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“Cs7Nd11(SeO3)12Cl16 : first noncentrosymmetric structure among alkaline-metal lanthanide selenite halides”. Berdonosov PS, Akselrud L, Prots Y, Abakumov AM, Smet PF, Poelman D, Van Tendeloo G, Dolgikh VA, Inorganic chemistry 52, 3611 (2013). http://doi.org/10.1021/ic301442f
Abstract: Cs7Nd11(SeO3)(12)Cl-16, the complex selenite chloride of cesium and neodymium, was synthesized in the NdOCl-SeO2-CsCl system. The compound has been characterized using single-crystal X-ray diffraction, electron diffraction, transmission electron microscopy, luminescence spectroscopy, and second-harmonic-generation techniques. Cs7Nd11(SeO3)(12)Cl-16 crystallizes in an orthorhombic unit cell with a = 15.911(1) angstrom, b = 15.951(1) angstrom, and c = 25.860(1) angstrom and a noncentrosymmetric space group Pna2(1) (No. 33). The crystal structure of Cs7Nd11(SeO3)(12)Cl-16 can be represented as a stacking of Cs7Nd11(SeO3)(12) lamellas and CsCl-like layers. Because of the layered nature of the Cs7Nd11(SeO3)(12)Cl-16 structure, it features numerous planar defects originating from occasionally missing the CsCl-like layer and violating the perfect stacking of the Cs7Nd11(SeO3)(12)Cl-16 lamellas. Cs7Nd11(SeO3)(12)Cl-16 represents the first example of a noncentrosymmetric structure among alkaline-metal lanthanide selenite halides. Cs7Nd11(SeO3)(12)Cl-16 demonstrates luminescence emission in the near-IR region with reduced efficiency due to a high concentration of Nd3+ ions causing nonradiative cross-relaxation.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 4.857
Times cited: 10
DOI: 10.1021/ic301442f
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“Crystal structure and magnetic properties of the Cr-doped spiral antiferromagnet BiMnFe2O6”. Batuk D, de Dobbelaere C, Tsirlin AA, Abakumov AM, Hardy A, van Bael MK, Greenblatt M, Hadermann J, Materials research bulletin 48, 2993 (2013). http://doi.org/10.1016/j.materresbull.2013.04.038
Abstract: We report the Cr3+ for Mn3+ substitution in the BiMnFe2O6 structure. The BiCrxMn1-xFe2O6 solid solution is obtained by the solution-gel synthesis technique for the x values up to 0.3. The crystal structure investigation using a combination of X-ray powder diffraction and transmission electron microscopy demonstrates that the compounds retain the parent BiMnFe2O6 structure (for x = 0.3, a = 5.02010(6)angstrom, b = 7.06594(7)angstrom, c = 12.6174(1)angstrom, S.G. Pbcm, R-1 = 0.036, R-p = 0.011) with only a slight decrease in the cell parameters associated with the Cr3+ for Mn3+ substitution. Magnetic susceptibility measurements suggest strong similarities in the magnetic behavior of BiCrxMn1-xFe2O6 (x = 0.2; 0.3) and parent BiMnFe2O6. Only T-N slightly decreases upon Cr doping that indicates a very subtle influence of Cr3+ cations on the magnetic properties at the available substitution rates. (C) 2013 Elsevier Ltd. All rights reserved.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 2.446
Times cited: 3
DOI: 10.1016/j.materresbull.2013.04.038
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Verstraelen H (2013) Corrosion in ballast tanks on board of merchant vessels : study of the relation between steel quality and corrosion. 172 p
Keywords: Doctoral thesis; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL)
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Kapra A (2013) Controlling the flux dynamics in superconductors by nanostructured magnetic arrays. Antwerpen
Keywords: Doctoral thesis; Condensed Matter Theory (CMT)
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“Controlling pore size and uniformity of mesoporous titania by early stage low temperature stabilization”. Herregods SJF, Mertens M, Van Havenbergh K, Van Tendeloo G, Cool P, Buekenhoudt A, Meynen V, Journal of colloid and interface science 391, 36 (2013). http://doi.org/10.1016/j.jcis.2012.07.098
