The results of numerical modeling of sonic crystals with resonant array elements are reported. The investigated resonant elements include plain slotted cylinders as well as their various combinations, in particular, Russian doll or Matryoshka configurations. The acoustic band structure and transmission characteristics of such systems have been computed with the use of finite element methods. Th...

Mechanical angular momentum is not conserved in systems involving electromagnetic fields with non-zero electromagnetic field angular momentum. Conservation is restored only if the total (mechanical and field) angular momentum is considered. Previous studies have investigated this effect, known as “Feynman’s Electromagnetic Paradox” or simply “Disk Paradox” in the context of idealized systems (i...

A linear stability analysis has been carried out for flow between porous concentric cylinders when radial flow is present. Several radius ratios with corotating and counter-rotating cylinders were considered. The radial Reynolds number, based on the radial velocity at the inner cylinder and the inner radius, was varied from -30 to 30. The stability equations form an eigenvalue problem that was ...

Porous structures have been widely applied in the coastal and ocean engineering due to their wave energy dissipation mechanism. The macroscopic computational fluid dynamics (CFD) approach where quadratic pressure drop condition of porous surface is introduced model interaction with cylinders. A series CFD simulations waves interacting a single cylinder combined structure concentric inner solid ...

[1] An antenna configuration consisting of an arbitrarily located electric line source radiating in the presence of a pair of concentric metamaterial cylinders is investigated analytically and numerically. The nearand far-field properties of these structures are analyzed through an investigation of such parameters as the total radiated power, directivity, and total as well as differential scatt...

We consider the problem of recovering linear image Bx of a signal x known to belong to a given convex compact set X from indirect observation ω = Ax + σξ of x corrupted by Gaussian noise ξ. It is shown that under some assumptions on X (satisfied, e.g., when X is the intersection of K concentric ellipsoids/elliptic cylinders), an easy-to-compute linear estimate is near-optimal in terms of its wo...

The XENON100 experiment uses 161kg of liquid xenon divided in two concentric cylinders. The inner volume is the time-projection chamber, the outer volume is the veto, and they are separated by PTFE (Teflon) panels. In the region 350nm to 1200nm, PTFE has a measured reflectivity of 99%. However, xenon emits in the UV region, and the reflectivity distribution is not sufficiently understood here. ...

Taylor vortex flow between two concentric rotating cylinders with finite axial length includes various patterns of laminar and turbulent flows, and its behavior has attracted great interests. When mode bifurcation occurs, quantitative parameters such as the volume-averaged energy change rapidly. It is important to visualize the behaviors of vortices. In this study, a three-dimensional visualiza...

The flow of a magnetic fluid placed inside a small gap between concentric rotating cylinders is investigated for axial, radial and azimuthal magnetic fields. An equation of motion is derived phenomenologically to describe the hydrodynamics of magnetic fluids. Studied are the changes in the critical Taylor number T~ and wave number kc which characterize the instability of primary circular Couett...

The symmetric core of the nuclear pore complex can be considered schematically as a series of concentric cylinders. A peripheral cylinder coating the pore membrane contains the previously characterized, elongated heptamer that harbors Sec13-Nup145C in its middle section. Strikingly, Sec13-Nup145C crystallizes as a hetero-octamer in two space groups. Oligomerization of Sec13-Nup145C was confirme...