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Measurement of coating–substrate interface stiffness can indirectly characterize interface bonding quality. This paper proposes a noval quantitative inversion coating–substrate interface stiffness method based on the multi-resonance frequencies of a constructed ultrasonic echo phase derivative spectrum (UEPDS). The theoretical relationship between UEPDS resonance frequencies and interface stiffness is derived. The detection frequency and high-sensitivity interface stiffness range are optimized based on the sensitivity analyzed. Numerical simulation and experiment are implemented on a 0.48 mm aluminum layer/carbon steel substrate specimen to prove the validity of the proposed ultrasonic method. The simulation results show that the maximal relative error between the inversion and the preset interface stiffnesses is reduced from 23% to 8% compared with the traditional ultrasonic reflection coefficient amplitude spectrum-based (URCAS-based) method. The experiment results indicate that the UEPDS-based inversion interface stiffnesses have the same trend as the nominal contact pressures between the coating–substrate interface. [ABSTRACT FROM AUTHOR]

In this work, polymer PTB7, small-molecule PC71BM and also their blend films have been deposited by ultrasonic spray method and studied the effect of substrate temperature on the resulting film morphology, coffee stain effect and the resultant solar cell performance. A coffee stain is a dark-coloured edge that remains on the surface when the solvent evaporates from a drop containing particles. We observed that at a lower temperature, the spray droplets coalesce in the resulting film and therefore large structures were seen in the pristine films. In addition, the coffee stain effect was more prominent for lower temperatures. For PTB7 and PC71BM droplets, the values are 13 and 135 μm at 40°C, and 3 and 7 μm at 60°C. In blend film, the coffee stain effect follows the same trend as pristine films but to a lesser extent. We also find that the coffee ring width was more (7 μm at 60°C) in droplets with PC71BM having a lower molecular weight compared to that of PTB7 (3 μm at 60°C). The solar cell performance however shows that at lower substrate temperatures the device performs better, indicating that the disadvantages of the coffee stain effect are compensated by active-layer properties coated at lower temperatures. The device performance at 42°C substrate temperature was best due to low Rs = 93 Ωcm2 and highest Voc = 0.64 V and Jsc = 3.53 mA cm–2 values. As the substrate temperature was increased to 48°C, the Rs value increased and was equal to Rsh (500 Ωcm2), which led to low Jsc = 1.70 mA cm–2 and Voc = 0.50 V and eventually the lowest PCE. However, when coated at too low substrate temperatures the devices were shorted. Variations of Jsc and Voc with irradiation intensity show enhanced recombination mechanisms in higher substrate temperatures. [ABSTRACT FROM AUTHOR]

Ultrasonic assisted machining is an eco-friendly surface texture fabrication method with low machining cost, high-accuracy precision, and efficiency. This study analyzes the surface texture formation in feed direction ultrasonic vibration assisted milling (FUVAM) and elliptical ultrasonic vibration assisted milling (EUVAM). The trajectories of the single and adjacent tool tips in FUVAM are analyzed. Furthermore, the tool–workpiece separation mechanism in EUVAM is discussed. Moreover, a 3D surface topography model of EUVAM is applied to study the influences of machining parameters on the ultrasonic machining topography. The experiments of conventional milling (CM) and EUVAM are carried out and different types of surface textures are successfully fabricated on Ti-6Al-4V using EUVAM. The results of the response surface indicate that the surface roughness shows an increasing trend with higher spindle speed, but decreases with improved feed speed and cutting depth. Compared with CM, the chips generated in EUVAM have the characteristics of small width and low bending degree. This work is expected to provide some guidance for the selection of machining and vibration parameters during ultrasonic assisted milling. [ABSTRACT FROM AUTHOR]

A weak circumferential resolution of defects in the corner part of engineering components brings great challenges to quantitative non-destructive testing. Especially for the corner of carbon fiber reinforced plastics (CFRP), the complex wave propagation behaviors caused by the elastic anisotropy, laminate structure, and curved surface make the information of defects hard to be distinguished, which finally results in a poor imaging resolution. The surface adaptive ultrasonic (SAUL) method for CFRP corner is investigated, and an improved strategy, focusing in receiving (FiR) of SAUL signals is proposed here. With an isotropic plexiglass as a comparison, the effectiveness of FiR is verified by finite element simulations and experiments. The elastic properties of CFRP corner are accurately characterized and a finite element model is established. On this basis, the wave propagation behavior in the corner is studied, and the influence of the water distance h on the maximum amplitude (MAD) and signal-to-noise ratio (SNR) at the defect is analyzed. The results show that the structural noise can be eliminated, and the imaging quality and SNR can be improved by optimizing the h. After FiR, the maximum increase of defect amplitude is about 9.5 dB and 13.2 dB for plexiglass and CFRP, respectively. Meanwhile, the maximum relative error in length is reduced by 16.7% in plexiglass, and by 13.4% for the 3-mm delamination in CFRP. The strategy would be promising to improve the detection quality of the corner in curved components. [ABSTRACT FROM AUTHOR]

Borophene is an emerging two-dimensional material exhibiting exceptional piezocatalytic activity under the influence of ultrasonic vibrations, as exemplified herein by the decomposition of highly stable organic dyes in water. After 6 minutes of exposure, borophene sheets converted up to 92 percent of a mixture of dye molecules at room temperature. [ABSTRACT FROM AUTHOR]

