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.
Topological Property of θ-Semi-Open Sets
The concept of θ-semi-open sets in topological spaces was first introduced in 1986 by T. Noiri. Now, in the present paper, we introduce and study topological properties of θ-semi-neighborhood, θ-semi-interior, θs-derived, θ-semi-boundary, θ-semi-exterior and θs-border of a set via the concept of θ-semi-open sets. Also, we find several related amon g them.
Generalized closed sets: a unified approach
We investigate various classes of generalized closed sets of a topological space in a unified way by studying the notion of qr-closed sets. New characterizations of some existing classes of generalized closed sets and topological spaces are given. A new class of generalized closed sets are introduced.