Abstract: The control of the formation process during and after self-assembly is of utmost importance to achieve well structured, controlled template-assisted mesoporous titania materials with the desired properties for various applications via the evaporation induced self-assembly method (EISA). The present paper reports on the large influence of the thermal stabilization and successive template removal on the pore structure of a mesostructured TiO2 material using the diblock copolymer Brij 58 as surfactant. A controlled thermal stabilization (temperature and duration) allows one to tailor the final pore size and uniformity much more precise by influencing the self-assembly of the template. Moreover, also the successive thermal template removal needs to be controlled in order to avoid a structural collapse. N2-sorption, TGA, TEM, FT-Raman spectroscopy, and small angle wide angle XRD have been used to follow the crystal growth and mesostructure organization after thermal stabilization and after thermal template removal, revealing its effect on the final pore structure.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT); Laboratory of adsorption and catalysis (LADCA)
Impact Factor: 4.233
Times cited: 12
DOI: 10.1016/j.jcis.2012.07.098
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“Controlling magnetic flux motion by arrays of zigzag-arranged magnetic bars”. Kapra AV, Misko VR, Peeters FM, Superconductor science and technology 26, 025011 (2013). http://doi.org/10.1088/0953-2048/26/2/025011
Abstract: Recent advances in manufacturing arrays of artificial pinning sites, i.e., antidots, blind holes and magnetic dots, allowed an effective control of magnetic flux in superconductors. An array of magnetic bars deposited on top of a superconducting film was shown to display different pinning regimes depending on the direction of the in-plane magnetization of the bars. Changing the sign of their magnetization results in changes in the induced magnetic pinning potentials. By numerically solving the time-dependent Ginzburg-Landau equations in a superconducting film with periodic arrays of zigzag-arranged magnetic bars, we revealed various flux dynamics regimes. In particular, we demonstrate flux pinning and flux flow, depending on the direction of the magnetization of the magnetic bars. Remarkably, the revealed different flux-motion regimes are associated with different mechanisms of vortex-antivortex dynamics. For example, we found that for an 'antiparallel' configuration of magnetic bars this dynamics involves a repeating vortex-antivortex generation and annihilation. We show that the depinning transition and the onset of flux flow can be manipulated by the magnetization of the bars and the geometry of the array. This provides an effective control of the depinning critical current that can be useful for possible fluxonics applications.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 2.878
Times cited: 5
DOI: 10.1088/0953-2048/26/2/025011
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“Conservation of stained glass windows with protective glazing : main results from the European VIDRIO research programme”. Bernardi A, Becherini F, Verità, M, Godoi RHM, Kontozova-Deutsch V, Van Grieken R, et al, Journal of cultural heritage 14, 527 (2013). http://doi.org/10.1016/J.CULHER.2012.11.009
Abstract: The methodology of protecting the European stained glass windows against environmental risk (e.g. meteorological factors, air pollution, microorganisms) by means of an external glazing is not new. In spite of many scientific studies carried out in the last 20 years, some questions were still up for discussion. The European VIDRIO (20022005) project gave an answer to these questions. The research carried out by the different project partners established a new multidisciplinary approach aimed at evaluating the efficiency of the protective glazing systems and their effects on stained glass windows conservation, and finally at assessing the most appropriate strategy to preserve stained glass windows. Scientific results showed that the so-called isothermal glazing (i.e. ventilation by the air coming from the inside of the building) protected efficiently the ancient stained glass window from environmental attack (i.e. rain, pollutants, condensation, thermal shocks) with very limited secondary effects. The scientific research highlighted that its efficiency was strongly related to the technical design of the protective system. In particular, the ventilation and the size of the interspace had to be carefully considered. The research developed within the VIDRIO project was turned into general recommendations to the owners and practitioners on the best practice for the stained glass windows future conservation.
