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Author Vanmeert, F.; de Nolf, W.; Dik, J.; Janssens, K. url  doi
openurl 
  Title Macroscopic X-ray powder diffraction scanning : possibilities for quantitative and depth-selective parchment analysis Type A1 Journal article
  Year 2018 Publication Analytical chemistry Abbreviated Journal Anal Chem  
  Volume 90 Issue 11 Pages 6445-6452  
  Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)  
  Abstract At or below the surface of painted works of art, valuable information is present that provides insights into an objects past, such as the artists technique and the creative process that was followed or its conservation history but also on its current state of preservation. Various noninvasive techniques have been developed over the past 2 decades that can probe this information either locally (via point analysis) or on a macroscopic scale (e.g., full-field imaging and raster scanning). Recently macroscopic X-ray powder diffraction (MA-XRPD) mapping using laboratory X-ray sources was developed. This method can visualize highly specific chemical distributions at the macroscale (dm(2)). In this work we demonstrate the synergy between the quantitative aspects of powder diffraction and the noninvasive scanning capability of MA-XRPD highlighting the potential of the method to reveal new types of information. Quantitative data derived from a 15th/16th century illuminated sheet of parchment revealed three lead white pigments with different hydrocerussite-cerussite compositions in specific pictorial elements, while quantification analysis of impurities in the blue azurite pigment revealed two distinct azurite types: one rich in barite and one in quartz. Furthermore, on the same artifact, the depth-selective possibilities of the method that stem from an exploitation of the shift of the measured diffraction peaks with respect to reference data are highlighted. The influence of different experimental parameters on the depth-selective analysis results is briefly discussed. Promising stratigraphic information could be obtained, even though the analysis is hampered by not completely understood variations in the unit cell dimensions of the crystalline pigment phases.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000434893200020 Publication Date 2018-04-06  
  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 (up) 6 Open Access  
  Notes ; The authors thank Incoatec GmbH for giving us the opportunity to test the I mu S Cu X-ray source. We acknowledge financial support from BELSPO (Brussels) S2-ART, the NWO (The Hague) Science4Arts “ReVisRembrandt” project, and GOA Project Solarpaint (University of Antwerp Research Council). Photo Copyright Geert Van der Snickt, 2008 for the photograph of the illuminated manuscript in the TOC graphic. ; Approved Most recent IF: 6.32  
  Call Number UA @ admin @ c:irua:151994 Serial 5702  
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Author Vincze, L.; Kukhlevsky, S.V.; Janssens, K. doi  openurl
  Title Simulation of poly-capillary lenses for coherent and partially coherent x-rays Type P1 Proceeding
  Year 2004 Publication Proceedings of the Society of Photo-optical Instrumentation Engineers T2 – Conference on Advances in Computational Methods for X-Ray and Neutron, Optics, AUG 03-05, 2004, Denver, CO Abbreviated Journal  
  Volume Issue Pages 81-85  
  Keywords P1 Proceeding; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)  
  Abstract The intensity distributions of the coherent and partially coherent x-rays passed through a poly-capillary lens have been computed at the focal plane. The computations showed that at the appropriate experimental conditions the interference phenomenon does affect the intensity distribution. In the case of the coherent input radiation with the photon energy of 0.1 keV, the interference fringes were observed, while the non-coherent x-ray radiation produced no interference-like intensity distributions.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000225564800008 Publication Date 2004-11-05  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume 5536 Series Issue Edition  
  ISSN 0-8194-5474-5 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor Times cited (up) 6 Open Access  
  Notes Approved Most recent IF: NA  
  Call Number UA @ admin @ c:irua:103753 Serial 5832  
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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 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 (up) 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 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 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 (up) 7 Open Access  
  Notes Approved Most recent IF: 3.431; 2008 IF: 3.328  
  Call Number UA @ admin @ c:irua:69317 Serial 5459  
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Author Kukhlevsky, S.V.; Mechler, M.; Samek, O.; Janssens, K. doi  openurl
  Title Analytical model of the enhanced light transmission through subwavelength metal slits: Green's function formalism versus Rayleigh's expansion Type A1 Journal article
  Year 2006 Publication Applied physics B : lasers and optics Abbreviated Journal Appl Phys B-Lasers O  
  Volume 84 Issue 1/2 Pages 19-24  
  Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)  
  Abstract  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000238828700004 Publication Date 2006-05-30  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0946-2171 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 1.696 Times cited (up) 7 Open Access  
  Notes Approved Most recent IF: 1.696; 2006 IF: 2.023  
  Call Number UA @ admin @ c:irua:59635 Serial 5472  
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Author Vermeulen, M.; Saverwyns, S.; Coudray, A.; Janssens, K.; Sanyova, J. pdf  doi
openurl 
  Title Identification by Raman spectroscopy of pararealgar as a starting material in the synthesis of amorphous arsenic sulfide pigments Type A1 Journal article
  Year 2018 Publication Dyes and pigments Abbreviated Journal Dyes Pigments  
  Volume 149 Issue 149 Pages 290-297  
  Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)  
  Abstract In this study, a combination of elemental analytical techniques (MA-XRF and SEM-EDX) were used to localize arsenic sulfide pigments within a 17th-century Dutch painting and in the stratigraphy of an 18th-century Flemish polychrome sculpture. Once located, Raman spectroscopy was used to obtain the vibrational signature of the arsenic sulfide pigments employed. By means of the latter analytical technique and due to the very distinctive Raman scattering signal of the various arsenic sulfide compounds, it was possible to identify the arsenic-based pigments as natural orpiment and amorphous arsenic sulfide. In the latter case, based on the minor bands observed and the good condition of the paint layers, it was possible to identify pararealgar, the orangey-yellow to yellow degradation product of realgar, as the initial arsenic sulfide material used for the synthesis of the amorphous pigment. To the best of our knowledge, this is the first time that combined pararealgar/amorphous arsenic sulfide Raman spectra are reported in historical samples. Therefore, this would be the first identification of pararealgar as the starting material to produce amorphous, arsenic sulfide pigments used in artworks.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000423246900033 Publication Date 2017-10-12  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0143-7208 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 3.473 Times cited (up) 7 Open Access  
