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Author Broers, F.T.H.; Verslype, I.; Bossers, K.W.; Vanmeert, F.; Gonzalez, V.; Garrevoet, J.; van Loon, A.; va Duijn, E.; Krekeler, A.; De Keyser, N.; Steeman, I.; Noble, P.; Janssens, K.; Meirer, F.; Keune, K. url  doi
openurl 
  Title Correlated x-ray fluorescence and ptychographic nano-tomography on Rembrandt's The Night Watch reveals unknown lead “layer” Type A1 Journal article
  Year 2023 Publication Science Advances Abbreviated Journal (up)  
  Volume 9 Issue 50 Pages eadj9394-13  
  Keywords A1 Journal article; Engineering sciences. Technology; Art; Antwerp X-ray Imaging and Spectroscopy (AXIS)  
  Abstract The Night Watch, one of the most famous masterpieces by Rembrandt, is the subject of a large research and conservation project. For the conservation treatment, it is of great importance to understand its current condition. Correlated nano-tomography using x-ray fluorescence and ptychography revealed a-so far unknown-lead-containing “layer”, which likely acts as a protective impregnation layer applied on the canvas before the quartz-clay ground was applied. This layer might explain the presence of lead soap protrusions in areas where no other lead components are present. In addition to the three-dimensional elemental mapping, ptychography visualizes and quantifies components not detectable by hard x-ray fluorescence such as the organic fraction and quartz. The first-time use of this combination of synchrotron-based techniques on a historic paint micro-sample shows it to be an important tool to better interpret the results of noninvasive imaging techniques operating on the macroscale.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 001142514700010 Publication Date 2023-12-15  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 2375-2548 ISBN Additional Links UA library record; WoS full record  
  Impact Factor Times cited Open Access  
  Notes Approved no  
  Call Number UA @ admin @ c:irua:203849 Serial 9016  
Permanent link to this record
 

 
Author Koirala, B.; Rasti, B.; Bnoulkacem, Z.; De Lima Ribeiro, A.; Madriz, Y.; Herrmann, E.; Gestels, A.; De Kerf, T.; Janssens, K.; Steenackers, G.; Gloaguen, R.; Scheunders, P. pdf  doi
openurl 
  Title An extensive multisensor hyperspectral benchmark datasets of intimate mixtures of mineral powders Type P1 Proceeding
  Year 2023 Publication Abbreviated Journal (up)  
  Volume Issue Pages 5890-5893 T2 - IGARSS 2023 - 2023 IEEE Internation  
  Keywords P1 Proceeding; Vision lab; Antwerp X-ray Imaging and Spectroscopy (AXIS)  
  Abstract Since many materials behave as heterogeneous intimate mixtures with which each photon interacts differently, the relationship between spectral reflectance and material composition is very complex. Quantitative validation of spectral unmixing algorithms requires high-quality ground truth fractional abundance data, which are very difficult to obtain.In this work, we generated a comprehensive hyperspectral dataset of intimate mineral powder mixtures by homogeneously mixing five different clay powders (Kaolin, Roof clay, Red clay, mixed clay, and Calcium hydroxide). In total 325 samples were prepared. Among the 325 samples, 60 mixtures were binary, 150 were ternary, 100 were quaternary, and 15 were quinary. For each mixture (and pure clay powder), reflectance spectra are acquired by 13 different sensors, with a broad wavelength range between the visible and the long-wavelength infrared regions (i.e., between 350 nm and 15385 nm) and with a large variation in sensor types, platforms, and acquisition conditions. We will make this dataset public, to be used by the community for the validation of nonlinear unmixing methodologies (https://github.com/VisionlabUA/Multisensor_datasets)  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos Publication Date 2023-10-20  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 979-83-503-2010-7 ISBN Additional Links UA library record  
  Impact Factor Times cited Open Access  
  Notes Approved no  
  Call Number UA @ admin @ c:irua:201596 Serial 9035  
Permanent link to this record
 

 
Author Koirala, B.; Rasti, B.; Bnoulkacem, Z.; de Lima Ribeiro, A.; Madriz, Y.; Herrmann, E.; Gestels, A.; De Kerf, T.; Lorenz, S.; Fuchs, M.; Janssens, K.; Steenackers, G.; Gloaguen, R.; Scheunders, P. pdf  doi
openurl 
  Title A multisensor hyperspectral benchmark dataset for unmixing of intimate mixtures Type A1 Journal article
  Year 2024 Publication IEEE sensors journal Abbreviated Journal (up)  
  Volume 24 Issue 4 Pages 4694-4710  
  Keywords A1 Journal article; Engineering sciences. Technology; Vision lab; Antwerp X-ray Imaging and Spectroscopy (AXIS)  
  Abstract Optical hyperspectral cameras capture the spectral reflectance of materials. Since many materials behave as heterogeneous intimate mixtures with which each photon interacts differently, the relationship between spectral reflectance and material composition is very complex. Quantitative validation of spectral unmixing algorithms requires high-quality ground truth fractional abundance data, which are very difficult to obtain. In this work, we generated a comprehensive laboratory ground truth dataset of intimately mixed mineral powders. For this, five clay powders (Kaolin, Roof clay, Red clay, mixed clay, and Calcium hydroxide) were mixed homogeneously to prepare 325 samples of 60 binary, 150 ternary, 100 quaternary, and 15 quinary mixtures. Thirteen different hyperspectral sensors have been used to acquire the reflectance spectra of these mixtures in the visible, near, short, mid, and long-wavelength infrared regions (350-15385) nm. Overlaps in wavelength regions due to the operational ranges of each sensor and variations in acquisition conditions resulted in a large amount of spectral variability. Ground truth composition is given by construction, but to verify that the generated samples are sufficiently homogeneous, XRD and XRF elemental analysis is performed. We believe these data will be beneficial for validating advanced methods for nonlinear unmixing and material composition estimation, including studying spectral variability and training supervised unmixing approaches. The datasets can be downloaded from the following link: https://github.com/VisionlabHyperspectral/Multisensor_datasets.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos Publication Date 2023-12-28  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1530-437x; 1558-1748 ISBN Additional Links UA library record  
  Impact Factor Times cited Open Access Not_Open_Access  
  Notes Approved no  
  Call Number UA @ admin @ c:irua:203094 Serial 9059  
Permanent link to this record
 

