Aims: We present a statistical analysis of different characteristics ringed spiral galaxies with the aim assessing effects rings on disk galaxy properties. Methods: built catalog from Sloan Digital Sky Survey Data Release 14 (SDSS-DR14). Via visual inspection SDSS images, we classified face-on brighter than $g < 16.0$ mag into with: an inner ring, outer nuclear both and pseudo-ring. In addition...

Research on increasing the buckling strength of tanks carrying fluid and also cylindrical shells of thin-walled steel in civil engineering and mechanics is important. This is due to the widespread use of these structures in the industry. Due to the low thickness of the body and also due to the pressure forces entering these tanks, these structures are exposed to lateral buckling. In this resear...

Design of some crystal and quasicrystal networks, based on rhombellane tiling,is presented. [1,1,1]Propellane,is a synthesized organic molecule; its hydrogenated form, the bicyclo[1.1.1]pentane,may be represented by the complete bipartite graph K2,3 which is the smallest rhombellane. Topology of translational and radial structures involving rhombellanes is described in terms of vertex symbol, c...

In this paper, Using a 2D photonic crystal and a novel square ring resonator,several compact and simple structures have been introduced in the present paper toconstruct optical add/drop filters and multi-channel filter. The difference structures hasbeen designed and simulated by using the proposed square ring resonator and differentdropping waveguides. To do analyses, th...

in this paper, we study fuzzy substructures in connection withhv-structures. the original idea comes from geometry, especially from thetwo dimensional euclidean vector space. using parameters, we obtain a largenumber of hyperstructures of the group-like or ring-like types. we connect,also, the mentioned hyperstructures with the theta-operations to obtain morestrict hyperstructures, as hv-groups...

in this note we introduce the notion of weak mccoy rings as a generalization of mccoy rings, and investigate their properties. also we show that, if is a semi-commutative ring, then is weak mccoy if and only if is weak mccoy.