@misc{DornischSchradeXuetal., author = {Dornisch, Wolfgang and Schrade, David and Xu, Bai-Xiang and M{\"u}ller, Ralf}, title = {Coupling of phase field models for ferroelectric and ferromagnetic layers in multiferroic heterostructures}, series = {VII International Conference on Coupled Problems in Science and Engineering (Coupled Problems 2017)}, journal = {VII International Conference on Coupled Problems in Science and Engineering (Coupled Problems 2017)}, publisher = {CIMNE}, address = {Barcelona}, pages = {1}, abstract = {Heterostructures of ferroelectric and ferromagnetic layers are commonly used to obtain electromagnetic effects. The elastic coupling between the layers is widely acknowledged as the main mechanism responsible for the electro-magneto interaction. Within this contribution we study the coupling of ferroelectric and ferromagnetic layers with well-defined interfaces. The intention is to simulate the switching of the magnetization with the help of electric fields, which has been studied experimentally in [1]. Each layer is simulated by using mechanically coupled phase field modeling, whereby the approaches presented in [2] and [3] will be used. The strains in each layer depend on the direction of the polarization/magnetization. A mismatch of these strains will be compensated by local deformations at the interface as the coupling results from the coherent deformation at the interface. This leads to the possibility to alter the magnetization direction by changing the electric polarization and vice verse. Numerical simulations will illustrate the evolution of the ferroic microstructures with a focus on the strain coupling and the resulting interactions between layers.}, language = {en} } @misc{DornischMueller, author = {Dornisch, Wolfgang and M{\"u}ller, Ralf}, title = {Phase field modelling of ferroelectric-ferromagnetic interfaces}, series = {Proceedings of the Third Seminar on The Mechanics of Multifunctional Materials : Physikzentrum Bad Honnef June 11 - 15, 2018}, journal = {Proceedings of the Third Seminar on The Mechanics of Multifunctional Materials : Physikzentrum Bad Honnef June 11 - 15, 2018}, editor = {Schr{\"o}der, J{\"o}rg and Lupascu, Doru C. and Wende, Heiko and Brands, Dominik}, publisher = {Universit{\"a}t Duisburg-Essen}, address = {Essen}, isbn = {3-9818074-4-8}, doi = {10.17185/duepublico/46481}, url = {http://nbn-resolving.de/urn:nbn:de:hbz:464-20180702-085433-3}, pages = {93 -- 96}, abstract = {Magneto-electric coupling along interfaces between ferroelectric and ferromagneticmaterials allows the magnetization in ferromagnetic layers to be controlled by electrical fields.The coupling effect is mainly due to the deformation coupling between the layers. Thus, furthercoupling effects at the interfaces are neglected in this contribution. Phase field formulationsare used to model the polarization and magnetization in the ferroelectric and ferromagneticlayers, respectively. A coupling between the phase field and the strains is introduced in eachlayer in combination with a mechanical coupling at the interface. The numerical formulationfor the ferroelectric layer is taken from literature. A special focus is set on the discretization ofthe length-constrained order parameter in the ferromagnetic layer. We show a new approachto enforce this constraint and provide a numerical simulation which illustrates the magneto-electric coupling effect.}, language = {en} } @misc{DornischSchradeWolfetal., author = {Dornisch, Wolfgang and Schrade, David and Wolf, Jana and M{\"u}ller, Ralf}, title = {Numerical methods for the modeling of the magnetization vector in multiferroic heterostructures}, series = {Proceedings in Applied Mathematics and Mechanics, Special Issue: 88th Annual Meeting of the International Association of Applied Mathematics and Mechanics (GAMM), Weimar 2017)}, volume = {17}, journal = {Proceedings in Applied Mathematics and Mechanics, Special Issue: 88th Annual Meeting of the International Association of Applied Mathematics and Mechanics (GAMM), Weimar 2017)}, number = {1}, publisher = {WILEY-VCH Verlag GmbH \& Co. KGaA}, address = {Weinheim}, issn = {1617-7061}, doi = {10.1002/pamm.201710221}, pages = {503 -- 504}, abstract = {Multiferroic heterostructures are commonly used to obtain electro-magnetic coupling effects. Thereby, the ferroelectric layer is used to control the magnetization in the ferromagnetic layer. The coupling between the layers is obtained by the mechanical coupling between the layers, which have well-defined interfaces. Within this contribution we use phase field models to define the polarization and magnetization in the ferroelectric and ferromagnetic layers, respectively. A coupling between polarization/magnetization and strains in each layer in combination with coherent deformations at the interface yields an electromagnetic coupling within the entire heterostructure. Numerical formulations for the interpolation of the polarization vector are well-defined in the literature. However, the establishment of a consistent numerical formulation for the ferromagnetic layer, where the length of the magnetization vector has to be constant, remains a difficult task. We propose a new numerical approach for the consistent treatment of the ferromagnetic layer and provide numerical simulations which illustrate the electromagnetic coupling effect.