Ultrasonic Treatment In Water Research Articles

Degradation of Levofloxacin via Fenton Oxidation Combined with Ultrasonic Treatment in Water

Degradation of Levofloxacin via Fenton Oxidation Combined with Ultrasonic Treatment in Water

Green preparation of graphene oxide nanosheets as adsorbent

As a basic building block of graphene-based materials, graphene oxide (GO) plays an important role in scientific research and industrial applications. At present, numerous methods have been employed to synthesize GO, there are still some issues that need to be solved, thus it is of importance to develop a green, safe and low-cost GO preparation method. Herein, a green, safe and fast method was designed to prepare GO, namely, graphite powder was firstly oxidized in a dilute sulfuric acid solution (H2SO4, 6 mol/L) with hydrogen peroxide (H2O2, 30 wt%) as oxidant, and then exfoliated to GO by ultrasonic treatment in water. In this process, H2O2 was the only oxidant, and no other oxidants were used, thus the explosive nature of GO preparation reaction in the conventional methods could be completely eliminated. This method has other advantages such as green, fast, low-cost and no Mn-based residues. The experimental results confirm that obtained GO with oxygen-containing groups has better adsorption property compared to the graphite powder. As adsorbent, GO can remove methylene blue (50 mg/L) and Cd2+ (56.2 mg/L) from water with removal capacity of 23.8 mg/g and 24.7 mg/g, respectively. It provides a green, fast and low-cost method to prepare GO for some applications such as adsorbent.

The Effect of Ultrasonic Water Treatment on the Change in the Microstructure of Wheat Grain, Dough, and Wheat Flour Bread.

Visualization of the microstructure of the food matrix of both raw materials and the final product is one of the keys to understanding the processes occurring during its formation. It is the fixation of the results at the microlevel that allows us to form a hypothesis and then confirm it with the obtained array of experimental data. The presented study is aimed at studying the effect of ultrasonic water treatment on the change in the microstructure of wheat grain during its humidification. The article also presents the results of studying the microstructure of dough and wheat flour bread obtained using water after ultrasonic water treatment and the intensity of the processes of staling of finished bread in storage. The object of the study was grain of soft spring white wheat (Triticum aestivum L.), varieties of Lubava, harvest 2014-2018, Russia (the protein content was 12.5 ± 0.3 g/100 g in terms of humidity); dough and bread made from wheat flour (ash content 0.55%, mass fraction of gluten 28.5%), produced using the technology of plain bread, a classic recipe without improvers. Ultrasound-treated water with an exposure frequency of 22 ± 1.65 kHz and with a power variation of 252-630 W/l was used in test technology. The experimental data obtained made it possible to establish the intensification of the processes of swelling of wheat grain during soaking. In the experimental samples, after 8 hours of soaking, the loosened structure of the endosperm and evenly swollen components of the grain were observed, and the loop of the groove was closed. Activation of the processes of dough science was established, and gluten flour in the dough formed a single monolithic frame, in which the swollen starch grains are tightly packed. The interstitial walls of the crumb of the prototypes consisted of a solid mass of protein coagulated during baking, inside of which swollen gelatinized starch grains are interspersed, they are closely adjacent to the mass of coagulated protein with their entire surface, and therefore, there is no sharp, clearly visible boundary between them. The most pronounced changes in the structure of the dough and bread crumb were noted when using water, after ultrasonic water treatment at a power of 504 and 630 W/l. This method of exposure can be recommended as the best for obtaining good quality bread with less pronounced staling during storage.

Wet-oxidization and exfoliation of non-swollen MCM-22P to dispersible two-dimensional MWW zeolite nanosheets

