Vaterite in the mortars of a mosaic in the Saint Peter basilica,Vatican (Rome)

The vaults of the Saint Peter basilica in Vatican (Rome) are decorated with mosaics whose realisation is dated to the end of the 16th century. The mortar layers beneath the mosaics are realised with the so-called “Roman stucco”, a kind of mastic specifically employed as a binder in the mosaic's supporting layers. Its empirical recipe was known and reported by 18th century authors, accounting for the use of lime, travertine powder added to a mixture of herbs and linseed oil. A recent restoration of the mosaics has allowed to characterise the mortars from a compositional point of view by individuating the inorganic mineralogical fraction and by chemically characterising the organic components. The study of stucco samples has been performed through polarising microscope observations, X-ray diffraction (XRD) analyses, thermal analyses (TA) (thermodifferential-DTA and termogravimetric-TGA analysis), Attenuated Total Reflectance-Fourier Transform Infrared (ATR-FTIR) spectroscopy, pyrolysis-gascromatography (PY-GC)–mass spectrometry. The analyses have allowed to distinguish between original stucco, produced and utilized at the same time of the realisation of the mosaics, and other mortars, presumably employed in later times during restoration interventions. The outcomes of the mineralogical investigation and TA indicate the presence of four different types of stuccos, here considered as four characteristic groups. The mineralogical analyses indicate that all the samples are constituted of two main phases: calcite and vaterite and the TA, beyond the quantification of the calcium carbonate content, have shown the presence of organic components in the stucco. The organic fraction was characterised by PY-GC–mass spectrometry, confirming the presence of the linseed oil cited in the ancient recipes. The very interesting outcome of this study is the occurrence of the rare calcium carbonate polymorph vaterite. The ATR-FTIR spectroscopy on the stucco gives further contribution to a better understanding of the FTIR spectrum of the rare mineral and an explanation of its formation is tentatively given.     

Quantification of mercury in XVIII century books by Energy Dispersive X-Ray Fluorescence (EDXRF)

This work describes the quantitative analysis of mercury present in the ink used to colour some books of XVIII century. The mercury content was determined by Energy Dispersive X-ray Spectrometry. This is a non-destructive technique which allows elemental identification and quantification (Z > 13) by atomic physics processes. The organic pigments cannot be identified by this technique, taking into account that its composition is mainly C, O and H. Levels of 2 wt.% and 4.5 wt.% were measured in 1756 and 1753 books respectively. No significant amount of mercury was observed in other red books, on a total of 11, all from XVIII century: 1720, 1732, 1753, 1756, 1780, 1798, 1800. More than one book for each year were analysed. The studied books belong to a private collection, and were selected taking into account the age and the reddish colour of their external parts. High content on Fe were observed in some of the books. This work highlights the application of a physics technique in a very important aspect for art and cultural heritage conservation and restoration, considering that high levels of toxic elements might be found in ancient documents. It is of great importance that preliminary elemental analyses are performed on ancient documents before handling them, because they might constitute some danger for restorers, conservators and collectors. This work highlights, for the first time, the danger of some ancient books. They might contain a very high concentration of mercury, which is toxic for the organism. This is also a particularly important problem of public health never mentioned in literature before.     

Historical plasters on light thin vaults: State of conservation assessment by a Hybrid ultrasonic method

Historical plasters on light thin vaults, usually made by mats of reeds nailed to an upper wooden framework, were used in several historical and monumental Italian buildings and churches built between the 16th and the 19th century and almost all of the historical Italian theatres built between the 18th and the 19th century to cover the theatre-hall and to improve its acoustic properties. The non-destructive inspection of these structures is very important, but traditional inspection techniques are usually limited in resolution, which may be a problem for detection of defects at a very early stage. The paper presents the development and application of a high-resolution inspection technique based on a hybrid ultrasonic method, where a contact emitter probe and a non-contact air-coupled receiver probe are used. Results show the effectiveness of the method on laboratory samples and propose an inspection procedure for in-field application.     

