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Author Gonzalez-Quiroga, A.; Shtern, V.; Perreault, P.; Vandewalle, L.; Marin, G.B.; Van Geem, K.M.
  Title Intensifying mass and heat transfer using a high-g stator-rotor vortex chamber Type A1 Journal article
  Year 2021 Publication Chemical Engineering And Processing Abbreviated Journal Chem Eng Process
  Volume 169 Issue Pages 108638-11
  Keywords A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL)
  Abstract Vortex reactors take advantage of the synergy between enhanced heat and mass transfer rates and multifunctional phenomena at different temporal and spatial scales. Proof-of-concept experiments with our novel and innovative STAtor-Rotor VOrtex Chamber (STARVOC) confirm its advantageous features for the sustainable production of chemicals and fuels. STARVOC is a high-g contactor that uses carrier flow (gas or liquid) tangential injection to drive a rotor attached to low-friction bearings. The vortex chamber inside the rotor contains a secondary phase or phases, such as a solids bed, a liquid layer, or a suspension. Carrier fluid passes through the perforated rotor wall and contacts a densely and uniformly distributed secondary phase with enhanced slip velocities. Experiments focused on pressure profiles, rotor angular velocity, and solids azimuthal velocity. With air as the carrier fluid and different solid particle beds as the secondary phase, STARVOC reached bed azimuthal velocities up to four-fold compared to those reached in Gas-Solid Vortex Units with fully static geometry. These results show its potential to improve interfacial heat and mass transfer rates and take advantage of flow energy and angular momentum. Due to its process intensification capabilities, STARVOC is a promising alternative for the state-of-the-art chemical industry.
  Address
  Corporate Author Thesis
  Publisher Place of Publication Editor
  Language Wos 000704946900008 Publication Date 2021-09-17
  Series Editor Series Title Abbreviated Series Title
  Series Volume Series Issue Edition
  ISSN (up) 0255-2701 ISBN Additional Links UA library record; WoS full record; WoS citing articles
  Impact Factor 2.234 Times cited Open Access Not_Open_Access
  Notes Approved Most recent IF: 2.234
  Call Number UA @ admin @ c:irua:181062 Serial 8111
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Author Bampouli, A.; Goris, Q.; Hussain, M.N.; Louisnard, O.; Stefanidis, G.D.; Van Gerven, T.
  Title Importance of design and operating parameters in a sonication system for viscous solutions : effects of input power, horn tip diameter and reactor capacity Type A1 Journal article
  Year 2024 Publication Chemical engineering and processing Abbreviated Journal
  Volume 198 Issue Pages 109715-12
  Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
  Abstract This study investigates the distribution of ultrasound (US) energy in a batch system for solutions with viscosity ranging from 1 to approximately 3000 mPas. Sonication was performed using horn type configurations operating at 20-30 kHz and rated power capacity of 50 or 200 W. Two different tip diameters (3 or 7 mm) and two insertion depths (35 or 25 mm) within vessels of different sizes ( approximate to 60 or 130 ml) were utilized. Additionally, a special conical tip design was employed. For each experimental setup, the calorimetric efficiency was estimated, the cavitationally active regions were visualized using the sonochemiluminescence (SCL) method and bubble cluster formation inside the vessel was macroscopically observed using a high speed camera (HSC). In the viscosity range tested, the calorimetry results showed that the efficiency and continuous operation of the device depend on both the rated power and the horn tip diameter. The ratio between electrical and calorimetric power input remained consistently around 40 to 50% across the different configurations for water, but for the 123.2 mPas solution exhibited significant variation ranging from 40 to 85%. Moreover, the power density in the smaller reactor was found to be nearly double compared to the larger one. The SCL analysis showed multiple cavitationally active zones in all setups, and the zones intensity decreased considerably with increase of the solutions viscosity. The results for the cone tip were not conclusive, but can be used as the basis for further investigation. The current research highlights the importance of thoroughly understanding the impact of each design parameter, and of establishing characterization methodologies to assist in the future development of scaled-up, commercial applications.
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  Corporate Author Thesis
  Publisher Place of Publication Editor
  Language Wos 001218630800001 Publication Date 2024-02-21
  Series Editor Series Title Abbreviated Series Title
  Series Volume Series Issue Edition
  ISSN (up) 0255-2701 ISBN Additional Links UA library record; WoS full record
  Impact Factor 4.3 Times cited Open Access
  Notes Approved Most recent IF: 4.3; 2024 IF: 2.234
  Call Number UA @ admin @ c:irua:206003 Serial 9154
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Author Veljkovic, D.; Tadić, M.; Peeters, F.M.
  Title Intersublevel absorption in stacked n-type doped self-assembled quantum dots Type A1 Journal article
  Year 2005 Publication Materials science forum Abbreviated Journal Mater Sci Forum
  Volume 494 Issue Pages 37-42
  Keywords A1 Journal article; Condensed Matter Theory (CMT)
  Abstract The intersublevel absorption in n-doped InAs/GaAs self-assembled quantum-dot molecules composed of three quantum dots is theoretically considered. The transition matrix elements and the transition energies are found to vary considerably with the spacer thickness. For s polarized light, decreasing the thickness of the spacer between the dots brings about crossings between the transition matrix elements, but the overall absorption is not affected by the variation of the spacer thickness. For p-polarized light and thick spacers, there are no available transitions in the single quantum dot, but a few of them emerge as a result of the electron state splitting in the stacks of coupled quantum dots, which leads to a considerable increase of the transition matrix elements, exceeding by an order of magnitude values of the matrix elements for s-polarized light.
  Address
  Corporate Author Thesis
  Publisher Place of Publication Lausanne Editor
  Language Wos Publication Date 0000-00-00
  Series Editor Series Title Abbreviated Series Title
  Series Volume Series Issue Edition
  ISSN (up) 0255-5476; 1662-9752 ISBN Additional Links UA library record; WoS full record;
  Impact Factor Times cited Open Access
  Notes Approved Most recent IF: NA
  Call Number UA @ lucian @ c:irua:94746 Serial 1715
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Author Partoens, B.; Matulis, A.; Peeters, F.M.
  Title Magnetoplasma excitations in vertically coupled quantum dot systems Type A1 Journal article
  Year 1999 Publication Materials science forum Abbreviated Journal Mater Sci Forum
  Volume 297/298 Issue Pages 225-228
  Keywords A1 Journal article; Condensed Matter Theory (CMT)
  Abstract
  Address
  Corporate Author Thesis
  Publisher Place of Publication Lausanne Editor
  Language Wos 000080081600043 Publication Date 0000-00-00
  Series Editor Series Title Abbreviated Series Title
  Series Volume Series Issue Edition
  ISSN (up) 0255-5476; 1662-9752 ISBN Additional Links UA library record; WoS full record;
  Impact Factor Times cited Open Access
  Notes Approved Most recent IF: NA
  Call Number UA @ lucian @ c:irua:24176 Serial 1920
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Author Cremers, V.; Rampelberg, G.; Barhoum, A.; Walters, P.; Claes, N.; Oliveira, T.M. de; Assche, G.V.; Bals, S.; Dendooven, J.; Detavernier, C.
