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High-volume fraction silicon carbide particle-reinforced aluminum matrix (SiCp/Al) composites are crucial materials in the aerospace industry, requiring precision milling to ensure accurate mating surfaces. However, achieving low-damage machining of SiCp/Al remains challenging. Traditional dry machining methods often affect surface integrity, while minimum quantity lubrication (MQL) has emerged as a more sustainable alternative to flood cooling. Despite this, the tool's air barrier layer in MQL limits the lubricant flow to the tool-workpiece interface, reducing cooling and lubrication efficiency. To overcome this, an ultrasonic-enabled MQL (UV-MQL) technique for milling SiCp/Al is proposed. However, research on the effects and mechanisms of ultrasound-enabled nanolubricants in the milling of SiCp/Al composites remain limited. To fill this gap, milling experiments were conducted under various cooling and lubrication conditions. The performance of UV-MQL was assessed using key parameters such as milling force, specific cutting energy, and surface topography. Results showed that UV-MQL and UV-NMQL reduced specific cutting energy by 25.44% and 32.55%, respectively, compared to conventional MQL milling, while surface roughness (Sa values) decreased by 14.44% and 38.22%. To further explain these outcomes, the anti-friction mechanism of the ultrasonically enabled nanolubricant was analyzed, focusing on droplet wetting, penetration, and film formation. These findings provide valuable insights for improving surface integrity in the SiCp/Al milling process. [ABSTRACT FROM AUTHOR]

Minimum quantity lubrication (MQL) technology offers cooling and lubrication for material cutting by atomizing cutting oil through high-pressure gas and injecting it into the cutting zone. The improvement in cutting performance is often associated with the droplet size, density, and velocity generated by the MQL device. Ultrasonic vibration-assisted MQL (UVMQL) is an innovative and enhanced MQL technique that exhibits excellent atomization properties for superior cooling and lubrication during machining. In this study, an UVMQL device was developed, and Fluent simulation was employed to enhance the inflow and ejection states of the droplets while optimizing the structural parameters within the nozzle. The spray characteristics of the device were evaluated using silicon wafer droplet analysis combined with image processing technology. Results demonstrate that applying ultrasonic vibration reduces the droplet size of MQL by 35.6%, leading to a more concentrated size distribution and higher velocity reaching the cutting zone. As gas pressure increases, there is a decrease in the difference between UVMQL and MQL droplet sizes from 3.4 to 1.2 µm, indicating a diminishing effect of ultrasonic vibration on droplet size improvement over time. Finally, milling experiments were conducted on ultra-high strength steel to investigate how parameter variations affect milling performance under both MQL and UVMQL conditions. It was observed that increasing inlet pressure by 300 kPa resulted in reductions of main cutting forces under MQL conditions by 15 N, whereas under UVMQl conditions, these forces decreased by 20.3 N due to improved spray characteristics facilitated by ultrasonic vibration effects. When increasing the flow rate of cutting oil, surface topography improvements were more pronounced under UVMQL conditions, as evidenced by a decrease in Ra value of 19.4%, thus highlighting how ultrasonic vibration indirectly enhances material milling performance. [ABSTRACT FROM AUTHOR]

Efficiently breaking the oxide layer and rapidly diffusing of elements at low-temperature has been a longstanding goal in the diffusion bonding (DB) of Al alloys. To break the interfacial oxide layers and accelerate atomic diffusion, ultrasound energy was introduced during the DB of 6063Al. A full Zn–Al eutectoid joint was manufactured via a pure Zn interlayer at 360 °C in atmospheric by an ultrasonic-assisted diffusion bonding (U-DB) at only an ultrasonic vibration of10 min. During U-DB, brittle cracks were formed in the interfacial oxide layers due to high strain rate induced by ultrasonic action. Zn diffused into Al alloy through the brittle cracks in oxide layers via "subcutaneous diffusion," forming a Zn–Al eutectoid diffusion region between the Al alloy and oxide layer. The oxide fragments irregularly migrated to the center of the joint due to Kirkendall effect and ultrasonic action, finally dispersed in the bonded metal. The bonded metal finally transformed as a full Zn–Al eutectoid phase after consuming interlayer. The shear strength of the Zn–Al eutectoid joint reached 82.6 MPa. The Zn–Al mutual diffusion coefficient of U-DB at 360 °C was ∼0.6 μm2/s, which was about 20 times higher than the thermal diffusion coefficient under same temperature condition. Additionally, the mechanism of ultrasonic-assisted diffusion based on the strain-driven diffusion mode was discussed in detail. [ABSTRACT FROM AUTHOR]

Weld lines are common surface defects in micro-injection molding (µIM) and degrade the appearance quality and material properties of polymer parts. The restraining effects of the two-dimensional ultrasonic vibration (2DUV) on weld lines are investigated, and the feasibility of the 2DUV in reducing the weld line dimensions and improving the material properties is verified. The results show that the 2DUV outperforms the one-dimensional ultrasonic vibration (1DUV) in restraining weld lines. By raising the polymer melt temperature, reducing the flow pressure loss, and improving the melt fluidity, the 2DUV facilitates the formation of smaller weld lines, achieving the largest reductions of 3% (76.8 µm), 31% (25.8 µm), and 23% (2.0 µm) in the length, width, and depth, respectively, compared with no ultrasonic vibration (NUV). Simultaneously, the 2DUV weakens the polymer molecule orientation and promotes the crystallization, leading to a more significant enhancement in the material properties of the weld line area than the 1DUV, in which the elastic modulus and hardness of the start area of the weld line are 1.06 GPa and 0.072 GPa, respectively, showing the largest increases of 8.5% and 12.5%, compared with the NUV. Furthermore, the 2DUV reduces the material anisotropy of the weld line area and is superior to the 1DUV in improving the uniformities of the material properties. Compared with the NUV, the largest improvements of the uniformity of the elastic modulus and hardness in the weld line area under the 2DUV are 76% and 93%, respectively, and those in the whole bottom are 94% and 80%, respectively. [ABSTRACT FROM AUTHOR]

The use of ultrasonic technology for rock breaking, with its high-frequency and microamplitude impact load, is anticipated to help overcome the challenges of high economic cost and low rate of penetration in mineral resource exploration. A three-dimensional finite-element model of a heterogeneous granite mineral crystal was created using random Voronoi tessellation and cohesive elements. The distribution of the multipolycrystalline structure was achieved in a proportional manner. Then, the differences between conventional cutting and ultrasonic-assisted cutting in rock breaking were compared. The effects of different vibration frequencies (20–35 kHz) and amplitudes (10–50 μm) on crack propagation, crack size, stress distribution, and energy consumption were investigated. The results indicate that higher ultrasonic vibration frequencies significantly improve crack formation, with enhancements ranging from 25.16% to 44.30% compared to conventional cutting. It is important to note that ultrasonic load plays a crucial role in enhancing rock-breaking efficiency by enlarging crack sizes and increasing the number of intergranular tensile cracks instead of solely increasing the total number of cracks. When the vibration frequency is 30 kHz, the crack volume and the proportion of intergranular tensile cracks reach their peak values, while the cutting force decreases to its lowest point, 74.51% lower than conventional cutting. Increasing the vibration frequency is advantageous for reducing mechanical energy consumption. However, once the vibration frequency surpasses 30 kHz, further increasing it does not significantly enhance the ultrasonic effect. Additionally, raising the amplitude can increase the quantity and size of cracks, leading to an effective improvement in the stress situation of the polycrystalline diamond compact cutter. [ABSTRACT FROM AUTHOR]

