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Efficient diffusion barriers are necessary to prevent the formation of copper-tin intermetallic compounds (IMCs) in advanced packaging for Sn/Cu micro-bumps. This study investigated the interfacial properties of solder and Ni, Co-9W, Co-20W, Co-20Fe-10W, and Co-36Fe-17W barriers and determined the thickness of IMCs formed between Sn and these barriers after up to 15 reflows. Among the five barriers, Co-36Fe-17W proved to be the most effective in inhibiting the reaction of liquid Sn solder. At the Sn/Co-W interface, CoSn3 IMC was formed, while at the Sn/Co-Fe-W interface, CoSn3 IMC and FeSn2 IMC were observed. The contact angles of these layers were measured and found to be 18°, 22°, 25°, 29°, and 27°, respectively. The results showed that an increase in W content in Co-W led to an increase in the contact angle, while the intrinsic wettability of Co-Fe-W decreased with an increase in Fe content. The shear strengths of the five joints were 27 MPa, 31 MPa, 25 MPa, 25 MPa, and 26 MPa, respectively, with different fracture modes observed. The Co-Fe-W-Sn layer was partially peeling from the diffusion barriers in SAC305/Co-20Fe-10W, and the fracture surfaces exhibited an irregular and rough state, which was attributed to the increasing Fe and W contents. These findings offer valuable insights for enhancing the reliability of electronic packages. [ABSTRACT FROM AUTHOR]

The wetting ability of the material of interfacial formations based on metal stearates, oleates, myristates, and di-(2-ethylhexyl)phosphates was studied. It is shown that the nature of the metal and solvent on various substrates affects the wetting angle of the material. The material of interfacial formations has controlled wettability. By varying the synthesis conditions, it is possible to obtain homogeneous coatings, with the wetting angle of the product surface modified by the material of interphase formations reaching 145°. Experiments aimed at preserving the hydrophobic properties of the coating were performed. [ABSTRACT FROM AUTHOR]

The physical and chemical characteristics of hydrophobic protection of cement rock and concrete surfaces, using the binders based on polyurethane, elemental sulfur, and nanodimensional fillers of Tarkosil and thermally modified peat, are discussed. It is shown that a combined use of the physical texture-formation methods and an optimal selection of the protective coating chemical composition results in a significant increase of the wetting angle and the solid phase surface energy. It is found out that a directional orientation of the magnetically sensitive particles in the magnetorheological composites in a magnetic field is among the most effective methods for improving the protective coating properties. [ABSTRACT FROM AUTHOR]

Tight glutenite reservoir structure is complex, mineral types are multi-seepage, and most of them are non-Darcy's law flows Based on the finite element COMSOL simulation of seepage flow in glutenite water flooding, this chapter mainly explores the influence of several related factors on displacement recovery. With the increase of wetting angle, the wettability makes the porous state of solids and fluids in glutenite stable, so that water can easily push oil out, which leads to the increase of water flooding recovery The higher the injection rate, the higher the water cut in a short time, which makes the oil-water two-phase displacement accelerate and the higher the displacement recovery With the increase of gravel diameter, the oil saturation decreases less and more crude oil is bound by the pore structure surrounded by large particles, which is not conducive to displacement Small gravel particles have little influence on the front of water drive, and there is no obvious dominant channel, which leads to the recovery effect. [ABSTRACT FROM AUTHOR]

A physico-mathematical model is proposed for assessing the effect of centrifugal force on the characteristic dimensions of needle-shaped ice formed as a result of the collision of a large supercooled drop with a sphere rotating in a coaxial air flow. The mass loss of droplets upon collision with the surface due to splashing is taken into account. The numerical implementation of the model makes it possible to study the effect of surface properties on the icing process and, in particular, to estimate the ice-free surface area due to centrifugal force. [ABSTRACT FROM AUTHOR]

The paper studies the wetting effects on the characteristics of two-phase fluid flows in porous media. The originality of paper is a study of displacement under dynamic conditions when the action of viscous forces is significant. As a research tool, the methods of mathematical modeling are used – the lattice Boltzmann equations in a combination with a color-gradient model that describes interphacial interactions. Numerical experiments are carried out in a digital model of a porous medium characterized by a high degree of the pore space heterogeneity. In this work, a map of flow regimes in the coordinates “capillarity number – contact angle” is performed. The identification of four crossover modes between flows with capillary, viscous fingers and with a stable displacement front is carried out. Special attention is paid to the study of the influence of wetting effects on the specific length of the “injected fluid – skeleton” interface.