Keywords: A1 Journal article; Art; History; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1016/J.CULHER.2012.11.009
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“Confinement effects on electron and phonon degrees of freedom in nanofilm superconductors : a Green function approach”. Saniz R, Partoens B, Peeters FM, Physical review : B : condensed matter and materials physics 87, 064510 (2013). http://doi.org/10.1103/PhysRevB.87.064510
Abstract: The Green function approach to the Bardeen-Cooper-Schrieffer theory of superconductivity is used to study nanofilms. We go beyond previous models and include effects of confinement on the strength of the electron-phonon coupling as well as on the electronic spectrum and on the phonon modes. Within our approach, we find that in ultrathin films, confinement effects on the electronic screening become very important. Indeed, contrary to what has been advanced in recent years, the sudden increases of the density of states when new bands start to be occupied as the film thickness increases, tend to suppress the critical temperature rather than to enhance it. On the other hand, the increase of the number of phonon modes with increasing number of monolayers in the film leads to an increase in the critical temperature. As a consequence, the superconducting critical parameters in such nanofilms are determined by these two competing effects. Furthermore, in sufficiently thin films, the condensate consists of well-defined subcondensates associated with the occupied bands, each with a distinct coherence length. The subcondensates can interfere constructively or destructively giving rise to an interference pattern in the Cooper pair probability density.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.836
Times cited: 6
DOI: 10.1103/PhysRevB.87.064510
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Zarenia M (2013) Confined states in mono- and bi-layer grapheme nanostructures. Antwerpen
Keywords: Doctoral thesis; Condensed Matter Theory (CMT)
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“Conductance maps of quantum rings due to a local potential perturbation”. Petrovic MD, Peeters FM, Chaves A, Farias GA, Journal of physics : condensed matter 25, 495301 (2013). http://doi.org/10.1088/0953-8984/25/49/495301
Abstract: We performed a numerical simulation of the dynamics of a Gaussian shaped wavepacket inside a small sized quantum ring, smoothly connected to two leads and exposed to a perturbing potential of a biased atomic force microscope tip. Using the Landauer formalism, we calculated conductance maps of this system in the case of single and two subband transport. We explain the main features in the conductance maps as due to the AFM tip influence on the wavepacket phase and amplitude. In the presence of an external magnetic field, the tip modifies the phi(0) periodic Aharonov-Bohm oscillation pattern into a phi(0)/2 periodic Al'tshuler-Aronov-Spivak oscillation pattern. Our results in the case of multiband transport suggest tip selectivity to higher subbands, making them more observable in the total
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 2.649
Times cited: 12
DOI: 10.1088/0953-8984/25/49/495301
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“Conclusions and recommendations”. Reniers GLL, Sörensen K, Vrancken K page 265 (2013).
Keywords: H1 Book chapter; Engineering Management (ENM); Sustainable Energy, Air and Water Technology (DuEL)
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“Comparative study of electron temperature and excitation temperature in a magnetic pole enhanced-inductively coupled argon plasma”. Khan AW, Jan F, Saeed A, Zaka-ul-Islam M, Abrar M, Khattak NAD, Zakaullah M, Current applied physics 13, 1241 (2013). http://doi.org/10.1016/j.cap.2013.03.016
Abstract: Magnetic Pole Enhanced-Inductively Coupled Plasmas (MaPE-ICPs) in analogy to the conventional ICPs exhibit two modes of operation, depending on the power coupling mechanism, i.e., a low power mode with dominant capacitive coupling (E-mode) and a high power mode with dominant inductive coupling (H-mode). A comparative study of the electron temperature measured by a Langmuir probe (T-e(LP)) and the electron excitation temperature (T-exc(OES)) determined by Optical Emission Spectroscopy (OES) is reported in the two distinct modes of a MaPE-ICP operated in argon. The dependence of T-e(LP), T-exc(OES) and their ratio (T-e(LP)/T-exc(OES)) on applied power (5-50 W) and gas pressure (15-60 mTorr) is explored, and the validity of T-exc(OES) as an alternative diagnostic to T-e(LP) is tested in the two modes of MaPE-ICP. The OES based non-invasive measurement of the plasma parameters such as electron temperature is very useful for plasma processing applications in which probe measurements are limited. (C) 2013 Elsevier B. V. All rights reserved.
