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“Beauty is skin deep : the skin tones of Vermeer's Girl with a Pearl Earring”. van Loon A, Vandivere A, Delaney JK, Dooley KA, De Meyer S, Vanmeert F, Gonzalez V, Janssens K, Leonhardt E, Haswell R, de Groot S, D'Imporzano P, Davies GR, Heritage science 7, 102 (2019). http://doi.org/10.1186/S40494-019-0344-0
Abstract: The soft modelling of the skin tones in Vermeer's Girl with a Pearl Earring (Mauritshuis) has been remarked upon by art historians, and is their main argument to date this painting to c. 1665. This paper describes the materials and techniques Vermeer used to accomplish the smooth flesh tones and facial features of the Girl, which were investigated as part of the 2018 Girl in the Spotlight research project. It combines macroscopic X-ray fluorescence imaging (MA-XRF), reflectance imaging spectroscopy (RIS), and 3D digital microscopy. Vermeer built up the face, beginning with distinct areas of light and dark. He then smoothly blended the final layers to create almost seamless transitions. The combination of advanced imaging techniques highlighted that Vermeer built the soft contour around her face by leaving a 'gap' between the background and the skin. It also revealed details that were otherwise not visible with the naked eye, such as the eyelashes. Macroscopic imaging was complemented by the study of paint cross-sections using: light microscopy, SEM-EDX, FIB-STEM, synchrotron radiation mu-XRPD and FTIR-ATR. Vermeer intentionally used different qualities or grades of lead white in the flesh paints, showing different hydrocerussite/cerussite ratios and particle sizes. Lead isotope analysis showed that the geographic source of lead, from which the different types of lead white were manufactured, was the same: the region of Peak District of Derbyshire, UK. Finally, cross-section analysis identified the formation of new lead species in the paints: lead soaps and palmierite (K2Pb(SO4)(2)), associated with the red lake.
Keywords: A1 Journal article; Art; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1186/S40494-019-0344-0
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“Behavior of semi-volatile particles under a laser and electron beam: influence on the quality of analytical results”. Worobiec A, Potgieter-Vermaak S, Darchuk L, Vishnyakov V, Potgieter H, Van Grieken R, AIP conference proceedings 1267, 523 (2010). http://doi.org/10.1063/1.3482653
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation); Laboratory Experimental Medicine and Pediatrics (LEMP)
DOI: 10.1063/1.3482653
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“Benchmark study on algae harvesting with backwashable submerged flat panel membranes”. de Baerdemaeker T, Lemmens B, Dotremont C, Fret J, Roef L, Goiris K, Diels L, Bioresource technology 129, 582 (2013). http://doi.org/10.1016/J.BIORTECH.2012.10.153
Abstract: The feasibility of algae harvesting with submerged flat panel membranes was investigated as pre-concentration step prior to centrifugation. Polishing of the supernatant coming from the centrifuge was evaluated as well. The effect of membrane polymer (polyvinyl chloride [PVC], polyethersulfone polyvinyl-pyrollidone [PES-PVP], poly vinylidene fluoride [PVDF]), pore size (microfiltration [MF], ultrafiltration [UF]), algae cell concentrations and species were investigated at lab-scale. In addition, backwashing as fouling control was compared to standard relaxation. PVDF was the superior polymer, and UF showed better fouling resistance. Backwashing outperformed relaxation in fouling control. The backwashable membranes allowed up to 300% higher fluxes compared to commercial flat panel benchmark (PVC) membranes. Estimations on energy consumption for membrane filtration followed by centrifugation revealed relatively low values of 0.169 kW h/kg of dry weight of algae compared to 0.5 kW h/kg for algae harvesting via classical centrifuge alone. (C) 2012 Elsevier Ltd. All rights reserved.
Keywords: A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL)
DOI: 10.1016/J.BIORTECH.2012.10.153
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“Benzene concentrations on board chemical tankers”. Jacobs W, Dubois D, Floren E, Aerts D, Goris J, Buczyńska A, Van Grieken R, WMU journal of maritime affairs 10, 117 (2011). http://doi.org/10.1007/S13437-010-0002-6
Abstract: Maritime transport of benzene is regulated by the International Maritime Organisation (IMO). Two important guidelines for a ships crew in this matter are IMO circulars 1095 and 1220. The first one describes the minimum safety standards for ships carrying liquids in bulk containing benzene while circular 1220 deals with structural guidelines for new ships carrying liquids in bulk containing benzene, but also technical developments could help in improving safety and health protection on board chemical tankers carrying benzene in bulk. The aim of the present paper is to determine the benzene concentration in the working and living environment on board a modern chemical tanker carrying benzene in bulk, where all safety, technical and operational procedures described by IMO in the above-mentioned circulars are followed. During specific cargo operations, we measured the benzene concentrations on different locations on board by means of Radiello® passive diffusive samplers. Despite all measures taken, we found an important difference in benzene concentration between operations with a benzene cargo compared to operations without benzene on board, as well as inside and outside the accommodation. Moreover, even during discharge operations, where the emission is theoretically zero, we found an important increase in the benzene concentration. In addition, we found less favourable results for the engine room.
