The sub-wavelength resonances, known to exist in metamaterial radiators and scatterers of circular cylindrical shape, are investigated with the aim of determining if these resonances also exist for polygonal cylinders and, if so, how they are affected by the shape of the polygon. To this end, a set of polygonal cylinders excited by a nearby electric line current is analyzed numerically and it i...

We show that some pieces of cylinders bounded by two parallel straight lines bifurcate in a family of periodic nonrotational surfaces with constant mean curvature and with the same boundary conditions. These cylinders are initial interfaces in a problem of microscale range modeling the morphologies that adopt a liquid deposited in a chemically structured substrate with striped geometry or a liq...

We design and test micro-watt energy-harvesters inspired by tree trunks swaying in the wind. A uniform flow vibrates a linear array of four cylinders affixed to piezoelectric energy transducers. Particular attention is paid to measuring the energy generated as a function of cylinder spacing, flow speed, and relative position of the cylinder within the array. Peak power is generated using cylind...

An efficient numerical method is developed for computing the transmission and reflection spectra of finite two-dimensional photonic crystals composed of circular cylinders in a triangular lattice. Our method manipulates a pair of operators defined on a set of curves and it remains effective when the radius of the cylinders is larger than √ 3/4 of the lattice constant — a condition where differe...

in industry, flow instabilities are important in journal bearings at high rotational speeds. for inviscid flows between two rotating coaxial cylinders, an instability criterion was introduced by taylor-couette. however, viscosity may play as stabilizer or destabilize in such flows. in this work, stability theories were reviewed for two coaxial rotating cylinders. then, flow instability patterns...

In this paper we study two analytical aspects of the theory of pseudoholomorphic cylinders in symplectisations. First we give a precise asymptotic formula for the behavior of a pseudoholomorphic curve near a non-removable puncture. Then we prove a regularity result for the manifold obtained by gluing to a pseudoholomorphic half-cylinder its asymptotic limit.

The Taylor–Couette problem for a rarefied gas is studied numerically by the direct simulation Monte Carlo method. The gas is supposed to be contained in an annular domain, bounded by two coaxial rotating cylinders and top and bottom (specularly reflecting) boundaries, and the flow is assumed to be steady and axisymmetric. Special attention is focused on the effect of rotation of the outer cylin...