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“Simulation of poly-capillary lenses for coherent and partially coherent x-rays”. Vincze L, Kukhlevsky SV, Janssens K, 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 , 81 (2004). http://doi.org/10.1117/12.560740
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.
Keywords: P1 Proceeding; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Times cited: 6
DOI: 10.1117/12.560740
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“Special issue on Microscopic and ultratrace x-ray fluorescence analysis: 2”. Janssens K, Journal of trace and microprobe techniques 14, 461 (1996)
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
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“Special issue: Proceedings of the 15th International Congress on X-ray Optics and Microanalysis”. Janssens K, Journal of analytical atomic spectroscopy 14, 357 (1999)
Keywords: A3 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
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“Spectrum evaluation”. van Espen P, Janssens K (1992).
Keywords: H3 Book chapter; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation); Chemometrics (Mitac 3)
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“Spread of façon-de-Venise glassmaking through central and western Europe”. Åmit Å, Janssens K, Schalm O, Kos M, Nuclear instruments and methods in physics research B 213, 717 (2004). http://doi.org/10.1016/S0168-583X903)01691-4
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1016/S0168-583X903)01691-4
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“SR-based X-ray microbeam techniques utilised for solid-state speciation of U in fuel particles”. Salbu B, Janssens K, Lind OC, Simionovici AS, Trekling T, Drakopoulos M, Snigireva I, Snigirev A, (2002)
Keywords: P3 Proceeding; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
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“Study of the degradation on historical documents induced by iron gall ink by means of scanning μ-XRF/μ-XRD”. de Nolf W, Janssens K, Rouchon V, Falkenberg G (2007).
Keywords: H3 Book chapter; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
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“Study of the early stages of Mn intrusion in corroded glass by means of combined SR FTIR/\muXRF imaging and XANES spectroscopy”. Nuyts G, Cagno S, Hellemans K, Veronesi G, Cotte M, Janssens K, Procedia Chemistry
T2 –, Youth in Conservation of Cultural Heritage Conference (YOCOCU), June 18-20, 2012, University of Antwerp, Antwerp, Belgium , 239 (2013). http://doi.org/10.1016/J.PROCHE.2013.03.030
Abstract: Historical glass, especially medieval glass, can undergo weathering under the influence of time and environmental conditions. The aim of this investigation was to better understand the processes involved in this natural degradation process by studying artificially altered glass samples prepared for the use of evaluation of conservation methods. Non-durable glass sensors produced by the Fraunhofer Institute (type M1.0) were used as a starting material for artificial alteration. These were immersed in acidic (pH = 0, 2, 4) and neutral solutions (1 h – 8 h). In a second stage the glass samples were immersed in a 0.5 M MnCl2 solution (24 h, 48 h and 72 h), allowing intrusion of Mn from the solution into the gel layer. The samples were characterized at different stages with reflectance FTIR spectroscopy, mu XRF mapping and mu XANES. All measurements were carried out at ESRF, beamline ID21. Reflectance FTIR spectroscopy measurements were performed in the 800 4000 cm(-1) range. Cluster analysis of the resulting maps evidenced the rapid growth of the gel layer in strong acidic conditions. The average spectra for each cluster feature show for the original glass a strong Si-O- stretching band between 900 and 1000 cm(-1), whereas the gel layer could be identified by the increasing Si-O-Si bands around 1100 and 1250 cm(-1). mu XRF maps were recorded at different stages of the experiment at energies around the Mn-K edge (6.539 keV) and with a step size of 2 by 2 m. These confirm the leaching of K+ and Ca+2 from the glass and the intrusion of Mn from the solution. Mn was found throughout the entire gel layer, but with a concentration gradient peaking at the surface. XANES point measurements were recorded at various points where Mn was present. No spatial variation was found, but linear combination fitting of the spectra with various Mn reference compounds indicated that Mn2+Mn23+O4 is the main Mn compound in the gel layer, as was hypothesised by Watkinson et al. The standard corroded glass samples studied here can be used for the evaluation of conservation treatments in follow-up experiments. (C) 2013 The Authors. Published by Elsevier B.V. Selection and peer-review under responsibility of the IA-CS (Italian Association of Conservation Scientists) and University of Antwerp
Keywords: P1 Proceeding; Engineering sciences. Technology; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Times cited: 4
DOI: 10.1016/J.PROCHE.2013.03.030
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“Sublayer composition evaluation of Artwork using active thermography”. Steenackers G, Peeters J, Janssens K, Quantitative infrared thermography
T2 –, QIRT 2018 : 14th Quantitative InfraRed Thermography Conference , 503 (2018)
Abstract: Infrared artwork inspection is typically performed through active thermography and infrared reflectography (IRR) with different setups and cameras. While IRR is an established technique in the museum field, exploiting mainly the IR-A (0.7 – 1.4 mu m) band to probe for hidden layers and modifications within the paint stratigraphy system, active thermography operating in the IR-C range (3 -5 mu m) is less frequently employed with the aim to visualize structural defects and features deeper inside the build-up. In this work, we investigate the usability of an IR-B+C system to identify overpainted works of art below a relatively thick absorbing layer of lead white paint.
