Abstract: An optical-acoustic transducer structure includes at least one metal or semiconducting film in which a part of a pump light pulse is absorbed to generate a sound pulse; and at least one dielectric film. The thicknesses and optical properties of the at least one metal or semiconducting film and the at least one dielectric film are selected so that a returning sound pulse results in a measurable change in the optical reflectivity and/or some other optical characteristic of the transducer structure. The transducer structure includes a resonant cavity, and an output surface that is shaped so as to provide no significant focusing of generated sound waves when the sound waves are launched towards a surface of the sample.

Abstract: A method for measuring variations of the surface of an object using acoustic energy in the audio range is provided. Imaging fine surface roughness on the order of few microns is achievable by using a vibroacoustography technique. This technique provides a method for imaging surface roughness on the basis of an ultrasound radiation force that stimulates acoustic emissions at an ultrasound standing wave field. The present invention may be employed as a tool for the nondestructive inspection and imaging of the surface variations of an object.

Abstract: An EMAT that generates horizontally polarized shear ultrasonic waves is combined with a PZT that generates longitudinal ultrasonic waves to provide simultaneous or sequential inspection of a test component material for improved accuracy in estimating properties of the material or detecting and estimating the dimensions of defects in the material. The transducer combination is constructed so that the EMAT and PZT elements are concentric and therefore interrogate approximately the same volume of the test component material. Nonferromagnetic insulators, such as elastomers, are installed on the bottom surface of PZT component to increase the transmission and reception the ultrasonic waves into the test component. Ferromagnetic, acoustic-absorbing materials are installed on the top surface of the EMAT coil component to minimize generation of ultrasonic waves in the bias magnet.

Abstract: Techniques for determining lateral offset of the source of an acoustic disturbance in a distributed acoustic fibre optic sensor are described. The sensor comprises an optical source (112) for interrogating an optical fibre (104) and a detector (116) and processor (108) arranged to detect any backscattered radiation and determine a measurement signal for a plurality of discrete longitudinal sensing portions of the optical fibre. The processor is also arranged to analyse the measurement signals to identify signals corresponding to the same acoustic wave arriving at different parts of the fibre and determine from the time of arrival of said acoustic wave the direction and/or distance of the origin of said acoustic wave from the optical fibre. The geometry of the fibre may be arranged to ensure that any positional ambiguity can be resolved and the use of multiple fibres (501, 502) is disclosed.

Abstract: Certain embodiments of the invention may include systems and methods for measuring turbine blade vibratory responses. According to an example embodiment of the invention, a method is provided for measuring a vibratory response of a plurality of turbine blades. The method can include mounting an optical probe comprising at least one probe tip optical surface, wherein the at least one probe tip optical surface is substantially parallel to within about +15 or about ?15 degrees with respect to a trailing edge surface of at least one of the plurality of turbine blades, directing light towards a trailing edge surface of at least one of the plurality of turbine blades, receiving reflected light from the at least one of the plurality of turbine blades, and determining relative position of the at least one of the plurality of blades based at least in part on the reflected light.

Abstract: There is provided an optical microphone for detecting an acoustic wave propagating in an ambient fluid, the optical microphone including: a propagation medium section; a light source for emitting a light wave to be transmitted through a diffraction region in the propagation medium section; and a photoelectric conversion section for detecting the light wave having been transmitted through the propagation medium section. A first acoustic wave which is a portion of the acoustic wave and a second acoustic wave which is another portion thereof are allowed to propagate in the propagation medium section so as to simultaneously arrive at the diffraction region, and an interference component between a +1st order diffracted light wave and a ?1st order diffracted light wave of the light wave generated based on a refractive index distribution of the propagation medium occurring in the diffraction region.

Abstract: An ultrasonic probe for optical detection of ultrasonic waves includes a membrane integrated into the probe for contact with a body, the membrane being excited to vibration by reflected ultrasonic waves, leading to a change in optical path length of a beam of light directed at the membrane, which change is determined interferometrically.

