Ultrasonic Power Research Articles

Study on 13C MultiCP/MAS ssNMR Analysis of Tobacco Pectin

Background: As one of the most important economic crops, tobacco products have a long history and dominate the development of the world economy. Pectin, as a complex colloidal substance widely present in plant cell walls, its content is an important factor affecting the safety of tobacco smoking. Objective: This study aimed to analyze the content and structure of pectin in tobacco samples Methods: In this study, tobacco pectin was extracted by ultrasonic-assisted ionic liquid extraction, and the 13C MultiCP/MAS NMR spectral analysis of pectin was conducted. Results: The type of extractant, duration of ultrasonication, extraction temperature, and solid-liquid ratio were optimized. Under the conditions of using 1-Butyl-3-methylimidazolium tetrafluoroborate ([Bmim]BF4) as the extractant, the solid-liquid ratio of 1:20 g/mL, and the ultrasonic power of 600 w for 30 min at 30°C, the yield of 23.7% of tobacco stem pectin and the purity of 54.2% could be obtained. The optimized MultiCP sequence parameters, with 10 CP cycles of 1.0 ms and the repolarization time of 50 ms could obtain high-resolution spectra within a time of 1.0 h. The C-6 peaks of the pectin in spectra were fitted using the spectral deconvolution technique and calculated the methylesterification (DM) of the tobacco pectin, which was generally less than 50% and belonged to the low methyl esterification pectin. The pectin content of the tobacco sample was calculated using the standard curve method with the addition of dimethyl sulfone (DMS) as an internal reference. The results of this method were consistent with the colorimetric method. Conclusion: The 13C MultiCP/MAS NMR method has the advantages of being green, fast, and accurate and provides a new technical tool for quantitative and qualitative studies of cell wall substances in tobacco samples.

Enhancing Antioxidant Activity from Aquatic Plant Cymodocea nodosa for Cosmetic Formulation Through Optimized Ultrasound-Assisted Extraction Using Response Surface Methodology

This study aimed to enhance antioxidant extraction from the aquatic plant Cymodocea nodosa for cosmetic formulation through optimized ultrasound-assisted extraction using response surface methodology. The optimized conditions—30 min of extraction time, 30% ultrasonic power, and 25% hydro-ethanolic solvent—resulted in a high total phenolic content of 113.07 mg EAG/g DM and antioxidant activity of 67.02%. Chromatographic analysis revealed a rich profile of phenolic compounds, including sinapic acid (0.741 mg/g), myricetin (0.62 mg/g), and quercetin-3-O-rutinoside (0.3 mg/g), demonstrating the extract’s potent therapeutic properties. While the extract exhibited limited anti-inflammatory activity, it showed no cytotoxic effects on RAW 267.4 cells, ensuring its safety for cosmetic applications. The formulated cream maintained stable pH (6.58 to 6.6), consistent viscosity (5966.38 to 5980.6 cp), and minimal color changes over a 30-day period, indicating robust stability across various temperatures (4 °C, 25 °C, and 40 °C). These results confirm the potential of C. nodosa extracts to develop effective, stable, and eco-friendly cosmetic products, offering substantial benefits for skin health and emphasizing the importance of sustainable extraction processes in the cosmetics industry.

Performance evaluation of ultrasonic-assisted dynamic ice melting in ice storage systems: An experimental study

This study presents the construction of an ice storage tank equipped with an internal ice-on-coil system. The cooling performance of the ice storage system is enhanced by utilizing the cavitation phenomenon induced by ultrasonic vibration in water. Active water circulation and spraying within the tank enhance cooling efficiency by promoting uniform temperature distribution. An analysis is conducted on the impact of various operating parameters, such as output powers of 200 W, 400 W, and 584 W, frequencies of 40 kHz, 80 kHz, and 120 kHz, and three different placements of the oscillator, on the cooling performance of ultrasonic-assisted static ice melting, dynamic ice melting, and ultrasonic-assisted dynamic ice melting systems. Ultrasonic-assisted static ice melting refers to ice melting with stationary water, while ultrasonic-assisted dynamic ice melting involves water circulation, enhancing heat transfer. The study examines performance indicators like instantaneous cooling rate, cumulative cooling capacity, average cooling rate, melting time, and heat gain by the system. The findings indicate that higher ultrasonic power levels enhance the average cooling rate and reduce the melting time by approximately 50 % and 32.2 %, respectively. However, the frequency does not have a significant effect on the cooling performance. In addition, the ice storage system had a significant increase in cooling rate of 294.87 % when utilizing the ultrasonic-assisted dynamic ice melting system. Furthermore, the melting time was lowered by 71 % in comparison to the static ice melting method. Of all the parameters, the power parameter has the greatest impact. The impact of the ultrasonic oscillator placement parameter is secondary, while the influence of the frequency parameter on the cooling performance is not significant.

