This report provides an introduction to the problem of analyzing the performance of satellite on-board regenerative repeaters. Two speci c group demodulator architectures are discussed: one based on a polyphase network followed by an FFT processor, and the other based on a chirp Fourier transform implemented using surface acoustic wave (SAW) devices. Due to imperfect ltering and channel separat...

Thin film bulk acoustic wave (BAW) resonators and filters operating in the GHz range are used in mobile phones for the most demanding filtering applications and complement the surface acoustic wave (SAW) based filters. Their main advantages are small size and high performance at frequencies above 2 GHz. This work concentrates on the characterization, performance optimization, and modelling tech...

in this paper, we investigated the corrected plasmon dispersion relation for graphene in presence of a constant magnetic field which it includes a quantum term arising from the collective electron density wave interference effects. by using quantum hydrodynamic plasma model which incorporates the important quantum statistical pressure and electron diffraction force, the longitudinal plasmons ar...

In this paper, by using a quantum hydrodynamic plasma model which incorporates the important quantum statistical pressure and electron diffraction force, we present the corrected plasmon dispersion relation for graphene which includes a k quantum term arising from the collective electron density wave interference effects (which  is integer and constant and k is wave vector). The longitudinal ...

This paper introduces methods to generate crawling wave interference patterns from the displacement fields generated from radiation force pushes on a GE Logiq 9 scanner. The same transducer and system provides both the pushing pulses to generate the shear waves and the tracking pulses to measure the displacements. Acoustic power and system limitations result in largely impulsive displacement fi...

We have made precision measurements of the frequency of a collective mode of the superfluid 3 He-B order parameter, the J = 2 − imaginary squashing mode. Measurements were performed at multiple pressures using interference of transverse sound in an acoustic cavity. Transverse waves propagate in the vicinity of this order parameter mode owing to off-resonant coupling. At the crossing of the soun...

The late eighteenth and early nineteenth centuries saw what is known today as the Highland Clearances, which was in effect the forced migration of a large proportion of the population of the Scottish Highlands due to intensified sheep farming in the name of a more effective economic land use (Devine, 1999, pp.176-78). For the Gaelic speech community this meant ‘the removal of its heartland’ (Ma...

Our understanding of the genetic mechanisms of organismal aging has advanced dramatically during the past two decades. With the development of large-scale RNAi screens, the last few years saw the remarkable identifications of hundreds of new longevity genes in the roundworm Caenorhabditis elegans. The various RNAi screens revealed many biological pathways previously unknown to be related to agi...