scholarly journals Verification of an acoustic transmission matrix analysis of sound propagation in a variable area duct without flow

1981 ◽  
Vol 70 (S1) ◽  
pp. S6-S6
Author(s):  
J. H. Miles
Keyword(s):  
Sound Propagation ◽  
Matrix Analysis ◽  
Transmission Matrix ◽  
Acoustic Transmission

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 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.

scholarly journals Transmission matrix analysis of the chinchilla middle ear

2007 ◽  
Vol 122 (2) ◽  
pp. 932-942 ◽  
Author(s):  
Jocelyn E. Songer ◽  
John J. Rosowski
Keyword(s):  
Middle Ear ◽  
Matrix Analysis ◽  
Transmission Matrix

scholarly journals Spatio-spectral decomposition of complex eigenmodes in subwavelength nanostructures through transmission matrix analysis

Nanophotonics ◽  
2022 ◽  
Vol 0 (0) ◽  
Author(s):  
Young-Ho Jin ◽  
Juntaek Oh ◽  
Wonshik Choi ◽  
Myung-Ki Kim
Keyword(s):  
Near Field ◽  
Effective Means ◽  
Matrix Analysis ◽  
Mode Analysis ◽  
Excitation Wavelength ◽  
Plasmonic Nanostructures ◽  
Transmission Matrix ◽  
Electromagnetic Simulations ◽  
Value Decomposition ◽  
20 Nm

Abstract Exploiting multiple near-field optical eigenmodes is an effective means of designing, engineering, and extending the functionalities of optical devices. However, the near-field optical eigenmodes of subwavelength plasmonic nanostructures are often highly multiplexed in both spectral and spatial distributions, making it extremely difficult to extract individual eigenmodes. We propose a novel mode analysis method that can resolve individual eigenmodes of subwavelength nanostructures, which are superimposed in conventional methods. A transmission matrix is constructed for each excitation wavelength by obtaining the near-field distributions for various incident angles, and through singular value decomposition, near-field profiles and energy spectra of individual eigenmodes are effectively resolved. By applying transmission matrix analysis to conventional electromagnetic simulations, we clearly resolved a set of orthogonal eigenmodes of single- and double-slot nanoantennas with a slot width of 20 nm. In addition, transmission matrix analysis leads to solutions that can selectively excite specific eigenmodes of nanostructures, allowing selective use of individual eigenmodes.

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