Technische Universität Darmstadt

About: Technische Universität Darmstadt is a education organization based out in Darmstadt, Germany. It is known for research contribution in the topics: Computer science & Context (language use). The organization has 17316 authors who have published 40619 publications receiving 937916 citations. The organization is also known as: Darmstadt University of Technology & University of Darmstadt.

Nanosecond formation of diamond and lonsdaleite by shock compression of graphite

Abstract: The shock-induced transition from graphite to diamond has been of great scientific and technological interest since the discovery of microscopic diamonds in remnants of explosively driven graphite. Furthermore, shock synthesis of diamond and lonsdaleite, a speculative hexagonal carbon polymorph with unique hardness, is expected to happen during violent meteor impacts. Here, we show unprecedented in situ X-ray diffraction measurements of diamond formation on nanosecond timescales by shock compression of pyrolytic as well as polycrystalline graphite to pressures from 19 GPa up to 228 GPa. While we observe the transition to diamond starting at 50 GPa for both pyrolytic and polycrystalline graphite, we also record the direct formation of lonsdaleite above 170 GPa for pyrolytic samples only. Our experiment provides new insights into the processes of the shock-induced transition from graphite to diamond and uniquely resolves the dynamics that explain the main natural occurrence of the lonsdaleite crystal structure being close to meteor impact sites.

Ecological networks are more sensitive to plant than to animal extinction under climate change

Abstract: Impacts of climate change on individual species are increasingly well documented, but we lack understanding of how these effects propagate through ecological communities. Here we combine species distribution models with ecological network analyses to test potential impacts of climate change on >700 plant and animal species in pollination and seed-dispersal networks from central Europe. We discover that animal species that interact with a low diversity of plant species have narrow climatic niches and are most vulnerable to climate change. In contrast, biotic specialization of plants is not related to climatic niche breadth and vulnerability. A simulation model incorporating different scenarios of species coextinction and capacities for partner switches shows that projected plant extinctions under climate change are more likely to trigger animal coextinctions than vice versa. This result demonstrates that impacts of climate change on biodiversity can be amplified via extinction cascades from plants to animals in ecological networks.

Tuning the Structure of Platinum Particles on Ceria In Situ for Enhancing the Catalytic Performance of Exhaust Gas Catalysts

Abstract: A dynamic structural behavior of Pt nanoparticles on the ceria surface under reducing/oxidizing conditions was found at moderate temperatures ( H2>C3H6). This dynamic nature of Pt on ceria at such low temperatures (250–500 °C) was additionally confirmed by in situ environmental transmission electron microscopy. A general concept is proposed to adjust the noble metal dispersion (size, structure), for example, during operation of an exhaust gas catalyst.

Patchy nanocapsules of poly(vinylferrocene)-based block copolymers for redox-responsive release.

Abstract: Nanocapsules composed of a poly(vinylferrocene)-block-poly(methyl methacrylate) shell and a hydrophobic liquid core are prepared in water The nanocapsule shells display a patchy structure with poly(vinylferrocene) patches with sizes of 25 ± 3 nm surrounded by poly(methyl methacrylate) The functional nanopatches can be selectively oxidized, thereby influencing the colloidal morphology and introducing polar domains in the nanocapsule shell The hydrophobic to hydrophilic transition in the redox-responsive nanopatches can be advantageously used to release a hydrophobic payload encapsulated in the core by an oxidation reaction

Serious games in prevention and rehabilitation—a new panacea for elderly people?

Abstract: Digital games cannot only be used for fun and entertainment. The term “serious games” (SG) denotes digital games serving serious purposes like education, training, advertising, research and health. Recently, a new generation of games has emerged involving whole-body movements. Compared to traditional interventions, these games may help elderly people to improve their health by enhancing physical fitness and coordinative abilities by combining increased motivation, game experience like fun and game flow and training. Serious games, particularly adventure and shooter games, already play an important role in health education, prevention and rehabilitation, e.g. to enhance health-related physical activity, improve sensory–motor coordination, prevent asthma, change nutrition behaviour and alleviate diabetes and prevent smoking or HIV. In this paper, the impact of SG on prevention and rehabilitation is discussed. Three criteria are applied. Beyond effectivity and efficiency, the additional benefits of serious games can be described and explained by different models including social, psychological, physiological and sensory–motor factors. The quality of study serves as a third criterion. Despite first promising results, there are only few high-quality studies. Adequate content, game interfaces, sustainability and appropriate settings are critical factors for the success of SG. In this regard, (sport) science can help to develop and evaluate SG and test appropriate settings that ensure sustainable use of serious games.