Effect Of Ultrasonic Cavitation Research Articles

Application Research Progress of Nanomaterial Graphene and its Derivative Complexes in Tumor Diagnosis and Therapy.

Functional nanomaterial graphene and its derivatives have attracted considerable attention in many fields because of their unique physical and chemical properties. Most notably, graphene has become a research hotspot in the biomedical field, especially in relation to malignant tumors. In this study, we briefly review relevant research from recent years on graphene and its derivatives in tumor diagnosis and antitumor therapy. The main contents of the study include the graphene-derivative diagnosis of tumors in the early stage, graphene quantum dots, photodynamics, MRI contrast agent, acoustic dynamics, and the effects of ultrasonic cavitation and graphene on tumor therapy. Moreover, the biocompatibility of graphene is briefly described. This review provides a broad overview of the applications of graphene and its derivatives in tumors. Conclusion, graphene and its derivatives play an important role in tumor diagnosis and treatment.

A "lysosomal bomb" constructed based on amorphous calcium carbonate to induce tumor apoptosis by amplified sonodynamic therapy

The acidic nature of malignant tumors leads to increased drug sequestration and the evasion of apoptotic damage, which is further exacerbated by abnormal lysosomes in tumor cells. In this study, a "lysosomal bomb" will be constructed using a type of acid-neutralized amorphous calcium carbonate (ACC) to encapsulate the sonosensitizer protoporphyrin IX (PpIX), and then coated with homologous tumor cell membranes to increase water solubility and homologous targeting. The PpIX-ACC@CMs designed in this paper are popcorn-like structures, which can not only neutralize the tumor's acidic microenvironment to balance the pH value and release excess Ca2+, but also cause lysosomal dysfunction and achieve drug lysosomal escape to increase drug accumulation. Additionally, the CO2 gas nucleus produced by the acid reaction of ACC can increase the ultrasonic cavitation effect to amplify the sonodynamic therapy (SDT) effect. In vitro and in vivo experiments demonstrated that PpIX-ACC@CMs, serving as a "lysosomal bomb," successfully localized to lysosomes of tumor cells and exhibited lysosomal escape ability through its acid reaction ability, achieving excellent SDT efficacy under ultrasound stimulation. Furthermore, exogenous Ca2+ overload also increased the likelihood of tumor calcification, which could contribute to in vivo tumor inhibition and facilitate CT medical imaging to monitor treatment efficacy.

Ensuring the normalization of the aero-ionic regime in production areas by means of ultrasonic air ionization

The results of studies on the normalization of the aeroionic regime in rooms under ultrasonic ionization of humidified air are presented. The increase in the concentration of negative aeroions under these conditions by the combined effect of the balloelectric effect and ultrasonic cavitation is substantiated. It has been established that when distilled water is used as a source of air ions under the action of a 10 W ultrasonic generator at a distance of 0.5 m, the concentration of negative air ions increases almost sixfold. At the same time, due to the joint effect of ultrasonic cavitation in the surface layer of water and the balloelectric effect, no generation of ozone and nitrogen oxides is caused. It is proved that with a decrease in the degree of water mineralization, the concentrations of negative and positive aeroions increase due to changes in the physicochemical properties of water and the resulting mechanochemical phenomena. The mechanism of formation of air ions in the air of industrial premises under the combined action of the balloelectric effect and ultrasound is proposed. It is substantiated that the quality of the air ionic composition of industrial premises air improves at a temperature of demineralized water of 20-25 °C and a directed air flow of 6 m/s towards the working area with the combined effect of ultrasound and balloelectric effect, which contributes to the improvement of sanitary and hygienic working conditions. The structure of an automated system for controlling the aeroionic regime of the working area of industrial premises with artificial ionization of humidified air using an aeroion generator and a ventilation system is proposed. This will allow monitoring and processing of information on technological, electrical and microclimatic parameters, adjusting, coordinating and jointly controlling the ventilation system devices and the ultrasonic generator of air ions.

