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Environmental changes can alter the nursery function of coastal areas through their impact on juveniles' growth and survival rates, an effect mediated by individuals' chronic stress response. Fish chronic stress can be quantified using scale cortisol but no study has yet been quantified the spatio-temporal variations in scale cortisol and its relationship with growth in wild nurseries. We collected wild sea bass juveniles (Dicentrarchus labrax, four years, three nurseries) and found that scale cortisol levels increased consistently with age and across cohorts in 2019 and 2020 probably due to greater stress history in older fish and/or heatwaves that occurred in summers of 2018 and 2019. Growth was impaired in fish with high scale cortisol in 2019 and 2020, confirming the usefulness of scale cortisol as a biomarker of broad and local constraints in wild fish; longer time series will enable us to identify environmental factors underpinning these temporal variations.

International audience; The main purpose of this study is to better understand the relationship between the microstructure of foamed polymer and mechanical properties. X-Ray tomography was performed on polypropylene foam specimens machined from injected plates. These plates were obtained for different thicknesses and exhibit different microstructure morphologies. The tomography scans were first digitalized and meshed. Then, numerical simulations were performed on representative volume elements (RVEs) to get homogeneous mechanical property of the material using a parallel C++ library Cimlib developed at CEMEF. Numerical methods described in this study focused on immerged or body-fitted strategy (FE context - level set framework - meshing adaptation) for exact and statistical RVEs generation. The numerical results were compared to experimental testing performed under tension and compression at different strain rates using image correlation. Good agreement was observed between simulations performed at the mesoscale and experimental tests carried out at the macroscale for both real and statistical RVEs. This methodology opens a way for the development of digital materials designed for specific mechanical properties.

Chemical contaminants are one of the causes of the ongoing degradation of coastal and estuarine nurseries, key functional habitats in which the juveniles of many marine species grow. As chemical contaminants can cause a decrease in the energy available and induce defence mechanisms reducing the amount of energy allocated to life history traits, quantifying their effect on the fitness of juvenile fish is key to understand their population-level consequences. However, these effects are primarily estimated experimentally or in the wild but on a limited number of contaminants or congeners that do not reflect the wide variety of chemical contaminants to which juvenile fish are exposed. To address this issue, we measured concentrations of 14 trace metal elements (TMEs) and bioaccumulative organic contaminants (OCs) in European sea bass juveniles (1-year-old) from three major French nurseries (Seine, Loire and Gironde estuaries). We tested the hypotheses that (i) levels and profiles of contaminants differed among studied nurseries, and ii) fish growth and body condition (based on morphometric measurements and muscle C:N ratio) were lower in individuals with higher contaminant concentrations. Multivariate analyses showed that each nursery had distinct contaminant profiles for both TMEs and OCs, confirming the specific contamination of each estuary, and the large array of contaminants accumulated by sea bass juveniles. Increasing concentrations in some TMEs were associated to decreased growth, and TMEs were consistently related to lower fish body condition. The effect of OCs was more difficult to pinpoint possibly due to operational constraints (i.e., analyses on pooled fish) with contrasting results (i.e., higher growth and decreased body condition). Overall, this study shows that chemical contaminants are related to lower fish growth and body condition at an early life stage in the wild, an effect that can have major consequences if sustained in subsequent ages and associated with a decline in survival and/or reproductive success.

International audience; An innovative liquid rotational moulding process aiming at using standard injection-moulding polymer grades, shortening cycle times and at accessing more higher-end markets is studied. In this new process, the polymer is melted beforehand in a conventional injection unit and injected into the mould rotating around two axes. This work focus on modelling the liquid polymer flow occurring in this process, as well as providing guidance on the choice of process parameters. First, a stability criterion for rimming flow is derived, defining the process and material parameters space available for a functional process. From this criterion, it appears that initial thickness, and density have a destabilising effect, while liquid viscosity and angular velocity have a stabilising effect. Next, using Lax-Friedrichs scheme, the one-dimensional transient gravity driven liquid film is numerically modelled, linking the total extent of spreading to the frequency of orientation reversals and to the major and minor angular velocities ratio : the closer this ratio to one, the larger the extent of spreading. Then, Computational Fluid Dynamics (CFD) simulations are carried out to take into account three-dimensional features in the moulding of a cube part. Finally, comparison with trials performed on the moulding of the same cube part validates entirely this approach. In particular, some peculiar features of spreading can only be explained and reproduced when employing three-dimensional CFD simulations.

