Kurt Ruth Prize winner Dr.-Ing Steven R. Lorenzen

In his dissertation, Dr.-Ing Steven R. Lorenzen dealt with methods for monitoring and extending the service life of railroad bridges with the aid of “drive-by monitoring”. Monitoring bridges with permanently installed devices is complex and costly. With “drive-by monitoring”, trains are instead equipped with sensors that can take measurements every time they cross. This allows the entire network to be monitored with just a few trains. A particular challenge here is the often short spans of the bridges combined with the high speed of the trains. Lorenzen was able to solve this problem with the help of structural dynamics and, as part of his doctorate, developed a method in which acceleration sensors attached to the train determine its resonance frequency as it crosses a bridge.

Bridges are not rigid, but structures that can move or vibrate due to their design. This free oscillation is called natural frequency. If a force with the same frequency acts on the bridge from outside – for example by a train – resonance can occur and the vibrations intensify, which in the worst case can lead to collapse. Thanks to the new method, which can now be used to determine the resonance frequencies of bridges, the dangerous “resonance crossings” can be avoided, for example by minimizing speed adjustments. This significantly increases the service life of bridges.

“In view of the poor condition of many bridges in Germany and the stresses caused by new types of trains, innovative methods for monitoring and extending the service life of these bridges are necessary and highly relevant to society,” says Professor Clemens Hübler, Head of the Institute of Structural Analysis and Design in the Department of Civil and Environmental Engineering. “What also distinguishes Steven R. Lorenzen is not just pure achievement, but the ability and desire to contribute to science and academia beyond that. In my estimation, Dr. Lorenzen will make significant contributions to the advancement of structural monitoring and structural dynamics in the future through his creativity and performance.”

Kurt Ruth Prize winner Dr. Leon Schumacher

Propylene is an important raw material for the chemical industry, for example for the production of plastics. However, its production is energy-intensive and requires the use of catalysts. The search for suitable catalysts is particularly rewarding, as the chemical reactions for popylene production are all the more efficient the more precisely the appropriate catalysts are selected. In his dissertation, Kurt Ruth Prize winner Dr. Leon Schumacher succeeded in gaining groundbreaking new scientific insights into the mode of action of catalysts in propylene production, both experimentally and theoretically. To this end, he presented new approaches that can replace the current, energy-intensive technical processes. He also identified new methods for analyzing the reaction mechanism of propylene production and used this knowledge to develop new, improved catalysts for propylene production.

“Dr. Schumacher's research results are of outstanding importance both for the targeted development of catalysts for technically relevant selective oxidations and for the fundamental development of new spectroscopic methods,” says Professor Christian Hess from the Department of Chemistry, who supervised the dissertation. Both are already attracting a great deal of attention in the scientific community, on the one hand through the numerous publications in renowned international journals, and on the other through invited lectures at international congresses. Furthermore, “it is remarkable that Leon Schumacher was able to complete an additional degree in economics alongside his Master's degree in chemistry and his doctoral thesis and successfully complete his Bachelor's degree shortly after his dissertation”.