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“Multi-step loading of titania on mesoporous silica: influence of the morphology and the porosity on the catalytic degradation of aqueous pollutants and VOC's”. de Witte K, Meynen V, Mertens M, Lebedev OI, Van Tendeloo G, Sepúlveda-Escribano A, Rodríguez-Reinoso F, Vansant EF, Cool P, Applied catalysis : B : environmental 84, 125 (2008). http://doi.org/10.1016/j.apcatb.2008.03.015
Abstract: Titania nanoparticles have been deposited on inert porous silica supports with high specific surface area. These materials have potential applications in paint and textile industry as the titania particles selectively deposited on the inner surface of the silica supports act as a photocatalyst. The inert external surface is necessary to avoid photodegradation of the textile material or the paint components. The photocatalytic activity of the catalysts has been evaluated with two catalytic setups. One setup in aqueous phase, for the degradation of dyes such as rhodamine-6G, is commonly used. The second setup is a continuous flow gaseous phase setup which was used for the mineralization of ethanol as a representative volatile organic compound (VOC). The influence of the porosity and the morphology of the silica supports on the photocatalytic activity are discussed.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT); Laboratory of adsorption and catalysis (LADCA)
Impact Factor: 9.446
Times cited: 24
DOI: 10.1016/j.apcatb.2008.03.015
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“Origin of different deactivation of Pd/SnO2 and Pd/GeO2 catalysts in methanol dehydrogenation and reforming: a comparative study”. Lorenz H, Zhao Q, Turner S, Lebedev OI, Van Tendeloo G, Kloetzer B, Rameshan C, Pfaller K, Applied catalysis : A : general 381, 242 (2010). http://doi.org/10.1016/j.apcata.2010.04.015
Abstract: Pd particles supported on SnO2 and GeO2 have been structurally investigated by X-ray diffraction, (High-Resolution) transmission and scanning electron microscopy after different reductive treatments to monitor the eventual formation of bimetallic phases and catalytically tested in methanol dehydrogenation/ reforming. For both oxides this included a thin film sample with well-defined Pd particles and a powder catalyst prepared by incipient wetness impregnation. The hexagonal and the tetragonal polymorph were studied for powder GeO2. Pd2Ge formation was observed on all GeO2-supported catalysts, strongly depending on the specific sample used. Reduction of the thin film at 573K resulted in full transformation into the bimetallic state. The partial solubility of hexagonal GeO2 in water and its thermal structural instability yielded Pd2Ge formation at 473 K, at the cost of a structurally inhomogeneous support and Ge metal formation at higher reduction temperatures. Pd on tetragonal GeO2 entered a state of strong metalsupport interaction after reduction at 573673 K, resulting in coalescing Pd2Ge particles on a sintered and re-crystallized support, apparently partially covering the bimetallic particles and decreasing the catalytic activity. Pd2Ge on amorphous thin film and hexagonal GeO2 converted methanol primarily via dehydrogenation to CO and H2. At 573 K, formation of Pd2Sn and also PdSn occurred on the Pd/SnO2 thin film. Pd3Sn2 (and to some extent Pd2Sn) were predominantly obtained on the respective powder catalyst. Strong deactivation with increasing reduction temperature was observed, likely not based on the classical strong metalsupport interaction effect, but rather on a combination of missing active structural ensembles on Sn-enriched bimetallic phases and the formation of metallic -Sn. Correlations to Pd and its bimetallics supported on ZnO, Ga2O3 and In2O3 were also discussed.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 4.339
Times cited: 14
DOI: 10.1016/j.apcata.2010.04.015
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“Preparation of sulfonated ordered mesoporous carbon and its use for the esterification of fatty acids”. Peng L, Philippaerts A, Ke X, van Noyen J, de Cleppel F, Van Tendeloo G, Jacobs PA, Sels BF, Catalysis today 150, 140 (2010). http://doi.org/10.1016/j.cattod.2009.07.066