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1007/S13437-010-0002-6
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“Bio-based aromatic amines from lignin-derived monomers”. Blondiaux E, Bomon J, Smolen M, Kaval N, Lemière F, Sergeyev S, Diels L, Sels B, Maes BUW, ACS Sustainable Chemistry and Engineering 7, 6906 (2019). http://doi.org/10.1021/ACSSUSCHEMENG.8B06467
Abstract: A new approach to synthesize valuable 3,4-dialkoxyanilines and alkyl propionates from lignin-derived 4-propylguaiacol and -catechol with overall isolated yields up to 65% has been described. The strategy is based on the introduction of nitrogen via a Beckmann rearrangement. Amino introduction therefore coincides with a C-defunctionalization reaction; overall a replacement of the propyl chain by an amino group is obtained. The process only requires cheap bulk chemicals as reagents/reactants and does not involve column chromatography to purify the reaction products. Furthermore, all carbon atoms from the biorenewable lignin-derived monomers are transformed into valuable compounds. Greenness was assessed by performing a Green Metrics analysis on two dialkoxyanilines. A comparison was made with literature routes for these compounds starting from a petrochemical substrate.
Keywords: A1 Journal article; Engineering sciences. Technology; Organic synthesis (ORSY); Sustainable Energy, Air and Water Technology (DuEL)
DOI: 10.1021/ACSSUSCHEMENG.8B06467
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“Biogeochemical study of a coccolithophore bloom in the northern Bay of Biscay (NE Atlantic Ocean) in June 2004”. Harlay J, Borges AV, van der Zee C, Delille B, Godoi RHM, Schiettecatte L-S, Roevros N, Aerts K, Lapernat P-E, Rebreanu L, Groom S, Daro M-H, Van Grieken R, Chou L, Progress in oceanography 86, 317 (2010). http://doi.org/10.1016/J.POCEAN.2010.04.029
Abstract: The present paper synthesizes data obtained during a multidisciplinary cruise carried out in June 2004 at the continental margin of the northern Bay of Biscay. The data-set allows to describe the different stages of a coccolithophore bloom dominated by Emiliania huxleyi. The cruise was carried out after the main spring phytoplankton bloom that started in mid-April and peaked in mid-May. Consequently, low phosphate (PO4 < 0.2 μM) and silicate (DSi < 2.0 μM) concentrations, low partial pressure of carbon dioxide (pCO2) and high calcite saturation degree in surface waters combined with thermal stratification, probably favoured the blooming of coccolithophores. During the period of the year our cruise was carried out, internal tides induce enhanced vertical mixing at the continental shelf break leading to the injection of inorganic nutrients to surface waters that probably trigger the bloom. The bloom developed as the water-column stratified and as the water mass was advected over the continental shelf, following the general residual circulation in the area. The most developed phase of the bloom was sampled in a remote sensed high reflectance (HR) patch over the continental shelf that was characterized by low chlorophyll-a (Chl-a) concentration in surface waters (<1.0 μg L−1), high particulate inorganic carbon (PIC) concentration (not, vert, similar8 μmol L−1) and coccolithophore abundance up to 57 × 106 cells L−1. Transparent exopolymer particles (TEP) concentrations ranged between 15 and 75 μg C L−1 and carbon content of TEP represented up to 26% of the particulate organic carbon (POC; maximum concentration of 15.5 μmol L−1 in the upper 40 m). Integrated primary production (PP) ranged between 210 and 680 mg C m−2 d−1 and integrated calcification (CAL) ranged between 14 and 140 mg C m−2 d−1, within the range of PP and CAL values previously reported during coccolithophore blooms in open and shelf waters of the North Atlantic Ocean. Bacterial protein production (BPP) measurements in surface waters (0.30.7 μg C L−1 h−1) were much higher than those reported during early phases of coccolithophore blooms in natural conditions, but similar to those during peak and declining coocolithophorid blooms reported in mesocosms. Total alkalinity anomalies with respect to conservative mixing (ΔTA) down to −49 μmol kg−1 are consistent with the occurrence of biogenic precipitation of calcite, while pCO2 remained 15107 μatm lower than atmospheric equilibrium (372 μatm). The correlation between ΔTA and pCO2 suggested that pCO2 increased in part due to calcification, but this increase was insufficient to overcome the background under-saturation of CO2. This is related to the biogeochemical history of the water masses due to net carbon fixation by the successive phytoplankton blooms in the area prior to the cruise, hence, the investigated area remained a sink for atmospheric CO2 despite calcification.