Optimization of White Tea Flavanol Extraction Process by the Ultrasonic‐Assisted Deep Eutectic Solvent Method and Determination of the Antioxidant and Antibacterial Activity

ABSTRACTFlavanols have a variety of health benefits and biological activities and become the hotspot of the food development and research. In this research, flavanols were extracted from white tea by ultrasonic‐assisted deep eutectic solvent (DES) method. High‐performance liquid chromatography was used to determine the content of flavanols. The influence of four factors on the flavanol extraction yield was analyzed by single factor experiments, including deep eutectic solvent mole ratio (the mole of hydrogen bond acceptors: the mole of hydrogen bond donors), solid–liquid ratio (white tea sample weight/g: the volume of DES/mL), extraction time and extraction temperature. On the basis of single factor experiments, the factors which had significant effects on the flavanol extraction yield were further optimized by the response surface test. The results showed that the optimized extraction conditions were as follows: the mole ratio of DES 1: 4 (choline chloride: 1,2‐propanediol), the solid–liquid ratio 1:30, the extraction temperature 56°C, the extraction time 53 min, and the ultrasonic power 341 W. Under the above parameters, the extraction yield of white tea flavanols was 9.63 mg/g. After purification with macroporous resin, antioxidation and antibacterial experiments were carried out. The results showed that the antioxidant and antibacterial effects of white tea flavanols were remarkable. The antibacterial effects performed best on Escherichia coli, followed by Bacillus subtilis and Staphylococcus aureus. The maximum diameter of the antibacterial zone on Escherichia coli was 0.95 ± 0.11 mm. The best radical scavenging rates of OH, ABTS+ and DPPH were 97.1%, 97.5%, and 88.4%, respectively, when the flavanol concentration was 9.5 mg/mL. The conclusions of this research can provide theoretical foundation for the further study of white tea flavanols.

Influence of ultrasonic assistance on the microstructure and friction properties of laser cladded Ni60/WC composite coatings

The effects of different ultrasonic vibration powers on the distribution, phase structure, friction and wear properties of WC reinforced particles in laser melted Ni60/WC composite coatings are investigated. The effects of ultrasonic vibration on the microstructure, elemental distribution, crystal orientation, friction and wear properties of the fused coatings are analyzed. The experimental results show that the deposition of WC particles in the lower and middle parts of the coating is significantly improved after the introduction of ultrasonic vibration during the fusion cladding process. In particular, at 600 W ultrasonic power, not only the distribution uniformity of tungsten carbide particles in the coating is optimal, but also the composite coating shows better wear resistance. However, too much ultrasonic power increases the possibility of particle agglomeration. In addition, although the phase pattern of the coating does not change after ultrasonic vibration, the width of the columnar crystalline region of the coating is reduced, and the coating is covered by a homogeneous lamellar nanoscale eutectic structure with the phase compositions of the γ-(Fe, Ni) and M23C6 phases. The ultrasonic vibration improves elemental segregation of the coating, reduces the large number of precipitated phases in the coating, weakens the grain growth orientation, and relieves the local stress concentration in the coating. In addition, the mechanism of the influence of WC particles on the microstructure evolution and wear resistance of the composite coatings is discussed.

