PhD : selection by topics
Mathematics - Numerical analysis - Simulation
Biochemistry
Optics - Laser optics - Applied optics
Solid state physics, surfaces and interfaces
Biotechnologies,nanobiology
Biotechnology, biophotonics
Analytic chemistry
Electronics and microelectronics - Optoelectronics
Materials and applications
Thermal energy, combustion, flows
Mechanics, energetics, process engineering
Physical chemistry and electrochemistry
Medical imaging
Instrumentation
Electromagnetism - Electrical engineering
Radiation-matter interactions
Chemistry
Automatics, Remote handling
Nuclear physics
Ultra-divided matter, Physical sciences for materials
Neutronics
Biotechnologies,nanobiology
Biotechnology, biophotonics
Biochemistry
Materials and applications
Solid state physics, surfaces and interfaces
Electronics and microelectronics - Optoelectronics
Theoretical Physics
Ultra-divided matter, Physical sciences for materials
Chemistry
Engineering science >> Thermal energy, combustion, flows
6 propositions.
Numerical modeling of solute transport phenomena and implementation of a mixing system in a crystallization pilot for photovoltaic silicon
Today, photovoltaic cells are mostly fabricated using silicon substrates. The most common technique used in industry involves ingot directional solidification from a liquid bath. Then, these ingots are cut into wafers which are processed into solar cells. The main research objective in the field is focused on the reduction of the production costs with two major trends: an ingot size increasingly bigger and the use of lower quality silicon compared to the electronic industry standard. In this context, the issue of control of convection in the silicon melt becomes decisive, specially regarding impurity segregation issues. The purpose of the thesis is to optimize the convective field in the melt during the growth of silicon ingots by directional solidification. To reach this objective, the candidate will initially identify the most appropriate methods. Then the candidate will have to implement one experimental water set up to characterize qualitatively and quantitatively the flow generated. Finally, the candidate will have to develop the corresponding numerical simulation models and use experimental measurements as a basis for parametric adjustment.
See the summary of the offerEmbedded broadband measurement of electrical impedance - application to batteries
The context of the study is the monitoring of the state (charge, aging, security) of a battery of an electric vehicle. The thesis aims the embedded identification of the electrical impedance of the battery taking into account the non-linearity of the system. This objective should help to overcome the limitations of existing measurement systems (spectroscopy, linear broadband identification). The design of the architecture of the system identification, the development of the signal processing, and tests will be conducted in close collaboration with the LITEN, CEA laboratory developing innovative accumulators and batteries.
See the summary of the offerPressure effect on High Temperature Steam Electrolysis (HTSE) to produce hydrogen and store new intermittent energies
High Temperature Steam Electrolysis (HTSE) is one of the most promising ways to produce massively hydrogen with no carbon dioxide emission and also to store renewable energies. This process with solid oxide cells runs at high temperature (>700°C). The use of the vapor phase and the high temperature conditions allow a significant decrease in the electrical energy consumption for the electrolysis step. The substitution of part of this electrical energy by cheaper thermal energy leads to a better global process output. Additionally, performing HTSE under pressure is of major interest, since on one hand it should allow increasing the cell performance and on the other hand at the system level it avoids a hydrogen compression step that is energetically costly. The CEA aims to demonstrate the role of this pressure increase. This thesis work provides an experimental part to collect steam electrolysis data under high pressure (30 bars), a microstructure part to characterize the electrochemical cells and modeling part.
See the summary of the offerDefinition and implementation of protocols intended for the energy evaluation of buildings and for the information of their users
The complexity of buildings does not allow to totally control the knowledge of the level of consumption based only on numerical simulations. On the other hand, understanding building behavior only from measurements would imply a huge investment to deploy enough probes to get valuable information. A compromise solution consists in coupling the real time simulation with a metrology limited to a small number of sensors. The work will consist in defining scenarios of building thermal solicitations in order to experimentally determine the time shift or the damping effect on temperature for an existing building. This approach will then be tested within the framework of an international competition called the Solar Decathlon Europe which will consist in comparing the energy consumption in real time on 20 houses coming from all over the world.At the end we will have an objective and inexpensive evaluation method that could be implemented in a more general context to evaluate the performance of new or retrofitted buildings.
See the summary of the offerInterconnection methods for high efficiency photovoltaic cells : materials, process, characterization of electrical performance and reliability.
High efficiency cells are developed at INES. The aim is to keep high efficiency at module level. The interconnection of the cells is a key point, as the standard interconnection technique is not compatible with the materials used for the cell. Innovative interconnection technologies will be studied. The materials and process will be developed and characterized. Electrical performance of modules will be measured after module fabrication and after accelerated tests. The aim is to obtain high efficiency and reliable modules. The work is mostly experimental: development of processes and characterization.
See the summary of the offerIntelligent onboard electronics for Concentrator Photovoltaic technologies
In an energetic market mainly based on fuel energies, renewable energies are gaining more and more market share thanks to economics and politics support. Among this new market and technologies, photovoltaic is one of the more promising ones. The CEA-INES is working for long years in the development of new PV technologies and more recently is involved in high efficiency photovoltaic, also Concentrator Photovoltaic (CPV). CPV modules consist in an optical element concentrating a big amount of sunlight onto small area and high efficiency photovoltaic cells. The use of an optical system leads to the use of tracker which role is to align the module to the sun in order to form an image of the sun on the cell. CPV technologies are emerging compared to classic PV technologies, however, with conversion efficiencies twice higher, they are considered as a very promising alternative. In CPV modules, the cells are series connected and mounted along a by-pass diode. This by-pass diode is used to disconnect the cells showing degraded performances. Due to the exigent assembling tolerances needed in CPV, some alignment problem between cells and optics can induce some inhomogeneity in terms of efficiency. In this case, the by-pass diode can ?disconnect? the affected cell. This phenomenon avoids extracting the maximum power of the CPV module. However, CPV modules are usually of great size and filled by air. This means that they physically room to include new functionalities such as onboard intelligent electronics. In the frame of this PhD, we proposed to design an intelligent electronic board able to make each cell of the CPV module working at its maximum power point instead of disconnecting the cell with defects such as misalignment. Moreover, this electronic could be coupled to a small energy storage component in order to create an energy buffer (from the inverter point of view) to reduce the constraint applied in the case of a cloudy day. At the end of this PhD, a prototype will realized and integrated to a CPV module for an infield characterization. This PhD is aimed to work on a very foreground technology. For this reason, this thesis will have a great potential in terms of innovation, publications and patents.
See the summary of the offer