In this paper we provide a constructive version of Tits alternative for a broad class of quaternions with algebraic coefficients. Our result is a generalization of that contained in the paper [1], concerning groups of rational quaternions. Indeed, the tools developed in [1] can be extended to arbitrary number fields by translating them in the corresponding Dedekind domain, as the techniques inv...

In this study, we investigate the semi-real quaternionic curves in the semi-Euclidean space E_4_2. Firstly, we introduce algebraic properties of semi-real quaternions. Then, we give some characterizations of semi-real quaternionic involute-evolute curves in the semi-Euclidean space E42 . Finally, we give an example illustrated with Mathematica Programme.

This paper presents the equations for the implementation of rotational quaternions in the geometrically exact three-dimensional beam theory. A new finite-element formulation is proposed in which the rotational quaternions are used for parametrization of rotations along the length of the beam. The formulation also satisfies the consistency condition that the equilibrium and the constitutive inte...