Study of the effect of ultrasonic technology on the extraction of bitumen from bituminous rocks

Background: Nowadays, there are few studies focused on the extraction of targeted products from bituminous rocks. Published research on the on the use of ultrasound for bitumen extraction refers to unconventional technologies. A distinctive feature of the bituminous rocks under study is their exposure at the surface, where they are situated in open areas. Due to various technogenic factors and prolonged atmospheric, light fractions are lost, while the heavier components undergo oxidation. These processes lead to the formation of heavy oils and hard bitumens with complex composition. Aim: To study the effect of ultrasonic technology on the bitumen extraction of from bituminous rocks and to determine the physical and chemical properties of the product obtained. Materials and methods: Thу ultrasonic method has many benefits, in particular energy and water savings, high productivity within a short period of time, and possibility of organizing a mobile unit installation at the production site. The main process parameters includes the determination of the required frequency and power depending on the object of ultrasound technology research. The results of the work have demonstrated that ultrasonic cavitation of bituminous rocks in an alkaline medium increases the degree of bitumen extraction. Results: The physical and chemical properties of bitumen obtained as a result of studying the effect of ultrasonic technology on bitumen extraction from oil-bituminous rocks were determined. Conclusion: The study identified the optimal process parameters based on the specific research object. When selecting the ultrasonic power it was found that clay compounds of bituminous rocks have a direct effect on the extraction of natural bitumen. It was demonstrated that ultrasound technology is a promising and industrially applicable technology for extracting bitumen from the bituminous rocks of the Munaily Mola field.

Optimization of Ultrasonic Extraction, Functional Properties, and Antioxidant Activity of Naematelia aurantialba Polysaccharides

AbstractNaematelia aurantialba (N. aurantialba) is a fungus rich in polysaccharides with medicinal and edible properties. Polysaccharides are the main active components of N. aurantialba; however, their biological activities and functional properties have not been widely explored. In this study, the ultrasonic extraction process for N. aurantialba polysaccharides (NAP) is optimized, and the physicochemical, functional, and antioxidant activities of the homogeneous fraction (NAP) are investigated. The optimal extraction conditions are a liquid–solid ratio of 50 mL g−1, ultrasonic power of 430 W, ultrasonic time of 32 min, resulting in an extraction rate of N. aurantialba polysaccharides of 48.68% ± 0.83%. NAP has a molecular weight of 915 kDa. The monosaccharide composition of NAP is as follows: mannose (59.04% ± 0.12%), xylose (23.89% ± 0.03%), glucuronic acid (14.07% ± 0.24%), galacturonic acid (2.12% ± 0.02%), and glucose (0.76% ± 0.02%). NAP exhibites water and oil retention capacities of 14.62 ± 0.25 g g−1 and 23.73 ± 0.85 g g−1, respectively. Furthermore, NAP demonstrates favorable moisture absorption and retention properties. The results show that NAP has a significantly stronger antioxidant effect, as demonstrated by its concentration‐dependent scavenging of ABTS, DPPH, and hydroxyl radicals.

Recovery of Selenium-Enriched Polysaccharides from Cardamine violifolia Residues: Comparison on Structure and Antioxidant Activity by Different Extraction Methods.

The residues from selenium-enriched Cardamine violifolia after the extraction of protein were still rich in polysaccharides. Thus, the recovery of selenium polysaccharides (SePSs) was compared using hot water extraction and ultrasonic-assisted extraction techniques. The yield, extraction rate, purity, specific energy consumption, and content of total and organic selenium from different SePS extracts were determined. The results indicated that at conditions of 250 W (ultrasonic power), 30 °C, and a liquid-to-material ratio of 30:1 extracted for 60 min, the yield of SePSs was 3.97 ± 0.07%, the extraction rate was 22.76 ± 0.40%, and the purity was 65.56 ± 0.35%, while the total and organic selenium content was 749.16 ± 6.91 mg/kg and 628.37 ± 5.93 mg/kg, respectively. Compared to traditional hot water extraction, ultrasonic-assisted extraction significantly improves efficiency, reduces energy use, and boosts both total and organic selenium content in the extract. Measurements of particle size, molecular weight, and monosaccharide composition, along with infrared and ultraviolet spectroscopy, revealed that ultrasonic-assisted extraction breaks down long-chain structures, decreases particle size, and changes monosaccharide composition in SePSs, leading to lower molecular weight and reduced dispersity. The unique structure of SePSs, which integrates selenium with polysaccharide groups, results in markedly improved antioxidant activity and reducing power, even at low concentrations, due to the synergistic effects of selenium and polysaccharides. This study establishes a basis for using SePSs in functional foods.