Abstract: Mesoporous carbon, which can be replicated from mesoporous silica and whose surface is hydrophobic, can be an ideal catalyst for the esterification of fatty acids. Here we report an easy and low cost way to prepare sulfonic acid group-functionalized mesoporous carbon. A sample of calcined mesoporous silica SBA-15 was added to an aqueous sucrose solution followed by drying and calcination at different temperatures. In contrast to existing procedures, the obtained hybrid Si/C material was then first sulfonated in H2SO4, before the final removal of the silica template in order to stabilize the porous structure towards the liquid phase sulfonation treatment. Thus the silicacarbon composites, instead of the mesoporous carbon, were successfully sulfonated to introduce SO3H groups, while keeping the ordered mesoporous structure intact. The influence of carbonization temperature was investigated, suggesting an optimum temperature of 873 K. The SO3H group-functionalized mesoporous carbon, denoted as CMK-3-873-SO3H, was characterized by means of XRD, N2 physisorption, SEM, FT-IR, elemental analysis and TEM. It followed that a uniform mesoporous carbon was obtained with an average pore size of 3.89 nm, a specific surface of 807 m2/g and a SO3H group loading of 0.39 meq/g of dry material. Compared with other solid acid catalysts, the resulting material shows enhanced activity in the acid-catalyzed esterification of oleic acid with methanol, and can be used repeatedly. The increased catalytic performance is attributed to the hydrophobic surface and larger pore size of the new catalyst. It can effectively accommodate long chain fatty acids and reject formed water, making the active sites easily accessible.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 4.636
Times cited: 132
DOI: 10.1016/j.cattod.2009.07.066
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“Quantum transport in an ultra-thin SOI MOSFET: influence of the channel thickness on the I-V characteristics”. Croitoru MD, Gladilin VN, Fomin VM, Devreese JT, Magnus W, Schoenmaker W, Sorée B, Solid state communications 147, 31 (2008). http://doi.org/10.1016/j.ssc.2008.04.025
Keywords: A1 Journal article; Theory of quantum systems and complex systems; Condensed Matter Theory (CMT); Electron microscopy for materials research (EMAT)
Impact Factor: 1.554
Times cited: 8
DOI: 10.1016/j.ssc.2008.04.025
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“Structure of multi-grain spherical particles in an amorphous Ti50Ni25Cu25 melt-spun ribbon”. Santamarta R, Schryvers D, Materials science and engineering: part A: structural materials: properties, microstructure and processing 378, 143 (2004). http://doi.org/10.1016/j.msea.2003.11.060
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 3.094
Times cited: 5
DOI: 10.1016/j.msea.2003.11.060
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“Pd-In2O3 interaction due to reduction in hydrogen: consequences for methanol steam reforming”. Lorenz H, Turner S, Lebedev OI, Van Tendeloo G, Klötzer B, Rameshan C, Pfaller K, Penner S, Applied catalysis : A : general 374, 180 (2010). http://doi.org/10.1016/j.apcata.2009.12.007
Abstract: Two different Pd/In2O3 samples including a thin film model catalyst with well-defined Pd particles grown on NaCl(0 0 1) supports and a powder catalyst prepared by an impregnation technique are examined by electron microscopy, X-ray diffraction and catalytic measurements in methanol steam reforming in order to correlate the formation of different oxide-supported bimetallic PdIn phases with catalytic activity and selectivity. A PdIn shell around the Pd particles is observed on the thin film catalyst after embedding the Pd particles in In2O3 at 300 K, likely because alloying to PdIn and oxidation to In2O3 are competing processes. Increased PdIn bimetallic formation is observed up to 573 K reduction temperature until at 623 K the film stability limit in hydrogen is reached. Oxidative treatments at 573 K lead to decomposition of PdIn and to the formation of an In2O3 shell covering the Pd particles, which irreversibly changes the activity and selectivity pattern to clean In2O3. PdIn and Pd2In3 phases are obtained on the powder catalyst after reduction at 573 K and 673 K, respectively. Only CO2-selective methanol steam reforming is observed in the reduction temperature range between 473 K and 573 K. After reduction at 673 K encapsulation of the bimetallic particles by crystalline In2O3 suppresses CO2 formation and only activity and selectivity of clean In2O3 are measured.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 4.339
Times cited: 55
DOI: 10.1016/j.apcata.2009.12.007
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“Two phase intergrowth in Bi2Sr2Ca0.6Y0.4Cu2Oy single crystals”. Zhang XF, Van Tendeloo G, Ge SL, Emmen JHPM, Brabers VAM, Physica: C : superconductivity 215, 39 (1993). http://doi.org/10.1016/0921-4534(93)90362-T