Keywords: A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Impact Factor: 1.971
Times cited: 13
DOI: 10.1016/j.cap.2013.03.016
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“Comment on “Quantized orbital angular momentum transfer and magnetic dichroism in the interaction of electron vortices with matter””. Schattschneider P, Löffler S, Verbeeck J, Physical review letters 110, 189501 (2013). http://doi.org/10.1103/PhysRevLett.110.189501
Keywords: Editorial; Electron microscopy for materials research (EMAT)
Impact Factor: 8.462
Times cited: 8
DOI: 10.1103/PhysRevLett.110.189501
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“Combining molecular dynamics with Monte Carlo simulations : implementations and applications”. Neyts EC, Bogaerts A, Theoretical chemistry accounts : theory, computation, and modeling 132, 1320 (2013). http://doi.org/10.1007/s00214-012-1320-x
Abstract: In this contribution, we present an overview of the various techniques for combining atomistic molecular dynamics with Monte Carlo simulations, mainly in the context of condensed matter systems, as well as a brief summary of the main accelerated dynamics techniques. Special attention is given to the force bias Monte Carlo technique and its combination with molecular dynamics, in view of promising recent developments, including a definable timescale. Various examples of the application of combined molecular dynamics / Monte Carlo simulations are given, in order to demonstrate the enhanced simulation efficiency with respect to either pure molecular dynamics or Monte Carlo.
Keywords: A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Impact Factor: 1.89
Times cited: 27
DOI: 10.1007/s00214-012-1320-x
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“Cognitive mapping : a method to elucidate and present farmers' risk perception”. van Winsen F, de Mey Y, Lauwers L, Van Passel S, Vancauteren M, Wauters E, Agricultural Systems 122, 42 (2013). http://doi.org/10.1016/J.AGSY.2013.08.003
Abstract: Assumptions on the perceptions of risks, made in agricultural economics literature, are recognized to be over-simplistic. For example most studies assume that risks are independent and static, while in reality most risks are interlinked and dynamic. We propose an alternative method to identify and present risk perception, closer to the actual comprehension of risk by farmers. Grounded theory is used to investigate the perceptions of risk by farmers while avoiding prior assumptions. Main findings are: (i) farmers have difficulty to rank or score probability and impact of risks in a (semi)quantitative manner; (ii) farmers attach different meanings to risk, when the focus shifts between, uncertain event, probability or value at stake and; (iii) farmers perceive risks as being interrelated. Based on these findings, we propose that farmers' risk perception can be best understood as a network of interrelated notions of uncertain events, their effects and uncertain outcomes. Furthermore, cognitive mapping is suggested to elucidate and present these networks. We test cognitive mapping, exploring dairy farmers' risk perception, and demonstrate the appropriateness of this methodology for capturing the complexity and context of perceived risk. Advantages are: (i) the qualitative approach, (ii) the focus on interrelations and context, (iii) the applicability at farm level, (iv) the farmer-driven rather than researcher-driven perspective, and (v) the elucidation of the polyvalent use of the risk concept. Cognitive maps can be used as a communication tool, a risk management tool, and a tool to stimulate bi-directional learning amongst farmers, policy makers, researchers and extension agents. (C) 2013 Elsevier Ltd. All rights reserved.
