Method of emitting very low frequency high power acoustic waves, and corresponding transducers therefor

1997 ◽  
Vol 101 (6) ◽  
pp. 3230
Author(s):  
A. A. Scarpitta
Keyword(s):  
High Power ◽  
Acoustic Waves ◽  
Low Frequency ◽  
Very Low Frequency

scholarly journals The Sonification of Solar Harmonics (SoSH) Project

2019 ◽  
Author(s):  
Seth Shafer ◽  
Timothy Larson ◽  
Elaine di Falco
Keyword(s):  
Acoustic Waves ◽  
Resonant Cavity ◽  
Low Frequency ◽  
Musical Instrument ◽  
The Sun ◽  
Very Low Frequency ◽  
Musical Compositions ◽  
Oscillation Modes

The Sun is a resonant cavity for very low frequency acoustic waves, and just like a musical instrument, it supports a number of oscillation modes, also commonly known as harmonics. We are able to observe these harmonics by looking at how the Sun’s surface oscillates in response to them. Although this data has been studied scientifically for decades, it has only rarely been sonified. The Sonification of Solar Harmonics (SoSH) Project seeks to sonify data related to the field of helioseismology and distribute tools for others to do the same. Creative applications of this research by the authors include musical compositions, installation artwork, a short documentary, and a full-dome planetarium experience.

The Attenuation of Very Low Frequency Brain Oscillations in Transitions from a Rest State to Active Attention

2009 ◽  
Vol 23 (4) ◽  
pp. 191-198 ◽  
Author(s):  
Suzannah K. Helps ◽  
Samantha J. Broyd ◽  
Christopher J. James ◽  
Anke Karl ◽  
Edmund J. S. Sonuga-Barke
Keyword(s):  
Brain Activity ◽  
Sampling Rate ◽  
Low Frequency ◽  
Future Research ◽  
Adhd Symptoms ◽  
Default Mode ◽  
Very Low Frequency ◽  
Wide Range ◽  
Interference Hypothesis ◽  
Mode Interference

Background: The default mode interference hypothesis ( Sonuga-Barke & Castellanos, 2007 ) predicts (1) the attenuation of very low frequency oscillations (VLFO; e.g., .05 Hz) in brain activity within the default mode network during the transition from rest to task, and (2) that failures to attenuate in this way will lead to an increased likelihood of periodic attention lapses that are synchronized to the VLFO pattern. Here, we tested these predictions using DC-EEG recordings within and outside of a previously identified network of electrode locations hypothesized to reflect DMN activity (i.e., S3 network; Helps et al., 2008 ). Method: 24 young adults (mean age 22.3 years; 8 male), sampled to include a wide range of ADHD symptoms, took part in a study of rest to task transitions. Two conditions were compared: 5 min of rest (eyes open) and a 10-min simple 2-choice RT task with a relatively high sampling rate (ISI 1 s). DC-EEG was recorded during both conditions, and the low-frequency spectrum was decomposed and measures of the power within specific bands extracted. Results: Shift from rest to task led to an attenuation of VLFO activity within the S3 network which was inversely associated with ADHD symptoms. RT during task also showed a VLFO signature. During task there was a small but significant degree of synchronization between EEG and RT in the VLFO band. Attenuators showed a lower degree of synchrony than nonattenuators. Discussion: The results provide some initial EEG-based support for the default mode interference hypothesis and suggest that failure to attenuate VLFO in the S3 network is associated with higher synchrony between low-frequency brain activity and RT fluctuations during a simple RT task. Although significant, the effects were small and future research should employ tasks with a higher sampling rate to increase the possibility of extracting robust and stable signals.

VLF/LF (Very Low Frequency/Low Frequency) Reflection Properties of the Low Latitude Ionosphere

1988 ◽  
Author(s):  
Wayne I. Klemetti ◽  
Paul A. Kossey ◽  
John E. Rasmussen ◽  
Maria Sueli Da Silveira Macedo Moura
Keyword(s):  
Low Frequency ◽  
Low Latitude ◽  
Very Low Frequency ◽  
Low Latitude Ionosphere
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