A common problem with radiofrequency (RF) receivers is that in addition to the desired signal, there is an interfering signal of much greater total power. These receivers can be for communications, radar, interception, etc. The interference can arise intentionally, such as from intentional jamming, or unintentionally, such as radiofrequency interference from a nearby transmitter. There is a nee...

Recent measurements of GPS-derived total electron content (TEC) reveal acoustic wave periods of ∼1–4 min in the F region ionosphere following natural hazard events, such as earthquakes, severe weather, and volcanoes. Here we simulate the ionospheric responses to infrasonic-acoustic waves, generated by vertical accelerations at the Earth’s surface or within the lower atmosphere, using a compress...

Acoustic asymmetrical transmission is a theoretical and engineering challenge because of the reciprocity linear acoustic wave equation. It can be achieved by systems breaking or reciprocal relying solely on spatial symmetry breaking. Metagratings are planar structures Bragg's diffraction to reroute energy toward desired direction eventually able achieve when build from an pattern multiple basic...

In their letter Akis and Ferry propose a quantum waveguide array approach for performing quantum Fourier transforms ~QFTs!. The waveguide produces 2 waves at its output with controllable relative phases; n is the number of binary splits of the input wave. The interference pattern from these waves is recorded and implements a Fourier transform. The authors claim that their waveguide approach is ...

On the basis of see-saw mechanism, possible generation structure is investigated. Assuming that right-handed neutrinos are realistic particles below GUTs mass, it is shown that there is a choice of new scheme of generation, where the combination of leptons and quarks is different from the ordinary one. Our scheme predict a new proton decay mode. 1 typeset using PTPTEX.sty §

We consider an acoustic wave system with discontinuous coe cients and nonsmooth inputs. Existence, uniqueness and continuous dependence on input data of weak solutions are established.

I. Introduction During the past three decades, there has been a paradigm shift from import substitution strategies towards export‐oriented industrialization. It is in this context that countries saw the need to create special economic zones (SEZs) and export processing zones (EPZs), so‐called ecozones, to cope with the increasingly competitive environment of the global market.