Abstract: A new invention for the laser-based generation of ultrasound is described. In conventional laser-based ultrasound, a pulse of light is incident on a solid. The light is converted to heat expanding the material near the surface. This thermoelastic expansion creates an acoustic wave in the material. Detection of the ultrasound allows the nondestructive inspection of the material. The rate of performing an ultrasound scan is inherently limited by the pulse rate of the laser. In this invention, a continuous wave (cw) high-power laser sweeps across the material, using thermoelastic expansion to create an ultrasound wavefront on the surface of and in the material. Detection of the ultrasound wavefront provides evidence of the strength of the material and the presence of defects. With Continuous Laser Generation of Ultrasound, material analysts will be able to perform ultrasound scans potentially hundreds of times faster than the current methods.

Abstract: Designs of single-beam laser vibrometry systems and methods.

Abstract: A system generates a photoacoustic spectrum in an open or closed environment with reduced noise. A source focuses a beam on a target substance disposed on a base. The base supports a cantilever that measures acoustic waves generated as light is absorbed by the target substance. By focusing a chopped/pulsed light beam on the target substance, a range of optical absorbance may be measured as the wavelength of light changes. An identifying spectrum of the target may detected by monitoring the vibration intensity variation of the cantilever as a function of illuminating wavelength or color.

Abstract: Apparatus and method for non-contact (stand-off) ultrasonic determination of certain characteristics of fluids in containers or pipes are described. A combination of swept frequency acoustic interferometry (SFAI), wide-bandwidth, air-coupled acoustic transducers, narrowband frequency data acquisition, and data conversion from the frequency domain to the time domain, if required, permits meaningful information to be extracted from such fluids.

Abstract: The invention pertains to the design, arrangement and fabrication of arrays of electromagnetic acoustic transducers (EMATs) for detection and monitoring of defects in metal components while they are being used in service. Emphasis is placed on printed circuit sensor coil designs that are attached to and covered with thin, flexible and insulating substrates. This laminated construction with additional means for electrical and thermal insulation, radiation heat shielding and simple cooling provides for consistent and reliable EMAT performance in monitoring components at elevated temperatures. The arrays include circular spiral coils, elongated spiral (racetrack) coils and rectangular spiral coils. Also described are arrays of dual-rectangular (butterfly) coils, meander coils and trapezoidal coils. Various assembly designs for the attachment of bias magnets are described.

Abstract: A portable non-contact sensor system including a laser generator subsystem, a laser detector subsystem, a beam steering subsystem, an analysis subsystem, a power management subsystem, a user interface, and a communications interface. The laser generator subsystem is configured to project a plurality of laser pulses at a surface of an object that is to be characterized. The laser detector subsystem is configured to receive return laser pulses from the object. The analysis subsystem is configured to analyze the received return pulses and characterize the object.

Abstract: The invention relates to a method for nondestructive testing of a metallic workpiece (11) using an ultrasonic transducer testing head having the following steps: to generate an ultrasonic wave, an excitation pulse is transmitted using the ultrasonic transducer (1) to the workpiece (11), a response signal is measured using the magnetic field sensor (3), testing information, preferably transit time information of the ultrasonic wave and therefrom wall thickness information about the thickness of the workpiece (11), is ascertained on the basis of an ultrasonic echo component of the response signal, and further information, in particular distance information about the distance of the testing head from the workpiece (11), is ascertained on the basis of a magnetic field component of the response signal by supplementary analysis.

Abstract: A surface inspecting method for inspecting a flaw of a test object using a surface wave and estimating a depth of the flaw of the test object from an attenuation ratio of a frequency of a generation wave, the surface inspecting method including calculating a power spectrum of generation wave generating the flaw of the test object; integrating the power spectrum of the generation wave passing the flaw of the test object and calculating an integration value thereof; converting the integration value into a flaw depth based on a calibration created beforehand and calculating the flaw depth of the test object; and displaying the calculated flaw depth of the test object.

