TY - BOOK A1 - Braun, Robert A1 - Feudel, Fred A1 - Guzdar, P. T1 - The route to chaos for a two-dimensional externally driven flow : [to appear in Physical Review E] T3 - Preprint NLD Y1 - 1998 SN - 1432-2935 VL - 46 PB - Univ. Potsdam CY - Potsdam ER - TY - BOOK A1 - Braun, Robert A1 - Feudel, Fred A1 - Seehafer, Norbert T1 - Bifurcations and chaos in an array of forced vortices T3 - Preprint NLD Y1 - 1997 SN - 1432-2935 VL - 37 PB - Univ. Potsdam CY - Potsdam ER - TY - BOOK A1 - Böckmann, Christine T1 - Retrieval of multimodal aerosol size distribution by inversion of multiwavelength data T3 - Preprint NLD Y1 - 1997 SN - 1432-2935 VL - 38 PB - Univ. Potsdam CY - Potsdam ER - TY - BOOK A1 - Cramer, Marcus A1 - Eisert, Jens A1 - Illuminati, Fabrizio T1 - Inhomogeneous atomic Bose-Fermi mixtures in cubic lattices N2 - We determine the ground state properties of inhomogeneous mixtures of bosons and fermions in cubic lattices and parabolic confining potentials. For finite hopping we determine the domain boundaries between Mott-insulator plateaux and hopping-dominated regions for lattices of arbitrary dimension within mean-field and perturbation theory. The results are compared with a new numerical method that is based on a Gutzwiller variational approach for the bosons and an exact treatment for the fermions. The findings can be applied as a guideline for future experiments with trapped atomic Bose- Fermi mixtures in optical lattices Y1 - 2004 SN - 0031-9007 ER - TY - BOOK A1 - Donner, Reik Volker A1 - Cser, Adrienn A1 - Schwarz, Udo A1 - Otto, Andreas H. A1 - Feudel, Ulrike T1 - An approach to a process model of laser beam melt ablation using methods of linear and non-linear data analysis N2 - As a non-contact process laser beam melt ablation offers several advantages compared to conventional processing mechanisms. During ablation the surface of the workpiece is molten by the energy of a CO2-laser beam, this melt is then driven out by the impulse of an additional process gas. Although the idea behind laser beam melt ablation is rather simple, the process itself has a major limitation in practical applications: with increasing ablation rate surface quality of the workpiece processed declines rapidly. With different ablation rates different surface structures can be distinguished, which can be characterised by suitable surface parameters. The corresponding regimes of pattern formation are found in linear and non-linear statistical properties of the recorded process emissions as well. While the ablation rate can be represented in terms of the line-energy, this parameter does not provide sufficient information about the full behaviour of the system. The dynamics of the system is dominated by oscillations due to the laser cycle but includes some periodically driven non-linear processes as well. Upon the basis of the measured time series, a corresponding model is developed. The deeper understanding of the process can be used to develop strategies for a process control. Y1 - 2004 SN - 3-527-40430-9 ER - TY - BOOK A1 - Donner, Reik Volker A1 - Cser, Adrienn A1 - Schwarz, Udo A1 - Otto, Andreas H. A1 - Feudel, Ulrike T1 - An approach to a process model of laser beam melt ablation using methods of linear and non-linear data analysis N2 - As a non-contact process laser beam melt ablation offers several advantages compared to conventional processing mechanisms. During ablation the surface of the workpiece is molten by the energy of a CO2-laser beam, this melt is then driven out by the impulse of an additional