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	Author	Bia, P.; Caratelli, D.; Mescia, L.; Gielis, J.
	Title	Analysis and synthesis of supershaped dielectric lens antennas			Type	A1 Journal article
	Year	2015	Publication	IET microwaves, antennas and propagation	Abbreviated Journal
	Volume	9	Issue	14	Pages	1497-1504
	Keywords	A1 Journal article; Engineering sciences. Technology; Mass communications; Sustainable Energy, Air and Water Technology (DuEL)
	Abstract	A novel class of supershaped dielectric lens antennas, whose geometry is described by the three-dimensional (3D) Gielis formula, is introduced and analysed. To this end, a hybrid modelling approach based on geometrical and physical optics is adopted in order to efficiently analyse the multiple wave reflections occurring within the lens and to evaluate the relevant impact on the radiation properties of the antenna under analysis. The developed modelling procedure has been validated by comparison with numerical results already reported in the literature and, afterwards, applied to the electromagnetic characterisation of Gielis dielectric lens antennas with shaped radiation pattern. Furthermore, a dedicated optimisation algorithm based on quantum particle swarm optimisation has been developed for the synthesis of 3D supershaped lens antennas with single feed, as well as with beamforming capabilities.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Wos	000364491200002	Publication Date	2015-08-14
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	1751-8725	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor		Times cited		Open Access
	Notes				Approved	no
	Call Number	UA @ admin @ c:irua:128659			Serial	7441
Permanent link to this record



	Author	Retuerto, M.; Yin, Z.; Emge, T.J.; Stephens, P.W.; Li, M.R.; Sarkar, T.; Croft, M.C.; Ignatov, A.; Yuan, Z.; Zhang, S.J.; Jin, C.; Paria Sena, R.; Hadermann, J.; Kotliar, G.; Greenblatt, M.;
	Title	Hole doping and structural transformation in CsTl_1-xHg_xCl₃			Type	A1 Journal article
	Year	2015	Publication	Inorganic chemistry	Abbreviated Journal	Inorg Chem
	Volume	54	Issue	54	Pages	1066-1075
	Keywords	A1 Journal article; Electron microscopy for materials research (EMAT)
	Abstract	CsTlCl3 and CsTlF3 perovskites have been theoretically predicted to be superconductors when properly hole-doped. Both compounds have been previously prepared as pure compounds: CsTlCl3 in a tetragonal (I4/m) and a cubic (Fm3̅m) perovskite polymorph and CsTlF3 as a cubic perovskite (Fm3̅m). In this work, substitution of Tl in CsTlCl3 with Hg is reported, in an attempt to hole-dope the system and induce superconductivity. The whole series CsTl1xHgxCl3 (x = 0.0, 0.1, 0.2, 0.4, 0.6, and 0.8) was prepared. CsTl0.9Hg0.1Cl3 is tetragonal as the more stable phase of CsTlCl3. However, CsTl0.8Hg0.2Cl3 is already cubic with the space group Fm3̅m and with two different positions for Tl+ and Tl3+. For x = 0.4 and 0.5, solid solutions could not be formed. For x ≥ 0.6, the samples are primitive cubic perovskites with one crystallographic position for Tl+, Tl3+, and Hg2+. All of the samples formed are insulating, and there is no signature of superconductivity. X-ray absorption spectroscopy indicates that all of the samples have a mixed-valence state of Tl+ and Tl3+. Raman spectroscopy shows the presence of the active TlClTl stretching mode over the whole series and the intensity of the TlClHg mode increases with increasing Hg content. First-principle calculations confirmed that the phases are insulators in their ground state and that Hg is not a good dopant in the search for superconductivity in this system.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication	Easton, Pa	Editor
	Language		Wos	000348887400048	Publication Date	2014-12-09
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	0020-1669;1520-510X;	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	4.857	Times cited	5	Open Access
	Notes				Approved	Most recent IF: 4.857; 2015 IF: 4.762
	Call Number	c:irua:124420			Serial	1476
Permanent link to this record



	Author	Pinera, I.; Cruz, C.M.; Abreu, Y.; Leyva, A.; van Espen, P.; Diaz, A.; Cabal, A.E.; Van Remortel, N.
	Title	Gamma induced atom displacements in LYSO and LuYAP crystals as used in medical imaging applications			Type	A1 Journal article
	Year	2015	Publication	Interactions With Materials And Atoms	Abbreviated Journal
	Volume	356	Issue		Pages	46-52
	Keywords	A1 Journal article; Engineering sciences. Technology; Particle Physics Group; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
	Abstract	The radiation damage, in terms of atom displacements, induced by gamma irradiation in LYSO and LuYAP crystals is presented. Sc-44, Na-22 and V-48 are used as gamma sources for this study. The energy of gammas from the electron positron annihilation processes (511 keV) is also included in the study. The atom displacements distributions inside each material are calculated following the Monte Carlo assisted Classical Method introduced by the authors. This procedure also allows to study the atom displacements in-depth distributions inside each crystal. The atom displacements damage in LYSO crystals is found to be higher than in LuYAP crystals, mainly provoked by the displacements of silicon and oxygen atoms. But the difference between atom displacements produced in LYSO and LuYAP decreases when more energetic sources are used. On the other hand, the correlation between the atom displacements and energy deposition in-depth distributions is excellent. The atom displacements to energy deposition ratio is found to increases with more energetic photon sources. LYSO crystals are then more liable to the atom displacements damage than LuYAP crystals. (C) 2015 Elsevier B.V. All rights reserved.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Wos	000356990400008	Publication Date	2015-05-14
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	0168-583x	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor		Times cited		Open Access
	Notes				Approved	no
	Call Number	UA @ admin @ c:irua:127012			Serial	7987
Permanent link to this record



	Author	Moors, K.; Sorée, B.; Magnus, W.
	Title	Modeling and tackling resistivity scaling in metal nanowires			Type	P1 Proceeding
	Year	2015	Publication	International Conference on Simulation of Semiconductor Processes and Devices : [proceedings] T2 – International Conference on Simulation of Semiconductor Processes and, Devices (SISPAD), SEP 09-11, 2015, Washington, DC	Abbreviated Journal
	Volume		Issue		Pages	222-225
	Keywords	P1 Proceeding; Condensed Matter Theory (CMT)
	Abstract	A self-consistent analytical solution of the multi-subband Boltzmann transport equation with collision term describing grain boundary and surface roughness scattering is presented to study the resistivity scaling in metal nanowires. The different scattering mechanisms and the influence of their statistical parameters are analyzed. Instead of a simple power law relating the height or width of a nanowire to its resistivity, the picture appears to be more complicated due to quantum-mechanical scattering and quantization effects, especially for surface roughness scattering.
	Address
	Corporate Author				Thesis
	Publisher	Ieee	Place of Publication	New york	Editor
	Language		Wos		Publication Date
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	978-1-4673-7860-4	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:135046			Serial	4205
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	Author	De Schepper, E.; Van Passel, S.; Lizin, S.
