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Electrostatic spraying (ES) can improve the machining and environmental effects of minimum quantity lubrication (MQL). Compared with ES, composite electrostatic spraying (CES) presents better results because of excellent charging and cooling/lubrication performances. This article investigated the performance of CES milling using different inner/outer fluid combinations in terms of milling force, tool wear and oil mist concentration. Four inner/outer fluid combinations were employed in the study, namely, water/LB2000, multiwalled carbon nanotubes (MWCNTs)-water nanofluid/LB2000, water/MWCNTs-LB2000 nanofluid and MWCNTs-water nanofluid/MWCNTs-LB2000 nanofluid. For the analysis of the performance of CES milling, the charging property and atomization stability of CES and the electrowetting performance of composite droplet were measured. The results show that MWCNTs-water nanofluid/LB2000 was the optimal inner/outer fluid combination for CES milling from the view point of machining and environmental performances because of superior charging property, atomization stability and friction-reducing effect of nanoparticles. The performance of CES milling using different inner/outer fluid combinations was studied in terms of milling force, tool wear and oil mist concentration. The charging property and atomization stability of CES and the electrowetting performance of composite droplet were measured. MWCNTs-water nanofluid/LB2000 was the optimal inner/outer fluid combination for CES milling. [ABSTRACT FROM AUTHOR]

• Si-based bioactive glass coatings fabricated by coupling sol-gel and electrospray. • Compositional optimization of S85, S75, and S58 coatings on Ti6Al4V substrate. • Microstructural tunning of homogeneous BG coatings as a function of ESD parameters. • From very porous coral-type coating morphology to a more compacted cauliflower one. • In-vitro investigation after 24 h immersion in simulated body fluid. For the first time, the sol-gel method was coupled with electrostatic spray deposition (ESD) to fabricate nanotextured bioactive glass (BG) coatings with a controlled microstructure in a one-pot-process. Three BG compositions belonging to the SiO 2 -CaO-P 2 O 5 system (S85, S75, and S58) were homogeneously deposited on metallic Ti6Al4V substrates starting from the atomization of precursor solutions. All coatings displayed an amorphous character, as confirmed by XRD. A wide variety of innovative BG morphologies were obtained, tuning the key parameters of ESD, leading from highly porous coral-like to compact reticular-type coatings. The bioactivity, in terms of apatite formation, of as-deposited coatings was tested by immersion in simulated body fluid solution. Textural properties were found to play an important impact in its biological performance. Highly porous ESD-coatings exhibited remarkable bioactivity for S75 and S58 compositions, compared with more compacted ones of equal formulations. S85 composition was found extremely reactive regardless of the coating microstructure. [ABSTRACT FROM AUTHOR]

Composite electrostatic spraying (CES) is a process in which the coaxial jet generates when the inner and outer fluids flowing through the coaxial nozzle are charged, and jet end is broken into charged composite droplets. This paper experimentally investigated the effects of types of inner and outer fluids, voltages, and flow rates of inner and outer fluids on cutting force and cutting temperature in CES milling of aluminum alloy. The inner fluid used included water and multi-walled carbon nanotubes (MWCNTs)-water nanofluid. The outer fluid used involved castor oil, sunflower oil, MWCNTs-castor oil nanofluid, and MWCNTs-sunflower oil nanofluid. The atomization mode, current, and droplet velocity of CES were measured under different types of inner and outer fluids, voltages, and flow rates of inner and outer fluids. Results show that from the viewpoint of reducing cutting force and temperature, MWCNTs-sunflower oil nanofluid/MWCNTs-water nanofluid and 5 ml/h were the optimal outer/inner fluid combination and flow rate due to excellent charging performance, high droplet velocity, and superior friction-reducing effects of sunflower oil and MWCNTs. [ABSTRACT FROM AUTHOR]

In the present study, Blast Furnace Slag (BFS) waste was evaluated as a sustainable, cost-effective CaO, SiO 2 , Al 2 O 3 and MgO substitute for inorganic oxides for the production of frit, a raw material for glass ceramic production. Two different frits were prepared to compare a commercially available frit (F-STD) with frit produced using BFS waste (F-BFS). The samples were characterized by XRF, XRD, heating microscopy, dilatometry and TG-DTA to determine the chemical composition, phase formation and thermal properties. The frits were applied on steel using the electrostatic spray method and subsequently thermally treated at 830 °C for 4.5 min. The reference (GC-STD) and partially BFS-substituted glass ceramic (GC-BFS) coatings were examined by XRD, SEM-EDS and ICP-MS experiments. The main crystal phase for both samples was Ni-substituted fluorine mica (KLiNi 2 Si 4 O 10 F 2). GC-BFS was slightly more amorphous (70%) than GC-STD (69.1%), which was correlated with the thermal properties of the BFS waste. Likewise, ICP-MS analysis after a boiling citric acid test (ISO 28706-1: 2008) revealed that the GC-BFS had relatively higher chemical resistance. The total release from the reference sample (GC-STD) was 23.556 mg/L, whereas the total release from the sustainably produced sample (GC-BFS) was 21.451 mg/L, which was consistent with the XRD results. [ABSTRACT FROM AUTHOR]

As a simplistic concept, needle electrodes to generate atomization in the liquid phase were increased for forming multiple Taylor cones. Numerical simulations using a Poisson equation were performed to optimize the distance between the needle electrodes. The simulation results revealed that the distance between the needle electrodes affected the formation of the Taylor cone, and that the stabilization of the Taylor cone required a distance of over 30 mm between electrodes. The experimental results similarly showed the stabilization of Taylor cones by a distance of 30 mm between electrodes. Multiple Taylor cones stabilized via electrostatic atomization were applied to produce encapsulated oil powders. The increase in the number of electrodes enabled the mass production of encapsulated oil powders via nozzleless electrostatic atomization. This technology may allow the formation of oil powders with functional particles. Practical Applications: Electrostatic atomization in the liquid phase is an attractive process for obtaining spherical particles; however, this technique affords a low level of production of the generated particles. The present study aimed to develop a device for the mass production of encapsulated oil powders using nozzleless electrostatic atomization. Numerical simulations were used to design the device for electrostatic atomization for mass production. Multiple Taylor cones may allow the mass production of encapsulated oil powders. [ABSTRACT FROM AUTHOR]

The surface properties of thermally modified ash wood with a powder coating were investigated, and the results were compared to the unmodified wood. The wood specimens were sanded with 80 grit sandpaper and then pre-heated at 80 °C for 5 min in an infrared oven. The surface of the unmodified and the modified wood specimens were coated with an epoxy/polyester (1 to 1 ratio) hybrid coating using an electrostatic corona spray gun at the pilot plant established in the laboratory. The coatings on the wood specimens were cured at different curing conditions in an infrared oven, i.e., 120 °C/15 min, 140 °C/10 min, and 160 °C/10 min. The results showed that the thermal modification (TM) of the wood caused a slight decrease in the mechanical performance of the surface system (wood substrate and coating film). For example, the scratch and abrasion resistance of the unmodified specimens at the curing temperature of 120 °C were 3.33 N and 135 revolutions but were 3.12 N and 120 revolutions after the TM. However, the average surface roughness (1.26 mu) and contact angle (60.8°) of the distilled water on the cured coatings on the modified wood were lower than those on the unmodified wood (1.86 mu and 80.8°, respectively). [ABSTRACT FROM AUTHOR]

