Journal of Cultural Heritage最新文献

In this work we present the results obtained by different technical analysis in order to perform the characterization of the chromatic richness, the employed materials and the iconographic elements of different fragments of decorated and gilded leather corami coming from the archive of Palazzo Chigi of Ariccia (Rome) and employed, during the 17^th century, as wallcoverings. Different microscopic and spectroscopic analyses have been performed by means of Ion Beam Analysis (IBA) and Macro Area X-Ray Fluorescence (MA-XRF) techniques available at the INFN LABEC ion beam laboratory in Florence and the Scanning Electron Microscopy-Energy Dispersive X-ray Analysis (SEM-EDX) of the Superconductivity Laboratory of the ENEA Frascati Research Center. The results aim to provide the scholar information about the manufacturing process and the materials employed for the production of these peculiar artefacts, also in order to plan the best and most appropriate conservation protocol. In particular, thanks to the SEM-EDX analysis it has been possible to characterize the layered structure of the samples and, specifically, the interface between the leather of the substrate, the metal foil of the so called meccatura and between these and the overlying pictorial layer. The IBA and MA-XRF techniques has helped in characterizing the painting palette employed while IBA has allowed to determine the conservation condition of the silver layer with the hypothesis of the incorporation of the silver leaf into the organic compound of the mecca as its main deterioration phenomena. These complementary techniques provide, therefore, a comprehensive understanding of the materials and iconographic elements of these leather-based artefacts, which is essential for their preservation and restoration as well as they contribute to a better understanding of the deterioration processes they incur.

Ivory trafficking is a multifaceted problem that has long endangered the fate of African and Asian elephants. In field investigations, it is essential to conduct ivory inspections in a nondestructive manner to prevent the inclusion of noncompliant materials. In this research, a practical approach to identify Asian and African elephants’ ivories was developed using an integrated methodology of art history, vibrational spectroscopy, and chemometrics. Spectra were acquired by an FT-IR spectrometer and a fiber optics reflectance spectrometer (FORS) in the Vis-NIR region. The discriminant methods were calibrated with spectra acquired from Asian and African elephant ivory tusks and applied to historic ivory objects (n = 78) of uncertain origin. Models based on the chemometric methods Principal Component Analysis (PCA) and Partial Least Squares -Discriminant Analysis (PLS-DA) were able to successfully classify ivory objects into Asian and African ivory, with an estimated true prediction rate (TPR) of 99 % both for African and Asian ivory samples. This study demonstrated the potential of FT-IR spectroscopy and FORS with chemometric methods as suitable tools for ivory investigations, aiding to the existing set of ivory trafficking prevention methods.

Even though contamination of historical paper by moulds causes aesthetic, physical, and biochemical biodeterioration, dissolving cellulose fibers and inks, the currently applied physical and chemical disinfection methods are either extremely dangerous to human health (ethylene oxide), may harm the underlying support material, or their efficiency is dependent on fungal species, many of which may resist. Therefore, our aim was to test a new paper impregnation agent, aminopropyl-terminated polydimethylsiloxane (ATP), in regards to its biological potency, ease of handling and support material safety. According to the Gelest Inc. (Morrisville, PA 19067) safety data sheet DMS-A31, ATP in solution causes eye irritation, but in dry from is relatively safe. Our biofouling experiments with four cellulase-active fungal strains, originally isolated from historical books, were conducted directly on impregnated and aged paper at verifying concentrations of ATP and at a relative humidity of 95 %. Fungal biofilm development was quantified using micro-invasive fluorescence microscopy and after incubation non-invasive FTIR spectroscopy was also employed. 3D surface topography scan results showed that ATP impregnation at a concentration of 30 % does not harm the visible structural characteristics of the tested paper and no alterations in surface roughness parameters were observed and is therefore safe for the supporting material. At least a 10 % paper impregnation was needed for an effective suppression of fungal biofilm development and tolerance to lower concentrations was species dependent, with Penicillium canescens ZIM-9717 tolerating 1 % of ATP and Aspergillus niger ZIM-9721 tolerating 1 % and 5 % of ATP. Lastly, we have shown that portable “on the spot” non-invasive FTIR spectroscopy in reflection mode can be effectively used for a rapid but highly sensitive detection and monitoring of mould biofilms on paper support materials. This is important, because sampling and fluorescence dye staining in fluorescence microscopy, will harm the integrity of cultural heritage books and documents. Therefore, non-invasive FTIR spectroscopy can provide for an initial overview or insight into the microbiological condition of library and paper materials.