}, language = {en} } @misc{SchmidtAmmarDornischetal., author = {Schmidt, Simon David and Ammar, Kais and Dornisch, Wolfgang and Forest, Samuel and M{\"u}ller, Ralf}, title = {Phase field model for the martensitic transformation: comparison of the Voigt/Taylor and Khachaturyan approach}, series = {Continuum Mechanics and Thermodynamics}, volume = {33}, journal = {Continuum Mechanics and Thermodynamics}, number = {5}, issn = {0935-1175}, doi = {10.1007/s00161-021-01007-1}, pages = {2075 -- 2094}, language = {en} } @misc{AnderiesCummingClementsetal., author = {Anderies, John M. and Cumming, Graeme S. and Clements, Hayley S. and Lade, Steven J. and Seppelt, Ralf and Chawla, Sivee and M{\"u}ller, Birgit}, title = {A framework for conceptualizing and modeling social-ecological systems for conservation research}, series = {Biological Conservation}, volume = {275}, journal = {Biological Conservation}, publisher = {Elsevier BV}, issn = {0006-3207}, doi = {10.1016/j.biocon.2022.109769}, pages = {13}, language = {en} } @misc{AubeleGrillEggertetal., author = {Aubele, Maria and Grill, Eva and Eggert, Thomas and Schneider, Erich and Strobl, Ralf and Jahn, Klaus and M{\"u}ller, Martin and Holle, Rolf and Linkohr, Birgit and Heier, Margit and Ladwig, Karl-Heinz and Lehnen, Nadine}, title = {Symptoms in unilatral vestibular hypofunction are associated with number of catch-up saccades and retinal errors: results from the population-based KORA FF4study}, series = {Frontiers in Neurology}, volume = {2023}, journal = {Frontiers in Neurology}, number = {14}, issn = {1664-2295}, pages = {8}, abstract = {Objective: The presence and intensity of symptoms vary in patients with unilateral vestibular hypofunction. We aimed to determine which saccadic and vestibulo-ocular reflex parameters best predict the presence of symptoms in unilateral vestibular hypofunction in order to better understand vestibular compensation and its implications for rehabilitation therapy. Methods: Video head impulse test data were analyzed from a subpopulation of 23 symptomatic and 10 currently symptom-free participants with unilateral vestibular hypofunction, embedded in the KORA (Cooperative Health Research in the Region of Augsburg) FF4 study, the second follow-up of the KORA S4 population-based health survey (2,279 participants). Results: A higher number of catch-up saccades, a higher percentage of covert saccades, and a larger retinal error at 200 ms after the onset of the head impulse were associated with relevant symptoms in participants with unilateral vestibular hypofunction (p = 0.028, p = 0.046, and p = 0.038, respectively). After stepwise selection, the number of catch-up saccades and retinal error at 200 ms remained in the final logistic regression model, which was significantly better than a null model (p = 0.014). Age, gender, saccade amplitude, saccade latency, and VOR gain were not predictive of the presence of symptoms. Conclusion: The accuracy of saccadic compensation seems to be crucial for the presence of symptoms in unilateral vestibular hypofunction, highlighting the role of specific gaze stabilization exercises in rehabilitation. Early saccades, mainly triggered by the vestibular system, do not seem to compensate accurately enough, resulting in a relevant retinal error and the need for more as well as more accurate catch-up saccades, probably triggered by the visual system.}, language = {en} } @book{HoffmannAndersFischeretal., author = {Hoffmann, Melanie and Anders, Kenneth and Fischer, Lars and B{\"o}llmann, J{\"o}rg and Br{\"u}ckner, Ardo and Brunk, Ingo and Donath, Helmut and Donat, Ralf and Elmer, Michael and G{\"u}th, Mareike and H{\"a}ußler, Robert and Mrzljak, Jadranka and Mudra, Dieter and M{\"u}ller, Markus and Peschel, Tim and Pilz, Wilfried and Sawade, Wolfgang and Schonert, P. and Siedschlag, Marina and Siedschlag, Yvonne and Wanner, Manfred and W{\"o}llecke, Jens}, title = {Kolonisten gesucht! Steckbriefe nat{\"u}rlicher und sozialer Besiedler der Bergbaufolgelandschaft Schlabendorfer Felder}, editor = {Hoffmann, Melanie and Anders, Kenneth and Fischer, Lars}, publisher = {B{\"u}ro f{\"u}r Landschaftskommunikation}, address = {Bad Freienwalde}, pages = {52}, language = {de} } @misc{DreyerMuellerBernascheketal., author = {Dreyer, Christian and M{\"u}ller, Vivian C. and Bernaschek, Andreas and Frahm, Mike and Jankowski, Benjamin and Elagroudy, Youssef and Koppusch, Klarissa and Fiedler, Tom and Eckert, Angelika and Tatai, Tiberiu Mihai and Borges, Ralf and Behrendt, Felix and Fricke, Anna and Schreiner, Monika and Seidlitz, Holger}, title = {Functional integration of photonic components for (vertical) urban farming}, series = {Photonic Technologies in Plant and Agricultural Science III}, journal = {Photonic Technologies in Plant and Agricultural Science III}, editor = {Heinemann, Dag and Polder, Gerrit}, publisher = {SPIE}, address = {Bellingham, WA}, issn = {277-786X}, doi = {10.1117/12.3081069}, abstract = {The project Food4Future (F4F) is a long-term initiative funded by the German government. The decade-long project aims to develop groundbreaking ideas for urban farming, along with the corresponding materials, technologies and processes. It considers various future scenarios such as the collapse of global supply chains ("no trade") and a severe shortage of arable land ("no land"). Different strategies for cultivating organisms such as crickets, jellyfish, halophytes and algae in an urban environment are being developed. New modular cultivation compartments have been constructed and built which can be used as stand-alone units or in a paternoster (continuous loop) system. An overview is given on the functional integration of SMD-LEDs, ranging from large planar flat units for halophyte cultivation to salt water-resistant UV-LED light sabers for algae cultivation and LEDs integrated directly into transparent composites.}, language = {en} }