  Notes ; This research is made possible with the support of the Belgian Science Policy Office (BELSPO, Brussels) through the research program Science for a Sustainable Development SDD: “Long-term role and fate of metal -sulfides in painted works of art S2ART” (SD/RI/04A). The authors would like to acknowledge the owner of the Abraham Mignon painting, Cecile Glaude for her help with SEM-EDX analyses as well as Livia Depuyt, Carlota Barbosa and Athanasia Fragkou for their assistance. The authors also acknowledge Dr. Karel Palka and Prof. Miroslav Week for their help with the synthesis of the amorphous arsenic sulfide references. ; Approved Most recent IF: 3.473  
  Call Number UA @ admin @ c:irua:149307 Serial 5648  
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Author Delaney, J.K.; Conover, D.M.; Dooley, K.A.; Glinsman, L.; Janssens, K.; Loew, M. url  doi
openurl 
  Title Integrated X-ray fluorescence and diffuse visible-to-near-infrared reflectance scanner for standoff elemental and molecular spectroscopic imaging of paints and works on paper Type A1 Journal article
  Year 2018 Publication Heritage science Abbreviated Journal  
  Volume 6 Issue 6 Pages 31  
  Keywords A1 Journal article; Art; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)  
  Abstract Prior studies have shown the improved ability to identify artists' pigments by combining results from X-ray fluorescence (XRF), which provides elemental information, with reflectance spectroscopy in the visible to near infrared (400-1000 nm) that provides information on electronic transitions. Extending the spectral range of reflectance spectroscopy into the UV, 350-400 nm, allows identification of several white pigments since their electronic transitions occur in this region (e.g., zinc white and rutile and anatase forms of titanium white). Extending the range further into the infrared, out to 2500 nm, provides information on vibrational transitions of various functional groups, such as hydroxyl, carbonate, and methyl groups. This allows better identification of mineral-based pigments and some paint binders. The combination of elemental information with electronic and vibrational transitions provides a more robust method to identify artists' materials in situ. The collection of both sets of spectral information across works of art, such as paintings and works on paper, allows generating a more complete map of artists' materials. Here, we describe a 2-D scanner that simultaneously collects XRF spectra and reflectance spectra from 350 to 2500 nm across the surfaces of works of art. The scanner consists of a stationary, single pixel XRF spectrometer and fiber optic reflectance spectrometer along with a 2-D position-controlled easel that moves the artwork in front of the two detection systems. The dual-mode scanner has been tested on a variety of works of art from illuminated manuscripts (0.1 x 0.1 m(2)) to paintings as large as 1.7 x 1.9 m(2). The scanner is described and two sets of results are presented. The first is the XRF scanning of a large warped panel painting by Andrea del Sarto titled Charity. The second is a combined XRF and reflectance scan of Georges Seurat's painting titled Haymakers at Montfermeil. The XRF was collected at 1 mm spatial sampling and the reflectance spectral data at 3 mm. Combining the results from the data sets was found to enhance the identification of pigments as well as yield distribution maps, in spite of the relatively low reflectance spatial sampling. The elemental and reflectance maps allowed the identification and mapping of lead white, cobalt blue, viridian, ochres, and likely chrome yellow. The maps also provide information on the mixing of pigments. While the reflectance image cube has 10-20x larger spatial samples than desired, the elimination of having to use two hyperspectral cameras to cover the range from 400 to 2500 nm makes for a low cost dual modality scanner.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000433601900001 Publication Date 2018-05-18  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 2050-7445 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor Times cited (up) 7 Open Access  
  Notes ; The authors acknowledge funding from the National Science Foundation (Award 1041827). J.K.D. and D.M.C. acknowledge funding from the Andrew W. Mellon and Samuel H. Kress Foundations. The authors are grateful to David Martin and Dennis Murphy of SmartDrive Ltd., Gary Fager of Malvern PANalytical, and Gao Ning of XOS for advice. KJ acknowledges support from EU-InterReg project SmartLight and from GOA Project SolarPaint (University of Antwerp Research Council). ; Approved Most recent IF: NA  
  Call Number UA @ admin @ c:irua:152039 Serial 5665  
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Author da Silva, A.T.; Legrand, S.; van der Snickt, G.; Featherstone, R.; Janssens, K.; Bottinelli, G. doi  openurl
  Title MA-XRF imaging on Rene Magritte's La condition humaine : insights into the artist's palette and technique and the discovery of a third quarter of La pose enchantee Type A1 Journal article
  Year 2017 Publication Heritage science Abbreviated Journal  
  Volume 5 Issue Pages 37  
  Keywords A1 Journal article; Art; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)  
  Abstract Magritte's composition La condition humaine, 1935 was found to conceal under its paint layers an entire quarter of a lost composition by the artist, until recently only known from a small black/white catalogue illustration-La pose enchantee, 1927. This study is the latest contribution to the discovery of the artist's missing painting, now known to have been cut into four parts and re-used by Magritte as the support for new compositions. Non-destructive analytical and examination methods and specifically macroscopic X-ray fluorescence (MAXRF) scanning and conventional X-ray radiography (XRR) were the two non-destructive analytical and examination methods used to study both compositions and add to the existing knowledge on the artist's palette during both periods. The first method is capable of identifying the presence and the distribution of key chemical elements present in artists' materials. In some instances elemental mapping provided useful information on the hidden painting, but conventional X-ray radiography (XRR) enabled a better visualisation of the form and paint application of the underlying composition. Furthermore, the turnover edges of the canvas reveal after over 80 years the artist's palette directly to the viewer. Additional XRF scanning of this exposed paint has confirmed and added to the existing research published to date of this lost painting, including a proposed colour reconstruction, but at the same time highlighting the need for further analytical research involving both non-destructive point analysis and the use of paint samples.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000410413500001 Publication Date 2017-08-04  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 2050-7445 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor Times cited (up) 7 Open Access  
  Notes ; ; Approved Most recent IF: NA  
  Call Number UA @ admin @ c:irua:145695 Serial 5696  
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Author Schalm, O.; de Raedt, I.; Caen, J.; Janssens, K. pdf  doi
openurl 
  Title A methodology for the identification of glass panes of different origin in a single stained glass window: application on two 13th century windows Type A1 Journal article
  Year 2010 Publication Journal of cultural heritage Abbreviated Journal J Cult Herit  