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Objective. To compare the structure and water repellent properties by determining the wetting angle of textured surfaces using metal master molds for making samples through various methods. Methodology. The structure of surfaces obtained through different manufacturing methods, namely templating method, filling the template with monomer followed by polymerization, and applying polymer and solvent solution followed by removal of the liquid medium, is studied using optical microscopy. The regularity of the structure was analyzed by digital images taken with optical microscopy. Water repellent properties were investigated using the sessile drop method with a goniometric attachment. Results. Textured surfaces were produced from various materials, including low-density polyethylene, polydimethylsiloxane rubber, and ethylene-propylene rubber. The methods used for their production are indicated. The qualitative characteristics of each surface, considering the template geometry, are described. A quantitative analysis of the wetting angle values of textured and non-textured surfaces was conducted. The causes and consequences of the deterioration in sample properties are supplemented, along with proposed methods for their resolution. Scientific novelty. Using optical microscopy to establish the optimal method for fulfilling one of the key conditions for producing textured surfaces. By utilizing a metal template, specifically aluminum, templates from other materials were created. Additionally, determining the quantitative impact of surface texturing on selected materials without fulfilling two other criteria. Practical significance. The described methods can be applied to scale up the process of manufacturing textured surfaces using lighter methods and a variety of materials. [ABSTRACT FROM AUTHOR]

Copyright of Precious Metals / Guijinshu is the property of Precious Metals Editorial Office 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.)

In many electro-optical devices, the conductive layer is an important key functional element. Among others, unique indium tin oxide (ITO) contacts take priority. ITO structure is widely used as the optical transparent and electrically conductive material in general optoelectronics, biosensors and electrochemistry. ITO is one of the key elements in the liquid crystal (LC) displays, spatial light modulators (SLMs) and LC convertors. It should be mentioned that not only the morphology of this layer structure but also the surface features play an important role in the study of the physical parameters of the ITO. In order to switch the surface properties (roughness, average tilt angle and surface free energy) of the ITO via the laser-oriented deposition (LOD) method, carbon nanotubes (CNTs) were implanted. In the LOD technique, the CO2 laser (λ = 10.6 μm, P = 30 W) with the control electric grid was used. The switching of the deposition conditions was provided via the varying electrical strength of the control grid in the range of 100–600 V/cm. The diagnostics of the surfaces were performed using AFM analysis and wetting angle measurements. The components of the surface free energy (SFE) were calculated using the OWRK method. The main experimental results are as follows: the roughness increases with a rise in the electric field strength during the deposition of the CNTs; the carbon nanotubes provide a higher level of the dispersive component of SFE (25.0–31.4 mJ/m2 against 22.2 mJ/m2 in the case of pure ITO); the CNTs allow an increase in the wetting angle of the 5CB liquid crystal drops from 38.35° to 58.95°. Due to the possibility of the switching properties of the ITO/CNT surfaces, these modifications have potential interest in microfluidics applications and are useful for the liquid crystal's electro-optics. [ABSTRACT FROM AUTHOR]

Polymer resins based on acrylates obtained from Bis-GMA (Bisphenol A glycide methacrylate), which is suitable for photopolymerization, are used in dentistry for various purposes due to the ease of application and the possibility to influence their properties by adding reinforcements of different shapes, crystal structure and chemical compositions. Reinforcement in the form of particles based on MgAlLDH (layered double hydroxide) deposited on silica obtained from rice husks on two substrates. A metal base and glass were used. The adhesive properties are important in order to see the possibility of using these materials in applications. In order to measure the adhesive properties of the material, the composite microhardness measurement method is used by applying different loads in order to evaluate the adhesion parameter that shows the effect of the coating on the substrate. It was compared to how a pure photopolymerizing acrylate matrix bonds with a chromium-based dental alloy substrate that is used in the production of different parts of dentures by bonding to a glass substrate. Then, it was compared how composite materials are bonded to both substrates. Adhesion was monitored through the change in wetting angle between the composites, and the results were compared with the results of microindentation. It was shown that the addition of composite particles increases the adhesive properties of the composite compared to the pure matrix and that better adhesion is achieved between the composite and the metal substrate than between the composite and the glass substrate.

The HS6-5-2C steel samples with different surface roughness were used for the tests. After grinding had a roughness parameter of Ra = 0,03 μm, and after polishing Ra = 0,01 μm. A TiAlN coating was applied to the substrate prepared in this way. Using a confocal microscope with an interferometric mode, the geometrical structure of the samples was analyzed. The optical strain gauge was used to measure the contact angle. Tribological tests were carried out in conditions of technically dry friction. The polished sample with the coating was characterized by a more stable course of the friction coefficient, lower wear and a smaller wetting angle.

The paper presents the experimental results on the determination of melt parameters such as the energy of the boundary, contact angle, density and kinematic viscosity of low and medium alloy steels at different temperatures, as well as the dispersion of their dendritic structure in solidified castings. The analysis of the data obtained allowed revealing using mathematical models the influence of the chemical composition and temperature of melts on their properties and the dendritic structure of castings. It was established the variation of the melt parameters depending on the particular chemical elements of steels as C, Si, Mn, O, P, V, Cr. The established analytical dependences shown that increasing density and viscosity contributes to the dispersion of the dendritic structure and viscosity is of the major effect. The derived quantitative patterns allows to evaluate structure formation of cast structural low and medium alloy steels. [ABSTRACT FROM AUTHOR]

Copyright of Natural Gas Industry is the property of Natural Gas Industry Journal Agency 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.)

