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Purpose: This study investigated the magnitude, direction, and temporal aspects of the force applied during instrumentation with a piezoelectric ultrasonic periodontal scaler, compared this force with recommendations in the literature, and assessed the influence of the profession (dentist or dental hygienist) and calculus hardness. Materials and Methods: The force applied by ten dental hygienists and six dentists during debridement of comparatively soft and hard artificial dental calculus with a piezoelectric ultrasonic scaler was recorded in-vitro. The total force and its components in three axes were statistically analysed. Results: During debridement of soft artificial dental calculus, the mean total force applied by dental hygienists was 0.34 N (± 0.18 N, range: 0.13 N to 0.59 N) and by dentists 0.28 N (± 0.33 N, range: 0.06 N to 0.95 N), and the total force exceeded 0.5 N approximately 23% and 14% of the time for dental hygienists and dentists, respectively. During debridement of hard artificial dental calculus, the mean total force applied by dental hygienists was 0.63 N (± 0.40 N, range: 0.28 N to 1.64 N) and by dentists 0.57 N (± 0.17 N, range: 0.34 N to 0.76 N); the total force exceeded 0.5 N more than half of the time for both professions. On average, dental hygienists applied 1.85x (p = 0.04) and dentists 2.04x (p = 0.06) higher force on hard than on soft artificial calculus. However, dental hygienists and dentists used similar forces during the debridement of both hard (p = 1.00) and soft (p = 0.26) calculus. Conclusion: The force applied during the debridement of hard artificial dental calculus was statistically significantly higher than during the debridement of soft artificial dental calculus. No statistically significant difference between dentists and dental hygienists was found. The force applied by both groups on soft and hard artificial dental calculus frequently exceeded recommended values. [ABSTRACT FROM AUTHOR]

Purpose: Traditional fasting causes considerable discomfort without added assurance of security, whereas oral carbohydrate beverage offers an alternative to improve medical experience. This study aims to explore the impact of different types and dosages of oral fluids loading before painless bidirectional endoscopy on the gastric emptying and wellbeing. Methods: 180 patients arranged for bidirectional endoscopy with intravenous anesthesia were randomized: patients in the control group (Group C) obeyed standard fasting; the 200 mL carbohydrate group (Group P1), 400 mL carbohydrate group (Group P2), 200 mL water group (Group W1) and 400 mL water group (Group W2) respectively consumed 200 mL or 400 mL corresponding clear liquids 2 h before the procedure. Gastric emptying metrics under ultrasound, subjective comfort indexes, periprocedural blood glucose and vital signs were contrasted among the groups. Results: No significant differences were detected in the gastric emptying including CSA (cross-sectional area), GV (gastric volume), cGV (corrected gastric volume) and the three-point grading system among groups, and none had a cGV > 1.5 mL/kg before anesthesia. Participants in Group P2 experienced less preprocedural thirst and mouth dryness, so as the postprocedural thirst, mouth dryness and hunger. Periprocedural blood glucose and MAP had the similar trend in all groups. The occurrence of hypotension, bradycardia, hypoxia, and the required norepinephrine was comparable among the groups. Conclusions: Oral beverage loading with 200 mL or 400 mL can be safely applicated 2 h before painless bidirectional endoscopy without increasing the gastric volume. 400 mL carbohydrate solution effectively relieves the discomfort and could serve as a consideration. Trial registration: Registered in the Chinese Clinical Trial Registry on December 5, 2023 (ChiCTR2300078319). [ABSTRACT FROM AUTHOR]

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

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

The appropriate understanding and formulation of rock discontinuities via FEM is still challenging for rock engineering, as continuous algorithms cannot handle the discontinuities in rock mass. Also, different failure modes of rock samples, containing tensile and shear failure, need to be computed separately. In this study, a novel double-phase field damage model was introduced with two independent phase field damage variables. The construction of the proposed model follows the thermodynamics framework from the overall Helmholtz free energy, with elastic, plastic and surface damage components. The proposed model is calibrated via traditional damage variables, based on ultrasonic wave velocity measurement and acoustic emission monitoring, and both show great consistency between simulation results and laboratory observations. Then the double-phase field damage model is applied to COMSOL software to simulate microcrack propagation in a pre-fractured rock sample. Both lateral and wing cracks are observed in this study, manifested as shear- and tensile-dominated cracks. We also observed different microcracking mechanisms in the proposed numerical models, such as tensile and shear cracking, the influence of plastic strain and the percolation between tensile and shear microcracks. Overall, this study provides valuable insights into the mechanics of microcracking in rocks, and the proposed model shows promising results in simulating crack propagation. Highlights: Developed an elastoplastic double-phase field damage model with separate tensile and shear phase field damage variables. Calibrated the proposed model using ultrasonic wave velocity measurement and acoustic emission monitoring. Simulated microcrack propagation numerically and observed the occurrence of both tensile and shear cracking in rock materials. Investigated the percolation phenomenon between tensile and shear microcracks, considering the influence of plastic strain. [ABSTRACT FROM AUTHOR]

