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“Visualizing the 17th century underpainting in Portrait of an Old Man by Rembrandt van Rijn using synchrotron-based scanning macro-XRF”. Alfeld M, Siddons DP, Janssens K, Dik J, Woll A, Kirkham R, van de Wetering E, Applied physics A : materials science &, processing 111, 157 (2013). http://doi.org/10.1007/S00339-012-7490-5
Abstract: In 17th century Old Master Paintings, the underpainting generally refers to the first sketch of a composition. The underpainting is applied to a prepared ground using a monochrome, brown oil paint to roughly indicate light, shade and contours. So far, methods to visualize the underpainting-other than in localized cross-sections-have been very limited. Neither infrared reflectography nor neutron induced autoradiography have proven to be practical, adequate visualization tools. Thus, although of fundamental interest in the understanding of a painting's genesis, the underpainting has virtually escaped all imaging efforts. In this contribution we will show that 17th century underpainting may consist of a highly heterogeneous mixture of pigments, including copper pigments. We suggest that this brown pigment mixture is actually the recycled left-over of a palette scraping. With copper as the heaviest exclusive elemental component, we will hence show in a case study on a Portrait of an Old Man attributed to Rembrandt van Rijn how scanning macro-XRF can be used to efficiently visualize the underpainting below the surface painting and how this information can contribute to the discussion of the painting's authenticity.
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Impact Factor: 1.455
Times cited: 26
DOI: 10.1007/S00339-012-7490-5
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“Efficiency of applying ammonium oxalate for protection of monumental limestone by poultice, immersion and brushing methods”. Mudronja D, Vanmeert F, Hellemans K, Fazinic S, Janssens K, Tibljas D, Rogosic M, Jakovljevic S, Applied physics A : materials science &, processing 111, 109 (2013). http://doi.org/10.1007/S00339-012-7365-9
Abstract: Samples of cretaceous limestone have been treated with three application methods (poultice, immersion and brushing) using different concentrations of ammonium oxalate solution (AmOx) and varying treatment time in order to test the efficiency of surface and in-depth formation of a protective layer of calcium oxalate (CaOx). Synchrotron-based microanalytical techniques (SR-mu XRD with 12.5 mu mx7.5 mu m (HxV) probe size, SR-mu FTIR with 10 mu mx10 mu m and 8 mu mx20 mu m probe sizes) and laboratory mu FTIR, XRD and SEM have been employed for analysis of the treated samples. Synchrotron-based techniques showed variations in the CaOx distribution along the surface on a micrometer scale. All treatments resulted in the development of a CaOx layer with a maximum thickness of approximately 40 mu m. Application by the brushing method with 10 1-min applications with 5-min breaks during one hour showed a development of the calcium oxalate layer equivalent to the poultice treatment taking 10 h. This treatment could be preferred for large marble or limestone surfaces where poultice usage is economically not feasible.
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Impact Factor: 1.455
Times cited: 13
DOI: 10.1007/S00339-012-7365-9
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“Spatially resolved (semi)quantitative determination of iron (Fe) in plants by means of synchrotron micro X-ray fluorescence”. Terzano R, Alfeld M, Janssens K, Vekemans B, Schoonjans T, Vincze L, Tomasi N, Pinton R, Cesco S, Analytical and bioanalytical chemistry 405, 3341 (2013). http://doi.org/10.1007/S00216-013-6768-6
Abstract: Iron (Fe) is an essential element for plant growth and development; hence determining Fe distribution and concentration inside plant organs at the microscopic level is of great relevance to better understand its metabolism and bioavailability through the food chain. Among the available microanalytical techniques, synchrotron mu-XRF methods can provide a powerful and versatile array of analytical tools to study Fe distribution within plant samples. In the last years, the implementation of new algorithms and detection technologies has opened the way to more accurate (semi)quantitative analyses of complex matrices like plant materials. In this paper, for the first time the distribution of Fe within tomato roots has been imaged and quantified by means of confocal mu-XRF and exploiting a recently developed fundamental parameter-based algorithm. With this approach, Fe concentrations ranging from few hundreds of ppb to several hundreds of ppm can be determined at the microscopic level without cutting sections. Furthermore, Fe (semi)quantitative distribution maps were obtained for the first time by using two opposing detectors to collect simultaneously the XRF radiation emerging from both sides of an intact cucumber leaf.