The Bilsk archaeological complex comprises the remains of many structures associated with an impressive Iron Age fortified site and extends over a vast area in central-east Ukraine. Its importance is marked by the presence of apparently imported objects, including some vitreous ones (represented mainly by glass and faience beads), which provide researchers with materials for studying past trade in the area. A representative set of vitreous fragments was subjected to an analytical study with several instrumental techniques (namely: scanning electron microscopy coupled with energy dispersive spectrometry, laser ablation inductively coupled plasma mass spectrometry, micro-Raman spectroscopy and micro-X-ray diffraction) in order to characterise the beads on compositional basis. The complementary data from different techniques revealed a complex picture for the raw materials, identifying several sources of silica and, consequently, several production centres for the items included in the analysed set. This information in turn led to a better understanding of the trade networks that operated in the region between the 7th and 4th century BCE. Colouring and opacifying agents are also discussed.

In an effort to try and improve the dissemination of cultural heritage, in this paper a novel method for the four-dimensional (4D) digitization of artefacts, based on images recorded in the mid-wave infrared spectral range, is presented. Such a method is here applied to ancient manuscripts in the frame of the “Codex 4D: journey in four dimensions into the manuscript” project. In the proposed approach, the three-dimensional geometry of the manuscript is reconstructed by processing the reflectographic images, obtained from different points of view with respect to the artefact, through Structure from Motion techniques. Thermograms obtained by means of Pulsed Thermography are also recorded since they provide a depth-resolved characterization of the artefact that is also integrated into the digital reconstruction along the orthogonal direction to the surface, hereafter referred to as the fourth dimension. The results gathered from humanities and scientific studies, are also mapped onto the 4D model in the form of interactive semantic annotations. The goal of such a reconstruction is to allow users to browse the subsurface elements into the 4D model, thus facilitating the study and the exploration of the manuscripts through the inclusion of information about their literary and art-historical contents, materials, execution techniques, and state of conservation. In addition, virtual and mixed reality environments have been developed for different kind of audience such as expert users and museum public. Despite the experimentation presented here was carried out exclusively on manuscripts, in our opinion the methodology can be successfully applied to other types of artefacts.

This paper evaluates the improvements in wall paintings diagnostic achievable by the synergistic combination of DHSPI, SIRT and MWR techniques. These innovative portable and non-destructive techniques for in-situ diagnostic were tested in laboratory on mock-ups mimicking the real conditions of wall painting defects (such as detachments, cavities and cracks), and on the frescoes painted by Masolino, Masaccio and Filippino Lippi (between 1422 and 1475) in the Brancacci Chapel in the church of Santa Maria del Carmine in Florence, Italy. This research activity was part of the Brancacci Chapel diagnostic and monitoring project, where the assessment of the state of conservation is a mandatory prerequisite for planning the subsequent restoration work. In common practice, restorers make the preliminary evaluation on the state of conservation of the wall paintings by visual and tactile inspection, without the use of any special scientific instrumentation. Cracks, cavities, lack of material, detachments, out-of-plumb and deformation of (non-)structural elements are reported in a condition report to document the state of conservation at a given point in time. In particular, the detachments are recognized by the tap test, but this is a discretionary and highly subjective method. Thus, there is a strong demand for the development of a portable and non-destructive approach that refines this preliminary survey with objective data. Here, we present the results produced by the combination of MWR (useful for the dimensional characterization of hidden defects in the wall) and DHSPI-SIRT to identify the extent of deformations induced by thermal stimulus, providing an objective confirmation of the preliminary investigation performed by restorers, in which the detachments were indicated as “stable”, “not very stable” and “unstable”, i.e., close to falling. The integrated use of these techniques in situ, supported by a laboratory study on ad-hoc prepared mock-ups, proved to be suitable for a quantitative evaluation of damage risk to guide restoration strategy accordingly.