The current study aims to evaluate the performance of the ultrasonic vibration-assisted milling (USVAM) process when machining two different materials with high deviations in mechanical properties, specifically 7075 aluminium alloy and Ti-6Al-4V titanium alloy. Additionally, this study seeks to develop an AI-based model to predict the process performance based on experimental data for the different workpiece characteristics. In this regard, an ultrasonic vibratory setup was designed to provide vibration oscillations at 28 kHz frequency and 8 µm amplitude in the cutting feed direction for the two characterised materials of 7075 aluminium alloy (150 BHN) and Ti-6Al-4V titanium alloy (350 BHN) workpieces. A series of slotting experiments were conducted using both conventional milling (CM) and USVAM techniques. The axial cutting force and machined slot surface roughness were evaluated for each method. Subsequently, Support Vector Regression (SVR) and artificial neural network (ANN) models were built, tested and compared. AI-based models were developed to analyse the experimental results and predict the process performance for both workpieces. The experiments demonstrated a significant reduction in cutting force by up to 30% and an improvement in surface roughness by approximately four times when using USVAM compared to CM for both materials. Validated by the experimental findings, the ANN model accurately and better predicted the performance metrics with RMSE = 0.11 µm and 0.12 N for Al surface roughness and cutting force. Regarding Ti, surface roughness and cutting force were predicted with RMSE of 0.12 µm and 0.14 N, respectively. The results indicate that USVAM significantly enhances milling performance in terms of a reduced cutting force and improved surface roughness for both 7075 aluminium alloy and Ti-6Al-4V titanium alloy. The ANN model proved to be an effective tool for predicting the outcomes of the USVAM process, offering valuable insights for optimising milling operations across different materials. [ABSTRACT FROM AUTHOR]

The mechanical properties and structure of polybutylene terephthalate (PBT)/aluminum (Al) composite prepared by ultrasonic-assisted hot-pressing were analyzed, and the influence of ultrasonic-assisted on the bonding properties of PBT/Al composite was studied. The experimental results showed that under the optimal ultrasonic-assisted conditions, the tensile shear strength of the PBT/Al composite reached 26.55 MPa, which was 22.18% higher than that of the PBT/Al composite without ultrasonic-assisted (21.73 MPa). Scanning electron microscopy (SEM) showed that during the hot-pressing process, ultrasonic-assisted promoted the embedding of PBT in the anodic oxide pores on the surface of Al, forming a stronger mechanical interlocking structure. X-ray diffraction (XRD) showed that ultrasonic-assisted did not change the crystal type of PBT, but the shear effect of ultrasound affected the arrangement and orientation of molecular chains in the PBT melt, resulting in changes in crystallinity. X-ray photoelectron spectroscopy (XPS) showed that ultrasonic-assisted did not generate new chemical bonds during the hot-pressing process. Therefore, during the hot-pressing process, ultrasonic-assisted promoted the embedding of PBT in the anodic oxide pores on the surface of Al, enhanced the mechanical interlocking effect between PBT and Al, and improved the tensile shear strength of the PBT/Al composite. [ABSTRACT FROM AUTHOR]

Since many years ago, ultrasonic velocity has been used to investigate the physical and mechanical behaviour of rocks, thereby playing an important role in reservoir characterization and seismic interpretation. In order to develop the knowledge of ultrasonic tools, I performed a noble analysis on the ultrasonic behaviour of rocks under confining stress and evaluated a distinctive property of porous media that is measured as the area under the stress–velocity curve (here defined as S*). I further investigated its relationship with elastic and mechanical behaviours of rock. To validate the theoretical framework developed in this work, 20 core plugs from various rock units with complex microstructures were subjected to triaxial compressional tests to calculate their area under the curve. Calculations were made for crack‐closing, elastic and post‐elastic stages (e.g. pore collapse) along the ultrasonic velocity–stress curve. Moreover, the selected samples had their microstructure investigated by thin‐section studies to quantify their porosity and pore type. The results were analysed to check for the effect of pore type on S* in different stages of the stress–velocity curve. Based on the outputs of the analysis of variance and Pearson's correlation coefficient analysis, the curve had its shape and underlying area closely related to the porosity and pore geometry. Indeed, the results showed that the shale and sandstone with micro cracks and carbonate with stiff pores correspond to smaller and larger areas under the curve in crack‐closing and inelastic stages, respectively. Cross‐correlating the results to compressibility (inverse of bulk modulus), it was figured out that the calculated area under curve was well consistent with the compressibility. In addition, S* represents both static and dynamic behaviours of the rock, and the results revealed that the shape and curvature of the stress–velocity curve give valuable information about the rock microstructure. Another finding was the fact that the type of fluid and wave velocity seemingly affect the S*. Our findings can help interpret wave velocity behaviour in reservoir rocks and other stressful porous media. [ABSTRACT FROM AUTHOR]

In an ultrasonic system, a piezoelectric transducer (PT) is a key component and contains a piezo element inside. In order to design and operate a system that uses a piezo element for its intended purpose, resonance analysis of the piezo element and an equivalent circuit analysis of the output stage of the ultrasonic system generator are required. Due to the characteristics of the equivalent circuit, a piezo element has multiple resonance points. Therefore, the system must be operated at the corresponding frequency by tracking the resonance frequency that suits the purpose of the system. In this study, the mechanical resonance frequency of the piezo element was analyzed and a method for operating the system at the corresponding frequency was studied. In order to operate a piezo element, a voltage-type inverter is used to apply a high-frequency AC (Alternating Current). Then, an L C filter is inserted into the output stage of the inverter, and the piezo element is finally located at the output stage of the L C filter. Therefore, when designing an L C filter, a design is required to optimize the performance of the piezo element. In this paper, we analyzed the resonance of a piezo element and the equivalent circuit of the generator output stage of an ultrasonic system for effective operation of an ultrasonic system. In addition, we proposed a method to estimate the characteristics of the entire mechanical resonance frequency range of a piezo element by using an LSTM (Long Short-Term Memory) model suitable for analyzing the nonlinear characteristics of a piezo element. The study on estimating the mechanical resonance frequency of a piezo element using an LSTM model was verified through MATLAB 2021b simulation and ultrasonic system experiments. [ABSTRACT FROM AUTHOR]

