With the development of the petrochemical industry, pipeline inspection technology plays a vital role in terms of avoiding explosions and protecting people's life and property. Pipelines working in ...high-temperature environments suffer from dual dangers of internal and external wall defects. It is often difficult to find a single nondestructive testing (NDT) method that can cover internal and external defects detection especially in high-temperature environments. In order to discover pipeline defects in time, we propose a hybrid online monitoring method for comprehensive defects inspection in high-temperature environments. This hybrid monitoring method combines eddy current testing (ECT) with electromagnetic acoustic transducer (EMAT) techniques. Specifically, we split the coil signal into two channels; one channel gives ECT signal and the other gives EMAT signal; furthermore, we demonstrate the feasibility of the proposed hybrid monitoring method by numerical simulations and laboratory experiments. The results show that the proposed hybrid online monitoring method can be used successfully to simultaneously monitor surface and internal defects and has high stability even at temperatures above 300 °C. Our approach achieves the genuine integration of ECT/EMAT technologies, effectively addressing the challenge of incomplete monitoring of pipeline defects in high-temperature environments.
Flexible mechanical sensors are essential components for smart wearables. Conventional resistive, capacitive, or transistor-based mechanical sensors consume energy continuously, while piezoelectric ...and triboelectric sensors respond selectively to dynamic or transient mechanical stimulations. Developing mechanical sensors that do not necessitate external power supply but are able to monitor static mechanical stimuli can compensate for the deficiencies of existing sensing devices. Here, we present the facile construction of a new paradigm of electrochemical mechanical sensors based on ubiquitous metallic corrosion effects. The intrinsic differences in corrosion activities of diverse metals (e.g., zinc, aluminum, copper, etc.) are utilized to create potential differences between two electrodes, followed by encoding external mechanical stimulations into the potential difference variations via carefully selected solid electrolytes. The developed electrochemical mechanical sensors exhibit comparable performance (e.g., sensitivity, recovery/response speed, reproducibility, etc.) with that of conventional sensors, but possess significantly superior simplicity, cost-efficiency, and desirable capability in resolving static or slowly-varying mechanical stimulations in a self-powered manner. As proof-of-concept demonstrations, machine learning enabled speech recognition with high accuracy of 99.07% and monitoring of diverse human physiological activities are successfully demonstrated. These proposed unique electrochemical mechanical sensors based on the ubiquitous metallic corrosion phenomena provide a simple but effective approach for the burgeoning human-machine interfacing requirements with great benefit to the resource efficiency and sustainability of our society.
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•A new paradigm of electrochemical mechanical sensors based on ubiquitous metallic corrosion effects is presented.•The electrochemical sensors do not necessitate external power supply but are able to monitor static mechanical stimuli.•The sensors exhibit desirable sensing performance and possess superior simplicity and cost-efficiency.•Machine learning enabled speech recognition with high accuracy of 99.07% is demonstrated with such sensors.•Diverse human physiological activities can be monitored with the electrochemical sensors.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Ultrasonic liquid level measuring technology has been extensively applied in the industrial field, which is characterized by its high accuracy, strong ability of anti-electromagnetic interference and ...simple structure. However, its measurement results are easily affected by the tilt of liquid level and ripple. In this study, the traditional gas-liquid interface was transformed into a solid-liquid interface based on the acoustic scattering by a rigid sphere and a circular waveguide, and the liquid level was measured with the stable reflecting surface by complying with the liquid level in the duct. Such a method could overcome the effect of the tilt of liquid level and ripple on the measurement results. In this study, a signal processing method to improve the signal to noise ratio of the direct wave was proposed. To improve the sound intensity of the direct wave and reduce the effect of high-order mode waves on the signal, the transceiver was applied with a matching layer, and the appropriate waveguide material should be selected to absorb a portion of high-order mode waves. As revealed from the experimentally achieved results, an optimized lightweight ultrasonic liquid level sensor was proposed to eliminate the effect of ripple, and the tilt of liquid level increased from 20° to 60°.
