Abstract: Large river catchments with mixed land use capture pesticides from many sources, and degradable pesticides are converted during downstream transport. Unravelling the contribution of pesticide source and the effect of degradation processes is a challenge in such areas. However, insight and understanding of the sources is important for targeted managen-lent, especially when water is abstracted from the river for drinking water production. The river Meuse is such a case. A long-term monitoring data set was applied in a modelling approach for assessing the contribution of waste water treatment plants (WWTPs) and tributaries (sub-basins) to surface water contamination, and to evaluate the effect of decay on the downstream concentrations of glyphosate and AMPA at the point of drinking water abstraction. The results show that WWTPs are important contributors for glyphosate and AMPA in large river catchments with mixed land uses. In the studied area, the river Meuse in the Netherlands, the relative contribution of WWTP effluents is above 29% for glyphosate and around 12% for AMPA. Local industries are found to be potentially big contributors of AMPA. Glyphosate entering the river system is gradually converted to AMPA and other degradation-productions, which results in downstream loads that are considerably lower than the sum of all influxes. In summer when the travel time is longer due to lower discharge, the first order decay of glyphosate in the river Meuse is estimated to result in about 50% reduction of the downstream glyphosate concentrations over a river stretch of 250 km. The contribution of glyphosate decay to the observed AMPA concentrations ranges between 2% and 10%. Contributions are sensitive to seasonal variations in discharge that influence the concentrations through dilution and degradation. (C) 2016 Elsevier B.V. All rights reserved.

Abstract: Field water flow processes can be precisely delineated with proper sets of soil hydraulic properties derived from in situ and/or laboratory experiments. In this study we analyzed and compared soil hydraulic properties obtained by traditional laboratory experiments and inverse optimization tension infiltrometer data along the vertical direction within two typical Podzol profiles with sand texture in a potato field. The main goal was to identify proper sets of hydraulic parameters and to evaluate their relevance on hydrological model performance for irrigation management purposes. Tension disc infiltration experiments were carried out at four and five different depths for both profiles at consecutive negative pressure heads of 12, 6, 3 and 0.1 cm. At the same locations and depths undisturbed samples were taken to determine Mualem-van Genuchten (MVG) hydraulic parameters (theta(r), residual water content, theta(s), saturated water content, alpha and n, shape parameters and K-ls, saturated hydraulic conductivity) in the laboratory. Results demonstrated horizontal differences and vertical variability of hydraulic properties. The tension disc infiltration data fitted well in inverse modeling using Hydrus 2D/3D in combination with final water content at the end of the experiment, theta(f). Four MVG parameters (theta(s), alpha, n and field saturated hydraulic conductivity K-fs) were estimated (theta(r) set to zero), with estimated K-ls and alpha values being relatively similar to values from Wooding's solution which used as initial value and estimated theta(s) corresponded to (effective) field saturated water content, theta(f). The laboratory measurement of K-ls yielded 2-30 times higher values than the field method K-fs from top to subsoil layers, while there was a significant correlation between both K-s values (r = 0.75). We found significant differences of MVG parameters theta(s), n and alpha values between laboratory and field measurements, but again a significant correlation was observed between laboratory and field MVG parameters namely K-s, n, theta(s) (r >= 0.59). Assessment of the parameter relevance in 1-D model simulations, illustrated that the model over predicted and under predicted top soil-water content using laboratory and field experiments data sets respectively. The field MVG parameter data set resulted in better agreement to observed soil-water content as compared to the laboratory data set at nodes 10 and 20 cm. However, better simulation results were achieved using the laboratory data set at 30-60 cm depths. Results of our study do not confirm whether laboratory or field experiments data sets are most appropriate to predict soil water fluctuations in a complete soil profile, while field experiments are preferred in many studies. (C) 2016 Elsevier B.V. All rights reserved.

