Action Of Ultrasonic Waves Research Articles

Examination of aqueous solution with a concentration of PAA WF1 high-molecular weight polyacrylamide polymer using a cavitation noise spectrum

This paper presents spectral characteristics obtained for various intensities of ultrasounds for water and aqueous solution with a concentration of PAA WF1 (CH2CHCONH2CH2)n n = 30,000 − 50,000 (molecular weight 4.4 · 106 g/mol) with the concentrations of 0.25% and 0.1%. The experiment aimed at examining the dependence of the intensity of cavitation and the area of the biggest changes in the characteristics of cavitation noise spectrum on the intensity of ultrasounds was carried out as the first. Then, there were performed tests that consisted in sonication of the solution at a constant intensity of ultrasounds. The aim was to investigate the changes occurring in the cavitation clouds as well as the changes in the characteristics of the cavitation noise spectrum along with a change in the properties of the solution subjected to continuous action of ultrasonic waves. Finally, there were presented the spectral characteristics at different intensities of ultrasounds in order to determine the impact of the continuous sonication on the test solution.

Electronic rat-control devices – solution or scam? Results of field trials and a summary of the literary data

The electronic rat-control devices are humane means of controlling harmful rodents without toxic substances. They are relatively inexpensive and very easy to use and have gained increasing popularity in recent years. Although they have been introduced long ago in the practice of deratization, scientific information about their real effectiveness is scarce and at the same time very controversial. The purpose of this study was to evaluate the repellent efficiency of an electronic device using the combined action of ultrasonic waves, light signals, and electromagnetic field change in practice. Two field trials were carried out on a cattle-breeding farm and a feed warehouse inhabited by brown rats (Rattus norvegicus) and roof rats (Rattus rattus). Repellent efficacy was determined by comparing the indicators evaluating the presence and activity of rodents during the pre-testing period before the inclusion of the device and after its activation during the test period. A lack of repellent effect was found in both field studies. The results obtained are supported by an analysis of the scientific literature confirming the inadequate effectiveness of electronic rat control devices in practical conditions. Emphasis is placed on the deficiencies and the need for regulatory adjustments governing the control and admission of electronic devices to control rats on the market.

Microstructure evolution of SiC/SiC joints during ultrasonic-assisted air bonding using a Sn–Zn–Al alloy

Direct soldering of SiC ceramic in air at 230°C was achieved using a Sn–9Zn–2Al alloy assisted by ultrasonic wave within seconds. Experimental results indicated that a sound metallurgical bond was formed between the SiC ceramic and Sn–9Zn–2Al alloys. The dependence of interfacial microstructure evolution on ultrasonic action duration time was investigated. Two types of interfacial structures at the interface were observed as the ultrasonic action duration time increased. An amorphous SiO2 layer was identified at the interface for ultrasonic exposures of 1s, which was the oxide layer formed on the SiC ceramic surface during heating. A layer of amorphous alumina with a thickness of ~ 6.8nm formed at the interface under ultrasonic action for over 4s. The shear strength of joints could reach up to 44MPa. The formation of the alumina layer at the interface was attributed to the redox reaction of Al from the filler metal and SiO2 on the SiC ceramic surface under the action of ultrasonic waves. The rapid interfacial reaction was principally induced by the acoustic cavitation and streaming effects at the liquid/solid interface.

P.1.h.009 Local inactivation of G protein-coupled receptor 88 restores motor and cognitive functions impaired in a rat model of schizophrenia