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1016/J.POCEAN.2010.04.029
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“Bremsstrahlung background in electron-probe X-ray-microanalysis of thin films”. Markowicz AA, Storms HM, Van Grieken RE, Analytical chemistry 57, 2885 (1985). http://doi.org/10.1021/AC00291A032
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1021/AC00291A032
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“Bridging global, basin and local-scale water quality modeling towards enhancing water quality management worldwide”. Tang T, Strokal M, van Vliet MTH, Seuntjens P, Burek P, Kroeze C, Langan S, Wada Y, Current Opinion in Environmental Sustainability 36, 39 (2019). http://doi.org/10.1016/J.COSUST.2018.10.004
Abstract: Global water quality (WQ) modeling is an emerging field. In this article, we identify the missing linkages between global and basin/local-scale WQ models, and discuss the possibilities to fill these gaps. We argue that WQ models need stronger linkages across spatial scales. This would help to identify effective scale-specific WQ management options and contribute to future development of global WQ models. Two directions are proposed to improve the linkages: nested multiscale WQ modeling towards enhanced water management, and development of next-generation global WQ models based-on basin/local-scale mechanistic understanding. We highlight the need for better collaboration among WQ modelers and policy-makers in order to deliver responsive water policies and management strategies across scales.
Keywords: A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL)
DOI: 10.1016/J.COSUST.2018.10.004
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“Calculation of the spectral line profile broadening parameter in graphite furnace atomic absorption spectrometry”. Bencs L, Canadian Journal Of Analytical Sciences And Spectroscopy 53, 52 (2008)
Abstract: A polynomial approach is applied for a number of data from the Posener-tables to calculate the values of the intensity distribution function of atomic absorption lines – H(a, 0.726a) – at the tabulated damping-parameter values with an error not worse than 0.044 %. For the resultant H(a, 0.726a) data, the ninth and sixth order polynomials can be fitted according to the damping parameter range of 0-2, and 2-10, respectively, which results in a minimal error of approximation. The derived functions are simply applicable to the calculation of any H(a, 0.726a) value belonging to a damping-parameter of any arbitrarily selected spectral line, implying the influence of Doppler- and Lorentz-broadening. The overall error of the described method is lower than 0.4 %.
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
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“Capture-ferment-upgrade : a three-step approach for the valorization of sewage organics as commodities”. Alloul A, Ganigue R, Spiller M, Meerburg F, Cagnetta C, Rabaey K, Vlaeminck SE, Environmental science and technology 52, 6729 (2018). http://doi.org/10.1021/ACS.EST.7B05712
Abstract: This critical review outlines a roadmap for the conversion of chemical oxygen demand (COD) contained in sewage to commodities based on three-steps: capture COD as sludge, ferment it to volatile fatty acids (VFA), and upgrade VFA to products. The article analyzes the state-of-the-art of this three step approach and discusses the bottlenecks and challenges. The potential of this approach is illustrated for the European Union's 28 member states (EU-28) through Monte Carlo simulations. High-rate contact stabilization captures the highest amount of COD (66-86 g COD person equivalent(-1) day(-1) in 60% of the iterations). Combined with thermal hydrolysis, this would lead to a VFA-yield of 23-44 g COD person equivalent(-1) day(-1). Upgrading VFA generated by the EU-28 would allow, in 60% of the simulations, for a yearly production of 0.2-2.0 megatonnes of esters, 0.7-1.4 megatonnes of polyhydroxyalkanoates or 0.6-2.2 megatonnes of microbial protein substituting, respectively, 20-273%, 70-140% or 21-72% of their global counterparts (i.e., petrochemical-based esters, bioplastics or fishmeal). From these flows, we conclude that sewage has a strong potential as biorefinery feedstock, although research is needed to enhance capture, fermentation and upgrading efficiencies. These developments need to be supported by economic/environmental analyses and policies that incentivize a more sustainable management of our resources.
