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Author | Reijniers, J.; Partoens, B.; Peremans, H. | ||||
Title | Noise-resistant correlation-based alignment of head-related transfer functions for high-fidelity spherical harmonics representation | Type | P3 Proceeding | ||
Year | 2023 | Publication | Abbreviated Journal | ||
Volume | Issue | Pages | |||
Keywords | P3 Proceeding; Engineering sciences. Technology; Engineering Management (ENM); Condensed Matter Theory (CMT) | ||||
Abstract | It is standard practice in virtual reality applications to synthesize binaural audio based on a discrete set of directionally-dependent head-related impulse responses (HRIRs). This set of HRIRs is often time-aligned in a pre-processing step, to allow for high-fidelity interpolation between HRIRs corresponding with neighbouring directions. The fidelity of this operation depends on the similarity of neighbouring aligned HRIRs. The pairwise quality of similarity makes it a difficult criterion to optimize globally and consequently one often resorts to alignment methods based on a specific feature that can be extracted for each HRIR separately, e.g., the first-onset of the peak or the group delay. However, such proxies for similarity are very sensitive to noise and therefore require a high signal-to-noise ratio, which makes them less suitable for processing HRIRs acquired outside an anechoic room. In this paper, we advance a novel alignment method, which maximizes the similarity – defined as the correlation between the full-length HRIRs – between neighbouring aligned HRIRs for all directions at once. We show that this correlation-based alignment procedure outperforms the first-onset alignment with regards to the fidelity of the spherical harmonics representation of both the spectral and interaural time difference (ITD) information, when tested on the KEMAR HRIR and six human HRIRs. Finally, we show that the correlation-based alignment is more robust to noise. | ||||
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Language | Wos | Publication Date | |||
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Series Volume | Series Issue | Edition | |||
ISSN | ISBN | Additional Links | UA library record | ||
Impact Factor | Times cited | Open Access | |||
Notes | Approved | Most recent IF: NA | |||
Call Number | UA @ admin @ c:irua:199714 | Serial | 9062 | ||
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Author | Avetisyan, A.A.; Partoens, B.; Peeters, F.M. | ||||
Title | Electric-field control of the band gap and Fermi energy in graphene multilayers by top and back gates | Type | A1 Journal article | ||
Year | 2009 | Publication | Physical review : B : solid state | Abbreviated Journal | Phys Rev B |
Volume | 80 | Issue | 19 | Pages | 195401,1-195401,11 |
Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
Abstract | It is known that a perpendicular electric field applied to multilayers of graphene modifies the electronic structure near the K point and may induce an energy gap in the electronic spectrum which is tunable by the gate voltage. Here we consider a system of graphene multilayers in the presence of a positively charged top and a negatively charged back gate to control independently the density of electrons on the graphene layers and the Fermi energy of the system. The band structure of three- and four-layer graphene systems in the presence of the top and back gates is obtained using a tight-binding approach. A self-consistent Hartree approximation is used to calculate the induced charges on the different graphene layers. We predict that for opposite and equal charges on the top and bottom layers an energy gap is opened at the Fermi level. For an even number of layers this gap is larger than in the case of an odd number of graphene layers. We find that the circular asymmetry of the spectrum, which is a consequence of the trigonal warping, changes the size of the induced electronic gap, even when the total density of the induced electrons on the graphene layers is low. | ||||
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Publisher | Place of Publication | Lancaster, Pa | Editor | ||
Language | Wos | 000272311000087 | Publication Date | 2009-11-10 | |
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 | 106 | Open Access | |
Notes | Approved | Most recent IF: 3.836; 2009 IF: 3.475 | |||
Call Number | UA @ lucian @ c:irua:80315 | Serial | 883 | ||
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Author | Partoens, B. | ||||
Title | Spinorbit interactions : hide and seek | Type | A1 Journal article | ||
Year | 2014 | Publication | Nature physics | Abbreviated Journal | Nat Phys |
Volume | 10 | Issue | Pages | 333-334 | |
Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
Abstract | It is commonly believed that solids with spatial inversion symmetry do not display spinorbit effects. However, first-principles calculations now reveal unexpected spin structure for centrosymmetric crystals | ||||
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Publisher | Place of Publication | Editor | |||
Language | Wos | 000335371200003 | Publication Date | 2014-04-11 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 1745-2473; 1745-2481 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 22.806 | Times cited | 8 | Open Access | |
Notes | Approved | Most recent IF: 22.806; 2014 IF: 20.147 | |||
Call Number | UA @ lucian @ c:irua:141068 | Serial | 4608 | ||
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Author | Govaerts, K.; Saniz, R.; Partoens, B.; Lamoen, D. | ||||
Title | van der Waals bonding and the quasiparticle band structure of SnO from first principles | Type | A1 Journal article | ||
Year | 2013 | Publication | Physical review : B : condensed matter and materials physics | Abbreviated Journal | Phys Rev B |
Volume | 87 | Issue | 23 | Pages | 235210-235217 |
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT) | ||||
Abstract | In this work we have investigated the structural and electronic properties of SnO, which is built up from layers kept together by van der Waals (vdW) forces. The combination of a vdW functional within density functional theory (DFT) and quasiparticle band structure calculations within the GW approximation provides accurate values for the lattice parameters, atomic positions, and the electronic band structure including the fundamental (indirect) and the optical (direct) band gap without the need of experimental or empirical input. A systematic comparison is made between different levels of self-consistency within the GW approach {following the scheme of Shishkin et al. [Phys. Rev. B 75, 235102 (2007)]} and the results are compared with DFT and hybrid functional results. Furthermore, the effect of the vdW-corrected functional as a starting point for the GW calculation of the band gap has been investigated. Finally, we studied the effect of the vdW functional on the electron charge density. | ||||
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Publisher | Place of Publication | Editor | |||
Language | Wos | 000321061000003 | Publication Date | 2013-07-01 | |
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 | IWT; FWO; Hercules | Approved | Most recent IF: 3.836; 2013 IF: 3.664 | ||
Call Number | UA @ lucian @ c:irua:109596 | Serial | 3835 | ||
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Author | Vansweevelt, R.; Mortet, V.; D' Haen, J.; Ruttens, bart; van Haesendonck, C.; Partoens, B.; Peeters, F.M.; Wagner, P. | ||||
Title | Study on the giant positive magnetoresistance and Hall effect in ultrathin graphite flakes | Type | A1 Journal article | ||
Year | 2011 | Publication | Physica status solidi : A : applications and materials science | Abbreviated Journal | Phys Status Solidi A |
Volume | 208 | Issue | 6 | Pages | 1252-1258 |
Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
Abstract | In this paper, we report on the electronic transport properties of mesoscopic, ultrathin graphite flakes with a thickness corresponding to a stack of 150 graphene layers. The graphite flakes show an unexpectedly strong positive magnetoresistance (PMR) already at room temperature, which scales in good approximation with the square of the magnetic field. Furthermore, we show that the resistivity is unaffected by magnetic fields oriented in plane with the graphene layers. Hall effect measurements indicate that the charge carriers are p-type and their concentration increases with increasing temperature while the mobility is decreasing. The Hall voltage is non-linear in higher magnetic fields. Possible origins of the observed effects are discussed. Ball and stick model of the two topmost carbon layers of the hexagonal graphite structure. | ||||