With the gradual deterioration of the ecological environment and the increase in requirements for the quality of modern life, the use of pesticides is bound to develop towards higher pesticide utilization and less environmental pollution, and the low-volume spraying for agricultural aviation operation combined with the Drift Reducing Technologies (DRTs) may be a useful way to achieve this goal. Based on an analysis of the spray drift mechanism and the primary factors influencing aerial spraying, previous research on DRTs in aerial spraying were reviewed and summarized, and it was found that DRTs in aerial spraying can effectively reduce the environmental pollution caused by pesticide drift by reducing the spraying amount of pesticides and improving the control effect of pesticides, included aerial electrostatic spray technology, aerial spray adjuvant, aerial air-assisted spray technology, drift reducing nozzles and aerial variable-rate spray technology. And according to the analysis of the current research status, some suggestions and countermeasures to reduce droplet drift of agricultural aviation spraying were put forward from the aspects of strengthening the research on DRTs for plant protection Unmanned Aerial Vehicle (UAV) and adopting reasonable DRTs methods. It is hoped that provide reference and guidance for the enterprises’ product improvement and users’ practical operation, and play the advantages of precision agricultural aviation spraying fully [ABSTRACT FROM AUTHOR]

A review of the advancements in the knowledge of electrostatic solitary waves (ESWs) made with data obtained by the four satellite Cluster mission, after 20 years in orbit, is presented. ESWs are nonlinear solitary waves or structures observed in high time resolution waveform data. The ESW pulses are the wave data representation of electron or ion phase‐space holes, or density/acoustic structures, and are observed throughout the Cluster orbit, particularly at boundary layers, in turbulent plasmas, and wherever there is mixing of plasmas, such as in the magnetotail with the onset of a super‐substorm. Much of the research reviewed here involves ESWs involved in the magnetic reconnection processes of Earth, with their mapping across the separatrix region. One of the major advancements in ESW knowledge came from investigating propagation from one spacecraft to another, thus addressing the issue of lifetime and stability of these structures which cannot be adequately addressed with single spacecraft propagation studies. Knowing how stable the ESWs are can help determine their generation mechanism, which was also addressed in many of the papers discussed herein through observations and theory. The ESWs were found to be generated through a mix of instabilities and processes, namely two‐stream, Buneman, bump‐on‐tail, electron‐ion, beam‐plasma, electron and ion acoustic instabilities, and out of turbulence. Key Points: Twenty years of Cluster data have led to new insight into nonlinear electrostatic solitary waves and their role in geophysical processesFirst reports of electrostatic solitary waves propagating from one spacecraft to another over a few tens of millisecondsSignificant advancement in knowledge of location and role of electrostatic solitary waves in magnetic reconnection region [ABSTRACT FROM AUTHOR]

This study aimed to clarify the effect of electrostatic spraying of lactic acid (LE) and ascorbic acid (AE) on vacuum-packaged beef aged at 10 °C. The physicochemical attributes, flavor profiles, and microbial diversities were evaluated. Beef steaks were electrostatically sprayed twice with 4% LE, 0.5% AE, or a mixture of them (LAE). Afterward, the beef was vacuum-packaged and aged. All treated beef exhibited a decrease in quality and sensory scores over time. At the end of the study period, the total viable count (TVC) and the total volatile basic nitrogen values in the control group (7.34 log CFU/g and 15.52 mg/100 g, respectively) were higher than those in the acid-treated groups. The LAE group exhibited the best color stability and the lowest TVC and Enterobacteriaceae counts after aging. High-throughput sequencing analysis revealed that acid types and electrostatic spray could change the microbiota structure. Leuconostoc was the dominant bacteria in the AE and LAE groups, while Enterococcus became the predominant bacteria in the NLE and LE groups with aging. This indicates that electrostatic spray combined with acid treatment can ensure beef quality and microbiological safety at mild temperatures. [ABSTRACT FROM AUTHOR]

The utilization of basic fibroblast growth factor (bFGF) in the development of tissue-engineered scaffolds is both challenging and imperative. In our pursuit of creating a scaffold that aligns with the natural healing process, we initially fabricated chitosan-bFGF nanoparticles (CS-bFGF NPs) through electrostatic spraying. Subsequently, polylactic acid (PLA) fiber was prepared using electrospinning technique, and the CS-bFGF NPs were uniformly embedded within the pores of porous PLA fibers. Scanning electron micrographs illustrate the smooth surface of the nanoparticles, showing a porous structure intricately attached to PLA fibers. Fourier-transform infrared spectroscopy (FTIR), energy-dispersive X-ray spectroscopy (EDS), and X-ray diffraction (XRD) analyses provided conclusive evidence that the CS-bFGF NPs were uniformly distributed throughout the porous PLA fibers, forming a robust physical bond through electrostatic adsorption. The resultant scaffolds exhibited commendable mechanical properties and hydrophilicity, facilitating a sustained-release for 72 h. Furthermore, the biocompatibility and degradation performance of the scaffolds were substantiated by monitoring conductivity and pH changes in pure water over different time intervals, complemented by scanning electron microscopy (SEM) observations. Cell experiments confirmed the cytocompatibility of the scaffolds. In animal studies, the group treated with 16 % NPs/Scaffold demonstrated the highest epidermal reconstruction rate. In summary, our developed materials present a promising candidate for serving as a tissue engineering scaffold, showcasing exceptional biocompatibility, sustained-release characteristics, and substantial potential for promoting epidermal regeneration. • Using bFGF as a model, a novel method of loading susceptible inactivating substances onto tissue-engineered scaffolds was designed; • The loading process does not use organic solvents and is not chemically reactive; • Relying on the capillary effect and turbulence effect to make nanoparticles uniformly distributed on the fibers, adsorption is achieved through the high surface energy between nanoparticles and fibers. [ABSTRACT FROM AUTHOR]

