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This research aimed to characterise pigments used to decorate a polychrome earthenware bas-relief of the 15th century entitled "Madonna with Child, Saint Catherine of Siena, and a Carthusian Prior", attributed to Giovanni Antonio Amadeo (Pavia, 1447–Milan, 1522) and owned by the Sforzesco Castle Museum of Milan. The artwork underwent a cleaning procedure whose aims were the removal of the dark coating that obscured its surface and restoration work that could bring back its original features. Before the cleaning, six microsamples were collected and analysed using optical microscopy (OM), scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy (SEM-EDXS), and Fourier-transform infrared microspectroscopy in ATR mode (ATR-FTIR), providing the restorers with decisive information on the materials underlying the coating. After the cleaning, the terracotta appeared vibrantly coloured, mainly with bright red, blue, green, black, and white tones. Then, some in situ, non-destructive, spectroscopic measurements were performed by a portable Raman spectrometer on some of the areas that could not otherwise have been sampled. The analyses revealed the presence of natural pigments, including lead white, azurite, yellow ochre, carbon black, calcite, cinnabar, and gypsum. For Madonna's mantle, cobalt and Prussian blue were employed. Furthermore, the presence of barium sulphate was widely evidenced on the bas-relief. Albeit cobalt blue is of synthetic origin, its presence is compatible with the 15th-century palette, whereas Prussian blue and barium sulphate could be imputed to a previous restoration. Finally, the use of true gold for the background of the earthenware attests to the artwork's importance and value. [ABSTRACT FROM AUTHOR]

This work is concerned with a multi-analytical identification of the colour palette utilised in the decoration of the cover of an Egyptian sarcophagus dated to the Late Dynastic Period and belonging to a private collection. In this study, six different points were analysed with a portable Raman spectrometer; then, in these same points, six micro-fragments were taken from the sarcophagus for laboratory analysis performed by scanning electron microscopy coupled with energy dispersive X-ray spectroscopy (SEM-EDXS), attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR) and visible induced luminescence imaging (VIL). Raman spectra collected in situ showed the characteristic bands of calcite, red ochre and black carbon. SEM-EDXS analyses highlighted the presence of a copper-based pigment in the light blue, blue and black fragments; then, the ATR-FTIR spectrum of the light blue sample only displayed the peculiar bands of Egyptian blue. The latter result was confirmed by VIL analysis, which successfully identified the same pigment in blue-black fragments as well, leading to the possible authentication of the finding. Moreover, the presence of calcite, red ochre, green earth and some organic material was assessed by FTIR spectroscopy, confirming some of the results of in situ Raman analyses. Regarding organic materials, whose investigation is still ongoing, some hypotheses were made on the basis of their FTIR spectra. [ABSTRACT FROM AUTHOR]

Six rare porcelains of the Qing Dynasty, in particular, dishes ordered respectively for Philibert Orry, the Duke of Penthièvre and a tureen from the service of Louis XV, with royal coat-of-arms, were analyzed non-invasively by Raman microspectrometry. A coffee pot with a rare decoration attributed to Cornelius Pronk was also analyzed as well as two plates, one decorated with an Imari-style pattern and the second post-decorated in the Low-Countries/Holland. The enamel types and coloring or opacifying agents were identified on the basis of combined Raman and SEM-EDXS analysis previously published as well as new section and surface analysis of five plate samples representative of different technologies (blue-and-white, Famille rose). The use of lead oxide for the preparation of overglaze is demonstrated. For the first time, the use of borax in the blue overglaze according to the recipe from the 1753 manuscripts of French chemist Jean Hellot is demonstrated on Chinese porcelain. This fact, like the use of cobalt free of manganese, demonstrates the use of European ingredients and/or recipes for ceramics exported from China to Europe. The highlighting of the use of different recipes or raw materials for porcelain from the same period can therefore be the signature of different workshops. For instance, three different Raman signatures of red decoration were identified from the hematite vibration modes: very narrow modes for Pronk’ coffee pot and Louis XV tureen, broad for Orry’ dish and intermediate for the others. Three workshops are thus expected. It is interesting to note that the use of arsenic for the realization of white enamels corresponds to the latest objects, made after 1738. China was therefore in the 18th century both an importer of European know-how, design and an exporter of enameled products made with imported technologies to Europe.