  Title Oxidation barrier of Cu and Fe powder by Atomic Layer Deposition Type A1 Journal article
  Year 2018 Publication Surface and coatings technology Abbreviated Journal Surf Coat Tech
  Volume 349 Issue 349 Pages 1032-1041
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
  Abstract Atomic layer deposition (ALD) is a vapor based technique which allows to deposit uniform, conformal films with a thickness control at the atomic scale. In this research, Al 2 O 3 coatings were deposited on micrometer-sized Fe and Cu powder (particles) using the thermal trimethylaluminum (TMA)/ water (H 2 O) process in a rotary pump-type ALD reactor. Rotation of the powder during deposition was required to obtain a pinhole-free ALD coating. The protective nature of the coating was evaluated by quantifying its effectiveness in protecting the metal particles during oxidative annealing treatments. The Al 2 O 3 coated powders were annealed in ambient air while in-situ thermogravimetric analysis (TGA) and in-situ x-ray diffraction (XRD) data were acquired. The thermal stability of a series of Cu and Fe powder with different Al 2 O 3 thicknesses were determined with TGA. In both samples a clear shift in oxidation temperature is visible. For Cu and Fe powder coated with 25 nm Al 2 O 3 , we observed an increase of the oxidation temperature with 300-400°C. For the Cu powder a thin film of only 8 nm is required to obtain an initial increase in oxidation temperature of 200°C. In contrast, for Fe powder a thicker coating of 25 nm is required. In both cases, the oxidation temperature increases with increasing thickness of the Al 2 O 3 coating. These results illustrate that the Al 2 O 3 thin film, deposited by the thermal ALD process (TMA/H 2 O) can be an efficient and pinhole-free barrier layer for micrometer-sized powder particles, provided that the powder is properly agitated during the process to ensure sufficient vapour-solid interaction.
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  Corporate Author Thesis
  Publisher Place of Publication Editor
  Language Wos 000441492600108 Publication Date 2018-06-25
  Series Editor Series Title Abbreviated Series Title
  Series Volume Series Issue Edition
  ISSN (up) 0257-8972 ISBN Additional Links UA library record; WoS full record; WoS citing articles
  Impact Factor 2.589 Times cited 10 Open Access OpenAccess
  Notes The authors acknowledge financial support from the Strategic Initiative Materials in Flanders (SIM, SBO-FUNC project) and the Special Research Fund BOF of Ghent University (GOA 01G01513). J. D. acknowledges the Research Foundation Flanders (FWO-Vlaanderen) for a postdoctoral fellowship. N.C. and S.B. acknowledge financial support from European Research Council (ERC Starting Grant 335078-COLOURATOMS). The authors acknowledge S. Goeteyn for the assistance in preliminary depositions. (ROMEO:green; preprint:; postprint:can ; pdfversion:cannot); ecas_sara Approved Most recent IF: 2.589
  Call Number EMAT @ emat @c:irua:152174UA @ admin @ c:irua:152174 Serial 4994
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Author Sharp, J.; Mueller, I.C.; Mandal, P.; Abbas, A.; Nord, M.; Doye, A.; Ehiasarian, A.; Hovsepian, P.; MacLaren, I.; Rainforth, W.M.
  Title Characterisation of a high-power impulse magnetron sputtered C/Mo/W wear resistant coating by transmission electron microscopy Type A1 Journal article
  Year 2019 Publication Surface and coatings technology Abbreviated Journal Surf Coat Tech
  Volume 377 Issue 377 Pages 124853
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
  Abstract Thin films of C/Mo/W deposited using combined UBM/HIPIMS sputtering show 2-8 nm clusters of material richer in Mo and W than the matrix (found by EDS microanalysis), with structures that resemble graphitic onions with the metal atoms arranged regularly within them. EELS microanalysis showed the clusters to be rich in W and Mo. As the time averaged power used in the pulsed HIPIMS magnetron was increased, the clusters became more defined, larger, and arranged into layers with amorphous matrix between them. Films deposited with average HIPIMS powers of 4 kW and 6 kW also showed a periodic modulation of the cluster density within the finer layers giving secondary, wider stripes in TEM. By analysing the ratio between the finer and coarser layers, it was found that this meta-layering is related to the substrate rotation in the deposition chamber but in a non-straightforward way. Reasons for this are proposed. The detailed structure of the clusters remains unknown and is the subject of further work. Fluctuation electron microscopy results indicated the presence of crystal planes with the graphite interlayer spacing, crystal planes in hexagonal WC perpendicular to the basal plane, and some plane spacings found in Mo2C. Other peaks in the FEM results suggested symmetry-related starting points for future determination of the structure of the clusters.
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  Corporate Author Thesis
  Publisher Place of Publication Editor
  Language Wos 000488417800015 Publication Date 2019-08-03
  Series Editor Series Title Abbreviated Series Title
  Series Volume Series Issue Edition
  ISSN (up) 0257-8972 ISBN Additional Links UA library record; WoS full record; WoS citing articles
  Impact Factor 2.589 Times cited 1 Open Access
  Notes ; J.S. thanks the Mercury Centre at the University of Sheffield for funding, which was part funded by the ERDF under grant MERCURY 904467. I.C.M. acknowledges support from CONACyT and RobertoRocca Education Fellowship. We gratefully acknowledge funding from EPSRC for the pixelated STEM detector and the software used in its operation for the fluctuation microscopy (EP/M009963/ 1, EP/K503903/1 & EP/R511705/1). AD was supported by the EPSRC CDT in Integrative Sensing and Measurement, Grant Number EP/L016753/1. Funding sources did not influence the planning or execution of this work except to enable it. ; Approved Most recent IF: 2.589
  Call Number UA @ admin @ c:irua:163700 Serial 5383
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Author Major, L.; Morgiel, J.; Major, B.; Lackner, J.M.; Waldhauser, W.; Ebner, R.; Nistor, L.; Van Tendeloo, G.
  Title Crystallographic aspects related to advanced tribological multilayers of Cr/CrN and Ti/TiN types produced by pulsed laser deposition (PLD) Type A1 Journal article
  Year 2006 Publication Surface and coatings technology Abbreviated Journal Surf Coat Tech
  Volume 200 Issue 22/23 Pages 6190-6195
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
  Abstract
  Address
  Corporate Author Thesis
  Publisher Place of Publication Lausanne Editor
  Language Wos 000237842300007 Publication Date 2005-12-10
  Series Editor Series Title Abbreviated Series Title
  Series Volume Series Issue Edition
  ISSN (up) 0257-8972; ISBN Additional Links UA library record; WoS full record; WoS citing articles
  Impact Factor 2.589 Times cited 32 Open Access
  Notes Approved Most recent IF: 2.589; 2006 IF: 1.559
  Call Number UA @ lucian @ c:irua:59459 Serial 586
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Author Neyts, E.; Bogaerts, A.; de Meyer, M.; van Gils, S.
  Title Macroscale computer simulations to investigate the chemical vapor deposition of thin metal-oxide films Type A1 Journal article
  Year 2007 Publication Surface and coatings technology Abbreviated Journal Surf Coat Tech
  Volume 201 Issue 22/23 Pages 8838-8841
  Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
  Abstract
  Address
  Corporate Author Thesis
  Publisher Place of Publication Lausanne Editor
  Language Wos 000249340400008 Publication Date 2007-05-02
  Series Editor Series Title Abbreviated Series Title
  Series Volume Series Issue Edition
  ISSN (up) 0257-8972; ISBN Additional Links UA library record; WoS full record; WoS citing articles
  Impact Factor 2.589 Times cited 5 Open Access
  Notes Approved Most recent IF: 2.589; 2007 IF: 1.678
  Call Number UA @ lucian @ c:irua:64790 Serial 1859
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Author Bogaerts, A.; de Bleecker, K.; Kolev, I.; Madani, M.