 
Author Derks, K.; Youchaeva, M.; Van der Snickt, G.; Van der Stighelen, K.; Janssens, K. url  openurl
  Title Reconstructing Sweerts : practical insights into the historical dark halo technique based on paint reconstructions Type P1 Proceeding
  Year 2024 Publication Abbreviated Journal (up)  
  Volume Issue Pages 259-271 T2 - Alla maniera : technical art history  
  Keywords P1 Proceeding; Engineering sciences. Technology; Art; Antwerp Cultural Heritage Sciences (ARCHES); Antwerp X-ray Imaging and Spectroscopy (AXIS)  
  Abstract  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos Publication Date  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 978-90-429-5216-4 ISBN Additional Links UA library record  
  Impact Factor Times cited Open Access  
  Notes Approved no  
  Call Number UA @ admin @ c:irua:203062 Serial 9082  
Permanent link to this record
 

 
Author Janssens, K.; Bogaerts, A.; van Grieken, R. openurl 
  Title Colloquium Spectroscopicum Internationale 34: a collection of papers presented at the Colloquium Spectroscopicum Internationale, Antwerp, Belgium, 4-9 September 2005 Type ME3 Book as editor
  Year 2006 Publication Abbreviated Journal (up)  
  Volume Issue Pages  
  Keywords ME3 Book as editor; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation); Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)  
  Abstract  
  Address  
  Corporate Author Thesis  
  Publisher Elsevier Place of Publication Amsterdam Editor  
  Language Wos Publication Date 0000-00-00  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN ISBN Additional Links UA library record  
  Impact Factor Times cited Open Access  
  Notes Approved Most recent IF: NA  
  Call Number UA @ lucian @ c:irua:61092 Serial 391  
Permanent link to this record
 

 
Author Bogaerts, A.; Janssens, K.; van Grieken, R. openurl 
  Title Colloquium Spectroscopicum Internationale 34 (CSI 34), Antwerp, Belgium, 4-9 September 2005 Type ME3 Book as editor
  Year 2006 Publication Abbreviated Journal (up)  
  Volume Issue Pages  
  Keywords ME3 Book as editor; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation); Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)  
  Abstract  
  Address  
  Corporate Author Thesis  
  Publisher Elsevier Place of Publication Amsterdam Editor  
  Language Wos Publication Date 0000-00-00  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN ISBN Additional Links UA library record  
  Impact Factor Times cited Open Access  
  Notes Approved Most recent IF: NA  
  Call Number UA @ lucian @ c:irua:58858 Serial 394  
Permanent link to this record
 

 
Author Caen, J.; Schalm, O.; van der Snickt, G.; van der Linden, V.; Frederickx, P.; Schryvers, D.; Janssens, K.; Cornelis, E.; van Dyck, D.; Schreiner, M. openurl 
  Title Enamels in stained-glass windows : preparation, chemical composition, microstructure and causes of deterioration Type P3 Proceeding
  Year 2005 Publication Abbreviated Journal (up)  
  Volume Issue Pages 121-126  
  Keywords P3 Proceeding; Art; Electron microscopy for materials research (EMAT); AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation); Vision lab  
  Abstract  
  Address  
  Corporate Author Thesis  
  Publisher Glassac Place of Publication Lisbon Editor  
  Language Wos Publication Date 0000-00-00  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN ISBN Additional Links UA library record  
  Impact Factor Times cited Open Access  
  Notes Approved Most recent IF: NA  
  Call Number UA @ lucian @ c:irua:112025 Serial 1036  
Permanent link to this record
 

 
Author Peeters, F.M.; Janssens, K.L.; Partoens, B. openurl 
  Title Excitons in single and vertically coupled type II quantum dots in high magnetic fields Type H1 Book chapter
  Year 2003 Publication Abbreviated Journal (up)  
  Volume Issue Pages 117  
  Keywords H1 Book chapter; Condensed Matter Theory (CMT)  
  Abstract  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication s.l. Editor  
  Language Wos Publication Date 0000-00-00  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN ISBN Additional Links UA library record; WoS full record;  
  Impact Factor Times cited Open Access  
  Notes Approved Most recent IF: NA  
  Call Number UA @ lucian @ c:irua:62451 Serial 1129  
Permanent link to this record
 

 
Author Peeters, F.M.; Tadić, M.; Janssens, K.L.; Partoens, B. openurl 
  Title Hole band engineering in self-assembled quantum dots and molecules Type H1 Book chapter
  Year 2004 Publication Abbreviated Journal (up)  
  Volume Issue Pages 191-202  
  Keywords H1 Book chapter; Condensed Matter Theory (CMT)  
  Abstract  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication s.l. Editor  
  Language Wos Publication Date 0000-00-00  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN ISBN Additional Links UA library record; WoS full record;  
  Impact Factor Times cited Open Access  
  Notes Approved Most recent IF: NA  
  Call Number UA @ lucian @ c:irua:62454 Serial 1475  
Permanent link to this record
 

 
Author Janssens, K.L.; Partoens, B.; Peeters, F.M. openurl 
  Title Single and coupled type II quantum dots in magnetic and electric fields Type A1 Journal article
  Year 2002 Publication Physicalia magazine Abbreviated Journal (up)  
  Volume 24 Issue Pages 211  
  Keywords A1 Journal article; Condensed Matter Theory (CMT)  
  Abstract  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Gent Editor  
  Language Wos Publication Date 0000-00-00  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0770-0520 ISBN Additional Links UA library record  
  Impact Factor Times cited Open Access  
  Notes Approved Most recent IF: NA  
  Call Number UA @ lucian @ c:irua:62456 Serial 3016  
Permanent link to this record
 

 
Author Gonzalez, V.; Fazlic, I.; Cotte, M.; Vanmeert, F.; Gestels, A.; De Meyer, S.; Broers, F.; Hermans, J.; van Loon, A.; Janssens, K.; Noble, P.; Keune, K. url  doi
openurl 
  Title Lead(II) formate in Rembrandt's Night Watch : detection and distribution from the macro- to the micro-scale Type A1 Journal article
  Year 2023 Publication Angewandte Chemie: international edition in English Abbreviated Journal (up)  
  Volume Issue Pages 1-9  
  Keywords A1 Journal article; Art; Antwerp X-ray Imaging and Spectroscopy (AXIS)  
  Abstract The Night Watch, painted in 1642 and on view in the Rijksmuseum in Amsterdam, is considered Rembrandt's most famous work. X-ray powder diffraction (XRPD) mapping at multiple length scales revealed the unusual presence of lead(II) formate, Pb(HCOO)(2), in several areas of the painting. Until now, this compound was never reported in historical oil paints. In order to get insights into this phenomenon, one possible chemical pathway was explored thanks to the preparation and micro-analysis of model oil paint media prepared by heating linseed oil and lead(II) oxide (PbO) drier as described in 17(th) century recipes. Synchrotron radiation based micro-XRPD (SR-mu-XRPD) and infrared microscopy were combined to identify and map at the micro-scale various neo-formed lead-based compounds in these model samples. Both lead(II) formate and lead(II) formate hydroxide Pb(HCOO)(OH) were detected and mapped, providing new clues regarding the reactivity of lead driers in oil matrices in historical paintings.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000920584500001 Publication Date 2023-01-02  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1433-7851; 0570-0833 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 16.6 Times cited Open Access OpenAccess  
  Notes Approved Most recent IF: 16.6; 2023 IF: 11.994  
  Call Number UA @ admin @ c:irua:194279 Serial 7318  
Permanent link to this record
 