Optimization of Ultrasound-Assisted Enzymatic Extraction Conditions on Yield, DPPH Antioxidant Activity, and Gel Strength of Agar from Gracilaria fisheri

ABSTRACT This study investigated the effect of ultrasound-assisted enzymatic extraction (UAEE) conditions: solid-to-water ratio (1:50–1:100), ultrasonic power (296–506 W), and temperature (40–60°C) on key criteria (responses) of Gracilaria fisheri agar. Response surface methodology resulted in accurate quadratic models for predicting responses. Non-linear (quadratic and interaction) effects of UAEE conditions significantly (p < 0.05) influenced the responses. Optimal conditions (solid-to-water ratio of 1:98, ultrasonic power of 506 W, and temperature of 60°C) produced 32.02% agar yield, 58.05% DPPH antioxidant activity, and 83.48 g/cm2 gel strength, aligning with predictions. This research establishes an efficient agar extraction method with controllable qualities from red seaweed.

Comparison and Optimization of Three Extraction Methods for Epimedium polysaccharides

Epimedium is used in traditional Chinese medicine. Epimedium polysaccharides have a variety of physiological properties. This study compared three different processes for the extraction of polysaccharides from Epimedium spp., including ultrasonic, aqueous enzymatic, and microwave extraction, to optimize the extraction conditions and determine the optimal extraction method. The optimal parameters for each method were analyzed. The results showed that the optimal process for ultrasonic extraction was an ultrasonic power of 250 W, an extraction time of 60 min, a temperature of 50 °C, and a solid–liquid ratio of 1:35. The optimal conditions for the aqueous enzymatic method were a papain concentration of 70 U/mL, extraction time of 70 min, a temperature of 50 °C, and a material-to-liquid ratio of 1:30, while those for microwave extraction were a microwave power of 650 W, an extraction time of 50 min, a temperature of 40 °C, and a material-to-liquid ratio of 1:25. The polysaccharide yields were 4.85%, 4.72%, and 3.98% for the three methods, respectively, indicating that ultrasonic extraction resulted in the highest yield of polysaccharides from Epimedium brevicornum. After purification with DEAE-cellulose, the polysaccharide yields were 4.13%, 3.67%, and 3.12%, respectively. A comprehensive comparison demonstrated the superiority of the ultrasonic extraction method in terms of both extraction yield and purification efficiency. Characterization of the extracted Epimedium polysaccharides showed the presence of five monosaccharides, i.e., glucose, galactose, mannose, galacturonic acid, and rhamnose, and a number average molecular weight Mn of 1.65 × 105 Da and weight average molecular weight Mw of 6.61 × 105 Da. These results provide a scientific basis for the in-depth study and application of Epimedium polysaccharides.

Corneal Clarity after Phacoemulsification: Nuclear Management by Stop and Chop vs Divide and Conquer Methods

Background: Restoration of effective vision is the principal aim of all modalities of cataract surgery including Phacoemulsification. Energy level of ultrasonic power in Phacoemulsification and turbulence of fluid in the anterior chamber plays an important role in corneal endothelial cell loss influencing post-operative corneal clarity. Objectives: To compare post-operative corneal clarity after Phacoemulsification by two techniques of nuclear divisions: stop and chop with divide and conquer. Methodology: This prospective observational study was conducted at Shaheed Monsur Ali Medical College and Hospital, Uttara, Dhaka from January, 2023 to June, 2023. The study was carried out on 30 outdoor patients undergoing Phacoemulsification at SMAMCH and Mirpur Eye Hospital, Dhaka. The selected patients underwent detailed ocular and systemic examinations with relevant investigations and divided equally into two groups comprising of 15 in group A (stop and chop) and 15 in group B (divide and conquer). Phacoemulsification was done in all patients by a single expert surgeon. Patients were followed up after 1 week, 4 weeks and 12 weeks of surgery. Corneal endothelial cell count and central corneal thickness were assessed in each visit. Mean value of these mentioned parameters in follow-up periods were compared between two groups. Unpaired t test was done to assess the level of significance. Results: The mean age + standard deviation (SD) of the study subjects was 61.5+2 years, out of which 13(43.33%) were males and other 17(56.67%) females. Pre-operative value of mean endothelial cell count was 2620+70.20/mm2 in group A and 2625+71.10/mm2 in group B. Postoperative mean value + SD of endothelial cell count was 2420+68.90/mm2, 2345+66.64/mm2, 2310+66.04/mm2 respectively after 1 week, 4 weeks and 12 weeks of surgery in group A and 2410+69.54/mm2, 2340 +6587/mm2, 2310+64.45/mm2 in group B respectively. Mean value + SD of central corneal thickness was 545+40.50 micrometer, 535+40.02 micrometer and 532+39.85 micrometer respectively after 1 week, 4 weeks and 12 weeks after surgery in group A and 547+43.98 micrometer, 537+41.23 micrometer and 533+40.63 micrometer respectively in group B. Conclusion: Quantitative assessment and comparison of endothelial cell count and central corneal thickness shows that at end of the study, there was no remarkable difference in mean values of endothelial cell count and central corneal thickness between two methods. Journal of Monno Medical College December, 2023; 9 (2):37-40

