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Author Van der Donck, M.; Peeters, F.M.; Van Duppen, B.
Title Transport properties of bilayer graphene in a strong in-plane magnetic field Type A1 Journal article
Year 2016 Publication Physical review B Abbreviated Journal Phys Rev B
Volume 93 Issue 93 Pages 115423
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract A strong in-plane magnetic field drastically alters the low-energy spectrum of bilayer graphene by separating the parabolic energy dispersion into two linear Dirac cones. The effect of this dramatic change on the transport properties strongly depends on the orientation of the in-plane magnetic field with respect to the propagation direction of the charge carriers and the angle at which they impinge on the electrostatic potentials. For magnetic fields oriented parallel to the potential boundaries an additional propagating mode that results from the splitting into Dirac cones enhances the transmission probability for charge carriers tunneling through the potentials and increases the corresponding conductance. Our results show that the chiral suppression of transmission at normal incidence, reminiscent of bilayer graphene's 2 pi Berry phase, is turned into a chiral enhancement when the magnetic field increases, thus indicating a transition from a bilayer to a monolayer-like system at normal incidence. Further, we find that the typical transmission resonances stemming from confinement in a potential barrier are shifted to higher energy and are eventually transformed into antiresonances with increasing magnetic field. For magnetic fields oriented perpendicular to the potential boundaries we find a very pronounced transition from a bilayer system to two separated monolayer-like systems with Klein tunneling emerging at certain incident angles symmetric around 0, which also leaves a signature in the conductance. For both orientations of the magnetic field, the transmission probability is still correctly described by pseudospin conservation. Finally, to motivate the large in-plane magnetic field, we show that its energy spectrum can be mimicked by specific lattice deformations such as a relative shift of one of the layers. With this equivalence we introduce the notion of an in-plane pseudomagnetic field.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000372409900006 Publication Date 2016-03-21
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2469-9950;2469-9969; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.836 Times cited (down) 11 Open Access
Notes ; This work was supported by Fonds Wetenschappelijk Onderzoek (FWO-Vl) through an aspirant research grant to M.V.D.D. and B.V.D. ; Approved Most recent IF: 3.836
Call Number UA @ lucian @ c:irua:133197 Serial 4267
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Author Cariglia, M.; Vargas-Paredes, A.; Doria, M.M.; Bianconi, A.; Milošević, M.V.; Perali, A.
Title Shape-Resonant Superconductivity in Nanofilms: from Weak to Strong Coupling Type A1 Journal article
Year 2016 Publication Journal of superconductivity and novel magnetism Abbreviated Journal J Supercond Nov Magn
Volume 29 Issue 29 Pages 3081-3086
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract Ultrathin superconductors of different materials are becoming a powerful platform to find mechanisms for enhancement of superconductivity, exploiting shape resonances in different superconducting properties. Here, we evaluate the superconducting gap and its spatial profile, the multiple gap components, and the chemical potential, of generic superconducting nanofilms, considering the pairing attraction and its energy scale as tunable parameters, from weak to strong coupling, at fixed electron density. Superconducting properties are evaluated at mean field level as a function of the thickness of the nanofilm, in order to characterize the shape resonances in the superconducting gap. We find that the most pronounced shape resonances are generated for weakly coupled superconductors, while approaching the strong coupling regime the shape resonances are rounded by a mixing of the subbands due to the large energy gaps extending over large energy scales. Finally, we find that the spatial profile, transverse to the nanofilm, of the superconducting gap acquires a flat behavior in the shape resonance region, indicating that a robust and uniform multigap superconducting state can arise at resonance.
Address
Corporate Author Thesis
Publisher Place of Publication New York, N.Y. Editor
Language Wos 000390030600016 Publication Date 2016-08-17
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1557-1939 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 1.18 Times cited (down) 11 Open Access
Notes ; We acknowledge D. Valentinis, D. Van der Marel, and C. Berthod for useful discussions. A. Ricci is also acknowledged for his comments on the experimental detection of the predictions of this paper. A. Bianconi acknowledges financial support from Superstripes non-profit organization. M. Cariglia acknowledges CNPq support from project (205029 / 2014-0) and FAPEMIG support from project APQ-02164-14. M.M. Doria acknowledges CNPq support from funding (23079.014992 / 2015-39). M.V. Milosevic acknowledges support from Research Foundation – Flanders (FWO). A. Perali acknowledges financial support from the University of Camerino under the project FAR “Control and enhancement of superconductivity by engineering materials at the nanoscale”. All authors acknowledge the collaboration within the MultiSuper Network (http://www.multisuper.org) for exchange of ideas and suggestions. ; Approved Most recent IF: 1.18
Call Number UA @ lucian @ c:irua:140347 Serial 4461
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Author Trashin, S.; De Jong, M.; Luyckx, E.; Dewilde, S.; De Wael, K.
Title Electrochemical evidence for neuroglobin activity on NO at physiological concentrations Type A1 Journal article
Year 2016 Publication Journal of biological chemistry Abbreviated Journal J Biol Chem
Volume 291 Issue 36 Pages 18959-18966
Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Abstract The true function of neuroglobin (Ngb) and, particularly, human Ngb (NGB) has been under debate since its discovery 15 years ago. It has been expected to play a role in oxygen binding/supply, but a variety of other functions have been put forward, including NO dioxygenase activity. However, in vitro studies that could unravel these potential roles have been hampered by the lack of an Ngb-specific reductase. In this work, we used electrochemical measurements to investigate the role of an intermittent internal disulfide bridge in determining NO oxidation kinetics at physiological NO concentrations. The use of a polarized electrode to efficiently interconvert the ferric (Fe3+) and ferrous (Fe2+) forms of an immobilized NGB showed that the disulfide bridge both defines the kinetics of NO dioxygenase activity and regulates appearance of the free ferrous deoxy-NGB, which is the redox active form of the protein in contrast to oxy-NGB. Our studies further identified a role for the distal histidine, interacting with the hexacoordinated iron atom of the heme, in oxidation kinetics. These findings may be relevant in vivo, for example in blocking apoptosis by reduction of ferric cytochrome c, and gentle tuning of NO concentration in the tissues.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000383242300031 Publication Date 2016-07-12
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0021-9258; 1083-351x ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 4.125 Times cited (down) 11 Open Access
Notes ; This work was supported by Fonds Wetenschappelijk Onderzoek (FWO) Grant G.0687.13 and Universiteit Antwerpen GOA BOF 28312. The authors declare that they have no conflicts of interest with the contents of this article. ; Approved Most recent IF: 4.125
Call Number UA @ admin @ c:irua:134340 Serial 5590
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Author Filez, M.; Redekop, E.A.; Galvita, V.V.; Poelman, H.; Meledina, M.; Turner, S.; Van Tendeloo, G.; Bell, A.T.; Marin, G.B.
