Acoustic Parameters
Mostrando 13-24 de 141 artigos, teses e dissertações.
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13. Numerical Study of Vibro-Acoustic Responses of Un-Baffled Multi-Layered Composite Structure under Various End Conditions and Experimental Validation
Abstract This article presents the vibro-acoustic modeling and analysis of un-baffled laminated composite flat panels subjected to harmonic point load under various support conditions. The frequency values of the panel are obtained by using simulation model through the commercial finite element package (ANSYS) via batch input technique. Initially, the rate o
Lat. Am. j. solids struct.. Publicado em: 2017-08
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14. Realistic deformable 3D numeric phantom for transcutaneous ultrasound
Abstract Introduction Numerical phantoms are important tools to design, calibrate and evaluate several methods in various image-processing applications, such as echocardiography and mammography. We present a framework for creating ultrasound numerical deformable phantoms based on Finite Element Method (FEM), Linear Isomorphism and Field II. The proposed met
Res. Biomed. Eng.. Publicado em: 16/03/2017
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15. Pattern Identification on the Nonlinear Radial Motion of an Oscillating Spherical Bubble Using Neural Networks
Abstract The main goal of this article is to study the oscillatory motion of a spherical gas bubble immersed in a Newtonian liquid subjected to a harmonic pressure excitation. We use the classical Rayleigh-Plesset equation to study the radial motion of the bubble undergoing a forcing acoustic pressure field. The second order nonlinear ordinary differential e
Lat. Am. j. solids struct.. Publicado em: 2016-12
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16. Correlation between ultrasound velocity and densitometry in fresh and demineralized cortical bone
OBJECTIVE: To compare ultrasound propagation velocity with densitometry in the diaphyseal compact cortical bone of whole sheep metatarsals. METHODS: The transverse ultrasound velocity and bone mineral density of 5-cm-long diaphyseal bone segments were first measured. The bone segments were then divided into four groups of 15 segments each and demineralized
Clinics. Publicado em: 2016-11
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17. Acoustic communication in two species of the Hypsiboas albopunctatus group (Anura: Hylidae) in sympatry and allopatry
ABSTRACT Tropical anuran communities are very diverse. Nevertheless, much of their ecological and historical processes remain unknown. Bioacoustical studies are important to help to solve these puzzles. In the present study we examined the effect of environmental (air temperature and humidity) and morphological (body size) attributes on the acoustic paramete
Zoologia (Curitiba). Publicado em: 29/04/2016
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18. Ultrasound method applied to characterize healthy femoral diaphysis of Wistar rats in vivo
A simple experimental protocol applying a quantitative ultrasound (QUS) pulse-echo technique was used to measure the acoustic parameters of healthy femoral diaphyses of Wistar rats in vivo. Five quantitative parameters [apparent integrated backscatter (AIB), frequency slope of apparent backscatter (FSAB), time slope of apparent backscatter (TSAB), integrated
Braz J Med Biol Res. Publicado em: 04/04/2014
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19. Finite element simulation of laser generated ultrasound waves in aluminum plates
The Laser-Ultrasonic technique uses laser energy to generate ultrasound waves in various solids. This technique allows inspecting large structures. The generated ultrasound wave form is affected by features of laser pulse (wavelength, pulse duration, power density). The goal of this paper is to study the effects of laser parameters (rise time and beam radius
Lat. Am. j. solids struct.. Publicado em: 2014
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20. A study on acoustic behavior of poroelastic media bonded between laminated composite panels
A study on the acoustic behavior of double-walled panels, with sandwiched layer of porous materials is presented within Classical Laminated Plate Theory (CLPT) for laminated composite panels. For this purpose, equations of wave propagation are firstly extracted based on Biot's theory for porous materials, then the transmission loss (TL) of the structure is e
Lat. Am. j. solids struct.. Publicado em: 2014
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21. Sound transmission across orthotropic cylindrical shells using third-order shear deformation theory
The objective of this paper is representation of an analytical solution to calculate transmission loss (TL) of an arbitrarily thick cylindrically orthotropic shell, immersed in a fluid medium with a uniform external airflow and contains internal fluids. The shell is assumed to be infinitely long and is excited by an oblique plane wave. The displacements are
Lat. Am. j. solids struct.. Publicado em: 2014
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22. O papel da ultrassonografia na medida da gordura subcutânea e visceral e sua correlação com a esteatose hepática
Objective To evaluate the sonographic measurement of subcutaneous and visceral fat in correlation with the grade of hepatic steatosis. Materials and Methods In the period from October 2012 to January 2013, 365 patients were evaluated. The subcutaneous and visceral fat thicknesses were measured with a convex, 3–4 MHz transducer transversely placed 1 cm abo
Radiol Bras. Publicado em: 2013-10
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23. Vocal repertory of Scinax littoreus (Anura: Hylidae) with comments on the advertisement call of the Scinax perpusillus species group
The Scinax perpusillus species group consists of thirteen bromeligenous treefrogs, of which only six have had their acoustic parameters appropriately described. In this work, we present the vocal repertory of Scinax littoreus (Peixoto, 1988) based on recordings obtained from three different populations in the state of Rio de Janeiro, Brazil. Based on our obs
Zoologia (Curitiba). Publicado em: 2013-08
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24. Análise da influência de parâmetros acústicos na inteligibilidade da fala: um estudo em salas de aula de escolas municipais de João Pessoa.
Researchs in the area of environmental comfort conducted in schools reported that, considering the thermophysical variables, the acoustic variable is more important than the other variables, especially in relation to thermal, luminous and indoor air quality variables, since this is the variable that is directly tied to speech intelligibility, with impacts on
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 03/08/2012