International audience; Thanks to an aerogel formulation, an efficient heterogeneous modification of chitosan is described and offers the convenient covalent-functionalisation of primary amine of insoluble microspheres into secondary benzylic-amines with various functionalities. The SEC, XRD and textural analyses provided a better insight into the chitosan aerogels and showed that this synthetic process allows high substitution ratio (> 80%) without depressing the desirable properties of the well-defined chitosan macromolecular structure. As a proof of principle, original catalytic chitosan aerogels flanked by a phosphine-pendant were prepared and applied successfully in the heterogenous pallado-catalyzed allylic substitution reaction.

A theoretical-computational protocol to model the Joule heating process in nanocomposite materials is presented. The proposed modeling strategy is based on post processing of trajectories obtained from large scale molecular simulations. This protocol, based on molecular models, is the first one to be applied to organic nanocomposites based on carbon nanotubes (CNT). This strategy allows to keep a microscopic explicit picture of the systems, to directly catch the molecular structure underlying the process under study and, at the same time, to include macroscopic boundary conditions fixed in the experiments. As validation and first application of the proposed strategy, a detailed investigation on CNT based organic composites is reported. The effect of CNT morphologies, concentration and working conditions on Joule heating has been modelled and compared with available experiments. Further experiments are performed also in this work to increase the number of comparisons especially in specific voltage ranges where available references from literature were missing. Simulations are in both qualitative and quantitative agreement with several experiments and trends reported in the recent literature, as well as with experiments performed in this work. The proposed approach combined with large scale hybrid particle-field molecular simulations can give insights and opens to way to a rational design of self-heating nanocomposites. This journal is

An efficient diastereoselective access to all carbon-substituted oxazolo-pyrrolidinones, including a quaternary carbon stereocenter, is described. This was achieved by using a domino process between hydroxy halogenoamides and various Michael acceptors. This strategy provided good to high yield and selectivity. Application to the diastereoselective synthesis of an enantioenriched spirooxindole skeleton in high yield and selectivity is also presented.

International audience; Geometrical and appearance quality requirements set the limits of the current industrial performance in injection molding. To guarantee the product’s quality, it is necessary to adjust the process settings in a closed loop. Those adjustments cannot rely on the final quality because a part takes days to be geometrically stable. Thus, the final part geometry must be predicted from measurements on hot parts. In this paper, we use recent success of Generative Adversarial Networks (GAN) with the pix2pix network architecture to predict the final part geometry, using only hot parts thermographic images, measured right after production. Our dataset is really small, and the GAN learns to translate thermography to geometry. We firstly study prediction performances using different image similarity comparison algorithms. Moreover, we introduce the innovative use of Discrete Modal Decomposition (DMD) to analyze network predictions. The DMD is a geometrical parameterization technique using a modal space projection to geometrically describe surfaces. We study GAN performances to retrieve geometrical parameterization of surfaces.

International audience; Injection molded part quality can be improved by precise process adjustment, which could rely on in-situ measurements of part quality. Geometrical and appearance quality (visually and sensory) requirements are increasing. However, direct measurement is often not feasible industrially. Therefore, process control must rely on a prediction of parts quality attributes. This study compares prediction performances of diverse neural networks architectures with "classical" regression algorithms. Dataset comes from inline industrial measurements. Regression was performed on 97 scalar statistical features extracted from multiple acquisitions sources: thermographic images and analog signals. Haralick features were extracted. Convolutional Neural Networks were trained on thermographic images and Long Short Term Memory networks were trained on raw signals. Although the dataset was small, neural networks show better predictions scores than other regression algorithms.

The access to new oxazolo[3,2-d][1,4]oxazepin-5(3H)-ones starting from α-bromoamido alcohols and Michael acceptors under mild conditions is presented. This domino process proved to be chemo-, regio-, and stereoselective and allows the formation of a large diversity of highly functional 7-membered rings in good yields up to 95%. The complete shift of the regioselectivity of the intermediate enolate from a C–C to a C–O bond formation, contrary to the already known alkylations of such ambident nucleophiles, is mostly triggered by steric effects. The last step of the sequence was modeled by DFT giving some important insights for this C–C vs C–O bond shift.

The subject discussed in this article concerns the determination of optimal sensor (pressure & temperature) configurations for polymer injection moulds. A sensor configuration is considered optimal when it is able to predict the product quality (dimension, warpage, etc.) with a good accuracy (from experimental data provided by these sensors). Initially, plastic engineers integrated sensors in moulds to acquire knowledge about their processes and to have better understanding of physical phenomenon. This article presents a numerical methodology to identify optimal combinations of sensors. The methodology is firstly based on polymer injection molding simulation to collect virtual sensor data. In a second step, virtual sensor data are analyzed by modern data-driven modeling techniques to identify optimal sensor configurations.

