Abstract: Mass spectrometry identifies the atomic mass of molecules and fragments in the gas phase. The spectrometer ionizes the molecules that then pass through an electric or magnetic field towards a detector. The field modifies the molecule's trajectory and we infer mass from its direction and velocity in a static field or from the stability of its path in a dynamic field. The electric current is amplified and a mass spectrum is generated from the location or timing of the signal from the detector, translated into a plot of the intensity as a function of the mass‐over‐charge ratio. It is field deployable, measures concentrations in real time with a temporal resolution better than 100 ms, and detection limits of fg. However, the signal drifts with time so we have to calibrate it as frequently as every hour. Calibrating requires multiple mixtures with varying concentrations to map the non‐linear response. The Web of Science Core Collection indexed over 60 000 articles that refer to MS (2016 and 2017) with applications ranging from permanent gas analysis, to identifying protein, forensic science, and natural products. The bibliometric software VOSViewer(2010) identified four clusters of research related to MS: (1) proteomics, proteins, plasma, and metabolomics; (2) solid phase extraction together with gas chromatography; (3) tandem mass spectrometry and liquid chromatography; and (4) waste water and toxicity. We expect that the technique will continue to evolve with increased sensitivity, lower drift, and greater specificity. Miniaturization efforts should also continue in order to develop faster field deployable instruments.

Abstract: The application of micro-Raman spectroscopy is discussed for the analysis of structural features of human tooth tissues affected by high doses of external ionizing radiation (0.51.7 Gy) after the nuclear plant catastrophe in Chernobyl in 1986. The results have shown significant changes in the mineral matrix of dental enamel that lead to the decrease of tooth enamel hardness. Destruction of the collagen chain of the organic matrix has been observed for dentin and cementum.

Abstract: Using spin- and angle-resolved photoemission spectroscopy and relativistic many-body calculations, we investigate the evolution of the electronic structure of (Bi1-xInx)(2)Se-3)(2)Se-3 bulk single crystals around the critical point of the trivial to topological insulator quantum-phase transition. By increasing x, we observe how a surface gap opens at the Dirac point of the initially gapless topological surface state of Bi2Se3, leading to the existence of massive fermions. The surface gap monotonically increases for a wide range of x values across the topological and trivial sides of the quantum-phase transition. By means of photon-energy-dependent measurements, we demonstrate that the gapped surface state survives the inversion of the bulk bands which occurs at a critical point near x = 0.055. The surface state exhibits a nonzero in-plane spin polarization which decays exponentially with increasing x, and which persists in both the topological and trivial insulator phases. Our calculations reveal qualitative agreement with the experimental results all across the quantum-phase transition upon the systematic variation of the spin-orbit coupling strength. A non-time-reversal symmetry-breaking mechanism of bulk-mediated scattering processes that increase with decreasing spin-orbit coupling strength is proposed as explanation.

Abstract: Combining first-principles calculations with Landauer-Mittiker formalism, ballistic thermoelectric transport properties of semiconducting two-dimensional transition metal dichalcogenides (TMDs) and oxides (TMOs) (namely MX2 with M = Cr, Mo, W, Ti, Zr, Hf; X = O, S, Se, Te) are investigated in their 2H and 1T phases. Having computed structural, as well as ballistic electronic and phononic transport properties for all structures, we report the thermoelectric properties of the semiconducting ones. We find that 2H phases of four of the studied structures have very promising thermoelectric properties, unlike their 1T phases. The maximum room temperature p-type thermoelectric figure of merit (ZT) of 1.57 is obtained for 2H-HfSe2, which can be as high as 3.30 at T = 800 K. Additionally, 2H-ZrSe2, 2H-ZrTe2, and 2H-HfS2 have considerable ZT values (both nand p-type), that are above 1 at room temperature. The 1T phases of Zr and Hf-based oxides possess relatively high power factors, however their high lattice thermal conductance values limit their ZT values to below 1 at room temperature.

Abstract: High-rate activated sludge processes allow for the recovery of organics and energy from wastewaters. These systems are operated at a short sludge retention time and high sludge-specific loading rates, which results in a higher sludge yield and better digestibility than conventional, low-rate activated sludge. Little is known about the microbial ecology of high-rate systems. In this work, we address the need for a fundamental understanding of how high-rate microbial communities differ from low-rate communities. We investigated the high-rate and low-rate communities in a sewage treatment plant in relation to environmental and operational variables over a period of ten months. We demonstrated that (1) high-rate and low-rate communities are distinctly different in terms of richness, evenness and composition, (2) high-rate community dynamics are more variable and less shaped by deterministic factors compared to low-rate communities, (3) sub-communities of continuously core and transitional members are more shaped by deterministic factors than the continuously rare members, both in high-rate and low-rate communities, and (4) high-rate community members showed a co-occurrence pattern similar to that of low-rate community members, but were less likely to be correlated to environmental and operational variables. These findings provide a basis for further optimization of high-rate systems, in order to facilitate resource recovery from wastewater.