[Display omitted] • The coacervates retained their structural integrity during gastric digestion. • Yoghurt with free ingredients resulted in lower cumulated protein release than the others. • Yoghurt with spray-dried coacervates resulted in higher free NH 2 release than the others. • The coacervates promoted the controlled release of free fatty acids in the intestinal phase. Flaxseed oil coacervates were produced by complex coacervation using soluble pea protein and gum arabic as shell materials, followed by either spray or electrostatic spray drying and their incorporation to yoghurt. Three yoghurt formulations were prepared: yoghurt with spray-dried microcapsules (Y-SD); with electrospray-dried microcapsules (Y-ES); with the encapsulation ingredients added in free form (Y). The standardised semi-dynamic in vitro digestion method (INFOGEST) was employed to study the food digestion. The structure was analysed by confocal laser scanning microscopy and particle size distribution. Protein and lipid digestion were monitored by cumulated protein/free NH 2 release and cumulated free fatty acids release, respectively. Stable microcapsules were observed during gastric digestion, but there was no significant difference in protein release/hydrolysis among samples until 55 min of gastric digestion. Formulation Y showed less protein release after 74 min (40.46 %) due to the free SPP being available and positively charged at pH 2–4, resulting in interactions with other constituents of the yoghurt, which delayed its release/hydrolysis. The total release of protein and free NH 2 by the end of intestinal digestions ranged between 46.56–61.15 % and 0.83–1.57 µmol/g protein, respectively. A higher release of free fatty acids from formulation Y occurred at the end of intestinal digestion, implying that coacervates promoted the delayed release of encapsulated oil. In summary, incorporating protein–polysaccharides-based coacervates in yoghurt enabled the delay of the digestion of encapsulated lipids but accelerated the digestion of protein, suggesting a promising approach for various food applications. [ABSTRACT FROM AUTHOR]

Orchard pesticide applications using electrostatic spraying technology enhance droplet deposition and reduce environmental pollution. However, the incorporation of charging systems into conventional air-assisted sprayers remains limited. This is primarily due to challenges such as the necessity for high air velocity to prevent droplet adherence to electrodes, electrode-nozzle design flaws, and safety concerns related to the high voltage used for charging. To address these issues, this study developed five charging units that employ insulated induction electrodes, eliminating exposure to external elements. These units were incorporated into an air-assisted sprayer to assess their effectiveness in charging spray droplets and improving deposition. The units successfully limited electrical leakage, even under high-voltage conditions (up to 18 kV) and in the absence of airflow. At an electrode voltage of 14 kV, and an air velocity of 27 m s−1, the electrostatic units achieved an average charge-to-mass ratio of up to 0.67 mC kg−1. Activation of the charging units significantly enhanced droplet deposition with an increase of 90% on the front and 3250% on the back surfaces of the artificial targets (aluminum plates). On real plant leaves, the increase was 54% on the front and 112% on the back surfaces compared with uncharged standard spraying. [Display omitted] • Electrostatic charging units using insulated induction electrodes were successfully developed for air-assisted orchard sprayers. • The insulating layer of electrodes improved the charging efficiency by preventing electrical leakage at high voltage levels. • The electrostatic units mounted on an air-assisted sprayer achieved an average charge-to-mass ratio of 0.67 mC kg−1. • Activation of the charging units increased deposition by 54% and 112% on the front and back surfaces of plant leaves, respectively. [ABSTRACT FROM AUTHOR]

• Electrostatic spraying was firstly used in COF-LZU1 formation on membrane substrate. • Membrane fouling behavior in DCMD for different ECs was systematically investigated. • COF-based membrane performance in temperature changing DCMD process was studied. Emerging contaminants (ECs) in aqueous ecosystem are becoming a global threat to human beings, which are mainly discharged from industrial wastewater. Direct contact membrane distillation (DCMD) can utilize waste heat to treat industrial wastewater containing ECs, achieving a better balance between removal efficiency and operation cost than other technologies. However, membrane fouling is the major obstacle that impedes DCMD application. Therefore, anti-fouling covalent organic framework COF-LZU1/PVDF composite membranes were prepared via electrostatic spraying and used in DCMD for the first time. Four typical EC compounds (ibuprofen, acesulfame, sulfamethoxazole, and N,N-diethyl-3-methylbenzamide) were selected as targets to investigate the effect of water affinity and charge on membrane fouling. Results showed that COF-1.0 membrane with relatively hydrophilic COF-LZU1 structure exhibited higher permeate flux and salt rejection than commercial PVDF substrate when treating sulfamethoxazole and ibuprofen within pH range of 4–7 and temperature of 40–70 °C. This could be attributed to the weaker hydrophobicity and closer-to-neutral zeta potential of COF-1.0, which weakened the electrostatic and hydrophobic-hydrophobic interactions between membrane and ECs. In addition, the membrane performance comparison in temperature changing DCMD process further showed that COF-1.0 performed better in terms of permeate flux, especially in the gradually decreased temperature condition. Overall, these findings would advance the fundamental understanding and practical application of COF-based membranes in DCMD for ECs treatment. [ABSTRACT FROM AUTHOR]

The study focused on the role of Nattokinase/Sodium alginate/Chitosan microcapsules (NK/SA/CS microcapsules) in preserving nattokinase activity in the gastrointestinal system and attenuating atherosclerosis. The thrombolytic activity of NK would normally be lost in acidic gastric fluid after oral administration. To address this issue, the researchers developed a novel delivery system using alginate- and chitosan-encapsulated microcapsules. The NK/SA/CS microcapsules protected the loaded NK from deactivation by gastric fluid, as demonstrated by in vitro and in vivo tests. The NK/SA/CS microcapsules retained 80.41% enzyme activity in simulated gastric fluid and 50.69% in the gastric content of mice after 2 h. In atherosclerosis models, the NK/SA/CS microcapsules were found to reduce body weight and epididymal adipose weight in mice. Furthermore, they effectively managed the progression of atherosclerosis and significantly improved the lipid profile. Overall, the study highlights the potential of the NK/SA/CS microcapsules as a delivery system for NK, protecting its activity in the presence of gastric fluid and demonstrating positive therapeutic effects regarding weight management and atherosclerosis progression. Note: An electrostatic spraying device was used to form NK/SA/CS microcapsules. The NK/SA/CS microcapsules protected the loaded NK from damage by gastric fluid, as demonstrated by in vitro and in vivo tests. The NK/SA/CS microcapsules reduced the weight of mice, regulated blood lipid levels, and alleviated atherosclerosis symptoms. [Display omitted] • Optimization of nattokinase fermentation conditions by response surface methodology. • The microcapsules protected nattokinase from deactivation by gastric fluid. • The microcapsules effectively managed the progression of atherosclerosis. [ABSTRACT FROM AUTHOR]

A polymer coating is an effective approach to increase the surface wear and corrosion resistance of magnesium alloys, but the low bonding strength limits its further applications. In this study, poly-ether-ether-ketone (PEEK) coating was prepared on the AZ31 magnesium alloy. Femtosecond laser surface treatment was used to change the surface characteristics of Mg-base alloy, and the effect of the laser-induced structures on improving the bonding strength of PEEK coating was investigated. With the increase in laser energy, the gap between laser-induced nanostructures gradually increases. When V = 1000 mm s−1, a uniform striped structure is formed on the surface, and the average period is about 0.5 μm. When V = 300 mm s−1, the stripe breaks and grows in the length direction, and the surface texture tends to be a coral-like structure with diameter of about 7 μm. When the scanning speed is reduced to V = 200 mm s−1, the grooves gradually deepen, and irregular bumped structures were formed with the spacing of about 3 ~ 5 μm. The surface roughness after laser treatment increased from 9.37 nm to 589.3 nm, and the surface of magnesium alloy changed from hydrophilic to hydrophobic. PEEK coating was prepared by electrostatic spraying. The raw PEEK is fully melted and infiltrated with the laser-induced structure matrix, resulting in a high bonding strength compared with the untreated Mg matrix. The surface of the nanostructure has excellent wettability to PEEK coating, which improves the adhesion of coating and prolongs the service life of the magnesium alloy. PEEK coating has excellent sealing effect and chemical corrosion resistance, which increases the corrosion potential on the substrate surface and the corrosion resistance. Results can provide a new approach to improve the bonding properties between metal bases and polymer coating. [ABSTRACT FROM AUTHOR]

