A tissue sample that has been removed from a subject can be evaluated. A change in speed of the energy traveling through the sample is evaluated to monitor changes in the biological sample during processing. The monitoring can detect movement of fluid with the sample and cross-linking. A system for performing the method can include a transmitter that outputs the energy and a receiver configured to detect the transmitted energy.

A method comprising the steps of: (a) forming one or more friction materials of a brake pad; and (b) inspecting each of the one or more friction materials with one or more ultrasonic testers while each of the one or more friction materials are within a manufacturing line to determine if each of the one or more friction materials meet one or more desired material properties.

A system for and a method of measuring ultrasonic wave velocities in a subterranean core specimen is provided. Ultrasonic wave velocities are measured from the side surfaces (faces) of a polygonal-shaped core specimen having at least ten sides or faces. Stress is introduced to the core specimen by hydraulic rams associated with each set of opposing sides. As stress is applied, ultrasonic waves are introduced to at least one side of the set of opposing sides and the wave transmitted through the core specimen is measured. Subsequently, the wave velocity for the ultrasonic wave can be calculated based on the measurements taken. Also, elastic properties associated with the core specimen can be calculated.

Systems, devices, and methods for evaluating a volume of interest of an earth formation. Methods include estimating a parameter of interest of a volume of the formation using a value of a signal property (frequency amplitude) for a second harmonic mode signal component of a detected acoustic signal from the volume. Methods may include activating a transmitter to propagate an acoustic wave through the volume; producing the detected acoustic signal at a receiver responsive to the acoustic wave; and identifying the fundamental mode signal and the second harmonic mode signal associated with the detected acoustic signal. Methods include estimating an acoustic wave non-linearity parameter () for the volume using a relationship between the value of the signal property of the second harmonic mode signal component and a value of the signal property for a fundamental mode signal component of the detected acoustic signal.

Methods and apparatus for obtaining data from a density-viscosity (DV) sensor of a downhole tool, wherein the DV sensor comprises a resonating element disposed in a fluid flowing in a flowline of the downhole tool, and determining a resonance frequency and quality factor of the resonating element utilizing a nonlinear regression and/or a plurality of resonance modes exhibited by the obtained data.

A tissue sample that has been removed from a subject can be evaluated. A change in speed of the energy traveling through the sample is evaluated to monitor changes in the biological sample during processing. The monitoring can detect movement of fluid with the sample and cross-linking. A system for performing the method can include a transmitter that outputs the energy and a receiver configured to detect the transmitted energy.

Systems and methods for implementation of the heterodyne effect in structural health monitoring (SHM) systems are provided. A system or method can include propagating a first signal with a first frequency and a second signal with a second frequency through a subject structure, and analyzing the output response to determine if a third frequency has been created, according to the heterodyne effect.

Method for measuring a physical parameter in soft tissues of a mammal, in which a mechanical shear wave is propagated through the soft tissues and observation of the propagation leads to determine values of a shear wave propagation parameter. The physical parameter is computed on the basis of these values.

The invention relates to a method or operating mode which, using a device for emitting and receiving sonic and/or ultrasonic torsional waves, can be used to obtain data relating to the consistency or elasticity of quasi-incompressible solid media, preferably quasi-fluids or biological tissues, based on the separation of non-linear parameters.

Example systems and methods for nondestructive ultrasonic testing are provided. One example system includes at least one air-coupled ultrasonic transducer configured to emit primary ultrasound waves that interfere with each other. The primary ultrasound waves include fundamental frequency components that are multiples of each other and emitted simultaneously in locked phase. Further, the interference of the primary ultrasound waves generates a plurality of frequency harmonics in the air. The system also includes at least one receiver configured to receive ultrasonic waves emitted from an object under test.