Title The role of hydrogen during Pt-Ga nanocatalyst formation Type A1 Journal article
Year 2016 Publication Physical chemistry, chemical physics Abbreviated Journal Phys Chem Chem Phys
Volume 18 Issue 18 Pages 3234-3243
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Hydrogen plays an essential role during the in situ assembly of tailored catalytic materials, and serves as key ingredient in multifarious chemical reactions promoted by these catalysts. Despite intensive debate for several decades, the existence and nature of hydrogen-involved mechanisms – such as hydrogen-spillover, surface migration – have not been unambiguously proven and elucidated up to date. Here, Pt-Ga alloy formation is used as a probe reaction to study the behavior and atomic transport of H and Ga, starting from Pt nanoparticles on hydrotalcite-derived Mg(Ga)(Al)Ox supports. In situ XANES spectroscopy, time-resolved TAP kinetic experiments, HAADF-STEM imaging and EDX mapping are combined to probe Pt, Ga and H in a series of H2 reduction experiments up to 650 degrees C. Mg(Ga)(Al)Ox by itself dissociates hydrogen, but these dissociated hydrogen species do not induce significant reduction of Ga3+ cations in the support. Only in the presence of Pt, partial reduction of Ga3+ into Gadelta+ is observed, suggesting that different reaction mechanisms dominate for Pt- and Mg(Ga)(Al)Ox-dissociated hydrogen species. This partial reduction of Ga3+ is made possible by Pt-dissociated H species which spillover onto non-reducible Mg(Al)Ox or partially reducible Mg(Ga)(Al)Ox and undergo long-range transport over the support surface. Moderately mobile Gadelta+Ox migrates towards Pt clusters, where Gadelta+ is only fully reduced to Ga0 on condition of immediate stabilization inside Pt-Ga alloyed nanoparticles.
Address Laboratory for Chemical Technology (LCT), Ghent University, Technologiepark 914, B-9052 Ghent, Belgium. hilde.poelman@ugent.be
Corporate Author Thesis
Publisher Place of Publication Editor
Language English Wos 000369506000106 Publication Date 2016-01-04
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1463-9076 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 4.123 Times cited (down) 10 Open Access
Notes This work was supported by the Fund for Scientific Research Flanders (FWO: G.0209.11), the ‘Long Term Structural Methusalem Funding by the Flemish Government’, the IAP 7/05 Interuniversity Attraction Poles Programme – Belgian State – Belgian Science Policy, and the Fund for Scientific Research Flanders (FWO-Vlaanderen) in supplying financing of beam time at the DUBBLE beam line of the ESRF and travel costs and a postdoctoral fellowship for S.T. The authors acknowledge the assistance from D. Banerjee (XAS campaign 26-01-979) at DUBBLE. E. A. Redekop acknowledges the Marie Curie International Incoming Fellowship granted by the European Commission (Grant Agreement No. 301703). The authors also express their gratitude to V. Bliznuk for acquisition of the TEM images. Approved Most recent IF: 4.123
Call Number c:irua:132315 Serial 4000
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Author Altantzis, T.; Yang, Z.; Bals, S.; Van Tendeloo, G.; Pileni, M.-P.
Title Thermal Stability of CoAu13Binary Nanoparticle Superlattices under the Electron Beam Type A1 Journal article
Year 2016 Publication Chemistry of materials Abbreviated Journal Chem Mater
Volume 28 Issue 28 Pages 716-719
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract One primary goal of self-assembly in nanoscale regime is to implement multifunctional binary nanoparticle superlattices into practical use. In the last decade, considerable effort has been put into the fabrication of binary nanoparticle superlattices with controllable structure and stoichiometry. However, limited effort has been made in order to improve the stability of these binary nanoparticle superlattices, which is a prerequisite for their potential application. In this work, we demonstrate that the carbon deposition from specimen contamination can play an auxiliary role during the heat treatment of binary nanoparticle superlattices. With the in-situ carbon matrix formation, the thermal stability of CoAu 13 binary nanoparticle superlattices is unambiguously enhanced.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000370112200007 Publication Date 2016-01-20
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0897-4756 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 9.466 Times cited (down) 10 Open Access OpenAccess
Notes The research leading to these results has been supported by an Advanced Grant of the European Research Council under Grant 267129. The authors appreciate financial support by theEuropean Union under the Framework 7 program under a contract for an Integrated Infrastructure Initiative (Reference No. 262348 ESMI). S.B. acknowledges funding from ERC Starting Grant COLOURATOMS (335078).; ECAS_Sara; (ROMEO:white; preprint:; postprint:restricted 12 months embargo; pdfversion:cannot); Approved Most recent IF: 9.466
Call Number c:irua:131908 Serial 4040
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Author Govaerts, K.; Partoens, B.; Lamoen, D.
Title Extended homologous series of Sn–O layered systems: A first-principles study Type A1 Journal article
Year 2016 Publication Solid state communications Abbreviated Journal Solid State Commun
Volume 243 Issue 243 Pages 36-43
Keywords A1 Journal article; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT)
Abstract Apart from the most studied tin-oxide compounds, SnO and SnO2, intermediate states have been claimed to exist for more than a hundred years. In addition to the known homologous series (Seko et al., Phys. Rev. Lett. 100, 045702 (2008)), we here predict the existence of several new compounds with an O concentration between 50 % (SnO) and 67 % (SnO2). All these intermediate compounds are constructed from removing one or more (101) oxygen layers of SnO2. Since the van der Waals (vdW) interaction is known to be important for the Sn-Sn interlayer distances, we use a vdW-corrected functional, and compare these results with results obtained with PBE and hybrid functionals. We present the electronic properties of the intermediate structures and we observe a decrease of the band gap when (i) the O concentration increases and (ii) more SnO-like units are present for a given concentration. The contribution of the different atoms to the valence and conduction band is also investigated.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000381544200007 Publication Date 2016-06-12
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0038-1098 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 1.554 Times cited (down) 10 Open Access
Notes We gratefully acknowledge financial support from a GOA fund of the University of Antwerp. K.G. thanks the University of Antwerp for a PhD fellowship. The computational resources and services used in this work were provided by the VSC (Flemish Supercomputer Center) and the HPC infrastructure of the University of Antwerp (CalcUA), both funded by the Hercules Foundation and the Flemish Government – department EWI. Approved Most recent IF: 1.554
Call Number c:irua:134037 Serial 4085
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Author Karakulina, O.M.; Khasanova, N.R.; Drozhzhin, O.A.; Tsirlin, A.A.; Hadermann, J.; Antipov, E.V.; Abakumov, A.M.
Title Antisite Disorder and Bond Valence Compensation in Li2FePO4F Cathode for Li-Ion Batteries Type A1 Journal article
Year 2016 Publication Chemistry Of Materials Abbreviated Journal Chem Mater
Volume 28 Issue 28 Pages 7578-7581
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000387518500004 Publication Date 2016-11-08
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0897-4756 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 9.466 Times cited (down) 10 Open Access
Notes Russian Science Foundation, 16-19-00190 ; Fonds Wetenschappelijk Onderzoek, G040116N ; Approved Most recent IF: 9.466
Call Number EMAT @ emat @ c:irua:139170 c:irua:138599 Serial 4320
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Author Van der Donck, M.; De Beule, C.; Partoens, B.; Peeters, F.M.; Van Duppen, B.
Title Piezoelectricity in asymmetrically strained bilayer graphene Type A1 Journal article
Year 2016 Publication 2D materials Abbreviated Journal 2D Mater
Volume 3 Issue 3 Pages 035015
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract We study the electronic properties of commensurate faulted bilayer graphene by diagonalizing the one-particle Hamiltonian of the bilayer system in a complete basis of Bloch states of the individual graphene layers. Our novel approach is very general and can be easily extended to any commensurate graphene-based heterostructure. Here, we consider three cases: (i) twisted bilayer graphene, (ii) bilayer graphene where triaxial stress is applied to one layer and (iii) bilayer graphene where uniaxial stress is applied to one layer. We show that the resulting superstructures can be divided into distinct classes, depending on the twist angle or the magnitude of the induced strain. The different classes are distinguished from each other by the interlayer coupling mechanism, resulting in fundamentally different low-energy physics. For the cases of triaxial and uniaxial stress, the individual graphene layers tend to decouple and we find significant charge transfer between the layers. In addition, this piezoelectric effect can be tuned by applying a perpendicular electric field. Finally, we show how our approach can be generalized to multilayer systems.
