The RACOON project (Coherent dual-comb lidar adapted to the marine environment) is part of the development of new underwater imaging techniques, both for military applications (threat detection, intrusion, monitoring of sensitive sites, etc.) and civilian (resource detection, submerged works monitoring, navigation safety and wreck inspection...). This project aims to validate the concept of a coherent underwater lidar, develop a prototype, then test it and characterize its performances under realistic conditions of underwater environment. RACOON therefore proposes to go beyond the state of the art of underwater lidar, which is based so far exclusively on an incoherent approach, that is to say that the signal detected is the light intensity. On the contrary, the coherent approach, which relies on the detection of the electric field, offers a priori important advantages. Indeed, in this approach, the signal varies as the inverse of the distance to the target (against the inverse square in the incoherent approach). In addition, the detection of the field makes possible the filtering of the photons diffused by the particles suspended in the sea water, and therefore must significantly increase the signal-to-noise ratio. Finally, coherent detection offers the possibility of measuring the movements or speeds of the target. First, we will demonstrate the relevance of the coherent approach on a 532 nm laboratory test system, which will allow a simple direct comparison of coherent and in coherent configurations. This test system will also be characterized during the project, in the seawater tank DEXMES of the Laboratoire Géo-Océan, in Brest, which allows to have controlled marine environments (turbidity, flow velocity). Then we will develop a coherent lidar prototype in the blue-green spectrum. This prototype is based on an architecture well mastered by the FOTON Institute, a double loop with frequency shift (or bi-directional loop). Initially, a 1550 nm loop will be made on the basis of the experience acquired by the laboratory on previous projects (ANR COCOA, ANR Astrid MECHOUI). A tripling frequency stage will reach the blue-green region (517 nm), suitable for underwater propagation. This prototype, which uses the principle of dual-comb and multi-heterodyne detection, must offer a sub-centimeter resolution. It will be tested first in the DEXMES tank, then, at the end of the project, in the IFREMER instrumented channel (50 m) which will characterize the performance of the prototype under realistic conditions, in terms of scope, resolution, signal to noise, and the ability to measure movements and speeds. In parallel, a technology watch task will be conducted on the sources and components in the blue-green spectrum. For the moment, the performances of these do not allow the realization of a dual-comb system directly in this spectral range, but we anticipate in the long run this possibility, which will greatly simplify future coherent underwater lidar systems. The RACOON project is a 36-month, single-partner project led by two teams from the FOTON Institute, in Rennes and Lannion. It will draw on the experience and know-how of external collaborators (). The work will be carried out by researchers, faculty members, and technical staff of the FOTON Institute, with the help of a postdoctoral researcher recruited for theis project.

Many bacterial cells are able to connect their metabolism with an electrode. Since the publication of the pioneering articles of 2002, the variety of bacterial species that have proved to be capable of extracellular electron transfer (EET) has been constantly expanding, and it now seems to be a current and ubiquitous lifestyle for microbial cells. EETs are most often correlated with essential metabolic pathways, particularly the respiratory metabolism of bacteria. The electrochemical approach of EETs is thus revolutionizing the understanding of microbial processes in most ecosystems. Numerous elements of the biomedical literature show that similar EETs, i.e. involving metabolic pathways, exist with human cells. For example, stem cells are commonly grown on conductive materials whose electrochemical properties drive differentiation into the different phenotypes. The exchange of extracellular electrons, in the form of "bioelectricity", is known to play essential roles in tissue repair or organ morphogenesis. In addition, human cells are eukaryotic cells and EETs associated with metabolic pathways have already been evidenced with yeasts, which are also eukaryotic cells. Despite the accumulation of indirect evidence of the occurrence of EETs with human cells, electrochemical approaches have never been implemented in this context before. Using the experience gained on microbial EETs by the consortium, the TECH project aims to build the electrochemical devices that will bring to light metabolic EETs with human cells. Three types of cells will be implemented: i) MRC5 lung cells, which have already given promising preliminary results, ii) progenitor cells from human adipose tissue, whose differentiation into white or beige adipocytes is related to the status of the respiratory metabolism and, iii) different cancer cell lineages, as the cancerous state of the cells could be correlated with dysfunction of the respiratory metabolism. The objective is to create the electrochemical reactors and electrode surfaces and to design the operating and analytical procedures that will allow EETs to be characterized during the development and/or differentiation of cells. The project will build synergy between two research groups belonging to the same laboratory, one mastering the EETs of microbial cells and the other the culture of human cells. In addition, two experts in the cellular metabolism of stem cells and cancer cells are associated as consultants. An interdisciplinary group will thus be created to combine skills in bioelectrochemistry, electroanalysis, cell adhesion, culture and cellular metabolism, and to couple electrochemical analysis methods with biochemical, biological and imaging techniques by microscopy. The project is submitted to the “Défi des autres savoirs” because the objective is to bring experimental evidence of a new paradigm. The project is applying for a modest budget because the objective is not to push investigations towards fundamental biology. This is a seminal project that intends to prove the concept of EET with human cells in order to convince the biomedical communities and to build further projects with them, having larger budgets on specific applied objectives. Demonstrating the occurrence of EETs with human cells will pave the way to new stem cell culture techniques, new tools for investigating cellular metabolisms and the pathologies, such as obesity and cancer, which are associated with their dysfunction and, we hope, will bring to light new therapeutic pathways.