Ultrasonic treatment and optimal cultivation techniques are both conducive to the high yield of super rice in South China. Many previous studies have shown that the increase in intercepted photosynthetically active radiation (IPAR) and radiation use efficiency (RUE) is an important reason for high rice yield. Field experiments were conducted over two years to evaluate the effects of IPAR and RUE on the yield under different treatments (CK: conventional cultivation technique without ultrasonic treatment; T1: conventional cultivation technique with ultrasonic treatment; T2: super rice-specific cultivation technique without ultrasonic treatment and T3: super rice-specific cultivation technique with ultrasonic treatment), with two representative rice varieties, Wufengyou-615 (WFY) and Jingnongsimiao (JNSM) during the late seasons of rice cultivation in South China. The super rice-specific cultivation technique and the ultrasonic treatment could significantly increase the yield, which was significantly (p < 0.01) and positively correlated with panicle number, grain-filling rate, and aboveground total dry weight. The higher grain yield depended more highly on higher RUE in the mid-tillering stage and maturity stage. The results of multiple-regression models also showed that the contributions of IPAR and RUE to yield were significant (p < 0.01). Conclusively, IPAR and RUE contributed a lot to yield progress of super rice in both super rice-specific cultivation techniques with fewer times of topdressing and ultrasonic treatment in South China. It is worth further studying how to reasonably improve the RUE of high-RUE varieties through other means. [ABSTRACT FROM AUTHOR]

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

This article presents a review on some important recent research, development, and innovations related to the nonconventional machining of glass material. Nonconventional machining processes were identified suitable for machining of glass, years ago, and from then to now various technological developments have made nonconventional machining a viable alternate to the conventional machining of glass material. In this article, we have mainly focused on three important nonconventional machining processes, namely, last cutting, ultrasonic machining, and electrochemical discharge machining (ECDM). Novel aspects, effects of process parameters, and salient features are discussed. Mainly, previous five years' work is reviewed. This review finally ends with a conclusion and important future research directions. [ABSTRACT FROM AUTHOR]

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

Constant-frequency ultrasonic treatment helped to improve seed germination. However, variable-frequency ultrasonic treatment on maize seed germination were rarely reported. In this study, maize seeds were exposed to 20–40 kHz ultrasonic for 40 s. The germination percentage and radicle length of maize seeds increased by 10.4% and 230.5%. Ultrasonic treatment also significantly increased the acid protease, α-amylase, and β-amylase contents by 96.4%, 73.8%, and 49.1%, respectively. Transcriptome analysis showed that 11,475 differentially expressed genes (DEGs) were found in the ultrasonic treatment and control groups, including 5,695 upregulated and 5,780 downregulated. Metabolic pathways and transcription factors (TFs) were significantly enriched among DEGs after ultrasonic treatment. This included metabolism and genetic information processing, that is, ribosome, proteasome, and pyruvate metabolism, sesquiterpenoid, triterpenoid, and phenylpropanoid biosynthesis, and oxidative phosphorylation, as well as transcription factors in the NAC, MYB, bHLH, WRKY, AP2, bZIP, and ARF families. Variable-frequency ultrasonic treatment increased auxin, gibberellin, and salicylic acid by 5.5%, 37.3%, and 28.9%, respectively. Abscisic acid significantly decreased by 33.2%. The related DEGs were upregulated and downregulated to varying degrees. Seed germination under the abiotic stress conditions of salt stress (NaCl solution), drought (PEG solution), and waterlogging (water-saturated sand bed) under ultrasonic treatment were promoted, radicle length was significantly increased by 30.2%, 30.5%, and 27.3%, respectively; and germination percentage by 14.8%, 20.1%, and 21.6%, respectively. These findings provide new insight into the mechanisms through ultrasonic to promote maize seed germination. [ABSTRACT FROM AUTHOR]

Non-destructive characterization of cementitious materials is essential to ensure structural integrity and longevity in civil engineering. This study presents an advanced approach using singular value decomposition (SVD) to analyze ultrasonic dispersion curves, thereby improving the clarity and precision of ultrasonic characterization of cement slabs. We focused on the impact of different water/cement ratios on ultrasonic properties, revealing how these ratios influence the material's microstructure and mechanical properties. Our results show that higher water/cement ratios increase porosity and reduce density, thus slowing down the propagation of ultrasonic waves and potentially reducing mechanical strength. The application of SVD allowed for the isolation of significant signal components, providing a better understanding of the acoustic behavior and mechanical properties of the material. These findings highlight the importance of precise control over the water/cement ratio in the development of durable and robust cementitious structures. The study suggests that SVD can significantly improve the reliability of non-destructive testing methods, making it a valuable tool in materials science and engineering. This research advances current methodologies by offering enhanced accuracy in characterizing the internal structure and mechanical properties of cementitious materials. [ABSTRACT FROM AUTHOR]

