Kebir (1994) (see also Shaked and Shanthikumar, 1994) has characterized likelihood ratio (LR) ordering, failure rate (FR) ordering, reversed hazard rate ordering and stochastic (ST) ordering with the help of Laplace transform. Using Laplace transform, Nanda (1995) has characterized, by means of necessary and sufficient conditions, the property that two life distributions are ordered in the s-FR...