Duration Of Ultrasonic Treatment Research Articles

Effects of Ultrasonic Treatment on Grain Refinement and Gas Removal in Magnesium Alloys

The effects of ultrasonic treatment on grain refinement and hydrogen removal in three kinds of magnesium alloys—Mg-3Ca, Mg-6Zn-1Ca, and AZ80 alloys—were investigated in this study. After ultrasonic treatment, the grains of the magnesium alloys were refined to varying degrees. The degassing effect was characterized by measuring the densities and hydrogen content of ingots. The results indicated that the application of ultrasonic treatment in these magnesium alloys was able to remove hydrogen and obviously refine the microstructure. In this experiment, both the measurement of the density of the ingots and the solid-state hydrogen measurement reflected the degree of degassing. The highest degassing efficiencies were 53.8%, 67.5%, and 34.9% for the Mg-3Ca, Mg-6Zn-1Ca, and AZ80 alloys, respectively. The lowest hydrogen content of the AZ80 alloy reached 8.2 cm3/100 g, and the corresponding tensile strengths were 174 Mpa, 79 Mpa, and 6.2%, which represented increases of 41.5%, 38.6%, and 87.9%, respectively. The cavitation effect and acoustic streaming effect with an appropriate ultrasonic treatment duration resulted in grain refinement, degassing, and the uniform dispersion of second phases. This can significantly improve mechanical properties and provide a basis for industrial production.

Ultrasonic treatment duration: A nuanced parameter in synthesis affecting structural properties and ORR performance of KOH-activated carbon

In this study, we investigate the effects of the duration of ultrasonic treatment during the impregnation process of a carbon precursor with an aqueous alkaline solution on the structural and electrochemical properties of KOH-activated carbon materials. Our findings using polyacrylonitrile (PAN)-derived carbon materials reveal that extended ultrasonic treatment leads to a more consistent distribution of the activating agent, promoting more uniform surface activation. This leads to notable shifts in the material's structure and surface chemistry, thereby influencing its functionality as an electrode material in supercapacitors and its electrocatalytic activity in the oxygen reduction reaction (ORR). Our results indicate a 6 % difference in the specific surface area and an 8 wt% rise in oxygen content when comparing samples without ultrasonic treatment to those treated for 10 min. Moreover, the specific capacitance increases from 133.9 to 163.5 F g−1, and the ORR activity ascends from 1.88 to 2.23 mA cm−2. This research highlights the potential of ultrasonic treatment duration as a variable to fine-tune the structure and properties of porous carbon materials, emphasizing its scientific and technological significance in the production of stable porous carbon materials.

The effect of ultrasound on the quality indicators of food raw materials and finished products

The article presents the results of a study of the effect of ultrasonic treatment on changes in the quality of meat.In most of the previous studies on the use of ultrasonic treatment, a positive effect on the quality of meat and meat products was noted. Ultrasonic processing is widespread in accelerating technological processes, improving the functional, technological and structural and mechanical properties of meat.In the course of these studies, meat samples of various animal species were subjected to ultrasound exposure of various durations, after which changes in shear stress, moisture binding capacity and microbiological parameters of pork, beef, mutton and horse meat were determined. As a result, ultrasonic processing has reduced the stress of cutting all types of meat. The optimal duration of ultrasonic treatment has been determined, which increases the moisture binding capacity of meat. As the duration of ultrasonic treatment increased, a decrease in the number of pathogenic microorganisms in meat was observed.Based on the results of these studies, it was concluded that ultrasonic treatment is important for the meat industry, since this method can be used as a non-thermal effect to improve physical, biochemical and microbiological characteristics that increase the quality, safety and increase the shelf life of various meat products.