Summary: The effects of hydrostatic thawing (HT), flowing water thawing (FT), ultrasonic thawing (UT), microwave thawing (MT), and microwave‐combined ultrasonic thawing (MUT) on the quality of yellowtail fillets were investigated via thawing time, physicochemical quality, water retention, microstructure and water migration distribution. The results showed that MUT had a shorter thawing time, second only to microwave thawing (MT) and significantly shorter than other thawing methods. Moreover, MUT could retain a better performance of the samples, such as colour, texture, water retention and moisture distribution, and prevent damage to the microstructure. In addition, freshness analysis showed that pH, total volatile saline nitrogen and K values were optimal for MUT. Therefore, MUT could be a viable thawing method that increases the thawing rate of yellowtail fillets while maintaining their quality characteristics. [ABSTRACT FROM AUTHOR]

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

In ultrasonic nondestructive testing (NDT), accurately estimating the time of flight (TOF) of ultrasonic waves is crucial. Traditionally, TOF estimation involves the signal processing of a single measured waveform. In recent years, deep learning has also been applied to estimate the TOF; however, these methods typically process only single waveforms. In contrast, this study acquired fan-beam ultrasonic waveform profile data from 64 paths using an ultrasonic-speed computed tomography (CT) simulation of a circular column and developed a TOF estimation model using two-dimensional convolutional neural networks (CNNs) based on these data. We compared the accuracy of the TOF estimation between the proposed method and two traditional signal processing methods. Additionally, we reconstructed ultrasonic-speed CT images using the estimated TOF and evaluated the generated CT images. The results showed that the proposed method could estimate the longitudinal TOF more accurately than traditional methods, and the evaluation scores for the reconstructed images were high. [ABSTRACT FROM AUTHOR]

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

Hexagonal boron nitride (h‐BN) is widely used as a filler to improve the thermal conductivity of polymers due to the high thermal conductivity, electrical insulation, and chemical stability. However, the small lateral‐size and poor compatibility limit h‐BN's performances and applications in thermal management. Here, boron nitride nanosheets (BNNSs) were prepared by liquid‐phase ultrasonic exfoliation using isopropanol (IPA) as solvent. Specifically, the BNNSs obtained by ultrasonication for 8 h with an initial concentration of h‐BN of 8 mg/mL have the best exfoliation effect and a high yield of 19.8%, showing a large lateral‐size of 1–2 μm and an ultra‐thin thickness. Then, the resulting BNNSs can be modified by grafting silane coupling agent of KH560 (m‐BNNSs), their micromorphology and chemical composition are characterized by various microscopies and spectrometers. Subsequently, polyacrylate pressure‐sensitive adhesives (PSAs) composites are prepared using m‐BNNSs as a thermally conductive filler by UV bulk polymerization, their thermal conductivity can be greatly improved by 250% compared with that of pure PSAs. For comparison, the thermal conductivity of m‐BNNSs/PSAs composites with filler content of 25 wt% is as high as 0.4382 W/(m K), which is 1.6 times higher than that of h‐BN/PSAs composites. In addition, the incorporation of BNNSs will improve the thermal stability, hardness, and 180° peeling force of the PSAs composites, which will stimulate the practical application of PSAs materials. [ABSTRACT FROM AUTHOR]

Ni-TiN composite coating is widely used as a protective coating due to its good mechanical properties and corrosion resistance. In this study, Ni-TiN nanocomposite coatings were prepared by ultrasonic-assisted jet electrodeposition. The growth mechanism and properties of the composite coatings in ultrasonic-assisted jet electrodeposition were studied. It was found that the surface morphology of the composite coating changed significantly with the increase in the concentration of nano TiN particles. Ultrasonic affects the selective orientation of the coating, and both lead to grain refinement. The addition of ultrasonic promotes the growth of (111) crystalline surfaces of the coating. Ultrasonic-assisted jet electrodeposition reduced tip discharge and nanoparticle agglomeration, and the surface quality, physical and chemical properties of the nanocomposite coating were significantly improved. The microhardness of the Ni-TiN composite coating was as high as 622.4 HV, the maximum adhesion was 27.2 N, and the corrosion resistance was the best with the corrosion current density at 1.898 μA cm−2, when the amount of nano TiN was 10 g/L. This method will provide a reference for improving the growth uniformity of jet electrodeposition. [ABSTRACT FROM AUTHOR]

BACKGROUND RESULTS CONCLUSION The preparation of malic acid starch ester (MSE) is mostly carried out using a high temperature method, but there are problems such as high energy consumption, long preparation time, and uneven heating. Microwave technology can be used to overcome these limitations. The semi‐crystalline structure of starch granules hinders the modifier's access to the matrix, thus limiting the esterification reaction. Physical techniques can act on the interior of the starch to create a number of active sites, thereby facilitating the reaction of the starch with esterification reagents. Therefore, this study investigated the effect of starch pretreatment by microwave, heat‐moisture, and ultrasonic techniques on the degree of substitution (DS), structure, and physicochemical properties of MSE synthesized by the microwave method.The DS of MSE was increased after pretreatments. The modified starch obtained by different pretreatment methods did not show new characteristic peaks, while the MSE synthesized showed new absorption peaks near 1735 cm−1. The granular structure and morphology of the modified starch obtained by microwave and heat‐moisture pretreatment were gelatinized and aggregated, while some of the starch particles of the modified starch obtained by ultrasonic pretreatment appeared pore‐sized. The relative crystallinity and gelatinization enthalpy of the MSE were reduced, but the crystallization pattern remained as A‐type.Overall, the results suggest that various pretreatment methods can enhance the DS of MSE by disrupting the structure of starch. The findings of this study provide theoretical support for improving the DS of esterified starch. © 2024 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

