Subbottom Profiling of a Sand Capped Disposal Mound

Understanding Discrete Fracture Growth in Rock by Interpreting Acoustic Emissions

Field Performance of an Acoustic Scour-Depth Monitoring System
The Herbert C. Bonner Bridge over Oregon Inlet serves as the only land link between Bodie and Hatteras Islands, part of the Outer Banks of North Carolina. Periodic soundings over the past...

NDE of Steel Bridges by Acoustic Emission
Acoustic emission technique (AE) was used to investigate fatigue cracking phenomenon during a series of laboratory tests of various bridge steels and during field testing of an in-service...

Conceptual Design of a Monitoring System for Maglev Guideways
The state-of-the-art in nondestructive testing (NDT) technology has advanced significantly over the past fifteen years and has reached a stage where continuous monitoring of structures...

Signal Analysis for Quantitative AE Testing
Quantitative acoustic emission (AE) techniques can be used to monitor crack growth and to deduce microfracture mechanisms in quasi-brittle materials. Multichannel data acquisition systems...

Acoustic Emission Monitoring of Stressed Composite Bars
In this study, Acoustic Emission (AE) technique is used to monitor the behavior of composite bars subjected to direct tension. Aramid Fiber Reinforced Plastics (AFRP) bars were loaded...

Application of Acoustic Hydrosurvey Technology to the Mapping of Eelgrass (Zostera marina) Distribution in Humboldt Bay, California
Acoustic hydrosurvey technology provides an efficient and accurate means of surveying the distribution of submerged aquatic vegetation under some circumstances. The San Francisco District,...

Visualization and Analysis of Multi-Dimensional Velocity Measurements in Carquinez Strait, California
On 11 March, 12 March, 15 April, and 16 April, 1991 the United States Geological Survey (USGS), Sacramento, CA, employed a Downward Looking Acoustic Doppler Current Profiler (DL-ADCP)...

Acoustic Doppler Current Profiler for Inlet Current Measurements
A BroadBand Acoustic Doppler Current Profiler (BroadBand ADCP) was used to survey tidal currents at Shinnecock and Moriches Inlets, Long Island, NY. Measurements were made remotely form...

Long Term Hydroacoustic Evaluations of a Fixed In-Turbine Fish Diversion Screen at Rocky Reach Dam on the Columbia River, Washington

Comparison of Hydroacoustic and Net Catch Estimates of Fish Entrainment at Tower and Kleber Dams, Black River, Michigan

Acoustic Flow Measurements at the Rocky Reach Dam

An Acoustic Impedance Method for Subbottom Material Characterization

Passive Acoustic Emission for Quantitative Evaluation of Freeze Thaw and Alkali Aggregate Reaction in Concretes
Several experiments are reported in which the progression of freeze thaw (FT), alkali-aggregate reaction (AAR), and internal cracking caused by mechanical loading were monitored using...

Damage Assessment in Concrete Using Acoustic Emission
An acoustic emission (AE) is a localized rapid release of strain energy in a stressed material. This energy release causes stress waves to propagate through the specimen. These acoustic...

Study of Three Dimensional Crack Tip Location of Mortar by Acoustic Emission
Plain mortar specimens were tested under three-point bending. Experimental variables include the width of the specimen and the notch-to-depth ratio. The experimental results of 12 specimens...

Nondestructive Crack Identification by Acoustic Emission Analysis and Ultrasonic Frequency Response
Nondestructive evaluation (NDE) by the acoustic emission (AE) analysis and the ultrasonic testing (UT) on the spectral (frequency) response is studied to identify crack geometry. AE waveform...

Experimental Determination of the Relation Between the Damaged Zone and the Aggregate Size in Concrete Through Acoustic and Mechanical Techniques
The size of aggregates in concrete has an influence on the behavior of the material. The width of the localized band can be related to this characteristic. Different experimental techniques...

Determination of In-Situ Stresses From Acoustic Emissions
Acoustic emissions (AE) are microseismic activities that are generated in concrete by cracking and damage. The rate of Acoustic Emissions, called the 'Event Rate', can provide indication...

 

 

 

 

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