AbstractIn this paper, the dissimilar joining of Poly Lactic Acid (PLA) with Cork Wood (CW) particles reinforced Poly Lactic Acid (CW/PLA) was made by using an Ultrasonic Welding (UW) process. The single lap joint was made to analyse the better joining with good adhesion between the neat polymer and Cork PLA polymer composite. The objective of this study is to formulate a good bonding of neat biodegradable polymeric material with Cork wood particles reinforced composite with concern to the UW factors like Ultrasonic Amplitude (UA), Welding Pressure (WP), and Welding Time (WT). The experimental trial was carried out by altering the levels of UW factors such as UA (25, 28 and 31 µm), WP (0.10, 0.15 and 0.20 MPa), and WT (1, 1.3 and 1.5 sec) with respect to attainment the higher lap shear strength. The statistical optimization methods, including Taguchi and Analysis of Variance, are employed to identify the optimum factors for the welding process and evaluate the proportional impact of the UW factors. The results revealed that the UA of 28 µm, WP of 0.15 MPa, and WT of 1.5 sec exhibits the higher lap shear strength of 24.16 MPa. For the optimized condition, the interface hardness was measured using the Shore D hardness method. The results imply that the maximum interface hardness of 75 was observed at the weld centre. Fractured samples clearly show that interfacial failure is absent, this dictates the weld regions are strong enough to hold the applied load. The developed regression model for the present UW process on the PLA and Cork wood PLA composite is significant and has an R2 value of 92.8%. So, the developed model is suitable for converting into large-scale industrial production and applications. [ABSTRACT FROM AUTHOR]

Based on the decorrelation calculation of diffusion ultrasound in time-frequency domain, this paper discusses the repeatability and potential significance of Disturbance Sensitive Zone (DSZ) in time-frequency domain. The experimental study of Barely Visible Impact Damage (BVID) on Carbon Fiber Reinforced Polymer (CFRP) is carried out. The decorrelation coefficients of time, frequency, and time-frequency domains and DSZ are calculated and compared. It has been observed that the sensitivity of the scattered wave disturbance caused by impact damage is non-uniformly distributed in both the time and frequency domains. This is evident from the non-uniform distribution of the decorrelation coefficient in time-domain and frequency-domain decorrelation calculations. Further, the decorrelation calculation in the time-frequency domain can show the distribution of the sensitivity of the scattered wave disturbance in the time domain and frequency domain. The decorrelation coefficients in time, frequency, and time-frequency domains increase monotonically with the number of impacts. In addition, in the time-frequency domain decorrelation calculation results, stable and repetitive DSZ are observed, which means that the specific frequency component of the scattered wave is extremely sensitive to the damage evolution of the impact region at a specific time. Finally, the DSZ obtained from the first 15 impacts is used to improve the decorrelation calculation in the 16-th to 20-th impact. The results show that the increment rate of the improved decorrelation coefficient is 10.22%. This study reveals that the diffusion ultrasonic decorrelation calculation improved by DSZ makes it feasible to evaluate early-stage damage caused by BVID. [ABSTRACT FROM AUTHOR]

Thrombus formation in extracorporeal membrane oxygenation (ECMO) remains a major concern as it can lead to fatal outcomes. To the best of our knowledge, there is no standard non-invasive method for quantitatively measuring thrombi. This study's purpose was to verify thrombus detection in an ECMO circuit using novel, non-invasive ultrasonic sensors in real-time, utilizing the fact that the ultrasonic velocity in a thrombus is known to be higher than that in the blood. Ultrasonic sensors with a customized chamber, an ultrasonic pulse-receiver, and a digital storage oscilloscope (DSO) were used to set up the measuring unit. The customized chamber was connected to an ECMO circuit primed with porcine blood. Thrombi formed from static porcine blood were placed in the circuit and ultrasonic signals were extracted from the oscilloscope at various ECMO flow rates of 1–4 L/min. The ultrasonic signal changes were successfully detected at each flow rate on the DSO. The ultrasonic pulse signal shifted leftward when a thrombus passed between the two ultrasonic sensors and was easily detected on the DSO screen. This novel real-time non-invasive thrombus detection method may enable the early detection of floating thrombi in the ECMO system and early management of ECMO thrombi. [ABSTRACT FROM AUTHOR]

A non-contact ultrasonic atomization based on the Fabry--Pérot resonator is proposed to obtain atomized droplets with a reduced droplet diameter and concentrated droplet distributions. To better understand the mechanism inside the acoustic chamber, the acoustic--fluid interactions are numerically explored inside the Fabry--Pérot resonator to achieve the precise modulation of droplets. The influence of the acoustic chamber's geometry and the ultrasonic properties on the atomized droplet diameter and distributions is investigated, aiming to establish matching relationships between the atomized droplet diameter and the geometry of the acoustic chamber. The dynamic behaviors of droplet breakup are observed with a high-speed camera to reveal the atomization mechanism of liquid droplets in high-intensity acoustic fields. The experiments demonstrate that the proposed non-contact atomization can achieve atomized water droplets with a median diameter of ~24 μm, providing an alternative to ultrasonic spray. [ABSTRACT FROM AUTHOR]

Machining of Nomex honeycomb composite (NHC) structures is of critical importance in manufacturing parts to the specifications required in the aerospace industry. However, the special characteristics of the Nomex honeycomb structure, including its composite nature and complex geometry, require a specific machining approach to avoid cutting defects and ensure optimal surface quality. To overcome this problem, this research suggests the adoption of RUM technology, which involves the application of ultrasonic vibrations following the axis of revolution of the UCK cutting tool. To achieve this objective, a three-dimensional finite element numerical model of Nomex honeycomb structure machining is developed with the Abaqus/Explicit software, 2017 version. Based on this model, this research examines the impact of vibration amplitude on the machinability of this kind of structure, including cutting force components, stress and strain distribution, and surface quality as well as the size of the chips. In conclusion, the results highlight that the use of ultrasonic vibrations results in an important reduction in the components of the cutting force by up to 42%, improves the quality of the surface, and decreases the size of the chips. [ABSTRACT FROM AUTHOR]