Zr-based MOF as a support for lipase immobilization to enhance enzymatic transesterification for biodiesel production

The development of novel biocatalysts is essential to promote the commercialization of biodiesel production by transesterification reaction. In this paper, Rhizopus oryzae lipase (ROL) was immobilized on an amino-functionalized zirconium-based metal organoskeleton by interfacial adsorption. The immobilization conditions were optimized and the enzymatic properties were tested, and the resulting novel biocatalysts exhibited higher stability and heat resistance. SEM, XRD and BET analyses were used to characterize the biocatalysts and carrier materials. The catalytic performance of ROL@UiO-66-NH2 in the production of biodiesel by transesterification reaction was explored, and the production process was optimized by response surface method. The results showed that the conversion rate of FAEE reached 82.05% at molar ratio of ethanol/oil of 15.43:1, reaction temperature of 50.28°C, reaction time of 120.9 min, DES addition of 48.08 wt%, biocatalyst addition of 3 wt%, and ultrasonic power of 90 W. In addition, ROL@UiO-66-NH2 demonstrated good recyclability, with the catalytic efficiency remaining at 71.87% after five cycles.

Green and efficient extraction of an anticaner agent N-methylsansalvamide using ultrasound-assisted deep eutectic solvents from mycelia of strain Frusarium sp. R1

N-methylsansalvamide (SA), one of cyclic pentadepsipeptides produced by several Fusarium strains, is a promising therapeutic agent for the treatment of cancer disease. In order to make sufficient amount of SA for drug development, a green and efficient extraction process of SA from the mycelia of strain Fusarium sp. R1 using deep eutectic solvent-assisted ultrasound extraction (DES-UAE) was firstly achieved in this work. Solvent screening results indicated that choline chloride-acetic acid (ChCl-Aa) was shown to be the best DES for SA extraction. Through single-factor trials, Plackett-Burman design (PBD) and BoxBehnken design (BBD) experiments, the optimal conditions for DES-UAE with the highest SA yield of 58.2 ± 1.1 mg/g were obtained as follows: ChCl-Aa ratio of 1:2.0 (M/M), water content of 16.4 %, liquid-solid ratio of 37:1 (mL/g), ultrasonic power of 175 W for 47.4 min at 46.3 °C. Compared to conventional extraction approaches, DES-UAE exhibited better SA yield since it caused more serious damage to the surface of mycelia powder on basis of scanning electron microscopy (SEM) analysis. Furthermore, molecular interaction studies suggested that SA has a variety of interactions with ChCl-Aa, including hydrogen and electrovalent bonds as well as van der Waals forces. Finally, the recovery rate of SA reached up to 99.5 % when the ratio of distilled water and DES extracts was 15:1 (V/V). These findings provide the way for large-scale production of SA.

Polyphenol composition and antioxidant activity of fermentation combined with enzymatic hydrolysis modified Astragalus membranaceus stems

Astragalus membranaceus (AM) roots are a well-known homologous medicine and food in China. AM stems, which are discarded and not used effectively, also contain many active compounds and exhibit beneficial effects. It has the potential to be explored as antibiotic alternative. Fermentation combined with enzymatic hydrolysis (FEH) is an effective strategy for extracting polyphenol and improving the usage of AM stems. Therefore, in this study, the conditions of FEH and extraction for polyphenol in AM stems were screened. The antioxidant activity of extract from AM stems without and with FEH (AMSE and FAMSE) was evaluated. The metabolite profiles of phenolic acids and flavonoids in AMSE and FAMSE were characterized by ultra-performance liquid chromatography coupled with electrospray ionization tandem mass spectrometry (UPLC–ESI-MS/MS). The results showed that the highest polyphenol content from AM stems was obtained with cellulase and pectinase (1:1, 2000 U/g), moisture content 43%, fermentation temperature 30 °C, and fermentation time 7 days. Selected extraction conditions of polyphenol were ethanol concentration 50%, ultrasonic power 500 W, extraction temperature 35 °C, and extraction time 40 min. On this condition, compared with AMSE, the polyphenol and flavonoid contents in FAMSE were significantly higher. FAMSE exhibited stronger DPPH, hydroxyl radical scavenging rate and reducing power than AMSE. The relative content of 3-(4-hydroxyphenyl)-propionic acid, dihydroferulic acid, isoferulic acid, 4-hydroxybenzoic acid, 4-hydroxyphenyllactic acid, ferulic acid, vanillic acid, syringic acid, gentisic acid, sinapic acid, apigenin, tricin, acacetin, daidzein, genistein, formononetin, prunetin, pratensein, rhamnocitrin and galangin were significantly upregulated in FAMSE.Graphical