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Impact Factor: 3.431
Times cited: 27
DOI: 10.1007/S00216-013-6768-6
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“Compositional correlation between pigments found in excavations and on human bones investigated with micro-raman spectrometry and scanning electron microscopy”. Vázquez C, Darchuk L, Stefaniak EA, Van Grieken R, Palacios OR page 13 (2011).
Keywords: H2 Book chapter; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
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“Elemental and ionic components of atmospheric aerosols and associated gaseous pollutants in and near Dar es Salaam, Tanzania”. Mmari AG, Potgieter-Vermaak SS, Bencs L, McCrindle RI, Van Grieken R, Atmospheric environment : an international journal 77, 51 (2013). http://doi.org/10.1016/J.ATMOSENV.2013.04.061
Abstract: Elemental and water-soluble ionic compounds (WSICs) of atmospheric aerosols (total suspended particulate TSP) and some gaseous pollutants (SO2, NO2 and O3) from a coastal, semi-urban and rural site in and near Dar es Salaam, Tanzania were investigated during dry and wet seasons of January 2005November 2007. Na+, Ca2+, SO42−, NO3− and Cl− made up the dominant fraction of WSICs during the dry season with average concentrations ranging from non-detectable (n.d.)5.4, 0.262.6, 0.7414.7, 0.41.5 and 1.13.4 μg m−3, respectively, while in the wet season, from n.d. up to 1.7, 1.2, 4.4, 2.1 and 3.0 μg m−3, respectively. The total air concentrations of the detected elements (Al, Si, S, Cl, K, Ca, Fe and Zn) showed seasonal and site-specific variation in the range of 7.526.6 with an average of 14.5 μg m−3. Most of the air concentrations of pollutants were observed to decrease with increasing distance from the coastal site, which is under urban and industrial pollutant emissions. Sulphur and nitrogen oxidation ratios during the dry season ranged from 0.08 to 0.91 and 0.013 to 0.049, respectively, while they were between 0.090.65 and 0.0020.095, respectively, in the wet season. These values indicate the photochemical oxidation of SO2 and a high extent of NO3−formation in the atmosphere. Neutralization ratios revealed the presence of acidic SO42− and NO3− aerosols. Principal component analysis identified sea spray, local combustion, vehicular traffic, biomass burning and re-suspended road dust as dominant sources of aerosols at the studied coastal and semi-urban sites. However, at the rural site, besides sea spray, crustal sources, soil dust re-suspension and long-range transport are the possible origins of suspended particulates.
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1016/J.ATMOSENV.2013.04.061
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Bencs L, Horemans B, Van Grieken R, et al. (2012) Atmospheric deposition fluxes to the Belgian marine waters originating from ship emissions : SHIPFLUX : final report
Keywords: Minutes and reports; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
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“Microchemical investigation of bone derived from mice treated with strontium in different chemical forms using scanning electron microscopy and micro-Raman spectroscopy”. Jabłoński MB, Stefaniak EA, Darchuk L, Turzańska K, Gorzelak M, Kuduk R, Dorriné, W, Van Grieken R, Microchemical journal 108, 168 (2013). http://doi.org/10.1016/J.MICROC.2012.10.015
Abstract: We used SEM/EDX and micro-Raman spectroscopy to investigate the chemical changes (both on the level of elementary and molecular composition) of mice bones when strontium is incorporated in their microstructure after being administered in the form of two salts: chloride and ranelate. Strontium accumulated mainly in vicinity of bone edges, both cortical and close to bone marrow. The distribution of other elements comprising bone samples (Ca, P, Mg, K etc.) was also determined by energy-dispersive X-ray analysis (EDX). The area adjacent to a cortical bone edge with accumulated strontium has presented modified Raman spectral profiles. Besides most of the Raman bands typical for both mineral (hydroxyapatite with carbonate substitution type B) and organic phases of a bone, we observed a Raman band at 811 cm− 1. It was detected regularly in the sample with high strontium concentration.