In recent years, ceramic membranes have been increasingly used in membrane bioreactors (MBRs). However, membrane fouling was still the core issue restricting the large‐scale engineering application of ceramic MBRs. As a novel and alternative technology, ultrasonic could be used to control membrane fouling. This research focused on the efficiency and mechanism of ultrasonic controlling membrane fouling in ceramic MBRs. The results showed that ultrasonic reduced the sludge concentration in MBR, and the average particle size of sludge was always in a high range. The sludge activity of the system was stable at 6–9 (mg O2·(g MLSS·h)−1), indicating that ultrasonic did not destroy the activity of microorganisms in the system. The extracellular polymer substance (EPS) of the ultrasonic group was slightly higher than that of the control group, while the soluble microbial product (SMP) content was relatively stable. The ceramic membrane of the ultrasonic group has a partial retention effect on the organic components. The application of ultrasonic slowed down the decrease of the hydrophilicity of the ceramic membrane. The main pollutants on the membrane surface exist in the form of aromatic and heteroaromatic rings, alkynes, and so forth. Ultrasonic removes the amide substances from the membrane surface. Membrane fouling resistance is mainly due to membrane pore blockage, accounting for 75.53%. Practitioner Points: Enrich the research on the mechanism of ultrasonic technology in membrane fouling control.The MBR can still operate normally with ultrasonic applied.The time for the ceramic membrane to reach the fouling end point is 2.4 times that without ultrasonic.The main cause of membrane fouling was pore blocking, accounting for 75.53%. [ABSTRACT FROM AUTHOR]

This study validates the mechanism of ultrasonic dehydration without transition of water into vapor. The process can be realized by cavitation dispersion of liquid initiated by collapse of cavitation bubbles of cylindrical shape formed in capillaries. The developed mathematical model considers the complete life cycle of cavitation bubbles, encompassing three stages: slow growth, rapid expansion with deformation, and collapse. The optimum range of sound pressure level from 150 dB (critical level) to 170 (limit level) at which cavitation dispersion of liquid from capillaries takes place has been determined. The optimum sample size corresponding to the ultrasonic wavelength in gas, at which the dehydrated productivity is maximized, has been determined. The mechanism of ultrasonic dispersion of liquid during drying was confirmed by experiments. Practical implementation of ultrasonic drying of food products (carrots) confirmed effectiveness of implementation of dehydration mechanism and provided a reduction of drying time by 1.9 times with a reduction of power consumption by 1.7 times. [ABSTRACT FROM AUTHOR]

Summary: Rats are known to use a 22‐kHz ultrasonic vocalisation as a distress call to warn of danger to other members of their group. We monitored 22‐kHz ultrasonic vocalisation emissions in rats (lean and obese) as part of a sleep deprivation study to detect the eventual presence of stress during the procedure. Unexpectedly, we detected ultrasonic vocalisation emission during rapid eye movement (REM) sleep, but not during non‐REM (NREM) sleep, in all the rats. The event occurs during the expiratory phase and can take place singularly or as a train. No difference was detected in the number or duration of these events in lean versus obese rats, during the light versus the dark period, and after sleep deprivation. As far as we know, this is the first report showing that rats can vocalise during REM sleep. [ABSTRACT FROM AUTHOR]

AISI 420 is primarily used for optic molds manufactured through ultraprecision machining with single-crystal diamond tools. Tool wear rapidly occurs due to the diffusion of diamond and iron atoms when cutting ferrous metals with diamond tools. In the machining of optic molds, the diamond tool is uniformly replaced, regardless of the tool status after use for some time due to the difficulty in predicting tool life. This practice results in the wastage of expensive single-crystal diamond tools and reduces productivity. This study addressed the aforementioned issue by developing a tool-life model through theoretical analysis of the effective contact ratio between the tool and the workpiece and a cutting experiment with high-frequency ultrasonic vibration. In addition, the effectiveness of ultrasonic vibration cutting on the suppression of diamond tool wear was demonstrated by measuring tool wear after the cutting experiments. [ABSTRACT FROM AUTHOR]

The global reliance on oil and gas pipelines for energy transportation is increasing. As the pioneering review in the field of ultrasonic defect detection for oil and gas pipelines based on bibliometric methods, this study employs visual analysis to identify the most influential countries, academic institutions, and journals in this domain. Through cluster analysis, it determines the primary trends, research hotspots, and future directions in this critical field. Starting from the current global industrial ultrasonic in-line inspection (ILI) detection level, this paper provides a flowchart for selecting detection methods and a table for defect comparison, detailing the comparative performance limits of different detection devices. It offers a comprehensive perspective on the latest ultrasonic pipeline detection technology from laboratory experiments to industrial practice. [ABSTRACT FROM AUTHOR]

Ultrasonic treatment has been widely used in the mineral flotation process due to its advantages in terms of operational simplicity, no secondary pollutant formation, and safety. Currently, many studies have reported the effect of ultrasonic treatment on mineral flotation and shown excellent flotation performance. In this review, the ultrasonic mechanisms are classified into three types: the transient cavitation effect, stable cavitation effect, and acoustic radiation force effect. The effect of the main ultrasonic parameters, including ultrasonic power and ultrasonic frequency, on mineral flotation are discussed. This review highlights the uses of the application of ultrasonic treatment in minerals (such as the cleaning effect, ultrasonic corrosion, and desulfuration), flotation agents (such as dispersion and emulsification and change in properties and microstructure of pharmaceutical solution), and slurry (such formation of microbubbles and coalescence). Additionally, this review discusses the challenges and prospects of using ultrasonic approaches for mineral flotation. The findings demonstrate that the application of the ultrasonic effect yields diverse impacts on flotation, thereby enabling the regulation of flotation behavior through various treatment methods to enhance flotation indices and achieve the desired objectives. [ABSTRACT FROM AUTHOR]