Polyester coatings are among the most commonly used types of powder paints and present a wide range of applications. Apart from its decorative values, polyester coating successfully prevents the substrate from environmental deterioration. This work investigates the cavitation erosion (CE) resistance of three commercial polyester coatings electrostatic spray onto AW-6060 aluminium alloy substrate. Effect of coatings repainting (single- and double-layer deposits) and effect of surface finish (matt, silk gloss and structural) on resistance to cavitation were comparatively studied. The following research methods were used: CE testing using ASTM G32 procedure, 3D profilometry evaluation, light optical microscopy, scanning electron microscopy, optical profilometry and FTIR spectroscopy. Electrostatic spray coatings present higher CE resistance than aluminium alloy. The matt finish double-layer (M2) and single-layer silk gloss finish (S1) are the most resistant to CE. The structural paint showed the lowest resistance to cavitation wear which derives from the rougher surface finish. The CE mechanism of polyester coatings relies on the material brittle-ductile behaviour, cracks formation, lateral net-cracking growth and removal of chunk coating material and craters' growth. Repainting does not harm the properties of the coatings. Therefore, it can be utilised to regenerate or smother the polyester coating finish along with improvement of their CE resistance. [ABSTRACT FROM AUTHOR]

From the raindrops of lightning to atomized droplets used in many fields, research on electrostatic spray technology has both a natural basis and practical significance. The utilization of electrostatic spray technology has covered the biological, food, pharmaceutical, industrial, agricultural, chemical, and manufacturing industries. To provide comprehensive information about the technology, this review presents a typical electrostatic spray system in terms of its atomization mechanism, electrostatic spray modes, and several kinds of basic parameters. This review focuses on the applications of electrostatic spray technology in the fields of nanomaterial preparation, agricultural plant protection, wet flue gas desulfurization (WFGD), and fuel combustion. This paper comprehensively surveys already well-established or future potential applications of electrostatic spray technology. [ABSTRACT FROM AUTHOR]

The reducing and synergistic effects of three spray adjuvants, including 63% Jijian AS, 3% Anrongle SE and 75% Chaojiabi EC, and electrostatic sprayer on clodinafop-propargyl were determined by field experiments. The results showed that the spray adjuvants Jijian, Anrongle and Chaojiabi had obvious synergistic effects on clodinafop-propargyl applied by knapsack manual sprayer. The total weed control efficacy of 15% clodinafop-propargyl WP 34 g a.i./hm² plus Jijian 225 mL/hm², Anrongle 90 mL/hm² or Chaojiabi 240 mL/hm² (dosage of preparation, the same below) was significantly better than that of 15% clodinafop-propargyl WP 34 g a.i./hm² and 45 g a.i./ hm² alone. The control efficacy of 15% clodinafop-propargyl WP 34 g a.i./hm² plus Jijian 225 mL/hm² or Anrongle 90 mL/hm² was the same as that of 15% clodinafop-propargyl WP 68 g a.i./hm2 alone. Compared with conventional sprayer, the application of electrostatic sprayer significantly improved the control efficacy of 15% clodinafoppropargyl WP on weeds. The control efficacy of 15% clodinafop-propargyl WP 34 g a.i./hm² sprayed by electrostatic sprayer was significantly better than that of 15% clodinafop-propargyl WP 68 g a.i./hm² sprayed by conventional sprayer. The applications of spray adjuvants and electrostatic sprayer were safe to wheat growth and could increase wheat yield obviously, which were effective measures to reduce the amount of herbicides. [ABSTRACT FROM AUTHOR]

The chondroitin sulfate (CS)/sodium alginate (SA)/chitosan nanoparticles were prepared by electrostatic spraying technology. Laser particle size analyzer measurements indicated that the size of the particles is strongly affected by the weight ratio of raw materials, receiver rotation speed, injection rate, and so on. The size increased and size distribution moved towards the direction of large particle size with the decrease of applied voltage and increased with the increase of the flow rate and weight ratio of SA to CS; there is an optimal value for the effect of stirring rate on particle size and particle size distribution. The effect of different weight ratios of raw materials and pH on the sustained release rate of the product was investigated using a UV-visible spectrophotometer. Results showed the cumulative release rate of these particles was weight ratio of SA to CS and pH-dependent. The cumulative release rate of the CS/SA/chitosan composite nanoparticles with a weight ratio of SA to CS of 2 : 1 was higher at pH 6.8 than that at pH 1.2. By optimizing the process parameters, the CS/SA/chitosan composite particles were prepared, in which most of CS could pass through the stomach and release in the intestinal tract. [ABSTRACT FROM AUTHOR]

Electrical discharge and electrostatics are used for the industrial application of a copying machine and electrostatic spraying. However, the electrical discharge and electrostatics occasionally cause malfunction or failure of electronic equipment. When a human body moves in an office, it is electrified up to 10 kV or more. A microelectronic device used in the electronic equipment causes an error owing to the voltage of less than 10 V. When the charged human body moves near the electronic equipment, high induced voltage is generated in the metal box. Comprising electronic equipment, the box is occasionally used at the floating potential of an ungrounded condition. The induced voltage generated for the ungrounded metal box is higher than that generated for the grounded metal box. The results show that the induced voltage generated in an ungrounded metal box is 120% of the inverse polarity against a charged body when the charged body moves away from the box. The induced voltage generated in the ungrounded metal box is higher than that generated on the box. These results would be helpful in designing electronic equipment without malfunctions or failure. [ABSTRACT FROM AUTHOR]

Graphene-based materials such as graphene oxide (GO) and chemically reduced graphene oxide (rGO) thin films have been fabricated using electrostatic spray deposition (ESD), followed by thermal annealing under Ar/H2 atmosphere. The thickness and surface morphology of thin films of GO and rGO on silicon substrates were controlled by varying deposition time and content of GO/rGO in tetrahydrofuran (THF) solution. Here, we present a comparative analysis between GO and rGO thin films. Water contact angle (WCA) measurements of these thin films were ~88° for the GO films and >127° for the rGO films. We discuss how their hydrophobic behaviour is influenced by removal of oxygen-containing functional groups during the reduction process. [ABSTRACT FROM AUTHOR]

