Study on the efficiency of a transducer for sonochemistry by calorimetry

Sonochemistry is an effective method for initiation or enhancement of the chemical reactions by ultrasound in a wide range of applications. In this study, the efficiency of a sonochemistry transducer, defined as the ratio of ultrasonic power to electrical power, was investigated for different materials and the thicknesses of the vibration plate in the frequency range 22 kHz–2 MHz. The ultrasonic power was measured by calorimetry. To eliminate the influence of reflected waves, the transducer was attached to the side of a cylindrical vessel. The transducer with a stainless-steel vibration plate was more efficient than those with vibration plates of acrylonitrile butadiene styrene plastic or chloroprene rubber. The efficiencies of the transducers also increased with decreasing thickness of the vibration plates. Langevin-type transducers were less efficient than the disk-type transducers.

Optimization of Process Parameters for Enhanced Degradation of Methylene Blue by Trough Ultrasonic

Due to the complex quality and the large discharge of printing and dyeing wastewater, it will pollute the environment and affect human health. Therefore, how to use efficient and inexpensive treatment methods to treat printing and dyeing wastewater has become an urgent problem to be solved. At present, most printing and dyeing wastewater contains methylene blue pollutants. Based on the previous research in this article, the process conditions for the enhanced degradation of methylene blue by trough ultrasound are optimized. Orthogonal test results show that the optimal process parameter for the degradation of methylene blue by trough ultrasonic is pH 12.70, and the initial With a concentration of 10.00mg/L and an ultrasonic power of 200W, under the above optimal process conditions, the degradation rate of methylene blue is 77.95%; Ultrasound improves the rapid degradation of methylene blue through mechanisms such as cavitation, thermal and mechanical effects. This process can be used for the industrial degradation of methylene blue. The application provides a research basis.

Complexation between burdock holocellulose nanocrystals and corn starch: gelatinization properties, microstructure, and digestibility in vitro

Holocellulose nanocrystals (hCNCs), with hydrodynamic diameters (DZ) ranging from about 600 to 200 nm, were prepared by treating burdock insoluble dietary fiber (IDF) with enzymes and ultrasonic power. It was...

Separation of 6-Gingerol in Zingiber Officinale Rubrum Varieties Using an Ultrasonic Assisted Extraction Method

Gingerol is a chemical compound found in red ginger, with pharmaceutical use as an analgesic drug. Generally, gingerol separation in ginger uses the Soxhlet extraction method, but this process has a weakness. It requires a long process and unsatisfactory yield. This research aims to study ultrasonic frequency effect on increasing gingerol yield in the extraction process. The variables studied were extraction times with variations of 30, 60, 90, and 120 minutes. In addition, the ultrasonic effect was also observed with variations in the ultrasonic frequency of 40 and 50 kHz compared to the solvent extraction method. This study used 70% (v/v) ethanol as a solvent and an operating temperature of 50 ºC as fixed variables.Furthermore, it used a rotary vacuum evaporator at a pressure of 350 mmHg to separate the resulting gingerol extract. Qualitative sample analysis used Thin Layer Chromatography (TLC) and scanning electron microscope (SEM) while quantitative analysis used high-performance liquid chromatography (HPLC), Waters Alliance e2695 brand with X-Terra RP18 column 100 x 4.6 mm, five μm to determine the total gingerol extract. The results showed that ultrasonic power had a significant effect on the results obtained, with the highest yield was 24.71% at the ultrasonic frequency of 50 kHz with an extraction time of 120 minutes.

Europium-Doped Y2O3-Coated Diatomite Nanomaterials: Hydrothermal Synthesis, Characterization, Optical Study with Enhanced Photocatalytic Performance

Eu-doped Y2O3 coated diatomite nanostructures with variable Eu3+ contents were synthesized by a facile hydrothermal technique. The products were characterized by means of energy dispersive X-ray photoelectron spectroscopy (EDX), scanning electron microscopy (SEM), powder X-ray diffraction (PXRD), Brunauer–Emmett–Teller (BET), UV-vis diffuse reflectance spectroscopy, and photoluminescence spectroscopy techniques. As claimed by PXRD, the particles were crystallized excellently and attributed to the cubic phase of Y2O3. The influence of substitution of Eu3+ ions into Y2O3 lattice caused a redshift in the absorbance and a decrease in the bandgap of as-prepared coated compounds. The pore volume and BET specific surface area of Eu-doped Y2O3-coated diatomite is greater than uncoated biosilica. The sonophotocata-lytic activities of as-synthesized specimens were evaluated for the degradation of Reactive Blue 19. The effect of various specifications such as ultrasonic power, catalyst amount, and primary dye concentration was explored.

Thermal conduction characteristics of silicone composites including ultrasonic-treated graphite

The microstructural change of graphite was studied after ultrasonic treatment of the graphite. When the graphite solution was treated with varying ultrasonic power and time, the microstructure changed gradually, and accordingly, the thermal conductivity characteristics of the composite containing the as-treated graphite was also different with each other. Thermal conductivity showed the best result in the silicone composite containing graphite prepared under the optimum condition of ultrasonic treatment, and the thermal conductivity of the composite improved proportionally along with the particle size of graphite. When the silicone composite was prepared by using a mixture of inorganic oxides and graphite rather than graphite alone, the thermal conductivity of the silicone composite was further increased. A silicone composite containing graphite was used for LED (light emitting diode) lighting system as a thermal interface material (TIM), and the temperature elevation due to heat generated, while the lighting was actually operated, was analyzed.