Two-dimensional (2D) zeolite nanosheets open exciting opportunities for the application in catalysis and separations. Exfoliation of layered zeolite shows a promising way for the preparation of 2D zeolite nanosheets. Herein, non-swollen MCM-22P with ordered layer spacing was successfully exfoliated to dispersible MWW nanosheets. Firstly, a wet-oxidization method, i.e., heating in a mixture of H 2 SO 4 and H 2 O 2 (called piranha solution) was adopted to remove the template of pyridine (PI) from as-synthesized MCM-22P zeolite. IR, TG, XRD, N 2 adsorption confirmed that the wet-oxidization could efficiently remove PI from MCM-22P zeolite while preserving the MWW crystal structure. Exfoliation of the detemplated MCM-22P zeolite was successfully achieved by an ultrasonic treatment in water. After purification by sedimentation, 2D MWW zeolite nanosheets dispersed in aqueous solution were obtained. The monolayer MWW nanosheets with high purity are confirmed by SEM and TEM observations. The wet oxidation followed by the sonication method provides an alternative way for the exfoliation of layered zeolite to dispersed nanosheets. • Non-swollen MCM-22P was successfully exfoliated to dispersible MWW nanosheets. • Piranha solution was used to eliminate template from MCM-22P. • The template-free MCM-22P was exfoliated by sonication treatment. • Two-dimensional template-free MWW zeolite nanosheets dispersed in solvent were prepared.

Ultrasound regulation of functional properties of Avena sativa L. while sprouting

There has been a significant increase in the oat (Avena sativa. L) consumption recently due to the new scientific data on dietary properties of oats, high content of polyphenols, especially Avenanthramides, and some flavonoids with an antioxidant effect. However, the thick layer of the cell wall in the hypoaleurone area and the uneven distribution of nutrients over the kernel determine the need to find effective technological solutions for their use in food production. The use of whole grain and its sprouting could be one of the possible solutions. Sprouting breaks difficult to digest grain complexes, thus making nutrients available for plant development and easier for human body intake. In the framework of this study, we propose to activate the process of grain sprouting by ultrasonic treatment of water used for preliminary grain soaking. The research results revealed that the proposed method accelerates accumulating of polyphenolic substances, phenolic acids and total antioxidant capacity. The mass fraction of polyphenolic substances in Avena sativa L. samples preliminarily aged in water treated with ultrasound (315W) for 2 minutes was 2.811 mg CAE/g, which is 4.64 times more than the mass fraction of the reference non-sprouted sample. Accumulation of phenolic acids at different treatment modes was intensified by 30.5% and more compared to the non-sprouted grain. Mathematical processing of the total antioxidant capacity (DPPH) results established a reasonable mode of ultrasonic water treatment used for grain soaking - 400 W for 2 minutes, the total antioxidant capacity will be 2.254 mg TEAC / g. Thus, the ultrasonic effect can be recommended as an intensifier in grain sprouting.

Fabrication of Transparent and Microstructured Superhydrophobic Substrates Using Additive Manufacturing.

We report facile one- and two-step processes for the fabrication of transparent ultrahydrophobic surfaces and three-dimensional (3D)-printed superhydrophobic (SH) microstructures, respectively. In the one-step method, polydimethylsiloxane (PDMS) solution is treated thermally at 350 °C for 4 h, while PDMS-soot is generated and deposited on a glass slide to obtain a transparent SH surface without further chemical modification. For the two-step approach, SH surfaces are obtained by incorporating a 3D printing technique with a convenient hydrophobic coating method. Herein, we first 3D-print microstructured substrates with particular surface parameters, which are designed to facilitate a stable gas-trapping Cassie-Baxter (CB) wetting state based on a thermodynamic calculation. We subsequently coat the 3D-printed microstructures with candle soot (CS) or octadecyltrichlorosilane (OTS) solution to make superhydrophobic surfaces with mechanical durability. These surfaces exhibit an ultrahigh static water contact angle (CA, θ ≃ 158 ± 2 and 147 ± 2° for the CS and OTS coating, respectively) and a low roll-off angle for water droplets. Both static and dynamic (in terms of the advancing and receding) contact angles of a water droplet on the fabricated SH surfaces are in good agreement with the theoretical prediction of Cassie-Baxter contact angles. Furthermore, after a one-year-long shelf time, the SH substrates fabricated sustain good superhydrophobicity after ultrasonic water treatment and against several chemical droplets. All of these methods are simple, cost-effective, and highly efficient processes. The processes, design principle, and contact angle measurements presented here are useful for preparing transparent and superhydrophobic surfaces using additive manufacturing, which enables large-scale production and promisingly expands the application scope of utilizing self-cleaning superhydrophobic material.

Theoretical analysis and experimental validation of radial cascaded composite ultrasonic transducer* *Project supported by the National Natural Science Foundation of China (Grant Nos. 11674206 and 11874253).

