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“Monitoring galvanic replacement through three-dimensional morphological and chemical mapping”. Goris B, Polavarapu L, Bals S, Van Tendeloo G, Liz-Marzán LM, Nano letters 14, 3220 (2014). http://doi.org/10.1021/nl500593j
Abstract: Galvanic replacement reactions on metal nanoparticles are often used for the preparation of hollow nanostructures with tunable porosity and chemical composition, leading to tailored optical and catalytic properties. However, the precise interplay between the three-dimensional (3D) morphology and chemical composition of nanostructures during galvanic replacement is not always well understood as the 3D chemical imaging of nanoscale materials is still challenging. It is especially far from straightforward to obtain detailed information from the inside of hollow nanostructures using electron microscopy techniques such as SEM or TEM. We demonstrate here that a combination of state-of-the-art EDX mapping with electron tomography results in the unambiguous determination of both morphology transformation and elemental composition of nanostructures in 3D, during galvanic replacement of Ag nanocubes. This work provides direct and unambiguous experimental evidence toward understanding the galvanic replacement reaction. In addition, the powerful approach presented here can be applied to a wide range of nanoscale transformation processes, which will undoubtedly guide the development of novel nanostructures.
Keywords: A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Impact Factor: 12.712
Times cited: 120
DOI: 10.1021/nl500593j
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“CoFe nanodumbbells : synthesis, structure, and magnetic properties”. Liakakos N, Gatel C, Blon T, Altantzis T, Lentijo-Mozo S, Garcia-Marcelot C, Lacroix LM, Respaud M, Bals S, Van Tendeloo G, Soulantica K, Nano letters 14, 2747 (2014). http://doi.org/10.1021/nl500734k
Abstract: We report the solution phase synthesis, the structural analysis, and the magnetic properties of hybrid nanostructures combining two magnetic metals. These nano-objects are characterized by a remarkable shape, combining Fe nanocubes on Co nanorods. The topological composition, the orientation relationship, and the growth steps have been studied by advanced electron microscopy techniques, such as HRTEM, electron tomography, and state-of-the-art 3-dimensional elemental mapping by EDX tomography. The soft iron nanocubes behave as easy nucleation centers that induce the magnetization reversal of the entire nanohybrid, leading to a drastic modification of the overall effective magnetic anisotropy.
Keywords: A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Impact Factor: 12.712
Times cited: 27
DOI: 10.1021/nl500734k
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“Computational study of plasma sustainability in radio frequency micro-discharges”. Zhang Y, Jiang W, Zhang QZ, Bogaerts A, Journal of applied physics 115, 193301 (2014). http://doi.org/10.1063/1.4878161
Abstract: We apply an implicit particle-in-cell Monte-Carlo (PIC-MC) method to study a radio-frequency argon microdischarge at steady state in the glow discharge limit, in which the microdischarge is sustained by secondary electron emission from the electrodes. The plasma density, electron energy distribution function (EEDF), and electron temperature are calculated in a wide range of operating conditions, including driving voltage, microdischarge gap, and pressure. Also, the effect of gap size scaling (in the range of 50-1000 μm) on the plasma sustaining voltage and peak electron density at atmospheric pressure is examined, which has not been explored before. In our simulations, three different EEDFs, i.e., a so-called three temperature hybrid mode, a two temperature α mode, and a two temperature γ mode distribution, are identified at different gaps and voltages. The maximum sustaining voltage to avoid a transition from the glow mode to an arc is predicted, as well as the minimum sustaining voltage for a steady glow discharge. Our calculations elucidate that secondary electrons play an essential role in sustaining the discharge, and as a result the relationship between breakdown voltage and gap spacing is far away from the Paschen law at atmospheric pressure.
