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Author Houssa, M.; Pourtois, G.; Afanas'ev, V.V.; Stesmans, A.
Title Electronic properties of two-dimensional hexagonal germanium Type A1 Journal article
Year 2010 Publication Applied physics letters Abbreviated Journal Appl Phys Lett
Volume 96 Issue 8 Pages 082111,1-082111,3
Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract The electronic properties of two-dimensional hexagonal germanium, so called germanene, are investigated using first-principles simulations. Consistent with previous reports, the surface is predicted to have a poor metallic behavior, i.e., being metallic with a low density of states at the Fermi level. It is found that biaxial compressively strained germanene is a gapless semiconductor with linear energy dispersions near the K pointslike graphene. The calculated Fermi velocity of germanene is almost independent of the strain and is about 1.7×10<sup>6</sup> m/s, quite comparable to the value in graphene.
Address
Corporate Author Thesis
Publisher American Institute of Physics Place of Publication New York, N.Y. Editor
Language Wos 000275027200044 Publication Date 2010-02-25
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0003-6951; ISBN Additional Links (up) UA library record; WoS full record; WoS citing articles
Impact Factor 3.411 Times cited 86 Open Access
Notes Approved Most recent IF: 3.411; 2010 IF: 3.841
Call Number UA @ lucian @ c:irua:91716 Serial 1004
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Author Horemans, B.; Cardell, C.; Bencs, L.; Kontozova-Deutsch, V.; De Wael, K.; Van Grieken, R.
Title Evaluation of airborne particles at the Alhambra monument in Granada, Spain Type A1 Journal article
Year 2011 Publication Microchemical journal Abbreviated Journal Microchem J
Volume 99 Issue 2 Pages 429-438
Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Abstract As a part of an ongoing investigation regarding the air quality at the Alhambra monument (UNESCO World Cultural Heritage), indoor and outdoor atmospheric aerosols (PM1 and PM10-1) and pollutant gases (O3, NO2, SO2 and NH3) were studied during summer and winter. Bulk elements, ionic compounds and black carbon (BC) in aerosols were analyzed with X-ray fluorescence spectrometry, ion chromatography and aethalometry/reflectometry, respectively. Natural PM10-1 aerosols, such as carbonate-rich soil and sea salts, reacted with a typical urban atmosphere, producing a mixture of particulates with diverse chemical composition. The content/formation of secondary inorganic aerosols depended on the air temperature and absolute humidity. Ratios of typical mineral elements (i.e., Ti/Fe and Si/Fe) showed that Saharan dust events contribute to the composition of the observed mineral aerosol content. BC, V and Ni originated from diesel exhaust, while Cu, Cr, Pb and Zn came mainly from non-exhaust vehicular emissions. Weathering phenomena, such as blackening and pigment discoloration, which could arise from gradual aerosol deposition indoors, are discussed.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000295770700042 Publication Date 2011-06-28
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0026-265x; 0026-265x ISBN Additional Links (up) UA library record; WoS full record; WoS citing articles
Impact Factor 3.034 Times cited 39 Open Access
Notes ; ; Approved Most recent IF: 3.034; 2011 IF: 3.048
Call Number UA @ admin @ c:irua:91720 Serial 5611
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Author György, K.; Ajtony, Z.; van Meel, K.; Van Grieken, R.; Czitrovszky, A.; Bencs, L.
Title Fast heating induced impulse halogenation of refractory sample components in electrothermal atomic absorption spectrometry by direct injection of a liquid halogenating agent Type A1 Journal article
Year 2011 Publication Talanta : the international journal of pure and applied analytical chemistry Abbreviated Journal
Volume 85 Issue 3 Pages 1253-1259
Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Abstract A novel electrothermal atomic absorption spectrometry (ETAAS) method was developed for the halogenation of refractory sample components (Er, Nd and Nb) of lithium niobate (LiNbO3) and bismuth tellurite (Bi2TeO5) optical single crystals to overcome memory effects and carry-over. For this purpose, the cleaning step of a regular graphite furnace heating program was replaced with a halogenation cycle. In this cycle, after the graphite tube cooled to room temperature, a 20 μL aliquot of liquid carbon tetrachloride (CCl4) was dispensed with a conventional autosampler into the graphite tube. The CCl4 was partially dried at 80 °C under the mini-flow (40 cm3 min−1) condition of the Ar internal furnace gas (IFG), then the residue was decomposed (pyrolyzed) by fast furnace heating at 19002100 °C under interrupted flow of the IFG. This step was followed by a clean-out stage at 2100 °C under the maximum flow of the IFG. The advantage of the present method is that it does not require any alteration to the graphite furnace gas supply system in contrast to most of the formerly introduced halogenation techniques. The effectiveness of the halogenation method was verified with the determination of Er and Nd dopants in the optical crystals. In these analyses, a sensitivity decrease was observed, which was likely due to the enhanced deterioration of the graphite tube surface. Therefore, the application of mathematical correction (resloping) of the calibration was also required. The calibration curves were linear up to 1.5 and 10 μmol L−1 for Er and Nd, respectively. Characteristic masses of 18 and 241 pg and the limit of detection (LOD) values of 0.017 and 0.27 μmol L−1 were found for Er and Nd, respectively. These LOD data correspond to 0.68 μmol mol−1 Er and 11 μmol mol−1 Nd in solid bismuth tellurite samples. The analytical results were compared with those obtained by a conventional ETAAS method and validated with X-ray fluorescence spectrometry analysis.
