Larger Droplet Size Research Articles

Effects of droplet dynamical behavior in flow channel of proton exchange membrane fuel cell under vibration conditions on cell performance

Proton exchange membrane fuel cells are subjected to severe vibration in aerospace applications. Understanding the droplet transport characteristics in the flow channelunder vibration conditions is essential for improving cell performance. However, the underlying patterns and mechanisms of the vibration effects on cell performance and its internal water transport remain unclear, and there is a lack of improvement methods for drainage under vibration conditions. This study experimentally investigates the effect of vibration on cell performance. Experimental results indicate that vibration predominantly affects cell performance through its modulation of water transport. Therefore, the droplet dynamic behavior in the flow channel is further studied using the volume of fluid method. The results indicate that vibrations can enhance the average performance of the fuel cells, with the largest increase of 8.30 %. This is attributed to vibrations promoting the detachment of droplets from the gas diffusion layer surface and reducing the water coverage ratio on said surface. Under conditions of low gas velocity, high surface hydrophobicity, and large droplet size, droplets exhibited oscillatory and jumping behavior in the flow channel due to vibration, resulting in the largest 53.5 % increase in peak water coverage ratio on the gas diffusion layer surface compared to no-vibration conditions. Furthermore, enhancing the hydrophobicity of the gas diffusion layer and the hydrophilicity of the channel walls promotes droplet detachment and discharge compared to no-vibration, as well as contributing to the improvement of vibration effects on the drainage process.

Microphysical characteristics of torrential predecessor rain events over the Yangtze River Delta Area and the related tropical cyclones

The precipitation structures and microphysical characteristics of predecessor rain events (PREs) over the Yangtze River Delta area and related tropical cyclones (TCs) from 2014 to 2019 were investigated using Dual-frequency Precipitation radar data from Global Precipitation Measurement (GPM) for drop size distributions (DSDs). Results showed that the total mean rain rate of PREs was larger than that of TCs, primarily due to higher convective and stratiform rain rates, with enhanced fractional coverage of convective rain in PREs. Examination of microphysical characteristics revealed that a greater quantity of small-sized droplets and a smaller quantity of medium- as well as large-sized droplets contributed towards PREs in comparison with TCs. The conclusion still holds when partitioning DSDs based on different precipitation rate categories. Further investigation of DSDs using gamma functions illustrated that precipitation in PREs had lower average mass-weighted diameters (Dm) and enhanced normalized number concentration (Nw) compared with TCs; partitioning precipitation into convective and stratiform components illustrated a larger Dm and lower Nw in TCs than PREs. The analysis of microphysical and thermodynamical processes using the reanalysis data indicates that relatively intense convective activity with drier conditions may be favorable to enhancing raindrop growth through collision-coalescence processes, as a result of larger Dm in TCs than PREs. The empirical relations (Z–R algorithms) applied in different rain regimes (stratiform, convective, and total PREs) revealed significant diversities, relying on weather conditions and geographical locations. Plain language summaryThe Yangtze River Delta area is an important economic belt in China. Under climate change, observed frequent occurrences of weather extremes of heavy rainfall and tropical cyclones (TCs) exert adverse effects on economic development in this region. Thus, a deep understanding of the mechanism of TCs torrential rainfall in the Yangtze River Delta area is urgently necessary. In this study, we investigated the precipitation patterns and microphysical characteristics of predecessor rain events (PREs) in the Yangtze River Delta region, and their association with TCs in the South China Sea-Western North Pacific Ocean (SCS-WNPO) area from 2014 to 2019. We found that PREs had a higher total mean precipitation rate than TCs. Further examination using gamma functions demonstrated that PREs exhibited lower average mass-weighted diameters (Dm) and higher normalized intercept parameters (Nw) than TCs. This pattern persisted when distinguishing between convective and stratiform precipitation components. We believe that our study makes a significant contribution to the literature because these results provide valuable insights into the distinct precipitation characteristics of PREs and TCs in the study region and contribute to a better understanding of tropical cyclone-related rainfall patterns, and act as a scientific basis for disaster mitigation.

