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Anti-B18H22: A Brand-New Laser Material
Cerdán, L.; Braborec, Jakub; Garcia-Moreno, I.; Costela, A.; Londesborough, Michael Geoffrey Stephen
2014 - English
The first laser borane, anti-B18H22, exhibits blue laser emission at 406nm with an efficiency of 9.5 % and a photostability superior to that of commercial laser dyes, providing a new solution to an old problem.
Keywords:
Laser excitation; Measurement by laser beam; Chemical lasers
Available at various institutes of the ASCR
Anti-B18H22: A Brand-New Laser Material
The first laser borane, anti-B18H22, exhibits blue laser emission at 406nm with an efficiency of 9.5 % and a photostability superior to that of commercial laser dyes, providing a new solution to an ...
Signs of degradation of czech art nouveau mosaic glasses
Rohanová, D.; Švarcová, Silvie; Hájek, T.
2012 - English
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.
Keywords:
glass mosaic; tesserae; glass corrosion; Victor Foerster; lead glass; Art Nouveau
Available at various institutes of the ASCR
Signs of degradation of czech art nouveau mosaic glasses
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 effects of artificial ageining on model colour layeres containing neutral verdigris
Bauerová, P.; Bezdička, Petr
2012 - English
Verdigris belongs to traditional painting pigments. In artworks it most often occurs in combination with lead-tin yellow or lead white. However, its colour is considered unstable. The aim of this study was to find out which conditions contribute to colour changes of the most frequently used neutral verdigris (hoganite) Cu(CH3COO)2.H2O and whether these changes happened as a result of the assumed verdigris-binder interactions or caused by the degradation of the pigment itself. The article summarises first results of artificial ageing experiments.
Keywords:
neutral verdigris; artificial ageing; colour change; degradation
Available at various institutes of the ASCR
The effects of artificial ageining on model colour layeres containing neutral verdigris
Verdigris belongs to traditional painting pigments. In artworks it most often occurs in combination with lead-tin yellow or lead white. However, its colour is considered unstable. The aim of this ...
Origin, composition and stability of copper pigments in wall paintings
Švarcová, Silvie; Bezdička, Petr; Hradil, David
2012 - English
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.
Keywords:
copper pigments; wall paintings; origin; corrosion
Available at various institutes of the ASCR
Origin, composition and stability of copper pigments in wall paintings
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 ...
Gothic painted decorations in the Gallery of the castle in Lidzbark Warminski
Hradil, David; Hradilová, J.; Švarcová, Silvie; Bezdička, Petr; Čermáková, Zdeňka; Bartlová, M.
2012 - English
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.
Keywords:
Lidzbark Warmiński; Gothic mural paintings; ni-bearing laterite; chrysoprase; lead-tin yellow
Available at various institutes of the ASCR
Gothic painted decorations in the Gallery of the castle in Lidzbark Warminski
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 ...
Newly Found romanesque madonna of Sedes sapientiae type coming from a czech private collection with elements of west european fine arts tradition
Hradilová, J.; Hradil, David; Fogaš, I.; Zmydlená, M.
2012 - English
On the basis of material research, the oldest preserved polychrome carving of Madonna of Sedes sapientiae type was dated using radiocarbon method 14C to the interval of 990 – 1180. During the non-destructive research, we could observe its inner structure on the CT scans and a careful sampling enabled us to determine the technological features typical for this outstanding polychromy. These features comprise, above all, the oldest siliceous ground of specific composition, which had a practical relevance. The coloured, or only coarse-grained lower ground layer, served as a check for the depth of polish of the upper white ground – the treatment, which should result in the same thickness of the ground on all places of the uneven surface. The origin of Madonna of Sedes sapientiae type can be assigned to workshops drawing on Western-European traditions.
Keywords:
madonna Sedes sapientiae; 12th century; siliceous ground; radiocarbon dating 14c
Available at various institutes of the ASCR
Newly Found romanesque madonna of Sedes sapientiae type coming from a czech private collection with elements of west european fine arts tradition
On the basis of material research, the oldest preserved polychrome carving of Madonna of Sedes sapientiae type was dated using radiocarbon method 14C to the interval of 990 – 1180. During the ...
Limitations of spectroscopic methods in the study of earthy pigments
Košařová, V.; Hradil, David; Kanický, V.
2012 - English
Nowadays, the spectroscopic methods, above all Infrared Spectroscopy (IR), are the most frequently used analytical methods in the research of cultural heritage, which is mainly caused by easy use and non-invasiveness of these methods and a broad range of their application, which comprises both organic and inorganic substances. Nevertheless, each analytical technique has its detection limits, and the fact that a particular method is suitable for one type of a sample does not automatically mean that it will be appropriate for the identification of another sample. Therefore, the aim of the study is to demonstrate the limitations of both Raman Spectroscopy (RS) and infrared spectroscopy in the study of earthy materials.