This study explores the extraction of rare earth elements (REEs) from high-ash run-of-mine and discard coal sourced from the Waterberg Coalfield. Three distinct methods were employed: (1) ultrasonic-assisted caustic digestion; (2) direct acid leaching; and (3) ultrasonic-assisted caustic-acid leaching. Inductively coupled plasma mass spectrometry was utilized to quantify REEs in both the coals and resultant leachates. Leaching the coals with 40% NaOH at 80 °C, along with 40 kHz sonication, yielded a total rare earth element (TREE) recovery of less than 2%. Notable enrichment of REEs was observed in the run-of-mine and discard coal by 17% and 19%, respectively. Upon employing 7.5% HCl, a recovery of less than 11.0% for TREE was achieved in both coal samples. However, leaching the caustic digested coal samples with 7.5% HCl significantly enhanced the TREE recovery to 88.8% and 80.0% for run-of-mine and discard coal, respectively. X-ray diffraction analysis identified kaolinite and quartz as the predominant minerals. Scanning electron microscopy-energy dispersive microanalysis revealed monazite and xenotime as the REE-bearing minerals within the coal samples. These minerals were found either liberated, attached to, or encapsulated by the clay-quartz matrices. Further mineralogical assessments highlighted the increased REE concentrations in coals post-caustic digestion and subsequent recovery during acid leaching. This increase was attributed to the partial dissolution of kaolinite encapsulating the RE-phosphates and the digestion of REE-bearing minerals. Notably, undissolved REE-bearing elements in the caustic-acid-leached coal indicated the necessity of harsh leaching conditions to augment REE recovery from these coal samples. [ABSTRACT FROM AUTHOR]

Ultrasonic technology, which has been receiving increasing attention from the petroleum industry, has emerged as a promising environmentally-friendly technology due to its high adaptability, simple operation, low cost, and lack of pollution; the mechanisms of this technology are clarified herein. At the same time, this paper presents a comprehensive review of the impact of ultrasound on enhanced oil recovery (EOR) by removing plugs, reducing oil viscosity, and demulsifying crude oil, while highlighting the latest advancements in this field. Lastly, this paper delves into the challenges and prospects associated with the industrial implementation of power ultrasound. The objective of this review is to provide a comprehensive overview of recent advancements, serving as a valuable reference for future investigations on ultrasound-assisted EOR. Oil field results demonstrate that oil production increased by 26.5% to 100%, water cut decreased by 5% to 96%, the success rate ranged from 75% to 90%, and the effect can last for a duration of 4 h to 12 months. [ABSTRACT FROM AUTHOR]

Large amounts of agri-food waste are generated and discarded annually, but they have the potential to become highly profitable sources of value-added compounds. Many of these are lignin-rich residues. Lignin, one of the most abundant biopolymers in nature, offers numerous possibilities as a raw material or renewable resource for the production of chemical products. This study aims to explore the potential revalorization of agricultural by-products through the extraction of lignin and subsequent depolymerization. Different residues were studied; river cane, rice husks, broccoli stems, wheat straw, and olive stone are investigated (all local wastes that are typically incinerated). Traditional soda extraction, enhanced by ultrasound, is applied, comparing two different sonication methods. The extraction yields from different residues were as follows: river cane (28.21%), rice husks (24.27%), broccoli (6.48%), wheat straw (17.66%), and olive stones (24.29%). Once lignin is extracted, depolymerization is performed by three different methods: high-pressure reactor, ultrasound-assisted solvent depolymerization, and microwave solvolysis. As a result, a new microwave depolymerization method has been developed and patented, using for the first time graphene nanoplatelets (GNPs) as new promising carbonaceous catalyst, achieving a 90.89% depolymerization rate of river cane lignin and yielding several building blocks, including guaiacol, vanillin, ferulic acid, or acetovanillone. [ABSTRACT FROM AUTHOR]

This study presents a systematic review with meta-analysis to evaluate the success rates of endodontic retreatments in teeth where separated instruments are located within the roots. The search and selection of studies were conducted across two databases, SCOPUS and PubMed, as well as the Cochrane Library registry, yielding a total of 1620 records. Following the selection process, 11 studies were included in the systematic review. Overall, out of 1133 retreated teeth, there were 172 failures in instrument removal and 55 perforations. The meta-analysis results indicate that failures are more frequent when instruments are located in the apical third, with a failure rate of 21%, compared to an 8.8% failure rate in the middle/coronal third. The anatomy of the root canals, particularly the location of the separated instruments, significantly influences the success rates. [ABSTRACT FROM AUTHOR]