process gas. Although the idea behind laser beam melt ablation is rather simple, the process itself has a major limitation in practical applications: with increasing ablation rate surface quality of the workpiece processed declines rapidly. With different ablation rates different surface structures can be distinguished, which can be characterised by suitable surface parameters. The corresponding regimes of pattern formation are found in linear and non-linear statistical properties of the recorded process emissions as well. While the ablation rate can be represented in terms of the line-energy, this parameter does not provide sufficient information about the full behaviour of the system. The dynamics of the system is dominated by oscillations due to the laser cycle but includes some periodically driven non-linear processes as well. Upon the basis of the measured time series, a corresponding model is developed. The deeper understanding of the process can be used to develop strategies for a process control. Y1 - 2003 SN - 3-928921-88-6 ER - TY - BOOK A1 - Engbert, Ralf T1 - Tempo-induced transitions in polyrhythmic hand movements T3 - Preprint NLD Y1 - 1997 SN - 1432-2935 VL - 41 PB - Univ. Potsdam CY - Potsdam ER - TY - BOOK A1 - Feldmeier, Achim T1 - Theoretical Fluid Dynamics T3 - Theoretical and Mathematical Physics Y1 - 2019 SN - 978-3-030-31021-9 (online) SN - 978-3-030-31023-3 (print) U6 - https://doi.org/10.1007/978-3-030-31022-6 PB - Springer CY - Cham ER - TY - BOOK A1 - Freude, Ulrike A1 - Kuznetsov, Sergey P. A1 - Pikovskij, Arkadij T1 - Strange nonchaotic attractors : dynamics between order and chaos in Quasiperiodically Forced Systems Y1 - 2006 SN - 981-256633-3 PB - World Scientific CY - Singapore ER - TY - BOOK A1 - Gutlederer, Erwin Johann T1 - On the morphology of vesicles. - [überarb. Diss.] N2 - This dissertation contains theoretical investigations on the morphology and statistical mechanics of vesicles. The shapes of homogeneous fluid vesicles and inhomogeneous vesicles with fluid and solid membrane domains are calculated. The influence of thermal fluctuations is investigated. The obtained results are valid on mesoscopic length scales and are based on a geometrical membrane model, where the vesicle membrane is described as either a static or a thermal fluctuating surface. The thesis consists of three parts. In the first part, homogeneous vesicles are considered. The focus in this part is on the thermally induced morphological transition between vesicles with prolate and oblate shape. With the help of Monte Carlo simulations, the free energy profile of these vesicles is determined. It can be shown that the shape transformation between prolate and oblate vesicles proceeds continuously and is not hampered by a free energy barrier. The second and third part deal with inhomogeneous vesicles which contain intramembrane domains. These investigations are motivated by experimental results on domain formation in single or multicomponent vesicles, where phase separation occurs and different membrane phases coexist. The resulting domains differ with regard to their membrane structure (solid, fluid). The membrane structure has a distinct effect on the form of the domain and the morphology of the vesicle. In the second part, vesicles with coexisting solid and fluid membrane domains are studied, while the third part addresses vesicles with coexisting fluid domains. The equilibrium morphology of vesicles with simple and complex domain forms, derived through minimisation of the membrane energy, is