Six rare porcelains of the Qing Dynasty, in particular, dishes ordered respectively for Philibert Orry, the Duke of Penthièvre and a tureen from the service of Louis XV, with royal coat-of-arms, were analyzed non-invasively by Raman microspectrometry. A coffee pot with a rare decoration attributed to Cornelius Pronk was also analyzed as well as two plates, one decorated with an Imari-style pattern and the second post-decorated in the Low-Countries/Holland. The enamel types and coloring or opacifying agents were identified on the basis of combined Raman and SEM-EDXS analysis previously published as well as new section and surface analysis of five plate samples representative of different technologies (blue-and-white, Famille rose). The use of lead oxide for the preparation of overglaze is demonstrated. For the first time, the use of borax in the blue overglaze according to the recipe from the 1753 manuscripts of French chemist Jean Hellot is demonstrated on Chinese porcelain. This fact, like the use of cobalt free of manganese, demonstrates the use of European ingredients and/or recipes for ceramics exported from China to Europe. The highlighting of the use of different recipes or raw materials for porcelain from the same period can therefore be the signature of different workshops. For instance, three different Raman signatures of red decoration were identified from the hematite vibration modes: very narrow modes for Pronk' coffee pot and Louis XV tureen, broad for Orry' dish and intermediate for the others. Three workshops are thus expected. It is interesting to note that the use of arsenic for the realization of white enamels corresponds to the latest objects, made after 1738. China was therefore in the 18th century both an importer of European know-how, design and an exporter of enameled products made with imported technologies to Europe. [ABSTRACT FROM AUTHOR]

This research aimed to characterise pigments used to decorate a polychrome earthenware bas-relief of the 15th century entitled “Madonna with Child, Saint Catherine of Siena, and a Carthusian Prior”, attributed to Giovanni Antonio Amadeo (Pavia, 1447–Milan, 1522) and owned by the Sforzesco Castle Museum of Milan. The artwork underwent a cleaning procedure whose aims were the removal of the dark coating that obscured its surface and restoration work that could bring back its original features. Before the cleaning, six microsamples were collected and analysed using optical microscopy (OM), scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy (SEM-EDXS), and Fourier-transform infrared microspectroscopy in ATR mode (ATR-FTIR), providing the restorers with decisive information on the materials underlying the coating. After the cleaning, the terracotta appeared vibrantly coloured, mainly with bright red, blue, green, black, and white tones. Then, some in situ, non-destructive, spectroscopic measurements were performed by a portable Raman spectrometer on some of the areas that could not otherwise have been sampled. The analyses revealed the presence of natural pigments, including lead white, azurite, yellow ochre, carbon black, calcite, cinnabar, and gypsum. For Madonna’s mantle, cobalt and Prussian blue were employed. Furthermore, the presence of barium sulphate was widely evidenced on the bas-relief. Albeit cobalt blue is of synthetic origin, its presence is compatible with the 15th-century palette, whereas Prussian blue and barium sulphate could be imputed to a previous restoration. Finally, the use of true gold for the background of the earthenware attests to the artwork’s importance and value.

This article explores the materials and techniques of gilding in the Serbian wall painting of the 13th and early 14th centuries. The investigation focuses on the pictorial decoration of the churches at Studenica, Mileševa, Sopoćani, Gradac and Banjska, all founded by members of the Serbian royalty. The murals of these churches originally featured backgrounds covered with gold leaf and patterned to mimic mosaic cubes—an expensive and fragile form of decoration of which only traces now survive. Research was conducted through a combination of in situ examination, sampling and laboratory microanalyses, with the aim to identify the composition of the materials used and to reconstruct the painters' working methods. The results reveal a highly unusual, even experimental, system of gilding. In all but one instance, the painters employed leaves of what is known as 'part gold'—a laminate produced by beating two sheets of gold and silver together, which was seldom applied to images on the wall and never on such a massive scale. The article's goal is twofold: first, to present new data on an important and innovative, yet poorly understood, form of decoration; and second, to lay the foundation for a comprehensive art‐historical study of the Serbian gilded murals with simulated tessellation and their significance for understanding the changing dynamic between painting and mosaic in the later Middle Ages. [ABSTRACT FROM AUTHOR]

