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Laser stripping technology is an advanced processing method with high efficiency and low material loss, which can greatly reduce material loss in the production process of single-crystal SiC wafer, but the single-crystal SiC ingot still have a certain bonding force after laser modification. Ultrasonic vibration can reduce the bonding force and thus strip single-crystal SiC wafer. In order to investigate the effect of ultrasonic vibration on the reduction of the bonding force of single-crystal SiC internal modification layer, through the ultrasonic-assisted stripping of single-crystal SiC orthogonal experiment, the ultrasonic vibration parameters of ultrasonic frequency, vibration time and ultrasonic power of the three indexes of the reduction of the bonding force was analyzed. The results show that the bonding force of the modified layer decreased by 25 %–60 % after ultrasonic vibration. Variance analysis of the experiment results showed that the main factors influencing the bond strength reduction were vibration time and ultrasonic power in turn. When the vibration time is longer and the ultrasonic power is higher, the stripping force decreases more, and the stripping force of single-crystal SiC wafers decreases up to 60 % under the condition of vibration time of 5min and ultrasonic power of 700 W. Through analysis of the single-crystal SiC cross-section, distinct cleavage steps and cleavage channels are evident. The laser-modified region exhibits defect such as nano-pores, micro-cracks, and nano-particles. After the single-crystal SiC laser modification process was upgraded, the distance between the ultrasonic tool head and the single-crystal SiC was 1.5 mm can directly strip off the single-crystal SiC wafer. And eventually stripped 6-inch single-crystal sic wafers. Therefore, ultrasonic vibration can increase the internal defects in the single-crystal SiC modified layer, causing crack expansion to occur and ultimately stripping the single-crystal SiC wafer. [ABSTRACT FROM AUTHOR]

Diamond wire sawing plays an important role in semiconductor processing. Considering that the cavitation effect can improve the machining quality, a new technology of ultrasonic cavitation–assisted diamond wire sawing (UCAWS) is proposed in this paper. To study the formation process of cavitation in UCAWS and its influence on processing, a simulation and experimental study of cavitation in UCAWS is conducted. The pressure distribution model and cavitation model of two-phase mixed flow around wire sawing in UCAWS are constructed by combining the ideal bubble dynamic theory. The effect of vapor volume fraction (VVF) on cavitation intensity is calculated using computational fluid dynamics (CFD). The simulation results show that transient cavitation and steady-state cavitation exist simultaneously around wire sawing and with the increase of ultrasonic amplitude, the cavitation effect is enhanced. UCAWS experiments are conducted on monocrystalline silicon to study the changes in sawing force and workpiece surface roughness. The experimental results show that the sawing force of the UCAWS decreases by 6.65% on average compared to ultrasonic vibration–assisted diamond wire sawing (UAWS), the surface roughness value is reduced by 6.3% on average, and the surface morphology is improved. Therefore, UCAWS processing technology can be applied in manufacturing to improve the surface quality of the workpiece further. [ABSTRACT FROM AUTHOR]

Ultrasonic waves have been explored for fracturing coal seams to enhance Coalbed Methane (CBM) permeability, yet the underlying mechanics of ultrasonic cavitation are not fully understood. This study investigates the effect of water-based ultrasonic cavitation on coal pores microstructure by employing fluid invasion methods and non-destructive X-ray testing to reconstruct coal pore microstructures. Additionally, numerical simulations of ultrasonic cavitation development were conducted. The research examines how ultrasonic power influence evolution mechanism of cavitation effects in pores microstructure of water-bearing coal. Such insights lay a theoretical groundwork for improved Water-Based Ultrasonic Cavitation Enhanced Coalbed Methane Recovery (WUC-ECBM). Findings suggest that coal pores microstructure with a fully connected pore topology are more conducive to ultrasonic cavitation. As ultrasonic exposure increases, the accumulated waves cause coal pore microstructure cavitation bubbles to oscillate violently and non-linearly, leading to their growth, development, and collapse. This results in high-energy microjets and shockwaves, creating a high-temperature, high-pressure environment (reaching up to 35.69 MPa and 2729.77 K) favorable for improving gas desorption and migration. Ultrasonic power adjusts the cavitation threshold and intensity, facilitating gas migration. This research aims to improve gas desorption and migration in coal by capitalizing on the mechanical, physical, and thermal effects of ultrasonic cavitation. These findings offer theoretical support for the effective implementation of WUC-ECBM. [ABSTRACT FROM AUTHOR]

[Display omitted] • An method of high-density ultrasound for enhanced mass transfer in liquid-liquid interfacial reaction was proposed. • The mass transfer coefficient in liquid-liquid interfacial reaction systems was enhanced by 252 %. • Iron doping rate of prepared Fe-CDs reached 20.9 %. • Photocatalytic oxidation efficiency of prepared Fe-CDs on 1,4-DHP reached 98.2 %. • Ultrasonically regulated particle size, size distribution and fluorescence of prepared Fe-CDs. The precise and controllable preparation of carbon nanomaterials under mild conditions poses a great challenge, especially for metal-catalysed multiphase preparation. This work proposes an efficient method that utilizing high-density ultrasound to enhance the liquid-liquid interfacial reaction system. Iron-doped carbon dots (Fe-CDs) are successfully synthesized in such a normal temperature and atmospheric-pressure reaction condition. It is shown that transient cavitation provides a high-temperature and high-pressure microenvironment for the preparation of Fe-CDs. Moreover, the size of the reactant droplets is reduced from 200.0 ± 17.3 μm to 8.1 ± 2.9 μm owing to the acoustic flow and cavitation effects, which increases the specific surface area of the two reacting phases and improves the mass transfer coefficient by more than 252.0 %. As a result, the yield increases by more than an order of magnitude (from 0.7 ± 0.1 % to 11.9 ± 0.2 %) and the Fe doping rate reaches 20.9 %. The photocatalytic oxidation conversion of 1,4-Dihydropyridine (1,4-DHP) using the obtained Fe-CDs is as high as 98.2 %. This research gives a new approach for the efficient and safe production of Fe-CDs, which is promising for industrial applications. [ABSTRACT FROM AUTHOR]

