The present disclosure proposes a non-baseline on-line stress monitoring system and monitoring method based on multi-mode Lamb wave data fusion. A Lamb wave dispersion curve is established according to geometric dimensions and material parameters of a measured object, a cut-off frequency of a first-order Lamb wave mode is obtained, an excitation frequency of a Lamb wave signal is determined, and then pure Lamb waves in S0 and A0 modes obtained inside the measured object are obtained; an acoustoelastic equation is established, an elastodynamic equation of the measured object under a prestress condition is solved, and linear relationships between a group velocity and a stress of the Lamb waves in the S0 and A0 modes under the excitation frequency are obtained; data is processed through the on-line monitoring system; a stress gradient in a depth direction is calculated, and finally, a stress state of the measured object is represented. The present disclosure does not require data under a zero stress state as baseline data, does not require designing a wedge block capable of generating a critical refraction longitudinal wave, and combines acoustoelastic effects of Lamb waves in different modes to realize online stress monitoring without the baseline data.

The present disclosure proposes a non-baseline on-line stress monitoring system and monitoring method based on multi-mode Lamb wave data fusion. A Lamb wave dispersion curve is established according to geometric dimensions and material parameters of a measured object, a cut-off frequency of a first-order Lamb wave mode is obtained, an excitation frequency of a Lamb wave signal is determined, and then pure Lamb waves in S0 and A0 modes obtained inside the measured object are obtained; an acoustoelastic equation is established, an elastodynamic equation of the measured object under a prestress condition is solved, and linear relationships between a group velocity and a stress of the Lamb waves in the S0 and A0 modes under the excitation frequency are obtained; data is processed through the on-line monitoring system; a stress gradient in a depth direction is calculated, and finally, a stress state of the measured object is represented. The present disclosure does not require data under a zero stress state as baseline data, does not require designing a wedge block capable of generating a critical refraction longitudinal wave, and combines acoustoelastic effects of Lamb waves in different modes to realize online stress monitoring without the baseline data.

A connector assembly and method of attaching the same to one or more biosensor module boards. The connector assembly includes a body portion defining a first surface and a second surface opposite the first surface. The connector assembly also includes a coaxial RF connector positioned in the body portion and extending between the first surface and the second surface. The coaxial RF connector includes a ground ring, an RF pin positioned within the ground ring, and dielectric therebetween. The connector assembly is configured to be coupled to an RF detection board such that the coaxial RF connector is operably coupled thereto. The connector assembly is also configured to be connected to a biosensor module board such that the coaxial RF connector is operably connected thereto.

Methods, systems, and apparatus, including computer programs encoded on computer-storage media, for self-calibrating ultrasonic removal of sea lice. In some implementations, a method includes generating, by transducers distributed in a sea lice treatment station, a first set of ultrasonic signals, detecting a second set of ultrasonic signals in response to propagation of the first set of ultrasonic signals through water, determining propagation parameters of the sea lice treatment station based on the second set of ultrasonic signals that were detected, obtaining an image of a sea louse on a fish in the sea lice treatment station, determining, from the image, a location of the sea louse in the sea lice treatment station, and generating a third set of ultrasonic signals that focuses energy at the sea louse.

An ultrasound circuit comprising a trans-impedance amplifier (TIA) with built-in time gain compensation functionality is described. The TIA is coupled to an ultrasonic transducer to amplify an electrical signal generated by the ultrasonic transducer in response to receiving an ultrasound signal. The TIA is, in some cases, followed by further analog and digital processing circuitry.

An ultrasound circuit comprising a trans-impedance amplifier (TIA) with built-in time gain compensation functionality is described. The TIA is coupled to an ultrasonic transducer to amplify an electrical signal generated by the ultrasonic transducer in response to receiving an ultrasound signal. The TIA is, in some cases, followed by further analog and digital processing circuitry.

A concentration measuring instrument includes a piezoelectric vibrator transmitting an ultrasonic wave into a solution contained in a cavity and detecting the ultrasonic wave reflected, a temperature sensor measuring a temperature of the solution, a drive circuit generating a drive signal driving the piezoelectric vibrator, a phase comparator performing a phase comparison between the drive signal and a detection signal, a frequency setting circuit making the drive circuit generate drive signals having sequentially different frequencies and monitoring a phase comparison result to detect a resonant frequency, and a Phase Locked Loop (PLL) circuit making a frequency of the drive signal follow the detected resonant frequency. A microcomputer determines a concentration of a solute in the solution on a basis of the frequency of the drive signal while the PLL circuit is being operated and a result of a temperature measurement by the temperature sensor.

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.

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.

Methods, systems, and apparatus, including computer programs encoded on computer-storage media, for self-calibrating ultrasonic removal of sea lice. In some implementations, a method includes generating, by transducers distributed in a sea lice treatment station, a first set of ultrasonic signals, detecting a second set of ultrasonic signals in response to propagation of the first set of ultrasonic signals through water, determining propagation parameters of the sea lice treatment station based on the second set of ultrasonic signals that were detected, obtaining an image of a sea louse on a fish in the sea lice treatment station, determining, from the image, a location of the sea louse in the sea lice treatment station, and generating a third set of ultrasonic signals that focuses energy at the sea louse.