all experiment procedure to demonstrate their effectiveness. The expression of genes coding serotonin receptors (5-HT1, 5-HT2 subtypes), SERT, BDNF and VEGF were measured in prefrontal cortex, midbrain and hippocampus using Quantitative real-time PCR analysis. Moreover, immunohistochemical assay of BDNF and VEGF expression in rat’s hippocampus (CA1) was carried out. Analysis of the expression of genes involved in pathogenesis of depression was performed to show structural validity of model. Diffusion tensor imaging study of the corpus callosum of rats with depression-like behavior were performed with a 7.0 Tesla Bruker BioSpin ClinScan MRI tomograph equipped with a head gradient insert. Results: Action of ultrasonic waves of variable frequency led to a marked reduction of social activity (total time of social contacts, s) in the Social Interaction Test in the experimental group 107±9.8 compared to the control group 216±30.5, (p< 0.001). Fluoxetine and Tianeptine led to restoration of social activity to control levels (228±21.4 and 236±40.6, respectively). Bupropion had no effect on social activity − 142±30.5. In the Porsolt Test, experimental animals showed a significantly higher immobility time (s) (213±15.6) compared to the control group (83±16.3, p< 0.001). Administration of Fluoxetine, Bupropion and Tianeptine reduced the immobility time to control values (129±22.5; 70±16.8; 58±17, respectively). Study of anhedonia development revealed a significant decrease in sucrose preference index in experimental group compared to the control group. RT-qPCR gene expression analysis showed increased expression of SERT gene in all studied structures, decrease expression of 5-HT2A in prefrontal cortex and midbrain, increase 5-HT1A in hippocampus and decrease BDNF in hippocampus of rats after ultrasound. Immunohistochemical assay showed decrease BDNF expression in hippocampus in rats after ultrasound radiation. Diffusion tensor imaging study of the corpus callosum showed decrease numbers of white matter hyperintensities in rats with depression-like behavior, a phenomenon suggested to be linked with white matter pathology. Conclusion: The obtained data allow to conclude that this model meets the main requirements set to animal models of neuropsychiatric disease (face, predictive and construct validity) and can be used in studies of affective disorders and in pre-clinical development of new antidepressants.

Supercritical carbon dioxide extraction of capsaicinoids from malagueta pepper (Capsicum frutescens L.) assisted by ultrasound

Extracts from malagueta pepper (Capsicum frutescens L.) were obtained using supercritical fluid extraction (SFE) assisted by ultrasound, with carbon dioxide as solvent at 15MPa and 40°C. The SFE global yield increased up to 77% when ultrasound waves were applied, and the best condition of ultrasound-assisted extraction was ultrasound power of 360W applied during 60min. Four capsaicinoids were identified in the extracts and quantified by high performance liquid chromatography. The use of ultrasonic waves did not influence significantly the capsaicinoid profiles and the phenolic content of the extracts. However, ultrasound has enhanced the SFE rate. A model based on the broken and intact cell concept was adequate to represent the extraction kinetics and estimate the mass transfer coefficients, which were increased with ultrasound. Images obtained by field emission scanning electron microscopy showed that the action of ultrasonic waves did not cause cracks on the cell wall surface. On the other hand, ultrasound promoted disturbances in the vegetable matrix, leading to the release of extractable material on the solid surface. The effects of ultrasound were more significant on SFE from larger solid particles.

Heat Transfer Enhancement by Ultrasound Pressure Waves in Liquid Water: A Cooling Method for New Electronic Components

The objective of this work is to study the increase of the convective heat transfer coefficient in the presence of ultrasound waves and, in particular, to find a relationship between the ultrasonic power and the effective pressure of water. The tests have focused on the heat exchange by natural convection, in single-phase conditions, at atmospheric pressure, between a cylinder, heated by means of the Joule effect, and distilled water, with and without the action of ultrasonic waves. The variables involved in the heat exchange have been varied within the range allowed by the experimental apparatus and the convective heat transfer coefficient has been maximized. The specific thermal flow has been chosen in a range compatible with applications in the field of electronics. For the first time the pressure of water at various ultrasonic power levels has been measured, in the vicinity of the cylindrical surface, thanks to the collaboration with the Naval Experimentation and Support Center (CSSN) of the Italian Navy in La Spezia, Italy.

EPA-0256 – Behavioral patterns and expression of genes coding serotonin receptors, serotonin transporter and brainderived neurotrophic factor in rats with ultrasound induced depression

The aim of our study was to investigate the effects of continuous action of ultrasonic waves of variable frequencies on behavior of rats in ’classical’ tests used to reveal depression-like behavior, to evaluate the influence of different antidepressants on rates and to analyze expression of several genes involved in pathogenesis of depression. : Rats in individual cages were exposed to ultrasonic irradiation of variable frequencies (20–45 kHz) for 21 days. 48 male non-pedigree albino rats were divided into 5 groups: non-ultrasound-saline, ultrasound-saline, ultrasound-fluoxetine, ultrasound-bupropion and ultrasound-tianeptine. Administration of each drug was carried out daily from the first to the last day of the experiment. Behavioral tests were include: Social Interaction test, Porsolt and Anhedonia Test. Than rats were decapitated and expression genes coding serotonin receptors (5HT1, 5HT2 subtypes), SERT and BDNF were measured in prefrontal cortex, midbrain and hippocampus using Quantitative real-time PCR analysis. Depression-like behavior manifests itself in reduced social activity in Social Interaction Test, increased immobility in Porsolt Test and lower sucrose consumption in Sucrose Preference Tests. The administrated antidepressants demonstrated their effectiveness. RT-qPCR gene expression analysis showed increased expression of SERT gene in all studied structures; decrease expression of 5-HT2A in prefrontal cortex and midbrain, increase 5HT1A in hippocampus. Expression of gene coding BDNF in hippocampus is significant decreased. The obtained data allow to conclude that this model meets the main requirements set to animal models (face, predictive and construct validity) and can be used in pre-clinical studies of new antidepressants.

