Journal of Cultural Heritage最新文献

Mineral pigment provenance is a promising direction in cultural heritage particularly in ancient polychromy research. The analysis of trace elements and Pb-isotopes can provide clues about the origin of pigment raw materials. While previous investigations already showed great potential for provenancing archeological-historical mineral pigments, sampling methods and reference data collections need to be developed further to evaluate the potential and limitations of this type of research. This work tests a new sampling method for pigment provenance research that collects sample material with easily available (suffused) cotton swabs for analysis by mass spectrometry. Three artifacts decorated with Egyptian blue and red pigments were selected for comparing sampling with cotton swabs to sampling with a scalpel. All three artifacts date to the 1st century BCE: The first is a colossal marble head from Lazio, Italy, which probably belonged to a seated cult statue of Zeus, and with extensive remains of ancient red paint. The two artifacts (a slag and a fragment of a terracotta vessel) were recovered during Petrie's excavations of an Egyptian blue production facility in Memphis, Egypt. The new results are consistent with previous studies, which provides the necessary quality control for the cotton swab sampling method. This work contributes to improving sampling methods for pigment provenance analysis as well as to a better understanding of past pigment production and trade networks.

Siloxane oligomers produced through the hydrolysis of tri-alkoxysilanes or tetra-alkoxysilanes have been widely used as consolidants for stone heritage. However, the resulting xerogels tend to crack due to the volume shrinkage after curing. In this study, a novel flexible-rigid hybrid siloxane oligomer material is designed by the self-catalyzed copolymerization of di-alkoxysilane (3-Aminopropyl) dimethoxymethylsilane with tetra-alkoxysilane tetraethyl orthosilicate. The flexible linear SiOSi segments produced by di-alkoxysilane are inserted into the tetra-alkoxysilane derived rigid three-dimensional silicon-oxygen domains, as confirmed by spectroscopic characterizations. This unique structure alleviates the shrinkage stress during curing and enables the formation of crack-free xerogels. Therefore, the hybrid siloxane oligomer can invade into the interior of weathered stone to form one three-dimensional continuous network to strengthen its fragile structure. As a result, the flexible-rigid hybrid siloxane oligomer outperforms both as-made polysiloxane consolidant and commercial consolidant for the consolidation of the weathered Tianlong Mountain Grottoes stone samples. The consolidation treatment was evaluated in terms of effectiveness (Leeb hardness, ultrasonic velocity and compressive strength) and compatibility (pore size distribution, water vapor transmission rate and color variation). Following the treatment, the consolidated samples demonstrate remarkable improvements in mechanical properties, reaching a Leeb hardness of 410 HL and a compressive strength of 8.98 Mpa. Additionally, permeability and color variation of the stone after consolidation are all within acceptable ranges. The results confirm the positive consolidation performance of the flexible-rigid hybrid siloxane oligomer on weathered Tianlong Mountain Grottoes stone, indicating promising practical applications.

The progression in the use of nanostructured metal oxide or metal oxide based polymeric nanocomposite for the conservation and refurbishment of cultural heritage are presented in this review. Starting from the definition of nanoparticles, their major synthesis techniques, the paper briefly describes the utilization of various metal oxide nanoparticles and metal oxide based polymeric nanocomposite coatings and their surface protection functions including self-cleaning, increased photocatalytic activity, biocidal effects, UV blocking properties and compatibility with the different types of substrates including wood, stones, bricks and paper focussing on their potential usage and their application in the arena of remediation of cultural heritage.