Background: Various physical phenomena come into use in medicine; however, to date, universal physical methods have not been developed to optimize the course of the wound healing at all treatment stages. In combustiology, the first stage of burn treatment is debridement; then it is important to create an optimal biological environment, normalize blood circulation, suppress pathogenic flora, and stimulate proliferative processes in the wound.Objective: To determine the effectiveness of low-temperature argon plasma (LTAP) and ultrasonic cavitation in deep burn wound treatment based on clinical observations and cytological findings.Materials and methods: We studied impression smears from burn wounds of 36 patients with deep burns of various etiologies who were treated using LTAP and ultrasonic cavitation in the Thermal Injuries Unit at the Saint Petersburg I.I. Dzhanelidze Research Institute of Emergency Medicine (Saint Petersburg, Russian Federation) between 2022 and 2023.Results: We found that cytogram findings in the study area changed from the inflammatory type to the regenerative-inflammatory one on day 3-7 when LTAP and ultrasonic cavitation were used, while such change in the control area was observed only after 10 days of treatment. Thanks to the use of LTAP and ultrasound after necrosectomy for deep dermal burns, the wound preparation for autologous skin grafting takes less time than it does with standard methods of local burn wound care. Ultrasonic cavitation should be used in cases of severe exudation and slough, whereas LTAP should be used when reparative processes in a burn wound slow down.Conclusions: Burn wound treatment using ultrasonic cavitation and LTAP enables to prepare the wound surface for autologous skin grafting with a high engraftment rate. The procedure allows to effectively and atraumatically debride the wound and suppress pathogenic microflora. Further research is planned in patients with large deep burn wounds.

Abstract In the field of power ultrasonic vibration processing, the thin liquid layer nestled between the tool head and the material serves as a hotbed for cavitation shock wave emissions that significantly affect the material's surface. The precise manipulation of these emissions presents a formidable challenge, stemming from a historical deficit in the quantitative analysis of both the ultrasonic enhancement effect and the shock wave intensity within this niche environment. Our study addresses this gap by innovatively modifying the Gilmore-Akulichev equation, laying the groundwork for a sophisticated bubble dynamics model and a pioneering shock wave propagation model tailored to the thin liquid layer domain. Firstly, our study investigated the ultrasound enhancement effect under various parameters of thin liquid layers, revealing an amplification of ultrasound pressure in the thin liquid layer area by up to 7.47 times. The mathematical model was solved using the sixth-order Runge–Kutta method to examine shock wave velocity and pressure under different conditions. our study identified that geometric parameters of the tool head, thin liquid layer thickness, ultrasonic frequency, and initial bubble radius all significantly influenced shock wave emission. At an ultrasonic frequency of 60 kHz, the shock wave pressure at the measurement point exhibited a brief decrease from 182.6 to 179.5 MPa during an increase. Furthermore, rapid attenuation of the shock wave was found within the range of R 0-3R 0 from the bubble wall. This research model aims to enhance power ultrasonic vibration processing technology, and provide theoretical support for applications in related fields.

Explosion welding is an unconventional method of joining two dissimilar metal materials, mostly used to clad dissimilar materials or when some unusual geometries need to be joined. Some of the bimetal joints obtained this way have applications in special cutting tools, transition joints, propellers and turbine blades, and therefore it is important to know the wear resistance of welded joints. In this research, explosive Demex, based on ammonium nitrate and trinitrotoluene, was used to weld plates of aluminium alloy AW-2024 and steel 1.0216. The welding procedure was carried out in the configuration of parallel plates. The quality of the welded joint was inspected on samples cut out from the welded plate by the method of microscopic analysis on the cross-section and by an ultrasonic cavitation test. Materials erosion in the zone of the welded joint after each of 4 cavitation cycles was observed using an optical microscope and by monitoring the mass loss. The wear resistance of the created bimetal was analysed from the aspects of further exploitation.

With the increasing demand for deep oil and gas exploration and CCUS (Carbon Capture, Utilization, and Storage) engineering, improving rock-crushing efficiency stands as a pivotal technology. Ultrasonic vibration-assisted drilling has emerged as a novel rock-breaking technology. The high-frequency vibrations of ultrasonic waves impact rocks, inducing resonance and accelerating their fragmentation. At the same time, ultrasonic waves generate cavitation bubbles in the liquid near rock surfaces; the expansion and collapse of these bubbles further contribute to rock damage, thereby improving crushing efficiency. Therefore, investigating the dynamics and failure characteristics of cavitation bubbles near rock surfaces under ultrasonic influence is crucial for advancing ultrasonic-assisted rock-breaking technology. This study treats the liquid as compressible flow and investigates the movement and rupture of bubbles near rock surfaces under varying ultrasonic parameters, rock properties, characteristics of the circulating medium, and other relevant factors. The findings show that ultrasonic waves induce the oscillation, translation, collapse, and rebound of bubbles near rock surfaces. Higher ultrasonic frequencies correspond to larger collapse pressures and amplitudes near surrounding rocks, as well as longer expansion times and shorter collapse durations. In addition, bubble movement and collapse lead to rock material deformation, influenced by the rheological properties of the liquid medium. The study outcomes serve as a foundation for optimizing engineering parameters in ultrasonic-assisted rock breaking and provide theoretical support for the advancement of this technology. [ABSTRACT FROM AUTHOR]

Coalbed methane (CBM), recognized as a sustainable and environmentally friendly energy source, plays a crucial role in mitigating global climate change and advancing low-carbon energy solutions. However, the prevalence of low-permeability coal seams poses a significant challenge to effective CBM extraction. Improving coal permeability has emerged as a viable strategy to address the issue of low-permeability coal. Conventional CBM stimulation methods fall short in overcoming this obstacle. In contrast, the enhanced technique of CBM extraction by water-based ultrasonic cavitation holds great promise due to its use of high energy intensity, safety, and efficiency. Nevertheless, the inadequate theoretical framework for managing this technology impedes its widespread adoption for large-scale applications. This study investigated the impact of water-based ultrasonic cavitation treatment on coal's properties and permeability through mechanical testing and permeability measurements conducted before and after treatment. This study also explored the process by which this technology, known as WUC-ECBM, improves coal's mechanical properties and permeability. The findings suggest a potential stimulation technique (WUC-ECBM) for use in CBM extraction, and its physical mechanism. [ABSTRACT FROM AUTHOR]

Copyright of Experimental Technology & Management is the property of Experimental Technology & Management Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In the field of power ultrasonic vibration processing, the thin liquid layer nestled between the tool head and the material serves as a hotbed for cavitation shock wave emissions that significantly affect the material's surface. The precise manipulation of these emissions presents a formidable challenge, stemming from a historical deficit in the quantitative analysis of both the ultrasonic enhancement effect and the shock wave intensity within this niche environment. Our study addresses this gap by innovatively modifying the Gilmore-Akulichev equation, laying the groundwork for a sophisticated bubble dynamics model and a pioneering shock wave propagation model tailored to the thin liquid layer domain. Firstly, our study investigated the ultrasound enhancement effect under various parameters of thin liquid layers, revealing an amplification of ultrasound pressure in the thin liquid layer area by up to 7.47 times. The mathematical model was solved using the sixth-order Runge–Kutta method to examine shock wave velocity and pressure under different conditions. our study identified that geometric parameters of the tool head, thin liquid layer thickness, ultrasonic frequency, and initial bubble radius all significantly influenced shock wave emission. At an ultrasonic frequency of 60 kHz, the shock wave pressure at the measurement point exhibited a brief decrease from 182.6 to 179.5 MPa during an increase. Furthermore, rapid attenuation of the shock wave was found within the range of R0-3R0 from the bubble wall. This research model aims to enhance power ultrasonic vibration processing technology, and provide theoretical support for applications in related fields. [ABSTRACT FROM AUTHOR]

