Some recent results on a general summability method, on the so-called θ-summability is summarized. New spaces, such as Wiener amalgams, Feichtinger’s algebra and modulation spaces are investigated in summability theory. Sufficient and necessary conditions are given for the norm and a.e. convergence of the θ-means.

In this paper we will prove analogues of B. Maier’s characterization of weak and strong embeddability of amalgams in N2 [12, 13] for the subvarieties of N2. We will also give analogues of D. Saracino’s characterization of weak and strong amalgamation bases [17], the author’s work on dominions [11] and on amalgamation bases in some varieties of nil-2 groups [8, 9]. Definitions will be recalled b...

The wear of cental amalgam was studied by single- and double-pass sliding and by a silicon carbide abrasion test. A dispersed amalgam showed significantly better resistance to two-body abrasion than the spherical amalgams tested. The wear amalgam was determined by resistance to penetration and by a ductile mode of surface failure over the load range studied. Differences in the wear of amalgam a...