Revealing nanoscale structure and interfaces of protein and polymer condensates via cryo-electron microscopy.

Liquid-liquid phase separation (LLPS) is a ubiquitous demixing phenomenon observed in various molecular solutions, including in polymer and protein solutions. Demixing of solutions results in condensed, phase separated droplets which exhibit a range of liquid-like properties driven by transient intermolecular interactions. Understanding the organization within these condensates is crucial for deciphering their material properties and functions. This study explores the distinct nanoscale networks and interfaces in the condensate samples using a modified cryo-electron microscopy (cryo-EM) method. The method involves initiating condensate formation on electron microscopy grids to limit droplet growth as large droplet sizes are not ideal for cryo-EM imaging. The versatility of this method is demonstrated by imaging three different classes of condensates. We further investigate the condensate structures using cryo-electron tomography which provides 3D reconstructions, uncovering porous internal structures, unique core-shell morphologies, and inhomogeneities within the nanoscale organization of protein condensates. Comparison with dry-state transmission electron microscopy emphasizes the importance of preserving the hydrated structure of condensates for accurate structural analysis. We correlate the internal structure of protein condensates with their amino acid sequences and material properties by performing viscosity measurements that support that more viscous condensates exhibit denser internal assemblies. Our findings contribute to a comprehensive understanding of nanoscale condensate structure and its material properties. Our approach here provides a versatile tool for exploring various phase-separated systems and their nanoscale structures for future studies.

Unraveling the impact of starch granule-associated proteins on the emulsifying ability of quinoa starch granules at multiple scales

Total starch granule-associated proteins (tGAP), including granule-channel (GCP) and granule-surface proteins (GSP), alter the physicochemical properties of starches. Quinoa starch (QS) acts as an effective emulsifier in Pickering emulsion. However, the correlation between the tGAP and the emulsifying capacity of QS at different scales remains unclear. Herein, GCP and tGAP were selectively removed from QS, namely QS-C and QS-A. Results indicated that the loss of tGAP increased the water permeability and hydrophilicity of the starch particles. Mesoscopically, removing tGAP decreased the diffusion rate and interfacial viscous modulus. Particularly, GSP had a more profound impact on the interfacial modulus than GCP. Microscopically and macroscopically, the loss of tGAP endowed QS with weakened emulsifying ability in terms of emulsions with larger droplet size and diminished rheological properties. Collectively, this work demonstrated that tGAP played an important role in the structural and interfacial properties of QS molecules and the stability of QS-stabilized emulsions.

Effects of a 3D-Printed Atomizer Component on Fuel-Spray and Flame Characteristics of a Jet-Stabilized Compact Gas Turbine Combustor Fed With Liquid Fuels

Abstract In this work, the effects of replacing an atomizer component of a confined jet-stabilized gas turbine combustor with a 3D-printed part have been studied. The part is called airblast, and it serves as a wall that collects and flows liquid droplets for a secondary atomization. Therefore, the liquid-surface interaction on the rough surface of the 3D-printed part was of interest. The combustor was operated under various conditions with either a conventionally machined airblast or the 3D-printed airblast. Flames with two liquid fuels were studied for fuel flexibility, and the position of a primary fuel injection was varied to study the influence of the liquid-surface interaction length. Load flexibility was investigated with air jet velocity settings, and flame equivalence ratios of ϕ = 0.8 and 1.0 were tested. Shadowgraphy-based particle tracking analyses presented a reduced atomization performance with the 3D-printed airblast, showing large droplet size distributions. However, no significant change in the combustor performance was observed from OH* chemiluminescence images and emission data, which confirms the versatility of the combustor and assures the compatibility of 3D-printed components with the combustor of this study.

