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International audience; Imaging the structure of a radiative shock is a challenging task as the high plasma densities produced need a short wavelength to penetrate the plasma, requiring highly sophisticated imaging techniques. In a recent paper (Stehlé et al., Opt. Commun. 285 (2012) 64–69 [1]) the feasibility of a novel imaging technique using an X-ray laser (XRL) at 21 nm with a pulse duration 0.15 ns was proved. The recorded image was attributed to a shock propagating with a velocity of ~60 km/s. This velocity is in agreement with measurements of the plasma self-emission using time and space resolved diode diagnostics, and also in qualitative agreement with 1D numerical simulations. However, due to the inhomogeneous reflectivity of the XUV imaging mirror and to the low number of XRL photons, the quality of the recorded image was insufficient to unambiguously identify the different shock regions. Thus, arguing an ad hoc spatial resolution of ~0.5 mm and a stepwise representation of the shock–piston system, the potential of the technique to observe a radiative precursor was contested (Busquet's comment (in press) [2]). In this reply we aim at clarifying different aspects of the experimental setup, spatial resolution and other questions raised in this comment in order to back up our findings together with their respective analysis and interpretations.

Editorial Material; International audience

Recent work showed that carbon nanotubes could be fabricated into bucky-paper structures as self-supporting membranes and their hydrophobic property used for water desalination by membrane distillation. Carbon nanotube bucky-papers possess very interesting properties such as natural hydrophobicity, high porosity and very high specific surface area, making of them promising candidates for separation applications. However, to inhibit crack formation associated with poor mechanical stability, improved durability structures that retain a high degree of hydrophobicity need to be developed. In this work we chemically modified high purity carbon nanotubes by (i) UV/ozone treatment to create hydroxyl groups and (ii) reacting those groups by substitution with alkoxysilane based groups. The resulting nanotubes presented a silicon content up to 2.5% and the bucky-papers produced had larger contact angle (140° compared to 125°) and liquid entry pressures. We report here on their fabrication and use as membranes in direct contact membrane distillation.

In this study, three types of sludge-derived biochars (BC1, BC2 and BC3) were prepared by 1) original sludge, 2) sludge after K2FeO4 conditioning, and 3) sludge after acidification + K2FeO4 conditioning. The results show that the biochar prepared from the conditioned sludge has additional functional groups, and its Pb2+ removal effect is greatly enhanced. The concentration of Pb2+ in the effluent can be reduced to

Supported gold and platinum particles on titanium oxide catalysts were evaluated in the oxidative depolymerization of lignins toward high added value aromatics under mild conditions (T: 150 °C, Pair: 20 bar, CNaOH: 10 g/L, 1 h). Kraft and ethanol Organosolv lignins were engaged in the study. Gold catalyst showed a strong tendency to further oxidize aromatics produced from lignin depolymerization to volatile compounds leading to very low yield in target molecules. On the contrary, platinum-based catalysts were allowed to observe enhanced yields that were attributed to its ability to preserve lignin’s substructure during the reaction. A kinetic model was constructed based on the results observed, which allowed us to identify the occurrence of condensation reactions during lignin oxidation and degradation of the produced aromatic compounds as the main limitations to reach high product yields. Insights on lignin oxidation and the catalyst’s role lead through this study would help to reach higher control over lignin valorization.

International audience; A detailed investigation of the physicochemical properties and thermal characteristics of argan fruit residues (AFRs) was carried out to identify their potential application as biofuels. This experimental study covered the four main by-products of argan fruit: argan pulp (AP), argan nut shell (ANS), argan oilcake (AOC) and argan deoiled cake (ADC). Physicochemical analysis was performed to characterize biomass-based materials. Thermogravimetric techniques (TG, DTG and DTA) were applied to assess structural decomposition, biomass reactivity and combustion parameters. Lastly, thermal conductivity and diffusivity between 25 and 100 °C were measured using the transient plane source technique (TPS). The study shows that heating values were in the range of 17–22.5 MJ kg−1, which is comparable to those of wood pellets and lignite coal. The maximum ash content was found in AP and the minimum in ANS. The residual oil of AOC was found to affect the drying process and calorific value. Thermal analysis showed that ANS has the highest ignition temperature and thermal conductivity values and therefore appears to be the most reactive material. Our data show that ANS has a good potential to produce heat through direct combustion. A pretreatment appears to be necessary to improve the characteristics of AP and AOC in order to make them suitable biofuels in the near future.

International audience; Modular structures are crystal structures built by subperiodic (zero-, mono-or diperiodic) substructures, called modules. The whole set of partial operations relating substructures in a modular structure build up a groupoid; modular structures composed of identical substructures are described by connected groupoids, or groupoids in the sense of Brandt. A general approach is presented to describe modular structures by Brandt's groupoids and how to obtain the corresponding space groups, in which only the partial operations that have an extension to the whole crystal space appear.

The analysis of the photoabsorption spectra of molecules shows that the band maximum is usually redshifted in comparison to the vertical excitation. We conducted a throughout analysis of this shift based on low-dimensional analytical and numerical model systems, showing that its origin is rooted in the frequency change between the ground and the excited states in multidimensional systems. Moreover, we deliver a benchmark of ab initio results for the shift based on a comparison of vertical excitations and band maxima calculated with the nuclear ensemble approach for the 28 organic molecules in the Mülheim molecular dataset. The mean value of the shift calculated over 60 transitions is 0.11 ± 0.08 eV. The mean value of the band width is 0.32 ± 0.14 eV. Graphical abstract. Electronic supplementary material The online version of this article (10.1007/s00894-020-04355-y) contains supplementary material, which is available to authorized users.

