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.
Properties of (θ,s)-continuous functions
Abstract Joseph and Kwack [Proc. Amer. Math. Soc. 80 (1980) 341–348] introduced the notion of ( θ , s )-continuous functions in order to investigate S -closed spaces due to Thompson [Proc. Amer. Math. Soc. 60 (1976) 335–338]. In this paper, further properties of ( θ , s )-continuous functions are obtained and relationships between ( θ , s )-continuity, contra-continuity and regular set-connectedness defined by Dontchev et al. [Internat. J. Math. Math. Sci. 19 (1996) 303–310 and elsewhere] are investigated.
COUNTABLY S-CLOSED SPACES
In this paper we introduce the class of countably S-closed spaces which lies between the familiar classes of S-closed spaces and feebly compact spaces. We characterize countably S-closed spaces and study their basic prop­ erties. In addition, we investigate the relationship between countably S-closed spaces and feebly compact spaces. Several examples illustrate our results.