Rational modulation of surface reconstruction in the oxygen evolution reaction (OER) utilizing defect engineering to form efficient catalytic activity centers is a topical interest in the field of catalysis. The introduction of point defects has been demonstrated to be an effective strategy to regulate the electronic configuration of electrocatalysts, but the influence of more complex planar defects (e.g., twins and stacking faults), on their intrinsic activity is still not fully understood. This study harnesses ultrasonic cavitation for rapid and controlled introduction of different types of defects in the FeCoNi/FeAl2O4 hybrid coating, optimizing OER catalytic activity. Theoretical calculations and experiments demonstrate that the different defects optimize the coordination environment and facilitate the activation of surface reconstruction into true catalytic activity centers at lower potentials. Moreover, it demonstrates exceptional durability, maintaining stable oxygen production at a high current density of 300 mA cm−2 for over 120 hours. This work not only presents a novel pathway for designing advanced electrocatalysts but also deepens our understanding of defect‐engineered catalytic mechanisms, showcasing the potential for rapid and efficient enhancement of electrocatalytic performance. [ABSTRACT FROM AUTHOR]

Copyright of Experimental Technology & Management is the property of Experimental Technology & Management Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In the present study, the effect of ultrasonic cavitation on CuZnAl alloy was investigated. A corresponding experimental work was conducted based on an ultrasonic cavitation experimental rig. The microstructure and deformation of CuZnAl alloy were observed and analyzed at different exposure times. The results show that after ultrasonic cavitation treatment, the coarse long-strip grain structure of CuZnAl alloy was gradually refined into equiaxed grains, and the average grain size was reduced from 263.0 to 49.7 μm. However, with long exposure to ultrasonic cavitation, grain boundaries crack and shed from the base, which causes attenuation of the grain refining effect, and the microhardness of the sample declines significantly. Furthermore, in different stages of deformation induced by ultrasonic cavitation, major deformation mechanisms were different. In the early deformation stage, the dislocation slip mechanism was dominant. In the later deformation stage, twinning deformation acted as another important mechanism. [ABSTRACT FROM AUTHOR]

Surface-attached micro- and nanobubbles are known for their resistance to external forces. This study experimentally and theoretically investigates their response to strong ultrasonic fields. Surface-attached micro- and nanobubbles with contact radii from 2 μm to 20 μm are generated in a microchannel and exposed to ultrasound through a vibrating glass substrate. At a driving frequency over 200 kHz up to 2 MHz tested, no significant response from the micro- and nanobubbles is observed. By contrast, at 100 kHz–200 kHz, ultrasonic cavitation bubbles appear in the microchannel and migrate toward the surface micro- and nanobubbles. Then the surface micro- and nanobubbles merge with the ultrasonic cavitation bubbles, detach from the substrate, and become free gaseous nuclei susceptible to further cavitation. Notably, the removal process leaves no observable residue. Theoretical analysis suggests that the directional migration of cavitation bubbles is driven by mutual acoustic radiation forces. This work demonstrates that ultrasonic fields can effectively remove surface micro- and nanobubbles, transforming them into free gaseous cavitation nuclei.

Background: The history of gunshot wound treatment dates back several centuries. However, every new war or protracted armed conflict makes surgeons return to this issue. In recent years the nature of wounds changed: injuries become more severe, with a larger amount of damaged tissue. Among the wounded persons, blast and fragment injuries prevail over gunshot injuries. Gunshot wounds, as a rule, differ from wounds inflicted by old-style weapons in the scale, depth, and severity of anatomical destruction of soft tissue and bones. Modern physical methods of wound management and preparation of wounds for plastic closure, such as low-frequency ultrasound, enable to debride the wound surface with minimal damage to viable tissues and perform plastic closure of soft tissue defects as radically and as early as could be.Objective: To improve methods of primary surgical debridement in patients with combat surgical trauma using low-frequency ultrasound.Materials and methods: We studied treatment results in 176 wounded and injured people hospitalized in the burn unit and the division of plastic surgery and cell transplantation at the V.K. Gusak Institute of Emergency and Reconstructive Surgery (Donetsk, Russian Federation) between 2015 and 2023. All the patients were divided into 2 groups. Group 1 (main) included 86 patients who underwent surgical wound debridement with ultrasonic cavitation. Group 2 consisted of 90 patients who were operated on without ultrasonic wound debridement. The groups of patients were comparable.Results: After surgical wound debridement, segmented neutrophils (78%-68%) were the main type of blood cells. After ultrasonic wound debridement, the amount of detritus decreased by 3.75 times. In the main group, the number of fibroblasts was 1.88 times higher than that in the comparison group. On day 4, the specific area of the granulation tissue was 1.7 times higher in the main group compared with that in the comparison group. Results of the morphometric control revealed that on day 4 the number of capillaries in the granulation tissue was 31.3 ± 2.5 units in the main group and 20.0 ± 1.12 units in the comparison group. Ultrasonic cavitation of wounds helps suppress wound infection by day 4-5 of treatment: in 82.2 ± 5.7% of the patients, the number of microorganisms per gram of tissue decreased below the “critical number”, whereas in the comparison group it was achieved in 28.9 ± 6.7% of the patients. According to laser Doppler flowmetry findings, we obtained a statistically significant increase in the mean blood flow value (M index) by 1.22 times 24-48 hours after surgical treatment. In the main group, 11.6 ± 3.4% of complications were reported, whereas in the comparison group it was 24.5 ± 4.4%, P < .05. The mean number of operations per person was 1.6 ± 0.4 in the main group and 2.8 ± 0.5 in the comparison group, P < .05. The mean duration of inpatient treatment was 13.5 ± 3.4 days in the main group and 24.3 ± 2.5 days in the comparison group, P < .01.Conclusions: We can conclude that ultrasonic cavitation is advantageous in routine surgical debridement of gunshot wounds followed by primary or delayed primary closure.

