Effect Of Ultrasonic Energy Research Articles

Ultrasonic Energy as an Agent to Aid Water Treatment in the Coagulation Process

The aim of the study was to estimate the effectiveness of ultrasonic coagulation aiding. The effect of ultrasound exposure alone and associated systems (ultrasound exposure/coagulant) on the contamination of natural water was examined. The evaluation of the test results was based on changes in indicators, such as TOC, color, turbidity, and electrokinetic potential. Three different coagulants were used in the tests of associated systems. The tests included basic processes related to volumetric coagulation, such as agitation, flocculation, and sedimentation. Sonication of water samples was carried out at a constant frequency of 22 kHz, variable vibration amplitude of 8–16 μm, and an exposure time of 1–5 min. The most efficient removal of organic contaminants from the water tested was achieved at a maximum amplitude of A = 16 μm, with effectiveness reaching 29% (TOC). In the tests of the associated systems, the effect of ultrasound exposure on the removal of water turbidity (an increase in the effectiveness of 25–35%) was generally greater than that on water color (8–21%). This relationship reflects the differentiated effect of ultrasonic energy on colloids of different stability. In removing turbidity, ultrasound exposure had the most favorable effect on aluminum sulfate. In respect of color, a better result was obtained using the modified coagulant. The possibility of reducing the coagulant dose confirmed the aiding effect of ultrasound. In the coagulation process, ultrasound exposure has a positive effect on the course of flocculation and the sedimentation of suspensions. In addition to the reduction in the doses of chemical reagents, it also leads to the modification of the post-coagulation sludge structure.

Effect of ultrasonic energy on the spot weldability of aluminum alloy AA6061

This study investigates the effects of superimposed ultrasonic vibration on resistance spot welding (RSW) of aluminum alloy AA6061-T6. A novel ultrasonically assisted resistance spot welding process, referred to as ultrasonic resistance welding (URW), is applied to weld AA6061 at various conditions and compared with the results from RSW. Lap shear tensile tests of URW welds show significantly improved mechanical properties, including higher strength, better ductility and higher amount of energy absorbed prior to failure compared with RSW welds. Optical micrographs of the weld cross section show that the ultrasonic vibration enhances nugget formation and minimizes porosities defects. Besides, equiaxed crystal structure is generally observed in the nugget center of URW welds whereas the majority of RSW fusion zone is dominated with columnar grain structure. In situ thermal imaging of the two processes shows a lower temperature distribution, smaller heating and cooling rates during URW. This is attributed to the ultrasonically assisted fracture and breakdown of surface oxides and contaminates, which reduces the contact resistance and accordingly heat generation rate.

Ultrasonic-assisted aging in friction stir welding on Al-Cu-Li-Mg aluminum alloy

Friction stir welding (FSW) on Al-Cu-Li-Mg aluminum alloy V-1469 (AA2195) has been carried out to find out the effect of ultrasonic energy on the microstructural evolution of the welded metal. It was found that ultrasonic-assisted FSW (UAFSW) reduced the recrystallized grain size in the stirring zone (SZ), facilitated strain-induced dissolution of both soluble and insoluble intermetallic precipitates, and enhanced solid solution grain recrystallization and precipitation of coherent metastable phases.

Ultrasonic assisted synthesis of Bikitaite zeolite: A potential material for hydrogen storage application

Li containing Bikitaite zeolite has been synthesized by an ultrasound-assisted method and used as a potential material for hydrogen storage application. The Sonication energy was varied from 150W to 250W and irradiation time from 3h to 6h. The Bikitaite nanoparticles were characterized by X-ray diffraction (XRD), infrared (IR) spectral analysis, and field-emission scanning electron microscopy (FESEM) thermo-gravimetrical analysis and differential thermal analysis (TGA, DTA). XRD and IR results showed that phase pure, nano crystalline Bikitaite zeolites were started forming after 3h irradiation and 72h of aging with a sonication energy of 150W and nano crystalline Bikitaite zeolite with prominent peaks were obtained after 6h irradiation of 250W sonic energy. The Brunauer–Emmett–Teller (BET) surface area of the powder by N2 adsorption–desorption measurements was found to be 209m2/g. The TEM micrograph and elemental analysis showed that desired atomic ratio of the zeolite was obtained after 6h irradiation. For comparison, sonochemical method, followed by the hydrothermal method, with same initial sol composition was studied. The effect of ultrasonic energy and irradiation time showed that with increasing sonication energy, and sonication time phase formation was almost completed. The FESEM images revealed that 50nm zeolite crystals were formed at room temperature. However, agglomerated particles having woollen ball like structure was obtained by sonochemical method followed by hydrothermal treatment at 100°C for 24h. The hydrogen adsorption capacity of Bikitaite zeolite with different Li content, has been investigated. Experimental results indicated that the hydrogen adsorption capacities were dominantly related to their surface areas as well as total pore volume of the zeolite. The hydrogen adsorption capacity of 143.2c.c/g was obtained at 77K and ambient pressure of (0.11MPa) for the Bikitaite zeolite with 100% Li, which was higher than the reported values for other zeolites. To the best of our knowledge, there is no report on the synthesis of a Bikitaite zeolite by sonochemical method for H2 storage.