  Volume 11 Issue 4 Pages 487-492  
  Keywords A1 Journal article; Art; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)  
  Abstract The chemical composition of 11 glass panes originating from two 13th century non-figurative windows were analyzed by means of Scanning Electron MicroscopyEnergy Dispersive X-ray system (SEM-EDX). The windows were discovered in the back-wall of the triforium during the restoration of the choir of the cathedral St. Michael and St. Gudule in Brussels (Belgium). In order to determine if these windows were fabricated with glass of different origin or not, the compositional difference between the panes were compared with the variation in composition as a result of the following causes: (1) compositional fluctuation between panes cut from the same sheet of glass, (2) compositional fluctuation caused when panes are cut from different sheets that were made with the same batch, (3) compositional fluctuation caused when the glass is made from different batches at the same production center, and (4) compositional fluctuation as a result of glass produced at different fabrication centers.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000282680500016 Publication Date 2010-07-07  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1296-2074 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 1.838 Times cited (up) 7 Open Access  
  Notes ; ; Approved Most recent IF: 1.838; 2010 IF: 1.162  
  Call Number UA @ admin @ c:irua:84942 Serial 5707  
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Author Denecke, M.A.; de Nolf, W.; Janssens, K.; Brendebach, B.; Falkenberg, G.; Noseck, U.; Rothkirch, A. doi  openurl
  Title mu-X-ray fluorescence and mu-X-ray diffraction investigations of sediment from the Ruprechtov nuclear waste disposal natural analog site Type A1 Journal article
  Year 2008 Publication Spectrochimica acta: part B : atomic spectroscopy Abbreviated Journal Spectrochim Acta B  
  Volume 63 Issue 4 Pages 484-492  
  Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)  
  Abstract  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000255817200005 Publication Date 2008-01-15  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0584-8547; 0038-6987 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 3.241 Times cited (up) 7 Open Access  
  Notes Approved Most recent IF: 3.241; 2008 IF: 2.853  
  Call Number UA @ admin @ c:irua:69131 Serial 5739  
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Author de Nolf, W.; Jaroszewicz, J.; Terzano, R.; Lind, O.C.; Salbu, B.; Vekemans, B.; Janssens, K.; Falkenberg, G. doi  openurl
  Title Possibilities and limitations of synchrotron X-ray powder diffraction with double crystal and double multilayer monochromators for microscopic speciation studies Type A1 Journal article
  Year 2009 Publication Spectrochimica acta: part B : atomic spectroscopy Abbreviated Journal Spectrochim Acta B  
  Volume 64 Issue 8 Pages 775-781  
  Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)  
  Abstract The performance of a combined microbeam X-ray fluorescence/X-ray powder diffraction (XRF/XRPD) measurement station at Hamburger Synchrotronstrahlungslabor (HASYLAB) Beamline L is discussed in comparison to that at European Synchrotron Radiation Facility (ESRF) ID18F/ID22. The angular resolution in the X-ray diffractograms is documented when different combinations of X-ray source, optics and X-ray diffraction detectors are employed. Typical angular resolution values in the range 0.30.5° are obtained at the bending magnet source when a pink beam form of excitation is employed. A similar setup at European Synchrotron Radiation Facility beamlines ID18F and ID22 allows to reach angular resolution values of 0.10.15°. In order to document the possibilities and limitations for speciation of metals in environmental materials by means of Hamburger Synchrotronstrahlungslabor Beamline L X-ray fluorescence/X-ray powder diffraction setup, two case studies are discussed, one involved in the identification of the crystal phases in which heavy metals such as chromium, iron, barium and lead are present in polluted soils of an industrial site (Val Basento, Italy) and another involved in the speciation of uranium in depleted uranium particles (Ceja Mountains, Kosovo). In the former case, the angular resolution is sufficient to allow identification of most crystalline phases present while in the latter case, it is necessary to dispose of an angular resolution of ca. 0.2° to distinguish between different forms of oxidized uranium.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000269995300010 Publication Date 2009-06-12  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0584-8547; 0038-6987 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 3.241 Times cited (up) 7 Open Access  
  Notes Approved Most recent IF: 3.241; 2009 IF: 2.719  
  Call Number UA @ admin @ c:irua:79739 Serial 5778  
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Author Kukhlevsky, S.V.; Mechler, M.; Csapó, L.; Janssens, K.; Samek, O. doi  openurl
  Title Resonant backward scattering of light by a subwavelength metallic slit with two open sides Type A1 Journal article
  Year 2005 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B  
  Volume 72 Issue 16 Pages 165421,1-165421,7  
  Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)  
  Abstract The backward scattering of TM-polarized light by a two-side-open subwavelength slit in a metal film is analyzed. We show that the reflection coefficient versus wavelength possesses a Fabry-Perot-like dependence that is similar to the anomalous behavior of transmission reported in the study [Y. Takakura, Phys. Rev. Lett. 86, 5601 (2001)]. The open slit totally reflects the light at the near-to-resonance wavelengths. In addition, we show that the interference of incident and resonantly backward-scattered light produces in the near-field diffraction zone a spatially localized wave whose intensity is 10103 times greater than the incident wave, but one order of magnitude smaller than the intracavity intensity. The amplitude and phase of the resonant wave at the slit entrance and exit are different from that of a Fabry-Perot cavity.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000232934900123 Publication Date 2005-10-21  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1098-0121; 1550-235x ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 3.836 Times cited (up) 7 Open Access  
  Notes Approved Most recent IF: 3.836; 2005 IF: 3.185  
  Call Number UA @ admin @ c:irua:71385 Serial 5815  
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Author van der Snickt, G.; Schalm, O.; Caen, J.; Janssens, K.; Schreiner, M. pdf  doi
openurl 
  Title Blue enamel on sixteenth- and seventeenth-century window glass : deterioration, microstructure, composition and preparation Type A1 Journal article
  Year 2006 Publication Studies in conservation Abbreviated Journal Stud Conserv  
  Volume 51 Issue Pages 212-222  
  Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)  
  Abstract  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000241941100006 Publication Date 2014-01-09  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0039-3630; 2047-0584 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 0.578 Times cited (up) 8 Open Access  
  Notes Approved Most recent IF: 0.578; 2006 IF: 0.609  
  Call Number UA @ admin @ c:irua:60712 Serial 5492  
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Author van der Linden, V.; Schalm, O.; Houbraken, J.; Thomas, M.; Meesdom, E.; Devos, A.; van Dooren, R.; Nieuwdorp, H.; Janssen, E.; Janssens, K. doi  openurl
