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Dynamic reactor operations will gain interest with the increase of intermittent electricity from renewable sources. Periodic operation of catalytic reactors can also be used for kinetic studies with better parameter estimation than steady-state operation. This methodology is exemplified for the case of acetylene hydrogenation over Pd/α-Al2O3 using small amplitude flow oscillations. It allows the evaluation of several elementary kinetic parameters from one set of dynamic data for a reaction mechanism based on a single catalytic site. The optimized transient model is able to reproduce the time-evolution of the reactant and product molar fractions at the outlet of a fixed bed operated with modulations of different amplitudes and frequencies. It further shows that the acetylene conversion is controlled by two steps, the hydrogen adsorption step and the hydrogenation of the surface vinyl intermediate into adsorbed ethylene

This study aimed to investigate the key compounds involved in the aroma of French Syrah wines from the northern Rhone valley from two vintages characterized by distinct climatic conditions. The volatile composition of the wines was assessed through the determination of 76 molecules. After identifying the best matrix and best model for aroma reconstitution studies, omission tests were conducted using the Pivot© profile method. For both vintages, 35 molecules with odor activity values (OAVs) above 0.5 were identified. While remarkably high levels of 2-furfurylthiol (FFT) were reported in both wines, rotundone and 3-sulfanylhexanol (3SH) enabled the strongest discrimination between the two wines. Wine dearomatized using supercritical carbon dioxide (sCO2) was identified as the best matrix. The best models built using this matrix were composed of molecules with OAV > 5 and OAV > 10 highlighting that this dearomatization approach can be valuable to reconstitute the aroma of wine using a small number of molecules. For the cool vintage wine, the omission of rotundone and FFT had the greatest impact on the olfactive profile for non-anosmic and anosmic respondents to rotundone, respectively. 3SH, whose omission decreased the rating of the ‘fruity’ attribute, was identified as the main contributor to the aroma of Syrah wine produced in the warm vintage.

International audience; Identifying, designing, deploying and maintaining accurate collaborative networks of organizations (e.g. responders in a crisis situation) are key activities in nowadays ecosystems. However, there is a lack regarding formal approaches dedicated to characterize collaborative networks of organizations. Formal descriptions of collaborative situations, that could be used, transformed, computed and exploited would be of great benefit for the quality of such collaborative networks. This article presents a model‐based AI framework for describing collaborative situations and the associated formal metamodel dedicated to be instantiated to characterize collaborative situations in a very wide range of application domains. This metamodel (describing collaborative situation between organizations) is structured according to four complementary dimensions: the context (social, physical and geographical environment), the partners (the involved organizations, their capabilities resources and relations), the objectives (the aims of the network, the goals to be the achieved and the risks to avoid, etc.) and the behaviour (the collaborative processes to be implemented by the partners to achieve the objectives in the considered context). Besides, this metamodel can be extended for some precise application domains. This article focuses on this mechanism in the specific context of crisis management.

International audience; Software product lines (SPL) emulate the industrial production lines that are capable of generating large volumes of products through reuse schemes and mass production. A multi product line (MPL) aims to reuse of several SPL. Feature models are often used to manage the existing resources of SPLs and define valid products through notations and relationships such as mandatory, optional, and alternative features. The main contribution of this study is a method to manage the variability of multiple SPL and generate a new portfolio of products for Internet of Things (IoT). For this, the problem of developing a universal feature model (FM) for an MPL from merging the FMs of the individual SPLs with a Search-Based Software Engineering (SBSE) technique is addressed. In addition, the authors propose a multi-objective optimisation model to maximise the reusability and compatibility between features and minimise the development cost. The model facilitates the design of an MPL-feature model. Authors' empirical results show that the proposed model solved by genetic algorithms allows to configure a variety of software products and to determine the scope of the MPL.

Production of bio-succinic acid through microbial fermentation using agro-industrial waste has been observed extensively. Large scale production is now being considered since bio-succinic acid has broad range application in several industries including agricultural, food, chemical, metal, and pharmaceutical industry as a precursor, ion chelator, and or additive agent. One of promising microbes able to produce bio-succinic acid in large amount and recognized for industrial production is Actinobacillus succinogenes. However, several factors still need to be considered in order to optimize the fermentation performance. Therefore, this paper aims to review the progress of fermentation methods and discuss the fermentation strategy focused on the influences of different carbon sources, nitrogen sources, pH regulator, and fermentation configuration to the fermentation parameters including concentration, productivity and yield of bio-succinic acid. As a result, combinations of several fermentation strategies are needed to be performed to realize an efficient and effective bio-succinic acid industry. Keywords: Actinobacillus succinogenes, Agro-industrial waste, Bio-succinic acid, Fermentation strategies

International audience; In this comprehensive study, the interaction of human serum albumin (HSA) with poly(acrylic acid) (PAA) was explored using small angle X-ray scattering (SAXS) combined with chromatography. The results revealed the formation of a complex between HSA macromolecules and PAA chains but solely under some specific conditions of the ionic strength and pH of the medium. In fact, this binding was found to take place only at pH close to 5 and at low ionic strength (0.15 M). Otherwise, for a higher pH and a salt concentration of 0.75 M the HSA–PAA complex tends to dissociate completely showing the reversibility of the complexation. The assessment of the influence of the HSA/PAA molar ratio on the radius of gyration of the complex suggests that 4 HSA molecules could bind to each 100 kDa PAA chain. In addition, the Porod volume evaluation for the same range of the HSA/PAA ratio confirms this assumption. Finally, an all-atom SAXS modelling study using the BUNCH program was conducted to find a compatible model that fits the HSA–PAA complex scattering data. This model allows us to portray the HSA/PAA complex as a pearl-necklace assembly with 4 HSA molecules on the 100 kDa PAA chain.

International audience; The performance of a microbial electrolysis cell (MEC) supplied with domestic wastewater (dWW) is essentially limited by the kinetics of the anodic bioelectrochemical reactions and the low ionic conductivity of the electrolyte. A strategy to boost-up the anodic bioelectrochemical kinetics is to use three-dimensional (3D) microbial anodes that offer a high total anodic surface area and volume density of electroactive biofilm. In this work, a 3D multiphysics model was designed to simulate the current generation and resulting hydrogen production in double and triple-compartment MECs fed continuously with dWW. Simulations indicated that optimised 3D microbial anode geometries could simultaneously increase current and chemical oxygen demand (COD) removal by 86% compared to a 2D planar graphite electrode. At a constant CEM voltage, the current produced increased with the thickness of the 3D microbial anode up to a limiting thickness of 20 mm. Beyond this value, the current was stagnant due to the predominant ohmic drop. Current generation and COD removal could be further increased by designing 3D anode geometrical arrangements that force the dWWs to flow through the porosity of the 3D microbial anode. A gain of 20% was calculated by substituting a monolithic 3D graphite anode with a 3D anode of the same thickness (20 mm) but constructed of plates stacked on top of each other and spaced 2.5 mm apart. Finally, hydrogen production performance was additionally optimised by a further + 20% by switching from a two-compartment MEC design (anode-cathode) to a three-compartment MEC design (cathode-anode-cathode).