Electrokinetic treatment of masonry for desalination or electroosmotic dewatering depends on a poultice, in which the electrodes are placed, which fulfills several purposes. Poultice composed of kaolinite and CaCO₃ have been shown to have good workability and high pH buffering capacity. In this work, the electroosmotic (EO) permeability is studied in different kaolinite - CaCO₃ mixtures. In addition, the effect on EO of using NaCl as a mixing solution is investigated. A special cell is used to test the EO in the specimens. A phenomenological approach, based on the potential gradient and the flux of solution, was used to calculate the EO flow rate and EO permeability coefficient. Results showed that by increasing the concentration of CaCO₃ in the poultice mixture, the EO flow rate decreased and the poultice with 80 % CaCO₃ and more did not have any EO flow. Furthermore, the ionic strength in the mixing solution decreases the EO flow rate.

Multispectral imaging has long been used in the study of cultural heritage artifacts, particularly manuscripts with low-contrast text. The goal of multispectral imaging systems has largely been to enhance the text by imaging outside the spectral response of the human visual system and by applying various image processing techniques. However, there is a desire to use multispectral images for high quality, true color rendering of the artifacts as well. We use two multispectral imaging systems in this work. One of them is the Multispectral Imaging System for the study of Historical Artifacts (MISHA) which has been demonstrated to have significant utility at a lower cost and better ease of use compared to commercially available systems. This system was specifically designed and built for the purpose of imaging artifacts, particularly manuscripts and works on paper with illegible text due to deterioration and other environmental causes. Given this goal of “discovering” low-contrast text (and other features) on planar objects, the system has not been optimized for color reproduction purposes. The second system is a commercially available MegaVision EV^TM Spectral Imaging System. This system is also used for cultural heritage imaging. In this work, we develop an approach to colorimetrically characterize these cameras and illumination systems, adding an option for accurate color reproduction to their capabilities. To do this, we present two different approaches. The first approach we call the Color Transformation Method. Here we use a Macbeth ColorChecker to first linearize the camera photometric response, and then find a linear matrix transformation from the camera response to CIEXYZ tristimulus values. The second approach we call the Illuminant Method. Here we consider each output by the camera as a reflectance factor value at the known wavelength of a narrowband illuminator. We then convert these values to the color of the object in terms of CIEXYZ tristimulus values. We show that the Color Transformation Method using a Macbeth ColorChecker leads to a more accurate result. Meanwhile, the Illuminant Method is much simpler and produces acceptable results, particularly considering accurate color reproduction was not a goal in designing the MISHA camera system. The same methods are applied to both imaging systems to show the robustness and applicability of the approaches developed herein to other imaging systems. Results are shown for both quantitative calibration targets as well as artifacts of interest to the field of cultural heritage studies. It is worth noting that we are not comparing the two imaging systems overall or the color processing software available from MegaVision. Rather, we simply show that the two approaches developed here are applicable to different multispectral imaging systems, from a very cost-effective system, i.e., MISHA to a more expensive one, i.e., MegaVision.

The Vice-Roy's Portraits Gallery hosted at the Old Goa Museum of the Archaeological Survey of India in Goa, India, is a unique panel painting collection, spanning from the 16th till the 18th centuries, and representing the Portuguese Viceroys and Governors who administrated the Portuguese provinces in the coastal region of the Indian Ocean. During the Old Goa Revelations project (a collaborative inter-institutional consortium between Evora University HERCULES Lab, Lisbon University Fine Arts Faculty, Archaeological Survey of India and Ghent University), this important collection of panel paintings was examined in-situ using a non-invasive approach with mobile analytical instrumentation. Next to a series of imaging techniques, point analysis has been performed, using both, elemental and molecular spectroscopic methods. On the one hand, handheld X-ray fluorescence analysis and macro X-ray fluorescence imaging was used to obtain the elemental composition and its distribution on pictorial support, while on the other hand mobile Raman spectroscopy was implemented to obtain molecular information. These non-invasive techniques were used to determine the composition of the paint layers and to study the different treatments (e.g. overpainting, changes in compositions, etc.) that the artworks have witnessed since their creation.