  Title Modeling of gas discharge plasmas: What can we learn from it? Type A1 Journal article
  Year 2005 Publication Surface and coatings technology Abbreviated Journal Surf Coat Tech
  Volume 200 Issue Pages 62-67
  Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
  Abstract
  Address
  Corporate Author Thesis
  Publisher Place of Publication Lausanne Editor
  Language Wos 000232327800014 Publication Date 2005-03-22
  Series Editor Series Title Abbreviated Series Title
  Series Volume Series Issue Edition
  ISSN (up) 0257-8972; ISBN Additional Links UA library record; WoS full record; WoS citing articles
  Impact Factor 2.589 Times cited 11 Open Access
  Notes Approved Most recent IF: 2.589; 2005 IF: 1.646
  Call Number UA @ lucian @ c:irua:53629 Serial 2122
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Author Huq, M.Z.; Celis, J.P.; Meneve, J.; Stals, L.; Schryvers, D.
  Title Oscillating sliding wear of mono- and multilayer ceramic coatings in air Type A1 Journal article
  Year 1999 Publication Surface and coatings technology Abbreviated Journal Surf Coat Tech
  Volume 113 Issue Pages 242-250
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
  Abstract
  Address
  Corporate Author Thesis
  Publisher Place of Publication Lausanne Editor
  Language Wos 000079807600007 Publication Date 2002-07-25
  Series Editor Series Title Abbreviated Series Title
  Series Volume Series Issue Edition
  ISSN (up) 0257-8972; ISBN Additional Links UA library record; WoS full record; WoS citing articles
  Impact Factor 2.589 Times cited 10 Open Access
  Notes Approved Most recent IF: 2.589; 1999 IF: 1.008
  Call Number UA @ lucian @ c:irua:29379 Serial 2532
Permanent link to this record
 

 
Author Zhou, C.; Ji, G.; Chen, Z.; Wang, M.; Addad, A.; Schryvers, D.; Wang, H.
  Title Fabrication, interface characterization and modeling of oriented graphite flakes/Si/Al composites for thermal management applications Type A1 Journal article
  Year 2014 Publication Materials and design Abbreviated Journal Mater Design
  Volume 63 Issue Pages 719-728
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
  Abstract Highly thermally conductive graphite flakes (Gf)/Si/Al composites have been fabricated using Gf, Si powder and an AlSi7Mg0.3 alloy by an optimized pressure infiltration process for thermal management applications. In the composites, the layers of Gf were spaced apart by Si particles and oriented perpendicular to the pressing direction, which offered the opportunity to tailor the thermal conductivity (TC) and coefficient of thermal expansion (CTE) of the composites. Microstructural characterization revealed that the formation of a clean and tightly-adhered interface at the nanoscale between the side surface of the Gf and Al matrix, devoid of a detrimental Al4C3 phase and a reacted amorphous AlSiOC layer, contributed to excellent thermal performance along the alignment direction. With increasing volume fraction of Gf from 13.7 to 71.1 vol.%, the longitudinal (i.e. parallel to the graphite layers) TC of the composites increased from 179 to 526 W/m K, while the longitudinal CTE decreased from 12.1 to 7.3 ppm/K (matching the values of electronic components). Furthermore, the modified layers-in-parallel model better fitted the longitudinal TC data than the layers-in-parallel model and confirmed that the clean and tightly-adhered interface is favorable for the enhanced longitudinal TC.
  Address
  Corporate Author Thesis
  Publisher Place of Publication Reigate Editor
  Language Wos 000340949300086 Publication Date 2014-07-17
  Series Editor Series Title Abbreviated Series Title
  Series Volume Series Issue Edition
  ISSN (up) 0261-3069; ISBN Additional Links UA library record; WoS full record; WoS citing articles
  Impact Factor Times cited 61 Open Access
  Notes Approved Most recent IF: NA
  Call Number UA @ lucian @ c:irua:118124 Serial 1166
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Author Barhoum, A.; Van Assche, G.; Rahier, H.; Fleisch, M.; Bals, S.; Delplancked, M.-P.; Leroux, F.; Bahnemann, D.
  Title Sol-gel hot injection synthesis of ZnO nanoparticles into a porous silica matrix and reaction mechanism Type A1 Journal article
  Year 2017 Publication Materials & design Abbreviated Journal Mater Design
  Volume 119 Issue 119 Pages 270-276
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
  Abstract Despite the enormous interest in the properties and applications of porous silica matrix, only a few attempts have been reported to deposit metal and metal oxide nanoparticles (NPs) inside the porous silica matrix. We report a simple approach (i.e. sol-gel hot injection) for insitu synthesis of ZnO NPs inside a porous silica matrix. Control of the Zn:Si molar ratio, reaction temperature, pH value, and annealing temperature permits formation of ZnO NPs (<= 10 nm) inside a porous silica particles, without additives or organic solvents. Results revealed that a solid state reaction inside the ZnO/SiO2 nanocomposites occurs with increasing the annealing temperature. The reaction of ZnO NPs with SiO2 matrix was insignificant up to approximately 500 degrees C. However, ZnO NPs react strongly with the silica matrix when the nanocomposites are annealed at temperatures above 700 degrees C. Extensive annealing of the ZnO/SiO2 nanocomposite at 900 degrees C yields 3D structures made of 500 nm rod-like, 5-7 pm tube-like and 35 pm needle-like Zn2SiO4 crystals. A possible mechanism for forming ZnO NPs inside porous silica matrix and phase transformation of the ZnO/SiO2 nanocomposites into 3D architectures of Zn2SiO4 are carefully discussed. (C) 2017 Elsevier Ltd. All rights reserved.
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  Corporate Author Thesis
  Publisher Place of Publication Editor
  Language Wos 000397360000030 Publication Date 2017-01-23
  Series Editor Series Title Abbreviated Series Title
  Series Volume Series Issue Edition
  ISSN (up) 0264-1275 ISBN Additional Links UA library record; WoS full record; WoS citing articles
  Impact Factor 4.364 Times cited 43 Open Access Not_Open_Access
  Notes ; A.B. would like to thank FWO – Research Foundation Flanders (grant no. V450315N) and the Strategic Initiative Materials in Flanders (SBO-project no. 130529 – INSITU) for financial support. TEM and TEM-EDX analyses were performed by Dr. F. Leroux (EMAT, Universiteit Antwerpen). XRD and DSC measurements were performed by T. Segato (4MAT, Universite Libre de Bruxelles). Notes: the authors declare no competing for financial interest. ; Approved Most recent IF: 4.364
  Call Number UA @ lucian @ c:irua:142394UA @ admin @ c:irua:142394 Serial 4689
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Author Radi, A.; Khalil-Allafi, J.; Etminanfar, M.R.; Pourbabak, S.; Schryvers, D.; Amin-Ahmadi, B.
  Title Influence of stress aging process on variants of nano-N4Ti3precipitates and martensitic transformation temperatures in NiTi shape memory alloy Type A1 Journal article
  Year 2018 Publication Materials & design Abbreviated Journal Mater Design
  Volume 262 Issue 262 Pages 74-81
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
  Abstract In this study, the effect of a stress aging process on the microstructure and martensitic phase transformation of NiTi shape memory alloy has been investigated. NiTi samples were aged at 450 degrees C for 1 h and 5 h under different levels of external tensile stress of 15, 60 and 150 MPa. Transmission electron microscopy (TEM) was used to characterize different variants and morphology of precipitates. The results show that application of all stress levels restricts the formation of precipitates variants in the microstructure after I h stress aging process. However, all variants can be detected by prolonging aging time to 5 h at 15 MPa stress level and the variants formation is again restricted by increasing the stress level. Moreover, the stress aging process resulted in changing the shape of precipitates in comparison with that of the stress-free aged samples. Coffee-bean shaped morphologies were detected for precipitates in all stress levels. According to the Differential Scanning Calorimetry (DSC) results, the martensite start temperature (M-s) on cooling shifts to higher temperatures with increasing the tensile stress during the aging process. This can be related to the change ofaustenite to martensite interface energy due to the different volume fractions and variants of precipitates. (c) 2018 Elsevier Ltd. All rights reserved.