An original and rapid domino reaction for access to oxazolidin-4-ones is presented. Simply by heating α-bromoamido alcohol in the presence of KNaCO3 and water with readily prepared Michael acceptors, an unprecedented molecular rearrangement is generated. This new methodology enables the hitherto unreported synthesis of functionalized oxazolidin-4-ones. The process was proved to be compatible with a wide variety of substrates, and high regioselectivities were achieved.

In this paper, we present in a first time a methodology used to determine the thermophysical properties and the crystallization kinetics of a thermoplastic reinforced composite (MXD6). A specific instrumented device was developed to allow the molding of the polymer in conditions as close as possible to those met in the injection process. Measurements during molding are used by two inverse problems to compute the thermal conductivity in melted and solid phases and the kinetic parameters. The estimated values of thermal conductivity are compared to a model based on the orientation of the fibers through the thickness. Results from kinetics are compared to literature one. Heat transfers are then studied during the injection by using an instrumented mould. It is shown that during filling the heat transport term in the flow direction is negligible in front of transfer between the part and the mold. Then transfers are modelled within the thickness of the part by solving the energy equation coupled with the crystallization kinetic. The effects of pressure and shearing are introduced in the kinetic model through empirical acceleration functions. Results show that the shear seems to have no influence on the thermal contact resistance at the interface between the mould and the composite.

A series of bicyclic lactams is prepared by a base-mediated reaction of hydroxyl halogenoamides with corresponding Michael acceptors.

The total synthesis of the alkaloid (±)-coerulescine is presented. The key step of this approach is an efficient tandem aza-Michael initiated ring closure (aza-MIRC) process between ethoxymethylene-oxindole and benzyl(2-bromoethyl)carbamate. The potency of the aza-MIRC reaction was first tested onto less challenging Michael acceptors and led in good yields to the corresponding N-Cbz α-alkoxy-β-gem-disubstituted pyrrolidines. The resulting N-acyliminium precursor obtained from ethoxymethylidene-oxindole was efficiently converted in four steps, including 2 deprotections, into the targeted (±)-coerulescine.

This paper describes the synthesis of both polysubstituted oxazolo-pyrrolidinones and -piperidinones by a domino process. The methodology is based on the reaction between hydroxyl halogenoamides and Michael acceptors, which leads efficiently to bicyclic lactams. The process is compatible with unsymmetrical electron-withdrawing groups on the Michael acceptor, which allows the formation of two contiguous and fully controlled tertiary and quaternary stereocenters. In the case of tetrasubstituted Michael acceptors, two adjacent quaternary stereocenters are formed in good yield. Starting from (R)-phenylglycinol derived amides results in the formation of enantioenriched bicyclic lactams in low to good yields and with high levels of stereoselectivity, thus greatly increasing the scope and interest of this strategy. The origins of chirality transfer and diastereoselectivity were studied by DFT calculations and have been attributed to a kinetic control in one of the last two steps of the reaction sequence. This selectivity is dependent upon both the substituents on the Michael acceptor and the sodium cation chelation.

A simple protocol is presented for the tandem reaction between Michael acceptors (I) and carbamate (II) to yield pyrrolidine derivatives.

A series of tetrasubstituted pyrrolidines is synthesized by an aza-Michael induced ring-closure tandem reaction of bromide (II) with Michael acceptors (I), (IV), and (VI).

Injection is one of the most used processes to manufacture thermoplastic parts. The design of the cooling channels in this process is of great importance during the mould design. Indeed, an inappropriate cooling will lead to defects in the part and a low production rate. In this paper, a new approach for the design of the cooling channels is assessed. Based on morphological concepts, the idea of regulation by cooling surface is introduced. The thermal behaviour of the mould can be restricted on the spatial domain delimited by the cooling surface on which a spatial temperature distribution is imposed. The first step of the methodology leads to the optimal determination of the fluid temperature distribution along the cooling surface in order to minimize a cost function composed of two terms linked to the quality of the part and the productivity of the process. The conjugate gradient algorithm coupled with a Lagrangian technique is implemented for the determination of fluid temperature parameters. However, the obtained solution is not workable in practice. The second step consists then in building real channels from this optimal distribution. The shape, location and fluid temperature level of these channels are determined a posteriori from the thermal analysis of the temperature field in the mould domain located between the plastic part and the cooling surface. Channels are builded by using the contours of isotherms in the thermal steady-state area of the mould. It becomes then possible to design the cooling channels with no a priori on the numbers, the location of these channels and on the temperature of the coolant fluid. The methodology is first illustrated with a 2D part. Results are compared with literature.Copyright © 2012 by ASME

