Effectiveness and Compatibility of Nanoparticle Based Multifunctional Coatings on Natural and Man-Made Stones

The interaction of microorganisms with stone materials leads to biodeterioration processes, which may cause aesthetic damages and the loss of durability and strength of the substrates. Innovative solutions against this process are represented by nanotechnologies. In our previous works, 2-mercaptobenzothiazole was successfully encapsulated within two silica-based nanodevices: nanocapsules and mesoporous nanoparticles. Such loaded nanodevices have been dispersed in TEOS based coatings, characterized as far as their chemical–physical properties and in vitro biocide efficacy. Here, we adopt a multi-technic approach, to assess the coatings efficacy and compatibility with four types of stones of cultural heritage interest, namely, mortar, brick, travertine, and Carrara marble. In particular, we determine the protective function of the coatings, based on water transport properties (reduction up to a factor 10 of the water absorption for brick and mortar, without significantly influencing water vapor transmission rate), morphology of the surface (absence of coating cracks and color changes), and TiO2 photocatalytic activity. Consequently, these coatings can be considered suitable for application on stone artifacts, without interfering with their artistic appearance.

Stone Industry of Somchai Cave (Excavations of 1980–1981)

Purpose. This article is dedicated to the collection of stone tools obtained as a result of excavations of the Somchai cave (North Vietnam) in 1980–1981. Somchai cave was discovered as a cultural object in 1980 and was investigated by various Vietnamese archaeologists in 1980–1981. The Somchai stone industry was attributed by Vietnamese researchers to the cultural and chronological stages of Hoabin II (Mezolithic) and Hoabin III (Early Neolithic). At the same time, the stratigraphic sequence of the lithological divisions of the site raises questions, due not only to the fragmentation of information in published sources, but also the influence of the modern anthropological factor. The description of archaeological material was selectively compiled, and subsequent publications were devoted to general reviews and paleobotany. Results. Somchai Cave belongs to the Karst region of the Kimboy massif of the northern part of the Annam Highlands (Chyongshonbak). The object is located at an altitude of 85 m above u.m. in the limestone remains in the Muongwang Valley of the Buoy River. It was discovered as a cultural site in 1980 and was investigated by various Vietnamese archaeologists in 1980–1981, 1982 and 1986. The stone industry of the Somchai site contains 845 artifacts. Among tools, the multiple group is represented by sumatralita, further on the frequency of occurrence the adzes, polished axes, choppers stand out, scraped, scrapers and other single products. Conclusion. By relying on a technical and typological analysis of a collection of stone artifacts obtained during research in 1980–1981, the Somchai cave industry can be defined as pebble and flake. It demonstrates the already developed features of stone technologies and tools, which are more distinctive for later cultures, such as Bakshon and Dabut, but at the same time the splitting traditions characteristic of the Paleolithic of Vietnam, which, like the Paleolithic of all Southeast Asia, continued the pebble-cleaved tradition, are preserved.

A Macroscopic Perspective on Lithic Technology and Human Behavior during Pleistocene in Zhejiang Province, Southeastern China

Paleolithic archeological remains were not reported from Zhejiang until 2002. Up to now, over 70 Paleolithic sites and/or localities have been recovered through a series of surveys mainly in the north part of Zhejiang. An overview of the Paleolithic record and archeological sequence in this region during the Early to Late Pleistocene are present from a macroscopic perspective in this article, as well as the brief introduction of lithic technology and human adaptation in south China. In general, the lithic assemblages in Zhejiang represent the features of Pebble Industry in south China and show a trend of reduction on the size of stone artifacts since the Late Paleolithic. It is presumed that prehistoric humankind has shown the behavioral strategies as followed: a) exploited local raw material; b) the utilization of core and the degree of proficiency in knapping have been improved gradually; c) the retouching focused on the areas of edges; and d) preferred to use sharp edges of tools.

Robberg Material Procurement and Transport in the Doring River Catchment: Evidence from the Open-Air Locality of Uitspankraal 9, Western Cape, South Africa

Decisions related to the production of lithic technology involve landscape-scale patterns of resource acquisition and transport that are not observable in assemblages from any one single site. In this study, we describe the stone artifacts from a discrete cluster of stone artifacts assigned to the Robberg technocomplex (22-16 ka) at the open-air locality of Uitspankraal 9 (UPK9), which is located near two major sources of toolstone in the Doring River catchment of Western Cape, South Africa. OSL dating of the underlying sediment unit provides a terminus post quem age of 27.5 ± 2.1 ka for the assemblage. Comparison of near-source artifact reduction at UPK9 with data from three rock shelter assemblages within the Doring watershed – Putslaagte 8 (PL8), Klipfonteinrand Rock Shelter (KFR), and Mertenhof Rock Shelter (MRS) – suggests that “gearing-up” with cores and blanks occurred along the river in anticipation of transport into the wider catchment area. The results reveal an integrated system of technological supply in which raw materials from different sources were acquired, reduced, and transported in different ways throughout the Doring River region.