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Acoustic droplet ejection (ADE) has been proven to move liquids in droplet form from a container to mid-air. However, the droplet sizes produced using the traditional ADE setups are proportional to their heights if the physical framework is unchanged. This limitation obstructs further employment of ADE technology since having the exact sizes of droplets at a specific location or different sizes at different locations is required for many applications. To overcome this limitation and enable more possible applications of ADE, this study proposed an innovative ADE configuration that could manipulate the size and height of the ADE droplets with only electrical signals. To achieve this, a low-voltage driving period and a pinhole structure were added to create a water mound before ejection. First, simulations were conducted to validate the proposed method and find the parameters of the novel ADE setup. After that, a driving circuit featuring a high-voltage pulser and a field-programmable gate array was built. However, a 3D spherical resin model was printed to focus the acoustic wave on the water surface, and a cover with a pinhole was added to create water mound. To observe the behavior of the droplets, a recording system and detection algorithm were developed to capture and identify the dimension/height of the droplets, respectively. Finally, the proposed ADE configuration successfully manipulated the droplet size at the same ejecting height under three driving voltages (65, 70, and 75 V) and pinhole diameters (3.7, 4, and 4.4 mm). [ABSTRACT FROM AUTHOR]

Cellulose nanocrystals (CNC) have received much attention as a drug delivery vehicle, but their hydrophilic nature hinders hydrophobic drug loading. Ionotropic gelation using CNC and chitosan (CS) can enhance the loading/encapsulation capacity of hydrophobic compounds, improve colloidal stability, and strengthen mucoadhesion due to the cationic surface of CS. The colloidal behavior of CNC/CS nanocomposites loaded with emamectin benzoate (EMB) were elucidated by measuring the particle size, zeta potential, contact angle, and morphological structure using transmission electron microscopy. The mucoadhesive properties of the nanocomposites were evaluated by viscometric and titration method, followed by testing with zebrafish mucus. A facile and reproducible protocol to synthesize mucoadhesive CNC/CS nanocomposites that can encapsulate hydrophobic drugs is demonstrated. The optimal mass ratio for the synthesis was 1:10 (CS:CNC w/w), yielding the smallest average particle size (∼200 nm), highest zeta potentials (+40 mV), and highest drug encapsulation capacity (68.8 ± 8.7%). The steric stabilization effect of polyvinylpyrrolidone (PVP) and amphiphilic CNC stabilized the colloidal system. Importantly, the CS-coating technique enhanced the colloidal stability due to electrostatic intramolecular repulsion of the positive CS. CNC/CS nanocomposites exhibited enhanced mucoadhesive interaction with porcine mucin protein and live zebrafish mucus.

There might be a three-layer molten pool configuration with a heavy metallic layer at the bottom in the stratified molten pool configuration. Because of the decay heat in the heavy metallic layer and the relatively low critical heat flux (CHF) at the bottom of the molten pool, vessel failure could occur at the sidewall adjacent to the heavy metallic layer. The heavy metallic layer experiment was carried out using Wood’s metal or water as the simulant to analyze the heat transfer of the heavy metallic layer under different boundary conditions. The experimental apparatus mainly contains the cooling water tank, pump, valve, test section, and watercooling heat exchanger. The different cooling rates could be obtained by adjusting the valves. Wood’s metal test has a top cooling and a sidewall cooling boundary conditions, and water tests have a top heated and a sidewall cooling boundary conditions. The sidewall cooling channels were used to simulate the external reactor vessel cooling (ERVC) conditions. A three-dimension hemisphere with a radius of 1.2 m was used as the test section, and the heavy metallic layer’s height was set to 0.3 m. Heating coils were installed in the test section to simulate the decay heat in the heavy metallic layer. Besides, thermocouples were inserted in the sidewall and test section to record the temperature data. The experimental results illustrate that the melt temperature in the heavy metallic layer increases with the height. Thermal stratification is evident in the heavy metallic layer, and heat convection is limited. But the normalized melt temperature along the horizontal direction tends to be constant. When no crust formation occurs, the water test results demonstrate that the sideward heat flux increases with the polar angle. However, when the crust formation occurs in the heavy metallic layer, Wood’s metal test results demonstrate that the dominant heat transfer mode would turn from the convective heat transfer to the heat conduction. It will affect the sideward heat flux distribution that is not constant for both heat transfer modes. Consequently, the sideward heat flux would decrease with the increase of the polar angle and the maximum sideward heat flux occurs in the bottom of the test section. By comparing the experimental sideward Nusselt number with the calculated results of previous correlations, it is found that the heat transfer correlations of ACOPO, BALI, Mayinger, and UCLA could reasonably predict the average sideward Nusselt number of the heavy metallic layer when Wood’s metal or water is the simulant.

