Computational analysis of the flowfield of a two-dimensional ejector nozzle

A time-iterative full Navier-Stokes code, PARC, is used to analyze the flowfield of a two-dimensional ejector nozzle system. A parametric study was performed for two controlling parameters, duct to nozzle area ratio and nozzle pressure ratio. Results show that there is an optimum area ratio for the efficient pumping of secondary flow. At high area ratios, a freestream flow passes directly through the mixing duct without giving adequate pumping. At low area ratios, the jet boundary blocks the incoming flow. The nozzle pressure ratio variation shows that the pumping rate increases as the pressure ratio increases, provided there is no interaction between the shroud wall and the shock cell structure

Policy compass: FCM-based policy impact evaluation using public open data

This paper presents how Fuzzy Cognitive Map (FCM) technique can be applied by a policy maker to support the policy impact evaluation using the example of Policy Compass, an EU research project. The practical usage example on interest rate policy shows the potential of FCMs as a policy impact modelling tool. Through the provision of a more intuitive and easier means of using open data based on FCM techniques, the Policy Compass project can play a critical role for both policy maker and lay public to evaluate the policy impact and prepare for future policy making

Defect Motion and Lattice Pinning Barrier in Josephson-Junction Ladders

We study motion of domain wall defects in a fully frustrated Josephson-unction ladder system, driven by small applied currents. For small system sizes, the energy barrier E_B to the defect motion is computed analytically via symmetry and topological considerations. More generally, we perform numerical simulations directly on the equations of motion, based on the resistively-shunted junction model, to study the dynamics of defects, varying the system size. Coherent motion of domain walls is observed for large system sizes. In the thermodynamical limit, we find E_B=0.1827 in units of the Josephson coupling energy.Comment: 7 pages, and to apear in Phys. Rev.

Speculations on Isolated Lepton Events at HERA

Speculations on mechanisms which might be responsible for events with an isolated high p_T lepton, a hadron jet and missing energy, as observed in the H1 experiment at HERA, are discussed.Comment: LaTeX, 6 pages, 2 figures, presented at the XXXI Conference of Theoretical Physics "Matter to the Deepest", Ustron, Poland, September 5-11, 200