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000294092800006 Publication Date 2011-05-27
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0039-9140; 1873-3573 ISBN Additional Links (up) UA library record; WoS full record; WoS citing articles
Impact Factor Times cited Open Access
Notes Approved no
Call Number UA @ admin @ c:irua:91721 Serial 7960
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Author Glazov, M.M.; Semina, M.A.; Badalyan, S.M.; Vignale, G.
Title Spin-current generation from Coulomb-Rashba interaction in semiconductor bilayers 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 033305-033305,4
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract Electrons in double-layer semiconductor heterostructures experience a special type of spin-orbit interaction that arises in each layer from the perpendicular component of the Coulomb electric field created by electron-density fluctuations in the other layer. We show that this interaction, acting in combination with the usual spin-orbit interaction, can generate a spin current in one layer when a charge current is driven in the other. This effect is distinct symmetrywise from the spin-Hall drag. The spin current is not, in general, perpendicular to the drive current.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000293129200001 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 (up) UA library record; WoS full record; WoS citing articles
Impact Factor 3.836 Times cited 5 Open Access
Notes ; M.M.G. and M. A. S. are grateful to RFBR, EU projects Spinoptronics and POLAPHEN, and the “Dynasty” Foundation-ICFPM for financial support. S. M. B. acknowledges support from EU Grant No. PIIF-GA-2009-235394, the DFG SFB 689, and the Belgium Science Policy (IAP). G. V. acknowledges support from NSF Grant No. DMR-0705460. ; Approved Most recent IF: 3.836; 2011 IF: 3.691
Call Number UA @ lucian @ c:irua:91740 Serial 3081
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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.
Address
Corporate Author Thesis
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 (up) 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 Zarenia, M.; Pereira, J.M.; Peeters, F.M.; Farias, G. de A.
Title Topological confinement in an antisymmetric potential in bilayer graphene in the presence of a magnetic field Type A1 Journal article
Year 2011 Publication Nanoscale research letters Abbreviated Journal Nanoscale Res Lett
Volume 6 Issue Pages 452,1-452,10
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract We investigate the effect of an external magnetic field on the carrier states that are localized at a potential kink and a kink-antikink in bilayer graphene. These chiral states are localized at the interface between two potential regions with opposite signs.
Address
Corporate Author Thesis
Publisher Place of Publication New York, N.Y. Editor
Language Wos 000293299800001 Publication Date 2011-07-14
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1556-276X; ISBN Additional Links (up) UA library record; WoS full record; WoS citing articles
Impact Factor 2.833 Times cited 4 Open Access
Notes ; This work was supported by the Brazilian agency CNPq (Pronex), the Flemish Science Foundation (FWO-Vl), the Belgian Science Policy (IAP), and the bilateral projects between Flanders and Brazil and FWO-CNPq. ; Approved Most recent IF: 2.833; 2011 IF: NA
Call Number UA @ lucian @ c:irua:91745 Serial 3674
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Author Mao, M.; Wang, Y.N.; Bogaerts, A.
Title Numerical study of the plasma chemistry in inductively coupled SF6 and SF6/AR plasmas used for deep silicon etching applications Type A1 Journal article
Year 2011 Publication Journal of physics: D: applied physics Abbreviated Journal J Phys D Appl Phys
Volume 44 Issue 43 Pages 435202,1-435202,15
Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract A hybrid model, called the hybrid plasma equipment model, was used to study inductively coupled SF6 plasmas used for Si etching applications. The plasma properties such as number densities of electrons, positive and negative ions, and neutrals are calculated under typical etching conditions. The electron kinetics is analysed by means of the electron energy probability function. The plasma chemistry taking place in pure SF6 and in an Ar/SF6 mixture is also discussed, and finally the effect of the argon fraction on the plasma properties is investigated.
Address
Corporate Author Thesis
Publisher Place of Publication London Editor
Language Wos 000296591100004 Publication Date 2011-10-13
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0022-3727;1361-6463; ISBN Additional Links (up) UA library record; WoS full record; WoS citing articles
Impact Factor 2.588 Times cited 20 Open Access
Notes Approved Most recent IF: 2.588; 2011 IF: 2.544
Call Number UA @ lucian @ c:irua:91754 Serial 2409
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Author Tsirlin, A.A.; Nath, R.; Abakumov, A.M.; Furukawa, Y.; Johnston, D.C.; Hemmida, M.; Krug von Nidda, H.-A.; Loidl, A.; Geibel, C.; Rosner, H.