International audience; Yeast hulls can be used to adsorb undesirable compounds such as volatile phenols that may be present in wine. To understand this adsorption process, the properties of the cell walls and their chemical composition need to be better understood. A study was conducted using four different yeast fractions of either autolysed or high-pressure homogeniser (HPH)-crushed yeast biomasses of Saccharomyces cerevisiae and Brettanomyces bruxellensis. Near-infrared spectroscopy (FT-NIR) coupled with X-ray photoelectron spectroscopy (XPS) was used and analysed by principal component analysis (PCA). The FT-NIR spectral region of Saccharomyces and Brettanomyces statistically analysed by PCA showed a clear discrimination accounting for 76% of the variation in the data for PC1; moreover, yeast hulls prepared from the same strain and subjected to two different treatments were also separated. These methods classify yeast cell hulls (YCH) according to strain, composition and treatment applied. Our results indicate that yeast hulls obtained by autolysis are less rich in proteins than those resulting from HPH treatment due to the high pressure that releases more proteins and exposes them on the surface of the cell wall. The composition of YCH at the extreme surface is similar to that found deeper in the wall.

In this work we study the heat transport in inhomogeneous bubbly flow. The experiments were performed in a rectangular bubble column heated from one side wall and cooled from the other, with millimetric bubbles introduced through one half of the injection section (close to the hot wall or close to the cold wall). We characterise the global heat transport while varying two parameters: the gas volume fraction $\alpha = 0.4\% - 5.1 \%$, and the Rayleigh number $Ra_H=4\times10^9-2.2\times10^{10}$. As captured by imaging and characterised using Laser Doppler Anemometry (LDA), different flow regimes occur with increasing gas flow rates. In the generated inhomogeneous bubbly flow there are three main contributions to the mixing: (\textit{i}) transport by the buoyancy driven recirculation, (\textit{ii}) bubble induced turbulence (BIT) and (\textit{iii}) shear-induced turbulence (SIT). The strength of these contributions and their interplay depends on the gas volume fraction which is reflected in the measured heat transport enhancement. We compare our results with the findings for heat transport in homogeneous bubbly flow from Gvozdi{\'c} \emph{et al.} (2018). We find that for the lower gas volume fractions ($\alpha4\%$, when the contribution of SIT becomes stronger, but so does the competition between all three contributions, the homogeneous injection is more efficient.

International audience; The separation of ternary nonideal systems with multi‐azeotrope is very important because they are often found in the waste of chemical and pharmaceutical industries, which is much more difficult due to the formation of multi‐azeotrope and distillation boundary. We propose a systematic procedure for design and control of a triple‐column pressure‐swing distillation for separating ternary systems with three binary minimum azeotropes. This procedure involves thermodynamic insights, a two‐step optimization method, and effective control strategy. The separation of tetrahydrofuran (THF)/ethanol/water is used to illustrate the capability of the proposed procedure. It is found that the pressure limits in columns can be determined through the analysis of residue curve maps, distillation boundary, and isovolatility curves. The optimal triple‐column pressure‐swing distillation is generated with the minimum total annual cost (TAC) of $2.181 × 106 in sequence A. The operating conditions are well controlled approaching their desired specifications in an acceptable time when disturbances occur.

A fluidized bed of Geldart-A particles is promoted as heat transfer fluid in the tubular solar receivers of solar towers. A pressure-driven upward particle flow affects the hydrodynamic flow structure and properties of the fluidized bed. Experiments involved a tube of 0.05 m internal diameter but of very high height/diameter ratio (>120), representative of the future solar receiver and of numerous chemical reactors. Solid circulation fluxes and aeration velocities were varied. Configurations of a bare tube and a tube with bubble rupture promoters were compared. In the bare tube, freely bubbling is transformed into axi-symmetric slugging at a bed level of ~1 m. With bubble rupture promoters, freely bubbling prevails to about a bed level of 3 m, and a turbulent fluidization mode develops higher up the tube (a more chaotic two-phase system with elongated and unstable “gas voids” and “dense solid clusters”), without axi-symmetric slugging detected. Experimental results for both tube configurations were assessed and compared with CFD predictions by the Euler n-fluid code, NEPTUNE_CFD. A good agreement of bed properties was obtained for slug/void frequencies and solids volume fraction in both tube configurations. BRPs moreover enhance the bubble through flow of the fluidizing gas, thus limiting the visible bubble flow rate and bubble sizes while increasing the gas/particle contact, and hence important in designing multi-tube chemical reactors. Whereas slugging limits the heat transfer from the tube wall to the suspension at ~200 W/m2K, the presence of BRPs maintains a heat transfer coefficient in excess of 600 W/m2K.

International audience; Climate Change and its effects in water scarcity has become an important challenge for cities with water management problems. These problems require an integral planning of the city, which can be supported by optimization. The main goal of the research is to provide a regional optimization model for water networks, including new treatment options. The model is formulated as a multi-objective mixed-integer programming problem, focused on environmental and economic impact of the network, minimizing water extracted from natural sources and total cost. The formulation is developed with the goal-programming methodology. The model covers a complete existing city-scale water network, including 4 different options of water reuse within the city: drinking water, fresh water, irrigation, and discharge in natural courses. The case study is Santiago, capital of Chile, which is the political, economic, and institutional center of Chile. If both objective functions have equal importance to configure the solution, the following ideas characterize the optimal water network: (i) it is more environmentally and economically convenient to reuse water within the network rather than recycling water to the natural source; (ii) the reuse of water is preferred in the form of irrigation and drinking qualities rather than industrial qualities to reduce transport costs, and (iii) the modification of the current treatment plants is preferred, because of the high cost of installation of new plants. An environmental and cost-effective solution for Santiago, Chile, can reduce the source water extraction in 35.7%. The model can be implemented in other contexts, providing orientations to decision-makers so as to plan city-scale water networks with simultaneous environmental and economic considerations.

International audience; The in situ analysis of industrial processes, mostly conducted in opaque equipment is difficult. Whereas previously the positron emission technique was successfully applied to study the flow and mixing in gas-solid and liquid-solid systems using radio-active tracer particles, research on imaging a radio- active tracer gas is scarce. The present paper demonstrates the use of a fully three-dimensional (3D) Positron Emission Tomography (PET) in imaging the adsorption of 11CO2 tracer gas, while validating the measurement by conventional exit gas analysis. It will be demonstrated that PET can be used to measure the kinetics of high-pressure CO2 adsorption in situ, including the essential breakthrough and mass transfer zone characteristics. Such high-pressure operation is characteristic of pre-combustion CO2 capturing processes. It is expected that this work will foster further studies of gas-solid systems of adsorption, gas-solid catalysis, gas-solid hydrodynamics, and processes where the gas-solidinteraction is of primary importance.

International audience; The partial enzymatic hydrolysis of wheat gliadins constitutes an interesting tool to unravel their structural specificity. In this work, the structure and conformation of γ-gliadin were investigated through its limited chymotrypsic digestion. Using a combination of computational, biochemical and biophysical tools, we studied each of its N and C terminal domains. Our results reveal that γ-gliadin is a partially disordered protein with an unfolded N-terminal domain surprisingly resistant to chymotrypsin and a folded C-terminal domain. Using spectroscopic tools, we showed that structural transitions occured over the disordered N-terminal domain for decreasing ethanol/water ratios. Using SAXS measurements, low-resolution 3D structures of γ-gliadin were proposed. To relate the repeated motifs of the N-terminal domain of γ-gliadin to its structure, engineered peptide models PQQPY/F were also studied. Overall results demonstrated similarities between the N-terminal domain and its derived model peptides. Our findings support the use of these peptides as general templates for understanding the wheat protein assembly and dynamics.

