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Author |
Alvarez-Martin, A.; Janssens, K. |
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Title |
Protecting and stimulating effect on the degradation of eosin lakes. Part 1 : lead white and cobalt blue |
Type |
A1 Journal article |
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Year |
2018 |
Publication |
Microchemical journal |
Abbreviated Journal |
Microchem J |
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Volume |
141 |
Issue |
141 |
Pages |
51-63 |
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Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
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Abstract |
An important problem encountered during the preservation of paintings and other artworks is the fading of the original colors due to exposure of the colorants to light. This fact is clearly evidenced in some of Vincent Van Gogh's paintings in which an organic red, eosin or geranium lake, is present. The identification of eosin and the characterization of its degradation products in paintings represents a challenge because of (i) the generally low concentration of the pigment remaining after an aging period of ca 100 years, (ii) the scarcity of the paint micro samples available for analysis and the difficulty of obtaining additional ones and (iii) the complexity of the degradation behavior of eosin when it is mixed with organic or inorganic pigments, binding media or varnish. This study presents an accelerated aging experiment of eosin paint models in order to understand better the discoloration process; more specifically the influence of different metals with which eosin forms complexes and of the presence of admixture pigments such as lead white and cobalt blue on the lightfastness of eosin is evaluated. Paint model samples were prepared using eosin, lead white, and cobalt blue in different mixing ratios and were characterized with several techniques before and after aging. The possible formation of intermediate molecular forms during the aging experiment and the influence of pigment ratios on the discoloration process were monitored at periodic intervals using a combination of LTV Visible and attenuated total Reflectance-Fourier transform infrared (ATR-FTIR) spectroscopies. Raman spectroscopy, scanning electron microscopy coupled to energy-dispersive X-ray analysis (SEM-EDX) and optical microscopy (OM) analyses were performed to gain information about the discoloration processes taking place within the paint models. Eosin precipitated on lead, aluminum and potassium/aluminum salts was used. These three lakes showed similar discoloration rates under light exposure. In contrast, the presence and relative abundance of the admixture pigments lead white and cobalt blue had a significant influence on the (speed of the) eosin discoloration process. The presence of lead white and cobalt blue appears to stimulate the eosin degradation. However, the cobalt blue shows less influence in the discoloration process, showing a protective effect during the first stages of the aging. This may be qualitatively explained in terms of the ability of lead white to scatter light towards eosin molecules and the absorption characteristics of cobalt blue in the green range of the electromagnetic spectrum, shielding eosin from incoming light. The color changes observed in the paint reconstructions are similar to discoloration phenomena visible in some Van Gogh paintings and can offer an explanation of the gradual discoloration process that took place over the years. These insights will be helpful to estimate the original hues color used/intended by the artist. |
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Wos |
000439678200006 |
Publication Date |
2018-05-07 |
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ISSN |
0026-265x; 0026-265x |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
3.034 |
Times cited |
3 |
Open Access |
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Notes |
; The authors sincerely acknowledged Dr. Costanza Miliani for sharing information about the synthesis of geranium lake. The authors also acknowledged Dr. Geert van der Snickt and Gert Nuyts for the help with the aging experiments and for carrying out the SEM-EDX measurements respectively. The authors would like to acknowledge the SolarPaint project (GOA programme, Antwerp University Research Council) for financial support. ; |
Approved  |
Most recent IF: 3.034 |
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Call Number |
UA @ admin @ c:irua:153087 |
Serial |
5788 |
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Author |
Janssens, K.; van der Snickt, G.; Alfeld, M.; Noble, P.; van Loon, A.; Delaney, J.; Conover, D.; Zeibel, J.; Dik, J. |
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Title |
Rembrandt's 'Saul and David' (c. 1652) : use of multiple types of smalt evidenced by means of non-destructive imaging |
Type |
A1 Journal article |
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Year |
2016 |
Publication |
Microchemical journal |
Abbreviated Journal |
Microchem J |
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Volume |
126 |
Issue |
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Pages |
515-523 |
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Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
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Abstract |
The painting Saul and David, considered to date from c. 1652 and previously attributed to Rembrandt van Rijn and/or his studio, is a complex work of art that has been recently subjected to intensive investigation and conservation treatment. The goal of the research was to give insight into the painting's physical construction and condition in preparation for conservation treatment. It was also anticipated that analysis would shed light on authenticity questions and Rembrandt's role in the creation of the painting. The painting depicts the Old Testament figures of King Saul and David. At left is Saul, seated, holding a spear and wiping a tear from his eye with a curtain. David kneels before him at the right playing his harp. In the past, the large sections with the life-size figures were cut apart and later reassembled. A third piece of canvas was added to replace a missing piece of canvas above the head of David. As part of the investigation into the authenticity of the curtain area, a number of paint micro samples were examined with LM and SEM-EDX. Given that the earth, smalt and lake pigments used in the painting could not be imaged with traditional imaging techniques, the entire painting was also examined with state of the art non-destructive imaging techniques. Special attention was devoted to the presence of cobalt-containing materials, specifically the blue glass pigment smalt considered characteristic for the late Rembrandt. A combination of quantitative electron microprobe analysis and macroscopic X-ray fluorescence scanning revealed that three types of cobalt-containing materials are present in the painting. The first type is a cobalt drier that was found in the overpaint used to cover up the canvas inset and the joins that were added in the 19th century. The other two Co-containing materials are part of the original paint used by Rembrandt and comprise two varieties of smalt, a K-rich glass pigment that derives its gray-blue color by doping with Co-ions. Smalt paint with a higher Ni content (NiO:CoO