The nanometer-sized pores within coal are the primary sites for CH4 adsorption and competitive adsorption with CO2. Reasonable modification of the nanopore structure to enhance CH4 desorption, diffusion rates, and CO2 competitive adsorption effects can enhance significantly coalbed methane (CBM) production. However, ultrasonic synchronous modification of multiple features of nanopores leads to complex and variable gas adsorption behaviors in coal. To reveal the effect of ultrasonic modification of coal nanopores on gas adsorption, pore measurement experiments and molecular simulation studies were conducted. The results showed that the volume ratio of diffusion pores to adsorption pores (V2/V1) decreased significantly after ultrasonic excitation. In the original coal sample, V2/V1 was 3.05, while in the coal sample after ultrasonic treatment, V2/V1 ranged from 0 to 2.54. With decrease in the proportion of the volume of diffusion pores, the proportion of CH4 migration from the pore walls of the adsorption pores increased continuously. The proportion of CH4 migration from the pore walls of the diffusion pores to the pore space of the diffusion pores decreased continuously. The results of gas–solid interaction energy calculation showed that ultrasonic treatment of coal decreases the V2/V1 ratio, leading to 7.1–23.3% increase in CO2 competitive adsorption effect. It also resulted in 4–49% improvement in competitive adsorption efficiency. Additionally, based on gas–solid interaction energy data, an adsorption capacity evaluation model for coal under different gas compositions and pore volume ratios was constructed. The findings can guide ultrasonic-enhanced CBM. [ABSTRACT FROM AUTHOR]

Single-crystal sapphire (α-Al2O3) has a wide range of applications in a variety of extreme environments due to its excellent mechanical and chemical properties as well as its stability under extreme service conditions. In addition, sapphire is a hard and brittle material, which makes it difficult to avoid the introduction of subsurface damage during processing, and the existence of a subsurface damage layer seriously affects the performance of the optical system. Therefore, this study focuses on the mechanism of subsurface damage in sapphire grinding, the suppression of damage depth, and the accurate and fast prediction of damage depth. A subsurface damage model for ultrasonic vibration–assisted grinding of sapphire was established by combining ultrasonic vibration single abrasive grain kinematics and dynamics analysis. The mechanism of ultrasonic vibration–assisted grinding was investigated by combining force and acoustic emission (AE) signals. And the effects of ultrasonic vibration–assisted grinding on the surface quality, subsurface damage form, and depth were analyzed. A comprehensive prediction model of SSD based on surface roughness (Sz) was established by combining indentation fracture mechanics and Gaussian process regression. Finally, by analyzing the influence law of each process parameter on the subsurface damage depth (SSD), the grinding process parameters were optimized, and the subsurface damage suppression strategy was proposed. This study provides theoretical guidance for the high-efficiency and low-damage grinding of sapphire. [ABSTRACT FROM AUTHOR]

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]

The debonding fiber defects on the grinding surface of SiO2f/SiO2 ceramic matrix composites deteriorate the service performance of related components. The low-damage process window is the key information to suppress machining damage by controlling grinding parameters. A mechanism model for debonding fiber damage on SiO2f/SiO2 surface was first proposed in this paper by the large deformation analysis for SiO2 fibers during rotary ultrasonic face grinding (RUFG). The established mechanism model built a bridge between grinding parameters and damage inhibition by integrating the ultrasonic stress effect, grinding force calculation, and critical fracture curvature cutting-off criterion of SiO2 fibers. The modeling mechanism for fiber deformation and fracture in grinding was validated by in situ observation of single abrasive grit scratching experiments. Besides, the low debonding damage process window predicted by the model was verified by experimental results and could be adopted to suppress the debonding fiber damage in grinding. The affected mechanism of fiber orientation, ultrasonic amplitude, and fiber-matrix interface strength on the low debonding damage process window was analyzed based on the theoretical and experimental results. The damage inhibition effect of the RUFG process was limited by the low fiber-matrix interface strength and axial cutter-relieving movement component. The ultrasonic-assisted vibration exerted its auxiliary effects through the ultrasonic stress effect and force reduction effect. The prerequisite for exerting the damage inhibition effect of RUFG was that the fiber-matrix interface strength was sufficient to resist the negative influence of the ultrasonic stress effect. [ABSTRACT FROM AUTHOR]

With the development of science and technology, industrial production requires more and more precise parts processing, precision processing has become a trend. In this trend. The traditional processing methods have been difficult to meet the market demand for micro-hole parts. Therefore, combining the characteristics of EDM and Ultrasound-assisted Machining, a new horizontal Ultrasound-assisted EDM system for deep and small holes is designed and applied in physical machining. The experimental results show that the horizontal ultrasonic vibration of workpiece can promote the efficiency and depth of EDM, and improve the electrode wear and the inner surface roughness of small holes. By comparing the processing effects of different materials, it is found that the processing efficiency and depth of pig iron are better than those of stainless steel. In conclusion, the horizontal ultrasonic vibration system established in this paper not only improves the processing effect of conventional EDM to a certain extent, but also does not affect the spindle feed and working fluid circulation of EDM machine tools. It enriches the research direction of ultrasonic assisted EDM and has broad market prospects. [ABSTRACT FROM AUTHOR]

The dispersion of nano‐SiO2 (NS) in cement plays a critical role in enhancing the properties of cementitious materials. In this study, the combination of ultrasonic dispersion and polycarboxylic acid water reducing agent (PCE) was used to significantly improve the dispersion of NS. The effects of ultrasonic dispersion time, NS content, and PCE content on dispersion quality were investigated, alongside their impact on mechanical properties, electrical resistivity, and frost resistance. The results demonstrated that this synergistic method optimized the dispersion of NS, leading to superior mechanical properties and frost resistance. With an ultrasonic dispersion time of 40 min, NS content of 1.0 wt.%, and PCE content of 0.75 wt.%, the cement paste achieved its optimal performance. Compared to non‐dispersed samples, compressive strength increased by 33.7%. After 75 freeze–thaw cycles, the mass loss was 2%, the relative dynamic elastic modulus was 99.15%, and the strength loss was 13.74%. [ABSTRACT FROM AUTHOR]

Background and Objectives: Diffusion of hydroxide (OH)− and calcium (Ca)++ ions through dentin may cease external root resorption. Calcium hydroxide (Ca(OH)2), mineral trioxide aggregate (MTA), and calcium‐enriched mixture (CEM) cement are the choices for this purpose due to their optimal properties. This study sought to analyze the effects of ultrasonic activation (UA) on pH and the release of calcium ions from Ca(OH)2, MTA, and CEM cement in external root resorption artificial defects. Materials and Methods: This in vitro research involved the instrumentation and shaping of the root canals of 150 single‐rooted teeth (#F4). External defects were intentionally made on the middle one‐third of the root surface. Teeth were randomly assigned to a negative control group (n = 10), one positive control group (n = 20), and six experimental groups (each n = 20) according to the root canal filling material (Ca(OH)2 paste, MTA, CEM, gutta‐percha, Ca(OH)2 paste+ultrasonic, MTA + ultrasonic, and CEM + ultrasonic). Ultrasonic energy was transferred to the test materials using a #25 spreader. Ca++ concentration and pH were measured after 1, 7, 15, and 30 days in all groups. Statistical analysis involved the use of repeated measure analysis of variance (ANOVA) and paired‐sample T‐test (P ≤ 0.05). Results: The levels of calcium ions and pH increased significantly over time in all groups (P < 0.001). There were significant differences between the experimental groups in terms of pH and the concentration of released calcium ions at different times (P < 0.001). The Ca(OH)2 plus ultrasonic energy group ranked first, while the gutta‐percha group ranked last in terms of release of calcium ions and pH. Conclusion: The Ca(OH)2, MTA, and CEM cement groups showed an increase in pH and the release of calcium ions at the external root resorption defects. Additionally, the application of ultrasonic energy increased the release of calcium ions at these sites. [ABSTRACT FROM AUTHOR]