Keywords: A1 Journal article
Impact Factor: 2.571
Times cited: 27
DOI: 10.1016/J.AGSY.2013.08.003
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“Ciliary white light generated during femtosecond laser ablation on transparent dielectrics”. Liu Y, Brelet Y, He Z, Yu L, Mitryukovskiy S, Houard A, Forestier B, Couairon A, Mysyrowicz A, 2013 Conference On And International Quantum Electronics Conference Lasers And Electro-optics Europe (cleo Europe/iqec) (2013)
Keywords: P1 Proceeding; Electron microscopy for materials research (EMAT)
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“Ciliary white light : optical aspect of ultrashort laser ablation on transparent dielectrics”. Liu Y, Brelet Y, He Z, Yu L, Mitryukovskiy S, Houard A, Forestier B, Couairon A, Mysyrowicz A, Physical review letters 110, 097601 (2013). http://doi.org/10.1103/PhysRevLett.110.097601
Abstract: We report on a novel nonlinear optical phenomenon, coined as ciliary white light, during laser ablation of transparent dielectrics. It is observed in 14 different transparent materials including glasses, crystals, and polymers. This phenomenon is also universal with respect to laser polarization, pulse duration, and focusing geometry. We interpret its formation in terms of the nonlinear diffraction of the laser generated white light by the ablation crater covered by nanostructures. It carries rich information on the damage profile and morphology dynamics of the ablated surface, providing a real time in situ observation of the laser ablation process. DOI: 10.1103/PhysRevLett.110.097601
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 8.462
Times cited: 10
DOI: 10.1103/PhysRevLett.110.097601
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“Chemical insight into electroforming of resistive switching manganite heterostructures”. Borgatti F, Park C, Herpers A, Offi F, Egoavil R, Yamashita Y, Yang A, Kobata M, Kobayashi K, Verbeeck J, Panaccione G, Dittmann R;, Nanoscale 5, 3954 (2013). http://doi.org/10.1039/c3nr00106g
Abstract: We have investigated the role of the electroforming process in the establishment of resistive switching behaviour for Pt/Ti/Pr0.5Ca0.5MnO3/SrRuO3 layered heterostructures (Pt/Ti/PCMO/SRO) acting as non-volatile Resistance Random Access Memories (RRAMs). Electron spectroscopy measurements demonstrate that the higher resistance state resulting from electroforming of as-prepared devices is strictly correlated with the oxidation of the top electrode Ti layer through field-induced electromigration of oxygen ions. Conversely, PCMO exhibits oxygen depletion and downward change of the chemical potential for both resistive states. Impedance spectroscopy analysis, supported by the detailed knowledge of these effects, provides an accurate model description of the device resistive behaviour. The main contributions to the change of resistance from the as-prepared (low resistance) to the electroformed (high resistance) states are respectively due to reduced PCMO at the boundary with the Ti electrode and to the formation of an anisotropic np junction between the Ti and the PCMO layers.
Keywords: A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Impact Factor: 7.367
Times cited: 40
DOI: 10.1039/c3nr00106g
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“Characterization of black volcanites from the Limay river basin, Patagonia, Argentina, using energy dispersive X-ray fluorescence spectrometry : an aid to infer human group mobility”. Palacios OM, van Meel K, Van Grieken R, Marcó, P L-M, Vázquez C, Journal of radioanalytical and nuclear chemistry 298, 1245 (2013). http://doi.org/10.1007/S10967-013-2600-1
Abstract: The investigation of hunter-gatherers archaeological sites in the Limay river basin, Patagonia, Argentina, raised questions concerning the lithic technology. The chemical characterization of artifacts, rocks and possible sources of provenances could help to elucidate the hunter-gatherer mobility. In three archaeological sitesRincón Chico 2 (RCh2/87; 14C 710 ± 60 BP), Cueva Traful I (CTI; 14C 9430 ± 230 BP) and Casa de Piedra de Ortega (CPO; 14C 2840 ± 80 BP), tools and debitage or discarded flakes made in black volcanic rock have been found. Nearby an extensive rock outcrop of black volcanite, Paso Limay quarry (CPL), with similar characteristics was located. Samples coming from these four sites were analyzed by energy dispersive X-ray fluorescence spectrometry. This characterization allowed the geochemical classification of the lithic material and to correlate the samples with the suspected source after a previous statistical analysis. The majority of the samples were classified as dacites and rhyolites. Only samples coming from CPO site, the closest place to CPL were made exclusively with the quarry rocks. A set of five samples from RCh2/87 and two samples from CTI appear to have same chemical composition as CPL in spite of this site is placed in the opposite bank of the Limay river suggesting that hunter-gatherers could accede to the quarry, eventually. Finally, only a set of five samples coming from RCh2/87 and CTI do not group with the quarry. This fact evidences the existence of secondary sources of supply. The information of this research allowed inferring ancient human mobility patterns in the region.
