We report an experimental study of porous silicon-based rugate filters. Possible optimisations that can improve different features of the filters are investigated. We demonstrate sidelobe attenuation by means of half-apodization of the structures with a sinusoidal window. Reduction of interference ripples are experimentally observed through the insertion of index-matching layers on the boundari...

Abstract. The paper introduces a new approach for voltage balance monitoring based on the computer-aided assessment of the network Instantaneous Voltage’s Space Phasor (IVSP). Between the voltage unbalances severities and the IVSP modulus ripples or the IVSP angular speed ripples are identified the appropriate correspondences which are used for voltage unbalance quantifications. The investigati...

We use atomic force microscopy to image grain boundaries and ripples in graphene membranes obtained by chemical vapor deposition. Nanoindentation measurements reveal that out-of-plane ripples effectively soften graphene's in-plane stiffness. Furthermore, grain boundaries significantly decrease the breaking strength of these membranes. Molecular dynamics simulations reveal that grain boundaries ...

Switched Reluctance Machines are receiving significant attention from industries, because of its simple structure; inexpensive manufacturability and reliability make it superior to other electric machines. The objective of this paper is to achieve desired speed performance of 6/4 Switched Reluctance Motor (SRM) with reduced torque ripples. To achieve improved speed performance, PI+FUZZY control...

The measured drop of the effective bending stiffness of multiwalled carbon nanotubes (MWCNTs) with increasing diameter is investigated by a generalized local quasicontinuum method. The previous hypothesis that this reduction is due to a rippling mode is confirmed by the calculations. The observed ripples result from a complex three-dimensional deformation similar to the Yoshimura buckling patte...

The interaction of small amplitude water waves with a patch of bottom ripples is studied using the Boundary Integral Equation Method (BIEM). Normal and oblique wave incidence is examined for reflection coefficients and the laboratory data of Davies and Heathershaw are compared to the numerical results, with the conclusion that the analytical model of Davies and Heathershaw overestimates the ref...

The observations will be used to validate existing models and to develop new models for ripple geometry as a function of forcing hydrodynamics and seabed characteristics. The observations will also have a smaller focus on small scale sediment transport processes over ripples and larger scale wave field variability over spatially variable ripples. The small scale sediment transport process obser...

This paper considers direct torque control strategies in induction motor drive to minimize torque ripples. Spacevector modulation and modified space vector control concept is implemented to design the controller. Basic DTC method suffers from torque ripples problem and switching frequency variation.[1] Torque ripples are minimized using space vector modulation technique but execution time in th...