Coal gasification fine slag (CGFS) has high utilization value, but the low recovery rate of residue carbon greatly restricts its resource utilization. The oil agglomeration separation method has obvious advantages in the CGFS separation process, but its separation efficiency is severely limited by the symbiotic structure of carbon and ash. In order to break through the bottleneck problem of residue carbon separation and enrichment technology by oil agglomeration method, the effects of ultrasonic time, ultrasonic power, fluid shear time and their interaction on oil agglomeration and separation were investigated in this paper. Combined with BET, particle size distribution, FT-IR, XPS and SEM-EDS analysis methods, the strengthening mechanism of ultrasonic cavitation and fluid shear (UC-FS) pretreatment on oil agglomeration separation was revealed. The results show that when the ultrasonic power is 270 W, the ultrasonic treatment time is 29 min, and the fluid shear time is 23 min, the concentrate with ash content of 9.55% and the tailings with ash content of 91.51% can be obtained, and the combustible recovery rate can be increased to 90.54%. Ultrasonic cavitation gradually loosens the original dense carbon ash structure, and promotes the development of the pore structure of CGFS in coordination with the scouring effect of fluid shear, which increases the dissociation degree of carbon ash particles and thus reduces the ash content of concentrate. UC-FS pretreatment can effectively increase the proportion of hydrophobic groups such as C—C, C=C and C—H on the surface of carbon residue, increase its contact angle from 110.34° to 121.16°, and further expand the difference of hydrophilic and hydrophobic properties on the surface of carbon and ash particles, thus improving the effect of oil agglomeration separation. The mechanism of UC-FS synergistic pretreatment to improve the efficient separation of carbon ash particles is mainly attributed to the micro-abrasive effect generated by the coupling of ultrasonic cavitation bubbles and fine-grained microspheres. This study can provide theoretical basis and technical guidance for the separation and utilization of CGFS.

The ceramic particle reinforced Aluminium Matrix Composites (AMCs) lead to a reduction in ductility due to the restricted plastic flow of the matrix. The present work shows an enhancement in tensile properties without considerable loss in ductility by introducing MgAl2O4 (∼100 nm) nanoparticles into Al–2Mg–1Si via ultrasonic cavitation treatment (UCT). The microstructural analysis was carried out using polarized light microscope, SEM/EDS and TEM. MgAl2O4 nanoparticles were distributed uniformly in Al–2Mg–1Si matrix by UCT. The addition of MgAl2O4 nanoparticles significantly refined the grain size and enhanced the tensile strength while retaining the ductility of the nanocomposite. Fractography examination of the tensile tested samples revealed a ductile fracture for Al–2Mg–1Si matrix alloy and a brittle fracture for MgAl2O4 reinforced composites. This difference in fracture behavior is attributed to the cleavage texture present on the fractured surfaces of MgAl2O4 nanocomposites. The wear resistance is significantly increased by adding in-situ MgAl2O4 nanocomposites. Plastic delamination and adhesive wear are the main mechanisms, according to analysis of the worn surface.

High-intensity focused ultrasound (HIFU) is considered as an important non-invasive way for tumor ablation in deep organs. However, accurate real-time monitoring of the temperature field within HIFU focal area remains a challenge. Although ultrasound technology, compared with other approaches, is a good choice for noninvasive and real-time monitoring on the temperature distribution, traditional ultrasonic thermometry mainly relies on the backscattered signal, which is difficult for high temperature (>50 °C) measurement. Given that artificial intelligence (AI) shows significant potential for biomedical applications, we propose an AI-powered ultrasonic thermometry using an end-to-end deep neural network termed Breath-guided Multimodal Teacher-Student (BMTS), which possesses the capability to elucidate the interaction between HIFU and complex heterogeneous biological media. It has been demonstrated experimentally that two-dimension temperature distribution within HIFU focal area in deep organ can be accurately reconstructed with an average error and a frame speed of 0.8 °C and 0.37 s, respectively. Most importantly, the maximum measurable temperature for ultrasonic technology has been successfully expanded to a record value of 67 °C. This breakthrough indicates that the development of AI-powered ultrasonic thermometry is beneficial for precise HIFU therapy planning in the future.

The article addresses the material science solutions on the sources and mechanisms of operational and technological destruction in the main units of high-power liquid rocket engines and structural and technological solutions developed to prevent them. [ABSTRACT FROM AUTHOR]

Stir-casting with ultrasonic cavitation produced nano-Al2O3-filled AA7150 matrix composites in this study. The SEM microstructure study shows that all composites include nano-Al2O3 particles with consistent particle sizes and homogenous distribution. EDS and XRD showed no secondary phases or impurities in the composite. Optical microscopy showed intense ultrasonic cavitation effects, and nano-Al2O3 particles caused grain refinement in the AA7150 matrix. The composite's mechanical characteristics improved when the Al2O3 nanoparticle weight percentage (wt.%) increased. With only 2.0 wt.% nano-Al2O3 particles, the composites yielded 232 MPa, 97.52% higher than the sonicated AA7150 matrix alloy. Multiple models were used to characterize the strength of the AA7150 nano-Al2O3 composite. The findings showed that thermal incongruity, Orowan strengthening, the Hall–Petch mechanism, and load transfer effects contributed the most towards the increased strength of the composite. Increasing the nano-Al2O3 wt.% in the AA7150 matrix improved hardness by 95.08%, yield strength by 90.34%, and sliding wear resistance by 46.52%. This enhancement may be attributed to the combined effects of better grain refinement, enhanced dispersion with dislocation strengthening, and better load transfer between the matrix and reinforcement, which are assisted by the inclusion of reinforcements. This result was confirmed by optical studies. [ABSTRACT FROM AUTHOR]

Biofouling on ships and offshore structures has always been a difficult problem to solve, which not only jeopardizes the structural strength but also brings great economic losses. Ultrasonic cavitation is expected to solve this problem due to its characteristics of no damage to structures and no pollution. Starting from the phenomenon and mechanism of ultrasonic cleaning, this paper introduces the application of ultrasonic cavitation in ship, pipeline and oil cleaning as well as ballast water treatment. By reviewing the existing studies, limitations such as insufficient ultrasonic parameter studies, lack of uniform cleanliness standards, and insufficient cavitation studies are summarized to provide traceable research ideas for improving ultrasonic cavitation technology and to guide the expansion and improvement of its applications. [ABSTRACT FROM AUTHOR]

SBS (styrene–butadiene–styrene block copolymer) is currently the most widely used asphalt modifier, and SBS modified asphalt is usually prepared by high-speed shearing. This paper combines the cavitation effect of ultrasonic to assist in the preparation of SBS modified asphalt, and conducts numerical simulation and rheological properties research on the cavitation bubbles in the molten SBS modified asphalt fluid. The cavitation bubbles in the modified asphalt fluid will expand and contract as the pressure changes inside and outside the bubbles. When the cavitation bubble is compressed to the minimum and the pressure inside the bubble reaches 1.94 × 105Pa, the direction of the velocity vector near the cavitation bubble will change with the expansion and compression of the bubble. The expansion–contraction process of a single cavitation bubble can release 6.41 × 10-7J of energy, thus breaking the long bonds in asphalt and generating a large number of free radicals react with the unsaturated C = C bonds in the SBS molecules. According to the preparation process of modified asphalt, the influence of ultrasonic wave on rheological property of modified asphalt was studied through experiments. The results show that ultrasonic treatment can enhance the elasticity of asphalt and improve the temperature sensitivity of asphalt. With the increase of ultrasonic treatment time, the anti-rutting deformation ability of SBS modified asphalt is greatly improved. At the same temperature, the recovery rate of asphalt also increases with the increase of ultrasonic treatment time, and the non-recoverable compliance (Jnr) decreases Combined with the numerical simulation of cavitation bubbles, the ultrasonic process is added to asphalt production, which is of great significance for the green production of modified asphalt and the improvement of the rheological properties of modified asphalt.