Development and performance investigation of a novel ultrasonic-assisted non-contact membrane distillation process to prevent membrane fouling

A novel non-contact membrane distillation (NCMD) process is proposed that prevents membrane fouling by preventing direct physical contact between the feed and membrane. The feed channel of the NCMD module is equipped with an ultrasonic transducer that provides high-frequency mechanical oscillations to the feed film, which forms a fine mist of droplets and water column. Experiments are conducted to determine the feed height required to maximize the evaporation rate, and the effects of feed temperature, flow rate, and ultrasonic power on the permeation flux. The results reveal that the highest permeation flux occurs at a feed height of 20 mm, and an increase in the feed height and flow rate decreases the ultrasonic cavitation effect, while a higher feed temperature and ultrasonic power significantly increases the permeation flux. At the feed temperature of 60 °C, feed flow rate of 1.0 L/min, and ultrasonic current of 600 mA, the permeation flux is 6.3 kg/m2h, which is 8.4 times greater than that of the NCMD process without ultrasonic treatment. The corresponding specific energy consumptions with and without the ultrasonication are 647 and 6028 kWh/m3, respectively. Moreover, the long-term experimental results indicate that the proposed system is unaffected by high feed concentrations.

Effect of organic solvent additives on the enhancement of ultrasonic cavitation effects in water for lithium-ion battery electrode delamination

Ultrasonic delamination is a low energy approach for direct recycling of spent lithium-ion batteries. The efficiency of the ultrasonic delamination relies both on the thermophysical properties (such as viscosity, surface tension, and vapour pressure) of the solvent in which the delamination process is carried out, and the properties of the ultrasound source as well as the geometry of the containment vessel. However, the effect of tailoring solutions to optimise cavitation and delamination of battery cathode coatings has not yet been sufficiently investigated. Acoustic detection, high-speed imaging, and sonochemiluminescence (SCL) are employed to study the cavitation processes in water-glycol systems and identify the effect of tailoring solvent composition on cavitation strength. The addition of small volume fractions of organic solvent (ca. 10–30 vol%), including ethylene glycol or glycerol, to the aqueous delamination solution were found to significantly improve the delamination efficiency of lithium-ion battery cathode coatings due to the alteration of these thermophysical properties. However, greater volume fractions of glycol decrease delamination efficiency due to the signal-dampening effect of viscosity on the ultrasonic waves. The findings of this study offer valuable insights for optimising ultrasonic bath solution composition to enhance film delamination processes.

Effect of Low-Temperature Argon Plasma and Ultrasonic Cavitation on the Course of Burn Wound Healing

Background: Various physical phenomena come into use in medicine; however, to date, universal physical methods have not been developed to optimize the course of the wound healing at all treatment stages. In combustiology, the first stage of burn treatment is debridement; then it is important to create an optimal biological environment, normalize blood circulation, suppress pathogenic flora, and stimulate proliferative processes in the wound.Objective: To determine the effectiveness of low-temperature argon plasma (LTAP) and ultrasonic cavitation in deep burn wound treatment based on clinical observations and cytological findings.Materials and methods: We studied impression smears from burn wounds of 36 patients with deep burns of various etiologies who were treated using LTAP and ultrasonic cavitation in the Thermal Injuries Unit at the Saint Petersburg I.I. Dzhanelidze Research Institute of Emergency Medicine (Saint Petersburg, Russian Federation) between 2022 and 2023.Results: We found that cytogram findings in the study area changed from the inflammatory type to the regenerative-inflammatory one on day 3-7 when LTAP and ultrasonic cavitation were used, while such change in the control area was observed only after 10 days of treatment. Thanks to the use of LTAP and ultrasound after necrosectomy for deep dermal burns, the wound preparation for autologous skin grafting takes less time than it does with standard methods of local burn wound care. Ultrasonic cavitation should be used in cases of severe exudation and slough, whereas LTAP should be used when reparative processes in a burn wound slow down.Conclusions: Burn wound treatment using ultrasonic cavitation and LTAP enables to prepare the wound surface for autologous skin grafting with a high engraftment rate. The procedure allows to effectively and atraumatically debride the wound and suppress pathogenic microflora. Further research is planned in patients with large deep burn wounds.