The increasing population creates excess pressure on the plantation and production of fruits and vegetables across the world. Consumption demand during the whole year has made production compulsory in the covered production system (greenhouse). Production, harvesting, processing, transporting, and distribution chains of fruit and vegetables have resulted in a huge amount of wastes as an alternative source to produce biofuels. In this study, optimization of two pretreatment processes (NaOH and HCl assisted thermal) was investigated to enhance methane production from fruit and vegetable harvesting wastes (FVHW) that originate from greenhouses. NaOH concentration (0&ndash, 6.5%), HCl concentration (0&ndash, 5%), reaction temperature (60&ndash, 100 &deg, C), solid content (1&ndash, 5%), time of reaction (1&ndash, 5 h), and mixing speed (0&ndash, 500 rpm) were chosen in a wide range of levels to optimize the process in a broad design boundary and to evaluate the positive and negative impacts of independent variables along with their ranges. Increasing NaOH and HCl concentrations resulted in higher COD solubilization but decreased the concentration of soluble sugars that can be converted directly into methane. Thus, the increasing concentrations of NaOH and HCl in the pretreatments have resulted in low methane production. The most important independent variables impacting COD and sugar solubilization were found to be chemical concentration (as NaOH and HCl), solid content and reaction temperature for the optimization of pretreatment processes. The high amount of methane productions in the range of 222&ndash, 365 mL CH4 gVS&minus, 1 was obtained by the simple thermal application without using chemical agents as NaOH or HCl. Maximum enhancement of methane production was 47&ndash, 68% compared to raw FVHW when 5% solid content, 1-hour reaction time and 60&ndash, C reaction temperature were applied in pretreatments.

International audience; Magnetic moment measurements of isomeric states in neutron-rich isotopes populated in photofission using γ-beam facility at the Extreme Light Infrastructure−Nuclear Physics (ELI-NP) laboratory aim at addressing many open questions related to the structure of the nuclei in A around 100 and 130 mass regions. The possibility of such measurements at ELI-NP is briefly discussed here using Geant4 Monte Carlo simulations. The present paper report the estimates of γ-beam profile at the target, fission fragment production rates and the possible target geometry.

Vine shoots are lignocellulosic agricultural residues. In addition to being an interesting source of polyphenols, they can be used as fillers in a poly(3-hydroxybutyrate-3-hydroxyvalerate) (PHBV) matrix to decrease the overall cost and to propose an alternative to non-biodegradable fossil-based materials. The objective of the present work was to investigate how the incorporation of vine shoots fillers and a preliminary polyphenol extraction step could impact the biodegradability of biocomposites. Biocomposites (20 wt %) were produced by microcompounding. The biodegradation of materials was assessed by respirometric tests in soil. The negative impact of polyphenols on the biodegradability of vine shoots was confirmed. This was supported by crystallinity measurements and scanning electron microscopy (SEM) observations, which showed no difference in structure nor morphology between virgin and exhausted vine shoots particles. The incorporation of vine shoots fillers in PHBV slightly accelerated the overall biodegradation kinetics. All the biocomposites produced were considered fully biodegradable according to the French and European standard NF EN 17033, allowing the conclusion that up-cycling vine shoots for the production of lignocellulosic fillers is a promising strategy to provide biodegradable materials in natural conditions. Moreover, in a biorefinery context, polyphenol extraction from vine shoots has the advantage of improving their biodegradability.

In Table 2 of this Full Paper, the units for the turnover frequencies (TOF) are given as 10-13 s-1. The correct units for the TOF are 10-3 s-1. The authors and editorial office apologize for the oversight.

This article describes the observation and determination of -module defects (twins, translation faults and module dislocations) in NiZr by high-resolution electron microscopy (HREM), and scanning transmission electron microscopy bright-field (STEM-BF) and high-angle annular dark-field (STEM-HAADF)., Some specific structures of intermetallic alloys, like approximants of quasicrystals, have their unit cells and most of their atoms located on a periodic fraction of the nodes of a unique -module [a set of the irrational projections of the nodes of a (N > 3-dimensional) lattice]. Those hidden internal symmetries generate possible new kinds of defects like coherent twins, translation defects and so-called module dislocations that have already been discussed elsewhere [Quiquandon et al. (2016 ▸). Acta Cryst. A72, 55–61; Sirindil et al. (2017 ▸). Acta Cryst. A73, 427–437]. Presented here are electron microscopy observations of the orthorhombic phase NiZr – and its low-temperature monoclinic variant – which reveal the existence of such defects based on the underlying -module generated by the five vertices of the regular pentagon. New high-resolution electron microscopy (HREM) and scanning transmission electron microscopy high-angle annular dark-field (STEM-HAADF) observations demonstrate the agreement between the geometrical description of the structure in five dimensions and the experimental observations of fivefold twins and translation defects.

Ted Janssen’s contributions to the field of aperiodic crystals are reviewed., This article reviews some of Ted Janssen’s (1936–2017) major contributions to the field of aperiodic crystals. Aperiodic crystals are long-range ordered structures without 3D lattice translations and encompass incommensurately modulated phases, incommensurate composites and quasicrystals. Together with Pim de Wolff and Aloysio Janner, Ted Janssen invented the very elegant theory of superspace crystallography that, by adding a supplementary dimension to the usual 3D space, allows for a deeper understanding of the atomic structure of aperiodic crystals. He also made important contributions to the understanding of the stability and dynamics of aperiodic crystals, exploring their fascinating physical properties. He constantly interacted and collaborated with experimentalists, always ready to share and explain his detailed understanding of aperiodic crystals.

International audience; Sugar-based surfactants are renewable alternatives to petroleum-based surfactants in many applications such as detergents and cosmetics. However, their molecular structure often gives rise to relatively stable crystals, which can lead to difficulties in dissolving them in water. This phenomenon is characterized by the Krafft temperature (T K), above which the surfactant solubility becomes high enough to induce self-association into micelles. Small changes in the molecular structure can result in large T K differences, which make rationalization and prediction of T K challenging. Few models were proposed in the literature, but none of them are applicable to sugar-based surfactants. In this article, we propose two decision tree models to estimate whether sugar-based surfactants exhibit potential dissolution issues at room temperature (i.e., T K above 25 °C or not). The first one, based on the descriptors of the whole molecule including quantum-chemical ones, was able to correctly classify 86% of the surfactants in the validation set. The second one, built from simple structural counts of the polar headgroup and the alkyl chain, could predict the right class for 78% of the surfactants in the validation set. These classification models account for experimentally known trends between the molecular structure and T K, such as the impact of the polar headgroup size, the alkyl chain length, and the presence of an amide linkage. To the end, our models were applied to a practical case to show how they can help in designing synthesis procedures of new surfactants.