Application of machine learning in ultrasonic pretreatment of sewage sludge: Prediction and optimization

In this research, typical industrial scenarios were analyzed optimized by machine learning algorithms, which fills the gap of massive data and industrial requirements in ultrasonic sludge treatment. Principal component analysis showed that the ultrasonic density and ultrasonic time were positively correlated with soluble chemical oxygen demand (SCOD), total nitrogen (TN), and total phosphorus (TP). Within five machine learning models, the best model for SCOD prediction was XG-boost (R2 = 0.855), while RF was the best for TN and TP (R2 = 0.974 and 0.957, respectively). In addition, SHAP indicated that the importance feature for SCOD, TN, and TP was ultrasonic time, and sludge concentration, respectively. Finally, the typical industrial scenario of ultrasonic pretreatment of sludge was analyzed. In the secondary sludge, treatment volume at 0.6 L, the pH at 7.0, and the ultrasonic time at 20 min was best to improve the SCOD. In the ultrasonic pretreatment primary sludge, treatment volume of 0.3 L, pH of 7.0, and ultrasonic time of 15 min was best to improve the SCOD. Furthermore, the ultrasonic power at 700 W and ultrasonic time at 20 min were best to improve the C/N and C/P in the secondary sludge. In the primary sludge, the ultrasonic power at 600 W, and the ultrasonic time at 15 min were best to improve C/N and C/P. This study lays a foundation for the practical application of ultrasonic pretreatment of sludge and provides basic information for typical industrial scenarios.

Optimization of the preparation process of Spirulina blended liquor and Spirulina fermented wine, analysis of volatile components and in vitro antioxidant study.

The optimal conditions were explored for the preparation of Spirulina blended liquor (SBL) and Spirulina fermented wine (SFW), respectively. The parameters obtaining highest alga polysaccharide were calculated by response surface methodology. The optimal conditions for SBL preparation were base liquor of 42%vol, ultrasonication time of 37-min and ultrasonic power of 80W with polysaccharide content (PC) and alcohol content (AC) of 0.2181g/L and 39.7%vol, respectively. In the case of SFW, optimum fermentation occurred at 22°C, with a 4% inoculum and 6-day period with PC and AC of 8.533g/L and 11.2%vol, respectively. Headspace solid-phase microextraction-gas chromatography-mass spectrometry was used to quantitatively analyze the volatile components of SBL and SFW. There were 32 and 40 main aroma compounds in SBL and SFW, respectively. Volatile organic compounds, including α-ionone and β-ionone, produced by Spirulina were detected in both SBL and SFW. Comparative evaluation of scavenging activity and total reducing power revealed the antioxidant capacity of SFW significantly outperformed that of SBL.

Sound absorption coefficient in the audible and ultrasonic frequency range measured in a reverberation chamber with an omnidirectional parametric loudspeaker

An omnidirectional parametric loudspeaker (OPL) is a sound source that contains hundreds of ultrasonic transducers set on the surface of a sphere. Each transducer emits an ultrasonic collimated beam consisting of an audible exponential sweep sine (ESS) modulated in amplitude. This results in hundreds of ultrasonic sound waves emitted in all directions, but also audible sound waves generated by the parametric acoustic array (PAA) phenomenon, by which a modulated signal returns to the audible range thanks to nonlinear propagation in the air. This work examines how the OPL performs in assessing room acoustics, specifically in determining material sound absorption coefficients within reverberation chambers. The ISO 354 standard requires measuring reverberation times with the chamber empty and with the material sample. These are measured using ESS, which has proven effective for the OPL performance. This signal concentrates all the sound power into a single frequency, which improves ultrasonic power levels and thus the signal-to-noise ratio of the audible sound field. The absorption coefficient is next evaluated following the standard, and the results are compared with those obtained using a standard dodecahedral loudspeaker. Finally, the absorption coefficient in the ultrasonic range is examined to evaluate the OPL performance in this frequency range.