Title Phase separation and frustrated square lattice magnetism of Na1.5VOPO4F0.5 Type A1 Journal article
Year 2011 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B
Volume 84 Issue 1 Pages 014429-014429,16
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Crystal structure, electronic structure, and magnetic behavior of the spin-1/2 quantum magnet Na1.5VOPO4F0.5 are reported. The disorder of Na atoms leads to a sequence of structural phase transitions revealed by synchrotron x-ray powder diffraction and electron diffraction. The high-temperature second-order α↔β transition at 500 K is of the order-disorder type, whereas the low-temperature β↔γ+γ′ transition around 250 K is of the first order and leads to a phase separation toward the polymorphs with long-range (γ) and short-range (γ′) order of Na. Despite the complex structural changes, the magnetic behavior of Na1.5VOPO4F0.5 probed by magnetic susceptibility, heat capacity, and electron spin resonance measurements is well described by the regular frustrated square lattice model of the high-temperature α-polymorph. The averaged nearest-neighbor and next-nearest-neighbor couplings are J̅ 1≃−3.7 K and J̅ 2≃6.6 K, respectively. Nuclear magnetic resonance further reveals the long-range ordering at TN=2.6 K in low magnetic fields. Although the experimental data are consistent with the simplified square-lattice description, band structure calculations suggest that the ordering of Na atoms introduces a large number of inequivalent exchange couplings that split the square lattice into plaquettes. Additionally, the direct connection between the vanadium polyhedra induces an unusually strong interlayer coupling having effect on the transition entropy and the transition anomaly in the specific heat. Peculiar features of the low-temperature crystal structure and the relation to isostructural materials suggest Na1.5VOPO4F0.5 as a parent compound for the experimental study of tetramerized square lattices as well as frustrated square lattices with different values of spin.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000293247400008 Publication Date 2011-07-28
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1098-0121;1550-235X; ISBN Additional Links (up) UA library record; WoS full record; WoS citing articles
Impact Factor 3.836 Times cited 47 Open Access
Notes Approved Most recent IF: 3.836; 2011 IF: 3.691
Call Number UA @ lucian @ c:irua:91770 Serial 2588
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Author Tognalii, N.G.; Cortés, E.; Hernández-Nieves, A.D.; Carro, P.; Usaj, G.; Balseiro, C.A.; Vela, M.E.; Salvarezza, R.C.; Fainstein, A.
Title From single to multiple Ag-layer modification of Au nanocavity substrates : a tunable probe of the chemical surface-enhanced Raman scattering mechanism Type A1 Journal article
Year 2011 Publication ACS nano Abbreviated Journal Acs Nano
Volume 5 Issue 7 Pages 5433-5443
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract We present experimental and computational results that enlighten the mechanisms underlying the chemical contribution to surface-enhanced Raman scattering (SERS). Gold void metallic arrays electrochemically covered either by a Ag monolayer or 10100 Ag layers were modified with a self-assembled monolayer of 4-mercaptopyridine as a molecular Raman probe displaying a rich and unexpected Raman response. A resonant increase of the Raman intensity in the red part of the spectrum is observed that cannot be related to plasmon excitations of the cavity-array. Notably, we find an additional 1020 time increase of the SERS amplification upon deposition of a single Ag layer on the Au substrate, which is, however, almost quenched upon deposition of 10 atomic layers. Further deposition of 100 atomic Ag layers results in a new increase of the SERS signal, consistent with the improved plasmonic efficiency of Ag bulk-like structures. The SERS response as a function of the Ag layer thickness is analyzed in terms of ab initio calculations and a microscopic model for the SERS chemical mechanism based on a resonant charge transfer process between the molecular HOMO state and the Fermi level in the metal surface. We find that a rearrangement of the electronic charge density related to the presence of the Ag monolayer in the Au/Ag/molecule complex causes an increase in the distance between the HOMO center of charge and the metallic image plane that is responsible for the variation of Raman enhancement between the studied substrates. Our results provide a general platform for studying the chemical contribution to SERS, and for enhancing the Raman efficiency of tailored Au-SERS templates through electrochemical modification with Ag films.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000293035200019 Publication Date 2011-06-15
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1936-0851;1936-086X; ISBN Additional Links (up) UA library record; WoS full record; WoS citing articles
Impact Factor 13.942 Times cited 26 Open Access
Notes ; We acknowledge financial support from ANPCyT (Argentina, PICT08-1617, PICT08-2236, PICT06-621, PICT-CNPQ-08-0019, PAE 22711, PICT06-01061, PICT06-483) and Project CTQ2008-06017/BQU, Spain. N.G.T, E.C., A.D.H.N., R.C.S, G.U., C.A.B., and A.F. are also at CONICET. M.E.V. is a member of the research career of CIC BsAs. R.C.S., C.A.B., and A.F. are Guggenheim Foundation Fellows. We would like to thank Dr. M. H. Fonticelli for fruitful discussions on the electrochemical measurements and Dr. H. Pastoriza for the help with the SEM measurements. ; Approved Most recent IF: 13.942; 2011 IF: 11.421
Call Number UA @ lucian @ c:irua:91775 Serial 1285
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Author de Backer, A.; Van Aert, S.; van Dyck, D.
Title High precision measurements of atom column positions using model-based exit wave reconstruction Type A1 Journal article
Year 2011 Publication Ultramicroscopy Abbreviated Journal Ultramicroscopy
Volume 111 Issue 9/10 Pages 1475-1482
Keywords A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab
Abstract In this paper, it has been investigated how to measure atom column positions as accurately and precisely as possible using a focal series of images. In theory, it is expected that the precision would considerably improve using a maximum likelihood estimator based on the full series of focal images. As such, the theoretical lower bound on the variances of the unknown atom column positions can be attained. However, this approach is numerically demanding. Therefore, maximum likelihood estimation has been compared with the results obtained by fitting a model to a reconstructed exit wave rather than to the full series of focal images. Hence, a real space model-based exit wave reconstruction technique based on the channelling theory is introduced. Simulations show that the reconstructed complex exit wave contains the same amount of information concerning the atom column positions as the full series of focal images. Only for thin samples, which act as weak phase objects, this information can be retrieved from the phase of the reconstructed complex exit wave.
Address
Corporate Author Thesis
Publisher Place of Publication Amsterdam Editor
Language Wos 000300461200004 Publication Date 2011-07-28
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0304-3991; ISBN Additional Links (up) UA library record; WoS full record; WoS citing articles
Impact Factor 2.843 Times cited 8 Open Access
Notes Fwo Approved Most recent IF: 2.843; 2011 IF: 2.471
Call Number UA @ lucian @ c:irua:91879 Serial 1438
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Author Schattschneider, P.; Verbeeck, J.