International audience; Membrane fouling remains the major obstacle for development of membrane bioreactors (MBRs). This paper aimed at investigating the effects of carbamazepine (CBZ) present in a discontinuous way at high concentration (peak injection) on fouling propensity of activated sludge from a MBR that treats domestic wastewater. Batch experiments with peak injection of CBZ (100 mu g L-1 in sludge for 3 h) were performed for sludges sampled from a MBR operated under different organic loading conditions. HPLC-SEC analysis with a fluorescence detector was employed to study the effects of CBZ on protein-like compounds in supernatant. With addition of CBZ in sludge, a significant increase of sludge fouling propensity was observed when using sludge sampled from the MBR operated under low organic loading rate (0.1 kg COD/ kg EVESS/d), which could be attributed to the increase in the quantity of protein-like substances with a 100-1000 kDa molecular size in supernatant. Whereas reduced CBZ effect was found for sludge sampled from the MBR operated under higher organic loading rate (0.2 kg COD/kg MLSS/d). Whatever the sludge, the injection of CBZ induced no significant change of the floc size distribution and of the polysaccharide concentration in supernatant. Moreover, it did not affect the sludge microbial activity.

Since solvents of petroleum origin are now strictly regulated worldwide, there is a growing demand for using greener, bio-based and renewable solvents for extraction, purification and formulation of natural and food products. The ideal alternative solvents are non-volatile organic compounds (VOCs) that have high dissolving power and flash point, together with low toxicity and less environmental impact. They should be obtained from renewable resources at a reasonable price and be easy to recycle. Based on the principles of Green Chemistry and Green Engineering, vegetable oils could become an ideal alternative solvent to extract compounds for purification, enrichment, or even pollution remediation. This review presents an overview of vegetable oils as solvents enriched with various bioactive compounds from natural resources, as well as the relationship between dissolving power of non-polar and polar bioactive components with the function of fatty acids and/or lipid classes in vegetable oils, and other minor components. A focus on simulation of solvent-solute interactions and a discussion of polar paradox theory propose a mechanism explaining the phenomena of dissolving polar and non-polar bioactive components in vegetable oils as green solvents with variable polarity. Edinson Yara Varón thanks to fellowship funding (No. TECSPR14-2-0029) from the People Programme (Marie Curie Actions) of the Seventh Framework Programme of the European Union (FP7/2007-2013) under REA grant agreement No. 600388 (TECNIOspring programme), and from the Agency for Business Competitiveness of the Government of Catalonia, ACCIÓ. Ying Li would like to thank the National Natural Science Foundation of China (Grant 31701633) and the Fundamental Research Funds for the Central Universities (Grant 17817028), as well as special funds from “SanWu Talent 2014” and sixth “100-Talent” Programs.

International audience; Auguste Bravais by his fundamental work on lattice has pioneered modern crystallography. He was born in 1811 in Annonay (France) at a short distance from Lyon and Saint-Etienne. He was then educated at the College Stanislas in Paris and entered the École Polytechnique in Paris in 1829. In 1832, he joined the French Navy as an officer and took part at scientific explorations to the Algerian Coast and Northern Europe. In 1837 he defended a PhD in Astronomy at the Faculty of Sciences in Lyon where he became Professor in 1841 to teach mathematics in astronomy. Then, in 1845, he moved at Ecole Polytechnique in Paris to take the chair of Physics, which he held till 1856. He published his first studies dealing with crystal lattice in 1849 in a short paper [1] and later wrote a book where he developed his theory fully based on geometrical theorems [2]. He died prematurely in 1863 exhausted by the loss of his only son. Like many scientists of that time Auguste Bravais was universalist and has been successively astronomer, geologist, mathematician, physicist, mineralogist, and crystallographer as well as an explorer from Lapland to the top of Mont Blanc [3]. In this communication, the steering committee Lyon-Saint-Etienne will recall the contribution of Auguste Bravais to crystallography and will show some aspect of his life that may be less known in our community.

• The presence of nanostructures is demonstrated in a ternary melt of ethanol, 1-heptanol and rapeseed oil.

Despite the several advantages of microfiltration, applications of this separation technique in fruit juice industries have been challenged by its low economical productivity due to membrane fouling. Although several studies aimed to identify operating conditions (e.g. juice pretreatment, crossflow filtration mode, etc.) to achieve acceptable performances, only few studies focused on the fouling propensity of fruit juices and on the identification of their foulant compounds. The aim of this work was to evaluate the fouling behavior of two orange juices and focused on the identification of relevant size-classes of foulant particles. Lab-scale filtration tests were carried out in conjunction with juice size-fractionation with the aim of quantifying the resistance to filtration of the juices. Based on a resistance-in-series approach, size-cartographies of foulant particles that are juice and membrane-specific were built. These cartographies were provided for two mineral membranes M 1.2 and M 0.2 with different average pore diameters (1.2 and 0.2 μm). M 1.2 results showed that the fouling is mainly external for both juices and due to particles larger than 2 µm. In contrast, results concerning M 0.2 filtration tests showed that four different size-classes of fruit juices compounds are involved in different fouling mechanisms. Moreover, the hydraulic reversibility of the fouling mechanisms was evaluated through the impact of shear rate on the measured resistances. It was seen that the fouling was mainly reversible when M 1.2 was used for both juices filtration while it was not the case when juices were filtered with M 0.2 . This information would be interesting to choose the appropriate strategy in order to enhance the microfiltration of these juices at large scale. Moreover, the proposed size-cartography strategy would greatly satisfy the industrial demand for practical tool to identify the different size-classes of compounds governing the overall membrane fouling.