This work focuses on wetting two types of substrates (a platinum substrate and a polished graphite substrate) by molten polycomponent oxide system CaO–MgO–SiO2–Al2O3–B2O3 to test the level of interaction at high temperatures. The tested systems were subjected to high-temperature wetting tests in the temperature range from liquidus temperature to 1550 °C using the sessile drop method. A total of four oxide systems were tested with graded boron oxide contents ranging from 0 to 30 wt%. The experiments were conducted in a CLASIC high-temperature resistance observation furnace and an inert atmosphere of high-purity argon. Droplet silhouettes were obtained with a CANON EOS 550D high-resolution camera during heat treatment, with reactive and non-reactive wetting occurring depending on the substrate type. The dependence of the average wetting angles on temperature and time was evaluated, and it was found that boron oxide decreased the average wetting angles of molten oxide droplets. The analyses were accompanied by the SEM/EDX analysis of the substrate and FTIR analysis of the droplets after high-temperature experiments. The phase composition of the oxide systems was evaluated by XRD analysis. [ABSTRACT FROM AUTHOR]

Relevance. Caused by the need to ensure highly efficient distribution of spent sulfuric acid solutions during acid treatment of a production well bottomhole zone. The proposed method increases the efficiency of this process by growth of efficiency of production wells exploiting terrigenous limestone reservoirs in the wellbore zone. Aim. To develop and propose a method for using spent sulfuric acid solutions during acid treatment of a production well bottomhole zone, a methodology for its application. The essence of the method is that to increase the efficiency of production wells exploiting terrigenous reservoirs, solutions of sulfuric acid or its derivatives, in particular spent sulfuric acid, are used as an acid reagent. Objects. It was revealed that the surface activity of spent sulfuric acid in fresh water at the interface with hydrocarbon liquids is significantly greater than the activity of solutions of commercial hydrochloric and sulfuric acids. Based on physical and chemical studies, it has been established that spent sulfuric acid solutions can be used in acid treatment of the bottomhole zone of wells to increase formation fluid production. Solutions of hydrochloric (HCl) and sulfuric (H2SO4) acids, as well as waste – spent sulfuric acid, were used as experimental liquids. Compared to commercial acids, the spent sulfuric acid solutions have the greatest ability to interact in carbonate rocks. Methods. Models of porous medium were created in experimental columns, which were pipes made of organic glass with a length of 0.5 m and a diameter of 0.025 m. The manufactured model of the porous medium was evacuated and saturated with fresh water, after which the water permeability was determined, then the water was replaced with acid solutions. After a certain time for the acid to react with the carbonates of the porous medium, the water permeability was again determined. The experiments were carried out at room temperature and a pressure gradient of 0.05...0.2 MPa/m. Moreover, after completion of the treatment of the near-wellbore zone in order to prevent the deposition of sediments formed in the pores as a result of the interaction of acid with carbonates, the well is put into operation after an eight-hour holding period with large depressions in the near-wellbore zone. Results. Visual observations shown that water filtration through the porous medium at high pressure gradients leads to a large removal of sediments from the porous medium. This is the consequence of an increase in the porous medium permeability after treating it with a 15% solution of waste sulfuric acid. Thus, laboratory experiments shown that the use of spent sulfuric acid solutions under certain conditions can increase well productivity.

Surfactant flooding is one of the most effective methods of enhanced oil recovery, because it helps to reduce oil-water interfacial tension and mobilize the residual oil. Surfactant molecules can be adsorbed on the particle surface. This paper presents a systematic study of the dynamic adsorption of a water-soluble surfactant during flooding of oil-saturated porous media. The novelty lies in the study of dynamic adsorption with multiphase flows in porous media, which provides new trends. The main goal is to reveal the effect of wetting angle, interfacial tension, flow rate, and adsorption rate constant on the adsorbed amount in the immiscible displacement. Lattice Boltzmann simulations are used to study this problem. The flow regions are represented by digital images of granular porous structures. A map characterizing the adsorbed amount of surfactant versus wetting angle and interfacial tension has been presented. The results showed that increasing the wetting angle positively affects the adsorbed amount, while increasing interfacial tension suppresses the adsorbed value. Different patterns of dynamic adsorption in dependence on flow rate and adsorption rate constant have been identified. At low adsorption rates, regardless of the wetting angle and interfacial tension, a decrease in the flow rate contributes to an increase in the adsorbed amount. At high adsorption rates, the adsorbed amount is determined by the displacement efficiency. The obtained tendencies have been validated by performing a series of simulations on a group of porous structures. It has been found that the prediction reliability of the adsorbed amount increases with increasing wetting angle and capillary number. • Adsorbed amount is significantly affected by interfacial tension and wetting angle. • The highest adsorbed values have been obtained in the viscous fingering regime. • At high adsorption rate, the adsorbed amount is determined by the displacement efficiency. • Prediction accuracy of the adsorbed amount increases with wetting angle and capillary number. [ABSTRACT FROM AUTHOR]