In the present study, we evaluated the antimicrobial activity of passion fruit peel extract (PPE) against Escherichia coli O157:H7 and Listeria monocytogenes. The application of PPE using an electrostatic spraying system for the disinfection of fresh-cut Lollo Rossa and beetroot leaves was also examined and compared with conventional PPE washing. Time-kill assays indicated that PPE had antibacterial activity against Escherichia coli O157:H7 and Listeria monocytogenes, effectively reducing the populations of the pathogenic bacteria within 3 h following treatment with 6 mg/mL PPE. Confocal laser scanning microscopy and scanning electron microscopy showed that PPE treatment caused bacterial cell death by damaging the cell membrane. PPE treatment produced significant decontamination against the pathogens on fresh-cut vegetables. Electrostatic spraying of 6 mg/mL PPE for 20 s decreased the populations of pathogenic bacteria on Lollo Rossa and beetroot leaves by 2.29–2.86 log CFU/g, regardless of the difference in the contact angle and surface roughness of the vegetables. Our results showed that electrostatic spraying of PPE was more effective than washing with PPE. Electrostatic spraying of PPE did not affect the color and texture of fresh-cut Lollo Rossa leaves during storage, suggesting that it can be used as a novel disinfection method. [ABSTRACT FROM AUTHOR]

Aerial electrostatic spray technology for agriculture is the integration of precision agricultural aviation and electrostatic spray technology. It is one of the research topics that have been paid close attention to by scholars in the field of agricultural aviation. This study summarizes the development of airborne electrostatic spray technology for agricultural use in China, including the early research and exploration of Chinese institutions and researchers in the aspects of nozzle structure design optimization and theoretical simulation. The research progress of UAV-based aerial electrostatic spray technology for agricultural use in China was expounded from the aspects of nozzle modification, technical feasibility study, influencing mechanism of various factors, and field efficiency tests. According to the current development of agricultural UAVs and the characteristics of the farmland environment in China, the UAV-based aerial electrostatic spray technology, which carries the airborne electrostatic spray system on the plant protection UAVs, has a wide potential in the future. At present, the application of UAV-based aerial electrostatic spray technology has yet to be further improved due to several factors, such as the optimization of the test technology for charged droplets, the impact of UAV rotor wind field, comparison study on charging modes, and the lack of technical accumulation in the research of aerial electrostatic spray technology. With the continuous improvement of the research system of agricultural aviation electrostatic spray technology, UAV-based electrostatic spray technology will give play to the advantages in increasing the droplets deposition on the target and reducing environmental pollution from the application of pesticides. This study is capable of providing a reference for the development of the UAV-based agricultural electrostatic spray technology and the spray equipment. [ABSTRACT FROM AUTHOR]

Copyright of Wool Textile Journal is the property of National Wool Textile Science & Technology Information Center and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The electrostatic spray method is a promising nonvacuum technique for efficient deposition of thin films from solutions or dispersions. The multitude of electrostatic spray process parameters, including surface tension, viscosity, and conductivity of the liquid, applied voltage, nozzle size, and flow rate, make electrostatic spray deposition very versatile for the morphological engineering of nanostructured films. The current state‐of‐the‐art in electrostatic spraying can produce exceptional morphologies. Such tailoring of morphologies is notably useful in electrochemical applications where high electrolyte‐accessible surface area often improves performance. Interesting morphologies of metal oxides and their composites are highlighted, including nanopillars, nanoferns, and porous microspheres produced by electrostatic spraying to enhance energy conversion and storage performance. The physics associated with the electrostatic spray process and morphology control using it are also presented. The manuscript highlights the potential of electrospray processing for producing thin films of controlled microstructure, from ultrasmooth layers in organic photovoltaics and perovskite photovoltaics to hierarchical nanostructured films for anodes and photoanodes. It aims to help researchers appreciate essential aspects of electrostatic spray deposition efficiency, process control, and morphology engineering for energy conversion (e.g., solar cell, fuel cell, and photoelectrochemical cell) and energy storage (e.g., lithium‐ion battery and supercapacitor) electrodes. [ABSTRACT FROM AUTHOR]

The preparation by electrospraying of a bilayer film formed by a pectin layer (hydrophilic, polar) and a zein layer (hydrophobic, nonpolar), is a difficult task that has not yet been reported. Herein, the feasibility of producing films by electrostatic atomization was studied, as well as the changes in the superficial and physicochemical characteristics of the bilayer film. Results showed that it is possible to produce a flexible and yellow bilayer film (101.07 ± 8.11 μm) with a continuous surface structure and a well‐defined interface, without chemical interactions between both layers nor antimicrobial activity. This study is one of the first to show that the electrospraying technique can be used to generate biodegradable bilayer films using hydrophilic/hydrophobic biopolymer solutions. [ABSTRACT FROM AUTHOR]

Chemical pesticide residues have posed a great impact on crops and the ecological environment in recent years, as the prevention and control of crop diseases and pests have widely been used in agricultural production. Consequently, an aerial pesticide application technology has become an effective way for plant protection in modern agriculture. The powerful technology is characterized to reduce the numbers and residues of pesticides for the better effectiveness of pesticide application. Alternatively, a high-voltage electrostatic device is often used to charge the spray droplets in an electrostatic spray system. Specifically, the chemical liquid is atomized into droplets near the nozzle to obtain a charge of the same polarity as the nozzle. An electrostatic field is then formed between the nozzle and the crop target under the action of high-voltage static electricity. As such, the droplets of opposite polarity are quickly adsorbed on the front and back of crop targets during the spraying process. Aerial electrostatic spraying is a deep integration of electrostatic spray system and aviation pesticide spraying in precision agriculture. The droplets can quickly be deposited along the power line in the process of aircraft spraying, thereby greatly reducing the drift loss for highly efficient deposition of droplets. Furthermore, the electrostatic spray technology has achieved excellent control effects on crops, fruit trees, and greenhouse vegetables in field tests. The top countries of aerial electrostatic spray technology in the world are the United States and Brazil, in terms of technology usage, and innovation. Particularly, the electrostatic spray technology in the United States has been fully commercialized for the aviation spraying equipment. In addition, an efficient aircraft is highly required for large-scale planting and plant protection in vast arable land and mostly plains in some developing countries. The manned fixed-wing aircraft is mainly used in electrostatic spray systems at present. This review outlined the international development of aerial electrostatic spraying technology to further clarify two main lines of reports at home and aboard, ranging from basic theoretical research to commercialization process. An application level of technology was set to analyze in China. The research on aviation electrostatic spray technology in China has presented a promising increase trend, due mainly to small environmental and topographical impacts in field tests. Moreover, the unmanned aerial vehicle (UAV) has become the most suitable aircraft equipped with an electrostatic spray system after long-term research. However, large research gaps still remained in manned vehicles and lately commercial plant protection UAV, compared with the state-of-the-art electrostatic spray technologies overseas. There were also numerously repeated and invalid studies overlapped in the main parameters in China. Anyway, it is still necessary to delve into the specific interaction mechanism between the process of spraying droplets and the operating parameters. The industrialized development of aviation electrostatic spray system was also reviewed at the end, together with the development prospects. Some suggestions were listed as: (1) The performance of each charge needed to be elucidated in the aerial electrostatic spray system. (2) The measurement technology of charged droplet deposition was highly demanding to accurately evaluate the actual properties of electrostatic spray. (3) Measurement of charge-to-mass ratio was necessary to rethinking using the cutting-edged quantum theories. An ever-increasing demand is coming soon using aviation electrostatic spray system for crop protection. [ABSTRACT FROM AUTHOR]

