is possible to choose the most suitable type of commercial slate for replacing the original slate. Thus, even in the absence of historical information, with this four-stage process a replacement slate for building restoration can still be selected on clear and justifiable grounds. The present article uses this methodology to examine two case studies of roofing slate restoration.