	Title	Economic benefits of combining clean energy technologies : the case of solar photovoltaics and battery electric vehicles			Type	A1 Journal article
	Year	2015	Publication	International Journal Of Energy Research	Abbreviated Journal	Int J Energ Res
	Volume	39	Issue	8	Pages	1109-1119
	Keywords	A1 Journal article; Economics; Engineering sciences. Technology; Engineering Management (ENM)
	Abstract	The combined use of clean technologies can lead amongst other benefits to reduced environmental impacts, improved system efficiencies, better management of land scarcity, and diminishment of the effect of power variability of intermittent clean energy sources. Nonetheless, private investors facing budgetary constraints will only opt to invest in the combination of technologies if the latter is more profitable than the investment in a single technology. The aim of the paper is to provide a systematic model for decision makers that allows them to evaluate the profitability of any random combination of technologies under budgetary constraints, and to compare this profitability with that of the individual projects in isolation. This research goes beyond the state of art in the field of financial management and more specifically in the field of the rationing of capital amongst interdependent projects, by developing a method to calculate the payoff of interdependent projects undertaken together. Moreover, this paper develops a computational model from the investor's point of view, of which the purpose is threefold: First, the model allows to directly compare the economic payoff of individual complementary technologies with the economic payoff of their integrated combination, under budgetary constraints. Second, the model calculates economic synergies labeled benefits of combined technologies' (BOCT) when combining complementary technologies. Third, the model explains the rationalization behind the presence of BOCT. The model exemplifies an ex ante cost benefit analysis developed for business and non-governmental use. A four step methodology is proposed and illustrated by means of a case study of PV solar power and battery electric vehicles (BEVs) for a small Belgian enterprise. Results show that at low electricity prices (<Euro0.112/kWh) it is most profitable to invest in BEVs. When the price of electricity rises (>Euro0.134/kWh), investment in exclusively PV becomes most attractive. In all other cases, it is more profitable to invest in the combination of both technologies. Copyright (c) 2015 John Wiley & Sons, Ltd.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Wos	000355732200006	Publication Date	2015-03-21
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	0363-907x	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	2.598	Times cited	14	Open Access
	Notes	; Sebastien Lizin would like to thank the Research Foundation Flanders (FWO), grant number 12G5415N, for their funding without which it would have been impossible to review this work. ;			Approved	Most recent IF: 2.598; 2015 IF: 2.418
	Call Number	UA @ admin @ c:irua:127535			Serial	6188
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	Author	Delmelle, R.; Amin-Ahmadi, B.; Sinnaeve, M.; Idrissi, H.; Pardoen, T.; Schryvers, D.; Proost, J.
	Title	Effect of structural defects on the hydriding kinetics of nanocrystalline Pd thin films			Type	A1 Journal article
	Year	2015	Publication	International journal of hydrogen energy	Abbreviated Journal	Int J Hydrogen Energ
	Volume	40	Issue	40	Pages	7335-7347
	Keywords	A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
	Abstract	While the microstructure of a metal is well-known to affect its equilibrium hydrogen uptake and therefore the hydriding thermodynamics, microstructural effects on the hydriding kinetics are much less documented. Moreover, for thin film systems, such microstructural effects are difficult to separate from the internal stress effect, since most defects generate internal stresses. Such a decoupling has been achieved in this paper for nanocrystalline Pd thin film model systems through the use of a high-resolution, in-situ curvature measurement set-up during Pd deposition, annealing and hydriding. This set-up allowed producing Pd thin films with similar internal stress levels but significantly different microstructures. This was evidenced from detailed defect statistics obtained by transmission electron microscopy, which showed that the densities of grain boundaries, dislocations and twin boundaries have all been lowered by annealing. The same set-up was then used to study the hydriding equilibrium and kinetic behaviour of the resulting films at room temperature. A full quantitative analysis of their hydriding cycles showed that the rate constants of both the adsorption- and absorption-limited kinetic regimes were strongly affected by microstructure. Defect engineering was thereby shown to increase the rate constants for hydrogen adsorption and absorption in Pd by a factor 40 and 30, respectively. Copyright (C) 2015, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication	Oxford	Editor
	Language		Wos	000355884300012	Publication Date	2015-05-02
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	0360-3199;	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	3.582	Times cited	13	Open Access
	Notes	Iap 7/21			Approved	Most recent IF: 3.582; 2015 IF: 3.313
	Call Number	c:irua:126429			Serial	838
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	Author	Pinheiro, C.B.; Abakumov, A.M.
	Title	Superspace crystallography : a key to the chemistry and properties			Type	A1 Journal article
	Year	2015	Publication	IUCrJ	Abbreviated Journal	Iucrj
	Volume	2	Issue	2	Pages	137-154
	Keywords	A1 Journal article; Electron microscopy for materials research (EMAT)
	Abstract	An overview is given of the recent advances in the field of modulated molecular and inorganic crystals with an emphasis on the links between incommensurability, intermolecular and interatomic interactions and, wherever possible, the properties of the materials. The importance of detailed knowledge on the modulated structure for understanding the crystal chemistry and the functional properties of modulated phases is shown using selected examples of incommensurate modulations in organic molecular compounds and inorganic complex oxides.
	Address
	Corporate Author				Thesis
	Publisher	Int union crystallography	Place of Publication	Chester	Editor
	Language		Wos	000356865900016	Publication Date	2014-12-17
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	2052-2525;	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	5.793	Times cited	15	Open Access
	Notes				Approved	Most recent IF: 5.793; 2015 IF: NA
	Call Number	c:irua:127058			Serial	3382
Permanent link to this record



	Author	Barreca, D.; Carraro, G.; Gasparotto, A.; Maccato, C.; Warwick, M.E.A.; Turner, S.; Van Tendeloo, G.
	Title	Fabrication and Characterization of Fe₂O₃-Based Nanostructures Functionalized with Metal Particles and Oxide Overlayers			Type	A1 Journal article
	Year	2015	Publication	Journal of advanced microscopy research	Abbreviated Journal
	Volume	10	Issue	10	Pages	239-243
	Keywords	A1 Journal article; Electron microscopy for materials research (EMAT)
	Abstract	We report on the design of nanosystems based on functionalized -Fe 2 O 3 nanostructures supported on fluorine-doped tin oxide (FTO) substrates. The target materials were developed by means of hybrid vapor phase approaches, combining plasma assisted-chemical vapor deposition (PA-CVD) for the production of iron(III) oxide systems and the subsequent radio frequency (RF)-sputtering or atomic layer deposition (ALD) for the functionalization with Au nanoparticles or TiO 2 overlayers, respectively. The interplay between material characteristics and the adopted processing parameters was investigated by complementary analytical techniques, encompassing X-ray photoelectron spectroscopy (XPS), field emission-scanning electron microscopy (FE-SEM), high angle annular dark field-scanning transmission electron microscopy (HAADF-STEM), and energy dispersive X-ray spectroscopy (EDXS). The obtained results highlight the possibility of fabricating Au/ -Fe 2 O 3 nanocomposites, with a controlled dispersion and distribution of metal particles, and TiO 2 / -Fe 2 O 3 heterostructures, characterized by an intimate coupling between the constituent oxides.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Wos		Publication Date	2015-12-01
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	2156-7573	ISBN		Additional Links	UA library record
	Impact Factor		Times cited		Open Access
	Notes	The authors acknowledge the financial support under the FP7 project “SOLARO- GENIX” (NMP4-SL-2012-310333), as well as Padova University ex-60% 2012–2015 projects, grant n CPDR132937/13 (SOLLEONE), and Regione Lombardia- INSTM ATLANTE program. Stuart Turner acknowledges the FWO Flanders for a post-doctoral scholarship. Thanks are also due to Dr. L. Borgese and Prof. E. Bontempi (Chemistry for Technologies Laboratory, Brescia Univer- sity, Italy) for precious assistance in ALD experiments.			Approved	Most recent IF: NA
	Call Number	EMAT @ emat @ c:irua:132798			Serial	4058
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	Author	Akamine, H.; Van den Bos, K.H.W.; Gauquelin, N.; Farjami, S.; Van Aert, S.; Schryvers, D.; Nishida, M.