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Publisher | Place of Publication | Editor | |||
Language | Wos | 000292945800008 | Publication Date | 2011-02-24 | |
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 | 8 | Open Access | |
Notes | ; The authors gratefully acknowledge the support by FWO – Research Foundation Flanders (project G.0159.07 “Structural and electronic properties of biologically modified, graphene-based layers”), by the Federal Belgian Interuniversity Attraction Poles Programme BELSPO (project TAP VI P6/42 “Quantum effects in clusters and nanowires”) and by the Methusalem network “NANO – Antwerp-Hasselt,” funded by the Flemish Community. Technical assistance by Stoffel D. Janssens (magnet calibration and software development), Dr. Hong Yin (AFM-based thickness studies), Dr. Ronald Thoelen (data analysis), and Prof. Hans-Gerd Boyen (XPS spectroscopy) is greatly appreciated. ; | Approved | Most recent IF: 1.775; 2011 IF: 1.463 | ||
Call Number | UA @ lucian @ c:irua:91941 | Serial | 3343 | ||
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Author | Szumniak, P.; Bednarek, S.; Pawlowski, J.; Partoens, B. | ||||
Title | All-electrical control of quantum gates for single heavy-hole spin qubits | Type | A1 Journal article | ||
Year | 2013 | Publication | Physical review : B : condensed matter and materials physics | Abbreviated Journal | Phys Rev B |
Volume | 87 | Issue | 19 | Pages | 195307-195312 |
Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
Abstract | In this paper several nanodevices which realize basic single heavy-hole qubit operations are proposed and supported by time-dependent self-consistent Poisson-Schrodinger calculations using a four band heavy-hole-light-hole model. In particular we propose a set of nanodevices which can act as Pauli X, Y, Z quantum gates and as a gate that acts similar to a Hadamard gate (i.e., it creates a balanced superposition of basis states but with an additional phase factor) on the heavy-hole spin qubit. We also present the design and simulation of a gated semiconductor nanodevice which can realize an arbitrary sequence of all these proposed single quantum logic gates. The proposed devices exploit the self-focusing effect of the hole wave function which allows for guiding the hole along a given path in the form of a stable solitonlike wave packet. Thanks to the presence of the Dresselhaus spin-orbit coupling, the motion of the hole along a certain direction is equivalent to the application of an effective magnetic field which induces in turn a coherent rotation of the heavy-hole spin. The hole motion and consequently the quantum logic operation is initialized only by weak static voltages applied to the electrodes which cover the nanodevice. The proposed gates allow for an all electric and ultrafast (tens of picoseconds) heavy-hole spin manipulation and give the possibility to implement a scalable architecture of heavy-hole spin qubits for quantum computation applications. | ||||
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Publisher | Place of Publication | Editor | |||
Language | Wos | 000319252200003 | Publication Date | 2013-05-21 | |
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 | ; This work was supported by the Polish National Science Center (Grant No. DEC-2011/03/N/ST3/02963), as well as by the “Krakow Interdisciplinary PhD-Project in Nanoscience and Advanced Nanostructures” operated within the Foundation for Polish Science MPD Programme, co-financed by the European Regional Development Fund. This research was supported in part by PL-Grid Infrastructure. ; | Approved | Most recent IF: 3.836; 2013 IF: 3.664 | ||
Call Number | UA @ lucian @ c:irua:109002 | Serial | 88 | ||
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Author | Rønnow, T.F.; Pedersen, T.G.; Partoens, B.; Berthelsen, K.K. | ||||
Title | Variational quantum Monte Carlo study of charged excitons in fractional dimensional space | Type | A1 Journal article | ||
Year | 2011 | Publication | Physical review : B : condensed matter and materials physics | Abbreviated Journal | Phys Rev B |
Volume | 84 | Issue | 3 | Pages | 035316-035316,13 |
Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
Abstract | In this article we study excitons and trions in fractional dimensional spaces using the model suggested by C. Palmer [ J. Phys. A: Math. Gen. 37 6987 (2004)] through variational quantum Monte Carlo. We present a direct approach for estimating the exciton binding energy and discuss the von Neumann rejection- and Metropolis sampling methods. A simple variational estimate of trions is presented which shows good agreement with previous calculations done within the fractional dimensional model presented by D. R. Herrick and F. H. Stillinger [ Phys. Rev. A 11 42 (1975) and J. Math. Phys. 18 1224 (1977)]. We explain the spatial physics of the positive and negative trions by investigating angular and inter-atomic distances. We then examine the wave function and explain the differences between the positive and negative trions with heavy holes. As applications of the fractional dimensional model we study three systems: First we apply the model to estimate the energy of the hydrogen molecular ion H2+. Then we estimate trion binding energies in GaAs-based quantum wells and we demonstrate a good agreement with other theoretical work as well as experimentally observed binding energies. Finally, we apply the results to carbon nanotubes. We find good agreement with recently observed binding energies of the positively charged trion. | ||||
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Publisher | Place of Publication | Editor | |||
Language | Wos | 000293129200012 | Publication Date | 2011-07-26 | |
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 | 15 | Open Access | |
Notes | ; ; | Approved | Most recent IF: 3.836; 2011 IF: 3.691 | ||
Call Number | UA @ lucian @ c:irua:91741 | Serial | 3837 | ||
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Author | Nikolaev, A.V.; Lamoen, D.; Partoens, B. | ||||
Title | Extension of the basis set of linearized augmented plane wave (LAPW) method by using supplemented tight binding basis functions | Type | A1 Journal article | ||
Year | 2016 | Publication | The journal of chemical physics | Abbreviated Journal | J Chem Phys |
Volume | 145 | Issue | 145 | Pages | 014101 |
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT) | ||||
Abstract | In order to increase the accuracy of the linearized augmented plane wave (LAPW) method, we present a new approach where the plane wave basis function is augmented by two different atomic radial components constructed at two different linearization energies corresponding to two different electron bands (or energy windows). We demonstrate that this case can be reduced to the standard treatment within the LAPW paradigm where the usual basis set is enriched by the basis functions of the tight binding type, which go to zero with zero derivative at the sphere boundary. We show that the task is closely related with the problem of extended core states which is currently solved by applying the LAPW method with local orbitals (LAPW+LO). In comparison with LAPW+LO, the number of supplemented basis functions in our approach is doubled, which opens up a new channel for the extension of the LAPW and LAPW+LO basis sets. The appearance of new supplemented basis functions absent in the LAPW+LO treatment is closely related with the existence of the ul-component in the canonical LAPW method. We discuss properties of additional tight binding basis functions and apply the extended basis set for computation of electron energy bands of lanthanum (face and body centered structures) and hexagonal close packed lattice of cadmium. We demonstrate that the new treatment gives lower total energies in comparison with both canonical LAPW and LAPW+LO, with the energy difference more pronounced for intermediate and poor LAPW basis sets. | ||||
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Publisher | Place of Publication | Editor | |||
Language | Wos | 000379584700003 | Publication Date | 2016-07-05 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 0021-9606 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 2.965 | Times cited | 11 | Open Access | |
