A5007570932- Advanced Mathematical Modeling in Engineering
- Fluid Dynamics and Thin Films
- Nonlinear Dynamics and Pattern Formation
- Composite Material Mechanics
- Magnetic Bearings and Levitation Dynamics
- Solidification and crystal growth phenomena
- Electric Motor Design and Analysis
- Rheology and Fluid Dynamics Studies
- Resilience and Mental Health
- Grief, Bereavement, and Mental Health
- Spectral Theory in Mathematical Physics
- Theoretical and Computational Physics
- Psychological Well-being and Life Satisfaction
- Advanced Numerical Methods in Computational Mathematics
- Vibration and Dynamic Analysis
- Electric Power Systems and Control
- Numerical methods in inverse problems
- Machine Fault Diagnosis Techniques
- Fluid Dynamics and Turbulent Flows
- Navier-Stokes equation solutions
- Palliative Care and End-of-Life Issues
- Magnetic Properties and Applications
- Electromagnetic Scattering and Analysis
- Death Anxiety and Social Exclusion
- COVID-19 and Mental Health
Leibniz University Hannover
2023-2024
Lund University
2023-2024
Klinikum Rheine
2021
Düsseldorf University Hospital
2019
Heinrich Heine University Düsseldorf
2019
This study examined the role of different psychological coping mechanisms in mental and physical health during initial phases COVID-19 crisis with an emphasis on meaning-centered coping. A total 11,227 people from 30 countries across all continents participated completed measures distress (depression, stress, anxiety), loneliness, well-being, health, together problem-focused emotion-focused coping, a measure called Meaning-centered Coping Scale (MCCS) that was developed present study....
Abstract We study the homogenization of Dirichlet problem for Stokes equations in $$\mathbb {R}^3$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msup> <mml:mrow> <mml:mi>R</mml:mi> </mml:mrow> <mml:mn>3</mml:mn> </mml:msup> </mml:math> perforated by m spherical particles. assume positions and velocities particles to be identically independently distributed random variables. In critical regime, when radii are order $$m^{-1}$$ <mml:mi>m</mml:mi> <mml:mo>-</mml:mo>...
We investigate the persistence of embedded eigenvalues for a class magnetic Laplacians on an infinite cylindrical domain. The potential is assumed to be $C^2$ and asymptotically periodic along unbounded direction, with algebraic decay rate towards background potential. Under condition that eigenvalue unperturbed operator lies away from thresholds continuous spectrum, we show set nearby potentials which persists forms smooth manifold finite even codimension. proof employs tools Floquet...
Abstract Background In Germany, only limited data are available on attitudes towards death. Existing measurements complex and time consuming, psychometric properties limited. The Death Attitude Profile- Revised (DAP-R) captures dying measure consists of 32 items, which assigned to 5 dimensions (Fear Death, Avoidance, Neutral Acceptance, Approach Escape Acceptance). It has been translated tested in several countries, but no German version exists date. This study reports the translation...
We study the long-time behavior of solutions to quasilinear doubly degenerate parabolic problems fourth order. The equations model, for instance, dynamic a non-Newtonian thin-film flow on flat impermeable bottom and with zero contact angle. consider shear-rate dependent fluid rheology which is described by constitutive power law or Ellis viscosity. In all three cases, positive constants (i.e., films) are only steady-state solutions. Moreover, we can give detailed picture respect -norm. case...
Abstract We study stationary, periodic solutions to the thermocapillary thin-film model <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:msub> <mml:mi mathvariant="normal">∂</mml:mi> <mml:mi>t</mml:mi> </mml:msub> <mml:mi>h</mml:mi> <mml:mo>+</mml:mo> <mml:mi>x</mml:mi> <mml:mfenced close=")" open="("> <mml:mrow> <mml:msup> <mml:mn>3</mml:mn> </mml:msup> <mml:msubsup> </mml:msubsup> <mml:mo>−</mml:mo> <mml:mi>g</mml:mi> </mml:mrow> </mml:mfenced>...
We study the bifurcation of planar patterns and fast-moving pattern interfaces in an asymptotic long-wave model for three-dimensional B\'enard-Marangoni problem, which is close to a Turing instability. derive from full free-boundary problem thin liquid film on heated substrate low thermal conductivity via lubrication approximation. This yields quasilinear, fully coupled, mixed-order degenerate-parabolic system height temperature. As Marangoni number $M$ increases beyond critical value $M^*$,...
This paper investigates a new method for noise com-pensation in dual three-phase electrically excited synchronous machines through the use of harmonic currents, with particular focus on preventing force excitation radial and tangential mode 0. The approach field injection (HFI) is examined, an existing analytical relationship presented extended using mechanical transfer function. allows precalculation har-monic thereby reducing extensive parameter variations. HFI validated test bench,...
We study the homogenization of Dirichlet problem for Stokes equations in $\mathbb{R}^3$ perforated by $m$ spherical particles. assume positions and velocities particles to be identically independently distributed random variables. In critical regime, when radii are order $m^{-1}$, limit $u$ is given as solution Brinkman equations. provide optimal rates convergence $u_m \to u$ $L^2$, namely $m^{-\beta}$ all $\beta < 1/2$. Moreover, we consider fluctuations. central scaling, show that these...
We study the gradient-flow structure of a non-Newtonian thin film equation with power-law rheology. The is quasilinear, fourth order and doubly-degenerate parabolic. By adding singular potential to natural Dirichlet energy, we introduce modified version thin-film equation. Then, set up minimising-movement scheme that converges global positive weak solutions problem. These satisfy an energy-dissipation equality follow gradient flow. In limit vanishing singularity potential, obtain...
We study stationary, periodic solutions to the thermocapillary thin-film model \begin{equation*} \partial_t h + \partial_x \Bigl(h^3(\partial_x^3 - g\partial_x h) M\frac{h^2}{(1+h)^2}\partial_xh\Bigr) = 0,\quad t>0,\ x\in \mathbb{R}, \end{equation*} which can be derived from Bénard-Marangoni problem via a lubrication approximation. When Marangoni number $M$ increases beyond critical value $M^*$, constant solution becomes spectrally unstable (conserved) long-wave instability and stationary...
In this paper, a time-efficient approach to predict vibrations on the stator of electrical machines is extended generator rotor wind turbine. Nodal and lumped force methods projecting forces mechanical structure are discussed compared with pure FEA solution. Furthermore, node reduction technique employed at side reduce computational efforts. Finally, predicted experimental results.
We study the long-time behaviour of solutions to quasilinear doubly degenerate parabolic problems fourth order. The equations model for instance dynamic a non-Newtonian thin-film flow on flat impermeable bottom and with zero contact angle. consider shear-rate dependent fluid rheology which is described by constitutive power-law or Ellis-law viscosity. In all three cases, positive constants (i.e. films) are only steady-state solutions. Moreover, we can give detailed picture respect...