The Effect of Ultrasonic Energy on the Enhancement of the Biodegradability of Food Waste

In this study, the effect of ultrasonic pretreatment on the physicochemical property changes and methane production potential of anaerobic digestion of food waste was investigated. The study, involving a laboratory experimentation by sonicating 200 mL of food waste sample, was investigated at different sonication times (2, 4, 6, 8, 10 min), and the specific energy input ranged from 5,396 to 25,997 kJ/kg total solid. The experimental results found that the mean particle size diameter (d50) of the ultrasonically treated food waste decreased from 59 to 21.9 μm with the specific surface area increasing from 0.523 to 1.2 μm2/g. This is evidenced in the food waste morphological structure changes from particles or granules varying in size and shape from small to large and round to oval or unsymmetrical shaped when the food waste samples were sonicated in the range of 2–10 min as shown by scanning electron microscopy. The value of soluble chemical oxygen demand was increased about 34–40% while the degree of disintegration was recorded as 57.15, 61.10, 71.08, 68.94, and 68.68%, respectively. The CODsolubilization was achieved around 11.4, 11.8, 13.4, 12.7, and 13.2%, when the food waste sample was sonicated at 2, 4, 6, 8, and 10 min, respectively. This CODsolubilization correlated well with DD when the linear relationship was shown by R2 = 0.945. The result shows that the use of sonicated food waste in the anaerobic digestion process has increased about 45.9, 40.3, 46.6, 64.4, and 70.5% of cumulative CH4 production rates in the food waste sample sonicated at 2, 4, 6, 8, and 10 min, respectively, when compared to the non-sonicated food waste sample.

The effect of ultrasonic energy on the separation of cytoplasmic RNA fractions

Plant tissue -4 days old germs of <i>Zea mays</i> and <i>Pisum sativum</i> were subjected to ultrasonic energy using generator with a constant frequency of 800 kHz. RNA was isolated by Mieczyński’s modification of the method described by Georgiev. Preparations of RNA were separated by electrophoresis on the coloured agar-gel. Depending on the degree of ultrasonication changes in three fractions of RNA: A<sub>1</sub> - 28 S, A<sub>2</sub> - 18 S and A<sub>3</sub> - 4 S were observed

Carbon nanofiber cementitious composites: Effect of debulking procedure on dispersion and reinforcing efficiency

Abstract The use of new reinforcing materials like carbon nanofibers (CNFs) makes it possible to produce cement based nanocomposites with revolutionary properties. However, in order to take advantage of the CNF’s excellent reinforcing efficiency it is necessary to achieve a uniform distribution in the matrix. In this work, nanofiber cementitious composites were produced containing CNFs at an amount of 0.048 wt.% of cement. To achieve good dispersion of the CNFs, a method utilizing a surfactant and ultrasonic processing, was employed. The method was optimized using two parameters: the effect of ultrasonic energy and the effect of surfactant to CNF (SFC/CNF) ratio. Initially, the SFC/CNF ratio on the dispersion of two types of CNFs, one subjected to a new special debulking method and one with minimal debulking process, was investigated. An ultrasonic energy of 2800 kJ/l and a SFC/CNF ratio close to 4.0 was found to be optimal for effective dispersion. Following these values, cement based nanocomposites reinforced with four types of CNFs, subjected to different debulking processes and having different morphology, were produced. Their nanostructure was studied using scanning electron microscopy (SEM). Their mechanical performance was evaluated using fracture mechanics tests. All four CNFs were found to control nanoscale cracking. As a result, both the flexural strength and the stiffness of the nanocomposites were significantly improved. Furthermore, the reinforcing efficiency of the CNFs in the cementitious matrix was shown to depend on the debulking procedure: at later ages, the use of the CNF subjected to the special debulking process was found to be more efficient in improving the mechanical performance of the nanocomposites.

