Clay-based pigments are among the most traditional. Unlike other mineral pigments, they have never been fully replaced by synthetic analogues and are still used in painting today. Since their ...analysis requires a specific approach, detailed distinction of clay pigments has never been a part of routine chemical-technological research in fine arts—regardless of a great potential of clay minerals for determining regional provenance of the material. This review article maps and summarizes research on clay pigments in historical paintings that has been systematically pursued by authors since the beginning of this millennium. This rallying and interconnection of knowledge was an opportunity for a new reflection on the common aspects of these research projects, either methodological or interdisciplinary, since these findings are closely related to art-historical evaluation of artworks. It offers a comprehensive insight into the microanalysis of clay pigments with using powder X-ray micro-diffraction and complementary methods. Significant new findings come, for example, from research on the Italian Baroque. It becomes clear that cheap availability of raw material, pottery clays, could have played an important role in the change in painting technology at the turn of the 16th and 17th centuries.
Abstract Titanium and its alloys are commonly used in modern implantology. Cell viability on the surface of titanium implants depends on the surface topography, roughness, and wettability. Laser ...treatment is a successful method to control the surface morphology. The aim of this study was to comprehensively investigate the effects of laser ablation on titanium surfaces and their interactions with cells and bacteria. Cell adhesion, proliferation, and bacterial retention on smooth and laser-textured samples of commercially pure and nanostructured titanium of two grades were evaluated. Femtosecond laser treatment effectively enhances the wettability. Titanium grade four exhibits superior adhesion and proliferation rates when compared to titanium grade two. The cytotoxicity of nanostructured titanium is significantly lower, regardless of the surface treatment. Laser treatment resulted in increased short-term cell proliferation on grade two titanium and long-term cell proliferation on nanostructured grade two titanium only. Although the laser ablation has a limited effect on bacterial adhesion, the coverage of less than 1% in most samples indicates that the material itself has an antibacterial effect on the bacterial strain Streptococcus oralis . These findings provide valuable insights into how different material structures and surface treatments can affect cellular response and antibacterial properties for potential use in dental implantology.
Ledeburitic tool steel X210Cr12 was processed by passing through a semi-solid state with subsequent forming on a hydraulic press, thus achieving a fine-grained martensitic matrix, uniformly dispersed ...fine precipitates, and removal of sharp-edged primary chromium carbides. The hardness value was over 700 HV10. The decomposition of austenite and the promotion of further carbide precipitation were carried out by cryogenic treatment or a combination of cryogenic treatment and tempering. Transmission electron microscopy showed that tempering after cryogenic treatment also led to the precipitation of needle-like M3C carbide, unlike the previous regimes. Furthermore, after the combined treatment, the microstructures showed a significant wear resistance, which was detected both by a waterjet abrasive blast test and a laboratory pin on disk test. Both tests showed a significant increase in wear resistance compared to the initial condition and special high wear resistance steels, such as Hardox 450 and Hardox 600.
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•An analytical procedure for identification of Cu pigments in artworks is presented.•This procedure is efficient for both mineral and verdigris-type pigments.•It consists of detailed ...elemental and structural analyses and is non-destructive.•Preliminary study of the verdigris’ loss of crystallinity has been performed.
An unambiguous identification of pigments in paint layers of works of art forms a substantial part of the description of a painting technique, which is essential for the evaluation of the work of art including determination of the period and/or region of its creation as well as its attribution to a workshop or an author. Copper pigments represent a significant group of materials used in historic paintings. Because of their substantial diversity and, on the other hand, similarity, their identification and differentiation is a challenging task. An analytical procedure for unambiguous determination of both mineral-type (azurite, malachite, posnjakite, atacamite, etc.) and verdigris-type (copper acetates) copper pigments in the paint layers is presented, including light microscopy under VIS and UV light, electron microscopy with elemental microanalysis, Fourier transformed infrared micro-spectroscopy (micro-FTIR), and X-ray powder micro-diffraction (micro-XRD). Micro-Raman measurements were largely hindered by fluorescence. The choice of the analytical methods meets the contemporary requirement of a detailed description of various components in heterogeneous and minute samples of paint layers without their destruction. It is beneficial to use the combination of phase sensitive methods such as micro-FTIR and micro-XRD, because it allows the identification of both mineral-type and verdigris-type copper pigments in one paint layer. In addition, preliminary results concerning the study of the loss of crystallinity of verdigris-type pigments in proteinaceous binding media and the effect of lead white and lead tin yellow as highly absorbing matrix on verdigris identification in paint layers are reported.
Clay minerals and iron oxides are intimately related in the process of their natural formation. Their mineralogical composition and physical properties correspond to the physical–chemical conditions ...of weathering, sedimentation and alteration processes by means of which these minerals are associated giving different types of laterites, ferrolites, ochres, and coloured clays and soils. Very early in human history, these and other clay materials were adopted as mineral pigments. Their structural and mineralogical features are directly related with their natural genesis and provenance and help us in the study of historical painting techniques and materials. This paper gives general information about geological sources and their characteristics, the literary evidence of use of different forms of earthy pigments on historical paintings, about analytical methods suitable in their identification within the ground and colour layers of the painting, and handling with the samples of works of art. The examples focused preferentially on the period of European mediaeval and baroque painting.