Keywords: A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Impact Factor: 2.068
Times cited: 11
DOI: 10.1063/1.4878161
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“Shaping electron beams for the generation of innovative measurements in the (S)TEM”. Verbeeck J, Guzzinati G, Clark L, Juchtmans R, Van Boxem R, Tian H, Béché, A, Lubk A, Van Tendeloo G, Comptes rendus : physique 15, 190 (2014). http://doi.org/10.1016/j.crhy.2013.09.014
Abstract: In TEM, a typical goal consists of making a small electron probe in the sample plane in order to obtain high spatial resolution in scanning transmission electron microscopy. In order to do so, the phase of the electron wave is corrected to resemble a spherical wave compensating for aberrations in the magnetic lenses. In this contribution, we discuss the advantage of changing the phase of an electron wave in a specific way in order to obtain fundamentally different electron probes opening up new applications in the (S)TEM. We focus on electron vortex states as a specific family of waves with an azimuthal phase signature and discuss their properties, production and applications. The concepts presented here are rather general and also different classes of probes can be obtained in a similar fashion, showing that electron probes can be tuned to optimize a specific measurement or interaction.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 2.048
Times cited: 22
DOI: 10.1016/j.crhy.2013.09.014
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“Electron mobility in Si delta doped GaAs”. Koenraad PM, van de Stadt AFW, Hai GQ, Shi JM, Vansant P, Peeters FM, Devreese JT, Perenboom JAAJ, Wolter JH, Physica: B : condensed matter 211, 462 (1995). http://doi.org/10.1016/0921-4526(94)01094-H
Keywords: A1 Journal article; Condensed Matter Theory (CMT); Theory of quantum systems and complex systems
Impact Factor: 1.319
Times cited: 9
DOI: 10.1016/0921-4526(94)01094-H
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Verbruggen S (2014) TiO2 gas phase photocatalysis from morphological design to plasmonic enhancement. 173 p
Keywords: Doctoral thesis; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL)
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“Analytical study of the weathering of building stones under field-exposure conditions”. Van Grieken R, Vleugels G, Sweevers E, Dewolfs R, European cultural heritage newsletter on research 8, 2 (1994)
Keywords: A3 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
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“Analysis of biological materials from Tanzania by total reflection X-ray fluorescence (TXRF) analysis”. Koleleni YIA, Van Grieken R, Tanzania journal of science 16, 143 (1990)
Keywords: A3 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
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“Heavy metal distribution in sediments of Krishna River basin, India”. Ramesh R, Subramanian V, Van Grieken R, Environmental geology and water sciences 15, 207 (1990)
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
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“Micro-analysis of individual environmental particles”. Van Grieken R, Artaxo P, Bernard P, Leysen L, Otten P, Storms H, Van Put A, Wouters L, Xhoffer C, Chemia analityczna 35, 75 (1990)
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
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“Aerosol characteristics and sources for the Amazon Basin during the wet season”. Artaxo P, Maenhaut W, Storms H, Van Grieken R, Journal of geophysical research 95, 16971 (1990). http://doi.org/10.1029/JD095ID10P16971
Abstract: As a part of the NASA Global Tropospheric Experiment (GTE), aerosols were sampled in the tropical rain forest of the Amazon Basin during the Amazon Boundary Layer Experiment (ABLE 2B) in April and May 1987, in the wet season, when no forest burning occurs. Fine (dp < 2.0 μm) and coarse (2.0 < dp < 15 μm) aerosol fractions were collected using stacked filter units, at three sites under the forest canopy and at three levels of a tower inside the jungle. Particle-induced X ray emission (PIXE) was used to measure concentrations of 22 elements (Na, Mg, Al, Si, P, S, Cl, K, Ca, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, Br, Rb, Sr, Zr, and Pb). Morphological and trace element measurements of individual particles were carried out by automated electron probe X ray microanalysis. Gravimetric analysis was performed to obtain the fine and coarse aerosol mass concentration. Absolute factor analysis was used to interpret the large data set of the trace element concentrations and to obtain elemental source profiles. Hierarchical cluster analysis was used to derive groups of individual particles. The concentrations of soil dust related elements (Al, Si, Ti, Fe, Mn) were 5 times larger in the wet season compared to the 1985 ABLE 2A dry season experiment. Biogenic aerosol related elements in the fine fraction showed lower concentrations in the wet season. Fine aerosol mass concentration averaged only 2.1±0.7 μg m−3, while the average coarse mass concentration was 6.1±1.8 μg m −3. Sulphur concentrations averaged 76±14 ng m −3 in the fine fraction and 37±9 ng m −3 in the coarse fraction. Biogenic aerosol-related elements were dominant under the forest canopy, while soil dust dominated at the top of the forest canopy. Only two factors explained about 90% of the data variability for the fine and coarse aerosol fractions. These were soil dust (represented mainly by Al, Si, Ti, Mn, and Fe) and biogenic aerosol (represented by K, P, Cl, S, Zn, and the aerosol mass concentration). Source profiles showed a homogeneous aerosol distribution with similar elemental compositions at the different sampling sites. Enrichment factor calculations revealed a soil dust elemental profile similar to the average bulk soil composition, and a biogenic component similar to the plant bulk elemental composition. Total aerosol mass source apportionment showed that biogenic particles account for 5595% of the airborne concentrations. The analysis of individual aerosol particles showed that the biogenic particles consist of leaf fragments, pollen grains, fungi, algae, and other types of particles. Several groups of particles with K, Cl, P, S, and Ca as minor elements could easily be identified as biogenic particles on the basis of their morphology. Considering the vast area of tropical rain forests and the concentrations measured in this work, it is possible that biogenic particles can play an important role in the global aerosol budget and in the global biogeochemical cycles of various elements.