Notes | A.V.N. acknowledges useful discussions with B. Verberck, E. V. Tkalya, and A. V. Bibikov. | Approved | Most recent IF: 2.965 | ||
Call Number | c:irua:134290 | Serial | 4099 | ||
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Author | Govaerts, K.; Sluiter, M.H.F.; Partoens, B.; Lamoen, D. | ||||
Title | Homologous series of layered structures in binary and ternary Bi-Sb-Te-Se systems : ab initio study | Type | A1 Journal article | ||
Year | 2014 | Publication | Physical review : B : condensed matter and materials physics | Abbreviated Journal | Phys Rev B |
Volume | 89 | Issue | 5 | Pages | 054106-54109 |
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT) | ||||
Abstract | In order to account explicitly for the existence of long-periodic layered structures and the strong structural relaxations in the most common binary and ternary alloys of the Bi-Sb-Te-Se system, we have developed a one-dimensional cluster expansion (CE) based on first-principles electronic structure calculations, which accounts for the Bi and Sb bilayer formation. Excellent interlayer distances are obtained with a van der Waals density functional. It is shown that a CE solely based on pair interactions is sufficient to provide an accurate description of the ground-state energies of Bi-Sb-Te-Se binary and ternary systems without making the data set of ab initio calculated structures unreasonably large. For the binary alloys A1−xQx (A=Sb, Bi; Q=Te, Se), a ternary CE yields an almost continuous series of (meta)stable structures consisting of consecutive A bilayers next to consecutive A2Q3 for 0<x<0.6. For x>0.6, the binary alloy segregates into pure Q and A2Q3. The Bi-Sb system is described by a quaternary CE and is found to be an ideal solid solution stabilized by entropic effects at T≠0 K but with an ordered structure of alternating Bi and Sb layers for x=0.5 at T=0 K. A quintuple CE is used for the ternary Bi-Sb-Te system, where stable ternary layered compounds with an arbitrary stacking of Sb2Te3, Bi2Te3, and Te-Bi-Te-Sb-Te quintuple units are found, optionally separated by mixed Bi/Sb bilayers. Electronic properties of the stable compounds were studied taking spin-orbit coupling into account. | ||||
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Publisher | Place of Publication | Editor | |||
Language | Wos | 000332420900001 | Publication Date | 2014-03-05 | |
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 | 5 | Open Access | |
Notes | Fwo; Hercules | Approved | Most recent IF: 3.836; 2014 IF: 3.736 | ||
Call Number | UA @ lucian @ c:irua:114910 | Serial | 1487 | ||
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Author | Reijniers, J.; Partoens, B.; Steckel, J.; Peremans, H. | ||||
Title | HRTF measurement by means of unsupervised head movements with respect to a single fixed speaker | Type | A1 Journal article | ||
Year | 2020 | Publication | Ieee Access | Abbreviated Journal | Ieee Access |
Volume | 8 | Issue | Pages | 92287-92300 | |
Keywords | A1 Journal article; Mass communications; Engineering Management (ENM); Condensed Matter Theory (CMT); Co-Design of Cyber-Physical Systems (Cosys-Lab) | ||||
Abstract | In a standard state-of-the-art measurement the head-related transfer function (HRTF) is obtained in an anechoic room with an elaborate setup involving multiple calibrated loudspeakers. In search for a simplified method that would open up the possibility for an HRTF measurement in a home environment, it has been suggested that this setup could be replaced with one with a single, fixed loudspeaker. In such a setup, the subject samples different directions by moving the head with respect to this loudspeaker, while the head movements are tracked in some way. In this paper, the feasibility of such an approach is studied. To this end, the HRTF is measured in an unmodified (non-anechoic) room by means of a single external speaker and a high resolution head tracking system. The differences between the dynamically obtained HRTF and the standard static HRTF are investigated, and are shown to be mostly due to variable torso reflections. | ||||
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Publisher | Place of Publication | Editor | |||
Language | Wos | 000539041600001 | Publication Date | 2020-05-15 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 2169-3536 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 3.9 | Times cited | 4 | Open Access | |
Notes | ; This work was supported in part by the Research Foundation Flanders (FWO) under Grant G023619N, and in part by the Agency for Innovation and Entrepreneurship (VLAIO). ; | Approved | Most recent IF: 3.9; 2020 IF: 3.244 | ||
Call Number | UA @ admin @ c:irua:170318 | Serial | 6539 | ||
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Author | Becker, T.; Nelissen, K.; Cleuren, B.; Partoens, B.; Van den Broeck, C. | ||||
Title | Comment on “Generalized exclusion processes : transport coefficients” | Type | A1 Journal article | ||
Year | 2016 | Publication | Physical review E | Abbreviated Journal | Phys Rev E |
Volume | 93 | Issue | 93 | Pages | 046101 |
Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
Abstract | In a recent paper, Arita et al. [Phys. Rev. E 90, 052108 (2014)] consider the transport properties of a class of generalized exclusion processes. Analytical expressions for the transport-diffusion coefficient are derived by ignoring correlations. It is claimed that these expressions become exact in the hydrodynamic limit. In this Comment,we point out that (i) the influence of correlations upon the diffusion does not vanish in the hydrodynamic limit, and (ii) the expressions for the self- and transport diffusion derived by Arita et al. are special cases of results derived in Becker et al. [Phys. Rev. Lett. 111, 110601 (2013)]. | ||||
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Publisher | Place of Publication | Editor | |||
Language | Wos | 000374962100019 | Publication Date | 2016-04-25 | |
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Series Volume | Series Issue | Edition | |||
ISSN | 2470-0045;2470-0053; | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 2.366 | Times cited | 3 | Open Access | |
Notes | Approved | Most recent IF: 2.366 | |||
Call Number | UA @ lucian @ c:irua:141060 | Serial | 4591 | ||
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Author | Pizzochero, M.; Leenaerts, O.; Partoens, B.; Martinazzo, R.; Peeters, F.M. | ||||
Title | Hydrogen adsorption on nitrogen and boron doped graphene | Type | A1 Journal article | ||
Year | 2015 | Publication | Journal of physics : condensed matter | Abbreviated Journal | J Phys-Condens Mat |
Volume | 27 | Issue | 27 | Pages | 425502 |
Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
Abstract | Hydrogen adsorption on boron and nitrogen doped graphene is investigated in detail by means of first-principles calculations. A comprehensive study is performed of the structural, electronic, and magnetic properties of chemisorbed hydrogen atoms and atom pairs near the dopant sites. The main effect of the substitutional atoms is charge doping which is found to greatly affect the adsorption process by increasing the binding energy at the sites closest to the substitutional species. It is also found that doping does not induce magnetism despite the odd number of electrons per atom introduced by the foreign species, and that it quenches the paramagnetic response of chemisorbed H atoms on graphene. Overall, the effects are similar for B and N doping, with only minor differences in the adsorption energetics due to different sizes of the dopant atoms and the accompanying lattice distortions. | ||||
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Language | English | Wos | 000362573500008 | Publication Date | 2015-10-06 |
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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 | 20 | Open Access | |
Notes | This work was supported by the Flemish Science Foundation (FWO-Vl). MP gratefully acknowledges the Condensed Matter Theory group at Universiteit Antwerpen for the hospitality during his stay. | Approved | Most recent IF: 2.649; 2015 IF: 2.346 | ||
Call Number | c:irua:128759 | Serial | 3971 | ||
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Author | Peelaers, H.; Partoens, B.; Peeters, F.M. | ||||
Title | Electronic and dynamical properties of Si/Ge core-shell nanowires | Type | A1 Journal article | ||
