The Reuss Bound of the Strain Rate Potential of Viscoplastic FCC Polycrystals

The Reuss bound of the strain rate potential of face-centered cubic polycrystals without texture is numerically determined for all types of stress states. The numerical results indicate a strong dependence of the potential on the determinant of the stress deviator. This dependence implies that the viscoplastic f low is not proportional to the stress deviator. A simple analytical expression is found, which  reproduces the numerical f indings over a wide range of strain rate sensitivities

Crystallographic Texture Induced Anisotropy in Copper: An Approach Based on a Tensorial Fourier Expansion of the CODF

We consider a tensorial Fourier expansion of the crystallite orientation distribution function for aggregates of cubic crystals. The coefficient of rank four is determined explicitly. It is shown that this coefficient governs the anisotropic bounds of the linear elastic behavior of polycrystals. Recently, a phenomenological model has been proposed [4, 6], that describes the evolving elastic anisotropy in copper. The model also reproduces the cyclic Swift effect, which is due to a texture induced plastic anisotropy [7]. In the model the anisotropic part of the effective elastic stiffness tensor is used to define a texture dependent quadratic yield function. The present paper gives a new interpretation of the aforementioned model in terms of an approximation of the crystallographic texture by means of a 4th-order coefficient of the tensorial Fourier expansion of the crystallite orientation distribution function

Comment on "Correlation between Compact Radio Lout Quasars and Ultrahigh Energy Cosmic Rays"

In a recent paper, Farrar and Biermann argue that there is a strong correlation between the direction of the five highest-energy cosmic-ray events and compact, radio-loud quasars. This Comment shows that this analysis contains several inconsistencies and errors so that the significance of any such correlation is certainly greatly overestimated and perhaps nonexistent.Comment: 2 pages, REVTE