Research on a harmless treatment method for oily sludge in coal chemical wastewater and the pollutant transformation mechanism of oily sludge during the treatment process

This study developed an ultrasound synergistic subcritical hydrothermal treatment method (U-SHT) to address the challenges posed by the high oil and water content, complex composition, and hazardous nature of oily sludge (OS) generated during the pretreatment of coal chemical wastewater. The study investigated the efficiency of this method for the harmless disposal and resource recovery of OS, and the migration-transformation mechanism of hazardous organic pollutants in OS. The findings revealed that U-SHT achieved a removal efficiency of chemical oxygen demand in OS of 91.16 %, an oil resource recovery efficiency of 96.60 %, and a residual oil rate of 0.28 %, meeting API emission standards. Further research indicated that the solubilizing effect of the surfactant on the oil enhanced the demulsifying effect of ultrasonic cavitation on the emulsified structure of OS, enabling ultrasound to efficiently release and disperse pollutants within OS. This promoted the decomposition and transformation of pollutants under subcritical hydrothermal conditions, with synergistic removal efficiencies for typical pollutants such as long-chain alkanes, polycyclic aromatic hydrocarbons, and phenols reaching 96.61 %, 97.63 %, and 97.76 %, respectively. Economic evaluation indicated that the cost of OS treatment was $29.66/m3, significantly lower than existing methods, demonstrating promising practical application prospects.

Mechanical properties of polymer composite films with ZnO nanoparticles synthesized in low-temperature plasma under ultrasonic cavitation

Abstract In this study, polymer nanocomposite materials consisting of the copolymer of ethylene and vinyl acetate as a matrix and nanoparticles of zinc oxide as a filler have been obtained and examined by physicochemical and mechanical methods. Zinc oxide nanoparticles used in this study were fabricated using the plasma discharge under the effect of intensive ultrasonic cavitation. To ensure that resulting nanocomposites will acquire homogeneous distribution of filler nanoparticles, solution technology was utilized followed by the melt compounding technique, and also nanoparticles treated and non-treated with ultrasound were applied. The fabricated samples of nanocomposite material films were examined by X-ray phase analysis, then X-ray fluorescence analysis as well as scanning electron microscopy. The differences between the samples were demonstrated: when the nanoparticles without ultrasonic treatment were used, the particles were found to be more strongly aggregated within the bulk of the composite material and the average size of particles was visually larger in comparison to the sample filled with nanoparticles subjected to ultrasonic action. Finally, studies of the tensile strength and relative deformation of the samples were carried out. From the results of mechanical tests, it can be seen that, according to both studied parameters, there is an optimal concentration of ZnO nanoparticles. For tensile strength, the highest result was obtained at a concentration of nanoparticles of 3%, and for the relative elongation to rupture of the sample, the highest value was achieved at a concentration of nanoparticles of 2%.

Oxygen-defect bismuth oxychloride nanosheets for ultrasonic cavitation effect enhanced sonodynamic and second near-infrared photo-induced therapy of breast cancer

Sonodynamic therapy (SDT) relies heavily on the presence of oxygen to induce cell death. Its effectiveness is thus diminished in the hypoxic regions of tumor tissue. To address this issue, the exploration of ultrasound-based synergistic treatment modalities has become a significant research focus. Here, we report an ultrasonic cavitation effect enhanced sonodynamic and 1208 nm photo-induced cancer treatment strategy based on thermoelectric/piezoelectric oxygen-defect bismuth oxychloride nanosheets (BNs) to realize the high-performance eradication of tumors. Upon ultrasonic irradiation, the local high temperature and high pressure generated by the ultrasonic cavitation effect combined with the thermoelectric and piezoelectric effects of BNs create a built-in electric field. This facilitates the separation of carriers, increasing their mobility and extending their lifetimes, thereby greatly improving the effectiveness of SDT and NIR-Ⅱ phototherapy on hypoxia. The Tween-20 modified BNs (TBNs) demonstrate ∼88.6 % elimination rate against deep-seated tumor cells under hypoxic conditions. In vivo experiments confirm the excellent antitumor efficacy of TBNs, achieving complete tumor elimination within 10 days with no recurrences. Furthermore, due to the high X-ray attenuation of Bi and excellent NIR-Ⅱ absorption, TBNs enable precise cancer diagnosis through photoacoustic (PA) imaging and computed tomography (CT).

Multi-modal triggered-release sonodynamic/chemo/phototherapy synergistic nanocarriers for the treatment of colon cancer.