A series of industrial chitosans were analyzed on the presence of residual heavy metals. For the first time, optical microscopy data showed that chitosan solution retained a huge number of insoluble microparticles while transmittance electron microscopy revealed that insoluble fibrous microparticles were incrusted by crystalline nanoparticles with the sizes 5–50 nm. A series of filters used for chitosan solution filtration was analyzed on the presence of retained heavy metal and other residuals by scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDXS) and mass-spectrometry with inductively coupled plasma (ICP-MS) methods. The SEM-EDXS analysis revealed the presence of Fe residuals together with Si, Al, N and S in the particles found on the filters. ICP-MS analysis found the presence of heavy metals (mainly Fe, Cr and Ni) both on the filter surfaces and in the effluent chitosan solution passed though the filters. This study draws attention to the necessity of a careful selection of industrially manufactured chitosan in order to avoid hidden undesirable effects of chitosan on pharmaceuticals and biomaterials and gives a warning of inapplicability of a stainless-steel made apparatus as a reactor susceptible to caustic soda corrosion for chitin deacetylation and production of medical and food grade chitosan. • Industrial chitosan contains insoluble microparticles. • Microparticles include crystalline nanoparticles 5–50 μm in sizes. • Nanoparticles contain heavy metal residuals. • Heavy metal residuals cannot be separated from chitosan. • Choose chitosan carefully in order to avoid hidden undesirable effects of the biomaterial [ABSTRACT FROM AUTHOR]

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• Importance of ancient coins in historical and archaeological studies. • Materials analyses difficult for surface altered layers. • Possibility to measure coin alloy composition. • Experimental protocol for a full alloy characterization. • Non-destructive multi-analytical approach is being developed. The material study of ancient coins is very often rendered particularly challenging by several factors: the presence of surface alteration products; the occasional or deliberate, e.g., forgery, changes in the composition of the base alloy; the misleading information deriving from historical and literature sources. We present herewith a multi-analytical approach to the study of ancient coins. The selected test samples are coins widely used in the Venetian Republic over a time span ranging from the second half of the 16th until the early years of the 17th century: the so-called " sesino ". The rationale of the study was to establish a model, taking into account the layered structure of the surface region of the coins, that once validated could be used for a fully non-destructive characterization of similar items. The specific interest of the results obtained from this investigation is twofold. First, the actual composition of the copper based alloy used for these specific type of Venetian coin, has been measured for the first time with direct measurements on the coin cross-section. Second, the detailed characterization of the coins provides an essential background knowledge for a fully non-destructive characterization of the same kind of coins. [ABSTRACT FROM AUTHOR]

This study revaluates reported cases of prehistoric As-Cu objects with ‘silvery surfaces’, which are usually interpreted as the result of inverse segregation. Further possible explanations for such surfaces, such as an arsenic-rich α-solid solution, cementation, or post-depositional precipitation, are discussed. The segregation of arsenic was studied in As-Cu ingots produced in chill cast moulds at several compositions, which underwent surface treatment with an NaCl solution. The microstructure and surfaces of the As-Cu alloys were analysed using optical microscopy and SEM-EDXS. Special note of out-of-equilibrium As-Cu phases are discussed, as well as a comparison of inverse segregation to all other means of achieving surface silvering. [ABSTRACT FROM AUTHOR]