Gas-solid fluidized beds are widely used in processes for energy. In all these processes the short-range (van der Waals forces) and medium-range (electrostatic) particle-particle interaction forces may have a strong influence and reduce the operation energetic efficiency. In these processes electrostatic charge generation is undesired and needs to be minimized as much as possible. Due to the very nature of gas-solid fluidization, which involves significant particle-particle and particle-reactor wall interactions the occurrence of electrostatic charge generation, is almost unavoidable. The overall process upsets associated with this phenomenon includes particle agglomeration, reactor wall fouling generated by particle-wall adhesion, defluidization and electrostatic discharge. Generation of high-voltage electrical fields could cause electrical interference, adversely affecting process instrumentation, physical shocks to operating personal and, most significantly, fires, explosions and therefore be a major hazard. The excess accumulation of electrostatic charges can have a severe impact on fluidized-bed dynamics, particle mixing, and fines elutriation which is a major cause of inefficiency. For particles the van der Waals forces can have an effect, as it is known for the cohesive powders (very fine particles), combined electrostatic charges. In that case, the short-range interactions lead to attractive forces between the particles and consequently modify the bubble size and thus the macroscopic behavior of a fluidized-bed reactor. Depending on the process requirements, the particle size of the solid material ranges from several microns to few millimeters. The objective of this project is twofold: to develop a new experimental technique to characterize the coupling between hydrodynamics of the gas-solid suspension and inter-particle short and medium-range action forces in fluidized bed reactor and to develop CFD models through a multi-scale approach to take into account these forces to simulate pilot plant reactor in order to design, to control the process and to optimize industrial fluidized bed reactors. In this project, multi-scale numerical and experimental approaches are coupled. Mathematical models to represent inter-particle forces at micro-scale will be implemented in the Euler-Euler formalism at macro-scale scale according to the kinetic theory of granular material. Euler-Euler simulations will be carried out and the results will be compared to the hydrodynamic measurements realized on a fluidized bed mock-up submitted to inter-particle short and medium-range action forces. The hydrodynamics measurements will be carried out according to a new technique never applied, to our knowledge, to fluidized bed in Europe. This technique, called Electrical Capacitance Volume Tomography (ECVT), provides 3D non-intrusive measurements of the flow structure. This technique will be coupled to measurements of electrostatic charge of the particles and the wall. When the Euler-Euler simulations are validated, numerical simulations on industrial scale will be carried out. This project involves the LGC and the IMFT, which have strong complementary approaches and skills on the fluidized bed. It allows the coordinator to develop a real autonomy and his own research activity. The originality of this project lies in several points: 1-Experimental measurements on particles with different electrostatic charges from particles of different size and different materials. 2-Local non-intrusive measurements of gas-particle suspension hydrodynamics by ECVT. 3-ECVT system applied to fluidized bed submitted to electrostatic and van der Walls forces. 4-Three dimensional numerical simulations of dense fluidized bed influenced by inter-particle forces. 5-Coupled experimental, theoretical and numerical approaches to study inter-particle short and medium-range action forces in fluidized bed coupled in the same project

The delivery of polynucleotides such as messenger RNA is now industrialized via vectorization in lipid nanoparticles. These nano-objects are nanocomposites in which the mRNA is condensed by complexation with a cationic lipid and coated with a shell of phospholipids and cholesterol. Their synthesis involves several rapid supramolecular assembly processes, including nanoprecipitation of hydrophobic lipids by solvent switching, electrostatic complexation of mRNA with cationic lipids to form a coacervate, and self-assembly of lipids. If the industrial production of these objects is now recorded, several challenges remain to be met to ensure their full development and generalization as a vaccine and therapeutic tool. Thus, their structure is complex, highly dependent on the formulations and the process, and there is no consensus. The