	Title	Determination of the atomic width of an APB in ordered CoPt using quantified HAADF-STEM			Type	A1 Journal article
	Year	2015	Publication	Journal of alloys and compounds	Abbreviated Journal	J Alloy Compd
	Volume	644	Issue	644	Pages	570-574
	Keywords	A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
	Abstract	Anti-phase boundaries (APBs) in an ordered CoPt alloy are planar defects which disturb the ordered structure in their vicinity and decrease the magnetic properties. However, it has not yet been clarified to what extend the APBs disturb the ordering. In this study, high-resolution HAADF-STEM images are statistically analysed based on the image intensities estimated by the statistical parameter estimation theory. In the procedure, averaging intensities, fitting the intensity profiles to specific functions, and assessment based on a statistical test are performed. As a result, the APBs in the stable CoPt are found to be characterised by two atomic planes, and a contrast transition range as well as the centre of an inclined APB is determined. These results show that the APBs are quite sharp and therefore may have no notable effect on the net magnetic properties due to their small volume fraction. (C) 2015 Elsevier B.V. All rights reserved.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication	Amsterdam	Editor
	Language		Wos	000357143900083	Publication Date	2015-05-07
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	0925-8388;	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	3.133	Times cited	12	Open Access
	Notes	FWO G036815N; G036915N; G037413N; 278510 VORTEX; Hercules; ECASJO_;			Approved	Most recent IF: 3.133; 2015 IF: 2.999
	Call Number	c:irua:127008 c:irua:127008			Serial	675
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	Author	Deyneko, D.V.; Morozov, V.A.; Hadermann, J.; Savon, A.E.; Spassky, D.A.; Stefanovich, S.Y.; Belik, A.A.; Lazoryak, B.I.
	Title	A novel red Ca_8.5Pb_0.5Eu(PO₄)₇ phosphor for light emitting diodes application			Type	A1 Journal article
	Year	2015	Publication	Journal of alloys and compounds	Abbreviated Journal	J Alloy Compd
	Volume	647	Issue	647	Pages	965-972
	Keywords	A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
	Abstract	Ca9-xPbxEu(PO4)(7) (0 <= x <= 1) solid solutions with a whitlockite-type (or beta-Ca-3(PO4)(2)-type) structure (sp.gr. R3c) were prepared by a standard solid-state method in air. Their luminescent properties under near-ultraviolet (n-UV) light were investigated. Excitation spectra of Ca9-xPbxEu(PO4)(7) showed the strongest absorption at about 395 nm, which matches well with commercially available n-UV-emitting GaN-based LED chips. Emission spectra indicated an intense red emission due to the D-5(0) -> F-7(2) transition of Eu3+, with a maximum in the intensity for Ca8.5Pb0.5Eu(PO4)(7). The emission intensity of Ca8.5Pb0.5Eu(PO4)(7) was about 1.8 times higher than that of a Ca9Eu(PO4)(7) phosphor. We suggest that the introduction of Pb2+ is an efficient approach to enhance luminescence properties of such phosphors. We clarified the influence of the Ca2+/Pb2+ substitution on intensities of three bands for the D-5(0) -> F-7(0) transition in excitation spectra of Ca9-xPbxEu(PO4)(7). In addition, we found a reversible first-order phase transition from R3c to R (3) over barc symmetry by second-harmonic generation in the range from 753 K (x = 1) to 846 K (x = 0). (C) 2015 Elsevier B.V. All rights reserved.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication	Amsterdam	Editor
	Language		Wos	000361156400135	Publication Date	2015-06-18
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	0925-8388	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	3.133	Times cited	18	Open Access
	Notes				Approved	Most recent IF: 3.133; 2015 IF: 2.999
	Call Number	UA @ lucian @ c:irua:128720			Serial	4215
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	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	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
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	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	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	Ceglia, A.; Nuyts, G.; Meulebroeck, W.; Cagno, S.; Silvestri, A.; Zoleo, A.; Nys, K.; Janssens, K.; Thienpont, H.; Terryn, H.
	Title	Iron speciation in soda-lime-silica glass: a comparison of XANES and UV-vis-NIR spectroscopy			Type	A1 Journal article
	Year	2015	Publication	Journal of analytical atomic spectrometry	Abbreviated Journal	J Anal Atom Spectrom
	Volume	30	Issue	7	Pages	1552-1561
	Keywords	A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
	Abstract	Scientific analyses of ancient glasses have been carried out for many years using elemental chemical analysis. However, it is known that the control of the redox conditions in the glass melt has a strong implication on the final hue of glass because it affects Fe2+/SFe. Therefore an increasing number of studies on the redox conditions have been published in recent years by means of synchrotron based Xray absorption spectroscopy. This is a technique which is not easily accessible and requires dedicated facilities. In this paper we describe an alternative approach by means of optical absorption spectroscopy. We synthesised 10 soda-lime-silica glasses with known redox conditions and iron concentration to calibrate the absorption at 1100 nm as a function of Fe2+ concentration. The linear extinction coefficient was also determined. These glasses were also studied by means of X-ray Absorption Near Edge Structure (XANES) spectroscopy. Electron paramagnetic resonance spectroscopy was additionally used as an ancillary method to verify the quality of our data. Furthermore 28 samples from real archaeological samples were analysed by XANES and optical spectroscopy as a case study. The Fe2+/SFe values obtained were compared and demonstrated that the two techniques were in good agreement with each other. Optical spectroscopy can be applied in situ with moderate sample preparation to determine the concentration of Fe2+. To investigate the redox conditions, especially as a first screening approach, this methodology is an important tool to take into consideration before applying more sophisticated techniques such as XANES, which is more elaborate and requires high-tech resources.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Wos	000356971900009	Publication Date	2015-04-15
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	0267-9477	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	3.379	Times cited	20	Open Access
	Notes	; The research leading to these results has received funding from the European Union Seventh Framework Programme FP7/2007-2013 under grant agreement no. 265010. For more information please visit the NARNIA website: http:// narnia-itn.eu/. This work was partly supported by the Research Council of Norway through its Centres of Excellence funding scheme, project number 223268/ F50. We are grateful to the ESRF for granting beamtime and Dipanjan Banerjee for his help at the beamline. We are thankful to the R&D department of AGC Glass Europe, in particular Dr Benoit Cherdon, Dr Dominique Michiels and Ms Dominique Delleuze, for preparing glass for us and providing us the chemical information. A special thanks to M. Fialin for the help with EPMA measurements in CAMPARIS. We want to express our gratitude to F. Farges and A. Berry for sharing their XANES spectra with us. Thanks to Anne Isabelle for reading this paper and giving comments. Finally we are grateful to two anonymous reviewers who contributed to improve this paper. ;			Approved	Most recent IF: 3.379; 2015 IF: 3.466
	Call Number	UA @ admin @ c:irua:127060			Serial	5679
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	Author	Nuyts, G.; Cagno, S.; Bugani, S.; Janssens, K.
