Ultrasonic Processing Time Research Articles

Causal inference and mechanism for unraveling the removal of four pesticides from lettuce (Lactuca sativa L.) via ultrasonic processing and various immersion solutions

This study explores the reduction of carbamates (CAs) and pyrethroids (PYs) − commonly used pesticides − in lettuce using various immersion solutions and ultrasonic processing. It also examines the role of machine learning and molecular docking in understanding the mechanisms of pesticide reduction. The results revealed that the highest reduction of both CAs and PYs exceeded 80 % on lettuce leaves. In most samples, the reduction increased with the power of ultrasonic processing and processing time. The results of machine learning models (XGBoost and SHAP) showed that during the immersion cleaning of CAs and PYs, as well as during both immersion cleaning and ultrasonic processing of CAs + PYs, the reduction was most influenced by the initial pesticide levels and immersion time. Gas Chromatography-Mass Spectrometry (GC–MS) analysis of lettuce’s wax layer identified 24 compounds, including fatty alcohols, fatty acids, fatty acid esters, and triterpenoids. Despite the absence of active sites, the lipophilic nature of long-chain aliphatic compounds aids in pesticide binding, while triterpenoids form strong hydrogen bonds with pesticides, indicating a robust adsorption on the lettuce surface. This study aims to offer insights into the efficient removal of chemical pesticide residues from fruits and vegetables, addressing critical concerns for food safety and human health.

The Design and Process Parameters for the Optimization of an Ultrasonic—Thermal Co-Sterilization System for Liquid Eggs

The sterilization of liquid eggs plays a crucial role in the production of liquid egg products. Traditional pasteurization techniques can easily cause protein denaturation, while non-thermal sterilization techniques are often constrained by processing intensity and time. Improving the effectiveness of liquid egg sterilization while preserving the stability of its functional attributes poses a significant challenge. In response to this issue, a synergistic ultrasonic mild thermal sterilization system for liquid eggs is proposed, accompanied by the optimization of its process parameters. COMSOL is employed to simulate the acoustic field distribution of the ultrasonic–thermal system in the liquid egg medium. Verification is conducted through acoustic intensity measurements, and analysis is performed to obtain the optimal arrangement of ultrasonic transducers. Based on Modbus communication, an ultrasonic–thermal synergistic sterilization system is designed. Sterilization experiments are conducted with both 20 kHz + 28 kHz and 20 kHz + 40 kHz multifrequency ultrasound, compared with traditional 20 kHz single-frequency ultrasound. The results indicate that multifrequency ultrasound improves sterilization efficiency by approximately 15% compared to traditional single-source ultrasound. Utilizing multifrequency ultrasonic–thermal synergistic sterilization experiments, a three-factor, three-level response surface test is conducted with sterilization rate and foaming properties as evaluation criteria. The results indicate a strong correlation between ultrasonic frequency, processing time, heating temperature, and sterilization performance, with the impact magnitude being sterilization temperature > processing time > ultrasound frequency. Parameter optimization analysis is performed using a genetic algorithm, yielding sterilization conditions of 55 °C, 11 min and 30 s processing time, and 20 + 40 kHz ultrasonic frequency. The liquid egg sterilization rate is 99.32%, an average decimal reduction of 3.17 log values, and foaming properties are 42.79%.Through comparative analysis, it is determined that the sterilization rate of the ultrasonic–thermal synergistic sterilization system meets national standards, and functional properties such as foaming are superior to traditional pasteurization. This validates the proposed ultrasonic–thermal synergistic liquid egg sterilization control system as effective and feasible.

Ultrasonic degassing of molten magnesium and its alloys by cavitation

This paper describes ultrasonic degassing (USD) in commercial pure magnesium (CP-Mg), AZ31 and AZ61 Mg alloy. In this study, the efficiency of degassing under different ultrasonic parameters is evaluated by porosity volume and computer tomography (CT), and the mechanism of USD is further discussed. The results indicate that ultrasonic power, processing time and melt temperature strongly affect the degassing efficiency. Under suitable ultrasonic conditions, USD is an efficient method to reduce porosity formation in CP-Mg and its alloys.