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  Corporate Author Thesis
  Publisher Place of Publication Editor
  Language Wos Publication Date 2018-01-04
  Series Editor Series Title Abbreviated Series Title
  Series Volume Series Issue Edition
  ISSN (up) 0264-1275 ISBN Additional Links UA library record; ; WoS full record; WoS citing articles
  Impact Factor 4.364 Times cited Open Access OpenAccess
  Notes Approved Most recent IF: 4.364
  Call Number UA @ lucian @ c:irua:149854 Serial 4938
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Author Montero-Sistiaga, M.L.; Pourbabak, S.; Van Humbeeck, J.; Schryvers, D.; Vanmeensel, K.
  Title Microstructure and mechanical properties of Hastelloy X produced by HP-SLM (high power selective laser melting) Type A1 Journal article
  Year 2019 Publication Materials & design Abbreviated Journal Mater Design
  Volume 165 Issue Pages 107598
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
  Abstract In order to increase the production rate during selective laser melting (SLM), a high power laser with a large beam diameter is used to build fully dense Hastelloy X parts. Compared to SLM with a low power and small diameter beam, the productivity was increased from 6 mm3/s to 16 mm3/s, i.e. 2.6 times faster. Besides the productivity benefit, the influence of the use of a high power laser on the rapid solidification microstructure and concomitant material properties is highlighted. The current paper compares the microstructure and tensile properties of Hastelloy X built with low and high power lasers. The use of a high power laser results in wider and shallower melt pools inducing an enhanced morphological and crystallographic texture along the building direction (BD). In addition, the increased heat input results in coarser sub-grains or high density dislocation walls for samples processed with a high power laser. Additionally, the influence of hot isostatic pressing (HIP) as a post-processing technique was evaluated. After HIP, the tensile fracture strain increased as compared to the strain in the as-built state and helped in obtaining competitive mechanical properties as compared to conventionally processed Hastelloy X parts.
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  Corporate Author Thesis
  Publisher Place of Publication Editor
  Language Wos 000458259300020 Publication Date 2019-01-09
  Series Editor Series Title Abbreviated Series Title
  Series Volume Series Issue Edition
  ISSN (up) 0264-1275 ISBN Additional Links UA library record; WoS full record; WoS citing articles
  Impact Factor 4.364 Times cited 15 Open Access OpenAccess
  Notes This research was supported by the ENGIE Research and Technology Division. The authors acknowledge ENGIE Research and Technology Division for the use of the SLM280HL machine. S.P. likes to thank the Flemish Science Foundation FWO for financial support under Project G.0366.15N. Approved Most recent IF: 4.364
  Call Number EMAT @ emat @UA @ admin @ c:irua:157469 Serial 5176
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Author Bignoli, F.; Rashid, S.; Rossi, E.; Jaddi, S.; Djemia, P.; Terraneo, G.; Li Bassi, A.; Idrissi, H.; Pardoen, T.; Sebastiani, M.; Ghidelli, M.
  Title Effect of annealing on mechanical properties and thermal stability of ZrCu/O nanocomposite amorphous films synthetized by pulsed laser deposition Type A1 Journal article
  Year 2022 Publication Materials & design Abbreviated Journal Mater Design
  Volume 221 Issue Pages 110972-10
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
  Abstract Binary ZrCu nanocomposite amorphous films are synthetized by pulsed laser deposition (PLD) under vac-uum (2 x 10-3 Pa) and 10 Pa He pressure, leading to fully amorphous compact and nanogranular mor-phologies, respectively. Then, post-thermal annealing treatments are carried out to explore thermal stability and crystallization phenomena together with the evolution of mechanical properties. Compact films exhibit larger thermal stability with partial crystallization phenomena starting at 420 degrees C, still to be completed at 550 degrees C, while nanogranular films exhibit early-stage crystallization at 300 degrees C and com-pleted at 485 degrees C. The microstructural differences are related to a distinct evolution of mechanical
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  Corporate Author Thesis
  Publisher Place of Publication Editor
  Language Wos 000886072100004 Publication Date 2022-07-21
  Series Editor Series Title Abbreviated Series Title
  Series Volume Series Issue Edition
  ISSN (up) 0264-1275; 1873-4197 ISBN Additional Links UA library record; WoS full record; WoS citing articles
  Impact Factor 8.4 Times cited Open Access OpenAccess
  Notes Approved Most recent IF: 8.4
  Call Number UA @ admin @ c:irua:192194 Serial 7299
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Author Kashiwar, A.; Arseenko, M.; Simar, A.; Idrissi, H.
  Title On the role of microstructural defects on precipitation, damage, and healing behavior in a novel Al-0.5Mg2Si alloy Type A1 Journal article
  Year 2024 Publication Materials & design Abbreviated Journal
  Volume 239 Issue Pages 112765-112769
  Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
  Abstract A recently developed healable Al-Mg2Si designed by the programmed damage and repair (PDR) strategy is studied considering the role microstructural defects play on precipitation, damage, and healing. The alloy incorporates sacrificial Mg2Si particles that precipitate after friction stir processing (FSP). They act as damage localization sites and are healable based on the solid-state diffusion of Al-matrix. A combination of different transmission electron microscopy (TEM) imaging techniques enabled the visualization and quantification of various crystallographic defects and the spatial distribution of Mg2Si precipitates. Intragrain nucleation is found to be the dominant mechanism for precipitation during FSP whereas grain boundaries and subgrain boundaries mainly lead to coarsening of the precipitates. The statistical and spatial analyses of the damaged particles have shown particle fracture as the dominant damage mechanism which is strongly dependent on the size and aspect ratio of the particles whereas the damage was not found to depend on the location of the precipitates within the matrix. The damaged particles are associated with dislocations accumulated around them. The interplay of these dislocations is directly visualized during healing based on in situ TEM heating which revealed recovery in the matrix as an operative mechanism during the diffusion healing of the PDR alloy.
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  Corporate Author Thesis
  Publisher Place of Publication Editor
  Language Wos 001194110200001 Publication Date 2024-02-17
  Series Editor Series Title Abbreviated Series Title
  Series Volume Series Issue Edition
  ISSN (up) 0264-1275; 1873-4197 ISBN Additional Links UA library record; WoS full record
  Impact Factor 8.4 Times cited Open Access Not_Open_Access
  Notes Approved Most recent IF: 8.4; 2024 IF: 4.364
  Call Number UA @ admin @ c:irua:203298 Serial 9068
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Author Cagno, S.; Lind, O.C.; Popic, J.M.; Skipperud, L.; De Nolf, W.; Nuyts, G.; Vanmeert, F.; Jaroszewicz, J.; Janssens, K.; Salbu, B.