Most colon cancer patients are diagnosed at an advanced stage, with a grim prognosis. In clinical, various combination therapies have been employed to enhance the efficacy of colon cancer treatment. The essence of combined treatment is the judicious selection and combination of various treatment units. Phototherapy (PT), sonodynamic therapy (SDT), and chemotherapy are treatment modalities that rely on the active molecules to treat tumors, and have been demonstrated to synergistically enhance tumor treatment efficacy. However, the differences in the metabolism of active molecules and hypoxic microenvironment of tumors have limited the synergistic effects of the aforementioned methods. To address this significant issue, in this study, we utilized polydopamine (PDA) as the encapsulated material to form a rigid shell that contains the therapeutic molecules IR-780 and methotrexate (MTX) on the surface of perfluorohexane (PFH) microdroplets through self-assembling method to develop an SDT/chemotherapy/PT combined nanoparticles (SCP NPs). Transmission electron microscopy (TEM) revealed that the nanoparticles exhibited a hollow shell structure, with an average size of approximately 100nm. SCP NPs have excellent stability and biocompatibility in both in vitro and in vivo. The absorption and emission spectrum of the loaded IR-780 did not exhibit any significant shift, and the photothermal temperature rose to 92°C. Their ultrasonic cavitation effect was good and their cell inhibitory effect of MTX was maintained. SCP NPs can achieve multi-modal triggered release through ultrasound, laser irradiation, and pH, ensuring a simultaneous accumulation of therapeutic molecules in the tumor area and effectively alleviating tumor hypoxia. Additionally, both the near-infrared fluorescence (NIF) signal and the ultrasonic cavitation signal of the nanoparticles can be utilized for tracking and monitoring treatment efficacy. Most notably, SCP NPs exhibited outstanding synergistic treatment effects at low intervention levels, resulting in a 67% cure rate of tumors. These results provide an experimental basis for developing the new clinical treatments for colon cancer.

Microstructure evolvement and wear properties of Ni60-based coating by ultrasonic power-assisted laser cladding

Ultrasonic vibration is known to cause significant refinement of microstructure, the effect of ultrasonic power on grain size, grain orientation and Schmid factor by laser cladding in the Ni60/WC composite coating was studied systematically. Meanwhile, the effect of microstructure on wear properties and hardness was elucidated. The results show that the performance of the cladding layer is the best when the ultrasonic power is 600 W, which is due to the combined effect of ultrasonic cavitation and acoustic flow. The average grain diameter is refined from 28.36 μm to 23.02 μm, and the refinement range is 18.9%. The formation of low Angle grain boundaries (LAGBs) is promoted by ultrasound, and the dislocation density is increased. The texture strength of the coating is distributed over {100}, {110} and {111} surfaces, and the strength decreases from 12.307 to 5.447 The microhardness is increased by 16% (from 768.85HV1 to 896.95HV1), the wear mechanism gradually from adhesive to abrasive wear and the average friction coefficient decreases from 0.47 to 0.216 with the increase of ultrasonic power, which improve the wear resistance of the coatings. Based on the understanding of microstructure evolvement, the grain refinement mechanism effected by ultrasonic power was explained from the aspect of cavitation processes.

К ВЫБОРУ РАСТВОРА ДЛЯ КАВИТАЦИИ В КОМПЛЕКСНОМ ЛЕЧЕНИИ ПОСЛЕРОДОВОГО ЭНДОМЕТРИТА

Relevance. Postpartum endometritis is an infectious and inflammatory process in the endometrium with possible involvement of the myometrium. The main components of the treatment of the disease are antibiotic therapy and removal of necrotic contents of the cavity of the postpartum uterus. From the point of view of caring for the organ, ultrasonic cavitation looks preferable. To increase its effectiveness, various solutions with antiseptic, immunomodulatory or other properties can be used. Aim. The purpose of our study was a comparative assessment of the effectiveness of the use of various liquids during ultrasonic cavitation in the treatment of postpartum endometritis. Materials and methods. 80 patients with mild and moderate severity of the disease were examined and treated. The patients were divided into 4 groups of 20 women: 1) patients of the 1st group received treatment according to the clinical recommendations of the Ministry of Health of the Russian Federation; 2) patients of the 2nd group underwent ultrasound cavitation of the uterine cavity using 0.9% sodium chloride solution; 3) patients of the 3rd group underwent ultrasound cavitation followed by additional irrigation of the uterine cavity 0.25% sodium deoxyribonucleate solution; 4) ultrasound cavitation of the uterine cavity was performed in patients of the 4th group using 0.9% furacilin solution. Results. On the 7th day of treatment for postpartum endometritis, all patients showed an improvement in well-being and objective indicators. At the same time, incomplete reduction of uterine soreness during palpation by the 7th day in patients of the 1st and 3rd groups led to an increase in bed days in these groups. In patients of group 1, there was a slower dynamics of blood parameters such as leukocyte count, C-reactive protein and erythrocyte sedimentation rate. The degree of reduction of tumor necrosis factor alpha and interleukin-10 was the lowest in group 1 and the highest in group 4. The bed day turned out to be the smallest in group 4 and the largest in group 1. Conclusions. Ultrasound cavitation of the uterine cavity significantly increases the effectiveness of complex therapy of postpartum endometritis and shortens the duration of treatment of patients, enhances the positive effect of ultrasonic cavitation by using 0.9% furacilin solution in a dilution of 1: 5000 as a cavitation liquid. Irrigation of the uterine cavity with a solution of sodium deoxyribonucleate does not significantly affect the healing process.

