TY - JOUR A1 - Stannarius, Ralf A1 - Harth, Kirsten T1 - The structure of disintegrating defect clusters in smectic C freely suspended films JF - Soft Matter N2 - Disclinations or disclination clusters in smectic C freely suspended films with topological charges larger than one are unstable. They disintegrate, preferably in a spatially symmetric fashion, into single defects with individual charges of +1, which is the smallest positive topological charge allowed in polar vector fields. While the opposite process of defect annihilation is well-defined by the initial defect positions, disintegration starts from a singular state and the following scenario including the emerging regular defect patterns must be selected by specific mechanisms. We analyze experimental data and compare them with a simple model where the defect clusters adiabatically pass quasi-equilibrium solutions in one-constant approximation. It is found that the defects arrange in geometrical patterns that correspond very closely to superimposed singular defect solutions, without additional director distortions. The patterns expand by affine transformations where all distances between individual defects scale with the same time-dependent scaling factor proportional to the square-root of time. Y1 - 2023 UR - https://pubs.rsc.org/en/content/articlelanding/2023/sm/d3sm00808h U6 - https://doi.org/https://doi.org/10.1039/d3sm00808h IS - 19 SP - 6109 EP - 6115 PB - Royal Society of Chemistry ER - TY - JOUR A1 - Klopp, Christoph A1 - Trittel, Torsten A1 - Harth, Kirsten A1 - Stannarius, Ralf T1 - Coalescence of biphasic droplets embedded in free standing smectic A films JF - Soft Matter N2 - We investigate micrometer-sized flat droplets consisting of an isotropic core surrounded by a nematic rim in freely suspended smectic A liquid-crystal films. In contrast to purely isotropic droplets which are characterized by a sharp edge and no long-range interactions, the nematic fringe introduces a continuous film thickness change resulting in long-range mutual attraction of droplets. The coalescence scenario is divided in two phases. The first one consists in the fusion of the nematic regions. The second phase involves the dissolution of a thin nematic film between the two isotropic cores. The latter has many similarities with the rupture of thin liquid films between droplets coalescing in an immiscible viscous liquid. Coalescence of biphasic droplets in free-standing smectic films is controlled in part by the rupture of a thin nematic membrane separating the isotropic droplet cores. Y1 - 2023 UR - https://pubs.rsc.org/en/content/articlelanding/2024/sm/d3sm01549a U6 - https://doi.org/10.1039/d3sm01549a SN - 1744-683X VL - 20 IS - 5 SP - 1036 EP - 1046 PB - Royal Society of Chemistry ER - TY - JOUR A1 - Vogel, Sven A1 - Wölfer, Christian A1 - Ramirez-Diaz, Diego A1 - Flassig, Robert A1 - Sundmacher, Kai A1 - Schwille, Petra T1 - Symmetry Breaking and Emergence of Directional Flows in Minimal Actomyosin Cortices JF - Cells N2 - Cortical actomyosin flows, among other mechanisms, scale up spontaneous symmetry breaking and thus play pivotal roles in cell differentiation, division, and motility. According to many model systems, myosin motor-induced local contractions of initially isotropic actomyosin cortices are nucleation points for generating cortical flows. However, the positive feedback mechanisms by which spontaneous contractions can be amplified towards large-scale directed flows remain mostly speculative. To investigate such a process on spherical surfaces, we reconstituted and confined initially isotropic minimal actomyosin cortices to the interfaces of emulsion droplets. The presence of ATP leads to myosin-induced local contractions that self-organize and amplify into directed large-scale actomyosin flows. By combining our experiments with theory, we found that the feedback mechanism leading to a coordinated directional motion of actomyosin clusters can be described as asymmetric cluster vibrations, caused by intrinsic non-isotropic ATP consumption with spatial confinement. We identified fingerprints of vibrational states as the basis of directed motions by tracking individual actomyosin clusters. These vibrations may represent a generic key driver of directed actomyosin flows under spatial confinement in vitro and in living systems. Y1 - 2020 UR - https://www.mdpi.com/2073-4409/9/6/1432 U6 - https://doi.org/10.3390/cells9061432 SP - 1 EP - 10 PB - MDPI ER - TY - JOUR A1 - Goschin, Tobias A1 - Vogel, Mathias A1 - Flassig, Robert T1 - Energy Technologies For Decarbonizing The Steel Processing Industry – A Numerical Study JF - IFAC-PapersOnLine N2 - This study analyzes approaches to decarbonize the energy supply of the secondary steel processing industry. Therefore, real data from a secondary steel production company is used in combination with state-of-the art low carbon energy supply technologies. Also, the use of waste heat from a pusher furnace for process integration is considered. The developed temporal process model allows holistic optimizing and expanding the steel making process system regarding techno-economic