Address
Corporate Author Thesis
Publisher IOP Publishing Place of Publication Bristol Editor
Language Wos 000384072500003 Publication Date 2016-08-31
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2053-1583 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 6.937 Times cited (down) 10 Open Access
Notes ; This work was supported by the Research Foundation-Flanders (FWO-Vl) through aspirant research grants to MVDD, CDB, and BVD. ; Approved Most recent IF: 6.937
Call Number UA @ lucian @ c:irua:137203 Serial 4361
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Author Juchtmans, R.; Clark, L.; Lubk, A.; Verbeeck, J.
Title Spiral phase plate contrast in optical and electron microscopy Type A1 Journal article
Year 2016 Publication Physical review A Abbreviated Journal Phys Rev A
Volume 94 Issue 94 Pages 023838
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract The use of phase plates in the back focal plane of a microscope is a well-established technique in optical microscopy to increase the contrast of weakly interacting samples and is gaining interest in electron microscopy as well. In this paper we study the spiral phase plate (SPP), also called helical, vortex, or two-dimensional Hilbert phase plate, which adds an angularly dependent phase of the form exp(iℓϕk) to the exit wave in Fourier space. In the limit of large collection angles, we analytically calculate that the average of a pair of l=+-1

SPP filtered images is directly proportional to the gradient squared of the exit wave, explaining the edge contrast previously seen in optical SPP work. We discuss the difference between a clockwise-anticlockwise pair of SPP filtered images and derive conditions under which the modulus of the wave's gradient can be seen directly from one SPP filtered image. This work provides the theoretical background to interpret images obtained with a SPP, thereby opening new perspectives for new experiments to study, for example, magnetic materials in an electron microscope.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000381882800011 Publication Date 2016-08-22
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2469-9926 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.925 Times cited (down) 10 Open Access
Notes The authors acknowledge support from the FWO (Aspirant Fonds Wetenschappelijk Onderzoek – Vlaanderen) and the EU under the Seventh Framework Program (FP7) under a contract for an Integrated Infrastructure Initiative, Reference No. 312483-ESTEEM2 and ERC Starting Grant No. 278510 VORTEX.; ECASJO_ Approved Most recent IF: 2.925
Call Number EMAT @ emat @ c:irua:140086 Serial 4418
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Author Berdiyorov, G.R.; Mortazavi, B.; Ahzi, S.; Peeters, F.M.; Khraisheh, M.K.
Title Effect of straining graphene on nanopore creation using Si cluster bombardment: A reactive atomistic investigation Type A1 Journal article
Year 2016 Publication Journal of applied physics Abbreviated Journal J Appl Phys
Volume 120 Issue 120 Pages 225108
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract Graphene nanosheets have recently received a revival of interest as a new class of ultrathin, high-flux, and energy-efficient sieving membranes because of their unique two-dimensional and atomically thin structure, good flexibility, and outstanding mechanical properties. However, for practical applications of graphene for advanced water purification and desalination technologies, the creation of well controlled, high-density, and subnanometer diameter pores becomes a key factor. Here, we conduct reactive force-field molecular dynamics simulations to study the effect of external strain on nanopore creation in the suspended graphene by bombardment with Si clusters. Depending on the size and energy of the clusters, different kinds of topography were observed in the graphene sheet. In all the considered conditions, tensile strain results in the creation of nanopores with regular shape and smooth edges. On the contrary, compressive strain increases the elastic response of graphene to irradiation that leads to the formation of net-like defective structures with predominantly carbon atom chains. Our findings show the possibility of creating controlled nanopores in strained graphene by bombardment with Si clusters. Published by AIP Publishing.
Address
Corporate Author Thesis
Publisher American Institute of Physics Place of Publication New York, N.Y. Editor
Language Wos 000391535900022 Publication Date 2016-12-15
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 (down) 10 Open Access
Notes ; ; Approved Most recent IF: 2.068
Call Number UA @ lucian @ c:irua:141451 Serial 4554
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Author Keulemans, M.; Verbruggen, S.W.; Hauchecorne, B.; Martens, J.A.; Lenaerts, S.
Title Activity versus selectivity in photocatalysis : morphological or electronic properties tipping the scale Type A1 Journal article
Year 2016 Publication Journal of catalysis Abbreviated Journal J Catal
Volume 344 Issue Pages 221-228
Keywords A1 Journal article; Sustainable Energy, Air and Water Technology (DuEL)
Abstract In this paper a structure-activity and structure-selectivity relation is established for three commercial TiO2 sources (P25, P90, and PC500). Morphological and electronic parameters of the photocatalysts are determined using widely applicable and inexpensive characterization procedures. More specifically, the electronic properties are rigorously characterized using an electron titration method yielding quantitative information on the amount of defect sites present in the catalyst. Surface photovoltage measurements on the other hand provide complementary information on the charge carrier recombination process. As model reaction, the degradation of a solid layer of stearic acid is studied using an in situ FTIR reaction cell that enables to investigate the catalyst surface and possible formation of reaction intermediates while the reactions are ongoing. We show that the order of photocatalytic conversion is PC500 > P90 > P25, matching the order of favorable morphological properties. In terms of selectivity to CO2 formation (complete mineralization), however, this trend is reversed: P25 > P90 > PC500, now matching the order of advantageous electronic properties, i.e. low charge carrier recombination and high charge carrier generation. With this we intend to provide new mechanistic insights using a wide variety of physical, (wet) chemical and operando analysis methods that aid the development of performant (self-cleaning) photocatalytic materials.
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000390182800022 Publication Date 2016-10-15
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0021-9517 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 6.844 Times cited (down) 10 Open Access
Notes ; M.K. acknowledges Flemish Agency for Innovation & Entrepreneurship for the doctoral scholarship. S.W.V. acknowledges the Fonds Wetenschappelijk Onderzoek (FWO) for a post-doctoral fellowship. J.A.M. acknowledges the Flemish government for long-term structural funding (Methusalem). ; Approved Most recent IF: 6.844
Call Number UA @ admin @ c:irua:136339 Serial 5926
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Author van Walsem, J.; Verbruggen, S.W.; Modde, B.; Lenaerts, S.; Denys, S.
Title CFD investigation of a multi-tube photocatalytic reactor in non-steady-state conditions Type A1 Journal article
Year 2016 Publication Chemical engineering journal Abbreviated Journal Chem Eng J
Volume 304 Issue Pages 808-816
Keywords A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL)
Abstract A novel multi-tube photoreactor is presented with a high efficiency (over 90% conversion) toward the degradation of acetaldehyde in air under UV conditions with an incident intensity of 2.1 mW cm−2. A CFD model was developed to simulate the transient adsorption and photocatalytic degradation processes of acetaldehyde in this reactor design and to estimate the corresponding kinetic parameters through an optimization routine using the experimentally determined outlet concentration profiles. The CFD model takes into account the entire reactor geometry and all relevant flow parameters, in contrast to analytical methods that often oversimplify the physical and chemical process characteristics. Using CFD, we show that both adsorption and desorption rate constants increase by respectively one and two orders of magnitude when the UV light is switched on, which clearly affects the transient behavior. The agreement of the experimental and modelled concentration profiles is excellent as evidenced by a coefficient of determination of at least 0.965. To demonstrate the reliability and accuracy of all parameters obtained from the modelling approach, an ultimate validation test was performed using other conditions than the ones used for estimating the kinetic parameters. The model was able to accurately simulate simultaneous adsorption, desorption and photocatalytic degradation.