efficiency of encapsulation and delivery remains very empirical and improvable. The process conditions, in particular the mixing of the species and the purification by filtration, are not optimized because the elementary mechanisms and their kinetics are not described. Storage conditions remain complex and the efficiency of encapsulation and delivery must also be improved. Finally, costs must be lowered. The Prosalide project targets to deliver a detailed understanding of the complete manufacturing chain thanks to a multidisciplinary team combining skills in physical-chemistry of assemblies, micro and millifluidics, filtration, hydrodynamics, microbiology, structural characterization. We will study in detail the assembly phenomena via the intensified establishment of phase diagrams. We will deploy a micro/millifluidic tandem allowing rapid mixing of solutions, in operando characterization and purification by tangential filtration. This approach will make it possible both to exploit the potential of microfluidics for the screening and characterization of mechanisms and that of millifluidics, which is the industrial production scale for these objects. We will propose new synthetic routes based on the use of composition sequences. Finally, we will quantify in detail the internal structure of the objects, their ability to encapsulate and deliver the polynucleotide, and their metastability. The PROSALIDE project will thus provide generic and free knowledge to understand the link between formulation, synthesis path, mesostructure, metastability, encapsulation and delivery.

“Crystallization from solution must surely rank as the oldest unit operation, in the chemical engineering sense and it is known since the dawn of civilization” (Mullin, 1960). However, despite many experimental and theoretical developments, and despite its great interest in chemical, biological and natural processes, crystallization remains a puzzling phenomenon coupling several mechanisms (nucleation, growth, aggregation, agglomeration) occurring at different time and length scales. The crystallization process is still poorly understood mainly because crystal nucleation mechanisms are not clearly identified. The essential difficulties of studying nucleation and developing an accurate theory of the process arise from: 1/ the stochastic nature of nucleation, 2/ the fact that the objects involved during the process are small 3/ and are short lived (few ns). In the CNOC project, we propose a basic research, combining original theoretical and experimental approaches involving a theoretical physicist, bio-physicists and chemical engineers, to get a better understanding of the nucleation mechanism involved during crystallization. This project aims at a real breakthrough in our understanding of the nucleation process by associating modern experimental techniques (droplet microfluidics), powerful characterization technique (Small Angle X-Ray Scattering (SAXS) from a synchrotron source) and a new and original Monte Carlo simulation. The combination of microfluidics and SAXS enables in-situ measurements, at the nanoscale, of structures involved during the nucleation process and reduce the limit of time resolution at the micro/milli second range (due the spatial-to-time conversion offered by microfluidic devices). The theoretical description of nucleation from the Monte Carlo approach, enabling to treat complex and large systems (comparable to the one expected in microfluidics), will give a general picture of the mechanism involved during the nucleation. The project stretches over 48 months, includes five main tasks and gathers researcher from four French academic laboratories internationally renowned: the Laboratoire de Génie Chimique in Toulouse, the Institut des Biomolécules Max Mousseron in Avignon, the Laboratoire de Physique des Solides in Orsay and the European Molecular Biology Laboratory in Grenoble providing complementary specialties, domains of knowledge, know-how and expertise for the good development of this inter- and multidisciplinary project. Strong interactions between each participant will enable to design and build microfluidic chips compatible with intense X-ray radiations from a synchrotron source, to perform in-situ SAXS experiments for following molecular cluster in solution during the nucleation process, and to build a new theory of nucleation. The results obtained, from a carefully chosen biological macromolecule model, in this project will highlight mechanisms involved during the nucleation process by following experimentally and numerically the temporal evolution of size, number and shape of the molecular clusters in solution: from the formation of pre-critical nuclei (before nucleation) until the emergence of the crystal.