The purpose of the work reported here is to further experimentally explore the wide variety of behaviors exhibited by driven vibrating wires, primarily in the nonlinear regime. When the wire is driven near a resonant frequency, it is found that most such behaviors are significantly affected by the splitting of the resonant frequency and by the existence of a "characteristic" axis associated with each split frequency. It is shown that frequency splitting decreases with increasing wire tension and can be altered by twisting. Two methods are described for determining the orientation of characteristic axes. Evidence is provided, with a possible explanation, that each axis has the same orientation everywhere along the wire. Frequency response data exhibiting nonlinear generation of transverse motion perpendicular to the driving direction, hysteresis, linear generation of perpendicular motion (sometimes tubular), and generation of motion at harmonics of the driving frequency are exhibited and discussed. Also reported under seemingly unchanging conditions are abrupt large changes in the harmonic content of the motion that sometimes involve large subharmonics and harmonics thereof. Slow transitions from one stable state of vibration to another and quasiperiodic motions are also exhibited. Possible musical significance is discussed.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1121/1.1828511 | DOI Listing |
Sci Rep
January 2025
College of Engineering and Information Technology, Aljanad University of Science and Technology, Taiz, Yemen.
Low-frequency oscillations (LFO) are inherent to large interconnected power systems. Timely detection and mitigation of these oscillations is essential to maintain reliable power system operation. This paper presents a methodology to identify and mitigate low-frequency oscillations ( forced and inter-area) using a wide area monitoring system (WAMS) based power system model utilizing phasor measurement units (PMUs).
View Article and Find Full Text PDFNat Commun
January 2025
Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, China.
Harmonic generation, a notable non-linear phenomenon, has promising applications in information processing. For spin-waves in ferromagnetic materials, great progress has been made in the generation higher harmonics, however probing the coherence of these higher harmonics is challenging. Here, using in-situ diamond sensors, we study the coherent harmonic generation of spin waves in a soft ferromagnet.
View Article and Find Full Text PDFLight Sci Appl
January 2025
Department of Electrical Engineering, City University of Hong Kong, Kowloon, Hong Kong SAR, China.
Combining bright-field and edge-enhanced imaging affords an effective avenue for extracting complex morphological information from objects, which is particularly beneficial for biological imaging. Multiplexing meta-lenses present promising candidates for achieving this functionality. However, current multiplexing meta-lenses lack spectral modulation, and crosstalk between different wavelengths hampers the imaging quality, especially for biological samples requiring precise wavelength specificity.
View Article and Find Full Text PDFJ Am Acad Child Adolesc Psychiatry
January 2025
ISGlobal, Barcelona, Spain; Universitat Pompeu Fabra (UPF), Barcelona, Spain; Spanish Consortium for Research on Epidemiology and Public Health (CIBERESP), Carlos III Health Institute, Madrid, Spain; Erasmus University Medical Center, Rotterdam, The Netherlands; ICREA, Barcelona, Spain. Electronic address:
Objective: Exposure to extreme temperatures has been linked to acute mental-health events in young populations, but the underlying neural mechanisms are not well understood. Resting-state functional magnetic resonance imaging allows for the assessment of connectivity patterns in brain functional networks, which have been associated with mental-health disorders. We investigated the short-term effects of ambient temperature on functional connectivity of brain resting-state networks in preadolescents.
View Article and Find Full Text PDFJ Clin Neurosci
January 2025
The Walton Centre NHS Foundation Trust, Lower Lane, Fazakerley, Liverpool L9 7LJ UK; Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Liverpool, UK.
Ganglioglioma is a rare primary brain tumour that most frequently occurs in children and young adults. They are generally low-grade and have a favourable prognosis, but there is limited literature to guide the optimal management. The aim of this study was to investigate the clinical outcomes of adults with intracranial ganglioglioma, and to determine the frequency and duration of radiological follow-up.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!