Optimizing sludge dewatering efficiency with ultrasonic Treatment: Insights into Parameters, Effects, and microstructural changes

Sludge dewatering plays a critical role in the efficient and cost-effective management of wastewater treatment plants. Ultrasonic treatment has emerged as a promising technique for improving dewatering processes. This study aims to evaluate the impact of ultrasonic treatment on sludge dewatering characteristics. A series of experiments were conducted to evaluate the dewatering characteristics of sludge under ultrasonic treatment. Experimental data was collected, and the effects of ultrasonic parameters on dewatering efficiency were analyzed. Ultrasound has the capacity to disintegrate sludge flocs, liberate tightly bound water, and enhance sludge dewatering capabilities. The application of ultrasound leads to the breakdown of sludge flocs, which facilitates a substantial amount of organic acids or carbonates. This, in turn, modifies the pH value of the sludge. Additionally, ultrasound induces instantaneous high temperature and pressure within the liquid phase, consequently elevating the temperature of the sludge slurry. Optimum ultrasound energy density and duration of ultrasound treatment exist. For the sludge samples analyzed in this investigation, it was determined that the optimal ultrasonic energy density is 9.8 W, while the optimal duration of ultrasound treatment is 30 s. Excessively escalating the sound energy density or prolonging the duration of ultrasound may yield unfavorable outcomes in terms of sludge dewatering effectiveness. To enhance sludge dewatering, it is crucial to select appropriate ultrasonic energy density and duration of ultrasonic treatment. This study demonstrates the positive impact of ultrasonic treatment on the dewatering characteristics of sludge. The findings provide valuable insights into the potential of ultrasonic technology for enhancing sludge dewatering.

Hydrometallurgical processing of ash and slag waste

This work assesses the possibility of hydrometallurgical processing of ash and slag waste in order to extract rare and rare earth elements. The ash and slag waste from the Chita CHPP-2 combined heat and power plant was used as a research object. Inductively coupled plasma atomic emission spectroscopy (ICP-AES) was used to determine the elemental chemical composition of coal combustion products. To preconcentrate rare and rare earth elements, magnetic separators were used to isolate the -0.5+0.3 mm and -0.3+0.1 mm grain size fractions of ash and slag waste. The leaching of rare and rare earth elements from the studied samples was investigated using sulfuric, hydrochloric, and nitric acids, as well as an aqua regia solution, in combination with simultaneous ultrasonic exposure. It was determined that electromagnetic separation of the -0.5+0.3 mm and -0.3+0.1 mm grain size fractions of ash and slag waste significantly concentrates rare and rare earth elements in the magnetic fraction, including titanium (up to 25%), zircon (up to 33%), yttrium (up to 50%), lanthanum (up to 150%), and cerium (up to 5%). It was determined that an increase in the duration of ultrasonic treatment during the leaching of metals from ash and slag waste with sulfuric acid resulted in a uniform 7.25-fold increase in gallium content (from 0.008 to 0.058 g/dm3). Additionally, when decomposed with aqua regia, a 3-fold concentration of the same element was observed (from 0.008 to 0.024 g/cm3), while ultrasonic treatment offered only a slight increase in concentration. When leaching with sulfuric acid (the duration of ultrasonic exposure is 5 minutes), a 4-fold increase in the rubidium content was observed (from 0.108 to 0.457 mg/dm3). Therefore, the most effective method for extracting rare and rare earth elements from the ash and slag waste of Chita CHPP-2 involves acid leaching combined with electromagnetic separation and ultrasonic pulp leaching.

The Effect of Variable Parameters on Carbon Residue of Iraqi Vacuum Gas Oil using Ultrasound Techniques

An ultrasonic treatment was applied to the vacuum gas oil at intervals of 5 to 30 minutes, at 70°C. In this work, the improvement of the important properties of Iraqi vacuum gas oil, such as carbon residue, was studied with several parameter conditions that affect vacuum efficiency, such as sonication time (5, 10, 15, 20, 25, and 30) min, power amplitude (10–50%). After ultrasonic treatment, the carbon residue of vacuum gas oil was evaluated using a Conradson carbon residue meter (ASTM D189). The experiment revealed that the oil's carbon residue had decreased by 16%. As a consequence of the experiment It was discovered that ultrasonic treatment might reduce the carbon residual and density of oil samples being studied. It also noticed that the carbon residue reduced with increased ultrasonic treatment duration and power. The mechanical mixing and cavitation brought about by ultrasonic processing led to a number of modifications in the gas oil molecules. The properties of a typical molecular structure were altered on a microscale.