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1016/J.MICROC.2012.10.015
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“Einfluss verschiedener Silbersalze auf die Farbintensität von Silbergelb : analytische Untersuchungen”. De Vis K, Jembrih-Simbürger D, Schalm O, Schreiner M, Caen J, Zeitschrift für Kunsttechnologie und Konservierung 16, 147 (2002)
Keywords: A2 Journal article; Art; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
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“Revealing hidden paint layers in oil paintings by means of scanning macro-XRF : a mock-up study based on Rembrandt's “An old man in military costume””. Alfeld M, de Nolf W, Cagno S, Janssens K, et al, Journal of analytical atomic spectrometry 28, 40 (2013). http://doi.org/10.1039/C2JA30119A
Abstract: Over the past several decades the oeuvre of Rembrandt has been the subject of extensive art historical and scientific investigations. One of the most striking features to emerge is his frequent re-use of canvases and panels. The painting An Old Man in Military Costume (78.PB.246), in the collection of the J. Paul Getty Museum, is an example of such a re-used panel. Conventional imaging techniques revealed the presence of a second portrait under the surface portrait, but the details of this hidden portrait have not yet been revealed. Vermilion (HgS) has been identified to have been used nearly exclusively in the flesh tones of the lower painting, suggesting that element-specific XRF imaging might successfully image the hidden portrait. To test this hypothesis, a full-scale mock-up of the painting was created, including a “free impression” of the hidden portrait, reproducing as closely as possible the pigments and paint stratigraphy of the original painting. XRF imaging of the mock-up painting was conducted using three different XRF imaging systems: a mobile X-ray tube based system and two synchrotron-based setups (one equipped with multiple SDDs and one equipped with a Maia detector). The sensitivity, limits of detection and imaging capabilities of each system under the chosen experimental conditions are evaluated and compared. The results indicate that an investigation of the original painting by this method would have an excellent chance of success.
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Impact Factor: 3.379
DOI: 10.1039/C2JA30119A
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“Seasonal trends of atmospheric nitrogen dioxide and sulfur dioxide over North Santa Clara, Cuba”. Alejo D, Morales MC, de la Torre JB, Grau R, Bencs L, Van Grieken R, van Espen P, Sosa D, Nuñez V, Environmental monitoring and assessment 185, 6023 (2013). http://doi.org/10.1007/S10661-012-3003-4
Abstract: Atmospheric nitrogen dioxide (NO2) and sulfur dioxide (SO2) levels were monitored simultaneously by means of Radiello passive samplers at six sites of Santa Clara city, Cuba, in the cold and the warm seasons in 2010. The dissolved ionic forms of NO2 and SO2 as nitrate and sulfite plus sulfate, respectively, were determined by means of ion chromatography. Analysis of NO2 as nitrite was also performed by UVVis spectrophotometry. For NO2, significant t tests show good agreement between the results of IC and UVVis methods. The NO2 and SO2 concentrations peaked in the cold season, while their minimum levels were experienced in the warm season. The pollutant levels do not exceed the maximum allowable limit of the Cuban Standard 39:1999, i.e., 40 μg/m3 and 50 μg/m3 for NO2 and SO2, respectively. The lowest pollutant concentrations obtained in the warm season can be attributed to an increase in their removal via precipitation (scavenging) while to the decreased traffic density and industrial emission during the summer holidays (e.g., July and August).
