Speed of sound and geo-alpha in clayey silt derived from concurrent inversion of geo and bio-acoustic parameters from transmission loss data and co-located chirp sonar measurements

2018 ◽  
Vol 144 (3) ◽  
pp. 1960-1960
Author(s):  
Orest Diachok ◽  
Altan Turgut
Keyword(s):  
Speed Of Sound ◽  
Transmission Loss ◽  
Acoustic Parameters ◽  
Clayey Silt ◽  
Loss Data ◽  
Chirp Sonar

scholarly journals Statistical Patterns of Transmission Losses of Low-Frequency Sound in Shallow Sea Waveguides with Gaussian and Non-Gaussian Fluctuations

2019 ◽  
Vol 9 (9) ◽  
pp. 1841
Author(s):  
Fengqin Zhu ◽  
Oleg E. Gulin ◽  
Igor O. Yaroshchuk
Keyword(s):  
Acoustic Field ◽  
Speed Of Sound ◽  
Transmission Loss ◽  
Low Frequency ◽  
Local Mode ◽  
Average Intensity ◽  
Slowing Down ◽  
Gaussian Fluctuations ◽  
Mode Method ◽  
Non Gaussian

Based on the local mode method, the problem of the average intensity (transmission loss) behavior in shallow waveguides with losses in the bottom and fluctuations of the speed of sound in water is considered. It was previously shown that the presence in a waveguide with absorbing penetrable bottom of 2D random inhomogeneities of the speed of sound leads to the appearance of strong fluctuations in the acoustic field already at relatively small distances from the sound source. One of the most important and interesting manifestations of this is the slowing down of the average intensity of the acoustic field compared with a waveguide, which has no such random inhomogeneities of the speed of sound. This paper presents the results of a numerical analysis of the decay of the average field intensity in the presence of both Gaussian and non-Gaussian fluctuations in the speed of sound. It is shown that non-Gaussian fluctuations do not fundamentally change the conclusion about reducing losses during the propagation of a sound signal but can enhance this effect.

A Ternary Solution for Independent Acoustic Impedance and Speed of Sound Matching to Biological Tissues

1982 ◽  
Vol 4 (2) ◽  
pp. 163-170 ◽  
Author(s):  
Jonathan Ophir ◽  
Paul Jaeger
Keyword(s):  
Speed Of Sound ◽  
Acoustic Impedance ◽  
Soft Tissues ◽  
Sound Propagation ◽  
Biological Tissues ◽  
Liquid System ◽  
The Body ◽  
Acoustic Parameters ◽  
Wide Range

In applications requiring a liquid which is acoustically well matched to biological tissues, it is often difficult to find a material which is matched well in terms of both the acoustic impedance and speed of sound propagation in it; changing one parameter invariably affects the other. A three component liquid system is described, which allows independent adjustment of these two acoustic parameters over a wide range. This range encompasses the soft tissues of the body. Results of parameter measurements are presented in the form which allows simple determination of the mixture required to match any combination of acoustic impedance and speed of sound propagation over a given range.

Contrast Agents for Ultrasonic Diagnosis: A New Arena for Pharmacy

1989 ◽  
Vol 2 (3) ◽  
pp. 171-176
Author(s):  
Allan H. Gobuty
Keyword(s):  
Contrast Agents ◽  
Speed Of Sound ◽  
Medical Diagnosis ◽  
Ultrasonic Diagnosis ◽  
Background Information ◽  
Acoustic Parameters ◽  
Ultrasound Waves ◽  
Ultrasound Contrast ◽  
Further Development ◽  
Physical Principles

The use of contrast agents for ultrasonic diagnosis has been an elusive goal since the first experimental report of the successful use of gas bubbles in echocardiology in 1968. Included here is background information about the place of ultrasound in medical diagnosis, physical principles of ultrasound contrast, and examples of substances that have been used in an effort to achieve this goal. Reflection of ultrasound waves occurs to some extent in all tissues. Production of usefut reflected pulses most often results when structures with different acoustic impedances are separated by a discrete interface. One way in which contrast agents can facilitate production of such an interface is when they are taken up in higher concentrations in one tissue or organ than in an adjacent one. The principal acoustic parameters of tissue which may be influenced by the introduction of contrast agents are backscatter, attenuation, and speed of sound. The most important effect of contrast agents in imaging at present is the enhancement of backscatter. While there has been some progress in the use of these substances, their further development will depend upon successfully recruiting those who possess training in allied disciplines, such as pharmacy, toxicology, ultrasound physics and experimental techniques.

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