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Nonlinear Ultrasonic Detection Method for Delamination Damage of Lined Anti-Corrosion Pipes Using PZT Transducers
摘要： Lined anti-corrosion pipes are widely used in oil and gas, petrochemical, pharmaceutical industries. However, defects, especially delamination, may occur in the production and service of pipes which result in safety accidents. Based on nonlinear ultrasonic theory, this paper studied the delamination detection method using the nonlinear harmonics for lined anti-corrosion pipes. The response characteristics of the anti-corrosion pipe were obtained through a sweep sine response experiment and the preferred excitation frequency was determined. The Wavelet Packet transform and Hilbert–Huang transform is applied for signal process and feature extraction. Then, a series of experiments were carried out and the results were analyzed and discussed. The results showed that a second-order and third-order nonlinear coefficient increased with the delamination damage. The amplitude of second-harmonic is much stronger than the third-order one. The mean squared error of the nonlinear coefficient, which was processed by Wavelet Packet transform and Hilbert–Huang transform, is smaller than wavelet packet transform and Discrete Fourier transform or processed only Hilbert–Huang transform. The higher harmonics can describe the change of delamination damage, which means that the nonlinear ultrasonic detection method could use for damage detection of anti-corrosion pipe. The nonlinear higher-harmonic is sensitive to delamination damage. The nonlinear ultrasonic method has the potential for damage detection for lined anti-corrosion pipes.
关键词： lined anti-corrosion pipes,Hilbert–Huang transform,delamination damage,nonlinear ultrasonic,wavelet packet transform
更新于2025-09-19 17:15:36
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Sonochemical Reaction to Control the Near Infrared Photoluminescence Properties of Single-Walled Carbon Nanotubes
摘要： The effect of ultrasonic irradiation on the optical properties of single-walled carbon nanotubes (SWNTs) was investigated. Upon sonication in D2O in the presence of sodium dodecylbenzene sulfate (SDBS) under air, red-shifted photoluminescence (PL) peaks at ~1043 and ~1118 nm were observed from aqueous suspensions of (6,4) and (6,5)SWNTs, accompanied by a decrease in the intensity of the intrinsic PL peaks. Upon sonication with SDBS under Ar atmosphere, the rate of spectral change increased with the sonication time and new PL peaks emerged at 1043, 1118, and 1221 nm. Meanwhile, upon the addition of 1-butanol, PL peaks emerged only at 1043 nm and 1118 nm, while the emergence of that at 1221 nm was inhibited. On the other hand, a suspension with highly dispersed SWNTs was obtained upon sonication in the presence of sodium cholate without any change in the intrinsic optical properties of SWNTs. These experimental results reveal that the PL characteristics of SWNTs can be controlled by controlling the sonication conditions such as the type of surfactant used, the concentration of SWNTs, reaction environment, and the presence of an inhibitor such as 1-butanol.
关键词： single-walled carbon nanotubes,surfactant,sonochemical reaction,photoluminescence,ultrasonic irradiation
更新于2025-09-19 17:13:59
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[IEEE 2019 IEEE International Conference on Sensors and Nanotechnology (SENSORS & NANO) - Penang, Malaysia (2019.7.24-2019.7.25)] 2019 IEEE International Conference on Sensors and Nanotechnology - Effect of Laser Power on the Formation of Porous Graphitic Carbon on Polyimide Film
摘要： This paper proposes a new linear ultrasonic motor using hybrid mode of the first symmetric and anti-symmetric longitudinal modes. The stator is constructed by two Langevin transducers in combination with two isosceles triangular beams. The triangular beams can transform the displacement in axial direction into the displacement in perpendicular direction and generate the oval trajectory of the driving foot, which is the merit of the simple structure. For better mode degeneration result, the influence of the triangular beam dimensions on the vibration frequency difference of the stator was analyzed by Finite Element Method (FEM) analysis. The overall dimensions of the prototype stator are 70 mm (length) × 15 mm (width) × 10 mm (thickness). Driven by ac signals with the driving frequency of 55 kHz and voltage 400 Vp?p, the motor can provide the no-load speed 63.87 mm/s and maximum thrust force 3.14 N, respectively. The frequency matching process of ultrasonic motor is simplified by adjusting the structure dimensions of the triangular beams.
关键词： Ultrasonic motor,piezoelectric transducer,hybrid mode.
