The asymmetric, elliptical shape of a transcatheter aortic valve (TAV), after implantation into a calcified aortic root, has been clinically observed. However, the impact of elliptical TAV configuration on TAV leaflet stress and strain distribution and valve regurgitation is largely unknown. In this study, we developed computational models of elliptical TAVs based on a thin pericardial bioprost...

We present new data on the globular cluster system of the elliptical galaxy NGC 3923 which show that it has the most globular clusters per unit luminosity of any noncluster elliptical yet observed, with SN = 6:4 1:4. NGC 3923 is also among the brightest ellipticals outside of a galaxy cluster for which the number of globular clusters has been determined. Our observation of a large number of clu...

Electromagnetic beams in a uniaxial crystal are treated with emphasis on the extraordinary mode. A virtual source that generates a basic elliptical Gaussian wave propagating obliquely to the optic axis is identified. An exact expression is obtained for this basic elliptical Gaussian wave that simplifies to the corresponding basic elliptical Gaussian beam in the appropriate limit. In the directi...

A high-speed method for elliptical object location is proposed. Through the use of the geometric symmetry, it first locates the centers of elliptical objects and classifies the boundary points. Then, each point possible on an elliptical object boundary is used to obtain the remaining three parameters of the elliptical object. Since each boundary point is at most transformed to one point on the ...

A new elliptical invisible cloak is proposed using a coordinate transformation in the elliptical-cylindrical coordinate system, which crushes the cloaked object to a line segment instead of a point. The elliptical cloak is reduced to a nearly-circular cloak if the elliptical focus becomes very small. The advantage of the proposed invisible cloak is that none of the parameters is singular and th...

The use of elliptical chainrings (also called chainwheels or sprockets) has gained considerable interest in the amateur and professional cycling community. Nevertheless, we are unaware of any scientific studies that have examined the performance benefits of using elliptical chainrings during an actual performance trial. Therefore, this study examined the influence of elliptical chainring use on...

Elliptical galaxies were once thought to be similar in their structure and dynamics to rotationally flattened bodies like stars. The discovery that elliptical galaxies rotate much more slowly than a fluid body with the same shape has led to a qualitative change in our understanding of the dynamics of these systems. It is now believed that elliptical galaxies are fully triaxial in shape. Self-co...

We analyse the effect of a low-frequency elliptically polarized electric field on an excited hydrogen atom using classical dynamics. It is shown that at particular frequencies the ionization probability is a non-monotonic function of the field strength and that at these frequencies the classical ionization probabilities agree well with those of experiment. We show that this unusual behaviour is...

We study the influence of particle shape on the shear band formation in quasistatic granular media in biaxial compression test using two-dimensional Distinct Element Method (DEM). Elliptical-shaped particles are used to study the influence of particle shape. We also report an experimental verification to check the ability of DEM to model elliptical particles created by the clustering technique....