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000384777200089 Publication Date 2016-07-08
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1385-8947; 1873-3212 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 6.216 Times cited (down) 10 Open Access
Notes ; J.V.W. acknowledges the Agentschap Innoveren & Ondernemen for a PhD fellowship. S.W.V. acknowledges the Research Foundation – Flanders (FWO) for a postdoctoral fellowship. ; Approved Most recent IF: 6.216
Call Number UA @ admin @ c:irua:139620 Serial 5933
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Author Jeanloz, S.; Lizin, S.; Beenaerts, N.; Brouwer, R.; Van Passel, S.; Witters, N.
Title Towards a more structured selection process for attributes and levels in choice experiments : a study in a Belgian protected area Type A1 Journal article
Year 2016 Publication Ecosystem Services Abbreviated Journal Ecosyst Serv
Volume 18 Issue Pages 45-57
Keywords A1 Journal article; Engineering Management (ENM)
Abstract The process of selecting attributes for inclusion in choice experiments frequently involves qualitative methods such as focus groups and interviews. In order for a choice experiment to be successful and the results to be valid, this qualitative selection process is essential. It often lacks rigour and is poorly described, particularly in environmental choice experiments. We propose a meticulous attribute and attribute-level selection process consisting of a scoring exercise and an interactive discussion. This paper provides a case study describing how attributes and attribute-levels were identified and selected for the National Park Hoge Kempen in Belgium. We carried out four focus groups and thirteen semi-structured interviews with various park stakeholders to select attributes from six categories: the four categories of ecosystem services (supporting, provisioning, regulating, cultural), infrastructure, and land use types. The top-ranked characteristics were nature conservation, natural forests, biodiversity refuge, wetlands, landscape variety, heathlands, air purification, and education. Both the scoring exercise and the interactive discussion contributed to the attributes selected for the CE. Following these, an ultimate expert consultation stage is recommended to approve both the attribute and attribute-level selection. The semi-qualitative protocol proposed in this paper can help practitioners and demonstrates how the results guide choice experiment design.
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000375213800004 Publication Date 2016-02-17
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2212-0416 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 4.072 Times cited (down) 10 Open Access
Notes ; We would like to thank study informants, focus group participants and interviewees, as well as Tom Kuppens, Silvie Daniels, Janka Vanschoenwinkel and Michele Moretti of the Environmental Economics Research group of Hasselt University. Johan Van den Bosch, project leader at Regional Landschap Kempen en Maasland (RLKM), and Rolinde Demeyer from the Research Institute for Nature and Forest (INBO) have provided this study with valuable assistance and comments. Sarah Jeanloz was funded by the INTERREG IVB NEW program (Grant no. D1941/ 56200), Nele Witters (Grant no. 12B2913N) and Sebastien Lizin (Grant no. 12G5415N) are funded by Research Foundation- Flanders (FWD). Finally, we thank all reviewers for their constructive and insightful comments, and for their time. ; Approved Most recent IF: 4.072
Call Number UA @ admin @ c:irua:134332 Serial 6272
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Author Roy, P.; Torun, E.; de Groot, R.A.
Title Effect of doping and elastic properties in (Mn,Fe)2(Si,P) Type A1 Journal article
Year 2016 Publication Physical review B Abbreviated Journal Phys Rev B
Volume 93 Issue 93 Pages 094110
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract Mixed magnetism (the coexistence of strong and weak magnetism in one material) is regarded as the origin of the giant magnetocaloric effect (GMCE). A good example is (Mn,Fe)(2)(Si,P), which is established as one of the best magnetocaloric materials available. Tuning the material properties are essential for optimizing its performance, and a straightforward way to do that is by doping. In this article, an ab initio electronic structure method was used to calculate the structure and magnetic properties of 3d-transition-metal-doped (Mn,Fe)(2)(Si,P) materials for magnetocaloric applications (transition metals are Cr, Co, Mn, Ni, Cu). For a steady performance, the material should be mechanically stable. A detailed analysis of the elastic constants shows that the mechanical stability of the (Mn,Fe)(2)(Si,P) system increases significantly by doping with boron without affecting the magnetic properties. Insights of the influence of doping enable future studies to understand and predict bettermagnetocaloric materials.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000372712100001 Publication Date 2016-03-25
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2469-9950;2469-9969; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.836 Times cited (down) 9 Open Access
Notes ; This work is part of an Industrial Partnership Programme (IPP I28) of Fundamenteel Onderzoek der Materie (FOM) (The Netherlands) and co-financed by BASF New Business. The authors would like to thank Phuong Thao Nguyen and Dr. Gilles A. de Wijs for very useful discussions. ; Approved Most recent IF: 3.836
Call Number UA @ lucian @ c:irua:133192 Serial 4164
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Author Dhayalan, S.K.; Kujala, J.; Slotte, J.; Pourtois, G.; Simoen, E.; Rosseel, E.; Hikavyy, A.; Shimura, Y.; Iacovo, S.; Stesmans, A.; Loo, R.; Vandervorst, W.;
Title On the manifestation of phosphorus-vacancy complexes in epitaxial Si:P films Type A1 Journal article
Year 2016 Publication Applied physics letters Abbreviated Journal Appl Phys Lett
Volume 108 Issue 108 Pages 082106
Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract In situ doped epitaxial Si: P films with P concentrations > 1 x 10(21) at./cm(3) are suitable for source-drain stressors of n-FinFETs. These films combine the advantages of high conductivity derived from the high P doping with the creation of tensile strain in the Si channel. It has been suggested that the tensile strain developed in the Si: P films is due to the presence of local Si3P4 clusters, which however do not contribute to the electrical conductivity. During laser annealing, the Si3P4 clusters are expected to disperse resulting in an increased conductivity while the strain reduces slightly. However, the existence of Si3P4 is not proven. Based on first-principles simulations, we demonstrate that the formation of vacancy centered Si3P4 clusters, in the form of four P atoms bonded to a Si vacancy, is thermodynamically favorable at such high P concentrations. We suggest that during post epi-growth annealing, a fraction of the P atoms from these clusters are activated, while the remaining part goes into interstitial sites, thereby reducing strain. We corroborate our conjecture experimentally using positron annihilation spectroscopy, electron spin resonance, and Rutherford backscattering ion channeling studies. (C) 2016 AIP Publishing LLC.