Metal Emulsion-Based Synthesis, Characterization, and Properties of Sn-Based Microsphere Phase Change Materials

A comparative study of the metal emulsion-based synthesis of Sn-based materials in two different types of molten salts (namely LiCl–KCl–CsCl and LiNO3-NaNO3-KNO3 eutectics) is presented, and the properties of Sn, Sn-Cu and Sn-Cu-Zn microsphere phase change materials prepared in chloride salts are evaluated by differential scanning calorimetry (DSC) to understand the effect of element doping. Despite a high ultrasonic power (e.g., 600 W or above) being required for dispersing liquid Sn in the chloride system, well-shaped Sn microspheres with a relatively narrow size range, e.g., about 1 to 15 µm or several micrometers to around 30 µm, can be prepared by adjusting the ultrasonic power (840–1080 W), sonication time (5–10 min) and the volume ratio of salts to metal (25:1–200:1). Such a method can be extended to the synthesis of Sn-based alloy microspheres, e.g., Sn-Cu and Sn-Cu-Zn microspheres. In the nitrate system, however, a very low ultrasonic power (e.g., 12 W) can be used to disperse liquid Sn, and the particles obtained are much smaller. At low ultrasonic power (e.g., 12 W), the particle size is generally less than 10 or 4 µm when the sonication time reaches 2 or 5 min, and at high ultrasonic power, it is typically in the range of hundreds of nanometers to 2 µm, regardless of the change in ultrasonic power (480–1080 W), irradiation time (5–10 min), or volume ratio of salts to metal (25:1–1000:1). In addition, the appearance of a SnO phase in the products prepared under different conditions hints at the occurrence of a reaction between Sn droplets and O2 in situ generated by the ultrasound-induced decomposition of nitrates, and such an interfacial reaction is believed to be responsible for these differences observed in two different molten salt systems. A DSC study of Sn, Sn-Cu, and Sn-Cu-Zn microspheres encapsulated in SiO2 reveals that Cu (0.3–0.9 wt.%) or Cu-Zn (0.9 wt.% Cu and 0.6% Zn) doping can raise the onset freezing temperature and thus suppress the undercooling of Sn, but a broad freezing peak observed in these doped microspheres, along with a still much higher undercooling compared to those of reported Sn-Cu or Sn-Cu-Zn solders, suggests the existence of a size effect, and that a low temperature is still needed for totally releasing latent heat. Since the chloride salts can be recycled by means of the evaporation of water and are stable at high temperature, our results indicate that the LiCl–KCl–CsCl salt-based metal emulsion method might also serve as an environmentally friendly method for the synthesis of other metals and their alloy microspheres.

Gradient Cleaning Method of Potato Based on Multi-Step Operation of Dry-Cleaning and Wet Cleaning

In view of the poor effectiveness of existing potato cleaning methods in China and reflecting the findings of a research analysis of basic sizes and types of impurities on potato tubers, a gradient cleaning method for potato based on a multi-step dry-cleaning and wet cleaning operation was proposed. The method mainly consists of dry-cleaning and wet cleaning. The dry-cleaning stage, which combines vibration and brushing, could effectively remove impurities such as residual rhizomes, peeled potato skin, and large pieces of soil and crushed stone from the surface of potato tubers. The wet cleaning stage adopts the gradient cleaning method of pre-cleaning, rough cleaning and fine cleaning, which could further remove soil and crushed stone attached to the surface and hidden in the sprout eyes of potato tubers. The optimal parameter combination for the gradient cleaning method was determined as follows. The potato feeding amount was 3 t/h, the speed of the rubber chain rod mechanism was 25 r/min, the speed of the first and third brush roller was 40 r/min, the speed of the second and fourth brush roller was 56 r/min, the moving speed of the immersion mechanism conveying net chain was 0.04 m/s, the speed of the brush roller in the high pressure spray and brush roller combination mechanism was 40 r/min, the ultrasonic power was 1200 W, the ultrasonic frequency was 33 kHz, the bubble intensity was 300 L/min, and the moving speed of the conveying net chain in the ultrasonic and bubble combination mechanism was 0.05 m/s. Taking the impurity removal rate and damage rate of potato tuber as the test indexes, a potato cleaning performance test was carried out under the optimal parameters combination. The results showed that the average impurity removal rate and damage rate of potato tubers were 99.05% and 2.48%, respectively. Additionally, the operational performance fully met the requirements for potato cleaning. This study provides a new method for potato cleaning in China and can also provide a reference for cleaning other root and tuber crops.

Ultrasonic enhanced water washing method for extracting sodium fluoride from spent pot lining

A large amount of spent pot lining (SPL) is produced by cryolite-alumina melting electrolysis process, and the fluoride content in the leaching solution is up to 6000 mg/L, which belongs to hazardous waste. If SPL is not handled effectively, it will cause great harm to the environment. Because the NaF rich in SPL is an important raw material for the synthesis of cryolite by carbonation, this paper uses SPL as the raw material to extract NaF. On the basis of exploring the process conditions of water washing leaching NaF, ultrasonic wave was introduced to enhance mass transfer and the effects of ultrasonic cavitation on water washing process was compared. The results show that ultrasonic waves can effectively shorten the time for water washing to reach equilibrium and further improve the efficiency of NaF leaching. Under the optimal process conditions determined by the experiment, when the ultrasonic power is 400 W, the time for washing to reach equilibrium is shortened from 50 min to 40 min, and the NaF leaching efficiency is increased from 67.25 % to 70.42 %. While improving the leaching efficiency, the water consumption is effectively reduced, and the purity of the recovered product NaF is 96.82 %. This research provides a technical reference for the harmless and low cost leaching of NaF from SPL in the aluminium electrolysis industry.