Aim: The aim of this study was to evaluate the removal efficiency of PRMTA and ECMPremixed applied to the coronal third according to the RET by UI and to examine the effect of different solutions on material removal. Materials and methods: 40 permanent upper central teeth were used to simulate immature teeth. The samples were irrigated with 1.5% NaOCl and calcium hydroxide was placed. Samples were incubated in PBS. Then irrigation was done with 17% EDTA, the samples were randomly divided into 2 groups (n = 20):Group 1: PRMTA, Group 2: ECM Premixed. The materials were placed in the samples. Then the samples were scanned with micro-CT. Materials were removed by UI. Micro-CT scan of the samples was performed. Each material group was divided into 2 subgroups (n = 10): Group1 was MTAD, group2 was irrigated with 10% CA; then micro-CT was performed. Obtained images were positioned in DataViewer and analyzed with CTAn. The obtained data were statistically analyzed in IBM SPSS 25. The significance level was determined as 5%. Results: There was no significant difference between the initial volumes of the materials (p > 0.05). The amount of the remaining material after UI was significantly higher in the PRMTA (0.7471%) group compared to the ECM Premixed (0.0093%). There was no significant difference in terms of remaining material after irrigation with MTAD and CA in both groups (p > 0.05). Conclusion: A great deal of the materials were removed by UI under the operation microscope. ECM Premixed was removed more effectively compared to the PRMTA. And, acidic solutions did not provide any additional benefit in material removal. [ABSTRACT FROM AUTHOR]

Diagnostic ultrasound visualization was initially developed and introduced as a more benign alternative to X-rays and is today established as a harmless routine procedure and tool for risk management, but as this article shows, it took several decades to overcome the popular notion that ultrasound itself was a high-risk technology, a potentially deadly weapon. Swedish newspaper material provides a window into internationally circulated narratives portraying ultrasound as both a frightening and promising phenomenon. These ideas also constituted an important context for risk assessment during the early adoption and development of obstetrical ultrasound imaging, as shown by the case of Lund, Sweden, where the still-experimental technology was first imported from Scotland in the early 1960s. The article repositions ultrasound in the history of risk and risk management in modern societies and also sheds new light on the history of ultrasound visualization by situating it in a broader context of media culture. [ABSTRACT FROM AUTHOR]

Ultrasonic wave propagates with strong penetration, high stability, and has non-contact nature, therefore it is widely used in the petroleum industry. As an application example, an ultrasonic flowmeter can accurately measure the annular flow rate of water-based drilling fluid. According to the outlet flow rate, it can be noticed if there is an abnormal situation in the well to avoid accidents such as well kick and blowout. However, due to the attenuation of ultrasonic wave in the drilling fluid, the relevant research results are not reliable. Herein, based on the theory of acoustics, the influences of water-based drilling fluid density, solid particle size and solid particle number on the ultrasonic attenuation characteristics under different frequencies are studied by numerical simulation. First, the propagation characteristics of ultrasonic wave in water-based drilling fluid are systematically analyzed, then the accuracy of the above results is verified by laboratory tests. The results show that the ultrasonic attenuation rate is positively correlated with the solid particle size, solid particle number and ultrasonic frequency in water-based drilling fluid, while it is negatively correlated with the density of water-based drilling fluid. Furthermore, it is established that the ultrasonic energy decreases with increasing propagation distance. The results of this study can provide a theoretical basis and practical guidance for using an ultrasonic flowmeter to accurately measure the annulus return flow rate of drilling fluid and develop an intelligent drilling system, so as to improve the efficiency of field operation and drilling success rate. [ABSTRACT FROM AUTHOR]

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The highly crystalline mesoporous series of various percentages such as 1, 3 and 5% of CeO2-doped MoO3 nanocomposite were synthesized successfully by using ultrasonic wave-assisted sol–gel synthesis procedure and calcined at 873 K for 3 h. The synthesized CeO2-MoO3 nanocomposite material characterized by different techniques like XRD, Raman, FT-IR, FE-SEM, HR-TEM, BET, XPS and UV-DRS measurements to find crystallinity, surface morphology, surface area, structural and optical properties. Among these, 5% CeO2-MoO3 nanocomposite shows excellent photo-Fenton dye degradation activity of Rhodamine-B (Rh-B) dye in visible light irradiation using direct sunlight. Maximum degradation was observed (95.36% in 120 min) with optimum condition of pH, catalyst amount and H2O2 concentration. These nanocomposite material was recovered, recycle and its reusability also gives excellent results up to the 4th cycle. Similarly, turn over number, turn over frequency, kinetic study and scavenger study of photo-Fenton degradation reaction were also discussed. [ABSTRACT FROM AUTHOR]

Cryogenic and ultrasonic-assisted turning have both beneficial effects on the machinability of difficult-to-machine materials, such as titanium alloy Ti-6Al-4V. This research investigates the effect of combining both cryogenic and ultrasonic-assisted machining, to assess the effects on cutting temperature, forces and tool wear. The research utilizes FEM and CFD models to provide a better understanding of the interaction between the mechanisms at work during the machining process—namely the ultrasonic motion of the tool and the cryogenic impingement of the tool. The experimentation is then conducted to prove the effectiveness of combining both methods in reducing the cutting forces and reducing tool wear. The combined process is compared to conventional turning, cryogenic turning and ultrasonic-assisted turning. The CFD and FEM results showed a decrease in tool and chip temperature by 7.26% and 13.86%, respectively, when compared to UAT. The cutting forces in the combined turning show a reduction of 22% when compared to conventional turning. Tool wear is analyzed for the 4 cases. Tool wear caused by adhesion is shown to decrease in the new combined cutting method. This research has scientific as well as potential industrial applications in the machining of difficult-to-machine materials. [ABSTRACT FROM AUTHOR]