Abstract: A mid infrared range laser source for ultrasound inspection having a high energy laser coupled with one or more harmonic generation devices. The high energy laser may be a CO2 laser and tuned to emit laser light at a single wavelength. The harmonic generation devices convert the laser beam into the mid infrared range for optimal ultrasound inspection.

Abstract: A device is disclosed for material testing on a test object having at least electrically conducting and ferromagnetic material parts. The test object has at least one technical surface on which at least one electromagnetic ultrasonic transducer (EMUS) is rolled. The at least one transducer includes at least one permanent magnet or an electromagnet and at least one eddy current coil. The at least one eddy current coil has at least one electrical strip conductor which is disposed at or parallel to a surface area of a rolling member which can be rolled on the technical surface of the test object, with the surface area rolling along with the rolling member during rolling.

Abstract: Generally speaking, the method of the present invention is performed by making various ultrasonic scans at preselected orientations along the length of a material being tested. Data from the scans are then plotted together with various calculated parameters that are calculated from this data. Lines or curves are then fitted to the respective plotted points. Review of these plotted curves allows the location and severity of defects within these sections to be determined and quantified. With this information various other decisions related to how, when or whether repair or replacement of a particular portion of a structure can be made.

Abstract: An electromagnetic-acoustic transducer for ultrasonic testing of test objects which are composed substantially of an electrically conductive material includes a magnet system that produces a magnetic field intended to penetrate into the test object, and an inductive coil arrangement that produces an electromagnetic alternating field superimposed on this magnetic field in the test object, and that detects electromagnetic alternating fields emitted from the test object, wherein magnet system is arranged in a magnetization unit, the coil arrangement is arranged in a probe unit separate from the magnetization unit, the probe unit is mounted such that it can move relative to the magnetization unit in the area of the magnetic field.

Abstract: A combined electromagnetic acoustic transducer (EMAT) is disclosed that uses magnetic shielding to increase the efficiency (defined as the received signal per unit of excitation current). In addition, electromagnetic shielding may also be used to reduce the direct coupling between the transmit and receive coils.

Abstract: The invention relates to a device and a method for testing the material of a test object (4) which contains at least electrically conductive and ferromagnetic material fractions and has at least one engineered surface (5), by means of at least one electromagnetic ultrasonic transducer assembly (EMUS). Said assembly comprises a permanent or electromagnetic assembly (1) comprising at least two magnetic poles (N, S) of different magnetic polarity that face the engineered surface (5), in addition to an eddy current coil (2) that is placed in close proximity to the engineered surface (5) between the two magnetic poles (N, S) in indirect or direct relation to the engineered surface (5). The invention is characterized in that the eddy current coil (2) is configured and arranged in such a way that when said coil (2) is supplied with an alternating current, free ultrasonic waves that run essentially perpendicular to the engineered surface (5) are generated and propagate inside the test object (4).

Abstract: The present invention provides a flexible noncontact source of wave energy through the use of time reversal. In the preferred embodiment a differential laser vibrometer is employed to measure the vibration of a sample surface. Thus, the time reversal noncontact source can be configured to provide an out of plane vibration source or an in plane vibration source, or any combination of the two.

Abstract: A mode of the present invention includes a transmitter (12) for shooting exciting laser light to an object of measurement (M) to excite ultrasonic waves in the object of measurement (M), a receiver (14) for shooting probing laser light to the object of measurement (M) to receive reflected light of probing laser light from the object of measurement (M) for detection of ultrasonic waves, a light blocking structure (16) having a first opening (16a) allowing the object of measurement (M) to pass therethrough and operable to accommodate the object of measurement (M), and a cover (18) operable to cover and open the first opening (16a).

Abstract: Inspection of rolling stock (e.g., rail vehicles) traveling along a set of rails is performed using devices that are placed in a housing that is attached to the set of rails. The housing conforms to standard width, height, and load bearing requirements for a railroad tie. As such, the housing can be readily installed and allows for the continued use of standard railroad maintenance equipment. One or more sensing devices are attached to the housing and acquire evaluation data on component(s) of the rail vehicle, such as the wheels. A computing device can evaluate a condition of the component(s) using the evaluation data.