Spinal decompression and osteotomies are conventionally performed using high-speed drills (HSDs) and rongeurs. The ultrasonic bone scalpel (UBS) is a tissue-specific osteotome that preferentially cuts bone while sparing the surrounding soft tissues. There is ongoing investigation into its ability to optimize peri- and postoperative outcomes in spine surgery. The purpose of this study was to compare the intraoperative metrics and complications during a transition period from HSD to UBS. A single-institution, single-surgeon retrospective analysis was conducted of patients undergoing spine surgery from January 2020 to December 2021. Statistical analyses were performed to detect associations between the surgical technique and outcomes of interest. A P value < 0.05 was considered statistically significant. A total of 193 patients met the inclusion criteria (HSD, n = 100; UBS, n = 93). Multivariate logistic regression revealed similar durotomy (P = 0.10), nerve injury (P = 0.20), and reoperation (P = 0.68) rates. Although the estimated blood loss (EBL) and length of stay were similar, the operative time was significantly longer with the UBS (192.81 vs. 204.72 minutes; P = 0.03). Each subsequent surgery using the UBS revealed a 3.1% decrease in the probability of nerve injury (P = 0.026) but had no significant effects on the operative time, EBL, or probability of durotomy or reoperation. The UBS achieves outcomes on par with conventional tools, with a trend toward a lower incidence of neurologic injury. The expected reductions in EBL and durotomy were not realized in our cohort, perhaps because of a high proportion of revision surgeries, although these might be dependent on surgeon familiarity, among other operative factors. Future prospective studies are needed to validate our results and further refine the optimal application of this device in spine surgery. [ABSTRACT FROM AUTHOR]

The study determined the content of lycopene in the fruits of the Elaeagnus umbellata (35.25–60.21 mg/100 g), common at different heights above sea level in Western Georgia. For the effective extraction of lycopene as a biologically active substance, the optimal conditions for ultrasonic extraction were selected: sunflower oil was used as a "green solvent"; the ratio of solid mass and solvent was 1:50; temperature 30°C; ultrasound amplitude 40%; power 85 W; and extraction time 10 min. FTIR spectra revealed the characteristic functional groups of lycopene exhibiting two characteristic peaks at 2920 and 2950 cm−1. To explore the effect of lycopene on oil quality, the acid value, peroxide value, and p‐anisidine were determined in each oil sample. The antioxidant determination by inhibition of DPPH radicals showed significant differences in native oils and oils with lycopene. [ABSTRACT FROM AUTHOR]

Physiological and pathological changes in tissues often cause changes in tissue mechanical properties, making tissue elastography an effective modality in medical imaging. Among the existing elastography methods, ultrasound elastography is of great interest due to the inherent advantages of ultrasound imaging technology, such as low cost, portability, safety, and wide availability. However, most current ultrasound elastography methods are based on the bulk shear wave; they can image deep tissues but cannot image superficial tissues. To address this challenge, ultrasonic elastography methods based on surface acoustic waves have been proposed. In this paper, we present a comprehensive review of ultrasound‐based surface acoustic wave elastography techniques, including their theoretical foundations, technical implementations, and existing medical applications. The goal is to provide a concise summary of the state‐of‐the‐art of this field, hoping to offer a reliable reference for the further development of these techniques and foster the expansion of their medical applications. [ABSTRACT FROM AUTHOR]

We prepared 15 novel series of 1,3,4-thiadiazole containing benzo[d]imidazole compounds for the development of potential antimicrobial agents (6a–o). IR, 1H NMR, 13C NMR, and mass spectrometry were used to identify the bioactive structures of these compounds. Using the Broth Dilution method, the synthesized compounds were examined for antimicrobial activity against a variety of bacterial and fungal strains. Compounds 6j showed potency against bacterial strain P. aeruginosa, E. coli, and antifungal activity against A. clavatus at MIC values of 12.5 µg/mL, 50 µg/mL, and 100 µg/mL respectively. 6c, and 6e indicated antibacterial activity against P. aeruginosa at MIC values 62.5, and 50 µg/mL and antifungal activity against C. albicans MIC 250, 100, µg/mL respectively. Density (ρ), ultrasonic velocity (U), and viscosity (η) have been measured in a binary liquid mixture containing 1,3,4-thiadiazole and benzo[d]imidazole over the entire molality range at temperatures T = (303.15,308.15,313.15 and 318.15) K and different solvent DMSO and DMF. The experimentally obtained data have been used to determine the thermo-acoustical parameters adiabatic compressibility (κs), intermolecular free length (Lf), acoustical impedance (Z), and internal pressure (π). It is observed that in DMSO solutions, solute–solute interactions exist whereas solvent–solute interactions are predominant in DMF systems. [ABSTRACT FROM AUTHOR]