This study evaluated the direct and indirect thermal effects of various surgical energy devices using an ex-vivo model. Two types of three devices were evaluated: ENSEAL™ X1 Curved Jaw Tissue Sealer (X1) and ENSEAL™ G2 Curved Tissue Sealer (G2) as vessel sealing systems (VSSs), and HARMONIC® HD1000i Shears (HA) as an ultrasonic activating device (USAD). Each device was activated once under DRY or WET conditions. The tissue's maximum temperature (MT), steam MT surrounding the activation site, and steam spread area (SSA) were measured. Under WET conditions, the median MT of a porcine common carotid artery at 1 mm from the activation site by X1, G2, and HA were 84.4, 83.3, and 50.5 °C, respectively. The direct thermal effect of HA was the lowest among the three devices. VSSs showed higher tissue MT under WET conditions compared with DRY conditions. Conversely, USAD showed the opposite trend. G2 demonstrated a significantly higher MT than X1 and HA (P < 0.05). A significant decrease in SSA was observed with decreasing grasping range. In conclusion, VSSs generated higher temperatures than USAD, especially under WET conditions. Surgeons should consider minimizing thermal effects by creating DRY conditions or performing gradual incisions when using VSS devices. [ABSTRACT FROM AUTHOR]

AbstractThe study aims to explore the feasibility of using low-frequency ultrasonic washing to pre-concentrate iron values in waste bauxite residue (BR) containing 32.60 wt. % iron. This novel approach involves ultrasonication followed by water-washing to pre-concentrate iron before reduction-roasting of BR. Conventional reduction-roasting of BR is more expensive compared to pre-concentrated BR, making this method potentially cost-effective. The process consists of a two-stage ultrasonic treatment procedure. In the first stage, ultrasonication at 30 °C, with 40% solid content (w/v) for 30 min, improves the iron grade to 41.2 wt. % with 82% recovery. However, a second stage of ultrasonication is necessary to further upgrade the iron. The study optimized the ultrasonication time, temperature, solid content (%, w/v), and water washing parameters. Under optimal conditions (ambient temperature, 30% solid content (w/v), 45 min of ultrasonication), the iron grade reached 49.1 wt. % (Fe2O3 70.2) with 66% recovery. Water-washing parameters were found to be less effective compared to ultrasonication parameters. The settling time after water washing significantly affects the grade and recovery of the product. The ultrasonic effect on the BR particle surface leads to the breakage of surface-alkali coating and the disintegration of locked particles to generate free iron and other particles. Particle size analysis supports the disintegration of BR particles into smaller pieces. The physicochemical characterizations of different products were carried out using ICP-OES, XRD, FTIR, and FESEM studies to support the experimental findings. The possible iron separation mechanism is discussed utilizing available literature, as well as experimental and characterization evidence. [ABSTRACT FROM AUTHOR]

In this study, the effect of ultrasonic vibration during Friction Stir Vibration Processing (FSVP) on the microstructure and mechanical behaviour of AZ31/TiC surface composites was investigated. Specifically, Titanium Carbide (TiC) particles were introduced as a reinforcement (15 vol%) into the magnesium alloy AZ31 using both Friction Stir Processing (FSP) and FSVP. Comprehensive examinations were carried out to analyse the microstructure, hardness, and tensile behaviour of the resulting composites. The study revealed significant improvements in mechanical properties due to the application of ultrasonic vibration during FSP. Firstly, the stir zone region was found to be free from voids, enhancing material flow and promoting even dispersion of TiC powders within the matrix. Secondly, refinement of grains was observed due to dynamic recrystallization and the pinning effect imposed by TiC particles, leading to the formation of more dislocations in the composite and indicating a considerable alteration in the material's structure. Importantly, the vibration during FSP introduced an auxiliary energy source, resulting in a remarkable enhancement in both hardness and tensile strength. Compared to the AZ31/15 vol% TiC FSP composite, the composites produced via FSVP exhibited a grain size reduction of about 64% and improvements in hardness and ultimate tensile strength (UTS) of about 55% and 21%, respectively. Notably, these improvements were achieved without compromising the ductility of the composite, which remained at appreciable levels. [ABSTRACT FROM AUTHOR]

In order to explore the effects of ultrasonic vibration on the residual stresses generated during single-point incremental forming, simulations and experimental verification were performed during this study. The relationship between the residual stress and the springback along the generatrix of a part, the residual stress variation trends in different directions along the thickness of the part, and the residual stress variation trends and spring-back in different regions of the part were investigated under the action of ultrasonic vibration. It was found that the amplitude of the wall residual stress varied significantly along the thickness direction in each region, while the circumferential residual stress exhibited a trend of decreasing tensile stress from the internal surface to the external surface along the thickness direction in each region. The normal residual stress, however, was too small and its variations were not obvious. After ultrasonic vibration was introduced, the maximum value of the circumferential residual stress decreased by 30.02 MPa, the maximum value of the wall residual stress decreased by 18.84 MPa, and the minimum deviation between the actual sidewall angle and the theoretical sidewall angle reached 0.42°. The springback suppression effect was improved by 44.08 %. These results indicate that ultrasonic vibration can effectively reduce residual stresses and suppress part spring-back. These results are attributed to the fact that ultrasonic vibration changes the forming mechanism and improves the plasticity and ductility of the metal, which are of great significance with respect to part quality and accuracy improvements. [ABSTRACT FROM AUTHOR]

In this paper, the effects of ultrasonic vibration and powder mixed on Electrical Discharge Machining (EDM) are investigated. Based on the heat transfer theory, an ultrasonic powder mixed EDM (US-PMEDM) heat transfer model combining ultrasonic vibration and powder mixed characteristics is established, and the heat transfer model carries out a transient thermodynamic simulation for the process of removing the material during the EDM process, and through the experimental and simulation analysis of four kinds of EDM, powder mixed EDM (PMEDM), ultrasonic (UEDM), and US-PMEDM, the accuracy of the simulation is verified. The accuracy of the simulation was verified by observing the surface morphology after machining. The material removal process was analyzed under different machining methods and different concentrations of powder mixed particles. Under the processing conditions of fixed processing current of 2A, ultrasonic amplitude of 5 µm, and powder concentration of 2g/L, the material removal rate (MRR) of the PMEDM method was increased by about 26.3% and the surface roughness (SR) was reduced by 7.78% compared with that of the EDM method, and the material removal rate of the US-PMEDM method was increased by about 49.4% and the surface roughness was increased by 4.05% compared with that of the EDM method. The surface quality can be improved by adding powder mixing, and the surface quality of powder mixing is better than that of ultrasonic vibration. [ABSTRACT FROM AUTHOR]

This study aims to clarify the combined effect of ultrasonic melt treatment (UST), hot rolling and solution aging (HRSA) on the evolution of the Al2Cu secondary phase in 2219 Al alloy toward the optimization of its mechanical properties for high‐performance structural applications. The results show that UST is beneficial for modifying the morphology and reducing the size of the secondary phase (by an average of 17.9%), and conducive to increasing the Cu content in the Al matrix (by an average of 37.5%) during solidification. The genetic effects of UST on the microstructure generated during HRSA result in denser and finer θ′/θ″ Al2Cu particles precipitating in the α‐Al matrix, with a 62.1% increase in the precipitates volume in the HRSA sample. Theoretical calculations confirm that precipitation strengthening is the predominant mechanism for strength improvement of 2219 Al alloy after UST and HRSA. The ultimate tensile strength (UTS), yield strength (YS), and elongation (EL) of the HRSA alloy without UST are 329, 214 MPa, and 11.9%, respectively, while these parameters are increased by 12.5% (to 370 MPa), 9.8% (to 235 MPa), and 17.6% (to 14.0%) for the UST alloy, respectively. [ABSTRACT FROM AUTHOR]

