Acoustic Vibration
Mostrando 1-12 de 28 artigos, teses e dissertações.
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1. Glottal Closure inWomen with No Voice Complaints or Laryngeal Disorders
Abstract Introduction The understanding of normal vocal production is essential to guide any voice professional as it is fundamental to understand the effects of the posterior glottal gap on the vocal quality. Objective The aim of the present study was to verify the association between glottic closure, acoustic parameters, and some characteristics of the
Int. Arch. Otorhinolaryngol.. Publicado em: 25/11/2019
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2. 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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3. Influence of water in the MQL technique in the grinding of steel AISI 4340 using CBN wheels
Abstract Usually, machining employs cooling methods to avoid high temperatures. In most cases, the cutting fluid is applied with high flow and low pressures. This technique consumes a large amount of cutting fluid that causes serious problems in the environment and in the health of the worker. An alternative to the conventional cooling method is the Minimum
REM, Int. Eng. J.. Publicado em: 2018-07
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4. 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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5. Noise Source Distribution of Coaxial Subsonic Jet-Short-Cowl Nozzle
ABSTRACT: The noise source distribution of a short-cowl coaxial jet operating at different velocity ratios is described in this work. This was motivated by an ongoing research about noise prediction of coaxial jets through Acoustic Analogy with purposes of industrial engine application. This research has been carried out between Universidade Federal de Uberl
J. Aerosp. Technol. Manag.. Publicado em: 2014-03
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6. 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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7. Avaliação dos efeitos de exercícios vocais em vozes normais com análise perceptivo-auditiva, acústica e de imagens laríngeas obtidas por videolaringoscopia de alta velocidade / Immediate effects of vocal exercise in normal voices using perceptual, acoustic analysis and of the high-speed videolaryngoscopy images
The aim is to detect the immediate effect of vocal exercises in normal voices. Thirty healthy subjects from 19 to 45 year old with no vocal complains participated in the study. The sustained vowels /a/ and /E/ were recorded in two moments: the first, we recorded the habitual voice, before any exercises; and the second, after from 1 to 5 minutes of continuous
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 20/01/2012
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8. Estudo do ruído de rodagem estrutural através da análise dos caminhos de transferência de energia - TPA / Structure-borne road noise study using transfer path analysis, TPA
The road noise, vibration and harshness (Road NVH) present from 20 Hz to 1000 Hz approximately, begins from the tires vibration and acoustic propagation and their interactions with the road surfaces. In these noise sources, both structural-borne and air-borne noise contributions are relevant to vehicle refinement. The constant efforts to study the vehicle as
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 31/05/2011
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9. MONITORING FLEXIBLE RISERS WITH OPTICAL FIBER SENSORS / MONITORAMENTO DE RISERS FLEXÍVEIS COM SENSORES A FIBRA ÓPTICA
The interest in structural health monitoring of flexible risers has grown significantly in recent years. For ducts that are already reaching their design life, monitoring systems can provide early warnings of potential failures and also assist the operator in scheduling downtime. Different techniques are being tested by operators of flexible pipes such as au
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 07/04/2011
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10. Control strategies applied for reducing the vibration and torque ripple of a special Switched Reluctance Motor
Despite its robustness the Switched Reluctance Motors (SRMs) present some inconvenient drawbacks as a major torque ripple, vibration and acoustic noise when compared to other types of motors. These characteristics are usually related to factors such as the salient poles in the stator and in the rotor, the switched feeding and the control strategy imposed by
Journal of Microwaves, Optoelectronics and Electromagnetic Applications. Publicado em: 2011-06
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11. Aeroacoustics of dual-stream jets with application to turbofan engines.
A Computational Aeroacoustics (CAA) and a novel semi-empirical model is developed for predicting the noise generated by the jet flow through dual stream (coaxial) nozzles, as found in modern turbofan engines. The acoustic source model was developed in a 2D and 3D framework, based on the Lilley s Equations, following the traditional MGBK method from NASA Lang
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 26/06/2009
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12. Analysis of 1-3 piezocomposite and homogeneous piezoelectric rings for power ultrasonic transducers
Some power ultrasonic transducers, such as Tonpilz transducers, require high-power transmitting capability as well as broadband performance. Optimized vibrational modes can achieve these requirements. This work compares the resonant characteristics and the surface vibration modes between a homogeneous piezoelectric ring and a 1-3 piezocomposite ring, both us
Journal of the Brazilian Society of Mechanical Sciences and Engineering. Publicado em: 2009-12