The inertness of carbon felt as cathode is still one of the challenges encountered in the degradation of pollutants by electro-Fenton. In this study, we used a simple ultrasonic oxidation method to introduce oxygen-containing groups and defect carbons on carbon felt surface to improve the electro-Fenton performance. The modified carbon felts were prepared by ultrasonic treatment in three dilute solutions of HNO3, H2SO4, and HNO3–H2SO4. Ultrasound can provide an extra energetic environment to accelerate the oxidation process, while NO3− has stronger oxidation properties in the presence of excess H+, greatly increasing the amounts of C–O–C/C=O and C–C active sites on carbon felt surface. And an electro-Fenton system with modified CF as the cathode was used to degrade rhodamine B, and the factors affecting the degradation were discussed. The results showed that the modified cathode material was significantly more efficient in degrading rhodamine B, under the conditions of O2 flow rate of 0.3 L min−1, pH = 3, voltage of − 0.7 V, and addition of 0.2-mM Fe2+, HNO3–H2SO4 solution modified CF with 37% higher than that of the raw CF, and the decolorization rate reached 96% after 120 min. Modified carbon felt still has good degradation properties after 5 cycles. The CF was modified by ultrasonic oxidation technique to introduce oxygen-containing functional groups and C-sp3 on the surface of the carbon felt.Using this CF as a cathode for the degradation of RhB in an electro-Fenton system. [ABSTRACT FROM AUTHOR]

Titanium alloy with high corrosion resistance, high strength-to-density ratio, and excellent biocompatibility has a wide range of applications in the field of biomedical implants. Polishing experiments of titanium alloy with a small size and complex shapes were investigated using an ultrasonic assisted magnetorheological finishing (UMRF) device excited by a three-pole magnetic field generator. The models of the normal force and the shear force were first proposed based on the Preston equation to analyze the mechanism of material removal in the UMRF process. Subsequently, the single-factor experiments using titanium alloy nuts (M3) and the MR polishing fluid with silicon carbide abrasives were carried out. Furthermore, to improve the surface roughness and the change rate of surface roughness of nuts, orthogonal tests with a standard L9(34) orthogonal array were designed and performed based on the optimized process parameters obtained from the single-factor experiment. The results indicated the effect on surface roughness and change rate of surface roughness as applied current > roller speed > ultrasonic amplitude > spindle speed and applied current > roller speed > spindle speed > ultrasonic amplitude, respectively. Moreover, the surface roughness was improved from an initial 1.247 μm to a final 0.104 μm after the polishing for 80 min under these optimal process parameters. [ABSTRACT FROM AUTHOR]

Titanium alloy with high corrosion resistance, high strength-to-density ratio, and excellent biocompatibility has a wide range of applications in the field of biomedical implants. Polishing experiments of titanium alloy with a small size and complex shapes were investigated using an ultrasonic assisted magnetorheological finishing (UMRF) device excited by a three-pole magnetic field generator. The models of the normal force and the shear force were first proposed based on the Preston equation to analyze the mechanism of material removal in the UMRF process. Subsequently, the single-factor experiments using titanium alloy nuts (M3) and the MR polishing fluid with silicon carbide abrasives were carried out. Furthermore, to improve the surface roughness and the change rate of surface roughness of nuts, orthogonal tests with a standard L9(34) orthogonal array were designed and performed based on the optimized process parameters obtained from the single-factor experiment. The results indicated the effect on surface roughness and change rate of surface roughness as applied current > roller speed > ultrasonic amplitude > spindle speed and applied current > roller speed > spindle speed > ultrasonic amplitude, respectively. Moreover, the surface roughness was improved from an initial 1.247 μm to a final 0.104 μm after the polishing for 80 min under these optimal process parameters. [ABSTRACT FROM AUTHOR]

Purpose: We aimed to evaluate the clinical efficacy of bilateral decompression with minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) assisted by an ultrasonic bone curette (UBC) for treating severe degenerative lumbar spinal stenosis (DLSS) and traditional tool laminectomy decompression MIS-TLIF for treating severe DLSS. Methods: The clinical data of 128 patients with single-segment severe DLSS who were admitted between January 2017 and December 2021 were retrospectively analyzed. Among them, 67 patients were treated with unilateral fenestration and bilateral decompression MIS-TLIF using an ultrasonic bone curette (UBC group), whereas 61 patients were treated with unilateral fenestration and bilateral decompression MIS-TLIF using traditional tools (traditional group, control). A visual analog scale (VAS) was used to evaluate back and lower limb pain before the operation,immediate postoperative, and one week, 3, 6, 12, and 24 months after the operation. Oswestry disability index (ODI) and Zurich claudication score (ZCQ) were employed to evaluate the improvement in low back and lower limb function. At the last follow-up, the Bridwell bone graft fusion standard was utilized to evaluate bone graft fusion. Results: The decompression time of laminectomy was significantly shorter in the UBC group than in the traditional group (control group), and the intraoperative blood loss and postoperative drainage volume were significantly less in those in the control group (P < 0.05). The VAS, ODI, and ZCQ scores of the two groups after the operation were significantly improved compared to those before the operation (P < 0.05). The UBC group had better VAS back scores than the control group immediate postoperative and one week after the operation(P < 0.05). The UBC group had better VAS lower limb scores than the control group immediate postoperative (P < 0.05).The incidence of perioperative complications, hospitalization time, dural sac cross-sectional area (CSA), and dural sac CSA improvement rate did not differ significantly between the two groups (P > 0.05). VAS and ODI scores did not differ significantly between the two groups before,three, six months, one year, and two years after surgery (P > 0.05). The ZCQ scores did not differ significantly between the two groups before the operation at one week, six months, one year, and two years after the operation (P > 0.05). According to the Bridwell bone graft fusion standard, bone graft fusion did not occur significantly between the two groups (P > 0.05) at the last follow-up. Conclusions: UBC unilateral fenestration bilateral decompression MIS-TLIF in treating severe DLSS can achieve clinical efficacy as traditional tool unilateral fenestration bilateral decompression MIS-TLIF and reduce intraoperative blood loss and postoperative drainage. It can also shorten the operation time, effectively reduce the work intensity of the operator, and reduce the degree of low back pain during short-term follow-ups. Therefore, this is a safe and effective surgical method. [ABSTRACT FROM AUTHOR]