To improve the utilization of platinum and reduce the manufacturing cost of proton exchange membrane fuel cell (PEMFC), the electrostatic spraying was used to prepare the cathode catalyst layer of membrane electrode assembly (MEA) with platinum loading varying from 0.1 to 0.01 mg cm−2. The performance of fuel cell was tested and analyzed by electrochemical impedance and polarization curve. Our results show that the platinum carbon (Pt/C) particles deposited by electrostatic spraying were well dispersed and the microporous structure of catalyst layer (CL) were relatively uniform. Replacing the CCS type MEA (catalyst coated on gas diffusion layer substrate) with the CCM type MEA (catalyst coated on proton exchange membrane) can reduce its electrochemical impedance and improve the power density of fuel cell. Compared to the Pt/C catalyst with a platinum mass fraction of 60%, a lower platinum-carbon ratio catalyst is more conducive to the uniform dispersion of catalyst particles and efficient utilization of platinum in the preparation of MEA with ultra-low platinum loading. However, their difference in peak power density decreases with the increase of platinum loading. Besides, increasing the back pressure can improve the performance of fuel cell, when the back pressure increased to 0.15 Mpa and the feeding gases were set as H 2 /O 2 , the peak power density of 0.56 W cm−2 was obtained by the MEA with cathode platinum loading of 0.01 mg cm−2, which is corresponding to the cathode platinum utilization of 56 kW·g Pt −1 cathode. • CL with Pt loading from 0.01 to 0.1 mg/cm2 is prepared by electrostatic spraying. • CCM type MEA has smaller electrochemical impedance and higher power density. • Low Pt–C ratio catalyst contributes to dispersion and efficient utilization of Pt. • MEA with cathode Pt loading of 0.01 mg/cm2 exhibits a peak power density of 0.56 W/cm2. [ABSTRACT FROM AUTHOR]

This study aimed to assess, in a microcosm condition, the efficacy of electrostatic spraying of herbicide imazamox in the control of Salvinia molesta and the effects of decomposition of plant material on water quality. The herbicide rates used were 600, 700, 800, and 900 g ai ha−1 and spray volume of 50 L ha−1 in electrostatic application. Control effectiveness was assessed at 7, 15, 30, 45, and 60 days after application (DAA), expressed in percentage (0–100%) of visible injury symptoms in the plants, biochemical oxygen demand (BOD5), chemical oxygen demand (COD), chlorophyll a and pheophytin a contents at 0, 7, 15, 30, 45, and 60 DAA, and fresh and dry biomass at 60 DAA. Imazamox was effective in controlling 63% of S. molesta with 900 g ai ha−1 in 45 DAA and 30% with 800 g ai ha−1 in 30 DAA, and reduced 82.3% and 17.5% of fresh weight and 62.6% and 9.3% of dry weight of plant at 60 DAA, respectively. The imazamox spray reduced chlorophyll a with all doses applied and increased BOD5 in 45 DAA with 900 g ai ha−1 and COD in all assessment periods, but for temperature, dissolved oxygen, electrical conductivity, and pH, there was no significant effect after spraying. The herbicide imazamox reduced S. molesta plants with 900 g ai ha−1, without causing significant effects on environmental indicators of water quality. Electrostatic spraying of herbicide can be used in management strategies of aquatic plants to reduce plant density in water bodies and maintain the colonization of plants at a level not harmful to the aquatic biota. [ABSTRACT FROM AUTHOR]

Hydrogen peroxide (H2O2) can be considered as a sterilant or a green propellant. For a common use in industrial application, spray is an effective method to form fine H2O2 droplets. In this paper, electrostatic atomization based on the configuration of needle ring electrodes is proposed to produce H2O2 spray by minimizing its effective surface tension. The breakup performances of H2O2 ligaments can be improved by increasing the electric field intensity, reducing the nozzle size, and adjusting suitable volume flow rate. The smallest average diameter of breakup droplets for 35 wt. % concentration H2O2 solution reached 92.8 μm under optimum operation conditions. The H2O2 concentration significantly influenced the breakup performance owing to the concentration effect on comprehensive physical properties such as density, surface tension, viscosity, and permittivity. The average diameters of breakup droplets decreased with decreasing H2O2 concentration. At 8 wt. % concentration, the average breakup droplet diameter was reduced to 67.4 μm. Finally, electrostatic atomization mechanism of H2O2 solution was analyzed by calculating dimensionless parameters of Re, We, and Oh numbers with the combination of the operation conditions and physical properties for in-depth understanding the breakup behaviors. The calculation showed that the minimum average diameter of breakup droplets was obtained at 8 wt. % concentration at the investigated range of H2O2 concentration, which kept in agreement with the experimental results.

Electrostatic spraying is a new generation of green and efficient cooling/lubrication technique in machining. Critical heat flux reflects the heat transfer potential of electrostatic spraying. In this paper, an evaluation device for cooling capacity of electrostatic spraying is developed to study the effects of voltage, target distance, flow rate of nanofluids, and volume fraction of nanoparticles on critical heat flux by transient heat transfer tests. The electrostatic field between the nozzle and the heat transfer surface is simulated to analyze the heat transfer mechanism. The results show that the critical heat flux is greatly affected by the thermophysical properties of nanofluids, the electric field strength, and the deposition of nanoparticles on the heat transfer surface. Under the cone-jet mode, increasing voltage, flow rate of nanofluids, and volume fraction of nanoparticles and reducing target distance can considerably increase critical heat flux. The maximum critical heat flux can be obtained when the voltage, target distance, flow rate of nanofluids, and volume fraction of nanoparticles are taken as − 8.4 kV, 15 mm, 0.63 ml/min, and 0.15%, respectively. [ABSTRACT FROM AUTHOR]

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Porous Ni-Mn-oxide film on Ni foam was fabricated through electrostatic spray deposition (ESD) and subsequently calcination under argon atmosphere. The porous Ni-Mn-oxide architecture was composed of Mn2O3 and NiMnO3 composite structure. When used as lithium-ion battery (LIB) anode, the Ni-Mn-oxide electrode exhibits superior cycleability (902 mAh g−1 after 100 cycles at 400 mA g−1) and good rate capacity. The superior electrochemical property for the porous Ni-Mn-oxide film on Ni foam can be associated with the unique architecture, which can offer enough void space to buffer volume change in the charge/discharge process and provide more reactive sites in the electrochemical reaction. [ABSTRACT FROM AUTHOR]