Title Theory of free electron vortices Type A1 Journal article
Year 2011 Publication Ultramicroscopy Abbreviated Journal Ultramicroscopy
Volume 111 Issue 9/10 Pages 1461-1468
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract The recent creation of electron vortex beams and their first practical application motivates a better understanding of their properties. Here, we develop the theory of free electron vortices with quantized angular momentum, based on solutions of the Schrödinger equation for cylindrical boundary conditions. The principle of transformation of a plane wave into vortices with quantized angular momentum, their paraxial propagation through round magnetic lenses, and the effect of partial coherence are discussed.
Address
Corporate Author Thesis
Publisher Place of Publication Amsterdam Editor
Language Wos 000300461200002 Publication Date 2011-07-26
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0304-3991; ISBN Additional Links (up) UA library record; WoS full record; WoS citing articles
Impact Factor 2.843 Times cited 57 Open Access
Notes Esteem 026019 Approved Most recent IF: 2.843; 2011 IF: 2.471
Call Number UA @ lucian @ c:irua:91882 Serial 3617
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Author Kalkert, C.; Krisponeit, J.-O.; Esseling, M.; Lebedev, O.I.; Moshnyaga, V.; Damaschke, B.; Van Tendeloo, G.; Samwer, K.
Title Resistive switching at manganite/manganite interfaces Type A1 Journal article
Year 2011 Publication Applied physics letters Abbreviated Journal Appl Phys Lett
Volume 99 Issue 13 Pages 132512-132512,3
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract We report bipolar resistive switching between the interfaces of manganite nanocolumns. La0.7Sr0.3MnO3 films were prepared on Al2O3 substrates, where the films grow in nanocolumns from the substrate to the surface. Conductive atomic force microscopy directly detects that the resistive switching is located at the boundaries of the grains. Furthermore, mesoscopic transport measurements reveal a tunnel magnetoresistance. In combination with the resistive switching, this leads to a total of four different resistive states.
Address
Corporate Author Thesis
Publisher American Institute of Physics Place of Publication New York, N.Y. Editor
Language Wos 000295618000052 Publication Date 2011-09-29
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0003-6951; ISBN Additional Links (up) UA library record; WoS full record; WoS citing articles
Impact Factor 3.411 Times cited 10 Open Access
Notes Approved Most recent IF: 3.411; 2011 IF: 3.844
Call Number UA @ lucian @ c:irua:91884 Serial 2881
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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
Corporate Author Thesis
Publisher Place of Publication Basel Editor
Language Wos 000296471400006 Publication Date 2011-09-26
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1011-372X;1572-879X; ISBN Additional Links (up) 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
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Author Bittencourt, C.; Navio, C.; Nicolay, A.; Ruelle, B.; Godfroid, T.; Snyders, R.; Colomer, J.-F.; Lagos, M.J.; Ke, X.; Van Tendeloo, G.; Suarez-Martinez, I.; Ewels, C.P.
Title Atomic oxygen functionalization of vertically aligned carbon nanotubes Type A1 Journal article
Year 2011 Publication The journal of physical chemistry: C : nanomaterials and interfaces Abbreviated Journal J Phys Chem C
Volume 115 Issue 42 Pages 20412-20418
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Vertically aligned multiwalled carbon nanotubes (v-MWCNTs) are functionalized using atomic oxygen generated in a microwave plasma. X-ray photoelectron spectroscopy depth profile analysis shows that the plasma treatment effectively grafts oxygen exclusively at the v-MWCNT tips. Electron microscopy shows that neither the vertical alignment nor the structure of v-MWCNTs were affected by the plasma treatment. Density functional calculations suggest assignment of XPS C 1s peaks at 286.6 and 287.5 eV, to epoxy and carbonyl functional groups, respectively.
Address
Corporate Author Thesis
Publisher Place of Publication Washington, D.C. Editor
Language Wos 000296205600009 Publication Date 2011-10-04
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1932-7447;1932-7455; ISBN Additional Links (up) UA library record; WoS full record; WoS citing articles
Impact Factor 4.536 Times cited 31 Open Access
Notes Iap Approved Most recent IF: 4.536; 2011 IF: 4.805
Call Number UA @ lucian @ c:irua:91890 Serial 174
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Author Quintana, M.; Montellano, A.; Esau del Rio Castillo, A.; Van Tendeloo, G.; Bittencourt, C.; Prato, M.
Title Selective organic functionalization of graphene bulk or graphene edges Type A1 Journal article
Year 2011 Publication Chemical communications Abbreviated Journal Chem Commun
Volume 47 Issue 33 Pages 9330-9332
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Graphene sheets have been functionalized with a PAMAM dendron, finding that graphene can be efficiently functionalized all over the surface, or only at the edges, depending on the reactions used in the functionalization process.
Address
Corporate Author Thesis
Publisher Place of Publication London Editor
Language Wos 000293648200010 Publication Date 2011-07-20
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1359-7345;1364-548X; ISBN Additional Links (up) UA library record; WoS full record; WoS citing articles
Impact Factor 6.319 Times cited 84 Open Access
Notes Approved Most recent IF: 6.319; 2011 IF: 6.169
Call Number UA @ lucian @ c:irua:91892 Serial 2968
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Author Simon, Q.; Barreca, D.; Bekermann, D.; Gasparotto, A.; Maccato, C.; Comini, E.; Gombac, V.; Fornasiero, P.; Lebedev, O.I.; Turner, S.; Devi, A.; Fischer, R.A.; Van Tendeloo, G.