This study investigates the influence of process parameters on catchment efficiency and geometric characteristics such as track height, track width, and wetting angle for low energy density inputs in the blown powder Laser Metal Deposition (LMD) process for building thin-walled parts or repair volumes. Initially, a pilot study was conducted to examine the process parameters that affect catchment efficiency and geometric characteristics, from which five different process parameters such as (i) Laser power, (ii) Carrier gas flow rate, (iii) Deposition speed, (iv) Stand-off distance, and (v) Powder feed rate were identified as parameters of significance to the study. The impacts of these process parameters on catchment efficiency and geometric characteristics were investigated experimentally, and the data were analyzed using ANOVA and Response Surface Methodology (RSM). An analytical model was developed to predict the catchment efficiency, which was validated through experimentation. A comparison was made between the analytical, empirical, and experimental models for catchment efficiency, and it was found that the error was less than 8% which shows relatively good agreement between the proposed and experimental measurements. Furthermore, an empirical-statistical method was employed to establish the relationship between the chosen process parameters, catchment efficiency, and geometric characteristics to fabricate a single continuous track. Based on these correlations, a process map was constructed to identify the optimal processing conditions to obtain a single continuous track of IN625 powder on SS304 substrate with a higher catchment efficiency. This study achieved a maximum catchment efficiency of 71% for a low-energy density input. [ABSTRACT FROM AUTHOR]

The results of complex studies on the brazing filler metal of the Cu–Mn–Co system alloyed with iron in the range of 1…5 wt. % are presented. The melting point was determined through calculation, and it was shown that increasing the concentration of iron from 1 to 5 wt. % leads to a slight (from 912 to 923 °C) increase in the temperature of the solidus and a significant increase in the temperature of the liquidus (from 931 to 1027 °C). At the same time, the melting temperature range expands to 104 °C. The results of experimental studies on the spread of brazing filler metal on Kovar and corrosion-resistant steel have established that an increase in the iron concentration up to 5 % contributes not only to an increase in the temperature of the liquidus but also to an increase in the spread area, which is due to the melting temperature of a copper-based solid solution. Local micro-X-ray spectral analysis established a discrete distribution of constituent elements and showed that the brazing filler metal, after spreading, contains two solid solutions: copper-based and manganese-based. The research results on the Kovar-corrosion-resistant steel brazed joints have demonstrated that the addition of iron to the Cu–Mn–Co–Fe alloy leads to an increase in microhardness and shear strength. [ABSTRACT FROM AUTHOR]

The results of complex studies on brazing filler metals of Cu-Mn-Co-Fe system alloyed with iron in the range of 1-5 wt.% are presented. The melting point was determined through calculation, and it was shown that increasing the concentration of iron from 1 to 5 wt.% leads to a slight (from 912 °C to 923 °C) increase in the solidus temperature and a significant increase in the liquidus temperature (from 931 °C to 1027 °C). At the same time, the melting temperature range expands to 104 °C. The results of experimental studies on spreading of brazing filler metals over Kovar and corrosion-resistant steel have established that an increase in the iron concentration from 1 to 5 % contributes not only to an increase in the liquidus temperature, but also to an increase in the spreading area, which is due to the melting temperature of a copper-based solid solution. Local X-ray microanalysis established a discrete distribution of constituent elements and showed that the brazing filler metal contains two solid solutions after spreading: copper-based and manganese-based. The research results on overlap brazed joints of Kovar - corrosion-resistant steel have demonstrated that addition of iron to Cu-Mn-Co-Fe alloy leads to an increase in microhardness and shear strength. [ABSTRACT FROM AUTHOR]

The article explores the effect of a natural dust film, deposited from the air, on the generation of gravity–capillary wind waves with a wavelength m. It is shown that with an increase in the deposition time of hydrophobic dust particles on the water surface, the contact wetting angle between the water surface and the hydrophobic particle increases, indicating an augmentation in the surface tension coefficient. At the same time, the approach time of hydrophobic particles lengthens. It is found that as the film concentration increases for a given wind speed, the wavelength of the wind wave in the generation zone decreases, while the steepness grows, which is associated with an increase in roughness and the friction coefficient at the interface boundary. Nonlinear plane waves with steepness arise in the generation zone. A method for calculating the phase velocity of such waves is obtained and verified. The critical wind speed value at which the generation of wind waves begins decreases with an increase in the concentration of dust film, and the values lie in the interval m/s. [ABSTRACT FROM AUTHOR]

