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Author Dixon, E.; Hadermann, J.; Hayward, M.A.
Title Structures and magnetism of La1-xSrxMnO3-(0.5+x)/2 (0.67\leq x\leq1) phases Type A1 Journal article
Year 2012 Publication Chemistry of materials Abbreviated Journal Chem Mater
Volume (up) 24 Issue 8 Pages 1486-1495
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Topotactic reduction of La1-xSrxMnO3 (0.67 <= x <= 1) phases with sodium hydride yields a series of isoelectronic materials of composition La1-xSrxMnO3-(0.5+x)/2. Lanthanum rich members of the series (0.67 <= x <= 0.83) adopt anion deficient perovskite structures with a 6-layer -OTOOT'O- stacking sequence of sheets of octahedra/square-based pyramids (O) and sheets of tetrahedra (T). The strontium rich members of the series (0.83 <= x <= 1) incorporate “step defects” into this 6-layer structure in which the OTOOT'O stacking sequence is converted into either OOTOOT' or TOOT'OO at a defect plane which runs perpendicular to the [201] lattice plane. The step defects appear to provide a mechanism to relieve lattice strain and accommodate additional anion deficiency in phases with x > 0.83. Magnetization and neutron diffraction data indicate La1-xSrxMnO3-(0.5+x)/2 phases adopt antiferromagnetically ordered states at low-temperature in which the ordered arrangement of magnetic spins is incommensurate with the crystallographic lattice.
Address
Corporate Author Thesis
Publisher Place of Publication Washington, D.C. Editor
Language Wos 000303092300011 Publication Date 2012-03-28
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0897-4756;1520-5002; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 9.466 Times cited 13 Open Access
Notes Esteem 026019 Approved Most recent IF: 9.466; 2012 IF: 8.238
Call Number UA @ lucian @ c:irua:98253 Serial 3318
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Author Chen, Y.; Shanenko, A.A.; Perali, A.; Peeters, F.M.
Title Superconducting nanofilms : molecule-like pairing induced by quantum confinement Type A1 Journal article
Year 2012 Publication Journal of physics : condensed matter Abbreviated Journal J Phys-Condens Mat
Volume (up) 24 Issue 18 Pages 185701-185701,8
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract Quantum confinement of the perpendicular motion of electrons in single-crystalline metallic superconducting nanofilms splits the conduction band into a series of single-electron subbands. A distinctive feature of such a nanoscale multi-band superconductor is that the energetic position of each subband can vary significantly with changing nanofilm thickness, substrate material, protective cover and other details of the fabrication process. It can occur that the bottom of one of the available subbands is situated in the vicinity of the Fermi level. We demonstrate that the character of the superconducting pairing in such a subband changes dramatically and exhibits a clear molecule-like trend, which is very similar to the well-known crossover from the Bardeen-Cooper-Schrieffer regime to Bose-Einstein condensation (BCS-BEC) observed in trapped ultracold fermions. For Pb nanofilms with thicknesses of 4 and 5 monolayers (MLs) this will lead to a spectacular scenario: up to half of all the Cooper pairs nearly collapse, shrinking in the lateral size (parallel to the nanofilm) down to a few nanometers. As a result, the superconducting condensate will be a coherent mixture of almost molecule-like fermionic pairs with ordinary, extended Cooper pairs.
Address
Corporate Author Thesis
Publisher Place of Publication London Editor
Language Wos 000303500900018 Publication Date 2012-04-05
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0953-8984;1361-648X; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.649 Times cited 26 Open Access
Notes ; This work was supported by the Flemish Science Foundation (FWO-Vl). AAS thanks A Bianconi, M D Croitoru and A V Vagov for useful discussions. AAS acknowledges the hospitality and fruitful interactions with G C Strinati, P Pieri and D Neilson during his visit to the University of Camerino, supported by the School of Advanced Studies of the University of Camerino. ; Approved Most recent IF: 2.649; 2012 IF: 2.355
Call Number UA @ lucian @ c:irua:98223 Serial 3357
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Author Lajevardipour, A.; Neek-Amal, M.; Peeters, F.M.
Title Thermomechanical properties of graphene : valence force field model approach Type A1 Journal article
Year 2012 Publication Journal of physics : condensed matter Abbreviated Journal J Phys-Condens Mat
Volume (up) 24 Issue 17 Pages 175303-175303,8
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract Using the valence force field model of Perebeinos and Tersoff (2009 Phys. Rev. B 79 241409(R)), different energy modes of suspended graphene subjected to tensile or compressive strain are studied. By carrying out Monte Carlo simulations it is found that: (i) only for small strains (vertical bar epsilon vertical bar (sic) 0.02) is the total energy symmetrical in the strain, while it behaves completely differently beyond this threshold; (ii) the important energy contributions in stretching experiments are stretching, angle bending, an out-of-plane term, and a term that provides repulsion against pi-pi misalignment; (iii) in compressing experiments the two latter terms increase rapidly, and beyond the buckling transition stretching and bending energies are found to be constant; (iv) from stretching-compressing simulations we calculated the Young's modulus at room temperature 350 +/- 3.15 N m(-1), which is in good agreement with experimental results (340 +/- 50 N m(-1)) and with ab initio results (322-353) N m(-1); (v) molar heat capacity is estimated to be 24.64 J mol(-1) K-1 which is comparable with the Dulong-Petit value, i. e. 24.94 J mol(-1) K-1, and is almost independent of the strain; (vi) nonlinear scaling properties are obtained from height-height correlations at finite temperature; (vii) the used valence force field model results in a temperature independent bending modulus for graphene, and (viii) the Gruneisen parameter is estimated to be 0.64.
Address
Corporate Author Thesis
Publisher Place of Publication London Editor
Language Wos 000303499700012 Publication Date 2012-04-05
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0953-8984;1361-648X; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.649 Times cited 29 Open Access
Notes ; We acknowledge helpful comments by V Perebeinos, S Costamagna, A Fasolino and J H Los. This work was supported by the Flemish science foundation (FWO-Vl) and the Belgium Science Policy (IAP). ; Approved Most recent IF: 2.649; 2012 IF: 2.355
Call Number UA @ lucian @ c:irua:99123 Serial 3639
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Author Dendooven, J.; Goris, B.; Devloo-Casier, K.; Levrau, E.; Biermans, E.; Baklanov, M.R.; Ludwig, K.F.; van der Voort, P.; Bals, S.; Detavernier, C.
Title Tuning the pore size of ink-bottle mesopores by atomic layer deposition Type A1 Journal article
Year 2012 Publication Chemistry of materials Abbreviated Journal Chem Mater
Volume (up) 24 Issue 11 Pages 1992-1994
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract
Address
Corporate Author Thesis
Publisher Place of Publication Washington, D.C. Editor
Language Wos 000305092600002 Publication Date 2012-05-03
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0897-4756;1520-5002; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 9.466 Times cited 52 Open Access
Notes Fwo Approved Most recent IF: 9.466; 2012 IF: 8.238
Call Number UA @ lucian @ c:irua:99078 Serial 3760
Permanent link to this record
 
