A model of steady-state X-shaped wave generation by a superluminal (supersonic) pointlike source infinitely moving along a straight line is extended to a more realistic causal scenario of a source pulse launched at time zero and propagating rectilinearly at a constant superluminal speed. In the case of an infinitely short (delta) pulse, the new model yields an analytical solution, corresponding to the propagation-invariant X-shaped wave clipped by a droplet-shaped support, which perpetually expands along the propagation and transversal directions, thus tending the droplet-shaped wave to the X-shaped one.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1364/JOSAA.29.000457 | DOI Listing |
Front Netw Physiol
September 2024
Institute of Biomaterials and Biomolecular Systems, University of Stuttgart, Stuttgart, Germany.
The stability of wave conduction in the heart is strongly related to the proper interplay between the electrophysiological activation and mechanical contraction of myocytes and extracellular matrix (ECM) properties. In this study, we statistically compare bioengineered cardiac tissues cultured on soft hydrogels ( kPa) and rigid glass substrates by focusing on the critical threshold of alternans, network-physiological tissue properties, and the formation of stable spiral waves that manifest after wave breakups. For the classification of wave dynamics, we use an improved signal oversampling technique and introduce simple probability maps to identify and visualize spatially concordant and discordant alternans as V- and X-shaped probability distributions.
View Article and Find Full Text PDFPhys Rev E
February 2024
State Key Laboratory of High Temperature Gas Dynamics, Institute of Mechanics, Chinese Academy of Sciences, Beijing 100190, People's Republic of China.
To better understand the three-dimensional topology of the interaction between the shock train and the background wave, the steady and dynamic characteristics of a shock train were investigated using wind-tunnel experiments and numerical simulation. A 14° wedge placed at the bottom and sidewalls was used to generate background waves traveling in different directions. Mounting the wedge on the bottom wall at an incoming Mach number of 1.
View Article and Find Full Text PDFPhys Rev Lett
January 2021
Physics Department, University of Gothenburg, 412 96 Gothenburg, Sweden.
Controlling the directionality of spin waves is a key ingredient in wave-based computing methods such as magnonics. In this Letter, we demonstrate this particular aspect by using an all-optical pointlike source of continuous spin waves based on frequency comb rapid demagnetization. The emitted spin waves contain a range of k vectors and by detuning the applied magnetic field slightly off the ferromagnetic resonance (FMR), we observe X-shaped caustic spin wave patterns at 70° propagation angles as predicted by theory.
View Article and Find Full Text PDFPhys Rev Lett
November 2019
Department of Engineering Science, University of Oxford, Oxford OX1 3PJ, United Kingdom.
Stationary wave groups exist in a range of nonlinear dispersive media, including optics, Bose-Einstein condensates, plasma, and hydrodynamics. We report experimental observations of nonlinear surface gravity X waves, i.e.
View Article and Find Full Text PDFWe present a novel technique to generate microbubbles photothermally by continuous-wave laser irradiation of nanoporous gold disk (NPGD) array covered microfluidic channels. When a single laser spot is focused on the NPGDs, a microbubble can be generated with controlled size by adjusting the laser power. The dynamics of both bubble growth and shrinkage are studied.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!