Abstract: An optical fiber vibration sensor includes a light source, an optical receiver, an optical dividing/coupling portion, a signal processing unit, and a fiber loop portion made of an optical fiber. A part of an optical fiber composing the fiber loop portion is installed inside a housing of a main body of the optical fiber vibration sensor as an optical fiber for delay and another part of the optical fiber composing the fiber loop portion is installed outside the housing as a vibration detecting optical fiber.

Abstract: Forces are applied to a device under test and its mechanical response is measured by a laser vibrometer (50). The forces are applied without making physical contact with the device by producing an acoustical force with an ultrasonic beam (54). One embodiment employs two confocal transducers (56, 58) that produce beams that flood the device. Drive signals modulate the ultrasonic beams to produce the desired forces, and the use on a plurality of ultrasonic beams enable selective excitation of different modes of vibration of the object (7).

Abstract: A method and device are disclosed for evaluating received signals acquired during non-destructive ultrasonic testing of a test body, wherein ultrasound waves are generated inside the test body with an electromagnetic ultrasonic transducer acting as an ultrasound transmitter and ultrasound waves which propagate within the test body are converted into received signals with an electromagnetic ultrasonic transducer acting as an ultrasound receiver. The received signals are evaluated for the purpose of examining the test body.

Abstract: Methods and apparatus for acquiring and processing data from a plurality of different sensor types for non-destructive testing of metallic structures. An electromagnetic acoustic transducer (EMAT) signal, an eddy current (EC) signal, a magnetic flux leakage (MFL) signal, and a deflection signal are acquired from each of a plurality of localized regions of a metallic structure, and are processed to characterize one or more features of the metallic structure based on at least two of the EMAT, EC, MFL, and deflection signals acquired from a common localized region in which at least a portion of the feature is located. An integrated multi-sensor device for non-destructive may be used to provide the EC, EMAT, MFL, and deflection signals for each of the plurality of localized regions of the metallic structure. Such integrated multi-sensor devices may be configured to provide an in-line inspection tool, such as an intelligent pig that is used to inspect the integrity of pipelines.

Abstract: The present invention is to provide inspection apparatus and method of being able to acquire electromagnetic wave response information of an inspection object at high speed as average information using an electromagnetic wave. An inspection apparatus using an electromagnetic wave 2 includes an electromagnetic wave generation and irradiation unit 9 which generates an electromagnetic wave and irradiates the electromagnetic wave on an inspection object 11, and an electromagnetic wave detection unit 10 having a plurality of detection units. The plurality of detection units is arranged so as to detect the electromagnetic wave which is irradiated by the electromagnetic wave generation and irradiation unit and is transmitted or reflected with interacting with different sites of the inspection object 11, and is constructed so as to detect the electromagnetic wave from the different sites in different detection time or detection frequencies respectively.

Abstract: An electromagnetic ultrasonic flaw detection method is provided which ensures highly accurate inspection of an interior surface of a fin-implanted heat transfer tube for detection of corrosion and requires less time for the inspection, no contact medium such as water, and less time and less costs for a pretreatment. The method may include moving an EMAT in a fin-implanted heat transfer tube of an air cooling heat exchanger axially of the tube; causing the EMAT to generate an axially symmetric SH wave by utilizing an electromagnetic force to vibrate a tube body of the fin-implanted heat transfer tube to cause resonance; causing the EMAT to detect a resonant frequency; and if the detected resonant frequency is different from a resonant frequency observed when the tube body has a normal wall thickness, judging that an interior surface of the tube body has a corroded portion.

