1280 results about "Shear waves" patented technology

A BAW resonator includes a piezoelectric layer, a first electrode, a second electrode, a substrate, and an acoustic reflector disposed between the substrate and the second electrode. The acoustic reflector has a plurality of layers. A performance of the acoustic reflector is determined by its reflectivity for a longitudinal wave existing in the BAW resonator at the resonance frequency of the BAW resonator and by its reflectivity for a shear wave existing in the BAW resonator at the resonance frequency of the BAW resonator. The layers of the acoustic reflector and layers disposed between the acoustic reflector and the piezoelectric layer are selected, with reference to their number, material, and thickness, such that the transmissivity for the longitudinal wave and the transmissivity for the shear wave in the area of the resonance frequency is smaller than −10 dB.

An imaging method for observing the propagation of a shear wave simultaneously at a multitude of points in a diffusing viscoelastic medium. The shear wave is caused to be generated by firing at least one focused ultrasound compression wave into the viscoelastic medium by means of an array of transducers, and then emitting at a fast rate and using the same array of transducers, unfocused ultrasound compression waves serving to obtain a succession of images of the medium, and processing the images obtained in this way in deferred time in order to determine the movements of the medium during the propagation of the shear wave.

An ultrasound system that is configured to determine whether adipose tissue of a patient received therapy at a treatment location. The system includes an ultrasound probe and a shear-wave-generating module to control the probe to provide a shear-wave beam that is configured to generate a shear wave at a first site within the patient. The shear wave is configured to propagate through the treatment location toward a second site within the patient. The system also includes a tracking module to control the probe to track the shear wave at the second site within the patient to determine if the treatment location received the therapy.

A bond log device comprising a sonde, an acoustic transducer, and an acoustic receiver. The acoustic transducer is comprised of a magnet combined with a coil, where the coil is energizable by an electrical current source. The acoustic transducer can also be comprised of an electromagnetic acoustic device. The acoustic transducer is capable of producing various waveforms, including compressional waves, shear waves, transversely polarized shear waves, Rayleigh waves, Lamb waves, and combinations thereof.

NDT inspection of an austenitic weld between two CRA Clad pipes using a phased ultrasonic transducer array system is described. The method may be performed during laying of gas/oil fatigue sensitive pipelines, for example, at sea. Two types of UT inspection may be generated simultaneously by a Phased Array on each side (Upstream and Downstream) of a girth weld. Firstly, mode converted longitudinal waves are used. These waves have properties that they propagate well. Shear waves are also used. The combination of these two ultrasonic waves, with the addition of surface waves, enables 100% of the girth weld to be inspected to the standard required in fatigue sensitive welds, such as Steel Catenary Risers. Shear waves and compression waves are emitted substantially contemporaneously. Defects may be detected and measured using time of flight information and amplitudes of radiation detected on reflection and on diffraction from the defect.

A low profile acoustic array (10) is configured to selectively respond to shear waves while rejecting compression wave energy in the frequency range of interest. One sensor array is configured as a linear strip with a frame segment having at least one longitudinally extending rail and a plurality of sensor elements (20) extending therefrom. These sensor elements have a resilient core and opposing PDVF outer layers configured with opposing polarities onto the core. The linear strip array also includes a pair of separate electrical signal transmission paths. The transmission lines can include a series of undulations formed thereon to help minimize undesired mechanical crossover between sensors. A carrier member can be configured to be detachably releasable carries the discrete sensors to maintain the positional alignment until they are secured to a patient.

A transcutaneous energy transfer system with subcutaneous non coupled coils is used to transmit power and signals to an implanted biological support device or sensor, such as a flow sensor for measuring relatively low flow rates, such as hydrocephalic shunt flow. The flow sensor is configured to convert a shear wave generated by a transducer to a longitudinal wave at the interface of a signal pathway and the flow, wherein the longitudinal wave travels parallel to the flow and exits a flow channel to convert to a shear wave which intersects a second transducer. The transcutaneous energy transfer employs a pair of inductive coupling coils, wherein the coils are disposed in zero coupling orientation which can include a perpendicular orientation of corresponding coil axes.

Fouling of heat exchange surfaces is mitigated by a process in which a mechanical force is applied to a fixed heat exchanger to excite a vibration in the heat exchange surface and produce shear waves in the fluid adjacent the heat exchange surface. The mechanical force is applied by a dynamic actuator coupled to a controller to produce vibration at a controlled frequency and amplitude output that minimizes adverse effects to the heat exchange structure. The dynamic actuator may be coupled to the heat exchanger in place and operated while the heat exchanger is on line.