Abstract: The latest life-cycle assessment methods account for land use, due to the production, use and disposal of products and services, in terms of ecosystem damage. The process of brownfield remediation converts otherwise idle urban space into productive space. The value to ecosystems in this context is of course limited since the brownfield site remains urban. When evaluating brownfield remediation technologies, the availability of space on-site is dependent on the duration of time required by the remediation technology to reach the remediation target. Remediation technology alternatives tend to vary largely in terms of duration. Comparative life-cycle assessments of remediation technologies, to date, present the large variations between alternatives in terms of remediation duration but do not translate this into an impact or parameter. The restored subsurface zone is often defined as a functional unit, when in fact the surface area is the resource restored by the remediation service. The economic benefits of making land resources available are particularly important considerations in the context of brownfield remediation. The research proposes an innovative impact assessment approach that allows land to be considered as a finite resource. The method is applied in a comparative life-cycle assessment of two potential remediation scenarios for an idle brownfield in the Brussels region of Belgium. The results show that there is a trade-off between greenhouse gas emissions and land availability and that both are largely dependent on the efficiency of the contaminant extraction mechanism. The results also raise the question as to whether the economic valuation of land, like precious metals and fossil fuels, provides an accurate reflection of the true value of the resource. Considering land as a resource at the midpoint level is also relevant in other urban contexts where competition exists between different land-uses, where urban sprawl is detrimental to undeveloped areas and where urban intensification is a policy objective. (C) 2015 Elsevier Ltd. All rights reserved.

Abstract: The most unique and only known 16th century Antwerp majolica tile floor in Belgium is situated in a tower of the Rameyenhof castle (Gestel, Belgium). This exceptional work of art has recently been investigated in situ by using X-ray fluorescence (XRF) and Raman spectroscopy in order to study the material characteristics. This study reports on the result of the analyses based on the novel combination of non-destructive and portable instrumentation, including a handheld XRF spectrometer for obtaining elemental information and a mobile Raman spectrometer for retrieving structural and molecular information on the floor tiles in the Rameyenhof castle and on a second, similar medallion, which is stored in the Rubens House museum in Antwerp (Belgium). The investigated material, majolica, is a type of ceramic, which fascinated many people and potters throughout history by its beauty and colourful appearance. In this study the characteristic major/minor and trace element signature of 16th century Antwerp majolica is determined and the pigments used for the colourful paintings present on the floor are identified. Furthermore, based on the elemental fingerprint of the white glaze, and in particular on the presence of zinc in the tiles – an element that was not used for making 16th century majolica – valuable information about the originality of the chapel floor and the two central medallions is acquired. (C) 2014 Elsevier B.V. All rights reserved.

Abstract: Sustainable Materials Management (SMM) strategies, such as reuse, recycling and energy recovery aim, to capture more of the embedded resource or material value in products and waste streams. Reuse, recycling and energy recovery are existing activities in every society but they are poorly reflected in official statistics. Reaching higher levels of reuse, recycling and energy recovery may provide economic and environmental opportunities (i.e., in terms of GDP, jobs, reduced impacts), but not all options will have a net win-win-win property in practice, as they reduce the need for producing new commodities. In open economies, many primary resources, components and products are imported from abroad, and many goods produced are exported abroad. This paper describes a top-down methodology for estimating the substitution potential of intensifying specific SMM-strategies and material efficiency strategies. We combined both regional and multi-regional EE-IO (environmentally extended input-output) models to link industrial sectors to SMM-strategies. Our method enables us to compare the different SMM and material efficiency strategies in terms of the maximum available budgets for reaching them on a break even basis, maximum savings in global warming emissions and substituted employment effects, both through a regional and global perspective. We add a case on Flanders (Northern region in Belgium) to illustrate the methodology. Flanders is currently developing a policy for SMM. Selecting new regional actions for a Sustainable Materials Management policy can benefit from a good understanding of the international entangled value chains. It is important to understand how much of the chain is within reach of domestic policies and also to assess the consequences in terms of potential winners and losers, regarding GDP, jobs and environmental impacts, both domestically and abroad. We illustrated the potential outcomes for Flanders from four generic SMM-strategies: energy recovery, food waste prevention, recycling and reuse. From a strict regional self-interest perspective, it is preferable to substitute foreign value chains with local economic activities. Reuse creates by far the largest budget for new activities to realize the strategy (31.2% of Flemish GDP compared to 8.3% for food waste prevention, 6.2% for energy recovery and 4.2% for recycling). All four strategies have similar and significant potentials to reduce greenhouse gas emissions. However, food waste prevention and reuse have higher potentials to reduce Flemish territorial GHG-emissions. From a pure Flemish employment perspective, the energy recovery and recycling strategies could replace the fewest Flemish jobs, and from a global perspective, all strategies most likely imply losses of jobs abroad. (C) 2015 Elsevier B.V. All rights reserved.

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.

Abstract: The integration of the nonlinear least squares X-ray spectrum evaluation progam AXIL. into a mu-PIXE and a mu-XRF setup is discussed. The use of the software when procesing data sets derived from biological and geological samples is described.

Abstract: We study the excitation of spin waves in scaled magnetic waveguides using the magnetoelastic effect. In uniformly magnetized systems, normal strains parallel or perpendicular to the magnetization direction do not lead to spin wave excitation since the magnetoelastic torque is zero. Using micromagnetic simulations, we show that the nonuniformity of the magnetization in submicron waveguides due to the effect of the demagnetizing field leads to the excitation of spin waves for oscillating normal strains both parallel and perpendicular to the magnetization. The excitation by biaxial normal in-plane strain was found to be much more efficient than that by uniaxial normal out-of-plane strain. For narrow waveguides with a width of 200 nm, the excitation efficiency of biaxial normal in-plane strain was comparable to that of shear strain. Published by AIP Publishing.