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You searched for +publisher:"Penn State University" +contributor:("Robert M. Keolian, Committee Member"). Showing records 1 – 2 of 2 total matches.

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Penn State University

1. Karun, Ronald James. DESIGN AND TESTING OF A SINGLE-CRYSTAL, LOW-FREQUENCY, DUAL-RESONANT SHEAR-MODE TRANSDUCER FOR SONAR APPLICATIONS.

Degree: 2018, Penn State University

Recent crystallographic engineering has uncovered enhanced piezoelectric properties that are resident in “relaxor” ferroelectric crystals. With the proper crystallographic cut, the ternary relaxor single crystal, Pb(In1/2Nb1/2)O3-Pb(Mg1/3Nb2/3)O3-PbTiO3, or PIN-PMN-PT, exhibits piezoelectric strain and compliance coefficients that are approximately four times greater than conventional piezoelectric ceramics. The longitudinal and shear piezoelectric properties and responses in these crystals are then modified through a process called coordinate rotation. Coordinate rotation takes advantage of domain orientations that form within the material during crystal growth. A PIN-PMN-PT crystal with a zxt±45̊ cut takes advantage of this process and produces a d36 shear mode of operation. This cut produces a d36 piezoelectric strain coefficient of –236.8 x 10-11 m/V, which outperforms conventional piezoelectric ceramics that routinely exhibit piezoelectric strain coefficients near 59.3 x 10-11 m/V. Additionally, the PIN-PMN-PT zxt±45̊ crystal cut results in a SE66 compliance coefficient of 17.970 x 10-11 m2/N as compared to the conventional piezoelectric ceramic PZT-5 with a SE66 compliance coefficient of 4.256 x 10-11 m2/N. The increased compliance coefficient leads to a softer material with a higher coupling factor. The higher coefficients and coupling factors allow for a more efficient transfer of energy between the electrical and mechanical domains. Eight PIN-PMN-PT single crystals (four with a zxt+45̊ crystal cut and four with a zxt-45̊ crystal cut) were recently integrated into a SONAR transducer design that combines low frequency operation with small packaging and high acoustic output. Contrary to more common shear coefficients, the d36 mode of vibration operates with working electrodes that are the same as the poling electrodes. The major advantage of using the PIN-PMN-PT single crystals in the d36 shear mode of operation is that the applied electric field is in the poling direction, which allows for a much higher AC drive field and results in a significantly higher mechanical quality factor. These parameters lend themselves well to compact, low frequency, high power devices and are not available in conventional piezoelectric ceramics. This study explores this new mode of operation using a tonpilz transducer design and focuses on the ability to design multiple resonances into the structure to tailor the performance of the device. The separation in frequency between multiple resonances can be increased or decreased to tailor the transducer for specific functions. The resonances can be modified to lower the frequency of operation or improve the acoustic output. When separated, the resonances serve to extend the operating bandwidth of the device. The primary technical objective is to incorporate single crystal relaxor-ferroelectrics into a broadband, compact, high power, low frequency transducer. The tonpilz shear mode transducer using d36 crystals is a projector that meets these qualifications. During… Advisors/Committee Members: Robert M. Keolian, Dissertation Advisor/Co-Advisor, Thomas B. Gabrielson, Committee Chair/Co-Chair, Stephen C. Thompson, Committee Member, Robert M. Keolian, Committee Member, Jose Palacios, Outside Member.

Subjects/Keywords: tonpilz transducer; PIN-PMN-PT; d36 shear mode transducer; zxt±45̊ crystal cut; ternary relaxor single crystal

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Karun, R. J. (2018). DESIGN AND TESTING OF A SINGLE-CRYSTAL, LOW-FREQUENCY, DUAL-RESONANT SHEAR-MODE TRANSDUCER FOR SONAR APPLICATIONS. (Thesis). Penn State University. Retrieved from https://submit-etda.libraries.psu.edu/catalog/15904rjk5257

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16th Edition):

Karun, Ronald James. “DESIGN AND TESTING OF A SINGLE-CRYSTAL, LOW-FREQUENCY, DUAL-RESONANT SHEAR-MODE TRANSDUCER FOR SONAR APPLICATIONS.” 2018. Thesis, Penn State University. Accessed October 29, 2020. https://submit-etda.libraries.psu.edu/catalog/15904rjk5257.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7th Edition):

Karun, Ronald James. “DESIGN AND TESTING OF A SINGLE-CRYSTAL, LOW-FREQUENCY, DUAL-RESONANT SHEAR-MODE TRANSDUCER FOR SONAR APPLICATIONS.” 2018. Web. 29 Oct 2020.

