Attenuation of Longitudinal Strain Wave in DAP Strip.

An inequality for longitudinal and transverse wave attenuation coefficients.

Total absorption, defined as the net flux of energy out of a bounded region averaged over one cycle for time harmonic motion, must be non-negative when there are no sources of energy within the region. This passivity condition places constraints on the non-dimensional absorption coefficients of longitudinal and transverse waves, γL and γT, in isotropic linearly viscoelastic materials. Typically...

Seismic Wave Attenuation in Carbonates

An Estimation of Wave Attenuation Factor in Ultrasonic Assisted Gravity Drainage Process

It has been proved that ultrasonic energy can considerably increase the amount of oil recovery in an immiscible displacement process. Although many studies have been performed on investigating the roles of ultrasonic waves, based on the best of our knowledge, little attention has been paid to evaluate wave attenuation parameter, which is an important parameter in the determination of the energy...

Bounds on the longitudinal and shear wave attenuation ratio of polycrystalline materials.

A lower bound to the longitudinal and shear attenuation ratio was recently derived for viscoelastic materials [Norris, J. Acoust. Soc. Am. 141, 475-479 (2017)]. This letter provides proof that a similar bound is present for low-frequency attenuation constants of polycrystals caused by grain scattering. An additional upper bound to the attenuation ratio is unveiled. Both bounds are proven to be ...

Longitudinal Strain

SEE PAGE 1351 F or decades, echocardiography has proved to be a well-established noninvasive imaging modality for bedside assessment of global left ventricular (LV) function in patients with heart failure (HF). The need for objective quantification of systolic LV pump function for prognostic purposes has led to the development of numerous echocardiographic indexes. LV ejection fraction (EF) is ...