  Title Micro-analytical characterization of thorium-rich aggregates from Norwegian NORM sites (Fen Complex, Telemark) Type A1 Journal article
  Year 2020 Publication Journal Of Environmental Radioactivity Abbreviated Journal J Environ Radioactiv
  Volume 219 Issue Pages 106273
  Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
  Abstract In this study we performed microscopic characterization of mineral particles that were collected in the thorium-rich Fen Complex in Norway and identified and isolated based on autoradiography in function of their radioactivity. For this we combined information obtained with X-ray absorption mu-CT, mu-XRF and mu-XRD, both in bi- and in three-dimensional (tomographic) mode. We demonstrate that radionuclides and metals are heterogeneously distributed both within soil samples and within individual Th-enriched aggregates, which are characterised as low-density mineral bulk particles with high density material inclusions, where Th as well as several metals are highly concentrated. For these sites, it is important to take into account how these inhomogeneous distributions could affect the overall environmental behaviour of Th and progeny upon weathering due to human or environmental factors. Moreover, the estimated size of the Th-containing inclusions as determined in this work represents information of importance for the characterization of radionuclides and toxic metals exposure, as well as for assessing the viability of mining for Th and rare-earth metals in the Fen Complex and the associated environmental impact.
  Address
  Corporate Author Thesis
  Publisher Place of Publication Editor
  Language Wos 000535130500005 Publication Date 2020-04-27
  Series Editor Series Title Abbreviated Series Title
  Series Volume Series Issue Edition
  ISSN (up) 0265-931x ISBN Additional Links UA library record; WoS full record; WoS citing articles
  Impact Factor 2.3 Times cited Open Access
  Notes Approved Most recent IF: 2.3; 2020 IF: 2.31
  Call Number UA @ admin @ c:irua:181195 Serial 8229
Permanent link to this record
 

 
Author Zeegers, M.T.; Kadu, A.; van Leeuwen, T.; Batenburg, K.J.
  Title ADJUST : a dictionary-based joint reconstruction and unmixing method for spectral tomography Type A1 Journal article
  Year 2022 Publication Inverse problems Abbreviated Journal Inverse Probl
  Volume 38 Issue 12 Pages 125002-125033
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
  Abstract Advances in multi-spectral detectors are causing a paradigm shift in x-ray computed tomography (CT). Spectral information acquired from these detectors can be used to extract volumetric material composition maps of the object of interest. If the materials and their spectral responses are known a priori, the image reconstruction step is rather straightforward. If they are not known, however, the maps as well as the responses need to be estimated jointly. A conventional workflow in spectral CT involves performing volume reconstruction followed by material decomposition, or vice versa. However, these methods inherently suffer from the ill-posedness of the joint reconstruction problem. To resolve this issue, we propose 'A Dictionary-based Joint reconstruction and Unmixing method for Spectral Tomography' (ADJUST). Our formulation relies on forming a dictionary of spectral signatures of materials common in CT and prior knowledge of the number of materials present in an object. In particular, we decompose the spectral volume linearly in terms of spatial material maps, a spectral dictionary, and the indicator of materials for the dictionary elements. We propose a memory-efficient accelerated alternating proximal gradient method to find an approximate solution to the resulting bi-convex problem. From numerical demonstrations on several synthetic phantoms, we observe that ADJUST performs exceedingly well compared to other state-of-the-art methods. Additionally, we address the robustness of ADJUST against limited and noisy measurement patterns. The demonstration of the proposed approach on a spectral micro-CT dataset shows its potential for real-world applications. Code is available at https://github.com/mzeegers/ADJUST.
  Address
  Corporate Author Thesis
  Publisher Place of Publication Editor
  Language Wos 000868885200001 Publication Date 2022-09-20
  Series Editor Series Title Abbreviated Series Title
  Series Volume Series Issue Edition
  ISSN (up) 0266-5611 ISBN Additional Links UA library record; WoS full record
  Impact Factor 2.1 Times cited Open Access Not_Open_Access
  Notes Approved Most recent IF: 2.1
  Call Number UA @ admin @ c:irua:191536 Serial 7280
Permanent link to this record
 

 
Author Alloul, A.; Van Kampen, W.; Cerruti, M.; Wittouck, S.; Pabst, M.; Weissbrodt, D.G.
  Title Exploring the role of antimicrobials in the selective growth of purple phototrophic bacteria through genome mining and agar spot assays Type A1 Journal article
  Year 2022 Publication Letters in applied microbiology Abbreviated Journal Lett Appl Microbiol
  Volume 75 Issue 5 Pages 1275-1285
  Keywords A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL)
  Abstract Purple non-sulphur bacteria (PNSB) are an emerging group of microbes attractive for applied microbiology applications such as wastewater treatment, plant biostimulants, microbial protein, polyhydroxyalkanoates and H-2 production. These photoorganoheterotrophic microbes have the unique ability to grow selectively on organic carbon in anaerobic photobioreactors. This so-called selectivity implies that the microbial community will have a low diversity and a high abundance of a particular PNSB species. Recently, it has been shown that certain PNSB strains can produce antimicrobials, yet it remains unclear whether these contribute to competitive inhibition. This research aimed to understand which type of antimicrobial PNSB produce and identify whether these compounds contribute to their selective growth. Mining 166 publicly-available PNSB genomes using the computational tool BAGEL showed that 59% contained antimicrobial encoding regions, more specifically biosynthetic clusters of bacteriocins and non-ribosomal peptide synthetases. Inter- and intra-species inhibition was observed in agar spot assays for Rhodobacter blasticus EBR2 and Rhodopseudomonas palustris EBE1 with inhibition zones of, respectively, 5.1 and 1.5-5.7 mm. Peptidomic analysis detected a peptide fragment in the supernatant (SVLQLLR) that had a 100% percentage identity match with a known non-ribosomal peptide synthetase with antimicrobial activity.
  Address
  Corporate Author Thesis
  Publisher Place of Publication Editor
  Language Wos 000837055500001 Publication Date 2022-07-29
  Series Editor Series Title Abbreviated Series Title
  Series Volume Series Issue Edition
  ISSN (up) 0266-8254 ISBN Additional Links UA library record; WoS full record
  Impact Factor 2.4 Times cited Open Access OpenAccess
  Notes Approved Most recent IF: 2.4
  Call Number UA @ admin @ c:irua:189519 Serial 7162
Permanent link to this record
 

 
Author Aghaei, M.; Bogaerts, A.
  Title Particle transport through an inductively coupled plasma torch: elemental droplet evaporation Type A1 Journal article
  Year 2016 Publication Journal of analytical atomic spectrometry Abbreviated Journal J Anal Atom Spectrom
  Volume 31 Issue 31 Pages 631-641
  Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
  Abstract We studied the transport of copper droplets through an inductively coupled plasma, connected to the sampling cone of a mass spectrometer, by means of a computational model. The sample droplets are followed until they become evaporated. They are inserted as liquid particles from the central inlet and the effects of injection position (i.e. “on” and “off” axis), droplet diameter, as well as mass loading flow rate are investigated. It is shown that more “on-axis” injection of the droplets leads to a more straight path line, so that the droplets move less in the radial direction and are evaporated more on the central axis, enabling a better sample transfer efficiency to the sampler cone. Furthermore, there are optimum ranges of diameters and flow rates, which guarantee the proper position of evaporation along the torch, i.e. not too early, so that the sample can get lost in the torch, and not too late, which reduces the chance of becoming ionized before reaching the sampler.