A radial cascaded composite ultrasonic transducer is analyzed. The transducer consists of three short metal tubes and two radially polarized piezoelectric ceramic short tubes arranged alternately along the radial direction. The short metal tubes and the piezoelectric ceramic short tubes are connected in parallel electrically and in series mechanically, which can multiply the input sound power and sound intensity. Based on the theory of plane stress, the electro-mechanical equivalent circuit of radial vibration of the transducer is derived firstly. The resonance/anti-resonance frequency equation and the expression of the effective electromechanical coupling coefficient are obtained. Excellent electromechanical characteristics are determined by changing the radial geometric dimensions. Two prototypes of the transducers are designed and manufactured to support the analytical theory. It is concluded that the theoretical resonance/anti-resonance frequencies are consistent with the numerical and experimental results. When R 2 is at certain values, both the anti-resonance frequency and effective electromechanical coupling coefficient corresponding to the second mode have maximal values. The radial cascaded composite ultrasonic transducer is expected to be used in the fields of ultrasonic water treatment and underwater acoustics.

The role of co 2 in improving sonic hydrogen production

The role of co ₂ in improving sonic hydrogen production

The ultrasonication boosts the surface properties of CoFe2O4/C nanoparticles towards ORR in alkaline media

Since ultrasonication was reported to be used for exfoliation of layered materials in water (Science-ref. 31), the method has never been explored in non-layered materials, in particular, the effect of ultrasonication on the surface property of materials. In this work, CoFe2O4/C nanoparticles were synthesized and processed using ultrasonic treatment in water. Through the ultrasonic treatment, the electrocatalytic activity of the CoFe2O4/C nanoparticles towards ORR was improved significantly with a higher mass activity (5.05 mA mg−1) than the original CoFe2O4/C (2.75 mA mg−1) in O2-saturated 0.1 M KOH solution. The half-wave potential on the original CoFe2O4/C was also shifted to the positive side by 60 mV. Furthermore, the treated CoFe2O4/C catalyst exhibits a constant half-wave potential with better onset potential after 2000 cycles, and a 50 mV of half-wave potential on the original catalyst was moved to negative under same test condition. The analysis from characterizations reveals that the enhanced ORR performance of the treated CoFe2O4/C resulted from the Co2+ and Fe3+ enriched surface with more cations being occupied in the tetrahedral sites than the octahedral sites after ultrasonic treatment. In addition, compared to the original CoFe2O4/C catalyst, the specific surface area of the treated CoFe2O4/C was improved 1.8 times, mesoporous grown to microspores with 2.2 times increased volumes, which has provided higher active sites and accelerated transport between O2 and electrolyte during the ORR process. The ORR via the 4-electron transfer pathway on the treated CoFe2O4/C catalyst, while the 2-electron transfer process is favoured on the original CoFe2O4/C catalyst. This further signifies that the ultrasonic process had significantly influence on the electrochemical properties of the CoFe2O4/C catalyst.

Development and validation of an HPLC-DAD-MS method for determination of four nucleoside compounds in the New Zealand native mushroom Hericium sp.

To identify and quantify the content of nucleoside compounds in the New Zealand native edible mushroom Hericium sp., a high-performance liquid chromatography coupled with a triple quadrupole detector mass method was developed and validated. Four nucleoside substitutes, namely cytidine, uridine, adenosine, and guanosine, were identified. Optimization was conducted to study the effect of extraction method type, solvent pH, and extraction time. The optimal conditions were obtained using ultrasonic treatment in water at pH 3.8 for 30 min. For chromatographic separation, a C18 column was applied using 0.1% formic acid (pH 3.4) as the mobile phase with detection at 260 nm. The total concentration of the four nucleoside compounds was high, at 10.7 mg/g dry weight, indicating a potential benefit for human health. The excellent validation results based on selectivity, linearity, precision, accuracy and robustness revealed the reliability of the newly developed analytical method, which could be applied routinely in research laboratories.