Title Plasma-assisted synthesis of Ag/ZnO nanocomposites : first example of photo-induced H2 production and sensing Type A1 Journal article
Year 2011 Publication International journal of hydrogen energy Abbreviated Journal Int J Hydrogen Energ
Volume 36 Issue 24 Pages 15527-15537
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Ag/ZnO nanocomposites were developed by a plasma-assisted approach. The adopted strategy exploits the advantages of Plasma Enhanced-Chemical Vapor Deposition (PE-CVD) for the growth of columnar ZnO arrays on Si(100) and Al2O3 substrates, in synergy with the infiltration power of the Radio Frequency (RF)-sputtering technique for the subsequent dispersion of different amounts of Ag nanoparticles (NPs). The resulting composites, both as-prepared and after annealing in air, were thoroughly characterized with particular attention on their morphological organization, structure and composition. For the first time, the above systems have been used as catalysts in the production of hydrogen by photo-reforming of alcoholic solutions, yielding a stable H2 evolution even by the sole use of simulated solar radiation. In addition, Ag/ZnO nanocomposites presented an excellent response in the gas-phase detection of H2, opening attractive perspectives for advanced technological applications.
Address
Corporate Author Thesis
Publisher Place of Publication Oxford Editor
Language Wos 000297089700006 Publication Date 2011-10-14
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0360-3199; ISBN Additional Links (up) UA library record; WoS full record; WoS citing articles
Impact Factor 3.582 Times cited 62 Open Access
Notes Esteem 026019; Fwo Approved Most recent IF: 3.582; 2011 IF: 4.054
Call Number UA @ lucian @ c:irua:91901 Serial 2627
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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.
Address
Corporate Author Thesis
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 (up) 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 Orlinskii, S.B.; Bogomolov, R.S.; Kiyamova, A.M.; Yavkin, B.V.; Mamin, G.M.; Turner, S.; Van Tendeloo, G.; Shiryaev, A.A.; Vlasov, I.I.; Shenderova, O.
Title Identification of substitutional nitrogen and surface paramagnetic centers in nanodiamond of dynamic synthesis by electron paramagnetic resonance Type A1 Journal article
Year 2011 Publication Nanoscience and nanotechnology letters Abbreviated Journal Nanosci Nanotech Let
Volume 3 Issue 1 Pages 63-67
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Production of nanodiamond particles containing substitutional nitrogen is important for a wide variety of advanced applications. In the current work nanodiamond particles synthesized from a mixture of graphite and hexogen were analyzed to determine the presence of substitutional nitrogen using pulsed electron paramagnetic resonance (EPR) spectroscopy. Nitrogen paramagnetic centers in the amount of 1.2 ppm have been identified. The spin relaxation characteristics for both nitrogen and surface defects are also reported. A new approach for efficient depletion of the strong non-nitrogen EPR signal in nanodiamond material by immersing nanodiamond particles into ice matrix is suggested. This approach allows an essential decrease of the spin relaxation time of the dominant non-nitrogen defects, while preserving the substitutional nitrogen spin relaxation time.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000293211200012 Publication Date 2011-09-19
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1941-4900;1941-4919; ISBN Additional Links (up) UA library record; WoS full record; WoS citing articles
Impact Factor 1.889 Times cited 14 Open Access
Notes Approved Most recent IF: 1.889; 2011 IF: 0.528
Call Number UA @ lucian @ c:irua:91943 Serial 1548
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Author Grodzinska, D.; Pietra, F.; van Huis, M.A.; Vanmaekelbergh, D.; de Mello Donegá, C.
Title Thermally induced atomic reconstruction of PbSe/CdSe core/shell quantum dots into PbSe/CdSe bi-hemisphere hetero-nanocrystals Type A1 Journal article
Year 2011 Publication Journal of materials chemistry Abbreviated Journal J Mater Chem
Volume 21 Issue 31 Pages 11556-11565
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract The properties of hetero-nanocrystals (HNCs) depend strongly on the mutual arrangement of the nanoscale components. In this work we have investigated the structural and morphological evolution of colloidal PbSe/CdSe core/shell quantum dots upon annealing under vacuum. Prior to annealing the PbSe core has an approximately octahedral morphology with eight {111} facets, and the CdSe shell has zinc-blende crystal structure. Thermal annealing under vacuum at temperatures between 150 °C and 200 °C induces a structural and morphological reconstruction of the HNCs whereby the PbSe core and the CdSe shell are reorganized into two hemispheres joined by a common {111} Se plane. This thermally induced reconstruction leads to considerable changes in the optical properties of the colloidal PbSe/CdSe HNCs.
Address
Corporate Author Thesis
Publisher Place of Publication Cambridge Editor
Language Wos 000293190200018 Publication Date 2011-04-21
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0959-9428;1364-5501; ISBN Additional Links (up) UA library record; WoS full record; WoS citing articles
Impact Factor Times cited 44 Open Access
Notes Approved Most recent IF: NA
Call Number UA @ lucian @ c:irua:91945 Serial 3632
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Author Nikolova, I.; Janssen, S.; Vrancken, K.; Vos, P.; Mishra, V.; Berghmans, P.
