Results 21 to 30 of about 3,530,342 (253)

Medidas de reflectância acústica na otosclerose: estudo de caso

Audiology: Communication Research, 2014
O objetivo deste trabalho foi analisar as medidas de reflectância em uma paciente com otosclerose. A paciente, do gênero feminino, 51 anos, apresentava queixa de hipoacusia bilateral e a hipótese diagnóstica de otosclerose.
Letícia Cortez Neto, Bruna Carla Cibin, Renata Mota Mamede Carvallo, Seisse Gabriela Gandolfi Sanches   +3 more
doaj   +1 more source

Reflection of an acoustic line source by an impedance surface with uniform flow

, 2014
An exact analytic solution is derived for the 2D acoustic pressure field generated by a time-harmonic line mass source located above an impedance surface with uniform grazing flow. Closed-form asymptotic solutions in the far-field are also provided.
Gabard, Gwénaël, Brambley, E.J., Gabard, G., Brambley, E. J.   +3 more
core   +1 more source

Effect of Plastic Fibers on Properties of Foamed Concrete [PDF]

Engineering and Technology Journal, 2013
The main objective of this work is to study the effect of adding plastic fibers on Lightweight Aggregate Foamed Concrete (LWAFC) using mix proportion of 1:2.6:0.4 by volume (cement: fine Porcelanite: coarse Porcelanite) with 2% foaming agent by weight of
Hisham K. Ahmed, Waleed A. Abbas, DohaM. Abdul-Razzaq   +2 more
doaj   +1 more source

Acoustic radiation from a pulsating spherical cap set on a spherical baffle near a hard/soft flat surface

, 2004
Radiation of sound from a spherical piston, set in the side of a rigid sphere, undergoing harmonic radial surface vibrations in an acoustic halfspace is analyzed in an exact fashion using the classical method of separation of variables.
Azarpeyvand, Mahdi, Hasheminejad, Seyyed M., Hasheminejad, S.M., Azarpeyvand, M.   +3 more
core   +1 more source

Real ear unaided gain and its relation with the equivalent volume of the external and middle ear

International Archives of Otorhinolaryngology, 2012
Introduction: Old age is associated with changes in the characteristics of the middle ear transmission system and in external ear resonance, and these carry implications for the hearing aid (HA) verification process for which targets and measures of the ...
Bastos, Bárbara Guimarães, Ferrari, Deborah Viviane, Blasc, Wanderléia Quinhoneiro   +2 more
doaj   +3 more sources

Topology-optimized chiral metamaterials for acoustic-mechanical co-optimization in waterborne mufflers achieving high load-bearing and noise reduction

Materials & Design
This work proposes a compact waterborne muffler that simultaneously achieves low-frequency broadband noise reduction and high load-bearing capacity by embedding topology-optimized chiral metamaterials into a square expansion chamber.
Chao Wang, Qi Jia, Yutong Qin, Zhoufu Zheng, Yang Wang, Runan Hua, Donghai Han, Dianlong Yu   +7 more
doaj   +1 more source

Acoustic transmission loss in Hilbert fractal metamaterials

Scientific Reports, 2023
Acoustic metamaterials are increasingly being considered as a viable technology for sound insulation. Fractal patterns constitute a potentially groundbreaking architecture for acoustic metamaterials.
Gianni Comandini, Morvan Ouisse, Valeska P. Ting, Fabrizio Scarpa   +3 more
doaj   +1 more source

Air‐Pressure–Actuated Vibroacoustic Metamaterial With Tunable Bandgap: Design, Modeling, and Characterization

Advanced Engineering Materials, EarlyView.
This article presents the design, modeling, and characterization of air‐pressure–actuated programmable vibroacoustic metamaterials (PVAMM). The study focuses on leveraging air pressure to dynamically tune resonance frequencies for effective noise attenuation.
William Kaal, Michael M. Becker, Sarah C. L. Fischer   +2 more
wiley   +1 more source

Research on Broadband Matching Method for Capacitive Micromachined Ultrasonic Transducers Based on PDMS/TiO₂ Particles

Micromachines, 2022
The study of impedance matching between a transducer and its working medium is an important part of acoustic transducer design. The traditional quarter wavelength matching (Q-matching) scheme is not suitable for broadband capacitive micromachined ...
Bizhen Gao, Sai Zhang, Changde He, Renxin Wang, Yuhua Yang, Licheng Jia, Zhihao Wang, Yang Wu, Shumin Hu, Wendong Zhang   +9 more
doaj   +1 more source

PSYNDEX Tests Review für TLE A1 - TESTS ZU LEARNING ENGLISH A 1

, 1984
This is a PSYNDEX Tests Review of TLE A1 - TESTS ZU LEARNING ENGLISH A 1. PSYNDEX Tests Reviews are written in German and describe and evaluate psychological and educational tests used in the German-speaking countries.
Prökel, Gerhard
core   +1 more source