  Title Chemical analysis of 16th to 19th century Limoges School painted enamel objects in three museums of the Low Countries Type A1 Journal article
  Year 2010 Publication X-ray spectrometry Abbreviated Journal X-Ray Spectrom  
  Volume 39 Issue 2 Pages 112-121  
  Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)  
  Abstract In this study, the results of analysing of a series of 16th-19th century painted enamel objects of the Limoges School currently in collections in three Dutch and Flemish museums by means of portable and micro x-ray fluorescence analysis (PXRF and µ-XRF) and electron probe micro analysis (EPMA) are presented. The aim of the investigation was the authentication of specific pieces. Therefore, the glass compositions as well as the (glass) colouring agents used by the Limoges' artists were studied as a function of the age of the objects. Due to the evolution of these properties, it is possible to approximately date these objects based on their chemical composition. The complete émail peint collection of the Museum Boijmans-Van Beuningen (Rotterdam, The Netherlands), consisting of 20 émail peint plaques, was analysed with µ-XRF. Quantitative information was obtained by EPMA analysis of 15 enamel fragments of objects from museum and private collections in the Low Countries. PXRF analyses were performed on the painted enamel collection of the Antwerp Vleeshuis Museum (13 objects) and the Mayer van den Bergh Museum (4 objects) and on a set of 18 plaques that were donated to the Boijmans-Van Beuningen Museum by a private collector. The results obtained by means of EPMA, µ-XRF and PXRF proved to be useful in the discrimination of 16th century painted enamel objects from those of the19th century. From a total of 70 objects examined, 2 objects (OM964A and OM993) featured a chemical signature that deviated from the published literature composition and pigment use consistent with its presumed period of manufacture.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000275959400007 Publication Date 2009-08-11  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0049-8246 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 1.298 Times cited (up) 8 Open Access  
  Notes ; ; Approved Most recent IF: 1.298; 2010 IF: 1.661  
  Call Number UA @ admin @ c:irua:82325 Serial 5509  
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Author Nuyts, G.; Cagno, S.; Bugani, S.; Janssens, K. url  doi
openurl 
  Title Micro-XANES study on Mn browning: use of quantitative valence state maps Type A1 Journal article
  Year 2015 Publication Journal of analytical atomic spectrometry Abbreviated Journal J Anal Atom Spectrom  
  Volume 30 Issue 3 Pages 642-650  
  Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)  
  Abstract Historical glass, especially non-durable medieval glass, can undergo corrosion. This sometimes results in the formation of dark-coloured manganese-rich inclusions that reduce the transparency of the glass. While unaltered bulk glass contains manganese mainly present in the +II valence state, inside the inclusions Mn is present in higher valence states (+III to +IV). Two different strategies may be considered by conservators when aiming to improve the transparency. One is based on the reduction of highly oxidised black/brown compounds using mildly reducing solutions, while the other focuses more on the extraction of manganese from the inclusions by the application of chelating agents. In this paper, a method for quantitative mapping of the Mn speciation inside partially corroded historical windowpanes based on X-Ray Absorption Near-Edge Structure (XANES) spectroscopy is discussed. The calibration of such Mn valence state maps based on the combo method, a fairly reliable way to determine the oxidation state, is described in more detail. This method is used to evaluate the effect of reducing treatments on historical glass, dated to the 14th century and originating from Sidney Sussex College (Cambridge, UK), suffering from Mn browning. Glasses were examined by means of Synchrotron Radiation (SR) based microscopic X-Ray Absorption Near-Edge Structure (mXANES) spectroscopy and microscopic X-Ray Fluorescence (mXRF). X-Ray elemental distribution maps of glass cross-sections are recorded at different energies, while Mn K-edge spectra are used to convert these into Mn valence state (VS) maps. Such valence state maps will allow evaluation of a reducing treatment.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000350650800009 Publication Date 2015-02-23  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0267-9477 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 3.379 Times cited (up) 8 Open Access  
  Notes ; This research was supported by the Interuniversity Attraction Poles Programme Belgian Science Policy (IUAP VI/16) and partially by the Research Council of Norway through its Centres of Excellence funding scheme, project number 223268/ F50. The text also presents results of Center of Excellence AGRECHEM (Research Fund University of Antwerp, Belgium) and from the Fund for Scientific Research (FWO, Brussels, Belgium) projects no. G.0C12.13 and G.01769.09. We gratefully acknowledge ESRF for granting beamtime (experiment EC768) and the beamline scientists of ID21 for their support. The authors also want to thank Leonie Seliger of Canterbury Cathedral, UK, the Sidney Sussex College Council and Bursar Charles Larkum for providing the archaeological samples of the Franciscan Friary which are kept in store for Sidney Sussex College in Cambridge (UK). ; Approved Most recent IF: 3.379; 2015 IF: 3.466  
  Call Number UA @ admin @ c:irua:125476 Serial 5719  
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Author Rindby, A.; Janssens, K.; Osán, J. doi  openurl
  Title Reconstruction of the three-dimensional distribution of elements in fly-ash particles by micro-XRF spectroscopy Type A1 Journal article
  Year 2003 Publication X-ray spectrometry Abbreviated Journal X-Ray Spectrom  
  Volume 32 Issue 3 Pages 248-257  
  Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)  
  Abstract  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000183630400011 Publication Date 2003-06-12  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0049-8246 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 1.298 Times cited (up) 8 Open Access  
  Notes Approved Most recent IF: 1.298; 2003 IF: 1.227  
  Call Number UA @ admin @ c:irua:41805 Serial 5807  
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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. pdf  doi
openurl 
  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
  Year 2017 Publication Microchemical journal Abbreviated Journal Microchem J  
  Volume 132 Issue Pages 179-184  
  Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)  
  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.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000399845700026 Publication Date 2017-02-04  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0026-265x; 0026-265x ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 3.034 Times cited (up) 8 Open Access  
  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  
  Call Number UA @ admin @ c:irua:152647 Serial 5830  
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Author Alfeld, M.; Janssens, K.; Sasov, A.; Liu, X.; Kostenko, A.; Rickers-Appel, K.; Falkenberg, G. doi  openurl
  Title The use of full-field XRF for simultaneous elemental mapping Type P1 Proceeding