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1007/S10661-012-3003-4
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“New insight into UO2F2 particulate structure by micro-Raman spectroscopy”. Stefaniak EA, Darchuk L, Sapundjiev D, Kips R, Aregbe Y, Van Grieken R, Journal of molecular structure 1040, 206 (2013). http://doi.org/10.1016/J.MOLSTRUC.2013.02.012
Abstract: Uranyl fluoride particles produced via hydrolysis of uranium hexafluoride have been deposited on different substrates: polished graphite disks, silver foil, stainless steel and gold-coated silicon wafer, and measured with micro-Raman spectroscopy (MRS). All three metallic substrates enhanced the Raman signal delivered by UO2F2 in comparison to graphite. The fundamental stretching of the UO band appeared at 867 cm−1 in case of the graphite substrate, while in case of the others it was shifted to lower frequencies (down to 839 cm−1). All applied metallic substrates showed the expected effect of Raman signal enhancement; however the gold layer appeared to be most effective. Application of new substrates provides more information on the molecular structure of uranyl fluoride precipitation, which is interesting for nuclear safeguards and nuclear environmental analysis.
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1016/J.MOLSTRUC.2013.02.012
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“Indoor air quality of a museum in a subtropical climate : the Oscar Niemeyer museum in Curitiba, Brazil”. Godoi RHM, Carneiro BHB, Paralovo SL, Campos VP, Tavares TM, Evangelista H, Van Grieken R, Godoi AFL, The science of the total environment 452, 314 (2013). http://doi.org/10.1016/J.SCITOTENV.2013.02.070
Abstract: The assessment of damage to indoor cultural heritage, in particular by pollutants, is nowadays a major and growing concern for curators and conservators. Nevertheless, although many museums have been widely investigated in Europe, the effects of particulate matter and gaseous pollutants in museums under tropical and subtropical climates and with different economic realities are still unclear. An important portion of the world's cultural heritage is currently in tropical countries where both human and financial resources for preserving museum collections are limited. Hence, our aim is to assess the damage that can be caused to the artwork by pollution in hot and humid environments, where air quality and microclimatic condition differences can cause deterioration. As a case study, particulate matter as well as gases were collected at the Oscar Niemeyer Museum (MON) in Curitiba, Brazil, where large modern and contemporary works of art are displayed. NO2, SO2, O3, Acetic Acid, Formic Acids and BTEX, in the ambient air, were sampled by means of passive diffusive sampling and their concentrations were determined by IC or GCMS. The particulate matter was collected in bulk form and analyzed with the use of energy dispersive X-ray fluorescence and aethalometer. The chemical compositions of individual particles were quantitatively elucidated, including low-Z components like C, N and O, as well as higher-Z elements, using automated electron probe microanalysis. The gaseous and particulate matter levels were then compared with the concentrations obtained for the same pollutants in other museums, located in places with different climates, and with some reference values provided by international cultural heritage conservation centers. Results are interpreted separately and as a whole with the specific aim of identifying compounds that could contribute to the chemical reactions taking place on the surfaces of artifacts and which could potentially cause irreversible damage to the artworks.
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1016/J.SCITOTENV.2013.02.070
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“Gross alpha and beta activities of airborne particulate samples from Wawel Royal Castle Museum in Cracow, Poland”. Akbulut S, Krupinska B, Worobiec A, Čevik U, Taskin H, Van Grieken R, Samek L, Wiłkojć, E, Journal of radioanalytical and nuclear chemistry 295, 1567 (2013). http://doi.org/10.1007/S10967-012-1983-8
Abstract: Soils are complex mixtures of organic, inorganic materials, and metal compounds from anthropogenic sources. In order to identify the pollution sources, their magnitude and development, several X-ray analytical methods were applied in this study. The concentrations of 16 elements were determined in all the soil samples using energy dispersive X-ray fluorescence spectrometry. Soils of unknown origin were observed by scanning electron microscopy equipped with a Si(Li) X-ray detector using Monte Carlo simulation approach. The mineralogical analyses were carried out using X-ray diffraction spectrometry. Due to the correlations between heavy metals and oxide compounds, the samples were analyzed also by electron probe microanalyzer (EPMA) in order to have information about their oxide contents. On the other hand, soil pH and salinity levels were identified owing to their influence between heavy metal and soil-surface chemistry. Moreover, the geoaccumulation index (I geo) enables the assessment of contamination by comparing current and pre-industrial concentrations.