Abstract: In Bi2Sr2Ca0.6Y0.4Cu2Oy single crystals we have identified the intergrowth of two phases; a normal Bi2Sr2CaCu2Oy type phase with a 4.6b modulation period and a secondary,phase with a 9.4b modulation period. Both the two phases have orthorhombic basic structures with similar lattice parameters but different symmetries, i.e. Bbmb for the normal phase and Ccca for the secondary phase. The c-parameters of these two phases are found to vary independently upon changing the nominal Y content. The modulation characteristics of the secondary phase implies a close structural relation between the two phases. Both phases are discussed from a structural and a compositional point of view.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 0.942
Times cited: 17
DOI: 10.1016/0921-4534(93)90362-T
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“Unexpected ordering behaviour of Pt3Al intermetallic precipitates”. Douglas A, Neethling JH, Santamarta R, Schryvers D, Cornish LA, Journal of alloys and compounds 432, 96 (2007). http://doi.org/10.1016/j.jallcom.2006.05.106
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 3.133
Times cited: 18
DOI: 10.1016/j.jallcom.2006.05.106
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“Analytical model of the enhanced light transmission through subwavelength metal slits: Green's function formalism versus Rayleigh's expansion”. Kukhlevsky SV, Mechler M, Samek O, Janssens K, Applied physics B : lasers and optics 84, 19 (2006). http://doi.org/10.1007/S00340-006-2272-4
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Impact Factor: 1.696
Times cited: 7
DOI: 10.1007/S00340-006-2272-4
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“Carbonates from the lower part of transition zone or even the lower mantle”. Brenker FE, Vollmer C, Vincze L, Vekemans B, Szymanski A, Janssens K, Szaloki I, Nasdala L, Joswig W, Kaminsky F, Earth and planetary science letters 260, 1 (2007). http://doi.org/10.1016/J.EPSL.2007.02.038
Abstract: Effective CO2-storage in the shallow solid Earth mainly occurs by the formation of carbonates. Although the possibility of transport and storage of carbonates to great depth is demonstrated experimentally, ultra-deep mantle carbonates have not been found before. Applying several in situ analytical techniques on inclusions in diamonds from Juina (Brazil) originating from the lower part of the transition zone (> 580 km) or even the lower mantle (> 670 km), reveal the existence of deep Earth carbonates. These finding unquestionably show that at least locally carbonates exist within the deep Earth and may indicate that the Earth's global CO2-cycle has an ultra-deep extension.
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Impact Factor: 4.409
Times cited: 156
DOI: 10.1016/J.EPSL.2007.02.038
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“Trace element fingerprinting of façon-de-Venise glass”. Šmit Ž, Bulska E, Janssens K, Bulska E, Wagner B, Kos M, Lazar I, Nuclear instruments and methods in physics research: B: beam interactions with materials and atoms 239, 94 (2005). http://doi.org/10.1016/J.NIMB.2005.06.182
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Impact Factor: 1.109
Times cited: 27
DOI: 10.1016/J.NIMB.2005.06.182
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“Development, performance and stability of sulfur-free, macrovoid-free BSCF capillaries for high temperature oxygen separation from air”. Buysse C, Kovalevsky A, Snijkers F, Buekenhoudt A, Mullens S, Luyten J, Kretzschmar J, Lenaerts S, Journal of membrane science 372, 239 (2011). http://doi.org/10.1016/J.MEMSCI.2011.02.011
Abstract: Capture and storage of CO2 (CCS) from fossil-fuel power plants is vital in order to counteract a pending anthropogenic global warming. High temperature oxygen transport perovskite membranes can fulfill an important role in the separation of oxygen from air needed in the oxy-fuel technologies for CCS. In this study we present the development, performance and stability of gastight, macrovoid-free and sulfur-free Ba0.5Sr0.5Co0.8Fe0.2O3 − δ (BSCF) mixed conductor capillary membranes prepared by phase-inversion spinning and sintering. A sulfur-free phase-inversion polymer was chosen in order to obtain a phase-pure BSCF crystal phase. Special attention was given to the polymer solution and ceramic spinning suspension in order to avoid macrovoids and achieve gastight membranes. The sulfur-free BSCF capillaries showed an average 4-point bending strength of 64 ± 8 MPa and a maximum oxygen flux of not, vert, similar5.3 Nml/(cm2 min) at 950 °C for an argon sweep flow rate of 125 Nml/min. The comparison of the performance of sulfur-free and sulfur-containing BSCF capillaries with similar dimensions revealed a profound impact of the sulfur contamination on both the oxygen flux and the activation energy of the overall oxygen transport mechanism. Both long-term oxygen permeation at different temperatures and post-operation analysis of a sulfur-free BSCF capillary were performed and discussed.
