Minimum-weight springs

Load deflection curves for minimum weight spring

Thermodynamical description of heavy ion collisions

We analyze the thermodynamical state of nuclear matter in transport descriptions of heavy ion reactions. We determine thermodynamical variables from an analysis of local momentum space distributions and compare to blast model parameters from an analysis of fragment energy spectra. These descriptions are applied to spectator and fireball matter in semi-central and central Au+Au collisions at SIS-energies, respectively.Comment: 4 pages, 2 postscript-figures, to be published in the proceedings of Bologna2000: Structure of the Nucleus at the Dawn of the Century, Bologna, Italy, 29 May - 3 Jun 200

Testing Dirac-Brueckner models in collective flow of heavy-ion collisions

We investigate differential in-plane and out-of-plane flow observables in heavy ion reactions at intermediate energies from $0.2\div 2$ AGeV within the framework of relativistic BUU transport calculations. The mean field is based on microscopic Dirac-Brueckner-Hartree-Fock (DBHF) calculations. We apply two different sets of DBHF predictions, those of ter Haar and Malfliet and more recent ones from the T\"ubingen group, which are similar in general but differ in details. The latter DBHF calculations exclude spurious contributions from the negative energy sector to the mean field which results in a slightly softer equation of state and a less repulsive momentum dependence of the nucleon-nucleus potential at high densities and high momenta. For the application to heavy ion collisions in both cases non-equilibrium features of the phase space are taken into account on the level of the effective interaction. The systematic comparison to experimental data favours the less repulsive and softer model. Relative to non-relativistic approaches one obtains larger values of the effective nucleon mass. This produces a sufficient amount of repulsion to describe the differential flow data reasonably well.Comment: 14 pages Revtex, 19 figures, discussion extended and two figures added, accepted for publication in EPJ

Computational characterization and prediction of metal-organic framework properties

In this introductory review, we give an overview of the computational chemistry methods commonly used in the field of metal-organic frameworks (MOFs), to describe or predict the structures themselves and characterize their various properties, either at the quantum chemical level or through classical molecular simulation. We discuss the methods for the prediction of crystal structures, geometrical properties and large-scale screening of hypothetical MOFs, as well as their thermal and mechanical properties. A separate section deals with the simulation of adsorption of fluids and fluid mixtures in MOFs