The working face blasting dust of Dexing Copper Mine was taken as the research object, and hydrophilic dust (HD, sinking quickly to the bottom) and hydrophobic dust (HCD, floating on the surface for a long time) were separated. The wettability was quantitatively characterized by measuring the wetting contact angle of the two, and the physicochemical properties of the dust particles were comprehensively characterized by measuring the particle size distribution, surface properties, elemental composition, and phase composition of the dust particles. Finally, by comparing the differences in physicochemical properties between HCD and HD, the key factors affecting the wettability of dust were investigated. The results indicate that the wetting angle of HCD is much smaller than that of HD at any given time. When the wetting contact angle of HCD reaches 20° and is in a relative equilibrium state, HD tends to 0°. In terms of wetting properties, the average particle size of HCD is 21.97% smaller compared with HD, which makes HCD have a larger mass-specific surface area, surface energy, and surface activity. Additionally, the true density of HCD is 4.54% lower than that of HD. HCD is less affected by gravity and has a more complex surface pore structure, resulting in a more pronounced air film effect on the surface of dust particles. The formation of an air film greatly weakens the dust's wettability. Therefore, particle size and surface structure are the main factors affecting the dust's wettability. Organic substances cannot be detected in the HCD and HD spectra, indicating that both HCD and HD are hydrophilic phases, which determines the overall wettability of blasting dust. The phase composition of HCD and HD is similar, and the difference in the content of hydrophobic groups (C-C, C-H) between them is less than 3%, so the surface groups are not the main factors affecting the wettability of dust. [ABSTRACT FROM AUTHOR]

Superhydrophobic coating is obtained by cathodic deposition of copper from a solution of 0.25 M CuSO4 + 0.5 M H2SO4 at a current density of 0.25 A/cm2 for 30 s on copper foil, followed by exposure to 0.01 M ethanolic solution of stearic acid for 1 h. The wetting angle of the water-formed coating is 155°–157°. Corrosion testing of copper samples with the resulting coating is carried out in a temperature-humidity chamber for 40 days, in an atmosphere with 100% humidity for 186 days and under conditions typical for livestock buildings, at 100% humidity and in the presence of CO2 corrosion accelerators, H2S and NH3 in pairs and simultaneously all three in maximum permissible concentrations for 46–56 days. In all cases, the coatings retain their superhydrophobicity, the wetting angle either remained almost unchanged or decrease by 2°–3°, and there is no corrosion damage on the samples. The influence of the copper electrodeposition mode from the solution of 0.25 M CuSO4 + 0.5 M H2SO4 on the wetting angle of the resulting coating is evaluated. [ABSTRACT FROM AUTHOR]

Wood as a structural material has a number of disadvantages, including a short service life, relatively low dimensional stability, significant volumetric deformations under the influence of moisture, pronounced anisotropy and water absorption. Thermomodification slightly improves physical and mechanical properties, but the problem of changing surface characteristics, in particular adhesion, arises. In order to determine the technological characteristics of thermally modified wood and to develop possible measures to improve the technology of applying protective coatings, the surface energy and compressive strength limit along the fibers were determined. A comprehensive approach is applied to analyze the state of the thermally modified wood surface through the study of surface energy characteristics based on the Fowkes method, which takes into account dispersion, hydrogen and dipole-dipole interactions at the solid-liquid interface. According to the marginal angle of wetting, it was found that the process of thermal modification wood helps to increase the resistance of its surface to wetting due to a decrease in polarity by 1.68 times with an increase in the duration of modification to 30 min. At the same time, the surface free energy for samples modified at 300 °C for 5 min. is 64.5 mJ/m2, during 30 min. – 24.1 mJ/m2. Regarding compressive strength, thermal modification reduces the strength limit by 1.46 times. At a temperature of 300 ºС and a time of 5 min. and 15 min. the indicator remains at the level of ordinary wood – 42 MPa. Treatment for 30 min. reduces the strength limit to 29 MPa, wood loses plasticity. The obtained results make it possible to effectively choose stable coatings for such wood for high-quality surface treatment with paint and varnish materials. Knowing the moment of time from which the reduction of the strength limit begins, conducting the process of thermal modification becomes more controlled and makes it possible to predict the characteristics of the future material

The author has obtained the isotherms of wedging pressure of β films from the data on the velocities of flow in an inhomogeneous electric field of films of model liquids on the surface of quartz capillaries of different radii. Increase in the field gradients leads to a deviation of the films from the equilibrium state toward a growth in their thickness. [ABSTRACT FROM AUTHOR]

