Records |
Author |
Verleysen, E.; Bender, H.; Richard, O.; Schryvers, D.; Vandervorst, W. |
Title |
Compositional characterization of nickel silicides by HAADF-STEM imaging |
Type |
A1 Journal article |
Year |
2011 |
Publication |
Journal of materials science |
Abbreviated Journal |
J Mater Sci |
Volume |
46 |
Issue |
7 |
Pages |
2001-2008 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
A methodology for the quantitative compositional characterization of nickel silicides by high angle annular dark field scanning transmission electron microscopy (HAADF-STEM) imaging is presented. HAADF-STEM images of a set of nickel silicide reference samples Ni3Si, Ni31Si12, Ni2Si, NiSi and NiSi2 are taken at identical experimental conditions. The correlation between sample thickness and HAADF-STEM intensity is discussed. In order to quantify the relationship between the experimental Z-contrast intensities and the composition of the analysed layers, the ratio of the HAADF-STEM intensity to the sample thickness or to the intensity of the silicon substrate is determined for each nickel silicide reference sample. Diffraction contrast is still detected on the HAADF-STEM images, even though the detector is set at the largest possible detection angle. The influence on the quantification results of intensity fluctuations caused by diffraction contrast and channelling is examined. The methodology is applied to FUSI gate devices and to horizontal TFET devices with different nickel silicides formed on source, gate and drain. It is shown that, if the elements which are present are known, this methodology allows a fast quantitative 2-dimensional compositional analysis. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
London |
Editor |
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Language |
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Wos |
000286633000002 |
Publication Date |
2011-01-06 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume ![sorted by Series Volume (numeric) field, ascending order (up)](img/sort_asc.gif) |
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Series Issue |
|
Edition |
|
ISSN |
0022-2461;1573-4803; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
2.599 |
Times cited |
1 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 2.599; 2011 IF: 2.015 |
Call Number |
UA @ lucian @ c:irua:88950 |
Serial |
446 |
Permanent link to this record |
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Author |
Parente, A.; Gorlé, C.; van Beeck, J.; Benocci, C. |
Title |
A comprehensive modelling approach for the neutral atmospheric boundary layer : consistent inflow conditions, wall function and turbulence model |
Type |
A1 Journal article |
Year |
2011 |
Publication |
Boundary-layer meteorology |
Abbreviated Journal |
Bound-Lay Meteorol |
Volume |
140 |
Issue |
3 |
Pages |
411-428 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
We report on a novel approach for the Reynolds-averaged Navier-Stokes (RANS) modelling of the neutral atmospheric boundary layer (ABL), using the standard k− turbulence model. A new inlet condition for turbulent kinetic energy is analytically derived from the solution of the k− model transport equations, resulting in a consistent set of fully developed inlet conditions for the neutral ABL. A modification of the standard k− model is also employed to ensure consistency between the inlet conditions and the turbulence model. In particular, the turbulence model constant C μ is generalized as a location-dependent parameter, and a source term is introduced in the transport equation for the turbulent dissipation rate. The application of the proposed methodology to cases involving obstacles in the flow is made possible through the implementation of an algorithm, which automatically switches the turbulence model formulation when going from the region where the ABL is undisturbed to the region directly affected by the building. Finally, the model is completed with a slightly modified version of the Richards and Hoxey rough-wall boundary condition. The methodology is implemented and tested in the commercial code Ansys Fluent 12.1. Results are presented for a neutral boundary layer over flat terrain and for the flow around a single building immersed in an ABL. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Dordrecht |
Editor |
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Language |
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Wos |
000293923800004 |
Publication Date |
2011-05-25 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume ![sorted by Series Volume (numeric) field, ascending order (up)](img/sort_asc.gif) |
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Series Issue |
|
Edition |
|
ISSN |
0006-8314;1573-1472; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
2.573 |
Times cited |
54 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 2.573; 2011 IF: 1.737 |
Call Number |
UA @ lucian @ c:irua:92341 |
Serial |
450 |
Permanent link to this record |
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|
Author |
Bogaerts, A.; Eckert, M.; Mao, M.; Neyts, E. |
Title |
Computer modelling of the plasma chemistry and plasma-based growth mechanisms for nanostructured materials |
Type |
A1 Journal article |
Year |
2011 |
Publication |
Journal of physics: D: applied physics |
Abbreviated Journal |
J Phys D Appl Phys |
Volume |
44 |
Issue |
17 |
Pages |
174030-174030,16 |
Keywords |
A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
Abstract |
In this review paper, an overview is given of different modelling efforts for plasmas used for the formation and growth of nanostructured materials. This includes both the plasma chemistry, providing information on the precursors for nanostructure formation, as well as the growth processes itself. We limit ourselves to carbon (and silicon) nanostructures. Examples of the plasma modelling comprise nanoparticle formation in silane and hydrocarbon plasmas, as well as the plasma chemistry giving rise to carbon nanostructure formation, such as (ultra)nanocrystalline diamond ((U)NCD) and carbon nanotubes (CNTs). The second part of the paper deals with the simulation of the (plasma-based) growth mechanisms of the same carbon nanostructures, i.e. (U)NCD and CNTs, both by mechanistic modelling and detailed atomistic simulations. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
London |
Editor |
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Language |
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Wos |
000289512700030 |
Publication Date |
2011-04-15 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume ![sorted by Series Volume (numeric) field, ascending order (up)](img/sort_asc.gif) |
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Series Issue |
|
Edition |
|
ISSN |
0022-3727;1361-6463; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
2.588 |
Times cited |
25 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 2.588; 2011 IF: 2.544 |
Call Number |
UA @ lucian @ c:irua:88364 |
Serial |
463 |
Permanent link to this record |
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|
Author |
Tinck, S.; Bogaerts, A. |
Title |
Computer simulations of an oxygen inductively coupled plasma used for plasma-assisted atomic layer deposition |
Type |
A1 Journal article |
Year |
2011 |
Publication |
Plasma sources science and technology |
Abbreviated Journal |
Plasma Sources Sci T |
Volume |
20 |
Issue |
1 |
Pages |
015008-015008,10 |
Keywords |
A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
Abstract |
In this paper, an O2 inductively coupled plasma used for plasma enhanced atomic layer deposition of Al2O3 thin films is investigated by means of modeling. This work intends to provide more information about basic plasma properties such as species densities and species fluxes to the substrate as a function of power and pressure, which might be hard to measure experimentally. For this purpose, a hybrid model developed by Kushner et al is applied to calculate the plasma characteristics in the reactor volume for different chamber pressures ranging from 1 to 10 mTorr and different coil powers ranging from 50 to 500 W. Density profiles of the various oxygen containing plasma species are reported as well as fluxes to the substrate under various operating conditions. Furthermore, different orientations of the substrate, which can be placed vertically or horizontally in the reactor, are taken into account. In addition, special attention is paid to the recombination process of atomic oxygen on the different reactor walls under the stated operating conditions. From this work it can be concluded that the plasma properties change significantly in different locations of the reactor. The plasma density near the cylindrical coil is high, while it is almost negligible in the neighborhood of the substrate. Ion and excited species fluxes to the substrate are found to be very low and negligible. Finally, the orientation of the substrate has a minor effect on the flux of O2, while it has a significant effect on the flux of O. In the horizontal configuration, the flux of atomic oxygen can be up to one order of magnitude lower than in the vertical configuration. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