Abstract: Towards the development of novel drug carriers for oral delivery of poorly soluble drugs mesoporous aerogel carbons (CAs), namely CA10 and CA20 with different pore sizes (10 and 20 nm, respectively), were evaluated. The non-steroidal anti-inflammatory lipophilic compound ibuprofen was incorporated via passive loading. The drug loaded carbon aerogels were systemically investigated by means of High-Resolution Transmission Electron Microscopy (HR-TEM), Nitrogen physisorption studies, X-ray diffraction (XRD), Differential Scanning Calorimetry (DSC), X-ray photon electron spectroscopy (XPS) and zeta-potential studies. In vitro release studies were performed in simulated intestinal fluids reflecting both fasted (FaSSIF) and fed (FeSSIF) state conditions. Cytotoxicity studies were conducted with human intestinal cells (Caco-2). Drug was in an amorphous state in the pores of the carbon carrier as shown from the physicochemical characterization studies. The results showed marked differences in the release profiles for ibuprofen from the two aerogels in the media tested whereas in vitro toxicity profiles appear to be compatible with potential therapeutic applications at low concentrations. (C) 2016 Elsevier B.V. All rights reserved.

Abstract: One of the most striking but unexplained phenomena in the natural degradation of glass is the transformation of an almost colorless, transparent and homogeneous glass into a colored, opaque and heterogeneous degradation layer. In many cases, the degradation layer consists of numerous lamellae with a thickness between 0.1 and 10 pm. However, both internal structure and formation proess of laminated degradation layers remain unclear. In this paper, a model is proposed where we assume that transformed (degraded) glass consists of a random packing of nano-sized silica particles while the lamellae are the result of different packing densities. The model is able to connect the texture of numerous lamellae observed by several types of microscopic techniques with the structure at molecular level determined by means of chemical analysis. In addition, the model is able to explain numerous properties such as the parameters responsible for the contrast between lamellae. This contrast can be caused by differences in color, density, elemental composition, or surface roughness. (C) 2016 Elsevier B.V. All rights reserved.

Abstract: In this paper a structure-activity and structure-selectivity relation is established for three commercial TiO2 sources (P25, P90, and PC500). Morphological and electronic parameters of the photocatalysts are determined using widely applicable and inexpensive characterization procedures. More specifically, the electronic properties are rigorously characterized using an electron titration method yielding quantitative information on the amount of defect sites present in the catalyst. Surface photovoltage measurements on the other hand provide complementary information on the charge carrier recombination process. As model reaction, the degradation of a solid layer of stearic acid is studied using an in situ FTIR reaction cell that enables to investigate the catalyst surface and possible formation of reaction intermediates while the reactions are ongoing. We show that the order of photocatalytic conversion is PC500 > P90 > P25, matching the order of favorable morphological properties. In terms of selectivity to CO2 formation (complete mineralization), however, this trend is reversed: P25 > P90 > PC500, now matching the order of advantageous electronic properties, i.e. low charge carrier recombination and high charge carrier generation. With this we intend to provide new mechanistic insights using a wide variety of physical, (wet) chemical and operando analysis methods that aid the development of performant (self-cleaning) photocatalytic materials.

Abstract: A novel multi-tube photoreactor is presented with a high efficiency (over 90% conversion) toward the degradation of acetaldehyde in air under UV conditions with an incident intensity of 2.1 mW cm−2. A CFD model was developed to simulate the transient adsorption and photocatalytic degradation processes of acetaldehyde in this reactor design and to estimate the corresponding kinetic parameters through an optimization routine using the experimentally determined outlet concentration profiles. The CFD model takes into account the entire reactor geometry and all relevant flow parameters, in contrast to analytical methods that often oversimplify the physical and chemical process characteristics. Using CFD, we show that both adsorption and desorption rate constants increase by respectively one and two orders of magnitude when the UV light is switched on, which clearly affects the transient behavior. The agreement of the experimental and modelled concentration profiles is excellent as evidenced by a coefficient of determination of at least 0.965. To demonstrate the reliability and accuracy of all parameters obtained from the modelling approach, an ultimate validation test was performed using other conditions than the ones used for estimating the kinetic parameters. The model was able to accurately simulate simultaneous adsorption, desorption and photocatalytic degradation.

