Volumetrische Bestimmung des Tellurs,eine maassanalytische Studie,I. Theil

Ohne Zusammenfassung     

Über die Einwirkung von Schwefelwasserstoff auf Arsensäure

Ohne Zusammenfassung     

An inverse dispersed multiphase flow model for liquid production rate determination

The aim of this study is to develop a model for the determination of the superficial velocities in horizontal and slightly inclined oil–water pipe flow conditions by using pressure gradient and mixture density information. In this article an inverse model is suggested for a dispersion of oil in water and of water in oil. This approach permits to select dispersed flow conditions from a set of experimental data, and uses a new hybrid model for the effective viscosity. A set of 310 oil–water experimental data points collected on an experimental set-up of length L = 15 m and diameter D = 8.28 cm at various (slight) orientations is used to validate the inverse method. The comparison between model reconstructions and measured flow velocities show a reasonable agreement.     

Improved lower bounds for the online bin stretching problem

We use game theory techniques to automatically compute improved lower bounds on the competitive ratio for the bin stretching problem. Using these techniques, we improve the best lower bound for this problem to 19/14. We explain the technique and show that it can be generalized to compute lower bounds for any online or semi-online packing or scheduling problem.     

Buchbesprechungen

Ohne Zusammenfassung     

Wave-obstacle interaction in a lossy medium: energy perturbations and negative extinction

The concept of a generalized extinction cross-section introduced in a previous paper is given in detail and exemplified by the problem of scattering by an elastic cylinder embedded in a viscoelastic matrix. It is shown that under certain conditions the presence of inclusion may have a supporting effect on wave propagation (negative extinction). The derived low-frequency expansions indicate that the Rayleigh law may not hold in the case of a lossy medium. Numerical results as well as discussions concerning separation between scattering and intrinsic viscoelastic losses are also given.     

Über koaxiale euklidische Schraubungen

Ohne ZusammenfassungMit 7 Textabbildungen     

Buchbesprechungen

Ohne Zusammenfassung     

Die konstant gedrallte Netzfläche 4. Grades

Ohne ZusammenfassungMit 1 Textabbildung