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Author (up) Mmari, A.G.; Potgieter-Vermaak, S.S.; Bencs, L.; McCrindle, R.I.; Van Grieken, R.
Title Elemental and ionic components of atmospheric aerosols and associated gaseous pollutants in and near Dar es Salaam, Tanzania Type A1 Journal article
Year 2013 Publication Atmospheric environment : an international journal Abbreviated Journal
Volume 77 Issue Pages 51-61
Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Abstract Elemental and water-soluble ionic compounds (WSICs) of atmospheric aerosols (total suspended particulate TSP) and some gaseous pollutants (SO2, NO2 and O3) from a coastal, semi-urban and rural site in and near Dar es Salaam, Tanzania were investigated during dry and wet seasons of January 2005November 2007. Na+, Ca2+, SO42−, NO3− and Cl− made up the dominant fraction of WSICs during the dry season with average concentrations ranging from non-detectable (n.d.)5.4, 0.262.6, 0.7414.7, 0.41.5 and 1.13.4 μg m−3, respectively, while in the wet season, from n.d. up to 1.7, 1.2, 4.4, 2.1 and 3.0 μg m−3, respectively. The total air concentrations of the detected elements (Al, Si, S, Cl, K, Ca, Fe and Zn) showed seasonal and site-specific variation in the range of 7.526.6 with an average of 14.5 μg m−3. Most of the air concentrations of pollutants were observed to decrease with increasing distance from the coastal site, which is under urban and industrial pollutant emissions. Sulphur and nitrogen oxidation ratios during the dry season ranged from 0.08 to 0.91 and 0.013 to 0.049, respectively, while they were between 0.090.65 and 0.0020.095, respectively, in the wet season. These values indicate the photochemical oxidation of SO2 and a high extent of NO3−formation in the atmosphere. Neutralization ratios revealed the presence of acidic SO42− and NO3− aerosols. Principal component analysis identified sea spray, local combustion, vehicular traffic, biomass burning and re-suspended road dust as dominant sources of aerosols at the studied coastal and semi-urban sites. However, at the rural site, besides sea spray, crustal sources, soil dust re-suspension and long-range transport are the possible origins of suspended particulates.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000324848500006 Publication Date 2013-05-01
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1352-2310 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:108096 Serial 7882
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Author (up) Moldovan, D.; Masir, M.R.; Peeters, F.M.
Title Electronic states in a graphene flake strained by a Gaussian bump Type A1 Journal article
Year 2013 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B
Volume 88 Issue 3 Pages 035446-35447
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract The effect of strain in graphene is usually modeled by a pseudomagnetic vector potential which is, however, derived in the limit of small strain. In realistic cases deviations are expected in view of graphene's very high strain tolerance, which can be up to 25%. Here we investigate the pseudomagnetic field generated by a Gaussian bump and we show that it exhibits significant differences with numerical tight-binding results. Furthermore, we calculate the electronic states in the strained region for a hexagon shaped flake with armchair edges. We find that the sixfold symmetry of the wave functions inside the Gaussian bump is directly related to the different effects of strain along the fundamental directions of graphene: zigzag and armchair. Low energy electrons are strongly confined in the armchair directions and are localized on the carbon atoms of a single sublattice.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000322587500003 Publication Date 2013-07-30
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1098-0121;1550-235X; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.836 Times cited 50 Open Access
Notes ; This work was supported by the European Science Foundation (ESF) under the EUROCORES Program Euro-GRAPHENE within the project CONGRAN, the Flemish Science Foundation (FWO-Vl), and the Methusalem Funding of the Flemish Government. ; Approved Most recent IF: 3.836; 2013 IF: 3.664
Call Number UA @ lucian @ c:irua:109800 Serial 1007
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Author (up) Molina, L.; Egoavil, R.; Turner, S.; Thersleff, T.; Verbeeck, J.; Holzapfel, B.; Eibl, O.; Van Tendeloo, G.
Title Interlayer structure in YBCO-coated conductors prepared by chemical solution deposition Type A1 Journal article
Year 2013 Publication Superconductor science and technology Abbreviated Journal Supercond Sci Tech
Volume 26 Issue 7 Pages 075016-75018
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract The functionality of YBa2Cu3O7−δ (YBCO)-coated conductor technology depends on the reliability and microstructural properties of a given tape or wire architecture. Particularly, the interface to the metal tape is of interest since it determines the adhesion, mechanical stability of the film and thermal contact of the film to the substrate. A trifluoroacetate (TFA)metal organic deposition (MOD) prepared YBCO film deposited on a chemical solution-derived buffer layer architecture based on CeO2/La2Zr2O7 and grown on a flexible Ni5 at.%W substrate with a {100}⟨001⟩ biaxial texture was investigated. The YBCO film had a thickness was 440 nm and a jc of 1.02 MA cm−2 was determined at 77 K and zero external field. We present a sub-nanoscale analysis of a fully processed solution-derived YBCO-coated conductor by aberration-corrected scanning transmission electron microscopy (STEM) combined with electron energy-loss spectroscopy (EELS). For the first time, structural and chemical analysis of the valence has been carried out on the sub-nm scale. Intermixing of Ni, La, Ce, O and Ba takes place at these interfaces and gives rise to nanometer-sized interlayers which are a by-product of the sequential annealing process. Two distinct interfacial regions were analyzed in detail: (i) the YBCO/CeO2/La2Zr2O7 region (10 nm interlayer) and (ii) the La2Zr2O7/Ni5 at.%W substrate interface region (20 nm NiO). This is of particular significance for the functionality of these YBCO-coated conductor architectures grown by chemical solution deposition.
Address
Corporate Author Thesis
Publisher Place of Publication Bristol Editor
Language Wos 000319973800024 Publication Date 2013-05-28
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0953-2048;1361-6668; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.878 Times cited 11 Open Access
Notes vortex; Countatoms; Fwo; Esteem2; esteem2jra2; esteem2jra3 ECASJO_; Approved Most recent IF: 2.878; 2013 IF: 2.796
Call Number UA @ lucian @ c:irua:108704UA @ admin @ c:irua:108704 Serial 1698
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Author (up) Monico, L.; Janssens, K.; Miliani, C.; van der Snickt, G.; Brunetti, B.G.; Guidi, M.C.; Radepont, M.; Cotte, M.