 
Author Croitoru, M.D.; Shanenko, A.A.; Kaun, C.C.; Peeters, F.M.
Title Ultra-small metallic grains : effect of statistical fluctuations of the chemical potential on superconducting correlations and vice versa Type A1 Journal article
Year 2012 Publication Journal of physics : condensed matter Abbreviated Journal J Phys-Condens Mat
Volume (up) 24 Issue 27 Pages 275701
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract Superconducting correlations in an isolated metallic grain are governed by the interplay between two energy scales: the mean level spacing delta and the bulk pairing gap Delta(0), which are strongly influenced by the position of the chemical potential with respect to the closest single-electron level. In turn superconducting correlations affect the position of the chemical potential. Within the parity projected BCS model we investigate the probability distribution of the chemical potential in a superconducting grain with randomly distributed single-electron levels. Taking into account statistical fluctuations of the chemical potential due to the pairing interaction, we find that such fluctuations have a significant impact on the critical level spacing delta(c) at which the superconducting correlations cease: the critical ratio delta(c)/Delta(0) at which superconductivity disappears is found to be increased.
Address
Corporate Author Thesis
Publisher Place of Publication London Editor
Language Wos 000305653100012 Publication Date 2012-06-21
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0953-8984;1361-648X; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.649 Times cited 9 Open Access
Notes ; This work was supported by the European Community under the Marie Curie IEF Action (Grant Agreement No. PIEF-GA-2009-235486-ScQSR), the Flemish Science Foundation (FWO-Vl), the Belgian Science Policy (IAP), and the ESF network INSTANS. MDC and AAS are grateful to A Vagov for stimulating discussions. ; Approved Most recent IF: 2.649; 2012 IF: 2.355
Call Number UA @ lucian @ c:irua:100280 Serial 3793
Permanent link to this record
 
 
Author Croitoru, M.D.; Vagov, A.; Shanenko, A.A.; Axt, V.M.
Title The Cooper problem in nanoscale : enhancement of the coupling due to confinement Type A1 Journal article
Year 2012 Publication Superconductor science and technology Abbreviated Journal Supercond Sci Tech
Volume (up) 25 Issue 12 Pages 124001-124005
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract In 1956 Cooper demonstrated (1956 Phys. Rev. 104 1189) that, no matter how weak the attraction is, two electrons in three-dimensional (3D) space just above the Fermi sea could be bound. In this work we investigate the influence of confinement on the binding energy of a Cooper pair. We show that confinement-induced modification of the Fermi sea results in a significant increase of the binding energy, when the bottom of an energy subband is very close to the Fermi surface.
Address
Corporate Author Thesis
Publisher Place of Publication Bristol Editor
Language Wos 000311418100004 Publication Date 2012-11-08
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0953-2048;1361-6668; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.878 Times cited 9 Open Access
Notes ; MDC acknowledges support by the European Community under the Marie Curie IEF Action (Grant Agreement No. PIEF-GA-2009-235486-ScQSR). ; Approved Most recent IF: 2.878; 2012 IF: 2.758
Call Number UA @ lucian @ c:irua:105121 Serial 3573
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Author Aghaei, M.; Lindner, H.; Bogaerts, A.
Title Effect of a mass spectrometer interface on inductively coupled plasma characteristics : a computational study Type A1 Journal article
Year 2012 Publication Journal of analytical atomic spectrometry Abbreviated Journal J Anal Atom Spectrom
Volume (up) 27 Issue 4 Pages 604-610
Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract An inductively coupled plasma connected to a mass spectrometer interface (sampling cone) is computationally investigated. Typical plasma characteristics, such as gas flow velocity, plasma temperature and electron density, are calculated in two dimensions (cylindrical symmetry) and compared with and without a mass spectrometer sampling interface. The results obtained from our model compare favorably with experimental data reported in the literature. A dramatic increase in the plasma velocity is reported in the region close to the interface. Furthermore, a cooled metal interface lowers the plasma temperature and electron density on the axial channel very close to the sampling cone but the corresponding values in the off axial regions are increased. Therefore, the effect of the interface strongly depends on the measurement position. It is shown that even a small shift from the actual position of the sampler leads to a considerable change of the results.
Address
Corporate Author Thesis
Publisher Place of Publication London Editor
Language Wos 000301496700005 Publication Date 2012-02-22
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0267-9477;1364-5544; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.379 Times cited 18 Open Access
Notes Approved Most recent IF: 3.379; 2012 IF: 3.155
Call Number UA @ lucian @ c:irua:97386 Serial 791
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Author Savchenko, D.V.; Serdan, A.A.; Morozov, V.A.; Van Tendeloo, G.; Ionov, S.G.
Title Improvement of the oxidation stability and the mechanical properties of flexible graphite foil by boron oxide impregnation Type A1 Journal article
Year 2012 Publication New carbon materials Abbreviated Journal
Volume (up) 27 Issue 1 Pages 12-18
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Flexible graphite foil produced by rolling expanded graphite impregnated with boron oxide was analyzed by laser mass spectroscopy, X-ray photoelectron spectroscopy, scanning electron microscopy and thermogravimetry. It was shown that the modification of the graphite foil by boron oxide increases the onset temperature of oxidation by ∼ 150 °C. Impregnation of less than 2 mass% boron oxide also increased the tensile strength of the materials. The observed improvement was attributed to the blocking of active sites by boron oxide, which is probably chemically bonded to the edges of graphene sheets in expanded graphite particles.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000304742100002 Publication Date 2012-03-21
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1872-5805; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor Times cited 5 Open Access
Notes Iap Approved Most recent IF: NA
Call Number UA @ lucian @ c:irua:96958 Serial 1569
Permanent link to this record
 
 
Author Neyts, E.C.
Title PECVD growth of carbon nanotubes : from experiment to simulation Type A1 Journal article
Year 2012 Publication Journal of vacuum science and technology: B: micro-electronics processing and phenomena Abbreviated Journal
Volume (up) 30 Issue 3 Pages 030803-030803,17
Keywords A1 Journal article; Engineering sciences. Technology; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract Nanostructured carbon materials show a tremendous variety in atomic structure, morphology, properties, and applications. As all properties are ultimately determined by the structure of the material, a thorough understanding of the growth mechanisms that give rise to the particular structure is critical. On many occasions, it has been shown that plasma enhanced growth can be strongly beneficial. This review will describe the authors current understanding of plasma enhanced growth of carbon nanotubes, the prototypical example of nanostructured carbon materials, as obtained from experiments, simulations, and modeling. Specific emphasis is put on where experiments and computational approaches correspond, and where they differ. Also, the current status on simulating PECVD growth of some other carbon nanomaterials is reviewed, including amorphous carbon, graphene, and metallofullerenes. Finally, computational challenges with respect to the simulation of PECVD growth are identified.
Address
Corporate Author Thesis
Publisher Place of Publication New York, N.Y. Editor
Language Wos 000305042000010 Publication Date 2012-04-16
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2166-2746; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor Times cited 42 Open Access
Notes Approved Most recent IF: NA
Call Number UA @ lucian @ c:irua:97166 Serial 2570
Permanent link to this record
 