更新于2025-09-19 17:13:59
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Ultrasonic-Enhanced Fabrication of Metal Nanoparticles by Laser Ablation in Liquid
摘要： Laser ablation in liquid (LAL) is known to be a promising method for synthesizing metal nanoparticles. In this study, gold and silver nanoparticles were fabricated by ultrasonic-assisted LAL. Gold and silver plates were ablated using a neodymium-doped yttrium aluminum garnet (Nd:YAG) laser, with a wavelength of 532 nm and energy of 26.4 J cm?2, in distilled water in the presence and absence of an ultrasonic ?eld. The fabricated solution was analyzed with an ultraviolet?visible (UV?vis) nanoparticle colloidal spectrometer, a transmission electron microscope (TEM) with energy-dispersive X-ray spectroscopy (EDS), and ζ-potential measurement. The craters on the silver plates were analyzed by a scanning electron microscope (SEM), a laser microscope, and MATLAB to observe their morphology and calculate the volume to obtain the concentration of the fabricated nanoparticle solution. Optical emissions were observed to study the characteristics of the laser. The results showed that ultrasonic-assisted LAL has considerable potential for fabricating superior metal nanoparticles.
关键词： Silver nanoparticles,Ultrasonic-assisted,Nd:YAG laser,Laser ablation in liquid,Gold nanoparticles
更新于2025-09-19 17:13:59
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Interfacial modification using ultrasonic atomized graphene quantum dots for efficient perovskite solar cells
摘要： Tin dioxide (SnO2) is a promising electron transport material to replace traditional titanium dioxide (TiO2) for fabricating efficient planar perovskite solar cells (PSCs). However, in order to realize process compatibility and larger scale device, low temperature solution processed SnO2 is normally used, which generates numerous trap states in ETL layer and directly affects the device performance. Here, an interfacial modification strategy proposed, depositing an ultrasonic atomized ultrathin graphene quantum dots (GQDs) layer between tin dioxide (SnO2) and perovskite layer. Ultrasonic atomized deposition can effectively prevent the damage of the surface chemical properties of SnO2 by aqueous solution. Additionally, we demonstrate that the GQDs change the surface property of SnO2 film, and optimized the charge transport capability in SnO2 and perovskite interface. Correspondingly, we obtained a significant power conversion efficiency (PCE) improvement for CH3NH3PbI3-based PSCs from 13.61% to 16.54% and reached a highest steady-state PCE over 16%. We believe that the interfacial modification engineering by means of ultrasonic atomizing process is a promising tactic to obtain efficient perovskite solar cells.
关键词： Interface modification,SnO2,Ultrasonic atomizing,Perovskite solar cells,Graphene quantum dots
更新于2025-09-19 17:13:59
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[IEEE 2019 Compound Semiconductor Week (CSW) - Nara, Japan (2019.5.19-2019.5.23)] 2019 Compound Semiconductor Week (CSW) - Multi-wavelength DFB laser array in InAs/GaAs quantum dot material epitaxially grown on Silicon
摘要： A ?rst proof-of-concept mm-sized implantable device using ultrasonic power transfer and a hybrid bi-directional data communication link is presented. Ultrasonic power transfer enables miniaturization of the implant and operation deep inside the body, while still achieving safe and high power levels (100 W to a few mWs) required for most implant applications. The current implant prototype measures 4 mm 7.8 mm and is comprised of a piezoelectric receiver, an IC designed in 65 nm CMOS process and an off-chip antenna. The IC can support a maximum DC load of 100 W for an incident acoustic intensity that is 5% of the FDA diagnostic limit. This demonstrates the feasibility of providing further higher available DC power, potentially opening up new implant applications. The proposed hybrid bi-directional data link consists of ultrasonic downlink and RF uplink. Falling edge of the ultrasound input is detected as downlink data. The implant transmits an ultra-wideband (UWB) pulse sequence as uplink data, demonstrating capability of implementing an energy-ef?cient M-ary PPM transmitter in the future.
