Abstract:  I  will  present a talk, intended for the recent AMS
meeting  that  I  was  not  able  to  attend,  about  cotorsion
envelopes and free covers. The main result is that they commute
with each other (over any ring). The result is motivated by and
related  to  questions  about  the  class  of  rings over which
pure-injective  envelopes  of flat modules are flat, a class of
rings that properly contains all coherent rings (which I talked
about  earlier  in  this  seminar). In the course of the talk I
will try and explain most of the above technical terms.