Application Of Ultrasonic Energy Research Articles

Ultrasonic-assisted alkali hydrolysis of polyethylene terephthalate fabric and its effect on the microstructure and dyeing properties of fibers

Abstract In this study, ultrasound energy was applied to assist the alkali hydrolysis of polyethylene terephthalate (PET) fabric, and then, the results were compared with those of the mechanical oscillating method, which was used as the control. The effects of various factors such as the sodium hydroxide concentration, the dosage of dodecyl dimethyl benzyl ammonium chloride (DDBAC), and the frequency on the weight loss of the PET fabrics were systematically investigated. The surface appearance and microstructures of the treated fibers with different methods were analyzed using a scanning electron microscope and X-ray diffraction, respectively. The results showed that DDBAC played a prominent accelerating role in the hydrolysis of the PET polymer, and the frequency had a great influence on the weight loss of the PET fabric. Ultrasound with a frequency of 60 kHz showed a similar decomposition rate as the control, resulting in similar weight loss, which was the highest value among the three frequencies (20, 60, and 80 kHz). In addition, the application of ultrasonic energy led to more pits on the fiber surface, a smaller average grain size, and decreased crystallinity of the treated fibers, while the mechanical oscillating method resulted in slightly increased crystallinity. By comparing the K/S value of the dyed fabrics with two commercial disperse dyes, we found that the treatment method had no obvious correlation with the color depth of the treated fabric.

Effectiveness of ultrasonic energy in introitoplasty

Introduction. Currently, the application of ultrasonic energy for tissue dissection is a routine practice in surgery. Its effectiveness and safety has been proven in proctology, pediatric coloproctology, surgeries in the endocrine organs and in the abdominal organs.Material and methods. Given the features of the endocrine system, the anatomy of virilized genitalia and positive experience in applying ultrasonic energy for surgical interventions, the authors present a comparative trial on the effectiveness of ultrasonic knife (USK) and traditional electrocoagulation in vaginoplasty in patients with disorders of sex development.Results. The obtained findings demonstrate that USK in comparison to traditional electrocoagulation significantly reduces vaginoplasty duration by 30%: median and quartiles of this index with USK were 57.5 [50; 65] min, while in the electrocoagulation group – 82.5 [75; 90] min. Difference is statistically significant (U-test 83.5, p 0.001) too. Difference between medians and its 95% confidence interval was 25 [20; 35] min.Conclusion. USK has better effects due to less tissue bleeding and, as a consequence, better visualization of the surgical field. An additional advantage is a unique ability to gently mobilize and preserve anatomical structures of the pelvis.

Evaluation of enhancement techniques for the dechlorination of DDT by nanoscale zero-valent iron

Due to its low toxicity and high reactivity, nanoscale zero-valent iron (nZVI) is widely used as a remediation agent. However, nZVI is also prone to rapid aggregation and surface oxidation, which significantly reduces its practical efficacy. Here three enhancement techniques, proposed to overcome these limiting factors, incremental addition, pH adjustment and the application of ultrasonic energy, were systematically evaluated for their ability to increase the remediation efficiency of 1,1,1-Trichloro-2,2-bis(4-chlorophenyl)ethane (DDT) sorbed onto the surface of a soil surrogate. The efficacy of nZVI was also compared to the effectiveness of microscale zero valent iron (μZVI). Of the three enhancement techniques studied, only ultrasonic energy significantly enhanced the effectiveness of nZVI for the degradation of DDT and its primary degradation products due to disaggregation and surface cleaning of nZVI and increased ultrasound induced mixing. While pH had no effect on the degradation efficiency of nZVI, low pH significantly enhanced the effectiveness of μZVI remediation. This was attributed to the sustained low solution pH reducing surface corrosion products, increasing surface area and maintaining a cationic surface for attracting anionic DDT.