 
Author Byrnes, I.; Rossbach, L.M.; Jaroszewicz, J.; Grolimund, D.; Sanchez, D.F.; Gomez-Gonzalez, M.A.; Nuyts, G.; Reinoso-Maset, E.; Janssens, K.; Salbu, B.; Brede, D.A.; Lind, O.C. url  doi
openurl 
  Title Synchrotron XRF and histological analyses identify damage to digestive tract of uranium NP-exposed Daphnia magna Type A1 Journal article
  Year 2023 Publication Environmental science and technology Abbreviated Journal (up)  
  Volume 57 Issue 2 Pages 1071-1079  
  Keywords A1 Journal article; Antwerp X-ray Imaging and Spectroscopy (AXIS)  
  Abstract Micro-and nanoscopic X-ray techniques were used to investigate the relationship between uranium (U) tissue distributions and adverse effects to the digestive tract of aquatic model organism Daphnia magna following uranium nanoparticle (UNP) exposure. X-ray absorption computed tomography measure-ments of intact daphnids exposed to sublethal concentrations of UNPs or a U reference solution (URef) showed adverse morphological changes to the midgut and the hepatic ceca. Histological analyses of exposed organisms revealed a high proportion of abnormal and irregularly shaped intestinal epithelial cells. Disruption of the hepatic ceca and midgut epithelial tissues implied digestive functions and intestinal barriers were compro-mised. Synchrotron-based micro X-ray fluorescence (XRF) elemental mapping identified U co-localized with morphological changes, with substantial accumulation of U in the lumen as well as in the epithelial tissues. Utilizing high-resolution nano-XRF, 400-1000 nm sized U particulates could be identified throughout the midgut and within hepatic ceca cells, coinciding with tissue damages. The results highlight disruption of intestinal function as an important mode of action of acute U toxicity in D. magna and that midgut epithelial cells as well as the hepatic ceca are key target organs.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000910915100001 Publication Date 2023-01-04  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0013-936x; 1520-5851 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 11.4 Times cited Open Access OpenAccess  
  Notes Approved Most recent IF: 11.4; 2023 IF: 6.198  
  Call Number UA @ admin @ c:irua:193478 Serial 7342  
Permanent link to this record
 

 
Author Byrnes, I.; Rossbach, L.M.; Brede, D.A.; Grolimund, D.; Sanchez, D.F.; Nuyts, G.; Cuba, V.; Reinoso-Maset, E.; Salbu, B.; Janssens, K.; Oughton, D.; Scheibener, S.; Teien, H.-C.; Lind, O.C. url  doi
openurl 
  Title Synchrotron-based X-ray fluorescence imaging elucidates uranium toxicokinetics in Daphnia magna Type A1 Journal article
  Year 2023 Publication ACS nano Abbreviated Journal (up)  
  Volume 17 Issue 6 Pages 5296-5305  
  Keywords A1 Journal article; Engineering sciences. Technology; Antwerp X-ray Imaging and Spectroscopy (AXIS)  
  Abstract A combination of synchrotron-based elemental anal-ysis and acute toxicity tests was used to investigate the biodistribution and adverse effects in Daphnia magna exposed to uranium nanoparticle (UNP, 3-5 nm) suspensions or to uranium reference (Uref) solutions. Speciation analysis revealed similar size distributions between exposures, and toxicity tests showed com-parable acute effects (UNP LC50: 402 mu g L-1 [336-484], Uref LC50: 268 mu g L-1 [229-315]). However, the uranium body burden was 3 -to 5-fold greater in UNP-exposed daphnids, and analysis of survival as a function of body burden revealed a similar to 5-fold higher specific toxicity from the Uref exposure. High-resolution X-ray fluorescence elemental maps of intact, whole daphnids from sublethal, acute exposures of both treatments revealed high uranium accumulation onto the gills (epipodites) as well as within the hepatic ceca and the intestinal lumen. Uranium uptake into the hemolymph circulatory system was inferred from signals observed in organs such as the heart and the maxillary gland. The substantial uptake in the maxillary gland and the associated nephridium suggests that these organs play a role in uranium removal from the hemolymph and subsequent excretion. Uranium was also observed associated with the embryos and the remnants of the chorion, suggesting uptake in the offspring. The identification of target organs and tissues is of major importance to the understanding of uranium and UNP toxicity and exposure characterization that should ultimately contribute to reducing uncertainties in related environmental impact and risk assessments.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000960129800001 Publication Date 2023-03-15  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1936-0851 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 17.1 Times cited Open Access OpenAccess  
  Notes Approved Most recent IF: 17.1; 2023 IF: 13.942  
  Call Number UA @ admin @ c:irua:196061 Serial 8631  
Permanent link to this record
 

 
Author Janssens, K.; Vincze, L.; Vekemans, B.; Aerts, A.; Adams, F.; Jones, K.W.; Knöchel, A. openurl 
  Title Synchrotron radiation induced X-ray microfluorescence analysis Type A1 Journal article
  Year 1996 Publication Microchimica acta T2 – 4th Workshop of the European-Microanalysis-Society on Modern, Developments and Applications in Microbeam Analysis, MAY, 1995, ST MALO, FRANCE Abbreviated Journal (up) 4th Workshop of the European-Microanalysis-Society on Modern, Developments and Applications in Micro  
  Volume Issue s:[13] Pages 87-115  
  Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)  
  Abstract mu-XRF is the microscopic equivalent of the well-established multielement analytical technique. In this paper, after comparing the interaction of X-ray photons, electrons and protons with matter and an introduction to synchrotron rings and microfocussing of X-rays, the instrumentation for mu-XRF is discussed, both for laboratory source and synchrotron based setups and the analytical characteristics of mu-XRF are contrasted to that of other microanalytical techniques, Also, this issue of quantification of mu-XRF data is addressed; the applicability of the method in archeological and geological analysis is illustrated.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos A1996VT82300006 Publication Date  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor Times cited Open Access  
  Notes Approved no  
  Call Number UA @ admin @ c:irua:104410 Serial 5866  
Permanent link to this record
 