 
Author Delabie, A.; Sioncke, S.; Rip, J.; Van Elshocht, S.; Pourtois, G.; Mueller, M.; Beckhoff, B.; Pierloot, K.
Title Reaction mechanisms for atomic layer deposition of aluminum oxide on semiconductor substrates Type A1 Journal article
Year 2012 Publication Journal of vacuum science and technology: A: vacuum surfaces and films Abbreviated Journal J Vac Sci Technol A
Volume (up) 30 Issue 1 Pages 01a127-01a127,10
Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract In this work, we have studied the TMA/H(2)O (TMA Al(CH(3))(3)) atomic layer deposition (ALD) of Al(2)O(3) on hydroxyl (OH) and thiol (SH) terminated semiconductor substrates. Total reflection x-ray fluorescence reveals a complex growth-per-cycle evolution during the early ALD reaction cycles. OH and SH terminated surfaces demonstrate growth inhibition from the second reaction cycle on. Theoretical calculations, based on density functional theory, are performed on cluster models to investigate the first TMA/H(2)O reaction cycle. Based on the theoretical results, we discuss possible mechanisms for the growth inhibition from the second reaction cycle on. In addition, our calculations show that AlCH(3) groups are hydrolyzed by a H(2)O molecule adsorbed on a neighboring Al atom, independent of the type of backbonds (Si-O, Ge-O, or Ge-S) of AlCH(3). The coordination of Al remains four-fold after the first TMA/H(2)O reaction cycle. (C) 2012 American Vacuum Society. [DOI: 10.1116/1.3664090]
Address
Corporate Author Thesis
Publisher Place of Publication New York, N.Y. Editor
Language Wos 000298992800027 Publication Date 2011-12-02
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0734-2101; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 1.374 Times cited 41 Open Access
Notes Approved Most recent IF: 1.374; 2012 IF: 1.432
Call Number UA @ lucian @ c:irua:96253 Serial 2818
Permanent link to this record
 
 
Author Van Passel, S.; Meul, M.
Title Multilevel and multi-user sustainability assessment of farming systems Type A1 Journal article
Year 2012 Publication Environmental Impact Assessment Review Abbreviated Journal Environ Impact Asses
Volume (up) 32 Issue 1 Pages 170-180
Keywords A1 Journal article; Engineering sciences. Technology
Abstract Sustainability assessment is needed to build sustainable farming systems. A broad range of sustainability concepts, methodologies and applications already exists. They differ in level, focus, orientation, measurement, scale, presentation and intended end-users. In this paper we illustrate that a smart combination of existing methods with different levels of application can make sustainability assessment more profound, and that it can broaden the insights of different end-user groups. An overview of sustainability assessment tools on different levels and for different end-users shows the complementarities and the opportunities of using different methods. In a case-study, a combination of the sustainable value approach (SVA) and MOTIFS is used to perform a sustainability evaluation of farming systems in Flanders. SVA is used to evaluate sustainability at sector level, and is especially useful to support policy makers, while MOTIFS is used to support and guide farmers towards sustainability at farm level. The combined use of the two methods with complementary goals can widen the insights of both farmers and policy makers, without losing the particularities of the different approaches. To stimulate and support further research and applications, we propose guidelines for multilevel and multi-user sustainability assessments.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000297874000020 Publication Date 2011-09-21
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0195-9255 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.094 Times cited 49 Open Access
Notes ; ; Approved Most recent IF: 3.094; 2012 IF: 1.851
Call Number UA @ admin @ c:irua:94186 Serial 6231
Permanent link to this record
 
 
Author Meul, M.; Van Passel, S.; Fremaut, D.; Haesaert, G.
Title Higher sustainability performance of intensive grazing versus zero-grazing dairy systems Type A1 Journal article
Year 2012 Publication Agronomy For Sustainable Development Abbreviated Journal Agron Sustain Dev
Volume (up) 32 Issue 3 Pages 629-638
Keywords A1 Journal article; Engineering sciences. Technology; Engineering Management (ENM)
Abstract Although grazing of dairy cows is an integral part of dairy farming in many European countries, farmers today more often choose for zero-grazing systems, where cows are housed throughout the year. Some studies already compared grazing and zero-grazing systems for specific issues such as labor efficiency, environmental impact, or animal welfare. In our study, we perform a more integrated evaluation, considering relevant ecological, economic, and social aspects. This allows for a balanced and more complete comparison of the sustainability performance of the two production methods. We evaluated ten intensive grazing and ten zero-grazing specialized Flemish dairy farms on the use of nutrients and energy, productivity and profitability, labor input, and animal welfare. In addition, we put special effort in formulating useful management advice for farmers. Therefore, we combined a detailed analysis of the sustainability indicators with an intensive interaction and discussion with farmers and farm advisors. Results show that, on average, the zero-grazing farms performed significantly worse from an ecological and economic point of view. This fact is explained mainly due to a less efficient use of concentrates and byproducts. Social sustainability performance did not differ significantly between the two groups. As a result, the integrated sustainability performance was significantly lower for the zero-grazing group. This finding shows that a further shift from intensive grazing to zero-grazing can move dairy farming in Flanders further away from sustainability. An important advice to improve the ecological and economic performance of zero-grazing farms is to optimize cows' rations to include more forages and optimize forage production and use. More detailed site- and case-specific management advice for farmers of both groups was provided during a discussion meeting. We consider this an essential additional step to any sustainability evaluation, since progress can only be made when monitoring results are translated into practical measures.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000306061800003 Publication Date 2012-01-11
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1774-0746 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 4.101 Times cited 26 Open Access
Notes ; ; Approved Most recent IF: 4.101; 2012 IF: 3.573
Call Number UA @ admin @ c:irua:127557 Serial 6209
Permanent link to this record
 
 
Author Kuznetsov, A.S.; Cuong, N.T.; Tikhomirov, V.K.; Jivanescu, M.; Stesmans, A.; Chibotaru, L.F.; Velázquez, J.J.; Rodríguez, V.D.; Kirilenko, D.; Van Tendeloo, G.; Moshchalkov, V.V.
Title Effect of heat-treatment on luminescence and structure of Ag nanoclusters doped oxyfluoride glasses and implication for fiber drawing Type A1 Journal article
Year 2012 Publication Optical materials Abbreviated Journal Opt Mater
Volume (up) 34 Issue 4 Pages 616-621
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract The effect of heat treatment on the structure and luminescence of Ag nanoclusters doped oxyfluoride glasses was studied and the implication for drawing the corresponding fibers doped with luminescent Ag nanoclusters has been proposed. The heat treatment results, first, in condensation of the Ag nanoclusters into larger Ag nanoparticles and loss of Ag luminescence, and further heat treatment results in precipitation of a luminescent-loss nano- and microcrystalline Ag phases onto the surface of the glass. Thus, the oxyfluoride fiber doped with luminescent Ag nanoclusters was pulled from the viscous glass melt and its attenuation loss was 0.19 dB/cm in the red part of the spectrum; i.e. near to the maximum of Ag nanoclusters luminescence band. The nucleation centers for the Ag nanoclusters in oxyfluoride glasses have been suggested to be the fluorine vacancies and their nanoclusters.
Address
Corporate Author Thesis
Publisher Place of Publication Amsterdam Editor
Language Wos 000300124500006 Publication Date 2011-10-18
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0925-3467; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.238 Times cited 25 Open Access
Notes Methusalem Approved Most recent IF: 2.238; 2012 IF: 1.918
Call Number UA @ lucian @ c:irua:93632 Serial 811
Permanent link to this record
 
