Results 21 to 30 of about 22,518 (261)

Acoustic behavior of composites with gradient impedance

Materials & Design, 2020
Conventional acoustic materials with uniform media which are of fixed impedance and density are unable to satisfy the requirements of the development of modern acoustic technology in volume, weight, pressure resistance and stealth performance.
Yiwen Feng, Jing Qiao, Longqiu Li
doaj   +1 more source

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

Acoustics, 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, Aleksandr Kuznetsov, Igor Khramtsov, Oleg Kustov   +3 more
doaj   +1 more source

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

Nihon 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, Daisuke SHIRAGA, Shunsuke NAKAMURA, Shotaro YAMAZAKI, Tonau NAKAI, Masaharu NISHIMURA, Yuki MITSUI, Shinji AKAMATSU   +7 more
doaj   +1 more source

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

Applied 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
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Measurement of Acoustic Impedance [PDF]

The Journal of the Acoustical Society of America, 1939
Apparatus developed for determining acoustic impedance will be described and demonstrated. The device is the acoustical equivalent of an electrical transmission line.
R. D. Fay, W. M. Hall
openaire   +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

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, Liu Xiaoyan, Gu Jianying, Guo Jiacheng, Liu Zhongyuan, Fu Huiying   +5 more
doaj   +1 more source

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

European 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, Kazufumi Kobayashi, Soichiro Kiyono, Tetsuhiro Chiba, Naoya Kato, Masayuki Ohtsuka, Kazuyo Ito, Tadashi Yamaguchi, Shuichiro Shiina   +8 more
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ANALISIS SIFAT FISIS PADA RESERVOAR BATUPASIR MENGGUNAKAN METODE SEISMIK INVERSI IMPEDANSI AKUSTIK (AI) DAN MULTIATRIBUT PADA LAPANGAN “MNF” CEKUNGAN BONAPARTE

JGE, 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, Bagus Sapto Mulyatno, Egie Wijaksono   +2 more
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Integrating seismic acoustic impedance inversion and attributes for reservoir analysis over ‘DJ’ Field, Niger Delta

Journal of Petroleum Exploration and Production Technology, 2019
Structural interpretation and inversion analysis were used to characterize hard-to-image reservoirs, to predict subsurface interwell reservoir properties for optimum reservoir heterogeneity description, and to fine-tune drilling locations in ‘DJ’ Field ...
Ayodeji Alabi, Pius Adekunle Enikanselu
doaj   +1 more source

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

Brazilian 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, Livia de Moura Spagnuolo Gomes, Danilo Jotta Ariza Ferreira, Rodrigo Bijani, Antonio Fernando Menezes Freire   +4 more
doaj   +1 more source