High-intensity Ultrasonic Waves Research Articles

A comprehensive numerical procedure for high-intensity focused ultrasound ablation of breast tumour on an anatomically realistic breast phantom.

High-Intensity Focused Ultrasound (HIFU) as a promising and impactful modality for breast tumor ablation, entails the precise focalization of high-intensity ultrasonic waves onto the tumor site, culminating in the generation of extreme heat, thus ablation of malignant tissues. In this paper, a comprehensive three-dimensional (3D) Finite Element Method (FEM)-based numerical procedure is introduced, which provides exceptional capacity for simulating the intricate multiphysics phenomena associated with HIFU. Furthermore, the application of numerical procedures to an anatomically realistic breast phantom (ARBP) has not been explored before. The integrity of the present numerical procedure has been established through rigorous validation, incorporating comparative assessments with previous two-dimensional (2D) simulations and empirical data. For ARBP ablation, the administration of a 0.1 MPa pressure input pulse at a frequency of 1.5 MHz, sustained at the focal point for 10 seconds, manifests an ensuing temperature elevation to 80°C. It is noteworthy that, in contrast, the prior 2D simulation using a 2D phantom geometry reached just 72°C temperature under the identical treatment regimen, underscoring the insufficiency of 2D models, ascribed to their inherent limitations in spatially representing acoustic energy, which compromises their overall effectiveness. To underscore the versatility of this numerical platform, a simulation of a more clinically relevant HIFU therapy procedure has been conducted. This scenario involves the repositioning of the ultrasound focal point to three separate lesions, each spaced at 3 mm intervals, with ultrasound exposure durations of 6 seconds each and a 5-second interval for movement between focal points. This approach resulted in a more uniform high-temperature distribution at different areas of the tumour, leading to the ablation of almost all parts of the tumour, including its verges. In the end, the effects of different abnormal tissue shapes are investigated briefly as well. For solid mass tumors, 67.67% was successfully ablated with one lesion, while rim-enhancing tumors showed only 34.48% ablation and non-mass enhancement tumors exhibited 20.32% ablation, underscoring the need for multiple lesions and tailored treatment plans for more complex cases.

Impact of current density, TiO2 NPs, and ultrasonic waves on the physical and friction properties of Ni–Zn–TiO₂

In the present study, a nickel-zinc (Ni–Zn) alloy coating has been selected as the foundational coating, and the formation of a composite Ni–Zn-titanium dioxide (Ni–Zn–TiO2) coating, along with the factors influencing its development, has been thoroughly examined. The influential factors explored in this research encompass applying ultrasonic waves, current density, and incorporating varying concentrations of TiO2 nanoparticles (NPs). X-ray diffraction (XRD), Field emission scanning electron microscopy (FESEM), energy-dispersive X-ray (EDX) spectroscopy, and a wear test apparatus were utilized to assess the characteristics of these coatings. The findings indicate that the concentration of TiO₂ NPs in the plating bath profoundly impacts the morphology and coating properties. An increased TiO₂ concentration in the plating bath led to a finer morphology. Applying ultrasonic waves during the plating process enhanced the dispersion and finer distribution of NPs within the coating, resulting in improved wear resistance due to the confinement of irregularities. Applying ultrasonic waves up to 60 W improved the properties; however, a reduction in elemental levels was observed when the ultrasonic waves were increased to 120 W. This decrease in elemental levels can be attributed to the high-intensity ultrasonic waves, resulting in diminished wear resistance.

Optical fiber-based acoustic intensity microphone for high-intensity airborne ultrasound measurement

The increasing use of airborne ultrasonic waves in daily life, driven by advances in parametric and phased arrays, has led to innovative applications like highly directional speakers, non-contact tactile feedback, 3D acoustic levitation, and medical therapies. These advancements necessitate accurate measurement of high-intensity ultrasonic waves, exceeding the capability of traditional microphones limited to around 160 dB, and highlight the growing importance of measuring the sound field not merely as scalar (sound pressure) but as vector (acoustic intensity) to accommodate future technological developments. This paper introduces an acoustic intensity microphone using optical fibers as probes to overcome these limitations. The proposed method replaces the two ordinary microphones used in the traditional acoustic intensity measurement method with thin optical fibers, minimizing sound field disturbance. Experimental validation and the structure of a practical acoustic intensity microphone are discussed, building upon foundational work presented at USE2023 with added verification and insights.