Tailored edible 3D porous scaffolds constructed by Pickering emulgel templating for cell-cultured fish meat

Cell-cultured fish meat have emerged as an innovative approach to resolving the issues in response to consumer demand. Food-grade scaffolds, which not only serve as the “comfortable home” for stem cells but also endow the final product with meat-like texture, play a vital role in the construction of cell-cultured fish meat. In this study, pea protein, an abundant and inexpensive plant protein, is used to construct edible three-dimensional (3D) porous scaffolds, which exhibit desirable stem cell proliferation and differentiation performance. Our findings demonstrate that it is feasible to apply the Pickering emulgel templating combined with double-crosslinking to the preparation of cell-cultured fish meat scaffolds. The pore structure of 3D porous scaffolds can be altered by varying the emulsification parameters on demand. The Pickering emulgels with large droplet size (around 40 μm) are conducive to the formation of 3D porous scaffolds with large enough pore size for the growth of stem cells. The now available result help to explore the plant protein-derived scaffolds, provide insights into the development of Pickering emulgel-based 3D porous scaffolds and illuminate the relationship between the structural characteristics of scaffolds and the biological functions of stem cells.

Supercooled large droplet size distribution effects on airfoil icing: A numerical investigation based on a new coupled Eulerian method

Supercooled large droplets (SLDs) under natural icing conditions have the characteristics of easy deformation in motion and easy splashing on impact, and a bimodal droplet size distribution that has received less attention. The modified form of the Rosin-Rammler function was improved to achieve a more accurate nonlinear fitting of the SLD distribution curve. The droplet size distribution was divided into non-equipartition continuous multiple components. The drag source term of each component was coupled with the overall droplet size distribution, and the Eulerian equations of each component of SLDs were solved simultaneously. A new coupled Eulerian method for non-equipartition continuous multi-size droplets was proposed to simulate the impact characteristics of SLDs, and the SLD collection coefficients were validated. Effects of the ratio between the number of large and small droplet components and the number of all components on the simulation results were investigated to select a better combination based on stable convergence calculation steps and the calculation time. This new method was added to the multi-step icing numerical method, and the accuracy and robustness of the method in icing shape prediction were verified based on the freezing drizzle, median volume diameter < 40 μm (FZDZ, MVD < 40 μm) icing condition. Airfoil icing characteristics based on the bimodal and monomodal distribution were compared, and the icing shapes at the leading edge were similar. Still, the upper and lower limits of the icing shapes with the bimodal distribution were nearer to the trailing edge and the ice layer was thicker there.

Experimental study of liquid–liquid dispersion patterns in T-inlet microchannels with different junction angles

Liquid-liquid two-phase flow in T-inlet microchannels with different junction angles (θ = 30°, 60°, 90°, 120° and 150°) was investigated experimentally. Four flow regimes of the dispersed phase were identified, i.e., parallel flow, jetting, dripping and squeezing, and the distribution of flow regimes for the dispersed phase corresponding to variations in the junction angle was plotted. The consequences of varying junction angle and flow conditions in the squeezing regime on the generated droplet size were analyzed. The results indicate that low capillary number and large flow rate ratio are conducive to the formation of large-size droplets. For constant flow conditions, junction angle θ = 90° is detrimental to the formation of squeezing microdroplets. The increase in microchannel junction angle causes the droplet size to decrease until θ > 90°, where the droplet size increases with the junction angle. On the basis of experimental results, the scaling law correlation equations containing the junction angle for predicting the droplet length and droplet volume are proposed, respectively. The predicted values match well with the experimental data. The results of this work contribute to the enhancement of the monodispersity of microdroplets and the precise control over a wide range of the generated droplet size by adjusting the junction angle.

Interfacial rheological properties of pepsin-hydrolyzed lentil protein isolate at oil-water interfaces

Lentil protein isolate (LPI) was investigated for its potential as a plant protein-based emulsifier. LPI consists mainly of globulins with high molecular weights which are relatively slow to adsorb and stabilize oil-water interfaces. Smaller proteins, such as whey protein, can stabilize the interface much faster, quickly forming a viscoelastic film that slows down the rate of droplet recoalescence, leading to smaller droplets. To increase the rate of adsorption, LPI was enzymatically hydrolyzed by pepsin at 1.5% and 4.5% degree of hydrolysis (DH), to obtain small peptides. The behavior of these peptides was studied at the oil-water interface in comparison to whey protein isolate (WPI) and native lentil protein isolate (LPI). Interfacial properties were investigated using dilatational and interfacial shear rheology in the linear viscoelastic regime (LVE) and nonlinear viscoelastic regime (NLVE) and these were related to protein characteristics and emulsion formation. The 1.5% and 4.5%DH LPI showed high surface hydrophobicity, and consisted mainly of low molecular weight peptides, which contributed to faster adsorption kinetics and consequently covered the interface faster than LPI. In dilatation, the native and hydrolyzed LPI-stabilized interfaces had comparable stiffness and were clearly weaker than WPI-stabilized interfaces, which contrasts with the results in shear deformations, where the former both had higher stiffness than WPI. Both hydrolyzed LPI and WPI formed more brittle and less stretchable interfaces compared to native LPI in both dilatational and shear rheology. In emulsification tests, native LPI produces the largest droplets, and the 4.5% DH LPI and WPI have the smallest droplet size. But, bridging flocculation was observed when emulsions were prepared with both hydrolyzed LPI, which may be attributed to inter-droplet hydrophobic interactions between small polypeptides. This can be linked to an increase in the surface hydrophobicity of hydrolyzed LPI. Thus, the use of native LPI as a stabilizer in emulsion preparation is preferable over the hydrolyzed samples, despite its larger droplet size.

Application of rheology and interfacial rheology to investigate the emulsion stability of ultrasound-assisted cross-linked myofibrillar protein: Effects of oil phase types

This work was designed to illustrate the differences in the dispersed phase that affect the emulsion stability. The effect of oil types including soy oil, corn oil, rapeseed oil, sunflower oil, and flaxseed oil on the stability of the emulsion stabilized by modified MP (sonication after crosslinking treatment) was investigated. Results showed that the differences in fatty acid composition in the oil phase would affect the interaction between the oil phase and modified MP. Emulsion in the P-flaxseed group (with higher linolenic acid) showed lower TSI values, smaller protein-coated oil droplets, higher adsorbed protein content, storage modulus, and small elastic Lissajous curve area than other emulsion groups. While the P-rapeseed (with higher oleic acid) and P-sunflower (with higher linoleic acid) groups had large droplet sizes, poor emulsion stability, and rheological behavior. Correspondingly, the higher θo/w (86.97°), hf, π (21.55 mN/m), Kdiff, KR, Ed, E-π slope (3.22), and linear interfacial Lissajous plot in the P-flaxseed group indicated modified MP was preferred to adsorb on the surface of flaxseed oil to form an elastic-dominated interfacial protein film with higher deformation resistance. Furthermore, the poorer interfacial adsorption behavior and easily collapsed interfacial film further proved the poor emulsion stability of the P-rapeseed and P-sunflower groups. Therefore, differences in fatty acid compositions of oil phases impacted the interfacial adsorption characteristics of the modified MP, thereby influencing the emulsion stability.

Bionics-based design aimed at solving particulate sedimentation and engineered synthesis of large-sized energetic coated granules with improved performances

Much attention has been paid to the coating of energetic materials to improve their properties. However, the present coating technology has drawbacks, and it fails to meet the requirements of engineering applications. In this study, observation of the toad spawning process gave an idea for efficient preparation of millimeter-sized coated granules by directly using unrefined HMX. In this technique, the preparation device was cheaper and requirements were simpler. The mechanism of formation mechanism and curing of the coated granules were studied. The preparation process and its formula were continuously optimized during the exploration process. The morphologies and properties of the granules coated with different binders were studied by various techniques and the industrial productivity was evaluated. The coated granules showed regular and full morphology after optimization of the formula and were not easily deformed. Compared with unrefined HMX, the flowability was significantly improved, the mechanical sensitivity was reduced, the response time for ignition was shorter, and the flame intensity was higher. This method solved the problems of sedimentation of particulates and curing of large-sized droplets, while its high production efficiency and little wastage provided a new reference for producing large-sized high-energy coated granules for use in engineering applications.

Performance evaluation of novel plate-type condenser for an absorption/adsorption refrigeration system: Experimental and CFD study

Plate heat exchangers are widely used in many industries, such as refrigeration and air conditioning. Traditionally, the condenser in an absorption system comprises a shell and tube heat exchanger. However, we have innovatively replaced the conventional tubes with chevron plates in this system. The following variables were measured: condensation pressure (5.75–7.00 kPa), wall subcooling (0.2–1.8 °C), and channel Reynolds number (350–1400). In alignment with experimental results, the CFD simulation shows a higher condensation rate and large droplet size at the higher subcooling, and lower heat flux as the saturation pressure is decreased. Moreover, the overall heat transfer coefficient and the pressure drop of the chevron-type plate heat exchanger are increased by 1.60–5.00 times and 1.30–3.00 times, respectively, compared to the shell and tube condenser.

Interfacial Behavior and Long-Term Stability of the Emulsions Stabilized by Sugar Beet Pectin-Ca2+ Complexes with Different Cross-Linking Degrees.

Recent studies showed that sugar beet pectin exhibited more excellent emulsifying properties than traditional citrus peel pectin and apple pectin ascribed to the higher content of neutral sugar, protein, ferulic acid, and acetyl groups. It is precisely because of the extremely complex molecular structure of pectin that the emulsifying properties of the pectin-Ca2+ complex are still unclear. In this study, SBP-Ca2+ complexes with different cross-linking degrees were prepared. Subsequently, their interfacial adsorption kinetics, the resistance of interfacial films to external perturbances, and the long-term stability of the emulsions formed by these SBP-Ca2+ complexes were measured. The results indicated that the highly cross-linked SBP-Ca2+ complex exhibited slower interfacial adsorption kinetics than SBP alone. Moreover, compared with SBP alone, the oil-water interfacial film loaded by the highly cross-linked SBP-Ca2+ complex exhibited a lower elasticity and a poorer resistance to external perturbances. This resulted in a larger droplet size, a lower ζ-potential value, a larger continuous viscosity, and a worse long-term stability of the emulsion formed by the highly cross-linked SBP-Ca2+ complex. This study has very important guiding significance for deeply understanding the emulsification mechanism of the pectin-Ca2+ complex.

Microencapsulation of fish oil with brewer’s spent grain proteins: Effect of citric acid and emulsion pH

The use of brewer’s spent grain (BSG) proteins as wall material for encapsulating fish oil was investigated for the first time. This study also demonstrated the effect of citric acid (CA)-crosslinking and emulsion pH on the encapsulating ability of BSG proteins. Four different BSG microcapsules were prepared, including non-crosslinked and crosslinked BSG microcapsules at pH either above or below the isoelectric point (pI) of BSG proteins, and their performance was compared with OSA-starch. Crosslinked BSG emulsions had larger droplet size than non-crosslinked ones. The largest droplet sizes were found in emulsions where pH < pI due to some degree of protein aggregation. Encapsulation efficiency of BSG microcapsules ranged from 81 to 93%. BSG microcapsules, regardless of crosslinking, showed considerably higher oxidative stability than OSA-starch microcapsules. CA-crosslinking further enhanced their oxidative stability. The highest and the lowest oxidative stabilities among BSG microcapsules belonged to the microcapsules prepared at pH < pI, where some degree of protein aggregation occurred in the emulsions. Crosslinked BSG microcapsule prepared at pH < pI exhibited the highest oxidative stability with peroxide and thiobarbituric acid reactive substances (TBARS) values remaining in the range allowed for fresh oils even after 15 days of storage at 40 °C. It was attributed to its denser shell matrix due to CA-crosslinking and multilayer formation resulting from protein aggregation. Non-crosslinked microcapsules prepared at pH < pI represented the lowest oxidation stability among BSG microcapsules due to larger pores. The results suggest a synergistic effect of CA-crosslinking and protein aggregation, which significantly reinforced shell matrix and effectively reduced oxygen permeability.

Effect of Inulin on Rheological Properties and Emulsion Stability of a Reduced-Fat Salad Dressing.

This study is aimed at investigating the potential use of inulin in a reduced-fat salad dressing to improve its rheological properties, fat globule size distribution, and emulsion stability. The reduced-fat salad dressing, which has 50% less fat compared to the full-fat counterpart (control), was prepared with varying inulin concentrations (10, 12.5, 15, 17.5, and 20% w/w). The full-fat and reduced-fat salad dressings exhibited a non-Newtonian shear-thinning behavior. Power law model was used to describe the rheological properties. Results showed that the flow behavior index (n) and consistency coefficient (K) were greatly affected by the concentration of inulin. A greater pseudoplasticity and apparent viscosity of the reduced-fat samples were achieved with a higher concentration of inulin. Oscillatory tests showed that the storage modulus (G') and loss modulus (G ″) values increased with increasing inulin concentration. All samples displayed characteristics of a viscoelastic solid, as evidenced by a greater G' than G ″. Regarding the size distribution of the oil droplets, the reduced-fat salad dressing containing a higher inulin content was observed to have a larger droplet size. All reduced-fat samples, similar to the full-fat counterparts, exhibited stability with no cream separation over one month of storage at 4°C, as determined by visual observation. Additionally, the reduced-fat salad dressings supplemented with 17.5 and 20% inulin exhibited stability against cream separation, comparable to the full-fat counterpart (p > 0.05), as measured by the thermal stress test (80°C for 30 min) with centrifugation. The sensory acceptance scores for reduced-fat salad dressing with 15 and 17.5% inulin, ranging from approximately 6.28 to 7.63 on a 9-point hedonic scale for all evaluated attributes (appearance, color, aroma, texture, taste, and overall acceptability), were not significantly different from those of the full-fat counterpart (p > 0.05). This study demonstrated that inulin may be a suitable ingredient in reduced-fat salad dressings.

ЗАСТОСУВАННЯ СУЧАСНИХ РОБОЧИХ ОРГАНІВ ДОЩУВАЛЬНИХ МАШИН ЯК ЗАСІБ ПОКРАЩЕННЯ ЯКОСТІ ДОЩУ ТА МІНІМІЗАЦІЇ ЙОГО ВПЛИВУ НА ФІЗИЧНІ ВЛАСТИВОСТІ ТА СТРУКТУРУ ҐРУНТУ

The article presents the results of research on the impact of qualitative and structural characteristics of artificial rain created by sprinklers and ways and means of minimizing its negative impact on the soil by using modern low-pressure sprinklers. The purpose of the research is to study the design features of different types of sprinklers, and the practice and effectiveness of their use in the conditions of irrigated agriculture in Ukraine. Methods and materials. The study of structural and technological features of the working bodies of sprinklers, the practice of their application, and the determination of the main indicators of the quality of the generated rain were carried out in the economic conditions of their operation during the tests. When assessing the quality of work, the intensity of rain, the average diameter of the drops created, the coefficient of effective watering along the sprinkler belt of the tested machines, the specific power of rain, and the comparison of these indicators when using different types of sprinklers were determined according to the standardized methods of the relevant regulatory documents: SOU 74.3-37-152, DSTU ISO 11545. Results. Modern sprinklers are equipped with highly efficient sprinklers with a large capture area and low energy impact on the soil, taking into account all components of the impact of the quality and structure of artificial rain. At low-pressure values, such sprinklers provide a low intensity of rain due to a large spray area, good uniformity, and optimal droplet sizes. The use of these working bodies provided a solution to the problem of minimizing the negative impact of irrigation on the ecology of the environment. The high efficiency of the use of modern sprinklers was confirmed by tests of machines equipped with similar working bodies, according to the results of which a decrease in the intensity of rain and its energy impact on the soil was noted due to the low-working pressure, large coverage area, a nominal spectrum of droplet size and speed of their fall. Conclusions. The use of low-pressure sprinklers makes it possible to reduce the energetic impact of rain on the soil, which ensures the preservation of its structure and reduction of erosion processes, ensures high uniformity of irrigation at low pressure in the irrigation network, reduces moisture loss from the influence of air temperature and wind, and irrigation costs due to the reduction of pressure in irrigation network. Keywords. sprinklers, intensity of rain, size of drops, sprinklers, uniformity of watering, water erosion of the soil, pressure.

In situ and real-time interfacial rheology and sum frequency generation studies of pale, soft, and exudative-like myosin's hydrophobic interface behavior explained by energy landscapes theory

To disclose the interfacial behavior of proteins, in situ and in real-time degree information to which proteins maintain their original conformation at hydrophobic interfaces is critical. Based on energy landscapes theory, surface hydrophobicity and conformation flexibility in control (native) and pale, soft, and exudative-like (PSE-like (pre-denatured)) myosin at the hydrophobic interface was investigated. When the myosin concentration was lower than the keypoint concentration (Control: 0.05 mg/mL, PSE: 0.1 mg/mL), increasing myosin concentration improved the interfacial diffusion rate (Kdiff) and penetration rate (Kp) at the oil/water interface. Although PSE myosin was easily adsorbed at the interface due to high surface hydrophobicity, hydrophobic aggregation and poor conformation flexibility led to low Kdiff and rearrangement rate (Kr), respectively. According to the sum frequency generation (SFG) results, the proportion of the lost α-helix structures in PSE myosin (from 18.93% to 16.79%) was lower than that in control myosin (from 86.64% to 74.18%) after 3 h at the lipid/water surface in situ and in real-time. The difference in interfacial behaviors between control and PSE myosin may be rely on energy barriers from metastable PSE myosin and different unfolding pathways on energy landscapes between two proteins, supported by SFG. Macroscopically, confocal laser scanning microscopy and backscattering (BS) profiles results showed that unstable PSE myosin-soybean oil emulsion with poor interfacial behavior had a larger droplet size and a higher negative peak of ΔBS than control emulsion, respectively. These results have crucial implications for the regulation of interfacial behavior and emulsion characteristics in proteins with varied denatured states.

Variability and properties of liquid-dominated clouds over the ice-free and sea-ice-covered Arctic Ocean

Abstract. Due to their potential to either warm or cool the surface, liquid-phase clouds and their interaction with the ice-free and sea-ice-covered ocean largely determine the energy budget and surface temperature in the Arctic. Here, we use airborne measurements of solar spectral cloud reflectivity obtained during the Arctic CLoud Observations Using airborne measurements during polar Day (ACLOUD) campaign in summer 2017 and the Arctic Amplification: FLUXes in the Cloudy Atmospheric Boundary Layer (AFLUX) campaign in spring 2019 in the vicinity of Svalbard to retrieve microphysical properties of liquid-phase clouds. The retrieval was tailored to provide consistent results over sea-ice and open-ocean surfaces. Clouds including ice crystals that significantly bias the retrieval results were filtered from the analysis. A comparison with in situ measurements shows good agreement with the retrieved effective radii and an overestimation of the liquid water path and reduced agreement for boundary-layer clouds with varying fractions of ice water content. Considering these limitations, retrieved microphysical properties of clouds observed over the ice-free ocean and sea ice in spring and early summer in the Arctic are compared. In early summer, the liquid-phase clouds have a larger median effective radius (9.5 µm), optical thickness (11.8) and effective liquid water path (72.3 g m−2) compared to spring conditions (8.7 µm, 8.3 and 51.8 g m−2, respectively). The results show larger cloud droplets over the ice-free Arctic Ocean compared to sea ice in spring and early summer caused mainly by the temperature differences in the surfaces and related convection processes. Due to their larger droplet sizes, the liquid clouds over the ice-free ocean have slightly reduced optical thicknesses and lower liquid water contents compared to the sea-ice surface conditions. The comprehensive dataset on microphysical properties of Arctic liquid-phase clouds is publicly available and could, e.g., help to constrain models or be used to investigate effects of liquid-phase clouds on the radiation budget.