 
Author Potgieter-Vermaak, S.; Rotondo, G.; Novacovic, V.; Rollins, S.; Van Grieken, R.
Title Component-specific toxic concerns of the inhalable fraction of urban road dust Type A1 Journal article
Year 2012 Publication Environmental geochemistry and health Abbreviated Journal
Volume (up) 34 Issue 6 Pages 689-696
Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Abstract Continuous global urbanisation causes an ever-growing ecological footprint of pollution. Road dust (RD), one of these pollutants, poses a health concern due to carcinogenic and toxic components potentially present in the micron-sized fractions. The literature reports on the concentrations of trace, toxic metals and metalloids present in RD (Hooker and Nathanail in Chem Geol 226:340-351, 2006), but the literature on its molecular composition is limited. Recent reports on the bioaccessibility of platinum group metals are also reported (Colombo et al. in Chem Geol 226:340-351, 2008). In vitro and animal toxicological studies confirmed that the chemical composition of inhaled particles plays a major role in its toxic, genotoxic and carcinogenic mechanisms, but the component-specific toxic effects are still not understood. Particle-bound airborne transition metals can also lead to the production of reactive oxygen species in lung tissue; a special concern amongst particularly susceptible cohorts (children and elderly). The characterisation of the molecular composition of the fine fraction is evidently of importance for public health. During a pilot study, partially characterised size-fractioned RD samples (Barrett et al. in Eviron Sci Technol 44:2940-2946, 2010) were analysed for their elemental concentration using X-ray fluorescence spectrometry and inductively coupled plasma mass spectrometry. In addition, separately dispersed particles (200 particles per size fraction) were analysed individually by means of computer-controlled electron probe X-ray micro-analysis (CC-EPXMA) and their molecular structure probed by studying elemental associations. These were correlated with micro-Raman spectroscopy (MRS) results. It was found that the fine fraction (< 38 mu m) had the highest Pb (238 ppm) and Cr (171 ppm) concentrations. The CC-EPXMA data showed > 50 % association of Cr-rich particles with Pb, and the MRS data showed that the Cr was mostly present as lead chromate and therefore in the Cr(VI) oxidation state. Concentrations of both Pb and Cr decreased substantially (279 (< 38 mu m)-13 ppm (< 1 mm); 171 (< 38 mu m)-91 ppm (< 1 mm), respectively) in the larger fractions. Apart from rather alarmingly high concentrations of oxidative stressors (Cu, Fe, Mn), the carcinogenic and toxic potential of the inhalable fraction is evident. Preliminary bioaccessibility data indicated that both Cr and Pb are readily mobilised in artificial lysosomal liquid and up to 19 % of Cr and 47 % of Pb were released.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000310540300005 Publication Date 2012-09-28
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0269-4042 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor Times cited Open Access
Notes Approved no
Call Number UA @ admin @ c:irua:102135 Serial 7699
Permanent link to this record
 
 
Author Wang, B.; Idrissi, H.; Galceran, M.; Colla, M.S.; Turner, S.; Hui, S.; Raskin, J.P.; Pardoen, T.; Godet, S.; Schryvers, D.
Title Advanced TEM investigation of the plasticity mechanisms in nanocrystalline freestanding palladium films with nanoscale twins Type A1 Journal article
Year 2012 Publication International journal of plasticity Abbreviated Journal Int J Plasticity
Volume (up) 37 Issue Pages 140-156
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Nanocrystalline palladium thin films deposited by electron-beam evaporation and deformed by on-chip tensile testing reveal a surprisingly large strain hardening capacity when considering the small similar to 25 nm grain size. The as-grown films contain several coherent single and multifold twin boundaries. The coherency of the twin boundaries considerably decreases with deformation due to dislocation/twin boundary interactions. These reactions are described based on a detailed analysis of the number and the type of dislocations located at the twin boundaries using high-resolution TEM, including aberration corrected microscopy. Sessile Frank dislocations were observed at the twin/matrix interfaces, explaining the loss of the TB coherency due to the Burgers vector pointing out of the twinning plane. Grain boundary mediated processes were excluded as a mechanism dominating the plastic deformation based on the investigation of the grain size distribution as well as the crystallographic texture using Automated Crystallographic Orientation Indexation TEM. Other factors influencing the plastic deformation such as impurities and the presence of a native passivation oxide layer at the surface of the films were investigated using analytical TEM. The twin boundaries observed in the present work partly explain the high strain hardening capacity by providing both increasing resistance to dislocation motion with deformation and a source for dislocation multiplication. (C) 2012 Elsevier Ltd. All rights reserved.
Address
Corporate Author Thesis
Publisher Place of Publication Oxford Editor
Language Wos 000307416100009 Publication Date 2012-05-16
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0749-6419; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 5.702 Times cited 44 Open Access
Notes Iap; Fwo Approved Most recent IF: 5.702; 2012 IF: 4.356
Call Number UA @ lucian @ c:irua:101082 Serial 74
Permanent link to this record
 