In olive-oil-producing countries, large amounts of waste material are generated as by-product for which there is no ready use and in some cases may have a negative value because of the cost of disposal. Most of these countries depend on fossil fuels for their energy uses, and olive mill wastes can be used to supplement such energy sources using thermochemical conversion processes such as pyrolysis. However, efficient operation of thermochemical conversion systems requires a thorough understanding of the influence of the composition and thermal properties of these by-products on their behaviour during the conversion process. In this study, the thermal behaviour of two olive mill wastes samples (olive mill solid waste: OMSW, and concentrated olive mill wastewater: COMWW) was examined at different heating rates ranging from 5 to 50 A degrees C min(-1) in inert atmosphere using the technique of thermogravimetric analysis. As the increment of heating rates, the variations of characteristic parameters from the TG-DTG curves were determined. The initial temperature of degradation is higher in OMSW, which present a high amount of cellulose in comparison with COMWW. Three methods were used for the determination of kinetic reaction parameters: Friedman, Ozawa-Flynn-Wall and Vyazovkin methods. The results showed that apparent activation energy obtained for the decomposition of hemicelluloses and cellulose derived from OMSW was given as 150-176 and 210.5-235.7 kJ mol(-1), while for COMWW, the values were 133-145 and 255-275 kJ mol(-1), respectively.

International audience; Zinc Oxide (ZnO) and graphene (G) have been extensively studied because of their unique physical properties. Here, Graphene-Zinc Oxide (G/ZnO) nanolaminates were fabricated, respectively, by chemical vapor deposition and low temperature atomic layer deposition technique. The number of obtained G/ZnO layers was tuned from 1 to 11 with a total thickness of 100 nm for all prepared nanolaminates. The structure, optical properties and interaction between G and ZnO were studied by X-ray methods, TEM, AFM, Raman and optical spectroscopy. The obtained results were interpreted and analysed taking into account strain and charge effects of graphene in G/ZnO nanostructures. We demonstrate that the bottom graphene used as a substrate stimulated the formation of ZnO crystalline structure. n-doping of graphene caused by charge transfer from ZnO to graphene has been detected by blue-shift of G-band of Raman spectra of the nanolaminates. ZnO photoluminescence intensity was found to be dependent on the number of graphene layers in G/ZnO nanolaminate. n-doping of graphene could be tailored by controlling the construction of the G/ZnO nanolaminates for variety of applications such as, for example, selective adsorption of the target molecules on graphene surface. Thus, G/ZnO nanolaminates may find applications in optical, bio-and chemical sensors.

An improvement of the sludge electrodewatering process is proposed: the anode flushing by filtrate recirculation. According to this technique, the mixture of filtrates obtained at cathode and anode sides, is used for continuous flushing of anode chamber of the filter press during electrodewatering. The anode flushing is aimed to eliminate essential problems of electrodewatering: ohmic heating, rise of electric energy consumption, electrodes corrosion, and filtrate contamination. This is attained by better control of the filtrate pH, the filter cake temperature and the dryness at anode side, where the physicochemical conditions are most aggressive. The efficiency of the proposed technique is evaluated at lab scale on drilling sludge electrodewatering with and without anode flushing. In experiments without anode flushing, increasing of electric current density caused strong increase of anode temperature, desiccation of the filter cake at anode side, rise of voltage and significant alkaline contamination of filtrate. The application of anode flushing allowed controlling the electric field strength and the temperature. Thus, the dewatering of the sludge has been extended at high electric field without damaging the filter equipment by drastic heating. Furthermore, it reduced the filtrate contamination by neutralization of the electrolysis products.

Graphene and multi-walled carbon nanotubes have attracted interest for a number of potential applications. One of the most actively pursued applications uses graphene and carbon nanotubes as a transparent conducting electrode in solar cells, displays or touch screens. In this work, in situ reduced graphene oxide/Poly (vinyl alcohol) and multi-walled carbon nanotubes/Sodium Dodecyl Sulfate/Poly (vinyl alcohol) composites were prepared by water dispersion and different reduction treatments. Comparative studies were conducted to explore the electrical and optical properties of nanocomposites based on graphene and multi-walled carbon nanotubes. A thermal reduction of graphene oxide was more effective, producing films with sheet resistances as low as 10 2 –10 3 Ω/square with 80% transmittance for 550 nm light. The percolation threshold of the thermally reduced graphene oxide composites (0.35 vol%) was much lower than that of the chemically reduced graphene oxide composites (0.57 vol%), and than that of the carbon nanotubes composites (0.47 vol%). The Seebeck coefficient of graphene oxide films changes from about 40 μV/K to −30 μV/K after an annealing of three hours at 200 °C. The optical absorption of the nanocomposites showed a high absorbance in near UV regions and the photoluminescence enhancement was achieved at 1 wt% graphene loading, while the carbon nanotubes based composite presents a significant emission at 0.7 wt% followed with a photoluminescence quenching at higher fraction of the nanofillers 1.6 wt% TRGO and 1 wt% MWCNTs.

International audience; Due to water scarcity, development of innovative processes for wastewater reuse has become a priority. Hence, hybrid processes coupling membrane separation with advanced oxidation processes could play a decisive role in the production of safe water. However, membrane fouling is still one of the main limitations to process widespread application. Thus, the present study investigates the impact of e-beam irradiation on the fouling ability of a secondary effluent (SE) filtered on MF and subsequently on RD membranes. For this, two electron beam radiation doses (1 and 5 kGy) were investigated. Results demonstrate that whatever the radiation dose investigated, no change in terms of TOC in SE was observed (prior to filtration). However, a strong decrease in 1JV254 and fluorescence signal was observed for organic matter (OM) exhibiting a MW ranging from 135 to 10 kDa. Pre -oxidation was found to efficiently optimize ME filtration permeate flux whereas no improvement could be observed regarding RD separation. Moreover it was demonstrated that ME efficiently removed the high MW compounds and was barely efficient in low MW compounds removal. Energetic balance based on experimental results demonstrates that 1 kGy was a sufficient dose to operate the hybrid e-beam irradiation and ME process.