Keywords: P1 Proceeding; Engineering sciences. Technology; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
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“Surface microanalysis”. Adams F, Adriaens A, Berghmans P, Janssens K, Analytica chimica acta 283, 19 (1993). http://doi.org/10.1016/0003-2670(93)85207-Z
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1016/0003-2670(93)85207-Z
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“A survey of the recent use of x-ray beam methods for non-destructive investigations in the cultural heritage sector”. Janssens K page 265 (2005).
Keywords: H3 Book chapter; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
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“Synchroton X-ray powder diffraction study of lead white oxidation by sodium hypochloride”. Clerici EA, De Meyer S, van der Snickt G, Janssens K, , 13 (2017)
Keywords: P1 Proceeding; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
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“Synchrotron light through ancient glass”. de Raedt I, Vekemans B, Janssens K, Adams F, Europhysics news 31, 15 (2000)
Keywords: A3 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
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“Synchrotron radiation-induced X-ray microanalysis”. Janssens K, Vincze L, Adams F, Jones KW, Analytica chimica acta 283, 98 (1993). http://doi.org/10.1016/0003-2670(93)85213-4
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1016/0003-2670(93)85213-4
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“Synchrotron radiation induced X-ray microfluorescence analysis”. Janssens K, Vincze L, Vekemans B, Aerts A, Adams F, Jones KW, Knöchel A, Microchimica acta
T2 –, 4th Workshop of the European-Microanalysis-Society on Modern, Developments and Applications in Microbeam Analysis, MAY, 1995, ST MALO, FRANCE , 87 (1996)
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.
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
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“The development process of an expert system for the automated interpretation of large epma data sets”. Janssens K, Dorrine W, van Espen P, Chemometrics and intelligent laboratory systems 4, 147 (1988). http://doi.org/10.1016/0169-7439(88)80086-8
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation); Chemometrics (Mitac 3)
DOI: 10.1016/0169-7439(88)80086-8
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“The hidden youth of Dirck Jacobsz leeuw : a portrait by Govert Flinck revealed”. Van Hommes ME, Lambour R, Du Mortier BM, De Winkel M, Tauber G, Alfeld M, Janssens K, Dik J, The Rijksmuseum bulletin 64, 4 (2016)
Keywords: A1 Journal article; Art; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
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“The rediscovered portrait of Prospero Farinacci by Caravaggio”. Cardinali M, De Ruggieri MB, Leone G, Prohaska W, Alfeld M, Janssens K, Artibus et historiae : an art anthology , 249 (2016)
Abstract: Caravaggio's early production as a portrait painter is still the subject of research and a fount of enigmas. Despite the numerous citations in documents, only rarely have these been linked unequivocally to paintings known to date. This is also the case with the `portrait of Farinaccio criminalist painted on a head-size canvas believed to be by Michelangelo from Caravaggio', that was listed in the 1638 inventory of the Marquis Giustiniani and with `the speaker wearing a robe, painted by Caravaggio' on a head-size canvas, owned in 1652 by Caterina Campani, Onorio Longhi's wife. The present multidisciplinary research examines the rediscovery of the portrait of Prospero Farinacci by Caravaggio. The painting, undisclosed until now, hides an underlying female portrait. The authors investigate both compositions from a technical, iconographical and critical point of view, supporting Caravaggio's attribution. The technical researches allow cross-validation in the brushwork and materials of the picture, compared to Caravaggio's early painting technique and style. The portrait of Maffeo Barberini, recently re-ascribed to Caravaggio, shows a significant similarity, while the underlying woman of the retrieved painting closely resembles the gipsy of the Louvre Fortune Teller. In addition, a newly introduced and advanced imaging technique (MaXRF) has detected on the male portrait the feature of the lawyer's robe, which supports the identification with Prospero Farinacci. The intriguing topic of physiognomic accuracy versus stylizing tendency in Caravaggio's portraiture is considered with the aid of Giulio Mancini's observations. Besides, the possible interpretation of the underlying figure as a religious subject sheds a light on the obscure activity of the young Caravaggio in Lorenzo Carli's workshop, recently brought to scholars' attention by new documents and hypotheses.