In this article, a hybrid system of hydrogel/frog egg‐like microspheres (H‐FMS) formed by the combination of coaxial electrostatic spraying and freeze‐drying was introduced for enhancing wound healing efficiency through the sustained release of Rana chensinensis skin peptides (RCSPs). The porous PVA/gelatin hydrogel were obtained and frog egg‐like microspheres (FMS) of sodium alginate (SA), shaping uniform and smooth, were embedded into hydrogel. Based on PVA/gelatin hydrogel, the FMS addition increased the water absorption of hydrogel to 1,105%. RCSPs were more effectively encapsulated into FMS than solid microspheres (MS). Not only does the H‐FMS act as good "depots" for sustained release of RCSPs over 9 days, without exhibiting obvious burst release, but also show good biocompatibility in vitro. In vivo studies on wound healing as well as the histology of fibroblasts, re‐epithelialization, inflammation, and hair follicles indicated that the structure of H‐FMS released RCSPs continuously and promoted wound healing in rats significantly. [ABSTRACT FROM AUTHOR]

Orchard spray is a key link to orchard production, due to it occupied nearly 25% of the total workload of orchard management. Moreover, the degree of plant protection mechanization directly affects the economic benefits of fruits. In this review, the orchard characteristic, the general situation of plant protection mechanization and the reasons restricting its development were introduced briefly, in order to clarify the future progress of mechanization technology and equipment for the orchard plant protection in China. The main reason impeding the development of plant protection mechanization can be a large proportion of hilly orchards, including gradient, slope and flat orchard, together with a very complex planting environment. Since the standardized modern orchards are being promoted, the scale is still small, due partly to the extensive management in traditional orchards the high price. Currently, the plant protection mechanization level of flat orchard was 15%, whereas, the hilly orchard was only 7.5%. Therefore, the progress of key plant protection mechanization technologies and equipment was presented in detail, further to improve the mechanization level of plant protection. For example, the pipeline spraying technology and equipment brought good benefits and spraying effects to the hilly orchard, while, the application of air-assisted spraying technology and equipment improved the mechanized operation level of the flat orchard. Electrostatic spraying technology and equipment were especially used to enhance the droplet coverage rate on the back of leaves. While the tunnel spraying technology and equipment increased the droplet density on the canopies, to recovery the droplet that left the target, indicating that it can effectively improve the pesticide utilization. Variable rate spraying technology and equipment were becoming a hot research topic, particularly on the precise control of spray on demand. The core technology of variable rate spraying was target detection, such as ultrasonic detection, laser detection, infrared detection, machine vision methods. The ultrasonic and laser detection methods have achieved the best application. Since 2010, the great development and application of aerial spraying technology and equipment have been widely recognized. Especially, the unmanned aerial vehicle (UAV) of rotor plant protection has become one of the most popular machines with small size, fast flight speed and strong terrain adaptability among the agricultural aerial equipment. In this review, the research state of rotor plant protection UAV in orchard was introduced from three aspects: operation model, down wash flow field, and working parameters. Plant protection equipment can offer some suggestions for the development of plant protection mechanization from these aspects: promoting standardized models of orchard plant, developing stereo spraying technology, promoting specialized and mechanical service model of plant protection, thereby for the intelligent robots of plant protection. [ABSTRACT FROM AUTHOR]

In order to solve the problem of insufficient adsorption rate of droplets on the target back via aerial electrostatic spray, this study proposed a high-voltage electrostatic generator to charge the liquids in two isolated water tanks with positive and negative charges respectively. A charge transfer loop was developed in space between the aerial electrostatic spray system and the ground. This method greatly enhanced the adsorption performance under outdoor conditions that 16.7% droplets density increased on the target front, a nearly fourfold destiny increased on the target back compared with the conventional UAV spray system. The target back-to-front ratio of droplet density was improved from 6.1% to 25.7%, which validated the satisfactory performance of the developed system. [ABSTRACT FROM AUTHOR]

An improved precipitation method - electrostatic spray precipitation is proposed, which is characterized by introducing the electrostatic atomization effect into the precipitation process. The results display that electrostatic atomization can effectively reduce the size of reaction solution droplets under electrostatic force, the growth process of crystal nucleus is optimized, and then flake cluster MnCO 3 is obtained, which further promotes the formation of homogeneous MnO nanoparticles. Compared with the agglomerated MnO without electrostatic action, homogeneous MnO nanoparticles exhibit better cycling stability (787 mAh g−1 after 100 cycles at 377.5 mA g−1) and rate capability (471 mAh g−1 at 3020 mA g−1). Image, graphical abstract [ABSTRACT FROM AUTHOR]

Compared with minimum quantity lubrication, electrostatic spraying can greatly improve machining and environmental performances. However, the cooling and lubricating performance of electrostatic spraying needs to be further improved. In this paper, the composite electrostatic spray cutting approach is proposed, and the environment-friendly machining of titanium alloy by using this approach is investigated. An atomization test device for composite electrostatic spray cutting and a composite electrostatic spray milling system are developed. The atomization tests for composite electrostatic spray cutting are performed to study its atomization morphology and to determine the atomization parameters that guarantee a stable composite electrostatic spraying. The atomization current is measured by using a picoammeter under stable composite electrostatic spraying conditions, and the charging performance and atomizing stability of composite electrostatic spraying are evaluated. Milling experiments of titanium alloy and ambient oil mist concentration tests are also carried out under electrostatic and composite electrostatic spraying conditions. The effects of composite electrostatic spraying on milling force, tool wear, chip morphology, and oil mist concentration are analyzed. Results show that compared with electrostatic spraying, composite electrostatic spraying can effectively reduce tool wear and oil mist concentration. Under composite electrostatic spraying condition, an increase in the flow rates of internal and external fluids can further reduce tool wear. An increase in the flow rate of internal fluid does not affect ambient oil mist concentration. But an increase in the flow rate of external fluid significantly increases ambient oil mist concentration. [ABSTRACT FROM AUTHOR]

In this work, we have coated MnO2@CeO2 composites onto graphite felts (GF) by electrostatic spraying leading to substantially improved electrochemical performance characteristics of iron redox flow batteries. GF are extensively used as electrodes but they do not have the desired electrochemical properties. MnO2@CeO2 composites have novel electrocatalyst features. Hence, MnO2@CeO2 composites were developed and applied to GF. Chemical and structural features of the bare graphite felt electrode and MnO2@CeO2 composite-modified graphite felt electrode (MGF) were characterized using scanning electron microscopy, energy dispersive X-ray analysis, transmission electron microscopy, X-ray diffraction, and Brunauer–Emmett–Teller surface area analysis. Similarly, the electrochemical performance was investigated using cyclic voltammetry, electrochemical impedance spectroscopy, Tafel, and charge–discharge performance experiments. The charge−discharge experiments were performed at 1 to 3 mg cm− 2 weight of MGFs and varying the current densities from 40 to 70 mA cm− 2. The coulombic efficiency (ηC) and peak power density (PPD) of the cell (132 cm2) determined at 50 mA cm− 2 for 2 mg cm− 2-MGF electrode was found to be 99.10% and 55.56 W cm− 2, respectively. Among the three different types of electrodes, the MGF electrode showed better electrocatalytic performance mainly due to the excellent conducting network of the oxygen moieties of MnO2@CeO2 composites. After 25 cycles, the average ηC and PPD of the cell using 2 mg cm− 2-MGF was found to be 96.06% and 55.16 mW cm− 2, respectively, indicating the good stability of the electrode. [ABSTRACT FROM AUTHOR]

