Heritage

The 3D model is the primary information of an integrated support system for the assessment of structural safety under vertical loads and seismic vulnerability of a masonry building. The available approaches for evaluating seismic demand and capacity still appear inadequate and today aims to improve the process of knowledge of the seismic behavior of masonry structures and of the reliability of the numerical analysis of evaluation methods. Discrete modeling approaches (macro-elements) can lead to more reliable results if accurate surveys of the geometry and construction details of the masonry structure are used, especially in contexts where advise against the execution of invasive on-site tests for assessments both under vertical and seismic loads, limiting the investigation campaigns. In order to improve digital processes, oriented to the knowledge of the state of health and quality of a masonry structure, this study illustrates a new overture to virtual modeling and assessment of the structural safety of this type of work. The survey and relief methodology here proposed integrates digital data sensors—configured within an IoT (Internet of Things) network—in a geometric model with a level of accurate and precise detail, processed downstream of the laser scanner and photogrammetric survey of the single masonry building, as “S. Domenico Church in the “Sassi” of Matera. Full article

Weld (Reseda luteola) was one of the main sources of yellow dyes used for dyeing textiles and to prepare artists’ pigments in Europe until the 19th century. For the first time, this work explores the technology of preparing weld lake pigments in the 19th century by Winsor & Newton (W&N), a renowned supplier of artists’ materials. Five recipes were discovered in the W&N 19th century Archive Database and reconstructed in the laboratory. W&N was extracting weld in neutral and basic media, and preparing the insoluble lake by complexation with Al³⁺ in the form of alum (KAl(SO₄)_2•12H₂O) or hydrated alumina (Al(OH)₃). Five yellow lake pigments were successfully obtained and characterized by High-Performance Liquid Chromatography-Diode Array Detector (HPLC-DAD) and Fourier Transform Infrared Spectroscopy (FTIR). Their chromatographic profiles display as main yellows, luteolin 7-O-glucoside (Lut-7-O-glu) or both Lut-7-O-glu plus luteolin 3′,7-O-glucoside (Lut-3’,7-O-glu). In two of the processes, the presence of gypsum (CaSO_4•2H₂O) was unequivocally detected by FTIR, being formed as a by-product. This work offers the first identification of weld lake pigments’ characteristic infrared bands. The W&N Database proved again to be a unique source of information on 19th-century artists’ materials and their commercial preparation. The knowledge gain is essential to ensure effective conservation and authentication procedures. Full article

The majority of architectural heritage consists of load-bearing masonry components made up of stone units and relatively weak mortar joints, yielding potential weak planes for masonry structures where tension and shear failures are expected to occur. Advanced nonlinear analyses are required to simulate these phenomena and predict the corresponding nonlinear structural behavior of historic masonry constructions. In this context, this paper presents a model of a stone masonry Roman aqueduct (the Valens Aqueduct), constructed in the fourth century A.D. in Istanbul, Turkey, to explore the seismic capacity and behavior using the discrete element method (DEM). The employed modeling approach comprises distinct rigid blocks interacting along their boundaries based on the point-contact hypothesis. Thus, the discontinuous stone skeleton of the masonry aqueduct is represented explicitly in the computational model. First, a validation study was conducted on the laboratory experiment to demonstrate the capabilities of the adopted modeling approach. Then, a discontinuum model representing the Valens Aqueduct was used to assess the seismic capacity of the structure under gradually increasing lateral forces. The numerical simulations gave insight into the structural response of the aqueduct from the elastic range to total collapse. Additionally, parametric research was performed considering joint properties, namely the joint tensile strength, contact stiffness, joint friction angle, and compressive strength of the masonry, to quantify the effects of contact parameters on the displacement response of the DEM model. Further inferences were made regarding the modeling parameters, and practical conclusions were derived. Full article

This paper proposes a combined methodology for the quantitative analysis of the correlations between the monitored influencing environmental factors and the water saturation induced deterioration of earthen relics in a humid area. The Archaeological Ruins of Liangzhu City that have been exposed and severely damaged in a humid environment with high water content and dry–wet cycles are chosen as examples. A monitoring system including atmospheric, groundwater, soil moisture conditions, and images of the surface was installed. Based on the proposed methodology, 11 key influencing indexes involving groundwater, soil moisture and temperature at different depths, atmospheric radiation, and rainfall for the water saturation induced deterioration are investigated, and their correlation is described by a regression model. The weight rankings of influencing factors to the deterioration of the research area are calculated. The results can help quantitatively control the atmospheric environment where the earthen relics are located and can promote the conservation of the archaeological ruins in the humid environment. Full article

