Wave reflection from a sediment layer with depth‐dependent properties

1985 ◽  
Vol 77 (5) ◽  
pp. 1781-1788 ◽  
Author(s):  
M. Stern ◽  
A. Bedford ◽  
H. R. Millwater
Keyword(s):  
Wave Reflection ◽  
Sediment Layer

A simple ray model of plane‐wave reflection from a thin sediment layer

1993 ◽  
Vol 93 (4) ◽  
pp. 2395-2395
Author(s):  
David M. F. Chapman ◽  
N. Ross Chapman
Keyword(s):  
Plane Wave ◽  
Wave Reflection ◽  
Sediment Layer

Acoustic wave reflection from a rough seabed with a continuously varying sediment layer overlying an elastic basement

2004 ◽  
Vol 275 (3-5) ◽  
pp. 739-755 ◽  
Author(s):  
Jin-Yuan Liu ◽  
Sheng-Hsiung Tsai ◽  
Chau-Chang Wang ◽  
Chung-Ray Chu
Keyword(s):  
Acoustic Wave ◽  
Wave Reflection ◽  
Sediment Layer ◽  
Elastic Basement

A coherent ray model of plane‐wave reflection from a thin sediment layer

1993 ◽  
Vol 94 (5) ◽  
pp. 2731-2738 ◽  
Author(s):  
N. Ross Chapman ◽  
David M. F. Chapman
Keyword(s):  
Plane Wave ◽  
Wave Reflection ◽  
Sediment Layer

scholarly journals Wave reflection from a sediment layer with depth‐dependent properties

1983 ◽  
Vol 74 (S1) ◽  
pp. S43-S43 ◽  
Author(s):  
M. Stern ◽  
A. Bedford ◽  
H. R. Millwater
Keyword(s):  
Wave Reflection ◽  
Sediment Layer

On the Effect of 2-Layer Thickness by High-Specific Gravity Armor Blocks on Wave Reflection

1999 ◽  
Author(s):  
Masahiro Ito ◽  
Yuitch Iwagaki ◽  
Hiroshi Murakami ◽  
Kenji Nemoto ◽  
Masato Yamamoto ◽  
...  
Keyword(s):  
Specific Gravity ◽  
Layer Thickness ◽  
Wave Reflection ◽  
High Specific Gravity

Detection of delamination in composites by using electromagnetic penetrating radar

2014 ◽  
Vol 5 (2) ◽  
pp. 151-156
Author(s):  
Z. Mechbal ◽  
A. Khamlichi
Keyword(s):  
Electromagnetic Wave ◽  
Electromagnetic Waves ◽  
Electromagnetic Wave Propagation ◽  
Wave Reflection ◽  
Image Features ◽  
Partial Reflection ◽  
Straight Path ◽  
Reflected Signal ◽  
Short Time ◽  
Intervening Factors

Composites made from E-glass/epoxy or aramid/epoxy are frequently used in aircraft and aerospace industries. These materials are prone to suffer from the presence of delamination, which can reduce severely the performance of aircrafts and even threaten their safety. Since electric conductivity of these composites is rather small, they can propagate electromagnetic waves. Detection of delamination damage can then be monitored by using an electromagnetic penetrating radar scanner, which consists of emitting waves having the form of short time pulses that are centered on a given work frequency. While propagating, these waves undergo partial reflection when running into an obstacle or a material discontinuity. Habitually, the radar is moved at constant speed along a straight path and the reflected signal is processed as a radargram that gives the reflected energy as function of the two-way time and the antenna position.In this work, modeling of electromagnetic wave propagation in composites made from E-glass/epoxy was performed analytically. The electromagnetic wave reflection from a delamination defect was analyzed as function of key intervening factors which include the defect extent and depth, as well as the work frequency. Various simulations were performed and the obtained results have enabled to correlate the reflection pattern image features to the actual delamination defect characteristics which can provide quantification of delamination.

QUANTIFICATION OF TUNA FISH TARGET STRENGTH USING QUANTITATIVE ECHO SOUNDER

2009 ◽  
Vol 1 (1) ◽  
Author(s):  
Henry M. Manik
Keyword(s):  
Wave Reflection ◽  
Fork Length ◽  
Research Programme ◽  
Yellowfin Tuna ◽  
Target Strength ◽  
Bigeye Tuna ◽  
Tuna Fish ◽  
Thunnus Obesus ◽  
The Relationship ◽  
Echo Sounder

A preliminary research programme was carried out in order to study the acoustic wave reflection or target strength (TS) of tuna fish using a quantitative echo sounder (QES). The relationships between TS to fork length (FL) and swimbladder volume, for bigeye tuna (Thunnus obesus) and yellowfin tuna (T. albacares) are investigated. The TS of bigeye tuna was about 3 dB higher than yellowfin tuna when comparing species at the same size. The result can be correlated to the swimbladder volume differencebetween species. The relationship between TS and swimbladder volume was quantified for both species.Keywords: tuna fish, target strength, quantitative echo sounder

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