Synthesis of NaP zeolite at room temperature and short crystallization time by sonochemical method

NaP zeolite nano crystals were synthesized by sonochemical method at room temperature with crystallization time of 3h. For comparison, to insure the effect of sonochemical method, the hydrothermal method at conventional synthesis condition, with same initial sol composition was studied. NaP zeolites are directly formed by ultrasonic treatment without the application of autogenous pressure and also hydrothermal treatment. The effect of ultrasonic energy and irradiation time showed that with increasing sonication energy, the crystallinity of the powders decreased but phase purity remain unchanged. The synthesized powders were characterized by XRD, IR, DTA TGA, FESEM, and TEM analysis. FESEM images revealed that 50nm zeolite crystals were formed at room temperature by using sonochemical method. However, agglomerated particles having cactus/cabbage like structure was obtained by sonochemical method followed by hydrothermal treatment. In sonochemical process, formation of cavitation and the collapsing of bubbles produced huge energy which is sufficient for crystallization of zeolite compared to that supplied by hydrothermal process for conventional synthesis. With increasing irradiation energy and time, the crystallinity of the synthesized zeolite samples increased slightly.

Unravelling the role of ultrasonic energy in the enhancement of enzymatic kinetics

The enzymatic hydrolysis of anabolic androgenic steroids excreted to urine as glucuronide conjugates has been recently reported to be improved by applying ultrasonic energy to the reaction medium. The hydrolysis time using β-glucuronidase from Escherichia coli K12 was reduced by a factor of six when ultrasonic energy was employed to enhance the enzymatic kinetic. In this study, the effect of ultrasonic energy on the enzymatic hydrolysis kinetic parameters, as well as on the enzymatic activity of β-glucuronidase from E. coli K12 was assessed. The study was conducted using the compounds 4-nitrophenyl-β-d-glucuronide and 4-nitrophenol. Experimental data suggested that the reaction follows the Michaelis–Menten kinetics type. In addition it was found that the ultrasonic energy affects the initial velocity of reaction, which is higher when ultrasound waves are employed when compared to the classical method of incubation at 55 °C. Moreover the values of Vmax and kcat are higher for the ultrasonic essay (Vmax(US) = 17.1 ± 0.8 μM min−1; kcat(US) = 340,523 min−1; Vmax(55 °C) = 14.8 ± 0.7 μM min−1; kcat(55 °C) = 295,187 min−1) whilst the Michaelis–Menten constant obtained for the two methodologies showed similar values (KM(US) = 94.7 ± 7.2 μM; KM(55 °C) = 92.5 ± 6.6 μM). Deactivation of the enzyme was also observed under ultrasonic energy, which was found particularly evident for experimental conditions with excess of substrate; enzymatic activity half-life time increased with the increase of the E/S ratio. This research work seems to support the idea that the use of ultrasonic energy affects the transition state of the enzymatic reaction and that mass transfer processes are also most likely enhanced.

Effect of ultrasonic energy on nanoscale interfacial structure in copper wire bonding on aluminium pads

The effect of ultrasonic vibration on nanoscale interfacial structure of thermosonic copper wire bonding on aluminium pads was investigated. It was found that bonding strength was determined by the extent of fragmentation of a native aluminium oxide overlayer (5–10 nm thick) on aluminium pads, forming paths for formation of intermetallic compound CuAl2 in areas of direct contact of bonded metal surfaces. The degree of fracture of the oxide layer was strongly affected by a level of ultrasonic power.

ENZYMATIC HYDROLYSIS OF STARCH BY USING A SONIFIER

In the present study, the ultrasonication method was used to investigate the effect of ultrasonic energy on the hydrolysis of corn, rice, and wheat starch by using the alpha-amylase enzymes produced by Bacillus species and Bacillus licheniformis. The effects of sonifier operation variables such as duty cycle and acoustic power rate on the stability of alpha-amylase enzymes and hydrolysis degrees of three types of starches were investigated at a temperature of 40°C and pH 6.5. To determine the effect of temperature with sonication on the hydrolysis process, wheat starch hydrolysis experiments were also carried out at a temperature of 50°C. Then, the relation between duty cycle and enzyme stability during hydrolysis for each enzyme at 50°C was expressed by a zero-order inactivation model.

Effect of ultrasonic energy in washing of medical surgery gowns

Today, the use of medical textiles is very important for health and hygienic purposes. Although some of medical textile materials are disposable, surgery gowns are usually laundered and re-used. After the laundering it is desirable to have these gowns keeping some of their properties such as anti-microbial and tenacity properties. For this in mind, different surgery gowns were washed and compared. In this work, a special blend of polyester carbon anti-microbial and other surgery gowns were stained with blood and later washed with both conventional method and with ultrasonic energy. The results were also analysed spectrophotometrically and the tenacity of the fabrics were determined.

