Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 18 of 18 for “"Acoustic microscopy"”.
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Signal processing and image reconstruction for scanning tomographic acoustic microscopy
… of resolution and noise in the Scanning Laser Acoustic Microscope (SLAM). The SLAM was developed for high-resolution, real-time imaging in biomedical tissue analysis and nondestructive testing. Because of diffraction and the overlapping of depth planes, the SLAM is limited in its ability to …
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Asymptotic description of the acoustic microscopy of a surface-breaking crack
An asymptotic description of the acoustic signature of a crack, breaking the surface of an otherwise homogeneous, isotropic elastic material, determined using either a line focus or a point focus scanning acoustic microscope is constructed. The incident focused beam is constructed as a Fourier …
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Closure integrity testing of heat sealed aseptic packaging using scanning acoustic microscopy
… and shelf-stable food products. A scanning acoustic microscope (SAM), Olympus UH-3, and image analysis system were used to establish the operational parameters to ultrasonically inspect the heat seal closure of various flexible packages. The frequency range, attenuation, and focal length …
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Ultrasonic Characterization of Human Coronary Arteries and Atherosclerotic Plaques
… of human coronary arteries to date. An acoustic microscopy system was developed, refined, and tested for the purposes of acquiring data from fresh: that is, not chemically fixed) coronary artery tissues and atherosclerotic plaques. Novel methods of preparing samples, imaging samples, and …
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Predicting mechanical performance of adhesively bonded joints based on acousto-ultrasonic evaluation and geometric weighting
… describes work that addresses this situation. Acoustic microscopy has been used to provide a detailed image of the bonded joint, while acousto-ultrasonic measurements have been used to evaluate the stress transfer capability of modified lap shear joints. Knowledge of the stress distribution in …
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Effect of cooling rate and stacking sequence on the fatigue behavior of notched quasi-isotropic APC-2 laminates
… enhanced X-ray radiography, and Scanning Acoustic Microscopy (SAM). Post failure analysis of the specimens was carried out by Scanning Electron Microscopy (SEM). A quasi-3D Finite Element Analysis was performed to compare the differences in the interlaminar stresses arising around the …
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Stress and fatigue analysis of SVI-tested camshaft lobes
… for an equivalent of 100,000 miles. Optical microscopy, acoustic microscopy (SAM), and profilometry were used to characterize wear and fatigue, crack depth, and surface roughness, respectively. Results show cracking to occur mainly in the opening ramp of the most abusively ground cam lobes. …
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Advanced Electron-Beam Techniques for Solar Cell Characterization
… of the subsurface imaging of scanning electron acoustic microscopy (SEAM) was utilized to characterize the structural properties of saw-damage-induced defects and the non-destructive nature of SEAM could enable accurate optimization of saw-damage etch process duration. SEAM was also employed …
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Thermoplastic composite consolidation
… using different processing cycles. Optical microscopy and scanning acoustic microscopy were used to obtain the degree of intimate contact data. Agreement between the measured and calculated degree of intimate contact was good. A finite element model was developed to analyze residual stresses …
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Characteristics of blood vessel wall and atherosclerosis using high frequency ultrasound signals
… ultrasound imaging, elastography and acoustic microscopy have been applied for atherosclerosis diagnosis. The focus of this thesis was to develop data-acquisition and processing techniques for high frequency (50 Mhz) focused ultrasound probe to characterize small tissue specimens such …
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Modeling, design, fabrication and reliability characterization of ultra-thin glass BGA package-to-board interconnections
… techniques such as confocal surface acoustic microscopy (C-SAM), optical microscopy, X-ray imaging, and scanning electron microscopy/energy dispersive spectrometry (SEM/EDS). Model-to-experiment correlation was performed to validate the effectiveness of polymer collars as a …
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Non-destructive evaluation of solder joint reliability
… crack plane is captured and tracked using acoustic microscopy imaging (AMI). The feasibility of this concept was successfully demonstrated by employing the measurement technique in combination with Finite Element Analysis (FEA) to study the impact of component floor plan layout on the …
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Through-Life Monitoring of the impact of vibration on the reliability of area array packages using Non- Destructive Testing
… array packages (flip chips in particular) using acoustic micro imaging for through life monitoring of the solder joints. Since real time vibration on solder joints have not been studied before, the various steps for successful testing, through life monitoring of the solder joints and data …
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Oscillating Aqueous Gels as Drug Delivery Systems
… drug components. Optical and polarized light microscopy images were used to determine the structure and texture of each aqueous gel, and they have indicated cubic liquid crystal structures for the oscillating systems. To further characterize the microstructure and rheological properties of the …
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The effect of environmental aging/exposure on the durability of high performance polymeric composites
… enhanced x- radiography, scanning electron microscopy (SEM), and scanning acoustic microscopy (SAM). The chemical aging/degradation was seen to be sensitive to the oxygen partial pressure in the aging environment. The greater the amount of oxygen in the aging environment, the more the loss …
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Processing and Reliability Assessment of Solder Joint Interconnection for Power Chips
… joints were examined using scanning electron microscopy (SEM) and energy dispersive X-ray analysis (EDX) for the integrity of the joint. Acoustic microscopy imaging (nondestructive evaluation) was utilized to examine the quality of the bonded interfaces and to detect cracks and other defects …