The deterioration of leather artifacts can be caused by exposure to light, pollutants, microbes, and oxidation. In this work, silver-titanium dioxide nanoparticles (Ag-TiO₂ NPs) were synthesized using chestnut extract as both a template and a reducing agent, providing UV light shielding, self-cleaning capacity, antibacterial activity, and antioxidant capacity. The results indicated that the addition of chestnut extract and Ag significantly enhanced the UV light shielding capability of Ag-TiO₂ NPs by enhancing the light absorption efficiency, as well as reduced the band gap from 3.20 eV to 2.82 eV, and improved the self-cleaning capability as evidenced by an increase in Congo red (CR) dye degradation rate from 26 % to 55 %. Additionally, Ag-TiO₂ NPs also exhibited remarkable antibacterial activity, as evidenced by a significant increase in the inhibition zone against bacteria, as well as enhanced antioxidant capability with the DPPH free radical scavenging capability increased from 22 % to 88 %. After Ag-TiO₂ NPs treatment, there was no obvious change in the appearance of leather, while the antibacterial activity of leather was significantly increased. The Ag-TiO₂ NPs produced through a green approach could offer robust UV light shielding, self-cleaning capacity, antibacterial activity, and antioxidant capacity to prevent the deterioration of leather artifacts, making a significant contribution to the long-term preservation of cultural heritage.

This paper aims is to show an automated intelligent measurement system for the detection of adhesion defects between architectural antique plaster layers. The method emulates the traditional conservators’ procedure based on acoustical perturbations, auscultation, detection and classification. The system makes use of a hardware device, known in literature as PICUS, for the generation and acquisition of acoustic signals, while the processing of the acquired signals is handled by a deep learning (DL) architecture designed ad hoc. After a brief description of the PICUS system and the acoustic data acquisition procedure, the whole architecture of the DL system is carefully described. The proposed method has been validated by a significant case study. The system shows an accuracy of up to 82% ($\pm$ 2%) in multi-class classification and up to 99% ($\pm$ 1%) in binary classification. In particular, the obtained results suggest a satisfactory precision in the detection of areas where stabilization is necessary.

By developing new recording methodologies, current rock art studies generate a large amount of graphic information about sites (tracings, photographs, three-dimensional reproductions) providing visibility of this fragile and little-known heritage, whose accessibility is often difficult or impossible for the general public. In addition, many rock art depictions are challenging to observe, due to the very nature of the artistic entities (fine engravings or faded paintings in karst environments or open-air sites with poor or changing light conditions), or to conservation problems derived from natural factors such as erosion and geological and biological processes, as well as from anthropic factors. These conditions make rock art depictions nearly indistinguishable in many places and on many objects today, except for experts. This difficulty of accessing and visualising rock art heritage, located in fragile environments and often challenging places such as caves or difficult-to-reach open-air sites, makes the information and knowledge generated by investigation of this heritage asset difficult to transfer to society in general, which is frequently unaware of the priceless value of this heritage. The present study proposes generating several mechanisms to transfer the results of research, restitution and documentation of rock art to society in general. An AR (Augmented Reality) application has been developed using LiDAR (Light Detection and Ranging) technology to address current challenges in implementing AR technologies in low-light environments. So far, this app has been developed in a Proof-of-Concept project at Spanish archaeological sites such as Hornos de la Peña (Cantabria), Domingo García (Segovia) and La Salud (Salamanca). This application will be particularly interesting for sites currently visited with or without a guide, allowing user interactivity and real-time reconstruction, for example, of the visibility of graphic motifs.

Deterioration investigation is an essential foundation for understanding the preservation status of stone cultural heritage, as well as for carrying out emergency and preventive conservation. Traditional photogrammetry method for deterioration investigation in stone cultural heritage heavily relies on personnel experience and has low automation. To accurately evaluate the degree of deterioration and quantify its scale, different algorithms are used to establish the rebound value prediction model and deterioration identification model based on the hyperspectral image. The effects of different wavelength selection methods and different classification models are compared. The results show that the rebound value inversion model constructed by CARS and PLS delivers the most accurate forecasts, with R² being no less than 0.85. The maximum error of the model when applied in the field does not exceed 20%. Different types of deterioration can be initially identified by the normalized spectral index constructed from the 530 nm and 675 nm wavelengths. In addition, all four classification models based on hyperspectral imaging texture features can identify different types of deterioration. The LGBM model has the highest identification accuracy of 0.98. It also has good performance in field identification. This study provides a new method for deterioration investigation in stone cultural heritage.