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1029/JD095ID10P16971
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“Phosphorus, calcium and lead distribution in collagen in lead induced soft tissue calcification : an ultrastructural and X-ray microanalytical study”. Vandeputte DF, Jacob WA, Van Grieken RE, Matrix 10, 33 (1990). http://doi.org/10.1016/S0934-8832(11)80135-6
Abstract: Repeated intraperitoneal injections of lead acetate in rats caused a calcification of the skin of the abdomen near the site of the injections. In the lead-induced calcifications, electron dense collagen bundles could be observed. On the surface of the collagen fibrils, needle-like crystals were visible. With energy-dispersive X-ray analysis, phosphorus, calcium and lead were detected in the electron dense collagen bundles. X-ray maps of the P-Kα, Ca-Kα, and Pb-Lα plus Pb-Lβ lines showed an equivalent distribution along the collagen fibrils for phosphorus and calcium. The occurrence of the most electron dense areas in the STEM-image was comparable to the lead distribution. A good correlation existed between the structural and the elemental images of the same area. Although the medicinal use of preparations containing lead is no longer recommended, some are still prescribed. From our results we can conclude that they should not be applied to injured or inflamed skin.
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1016/S0934-8832(11)80135-6
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“Asymptotic expansions in the path integral approach to the bipolaron problem”. Smondyrev MA, Devreese JT, Peeters FM, Physical review : B : condensed matter and materials physics 51, 15008 (1995). http://doi.org/10.1103/PhysRevB.51.15008
Keywords: A1 Journal article; Condensed Matter Theory (CMT); Theory of quantum systems and complex systems
Impact Factor: 3.736
Times cited: 32
DOI: 10.1103/PhysRevB.51.15008
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“Understanding plasma catalysis through modelling and simulation : a review”. Neyts EC, Bogaerts A, Journal of physics: D: applied physics 47, 224010 (2014). http://doi.org/10.1088/0022-3727/47/22/224010
Abstract: Plasma catalysis holds great promise for environmental applications, provided that the process viability can be maximized in terms of energy efficiency and product selectivity. This requires a fundamental understanding of the various processes taking place and especially the mutual interactions between plasma and catalyst. In this review, we therefore first examine the various effects of the plasma on the catalyst and of the catalyst on the plasma that have been described in the literature. Most of these studies are purely experimental. The urgently needed fundamental understanding of the mechanisms underpinning plasma catalysis, however, may also be obtained through modelling and simulation. Therefore, we also provide here an overview of the modelling efforts that have been developed already, on both the atomistic and the macroscale, and we identify the data that can be obtained with these models to illustrate how modelling and simulation may contribute to this field. Last but not least, we also identify future modelling opportunities to obtain a more complete understanding of the various underlying plasma catalytic effects, which is needed to provide a comprehensive picture of plasma catalysis.
Keywords: A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Impact Factor: 2.588
Times cited: 130
DOI: 10.1088/0022-3727/47/22/224010
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“D- states in GaAs/AlxGa1-xAs superlattices in a magnetic field”. Shi JM, Peeters FM, Devreese JT, Physical review : B : condensed matter and materials physics 51, 7714 (1995). http://doi.org/10.1103/PhysRevB.51.7714
Keywords: A1 Journal article; Condensed Matter Theory (CMT); Theory of quantum systems and complex systems
Impact Factor: 3.736
Times cited: 76
DOI: 10.1103/PhysRevB.51.7714
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“Understanding polyethylene surface functionalization by an atmospheric He/O2 plasma through combined experiments and simulations”. Dufour T, Minnebo J, Abou Rich S, Neyts EC, Bogaerts A, Reniers F, Journal of physics: D: applied physics 47, 224007 (2014). http://doi.org/10.1088/0022-3727/47/22/224007
Abstract: High density polyethylene surfaces were exposed to the atmospheric post-discharge of a radiofrequency plasma torch supplied in helium and oxygen. Dynamic water contact angle measurements were performed to evaluate changes in surface hydrophilicity and angle resolved x-ray photoelectron spectroscopy was carried out to identify the functional groups responsible for wettability changes and to study their subsurface depth profiles, up to 9 nm in depth. The reactions leading to the formation of CO, C = O and OC = O groups were simulated by molecular dynamics. These simulations demonstrate that impinging oxygen atoms do not react immediately upon impact but rather remain at or close to the surface before eventually reacting. The simulations also explain the release of gaseous species in the ambient environment as well as the ejection of low molecular weight oxidized materials from the surface.