 
Author Janssens, K.; Vekemans, B.; Adams, F.; van Espen, P.; Mutsaers, P. doi  openurl
  Title Accurate evaluation of \mu-PIXE and \mu-XRF spectral data through iterative least squares fitting Type A1 Journal article
  Year 1996 Publication Nuclear instruments and methods in physics research: B: beam interactions with materials and atoms T2 – 7th International Conference on Particle Induced X-ray Emission and Its Analytical Applications, MAY 26-30, 1995, Abano Terme, Italy Abbreviated Journal (up) 7th International Conference on Particle Induced X-ray Emission and Its Analytical Applications, MAY  
  Volume 109 Issue Pages 179-185  
  Keywords A1 Journal article; Engineering sciences. Technology; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation); Chemometrics (Mitac 3)  
  Abstract The integration of the nonlinear least squares X-ray spectrum evaluation progam AXIL. into a mu-PIXE and a mu-XRF setup is discussed. The use of the software when procesing data sets derived from biological and geological samples is described.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos A1996UV44400035 Publication Date 2002-07-25  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0168-583x ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor Times cited Open Access  
  Notes Approved no  
  Call Number UA @ admin @ c:irua:95887 Serial 5457  
Permanent link to this record
 

 
Author Janssens, K.; Dik, J.; Cotte, M.; Susini, J. doi  openurl
  Title Photon-based techniques for nondestructive subsurface analysis of painted cultural heritage artifacts Type A1 Journal article
  Year 2010 Publication Accounts of chemical research Abbreviated Journal (up) Accounts Chem Res  
  Volume 43 Issue 6 Pages 814-825  
  Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)  
  Abstract Often, just micrometers below a paintings surface lies a wealth of information, both with Old Masters such as Peter Paul Rubens and Rembrandt van Rijn and with more recent artists of great renown such as Vincent Van Gogh and James Ensor. Subsurface layers may include underdrawing, underpainting, and alterations, and in a growing number of cases conservators have discovered abandoned compositions on paintings, illustrating artists practice of reusing a canvas or panel. The standard methods for studying the inner structure of cultural heritage (CH) artifacts are infrared reflectography and X-ray radiography, techniques that are optionally complemented with the microscopic analysis of cross-sectioned samples. These methods have limitations, but recently, a number of fundamentally new approaches for fully imaging the buildup of hidden paint layers and other complex three-dimensional (3D) substructures have been put into practice. In this Account, we discuss these developments and their recent practical application with CH artifacts. We begin with a tabular summary of 14 IR- and X-ray-based imaging methods and then continue with a discussion of each technique, illustrating CH applications with specific case studies. X-ray-based tomographic and laminographic techniques can be used to generate 3D renditions of artifacts of varying dimensions. These methods are proving invaluable for exploring inner structures, identifying the conservation state, and postulating the original manufacturing technology of metallic and other sculptures. In the analysis of paint layers, terahertz time-domain spectroscopy (THz-TDS) can highlight interfaces between layers in a stratigraphic buildup, whereas macrosopic scanning X-ray fluorescence (MA-XRF) has been employed to measure the distribution of pigments within these layers. This combination of innovative methods provides topographic and color information about the micrometer depth scale, allowing us to look into paintings in an entirely new manner. Over the past five years, several new variants of traditional IR- and X-ray-based imaging methods have been implemented by conservators and museums, and the first reports have begun to emerge in the primary research literature. Applying these state-of-the-art techniques in a complementary fashion affords a more comprehensive view of paintings and other artworks.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000278842500013 Publication Date 2010-05-12  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0001-4842 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 20.268 Times cited 78 Open Access  
  Notes ; This research was supported by the Interuniversity Attraction Poles Programme-Belgian Science Policy (IUAP VI/16). The text also presents results of FWO (Brussels, Belgium) projects nr. G.0704.08 and G.0179.09 and from the UA-BOF GOA programme. ; Approved Most recent IF: 20.268; 2010 IF: 21.852  
  Call Number UA @ admin @ c:irua:83983 Serial 5772  
Permanent link to this record
 

 
Author Cotte, M.; Susini, J.; Dik, J.; Janssens, K. doi  openurl
  Title Synchrotron-based X-ray absorption spectroscopy for art conservation: looking back and looking forward Type A1 Journal article
  Year 2010 Publication Accounts of chemical research Abbreviated Journal (up) Accounts Chem Res  
  Volume 43 Issue 6 Pages 705-714  
  Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)  
  Abstract A variety of analytical techniques augmented by the use of synchrotron radiation (SR), such as X-ray fluorescence (SR-XRF) and X-ray diffraction (SR-XRD), are now readily available, and they differ little, conceptually, from their common laboratory counterparts. Because of numerous advantages afforded by SR-based techniques over benchtop versions, however, SR methods have become popular with archaeologists, art historians, curators, and other researchers in the field of cultural heritage (CH). Although the CH community now commonly uses both SR-XRF and SR-XRD, the use of synchrotron-based X-ray absorption spectroscopy (SR-XAS) techniques remains marginal, mostly because CH specialists rarely interact with SR physicists. In this Account, we examine the basic principles and capabilities of XAS techniques in art preservation. XAS techniques offer a combination of features particularly well-suited for the chemical analysis of works of art. The methods are noninvasive, have low detection limits, afford high lateral resolution, and provide exceptional chemical sensitivity. These characteristics are highly desirable for the chemical characterization of precious, heterogeneous, and complex materials. In particular, the chemical mapping capability, with high spatial resolution that provides information about local composition and chemical states, even for trace elements, is a unique asset. The chemistry involved in both the objects history (that is, during fabrication) and future (that is, during preservation and restoration treatments) can be addressed by XAS. On the one hand, many studies seek to explain optical effects occurring in historical glasses or ceramics by probing the molecular environment of relevant chromophores. Hence, XAS can provide insight into craft skills that were mastered years, decades, or centuries ago but were lost over the course of time. On the other hand, XAS can also be used to characterize unwanted reactions, which are then considered alteration phenomena and can dramatically alter the objects original visual properties. In such cases, the bulk elemental composition is usually unchanged. Hence, monitoring oxidation state (or, more generally, other chemical modifications) can be of great importance. Recent applications of XAS in art conservation are reviewed and new trends are discussed, highlighting the value (and future possibilities) of XAS, which remains, given its potential, underutilized in the CH community.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000278842500003 Publication Date 2010-01-08  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0001-4842 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 20.268 Times cited 74 Open Access  
  Notes ; ; Approved Most recent IF: 20.268; 2010 IF: 21.852  
  Call Number UA @ admin @ c:irua:83982 Serial 5861  
Permanent link to this record
 

