Feasibility of High Frequency Acoustic Imaging for Inspection of Containments

Sub-bottom profiler is a kind of underwater acoustic imaging equipment. It can scan the sub-water stratums with acoustic signals and presents the section imaging. The frequency rang and transmitting power are key points to choice a suitable profiler. Generally, high frequency means high resolution and small imaging range. Transmitting power affects the imaging range also. Sub-bottom profiler can tell hydraulic and civil engineers what the embankments’ foundation like, especially the distribution of enrockments. With these information, engineers can evaluate the safety of embankments and decide what to do to keep them standing strong. A typical profiler called X-Star and a series of experiments carried on Yellow River, the famous sediment-laden and the 2nd longest river of China.

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High-frequency acoustic imaging of L Lake Phase 4 [Savannah River Site, South Carolina]

10.2172/770477 ◽

1997 ◽

Author(s):

D.L. Dunn ◽

Keith J. Sjostrom ◽

Rodney L. Leist ◽

Thomas S., Jr. Harmon

Keyword(s):

South Carolina ◽

High Frequency ◽

Savannah River Site ◽

Acoustic Imaging ◽

Savannah River ◽

River Site

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Acoustic Imaging of Defects in Flexible Food Packages

Journal of Food Protection ◽

10.4315/0362-028x-60.3.309 ◽

1997 ◽

Vol 60 (3) ◽

pp. 309-314 ◽

Cited By ~ 14

Author(s):

AMJAD A. SAFVI ◽

HAROLD J. MEERBAUM ◽

SCOTT A. MORRIS ◽

CAROL L. HARPER ◽

WILLIAM D. O'BRIEN

Keyword(s):

High Frequency ◽

Imaging System ◽

Major Axis ◽

Acoustic Imaging ◽

Acoustic Microscopy ◽

Mechanical Transmission ◽

Resolution Limit ◽

Food Packages ◽

Laminate Film ◽

Micrometer Scale

A study was conducted using a high-frequency acoustic imaging system: the scanning laser acoustic microscope (SLAM), operating at 100 MHz, to detect packaging defects to within the system's resolution limit of 20 μm. The purpose of the study was to assess the feasibility of high-frequency acoustic imaging to detect and classify channel defects that would have the potential for microbial contamination through visually undetected defects. The SLAM can characterize and image various materials and defects by exploiting the differences in acoustic (mechanical) transmission properties within different materials. Channel defects transverse to the heat-seal major axis were fabricated by sandwiching 10-, 16-, 25-, and 37-μm wire between two layers of either polyethylene or plastic retort-pouch laminate film which were then heat sealed. The wire was then pulled out, leaving a channel filled variously with saline solution, air, or both. The channel defects were then assessed using the SLAM and validated with confocal microscopy. The results indicate that the SLAM technology can readily detect channel defects as small as 10 μm, the smallest channel defects examined, which is one-half the imaging system stated resolution specification. This study has clearly demonstrated that acoustic microscopy can nondestructively image micrometer-scale channel defects in heat seals at and smaller than the SLAM's resolution limit.

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