Keywords: A1 Journal article; Engineering sciences. Technology; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation); Laboratory Experimental Medicine and Pediatrics (LEMP)
DOI: 10.1007/S10967-012-1983-8
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“Identification of heavy metal origins related to chemical and morphological soil properties using several non-destructive X-ray analytical methods”. Akbulut S, Van Grieken R, Kilic MA, Čevik U, Rotondo GG, Environmental monitoring and assessment 185, 2377 (2013). http://doi.org/10.1007/S10661-012-2718-6
Abstract: Soils are complex mixtures of organic, inorganic materials, and metal compounds from anthropogenic sources. In order to identify the pollution sources, their magnitude and development, several X-ray analytical methods were applied in this study. The concentrations of 16 elements were determined in all the soil samples using energy dispersive X-ray fluorescence spectrometry. Soils of unknown origin were observed by scanning electron microscopy equipped with a Si(Li) X-ray detector using Monte Carlo simulation approach. The mineralogical analyses were carried out using X-ray diffraction spectrometry. Due to the correlations between heavy metals and oxide compounds, the samples were analyzed also by electron probe microanalyzer (EPMA) in order to have information about their oxide contents. On the other hand, soil pH and salinity levels were identified owing to their influence between heavy metal and soil-surface chemistry. Moreover, the geoaccumulation index (I geo) enables the assessment of contamination by comparing current and pre-industrial concentrations.
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1007/S10661-012-2718-6
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“Polarized-beam high-energy EDXRF in geological samples”. Čevik U, Akbulut S, Makarovska Y, Van Grieken R, Spectroscopy letters 46, 36 (2013). http://doi.org/10.1080/00387010.2012.661015
Abstract: Certified reference materials (NIST 1645, BCR 143, IAEA 7, BCR 141, NIESCRM02, and IAEA 375) were used for determining the performance of a secondary target energy-dispersive X-ray fluorescence (EDXRF) spectrometer, Epsilon 5 (PANalytical, Almelo, the Netherlands). For the evaluation of the EDXRF spectra with polarized-beam high-energy excitation, the WinAxil software package has been applied. The results showed that Epsilon 5, EDXRF spectrometry is favorable for the determination of elemental concentrations in geological samples, but the sample preparation has the largest influence on the precision. However, they presented good agreement with certified values for most of the elements.
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1080/00387010.2012.661015
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Marguí, E, Van Grieken R (2013) X-ray fluorescence spectrometry and related techniques : an introduction. 148 p
Keywords: MA3 Book as author; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
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“Combined use of synchrotron radiation based micro-X-ray fluorescence, micro-X-ray diffraction, micro-X-ray absorption near-edge, and micro-fourier transform infrared spectroscopies for revealing an alternative degradation pathway of the pigment cadmium yellow in a painting by Van Gogh”. van der Snickt G, Janssens K, Dik J, de Nolf W, Vanmeert F, Jaroszewicz J, Cotte M, Falkenberg G, Van der Loeff L, Analytical chemistry 84, 10221 (2012). http://doi.org/10.1021/AC3015627
Abstract: Over the past years a number of studies have described the instability of the pigment cadmium yellow (CdS). In a previous paper we have shown how cadmium sulfide on paintings by James Ensor oxidizes to CdSO4 center dot H2O. The degradation process gives rise to the fading of the bright yellow color and the formation of disfiguring white crystals that are present on the paint surface in approximately 50 mu m sized globular agglomerations. Here, we study cadmium yellow in the painting “Flowers in a blue vase” by Vincent van Gogh. This painting differs from the Ensor case in the fact that (a) a varnish was superimposed onto the degraded paint surface and (b) the CdS paint area is entirely covered with an opaque crust. The latter obscures the yellow color completely and thus presents a seemingly more advanced state of degradation. Analysis of a cross-sectioned and a crushed sample by combining scanning microscopic X-ray diffraction (mu-XRD), microscopic X-ray absorption near-edge spectroscopy (mu-XANES), microscopic X-ray fluorescence (mu-XRF) based chemical state mapping and scanning microscopic Fourier transform infrared (mu-FT-IR) spectrometry allowed unravelling the complex alteration pathway. Although no crystalline CdSO4 compounds were identified on the Van Gogh paint samples, we conclude that the observed degradation was initially caused by oxidation of the original CdS pigment, similar as for the previous Ensor case. However, due to the presence of an overlying varnish containing lead-based driers and oxalate ions, secondary reactions took place. In particular, it appears that upon the photoinduced oxidation of its sulfidic counterion, the Cd2+ ions reprecipitated at the paint/varnish interface after having formed a complex with oxalate ions that themselves are considered to be degradation products of the resin and/or oil in the varnish. The SO42- anions, for their part, found a suitable reaction partner in Pb2+ ions stemming from a dissolved lead-based siccative that was added to the varnish to promote its drying. The resulting opaque anglesite compound in the varnish, in combination with the underlying CdC2O4 layer at the paint/varnish interface, account for the orange-gray crust that is disfiguring the painting on a macroscopic level. In this way, the results presented in this paper demonstrate how, through a judicious combined use of several microanalytical methods with speciation capabilities, many new insights can be obtained from two minute, but highly complex and heterogeneous paint samples.
