A d'Alembert-based solution of forced wave motion with internal and boundary damping is presented with the specific intention of investigating the transient response. The dynamic boundary condition is a convenient method to model the absorption and reflection effects of an interface without considering coupled PDE's. Problems with boundary condition of the form [Formula: see text] are not self-adjoint which greatly complicates solution by spectral analysis. However, exact solutions are found with d'Alembert's method. Solutions are also derived for a time-harmonically forced problem with internal damping and are used to investigate the effect of ultrasound in a bioreactor, particularly the amount of energy delivered to cultured cells. The concise form of the solution simplifies the analysis of acoustic field problems.
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http://dx.doi.org/10.1063/1.3674316 | DOI Listing |
Transl Psychiatry
January 2025
Laboratory of Exercise and Neurobiology, School of Physical Education and Sports Science, South China Normal University, Guangzhou, 510006, Guangdong, China.
Repeated closed-head injuries (rCHI) from activities like contact sports, falls, military combat, and traffic accidents pose a serious risk due to their cumulative impact on the brain. Often, rCHI is not diagnosed until symptoms of irreversible brain damage appear, highlighting the need for preventive measures. This study assessed the prophylactic efficacy of remote photobiomodulation (PBM) targeted at the lungs against rCHI-induced brain injury and associated behavioral deficits.
View Article and Find Full Text PDFSci Rep
January 2025
Department of Psychiatry, New York State Psychiatric Institute, New York, NY, USA.
On October 7, 2023, a large-scale attack in southern Israel and the subsequent war resulted in extensive loss of life and injuries, with many individuals experiencing traumatic losses, such as family members or close friends being killed or kidnapped. This study aims to longitudinally examine its effects on mental health, specifically, clinical symptoms of anxiety, depression, and posttraumatic stress disorder (PTSD). We anticipated greater symptom severity among individuals who experienced traumatic loss, were forcibly displaced, or suffered income loss, as well as among women and members of ethnic minorities.
View Article and Find Full Text PDFNeuromuscul Disord
November 2024
Neuroimmunology and Neuromuscular Diseases Unit, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy. Electronic address:
J Vis
December 2024
Psychology Program, Division of Science, New York University Abu Dhabi, Abu Dhabi, UAE.
Chaos
December 2024
Research Group for Nonlinear Dynamics, Department of Physics, University of Science, Unjong-District, Pyongyang, Democratic People's Republic of Korea.
We consider the effects of an external periodic forcing on a spatially extended system that consists of identical phase oscillators coupled with transmission delays on a ring. Analyzing the continuum limit N→∞ of the model system along the Ott-Antonsen invariant manifold, we obtain the stability diagram for two regimes, called the forced and drifting entrainments. The former exhibits a spatially homogeneous solution trying to lock onto the drive, of which the stability boundary is rigorously determined.
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