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 113 for “"acoustic properties"”.
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Investigating Acoustic Properties of Biocomposite from Waste Streams
… elements on the material and mechanical properties are analyzed and modeled. These properties as a function of the composition were characterized to advances value-added product from waste streams. The biofibre used in this study is from crop residue (agricultural straw: hemp) which is …
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The study of acoustic properties of P205-doped silica fiber
… to numerous fields. The interactions between acoustic phonons and the optical wave are involved in several of these applications. A significant stimulated scattering mechanism observed is stimulated Brillouin scattering (SBS), resulting in strong backward scattering typically within the …
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Material and Acoustic Properties of Swimbladders of Tilapia and Channel Catfish
Acoustically, teleost swimbladders have been considered resonant underwater bubbles. Contrary results indicating that bladders are tuned less sharply than such a bubble have been explained by damping of surrounding fish tissue. Recent findings in toadfish and weakfish, however, suggest that the …
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Mechanical, thermal and acoustic properties of rubberised concrete incorporating nano silica
… (RuC) with nano silica (NS) and addressed the acoustic benefits of rubberised concrete. The current research investigates the effect of incorporating colloidal nano silica on the mechanical, thermal and acoustic properties of Rubberised concrete and compares them with normal concrete (NC). Two …
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Using two-dimensional impedance maps to study acoustic properties of tissue microstructure
… represents a set of techniques for estimating acoustic properties of tissue microstructure that have confirmed potential for identifying disease and monitoring therapy. In one approach to QUS, the backscatter coefficient (BSC) from a tissue is utilized to quantify and classify tissue state. The …
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Physical and acoustic properties of petroleum and renewable based polyurethane foam filled with shorea leprosula
Physical and acoustic properties of petroleum-based polyurethane (PU) and renewable based polyurethane (RPU) foam composites filled with Shorea Leprosula (Red Meranti) fiber filler has been investigated. Shorea Leprosula wood dust namely as SL was used as the filler. RPU was used with hope to …
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Characterizing The Acoustic Properties Of The Jet Lab At The National Center For Physical Acoustics
… frequencies the National Center for Physical Acoustics' Jet Lab Facility is non-anechoic, semi-anechoic, or anechoic. To comply with the guidelines of ISO 3745- 1977, three sources were designed and tested at frequencies from 25 Hz to 16000 Hz. The voltages were acquired at each frequency to …
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Characterization and modeling of the stress and pore-fluid dependent acoustic properties of fractured porous rocks
… has uncovered several important aspects of the acoustic properties of reservoir rocks through experimentation and modeling. The thesis presents the results of a study of the characterization and modeling of the stress and pore-fluid dependent acoustic properties of fractured porous rocks. A new …
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Study of the organic content and mineralogy effects on the acoustic properties of the Niobrara Formation, Denver Basin
… clay content and kerogen maturity levels on the acoustic properties of Niobrara chalk and marl intervals. Core samples from Gill Land Associates 2 and Berthoud State 3 wells were analyzed for total organic content richness and maturity. Compressional and shear ultrasonic velocities were measured …
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A study of vowels /ɛ/ and /ɪ/ in African American English and standard American English
… the Detroit, Michigan area. I first analyzed the acoustic properties of a number of speech samples to determine vowel quality and duration measurements. I then performed speech perception tests using the same speech samples. My analyses support and contradict claims about AAE and SAE, particularly …
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An inverse method for obtaining the attenuation profile and small variations in the sound speed and density profiles of the ocean bottom
The acoustic properties of marine sediments have a direct effect on the propagation of sound in the ocean. In the frequency range of interest (50 - 500 Hz) the sediment can be modelled as a fluid. Assuming horizontal stratification of the ocean bottom, the acoustic parameters of interest are the …
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Infant-directed speech in African-American mothers
… mothers; (2) examine the differences in the acoustic properties of the infant- and adult-directed speech of European American and African American mothers; (3) examine the relationship between the acoustic properties of mothers' infant directed speech and the responsiveness of their infants. …
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Performance optimization of lateral-mode thin-film piezoelectric-on-substrate resonant systems
… mechanism while taking advantage of superior acoustic properties of a substrate. The use of lateral-mode TPoS designs allows for fabrication of dispersed-frequency filters on a single substrate, thus significantly reducing the size and manufacturing cost of devices. TPoS filters also offer a …
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A Performance Interpretation of the Concerto in E Flat Major by Joseph Haydn Based on Contemporaneous Writings and Period Performance Practice
… understanding of the historical background and acoustic properties of the keyed trumpet as well as the implications of structure, aesthetics, and period conventions of performance in the development of a personal interpretation of Haydn's trumpet concerto. In addition, the idiomatic features of …
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