Giant static refractive index gradient induced by strong ultrasonic wave

Spatiotemporal modulation of refractive index in an optical path medium allows for control of light propagation. This refractive index change (Δn) can be achieved by external stimulation such as temperature or density change, but there is a limit to the extent to which Δn can be controlled by external stimulation acting on a single medium. Here, we demonstrate a technique to form a giant refractive index gradient (Δn = 0.06) in a small region of water (< 10 mm) using a high-frequency, high-intensity (in the 100-megahertz-range, on the order of megapascals) ultrasonic wave. Ultrasonic radiation in water can statically modulate the refractive index in water from the initial value (n = 1.33) toward that of air.

Controlled etching of MXene for highly selective triethylamine detection at room temperature

MXene, exemplified by Ti3C2Tx, was obtained as a viable candidate for sensing gases at room temperature. However, in the current study, increased power consumption and poor process reproducibility resulted from the long cycle times to prepare MXene and MXene-based gas-sensitive materials. In this study, a six-sided high-intensity ultrasonic wave was applied to the etching environment, and a series of MAX-MXene heterostructures were effectively obtained in one step by adjusting the etchant content. Due to the unique structure of MXene flake and the generation of endogenous MAX-MXene heterostructure, the MAM gas sensor exhibits a response value of 4.1% to 10 ppm TEA at room temperature (23 °C) and relative humidity of 84%, providing fast response recovery time, low electric noise and excellent selectivity, with a comprehensive gas sensing performance superior to that of the pristine MXene materials reported before. This study provides new ideas for designing and applying new substrate materials based on MAX and MXene.

Two-dimensional MXene Ti3C2 for Efficient Photoacoustic Conversion

Two-dimensional MXene are potential photoacoustic conversion materials due to the excellent light absorption and photothermal conversion efficiencies. In this study, we theoretically analyze and experimentally demonstrate the photoacoustic properties of Ti3C2. High-intensity ultrasonic waves are generated by irradiating Ti3C2 films with 532 nm pulsed laser. By comparison, the signal amplitude of Ti3C2 is about twice as much as that of graphene. We validate the potential of Ti3C2 as an efficient functional material for photoacoustic or laser ultrasonic applications.

Performance enhancement of solution-processed amorphous WZTO TFT with HAO gate dielectric via power ultrasound technology

In this paper, power ultrasound technology (PUT) is employed to prepare the high-k hafnium-aluminum oxide (HAO) dielectric and thin film transistor (TFT). The continuous propagation of high-intensity ultrasonic waves in the metal oxide precursor solution can improve the dissolution efficiency of the solute and speed up the formation of the HAO precursor solution. The prepared HAO films have a smooth surface roughness of 0.36 nm and high optical transmittance of 85 %. Moreover, HAO films obtain excellent electrical properties with a relative permittivity of 15.9 and a leakage current density of 9.1 × 10−8 A/cm2 at 2 MV/cm as well. Finally, we successfully fabricate TFT with HAO dielectric using PUT, these TFTs exhibit switch characteristics with field effect mobility of 18.7 cm2v−1s−1, threshold voltage (Vth) of −0.47 V, and Vth shift of 0.35 V under positive gate bias stress. The results show that the PUT is a promising method that can remarkably decrease the preparation time of the precursor solution and improve the TFT performance.

Effect of laser-induced ultrasound treatment on material structure in laser surface treatment for selective laser melting applications

A new mechanism for controlling the microstructure of products in manufacturing processes based on selective laser melting is proposed. The mechanism relies on generation of high-intensity ultrasonic waves in the melt pool by complex intensity-modulated laser irradiation. The experimental study and numerical modeling suggest that this control mechanism is technically feasible and can be effectively integrated into the design of modern selective laser melting machines.