Dimethyl 1,19-nonadecanedioate is produced from the methoxycarbonylation of commercial olive, rapeseed or sunflower oils in the presence of a catalyst derived from [Pd2(dba)3], bis(ditertiarybutylphosphinomethyl)benzene (BDTBPMB) and methanesulphonic acid (MSA). The diester is then hydrogenated to 1,19-nonadecanediol using Ru/1,1,1-tris-(diphenylphosphinemethyl)ethane (triphos). 1,19-Nonadecadienoic acid is hydrogenated to short chain oligoesters, which can themselves be hydrogenated to 1,19-nonadecanol by hydrogenation in the presence of water.

Diethyl carbonate and propylene carbonate are good solvents for Pd-catalyzed arylation of a variety of heterocyclic compounds, e.g. benzoxazole, oxazoles, thiazoles, furans, thiophenes, and pyrroles.

The palladium-catalysed direct 2-, 4- or 5-arylation of a wide range of heteroaromatics with aryl halides proceed in moderate to good yields using the eco-friendly solvents carbonates. The best yields were obtained using benzoxazole or thiazole derivatives. The arylation of furan, thiophene, pyrrole, imidazole or isoxazole derivatives was found to require a more elevated reaction temperature.

International audience; Bien-bon-ates. Carbonates offer an environmentally friendly alternative to standard polar solvents. Since a few years, carbonates have been employed successfully for some classical metal-catalyzed reactions. Here, the palladium-catalyzed direct 2-arylation of oxazole derivatives in carbonate solvents is reported.

We present experimental results and theoretical analysis of heat transfer during injection moulding of a fibber reinforced semi‐crystalline thermoplastic (IXEF). This one is a PA MXD6, with a mass fibber ratio of 30% and 50%. We illustrate the influence of the source term of crystallization on the surface temperature of the polymer, inducing strong influence of the pressure and of the shear during filling on this temperature.

An aza-Michael induced ring closure (aza-MIRC) tandem reaction of benzyl (2-bromoethyl)carbamate with various Michael acceptors is described. The N-Cbz-β-gem-disubstituted pyrrolidines thus obtained were proved to be versatile intermediates for the rapid access to both martinelline and spirooxindole backbones. An application of this strategy towards an expedient 4 step total synthesis of (±)-coerulescine is also presented.

Dans le cadre du Contrat de Plan Etat- Région de Basse Normandie 2000 à 2006, le Laboratoire Environnement Ressources s'est vu confier la maîtrise d'ouvrage du programme « Suivi et qualité du milieu marin » dont l 'objectif général est de développer des outils et compétences permettant d'élaborer des aides à la prise de décision en matière d'aménagement et de gestion de l'environnement littoral en Basse Normandie. Ce programme associe le Conseil Régional de Basse Normandie, le Conseil Général de la Manche/SMEL, /'Agence de /'Eau Seine Normandie, le Conseil Général du Calvados et l'IFREMER. Il comprend 4 grands volets : réalisation d'une veille scientifique, technique et réglementaire dans les domaines de l'environnement et de l'aménagement littoral, ainsi que dans celui du traitement ou de la gestion des déchets et rejets ; rédaction de synthèses annuelles des données des 3 réseaux animés par l'IFREMER (RNOIREMI/REPHY), et portant sur la qualité des eaux, milieux et productions du littoral ; développement d'un Système d'information Géographique « environnement littoral », avec l'objectif de rédiger un atlas « état des lieux » à l 'horizon 2003/2004 ; développement d'un réseau de modèles hydrodynamiques couvrant l'ensemble du littoral Bas Normand, et permettant de réaliser des simulations d'impact de différents aménagements, ou du devenir (dilution, dispersion, diffusion au gré des courants) de différents rejets (hors radionucléides et sels nutritifs), et de leurs impacts potentiels. Le contrat stipule que le laboratoire doit chaque année éditer un rapport d'activité présentant l'ensemble des actions et tâches réalisées au cours de l'année écoulée, et recensant les objectifs à atteindre lors de l'année en cours. Le suivi et la validation des travaux sont réalisés par le Comité de Suivi Technique, constitué de représentants de l'ensemble des partenaires précités, et mis en place à cet effet. Ce rapport présente donc les principaux résultats obtenus lors de l'exercice 2003 et les objectifs à atteindre en 2004.