- Job type
- Job Service
- Centre for Education, Research and Innovation in Energy and Environment
- Job Location
- 941 rue Charles Bourseul, 59500 Douai
Nowadays, composite materials are being exhaustively used in the transport sector, in order to improve fuel efficiency and decrease the environmental impact. In terms of materials, glass fibers are mostly used due to their low cost, whereas in terms of mechanical performance, these composites are no match to carbon fiber composites, which are stronger, lighter but relatively costlier. In order to overcome the issue of cost- effectiveness, hybridization of composites is usually adopted where the carbon and glass fibers are either interlaminated or intermingled, and then the composites can be either manufactured using traditional processes like Liquid Composite Molding (LCM) using dry preforms or consolidation of prepregs using Autoclave. During resin impregnation, the flow mechanisms at the macro and micros scale are well understood in the case of pure carbon or glass preforms but the parameters influencing the resin flow in a hybrid
structure are not sufficiently documented in the literature.
For instance, the void formation due to air entrapment during the impregnation largely depends on the impregnation velocity in neighboring yarns. As the local impregnation mechanisms are not the same in glass and carbon yarns, the void formation mechanisms can differ. An in-depth understanding of the contribution of the process variants will be useful in the design of hybrid composites. The purpose of this project is to investigate the influence of different parameters such as constituent fiber volume fraction ratio, stacking sequence, and injection pressure/velocity and thereby relate them to the final part quality in terms of void content, void morphology and mechanical properties of the laminates.
Consequently, the objective of this master is to identify and quantify the emissions of asphalt concretes used for the construction of roads in urban sites, under simulated atmospheric conditions. The speciated emissions from asphalt concrete surfaces will be estimated in micro and macro scale, employing temperature regulated atmospheric simulation chambers that can mimic the real conditions existing in the atmosphere (i.e. temperature, humidity, sunlight). In addition, he impact of atmospheric oxidants (i.e. O3, NOx, etc.) to asphalt concrete emissions, as well as the possible formation of SOA, will be investigated. State of the art instrumentation (GC-FID/MS, PTRMS, SIFT-MS, HPLC, NOx and ozone analyzers) will be used to characterize the volatile and semivolatile organic fraction (of nearly 100 species from C2 to C16, including alkanes, alkenes, alcohols, aldehydes/ketones, aromatic compounds etc.) of asphalt concrete emissions. The anticipated sound results will be provided to collaborators and be implemented in chemical transport models aiming to evaluate whether asphalt concrete can be an important source of organic compounds in the atmosphere and what could be the consecutive impacts on air quality of urban cities in the context of climate change.
The successful candidate should have a strong background in analytical chemistry. Basic computer skills and knowledge on data treatment softwares (Excel, Origin Pro) will be required. Motivation and good communication skills will be highly appreciated.
Laboratory : CERI Energie et Environnement / unité de recherche Sciences de l’Atmosphère et Génie de l’Environnement (SAGE)
Period : 6 months
Salary : 500 – 600€ / month