	Title	Micro-XANES study on Mn browning: use of quantitative valence state maps			Type	A1 Journal article
	Year	2015	Publication	Journal of analytical atomic spectrometry	Abbreviated Journal	J Anal Atom Spectrom
	Volume	30	Issue	3	Pages	642-650
	Keywords	A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
	Abstract	Historical glass, especially non-durable medieval glass, can undergo corrosion. This sometimes results in the formation of dark-coloured manganese-rich inclusions that reduce the transparency of the glass. While unaltered bulk glass contains manganese mainly present in the +II valence state, inside the inclusions Mn is present in higher valence states (+III to +IV). Two different strategies may be considered by conservators when aiming to improve the transparency. One is based on the reduction of highly oxidised black/brown compounds using mildly reducing solutions, while the other focuses more on the extraction of manganese from the inclusions by the application of chelating agents. In this paper, a method for quantitative mapping of the Mn speciation inside partially corroded historical windowpanes based on X-Ray Absorption Near-Edge Structure (XANES) spectroscopy is discussed. The calibration of such Mn valence state maps based on the combo method, a fairly reliable way to determine the oxidation state, is described in more detail. This method is used to evaluate the effect of reducing treatments on historical glass, dated to the 14th century and originating from Sidney Sussex College (Cambridge, UK), suffering from Mn browning. Glasses were examined by means of Synchrotron Radiation (SR) based microscopic X-Ray Absorption Near-Edge Structure (mXANES) spectroscopy and microscopic X-Ray Fluorescence (mXRF). X-Ray elemental distribution maps of glass cross-sections are recorded at different energies, while Mn K-edge spectra are used to convert these into Mn valence state (VS) maps. Such valence state maps will allow evaluation of a reducing treatment.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Wos	000350650800009	Publication Date	2015-02-23
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	0267-9477	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	3.379	Times cited	8	Open Access
	Notes	; This research was supported by the Interuniversity Attraction Poles Programme Belgian Science Policy (IUAP VI/16) and partially by the Research Council of Norway through its Centres of Excellence funding scheme, project number 223268/ F50. The text also presents results of Center of Excellence AGRECHEM (Research Fund University of Antwerp, Belgium) and from the Fund for Scientific Research (FWO, Brussels, Belgium) projects no. G.0C12.13 and G.01769.09. We gratefully acknowledge ESRF for granting beamtime (experiment EC768) and the beamline scientists of ID21 for their support. The authors also want to thank Leonie Seliger of Canterbury Cathedral, UK, the Sidney Sussex College Council and Bursar Charles Larkum for providing the archaeological samples of the Franciscan Friary which are kept in store for Sidney Sussex College in Cambridge (UK). ;			Approved	Most recent IF: 3.379; 2015 IF: 3.466
	Call Number	UA @ admin @ c:irua:125476			Serial	5719
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	Author	Alfeld, M.; Janssens, K.
	Title	Strategies for processing mega-pixel X-ray fluorescence hyperspectral data: a case study on a version of Caravaggio's painting Supper at Emmaus			Type	A1 Journal article
	Year	2015	Publication	Journal of analytical atomic spectrometry	Abbreviated Journal	J Anal Atom Spectrom
	Volume	30	Issue	3	Pages	777-789
	Keywords	A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
	Abstract	Technical progress in the fields of X-ray sources, optics and detectors is constantly enhancing the pace of data acquisition in XRF imaging. This enlarges the size of the hyperspectral datasets and the number of their sub-parts. This paper describes the challenges in processing large XRF datasets featuring several million pixels/spectra and the strategies developed to overcome them. During the investigation of historical paintings by scanning macro-XRF the main challenges are the correct identification of all spectral features in a dataset and its timely processing. For the identification of spectral features different approaches are discussed, i.e. the use of sum spectra, maximum pixel spectra and of chi(2)(r) maps. For the time-efficient, artefact-free evaluation of XRF imaging data, different software packages are evaluated and intercompared (AXIL, PyMCA, GeoPIXE and the in-house written datamuncher). The process of data evaluation is illustrated on a large dataset (3.4 MPixels) acquired during the investigation of a version of Caravaggio's Supper at Emmaus (143 x 199.5 cm(2)). This 17th century painting is currently the largest object entirely scanned with macroscopic XRF.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Wos	000350650800026	Publication Date	2015-02-12
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	0267-9477	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	3.379	Times cited	67	Open Access
	Notes	; The authors would like to thank W. de Nolf, A. Rothkirch, C. Ryan, A. Sole, B. Vekemans, P. van Espen and L. Vincze for their fruitful discussions over the years. Furthermore, the authors thank D. Swetzoff for his support. M. Alfeld was from 2009 to 2013 the recipient of a Ph.D. fellowship of the Research Foundation-Flanders (FWO, Brussels). ;			Approved	Most recent IF: 3.379; 2015 IF: 3.466
	Call Number	UA @ admin @ c:irua:125477			Serial	5848
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	Author	Monico, L.; Janssens, K.; Cotte, M.; Romani, A.; Sorace, L.; Grazia, C.; Brunetti, B.G.; Miliani, C.
	Title	Synchrotron-based X-ray spectromicroscopy and electron paramagnetic resonance spectroscopy to investigate the redox properties of lead chromate pigments under the effect of visible light			Type	A1 Journal article
	Year	2015	Publication	Journal of analytical atomic spectrometry	Abbreviated Journal	J Anal Atom Spectrom
	Volume	30	Issue	7	Pages	1500-1510
	Keywords	A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
	Abstract	Light-induced redox processes have been established as the cause of the chromatic alterations of a number of artists' pigments used from the 15th to the 20th century. Despite the fact that a general comprehension of the mechanisms has been provided through the characterization of photo-degraded compounds, both exhaustive information on the wavelength-dependence of the alteration process of the pigments and experimental evidence in how visible light may influence the formation pathways of specific secondary compounds are still lacking. Establishing an analytical protocol for the study of wavelength-dependence of pigments on photo-redox pathways is relevant for the safe illumination of paintings, especially in view of the possible use of spectrally tunable light sources such as white light emitting diodes (WLEDs). In this work, we propose an integrated approach based on a combination of diffuse reflectance UV-visible, synchrotron radiation (SR)-based micro X-ray fluorescence (m-XRF)/X-ray absorption near edge structure (m-XANES) and electron paramagnetic resonance (EPR) spectroscopies to study the photo-redox process of Cr(VI) -> Cr(III) for lead chromate yellows (PbCr1-xSxO4, 0 <= x <= 0.8) under exposure to different monochromatic light. In view of the thin (3-5 mm) alteration layer that is formed at the paint surface after light exposure, SR-based Cr K-edge mu-XANES/mu-XRF analysis was employed to obtain information on the abundance, nature and distribution of the alteration of Cr(III)-compounds at the micrometricscale level. On the other hand, EPR spectroscopy was used as a complementary tool to the SR-based X-ray methods due to its sensitivity for revealing species containing one or more unpaired electrons and for distinguishing different coordination geometries of paramagnetic centers, such as Cr(V)-species. Semi-quantitative indications about the darkening of the paint surface were obtained by UV-Vis spectroscopy. An abundance of reduced Cr down to around 50% was detected at the aged surface of chrome yellow paints. The reduction process was favored not only by wavelengths shorter than 460 nm (i.e., where the pigment shows its maximum absorption) but also by light in the 490-530 nm range. The first evidence of the presence of Cr(V)-intermediates in the Cr(VI) -> Cr(III) reduction reaction allowed the risks of inducing photo-degradation of the 490-530 nm wavelength range to be explained.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Wos	000356971900004	Publication Date	2015-04-15
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	0267-9477	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	3.379	Times cited	17	Open Access
	Notes	; This research was supported by the Italian projects PRIN-(SICH) and PON- (ITACHA) and by Belgian Science Policy project S2-ART (BELSPO S4DA), the GOA “SOLARPAINT” (Research Fund Antwerp University, Belgium) and FWO (Brussels, Belgium) projects no. G.0C12.13, G.0704.08 and G.01769.09. ESRF is acknowledged for the grants received (experiments HG18 and HG26). L.S. and L.M. acknowledge the financial support of Ente-CRF and CNR-Short Term Mobility Programme 2013, respectively. ;			Approved	Most recent IF: 3.379; 2015 IF: 3.466
	Call Number	UA @ admin @ c:irua:127059			Serial	5862
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	Author	Radepont, M.; Coquinot, Y.; Janssens, K.; Ezrati, J.-J.; de Nolf, W.; Cotte, M.
