Equations of motion for constrained systems

"Series title: Springerbriefs in applied sciences and technology, ISSN 2191-530X"

Presence of starch enhances in vitro biodegradation and biocompatibility of a gentamicin delivery formulation

The effect of α-amylase degradation on the release of gentamicin from starch-conjugated chitosan microparticles was investigated up to 60 days. Scanning electron microscopic observations showed an increase in the porosity and surface roughness of the microparticles as well as reduced diameters. This was confirmed by 67% weight loss of the microparticles in the presence of α-amylase. Over time, a highly porous matrix was obtained leading to increased permeability and increased water uptake with possible diffusion of gentamicin. Indeed, a faster release of gentamicin was observed with α-amylase. Starch-conjugated chitosan particles are non-toxic and highly biocompatible for an osteoblast (SaOs-2) and fibroblast (L929) cell line as well as adipose-derived stem cells. When differently produced starch-conjugated chitosan particles were tested, their cytotoxic effect on SaOs-2 cells was found to be dependent on the crosslinking agent and on the amount of starch used.

Euler angles, Bryant angles and Euler parameters

This chapter deals with the different approaches for describing the rotational coordinates in spatial multibody systems. In this process, Euler angles and Bryant angles are briefly characterized. Particular emphasis is given to Euler parameters, which are utilized to describe the rotational coordinates in the present work. In addition, for all the types of coordinates considered in this chapter, a characterization of the transformation matrix is fully described.

Vector of coordinates, velocities and accelerations

This chapter describes the how the vector of coordinates are defined in the formulation of spatial multibody systems. For this purpose, the translational motion is described in terms of Cartesian coordinates, while rotational motion is specified using the technique of Euler parameters. This approach avoids the computational difficulties associated with the singularities in the case of using Euler angles or Bryant angles. Moreover, the formulation of the velocities vector and accelerations vector is presented and analyzed here. These two sets of vectors are defined in terms of translational and rotational coordinates.

Multibody systems formulation

"Series: Solid mechanics and its applications, vol. 226"