Vancouver:

Karun RJ. DESIGN AND TESTING OF A SINGLE-CRYSTAL, LOW-FREQUENCY, DUAL-RESONANT SHEAR-MODE TRANSDUCER FOR SONAR APPLICATIONS. [Internet] [Thesis]. Penn State University; 2018. [cited 2020 Oct 29]. Available from: https://submit-etda.libraries.psu.edu/catalog/15904rjk5257.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Karun RJ. DESIGN AND TESTING OF A SINGLE-CRYSTAL, LOW-FREQUENCY, DUAL-RESONANT SHEAR-MODE TRANSDUCER FOR SONAR APPLICATIONS. [Thesis]. Penn State University; 2018. Available from: https://submit-etda.libraries.psu.edu/catalog/15904rjk5257

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation


Penn State University

2. Swaminathan, Anand. Experimental Investigation of Dynamic Stabilization of the Rayleigh-Bénard Instability by Acceleration Modulation.

Degree: 2017, Penn State University

This dissertation presents the results of an experimental investigation of the parametric stabilization of Rayleigh-Bénard convection through the imposition of vibration. It has been theorized for many years that vibration could be employed to suppress natural convection, in an analogous manner to the Kapitza pendulum. The ability to dynamically stabilize Rayleigh-Bénard convection using acceleration modulation is of interest to groups who design and study thermoacoustic machines, as the introduction of parasitic convection can have deleterious effects on the desired operation and efficiency of the device. These performance issues caused by suspected convective instability have been seen both in traveling wave thermoacoustic refrigerators and in cryogenic pulse tube chillers. This dissertation reports the results of an experiment intended to determine the vibratory, fluidic, and geometric conditions under which a small, rectangular container of statically unstable fluid may be stabilized by vertical vibration, incorporating the computational methods of R. M. Carbo [J. Acoust. Soc. Am. 135(2), 654–668 (2014)]. Measurements are obtained using a large-displacement kinematic shaker of an original design with the convecting gas characterized using both thermal transport measurements and flow visualization employing tracer particles illuminated by a diode laser light sheet phase-locked to the shaker. These experiments are believed to be the first demonstrating the suppression of convection through vibration in rectangular containers of macroscopic scale. Advisors/Committee Members: Steven L. Garrett, Dissertation Advisor/Co-Advisor, Steven L. Garrett, Committee Chair/Co-Chair, Robert M. Keolian, Committee Member, Victor Ward Sparrow, Committee Member, Diane Marie Henderson, Outside Member, Robert William Smith, Special Member.

Subjects/Keywords: Thermoacoustics; Acoustics; Rayleigh-Bénard convection; Pulse tube cryocooler; Parametric stabilization

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Swaminathan, A. (2017). Experimental Investigation of Dynamic Stabilization of the Rayleigh-Bénard Instability by Acceleration Modulation. (Thesis). Penn State University. Retrieved from https://submit-etda.libraries.psu.edu/catalog/14553azs5363

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16th Edition):

Swaminathan, Anand. “Experimental Investigation of Dynamic Stabilization of the Rayleigh-Bénard Instability by Acceleration Modulation.” 2017. Thesis, Penn State University. Accessed October 29, 2020. https://submit-etda.libraries.psu.edu/catalog/14553azs5363.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7th Edition):

Swaminathan, Anand. “Experimental Investigation of Dynamic Stabilization of the Rayleigh-Bénard Instability by Acceleration Modulation.” 2017. Web. 29 Oct 2020.

Vancouver:

Swaminathan A. Experimental Investigation of Dynamic Stabilization of the Rayleigh-Bénard Instability by Acceleration Modulation. [Internet] [Thesis]. Penn State University; 2017. [cited 2020 Oct 29]. Available from: https://submit-etda.libraries.psu.edu/catalog/14553azs5363.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Swaminathan A. Experimental Investigation of Dynamic Stabilization of the Rayleigh-Bénard Instability by Acceleration Modulation. [Thesis]. Penn State University; 2017. Available from: https://submit-etda.libraries.psu.edu/catalog/14553azs5363

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

.