Institute of Physics |
Place of Publication |
Bristol |
Editor |
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Language |
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Wos |
000286592200009 |
Publication Date |
2011-01-08 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume ![sorted by Series Volume (numeric) field, ascending order (up)](img/sort_asc.gif) |
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Series Issue |
|
Edition |
|
ISSN |
0963-0252;1361-6595; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
3.302 |
Times cited |
11 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 3.302; 2011 IF: 2.521 |
Call Number |
UA @ lucian @ c:irua:85285 |
Serial |
467 |
Permanent link to this record |
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|
Author |
Bogaerts, A.; Aghaei, M.; Autrique, D.; Lindner, H.; Chen, Z.; Wendelen, W. |
Title |
Computer simulations of laser ablation, plume expansion and plasma formation |
Type |
H1 Book chapter |
Year |
2011 |
Publication |
|
Abbreviated Journal |
|
Volume |
|
Issue |
|
Pages |
1-10 |
Keywords |
H1 Book chapter; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
Abstract |
|
Address |
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Corporate Author |
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Thesis |
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Publisher |
Trans Tech |
Place of Publication |
Aedermannsdorf |
Editor |
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Language |
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Wos |
000292658900001 |
Publication Date |
2011-04-20 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume ![sorted by Series Volume (numeric) field, ascending order (up)](img/sort_asc.gif) |
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Series Issue |
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Edition |
|
ISSN |
1662-8985; |
ISBN |
978-3-03785-081-7 |
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
|
Times cited |
8 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: NA |
Call Number |
UA @ lucian @ c:irua:88340 |
Serial |
470 |
Permanent link to this record |
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Author |
Chaves, A.; Komendová, L.; Milošević, M.V.; Andrade, J.S.; Farias, G.A.; Peeters, F.M. |
Title |
Conditions for nonmonotonic vortex interaction in two-band superconductors |
Type |
A1 Journal article |
Year |
2011 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
Volume |
83 |
Issue |
21 |
Pages |
214523-214523,6 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
We describe a semianalytic approach to the two-band Ginzburg-Landau theory, which predicts the behavior of vortices in two-band superconductors. We show that the character of the short-range vortex-vortex interaction is determined by the sign of the normal domain-superconductor interface energy, in analogy with the conventional differentiation between type I and type II superconductors. However, we also show that the long-range interaction is determined by a modified Ginzburg-Landau parameter κ*, different from the standard κ of a bulk superconductor. This opens the possibility for nonmonotonic vortex-vortex interaction, which is temperature dependent, and can be further tuned by alterations of the material on the microscopic scale. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000292252300009 |
Publication Date |
2011-06-30 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume ![sorted by Series Volume (numeric) field, ascending order (up)](img/sort_asc.gif) |
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Series Issue |
|
Edition |
|
ISSN |
1098-0121;1550-235X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
3.836 |
Times cited |
46 |
Open Access |
|
Notes |
; Discussions with A. Moreira, A. Shanenko, R. Prozorov, and A. Golubov are gratefully acknowledged. This work was supported by the Flemish Science Foundation (FWO-Vl), the Belgian Science Policy (IAP), the bilateral project FWO-CNPq, CAPES, and PRONEX/CNPq/FUNCAP. ; |
Approved |
Most recent IF: 3.836; 2011 IF: 3.691 |
Call Number |
UA @ lucian @ c:irua:90922 |
Serial |
477 |
Permanent link to this record |
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Author |
Peelaers, H.; Partoens, B.; Giantomassi, M.; Rangel, T.; Goossens, E.; Rignanese, G.-M.; Gonze, X.; Peeters, F.M. |
Title |
Convergence of quasiparticle band structures of Si and Ge nanowires in the GW approximation and the validity of scissor shifts |
Type |
A1 Journal article |
Year |
2011 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
Volume |
83 |
Issue |
4 |
Pages |
045306-045306,6 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
Starting from fully converged density-functional theory calculations, the quasiparticle corrections are calculated for different sized Si and Ge nanowires using the GW approximation. The effectiveness of recently developed techniques in speeding up the convergence of the quasiparticle calculations is demonstrated. The complete quasiparticle band structures are also obtained using an interpolation technique based on maximallylocalized Wannier functions. From the quasiparticle results, we assess the correctness of the commonly applied scissor-shift correction. Dispersion changes are observed, which are also reflected in changes in the effective band masses calculated taking into account quasiparticle corrections. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000286771400004 |
Publication Date |
2011-01-21 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume ![sorted by Series Volume (numeric) field, ascending order (up)](img/sort_asc.gif) |
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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 |
18 |
Open Access |
|
Notes |
; We are grateful to Yann Pouillon for valuable technical support with the build system of ABINIT, related to the WANNIER90 library. This work was supported by the Flemish Science Foundation (FWO-Vl) and by the Interuniversity Attraction Poles Program (P6/42)-Belgian State-Belgian Science Policy. X. G. and G.-M. R. acknowledge funding from the EU's 7th Framework Programme through the ETSF I3 e-Infrastructure project (Grant No. 211956), the Communaute francaise de Belgique through the Action de Recherche Concertee 07/12-003 “Nanosystemes hybrides metal-organiques,” and the Wallon Region Project No. 816849 “ European Theoretical Spectroscopy Facility” (WALL ETSF). M. G. acknowledges funding from the FRFC Project No. 2.4.589.09.F. ; |
Approved |
Most recent IF: 3.836; 2011 IF: 3.691 |
Call Number |
UA @ lucian @ c:irua:86905 |
Serial |
510 |
Permanent link to this record |
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Author |
Klimczuk, T.; Wang, C.H.; Lawrence, J.M.; Xu, Q.; Durakiewicz, T.; Ronning, F.; Llobet, A.; Trouw, F.; Kurita, N.; Tokiwa, Y.; Lee, H.o.; Booth, C.H.; Gardner, J.S.; Bauer, E.D.; Joyce, J.J.; Zandbergen, H.W.; Movshovich, R.; Cava, R.J.; Thompson, J.D.; |
Title |
Crystal fields, disorder, and antiferromagnetic short-range order in Yb0.24Sn0.76Ru |
Type |
A1 Journal article |
Year |
2011 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
Volume |
84 |
Issue |
7 |
Pages |
075152-075152,8 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