Keywords: A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL)
Impact Factor: 6.035
Times cited: 32
DOI: 10.1016/J.MEMSCI.2011.02.011
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“Oxygen exchange-limited transport and surface activation of Ba0.5Sr0.5Co0.8Fe0.2O3-\delta capillary membranes”. Kovalevsky A, Buysse C, Snijkers F, Buekenhoudt A, Luyten J, Kretzschmar J, Lenaerts S, Journal of membrane science 368, 223 (2011). http://doi.org/10.1016/J.MEMSCI.2010.11.034
Abstract: Analysis of oxygen permeation fluxes through Ba0.5Sr0.5Co0.8Fe0.2O3−δ (BSCF) capillary membranes, fabricated via a phase-inversion spinning technique using polysulfone as binder, showed a significant limiting role of the surface-oxygen exchange kinetics. Within the studied temperature and oxygen partial pressure ranges, the activation of core and shell sides of the BSCF capillary with praseodymium oxide (PrOx) resulted in an increase in permeation rate of about 300%. At 11231223 K the activated BSCF membranes demonstrate almost 3-times lower activation energies for the overall oxygen transport (not, vert, similar35 kJ/mol) than the non-activated capillaries, indicating that the mechanism of oxygen transport through the activated capillaries becomes significantly controlled by bulk diffusion limitations, allowing further improvement of the overall performance by decreasing the wall thickness. XRD, EDS and EPMA studies revealed the formation of (Pr,Ba,Sr)(Co,Fe)O3−δ perovskite-type oxides on the surface of the PrOx-modified membranes, which may be responsible for the drastic increase in oxygen exchange rate. At T > 1123 K both non-activated and activated Ba0.5Sr0.5Co0.8Fe0.2O3−δ membranes demonstrate stable performance with time, while at 1073 K only a small initial decrease in permeation was observed.
Keywords: A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL)
Impact Factor: 6.035
Times cited: 21
DOI: 10.1016/J.MEMSCI.2010.11.034
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“Photocatalytic degradation of ethylene : an FTIR in situ study under atmospheric conditions”. Hauchecorne B, Tytgat T, Verbruggen SW, Hauchecorne D, Terrens D, Smits M, Vinken K, Lenaerts S, Applied catalysis : B : environmental 105, 111 (2011). http://doi.org/10.1016/J.APCATB.2011.03.041
Abstract: In this paper, the reaction mechanism of the photocatalytic oxidation of ethylene is elucidated by means of an in-house developed FTIR in situ reactor. This reactor allowed us to look at the catalytic surface at the moment the reactions actually occur. This new approach gave some exciting new insights in how ethylene is photocatalytically oxidised. It was found that there is a change in dipole moment of the ethylene molecule when it is brought in the neighbourhood of the catalyst. From this finding, a hypothesis was formulated on how the CC-bond from ethylene will break. It was found that the aforementioned interaction between the catalyst and the molecule, allows the excited electrons from the UV irradiated catalyst to occupy the lowest unoccupied molecular orbital (LUMO) of the ethylene molecule through a process known as backdonation. Following this hypothesis, it was found that the degradation occurs through the formation of two intermediates: formaldehyde and formic acid, for which formaldehyde is bound in two different ways (coordinatively and as bidentate). Finally CO2 and H2O are found as end products, resulting in the complete mineralisation of the pollutant.
