Giant Cyclones in Gaseous Discs of Spiral Galaxies

We report detection of giant cyclonic vortices in the gaseous disc of the spiral galaxy NGC 3631 in the reference frame rotating with the spiral pattern. A presence of such structures was predicted by the authors for galaxies, where the radial gradient of the perturbed velocity exceeds that of the rotational velocity. This situation really takes place in NGC 3631.Comment: 13 pages, 4 EPS and 3 PS figure

Study of corona discharge treated poly(ethylene terephtalate) films by atomic force microscopy

© 2020 Published under licence by IOP Publishing Ltd. The paper studies poly(ethylene terephthalate) films modified in corona discharge. Surface topography and elastic properties of films dependence on the distance between needle and grounded substrate are obtained by atomic force microscopy

Wavelet-based numerical and semianalytical methods of computational local structural analysis

Numerical or semianalytical solution of problems of structural mechanics of high dimensionality is computationally costly process in many cases. However, structural engineer does not normally face the task of obtaining a solution of the problem with high accuracy at all points of the considered domain occupied by the structure. As a rule, all subdomains that are potentially dangerous in terms of structural strength are well known in advance. Operational and variational formulations of boundary problems of structural mechanics with the use of method of extended domain are presented. After corresponding (finite element or finite difference) discretization and passage to governing equations considering problems are transformed to a multilevel space with the use of multilevel wavelet transform (discrete Haar basis is used). Special algorithms of averaging are presented. © Published under licence by IOP Publishing Ltd