International audience; The textile and clothing industry is the first manufacture sector in Tunisia in terms of employment and number of enterprises. It generates large volumes of textile dyeing wastewater (TDWW) containing high concentrations of saline, alkaline, and recalcitrant pollutants that could fuel tenacious and resilient electrochemically active microorganisms in bioanodes of bioelectrochemical systems. In this study, a designed hybrid bacterial halothermotolerant bioanode incorporating indigenous and exogenous bacteria from both hypersaline sediment of Chott El Djerid (HSCE) and TDWW is proposed for simultaneous treatment of real TDWW and anodic current generation under high salinity. For the proposed halothermotolerant bioanodes, electrical current production, chemical oxygen demand (COD) removal efficiency, and bacterial community dynamics were monitored. All the experiments of halothermotolerant bioanode formation have been conducted on 6 cm2 carbon felt electrodes polarized at −0.1 V/SCE and inoculated with 80% of TDWW and 20% of HSCE for 17 days at 45°C. A reproducible current production of about 12.5 ± 0.2 A/m2 and a total of 91 ± 3% of COD removal efficiency were experimentally validated. Metagenomic analysis demonstrated significant differences in bacterial diversity mainly at species level between anodic biofilms incorporating allochthonous and autochthonous bacteria and anodic biofilm containing only autochthonous bacteria as a control. Therefore, we concluded that these results provide for the first time a new noteworthy alternative for achieving treatment and recover energy, in the form of a high electric current, from real saline TDWW.

Highlights • The batch reactor dynamics is used to predict SARS-CoV-2 spreading. • The reactor model can phenomenologically explain the virus spreading. • The model predicts the peak (day and entity) and the infection extinction. • Initial Value Problem for ODE has been solved with an unknown initial condition. • Algorithm robustness and convergence have been tested., The pandemic infection of SARS-CoV-2 presents analogies with the behavior of chemical reactors. Susceptible population (A), active infected population (B), recovered cases (C) and deaths (D) can be assumed to be molecules of chemical compounds and their dynamics seem well aligned with those of composition and conversions in chemical syntheses. Thanks to these analogies, it is possible to generate pandemic predictive models based on chemical and physical considerations and regress their kinetic parameters, either globally or locally, to predict the peak time, entity and end of the infection with certain reliability. These predictions can strongly support the emergency plans decision making process. The model predictions have been validated with data from Chinese provinces that already underwent complete infection dynamics. For all the other countries, the evolution is re-regressed and re-predicted every day, updating a pandemic prediction database on Politecnico di Milano’s webpage based on the real-time available data.

International audience; In order to guarantee safe handling of a combustible liquid, such as biodiesel, it is important to be aware of its Flash Point (FP). Thus, the present study focused on FP experimental measurement and thermodynamic correlation of binary and ternary mixtures of saturated or unsaturated fatty acid ethyl esters (FAEEs) as surrogates for biodiesel. FP of different types of ethylic biodiesel in terms of feedstock (canola, corn, cotton and soy oils) were also measured and compared with the predicted values. Experiments were carried out in agreement with the standard closed cup procedure ASTM D6450. Liaw’s model was applied to FP prediction, with liquid phase non-ideality description accounted for by UNIFAC group contribution models (Original UNIFAC, UNIFAC-Dortmund and UNIFAC-Bessa with revised parameters for fats). FP prediction accounting for non-ideality proved to be accurate, with some difference between the UNIFAC type models and Root Mean Square Deviations (RMSD) varying from 0.27 K to 3.95 K for binary and ternary mixtures.

International audience; The calculation of the Osmotic Pressure and the Diffusion Coefficient, characterizing the cake layer developing during the Ultrafiltration (UF) of Bovine Serum Albumin (BSA), through a Multiscale Model based on Quantum Mechanics (QM) and Monte Carlo methods (MC) was the aim of this work. From the ab-initio results described in previous works, the distribution of the BSA surface charges was used. A home-made Metropolis MC algorithm, aimed at simulating the formation of BSA loose or concentrated layers during membrane operations, was also implemented. In such a MC algorithm, a DLVO energy calculation methodology of the adsorbed system was developed. Different MC simulations and Hypernetted Chain theory (HNC) calculations were performed so to determine both the Osmotic Pressure and the Diffusion Coefficient of BSA according to the Chun and Bowen approach, thus allowing a comparison between the calculated values of osmotic pressure and a set of experimental data taken from the literature. Such a comparison showed a good agreement between the simulated and the experimental results.

Responding rapidly to customer needs is one of the main targets of industrial organizations that want to survive in the current market competition. This objective can be attained through robust planning. Workforce productivity is considered one of the important entities in production planning. However, it has a dynamic nature, i.e. the productivity growths thanks to on-job training or learning phenomenon. Considering this fact in manufacturing planning enhances the robustness of the developed plans. The present paper presents a mathematical model for medium-range production planning that is used to find the optimal aggregate production plan. The model aims to optimize the total production costs while respecting most of the operational constraints and considering the process of organizational learning. The presented model is constructed relying on the real industrial practices; the outcome is a mixed-integer linear program. The model was validated and checked using real data collected from an Egyptian factory that produces electric motors for home appliances. The proposed mathematical model was optimally solved using “ILOG-CPLEX 12.6”. By comparing the results obtained versus that of the method adopted in the factory, a cost reduction of 6.3% is achieved for the presented data set. A set of managerial aspects are concluded after the model analysis. Moreover, the impact of using detailed learning rates on the production cost is discussed.

International audience; In this paper, five classical nonlinear state observers: extended Luenberger observer (ELO), extended Kalman filter (EKF), high-gain observer (HGO), sliding mode observer (SMO) and adaptive observer (AO), are applied to an intensified chemical heat exchanger/reactor (HEX reactor). In order to choose a suitable observer to develop a new fault diagnosis algorithm for this high nonlinear system, the behaviors of these observers are compared. The maximum overshoot and the settling time, which are the key features of the dynamic of the output estimation error system, are used as the criteria to compare the performances of the observers. Both cases with and without measurement noise are considered. It is concluded that the AO presents the fastest convergence speed and the minimum oscillation for the application to the HEX reactor. And the information provided by the AO will be further used for its fault diagnosis.

International audience; Among the strategies employed to protect metallic materials, coatings can be considered as one of the most successful and cost-effective alternatives to efficiently increase the service lifetime of metallic structures, particularly in industries that are continuously exposed to changing and hard weather conditions such as shipbuilding, automobile, aerospace, marine and oil & gas energy infrastructures. However, towards a more constraining legislation as REACH, the surface treatment & coating Industry is at the forefront in developing innovative and even more sustainable products. In the anticorrosion domain, Nature is a fruitful provider of new concepts for green solutions.Biomineralization is a widespread phenomenon that leads to the formation of different biological minerals and has been a large source of inspiration for a variety of fields, ranging from biotechnology, geotechnology, paleobiology to civil engineering and with relevant importance in biomedical research. Comparatively, in the research area of Anticorrosive Coatings, biomineralization has been an underdeveloped approach. Recently, some scientific publications in the field of corrosion and protection have mentioned the advantage of biogenic mineral precipitation on materials surface protection [1, 2]. Notwithstanding these observations, mostly performed in laboratory, the fact that the biomineralization film formed on metal surface can reduce corrosion has been insufficiently explored and should be considered as novel and eco-friendly start-point to produce anticorrosion solutions. Aluminium is currently the second most used metal in the world, providing advantages like low weight, maintenance costs savings, easy workability and recyclability. More specifically, the aluminium-magnesium alloy (Al-Mg) of the 5XXX series is commonly used in marine industry due to corrosion resistance. The main goal of this study is to prove the anticorrosive behaviour of naturally coating formed by biomineralization process on AA5083 alloy surface during estuarine exposure. Experimental work included accelerated salt spray test performed on AA 5083 samples with 2 and 3 years of immersion in Tejo estuary and without exposure. Morphological and chemical characterisation by SEM/EDS, surface and cross-section, were performed before and after the accelerated ageing test.[1] C. Cote, O. Rosas, R. Basseguy, “Geobacter sulfurreducens: An iron reducing bacterium that can protect carbon steel against corrosion?” Corrosion Science, 94, 2015.[2] Yuanyuan Shen et al, “Study of pitting corrosion inhibition effect on Al alloy in seawater by biomineralized film“, Bioelectrochemistry, 132, 2020.

