An efficient method is proposed to solve the multimodal wave propagation within a three-dimensional waveguide bounded by a hard wall with varying cross section and curvature. This is achieved by first turning the original problem, in a complex-shaped waveguide, into a cylindrical waveguide with unit radius, by means of an adapted and flexible geometrical transformation. Then supplementary modes are defined to enrich the standard modal basis that is usually considered in such methods and to help restore the right boundary condition. It is shown through various numerical applications that the introduction of these supplementary modes, whatever the complexity of the waveguide geometry, significantly enhances the multimodal method, notably by increasing its convergence rate, whether one's aim is to solve the wavefield or the scattering problem.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1121/10.0003336 | DOI Listing |
Biomater Adv
January 2025
Department of Ultrasound, Xijing Hospital, Fourth Military Medical University, No.127 Changle West Rd, 710032 Xi'an, Shaanxi, China. Electronic address:
Purpose: The objective of this study is to elucidate the sensitizing effect of mesoporous silica nanoparticles (MSNs) on shear wave elastography (SWE) and to investigate the potential application of MSNs as a sensitizer to enhance the sensitivity of SWE in the diagnosis of metabolic-associated steatohepatitis (MASH).
Materials And Methods: The in vitro gelatin models with varying ratios were assessed using SWE to identify the gelatin ratio that most closely approximates with human liver stiffness. Following the characterization of the dispersion properties of MSNs, in vitro models incorporating MSNs of different particle sizes were developed.
Phys Med Biol
January 2025
Department of Electrical and Electronic Engineering, The University of Hong Kong, Chow Yei Ching 506, Hong Kong, 999077, HONG KONG.
. The propagation speed of a shear wave, whether externally or internally induced, in biological tissues is directly linked to the tissue's stiffness. The group shear wave speed (SWS) can be estimated using a class of time-of-flight (TOF) methods in the time-domain or phase speed-based methods in the frequency domain.
View Article and Find Full Text PDFHeliyon
December 2024
Laser and Plasma Research Institute, Shahid Beheshti University, Tehran, 1983969411, Iran.
In this article, the propagation of high-frequency (HF) plane electromagnetic waves through the lower ionosphere is numerically investigated using the real geometry of the Earth's magnetic field in the northern hemisphere. For this purpose, the profiles of electron density and the collision frequency in the layers of the lower ionosphere (D- and E-region) are considered using the reported experimental data for day and night. The reflection, transmission, and absorption coefficients of HF radio waves in the frequency range of 3 to 30 MHz are calculated in the ionosphere plasma.
View Article and Find Full Text PDFLab Chip
January 2025
Key Laboratory of Biomedical Engineering of Ministry of Education, Department of Biomedical Engineering, Zhejiang University, Hangzhou, 310027, China.
The utilization of acoustic fields offers a contactless approach for microparticle manipulation in a miniaturized system, and plays a significant role in medicine, biology, chemistry, and engineering. Due to the acoustic radiation force arising from the scattering of the acoustic waves, small particles in the Rayleigh scattering range can be trapped, whilst their impact on the acoustic field is negligible. Manipulating larger particles in the Mie scattering regime is challenging due to the diverse scattering modes, which impacts the local acoustic field.
View Article and Find Full Text PDFSci Rep
January 2025
China University of Mining and Technology (Beijing), Beijing, 100083, China.
This study aims to evaluate the efficiency and energy release characteristics of different types of coal in pulse detonation engines (PDE) to advance the development of deep coal fluidization detonation technology, achieving more efficient and cleaner coal utilization. Using a custom PDE setup, experiments were conducted with four coal types at mass flow rates from 30 to 120 g/s. High-frequency pressure sensors assessed pressure dynamics and detonation wave propagation, complemented by numerical simulations for accuracy.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!