Abstract: Laser Microprobe Mass Analysis (LAMMA) was used in a preliminary study to characterize aerosol particles from a beach and inland sites and from a heavily industrialized area. As many as six types of both positive and negative mass spectra with different inorganic and organic signals could be distinguished in the different particle size ranges. Information about the elemental composition and the speciation of S and N was obtained. With increasing distance from sea, progressive uptake of nitrate in seasalt particles was found. Complex particles, containing soot and organic ammonium sulfate, were also detected.

Abstract: On aerosol and rain water samples, collected in the Southern Bight of the North Sea, single particle analyses were performed using both laser microprobe mass analysis and electron-probe X-ray microanalysis in combination with an automated image analysis system. In the aerosols collected from an air mass that had travelled from the Atlantic Ocean along the coast of North France, pure seasalt constituted the most abundant particle type, while aluminosilicates (mostly spherical fly-ash particles) amounted to about 20% and mixed seasalt/aluminosilicate, carbonaceous particles, CaSO4 and spherical iron oxides contributed each 510 %. In air masses that had a longer residence time over the continent, spherical iron oxides, carbonaceous particles and ammonium sulfates together made up 70 % of the total particle load. Seasalt particles were nearly all enriched in sulfate or nitrate, but they were seen to be washed out efficiently after a rain shower. In rain water, some 40 % of the particles appeared to be spherical or irregularly shaped aluminosilicates, from fly-ash and dust dispersal, but more than 50 % consisted of SiO2. The high relative abundance of these particles in rain water may be the result of Al leaching from fly-ash, or of more efficient scavenging by rain droplets.

Abstract: Bilayers of carbon, consisting of a layer of natural carbon and a second layer highly enriched in 13C, were investigated with the LAMMA 500-® instrument. When such a bilayer is perforated by the laser beam, comparable amounts of 12C and 13C are evaporated and partly ionized so that geometry effects and recombination reactions during laser-induced ionization can straightforwardly be studied.

Abstract: Laser Microprobe Mass Spectrometry (LAMMA) is used to examine micrometric particles of calcium oxyanion salts (CaCO3, CaSO4, CaSO4·2H2O) and calcium oxide, in both the positive and negative ion mode. The major molecular ions, appearing in the positive mass spectrum, can be divided into three series, namely CamOm-1+, (CaO)m+ and (CaO)mH+ (m = 1-4). In the case of the former two series the relative intensities of the mass peaks as a function of the fragment valence K = (1 + 2n)/m, for CamOn+, can be fitted to a Gaussian distribution curve, as was earlier demonstrated for secondary ion mass spectrometry. The high stability of the (CaO)mH+ series can be explained by the favourable fragment valence of +2 corresponding to the usual oxidation state of calcium.

Abstract: The major threat to clean air in developed and industrializing countries is now posed by traffic emissions. The effects of traffic road modifications on the air quality are, however, rarely reported in the literature. The aim of this study was to determine the influence of the modernization and renovation of a traffic artery in the region of Mortsel (Antwerp, Belgium) on the concentration of volatile organic compounds such as: benzene, toluene, ethylbenzene and m-, p-, o-xylenes (BTEX). The original goal of the reconstruction works was to reduce the traffic lanes of one of the busiest streets in Antwerp, in order to discourage the road traffic and in consequence also to improve the air quality in this region. The average concentrations of BTEX before these works in 2003 were: 1.6, 7.0, 0.9, 2.3, and 0.9 ìg/m3, for benzene, toluene, ethylbenzene, m + p xylenes, and o-xylene, respectively. However, after the completion of the works, in 2005, they were slightly higher: 2.5, 9.5, 1.6, 3.4, and 1.3 ìg/m3, respectively. The scatter plots of benzene against toluene, ethylbenzene and xylenes in 2003 and 2005 showed very good correlations. This fact indicated that all of the measured compounds originated from the same source, namely the road traffic. Moreover, the data obtained from an air-monitoring station at less than 6 km distance from the sampling site (operated by the Flemish Environment Agency, and located in Borgerhout, Antwerp), confirmed the lack of influence of background concentrations of BTEX. The obtained results led to the conclusion that the reduction of the number of traffic lanes had apparently increased the traffic jams and also increased the emission from cars. Therefore, these modernization works had even a negative impact on the local concentration of traffic-related pollutants as BTEX.