criteria. As we show, implementing the annual heat demand of a municipality shows that a nearly 100 % self-sufficient heat supply is possible. Y1 - 2022 UR - https://linkinghub.elsevier.com/retrieve/pii/S240589632200386X U6 - https://doi.org/https://doi.org/10.1016/j.ifacol.2022.07.001 VL - 55 IS - 9 SP - 1 EP - 5 PB - Elsevier ER - TY - CHAP A1 - Vogel, Mathias A1 - Goschin, Tobias A1 - Flassig, Robert T1 - Techno-economic analysis of excess wind energy utilization in the energy supply of residential quarters T2 - Konferenz: Symposium on Control of Power and Energy Systems (CPES), 2022/ Konferenzband:11th IFAC Symposium on Control of Power and Energy Systems (CPES 2022) Y1 - 2022 U6 - https://doi.org/10.32479/ijeep.8067 PB - Elsevier ER - TY - JOUR A1 - Trittel, Torsten A1 - Klopp, Christoph A1 - Harth, Kirsten A1 - Stannarius, Ralf T1 - Stability and Rupture of Liquid Crystal Bridges under Microgravity JF - Crystals KW - smectic liquid-crystals KW - Rayleigh-Plateau instability KW - TEXUS suborbital rocket KW - microgravity Y1 - 2022 U6 - https://doi.org/https://doi.org/10.3390/cryst12081092 VL - 12 IS - 8 PB - MDPI ER - TY - BOOK A1 - Kraska, Martin T1 - Engineering Calculations with SMath BT - First Steps N2 - Introduction to SMath Studio covering the topics installation, configuration, creating text and formulas, scientific units, graphics, embedded images. The tutorial takes approximately 2 hours to complete. KW - SMath KW - Software Y1 - 2025 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:522-opus4-33709 PB - Technische Hochschule Brandenburg CY - Brandenburg an der Havel ER - TY - CHAP A1 - Sigwarth, Timo A1 - Löwe, Katharina A1 - Beck, Eberhard A1 - Pelchen, Lutz A1 - Schrader, Thomas T1 - Conceptual ontology of prospective risk analysis in medical environments - the OPT-Model-Ontology T2 - 2015 IEEE Seventh International Conference on Intelligent Computing and Information Systems (ICICIS'15) : Faculty of Commuter & Information Sciences, Ain Shams University, Cairo, Egypt, 12-14 Dec. 2015 Y1 - 2015 SN - 978-1-5090-1950-2 SN - 978-1-5090-1949-6 U6 - https://doi.org/10.1109/IntelCIS.2015.7397202 SP - 88 EP - 93 PB - IEEE CY - Piscataway, NJ ER - TY - CHAP A1 - Schrader, Thomas A1 - Löwe, Katharina A1 - Pelchen, Lutz A1 - Beck, Eberhard T1 - Prospective, knowledge based clinical risk analysis: The OPT-model T2 - 2015 IEEE Seventh International Conference on Intelligent Computing and Information Systems (ICICIS) : Faculty of Commuter & Information Sciences, Ain Shams University, Cairo, Egypt, 12-14 Dec. 2015 Y1 - 2015 SN - 978-1-5090-1950-2 SN - 978-1-5090-1949-6 U6 - https://doi.org/10.1109/IntelCIS.2015.7397204 SP - 94 EP - 99 PB - IEEE CY - Piscataway, NJ ER - TY - JOUR A1 - Schumann, Sophia A1 - Stoilova, Velizara A1 - Bortoletto, Enrico A1 - Piva, Elisabetta A1 - Pacchini, Sara A1 - Mozzi, Gloria A1 - Jechow, Andreas A1 - Marion, Andrea A1 - Bertotto, Daniela A1 - Erlandson, Ann A1 - Hölker, Franz A1 - Greenberg, Larry A1 - Santovito, Gianfranco T1 - Impact of artificial light at night (ALAN) on cardiac function and acute oxidative stress physiology in migratory brown trout smolts JF - Environmental Pollution N2 - Light pollution poses significant ecological challenges for nocturnal animals reliant on natural light for migration, orientation, and circadian rhythms. The physiological effects of abrupt exposure to artificial light at night (ALAN) on migratory fish, such as the light experienced passing near illuminated infrastructures, remain poorly understood. This study investigates the physiological responses of brown trout (Salmo trutta) smolts to low-intensity (0.02 lx) and short-term (30 s) ALAN, simulating nocturnal migration light conditions near illuminated bridges. To evaluate the influence of social dynamics, trout were tested individually (solitary) or in groups of six. Using continuous cardiac monitoring with data storage tags, alongside analyses of oxidative stress markers and adenylate kinase (AK) activity in the heart, we identified distinct patterns of physiological responses. Solitary fish exhibited significant heart rate variability (HRV) increases following repeated ALAN exposure, suggesting impaired physiological regulation under repeated ALAN exposure. In contrast, trout in groups displayed consistently lower HRV over the entire 90-min experiment, implying that social dynamics likely influenced a sustained oxidative stress response, corroborated by increased AK activity. Oxidative stress markers further reflected social effects, with significant upregulation of key antioxidant enzymes (sod1, sod2, gpx1, gpx4) and elevated lipid peroxidation, identifying lipids as primary oxidative targets. The observed divergence between superoxide dismutase (SOD) activity and sod gene expression suggests adaptive post-transcriptional regulation to maintain redox balance under combined environmental and social stress. These findings reveal that social dynamics under ALAN can amplify physiological stress, potentially affecting migratory outcomes. Y1 - 2025 U6 - https://doi.org/10.1016/j.envpol.2025.126593 IS - 381 SP - 1 EP - 9 PB - Elsevier ER -