Mechanical, pH and Thermal Stability of Mesoporous Hydroxyapatite

The stability of mesoporous hydroxyapatite (HAP) powder was studied following treatments of ultrasound, pH and heating. HAP was found to be mechanically stable up to (and including) 1 h continuous ultrasonic treatment in water. The HAP structure was also stable to pH, evidenced by practically identical XRD and FTIR spectra over the pH range 2–12. The surface area increased progressively with increasing acidity, reaching a maximum of 121.9 m2 g−1 at pH 2, while alkaline conditions decreased the surface area to a minimum of 55.4 m2 g−1 at pH 12. Heating in air had a significant influence on the structural and morphological properties of HAP, which underwent dehydroxylation to form oxyhydroxyapatite (OHAP) at temperatures ≥ 650 °C, and β-tricalcium phosphate (β-TCP) ≥750 °C. The surface area decreased at elevated temperatures due to agglomeration of HAP crystals by sintering, which was associated with an increased particle size.

Actual aspects of quality raw materials in the production of beverage technology

The relevance of the topic lies in the task of providing the beverage industry with high quality feedstock. In the brewing industry there is the problem of water quality. To solve this problem is possible by implementation of modern achievements of science and technology ( ultrasonic water treatment in the stage production of malt in the process of soaking and germination of malting barley.In this regard, we have justified the use of targeted ultrasonic treatment of water at the stage of malt production in the process of soaking and germinating barley intended for obtaining a beverage such as beer. As a result of our studies, we have established a positive effect of ultrasound on water quality when certain conditions are created. Such conditions are the parameters of ultrasound exposure: power and processing exposure. We have revealed regularities associated with the mechanism of ultrasound action on water quality; The optimal valuesof the parameters of ultrasonic action are determined, which allow obtaining a given level of quality of water due to the achievement of certain values of such parameters as rigidity, pH and total microbial number. The positive influence of ultrasonic treatment on the quality and properties of water under certain conditions; the regularities and the effective parameters of this impact. We used ultrasonic device (UZTA O OM 4/22). Water treatment at a frequency of 22 kHz, a power of 180-240 W, 3-5 minutes exposure achieves positive effects on quality metrics such as: rigidity, which is reduced by 14-22% of the initial value; pH, which decreases to 0.28-0.35 units; total bacterial number, which is reduced by 6-7 times.

The Effect of Ultrasonic Extraction of Soluble Sugars from the Wood Filler on the Strength Properties of the Composite Based on Mineral Binder

One of the main problems of wood as filler in the production of composite materials based on mineral binder is "cement poisons". Article presents the results of research of the processes of "cement poisons" removal from wood raw material for the production of cement-bonded particleboards. In the research process the treatment of wood raw material was carried out in two ways: by boiling of the crushed wood and by ultrasonic treatment in water. It has been found that ultrasonic treatment significantly intensifies and increases the extraction of water-soluble sugars and, thus, causes an increase of the strength characteristics of cement-bonded particleboards. The conducted research shows the possibility of improvement of the technology of production of cement-bonded particleboards with the aim of improving their performance without significant capital investment.

Electrically robust silver nanowire patterns transferrable onto various substrates.

We report a facile technique for patterning and transferring silver nanowires (AgNWs) onto various substrates. By employing only UV/O3 and vapor treatment of hexamethyldisilazane (HMDS), we are able to accurately manipulate the surface energy via alternating the terminal groups of a polydimethylsiloxane (PDMS) substrate, so as to assist selective formation and exfoliation of AgNW films. A simple UV/O3 treatment on PDMS enables uniform, well-defined, and highly conductive patterns of AgNWs after spin-coating. A vapor treatment of HMDS lowers the surface energy of the oxidized PDMS so that the patterned AgNWs embedded in an epoxy resin (EPR) are cleanly transferred from the PDMS to the target substrate. It is found that the AgNW-EPR composite on polyethylene glycol terephthalate (PET) exhibits remarkable durability under the bending test, tape test, ultrasonic treatment in water, and immersion of chemical solvents. In addition, we demonstrate that the AgNW-EPR composite work well as conductive patterns on the oxidized PDMS, polyvinyl alcohol (PVA), paper, and curved glass. The facile technique extends the applicability of AgNWs in the field of electronics, and it is potentially applicable to other nanomaterials.