International audience; Biofilm formation can strongly influence the composition of the surface oxide layer of metals and thus their electrochemical behaviour when immersed in solutions containing microorganisms. Actually, bacteria activity can locally change the interactions occurring at the interface between the solution and the material, modifying the stability of the material in that environment and its corrosion rate. Because of this, great differences can be encountered between abiotic and biotic conditions.This work deals with the characterization of two stainless steels immersed in a hypersaline solution containing bacteria inoculum, in order to assess the different composition and stability of the surface passive layers formed in this environment. Materials under study were AISI 304 and AISI 316 stainless steels. The electrolytic solution was a Starkey medium, with the addition of 45g/L NaCl and salt marsh sediments as inoculum (10 vol%). Samples of both materials were immersed in the solution for 15 days and electrochemical measurements were carried regularly. Cyclic voltammetry and Electrochemical Impedance Spectroscopy (EIS) were performed in order to assess the corrosion rate and the surface oxide layer stability. At the end of test, morphological characterizations were carried out using epifluorescence microscopy, SEM and EDS. XPS measurement were used in order to identify the different oxides formed on the sample surface during immersion in this hypersaline medium and correlate them to the results coming from electrochemical characterizations. A different electrochemical behaviour could be highlighted for the two stainless steels immersed in the hypersaline solution containing the salt marsh sediments. The surface oxide layer was more protective for AISI 316 samples than for AISI 304 ones, where the layer was less compact and continuous. In addition, when comparing biotic and abiotic (sterile) conditions, a lower corrosion rate was evaluated for samples immersed in the presence of microorganisms. This difference could be attributed to the microbial activity which, by consuming the oxygen in the solution, creates less aggressive anaerobic conditions for steel.

International audience; Expanded polytetrafluoroethylene (ePTFE) is one of the materials widely used in the biomedical field, yet its application is being limited by adverse reactions such as thrombosis when it comes in contact with blood. Thus, a simple and robust way to modify ePTFE to be biologically inert is sought after. Modification of ePTFE without high-energy pretreatment, such as immersion coating, has been of interest to researchers for its straightforward process and ease in scaling up. In this study, we utilized a two-step immersion coating to zwitterionize ePTFE membranes. The first coating consists of the co-deposition of polyethylenimine (PEI) and polydopamine (PDA) to produce amine groups in the surface of the ePTFE for further functionalization. These amine groups from PEI will be coupled with the epoxide group of the zwitterionic copolymer, poly(GMA-co-SBMA) (PGS), via a ring-opening reaction in the second coating. The coated ePTFE membranes were physically and chemically characterized to ensure that each step of the coating is successful. The membranes were also tested for their thrombogenicity via quantification of the blood cells attached to it during contact with biological solutions. The coated membranes exhibited around 90% reduction in attachment with respect to the uncoated ePTFE for both Gram-positive and Gram-negative strains of bacteria (Staphylococcus aureus and Escherichia coli). The coating was also able to resist blood cell attachment from human whole blood by 81.57% and resist red blood cell attachment from red blood cell concentrate by 93.4%. These ePTFE membranes, which are coated by a simple immersion coating, show significant enhancement of the biocompatibility of the membranes, which shows promise for future use in biological devices.

International audience; Oils spilled into surface water require effective and timelytreatment. In this paper, we report on a low-molecular-weight gelator that can form gels in organic and aqueous phases. The aqueous gel was observed to absorb oils, which is proposed as a new class of materials for remediatingoil spilled into surface water. The gels and the low molecular-weight gelator have both fundamental and applied significance. Fundamentally, identifying the mechanisms that govern the formation of these gels and their resultant mechanical properties is of interest. Subsequently, these fundamental insights aid in the optimization of these gels for addressing spilled oil. First, we briefly compare the organic and aqueous gels qualitatively before focusing on the aqueous gel. Second, we demonstrate the ability of the aqueous gel to wick oils through experiments in a Hele-Shaw cell and compare our results to the Washburn equation for porous media. The Washburn equation is not entirely adequate in describing our results due to the change in volume of the porous media during the wicking process. Finally, we investigate mechanisms proposed to govern the formation of low-molecular-weight gels in the literature through rheological shear measurements during gel formation. Our experiments suggest that the proposed mechanisms are applicable to our aqueous gels, growing as anisotropic crystal networks with fractal dimensions between one and two dimensions from temporally sporadic nucleation sites.

A10K (A=alanine, K=lysine) model peptides self‐assemble into ribbon‐like β‐sheet aggregates. Here, we report an X‐ray diffraction investigation on a flow‐aligned dispersion of these self‐assembly structures. The two‐dimensional wide‐angle X‐ray scattering pattern suggests that peptide pack in a two‐dimensional oblique lattice, essentially identical to the crystalline packing of polyalanine, An (for n>4). One side of the oblique unit cell, corresponding to the anti‐parallel β‐sheet, is oriented along the ribbon's axis. Together with recently published small angle X‐ray scattering data of the same system, this work thus yields a detailed description of the self‐assembled ribbon aggregates, down to the molecular length scale. Notably, our results highlight the importance of the crystalline peptide packing within its self‐assembly aggregates, which is often neglected., X‐ray diffraction of flow aligned A10K ribbon aggregates (alignment indi‐ cated by birefringence) results in an oriented diffraction pattern. Based on this pattern a 2D oblique lattice as the internal crystalline structure is proposed for the aggregates.

International audience; Saccharothrix algeriensis NRRL B-24137 is an actinobacterium isolated from Algerian Saharan soil. This strain has the ability to produce several dithiolopyrrolone antibiotic derivatives depending on the precursors added to the culture medium. This group of antibiotics is known for their potent antimicrobial and anticancer activities. Holomycin is a member of the dithiolopyrrolone group of antibiotics, and has already been isolated from several species of actinobacteria belonging to the genus Streptomyces and also from some Gram-negative bacteria. In this study, holomycin was produced for the first time in the culture broth of a non-Streptomyces actinobacteria. This antibiotic was induced by adding 5 mM of L-cystine as precursor to the semi-synthetic fermentation broth of Sa. algeriensis NRRL B-24137 and then fully identified after HPLC purification. The minimum inhibitory concentrations (MIC) of holomycin were determined against several pathogenic microorganisms, including Escherichia coli ATCC 10536 Klebsiella pneumoniae CIP 82.91, Listeria monocytogenes CIP 82110, Staphylococcus aureus CIP 7625, Aspergillus carbonarius M333, Fusarium culmorum FC1, Candida albicans IPA 200. This antibiotic showed a broad-spectrum antimicrobial activity, inhibiting a variety of Gram-positive and Gram-negative bacteria, and micro-fungi.

International audience; Brassica tournefortii is an annual herbaceous plant, native to the North Africa and Middle East. It is considered as an excellent medicinal plant due to its richness by antioxidant like isothiocyanates and polyphenols. The present study is the first phytochemical investigation on Brassica tournefortii organs (leaves, stems, and roots) in terms of nutraceutical, chemical composition, and bioactivity. Brassica tournefortii leaves exhibited the highest values of nutraceutical contents. Interestingly, gas chromatograph‐y‐mass spectrometry (GC‐MS) analysis enabled to identify three new isothiocyanates: iberverin nitrile and iberin detected only in roots, and iberin nitrile detected in all organs. HPLC chromatograms displayed different profiles depending on organic solvent and extracted organ. Icariin and 5,7‐dihydroxy 4‐propylcoumarin showed the highest concentrations with 2.3 and 1.3 mg/g of dr among other molecules identified by high performance liquid chromatography (HPLC). Some phenolic compounds were identified in more than one organ extracts such as phenoxodiol and 4‐hydroxy‐3‐propylbenzoic acid methyl ester. Brassica tournefortii extracts showed a moderate total phenolic contents and anti‐15‐LOX activity, while they exhibited a good anti‐α‐glucosidase activity ranging from 40% to 60%. Furthermore, leaves‐MeOH and root‐dichloromethane (DCM) extracts induced the highest cytotoxicity against MCF‐7 cell lines, while roots‐cyclohexane (CYHA) extract highlighted the highest inhibition activity against, both, HCT‐116 and OVCAR cell lines.