Al-Si alloy as a matrix in Aluminium Metal Matrix Composites (AMCs) augments the hardness and strength. The work reports the characterization and mechanical properties of Hybrid Aluminium Metal Matrix Nanocomposites (HAMNCs) using Hypereutectic Al-Si grade LM30 alloy as the matrix with boron Carbide (nB4C) and Rutile (nTiO2) nanoparticles as reinforcements. Liquid metallurgy route ultrasonic squeeze-assisted stir-casting was employed to manufacture hybrid formulations. The HAMNC specimens were fabricated by maintaining 1 wt.% of nB4C and by varying TiO2 nanoparticles in steps of 0.25 wt.% in the 0 to 1 wt.% range. The optical micrographs revealed that ultrasonic vibration and squeeze casting effects aided the uniform distribution of nano reinforcements and lowered the porosity. XRD analysis revealed the formation of Aluminum Titanium Silicate (Al4Ti2SiO12) due to the addition of nTiO2. The results highlighted that the LM30 matrix having 1.0 wt.% of nB4C and 0.75 wt.% of nTiO2 exhibited the maximum hardness of 107.2 HRB, ultimate tensile strength of 265.52 MPa, and compressive strength of 656 MPa. The tensile fractography using FESEM highlighted the various kinds of dendrites associated with the fracture. nB4C and TiO2 nano reinforcements increased energy absorption during impact failure. [ABSTRACT FROM AUTHOR]

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

In order to improve the functional properties of porcine heart protein and improve its application feasibility in the food industry, this study modified porcine heart protein (PHP) by ultrasonic (frequency of 20 kHz, power of 350 W, treatment for 8 min, working 5 s with 2 s intervals) combined with different concentrations of ethanol (0~80%). The changes of molecular structure, microstructure, active sulfhydryl content, surface hydrophobicity, solubility, emulsification, emulsion particle size and emulsion Zeta potential of modified PHP were determined. The results showed that the primary structure, secondary structure and microstructure of PHP were significantly changed under the combined action of ultrasonic and 40% ethanol modification. The ultraviolet absorption intensity of PHP was the largest, the active sulfhydryl content and surface hydrophobicity were the largest. The solubility of protein was significantly reduced (P

This study comparatively analyzed the effects of water bath (WB) and ultrasonic-assisted water bath (UWB) extraction at different pH conditions on the extraction kinetics, gelling properties, rheological properties, and structural properties of grass carp fish scale gelatin. Results indicated that the gel strength of fish scale gelatin extracted by UWB was greater than that obtained by WB at pH more than 7.0. The rheological results demonstrated that UWB elevated the apparent viscosity of fish scale gelatin, but decreased the gelling and melt points. The results of structural analysis indicated that UWB resulted in a reduction in the content of α-helix and β-sheet in fish scale gelatin. Furthermore, both pH and UWB were found to alter the tertiary structure of fish scale gelatin. This study may provide novel ideas for the high-value comprehensive utilization of fish scale waste.

Abstract Constant-frequency ultrasonic treatment helped to improve seed germination. However, variable-frequency ultrasonic treatment on maize seed germination were rarely reported. In this study, maize seeds were exposed to 20–40 kHz ultrasonic for 40 s. The germination percentage and radicle length of maize seeds increased by 10.4% and 230.5%. Ultrasonic treatment also significantly increased the acid protease, α-amylase, and β-amylase contents by 96.4%, 73.8%, and 49.1%, respectively. Transcriptome analysis showed that 11,475 differentially expressed genes (DEGs) were found in the ultrasonic treatment and control groups, including 5,695 upregulated and 5,780 downregulated. Metabolic pathways and transcription factors (TFs) were significantly enriched among DEGs after ultrasonic treatment. This included metabolism and genetic information processing, that is, ribosome, proteasome, and pyruvate metabolism, sesquiterpenoid, triterpenoid, and phenylpropanoid biosynthesis, and oxidative phosphorylation, as well as transcription factors in the NAC, MYB, bHLH, WRKY, AP2, bZIP, and ARF families. Variable-frequency ultrasonic treatment increased auxin, gibberellin, and salicylic acid by 5.5%, 37.3%, and 28.9%, respectively. Abscisic acid significantly decreased by 33.2%. The related DEGs were upregulated and downregulated to varying degrees. Seed germination under the abiotic stress conditions of salt stress (NaCl solution), drought (PEG solution), and waterlogging (water-saturated sand bed) under ultrasonic treatment were promoted, radicle length was significantly increased by 30.2%, 30.5%, and 27.3%, respectively; and germination percentage by 14.8%, 20.1%, and 21.6%, respectively. These findings provide new insight into the mechanisms through ultrasonic to promote maize seed germination.

