A typical confocal resonator for THz radiation produced by an FEL will have a waist that is larger than the gap of the undulator. Hence waveguiding is required. Here we consider a resonator consisting of two spherical mirrors and a cylindrical waveguide in between. The radii of curvature for the mirrors are chosen to image the ends of the waveguide onto themselves. We discuss the properties of ...

A typical confocal resonator for THz radiation produced by an FEL will have a waist that is larger than the gap of the undulator. Hence waveguiding is required. Here we consider a resonator consisting of two spherical mirrors and a cylindrical waveguide in between. The radii of curvature for the mirrors are chosen to image the ends of the waveguide onto themselves. We discuss the properties of ...

We give an example of a spacetime having an infinite thin rotating cylindrical shell constituted by a charged perfect fluid as a source. As the interior of the shell the Bonnor–Melvin universe is considered, while its exterior is represented by Datta– Raychaudhuri spacetime. We discuss the energy conditions and we show that our spacetime contains closed timelike curves. Trajectories of charged ...

An analysis i presented ofthe impedance presented by a thin cylindrical e astic shell to a pressure or normal stress as a function of the axial wavelength and the angular dependence of the forces. Results of computation are presented graphically. This information is then used to compute a measure of the sound transmitted through the shell immersed inair for various particular cases. The theory ...

Using  principle  of  minimum  total  potential  energy  approach  in conjunction  with  Rayleigh-Ritz  method,  the  electro-thermo- mechanical  axial  buckling  behavior  of  piezoelectric  polymeric cylindrical  shell  reinforced  with  double-walled  boron-nitride nanotube  (DWBNNT)  is  investigated. Coupling  between  electrical and mechanical  fields  are  considered  according  to  ...

We give an example of a spacetime having an infinite thin rotating cylindrical shell constituted by a charged perfect fluid as a source. As the interior of the shell the Bonnor–Melvin universe is considered, while its exterior is represented by Datta– Raychaudhuri spacetime. We discuss the energy conditions and we show that our spacetime contains closed timelike curves. Trajectories of charged ...

This thesis presents design of dielectric resonator loaded antenna for wireless applications. The design is a Different shape Dielectric Resonator Antenna (DRA) using different material for wireless applications. Here the DRA is excited by conformal patch connected to co-axial feeding which is an effective feed mechanism and more efficient in energy coupling than other types of feeding techniqu...

In this study a vibration analysis was performed of an isotropic cylindrical shell submerged in fluid, resting on Winkler and Pasternak elastic foundations for simply supported boundary condition. Love’s thin theory exploited strain- curvature- displacement relationship. Shell problem solved by using wave propagation approach. Influence fluid as well were studied the natural frequencies shells....

Using principle of minimum total potential energy approach in conjunction with Rayleigh-Ritz method, the electro-thermo-mechanical axial buckling behavior of piezoelectric polymeric cylindrical shell reinforced with double-walled boron-nitride nanotube (DWBNNT) is investigated. Coupling between electrical and mechanical fields are considered according to a representative volume element (RVE)-ba...