International audience; A hybrid Mg-Al layered double hydroxide/graphene (LDH-GR) material nanostructure has been fabricated by employing the hydrothermal treatment at 140 degrees C for 10 h. Graphene oxide is simultaneously reduced to graphene during the hydrothermal treatment. The LDH and LDH-GR have high degree of crystallinity and assembled layer structure, which is attributed to electrostatic interaction mechanism. The obtained hybrid nanostructure materials can be used as flame retardant or conductor of electricity and heat due to the combination of different properties arising from graphene and LDH.

International audience; We present an introduction to the rapidly growing field of epitaxial graphene on silicon carbide, tracing its development from the original proof-of-concept experiments a decade ago to its present, highly evolved state. The potential of epitaxial graphene as a new electronic material is now being recognized. Whether the ultimate promise of graphene-based electronics will ever be realized remains an open question. Silicon electronics is based on single-crystal substrates that allow reliable patterning on the nanoscale, which is an absolute requirement for any new electronic material. That is why epitaxial graphene is based on single-crystal silicon carbide. We also present recent results on nanopatterned graphene produced by etching the silicon carbide before annealing so that the graphene structures are produced in their final shapes. This avoids post annealing patterning, which is known to greatly affect transport properties on the nanoscale. Creating such structured graphene is an elegant method for avoiding pervasive patterning problems.

The key limitation to the application of reverse osmosis (RO) desalination on inland brackish waters is concentrate disposal. Due to precipitation of sparingly soluble salts (CaCO3, CaSO4, BaSO4, SrSO4), RO membrane recovery cannot be increased further; therefore, other strategies must be investigated. Antiscalants are often added to RO feed water to help prevent precipitation and increase RO recovery, but in concentrate treatment, antiscalants may prevent precipitation of problematic constituents. A threestage process to treat brackish water RO concentrate was investigated; the stages include oxidation of antiscalants with ozone and hydrogen peroxide, precipitation at elevated pH, and solid/liquid separation. A model water concentrate was used to perform laboratory scale experiments for each treatment stage. Experimental results showed that the advanced oxidation process (AOP) of ozonation and hydrogen peroxide on phosphonate antiscalants allowed increased calcium precipitation as well as loss of the solubilizing effects of antiscalants as compared to precipitation without prior ozonation of the antiscalants. The AOP also removed the effect of antiscalant on precipitate particle size distribution and particle morphology. In some cases, the AOP also improved microfiltration performance for the solid/liquid separation stage. The concentrate treatment could increase overall recovery from 80% to 90% for non-ozonated, antiscalant-dosed concentrate and from 80% to 94% for ozonated, antiscalant-dosed concentrate. © 2010 Published by Elsevier B.V.

The postharvest hydrothermal treatment of date palm fruit was studied in order to enhance the quality and consumer acceptance of 'Deglet Nour' hard dates, because these dates are unfit for direct consumption. Hot water hydration was performed by soaking at 25, 45, and 65 degrees C and convective hot air drying at 35, 45, 60, 75, and 85 degrees C at various levels of air humidity. Numerous quality parametersi.e., texture, color, moisture and sugar contentswere investigated. Artificial maturation due to the softening of texture and the equilibration of sugars was achieved using the hydration pretreatment. A 6-h soaking at 45 degrees C could be the best option to obtain a product of highest quality, but the moisture content would exceed that required for safe storage. Drying and quality tests led to the selection of a pretreatment step of soaking at 30 degrees C for 8h, followed by drying at an intermediate temperature (60 degrees C) as the optimum condition to obtain a final product of high quality with the standard moisture content of 0.35kg/kg d.b.

To determine the technical and economic feasibility of cross-flow microfiltration on an industrial scale, the expected decline of permeation flux must be predicted taking into account the variability of juice's fouling potential. However, the main difficulty is finding representative parameters. Two semi-empirical models – gel polarisation and mechanistic – were used to fit experimental permeation flows using initial juice turbidity as surrogate for the volumetric concentration of particles in the feed juice. The experimental data of different banana, pineapple, and blackberry juices fitted well in both models. Although the mechanistic model more accurately estimated the permeation flux density, for practical application, the simpler polarisation model was preferred. Because this method uses a factor (i.e. turbidity) that reflects juice's fouling potential, it allows the optimisation of processing parameters and the prediction of permeation flux range in real industrial conditions.

Issu de : WasteEng 2008, Patras, GREECE, 3-5 June 2008; International audience; The number of waste disposal sites decreases and redundant poles, piling and lumber, which constitute a large volume of material, may not be accepted at the limited number of sites in the future. CCA contaminated wood contains around 1-5% of metal in form of arsenic pentoxide, hexavalent and trivalent chromium compounds and copper sulfate, which act as fungicides and insecticides throughout the life of the wood. While CCA treatment is gradually becoming a banned practice, approximately 4 million tonnes of CCA treated wood is generated in the EU per year, which is set to continue for many decades as the in-service wood is generated in end of its life. Recycling wood waste is important for the effective utilization of natural resources. The charcoal product resulting from CCA treated wood contains Cu, Cr and As. The metals appear as both agglomerates and diffused in the solid matrix. Moreover, during pyrolysis an agglomeration process takes place, which induces not only the growth of existing mineral agglomerates but also the formation of new agglomerates. The objective of the present work is the valorisation of CCA metals and charcoal from treated wood waste. The research aims at understanding and promoting experimentally, at different pyrolysis heating rates, the generation of charcoal with high specific surface area from pyrolysed treated wood waste.

cited By 8; International audience; In order to obtain new compounds with antitumoural action the N-(meta-acylaminobenzoyl)-α-acylaminobenzoyl)-α-aminoacids 4-9 were prepared. These compounds were subsequently converted into the corresponding Δ2-oxazolin-5-ones 10-15, which in turn were submitted to a ring opening reaction with di-(β-chloroethyl)amine to afford the peptide supported N-mustards 16-21, which showed low toxicity and cytostatic activity similar to that of sarcolisine against the Ehrlich ascite and Walker 253 carcinosarcoma. © 2007 by MDPI.