Recently, researchers have devoted their intense efforts to investigating Weyl physics in synthetic space. In this Letter, we study the intriguing topological rotated Weyl physics in a three-dimensional parameter space, which consists of two extra structural parameters and the wave vector of a simple one-dimensional sonic crystal. In our ultrasonic experiments, we observe that the topological interface states propagate along the interface formed by two sonic crystals of distinct chirality caused by the rotated Weyl points. We detect the rotated synthetic Weyl points and measure the singularities of the reflection phase, which results in the robustness of the interface states. At the same time, it also shows the advantages of synthetic dimensions in exploring high-dimensional physics problems in low-dimensional systems. [ABSTRACT FROM AUTHOR]

The acoustic cavity structure typically experiences a sequence of transfigurations during its sinusoidal growth–collapse cycle. However, upon examining the cavity structure in aqueous bodies, it appears that the growth structure attained falls between two geometrical structures, namely, mushroom-like structure (MBS) and cone-like bubble structure (CBS), based on the actuated ultrasonic horn tip diameter. With the recurring observations of the emergence of proximal toroidal vortices, the present investigation conducts a numerical analysis exploring the vortex development under 3, 6, 13, 16, and 19 mm horn tips to establish a potential correlation between the vortex and the cavity structure. The study presents a computational fluid dynamic investigation to capture the nature of the vortex evolution, in terms of size and position, and its respective cavitation development. The first indicator of potential correlation was the equivalency of the vortex expansion–contraction frequency and the cavity's sub-harmonic frequency. It has been found that the cavity structure is molded into MBS by the presence of a symmetric locomotive vortex structure that extends up to 1.5 times the horn tip diameter. Meanwhile, CBS is observed to take shape in the presence of an eccentric locomotive vortex that attains a size within 0.2–0.6 times the horn tip diameter. The significance of the vortex size and position is also observed in the cavity's collapse, as the vortex appears to govern the ability of the cavity impinging jet to initialize the collapse phase. [ABSTRACT FROM AUTHOR]

Power ultrasound is widely used in industrial production, medical equipment, aerospace, and other fields. Currently, there are two main types of commonly used power generation devices: piezoelectric ultrasonic transducers and magnetostrictive ultrasonic transducers. However, in certain situations with limited external dimensions, the applications of existing power ultrasound devices are limited. In nature, leaf-cutting ants excite vibrations through their tiny organs. Inspired by the vibratory organs of leaf-cutting ants, a new type of biomimetic ultrasonic vibrator (BUV) comprising a scraper, dentate disc, and fixture system was proposed, fabricated, and tested in this study. The experimental results showed that the BUV could operate in the frequency range of 16.8–19 kHz. Within the working frequency range, the vibration of the BUV was stable and the amplitude of the vibration displacement was greater than 22 µm. The operating frequency band of the BUV was broader than those of the piezoelectric and magnetostrictive ultrasonic transducers. In addition, the BUV can cut soft rubber and pig tissues with sufficient output power and load-carrying capacity. The BUV, as a new type of power ultrasonic excitation device, is expected to be applied in high-power micro operating scenarios, such as minimally invasive surgical instruments. [ABSTRACT FROM AUTHOR]

We develop decision support and automation for the task of ultrasonic non-destructive evaluation data analysis. First, we develop a probabilistic model for the task and then implement the model as a series of neural networks based on Conditional Score-Based Diffusion and Denoising Diffusion Probabilistic Model architectures. We use the neural networks to generate estimates for peak amplitude response time of flight and perform a series of tests probing their behavior, capacity, and characteristics in terms of the probabilistic model. We train the neural networks on a series of datasets constructed from ultrasonic non-destructive evaluation data acquired during an inspection at a nuclear power generation facility. We modulate the partition classifying nominal and anomalous data in the dataset and observe that the probabilistic model predicts trends in neural network model performance, thereby demonstrating a principled basis for explainability. We improve on previous related work as our methods are self-supervised and require no data annotation or pre-processing, and we train on a per-dataset basis, meaning we do not rely on out-of-distribution generalization. The capacity of the probabilistic model to predict trends in neural network performance, as well as the quality of the estimates sampled from the neural networks, support the development of a technical justification for usage of the method in safety-critical contexts such as nuclear applications. The method may provide a basis or template for extension into similar non-destructive evaluation tasks in other industrial contexts. [ABSTRACT FROM AUTHOR]

The use of grain refiners plays a crucial role in the casting of Al alloys, and ultrasonic treatment is increasingly applied. This paper focuses on the numerical simulations of 2219, an Al–Cu alloy, using different processes for introducing Al–5Ti–1B grain refiner, along with mechanical stirring and ultrasonic treatment. The multiphase Computational Fluid Dynamics (CFD) model considers turbulent fluid flow, heat transfer, solidification, and the complex interaction between the 2219 Al alloy and TiB2 particles. Ansys's fluent dense discrete phase model (DDPM) and a particle engulfment and pushing (PEP) model are utilized for this purpose. The study investigates the fluid flow patterns and the distribution of TiB2 particles. Additionally, four control experiments are designed to correspond with the numerical simulations, enabling the investigation of the variations in α-Al grains and Al2Cu precipitation phases. The findings demonstrate that direct introduction of Al–5Ti–1B into the ultrasonic sonotrode results in uniform dispersion of TiB2 particles in the Al melt, reduction in α-Al grain size, and decreased area fraction of Al2Cu precipitated phase. The numerical simulation results are successfully validated through experimentation. Al–5Ti–1B ultrasonic sonotrode along with ultrasonic treatment has a good effect on 2219 Al alloy. [ABSTRACT FROM AUTHOR]