	Title	Thermodynamic and experimental study of the degradation of the red pigment mercury sulfide			Type	A1 Journal article
	Year	2015	Publication	Journal of analytical atomic spectrometry	Abbreviated Journal	J Anal Atom Spectrom
	Volume	30	Issue	3	Pages	599-612
	Keywords	A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
	Abstract	The red pigment mercury sulfide, called cinnabar or vermilion, is well known to suffer from an alteration giving rise to a grey, grey-white or black color at the surface of degraded works of art. This phenomenon can dramatically affect the esthetical value of artworks. This work aims at assessing the factors (light, halides) influencing the instability of red mercury sulfide and understanding (by combining thermodynamic and experimental approaches) the chemical equilibria governing the formation and evolution of the different degradation compounds. From the thermodynamic study of the Hg-S-Cl-H2O system, it was concluded that Hg(0), Hg3S2Cl2, and Hg2Cl2 can be formed from the reaction of alpha-HgS with ClO(g). In the second part, the artificial ageing experiments presented were carried out on model samples following the conditions assessed in the first part, in order to reproduce natural ageing observed on red mercury sulfide. Similarly to degradation compounds detected on original works of art, mercury chlorine compounds such as calomel (Hg2Cl2) and corderoite (alpha-Hg3S2Cl2) were identified on the surface of alpha-HgS model samples, when exposed to light and a sodium hypochlorite solution. Sulfates were detected as well, and more particularly gypsum (CaSO4 center dot 2H(2)O) when Ca was originally present in the model sample. The relationship between color and composition is discussed as well.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Wos	000350650800005	Publication Date	2015-01-02
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	0267-9477	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	3.379	Times cited	26	Open Access
	Notes	; The authors gratefully acknowledge the ESRF for granting beamtime under proposal no. EC720. Michel Dubus is thanked for providing precious advices concerning ageing protocols. This research was supported by Belgian Science Policy project S2-ART (BELSPO S4DA), the GOA “SOLARPAINT” (Research Fund University of Antwerp, Belgium) and FWO (Brussels, Belgium) projects no. G.0C12.13, G.0704.08 and G.01769.09. ;			Approved	Most recent IF: 3.379; 2015 IF: 3.466
	Call Number	UA @ admin @ c:irua:125474			Serial	5877
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	Author	Sarmadian, N.; Saniz, R.; Partoens, B.; Lamoen, D.
	Title	Ab initio study of shallow acceptors in bixbyite V₂O₃			Type	A1 Journal article
	Year	2015	Publication	Journal of applied physics	Abbreviated Journal	J Appl Phys
	Volume	117	Issue	117	Pages	015703
	Keywords	A1 Journal article; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT)
	Abstract	We present the results of our study on p-type dopability of bixbyite V2O3 using the Heyd, Scuseria, and Ernzerhof hybrid functional (HSE06) within the density functional theory (DFT) formalism. We study vanadium and oxygen vacancies as intrinsic defects and substitutional Mg, Sc, and Y as extrinsic defects. We find that Mg substituting V acts as a shallow acceptor, and that oxygen vacancies are electrically neutral. Hence, we predict Mg-doped V2O3 to be a p-type conductor. Our results also show that vanadium vacancies are relatively shallow, with a binding energy of 0.14 eV, so that they might also lead to p-type conductivity.
	Address
	Corporate Author				Thesis
	Publisher	American Institute of Physics	Place of Publication	New York, N.Y.	Editor
	Language		Wos	000347958600067	Publication Date	2015-01-05
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	0021-8979;1089-7550;	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	2.068	Times cited	3	Open Access
	Notes	FWO G015013; Hercules			Approved	Most recent IF: 2.068; 2015 IF: 2.183
	Call Number	c:irua:122728			Serial	35
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	Author	Zhao, S.-X.; Zhang, Y.-R.; Gao, F.; Wang, Y.-N.; Bogaerts, A.
	Title	Bulk plasma fragmentation in a C₄F₈ inductively coupled plasma : a hybrid modelling study			Type	A1 Journal article
	Year	2015	Publication	Journal of applied physics	Abbreviated Journal	J Appl Phys
	Volume	117	Issue	117	Pages	243303
	Keywords	A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
	Abstract	A hybrid model is used to investigate the fragmentation of C4F8 inductive discharges. Indeed, the resulting reactive species are crucial for the optimization of the Si-based etching process, since they determine the mechanisms of fluorination, polymerization, and sputtering. In this paper, we present the dissociation degree, the density ratio of F vs. CxFy (i.e., fluorocarbon (fc) neutrals), the neutral vs. positive ion density ratio, details on the neutral and ion components, and fractions of various fc neutrals (or ions) in the total fc neutral (or ion) density in a C4F8 inductively coupled plasma source, as well as the effect of pressure and power on these results. To analyze the fragmentation behavior, the electron density and temperature and electron energy probability function (EEPF) are investigated. Moreover, the main electron-impact generation sources for all considered neutrals and ions are determined from the complicated C4F8 reaction set used in the model. The C4F8 plasma fragmentation is explained, taking into account many factors, such as the EEPF characteristics, the dominance of primary and secondary processes, and the thresholds of dissociation and ionization. The simulation results are compared with experiments from literature, and reasonable agreement is obtained. Some discrepancies are observed, which can probably be attributed to the simplified polymer surface kinetics assumed in the model.
	Address
	Corporate Author				Thesis
	Publisher	American Institute of Physics	Place of Publication	New York, N.Y.	Editor
	Language		Wos	000357613900009	Publication Date	2015-06-30
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	0021-8979;1089-7550;	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	2.068	Times cited	11	Open Access
	Notes				Approved	Most recent IF: 2.068; 2015 IF: 2.183
	Call Number	c:irua:126477			Serial	261
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	Author	Berdiyorov, G.; Harrabi, K.; Mehmood, U.; Peeters, F.M.; Tabet, N.; Zhang, J.; Hussein, I.A.; McLachlan, M.A.