Keywords: A1 Journal article; Sustainable Energy, Air and Water Technology (DuEL)
DOI: 10.1021/ACS.EST.7B05712
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“Case specific prediction intervals for tri-PLS1 : the full local linearisation”. Serneels S, Faber K, Verdonck T, van Espen PJ, Chemometrics and intelligent laboratory systems 108, 93 (2011). http://doi.org/10.1016/J.CHEMOLAB.2011.05.002
Abstract: A new method to estimate case specific prediction uncertainty for univariate trilinear partial least squares (tri-PLS1) regression is introduced. This method is, from a theoretical point of view, the most exact finite sample approximation to true prediction uncertainty that has been reported up till now. Using the new method, different error sources can be propagated, which is an advantage that cannot be offered by data driven approaches such as the bootstrap. In a concise example, it is illustrated how the method can be applied. In the Appendix, efficient algorithms are presented to compute the estimates required.
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1016/J.CHEMOLAB.2011.05.002
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“A case study of high-temperature corrosion in rotary cement kilns”. Potgieter JH, Godoi RHM, Van Grieken R, Journal of the South African Institute of Mining and Metallurgy 104, 603 (2004)
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
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“A case study of ship track formation in a polluted marine boundary layer”. Noone KJ, Johnson DW, Taylor JP, Ferek RJ, Garrett T, Hobbs PV, Durkee PA, Nielsen K, Öström E, O'Dowd CD, Smith MH, Russell LM, Flagan RC, Seinfeld JH, de Bock L, Van Grieken RE, Hudson JG, Brooks I, Gasparovic RF, Pockalny RA, Journal of the atmospheric sciences 57, 2748 (2000). http://doi.org/10.1175/1520-0469(2000)057<2748:ACSOST>2.0.CO;2
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1175/1520-0469(2000)057<2748:ACSOST>2.0.CO;2
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“A case study of ships forming and not forming tracks in moderately polluted clouds”. Noone KJ, Öström E, Ferek RJ, Garrett T, Hobbs PV, Johnson DW, Taylor JP, Russell LM, Flagan RC, Seinfeld JH, O'Dowd CD, Smith MH, Durkee PA, Nielsen K, Hudson JG, Pockalny RA, de Bock L, Van Grieken RE, Gasparovic RF, Brooks I, Journal of the atmospheric sciences 57, 2729 (2000). http://doi.org/10.1175/1520-0469(2000)057<2729:ACSOSF>2.0.CO;2
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1175/1520-0469(2000)057<2729:ACSOSF>2.0.CO;2
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“The cathedral of Bari, Italy: evaluation of environmental effects on stone decay phenomena”. Torfs K, Van Grieken R, Zezza F, Garcia N, Macri F, Studies in conservation = Études de conservation 42, 193 (1997). http://doi.org/10.2307/1506750
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.2307/1506750
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“Centralised, decentralised or hybrid sanitation systems? Economic evaluation under urban development uncertainty and phased expansion”. Roefs I, Meulman B, Vreeburg JHG, Spiller M, Water research 109, 274 (2017). http://doi.org/10.1016/J.WATRES.2016.11.051
Abstract: Sanitation systems are built to be robust, that is, they are dimensioned to cope with population growth and other variability that occurs throughout their lifetime. It was recently shown that building sanitation systems in phases is more cost effective than one robust design. This phasing can take place by building small autonomous decentralised units that operate closer to the actual demand. Research has shown that variability and uncertainty in urban development does affect the cost effectiveness of this approach. Previous studies do not, however, consider the entire sanitation system from collection to treatment. The aim of this study is to assess the economic performance of three sanitation systems with different scales and systems characteristics under a variety of urban development pathways. Three systems are studied: (I) a centralised conventional activated sludge treatment, (II) a community on site source separation grey water and black water treatment and (III) a hybrid with grey water treatment at neighbourhood scale and black water treatment off site. A modelling approach is taken that combines a simulation of greenfield urban growth, a model of the wastewater collection and treatment infrastructure design properties and a model that translates design parameters into discounted asset lifetime costs. Monte Carlo simulations are used to evaluate the economic performance under uncertain development trends. Results show that the conventional system outperforms both of the other systems when total discounted lifetime costs are assessed, because it benefits from economies of scale. However, when population growth is lower than expected, the source-separated system is more cost effective, because of reduced idle capacity. The hybrid system is not competitive under any circumstance due to the costly double piping and treatment. (C) 2016 Elsevier Ltd. All rights reserved.
