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Reference : UMR7274-FRALAP-001
Workplace : NANCY
Date of publication : Monday, October 11, 2021
Type of Contract : FTC Scientist
Contract Period : 13 months
Expected date of employment : 1 December 2021
Proportion of work : Full time
Remuneration : The duration of the contract is 13 months with a gross monthly salary of approximately 2,675 euros (which corresponds to an experience of less than two years after obtaining the doctorate).
Desired level of education : PhD
Experience required : Indifferent
Introduction to the scope:
Electrophoresis is one of the main techniques for the analytical separation of biological molecules. The apparatus consists of a microfluidic cell continuously supplied with a fluid mixture to be purified. Under the effect of an orthogonal electric field, charged molecules (e.g., proteins) are deflected by a distance proportional to their electric charge to mass ratio. The various components of the mixture are thus separated and collected at the outlet of the cell.
However, the intense electric field to be applied leads to a large volume production of heat by the Joule effect. In order to reduce the formation of hot spots (which can denature the biomolecules), on the one hand, an efficient cooling system is necessary, and on the other hand, the thickness of the microfluidic vein must be limited to only a few hundred microns. . This latter constraint restricts the operational capacity of the cell in terms of throughput, thus preventing the deployment of electrophoresis on an industrial scale.
The present research work, co-financed by BPI France (within the framework of the IT'SME project), aims to improve the design of electrophoresis cells in order to increase their productivity in order to be closer to industrial working conditions. The ANSYS-Fluent CFD package will be used to finely simulate the hydrodynamics and the various transfer phenomena (thermal, material and electrical) governing the quality of the separation. The numerical results will be compared with the experimental measurements acquired by the project partners for validation. Once the reliability of the CFD model has been established, it will be used to explore new geometries to identify designs that maximize processing capabilities while ensuring optimal separation quality.
• Establish the material, thermal, electrical and momentum balances of the carrier fluid in order to go back to the velocity and temperature fields in a pilot cell for capillary electrophoresis.
• Establish the balance of the forces applied to biomolecules subjected to a potential gradient, using the related assumptions, adapted to the constraints of the bio-electrochemical separation process;
• Numerically simulate the trajectories of charged molecules through the electrophoretic cell for different operating conditions (electric field intensity, pH values, buffer and physicochemical properties of the carrier fluid as well as its flow rate) and go back to the quality of the separation. The numerical results will be validated by comparison with the experimental measurements carried out by colleagues from the IT'SME project.
• Find the optimal design of an electrophoresis cell of semi-industrial capacity, adapted to high separation fluxes and allowing an efficient separation of different biomolecules presenting a strong economic and societal stake such as RNA or active principles of vaccines.
* Numerical CFD-type simulation (using the Ansys Fluent package) of the functioning of the existing electrophoretic cell from established physical / physicochemical models;
• Adaptation of the model to the constraints of the semi-industrial cell to be designed and simulated;
• With the partner teams in charge of the experimental tests (in an existing cell) and the preparation of the media to be separated, validation and calibration of the models, first on standard media, then on more complex media with high stakes;
• Drafting of technical and scientific reports intended for the project partners as well as the funding organization;
• Oral presentation of the objectives, results obtained and fallback or progression solutions to consider
We are looking for a motivated candidate with a doctorate in process engineering and / or fluid mechanics and / or thermal-energy and / or physics. He will have to present a taste for numerical simulation. Expected skills:
• Expertise in fluid mechanics, thermics, and more generally in physics and numerical simulation;
• Basic knowledge in physicochemistry and biochemistry appreciated;
• Writing skills in French and / or English, as well as skills in presenting work to different audiences;
• Good interpersonal skills and integration skills both in the host group and with the other academic, hospital and industrial partners of the project.
• This post-doc work is part of the IT'SME research project, supported by BPI France, and coordinated by Edith Lecomte-Norrant, inventor of the current electrophoresis cell and CEO of IPSOMEL in Marseille;
• Most of the work will be carried out at the LRGP laboratory (CNRS - University of Lorraine) in Nancy under the supervision of MM. Rainier Hreiz and François Lapicque.
• Frequent exchanges by videoconference will be organized with the project partners (MITNOV, IPSOMEL, INSERM). Travels to Marseille are also planned.
Constraints and risks
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