 
Author Horemans, B.; Schalm, O.; De Wael, K.; Cardell, C.; Van Grieken, R.
Title Atmospheric composition and micro-climate in the Alhambra monument, Granada (Spain), in the context of preventive conservation Type P1 Proceeding
Year 2012 Publication IOP conference series : materials science and engineering Abbreviated Journal
Volume (up) 37 Issue Pages 012002-12008
Keywords P1 Proceeding; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Abstract The world famous Alhambra monument in Granada, Southern Spain, listed as UNESCO world cultural heritage since 1984, represents probably the most beautiful example of Islamic art and architecture from the Middle Ages in Europe. It is visited by ca. 2 million people annually. Granada is situated in a natural basin, surrounded by mountains with altitudes up to 3500 m. Due to this topography and the prevailing low wind speeds, pollution-derived and especially traffic-derived particulate matter often accumulates in the urban air. In order to evaluate the potential conservation risks from the surrounding air, the atmospheric composition in the Alhambra monument was evaluated. Indoor temperature and relative humidity fluctuations were evaluated for their potential degenerative effects. Furthermore, the atmospheric composition in the Alhambra was analyzed in terms of inorganic gases (NO2, SO2, O3, and NH3) and black carbon. It was found that the open architecture protected the indoor environments from developing a potentially harmful microclimate, such as the build-up of humidity resulting from the huge number of daily tourists. On the downside, the strong ventilation made the indoor air hardly different from outdoor air, as characterized by strong diurnal temperature and relative humidity gradients and high traffic-derived pollutant levels.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000307662000002 Publication Date 2012-07-16
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1757-8981; 1757-899x ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor Times cited 1 Open Access
Notes ; ; Approved Most recent IF: NA
Call Number UA @ admin @ c:irua:100112 Serial 5484
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Author Özen, M.; Mertens, M.; Luyten, J.; Snijkers, F.; d' Hondt, H.; Cool, P.
Title Hydrothermal synthesis of carbonate-free submicron-sized barium titanate from an amorphous precursor : synthesis and characterization Type A1 Journal article
Year 2012 Publication Ceramics international Abbreviated Journal Ceram Int
Volume (up) 38 Issue 1 Pages 619-625
Keywords A1 Journal article; Electron microscopy for materials research (EMAT); Laboratory of adsorption and catalysis (LADCA)
Abstract In this paper, the amorphous barium titanate precursor was prepared by the peroxo-hydroxide method and post-treated by various drying procedures, such as: room temperature drying, room temperature vacuum drying and vacuum drying at 50 degrees C. The objective in the latter two treatments was to increase the Ti-O-Ba bonds of the precursor. The post-treated precursors were compared with the untreated (i.e., 'wet') precursor. Also, a barium titanate precursor was prepared by an alkoxide route. Afterwards, the precursors were hydrothermally treated at 200 degrees C in a 10 M NaOH solution. Vacuum drying of the precursor seemingly promoted the formation of Ti-O-Ti bonds in the hydrothermal end-product. The low Ba:Ti ratio (0.66) of the alkoxide-route prepared precursor lead to a multi-phase hydrothermal product with BaTiO(3) as the main phase. In contrast, phase pure BaTiO(3), i.e. without BaCO(3) contamination, was obtained for the precursor which was dried at room temperature. Cube-shaped and highly crystalline BaTiO(3) particles were observed by electron microscopy for the hydrothermally treated peroxo-hydroxide-route prepared precursor. (C) 2011 Elsevier Ltd and Techna Group S.r.l. All rights reserved.
Address
Corporate Author Thesis
Publisher Place of Publication Barking Editor
Language Wos 000298766900083 Publication Date 2011-08-02
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0272-8842; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.986 Times cited 14 Open Access
Notes Approved Most recent IF: 2.986; 2012 IF: 1.789
Call Number UA @ lucian @ c:irua:96263 Serial 1541
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Author Cagno, S.; Favaretto, L.; Mendera, M.; Izmer, A.; Vanhaecke, F.; Janssens, K.
Title Evidence of early medieval soda ash glass in the archaeological site of San Genesio (Tuscany) Type A1 Journal article
Year 2012 Publication Journal of archaeological science Abbreviated Journal J Archaeol Sci
Volume (up) 39 Issue 5 Pages 1540-1552
Keywords A1 Journal article; Philosophy; History; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Abstract The early medieval period marks an important turning point in the history of glassmaking, since it comprises the transition period between the mineral-based silica-soda-lime glass of the Roman tradition and the plant ash-based glass. With the aim of expanding the knowledge on the glass recipes and technologies of this period, 37 glass samples were analyzed, originating from the archaeological excavations of San Genesio (Tuscany) and dated from the fourth to the eleventh century. The major and minor element concentrations were measured with SEM-EDX, while the trace elements were quantified with LA-ICP-MS. The results were compared with published compositions of glass samples of similar age in order to highlight differences and similarities. The results offer a very interesting view on the glass circulation in the religious/residential/manufacturing center of San Genesio in the early medieval period. Most of the glass has a typical late-Roman composition, but some glass fragments are identified as soda ash glass. These are among the earliest medieval ash-fluxed glasses ever found in the Italian peninsula. (C) 2011 Elsevier Ltd. All rights reserved.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000301620900034 Publication Date 2012-01-02
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0305-4403 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.602 Times cited 24 Open Access
Notes ; This research was supported by the Interuniversity Attraction Poles Programme – Belgian Science Policy (IUAP VI/16). The text also presents results of GOA “XANES meets ELNES” (Research Fund University of Antwerp, Belgium) and from FWO (Brussels, Belgium) projects no. G.0704.08 and G.01769.09. ; Approved Most recent IF: 2.602; 2012 IF: 1.889
Call Number UA @ admin @ c:irua:98251 Serial 5618
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Author Cagno, S.; Badano, M.B.; Mathis, F.; Strivay, D.; Janssens, K.
Title Study of medieval glass fragments from Savona (Italy) and their relation with the glass produced in Altare Type A1 Journal article
Year 2012 Publication Journal of archaeological science Abbreviated Journal J Archaeol Sci
Volume (up) 39 Issue 7 Pages 2191-2197
Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Abstract Altare was in the medieval and post-medieval period an important glassmaking center in the Liguria region in Northern Italy. The first historical evidence of glassmaking in Altare is dated to the twelfth century. In spite of that, due to the continuity of glassmaking up to the present time and the contemporaneous intensive urbanization of the territory, no medieval glass from Altare or its immediate vicinity has been analyzed up to now. In this work, glass from archaeological excavations in the center of Savona, city with close ties with the glassmaking center, was studied. Glass fragments, dated from the tenth to the sixteenth century were selected from the collections of the Archaeological Museum in Savona and non-destructively analyzed with quantitative PIXE-PIGE. The resulting compositions, compared with known glass productions of the same time and evaluated on the basis of historical documents, offer an interesting panorama on the variety of glass circulation in Liguria. (C) 2012 Elsevier Ltd. All rights reserved.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000305849400027 Publication Date 2012-03-29
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0305-4403 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.602 Times cited 21 Open Access
Notes ; This research was supported by the Interuniversity Attraction Poles Programme – Belgian Science Policy (IUAP VI/16). The text also presents results of GOA “XANES meets ELNES” (Research Fund University of Antwerp, Belgium) and from FWO (Brussels, Belgium) projects no. G.0704.08 and G.01769.09. The authors gratefully acknowledge Prof. Carlo Varaldo for allowing the study of the glass preserved in the Archaeological Museum of Savona. ; Approved Most recent IF: 2.602; 2012 IF: 1.889
Call Number UA @ admin @ c:irua:100332 Serial 5849
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Author Witters, N.; Mendelsohn, R.; Van Passel, S.; Van Slycken, S.; Weyens, N.; Schreurs, E.; Meers, E.; Tack, F.; Vanheusden, B.; Vangronsveld, J.
Title Phytoremediation, a sustainable remediation technology? 2 : economic assessment of CO2 abatement through the use of phytoremediation crops for renewable energy production Type A1 Journal article
Year 2012 Publication Biomass & Bioenergy Abbreviated Journal Biomass Bioenerg
Volume (up) 39 Issue Pages 470-477
Keywords A1 Journal article; Economics; Engineering Management (ENM)
Abstract Phytoremediation could be a sustainable remediation alternative for conventional remediation technologies. However, its implementation on a commercial scale remains disappointing. To emphasize its sustainability, this paper examines whether and how the potential economic benefit of CO2 abatement for different crops used for phytoremediation or sustainable land management purposes could promote phytotechnologies. Our analysis is based on a case study in the Campine region, where agricultural soils are contaminated with mainly cadmium. We use Life Cycle Analysis to show for the most relevant crops (willow (Salix spp), energy maize (Zea mays), and rapeseed (Brassica napus)), that phytoremediation, used for renewable energy production, could abate CO2. Converting this in economic numbers through the Marginal Abatement Cost of CO2 ( 20 ton−1) we can integrate this in the economic analysis to compare phytoremediation crops among each other, and phytoremediation with conventional technologies. The external benefit of CO2 abatement when using phytoremediation crops for land management ranges between 55 and 501 per hectare. The purpose of these calculations is not to calculate a subsidy for phytoremediation. There is no reason why one would prefer phytoremediation crops for renewable energy production over normal biomass. Moreover, subsidies for renewable energy already exist. Therefore, we should not integrate these numbers in the economic analysis again. However, these numbers could contribute to making explicit the competitive advantage of phytoremediation compared to conventional remediation technologies, but also add to a more sustainably funded decision on which crop should be grown on contaminated land.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000302829900054 Publication Date 2011-12-20
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0961-9534 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.219 Times cited 38 Open Access
Notes ; ; Approved Most recent IF: 3.219; 2012 IF: 2.975
Call Number UA @ admin @ c:irua:129863 Serial 6236
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Author De Backer, L.A.; Vos, W.; de Backer, J.; Van Holsbeke, C.; Vinchurkar, S.; de Backer, W.
Title The acute effect of budesonide/formoterol in COPD : a multi-slice computed tomography and lung function study Type A1 Journal article
Year 2012 Publication European Respiratory Journal Abbreviated Journal Eur Respir J
Volume (up) 40 Issue 2 Pages 298-305
Keywords A1 Journal article; Biophysics and Biomedical Physics; Condensed Matter Theory (CMT); Laboratory Experimental Medicine and Pediatrics (LEMP)
Abstract The Global Initiative for Chronic Obstructive Lung Disease (GOLD) classification of chronic obstructive pulmonary disease (COPD) does not always match with other clinical disease descriptors such as exacerbation frequency and quality of life, indicating that forced expiratory volume in 1 s (FEV1) is not a perfect descriptor of the disease. The aim of this study was to find out whether changes in airway geometry after inhalation of the most commonly used inhalation therapy in severe COPD can more adequately be described with an image-based approach than with spirometry. 10 COPD GOLD stage III patients were assessed in a double-blind crossover study. Airway volumes were analysed using segmentation of multi-slice computed tomography (MSCT) images; airway resistance was determined using computational fluid dynamics (CFD). Distal airway volume significantly increased (p=0.011) in patients 4 h after receiving a budesonide/formoterol combination from 9.6+/-4.67 cm(3) to 10.14+/-4.81 cm(3). Also CFD-determined airway resistance significantly decreased (p=0.047) from 0.051+/-0.021 kPa.s.L-1 to 0.043+/- 0.019 kPa.s.L-1. None of the lung function parameters showed a significant change. Only functional residual capacity (FRC) showed a trend to decline (p=0.056). Only the image-based parameters were able to predict the visit at which the combination product was administered. This study showed that imaging is a sensitive, complementary tool to describe changes in airway structure.
Address
Corporate Author Thesis
Publisher Place of Publication Copenhagen Editor
Language Wos 000307291700006 Publication Date 2011-12-20
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0903-1936;1399-3003; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 10.569 Times cited 37 Open Access
Notes ; ; Approved Most recent IF: 10.569; 2012 IF: 6.355
Call Number UA @ lucian @ c:irua:101113 Serial 3568
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Author Godoi, R.H.M.; Hirata, P.Y.; Bitterncourt, A.V.L.; Godoi, A.F.L.; Potgieter-Vermaak, S.; Gatto Rotondo, G.; Van Grieken, R.; et al.
Title Geochemical assessment of a subtropical reservoir : a case study in Curitiba, Southern Brazil Type A1 Journal article
Year 2012 Publication Clean : soil, air, water Abbreviated Journal
Volume (up) 40 Issue 4 Pages 364-372
Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Abstract Suspended particles and dissolved substances in water provide reactive surfaces, influence metabolic activity and contribute to the net sediment deposition. It therefore plays an important part in the ecology and quality of the water mass. The water quality in reservoirs is crucial and it is naturally maintained by flushing and sedimentation, which continuously remove phosphorus from the water. In some reservoirs, however, these removal processes are countered by recycling of ions which could play a key role to start and/or maintain the eutrophic state. The combination of macro-, trace- and microanalysis techniques can be useful to trace pollution sources through a chemical fingerprint, whether be during an acute environmental disaster or a long-term release of pollutants. The water quality and total metal content of reservoir sediments were assessed in a reservoir, situated in the capital of the Paraná State, in the South-Eastern part of Brazil. The goal of this paper was to determine the metal presence in the sediment and metal and ionic speciation in the Green River reservoir water. Water and bed sediment samples, collected from various sites during 2008 and 2009, were investigated using XRF, ICP-OES, ICP-MS, XRD and zeta potential measurements. Based on the results, the heavy metal concentration and chemical composition of the suspended matter in the water samples, as well as the sediment's chemical composition will be discussed.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000302607800005 Publication Date 2012-01-05
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1863-0650 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor Times cited Open Access
Notes Approved no
Call Number UA @ admin @ c:irua:96973 Serial 7993
Permanent link to this record
 