Effect on the Quality of Larimichthys crocea Pretreated with Dual-Frequency Orthogonal Ultrasonic-Assisted Immersion with Different Powers during Refrigerated Storage at 4 °C.

In recent years, ultrasonic pretreatment technology has been widely used in the aquatic product preservation industry. Among these technologies, dual-frequency ultrasonic refrigeration is the most common. However, in practical applications, selecting the frequency is relatively simple, and there has been less research on power selection. In this paper, the specific frequency (up and down 20 kHz, around 40 kHz), using different powers of (a) 200 W, (b) 300 W, and (c) 400 W processing, ultrasonic intermittent mode with 30 s on/30 s off cycle, and an ultrasonic processing time of 10 min was examined; the control group (CK) comprised samples without ultrasonic treatment. The samples were stored at 4 °C and then placed in a Polyethylene (PE) bag. The changes in microbiological parameters, physicochemical indices, and protein indices of the samples were monitored every two days. The results show that 400 W ultrasonic treatment can significantly inhibit the growth of TVC during storage. The rate of increase in pH, TVB-N, and TBA values decreased significantly compared with the other groups. Compared with the CK group, the shelf life of the 400 W treatment group was extended by 6 days. Therefore, the 400 W pretreatment method based on orthogonal double frequency has strong application potential for effectively extending the shelf life of refrigerated large yellow croaker.

Improvement of microstructure and acquirement of excellent mechanical properties of high-Nb Ti2AlC/TiAl alloy by Ta under ultrasonic action in solid-liquid zone

To promote element diffusion in the solid-liquid two-phase region, optimize solidification microstructure, and improve the matching degree of strength and toughness, Ti–46Al–8Nb-2.6C-xTa (at. %) alloys were prepared by arc melting under the action of ultrasound. The lamellar colony, precipitate phase, elements distribution, and related mechanisms were analyzed. Results show that the relative content of the γ phase decreases, while the relative content of the α2 phase and Ti2AlC phase increases as the addition of Ta increases. The coarse long rod-shaped Ti2AlC transforms into short rod-shaped particles. The lamellar colony size reduces from 32.1 to 18.6 μm, the lamellar spacing reduces from 1.4 to 0.7 μm, and the aspect ratio of Ti2AlC reduces from 5.8 to 2.5 as the addition of Ta increases from 0 to 1.0 at. %. The acoustic streaming effect of ultrasound promotes the diffusion of tantalum in the solid-liquid two-phase region for a certain ultrasonic processing time. Tantalum is a heterogeneous nucleation particle of Ti2AlC particles and causes composition supercooling at the forefront of the solidification interface, which is the main reason for refining the microstructure. Compressive strength increases from 1996 to 2596 MPa and the strain increases from 25.4 to 29.3% as the addition of Ta increases from 0 to 0.6 at. %. The main reasons for improving the properties of alloy are the refinement of the microstructure and the formation of a large number of dislocations.

Application of High-Intensity Ultrasound on Acerola (Malpighia emarginata) Juice Supplemented with Fructooligosaccharides and Its Effects on Vitamins, Phenolics, Carotenoids, and Antioxidant Capacity

Acerola is considered a superfruit, rich in vitamin C, phenolics, and carotenoids, and having a high antioxidant capacity. However, it is poor in oligosaccharides. Ultrasound technology can improve the bioavailability of several bioactive compounds, improving the nutritional content of several fruit juices. This work evaluated the use of ultrasound processing on acerola juice supplemented with fructooligosaccharides (FOS; 1% w/w) and its effects on the availability of vitamins, carotenoids, and phenolic content. The antioxidant capacity of the juice was correlated with its bioactive contents. The study evaluated the effects of important sonication parameters, such as ultrasonic power density, processing time, and processing temperature. The application of ultrasound was efficient in increasing the availability of some vitamins. As a result, ultrasound application increased the availability of vitamins B1, B3, B5, C, carotenoids, and phenolic compounds. This improvement increased the antioxidant activity of the FOS-enriched acerola juice.