Keywords: A1 Journal article; Engineering sciences. Technology; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1007/S10967-013-2600-1
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“Characterization and analysis of the adsorption immobilization mechanism of \beta-galactosidase on metal oxide powders”. Satyawali Y, Van Roy S, Roevens A, Meynen V, Mullens S, Jochems P, Doyen W, Cauwenberghs L, Dejonghe W, RSC advances 3, 24054 (2013). http://doi.org/10.1039/C3RA45107K
Abstract: Immobilization of the enzymes plays a vital role in enhancing their applicability in a wide range of applications, thus ensuring the use of sustainable enzymatic processes over the conventional chemical processes on an industrial scale. This study provides the background information for the selection and screening of inorganic metal oxide (MO) powders for their use as fillers in mixed matrix membranes for enzyme immobilization as the future aim. A total of 13 MOs, ranging in size from 0.01 μm to <5 μm, were tested for their performance as a support for enzyme (β-galactosidase) immobilization via adsorption. Alumina appeared to be the best performing MO with the amount and activity of the immobilized enzyme being 64 mg g−1 and up to 288 U g−1, respectively. The amount of immobilized enzyme on alumina (α-Al2O3 C and γ-Al2O3) was >3 times higher than ZrO2 (used as a reference MO in this study). Upon heat treatment at 900 °C, up to 15%, 52% and 42% decline was observed in the amount of immobilized enzyme in case of alumina metal oxides (MOs), ZrO2 and TiO2, respectively. The results suggested that both isoelectric point and surface area of the MO influence the immobilization. The most important observation in this study was that the bonding of the enzyme to the MO surface seems to be mediated by the bonding/interaction of the buffer to the enzyme.
Keywords: A1 Journal article; Laboratory of adsorption and catalysis (LADCA); Sustainable Energy, Air and Water Technology (DuEL)
DOI: 10.1039/C3RA45107K
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Komendová, L (2013) Characteristic length scales and vortex interactions in two-component superconducting systems. Antwerpen
Keywords: Doctoral thesis; Condensed Matter Theory (CMT)
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“Characterisation of hydrous ferric oxides derived from iron-rich groundwaters and their contribution to the suspended sediment of streams”. Baken S, Sjostedt C, Gustafsson JP, Seuntjens P, Desmet N, De Schutter J, Smolders E, Applied geochemistry 39, 59 (2013). http://doi.org/10.1016/J.APGEOCHEM.2013.09.013
Abstract: When Fe(II) bearing groundwaters surface in streams, particulate authigenic Fe-rich material is produced by oxidation. Such freshly precipitated Fe minerals may be transported as suspended sediment and have a profound impact on the fate of trace metals and nutrients in rivers. The objective of this study was to monitor changes in mineralogy and composition of authigenic material from its source to streams of increasing order. Groundwaters, surface waters, and suspended sediment in streams of different order were sampled in the Kleine Nete catchment (Belgium), a lowland with Fe-rich groundwaters (3.5-53.8 mg Fe/L; pH 6.3-6.9). Fresh authigenic material (>0.45 mu m) was produced by oxidising filtered (<0.45 mu m) groundwater and surface water. This material contained, on average, 44% Fe, and smaller concentrations of C, P, and Ca. Iron EXAFS (Extended X-ray Absorption Fine Structure) spectroscopy showed that the Fe was present as poorly crystalline hydrous ferric oxides with a structure similar to that of ferrihydrite. The Fe concentration in the suspended sediment samples decreased to 36-40% (stream order 2), and further to 18-26% (stream order 4 and 5). Conversely, the concentrations of organic C, Ca, Si, and trace metals increased with increasing stream order, suggesting mixing of authigenic material with suspended sediment from a different source. The Fe speciation in the suspended sediment was similar to that in fresh authigenic material, but more Fe-Fe interactions were observed, i.e. it was increasingly hydrolysed, suggesting ageing reactions. The suspended sediment in the streams of order 4 and 5 is estimated to contain between 31% and 59% of authigenic material, but more data are needed to refine this estimate. The authigenic material is an important sink for P in these streams which may alleviate the eutrophication risk in this catchment. (C) 2013 Elsevier Ltd. All rights reserved.