Since animal meat has been a major source of protein, conventional livestock farming is ever-increasing, as the global population grows. But the livestock farming has caused serious resource and environmental issues in recent years, such as greenhouse gas emissions, land occupation, water consumption, and loss of biodiversity. Alternatively, plant protein meat (PPM) can be expected to serve as the animal meat analogue, in order to alleviate the shortage of animal meat, resource consumption, and environmental pollution. The primary processing techniques for PPM currently include extrusion, spinning, shearing, and 3D printing. Specifically, the emerging 3D printing has been successfully applied to PPM production in the food industry, thus enabling customization of nutritional content, shape, texture, and flavor. Previous studies of 3D-printed PPM have focused primarily on material formulations, process parameters, or nozzle structures in conventional 3D printing. Among them, ultrasonic vibration has been used to print highly viscous fluid materials in protein extraction, gelation, and food processing. Better performance has also been achieved to mitigate the clogging caused by small nozzle diameters or high material viscosity. However, it is still lacking in the application of ultrasonic vibration for the high quality of 3D-printed PPM. In this study, ultrasonic vibration was introduced to improve the quality of 3D-printed PPM. A systematic analysis was made to explore the mechanism of ultrasonic vibration on plant proteins. Rheological property tests and numerical simulations of 3D printing nozzles were then carried out to investigate the effect of ultrasonic vibration on the gelation of plant proteins. A novel ultrasonic vibration-assisted 3D printing system was developed for PPM using single-nozzle 3D printing. A series of experiments were conducted to clarify the influence of ultrasonic vibration on the quality of 3D-printed PPM. The numerical simulation results demonstrated there was a cyclic variation in the fluid velocity inside the printing nozzle, with the trend of increasing, decreasing, and then increasing for the uniform mixing of protein molecules. Additionally, the shear rate within the nozzle exhibited repetitive fluctuations with decreasing and then increasing, where relatively high shear rates were observed on both the surface and cross-sections of the fluid. A high-shear environment was provided for the stepwise depolymerization of protein molecules during printing. The internal fluid pressure within the nozzle also showed a cyclic variation in the decreasing and then increasing. The lowest pressure value was still higher than that in the absence of ultrasonic vibration. This fluctuation of pressure greatly contributed to the necessary conditions for the depolymerization of protein molecules. Thus, the ultrasonic vibration supplied the higher shear and pressure to the plant proteins during 3D printing. The gelation process was promoted to ultimately improve the molding quality of 3D-printed PPM products. Experimental results revealed that the printed products exhibited decreased hardness, comparable elasticity, and chewiness after ultrasonic vibration, compared with conventional 3D printing. In terms of the stability of hardness, elasticity, and chewiness, the fluctuations in these quality parameters were lower than those in the samples printed without ultrasonic vibration. Specifically, the stability of hardness, elasticity, and chewiness increased by 27.75%, 83.14%, and 59.30%, respectively, indicating a more consistent quality for the samples printed with ultrasonic vibration. The ultrasonic vibration was incorporated into the 3D printing of PPM for the stability of quality attributes. The finding can also provide valuable insights into producing high-quality plant-based protein meat using 3D printing. [ABSTRACT FROM AUTHOR]

(1) Background: The main aim of this study was to investigate the effects of different cements (Panavia V5, RelyX U200) and placement techniques (indirect ultrasonic vibration and manual method) on the bond strength of glass fiber posts in teeth with different post space preparation methods and to evaluate the failure types. (2) Methods: A total of 120 human upper central teeth were collected for the study. One week after root canal treatment, 10 mm long post space preparation was performed using post drills. Post spaces were irrigated in three different ways, namely NaOCl, NaOCl + EDTA solutions, and passive ultrasonic irrigation of NaOCl and EDTA solutions. Glass fiber posts were divided into two groups for resin cement systems, namely RelyX U200 (3M ESPE) or Panavia V5 (Kuraray Medical). Two different methods, namely the indirect ultrasonic vibration and the manual method, were applied for post placement. Then, 1.2 mm sections were taken from the middle and coronal regions of the inserted fiber posts for a push-out test. (3) Results: the Irrigation × Cement (p = 0.002), Cement × Section (p = 0.043) and Placement × Section (p = 0.049) pairwise interactions were statistically significant. (4) Conclusions: in our study, the effects of different post cavity preparations, different cement types, and different placement techniques on the bond strength of the fiber post were observed. [ABSTRACT FROM AUTHOR]

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Mg-9 Al-1 Si alloy was prepared by gravity casting of copper metal mo Id, and the microstructure of the alloy was controlled by ultrasonic treatment at different time before solidification. The evolution of microstructure and morphology and its effect on mechanical properties of Mg-9Al-1Si alloy under ditferent ultrasonic treatment time were characterized by means of OM, XRD, SEM and tensile test. The results show that without ultras-onic treatment, crMg matrix is coarse dendrite, coarse Chinese character-like Mg2Si phase has obvious agglomeration, β-Mg17Al12 phase is intermittently reticulated along the dendrite boundary, ultrasonic treatment can significantly refine the micro structure of the aloy, the grain size of c-Mg matrix changes from coarse dendritic to flocculent andthe Chinese character Mg2Si phase is refined into strip or thin line, and the distribution becomes uniform. The reticular trend of &#946-Mg17Al12 phase weakens, and a large number of lamellar &#946-Mg17Al2 phases appear at the boundary. With the increase of ultrasonic time, the effect of ultrasonic cavitation and sound flow can obviously improve the microstructure of the alloy, but the effect of ultrasonic cavitation and acoustic flow on microstructure refinement is weakened for too long. Therefore, the mechanical properties of Mg-9Al-1Si alloy were significantly improved after ultrasonic treatment, and increased at first and then decreased with ultrasonic treatment time, in which the improvement of ultrasonic treatment of 20 min was the highest, which was 72,74 MPa and 2. 31% higher than that of untreted aloy respecively. [ABSTRACT FROM AUTHOR]

In the past five years, the number of articles related to ultrasonic mineral flotation has increased by about 50 per year, and the overall trend is on the rise. The most recent developments in ultrasonics for flotation process intensification are reviewed herein, including effects of ultrasound treatment on an aqueous slurry, improvement in flotation methods and technological processes, device development tracking, and application effects in mineral process engineering. At this point in time, there are pilot-scale flotation tests to evaluate the feasibility of ultrasonic pretreatment technology for industrial use to enhance residue flotation separation, and the results showed that the recovery rate of concentrate is increased by about 10%. Four aspects of ultrasonic flotation process improvement are summarized, namely, changing the ultrasonic parameters, the synergistic effect of ultrasound and reagents, the ultrasonic effect of particles with different-sized fractions, and application to new systems. In addition, the effect of ultrasonic flotation mechanisms is explored through a quadratic model and numerical simulation. The combination of ultrasonic flotation with other fields, such as magnetic fields, to enhance the separation efficiency and recovery of minerals is also a future trend. It is also proposed that ultrasonic flotation technology will be used with big data, industrial Internet of Things, and automatic control technology to achieve deep bundling, optimizing the flotation process by implementing remote monitoring and control of the flotation process. [ABSTRACT FROM AUTHOR]