Forming a disordered atomic layer to bond TiN or AlN ceramic with Sn[sbnd]9Zn metal under ultrasonication

A disordered atomic layer instead of traditional intermetallic compounds is formed in the bonding interface of ceramic and metal in the metallization of ceramics under ultrasonication. A deep understanding of the bonding mechanism between poor-wetted ceramics and low-temperature metals remains limited with regard to high metallization efficiency and nanoscale bonding structure. In this work, the metallization of AlN and TiN ceramics was realized using Sn9Zn metal with the aid of ultrasonication. The microstructure, energy, and element sources of the ceramic/metal interface were analyzed. Results show that a nanoscale amorphous layer is formed between the ceramics and the metal, and this layer can bond easily with AlN or TiN and Sn9Zn because of the irregular arrangement of its atoms. Some dispersed nanocrystals are also present in the amorphous bonding layer. The thermal effect of ultrasonic cavitation produces a high temperature above 106 K, which provides the energy for the bonding of AlN or TiN with Sn9Zn. O and Zn accumulate in the Sn-9Zn/AlN bonding layer. Zn originates from Sn9Zn. O could be from the O2 dissolved in the liquid solder or the O2 adhering to the ceramic. A small amount of AlN decomposes because of its high ΔG of decomposition. However, TiN decomposes into Ti and N2 under the extreme condition caused by ultrasonic cavitation. The accumulated Ti in the Sn-9Zn/TiN bonding layer originates from TiN. The source of the accumulated O is the same as that of Sn-9Zn/AlN bonding layer.

Effect of cooling rates and Fe contents on microstructure evolution of Al-Cu-Mn-Mg-Fe-Si alloys

During the solidification process, the recycled Al-Cu alloys form coarse Fe-rich phases, which seriously deteriorate the mechanical properties of the alloy. The study employed optical microscope (OM), scanning electron microscopy (SEM) with energy dispersive spectroscopy (EDS), and synchrotron X-ray imaging to investigate the impact of cooling rate and Fe contents on the growth of Fe-rich phases, Al2Cu, and pores in recycled Al-Cu-Mn-Mg-Fe-Si alloys under synergistic effect ultrasonic melt processing (USMP) and Al-Ti-B. USMP can homogenize the distribution of TiB2 particles and provides more nucleation sites for the formation of Fe-rich phases. Under the synergistic effect of USMP and Al-Ti-B, increasing the cooling rate,the volume fractions of Fe-rich phases in 0.7FeUB (0.7 wt%Fe + USMP + Al-Ti-B) and 1.2FeUB (1.2 wt%Fe + USMP + Al-Ti-B) alloys decreased from 8.92% and 16.52% to 8.03% and 14.73%, respectively. The volume fraction of Al2Cu increased from 4.06% and 3.13% to 4.37% and 3.54%, respectively. Furthermore, the three-dimensional (3D) morphology of Fe-rich phases and Al2Cu became more compact and uniform. The volume fraction of pores in the 1.2FeUB alloy decreased from 0.412% to 0.072%. In-situ synchrotron X-ray radiography revealed that increasing cooling rates led to increased nucleation undercooling of primary α-Al and Fe-rich phases. These phenomena can be attributed to the combined effects of ultrasonic cavitation, ultrasonic streaming, and an increased cooling rate. These factors serve to homogenize the alloy composition, ensure uniform distribution of TiB2 particles, inhibit element diffusion, reduce solute segregation, and ultimately lead to the refinement of the grain size, α-Al, Fe-rich phases, and Al2Cu, while also inhibiting pore growth.