Influence of the composition of the cold cured epoxy diane resin of ED-20 brand and its modifications on the water absorption and wetting properties is studied. Organosilicon additives polydimethyl siloxane (PDMS-5, 2.5 wt%), and nano-dispersed amorphous pyrogenic silica (HDK, 0.5 wt%) were used. Industrial fillers such as Volsky sand (EN 196–1), and the slag Portland cement of grade PC 400-D20 are also applied to the epoxy binder modifications for repair and building composites. The introduction of organosilicon additives reduces significantly the water absorption. In particular, the addition of PDMS-5 reduces the water absorption by 22% in comparison with unmodified samples. Water absorption decreases by more than 30% when (PDMS-5 + HDK) gel modifier is added. The introduction of industrial fillers in various proportions and compositions increases water absorption. It is found that the contact angle of the epoxy binder is linearly dependent on the mass fraction of the curing agent. The equation of the contact angle dependence on the curing agent mass fraction sufficiently fitting the experimental data was obtained. The introduction of PDMS-5 reduces the contact angle by 13% in the case of a metal background and 35% in the case of a concrete background. The contact angle decreases by 34% with the addition of (PDMS-5 + HDK) gel modifier in the case of metal background and decreases by 76% in the case of concrete background. [ABSTRACT FROM AUTHOR]

The adhesive properties of brand BND 60/90 road bitumen with the oxidized phosphatide concentrate additive were studied. It was shown that the oxidized phosphatide increases the adhesive properties of bitumen brand BND 60/90. Oxidized phosphatide concentrate can be recommended as cost-effective alternative to expensive synthetic cationic surfactants, which are now widely used as adhesives for road bitumen. Based on the results of laboratory tests, the mathematical analysis of the obtained data was performed. Comparative graphs were plotted, and Pearson’s correlation coefficients and the approximation reliability values were calculated. It was found that the optimal composition for creating effective bituminous compositions with an increased thermo-physical and adhesive characteristics is 0.6 wt.% of oxidized phosphatide concentrate. [ABSTRACT FROM AUTHOR]

Influence of concentration of introduction the different industrial organic additives into the epoxy resin on wetting contact angle is studied experimentally. Epoxy resin ED-20 is modified with small concentrations of polydimethyl siloxane, OH-polymer silicone rubber, monoglycidyl ether of butyl cellosolve (Laproxide 301B), tris(2-chloroethyl) phosphate. The importance of these studies is related to the need to improve the adhesive properties of repair compounds based on epoxy resin, which are associated with the value of the contact angle. The contact angle of the resin drop is measured for glass, metal, asbestos cement, and concrete surfaces. The effect of the mass fraction of additives on the contact angle is more pronounced on smooth surfaces of dense materials, and less pronounced on rough surfaces of porous materials. It is observed that all dependences of contact angle on the mass fraction of additives in the range of 0.5–2% wt are linear. The linear equation θ = s ⋅ c + θ 0 describing the contact angle θ dependence on the mass fraction c of additives, which sufficiently fitting the experimental data with calculated coefficients s and θ0, is found. [ABSTRACT FROM AUTHOR]

This work focuses on wetting two types of substrates (a platinum substrate and a polished graphite substrate) by molten polycomponent oxide system CaO–MgO–SiO2–Al2O3–B2O3 to test the level of interaction at high temperatures. The tested systems were subjected to high-temperature wetting tests in the temperature range from liquidus temperature to 1550 °C using the sessile drop method. A total of four oxide systems were tested with graded boron oxide contents ranging from 0 to 30 wt%. The experiments were conducted in a CLASIC high-temperature resistance observation furnace and an inert atmosphere of high-purity argon. Droplet silhouettes were obtained with a CANON EOS 550D high-resolution camera during heat treatment, with reactive and non-reactive wetting occurring depending on the substrate type. The dependence of the average wetting angles on temperature and time was evaluated, and it was found that boron oxide decreased the average wetting angles of molten oxide droplets. The analyses were accompanied by the SEM/EDX analysis of the substrate and FTIR analysis of the droplets after high-temperature experiments. The phase composition of the oxide systems was evaluated by XRD analysis.

Copyright of Refractories / Naihuo Cailiao is the property of Naihuo Cailia (Refractories) Editorial Office 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 Earth's fluid budget is dominated by species in the system C–O–H–N–S together with halogens such as F and Cl. H2O is by far the most abundant. Such fluids are one of the two main mass transport agents (fluid and magma) in the Earth. Among those, in particular aqueous fluids are efficient solvents of geochemically important components at high temperature and pressure. The solution capacity of aqueous fluids can be enhanced further by dissolved halogens and sulfur. CO2 or nitrogen species has the opposite effect. Fluid-mediated transport in the Earth is by fluids passing through cracks at shallow depth and via percolation channels along grain boundaries at greater depth. Percolation velocity is linked to permeability, which, in turn is governed by rock porosity. Porosity is controlled by wetting angles, θ, at the interface between fluid and mineral surfaces. When θ < 60°, fluid will wet all grain boundaries of an isotropic crystalline material, whereas when greater than 60°, grain boundary wetting does not occur as readily, and fluid-mediated transport efficiency can be greatly reduced. The size of the wetting angle is negatively correlated with the solubility of silicate components in the fluids, which means that fluid composition, temperature, and pressure affect the wetting angles and, therefore, fluid-mediated mass transport efficiency in the interior of the Earth. Geophysical and geochemical anomalies in the Earth's interior have been linked to the presence of fluids. Fluid infiltration in crustal and mantle rocks will enhance electrical conductivity and seismic wave attenuation. For example, 5–10% H2O-rich fluids in the mantle wedge above subducting plates have been suggested from enhanced electrical conductivity. Similar fluid fractions have been suggested to be consistent with seismic velocities in these regions. The geochemistry of the crust and the mantle can be affected by fluid-mediated transport of major, minor, and trace elements. When such altered materials serve as source rocks of partial melts, those geochemical alterations also lead to changes in partial melt compositions. As an example, the presence of such aqueous fluid in the mantle wedge above subducting and dehydrating subducting slabs is consistent with partial melting of an H2O-bearing mantle wedge above subducted oceanic crust. [ABSTRACT FROM AUTHOR]