Acousto-optic effect in nematic liquid crystals: Experimental evidence of an elastic regime

We show that the experimental data for the action of ultrasonic waves on homeotropically aligned nematic-liquid-crystal cells reported by Kapustina, in Akust. Zh. 54, 900 (2008) [Acoust. Phys. 54, 778 (2008)] can be explained in the framework of the director-density coupling theory in the regime of low acoustic intensity. This result therefore provides support for the hypothesis that the interaction between sound and nematic liquid crystals is dominated by an elastic energy.

Effect of the coupled action of ultrasonic waves and advanced oxidation reaction on the properties of bottom sediments originating from trout culture

The objective of this study was to determine the effect of preliminary ultrasound treatment of bottom sediments, a factor enhancing the reaction of advanced oxidation, on changes in the properties of sediments originating from the intensive aquaculture of rainbow trout. Experiments were conducted on a laboratory scale in model reactors with an active volume of 1.0 L, either under conditions of exposure to the ultrasonic field alone or under conditions of exposure to both the ultrasonic field and a chemical reagent: Fe3+/H2O2. The results we achieved showed that preliminary ultrasound treatment of bottom sediments increased the advanced oxidation reaction yield and consequently improved the physicochemical properties of the sediments. The highest yield was obtained upon 15-min ultrasound treatment at a Fenton reagent dosage of 1.5 g Fe3+ L−1 and g H2O2 L−1. These conditions enabled a 43% reduction in the concentrations of organic compounds in the filtrate, shortened the capillary suction time (CST) by 93%, decreased the concentration of volatile substances in the sediments by 13% and decreased the levels of total nitrogen in sediments by 9% and of total phosphorus in the filtrate by 21%, and additionally caused a decrease in the mineral and dry matter content in the sediments.

IMPROVEMENT OF QUALITY AND COOKING CHARACTERISTICS OF BROWN RICE USING ULTRASONIC TREATMENT

Ultrasonic technology has promising potentials in terms of improving the sensory characteristics, cooking and nutritional properties of brown rice. The rice samples (variety M202) were treated with an ultrasonic system with frequencies of 16 and 20 kHz for four exposure durations, 15, 30, 45, and 60 min at water temperature of 25 and 40°C. Optimum cooking time, water uptake ratio, length expansion ratio and volume expansion ratio and microstructure were evaluated for treated samples and compared with untreated samples. The microstructure of the treated brown rice surface was examined using Scanning Electron Micrograph. Results indicated that the natural morphology of rice bran layer was changed by dynamic mechanical deformation action of ultrasonic waves. This led to improve the cooking quality and reduce cooking time of brown rice. The optimum cooking time of treated brown rice ranged from 24 to 28 min and from 22 to 24 min at water temperature of 25 and 40oC, respectively. Meanwhile the optimum cooking time of white rice and untreated brown rice were 22 and 48 min, respectively. High correlations were found between the cooking time and cooked rice percentage under tested conditions. It has been concluded that ultrasonic treatment could be used to shorten the cooking time and improve cooking properties and quality of brown rice.

Preparation of refractory calcium aluminate cement using the sonochemical process

Calcium aluminate cements (CAC) were prepared using the sonochemical process, followed by heat treatment. A study was made of the action of ultrasonic waves and the influence of thermal treatment conditions on two initial molar compositions of 1:1 and 1:2 of calcia:alumina. The aqueous suspension containing the raw materials (A-50 alumina and CaO) was subjected to an ultrasonic bath, followed by drying and burning at 1000, 1200 and 1300 ºC. These cements were characterized by SEM, XRD and the mechanical strength was evaluated by splitting tensile tests, using commercial cement as a reference. Furthermore, the phases were semi-quantified using the Rietveld method. The results show that hydration and sonochemical action increased the reactivity of the raw materials during firing and that phase formation is dependent on the thermal treatment conditions. The CAC cements were obtained at temperatures at least 200 ºC lower than those used in conventional methods, indicating the potential of this route of synthesis.

