Two-dimensional discrete granular phononic crystal for shear wave control

2012 ◽  
Vol 86 (13) ◽  
Author(s):  
H. Pichard ◽  
A. Duclos ◽  
J-P. Groby ◽  
V. Tournat ◽  
V. E. Gusev
2016 ◽  
Vol 25 (4) ◽  
pp. 525-532 ◽  
Author(s):  
Monica Lupșor-Platon ◽  
Radu Badea ◽  
Mirela Gersak ◽  
Anca Maniu ◽  
Ioana Rusu ◽  
...  

There has been great interest in the development of non-invasive techniques for the diagnosis of liver fibrosis in chronic liver diseases, including ultrasound elastographic methods. Some of these methods have already been adequately studied for the non-invasive assessment of diffuse liver diseases. Others, however, such as two-dimensional Shear Wave Elastography (SWE), of more recent appearance, have yet to be validated and some aspects are for the moment incompletely elucidated. This review discusses some of the aspects related to two-dimensional SWE: the examination technique, the examination performance indicators, intra and interobserver agreement and clinical applications. Recommendations for a high-quality examination technique are formulated. Key words:  –  –  – Two-dimensional Shear Wave Elastography. Abbreviations: 2D- SWE: Two-dimensional Shear Wave Elastography; 3D- SWE: Three-dimensional Shear Wave Elastography; AUROC: area under the receiver operating characteristic curves; ARFI Acoustic Radiation Force Impulse Elastography; EFSUMB: European Federation of Societies for Ultrasound in Medicine and Biology; HVPG: hepatic venous pressure gradient; LS: liver stiffness; LR: likelihood ratio; NPV: negative predictive value; PPV: positive predictive value; ROI: region of interest; RT-E: Real Time-Elastography; Se: sensitivity; Sp: specificity; TE: Transient Elastography; US: ultrasound; VM: valid measurement; E: Young’s modulus


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Hai-Fei Zhu ◽  
Xiao-Wei Sun ◽  
Ting Song ◽  
Xiao-Dong Wen ◽  
Xi-Xuan Liu ◽  
...  

AbstractIn view of the influence of variability of low-frequency noise frequency on noise prevention in real life, we present a novel two-dimensional tunable phononic crystal plate which is consisted of lead columns deposited in a silicone rubber plate with periodic holes and calculate its bandgap characteristics by finite element method. The low-frequency bandgap mechanism of the designed model is discussed simultaneously. Accordingly, the influence of geometric parameters of the phononic crystal plate on the bandgap characteristics is analyzed and the bandgap adjustability under prestretch strain is further studied. Results show that the new designed phononic crystal plate has lower bandgap starting frequency and wider bandwidth than the traditional single-sided structure, which is due to the coupling between the resonance mode of the scatterer and the long traveling wave in the matrix with the introduction of periodic holes. Applying prestretch strain to the matrix can realize active realtime control of low-frequency bandgap under slight deformation and broaden the low-frequency bandgap, which can be explained as the multiple bands tend to be flattened due to the localization degree of unit cell vibration increases with the rise of prestrain. The presented structure improves the realtime adjustability of sound isolation and vibration reduction frequency for phononic crystal in complex acoustic vibration environments.


2021 ◽  
Vol 118 (22) ◽  
pp. 224104
Author(s):  
Yihao Song ◽  
Yanfeng Shen

2006 ◽  
Vol 88 (26) ◽  
pp. 263505 ◽  
Author(s):  
Manzhu Ke ◽  
Zhengyou Liu ◽  
Pei Pang ◽  
Wengang Wang ◽  
Zhigang Cheng ◽  
...  

2005 ◽  
Vol 72 (1) ◽  
Author(s):  
Honggang Zhao ◽  
Yaozong Liu ◽  
Gang Wang ◽  
Jihong Wen ◽  
Dianlong Yu ◽  
...  

2018 ◽  
Vol 49 (1) ◽  
pp. 91-98 ◽  
Author(s):  
Paraskevi Galina ◽  
Efthymia Alexopoulou ◽  
Aglaia Zellos ◽  
Virginia Grigoraki ◽  
Tania Siahanidou ◽  
...  

Sign in / Sign up

Export Citation Format

Share Document