Title Size resolved ultrafine particles emission model : a continues size distribution approach Type A1 Journal article
Year 2011 Publication The science of the total environment Abbreviated Journal
Volume 409 Issue 18 Pages 3492-3499
Keywords A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL)
Abstract A new parameterization for size resolved ultrafine particles (UFP) traffic emissions is proposed based on the results of PARTICULATES project (Samaras et al., 2005). It includes the emission factors from the Emission Inventory Guidebook (2006) (total number of particles, #/km/veh), the shape of the corresponding particle size distribution given in PARTICULATES and data for the traffic activity. The output of the model UFPEM (UltraFine Particle Emission Model) is a sum of continuous distributions of ultrafine particles emissions per vehicle type (passenger cars and heavy duty vehicles), fuel (petrol and diesel) and average speed representative for urban, rural and highway driving. The results from the parameterization are compared with measured total number of ultrafine particles and size distributions in a tunnel in Antwerp (Belgium). The measured UFP concentration over the entire campaign shows a close relation to the traffic activity. The modelled concentration is found to be lower than the measured in the campaign. The average emission factor from the measurement is 4.29E + 14 #/km/veh whereas the calculated is around 30% lower. A comparison of emission factors with literature is done as well and in overall a good agreement is found. For the size distributions it is found that the measured distributions consist of three modes Nucleation, Aitken and accumulation and most of the ultrafine particles belong to the Nucleation and the Aitken modes. The modelled Aitken mode (peak around 0.040.05 μm) is found in a good agreement both as amplitude of the peak and the number of particles whereas the modelled Nucleation mode is shifted to smaller diameters and the peak is much lower that the observed. Time scale analysis shows that at 300 m in the tunnel coagulation and deposition are slow and therefore neglected. The UFPEM emission model can be used as a source term in dispersion models.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000293260100026 Publication Date 2011-06-19
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0048-9697; 1879-1026 ISBN Additional Links (up) UA library record; WoS full record; WoS citing articles
Impact Factor Times cited Open Access
Notes Approved no
Call Number UA @ admin @ c:irua:91949 Serial 8546
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Author Darchuk, L.; Gatto Rotondo, G.; Swaenen, M.; Worobiec, A.; Tsybrii, Z.; Makarovska, Y.; Van Grieken, R.
Title Composition of prehistoric rock-painting pigments from Egypt (Gilf Kébir area) Type A1 Journal article
Year 2011 Publication Spectrochimica acta: part A: molecular and biomolecular spectroscopy Abbreviated Journal
Volume 83 Issue 1 Pages 34-38
Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation); Laboratory Experimental Medicine and Pediatrics (LEMP)
Abstract The composition of rock-painting pigments from Egypt (Gilf Kebia area) has been analyzed by means of molecular spectroscopy such as Fourier transform infrared and micro-Raman spectroscopy and scanning electron microscopy coupled to an energy dispersive X-ray spectrometer and X-ray fluorescence analysis. Red and yellow pigments were recognized as red and yellow ochre with additional rutile.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000296827600005 Publication Date 2011-07-26
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1386-1425 ISBN Additional Links (up) UA library record; WoS full record; WoS citing articles
Impact Factor Times cited Open Access
Notes Approved no
Call Number UA @ admin @ c:irua:92015 Serial 7713
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Author Neyts, E.C.; van Duin, A.C.T.; Bogaerts, A.
Title Changing chirality during single-walled carbon nanotube growth : a reactive molecular dynamics/Monte Carlo study Type A1 Journal article
Year 2011 Publication Journal of the American Chemical Society Abbreviated Journal J Am Chem Soc
Volume 133 Issue 43 Pages 17225-17231
Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract The growth mechanism and chirality formation of a single-walled carbon nanotube (SWNT) on a surface-bound nickel nanocluster are investigated by hybrid reactive molecular dynamics/force-biased Monte Carlo simulations. The validity of the interatomic potential used, the so-called ReaxFF potential, for simulating catalytic SWNT growth is demonstrated. The SWNT growth process was found to be in agreement with previous studies and observed to proceed through a number of distinct steps, viz., the dissolution of carbon in the metallic particle, the surface segregation of carbon with the formation of aggregated carbon clusters on the surface, the formation of graphitic islands that grow into SWNT caps, and finally continued growth of the SWNT. Moreover, it is clearly illustrated in the present study that during the growth process, the carbon network is continuously restructured by a metal-mediated process, thereby healing many topological defects. It is also found that a cap can nucleate and disappear again, which was not observed in previous simulations. Encapsulation of the nanoparticle is observed to be prevented by the carbon network migrating as a whole over the cluster surface. Finally, for the first time, the chirality of the growing SWNT cap is observed to change from (11,0) over (9,3) to (7,7). It is demonstrated that this change in chirality is due to the metal-mediated restructuring process.
Address
Corporate Author Thesis
Publisher Place of Publication Washington, D.C. Editor
Language Wos 000297380900026 Publication Date 2011-10-06
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0002-7863;1520-5126; ISBN Additional Links (up) UA library record; WoS full record; WoS citing articles
Impact Factor 13.858 Times cited 116 Open Access
Notes Approved Most recent IF: 13.858; 2011 IF: 9.907
Call Number UA @ lucian @ c:irua:92043 Serial 309
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Author Kontozova-Deutsch, V.; Deutsch, F.; Bencs, L.; Krata, A.; Van Grieken, R.; De Wael, K.