Surface quality improvement of steel parts by combined laser-ultrasonic treatment: determination algorithm of technological parameters

To provide the quality of the surface layer and improve operational properties, a combined laser-ultrasonic surface hardening and finishing technology of steel products is proposed. This work is devoted to determining the range of rational parameters of laser heat treatment and ultrasonic impact treatment for enhancing the complex hardening process of AISI 1045 steel and AISI D2 steel. Laser surface transformation hardening was carried out with a constant temperature strategy using a fiber laser and scanning optics at a heating temperature of 1200–1,300 °C and a processing speed of 40–140 mm/min. Ultrasonic surface hardening and finishing were performed on technological equipment with an amplitude of ultrasonic vibration of 18 μm and a load of the ultrasonic tool of 50 N. The ultrasonic treatment duration varied from 60 to 180 s. The results showed that laser-ultrasonic treatment leads to an increase in the hardening intensity by more than 200 %, forming a hardening depth of 200–440 μm. Combined treatment leads to a significant increase in wear resistance due to the formation of ultrafine-grained martensitic microstructure with hardness (58–60 HRC5) in the near-surface layer. The combined laser-ultrasonic hardening process control algorithm for surface treatment of structural and tool steels is proposed, limiting the heating temperature, the duration of laser (ultrasonic) exposure, and the vibration amplitudes of the ultrasonic horn. Laser-ultrasonic treatment will allow the formation of a surface layer with a given set of properties, providing increased wear and corrosion resistance. The developed technology can be used for surface hardening and finishing of large-sized steel products in the mechanical engineering industry.

Electrochemical Behavior of Nanocrystalline NiMoO<sub>4</sub> Hydrate Modified by Ultrasound

To improve the specific capacitance, power and energy of electrical energy storage devices, in particular hybrid capacitors, various methods of cathode material modification are used. One of the methods of modifying nanostructured materials without applying high temperatures, pressures and long reaction times is ultrasonic treatment. Although the interaction of ultrasound with the structure and surface of electrode materials is well enough studied, there are few works that investigate the optimal duration of ultrasonic treatment and its relationship with the capacitive characteristics of these materials. Therefore, we investigated the efficiency of ultrasonic dispersion of nanocrystalline nickel molybdate hydrate for 15, 60 and 90 minutes. The appearance of two cathodic peaks on cyclic voltammetry patterns was analyzed and the charge / discharge mechanism of the electrode based on nanocrystalline NiMoO4 hydrate was presented. Based on the results of potentiodynamic and galvanostatic studies the specific capacitances of the initial NiMoO4 and the material modified by ultrasound for 15, 60 and 90 minutes were calculated. The proton diffusion coefficients of nickel molybdate hydrate were determined on the basis of the Randles–Sevcik equation. NiMoO4 subjected to ultrasonic dispersion for 60 min as a cathode material in a hybrid electrochemical system was tested.

Effect of Ultrasonic Degassing on Mg-Ca Binary Alloy by Ultrasonic Treatment

The effect of ultrasonic treatment parameters, including ultrasonic treatment duration, frequency resonance, and treatment temperature, on the degassing of Mg-3.03Ca alloys was investigated. The results indicated that the optimum degassing efficiency could be obtained under the ultrasonic resonant condition. When applying ultrasonic treatment for 90 s with 150 W at 700 °C, the minimum hydrogen content and the highest degassing efficiency are obtained, respectively (42.8 cm3/100 g and 27.5%). The ultrasonic treatment can remove the gas from the melt and refine the microstructures. Finally, the mechanism of ultrasonic degassing and refinement was analyzed.