Keywords: A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Impact Factor: 2.588
Times cited: 13
DOI: 10.1088/0022-3727/47/22/224007
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“Special issue on fundamentals of plasmasurface interactions”. Bogaerts A, Neyts EC, Rousseau A, Journal of physics: D: applied physics 47, 220301 (2014). http://doi.org/10.1088/0022-3727/47/22/220301
Keywords: Editorial; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Impact Factor: 2.588
Times cited: 2
DOI: 10.1088/0022-3727/47/22/220301
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“Self-organized platinum nanoparticles on freestanding graphene”. Xu P, Dong L, Neek-Amal M, Ackerman ML, Yu J, Barber SD, Schoelz JK, Qi D, Xu F, Thibado PM, Peeters FM;, ACS nano 8, 2697 (2014). http://doi.org/10.1021/nn406394f
Abstract: Freestanding graphene membranes were successfully functionalized with platinum nanoparticles (Pt NPs). High-resolution transmission electron microscopy revealed a homogeneous distribution of single-crystal Pt NPs that tend to exhibit a preferred orientation. Unexpectedly, the NPs were also found to be partially exposed to the vacuum with the top Pt surface raised above the graphene substrate, as deduced from atomic-scale scanning tunneling microscopy images and detailed molecular dynamics simulations. Local strain accumulation during the growth process is thought to be the origin of the NP self-organization. These findings are expected to shape future approaches in developing Pt NP catalysts for fuel cells as well as NP-functionalized graphene-based high-performance electronics.
Keywords: A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT)
Impact Factor: 13.942
Times cited: 38
DOI: 10.1021/nn406394f
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“Identification of the ferroelectric switching process and dopant-dependent switching properties in orthorhombic HfO2 : a first principles insight”. Clima S, Wouters DJ, Adelmann C, Schenk T, Schroeder U, Jurczak M, Pourtois G, Applied physics letters 104, 092906 (2014). http://doi.org/10.1063/1.4867975
Abstract: The origin of the ferroelectric polarization switching in orthorhombic HfO2 has been investigated by first principles calculations. The phenomenon can be regarded as being the coordinated displacement of four O ions in the orthorhombic unit cell, which can lead to a saturated polarization as high as 53 mu C/cm(2). We show the correlation between the computed polarization reversal barrier and the experimental coercive fields. (C) 2014 AIP Publishing LLC.
Keywords: A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Impact Factor: 3.411
Times cited: 79
DOI: 10.1063/1.4867975
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“Plasticity mechanisms in ultrafine grained freestanding aluminum thin films revealed by in-situ transmission electron microscopy nanomechanical testing”. Idrissi H, Kobler A, Amin-Ahmadi B, Coulombier M, Galceran M, Raskin J-P, Godet S, Kuebel C, Pardoen T, Schryvers D, Applied physics letters 104, 101903 (2014). http://doi.org/10.1063/1.4868124
Abstract: In-situ bright field transmission electron microscopy (TEM) nanomechanical tensile testing and in-situ automated crystallographic orientation mapping in TEM were combined to unravel the elementary mechanisms controlling the plasticity of ultrafine grained Aluminum freestanding thin films. The characterizations demonstrate that deformation proceeds with a transition from grain rotation to intragranular dislocation glide and starvation plasticity mechanism at about 1% deformation. The grain rotation is not affected by the character of the grain boundaries. No grain growth or twinning is detected. (C) 2014 AIP Publishing LLC.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 3.411
Times cited: 24
DOI: 10.1063/1.4868124
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“Single-file and normal diffusion of magnetic colloids in modulated channels”. Lucena D, Galván Moya JE, Ferreira WP, Peeters FM, Physical review : E : statistical, nonlinear, and soft matter physics 89, 032306 (2014). http://doi.org/10.1103/PhysRevE.89.032306