Keywords: A1 Journal article; Art; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
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“Trace-level micro-XANES by means of bending magnets radiation focused with a polycapillary lens”. Vincze L, Janssens K, Wei F, Proost K, Vekemans B, Vittiglio G, Yan Y, Falkenberg G (1999).
Keywords: H3 Book chapter; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
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“Two fragments of mold-blown glass beakers with Greek inscriptions from Tongeren (Belgium)”. Cosyns P, Vanderhoeven A, Vynckier G, Janssens K, Schalm O, Vanderlinden V, Journal of glass studies 47, 179 (2005)
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
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“Un verre méditerranéen pour la production de bracelets laténiens en Europe septentrionale : résultats danalyses SEM-EDX et LA-ICP-MS de bracelets en verre La Tène tardive de Odijk, Tiel et Geldermalseren-Hondsgemet”. Cosyns P, Cagno S, Janssens K, Nys K, Bulletin AFAV , 13 (2014)
Keywords: A3 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
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“Unique properties of core shell Ag@Au nanoparticles for the aptasensing of bacterial cells”. Hamidi-Asl E, Dardenne F, Pilehvar S, Blust R, De Wael K, Chemosensors 4, 16 (2016). http://doi.org/10.3390/CHEMOSENSORS4030016
Abstract: In this article, it is shown that the efficiency of an electrochemical aptasensing device is influenced by the use of different nanoparticles (NPs) such as gold nanoparticles (Au), silver nanoparticles (Ag), hollow gold nanospheres (HGN), hollow silver nanospheres (HSN), silvergold core shell (Ag@Au), goldsilver core shell (Au@Ag), and silvergold alloy nanoparticles (Ag/Au). Among these nanomaterials, Ag@Au core shell NPs are advantageous for aptasensing applications because the core improves the physical properties and the shell provides chemical stability and biocompatibility for the immobilization of aptamers. Self-assembly of the NPs on a cysteamine film at the surface of a carbon paste electrode is followed by the immobilization of thiolated aptamers at these nanoframes. The nanostructured (Ag@Au) aptadevice for Escherichia coli as a target shows four times better performance in comparison to the response obtained at an aptamer modified planar gold electrode. A comparison with other (core shell) NPs is performed by cyclic voltammetry and differential pulse voltammetry. Also, the selectivity of the aptasensor is investigated using other kinds of bacteria. The synthesized NPs and the morphology of the modified electrode are characterized by UV-Vis absorption spectroscopy, scanning electron microscopy, energy dispersive X-ray analysis, and electrochemical impedance spectroscopy.
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Times cited: 9
DOI: 10.3390/CHEMOSENSORS4030016
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“The use of focussed X-ray beams for non-destructive characterization of historical materials: from elemental trace analysis towards chemical state investigations”. Janssens K, Proost K, Deraedt I, Bulska E, Wagner B, Schreiner M, , 193 (2003)
Keywords: P1 Proceeding; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
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“The use of full-field XRF for simultaneous elemental mapping”. Alfeld M, Janssens K, Sasov A, Liu X, Kostenko A, Rickers-Appel K, Falkenberg G, , 111 (2010). http://doi.org/10.1063/1.3399236
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.