 
Author Maes, D.; Van Passel, S.
Title Interference of regional support policies on the economic and environmental performance of a hybrid cogeneration-solar panel energy system Type A1 Journal article
Year 2012 Publication Energy Policy Abbreviated Journal Energ Policy
Volume (up) 42 Issue Pages 670-680
Keywords A1 Journal article; Engineering sciences. Technology; Engineering Management (ENM)
Abstract This paper assesses unintentional interference between different public policies promoting energy efficiency and renewable energy. The paper develops a methodology to study the interference by analysing the economic and technical behaviour of a hybrid energy system. The hybrid energy system in this case consists of an existing cogeneration unit extended with a new installation of thermal solar panels. This puts two complementary heating technologies in juxtaposition. The two technologies are supported with distinct regional support instruments in each region. The design and operation of the energy system is optimised from the point of view of the investor according to the different support instruments. The optimal configuration is analysed as well as its effect on reduced CO2-emissions during the lifetime of the project. The methodology is applied to a case-study for two neighbouring regions, the Netherlands and Flanders. The policies in the Netherlands show a beneficial synergy. In Flanders, the hybrid energy system is not interesting, indicating unbalanced high support for cogeneration in this case. From the point of view of the authorities, a more balanced regional policy as in the Netherlands provides a larger CO2-emission reduction for a smaller cost. (C) 2012 Elsevier Ltd. All rights reserved.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000301616000066 Publication Date 2012-01-14
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0301-4215; 1873-6777 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 4.14 Times cited 4 Open Access
Notes ; The authors would especially like to thank Davy Duelen for the excellent case-study and data collection that enabled the present paper. The help and information provided by Pierre Gijsen also made the detailed assessment possible. We are also indebted to two anonymous reviewers, whose remarks strongly improved the paper. This project has been financed by the Impulse-project of the tUL (transnational University Limburg). ; Approved Most recent IF: 4.14; 2012 IF: 2.743
Call Number UA @ admin @ c:irua:127558 Serial 6220
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Author Xu, Q.; Zandbergen, H.W.; van Dyck, D.
Title Imaging from atomic structure to electronic structure Type A1 Journal article
Year 2012 Publication Micron Abbreviated Journal Micron
Volume (up) 43 Issue 4 Pages 524-531
Keywords A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab
Abstract This paper discusses the possibility of retrieving the electron distribution (with highlighted valence electron distribution information) of materials from recorded HREM images. This process can be achieved by solving two inverse problems: reconstruction of the exit wave and reconstruction of the electron distribution from exit waves. The first inverse problem can be solved using a focal series reconstruction method. We show that the second inverse problem can be solved by combining a series of exit waves recorded at different thickness conditions. This process is designed based on an improved understanding of the dynamical scattering process. It also explains the fundamental difficulty of obtaining the valence electron distribution information and the basis of our solution.
Address
Corporate Author Thesis
Publisher Place of Publication Oxford Editor
Language Wos 000301702400005 Publication Date 2011-11-05
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0968-4328; ISBN Additional Links UA library record; WoS full record
Impact Factor 1.98 Times cited Open Access
Notes Fwo Approved Most recent IF: 1.98; 2012 IF: 1.876
Call Number UA @ lucian @ c:irua:93634 Serial 1553
Permanent link to this record
 