  Address
  Corporate Author Thesis
  Publisher Place of Publication Editor
  Language Wos 000372857300003 Publication Date 2015-07-07
  Series Editor Series Title Abbreviated Series Title
  Series Volume Series Issue Edition
  ISSN (up) 0267-9477 ISBN Additional Links UA library record; WoS full record; WoS citing articles
  Impact Factor 3.379 Times cited 21 Open Access
  Notes The authors are very grateful to H. Lindner for the many fundamental and fruitful discussions. They are also gratefully acknowledge nancial support from the Fonds voor Wetenschappelijk Onderzoek (FWO). Approved Most recent IF: 3.379
  Call Number c:irua:133240 Serial 4024
Permanent link to this record
 

 
Author Bogaerts, A.; Aghaei, M.
  Title Inductively coupled plasma-mass spectrometry: insights through computer modeling Type A1 Journal article
  Year 2017 Publication Journal of analytical atomic spectrometry Abbreviated Journal J Anal Atom Spectrom
  Volume 32 Issue 32 Pages 233-261
  Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
  Abstract In this tutorial review paper, we illustrate how computer modeling can contribute to a better insight in inductively coupled plasma-mass spectrometry (ICP-MS). We start with a brief overview on previous efforts, studying the fundamentals of the ICP and ICP-MS, with main focus on previous modeling activities. Subsequently, we explain in detail the model that we developed in previous years, and we show typical calculation results, illustrating the plasma characteristics, gas flow patterns and the sample transport, evaporation and ionization. We also present the effect of various experimental parameters, such as operating conditions, geometrical aspects and sample characteristics, to illustrate how modeling can help to elucidate the optimal conditions for improved analytical performance.
  Address
  Corporate Author Thesis
  Publisher Place of Publication Editor
  Language Wos 000395529800002 Publication Date 2016-12-07
  Series Editor Series Title Abbreviated Series Title
  Series Volume Series Issue Edition
  ISSN (up) 0267-9477 ISBN Additional Links UA library record; WoS full record; WoS citing articles
  Impact Factor 3.379 Times cited 14 Open Access OpenAccess
  Notes The authors are very grateful to H. Lindner for the initial model development and for the many interesting discussions. They also gratefully acknowledge nancial support from the Fonds voor Wetenschappelijk Onderzoek (FWO; Grant number 6713). The calculations were carried out using the Turing HPC infrastructure at the CalcUA core facility of the Universiteit Antwerpen (UAntwerpen), a division of the Flemish Supercomputer Center VSC, funded by the Hercules Foundation, the Flemish Government (department EWI) and the UAntwerpen. Approved Most recent IF: 3.379
  Call Number PLASMANT @ plasmant @ c:irua:140074 Serial 4416
Permanent link to this record
 

 
Author Silva, A.L.M.; Carvalho, M.L.; Janssens, K.; Veloso, J.F.C.A.
  Title A large area full-field EDXRF imaging system based on a THCOBRA gaseous detector Type A1 Journal article
  Year 2015 Publication Journal of analytical atomic spectrometry Abbreviated Journal J Anal Atom Spectrom
  Volume 30 Issue 2 Pages 343-352
  Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
  Abstract By taking advantage of the attractive features in terms of gain, position and energy resolution of the 2D-THCOBRA detector, a new large area Full-Field X-ray Fluorescence Imaging (FF-XRFI) system for EDXRF imaging applications was developed. The proposed FF-XRFI system has an active area of 10 x 10 cm(2) and can be used to examine macroscopic samples with a moderately good energy resolution (< 1.6 keV FWHM at 8 keV) and a suitable spatial resolution (similar to 500 mu m FWHM). This combination of characteristics allows us to record elemental distribution maps from the surface of different sample types by combining image and energy information. Two different approaches were used for X-ray optics, one based on a single pinhole and another based on a parallel multiple-hole collimator. To illustrate the system capabilities, some sample examples were imaged and studied.
  Address
  Corporate Author Thesis
  Publisher Place of Publication Editor
  Language Wos 000349145700003 Publication Date 2014-10-24
  Series Editor Series Title Abbreviated Series Title
  Series Volume Series Issue Edition
  ISSN (up) 0267-9477 ISBN Additional Links UA library record; WoS full record; WoS citing articles
  Impact Factor 3.379 Times cited 11 Open Access
  Notes ; The authors thank Stijn Legrand for acquisition of the MAXRF maps shown in Fig. 15. This work was partially supported by projects CERN/FP/123604/2011 FEDER, COMPETE and FCT (Lisbon) programs. A. L. M. Silva is supported by the QREN programme Mais Centro – Programa Operacional Regional do Centro, FEDER and COMPETE, through the project Biomaterials for Regenerative Medicine (CENTRO-07-ST24-FEDER-002030). ; Approved Most recent IF: 3.379; 2015 IF: 3.466
  Call Number UA @ admin @ c:irua:125297 Serial 5452
Permanent link to this record
 

 
Author Alfeld, M.; Pedroso, J.V.; van Hommes, M.E.; van der Snickt, G.; Tauber, G.; Blaas, J.; Haschke, M.; Erler, K.; Dik, J.; Janssens, K.
  Title A mobile instrument for in situ scanning macro-XRF investigation of historical paintings Type A1 Journal article
  Year 2013 Publication Journal of analytical atomic spectrometry Abbreviated Journal J Anal Atom Spectrom
  Volume 28 Issue 5 Pages 760-767
  Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
  Abstract Scanning macro-X-ray fluorescence analysis (MA-XRF) is rapidly being established as a technique for the investigation of historical paintings. The elemental distribution images acquired by this method allow for the visualization of hidden paint layers and thus provide insight into the artist's creative process and the painting's conservation history. Due to the lack of a dedicated, commercially available instrument the application of the technique was limited to a few groups that constructed their own instruments. We present the first commercially available XRF scanner for paintings, consisting of an X-ray tube mounted with a Silicon-Drift (SD) detector on a motorized stage to be moved in front of a painting. The scanner is capable of imaging the distribution of the main constituents of surface and sub-surface paint layers in an area of 80 by 60 square centimeters with dwell times below 10 ms and a lateral resolution below 100 mu m. The scanner features for a broad range of elements between Ti (Z = 22) and Mo (Z = 42) a count rate of more than 1000 counts per second (cps)?mass percent and detection limits of 100 ppm for measurements of 1 s duration. Next to a presentation of spectrometric figures of merit, the value of the technique is illustrated through a case study of a painting by Rembrandt's student Govert Flinck (1615-1660).
  Address
  Corporate Author Thesis
  Publisher Place of Publication Editor
  Language Wos 000317674200019 Publication Date 2013-03-22
  Series Editor Series Title Abbreviated Series Title
  Series Volume Series Issue Edition
  ISSN (up) 0267-9477 ISBN Additional Links UA library record; WoS full record; WoS citing articles
  Impact Factor 3.379 Times cited 106 Open Access
  Notes ; This research was supported by the Interuniversity Attraction Poles Programme – Belgian Science Policy (IUAP VI/16). The text also presents the 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. M. Alfeld receives a Ph. D. fellowship of the Research Foundation-Flanders (FWO). We thank J. Langerock for allowing us to examine the portable altar triptych shown in Fig. 5. ; Approved Most recent IF: 3.379; 2013 IF: 3.396
  Call Number UA @ admin @ c:irua:108517 Serial 5453
Permanent link to this record
 

 
Author Rouchon, V.; Pellizzi, E.; Duranton, M.; Vanmeert, F.; Janssens, K.
  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 (up) 0267-9477 ISBN Additional Links UA library record; WoS full record; WoS citing articles
  Impact Factor 3.379 Times cited 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
Permanent link to this record
 

 
Author Vermeulen, M.; Sanyova, J.; Janssens, K.; Nuyts, G.; De Meyer, S.; De Wael, K.