International audience; Hydrogen permeation through nickel dense membrane applied to Sodium cooled Fast Reactors has been studied theoretically and experimentally. In order to investigate the coupling of nickel membrane with external gas and sodium flows, an analytical model based on mass transfer resistances is developed. A sensitivity analysis showed that, for enough thick membranes and high sodium velocities, the nickel resistance has the most important effect. A permeator prototype constituted of four Ni201 tubular membranes, has been designed: experimental tests at pilot-scale are carried out at different temperatures, gas pressures and flowrates, both in gas-vacuum and gas-sodium configuration. Results for permeation against vacuum demonstrate that hydrogen diffusion within the membrane is the limiting step, in accordance with previous literature results obtained for pure nickel permeation experiments.

International audience; A fully Eulerian approach to predict fluids-membrane behaviours is presented in this paper. Based on the numerical model proposed by Ii et al. (2012), we present a sharp methodology to account for the jump conditions due to hyperelastic membranes. The membrane is considered infinitely thin and is represented by the level set method. Its deformations are obtained from the transport of the components of the left Cauchy-Green tensor throughout time. Considering the linear or a hyperelastic material law, the surface stress tensor is computed and gives the force exerted by the membrane on the surrounding fluids. The membrane force is taken into account in the Navier-Stokes equations as jump conditions on the pressure and on the velocity derivatives by imposing suitable singular source terms in cells crossed by the interface. To prevent stability issues, an extension algorithm has been developed to remove the normal derivatives of the scalar fields specific to the membrane. In particular, a subcell resolution at the interface of the extrapolated variable is proposed for increasing the accuracy of the extension algorithm. These improvements are validated by comparing our numerical results with benchmarks from the literature. Moreover, a new benchmark is proposed for fluids with both different viscosities and different densities to target applications where a gas and a liquid phase are separated by a membrane.

International audience; Glycerol is a by-product produced from biodiesel, fatty acid, soap and bioethanol industries. Today, the value of glycerol is decreasing in the global market due to glycerol surplus, which primarily resulted from the speedy expansion of biodiesel producers around the world. Numerous studies have proposed ways of managing and treating glycerol, as well as converting it into value-added compounds. The electrochemical conversion method is preferred for this transformation due to its simplicity and hence, it is discussed in detail. Additionally, the factors that could affect the process mechanisms and products distribution in the electrochemical process, including electrodes materials, pH of electrolyte, applied potential, current density, temperature and additives are also thoroughly explained. Value-added compounds that can be produced from the electrochemical conversion of glycerol include glyceraldehyde, dihydroxyacetone, glycolic acid, glyceric acid, lactic acid, 1,2-propanediol, 1,3-propanediol, tartronic acid and mesoxalic acid. These compounds are found to have broad applications in cosmetics, pharmaceutical, food and polymer industries are also described. This review will be devoted to a comprehensive overview of the current scenario in the glycerol electrochemical conversion, the factors affecting the mechanism pathways, reaction rates, product selectivity and yield. Possible outcomes obtained from the process and their benefits to the industries are discussed. The utilization of solid acid catalysts as additives for future studies is also suggested.

Glycerol electrooxidation has attracted immense attention due to the economic advantage it could add to biodiesel production. One of the significant challenges for the industrial development of glycerol electrooxidation process is the search for a suitable electrocatalyst that is sustainable, cost effective, and tolerant to carbonaceous species, results in high performance, and is capable of replacing the conventional Pt/C catalyst. We review suitable, sustainable, and inexpensive alternative electrocatalysts with enhanced activity, selectivity, and durability, ensuring the economic viability of the glycerol electrooxidation process. The alternatives discussed here include Pd-based, Au-based, Ni-based, and Ag-based catalysts, as well as the combination of two or three of these metals. Also discussed here are the prospective materials that are yet to be explored for glycerol oxidation but are reported to be bifunctional (being capable of both anodic and cathodic reaction). These include heteroatom-doped metal-free electrocatalysts, which are carbon materials doped with one or two heteroatoms (N, B, S, P, F, I, Br, Cl), and heteroatom-doped nonprecious transition metals. Rational design of these materials can produce electrocatalysts with activity comparable to that of Pt/C catalysts. The takeaway from this review is that it provides an insight into further study and engineering applications on the efficient and cost-effective conversion of glycerol to value-added chemicals.

The cleaning phase is seldom included in the eco-design of food processes, since few cleaning kinetics models exist. The goal of this study was to investigate benefits of including a cleaning kinetics model, which considers three major operating parameters of cleaning (concentration, temperature and flow rate), in the eco-design of a food process. To this end, we developed an eco-design approach for a dairy evaporator process that includes both production and cleaning phases. A cleaning kinetics model was selected to predict cleaning duration as a function of the operating parameters of cleaning. Cleaning duration also depends on the fouling surface density, which depends on the duration of the production phase. Fouling surface density was predicted using three hypothetical fouling kinetics laws. After optimization, environmental and economic improvements were observed in process performance. The evaporation process is optimized at a high cleaning temperature (95 °C), a flow-rate similar to that used during the production phase and a low caustic soda concentration (

International audience; The Sahara, one of the most extreme environments on Earth, constitutes an unexplored source of alkalitolerant actinobacteria. In this work, we studied the diversity of alkalitolerant actinobacteria in various soils collected from different regions of the Algerian Sahara. A total of 29 alkalitolerant actinobacterial strains were isolated by using a complex agar medium. The diversity of these actinobacteria was evaluated using a polyphasic approach, which included morphological, chemotaxonomic, physiological (numerical taxonomy) and 16S rRNA gene analyses. The isolates which were assigned to the genus Nocardiopsis, shared relatively low 16S rRNA gene sequences similarities compared to closely related species suggesting that they belonged to putatively new species. All of the strains were tested for antibiotic activity against a broad range of microorganisms and screened for genes encoding polyketide synthases and non-ribosomal peptide synthetases and found to have the potential to produce secondary metabolites. Consequently, the study supports the view that extreme environments contain many novel actinobacteria, which represent an unexplored source for the discovery of biologically active compounds.

International audience; Objectives : Salmonella enterica subsp. enterica serovar Kentucky has been associated with the worldwide ciprofloxacin-resistant (CIPR) Salmonella Kentucky sequence type 198 (ST198) epidemic clone, mostly recovered from poultry farms and products. The aim of this study was to examine whether this expanding clone exists in the Lebanese broiler chain.Methods : Eight CIPR and extended-spectrum cephalosporin-resistant Salmonella Kentucky isolates previously recovered from Lebanese broilers were genetically characterised by whole-genome sequencing.Results : Seven of the eight isolates belonged to ST198 and were phylogenetically closely related. They all harboured mutations in the chromosomal quinolone resistance genesgyrA and parC with double and single substitutions, respectively. The blaTEM-1B and blaCMY-2 genes were both detected in six isolates. Insertion sequence ISEcp1 was located upstream of blaCMY-2, harboured by IncI1 plasmids in four strains. An IS10 transposition coupled to homologous recombination at transposition sites mediated CMY-2 plasmid integration into the chromosome of one strain. Resistance genes to aminoglycosides [aadA7 and aac(3)-Id], tetracyclines [tet(A)] and sulfonamides (sul1) were detected in five strains, among which four were positive for the presence of Salmonella genomic island 1 (SGI1) variant SGI1-K. All studied isolates harboured a variety of Salmonella pathogenicity islands (SPIs) as well as common regulatory and virulence genes.Conclusion : Here we report for the first time in Lebanon the detection and dissemination of the emerging highly drug-resistantSalmonella Kentucky ST198. Our findings shed new light on this clone as a potential public-health threat.

