Control Strategies for Highly Gyroscopic Outer Rotors with Diametral Enlargement in Active Magnetic Bearings

Flywheels are used for peak shaving or load smoothing to generate a higher efficiency and a more stable power supply. Therefore, this paper investigates highly integrated outer rotor flywheels levitated by active magnetic bearings (AMB). Due to the highly gyroscopic behavior and the diametrical enlargement under rotation, the system behavior changes with the speed, leading to a significant decrease in the maximum force and maximum force slew rate of the AMB. Thus, the speed range in which a decentralized feedback control stabilizes the system is reduced. In the literature, there are numerous approaches for coping with gyroscopic behavior. However, there are far fewer investigations for explicit consideration of the change in the air gap in the control structure. Therefore, the goal of this work is to find a control strategy to reduce the effect of the gyroscopic behavior as well as the change of the air gap. The authors propose a control strategy combining a cross feedback control with a decentralized variable feedback control. With this combination, the drawbacks of the previously described effects are compensated, leading to a higher operating range of the system and a reduced utilization of the amplifier without overcompensation at lower rotational speeds

Intracellular Dynamics of Extracellular Vesicles by Segmented Trajectory Analysis

The analysis of nanoparticle (NP) dynamics in live cell studies by video tracking provides detailed information on their interactions and trafficking in the cells. Although the video analysis is not yet routinely used in NP studies, the equipment suitable for the experiments is already available in most laboratories. Here, we compare trajectory patterns, diffusion coefficients, and particle velocities of NPs in A549 cells with a rather simple experimental setup consisting of a fluorescence microscope and openly available trajectory analysis software. The studied NPs include commercial fluorescent polymeric particles and two subpopulations of PC-3 cell-derived extracellular vesicles (EVs). As bioderived natural nanoparticles, the fluorescence intensities of the EVs limited the recording speed. Therefore, we studied the effect of the recording frame rate and analysis parameters to the trajectory results with bright fluorescent commercial NPs. We show that the trajectory classification and the apparent particle velocities are affected by the recording frame rate, while the diffusion constants stay comparable. The NP trajectory patterns were similar for all NP types and resembled intracellular vesicular transport. Interestingly, the EV movements were faster than the commercial NPs, which contrasts with their physical sizes and may indicate a greater role of the motor proteins in their intracellular transports.Peer reviewe

Inhabitants of interesting subsets of the Bousfield lattice

In 1979, Bousfield defined an equivalence relation on the stable homotopy category. The set of Bousfield classes has some important subsets such as the distributive lattice DL of all classes 〈E〉which are smash idempotent and the complete Boolean algebra cBA of closed classes. We provide examples of spectra that are in DL, but not in cBA; in particular, for every prime p, the Bousfield class of the Eilenberg–MacLane spectrum 〈HFp〉 is in DL∖cBA

Führungsverantwortung in der Hochschullehre : Zur Situation in den MINT-Fächern und Wirtschaftswissenschaften an Universitäten in Baden-Württemberg, Rheinland-Pfalz und Thüringen

Manche Studierende sind die Chefs von morgen. Sie müssen Unternehmensziele erreichen und Gewinn erwirtschaften. Gleichzeitig führen sie Mitarbeiter und Mitarbeiterinnen und müssen ihrer Verantwortung gerecht werden. Doch Universitäten bereiten kaum auf eine spätere Führungsverantwortung vor, das ist eines der zentralen Ergebnisse der empirischen Studie „Führungsethik als Ethik in den Wissenschaften“. An der von der Carl-Zeiss-Stiftung geförderten Studie waren die Universitäten Tübingen, Mainz und Jena beteiligt. Gut eineinhalb Jahre lang forschten Wissenschaftlerinnen und Wissenschaftler aus Philosophie, Politikwissenschaft, Soziologie und Wirtschaftswissenschaft gemeinsam zur Frage: Inwiefern bereiten Universitäten ihre Studierenden im Rahmen eines Fachstudiums auf spätere Führungsverantwortung vor? Untersucht wurden über 600 mathematisch-naturwissenschaftliche, ingenieurwissenschaftliche und wirtschaftswissenschaftliche Bachelor- und Master-Studiengänge. Interviews mit Expert_innen aus dem Hochschulbereich ergänzten die Untersuchung. Auch Führungskräfte aus der freien Wirtschaft brachten ihre Expertise ein

Topical Review on "Beta-beams"

Neutrino physics is traversing an exciting period, after the important discovery that neutrinos are massive particles, that has implications from high-energy physics to cosmology. A new method for the production of intense and pure neutrino beams has been proposed recently: the ``beta-beam''. It exploits boosted radioactive ions decaying through beta-decay. This novel concept has been the starting point for a new possible future facility. Its main goal is to address the crucial issue of the existence of CP violation in the lepton sector. Here we review the status and the recent developments with beta-beams. We discuss the original, the medium and high-energy scenarios as well as mono-chromatic neutrino beams produced through ion electron-capture. The issue of the degeneracies is mentioned. An overview of low energy beta-beams is also presented. These beams can be used to perform experiments of interest for nuclear structure, for the study of fundamental interactions and for nuclear astrophysics.Comment: Topical Review for Journal of Physics G: Nuclear and Particle Physics, published version, minor corrections, references adde

Epigenetic dynamics of monocyte-to-macrophage differentiation

Background Monocyte-to-macrophage differentiation involves major biochemical and structural changes. In order to elucidate the role of gene regulatory changes during this process, we used high-throughput sequencing to analyze the complete transcriptome and epigenome of human monocytes that were differentiated in vitro by addition of colony-stimulating factor 1 in serum-free medium. Results Numerous mRNAs and miRNAs were significantly up- or down-regulated. More than 100 discrete DNA regions, most often far away from transcription start sites, were rapidly demethylated by the ten eleven translocation enzymes, became nucleosome-free and gained histone marks indicative of active enhancers. These regions were unique for macrophages and associated with genes involved in the regulation of the actin cytoskeleton, phagocytosis and innate immune response. Conclusions In summary, we have discovered a phagocytic gene network that is repressed by DNA methylation in monocytes and rapidly de-repressed after the onset of macrophage differentiation