The increasing pollution levels, rising energy demand, and the inadequacy of conventional fuels have spurred interest in alternative sources of fossil fuel supply and demand. This problem has shifted the focus towards the examination of a promising sustainable alternative for diesel fuels. In this sense, biodiesel can be a more suitable candidate for energy, environmentally harmless, and cost-competitive approach to respond to the energy demand. The application of ultrasonic energy in biodiesel production via transesterification has been endorsed as an efficient approach that improves mass transfer factors resulting in decreased reaction times and potentially lower process expense. This study investigates the advancements in ultrasonic energy for biodiesel generation from various raw materials utilizing different catalysts. A critical assessment of the current approach is furnished, emphasizing the application of ultrasonic irradiation. Besides, in order to better understand ultrasonic energy, each ultrasonic cavitation (UC) and hydrodynamic cavitation (HC) is discussed. Regarding each approach, the fundamental concepts are discussed in detail. Generally, the present study aims at conveying a comprehensive overview of ultrasonic energy usage in transesterification reactions and furnishing an outlook on prospective developments in the technology.

In a multi-bubble system, the bubble behavior is modulated by the primary acoustic field and the secondary acoustic field. To explore the translational motion of bubbles in cavitation liquids containing high-concentration cavitation nuclei, evolutions of bubbles are recorded by a high-speed camera, and translational trajectories of several representative bubbles are traced. It is found that translational motion of bubbles is always accompanied by the fragmentation and coalescence of bubbles, and for bubbles smaller than 10 μm, the possibility of bubble coalescence is enhanced when the spacing of bubbles is less than 30 μm. The measured signals and their spectra show the presence of strong negative pressure, broadband noise, and various harmonics, which implies that multiple interactions of bubbles appear in the region of high-intensity cavitation. Due to the strong coupling effect, the interaction between bubbles is random. A simplified triple-bubble model is developed to explore the interaction patterns of bubbles affected by the surrounding bubbles. Patterns of bubble interaction, such as attraction, repulsion, stable spacing, and rebound of bubbles, can be predicted by the theoretical analysis, and the obtained results are in good agreement with experimental observations. Mass exchange between the liquid and bubbles as well as absorption in the cavitation nuclei also plays an important role in multi-bubble cavitation, which may account for the weakening of the radial oscillations of bubbles. [ABSTRACT FROM AUTHOR]

Defect engineering constitutes a widely-employed method of adjusting the electronic structure and properties of oxide materials. However, controlling defects at room temperature remains a significant challenge due to the considerable thermal stability of oxide materials. In this work, a facile room-temperature lithium reduction strategy is utilized to implant oxide defects into perovskite BaTiO3 (BTO) nanoparticles to enhance piezocatalytic properties. As a potential application, the piezocatalytic performance of defective BTO is examined. The reaction rate constant increases up to 0.1721 min−1, representing an approximate fourfold enhancement over pristine BTO. The effect of oxygen vacancies on piezocatalytic performance is discussed in detail. This work gives us a deeper understanding of vibration catalysis and provides a promising strategy for designing efficient multi-field catalytic systems in the future. [ABSTRACT FROM AUTHOR]

Silicon carbide (SiC) is difficult to machine due to its high hardness and chemical inertness, and surface modification is a key pre-step in chemical mechanical polishing (CMP), SiC single crystal surface modification can promote surface material removal and increase surface flattening rate. To promote SiC surface oxidation efficiency, a green enhanced oxidation method named ultrasonic-assisted plasma electrochemical oxidation (UAPECO) that combines ultrasonic vibration and plasma electrochemical oxidation (PECO) is proposed. Experiments were conducted to evaluate the UAPECO performance and investigate the enhanced oxidation mechanism in UAPECO. The results confirmed that ultrasonic vibration effectively promotes SiC oxidation rate in UAPECO, and the oxidation rate of UAPECO was 24% higher than that of PECO under 200 V oxidation voltage. Combined with physicochemical effect of ultrasonic vibration, the oxidation enhancement mechanisms in UAPECO are that the ultrasonic high-frequency vibration in electrolyte promotes the electrolyte temperature on SiC surface and causes the cavitation effect and acoustic-chemical effect, and the compound effect enhances the oxidation reaction on SiC surface. UAPECO is a promising surface modification technology for SiC single crystal that can greatly improve the polishing efficiency applicable for CMP. [ABSTRACT FROM AUTHOR]

Since the majority of valuable components in spent lithium-ion batteries, such as lithium, exists in the electrode materials, common studies focused on the treatment of the cathode materials, which ignored the harm of residual electrolyte. The cavitation and thermal effects produced by ultrasonic can not only be used for the separation of electrode materials, but also have a wide range of applications in the field of sewage pollutant degradation. This work used ultrasonic to treat simulated electrolyte (propylene carbonate (PC)) solution of spent lithium-ion batteries, explored the effect of ultrasonic power, the addition amount of H2O2 solution (30 wt%) and reaction temperature on the degradation of electrolyte, and analysed the ultrasonic degradation reaction from the perspective of reaction kinetics. And the synchronous experiment of cathode material separation and electrolyte degradation was conducted under the optimal conditions. The results showed that the highest degradation efficiency of PC in the electrolyte was 83.08% under the condition of ultrasonic power of 900 W, the addition of H2O2 solution (30 wt%) of 10.2 mL, reaction temperature of 120°C and reaction time of 120 minutes, and the separation efficiency was 100%. This work reduced the environmental and health risks in the cathode material separation process and was conducive to the green development of spent lithium-ion battery recycling technology. [ABSTRACT FROM AUTHOR]

