Abstract. The problem of Rayleigh–Bénard convection with internal heat sources and a variable gravity field is treated. For the case of stress-free boundary conditions, it is proved that the principle of exchange of stabilities holds as long as the product of gravity field and the integral of the heat sources is nonnegative throughout the layer. The proof is based on the idea of a positive oper...

Rayleigh-Bénard convection with internal heat sources and a variable gravity field is treated with no-slip boundary conditions. It is proved that the principle of exchange of stabilities holds at all Prandtl numbers, as long as the gravity field and the integral of the heat sources both have the same sign. The proof is based on the idea of a positive operator, and uses the positivity properties...

The influence of the gravity and magnetic field on the propagation of Rayleigh wave in a prestressed inhomogeneous, orthotropic elastic solid medium has been discussed. The method of separation of variable has been used to find the frequency equations for the surface waves. The obtained dispersion equations are in agreement with the classical results when gravity, magnetic field, non-homogeneit...

Edge detection and edge enhancement techniques play an essential role in interpreting potential field data. This paper describes the application of various edge detection techniques to gravity data in order to delineate the edges of subsurface structures. The edge detection methods comprise analytic signal, total horizontal derivative (THDR), theta angle, tilt angle, hyperbolic of tilt angle (H...

changing altimetry information from satellites on the surface of seas and oceans, into anomaly gravity for example free air anomaly, is a fundamentally new method presented by researches. the determination of the free air gravity anomaly over the earth’s marine regions has led to a major improvement in our understanding of plate tectonic processes relating to oceanic ridges, the formation of ma...