Effect of Ultrasound on the Production Reaction Kinetics of Sodium Thiosulfate

AbstractIt is known that the production reaction of sodium thiosulfate which consists of the reaction of Na2SO3 with sulfur is considerably slow. Ultrasound energy was used to increase the conversion fraction of sulfur and to accelerate the production reaction of Na2S2O3, and the effect of ultrasonic energy on the reaction kinetics was investigated. The particle size, reaction temperature, concentration of Na2SO3 solution and amplitude of ultrasound power were chosen as parameters. The experiments were performed in the absence and presence of ultrasound. Considering the results the reaction is chemically controlled first order and the activation energy is equal to 42 kJ/mol in both cases. The results indicated that the ultrasound energy increased the reaction speed but it did not vary the activation energy. The effect of ultrasound is on the pre‐exponential factor A. Finally, an empirical relation is given which relates the rate constant to ultrasound power.

The effect of ultrasonic energy on lime slaking

Lime slaking is important for its use in a number of industrial applications. There are normally a number of factors that can influence the rate of the hydration of lime, which include, amongst others, production and storage conditions and the constitution of the water used in the slaking process. This paper describes an investigation of the effect of mode of agitation during the slaking process of the limes from different geological origins. During the investigation normal mechanical shaking was compared with ultrasonic agitation when the limes were contacted with water. It was found that the ultrasonic shaking enhanced both the rate and the degree of hydration of the different limes being slaked. The geological origin of the various limes also exerted an influence in the slaking process.

Effect of ultrasonic energy on coal extraction by specific solvents

AbstractCoals of three different ranks have been extracted by four different solvents, namely, pyridine, quinoline, tetralin and tetrahydroquinoline while being irradiated with ultrasonic energy in the 60 kHz range.The effect of initial particle size, coal rank and time of irradiation has been investigated.The effect of temperature on the highest yield systems for a particular coal has also been studied at 30°, 45° and 65°C.

The effect of ultrasonic energy on the creatine phosphokinase determination.

The effect of ultrasonic energy on the creatine phosphokinase determination.

The effect of ultrasonic energy on the extraction of anthraquinones from senna pericarps.

Abstract Ultrasonic irradiation increased the extraction rate of rhein glycosides, free anthraquinones and total water-soluble solids from whole senna pericarps, irrespective of the temperature conditions employed. An increase in ultrasonic power from 35 to 100 W increased the yield of extractable constituents over a 15 min period, the ratio of rhein glycosides to total water-soluble solids being higher in extracts prepared using ultrasound than in preparations obtained by simple maceration, but that ratio decreased slightly with an increase in ultrasonic power. Ultrasonic irradiation produced occasional visible damage to epidermal cell walls and the significance of this in the extraction of senna pericarps is discussed.

The diffusion of sennoside A through a cellulose membrane.

Abstract The diffusion rate of sennoside A through a cellulose membrane into water increased irrespective of the temperature conditions under which diffusion took place, when the membrane was irradiated with ultrasound. The results are consistent with the hypothesis of boundary layer disruption at the phase interface and their significance in the effect of ultrasonic energy on the aqueous extraction of senna pericarps is discussed.

Ultrasonic Degradation of Aspirin in Mixed Solvent Systems

The effect of ultrasonic energy on the degradation of aspirin in ethanol-water, diethyl ether-water, and diethylene glycol-water solvent systems at various concentrations and temperatures was studied. It was found that the application of ultrasound to a system undergoing degradation would cause an increase in the rate, but would maintain the same kinetic order as in the control system. The heat of activation seems to be lowered by the mechanical vibrations of the ultrasonic energy. It is postulated that the ultrasonic vibration increases molecular collisions and the movement of the products away from each other, thereby producing a change in the overall rate of reaction. As the concentration ratio was increased in the diethylene glycol system, the subsequent increase in viscosity had a damping effect on the ultrasonic vibration.

Effect of Ultrasound Energy on Hydrolysis of Aspirin

The effect of ultrasonic energy on the hydrolysis of aspirin solutions at various temperatures and pH values is described. The reaction kinetics followed a pseudo first-order rate, both with and without the influence of ultrasound. The rate of hydrolysis was increased in all cases by applying sound energy. A mathematical treatment of the data disclosed that the effect of ultrasonic energy on the hydrolysis rate is relatively constant and can be compared to the effect obtained by increasing the reaction temperature.