Ultrasonic diagnostics is the earliest way to predict industrial faults. Usually, a contact microphone is employed for detection, but the recording will be contaminated with noise. In this paper, a dataset that contains 10 main faults of pipelines and motors is analyzed from which 30 different features in the time and frequency domains are extracted. Afterward, for dimensionality reduction, principal component analysis (PCA), linear discriminant analysis (LDA), and t-distributed stochastic neighbor embedding (t-SNE) are performed. In the subsequent phase, recursive feature elimination (RFE) is employed as a strategic method to analyze and select the most relevant features for the classifiers. Next, predictive models consisting of k-Nearest Neighbor (KNN), Logistic Regression (LR), Decision Tree (DT), Gaussian Naive Bayes (GNB), and Support Vector Machine (SVM) are employed. Then, in order to solve the classification problem, a stacking classifier based on a meta-classifier which combines multiple classification models is introduced. Furthermore, the k-fold cross-validation technique is employed to assess the effectiveness of the model in handling new data for the evaluation of experimental results in ultrasonic fault detection. With the proposed method, the accuracy is around 5% higher over five cross folds with the least amount of variation. The timing evaluation of the meta model on the 64 MHz Cortex M4 microcontroller unit (MCU) revealed an execution time of 11 ms, indicating it could be a promising solution for real-time monitoring. [ABSTRACT FROM AUTHOR]

Ultrasound is extremely efficient for wireless signal transmission through metal barriers due to no limit of the Faraday shielding effect. Echoing in the ultrasonic channel is one of the most challenging obstacles to performing high-quality communication, which is generally coped with by using a channel equalizer or pre-distorting filter. In this study, a deep learning algorithm called a dual-path recurrent neural network (DPRNN) was investigated for echo cancellation in an ultrasonic through-metal communication system. The actual system was constructed based on the combination of software and hardware, consisting of a pair of ultrasonic transducers, an FPGA module, some lab-made circuits, etc. The approach of DPRNN echo cancellation was applied to signals with a different signal-to-noise ratio (SNR) at a 2 Mbps transmission rate, achieving higher than 20 dB SNR improvement for all situations. Furthermore, this approach was successfully used for image transmission through a 50 mm thick aluminum plate, exhibiting a 24.8 dB peak-signal-to-noise ratio (PSNR) and a about 95% structural similarity index measure (SSIM). Additionally, compared with three other echo cancellation methods—LMS, RLS and PNLMS—DPRNN has demonstrated higher efficiency. All those results firmly validate that the DPRNN algorithm is a powerful tool to conduct echo cancellation and enhance the performance of ultrasonic through-metal transmission. [ABSTRACT FROM AUTHOR]

This study aimed to investigate the effects of reproducing an ultrasonic sound above 20 kHz on the subjective impressions of water sounds using psychological and physiological information obtained by the semantic differential method and electroencephalography (EEG), respectively. The results indicated that the ultrasonic component affected the subjective impression of the water sounds. In addition, regarding the relationship between psychological and physiological aspects, a moderate correlation was confirmed between the EEG change rate and subjective impressions. However, no differences in characteristics were found between with and without the ultrasound component, suggesting that ultrasound does not directly affect the relationship between subjective impressions and EEG energy at the current stage. Furthermore, the correlations calculated for the left and right channels in the occipital region differed significantly, which suggests functional asymmetry for sound perception between the right and left hemispheres. [ABSTRACT FROM AUTHOR]

Regarding the low machining efficiency and poor surface quality in micro-electrical discharge machining (μ-EDM) of large depth-to-diameter ratio micro-holes, this paper focuses on ultrasonic vibration–assisted multi-objective optimization in μ-EDM to achieve high material removal rate (MRR) and low tool wear rate (TWR). In this work, second-order quadratic models were developed for MRR and TWR, considering the peak voltage (U p), peak current (I p), pulse width (Width), frequency (Freq.), ultrasonic amplitude (UA), and rotation speed (Rot.) as the machining parameters, using the Plackett–Burman design and Box–Behnken design. The developed models were used for multi-objective optimization by desirability function approach to determine the optimum machining parameters. The optimized parameters were processed for micro-holes, and it was found that the surface quality of the micro-holes was significantly improved. [ABSTRACT FROM AUTHOR]

Driven by the trend toward sustainable foods, insoluble fiber particles from by-products have attracted interest as Pickering stabilizers. In this work, the relationship between particle/structural properties and emulsion-stabilizing properties of ultrasonic autoclaving alkaline-treated insoluble soybean fiber (ISF) from okara as a novel stabilizer and the stability of ISF-stabilized emulsions under different environmental conditions were investigated. The results showed that when the contact angle of ISF was close to 90° and the structural looseness of ISF and the interaction between ISF were at moderate levels, the ISF-stabilized emulsions exhibited relatively high stability against creaming and ISF particle deposition. The ISF-stabilized oil droplets existed in well-dispersed and aggregated forms, and the latter was formed by the simultaneous adsorption of a large number of oil droplets onto the multi-branched clustered ISF. After heating at 85 °C for 30 min or treatment with 100 mM NaCl or pH 5, the emulsions maintained good anti-creaming stability and long-term storage stability. Analysis of the microstructure, elastic modulus G', and ζ-potential of the emulsions indicated that the aforementioned stable oil droplet aggregates and the gel-like network structure played a major role in the stabilization of the emulsions, while the electrostatic repulsion played a minor role. This study provides a theoretical basis for the application of ISF from okara in food emulsion formulations. [ABSTRACT FROM AUTHOR]