Year | 2010 | Publication | Physical review : B : condensed matter and materials physics | Abbreviated Journal | Phys Rev B |
Volume | 82 | Issue | 11 | Pages | 113411-113411,4 |
Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
Abstract | Full ab initio techniques are applied to study the electronic and dynamical properties of free standing, hydrogen-passivated Si/Ge core-shell nanowires oriented along the [110] direction. All studied wires exhibit a direct band gap and are found to be structurally stable. The different contributions of the core and shell atoms to the phonon spectra are identified. The acoustic phonon velocities and the frequencies of some typical optical modes are compared with those of pure Si and Ge nanowires. These depend either on the concentration or on the type of core material. Optical modes are hardened and longitudinal acoustic velocities are softened with decreasing wire diameter. | ||||
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Publisher | Place of Publication | Editor | |||
Language | Wos | 000282270000001 | Publication Date | 2010-09-29 | |
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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 | 13 | Open Access | |
Notes | ; This work was supported by the Flemish Science Foundation (FWO-Vl), the Belgian Science Policy (IAP), and NOI-BOF (University of Antwerp). ; | Approved | Most recent IF: 3.836; 2010 IF: 3.774 | ||
Call Number | UA @ lucian @ c:irua:85421 | Serial | 995 | ||
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Author | Sarmadian, N.; Saniz, R.; Partoens, B.; Lamoen, D. | ||||
Title | Easily doped p-type, low hole effective mass, transparent oxides | Type | A1 Journal article | ||
Year | 2016 | Publication | Scientific reports | Abbreviated Journal | Sci Rep-Uk |
Volume | 6 | Issue | 6 | Pages | 20446 |
Keywords | A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT) | ||||
Abstract | Fulfillment of the promise of transparent electronics has been hindered until now largely by the lack of semiconductors that can be doped p-type in a stable way, and that at the same time present high hole mobility and are highly transparent in the visible spectrum. Here, a high-throughput study based on first-principles methods reveals four oxides, namely X2SeO2, with X = La, Pr, Nd, and Gd, which are unique in that they exhibit excellent characteristics for transparent electronic device applications – i.e., a direct band gap larger than 3.1 eV, an average hole effective mass below the electron rest mass, and good p-type dopability. Furthermore, for La2SeO2 it is explicitly shown that Na impurities substituting La are shallow acceptors in moderate to strong anion-rich growth conditions, with low formation energy, and that they will not be compensated by anion vacancies VO or VSe. | ||||
Address | EMAT, Departement Fysica, Universiteit Antwerpen, Groenenborgerlaan 171, B-2020 Antwerpen, Belgium | ||||
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Publisher | Place of Publication | Editor | |||
Language | English | Wos | 000369568900001 | Publication Date | 2016-02-08 |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 2045-2322 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 4.259 | Times cited | 55 | Open Access | |
Notes | We acknowledge the financial support of FWO-Vlaanderen through project G.0150.13 and of a GOA fund from the University of Antwerp. 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: 4.259 | ||
Call Number | c:irua:131611 | Serial | 4036 | ||
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Author | Li, L.L.; Partoens, B.; Xu, W.; Peeters, F.M. | ||||
Title | Electric-field modulation of linear dichroism and Faraday rotation in few-layer phosphorene | Type | A1 Journal article | ||
Year | 2019 | Publication | 2D materials | Abbreviated Journal | 2D Mater |
Volume | 6 | Issue | 1 | Pages | 015032 |
Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
Abstract | Electro-optical modulators, which use an electric voltage (or an electric field) to modulate a beam of light, are essential elements in present-day telecommunication devices. Using a self-consistent tight-binding approach combined with the standard Kubo formula, we show that the optical conductivity and the linear dichroism of few-layer phosphorene can be modulated by a perpendicular electric field. We find that the field-induced charge screening plays a significant role in modulating the optical conductivity and the linear dichroism. Distinct absorption peaks are induced in the conductivity spectrum due to the strong quantum confinement along the out-of-plane direction and to the field-induced forbidden-to-allowed transitions. The field modulation of the linear dichroism becomes more pronounced with increasing number of phosphorene layers. We also show that the Faraday rotation is present in few-layer phosphorene even in the absence of an external magnetic field. This optical Hall effect is induced by the reduced lattice symmetry of few-layer phosphorene. The Faraday rotation is greatly influenced by the field-induced charge screening and is strongly dependent on the strength of perpendicular electric field and on the number of phosphorene layers. | ||||
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Publisher | Place of Publication | Editor | |||
Language | Wos | 000454321100002 | Publication Date | 2018-11-28 | |
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 | 23 | Open Access | |
Notes | ; This work was financially supported by the Flemish Science Foundation (FWO-Vl) and by the FLAG-ERA project TRANS-2D-TMD. ; | Approved | Most recent IF: 6.937 | ||
Call Number | UA @ admin @ c:irua:156776 | Serial | 5207 | ||
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Author | Sahin, H.; Sivek, J.; Li, S.; Partoens, B.; Peeters, F.M. | ||||
Title | Stone-Wales defects in silicene : formation, stability, and reactivity of defect sites | Type | A1 Journal article | ||
Year | 2013 | Publication | Physical review : B : condensed matter and materials physics | Abbreviated Journal | Phys Rev B |
Volume | 88 | Issue | 4 | Pages | 045434-45436 |
Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
Abstract | During the synthesis of ultrathin materials with hexagonal lattice structure Stone-Wales (SW) type of defects are quite likely to be formed and the existence of such topological defects in the graphenelike structures results in dramatic changes of their electronic and mechanical properties. Here we investigate the formation and reactivity of such SW defects in silicene. We report the energy barrier for the formation of SW defects in freestanding (similar to 2.4 eV) and Ag(111)-supported (similar to 2.8 eV) silicene and found it to be significantly lower than in graphene (similar to 9.2 eV). Moreover, the buckled nature of silicene provides a large energy barrier for the healing of the SW defect and therefore defective silicene is stable even at high temperatures. Silicene with SW defects is semiconducting with a direct band gap of 0.02 eV and this value depends on the concentration of defects. Furthermore, nitrogen substitution in SW-defected silicene shows that the defect lattice sites are the least preferable substitution locations for the N atoms. Our findings show the easy formation of SW defects in silicene and also provide a guideline for band gap engineering in silicene-based materials through such defects. | ||||
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Publisher | Place of Publication | Editor | |||
Language | Wos | 000322113300007 | Publication Date | 2013-07-23 | |
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 | 93 | Open Access | |
Notes | ; This work was supported by the Flemish Science Foundation (FWO-Vl) and the Methusalem foundation of the Flemish government. Computational resources were provided by TUBITAK ULAKBIM, High Performance and Grid Computing Center (TR-Grid e-Infrastructure), and HPC infrastructure of the University of Antwerp (CalcUA) a division of the Flemish Supercomputer Center (VSC), which is funded by the Hercules foundation. H.S. is supported by a FWO Pegasus Marie Curie Fellowship. ; | Approved | Most recent IF: 3.836; 2013 IF: 3.664 | ||
Call Number | UA @ lucian @ c:irua:109805 | Serial | 3162 | ||
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Author | Dabaghmanesh, S.; Saniz, R.; Neyts, E.; Partoens, B. | ||||
