The energy of the stochastic magnetic field is bounded from below by a topological quantity expressing the degree of linkage of the field lines. When the bound is saturated one can assume that the storage of a certain magnetic energy requires a minimal degree of topologi-cal complexity. It is then possible to infer a connection between the helicity content and the average curvature of the magne...

Two planets with orbital period ratio approximately 10:1 have been discovered around the star HD 83443. The inner and more massive planet, HD 83443b, has the smallest semi-major axis among all currently known exoplanets. Unlike other short period exoplanets, it maintains a substantial orbital eccentricity, e1 = 0.079± 0.008, in spite of efficient tidal damping. This is a consequence of its secu...

The present research deals with the flexural-torsional buckling analysis of sandwich web and/or flanges tapered doubly-symmetric I-beam. All section walls are composed of two metal face layers and a functionally graded (FG) porous core. It is assumed that the material properties of the porous core vary gradually in the longitudinal direction according to the simple power-law function considerin...

The eccentricity e(v) of a vertex v in a strongly connected digraph G is the maximum distance from v. The eccentricity sequence of a digraph is the list of eccentricities of its vertices given in nondecreasing order. A sequence of positive integers is a digraphical eccentric sequence if it is the eccentricity sequence of some digraph. A set of positive integers S is a digraphical eccentric set ...

We propose a stable backbone tree construction algorithm using multi-hop clusters for wireless sensor networks (WSNs). The hierarchical cluster structure has advantages in data fusion and aggregation. Energy consumption can be decreased by managing nodes with cluster heads. Backbone nodes, which are responsible for performing and managing multi-hop communication, can reduce the communication ov...

BACKGROUND Coronary endothelial function (CEF) in patients with coronary artery disease (CAD) varies among coronary segments in a given patient. Because both coronary vessel wall eccentricity and coronary endothelial dysfunction are predictors of adverse outcomes, we hypothesized that local coronary endothelial dysfunction is associated with local coronary artery eccentricity. METHODS We used...

Context. Young planets embedded in their protoplanetary disk interact gravitationally with it leading to energy and angular momentum exchange. This interaction determines the evolution of the planet through changes to the orbital parameters. Aims. We investigate changes in the orbital elements of a 20 Earth–mass planet due to the torques from the disk. We focus on the non-linear evolution of in...