Title Degradation process of lead chromate in paintings by Vincent van Gogh studied by means of spectromicroscopic methods : 4 : artificial aging of model samples of co-precipitates of lead chromate and lead sulfate Type A1 Journal article
Year 2013 Publication Analytical chemistry Abbreviated Journal Anal Chem
Volume 85 Issue 2 Pages 860-867
Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Abstract Previous investigations about the darkening of chrome yellow pigments revealed that this form of alteration is attributable to a reduction of the original Cr(VI) to Cr(III), and that the presence of sulfur-containing compounds, most often sulfates, plays a key role during this process. We recently demonstrated that different crystal forms of chrome yellow pigments (PbCrO4 and PbCr1xSxO4) are present in paintings by Vincent van Gogh. In the present work, we show how both the chemical composition and the crystalline structure of lead chromate-based pigments influence their stability. For this purpose, oil model samples made with in-house synthesized powders of PbCrO4 and PbCr1xSxO4 were artificially aged and characterized. We observed a profound darkening only for those paint models made with PbCr1xSxO4, rich in SO42 (x ≥ 0.4), and orthorhombic phases (>30 wt %). Cr and S K-edge micro X-ray absorption near edge structure investigations revealed in an unequivocal manner the formation of up to about 60% of Cr(III)-species in the outer layer of the most altered samples; conversely, independent of the paint models chemical composition, no change in the S-oxidation state was observed. Analyses employing UVvisible diffuse reflectance and Fourier transform infrared spectroscopy were performed on unaged and aged model samples in order to obtain additional information on the physicochemical changes induced by the aging treatment.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000313668400032 Publication Date 2012-10-10
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0003-2700; 5206-882x ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 6.32 Times cited 49 Open Access
Notes ; This research was supported by grants from ESRF (experiment EC-799), the Interuniversity Attraction Poles Programme-Belgian Science Policy (IUAP VI/16), and the BELSPO-SDD S2-ART (SD/RI/04) project. The text also presents results from GOA “XANES meets ELNES” (Research Fund University of Antwerp, Belgium) and FWO (Brussels, Belgium) projects G.0704.08 and G.01769.09. The EU FP7 programme CHARISMA (Grant Agreement 228330) and MIUR (PRIN08, Materiali e sistemi innovativi per la conservazione dell'arte contemporanea 2008 FFXXN9) are also acknowledged. ; Approved Most recent IF: 6.32; 2013 IF: 5.825
Call Number UA @ admin @ c:irua:110471 Serial 5569
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Author (up) Monico, L.; Rosi, F.; Miliani, C.; Daveri, A.; Brunetti, B.G.
Title Non-invasive identification of metal-oxalate complexes on polychrome artwork surfaces by reflection mid-infrared spectroscopy Type A1 Journal article
Year 2013 Publication Spectrochimica acta: part A: molecular and biomolecular spectroscopy Abbreviated Journal
Volume 116 Issue Pages 270-280
Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Abstract In this work a reflection mid-infrared spectroscopy study of twelve metal-oxalate complexes, of interest in art conservation science as alteration compounds, was performed. Spectra of the reference materials highlighted the presence of derivative-like and/or inverted features for the fundamental vibrational modes as result of the main contribution from the surface component of the reflected light. In order to provide insights in the interpretation of theses spectral distortions, reflection spectra were compared with conventional transmission ones. The Kramers-Kronig (KK) algorithm, employed to correct for the surface reflection distortions, worked properly only for the derivative-like bands. Therefore, to pay attention to the use of this algorithm when interpreting the reflection spectra is recommended. The outcome of this investigation was exploited to discriminate among different oxalates on thirteen polychrome art-works analyzed in situ by reflection mid-infrared spectroscopy. The visualization of the v(s)(CO) modes (1400-1200 cm(-1)) and low wavenumber bands (below 900 cm(-1)) in the raw reflection profiles allowed Ca, Cu and Zn oxalates to be identified. Further information about the speciation of different hydration forms of calcium oxalates were obtained by using the KK transform. The work proves reflection mid-infrared spectroscopy to be a reliable and sensitive spectro-analytical method for identifying and mapping different metal-oxalate alteration compounds on the surface of artworks, thus providing conservation scientists with a non-invasive tool to obtain information on the state of conservation and causes of alteration of artworks. (C) 2013 Elsevier B.V. All rights reserved.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000326207900035 Publication Date 2013-07-12
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1386-1425 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:112701 Serial 8313
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Author (up) Mortier, S.T.F.C.; Van Hoey, S.; Cierkens, K.; Gernaey, K.V.; Seuntjens, P.; De Baets, B.; De Beer, T.; Nopens, I.
Title A GLUE uncertainty analysis of a drying model of pharmaceutical granules Type A1 Journal article
Year 2013 Publication European journal of pharmaceutics and biopharmaceutics Abbreviated Journal
Volume 85 Issue 3:b Pages 984-995
Keywords A1 Journal article; Pharmacology. Therapy; Sustainable Energy, Air and Water Technology (DuEL)
Abstract A shift from batch processing towards continuous processing is of interest in the pharmaceutical industry. However, this transition requires detailed knowledge and process understanding of all consecutive unit operations in a continuous manufacturing line to design adequate control strategies. This can be facilitated by developing mechanistic models of the multi-phase systems in the process. Since modelling efforts only started recently in this field, uncertainties about the model predictions are generally neglected. However, model predictions have an inherent uncertainty (i.e. prediction uncertainty) originating from uncertainty in input data, model parameters, model structure, boundary conditions and software. In this paper, the model prediction uncertainty is evaluated for a model describing the continuous drying of single pharmaceutical wet granules in a six-segmented fluidized bed drying unit, which is part of the full continuous from-powder-to-tablet manufacturing line (Consigma (TM), GEA Pharma Systems). A validated model describing the drying behaviour of a single pharmaceutical granule in two consecutive phases is used. First of all, the effect of the assumptions at the particle level on the prediction uncertainty is assessed. Secondly, the paper focuses on the influence of the most sensitive parameters in the model. Finally, a combined analysis (particle level plus most sensitive parameters) is performed and discussed. To propagate the uncertainty originating from the parameter uncertainty to the model output, the Generalized Likelihood Uncertainty Estimation (GLUE) method is used. This method enables a modeller to incorporate the information obtained from the experimental data in the assessment of the uncertain model predictions and to find a balance between model performance and data precision. A detailed evaluation of the obtained uncertainty analysis results is made with respect to the model structure, interactions between parameters and uncertainty boundaries. (C) 2013 Elsevier B.V. All rights reserved.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000330200800019 Publication Date 2013-03-29
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0939-6411 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:114876 Serial 8005
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Author (up) Mourdikoudis, S.; Chirea, M.; Altantzis, T.; Pastoriza-Santos, I.; Perez-Juste, J.; Silva, F.; Bals, S.; Liz-Marzan, L.M.