We report extensive measurements on a new compound (Yb0.24Sn0.76)Ru that crystallizes in the cubic CsCl structure. Valence-band photoemission (PES) and L3 x-ray absorption show no divalent component in the 4f configuration of Yb. Inelastic neutron scattering (INS) indicates that the eight-fold degenerate J-multiplet of Yb3+ is split by the crystalline electric field (CEF) into a Γ7-doublet ground state and a Γ8 quartet at an excitation energy 20 meV. The magnetic susceptibility can be fit very well by this CEF scheme under the assumption that a Γ6-excited state resides at 32 meV; however, the Γ8/Γ6 transition expected at 12 meV was not observed in the INS. The resistivity follows a Bloch-Grüneisen law shunted by a parallel resistor, as is typical of systems subject to phonon scattering with no apparent magnetic scattering. All of these properties can be understood as representing simple local moment behavior of the trivalent Yb ion. At 1 K there is a peak in specific heat that is too broad to represent a magnetic-phase transition, consistent with absence of magnetic reflections in neutron diffraction. On the other hand this peak also is too narrow to represent the Kondo effect in the Γ7-doublet ground state. On the basis of the field dependence of the specific heat, we argue that antiferromagnetic (AF) short-range order (SRO) (possibly coexisting with Kondo physics) occurs at low temperatures. The long-range magnetic order is suppressed because the Yb site occupancy is below the percolation threshold for this disordered compound. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000293830800003 |
Publication Date |
2011-08-15 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume ![sorted by Series Volume (numeric) field, ascending order (up)](img/sort_asc.gif) |
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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 |
8 |
Open Access |
|
Notes |
Esteem 026019 |
Approved |
Most recent IF: 3.836; 2011 IF: 3.691 |
Call Number |
UA @ lucian @ c:irua:92427 |
Serial |
555 |
Permanent link to this record |
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Author |
Klimczuk, T.; Wang, C.H.; Xu, Q.; Lawrence, J.; Durakiewicz, T.; Ronning, F.; Llobet, A.; Bauer, E.D.; Griveau, J.-C.; Sadowski, W.; Zandbergen, H.W.; Thompson, J.D.; Cava, R.J. |
Title |
Crystal growth of CsCl-type Yb0.24Sn0.76Ru |
Type |
A1 Journal article |
Year |
2011 |
Publication |
Journal of crystal growth |
Abbreviated Journal |
J Cryst Growth |
Volume |
318 |
Issue |
1 |
Pages |
1005-1008 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
The YbRuSn ternary system was investigated and a new material, Yb0.24Sn0.76Ru, with a simple cubic crystal structure, was discovered. Yb0.24Sn0.76Ru has a smaller lattice parameter a=3.217(4) Å, than its isostructural YbRu analogue (a=3.360 Å). Both X-ray diffraction and electron microscopy techniques were used to refine the crystal structure of Yb0.24Sn0.76Ru. It was found that a new compound forms in the CsCl structure, with Ru on the 1a site and a (Yb, Sn) mixture on site 1b. The XRD Rietveld analysis provides the occupation of Yb equal to 0.24, in agreement with the single crystal nano-electron diffraction refinement, which gives the occupation 0.21. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Amsterdam |
Editor |
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Language |
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Wos |
000289653900220 |
Publication Date |
2010-10-26 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume ![sorted by Series Volume (numeric) field, ascending order (up)](img/sort_asc.gif) |
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Series Issue |
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Edition |
|
ISSN |
0022-0248; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
1.751 |
Times cited |
1 |
Open Access |
|
Notes |
Esteem 026019 |
Approved |
Most recent IF: 1.751; 2011 IF: 1.726 |
Call Number |
UA @ lucian @ c:irua:89966 |
Serial |
556 |
Permanent link to this record |
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Author |
Sullivan, E.; Hadermann, J.; Greaves, C. |
Title |
Crystallographic and magnetic characterisation of the brownmillerite Sr2Co2O5 |
Type |
A1 Journal article |
Year |
2011 |
Publication |
Journal of solid state chemistry |
Abbreviated Journal |
J Solid State Chem |
Volume |
184 |
Issue |
3 |
Pages |
649-654 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
Sr2Co2O5 with the perovskite-related brownmillerite structure has been synthesised via quenching, with the orthorhombic unit cell parameters a=5.4639(3) Å, b=15.6486(8) Å and c=5.5667(3) Å based on refinement of neutron powder diffraction data collected at 4 K. Electron microscopy revealed LRLR-intralayer ordering of chain orientations, which require a doubling of the unit cell along the c-parameter, consistent with the assignment of the space group Pcmb. However, on the length scale pertinent to NPD, no long-range order is observed and the disordered space group Imma appears more appropriate. The magnetic structure corresponds to G-type order with a moment of 3.00(4) μB directed along [1 0 0]. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
London |
Editor |
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Language |
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Wos |
000288587800026 |
Publication Date |
2011-01-27 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume ![sorted by Series Volume (numeric) field, ascending order (up)](img/sort_asc.gif) |
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Series Issue |
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Edition |
|
ISSN |
0022-4596; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
2.299 |
Times cited |
19 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 2.299; 2011 IF: 2.159 |
Call Number |
UA @ lucian @ c:irua:89650 |
Serial |
584 |
Permanent link to this record |
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Author |
Corthals, S.; van Noyen, J.; Liang, D.; Ke, X.; Van Tendeloo, G.; Jacobs, P.; Sels, B. |
Title |
A cyclic catalyst pretreatment in CO2 for high yield production of Carbon nanofibers with narrow diameter distribution |
Type |
A1 Journal article |
Year |
2011 |
Publication |
Catalysis letters |
Abbreviated Journal |
Catal Lett |
Volume |
141 |
Issue |
11 |
Pages |
1621-1624 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
This paper presents a cyclic catalyst pretreatment process to improve the CNF yield with narrow size distribution by sequentially feeding the CVD reactor with CH4/CO2 mixtures (carbon deposition) and CO2 (carbon removal) prior to the actual growth process. A mechanism based on a break-up of large Ni particles tentatively explains the beneficial effect of the cyclic carbon deposition/removal CVD procedure. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Basel |
Editor |
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Language |
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Wos |
000296471400006 |
Publication Date |
2011-09-26 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume ![sorted by Series Volume (numeric) field, ascending order (up)](img/sort_asc.gif) |
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Series Issue |
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Edition |
|
ISSN |
1011-372X;1572-879X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
2.799 |
Times cited |
1 |
Open Access |
|
Notes |
Iwt; Iap |
Approved |
Most recent IF: 2.799; 2011 IF: 2.242 |
Call Number |
UA @ lucian @ c:irua:91888 |
Serial |
598 |
Permanent link to this record |
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Author |
Monico, L.; van der Snickt, G.; Janssens, K.; de Nolf, W.; Miliani, C.; Verbeeck, J.; Tian, H.; Tan, H.; Dik, J.; Radepont, M.; Cotte, M. |
Title |
Degradation process of lead chromate in paintings by Vincent van Gogh studied by means of synchrotron X-ray spectromicroscopy and related methods : 1 : artificially aged model samples |
Type |
A1 Journal article |
Year |
2011 |
Publication |
Analytical chemistry |
Abbreviated Journal |
Anal Chem |
Volume |
83 |
Issue |
4 |
Pages |
1214-1223 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT); AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
Abstract |
On several paintings by artists of the end of the 19th century and the beginning of the 20th Century a darkening of the original yellow areas, painted with the chrome yellow pigment (PbCrO4, PbCrO4·xPbSO4, or PbCrO4·xPbO) is observed. The most famous of these are the various Sunflowers paintings Vincent van Gogh made during his career. In the first part of this work, we attempt to elucidate the degradation process of chrome yellow by studying artificially aged model samples. In view of the very thin (1−3 μm) alteration layers that are formed, high lateral resolution spectroscopic methods such as microscopic X-ray absorption near edge (μ-XANES), X-ray fluorescence spectrometry (μ-XRF), and electron energy loss spectrometry (EELS) were employed. Some of these use synchrotron radiation (SR). Additionally, microscopic SR X-ray diffraction (SR μ-XRD), μ-Raman, and mid-FTIR spectroscopy were employed to completely characterize the samples. The formation of Cr(III) compounds at the surface of the chrome yellow paint layers is particularly observed in one aged model sample taken from a historic paint tube (ca. 1914). About two-thirds of the chromium that is present at the surface has reduced from the hexavalent to the trivalent state. The EELS and μ-XANES spectra are consistent with the presence of Cr2O3·2H2O (viridian). Moreover, as demonstrated by μ-XANES, the presence of another Cr(III) compound, such as either Cr2(SO4)3·H2O or (CH3CO2)7Cr3(OH)2 [chromium(III) acetate hydroxide], is likely. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Washington, D.C. |