Keywords: A1 Journal article; Engineering sciences. Technology; Molecular Spectroscopy (MolSpec); Sustainable Energy, Air and Water Technology (DuEL)
Impact Factor: 9.446
Times cited: 29
DOI: 10.1016/J.APCATB.2011.03.041
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“Combined XRD, EPMA and X-ray absorption study of mineral ilmenite used in pigments production”. Klepka M, Lawniczak-Jablonska K, Jablonski M, Wolska A, Minikayev R, Paszkowicz W, Przepiera A, Spolnik Z, Van Grieken R, Journal of alloys and compounds 401, 281 (2005). http://doi.org/10.1016/J.JALLCOM.2005.02.047
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1016/J.JALLCOM.2005.02.047
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“Chemical and structural analysis of etching residue layers in semiconductor devices with energy filtering transmission electron microscopy”. Hens S, van Landuyt J, Bender H, Boullart W, Vanhaelemeersch S, Materials science in semiconductor processing 4, 109 (2001). http://doi.org/10.1016/S1369-8001(00)00147-5
Abstract: The use of an energy-filtering held emission gun transmission electron microscope (CM30 FEG Ultratwin) allows, apart from imaging morphologies down to nanometer scale, the fast acquisition of high-resolution element distributions. Electrons that have lost energy corresponding to characteristic inner-shell loss edges are used to form the element maps. The production of Ultra Large-Scale Integration (ULSI) devices with dimensions below 0.25 mum requires among others the formation of a multilayer metallization scheme by means of repeatedly applying the deposition and etching of dielectrics and metals. In this work the evolution of the surface chemical species on etched Al lines in a post-etch cleaning process has been investigated by energy filtering transmission electron microscopy, with the aim to understand the role of each process step on the removal of the etching residues. (C) 2001 Elsevier Science Ltd. All rights reserved.
Keywords: A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Impact Factor: 2.359
DOI: 10.1016/S1369-8001(00)00147-5
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“Development of photocatalytic efficient Ti-based nanotubes and nanoribbons by conventional and microwave assisted synthesis strategies”. Ribbens S, Meynen V, Van Tendeloo G, Ke X, Mertens M, Maes BUW, Cool P, Vansant EF, Microporous and mesoporous materials: zeolites, clays, carbons and related materials 114, 401 (2008). http://doi.org/10.1016/j.micromeso.2008.01.028
Abstract: Titanate nanotubes were prepared via a hydrothermal treatment of TiO2 powders (Riedel De Haen) in a basic solution. Morphology and structure of the prepared samples were characterized by high resolution transmission electron microscopy (HRTEM), selected area electron diffraction (SAED), XRD, FT-Raman spectroscopy, nitrogen sorption and DSC. The photocatalytic activity was evaluated by photocatalytic oxidation of rhodamine 6G. Trititanate nanotubes (TTNT) with inner pore diameters between 4 and 4.2 nm and surface areas up till 360 m(2)/g could be synthesized. The synthesis route was modified by introduction of a calcination step, by applying a lower hydrothermal temperature and microwave irradiation in order to increase the photocatalytic activity of the porous photoactive nanotubular materials. Calcination and a softer hydrothermal treatment led to the formation of anatase without affecting the surface area and nanotubular shape of the samples. In this way, the photocatalytic activity of the original trititanate nanotubes could be significantly increased. By making use of microwave assisted synthesis, the photocatalytic activity call also be increased due to the presence of anatase. However, by applying microwave synthesis, a different structure was obtained, nanoribbons (NR) instead of nanotubcs, resulting in a decrease in surface area and porosity.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT); Laboratory of adsorption and catalysis (LADCA); Organic synthesis (ORSY)
Impact Factor: 3.615
Times cited: 47
DOI: 10.1016/j.micromeso.2008.01.028
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“Graphitic nanocrystals inside the pores of mesoporous silica : synthesis, characterization and an adsorption study”. de Clippel F, Harkiolakis A, Vosch T, Ke X, Giebeler L, Oswald S, Houthoofd K, Jammaer J, Van Tendeloo G, Martens JA, Jacobs PA, Baron GV, Sels BF, Denayer JFM, Microporous and mesoporous materials: zeolites, clays, carbons and related materials 144, 120 (2011). http://doi.org/10.1016/j.micromeso.2011.04.003