Title Dimethylformamide-mediated synthesis of water-soluble platinum nanodendrites for ethanol oxidation electrocatalysis Type A1 Journal article
Year 2013 Publication Nanoscale Abbreviated Journal Nanoscale
Volume 5 Issue 11 Pages 4776-4784
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract Herein we describe the synthesis of water-soluble platinum nanodendrites in dimethylformamide (DMF), in the presence of polyethyleneimine (PEI) as a stabilizing agent. The average size of the dendrites is in the range of 20-25 nm while their porosity can be tuned by modifying the concentration of the metal precursor. Electron tomography revealed different crystalline orientations of nanocrystallites in the nanodendrites and allowed a better understanding of their peculiar branching and porosity. The high surface area of the dendrites (up to 22 m(2) g(-1)) was confirmed by BET measurements, while X-ray diffraction confirmed the abundance of high-index facets in the face-centered-cubic crystal structure of Pt. The prepared nanodendrites exhibit excellent performance in the electrocatalytic oxidation of ethanol in alkaline solution. Sensing, selectivity, cycleability and great tolerance toward poisoning were demonstrated by cyclic voltammetry measurements.
Address
Corporate Author Thesis
Publisher Place of Publication Cambridge Editor
Language Wos 000319008700028 Publication Date 2013-04-03
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2040-3364;2040-3372; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 7.367 Times cited 50 Open Access
Notes Esf; 262348 Esmi Approved Most recent IF: 7.367; 2013 IF: 6.739
Call Number UA @ lucian @ c:irua:109060 Serial 705
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Author (up) Mudronja, D.; Vanmeert, F.; Hellemans, K.; Fazinic, S.; Janssens, K.; Tibljas, D.; Rogosic, M.; Jakovljevic, S.
Title Efficiency of applying ammonium oxalate for protection of monumental limestone by poultice, immersion and brushing methods Type A1 Journal article
Year 2013 Publication Applied physics A : materials science & processing Abbreviated Journal Appl Phys A-Mater
Volume 111 Issue 1 Pages 109-119
Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Abstract Samples of cretaceous limestone have been treated with three application methods (poultice, immersion and brushing) using different concentrations of ammonium oxalate solution (AmOx) and varying treatment time in order to test the efficiency of surface and in-depth formation of a protective layer of calcium oxalate (CaOx). Synchrotron-based microanalytical techniques (SR-mu XRD with 12.5 mu mx7.5 mu m (HxV) probe size, SR-mu FTIR with 10 mu mx10 mu m and 8 mu mx20 mu m probe sizes) and laboratory mu FTIR, XRD and SEM have been employed for analysis of the treated samples. Synchrotron-based techniques showed variations in the CaOx distribution along the surface on a micrometer scale. All treatments resulted in the development of a CaOx layer with a maximum thickness of approximately 40 mu m. Application by the brushing method with 10 1-min applications with 5-min breaks during one hour showed a development of the calcium oxalate layer equivalent to the poultice treatment taking 10 h. This treatment could be preferred for large marble or limestone surfaces where poultice usage is economically not feasible.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000316075700014 Publication Date 2012-10-29
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0947-8396 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 1.455 Times cited 13 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) project nos. G.0704.08 and G.01769.09. The research leading to these results has received financial support by the Access to Research Infrastructures activity in the 7th Framework Programme of the EU (CHARISMA Grant Agreement No. 228330). ; Approved Most recent IF: 1.455; 2013 IF: 1.694
Call Number UA @ admin @ c:irua:108262 Serial 5584
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Author (up) Muñoz, W.A.; Covaci, L.; Peeters, F.M.
Title Superconducting current and proximity effect in ABA and ABC multilayer graphene Josephson junctions Type A1 Journal article
Year 2013 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B
Volume 88 Issue 88 Pages 214502
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract Using a numerical tight-binding approach based on the Chebyshev–Bogoliubov–de Gennes method we describe Josephson junctions made of multilayer graphene contacted by top superconducting gates. Both Bernal (ABA) and rhombohedral (ABC) stacking are considered and we find that the type of stacking has a strong effect on the proximity effect and the supercurrent flow. For both cases the pair amplitude shows a polarization between dimer and nondimer atoms, being more pronounced for rhombohedral stacking. Even though the proximity effect in nondimer sites is enhanced when compared to single-layer graphene, we find that the supercurrent is suppressed. The spatial distribution of the supercurrent shows that for Bernal stacking the current flows only in the topmost layers while for rhombohedral stacking the current flows throughout the whole structure.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000328569900004 Publication Date 2013-12-02
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1098-0121;1550-235X; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.836 Times cited 4 Open Access
Notes This work was supported by the Flemish Science Foundation (FWO-Vl) and the Methusalem funding of the Flemish Government Approved Most recent IF: 3.836; 2013 IF: 3.664
Call Number CMT @ cmt @ c:irua:128896 Serial 3962
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Author (up) Muñoz, W.A.; Covaci, L.; Peeters, F.M.
Title Tight-binding description of intrinsic superconducting correlations in multilayer graphene Type A1 Journal article
Year 2013 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B
Volume 87 Issue 13 Pages 134509-7
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract Using highly efficient GPU-based simulations of the tight-binding Bogoliubov-de Gennes equations we solve self-consistently for the pair correlation in rhombohedral (ABC) and Bernal (ABA) multilayer graphene by considering a finite intrinsic s-wave pairing potential. We find that the two different stacking configurations have opposite bulk/surface behavior for the order parameter. Surface superconductivity is robust for ABC stacked multilayer graphene even at very low pairing potentials for which the bulk order parameter vanishes, in agreement with a recent analytical approach. In contrast, for Bernal stacked multilayer graphene, we find that the order parameter is always suppressed at the surface and that there exists a critical value for the pairing potential below which no superconducting order is achieved. We considered different doping scenarios and find that homogeneous doping strongly suppresses surface superconductivity while nonhomogeneous field-induced doping has a much weaker effect on the superconducting order parameter. For multilayer structures with hybrid stacking (ABC and ABA) we find that when the thickness of each region is small (few layers), high-temperature surface superconductivity survives throughout the bulk due to the proximity effect between ABC/ABA interfaces where the order parameter is enhanced. DOI: 10.1103/PhysRevB.87.134509
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000317390000006 Publication Date 2013-04-11
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1098-0121;1550-235X; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.836 Times cited 37 Open Access
Notes ; This work was supported by the Flemish Science Foundation (FWO-Vl) and the Methusalem funding of the Flemish Government. ; Approved Most recent IF: 3.836; 2013 IF: 3.664
Call Number UA @ lucian @ c:irua:108469 Serial 3660
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Author (up) Neek-Amal, M.; Beheshtian, J.; Sadeghi, A.; Michel, K.H.; Peeters, F.M.