Address
Corporate Author Thesis
Publisher American Institute of Physics Place of Publication New York, N.Y. Editor
Language Wos 000373057000023 Publication Date 2016-02-24
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 (down) 9 Open Access
Notes Approved Most recent IF: 3.411
Call Number UA @ lucian @ c:irua:133245 Serial 4217
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Author Retuerto, M.; Skiadopoulou, S.; Li, M.R.; Abakumov, A.M.; Croft, M.; Ignatov, A.; Sarkar, T.; Abbett, B.M.; Pokorný, J.; Savinov, M.; Nuzhnyy, D.; Prokleška, J.; Abeykoon, M.; Stephens, P.W.; Hodges, J.P.; Vaněk, P.; Fennie, C.J.; Rabe, K.M.; Kamba, S.; Greenblatt, M.;
Title Pb2MnTeO6 double perovskite : an antipolar anti-ferromagnet Type A1 Journal article
Year 2016 Publication Inorganic chemistry Abbreviated Journal Inorg Chem
Volume 55 Issue 55 Pages 4320-4329
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Pb2MnTeO6, a new double perovskite, was synthesized. Its crystal structure was determined by synchrotron X-ray and powder neutron diffraction. Pb2MnTeO6 is monoclinic (I2/m) at room temperature with a regular arrangement of all the cations in their polyhedra. However, when the temperature is lowered to similar to 120 K it undergoes a phase transition from I2/m to C2/c structure. This transition is accompanied by a displacement of the Pb atoms from the center of their polyhedra due to the 6s2 lone-pair electrons, together with a surprising off-centering of Mn2+ (d5) magnetic cations. This strong first-order phase transition is also evidenced by specific heat, dielectric, Raman, and infrared spectroscopy measurements. The magnetic characterizations indicate an anti-ferromagnetic (AFM) order below TN approximate to 20 K; analysis of powder neutron diffraction data confirms the magnetic structure with propagation vector k = (0 1 0) and collinear AFM spins. The observed jump in dielectric permittivity near similar to 150 K implies possible anti-ferroelectric behavior; however, the absence of switching suggests that Pb2MnTeO6 can only be antipolar. First-principle calculations confirmed that the crystal and magnetic structures determined are locally stable and that anti-ferroelectric switching is unlikely to be observed in Pb2MnTeO6.
Address
Corporate Author Thesis
Publisher Place of Publication Easton, Pa Editor
Language Wos 000375519700027 Publication Date 2016-04-08
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0020-1669 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 4.857 Times cited (down) 9 Open Access
Notes Approved Most recent IF: 4.857
Call Number UA @ lucian @ c:irua:134219 Serial 4258
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Author Aghaei, M.; Lindner, H.; Bogaerts, A.
Title Ion Clouds in the Inductively Coupled Plasma Torch: A Closer Look through Computations Type A1 Journal article
Year 2016 Publication Analytical chemistry Abbreviated Journal Anal Chem
Volume 88 Issue 88 Pages 8005-8018
Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract We have computationally investigated the introduction of copper elemental particles in an inductively coupled plasma torch connected to a sampling cone, including for the first time the ionization of the sample. The sample is inserted as liquid particles, which are followed inside the entire torch, i.e., from the injector inlet up to the ionization and reaching the sampler. The spatial position of the ion clouds inside the torch as well as detailed information on the copper species fluxes at the position of the sampler orifice and the exhausts of the torch are provided. The effect of on- and off-axis injection is studied. We clearly show that the ion clouds of on-axis injected material are located closer to the sampler with less radial diffusion. This guarantees a higher transport efficiency through the sampler cone. Moreover, our model reveals the optimum ranges of applied power and flow rates, which ensure the proper position of ion clouds inside the torch, i.e., close enough to the sampler to increase the fraction that can enter the mass spectrometer and with minimum loss of material toward the exhausts as well as a sufficiently high plasma temperature for efficient ionization.
Address Research Group PLASMANT, Chemistry Department, University of Antwerp , Universiteitsplein 1, 2610 Antwerp, Belgium
Corporate Author Thesis
Publisher Place of Publication Editor
Language English Wos 000381654800020 Publication Date 2016-07-26
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0003-2700 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 6.32 Times cited (down) 9 Open Access
Notes The authors gratefully acknowledge financial support from the Fonds voor Wetenschappelijk Onderzoek (FWO), Grant Number 6713. The computational work was carried out using the Turing HPC infrastructure at the CalcUA core facility of the Universiteit Antwerpen (UA), a division of the Flemish Supercomputer Center VSC, funded by the Hercules Foundation, the Flemish Government (department EWI), and the UA. Approved Most recent IF: 6.32
Call Number PLASMANT @ plasmant @ c:irua:135644 Serial 4293
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Author Schalm, O.; Crabbé, A.; Storme, P.; Wiesinger, R.; Gambirasi, A.; Grieten, E.; Tack, P.; Bauters, S.; Kleber, C.; Favaro, M.; Schryvers, D.; Vincze, L.; Terryn, H.; Patelli, A.
Title The corrosion process of sterling silver exposed to a Na2S solution: monitoring and characterizing the complex surface evolution using a multi-analytical approach Type A1 Journal article
Year 2016 Publication Applied Physics A-Materials Science & Processing Abbreviated Journal Appl Phys A-Mater
Volume 122 Issue 122 Pages 903
Keywords A1 Journal article; Electron Microscopy for Materials Science (EMAT);
Abstract Many historical ‘silver’ objects are composed of sterling silver, a silver alloy containing small amounts of copper. Besides the dramatic impact of copper on the corrosion process, the chemical composition of the corrosion layer evolves continuously. The evolution of the surface during the exposure to a Na2S solution was monitored by means of visual observation at macroscopic level, chemical analysis at microscopic level and analysis at the nanoscopic level. The corrosion process starts with the preferential oxidation of copper, forming mixtures of oxides and sulphides while voids are being created beneath the corrosion layer. Only at a later stage, the silver below the corrosion layer is consumed. This results in the formation of jalpaite and at a later stage of acanthite. The acanthite is found inside the corrosion layer at the boundaries of jalpaite grains and as individual grains between the jalpaite grains but also as a thin film on top of the corrosion layer. The corrosion process could be described as a sequence of 5 subsequent surface states with transitions between these states.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000384753800033 Publication Date 2016-09-20
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0947-8396 ISBN Additional Links
Impact Factor 1.455 Times cited (down) 9 Open Access
Notes The authors are grateful for the financial support by the EU-FP7 Grant PANNA No. 282998 and for the opportunity to perform SR-XPS measurements at the NanoESCA beamline of the Elettra storage ring, under the approval of the advisory Committee (Proposal No. 20135164), as well as the opportunity to perform XANES measurements at the DUBBLE beamline of the ESRF storage ring (Proposal No. 26-01-990). The authors are grateful for the financial support by the STIMPRO Project FFB150215 of the University of Antwerp. Pieter Tack is funded by a Ph.D. Grant of the Agency for Innovation by Science and Technology (IWT). We would also like to thank Peter Van den Haute for the XRD measurements that were performed at the University of Ghent. Approved Most recent IF: 1.455
Call Number EMAT @ emat @ Serial 4331
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Author Li, K.; Idrissi, H.; Sha, G.; Song, M.; Lu, J.; Shi, H.; Wang, W.; Ringer, S.P.; Du, Y.; Schryvers, D.
