The physical nature of the initial transition to three-dimensionality of #ow past a circular cylinder has been the subject of considerable debate in the literature. Of several proposed mechanisms, the possibility of classi"cation as an elliptical instability is re-examined in this article. Detailed Floquet analysis of the transition shows clear evidence of the growth of an elliptic instability ...

A CNC machine tool for machining designed to facilitate the replacement of cutting tools includes a workbench, motor and hydraulic cylinder. The inner bearing workbench is connected with rotating rod, outer key rod half gear, output end lower rod. machining, which convenient replacing tools, realizes linkage between body adjusting gear by using tooth block, drives move rotation screw adjust pos...

We study a Dirichlet spectral problem for second-order elliptic operator with locally periodic coefficients in thin cylinder. The lateral boundary of the cylinder is assumed to be periodic. When thickness ε tends zero, eigenvalues are order ε−2 and described terms first eigenvalue μ(x1) an auxiliary cell parametrized by x1, while eigenfunctions localize rate ε.