Individual multiwalled carbon nanotube field emitters were prepared in a scanning electron microscope. The angular current density, energy spectra, and the emission stability of the field-emitted electrons were measured. An estimate of the electron source brightness was extracted from the measurements. The results show that carbon nanotubes are promising candidates to replace existing sources i...

A broadband Circuit Analogue (CA) absorber using double-circular-loop array is investigated in this paper. A simple equivalent circuit model is presented to accurately analyze this CA absorber. The circuit simulation of the proposed model agrees well with full-wave simulations. Optimization based the equivalent circuit model, is applied to design a single-layer circuit analogue absorber using d...

We consider conditions of structural stability under which the array of singular beams preserves its topological structure and intensity distribution while slightly perturbing its intrinsic parameters. The orbital angular momentum of the array as a function of the array parameters is a characteristic function, and its extreme points correspond to stable and unstable array states.

We investigate a class of vector ring spatial solitons that carry no net angular momentum. Specifically, we show analytically and numerically that the dominant low-frequency perturbations that typically disrupt ring solitons are suppressed for these solitons. By comparing our analytical and numerical results, we show that our simple analysis gives good qualitative predictions on the regions of ...

The motion of a stone skimming over a water surface is considered. A simplified description of the collisional process of the stone with water is proposed. The maximum number of bounces is estimated by considering both the slowing down of the stone and its angular stability. The conditions for a successful throw are discussed. © 2003 American Association of Physics Teachers. @DOI: 10.1119/1.151...

The gimbal stabilization mechanism system is used to provide the stability to an object mounted on the gimbal by isolating it from the base angular motion and vibration. In this paper the model of one axis gimbal system with dynamics flying object is introduced. The gimbal torque relationships are obtained using Newton’s second law equation on the assumption that gimbal is rigid body. The syste...

The main goal of this research is to analyse the effect of angular velocity on stability and vibration of a simply supported Rayleigh rotating shaft. To this end, non-dimensional kinetic and potential energies are written while lateral vibration is considered. Finite element method is employed to discrete the formulations and Linear method is applied to analyse instability threshold of a rotati...

this paper uses the tsuji’s characteristic to investigate the uniqueness of transcen- dental meromorphic function with shared values in an angular domain dealing with the multiple values which improve a result of j. zheng.

New families of exact analytical Helmholtz solitons are presented for various material nonlinearities, and simulations confirm their stability. A novel generalization of Snell’s Law for Kerr solitons is also reported. Helmholtz angular corrections to paraxial theory, exceeding 100%, are uncovered. © 2007 Optical Society of America OCIS codes: (190.4400) Nonlinear Optics, Materials; (190.9540) N...