Scaling up the fabrication of wafer-scale Ni-MoS2/WS2 nanocomposite moulds using novel intermittent ultrasonic-assisted dual-bath micro-electroforming

In the scale-up fabrication process for electroformed Ni-MoS2/WS2 composite moulds, the formulation of nanosheets is critical, since the size, charge, and their distribution can largely affect the hardness, surface morphology and tribological properties of the moulds. Additionally, the long-term dispersion of hydrophobic MoS2/WS2 nanosheets in a nickel sulphamate solution is problematic. In this work, we studied the effect of ultrasonic power, processing time, surfactant types and concentrations on the properties of nanosheets to elaborate their dispersion mechanism and control their size and surface charge in divalent nickel electrolyte. The formulation of MoS2/WS2 nanosheets was optimized for effective electrodeposition along with nickel ions. A novel strategy of intermittent ultrasonication in the dual bath was proposed to resolve the problem of long-term dispersion, overheating, and deterioration of 2D material deposition under direct ultrasonication. Such strategy was then validated by electroforming 4-inch wafer-scale Ni-MoS2/WS2 nanocomposite moulds. The results indicated that the 2D materials were successfully co-deposited into composite moulds without any defects, along with the mould microhardness increasing by ∼2.8 times, the coefficient of friction reducing by two times against polymer materials, and the tool life increasing up to 8 times. This novel strategy will contribute to the industrial manufacturing of 2D material nanocomposites under ultrasonication process.

Facile Preparation of Four-Layer MoS2 Nanosheets and Their Application to Organic Light-Emitting Diode

High-quality four-layer molybdenum disulfide (MoS2) nanosheets with lateral dimension of about 11 µm were prepared by ultrasonic treatment of MoS2 powder with assistance of 1-methyl-2-pyrrolidone (NMP) solvent. The optimal preparation conditions for the preparation of MoS2 nanosheets were investigated from the aspects of ultrasonic processing time, ultrasonic power and amount ratio of MoS2 powder and NMP solvent. At the same time, the MoS2 nanosheets were employed as anode buffer layer in organic light-emitting diode (OLED) with copper nanowire (CuNW) film being anode. MoS2 nanosheets can reduce roughness of CuNW film, protect CuNW film from oxidation and improve work function of CuNW film. Experiments show that MoS2 nanosheets can significantly improve the current density and brightness of the OLED with CuNW film being anode. The maximum brightness of the OLED with MoS2 anode buffer layer is 2.15 times that of the OLED without MoS2 anode buffer layer. The current density of the OLED with MoS2 anode buffer layer is also obviously increased compared with the OLED without MoS2 anode buffer layer.

Corrosion resistance of 3D printed SS316L post-processed by ultrasonic shot peening at optimum energy level

The layer-upon-layer nature of production by additive manufacturing (AM) made surface treatment as mandatory post-processing for increasing the surface integrity and subsequent tribological properties. In the present work an experimental study was carried out to understand how the ultrasonic shot peening (USP) enhances the corrosion rate, surface compressive residual stress, surface roughness and hardness of stainless steel 316 manufactured by selective laser melting (SLM). In order to do so, series of USP experiments carried out based on full factorial design taking into account the effects of ultrasonic power, processing time, and ball diameters on foresaid responses. Multi-objective optimization of process using desirability approach function was performed to obtain a process window including trade-off between energy consumption and sample’s quality characteristics. The optimization results revealed that it is not possible to have minimum energy and the best product’s quality at same time. In other word, to fabricate samples with best quality characteristics, more energy needs to be consumed. The optimum sample was selected through the trade-off graph based on the transition point where after this point the energy consumption dramatically increases but no further improvement in product’s quality characteristics are attained. By identifying the optimum sample, series of surface integrity examination tests were carried out to show the efficiency of USP on enhancement the surface integrity and corrosion properties of AM material. It was found that the sample processed by USP at optimum parameter setting by ultrasonic power of 60%, process time of 15 min, and ball diameter of 6 mm is an optimum process setting that meets the condition described for transition point and causes 120% improvement in corrosion rate.

