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In this work a fully partitioned Lagrangian framework for the solution of fluid–structure interaction (FSI) problems involving free surfaces, large solid displacements and deformations, and strong added mass effects is presented. The fluid is simulated using the Particle Finite Element Method (PFEM), while Metafor, a large deformations nonlinear Finite Element code, is employed to simulate the solid part. The fully partitioned coupling is ensured through an Interface Quasi-Newton Inverse Least Squares (IQN-ILS) (Degroote et al., 2009) strategy to avoid added mass effects. The Lagrangian particle nature of the PFEM allows the simulation of problems involving free surfaces and very large solid displacements, usually difficult to achieve with traditional body-fitted CFD techniques. We show that owing to the generality of its formulation the PFEM can be used as is in the framework of fully partitioned FSI coupling schemes, where minimal information (i.e. loads and displacements at the FSI interface) is exchanged between the fluid and the solid solvers. More importantly, we demonstrate that a fully partitioned PFEM–FEM coupling based on the IQN-ILS strategy allows the simulation of a very large spectrum of FSI problems without incurring added-mass instabilities. The performance of the IQN-ILS coupling strategy in a fully Lagrangian framework is also assessed and compared to more traditional approaches such as Block-Gauss–Seidel (BGS) iterations with Aitken relaxation. An extensive work of verification and benchmarking is proposed, aiming to encompass all the combinations of physical and numerical parameters possibly leading to added-mass instabilities, and testing the IQN-ILS strategy on different benchmarks beyond those already proposed in the literature. The coupling is performed through CUPyDO (Thomas et al., 2019), a general Python framework for partitioned FSI coupling.

CUPyDO, a fluid-structure interaction (FSI) tool that couples existing independent fluid and solid solvers into a single synchronization and communication framework based on the Python language is presented. Each coupled solver has to be wrapped in a Python layer in order to embed their functionalities (usually written in a compiled language) into a Python object, that is called and used by the coupler. Thus a staggered strong coupling can be achieved for time-dependent FSI problems such as aeroelastic flutter, vortex-induced vibrations (VIV) or conjugate heat transfer (CHT). The synchronization between the solvers is performed with the predictive block-Gauss-Seidel algorithm with dynamic under-relaxation. The tool is capable of treating non-matching meshes between the fluid and structure domains and is optimized to work in parallel using Message Passing Interface (MPI). The implementation of CUPyDO is described and its capabilities are demonstrated on typical validation cases. The open-source code SU2 is used to solve the fluid equations while the solid equations are solved either by a simple rigid body integrator or by in-house linear/nonlinear Finite Element codes (GetDP/Metafor). First, the modularity of the coupling as well as its ease of use is highlighted and then the accuracy of the results is demonstrated.

The Particle Finite Element Method (PFEM) is evaluated in the context of the numerical simulation of bird strike events. To assess the possibilities of the method, theoretical analyses are initially performed based on the impact of a water jet on a rigid surface. Then, the influence of the geometry of a more realistic projectile is analyzed and the capability of the method to take into account separation and fragmentation is highlighted. Finally, the method is tested for impacts against deformable targets, using a partitioned algorithm with dynamic relaxation for the fluid-structure interaction, combining the PFEM for the description of the bird with a non-linear Finite Element approach for the description of the impacted structure, which can undergo large plastic deformations. To assess the quality of the obtained results a series of numerical examples from the literature has been selected and used as a reference throughout the paper. Among the studies presented in this work also a novel numerical benchmark for the evaluation of bird impact simulations is proposed.

The Particle Finite Element Method (PFEM) is evaluated in the context of the numerical simulation of bird strike events. To assess the possibilities of the method, theoretical analyses are initially performed based on the impact of a water jet on a rigid surface. Then, the influence of the geometry of a more realistic projectile is analyzed and the capability of the method to take into account separation and fragmentation is highlighted. Finally, the method is tested for impacts against deformable targets, using a partitioned algorithm with dynamic relaxation for the fluid-structure interaction, combining the PFEM for the description of the bird with a non-linear Finite Element approach for the description of the impacted structure, which can undergo large plastic deformations. To assess the quality of the obtained results a series of numerical examples from the literature has been selected and used as a reference throughout the paper. Among the studies presented in this work also a novel numerical benchmark for the evaluation of bird impact simulations is proposed.