Title Quantitative measurement for the microstructural parameters of nano-precipitates in Al-Mg-Si-Cu alloys Type A1 Journal article
Year 2016 Publication Materials characterization Abbreviated Journal Mater Charact
Volume 118 Issue 118 Pages 352-362
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract Size, number density and volume fraction of nano-precipitates are important microstructural parameters controlling the strengthening of materials. In this work a widely accessible, convenient, moderately time efficient method with acceptable accuracy and precision has been provided for measurement of volume fraction of nano-precipitates in crystalline materials. The method is based on the traditional but highly accurate technique of measuring foil thickness via convergent beam electron diffraction. A new equation is proposed and verified with the aid of 3-dimensional atom probe (3DAP) analysis, to compensate for the additional error resulted from the hardly distinguishable contrast of too short incomplete precipitates cut by the foil surface. The method can be performed on a regular foil specimen with a modem LaB6 or field-emission-gun transmission electron microscope. Precisions around +/- 16% have been obtained for precipitate volume fractions of needle-like beta ''/C and Q precipitates in an aged Al-Mg-Si-Cu alloy. The measured number density is dose to that directly obtained using 3DAP analysis by a misfit of 45%, and the estimated precision for number density measurement is about +/- 11%. The limitations of the method are also discussed.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000383292000042 Publication Date 2016-06-07
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 (down) 9 Open Access
Notes This work is financially supported by National Natural Science Foundation of China (51501230 and 51531009) and Postdoctoral Science Foundation of Central South University (502042057). H.I. acknowledges the IAP program of the Belgian State Federal Office for Scientific, Technical and Cultural Affairs under Contract No. P7/21 and FWO project G.0576.09N. Approved Most recent IF: 2.714
Call Number EMAT @ emat @ c:irua:137171 Serial 4334
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Author Mirzakhani, M.; Zarenia, M.; da Costa, D.R.; Ketabi, S.A.; Peeters, F.M.
Title Energy levels of ABC-stacked trilayer graphene quantum dots with infinite-mass boundary conditions Type A1 Journal article
Year 2016 Publication Physical review B Abbreviated Journal Phys Rev B
Volume 94 Issue 94 Pages 165423
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract Using the continuum model, we investigate the confined states and the corresponding wave functions of ABC-stacked trilayer graphene (TLG) quantum dots (QDs). First, a general infinite-mass boundary condition is derived and applied to calculate the electron and hole energy levels of a circular QD in both the absence and presence of a perpendicular magnetic field. Our analytical results for the energy spectra agree with those obtained by using the tight-binding model, where a TLG QD is surrounded by a staggered potential. Our findings show that (i) the energy spectrum exhibits intervalley symmetry E-K(e)(m) = -E-K'(h)(m) for the electron (e) and hole (h) states, where m is the angular momentum quantum number, (ii) the zero-energy Landau level (LL) is formed by the magnetic states with m <= 0 for both Dirac valleys, that is different from monolayer and bilayer graphene QD with infinite-mass potential in which only one of the cones contributes, and (iii) groups of three quantum Hall edge states in the tight-binding magnetic spectrum approach the zero LL, which results from the layer symmetry in TLG QDs.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000386168000011 Publication Date 2016-10-19
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2469-9950;2469-9969; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.836 Times cited (down) 9 Open Access
Notes ; This work was supported by the Flemish Science Foundation (FWO-Vl), the Brazilian Council for Research (CNPq), the Science without Borders program, PRONEX/FUNCAP, and CAPES foundation. ; Approved Most recent IF: 3.836
Call Number UA @ lucian @ c:irua:138174 Serial 4353
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Author Thirumalraj, alamurugan; Palanisamy, S.; Chen, S.-M.; De Wael, K.
Title A graphene/gelatin composite material for the entrapment of hemoglobin for bioelectrochemical sensing applications Type A1 Journal article
Year 2016 Publication Journal of the electrochemical society Abbreviated Journal J Electrochem Soc
Volume 163 Issue 7 Pages 265-271
Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Abstract In the present work, a novel graphene (GN) and gelatin (GTN) composite was prepared and used as an immobilization matrix for hemoglobin (Hb). Compared with Hb immobilized on a bare, GN or GTN modified glassy carbon electrode (GCE), a stable and pair of well-defined quasi redox couple was observed at an Hb modified GN/GTN composite GCE at a formal potential of −0.306 V versus Ag|AgCl. The direct electrochemical behavior of Hb was greatly enhanced by the presence of both GTN and GN. A heterogeneous electron transfer rate constant (Ks) was calculated as 3.82 s−1 for Hb immobilized at GN/GTN modified GCE, which indicates the fast direct electron transfer of Hb toward the electrode surface. The biosensor shows a stable and wide linear response for H2O2 in the linear response range from 0.1 μM to 786.6 μM with an analytical sensitivity and limit of detection of 0.48 μAμM−1 cm−2 and 0.04 μM, respectively. The fabricated biosensor holds its high selectivity in the presence of potentially active interfering species and metal ions. The biosensor shows its satisfactory practical ability in the commercial contact lens solution and human serum samples.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000377412900047 Publication Date 2016-04-08
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0013-4651 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.259 Times cited (down) 9 Open Access
Notes ; This project was supported by the Ministry of Science and Technology (project no. NSC1012113M027001MY3), Taiwan (Republic of China). The authors express their sincere thanks to Prof. Bih-Show Lou, Chemistry Division, Center for General Education, Chang Gung University, Tao-Yuan, Taiwan for providing the human serum samples. ; Approved Most recent IF: 3.259
Call Number UA @ admin @ c:irua:132627 Serial 5635
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Author Hamidi-Asl, E.; Dardenne, F.; Pilehvar, S.; Blust, R.; De Wael, K.
Title Unique properties of core shell Ag@Au nanoparticles for the aptasensing of bacterial cells Type A1 Journal article
Year 2016 Publication Chemosensors Abbreviated Journal
Volume 4 Issue 3 Pages 16
Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Abstract In this article, it is shown that the efficiency of an electrochemical aptasensing device is influenced by the use of different nanoparticles (NPs) such as gold nanoparticles (Au), silver nanoparticles (Ag), hollow gold nanospheres (HGN), hollow silver nanospheres (HSN), silvergold core shell (Ag@Au), goldsilver core shell (Au@Ag), and silvergold alloy nanoparticles (Ag/Au). Among these nanomaterials, Ag@Au core shell NPs are advantageous for aptasensing applications because the core improves the physical properties and the shell provides chemical stability and biocompatibility for the immobilization of aptamers. Self-assembly of the NPs on a cysteamine film at the surface of a carbon paste electrode is followed by the immobilization of thiolated aptamers at these nanoframes. The nanostructured (Ag@Au) aptadevice for Escherichia coli as a target shows four times better performance in comparison to the response obtained at an aptamer modified planar gold electrode. A comparison with other (core shell) NPs is performed by cyclic voltammetry and differential pulse voltammetry. Also, the selectivity of the aptasensor is investigated using other kinds of bacteria. The synthesized NPs and the morphology of the modified electrode are characterized by UV-Vis absorption spectroscopy, scanning electron microscopy, energy dispersive X-ray analysis, and electrochemical impedance spectroscopy.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000382480000006 Publication Date 2016-08-29
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2227-9040 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor Times cited (down) 9 Open Access
Notes ; Ezat Hamidi-Asl was financially supported by Belspo (University of Antwerp). The authors are thankful to Femke De Croock for her technical support and to Stanislav Trashin for his worthwhile comments on the manuscript. ; Approved Most recent IF: NA
Call Number UA @ admin @ c:irua:135411 Serial 5886
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Author Ayalew, E.; Janssens, K.; De Wael, K.
Title Unraveling the reactivity of minium towards bicarbonate and the role of lead oxides therein Type A1 Journal article
Year 2016 Publication Analytical chemistry Abbreviated Journal Anal Chem
Volume 88 Issue 3 Pages 1564-1569
Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Abstract Understanding the reactivity of (semiconductor) pigments provides vital information on how to improve conservation strategies for works of art in order to avoid rapid degradation of the pigments. This study focuses on the photoactivity of minium (Pb3O4), a semiconductor pigment, that gives rise to strong discoloration phenomena upon exposure to various environmental conditions. To demonstrate its photoactivity, an electrochemical setup with minium-modified graphite electrode (C|Pb3O4) was used. It is confirmed that minium is a p-type semiconductor which is photoactive during illumination and becomes inactive in the dark. Raman measurements confirm the formation of the degradation products. The photoactivity of a semiconductor pigment is partly defined by the presence of lead oxide (PbO) impurities; these introduce new states in the original band gap. It will be experi-mentally evidenced that the presence of PbO particles in minium leads to an upward shift of the valence band that reduces the band gap. Thus, upon photoexcitation, the electron/hole separation is more easily initialized. The PbO/Pb3O4 composite electrodes demonstrate a higher reductive photocurrent compared to the photocurrent registered at pure PbO or Pb3O4 modified electrodes. Upon exposure to light with energy close to and above the band gap, electrons are excited from the valence band to the conduction band to initialize the reduction of Pb(IV) to Pb(II), resulting in the initial formation of PbO. However in the presence of bicarbonate ions, a significantly higher photoreduction current is recorded since the PbO reacts further to form hydrocerussite. Therefore the presence of bicarbonates in the environment stimulates the photodecomposition process of minium and plays an important role in the degradation process.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000369471100014 Publication Date 2015-12-31
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0003-2700; 5206-882x ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 6.32 Times cited (down) 9 Open Access
Notes ; The authors acknowledge Sanne Aerts from the Laboratory of Adsorption and Catalysis (LADCA) of the University of Antwerp for her help with the UV-vis-DR. Financial support from the SOLARPAINT BOF-GOA project (University of Antwerp Research Council) is acknowledged. The authors are also indebted to F. Vanmeert for performing the XRD measurements. ; Approved Most recent IF: 6.32
Call Number UA @ admin @ c:irua:129963 Serial 5888
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Author Yuan, R.; Claes, N.; Verheyen, E.; Tuel, A.; Bals, S.; Breynaert, E.; Martens, J.; Kirschhock, C.E.A.
Title Synthesis of IWW-type germanosilicate zeolite using 5-azonia-spiro[4, 4]nonane as structure directing agent Type A1 Journal article
Year 2016 Publication New journal of chemistry Abbreviated Journal New J Chem
Volume 40 Issue 40 Pages 4319-4324
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract IWW-type zeolite with Si/Ge of 4.9 is obtained using 5-azonia-spiro[4,4]nonane as template in fluoride-free medium under hydrothermal conditions at 175 °C. In an otherwise identical synthesis, using the related 5-azonia-spiro[4,5]decane as structure directing agent, a mixture of IWW and NON zeolite types was formed. In absence of GeO2 from the reactant mixture, pure NON formed. The IWW zeolite was characterized by XRD, SEM, and HRTEM. IWW zeolite displayed a unique morphology and could be calcined at 600 °C without loss of crystallinity. The Si/Ge ratio of the IWW zeolite was increased by postsynthesis modification. Part of the germanium could be eliminated from the as-synthesized IWW zeolite by acid leaching using 6 M HCl solution. Also the calcined material could be degermanated. Here the presence of a silicon source in the acidic leaching solution minimized structural damage. This way the Si/Ge ratio of the IWW zeolite was increased from 4.9 up to 10.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000375586400038 Publication Date 2016-02-19
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1144-0546 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.269 Times cited (down) 8 Open Access OpenAccess
Notes The authors acknowledge FWO/NWO and ESRF for providing beam time at the DUBBLE and SNBL beamlines (ESRF, Grenoble) and P. Abdala for her assistance during the use of the beamline. The authors are grateful to L. Van Tendeloo for taking SEM images. I. Cuppens and K. Houthoofd are thanked for the ICP and AAS measurements. R.Y. acknowledges Chinese Scholarship Council for a CSC doctoral fellowship. JAM and CEAK acknowledge the Flemish government for long-term structural funding (Methusalem). N.C. and S.B. acknowledge financial support from European Research Council (ERC Starting Grant #335078-COLOURATOMS).; ECAS_Sara; (ROMEO:yellow; preprint:; postprint:restricted ; pdfversion:cannot); Approved Most recent IF: 3.269
Call Number c:irua:133671 Serial 4027
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Author Saqlain, M.A.; Hussain, A.; Siddiq, D.M.; Leenaerts, O.; Leitão, A.A.
Title DFT Study of Synergistic Catalysis of the Water-Gas-Shift Reaction on Cu-Au Bimetallic Surfaces Type A1 Journal article
Year 2016 Publication ChemCatChem Abbreviated Journal Chemcatchem
Volume 8 Issue 8 Pages 1208-1217
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract The water-gas-shift reaction (WGSR) is an important industrial process that can be significantly enhanced at suitable catalyst surfaces. In this work, we investigate the catalytic behavior of metallic Cu(1 0 0) and bimetallic Cu–Au(1 0 0) surfaces. With density functional theory calculations, the variation in the Gibbs free energy (ΔG°), the activation barriers, and the rate constants for the WGSR are calculated. The variation in ΔG° for water dissociation shows that the process is spontaneous up to 520 K on the bimetallic surface and up to 229 K on the Cu(1 0 0) surface. The calculated rate constants for the process also show that the bimetallic surface is much more reactive than the Cu(1 0 0) surface. The calculated pressure–temperature phase diagram for water dissociation shows that the partial pressure of H2O required for water dissociation on the bimetallic surface is substantially lower than that on the Cu(1 0 0) surface at all the studied temperatures. Additionally, the calculations demonstrate that the kinetics of the water-gas-shift reaction is dominated by redox processes on both the surfaces.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000373074900026 Publication Date 2016-02-26
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1867-3880 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 4.803 Times cited (down) 8 Open Access
Notes ; The authors would like to thank the Brazilian agencies CNPq, CAPES, FAPEMIG (CEX-PPM-00262/13), and TWAS for financial support and CENAPAD-SP for computational facilities. M.A. Saqlain pays special thanks to all the members of GFQSI for making his stay in Brazil memorable. ; Approved Most recent IF: 4.803
Call Number c:irua:133236 Serial 4070
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Author Ekimov, E.A.; Kudryavtsev, O.S.; Turner, S.; Korneychuk, S.; Sirotinkin, V.P.; Dolenko, T.A.; Vervald, A.M.; Vlasov, I.I.
Title The effect of molecular structure of organic compound on the direct high-pressure synthesis of boron-doped nanodiamond: Effect of organic compound on synthesis of boron-doped nanodiamond Type A1 Journal article
Year 2016 Publication Physica status solidi : A : applications and materials science Abbreviated Journal Phys Status Solidi A
Volume 213 Issue 213 Pages 2582-2589
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Evolution of crystalline phases with temperature has been studied in materials produced by high-pressure high-temperature treatment of 9-borabicyclo[3.3.1]nonane dimer (9BBN), triphenylborane and trimesitylborane. The boron-doped diamond nanoparticles with a size below 10 nm were obtained at 8–9 GPa and temperatures 970–1250 °C from 9BBN only. Bridged structure and the presence of boron atom in the carbon cycle of 9BBN were revealed to be a key point for the direct synthesis of doped diamond nanocrystals. The diffusional transformation of the disordered carbon phase is suggested to be the main mechanism of the nanodiamond formation from 9BBN in the temperature range of 970–1400 °C. Aqueous suspensions of primary boron-doped diamond nanocrystals were prepared upon removal of non-diamond phases that opens wide opportunities for application of this new nanomaterial in electronics and biotechnologies.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000388321500006 Publication Date 2016-07-04
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1862-6300 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 1.775 Times cited (down) 8 Open Access
Notes Approved Most recent IF: 1.775
Call Number EMAT @ emat @ c:irua:135175 Serial 4120
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Author Andrikopoulos, D.; Sorée, B.; De Boeck, J.