In this study, a method for ensuring reliable and safe operation of marine trunk diesel engines is considered. The research was carried out on 5L23/30 MAN-B&W diesel engines of a Bulk Carrier class vessel. The objective of the study was to determine the effect of the structural characteristics of the oil layer (wetting angle and thickness) on the operational parameters of a marine diesel engine (compression pressure, concentration of nitrogen oxides in exhaust gases and temperature of exhaust gases after the cylinder) and performance characteristics of the oil (base number, wear and contaminant elements). It has been established that an increase in the degree of the contact angles of wetting and in the thickness of the oil layer improves the heat and power and environmental performance of a diesel engine. At the same time, the decrease in compression pressure in the cylinder slows down, the temperature of gases after the cylinder decreases, and the emission of nitrogen oxides with exhaust gases decreases. Also, it was found that wear of diesel parts and oil oxidation are reduced. The study confirms the possibility of improving the reliable and safe operation of trunk-type diesel engines of maritime vessels by effective control of variables relating to the characteristics of engine oil. [ABSTRACT FROM AUTHOR]

Orthodontic removable appliances made of transparent thermoplastic materials—aligners—are becoming increasingly popular in contemporary orthodontic practice. It is important for the clinician to fully understand the mechanical properties and behavior of the appliance used. Because of that, the aim of our study was to investigate the changes in aligner surface after immersion in Coca-Cola and orange juice. For surface evaluation, fractal analysis, texture analysis, and wetting angle measurement were performed. Statistically significant changes were found between some of the groups in the fractal dimension analysis. In texture analysis, all but one intergroup comparison showed statistically significant differences. For wetting angle assessment, statistically significant differences were found. These were, however, more numerous when assessing glycol droplets, rather than water droplets. Fractal dimension analysis confirmed a correlation between the intensity of changes in the aligner surface with immersion time in the liquids assessed. Texture analysis showed a high sensitivity to the changes in aligner surface. It failed, however, to reveal changes relative to immersion time. Wetting angle analysis revealed aligner surface degradation for Coca-Cola. It did not, however, prove the dependence of the intensity of this degradation as a function of time. Both Coca-Cola and orange juice can cause aligner surface degradation. [ABSTRACT FROM AUTHOR]

Among the different nanostructures involved in the improvement of material properties, carbon nanotubes occupy a specific place because of their small refractive index, extended surface, and large Young's module, which can all provoke dramatic change in basic matrix material characteristics. Inorganic crystals, semiconductors, metals, conductive compounds, and some polymer structures whose surfaces are treated with carbon nanotubes demonstrate better features than the ones obtained before carbon nanotubes deposition. Thus, the areas of application for these unique nanostructure materials can be effectively extended, e.g., for optoelectronic use, in biomedicine, and display applications. In the current paper, the advantages of the laser-oriented deposition technique are shown in order to demonstrate how the main material parameters change drastically through the incorporation of carbon nanotubes. [ABSTRACT FROM AUTHOR]

Droplet epitaxy technology is not only suitable for lattice mismatch, but also suitable for lattice matched material systems, and is easy to prepare low - dimensional semiconductor structures, such as low-density quantum dots, rings, etc. In this paper, the growth of quantum dots with different Al and Ga compositions on GaAs surface by droplet epitaxy method was studied. In the experiment, the samples were monitored in situ with Reflection High Energy Electron Diffraction (RHEED). The composition of Al and Ga droplets deposited on the substrate was controlled by controlling the deposition rate of Al and Ga droplets. It was found that the quantum dots become denser and the wetting angle became lower with the increase of Al composition. When the Al component increased by more than 0. 5, quantum dots of different sizes appeared, and the dot density increased exponentially. An empirical formula is given and the phenomenon is explained. [ABSTRACT FROM AUTHOR]