At a time when climate change, conflicts, disasters, and other global crises and challenges are increasingly affecting World Heritage properties, the utility of conservation assessment standards must be rethought. This article proposes abandoning the assessment of authenticity to treat properties less as “things”, deemed authentic or not, and more as evolving “processes” that embrace continuity and compatible change, which, it is argued, helps meet the challenges of the twenty-first century, namely climate change mitigation and adaptation; building back better after conflicts, disasters, or pandemics; and, ultimately, achieving sustainable development goals. Drawing on policy analysis and a wide range of literature, the article explains why authenticity is not a useful concept and why the idea of “heritage as process” is more relevant to the contemporary world. It shows how this idea can be put into effect and linked to Outstanding Universal Value, integrity, protection and management, which are already requirements in UNESCO’s Operational Guidelines for the implementation of the World Heritage Convention. In doing so, it contributes to aligning the implementation of the Convention with that of the global agendas of our time. Full article

Extensive durability problems such as weathering and degradation are found in historic Scandinavian brick masonry buildings, especially from the neo-Gothic period. These are largely due to the crystallization of salts and frost action in the bricks and mortars. This article aims to show and illustrate which salts and crystals are found in historic brick masonry buildings and to describe their appearance and behavior. An additional aim is to explore possibilities of preventing salt-related damage on internal masonry wall surfaces, such as using hemp-lime sacrificial plaster beneath the plaster. The objective is to show the mechanisms behind salt-related problems and to perform a case study and a laboratory study on salt-damaged brick masonry containing sodium sulphate. In order to prevent and stop damage to the masonry, it is important to be able to identify the nature of the salt damage and the type of salt that caused the damage. Neo-Gothic brick masonry buildings require well-planned, continuous maintenance of the masonry. It is therefore of the utmost importance to have an understanding of the complex functions of the masonry and of the salts that can cause damage to these historic buildings. Full article

A physical process is characterized as complex when it is difficult to analyze and explain in a simple way, and even more difficult to predict. The complexity within an art painting is expected to be high, possibly comparable to that of nature. Herein, we apply a 2D stochastic methodology to images of both portrait photography and artistic portraits, the latter belonging to different genres of art, with the aim to better understand their variability in quantitative terms. To quantify the dependence structure and variability, we estimate the Hurst parameter, which is a common dependence metric for hydrometeorological processes. We also seek connections between the identified stochastic patterns and the desideratum that each art movement aimed to express. Results show remarkable stochastic similarities between portrait paintings, linked to philosophical, cultural and theological characteristics of each period. Full article

Interpretation and presentation is an essential component of the whole heritage conservation process. In response to the new opportunities and challenges arising from the changing perspectives on heritage conservation, the development of display technologies and the rise of cultural tourism, it becomes a challenging task for cultural heritage institutions to construct a systematic interpretation and presentation system of a cultural heritage site that can effectively communicate heritage significance and value to the public and provide visitors with positive and valuable experience. From four main aspects (site, technology, public, and education and research), this research provides a comprehensive overview of the implementation details of the interpretation and presentation system of Old Zuoying City, which is considered an unprecedented large-scale cultural heritage preservation plan in Taiwan, through participative site investigation and in-depth interviews, thereby providing a reference for the construction, implementation, and management of interpretation and presentation system at cultural heritage sites. Full article

Important features required for gels used for the cleaning of paintings are viscoelastic properties ensuring good adaptability to the morphology of the surfaces and complete gel removal after application. Poly (vinyl alcohol) (PVA)-borax gels containing different liquid phases are often used as cleaning materials, but still little is known about their ability to leave no residues. This study reports the development of an analytical method based on attenuated total reflectance–Fourier transform infrared (ATR-FTIR) spectroscopy and pyrolysis–gas chromatography/mass spectrometry (Py-GC/MS) for the identification of PVA-borax gel residues on mock-ups and on works of art after cleaning treatments. The effect of additives in the formulation (i.e., poly (ethylene oxide)) and of clearing treatments with organic solvents after the gel removal was assessed both with respect to the effectiveness of the cleaning and the presence of residues on the painted surfaces. The results obtained show that clearing the surfaces with cotton swabs and organic solvents after the application of the gel is necessary to ensure a good removal of gel residues. Moreover, Py-GC/MS analyses in single-ion-monitoring (SIM) mode are more sensitive and selective, allowing the detection of gel residues even on surfaces where no residue is detected by ATR-FTIR. Full article

