A method of performing atomic force microscopy (AFM) measurements, uses an ultrasound transducer to transmit modulated ultrasound waves with a frequency above one GHz from the ultrasound transducer to a top surface of a sample through the sample from the bottom surface of the sample. Effects of ultrasound wave scattering are detected from vibrations of an AFM cantilever at the top surface of the sample. Before the start of the measurements, a drop of a liquid is placed on a top surface of the ultrasound transducer. The sample is placed on the top surface of the ultrasound transducer, whereby the sample presses the liquid in the drop into a layer of the liquid between the top surface of the ultrasound transducer and a bottom surface of the sample. The AFM measurements are started after a thickness of the layer of the liquid has stabilized.

According to one implementation, a damage detection system includes: a physical quantity detection unit, a flight condition changing part and a damage detection part. The physical quantity detection unit detects a physical quantity of a structural object composing an aircraft during a flight of the aircraft. The flight condition changing part changes at least one flight condition of the aircraft to at least one specific flight condition when the physical quantity of the structural object has been detected by the physical quantity detection unit. The damage detection part determines whether a damage arose in the structural object, based on a physical quantity which has been detected, from the structural object of the aircraft flying with the at least one specific flight condition, by the physical quantity detection unit.

A method for testing a body having a feature and an outer surface includes configuring a probe to emit a focused ultrasonic beam; configuring a control unit to control the probe, adjusting a focal distance of a focal point of the beam with reference to a test location; adjusting a position of the focal point along at least one axis with reference to the feature; emitting the beam into the outer surface; and determining a presence of a crack at the test location by evaluating % a signal response from the probe. A related apparatus includes the control unit, the transducer, and a shoe assembly having a shoe member and a shoe adapter. A coupling fluid in a variable volume chamber in the shoe adapter separates the transducer from the shoe member and allows changes in a focal distance of the focal point. The apparatus also includes one or more positioners for adjusting a position of the focal point.

The disclosure relates to a method for determining and/or monitoring the breakdown voltage of a transformer oil, comprising the steps of a) performing an acoustic impedance measurement of the transformer oil, the impedance of a medium partially or entirely disposed in the transformer oil and capable of naturally vibrating and/or transmitting vibrations to the transformer oil is determined in at least one frequency band of defined frequency width; and b) calculating a resonator quality factor for the frequency band based on the determination performed in step a); and c) calculating an acoustic disbalance of the transformer oil based on the calculation performed in step b); and d) ascertaining the breakdown voltage of the transformer oil based on the calculation performed in step c). Furthermore, the disclosure relates to a device (100, 200) for determining and/or monitoring the breakdown voltage of a transformer oil.

An acoustic sensor system for an aircraft, and method for operating the same, includes a transmitter, at least one microphone, and a control circuit. The transmitter is configured to emit acoustic signals external to the aircraft. The at least one microphone is positioned on an exterior of the aircraft and configured to sense the acoustic signals as sensed data. The control circuit is configured to receive the sensed data and control the transmitter through a drive circuit, and is configured to detect an environmental condition and control the transmitter to emit the acoustic signals at a reduced intensity based on the detected environmental condition.

A method for testing a body having a feature and an outer surface includes configuring a probe to emit a focused ultrasonic beam; configuring a control unit to control the probe, adjusting a focal distance of a focal point of the beam with reference to a test location; adjusting a position of the focal point along at least one axis with reference to the feature; emitting the beam into the outer surface; and determining a presence of a crack at the test location by evaluating % a signal response from the probe. A related apparatus includes the control unit, the transducer, and a shoe assembly having a shoe member and a shoe adapter. A coupling fluid in a variable volume chamber in the shoe adapter separates the transducer from the shoe member and allows changes in a focal distance of the focal point. The apparatus also includes one or more positioners for adjusting a position of the focal point.

A transducer system. The system comprises a transducer and circuitry for applying an excitation waveform to excite the transducer during an excitation period. The circuitry for applying has: (i) circuitry for applying a first waveform at a first frequency; and (ii) circuitry for applying a second waveform at a second frequency differing from the first frequency.

Disclosed herein a method of producing an ultrasound that includes defining a set of criteria for an ultrasound emitter comprising a plate. The set of criteria includes a power output criterion, a frequency criterion and number of nodes for a resonance mode of the plate, a focus criterion, and a durability criterion. The method includes determining an outline and a thickness range for the plate, based on the set of criteria. The method includes using topology optimization to determine internodal zone dimensions for the plate, based on the set of criteria, the outline, and the thickness range. The method includes manufacturing the plate according to the internodal zone dimensions.

A method is provided for generating ultrasound transmission waves comprising: a) providing an array of electroacoustic transducer elements each one being connected to an electric excitation signal generator by a dedicated feeding channel; b) feeding at least a part of the electroacoustic transducer elements with a pulsed electric signal having a predetermined frequency, a predetermined amplitude, a predetermined length or duration and a predetermined phase or a predefined delay with respect to the pulsed electric signals fed to the adjacent transducer elements, the said pulsed electric excitation signals comprising a sequence of pulses; c) modulating each or at least part of the pulsed electric signals by feeding to the transducer elements only a predetermined portion of the pulses of the said pulsed electric signals. Modulating is carried out by cutting the duration of each pulse of the pulsed electric excitation signal according to a predetermined time period.

Systems and methods to measure states of charge of a battery may include an ultrasonic sensor and a control system. For example, the control system may instruct the ultrasonic sensor to emit ultrasonic waves toward a battery, and may instruct the ultrasonic sensor to receive echoes of the emitted ultrasonic waves reflected back from the battery. In addition, the control system may process data associated with the emitted waves and received echoes, including properties associated with the waves and echoes, such as a time of flight, frequency, amplitude, wavelength, phase, duration, or others. Based on the properties of the received echoes, and by comparison with expected properties, various physical, mechanical, chemical, and/or material characteristics of the battery may be determined, based on which a state of charge and/or a state of health of the battery may further be determined.