Wood as a structural material has some disadvantages, which include a short service life, relatively low form resistance, considerable volumetric deformations under moisture, pronounced anisotropy, and water absorption. Thermal modification slightly improves the physical and mechanical properties. However, a problem of changing surface characteristics occurs, specifically adhesion. To determine the technological characteristics of thermally modified wood and develop possible measures to improve the technology of applying protective coatings, the surface energy and compressive strength along the fibres were determined. A comprehensive approach was applied to analyse the surface state of thermally modified wood through the investigation of surface energy characteristics based on the Fowkes method, which considers dispersion, hydrogen, and dipole-dipole interactions at the solid-liquid interfacial boundary. According to the marginal angle of wetting, it was found that the thermal modification of wood helps increase the resistance of its surface to wetting by reducing the polarity by 1.68 times with an increase in the duration of modification to 30 min. Therewith, the surface free energy for samples modified at 300°C for 5 min is 64.5 mJ/m², for 30 min – 24.1 mJ/m². Regarding compressive strength, thermal modification reduces the strength limit by 1.46 times. Thus, at 300°C and a time of 5 min and 15 min, the indicator stays at the level of ordinary wood – 42 MPa. Processing for 30 minutes reduces the strength limit to 29 MPa, the wood loses its plasticity. The obtained results allow effectively choosing stable coatings for such wood for high-quality surface treatment with paint and varnish materials. Knowing the moment of time from which the reduction of the strength limit begins, thermal modification becomes more controlled and allows predicting the characteristics of the future material. [ABSTRACT FROM AUTHOR]

The purpose of the article was to evaluate the physicochemical properties of the Ti6Al4V titanium alloy with a zinc oxide layer deposited by the atomic layer deposition method. The surface modification promotes changes in the chemical character of the surface according to two basis wettability states, namely the Wenzel state and the Cassie-Baxter state. To evaluate the mechanisms of wettability changes, the contact angle measurements and the surface free energy calculations (according to the Owens-Wendt methods) were performed. It was found, based on X-ray photoelectron spectroscopy, that the hydrophobic properties of the oxide layer are related to the presence of metal cations, oxygen anions, and hydroxyl groups on the surface. Additionally, the method of electrochemical impedance spectroscopy was used to define the morphological peculiarities of the coating on the basis of the registered impedance spectra. [ABSTRACT FROM AUTHOR]

In this paper, we present the results of testing the algorithm for calculating the Hamaker constant proposed by the authors as characteristics of the dispersion interaction according to experimental data obtained by studying the composition of fine powders of basalt and polymineral sand. For this purpose, on the basis of a number of assumptions, the concept of an analog Hamaker constant is introduced, which is an experimentally determined quantity. This parameter is recommended for use when choosing the quantitative ratio of powder raw materials as a criterion for assessing the maximum possible van der Waals effect of dispersion interaction. An assumption was made about the presence of a constant characteristic of a thin film wetting the analyzed surface. Moreover, this thin film has a contact angle of the transition region "film-bulk phase," the value of which is determined by the nature of the surface and the properties of the wetting liquid. The contact angle of the transition region can be an additional quantitative criterion for the selection of materials that are compatible in nature. [ABSTRACT FROM AUTHOR]

In the past years, plant-based surfactants such as plant proteins, hydrocolloids, and extracts have intrigued scientific studies of food formulations for usage in emulsion, nanoemulsion as well as microemulsion systems, mainly due to their functional benefits and low toxicity levels. In this work, a hemp seed oil-containing (HSO) emulsion system was stabilized using soap nuts (SN), also known as Sapindus mukorossi. In order to determine the formulation requirements and the optimal emulsion composition including oil and surfactant content, a Box-Behnken experimental design was applied. The compositions were evaluated in terms of their particle size distribution, stability, visual quality, turbidity, and zeta potential. Moreover, to describe the physicochemical characteristics of the emulsions, rheological tests, Fourier transform infrared spectroscopy (FTIR) analyses, and refractive index parameters were also studied. The average particle size of the emulsions (particle distribution by number) was recorded between 51 and 103 nm, and z-ave parameter reached values between 227 nm and 311 nm. The zeta potential increased when the proportion of HSO increased, and reached its highest value (−23.5 mV) when HSO was 5% v/v. Microscopic investigations confirmed the polydispersity of the prepared emulsions. Furthermore, due to further applications of the emulsions i.e. packing and delivery, wetting properties were evaluated. The wetting angle values reached maximum approx. 30° with an HSO content of 1%. However, the wetting angle values were lower with increasing HSO content. Presented results revealed that Sapindus mukorossi is indeed a good stabilizer for hemp seed oil and water emulsions. [Display omitted] • Oil in water hemp seed oil-based emulsions stabilized by soap nuts were prepared. • Particle size, microscopy, and centrifugation tests were used for stability evaluation. • The long-term stability of the emulsion was confirmed. • Wetting properties and viscosity test of the emulsion exhibit an oil content role. [ABSTRACT FROM AUTHOR]

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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.