Title Boron nitride mono layer : a strain-tunable nanosensor Type A1 Journal article
Year 2013 Publication The journal of physical chemistry: C : nanomaterials and interfaces Abbreviated Journal J Phys Chem C
Volume 117 Issue 25 Pages 13261-13267
Keywords A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT)
Abstract The influence of triaxial in-plane strain on the electronic properties of a hexagonal boron-nitride sheet is investigated using density functional theory. Different from graphene, the triaxial strain localizes the molecular orbitals of the boron-nitride flake in its center depending on the direction of the applied strain. The proposed technique for localizing the molecular orbitals that are close to the Fermi level in the center of boron nitride flakes can be used to actualize engineered nanosensors, for instance, to selectively detect gas molecules. We show that the central part of the strained flake adsorbs polar molecules more strongly as compared with an unstrained sheet.
Address
Corporate Author Thesis
Publisher Place of Publication Washington, D.C. Editor
Language Wos 000321236400041 Publication Date 2013-06-03
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1932-7447;1932-7455; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 4.536 Times cited 38 Open Access
Notes ; This work was supported by the EU-Marie Curie IIF postdoc Fellowship/299855 (for M.N.-A.), the ESF EuroGRAPHENE project CONGRAN, the Flemish Science Foundation (FWO-VI), and the Methusalem Funding of the Flemish government. AS. would like to thank the Universiteit Antwerpen for its hospitality. ; Approved Most recent IF: 4.536; 2013 IF: 4.835
Call Number UA @ lucian @ c:irua:109829 Serial 249
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Author (up) Neek-Amal, M.; Beheshtian, J.; Shayeganfar, F.; Singh, S.K.; Los, J.H.; Peeters, F.M.
Title Spiral graphone and one-sided fluorographene nanoribbons Type A1 Journal article
Year 2013 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B
Volume 87 Issue 7 Pages 075448-8
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract The instability of a free-standing one-sided hydrogenated/fluorinated graphene nanoribbon, i.e., graphone/fluorographene, is studied using ab initio, semiempirical, and large-scale molecular dynamics simulations. Free-standing semi-infinite armchairlike hydrogenated/fluorinated graphene (AC-GH/AC-GF) and boatlike hydrogenated/fluorinated graphene (B-GH/B-GF) (nanoribbons which are periodic along the zigzag direction) are unstable and spontaneously transform into spiral structures. We find that rolled, spiral B-GH and B-GF are energetically more favorable than spiral AC-GH and AC-GF which is opposite to the double-sided flat hydrogenated/fluorinated graphene, i.e., graphane/fluorographene. We found that the packed, spiral structures exhibit an unexpected localized highest occupied molecular orbital and lowest occupied molecular orbital at the edges with increasing energy gap during rolling. These rolled hydrocarbon structures are stable beyond room temperature up to at least T = 1000 K within our simulation time of 1 ns. DOI: 10.1103/PhysRevB.87.075448
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000315481800005 Publication Date 2013-02-27
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1098-0121;1550-235X; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.836 Times cited 14 Open Access
Notes ; We thank A. Sadeghi, M. R. Ejtehadi, and J. Amini for their useful comments. This work is supported by the ESF EuroGRAPHENE project CONGRAN and the Flemish Science Foundation (FWO-Vl). M.N.-A. is supported by a EU-Marie Curie IIF fellowship program Grant No. 299855. ; Approved Most recent IF: 3.836; 2013 IF: 3.664
Call Number UA @ lucian @ c:irua:107654 Serial 3106
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Author (up) Neek-Amal, M.; Covaci, L.; Shakouri, K.; Peeters, F.M.
Title Electronic structure of a hexagonal graphene flake subjected to triaxial stress Type A1 Journal article
Year 2013 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B
Volume 88 Issue 11 Pages 115428
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract The electronic properties of a triaxially strained hexagonal graphene flake with either armchair or zigzag edges are investigated using molecular dynamics simulations and tight-binding calculations. We found that (i) the pseudomagnetic field in strained graphene flakes is not uniform neither in the center nor at the edge of zigzag terminated flakes, (ii) the pseudomagnetic field is almost zero in the center of armchair terminated flakes but increases dramatically near the edges, (iii) the pseudomagnetic field increases linearly with strain, for strains lower than 15% but increases nonlinearly beyond it, (iv) the local density of states in the center of the zigzag hexagon exhibits pseudo-Landau levels with broken sublattice symmetry in the zeroth pseudo-Landau level, and in addition there is a shift in the Dirac cone due to strain induced scalar potentials, and (v) there is size effect in pseudomagnetic field. This study provides a realistic model of the electronic properties of inhomogeneously strained graphene where the relaxation of the atomic positions is correctly included together with strain induced modifications of the hopping terms up to next-nearest neighbors.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000324690400008 Publication Date 2013-09-24
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1098-0121;1550-235X; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.836 Times cited 46 Open Access
Notes ; This work was supported by the EU-Marie Curie IIF postdoctoral Fellowship/ 299855 (for M.N.-A.), the ESF EuroGRAPHENE project CONGRAN, the Flemish Science Foundation (FWO-Vl) and the Methusalem Funding of the Flemish government. ; Approved Most recent IF: 3.836; 2013 IF: 3.664
Call Number UA @ lucian @ c:irua:111168 Serial 1011
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Author (up) Neek-Amal, M.; Sadeghi, A.; Berdiyorov, G.R.; Peeters, F.M.
Title Realization of free-standing silicene using bilayer graphene Type A1 Journal article
Year 2013 Publication Applied physics letters Abbreviated Journal Appl Phys Lett
Volume 103 Issue 26 Pages 261904-4
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract The available synthesized silicene-like structures have been only realized on metallic substrates which are very different from the standalone buckled silicene, e. g., the Dirac cone of silicene is destroyed due to lattice distortion and the interaction with the substrate. Using graphene bilayer as a scaffold, a route is proposed to synthesize silicene with electronic properties decoupled from the substrate. The buckled hexagonal arrangement of silicene between the graphene layers is found to be very similar to the theoretically predicted standalone buckled silicene which is only very weakly van der Waals coupled to the graphene layers with a graphite-like interlayer distance of 3.42 angstrom and without any lattice distortion. We found that these stacked layers are stable well above room temperature. (C) 2013 AIP Publishing LLC.
Address
Corporate Author Thesis
Publisher American Institute of Physics Place of Publication New York, N.Y. Editor
Language Wos 000329977400022 Publication Date 2013-12-26
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0003-6951;1077-3118; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.411 Times cited 74 Open Access
Notes ; This work was supported by the Flemish Science Foundation (FWO-Vl) and the Methusalem Foundation of the Flemish Government. M.N.-A. was supported by the EU-Marie Curie IIF postdoc Fellowship/299855. ; Approved Most recent IF: 3.411; 2013 IF: 3.515
Call Number UA @ lucian @ c:irua:114849 Serial 2837
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Author (up) Neyts, E.C.; Bogaerts, A.
