Two problems of W. V.
Vasconcelos are partially solved: (1) The total quotient ring of a commutative
noetherian ring R is quasi-frobenius if and only if EndR(A) is commutative for each
ideal A of R. (2) Let R be a commutative quasiregular ring and E a finitely
presented R-module. If E is faithful and EndR(E) is semi-prime, then E is
isomorphic to an ideal of R. Only commutative rings with unit and unital modules
are considered.