Laser-driven ultrafast electron emission offers the possibility of manipulation and control of coherent electron motion in ultrashort spatiotemporal scales. Here, an analytical solution is constructed for the highly nonlinear electron emission from a dc biased metal surface illuminated by a single frequency laser, by solving the time-dependent Schrödinger equation exactly. The solution is valid...

Abstract This paper investigates bidirectional DC-DC converters in distributed electric propulsion systems, focusing on the dual active bridge (DAB) converter. To minimize voltage fluctuations aircraft operating under complex conditions, a virtual compensation control strategy based disturbance rejection (ADR-VVCC) is presented. The presented grounded working characteristics single-phase-shift ...

A subdermally implantable flexible photovoltatic (IPV) device is proposed for supplying sustainable electric power to in vivo medical implants. Electric properties of the implanted IPV device are characterized in live animal models. Feasibility of this strategy is demonstrated by operating a flexible pacemaker with the subdermal IPV device which generates DC electric power of ≈647 μW under the ...

Most of modern controlled electric drive applications, such as lifts, cranes, and tooling machines, are characterized by a high ratio of the peak to average power. In addition, such applications have high demand for braking at the full rated power. In ordinary drives, the braking energy, which represents 30%–50% of the consumed energy, is dissipated on a brake resistor. Apart from this ―energet...

The dark conglomerate (DC) phase exhibited by a bent-core liquid crystal shows remarkable properties including an electric-field tunable chiral domain structure and a large (0.045) reduction of refractive index, while maintaining an optically dark texture when observed under crossed polarizers. A detailed investigation of the system is presented, leading to a model that is fully consistent with...

The flashover strength of epoxy (EP) insulations in the High voltage direct current applications future energy grids can be improved by tailoring their surface condition. This work aims to improve DC characteristics EP after being treated with sandpaper different gradings. Samples virgin and homogenously modified considering varying roughness (Ra = 0.54, 3.16, 5.24, 8.35 μm) are prepared. Diffe...

This paper is concerned with transient dynamics and stability of an electric power system with dc transmission. Nowadays dc transmission systems are widely applied to conventional electric power systems. However, transient dynamics of ac/dc power systems, affected by active power which flows into dc transmissions, is not entirely understood. In this paper an unsymmetrical swing equation system ...