In this work, (Bi0.5Na0.5)0.94Ba0.06TiO3 (BN6BT) lead‐free ceramics were prepared via cold‐sintering followed by annealing, and effects of grain size of precursor powders and annealing temperature on microstructure, dielectric, and ferroelectric properties of the ceramics were studied. The precursor powders for cold sintering were obtained by mixing the powders with sub‐micrometer (average grain size, AGS = 0.26 μm) and nanometer (AGS = 73 nm) grains in various mass ratios (1:0, 1:1, 1:2, and 1:4). The precursor powders were mixed with deionized water and cold sintered at 180°C for 1 h under 500 MPa. The cold‐sintered samples were then annealed at temperatures between 800 and 1000°C for 2 h. For the ratios of 1:2 and 1:4, the corresponding ceramics annealed at 950°C exhibit dielectric and ferroelectric properties similar to those of the BN6BT ceramics sintered at 1170°C via the solid‐state sintering method. The present BN6BT ceramics exhibit dense microstructure with finer grains with AGS = 280 nm, higher breakdown strength (BDS = 160 kV· cm−1) compared to the solid‐state sintered BN6BT ceramics with AGS = 1.6 μm and BDS = 75 kV· cm−1. The results demonstrate that the cold‐sintering followed by annealing is effective in preparing BN6BT ceramics with fine grains and excellent dielectric and ferroelectric properties at relatively low temperatures. [ABSTRACT FROM AUTHOR]

Isaria cicadae is an entomogenous fungus that has been used as a traditional Chinese medicinal materials to treat different diseases, including cancer. However, Isaria cicadae conidia for inhibitory activity against breast cancer cells growth are still not systematically studied. The present aim was to elucidate the phytochemical composition of Isaria cicadae conidia and to explore relevant anti-cancer potential in gynaecological carcinoma MCF-7 and Hela cells. Isaria cicadae conidia were identified by UPLC-ESI-Q-TOF-MS: high performance liquid chromatography-electrospray/quadrupole time of flight tandem mass spectrometry technology. Eight main compounds were identified which are nucleosides, cordycepic acid, cordycepin, beauvericin and myriocin by MS fragmentation ions. The nuclear morphology indicated the typical characteristics of apoptosis by Hoechst staining. Annexin V/PI staining revealed that the number of apoptotic cells was increased by Isaria cicadae conidia treatment. Furthermore, Isaria cicadae conidia also induced the caspase-mediated mitochondrial apoptosis pathway. The findings suggest that the full-scale active ingredients highlight the significance of Isaria cicadae conidia as potential anti-cancer agent in China.

Food-derived oligosaccharides show promising therapeutic potential in lowering blood pressure (BP), but the mechanism is poorly understood. Recently, the potential role of gut microbiota (GM) in hypertension has been investigated, but the specific GM signature that may participate in hypertension remains unclear. To test the potassium alginate oligosaccharides (PAO) mechanism in lowering BP and specific microbial signature changes in altering GM, we administered various dosages of PAO in 40 spontaneously hypertensive rats for a duration of six weeks. We analyzed BP, sequenced the 16S ribosomal DNA gene in the cecum content, and gathered RNA-seq data in cardiac tissues. We showed that the oral administration of PAO could significantly decrease systolic BP and mean arterial pressure. Transcriptome analyses demonstrated that the protective effects of developing heart failure were accompanied by down-regulating of the Natriuretic Peptide A gene expression and by decreasing the concentrations of angiotensin II and atrial natriuretic peptide in plasma. In comparison to the Vehicle control, PAO could increase the microbial diversity by altering the composition of GM. PAO could also decrease the ratio of Firmicutes to Bacteroidetes by decreasing the abundance of Prevotella and Phascolarctobacterium bacteria. The favorable effect of PAO may be added to the positive influence of the abundance of major metabolites produced by Gram-negative bacteria in GM. We suggest that PAO caused changes in GM, and thus, they played an important role in preventing the development of cardiovascular disease.