Nonlinear Behavior of High-Intensity Ultrasound Propagation in an Ideal Fluid

In this paper, nonlinearity associated with intense ultrasound is studied by using the one-dimensional motion of nonlinear shock wave in an ideal fluid. In nonlinear acoustics, the wave speed of different segments of a waveform is different, which causes distortion in the waveform and can result in the formation of a shock (discontinuity). Acoustic pressure of high-intensity waves causes particles in the ideal fluid to vibrate forward and backward, and this disturbance is of relatively large magnitude due to high-intensities, which leads to nonlinearity in the waveform. In this research, this vibration of fluid due to the intense ultrasonic wave is modeled as a fluid pushed by one complete cycle of piston. In a piston cycle, as it moves forward, it causes fluid particles to compress, which may lead to the formation of a shock (discontinuity). Then as the piston retracts, a forward-moving rarefaction, a smooth fan zone of continuously changing pressure, density, and velocity is generated. When the piston stops at the end of the cycle, another shock is sent forward into the medium. The variation in wave speed over the entire waveform is calculated by solving a Riemann problem. This study examined the interaction of shocks with a rarefaction. The flow field resulting from these interactions shows that the shock waves are attenuated to a Mach wave, and the pressure distribution within the flow field shows the initial wave is dissipated. The developed theory is applied to waves generated by 20 KHz, 500 KHz, and 2 MHz transducers with 50, 150, 500, and 1500 W power levels to explore the effect of frequency and power on the generation and decay of shock waves. This work enhances the understanding of the interactions of high-intensity ultrasonic waves with fluids.

Facile Sonochemical Preparation of Au-ZrO2 Nanocatalyst for the Catalytic Reduction of 4-Nitrophenol

High-intensity ultrasonic waves have great potential for the green synthesis of various nanomaterials under mild conditions and offer an excellent alternative for hazardous chemical methods. Herein a facile approach for the eco-friendly synthesis of Au-ZrO2 nanocatalyst with a high catalytic activity using a facile ultrasonic method is presented. Gold (Au) in the nanosize regime was successfully deposited on the surface of solvothermally synthesized monodispersed ZrO2 nanoparticles (ZrO2 NPs) in a very short period of time (5 min) at room temperature. Spherical shape small size Au nanoparticles that are uniformly dispersed on the surface of ZrO2 nanoparticles were obtained. Notably, in the absence of ZrO2 nanoparticles, HAuCl4 could not be reduced, indicating that nano-sized ZrO2 not only acted as support but also helped to reduce the gold precursor at the surface. The as-prepared Au-ZrO2 nanocatalyst was characterized by various techniques. The Au-ZrO2 nanocatalyst served as a highly efficient reducing catalyst for the reduction of 4-nitrophenol. The reaction time decreased with increasing the amount of catalyst.

Harmonic imaging of a defect in a flat plate using a guided wave generated by a high-intensity aerial ultrasonic wave

We propose the visualization of defects by means of guided waves generated simultaneously at multiple frequencies using the nonlinearity of a high-intensity ultrasonic wave. This report presents the use of the proposed method to visualize a slit in a thin metal plate. The results confirm that even though the multiple-frequency guided waves infiltrate the defect area in different directions, the defect can be visualized by imaging the wave propagation.

Ultrasonically-assisted surface modified TiO2/rGO/CeO2 heterojunction photocatalysts for conversion of CO2 to methanol and ethanol.

Converting CO2 to usable fuel may contribute to lowering of global warming, thus this study developed effective heterojunction photocatalysts for the photoreduction of CO2 with water into methanol and ethanol fuels. The photocatalysts were prepared from combining surface modified titanium dioxide (TiO2) nanoparticles with reduced graphene oxide (rGO) and cerium oxide (CeO2). The TiO2 surfaces were firstly modified via the sono-assisted exfoliation, with high intensity ultrasonic waves (ultrasonic horn, 20 kHz, 150 W/cm2) in 10 M NaOH for 1 h. Highly reactive nanosheets delaminated from outer surfaces of the primary TiO2 crystals leading to an increase in specific surface active area, light absorption and decrease in electron-hole recombination rate, which enhanced photocatalytic activity. Then, 0.75 wt% rGO and 1 wt% CeO2 were incorporated into the surface modified TiO2 to promote photogenerated charge separation, electron mobility and CO2 absorptivity. The modified TiO2/rGO/CeO2 photocatalysts exhibited superior photocatalytic performance by producing methanol at 641 μmol/gcath and ethanol at 271 μmol/gcath, almost 7 times higher than rates from pure TiO2. The significant improvement in CO2 photoconversion activity was mainly attributed to the high interfacial contact area and strong connection between the reactive delaminated TiO2 nanosheets, rGO and CeO2, which, in turn, facilitated the flow of large number of photogenerated charge carriers to react with the absorbed species, and the multi-step charge transportation due to the heterojunction effect that effectively retarded electron-hole recombination.