Editor |
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Language |
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Wos |
000287176900011 |
Publication Date |
2011-02-14 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume ![sorted by Series Volume (numeric) field, ascending order (up)](img/sort_asc.gif) |
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Series Issue |
|
Edition |
|
ISSN |
0003-2700;1520-6882; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
6.32 |
Times cited |
113 |
Open Access |
|
Notes |
Iuap; Fwo |
Approved |
Most recent IF: 6.32; 2011 IF: 5.856 |
Call Number |
UA @ lucian @ c:irua:88794UA @ admin @ c:irua:88794 |
Serial |
632 |
Permanent link to this record |
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Author |
Neyts, E.; Maeyens, A.; Pourtois, G.; Bogaerts, A. |
Title |
A density-functional theory simulation of the formation of Ni-doped fullerenes by ion implantation |
Type |
A1 Journal article |
Year |
2011 |
Publication |
Carbon |
Abbreviated Journal |
Carbon |
Volume |
49 |
Issue |
3 |
Pages |
1013-1017 |
Keywords |
A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
Abstract |
Using self-consistent KohnSham density-functional theory molecular dynamics simulations, we demonstrate the theoretical possibility to synthesize NiC60, the incarfullerene Ni@C60 and the heterofullerene C59Ni in an ion implantation setup. The corresponding formation mechanisms of all three complexes are elucidated as a function of the ion implantation energy and impact location, suggesting possible routes for selectively synthesizing these complexes. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Oxford |
Editor |
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Language |
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Wos |
000286683500032 |
Publication Date |
2010-11-14 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume ![sorted by Series Volume (numeric) field, ascending order (up)](img/sort_asc.gif) |
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Series Issue |
|
Edition |
|
ISSN |
0008-6223; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
6.337 |
Times cited |
13 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 6.337; 2011 IF: 5.378 |
Call Number |
UA @ lucian @ c:irua:85139 |
Serial |
639 |
Permanent link to this record |
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|
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Author |
Philippaerts, A.; Goossens, S.; Vermandel, W.; Tromp, M.; Turner, S.; Geboers, J.; Van Tendeloo, G.; Jacobs, P.A.; Sels, B.F. |
Title |
Design of Ru-zeolites for hydrogen-free production of conjugated linoleic acid |
Type |
A1 Journal article |
Year |
2011 |
Publication |
Chemsuschem |
Abbreviated Journal |
Chemsuschem |
Volume |
4 |
Issue |
6 |
Pages |
757-767 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
While conjugated vegetable oils are currently used as additives in the drying agents of oils and paints, they are also attractive molecules for making bio-plastics. Moreover, conjugated oils will soon be accepted as nutritional additives for functional food products. While current manufacture of conjugated vegetable oils or conjugated linoleic acids (CLAs) uses a homogeneous base as isomerisation catalyst, a heterogeneous alternative is not available today. This contribution presents the direct production of CLAs over Ru supported on different zeolites, varying in topology (ZSM-5, BETA, Y), Si/Al ratio and countercation (H+, Na+, Cs+). Ru/Cs-USY, with a Si/Al ratio of 40, was identified as the most active and selective catalyst for isomerisation of methyl linoleate (cis-9,cis-12 (C18:2)) to CLA at 165 °C. Interestingly, no hydrogen pre-treatment of the catalyst or addition of hydrogen donors is required to achieve industrially relevant isomerisation productivities, namely, 0.7 g of CLA per litre of solvent per minute. Moreover, the biologically most active CLA isomers, namely, cis-9,trans-11, trans-10,cis-12 and trans-9,trans-11, were the main products, especially at low catalyst concentrations. Ex situ physicochemical characterisation with CO chemisorption, extended X-ray absorption fine structure measurements, transmission electron microscopy analysis, and temperature-programmed oxidation reveals the presence of highly dispersed RuO2 species in Ru/Cs-USY(40). |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Weinheim |
Editor |
|
Language |
|
Wos |
000292214000009 |
Publication Date |
2011-04-20 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume ![sorted by Series Volume (numeric) field, ascending order (up)](img/sort_asc.gif) |
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Series Issue |
|
Edition |
|
ISSN |
1864-5631; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
7.226 |
Times cited |
24 |
Open Access |
|
Notes |
Fwo |
Approved |
Most recent IF: 7.226; 2011 IF: 6.827 |
Call Number |
UA @ lucian @ c:irua:90352 |
Serial |
660 |
Permanent link to this record |
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|
|
Author |
Razdobarin, A.G.; Mukhin, E.E.; Semenov, V.V.; Tolstyakov, S.Y.; Kochergin, M.M.; Kurskiev, G.S.; Podushnikova, K.A.; Kirilenko, D.A.; Sitnikova, A.A.; Konovalov, V.G.; Solodovchenko, S.I.; Nekhaieva, O.M.; Skorik, O.A.; Bondarenko, V.N.; Voitsenya, V.S.; |
Title |
Diagnostic mirrors with transparent protection layer for ITER |
Type |
A1 Journal article |
Year |
2011 |
Publication |
Fusion engineering and design |
Abbreviated Journal |
Fusion Eng Des |
Volume |
86 |
Issue |
6-8 |
Pages |
1341-1344 |
Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
Abstract |
Fast degradation of in-vessel optics is one of the most serious problems for all optical diagnostics in ITER. To provide the resistance to mechanical and thermal stresses along with a high stability of optical characteristics under deposition-dominated conditions we suggest using high-reflective metallic (Ag or Al) film mirrors coated on silicon substrate and protected with thin oxide film in the divertor Thomson Scattering (TS) diagnostics. The mirrors coated with Al2O3 and ZrO2 films were tested under irradiation by deuterium ions. The experimental results on the oxide films sputtering are discussed in the context of their applicability for the first mirror protection in ITER. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
Elsevier science sa |
Place of Publication |
Amsterdam |
Editor |
|
Language |
|
Wos |
000297426500203 |
Publication Date |
2011-03-17 |
Series Editor |
|
Series Title |
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Abbreviated Series Title |
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Series Volume ![sorted by Series Volume (numeric) field, ascending order (up)](img/sort_asc.gif) |
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Series Issue |
|
Edition |
|
ISSN |
0920-3796; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
1.319 |
Times cited |
6 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 1.319; 2011 IF: 1.490 |
Call Number |
UA @ lucian @ c:irua:93631 |
Serial |
686 |
Permanent link to this record |
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|
Author |
De Bie, C.; Martens, T.; van Dijk, J.; Paulussen, S.; Verheyde, B.; Corthals, S.; Bogaerts, A. |
Title |
Dielectric barrier discharges used for the conversion of greenhouse gases: modeling the plasma chemistry by fluid simulations |
Type |
A1 Journal article |
Year |
2011 |
Publication |
Plasma sources science and technology |
Abbreviated Journal |
Plasma Sources Sci T |
Volume |
20 |
Issue |
2 |
Pages |
024008,1-024008,11 |
Keywords |
A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
Abstract |