During endoscopic procedures for suspected urothelial tumors of the upper urinary tract, radiographic imaging using an iodinated contrast medium is often required. However, following ...ureteropyelography, we detected changes in cytology characteristics not correlating with real cytology findings in naive urine. The aim of our study was to assess cytology changes between naive and postcontrast urine according to The Paris System of cytology classification. Methods: We prospectively assessed urine samples from 89 patients (23 patients with histologically proven urothelial cancer and 66 healthy volunteers). The absence of malignancy was demonstrated by CT urography and/or ureteroscopy. The study was single blind (expert cytopathologist) and naïve Paris system for urine cytology assessment was used. Furthermore, additional cytological parameters were analyzed (e.g., specimen cellularity, degree of cytolysis, cytoplasm and nucleus color, chromatin and nucleo-cytoplasmic ratio). Results: Our study showed statistically significant differences when comparing naïve and postcontrast urine in healthy volunteers (only 51 % concordance, p = 0.001) versus malignant urine specimens (82 % concordance). The most important differences were in the shift from The Paris System category 2 (negative) to 1 (non-diagnostic) and from category 2 (negative) to 3 (atypia). Other significant changes were found in the assessment of specimen cellularity (p = 0.0003), degree of cytolysis (p = 0.001), cytoplasm color (p = 0.003), hyperchromasia (p = 0.001), course chromatin (p = 0.002), nucleo-cytoplasmatic ratio (p = 0.001) and nuclear borders’ irregularity (p = 0.01). Conclusion: Our unique study found crucial changes in the cytological assessment of naive and postcontrast urine and we confirm that postcontrast urine is more often assessed as abnormal, suspect or non-diagnostic. Therefore, before urine collection for cytology, the clinician should avoid administration of iodinated contrast into the urinary tract.
The uniqueness and limited amounts of forensic samples and samples from objects of cultural heritage together with the complexity of their composition requires the application of a wide range of ...micro-analytical methods, which are non-destructive to the samples, because these must be preserved for potential late revision. Laboratory powder X-ray micro-diffraction (micro-XRD) is a very effective non-destructive technique for direct phase analysis of samples smaller than 1 mm containing crystal constituents. It compliments optical and electron microscopy with elemental micro-analysis, especially in cases of complicated mixtures containing phases with similar chemical composition. However, modification of X-ray diffraction to the micro-scale together with its application for very heterogeneous real samples leads to deviations from the standard procedure. Knowledge of both the limits and the phenomena which can arise during the analysis is crucial for the meaningful and proper application of the method. We evaluated basic limits of micro-XRD equipped with a mono-capillary with an exit diameter of 0.1 mm, for example the size of irradiated area, appropriate grain size, and detection limits allowing identification of given phases. We tested the reliability and accuracy of quantitative phase analysis based on micro-XRD data in comparison with conventional XRD (reflection and transmission), carrying out experiments with two-phase model mixtures simulating historic colour layers. Furthermore, we demonstrate the wide use of micro-XRD for investigation of various types of micro-samples (contact traces, powder traps, colour layers) and we show how to enhance data quality by proper choice of experiment geometry and conditions.
Nitriding with subsequent heat treatment in combination with deep cryogenic treatment (DCT) produces nitrided layers with specific properties. Layers with unique properties result from the ...dissolution of subsurface layers of iron nitrides and subsequent nitrogen diffusion into the substrate during austenitisation. Fine precipitates of carbonitrides eventually form during DCT and tempering. Intermediate deep cryogenic treatment was performed between the quenching and tempering steps. This work is based on comparing nitrided layers obtained using conventional treatment parameters with nitrided layers from novel processes. The experimental material was DIN 1.3343 (Czech Standard 41 9830) high-speed steel. Several treatment methods were compared in terms of the resulting hardness and metallographic characteristics.
Metallurgical slags from primary lead smelting were submitted to a 30-day batch leaching procedure in 20 and 8 mM citric solutions in order to determine the kinetics of release of Pb, Cu, Zn and As. ...The experiment was coupled with the PHREEQC-2 speciation-solubility modelling and mineralogical study of newly formed products (SEM/EDS, XRD, TEM/EDS and Raman spectrometry). A strong scavenging of metals and metalloids from the 8 mM citric leachate was observed due to the formation of newly formed products. The secondary precipitate consisted of well-developed calcite (CaCO
3) crystals and amorphous organo-mineral matrix composed of hydrous ferric oxides and amorphous SiO
2. Metals (Pb, Zn, Cu) and arsenic released into the solution were subsequently bound onto the newly formed product (adsorption on oxides) or trapped within the calcite structure (Zn, Mn). Similar scavenging mechanism can be taken into account in real soil systems with lower concentration of citric acid. Then, the covering of slag dumps with a thick soil layer and subsequent re-vegetation might be a possible scenario for slag management on some metallurgical sites.
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