It has long been assumed that Rayleigh lidar can be used to measure atmospheric temperature profiles up to about 90 or 100 km and that above this region the technique becomes invalid due to changes in atmospheric composition which affect basic assumptions on which Rayleigh lidar is based. Modern powerful Rayleigh lidars are able to measure backscatter from well above 100 km requiring a closer e...

A new upper bound on the rate of vertical heat transport is established in 3 dimensions for stress-free velocity boundary conditions on horizontally periodic plates. For large (but finite) Prandtl numbers this bound is an improvement over the ‘ultimate’ Ra scaling and in the limit of infinite Pr, agrees with the bound of Ra recently derived in that limit. keywords: Rayleigh-Bénard convection, B...

We compute the cyclicity of open period annuli following generalized Rayleigh-Liénard equation \begin{document}$ \ddot{x}+ax+bx^3-(\lambda_1+\lambda_2 x^2+\lambda_3\dot{x}^2+\lambda_4 x^4+\lambda_5\dot{x}^4+\lambda_6 x^6)\dot{x} = 0 $\end{document} and equivalent planar system $ X_\lambda $, where coefficients perturbation \lambda_j are independent small parameters a, b fixed nonzero constants....

2014 The model of the potential function V(x), for the hysteresis cycles in a weak field of a ferromagnetic sample, demagnetized by an alternating field, leads to Rayleigh’s laws. In the case of a thermal demagnetization, the Bloch wall may be present in every well of V(x), and the domain structure is initially metastable. Considering all configurations where we can find the Bloch wall, in Néel...