The conversion of methane to value-added chemicals and fuels is considered to be one of the challenges of the 21st century. In this paper we study, by means of fluid modeling, the conversion of methane to higher hydrocarbons or oxygenates by partial oxidation with CO2 or O2 in a dielectric barrier discharge. Sixty-nine different plasma species (electrons, ions, molecules, radicals) are included in the model, as well as a comprehensive set of chemical reactions. The calculation results presented in this paper include the conversion of the reactants and the yields of the reaction products as a function of residence time in the reactor, for different gas mixing ratios. Syngas (i.e. H2 + CO) and higher hydrocarbons (C2Hx) are typically found to be important reaction products. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
Institute of Physics |
Place of Publication |
Bristol |
Editor |
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Language |
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Wos |
000290719900009 |
Publication Date |
2011-04-02 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume ![sorted by Series Volume (numeric) field, ascending order (up)](img/sort_asc.gif) |
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Series Issue |
|
Edition |
|
ISSN |
0963-0252;1361-6595; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
3.302 |
Times cited |
38 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 3.302; 2011 IF: 2.521 |
Call Number |
UA @ lucian @ c:irua:87868 |
Serial |
689 |
Permanent link to this record |
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Author |
Komendová, L.; Milošević, M.V.; Shanenko, A.A.; Peeters, F.M. |
Title |
Different length scales for order parameters in two-gap superconductors : extended Ginzburg-Landau theory |
Type |
A1 Journal article |
Year |
2011 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
Volume |
84 |
Issue |
6 |
Pages |
064522-064522,5 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
Using the Ginzburg-Landau theory extended to the next-to-leading order, we determine numerically the healing lengths of the two order parameters at the two-gap superconductor/normal metal interface. We demonstrate on several examples that those can be different even in the strict domain of applicability of the Ginzburg-Landau theory. This justifies the use of this theory to describe relevant physics of two-gap superconductors, distinguishing them from their single-gap counterparts. The calculational degree of complexity increases only slightly with respect to the conventional Ginzburg-Landau expansion, thus the extended Ginzburg-Landau model remains numerically far less demanding compared to the full microscopic approaches. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000294226000013 |
Publication Date |
2011-08-25 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume ![sorted by Series Volume (numeric) field, ascending order (up)](img/sort_asc.gif) |
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Series Issue |
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Edition |
|
ISSN |
1098-0121;1550-235X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
3.836 |
Times cited |
56 |
Open Access |
|
Notes |
; This work was supported by the Flemish Science Foundation (FWO-Vl), the Belgian Science Policy (IAP), and the ESF-INSTANS network. ; |
Approved |
Most recent IF: 3.836; 2011 IF: 3.691 |
Call Number |
UA @ lucian @ c:irua:92414 |
Serial |
695 |
Permanent link to this record |
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Author |
Tkachenko, D.V.; Sheridan, T.E.; Misko, V.R. |
Title |
Dispersion relations for circular single and double dusty plasma chains |
Type |
A1 Journal article |
Year |
2011 |
Publication |
Physics of plasmas |
Abbreviated Journal |
Phys Plasmas |
Volume |
18 |
Issue |
10 |
Pages |
103709,1-103709,10 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
We derive dispersion relations for a system of identical particles confined in a two-dimensional annular harmonic well and which interact through a Yukawa potential, e.g., a dusty plasma ring. When the particles are in a single chain (i.e., a one-dimensional ring), we find a longitudinal acoustic mode and a transverse optical mode which show approximate agreement with the dispersion relation for a straight configuration for large radii of the ring. When the radius decreases, the dispersion relations modify: there appears an anticrossing of the modes near the crossing point resulting in a frequency gap between the lower and upper branches of the modified dispersion relations. For the double chain (i.e., a two-dimensional zigzag configuration), the dispersion relation has four branches: longitudinal acoustic and optical and transverse acoustic and optical. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Woodbury, N.Y. |
Editor |
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Language |
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Wos |
000296529600090 |
Publication Date |
2011-10-21 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume ![sorted by Series Volume (numeric) field, ascending order (up)](img/sort_asc.gif) |
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Series Issue |
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Edition |
|
ISSN |
1070-664X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
2.115 |
Times cited |
7 |
Open Access |
|
Notes |
; We acknowledge fruitful discussions with F.M. Peeters, A. Matulis, and W.P. Ferreira. This work was supported by the “Odysseus” program of the Flemish Government and FWO-Vl. ; |
Approved |
Most recent IF: 2.115; 2011 IF: 2.147 |
Call Number |
UA @ lucian @ c:irua:94052 |
Serial |
738 |
Permanent link to this record |
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Author |
Khaydarov, R.T.; Beisinbaeva, H.B.; Sabitov, M.M.; Kalal, M.; Berdiyorov, G.R. |
Title |
Effect of light gas atom inclusions on the characteristics of laser-produced plasma ions |
Type |
A1 Journal article |
Year |
2011 |
Publication |
Nuclear fusion |
Abbreviated Journal |
Nucl Fusion |
Volume |
51 |
Issue |
10 |
Pages |
103041,1-103041,3 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
Using the mass-spectrometric method we studied the effect of light gas inclusions on the formation process of multi-component laser-induced plasma ions. Masscharge characteristics, as well as energy and spatial distribution of the plasma ions are analysed. We found that both the energy and maximal charge of heavy component ions decrease due to the presence of gas atoms in the solid target surface layer. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Vienna |
Editor |
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Language |
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Wos |
000296603800043 |
Publication Date |
2011-09-23 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume ![sorted by Series Volume (numeric) field, ascending order (up)](img/sort_asc.gif) |
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Series Issue |
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Edition |
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ISSN |
0029-5515;1741-4326; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
3.307 |
Times cited |
1 |
Open Access |
|
Notes |
; ; |
Approved |
Most recent IF: 3.307; 2011 IF: 4.090 |
Call Number |
UA @ lucian @ c:irua:93761 |
Serial |
821 |
Permanent link to this record |
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Author |
Khalil-Allafi, J.; Amin-Ahmadi, B. |
Title |
Effect of mold hardness on microstructure and contraction porosity in ductile cast iron |
Type |
A1 Journal article |
Year |
2011 |
Publication |
Journal of iron and steel research international |
Abbreviated Journal |
J Iron Steel Res Int |
Volume |
18 |
Issue |
4 |
Pages |
44-47 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
The effect of mold hardness on the microstructure of ductile iron and the contraction porosity was investigated. Molds with different hardnesses (0.41, 0.48, 0.55, 0.62 MPa) and a sand mold prepared by Co2 method were used. The influence of silicon content on the induced expansion pressure owing to the formation of graphite was also investigated. The contraction during solidification can be compensated by an induced expansion owing to the graphite relief when the hardness of mold increases; therefore, the possibility of achieving a sound product without using any riser increases. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
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Publication Date |
2011-05-01 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume ![sorted by Series Volume (numeric) field, ascending order (up)](img/sort_asc.gif) |
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Series Issue |
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Edition |
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ISSN |