Heavy metal ions and antibiotic contamination have become a major environmental concern worldwide. The development of efficient recognition strategies of these pollutants at ultra‐low concentrations in aqueous solutions as well as the elucidation of the intrinsic sensing mechanism are challenging tasks. In this work, unique luminescent Ln‐MOF materials (NIIC‐3‐Ln) were assembled by rational ligand design. Among them, NIIC‐3‐Tb demonstrated highly selective luminescence quenching response toward Hg2+ and sulfadiazine (SDI) at subnanomolar concentrations in less than 7 s. In addition, a Hg2+ sensing mechanism through chelation was proposed on the basis of single‐crystal X‐ray diffraction analysis and Hg2+ adsorption study. The interaction mechanism of NIIC‐3‐Tb with SDI was revealed using a newly developed approach involving a (TD‐)DFT based quantification of the charge transfer of a MOF‐analyte supramolecular complex model in the ground and excited states. Effect of ultrasonic treatment on the surface morphology important for MOF sensing performance was revealed by gas adsorption experiments. The presented results indicate that NIIC‐3‐Ln is not only an advanced sensing material for the efficient detection of Hg2+ and SDI at ultra‐low concentrations, but also opens up a new approach to study the sensing mechanism at the molecular level at ultra‐low concentrations. [ABSTRACT FROM AUTHOR]

Crop damage and vehicle collisions caused by wild ungulates require effective deterrents. Many commercial acoustic devices use ultrasonic signals, presenting them as aversive to these animals. However, unconvincing results reported in previous studies using (non-frequency modulated) ultrasounds bring their effectiveness as deterrent signals into question. Here, we explored the deterrent effectiveness of ultrasounds in several large mammalian species that are expected to perceive these high frequencies. Specifically, we tested the effect of different ultrasonic signals on red deer, peccaries, and wolves. Animals were exposed to sequences of nine acoustic signals in the 20–30 kHz frequency range, and to a lower-pitched signal (2–3 kHz). While red deer showed no aversion to ultrasonic signals (inaudible for humans), lower frequency (audible for humans) modulations increased aversive responses. Conversely, peccaries showed strong flight responses to several ultrasonic signals. Wolves also reacted to ultrasounds but did not flee. Our study confirms that ultrasonic signals are not suitable for deterring European red deer. However, our results suggest that their effectiveness in other species should be systematically tested, without assuming that their hearing frequency range is a reliable predictor of their behavioural responses to ultrasonic signals. [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]

In this paper, the influence mechanism of ultrasound on plastic flow and microstructure features of the aluminum–copper friction stir lap welding (Al/Cu-FSLW) process is systematically investigated by adjusting the welding speed and improving the shear rheology in the plastic stirring zone. Through adjusting the ultrasonic vibration and welding speed, the directional control of mechanical properties is realized. It is found that increasing the welding speed properly is beneficial to enhance the mechanical shear between the tool and the workpiece, thus forming more staggered layered structures at the copper side and improving the tensile strength of the weld. The acoustic softening enhances the viscoplastic fluid mixing and strengthens the mechanical interlock of the Al/Cu lap interface. As the welding speeds increase or ultrasonic vibration is applied, the thickness of Al/Cu intermetallic compound (IMC) decreases, and the tensile strength and elongation of the Al/Cu joints are enhanced. Compared with adjusting the welding speed, the ultrasonic vibration can further refine the copper particles which are stirred into the plastic zone, and the thinning effect of ultrasound on IMC layers is better than that of increasing welding speed. At the welding speed of 60 mm/min, the IMC layer thickness is reduced by 42% under ultrasonic effect. In three welding speed conditions, the UV reduced the absolute value of the effective heat of formation (EHF) for Al2Cu and Al4Cu9 and suppressed the formation of AlCu phase. Meanwhile, only when the welding speed is increased from 60 mm/min to 100 mm/min can the formation of AlCu be suppressed. Under the ultrasonic optimization, the stable improvement of welding efficiency is ensured. [ABSTRACT FROM AUTHOR]

This study involved the ultrasonic modification of water-soluble pectin, chelator-soluble pectin, and sodium carbonate-soluble pectin in blueberries using different ultrasonic treatments (688, 1376, 2063 W/cm2, 10, 20, 30 min). The research explored the relationship between the modified pectin structure and the interaction between pectin and cyanidin-3-O-glucoside (C3G). The results showed that ultrasonic modification resulted in enhanced interaction between pectin and C3G. After the ultrasonic treatment of 2063 W/cm2 for 10 min, all three pectins showed the maximum binding capacity with C3G, which was about 2~6 times higher than that without the ultrasonic modification. Whereas, prolonged ultrasonic time (20~30 min) was unfavorable for the interaction between modified pectin and C3G. After ultrasonic modification, the particle size of the pectin-C3G complexes became smaller, the Zeta potential was increased, and the physical stability was thus improved. In three different pectin samples, ultrasonic treatment induced a reduction in molecular weight and methyl esterification of the pectin, facilitated the degradation of the branched structures, promoted the number of free carboxyl groups, and increased the presence of structural network voids. The alteration of the structural properties of pectin by ultrasonic treatment facilitated the interactions between pectin and C3G. [ABSTRACT FROM AUTHOR]

The acoustic catalytic degradation of methylene blue (MB) was studied using silicon carbide (SiC) nanowires and commercial TiO2 (P-25). SEM images show that the average diameter of SiC nanowires is less than 500 nm and the length is up to tens of microns. XRD patterns and FTIR spectra confirmed the high purity of SiC in the catalyst. The catalytic performance of the two catalysts is better under alkaline conditions. The Kapp values (pseudo-first-order kinetics) of the synergistic effects of ultrasonic treatment and adsorption processes using SiC and TiO2 are 1.36 and 1.31 times the sum of the Kapp values of the two separate processes, respectively. This finding indicates that acoustic catalysis can improve the photocatalytic performance of SiC and TiO2 on MB. Compared with TiO2, SiC nanowires exhibit better acoustic catalytic performance, and hydroxyl radicals are more significant in the acoustic catalytic degradation of SiC to MB. Meanwhile, hydroxyl radicals play a leading role in the degradation process of MB. [ABSTRACT FROM AUTHOR]

This study elucidates the impact of fluctuating influent conditions and in situ ultrasonic wave exposure on the stability of aerobic granular sludge (AGS) in the treatment of simulated wastewater emanating from rare earth mining operations. During a stable influent period spanning from Day 1 to Day 95, the seed granules underwent an initial disintegration followed by a re-granulation phase. The secondary granulation was achieved on Day 80 and Day 40 for the ultrasonic reactor (R1) and the control reactor (R2), respectively. Notably, granules formed in R1 exhibited a more porous structure compared to those generated in R2. Subsequently, when the ammonia nitrogen in the influent oscillated between 100 and 500 mg/L during Days 96-140, both reactors yielded compact and densely structured granules. Nitrogen removal profiles were comparable between the two reactors: the removal efficiencies for ammonia nitrogen and total inorganic nitrogen escalated from 95% and 80%, respectively, during Days 1-95, to 95% and 90%, respectively, post-Day 140. A suite of performance metrics indicated that steady-state granules from R1 outperformed those from R2 across several parameters. Specifically, the nitrification/denitrification rates, and relative abundance of denitrifying bacteria were all higher in granules from R1. Conversely, the relative abundance of nitrifying bacteria was comparable between granules from both reactors. However, R1 granules demonstrated lower sludge concentration and smaller average particle size than their R2 counterparts. In conclusion, the AGS system demonstrated robust resilience to fluctuating ammonia nitrogen, and the application of ultrasonic waves significantly enhanced granular activity while achieving in situ sludge reduction. [ABSTRACT FROM AUTHOR]