Influence of varying oil phase volume fractions on the characteristics of flaxseed-derived diglyceride-based Pickering emulsions stabilized by modified soy protein isolate

This research aimed to create Pickering emulsions using modified soy protein isolate (SPI) as a stabilizer and flaxseed-derived diglyceride (DAG) as an oil phase. The SPI was modified through a process involving both heating and ultrasound treatment. The result indicated that the droplet size of emulsions increased with the increase in oil content (p < 0.05). For instance, the largest droplet size (23 µm) was observed at an oil-to-SPI dispersion ratio of 4:1 ratio (φ = 80), whereas the smallest droplet size (6.39 µm) was noticed at the 1:4 ratio. During the 7-day storage period, the emulsions with a 4:1 ratio (φ = 80) showed the lowest droplet size increase (from 23 µm to 25.58 µm). In contrast, the emulsions with a 1:1 ratio displayed the highest increase (from 19.39 µm to 74.29 µm). Creaming index results revealed that emulsions with a 4:1 ratio (φ = 80) showed no signs of creaming and phase separation than all other treatments (p < 0.05). Backscattering fluctuations (ΔBS) and turbiscan stability index (TSI) showed that emulsions with 4:1, 2:1, and 1:1 oil-to-SPI dispersion ratios had consistent ΔBS curves with higher and TSI curves with lower values. Optical microscopy, confocal laser scanning, and cryo-scanning electron microscopy revealed that emulsions with oil-to-SPI dispersion ratios of 4:1 and 2:1 had well-organized structures with no visible coalescence. Macromorphological and microrheological investigations demonstrated that emulsions with 80% oil content had the highest viscosity, both moduli, elasticity index, macroscopic viscosity index, and the lowest fluidity index and solid–liquid balance values. Moreover, these emulsions were more resistant to centrifugation and storage environments. In conclusion, the study determined that flaxseed-derived DAG-based high internal phase Pickering emulsions (φ = 80) had superior stability, improved viscoelasticity, and better rheological properties.

Modulating the properties of myofibrillar proteins-stabilized high internal phase emulsions using chitosan for enhanced 3D-printed foods

The 3D printability of myofibrillar proteins (MP)-based high internal phase emulsions (HIPEs) is a concern. This study investigated the influence of chitosan (CS) concentrations (0–1.5 wt%) on the physicochemical properties, microstructure, rheological properties, and stability of MP-based HIPEs. Results showed that the interaction between MP and CS efficiently modulated the formation of HIPEs by modifying interfacial tension and network structure. The addition of CS (≤ 0.9 wt%, especially at 0.6 wt%) acted as a spatial barrier, filling the network between droplets, which triggered electrostatic repulsion between CS and MP particles, enhancing MP's interfacial adsorption capacity. Consequently, droplet sizes decreased, emulsion stability increased, and HIPEs became more stable during freeze-thaw cycles, centrifugation, and heat treatment. The rheological analysis further demonstrated that the low energy storage modulus (G', 330.7 Pa) of MP-based HIPEs exhibited sagging and deformation during the self-supporting phase. However, adding CS (0.6 wt%) significantly increased the G' (1034 Pa) of MP-based HIPEs. Conversely, increasing viscosity and spatial resistance attributed to CS (> 0.9 wt%) noticeably caused larger droplet sizes, thereby diminishing the printability of MP-based HIPEs. These findings provide a promising strategy for developing high-performance and consumer-satisfaction 3D printing inks using MP-stabilized HIPEs.