Three-dimensional (3D) porous NiCo 2 N@C composite was deposited on nickel foam substrate through the electrostatic spray deposition (ESD) technique followed by a post-annealing process under ammonia atmosphere. The prepared reticular-structured NiCo 2 N@C film used as binder-free anode for lithium-ion batteries (LIBs) can exhibit excellent electrochemical performance. It delivers high initial discharge capacity of 1215.8 mAh g−1 at a current density of 1 A g−1 and can reach 1630.9 mAh g−1 after 400 cycles. The electrode also shows a superior rate capability with 955.4 mAh g−1 at 10 A g−1 current density. Image, graphical abstract [ABSTRACT FROM AUTHOR]

Zinc oxide films doped with 0 at. %–5 at. % aluminum are fabricated by flow-limited field-injection electrostatic spraying using a sol–gel processed precursor. X-ray diffraction and Rietveld analyses indicate that the films are highly (002)-oriented with large crystallites and that the lattice constants of the doped-ZnO tend to decrease with Al doping below the values of undoped-ZnO. Optical properties were measured by ellipsometry and analyzed using the Drude model of permittivity. The electron scattering rate is calculated to be minimal at 3 at. % Al, which may indicate a reduction in the ionized impurities due to the lattice strain and the absence of Al clusters, which is enabled by the sol–gel precursor. Insights are offered regarding the effects of Al doping on film density, electron concentration, and background permittivity, which may prove important in tuning the film properties for plasmonic applications. [ABSTRACT FROM AUTHOR]

In computational fluid dynamics, the modeling of paint application processes by electrostatic rotary bell sprayer is mostly performed using an Euler–Lagrange approach. The initial conditions of the discrete phase—position, velocity, size, and charge—have an essential influence on the resulting film thickness distribution and the total charge transferred to the object. Typically, so-called injection models are used to specify these initial conditions, whereby the determination of the injection model coefficients is crucial. In this paper, a framework is proposed that combines experimental input data, an injection model, and a metamodel-based optimization. The painting tests for the generation of input and validation data were carried out in a technical center in the industrial standard. The simulations were performed using ANSYSFluent. Initial droplet conditions could efficiently be determined via the framework so that the painting-specific objectives were achieved with reasonable accuracy. In addition to the framework, a turbulence study of the strongly swirled shaping air of this atomizer was carried out, whereby a substantial underestimation of the axial air velocity was found in the turbulence models being investigated. The initial droplet conditions were also used in this study to draw conclusions about the accuracy of the airflow simulation. The proposed framework can be adapted to other solvers and efficiently finds injection model coefficients for other paint applicators. [ABSTRACT FROM AUTHOR]

An open‐cell metallic foam is newly manufactured using the electrostatic powder spraying (EPS) process, and its room temperature compressive and energy absorption properties are investigated. EPS is a process that uses electrostatic forces. The powder is negatively charged by applying direct current high voltage and undergoes electrostatic spraying on a positively charged polyurethane pre‐form. To control relative density (ρ*/ρ), three different spray amounts are applied (2.5, 3.5, and 4.5 kg m−2). Also, the relative density is measured to increase constantly with the spray amount. The room temperature compressive curves of the EPS foams represent the typical compressive stages (linear elastic, plastic collapse, and densification) of metallic foam. The plateau strengths of the EPS foams measure 0.48 MPa (spraying amount: 2.5 kg m−2), 0.76 MPa (spraying amount: 3.5 kg m−2), and 1.23 MPa (spraying amount: 4.5 kg m−2), respectively. Also, EPS 316L foam with the smallest spray amount has a lower energy absorption amount compared with other types of foam. This study also discusses the compressive and energy absorption behaviors of an open‐cell metallic foam manufactured using the EPS process in relation to its structural and microstructural characteristics. [ABSTRACT FROM AUTHOR]

In this work, transparent and flexible humidity sensors based on graphene oxide film were prepared using the electrostatic spray deposition technique. Graphene oxide (GO) powder was synthesized using the modified Hummer's method, which was used as a precursor for thin-film deposition. The properties of GO films were characterized by X-ray diffraction, field-emission scanning electron microscope, Raman spectroscopy, Fourier transform infrared spectroscopy, and UV–Vis spectrophotometer. The effect of substrate temperature on the sensor properties was observed. The impedance of the device exhibited a lower value when increasing the relative humidity level. In addition, the device showed high sensitivity of more than 1117.3, fast response with 5 s, more than 60% optical transparency, and flexible property more than 2000 cycles. In addition, the equivalent circuit models of the devices were evaluated from complex impedance measurements used to explain the sensing mechanisms of the device. [ABSTRACT FROM AUTHOR]

The combustion characteristics of nanofluid fuels have been widely investigated, but rare studies on the atomization were reported. Atomization is an imperative and crucial step to improve the combustion performance of nanofluid fuels, and the secondary breakup of droplets is an important segment for atomization to produce uniform fine droplets and distribute nanoparticles in each droplet. This paper firstly presents the secondary breakup characteristics of single electrified Al/n-decane nanofluid fuel droplets and revealed the mechanism of the secondary breakup. The results demonstrated that fine droplets could be produced in the electrostatic field and Al nanoparticles were distributed in each droplet. Before the breakup, the single electrified droplets experienced surface charge transportation, deformation, and Taylor cone formation. A gradient of the electric field deformed the droplet to produce the Taylor cone. As the Taylor cones were stabilized, the fluid was extruded from the tips of stable Taylor cones to produce jet filament parallel to the electric field direction and correspondingly broke up into fine sub droplets. At the nanoparticle concentration range of 1.0~10 mg/mL, the minimum average diameter of breakup sub droplets could achieve ~55.4 μm at 6.0 mg/mL. The Al nanoparticle concentration had a significant effect on the breakup performance by influencing the physical properties and charging. The order of the Charge-to-Mass ratio magnitude was 10−7~10−5 C/kg. Furthermore, the secondary breakup mechanism of single electrified nanofluid fuel droplets in the uniform electrostatic field was revealed by analyzing the droplet surface charge, deformation, Taylor cone formation, and nanoparticle concentration effect. [ABSTRACT FROM AUTHOR]