Abstract: A device for destruction-free testing of ferromagnetic component walls with respect to elongate defects has a sending transducer that excites ultrasound waves in a wall area of a ferromagnetic component wall magnetized in a predetermined direction of magnetization. The ultrasound waves propagate on a path oriented by the sending transducer. A receiving transducer receives the ultrasound waves at a spacing from the sending transducer. The configuration of the sending transducer and a high frequency emitted by the sending transducer, which high frequency is to be determined based on a thickness of the ferromagnetic component wall, are selected so as to effect excitation of horizontal shear waves of higher order. The path orientation is selected at a slant angle to the predetermined direction of magnetization. The receiving transducer is positioned lateral to the path and is oriented toward a predetermined testing area of the wall section in the path.

Abstract: An ultrasonic non-destructive evaluation (NDE) system operable to inspect target materials is provided. This ultrasonic NDE system includes an articulated robot, an ultrasound inspection head, a processing module, and a control module. The ultrasound inspection head couples to or mounts on the articulated robot. The ultrasound inspection head is operable to deliver a generation laser beam, a detection laser beam, and collect phase modulated light scattered by the target materials. The processing module processes the phase modulated light and produces information about the internal structure of the target materials. The control module directs the articulated robot to position the ultrasound inspection head according to a pre-determined scan plan.

Abstract: An acoustic sensor comprises at least one resonant element. A driver comprises an electrical coupling means and an electromagnetic field source arranged such that the electrical coupling means transfers currents to the electromagnetic field source. The electromagnetic field source produces an electromagnetic field that drives the resonant elements to produce acoustic waves directed to a predetermined part of a test sample. Also provided is an electromagnetic detector for receiving the acoustic spectrum omitted from a test sample and an electrical circuit connected to the drive around detector.

Abstract: A laser ultrasonic device is disclosed. The laser ultrasonic device comprises an ultrasonic generation system capable of generating ultrasonic waves on a surface of a sample, said system comprising a first collection of optical fiber output ends arranged in a first pattern.

Abstract: A laser transmission system is used for inspecting workpieces. The system has a source of laser beams that is coupled to a first lens assembly. A first hollow core waveguide is operably coupled to the first lens assembly. An end of an optical fiber coupled to the first hollow core waveguide. A second hollow core waveguide is coupled to the other end of the optical fiber. A second lens assembly operably coupled to the second hollow core waveguide. The length of the hollow core waveguides range from about 5 to 100 times the focal lengths of the lens assemblies. A motion control system is operably coupled to the second hollow core waveguide and the second lens assembly for controllably displacing the second hollow core waveguide and the second lens assembly with respect to a workpiece.

Abstract: The electromagnetic acoustic transducer (EMAT) transducer disclosed herein is useful for the non-destructive analysis of objects. The transducer comprises a core having a winding and a coil disposed between the core and the object to be analyzed. One transducer can be used as a transmitter and another transducer as a receiver. Then selectively switching static magnetic field in either transmitter or receiver and processing data with and without static magnetic field allows for eliminating artifacts due to parasitic coupling between the transmitter/receiver pair. The switching of the static magnetic field can be implemented either by using electromagnet or a pair of permanent magnets where magnetization of one permanent magnet is reversed to provide cancellation of the static magnetic field.

Abstract: Ultrasonic inspection system, method, and apparatus for subsurface ultrasonic inspection of curved objects. The inspection system includes an apparatus having a support structure for supporting a selected transducer and a selected acoustic mirror adapted for immersion in a coupling fluid. The total inspection path distance for the ultrasonic radiation includes a first portion defined by the transducer-to-mirror distance, and a second portion including the mirror-to-object distance. The first and second portions may be relatively adjusted within a constant total inspection path distance to focus the ultrasonic radiation at a desired subsurface depth. Selection of the transducer is at least partly dependent on subsurface depth of the desired inspection zone. Selection of the acoustic mirror is at least partly dependent on the selected transducer, the total inspection path distance, and curvature of the inspection object.