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Impact Factor: 6.32
Times cited: 59
DOI: 10.1021/AC3015627
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“Restoration of X-ray fluorescence images of hidden paintings”. Anitha A, Brasoveanu A, Duarte M, Hughes S, Daubechies I, Dik J, Janssens K, Alfeld M, Signal processing 93, 592 (2013). http://doi.org/10.1016/J.SIGPRO.2012.09.027
Abstract: This paper describes our methods for repairing and restoring images of hidden paintings (paintings that have been painted over and are now covered by a new surface painting) that have been obtained via noninvasive X-ray fluorescence imaging of their canvases. This recently developed imaging technique measures the concentrations of various chemical elements at each two-dimensional spatial location across the canvas. These concentrations in turn result from pigments present both in the surface painting and in the hidden painting beneath. These X-ray fluorescence images provide the best available data from which to noninvasively study a hidden painting. However, they are typically marred by artifacts of the imaging process, features of the surface painting, and areas of information loss. Repairing and restoring these images thus consists of three stages: (1) repairing acquisition artifacts in the dataset, (2) removal of features in the images that result from the surface painting rather than the hidden painting, and (3) identification and repair of areas of information loss. We describe methods we have developed to address each of these stages: a total-variation minimization approach to artifact correction, a novel method for underdetermined blind source separation with multimodal side information to address surface feature removal, and two application-specific new methods for automatically identifying particularly thick or X-ray absorbent surface features in the painting. Finally, we demonstrate the results of our methods on a hidden painting by the artist Vincent van Gogh. (C) 2012 Elsevier B.V. All rights reserved.
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Impact Factor: 3.11
Times cited: 13
DOI: 10.1016/J.SIGPRO.2012.09.027
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“Mineral dust variability in central West Antarctica associated with ozone depletion”. Cataldo M, Evangelista H, Simões JC, Godoi RHM, Simmonds I, Hollanda MH, Wainer I, Aquino F, Van Grieken R, Atmospheric chemistry and physics 13, 2165 (2013). http://doi.org/10.5194/ACP-13-2165-2013
Abstract: We present here data of mineral dust variability retrieved from an ice core of the central West Antarctic, spanning the last five decades. Main evidence provided by the geochemical analysis is that northerly air mass incursions to the coring site, tracked by insoluble dust microparticles, have declined over the past 50 yr. This result contrasts with dust records from ice cores reported to the coastal West Antarctic that show increases since mid-20th century. We attribute this difference to regional climatic changes due to the ozone depletion and its implications to westerly winds. We found that the diameters of insoluble microparticles in the central West Antarctica ice core are significantly correlated with cyclone depth (energy) and wind intensity around Antarctica.