  Year 2010 Publication Abbreviated Journal  
  Volume Issue Pages 111-118  
  Keywords P1 Proceeding; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)  
  Abstract The characteristics of a Full-Field X-ray Fluorescence (FF-XRF) set-up for element-specific imaging, installed at the HASYLAB synchrotron radiation source, were determined. A lateral resolution of 10 μm and limits of detection in the percentage range were found. Further potential developments in CCDs available for FF-XRF are discussed and the use of polycapillary lenses as image transfer optics is illustrated in some explorative experiments.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000278534600020 Publication Date 2010-04-16  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 978-0-7354-0764-0 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor Times cited (up) 8 Open Access  
  Notes ; This research was supported by the Interuniversity Attraction Poles Programme – Belgian Science Policy (IUAP VI/16) and by GOA XANES meets EELS (Research Fund University of Antwerp, Belgium). M. Alfeld is supported by the Research Foundation – Flanders (FWO). The research leading to these results has received funding from the European Community's Seventh Framework Programme (FP7/ 2007-2013) under grant agreement no 226716. ; Approved Most recent IF: NA  
  Call Number UA @ admin @ c:irua:82179 Serial 5891  
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Author Singh, B.R.; Timsina, Y.N.; Lind, O.C.; Cagno, S.; Janssens, K. url  doi
openurl 
  Title Zinc and iron concentration as affected by nitrogen fertilization and their localization in wheat grain Type A1 Journal article
  Year 2018 Publication Frontiers in plant science Abbreviated Journal Front Plant Sci  
  Volume 9 Issue 9 Pages  
  Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)  
  Abstract Nearly half of the world cereal production comes from soils low or marginal in plant available zinc, leading to unsustainable and poor quality grain production. Therefore, the effects of nitrogen (N) rate and application time on zinc (Zn) and iron (Fe) concentration in wheat grain were investigated. Wheat (Triticum aestivum var. Krabat) was grown in a growth chamber with 8 and 16 h of day and night periods, respectively. The N rates were 29, 43, and 57 mg N kg(-1) soil, equivalent to 80, 120, and 160 kg N ha(-1). Zinc and Fe were applied at 10 mg kg(-1) growth media. In one of the N treatments, additional Zn and Fe through foliar spray (6 mg of Zn or Fe in 10 ml water / pot) was applied. Micro-analytical localization of Zn and Fe within grain was performed using scanning macro-X-ray fluorescence (MA-XRF) and laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS). The following data were obtained: grain and straw yield pot 1, 1000 grains weight, number of grains pot 1, whole grain protein content, concentration of Zn and Fe in the grains. Grain yield increased from 80 to 120 kg N ha(-1) rates only and decreased at 160 kg N ha(-1) g. Relatively higher protein content and Zn and Fe concentration in the grain were recorded with the split N application of 160 kg N ha(-1). Soil and foliar supply of Zn and Fe (Zn + Fes+f), with a single application of 120 kg N ha(-1) N at sowing, increased the concentration of Zn by 46% and of Fe by 35%, as compared to their growth media application only. Line scans of freshly cut areas of sliced grains showed co-localization of Zn and Fe within germ, crease and aleurone. We thus conclude that split application of N at 160 kg ha(-1) at sowing and stem elongation, in combination with soil and foliar application of Zn and Fe, can be a good agricultural practice to enhance protein content and the Zn and Fe concentration in grain.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000427034400002 Publication Date 2018-03-09  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1664-462x ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 4.298 Times cited (up) 8 Open Access  
  Notes ; The research part of this master study was financed by the project “Mineral Improved Food and Feed Crops for Human and Animal Health” (Project No. 332160UA) and by a grant from the Norwegian Ministry of Foreign Affairs under the Program for Higher Education, Research and Development (HERD) in Western Balkan. The financial assistance for conducting this study is gratefully acknowledged. We also acknowledge the assistance by CERAD: this study has been funded by the Norwegian Research Council through its Centre of Excellence (CoE) funding scheme (Project No. 223268/F50). This research was supported by the Hercules Foundation (Brussels, Belgium) under grant AUHA09004 and FWO (Brussels, Belgium) Project Nos. G.0C12.13 and G.01769.09. ; Approved Most recent IF: 4.298  
  Call Number UA @ admin @ c:irua:149859 Serial 5924  
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Author Marchetti, A.; Saniz, R.; Krishnan, D.; Rabbachin, L.; Nuyts, G.; De Meyer, S.; Verbeeck, J.; Janssens, K.; Pelosi, C.; Lamoen, D.; Partoens, B.; De Wael, K. pdf  url
doi  openurl
  Title Unraveling the Role of Lattice Substitutions on the Stabilization of the Intrinsically Unstable Pb2Sb2O7Pyrochlore: Explaining the Lightfastness of Lead Pyroantimonate Artists’ Pigments Type A1 Journal article
  Year 2020 Publication Chemistry Of Materials Abbreviated Journal Chem Mater  
  Volume 32 Issue 7 Pages 2863-2873  
  Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation); Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT)  
  Abstract The pyroantimonate pigments Naples yellow and lead tin antimonate yellow are recognized as some of the most stable synthetic yellow pigments in the history of art. However, this exceptional lightfastness is in contrast with experimental evidence suggesting that this class of mixed oxides is of semiconducting nature. In this study the electronic structure and light-induced behavior of the lead pyroantimonate pigments were determined by means of a combined multifaceted analytical and computational approach (photoelectrochemical measurements, UV-vis diffuse reflectance spectroscopy, STEM-EDS, STEM-HAADF, and density functional theory calculations). The results demonstrate both the semiconducting nature and the lightfastness of these pigments. Poor optical absorption and minority carrier mobility are the main properties responsible for the observed stability. In addition, novel fundamental insights into the role played by Na atoms in the stabilization of the otherwise intrinsically unstable Pb2Sb2O7 pyrochlore were obtained.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000526394000016 Publication Date 2020-04-14  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0897-4756 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 8.6 Times cited (up) 8 Open Access OpenAccess  
  Notes Universiteit Antwerpen; Belgian Federal Science Policy Office; Approved Most recent IF: 8.6; 2020 IF: 9.466  
  Call Number EMAT @ emat @c:irua:168819 Serial 6363  
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Author Janssens, K.L.; Partoens, B.; Peeters, F.M. url  doi
openurl 
  Title Magnetoexciton in vertically coupled InP/GaInP quantum disks: effect of strain on the exciton ground state Type A1 Journal article
  Year 2004 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B  
  Volume 69 Issue Pages 235320,1-7  
  Keywords A1 Journal article; Condensed Matter Theory (CMT)  
  Abstract  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Lancaster, Pa Editor  
