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Lead soaps in paintings: symptoms and the role of humidity
Garrappa, Silvia ; Švarcová, Silvie ; Kočí, Eva ; Hradilová, J. ; Bezdička, Petr ; Hradil, David
In this study, an overview of the symptoms of lead soaps reported in artworks in combination\nwith the study of the role of humidity on the formation of these degradation products have\nbeen thoroughly investigated. The use of optical microscopy, scanning electron microscopy\n(SEM) in combination with Fourier-transform infrared spectroscopy (FTIR) proved to be an\nefficient analytical approach to highlight both the saponified area of artworks’ samples and the\nformation of metal carboxylates within mock-up model systems. Optical microscopy revealed\nto be very useful for the first screening of samples embedded in resin, while SEM helped in\nthe detection and distribution of elements within the cross-sections. On the other hand, FTIR\nmicroscope proved to be a very powerful instrument for high-resolution point measurements\nperformed in the attenuated total reflection mode (ATR) mode with mercury-cadmium-telluride\n(MCT) detector, as well as for chemical imaging of larger area of both artworks’ and mock-up\nsamples performed in the ATR mode with focal plane arrays (FPA) detector. This study provides\nnew useful insights contributing to better understanding of factors affecting the paints‘ stability,\nwhich is neccesary for developing new efficient strategies for preservation and restoration of\nfatty-based painted artworks.
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Financial analysis of chosen company
Švarcová, Silvie ; Homolka, Jaroslav (advisor) ; Michal, Michal (referee)
This bachelor thesis on the topic of financial analysis of chosen company is engaged in assessing the financial situation of the joint-stock company První zemědělská a.s. Tuněchody in the period from 2010 to 2014. The thesis consists of theoretical and practical part. Theoretical part describes basic concepts and methods of financial analysis. In the practical part is based on the actual data of the chosen company to calculate basic indicators of financial analysis. For the overall evaluate of the financial situation are utilized chosen bankruptcy and creditworthy models. Based on the obtained result it can be stated that the enterprise has no problems with the payment of its obligations. The funding is used mainly equity. Smaller drawing fund from foreign sources indicates a high financial independence of the company. Of the indicators of liquidity is found to be capable of undertaking the payment. Overall assessment of the financial situation is positive, the company is financially sound and will not bankrupt in future.
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Signs of degradation of czech art nouveau mosaic glasses
Rohanová, D. ; Švarcová, Silvie ; Hájek, T.
Analyses of Art Nouveau mosaics from the church of St. Simon and Juda in Dolín near Slaný and from Holovousy, both most likely made by the workshop of Viktor Foerster, have shown that the author used the NaO-PbO-SiO 22 glass type and that he used the same glass also for restoration of The Last Judgment mosaic at the Prague Castle in 1890-1910. Despite the fact that lead glasses are more durable than potassium glasses, the material investigations identified corrosion processes on the surface of the glass pieces (tesserae) depending on their composition. Apart from the analyzed mosaic NaO-PbO-SiO2 glasses, we also used ancient sodium glasses (NaO-CaO-SiO2) and 22 potassium glasses (K2O-CaO-SiO2) from archaeological finds in Opava to demonstrate their different chemical durability. We also paid attention to fixation binders used in Art Nouveau mosaics. Inappropriate use of gypsum-containing binders is a significant cause of disintegration of the mosaics. Gypsum and gypsum-lime plasters are very sensitive to humidity. Capillary action of water is a very serious problem that endangers the overall lifespan of any mosaic.
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Gothic painted decorations in the Gallery of the castle in Lidzbark Warminski
Hradil, David ; Hradilová, J. ; Švarcová, Silvie ; Bezdička, Petr ; Čermáková, Zdeňka ; Bartlová, M.
Materials research was aimed at finding specific characteristics, which could indicate the provenance of mural paintings uncovered in Bishops castle in Lidzbark Warmiński, northeast Poland. An expected relation of these murals to Bohemian artistic workshops, which were active in the 14th century at the Emperor Charles IV’s court in Prague, was supported by further exact data. The lead-tin yellow – type II was identified by X-ray microdiffraction; up to the present day, this uncommon modification of the pigment was proved solely in the Bohemian painting of the 14th century (e.g. Master of Třeboň altarpiece) and in the Italian painting of the 14th to 16th century. Nickel is an element accompanying natural iron-based pigments and was found both in the painting and the drawing, respectively. It is possible to demonstrate that this admixture indicates the source locality of the pigment in Lower Silesia, which belonged to the Kingdom of Bohemia in the 14th century and was exploited for chrysoprases – green gemstones frequently appearing in Bohemian jewellery and wall decorations (St. Wenceslas chapel in the Prague’s cathedral, Karlštejn Castle). Lidzbark murals exhibit features similar to the panel painting, e.g. the use of tempera, natural chalk in the preparatory layer, lead pigments and madder lakes in the painting. The madder was extracted from the wool fibres, which are still clearly visible in the samples.