Ultrasonic micromoulding: Process characterisation using extensive in-line monitoring for micro-scaled products

Industry-standard quality management systems such as Six Sigma and emerging Industry 4.0 compliant production processes demonstrate the importance of in-line condition monitoring of manufacturing methods for achieving the highest levels of product quality. Measurement data collected as the process is running can inform the operator about unexpected changes in machine operation or raw materials that could negatively impact production; and offer an opportunity for a process control intervention to stabilise production. However, micro-manufacturing production lines can pose a challenging environment for deploying such systems, since processing events can occur extremely rapidly and in harsh environments. Moreover, the small scale of micro-nano featured components can make sensor installation even more problematic. Recently, ultrasonic micromoulding has drawn attention in niche markets due to its unique advantages for processing thermoplastics as a new micro-manufacturing technology. The process differs from conventional moulding significantly by eliminating the need for a plasticising screw and using direct application of ultrasonic energy to melt the polymer. This offers numerous benefits such as decrease in energy usage, moulding at lower pressures, easier cleaning, and reduced material residence times, the latter which could be beneficial for pharma-grade polymers or polymers with active ingredients. However, very little work has been reported attempting to monitor the process using in-line measurements. This work aims to evaluate the characteristics of the ultrasonic micromoulding process for microinjection moulding of a microneedle array using a range of sensor technologies including: data recorded by the machine controller; a high-speed thermal camera and a cavity pressure transducer. The data has captured the highly dynamic process environment with a high degree of accuracy. The relationship between the process data and dimensional quality of the ultrasonically micromoulded products has been quantified and subsequently implemented as a cost-effective in-line quality assurance method.

Effects of Ultrasonic Bending Vibration Introduced by an L-Shaped Ultrasonic Rod on the Microstructure and Properties of a 1060 Aluminum Alloy Strip Formed by Twin-Roll Casting.

In order to achieve the industrial application of ultrasonic energy in the continuous casting and rolling production of aluminum alloy, a new type of L-shaped ultrasonic rod was used to introduce an ultrasonic bending vibration into the aluminum melt in the launder during the horizontal twin-roll continuous casting and rolling process of a 1060 aluminum alloy. The effects of the ultrasonic bending vibration on the microstructure and properties of the 1060 aluminum alloy cast rolling strip and its subsequent cold rolling strip were studied experimentally, and the effect of the ultrasonic-assisted refining with different amounts of Al-Ti-B refiner was explored. The results show that under the same addition amount of Al-Ti-B refiner, the ultrasonic bending vibration can refine the grains of the cast rolling strip, make the distribution of precipitates more uniform, reduce the slag inclusion defects, and improve the mechanical properties to a certain extent. The microstructure and properties of the ultrasonic cast rolling strip with 0.18 wt% Al-Ti-B refiner or 0.12 wt% Al-Ti-B refiner are better than those of the conventional cast rolling strip, but the microstructure and properties of the ultrasonic cast rolling strip with 0.09 wt% Al-Ti-B refiner are slightly worse than those of the conventional cast rolling strip. Moreover, after cold rolling, the effect of the ultrasonic bending vibration on the improvement of the microstructure and properties of the aluminum alloy strip is inherited. A comprehensive analysis shows that the use of ultrasonic energy in this paper cannot completely replace the effect of the Al-Ti-B refiner, but it can reduce the addition amount of the Al-Ti-B refiner by 1/3.

Microstructure evolution of Al6061 and copper during ultrasonic energy assisted compression

Metal forming is often performed at elevated temperatures, typically above the recrystallization temperature of metals, which results in a reduction in yield stress during forming. Similar reduction in yield stress can also be achieved by simultaneous application of ultrasonic energy during deformation. The resulting softening of metals causes a reduction in the forming forces and increased ductility. A thorough understanding of the effect of ultrasonic energy irradiation during deformation on the microstructure is lacking which seems to be inhibiting wider adoption of ultrasonic energy in more manufacturing processes. In this manuscript, a detailed analysis of the microstructure of aluminum 6061 alloy and copper, which have identical Faced-Center Cubic crystal structure but different stacking fault energies, has been presented. Focus has been placed on the differences between their microstructure evolution behaviors after deformation under simultaneous application of ultrasonic energy. These differences have been distinctly highlighted using Electron Backscatter Diffraction (EBSD) and TEM analysis. EBSD analysis revealed assistance to subgrain formation due to ultrasonic energy. It was also observed that due to lack of dynamic recovery, copper underwent discontinuous dynamic recrystallization (DDRX) during ultrasonic energy assisted deformation. On the other hand, the recrystallization mechanism in Al6061 alloy was found to be geometric dynamic recrystallization (gDRX). The insights obtained in this work potentially advance the understanding of mechanisms governing microstructure evolution during ultrasonic energy assisted deformation and establish analogy between the mechanisms governing thermomechanical processing and ultrasonic energy assisted deformation.