determined as a function of material parameters. The results are summarised in morphology diagrams. These diagrams show previously unknown morphological transitions between vesicles with different domain shapes. The impact of thermal fluctuations on the vesicle and the form of the domains is investigated by means of Monte Carlo simulations. N2 - Die vorliegende Arbeit enthält theoretische Untersuchungen zur Morphologie und statistischen Mechanik von Vesikeln. Es wird die Gestalt homogener fluider Vesikel und inhomogener Vesikel mit fluiden und festen Membrandomänen berechnet. Der Einfluss thermischer Fluktuationen wird untersucht. Die erzielten Ergebnisse beziehen sich auf mesoskopische Längenskalen und basieren auf einem geometrischen Membranmodell, in welchem die Vesikelmembran als statische, beziehungsweise thermisch fluktuierende Fläche beschrieben wird. Die Arbeit besteht aus drei Teilen. Im ersten Teil werden homogene fluide Vesikel betrachtet. Das Interesse gilt dem thermisch induzierten Morphologieübergang zwischen prolaten und oblaten Vesikelformen. Mit Hilfe von Monte-Carlo-Simulationen wird ein freies Energieprofil für diese Vesikel ermittelt. Es kann gezeigt werden, dass die Formumwandlung zwischen prolaten und oblaten Formen kontinuierlich verläuft und mit keiner freien Energiebarriere verbunden ist. Der zweite und dritte Teil beschäftigt sich mit inhomogenen Vesikeln, die intramembrane Domänen enthalten. Ausgangspunkt und Motivation der Berechnungen sind experimentelle Studien über Domänbildung in ein- oder mehrkomponentigen Vesikelmembranen, bei denen Phasentrennung stattfindet und unterschiedliche Membranphasen koexistieren. Die dabei auftretenden Domänen unterscheiden sich hinsichtlich ihrer Membranstruktur (fest, fluid). Diese beeinflusst die Form der Domäne und des gesamten Vesikels auf entscheidende Weise. Im zweiten Teil werden Vesikel untersucht, bei denen feste und fluide Membrandomänen koexistieren, Teil drei widmet sich Vesikeln mit zwei koexistierenden fluiden Membranphasen. In Abhängigkeit von Materialparametern werden durch Minimierung der Membranenergie die Grundzustandsformen von Vesikeln mit einfachen und komplexen Domänenformen bestimmt. Die Ergebnisse werden in Morphologiediagrammen zusammengefasst. Dabei werden bisher unbekannte Morphologieübergänge zwischen Vesikeln mit unterschiedlichen Domänformen beobachtet. Die Auswirkungen thermischer Fluktuationen auf die Vesikel und die Form ihrer Domänen werden mittels Monte-Carlo-Simulationen untersucht. KW - Vesikel KW - Membran KW - Domänen KW - vesicle KW - membrane KW - domains Y1 - 2007 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-15065 ER - TY - BOOK A1 - Heuer, Axel A1 - Hänisch, Christoph A1 - Ostermeyer, Martin A1 - Menzel, Ralf T1 - Low Power Threshold Phase Conjugating Mirrors by SBS in Yb-doped Fiber Amplifiers Y1 - 2002 ER - TY - BOOK A1 - Hinrichsen, G. A1 - Rabe, J. P. A1 - Künstler, Wolfgang ED - Gerhard, Reimund T1 - European Conference on Macromolecular Physics : molecular orientation in polymers ; generation, characterisation, application T3 - Europhysics conference abstracts Y1 - 1999 VL - 23H PB - European Physical Society CY - Geneva [u.a.] ER - TY - BOOK A1 - Holý, Václav A1 - Pietsch, Ullrich A1 - Baumbach, Tilo T1 - High-resolution x-ray scattering from thin films and multilayers T3 - Springer tracts in modern physics Y1 - 1999 SN - 3-540-62029-X U6 - https://doi.org/10.1007/BFb0109385 VL - 149 PB - Springer CY - Berlin, Heidelberg ER - TY - BOOK A1 - Kurths, Jürgen A1 - Mayer-Kress, Gottfried