Now showing items 21-30 of 179
Characterization of multiple piezoelectric actuators for structural excitation
(Acoustical Society of America, 1991-07-01)
The thrust of the present work is to analytically and experimentally study the response of a simply supported beam driven by multiple piezoelectric actuators in an effort to understand distributed excitation of the structure. ...
Active control of noise transmission through rectangular plates using multiple piezoelectric or point force actuators
(Acoustical Society of America, 1991-11-01)
This paper analytically demonstrates the use of multiple piezoelectric actuators bonded to the surface and point force actuators applied directly to a plate to reduce sound transmission through the plate. A harmonic plane ...
Infrared activity in the Aurivillius layered ferroelectric SrBi2Ta2O9
(American Physical Society, 1998-03-01)
Experimental studies were carried out on infrared-active phonons in the Aurivillius ferroelectric SrBi2Ta2O9 (SBT), using reflectivity measurements (down to 200 cm(-1)) and transmission measurements (down to 100 cm(-1)) ...
Incoherent Bandpass Spatial-Filtering with Longitudinal Periodicity
(Optical Society of America, 1990-09-01)
We explore the possibility of realizing bandpass filtering with longitudinal periodicity in incoherent systems. The necessary condition for spatial filtering to be longitudinally periodic is derived. Results indicate that ...
Thickness dependence of second-harmonic generation in thin films fabricated from ionically self-assembled monolayers
(AIP Publishing, 1999-01-01)
An ionically self-assembled monolayer (ISAM) technique for thin-film deposition has been employed to fabricate materials possessing the noncentrosymmetry that is requisite for a second-order, chi((2)), nonlinear optical ...
First-principles study of several hypothetical silica framework structures
(American Physical Society, 1995-09-15)
Several hypothetical silica structures have been generated using a simulated-annealing strategy with an ab initio based covalent-bonding potential. First-principles total-energy pseudopotential methods have been used to ...
Development of a new standard laboratory protocol for estimating the field attenuation of hearing protection devices. Part III. the validity of using subject-fit data
(Acoustical Society of America, 1998-02-01)
The mandate of ASA Working Group S12/WG11 has been to develop "laboratory and/or field procedure(s) that yield useful estimates of field performance" of hearing protection devices (HPDs). A real-ear attenuation at threshold ...
Investigation of Subcombination Internal Resonances in Cantilever Beams
Activation of subcombination internal resonances in transversely excited cantilever beams is investigated. The effect of geometric and inertia nonlinearities, which are cubic in the governing equation of motion, is considered. ...
Arrival times for dissipative, nonlinear second-sound waves in solids
(American Physical Society, 1995-07-01)
We extend our original analysis begun in Tarkenton et al. [Phys. Rev. B 49, 11 794 (1994)] to include dissipative effects that are important in real cryogenic systems where nonlinear second sound exists. We present results ...
Dynamic Response of Cantilevered Thin-Walled Beams to Blast and Sonic-Boom Loadings