Abstract: Diffusive properties of interacting magnetic dipoles confined in a parabolic narrow channel and in the presence of a periodic modulated (corrugated) potential along the unconfined direction are studied using Brownian dynamics simulations. We compare our simulation results with the analytical result for the effective diffusion coefficient of a single particle by Festa and d'Agliano [Physica A 90, 229 (1978)] and show the importance of interparticle interaction on the diffusion process. We present results for the diffusion of magnetic dipoles as a function of linear density, strength of the periodic modulation and commensurability factor.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 2.366
Times cited: 5
DOI: 10.1103/PhysRevE.89.032306
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“Quantum rotor in nanostructured superconductors”. Lin S-H, Milošević, MV, Covaci L, Janko B, Peeters FM, Scientific reports 4, 4542 (2014). http://doi.org/10.1038/srep04542
Abstract: Despite its apparent simplicity, the idealized model of a particle constrained to move on a circle has intriguing dynamic properties and immediate experimental relevance. While a rotor is rather easy to set up classically, the quantum regime is harder to realize and investigate. Here we demonstrate that the quantum dynamics of quasiparticles in certain classes of nanostructured superconductors can be mapped onto a quantum rotor. Furthermore, we provide a straightforward experimental procedure to convert this nanoscale superconducting rotor into a regular or inverted quantum pendulum with tunable gravitational field, inertia, and drive. We detail how these novel states can be detected via scanning tunneling spectroscopy. The proposed experiments will provide insights into quantum dynamics and quantum chaos.
Keywords: A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT)
Impact Factor: 4.259
Times cited: 4
DOI: 10.1038/srep04542
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“DFT study of the hyperfine parameters and magnetic properties of ZnO doped with 57Fe”. Abreu Y, Cruz CM, Pinera I, Leyva A, Cabal AE, van Espen P, Solid state communications 185, 25 (2014). http://doi.org/10.1016/J.SSC.2014.01.010
Abstract: Magnetic state of Fe-57 implanted and doped ZnO samples have been reported and studied by Mossbauer spectroscopy at different temperatures. The Mossbauer spectra mainly showed four doublets and three sextets, but some ambiguous identification remains regarding the probe site location and influence of defects in the hyperfine and magnetic parameters. In the present work some possible implantation configurations are suggested and evaluated using Monte Carlo simulation and electronic structure calculations within the density functional theory. Various implantation environments were proposed and studied considering the presence of defects. The obtained Fe-57 hyperfine parameters show a good agreement with the reported experimental values for some of these configurations. The possibility of Fe pair formation, as well as a Zn site vacancy stabilization between he second and third neighborhood of the implantation site, is supported. (C) 2014 Elsevier Ltd. All rights reserved.
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1016/J.SSC.2014.01.010
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“Influence of fixation procedures on the microanalysis of lead-induced intranuclear inclusions in rat kidney”. Vandeputte DF, Jacob WA, Van Grieken RE, The journal of histochemistry and cytochemistry 38, 331 (1990). http://doi.org/10.1177/38.3.2154517
Abstract: Using Laser Microprobe Mass Analysis (LAMMA), we studied the chemical composition of lead-induced intranuclear inclusions in rat kidney tissue prepared by three different wet chemical fixation procedures for transmission electron microscopy. Fixation with glutaraldehyde-Na2S gave the same results as fixation with glutaraldehyde only: a high lead concentration could be detected. Therefore, for lead strongly bound to proteins, precipitation procedures are not essential. Post-fixation with osmium tetroxide drastically changed the composition of the inclusions: the lead concentration decreased substantially, while sodium, calcium, and barium were introduced. The osmium tetroxide fixative was found to be the source of the contamination. It also contained aluminum, and we suggest that other proteins (e.g., in neurofibrillary tangles) might be able to take up Al out of solution and that care must be exercised in interpreting the microanalytical results of osmium-fixed material. For the microanalysis of the lead inclusions, fixation with glutaraldehyde only provides a good compromise between preservation of the ultrastructure and maintenance of the element distribution.