	Title	Derivatization and diffusive motion of molecular fullerenes : ab initio and atomistic simulations			Type	A1 Journal article
	Year	2015	Publication	Journal of applied physics	Abbreviated Journal	J Appl Phys
	Volume	118	Issue	118	Pages	025101
	Keywords	A1 Journal article; Condensed Matter Theory (CMT)
	Abstract	Using first principles density functional theory in combination with the nonequilibrium Green's function formalism, we study the effect of derivatization on the electronic and transport properties of C-60 fullerene. As a typical example, we consider [6,6]-phenyl-C-61-butyric acid methyl ester (PCBM), which forms one of the most efficient organic photovoltaic materials in combination with electron donating polymers. Extra peaks are observed in the density of states (DOS) due to the formation of new electronic states localized at/near the attached molecule. Despite such peculiar behavior in the DOS of an isolated molecule, derivatization does not have a pronounced effect on the electronic transport properties of the fullerene molecular junctions. Both C-60 and PCBM show the same response to finite voltage biasing with new features in the transmission spectrum due to voltage induced delocalization of some electronic states. We also study the diffusive motion of molecular fullerenes in ethanol solvent and inside poly(3-hexylthiophene) lamella using reactive molecular dynamics simulations. We found that the mobility of the fullerene reduces considerably due to derivatization; the diffusion coefficient of C-60 is an order of magnitude larger than the one for PCBM. (c) 2015 AIP Publishing LLC.
	Address
	Corporate Author				Thesis
	Publisher	American Institute of Physics	Place of Publication	New York, N.Y.	Editor
	Language		Wos	000357961000036	Publication Date	2015-07-10
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	0021-8979;1089-7550;	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	2.068	Times cited	2	Open Access
	Notes	; K.H., U.M. and I.A.H. would like to thank the National Science, Technology and Innovation Program of KACST for funding this research under Project No. 12-ENE2379-04. They also acknowledge support from KFUPM and Research Institute. ;			Approved	Most recent IF: 2.068; 2015 IF: 2.183
	Call Number	c:irua:127098			Serial	652
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	Author	Zhao, S.-X.; Gao, F.; Wang, Y.-P.; Wang, Y.-N.; Bogaerts, A.
	Title	Effects of feedstock availability on the negative ion behavior in a C₄F₈ inductively coupled plasma			Type	A1 Journal article
	Year	2015	Publication	Journal of applied physics	Abbreviated Journal	J Appl Phys
	Volume	118	Issue	118	Pages	033301
	Keywords	A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
	Abstract	In this paper, the negative ion behavior in a C4F8 inductively coupled plasma (ICP) is investigated using a hybrid model. The model predicts a non-monotonic variation of the total negative ion density with power at low pressure (1030 mTorr), and this trend agrees well with experiments that were carried out in many fluorocarbon (fc) ICP sources, like C2F6, CHF3, and C4F8. This behavior is explained by the availability of feedstock C4F8 gas as a source of the negative ions, as well as by the presence of low energy electrons due to vibrational excitation at low power. The maximum of the negative ion density shifts to low power values upon decreasing pressure, because of the more pronounced depletion of C4F8 molecules, and at high pressure (∼50 mTorr), the anion density continuously increases with power, which is similar to fc CCP sources. Furthermore, the negative ion composition is identified in this paper. Our work demonstrates that for a clear understanding of the negative ion behavior in radio frequency C4F8 plasma sources, one needs to take into account many factors, like the attachment characteristics, the anion composition, the spatial profiles, and the reactor configuration. Finally, a detailed comparison of our simulation results with experiments is conducted.
	Address
	Corporate Author				Thesis
	Publisher	American Institute of Physics	Place of Publication	New York, N.Y.	Editor
	Language		Wos	000358429200004	Publication Date	2015-07-20
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	0021-8979;1089-7550;	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	2.068	Times cited	1	Open Access
	Notes				Approved	Most recent IF: 2.068; 2015 IF: 2.183
	Call Number	c:irua:126735			Serial	861
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	Author	Bekaert, J.; Saniz, R.; Partoens, B.; Lamoen, D.
	Title	First-principles study of carbon impurities in CuInSe₂ and CuGaSe₂, present in non-vacuum synthesis methods			Type	A1 Journal article
	Year	2015	Publication	Journal of applied physics	Abbreviated Journal	J Appl Phys
	Volume	117	Issue	117	Pages	015104
	Keywords	A1 Journal article; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT)
	Abstract	A first-principles study of the structural and electronic properties of carbon impurities in CuInSe2 and CuGaSe2 is presented. Carbon is present in organic molecules in the precursor solutions used in non-vacuum growth methods for CuInSe2 and CuGaSe2 based photovoltaic cells. These growth methods make more efficient use of material, time, and energy than traditional vacuum methods. The formation energies of several carbon impurities are calculated using the hybrid HSE06 functional. C Cu acts as a shallow donor, CIn and interstitial C yield deep donor levels in CuInSe2, while in CuGaSe2 CGa and interstitial C act as deep amphoteric defects. So, these defects reduce the majority carrier (hole) concentration in p-type CuInSe2 and CuGaSe2 by compensating the acceptor levels. The deep defects are likely to act as recombination centers for the photogenerated charge carriers and are thus detrimental for the performance of the photovoltaic cells. On the other hand, the formation energies of the carbon impurities are high, even under C-rich growth conditions. Thus, few C impurities will form in CuInSe2 and CuGaSe2 in thermodynamic equilibrium. However, the deposition of the precursor solution in non-vacuum growth methods presents conditions far from thermodynamic equilibrium. In this case, our calculations show that C impurities formed in non-equilibrium tend to segregate from CuInSe2 and CuGaSe2 by approaching thermodynamic equilibrium, e.g., via thorough annealing.
	Address
	Corporate Author				Thesis
	Publisher	American Institute of Physics	Place of Publication	New York, N.Y.	Editor
	Language		Wos	000347958600055	Publication Date	2015-01-07
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	0021-8979;1089-7550;	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	2.068	Times cited	6	Open Access
	Notes	FWO G015013; Hercules			Approved	Most recent IF: 2.068; 2015 IF: 2.183
	Call Number	c:irua:122064			Serial	1215
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	Author	Milovanović, S.P.; Moldovan, D.; Peeters, F.M.
	Title	Veselago lensing in graphene with a p-n junction: Classical versus quantum effects			Type	A1 Journal article
	Year	2015	Publication	Journal of applied physics	Abbreviated Journal	J Appl Phys
	Volume	118	Issue	118	Pages	154308
	Keywords	A1 Journal article; Condensed Matter Theory (CMT)
	Abstract	The feasibility of Veselago lensing in graphene with a p-n junction is investigated numerically for realistic injection leads. Two different set-ups with two narrow leads are considered with absorbing or reflecting side edges. This allows us to separately determine the influence of scattering on electron focusing for the edges and the p-n interface. Both semiclassical and tight-binding simulations show a distinctive peak in the transmission probability that is attributed to the Veselago lensing effect. We investigate the robustness of this peak on the width of the injector, the position of the p-n interface, and different gate potential profiles. Furthermore, the influence of scattering by both short- and long-range impurities is considered.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Wos	000363535800022	Publication Date	2015-10-20
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	0021-8979;1089-7550;	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	2.068	Times cited	19	Open Access
	Notes	This work was supported by the Flemish Science Foundation (FWO-Vl), the European Science Foundation (ESF) under the EUROCORES Program EuroGRAPHENE within the project CONGRAN, and the Methusalem Foundation of the Flemish government.			Approved	Most recent IF: 2.068; 2015 IF: 2.183
	Call Number	c:irua:129452			Serial	3969
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	Author	Li, L.L.; Xu, W.; Peeters, F.M.