 
Author Benito, P.; de Nolf, W.; Nuyts, G.; Janssens, K.; et al. pdf  url
doi  openurl
  Title Role of coating-metallic support interaction in the properties of electrosynthesized Rh-based structured catalysts Type A1 Journal article
  Year 2014 Publication ACS catalysis Abbreviated Journal (up) Acs Catal  
  Volume 4 Issue 10 Pages 3779-3790  
  Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)  
  Abstract Rh-structured catalysts for the catalytic partial oxidation of CH4 to syngas were prepared by electrosynthesis of Rh-containing hydrotalcite-type (HT) compounds on FeCrAlloy foams followed by calcination at 900 degrees C. During the calcination the simultaneous decomposition of the layered HT structure and formation of the protective FeCrAlloy outer shell in alumina occurred. Here, we studied the role of the coating-metallic support interaction in the properties of the catalysts after calcination, H-2 reduction, and catalytic tests, by a combination of electron (FEG-SEM/EDS) and synchrotron X-ray (XRF/XRPD and XRF/XANES) microscopic techniques. The characterization of crystalline phases in the metallic support and coating and distribution of Rh active species was carried out on several samples prepared by modifying the Rh content in the electrolytic solution (Rh/Mg/Al = 11.0/70.0/19.0, 5.0/70.0/25.0, 0/70.0/30.0 atomic ratio). A sample was also prepared with no aluminum in the electrolytic solution (Rh/Mg/Al = 13.6/86.4/0.0 atomic ratio) and calcined at 550 and 900 degrees C. The interaction between the elements of the metallic support and the catalytic coating increased the film adhesion during the thermal treatment and catalytic tests and modified the catalyst crystalline phases. A chemical reaction between Al corning from the foam and Mg in the coating occurred during calcination at high temperature leading to the formation of spinel phases in which rhodium is solved, together with some Rh2O3 and Rh. The metallic support was oxidized forming the corundum scale and chromium oxides, moreover t-Al2O3 was identified. For the Rh11.0Mg70.0Al19.0 catalyst the inclusion of Rh in the spinel phase decreased its reducibility in the H-2 pretreatment. The reduction continued during catalytic tests by feeding diluted CH4/O-2/He gas mixtures, evidenced by the catalyst activation. While under concentrated gas mixtures the deactivation occurred, probably by oxidation.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000345735200053 Publication Date 2014-09-24  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 2155-5435 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 10.614 Times cited 13 Open Access  
  Notes ; The authors thank the scientists who assisted during the conducted experiments: D. Grolimund and C. N. Borca for the mu XRF/XRPD experiments performed at MicroXAS Beamline of SLS, M. Janousch for the mu XRF/XANES experiments at Phoenix Beamline of the SLS, M. Salome for the mu XRE/XANES experiments at ID21 Beamline of the ESRF, and I. Guerra for the FEG-SEM/EDS experiments at Granada University. Thanks must go to Porvair for supplying FeCrAlloy foams. The financial support from the Ministero per l'Istruzione, l'Universita e la Ricerca (MIUR, Roma, I) is gratefully acknowledged. ; Approved Most recent IF: 10.614; 2014 IF: 9.312  
  Call Number UA @ admin @ c:irua:122215 Serial 5820  
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Author Basile, F.; Benito, P.; Bugani, S.; de Nolf, W.; Fornasari, G.; Janssens, K.; Morselli, L.; Scavetta, E.; Tonelli, D.; Vaccari, A. doi  openurl
  Title Combined use of synchrotron-radiation-based imaging techniques for the characterization of structured catalysts Type A1 Journal article
  Year 2010 Publication Advanced functional materials Abbreviated Journal (up) Adv Funct Mater  
  Volume 20 Issue 23 Pages 4117-4126  
  Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)  
  Abstract Active-phase-coated metallic supports as structured catalysts are gaining attention in endothermic and exothermic processes because they improve heat transfer. The deposition of a well-adhered and stable catalyst layer on the metallic support constitutes an important feature for the successful application of the final material. In this work, coating of FeCrAlY foams is performed by a one-step electrosynthesis-deposition of hydrotalcite-type compounds, precursors of catalysts active in endothermic steam methane reforming. The catalysts are studied at different length scales by using, for the first time, a combination of several techniques: SEM/EDS and X-ray fluorescence, X-ray powder diffraction and absorption-tomography experiments on the micro- and nanoscales at a synchrotron facility. The results show that the morphology of the coating depends on the synthesis conditions and that the catalyst may be described as Ni metal crystallites dispersed on γ-Al2O3, homogeneously coating the FeCrAlY foam.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000285392900010 Publication Date 2010-09-23  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1616-301x ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 12.124 Times cited 24 Open Access  
  Notes ; The authors give thanks to Dr. Cloetens, for helping during the absorption tomography experiments, performed at ID19 of the ESRF; and P. Blauet and R. Toucolou, for helping during the mu-XRF/XRPD and nano-XRF experiments at ID22 and ID22-NI of the ESRF. The financial support from the Ministero per l'Istruzione, l'Universita e la Ricerca (MIUR, Roma, Italy) is gratefully acknowledged. ; Approved Most recent IF: 12.124; 2010 IF: 8.508  
  Call Number UA @ admin @ c:irua:85834 Serial 5525  
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Author Jaroszewicz, J.; de Nolf, W.; Janssens, K.; Michalski, A.; Falkenberg, G. doi  openurl
  Title Advantages of combined mu-XRF and mu-XRD for phase characterization of Ti-B-C ceramics compared with conventional X-ray diffraction Type A1 Journal article
  Year 2008 Publication Analytical and bioanalytical chemistry Abbreviated Journal (up) Anal Bioanal Chem  
  Volume 391 Issue 4 Pages 1129-1133  
  Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)  
  Abstract  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000256088700005 Publication Date 2008-05-05  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1618-2642 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 3.431 Times cited 7 Open Access  
  Notes Approved Most recent IF: 3.431; 2008 IF: 3.328  
  Call Number UA @ admin @ c:irua:69317 Serial 5459  
Permanent link to this record
 

