Results 21 to 30 of about 1,265,505 (345)

Comparison of Semi-Empirical Impedance Models for Locally-Reacting Acoustic Liners in a Wide Range of Sound Pressure Levels

open access: yesAcoustics, 2023
A comparison is considered of the experimentally obtained impedance of locally reacting acoustic liner samples with the impedance calculated using semi-empirical Goodrich, Sobolev and Eversman models. The semi-empirical impedance models are outlined.
Vadim Palchikovskiy   +3 more
doaj   +1 more source

Acoustic Vector-Corrected Impedance Meter [PDF]

open access: yes, 2014
We describe the development of a novel instrument intended for the measurement of the acoustical reflection coefficient of materials. The instrument effectively implements a one-port vector-corrected network analyzer in the acoustic, rather than the ...
Pennington, Kyle, Scott, Jonathan B.
core   +2 more sources

A conventional method for acoustic impedance eduction in a flow duct based on the straight forward method

open access: yesNihon Kikai Gakkai ronbunshu, 2019
A conventional method for acoustic impedance eduction in a flow duct is proposed. This method is based on the straight forward method. Assuming that a single mode propagates in the duct and the flow is uniform, propagation constants for both forward and ...
Tomonobu GOTO   +7 more
doaj   +1 more source

Panel of resonators with variable resonance frequency for noise control [PDF]

open access: yes, 2012
The article focuses on acoustic resonators made of perforated sheets bonded onto honeycomb cavities. This kind of resonators can be used in adverse conditions such as high temperature, dirt and mechanical constraints. For all these reasons, they are, for
Cherrier, Olivier   +2 more
core   +3 more sources

Prediction of the Absorption Characteristics of Non-Uniform Acoustic Absorbers with Grazing Flow

open access: yesApplied Sciences, 2023
In this paper, planar and the cylindrical broadband non-uniform acoustic absorbers were constructed, both of which use broadband absorption units (BAUs) as their building blocks.
Yang Ou, Yonghui Zhao
doaj   +1 more source

Identification of roof and floor lithology of coal measures strata based on double modes inversion method: a case of No.3 coal seam in Sihe mining area

open access: yes矿业科学学报, 2018
In order to improve the classification accuracy of No.3 coal seam roof and floor lithology in Sihe mine, the research of wave impedance and gamma ray pseudo acoustic impedance inversion method of dual mode identifications of coal bearing strata lithology
Li Yuying   +5 more
doaj   +1 more source

Free fatty acid-based low-impedance liver image: a characteristic appearance in nonalcoholic steatohepatitis (NASH)

open access: yesEuropean Radiology Experimental, 2020
Background To examine in vitro acoustic property of nonalcoholic fatty disease in mouse and human liver to identify nonalcoholic steatohepatitis (NASH). Methods The acoustic impedance (× 106 kg/m2/s) was measured in 35 free fatty acids (FFAs, 500 mmol/L)
Hitoshi Maruyama   +8 more
doaj   +1 more source

ANALISIS SIFAT FISIS PADA RESERVOAR BATUPASIR MENGGUNAKAN METODE SEISMIK INVERSI IMPEDANSI AKUSTIK (AI) DAN MULTIATRIBUT PADA LAPANGAN “MNF” CEKUNGAN BONAPARTE

open access: yesJGE, 2020
Analysis of the physical properties of the sandstone reservoir in this study was carried out using the acoustic impedance inversion method and seismic multi-attribute which was carried out at the Bonaparte Basin "MNF" Field.
Muhammad Niko Febridon   +2 more
doaj   +1 more source

Acoustic Energy Harvesting of Piezoelectric Ceramic Composites

open access: yesEnergies, 2022
Acoustic energy is an often overlooked but increasingly prevalent source of ambient energy that could be scavenged to power a wide range of devices. Piezoelectric materials are often used, but the tradeoff between acoustic impedance matching and the ...
Jose Figueroa, Margo Staruch
doaj   +1 more source

An integrated approach for carbonate reservoir characterization: a case study from the Linguado Field, Campos Basin

open access: yesBrazilian Journal of Geology, 2020
The main reservoirs in the Linguado Field are grainstone and packstone carbonates composed of oolites, oncolites, pelloids, and rare bioclasts, of the Quissamã Formation (Albian-age) and coquinas of the Coqueiros Formation (Aptian-age).
Wagner Moreira Lupinacci   +4 more
doaj   +1 more source

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