Title Combining molecular dynamics with Monte Carlo simulations : implementations and applications Type A1 Journal article
Year 2013 Publication Theoretical chemistry accounts : theory, computation, and modeling Abbreviated Journal Theor Chem Acc
Volume 132 Issue 2 Pages 1320-12
Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract In this contribution, we present an overview of the various techniques for combining atomistic molecular dynamics with Monte Carlo simulations, mainly in the context of condensed matter systems, as well as a brief summary of the main accelerated dynamics techniques. Special attention is given to the force bias Monte Carlo technique and its combination with molecular dynamics, in view of promising recent developments, including a definable timescale. Various examples of the application of combined molecular dynamics / Monte Carlo simulations are given, in order to demonstrate the enhanced simulation efficiency with respect to either pure molecular dynamics or Monte Carlo.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000318294700010 Publication Date 2012-12-19
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1432-881X;1432-2234; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 1.89 Times cited 27 Open Access
Notes Approved Most recent IF: 1.89; 2013 IF: 2.143
Call Number UA @ lucian @ c:irua:104725 Serial 404
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Author (up) Neyts, E.C.; Ostrikov, K.; Han, Z.J.; Kumar, S.; van Duin, A.C.T.; Bogaerts, A.
Title Defect healing and enhanced nucleation of carbon nanotubes by low-energy ion bombardment Type A1 Journal article
Year 2013 Publication Physical review letters Abbreviated Journal Phys Rev Lett
Volume 110 Issue 6 Pages 065501-65505
Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract Structural defects inevitably appear during the nucleation event that determines the structure and properties of single-walled carbon nanotubes. By combining ion bombardment experiments with atomistic simulations we reveal that ion bombardment in a suitable energy range allows these defects to be healed resulting in an enhanced nucleation of the carbon nanotube cap. The enhanced growth of the nanotube cap is explained by a nonthermal ion-induced graphene network restructuring mechanism.
Address
Corporate Author Thesis
Publisher Place of Publication New York, N.Y. Editor
Language Wos 000314687300022 Publication Date 2013-02-07
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0031-9007;1079-7114; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 8.462 Times cited 50 Open Access
Notes Approved Most recent IF: 8.462; 2013 IF: 7.728
Call Number UA @ lucian @ c:irua:105306 Serial 616
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Author (up) Neyts, E.C.; van Duin, A.C.T.; Bogaerts, A.
Title Formation of single layer graphene on nickel under far-from-equilibrium high flux conditions Type A1 Journal article
Year 2013 Publication Nanoscale Abbreviated Journal Nanoscale
Volume 5 Issue 16 Pages 7250-7255
Keywords A1 Journal article; Engineering sciences. Technology; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract We investigate the theoretical possibility of single layer graphene formation on a nickel surface at different substrate temperatures under far-from-equilibrium high precursor flux conditions, employing state-of-the-art hybrid reactive molecular dynamics/uniform acceptance force bias Monte Carlo simulations. It is predicted that under these conditions, the formation of a single layer graphene-like film may proceed through a combined depositionsegregation mechanism on a nickel substrate, rather than by pure surface segregation as is typically observed for metals with high carbon solubility. At 900 K and above, nearly continuous graphene layers are obtained. These simulations suggest that single layer graphene deposition is theoretically possible on Ni under high flux conditions.
Address
Corporate Author Thesis
Publisher Place of Publication Cambridge Editor
Language Wos 000322315600019 Publication Date 2013-04-26
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2040-3364;2040-3372; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 7.367 Times cited 25 Open Access
Notes Approved Most recent IF: 7.367; 2013 IF: 6.739
Call Number UA @ lucian @ c:irua:109249 Serial 1264
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Author (up) Nuyts, G.; Cagno, S.; Hellemans, K.; Veronesi, G.; Cotte, M.; Janssens, K.
Title Study of the early stages of Mn intrusion in corroded glass by means of combined SR FTIR/\muXRF imaging and XANES spectroscopy Type P1 Proceeding
Year 2013 Publication Procedia Chemistry T2 – Youth in Conservation of Cultural Heritage Conference (YOCOCU), June 18-20, 2012, University of Antwerp, Antwerp, Belgium Abbreviated Journal
Volume Issue Pages 239-247
Keywords P1 Proceeding; Engineering sciences. Technology; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Abstract Historical glass, especially medieval glass, can undergo weathering under the influence of time and environmental conditions. The aim of this investigation was to better understand the processes involved in this natural degradation process by studying artificially altered glass samples prepared for the use of evaluation of conservation methods. Non-durable glass sensors produced by the Fraunhofer Institute (type M1.0) were used as a starting material for artificial alteration. These were immersed in acidic (pH = 0, 2, 4) and neutral solutions (1 h – 8 h). In a second stage the glass samples were immersed in a 0.5 M MnCl2 solution (24 h, 48 h and 72 h), allowing intrusion of Mn from the solution into the gel layer. The samples were characterized at different stages with reflectance FTIR spectroscopy, mu XRF mapping and mu XANES. All measurements were carried out at ESRF, beamline ID21. Reflectance FTIR spectroscopy measurements were performed in the 800 4000 cm(-1) range. Cluster analysis of the resulting maps evidenced the rapid growth of the gel layer in strong acidic conditions. The average spectra for each cluster feature show for the original glass a strong Si-O- stretching band between 900 and 1000 cm(-1), whereas the gel layer could be identified by the increasing Si-O-Si bands around 1100 and 1250 cm(-1). mu XRF maps were recorded at different stages of the experiment at energies around the Mn-K edge (6.539 keV) and with a step size of 2 by 2 m. These confirm the leaching of K+ and Ca+2 from the glass and the intrusion of Mn from the solution. Mn was found throughout the entire gel layer, but with a concentration gradient peaking at the surface. XANES point measurements were recorded at various points where Mn was present. No spatial variation was found, but linear combination fitting of the spectra with various Mn reference compounds indicated that Mn2+Mn23+O4 is the main Mn compound in the gel layer, as was hypothesised by Watkinson et al. The standard corroded glass samples studied here can be used for the evaluation of conservation treatments in follow-up experiments. (C) 2013 The Authors. Published by Elsevier B.V. Selection and peer-review under responsibility of the IA-CS (Italian Association of Conservation Scientists) and University of Antwerp
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000321673900030 Publication Date 2013-04-17
Series Editor Series Title Abbreviated Series Title
Series Volume 8 Series Issue Edition
ISSN 1876-6196 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor Times cited 4 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. We gratefully acknowledge ESRF for granting beamtime (experiment EC873). ; Approved Most recent IF: NA
Call Number UA @ admin @ c:irua:109871 Serial 5851
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Author (up) Nuyts, G.; Cagno, S.; Jaroszewicz, J.; Wouters, H.; De Vis, K.; Caen, J.; Janssens, K.