ED - Kantz, Holger T1 - Nonlinear analysis of physiological data Y1 - 1998 SN - 3-540-63481-9 PB - Springer CY - Berlin, New York ER - TY - BOOK A1 - Lukaschewitsch, Michael T1 - Geoelectrical conductivity problems on unbounded domains ; [submitted to SIAM Journal on Applied Mathematics] T3 - Preprint NLD Y1 - 1998 SN - 1432-2935 VL - 45 PB - Univ. Potsdam CY - Potsdam ER - TY - BOOK A1 - Mudge, Damien A1 - Ostermeyer, Martin A1 - Ottaway, D. A1 - Veitch, Peter John A1 - Munch, Jesper A1 - Hamilton, Murray T1 - High-power Nd:YAG laser using stable-unstable-resonators Y1 - 2002 ER - TY - BOOK A1 - Ostermeyer, Martin A1 - Brandenburg, Ingo T1 - Simulation of the extraction of near diffraction limited Gaussian beams from side pumped core doped ceramic Nd:YAG and conventional laser rods N2 - The application of the recently developed core doped ceramic Nd:YAG rods has the potential to provide better beam qualities compared to conventional rods since the hard aperture of the rod's boundary can be made wider while the width of the gain region remains the same. Thus, beam truncation and consequential diffraction can be reduced. We apply a finite elements model to calculate the resulting refractive index profiles in conventional and core doped rods. Propagating a Gaussian beam through both rod geometries the impact of aberrations and diffraction is compared for different side pumped scenarios. The potential advantage of the core doped geometry is discussed. (c) 2005 Optical Society of America Y1 - 2005 ER - TY - BOOK A1 - Ostermeyer, Martin A1 - Kappe, Philip A1 - Menzel, Ralf A1 - Sommer, S. A1 - Dausinger, Friedrich T1 - Laser drilling in thin materials with bursts of ns-pulses generated by stimulated Brillouin scattering (SBS) N2 - A passively Q-switched laser with a nonlinear mirror on the basis of stimulated Brillouin scattering (SBS), generates bursts of pulses with a few 10 ns pulse duration and a separation between 20-90 mu s. Percussion drilling and trepanning are performed in different materials with 1 mm thickness. The optimum parameter set of these pulse trains with regard to the burr height and ablation rate is investigated. Differences in the processing results between single pulse and multi pulse structures are discussed. In addition the laser allowed for transiently mode locked operation. Results for mode locked and merely Q-switched operation were compared Y1 - 2005 ER - TY - BOOK A1 - Ostermeyer, Martin A1 - Kappe, Philip A1 - Menzel, Ralf A1 - Wulfmeyer, Volker T1 - Diode-pumped Nd : YAG master oscillator power amplifier with high pulse energy, excellent beam quality, and frequency-stabilized master oscillator as a basis for a next-generation lidar system N2 - A pulsed, diode-laser-pumped Nd:YAG master oscillator power amplifier (MOPA) in rod geometry, frequency stabilized with a modified Pound-Drever-Hall scheme is presented. The apparatus delivers 33-ns pulses with a maximum pulse energy of 0.5 J at 1064 nm. The system was set up in two different configurations for repetition rates of 100 or 250 Hz. The beam quality was measured to be 1.5 times the diffraction limit at a pulse energy of 405 mJ and a repetition rate of 100 Hz. At 250 Hz with the same pulse energy, the M-2 was better than 2.1. The radiation is frequency converted with an efficiency of 50% to 532 nm. This MOPA system will be the pump laser of transmitters for a variety of high-end, scanning lidar systems. (C) 2005 Optical Society of America Y1 - 2005 ER - TY - BOOK A1 - Petters, Arlie O. A1 - Levine, Harold A1 - Wambsganß, Joachim T1 - Singularity theory and gravitational lensing T3 - Progress in mathematical physics Y1 - 2001 SN - 0-8176-3668-4 VL - 21 PB - Birkhäuser CY - Boston ER - TY - BOOK A1 - Pietsch, Ullrich A1 - Holý, Václav A1 - Baumbach, Tilo T1 - High resolution X-ray scattering from thin films and lateral nanostructures T3 - Advanced texts in physics : physics and astronomy online library Y1 - 2004 SN - 0-387-40092-3 PB - Springer CY - New York ET - 2. ed. ER - TY - BOOK A1 - Pikovskij, Arkadij A1 - Rosenblum, Michael A1 - Kurths, Jürgen T1 - Synchronization : a universal concept in nonlinear sciences T3 - Cambridge nonlinear science series Y1 - 2001 SN - 0-521-59285-2 VL - 12 PB - Cambridge Univ. Press CY - Cambridge ET - 1st paperback ed., repr ER - TY - BOOK A1 - Rosenblum, Michael A1 - Schäfer, Carsten A1 - Abel, Hans-Henning A1 - Kurths, Jürgen T1 - Interrelationship of Parasympathetic Innervation of the Sinoatrial Node and the Atrioventricular Node of Human Heart Y1 - 1997 SN - 1120-1797 ER - TY - BOOK A1 - Rüdiger, Günther A1 - Kitchatinov, Leonid L. A1 - Hollerbach, Rainer T1 - Magnetic processes in astrophysics : theory, simulations, experiments Y1 - 2013 SN - 978-3-527-41034-7 PB - Wiley-VCH CY - Weinheim, Bergstr. ER - TY - BOOK A1 - Rüdiger, Sten A1 - Feudel, Fred A1 - Seehafer, Norbert T1 - Dynamo bifurcations in an array of driven convectionlike rolls T3 - Preprint NLD Y1 - 1998 SN - 1432-2935 VL - 43 PB - Univ. CY - Potsdam ER - TY - BOOK A1 - Scheel, S. A1 - Seehafer, Norbert T1 - Bifurcation to Oscillations in three-dimensional Rayleigh-Bénard convection T3 - Preprint NLD Y1 - 1997 SN - 1432-2935 VL - 39 PB - Univ. Potsdam CY - Potsdam ER - TY - BOOK A1 - Schmidtmann, Olaf A1 - Feudel, Fred A1 - Seehafer, Norbert T1 - Nonlinear Galerkin methods for the 3D magnetohydrodynamic equations T3 - Preprint NLD Y1 - 1997 SN - 1432-2935 VL - 35 PB - Univ. Potsdam CY - Potsdam ER - TY - BOOK A1 - Schumacher, Jörg A1 - Kliem, Bernhard A1 - Seehafer, Norbert T1 - Three-dimensional spontaneous magnetic reconnection in neutral current sheets T3 - Preprint series / Astrophysikalisches Institut Potsdam Y1 - 1999 VL - 99,42 PB - AIP CY - Potsdam ER - TY - BOOK A1 - Seehafer, Norbert A1 - Schumacher, Jörg T1 - Resistivity profile and instability of the plane sheet pinch T3 - Preprint NLD Y1 - 1998 SN - 1432-2935 VL - 44 PB - Univ. Potsdam CY - Potsdam ER - TY - BOOK A1 - Seehafer, Norbert A1 - Schumacher, Jörg T1 - Squire's theorem for the magnetohydrodynamic sheet pinch T3 - Preprint NLD Y1 - 1997 SN - 1432-2935 VL - 40 PB - Univ. Potsdam CY - Potsdam ER - TY - BOOK A1 - Strehmel, Bernd A1 - Schrader, Sigurd A1 - Seifert, H. ED - Rettig, W. T1 - Applied fluorescence in chemistry, biology and medicine Y1 - 1999 SN - 3-540-64451-2 PB - Springer CY - Berlin ER - TY - BOOK A1 - Witt, Annette A1 - Neiman, Alexander A1 - Kurths, Jürgen T1 - Characterizing the dynamics of stochastic bistable systems by measures of complexity T3 - Preprint NLD Y1 - 1997 SN - 1432-2935 VL - 36 PB - Univ. Potsdam CY - Potsdam ER - TY - BOOK A1 - Zienicke, Egbert A1 - Seehafer, Norbert A1 - Feudel, Fred T1 - Bifurcations in two-dimensional Rayleigh-Bénard convection T3 - Preprint NLD Y1 - 1997 SN - 1432-2935 VL - 42 PB - Univ. Potsdam CY - Potsdam ER - TY - BOOK ED - Brehmer, Ludwig ED - Schrader, Sigurd ED - Wüstneck, Rainer T1 - Materials science and engineering / C Y1 - 1999 ER - TY - BOOK ED - Gerhard, Reimund T1 - Electrets : Bd. 2 Y1 - 1999 SN - 1-885540-09-4 PB - Laplacian Press CY - Morgan Hill, Calif. ET - 3. ed. ER -