 
Author Cagno, S.; Janssens, K.; Mendera, M. doi  openurl
  Title Compositional analysis of Tuscan glass samples: in search of raw materials fingerprints Type A1 Journal article
  Year 2008 Publication Analytical and bioanalytical chemistry Abbreviated Journal (up) Anal Bioanal Chem  
  Volume 391 Issue 4 Pages 1389-1395  
  Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)  
  Abstract  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000256088700035 Publication Date 2008-02-25  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1618-2642 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 3.431 Times cited 26 Open Access  
  Notes Approved Most recent IF: 3.431; 2008 IF: 3.328  
  Call Number UA @ admin @ c:irua:69320 Serial 5545  
Permanent link to this record
 

 
Author Janssens, K.; van Espen, P.; Van 't dack, L. doi  openurl
  Title Euroanalysis 14: the European Conference on Analytical Chemistry Type Editorial
  Year 2008 Publication Analytical and bioanalytical chemistry Abbreviated Journal (up) Anal Bioanal Chem  
  Volume 391 Issue 4 Pages 1107-1108  
  Keywords Editorial; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation); Chemometrics (Mitac 3)  
  Abstract  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000256088700001 Publication Date 2008-05-05  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1618-2642 ISBN Additional Links UA library record; WoS full record  
  Impact Factor 3.431 Times cited Open Access  
  Notes Approved Most recent IF: 3.431; 2008 IF: 3.328  
  Call Number UA @ admin @ c:irua:69316 Serial 5608  
Permanent link to this record
 