Jens Juel (1745–1802) was a prominent Danish portrait painter, mainly known for creating over 600 portraits during his prolific four-decade career. This study investigated 22 canvas paintings by the artist, the majority of which are well preserved despite displaying typical signs of ageing like cracking. Crack formation in paintings results from a combination of external factors, such as environmental conditions, and inherent properties, including the composition of painting materials. Different materials used in the layers of a painting contribute to distinctive crack patterns, and this work focused on understanding how the composition of the ground layer and the density of the canvas influence these patterns. By employing a multi-analytical approach involving imaging, elemental and molecular analysis, along with data-driven methods such as dimensionality reduction, cluster analysis and statistical tests, the research established relationships between crack patterns and ground layer compositions in Juel's paintings. The findings unveiled significant physical and chemical differences between artworks created in Denmark (and partly Germany) and those from France and Switzerland, which can be attributed to different canvas preparation traditions. Crack patterns in Danish paintings are primarily characterised by orthogonal patterns with jagged lines, and these artworks have ground layers rich in calcium carbonate with minimal lead white and denser canvases. In contrast, French and Swiss paintings exhibit diagonal cracks in larger islands, and predominantly contain lead white with little to no presence of calcium carbonate in their ground layers. By integrating visual and chemical data, the investigation revealed four distinct crack pattern groups aligned with four ground types, underscoring the resilience of lead white-rich grounds, which are likely to be less susceptible to canvas-induced cracking compared to calcium-based grounds. Hence, the research uncovered a correlation between the proportion of these two components in the ground and the observed variations in crack patterns across different geographical and temporal contexts. These insights are crucial for conservators aiming to preserve not only Juel's artworks but also those of his contemporaries. The study highlights the significance of linking material choices to natural ageing patterns, and emphasises the importance of material analysis in predicting responses to ambient conditions and guiding conservation strategies for long-term stability of paintings.

The archaeological amber artefacts from various periods in China provide valuable insights into ancient international trade and cultural interactions. This study investigated several archaeological amber artefacts (Arc 1–6) from the collection of the Hunan Museum, originating from different historical periods. The examination of the ageing characteristics of the cross-section and weathered surface was carried out using scanning electron microscopy (SEM), Fourier Transform Infrared (FTIR) spectroscopy and Pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) to analyse the functional groups and chemical compositions. FTIR spectroscopy proved limited information in determining the origin due to natural ageing causing alterations in peak shape/position or signal noise. Py-GC/MS analysis identified the amber artefacts as succinite and revealed that a set of compounds can serve as markers for identifying the origin. The pyrogram patterns classified the samples into two groups based on the marker content. Py-GC/MS results indicated that hydrolysis is an inevitable degradation process during the burial of succinite. Additionally, amber went slow oxidation in low-oxygen environments, leading to cyclization and the formation of polycyclic structures. This research highlights the ageing characteristics of amber artefacts and demonstrates that Py-GC/MS is an effective way in determining the provenance of significantly degraded samples, providing clues to ancient trade routes and cultural exchanges via the Silk Road.

The biodeterioration of cultural heritage objects is often attributed to microscopic fungi and their metabolic activity. These fungi often produce pigments that result in aesthetic alterations. Furthermore, through physical mechanisms like hyphal penetration and chemical mechanisms such as the production of acids or other harmful substances, they can degrade the integrity and structure of a wide range of materials. It is therefore necessary to identify these microorganisms as an initial step towards preserving cultural heritage objects for future generations. This study aims to identify the fungi present on audio-visual materials stored in two Czech Republic archives. Employing both a culture-dependent approach, using four different cultivation media, and a culture-independent approach with Illumina MiSeq sequencing, comprehensive fungal identification was conducted. The culture-dependent method yielded the identification of only 11 isolates from 7 genera, highlighting the necessity to enhance fungal capture efficiency, with the MEA medium proving the least suitable. In contrast, 75 genera were identified by the culture-independent approach. However, minimal overlap in results between the approaches, with only the Aspergillus and Bjerkandera genera in common, emphasises the significance of employing both methods. Next, analysis in two different archives suggested a potential association of 16 genera directly with audio-visual materials rather than storage conditions, including the genera Filobasidium, Naganishia, Sporobolomyces, or Wallemia. Furthermore, factors influencing the composition of fungal communities on audio-visual materials were investigated, of which locality proved to be statistically significant.