Abstract: This work presents a new carbonsilica hybrid material, denoted as CSM, with remarkable sorption properties. It consists of intraporous graphitic nanocrystals grown in the pores of mesoporous silica. CSM is obtained by a subtle incipient wetness impregnation of Al-containing mesoporous silica with furfuryl alcohol (FA)/hemelitol solutions. Both the volume match of the impregnation solution with that of the silica template pore volume, and the presence of Al3+ in the silica, are crucial to polymerize FA selectively inside the mesopores. Carbonization of the intraporous polymer was then performed by pyrolysis under He up to 1273 K. The resulting CSMs were examined by SEM, HRTEM, 27Al MAS NMR, N2 adsorption, XRD, TGA, TPD, XPS, pycnometry and Raman spectroscopy. Mildly oxidized graphitic-like carbon nanoblocks, consisting of a few graphene-like sheets, were thus identified inside the template mesopores. Random stacking of these carbon crystallites generates microporosity resulting in biporous materials at low carbon content and microporous materials at high carbon loadings. Very narrow pore distributions were obtained when pyrolysis was carried out under slow heating rate, viz. 1 K min−1. Adsorption and shape selective properties of the carbon filled mesoporous silica were studied by performing pulse chromatography and breakthrough experiments, and by measuring adsorption isotherms of linear and branched alkanes. Whereas the parent mesoporous silica shows unselective adsorption, their CSM analogues preferentially adsorb linear alkanes. The sorption capacity and selectivity can be adjusted by changing the pore size of the template or by varying the synthesis conditions. A relation between the carbon crystallites size and the shape selective behaviour of the corresponding CSM for instance is demonstrated. Most interestingly, CSM shows separation factors for linear and branched alkanes up to values comparable to those of zeolitic molecular sieves.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 3.615
Times cited: 15
DOI: 10.1016/j.micromeso.2011.04.003
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“LPE growth and characterization of InGaAsP/InP heterostructures: IR-emitting diodes at 1.66 μm: application to the remote monitoring of methane gas”. Volkov VV, van Landuyt J, Marushkin K, Gijbels R, Férauge C, Vasilyev MG, Shelyakin AA, Sokolovsky AA, Sensors and actuators : A : physical 62, 624 (1997). http://doi.org/10.1016/S0924-4247(97)01377-0
Abstract: Highly effective IR light-emitting diodes operating at the wavelength 1.66 mu m and based on the buried heterostructure In0.88Ga0.12As0.26P0.74/ In0.72Ga0.28As0.62P0.38/In0.53Ga0.47As/InP have been grown by liquid-phase epitaxy (LPE) and characterized in detail by means of transmission electron microscopy (TEM), high-resolution electron microscopy (HREM),electron diffraction (ED), X-ray diffraction (XRD), secondary-ion mass spectrometry (SIMS) and electroluminescence measurements. The InGaAsP epilayers are found to be well lattice matched and of good structural quality. A tentative explanation is presented for the spinodal decomposition observed in InGaAsP alloys. A new type of selective CK, gas sensor has been developed and fabricated an the basis of the IR light-emitting diode mentioned above. Especially designed for the remote control of CH4 gas via fibre optics, an integrated optoelectronic readout scheme has been developed and tested, It is shown that the proposed type of sensor can be used for the quantitative remote control of CH4 gas concentration (0.2-100%) via a fibre glass line up to a distance of 2 x 1 km. (C) 1997 Elsevier Science S.A.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT); Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Impact Factor: 2.499
Times cited: 3
DOI: 10.1016/S0924-4247(97)01377-0
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“Quantized conductance without reservoirs : method of the nonequilibrium statistical operator”. Sorée B, Magnus W, Journal of computational electronics 6, 255 (2007). http://doi.org/10.1007/s10825-006-0094-6
Abstract: We introduce a generalized non-equilibrium statistical operator (NSO) to study a current-carrying system. The NSO is used to derive a set of quantum kinetic equations based on quantum mechanical balance equations. The quantum kinetic equations are solved self-consistently together with Poissons equation to solve a general transport problem. We show that these kinetic equations can be used to rederive the Landauer formula for the conductance of a quantum point contact, without any reference to reservoirs at different chemical potentials. Instead, energy dissipation is taken into account explicitly through the electron-phonon interaction. We find that both elastic and inelastic scattering are necessary to obtain the Landauer conductance.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 1.526
DOI: 10.1007/s10825-006-0094-6
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“Synthesis and characterization of the new cyclosilicate hydrate (hexamethyleneimine)4.[Si8O16(OH)4].12H2O”. Verlooy PLH, Robeyns K, van Meervelt L, Lebedev OI, Van Tendeloo G, Martens JA, Kirschhock CEA, Microporous and mesoporous materials: zeolites, clays, carbons and related materials 130, 14 (2010). http://doi.org/10.1016/j.micromeso.2009.10.006
Abstract: A new cyclosilicate hydrate with composition (C6H14N)4·[Si8O16(OH)4]·12H2O was crystallized and the structure determined by single-crystal X-ray diffraction. The structure, described by the tetragonal space group I41/a, with unit cell dimensions of a = 39.2150(2) Å and c = 14.1553(2) Å, contains columns of hydrogen-bonded cubic octamer silicate anions. The space between silicate columns holds hydrogen-bonded water and protonated hexamethyleneimine molecules compensating the negative charge of the silicate. The crystal water can be removed resulting in a rearrangement of the columns into orthorhombic symmetry. Removal of the organic moiety causes amorphisation. Flash evacuation results in a new microporous material with pore volumes typical of a zeolite.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 3.615