Abstract: A method of predicting at least one physical change in crack geometry of a crack in a pipeline based on in-line inspection operating pressure is presented. In one method, a first test on a pipeline is performed at a first pressure, which obtains a first set of test data. A second test is performed on the pipeline at a second pressure, obtaining a second set of test data. The first and second sets of test data are compared for any difference. A run comparison software processing device may be employed. In other methods, finite element analysis of crack-like dimensions is performed to predict Crack Mouth Opening Displacement (CMOD) for a given set of crack dimensions for a surface-breaking crack and inline pipe inspection operating run pressure. Another method predicts probability of detection of a crack associated with a given CMOD as a function of pressure in successive inspections.

Abstract: A combined electromagnetic acoustic transducer (EMAT) is disclosed adapted to generate both SH-type acoustic waves and LAMB-type acoustic waves in a conductive casing, surroundings of which are to be analyzed. The transducer comprises one magnet assembly and two RF coils implemented as multi-layer printed circuit board. Each coil is used to generate or receive acoustic signals of one wave type. Compared to using two single-wave-type transducers the combined EMAT significantly reduces total attraction force to the casing and, correspondingly, simplifies mechanics of the measurement tool. It is emphasized that this abstract is provided to comply with the rules requiring an abstract which will allow a searcher or other reader to quickly ascertain the subject matter of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims.

Abstract: An ultrasonic inspection apparatus is provided in which the size of the apparatus can be made compact by using laser light, the degradation and deformation of the inspected object is prevented, and a broad range of inspections can be carried out. An ultrasonic inspection apparatus (1) is provided with a laser apparatus (5) that irradiates laser light and a volumetric inspection ultrasonic wave transmitter (17) having a transmitting diaphragm (39) that is irradiated by the laser light emitted by the laser apparatus (5) and that generates ultrasonic waves (C); and the ultrasonic inspection apparatus (1) carries out volumetric inspections by irradiating the ultrasonic waves (C) that are generated by the transmitting diaphragm (39) of the ultrasonic wave transmitting portion (17) to the inspected object.

Abstract: A method and apparatus for identifying a sample, involves illuminating the sample with light of varying wavelengths, transmitting an acoustic signal against the sample from one portion and receiving a resulting acoustic signal on another portion, detecting a change of phase in the acoustic signal corresponding to the light of varying wavelengths, and analyzing the change of phase in the acoustic signal for the varying wavelengths of illumination to identify the sample. The apparatus has a controlled source for illuminating the sample with light of varying wavelengths, a transmitter for transmitting an acoustic wave, a receiver for receiving the acoustic wave and converting the acoustic wave to an electronic signal, and an electronic circuit for detecting a change of phase in the acoustic wave corresponding to respective ones of the varying wavelengths and outputting the change of phase for the varying wavelengths to allow identification of the sample.

Abstract: An electromagnetic ultrasonic transducer and an array thereof are provided. This electromagnetic ultrasonic transducer includes a support, an elastic board disposed on the support, a magnetizer on the elastic board, and a magnet field generator for vibrating the magnetizer, wherein, the thickness of the magnetizer is of the order of microns. The thickness of the elastic board is also of the order of microns. This electromagnetic ultrasonic transducer is able to produce acoustic waves of high frequency, which are useful for ultrasonic therapy.

Abstract: The invention relates to a device for controlling a material, said device comprising at least means for transmitting an electromagnetic signal at a carrier frequency Fp to illuminate the material and means for receiving the electromagnetic signal, characterized in that said device further comprises first means for modulating the electromagnetic signal at a frequency Fm1, said modulation means being arranged, on the signal path, between the transmission means and the material in order to spatially sample the emitted electromagnetic signal; second means for modulating the electromagnetic signal at a frequency Fm2, said modulation means being arranged, on the signal path, between the material and the electromagnetic signal reception means in order to spatially sample the electromagnetic signal passed through the material.