This paper describes the public archaeology approach and placemaking experiment at the Etruscan and Roman site of Podere Cannicci in Tuscany (Italy), drawing from the previous experience at three other archaeological sites along the Tyrrhenian coast. After three years of excavations at the IMPERO Project (Interconnected Mobility of People and Economy along the River Ombrone), the team has begun a side project to develop new strategies for communicating the results of the research. These include, but are not limited to, an app which displays augmented reality and 3D reconstructions of both the site and the material culture. The project uses digital narratives to engage local communities and scholars in the interpretation and reconstruction of ancient landscapes along with the middle valley of the Ombrone river. This approach also has the potential to support and sustain local tourism, providing an original experience for visitors. Moreover, the solution allows people from all over the world to be connected with the ongoing research and its results, as everything will be published on a dedicated website. Full article

Slides de cavalete | Easel slides (1978–1979) is a slide-based artwork by the Portuguese artist Ângelo de Sousa (1938–2011), composed of one-hundred colour slides. Each image was produced by capturing different proportions of red, green, and blue (RGB) lights to obtain colour gradations. The artwork was first presented in the exhibition A Fotografia como Arte/A Arte como Fotografia | Photography as Art/Art as Photography in 1979. Associated with this exhibition, documentary evidence was found during the present study providing specific instruction on how to display the artwork (possibly unknown until now). According to that documentation, the artist wanted the work to be projected on a canvas mounted in an easel with a 19th century semblance, using a slide projector. In the last two exhibitions, carried out in 2017, after the artist had passed, the work was displayed as a digital projection, without the previously mentioned sculptural components. It was considered that this deviation from the first presentation could have led to a misunderstanding of the work. Thus, an exhibition of this artwork was prepared in a room at the Library of Faculdade de Ciências e Tecnologia. This was built as an experimental laboratory, having as one of its important objectives to test the variability of the work projected with a slide projector and a digital projector, following the display setup defined by the artist. For four days, the visitors were shown the work displayed under these two distinct scenarios of presentation. The visitors were also asked to fill out a questionnaire, to capture their perception about the variance of the work. The data obtained in the questionnaire and during the exhibition reinforced the decision to expose Slides de cavalete using the original technology. The public preferred the quality and beauty of the image using the slide projector, highlighting as positive aspects more granularity and warmer hue as well as higher depth of the images. Additionally, the production process behind Slides de cavalete was studied, based on documentation discovered in the artist’s archive and on reproductions, to enrich our perception of the work, in particular the complexity of creating the sfumato effects, and to understand the impact of changing the display technology. The results obtained made it possible to identify the main steps of making these slides, and this knowledge was shared with visitors in a workshop, integrated in this experimental laboratory. Full article

Alexandria and Istanbul, through diverse texts and writers, meet and intersect in their attempt to reconstruct and rebuild the metropolis’s character. Our method advocates spatiotemporal events in augmented literature that enable reflection of the palimpsest of historical frames. On a higher level, what we propose in this work is the dialogic field between the two metropolises, as it could be provided by novels’ chronotopes with the aid of augmented reality. We undertake a twofold task, to reveal the awareness of the connections between places and the connection and attachment of particular spaces, by unifying two approaches. First, Ecocriticism that comprises the ways in which novels express socio-cultural frameworks of the natural environment. The second approach is based on the strong interrelations of place engagement with collective and cultural memory. The linking of both urban, spatial geometry and topology with the waterscape for both metropolises, in our proposed conceptualization of a chronotope-based augmented continuum, endeavors to provide, firstly, the dialogic relations between the two metropolises, between each metropolis and the waterscape and, secondly, between urbanscape and waterscape and the novels’ fictional frameworks. Within the framework of the augmented reality, we synthesize the writers’ fictional cities with the factual surroundings of the metropolises in order to reconstruct the fragmented natural and architectural urban views in the continuity of the urban fabric, thus ending up proposing a dynamic repository of the metropolis landscape’s natural, collective and cultural memory. Full article

The Tuscany Masonry Database (TMDB) is an online database containing the results and the complete experimental data of in situ experimental tests carried out on masonry panels of masonry buildings located in the Tuscany Region (Italy), starting from 1990. The results can be freely downloaded by users after registration on the site. To date, the TMDB includes 142 georeferenced tests, comprising 50 diagonal tests, 5 compression tests, and 87 flat-jack tests. In addition, there are tests on the components, such as compression tests on blocks, penetrometric testing on mortar, macroscopic or microscopic analysis of mortar, and coring. The results are supported by a qualitative description of the masonry texture and are compared with the reference values of the mechanical characteristics proposed by the Italian Building Code. The data come from scientific literature and are the result of collaborations between the Seismic Sector of the Tuscany Region and some Tuscan University Laboratories, or they are shared by private test laboratories mainly acting in Tuscany. The TMDB was developed and is constantly updated by the authors to provide support to researchers and freelance engineers in the knowledge process phase of masonry buildings, as well as for that of particular structures, such as heritage buildings. Furthermore, it allows for the filling of the lack of particularity of masonry classification and for the consideration of particular masonry types existing in local areas, for which there are no literature data or specific experimentation. Further tests are currently being processed to be included in the database, and divulgation activity on the project is foreseen. Furthermore, national and international collaborations are underway for the expansion of the database, with the aim of unifying test procedures and updating the codes. Full article