ПРОЛОНГИРОВАНИЕ СРОКОВ ХРАНЕНИЯ ПОЛУФАБРИКАТОВ ИЗ МЯСА ПТИЦЫ НА ОСНОВЕ МЕТОДОВ СОНОХИМИИ

Modern consumers are giving preference to prefabricated meat fully prepared for thermal treatment. In its turn production of this type of goods requires optimal technological decisions for safety provision and the required storage life. The paper deals with the effect of ultrasonic exposure on the storage stability of prefabricated meat products. The main study subjects were natural prefabricated broiler chicken meat (“Chicken leg quarter”, “Chicken breast”) and chopped half-finished products in a chilled state like “Nuggets”, obtained according to standard technologies (injected by pickle with antioxidants) and modified technologies (with pickle on the basis of ultrasonic treatment). The dynamics of hydrolytic and oxidizing process behavior in case of ultrasonic treatment in the technology of prefabricated broiler chicken meat is considered. The organoleptic quality control is performed. The relative stability of experimental samples relative to check ones is established. It's shown that the change of physical and chemical indicators (the content of volatile fatty acids, amine nitrogen) happens with a moderate intensity. The positive dynamics is also observed in the reduction of QMAFAnM indicator. In the course of studies on the ultrasound effect on aqueous solutions it's found out that as a result of ultrasonic water treatment reactive oxygen species are formed due to the presence of Fenton's reagent that may result in oxidation of essential substances, primarily fats with the formation of hydroperoxides. During the examination of a lipid fraction of broiler chicken prefabricated meat produced on the basis of ultrasonic exposure, peroxide compounds have not been found, which indicates the optimality of chosen modes of ultrasonic exposure. The selected modes of ultrasonic pickle treatment enabled one to optimally ensure a lethal threshold of sound field characteristics to stop the development of unfavorable microflora in prefabricated meat products, which undoubtedly has a positive effect on their consumer properties.

Removal of the off-flavor compounds geosmin and 2-methylisoborneol from recirculating aquaculture system water by ultrasonically induced cavitation

With its high economic impact, off-flavor in fish is still one of the most serious problems in the aquaculture industry worldwide. Until now, the highly cost- and time-intensive, as well as capacity demanding depuration procedure by moving the fish to clean and odor-free water for a certain time prior to harvest is the only reliable way to counteract off-flavors in aquaculture. Alternative strategies and processes for efficient off-flavor prevention are still lacking. Hence, the aim of this study was to investigate the potential of ultrasonic water treatment to decrease the concentration of the relevant off-flavor compounds geosmin (GSM) and 2-methylisoborneol (2-MIB) in aquaculture water. Therefore, different water matrices, varying in their organic and inorganic load and composition (tap water, RAS fresh water, RAS sea water), were spiked with 2-MIB and GSM standard and subsamples of 250mL were subsequently treated for 15min using a lab-scale ultrasound transducer at 850kHz. For verification samples from commercial RAS containing biogenic 2-MIB and GSM were treated equally. The effects of ultrasound frequency and salinity on the removability of 2-MIB and GSM via ultrasonic treatment were investigated by comparing the removal efficiency of high (850kHz) vs. low (20kHz) frequency ultrasound and by adding artificial sea salt (10ppt) to different freshwater samples prior to ultrasound treatment, respectively.Results have demonstrated that ultrasonically induced cavitation significantly reduces the tested off-flavor compounds GSM and 2-MIB in all tested water types, seemingly irrespective of the (in)organic load. In general, the reduction of GSM was slightly higher compared to that of 2-MIB. Furthermore, the reduction of tested off-flavor compounds was significantly enhanced at high frequency ultrasound (850kHz) compared to low-frequency ultrasound (20kHz). The addition of artificial sea salt to fresh water samples caused an additional improvement in removability of both off-flavor compounds.Our results evidence high frequency ultrasound as a potential treatment process for significant removal of the relevant off-flavor compounds 2-MIB and GSM from RAS process water. In particular, the seemingly low dependency of the ultrasound-induced removal of GSM and 2-MIB on the organic and inorganic process water load predestines ultrasonically induced cavitation as a potential strategy for off-flavor prevention in RAS compared to alternative strategies such as advanced oxidation processes or adsorption processes.

