| The study of dynamic equations on time scales which goes back to its founder Stefan Hilger is an area of mathematics that has recently received a lot of attention. It has been created in order to unify the study of differential and difference equations. This article is composed of four chapters. In chapter 1, we present the history, development of differential equations on measure chains. In chapter 2, we introduce the preliminaries of dynamic equations on measure chain. In chapter 3, we study the existence of positive solution for boundary value problem for second order dynamic equations, and establish three sufficient conditions. Our criteria improve some known results. In chapter 4, we study the global attractivity of a class of rational difference equation. |