Control of cystic artery during laparoscopic cholecystectomy: clips versus ultrasonic energy devices which is better?

Background: This study was undertaken to know whether clip usage or ultrasonic energy application, obtains better haemostasis of cystic artery during laparoscopic cholecystectomy.Methods: About 80 patients undergoing laparoscopic cholecystectomy were selected on a prospective basis and divided into two equal groups- A and B. a comparative study was done between the two group. Clips were used to control cystic artery in group A patients and ultrasonic energy device was used for the same in group B.Results: In group A, 2 patients had clip slippage intraoperatively which was dealt by reapplication of clips.in group B,1 patient had intraoperative bleeding from cystic artery few minutes after application of ultrasonic energy which was dealt by bipolar cauterization. In both the groups no, postoperative bleeding was encountered.Conclusions: During laparoscopic cholecystectomy, clip usage and ultrasonic energy application are equally competent in achieving haemostasis of cystic artery.

Fresh and mechanical properties, and strain sensing of nanomodified cement mortars: The effects of MWCNT aspect ratio, density and functionalization

A comprehensive analysis on the effect of aspect ratio, bulk density and functionalization of multi walled carbon nanotubes (MWCNTs) in the development of nanomodified mortars, reinforced with different types of MWCNTs is presented herein. A structural characterization of the pristine and functionalized carbon nanotubes was carried out with scanning electron microscopy (SEM), transmission electron microscopy (TEM), and thermogravimetric analysis (TGA). A simple one step dispersion method, involving the application of ultrasonic energy and the use of a superplasticizer (SP) was utilized for the preparation of uniformly dispersed MWCNT suspensions. The experimental determination of the fresh and 28d mechanical properties of mortars with w/c = 0.5 and s/c = 3.0, using four different types of well dispersed pristine and functionalized MWCNTs at an amount of 0.1 wt% of cement took place through: (i) flow and time of setting tests; (ii) three point bending experiments on 4 × 4 × 16 cm specimens; and (iii) uniaxial compression on the half prisms of the flexural test specimens (4 × 4 × 8 cm). The piezoresistive behavior of the mortars reinforced with the pristine MWCNTs was experimentally determined using the 4-pole method, and compared with the strain sensing ability of the mortars reinforced with the functionalized MWCNTs. All MWCNT reinforced mortars exhibit a remarkable enhancement in the mechanical properties. However, the 28d flexural strength, young's modulus and energy absorption capability of the mortars reinforced with the mechanically functionalized MWCNTs at an amount of 0.1 wt% increased by 120%, 124%, and 103% respectively. Finally, depending on the procedure of the functionalization, chemical or mechanical, a different effect on the intrinsic properties of MWCNTs was observed. The carboxylic groups attached to the surface of the chemically functionalized MWCNTs indeed provided them with the ability of a uniform and effective dispersion, without the need of a sonication procedure. On the other hand, it was found that functionalized MWCNTs do not always retain the electrical properties of pristine MWCNTs.

Effect of acoustic softening on the thermal-mechanical process of ultrasonic welding

Application of ultrasonic energy can reduce the static stress necessary for plastic deformation of metallic materials to reduce forming load and energy, namely acoustic softening effect (ASE). Ultrasonic welding (USW) is a rapid joining process utilizing ultrasonic energy to form a solid state joint between two or more pieces of metals. Quantitative characterization of ASE and its influence on specimen deformation and heat generation is essential to clarify the thermal-mechanical process of ultrasonic welding. In the present work, experiments were set up to found out mechanical behavior of copper and aluminum under combined effect of compression force and ultrasonic energy. Constitutive model was proposed and numerical implemented in finite element model of ultrasonic welding. Thermal-mechanical analysis was put forward to explore the effect of ultrasonic energy on the welding process quantitatively. Conclusions can be drawn that ASE increases structural deformation significantly, which is beneficial for joint formation. Meanwhile, heat generation from both frictional work and plastic deformation is slightly influenced by ASE. Based on the proposed model, relationship between ultrasonic energy and thermal-mechanical behavior of structure during ultrasonic welding was constructed.