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Origin, composition and stability of copper pigments in wall paintings
Švarcová, Silvie ; Bezdička, Petr ; Hradil, David
Blue and green copper pigments occur in a wide range of chemically close, although mineralogically different species, which makes their proper identification nontrivial. Furthermore, they can be of various origins – natural, artificial or formed as a result of corrosion of another copper pigment. The degradation of copper pigments is a serious problem in case of artworks exposed to corrosive environment, such as wall paintings or exterior stone polychromes. In this paper, we document the variability of copper pigments used in history on examples of selected wall paintings. The problem of origin and stability of copper pigments in wall paintings is solved using advanced microanalytical investigation of paint layers together with the laboratory experiments. Microanalytical features documenting natural or artificial origin of copper pigments as well as their secondary changes caused by corrosive environment are shown and discussed.
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Signs oF degradaTion oF czech arT nouveau mosaic glasses
Rohanová, D. ; Švarcová, Silvie ; Hájek, T.
Analyses of Art Nouveau mosaics from the church of St. Simon and Juda in Dolín near Slaný and from Holovousy, both most likely made by the workshop of Viktor Foerster, have shown that the author used the NaO-PbO-SiO 22 glass type and that he used the same glass also for restoration of The Last Judgment mosaic at the Prague Castle in 1890-1910. Despite the fact that lead glasses are more durable than potassium glasses, the material investigations identified corrosion processes on the surface of the glass pieces (tesserae) depending on their composition. Apart from the analyzed mosaic NaO-PbO-SiO2 glasses, we also used ancient sodium glasses (NaO-CaO-SiO2) and 22 potassium glasses (K2O-CaO-SiO2) from archaeological finds in Opava to demonstrate their different chemical durability. We also paid attention to fixation binders used in Art Nouveau mosaics. Inappropriate use of gypsum-containing binders is a significant cause of disintegration of the mosaics. Gypsum and gypsum-lime plasters are very sensitive to humidity. Capillary action of water is a very serious problem that endangers the overall lifespan of any mosaic.
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Origin, composition and stability of copper pigments in wall paintings
Švarcová, Silvie ; Bezdička, Petr ; Hradil, David
Blue and green copper pigments occur in a wide range of chemically close, although mineralogically different species, which makes their proper identification nontrivial. Furthermore, they can be of various origins – natural, artificial or formed as a result of corrosion of another copper pigment. The degradation of copper pigments is a serious problem in case of artworks exposed to corrosive environment, such as wall paintings or exterior stone polychromes. In this paper, we document the variability of copper pigments used in history on examples of selected wall paintings. The problem of origin and stability of copper pigments in wall paintings is solved using advanced microanalytical investigation of paint layers together with the laboratory experiments. Microanalytical features documenting natural or artificial origin of copper pigments as well as their secondary changes caused by corrosive environment are shown and discussed.
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Gothic painted decorations in the Gallery of the castle in Lidzbark Warminski a bohemian track in northern poland ii.: materials signs of provenance
Hradil, David ; Hradilová, J. ; Švarcová, Silvie ; Bezdička, Petr ; Čermáková, Zdeňka ; Bartlová, M.
Materials research was aimed at finding specific characteristics, which could indicate the provenance of mural paintings uncovered in Bishops castle in Lidzbark Warmiński, northeast Poland. An expected relation of these murals to Bohemian artistic workshops, which were active in the 14th century at the Emperor Charles IV’s court in Prague, was supported by further exact data. The lead-tin yellow – type II was identified by X-ray microdiffraction; up to the present day, this uncommon modification of the pigment was proved solely in the Bohemian painting of the 14th century (e.g. Master of Třeboň altarpiece) and in the Italian painting of the 14th to 16th century. Nickel is an element accompanying natural iron-based pigments and was found both in the painting and the drawing, respectively. It is possible to demonstrate that this admixture indicates the source locality of the pigment in Lower Silesia, which belonged to the Kingdom of Bohemia in the 14th century and was exploited for chrysoprases – green gemstones frequently appearing in Bohemian jewellery and wall decorations (St. Wenceslas chapel in the Prague’s cathedral, Karlštejn Castle). Lidzbark murals exhibit features similar to the panel painting, e.g. the use of tempera, natural chalk in the preparatory layer, lead pigments and madder lakes in the painting. The madder was extracted from the wool fibres, which are still clearly visible in the samples.
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Determination of clay pigment provenance rased on crystal structure characterisation
Švarcová, Silvie ; Bezdička, Petr ; Hradil, David ; Žižak, I.
Application of X-ray diffraction techniques (XRD) in material analysis of artworks is beneficial in several aspects. Primarily it provides indisputable identification of crystal components found in colour layers, further it makes quantification of identified phases possible and last but not least it can also bring insight in material crystal structure. The crystal structure of materials is often affected by conditions which have been formed under, e.g. geological genesis, manufacturing procedure or secondary changes for example resulted from corrosive action of environment. The knowledge of the relation between the crystal structure of the material and its formation can be useful not only for art historic evaluation of the artwork but also for the artwork restoration and/or conservation. Within the example of clay mineral kaolinite, we show that its crystal order evaluation (based on XRD) can serve well to find its natural origin. We found kaolinite, the main component of kaolin (white earth), in a preparation layer of a Gothic wall painting in St. Maria-Magdalena Church in Bor near Karlovy Vary, where important kaolin deposits are situated. Comparing eight reference kaolins, we demonstrated that these can be differentiated just according to the kaolinite crystallinity (crystal structure ordering). Within this study we compared laboratory powder X-ray micro-diffraction (micro-XRD) with synchrotron radiation X-ray diffraction (SR-XRD). We found that both techniques led to the same results.
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