1006-706X; |
ISBN |
|
Additional Links |
UA library record |
Impact Factor |
0.836 |
Times cited |
1 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 0.836; 2011 IF: 0.213 |
Call Number |
UA @ lucian @ c:irua:122044 |
Serial |
823 |
Permanent link to this record |
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Author |
Hezareh, T.; Razavi, F.S.; Kremer, R.K.; Habermeier, H.-U.; Lebedev, O.I.; Kirilenko, D.; Van Tendeloo, G. |
Title |
Effect of PbZr0.52Ti0.48O3 thin layer on structure, electronic and magnetic properties of La0.65Sr0.35MnO3 and La0.65Ca0.30MnO3 thin-films |
Type |
A1 Journal article |
Year |
2011 |
Publication |
Journal of applied physics |
Abbreviated Journal |
J Appl Phys |
Volume |
109 |
Issue |
11 |
Pages |
113707,1-113707,8 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
Epitaxial thin film heterostructures of high dielectric PbZr<sub>1-x</sub>Ti<sub>x</sub>O<sub>3</sub> (PZT) and La<sub>1-x</sub>A<sub>x</sub>MnO<sub>3</sub> (A-divalent alkaline earth metals such as Sr (LSMO) and Ca (LCMO)) were grown on SrTiO<sub>3</sub> substrates and their structure, temperature dependence of electrical resistivity, and magnetization were investigated as a function of the thickness of the LSMO(LCMO) layer. The microstructures of the samples were analyzed by TEM. By applying an electric field across the PZT layer, we applied a ferrodistortive pressure on the manganite layer and studied the correlations between lattice distortion and electric transport and magnetic properties of the CMR materials. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
American Institute of Physics |
Place of Publication |
New York, N.Y. |
Editor |
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Language |
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Wos |
000292214700069 |
Publication Date |
2011-06-06 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume ![sorted by Series Volume (numeric) field, ascending order (up)](img/sort_asc.gif) |
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Series Issue |
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Edition |
|
ISSN |
0021-8979; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
2.068 |
Times cited |
4 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 2.068; 2011 IF: 2.168 |
Call Number |
UA @ lucian @ c:irua:90964 |
Serial |
843 |
Permanent link to this record |
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Author |
De Backer, L.; Vos, W.; Dieriks, B.; Daems, D.; Verhulst, S.; Vinchurkar, S.; Ides, K.; de Backer, J.; Germonpré, P.; de Backer, W. |
Title |
The effects of long-term noninvasive ventilation in hypercapnic COPD patients : a randomized controlled pilot study |
Type |
A1 Journal article |
Year |
2011 |
Publication |
International journal of chronic obstructive pulmonary disease |
Abbreviated Journal |
Int J Chronic Obstr |
Volume |
6 |
Issue |
|
Pages |
615-624 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT); Laboratory Experimental Medicine and Pediatrics (LEMP) |
Abstract |
Introduction: Noninvasive ventilation (NIV) is a well-established treatment for acute-on-chronic respiratory failure in hypercapnic COPD patients. Less is known about the effects of a long-term treatment with NIV in hypercapnic COPD patients and about the factors that may predict response in terms of improved oxygenation and lowered CO2 retention.Methods: In this study, we randomized 15 patients to a routine pharmacological treatment (n = 5, age 66 [standard deviation ± 6] years, FEV1 30.5 [±5.1] %pred, PaO2 65 [±6] mmHg, PaCO2 52.4 [±6.0] mmHg) or to a routine treatment and NIV (using the Synchrony BiPAP device [Respironics, Inc, Murrsville, PA]) (n = 10, age 65 [±7] years, FEV1 29.5 [±9.0] %pred, PaO2 59 [±13] mmHg, PaCO2 55.4 [±7.7] mmHg) for 6 months. We looked at arterial blood gasses, lung function parameters and performed a low-dose computed tomography of the thorax, which was later used for segmentation (providing lobe and airway volumes, iVlobe and iVaw) and post-processing with computer methods (providing airway resistance, iRaw) giving overall a functional image of the separate airways and lobes.Results: In both groups there was a nonsignificant change in FEV1 (NIV group 29.5 [9.0] to 38.5 [14.6] %pred, control group 30.5 [5.1] to 36.8 [8.7] mmHg). PaCO2 dropped significantly only in the NIV group (NIV: 55.4 [7.7] → 44.5 [4.70], P = 0.0076; control: 52.4 [6.0] → 47.6 [8.2], NS). Patients actively treated with NIV developed a more inhomogeneous redistribution of mass flow than control patients. Subsequent analysis indicated that in NIV-treated patients that improve their blood gases, mass flow was also redistributed towards areas with higher vessel density and less emphysema, indicating that flow was redistributed towards areas with better perfusion. There was a highly significant correlation between the % increase in mass flow towards lobes with a blood vessel density of >9% and the increase in PaO2. Improved ventilation–perfusion match and recruitment of previously occluded small airways can explain the improvement in blood gases.Conclusion: We can conclude that in hypercapnic COPD patients treated with long-term NIV over 6 months, a mass flow redistribution occurs, providing a better ventilation–perfusion match and hence better blood gases and lung function. Control patients improve homogeneously in iVaw and iRaw, without improvement in gas exchange since there is no improved ventilation/perfusion ratio or increased alveolar ventilation. These differences in response can be detected through functional imaging, which gives a more detailed report on regional lung volumes and resistances than classical lung function tests do. Possibly only patients with localized small airway disease are good candidates for long-term NIV treatment. To confirm this and to see if better arterial blood gases also lead to better health related quality of life and longer survival, we have to study a larger population. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000208709800066 |
Publication Date |
2011-11-18 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume ![sorted by Series Volume (numeric) field, ascending order (up)](img/sort_asc.gif) |
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Series Issue |
|
Edition |
|
ISSN |
1178-2005; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
3.157 |
Times cited |
28 |
Open Access |
|
Notes |
; ; |
Approved |
Most recent IF: 3.157; 2011 IF: NA |
Call Number |
UA @ lucian @ c:irua:93164 |
Serial |
866 |
Permanent link to this record |
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|
Author |
Sofo, J.O.; Suarez, A.M.; Usaj, G.; Cornaglia, P.S.; Hernández-Nieves, A.D.; Balseiro, C.A. |
Title |
Electrical control of the chemical bonding of fluorine on graphene |
Type |
A1 Journal article |
Year |
2011 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
Volume |
83 |
Issue |
8 |
Pages |
081411 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
We study the electronic structure of diluted F atoms chemisorbed on graphene using density functional theory calculations. We show that the nature of the chemical bonding of a F atom adsorbed on top of a C atom in graphene strongly depends on carrier doping. In neutral samples the F impurities induce a sp(3)-like bonding of the C atom below, generating a local distortion of the hexagonal lattice. As the graphene is electron-doped, the C atom retracts back to the graphene plane and for high doping (10(14) cm(-2)) its electronic structure corresponds to a nearly pure sp(2) configuration. We interpret this sp(3)-sp(2) doping-induced crossover in terms of a simple tight-binding model and discuss the physical consequences of this change. |
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Place of Publication |
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Wos |
000287484800005 |
Publication Date |
2011-02-18 |
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Abbreviated Series Title |
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Series Volume ![sorted by Series Volume (numeric) field, ascending order (up)](img/sort_asc.gif) |
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Series Issue |
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Edition |
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ISSN |
1098-0121;1550-235X; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
3.836 |
Times cited |
65 |
Open Access |
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Notes |