Advanced cement based nanocomposites reinforced with MWCNTs and CNFs

Cementitious materials reinforced with well dispersed multiwall carbon nanotubes (MWCNTs) and carbon nanofibers (CNFs) at the nanoscale were fabricated and tested. The MWCNTs and CNFs were dispersed by the application of ultrasonic energy and the use of a superplasticizer. Mechanical and fracture properties including flexural strength, Young’s modulus, flexural and fracture toughness were measured and compared with similarly processed reference cement based mixes without the nano-reinforcement. The MWCNTs and CNFs reinforced mortars exhibited superior properties demonstrated by a significant improvement in flexural strength (106%), Young’s modulus (95%), flexural toughness (105%), effective crack length (30%) and fracture toughness (120%).

Optimization of method to quantify soil organic matter dynamics and carbon sequestration potential in volcanic ash soils

Volcanic ash-derived soils are important globally for their C sequestration potential and because they are at risk of compaction and degradation due to land use change. Poorly or non-crystalline minerals impart enormous capacity for soils to store and stabilize C, but also unusual chemical and physical properties that make quantifying meaningful soil C pools challenging. Here, we optimize a soil physical fractionation method to effectively assess soil organic matter dynamics in volcanic ash soils by first comparing three common methods for Andisols of the same soil series under three land uses. Components of those methods that (1) effectively isolated C pools of different size and turnover and (2) demonstrated potential sensitivity to land use change were then modified for a final, combined method. The isolation of C pools corresponding to fundamental mechanisms of protection within aggregates and organo-mineral control on the stabilization of C, which often function to the extreme in volcanic ash soils, underlie these modifications. Combined application of ultrasonic energy to disrupt aggregates and the removal of light fractions with sequential high density fractionation successfully isolated multiple C pools that ranged in radiocarbon-based turnover time from 7 to 1,011 year in the surface 0–15 cm of mineral soil in an undisturbed, native forest. Soil C accumulates as a result of high, continuous input that cycles through a transitional (century-scale) organo-mineral pool and then either becomes occluded and protected within aggregates (multiple centuries) or enters a continuum of organo-mineral and non-crystalline mineral-dominated pools (from centuries to millennium-scale). Comparison of relative C pool sizes and C isotope signature among soils from native forest, grazed pasture, and managed Eucalyptus plantation revealed the potential for making accurate, direct measurements of soil C change over time with land use and management change or disturbance regime.

Grinding a Hard-to-Grind Materials with Ultrasonic-Assisted Fluid

Grinding is one of the machining processes used in the manufacture of high-accuracy parts. When materials which easily adhere to the grinding wheel are used, such as aluminum, stainless steel, and titanium, wheel loading must be considered, as this could have a limiting effect. In this research, the application of ultrasonic energy to the grinding fluid is carried out with a specially-designed effector inserted into the fluid supply flow with the expectation that loading will be removed from the wheel. The experiment is carried out on stainless steel and pure titanium. The grinding force and accession of temperature are investigated during grinding, and the reduction of both grinding force and thermal escalation is confirmed. Burn marks on the ground surface of titanium are also prevented.

Ultrasonically assisted anchoring of biodegradable implants for chevron osteotomies - clinical evaluation of a novel fixation method.

Reconstructive osteotomies for the treatment of Hallux valgus are among the most prevalent procedures in foot and ankle surgery. The combination of biodegradable materials with an innovative method for fixation by application of ultrasonic energy facilitates a new bonding method for fractures or osteotomies. As clinical experience is still limited, the aim of this study was to assess the safety and performance of the SonicPin system for fixation of Austin/Chevron osteotomies. Chevron osteotomy was performed on 30 patients for the treatment of Hallux valgus. The used SonicPins were made from polylactide and are selectively melted into the cancellous bone structure during insertion by ultrasonic energy. Patients were followed for one year, which included X-ray and MRI examinations as well as evaluation of life quality by EQ-5D (EuroQol). The MRI after three months showed adequate bone healing in all cases and no signs of foreign body reactions, which was again confirmed by MRI 12 months postoperatively. The bony healing after 12 months was uneventful without any signs of foreign body reactions. In summary, based on the low complication rate and the significant improvement in health related quality of life (EQ-5D) reported in this study, fixation of an Austin/Chevron osteotomy with a SonicPin for treatment of Hallux valgus can be considered to be safe and efficient over the short term. Level of Clinical Evidence: Therapeutic Level III.