The palette of the Macchia Italian artist Giovanni Fattori in the second half of the xixth century

Giovanni Fattori (Livorno 1825–Firenze 1908) is the most representative artist of the Macchiaioli's current, an early group of Italian plein-air artists, whose work anticipates, in the xixth century, that of their younger contemporaries, the French Impressionists. The study, performed by a multidisciplinary team made up of scientists and conservators, presents the results of the scientific characterization carried out on a group of 10 paintings made by Fattori between 1854 and 1893 and shows the way he used complex mixtures of a large variety of traditional and synthetic pigments, ranging from lead white, found pure and also extended with calcium carbonate, natural barite and gypsum to zinc white, from red ochre to cinnabar and vermilion, from yellow ochre and Naples yellow to chrome yellow, cadmium yellow and zinc yellow, combined with many other ones reported in details. This paper highlights the evolution of his painting technique during a time of great technological and social innovations and puts forward some hypothesis on his awareness about manufactured pigments, i.e. tube paints recently introduced into the artists’ circles. The wide range of pigments and their different quality among the same synthetic products suggest that the artist used all the available materials, and that picking out the pigments he retained the early xixth century artists techniques, such as the use of mineral earths and Prussian blue, similarly to his contemporary Italian artists Federico Zandomeneghi and Telemaco Signorini, but he also experimented new and peculiar pigment mixtures in the making of “colored darks” and an innovative use of the grounds in the final composition, that are also distinctive features of the French Impressionists. This work is aimed at contributing to overcome the lack of a comprehensive overview on the widespread historical and scientific data collected up to now on the Italian paintings in the xixth century, which has been severely underestimated with respect to previous art movements.     

The rediscovery of Benevento Roman Theatre Acoustics

This study reports the acoustic history of the Benevento Roman theatre, from its origins in the Roman period to today. The theatre, built in the second century A.D., was abandoned following historical affairs – e.g. barbaric invasions – and natural events (earthquakes, floods, etc.). The building materials were used during the Langobardic Age for the construction of defensive walls and for the adornment of churches and buildings. During the following centuries some houses were built in the theatre. At the beginning of the 1900s, the dominating houses were demolished in order to bring to the light the buried parts of the theatre and to consolidate the structures. The recovery work ended only in 1950. The theatre is nowadays not only an ancient monument, but also the centre of important social activities with national and international festivals of music, dancing and drama. Using a software for architectural acoustic, and with a 3D theatre virtual model, we predicted the acoustic properties during the Imperial Age. With acoustic measurements carried out in situ, we evaluated the acoustic properties in the current state.     

Euganean trachytes: discrimination of quarried sites by petrographic and chemical parameters and by magnetic susceptibility and its bearing on the provenance of stones of ancient artefacts

This paper reports petrographic and chemical data and magnetic susceptibility values for trachytes of quarries recognizable within the Euganean Hills and sets out diagnostic parameters for these rocks. The diagnostic scheme proposed is basic for the definition of provenance of trachytes used in ancient artefacts spread over northern Italy. Trachytes were extensively used by the Romans for paving Via Aemilia, the most important road in the Po Plains connecting Ariminum (present-day Rimini on the Adriatic sea) to Placentia (present-day Piacenza on the Po river). Remains of the trachytic flagstones (basoli) used for paving segments of Via Aemilia crossing Regium Lepidi (present-day Reggio Emilia) and Bononia (present-day Bologna) have been characterised petrographically, chemically and also using magnetic susceptibility data. The discriminating scheme proposed here for the Euganean trachytes has been applied to the data obtained for basoli and thus the provenance of each investigated block has been inferred. The rocks sampled at Regium Lepidi mostly come from Monselice (only a few blocks from Monte Oliveto and Monte Merlo) and those of Bononia come mostly from Monte Merlo and, subordinately, from Monte Oliveto and Monselice (only one sample from Monte San Daniele). The dominant provenance of blocks, which is different in the two colonies distant by less than 50 km, suggests that the two segments of Via Aemilia were not built simultaneously.     