Title Skyrmion-induced bound states on the surface of three-dimensional topological insulators Type A1 Journal article
Year 2016 Publication Journal of applied physics Abbreviated Journal J Appl Phys
Volume 119 Issue 119 Pages 193903
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract The interaction between the surface of a 3D topological insulator and a skyrmion/anti-skyrmion structure is studied in order to investigate the possibility of electron confinement due to the skyrmion presence. Both hedgehog (Neel) and vortex (Bloch) skyrmions are considered. For the hedgehog skyrmion, the in-plane components cannot be disregarded and their interaction with the surface state of the topological insulator (TI) has to be taken into account. A semi-classical description of the skyrmion chiral angle is obtained using the variational principle. It is shown that both the hedgehog and the vortex skyrmion can induce bound states on the surface of the TI. However, the number and the properties of these states depend strongly on the skyrmion type and the skyrmion topological number N-Sk. The probability densities of the bound electrons are also derived where it is shown that they are localized within the skyrmion region. Published by AIP Publishing.
Address
Corporate Author Thesis
Publisher American Institute of Physics Place of Publication New York, N.Y. Editor
Language Wos 000377718100013 Publication Date 2016-05-18
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 (down) 8 Open Access
Notes ; ; Approved Most recent IF: 2.068
Call Number UA @ lucian @ c:irua:134607 Serial 4244
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Author van den Bos, K.H.W.; Krause, F.F.; Béché, A.; Verbeeck, J.; Rosenauer, A.; Van Aert, S.
Title Locating light and heavy atomic column positions with picometer precision using ISTEM Type A1 Journal article
Year 2016 Publication Ultramicroscopy Abbreviated Journal Ultramicroscopy
Volume 172 Issue 172 Pages 75-81
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Recently, imaging scanning transmission electron microscopy (ISTEM) has been proposed as a promising new technique combining the advantages of conventional TEM (CTEM) and STEM [1]. The ability to visualize light and heavy elements together makes it a particularly interesting new, spatially incoherent imaging mode. Here, we evaluate this technique in term of precision with which atomic column locations can be measured. By using statistical parameter estimation theory, we will show that these locations can be accurately measured with a precision in the picometer range. Furthermore, a quantitative comparison is made with HAADF STEM imaging to investigate the advantages of ISTEM.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000390600200009 Publication Date 2016-10-09
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0304-3991 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.843 Times cited (down) 8 Open Access
Notes The authors acknowledge financial support from the Research Foundation Flanders (FWO, Belgium) through project fundings (G.0374.13N, G.0368.15N, G.0369.15N), and by a Ph.D. grant to K.H.W. van den Bos. The research leading to these results has received funding from the Deutsche Forschungsgemeinschaft under Contract No. RO 2057/4-2 and the European Union Seventh Framework Programme under Grant Agreement 312483 – ESTEEM2. We thank Prof. G. Koster from the University of Twente for kindly providing us with the PbTiO3 test sample. Approved Most recent IF: 2.843
Call Number EMAT @ emat @ c:irua:136109UA @ admin @ c:irua:136109 Serial 4288
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Author Hoang, D.-Q.; Pobedinskas, P.; Nicley, S.S.; Turner, S.; Janssens, S.D.; Van Bael, M.K.; D'Haen, J.; Haenen, K.
Title Elucidation of the Growth Mechanism of Sputtered 2D Hexagonal Boron Nitride Nanowalls Type A1 Journal article
Year 2016 Publication Crystal growth & design Abbreviated Journal Cryst Growth Des
Volume 16 Issue 7 Pages 3699-3708
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Hexagonal boron nitride nanowall thin films were deposited on Si(100) substrates using a Ar(51%)/N-2(44%)/H-2(5%) gas mixture by unbalanced radio frequency sputtering. The effects of various target-to-substrate distances, substrate temperatures, and substrate tilting angles were investigated. When the substrate is close to the target, hydrogen etching plays a significant role in the film growth, while the effect is negligible for films deposited at a farther distance. The relative quantity of defects was measured by a non-destructive infrared spectroscopy technique that characterized the hydrogen incorporation at dangling nitrogen bonds at defect sites in the deposited films. Despite the films deposited at different substrate tilting angles, the nanowalls of those films were found to consistently grow vertical to the substrate surface, independent of the tilting angle. This implies that chemical processes, rather than physical ones, govern the growth of the nanowalls. The results also reveal that the degree of nanowall crystallization is tunable by varying the growth parameters. Finally, evidence of hydrogen desorption during vacuum annealing is given based on measurements of infrared stretching (E-1u) and bending (A(2u)) modes of the optical phonons, and the H-N vibration mode.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000379456700020 Publication Date 2016-05-25
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1528-7483 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 4.055 Times cited (down) 8 Open Access
Notes Approved Most recent IF: 4.055
Call Number UA @ lucian @ c:irua:144690 Serial 4652
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Author Sankaran, K.J.; Duc Quang Hoang; Korneychuk, S.; Kunuku, S.; Thomas, J.P.; Pobedinskas, P.; Drijkoningen, S.; Van Bael, M.K.; D'Haen, J.; Verbeeck, J.; Leou, K.-C.; Leung, K.T.; Lin, I.-N.; Haenen, K.
Title Hierarchical hexagonal boron nitride nanowall-diamond nanorod heterostructures with enhanced optoelectronic performance Type A1 Journal article
Year 2016 Publication RSC advances Abbreviated Journal Rsc Adv
Volume 6 Issue 93 Pages 90338-90346
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract A superior field electron emission (FEE) source made from a hierarchical heterostructure, where two-dimensional hexagonal boron nitride (hBN) nanowalls were coated on one-dimensional diamond nanorods (DNRs), is fabricated using a simple and scalable method. FEE characteristics of hBN-DNR display a low turn-on field of 6.0 V mu m(-1), a high field enhancement factor of 5870 and a high life-time stability of 435 min. Such an enhancement in the FEE properties of hBN-DNR derives from the distinctive material combination, i.e., high aspect ratio of the heterostructure, good electron transport from the DNR to the hBN nanowalls and efficient field emission of electrons from the hBN nanowalls. The prospective application of these heterostructures is further evidenced by enhanced microplasma devices using hBN-DNR as a cathode, in which the threshold voltage was lowered to 350 V, affirming the role of hBN-DNR in the improvement of electron emission.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000385451800044 Publication Date 2016-09-12
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2046-2069 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.108 Times cited (down) 8 Open Access
Notes The authors like to thank the financial support of the Research Foundation Flanders (FWO) via Research Projects G.0456.12 and G.0044.13N, the Methusalem “NANO” network. KJ Sankaran, and P Pobedinskas are Postdoctoral Fellows of the Research Foundation-Flanders (FWO). Approved Most recent IF: 3.108
Call Number UA @ lucian @ c:irua:144757UA @ admin @ c:irua:144757 Serial 4662
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