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1177/38.3.2154517
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“Zware metalen in Noordzee- en Schelde-sedimenten”. Van Alsenoy W, Bernard P, Van Grieken R, Wtare 5, 113 (1990)
Keywords: A3 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
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“Kultuurpatrimonium, zure regen en energie”. Van Grieken R, Fobe B, Energie en milieu: tijdschrift over energie en leefmilieu , 10 (1990)
Keywords: A3 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
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“Spectroscopy and ion chromatography to study the effects of air pollution on historical buildings”. Van Grieken R, Roekens E, Sweevers H, Vleugels G, Spectroscopy 10, 70 (1989)
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
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“Dispersal of suspended matter in Makasar Strait and the Flores Basin”. Eisma D, Kalf J, Karmini M, Mook WG, Van Put A, Bernard P, Van Grieken R, Netherlands journal of sea research 24, 383 (1989). http://doi.org/10.1016/0077-7579(89)90116-6
Abstract: In November 1984 in Makasar and the Flores Basin water samples were collected (T, S, dissolved O2, total CO2), bottom samples (sediment composition) and suspended matter (particle composition, particle size). A sediment trap was moored in the Flores Basin at 4600 m depth for nearly four months, covering the dry season. In the Flores Basin there are indications for bottom flow resuspending bottom material or preventing suspended material from settling; in Makasar Strait there is probably inflow of deep water both from the south and from the north, resulting in a very slow bottom water flor. Bottom deposits in Makasar Strait and the Flores Basin are predominantly terrigenous, with an admixture of organic carbonate and silica (mostly coccoliths). Volcanic material is primarily present near to the volcanoes in the south and reaches the deeper basins by slumping. In the suspended matter no volcanic particles and little planktonic material were found, although the latter form 10 to 15% of the top sediment and of the material deposited in the sediment trap. In suspension particles with a large concentration of tin (Sn) were found associated mainly with iron. They probably come from northern Kalimantan or northern Sulawesi. Suspended matter concentrations were mainly less than 0.5 mg·dm−3, only off the Mahakam river mouth were concentrations higher than 1 mg·dm−3. Particle size was erratic because of the variable composition of the coarser particles in suspension. Organic matter concentrations in suspension (in mg·dm−3) roughly follow the distribution of total suspended matter but organic content (in %) of the suspended matter does not show any trends. All organic matter in suspension is of marine origin except in the Mahakam river and estuary. Deposition rates, as estimated from the sediment trap results, are 150 mg·cm−2·a−1 for the total sediment, 26 mg·cm−2·a−1 for carbonate and 13 mg·cm−2·a−1 for organic matter. Flocs and fibres in suspension were only found in and below the Mahakam river plume that reaches ca 400 km from the river mouth to the southeast, and in surface waters associated with plankton (diatoms). The formation of these flocs (broken-up macroflocs or marine snow) is primarily related to particle concentration, turbulence, and the presence of organisms that produce sticky material or glue particles together.
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1016/0077-7579(89)90116-6
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“Characterization of the spheroliths present in primary atypical bandkeratopathy using laser microprobe mass analysis”. Vandeputte DF, Van Grieken RE, Foets BJJ, Misotten L, Biomedical and environmental mass spectrometry 18, 753 (1989). http://doi.org/10.1002/BMS.1200180918
Abstract: Laser microprobe mass analysis was applied to study the chemical composition of spheroliths in the Bowman's membrane of patients suffering from primary atypical bandkeratopathy. The inclusions appear to consist mainly of calcium phosphate.
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1002/BMS.1200180918
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“Penetration of atmospheric aerosols during collection in cellulose filters, studied by secondary ion mass spectrometry”. Rojas CM, Goossens D, Van Grieken R, Journal of aerosol science 20, 569 (1989). http://doi.org/10.1016/0021-8502(89)90103-1
Abstract: The penetration of aerosol particles in a Whatman-41 cellulose filter has been studied via the depth profiles of different elements present in the aerosol. Depth profiles were obtained by analyzing both fine and coarse fractions from a dichotomous sampler by secondary ion mass spectrometry. The fine particles had an aerodynamic diameter dae of less than 2.5 μm, whereas the coarse fraction had 2.5 ≤ dae ≤ 15 μm. Elements such as Al, Si, Ca, Ti and Fe were associated with coarse airborne particles, while S, Cl, Zn, and Br were more abundant in the fine fraction. Results showed that particle size plays an important role in the distribution of particulate matter throughout the filter. SiTi-containing particles were mostly deposited near the surface of the filter, and their profiles can be estimated using a polynomial function, whereas the profile of AlCaFe-containing particles can be approached by an exponential decay function. Elements associated with fine fraction aerosols mainly originating from combustion processes, can penetrate up to about 25% of the total filter thickness, and their profiles are better represented by a diffusion function.
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1016/0021-8502(89)90103-1
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