During the cold spray process, micron-sized particles are accelerated by a supersonic nozzle and projected onto a substrate for coating purposes. Due to their relatively large size in a high-speed turbulent flow, particle inertia plays a fundamental role in the process. A detailed knowledge of the gas/particle velocity fields is hence essential for the prediction of the particle deposition rate. This project aims to provide, for the first time in this flow, coupled gas/particle measurements by the use of twocolor particle image velocimetry.

The project is part of a collaboration between the laboratories, LMA, IRPHE, LAMPEA (Aix-en-Provence), CEPAM (Nice, Sofia Antipolis) and the LC2R (Draguignan). It concerns the characterization of human and animal bones for applications in archeo-anthropology (study of ancient and paleolithic funerary rites) and zoo-archaeology (study of conservation in taphonomy, and paleolithic strategies of subsistence by bone fracturing). There is a large literature on the identification of the physico-mechanical properties of different elements and portions of human or animal bones with a recent or short postmortem interval, but very few studies, other than densitometry, on prehistoric human or animal bones. It is a challenge for the acoustic engineering and paleo-archaeology communities to study these bones.

The aim of this work is to carry out a global study from the rheological properties of microalgae suspensions to a microfiltration membrane process. The aim is to determine under which operating conditions the microalgae could break. The integrity of these microalgae suspensions is evaluated as a function of the operating conditions using X ray tomography, TEM and MEB. The complementary aspect of these techniques should allow the determination of average but also individualized information about microalgae.

• Topic supervised by Antonin COUTANT (LMA) & Cédric BELLIS (LMA)

Metamaterials is now a rich and mature field of research, with a wide range of potential applications for mechanical waves. One can think of the possibilities in waveguiding, for instance to redirect seismic energy to a target location, or in isolation for soundproofing. These artificial materials usually rely on a given periodic structure, which gives the waves exotic propagation properties. A key question in this context is whether these properties are maintained in the presence of irregularities or defects. In the last decade, the field of topological wave insulators has emerged from analogies with electrons in metals, to realize wave guiding with strong robustness against defects1. Within this class of structures, a very peculiar one has been predicted called the Topological Anderson Insulator (TAI). In this type of structure, the waveguiding properties arise because of disorder, making it inherently robust to fabrication defects and imperfections (...)

• Supervised by Olivier BOIRON (IRPHE) & Audrey SORIC (M2P2)

The Research topic concerns the study of biofilm development dynamics in micro/milli fluidic labyrinth systems. In a context of increasing water stress and competition for water resources in agriculture, microirrigation systems have been recommended for several years. These systems enable greater efficiency of water supply at plot level, but this efficiency can be compromised quite drastically by the presence of nutrients and ions in irrigation water, particularly in the case of reuse of treated wastewater, which increases the possibility of biofilm development in drippers (...)

The aim of this project is to initiate collaborations in the framework of stochastic modelling for fluid dynamics. Taking into account uncertainties in physical phenomenon modelling is of major importance. There exist several methods dealing with data which take into account different sources of uncertainty. In this project, the main purpose is to use stochastic processes having the physical deterministic fluid dynamic model as average and taking into account expert knowledge. The project is in the crossroad of fluid mechanics, applied mathematics and data science.

The aim of thid project is to determine the rheological properties of real mucus. Using a new transportable rheometer working on sample volumes as low as 70ul, we propose an exhaustive experimental characterization and a modelling of real mucus rheology in the context of improving the clearance process of patients, either suffering from chronical pathologies (severa Asthma, COPD or Cystic Fibrosis) or acute ones (such as COVID-19) that can lead to Severe Acute Respiratory Syndrom.

This project associates the complementary expertise of LMA (aero-acoustics, low frequency noise reduction), IRPHE (flow modelling and characterization) and CSIC (micro-perforated metamaterials) to investigate aero-acoustic solutions for aeronautics and wind turbine sectors: the development of slow sound metamaterials with acoustically neutral interfaces in order to achieve both flow-induced noise attenuation and low drag performance under sheared industrial flows.

Non-linear dynamics is at the heart of sound production in a wide variety of musical instruments. Wind instruments (flutes, brasses, woodwinds) relying on self-sustained oscillations are heavily studied at LMA with existing experimental supports. Here, we here aim at developing teaching material to highlight the non-linear behavior of structures when vibrations amplitude become large. Such structures in a musical context correspond percussion instruments such as cymbals or gongs. More precsely, focus is put on the various sounds produced by large gongs, which have proved to display a wide range of behaviours, from linear modal regime to pitch glides or even chaos and wave turbulence.

Semi-anechoic rooms are used by manufacturers for the acoustic characterization of products. The objective of the DADA project is to prove that it is possible to realize a semi-anechoic room with an active technology. The idea is to create a full-scale functional demonstrator whose active system developed would make it possible to erase the acoustic effect of 5 walls (not the floor). This project will make it possible to create the first room with active anechoicity.