Abstract: The valuable properties of carbon steel slag are currently underexploited. To date, research mainly focusses on valorising a single property of the slag. In this study an ex-ante life cycle assessment (LCA) was applied to evaluate the environmental profile of a novel technological pathway aimed at the extraction of chromium from carbon steel slag in combination with high quality valorisation of the residual matrix material. A comparison with current practice was made, not only by calculating the environmental impact of the lab scale observations, but more importantly by estimating the impact on an industrial scale. Practical guidance on ex-ante LCA is limited, so this study contributes by incorporating simulations on thermodynamic behaviour, complemented with empirical calculation rules and including information derived from similar technologies to perform the upscaling. These principles of ex-ante LCA were applied to the lab results of two consecutive research iterations. Substantial improvements of the environmental profile were observed: ex-ante results turned out to be a factor 20 lower compared to the results from the lab observations after the first iteration and had decreased by a factor 2 compared to the small pilot scale of the second iteration. All upscaled results are better than those from the worst case reference scenario (landfill). Based on the experience gained after this iterative research cycle, a practical recommendation is that at a low technology readiness level using more simple calculation rules in combination with a flowsheet based on elementary design principles for processes at an industrial scale is a more efficient way of modelling compared to a fully-fledged process design from the start.

Abstract: Biomass is expected to play an increasingly significant role in the greening of energy supply. Nevertheless, concerns are rising about the sustainability of large-scale energy crop production. Impacts must be assessed carefully before deciding whether and how this industry should be developed, and what technologies, policies and investment strategies should be pursued. There is need for a comprehensive and reliable sustainability assessment tool to evaluate the environmental, social and economic performance of biomass energy production. This paper paves the way for such a tool by analysing and comparing the performance and applicability of a selection of existing tools that are potentially useful for sustainability assessment of bioenergy systems. The selected tools are: Criteria And Indicators (C&I), Life Cycle Assessment (LCA), Environmental Impact Assessment (EIA), Cost Benefit Analysis (CBA), Exergy Analysis (EA) and System Perturbation Analysis (SPA). To evaluate the tools, a framework was constructed that consists of four evaluation levels: sustainability issues, tool attributes, model structure, area of application. The tools were then evaluated using literature data and with the help of a Delphi panel of experts. Finally, a statistical analysis was performed on the resulting data matrix to detect significant differences between tools. It becomes clear that none of the selected tools is able to perform a comprehensive sustainability assessment of bioenergy systems. Every tool has its particular advantages and disadvantages, which means that trade-offs are inevitable and a balance must be found between scientific accuracy and pragmatic decision making. A good definition of the assessment objective is therefore crucial. It seems an interesting option to create a toolbox that combines procedural parts of C&I and EIA, supplemented with calculation algorithms of LCA and CBA for respectively environmental and economic sustainability indicators. Nevertheless, this would require a more comprehensive interdisciplinary approach to align the different tool characteristics and focuses.

Abstract: Micro-and nanoscopic X-ray techniques were used to investigate the relationship between uranium (U) tissue distributions and adverse effects to the digestive tract of aquatic model organism Daphnia magna following uranium nanoparticle (UNP) exposure. X-ray absorption computed tomography measure-ments of intact daphnids exposed to sublethal concentrations of UNPs or a U reference solution (URef) showed adverse morphological changes to the midgut and the hepatic ceca. Histological analyses of exposed organisms revealed a high proportion of abnormal and irregularly shaped intestinal epithelial cells. Disruption of the hepatic ceca and midgut epithelial tissues implied digestive functions and intestinal barriers were compro-mised. Synchrotron-based micro X-ray fluorescence (XRF) elemental mapping identified U co-localized with morphological changes, with substantial accumulation of U in the lumen as well as in the epithelial tissues. Utilizing high-resolution nano-XRF, 400-1000 nm sized U particulates could be identified throughout the midgut and within hepatic ceca cells, coinciding with tissue damages. The results highlight disruption of intestinal function as an important mode of action of acute U toxicity in D. magna and that midgut epithelial cells as well as the hepatic ceca are key target organs.

Abstract: Four x-ray techniques: computed radiography, emission radiography, energy-resolved radiography and imaging x-ray fluorescence were compared using four mock-up panel paintings. The paintings have different stratigraphy and pigments and are representative for different historical periods. One of the paintings has a hidden underlying painting. The type of pigments used mainly influences the information obtained by both the emission and absorption measurements; high-Z white pigment and high-Z color pigments giving the best contrast. Each of the techniques revealed interesting aspects of the paintings, but none of them could reveal the hidden painting to a satisfactory level. Due to the statistical quality of the spectral data, x-ray fluorescence gives elemental images with high contrast. The radiographic images are better to reveal the internal structure. Imaging x-ray fluorescence and energy-resolved radiography measurements can be done simultaneously, and the combination has the highest potential for the study of complex multilayer paintings. Copyright (c) 2015 John Wiley & Sons, Ltd.

Abstract: It was recently shown that a chiral topological phase emerges from the coupling of two twisted monolayers of superconducting Bi2Sr2CaCu2O8+delta for 2 Sr 2 CaCu 2 O 8 +delta for certain twist angles. In this work, we reveal the behavior of such twisted superconducting bilayers with d x 2 – y 2 pairing symmetry in the presence of an applied magnetic field. Specifically, we show that the emergent vortex matter can serve as a smoking gun for the detection of topological superconductivity in such bilayers. Moreover, we report two distinct skyrmionic states that characterize the chiral topological phase and provide a full account of their experimental signatures and their evolution with the twist angle.