 
Author Bugani, S.; Camaiti, M.; Morselli, L.; Van de Casteele, E.; Janssens, K. doi  openurl
  Title Investigating morphological changes in treated vs. untreated stone building materials by x-ray micro-CT Type A1 Journal article
  Year 2008 Publication Analytical and bioanalytical chemistry Abbreviated Journal (up) Anal Bioanal Chem  
  Volume 391 Issue 4 Pages 1343-1350  
  Keywords A1 Journal article; Vision lab; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)  
  Abstract  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000256088700030 Publication Date 2008-03-14  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1618-2642 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 3.431 Times cited 25 Open Access  
  Notes Approved Most recent IF: 3.431; 2008 IF: 3.328  
  Call Number UA @ admin @ c:irua:69319 Serial 5673  
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Author Terzano, R.; Alfeld, M.; Janssens, K.; Vekemans, B.; Schoonjans, T.; Vincze, L.; Tomasi, N.; Pinton, R.; Cesco, S. pdf  doi
openurl 
  Title Spatially resolved (semi)quantitative determination of iron (Fe) in plants by means of synchrotron micro X-ray fluorescence Type A1 Journal article
  Year 2013 Publication Analytical and bioanalytical chemistry Abbreviated Journal (up) Anal Bioanal Chem  
  Volume 405 Issue 10 Pages 3341-3350  
  Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)  
  Abstract Iron (Fe) is an essential element for plant growth and development; hence determining Fe distribution and concentration inside plant organs at the microscopic level is of great relevance to better understand its metabolism and bioavailability through the food chain. Among the available microanalytical techniques, synchrotron mu-XRF methods can provide a powerful and versatile array of analytical tools to study Fe distribution within plant samples. In the last years, the implementation of new algorithms and detection technologies has opened the way to more accurate (semi)quantitative analyses of complex matrices like plant materials. In this paper, for the first time the distribution of Fe within tomato roots has been imaged and quantified by means of confocal mu-XRF and exploiting a recently developed fundamental parameter-based algorithm. With this approach, Fe concentrations ranging from few hundreds of ppb to several hundreds of ppm can be determined at the microscopic level without cutting sections. Furthermore, Fe (semi)quantitative distribution maps were obtained for the first time by using two opposing detectors to collect simultaneously the XRF radiation emerging from both sides of an intact cucumber leaf.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000316338700033 Publication Date 2013-02-07  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1618-2642 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 3.431 Times cited 27 Open Access  
  Notes ; Research was supported by grants from Italian MIUR (FIRB-Programma “Futuro in Ricerca”) and Free University of Bolzano (TN5046 and TN5056). Synchrotron experiments at HASY-LAB were financially supported by the European Community Research Infrastructure Action under the FP6 “Structuring the European Research Area” Program I (Integrating Activity on Synchrotron and Free Electron Laser Science; project: contract RII3-CT-2004-506008). Matthias Alfeld receives a Ph.D. fellowship of the Research Foundation-Flanders (FWO). We thank Karen Rickers-Appel for her scientific and technical support in obtaining the experimental data at Beamline L (HASYLAB, DESY, Hamburg, Germany). ; Approved Most recent IF: 3.431; 2013 IF: 3.578  
  Call Number UA @ admin @ c:irua:108261 Serial 5838  
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Author Bugani, S.; Modugno, F.; Lucejko, J.J.; Giachi, G.; Cagno, S.; Cloetens, P.; Janssens, K.; Morselli, L. pdf  doi
openurl 
  Title Study on the impregnation of archaeological waterlogged wood with consolidation treatments using synchrotron radiation microtomography Type A1 Journal article
  Year 2009 Publication Analytical and bioanalytical chemistry Abbreviated Journal (up) Anal Bioanal Chem  
  Volume 395 Issue 7 Pages 1977-1985  
  Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)  
  Abstract In favourable conditions of low temperature and low oxygen concentration, archaeological waterlogged wooden artefacts, such as shipwrecks, can survive with a good state of preservation. Nevertheless, anaerobic bacteria can considerably degrade waterlogged wooden objects with a significant loss in polysaccharidic components. Due to these decay processes, wood porosity and water content increase under ageing. In such conditions, the conservation treatments of archaeological wooden artefacts often involve the replacement of water with substances which fill the cavities and help to prevent collapse and stress during drying. The treatments are very often expensive and technically difficult, and their effectiveness very much depends on the chemical and physical characteristics of the substances used for impregnation. Also important are the degree of cavity-filling, penetration depth and distribution in the structure of the wood. In this study, the distribution in wood cavities of some mixtures based on polyethylene glycols and colophony, used for the conservation of waterlogged archaeological wood, was investigated using synchrotron radiation X-ray computed microtomography (SR-A mu CT). This non-destructive imaging technique was useful for the study of the degraded waterlogged wood and enabled us to visualise the morphology of the wood and the distribution of the materials used in the wood treatments. The study has shown how deposition is strictly related to the dimension of the wooden cavities. The work is currently proceeding with the comparison of synchrotron observations with the data of the solutions viscosity and with those of the properties imparted to the wood by the treatments.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000272017000005 Publication Date 2009-09-16  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1618-2642 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 3.431 Times cited 30 Open Access  
  Notes Approved Most recent IF: 3.431; 2009 IF: 3.480  
  Call Number UA @ admin @ c:irua:94493 Serial 5853  
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Author Monico, L.; Janssens, K.; Miliani, C.; Brunetti, B.G.; Vagnini, M.; Vanmeert, F.; Falkenberg, G.; Abakumov, A.; Lu, Y.; Tian, H.; Verbeeck, J.; Radepont, M.; Cotte, M.; Hendriks, E.; Geldof, M.; van der Loeff, L.; Salvant, J.; Menu, M.; pdf  doi
openurl 
  Title Degradation process of lead chromate in paintings by Vincent van Gogh studied by means of spectromicroscopic methods : 3 : synthesis, characterization, and detection of different crystal forms of the chrome yellow pigment Type A1 Journal article
  Year 2013 Publication Analytical chemistry Abbreviated Journal (up) Anal Chem  
  Volume 85 Issue 2 Pages 860-867  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT); AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)  
  Abstract The painter, Vincent van Gogh, and some of his contemporaries frequently made use of the pigment chrome yellow that is known to show a tendency toward darkening. This pigment may correspond to various chemical compounds such as PbCrO4 and PbCr1-xSxO4, that may each be present in various crystallographic forms with different tendencies toward degradation. Investigations by X-ray diffraction (XRD), mid-Fourier Transform infrared (FTIR), and Raman instruments (benchtop and portable) and synchrotron radiation-based micro-XRD and X-ray absorption near edge structure spectroscopy performed on oil-paint models, prepared with in-house synthesized PbCrO4 and PbCr1-xSxO4, permitted us to characterize the spectroscopic features of the various forms. On the basis of these results, an extended study has been carried out on historic paint tubes and on embedded paint microsamples taken from yellow-orange/pale yellow areas of 12 Van Gogh paintings, demonstrating that Van Gogh effectively made use of different chrome yellow types. This conclusion was also confirmed by in situ mid-FTIR investigations on Van Goghs Portrait of Gauguin (Van Gogh Museum, Amsterdam).  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Washington, D.C. Editor  
  Language Wos 000313668400031 Publication Date 2012-10-10  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0003-2700;1520-6882; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 6.32 Times cited 79 Open Access  
  Notes Goa; Fwo Approved Most recent IF: 6.32; 2013 IF: 5.825  
  Call Number UA @ lucian @ c:irua:108707UA @ admin @ c:irua:108707 Serial 631  
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Author Monico, L.; van der Snickt, G.; Janssens, K.; de Nolf, W.; Miliani, C.; Verbeeck, J.; Tian, H.; Tan, H.; Dik, J.; Radepont, M.; Cotte, M. pdf  doi
openurl 
  Title Degradation process of lead chromate in paintings by Vincent van Gogh studied by means of synchrotron X-ray spectromicroscopy and related methods : 1 : artificially aged model samples Type A1 Journal article
  Year 2011 Publication Analytical chemistry Abbreviated Journal (up) Anal Chem  
  Volume 83 Issue 4 Pages 1214-1223  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT); AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)  