Keywords: A1 Journal article; Sustainable Energy, Air and Water Technology (DuEL)
DOI: 10.1016/J.WATRES.2016.11.051
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“CFD- and radiation field modeling of a gas phase photocatalytic multi-tube reactor”. Roegiers J, van Walsem J, Denys S, Chemical engineering journal 338, 287 (2018). http://doi.org/10.1016/J.CEJ.2018.01.047
Abstract: This paper focusses on the development of a Multiphysics model as a tool for assessing the performance of a multi-tube photoreactor. The model predicts the transient behavior of acetaldehyde concentration, as a model compound for the organic fraction of the indoor air pollutants, under varying sets of conditions. A 3D-model couples radiation field modeling with reaction kinetics and fluid dynamics in order to simulate the transport of the pollutant as it progresses through the reactor. A model-based approach is proposed to determine the layer thickness and refractive index of different P25-powder modified solgel coatings, using an optimization procedure to estimate these parameters based on UV-irradiance measurements. The radiation field model was able to accurately predict the irradiance on the catalytic surface within the reactor. Consequently, the radiation field model was used to define an irradiance dependent reaction rate constant in a coupled Multiphysics model. An optimization routine was deployed to estimate the adsorption, desorption- and photocatalytic reaction rate constants on the TiO2-surface, using experimentally determined, transient outlet concentrations of acetaldehyde. Additionally, a validation test was performed in an air-tight climate chamber at much higher flow rates, higher irradiance and realistic indoor pollutant concentrations to emphasize the reliability and accuracy of the parameters for adsorption, desorption and photocatalytic reaction. The developed model makes it possible to optimize the reactor design and scale-up for commercial applications.
Keywords: A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL)
DOI: 10.1016/J.CEJ.2018.01.047
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“CFD-modelling of activated carbon fibers for indoor air purification”. Roegiers J, Denys S, Chemical engineering journal 365, 80 (2019). http://doi.org/10.1016/J.CEJ.2019.02.007
Abstract: Activated carbon fibers for indoor air purification were investigated by means of pressure drop and adsorption capacity. The Darcy-Forchheimer law combined with Computational Fluid Dynamics (CFD) modelling was deployed to simulate the pressure drop over an activated carbon fiber (ACF) filter with varying filter thickness. The CFD model was later combined with adsorption modelling to simulate breakthrough profiles of acetaldehyde adsorption on the ACF-filter. The adsorption model incorporates mass transfer resistance and adsorption equilibrium. It assumes local equilibrium between gas phase and solid phase. The latter was investigated for three different adsorption isotherms: linear, Langmuir and Freundlich adsorption. Successful agreement between model simulations and experimental data was obtained, using the Freundlich adsorption model. The numerical model could provide valuable insights and allows to continuously improve the design of filtration devices.
Keywords: A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL)
DOI: 10.1016/J.CEJ.2019.02.007
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“Characterisation of aerosol particles in the São Paulo Metropolitan Area”. de Miranda RM, de Fátima Andrade M, Worobiec A, Van Grieken R, Atmospheric environment : an international journal 36, 345 (2002). http://doi.org/10.1016/S1352-2310(01)00363-6
Keywords: A1 Journal article; Laboratory Experimental Medicine and Pediatrics (LEMP); AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1016/S1352-2310(01)00363-6
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“Characterisation of Amazon Basin aerosols at the individual particle level by X-ray microanalytical techniques”. Worobiec A, Szalóki I, Osán J, Maenhaut W, Stefaniak EA, Van Grieken R, Atmospheric environment : an international journal 41, 9217 (2007). http://doi.org/10.1016/J.ATMOSENV.2007.07.056
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation); Laboratory Experimental Medicine and Pediatrics (LEMP)
DOI: 10.1016/J.ATMOSENV.2007.07.056
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“Characterisation of concentrates of heavy mineral sands by micro-Raman spectrometry and CC-SEM/EDX with HCA”. Worobiec A, Stefaniak EA, Potgieter-Vermaak S, Sawlowicz Z, Spolnik Z, Van Grieken R, Applied geochemistry 22, 2078 (2007). http://doi.org/10.1016/J.APGEOCHEM.2007.05.003
Keywords: A1 Journal article; Laboratory Experimental Medicine and Pediatrics (LEMP); AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1016/J.APGEOCHEM.2007.05.003
