ERC FUNDED PROJECTS

Alpha shapes were invented in the early 80s of last century, and their implementation in three dimensions in the early 90s was at the forefront of the exact arithmetic paradigm that enabled fast and correct geometric software. In the late 90s, alpha shapes motivated the development of the wrap algorithm for surface reconstruction, and of persistent homology, which was the starting point of rapidly expanding interest in topological algorithms aimed at data analysis questions. We now see alpha shapes, wrap complexes, and persistent homology as three aspects of a larger theory, which we propose to fully develop. This viewpoint was a long time coming and finds its clear expression within a generalized version of discrete Morse theory. This unified framework offers new opportunities, including (I) the adaptive reconstruction of shapes driven by the cavity structure; (II) the stochastic analysis of all aspects of the theory; (III) the computation of persistence of dense data, both in scale and in depth; (IV) the study of long-range order in periodic and near-periodic point configurations. These capabilities will significantly deepen as well as widen the theory and enable new applications in the sciences. To gain focus, we concentrate on low-dimensional applications in structural molecular biology and particle systems.

1 678 432 €

Start date: 2018-07-01, End date: 2023-06-30

Compound semiconductor solar cells are providing the highest photovoltaic conversion efficiency, yet their performance lacks far behind the theoretical potential. This is a position we will challenge by engineering advanced III-V optoelectronics materials and heterostructures for better utilization of the solar spectrum, enabling efficiencies approaching practical limits. The work is strongly motivated by the global need for renewable energy sources. To this end, AMETIST framework is based on three vectors of excellence in: i) material science and epitaxial processes, ii) advanced solar cells exploiting nanophotonics concepts, and iii) new device fabrication technologies. Novel heterostructures (e.g. GaInNAsSb, GaNAsBi), providing absorption in a broad spectral range from 0.7 eV to 1.4 eV, will be synthesized and monolithically integrated in tandem cells with up to 8-junctions. Nanophotonic methods for light-trapping, spectral and spatial control of solar radiation will be developed to further enhance the absorption. To ensure a high long-term impact, the project will validate the use of state-of-the-art molecular-beam-epitaxy processes for fabrication of economically viable ultra-high efficiency solar cells. The ultimate efficiency target is to reach a level of 55%. This would enable to generate renewable/ecological/sustainable energy at a levelized production cost below ~7 ¢/kWh, comparable or cheaper than fossil fuels. The work will also bring a new breath of developments for more efficient space photovoltaic systems. AMETIST will leverage the leading position of the applicant in topical technology areas relevant for the project (i.e. epitaxy of III-N/Bi-V alloys and key achievements concerning GaInNAsSb-based tandem solar cells). Thus it renders a unique opportunity to capitalize on the group expertize and position Europe at the forefront in the global competition for demonstrating more efficient and economically viable photovoltaic technologies.

2 492 719 €

Start date: 2017-01-01, End date: 2021-12-31

Atmospheric aerosol particles and trace gases affect the quality of our life in many ways (e.g. health effects, changes in climate and hydrological cycle). Trace gases and atmospheric aerosols are tightly connected via physical, chemical, meteorological and biological processes occurring in the atmosphere and at the atmosphere-biosphere interface. One important phenomenon is atmospheric aerosol formation, which involves the production of nanometer-size particles by nucleation and their growth to detectable sizes. The main scientific objectives of this project are 1) to quantify the mechanisms responsible for atmospheric new particle formation and 2) to find out how important this process is for the behaviour of the global aerosol system and, ultimately, for the whole climate system. Our scientific plan is designed as a research chain that aims to advance our understanding of climate and air quality through a series of connected activities. We start from molecular simulations and laboratory measurements to understand nucleation and aerosol thermodynamic processes. We measure nanoparticles and atmospheric clusters at 15-20 sites all around the world using state of the art instrumentation and study feedbacks and interactions between climate and biosphere. With these atmospheric boundary layer studies we form a link to regional-scale processes and further to global-scale phenomena. In order to be able to simulate global climate and air quality, the most recent progress on this chain of processes must be compiled, integrated and implemented in Climate Change and Air Quality numerical models via novel parameterizations.

2 000 000 €

Start date: 2009-01-01, End date: 2013-12-31

Cavitation is the formation of vapor cavities inside a liquid due to low pressure. Cavitation is an ubiquitous and destructive phenomenon common to most engineering applications that deal with flowing water. At the same time, the extreme conditions realized in cavitation are increasingly exploited in medicine, chemistry, and biology. What makes cavitation unpredictable is its multiscale nature: nucleation of vapor bubbles heavily depends on micro- and nanoscale details; mesoscale phenomena, as bubble collapse, determine relevant macroscopic effects, e.g., cavitation damage. In addition, macroscopic flow conditions, such as turbulence, have a major impact on it. The objective of the BIC project is to develop the lacking multiscale description of cavitation, by proposing new integrated numerical methods capable to perform quantitative predictions. The detailed and physically sound understanding of the multifaceted phenomena involved in cavitation (nucleation, bubble growth, transport, and collapse in turbulent flows) fostered by BIC project will result in new methods for designing fluid machinery, but also therapies in ultrasound medicine and chemical reactors. The BIC project builds upon the exceptionally broad experience of the PI and of his research group in numerical simulations of flows at different scales that include advanced atomistic simulations of nanoscale wetting phenomena, mesoscale models for multiphase flows, and particle-laden turbulent flows. The envisaged numerical methodologies (free-energy atomistic simulations, phase-field models, and Direct Numerical Simulation of bubble-laden flows) will be supported by targeted experimental activities, designed to validate models and characterize realistic conditions.

2 491 200 €

Start date: 2014-02-01, End date: 2019-01-31