This thesis is composed of four chapters, two of which, Chapter 3 and Chapter 4, contain original results. In Chapter 1 we recall some basic notions and establish some of the notation and terminology which will be used in ...

The service sector lies at the heart of industrialized nations and continues to serve as a major contributor to the world economy. Over the years, the service industry has given rise to an enor- mous amount of technological, ...

A conservation law is a partial di_erential equation, in which the variable is a quantity which remains constant in time, that is it cannot be created and destroyed. Thanks to the conservation laws it is possible to de_ne ...

The aim of this work is to explore the relationship between the manipulation of linguistic objects and the development of logical-deductive abilities, through teaching experiments in primary and secondary schools. Our ...

This thesis is a contribution to the research program ‘toposes as bridges’ introduced in [12], which aims at developing the unifying potential of the notion of Grothendieck topos as a means for relating different ...