International audience; The crystal growth and morphology of cyclopentane (CP) hydrates at a quiescent water/oil interface in the presence of 10 different surfactants were observed under a microscope. In most cases, the oil was CP, but for some of the observations a 50/50 vol % mixture of CP and n-octane (n-C8) (or n-dodecane (n-C12)) was used instead. For some of the surfactants, gas hydrates formed from a methane (CH4)/propane (C3H8) gas mixture at a quiescent water/n-C8 interface were also observed. The capacity of the surfactants to prevent the hydrate particles from agglomerating was assessed by measuring torque on oil-dominated systems (70 vol %) in a stirred autoclave at subcoolings of 6 and 10 °C for the CP hydrates and CH4/C3H8 hydrates, respectively. The oil phases were the same as those used in the morphology study. In the case of CP hydrates, the agglomeration state of the system was directly observed by opening the autoclave at the end of the hydrate formation. The size of the CP hydrate particles was measured, and their wettability was determined. The effect of the presence of salt (NaCl) on the crystal morphology and AA performance was also studied for some systems. All the surfactants that induced the formation of hydrate crystals that rapidly agglomerated at the water/CP interface showed poor AA performance. Whenever the surfactants induced the formation of individual oil-wettable crystals, their AA performance was good. If the individual crystals formed were water-wettable, two main behaviors were observed: (1) when the surfactant induced a very low water/CP interfacial tension (1 mN/m), it exhibited poor AA performance. These trends in the AA performance of the surfactants were observed on both hydrate systems (CP hydrates and CH4/C3H8 hydrates). From the experimental results obtained in this work, we can infer that the microscopic observation of the morphology and growth pattern of CP hydrate crystals formed at a quiescent water/CP interface might be a simple way to rapidly assess if a surface-active molecule has an antiagglomeration effect on sII gas hydrates.

International audience; This article proposes a novel approach that uses a mathematical model optimized by Genetic Algorithms harmonized with the Russian theory of problem solving and invention (TRIZ) to design an export packing of Persian Lime. The mathematical model (with functional elements of non-spatial type) optimizes the spaces of the Persian Lime Packing, maximizes the Resistance to Vertical Compression and minimizes the Amount of Material Used, according to the operation restrictions of the packing during the transport of the merchandise. This approach is developed in four phases: the identification of the solution space; the optimization of the conceptual design; the application of TRIZ; and the generation of the final proposal solution. The results show the proposed packing (with 28% less cardboard) supports at least the same vertical load with respect to the nearest competitor packing. However, with the same number of packings per pallet and pallets per container, the space used by the packing assembled and deployed in the container is greater by 10% and 38% respectively. Besides, TRIZ includes innovative non-spatial elements such as the airflow and the friction of the product inside the packing. The contribution of this approach can be replicable for the packing design of other horticultural products of the agri-food chain

Malgre leur fort developpement en assainissement domestique urbain, les bioreacteurs a membranes (BaM) pâtissent de phenomenes de colmatage, induisant des couts energetiques et de maintenance importants. L’aeration sequencee des membranes par des grosses bulles est l’une des strategies pour limiter le colmatage ; son impact a fait l’objet de plusieurs etudes mais reste globalement mal compris, notamment du fait de la complexite de ces systemes, multiphasiques et opaques. L’hydrodynamique des reacteurs reste mal caracterisee en presence de boues. Pour apporter des elements de comprehension aux mecanismes de limitation du colmatage par injection d’air, un pilote de filtration membranaire semi-industriel (2 m3, 3 sous modules fibres creuses Puron®) a ete concu, dimensionne et installe sur l’unite de traitement des jus (TDJ) de la station d’epuration Seine Aval (SIAAP), afin d’etre alimente en boues biologiques dans des conditions reelles de fonctionnement. Le suivi des parametres operatoires du pilote et de ses performances de filtration sur une periode de 5 mois avait un double objectif : (i) mieux caracteriser la dispersion du gaz pour differentes conditions de fonctionnement (parametres de l’aeration, concentration en boues de l’alimentation), (ii) hierarchiser les facteurs qui limitent le colmatage des membranes. Il s’agit in fine de proposer des strategies d’aeration adaptees et efficaces pour limiter le colmatage. Afin de caracteriser la dispersion du gaz dans le reacteur, une methodologie innovante basee sur la tomographie de resistivite electrique (ERT) a ete adaptee au pilote. Les conditions d’utilisation de l’ERT (nombre d’electrodes de mesure, sequence de quadripoles) ont ete selectionnees a travers une etude numerique, de meme que les parametres d’inversion necessaires pour reconstituer la cartographie des resistivites a partir des mesures experimentales. Cette etude numerique poussee, realisee sous COMSOL, a permis de conclure a l’interet de la methode pour representer la distribution des phases dans la geometrie consideree. L’ERT a donc ete appliquee au pilote alimente en boues, pour differentes conditions d’aeration. Le jeu de donnees de filtration a par ailleurs ete analyse par logique floue, a l’aide du logiciel FisPro. Les arbres de decision obtenus, en analysant les resultats de maniere globale et en les regroupant par conditions operatoires similaires, ont mis en evidence l’impact preponderant des variables suivantes sur la derive de permeabilite observee (comprise entre - 9 et 2 LMH/bar) : la difference de DCO entre le surnageant des boues et le permeat (DDCO) traduisant une phase colloidale complexe, et la concentration en matieres en suspension (MES), ayant toutes deux un impact negatif sur les performances de filtration. Une augmentation du debit d’air conduirait a une limitation de la derive de permeabilite, sauf lorsque la variable DCO est elevee (> a 500 mg/L), cette hypothese restant cependant a verifier sur une base de donnees plus consequente. Le modele ainsi obtenu par logique floue permet de mieux simuler les evolutions de permeabilite que les modeles obtenus par regression lineaire multivariee (erreurs de 0,61 et de 0,70 respectivement), et ce malgre une incertitude relative importante sur la mesure de permeabilite (jusqu’a 16 %). Ces resultats sont coherents avec la dispersion du gaz observee par ERT : son homogeneite depend de la concentration en MES et du debit d’air injecte. A forte concentration en MES (6 – 10 g/L), des zones preferentielles de passage des bulles ont ete observees, en particulier a faible debit d’air, expliquant ainsi un colmatage plus important. L’utilisation nouvelle dans ce contexte de ces techniques, ERT et logique floue, donne des resultats qui confortent l’interet d’adapter l’aeration (debit, sequencage) aux caracteristiques des boues notamment leurs concentrations, et qui permettent d’envisager des strategies de controle de ces parametres

To develop non-metallic electrocatalyst for glycerol electrooxidation, simultaneous co-doping of nitrogen and fluorine into activated carbon black (ACB) composite was explored to investigate the physical and electrochemical characteristics. The ACB was prepared by mixing activated carbon and carbon black. The N and F were incorporated using aniline and polytetrafluoroethylene as the precursors. The morphologies of the prepared samples were analyzed and the electrochemical behavior, as well as the electrocatalytic performance, was investigated in acid and alkaline environment. Porosity analysis shows that 20% N and F co-doped ACB (ACB-N2F2) reduced the surface area (491.64 m2 g−1) and increased the electroactive surface area, which could contribute to faster mass transport and electron transfer process to enhance the catalytic activity the electrode. The doping defect also reduced the charge transfer resistance, which could increase the spin densities and maximize charge re-distribution to generate more electroactive surface. The electrodes N-doped ACB (ACB-N2) and ACB-N2F2 exhibited a remarkable electrocatalytic activity in alkaline medium, while only 30% N and F co-doped ACB electrode are suitable in acidic medium. Moreover, the catalyst displayed remarkable long-term stability/durability in alkaline environment.

