The Rehydration Ability of Whey Ingredients

The purpose of this research was to studythe ability of whey protein concentrates (WPC) and whey permeate produced with ultrafiltration of cheese whey to rehydrate. The products studied were cheese whey concentrate witha PDM percentage of 80% (WPC-80), and cheese whey permeate, both produced under the conditions of the PJSC Dairy “Voronezhsky”.WPC-80 and the whey permeate dissolution processes were studied using microscopy. Water-impermeable hydrophobic layers were formed at the boundary, preventing water penetration into dry particles. The result was a higher dissolution timeforWPC-80 compared with whey permeate. When WPC-80 came into contact with water,it initially formed an obtuse wetting angle with a slow change over time. Whey permeate reached the equilibrium wetting angle more quickly. Quickreconditioning of WPC moisture content required avoiding capillary penetration of water, which created a turbulent liquid flow. The application of these ingredients in different food industry areas can reduce the costs for finished products, contribute to cost-effectiveness, increase the total production, and reduce environmental risks. Keywords: whey protein concentrate, whey permeate powder, water-wetting, dissolution

Temperature and curvature-dependent thermal interface conductance between nanoscale-gold and water from molecular simulation

Plasmonic gold nanoparticles (AuNPs) can convert laser irradiation into thermal energy and act as nano heaters in avariety of applications. Although the AuNP-water interface is an essential part of the plasmonic heating process,there is a lack of mechanistic understanding of how interface curvature and the heating itself impact interfacial heattransfer. Here, we report atomistic molecular dynamics simulations that investigate heat transfer through nanoscalegold-water interfaces. We confirmed that interfacial heat transfer is an important part of AuNP heat dissipation inAuNPs with diameter less than 100 nm, particularly for small particles with diameter≤10 nm. To account forvariations in the gold-water interaction strength reported in the literature, and to implicitly account for differentsurface functionalizations, we modeled a moderate and a poor AuNP-water wetting scenario. We found that thethermal interface conductance increases linearly with interface curvature regardless of the gold wettability, while itincreases non-linearly, or remains constant, with the applied heat flux under different wetting conditions. Our analysissuggests the curvature dependence of the interface conductance is due to the changes in interfacial water adsorption,while the temperature dependence is caused by heat-induced shifts in the distribution of water vibrational states.Our study advances the current understanding of interface thermal conductance for a broad range of applications.

Full-scale Fire Suppression Tests to Analyze the Effectiveness of Existing Lithium-ion Battery Fire Response Procedures for Electric Vehicle Fires

The number of registered eco-friendly vehicles has exceeded a million, and their market share has expanded. In this study, the effectiveness of existing fire response procedures for lithium-ion batteries, which are widely used in eco-friendly vehicles, was investigated by using water-based extinguishing agents, fire blankets, and flood barriers. Water, wetting agents, and foaming agents were sprayed on the underside of battery packs. A temperature decrease rate of ~0.08 ℃ was measured, and no significant difference was observed between the extinguishing agents. Continuous thermal runaway occurred when a fire blanket was applied, and the temperature inside the damaged battery pack rapidly decreased after water permeated its cracks. Quantitative analysis of fire suppression methods can provide information toward the development of practical fire incident response plans for electric vehicles.

Superhydrophilicity of $\alpha$-Alumina Surfaces Results from Tight Binding of Interfacial Waters to Specific Aluminols

Understanding the microscopic driving force of water wetting is challenging and important for design of materials. In this work, we investigate, using classical molecular dynamics simulations, the water/$\alpha$-alumina (0001) and ($11\overline{2}0$) interfaces chosen for their chemical and physical differences. There is only one type of aluminol group on the nominally flat (0001) surface but three types on the microscopically rougher ($11\overline{2}0$) surface. We find that both surfaces are completely wet, consistent with contact angles of zero. Moreover, the work required to remove water from a nanoscale volume at the interface is larger for the (0001) surface than the ($11\overline{2}0$) surface, suggesting that the (0001) surface is more hydrophilic. In addition, translational and rotational dynamics of interfacial water molecules are slower than that in bulk water, suggesting tight binding to the surface. Interfacial waters show two major polar orientations, either pointing to or away from the solid surface. In the former case, waters donate strong hydrogen bonds to the surface, while in the latter they accept relatively weak ones from aluminol groups. The strength of hydrogen bonds is estimated using their lifetime and geometry. We found that for all aluminols, water-to-aluminol hydrogen bonds are stronger and have longer lifetimes than the aluminol-to-water ones. One exception is the long lifetime of the \ce{Al3OH}-water hydrogen bonds on the ($11\overline{2}0$) surface, due to geometric constraints. Interactions between surfaces and interfacial waters promote a templating effect whereby the latter are aligned in a pattern that follows the underlying lattice of the mineral surface.