; J.O.S. and A. S. acknowledge support from the Donors of the American Chemical Society Petroleum Research Fund and use of facilities at the Penn State Materials Simulation Center. G. U., P. S. C., A. D. H., and C. A. B. acknowledge financial support from PICTs 06-483 and 2008-2236 from ANPCyT and PIP 11220080101821 from CONICET, Argentina. A. D. H. acknowledges support from the Flemish Science Foundation (FWO). ; |
Approved |
Most recent IF: 3.836; 2011 IF: 3.691 |
Call Number |
UA @ lucian @ c:irua:105600 |
Serial |
892 |
Permanent link to this record |
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Author |
Grujić, M.; Zarenia, M.; Chaves, A.; Tadić, M.; Farias, G.A.; Peeters, F.M. |
Title |
Electronic and optical properties of a circular graphene quantum dot in a magnetic field : influence of the boundary conditions |
Type |
A1 Journal article |
Year |
2011 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
Volume |
84 |
Issue |
20 |
Pages |
205441-205441,12 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
An analytical approach, using the Dirac-Weyl equation, is implemented to obtain the energy spectrum and optical absorption of a circular graphene quantum dot in the presence of an external magnetic field. Results are obtained for the infinite-massand zigzag boundary conditions. We found that the energy spectrum of a dot with the zigzag boundary condition exhibits a zero-energy band regardless of the value of the magnetic field, while for the infinite-mass boundary condition, the zero-energy states appear only for high magnetic fields. The analytical results are compared to those obtained from the tight-binding model: (i) we show the validity range of the continuum model and (ii) we find that the continuum model with the infinite-mass boundary condition describes rather well its tight-binding analog, which can be partially attributed to the blurring of the mixed edges by the staggered potential. |
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Wos |
000297295400011 |
Publication Date |
2011-11-21 |
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Series Volume ![sorted by Series Volume (numeric) field, ascending order (up)](img/sort_asc.gif) |
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Series Issue |
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Edition |
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ISSN |
1098-0121;1550-235X; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
3.836 |
Times cited |
78 |
Open Access |
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Notes |
; This work was supported by the EuroGraphene programme of the ESF (project CONGRAN), the Ministry of Education and Science of Serbia, the Belgian Science Policy (IAP), the bilateral projects between Flanders and Brazil, the Flemish Science Foundation (FWO-Vl), and the Brazilian Research Council (CNPq). ; |
Approved |
Most recent IF: 3.836; 2011 IF: 3.691 |
Call Number |
UA @ lucian @ c:irua:94025 |
Serial |
997 |
Permanent link to this record |
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Author |
Houssa, M.; Scalise, E.; Sankaran, K.; Pourtois, G.; Afanas'ev, V.V.; Stesmans, A. |
Title |
Electronic properties of hydrogenated silicene and germanene |
Type |
A1 Journal article |
Year |
2011 |
Publication |
Applied physics letters |
Abbreviated Journal |
Appl Phys Lett |
Volume |
98 |
Issue |
22 |
Pages |
223107 |
Keywords |
A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
Abstract |
The electronic properties of hydrogenated silicene and germanene, so called silicane and germanane, respectively, are investigated using first-principles calculations based on density functional theory. Two different atomic configurations are found to be stable and energetically degenerate. Upon the adsorption of hydrogen, an energy gap opens in silicene and germanene. Their energy gaps are next computed using the HSE hybrid functional as well as the G(0)W(0) many-body perturbation method. These materials are found to be wide band-gap semiconductors, the type of gap in silicane (direct or indirect) depending on its atomic configuration. Germanane is predicted to be a direct-gap material, independent of its atomic configuration, with an average energy gap of about 3.2 eV, this material thus being potentially interesting for optoelectronic applications in the blue/violet spectral range. (C) 2011 American Institute of Physics. [doi: 10.1063/1.3595682] |
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Corporate Author |
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Thesis |
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Publisher |
American Institute of Physics |
Place of Publication |
New York, N.Y. |
Editor |
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Language |
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Wos |
000291405700057 |
Publication Date |
2011-06-03 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume ![sorted by Series Volume (numeric) field, ascending order (up)](img/sort_asc.gif) |
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Series Issue |
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Edition |
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ISSN |
0003-6951; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
3.411 |
Times cited |
63 |
Open Access |
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Notes |
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Approved |
Most recent IF: 3.411; 2011 IF: 3.844 |
Call Number |
UA @ lucian @ c:irua:105586 |
Serial |
1003 |
Permanent link to this record |
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Author |
Dixit, H.; Tandon, N.; Cottenier, S.; Saniz, R.; Lamoen, D.; Partoens, B.; van Speybroeck, V.; Waroquier, M. |
Title |
Electronic structure and band gap of zinc spinel oxides beyond LDA : ZnAl2O4, ZnGa2O4 and ZnIn2O4 |
Type |
A1 Journal article |
Year |
2011 |
Publication |
New journal of physics |
Abbreviated Journal |
New J Phys |
Volume |
13 |
Issue |
6 |
Pages |
063002-063002,11 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT) |
Abstract |
We examine the electronic structure of the family of ternary zinc spinel oxides ZnX2O4 (X=Al, Ga and In). The band gap of ZnAl2O4 calculated using density functional theory (DFT) is 4.25 eV and is overestimated compared with the experimental value of 3.83.9 eV. The DFT band gap of ZnGa2O4 is 2.82 eV and is underestimated compared with the experimental value of 4.45.0 eV. Since DFT typically underestimates the band gap in the oxide system, the experimental measurements for ZnAl2O4 probably require a correction. We use two first-principles techniques capable of describing accurately the excited states of semiconductors, namely the GW approximation and the modified BeckeJohnson (MBJ) potential approximation, to calculate the band gap of ZnX2O4. The GW and MBJ band gaps are in good agreement with each other. In the case of ZnAl2O4, the predicted band gap values are >6 eV, i.e. ~2 eV larger than the only reported experimental value. We expect future experimental work to confirm our results. Our calculations of the electron effective masses and the second band gap indicate that these compounds are very good candidates to act as transparent conducting host materials. |
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Thesis |
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Publisher |
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Place of Publication |
Bristol |
Editor |
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Language |
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Wos |
000292137500002 |
Publication Date |
2011-06-03 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume ![sorted by Series Volume (numeric) field, ascending order (up)](img/sort_asc.gif) |
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Series Issue |
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Edition |
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ISSN |
1367-2630; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
3.786 |
Times cited |
98 |
Open Access |
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Notes |
Iwt; Fwo; Bof-Noi |
Approved |
Most recent IF: 3.786; 2011 IF: 4.177 |
Call Number |
UA @ lucian @ c:irua:89555 |
Serial |
1008 |
Permanent link to this record |
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Author |
Yusupov, M.; Bultinck, E.; Depla, D.; Bogaerts, A. |
Title |
Elucidating the asymmetric behavior of the discharge in a dual magnetron sputter deposition system |
Type |
A1 Journal article |
Year |
2011 |
Publication |
Applied physics letters |
Abbreviated Journal |
Appl Phys Lett |
Volume |
98 |
Issue |
13 |
Pages |
131502-131502,3 |