Thin-walled carbon/carbon (C/C) composites are a typical difficult-to-machine material due to the characteristics of thin walls, low stiffness, and high strength. In this paper, three ultrasonic-assisted machining methods and surface morphology of C/C composite thin-walled small holes were studied. The influence of machining parameters on average axial force and hole surface morphology was explored by single-factor experiments and orthogonal experiments. A quantitative comparison was conducted to evaluate the machining defects of drilling, reaming, and grinding. The results of single-factor experiments showed that the surface quality of drilling initially improved and then deteriorated with the increase of spindle speed. Additionally, increasing feed rate resulted in a deterioration in surface quality, while increasing amplitude to a certain extent led to an improvement. In orthogonal experiments, the effect of ultrasonic amplitude on the average axial force of reaming and grinding was greater than that of drilling. In terms of surface quality, the minimum evaluation factor Qc of the grinding, reaming, and drilling could reach 1.0137, 1.0198, and 1.0253, respectively. Further optimized by a multivariate optimization function, the optimal parameters of grinding were obtained as the speed of 6200 r/min, feed rate of 40 mm/min, and amplitude of 8 μm and the minimum values of Qc could reach 1.0128. [ABSTRACT FROM AUTHOR]

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Surface properties directly affect the service life of heavy rail. The effect of ultrasonic impact energy and head shape on surface hardness, residual stress, morphology of heavy rail was investigated in this paper. 15 different impact processes and three impact head shapes of bar, single-pin head, and three-pin head were designed to treat the heavy rail surface by ultrasonic impact. The results showed that under three-pin head impact, the hardness of the ultrasonic impact area was 24.4% higher than the initial hardness at the process of 2.0 A, 60 s, and the minimum surface residual stress was − 642 MPa in the 2.5 A, 90 s. Finite element results indicated that the UIT (ultrasonic impact treatment) introduced beneficial compressive stress up to the depths of 1-3 mm. After ultrasonic impact treatment, the microscopic morphology of the heavy rail changed, resulting in a deformation of up to 1047.9 μm and a white layer. [ABSTRACT FROM AUTHOR]

The pore structure of coal plays a key role in the effectiveness of gas extraction. Conventional hydraulic fracturing techniques have limited success in modifying the pore structure using clean fracturing fluid (CFF), and the stimulating effects of ultrasonic can enhance the effectiveness of CFF in modifying coal pore structures. To research the effects of ultrasonic stimulation on the pore structure of medium to high-rank coal when using CFF, this study employed mercury intrusion porosimetry (MIP) and low-temperature nitrogen adsorption (LT-N2A) methods to analyze the changes in pore structures after cooperative modification. The results indicate that the pore volume and surface area of medium to high rank coal exhibit an increase and followed by a decrease with increasing Ro,max values, while the average pore diameter and permeability demonstrate a decrease and followed by an increase with Ro,max. Although there are some variations in the results of MIP and LT-N2A analysis for different pore size ranges, the overall findings suggest that ultrasonic stimulation in conjunction with CFF effectively alters the coal pore structure. The most significant improvement was observed in coking coal, where pore volume increased by 22%, pore area decreased by 11% and tortuosity decreased by 47%. The improvement of lean coal is the smallest, the pore volume increases by about 7%, and the surface area decreases by about 14%. It is found that the modification of coal pore volume is mainly concentrated in transition pores and macropores. These research outcomes provide valuable insights into the application of ultrasonic technology in coalbed gas extraction. [ABSTRACT FROM AUTHOR]

In this work, a new treatment method combining ultrasonic vibration with FeCoNiCrCu high entropy alloy (HEA) coating was used to prepared Al/Mg bimetal through the lost foam compound casting. The effects of composite treatment involving ultrasonic vibration and HEA coating on interfacial microstructure and mechanical properties of Al/Mg bimetal were studied. Results demonstrate that the interface thickness of the Al/Mg bimetal with composite treatment significantly decreases to only 26.99% of the thickness observed in the untreated Al/Mg bimetal. The HEA coating hinders the diffusion between Al and Mg, resulting the significant reduction in Al/Mg intermetallic compounds in the interface. The Al/Mg bimetal interface with composite treatment is composed of Al3Mg2 and Mg2Si/AlxFeCoNiCrCu+FeCoNiCrCu/δ-Mg+Al12Mg17 eutectic structures. The interface resulting from the composite treatment has a lower hardness than that without treatment. The acoustic cavitation and acoustic streaming effects generated by ultrasonic vibration promote the diffusion of Al elements within the HEA coating, resulting in a significant improvement in the metallurgical bonding quality on the Mg side. The fracture position shifts from the Mg side of the Al/Mg bimetal only with HEA coating to the Al side with composite treatment. The shear strength of the Al/Mg bimetal increases from 32.16 MPa without treatment to 63.44 MPa with ultrasonic vibration and HEA coating, increasing by 97.26%. [ABSTRACT FROM AUTHOR]

Plasma spray is a promising technology for surface protection and modification in many industrial application fields. However, the low adhesive or cohesive strength of the plasma sprayed coatings limited their further application. The cohesive strength was enhanced 115% ultra-sonicating the substrate during the plasma spraying process of Ni-10wt.%Al coatings. With the increase of power density from 0 to 1.32 W/cm2, the porosity, residual stress and strain were all decreased. However, when the power was further increased to 2.20 W/cm2, the porosity, residual stress and strain were all increased. Ultrasonic energy and the ultrasonic effects of acoustic pressure, acoustic streaming, heat effect, and cavitation effect would affect the physical processes of wetting, filling and solidification of the molten droplets during the plasma spraying process, affecting the microstructure and cohesive strength of the plasma sprayed coatings. The ultrasonic energy and ultrasonic effects which are affected by the ultrasonic power density affecting the fundamental physical processes is the key to enhance the cohesive strength of the plasma sprayed coatings. [ABSTRACT FROM AUTHOR]

The recent advances in the green-based design and synthesis of core-shell nanostructures have always been an intriguing arena to scientists due to their compelling application in catalytic fields. This work designed and synthesized a new core-shell nanosphere based on Fe3O4 as a novel, heterogeneous, reusable, efficient, and green catalyst to synthesize benzothiazole derivatives under ultrasonic irradiation. To achieve this goal, initially, fabricated Fe3O4 magnetic nanoparticles via the co-operation method were synthesized as a core, followed by coating with polyethylene glycol (PEG-400). Subsequently, Ni@Murexide complex supported on magnetic nanoparticles is successfully synthesized and reported, modified using 3-chloropropyltriethoxysilane (CPTES) and Murexide (MX) ligand in the Fe3O4@PEG support. The obtained structure of Fe3O4@PEG/MX/Ni was characterized by different analyses such as FT-IR, SEM, EDS, TEM, ICP-OES, XRD, VSM, and TGA. The results illustrated the effect of ultrasonic irradiation and the high efficacy of Murexide as a ligand in catalyzing the formation of benzothiazole derivatives and confirming the findings from the reaction of different derivatives of aromatic aldehyde with electron-withdrawing/donor groups with 2-amino thiophenol through a one-pot process in 10 min under ultrasonic irradiation which shows the non-sensitivity of the process to electronic effects. Furthermore, Fe3O4@PEG/MX@Ni showed great use at least six times with no significant loss in catalyst activity. [ABSTRACT FROM AUTHOR]

Ultrasonic-assisted forming process is one of the important methods to improve the formability of materials because of its acoustic softening effect and antifriction effect. After the introduction of ultrasonic, the forming accuracy of the inner ribs is improved in the spinning process of ribbed cylindrical parts, but the effect law of ultrasonic energy on the forming of inner ribs has not been clarified in detail. In this paper, a modeling method of ultrasonic-assisted spinning was proposed, which was taken into account the attenuation characteristics of ultrasonic energy in solid media for the improvement of the simulation accuracy. The corresponding simulation model was established to explore the effect law of ultrasonic amplitude on the forming accuracy of inner ribs. The results showed that the forming height and surface morphology of longitudinal ribs can be improved effectively in the ultrasonic-assisted spinning process. With the increase of ultrasonic amplitude, the forming height of longitudinal rib gradually increased, but the increase degree of the rib height gradually slowed down, and the difference of the material filling between the screw-in end and the screw-out end at the rib groove gradually decreased, but the surface morphology of the longitudinal ribs always present the geometric characteristics that the screw-in end is higher than the screw-out end. The reason is that the application of ultrasonic vibration promoted the radial and circumferential flow of the material and improved the material filling ability into the rib groove. The combined effect of ultrasonic softening effect and anti-friction effect reduced the radial filling difference between the screw-in end and the screw-out end of the ribs. Ultrasonic vibration could enhance the material flow but did not significant change the forming distribution characteristics of the ribs, resulting in limited rib height and uneven surface morphology. Also, the energy field gradient design method along the sheet thickness was proposed to further improve the forming accuracy of the inner ribs. [ABSTRACT FROM AUTHOR]