 
Author Van Aert, S.; van den Broek, W.; Goos, P.; van Dyck, D.
Title Model-based electron microscopy : from images toward precise numbers for unknown structure parameters Type A1 Journal article
Year 2012 Publication Micron Abbreviated Journal Micron
Volume (up) 43 Issue 4 Pages 509-515
Keywords A1 Journal article; Engineering Management (ENM); Electron microscopy for materials research (EMAT); Vision lab
Abstract Statistical parameter estimation theory is proposed as a method to quantify electron microscopy images. It aims at obtaining precise and accurate values for the unknown structure parameters including, for example, atomic column positions and types. In this theory, observations are purely considered as data planes, from which structure parameters have to be determined using a parametric model describing the images. The method enables us to measure positions of atomic columns with a precision of the order of a few picometers even though the resolution of the electron microscope is one or two orders of magnitude larger. Moreover, small differences in averaged atomic number, which cannot be distinguished visually, can be quantified using high-angle annular dark field scanning transmission electron microscopy images. Finally, it is shown how to optimize the experimental design so as to attain the highest precision. As an example, the optimization of the probe size for nanoparticle radius measurements is considered. It is also shown how to quantitatively balance signal-to-noise ratio and resolution by adjusting the probe size.
Address
Corporate Author Thesis
Publisher Place of Publication Oxford Editor
Language Wos 000301702400003 Publication Date 2011-11-03
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0968-4328; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 1.98 Times cited 7 Open Access
Notes Fwo Approved Most recent IF: 1.98; 2012 IF: 1.876
Call Number UA @ lucian @ c:irua:94114 Serial 2099
Permanent link to this record
 
 
Author Potgieter-Vermaak, S.; Horemans, B.; Anaf, W.; Cardell, C.; Van Grieken, R.
Title Degradation potential of airborne particulate matter at the Alhambra monument : a Raman spectroscopic and electron probe X-ray microanalysis study Type A1 Journal article
Year 2012 Publication Journal of Raman spectroscopy Abbreviated Journal
Volume (up) 43 Issue 11 Pages 1570-1577
Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Abstract It is well known that airborne particulate matter (APM) has an impact on our cultural heritage. A limited number of articles have been published on the sequential application of elemental and molecular techniques to estimate the degradation potential of APM in environments of cultural heritage importance, and most of these were concerned with indoor environments. The Alhambra monument (Granada, Spain) represents one of the grandest and finest examples of Islamic art and architecture from the Middle Ages. As part of an air quality investigation, two sets of APM were collected at the Hall of the Ambassadors and characterised to determine its potential degradation profile. These were analysed by means of micro-Raman spectroscopy (MRS) and electron probe microanalysis with X-ray detection (EPXMA). The Raman data indicated the presence of various mixed salts of acidic and/or hygroscopic nature, such as sodium and ammonium nitrates and sulfates, especially in the finer fraction. Automated EPXMA estimated this fraction to be as high as 50%. Apart from the potential chemical attack, the soiling due to carbonaceous matter deposition is a real concern. Soot was identified by MRS and EPXMA in all size fractions, reaching values of up to 55%, and was often intertwined with soluble inorganic salts. Ongoing degradation of the pigments is implicated by the presence of brightly coloured particles. MRS and molar abundance ternary diagrams elicited the chemical structure of individual APM so that the degradation potential could be established.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000311417000008 Publication Date 2012-07-05
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0377-0486 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor Times cited Open Access
Notes Approved no
Call Number UA @ admin @ c:irua:102570 Serial 7759
Permanent link to this record
 
 
Author Zhang, Y.-R.; Xu, X.; Bogaerts, A.; Wang, Y.-N.
Title Fluid simulation of the phase-shift effect in hydrogen capacitively coupled plasmas: 1 : transient behaviour of electrodynamics and power deposition Type A1 Journal article
Year 2012 Publication Journal of physics: D: applied physics Abbreviated Journal J Phys D Appl Phys
Volume (up) 45 Issue 1 Pages 015202-015202,11
Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract A two-dimensional self-consistent fluid model coupled with the full set of Maxwell equations is established to investigate the phase-shift effect on the transient behaviour of electrodynamics and power deposition in a hydrogen capacitively coupled plasma. The effect has been examined at 13.56 MHz and 100 MHz, respectively, because of the different phase-shift modulation when the electromagnetic effects are dominant. The results indicate that the spatiotemporal distributions of the plasma characteristics obtained for various phase-shift cases are obviously different both in shape and especially in absolute values. Indeed, when the phase difference varies from 0 to π, there is an increase in the electron flux, thus the power deposition becomes more pronounced. At the frequency of 13.56 MHz, the axial electron flux in the bulk plasma becomes uniform along the z-axis, and the radial electron flux exhibits two peaks within one period at the reverse-phase case, whereas the oscillation is less pronounced at the in-phase case. Furthermore, in the very high frequency discharge, the radial electron flux is alternately positive and negative with four peaks during one period, and the ionization mainly occurs in the sheath region, due to the prominent power deposition there at a phase difference equal to π.
Address
Corporate Author Thesis
Publisher Place of Publication London Editor
Language Wos 000298290000011 Publication Date 2011-12-12
Series Editor Series Title Abbreviated Series Title
Series Volume 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 57 Open Access
Notes Approved Most recent IF: 2.588; 2012 IF: 2.528
Call Number UA @ lucian @ c:irua:92851 Serial 1230
Permanent link to this record
 