Keywords: P1 Proceeding; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Times cited: 8
DOI: 10.1063/1.3399236
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De Vis K, Jacobs P, Caen J, Janssens K (2010) The use of glass bricks in architecture in the 19th and 20th centuries : a case study. 194–201
Keywords: P2 Proceeding; Engineering sciences. Technology; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
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“The use of scanning X-ray microprobe for simultaneous XRF/XRD studies of fly-ash particles”. Rindby A, Engström P, Janssens K, Journal of synchotron radiation 4, 228 (1997)
Keywords: A3 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
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“The use of synchrotron micro-XRF for characterisation of the micro-heterogeneity of low-Z reference materials containing heavy metals”. Kempenaers L, Vincze L, Janssens K (1999).
Keywords: H3 Book chapter; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
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“Van Gogh's Irises and Roses : the contribution of chemical analyses and imaging to the assessment of color changes in the red lake pigments”. Centeno SA, Hale C, Caro F, Cesaratto A, Shibayama N, Delaney J, Dooley K, van der Snickt G, Janssens K, Stein SA, Heritage science 5, 18 (2017). http://doi.org/10.1186/S40494-017-0131-8
Abstract: Vincent van Gogh's still lifes Irises and Roses were investigated to shed light onto the degree to which the paintings had changed, both individually and in relation to each other since they were painted, particularly in regard to the fading of the red lakes. Non-invasive techniques, including macroscopic X-ray fluorescence mapping, reflectance imaging spectroscopy, and X-radiography, were combined with microanalytical techniques in a select number of samples. The in-depth microchemical analysis was necessary to overcome the complications that arise when evaluating by non-invasive methods alone the compositions of passages with complex layering and mixing of paints. The results obtained by these two approaches were complemented by color measurements performed on paint cross-sections and on protected edges, and with historical information provided by the artist's own descriptions, early reviews and reproductions, and the data was used to carry out digital color simulations that provided, to a certain extent, a visualization of how the paintings may have originally appeared.
Keywords: A1 Journal article; Art; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Times cited: 21
DOI: 10.1186/S40494-017-0131-8
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“Virtual underpainting reconstruction from X-ray fluorescence imaging data”. Anitha A, Brasoveanu A, Duarte MF, Hughes SM, Daubechies I, Dik J, Janssens K, Alfeld M, , 1239 (2011)
Keywords: P1 Proceeding; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
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“Water quality assessment in Pangani river basin, Tanzania : natural and anthropogenic influences on concentrations of nutrients and inorganic ions”. Hellar-Kihampa H, De Wael K, Lugwisha E, Van Grieken R, International journal of river basin management 11, 55 (2013). http://doi.org/10.1080/15715124.2012.759119
Abstract: The ongoing rapid expansions of human activities and population dynamics have potential impact on the environmental quality of the Pangani river basin, one of the largest water resources in Tanzania, including possible loadings of different kinds of micro-contaminants. However, specific extents of the impacts are rather not well investigated. In this work, we assessed the environmental quality of the basin, based on seasonal characterisation of physicochemical water and sediments parameters, dissolved inorganic ions and nutrient loads. The contributions of geochemical processes and land-use practices were evaluated by multivariate correlations and principal component analysis (PCA). Hierarchical cluster analysis was used to classify similar water quality stations and identify the most and least enriched ones. Surface waters were slightly alkaline, characterised by low total dissolved solids (48652 mg/L). Extremely low oxygen concentration (2.0 mg/L) was also a cause of concern at one station. The Na+ and HCO3 − ions provided the dominant cation and anion, respectively. PCA identified weathering of carbonate and Na+ bearing rocks, gypsum dissolution and atmospheric deposition of sea-salt as the major factors controlling the ionic composition, contributing more than 60% of the spatial variance. Concentration profiles of the chemical species showed a generally low level of anthropogenic inputs, except at a few locations where nitrate and nitrite were significantly enriched above the limits of safe exposure, with patterns indicating influences of farming and livestock keeping. A seasonal difference was observed, with lower ion concentrations during the rainy season, likely due to the dilution effect of increased water discharge. The study provides new insights into the environmental quality of the basin, and indicates the need for continuous monitoring and assessment of the chemical species in the area.
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1080/15715124.2012.759119
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