Multi-mode S-type ultrasound-assisted protein extraction from walnut dregs and in situ real-time process monitoring

This study aimed to investigate the impact of multi-mode S-type ultrasound treatment on the protein extraction level of walnut dregs. The structural properties of the walnut protein (WP) were characterized, and the correlation between protein structure and extraction level was analyzed. The in situ real-time monitoring model for the ultrasound-assisted WP extraction process was established by a miniature fiber near-infrared (NIR) spectrometer. Results showed that the protein yield, purity, and comprehensive extraction index (CEI) of extracted WP were 71.07 %, 72.69 %, and 71.72, respectively, under optimal conditions (dual-frequency 20/28 kHz, ultrasonic treatment duration 30 min, and ultrasound power density 120 W/L). The secondary structure of extracted WP displayed that the proportion of α-helix and β-sheet reduced, while the contents of β-turn and random coil increased after ultrasonic treatment. Besides, sonication decreased the disulfide bond content and increased free sulfhydryl (-SH) and surface hydrophobicity compared to the control. The microstructures of WP confirmed that appropriate sonication could unfold the protein aggregates and reduce the particle size. The extraction level of WP is positively correlated with the -SH content (p < 0.01). The quantitative prediction model of Si-PLS for -SH content in the ultrasound-assisted WP extraction process was established and performed a good correction and prediction performance (Rc = 0.9736; RMSECV = 0.446 μmol/L; Rp = 0.9342; RMSEP = 0.807 μmol/L). This study exploited a high-efficiency way for the WP extraction industry, and provided theoretical support for the development of the intelligent system in industrial protein extraction process.

Influence of chitin nanofibrils ultrasonic treatment on structure and properties of chitosan-based composite materials

The influence of ultrasonic treatment parameters of chitin nanofibrils aqueous suspension on structure, strength and deformation properties of chitosan-based composite films and fibers was investigated. Model calculations of ultrasound-induced cavitation parameters in the aqueous suspension of the chitin nanofibrils showed that an increase in the field power up to 630 W led to destruction of the cavity, to an increase in the temperature in the vicinity of cavitation area (up to 507 °C) and, as a consequence, to destruction of chitin glycoside ring (which is confirmed by the IR data). The results of light scattering, IR spectroscopy, and electron microscopy investigations indicated that the optimal duration of ultrasonic treatment of the chitin nanofibrils aqueous solution was 4–10 min (depending on oriented state of the scaffold). Tensile strength of the composites was 130 ± 11 MPa (films), 226 ± 4.8 MPa (fibers); deformation at break was 43 ± 7.5% (films), 10 ± 0.6% (fibers).

Experimental study of the rheological properties and stability of highly-concentrated oil-based emulsions

This study presents a systematic investigation of viscosity and rheological properties of several dozen emulsions and nanoemulsions. The concentration by volume of the oil in emulsions varied from 20% to 80%. Low-viscosity mineral oils were used for emulsion formation and an aqueous solution of calcium chloride was used as the second medium. The volumetric concentration of emulsifiers varied from 1.5% to 4.5%. Three types of mineral oil, as well as various emulsifiers, are considered. The effect of the volumetric content and base oil type, the emulsifier type and concentration and the ultrasonic treatment duration on colloidal stability, rheological properties and droplet size of the resulting emulsion has been studied. It is shown that emulsions are considered to be non-Newtonian fluids with apparent elastic properties at oil concentration less than 35 vol%. All other things being equal, the average droplet size in the emulsion increases with an increase in the base oil viscosity. The use of ultrasonic treatment makes it possible to reduce the average droplet size in the emulsion by 4.5 times and to reduce its viscosity by 1.5 times.

Ultrasound-assisted dewatering of crude oil from Kumkol oilfield

Reducing the water content of crude oil is a necessary step in preparing oil for transportation and processing. This task is complicated by the presence of stable water-in-oil emulsions. The most widely used approach to oil demulsification is exploring chemical demulsifiers. However, the high cost and impossibility of regenerating the latter require the search for new ways to destroy water-oil emulsions. One of the promising areas is the use of ultrasound. This paper presents the results of studies on the ultrasonic treatment of four samples of emulsions with different water content (8.74; 15; 25 and 30 vol.%) based on oil from the Kumkol oilfield (Kazakhstan). Samples of emulsions were subjected to ultrasonic action at a frequency of 40 kHz for 5-60 min at a temperature of 70±1°C, followed by settling for 40 min at the indicated temperature. The influence of the initial water content in the emulsion, the acoustic intensity, as well as the duration of ultrasonic treatment on the dewatering ratio was investigated. It was found that the residual water content in the oil was 5.04- 7.82 vol.%. Ultrasonic treatment of crude oil from the Kumkol oilfield can be used for preliminary dewatering, to subsequently reduce the consumption of chemical demulsifiers.