Effect of ultrasonic rapid thawing on the quality of frozen pork and numerical simulation

Different ultrasonic power densities have positive implications for thawing frozen pork. This study investigated the effects of a 20 kHz ultrasonic frequency and different ultrasonic power densities (0, 10, 20, 27, 33, and 40 W/L) on the thawing loss, color, texture, pH value, and TBARS value of thawed frozen pork. It was found that ultrasonic rapid thawing significantly reduced the thawing time of frozen pork, with the shortest thawing time observed at an ultrasonic power density of 40 W/L, resulting in a 68.8% reduction in thawing time compared to static water thawing without ultrasonic treatment, and a 14.8% improvement in tenderness. When the ultrasonic power density exceeded 10 W/L, there were no significant differences in thawing loss, cooking loss, texture, color, pH value, and TBARS value of frozen pork compared to fresh pork. A numerical model of the acousto-thermal coupling of ultrasonic rapid thawing of frozen pork was also established in this study. The ultrasonic amplitude of the thawing process was visualized through numerical calculations. The predicted thawing time and thawing temperature of ultrasonic thawing showed a high degree of fit with experimental values. The average deviation (AD) of thawing time and temperature was 0.19–0.36 °C and 10–70 s. The root mean square error (RMSE) of thawing temperature was 0.09–0.32.

Sustainable ferritin from bovine by-product liver as a potential resource: Ultrasound assisted extraction and physicochemical, structural, functional, and stable analysis

Ferritin is an iron-containing protein that is widely present in all organisms and has the function of regulating the metabolic balance of iron in organisms. It can be separated from animal by-product tissues and converted into value-added components to promote the development of a circular economy. This study established a method for extracting bovine liver ferritin (BLFer) using ultrasound-assisted buffer system. The optimal extraction conditions were determined through single factor and response surface optimization experiments as follows: ultrasound temperature of 70 °C, extraction time of 25 min, ultrasonic power of 400 W and solvent-to-solid ratio of 2 mL/g, the experimental value of the ferritin yield was 32.18 ± 0.12 g/kg. Compared with traditional methods, Ultrasound-assisted extraction improved the ferritin yield and enhanced its structural stability. Bioinformatics analysis revealed that BLFer is a hydrophilic protein with strong thermal stability. The BLFer has a ferrous oxidase active center, which plays an important role in the oxidative precipitation and reductive release of iron. It can dissociate under strong acids or bases but maintains good stability after heat treatment. These findings will help improve the comprehensive utilization of animal by-products, and promote the potential application of animal by-product ferritin in food and other industries.

Effects of ultrasound power on properties of Cu-doped fluorohydroxyapatite coatings prepared via ultrasonic-assisted electrodeposition for biomedical applications

The Cu -doped fluorohydroxyapatite (Cu-FHAp) coating's combination of beneficial properties, including biocompatibility, corrosion resistance, and antibacterial effects, makes it a promising choice for coating magnesium alloys, particularly for biomedical implant applications. Electrodeposition under ultrasonic agitation is a method used for the synthesis of Cu-FHAp coatings, where the ultrasonic power is an important parameter that can affect the coating quality and performance. This study aimed to investigate the effect of ultrasonic power (0, 10, and 50 W) on various properties of the Cu-FHAp coating electrodeposited onto AZ31 alloy. Microstructural analysis confirmed the successful formation of Cu-doped FHAp bioceramic on the substrate using this method. The results indicated that the use of ultrasonication produced a more uniform coating structure, reducing surface roughness up to 39 % and improving hydrophilicity up to 65 %. Moreover, increasing the ultrasonic power from 10 to 50 W led to a reduction in coating thickness and also enhanced corrosion resistance due to the higher density of the Cu-doped FHAp coating. Biological assessments demonstrated favorable cell adhesion to the coated alloy, indicating the potential of the synthesized Cu-doped FHAp coatings for biomedical applications.