Hydrogen Sulfide Adsorption improvement of Bayah Natural Zeolite

Hydrogen sulfide adsorption performance of sonicated natural zeolite in the Ferric chloride hexahydrate solution has been studied. In this research natural zeolite exposed with high intensity ultrasonic waves for 40 minutes, 80 minutes and 120 minutes. Qualitative analysis and characterization of modified zeolite carry out with X-ray diffraction, Infrared spectroscopy, BET adsorption desorption, LAS particle size analysis and scanning electron microscopy prior and after H2S adsorption. Natural zeolite phase are clipnotilolite and mordenite phase with 0.99%wt and 0.512 x 10-3 %wt respectively. By adding 5gr FeCl3.6H2O and ultrasonic exposure, zeolite chemical and physical properties such as chemical composition, particle size, surface area and pore radius are improved. Hydrogen sulfide %wt adsorption effectiveness showing that modified zeolite higher 70-117% comparing with unmodified zeolite.

Effect of ultrasonic processing on the d-spacing of natural zeolite

The crystal geometry characteristics of sonicated Bayah natural zeolite using X-Ray diffraction (XRD) method has been studied. High intensity ultrasonic waves were exposed to the samples for 40 minutes, 80 minutes and 120 minutes. Rietveld analysis of X-Ray diffraction was conducted to evaluate effect of ultrasonic processing to the shifting of d-spacing each sample. Higher shifting d-spacing 0.01 up to 0.03 Å found at ZA40 sample and lowest shifting found at ZA80 sample 0.003 up to 0.007 Å. Relationship between sonification process with shifting of d-spacing are close relationship with duration of applied high intensity ultrasonic process resulted in crystallite morphology due to changes of O-H binding.

Characterization of sonicated natural zeolite/ferric chloride hexahydrate by infrared spectroscopy

The characteristics of sonicated Bayah natural zeolite with and without ferric chloride hexahydrate solution using infrared method has been studied. High intensity ultrasonic waves were exposed to the samples for 40 min, 80 min and 120 min. Infra red spectra analysis was conducted to evaluate zeolite vibrational spectrum contributions, namely, the vibrations from the framework of the zeolite, from the charge-balancing cations, and from the relatively isolated groups, such as the surface OH groups and their behavior after sonication process. An addition of FeCl3.6H2O and sonication process on natural zeolite improved secondary building units link by forming oxygen bridges and also close relationship with duration of applied high intensity ultrasonic process. Longer ultrasonic process resulted in more increment of O-H absorbance.

Surface modification of TiO2 particles with the sono-assisted exfoliation method

This study reported a novel approach to optimize the photocatalytic property of anatase TiO2 particles by delaminating their outer surface into highly reactive nanosheets via the sono-assisted exfoliation method. To modify the surface, TiO2 particles were dispersed in aqueous solution of 10M sodium hydroxide (NaOH) and tetrabutylammonium hydroxide (TBAOH), followed by irradiation with high intensity ultrasonic wave (20kHz, 150W/cm2) for 60min. The intercalation and exfoliation processes were accelerated with the driving force of the extreme acoustic cavitation leading to the delamination of TiO2 nanosheets with highly reactive exposed {001} facets from the mother TiO2 crystals. The presence of TBAOH increased yield of nanosheets formation and stabilized the nanosheet structure. The unique morphology of the surface modified TiO2 particles provided benefits in increasing the specific surface area and lowering the optical band gap energy (Eg) and electron-hole recombination rate resulting in an enhancement of methylene blue dye degradation efficiency. The surface modification of TiO2 particles by the sono-assisted exfoliation method can optimize the photocatalytic activity by yielding synergetic effects of the high surface reactive sites of the nanosheets and the high degree of crystallinity of the bulk structure.

