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Alfeld M.,University of Antwerp | De Nolf W.,University of Antwerp | Cagno S.,University of Antwerp | Appel K.,German Electron Synchrotron | And 7 more authors.
Journal of Analytical Atomic Spectrometry | Year: 2013

Over the past several decades the oeuvre of Rembrandt has been the subject of extensive art historical and scientific investigations. One of the most striking features to emerge is his frequent re-use of canvases and panels. The painting An Old Man in Military Costume (78.PB.246), in the collection of the J. Paul Getty Museum, is an example of such a re-used panel. Conventional imaging techniques revealed the presence of a second portrait under the surface portrait, but the details of this hidden portrait have not yet been revealed. Vermilion (HgS) has been identified to have been used nearly exclusively in the flesh tones of the lower painting, suggesting that element-specific XRF imaging might successfully image the hidden portrait. To test this hypothesis, a full-scale mock-up of the painting was created, including a "free impression" of the hidden portrait, reproducing as closely as possible the pigments and paint stratigraphy of the original painting. XRF imaging of the mock-up painting was conducted using three different XRF imaging systems: a mobile X-ray tube based system and two synchrotron-based setups (one equipped with multiple SDDs and one equipped with a Maia detector). The sensitivity, limits of detection and imaging capabilities of each system under the chosen experimental conditions are evaluated and compared. The results indicate that an investigation of the original painting by this method would have an excellent chance of success. This journal is © 2013 The Royal Society of Chemistry. Source


Grayburn R.A.,University of Warwick | Grayburn R.A.,Ghent University | Grayburn R.A.,200 Getty Center Drive | Dowsett M.G.,University of Warwick | And 10 more authors.
Bioelectrochemistry | Year: 2016

The objective of this work is to study the initial corrosion of copper in the presence of gold when placed in simulated uterine fluid in order to better understand the evolution of active components of copper-IUDs. In order to carry out this study, a portable cell was designed to partially simulate the uterine environment and provide a way of tracking the chemical changes occurring in the samples in situ within a controlled environment over a long period of time using synchrotron spectroelectrochemistry. The dynamically forming crystalline corrosion products are determined in situ for a range of copper-gold surface ratios over the course of a 10-day experiment in the cell. It is concluded that the insoluble deposits forming over this time are not the origin of the anticonception mechanism. © 2016 Elsevier B.V. Source


Bradley L.P.,200 Getty Center Drive | Meloni S.,Royal Picture Gallery Mauritshuis Mauritshuis | Uffelman E.S.,Washington and Lee University | Mass J.L.,Scientific Research and Analysis Laboratory
ACS Symposium Series | Year: 2012

Gijsbert Gillisz d'Hondecoeter's (1604-1653) panel painting, Cock and Hens in a Landscape, recently underwent complete treatment and technical examination at The Royal Picture Gallery Mauritshuis, The Hague (inv. no. 405). The interdisciplinary application of art historical research, conservation methodology, and scientific investigation led to several discoveries about the painting, including the revelation that major compositional elements of iconographical significance had been overpainted at some point in its history. Technical examination suggested that the original paint was in sufficiently good condition for the overpaint to be removed. The painting is currently on permanent display at the Prince William V Gallery in a state closer to the painter's original artistic intent. © 2012 American Chemical Society. Source


Walton M.,Northwestern University | Trentelman K.,Getty Conservation Institute | Cianchetta I.,Getty Conservation Institute | Maish J.,200 Getty Center Drive | And 3 more authors.
Journal of the American Ceramic Society | Year: 2014

The black-colored pottery slips produced in Athens from the 6th to 4th centuries B.C.; had a consistent composition achieved through processing and refinement of raw clay. Little direct evidence has been established as to what were these refinement methods. To better understand how the slip material was prepared, the major and trace elemental compositions of 19 slips from different ceramic vessels and their corresponding bodies of Athenian red-figure and black-figure vases were determined using laser ablation inductively coupled plasma mass spectrometry (LA-ICPMS). Notably higher Zn concentrations were found in the slips (271-1959 ppm) than in their corresponding body ceramics (<361 ppm). The Zn concentrations in the slips were also found to be above the natural background for typical clay (between 10 and 300 ppm) suggesting an unintentional anthropogenic enrichment of this metal. Based on the abnormally high Zn content of the slip, it is speculated that the clay was treated using vitriol (concentrated acid mine runoff which is rich in Zn), to induce flocculation and remove carbonate mineral phases from the raw material that, if present, would prevent the slip from vitrifying. This same signature of elevated levels of Zn with a corresponding Ce anomaly is also observed for black glosses produced in Corinthian and Etrurian (Italy) workshops indicating that these trace element signatures were imparted to the material by means of shared methods of manufacturing instead of being indicative of a single unique source for this material. © 2014 The American Ceramic Society. Source


Mass J.,Winterthur Museum | Sedlmair J.,University of Wisconsin - Madison | Patterson C.S.,200 Getty Center Drive | Carson D.,200 Getty Center Drive | And 2 more authors.
Analyst | Year: 2013

SR-FTIR imaging has been used to map the mid-IR active photo-degradation phases in two thin sections of cadmium yellow paint removed from Henri Matisse's Le Bonheur de vivre (1905-1906, The Barnes Foundation). These samples represent both the darkened cadmium yellow foliage in the upper left of the work and the lightened cadmium yellow field beneath the central reclining figures. The altered cadmium yellow paints from both regions were found to contain cadmium carbonate (CdCO3), cadmium sulphate (CdSO4), and cadmium oxalate (CdC2O4). Each of these phases was imaged to determine their positions as a function of depth, with the aim of better understanding the role of each phase in the degradation mechanism. This speciation mapping is critical because cadmium oxalate was used in this period as an additive in cadmium yellow light. In addition, cadmium carbonate and cadmium sulphate were synthesis starting materials for cadmium yellow, and so their distribution throughout the paint layer can provide an indication of their roles. It was established that cadmium oxalate is localized at the surface of the paint layer, cadmium carbonate is found deeper in the layer but still enriched at the surface, and cadmium sulphate is distributed throughout the layer. This distribution, along with the chloride content of the paint suggesting a cadmium chloride starting material, is consistent with an alteration mechanism in which the cadmium sulphide is oxidized to sulphate and this is then converted to carbonate and oxalate. The relative solubilities of the three photo-degradation products are also relevant to their locations in the paint film. © 2013 The Royal Society of Chemistry. Source

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