The propagations of acoustic waves in bubbly liquids have been extensively investigated through experimental and theoretical methods, a computational fluid dynamics (CFD) method was introduced to investigate the acoustic attenuation through bubbles in this study. Numerical 'measurements' of attenuation coefficient (α) and phase velocity (V) were conducted using a homogeneous cavitation model, which were modeled from experimental schemes and compared with the theoretical results. At extremely small bubble volume fraction (β around 10-11), new formulas of the theoretical α (αtheo) were proposed respectively for linear and transient oscillations, and a new formula of the numerical α (αnum) was proposed for transient oscillations. Results showed that αnum matched precisely with αtheo for linear, nonlinear and transient oscillations. At medium β (around 10-4), the relative difference of αnum between the VOF and present methods was less than 1.6%, while it reached 15.4% after replacing the bounded Keller-Miksis equation (KME) in the present method with the KME. However, the traditional theoretical α and V matched precisely with the predictions by the present method with the KME. Thus new theoretical α and V were proposed based on the bounded KME, and the relative differences between αtheo and αnum were less than 1%. It can be concluded that the bounded KME should be used in both numerical and theoretical predictions. [ABSTRACT FROM AUTHOR]

The increasing pollution levels, rising energy demand, and the inadequacy of conventional fuels have spurred interest in alternative sources of fossil fuel supply and demand. This problem has shifted the focus towards the examination of a promising sustainable alternative for diesel fuels. In this sense, biodiesel can be a more suitable candidate for energy, environmentally harmless, and cost-competitive approach to respond to the energy demand. The application of ultrasonic energy in biodiesel production via transesterification has been endorsed as an efficient approach that improves mass transfer factors resulting in decreased reaction times and potentially lower process expense. This study investigates the advancements in ultrasonic energy for biodiesel generation from various raw materials utilizing different catalysts. A critical assessment of the current approach is furnished, emphasizing the application of ultrasonic irradiation. Besides, in order to better understand ultrasonic energy, each ultrasonic cavitation (UC) and hydrodynamic cavitation (HC) is discussed. Regarding each approach, the fundamental concepts are discussed in detail. Generally, the present study aims at conveying a comprehensive overview of ultrasonic energy usage in transesterification reactions and furnishing an outlook on prospective developments in the technology. [ABSTRACT FROM AUTHOR]

Infections caused by Pseudomonas aeruginosa biofilm significantly endanger human health worldwide. Biofilms are closely associated with antibiotic resistance because biofilms significantly undermine the efficacy of antibiotics. A novel ultrasound-launched targeted nanoparticle was developed to universally destroy biofilm, target bacteria, deliver antibiotics, and efficiently kill bacteria via ultrasonic cavitation and antibacterial sonodynamic therapy. The nanoparticle consisted of poly (lactic-co-glycolic acid) loading ciprofloxacin and perfluoropentane with a bacteria-targeted antibody installed on the nanoparticle for binding to specific bacteria. The nanoparticle exhibited a sensitive response to ultrasound and the rapid liquid-gas phase transition of perfluoropentane resulted in a cavitation effect that destroyed the extracellular polymeric substances of the biofilm and allowed deep penetration of the antibiotics. In addition, ciprofloxacin induced additional reactive oxygen species production under ultrasound stimulation, leading to an enhanced bactericidal effect and potent anti-infective activity in vivo. This study presents an effective strategy to tackle the extracellular polymeric substance barriers for overcoming antibiotic resistance and removing a biofilm.

Abstract The Ultrasonic cavitation effect has been widely used in mechanical engineering, chemical engineering, biomedicine, and many other fields. The quantitative characterization of ultrasonic cavitation intensity has always been a difficulty. Based on this, a fluorescence analysis method has been adopted to explore ultrasonic cavitation intensity in this paper. In the experiment of fluorescence intensity measurement, terephthalic acid (TA) was used as the fluorescent probe, ultrasonic power, ultrasonic frequency, and irradiation time were independent variables, and fluorescence intensity and fluorescence peak area were used as experimental results. The collapse of cavitation bubble will cause molecular bond breakage and release ·OH, and the non-fluorescent substance TA will form the strong fluorescent substance TAOH with ·OH. The spectra of the treated samples were measured by a F-7000 fluorescence spectrophotometer. The results showed that the fluorescence intensity and fluorescence peak area increased rapidly after ultrasonic cavitation treatment, and then increased slowly with the increase of ultrasonic power, which gradually increased with the increase of irradiation time. They first decreased and then increased with the increase of ultrasonic frequency from 20 kHz to 40 kHz. The irradiation time was the most influential factor, and the cavitation intensity of low frequency was higher overall. The fluorescence intensity and fluorescence peak area of the samples increased by 2–20 times after ultrasonic treatment, which could increase from 69 and 5238 to 1387 and 95451, respectively. After the irradiation time exceeded 25 min, the growth rate of fluorescence intensity slowed down, which was caused by the decrease of gas content and TA concentration in the solution. The study quantitatively characterized the cavitation intensity, reflecting the advantages of fluorescence analysis, and provided a basis for the further study of ultrasonic cavitation.

Ti–Ta alloy micro-nano surface processing is crucial for achieving biocompatibility. To investigate the cavitation and micro-abrasive particle damage characteristics, and the deformation mechanism of Ti–Ta alloy material surface, indentation theory, and the J-C constitutive model were adopted. Numerical load prediction models for ultrasonic cavitation and micro-abrasive particles' impact on Ti–Ta alloy surfaces were developed, and the erosion behaviors of ultrasonic cavitation and micro-abrasive particles’ impact on Ti–Ta alloy surfaces individually and in synergy were experimentally investigated. The inversion analysis shows that the range of ultrasonic cavitation impact load is 0.025–1.015 N, and there are material peeling and interconnection phenomena in the cavitation erosion pit. On the other hand, the impact load range of 10 μm spherical smooth SiO2 micro-abrasive particles is 0.107–0.814 N, and there is no material peeling or interconnection phenomenon in the micro-abrasive particle erosion pit. Additionally, the cavitation erosion rate is determined through changes in roughness and depression volume, resulting in a rate of 38.6%. In contrast, the cavitation-induced micro-abrasive particle erosion rate reached 166.4%. The results show that the impact load and erosion rate of ultrasonic cavitation-induced micro-abrasive particles are greater than those of cavitation impact load and erosion rate. Furthermore, ultrasonic cavitation-induced micro-abrasive particles impact is found to be more conducive to achieving micro-nano processing of Ti–Ta alloy surface.