Title Optimization of the ion chromatographic quantification of airborne fluoride, acetate and formate in the Metropolitan Museum of Art, New York Type A1 Journal article
Year 2011 Publication Talanta : the international journal of pure and applied analytical chemistry Abbreviated Journal Talanta
Volume 86 Issue Pages 372-376
Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Abstract Ion chromatographic (IC) methods have been compared in order to achieve an optimal separation of fluoride, acetate and formate under various elution conditions on two formerly introduced analytical columns (i and ii) and a novel one (iii): (i) an IonPac AS14 (250 mm × 4 mm I.D.), (ii) Allsep A-2 (150 mm × 4.6 mm I.D.), and (iii) an IC SI-50 4E (250 mm (length) × 4 mm (internal diameter – I.D.)). The IC conditions for the separation of the anions concerned were optimized on the IC SI-50 4E column. A near baseline separation of these anions was attained on the IonPac AS14, whereas the peaks of fluoride and acetate could not be resolved on the Allsep A-2. A baseline separation for the three anions was achieved on the IC SI-50 4E column, when applying an eluent mixture of 3.2 mmol/L Na2CO3 and 1.0 mmol/L NaHCO3 with a flow rate of 1.0 mL/min. The highest precision of 1.7, 3.0 and 2.8% and the best limits of detection (LODs) of 0.014, 0.22 and 0.17 mg/L for fluoride, acetate and formate, respectively, were obtained with the IC SI-50 4E column. Hence, this column was applied for the determination of the acetic and formic acid contents of air samples taken by means of passive gaseous sampling at the Metropolitan Museum of Art in New York, USA. Atmospheric concentrations of acetic and formic acid up to 1050 and 450 μg/m3, respectively, were found in non-aerated showcases of the museum. In galleries and outdoors, rather low levels of acetic and formic acid were detected with average concentrations of 50 and 10 μg/m3, respectively. The LOD data of acetate and formate on the IC SI-50 4E column correspond to around 0.5 μg/m3 for both acetic and formic acid in air samples.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000298126300048 Publication Date 2011-09-24
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0039-9140; 1873-3573 ISBN Additional Links (up) UA library record; WoS full record; WoS citing articles
Impact Factor 4.162 Times cited 19 Open Access
Notes ; The authors gratefully acknowledge the support of Marco Leona and the staff of the Metropolitan Museum of Art in New York during the sampling campaigns. The technical assistance and advice by Dr. Takashi Kotsuka and Shodex Benelux are acknowledged as well. ; Approved Most recent IF: 4.162; 2011 IF: 3.794
Call Number UA @ admin @ c:irua:92066 Serial 5762
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Author De Wael, K.; Bashir, Q.; van Vlierberghe, S.; Dubruel, P.; Heering, H.A.; Adriaens, A.
Title Electrochemical determination of hydrogen peroxide with cytochrome c peroxidase and horse heart cytochrome c entrapped in a gelatin hydrogel Type A1 Journal article
Year 2012 Publication Bioelectrochemistry: an international journal devoted to electrochemical aspects of biology and biological aspects of electrochemistry Abbreviated Journal Bioelectrochemistry
Volume 83 Issue Pages 15-18
Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Abstract A novel and versatile method, based on a membrane-free enzyme electrode in which both the enzyme and a mediator protein are entrapped in a gelatine hydrogel was developed for the fabrication of biosensors. As a proof of principle, we prepared a hydrogen peroxide biosensor by successfully entrapping both horse heart cytochrome c (HHC) and Saccharomyces cerevisae cytochrome c peroxidase (CCP) in a gelatin matrix which is immobilized on a gold electrode. This electrode was first pretreated with 6-mercaptohexanol. The biosensor displayed a rapid response and an expanded linear response range from 0 to 0.3 mM (R = 0.987) with a detection limit of 1 × 10− 5 M in a HEPES buffer solution (pH 7.0). This method of encapsulation is now further investigated for industrial biosensor applications.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000297962500003 Publication Date 2011-08-03
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1567-5394 ISBN Additional Links (up) UA library record; WoS full record; WoS citing articles
Impact Factor 3.346 Times cited 31 Open Access
Notes ; Karolien De Wael is grateful to the Research Foundation-Flanders (FWO, Belgium) for her postdoctoral fellowship. ; Approved Most recent IF: 3.346; 2012 IF: 3.947
Call Number UA @ admin @ c:irua:92067 Serial 5589
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Author Potgieter-Vermaak, S.S.; Mmari, A.; Van Grieken, R.; McCrindle, R.I.; Potgieter, J.H.
Title Degradation of galvanised iron roofing material in Tanzania by atmospheric corrosion Type A1 Journal article
Year 2011 Publication Corrosion engineering science and technology Abbreviated Journal
Volume 46 Issue 5 Pages 642-650
Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Abstract Galvanised iron is popular in many applications, particular as a roofing material. However, just like other materials, especially metallic ones, it is prone to degradation by corrosion. In this particular study, the degradation of galvanised roof sheets was investigated at a coastal, urban and rural site in Tanzania, Africa. Samples were exposed to various outdoor environments over a period of 3 years. In addition, some accelerated laboratory investigations were conducted in different simulated air pollution environments in an artificial corrosion chamber constructed for this purpose to supplement the outdoor exposure tests. It was found that the combination of the tropical climate and increasing air pollution due to industrial development in the capital Dar-es-Salaam resulted in substantial atmospheric corrosion of the roof sheets, which eventually leads to failure and the necessity for replacement. The rural site had the lowest degree of atmospheric corrosion as expected. A combination of different corrosion products was identified as a result of the atmospheric corrosion by Raman and EDX analyses. The information gained from this investigation could be utilised to construct more durable structures requiring less frequent replacement and maintenance in future.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000294421100008 Publication Date 2010-04-12
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1478-422x ISBN Additional Links (up) UA library record; WoS full record; WoS citing articles
Impact Factor Times cited Open Access
Notes Approved no
Call Number UA @ admin @ c:irua:92094 Serial 7758
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Author Kontozova, V.; Krupińska, B.; Van Grieken, R.; Janssen, E.; Moris, H.; Aerts, D.; Watteeuw, L.; van Bos, M.; Peckstadt, A.