Keywords: A1 Journal article; Sustainable Energy, Air and Water Technology (DuEL)
DOI: 10.1016/J.APGEOCHEM.2013.09.013
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“Cerenkov emission of terahertz acoustic-phonons from graphene”. Zhao CX, Xu W, Peeters FM, Applied physics letters 102, 222101 (2013). http://doi.org/10.1063/1.4808392
Abstract: We present a theoretical study of the electrical generation of acoustic-phonon emission from graphene at room temperature. The drift velocity (v(x)) and temperature of electrons driven by dc electric field (F-x) are determined by solving self-consistently the momentum-and energy-balance equations derived from the Boltzmann equation. We find that in the presence of impurity, acoustic-and optic-phonon scattering, v(x) can be much larger than the longitudinal (v(l)) and transverse (v(t)) sound velocities in graphene even within the linear response regime. As a result, although the acoustic Cerenkov effect cannot be obviously seen in the analytical formulas, the enhanced acoustic-phonon emission can be observed with increasing F-x when v(x) > v(l) and v > v(t). The frequency of acoustic-phonon emission from graphene can be above 10 THz, which is much higher than that generated from conventional semiconductor systems. This study is pertinent to the application of graphene as hypersonic devices such as terahertz sound sources. (C) 2013 AIP Publishing LLC.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.411
Times cited: 25
DOI: 10.1063/1.4808392
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“Cationic clathrate of type-III Ge172-xPxTey (y\approx21,5, x\approx2y) : synthesis, crystal structure and thermoelectric properties”. Kirsanova MA, Mori T, Maruyama S, Abakumov AM, Van Tendeloo G, Olenev A, Shevelkov AV, Inorganic chemistry 52, 8272 (2013). http://doi.org/10.1021/ic401203r
Abstract: A first germanium-based cationic clathrate of type-III, Ge129.3P42.7Te21.53, was synthesized and structurally characterized (space group P42/mnm, a = 19.948(3) Å, c = 10.440(2) Å, Z = 1). In its crystal structure, germanium and phosphorus atoms form three types of polyhedral cages centered with Te atoms. The polyhedra share pentagonal and hexagonal faces to form a 3D framework. Despite the complexity of the crystal structure, the Ge129.3P42.7Te21.53 composition corresponds to the Zintl counting scheme with a good accuracy. Ge129.3P42.7Te21.53 demonstrates semiconducting/insulating behavior of electric resistivity, high positive Seebeck coefficient (500 μV K1 at 300 K), and low thermal conductivity (<0.92 W m1 K1) within the measured temperature range.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 4.857
Times cited: 3
DOI: 10.1021/ic401203r
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“Catheter-associated bloodstream infections in pediatric hematology-oncology patients”. Celebi S, Sezgin ME, Çakir D, Baytan B, Demirkaya M, Sevinir B, Bozdemir SE, Gunes AM, Hacimustafaoglu M, Pediatric Hematology And Oncology 30, 187 (2013). http://doi.org/10.3109/08880018.2013.772683
Abstract: Catheter-associated bloodstream infections (CABSIs) are common complications encountered with cancer treatment. The aims of this study were to analyze the factors associated with recurrent infection and catheter removal in pediatric hematology-oncology patients. All cases of CABSIs in patients attending the Department of Pediatric Hematology-Oncology between January 2008 and December 2010 were reviewed. A total of 44 episodes of CABSIs, including multiple episodes involving the same catheter, were identified in 31 children with cancer. The overall CABSIs rate was 7.4 infections per 1000 central venous catheter (CVC) days. The most frequent organism isolated was coagulase-negative Staphylococcus (CONS). The CVC was removed in nine (20.4%) episodes. We found that hypotension, persistent bacteremia, Candida infection, exit-side infection, neutropenia, and prolonged duration of neutropenia were the factors for catheter removal. There were 23 (52.2%) episodes of recurrence or reinfection. Mortality rate was found to be 9.6% in children with CABSIs. In this study, we found that CABSIs rate was 7.4 infections per 1000 catheter-days. CABSIs rates in our hematology-oncology patients are comparable to prior reports. Because CONS is the most common isolated microorganism in CABSIs, vancomycin can be considered part of the initial empirical regimen.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 1.12
DOI: 10.3109/08880018.2013.772683
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“Casting light on the darkening of colors in historical paintings”. da Pieve F, Hogan C, Lamoen D, Verbeeck J, Vanmeert F, Radepont M, Cotte M, Janssens K, Gonze X, Van Tendeloo G, Physical review letters 111, 208302 (2013). http://doi.org/10.1103/PhysRevLett.111.208302