The contribution of numerical simulation for the diagnosis of the conservation of art objects: Application to Antonio Santucci's armillary sphere of the 16th century

Antonio Santucci's armillary sphere is one of the symbols of the wealth of the world cultural heritage: it is an elaborate representation of the geocentric universe as it was known at that time. Its exceptional dimensions (more than 3 meters high) make it an object which is considered as a complex structure, built with a technique of mixite made of nail-laminated timber. Constructed at the end of the 16th century, this sphere has suffered wear and tear, mostly due to the combined effects of gravity loads over time and environmental agents (such as variations in the relative humidity of the air), as well as means of exposure of the object.The purpose of this research project is to study delayed phenomena, and it lies in the evaluation of the coupled mechano-sorptive effects likely to generate a critical state which would threaten the stability and the durability of the structure. This study highlights a problem which is already very real, even though irreversible consequences may not appear until the future. This work shows the importance of taking into account the variations in relative humidity undergone by the environment in which the sphere is exposed. These changes are at the origin of increasing deformations which could soon become prejudicial to the satisfactory conservation of the object.     

Mortars,pigments and binding media of wall paintings in the ‘Carrera del Darro’ in Granada,Spain

The Carrera del Darro is a street within the city of Granada, Spain, which is emblematic owing to the architectural value of its buildings, to its significance for the urban structure of the city and to the implications it has for the surroundings of the Alhambra. Our study concerns the chemical analysis of the mural paintings on four façades, corresponding to numbers 23, 25, 27 and 29 of the Carrera del Darro. From the analysis of the mortar, it may be concluded that the composition is very similar, though not identical, in the four paintings studied: a limestone mortar. Ochre, white, black and red were used for the decoration of the four façades; green pigment was also observed in the second decoration of no. 29. The results of the morphological examination and EDX microanalysis of the paint samples are shown. By means of the thermogravimetric analysis we established the existence of an organically derived compound. After the existence of an oleaginous binder had been discounted by gas chromatography/mass spectrometry (GC/MS) analysis, we continued with the extraction and determination of proteins by spectrophotometry analysis, detecting low levels of proteins in the paint on the four façades analysed. The study was completed by evaluating the influence on the deterioration of the paintings by the possible surface presence of salts (such as nitrates or chlorides) and organic compounds.     

Chemical and lead isotope compositions of lead artefacts from ancient Thracia (Bulgaria)

Using inductively coupled plasma–atomic emission spectrometry (ICP-AES), atomic absorption spectrometry (AAS) and instrumental neutron activation analysis (INAA) the concentration of Ag, As, Au, Bi, Cu, Fe, Ga, In, Ni, Sb, Sn, and Zn in 53 samples taken from archaeological finds dated to 4th–2nd century BC and found in the territory of ancient Thracia was determined. Additionally using inductively coupled plasma–mass spectrometry (ICP-MS) and MS for determination of the lead isotope ratios in the samples was carried out. On the basis of these analytical results using cluster analysis for grouping the samples on the bases of the similarity in chemical and isotopic content and the available data from the literature for lead ore deposits in the Balkan Peninsula, the geological origin of the investigated archaeological finds was evaluated. That confirms the expectation that sources of lead might be almost all possible deposits of lead ores on the Balkan Peninsula—from Lavrion through Chalkidiki to the Rhodope mountain. The result indicates that the Thrace did not utilize one single lead source continuously but that lead was provided according to availability from different production centers.     

