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 20 of 54 for “"Ultrasonics"”.
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Biomedical ultrasonics, cavitation, and sonoporation
This thesis treats biomedical ultrasonics, cavitation and sonoporation. Focussed ultrasound surgery can heat tissue to a temperature that causes protein denaturation and coagulative necrosis. For high-resolution focused ultrasound microsurgery, high working frequencies are necessary. We …
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Topics in diffuse field ultrasonics
… 20kHz, the subject can be called Diffuse Field Ultrasonics. Here, three topics of Diffuse Field Ultrasonics are presented. The first concerns the identification of the Green’s function with the cross-correlation produced from a diffuse wave field. This has been termed Green’s Function Retrieval. …
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Polyelectrolyte multilayers for plasmonics and picosecond ultrasonics
This thesis investigates the application of polyelectrolyte multilayers in plasmonics and picosecond acoustics. The observed samples were fabricated by the spin-assisted layer-by-layer deposition technique that allowed a precise tuning of layer thickness in the range of few nanometers. The first …
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Medical ultrasonics: dynamic focusing in diagnostic imaging
The design and implementation of an ultrasonic dynamic focusing annular array system is described. The array is designed for use as a contact transducer and for eventual incorporation into the head of a real-time mechanical scanner.
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Enhancing biodiesel production from soybean oil using ultrasonics
… the second section of this study, the effect of ultrasonics on biodiesel production is studied by applying ultrasonics during transesterification reaction to the reactants, i.e., soybean oil and methanol, in the presence of sodium hydroxide as a catalyst. Ultrasonics are sound waves of a high …
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Damage evaluation in dimension limestone using nonlinear ultrasonics
… then nondestructively tested using nonlinear ultrasonics in the form of a non-collinear ultrasonic wave mixing approach. In addition, the test samples’ degradation of flexure strength due to damage accumulation caused by the exposure to increasing levels of temperature was also obtained using …
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The use of ultrasonics for characterising fats and emulsions
Ultrasonics has not found widespread use in the food industry, despite having considerable potential for characterising food materials. This is due to the complexity and diversity of food materials, the lack of suitable instrumentation and a poor understanding of how ultrasound interacts with many …
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Inference of moisture content in unsaturated media using ultrasonics
… which investigates the use of commercial ultrasonics to determine moisture content in geologic and similar materials. Transmission experiments were performed on two of the limiting extremes found in these types of media. In one, tests were made on moistened sand. In the other, fractured …
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Nondestructive Detection of Hollow Heart in Potatoes Using Ultrasonics
Ultrasonic techniques were used to detect hollow heart in potatoes nondestructively. Fifty Russet Burbank potatoes were evaluated physically and sonically. A pair of dry-coupling 50-kHz ultrasonic transducers were used to generate an ultrasonic pulse with a power level of 0.22 W for the test of …
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Remote detection of laser generated ultrasonics by fibre optic interferometer
… waveforms generated in laser induced ultrasonics.
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Ultrasonics studies of point defects in iron, aluminum-lithium, and gallium arsenide
The ultrasonics studies undertaken in this work illustrate the applicability of ultrasonics to a broad variety of problems. In the case of Fe, the objective is to measure the production and annealing of the diaelastic effect of self-interstitials in Fe. Frenkel Pairs created by 2.3 MeV electron …
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The Reliability of Manual Ultrasonics in Detecting Internal Corrosion Within Carbon Steel Pipework
Manual ultrasonics (MUT) is a non-destructive testing (NDT) technique used to detect wall thickness measurements on a variety of components within the oil and gas industry. This research aims to critically appraise the factors that affect the MUT task and apply the findings to make the necessary …
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In-situ cure monitoring and characterization of graphite/epoxy composites using fiber optics and ultrasonics
Advanced composites can be fabricated by laminating multiple plies into the desired shape, and then cured in an autoclave with simultaneous application of proper heat and pressure. The knowledge of the cure process is very important in order to obtain fully cured and high-quality composites. …
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INTELLIGENT NON-DESTRUCTIVE EVALUATION EXPERT SYSTEM FOR CARBON-CARBON COMPOSITES USING THERMOGRAPHY, ULTRASONICS, AND COMPUTED TOMOGRAPHY
This study develops a reliable intelligent non-destructive evaluation (NDE) expert system for carbon-carbon (C/C) composites based on thermography, ultrasonic, computed tomography and post processing by means of fuzzy expert system technique. Data features and NDE expert knowledge are seamlessly …
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Non-destructively detecting spinodal decomposition at a distance towards developing gigahertz ultrasonics for in-vessel inspection
… we demonstrate the use of gigahertz, non-contact ultrasonics to gauge the state of cast austenitic stainless steels (CASS), used in some of the largest components in LWR primary systems. We do so by linking changes in their surface acoustic wave (SAW) characteristics using transient grating …
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The application of ultrasonics to continuous liquid-liquid extraction by means of a cylindrical piezoelectric transducer
no abstract provided by author
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NDT to characterize 3D printed concrete interlayer bonds
… vibration resonance, and multi-element array ultrasonics) to idealized, layered concrete specimens that simulate layers of a 3D printed structure. The bond interfaces in the samples were characterized into well bonded, weakly bonded, and disbonded categories based on mechanical tests applied …
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A feasibility study of the acousto-ultrasonic technique to assure the quality of adhesively bonded sheet metal
… objective is to study the feasibility of Acousto-Ultrasonics (AU) as a nondestructive technique for assuring the quality of adhesively bonded sheet-metal used for automobiles. Other nondestructive (NDT) techniques were also applied viz., ultrasonics. radiography and thermography to supplement and …
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Optical characterization of complex mechanical and thermal transport properties
… with piezotransducer, ISS, and picosecond ultrasonics measurements to produce the first truly broadband mechanical spectra of a viscoelastic material covering frequencies continuously from mHz to hundreds of GHz. This allowed direct testing of the MCT predicted connection between fast and …
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Characterization of high temperature creep in siliconized silicon carbide using ultrasonic techniques
… of creep in Si/SiC and to determine if ultrasonics can be used in evaluating the severity of damage. The data indicated that both ultrasonic velocity and attenuation are directly related to creep strain and can be used in evaluating creep damage. Ultrasonic velocity was found to be …
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