ratio of around 1:4) was used to depict the blue stripes in Saul's colorful turban, while smalt with a lower Ni content was employed (NiO:CoO ratio of around 1:5) for the broad expanses of Saul's garments. The presence of two types of smalt not only supports the recent re-attribution of the painting to Rembrandt, but also that the picture was painted in two phases. Saul's dark red garment is painted in a rough, “loose” manner and the now discolored smalt-rich layer was found to have been partially removed during a past restoration treatment/s. In contrast, the blue-green smalt in the turban is much better preserved and provides a colorful accent. While the use of different types of smalt in a Rembrandt painting has been previously identified using quantitative EDX analysis of paint cross-sections, to the best of our knowledge this is the first time such a distinction has been observed in a 17th-century painting using non-destructive imaging techniques. In addition to the XRF-based non-invasive elemental mapping, hyperspectral imaging in the visual to near-infrared (VNIR) region was also carried out. (C) 2016 Elsevier B.V. All rights reserved. |
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Wos |
000373647500063 |
Publication Date |
2016-01-29 |
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ISSN |
0026-265x; 0026-265x |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
3.034 |
Times cited |
18 |
Open Access |
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Notes |
; This research is part of the ReVisualising late Rembrandt: Developing and Applying New Imaging Techniques research project, supported by the Science4Arts research program of the Netherlands Organisation for Scientific Research (NWO, The Hague, NL, ReVisRembrandt project) and the National Science Foundation (NSF, Washington DC, USA, award 1041827). We would like to thank colleagues of the Mauritshuis (The Hague, NL) and the Dutch Cultural Heritage Agency (RCE) in Rijswijk, NL for their support and assistance during the scanning of the Saul and David painting. The GOA project “SOLARPAINT” (University of Antwerp) and the Fund Baillet Latour (Brussels, B) are acknowledged for financial support to GvdS and KJ. We also like to acknowledge the help of Eliza Longhini and Stijn Legrand during some of the XRF scanning stages. ; |
Approved |
Most recent IF: 3.034 |
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Call Number |
UA @ admin @ c:irua:133258 |
Serial |
5813 |
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Author |
Alfeld, M.; Wahabzada, M.; Bauckhage, C.; Kersting, K.; van der Snickt, G.; Noble, P.; Janssens, K.; Wellenreuther, G.; Falkenberg, G. |
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Title |
Simplex Volume Maximization (SiVM): a matrix factorization algorithm with non-negative constrains and low computing demands for the interpretation of full spectral X-ray fluorescence imaging data |
Type |
A1 Journal article |
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Year |
2017 |
Publication |
Microchemical journal |
Abbreviated Journal |
Microchem J |
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Volume |
132 |
Issue |
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Pages |
179-184 |
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Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
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Abstract |
Technological progress allows for an ever-faster acquisition of hyperspectral data, challenging the users to keep up with interpreting the recorded data. Matrix factorization, the representation of data sets by bases (or loads) and coefficient (or score) images is long used to support the interpretation of complex data sets. We propose in this publication Simplex Volume Maximization (SiVM) for the analysis of X-ray fluorescence (XRF) imaging data sets. SiVM selects archetypical data points that represents the data set and thus provides easily understandable bases, preserves the non-negative character of XRF data sets and has low demands concerning computing resources. We apply SiVM on an XRF data set of Hans Memling's Portrait of a man from the Lespinette family from the collection of the Mauritshuis (The Hague, NL) and discuss capabilities and shortcomings of SiVM. (C) 2017 Elsevier B.V. All rights reserved. |
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Wos |
000399845700026 |
Publication Date |
2017-02-04 |
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ISSN |
0026-265x; 0026-265x |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
3.034 |
Times cited |
8 |
Open Access |
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Notes |
; The German Federal Ministry of Education and Research (BMBF) is acknowledged for the financial support (Verbundprojekt 05K2012 POISSON: Fortschrittliche Faktorenanalyse ffir Poisson-verteilte Daten). ; |
Approved |
Most recent IF: 3.034 |
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Call Number |
UA @ admin @ c:irua:152647 |
Serial |
5830 |
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Author |
Alvarez-Martin, A.; Kavich, G. |
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Title |
SPME-GC–MS for the off-gassing analysis of a complex museum object |
Type |
A1 Journal article |
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Year |
2021 |
Publication |
Microchemical Journal |
Abbreviated Journal |
Microchem J |
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Volume |
167 |
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Pages |
106276 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation); Antwerp X-ray Imaging and Spectroscopy (AXIS) |
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Abstract |
The identification of volatile organic compounds (VOCs) emitted by a complex museum object, composed of materials of different nature, has been optimized by solid-phase microextraction coupled to gas chromatography-mass spectrometry (SPME-GC–MS). The performance of two fiber coatings and four sampling times were tested and compared in order to define the best sampling conditions. The method allowed a fair extraction of volatile and semivolatile compounds emitted naturally by the object, without any type of accelerating aging. In addition, on-fiber derivatization was applied to improve the extraction efficiency and reduce the sampling time of harmful carboxylic acids emitted by the object. The results obtained are of prime importance to show the off-gassing activity of a valuable museum object in order to take further decisions related with its storage and display conditions. |
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Wos |
000662640500001 |
Publication Date |
2021-04-21 |
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Edition |
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ISSN |
0026-265x; 0026-265x |
ISBN |
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Additional Links |
UA library record; WoS full record |
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Impact Factor |
3.034 |
Times cited |
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Open Access |
Not_Open_Access |
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Notes |
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Approved |
Most recent IF: 3.034 |
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Call Number |
UA @ admin @ c:irua:181924 |
Serial |
8577 |
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