Behavioral Patterns and Expression of Genes Coding Serotonin Receptors in Rats with Ultrasound Induced Depression

Aims: The aim of our study was to investigate the effects of continuous action of ultrasonic waves of variable frequencies on behavior of rats in classical tests used to reveal depression-like behavior, to evaluate the influence of different psychotropic drugs on rates of these tests and to analyze expression of several genes involved in pathogenesis of depression. Study Design: Rats in individual cages were exposed to ultrasonic irradiation for 21 days.

Human blood group typing based on digital photographs of RBC agglutination process

A method for the monitoring of the human erythrocyte agglutination reaction in vitro, which is the basis for determining the human blood type (group), is proposed. The method is based on a statistical analysis of digital photographs of the agglutination process. It is experimentally shown that this analysis of photographs makes it possible to determine the probability that the agglutination reaction of erythrocytes of the studied specimen of blood with corresponding isohemagglutinating sera does occur. To increase the rate of the agglutination reaction of erythrocytes and to improve the sensitivity of the method of monitoring, the bioobject under study is subjected to the action of ultrasonic waves, as was previously proposed by the authors, and the result of the erythrocyte agglutination reaction is read optically. It is shown that, in principle, the method of statistical processing of digital photographs can be used to develop devices for automatic human blood typing in the AB0 and Rh systems.

A novel method for preparing Al matrix surface composites

In situ Al 3Ti particles reinforced Al surface composites were prepared by means of ultrasonic treatment in this paper. The microstructure and phases of the composites were investigated using optical microscope, SEM, and XRD. A novel horn crucible was designed and fabricated specially for this experiment. The results show that in situ Al 3Ti particles were moved to the bottom of specimen under the action of ultrasonic wave. The ultrasonic treating leads to the decrease of viscosity and the increase of the fluidity of metal melt, which accelerated the movement of the second phase particles in metal melt under the force fields of gravity and buoyancy.

Emulsification characteristics of three- and two-phase emulsions prepared by the ultrasonic emulsification method

Diesel engines exhausting gaseous emission and particulate matter have long been regarded as one of the major air pollution sources, particularly in metropolitan areas, and have been a source of serious public concern for a long time. The emulsification method is one of the potentially effective techniques to reduce emission pollution from diesel engines. Ultrasonic waves are a kind of sound waves with a frequency larger than 20 kHz, and they cannot be detected by the human ear. The phenomena of cavitation and hot spots produced by the rather violent action of ultrasonic waves can cause rapid chemical and physical reactions. This allows immiscible liquids to be well stirred with each other by means of ultrasonics. An ultrasonically vibrating machine that provides ultrasonic waves of a 40-kHz frequency was employed to prepare two- and three- phase emulsions in this experimental study. The fuel properties and the emulsion stability of the diesel emulsions were measured and analyzed. Experimental results show that the ultrasonic emulsification method successfully prepared two- and three-phase emulsions with tiny dispersed-phase droplets that are very evenly distributed in the outer oil or water phase. The ultrasonic processing time, quantity and HLB of the emulsifying agent were noted to have determinative influences on the formation of the emulsion and the fuel properties. A longer ultrasonic processing time caused less un-emulsified diesel fuel, smaller sizes and a more even distribution of dispersed-phase droplets in the outer oil phase and larger emulsion viscosity. However, a longer ultrasonic processing time also produced a larger temperature rise in the emulsion, leading to the deterioration of the emulsion stability. The O/W emulsion was found to have the lowest percentage of separation and thus the highest emulsion stability among the O/W/O, O/W and W/O emulsions. In addition, in comparison with the W/O emulsion, the O/W emulsion was shown to have a smaller size and a more even distribution of the dispersed-phase droplets. It also had a lesser rise in emulsion temperature when the ultrasonic processing time increased. The control of the ultrasonic processing time is important to successfully prepare the three-phase O/W/O emulsion. Too long a vibration time at the second-stage of emulsification is shown to cause the dispersed-phase pellets to contract and congregate with the inner-phase droplets. The three-phase emulsion structure then finally disappears and transforms into a two-phase emulsion. The addition of 2% by volume of the emulsifier mixture of Span80 and Tween80 with a HLB = 8, as suggested by this study for the preparation of stable two- and three-phase emulsions, were observed to have the lowest percentage of separation of the W/O and O/W/O emulsions. For preparing a stable O/W emulsion, the proportion of the emulsifier could be as low as 1.5% by volume. The percentage of separation of the O/W/O emulsion was lower and less influenced by the change in emulsion temperature than was the W/O emulsion with the same water content. However, the O/W/O emulsion was found to have a larger viscosity and a more significant variation of its viscosity, depending on the ultrasonic processing time, than the W/O emulsion.