Ultrasound-assisted dispersive solid-phase extraction combined with reversed-phase high-performance liquid chromatography-photodiode array detection for the determination of nine biogenic amines in canned seafood

This work describes an ultrasound-assisted dispersive solid-phase extraction method combined with reversed-phase high-performance liquid chromatography-photodiode array detection (UADSPE-RPLC-PDA) for the determination of nine common biogenic amines (BAs) in canned seafood. The pretreatment extraction solvent, ultrasonic treatment duration, and derivatization conditions were optimized. The method was validated on the basis of the limit of detection (LOD), limit of quantification (LOQ), precision, and accuracy and successfully applied to analyze four canned fish, two canned shrimp and four canned shellfish samples. LODs of 0.08–0.25 mg kg−1 were achieved, and the correlation coefficient of determination was 0.9994–0.9997. The method had high precision and accuracy, with relative standard deviations (RSDs) and recoveries of 0.44 to 6.83% and 72.57 to 99.74%, respectively, suggesting the effectiveness of ultrasound-assisted extraction at increasing the solubility of the target analytes in the solvent system and the feasibility of UADSPE-RPLC-PDA for determining trace BAs in canned seafood.

Dynamics of Mass Transfer through the Interface between Immiscible Liquids under the Resonance Effect of Ultrasound

The specific features of the resonance behavior of the radial vibrations of a droplet of liquid placed into an immiscible liquid have been considered based on the derived nonlinear equation that takes into account a stimulating effect in the form of acoustic pressure that periodically varies with time. Analytical formulas have been derived for the rate of mass transfer as a function of the amplitude of the oscillations of acoustic pressure and the duration of ultrasonic treatment of the volume of an extractor. The threshold values of the amplitude of ultrasound and the characteristic time (increment) of parametric instability have been found. A method has been proposed for varying the pumping frequency in order to achieve the maximum efficiency of extraction under the stimulating effect of ultrasound.

Study of the stability of the emulsion of ultramicroheterogeneous flotation reagents obtained by the method of ultrasonic dispersion

The results of studies of the stability of the microemulsion of an ultramicroheterogeneous flotation reagent obtained from a mixture of oil from the Zhanazhol field and butyl xanthate (BX) in the following ratios are presented: oil: BX = 1: 1; oil: BX = 2: 1; oil: BX = 4: 1. It was found that the microemulsion has the greatest stability when the ratio of oil: BX = 4: 1, which was 99.3% after 120 hours of exposure. The supposed emulsifying effect of butyl xanthate in symbiosis with natural emulsifiers of the oil itself over newly formed globules of ultrasonic (US) dispersion was found. At an ultrasonic treatment power of 250 W for 10 min, a microemulsion with an average globule size of 123.4 nm was obtained. It is shown that an increase in the duration of ultrasonic treatment for more than 10 minutes does not have a significant effect on the stability of the obtained microemulsion of an ultramicroheterogeneous reagent

The transformation and degradation of Nafion® solutions under ultrasonic treatment. The effect on transport and mechanical properties of the resultant membranes