  Abstract On several paintings by artists of the end of the 19th century and the beginning of the 20th Century a darkening of the original yellow areas, painted with the chrome yellow pigment (PbCrO4, PbCrO4·xPbSO4, or PbCrO4·xPbO) is observed. The most famous of these are the various Sunflowers paintings Vincent van Gogh made during his career. In the first part of this work, we attempt to elucidate the degradation process of chrome yellow by studying artificially aged model samples. In view of the very thin (1−3 μm) alteration layers that are formed, high lateral resolution spectroscopic methods such as microscopic X-ray absorption near edge (μ-XANES), X-ray fluorescence spectrometry (μ-XRF), and electron energy loss spectrometry (EELS) were employed. Some of these use synchrotron radiation (SR). Additionally, microscopic SR X-ray diffraction (SR μ-XRD), μ-Raman, and mid-FTIR spectroscopy were employed to completely characterize the samples. The formation of Cr(III) compounds at the surface of the chrome yellow paint layers is particularly observed in one aged model sample taken from a historic paint tube (ca. 1914). About two-thirds of the chromium that is present at the surface has reduced from the hexavalent to the trivalent state. The EELS and μ-XANES spectra are consistent with the presence of Cr2O3·2H2O (viridian). Moreover, as demonstrated by μ-XANES, the presence of another Cr(III) compound, such as either Cr2(SO4)3·H2O or (CH3CO2)7Cr3(OH)2 [chromium(III) acetate hydroxide], is likely.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Washington, D.C. Editor  
  Language Wos 000287176900011 Publication Date 2011-02-14  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0003-2700;1520-6882; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 6.32 Times cited 113 Open Access  
  Notes Iuap; Fwo Approved Most recent IF: 6.32; 2011 IF: 5.856  
  Call Number UA @ lucian @ c:irua:88794UA @ admin @ c:irua:88794 Serial 632  
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Author Rahemi, V.; Sarmadian, N.; Anaf, W.; Janssens, K.; Lamoen, D.; Partoens, B.; De Wael, K. pdf  url
doi  openurl
  Title Unique opto-electronic structure and photo reduction properties of sulfur doped lead chromates explaining their instability in paintings Type A1 Journal article
  Year 2017 Publication Analytical chemistry Abbreviated Journal (up) Anal Chem  
  Volume 89 Issue 89 Pages 3326-3334  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT); AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)  
  Abstract Chrome yellow refers to a group of synthetic inorganic pigments that became popular as an artists material from the second quarter of the 19th century. The color of the pigment, in which the chromate ion acts as a chromophore, is related to its chemical composition (PbCr1-xSxO4, with 0≤x≤0.8) and crystalline structure (monoclinic/orthorhombic). Their shades range from the yellow-orange to the paler yellow tones with increasing sulfate amount. These pigments show remarkable signs of degradation after limited time periods. Pure PbCrO4 (crocoite in its natural form) has a deep yellow color and is relatively stable, while the co-precipitate with lead sulfate (PbCr1-xSxO4) has a paler shade and seems to degrade faster. This degradation is assumed to be related to the reduction of Cr(VI) to Cr(III). We show that on increasing the sulfur(S)-content in chrome yellow, the band gap increases. Typically, when increasing the band gap, one might assume that a decrease in photo activity is the result. However, the photo activity relative to the Cr content, and thus Cr reduction, of sulfur-rich PbCr1-xSxO4 is found to be much higher compared to the sulfur-poor or non-doped lead chromates. This discrepancy can be explained by the evolution of the crystal and electronic structure as function of the sulfur content: first-principles density functional theory calculations show that both the absorption coefficient and reflection coefficients of the lead chromates change as a result of the sulfate doping in such a way that the generation of electron-hole pairs under illumination relative to the total Cr content increases. These changes in the material properties explain why paler shade yellow colors of this pigment are more prone to discoloration. The electronic structure calculations also demonstrate that lead chromate and its co-precipitates are p-type semiconductors, which explains the observed reduction reaction. As understanding this phenomenon is valuable in the field of cultural heritage, this study is the first joint action of photo-electrochemical measurements and first-principles calculations to approve the higher tendency of sulfur-rich lead chromates to darken.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Washington, D.C. Editor  
  Language Wos 000397478300015 Publication Date 2017-02-23  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0003-2700 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 6.32 Times cited 7 Open Access OpenAccess  
  Notes ; The computational resources and services used in this work were provided by the VSC (Flemish Supercomputer Center) and the HPC infrastructure of the University of Antwerp (CalcUA), both funded by the Hercules Foundation and the Flemish Government, department EWI. The BOF-GOA action SOLARPAINT of the University of Antwerp Research Council is acknowledged for financial support. W.A. acknowledges support from BELSPO project S2-ART. Dr. L. Monico and Dr. C. Miliani (ISTM, Perugia) are gratefully acknowledged for helpful discussions and for providing some of the initial batches of the materials studied. ; Approved Most recent IF: 6.32  
  Call Number UA @ lucian @ c:irua:140886 Serial 4451  
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Author van der Snickt, G.; Dik, J.; Cotte, M.; Janssens, K.; Jaroszewicz, J.; de Nolf, W.; Groenewegen, J.; van der Loeff, L. doi  openurl
  Title Characterization of a degraded cadmium yellow (CdS) pigment in an oil painting by means of synchrotron radiation based X-ray techniques Type A1 Journal article
  Year 2009 Publication Analytical chemistry Abbreviated Journal (up) Anal Chem  
  Volume 81 Issue 7 Pages 2600-2610  
  Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)  
  Abstract On several paintings of James Ensor (1860−1949), a gradual fading of originally bright yellow areas, painted with the pigment cadmium yellow (CdS), is observed. Additionally, in some areas exposed to light, the formation of small white-colored globules on top of the original paint surface is observed. In this paper the chemical transformation leading to the color change and to the formation of the globules is elucidated. Microscopic X-ray absorption near-edge spectroscopy (ì-XANES) experiments show that sulfur, originally present in sulfidic form (S2−), is oxidized during the transformation to the sulfate form (S6+). Upon formation (at or immediately below the surface), the highly soluble cadmium sulfate is assumed to be transported to the surface in solution and reprecipitates there, forming the whitish globules. The presence of cadmium sulfate (CdSO4·2H2O) and ammonium cadmium sulfate [(NH4)2Cd(SO4)2] at the surface is confirmed by microscopic X-ray diffraction measurements, where the latter salt is suspected to result from a secondary reaction of cadmium sulfate with ammonia. Measurements performed on cross sections reveal that the oxidation front has penetrated into the yellow paint down to ca. 1−2 ìm. The morphology and elemental distribution of the paint and degradation product were examined by means of scanning electron microscopy equipped with an energy-dispersive spectrometer (SEM-EDS) and synchrotron radiation based micro-X-ray fluorescence spectrometry (SR ì-XRF). In addition, ultraviolet-induced visible fluorescence photography (UIVFP) revealed itself to be a straightforward technique for documenting the occurrence of this specific kind of degradation on a macroscale by painting conservators.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000264759400025 Publication Date 2009-03-11  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0003-2700; 5206-882x ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 6.32 Times cited 91 Open Access  
  Notes Approved Most recent IF: 6.32; 2009 IF: 5.214  
  Call Number UA @ admin @ c:irua:76415 Serial 5501  
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Author Cagno, S.; Brede, D.A.; Nuyts, G.; Vanmeert, F.; Pacureanu, A.; Tucoulou, R.; Cloetens, P.; Falkenberg, G.; Janssens, K.; Salbu, B.; Lind, O.C. url  doi
openurl 
  Title Combined computed nanotomography and nanoscopic x-ray fluorescence imaging of cobalt nanoparticles in caenorhabditis elegans Type A1 Journal article
  Year 2017 Publication Analytical chemistry Abbreviated Journal (up) Anal Chem  
  Volume 89 Issue 21 Pages 11435-11442  
  Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)  
  Abstract Synchrotron radiation phase-contrast computed nanotomography (nano-CT) and two-and three-dimensional (2D and 3D) nanoscopic X-ray fluorescence (nano-XRF) were used to investigate the internal distribution of engineered-cobalt nanoparticles (Co NPs) in exposed individuals of the nematode Caenorhabditis elegans. Whole-nematodes and selected tissues and organs were 3D-rendered: anatomical 3D renderings with 50 nm voxel size enabled the visualization of spherical nanoparticle aggregates. with size tip to 200 nm within intact C. elegans. A 20 X 37 nm(2) high-brilliance beam was employed to obtain XRF elemental distribution maps of entire nematodes or anatomical details such as embryos, which could be compared with the CT data, These maps showed Co NPs to be predominantly present within the intestine and the epithelium, and they were not colocalized with Zn granules found in the lysosonie-containing vesicles or Fe agglomerates in the intestine. Iterated XRF scanning of a specimen at 0 degrees and 90 degrees angles suggested that NP aggregates were translocated into tissues outside of the intestinal lumen. Virtual-slicing by means of 2D XRF tomography, combined with holotomography, indicated presumable presence of individual NP aggregates inside the uterus and within embryos.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000414887000041 Publication Date 2017-10-10  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0003-2700; 5206-882x ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 6.32 Times cited 13 Open Access  
  Notes ; This study has been funded by the Norwegian Research Council through its Centre of Excellence (CoE) funding scheme (Project 223268/F50). We gratefully acknowledge ESRF and DESY for granting beamtime and Karl Andreas Jensen for performing ICPMS analysis. We thank Erica Maremonti for supplying the phase-contrast image used in Figure ^1A. ; Approved Most recent IF: 6.32  
  Call Number UA @ admin @ c:irua:147383 Serial 5520  
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