Dense K0.5Na0.5NbO3 lead‐free ceramics were successfully fabricated by combining cold sintering process (CSP) with annealing in air atmosphere or low pO2 atmosphere. Acetic acid was used as transition liquid. By optimizing the liquid content and pressure during CSP, the CSP samples with relative densities 74.2% were obtained with adding 15 wt% acetic acid under 800 MPa. The CSP samples were then annealed in air atmosphere between 1000 and 1100°C. The ceramics annealed at 1050°C exhibit excellent electrical properties with piezoelectric constant d33 = 125 pC/N, dielectric constant εr = 509, dielectric loss tan δ = 0.04, and remanent polarization Pr = 38.17 μC/cm2. Additionally, the mixture of K0.5Na0.5NbO3 and base metal Ni powders was also cold‐sintered and then annealed in the low pO2 atmospheres in order to detect whether Ni was oxidized or not. The optimized low pO2 atmospheres to protect the Ni from oxidation are pO2 = 10−10 atm followed by reoxidizing in pO2 = 10−6 atm. The K0.5Na0.5NbO3 fabricated by CSP with annealing in the optimized low pO2 atmospheres exhibits comparable electrical properties of the ceramics annealed in air atmosphere, providing an optional approach for using base metals as electrodes. [ABSTRACT FROM AUTHOR]

In view of problems of energy waste and environmental pollution caused by high power consumption and low efficiency of existing motors, a mine-used flameproof three-phase asynchronous motor with high voltage and high efficiency was developed. Development goals, selection of slot matching of stator and rotator, determination of punch size of stator and rotator, main parameters design in electromagnetic calculation, and structure design of the motor were introduced detailedly. Prototype test results show that test values of efficiency of the developed motor are more than the value of energy efficiency grade of 1evel 1 in GB 30254-2013 High Voltage Three-phase Cage Asynchronous Motor Energy Efficiency Limit and Energy Efficiency Level, and at the same time, it can meet design requirements of low noise and low vibration.

Light control of dielectric properties is very significant to develop photo-dielectric devices. Here, light-triggered "on-off" switchable dielectric constant (εr) was observed in (Bi0.5Na0.5)0.94Ba0.06TiO3 lead-free ferroelectric ceramics, exhibiting unconventional photo-dielectric effect (PDE). The effects of light switch period (2–165 min), light intensity (20–100 mW/cm2), and wavelength (450–940 nm) on PDE were studied in detail. Variation in εr exhibits remarkable switch effect with changing light on-off, while dielectric loss remains almost unchanged, and conductivity is still as low as 10−12 S/cm with excellent electrical insulation under light irradiation. The unconventional PDE exists in the high-frequency range ≥1 MHz and at the low-temperature of −100 °C. In addition to the thermal effect and light-induced change in domain behavior, it is believed that polarization of the trapped electron-hole pairs under an external electric field contributes to the increase in εr, and the low mobility of the pairs contributes to low dielectric loss and low photoconductivity. The results exhibit that dielectric constant of the lead-free ceramics can be regulated via light, whilst the ceramics keep excellent electrical insulation, endowing the lead-free ceramics potential applications in photo-dielectric devices. [ABSTRACT FROM AUTHOR]

Through in-situ reduction method, Ag nanoparticles were loaded on the surfaces of EVA composite foams. A series of investigations, including field emission scanning electron microscopy, X-ray photoelectron spectroscopy and X-ray diffraction, were carried out to characterize the samples. Thermal stability and antibacterial properties of the products were evaluated by thermo gravimetric analysis and antibacterial test, respectively. Results show that nanoparticles, with an average particle size of 20nm, are elemental silver and decorated on the surface of EVA composite foams in uniform and regular stacks; after the presence of Ag nanoparticles, char yield of the products at 600℃ could increase to 3.22%; the samples have good persistent antibacterial effects and after 50 washing cycles, the antibacterial rate reaches above 98% and 99% against escherichia coli and staphylococcus aureus, respectively.