Lead chromate was commonly employed as a pigment in coloured road markings until restrictions led to the development of safer alternatives. In this study, the presence and concentrations of Pb and Cr have been determined in 236 road paints of various colours sampled from streets, highways, footways and carparks from eleven European countries. According to energy-dispersive X-ray fluorescence spectrometry, Pb was detected (>10 mg kg−1) in 148 samples at concentrations up to 17.2% by weight, and above 1000 mg kg−1 yellow was the dominant paint colour. Lead concentrations on an area basis varied from 0.02 to 8.46 mg cm−2 and the metal was located at different depths amongst the samples, suggesting that formulations had been painted both recently and historically (and overpainted). Chromium was detected (>5 to 50 mg kg−1) in 81 samples at concentrations between 20 and 20,000 mg kg−1 and most often in yellow paints, and concentrations co-varied with those of Pb. These observations, and results of scanning electron microscopy coupled with energy-dispersive X-ray spectrometry, suggested that heterogeneously dispersed PbCrO 4 was the dominant, but not the only, Pb-based pigment in the samples. Although there were significant international differences in frequency of Pb detection and median Pb concentrations, overall, and despite various, albeit complex, regulations, recent or extant road paint pigmented with Pb and Cr remains a pervasive environmental problem and a potential health risk in many European countries. [Display omitted] • Pb detected in 148 out of 236 European road paints at concentrations up to 17.2%. • Cr detected in 81 samples with concentrations up to 20,000 mg kg−1. • High Pb and Cr mainly present in yellow paints and as the pigment, PbCrO 4. • Depth analysis indicates both recent and historical applications of PbCrO 4. • Despite (complex) regulations, Pb and Cr remain an environmental concern and health risk. [ABSTRACT FROM AUTHOR]

The corrosion of copper in 0.25 M sulphuric acid was studied by the addition of aqueous extract of leaves of Morinda tinctoria using weight loss and electrochemical methods. The addition of inhibitor moderately improves the inhibition efficiency. Increase in temperature and acid concentration decreases the performance of the inhibitor. The adsorption of the inhibitor on the copper surface in sulphuric acid medium obeys Freundlich isotherm. The AC impedance studies reveal that the process of inhibition is through charge transfer reaction, and polarization studies indicate the mixed nature of the inhibitor. [ABSTRACT FROM AUTHOR]

We have investigated the biomineralisation of barite ‒a useful proxy for reconstructing paleoproductivity‒ in a freshwater alga, Spirogyra , by combining in vitro and in vivo approaches to unveil the nature of its barite microcrystals. Scanning electron microscope (SEM) and energy-dispersive X-ray spectroscopy (EDXS) observations on simply dried samples revealed that the number and size of barite crystals were related to the barium concentration in the media. Additionally, their morphology showed a crystallographic face (011), which is not normally observed, suggesting the influence of organic molecules on the growth kinetics. The critical point drying method was used to preserve the internal and external structures of Spirogyra cells for SEM imaging. Crystals were found adjacent to the cytoplasmic membrane, near chloroplasts and fibrillary network. In vivo optical microscopy and Raman tweezer microspectroscopy in living cells showed that barite microcrystals are optically visible and follow cytoplasmic streaming. These results led us to propose that barite formation in Spirogyra occurs in the cytoplasm where barium and sulphate are both available: barium supplied non-selectively through the active transport of the divalent cations needed for actin polymerisation, and sulphate because necessary for amino acid biosynthesis in chloroplasts. [ABSTRACT FROM AUTHOR]

The effect of aqueous extract of leaves of Morinda tinctoria on the corrosion inhibition of copper in 0.5 M hydrochloric acid was studied using weight loss and electrochemical techniques. Results obtained from weight loss data indicate that the extract is effective in hydrochloric acid medium and the efficiency increases with an increase in the exposure time. The increase in temperature and acid concentration decreases the inhibitor efficiency. The data for the adsorption of extract fit well with Freundlich isotherm. The AC impedance studies reveal that the process of inhibition is through charge transfer reaction. [ABSTRACT FROM AUTHOR]

