SUMMARY Background

The small intestine is a part of the gastrointestinal segment comprising of the duodenum, jejunum, and ileum. They help to process the gastric contents for further digestion, which involves mixing with duodeno-biliary-pancreatic (DBP) secretions to facilitate the chemical digestion, and homogenization of the luminal contents through contractions of the circular and longitudinal smooth muscle fibers of the intestine. The contractions of these smooth muscle fibers develops the mechanical forces at the mucosal wall, which as a consequence, transfers its momentum to the underlying fluid to develop the fluid flows, suggesting relevance of mechanics in physiology. The resulting flows are what drive the digestion. Changes in contractility of wave shapes of circular and longitudinal smooth muscle contractions and fluid rheology are known to affect the digestive process through generation of various flow patterns that differ in luminal pressure, peak velocity, extent of shearing/ mixing, volume of mixing, and flow rate. Recent studies indicate that the digestive process can be very specific such as to cause lipid digestion through segmental contractions and transport by eliciting propagating contractions, suggesting that the intestine manages to digest a variety of food in an efficient manner by eliciting appropriate contractions.

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Sports biomechanics helps one to understand the sport movements and helps increase the performance of individuals and prevent injury. Understanding the mechanics involved in every sport is crucial for kinesiologists help patients to recover from traumatic or overuse injuries. Each sport activity has different phases, and in each phase, the kinetics and kinematics are studied for better understanding. Computational technologies help to understand sports movements and forces developed during motion and provide proper guidance that can be followed to avoid injuries and enhance performance. The aspects of biomechanical analysis of sports, injuries and their causes in sports, various techniques for recording and analysis of sports movements, and lastly, performance improvement and preventing injury using the analysis are discussed in this chapter.

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Inspired by the feeding mechanisms of a nematode, a novel two-indenter (2I) micropump is analyzed theoretically for transport and mixing of a non-Newtonian fluid for the purpose of lab-on-a-chip applications. Considering that the viscous forces dominate the flows in microscopic regime, the concept lubrication theory was adopted to device the two-dimensional flow model of the problem. By approximating the movements of the indenter as a sinusoidal function, the details of the flow were investigated for variations in -frequency of contraction of the first value keeping the second valve at higher occlusion, and occlusion. The study indicates that occlusive nature of the second valve leads to the large pressure barrier which prevents the fluid to enter into the neighboring compartment. Transport occurs as the lumen opens to develop a suction pressure. Pressure barrier is found to be highest for dilatants followed by Newtonian and pseudo-plastics. Shear stress dependency on frequency the contraction of the first value is highest for lower values of flow behavior index. In conclusion, the study provides details connecting the flows resulting from the indentation of the front-end indenter to the frequency of indentation, geometry and rheology of the fluid, thus facilitating optimal design of the micropumps.

In manufacturing industries, the metal removal is one of the processes