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.5194/ACP-13-2165-2013
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“Influence of the deposition method, temperature and deposition time on the corrosion inhibition of lead dodecanoate coatings deposited on lead surfaces”. De Keersmaecker M, De Wael K, Adriaens A, Journal of solid state electrochemistry 17, 1259 (2013). http://doi.org/10.1007/S10008-012-1964-4
Abstract: Electrochemical impedance measurements have been used to investigate the influence of the deposition method, including time and temperature, upon the corrosion inhibition characteristics of lead dodecanoate coatings on lead electrodes. The results were analysed using multivariate statistics and show that, in general, these easily prepared coatings are very protective against corrosion. The temperature proves to be an important parameter for the quality and the corrosion inhibition efficiency of the coating. A comparison between two different electrochemically assisted deposition methods, immersion using a reduction pretreatment and cyclic voltammetry, does not show significant differences. Using the immersion technique at room temperature, the deposition time was tested as the third influencing parameter for the corrosion inhibition efficiency of the deposited lead dodecanoate coatings. A longer deposition time of the lead into the sodium dodecanoate solution provides a layer with a somewhat higher corrosion resistance.
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Impact Factor: 2.316
Times cited: 4
DOI: 10.1007/S10008-012-1964-4
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“Spatial monitoring of organohalogen compounds in surface water and sediments of a rural-urban river basin in Tanzania”. Hellar-Kihampa H, De Wael K, Lugwisha E, Govindan M, Covaci A, Van Grieken R, The science of the total environment 447, 186 (2013). http://doi.org/10.1016/J.SCITOTENV.2012.12.083
Abstract: The presence of persistent organic pollutants in Tanzanian environment is not well monitored despite the existing pollution potential from a number of sources. In this study, we investigated for the first time, the concentration profiles of different organohalogen compounds such as organochlorine pesticide residues (OCPs), polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs) in environmental samples (water and sediments) from the Pangani river basin (PRB). The PRB is one of the largest drainage basins in Tanzania, with its watershed exposed to multiple input sources of trace organic contaminants. Surface water and sediments were sampled from 12 representative stations of diverse characteristics and land-use practices, in three distinct seasons, and extracted by liquidliquid and Soxhlet extraction methods, respectively. Water samples were analyzed by GC-ECD for OCPs only, while sediment samples were analyzed for OCPs, PCBs and PBDEs by GC/MS. Seven compounds, dominated by HCH isomers (5104460 pg/L) and DDT analogs (1601460 pg/L),were detected in the water samples. These concentrations are far below the WHO guidelines for drinking water quality. A total of 42 compounds (8 OCPs, 28 PCB congeners and 6 PBDE congeners) were detected in the sediment samples. Their respective total concentration ranges were 24510,230; 35711,000 and 382175 pg/g dry weight. The spatial distribution patterns and Hierarchical Cluster Analysis reflected the impact of historical agricultural usage in sugarcane plantations (OCPs), and urbanization (PCBs and PBDEs). Risk assessment using sediment quality guidelines indicated no ecotoxicological risks. The results we have found provide preliminary data on levels of the organic contaminants in Pangani river basin as a new insight on the environmental quality of the area.
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation); Toxicological Centre
Impact Factor: 4.9
Times cited: 42
DOI: 10.1016/J.SCITOTENV.2012.12.083
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“Editorial : award for best X-Ray Spectrometry referee during 2011-2012”. Van Grieken R, X-ray spectrometry 42, 3 (2013). http://doi.org/10.1002/XRS.2428
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1002/XRS.2428
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“New members of the editorial board of X-ray Spectrometry”. Van Grieken R, X-ray spectrometry 42, 1 (2013). http://doi.org/10.1002/XRS.2431
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1002/XRS.2431
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“Molecular spectroscopy study of human tooth tissues affected by high dose of external ionizing radiation (caused by the nuclear catastrophe of the Chernobyl plant)”. Darchuk LA, Zaverbna LV, Worobiec A, Van Grieken R page 349 (2012).
