The development of new bio-friendly alternatives for wood conservation is of great interest and necessary for environmental protection. In this paper, the preparations based on the propolis extract and silicon compounds were used as green wood preservatives. The wood was treated with 15% propolis extract (EEP) and two propolis-silane preparations, namely, EEP-VTMOS/TEOS (EEP with vinyltrimethoxysilane and tetraethyl orthosilicate) and EEP-MPTMOS/TEOS (EEP with 3-(trimethoxysilyl) propyl methacrylate and tetraethyl orthosilicate). The aim of the research was to determine the properties of treated wood, which was characterized by Fourier transform infrared spectroscopy (FTIR), nuclear magnetic resonance (NMR), atomic absorption spectroscopy (AAS), X-ray fluorescence (XRF), and scanning electron microscopy (SEM). Moreover, the resistance against brown-rot fungus Coniophora puteana and the mechanical properties of treated wood were also determined. The analysis of phenolic compounds concentration in treated wood indicated that phenols were in greater extent leached from wood treated with the propolis extract than from wood impregnated with the propolis-silane preparations. The presence of silicon in treated wood both before and after leaching was confirmed by CP MAS NMR measurements. In turn, AAS and XRF analyses indicated that the degree of Si leaching from wood impregnated with EEP-VTMOS/TEOS was approximately two times lower than from EEP-MPTMOS/TEOS treated wood. The results of chemical analyses confirmed that the constituents of the propolis-silane preparations formed permanent bonds with wood. In turn, the results of the antifungal efficacy against C. puteana showed that the propolis extract and the propolis-silane preparations limited the fungus activity, even the wood was subjected to leaching procedure. The treated wood showed an increase in bending strength and a decrease in the modulus of elasticity compared to untreated wood. The obtained results indicate that the propolis-silane preparations can be promising green wood preservatives, harmless for the natural environment.
11 September 2019 in Archaeological and Anthropological Sciences
Iberian ‘warrior’ stelae have captured the imagination of researchers and the public for more than a century. Traditionally, stelae were considered ‘de-contextualised’ monuments, and research typically focused on the study of their iconography, paying little or no attention to their immediate contexts. As a result, despite the large number of these stelae known to date (c. 140) and the ample body of literature that has dealt with them, fundamental questions remain unanswered. This paper aims to demonstrate the potential of a multidisciplinary and contextual approach to push forward the research agenda on these monuments through a case study. Firstly, we introduce the Mirasiviene stela and the methods deployed for its investigation, which include a variety of digital imaging techniques, petrography, pXRF, intensive survey and multiscalar spatial analysis. Secondly, we discuss the results in relation to three main topics: stela biography, social practices and landscape context. Comparisons to the well-known nearby Bronze Age and Iron Age site of Setefilla are made throughout the discussion. Ultimately, this paper makes a case for the stelae of Mirasiviene and Setefilla being polyvalent monuments made by local artisans, that served both as landmarks and memorials in connection with dense late second and early first millennium BCE settlement patterns in the region. Probably linked to elites, ‘houses’ or kin groups of this time, stelae were set in symbolically charged places, liminal spaces nearby water, burials and pathways, attracting a range of ritual activities throughout the centuries. The study of the newly discovered Mirasiviene stela shows that multidisciplinary, cutting-edge non-destructive archaeology can shed significant new light on these prehistoric monuments, thus providing a glimpse of what in our opinion is a paradigm shift in the research of similar monuments throughout Europe.
Se presenta una amplia serie de nuevas determinaciones radiocarbónicas sobre hueso cremado, procedentes en su mayoría de las tumbas de los túmulos A y B de Setefilla, pero también de otros yacimientos del sur y oeste de la Península Ibérica. Se discute el potencial que aportan para resolver cuestiones de la cronología interna de la necrópolis y de su relación cronológica con el poblado de la Mesa de Setefilla, así como sus repercusiones generales sobre la cronología del Bronce Final y Hierro Antiguo en el Sudoeste peninsular.
Accelerated lakes eutrophication is one of the greatest challenges nowadays. To counteract its negative effects, large-scale restoration treatments are carried out worldwide. However, research in this field is mainly focused on the process effectiveness and there is a scarcity of studies concerning the impact of restoration treatments on water organisms and ecosystem homeostatsis. Our microcosm study presents the effects of a phosphorus coagulant (iron [III] chloride) on functional traits changes, oxidative stress and macro- and microelement stoichiometry disturbances in macrophyte Myriophyllum spicatum, a model species inhabiting eutrophic waters. Application of the coagulant to experimental vessels influenced the physicochemical and optical parameters of water and led to significant changes in biogeochemistry. Stoichiometric alterations were reflected by disturbances in the relative contents of macro- (C, N, P, Ca, Mg) and microelements (Fe, Zn, Cu, Co) and induced luxury consumption of available ions. Physicochemical and stoichiometric changes mutually exerted negative influence on M. spicatum functional traits. The parameters of oxidative stress remained at low levels, comparable to the untreated control whereas stoichiometric analysis revealed the activation of mechanisms responsible for minimizing low light stress. The ability of M. spicatum to maintain homeostasis of Cu and Co under simulated chemical water restoration was closely related to high concentrations of Fe and Zn ions, which simultaneously were not subjected to homeostasis control. Thus, chemical lake restoration treatments based on phosphorus coagulants are not as environmentally safe as previously considered and may have far-reaching consequences for the biogeochemical cycle and food web functioning.
This article presents studies on iron speciation in the pottery obtained from archaeological sites. The determination of iron forms Fe(II) and Fe(III) has been provided by a very simple test that is available for routine analysis involving the technique of molecular absorption spectrophotometry (UV–Vis) in the acid leachable fraction of pottery. The elemental composition of the acid leachable fraction has been determined by inductively coupled plasma optical emission spectrometry (ICP-OES). Additionally, the total concentration of the selected elements has been determined by X-ray fluorescence spectrometry with energy dispersion (EDXRF). The results of the iron forms’ determinations in archaeological pottery samples have been applied in the archaeometric studies on the potential recognition of the pottery production technology, definitely going beyond the traditional analysis of the pottery colour.