Ultrasonic assisted cleaning of high sulphur Indian coals in water and mixed alkali

The present investigation reports the application of ultrasonic energy (20kHz) to few high sulphur Indian coal samples in aqueous and mixed alkali media (1:1 KOH and NaOH) for removal of sulphur and ash for industrial applications. The study shows maximum removal of ash, pyritic sulphur, sulphate sulphur and total sulphur with 87.52, 83.92, 12.50 and 18.80% respectively. The XRD and FTIR spectral analyses reveal reduction in ash and different forms of sulphur contents in coals by use of ultrasonic energy. The changes in SEM morphology of the ultrasonicated coal samples are attributed to the occurrence of the cavitations in the coal structure. The ash fusion temperatures (AFT) and the calorific values of the ultrasonicated coal samples indicate the enhanced quality of these coals for utilization in power sector. The coal leachates after ultrasonication are found to be predominant in K, Ca and Mg, which can be discharged sustainably. The possible mechanism of coal cleaning by ultrasonic energy is also discussed in the paper.

The Inactivation of Enzymes by Ultrasound—A Review of Potential Mechanisms

The application of ultrasonic energy can inactivate many enzymes. The ultrasound shock waves produce cavitation and acoustic streaming in the liquid medium, which generates adequate mechanical, thermal, and chemical effects to inactivate enzymes. The extremely fast cycles of pressurization and depressurization and the resultant (localized) high temperature lead to rapid formation and collapse of bubbles. The rapid formation and collapse of bubbles is capable of breaking the hydrogen bonds as well as the van der Waals interactions in polypeptide chains. The application of ultrasound alters the secondary and tertiary structure of enzymes and leads to the loss in their biological activity. In this article, the authors review the recent advances made in the inactivation of common enzymes by the application of ultrasound alone or in combination with heat and pressure. The associated inactivation mechanisms and the factors affecting the enzyme inactivation are also reviewed.

Effect of ultrasonic laundering on thermophysiological properties of knitted fabrics

The paper focuses on the application of ultrasonic energy in textile laundering. In recent years, there has been an increasing interest in ultrasonic energy application in textile industry; however, the effect of ultrasonic laundering on the thermophysiological properties of knitted fabrics has not been studied yet. This study was conducted by using polylactic acid (PLA), cotton, polyethylene terephthalate (PET), and poly acrylic (PAC) fibres containing yarns and their blends. Knitted fabrics, single pique, were made from these yarns by using weft knitting machine. The fabrics were washed ten times for 15 and 60 minutes under 40 °C by using conventional and ultrasonic washing methods. The main aim was to determine the effect of washing methods on the thermophysiological properties of the fabrics. It is also aimed to analyse and evaluate the thermophysiological properties of the PLA fabrics. The incorporation of 100 % PLA and cotton/PLA yarns into single pique knitted fabrics has been attempted to produce for the first time and studied their thermal comfort properties. The results show that the washing processes have a critical importance for the tested fabrics in terms of thermal conductivity, thermal resistance, thermal absorbtivity, water vapour permeability, and heat loss. It has been also demonstrated that the fabric cleaning by using ultrasonic method enhanced the properties of tested fabrics such as thermal conductivity and % recovery. It was also noted that 15 minutes ultrasonically washed fabrics had significantly lower thermal resistance as compared to conventionally washed fabrics.

