Acoustic Wave
Mostrando 1-12 de 76 artigos, teses e dissertações.
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1. Optical Fiber Spool Acoustic Wave Resonances Employing a Mach-Zehnder Interferometer in Vacuum Chamber
Abstract The longitudinal, flexural, and torsional modes of acoustical resonances are presented for a long and small thickness cylindrical fiber spool. The fiber spool is built using a monomode optical fiber tightly wound in a helix form around a cylindrical Styropor. The acoustical resonance values are obtained using a Mach Zehnder interferometer with the f
J. Microw. Optoelectron. Electromagn. Appl.. Publicado em: 2020-12
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2. Mismatch Negativity Elicited by Verbal and Nonverbal Stimuli: Comparison with Potential N1
Abstract Introduction Mismatch negativity (MMN) is a long latency auditory evoked potential, represented by a negative wave, generated after the potential N1 and visualized in a resulting wave. Objective To identify the time of occurrence ofMMNafter N1, elicited with verbal and nonverbal stimuli. Methods Ninety individuals aged between 18 and 56 years
Int. Arch. Otorhinolaryngol.. Publicado em: 2020-06
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3. Pure-Tone Hearing Thresholds and Brainstem Auditory Evoked Potentials in Sporadic Ataxia
Abstract Introduction Spinocerebellar ataxia (SCA) is part of a genetic and clinical heteroge- neous group of neurodegenerative diseases characterized by progressive cerebellar ataxia. Objective To describe the results of audiological and electrophysiological hearing evaluations in patients with sporadic ataxia (SA). Methods A retrospective cross-secti
Int. Arch. Otorhinolaryngol.. Publicado em: 2020-03
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4. Laryngeal and Vocal Characterization of Asymptomatic Adults With Sulcus Vocalis
Abstract Introduction Sulcus vocalis is defined as a longitudinal depression on the vocal cord, parallel to its free border. Its most marked characteristic is breathlessness, caused by incomplete glottal closure, in addition to roughness, due to the decrease in mucosal wave amplitude of the vocal cords. Vocal acoustic aspects, such as fundamental voice fre
Int. Arch. Otorhinolaryngol.. Publicado em: 07/10/2019
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5. Simplified expressions for dynamic behavior of cylindrical shells uncoupled and coupled with liquids
Abstract The dynamic behavior of cylindrical shells is essential in many practical applications. These include in-vacuum and coupled vibrations of structures with contained fluids. Closed-form solutions are extremely complex since they involve many terms and algebraic operations that require numerical solvers. In this work, a simplified closed-form solution
Lat. Am. j. solids struct.. Publicado em: 22/07/2019
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6. Investigating Hyperbolic Shear Deformation Theory on vibroacoustic behavior of the infinite Functionally Graded thick plate
Abstract This paper applies acoustic analysis of Sound Transmission Loss (STL) through infinite Functionally Graded (FG) thick plate employing Hyperbolic Shear Deformation Theory (HSDT). The procedure for applying a FG plate is followed by considering the material properties are changed continually based on power-law distribution of the materials in terms of
Lat. Am. j. solids struct.. Publicado em: 04/02/2019
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7. Wave transmission across laminated composite plate in the subsonic flow Investigating Two-variable Refined Plate Theory
Abstract The main aim of this paper is to employ an extension of two-variable Refined Plate Theory (RPT2) to determine Sound Transmission Loss (STL) across laminated composite plate in contrast to external excitation. It should be noted that RPT2 known as a second type of Refined Plate Theory which includes the extension term in displacement field. To achie
Lat. Am. j. solids struct.. Publicado em: 14/06/2018
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8. Wave propagation in cellular locally resonant metamaterials
Abstract Locally resonant acoustic metamaterials have recently attracted a great interest due to their dynamic behaviour, characterized by a band gap at relatively low frequencies. This paper provides a numerical study, by means of finite element modal analyses, of the dynamic properties of 1D mass-in-mass and 2D cellular locally resonant metamaterials. The
Lat. Am. j. solids struct.. Publicado em: 04/06/2018
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9. Simultaneous prestack seismic inversion in a carbonate reservoir
Abstract We applied a method of Simultaneous Prestack Seismic Inversion (SPSI) in a hydrocarbon field located in the Campos Basin, Brazil. The goal was to study the application of this method to Albian carbonate rocks of the Quissamã Formation. Based on what is found in nearby fields, this Formation potentially contains hydrocarbon accumulations that can be
REM, Int. Eng. J.. Publicado em: 2018-03
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10. Ultrasonic method of microvibration detection: part II - additional processing method and applications
Abstract Introduction In the last 28 years, the scientific community has been using elastography to evaluate the mechanical properties of biological tissue. The aim of this work was the optimization of the UDmV method, presented in Part I of the series, by means of modifying the technique employed to generate the reference sine and cosine functions, used fo
Res. Biomed. Eng.. Publicado em: 17/08/2017
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11. Acoustic Birefringence and Poisson's Ratio Determined by Ultrasound: Tools to Follow-Up Deformation by Cold Rolling and Recrystallization
Poisson's ratio and birefringence, both measured by ultrasound, are used to follow the evolution of the anisotropy in ASTM A-36 steel plates cold-rolled between 5 and 50% deformation, and then subjected to recrystallization at 900 and 1000 ºC. Times of flight of longitudinal and shear waves along the thickness of the plates were measured. As orthotropy incr
Mat. Res.. Publicado em: 31/07/2017
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12. Ultrafast Dynamics of Au Nanopyramid Interfaces Prepared by Nanosphere Lithography: Effect of Substrate Chemical Composition
This work describes ultrafast spectroscopy studies of Au triangular pyramid particle arrays deposited over glass (termed Au/glass), and 190 nm indium tin oxide (ITO) film (termed Au/ITO/glass) prepared by nanosphere lithography. The linear absorption spectra of Au/glass and Au/ITO/glass exhibit surface plasmon resonances at 800 and 870 nm, respectively, in g
J. Braz. Chem. Soc.. Publicado em: 2016-02