Global dynamics and topology of two-phase mixing layer flow through simultaneous gas and liquid velocity measurements

This study reports the first time-resolved particle image velocimetry characterization of a planar two-phase mixing layer flow, whose velocity field is measured simultaneously in gas and liquid streams. Two parallel air and water flows meet downstream of a splitter plate, giving rise to an initially spanwise invariant configuration. The aim...

High-resolution P- and S-wave reflection studies of an intraplate structure: The Azambuja fault, Portugal

The Azambuja fault is a NNE trending structure located 50 km north of Lisbon, the capital and most populous city of Portugal. The fault has been considered as a possible source for the historical, large earthquakes. Understanding this fault is a priority in seismic hazard evaluation of this region. The fault has a clear morphological...

An ultrasonic shear wave viscometer for low viscosity Newtonian liquids

A method based on ultrasonic wave propagation is applied for the determination of the viscosity of low viscous liquids. A waveguide is used to remotely transmit the ultrasonic waves from a shear piezoelectric transducer into the liquid. At the solid-liquid interface, a guided wave mode, the shear mode, is used to extract the liquid viscosity....

Reproducibility of Natural Shear Wave Elastography Measurements

For the quantification of myocardial function, myocardial stiffness can potentially be measured non-invasively using shear wave elastography. Clinical diagnosis requires high precision. In 10 healthy volunteers, we studied the reproducibility of the measurement of propagation speeds of shear waves induced by aortic and mitral valve closure ...

Cardiac Shear Wave Elastography Using a Clinical Ultrasound System

The propagation velocity of shear waves relates to tissue stiffness. We prove that a regular clinical cardiac ultrasound system can determine shear wave velocity with a conventional unmodified tissue Doppler imaging (TDI) application. The investigation was performed on five tissue phantoms with different stiffness using a research platform...

Cardiac Shear Wave Velocity Detection in the Porcine Heart

Cardiac muscle stiffness can potentially be estimated non-invasively with shear wave elastography. Shear waves are present on the septal wall after mitral and aortic valve closure, thus providing an opportunity to assess stiffness in early systole and early diastole. We report on the shear wave recordings of 22 minipigs with high-frame-rate...

An integrated shear-wave velocity model for the Groningen gas field, The Netherlands

A regional shear-wave velocity (V_S) model has been developed for the Groningen gas field in the Netherlands as the basis for seismic microzonation of an area of more than 1000 km². The V_S model, extending to a depth of almost 1 km, is an essential input to the modelling of hazard and risk due to induced...

Earthquake-faulting-related deformation in soil evidenced in S-wave shallow reflection data: Field results from Portugal

Expressions of ductile, soft-sediment deformations induced by ground movements due to past earthquakes are difficult to recognize in near-surface soils. We have carried out shallow S-wave reflection studies in a seismically active area located northeast of metropolitan Lisbon, Portugal. Identifying shallow disturbed zones and hidden fault...

Characterization of a heterogeneous landfill using seismic and electrical resistivity data

Understanding the processes occurring inside a landfill is important for improving the treatment of landfills. Irrigation and recirculation of leachate are widely used in landfill treatments. Increasing the efficiency of such treatments requires a detailed understanding of the flow inside the landfill. The flow depends largely on the...

Shear wave seismic interferometry for lithospheric imaging: Application to southern Mexico

Seismic interferometry allows for the creation of new seismic traces by cross correlating existing ones. With sufficient sampling of remote-source positions, it is possible to create a virtual source record by transforming a receiver location into a virtual source. The imaging technique developed here directly retrieves reflectivity information...

Imaging scatterers in landfills using seismic interferometry

A significant problem with landfills is their aftercare period. A landfill is considered to be safe for the environment only after a relatively long period of time. Until it reaches such a condition, it has to be periodically treated. Not only are treatments very expensive, but they could be dangerous as well; for example, when barriers limiting...

Nongeometrically converted shear waves in marine streamer data

Under certain circumstances, marine streamer data contain nongeometrical shear body wave arrivals that can be used for imaging. These shear waves are generated via an evanescent compressional wave in the water and convert to propagating shear waves at the water bottom. They are called “nongeometrical” because the evanescent part in the water...