  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 (up) 0267-9477 ISBN Additional Links UA library record; WoS full record; WoS citing articles
  Impact Factor 3.379 Times cited 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
Permanent link to this record
 

 
Author Cagno, S.; Nuyts, G.; Bugani, S.; De Vis, K.; Schalm, O.; Caen, J.; Helfen, L.; Cotte, M.; Reischig, P.; Janssens, K.
  Title Evaluation of manganese-bodies removal in historical stained glass windows via SR-\mu-XANES/XRF and SR-\mu-CT Type A1 Journal article
  Year 2011 Publication Journal of analytical atomic spectrometry Abbreviated Journal J Anal Atom Spectrom
  Volume 26 Issue 12 Pages 2442-2451
  Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
  Abstract The speed and effectiveness of a conservation treatment used for stained glass windows have been investigated. Dark-coloured Mn-rich stains can be found in the alteration layer of ancient glass artefacts and cause the surface to turn brown/black: this phenomenon is known as Mn-browning or Mn-staining. While in glass manganese is present in the +II or +III oxidation states, in the Mn-rich bodies, manganese is in a higher oxidation state (+IV). In restoration practice, mildly reducing solutions are employed to eliminate the dark colour and restore the clear appearance of the glass. In this paper the effectiveness and side effects of the use of hydroxylamine hydrochloride for this purpose are assessed. Archaeological fragments of stained glass windows, dated to the 14th century and originating from Sidney Sussex College, Cambridge (UK), were examined by means of synchrotron radiation (SR) based microscopic X-ray Absorption Near-Edge Spectroscopy (μ-XANES) and microscopic X-Ray Fluorescence (μ-XRF) and with high resolution computed absorption tomography (μ-CT) before, during and after the treatment. The monitoring of the glass fragments during the treatment allows us to better understand the manner in which the process unfolds and its kinetics. The results obtained reveal that the hydroxylamine hydrochloride treatment is effective, but also that it has a number of unwanted side effects. These findings are useful for optimizing the time and other modalities of the Mn-reducing treatment as well as minimizing its unwanted results.
  Address
  Corporate Author Thesis
  Publisher Place of Publication Editor
  Language Wos 000297030400009 Publication Date 2011-10-11
  Series Editor Series Title Abbreviated Series Title
  Series Volume Series Issue Edition
  ISSN (up) 0267-9477 ISBN Additional Links UA library record; WoS full record; WoS citing articles
  Impact Factor 3.379 Times cited 17 Open Access
  Notes ; This research was supported by the Interuniversity Attraction Poles Programme-Belgian Science Policy (IUAP VI/16). The text also presents results of GOA “XANES meets ELNES” (Research Fund University of Antwerp, Belgium) and from FWO (Brussels, Belgium) projects no. G.0704.08 and G.01769.09. Special thanks to Ms Leonie Seliger, head of the stained-glass conservation studio (The Cathedral Studios-The Chapter of Canterbury Cathedral) for the supply of the archaeological samples. The authors gratefully acknowledge ESRF for granting beamtime (proposal EC-602). ; Approved Most recent IF: 3.379; 2011 IF: 3.220
  Call Number UA @ admin @ c:irua:93848 Serial 5613
Permanent link to this record
 

 
Author Monico, L.; Janssens, K.; Alfeld, M.; Cotte, M.; Vanmeert, F.; Ryan, C.G.; Falkenberg, G.; Howard, D.L.; Brunetti, B.G.; Miliani, C.
  Title Full spectral XANES imaging using the Maia detector array as a new tool for the study of the alteration process of chrome yellow pigments in paintings by Vincent van Gogh Type A1 Journal article
  Year 2015 Publication Journal of analytical atomic spectrometry Abbreviated Journal J Anal Atom Spectrom
  Volume 30 Issue 3 Pages 613-626
  Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
  Abstract A combination of synchrotron radiation (SR) micro X-ray fluorescence (m-XRF) and XRF mode X-ray absorption near edge structure (XANES) measurements at the Cr K-edge already allowed us to establish that the photo-reduction of chromates to Cr(III) compounds is the cause of darkening of chrome yellow pigments (PbCr1-xSxO4, 0 <= x <= 0.8) in a number of paintings by Vincent van Gogh and in corresponding artificially aged paint models. A silicon drift detector (SDD) was employed to record the Cr-K XRF radiation in these X-ray micro beam-based measurements. However, in view of the limited count rate capabilities and collection solid angle of a single device, m-XRF and m-XANES employing single element SDDs (or similar) are primarily suited for collection of spectral data from individual points. Additionally, collection of XRF maps via point-by-point scanning with relatively long dwell times per point is possible but is usually confined to small areas. The development of the 384 silicon-diode array Maia XRF detector has provided valuable solutions in terms of data acquisition rate, allowing for full spectral (FS) XANES imaging in XRF mode, i.e., where spectroscopic information is available at each pixel in the scanned map. In this paper, the possibilities of SR Cr K-edge FS-XANES imaging in XRF mode using the Maia detector are examined as a new data collection strategy to study the speciation and distribution of alteration products of lead chromate-based pigments in painting materials. The results collected from two micro-samples taken from two Van Gogh paintings and an aged paint model show the possibility to perform FS-XANES imaging in practical time frames (from several minutes to a few hours) by scanning regions of sample sizes of the same order (more than 500 mm). The sensitivity and capabilities of FS-XANES imaging in providing representative chemical speciation information at the microscale (spatial resolution from similar to 2 to 0.6 mm) over the entire scanned area are demonstrated by the identification of Cr(OH) 3, Cr(III) sulfates and/or Cr(III) organometallic compounds in the corresponding phase maps, as alteration products. Comparable Cr-speciation results were obtained by performing equivalent higher spatial resolution SR m-XRF/single-point m-XANES analysis using a more conventional SDD from smaller regions of interest of each sample. Thus, large-area XRF mode FS-XANES imaging (Maia detector) is here proposed as a valuable and complementary data collection strategy in relation to “ zoomed-in” high-resolution m-XRF mapping and single-point m-XANES analysis (SDD).
  Address
  Corporate Author Thesis
  Publisher Place of Publication Editor
  Language Wos 000350650800006 Publication Date 2014-12-17
  Series Editor Series Title Abbreviated Series Title
  Series Volume Series Issue Edition
  ISSN (up) 0267-9477 ISBN Additional Links UA library record; WoS full record; WoS citing articles
  Impact Factor 3.379 Times cited 28 Open Access
  Notes ; This research was supported by the Interuniversity Attraction Poles Programme – Belgian Science Policy (S2-ART project S4DA), GOA “SOLARPAINT” (Research Fund University of Antwerp, Belgium) and FWO (Brussels, Belgium) project no. G.0C12.13, G.0704.08 and G.01769.09. Support from the Italian projects PRIN (SICH Sustainability in Cultural Heritage: from diagnosis to the development of innovative system for consolidation, cleaning and protection) and PON (ITACHA Italian advanced technologies for cultural heritage applications) is also acknowledged. For the grants received thanks are expressed to ESRF (experiments EC-799, EC-1051) and DESY (experiment H-20000043). Part of this research was undertaken at the XFM beamline at the Australian Synchrotron, Victoria, Australia (experiment M4604). LM acknowledges the CNR for the financial support received in the framework of the Short Term Mobility Programme 2013. Thanks are expressed to Ella Hendriks (Van Gogh Museum, Amsterdam), Muriel Geldof (Cultural Heritage Agency of The Netherlands) and Margje Leeuwestein (Kroller-Muller Museum, Otterlo) for selecting and sharing the information on the cross-section taken from the paintings The Bedroom and Falling Leaves (Les Alyscamps). All the staff of the Van Gogh Museum and the Kroller-Muller Museum are acknowledged for their agreeable cooperation. ; Approved Most recent IF: 3.379; 2015 IF: 3.466
  Call Number UA @ admin @ c:irua:125475 Serial 5628
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Author Kempenaers, L.; Janssens, K.; Jochum, K.P.; Vincze, L.; Vekemans, B.; Somogyi, A.; Drakopoulos, M.; Adams, F.