Heterolaser frequency tuning under the action of ultrasonic waves

A new principle of the diode laser frequency tuning has been developed and implemented. According to this, the laser frequency is tuned by alternating strain in the active region of an InGaAsP/InP laser heterostructure emitting in a wavelength range of 1.3–1.8 µm. The strain is induced through the excitation of bulk ultrasonic waves in these heterostructures by means of a specially developed technique. Data on the influence of the alternating strain, induced by the bulk ultrasonic waves, on the spectral characteristics of laser radiation are presented. Estimates based on these data show that the frequency tuning range amounts to ΔF≈110 GHz for an acoustic wave with the frequency f=6.5 MHz and a power of about 1 W.

Variation of the reflection coefficient of semiconductors in a wavelength range from 0.2 to 20 μm under the action of ultrasonic waves

The effect of ultrasonic waves on the spectral coefficient of radiation reflection from the surface of semiconductors used in solar energy converters is considered. A change in the reflectance of semiconductors before and after ultrasonic treatment is determined. It is shown that acoustic stimulation of the semiconductor surface and subsurface layers determines the radiation reflection conditions.

Effect of ultrasonic wave on the degradation of polypropylene melt and morphology of its blend with polystyrene

A new method using high intensity ultrasonic wave has been developed for the degradation of polymer melt in an intensive mixer. For the effective transfer of ultrasonic energy, experimental apparatus was specially designed so that polymer melt can be in direct contact with the ultrasonic horn. In this research, we observed that the significant degradation of polypropylene (PP) melt in a mixer occurs due to the action of ultrasonic wave without any aid of additives or solvents. To compare the degradation efficiency of ultrasonic irradiation with that of peroxide, additional experiments were performed to practice the peroxide-aided degradation by mixing 1 part of dicumyl peroxide with PP in the mixer. It was also found that the direct sonication on polymer mixture in melt state reduces the domain sizes and stabilizes the phase morphology of the blend. It is suggested that ultrasound assisted melt mixing can lead to in situ copolymer formation between the components and consequently provide an effective route to compatibilize immiscible polymer blends.

Sonophotocatalytic destruction of organic contaminants in aqueous systems on TiO2 powders

The effect of ultrasound on the photodegradation of salicylic acid on four commercial titania powders was studied. The system exhibiting the highest enhancement was isolated. The use of ultrasound during photocatalysis had a pronounced effect on the rate and efficiency of salicylic acid destruction as compared with UV-light photocatalysis alone. The possible reasons of the increased activity under ultrasonication were proposed: aggregate breakage and photocatalytic utilization of species produced by the ultrasound. The combination of the action of ultrasonic waves and UV-assisted photocatalysis yielded synergistic effects for the catalysts with smaller particle size (such as Hombikat), while no enhancement was observed for the largest particle size photocatalyst (Aldrich anatase). Degussa P25 exhibited the highest overall activity for the degradation of salicylic acid and moderate enhancement of activity by ultrasound. The presence of intermediates in the bulk solution was observed during the purely photocatalytic degradation of phenol. The presence of ultrasound, however, allows to eliminate the toxic intermediates by the sonolysis in the bulk solution.

A comparative study between classical stirred and ultrasonically-assisted dead-end ultrafiltration

The aim of this work was to determine mass transfer coefficients in the cases of ultrasonically-assisted and classical stirred dead-end ultrafiltration. A comparative study was then performed, and mass transfer coefficients obtained under ultrasonic conditions are described by an empirical model. This correlation results from an analogy with what is observed using a stirred cell and involves the ultrasonic power as the main parameter. The hydrodynamics are assumed to depend on the intensity of the ultrasound effects illustrated by the agitation arising within the cell. This agitation is due to convective currents as well as physical effects due to cavitation. The concentration polarization phenomenon is therefore affected by this action of ultrasonic waves.