Proteins are widely consumed for their nutritional benefits, and they possess many applications such as emulsifiers, foaming agents, fat replacers, and thickeners which aid in obtaining the desired rheology and texture of food products. Moreover, the formation of protein–carbohydrate complex can further enhance the functional properties. Hence, the present study investigated the effect of ultrasonic cavitation in the formation of soy protein-rice starch complexes. Ultrasound treatment at 60% amplitude (450 W) combined with heat treatment formed complexes with enhanced solubility, water holding, and foaming properties compared to raw soy protein isolates. Further, sonication preserved the crystalline nature of the complexes formed. The molecular docking studies performed using 11 S protein (1FXZ) indicate the formation of the hydrogen bonds of shorter distances between glutamine (GLN) and leucine (LEU) amino acids with the OH group of rice starch. The complexes formed had excellent functional properties, which increased their scope of application in the food industry. [ABSTRACT FROM AUTHOR]

This study reports the preparation of ZnCo 2 O 4 oxide (ZCO) electrode materials with favorable microstructure and porosity arrangement via ultrasonic electrodeposition-calcination. The application of ultrasonic waves at a power of 200 W (using ZCO-2) led to the development of a smooth and flat microstructure, characterized by the presence of numerous micropores. The lattice constant of ZnCo 2 O 4 in the ZCO-2 oxide electrode material was determined to be 0.428 nm via TEM analysis. Furthermore, the XRD analysis of ZCOs demonstrated the effective synthesis of ZnCo 2 O 4 electrode materials. The main lattice diffraction planes of ZCOs were observed at (111), (220), (311), (400), (511), and (440), with corresponding diffraction angles of 29.8°, 36.4°, 42.9°, 45.2°, 62.3°, and 66.5°, respectively. The application of 200 W ultrasonic power during electrochemical experiments significantly improved the electrochemical performance of ZCO-2. The ZCO-2 oxide electrode demonstrated remarkable area capacitance and negligible electrical impedance. At a current density of 3 mA/cm2, the area capacitance was measured to be 1.803 F/cm2. The ZCO-2 oxide electrode showed remarkable capacitance retention of 67.3 % even under high current density conditions. Furthermore, the asymmetric supercapacitor composed of ZCO-2 and AC (ZCO-2/AC ASC) showed outstanding electrochemical performance. The ZCO-2/AC ASC showed a capacitance of 5.721 F/cm3 at a current density of 0.5 mA/cm2. Furthermore, it demonstrated an energy density of 68.2 Wh/kg at a power density of 250 W/kg. The capacitor showed consistent performance and retained 63.8 % of its initial capacitance even after undergoing 24,000 cycles. Furthermore, the findings of this research provide substantial implications for the combination of ultrasonic electrodeposition with capacitors, while also presenting an innovative concept for electrode materials in high-performance supercapacitors. [ABSTRACT FROM AUTHOR]

This study analyzes the influence of different ultrasonic amplitudes on the microstructure composition, microhardness, tensile strength, and corrosion resistance of Al alloy/steel laser welding-brazing joints assisted by ultrasonic vibration. The application of ultrasonic vibration did not change the microstructure composition of the joints but refined them. The joints were all composed of θ-Fe(Al, Si)3 and τ5-Al7.2Fe1.8Si formed at the interface reaction zone, as well as an α-Al solid solution and Al-Si eutectic phase generated in the weld seam zone. Meanwhile, the thickness of the IMCs at the interface decreased with an increase in the ultrasonic amplitude. When the ultrasonic amplitude was 8 μm, the IMCs thickness was a minimum of 1.62 μm. In this condition, the reduction of the IMCs thickness and the refined grain of joints made the microhardness and tensile strength reach the maximum. The fracture of joints with ultrasonic amplitudes of 0 and 4.8 μm began at the weld seam and extended to the interface reaction zone at the steel side, while the fracture of joints was located in the heat-affected zone (HAZ) of the Al alloy side when the ultrasonic amplitude was 8.0 and 11.2 μm. The fracture mode of the former presented a typical mixed fracture with cleavage steps and tearing edges, and that of the latter showed ductile fracture with uniform and fine ductile dimples. The corrosion resistance of the joints was improved by adding ultrasonic vibration. When the ultrasonic amplitude was 8 μm, its corrosion resistance was optimum; it was ascribed to a dense oxide film formed on the surface of the metal under the action of ultrasonic vibration. [ABSTRACT FROM AUTHOR]

Tunnel boring machines (TBMs) are exposed to the impact of the ground shattering force and the friction of sandstone during excavation work, and are prone to wear and breakage, and other failures. Traditional heat treatment processes cannot simultaneously achieve the required high-energy composite structure of hard external and tough internal properties for cutter rings, leading to inadequate wear resistance and impact toughness under working conditions. This study utilizes H13 steel as the base material, and based on a study of carburizing, nitriding, and ultrasonic impact processes for H13 steel analyzing the effects of different high-energy composite modification processes on the hardness distribution, microstructure, and residual stress of H13 steel, the mechanisms by which high-energy composite modification processes affect the wear resistance and impact resistance of H13 steel are revealed. The results indicate that the wear amount and impact toughness of the sample subjected to carburizing and ultrasonic surface rolling composite strengthening were 1.9 mg and 27.34 J/cm2, demonstrating the best wear and impact resistance. This combination of properties allows the H13 steel cutter ring to achieve the optimal overall performance in terms of wear resistance and impact resistance. [ABSTRACT FROM AUTHOR]

Based on the self-made electric pulse-ultrasonic assisted incremental forming platform, the incremental forming experiments of AZ31B Mg alloy were achieved. The results showed that both increasing the current density and raising the current frequency could elevate the forming temperature. Moreover, with appropriate current parameters, the fracture height exceeded 6 mm, which was more than 240% higher compared to the workpiece without energy field assistance. Comparatively, the softening effect of ultrasonic vibration on the sheets was most pronounced when the current frequency and density were 400 Hz with 29.8 A/mm2 and 350 Hz with 31.3 A/mm2, and the softening effect mainly results from the promotion effect of ultrasound on the dynamic recrystallization of Mg alloy during the incremental forming process. [ABSTRACT FROM AUTHOR]