  Title Micro-heterogeneity study of trace elements in USGS, MPI-DING and glass reference materials by means of synchrotron micro-XRF Type A1 Journal article
  Year 2003 Publication Journal of analytical atomic spectrometry Abbreviated Journal J Anal Atom Spectrom
  Volume 18 Issue Pages 350-357
  Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
  Abstract
  Address
  Corporate Author Thesis
  Publisher Place of Publication Editor
  Language Wos 000181827800010 Publication Date 2003-03-27
  Series Editor Series Title Abbreviated Series Title
  Series Volume Series Issue Edition
  ISSN (up) 0267-9477 ISBN Additional Links UA library record; WoS full record; WoS citing articles
  Impact Factor 3.379 Times cited 38 Open Access
  Notes Approved Most recent IF: 3.379; 2003 IF: 3.200
  Call Number UA @ admin @ c:irua:41009 Serial 5715
Permanent link to this record
 

 
Author Alfeld, M.; Janssens, K.; Dik, J.; de Nolf, W.; van der Snickt, G.
  Title Optimization of mobile scanning macro-XRF systems for the in situ investigation of historical paintings Type A1 Journal article
  Year 2011 Publication Journal of analytical atomic spectrometry Abbreviated Journal J Anal Atom Spectrom
  Volume 26 Issue 5 Pages 899-909
  Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
  Abstract Elemental distribution maps are of great interest in the study of historical paintings, as they allow to investigate the pigment use of the artist, to image changes made in the painting during or after its creation and in some cases to reveal discarded paintings that were later over painted. Yet a method that allows to record such maps of a broad range of elements in a fast, non-destructive and in situ manner is not yet commonly available; a dedicated mobile scanning XRF instrument might fill this gap. In this paper we present three self-built scanning macro-XRF instruments, each based on the experience gained with its precursor. These instruments are compared in terms of sensitivity and limits of detection, which includes a discussion of the use of polycapillary optics and pinhole collimators as beam defining devices. Furthermore, the imaging capabilities of the instruments are demonstrated in three exemplary cases: (parts of) historical paintings from the 15th to the 19th century are examined. These cases illustrate the value of element specific distribution maps in the study of historical paintings and allow in the case of Vincent van Gogh's Patch of Grass a direct comparison between in situ and synchrotron based scanning macro-XRF.
  Address
  Corporate Author Thesis
  Publisher Place of Publication Editor
  Language Wos 000289731900004 Publication Date 2011-03-21
  Series Editor Series Title Abbreviated Series Title
  Series Volume Series Issue Edition
  ISSN (up) 0267-9477 ISBN Additional Links UA library record; WoS full record; WoS citing articles
  Impact Factor 3.379 Times cited 107 Open Access
  Notes ; The investigation of the “Triptych of the Seven Sacraments'' was done in collaboration with Griet Steyaert, independent restorer, and Lizet Klaassen, Royal Museum of Fine Arts (Antwerp, Belgium). The investigation of ”Patch of Grass'' was realized in collaboration with Luuk van der Loeff, Kroller-Muller-Museum (Otterlo, The Netherlands). M. Alfeld is a PhD fellowship of the Research Foundation-Flanders (FWO). This research was supported by the Interuniversity Attraction Poles Programme-Belgian Science Policy (IUAP VI/16) NACHO. The text also presents results of GOA "XANES meets ELNES'' (Research Fund University of Antwerp, Belgium) and from FWO (Brussels, Belgium) projects no. G.0103.04, G.0689.06 and G.0704.08. Further, the work presented was sponsored by the Innovational Research Incentives Scheme of the Netherlands Organization for Scientific Research, NWO (proj. no. 016.118.303). ; Approved Most recent IF: 3.379; 2011 IF: 3.220
  Call Number UA @ admin @ c:irua:89919 Serial 5758
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Author Alfeld, M.; de Nolf, W.; Cagno, S.; Janssens, K.; et al.
  Title Revealing hidden paint layers in oil paintings by means of scanning macro-XRF : a mock-up study based on Rembrandt's “An old man in military costume” Type A1 Journal article
  Year 2013 Publication Journal of analytical atomic spectrometry Abbreviated Journal J Anal Atom Spectrom
  Volume 28 Issue 1 Pages 40-51
  Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
  Abstract Over the past several decades the oeuvre of Rembrandt has been the subject of extensive art historical and scientific investigations. One of the most striking features to emerge is his frequent re-use of canvases and panels. The painting An Old Man in Military Costume (78.PB.246), in the collection of the J. Paul Getty Museum, is an example of such a re-used panel. Conventional imaging techniques revealed the presence of a second portrait under the surface portrait, but the details of this hidden portrait have not yet been revealed. Vermilion (HgS) has been identified to have been used nearly exclusively in the flesh tones of the lower painting, suggesting that element-specific XRF imaging might successfully image the hidden portrait. To test this hypothesis, a full-scale mock-up of the painting was created, including a “free impression” of the hidden portrait, reproducing as closely as possible the pigments and paint stratigraphy of the original painting. XRF imaging of the mock-up painting was conducted using three different XRF imaging systems: a mobile X-ray tube based system and two synchrotron-based setups (one equipped with multiple SDDs and one equipped with a Maia detector). The sensitivity, limits of detection and imaging capabilities of each system under the chosen experimental conditions are evaluated and compared. The results indicate that an investigation of the original painting by this method would have an excellent chance of success.
  Address
  Corporate Author Thesis
  Publisher Place of Publication Editor
  Language Wos 000314903400003 Publication Date 2012-11-22
  Series Editor Series Title Abbreviated Series Title
  Series Volume Series Issue Edition
  ISSN (up) 0267-9477 ISBN Additional Links UA library record; WoS full record; WoS citing articles
  Impact Factor 3.379 Times cited Open Access
  Notes ; This research was supported by the Interuniversity Attraction Poles Programme – Belgian Science Policy (IUAP VI/16). The text also presents results of GOA “XANES meets ELNES” (Research Fund University of Antwerp, Belgium) and from FWO (Brussels, Belgium) projects no. G.0704.08 and G.01769.09. Further, 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. M. Alfeld receives a Ph.D. fellowship of the Research Foundation – Flanders (FWO). The authors gratefully acknowledge Yvonne Szafran and the staff of the Paintings Conservation Department of the J. Paul Getty Museum for making available their infrared reflectography (IRR) and X-radiographic images of the painting, and also the neutron activation analysis (NAA) images acquired in 1996 at NIST by Dr Henry Prask in collaboration with Mark Leonard, former head of the J. Paul Getty Museum Paintings Conservation Department. We are also grateful to Peter Reischig, a graduate intern at the Getty Conservation Institute and a Ph.D. candidate at Delft University of Technology for his assistance. ; Approved Most recent IF: 3.379; 2013 IF: 3.396
  Call Number UA @ admin @ c:irua:107704 Serial 5818
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