Kinetics of epoxy resin optical characteristics during ultrasonic processing

In this paper, the ultrasonic processing of composite based on epoxy resin ED-20 filled by nanoparticle silicon–containing additives PDMS-5 and HDK during its preparation is studied. Changes in optical transmittance spectra of organosilicon gel (PDMS-5+HDK) and of composite ED-20+L-20+(PDMS-5+HDK) are reported. The observed optical transmission changes were modeled from the experimental results. New phenomenological model describing the kinetics of a change in transmittance with ultrasonic processing time of composite is proposed. The nonlinear differential equation of the process is formulated and solved. The solution of equation applies to description of the experimental data of monitoring of transmittance of composite ED-20+L-20+(PDMS-5+HDK) during ultrasonic processing. The nonlinear functions characterized by three plateaus are proposed to describe the experimental data of monitoring of optical properties of organosilicon gel (PDMS-5+HDK) during ultrasonic processing.

Effects of ultrasound and microwave pretreatments on hydrodistillation extraction of essential oils from Kumquat peel.

Main objectives of this work were to investigate the influences of ultrasound pretreatment (UP) and microwave pretreatment (MP) on extraction kinetics, chemical composition, and antioxidant activity of Kumquat peel essential oil (EO) obtained by hydrodistillation extraction (HDE). The effects of ultrasound power and processing time, and microwave power and processing time were evaluated. As compared with HDE individually, UP and MP decreased the extraction time, increased the yield and DPPH radical‐scavenging activity but did not noticeably affect chemical composition of the EO. For UP and MP, the highest EO yield was obtained when the ultrasonic power and processing time, and microwave power and processing time were 210 W and 30 min, 300 W and 6 min, respectively. In comparison with MP, UP gave a higher yield and DPPH radical‐scavenging activity of the EO. Overall, UP and MP are promising techniques for HDE of EO from kumquat peel.

Removal of colloidal precipitation plugging with high-power ultrasound

Petroleum is a continuous and dynamically stable colloidal system. In the process of oil extraction, transportation, and post-treatment, the stability of the petroleum sol system is easily destroyed, resulting in asphaltenes precipitation that can make pore throat, oil wells, and pipelines blocked, thereby damaging the reservoir and reducing oil recovery. In this paper, removing near-well plugging caused by asphaltene deposition with high-power ultrasound is investigated. Six PZT transducers with different parameters were used to carry out the experimental study. Results show that ultrasonic frequency is one important factor for removing colloidal precipitation plugging in cores, it could not be too high nor too low. The optimum ultrasonic frequency is 25 kHz; Selecting transducers with a higher power is an effective way to improve the removal efficiency. The optimum ultrasonic power is 1000 W. With the increase of ultrasonic treatment time, the recovery rate reaches the maximum and tends to be stable. ultrasonic processing time should be controlled within 120 min. Besides, three methods — ultrasonic treatment alone, chemical injection alone, and ultrasound-chemical method — for removing colloidal precipitation plugging are compared. Results indicate that the ultrasound-assisted chemical method is better than chemical injection alone or ultrasonic treatment alone to remove colloidal sediment in the core. Finally, the mechanism of the ultrasonic deplugging technique is analyzed from three aspects: cavitation effect, the thermal effect, and mechanical vibration.

Study on ultrasound-assisted liquid-phase exfoliation for preparing graphene-like molybdenum disulfide nanosheets.

Nanomaterials with graphene-like structures have many excellent properties different from bulk materials and have become one of the most popular international frontiers in recent years. In this paper, graphene-like molybdenum disulfide materials are prepared by ultrasonic exfoliation method assisted with 1-Dodecanethiol. Double solvent ultrasonic exfoliation is realized by introducing chloroform. In addition, the optimal preparation conditions for the preparation of graphene-based molybdenum disulfide are investigated from the aspects of ultrasonic processing time and volume ratio of 1-Dodecanethiol and chloroform. Ultrasonic cleaning instrument is used in the experiment, it's type is KQ3200E (40KHz, 150W). Results show that the prepared graphene-like molybdenum disulfide has the highest concentration when the volume ratios of 1-Dodecanethiol and chloroform is 1:1 and ultrasonic processing time is 12h. The dispersion of graphene-like molybdenum disulfide in low-boiling organic solvents, such as chloroform, tetrahydrofuran (THF), isopropanol (IPA), acetone, acetonitrile (CH3CN) and ethanol, is realized by solvent exchange method. Characterized by transmission electron microscopy, a relatively thin sheet material is obtained. In addition, the latest methods for preparing graphene-like molybdenum disulfide nanosheet are discussed in view of micromechanical exfoliation, lithium ion intercalation, chemical vapor deposition and chemical synthesis, the advantages and limitations of various preparation methods are compared, the applications of graphene-like molybdenum disulfide nanosheets are also investigated.