Carbon-dot/attapulgite composite sonocatalytic towards efficient indigo-containing wastewater degradation based on the cavitation mechanism

Catalytic degradation is an effective method to treat indigo carmine (IC) in wastewater, while high-performance catalyst materials need to be explored. Herein, a facile “spot-heating” synthesis method was employed, whereby the carbon dots (CDs) sonosensitizer was loaded onto the surface of attapulgite (ATP) with ultrasonic cavitation effect, resulting in a composite sonosensitizer ec-CDs/ATP (where ec-CDs represent CDs prepared from ethanol (e) and citric acid (c)). ATP served as a good carrier promotes uniform dispersion of CDs. Benefiting from the large specific surface area, more active sites on the surface of ec-CDs/ATP were exposed, which promotes efficient degradation performance for IC, with a 20 % improvement in performance compared to the reported pure CDs or composite CDs photocatalysts (Bi2O3/dots, Cl-dots). The selective deactivation reactions and relative characterizations further verify that the catalytic process is compatible with the sonocatalytic mechanism originating from the fracture of surface oxygen-containing groups. Importantly, ec-CDs/ATP with a small mass of CDs loading achieves the same catalytic performance as a large mass of pure CDs. This research innovatively presents a simple synthesis method of a composite CDs sonosensitizer and explores its mechanism of degradation, thus pointing the way to the design of multifunctional sonocatalysts for the degradation of IC in wastewater.

Selective extraction of molybdenum from an industrial powdery tungsten-molybdenum mixture scraps through ultrasonic-assisted electrochemical dissolution mechanism

Extraction and recovery of W and Mo from waste scraps hold significant importance for sustainable resource utilization and environmental protection. Ultrasonic-assisted leaching was demonstrated to be a clean and efficient method for metal dissolution and separation, and the research emphasis of this work was focused on ultrasonic electrochemical behaviors. The HNO3 leaching behaviors of W and Mo under conventional and ultrasonic-assisted processes from powdery W-Mo mixture scraps generated in the powder metallurgy process were investigated. It’s demonstrated that Mo and W can be selectively separated by the regulation of lixiviant concentration and temperature, in which the Mo is converted into the soluble ions (MoO22+) while the W particle is kept in original metallic state and covered with insoluble WO3·H2O. Experiment results indicated that 96.38 % Mo and 8.03 % W were rapidly leached in 2 mol/L HNO3 within ultrasonic-assisted leaching for 10 min at 25 °C, showing a favorable pre-separation effect. Phase transformation and microstructure evolution of the leaching residues under conventional and ultrasonic-assisted leaching processes were analyzed. It’s suggested that Mo can precipitate in the form of molybdenum oxide hydrates, covering the unreacted particle surfaces and further hindering the Mo leaching, especially at higher temperature. This unfavorable situation can be relieved by the introduction of ultrasonic cavitation effect. Importantly, the electrochemical dissolution behaviors of pure W, pure Mo, and W-Mo alloy sheets in HNO3 solution were compared employing the potentiodynamic polarization and electrochemical impedance spectroscopy testing to reveal the ultrasonic intensifying mechanism in this study. Eventually, the ultrasonic electrochemical intensifying mechanism can be referential for the efficient dissolution of metal-based scraps for resource recycling.

Fully Floatable Mortise-and-Tenon Architecture for Synergistically Photo/Sono-Driven Evaporation Desalination and Plastic-Enabled Value-Added Co-Conversion of H2O and CO2.

Establishing an advanced ecosystem incorporating freshwater harvesting, plastic utilization, and clean fuel acquisition is profoundly significant. However, low-efficiency evaporation, single energy utilization, and catalyst leakage severely hinder sustainable development. Herein, a nanofiber-based mortise-and-tenon structural Janus aerogel (MTSJA) is strategically designed in the first attempt and supports Z-scheme catalysts. By harnessing of the upper hydrophilic layer with hydrophilic channels embedding into the hydrophobic bottom layer to achieve tailoring bottom wettability states. MTSJA is capable of a fully-floating function for lower heat loss, water supply, and high-efficiency solar-to-vapor conversion. Benefiting from the ultrasonic cavitation effect and high sensitivity of materials to mechanical forces, this is also the first demonstration of synergistic solar and ultrasound fields to power simultaneous evaporation desalination and waste plastics as reusable substrates generating fuel energy. The system enables persistent desalination with an exceptional evaporation rate of 3.1kgm-2h-1 and 82.3% efficiency (21 wt.% NaCl solution and 1 sun), and realizes H2, CO, and CH4 yields with 16.1, 9.5, and 3 µmolh-1g-1, respectively. This strategy holds great potential for desalination and plastics value-added transformation toward clean energy and carbon neutrality.