International audience; An electron-transfer chain reaction between 2-nitropropane anion and α-bromoketones derived from nitrobenzene and nitrothiophene was demonstrated by mechanistic study and a specific convenient synthetic protocol. Thus, 2-bromo-1-(5-nitrothiophen-2-yl)ethanone or 2-bromo-1-(4-nitrophenyl)ethanone were reacted with several cyclic nitronate anions to form α,β-unsaturated ketones via a SRN1 mechanism. This new method can be used to synthesize a wide variety of chalcone analogues.

The Bayer process is used for refining bauxite into smelting grade alumina (Al2O3), which is the precursor of aluminium. The process was developed and patented by Karl Josef Bayer 110 years ago and has become the cornerstone of the aluminium production industry worldwide. This study focuses on the characterization of the main liquor of the Bayer process, or Bayer liquor (BL) in terms of viscosity, composition and organic carbon distribution as a function of the molecular weight. It then shows that the purification of BL by nanofiltration helps to enhance the production of alumina. The organic carbon is well retained, which makes it possible to send a permeate back into the process, thus, increasing the whiteness and quality of the precipitated alumina crystals. Moreover, most of the other impurities are concentrated in the nanofiltration retentate. In view of the good results obtained on the Bayer liquor, this study is extended to the other effluent or solution of the Bayer process: nanofiltration can be used to retain more than 78% of most of the impurities present in these effluents.

International audience; Deep-frying, which consists of immersing a wet material in a large volume of hot oil, presents a process easily adaptable to dry rather than cook materials. A suitable material for drying is sewage sludge, which may be dried using recycled cooking oils (RCO) as frying oil. One advantage is that this prepares both materials for convenient disposal by incineration. This study examines fry-drying of municipal sewage sludge using recycled cooking oil. The transport processes occurring during fry-drying were monitored through sample weight, temperature, and image analysis. Due to the thicker and wetter samples than the common fried foods, high residual moisture is observed in the sludge when the boiling front has reached the geometric center of the sample, suggesting that the operation is heat transfer controlled only during the first half of the process followed by the addition of other mechanisms that allow complete drying of the sample. A series of mechanisms comprising four stages (i.e., initial heating accompanied by a surface boiling onset, film vapor regime, transitional nucleate boiling, and bound water removal) is proposed. In order to study the effect of the operating conditions on the fry-drying kinetics, different oil temperatures (from 120 to 180 degrees C), diameter (D = 15 to 25 mm), and initial moisture content of the sample (4.8 and 5.6 kg water(.)kg(-1) total dry solids) were investigated.

Une méthode d'optimisation multicritères est illustrée par un procédé de déshydratation-imprégnation par immersion (DII) dans des solutions aqueuses concentrées de saccharose suivi d'un séchage par air pour des morceaux de pomme. L'influence de l'historique du produit sur son comportement au cours du séchage est évalué experimentalement. Cinq paramètres du procédé sont pris en compte : température, concentration de la solution, durée de trempage, pour la DII puis, température et humidité relative pour le séchage par l'air. Les résultats montrent que la couche superficielle d'imprégnation formée de saccharose est un facteur limitant pour le transport de l'eau. Cet effet peut être réduit par un séchage à température élevée (80°C). D'autre part, l'humidité relative de l'air a peu d'influence sur le comportement des produits préalablement immergés. L'optimisation multicritères comporte six critères et montre que les produits stables et de qualité optimale peuvent être obtenus à des coûts énergétique intéressants et avec une durée de traitement courte (50 à 300 minutes)

International audience; Cell biologists have long aimed at quantitatively modeling cell function. Recently, the outstanding progress of high-throughput measurement methods and data processing tools has made this a realistic goal. The aim of this paper is twofold: First, to suggest that, while much progress has been done in modeling cell states and transitions, current accounts of environmental cues driving these transitions remain insufficient. There is a need to provide an integrated view of the biochemical, topographical and mechanical information processed by cells to take decisions. It might be rewarding in the near future to try to connect cell environmental cues to physiologically relevant outcomes rather than modeling relationships between these cues and internal signaling networks. The second aim of this paper is to review exogenous signals that are sensed by living cells and significantly influence fate decisions. Indeed, in addition to the composition of the surrounding medium, cells are highly sensitive to the properties of neighboring surfaces, including the spatial organization of anchored molecules and substrate mechanical and topographical properties. These properties should thus be included in models of cell behavior. It is also suggested that attempts at cell modeling could strongly benefit from two research lines: (i) trying to decipher the way cells encode the information they retrieve from environment analysis, and (ii) developing more standardized means of assessing the quality of proposed models, as was done in other research domains such as protein structure prediction.

International audience; SARS-CoV-2 remains infectious for several hours on surfaces. It can be inactivated by UV-C irradiation but optimal conditions for rapid inactivation, especially on non-plastic surfaces remains unclear. A SARS-CoV-2 inoculum was irradiated with a UV-C LED (265 nm) or a UV-C mercury lamp (254 nm). Infectivity titers (TCID50/mL) and inactivation rates were then quantified on plastic, steel, tissue, paper and cardboard surfaces. We demonstrated that efficient SARS-CoV-2 inactivation (> 99.999% on plastic and steel, ≥ 99.8% on tissue, paper and cardboard) can be achieved by both a UV-C mercury lamp and a UV-C LED after 30 s of irradiations at 3 cm, corresponding to UV-C doses of 92.85 and 44.7 mJ/cm2, respectively. Inactivation on a plastic surface was more efficient with the mercury UV-C lamp (p < 0.005). The mercury UV-C lamp could be more relevant than the LED in high-risk settings, such as medical care or research laboratories.

International audience; Nanoparticles of alloys represent a very interesting subject for fundamental research and, at the same time, a lot of useful applications in industrial catalysis, microelectronics, sensors and medicine. Their properties depend on the atomic and chemical structure which has been the subject of intensive researches. This paper presents some trends in theoretical predictions of the chemical ordering and surface segregation in Pt-based nanosized systems, especially transition and noble metals for which catalytic, magnetic and optical properties are well known. By associating two different metals, it is possible to improve selectivity in catalysis, or to increase magnetic anisotropy in magnetic systems, or to tune the surface plasmonic resonance in optical absorption, but the question is how the two species will mix or demix and how they will be distributed on the surface and in the core of the nanoparticle. This paper will give some general overviews concerning Pt–X, X=Co, Pd or Ag systems obtained from atomistic simulations. It will make a link between the chemical configuration adopted by the nanoalloys and the chemical characteristics of the system in terms of ordering tendency in bulk alloys and surface segregation in surface alloys.

