Research Database: Projects

The epithelial sodium channel (ENaC) plays an important role in sodium and water balance. Recently, it has been shown that ENaC also controls inflammatory responses such as the release of proinflammatory cytokines by immune cells. In my PhD project I aim to identify what specific ENaC isoforms are present in immune cells and how ENaC activity influences their function.

The epithelial sodium ion channel (ENaC) is a heterotrimeric, membrane-bound protein, composed of α/δ, β, and γ subunits. ENaC is found in the epithelial cells of the kidney, lung, and colon. It mediates the reabsorption of sodium ions by allowing sodium to enter the cell. Therefore, it is essential for the regulation of the water-ion homeostasis and the control of blood pressure. Altered ENaC activity is associated with Liddle syndrome and salt-sensitive hypertension. The selective permeability of ENaC to sodium ions is maintained by the architecture of the channel and ist regulation through proteolytic cleavage in the extracellular domain. To understand how structural features of ENaC determine ion transport and channel functionality, high-performance molecular dynamics simulations employed to capture the structural dynamics of the channel. Elucidating the molecular mechanisms of the ENaC sodium channel provides critical insights into ENaC-related diseases and lays the basis for the development of novel targeted therapeutic strategies.

This doctoral thesis examines how digital spaces can be made more democratic and what role digital citizenship and political communication play in this process. The focus is on the question of how vulnerable citizens such as young people, senior citizens or people with a migration background can be protected from digital risks and whether digital platforms can improve their participation in online political processes.

Wide-bandgap semiconductors enable high-efficiency and high-power-density converters, but their fast switching causes electromagnetic emissions that must be filtered for compliance. Traditional Passive EMI Filters (PEFs), especially bulky Common Mode Chokes (CMCs), add significant size, weight, and cost. Active EMI Filters (AEFs) mitigate this by using amplifiers to cancel noise, allowing smaller and lighter passive components.

This research project investigates physical phenomena and metrological possibilities for the non-invasive ageing determination of power semiconductor modules, with a focus on thermally induced delamination and cracking of solder joints in power semiconductor modules, which are frequent causes of failure. Innovative approaches are being researched, such as the use of the piezoelectric properties of SiC and GaN semiconductors as actuators and sensors as well as the analysis of scattering parameters (S-parameters) to detect signs of ageing. The aim is to evaluate the suitability of these methods through simulations and laboratory tests and to create an engineering basis for more precise service life predictions in power electronics.

The research project combines physics and artificial intelligence by integrating neural networks directly into the Lattice Boltzmann Method (LBM) - an established method for the simulation of complex flows. A key result is the Python framework "Lettuce", which was developed as part of the doctorate. This uses PyTorch for GPU acceleration of simulations and enables the seamless integration of machine learning algorithms.

PhD student: Sanjana Rajasekar This PhD thesis analyses the role of social capital and social protection of smallholder livestock farmers in Gujarat, India, for food security. Smallholder farmers in the agricultural sector have been affected during the COVID-19 pandemic due to their marginality and the slow adaptation of formal social protection to the crisis.

Using the city of Sao Paulo as an example, doctoral student Silvia Berenice Fischer assesses the vulnerability of urban and peri-urban agriculture to extreme weather events and current adaptation strategies from a socio-ecological perspective.

In Germany, motorised private transport continues to dominate, although private vehicles remain unused for an average of 23 hours a day and there is a strong dependency, particularly in rural areas, due to a lack of alternatives. In his doctoral thesis, Paul Bossauer is investigating how new technologies such as blockchain can help to strengthen mobility services in rural areas and promote shared vehicle use.

PhD student Andrew Boogaards has been working with indigenous communities in southern Guyana to explore the different livelihood strategies that local indigenous peoples are adopting to reconcile their traditional practices with market-based activities, particularly during a global pandemic.