THE ROLE OF TECHNICAL AND NATURAL SCIENCES IN STONE MONUMENTS CARE

Stone monuments maintenance requires the systematic approach which should be based on the cooperation among specialist through more branches, especially from humanities, natural and technical sciences. The main aim of this article is to present the benefit of the cooperation among geologists and civil engineers and share preliminary results of the Czech Ministry of Culture project DG20P02OVV021 “Stone surface topography and its application in stone element restoration field”. Historic stone surfaces often contain stonemasons tool traces as an undoubtable part of historical monument value. The study and protection of the testimony of past is therefore very important. As a part of our project, we are conducting field and laboratory research of historic stone surfaces bearing the original tool traces. The studied area is the Prague urban conservation zone for its stone monuments richness from Romanesque to present days. First, the geological research of the stone masonry surface is conducted in the cooperation with archaeologists. The tool traces are documented, and the state of stone is described. Because of the negative influence of weathering processes on the stone durability, respectively tool traces, we decided to monitor the chosen historical stone surface using the hyperspectral analysis. Based on the analysis results we will be able to better understand the behaviour of stone surface and traces on it during the time.

The Middle Holocene ‘funerary avenues’ of north-west Arabia

The desert regions of the Arabian Peninsula and Levant are criss-crossed by innumerable pathways. Across large areas of north-west Arabia, many of these pathways are flanked by stone monuments, the vast majority of which are ancient tombs. Recent radiometric dating indicates that the most abundant of these monuments, elaborate and morphologically diverse ‘pendant’ structures, were constructed during the mid-to-late third millennium BCE. Thousands of kilometres of these composite path and monument features, ‘funerary avenues’, can be traced across the landscape, especially around and between major perennial water sources. By evidencing routes of human movement during this period, these features provide an emerging source for reconstructing important aspects of ancient mobility and social and economic connectivity. They also provide significant new evidence for human/environment interactions and subsistence strategies during the later Middle Holocene of north-west Arabia, and suggest the parallel existence of mobile pastoralist lifeways and more permanent, oasis-centred settlement. This paper draws upon the results of recent excavations and intensive remote sensing, aerial and ground surveys in Saudi Arabia to present the first detailed examination of these features and the vast cultural landscape that they constitute.

Perspective of Materiality in Archaeological Heritage

In the wider professional community gathered around the notion of archaeological heritage, there is an undisputed consensus that the material traces have to be preserved for research, education and presentation, for the present and future generations. However, the climate change, pollution, intensive urbanization and other perils present a significant source of risk for archaeological remains in their original settings. Additionally, archaeological evidence may be present in the form of skeletal remains, cave drawings, landscapes or negatives of missing objects or materials. Underwater finds, stone monuments, archaeobotanical traces, fortifications, or wooden sanctuaries may all also constitute archaeological remains. In order to be preserved today, each of these examples requires various conditions, processing of material traces and preservation after excavation. Finally, all these artefacts and ecofacts gain different places in the contemporary context. Bearing in mind the variety of situations and forms in which archaeological finds and material remains may occur, it is necessary to reconsider the scope of the content embraced by the term of archaeological heritage and material traces of the past, under the conditions of rapid and intensive changes. Here the theoretical standpoint is applied derived from Bruno Latour, about the role of various actants, live and non-live participants in social processes. In this sense, objects – artefacts and ecofacts, are parts of diverse processes of negotiation and reshaping of their environment. They can equally influence, entice, stop or change processes. In order to contribute to solving this dilemma, the text discusses the notion of archaeological materialities at the intersection of conservation and archaeological perspectives. It is argued that, when facing the current problems, especially in regard to in situ preservation, the answers and inspiration should be sought for in the wider conceptualization of materiality, as the guide and source of specific knowledges, leading to new theoretical insights.