International audience; This tutorial review paper consolidates the existing applications of the power watershed (PW) optimization framework in the context of image processing. In literature, it is known that PW framework when applied to some well-known graph-based image segmentation and filtering algorithms such as random walker, isoperimetric partitioning, ratio-cut clustering, multi-cut and shortest path filters yield faster yet consistent solutions. In this paper, the intuition behind the working of PW framework i.e. exploitation of contrast invariance on image data is explained. The intuitions are illustrated with toy images and experiments on simulated astronomical images. This article is primarily aimed at researchers working on image segmentation and filtering problems in application areas such as astronomy where images typically havea huge number of pixels. Classic graph-based cost minimization methods provide good results on images with small number of pixels but do not scale well for images with large number of pixels. The ideas from the article can be adapted to a large class of graph-based cost minimization methods to obtain scalable segmentation and filtering algorithms.

International audience; To advance an understanding of key electrochemical and photocatalytic processes that depend on the electronic structure of aqueous solutions, X-ray photoemission spectroscopy has become an invaluable tool, especially when practiced with liquid microjet setups. Determining vertical ionization energies referenced to the vacuum level, and binding energies referenced to the Fermi level, including the much-coveted reorganization energy of the oxidized species of a redox couple, requires that energy levels be properly defined. The present paper addresses specifically how the vacuum level "just outside the surface" can be known through the energy position of the rising edge of the secondary electrons, and how the Fermi level reference is uniquely determined via the introduction of a redox couple. Taking the case of the ferricyanide/ferrocyanide and ferric/ferrous couples, the paper also tackles issues related to the electrokinetic effects inherent to the production of a liquid jet in vacuum, which has become the standard water sample environment for photoemission experiments.

International audience; In catalytic industrial processes, coke deposition remains a major drawback for solid catalysts use as it causes catalyst deactivation. Extensive study of this phenomenon over the last decades has provided a better understanding of coke behavior in a great number of processes. Among them, catalytic pyrolysis of plastics, which has been identified as a promising process for waste revalorization, is given particular attention in this paper. Combined economic and environmental concerns rose the necessity to restore catalytic activity by recovering deactivated catalysts. Consequently, various regeneration processes have been investigated over the years and development of an efficientand sustainable process remains an industrial challenge. Coke removal can be achieved via several chemical processes, such as oxidation, gasification, and hydrogenation. This review focuses on oxidative treatments for catalyst regeneration, covering the current progress of oxidation treatments and presenting advantages and drawbacks for each method. Molecular oxidation with oxygen and ozone, as well as advanced oxidation processes with the formation of OH radicals, are detailed to provide a deep understanding of the mechanisms and kinetics involved (direct and indirect oxidation, reaction rates and selectivity, diffusion, and mass transfer). Finally, this paper summarizes all relevantanalytical techniques that can be used to characterize deactivated and regenerated solid catalysts: XRD, N2 adsorption-desorption, SEM, NH3-TPD, elemental analysis, IR. Analytical techniques are classified according to the type of information they provide, such as structural characteristics, elemental composition, or chemical properties. In function of the investigated property, this overall tool is useful and easy-to-use to determine the adequate analysis.

In the present paper, a half-wave plate (HWP) based on a birefringent metamaterial is numerically designed to operate in the visible range. The proposed structure consists of an array of double-pattern perpendicular rectangular aperture (RAA) engraved into opaque silver film deposited on a glass substrate. One of the apertures is glass filled. The operating principle of this plate is based on the excitation and the propagation of one guided mode inside each aperture but with different effective index. At the output side, a phase difference is obtained whose value mainly depends on the metal thickness. We have investigated the most simplest configurations using a homemade code based on the finite difference time domain method to design a half-plate with optimized efficiency resulting in transmission coefficient of more than $60\%$ together with a birefringence of $2.1$ at an operation wavelength of 737 nm. This kind of anisotropic metasurface promises a wide range of applications in integrated photonics., pages, 8 figures, Original paper

Radio-over-fiber (RoF) systems can be incorporated into a wavelength division multiplexing (WDM) and distributed antenna system (DAS) to vastly increase the data throughput. In this paper, a reconfigurable WDM system at millimeter (mm-wave) frequencies is theoretically proposed and experimentally demonstrated based on an optical frequency comb (OFC) and wavelength selective switch (WSS). The photonic carrier generation using OFC spectra is affected by chromatic dispersion which results in power fading and optical noise. Therefore, the tolerance of the mm-wave heterodyne carrier to fiber propagation is discussed and considered in the proposed architecture. Furthermore, this paper examines how the WSS can pre-compensate the fiber dispersion in terms of power fading on the beating carrier. Experimental measurements show that by variable adjustment of the amount of dispersion compensation applied, power fading of 15 dB can be mitigated and error vector magnitude (EVM) is reduced by 10 % . By utilizing the well-known periodic behavior between carrier power penalty and chromatic dispersion, the WSS can also overcome the deep power fading over long fiber lengths ( > 25 km).