Title | Sulfur-alloyed Cr2O3: a new p-type transparent conducting oxide host | Type | A1 Journal article | ||
Year | 2017 | Publication | RSC advances | Abbreviated Journal | Rsc Adv |
Volume | 7 | Issue | 7 | Pages | 4453-4459 |
Keywords | A1 Journal article; Condensed Matter Theory (CMT); Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) | ||||
Abstract | Doped Cr2O3 has been shown to be a p-type transparent conducting oxide (TCO). Its conductivity, however, is low. As for most p-type TCOs, the main problem is the high effective hole mass due to flat valence bands. We use first-principles methods to investigate whether one can increase the valence band dispersion (i.e. reduce the hole mass) by anion alloying with sulfur, while keeping the band gap large enough for transparency. The alloying concentrations considered are given by Cr(4)SxO(6-x), with x = 1-5. To be able to describe the electronic properties of these materials accurately, we first study Cr2O3, examining critically the accuracy of different density functionals and methods, including PBE, PBE+U, HSE06, as well as perturbative approaches within the GW approximation. Our results demonstrate that Cr4S2O4 has an optical band gap of 3.08 eV and an effective hole mass of 1.8 m(e). This suggests Cr4S2O4 as a new p-type TCO host candidate. | ||||
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Publisher | Place of Publication | Editor | |||
Language | Wos | 000393751300030 | Publication Date | 2017-01-16 | |
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 | 9 | Open Access | OpenAccess |
Notes | ; This work was supported by SIM vzw, Technologiepark 935, BE-9052 Zwijnaarde, Belgium, within the InterPoCo project of the H-INT-S horizontal program. The computational resources and services used in this work were provided by the Vlaams Supercomputer Centrum (VSC) and the HPC infrastructure of the University of Antwerp. ; | Approved | Most recent IF: 3.108 | ||
Call Number | UA @ lucian @ c:irua:141543 | Serial | 4528 | ||
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Author | Leenaerts, O.; Peelaers, H.; Hernández-Nieves, A.D.; Partoens, B.; Peeters, F.M. | ||||
Title | First-principles investigation of graphene fluoride and graphane | Type | A1 Journal article | ||
Year | 2010 | Publication | Physical review : B : condensed matter and materials physics | Abbreviated Journal | Phys Rev B |
Volume | 82 | Issue | 19 | Pages | 195436,1-195436,6 |
Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
Abstract | Different stoichiometric configurations of graphane and graphene fluoride are investigated within density-functional theory. Their structural and electronic properties are compared, and we indicate the similarities and differences among the various configurations. Large differences between graphane and graphene fluoride are found that are caused by the presence of charges on the fluorine atoms. A configuration that is more stable than the boat configuration is predicted for graphene fluoride. We also perform GW calculations for the electronic band gap of both graphene derivatives. These band gaps and also the calculated Youngs moduli are at variance with available experimental data. This might indicate that the experimental samples contain a large number of defects or are only partially covered with H or F. | ||||
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Publisher | Place of Publication | Editor | |||
Language | Wos | 000284399200004 | Publication Date | 2010-11-18 | |
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 | 367 | Open Access | |
Notes | ; This work was supported by the Flemish Science Foundation (FWO-V1), the NOI-BOF of the University of Antwerp, the Belgian Science Policy (IAP), and the collaborative project FWO-MINCyT (Grant No. FW/08/01). A.D.H. also acknowledges support from ANPCyT (Grant No. PICT 2008-2236). ; | Approved | Most recent IF: 3.836; 2010 IF: 3.774 | ||
Call Number | UA @ lucian @ c:irua:86916 | Serial | 1212 | ||
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Author | Sarmadian, N.; Saniz, R.; Partoens, B.; Lamoen, D. | ||||
Title | First-principles study of the optoelectronic properties and photovoltaic absorber layer efficiency of Cu-based chalcogenides | Type | A1 Journal article | ||
Year | 2016 | Publication | Journal of applied physics | Abbreviated Journal | J Appl Phys |
Volume | 120 | Issue | 120 | Pages | 085707 |
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT) | ||||
Abstract | Cu-based chalcogenides are promising materials for thin-film solar cells with more than 20% measured cell efficiency. Using first-principles calculations based on density functional theory, the optoelectronic properties of a group of Cu-based chalcogenides Cu2-II-IV-VI4 is studied. They are then screened with the aim of identifying potential absorber materials for photovoltaic applications. The spectroscopic limited maximum efficiency (SLME) introduced by Yu and Zunger [Phys. Rev. Lett. 108, 068701 (2012)] is used as a metric for the screening. After constructing the currentvoltage curve, the SLME is calculated from the maximum power output. The role of the nature of the band gap, direct or indirect, and also of the absorptivity of the studied materials on the maximum theoretical power conversion efficiency is studied. Our results show that Cu2II-GeSe4 with II¼ Cd and Hg, and Cu2-II-SnS4 with II ¼ Cd, Hg, and Zn have a higher theoretical efficiency compared with the materials currently used as absorber layer. |
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Publisher | Place of Publication | Editor | |||
Language | Wos | 000383913400074 | Publication Date | 2016-08-30 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 0021-8979 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 2.068 | Times cited | 29 | Open Access | |
Notes | We acknowledge the financial support from the FWO-Vlaanderen through project G.0150.13N and a GOA fund from the University of Antwerp. 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), bothfunded by the FWO-Vlaanderen and the Flemish Government–department EWI. | Approved | Most recent IF: 2.068 | ||
Call Number | c:irua:135089 | Serial | 4113 | ||
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Author | Li, B.; Partoens, B.; Peeters, F.M.; Magnus, W. | ||||
Title | Dielectric mismatch effect on coupled shallow impurity states in a semiconductor nanowire | Type | A1 Journal article | ||
Year | 2009 | Publication | Physical review : B : solid state | Abbreviated Journal | Phys Rev B |
Volume | 79 | Issue | 8 | Pages | 085306,1-085306,7 |
Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
Abstract | Coupled shallow impurity states in a freestanding semiconductor nanowire and in a semiconductor nanowire surrounded by a metallic gate are studied within the effective-mass approximation. Bonding and antibonding states are found due to the coupling of the two impurities, and their energy converges with increasing distance di between the two impurities. The dependences of the binding energy on the wire radius R, the distance di between the two impurities, and the impurity radial position in the nanowire are examined. | ||||
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Publisher | Place of Publication | Lancaster, Pa | Editor | ||
Language | Wos | 000263816000051 | Publication Date | 2009-02-09 | |
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 | 11 | Open Access | |
Notes | Approved | Most recent IF: 3.836; 2009 IF: 3.475 | |||
Call Number | UA @ lucian @ c:irua:76223 | Serial | 691 | ||
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Author | Willhammar, T.; Sentosun, K.; Mourdikoudis, S.; Goris, B.; Kurttepeli, M.; Bercx, M.; Lamoen, D.; Partoens, B.; Pastoriza-Santos, I.; Pérez-Juste, J.; Liz-Marzán, L.M.; Bals, S.; Van Tendeloo, G. | ||||
Title | Structure and vacancy distribution in copper telluride nanoparticles influence plasmonic activity in the near-infrared | Type | A1 Journal article | ||
Year | 2017 | Publication | Nature communications | Abbreviated Journal | Nat Commun |
Volume | 8 | Issue | 8 | Pages | 14925 |
Keywords | A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT) | ||||