Provenance study of ancient Iranian luster pottery using PIXE multivariate statistical analysis

Although luster potteries are frequently excavated at archeological sites in Iran, a thorough scientific study of their provenance has not yet been performed. In this work, 43 pieces of Iranian luster pottery (bowl, dish and tile) excavated from Rayy, Kashan, Maragheh, Alamoot, Takht-i-Sulayman and Jiroft were analyzed in order to investigate their origin. The luster shards which belong to Seljuks and Il-Khanids dynasties (12th–13th centuries) were analyzed using proton induced X-ray emission (PIXE) technique. To classify the fragments according to their location and origin, principal component analysis (PCA) and hierarchical cluster analysis (HCA) were applied to the chemical compositions of the body of the shards. We were able to classify the samples into three distinct groups using PIXE.     

Continuous monitoring of wooden works of art using fiber Bragg grating sensors

In recent years the control and monitoring of works of art has gained more and more importance. In particular, works partially or totally realized with wood, such as polychrome sculptures, painted panels or Crucifixes, are highly sensitive and delicate and thus need a particular attention. The wooden support is, in fact, an essential element for the stability of pictorial layers: the color lies on a preparation, which in turn, is anchored to the wood. Wrong conservation methods, i.e. in an environmental climate that is not controlled, or intrinsic mechanical stresses, can warp such structures, and the effects can be irreversible and destructive to the painted layer. The use of fiber Bragg grating (FBG) sensors for the quasi-distributed, in situ measurement and continuous monitoring of deformations in painted wood panel is proposed. In order to demonstrate the applicability of FBG sensors to painted wood panels, a wooden support, made using the same 15th–16th century techniques, was prepared in the Opificio laboratories. A number of Bragg grating sensors were affixed in several critical points, on the back and front sides and on the strengthening cross-beams, in order to detect deformations in the panel dependent on the variations in the environmental relative humidity (RH). Measurements during the removal of the cross-beams are also reported. The results of measurements have shown the applicability of FBG sensors for the continuous in situ monitoring of valuable wooden objects and works of art.     

A definition of cultural heritage: From the tangible to the intangible

The aim of this work is to analyse the evolution of the concept of cultural heritage in West European states. In the last decades of the 20th century, the term “heritage” was characterised by expansion and semantic transfer, resulting in a generalisation of the use of this word, frequently used in the place of another, such as, monument and cultural property. However, all these terms are not able to cover the same semantic field. Starting by the reflection on the semantic evolution of the notion of cultural heritage in France, we approach to the international definition of heritage given by the directives, charters and international resolutions in order to define a global outline of the meaning of heritage that is not just limited to a particular national dimension. From a purely normative approach, one went to a less restrictive approach, one based on the capacity of the object to arouse certain values that led the society in question to consider it as heritage and therefore, to a further step in which heritage is no longer defined on the basis of its material aspect. This development has also made it possible to recognise intangible cultural heritage, which was ignored for a long time, as heritage to be protected and safeguarded.     

A new family of high viscosity polymeric dispersions for cleaning easel paintings

The procedures for making and applying a new family of high viscosity aqueous polymeric dispersions based on poly(vinyl alcohol)-borax (PVA-borax) matrices are presented. A specific system of this type has been used to remove an oxidized varnish coating from the surface of “Coronation of the Virgin with Saints”, a 15th century egg tempera painting on wood by Neri di Bicci (Florence, 1418–1492). FTIR spectra showed that the oxidized varnish was constituted of highly aged shellac resin. Good cleaning performance was attained when the liquid portion of the dispersion consisted of a mixture of water and acetone. Rheological investigations indicate that the acetone content does not affect the mechanical properties of the polymeric dispersion. Those mechanical properties permit easy removal of the cleaning agent simply by peeling it from the surface by means of a forceps or spatula once it has carried out its cleaning function. Optical microscopic and FTIR investigations show that the cleaning agent is able to remove the oxidized varnish coating from the surface of the Neri di Bicci painting without leaving detectable residues.     

