Rheology involves the study of the deformation and flow of matter. The goal is to establish relationships between stress and deformation for (non-Newtonian) materials where neither Newton's law nor Hooke's law suffice to explain their mechanical behaviour. Many materials exhibit a non-Newtonian behaviour and the area is relevant in many fields of study from industrial to technological applications such as concrete technology, geology, polymers and composites, plastics processing, paint flow, hemorheology, cosmetics, adhesives, etc