BACKGROUND AND OBJECTIVES: Calophyllum inophyllum (C. inophyllum), or Nyamplung, seeds contain various active compounds. Using C. inophyllum seeds as a source of flavonoids for natural antioxidants can increase their economic value and provide alternative compounds for cosmetics, including lotions. This study applied maceration and ultrasonic methods using ethanol to extract the active compounds from the C. inophyllum seeds. The study optimised extracting the antioxidant components from C. inophyllum seeds using response surface methodology.METHODS: The experimental design used in this study was response surface methodology with a Box–Behnken design to model the influence of variables on the response of the yield and antioxidant activity of extracts obtained through maceration and ultrasonic extraction and to model lotion formulation. The extraction methods were designed with three variables (extraction time, solvent concentration, and sample–solvent ratio) and three levels (low, medium, and high), and the compounds in the extracts were analysed. Lotion formulation was designed with three variables (C. inophyllum seed extract, Tween 80, and carbomer) and three levels (low, medium, and high), and the quality of the lotion product (antioxidant activity and viscosity) was analysed.Results: The C. inophyllum seed extract obtained through maceration had stronger antioxidant activity than that obtained using the ultrasonic method, with 50 per cent inhibition concentration values of 13.154 and 16.343 part per million, respectively. Characterisation with gas chromatography-mass spectroscopy revealed ten compounds with major percentage values, among them 2''-(trimethylsilyl)oxy-3,4,4'',5- tetramethoxychalcone (49.70 per cent). This compound played an important role in enhancing antioxidant activity in C. inophyllum seeds extracted through maceration, whereas butylated hydroxytoluene (9.16 per cent) was important in the extract obtained using the ultrasonic method. The lotion produced from the C. inophyllum seed extract contained high antioxidant activity with a 50 per cent inhibition concentration of 4.621 part per million; the toxicity text showed it was safe to be used (50 per cent lethal concentration of 789 grams per millilitre).CONCLUSION: The results showed the effectiveness of this approach in determining the optimal conditions to maximise antioxidant content. The maceration method better ability enhanced the antioxidant activity capacity of C. inophyllum seeds compared to the ultrasonic method, as indicated by the response surface method. Both extraction methods produced the same secondary metabolite compounds with a promising reservoir of antioxidant compounds. In addition, the findings of this study showed the high antioxidant activity of C. inophyllum seed extract lotion, which could be developed for pharmaceutical, nutraceutical, and other applications.

Abstract This study explores the extraction of rare earth elements (REEs) from high-ash run-of-mine and discard coal sourced from the Waterberg Coalfield. Three distinct methods were employed: (1) ultrasonic-assisted caustic digestion; (2) direct acid leaching; and (3) ultrasonic-assisted caustic-acid leaching. Inductively coupled plasma mass spectrometry was utilized to quantify REEs in both the coals and resultant leachates. Leaching the coals with 40% NaOH at 80 °C, along with 40 kHz sonication, yielded a total rare earth element (TREE) recovery of less than 2%. Notable enrichment of REEs was observed in the run-of-mine and discard coal by 17% and 19%, respectively. Upon employing 7.5% HCl, a recovery of less than 11.0% for TREE was achieved in both coal samples. However, leaching the caustic digested coal samples with 7.5% HCl significantly enhanced the TREE recovery to 88.8% and 80.0% for run-of-mine and discard coal, respectively. X-ray diffraction analysis identified kaolinite and quartz as the predominant minerals. Scanning electron microscopy-energy dispersive microanalysis revealed monazite and xenotime as the REE-bearing minerals within the coal samples. These minerals were found either liberated, attached to, or encapsulated by the clay-quartz matrices. Further mineralogical assessments highlighted the increased REE concentrations in coals post-caustic digestion and subsequent recovery during acid leaching. This increase was attributed to the partial dissolution of kaolinite encapsulating the RE-phosphates and the digestion of REE-bearing minerals. Notably, undissolved REE-bearing elements in the caustic-acid-leached coal indicated the necessity of harsh leaching conditions to augment REE recovery from these coal samples.

Abstract Aim The aim of this study was to evaluate the removal efficiency of PRMTA and ECMPremixed applied to the coronal third according to the RET by UI and to examine the effect of different solutions on material removal. Materials and methods 40 permanent upper central teeth were used to simulate immature teeth. The samples were irrigated with 1.5% NaOCl and calcium hydroxide was placed. Samples were incubated in PBS. Then irrigation was done with 17% EDTA, the samples were randomly divided into 2 groups (n = 20):Group 1: PRMTA, Group 2: ECM Premixed. The materials were placed in the samples. Then the samples were scanned with micro-CT. Materials were removed by UI. Micro-CT scan of the samples was performed. Each material group was divided into 2 subgroups (n = 10): Group1 was MTAD, group2 was irrigated with 10% CA; then micro-CT was performed. Obtained images were positioned in DataViewer and analyzed with CTAn. The obtained data were statistically analyzed in IBM SPSS 25. The significance level was determined as 5%. Results There was no significant difference between the initial volumes of the materials (p > 0.05). The amount of the remaining material after UI was significantly higher in the PRMTA (0.7471%) group compared to the ECM Premixed (0.0093%). There was no significant difference in terms of remaining material after irrigation with MTAD and CA in both groups (p > 0.05). Conclusion A great deal of the materials were removed by UI under the operation microscope. ECM Premixed was removed more effectively compared to the PRMTA. And, acidic solutions did not provide any additional benefit in material removal.