Keywords:
Raman spectroscopy; infrared spectroscopy; earthy pigment; clay minerals
Available at various institutes of the ASCR
Limitations of spectroscopic methods in the study of earthy pigments
Nowadays, the spectroscopic methods, above all Infrared Spectroscopy (IR), are the most frequently used analytical methods in the research of cultural heritage, which is mainly caused by easy use and ...
Preparation of nanoforms of layered piezoelectric of systems BI2O3-TA(2)O(5)-AO (A=CA,SR,BA)
Štarman, S.; Matz, V.; Kváča, Z.; Mohyla, M.; Olšák, V.; Plocek, Jiří; Vaněk, Přemysl; Tylš, B.
2011 - English
Based on the known Aurivillius phases types ABi2Ta2O9 and A2BiTaO6 ( A=Ca, Sr, Ba) were supplemented with new compositions of layered tantalates, which resulted the possibility of the existence of a new phase Sr2BiTaO6. Ternary compounds with piezoelectric structure were prepared as nanoforms by solgel reactions of homogeneous acetate Bi, Ta, A and subsequent annealing in a controlled atmosphere. Annealing temperature was determined from DSC curves based on the weight loss and phase transitions. Composition and structure of nanocrystals has been analyzed by X-ray diffraction (XRD), scanning nanomorphology (SEM) and acoustic measurements.
Keywords:
tantalates; piezoelectricity; solgel; acoustic; measurement
Available at various institutes of the ASCR
Preparation of nanoforms of layered piezoelectric of systems BI2O3-TA(2)O(5)-AO (A=CA,SR,BA)
Based on the known Aurivillius phases types ABi2Ta2O9 and A2BiTaO6 ( A=Ca, Sr, Ba) were supplemented with new compositions of layered tantalates, which resulted the possibility of the existence of a ...
Amperometric Solid-State NO2 Sensor with Ionic Liquid-Polymer Electrolyte
Nádherná, M.; Opekar, F.; Reiter, Jakub
2011 - English
A new ionic liquid-polymer electrolyte was successfully tested in the planar amperometric solid-state sensor sensitive towards nitrogen dioxide. The electrolyte consists of 1-butyl-3-methylimidazolium hexafluorophosphate (BMIPF6) and poly(ethylene glycol) methyl ether methacrylate (PEGMEMA) in the ratio 57:43 mol. %. The analyte, gaseous nitrogen dioxide in air, was determined using the electrochemical reduction at900 mV vs. Pt/air on gold minigrid indicating electrode with Pt/air as a reference electrode. Dependency of sensor sensitivity on the indicating electrode area and relative humidity was determined. The sensor response is linear in the NO2 concentration range 0.3 1.1 ppm and is reproducible and long-term stable.
Keywords:
Sensor; Ionic Liquid; Nitrogen Dioxide; Gold Minigrid
Available at various institutes of the ASCR
Amperometric Solid-State NO2 Sensor with Ionic Liquid-Polymer Electrolyte
A new ionic liquid-polymer electrolyte was successfully tested in the planar amperometric solid-state sensor sensitive towards nitrogen dioxide. The electrolyte consists of 1-butyl-3-methylimidazolium ...
Energy sensitive X-ray radiography for the non-destructive inspection of historical paintings
Žemlička, J.; Jakůbek, J.; Hradil, David; Hradilová, J.; Kroupa, M.; Mislerová, H.
2010 - English
The technical composition of painted artworks is usually very complex and they belong to the most sophisticated cultural heritage artefacts. In the field of their inspection there is a rising demand for the non-destructive imaging and analytical methods which are able to reveal the inner composition of investigated objects. Several non-invasive methods based on the interaction of ionizing radiation with the matter have been successfully utilized during the last decades. These methods can be divided into two main groups. The better known are transmission methods (e.g. classical X-ray radiography) the less-used are emission methods (e.g. X-ray fluorescence imaging). The quality of the obtained image is highly dependent on the imaging characteristics of the used detector. The presently used ones (CCD cameras and CMOS sensors) create the image from analogue signal by the charge integration. This image is usually degraded by the presence of noise. This complication is exceeded by novel pixel detectors of Medipix family based on single particle digital counting. Furthermore these devices offer very high contrast (in principle unlimited) in the obtained image. The image can be acquired with spatial resolution better than one micrometer. Another advantage of these detectors is their ability to directly measure the energy of incident particles. This feature can be used for energy sensitive X-ray radiography (i.e. multi-channel images) and X-ray fluorescence mapping of the surface elemental composition. For the purposes of this work the laboratory ALMA in Prague prepared several multilayer samples of paints using different pigments. The results of mentioned methods applied on the test samples are summarized in this article. The first goal of these measurements is to build a comprehensive methodology for the application of these procedures in the laboratory.
Keywords:
Pixel detector; X-ray transmission radiography; X-ray fluorescence imaging; Painted arts pigment analysis
Available at various institutes of the ASCR
Energy sensitive X-ray radiography for the non-destructive inspection of historical paintings
The technical composition of painted artworks is usually very complex and they belong to the most sophisticated cultural heritage artefacts. In the field of their inspection there is a rising demand ...
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