Abstract | Copper chalcogenides find applications in different domains including photonics, photothermal therapy and photovoltaics. CuTe nanocrystals have been proposed as an alternative to noble metal particles for plasmonics. Although it is known that deviations from stoichiometry are a prerequisite for plasmonic activity in the near-infrared, an accurate description of the material and its (optical) properties is hindered by an insufficient understanding of the atomic structure and the influence of defects, especially for materials in their nanocrystalline form. We demonstrate that the structure of Cu1.5±xTe nanocrystals canbe determined using electron diffraction tomography. Real-space high-resolution electron tomography directly reveals the three-dimensional distribution of vacancies in the structure. Through first-principles density functional theory, we furthermore demonstrate that the influence of these vacancies on the optical properties of the nanocrystals is determined. Since our methodology is applicable to a variety of crystalline nanostructured materials, it is expected to provide unique insights concerning structure–property correlations. | ||||
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Publisher | Place of Publication | Editor | |||
Language | Wos | 000397799700001 | Publication Date | 2017-03-30 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 2041-1723 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 12.124 | Times cited | 37 | Open Access | OpenAccess |
Notes | The work was financially supported by the European Research Council through an ERC Starting Grant (#335078-COLOURATOMS). T.W. acknowledges the Swedish Research Council for an international postdoc grant. We acknowledge financial support of FWO-Vlaanderen through project G.0216.14N, G.0369.15N and a postdoctoral research grant to B.G. 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 FWO-Vlaanderen and the Flemish Government–Department EWI. The work was further supported by the Spanish MINECO (MAT2013-45168-R). S.M. thanks the Action ooSupporting Postdoctoral Researchers44 of the Operational Program ‘Education and Lifelong Learning’ (Action’s Beneficiary: General Secretariat for Research and Technology of Greece), which was co-financed by the European Social Fund (ESF) and the Greek State. (ROMEO:green; preprint:; postprint:can ; pdfversion:can); ECAS_Sara | Approved | Most recent IF: 12.124 | ||
Call Number | EMAT @ emat @ c:irua:142203UA @ admin @ c:irua:142203 | Serial | 4538 | ||
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Author | de Backer, J.W.; Vos, W.G.; Gorlé, C.D.; Germonpré, P.; Partoens, B.; Wuyts, F.L.; Parizel, P.M.; de Backer, W. | ||||
Title | Flow analyses in the lower airways: patient-specific model and boundary conditions | Type | A1 Journal article | ||
Year | 2008 | Publication | Medical engineering and physics | Abbreviated Journal | Med Eng Phys |
Volume | 30 | Issue | 7 | Pages | 872-879 |
Keywords | A1 Journal article; Condensed Matter Theory (CMT); Antwerp Surgical Training, Anatomy and Research Centre (ASTARC); Laboratory Experimental Medicine and Pediatrics (LEMP) | ||||
Abstract | Computational fluid dynamics (CFD) is increasingly applied in the respiratory domain. The ability to simulate the flow through a bifurcating tubular system has increased the insight into the internal flow dynamics and the particular characteristics of respiratory flows such as secondary motions and inertial effects. The next step in the evolution is to apply the technique to patient-specific cases, in order to provide more information about pathological airways. This study presents a patient-specific approach where both the geometry and the boundary conditions (BC) are based on individual imaging methods using computed tomography (CT). The internal flow distribution of a 73-year-old female suffering from chronic obstructive pulmonary disease (COPD) is assessed. The validation is performed through the comparison of lung ventilation with gamma scintigraphy. The results show that in order to obtain agreement within the accuracy limits of the gamma scintigraphy scan, both the patient-specific geometry and the BC (driving pressure) play a crucial role. A minimal invasive test (CT scan) supplied enough information to perform an accurate CFD analysis. In the end it was possible to capture the pathological features of the respiratory system using the imaging and computational fluid dynamics techniques. This brings the introduction of this new technique in the clinical practice one step closer. | ||||
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Publisher | Place of Publication | London | Editor | ||
Language | Wos | 000259768300009 | Publication Date | 2007-12-26 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 1350-4533; | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 1.819 | Times cited | 82 | Open Access | |
Notes | Approved | Most recent IF: 1.819; 2008 IF: 2.216 | |||
Call Number | UA @ lucian @ c:irua:71693 | Serial | 1224 | ||
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Author | Rahemi, V.; Sarmadian, N.; Anaf, W.; Janssens, K.; Lamoen, D.; Partoens, B.; De Wael, K. | ||||
Title | Unique opto-electronic structure and photo reduction properties of sulfur doped lead chromates explaining their instability in paintings | Type | A1 Journal article | ||
Year | 2017 | Publication | Analytical chemistry | Abbreviated Journal | Anal Chem |
Volume | 89 | Issue | 89 | Pages | 3326-3334 |
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT); AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) | ||||
Abstract | Chrome yellow refers to a group of synthetic inorganic pigments that became popular as an artists material from the second quarter of the 19th century. The color of the pigment, in which the chromate ion acts as a chromophore, is related to its chemical composition (PbCr1-xSxO4, with 0≤x≤0.8) and crystalline structure (monoclinic/orthorhombic). Their shades range from the yellow-orange to the paler yellow tones with increasing sulfate amount. These pigments show remarkable signs of degradation after limited time periods. Pure PbCrO4 (crocoite in its natural form) has a deep yellow color and is relatively stable, while the co-precipitate with lead sulfate (PbCr1-xSxO4) has a paler shade and seems to degrade faster. This degradation is assumed to be related to the reduction of Cr(VI) to Cr(III). We show that on increasing the sulfur(S)-content in chrome yellow, the band gap increases. Typically, when increasing the band gap, one might assume that a decrease in photo activity is the result. However, the photo activity relative to the Cr content, and thus Cr reduction, of sulfur-rich PbCr1-xSxO4 is found to be much higher compared to the sulfur-poor or non-doped lead chromates. This discrepancy can be explained by the evolution of the crystal and electronic structure as function of the sulfur content: first-principles density functional theory calculations show that both the absorption coefficient and reflection coefficients of the lead chromates change as a result of the sulfate doping in such a way that the generation of electron-hole pairs under illumination relative to the total Cr content increases. These changes in the material properties explain why paler shade yellow colors of this pigment are more prone to discoloration. The electronic structure calculations also demonstrate that lead chromate and its co-precipitates are p-type semiconductors, which explains the observed reduction reaction. As understanding this phenomenon is valuable in the field of cultural heritage, this study is the first joint action of photo-electrochemical measurements and first-principles calculations to approve the higher tendency of sulfur-rich lead chromates to darken. | ||||
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Corporate Author | Thesis | ||||
Publisher | Place of Publication | Washington, D.C. | Editor | ||
Language | Wos | 000397478300015 | Publication Date | 2017-02-23 | |
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 | 7 | Open Access | OpenAccess |
Notes | ; 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. The BOF-GOA action SOLARPAINT of the University of Antwerp Research Council is acknowledged for financial support. W.A. acknowledges support from BELSPO project S2-ART. Dr. L. Monico and Dr. C. Miliani (ISTM, Perugia) are gratefully acknowledged for helpful discussions and for providing some of the initial batches of the materials studied. ; | Approved | Most recent IF: 6.32 | ||
Call Number | UA @ lucian @ c:irua:140886 | Serial | 4451 | ||
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Author | Bercx, M.; Sarmadian, N.; Saniz, R.; Partoens, B.; Lamoen, D. | ||||