Municipal sewage sludge dewatering performance enhancement by ultrasonic cavitation and advanced oxidation: A case study.

The number of published literature on the effect of ultrasonic cavitation and advanced oxidation pretreatment on the dewatering performance of anaerobically digested sludge is very limited. This study aims at determining the optimum operating conditions of large-scale filtering centrifuges in wastewater treatment plants. The optimum dose of hydrogen peroxide, ultrasonic power, ultrasonic duration, ultrasonic pulse and particle size distribution for improved dewatering performance were determined in this study. In addition, shear stress-shear rate and viscosity-shear rate rheograms were developed to show the rheological flow properties for varying ultrasonic power and treatment duration. Optimum sonication power, time, pulse and amplitude were determined to be 14 W, 1 min, 55/5 and 20%, respectively. At a pH of 6.8, the optimum concentration of hydrogen peroxide was found to be 43.5 g/L. The optimum hydrogen peroxide dose in the combined conditioning experiments was determined to be 500 mg/L at a pH of 3. Under these optimum conditions, capillary suction time was reduced significantly by 71.1%. This study helps to reduce polymer consumption and provides the optimum pretreatment and dewatering operating conditions, and better monitoring and control in the dewatering unit has significant impact in the overall economy of wastewater treatment plants.

Mechanism study of aging oil demulsification and dehydration under ultrasonic irradiation

With the tertiary oil recovery in the oilfield, the content of aging oil emulsion with high water content and complex components has become more prevalent, so it is crucial for aging oil to break the emulsification. In this paper, the experimental laws of water content are explored under the conditions of different transducer input powers through the ultrasonic reforming of aging oil, and the microscopic topography, particle size, components, etc. of oil samples before and after the irradiation of ultrasound are characterized through the microscopic analysis, particle size analysis and component analysis and other ways. The results show that the oil samples achieve the effect of demulsification and dehydration in the presence of ultrasonic cavitation effect, with a maximum dehydration rate of 98.24 %, and that the dehydration rate follows an “M−type” trend with the increase of power. The results of microscopic and particle size analyses demonstrate that ultrasonic irradiation destabilizes the oil–water interfacial membrane, and causes droplets of different sizes to collide, agglomerate, and settle. It was also observed that the droplets of the emulsion system are more evenly distributed and the intervals are increased. Furthermore, we hypothesize that ultrasound may be less irreversible in demulsification and dehydration of aging oil.

Studies on the Mechanical, Strengthening Mechanisms and Tribological Characteristics of AA7150-Al2O3 Nano-Metal Matrix Composites

Stir-casting with ultrasonic cavitation produced nano-Al2O3-filled AA7150 matrix composites in this study. The SEM microstructure study shows that all composites include nano-Al2O3 particles with consistent particle sizes and homogenous distribution. EDS and XRD showed no secondary phases or impurities in the composite. Optical microscopy showed intense ultrasonic cavitation effects, and nano-Al2O3 particles caused grain refinement in the AA7150 matrix. The composite’s mechanical characteristics improved when the Al2O3 nanoparticle weight percentage (wt.%) increased. With only 2.0 wt.% nano-Al2O3 particles, the composites yielded 232 MPa, 97.52% higher than the sonicated AA7150 matrix alloy. Multiple models were used to characterize the strength of the AA7150 nano-Al2O3 composite. The findings showed that thermal incongruity, Orowan strengthening, the Hall–Petch mechanism, and load transfer effects contributed the most towards the increased strength of the composite. Increasing the nano-Al2O3 wt.% in the AA7150 matrix improved hardness by 95.08%, yield strength by 90.34%, and sliding wear resistance by 46.52%. This enhancement may be attributed to the combined effects of better grain refinement, enhanced dispersion with dislocation strengthening, and better load transfer between the matrix and reinforcement, which are assisted by the inclusion of reinforcements. This result was confirmed by optical studies.