The wood of “C” and “F” Roman ships found in the ancient harbour of Pisa (Tuscany, Italy): the utilisation of different timbers and the probable geographical area which supplied them

During the excavation of the Etruscan and Roman harbour of Pisa, several shipwrecks were found. The wooden timbers constituting the ship C and ship F (which date back to the first and the second century A.D., respectively, as attested by archaeological findings) were selected in order to collect information about the technological knowledge of the time. Pinus pinaster Aiton was essentially utilised for the planking of ship C and Quercus sp. caducifolia for that of ship F. The choice of timber for the other parts of ship C hull was much more differentiated. Ship C seems to be built in a careful way and its characteristics when added to its overall lightness, seem to reflect its use as a higher capacity boat built for sea sailing. Ship F seems more linked to short voyages in inner fresh waters. The utilisation of different woods was linked not only to the technological characteristics of wood, but also to their easy availability. Palynological analysis, carried out on the clay sediments embedding the shipwrecks, has shown that the flora of Pisa area in that time period would have allowed the acquisition of all the timber species used for both the ships’ construction, with the exception of the fig wood. However, a foreign origin of the timber from somewhere else in the Northern Mediterranean area has not been excluded.     

Metrological definition and evaluation of some mechanical properties of post-medieval Neapolitan yellow tuff masonry

The knowledge of the morphological and mechanical properties of masonry walls is very important for the refurbishment of ancient buildings, particularly when the requirements of both structural safety and historical preservation must be fulfilled. The masonry is not of homogenous material: its mechanical properties depend on stones, mortar, and texture which are very variable due to their dependence on the historical periods and the geographical area of the erection. For this reason, a deep knowledge of masonries built in different sites and historical periods is essential in order to evaluate both the capacities of bearing vertical load and the seismic vulnerability of the masonry structure. Three fundamental typologies of tuff masonry have been defined: they are the characteristics of different historical periods from the XVI to the XX century. The models are in full-scale in order to reproduce the three defined chronotypes. Original tuff stones quarried in the corresponding historical period, mortars similar to the original ones, reproduced according to ancient documents and original constructive techniques have been used for the construction of the specimens. Compression tests performed in displacement control have been carried out on the masonry models in order to determine the maximum resistance of the material and the corresponding strain, the ultimate strain and corresponding residual strength. In this paper, the procedure used for making the specimens and for experimentally evaluating the mechanical properties of post-medieval Neapolitan yellow tuff masonry are illustrated and the obtained results, even in terms of plastic capacity of these kinds of masonry, are reported.     

Urban regeneration in the context of post-Soviet transformation: Lithuanian experience

Our research concentrates on the countries, which had emerged after the collapse of the Soviet bloc, and the possible distinctive influence of the social and institutional environment of these countries on the process and outcomes of city center regeneration. The theoretical section includes the definition of the main concepts used in our research. First of all the countries undergoing the post-Soviet transformation were defined and then the concept of “urban regeneration” was explained. Here we also distinguished the main features of societies and institutional environment of the post-Soviet countries including the collision of different sets of values and lack of conscious value orientations and value systems, lack of individual initiative and personal responsibility, low level of participation in public domain, tendency towards non-transparent decision making, culture of complaint, climate of mistrust, increasing uncertainty and pessimism. In the section of results we had elaborated and discussed the hypothesis that these features affect the image and treatment of the historic built environment and especially of historic urban centers. Further we distinguish three dimensions – features of urban space, governance structures, and social milieu – and, based on literature and Lithuanian experience, distinguish what features of these dimensions and how make it easier or inhibit the urban regeneration. In the concluding sections we outline the basic findings and further research proposals and present the summary matrix of strengths, weaknesses, opportunities, and threats of urban regeneration in the context of post-Soviet transformation. The matrix could be useful both for the future research and for the decision making in practice of city center regeneration. From the preset outcomes of our research, we conclude that social and institutional context is crucial in the city center regeneration and in heritage preservation in general and the ideas and principles widespread in Western Europe and the United States cannot be directly and straightforwardly imported into the context of post-Soviet transformation.