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 42 for “"Piezoelectric Transducer"”.
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Time and frequency domain modelling of the piezoelectric transducer
A new model for piezoelectric ultrasonic transducers is proposed. Using a systems engineering approach, the concept of feedback is used to explain secondary piezoelectric effects and to clearly describe electro-mechanical interaction. The model is derived from the fundamental piezoelectric …
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Bending mechanism for piezoelectric transducer footstep energy harvesting using piezoelectric tile
… that have been exhausted in these few decades. Piezoelectric material that has been widely used in sensor technologies is able to produce electrical energy from mechanical energy. Therefore, this transducer can be used to harvest the wasted mechanical energy from human body action. Many …
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Modeling of elastic wave propagation in a fluid-filled borehole excited by a piezoelectric transducer.
Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Earth, Atmospheric, and Planetary Sciences, 1991.
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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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Magnetoelectric Laminates with Novel Properties for Sensor, Transmitter, and Gyrator Applications
… composites consisting of magnetostrictive and piezoelectric materials have been developed that show remarkable ME voltage/charge coefficients. This extrinsic ME effect is achieved by using mechanical coupling as a medium between the magnetostrictive and piezoelectric phases. As described in …
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MEMS Transducer for Hearing Aid Device
<p>A study of implantable middle ear MEMS piezoelectric transducer for hearing aids was developed. The physical vibration deflection at the tip of the transducer is simulated using finite element method. Further, a study of thermoelastic damping effect of four designed MEMS mirrors used as …
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A simple force feedback accelerometer/seismometer based on a tuning fork displacement sensor
This thesis describes research into the use of a piezoelectric tuning fork as the displacement sensor in a simple force feedback seismometer. The research also includes the use of a second piezoelectric transducer as both the suspension system and the force transducer for the seismometer. A simple …
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Development of a vibration-powered impact recorder
… impact recorder (VPIR for short), uses a piezoelectric transducer to power a microcontroller, which uses the power to count the number of times a certain vibration threshold has been passed. The VPIR device operates in the following way: When the device is vibrated, the piezoelectric …
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Quadrature-point stabilization of Mach-Zehnder interferometers
… the application of one of them which uses a piezoelectric transducer in the reference arm of an all-fiber Mach-Zehnder interferometer.
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Ultrasound field measurement and modelling for non-destructive testing
… means of numeric methods. This thesis focuses on piezoelectric transducers and Electromagnetic Acoustical Transducer (EMAT). For testing with piezoelectric transducer (also called a probe), couplant has to be applied between the test material and the probe allowing for ultrasonic waves generated …
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Fiber optic methods for nondestructive testing
… analysis technique is used for calibrating the piezoelectric transducer cylinder (PZT) and JO/J2 spectrum analysis technique is used for demodulating the SAW signal from the interferometer. An extrinsic Fabry-Perot interferometric (EFPI) sensor is utilized for sensing acoustic emission, …
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Acoustic energy harvesting with emphasis on low frequencies
… objectives are set. The analysis considers the piezoelectric transducer to be the transduction element for this study. Initially, it provides a lumped element model (LEM) for evaluating the AEH potential of such transducers directly coupled to the sound field and utilizing such a framework, it …
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Application of acoustic emission sensing for the non-destructive evaluation of advanced composite materials
… resulted in the testing and analysis using the piezoelectric transducer only. Amplitude and frequency distribution analysis of the piezoelectrically detected signals from these specially designed composite samples was attempted. From the results, it was evident that a correlation could be made …
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Vibration Energy Harvesting IC Design with Incorporation of Two Maximum Power Point Tracking Methods
… energy harvesting IC harvests energy from a piezoelectric transducer (PZT) to provide power for a wireless sensor node (WSN). With a traditional rectification stage, a two-path three-switch dual-input dual-output architecture is adopted to extract power and regulate the output voltage for the …
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Design of an Analog Adaptive Piezoelectric Sensoriactuator
In order for a piezoelectric transducer to be used as a sensor and actuator simultaneously, a direct charge due to the applied voltage must be removed from the total response in order to allow observation of the mechanical response alone. Earlier researchers proposed electronic compensators to …
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Modelling techniques for 1-3 composite transducers
… the behaviour of a thickness mode composite piezoelectric transducer comprising an array of ceramic pillars embedded in a polymer matrix. Finite element analysis is employed to establish the vibrational and electromechanical characteristics of an arbitrary composite structure. Thereafter, the …
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Energy-efficient Interfaces for Vibration Energy Harvesting
… of vibration energy harvesting. In terms of the piezoelectric transducers, the open-circuit voltage is usually low, which limits its power while extracted by a full-bridge rectifier. In terms of the interface circuits, most reported circuits are limited by the power efficiency, suitability to …
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Neural Network Detection of Fatigue Crack Growth in Riveted Joints Using Acoustic Emission
… and riveted 7075-T6 specimens using a broadband piezoelectric transducer and a computer interfaced oscilloscope. The source of 1,311 signals was identified based on triggering logic, amplitude relationships, and time of arrival data collected from the broad-band transducer and three additional …
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Modeling wireless acoustic power transmission systems
… into account the properties of the acoustic transducers that create the acoustic signals, the propagation of the acoustic signals through the barrier, and the transducers and circuitry that transform the acoustic power back into electrical power. The thesis presents a model that translates …
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Piezoelectric Energy Harvesting for Powering Wireless Monitoring Systems
… optimization, prototype, and testing of novel piezoelectric energy harvesters for extracting energy from human walking, bio-inspired bi-stable motion, and torsional vibration as an alternative power supply for wireless monitoring systems. To provide a sustainable power supply for health care …
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