Green ultrasound-assisted extraction of chlorogenic acids from sweet potato peels and sonochemical hydrolysis of caffeoylquinic acids derivatives.

Sweet potato peels are rich in chlorogenic acids. In this work, we applied ultrasound technology to extract the main compounds from sweet potato peel and used multivariate analysis and principal component analysis (PCA) to evaluate the effects of different extraction conditions on the extraction of chlorogenic acids. The extraction was studied varying ultrasonic power density (20, 35 and 50W/L) and processing time (5, 10, 20 and 40min) using an ultrasonic bath operating at 25kHz. The chemical analysis was carried out by UPLC-qTOF-MS, and the results were evaluated by PCA and PLS-DA chemometric analysis. Results show that both ultrasonic power density and processing time influences in the extraction of different chlorogenic acid, and that different extraction conditions can be used to selectively extract specific caffeoylquinic acids and feruloylquinic acids in higher amounts. Ultrasound promoted the hydrolysis of tricaffeoylquinic acid when subjected to ultrasonic waves (20-50W/L), and of 3,4-caffeyolquinic acid at high ultrasonic power density (50W/L).

Effect of Ultrasonic Treatment on Grain Structure, Eutectic Phase and Mechanical Properties of an Al–6.2 wt% Cu Alloy

The microstructural modification of eutectic phase is a crucial factor for the mechanical properties strengthening of the Al–Cu binary alloy. In this paper, Al–6.2% Cu melts were subjected to ultrasonic treatment from 710 or 660 °C with different durations. The microstructural evolutions of primary α-Al grains and α-Al + θ-Al2Cu eutectic phase under ultrasonication were investigated based on the nucleation and growth behavior. Results indicated that with the increase of ultrasonic processing time, the growth of dendritic or petaloid grains were completely suppressed and noticeable refinement to globular morphology were observed for α-Al grains. Meanwhile, broad lamella-like eutectic structure transformed to debris or even particles with continuous ultrasonication. Accordingly, the area fraction, average length and width of coarsening eutectic lamellas were dramatically reduced. In addition, the decrease of coarsening eutectic phase rather than the refinement of α-Al grains was found to be the main contributor to the enhancement of mechanical properties for Al–6.2% Cu alloy. The mechanisms underlying the transformation of eutectic phase under ultrasonic treatment was also interpreted based on the experimental results.

Non-Fourier heat conduction in oil-in-water emulsions

Emulsions have widely been used in various application, e.g. in energy system as a potential second refrigerant. However, there is a lack of comprehensive study on extraordinary effective thermal conductivity enhancement in the oil-in-water (O/W) emulsions, and effects of temperature and droplet size were not considered in the widely used models of effective thermal conductivity for the O/W emulsions. In this study, non-Fourier heat conduction characteristics in the O/W emulsions were investigated experimentally. The O/W emulsions were prepared with different droplet sizes by controlling the ultrasonic processing time. The O/W emulsions containing small droplets are stable. Effective thermal conductivity of O/W emulsions nonlinearly varies with droplet size, concentration, fluid properties and temperature. Small droplet size is beneficial for effective thermal conductivity enhancement of O/W emulsions. Thermal conductivity of fluids can be enhanced significantly especially at low concentration although thermal conductivity of oil is much lower than water conductivity, which could be due to non-Fourier heat conductions in O/W emulsions. Time lag ratio less than 1 indicates that no thermal waves exist in O/W emulsions, and diffusion-dominant non-Fourier heat conduction could exist in the O/W emulsions. A new model of effective thermal conductivity, which considers effects of fluid thermosphysical properties, oil concentration, droplet size and temperature, was developed for the O/W emulsions based on the measured data. This study could be helpful for exploring the mechanisms behind extraordinary heat conductivity enhancement phenomena of oil-in-water emulsions.