Grapes are one of the most important agricultural products which could be used either as a fresh fruit or a processed food. In Iran, grapes are very crucial agricultural and commercial products. Every year, a massive volume of grapes waste is made by the units of grape Doshab producers, so the producers are engaging with many problems of waste disposal. Grapes waste is a valuable source of natural pigment and antioxidant compounds specifically polyphenols compounds. Extracting antioxidant compounds from cheap primary materials like grapes waste is a suitable method for various food and pharmaceutical industries. In this research and aim to finding optimum state for extracting phenolic compounds from Shani grapes skin, response surface method (RSM) and central composite design (CCD) with 3 independent variables (extraction time using ultrasonic bath, liquid to solid phase ratio and ethanol solvent concentration) were applied. The optimum condition for extraction of this compound was 59.06% concentration of ethanol, 16.08 ml/g liquid to solid phase ratio and 24.12 min extraction time. The research results have shown that the extract of Shani grapes skin contains 8 different phenolic compounds, which among them epigallocatechin and catechin had highest concentration. Consequently, by finding optimum condition of phenolic compounds extraction, these compounds could be produced in pilot scale for utilizing in food and pharmaceutical industries. [ABSTRACT FROM AUTHOR]

Drying is one of the most effective ways to increase the shelf life and preserve the valuable compounds of Foodstuffs, which can be improved by using different methods and materials. Using bioactivecompounds as a pre-treatment can be one of the effective ways to increase their bioactive and antibacterial properties. This research was conducted to simultaneously apply ultrasonic pretreatment and pure apple vinegar before drying garlic slices, and investigate their effect on the bioactive and antibacterial properties of garlic slices dried by hot air. Slices of garlic were subjected to pure apple vinegar and ultrasonic treatment for ten minutes at 35 °C and they were placed before the drying process and dried using a hot air displacement dryer at a temperature of 50 °C to a final moisture content of 6% on a wet basis. After evaluating chemical properties, including the content of total phenolic and flavonoid compounds, the determination of functional properties, antioxidant and antibacterial properties were evaluated. The results showed that the simultaneous use of ultrasound and pure apple vinegar had a significant impact on the amount of bioactive compounds and antibacterial properties of dried garlic slices. Pre-treated samples with pure apple vinegar had a more significant impact on increasing functional properties than the ultrasound pretreatment, and it eventually became clear that the use of ultrasonic pretreatments and pure apple vinegar improved the quality, bioactive, and antibacterial properties of sliced dry garlic samples. [ABSTRACT FROM AUTHOR]

An orchard sprayer prototype running a variable-rate algorithm to adapt the spray volume to the canopy characteristics (dimensions, shape and leaf density) in real-time was designed and implemented. The developed machine was able to modify the application rate by using an algorithm based on the tree row volume, in combination with a newly coefficient defined as Density Factor (Df). Variations in the canopy characteristics along the row crop were electronically measured using six ultrasonic sensors (three per sprayer side). These differences in foliage structure were used to adjust the flow rate of the nozzles by merging the ultrasonic sensors data and the forward speed information received from the on-board GNSS. A set of motor-valves was used to regulate the final amount of sprayed liquid. Laboratory and field tests using artificial canopy were arranged to calibrate and select the optimal ultrasonic sensor configuration (width beam and signal pre-processing method) that best described the physical canopy properties. Results indicated that the sensor setup with a medium beam width offered the most appropriate characterization of trees in terms of width and Df. The experimental sprayer was also able to calculate the application rate automatically depending on changes on target trees. In general, the motor valves demonstrated adequate capability to supply and control the required liquid pressure at all times, mainly when spraying in a range between 4.0 and 14.0 MPa. Further work is required on the equipment, such as designing field efficiency tests for the sprayer or refining the accuracy of Df. [ABSTRACT FROM AUTHOR]

Composite sandwich structures are widely used for their mechanical properties combined to lightweight. However, damage area quantification caused by low velocity impacts represents generally a crucial task in sandwich composites. In the last years, recent advantages of thermographic devices offer new promising and different real-time industrial and engineering applications where lower computation time, accuracy of results and convenient cost are required. The present research deals with the comparison of standard or latest image-processing methods proposed for pulsed thermography regarding their suitability for determining the impact damage area in sandwich materials made of Aluminium core an a GFRP laminated skins. The Infra-Red processed results are compared with the advanced ultrasonic Phased array method commonly employed in the industrial Non-Destructive Testing. Specifically, the damage area quantification is performed by means of an appropriate MATLAB binarization algorithm for the post-processing of acquired thermal and ultrasonic maps. The data results verify the effectiveness of the image-processing thermographic technique combined to advanced processing approaches for the quantitative assessment of impact damage in sandwich component. [ABSTRACT FROM AUTHOR]

This study employed soxhlet and ultrasonic methods to extract novel natural dyes from Rhamnus tinctoria seed, Rubia fruticosa fruits, and Pinus pinea bark, which were then used as sensitizers in dye-sensitized solar cells (DSSCs). XRD data showed that TiO2 in the photoanode layer was in the anatase phase. The produced DSSCs were assessed for photovoltaic performance and electrochemical charge transfer while sensitizing dyes were characterized using UV–vis spectroscopy and FTIR. Natural dyes leached with different extraction methods showed different absorption behaviors in the UV–vis region. FTIR results revealed the presence of both carbonyl and hydroxyl groups, which enhanced the interaction between the extracted dyes and the TiO2 thin film. All cells using sensitizers obtained by the Soxhlet method showed higher efficiency compared to the ultrasonic method. The highest cell performance (ɳ = 0.47%) was obtained with 0.71 V Voc, 0.92 mA/cm2 Jsc, and 0.72 FF for the sensitizer extracted from Rhamnus tinctoria seeds by the soxhlet method. [ABSTRACT FROM AUTHOR]