International audience; In Algeria, little information is available on the population structure of Aspergillus section Flavi in raw materials and resultant animal feeds. A total of 172 isolates belonging to Aspergillus section Flavi were recovered from 57 animal feeds and identified on the basis of macro and micro‐morphological characters, mycotoxin production and genetic relatedness. For the molecular analysis, sequencing of the calmodulin gene (CaM) and the internal transcribed spacer (ITS) regions were performed for representative isolates. Four distinct morphotypes were distinguished: Aspergillus flavus (78.5%), Aspergillus tamarii (19.2%), Aspergillus parasiticus (1.7%), and Aspergillus alliaceus (0.6%). All A. flavus isolates were of the L type and no correlation between sclerotia production and aflatoxigenicity was observed. Our results showed that 68% of the A. flavus strains produced aflatoxins B (AFB), and 72.7% were cyclopiazonic acid (CPA) producers. The three isolates of A. parasiticus were able to produce AFB and aflatoxins G but not CPA whereas, all the strains of A. tamarii produced only CPA. The obtained results revealed the presence of different species of Aspergillus section Flavi, among which were aflatoxin producers. This study provides evidence useful for considerations in aflatoxin control strategies.

International audience; This paper investigates the possibility of decomposing a control system into an interconnection of actuator and process subsystems; this allows monitoring the properties of the interconnected system globally and locally. For that, observer for the nonlinear interconnected system is studied. Specially, the interconnection between the two subsystems is assumed to be inaccessible to measurement. The aim is then to accurately estimate online the states vector of each subsystem, as well as the unknown interconnection. Numerical simulations confirm the effectiveness of the designed observer.

International audience; The ongoing development and extensions of cities, as well as the requirement for large scale deployment of renewable energy sources and electro-mobility determine the transformation of current electrical grids towards smart grids. The increasing demand and the requirement for its reliable supply is imposing new planning challenges for the development of electrical networks. The present paper describes a method of optimizing the development of urban electricity networks, by selecting from a set of available locations, the positions and the size of new power sources, using a multistage model. Results can be useful to plan the installation of new power sources in an existing network (distributed sources, renewable sources for powering electric vehicles).

International audience; During the first stages of Atomic Layer Deposition (ALD) of Al 2 O 3 on silicon (Si), the substrate nature affects the surface chemistry, leading to an initial island growth mode. Furthermore, an interfacial zone develops between the Si surface and the dielectric, thus damaging the physical properties of the deposited structure. In this work, these two main shortcomings are investigated for the ALD of Al 2 O 3 films on Si from TMA and H 2 O. The film and the interfacial zone are characterized by a complete range of techniques, including XRR, TEM, XPS, EDX and ToF-SIMS. In parallel, a computational model is developed to study the initial nucleation and growth steps of the film. An induction period is experimentally evidenced and numerically reproduced, together with the island growth and coalescence phenomena. The chemical composition of the (Al, O, Si) interfacial layer is precisely analyzed to get insight in the mechanisms of its formation. We show that Si oxidation occurs during the island growth, catalyzed by the presence of Al, while it is also fed by species interdiffusion through the ALD film.

International audience; A Lab scale algal-bacterial membrane photobioreactor (MPBR) was designed and operated under 12-h light and 12-h dark conditions with a light intensity of 8000lx, in order to investigate the effects of initial concentrations of atrazine, carbon concentration, and hydraulic retention time on the ability of this photobioreactor in simultaneous removal of atrazine and nutrients in the continuous mode. The removal efficiencies of atrazine (ATZ), chemical oxygen demand (COD), phosphorus (PO43--P) and nitrogen (NOx) in optimum condition was more than 95%, 99%, 98% and 97% when the maximum removal rates were 9.5 × 10-3, 99.231, 11.773 and 7.762mg/L-day, respectively. Results showed that the quality of the effluent was reduced by the increase of atrazine concentration. The outcomes on the hydraulic and toxic shocks indicated that the system has a relatively good resistance to the shocks and can return to the stable conditions. Microalgae showed a great deal of interest and capability in cultivating and attaching to the surface of the membrane and bioreactor, and the total biomass accumulated in the system was greater than 6g/L. The kinetic coefficients of atrazine removal were also studied using various kinetic models. The maximum atrazine removal rate was determined by the modified Stover-Kincannon model. The results approved the ability of the MPBR reactor in wastewater treatment and microalgae cultivation and growth. The decline of atrazine concentration in this system could be attributed to the algal-bacterial symbiosis and co-metabolism process. Accordingly, the MPBR reactor is a practical, simple, economical and therefore suitable process for simultaneous biodegradation of chlorinated organic compounds and nutrients removal from aquatic environments.

International audience; Concentrated solar power (CSP) plants conventionally make use of molten salt as the heat transfer medium, which transfers heat between the solar receiver and a steam turbine power circuit. A new approach uses particles of a heat-resistant particulate medium in the form of many dense upward-moving fluidised beds contained within an array of vertical tubes within the solar receiver. In most dense gas–solid fluidisation systems, particle circulation is induced by bubble motion and is the primary cause of particle convective heat transfer,which is themajor contributing mechanismto overall heat transfer. The current work describes experiments designed to investigate the relationship between this solids convection and the heat transfer coefficient between the bed and the tubewall, which is shown to depend on the local particle concentration and their rate of renewal at the wall. Experimentswere performed using 65 mmsilicon carbide particles in a tube of diameter 30mm, replicating the conditions used in the real application. Solidsmotion and time-averaged solids concentration were measured using Positron Emission Particle Tracking (PEPT) and local heat transfer coefficients measured using small probes which employ electrical resistance heating and thermocouple temperaturemeasurement. Results show that, as for other types of bubbling beds, the heat transfer coefficient first increases as the gas flow rate increases (because the rate of particle renewal at thewall increases), before passing through a maximum and decreasing again as the reducing local solids concentration at the wall becomes the dominant effect. Measured heat transfer coefficients are compared with theoretical approaches by Mickley and Fairbanks packet model and Thring correlation. The close correspondence between heat transfer coefficient and solids movement is here demonstrated by PEPT for the first time in a dense upward-moving fluidised bed.

International audience; This study performed a Life Cycle Assessment (LCA) to evaluate the environmental impact of chicken meat production from a Mexican case study, with a “cradle-to-slaughterhouse gate” approach. To overcome the LCA's limitations and provide a more holistic picture of the system, simulation and artificial intelligence techniques were integrated. First, raw material/energy requirements were obtained from the case study and simulated using Process simulation (PS) and Monte Carlo (MC) simulation to estimate the emissions and quantify their uncertainty. Then, IMPACT 2002 + was used to calculate the overall impact using Ecoinvent and LCA Food databases. The results highlight that chicken farms are the main factors responsible for the environmental impacts assessed, where feed production (use of chemicals and energy requirements) and on-farm emissions (organic waste decomposition) are the main contributors. Concerning the slaughterhouse, the energy production (electricity and steam) and the cooling-related activities present a significant impact. Afterwards, three impact allocation procedures (mass method, neural networks, and stepwise regression) were tested, showing similar results. Finally, a multiobjective optimization model based on a Genetic Algorithm was applied looking to minimize the environmental impacts and maximize the economic benefits. The selected alternative achieved a reduction of 15.14% per functional unit at the environmental indicators. The results encourage the use of support techniques for LCA to perform a reliable assessment and an environmental/economic optimization of the system.