This work addresses the study of the effect of ultrasonic (US) treatment on the properties of alcohol solutions of perfluorinated sulfonic acid polymer Nafion® and cast membranes. The effect of the duration of US treatment on the physico-chemical properties (water uptake, transport and mechanical properties) of the resulted membranes is described for the first time. Upon the US treatment, viscosity of the polymer solutions irreversibly decreases due to deagglomeration and rupture of macromolecular chains. As a result of the US treatment, mechanical properties of the Nafion® membranes are deteriorated. The dependences of water uptake and conductivity of the Nafion® membranes in the proton form on sonication time pass the maximum (at 30–45 min). Due to the sonication of polymer solutions, proton conductivity of the membranes increases by 40–45%. Upon extended sonication, the content of sulfonic acid groups decreases, and carboxyl groups are formed at the ends of macromolecules. Thus, water uptake of the membranes prepared from the polymer solutions after the US treatment for 60 min decreases, and conductivity of the obtained membranes in the H+-form is reduced. However, for the Nafion® membranes in the Na+-form, as the duration of the US treatment is extended, their conductivity and diffusion permeability tend to increase due to the enhanced connectivity of pores and channels as well as due to the participation of carboxyl groups in the ionic transport. Upon extended sonication, selectivity of the cation transfer through the membranes is reduced. The results of this work highlight the importance of the proper selection of favorable conditions of the US treatment of the solutions of perfluorinated sulfonic acid polymers for the preparation of hybrid membranes and for the development of catalytic layers of membrane-electrode assemblies for fuel cells.

Heatproof Relaxation of Welding Stresses Openwork Designs of Large Size Ultrasonic Field

Designed experimental setup, and a prototype of the original devices for athermic relaxation of thermal residual stresses in openwork welded constructions of large dimensions for the rational use of energy high-frequency acoustic (ultrasonic) fields, conducted laboratory studies and pilot tests in real conditions of production. Ultrasonic relaxation when welding thin-walled constructions standard openwork rolled steel profiles 10 large dimensions (up to 3 x 10 m). It has been established that with a decrease in the time of ultrasonic relaxation, the efficiency of its use decreases somewhat. Therefore, in an industrial environment, it is advisable to use the duration of ultrasonic treatment in the range of 0.02-0.04 min per mm of weld length.

A research into the distribution of silicium dioxide nanoparticles in the mixing water

Introduction. The co-authors studied suspensions of silicium dioxide nanoparticles in the water. The application of suspensions helps to most effectively add nanoparticles to slip ceramic mixtures and mixtures that contain concrete. A review of publications has proven that Russian and foreign researchers are willing to learn more about nanoparticles used to modify various materials. Particles having different chemical properties are applied depending on the types of problems to be solved. The method of ultrasonic dispersion of fillers in the matrix material is widely used; surfactants stabilize suspensions and mortars. Silicon dioxide, being one of the cheapest ultra-dispersed powders, has been proven as an active filler designated for building materials.&#x0D; Materials and methods. A method of ultrasonic dispersion was used to uniformly distribute nanoparticles in the water. A surfactant was added to the suspension to reduce the reaggregation of particles and to rise the stability of suspensions in the course of time. The turbidimetric method was employed to control the nanoparticle distribution efficiency in the suspension, and a spectrophotometer was used to identify the dimensions of solid particles by measuring the optical density.&#x0D; Results. The co-authors have proven the efficiency of the ultrasonic method in distributing nano-sized particles over the water. The suspensions, developed by the co-authors, were used to mold samples of ceramics; a scanning electron microscope and a nozzle, designated for the identification of chemical compositions, were used to identify dimensions of nanoparticle conglomerates in the matrix. The co-authors identified the concentration of OP-10 surfactant that was optimal for the destruction of conglomerates in the suspension; the impact of the ultrasonic treatment duration was assessed in respect of the suspension.&#x0D; Conclusions. The research findings can be contributed to ceramic production technologies for versatile nanoparticles to be employed to modify materials.

The effect of ultrasonic treatment on the phase composition of hydroxylapatite synthesized using a hydrothermal technique

The influence of the duration of ultrasonic treatment after hydrothermal synthesis of hydroxylapatite (HA) samples synthesized in the Ca(NO 3 ) 2 ‒(NH 4 ) 2 HPO 4 ‒NH 4 OH precursor system on the phase composition and crystallinity of the synthesized samples is considered. HA samples were investigated using X-ray diffraction and infrared Fourier spectroscopy. The study showed that ultrasonic treatment, regardless of the duration, does not affect the phase composition and crystallinity of the obtained HA samples. In all the studied samples, the presence of the HA phase Ca 10 (PO 4 ) 6 (OH) 2 with a crystallinity of 0,97 was established.