-\chapter{Preface}
+\chapter*{Preface}
This book is intended to present the design of significant scientific
In order to be able to handle more complex applications, the use of
parallel architectures is the solution to decrease the execution
-times of theses applications. Using simulataneously many computing
+times of these applications. Using simulataneously many computing
cores can significantly speed up the processing time.
Nevertheless using parallel architectures is not so easy and has always required