Certain characteristics of composite polytetrafluoroethylene-oxide coatings on aluminum alloy

We present the results of an investigation of the distribution of of elements according to cross-section morphology, adhesion, and anticorrosive properties of PTFE-oxide layers formed by plasma-electrolytic oxidation in an Na2SiO3 + NaOH electrolyte with dispersive particles of PTFE stabilized by siloxane acrylate emulsion. Coatings have a structure uncharacteristic of PEO layers. The main coating mass of thickness of up to 80 μm is composed of polytetrafluoroethylene and decomposition products of PTFE particles, as well as of the emulsion. The transition layer between the metal and polymer coating has a thickness of ∼10 μm and contains oxides of aluminum and silicon. Sample weight loss after ultrasonic treatment in water is ∼1%, which indicates a satisfactory adhesion of the coating to the metal and the cohesion between coating fragments. The coatings have a complex surface with pores several tens of microns in size. After annealing in air at 200°C, pores are filled with polymer, which is accompanied by a significant improvement in the coating’s anticorrosive properties. As a result of annealing in air at 400°C, the polymer coating sublimates and the transition layer with a thickness of ∼10–15 μm remains.

Site-Selective Growth of Patterned Silver Grid Networks as Flexible Transparent Conductive Film by Using Poly(dopamine) at Room Temperature

Metal transparent conductive films (TCFs) have received increasing attention in various flexible electronics. However, there are two crucial issues that need to be addressed: (1) strong adhesion between metal TCFs and the flexible substrates and (2) high conductivity with short treatment time and low process temperature, simultaneous with high transparency. In this paper, a site-selective electroless plating combination with poly(dopamine) modification is demonstrated to fabricate a new high performance transparent conductor composed of a periodic two-dimensional silver network on a heat sensitive flexible substrate at room temperature. The TCF reveals an extremely high ratio of DC to optical conductivity (σ(DC)/σ(Op)) value in the range of 350-1000 for various fabricated silver grid films. It also exhibits particularly strong adhesion, which can resist ultrasonic treatment in water or organic solvent for several hours. Its reliability (stable for at least 1440 h during 85 °C/85% RH aging) meets the essential requirements for microelectronic applications. Using this method, we obtain silver grid film on a flexible polyethylene terephthalate substrate with optical transmittance of 91% and sheet resistance of 8 Ohm sq(-1), which is comparable to or better than the commercially available indium tin oxide.

Critical role of surface chemical modifications induced by length shortening on multi-walled carbon nanotubes-induced toxicity

Given the increasing use of carbon nanotubes (CNT) in composite materials and their possible expansion to new areas such as nanomedicine which will both lead to higher human exposure, a better understanding of their potential to cause adverse effects on human health is needed. Like other nanomaterials, the biological reactivity and toxicity of CNT were shown to depend on various physicochemical characteristics, and length has been suggested to play a critical role. We therefore designed a comprehensive study that aimed at comparing the effects on murine macrophages of two samples of multi-walled CNT (MWCNT) specifically synthesized following a similar production process (aerosol-assisted CVD), and used a soft ultrasonic treatment in water to modify the length of one of them. We showed that modification of the length of MWCNT leads, unavoidably, to accompanying structural (i.e. defects) and chemical (i.e. oxidation) modifications that affect both surface and residual catalyst iron nanoparticle content of CNT. The biological response of murine macrophages to the two different MWCNT samples was evaluated in terms of cell viability, pro-inflammatory cytokines secretion and oxidative stress. We showed that structural defects and oxidation both induced by the length reduction process are at least as responsible as the length reduction itself for the enhanced pro-inflammatory and pro-oxidative response observed with short (oxidized) compared to long (pristine) MWCNT. In conclusion, our results stress that surface properties should be considered, alongside the length, as essential parameters in CNT-induced inflammation, especially when dealing with a safe design of CNT, for application in nanomedicine for example.

Graphene Layers from Reduction of Exfoliated Graphite Oxide

Graphene oxide (GO) of approximately 1 nm was generated from exfoliated graphitic oxide using a modified Hummers method through ultrasonic treatment in water, and the GO film was reduced under protection of Ar/H2 flow at 800 degrees C. Moreover, the obtained graphene film has a high conductivity of 383 S/cm at 10-20 nm thickness.