Title | First-principles analysis of the spectroscopic limited maximum efficiency of photovoltaic absorber layers for CuAu-like chalcogenides and silicon | Type | A1 Journal article | ||
Year | 2016 | Publication | Physical chemistry, chemical physics | Abbreviated Journal | Phys Chem Chem Phys |
Volume | 18 | Issue | 18 | Pages | 20542-20549 |
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT) | ||||
Abstract | Chalcopyrite semiconductors are of considerable interest for application as absorber layers in thin-film photovoltaic cells. When growing films of these compounds, however, they are often found to contain CuAu-like domains, a metastable phase of chalcopyrite. It has been reported that for CuInS2, the presence of the CuAu-like phase improves the short circuit current of the chalcopyrite-based photovoltaic cell. We investigate the thermodynamic stability of both phases for a selected list of I-III-VI2 materials using a first-principles density functional theory approach. For the CuIn-VI2 compounds, the difference in formation energy between the chalcopyrite and CuAu-like phase is found to be close to 2 meV per atom, indicating a high likelihood of the presence of CuAu-like domains. Next, we calculate the spectroscopic limited maximum efficiency (SLME) of the CuAu-like phase and compare the results with those of the corresponding chalcopyrite phase. We identify several candidates with a high efficiency, such as CuAu-like CuInS2, for which we obtain an SLME of 29% at a thickness of 500 nm. We observe that the SLME can have values above the Shockley-Queisser (SQ) limit, and show that this can occur because the SQ limit assumes the absorptivity to be a step function, thus overestimating the radiative recombination in the detailed balance approach. This means that it is possible to find higher theoretical efficiencies within this framework simply by calculating the J-V characteristic with an absorption spectrum. Finally, we expand our SLME analysis to indirect band gap absorbers by studying silicon, and find that the SLME quickly overestimates the reverse saturation current of indirect band gap materials, drastically lowering their calculated efficiency. | ||||
Address | EMAT & CMT groups, Department of Physics, University of Antwerp, Campus Groenenborger, Groenenborgerlaan 171, 2020 Antwerp, Belgium. marnik.bercx@uantwerpen.be | ||||
Corporate Author | Thesis | ||||
Publisher | Place of Publication | Editor | |||
Language | English | Wos | 000381428600058 | Publication Date | 2016-07-08 |
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 | 34 | Open Access | |
Notes | We acknowledge financial support of FWO-Vlaanderen through projects G.0150.13N and G.0216.14N and ERA-NET RUS Plus/FWO, Grant G0D6515N. 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 FWO FWOVlaanderen. | Approved | Most recent IF: 4.123 | ||
Call Number | c:irua:135091 | Serial | 4112 | ||
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Author | Dixit, H.; Lamoen, D.; Partoens, B. | ||||
Title | Quasiparticle band structure of rocksalt-CdO determined using maximally localized Wannier functions | Type | A1 Journal article | ||
Year | 2013 | Publication | Journal of physics : condensed matter | Abbreviated Journal | J Phys-Condens Mat |
Volume | 25 | Issue | 3 | Pages | 035501-35505 |
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT) | ||||
Abstract | CdO in the rocksalt structure is an indirect band gap semiconductor. Thus, in order to determine its band gap one needs to calculate the complete band structure. However, in practice, the exact evaluation of the quasiparticle band structure for the large number of k-points which constitute the different symmetry lines in the Brillouin zone can be an extremely demanding task compared to the standard density functional theory (DFT) calculation. In this paper we report the full quasiparticle band structure of CdO using a plane-wave pseudopotential approach. In order to reduce the computational effort and time, we make use of maximally localized Wannier functions (MLWFs). The MLWFs offer a highly accurate method for interpolation of the DFT or GW band structure from a coarse k-point mesh in the irreducible Brillouin zone, resulting in a much reduced computational effort. The present paper discusses the technical details of the scheme along with the results obtained for the quasiparticle band gap and the electron effective mass. | ||||
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Publisher | Place of Publication | London | Editor | ||
Language | Wos | 000313100500010 | Publication Date | 2012-12-12 | |
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ISSN | 0953-8984;1361-648X; | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 2.649 | Times cited | 7 | Open Access | |
Notes | Fwo | Approved | Most recent IF: 2.649; 2013 IF: 2.223 | ||
Call Number | UA @ lucian @ c:irua:105296 | Serial | 2801 | ||
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Author | Mayda, S.; Monico, L.; Krishnan, D.; De Meyer, S.; Cotte, M.; Garrevoet, J.; Falkenberg, G.; Sandu, I.C.A.; Partoens, B.; Lamoen, D.; Romani, A.; Miliani, C.; Verbeeck, J.; Janssens, K. | ||||
Title | A combined experimental and computational approach to understanding CdS pigment oxidation in a renowned early 20th century painting | Type | A1 Journal article | ||
Year | 2023 | Publication | Chemistry of materials | Abbreviated Journal | |
Volume | 35 | Issue | 24 | Pages | 10403-10415 |
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT); Antwerp X-ray Imaging and Spectroscopy (AXIS) | ||||
Abstract | Cadmium sulfide (CdS)-based yellow pigments have been used in a number of early 20th century artworks, including The Scream series painted by Edvard Munch. Some of these unique paintings are threatened by the discoloration of these CdS-based yellow oil paints because of the oxidation of the original sulfides to sulfates. The experimental data obtained here prove that moisture and cadmium chloride compounds play a key role in promoting such oxidation. To clarify how these two factors effectively prompt the process, we studied the band alignment between CdS, CdCl2, and Cd-(OH)Cl as well as the radicals center dot OH and H3O center dot by density functional theory (DFT) methods. Our results show that a stack of several layers of Cd-(OH)Cl creates a pocket of positive holes at the Cl-terminated surface and a pocket of electrons at the OH-terminated surface by leading in a difference in ionization energy at both surfaces. The resulting band alignment indicates that Cd-(OH)Cl can indeed play the role of an oxidative catalyst for CdS in a moist environment, thus providing an explanation for the experimental evidence. | ||||
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Publisher | Place of Publication | Editor | |||
Language | Wos | 001133000900001 | Publication Date | 2023-12-08 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 0897-4756; 1520-5002 | ISBN | Additional Links | UA library record; WoS full record | |
Impact Factor | 8.6 | Times cited | Open Access | ||
Notes | The experimental research on the cadmium yellow powders/paint mock-ups and The Scream (ca. 1910) was financially supported by the European Union, research projects IPERION-CH (H2020-INFRAIA-2014-2015, GA no. 654028) and IPERION-HS (H2020-INFRAIA-2019-1, GA no. 871034) and the project AMIS within the program Dipartimenti di Eccellenza 2018-2022 (funded by MUR and the University of Perugia). For the beamtime grants received, the authors thank the ESRF-ID21 beamline (experiments HG64 and HG95), the DESY-P06 beamline, a member of the Helmholtz Association HGF (experiments I-20130221 EC and I-20160126 EC), and the project CALIPSOplus under the GA no. 730872 from the E.U. Framework Programme for Research and Innovation Horizon 2020. All of the staff of the MUNCH Museum (Conservation Department) is acknowledged for their collaboration. 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 FWO – Vlaanderen and the Flemish Government, Department EWI. | Approved | Most recent IF: 8.6; 2023 IF: 9.466 | ||
Call Number | UA @ admin @ c:irua:202836 | Serial | 8999 | ||
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Author | Li, L.L.; Partoens, B.; Peeters, F.M. | ||||
Title | Tuning the electronic properties of gated multilayer phosphorene : a self-consistent tight-binding study | Type | A1 Journal article | ||
Year | 2018 | Publication | Physical review B | Abbreviated Journal | Phys Rev B |