An overview of the welding technologies of CLAM steels for fusion application

China Low Activation Martensitic steel (CLAMs), a kind of RAFM steel with Chinese intellectual property rights, is considered as the primary structural material for the China-designed ITER test blanket module (TBM). As one of the key issues in the fabrication of the fusion reactor, the welding technologies of CLAMs are reviewed. Emphasis is placed on the weldability of CLAMs by different welding methods, and on the properties of as-welded and post-weld heat-treated joints. Recent highlights in research and development for the welding of CLAMs show that proper welding procedure could provide welds with adequate tensile strength but the welds exhibit lower impact toughness compared with the base metal. Post-weld heat treatment (PWHT) and the application of ultrasonic energy during TIG welding could dramatically improve impact toughness. Research also shows that welds in CLAMs have sufficient resistance to swelling under irradiation as well as suitable compatibility with liquid LiPb. The microstructure, mechanical and other physical properties of welds are significantly different from those of the base metal due to the complicated welding thermal cycle. The weld joint is the area most likely to fail one or more of the design requirements within the fusion reactor. Therefore significant additional research is necessary to ensure safe application of welded CLAM steel for fusion reactor construction.

Experimental Investigation of Mechanical Behavior of Carbon-Nanotube Reinforced Cement Mortar

In this study, effective dispersion of different amount of multiwall carbon nanotubes was achieved using a surfactant and in combination with the use of ultrasonic energy. The effects of surfactant and surfactant concentration on the plain cement mortar were investigated. Moreover, the mechanical behaviors of the carbon-nanotube reinforced composites were also analyzed. Experimental results indicate that the application of ultrasonic energy is absolutely necessary to produce a satisfactory dispersion of MWCNTs, and there exists an optimum weight ratio of surfactant to MWCNTs. It is found that the proper dispersion of MWCNTs can remarkably improve the flexural strength, compressive strength, and the toughness of the cement mortar composites.

Highly dispersed carbon nanotube reinforced cement based materials

The remarkable mechanical properties of carbon nanotubes (CNT) suggest that they are ideal candidates for high performance cementitious composites. The major challenge however, associated with the incorporation of CNTs in cement based materials is poor dispersion. In this study, effective dispersion of different length multiwall carbon nanotubes (MWCNTs) in water was achieved by applying ultrasonic energy and in combination with the use of a surfactant. The effects of ultrasonic energy and surfactant concentration on the dispersion of MWCNTs at an amount of 0.08 wt.% of cement were investigated. It is shown that for proper dispersion the application of ultrasonic energy is absolutely required and for complete dispersion there exists an optimum weight ratio of surfactant to CNTs. For a constant ratio of surfactant to MWCNTs, the effects of MWCNT type (short and long) and concentration on the fracture properties, nanoscale properties and microstructure of nanocomposite materials were also studied. Results suggest that MWCNTs improve the nano- and macromechanical properties of cement paste.

The effect of various mixing techniques on the surface microhardness of mineral trioxide aggregate

To evaluate the influence of various mixing procedures including ultrasonic vibration, trituration of customized encapsulated mineral trioxide aggregate (MTA) and condensation on the Vickers surface microhardness of MTA. ProRoot MTA Original, ProRoot MTA (white), MTA-Angelus (grey) and MTA White Angelus (white) were prepared using several mixing techniques including ultrasonic vibration, trituration of customized encapsulated MTA and conventional condensation. Twelve experimental groups (four materials: three techniques) were evaluated, each with 35 samples. All samples were incubated after preparation and subjected to Vickers surface microhardness testing after 4 and 28 days. Data was were subjected to a two-way anova. At 28 days, the surface microhardness value was significantly greater for all experimental groups compared to 4 days after mixing (P < 0.00001). The application of ultrasonic energy to MTA produced significantly higher surface microhardness values compared to the other mixing techniques at both 4 and 28 days (P < 0.0001). However, no significant difference existed between condensation and trituration techniques at both time intervals. Regardless of the mixing technique employed, a significant difference (P < 0.0001) was observed in surface microhardness value between all types of MTA apart from between Angelus grey and ProRoot white at both 4 and 28 days, both of which produced the highest values. Compared to trituration and condensation techniques, the application of ultrasonic energy to MTA produced a significantly higher surface microhardness value at both 4 and 28 days. Irrespective of mixing technique, ProRoot white and Angelus grey had the highest surface microhardness values. Trituration of encapsulated, premeasured MTA and water provides a standardiszed method of mixing that produces MTA slurries with more controllable handling characteristics.