Some results about amalgamation of semigroups

In this talk I shall discuss the existence of pushouts in the category of semigroups. I shall show that a semigroup amalgam is embeddable if and only if it is naturally embeddable in its pushout. I shall discuss some embeddable as well as nonembeddable semigroup amalgams. At the end I shall give an open question regarding the embedding of semigroup amalgams.