Assessment of Stone Protective Coatings with a Novel Eco-Friendly Encapsulated Biocide

The conservation of stone monuments is a constant concern due to their continuous weathering, in which biofouling plays a relevant role. To enhance the effectiveness of biocidal treatments and to avoid environmental issues related to their possible toxicity, this research aims at formulating and characterizing a coating charged with an eco-friendly biocide and showing hydrophobic properties. For this purpose, zosteric sodium salt—a natural biocide product—has been encapsulated into two silica nanocontainers and dispersed into a tetraethoxysilane-based (TEOS) coating also containing TiO2 nanoparticles. The coatings were applied on four different types of stone: brick, mortar, travertine, and Carrara marble. The effectiveness of the coating formulations and their compatibility concerning the properties of coated stones were assessed. The results showed that all coatings conferred a hydrophobic character to the substrate, as demonstrated by the increase of the static contact angle and the reduction in the capillary water absorption coefficient. The transmission of water vapor of the natural stones was preserved as well as their natural aspect. Furthermore, the coatings were homogeneously distributed on the surface and crack-free. Therefore, the protective capability of the coatings was successfully demonstrated.

SCULPTURAL TRADITIONALISM AND INNOVATION IN THE CLASSIC MAYA KINGDOM OF SAK TZ'I', MEXICO

In this article we analyze the content and form of 58 stone monuments at the archaeological site of Lacanjá Tzeltal, Chiapas, Mexico, which recent research confirms was a capital of the Classic Maya polity Sak Tz'i' (“White Dog”). Sak Tz'i' kings carried the title ajaw (“lord”) rather than the epithet k'uhul ajaw (“holy lord”) claimed by regional powers, implying that Sak Tz'i' was a lesser kingdom in terms of political authority. Lacanjá Tzeltal's corpus of sculptured stone, however, is explicitly divergent and indicates the community's marked cultural autonomy from other western Maya kingdoms. The sculptures demonstrate similarities with their neighbors in terms of form and iconographic and hieroglyphic content, underscoring Lacanjá Tzeltal artisans’ participation in the region's broader culture of monumental production. Nevertheless, sculptural experimentations demonstrate not only that lesser courts like Lacanjá Tzeltal were centers of innovation, but that the lords of Sak Tz'i' may have fostered such cultural distinction to underscore their independent political character. This study has broader implications for understanding interactions between major and secondary polities, artistic innovation, and the development of community identity in the Classic Maya world.

APPLICATION OF SURVEYING AND MAPPING TECHNOLOGY IN DISEASE EXTRACTION AND ANALYSIS OF STONE MONUMENTS

With thousands of years of glorious history and culture, China, which is the origin of Chinese civilization has also survived with a magnificent amount of stone cultural heritage. Stone monuments are one of the most important components of Chinese monuments and contain a wealth of historical information by themselves. Due to the fact that some stone monuments and stone architectural elements are often exposed to the natural environment, they are subject to physical, biological, chemical and human damage over a long period of time, which leads to the formation of various kinds of damages. Therefore, it is an important issue to extract and analysis the diseases information effectively. In this paper, we were going to examine these issues in the context of existing surveying and mapping techniques.

The Efficiency of Biocidal Silica Nanosystems for the Conservation of Stone Monuments: Comparative In Vitro Tests against Epilithic Green Algae

In the last decade, worldwide research has focused on innovative natural biocides and the development of organic and inorganic nanomaterials for long-lasting reliability. In this work, the biocide effects of two different biocides encapsulated in two different silica nanosystems for a multifunctional coating have been performed through in vitro tests, by using Chlorococcum sp. as a common stone biodeteriogen. Zosteric sodium salt (ZS), a green biocide, was compared with the commercial biocide, 2-mercaptobenzothiazole (MBT), widely used in the treatment of cultural heritage. The analyzed systems are the following: silica nanocapsules (NC) and silica nanoparticles (MNP) not loaded with biocides, two nanosystems loaded with ZS and MBT, and free biocides. The qualitative and quantitative evaluations of biocide efficiency were performed periodically, analyzing pigment autofluorescence to discriminate between active and inactive/dead cells. The analyses showed multiple differences. All the nanocontainers presented an initial reduction in chlorophyll’s autofluorescence. For the free biocide, the results highlighted higher efficiency for MBT than ZS. Finally, the nanosystems loaded with the different biocides highlighted a higher activity for nanocontainers loaded with the commercial biocide than the green product, and better efficiency for MNP in comparison with NC.