  Language Wos 000222531400073 Publication Date 2004-06-25  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1098-0121;1550-235X; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 3.836 Times cited (up) 9 Open Access  
  Notes Approved Most recent IF: 3.836; 2004 IF: 3.075  
  Call Number UA @ lucian @ c:irua:62434 Serial 1917  
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Author van der Linden, V.; Meesdom, E.; Devos, A.; van Dooren, R.; Nieuwdorp, H.; Janssen, E.; Balace, S.; Vekemans, B.; Vincze, L.; Janssens, K. doi  openurl
  Title PXRF, \mu-XRF, vacuum \mu-XRF, and EPMA analysis of Email Champlevé objects present in Belgian museums Type A1 Journal article
  Year 2011 Publication Microscopy and microanalysis Abbreviated Journal Microsc Microanal  
  Volume 17 Issue 5 Pages 674-685  
  Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)  
  Abstract The enamel of 20 Email Champlevé objects dating between the 12th and 19th centuries was investigated by means of microscopic and portable X-ray fluorescence analysis (μ-XRF and PXRF). Seven of these objects were microsampled and the fragments were analyzed with electron probe microanalysis (EPMA) and vacuum μ-XRF to obtain quantitative data about the composition of the glass used to produce these enameled objects. As a result of the evolution of the raw materials employed to produce the base glass, three different compositional groups could be discriminated. The first group consisted of soda-lime-silica glass with a sodium source of mineral origin (with low K content) that was opacified by addition of calcium antimonate crystals. This type of glass was only used in objects made in the 12th century. Email Champlevé objects from the beginning of the 13th century onward were enameled with soda-lime-silica glass with a sodium source of vegetal origin. This type of glass, which has a higher potassium content, was opacified with SnO2 crystals. The glass used for 19th century Email Champlevé artifacts was produced with synthetic and purified components resulting in a different chemical composition compared to the other groups. Although the four analytical techniques employed in this study have their own specific characteristics, they were all found to be suitable for classifying the objects into the different chronological categories.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000295609100005 Publication Date 2011-09-23  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1431-9276 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 1.891 Times cited (up) 9 Open Access  
  Notes ; ; Approved Most recent IF: 1.891; 2011 IF: 3.007  
  Call Number UA @ admin @ c:irua:92827 Serial 5791  
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Author Eliaerts, J.; Dardenne, P.; Meert, N.; Van Durme, F.; Samyn, N.; Janssens, K.; De Wael, K. url  doi
openurl 
  Title Rapid classification and quantification of cocaine in seized powders with ATR-FTIR and chemometrics Type A1 Journal article
  Year 2017 Publication Drug testing and analysis Abbreviated Journal Drug Test Anal  
  Volume 9 Issue 10 Pages 1480-1489  
  Keywords A1 Journal article; Pharmacology. Therapy; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)  
  Abstract Traditionally, fast screening for the presence of cocaine in unknown powders is performed by means of colour tests. The major drawbacks of these tests are subjective colour evaluation depending on the operator (50 shades of blue) and a lack of selectivity. An alternative fast screening technique is Fourier Transform InfraRed (FTIR) spectrometry. This technique provides spectra that are difficult to interpret without specialized expertise and showing a lack of sensitivity for the detection of cocaine in mixtures. To overcome these limitations, a portable FTIR spectrometer using Attenuated Total Reflectance (ATR) sampling was combined with a multivariate technique, called Support Vector Machines (SVM). Representative street drug powders (n = 482), seized during the period January 2013 to July 2015, and reference powders (n = 33) were used to build and validate a classification model (n = 515) and a quantification model (n = 378). Both models were compared with the conventional chromatographic techniques. The SVM classification model showed a high sensitivity, specificity and efficiency (99%). The SVM quantification model determined cocaine content with a root mean squared error of prediction (RMSEP) of 6% calculated over a wide working range from 4 to 99 w%. In conclusion, the developed models resulted in a clear output (cocaine detected or cocaine not detected) and a reliable estimation of the cocaine content in a wide variety of mixtures. The ATR-FTIR technique combined with SVM is a straightforward, user-friendly and fast approach for routine classification and quantification of cocaine in seized powders.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000413685200001 Publication Date 2016-12-17  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1942-7603; 1942-7611 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 3.469 Times cited (up) 9 Open Access  
  Notes ; ; Approved Most recent IF: 3.469  
  Call Number UA @ admin @ c:irua:139483 Serial 5799  
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Author Ayalew, E.; Janssens, K.; De Wael, K. url  doi
openurl 
  Title Unraveling the reactivity of minium towards bicarbonate and the role of lead oxides therein Type A1 Journal article
  Year 2016 Publication Analytical chemistry Abbreviated Journal Anal Chem  
  Volume 88 Issue 3 Pages 1564-1569  
  Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)  
  Abstract Understanding the reactivity of (semiconductor) pigments provides vital information on how to improve conservation strategies for works of art in order to avoid rapid degradation of the pigments. This study focuses on the photoactivity of minium (Pb3O4), a semiconductor pigment, that gives rise to strong discoloration phenomena upon exposure to various environmental conditions. To demonstrate its photoactivity, an electrochemical setup with minium-modified graphite electrode (C|Pb3O4) was used. It is confirmed that minium is a p-type semiconductor which is photoactive during illumination and becomes inactive in the dark. Raman measurements confirm the formation of the degradation products. The photoactivity of a semiconductor pigment is partly defined by the presence of lead oxide (PbO) impurities; these introduce new states in the original band gap. It will be experi-mentally evidenced that the presence of PbO particles in minium leads to an upward shift of the valence band that reduces the band gap. Thus, upon photoexcitation, the electron/hole separation is more easily initialized. The PbO/Pb3O4 composite electrodes demonstrate a higher reductive photocurrent compared to the photocurrent registered at pure PbO or Pb3O4 modified electrodes. Upon exposure to light with energy close to and above the band gap, electrons are excited from the valence band to the conduction band to initialize the reduction of Pb(IV) to Pb(II), resulting in the initial formation of PbO. However in the presence of bicarbonate ions, a significantly higher photoreduction current is recorded since the PbO reacts further to form hydrocerussite. Therefore the presence of bicarbonates in the environment stimulates the photodecomposition process of minium and plays an important role in the degradation process.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000369471100014 Publication Date 2015-12-31  
  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 (up) 9 Open Access  