Salt inhibitors have been receiving increasing attention as potential innovative systems to counteract salt damage by preventing crystallisation of the salts within the natural stone structure—and related disruptive action—of built heritage. Especially, we focus on biomass-derived inhibitor systems featuring complete solubility in water or alcohol and intrinsic non-toxicity. Moving from the promising results obtained, the present study aims to develop research concerning the possibility of rationalizing the collected data sets and making them amenable to statistical analysis. This paper reports on an exploratory application of one of the most powerful methods in chemometrics, i.e., principal component analysis (PCA), in this area. It will be seen that this method is a promising tool to extract information from a series of tests to optimize them and to reduce the level of “noise” present in the data collected, i.e., unnecessary information or experimental errors, and to suggest new directions. Full article

Granite geomorphological sceneries are important components of global geoheritage, but international awareness of their significance seems insufficient. Based on existing literature, ten distinctive types of relief are identified, along with several sub-types, and an overview of medium-size and minor landforms characteristic for granite terrains is provided. Collectively, they tell stories about landscape evolution and environmental changes over geological timescale, having also considerable aesthetic values in many cases. Nevertheless, representation of granite landscapes and landforms on the UNESCO World Heritage List and within the UNESCO Global Geopark network is relatively scarce and only a few properties have been awarded World Heritage status in recognition of their scientific value or unique scenery. Much more often, reasons for inscription resided elsewhere, in biodiversity or cultural heritage values, despite very high geomorphological significance. To facilitate future global comparative analysis a framework is proposed that can be used for this purpose. Full article

Light causes damage when it is absorbed by sensitive artwork, such as oil paintings. However, light is needed to initiate vision and display artwork. The dilemma between visibility and damage, coupled with the inverse relationship between color quality and energy efficiency, poses a challenge for curators, conservators, and lighting designers in identifying optimal light sources. Multi-primary LEDs can provide great flexibility in terms of color quality, damage reduction, and energy efficiency for artwork illumination. However, there are no established metrics that quantify the output variability or highlight the trade-offs between different metrics. Here, various metrics related to museum lighting (damage, the color quality of paintings, illuminance, luminous efficacy of radiation) are analyzed using a voxelated 3-D volume. The continuous data in each dimension of the 3-D volume are converted to discrete data by identifying a significant minimum value (unit voxel). Resulting discretized 3-D volumes display the trade-offs between selected measures. It is possible to quantify the volume of the graph by summing unique voxels, which enables comparison of the performance of different light sources. The proposed representation model can be used for individual pigments or paintings with numerous pigments. The proposed method can be the foundation of a damage appearance model (DAM). Full article

The production and use of the pigment extracted from the murex molluscs is discussed here in association with the purple textile dyeing industry in the Prehistoric Aegean. “True” purple has been identified in a number of archaeological finds dating from the early Late Bronze Age, found in old and recent excavations at three different but contemporary sites: Akrotiri and Raos on Thera, and Trianda on Rhodes. The chemical composition of the shellfish purple pigment either found in lump form or applied on wall paintings is discussed in relation to the archaeological context of several examined finds and with reference to Pliny’s purpurissum. The results of a comprehensive methodology combining new data obtained with molecular spectroscopies (microRaman and FTIR) and already reported data obtained with high performance liquid chromatography coupled with a diode array detector (HPLC–DAD) applied to samples of the murex purple finds are discussed in comparison to published data relating to few other instances of analytically proven murex purple pigment found in the Aegean over the timespan of its documented exploitation. Full article

Aesthetic properties of natural heritage objects are determined by their physical properties. Online promotion of these objects to potential tourists requires adequate representation of these properties on web pages. The Shum waterfall is a small, but notable and tourism-important geosite of southwestern Russia. Its real aesthetic properties were examined in the field, and 20 web pages devoted to local tourism were examined to judge its promoted aesthetic properties. Eleven criteria of the common tourists’ judgments of beauty were used for this purpose. A significant discrepancy between the real and promoted properties is found. Particularly, the web pages exaggerate the scale of the waterfall and do not mention crowds of tourists. This may cause disappointment of the latter. The findings of the present study allow for making several practical recommendations for more efficient promotion of the Shum waterfall, as well as providing general advice to the geotourism industry. Full article