Times cited: 5
DOI: 10.1016/j.micromeso.2009.10.006
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“Cu(OH)2 nanowires, CuO nanowires and CuO nanobelts”. Du GH, Van Tendeloo G, Chemical physics letters 393, 64 (2004). http://doi.org/10.1016/j.cplett.2004.06.017
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 1.815
Times cited: 145
DOI: 10.1016/j.cplett.2004.06.017
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“The use of convergent beam electron diffraction for stress measurements in shallow trench isolation structures”. Stuer C, van Landuyt J, Bender H, Rooyackers R, Badenes G, Materials science in semiconductor processing 4, 117 (2001). http://doi.org/10.1016/S1369-8001(00)00110-4
Abstract: Shallow trench isolation (STI) is a promising technology for the isolation structures of the new generation of ULSI devices with dimensions below 0.18 mum. The various processing steps cause stress fields in STI structures, which can lead to defect formation in the silicon substrate. In their turn, stress fields affect the electrical parameters and the reliability of devices. Convergent beam electron diffraction (CBED) is used in this study to examine the influence of a wet and a dry pre-gate oxidation on the stress distribution around STI structures. The measurements are performed on STI structures with different width and spacing. CBED analysis is compared with bright-field TEM images. Defects are observed in high-strain areas of small isolated structures. (C) 2001 Elsevier Science Ltd. All rights reserved.
Keywords: A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Impact Factor: 2.359
Times cited: 6
DOI: 10.1016/S1369-8001(00)00110-4
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“Thermal behavior of Si-doped fullerenes vs their structural stability at T = 0 K : a density functional study”. Scipioni R, Matsubara M, Ruiz E, Massobrio C, Boero M, Chemical physics letters 510, 14 (2011). http://doi.org/10.1016/j.cplett.2011.05.019
Abstract: We establish the topological conditions underlying the thermal stability of C30Si30 clusters. Two topologies have been considered: a segregated one, where Si and C atoms lie on neighboring and yet, separated parts of the cage, and a non-segregated one, where the number of SiC bonds is maximized. The segregated network is energetically favored against the non-segregated one, both structures being fully relaxed at T = 0 K. Conversely, the non-segregated structure is the only one stable at finite temperatures, regardless of the nature of the local states (d or p) included in the KleynmanBylander construction.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 1.815
Times cited: 14
DOI: 10.1016/j.cplett.2011.05.019
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“Zn-Al layered double hydroxides: synthesis, characterization and photocatalytic application”. Seftel EM, Popovici E, Mertens M, de Witte K, Van Tendeloo G, Cool P, Vansant EF, Microporous and mesoporous materials: zeolites, clays, carbons and related materials 113, 296 (2008). http://doi.org/10.1016/j.micromeso.2007.11.029
Keywords: A1 Journal article; Laboratory of adsorption and catalysis (LADCA); Electron microscopy for materials research (EMAT)
Impact Factor: 3.615
Times cited: 154
DOI: 10.1016/j.micromeso.2007.11.029
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“On the concept of a supervisory, fuzzy set logic based, advanced filtration control in membrane bioreactors”. Brauns E, van Hoof E, Huyskens C, de Wever H, Desalination and water treatment 29, 119 (2011). http://doi.org/10.5004/DWT.2011.2258
Abstract: The filtration process within a membrane bioreactor (MBR) is mostly controlled in a classic way through typical set-points such as aeration flow rate, filtration duration, backwash frequency or relaxation duration. The values of these filtration set-points result from experience and remain often unchanged during the installations operational lifetime. Filtration is dictated considerably by membrane fouling phenomena. The fouling potential of the mixed liquor however can significantly fluctuate, even daily, from changing influent characteristics. Fixed set-point values thus may represent sub-optimal filtration conditions. Consequently, a supervising advanced control system, being able to continuously adapt the set-points values would be beneficial regarding the MBR filtration process optimization. Such optimization could reduce the corresponding MBR energy consumption, e.g. linked to the filtration related membrane aeration. An Advanced Control System (ACS) based on Fuzzy Set Logic (FSL) is introduced here, enabling to supervise an existing classic membrane filtration control system. Such ACS is able to daily (or even more frequent) optimize the set-points of the underlying classic control system, from the input of various sensor and process parameter values. The theoretical background and practical implementation of the FSL based ACS concept is explained.