Abstract: A new hydrometallurgical method was investigated for selective leaching of chromium from stainless steel slag (SS slag) consisting of temperature controlled extraction with NaOH in the presence of NaOCl, followed by water leaching. After parameter optimization of the NaOCl-NaOH extraction step, a selective Cr leaching of 68% was reached, while dissolution of matrix materials was low (Al 0.3%, Ca 2.0%, Si 0.4%). The optimum conditions for the investigated system are: 105 degrees C, 6 h, SS slag particle size <63 mu m, mass ratio of NaOH to SS slag 0.13, and 3.3 mmol NaOCl to 1 g SS slag. The described oxidative alkaline leaching process by hypochlorite enables selective recovery of Cr at a significantly lower temperature and required amount of alkaline agent than molten salt or alkaline roasting processes. BaCrO4 was precipitated to purify and concentrate Cr from the leachate in which also minor amounts of Mn and V were present. This method allowed for a 99.9% Cr recovery rate. The obtained leaching residue shows no alterations of the SS slag's mineralogy with respect to untreated material. Therefore, a known carbonation treatment of the slag can be applied to prepare novel construction materials with a lowered Cr content. (C) 2016 Elsevier B.V. All rights reserved.

Abstract: The true function of neuroglobin (Ngb) and, particularly, human Ngb (NGB) has been under debate since its discovery 15 years ago. It has been expected to play a role in oxygen binding/supply, but a variety of other functions have been put forward, including NO dioxygenase activity. However, in vitro studies that could unravel these potential roles have been hampered by the lack of an Ngb-specific reductase. In this work, we used electrochemical measurements to investigate the role of an intermittent internal disulfide bridge in determining NO oxidation kinetics at physiological NO concentrations. The use of a polarized electrode to efficiently interconvert the ferric (Fe3+) and ferrous (Fe2+) forms of an immobilized NGB showed that the disulfide bridge both defines the kinetics of NO dioxygenase activity and regulates appearance of the free ferrous deoxy-NGB, which is the redox active form of the protein in contrast to oxy-NGB. Our studies further identified a role for the distal histidine, interacting with the hexacoordinated iron atom of the heme, in oxidation kinetics. These findings may be relevant in vivo, for example in blocking apoptosis by reduction of ferric cytochrome c, and gentle tuning of NO concentration in the tissues.

Abstract: Piezo- and flexoelectricity are manifestations of electromechanical coupling in solids with potential applications in nanoscale materials. Naumov etal. [Phys. Rev. Lett. 102, 217601 (2009)] have shown by first principles calculations that a monolayer BN sheet becomes macroscopically polarized in-plane when in a corrugated state. Here, we investigate the interplay of layer corrugation and in-plane polarization by atomistic lattice dynamics. We treat the coupling between static flexural modes and in-plane atomic ion displacements as an anharmonic effect, similar to the membrane effect that is at the origin of negative thermal expansion in layered crystals. We have derived analytical expressions for the corrugation-induced static in-plane strains and the optical displacements with the resulting polarization response functions. Beyond h-BN, the theory applies to transition metal dichalcogenides and dioxides. Numerical calculations show that the effects are considerably stronger for 2D h-BN than for 2H-MoS2.

Abstract: A polycrystalline sample of SrLa2Ni2TeO9 has been synthesized using a standard ceramic method and characterized by neutron diffraction, magnetometry and electron microscopy. The compound adopts a monoclinic, perovskite-like structure with space group P2(1)/n in and unit cell parameters a=5.6008(1), b = 5.5872(1), c=7.9018(2) angstrom, p=90.021(6)degrees at room temperature. The two crystallographically-distinct B sites are occupied by Ni2+ and Te6+ in ratios of 83:17 and 50:50. Both ac and dc magnetometry suggest that the compound is a spin glass below 35 K but the neutron diffraction data show that some regions of the sample are antiferromagnetic. Electron microscopy revealed twinning on a nanoscale and local variations in composition. These defects are thought to be responsible for the presence of two distinct types of antiferromagnetic ordering. (C) 2016 The Authors. Published by Elsevier Inc.