Title High-resolution desktop microcomputed tomography for the evaluation of reducing treatments on historical glass suffering from manganese browning Type H2 Book chapter
Year 2013 Publication Abbreviated Journal
Volume Issue Pages 201-209
Keywords H2 Book chapter; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation); Antwerp Cultural Heritage Sciences (ARCHES)
Abstract Historical glass, especially non-durable mediaeval glass, can undergo corrosion. This sometimes results in the formation of dark-coloured manganese-rich inclusions or stains that reduce the transparency of the glass. A conservation treatment with reducing or chelating agents may be considered with the aim of improving the transparency. In this paper, high-resolution desktop microcomputed tomography (µCT) is used in combination with element-specific twodimensional imaging methods for in situ monitoring of manganese removal by hydroxylamine hydrochloride from an archaeological stained-glass sample suffering from manganese browning and from artificially corroded model glass samples. µCT also proved itself useful for the study of the (re-)penetration of manganese into the gel layer during artificial corrosion of a model glass.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos Publication Date
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN 978-90-8932-113-8 Additional Links UA library record
Impact Factor Times cited Open Access
Notes Approved Most recent IF: NA
Call Number UA @ admin @ c:irua:114604 Serial 5641
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Author (up) Oh, H.; Gennett, T.; Atanassov, P.; Kurttepeli, M.; Bals, S.; Hurst, K.E.; Hirscher, M.
Title Hydrogen adsorption properties of platinum decorated hierarchically structured templated carbons Type A1 Journal article
Year 2013 Publication Microporous and mesoporous materials: zeolites, clays, carbons and related materials Abbreviated Journal Micropor Mesopor Mat
Volume 177 Issue Pages 66-74
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract In this report, the possibility of Pt catalytic activity for the dissociation of hydrogen molecules and subsequent hydrogen adsorption on sucrose templated carbon at ambient temperature has been studied. In order to investigate Pt catalytic effect for hydrogen storage solely, 6.8 wt.% Pt-doped (Pt/TC) and pure templated carbon (TC) possessing almost identical specific surface area (SSA) and pore volume (Vp) have been successfully synthesized. Since both Pt/TC and TC shares for their textural properties (e.g. SSA and Vp), any difference of hydrogen adsorption characteristic and storage capacity can be ascribed to the presence of Pt nanoparticles. Both samples are characterized by various techniques such as powder Xray diffraction, ICP-OES, Raman spectroscopy, transmission electron microscopy, cryogenic thermal desorption spectroscopy, low-pressure high-resolution hydrogen and nitrogen BET and high-pressure hydrogen adsorption isotherms in a Sieverts' apparatus. By applying hydrogen and deuterium isotope mixture, cryogenic thermal desorption spectroscopy point to a Pt catalytic activity for the dissociation of hydrogen molecules. Furthermore, the hydrogen adsorption isotherms at RT indicate an enhancement of the initial hydrogen adsorption kinetics in Pt-doped system. However, the hydrogen storage capacity of Pt/TC exhibits a negligible enhancement with a strong hysteresis, suggesting no connection between the spillover effect and a feasible hydrogen storage enhancement. (C) 2013 Elsevier Inc. All rights reserved.
Address
Corporate Author Thesis
Publisher Place of Publication Amsterdam Editor
Language Wos 000322293000012 Publication Date 2013-04-28
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1387-1811; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.615 Times cited 25 Open Access
Notes 262348 ESMI; COST Action MP1103 Approved Most recent IF: 3.615; 2013 IF: 3.209
Call Number UA @ lucian @ c:irua:109758 Serial 1532
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Author (up) Oleshko, V.P.; Gijbels, R.; Amelinckx, S.
Title Electron microscopy, nanoscopy, and scanning micro- and nanoanalysis Type H1 Book chapter
Year 2013 Publication Abbreviated Journal
Volume Issue Pages 1-44
Keywords H1 Book chapter; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract
Address
Corporate Author Thesis
Publisher Wiley Place of Publication Chichester Editor
Language Wos Publication Date 0000-00-00
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN 9780470027318 Additional Links UA library record
Impact Factor Times cited Open Access
Notes Approved Most recent IF: NA
Call Number UA @ lucian @ c:irua:107031 Serial 957
Permanent link to this record
 

 
Author (up) Orlova, N.V.; Shanenko, A.A.; Milošević, M.V.; Peeters, F.M.; Vagov, A.V.; Axt, V.M.
Title Ginzburg-Landau theory for multiband superconductors : microscopic derivation Type A1 Journal article
Year 2013 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B
Volume 87 Issue 13 Pages 134510-134518
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract A procedure to derive the Ginzburg-Landau (GL) theory from the multiband BCS Hamiltonian is developed in a general case with an arbitrary number of bands and arbitrary interaction matrix. It combines the standard Gor'kov truncation and a subsequent reconstruction in order to match accuracies of the obtained terms. This reconstruction recovers the phenomenological GL theory as obtained from the Landau model of phase transitions but offers explicit microscopic expressions for the relevant parameters. Detailed calculations are presented for a three-band system treated as a prototype multiband superconductor. It is demonstrated that the symmetry in the coupling matrix may lead to the chiral ground state with the phase frustration, typical for systems with broken time-reversal symmetry. DOI: 10.1103/PhysRevB.87.134510
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000317586700002 Publication Date 2013-04-16
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1098-0121;1550-235X; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.836 Times cited 57 Open Access
Notes ; This work was supported by the “Odysseus” Program of the Flemish Government and the Flemish Science Foundation (FWO-Vl). A.A.S. acknowledges useful discussions with D. Neilson. ; Approved Most recent IF: 3.836; 2013 IF: 3.664
Call Number UA @ lucian @ c:irua:108464 Serial 1344
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Author (up) Ostrikov, K.; Neyts, E.C.; Meyyappan, M.
Title Plasma nanoscience : from nano-solids in plasmas to nano-plasmas in solids Type A1 Journal article
Year 2013 Publication Advances in physics Abbreviated Journal Adv Phys
Volume 62 Issue 2 Pages 113-224
Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract The unique plasma-specific features and physical phenomena in the organization of nanoscale soild-state systems in a broad range of elemental composition, structure, and dimensionality are critically reviewed. These effects lead to the possibility to localize and control energy and matter at nanoscales and to produce self-organized nano-solids with highly unusual and superior properties. A unifying conceptual framework based on the control of production, transport, and self-organization of precursor species is introduced and a variety of plasma-specific non-equilibrium and kinetics-driven phenomena across the many temporal and spatial scales is explained. When the plasma is localized to micrometer and nanometer dimensions, new emergent phenomena arise. The examples range from semiconducting quantum dots and nanowires, chirality control of single-walled carbon nanotubes, ultra-fine manipulation of graphenes, nano-diamond, and organic matter to nano-plasma effects and nano-plasmas of different states of matter.
