Some Properties of -open Sets
A coating for improved resistance welding of galvanized steel parts or sheets comprises a binder, and a metal phosphide pigment, preferably a ferrophosphorus pigment, having a particle size of from about 0.1 to about 30 microns. The pigment can also include up to about 40% by weight of an additional metal such as tin, aluminum or lead, which can be combined with the metal phosphide in pigment form or deposited onto the surface of the particles. The coating can be applied to either the faying or non-faying surfaces of the galvanized steel, or to the resistance welding electrode, and may be removed, if desired, after the welding operation. The advantages of the present invention include a significant reduction in welding current and an increase in the weldability lobe width, a restoration of the dynamic resistance beta peak, and an increase in electrode life.
Groups of θ-generalized homeomorphisms and the digital line
Abstract We establish the connection between two fields of Topology that until now seemed to be far away from each other, namely digital topology and the theory of generalized closed sets. In this paper we study θ -generalized homeomorphisms, their groups and some allied concepts applied to digital topology.
A note on $S$-closed spaces
ABsTRAcr. A topological space X is said to be S-closed if and only if for every semi-open cover of X there exists a finite subfamily such that the union of their closures cover X. For a Hausdorff space, the concept of S-closed is shown to be equivalent to the concept of extremally disconnected and nearly compact. Further it has been shown that EDH-closed spaces are precisely S-closed Hausdorff spaces.