Title Research for preventive conservation and optimal presentation of world heritage in Museum Plantin-Moretus, Antwerp Type P3 Proceeding
Year 2011 Publication Abbreviated Journal
Volume Issue Pages
Keywords P3 Proceeding; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Abstract
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos Publication Date
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN 978-989-97522-0-7 Additional Links (up) UA library record
Impact Factor Times cited Open Access
Notes Approved no
Call Number UA @ admin @ c:irua:92095 Serial 8473
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Author de Clippel, F.; Harkiolakis, A.; Vosch, T.; Ke, X.; Giebeler, L.; Oswald, S.; Houthoofd, K.; Jammaer, J.; Van Tendeloo, G.; Martens, J.A.; Jacobs, P.A.; Baron, G.V.; Sels, B.F.; Denayer, J.F.M.
Title Graphitic nanocrystals inside the pores of mesoporous silica : synthesis, characterization and an adsorption study Type A1 Journal article
Year 2011 Publication Microporous and mesoporous materials: zeolites, clays, carbons and related materials Abbreviated Journal Micropor Mesopor Mat
Volume 144 Issue 1/3 Pages 120-133
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract This work presents a new carbonsilica hybrid material, denoted as CSM, with remarkable sorption properties. It consists of intraporous graphitic nanocrystals grown in the pores of mesoporous silica. CSM is obtained by a subtle incipient wetness impregnation of Al-containing mesoporous silica with furfuryl alcohol (FA)/hemelitol solutions. Both the volume match of the impregnation solution with that of the silica template pore volume, and the presence of Al3+ in the silica, are crucial to polymerize FA selectively inside the mesopores. Carbonization of the intraporous polymer was then performed by pyrolysis under He up to 1273 K. The resulting CSMs were examined by SEM, HRTEM, 27Al MAS NMR, N2 adsorption, XRD, TGA, TPD, XPS, pycnometry and Raman spectroscopy. Mildly oxidized graphitic-like carbon nanoblocks, consisting of a few graphene-like sheets, were thus identified inside the template mesopores. Random stacking of these carbon crystallites generates microporosity resulting in biporous materials at low carbon content and microporous materials at high carbon loadings. Very narrow pore distributions were obtained when pyrolysis was carried out under slow heating rate, viz. 1 K min−1. Adsorption and shape selective properties of the carbon filled mesoporous silica were studied by performing pulse chromatography and breakthrough experiments, and by measuring adsorption isotherms of linear and branched alkanes. Whereas the parent mesoporous silica shows unselective adsorption, their CSM analogues preferentially adsorb linear alkanes. The sorption capacity and selectivity can be adjusted by changing the pore size of the template or by varying the synthesis conditions. A relation between the carbon crystallites size and the shape selective behaviour of the corresponding CSM for instance is demonstrated. Most interestingly, CSM shows separation factors for linear and branched alkanes up to values comparable to those of zeolitic molecular sieves.
Address
Corporate Author Thesis
Publisher Place of Publication Amsterdam Editor
Language Wos 000293435400016 Publication Date 2011-04-15
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1387-1811; ISBN Additional Links (up) UA library record; WoS full record; WoS citing articles
Impact Factor 3.615 Times cited 15 Open Access
Notes Approved Most recent IF: 3.615; 2011 IF: 3.285
Call Number UA @ lucian @ c:irua:92325 Serial 1380
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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.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000294777400013 Publication Date 2011-09-09
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1098-0121;1550-235X; ISBN Additional Links (up) 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 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
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Author Fang, C.M.; van Huis, M.A.; Jansen, J.; Zandbergen, H.W.
Title Role of carbon and nitrogen in Fe2C and Fe2N from first-principles calculations Type A1 Journal article
Year 2011 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B
Volume 84 Issue 9 Pages 094102-094102,10
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Although Fe2C and Fe2N are technologically important materials, the exact nature of the chemical bonding of C and N atoms and the related impact on the electronic properties are at present unclear. Here, results of first-principles electronic structure calculations for Fe2X (X = C, N) phases are presented. The electronic structure calculations show that the roles of N and C in iron nitrides and carbides are comparable, and that the X-X interactions have significant impact on electronic properties. Accurate analysis of the spatially resolved differences in electron densities reveals a subtle distinction between the chemical bonding and charge transfer of N and C ions.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000294772800003 Publication Date 2011-09-09
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1098-0121;1550-235X; ISBN Additional Links (up) UA library record; WoS full record; WoS citing articles
Impact Factor 3.836 Times cited 24 Open Access
Notes Approved Most recent IF: 3.836; 2011 IF: 3.691
Call Number UA @ lucian @ c:irua:92327 Serial 2912
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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
Corporate Author Thesis
Publisher Place of Publication Dordrecht Editor
Language Wos 000293923800004 Publication Date 2011-05-25
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0006-8314;1573-1472; ISBN Additional Links (up) 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
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