ERC FUNDED PROJECTS

In this project we develop new algorithms for the solution of general nonlinear systems of time dependent partial differential equations (PDE) in the context of non-ideal magnetized multi-fluid plasma flows with thermal radiation. We will produce new high order schemes on unstructured tetrahedral meshes that are applicable to a rather general class of problems in general geometries, thus opening a wide range of possible applications in science and engineering. We will consider both, Eulerian methods on fixed grids and Lagrangian schemes on moving meshes to reduce numerical diffusion at material interfaces. A particular feature of our schemes is that they are high-order one-step methods based on local space-time predictors that allow using time-accurate local time stepping, i.e. each element runs at its own optimal time step. Even nowadays better than second order accurate 3D unstructured Eulerian methods are very rare, but there is still no better than second order accurate unstructured Lagrangian scheme available on general tetrahedral meshes. To develop these missing algorithms is the objective of our research project. A very challenging application that we have in mind is inertial confinement fusion (ICF) which is highly relevant for modern society and its increasing need for clean and inexhaustible energy. It is believed that early ICF experiments in the 1970ies failed because they did not reach the necessary critical pressure and temperature due to hydrodynamic instabilities in the flow. In this project we propose to design algorithms for simulating ICF flows with billions of high order elements on up to 100,000 CPUs of modern supercomputers. We will also propose active control strategies based on adjoint equations to reduce the hydrodynamical instabilities. Hence this project aims at providing next-generation numerical modeling tools for a possible future scenario of clean civil energy production via ICF.

918 000 €

Start date: 2011-11-01, End date: 2016-10-31

Within proteins, cysteine residues are sensitive to oxidation by reactive oxygen species (ROS). The first oxidation product of cysteines exposed to ROS is the sulfenic acid derivative (-SOH). Sulfenic acids are highly reactive intermediates that, unless they are stabilized within the protein microenvironment, react with another cysteine present in the vicinity to form a disulfide or are further oxidized to the irreversible sulfinic (-SO2H) and sulfonic (-SO3H) acid modifications. Sulfenic acid formation has traditionally been viewed as an unwanted reaction opening the way to damages that are harmful to proteins. However, it has become clear in recent years that formation of sulfenic acids is not always deleterious to the cell. A new concept is emerging, in which sulfenylation of specific cysteine residues modulates signal transduction pathways by altering the activity and function of cellular proteins, just as phosphorylation and dephosphorylation cycles regulate enzyme activities and cellular pathways. However, the modulation of protein function by sulfenic acid formation has been unambiguously shown for only a few proteins. We postulate that specific oxidation of cysteine residues via sulfenylation modulates the activity of many more proteins and pathways and that numerous sulfenylation sites have not yet been recognized. We want to apply an unprecedented multi-facetted approach to fully grasp the physiological scope of cysteine sulfenic acid formation by uncovering the sulfenome of a living organism, using Escherichia coli as a model. The main objectives of our research program are (1) to comprehensively characterize the sulfenome of E. coli, 2) to identify new proteins and pathways regulated by sulfenylation and (3) to understand how sulfenyla-tion is controlled at the cellular level. If our hypothesis proves to be true, our project will uncover a new “redox dimension” affecting many cellular processes and pathways, opening up new avenues of investigation.

1 492 000 €

Start date: 2011-11-01, End date: 2016-10-31

In this project I will exploit new possibilities opened up by the recent succesful demonstration of our ability to create electron vortex beams in a transmission electron microscope. Electron vortex beams carry a helical phase and angular momentum around their propagation axis. They form the counterpart of optical vortex beams that were invented almost 20 years ago and have lead to many exciting new applications in optics. In preliminary experiments with electron vortices I have demonstrated (Verbeeck et al. Nature, 467,301 (2010)) their usefulness for magnetic state mapping. This property makes them very desirable for solid state physics and materials science since no other tool exists that can map the local magnetisation inside materials with atomic scale resolution. We aim to develop atomic resolution magnetic state mapping and apply it to gain insight in spintronics devices as well as in topological insulators. We will follow two routes to this end, one using the combination of electron vortex beams and electron energy loss spectroscopy (EELS) and another making use of the Aharanov Bohm effect in elastic scattering. Preliminary experiments proof that both routes are feasible and a wealth of interesting physics is ready to be explored. We will also explore the potential of electron vortex beams to manipulate nanoparticles and transfer angular momentum from the electron beam to these particles. This would open up the road to assemble and create nanoscale devices and to study the fundamental laws that govern the interaction between vortex beams and particles with different physical properties. I believe that this highly creative and innovative idea, combined with access to a state of the art transmission electron microscope and a young PI with a proven track record is combined into a project proposal entirely in the spirit of the ERC starting grants.

1 458 300 €

Start date: 2012-01-01, End date: 2016-12-31