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PhD subjects

3 sujets IRAMIS

Dernière mise à jour : 25-01-2020


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• Materials and applications

 

Lightweight, impact-resistant 3D-printed metamaterials for radioactive waste transport packages; Design of optimal architectures in a bio-inspired approach

SL-DRF-20-0591

Research field : Materials and applications
Location :

Service de Physique de l’Etat Condensé

Systèmes Physiques Hors-équilibre, hYdrodynamique, éNergie et compleXes

Saclay

Contact :

Daniel BONAMY

Starting date : 01-10-2020

Contact :

Daniel BONAMY
CEA - DSM/IRAMIS/SPEC/SPHYNX

0169082114

Thesis supervisor :

Daniel BONAMY
CEA - DSM/IRAMIS/SPEC/SPHYNX

0169082114

Personal web page : http://iramis.cea.fr/Pisp/2/daniel.bonamy.html

Laboratory link : http://iramis.cea.fr/spec/SPHYNX/

More : http://iramis.cea.fr/nimbe/lions/

The clean-up and dismantling operations of the former nuclear research facilities generate large amount of waste which must be transported in complete safety to the centers for storage and/or treatment. Transport packages are multilayer, waterproof devices, designed to stop ionizing radiation, but also to resist mechanical shocks, punching, thermal constraints, etc. These constraints make current packages very heavy, difficult to handle, and increase the doses received during their handling.



This thesis project aims to design a new class of materials for transport packages, both ultra-light and compatible with the mechanical / thermal constraints encountered. In this context, microlattice-type metamaterials (formed from periodically arranged microtubes) prove to be promising: In addition to being much lighter than massive materials (several orders of magnitude!), they seem to offer higher compressive strength . the goal is first to understand why microlattices exhibit such a high compressible strength , and then to develop the proper tools to optimize the lattice architecture in this context. In particular, in a bio-inspired approach, we will explore the potential brought by random and hierarchical architectures. The study will be based on numerical approaches of “Lattice beams model” with increasing complexity. These approaches will be qualified through experiments carried out on metamaterials obtained by additive printing. This thesis is backed by another more chemistry and materials oriented thesis, aimed at designing the best resin / nanoadditive composites to optimize protection against ionizing radiation, neutrophagic properties and resistance to irradiation.



This thesis subject implies a taste for teamwork as well as an important scientific curiosity and open-mindedness. It brings into play concepts belonging to mechanical engineering, non-linear physics and materials science. The successful candidate will have the opportunity to manipulate the theoretical, numerical and experimental tools used in these three areas. The fundamental and applied nature of this research will allow the candidate to find opportunities at the end of his thesis in the academic world and in industry.
Measurement of accidental radiation exposure by radio-induced defects in smartphones screens

SL-DRF-20-0586

Research field : Materials and applications
Location :

Laboratoire des Solides Irradiés

Laboratoire des Solides Irradiés

Saclay

Contact :

François Trompier

Nadege OLLIER

Starting date :

Contact :

François Trompier
IRSN -


Thesis supervisor :

Nadege OLLIER
CEA - DRF/IRAMIS/LSI

01 69 33 45 18

Personal web page : http://iramis.cea.fr/Phocea/Membres/Annuaire/index.php?uid=ollier

Laboratory link : https://portail.polytechnique.edu/lsi/fr

In case of a large-scale radiological emergency, methods are needed to identify individuals in the

population who have been exposed and require immediate soins ?. There are no operational methods to date. The

glasses of smartphones' touch screens keep in "memory" the trace of an irradiation with ionizing radiations by the

formation of so-called "radio-induced" defects. The measurement and quantification of these point defects, in

particular by electron paramagnetic resonance spectroscopy (EPR), makes it possible to estimate the dose deposited

in the glass and thus to estimate the exposure associated with the irradiation. However, an increased understanding of

the nature of the stable defects involved and their stability is necessary. Indeed, the nature of the point defects and

their properties are not known, moreover they are very dependent on the generation of Gorilla glass (Corning).

The aim of this thesis is to propose approaches or methods to quantify some of the defects that may be related to the dose delivered. Defects that are not induced by UV will be preferred.
In-situ silica porous membranes and fluidized beds built within microfluidic systems for biotechnology applications

SL-DRF-20-0547

Research field : Materials and applications
Location :

Service Nanosciences et Innovation pour les Materiaux, la Biomédecine et l’Energie

Laboratoire Interdisciplinaire sur l’Organisation Nanométrique et Supramoléculaire

Saclay

Contact :

Florent Malloggi

Patrick GUENOUN

Starting date : 01-09-2020

Contact :

Florent Malloggi
CEA - DSM/IRAMIS/NIMBE/LIONS

+3316908 6328

Thesis supervisor :

Patrick GUENOUN
CEA - DRF/IRAMIS/NIMBE/LIONS

01-69-08-74-33

Personal web page : http://iramis.cea.fr/nimbe/Pisp/florent.malloggi/

Laboratory link : http://iramis.cea.fr/nimbe/lions/

Macroscopic packed and fluidized beds consist of beads packed in a container with a porous membrane at the bottom through which a fluid can be homogeneously injected. Such devices are widely used for liquid¬-solid exchange processes because of their high surface to volume ratio. Downsizing this concept in microfluidics is a hot topic particularly for biotechnology applications where limited/expensive sample volume is often a strong constrain. We propose the original idea of synthesizing anchored porous silica membranes within microfluidic channels, in order to prepare packed and fluidized beds able to perform enhanced liquid¬-solid exchange processes. Silica porous membranes will provide downsized equivalents to macroscopic membranes, allowing the flow of fluids while blocking the passage of micrometric solid particles, making possible the development of homogeneous beds at a micrometric scale. The effects of sol¬-gel reactions parameters on membranes properties (pores size, homogeneity, thickness, surface chemistry) and the generation of packed and fluidized beds by injection of micro/nanometric functionalized particles (polymer and inorganic micro/nanoparticles) will be investigated. Such multistage microfluidic systems are particularly suited for biomedical applications where only small volumes (10 -100 µL) are available and/or when multiple reactions are required such as enzymatic cleavages followed by chromatographic separation. Such multistep process are standard in biotechnology applications. For example, glycomic analysis is a recently developed method for biomarkers identification based on cleaving glycans from proteins followed by a separation step prior to mass spectrometry analysis. With our versatile approach, we are confident that it will be possible to validate sample preparation for glycomic analysis.

 

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