In recent years, the development of portable platforms for performing fast and point-of-care analyses has drawn considerable attention for their wide variety of applications in life science. In this framework, tools combining magnetoresistive biosensors with magnetic markers have been widely studied in order to detect concentrations of specific molecules, demonstrating high sensitivity and ease of integration with conventional electronics. In this work, first, we develop a protocol for efficient hybridization of natural DNA; then, we show the detection of hybridization events involving natural DNA, namely genomic DNA extracted from the pathogenic bacterium Listeria monocytogenes, via a compact magnetic tunneling junction (MTJ)-based biosensing apparatus. The platform comprises dedicated portable electronic and microfluidic setups, enabling point-of-care biological assays. A sensitivity below the nM range is demonstrated. This work constitutes a step forward towards the development of portable lab-on-chip platforms, for the multiplexed detection of pathogenic health threats in food and food processing environment.

As well known, in the analysis of bird impact events the bird is often reduced, even experimentally, to a surrogate projectile modeled as a weakly compressible fluid (typically a mixture of water and air) [15] . From a numerical standpoint, the presence of a free surface and the strong interaction with the aircraft structures represent a limit for traditional computational fluid dynamics methods based on an Eulerian grid. On the other hand, classical Lagrangian methods cannot cope with the extremely large deformations experienced by the projectile during the impact. The Particle Finite Element Method (PFEM) [6] , [11] is a Lagrangian particle method that can account for very large deformations, preserving the robustness and generality of the finite element method, and thus owning a key advantage over other approaches, e.g. Smoothed Particle Hydrodynamics (SPH) [9] , usually cursed with consistency and stability issues [1] , [10] . To assess the possibilities of the method in the context of bird impact, theoretical analyses are initially performed based on the impact of a water jet on a rigid surface. Then, the influence of the geometry of a more realistic projectile is analyzed and the capability of the method to take into account separation and fragmentation is highlighted.

Resume La maladie periodique (fievre familiale mediterraneenne) est une maladie hereditaire, a transmission autosomique recessive, faisant partie des maladies auto-inflammatoires. Elle est caracterisee par des episodes recidivants, de courte duree (en moyenne 24 a 72 heures) et de resolution spontanee, comportant de la fievre et l’inflammation d’une sereuse. La maladie periodique est la plus frequente des fievres periodiques au sein des maladies auto-inflammatoires qui constituent un groupe heterogene et recemment identifie, de maladies caracterisees par des acces febriles recidivants, sans auto-anticorps, ni lymphocytes T specifiques de l’antigene. Habituellement, les crises sont declenchees par des stimuli anodins et peuvent etre precedees d’une phase prodromique. Le gene responsable de la fievre familiale mediterraneenne, appelee MEFV, est situe sur le chromosome 16 (16p13) et code pour la proteine pyrine-marenostrine. Le mecanisme physiopathologique precis de la maladie periodique necessite d’etre encore determine. Le nouveau complexe macromoleculaire appele inflammasome, qui semble jouer un role tres important dans le controle de l’inflammation, pourrait etre implique dans la pathogenie de la maladie periodique. La complication la plus severe a long terme est l’amylose AA qui atteint surtout les reins et peut entrainer une insuffisance renale chronique. Des facteurs de risque, a la fois genetiques et non genetiques, du developpement de l’amylose secondaire ont ete identifies. Actuellement, le seul traitement efficace de la maladie periodique est la colchicine. De nouvelles molecules ont ete essayees chez des patients refractaires a la colchicine, mais des etudes supplementaires portant sur des effectifs suffisants sont necessaires avant d’aboutir a des conclusions formelles.