With the increasing demand for deep oil and gas exploration and CCUS (Carbon Capture, Utilization, and Storage) engineering, improving rock-crushing efficiency stands as a pivotal technology. Ultrasonic vibration-assisted drilling has emerged as a novel rock-breaking technology. The high-frequency vibrations of ultrasonic waves impact rocks, inducing resonance and accelerating their fragmentation. At the same time, ultrasonic waves generate cavitation bubbles in the liquid near rock surfaces; the expansion and collapse of these bubbles further contribute to rock damage, thereby improving crushing efficiency. Therefore, investigating the dynamics and failure characteristics of cavitation bubbles near rock surfaces under ultrasonic influence is crucial for advancing ultrasonic-assisted rock-breaking technology. This study treats the liquid as compressible flow and investigates the movement and rupture of bubbles near rock surfaces under varying ultrasonic parameters, rock properties, characteristics of the circulating medium, and other relevant factors. The findings show that ultrasonic waves induce the oscillation, translation, collapse, and rebound of bubbles near rock surfaces. Higher ultrasonic frequencies correspond to larger collapse pressures and amplitudes near surrounding rocks, as well as longer expansion times and shorter collapse durations. In addition, bubble movement and collapse lead to rock material deformation, influenced by the rheological properties of the liquid medium. The study outcomes serve as a foundation for optimizing engineering parameters in ultrasonic-assisted rock breaking and provide theoretical support for the advancement of this technology.

Coalbed methane (CBM), recognized as a sustainable and environmentally friendly energy source, plays a crucial role in mitigating global climate change and advancing low-carbon energy solutions. However, the prevalence of low-permeability coal seams poses a significant challenge to effective CBM extraction. Improving coal permeability has emerged as a viable strategy to address the issue of low-permeability coal. Conventional CBM stimulation methods fall short in overcoming this obstacle. In contrast, the enhanced technique of CBM extraction by water-based ultrasonic cavitation holds great promise due to its use of high energy intensity, safety, and efficiency. Nevertheless, the inadequate theoretical framework for managing this technology impedes its widespread adoption for large-scale applications. This study investigated the impact of water-based ultrasonic cavitation treatment on coal’s properties and permeability through mechanical testing and permeability measurements conducted before and after treatment. This study also explored the process by which this technology, known as WUC-ECBM, improves coal’s mechanical properties and permeability. The findings suggest a potential stimulation technique (WUC-ECBM) for use in CBM extraction, and its physical mechanism.

Integrating and dispersing one-dimensional (1D) nano reinforcements in metal matrix composites (MMC) is challenging due to their higher specific surface area, strong van der Waals forces within the nano reinforcement, and poor wettability with the matrix. In the present study, ultrasonic cavitation-assisted casting was employed to fabricate boron nitride nanotubes (BNNT)-reinforced aluminum matrix composites. The ultrasonic treatment (UST) demonstrated excellent deagglomeration, and dispersion of BNNTs in molten aluminum along with enhanced grain refinement potency. A remarkable ∼62% grain refinement efficiency in Al-BNNT composite compared to pure Al was achieved owing to the combined effect of UST, BNNT reinforcement and cold rolling. The increase in low-angle grain boundaries (LAGBs) by ∼58% in Al-BNNT composite, as revealed by electron backscatter diffraction (EBSD) maps, demonstrates the pileup of dislocations resulting in strength improvement. The yield strength exhibited a 97% improvement in the BNNT-reinforced composite compared to pure Al. The strengthening is attributed to UST, enhanced dislocation density and efficient bridging effect between BNNTs and the matrix. Thus, the present study constitutes the first successful report on the role of UST in the mechanism of BNNT dispersion, grain morphology and enhanced mechanical properties, including cold rolling of BNNT-reinforced MMC. Successful dispersion of BNNTs by ultrasonic cavitation confirms that UST technology is a promising method for manufacturing high-strength nanoparticle-reinforced lightweight metal matrix composites.

Copyright of Industrial Water Treatment is the property of CNOOC Tianjin Chemical Research & Design Institute and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The Ultrasonic cavitation effect has been widely used in mechanical engineering, chemical engineering, biomedicine, and many other fields. The quantitative characterization of ultrasonic cavitation intensity has always been a difficulty. Based on this, a fluorescence analysis method has been adopted to explore ultrasonic cavitation intensity in this paper. In the experiment of fluorescence intensity measurement, terephthalic acid (TA) was used as the fluorescent probe, ultrasonic power, ultrasonic frequency, and irradiation time were independent variables, and fluorescence intensity and fluorescence peak area were used as experimental results. The collapse of cavitation bubble will cause molecular bond breakage and release ·OH, and the non-fluorescent substance TA will form the strong fluorescent substance TAOH with ·OH. The spectra of the treated samples were measured by a F-7000 fluorescence spectrophotometer. The results showed that the fluorescence intensity and fluorescence peak area increased rapidly after ultrasonic cavitation treatment, and then increased slowly with the increase of ultrasonic power, which gradually increased with the increase of irradiation time. They first decreased and then increased with the increase of ultrasonic frequency from 20 kHz to 40 kHz. The irradiation time was the most influential factor, and the cavitation intensity of low frequency was higher overall. The fluorescence intensity and fluorescence peak area of the samples increased by 2–20 times after ultrasonic treatment, which could increase from 69 and 5238 to 1387 and 95451, respectively. After the irradiation time exceeded 25 min, the growth rate of fluorescence intensity slowed down, which was caused by the decrease of gas content and TA concentration in the solution. The study quantitatively characterized the cavitation intensity, reflecting the advantages of fluorescence analysis, and provided a basis for the further study of ultrasonic cavitation. [ABSTRACT FROM AUTHOR]

The article provides an analytical review of known methods of degassing process liquids. An analysis of the advantages and disadvantages of known methods of degassing these liquids is presented. Emphasis is placed on the ultrasonic method of degas-sing, which is implemented by introducing an ultrasonic deformation wave into the liquid. The review shows different types of ultrasonic emitters built according to half-wave and wave acoustic schemes. Photographic materials and graphics of an exper-imental study of the ultrasonic method of degassing technological liquids with the involvement of piezoelectric transducers are used. The physical model of the process of ultrasonic degassing of the above-mentioned liquids is considered in the article. The necessity of carrying out works with the aim of additional study and improvement of the efficiency of ultrasonic degassing of technological liquids by means of an experimental study of the effect on the degassing process of the frequency, amplitude and intensity of ultrasonic oscillations is emphasized. Conclusions were made regarding the prospects of using the ultrasonic meth-od of liquid degassing. [ABSTRACT FROM AUTHOR]

Objective: To study the mechanism of ultrasonic emulsification of soy protein isolate (SPI) and to investigate the emulsification efficiency of SPI under different ultrasonic powers. Methods: Different ultrasonic powers of 28, 47, 69, 88 and 109 W were used to treat SPI emulsions. The finite element analysis method was applied to simulate the phenomenon of acoustic streaming in the sound field and obtain the distribution of acoustic flow field under different ultrasonic powers. The distribution characteristics of the ultrasonic cavitation field were analyzed by sonochemiluminescence assay. The particle size, emulsification activity, and emulsion stability of SPI emulsions were measured. Results: The effect of ultrasonic cavitation, the cavitation enhancement of acoustic flow, the dispersion and mixing of acoustic flow were the main mechanisms for the homogeneous stabilization of ultrasonic emulsification. Ultrasonic disruption and homogenization as a result of acoustic cavitation could reduce the particle size of SPI emulsions. The acoustic flow effect caused by an increase in ultrasonic power could increase the action area of ultrasonic cavitation enhancing the cavitation effect. Meanwhile, the impact, gyration and vortex motion of acoustic flow could cause the emulsion to be fully stirred, dispersed and mixed, effectively improving the emulsification activity, emulsion stability and apparent stability. The emulsification efficiency of SPI was highest when the ultrasonic power was 88 W. Conclusion: Increased ultrasonic power can effectively improve the emulsification characteristics of SPI.