Geophysical exploration for oil wells, the source from the vertical seismic profile aspect wave data stack depth domain Corridor profile approach is the use of in situ collection of well spacing VSP data, which will all receive points drilling depth of information and hierarchical data with the depth of information, the use of direct wave VSP data travel through and optimization algorithms are highly accurate anti-layer velocity model, the direct wave to the beginning of the reflected wave in the vicinity of the depth and precision homing imaging, further in-depth domain Corridor section and with the superposition of alternative conventional method leveled in the time domain, with corridors and the superposition method, the results can be superimposed for direct comparison with the drilling and seismic data stratified layer identification. More intuitive, but also made full use of VSP data in the depth of information, make geological formation of the earthquake response and drilling, logging data in depth domain direct contrast, a more intuitive geological layer and the relationship between seismic horizon, thereby enabling layer of identification and calibration more reliable.

The method and apparatus of the present invention provides for inducing and measuring shear waves within a wellbore casing to facilitate analysis of wellbore casing, cement and formation bonding. An acoustic transducer is provided that is magnetically coupled to the wellbore casing and is comprised of a magnet combined with a coil, where the coil is attached to an electrical current. The acoustic transducer is capable of producing and receiving various waveforms, including compressional waves, shear waves, Rayleigh waves, and Lamb waves as the tool traverses portions of the wellbore casing.

A method for inspecting welds between welded tubular ends includes arranging a series electromagnetic acoustic transducer (EMAT) assemblies in circumferential direction adjacent to an inner and/or outer surface of at least one of the welded tubular ends and inducing the EMAT assemblies to transmit sequentially or simultaneously acoustic shear wave signals towards the weld and to detect the shear waves reflected by and/or passing through the weld while the EMAT assemblies are maintained in a substantially fixed position relative to the weld such that at least a substantial part of the weld is scanned by the EMAT assemblies instantly after the weld is made.

An apparatus and method for determining fast and slow shear wave velocities and orientations in an anisotropic earth formation that reduces the error and ambiguity in calculating these parameters and eliminates the need for dipole receivers and multiple dipole sources. The apparatus generally includes a single dipole source capable of generating an acoustic signal within a borehole. The acoustic logging tool contains multiple levels of receivers. At each level, four receivers, which may be conventional pressure transducers, receive shear/flexural wave signals which propagate along the borehole earth formation. These receivers measure the pressure fields from the wave signals. A processing device, preferably a UNIX(TM) based computer, interpolates the measured pressure fields between any two adjacent receivers. The processing device performs cross-component decomposition on the pressure field to determine shear wave orientation and velocity. Using the shear wave orientation and velocity the processing device determines transit time anisotropy, energy anisotropy, and slowness anisotropy.

Methods and apparatus for ultrasonically scanning cylinders are provided. The methods and apparatus employ as few as one ultrasonic sensor for full immersion scanning and defect detection. Self-centering fixturing spins the cylinder, reducing vibration, allowing for fast ultrasonic scans. To create the 45 degree angle beam shear waves for the circumferential scans, the ultrasonic sensor is offset from the centerline of the cylinder, creating the correct angle for excitation of the shear wave.

Improved methods, systems, and apparatus for inspecting a structure using angle beam shear wave through-transmission ultrasonic signals involves positioning transducers at offset positions on opposing sides of the structure and permits inspection of the inside of the structure beneath surface defects and features. Magnetic coupling can be used for supporting a pair of leader-follower probes and defining offset positions between angle beam shear wave transducers carried by the probes. Inspection data can be collected for supporting real-time generation of three-dimensional image representations of the structure and of internal defects and features of the structure. Image generation and resolution using inspection data from angle beam shear wave ultrasonic signals can be supplemented using pulse-echo ultrasonic inspection data.

The invention relates to a reservoir shear wave velocity prediction method based on rock physics. The method comprises the steps that (1) supposing that the bulk modulus, the shear modulus and the density of a destination interval mineral are unknown constants, the error between a longitudinal wave velocity and a measured longitudinal wave velocity is acquired according to equation modeling, and the error between the acquired density and the measured density is calculated; (2) according to the minimum error criterion, the bulk modulus, the shear modulus and the density of a mineral component are inverted through a genetic algorithm; (3) and the shear wave velocity is calculated. According to the step (1), supposing that the elastic modulus of each rock component is an unknown constant in a reservoir logging curve section, the objective function of the inversion of the logging curve can be defined that a superscript M represents a simulation longitudinal wave velocity, O represents a logging observation longitudinal wave velocity, and w Rho and w rho represent normalized weighted coefficients; and the objective function is a nonlinear function of the bulk modulus, the shear modulus and the density of each mineral component. The method can be applied to a sand shale reservoir, and carbonate rock and other complex reservoirs.