Address
Corporate Author Thesis
Publisher Place of Publication London Editor
Language Wos 000320913600001 Publication Date 2013-06-18
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0001-8732;1460-6976; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 21.818 Times cited 380 Open Access
Notes Approved Most recent IF: 21.818; 2013 IF: 18.062
Call Number UA @ lucian @ c:irua:108723 Serial 2639
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Author (up) Ovsyannikov, S.V.; Abakumov, A.M.; Tsirlin, A.A.; Schnelle, W.; Egoavil, R.; Verbeeck, J.; Van Tendeloo, G.; Glazyrin, K.V.; Hanfland, M.; Dubrovinsky, L.
Title Perovskite-like Mn2O3 : a path to new manganites Type A1 Journal article
Year 2013 Publication Angewandte Chemie Abbreviated Journal Angew Chem Int Edit
Volume 52 Issue 5 Pages 1494-1498
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Korund-artiges ε-Mn2O3 und Perowskit-artiges ζ-Mn2O3, zwei neue Phasen von Mn2O3, wurden unter hohen Drücken bei hohen Temperaturen synthetisiert. Die Manganatome können vollständig die A- und B-Positionen der Perowskitstruktur besetzen. ζ-Mn2O3 (siehe Bild, A-Positionsordnung) enthält Mn in den drei Oxidationsstufen +II, +III und +IV.
Address
Corporate Author Thesis
Publisher Place of Publication Weinheim Editor
Language Wos 000313913300027 Publication Date 2012-12-22
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1433-7851; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 11.994 Times cited 84 Open Access
Notes This work was supported by the DFG (project OV-110/1-1), Alexander von Humboldt foundation, European Union Council (FP7)-Grant no. 246102 IFOX, European Research Council (FP7)-ERC Starting Grant no. 278510 VORTEX and ERC Grant no. 246791-COUNTATOMS, and Hercules fund from the Flemish Government. ECASJO_; Approved Most recent IF: 11.994; 2013 IF: 11.336
Call Number UA @ lucian @ c:irua:108765UA @ admin @ c:irua:108765 Serial 2573
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Author (up) Palacios, O.M.; van Meel, K.; Van Grieken, R.; Marcó P., L.-M.; Vázquez, C.
Title Characterization of black volcanites from the Limay river basin, Patagonia, Argentina, using energy dispersive X-ray fluorescence spectrometry : an aid to infer human group mobility Type A1 Journal article
Year 2013 Publication Journal of radioanalytical and nuclear chemistry Abbreviated Journal
Volume 298 Issue 2 Pages 1245-1255
Keywords A1 Journal article; Engineering sciences. Technology; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Abstract The investigation of hunter-gatherers archaeological sites in the Limay river basin, Patagonia, Argentina, raised questions concerning the lithic technology. The chemical characterization of artifacts, rocks and possible sources of provenances could help to elucidate the hunter-gatherer mobility. In three archaeological sitesRincón Chico 2 (RCh2/87; 14C 710 ± 60 BP), Cueva Traful I (CTI; 14C 9430 ± 230 BP) and Casa de Piedra de Ortega (CPO; 14C 2840 ± 80 BP), tools and debitage or discarded flakes made in black volcanic rock have been found. Nearby an extensive rock outcrop of black volcanite, Paso Limay quarry (CPL), with similar characteristics was located. Samples coming from these four sites were analyzed by energy dispersive X-ray fluorescence spectrometry. This characterization allowed the geochemical classification of the lithic material and to correlate the samples with the suspected source after a previous statistical analysis. The majority of the samples were classified as dacites and rhyolites. Only samples coming from CPO site, the closest place to CPL were made exclusively with the quarry rocks. A set of five samples from RCh2/87 and two samples from CTI appear to have same chemical composition as CPL in spite of this site is placed in the opposite bank of the Limay river suggesting that hunter-gatherers could accede to the quarry, eventually. Finally, only a set of five samples coming from RCh2/87 and CTI do not group with the quarry. This fact evidences the existence of secondary sources of supply. The information of this research allowed inferring ancient human mobility patterns in the region.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000325624300061 Publication Date 2013-07-25
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0236-5731; 1588-2780 ISBN Additional Links UA library record; WoS full record
Impact Factor Times cited Open Access
Notes Approved no
Call Number UA @ admin @ c:irua:109743 Serial 7619
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Author (up) Park, K.; De Beule, C.; Partoens, B.
Title The ageing effect in topological insulators : evolution of the surface electronic structure of Bi2Se3 upon K adsorption Type A1 Journal article
Year 2013 Publication New journal of physics Abbreviated Journal New J Phys
Volume 15 Issue Pages 113031-16
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract Topological insulators (TIs) have attracted a lot of interest in recent years due to their topologically protected surface states, as well as exotic proximity-induced phenomena and device applications for TI heterostructures. Since the first experimental studies of TIs, angle-resolved photoemission spectra (ARPES) showed that the electronic structure of the topological surface states significantly changes as a function of time after cleavage. The origin and underlying mechanism of this ageing effect are still under debate, despite its importance. Here we investigate the evolution of the surface Dirac cone for Bi2Se3 films upon asymmetric potassium (K) adsorption, using density-functional theory and a tight-binding model. We find that the K adatoms induce short-ranged downward band bending within 2-3 nm from the surface, due to charge transfer from the adatoms to the TI. These findings are in contrast to earlier proposals in the literature, that propose a long-ranged downward band bending up to 15 nm from the surface. Furthermore, as the charge transfer increases, we find that a new Dirac cone, localized slightly deeper into the TI than the original one, appears at the K-adsorbed surface, originating from strong Rashba-split conduction-band states. Our results suggest possible reinterpretations of experiments because the new Dirac cone might have been observed in ARPES measurements instead of the original one that appears immediately after cleavage. Our findings are consistent with ARPES data and provide insight into building TI-heterostructure devices by varying the band-bending potential or film thickness.
Address
Corporate Author Thesis
Publisher Place of Publication Bristol Editor
Language Wos 000326876100006 Publication Date 2013-11-13
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1367-2630; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.786 Times cited 45 Open Access
Notes ; KP was supported by National Science Foundation grant numbers DMR-0804665 and DMR-1206354 and SDSC Trestles under DMR060009N. CDB was supported by the Research Foundation Flanders (FWO). ; Approved Most recent IF: 3.786; 2013 IF: 3.671
Call Number UA @ lucian @ c:irua:112707 Serial 84
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Author (up) Pathangi, H.; Cherman, V.; Khaled, A.; Sorée, B.; Groeseneken, G.; Witvrouw, A.
Title Towards CMOS-compatible single-walled carbon nanotube resonators Type A1 Journal article
Year 2013 Publication Microelectronic engineering Abbreviated Journal Microelectron Eng
Volume 107 Issue Pages 219-222
Keywords A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT)
Abstract We report a totally CMOS-compatible fabrication technique to assemble horizontally suspended single-walled carbon nanotube (SWCNT) resonators. Individual SWCNTs are assembled in parallel at multiple sites by a technique called dielectrophoresis. The mechanical resonance frequencies of the suspended SWCNTs are in the range of 2035 MHz as determined from the piezoresistive response of the resonators during electrostatic actuation. The resistance of the suspended SWCNT either remains unchanged or increases or decreases significantly as a function of the actuation frequency. This can be explained by the effect the nanotube chirality has on the piezoresistive gauge factor.
Address
Corporate Author Thesis
Publisher Place of Publication Amsterdam Editor
Language Wos 000319855800040 Publication Date 2012-07-02
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0167-9317; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 1.806 Times cited 6 Open Access
Notes ; ; Approved Most recent IF: 1.806; 2013 IF: 1.338
Call Number UA @ lucian @ c:irua:109260 Serial 3685
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Author (up) Peirs, J.; Tirry, W.; Amin-Ahmadi, B.; Coghe, F.; Verleysen, P.; Rabet, L.; Schryvers, D.; Degrieck, J.
Title Microstructure of adiabatic shear bands in Ti6Al4V Type A1 Journal article
Year 2013 Publication Materials characterization Abbreviated Journal Mater Charact
Volume 75 Issue Pages 79-92
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Microstructural deformation mechanisms in adiabatic shear bands in Ti6Al4V are studied using traditional TEM and selected area diffraction, and more advanced microstructural characterisation techniques such as energy dispersive X-ray spectroscopy, high angle annular dark field STEM and conical dark field TEM. The shear bands under investigation are induced in Ti6Al4V samples by high strain rate compression of cylindrical and hat-shaped specimens in a split Hopkinson pressure bar setup. Samples from experiments interrupted at different levels of deformation are used to study the evolution of the microstructure in and nearby the shear bands. From the early stages of adiabatic shear band formation, TEM revealed strongly elongated equiaxed grains in the shear band. These band-like grains become narrower towards the centre of the band and start to fraction even further along their elongated direction to finally result in a nano-crystalline region in the core. In fully developed shear bands, twins and a needle-like martensite morphology are observed near the shear band.
Address
Corporate Author Thesis
Publisher Place of Publication New York Editor
Language Wos 000314860900011 Publication Date 2012-11-07
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1044-5803; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.714 Times cited 56 Open Access
Notes Iuap; Fwo Approved Most recent IF: 2.714; 2013 IF: 1.925
Call Number UA @ lucian @ c:irua:105300 Serial 2065
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Author (up) Petrovic, M.D.; Peeters, F.M.; Chaves, A.; Farias, G.A.
Title Conductance maps of quantum rings due to a local potential perturbation Type A1 Journal article
Year 2013 Publication Journal of physics : condensed matter Abbreviated Journal J Phys-Condens Mat
Volume 25 Issue 49 Pages 495301-495309
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract We performed a numerical simulation of the dynamics of a Gaussian shaped wavepacket inside a small sized quantum ring, smoothly connected to two leads and exposed to a perturbing potential of a biased atomic force microscope tip. Using the Landauer formalism, we calculated conductance maps of this system in the case of single and two subband transport. We explain the main features in the conductance maps as due to the AFM tip influence on the wavepacket phase and amplitude. In the presence of an external magnetic field, the tip modifies the phi(0) periodic Aharonov-Bohm oscillation pattern into a phi(0)/2 periodic Al'tshuler-Aronov-Spivak oscillation pattern. Our results in the case of multiband transport suggest tip selectivity to higher subbands, making them more observable in the total
Address
Corporate Author Thesis
Publisher Place of Publication London Editor
Language Wos 000327181400002 Publication Date 2013-11-01
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0953-8984;1361-648X; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.649 Times cited 12 Open Access
Notes ; This work was supported by the Methusalem programme of the Flemish government, the CNPq-FWO bilateral programme and PNPD and FUNCAP/PRONEX grants. ; Approved Most recent IF: 2.649; 2013 IF: 2.223
Call Number UA @ lucian @ c:irua:112694 Serial 478
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Author (up) Phung, Q.M.; Vancoillie, S.; Pourtois, G.; Swerts, J.; Pierloot, K.; Delabie, A.
Title Atomic layer deposition of ruthenium on a titanium nitride surface : a density functional theory study Type A1 Journal article
Year 2013 Publication The journal of physical chemistry: C : nanomaterials and interfaces Abbreviated Journal J Phys Chem C
Volume 117 Issue 38 Pages 19442-19453
Keywords A1 Journal article; Engineering sciences. Technology; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract Because of its excellent properties in nanotechnology applications, atomic layer deposition of ruthenium (Ru) has been the subject of numerous experimental studies. Recently, two different Ru precursors were compared for plasma-enhanced atomic layer deposition (PEALD) of Ru, and their reactivity was found to be different. Inhibition was observed for bis(ethylcyclopentadienyl)ruthenium (Ru(EtCp)(2)), while nearly linear growth behavior was observed for (methylcyclopentadienyl-pyrrolyl)ruthenium (Ru(MeCp)Py). To understand this difference in reactivity, we investigate the adsorption of RuCp, and RuCpPy (i.e., without substituents) on a TiN surface using calculations based on periodic boundary conditions density functional theory (DFT) combined with experiments based on Rutherford backscattering spectroscopy (RBS). The calculations demonstrate that the RuCpPy precursor chemisorbs on the TiN(100) surface while the RuCp2 precursor only physisorbs. We propose a reaction mechanism for the chemisorption of RuCpPy. The area density of the calculated RuCpPy surface species is compared with the experimental values from RBS. The impact of a H-plasma is also investigated. The DFT calculations and experimental results from RBS provide insight into the adsorption processes of the RuCpPy and RuCp2 precursors on the TiN(100) surface.
Address
Corporate Author Thesis
Publisher Place of Publication Washington, D.C. Editor
Language Wos 000330162500022 Publication Date 2013-08-28
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1932-7447;1932-7455; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 4.536 Times cited 6 Open Access
Notes Approved Most recent IF: 4.536; 2013 IF: 4.835
Call Number UA @ lucian @ c:irua:114855 Serial 170
Permanent link to this record