Keywords: H1 Book chapter; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation); Laboratory Experimental Medicine and Pediatrics (LEMP)
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“Water quality assessment in Pangani river basin, Tanzania : natural and anthropogenic influences on concentrations of nutrients and inorganic ions”. Hellar-Kihampa H, De Wael K, Lugwisha E, Van Grieken R, International journal of river basin management 11, 55 (2013). http://doi.org/10.1080/15715124.2012.759119
Abstract: The ongoing rapid expansions of human activities and population dynamics have potential impact on the environmental quality of the Pangani river basin, one of the largest water resources in Tanzania, including possible loadings of different kinds of micro-contaminants. However, specific extents of the impacts are rather not well investigated. In this work, we assessed the environmental quality of the basin, based on seasonal characterisation of physicochemical water and sediments parameters, dissolved inorganic ions and nutrient loads. The contributions of geochemical processes and land-use practices were evaluated by multivariate correlations and principal component analysis (PCA). Hierarchical cluster analysis was used to classify similar water quality stations and identify the most and least enriched ones. Surface waters were slightly alkaline, characterised by low total dissolved solids (48652 mg/L). Extremely low oxygen concentration (2.0 mg/L) was also a cause of concern at one station. The Na+ and HCO3 − ions provided the dominant cation and anion, respectively. PCA identified weathering of carbonate and Na+ bearing rocks, gypsum dissolution and atmospheric deposition of sea-salt as the major factors controlling the ionic composition, contributing more than 60% of the spatial variance. Concentration profiles of the chemical species showed a generally low level of anthropogenic inputs, except at a few locations where nitrate and nitrite were significantly enriched above the limits of safe exposure, with patterns indicating influences of farming and livestock keeping. A seasonal difference was observed, with lower ion concentrations during the rainy season, likely due to the dilution effect of increased water discharge. The study provides new insights into the environmental quality of the basin, and indicates the need for continuous monitoring and assessment of the chemical species in the area.
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1080/15715124.2012.759119
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“X-ray optics for synchrotron-radiation-induced X-ray micro fluorescence at the european synchrotron-radiation facility, Grenoble”. Vincze L, Janssens K, Adams F, Institute of physics conference series , 613 (1993)
Abstract: Different optical designs for generating synchrotron x-ray micro beams suitable for use in an X-ray fluorescence microscope using an ESRF bending magnet X-ray source are compared. Attention is devoted to the spatial and energy distribution of the photons in the micro beam and to the minimum detection limits that are achievable with each alternative optical system.
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
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“Quantitative mu-XRF analysis of heterogeneous samples”. Vincze L, Janssens K, Adams F, Jones K, Microbeam Analysis 1995: Proceedings Of The 29th Annual Conference Of The Microbeam Analysis Society , 175 (1995)
Keywords: P1 Proceeding; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
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“Parameters influencing focussing capabilities of capillary optics”. Vincze L, Janssens K, Adams F, Larsson S, Rindby A, Engstrom P, Microbeam Analysis 1995: Proceedings Of The 29th Annual Conference Of The Microbeam Analysis Society , 161 (1995)
Keywords: P1 Proceeding; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
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“A laboratory mu-XRF spectrometer employing capillary optics”. Janssens K, Vekemans B, Rindby A, Vincze L, Adams F, , 159 (1995)
Keywords: P1 Proceeding; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
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“Synchrotron radiation induced X-ray microfluorescence analysis”. Janssens K, Vincze L, Vekemans B, Aerts A, Adams F, Jones KW, Knöchel A, Microchimica acta
T2 –, 4th Workshop of the European-Microanalysis-Society on Modern, Developments and Applications in Microbeam Analysis, MAY, 1995, ST MALO, FRANCE , 87 (1996)
Abstract: mu-XRF is the microscopic equivalent of the well-established multielement analytical technique. In this paper, after comparing the interaction of X-ray photons, electrons and protons with matter and an introduction to synchrotron rings and microfocussing of X-rays, the instrumentation for mu-XRF is discussed, both for laboratory source and synchrotron based setups and the analytical characteristics of mu-XRF are contrasted to that of other microanalytical techniques, Also, this issue of quantification of mu-XRF data is addressed; the applicability of the method in archeological and geological analysis is illustrated.
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
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