Keywords |
A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
Abstract |
A magnetron discharge is characterized by drifts of the charged particles guiding center, caused by the magnetic field, in contrast to unmagnetized discharges. Because of these drifts, a pronounced asymmetry of the discharge can be observed in a dual magnetron setup. In this work, it is found that the shape of the discharge in a dual magnetron configuration depends on the magnetic field configuration. In a closed configuration, strong drifts were observed in one preferential direction, whereas in a mirror configuration the deflection of the discharge was not so pronounced. Our calculations confirm experimental observations. |
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Publisher |
American Institute of Physics |
Place of Publication |
New York, N.Y. |
Editor |
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Wos |
000289153600017 |
Publication Date |
2011-04-01 |
Series Editor |
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Abbreviated Series Title |
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Series Volume ![sorted by Series Volume (numeric) field, ascending order (up)](img/sort_asc.gif) |
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Series Issue |
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Edition |
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ISSN |
0003-6951; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
3.411 |
Times cited |
4 |
Open Access |
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Notes |
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Approved |
Most recent IF: 3.411; 2011 IF: 3.844 |
Call Number |
UA @ lucian @ c:irua:87867 |
Serial |
1026 |
Permanent link to this record |
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Author |
Zarenia, M.; Chaves, A.; Farias, G.A.; Peeters, F.M. |
Title |
Energy levels of triangular and hexagonal graphene quantum dots : a comparative study between the tight-binding and Dirac equation approach |
Type |
A1 Journal article |
Year |
2011 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
Volume |
84 |
Issue |
24 |
Pages |
245403-245403,12 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
The Dirac equation is solved for triangular and hexagonal graphene quantum dots for different boundary conditions in the presence of a perpendicular magnetic field. We analyze the influence of the dot size and its geometry on their energy spectrum. A comparison between the results obtained for graphene dots with zigzag and armchair edges, as well as for infinite-mass boundary condition, is presented and our results show that the type of graphene dot edge and the choice of the appropriate boundary conditions have a very important influence on the energy spectrum. The single-particle energy levels are calculated as a function of an external perpendicular magnetic field that lifts degeneracies. Comparing the energy spectra obtained from the tight-binding approximation to those obtained from the continuum Dirac equation approach, we verify that the behavior of the energies as a function of the dot size or the applied magnetic field are qualitatively similar, but in some cases quantitative differences can exist. |
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Wos |
000297767800008 |
Publication Date |
2011-12-07 |
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Series Volume ![sorted by Series Volume (numeric) field, ascending order (up)](img/sort_asc.gif) |
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Series Issue |
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Edition |
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ISSN |
1098-0121;1550-235X; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
3.836 |
Times cited |
145 |
Open Access |
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Notes |
; This work was supported by the Flemish Science Foundation (FWO-Vl), the Belgian Science Policy (IAP), the European Science Foundation (ESF) under the EUROCORES Program EuroGRAPHENE (project CONGRAN), the Bilateral program between Flanders and Brazil, CAPES and the Brazilian Council for Research (CNPq). ; |
Approved |
Most recent IF: 3.836; 2011 IF: 3.691 |
Call Number |
UA @ lucian @ c:irua:93961 |
Serial |
1040 |
Permanent link to this record |
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Author |
Saniz, R.; Barbiellini, B.; Denison, A.B.; Bansil, A. |
Title |
Erratum: Spontaneous magnetization and electron momentum density in three-dimensional quantum dots [Phys. Rev. B 68, 165326 (2003)] |
Type |
A1 Journal article |
Year |
2011 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
Volume |
84 |
Issue |
11 |
Pages |
119907 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Language |
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Wos |
000295263600015 |
Publication Date |
2011-09-28 |
Series Editor |
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Abbreviated Series Title |
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Series Volume ![sorted by Series Volume (numeric) field, ascending order (up)](img/sort_asc.gif) |
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Series Issue |
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Edition |
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ISSN |
1098-0121;1550-235X; |
ISBN |
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Additional Links |
UA library record; WoS full record |
Impact Factor |
3.836 |
Times cited |
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Open Access |
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Notes |
; ; |
Approved |
Most recent IF: 3.836; 2011 IF: 3.691 |
Call Number |
UA @ lucian @ c:irua:92919 |
Serial |
1081 |
Permanent link to this record |
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Author |
Tadić, M.; Čukarić, N.; Arsoski, V.; Peeters, F.M. |
Title |
Excitonic Aharonov-Bohm effect : unstrained versus strained type-I semiconductor nanorings |
Type |
A1 Journal article |
Year |
2011 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
Volume |
84 |
Issue |
12 |
Pages |
125307-125307,13 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
We study how mechanical strain affects the magnetic field dependence of the exciton states in type-I semiconductor nanorings. Strain spatially separates the electron and hole in (In,Ga)As/GaAs nanorings which is beneficial for the occurrence of the excitonic Aharonov-Bohm (AB) effect. In narrow strained (In,Ga)As/GaAs nanorings the AB oscillations in the exciton ground-state energy are due to anticrossings with the first excited state. No such AB oscillations are found in unstrained GaAs/(Al,Ga)As nanorings irrespective of the ring width. Our results are obtained within an exact numerical diagonalization scheme and are shown to be accurately described by a two-level model with off-diagonal coupling t. The later transfer integral expresses the Coulomb coupling between states of electron-hole pairs. We also found that the oscillator strength for exciton recombination in (In,Ga)As/GaAs nanorings exhibits AB oscillations, which are superimposed on a linear increase with magnetic field. Our results agree qualitatively with recent experiments on the excitonic Aharonov-Bohm effect in type-I (In,Ga)As/GaAs nanorings. |
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Place of Publication |
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Language |
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Wos |
000294777400013 |
Publication Date |
2011-09-09 |
Series Editor |
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Abbreviated Series Title |
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Series Volume ![sorted by Series Volume (numeric) field, ascending order (up)](img/sort_asc.gif) |
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Series Issue |
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Edition |
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ISSN |
1098-0121;1550-235X; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
3.836 |
Times cited |
13 |
Open Access |
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Notes |
; This work was supported by the Ministry of Education and Science of Serbia, the Flemish Science Foundation (FWO-Vl), the EU NoE: SANDiE, and the Belgian Science Policy (IAP). The calculations were performed on the CalcUA and Seastar computer clusters of the University of Antwerp. ; |
Approved |
Most recent IF: 3.836; 2011 IF: 3.691 |
Call Number |
UA @ lucian @ c:irua:92326 |
Serial |
1122 |
Permanent link to this record |