 
Author Zhang, Y.-R.; Xu, X.; Bogaerts, A.; Wang, Y.-N.
Title Fluid simulation of the phase-shift effect in hydrogen capacitively coupled plasmas: 2 : radial uniformity of the plasma characteristics Type A1 Journal article
Year 2012 Publication Journal of physics: D: applied physics Abbreviated Journal J Phys D Appl Phys
Volume (up) 45 Issue 1 Pages 015203-015203,13
Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract A two-dimensional fluid model, including the full set of Maxwell equations, has been developed and applied to investigate the effect of a phase shift between two power sources on the radial uniformity of several plasma characteristics in a hydrogen capacitively coupled plasma. This study was carried out at various frequencies in the range 13.56200 MHz. When the frequency is low, at 13.56 MHz, the plasma density is characterized by an off-axis peak when both power sources are in-phase (phgr = 0), and the best radial uniformity is obtained at phgr = π. This trend can be explained because the radial nonuniformity caused by the electrostatic edge effect can be effectively suppressed by the phase-shift effect at a phase difference equal to π. When the frequency rises to 60 MHz, the plasma density profiles shift smoothly from edge-peaked over uniform to centre-peaked as the phase difference increases, due to the pronounced standing-wave effect, and the best radial uniformity is reached at phgr = 0.3π. At a frequency of 100 MHz, a similar behaviour is observed, except that the maximum of the plasma density moves again towards the radial edge at the reverse-phase case (phgr = π), because of the dominant skin effect. When the frequency is 200 MHz, the bulk plasma density increases significantly with increasing phase-shift values, and a better uniformity is obtained at phgr = 0.4π. This is because the density in the centre increases faster than at the radial edge as the phase difference rises, due to the increasing power deposition Pz in the centre and the decreasing power density Pr at the radial edge. As the phase difference increases to π, the maximum near the radial edge becomes obvious again. This is because the skin effect has a predominant influence on the plasma density under this condition, resulting in a high density at the radial edge. Moreover, the axial ion flux increases monotonically with phase difference, and exhibits similar profiles to the plasma density. The calculation results illustrate that the radial uniformity of the various plasma characteristics is strongly dependent on the applied frequency and the phase shift between both power sources, which is important to realize, for controlling the uniformity of the plasma etch and deposition processes.
Address
Corporate Author Thesis
Publisher Place of Publication London Editor
Language Wos 000298290000012 Publication Date 2011-12-12
Series Editor Series Title Abbreviated Series Title
Series Volume 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 15 Open Access
Notes Approved Most recent IF: 2.588; 2012 IF: 2.528
Call Number UA @ lucian @ c:irua:92852 Serial 1231
Permanent link to this record
 
 
Author Zhang, Y.-R.; Bogaerts, A.; Wang, Y.-N.
Title Fluid simulation of the phase-shift effect in Ar/CF4 capacitively coupled plasmas Type A1 Journal article
Year 2012 Publication Journal of physics: D: applied physics Abbreviated Journal J Phys D Appl Phys
Volume (up) 45 Issue 48 Pages 485204
Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract A two-dimensional self-consistent fluid model combined with the full set of Maxwell equations is employed to investigate an Ar/CF4 capacitively coupled plasma, focusing on the phase-shift effect on the plasma characteristics at various frequencies and gas mixture ratios. When the discharge is sustained by a single frequency at 13.56 MHz in an Ar/CF4 mixture with a ratio of 0.9/0.1, no obvious difference is detected between the electron densities obtained in the so-called electrostatic model (with only the static electric fields taken into account) and the electromagnetic model (which includes the electromagnetic effects). However, as the frequency increases to 60 and 100 MHz, the difference becomes distinct, due to the significant influence of the electromagnetic effects. The phase-shift effect on the plasma radial uniformity has also been investigated in a dual frequency discharge, i.e. when the top driven source is switched on with a phase difference phiv ranging from 0 to π, in the frequency range 13.56100 MHz. At low concentration of CF4 (10%), Ar+ ions are the major positive ions in the entire range of frequencies. When the frequency is low, i.e. 13.56 MHz, the Ar+ density exhibits an off-axis peak at phiv = 0 due to the edge effect, and a better uniformity caused by the phase-shift modulation is obtained at phiv = π. At 60 MHz, the Ar+ density varies from edge-peaked at phiv = 0 to uniform (i.e. at phiv = 0.53π), and finally at phiv = π, a broad maximum is observed at the centre due to the standing-wave effect. As the frequency increases to 100 MHz, the best radial uniformity is reached at 0.25π, and the maximum moves again towards the radial wall in the reverse-phase case (phiv = π) due to the dominant skin effect. When the frequency is fixed at 100 MHz, the phase-shift control shows a different behaviour at a high concentration of CF4. For instance, the ${\rm CF}_3
Address
Corporate Author Thesis
Publisher Place of Publication London Editor
Language Wos 000311148300011 Publication Date 2012-11-06
Series Editor Series Title Abbreviated Series Title
Series Volume 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 8 Open Access
Notes Approved Most recent IF: 2.588; 2012 IF: 2.528
Call Number UA @ lucian @ c:irua:101754 Serial 1232
Permanent link to this record
 
 
Author Neyts, E.C.; Bogaerts, A.
Title Modeling the growth of SWNTs and graphene on the atomic scale Type A1 Journal article
Year 2012 Publication ECS transactions Abbreviated Journal
Volume (up) 45 Issue 4 Pages 73-78
Keywords A1 Journal article; Engineering sciences. Technology; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract The possibility of application of nanomaterials is determined by our ability to control the properties of the materials, which are ultimately determined by their structure and hence their growth processes. We employ hybrid molecular dynamics / Monte Carlo (MD/MC) simulations to explore the growth of SWNTs and graphene on nickel as a catalyst, with the specific goal of unraveling the growth mechanisms. While the general observations are in agreement with the literature, we find a number of interesting phenomena to be operative which are crucial for the growth, and which are not accessible by MD simulations alone due to the associated time scale. Specifically, we observe metal mediated healing and restructuring processes to take place, reorganizing the carbon network during the initial nucleation step. In the case of carbon nanotube growth, this leads to the growth of tubes with a determinable chirality. In the case of graphene formation, we find that graphene is only formed at temperatures above 700 K. These results are of importance for understanding the growth mechanisms of these carbon nanomaterials on the fundamental level.
Address
Corporate Author Thesis
Publisher Electrochemical Society Place of Publication Pennington Editor
Language Wos 000316890000008 Publication Date 2012-04-27
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1938-6737;1938-5862; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor Times cited 2 Open Access
Notes Approved Most recent IF: NA
Call Number UA @ lucian @ c:irua:108535 Serial 2144
Permanent link to this record