Transcranial ultrasonic stimulation (TUS) is rapidly emerging as a promising non-invasive neuromodulation technique. TUS is already well-established in animal models, providing foundations to now optimize neuromodulatory efficacy for human applications. Across multiple studies, one promising protocol, pulsed at 1000 Hz, has consistently resulted in motor cortical inhibition in humans (Fomenko et al., 2020). At the same time, a parallel research line has highlighted the potentially confounding influence of peripheral auditory stimulation arising from TUS pulsing at audible frequencies. In this study, we disentangle direct neuromodulatory and indirect auditory contributions to motor inhibitory effects of TUS. To this end, we include tightly matched control conditions across four experiments, one preregistered, conducted independently at three institutions. We employed a combined transcranial ultrasonic and magnetic stimulation paradigm, where TMS-elicited motor-evoked potentials (MEPs) served as an index of corticospinal excitability. First, we replicated motor inhibitory effects of TUS but showed through both tight controls and manipulation of stimulation intensity, duration, and auditory masking conditions that this inhibition was driven by peripheral auditory stimulation, not direct neuromodulation. Furthermore, we consider neuromodulation beyond driving overall excitation/inhibition and show preliminary evidence of how TUS might interact with ongoing neural dynamics instead. Primarily, this study highlights the substantial shortcomings in accounting for the auditory confound in prior TUS-TMS work where only a flip-over sham and no active control was used. The field must critically reevaluate previous findings given the demonstrated impact of peripheral confounds. Furthermore, rigorous experimental design via (in) active control conditions is required to make substantiated claims in future TUS studies. Only when direct effects are disentangled from those driven by peripheral confounds can TUS fully realize its potential for research and clinical applications. [ABSTRACT FROM AUTHOR]

Friction stir welding (FSW) and ultrasonic vibration enhanced FSW (UVeFSW) experiments were conducted by using 6061-T6 Al alloy and AZ31B-H24 Mg alloy sheets of thickness 2 mm. The suitable process parameters windows were obtained for the butt joining of Al/Mg sheets. The effect of ultrasonic vibration on the macrostructure and mechanical properties of the dissimilar joints was studied. The results showed that the width of the weld nugget zone (WNZ) was enlarged to some extent and the hardness distribution in WNZ was more uniform in UVeFSW. In addition, the application of ultrasonic vibration effectively promoted the interpenetration degree of dissimilar materials in the WNZ so that the mechanical interlocking on the bonding interface of dissimilar Al/Mg materials was enhanced. The facture positions were changed from the bonding interface in FSW to the boundary between WNZ and the thermo-mechanical affected zone, and the ductile fracture zone was expanded. The highest ultimate tensile strength was 205 MPa at the process parameters set of 1200 rpm–50 mm/min in UVeFSW in this experiment. The average ultimate tensile strength of FSW/UVeFSW joints was 172.3 MPa and 184.4 MPa, respectively, and the average ultimate tensile strength was increased by 7.02% with the introduction of ultrasonic vibration. [ABSTRACT FROM AUTHOR]

In alkaline water electrolysis, gas bubble coverage of the electrode surface is directly linked with an increase in cell potential. Ultrasonic field presence in water electrolysis has been proven effective in removing gas bubbles from the electrode and enhancing mass transfer and bubble removal. Most studies regarding water electrolysis under sonification focused on low-concentration NaOH electrolyte solutions so there is a lack of information regarding operating conditions similar to commercial solutions. This work focused on an experimental evaluation of the effect of an ultrasonic field with a 40 kHz frequency on water electrolysis using a lab-scale electrolyser with three different KOH solutions varying in concentration (15, 25, 35% (w/w)) at 30, 40, 50, 60 °C. A reduction in cell potential was registered across all test conditions and it was maximum for 15 and 25% KOH solutions at 30 °C with 52 and 34 mV, respectively, and decreased with an increase in temperature. For a 35% KOH solution, the cell potential reduction stayed constant across all temperatures (16–19 mV). This difference was thought to be caused by the ultrasonic frequency and power and therefore required further testing. To further investigate the effect of gas bubble accumulation on the electrode surface, measurements of hydrogen bubbles' critical diameter were taken. It was found that a higher electrolyte concentration results in a lower critical diameter (0.404, 0.356, and 0.293 mm with a 15, 25, and 35% KOH, respectively) assumed to be a consequence of higher viscosity and gas formation rate at higher concentrations. • Effect of ultrasonic field is studied in water alkaline electrolysis. • Three KOH solutions varying in concentration (15, 25, 35% (w/w)) at 30, 40, 50, 60 °C were tested. • A reduction in overpotential was registered across all test conditions. • Overpotential was observed to decrease with increasing temperatures. • Ultrasonic field is effective removing gas bubbles from the electrode and enhancing mass transfer and bubble removal. [ABSTRACT FROM AUTHOR]

This study optimized the extraction process of Chlorella protein using response surface methodology and characterized its secondary structure. With the protein solubility rate of Chlorella as the indicator, the effects of ultrasonic power, ultrasonic time, NaOH mass fraction, and water bath time on the extraction rate were investigated. Based on the Plackett-Burman design, a four-factor three-level response surface analysis was conducted to determine the extraction process of Chlorella protein. The results showed that the optimal extraction conditions for Chlorella protein were ultrasonic power of 460.08 W, ultrasonic time of 16.05 min, NaOH mass fraction of 14.03%, and water bath time of 37.18 min, with a solubility rate of 87.64%. The extracted Chlorella protein was purified using isoelectric focusing under optimal conditions and then subjected to FTIR analysis, microscopic structure analysis, and amino acid analysis. The results indicated that the secondary structure of Chlorella protein mainly consisted of β-sheet, accounting for 30.00% of the total content. The microscopic structure revealed a smooth surface with pore structures, and it contained five essential amino acids, accounting for 42.71% of the total content. In conclusion, the ultrasonic-assisted alkaline method demonstrates significantly improved protein wall-breaking efficiency and high protein extraction rate for Chlorella, with simple operation and low cost. It has promising prospects for industrial applications and provides relevant references for the food application of Chlorella protein. [ABSTRACT FROM AUTHOR]

Ultrasonic flotation is widely used as an efficient mineral separation method. Its efficiency is related to the adhesion behavior between fine particles and flotation bubbles, which can be influenced by the bubbles' movement behavior. This paper used two immersed ultrasonic vibration plates to generate ultrasonic action and investigated the effect of ultrasonic action on the rising process of flotation bubbles. The distribution, aggregation and fusion, velocity, and other characteristics of bubbles generated by different needle apertures were studied by experimental and simulation methods. The results showed that a 0.4 mm needle produced bubbles that were more evenly spaced and more uniform in size and shape. The ultrasonic action can make the bubbles aggregate together and reduce the bubble rise velocity, as well as prolong their time in the flotation process at the same time. It is beneficial to the sufficient collision and adhesion behavior between flotation bubbles and particles, eventually improving the efficiency of mineral flotation. [ABSTRACT FROM AUTHOR]

The current research aims to study the ultrasound assisted intensification of activity of commonly applied amylase enzyme, under varying parameters like power, frequency, duty cycle, temperature and enzyme concentration. Two ultrasonic reactor configurations as bath and horn are used for comparing the efficacy of reactor configuration. The initial activity of native amylase was found as 5.77 U/g at optimum temperature of 35° C and pH 7. Under US bath treatment, α amylase attained maximum activity of 7.498 U/g at best treatment conditions of 120 W power, 30% duty cycle and 15 minutes of exposure time. In the case of US horn, application of 60 W power, 30% duty cycle, and 5 minutes of exposure increased the enzyme activity to 6.907 U/ g. Set of treatment approaches explored for obtaining highest yield of reducing sugars revealed the best approach of ultrasonic treatment of food waste followed by ultrasonic bath intensified amylase hydrolysis, yielding maximum amount of reducing sugars as 8.14 g/L in only 15 min. Overall the work elucidated the role of ultrasound in intensifying the enzyme activity as well as food waste hydrolysis maximizing the utilization of sustainable resource. [Display omitted] • Elucidating the role of ultrasound in intensifying enzyme activity. • Understanding into effect of ultrasonic parameters on intensification. • Ultrasonic bath was more effective than probe due to controlled cavitation. • Analysing various combinations of ultrasound treatment for enzyme and food waste. • Maximum sugar yield as 8.14 g/L using ultrasonic bath treated food waste and enzyme. [ABSTRACT FROM AUTHOR]