Abstract: The degradation of colors in historical paintings affects our cultural heritage in both museums and archeological sites. Despite intensive experimental studies, the origin of darkening of one of the most ancient pigments known to humankind, vermilion (α-HgS), remains unexplained. Here, by combining many-body theoretical spectroscopy and high-resolution microscopic x-ray diffraction, we clarify the composition of the damaged paint work and demonstrate possible physicochemical processes, induced by illumination and exposure to humidity and air, that cause photoactivation of the original pigment and the degradation of the secondary minerals. The results suggest a new path for the darkening process which was never considered by previous studies and prompt a critical examination of their findings.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT); AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Impact Factor: 8.462
Times cited: 30
DOI: 10.1103/PhysRevLett.111.208302
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“Bulky knots and links generated by cutting generalized Mobius-Listing bodies and applications in the natural sciences”. Gielis J, Caratelli D, Tavkelidze I, Fougerolle Y, Ricci PE, Gerats T page 167 (2013).
Keywords: H2 Book chapter; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL)
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“Braess paradox at the mesoscopic scale”. de Sousa AA, Chaves A, Farias GA, Peeters FM, Physical review : B : condensed matter and materials physics 88, 245417 (2013). http://doi.org/10.1103/PhysRevB.88.245417
Abstract: We theoretically demonstrate that the transport inefficiency recently found experimentally for branched-out mesoscopic networks can also be observed in a quantum ring of finite width with an attached central horizontal branch. This is done by investigating the time evolution of an electron wave packet in such a system. Our numerical results show that the conductivity of the ring does not necessary improve if one adds an extra channel. This ensures that there exists a quantum analog of the Braess paradox, originating from quantum scattering and interference.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.836
Times cited: 17
DOI: 10.1103/PhysRevB.88.245417
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“Boron nitride mono layer : a strain-tunable nanosensor”. Neek-Amal M, Beheshtian J, Sadeghi A, Michel KH, Peeters FM, The journal of physical chemistry: C : nanomaterials and interfaces 117, 13261 (2013). http://doi.org/10.1021/jp402122c
Abstract: The influence of triaxial in-plane strain on the electronic properties of a hexagonal boron-nitride sheet is investigated using density functional theory. Different from graphene, the triaxial strain localizes the molecular orbitals of the boron-nitride flake in its center depending on the direction of the applied strain. The proposed technique for localizing the molecular orbitals that are close to the Fermi level in the center of boron nitride flakes can be used to actualize engineered nanosensors, for instance, to selectively detect gas molecules. We show that the central part of the strained flake adsorbs polar molecules more strongly as compared with an unstrained sheet.
Keywords: A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT)
Impact Factor: 4.536
Times cited: 38
DOI: 10.1021/jp402122c
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“Biotemplated diatom silica-titania materials for air purification”. Van Eynde E, Tytgat T, Smits M, Verbruggen SW, Hauchecorne B, Lenaerts S, Photochemical &, photobiological sciences 12, 690 (2013). http://doi.org/10.1039/C2PP25229E
Abstract: We present a novel manufacture route for silicatitania photocatalysts using the diatom microalga Pinnularia sp. Diatoms self-assemble into porous silica cell walls, called frustules, with periodic micro-, meso- and macroscale features. This unique hierarchical porous structure of the diatom frustule is used as a biotemplate to incorporate titania by a solgel methodology. Important material characteristics of the modified diatom frustules under study are morphology, crystallinity, surface area, pore size and optical properties. The produced biosilicatitania material is evaluated towards photocatalytic activity for NOx abatement under UV radiation. This research is the first step to obtain sustainable, well-immobilised silicatitania photocatalysts using diatoms.
Keywords: A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL)
Impact Factor: 2.344
Times cited: 18
DOI: 10.1039/C2PP25229E
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