Keywords: A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL)
DOI: 10.5004/DWT.2011.2258
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“Radiation dose estimation and mass attenuation coefficients of cement samples used in Turkey”. Damla N, Čevik U, Kobya AI, Celik A, Celik N, Van Grieken R, Journal of hazardous materials 176, 644 (2010). http://doi.org/10.1016/J.JHAZMAT.2009.11.080
Abstract: Different cement samples commonly used in building construction in Turkey have been analyzed for natural radioactivity using gamma-ray spectrometry. The mean activity concentrations observed in the cement samples were 52, 40 and 324 Bq kg−1 for 226Ra, 232Th and 40K, respectively. The measured activity concentrations for these radionuclides were compared with the reported data of other countries and world average limits. The radiological hazard parameters such as radium equivalent activities (Raeq), gamma index (Iγ) and alpha index (Iα) indices as well as terrestrial absorbed dose and annual effective dose rate were calculated and compared with the international data. The Raeq values of cement are lower than the limit of 370 Bq kg−1, equivalent to a gamma dose of 1.5 mSv y−1. Moreover, the mass attenuation coefficients were determined experimentally and calculated theoretically using XCOM in some cement samples. Also, chemical compositions analyses of the cement samples were investigated.
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1016/J.JHAZMAT.2009.11.080
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“Giant vortices in small mesoscopic disks : an approximate description”. Yampolskii SV, Peeters FM, Physica: C : superconductivity 369, 347 (2002). http://doi.org/10.1016/S0921-4534(01)01274-6
Abstract: We present an approximate description of the giant vortex state in a thin mesoscopic superconducting disk within the phenomenological Ginzburg-Landau approach. Analytical asymptotic expressions for the energies of the states with fixed vorticity are obtained when a small magnetic flux is accumulated in the disk. The spectrum of the lowest Landau levels of such a disk is also discussed. (C) 2001 Elsevier Science B.V. All rights reserved.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 1.404
DOI: 10.1016/S0921-4534(01)01274-6
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“Magnetic coupling between mesoscopic superconducting rings”. Baelus BJ, Yampolskii SV, Peeters FM, Physica: C : superconductivity 369, 366 (2002). http://doi.org/10.1016/S0921-4534(01)01278-3
Abstract: Using the nonlinear Ginzburg-Landau theory we investigated the dependence of the magnetic coupling between two concentric mesoscopic superconducting rings on their thickness. The size of this magnetic coupling increases with the thickness of the rings. (C) 2001 Elsevier Science B.V. All rights reserved.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 1.404
Times cited: 1
DOI: 10.1016/S0921-4534(01)01278-3
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“Quenching of the Hall effect in localised high magnetic field regions”. Novoselov KS, Geim AK, Dubonos SV, Cornelissens YG, Peeters FM, Maan JC, Physica. E: Low-dimensional systems and nanostructures 12, 244 (2002). http://doi.org/10.1016/S1386-9477(01)00364-2
Abstract: We report the suppression of the Hall effect in a mesoscopic Hall cross with a strong magnetic field only in the centre and vanishingly small outside, The local magnetic field is produced by placing Dy pillar on top of a structure with a high-mobility two-dimensional electron gas. The effect is found to be due to a sharp increase of the number of back-scattered and quasi-localised electron orbits. The possibility of localising electrons inside the magnetic inhomogeneity region is discussed. (C) 2002 Elsevier Science B.V. All rights reserved.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 2.221
Times cited: 3
DOI: 10.1016/S1386-9477(01)00364-2
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