The onset of the back-firing instability is studied in a one-dimensional spatially extended and dissipative system, where propagating localized solutions become unstable. It corresponds to the emission in the tail of a solitary wave of a new wave propagating in the opposite direction. The transition is illustrated, in geometrical terms, using a model normal form equation. (c) 2004 American Inst...

the one-dimensional model of lippincott and schroeder for hydrogen bond has been re-examined and it has been shown that o-h bond distance depends on repulsive van der waals and attractive electrostatic potentials.it has been shown that constant b in the van der waals repulsion potential is not transferable to all hydrogen bonds. the possibility of obtaining the semi-empircal parameters in the l...

SIMULGEO is a geometrical software developed for the position monitoring system of the CMS detector at the LHC accelerator. This software is capable to model opto-geometrical systems including error propagation and geometrical reconstruction. Thanks to a special description method, any opto-geometrical system can easily be described and analysed. This report explains how to use SIMULGEO, descri...

Since tubes are widely used for different industrial applications, processing of tubes by the Severe Plastic Deformation (SPD) method has been the target of different attempts. Among these attempts, development of SPD processes for tubes based on Equal Channel Angular Pressing (ECAP) has been more successful. As an illustration, Tube Channel Pressing (TCP) has been presented as an attractive SP...

phase turbulence, but underpredict the two-phase fluctuation velocities, and the difference between the two model predictions is not obvious. 4. The nonlinear k-«-kp model has no problem of convergence encountered in the implicit algebraic stress model. 5. In two-dimensional flows with small geometrical sizes the NKP model can save about 50% computation time than the USM model. However, in thre...

On a geometrical view, the conception of map geometries is introduced , which is a nice model of the Smarandache geometries, also new kind of and more general intrinsic geometry of surfaces. Some open problems related combinatorial maps with the Riemann geometry and Smarandache geometries are presented.

A new T-duality transformation is found in two-dimensional non-linear sigma models. This is a straightforward generalisation of Abelian and non-Abelian T-dualities. It is shown, in particular, that a given non-linear sigma model can possess more than one dual theory. Finally, the construction of this duality is given a geometrical interpretation. e-mail: [email protected] CNRS UMR ...