Refine
Department, Institute
- Fachbereich Elektrotechnik, Maschinenbau, Technikjournalismus (65)
- Institut für Technik, Ressourcenschonung und Energieeffizienz (TREE) (58)
- Fachbereich Informatik (17)
- Institute of Visual Computing (IVC) (4)
- Institut für funktionale Gen-Analytik (IFGA) (3)
- Zentrum für Innovation und Entwicklung in der Lehre (ZIEL) (2)
- Fachbereich Angewandte Naturwissenschaften (1)
- Fachbereich Wirtschaftswissenschaften (1)
Document Type
- Article (59)
- Conference Object (24)
- Part of a Book (5)
- Preprint (5)
- Report (4)
- Contribution to a Periodical (1)
- Doctoral Thesis (1)
- Other (1)
Year of publication
Keywords
- Molecular dynamics (4)
- Force field (3)
- Numerical optimization (3)
- Extrusion blow molding (2)
- High-performance computing (2)
- Lennard-Jones potential (2)
- Molecular modeling (2)
- Molecular simulation (2)
- Monte Carlo (2)
- Semi-Lagrangian (2)
The influence of interaction details on the thermal diffusion in binary Lennard-Jones liquids
(2001)
There exists a disturbing controversy in the literature about the sign of the Soret effect in binary mixtures of modelfluids (Lennard-Jones atoms), whose components differ only in their molecular diameter. For such mixtures, the dependence of the Soret coefficient on the state (liquid versus supercritical), on the system size and on details of handling the range and the cutoff of the Lennard-Jones potential is examined by molecular-dynamics simulations. We establish unambiguously the direction of the Soret effect: Under all circumstances investigated, large particles are driven to the hot region. At supercritical densities, the Soret effect is considerably smaller than in the dense liquid and, furthermore, details of the attractive tail of the Lennard-Jones potential become much more important.
Comparison Between Coarse-Graining Models for Polymer Systems: Two Mapping Schemes for Polystyrene
(2007)
In this contribution we briefly recap the general concept of the BRSU Race Academy. We then concentrate on and demonstrate how practical projects can be set up and executed within this framework. We discuss what is needed to train the members of the Race Academy properly and how the faculty advisor could change his course of action during the projects. The feedback and the results of such projects have been extremely positive so far: The Race Academy members have been perceived as role models to their peers, and an efficient peer-group atmosphere could be set up that facilitated learning. With their experience, solid user knowledge and the close contact to several industrial partners, a productive, authentic and practical working atmosphere has been established. We will give examples of how to use our new teaching approach to surpass the qualities of classes held in the traditional way. Furthermore, it is shown that the technical understanding is improved, as well as the personal experience to work with and integrate into a professional team.
Formula Student is known worldwide as a design contest for engineering students, in which they train technical skills and engineering thinking by developing and manufacturing a single-seated race car every year. The efficient transfer of highly specialized and professional knowledge about physics and manufacturing has to be ensured every year, as the members turn into alumni. This requires much more than only technical skills.
In this contribution, we want to present how the Bonn-Rhine-Sieg University of Applied Sciences supports its Formula Student team in order to foster and exploit its great potentials with a systematic approach, under the supervision of its team faculty advisor. We show how senior students learn how to teach their fellow students in their highly specialized skills in a so called “Race Academy”. This aims at the evolution of teaching content, and the art of teaching itself, by systematically involving peers in the teaching process.
Ressourceneffiziente Optimierung von Hohlkörpern aus Kunststoff mittels Multiskalensimulation
(2017)
Aufgrund der weltweiten Bemühungen, den CO2- und Schadstoffausstoß zu reduzieren, sind die Automobilhersteller veranlasst, die Entwicklung effizienter Fahrzeuge verstärkt voranzutreiben. Die gestiegenen Anforderungen machen sich besonders an den Entwicklungstrends der letzten Jahre bemerkbar. Neben Maßnahmen, um den Kraftstoffverbrauch konventioneller Fahrzeuge zu reduzieren, wie z.B. Downsizing, Start/Stopp-Automatiken oder Disconnect-Systemen bei Allradfahrzeugen, gewannen elektrifizierte Fahrzeugkonzepte wie Hybrid- und Elektrofahrzeuge stark an Bedeutung.
This work addresses the question of whether it is possible to define simple pairwise interaction terms to approximate free energies of proteins or polymers. Rather than ask how reliable a potential of mean force is, one can ask how reliable it could possibly be. In a two-dimensional, infinite lattice model system one can calculate exact free energies by exhaustive enumeration. A series of approximations were fitted to exact results to assess the feasibility and utility of pairwise free energy terms. Approximating the true free energy with pairwise interactions gives a poor fit with little transferability between systems of different size. Adding extra artificial terms to the approximation yields better fits, but does not improve the ability to generalize from one system size to another. Furthermore, one cannot distinguish folding from nonfolding sequences via the approximated free energies. Most usefully, the methodology shows how one can assess the utility of various terms in lattice protein/polymer models.
Structural and Dynamical Properties of Polystyrene Determined by Coarse-Graining MD Simulations
(2007)
We present results from a detailed study of a new, optimized coarse-grained (CG) model of polystyrene (PS) and compare it with a recently published one (Harmandaris et al., Macromolecules 2006, 39, 6708). We will explain in detail, what led us to a different mapping scheme and put that into the general framework, with special emphasis on the aspect of time mapping. The new model is tested against the structural and dynamic properties of PS, resulting from atomistic simulations.
The paper describes methods for calculating chemical equilibria based on a constrained Gibbs free energy minimization. The methods allow the treatment of multicomponent systems with multiple phases, including gaseous phases, condensed phases, and stoichiometric phases. A special aspect is the detection and treatment of miscibility gaps. The underlying mathematical problem is described in detail together with the algorithmic approach for its solution. Results are presented for some test cases, including the computation of phase diagrams for ternary systems.