Abstract: Periodic mesoporous organosilicas provide the best of two worlds: the strength and porosity of an inorganic framework combined with the infinite possibilities created by the organic bridging unit. In this work we focus on post-synthetical modification of benzene bridged PMO, in order to create bromobenzene PMO. In the past, this proved to be very challenging due to unwanted structural deterioration. However, now we have found a way to brominate this material whilst keeping the structure intact. In-depth structural analysis by solid state NMR and XPS shows both vast progress over previous attempts as well as potential for improvement.

Abstract: Nanocrystalline indium oxide films with extremely small grains in range of 7-40 nm are prepared by sol-gel method. The influence of grain size on the sensitivity of indium oxide to nitrogen dioxide in low concentration at room temperature is investigated under the UV illumination and without illumination. The sensitivity increases with the decrease of grain sizes when In2O3 is illuminated while in the dark In2O3 with intermediate grain size exhibits the highest response. An explanation of the different behavior of the In2O3 with different grain size sensitivity to NO2 under illumination and in the dark is proposed. We demonstrate that pulsed illumination may be used for NO2 detection at room temperature that significantly reduces the power consumption of sensor. (C) 2016 Elsevier B.V. All rights reserved.

Abstract: The conventional treatment of municipal wastewater by means of activated sludge is typically energy demanding. Here, the potential benefits of: (1) the optimization of mesophilic digestion; and (2) transitioning to thermophilic sludge digestion in three wastewater treatment plants (Tilburg-Noord, Land van Cuijk and Bath) in the Netherlands is evaluated, including a full-scale trial validation in Bath. In Tilburg-Noord, thermophilic sludge digestion covered the energy requirements of the plant (102%), whereas 111% of sludge operational treatment costs could be covered in Bath. Thermophilic sludge digestion also resulted in a strong increase in nutrient release. The potential for nutrient recovery was evaluated via: (1) stripping/absorption of ammonium; (2) autotrophic removal of ammonium via partial nitritation/anammox; and (3) struvite precipitation. This research shows that optimization of sludge digestion may lead to a strong increase in energy recovery, sludge treatment costs reduction, and the potential for advanced nutrient management in full-scale sewage treatment plants. (C) 2016 Elsevier Ltd. All rights reserved.

Abstract: In the present paper, we consider the bulky knots and bulky links that appear after cutting of generalized MöbiusListing GML 4 n bodies (with corresponding radial cross sections square) along different generalized MöbiusListing surfaces GML 2 n situated in it. The aim of this article is to examine the number and geometric structure of independent objects that appear after such a cutting process of GML 4 n bodies. In most cases, we are able to count the indices of the resulting mathematical objects according to the known tabulation for knots and links of small complexity.

Abstract: Utilization of Au and nanocrystalline diamond ( NCD) as interlayers noticeably modifies the microstructure and field electron emission ( FEE) properties of hexagonal boron nitride nanowalls ( hBNNWs) grown on Si substrates. The FEE properties of hBNNWs on Au could be turned on at a low turn-on field of 14.3V mu m(-1), attaining FEE current density of 2.58mAcm(-2) and life-time stability of 105 min. Transmission electron microscopy reveals that the Au-interlayer nucleates the hBN directly, preventing the formation of amorphous boron nitride ( aBN) in the interface, resulting in enhanced FEE properties. But Au forms as droplets on the Si substrate forming again aBN at the interface. Conversely, hBNNWs on NCD shows superior in life-time stability of 287 min although it possesses inferior FEE properties in terms of larger turn-on field and lower FEE current density as compared to that of hBNNWs-Au. The uniform and continuous NCD film on Si also circumvents the formation of aBN phases and allows hBN to grow directly on NCD. Incorporation of carbon in hBNNWs from the NCD-interlayer improves the conductivity of hBNNWs, which assists in transporting the electrons efficiently from NCD to hBNNWs that results in better field emission of electrons with high life-time stability. (C) 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim