Search Results (617)

The atomization performance of the nozzle is a critical factor influencing the pesticide application efficiency and drift behavior of agricultural unmanned aerial spraying systems (UASSs). However, the underlying atomization mechanisms of such nozzles have not yet been fully elucidated. In this study, a Particle Image Velocimetry (PIV) system was employed to evaluate the liquid sheet breakup mode, breakup length, droplet size distribution, and velocity distribution of a fan-shaped nozzle used in UASSs. Experiments were conducted under a series of spray pressures (ranging from 0.10 to 0.50 MPa, with an increment of 0.05 MPa) using sodium dodecylbenzenesulfonate (SDS) surfactant solutions at four concentrations (0%, 0.2%, 0.5%, and 1.0%). The results demonstrated that both the SDS surfactant and spray pressure significantly influenced the liquid sheet breakup process and atomization behavior. High concentrations of surfactant solution had a pronounced effect on the surface tension of the spraying liquid, delaying the onset of liquid sheet breakup, enlarging the overall droplet size distribution, and reducing the droplet velocity components along the X-axis and Y-axis. Conversely, higher spray pressures facilitated liquid sheet breakup, decreased the overall droplet size, and increased the droplet velocity distribution. This study provides fundamental experimental data for quantifying the effects of solution surface tension and spray pressure on the atomization performance of fan-shaped nozzles. These data provide systematic support for the evaluation of nozzle atomization performance. Full article

This study presents experimental research on the injection of water–methanol mixtures under both subcooled and superheated conditions. Injecting superheated liquid results in the formation of flash-boiling sprays, generating smaller droplets compared to non-superheated conditions. This improved atomisation leads to a decrease in spray penetration and evaporation time. The mixture of water and methanol is a non-azeotropic mixture, meaning it exhibits different bubble and dew points. Non-azeotropic mixtures are the most common type of mixture. This study investigates the atomisation characteristics of water–methanol mixtures injected under low pressure (0.5 MPa) into a quiescent ambience. The experiments were conducted in an open environment at 1-atm absolute pressure and 22 °C temperature. Five different compositions were tested, including pure water, pure methanol (99.9%), and mixtures with water–methanol volume ratios of 75/25, 50/50, and 25/75. Using laser shadowgraphy with long-distance microscopy, droplet size distributions were measured at four distinct locations. Under high superheat conditions, the droplet distribution was similar for all mixtures. The Sauter mean diameter (SMD) rapidly decreased for all liquids when subjected to superheated injection. This led to the conclusion that the composition of non-azeotropic substances has little significance in terms of droplet diameter at high superheat. Full article

Approaches, methods, and corresponding ground-based and air/space-borne instrumentation currently utilized for detecting, studying, and monitoring fogs (including in situ and remote sensing techniques) are summarized. Special attention is paid to the existing and some emerging methods enabling reliable assessments and quantification of basic fog parameters, such as visibility, liquid water content, droplet number/volume concentration, effective radius, and size distribution. Along with purely natural fogs and those resulting directly or indirectly from industrial, combustive, or other human activities (smog, chemical fogs), entirely artificially created fogs are also subject to consideration in this study. Systems and apparatuses for the generation and control of artificial fogs are presented and discussed in terms of operational principles, design, and applicability. Methods and devices for fog water collection/harvesting are presented in view of their importance for solving the lack of water problem in dry and desert regions. Some other actual and potential applications of natural and artificial fogs are summarized and discussed related to air freshening or cleaning from chemicals and radioactive aerosols, fire extinguishing, nebulized therapies in medicine, spray coating of tablets or material surfaces, aeroponic agriculture, dust-proof coatings, etc. Full article

Curcumin is a natural bioactive compound with demonstrated anticancer activity. However, its poor aqueous solubility and limited bioavailability constrain its therapeutic utility. This study formulated nanoemulsions using marine (salmon oil) and plant (rapeseed oil) lipids to enhance the solubility and delivery of curcumin. The fatty acid profiles and lipid class distributions of both lipid sources were characterized. The resulting nanoemulsions prepared from salmon and rapeseed oils exhibited mean droplet diameters of approximately 170 nm and 220 nm, respectively, and remained physically stable for 30 days at 25 °C. Notably, curcumin-loaded nanoemulsions displayed smaller droplet sizes than their unloaded counterparts, suggesting strong curcumin–lecithin interactions. In vitro cytotoxicity assays demonstrated that the curcumin-loaded nanoemulsions significantly reduced the proliferation of MCF-7 human breast cancer cells (p < 0.001). Collectively, these findings indicate that lipid-based nanoemulsions represent a promising delivery platform for curcumin in the context of breast cancer therapy. Full article

As global efforts to combat climate change and promote sustainable development intensify, PODEn, as an innovative type of clean, sustainable fuel, has gained growing attention for its potential to support eco-friendly energy transitions, especially concerning the spray characteristics of its blended fuels. Environmental conditions are crucial in the fuel spraying process, which is essential for optimizing combustion efficiency and reducing emissions—key elements of sustainable energy use and climate action. In this study, the parameters of spray morphology, droplet size distribution, and velocity were accurately measured using a constant-volume combustor and high-speed photography. The results demonstrate that as ambient pressure increases, both the spray cone angle and boundary gas entrainment volume increase, while the spray penetration distance and spray volume decrease. These changes, driven by pressure differences and variations in gas density that influence droplet movement and fragmentation, are critical for optimizing fuel injection strategies to enhance combustion efficiency and reduce environmental impact. This aligns closely with the Sustainable Development Goals focused on clean energy, responsible consumption, and climate mitigation. Conversely, as ambient temperature rises, the penetration distance and spray volume increase, whereas the entrainment volume decreases and the spray cone angle narrows. This phenomenon results from the combined effects of temperature on gas density, viscosity, evaporation rate, and convective flow, underscoring the need for adaptive engine designs that leverage these characteristics to improve fuel efficiency and reduce carbon emissions—an essential step toward sustainable development in the energy and automotive sectors. Full article

This study investigates the apparent surface-active and emulsifying behaviour of raw Albizia amara (AA) powder suspended in water, reflecting its traditional mode of use. AA suspensions (0.1–1% w/v) were prepared without extraction and evaluated for apparent surface tension, droplet size distribution, emulsification capacity, and emulsion stability. Increasing AA concentration reduced apparent surface tension from 57.13 ± 2.17 mN/m to 48.9 ± 0.06 mN/m, plateauing at higher concentrations. Both blending and high-shear mixing produced oil-in-water emulsions. Blending generated smaller initial droplets (1–10 µm), whilst high-shear mixing produced more uniform distributions (d₅₀ = 31.23 ± 0.95 µm). Emulsion capacity and stability increased with AA concentration, reaching 95.19 ± 3.39% and 89.81 ± 0.02% at 0.8% AA. As the system contains undissolved plant material, all measurements represent the apparent behaviour of a heterogeneous suspension. The specific molecular contributors to surface activity cannot be identified within this study. These findings provide a baseline physicochemical assessment of raw AA powder and support future work involving extraction, purification, and chemical characterisation to establish the mechanisms underlying its surface-active properties. Full article

Sunflower meal represents a protein- and fiber-rich by-product of the oil industry with potential application as a natural stabilizer in food emulsions. Building upon previous findings that emphasized the role of protein content in emulsion stability, the present study further investigated the combined effect of protein level and particle size distribution of sunflower meal fractions on the formation and stability of oil-in-water emulsions. Two sets of sunflower meal fractions were prepared from finely milled material, fractionated, and blended in controlled proportions to obtain four protein-enriched (30 ± 1%) and four cellulose-rich (15 ± 1%) fractions, each defined by particle size ranges of 250/200, 200/125, 125/100, and <100 µm. Emulsion stability was evaluated through droplet size analysis, zeta potential measurements, and creaming index determination during seven days of storage. The results demonstrated that both protein content and particle size significantly affected the emulsifying and stabilizing behavior of sunflower meal fractions. For the low-protein group (15%), larger particle sizes (250/200 µm) yielded smaller emulsion droplets (D[4.3] = 66.03 µm) and higher zeta potential values (−15.53 mV), while in the high-protein group (30%), droplet size distribution was more uniform (D[4.3] from 72.13 to 76.29 µm). During seven days of storage, all emulsions exhibited a gradual increase in creaming index, followed by partial stabilization at later time points. Emulsions prepared with sunflower meal fractions of higher-protein content showed consistently lower creaming index values, indicating improved physical stability throughout storage. Overall, the study confirmed that the interplay between composition (protein level) and physical structure (particle size) governs the emulsification efficiency of sunflower meal fractions, providing insights for their potential application as plant-based stabilizers in food systems. Full article

Background/Objectives: Cannabidiol (CBD) is a non-psychoactive compound found in the Cannabis sativa plant. Due to its broad therapeutic potential, CBD is often incorporated into various pharmaceutical formulations. This study aimed to evaluate homogenous (oil-based) and heterogeneous (emulsion-based) liquid preparations of CBD using different fatty oils and provide a comprehensive comparative framework for the development of stable liquid dosage forms of cannabidiol (CBD), with direct applications in pharmaceutical formulations. Methods: The oils and emulsions were qualitatively analysed to assess their stability and suitability as CBD carriers. Ultraviolet (UV) spectrophotometry and High-Performance Liquid Chromatography (HPLC) were employed for quantifying CBD in the formulations and also characterising them in terms of product quality. Results: The results indicated that sunflower oil is the most stable and analytically compatible matrix, with CBD recovery close to 100% and minimal degradation over time. Conversely, linseed and pumpkin seed oils exhibited significant analytical interference and oxidative instability. Oil-in-water emulsions prepared with a 4% Tween 80/Span 80 mixture demonstrated optimal physical stability and droplet size distribution. Conclusions: Overall, both formulations can be regarded as suitable pharmaceutical carriers for CBD delivery. Full article

This article focuses on the oil–water emulsification problem during steam injection in heavy oil thermal recovery. Emulsions were prepared through one-dimensional flow experiments, and key parameters including the inversion point water cut and micro-morphological characteristics (particle size and distribution range) of the emulsions were systematically measured under varied conditions (temperature: 150–360 °C; salinity: 0–7500 mg/L; water cut: 10.07–72.22%). By analyzing the experimental data, the emulsification mechanism and influencing rules were revealed: under the combined conditions of high temperature (150–360 °C), high salinity (up to 7500 mg/L), and low water cut (10.07–19.35%), crude oil and formation water form oil-in-water emulsions under the shear action of porous media. During this process, active substances in crude oil react with inorganic salts in formation water to generate natural surfactants, which reduce the oil–water interfacial tension and enhance emulsion stability, enabling the emulsion to maintain stability even at a high water cut of up to 72.22%, with particle sizes ranging from 1 μm to 350 μm and distribution spans varying from 4 μm to 50 μm. The formation of such emulsions leads to a significant increase in viscosity, adversely affecting oil recovery. In production practice, it is recommended to add chemical agents during the early stage of steam huff and puff development (water cut: 10.07–37.50%). This measure aims to destroy the oil–water liquid film, promote water droplet coalescence (narrowing the particle size distribution span), and facilitate emulsion breaking and phase inversion, thereby effectively mitigating the adverse impacts of oil–water emulsions and improving heavy oil recovery efficiency. Full article

This study investigates the potential of an undervalued cephalopod species, Eledone moschata, for producing a freeze-dried protein concentrate via acid solubilisation and isoelectric precipitation. Although nutritionally rich, the processing route significantly affected the aggregation state of the recovered proteins, as demonstrated by differential scanning calorimetry (DSC) and SDS–PAGE electrophoresis. We systematically examined pretreatments of the lyophilised protein concentrate (PC) by dispersing it across a pH range (2–10) and applying ultrasonication (US), characterising the resulting aggregates in terms of protein solubility, surface hydrophobicity, dynamic light scattering (DLS), and ζ-potential. Subsequently, ultrasound-treated protein dispersions at different pH values were used to produce protein–quercetin nanoparticles (PQ), which were analysed for particle size (DLS), yield, and quercetin entrapment efficiency. PQ dispersions at pH 2, 4, and 7 were evaluated as stabilising agents in US-treated sunflower oil emulsions containing 10% oil and were characterised by rheological properties, microstructure, and DLS particle sizing. Confocal laser scanning microscopy (CLSM) revealed that nanoparticles at pH 2 produced small, uniformly distributed fat droplets with a particle diameter of 1.5 μm. This study provides insights into how processing conditions modulate the structural and interfacial behaviour of cephalopod proteins and highlights their potential application in designing low-fat, fluid emulsions for innovative food formulations. Full article

This study systematically investigates the effects of enzyme type (Alcalase, Trypsin, Protamex) on the properties of rice peptide nanoparticles (RPNs) and their efficacy in stabilizing high internal phase emulsions (HIPEs). RPNs prepared with Alcalase (RPNs-alc) exhibited the smallest particle size (≈379.6 nm), a uniform unimodal distribution, the highest content of hydrophobic amino acid, and the strongest DPPH (2,2-Diphenyl-1-picrylhydrazyl) radical scavenging activity (57.32%). In contrast, RPNs from Protamex (RPNs-pro) showed larger, heterogeneous particles with a bimodal distribution and lower antioxidant capacity. Interfacial characterization revealed that RPNs-alc had a superior three-phase contact angle, indicating enhanced interfacial activity. Structural stability analysis confirmed that hydrophobic interactions and hydrogen bonds are the primary forces maintaining all RPNs. Consequently, HIPEs stabilized by RPNs-alc and RPNs-typ displayed solid-like behavior and a regular network microstructure, leading to exceptional physical stability. Conversely, RPNs-pro led to unstable HIPEs with non-uniform droplets and interfacial aggregation, promoting droplet flocculation. These findings demonstrate that enzyme selection critically determines the functional properties of RPNs, with Alcalase-derived RPNs being the most effective bifunctional particles, offering a viable pathway for valorizing proteolytic by-products in fabricating stable, antioxidant-rich Pickering emulsions. Full article

Urea production plays a crucial part in the worldwide agricultural economy, providing a primary supply of nitrogen for fertilizers. For storage and transport, urea is synthesized in granular form, and the prilling technology is frequently employed. In this technique, the hot liquid feed passes through an atomizer to produce small droplets, which then fall along the high tower. During the falling process, the liquid droplets gradually become solid because the internal energy is removed by the cooling air, which flows upward from the bottom. Typically, three consecutive thermal phases are analyzed for the solidification process: the liquid droplet cooling, solidification when the surface reaches freezing point, and the solid particle cooling. In this paper, the temperature distribution across the radius of the urea particles was analyzed using a heat transfer equation, which is considered a two-phase Stefan problem. The system of partial differential equations is solved numerically using the finite difference method and the enthalpy method. The temperature of the cooling air at various heights of the tower and the degree of solidification of different particle sizes were estimated and compared with data obtained from the urea factory to assess their reliability. The validation demonstrated a strong correlation between the model estimates and the real plant observations. Full article

The present study investigates the influence of atomizing air-to-liquid mass ratio (ALR) on the near-field spray characteristics and stability of a novel twin-fluid injector that integrates bubble-bursting for primary atomization and shear-induced secondary atomization. Unlike conventional injectors, the novel design generates ultra-fine sprays at the exit with low sensitivity to liquid properties. The previous version improved secondary atomization even for highly viscous liquids, showing strong potential in hydrogel-based fire suppression. The current design improves primary atomization, leading to more stable and finer sprays. The near-field spray characteristics are quantified using a high-speed shadowgraph across ALRs ranging from 1.25 to 2.00. This study found that stable and finely atomized sprays are produced across all the tested ALRs. Increasing ALR reduces droplet size, while the spray is the widest at 1.25. Sauter Mean Diameter (SMD) contours show larger droplets at the edges and smaller ones toward the center, with ALR 2.00 yielding the most uniform size distribution. As per the atomization efficiency, ALR of 1.25 shows the best performance. Overall, an optimum ALR of 1.75 is identified, offering balanced droplet size distribution, stability, and atomization efficiency, making the injector potentially suitable for fire suppression and liquid-fueled gas turbines requiring high stability and fuel flexibility. Full article

Precise regulation of micropipette outlet flow is critical for fluorescence imaging in vivo micromanipulations. In such procedures, a micropipette with a micro-sized opening is driven by gas pressure to deliver internal solution into the in vivo environment. The outlet flow rate needs to be precisely regulated to ensure a uniform and stable fluorescence distribution. However, conventional manual pressure injection methods face inherent limitations, including insufficient precision and poor reproducibility. Existing commercial microinjection systems lack a quantitative relationship between pressure and flow rate. And existing calibration methods in the field of microfluidics suffer from a limited flow-rate measurement resolution, constraining the establishment of a precise pressure–flow quantitative relationship. To address these challenges, we developed a closed-loop pressure regulation system with 1 Pa-level control resolution and established a quantitative calibration of the pressure–flow relationship using a droplet-based method. The calibration revealed a linear relationship with a mean pressure–flow gain of 4.846 $\times {10}^{-17}{\mathrm{m}}^3·{\mathrm{s}}^{-1}·{\mathrm{P}\mathrm{a}}^{-1}$ (R² > 0.99). Validation results demonstrated that the system achieved the target outlet flow rate with a flow control error less than 10 fL/s. Finally, the application results in brain-slice environment confirmed its capability to maintain stable fluorescence imaging, with fluorescence intensity fluctuations around 1.3%. These results demonstrated that the proposed approach provides stable, precise, and reproducible flow regulation under physiologically relevant conditions, thereby offering a valuable tool for in vivo micromanipulation and detection. Full article

This study investigated the relationships between emulsion droplet triacylglycerol (TAG) crystallinity and colloidal acid stability on in vitro digestion microstructure, lipolysis, and docosahexaenoic acid (DHA) bioaccessibility. Oil-in-water (o/w) nanoemulsions (20 wt%) composed of 50/50 DHA-rich algal oil with either palm stearin (PS) or olein (PO), and either acid-stable Tween 80 (2.0 wt%; AS) or acid-unstable soy lecithin (2.2 wt%; AU) were fast or slow cooled to 37 °C after microfluidization. Similar particle size distributions and D_3,2 (~131–142 nm) and D_4,3 (~208–239 nm) values were achieved. All emulsions were highly electronegative (~−45–70 mV) and differences (p < 0.05) were due to emulsifier type, as expected, and cooling rate. Next, emulsions were subjected to INFOGEST in vitro digestion for analysis of intestinal lipolysis by free fatty acid titration and DHA bioaccessibility. As expected, AU emulsions flocculated, forming larger aggregates during the gastric phase. Slower lipolysis was observed for the AU emulsions (p < 0.05), attributed to gastric phase aggregation, and lower 2 h lipolysis was observed for the PS emulsions (~74–77%) based on the presence of crystallinity. DHA bioaccessibility was high (~57–88%), especially for the AS emulsions (p < 0.05). Therefore, emulsion colloidal acid stability and TAG physical state significantly impacted emulsion gastric microstructure, digestion, and bioaccessibility. Full article