	Title	Optical conductivity of topological insulator thin films			Type	A1 Journal article
	Year	2015	Publication	Journal of applied physics	Abbreviated Journal	J Appl Phys
	Volume	117	Issue	117	Pages	175305
	Keywords	A1 Journal article; Condensed Matter Theory (CMT)
	Abstract	We present a detailed theoretical study on the optoelectronic properties of topological insulator thin film (TITFs). The k . p approach is employed to calculate the energy spectra and wave functions for both the bulk and surface states in the TITF. With these obtained results, the optical conductivities induced by different electronic transitions among the bulk and surface states are evaluated using the energy-balance equation derived from the Boltzmann equation. We find that for Bi2Se3-based TITFs, three characteristic regimes for the optical absorption can be observed. (i) In the low radiation frequency regime (photon energy (h) over bar omega < 200 meV), the free-carrier absorption takes place due to intraband electronic transitions. An optical absorption window can be observed. (ii) In the intermediate radiation frequency regime (200 < (h) over bar omega < 300 meV), the optical absorption is induced mainly by interband electronic transitions from surface states in the valance band to surface states in the conduction band and an universal value sigma(0) = e(2) / (8<(h)over bar>) for the optical conductivity can be obtained. (iii) In the high radiation frequency regime ((h) over bar omega > 300 meV), the optical absorption can be achieved via interband electronic transitions from bulk and surface states in the valance band to bulk and surface states in the conduction band. A strong absorption peak can be observed. These interesting findings indicate that optical measurements can be applied to identify the energy regimes of bulk and surface states in the TITF. (C) 2015 AIP Publishing LLC.
	Address
	Corporate Author				Thesis
	Publisher	American Institute of Physics	Place of Publication	New York, N.Y.	Editor
	Language		Wos	000354984100615	Publication Date	2015-05-06
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	0021-8979;1089-7550;	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	2.068	Times cited	9	Open Access
	Notes	; This work was supported by the National Natural Science Foundation of China (Grant No. 11304316), Ministry of Science and Technology of China (Grant No. 2011YQ130018), Department of Science and Technology of Yunnan Province, and by the Chinese Academy of Sciences. ;			Approved	Most recent IF: 2.068; 2015 IF: 2.183
	Call Number	c:irua:126412			Serial	2473
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	Author	Zhao, C.X.; Xu, W.; Li, L.L.; Zhang, C.; Peeters, F.M.
	Title	Terahertz plasmon-polariton modes in graphene driven by electric field inside a Fabry-Perot cavity			Type	A1 Journal article
	Year	2015	Publication	Journal of applied physics	Abbreviated Journal	J Appl Phys
	Volume	117	Issue	117	Pages	223104
	Keywords	A1 Journal article; Condensed Matter Theory (CMT)
	Abstract	We present a theoretical study on plasmon-polariton modes in graphene placed inside an optical cavity and driven by a source-to-drain electric field. The electron velocity and electron temperature are determined by solving self-consistently the momentum-and energy-balance equations in which electron interactions with impurities, acoustic-, and optic-phonons are included. Based on many-body self-consistent field theory, we develop a tractable approach to study plasmon-polariton in an electron gas system. We find that when graphene is placed inside a Fabry-Perot cavity, two branches of the plasmon-polariton modes can be observed and these modes are very much optic-or plasmon-like. The frequencies of these modes depend markedly on driving electric field especially at higher resonant frequency regime. Moreover, the plasmon-polariton frequency in graphene is in terahertz (THz) bandwidth and can be tuned by changing the cavity length, gate voltage, and driving electric field. This work is pertinent to the application of graphene-based structures as tunable THz plasmonic devices. (C) 2015 AIP Publishing LLC.
	Address
	Corporate Author				Thesis
	Publisher	American Institute of Physics	Place of Publication	New York, N.Y.	Editor
	Language		Wos	000356176100004	Publication Date	2015-06-10
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	0021-8979;1089-7550;	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	2.068	Times cited	13	Open Access
	Notes	; This work was supported by the Ministry of Science and Technology of China (Grant No. 2011YQ130018), Department of Science and Technology of Yunnan Province, and by the Chinese Academy of Sciences. F.M.P. was a specially appointed Professor for foreign expert at the Chinese Academy of Sciences. ;			Approved	Most recent IF: 2.068; 2015 IF: 2.183
	Call Number	c:irua:127076			Serial	3507
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	Author	Berdiyorov, G.R.; Bahlouli, H.; Peeters, F.M.
	Title	Theoretical study of electronic transport properties of a graphene-silicene bilayer			Type	A1 Journal article
	Year	2015	Publication	Journal of applied physics	Abbreviated Journal	J Appl Phys
	Volume	117	Issue	117	Pages	225101
	Keywords	A1 Journal article; Condensed Matter Theory (CMT)
	Abstract	Electronic transport properties of a graphene-silicene bilayer system are studied using density-functional theory in combination with the nonequilibrium Green's function formalism. Depending on the energy of the electrons, the transmission can be larger in this system as compared to the sum of the transmissions of separated graphene and silicene monolayers. This effect is related to the increased electron density of states in the bilayer sample. At some energies, the electronic states become localized in one of the layers, resulting in the suppression of the electron transmission. The effect of an applied voltage on the transmission becomes more pronounced in the layered sample as compared to graphene due to the larger variation of the electrostatic potential profile. Our findings will be useful when creating hybrid nanoscale devices where enhanced transport properties will be desirable. (C) 2015 AIP Publishing LLC.
	Address
	Corporate Author				Thesis
	Publisher	American Institute of Physics	Place of Publication	New York, N.Y.	Editor
	Language		Wos	000356176100040	Publication Date	2015-06-10
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	0021-8979;1089-7550;	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	2.068	Times cited	10	Open Access
	Notes	; H. B. and F. M. P. acknowledge support from King Fahd University of Petroleum and Minerals, Saudi Arabia, under the RG1329-1 and RG1329-2 DSR Projects. ;			Approved	Most recent IF: 2.068; 2015 IF: 2.183
	Call Number	c:irua:127075			Serial	3611
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	Author	Schoeters, B.; Leenaerts, O.; Pourtois, G.; Partoens, B.
	Title	Ab-initio study of the segregation and electronic properties of neutral and charged B and P dopants in Si and Si/SiO2 nanowires			Type	A1 Journal article
	Year	2015	Publication	Journal of applied physics	Abbreviated Journal	J Appl Phys
	Volume	118	Issue	118	Pages	104306
	Keywords	A1 Journal article; Condensed Matter Theory (CMT); Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
	Abstract	We perform first-principles calculations to investigate the preferred positions of B and P dopants, both neutral and in their preferred charge state, in Si and Si/SiO2 core-shell nanowires (NWs). In order to understand the observed trends in the formation energy, we isolate the different effects that determine these formation energies. By making the distinction between the unrelaxed and the relaxed formation energy, we separate the impact of the relaxation from that of the chemical environment. The unrelaxed formation energies are determined by three effects: (i) the effect of strain caused by size mismatch between the dopant and the host atoms, (ii) the local position of the band edges, and (iii) a screening effect. In the case of the SiNW (Si/SiO2 NW), these effects result in an increase of the formation energy away from the center (interface). The effect of relaxation depends on the relative size mismatch between the dopant and host atoms. A large size mismatch causes substantial relaxation that reduces the formation energy considerably, with the relaxation being more pronounced towards the edge of the wires. These effects explain the surface segregation of the B dopants in a SiNW, since the atomic relaxation induces a continuous drop of the formation energy towards the edge. However, for the P dopants, the formation energy starts to rise when moving from the center but drops to a minimum just next to the surface, indicating a different type of behavior. It also explains that the preferential location for B dopants in Si/SiO2 core-shell NWs is inside the oxide shell just next to the interface, whereas the P dopants prefer the positions next to the interface inside the Si core, which is in agreement with recent experiments. These preferred locations have an important impact on the electronic properties of these core-shell NWs. Our simulations indicate the possibility of hole gas formation when B segregates into the oxide shell.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Wos	000361636900031	Publication Date	2015-09-09
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	0021-8979	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	2.068	Times cited	3	Open Access
	Notes	This work was carried out using the Turing HPC infrastructure at the CalcUA core facility of the Universiteit Antwerpen, a division of the Flemish Supercomputer Center VSC, funded by the Hercules Foundation, the Flemish government and the Universiteit Antwerpen.			Approved	Most recent IF: 2.068; 2015 IF: 2.183
	Call Number	c:irua:128729			Serial	4056
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	Author	Verreck, D.; Verhulst, A.S.; Van de Put, M.; Sorée, B.; Magnus, W.; Mocuta, A.; Collaert, N.; Thean, A.; Groeseneken, G.
	Title	Full-zone spectral envelope function formalism for the optimization of line and point tunnel field-effect transistors			Type	A1 Journal article
	Year	2015	Publication	Journal of applied physics	Abbreviated Journal	J Appl Phys
	Volume	118	Issue	118	Pages	134502
	Keywords	A1 Journal article; Condensed Matter Theory (CMT)
	Abstract	Efficient quantum mechanical simulation of tunnel field-effect transistors (TFETs) is indispensable to allow for an optimal configuration identification. We therefore present a full-zone 15-band quantum mechanical solver based on the envelope function formalism and employing a spectral method to reduce computational complexity and handle spurious solutions. We demonstrate the versatility of the solver by simulating a 40 nm wide In0.53Ga0.47As lineTFET and comparing it to p-n-i-n configurations with various pocket and body thicknesses. We find that the lineTFET performance is not degraded compared to semi-classical simulations. Furthermore, we show that a suitably optimized p-n-i-n TFET can obtain similar performance to the lineTFET. (C) 2015 AIP Publishing LLC.
	Address
	Corporate Author				Thesis
	Publisher	American Institute of Physics	Place of Publication	New York, N.Y.	Editor
	Language		Wos	000362668400025	Publication Date	2015-10-01
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	0021-8979; 1089-7550	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	2.068	Times cited	9	Open Access
	Notes	; D. Verreck acknowledges the support of a Ph.D. stipend from the Institute for the Promotion of Innovation through Science and Technology in Flanders (IWT-Vlaanderen). This work was supported by imec's Industrial Affiliation Program. ;			Approved	Most recent IF: 2.068; 2015 IF: 2.183
	Call Number	UA @ lucian @ c:irua:128765			Serial	4183
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	Author	Moors, K.; Sorée, B.; Magnus, W.
	Title	Modeling surface roughness scattering in metallic nanowires			Type	A1 Journal article
	Year	2015	Publication	Journal of applied physics	Abbreviated Journal	J Appl Phys
	Volume	118	Issue	118	Pages	124307
	Keywords	A1 Journal article; Condensed Matter Theory (CMT)
	Abstract	Ando's model provides a rigorous quantum-mechanical framework for electron-surface roughness scattering, based on the detailed roughness structure. We apply this method to metallic nanowires and improve the model introducing surface roughness distribution functions on a finite domain with analytical expressions for the average surface roughness matrix elements. This approach is valid for any roughness size and extends beyond the commonly used Prange-Nee approximation. The resistivity scaling is obtained from the self-consistent relaxation time solution of the Boltzmann transport equation and is compared to Prange-Nee's approach and other known methods. The results show that a substantial drop in resistivity can be obtained for certain diameters by achieving a large momentum gap between Fermi level states with positive and negative momentum in the transport direction. (C) 2015 AIP Publishing LLC.
	Address
	Corporate Author				Thesis
	Publisher	American Institute of Physics	Place of Publication	New York, N.Y.	Editor
	Language		Wos	000362565800032	Publication Date	2015-09-24
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	0021-8979; 1089-7550	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	2.068	Times cited	11	Open Access
	Notes	; ;			Approved	Most recent IF: 2.068; 2015 IF: 2.183
	Call Number	UA @ lucian @ c:irua:129425			Serial	4207
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	Author	Yagmurcukardes, M.; Sahin, H.; Kang, J.; Torun, E.; Peeters, F.M.; Senger, R.T.
	Title	Pentagonal monolayer crystals of carbon, boron nitride, and silver azide			Type	A1 Journal article
	Year	2015	Publication	Journal of applied physics	Abbreviated Journal	J Appl Phys
	Volume	118	Issue	118	Pages	104303
	Keywords	A1 Journal article; Condensed Matter Theory (CMT)
	Abstract	In this study, we present a theoretical investigation of structural, electronic, and mechanical properties of pentagonal monolayers of carbon (p-graphene), boron nitride (p-B2N4 and p-B4N2), and silver azide (p-AgN3) by performing state-of-the-art first principles calculations. Our total energy calculations suggest feasible formation of monolayer crystal structures composed entirely of pentagons. In addition, electronic band dispersion calculations indicate that while p-graphene and p-AgN3 are semiconductors with indirect bandgaps, p-BN structures display metallic behavior. We also investigate the mechanical properties (in-plane stiffness and the Poisson's ratio) of four different pentagonal structures under uniaxial strain. p-graphene is found to have the highest stiffness value and the corresponding Poisson's ratio is found to be negative. Similarly, p-B2N4 and p-B4N2 have negative Poisson's ratio values. On the other hand, the p-AgN3 has a large and positive Poisson's ratio. In dynamical stability tests based on calculated phonon spectra of these pentagonal monolayers, we find that only p-graphene and p-B2N4 are stable, but p-AgN3 and p-B4N2 are vulnerable against vibrational excitations.
	Address
	Corporate Author				Thesis
	Publisher	American Institute of Physics	Place of Publication	New York, N.Y.	Editor
	Language		Wos	000361636900028	Publication Date	2015-09-08
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	0021-8979; 1089-7550	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	2.068	Times cited	79	Open Access
	Notes	; This work was supported by the Flemish Science Foundation (FWO-Vl) and the Methusalem foundation of the Flemish government. Computational resources were provided by TUBITAK ULAKBIM, High Performance and Grid Computing Center (TR-Grid e-Infrastructure). H.S. was supported by a FWO Pegasus Long Marie Curie Fellowship. H.S. and R.T.S. acknowledge the support from TUBITAK through Project No. 114F397. ;			Approved	Most recent IF: 2.068; 2015 IF: 2.183
	Call Number	UA @ lucian @ c:irua:128415			Serial	4223
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