Alumina may display a complex polymorphism depending on the production method. Starting from Al-solution, their amorphous or crystalline structures as well as its phase are strongly determined by the precursor, temperature, pressure, pH, etc. However, starting from Al containing solids, there is a lack of information about the procedure to obtain a determined phase and concerning the influence of its surface finish on the morphological texture of the alumina growth. In this work, Fe22Cr5Al plates were subjected to mirror polishing and mechanical erosion. The fractal dimension determined from optical images was 2.084 for mirror polished samples and 2.472 for the eroded ones; these values give a comparative element for the starting surface finishing, because a higher fractal dimension value means an increasing surface roughness. Thereafter, both samples were oxidized at 900 °C, 24 h in air. By SEM, the polished-oxidized samples show a passivation layer formed by agglomeration of relative small particles, of around 400 nm; whereas the eroded-oxidized samples show whiskers with 100 nm thickness. The fractal dimension determined from SEM images was 2.511 for the polished-oxidized samples and 2.582 for the eroded-oxidized ones. EDXS analysis detects Al and O enrichment at the surface and XRD identifies the ? and a phases of alumina, for both kind of surface finish. Results demonstrate that the difference found in the oxide morphology is directly related to the surface finish before oxidation. This in turn is attributed to the difference in the surface defects density acting as nucleation centers for alumina whiskers. [ABSTRACT FROM AUTHOR]

Abstract: Ni-based superalloy 690 substrates were pack aluminized in a low Al-containing pack at 1273K for 4h in argon atmosphere. Scanning electron microscopy with energy dispersive X-ray analysis along the cross section of aluminized specimen revealed the formation of multilayer. The uppermost layer consisted of NiAl type phase (~45μm), while adjoining one composed of (NiCr)Al and (NiCr)2Al types layer (~25μm) and subsequently Cr-rich layer (~35μm) adjacent to substrate. Al-content was found to increase while moving from Cr-rich layer towards outer layer. Cross-sectional transmission electron microscopy confirmed the formation of NiAl layer on the topmost surface and revealed the formation of nanoparticles of nickel aluminide on the uppermost surface. Microhardness was found to vary from 624 to 157 Vickers hardness number along the cross section of aluminized substrate indicating high, intermediate and low values for NiAl, Cr-rich layer and substrate, respectively. To evaluate the adherence of multilayer, scratch test was performed along the cross section of aluminized substrate at a constant load level of 2N at ambient temperature. For aluminides, a decrease in friction coefficient with the decrease in Al-content was noticed. Cr-rich layer showed lowest friction coefficient, while its variation was little for substrate. Aluminide layers indicated lower penetration depth than the substrate, whereas no penetration was recorded for Cr-rich layer. Scratched surface did not reveal any peeling off either at the multilayer or layer/substrate interface indicating their good adherence. Aluminized specimens showed good overall oxidation resistance at 1273K in air due to the formation of α-Al2O3. First-principle spin-polarized calculations on Ni(111)/NiAl(110) interface indicated strong adhesion (Ideal work of adhesion, W ad (ideal)=3684mJ/m2; lowest bound value) arising from strong metallic Ni d Ni d interaction and covalent Ni d Al p mixing of states. [Copyright &y& Elsevier]

Abstract: Archaeometric analyses on conical and decorated cap helmets from the Bronze Age are presented. The helmets are dated to the 14–12th century BC according to associated finds in hoards. Alloy composition, material structure and manufacturing processes are determined and shed light on the earliest development of weaponry production in Central and Eastern Europe. Analyses were carried out using light and dark field microscopy, SEM–EDXS, PIXE, TOF-ND and PGAA. The results allowed reconstructing the manufacturing process, the differences between the cap of the helmets and their knobs (i.e. alloy composition) and the joining technique of the two parts. [Copyright &y& Elsevier]

The article discusses the determination of curing kinetics of diglycidyl ether of bisphenol A (DGEBA) epoxy and ground mechanochemical devulcanized ground rubber tire composite systems using non-isothermal differential scanning calorimetry at various heating rates. Other topics include average activation energy, the use of a two parameter autocatalytic model, and heat flow curves.