  Notes ; The authors acknowledge Sanne Aerts from the Laboratory of Adsorption and Catalysis (LADCA) of the University of Antwerp for her help with the UV-vis-DR. Financial support from the SOLARPAINT BOF-GOA project (University of Antwerp Research Council) is acknowledged. The authors are also indebted to F. Vanmeert for performing the XRD measurements. ; Approved Most recent IF: 6.32  
  Call Number UA @ admin @ c:irua:129963 Serial 5888  
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Author Vanmeert, F.; Hendriks, E.; van der Snickt, G.; Monico, L.; Dik, J.; Janssens, K. doi  openurl
  Title Chemical Mapping by Macroscopic X-ray Powder Diffraction (MA-XRPD) of Van Gogh's Sunflowers : identification of areas with higher degradation risk Type A1 Journal article
  Year 2018 Publication Angewandte Chemie: international edition in English Abbreviated Journal Angew Chem Int Edit  
  Volume 57 Issue 25 Pages 7418-7422  
  Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)  
  Abstract The discoloration rate of chrome yellow (CY), a class of synthetic inorganic pigments (PbCr1-xSxO4) frequently used by Van Gogh and his contemporaries, strongly depends on its sulfate content and on its crystalline structure (either monoclinic or orthorhombic). Macroscopic X-Ray powder diffraction imaging of selected areas on Van Gogh's Sunflowers (Van Gogh Museum, Amsterdam) revealed the presence of two subtypes of CY: the light-fast monoclinic PbCrO4 (LF-CY) and the light-sensitive monoclinic PbCr1-xSxO4 (x approximate to 0.5; LS-CY). The latter was encountered in large parts of the painting (e.g., in the pale-yellow background and the bright-yellow petals, but also in the green stems and flower hearts), thus indicating their higher risk for past or future darkening. Overall, it is present in more than 50% of the CY regions. Preferred orientation of LS-CY allows observation of a significant ordering of the elongated crystallites along the direction of Van Gogh's brush strokes.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000434949200023 Publication Date 2018-03-02  
  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 11.994 Times cited (up) 10 Open Access  
  Notes ; The authors acknowledge financial support from BELSPO (Brussels) S2-ART, the NWO (The Hague) Science4Arts “ReVisRembrandt” project, the GOA Project Solarpaint (University of Antwerp Research Council), and the Interreg Smart*Light project. Raman analyses were performed using the European MOLAB platform, which is financially supported by the Horizon 2020 Programme (IPERION CH Grant 654028). The authors thank the staff of the Van Gogh Museum for their collaboration. ; Approved Most recent IF: 11.994  
  Call Number UA @ admin @ c:irua:153185 Serial 5517  
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Author Rouchon, V.; Pellizzi, E.; Duranton, M.; Vanmeert, F.; Janssens, K. doi  openurl
  Title Combining XANES, ICP-AES, and SEM/EDS for the study of phytate chelating treatments used on iron gall ink damaged manuscripts Type A1 Journal article
  Year 2011 Publication Journal of analytical atomic spectrometry Abbreviated Journal J Anal Atom Spectrom  
  Volume 26 Issue 12 Pages 2434-2441  
  Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)  
  Abstract Many historical documents written with iron gall inks are endangered by the corrosive effects of these inks. In this work, a combination of complementary analytical methods was used for the first time in order to study the phytate process which is used in conservation studios to stabilize damaged manuscripts. This process consists of an antioxidant treatment performed by means of a calcium phytate (CP) solution, followed by a deacidification treatment performed with a calcium carbonate (CC) solution. The antioxidant treatment capitalizes on the properties of myo-inositol hexaphosphoric acid (phytic acid) that inhibits iron through chelation. In order to use relatively low acidic solutions, the pH of the CP solution is increased up to values between 5 and 6, which is in the range of the CP precipitation threshold. This study was performed on laboratory samples made of paper impregnated with iron gall ink and artificially aged in climatic chambers. It aims to investigate how the CP precipitate impacts the efficiency of the treatment. Side effects, such as elemental losses and deposits, were measured by means of several analytical techniques (FeK Edge XANES, SEM/EDS, and ICP-AES). These measurements were crosschecked with a ready to use colour spot test made of bathophenanthroline impregnated paper. It appeared that the CP treatment should necessarily be followed by the deacidification treatment in order to achieve long term stability. The precipitation of CP in the treating solution does finally not impact the efficiency of the treatment despite the fact that it should theoretically lower the availability of phytate to chelate iron. A scenario is proposed to explain this point.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000297030400008 Publication Date 2011-10-06  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0267-9477 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 3.379 Times cited (up) 10 Open Access  
  Notes ; This research was funded by SOLEIL (proposals 20060396 and 20080761) and was supported by the Interuniversity Attraction Poles Programme-Belgian Science Policy (IUAP VI/16). The text also presents results of GOA “XANES meets ELNES” (Research Fund University of Antwerp, Belgium) and from FWO (Brussels, Belgium) projects no. G.0704.08 and G.01769.09. We are thankful to the paper conservator students of the Institut National du Patrimoine who were involved in some of the sample preparations, and to Dr Dominique Thiaudiere and Dr Solenn Reguer for their assistance and help during the experiments performed at SOLEIL beamline “DIFFABS”. ; Approved Most recent IF: 3.379; 2011 IF: 3.220  
  Call Number UA @ admin @ c:irua:93845 Serial 5527  
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Author Vermeulen, M.; Sanyova, J.; Janssens, K.; Nuyts, G.; De Meyer, S.; De Wael, K. url  doi
openurl 
  Title The darkening of copper- or lead-based pigments explained by a structural modification of natural orpiment : a spectroscopic and electrochemical study Type A1 Journal article
  Year 2017 Publication Journal of analytical atomic spectrometry Abbreviated Journal J Anal Atom Spectrom  
  Volume 32 Issue 7 Pages 1331-1341  
  Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)  
  Abstract A combined Raman and electrochemical study of natural orpiment (As2S3), an arsenic sulfide pigment, was used to assess the quick formation of oxidized species such as arsenic oxide (As2O3) upon exposing the pigment to 405 nm or 532 nm monochromatic light while simultaneously recording the Raman spectra of the exposed sample. During this process, a distortion of the main band at 355 cm−1, associated with the stretching of the AsS3/2 pyramids of natural orpiment, was observed as well as an increased intensity of the 359 cm−1 band, corresponding to covalent AsAs bonds in natural orpiment. The distortion was accompanied by an overall decrease of the global Raman signal for natural orpiment, which could be explained by a loss in the crystal structure. The same phenomena were recorded in reference natural orpiment model paint samples stored for a long time together with verdigris (Cu(OH)2·(CH3COO)2·5H2O) and minium (Pb3O4) paints, the latter two appearing darkened on their sides closest to the orpiment sample as well as in several historical samples containing natural orpiment mixed with various blue pigments. By SEM-EDX and XRPD analysis, respectively on loose material and cast thin-sections of model paint samples, the darkening was identified as dark sulfide species such as chalcocite (Cu2S) and galena (PbS), suggesting the release of volatile sulfide or related species by the natural orpiment paint. XANES analyses of paint samples presenting AsAs bond increase indicated the presence of sulfur species most likely identified as organosulfur compounds formed upon the AsAs bond formation and explained the darkening of the Cu- and Pb-based pigments. To the best of our knowledge, this article reports for the first time the light-induced formation of AsAs bonds in natural orpiment used as an artists' pigment and objectively demonstrates the incompatibility between orpiment and (arsenic) sulfide-sensitive pigments.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000404998500007 Publication Date 2017-05-31  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0267-9477 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 3.379 Times cited (up) 10 Open Access  