Volume | 97 | Issue | 15 | Pages | 155424 |
Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
Abstract | By taking account of the electric-field-induced charge screening, a self-consistent calculation within the framework of the tight-binding approach is employed to obtain the electronic band structure of gated multilayer phosphorene and the charge densities on the different phosphorene layers. We find charge density and screening anomalies in single-gated multilayer phosphorene and electron-hole bilayers in dual-gated multilayer phosphorene. Due to the unique puckered lattice structure, both intralayer and interlayer charge screenings are important in gated multilayer phosphorene. We find that the electric-field tuning of the band structure of multilayer phosphorene is distinctively different in the presence and absence of charge screening. For instance, it is shown that the unscreened band gap of multilayer phosphorene decreases dramatically with increasing electric-field strength. However, in the presence of charge screening, the magnitude of this band-gap decrease is significantly reduced and the reduction depends strongly on the number of phosphorene layers. Our theoretical results of the band-gap tuning are compared with recent experiments and good agreement is found. | ||||
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Corporate Author | Thesis | ||||
Publisher | American Physical Society | Place of Publication | New York, N.Y | Editor | |
Language | Wos | 000430459400005 | Publication Date | 2018-04-20 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 2469-9969; 2469-9950 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 3.836 | Times cited | 26 | Open Access | |
Notes | ; This work was financially supported by the Flemish Science Foundation (FWO-Vl). ; | Approved | Most recent IF: 3.836 | ||
Call Number | UA @ lucian @ c:irua:150752UA @ admin @ c:irua:150752 | Serial | 4988 | ||
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Author | Van Boxem, R.; Partoens, B.; Verbeeck, J. | ||||
Title | Rutherford scattering of electron vortices | Type | A1 Journal article | ||
Year | 2014 | Publication | Physical review : A : atomic, molecular and optical physics | Abbreviated Journal | Phys Rev A |
Volume | 89 | Issue | 3 | Pages | 032715-32719 |
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT) | ||||
Abstract | By considering a cylindrically symmetric generalization of a plane wave, the first-order Born approximation of screened Coulomb scattering unfolds two new dimensions in the scattering problem: transverse momentum and orbital angular momentum of the incoming beam. In this paper, the elastic Coulomb scattering amplitude is calculated analytically for incoming Bessel beams. This reveals novel features occurring for wide-angle scattering and quantitative insights for small-angle vortex scattering. The result successfully generalizes the well-known Rutherford formula, incorporating transverse and orbital angular momentum into the formalism. | ||||
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Corporate Author | Thesis | ||||
Publisher | Place of Publication | Lancaster, Pa | Editor | ||
Language | Wos | 000333690500008 | Publication Date | 2014-03-31 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 1050-2947;1094-1622; | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 2.925 | Times cited | 34 | Open Access | |
Notes | 312483-Esteem2; N246791 – Countatoms; 278510 Vortex; esteem2jra1; esteem2jra3 ECASJO_; | Approved | Most recent IF: 2.925; 2014 IF: 2.808 | ||
Call Number | UA @ lucian @ c:irua:115562UA @ admin @ c:irua:115562 | Serial | 2936 | ||
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Author | Hu, L.; Amini, M.N.; Wu, Y.; Jin, Z.; Yuan, J.; Lin, R.; Wu, J.; Dai, Y.; He, H.; Lu, Y.; Lu, J.; Ye, Z.; Han, S.-T.; Ye, J.; Partoens, B.; Zeng, Y.-J.; Ruan, S. | ||||
Title | Charge transfer doping modulated raman scattering and enhanced stability of black phosphorus quantum dots on a ZnO nanorod | Type | A1 Journal article | ||
Year | 2018 | Publication | Advanced Optical Materials | Abbreviated Journal | Adv Opt Mater |
Volume | 6 | Issue | 15 | Pages | 1800440 |
Keywords | A1 Journal article; Condensed Matter Theory (CMT); Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) | ||||
Abstract | Black phosphorus (BP) has recently triggered an unprecedented interest in the 2D community. However, many of its unique properties are not exploited and the well-known environmental vulnerability is not conquered. Herein, a type-I mixed-dimensional (0D-1D) van der Waals heterojunction is developed, where three-atomic-layer BP quantum dots (QDs) are assembled on a single ZnO nanorod (NR). By adjusting the indium (In) content in ZnO NRs, the degree and even the direction of surface charge transfer doping within the heterojunction can be tuned, which result in selective Raman scattering enhancements between ZnO and BP. The maximal enhancement factor is determined as 4340 for BP QDs with sub-ppm level. Furthermore, an unexpected long-term ambient stability (more than six months) of BP QDs is revealed, which is ascribed to the electron doping from ZnO:In NRs. The first demonstration of selective Raman enhancements between two inorganic semiconductors as well as the improved stability of BP shed light on this emerging 2D material. | ||||
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Corporate Author | Thesis | ||||
Publisher | Place of Publication | Editor | |||
Language | Wos | 000440815200023 | Publication Date | 2018-05-18 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 2195-1071 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 6.875 | Times cited | 37 | Open Access | Not_Open_Access |
Notes | ; L. Hu and M. N. Amini contributed equally to this work. This work was supported by the National Natural Science Foundation of China under Grant Nos. 51502178, 81571763 and 81622026, the Shenzhen Science and Technology Project under Grant Nos. JCYJ20150324141711644, JCYJ20170412105400428, KQJSCX20170727101208249 and JCYJ20170302153853962. Parts of the computational calculations were carried out using the HPC infrastructure at University of Antwerp (CalcUA), a division of the Flemish Supercomputer Center VSC, supported financially by the FWO-Vlaanderen and the Flemish Government (EWI Department). L. H. acknowledges the PhD Start-up Fund of Natural Science Foundation of Guangdong Province under Grand No. 2017A030310072. J. Y. acknowledges the funding of Shanghai Jiao Tong University (Nos. YG2016MS51 and YG2017MS54). ; | Approved | Most recent IF: 6.875 | ||
Call Number | UA @ lucian @ c:irua:153112UA @ admin @ c:irua:153112 | Serial | 5082 | ||
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Author | Rønnow, T.F.; Pedersen, T.G.; Partoens, B. | ||||
Title | Biexciton binding energy in fractional dimensional semiconductors | Type | A1 Journal article | ||
Year | 2012 | Publication | Physical review : B : condensed matter and materials physics | Abbreviated Journal | Phys Rev B |
Volume | 85 | Issue | 4 | Pages | 045412-045412,7 |
Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
Abstract | Biexcitons in fractional dimensional spaces are studied using variational quantum Monte Carlo. We investigate the biexciton binding energy as a function of the electron-hole mass fraction sigma as well as study the dimensional dependence of biexcitons for sigma = 0 and sigma = 1. As our first application of this model we treat the H(2) molecule in two and three dimensions. Next we investigate biexcitons in carbon nanotubes within the fractional dimensional model. To this end we find a relation between the nanotube radius and the effective dimension. The results of both applications are compared with results obtained using different models and we find a reasonable agreement. Within the fractional dimensional model we find that the biexciton binding energy in carbon nanotubes accurately scales as E(B)(r,epsilon) = 1280 meV angstrom/(r epsilon), as a function of radius r and the dielectric screening epsilon. | ||||
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Publisher | Place of Publication | Editor | |||
Language | Wos | 000298922200008 | Publication Date | 2012-01-06 | |
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 | 21 | Open Access | |
Notes | ; ; | Approved | Most recent IF: 3.836; 2012 IF: 3.767 | ||
Call Number | UA @ lucian @ c:irua:96234 | Serial | 231 | ||
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