In order to contribute to the improvement of restoration and conservation sciences of metallic artefacts belonging to Cultural Heritage, a wide research has been started on the study of artificial (artistic) and natural (corrosion or alteration) patinas of copper-based alloys. Micro-Raman spectroscopy (μRS) coupled with scanning electron microscopy (SEM) equipped with energy Dispersive X-Ray Spectroscopy (EDXS) were applied for the characterization of a number of patinas made on metallic substrate reproducing the typical copper-based alloys used for statuary. A non alloyed copper sheet has been also used to simulate the architectural cover typically used after a specific cold spray coating. To reach these goals, a number of patinas were experimentally produced in our laboratory using the torch technique and reactive solutions based on water as a solvent containing, respectively, copper nitrate, iron nitrate and potassium sulfide ('liver of sulfur'). The only exception is a sample reproducing the architectural cover of a recent building nearly completely covered with copper sheets coated with copper salts. All the produced patinas were aged in a salt spray chamber and then studied with μRS, SEM and EDXS in order to understand their evolution between the two known terms and therefore the reactions involved in all patinas. μRS allowed us to detect as main constituents of the 'artistic' patinas, before and after ageing: copper oxides ( Cuprite and Tenorite), copper nitrates ( Rouaite and Gerhardtite), copper chlorides ( Botallackite, Atacamite and Paratacamite), a copper sulfate ( Posnjakite), iron oxides ( Magnetite and Hematite) and an iron hydroxide ( Limonite). Copyright © 2012 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Innovative engineering design for biologically active hydroxyapatites requires enhancing both mechanical and physical properties, along with biocompatibility, by doping with appropriate chemical elements. Herein, the purpose of this investigation was to evaluate and elucidate the model of naturally occurring hydroxyapatite and the effects of doped trace elements on the function of normal human fibroblasts, representing the main cells of connective tissues. The substrates applied (geological apatites with hexagonal prismatic crystal habit originated from Slyudyanka, Lake Baikal, Russia (GAp) and from Imilchil, The Atlas Mountains, Morocco (YAp)) were prepared from mineral natural apatite with a chemical composition consistent with the building blocks of enamel and enriched with a significant F− content. Materials in the form of powders, extracts and single-crystal plates have been investigated. Moreover, the effects on the function of fibroblasts cultured on the analyzed surfaces in the form of changes in metabolic activity, proliferation and cell morphology were evaluated. Apatite plates were also evaluated for cytotoxicity and immune cell activation capacity. The results suggest that a moderate amount of F− has a positive effect on cell proliferation, whereas an inhibitory effect was attributed to the Cl− concentration. It was found that for (100) GAp plate, fibroblast proliferation was significantly increased, whereas for (001) YAp plate, it was significantly reduced, with no cytotoxic effect and no immune response from macrophages exposed to these materials. The study of the interaction of fibroblasts with apatite crystal surfaces provides a characterization relevant to medical applications and may contribute to the design of biomaterials suitable for medical applications and the evaluation of their bioavailability. [ABSTRACT FROM AUTHOR]

Kohl is an eye cosmetic that was traditionally used in many Asian and African countries but that is now more widely available. Ingredients of kohl reported in previous studies seem to be rather variable but mention is frequently made of minerals based on Pb whose use in cosmetic products is prohibited in Europe. We purchased 23 products of kohl from retail outlets in five different European countries and over the internet and analysed their chemical composition by XRF and SEM-EDXS. The majority of the products (n = 17) did not conform with European legislation based on the presence of Pb (often as galena), whose concentrations ranged from a few mg kg−1 to over 400000 mg kg−1. Cadmium, another element prohibited in cosmetic products in Europe, was also present as a contaminant in 13 products at concentrations up to a few hundred mg kg−1. In addition to heavy metals, minerals of other metals (e.g. Fe and Zn) appeared to be present in the nano-size range and might represent an additional health hazard. Clearly, the lack of quality control in the manufacture of kohl results in the widespread occurrence of toxic and unwanted elements and the trade of illegal products in Europe. In principle, shop sales would be relatively straightforward to prevent, but products traded through internet are more difficult to regulate. • Kohl cosmetics were purchased in Europe from retail outlets and over the internet. • Samples (n = 23) were analysed by portable XRF and SEM-EDXS. • Pb was detected in 17 kohls at concentrations ranging from a few mg kg−1 to >400 g kg−1. • Cd was also present as a trace contaminant in 13 products. • The study reveals lack of quality control in manufacture and an illegal trade in Europe. [ABSTRACT FROM AUTHOR]