  Notes ; This research is made possible with the support of the Belgian Science Policy Office (BELSPO, Brussels) through the research program Science for a Sustainable Development – SDD, “Long-term role and fate of metal-sulfides in painted works of art – S2ART” (SD/RI/04A). We gratefully acknowledge Julie Arslanoglu (Conservation and Scientific Research Department at the Metropolitan Museum of Art, New York, USA) for providing us the orpiment, verdigris and minium mock-up samples. We gratefully acknowledge the Paul Scherrer Institut, Villigen, Switzerland and the German Electron Synchrotron (DESY) for provision of synchrotron radiation beamtimes at respectively beamlines of the SLS and Petra III. ; Approved Most recent IF: 3.379  
  Call Number UA @ admin @ c:irua:144384 Serial 5564  
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Author Meulebroeck, W.; Baert, K.; Wouters, H.; Cosyns, P.; Ceglia, A.; Cagno, S.; Janssens, K.; Nys, K.; Terryn, H.; Thienpont, H. doi  openurl
  Title The identification of chromophores in ancient glass by the use of UV-VIS-NIR spectroscopy Type A1 Journal article
  Year 2010 Publication Proceedings of the Society of Photo-optical Instrumentation Engineers Abbreviated Journal  
  Volume 7726 Issue Pages 77260d-12  
  Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)  
  Abstract In this publication optical spectroscopy is considered to be a supplementary technique to study ancient colored glass. It results from a systematic study of the UV-VIS-NIR transmission spectra of intentionally colored glass fragments from various archaeological and historical sites and dated from the Roman period to the 21th century AD. The main goal consists of defining optical sensing parameters for this type of material. The considered colorants are iron, cobalt, manganese, copper and chromium. It is proved that many cases exist where optical spectroscopy can be seen as a straightforward, non-destructive, low-cost and in-situ applicable technique in identifying authentic material or to obtain information about the origin of the material. Possible sensing parameters are defined as the absence/presence of absorption bands characteristic for a specific coloring metal oxide and the spectral position of these bands. These parameters could reveal information about the applied furnace conditions and/or to the composition of the glass matrix. It is shown that the cobalt absorption band situated around 535 nm for soda rich glasses (Roman and industrial times) is shifted towards 526 nm for potash rich glasses (medieval and post-medieval times).  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000285287900011 Publication Date 2010-04-29  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0277-786x ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor Times cited (up) 10 Open Access  
  Notes ; ; Approved Most recent IF: NA  
  Call Number UA @ admin @ c:irua:111316 Serial 5650  
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Author Cagno, S.; Hellemans, K.; Lind, O.C.; Skipperud, L.; Janssens, K.; Salbu, B. doi  openurl
  Title LA-ICP-MS for Pu source identification at Mayak PA, the Urals, Russia Type A1 Journal article
  Year 2014 Publication Environmental science : processes & impacts Abbreviated Journal Environ Sci-Proc Imp  
  Volume 16 Issue 2 Pages 306-312  
  Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)  
  Abstract Information on Pu in environmental samples is traditionally based on the determination of the 240+239PU activity via Alpha Spectrometry (AS). A large number of alpha spectrometry sources (planchettes) containing radiochemically separated Pu are therefore stored worldwide and are available for further analyses. These archive samples represent a resource from which valuable information on isotopic composition of alpha emitters including Pu can be obtained. The relative abundances of Pu isotopes can be used to trace specific Pu sources and characterize the relative contributions of different Pu sources in a sample. Thus, in addition to the total 239+240PU activity, determination of the Pu-240/Pu-239 ratio can provide valuable information on the nature of the Pu emitting sources. The Pu isotopic ratios can be determined by mass spectrometry techniques such as Sector Field Inductively Coupled Plasma Mass Spectrometry (SF-ICPMS) or Accelerator Mass Spectrometry (AMS) that require dissolution and complete destruction of the material deposited on the planchettes. In this study Laser Ablation (LA)-quadrupole-ICP-MS has been employed for the analysis of Pu-239/Pu-240 ratios from alpha-planchettes prepared from samples originating from the Mayak PA nuclear facility, Russia. The results are compared with data from AMS and show that the Pu-240/Pu-239 ratios obtained by LA-ICP-MS can be utilized to distinguish weapons-grade Pu from civil reprocessing sources. Moreover, isotope ratio mapping can also be performed across the planchettes, allowing e.g. the visualization of possible inhomogeneities in the Pu-isotope distribution on their surface. Thus, this solid sample technique can be applied to extract additional information from existing archives of samples.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000331504100015 Publication Date 2013-12-09  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 2050-7887; 2050-7895 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 2.592 Times cited (up) 10 Open Access  
  Notes ; This work was supported by the Research Council of Norway through its Centres of Excellence funding scheme, project number 223268/F50, and the Hercules fund, Brussels (grant A11/0387). ; Approved Most recent IF: 2.592; 2014 IF: 2.171  
  Call Number UA @ admin @ c:irua:115791 Serial 5684  
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Author Kukhlevsky, S.V.; Mechler, M.; Csapo, L.; Janssens, K. doi  openurl
  Title Near-field diffraction of fs and sub-fs pulses: super resolution of NSOM in space and time Type A1 Journal article
  Year 2003 Publication Physics letters : A Abbreviated Journal Phys Lett A  
  Volume 319 Issue Pages 439-447  
  Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)  
  Abstract  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000187351800003 Publication Date 2003-11-07  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0375-9601 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 1.772 Times cited (up) 10 Open Access  
  Notes Approved Most recent IF: 1.772; 2003 IF: 1.324  
  Call Number UA @ admin @ c:irua:42959 Serial 5744  
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