A non-contact detection of the internal defect in solid material by aerial ultrasonic beam

Measurement method using aerial sound waves and an optical equipment is utilized in a non-contact and non-destructive testing. Technique that we have been conventionally proposed, uses high-intensity aerial ultrasonic waves (20kHz). Specifically, a surface of an object is vibrated by high-intensity ultrasonic waves with a point focus. A vibration generated on the surface of the object is measured by laser Doppler vibration galvanometer. In general, the vibration of defect area is larger than that of defect-free area when the sound waves were irradiated to the object. Therefore, by performing the measurement over a target area, it is possible to image the defect area from the vibration distribution. However, this method needs a long time to measure the object with the defect. Therefore, we adopted a method of irradiating high-intensity ultrasonic to a wide range on the surface of the object using an aerial ultrasonic waves focused into a beam. In this report, we describe the details of the experimental results to detect defects in the object by using this technique.

Effects of ultrasonication and conventional mechanical homogenization processes on the structures and dielectric properties of BaTiO3 ceramics

The effects of the homogenization process on the structures and dielectric properties of pure and Nb-doped BaTiO3 ceramics have been investigated using an ultrasonic homogenization and conventional mechanical methods. The reagents were homogenized using an ultrasonic processor with high-intensity ultrasonic waves and using a compact mixer-shaker. The components and crystal types of the powders were determined by Fourier-transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) analyses. The complex permittivity (ε′, ε″) and AC conductivity (σ′) of the samples were analyzed in a wide frequency range of 20Hz to 2MHz at room temperature. The structures and dielectric properties of pure and Nb-doped BaTiO3 ceramics strongly depend on the homogenization process in a solid-state reaction method. Using an ultrasonic processor with high-intensity ultrasonic waves based on acoustic cavitation phenomena can make a significant improvement in producing high-purity BaTiO3 ceramics without carbonate impurities with a small dielectric loss.

Post in-situ reaction ultrasonic treatment for generation of Al–4.4Cu/TiB2 nanocomposite: A route to enhance the strength of metal matrix nanocomposites

The present study reports the fabrication of Al–4.4Cu/2TiB2 nanocomposite from its microcomposite via post in-situ reaction ultrasonic treatment (UT). For the purpose of accomplishing post in-situ reaction ultrasonic treatment, the in-situ formed Al–4.4Cu/2TiB2 microcomposite was remelted and subjected to high-intensity ultrasonic waves for various length of time. Post in-situ reaction ultrasonic treatment of Al–4.4Cu/2TiB2 composite has resulted significant reduction in the size of TiB2 particles down to nano range. Ultrasonic cavitation aided particle dissolution and re-precipitation has been proposed as a mechanism responsible for the substantial reduction of TiB2 particle size. The compressive yield strength of Al–4.4Cu/2TiB2 nanocomposite formed via formed post in-situ reaction ultrasonic treatment is approximately two times higher than that of Al–4.4Cu alloy. The improved mechanical property of nanocomposite has been attributed to the presence of TiB2 particles of nanometer size and robust interfaces with the aluminum alloy.

Development of nano-colloidal system for fullerene by ultrasonic-assisted emulsification techniques based on artificial neural network

Propagation of high intensity ultrasonic waves and shearing effect in formulating nanoemulsion loaded fullerene for drug delivery was investigated. Artificial neural network (ANN) was applied to optimize the emulsification process by varying the ultrasonic and homogenization parameters. Control of operating conditions, such as sonication amplitude (30–70%) and duration (60–120s), as well as homogenization rate (4000–5000rpm), was tested to determine the physical attributes of nanoemulsion. Ultrasonic cavitation showed far greater effects as compared to high shear homogenization in controlling the droplet size (sonication time) and viscosity (sonication amplitude) of the nanoemulsion system. Levenberg–Marquardt algorithm produced the optimum topology with network architecture of three inputs, four hidden nodes, and two outputs. Validation further confirmed the aptness of the proposed model with low root mean square error. In this study, ANN has superior predictive ability by yielding low percentage of residual standard error. An ultrasonic approach in formulating fullerene nanoemulsion system is a powerful technique in minimization of droplet size and acquisition of desirable viscosity. This serves as a platform to advance fullerene in nanomedicine field despite its hydrophobicity.