This paper gives some estimates relating to the Oleinik entropy inequa
lity for a single conservation law in one space dimension. We define a
functional phi(alpha)(T, U, epsilon) and show that it is bounded unif
ormly for certain entropy solutions U (and unbounded for rarefaction s
hocks) as epsilon --> 0. This suggests that the boundedness of the fun
ctionals phi(alpha)(T, U, epsilon) could possibly be viewed as an entr
opy condition.