Single-stage ultrasound-assisted process to extract and convert α-solanine and α-chaconine from potato peels into β-solanine and β-chaconine

Potato peels are rich in α-solanine and α-chaconine, which are glycoalkaloids with known pharmacological activity but that have high cytotoxicity. Their aglycones (β-solanine and β-chaconine) have the same pharmacological activity but with a much lower cytotoxicity. In this work, we applied ultrasound technology to extract α-solanine and α-chaconine from potato peel and at the same time convert these molecules into β-solanine and β-chaconine, in a single-stage process without resorting to organic solvents. The extraction was studied varying ultrasonic power density (20, 35, and 50 W/L) and processing time (5, 10, 20, and 40 min) using an ultrasonic bath operating at 25 kHz. The chemical analysis was done by UHPLC-qTOF-MS and the results were evaluated by HCA, PCA, and PLS-DA chemometric analysis. The analysis of the single-stage procedure pointed to the viability of concomitant extraction and chemical conversion of α-solanine and α-chaconine into β-solanine and β-chaconine when operating at an ultrasonic power density of 35 and 50 W/L and subjecting the potato peel power to 20 and 40 min of ultrasound.

Improvements on the Stability and Vitamin Content of Acerola Juice Obtained by Ultrasonic Processing.

This work has examined the influence of ultrasonic processing on acerola juice and its influence in the stability of the juice and in the availability of vitamins B, C, E, and pro-vitamin A. The study has evaluated the changes in these quality parameters resulting from changes on ultrasonic power density, processing time and temperature. Ultrasound application increased the availability of pro-vitamin A and vitamins B3, B5, C and E in the juice by releasing them from the apoenzymes to which they are bound and by improving the homogeneity of the juice. The retention of the major vitamins in acerola juice (vitamins A and C) was higher when lower temperatures (10 to 20 °C) and mild ultrasound power density (2000 to 3000 W/L) were applied.

Improvement of Tensile Behaviour of Tin Babbitt by Reinforcing with Nano Ilmenite and its Optimisation by using Response Surface Methodology

Metal Matrix Nanocomposites are made from conventional materials and alloys as matrix materials and had become prominent in improving the mechanical behaviour. In this paper, the authors have fabricated a Tin Babbitt particulate metal matrix nanocomposite reinforced with Ilmenite (FeTiO3). For systematic understanding or effect of processing parameters on the tensile behaviour, the central composite design of response surface methodology was used. Metal matrix nanocomposite was fabricated by using ultrasonic assisted stir casting technique. Stirring time, ultrasonic processing time, Wt.% of nanoparticles were taken as processing parameters. The objective of the work is to improve the tensile behaviour of Tin Babbitt and understand the effect of processing parameters on the tensile strength of the Tin Babbitt metal matrix nanocomposite and then optimise it for maximum tensile strength. It was found that tensile strength was improved due to the nano reinforcement.

Influence of ultrasonic vibrations on process performance of electrochemical honing

Electrochemical honing (ECH) is a novel variant of hybrid machining processes (HMPs). The key feature is that the distinct coupling of electrochemical machining (ECM) and honing provide a controlled functional surface generation and faster material removal rate in a single operation. In the present study, the influence of ultrasonic vibrations on process performance of ECH of bevel gears made of EN8 is investigated. An analysis of the process has been presented with suitable illustrations. Ultrasonic frequency and processing time were considered as the input variables while improvement in surface finish, material removal and geometrical accuracies were considered as the monitored output. The effectiveness of the process was investigated through experimental trials by conducting a comparison study between classical ECH and ultrasonic vibration-assisted ECH (UECH). The results confirm that improvements in surface roughness and martial removal rate are significantly higher than those obtained with classical ECH. The study further reveals that the scrubbing of the oxide layer is easier to be achieved and surface quality is obviously improved due to ultrasonic vibrations. The experimental results demonstrate that UECH gives 18.36 % improvement in average roughness, 9.31 % improvement in maximum roughness and 20 % improvement in material removal rate as compared with ECH.