Within the context of the total electron density distribution, a well-defined set of radii known as bonded radii can be derived by measuring, along the bond path, the distance between the center of an atom and the point of minimum electron density. As the properties of a crystal, including its total energy, are determined by its electron density distribution, such radii provide an objective mea...

We study strong coupling effects in four-dimensional heterotic string models where supersymmetry is spontaneously broken with large internal dimensions, consistently with perturbative unification of gauge couplings. These effects give rise to thresholds associated to the dual theories: type I superstring or M-theory. In the case of one large dimension, we find that these thresholds appear close...

Stamping simulations usually make the plane stress simplifying assumption. However, this becomes less valid when material draws around features with radius to sheet thickness ratios less than 20. Pereira, Yan & Rolfe (Wear, Vol.265, p.1687 (2008)) predicted that out-of-plane stress equivalent to material yield can occur because a line contact forms briefly at the start of the draw process. The ...

We demonstrate that the existence of a Noether symmetry in f (R) theories of gravity gives rise to an additional gravitational radius, besides the standard Schwarzschild one, determining the dynamics at galactic scales. By this feature, it is possible to explain the baryonic Tully-Fisher relation and the rotation curve of gas-rich galaxies without the dark matter hypothesis. Furthermore, under ...

It is known that every closed curve of length ≤ 4 in Rn (n > 0) can be surrounded by a sphere of radius 1, and that this is the best bound. Letting S denote the circle of circumference 4, with the arc-length metric, we here express this fact by saying that the mapping radius of S in Rn is 1. Tools are developed for estimating the mapping radius of a metric space X in a metric space Y. In partic...