scholarly journals Inversion of surficial sediment thickness from under-ice acoustic transmission measurement

2021 ◽  
Vol 149 (1) ◽  
pp. 371-385
Author(s):  
Nicholas P. Chotiros ◽  
Gaute Hope ◽  
Espen Storheim ◽  
Halvor Hobaek ◽  
Lee Freitag ◽  
...  
Keyword(s):  
Surficial Sediment ◽  
Transmission Measurement ◽  
Acoustic Transmission ◽  
Sediment Thickness

scholarly journals Estimation of surficial sediment thickness using mid-frequency ocean acoustic bottom reflected signals measured in shallow water off Geoje island

2016 ◽  
Vol 35 (6) ◽  
pp. 419-426
Author(s):  
Hyuckjong Kwon ◽  
Jee Woong Choi ◽  
Su-Uk Son ◽  
Sungho Cho ◽  
Jooyoung Hahn ◽  
...  
Keyword(s):  
Shallow Water ◽  
Surficial Sediment ◽  
Sediment Thickness

scholarly journals Pneumothorax effects on pulmonary acoustic transmission

2015 ◽  
Vol 119 (3) ◽  
pp. 250-257 ◽  
Author(s):  
Hansen A. Mansy ◽  
Robert A. Balk ◽  
William H. Warren ◽  
Thomas J. Royston ◽  
Zoujun Dai ◽  
...  
Keyword(s):  
Sound Propagation ◽  
Human Subjects ◽  
Sound Transmission ◽  
Transmission Measurement ◽  
Sound Waves ◽  
Acoustic Transmission ◽  
Lung Collapse ◽  
Breath Sounds ◽  
Before And After ◽  
Threatening Condition

Pneumothorax (PTX) is an abnormal accumulation of air between the lung and the chest wall. It is a relatively common and potentially life-threatening condition encountered in patients who are critically ill or have experienced trauma. Auscultatory signs of PTX include decreased breath sounds during the physical examination. The objective of this exploratory study was to investigate the changes in sound transmission in the thorax due to PTX in humans. Nineteen human subjects who underwent video-assisted thoracic surgery, during which lung collapse is a normal part of the surgery, participated in the study. After subjects were intubated and mechanically ventilated, sounds were introduced into their airways via an endotracheal tube. Sounds were then measured over the chest surface before and after lung collapse. PTX caused small changes in acoustic transmission for frequencies below 400 Hz. A larger decrease in sound transmission was observed from 400 to 600 Hz, possibly due to the stronger acoustic transmission blocking of the pleural air. At frequencies above 1 kHz, the sound waves became weaker and so did their changes with PTX. The study elucidated some of the possible mechanisms of sound propagation changes with PTX. Sound transmission measurement was able to distinguish between baseline and PTX states in this small patient group. Future studies are needed to evaluate this technique in a wider population.

Nearshore surficial sediment textures; Beaufort Sea, Alaska

1980 ◽  
Author(s):  
Peter W. Barnes ◽  
Erk Reimnitz ◽  
Robin Ross
Keyword(s):  
Beaufort Sea ◽  
Surficial Sediment

Tunable asymmetric acoustic transmission via binary metasurface and zero-index metamaterials

2021 ◽  
Vol 118 (11) ◽  
pp. 113501
Author(s):  
Zhongming Gu ◽  
Xinsheng Fang ◽  
Tuo Liu ◽  
He Gao ◽  
Shanjun Liang ◽  
...  
Keyword(s):  
Acoustic Transmission ◽  
Zero Index

scholarly journals High-amplitude sound propagation in acoustic transmission-line metamaterial

2021 ◽  
Vol 118 (10) ◽  
pp. 104102
Author(s):  
Jiangyi Zhang ◽  
Vicente Romero-García ◽  
Georgios Theocharis ◽  
Olivier Richoux ◽  
Vassos Achilleos ◽  
...  
Keyword(s):  
Transmission Line ◽  
Sound Propagation ◽  
High Amplitude ◽  
Acoustic Transmission

scholarly journals Sound Velocity Estimation of Seabed Sediment Based on Parametric Array Sonar

2020 ◽  
Vol 2020 ◽  
pp. 1-6
Author(s):  
Jingxin Ma ◽  
Haisen Li ◽  
Jianjun Zhu ◽  
Baowei Chen
Keyword(s):  
Parameter Estimation ◽  
Acoustic Parameter ◽  
Velocity Estimation ◽  
Parameters Estimation ◽  
Real Field ◽  
Sound Waves ◽  
Sediment Thickness ◽  
Seafloor Topography ◽  
Seabed Sediment ◽  
Seabed Sediments

Backscattered sound waves of seabed sediments are important information carriers in seafloor detection and acoustic characteristic parameters inversion. Most of the existing methods for estimating geoacoustic parameters are based on multiangle seabed backscattered signal processing and suitable for flat seafloor conditions with uniform sediment thickness. This usually deviates from the real field conditions and affects the accuracy of parameter estimation. In this paper, the sound ray propagation theory is studied and analysed under the condition of sloping seabed and uneven sediment thickness. Based on the phased parameter array sonar system, a method of acoustic parameters estimation of the sediment under inclined seabed conditions is proposed. The simulation results show that the new method shows good adaptability to different inclination angles of the seabed and solves the problem of accuracy of acoustic parameter estimation of the inclined seabed sediments. The model will greatly reduce the seafloor topography requirements in the sediment acoustic parameter inversion, such as velocity, layer thickness, and acoustic impedance.

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