This paper regards the experimental study on the polymerization of vinyl chloride droplets in quiescent state using microreactors. As presented in a previous work performed with methyl methacrylate monomer, this work presents results on the reaction kinetics of vinyl chloride (VCM) polymerization monitored by Raman spectroscopy and on the evolution of VCM droplets as captured by charge-coupled device (CCD) camera in a microcapillary. Different experimental recipes were proposed using commercial initiators in order to compare the system performance when initiated with monofunctional and bifunctional peroxides. For the first time in the open literature the evolution of VCM droplets is shown up to high conversions in quiescent state. It is also shown how the pressure drop can modify the PVC particle morphology at the end of polymerization. Finally, it is shown that the Raman technique is able to monitor the reaction kinetics at different conditions, being possible to identify four different characteristic stages during the vinyl chloride polymerization reactions.

International audience; Biofilm-based bioprocesses are increasingly used in wastewater treatment. Microbial adhesion constitutes the key step in stability of these depollution systems. For adhesion studies, physicochemical characterization of microbial cells and supports has proved to be of extreme importance. In this work, estimation of interaction between five yeast strains with a high potential for Cr (VI) removal using extended Derjaguin–Landau–Verwey and Overbeek (XDLVO) theory as a powerful predictive tool of adhesion was investigated. Predictions showed that wood husk could be a good support for the formation of tested yeast biofilm, beech and oak exhibit better properties than other wood species studied with 100% of potential for adhesion. From a thermodynamic point of view, pine and teak woods are not suitable for biofilm formation for all tested yeast strains, presenting positive values of free energy adhesion (ΔGXDLVO). Environmental scanning electronic microscopy (ESEM) and Matlab® image analysis confirmed that all tested yeast strains were able to adhere to pine wood and, except for Wickerhamomyces anomalus they were unable to adhere to oak wood. Adhesion experiments were found to be well related to the theoretical prediction. To our knowledge, this is the first study dealing with biofilm-mediated depollution from an adhesion point of view aiming to optimize the stability of the system. It allows expanding knowledge about adhesion phenomena of yeast strains on wooden surface and contributes to select the best biofilm-support combination that would be used in a performant biological system for chromium removal.

International audience; Sore throat is one of the most common reasons for consultation in general medicine. Besides the usual allopathic drugs, phytotherapy can be envisaged for its management. To assess the relevance of a product combining extracts of sage and elder, peppermint essential oil, honey and zinc for the management of sore throat, its effect was evaluated in vitro against the main pathogens involved in sore throat (broth microdilution method) and in a prospective observational study carried out in pharmacies. Bactericidal activity was observed against all Gram-negative (Branhamella catarrhalis, Fusobacterium nucleatum and Haemophilus influenzae) and Gram-positive (Streptococcus pyogenes) bacteria strains; antiviral activity was also tested against type 3 para-influenzae virus. Product activity was maintained at 1:64 dilution ratio. Data collected during the observational study suggest that the product can relieve pain and other symptoms such as dry throat sensation and erythema within 17 minutes on average after spraying. While eliminating possible pathogens involved, the product could relieve pain and symptoms associated with sore throat. These results will have to be confirmed in a clinical trial.; Le mal de gorge est un des motifs de consultation en médecine générale les plus fréquents. Pour le soulager, outre les traitements allopathiques usuels, la prise de produits de phytothérapie peut être envisagée. L’intérêt d’un produit de phytothérapie associant des extraits de sauge et de sureau, de l’huile essentielle de menthe poivrée, du miel et du zinc dans la prise en charge du mal de gorge a été évalué in vitro en mesurant son activité sur les principaux pathogènes impliqués dans les angines (microméthode en milieu liquide) et au cours d’une enquête observationnelle prospective conduite en pharmacie d’officine. Une activité bactéricide a été observée à la fois sur les bactéries à Gram négatif (Branhamella catarrhalis, Fusobacterium nucleatum et Haemophilus influenzae) et à Gram positif (Streptococcus pyogenes) étudiées ainsi qu’une activité antivirale vis à-vis du virus para-influenzae de type 3. Cette activité a été maintenue après dilution du produit au 1/64. Les données recueillies au cours de l’étude observationnelle suggèrent que le produit de phytothérapie peut soulager le mal de gorge et les symptômes associés en particulier la sensation de gorge sèche et l’érythème dans un délai de 17 minutes en moyenne après pulvérisation du produit. Tout en éliminant les éventuels pathogènes impliqués, le produit de phytothérapie pourrait donc soulager la douleur et les symptômes associés au mal de gorge. Ces résultats devront être confirmés au cours d’une étude clinique.

International audience; In this work, the performance of an innovative magnetic responsive biocatalytic membrane reactor (BMRSP) has been investigated under various operational parameters. In particular, feed concentrations, flow rates across the bed, temperature and amount of biocatalytic bead were varied to probe the flow-dependent transport and kinetic properties of the reaction and the subsequent hydrolytic performance of the BMRSP. The rate of fouling for the BMRSP was always lower than a corresponding control system. For a given enzymatic concentration, a constant foulant hydrolyzing capacity is identified. At 3 g/m2 pectinase containing bionanocomposites, the BMRSP hydrolytic efficiency was 1.5 g/m2 h. This efficiency was further increased by increasing the amount of bionanocomposites per membrane area. This further allowed the BMRSP to hydrolyze higher loads of foulants while keeping a low if not zero increase in TMP over time at constant flux. Identification of an optimal operating condition laid the platform for continuous operation of the BMRSP over 200 h, without visible transmembrane pressure drift while maintaining constant flux. Product assay in the permeate gave constant value in the entire duration, i.e., no enzymatic activity decay owing to stable enzyme immobilization and no leakage through the pores of the membrane owing to the synergistic magnetic interaction between the magnetic membrane and magnetic bionanocomposites. The obtained stability over a broad range of operational parameters and sustainable performance over long period gives a high prospect to the newly developed BMRSP to be utilized in continuous biocatalysis and separation, thereby significantly improved process efficiency.

International audience; The initial substrate inhibiting island growth and the formation of an interfacial layer with uncontrollable characteristics are the two main drawbacks of the Atomic Layer Deposition (ALD) of high-k metal-oxide gate dielectrics on silicon (Si). In this paper, we investigate the ALD of Al2O3 films from trimethyl aluminum and H2O, on fluorhydric acid (HF) cleaned, as well as on HF-cleaned and in situ N2-NH3 plasma pretreated Si between 0 and 75 cycles. The films and their interface were characterized via Scanning Transmission Electron Microscopy coupled to Energy-Dispersive X-ray spectroscopy. The initial deposition is clearly increased on the pretreated surfaces, obtaining a linear ALD regime even after 5 ALD cycles, compared to several tens of cycles needed on HF-cleaned Si. Furthermore, a SixNy layer is formed by the N2-NH3 plasma pretreatment, which acts as a barrier layer, reducing the oxidation of the Si substrate beneath it. This analysis provides a general framework for the understanding and determination of adequate surface pretreatments, able to combat the substrate inhibited initial growth and the Si oxidation during metal-oxide ALD on Si.ACKNOWLEDGMENTS