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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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“Characterisation of individual aerosol particles for atmospheric and cultural heritage studies”. Van Grieken R, Gysels K, Hoornaert S, Joos P, Osán J, Szalóki I, Worobiec A, Water, air and soil pollution 123, 215 (2000). http://doi.org/10.1023/A:1005215304729
Keywords: A1 Journal article; Laboratory Experimental Medicine and Pediatrics (LEMP); AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1023/A:1005215304729
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“Characterisation of individual atmospheric particles within the Royal Museum of the Wawel Castle in Cracow, Poland”. Worobiec A, Stefaniak EA, Kontozova V, Samek L, Karaszkiewicz P, van Meel K, Van Grieken R, e-Preservation Science 3, 63 (2006)
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation); Laboratory Experimental Medicine and Pediatrics (LEMP)
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“Characterisation of particulate matter in the Royal Museum of Fine Arts, Antwerp, Belgium”. Gysels K, Deutsch F, Van Grieken R, Atmospheric environment : an international journal 36, 4103 (2002). http://doi.org/10.1016/S1352-2310(02)00229-7
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1016/S1352-2310(02)00229-7
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“Characterisation of soot emitted by domestic heating, aircraft and cars using diesel or biodiesel”. Smekens A, Godoi RHM, Berghmans P, Van Grieken R, Journal of atmospheric chemistry 52, 45 (2005). http://doi.org/10.1007/S10874-005-6903-7
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1007/S10874-005-6903-7
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“Characterisation of sugar cane combustion particles in the Araraquara region, Southeast Brazil”. Godoi RHM, Godoi AFL, Worobiec A, Andrade SJ, de Hoog J, Santiago-Silva MR, Van Grieken R, Microchimica acta 145, 53 (2004). http://doi.org/10.1007/S00604-003-0126-X
Keywords: A1 Journal article; Laboratory Experimental Medicine and Pediatrics (LEMP); AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1007/S00604-003-0126-X
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“A characterisation of the surface properties of an ultra fine fly ash (UFFA) used in the polymer industry”. Potgieter-Vermaak SS, Potgieter JH, Kruger RA, Spolnik Z, Van Grieken R, Fuel 84, 2295 (2005). http://doi.org/10.1016/J.FUEL.2005.05.013
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1016/J.FUEL.2005.05.013
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“Characterisation of wood combustion particles using electron probe microanalysis”. Osán J, Alföldy B, Török S, Van Grieken R, Atmospheric environment : an international journal 36, 2207 (2002). http://doi.org/10.1016/S1352-2310(02)00153-X
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1016/S1352-2310(02)00153-X
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“Characteristics of atomic absorption calibration curves with the transversely heated graphite furnace”. Bencs L, Szakács O, Szoboszlai N, Ajtony Z, Bozsai G, Journal of analytical atomic spectrometry 18, 105 (2003). http://doi.org/10.1039/B208198A
Abstract: Calibration curves with two quasi-linear sections ("double sloping'') were observed for the medium volatile elements, Cr and Cu, with the use of a SIMAA 6000 graphite furnace atomic absorption spectrometer under interrupted internal gas flow conditions. If a standard transversally heated graphite atomizer (THGA) tube was shortened by 0.5 mm at both of its ends, (i.e. the gaps were enlarged between graphite furnace housing and tube ends), a stronger declination of the calibration curves resulted. Elements with fairly high diffusion coefficients (>5.8 cm(2) s(-1)) and with short appearance time of their transients (<0.6 s), such as Cr and Cu, have shown the most characteristic sensitivity drop towards higher concentrations. This anomalous feature could be eliminated in three different ways; (1) by applying end-capped THGA tubes, (2) using mini-flow (50 cm(3) min(-1)) conditions during the atomization stage, and (3) by adding Pd-Mg chemical modifier. For the low volatile Mo and V, the calibration curves had no irregular shape. For Ag, Co, Cr, Cu, Mn and Ni, the mini-flow settings improved the linearity of the calibration curves and extended the upper limit of the linear calibration range by a factor of 1.5-2.0. The irregular characteristic of the analytical curves was interpreted as an increased vapour loss at higher analyte concentrations through the opened ends of the standard THGA tubes. This vapour loss was associated with the significantly diverse expulsion velocities of atoms, caused by the difference in temperature and concentration gradients, when evaporating amounts of analytes with more than one order of magnitude difference.
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1039/B208198A
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