关键词： implantable biomedical devices,active recti?er,mm-sized implants,ultrasonic power transfer,piezoelectric receivers,bi-directional data communication,CMOS,antennas,IMD,AC-DC converter,radio transmitters
更新于2025-09-19 17:13:59
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[IEEE 2019 IEEE 4th International Conference on Image, Vision and Computing (ICIVC) - Xiamen, China (2019.7.5-2019.7.7)] 2019 IEEE 4th International Conference on Image, Vision and Computing (ICIVC) - A Method for Generating Spray Trajectory of a Shoe Sole Based on Laser Vision
摘要： A ?rst proof-of-concept mm-sized implantable device using ultrasonic power transfer and a hybrid bi-directional data communication link is presented. Ultrasonic power transfer enables miniaturization of the implant and operation deep inside the body, while still achieving safe and high power levels (100 W to a few mWs) required for most implant applications. The current implant prototype measures 4 mm 7.8 mm and is comprised of a piezoelectric receiver, an IC designed in 65 nm CMOS process and an off-chip antenna. The IC can support a maximum DC load of 100 W for an incident acoustic intensity that is 5% of the FDA diagnostic limit. This demonstrates the feasibility of providing further higher available DC power, potentially opening up new implant applications. The proposed hybrid bi-directional data link consists of ultrasonic downlink and RF uplink. Falling edge of the ultrasound input is detected as downlink data. The implant transmits an ultra-wideband (UWB) pulse sequence as uplink data, demonstrating capability of implementing an energy-ef?cient M-ary PPM transmitter in the future.
关键词： piezoelectric receivers,bi-directional data communication,mm-sized implants,CMOS,ultrasonic power transfer,active recti?er,IMD,antennas,radio transmitters,AC-DC converter,implantable biomedical devices
更新于2025-09-19 17:13:59
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[IEEE 2019 PhotonIcs & Electromagnetics Research Symposium - Spring (PIERS-Spring) - Rome, Italy (2019.6.17-2019.6.20)] 2019 PhotonIcs & Electromagnetics Research Symposium - Spring (PIERS-Spring) - PIERS2019 Organization
摘要： This paper demonstrates an innovative and simple solution for obstacle detection and collision avoidance of unmanned aerial vehicles (UAVs) optimized for and evaluated with quadrotors. The sensors exploited in this paper are low-cost ultrasonic and infrared range ?nders, which are much cheaper though noisier than more expensive sensors such as laser scanners. This needs to be taken into consideration for the design, implementation, and parametrization of the signal processing and control algorithm for such a system, which is the topic of this paper. For improved data fusion, inertial and optical ?ow sensors are used as a distance derivative for reference. As a result, a UAV is capable of distance controlled collision avoidance, which is more complex and powerful than comparable simple solutions. At the same time, the solution remains simple with a low computational burden. Thus, memory and time-consuming simultaneous localization and mapping is not required for collision avoidance.
关键词： quadrotor,quadrocopter,infrared,autonomous,ultrasonic,obstacle detection,Collision avoidance,UAV
更新于2025-09-19 17:13:59
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Hot-injection and ultrasonic irradiation syntheses of Cs2SnI6 quantum dot using Sn long-chain amino-complex
摘要： Lead (Pb) perovskites can be synthetically modified to form colloidal nanocrystals which exhibit remarkable optoelectronic properties in the various fields such as light-emitting devices, flexible electronics, and photodetectors. However, because of the toxicity issue of Pb, nanocrystals of Pb free such as tin (Sn)-based perovskites have got attention. In the present work, we have selected the Sn-based perovskite, Cs2SnI6, owing to the high air and thermal stability. Quantum dots of Cs2SnI6 were prepared by using two methods, namely the hot-injection method and the ultrasonic irradiation method. The difference between Cs2SnI6 particles generated by these two methods was discussed. The particles synthesized by using the hot-injection method were less than 10 nm in size and were aggregated structure due to particle tight-binding energy. On the other hand, the particles by using the ultrasonic irradiation method gave a mono-dispersed solution. The particle size was from several ten nanometers to several hundred nanometers.
关键词： Quantum dot,Cs2SnI6,Sn long-chain amino-complex,Hot-injection,Ultrasonic irradiation
更新于2025-09-19 17:13:59
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Interface Engineering by Employing Zeolitic Imidazolate Framework-8 (ZIF-8) as the only Scaffold in the Architecture of Perovskite Solar Cells
摘要： In this study, we employed Zeolitic Imidazolate Framework-8 (ZIF-8) at the interlayer between the compact TiO2 and perovskite layers. As a result, enhanced perovskite crystallinity and grain sizes, and considerably improved photovoltaic performance of perovskite solar cell (PSC) were achieved. It was demonstrated that the ZIF-8 film includes all characteristics suitable for being applied as scaffold in the PSCs with the advantage of easier synthesis approach in room temperature in comparison to the mesoporous TiO2 counterpart. Moreover, we replaced the thermal annealing process commonly applied on the perovskite layers with room temperature ultrasonic vibration post treatment of wet perovskite films.
关键词： zeolitic imidazolate framework,Perovskite solar cells,room temperature,ultrasonic vibration post treatment,grain size
更新于2025-09-19 17:13:59