International audience; This paper reports the synergetic effects of UV and visible light irradiation on the photocatalytic activity of well-defined nanostructures composed of TiO2 films and Au nanoparticles (NPs). New insights into electronic as well as chemical processes that drive water decomposition were obtained by varying the position of the NPs on top and at different depths inside the semiconductor film. This work highlights the synergetic effect of UV and visible light on the photocatalytic activity of all the Au-containing structures: hydrogen produced under UV + Vis light shows 100% enhancement compared to the net production obtained under either UV or visible light alone. The systems where Au NPs are embedded in TiO2 outperform the one where NPs are positioned on the surface, indicating that the water-splitting reaction occurs primarily on the TiO2 surface rather than on the metal. Photocurrent and photocatalytic activity measurements under UV (353–403 nm), visible (400–1100 nm), and UV + Vis (300–1100 nm) light revealed the synergetic contribution of UV and Vis light. Indeed, the plasmonic Au NPs create an intense oscillating electric field at the Au NPs/semiconductor interface (visible light contribution); this mechanism coupled with the Schottky barrier formation generates hot electrons resulting in a better photoexcited charge separation. In addition, contrary to what is generally assumed, charge injection by the plasmon from the metal into the semiconductor plays a marginal role in the hydrogen evolution reaction. Furthermore, this paper highlights the positive impact of the semiconductor crystallinity surrounding the metal particles to avoid the charge carrier recombination and the importance of a surface free of oxygen vacancies, whose presence can inhibit the water decomposition.

This paper reports the extension of vectorial complex ray model allowing to account, in the high-frequency limit, for the direction, polarization, curvature of wave front, amplitude, phase and scattered intensity of the light rays interacting with an infinite cylinder of arbitrary while smooth cross section. Based on the proposed method, a numerical study is performed on the scattering patterns of composite elliptical cylinders (CEC). The effects of shape deformation, refractive index and the direction of incident wave on the scattering patterns of the CEC whose cross sections approximate the shapes of realistic raindrops are investigated and quantitatively analyzed, which provides insight into how these factors affect the appearance of a natural rainbow. Being flexible and numerically efficient (a full scattering diagram is obtained in few seconds on a laptop computer), the method proposed in this paper is thought to have important applications in calculating and analyzing the scattering characteristics of light by cylindrical objects of cross sections ranging from simple to complex.

International audience; Van Dijk's Comment draws attention to the fact that the local pressure tensor, P(r), in an equilibrium system that is inhomogeneous is not uniquely defined at the nano-scale, as seen in Eq. (4) of our paper 1 , where the configurational term on the right involves an integral along a contour Cij connecting the centres of two molecules, i and j. The choice of this contour is arbitrary, resulting in the non-uniqueness of P. Physically, the non-uniqueness arises because the intermolecular forces are between two molecules located at ri and rj, i.e. they are non-local, whereas we wish to determine the pressure at a local point r, and there is no unique way to assign part of the non-local pair force to the local point r. To pursue the statistical mechanical approach to P one must first make an operational definition of the contour. All of this is well known in the statistical mechanical community. It is implicit in Kirkwood and Buff's 1949 paper 2 , and is discussed at some length in an Appendix of the seminal paper of Irving and Kirkwood (IK) 3. Irving and Kirkwood 3 , writing 70 years ago, stated the situation clearly: "all definitions must have this in common-that the stress 4 definition between a pair of molecules be concentrated near the line of centers. When averaging over a domain large compared with the range of the intermolecular forces, these differences are washed out, and the ambiguity remaining in the macroscopic stress tensor is of negligible order." Further discussion of these points were given later

The numerous combinations of cations and anions turn out possible to produce ionic liquids with fine-tuned properties once the correlation with the molecular structure is known. In this sense, computer simulations are useful tools to explain and even to predict properties of ionic liquids. However, quantum mechanical methods are usually restricted to either small clusters or short timescales, so that the use of parametrized force fields is needed for studying the bulk liquids. A method is proposed in this work to enable a comparison between quantum mechanical and both polarizable and non-polarizable force fields by means of the calculation of free energy surfaces for the translational motion of the anion around the cation in gas phase. This method was tested for imidazolium-based cations with 3 different anions, [BF4]-, [N(CN)2]-, and [NTf2]-. It was found better agreement with the DFT calculations when polarizability is introduced in the forcefield. In addition, the ion pair free energy surfaces reproduced the main structural patterns observed in the first coordination shell in molecular dynamics simulations of the bulk liquid, proving to be useful probes for the liquid phase structure that can be computed with higher level methods and the comparison with forcefields can indicate further improvements in their parametrization., author submitted version of the paper published in J. of Chemical Physics on 02 January 2020. 40 pages with 15 figures in main paper plus 19 pages with 20 figures as Supporting Information attached by the end of the file

International audience; Nowadays, the use of nanofluids as alternative to commonly-used industrial heat transfer fluids is a topic of increasing interest. Analysing the improved efficiency of heat transfer processes according to advanced nanomaterials and obtaining stable nanofluids is one of the most interesting challenges. This paper presents a study of nanofluids based on boron nitride nanotubes and using an aqueous solution of Triton X-100 (which acts as a surfactant) as the base fluid. UV-vis spectroscopy, particle size measurements (size between 150 and 170 nm) and potential (at about 25 mV) showed that stable nanofluids were obtained. Surface tension measurements were also performed. The surface tension of water was weakly affected by the presence of any amount of nanoparticles and was mainly governed by the presence of surfactant. The rheological properties of the fluids were also analysed, as were their isobaric specific heat and thermal conductivity values. A Newtonian behaviour was observed for the base fluid and the nanofluids, with no significant increase in viscosity. The isobaric specific heat increased by 8% and thermal conductivity by 10% compared with the base fluid. Thus, the results obtained are interesting because while thermal properties improved with nanoparticle content, rheological behaviour did not change. Consequently, the nanofluids studied in the current paper do not raise the pressure drop and pumping power significantly and may therefore be a good option for thermal system applications.

International audience; In this paper, we demonstrate a new method to obtain a low gap between the access waveguide and the racetrack cavity of a micro-resonator based on porous silica material and using standard photolithographic process. The photolithographic process is first carried out on porous silicon layers to obtain porous silicon ridge waveguides that constitutes the racetrack micro-resonator. Then the full oxidation of the micro-resonator is performed. Because of the volume expansion of silicon that occurs during its full oxidation, the gap is reduced. Lower gaps and then lower coupling distances can be obtained using a low cost photolithographic process compared to e-beam technology. This original method proposed in this paper allows to improve the miniaturization of such porous silica micro-resonators which is of great interest for integrated optical biosensor application.