Abstract: The invention relates generally to a method of determining the presence of a mineral within a material, such as a rock, a rock fragment, soil, sand or other geological material including: applying pulsed microwave radiation to the material; detecting radiation emitted from the material after the application of the pulsed microwave radiation; and analysing the detected radiation to determine the presence of mineral within the material. The invention also provides a method of sorting rock fragments into at least two streams using this method and an apparatus for carrying out the method.

Abstract: The invention relates to a method for nondestructive testing of a metallic workpiece (11) using an ultrasonic transducer testing head having the following steps: to generate an ultrasonic wave, an excitation pulse is transmitted using the ultrasonic transducer (1) to the workpiece (11), a response signal is measured using the magnetic field sensor (3), testing information, preferably transit time information of the ultrasonic wave and therefrom wall thickness information about the thickness of the workpiece (11), is ascertained on the basis of an ultrasonic echo component of the response signal, and further information, in particular distance information about the distance of the testing head from the workpiece (11), is ascertained on the basis of a magnetic field component of the response signal by supplementary analysis.

Abstract: An ultrasound sensor has an ultrasound oscillator which is expandable and contractible in a thickness direction thereof, and a casing which houses therein the ultrasound oscillator. An outer surface of an end portion of the casing is fixed to a mounting member. The side surface of the ultrasound oscillator has at least one of a protrusion portion, a concave portion and an inclined portion, through which one of two end surfaces of the ultrasound oscillator fixedly contacts an inner surface of the end portion of the casing. The side surface of the ultrasound oscillator is substantially parallel with the thickness direction thereof.

Abstract: A device for nondestructive testing of pipelines is designed to move along a pipeline and has at least one measuring unit for acquiring measured data of the pipeline, wherein the device is self-propelled and has at least one functional unit rotatable about a central axis of the device for acquiring measured data and/or for driving the device. In a corresponding method for nondestructive testing of pipelines, the device is moved along the pipeline by a functional unit having drive elements and moving helically along a surface of the pipeline to be covered. The functional unit acquires measured data and the drive elements are forced by a magnetic field generated by the functional unit against the surface of the pipeline.

Abstract: An opto-acoustic transducer assembly includes a substrate; at least one layer of opto-acoustic material coupled to a surface of the substrate, where the at least one layer of opto-acoustic material generates sound waves when struck by pulses of pump light; and an acoustic lens configured to focus sound waves generated by the at least one layer of opto-acoustic material towards a sample. The acoustic lens is further configured to collect sound waves returning from the sample and to direct the returning sound waves to the at least one layer of opto-acoustic material. The at least one layer of opto-acoustic material is responsive to the returning sound waves for having at least one optical property thereof changed, where the change is detectable from a change in a characteristic of reflected pulses of probe light that are time delayed with respect to the pulses of pump light.

Abstract: A method is shown for magnetostrictive testing of structures using a magnetostrictive strip and magnetostrictive techniques. A torsional guided wave is generated in the magnetostrictive strip which is dry coupled or bonded to the structure. A magnetic field creates an induced bias along the longitudinal axis of the magnetostrictive strip, which magnetic field is sufficiently strong so that when an AC pulse applies an AC bias perpendicular to the induced bias, the AC bias does not override or saturate the induced bias. This allows for an increased signal to noise ratio in a reflected signal indicating a defect in the structure. The induce bias and the AC bias are created by respective windings around the magnetostrictive strip, which windings are perpendicular to each other.

Abstract: Liquids are treated by ultrasound in a flow-through reaction vessel with an elongate ultrasonic horn mounted to the vessel with one end of the horn extending into the vessel interior. The liquid flow path inside the vessel is such that the entering liquid strikes the end of the horn at a direction normal to the end, then flows across the surface of the end before leaving the vessel. The end surface of the horn is positioned in close proximity to the entry port to provide a relatively high surface-to-volume ratio in the immediate vicinity of the horn end. In a further improvement, the horn is joined to an ultrasonic transducer through a booster block that provides an acoustic gain to the ultrasonic vibrations, and the booster block is plated with a reflective metal to lessen any loss of ultrasonic energy being transmitted to the horn.