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Piezoelectric transducersJanuary 1947 (has links)
Pt. 1. Electromechanical impedance matrix--Pt. 2. Electrical driving point impedance and admittance. / by W. Roth. / "July 3, 1947." / Includes bibliographical references. / Army Signal Corps Contract W36-039 sc-32037
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Measurements of Vp and Vs in dry, unsaturated and saturated sand specimens with piezoelectric transducersValle-Molina, Celestino, January 1900 (has links) (PDF)
Thesis (Ph. D.)--University of Texas at Austin, 2006. / Vita. Includes bibliographical references.
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Development of acoustic transducers for use in the parametric pumping of spin wavesGross, Jonah M. 07 March 2013 (has links)
The work detailed here is the development of simulations and fabrication techniques used for the construction of thin-film acoustic transducers for use in the parametric pumping of spin waves. The Mason Model, a 1-D equivalent circuit simulating the responses of multilayer acoustic transducers, is implemented using ABCD-parameters in MATLAB to determine the expected response from fabricated devices. The simulation is tested by varying device parameters and comparing the changes in device resonance response to those of prior published results. Three-layer thin-film acoustic transducers were also fabricated. These transducers use zinc oxide (ZnO) as a piezoelectric layer with aluminum (Al) electrodes. Construction is accomplished using the common thin-film fabrication techniques of sputtering, thermal evaporation, etching, and lift-off patterning processes. The response of the fabricated transducers is compared to that of the simulated response by observing the transducer's resonance frequency and characteristics. These results are used to validate the simulation and the transducer fabrication process. Finally, their usefulness for the design and fabrication of an acoustic spin wave amplification system is considered. / Graduation date: 2013
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Numerical analysis of the performance of staggered pin-fin micro heat exchangers /Choo, Jui Sheng. January 2003 (has links) (PDF)
Thesis (M.S. in Engineering Science)--Naval Postgraduate School, December 2003. / Thesis advisor(s): Ashok Gopinath. Includes bibliographical references (p. 83-84). Also available online.
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Underwater multimode directional transducer evaluation /Sineiro, Guilherme da Silva. January 2003 (has links) (PDF)
Thesis (M.S. in Engineering Acoustics)--Naval Postgraduate School, December 2003. / Thesis advisor(s): Thomas J. Hofler, Joseph A. Rice. Includes bibliographical references (p. 53-54). Also available online.
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Design, development and characterization of wideband polymer ultrasonic probes for medical ultrasound applications /Devaraju, Vadivel. Lewin, Peter A. January 2003 (has links)
Thesis (Ph. D.)--Drexel University, 2003. / Includes abstract and vita. Includes bibliographical references (leaves 140-146).
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Development of adaptive transducer based on biological sensory mechanismWangcharoenrung, Chayawee 28 August 2008 (has links)
Not available / text
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Measurements of Vp and Vs in dry, unsaturated and saturated sand specimens with piezoelectric transducersValle-Molina, Celestino 28 August 2008 (has links)
Not available / text
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Creating and Imaging Surface Acoustic Waves on GaAsMathew, Reuble 08 December 2009 (has links)
The versatility of surface acoustic wave (SAW) devices stems from the accessibility of the propagation path to modification and detection. This has led to the integration of SAWs in a variety of novel fields, including quantum information processing.
The development of technologically competitive devices requires the use of gigahertz frequency SAWs. This thesis develops fabrication processes for high frequency interdigital transducers on gallium arsenide. Optically lithography was used to create linear and stepped transducers, with a minimum feature size of 2 um, that were driven at their fifth harmonic. The highest frequency achieved was 1435 MHz, but the power absorbed was less than 3% and insertion losses were greater than -80 dB. Further improvements in the design and fabrication are required if optically fabricated transducers are to be an alternative to transducers with narrower finger widths. Electron-beam lithography techniques were developed and used to create transducers with finger widths of 500 and 400 nm, with fundamental resonance frequencies of 1387 and 1744 MHz, respectively. The power absorbed was 3 to 6% with insertion losses greater than -45 dB. The performance characteristics can be improved by the removal of residual resist on the surface of the transducer.
An indispensable tool for the characterization of one-port transducers is an all optical probe to measure the displacement field of a SAW. This work details the design and construction of a scanning Sagnac interferometer, that is capable of measuring the outward displacement of a surface. The spatial resolution of the interferometer was 2.4 +/- 0.2 um and the displacement sensitivity was determined to be 4 +/- 1 pm. The instrument was used to map the SAW displacement field from a 358 MHz transducer, with results showing the resonant cavity behaviour of the fingers due to Bragg reflections. It also allowed for the direct detection of the SAW amplitude as a function of the driving frequency of the transducer. The results showed good agreement with the related S21 scattering parameter. Lastly, the interferometer was used to image the attenuated propagation of SAWs through a phononic crystal. Results showed good agreement with theoretical simulations. / Thesis (Master, Physics, Engineering Physics and Astronomy) -- Queen's University, 2009-12-08 12:28:35.962
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Transducerless control and monitoring of induction machines by detection of magnetic saliency harmonicsHurst, Kevin D. 12 1900 (has links)
No description available.
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