Stir-casting with ultrasonic cavitation produced nano-Al2O3-filled AA7150 matrix composites in this study. The SEM microstructure study shows that all composites include nano-Al2O3 particles with consistent particle sizes and homogenous distribution. EDS and XRD showed no secondary phases or impurities in the composite. Optical microscopy showed intense ultrasonic cavitation effects, and nano-Al2O3 particles caused grain refinement in the AA7150 matrix. The composite’s mechanical characteristics improved when the Al2O3 nanoparticle weight percentage (wt.%) increased. With only 2.0 wt.% nano-Al2O3 particles, the composites yielded 232 MPa, 97.52% higher than the sonicated AA7150 matrix alloy. Multiple models were used to characterize the strength of the AA7150 nano-Al2O3 composite. The findings showed that thermal incongruity, Orowan strengthening, the Hall–Petch mechanism, and load transfer effects contributed the most towards the increased strength of the composite. Increasing the nano-Al2O3 wt.% in the AA7150 matrix improved hardness by 95.08%, yield strength by 90.34%, and sliding wear resistance by 46.52%. This enhancement may be attributed to the combined effects of better grain refinement, enhanced dispersion with dislocation strengthening, and better load transfer between the matrix and reinforcement, which are assisted by the inclusion of reinforcements. This result was confirmed by optical studies.

Copyright of Chemical Engineering (China) / Huaxue Gongcheng is the property of Hualu Engineering Science & Technology Co Ltd. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

A facile and robust ultrasonic micromixer was developed to intensify antisolvent precipitation via ultrasonic cavitation. The gas supersaturation created from solvent–antisolvent mixing was found to be a novel driving force which facilitated the generation of cavitation bubbles (CBs). Instead of being attached on the channel wall, numerous CBs translated across the microchannel at a speed up to 1.7 m/s, inducing intense transverse flow over the cross‐section. The unique cavitation behavior enabled rapid mixing (mixing time 15–45 ms at 30 W) of solvent–antisolvent over wide Reynolds number range (70–500) and flow rate ratio (5:1–2:3), providing better operability for antisolvent precipitation. The effects of ultrasonic power, total flow rate, flow rate ratio, and solvent on cavitation behavior and mixing performance were quantitatively studied. Finally, the potential of the ultrasonic micromixer as a new tool for antisolvent precipitation was demonstrated by synthesizing size‐controllable and monodisperse polymeric nanoparticles in a high‐throughput and reproducible manner. [ABSTRACT FROM AUTHOR]

The features of the impact of acoustic flow and cavitation created by a traveling ultrasonic wave, which can be used for efficient dissolution of a metal oxide powder, are considered. On the basis of a simplified scheme, which, nevertheless, takes into account all the essential features of the phenomenon under study, exact expressions are obtained for all parameters of stationary vortex motion and cavitation, which fully meet the requirements for proper control of the reaction course. Equations are derived that describe the dissolution kinetics for two typical regimes: developed cavitation and pre-cavitation state. Expressions are found for the time to completion of the process. On the example of these two most typical types of reaction, the conditions are formulated under which it will be possible to fully satisfy the solution of the technological challenges. The methods for the optimal application of the ultrasonic dissolution scheme are presented and those features of its formation that make it possible to control the process are noted. The performed calculations make it possible to select and accurately implement the scheme of acoustic stimulation of dissolution which best corresponds to the expected output results and other processing features. [ABSTRACT FROM AUTHOR]

Copyright of Iraqi Journal of Chemical & Petroleum Engineering is the property of Republic of Iraq Ministry of Higher Education & Scientific Research (MOHESR) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Azo dyes such as Congo red can easily cause cancer when they come into contact or are absorbed by the human body, so it is urgent to find a fast and simple method for degrading Congo red. In order to better achieve this research goal, an ultrasonic method was used to degrade Congo red solution in a rotating flow field. The concentration of hydroxyl radical in the solution was significantly increased under the action of ultrasonic cavitation, chemical action of zero valent iron, and mechanochemistry. Under the strong oxidation of hydroxyl radical and the reduction of nano zero valent iron peeled off in the reaction process, the reaction speed is significantly accelerated and should promote the reaction. The effect of increasing stirring and adding iron powder particles on ultrasonic cavitation was studied by numerical simulation, and the yield of hydroxyl radical in the system was measured by fluorescence analysis. The experimental results show that, first, the rotating field formed by mixing increases the uniformity of ultrasonic sound field distribution and the amplitude of sound pressure, and it improves the cavitation intensity. In the effective dispersion area, the strong ultrasonic wave can form a temporary high-energy microenvironment in the suspension through cavitation, generate high strength shockwaves and micro jets, and thus significantly deagglomerate the iron powder aggregates. The addition of iron powder particles then provides a complementary Fenton reagent for the degradation reaction. The concentration of hydroxyl radicals in the solution was significantly increased by the synergy of the two actions. The degradation rate of Congo red reached more than 99% after 30 min of reaction. [ABSTRACT FROM AUTHOR]

The structure of the sonoluminescence spectra of argon-saturated aqueous solutions of CaCl2 and NaCl of various concentrations is considered in detail. The frequency of ultrasound is 20 kHz, and the output power is 18 W. The spectrum of the CaCl2 solution changes considerably as the concentration rises. The intensity of the continuum passes through a maximum near the saturation concentration. Atomic, ionic, and molecular metal lines are observed for medium concentration values and disappear at high concentrations. Similar behavior is displayed by the spectra of NaCl solutions. The differences between the spectra are explained by the change in the vapor–gas content of the bubbles and the nature of their population, from large and non-inertial to small and pulsating inertially. [ABSTRACT FROM AUTHOR]

Copyright of Shipin Kexue/ Food Science is the property of Food Science Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)