ERC FUNDED PROJECTS

Roughness on most natural and man-made surfaces shares a common fractal character from the atomic to the kilometer scale, but there is no agreed-upon understanding of its physical origin. Yet, roughness controls many aspects of engineered devices, such as friction, adhesion, wear and fatigue. Engineering roughness in surface finishing processes is costly and resource intensive. Eliminating finishing steps by controlling roughness in primary shaping or in subsequent wear processes could therefore revolutionize the way we manufacture, but this requires a deep understanding of the relevant processes that is presently lacking. Roughness emerges during mechanical deformation in processes such as folding, scratching or chipping that shape surfaces. Deformation occurs in the form of avalanches, individual bursts of irreversible motion of atoms. The central hypothesis of this project is that roughness is intrinsically linked to these deformation avalanches, which themselves are well-documented to be fractal objects. This hypothesis will be tested in large-scale atomic- and mesoscale simulations of plastic forming and fracture on state of the art high performance computing platforms. Results of these calculations will be used to develop process models for evolving the topography of large surface areas under the action of an external mechanical force, such as experienced in shaping, finishing or wear. In addition to these simulations, a public repository for sharing topography data will be build. This repository is the connection to experiments: It is a database of experimental topographies whose contents will be mined for features identified in simulations. Beyond the present project, this web-repository will advance sharing, visualization and analysis of topography data, and aid researchers to correlate surface topography with surface functionality and processing. Simulations and database lay the foundation for a rational design of surface functionality in manufacturing.

1 499 101 €

Start date: 2018-02-01, End date: 2023-01-31

The SPAGAD project will investigate speech acts, the basic linguistic units with communicative function. It is made possible by recent breakthroughs in our understanding of speech acts as devices to change the world by establishing new commitments and constrain the future development of a conversation. The project will propose a formal model for speech acts. In the light of this model it will investigate the role of speech acts in three areas. It will elucidate their role in grammar in typologically diverse languages: how they are expressed by morphological, syntactic and prosodic means, how expressions like adverbials and clause-embedding verbs can operate on them, and how they can be integrated in a formal model of the syntax/semantics interface. It will investigate speech acts in discourse: how they are used to enrich the common ground, how they can be employed to negotiate conflicts in the development of conversation, how questions, contrastive topics and discourse particles are devices that restrict the development a discourse can take, and how the choice of one speech act out of set of alternatives creates pragmatic effects like bias in questions or politeness in commands. And it will explore speech acts in communication: What are the societal norms of different speech acts, like the prohibition against asserting falsehoods, which strategies can increase or decrease the commitments of speakers, how does the context influence the type of commitments, how do social groups within one language community differ, what are the difference across language communities, how are the societal norms that come with speech acts acquired? The SPAGAD project will have a major impact on linguistic semantics and pragmatics; it will reconceive them by a model theory based on commitments, rather than truth. Due to the pivotal role of speech acts, it will offer new perspectives for syntax, discourse studies, psycholinguistics, sociolinguistics and the philosophy of language.

2 499 945 €

Start date: 2019-01-01, End date: 2023-12-31

Most anatomical compartments, including mucosal barrier surfaces, solid organs and vascular spaces host different types of tissue-resident lymphocytes providing local networks for immune surveillance and front-line defense to microbial invasion. In addition to immediate effector functions, tissue-resident lymphocytes orchestrate and regulate inflammatory responses, and contribute to tissue homeostasis, repair and barrier function. Understanding the generation and function of tissue-resident lymphocytes is therefore expected to reveal targets for improving vaccination and immunotherapy. Barrier tissues of free-living mice and men, but not those of laboratory mice kept under specific pathogen free conditions, are continuously exposed to an array of antigenically complex pathogens, microbial symbionts and environmental factors, which dramatically alter the abundance, composition and basal activation state of local pools of tissue-resident cells. Therefore, we propose to study the development, functions and cellular interactions of tissue-resident lymphocytes in experimental models that mirror “real-life” contexts. First, we will investigate how polyclonal pools of tissue-resident memory CD8+ T cells (TRMs) are established during infection with antigenically complex pathogens. Second, we will restore physiologic exposure to specific pathogens and induce alterations of local microbiota in SPF mice, in order to investigate the induction, function and local interactions of tissue-resident lymphocytes in physiologic tissue environments. In addition, we will explore targeted microbial exposure as a „vaccination“ strategy to induce „non-canonical“ tissue-resident cells in the lung in order to improve protection against infections with multi-resistant bacteria representing major clinical problems in hospitalized patients. In summary, we will investigate fundamental mechanisms of tissue immunity and vaccination in contexts relevant for human physiology and disease.

1 498 750 €

Start date: 2018-03-01, End date: 2023-02-28

Tribology, the science of interacting surfaces in relative motion, is crucial for many aspects of modern life. Friction and wear decisively impact the lifetime and durability of many products-from nanoelectromechanical systems to gears and engines. In the USA alone, an estimated 1E18 joules of energy could be saved each year through improved tribological practices. During sliding of a metallic contact, a mutated surface layer forms, carries most further plastic deformation and largely determines friction and wear. The origin and evolution of this distinct subsurface layer remains elusive, since our knowledge of the elementary mechanisms promoting these changes is limited. Only this knowledge however will allow for a strategic tailoring of tribologically loaded metals. In this project, we will elucidate these elementary mechanisms for a wide range of alloys and strain rates. We will develop ground-breaking new strategies for probing the subsurface microstructure during the tribological test itself with non-destructive testing sensors like ultrasound and eddy current, resulting in subsurface in situ tribology. The data from these sensors will be analysed online, during the tribological experiment, relying on cutting edge data science methods as they have already been applied for fatigue testing. Based on these analyses, implemented on a Field Programmable Gate Array, we will interrupt the test exactly when the dominating elementary mechanisms manifest themselves. These mechanisms will then be revealed by sophisticated electron microscopy and be visualized in deformation mechanism maps for unidirectional and reciprocating sliding. Such maps have proven very successful in other fields of materials science, e.g. creep at elevated temperatures. They are used to guide material selection and alloy development processes, yielding materials tailored for each specific tribological scenario, promising enormous savings in energy and resources, an important challenge of our time.

1 985 048 €

Start date: 2018-09-01, End date: 2023-08-31