The Use of Apple Pomace as a Soil Amendment Enhances the Activity of Soil Microorganisms and Nitrogen Transformations and Affects Crop Growth

Apple pomace (AP) is an abundant waste causing environmental problems. Therefore, the aim of the study was to evaluate the impact of AP on soil and plant growth under optimum and limited water availability. Two laboratory experiments were conducted to evaluate the impact of AP on: (i) hydrophysical properties, respiration, and N transformations in soil aggregates and (ii) the growth of wheat and faba bean in soil with addition of AP under optimum and limited water availability. The soil respiration rate increased rapidly after the introduction of AP, and the effect was dependent on the aggregate size. The reduction of nitrate and the increase in ammonium content in response to the AP addition were more pronounced in the larger aggregates. Reduced growth of wheat was noted in the dry soil supplemented with AP. Faba bean maintained its unchanged rate of growth after the application of AP, irrespective of water availability. An increase in the chlorophyll content was observed in faba bean grown in the AP-enriched soil. The apple pomace reduced the water wetting rate and increased the repellency index but did not affect the tensile strength of the soil aggregates. Disposal of AP as a soil amendment affects many indicators of soil quality. The application of AP to the soil has an impact on respiration and N transformations in the soil aggregates; moreover, it differently influences the growth of spring wheat and faba bean.

Protective properties of superhydrophobic coatings on copper and steel obtained by electrochemical method

Superhydrophobic coatings are obtained by cathodic deposition of copper or nickel on a copper plate with treatment with an ethanol solution of highest carboxylic acids with a long hydrocarbon radical simultaneously or sequentially. They are characterized by a contact angle of water wetting of the order of 155...160°.These coatings protect the copper substrate from corrosion in conditions of 100% humidity for 100...180 days, while maintaining the contact angle within 152…154°. There is no mass loss. The influence of the reversal of the current during electrolysis on the value of the contact angle of wetting is investigated. SEM images of superhydrophobic coatings are presented, indicating multilevel roughness. Superhydrophobic coating on carbon steel is obtained by cathodic deposition of nickel and subsequent surface treatment in an ethanol solution of myristic acid and annealing at 60° for two hours. The influence of the duration of electrolysis on the value of the contact angle of wetting is estimated. Its value is in the range of 151…154°. Exposure of a coated steel plate for 50 days in conditions of 100% humidity is characterized by the absence of weight loss and maintaining the contact angle up to 154°.

Molecular Dynamics Simulations of Oil-Water Wetting Models of Organic Matter and Minerals in Shale at the Nanometer Scale

Wettability is an important physical property of shale. This parameter is related to the shale material composition and the fluid properties in the shale pores and plays an important role in the exploration and development of shale oil. Wettability is affected by the scale and roughness. The contact angle at the nanoscale on a smooth surface can better reflect the wettability of shale than the contact angle at higher scales. Molecular dynamics simulations can be used to measure the contact angle on a smooth surface at the nanoscale. This paper focuses on the effects of organic matter and minerals in shale and different components of shale oil on shale wettability. Wetting models of “organic matter-oil component-water,” “quartz-oil component-water” and “kaolinite-oil component-water” at the nanoscale were constructed. Molecular dynamics simulation was used to study the morphological changes of different oil components and water on different surfaces. Studies have shown that organic matter is strongly oleophilic and hydrophobic. Polar components in shale oil can make organic matter slightly hydrophilic. It was recognized by quartz wettability experiments and simulation methods at the nanoscale that the cohesive energy of a liquid has a significant influence on the degree of spreading of the liquid on the surface. The “liquid–liquid–solid” wettability experiment is an effective method for determining mineral oleophilic or hydrophilic properties. The nanoquartz in the shale is strongly hydrophilic. The water wetting angle is related to the crude oil component. Nanokaolinite can have a tetrahedral or an octahedral surface; the tetrahedral surface is oleophilic and hydrophobic, and the octahedral surface exhibits strong hydrophilicity. The wettabilities of both surfaces are related to the crude oil component.

Change in surface properties of tooth under cold atmospheric plasma impact

The article presents the results of experimental studies of the wetting angle of the tooth surface after treatment in the plasma of a dielectric barrier discharge at atmospheric pressure. Measurements of the dependence of the length of the plasma torch and the temperature of the treatment object on the flow rate of the working gas have been carried out. Argon was used as a working gas. The research revealed the possibility to change the length of the plasma torch in the range from 9 mm to more than 25 mm and showed that the temperature of the treated tooth surface with an increase in flow rate from 40 degrees Celsius falls to 32 degrees Celsius. The distilled water wetting angle was determined by the lying drop method. Depending on the processing time, a decrease in the contact angle of the tooth surface wetting from the initial 77 to 20 degrees was observed. The modes of operation of the plasma generator in tooth surface treatment, which provide the best indicators of its wettability, have been determined.