Initial Viscosity Research Articles

Evaluation of the injection and plugging ability of a novel epoxy resin in cement cracks

Sustained casing pressure (SCP) is a crucial issue in the oil and gas production lifecycle. Epoxy resins, exhibiting exceptional compressive strength, ductility, and shear bonding strength, have the potential to form reliable barriers. The injectivity and sealing capacity of the epoxy resin is crucial parameters for the success of shallow remediation operations. This study aimed to develop and assess a novel solid-free resin sealant as an alternative to Portland cement for mitigating fluid leakage. The investigation evaluated the viscosity, compressive strength, and brittleness index of the epoxy resin sealant, as well as its tangential and normal shear strengths in conjunction with casing steel. The flow characteristics and sealing abilities of conventional cement and epoxy resin were comparatively analyzed in cracks. The results showed that the application of a viscosity reducer facilitated control over the curing time of the epoxy resin, ranging from 1.5 to 6 h, and reduced the initial viscosity from 865.53 to 118.71 mPa⋅s. The mechanical properties of the epoxy resin initially increased with a rise in curing agent content before experiencing a minor decrease. The epoxy resin containing 30% curing agent exhibited optimal mechanical properties. After a 14-day curing period, the epoxy resin's compressive strength reached 81.37 MPa, 2.12 times higher than that of cement, whereas the elastic modulus of cement was 2.99 times greater than that of the epoxy resin. The brittleness index of epoxy resin is only 3.42, demonstrating high flexibility and toughness. The tangential and normal shear strengths of the epoxy resin exceeded those of cement by 3.17 and 2.82 times, respectively. In a 0.5 mm-wide crack, the injection pressure of the epoxy resin remained below 0.075 MPa, indicating superior injection and flow capabilities. Conversely, the injection pressure of cement surged dramatically to 2.61 MPa within 5 min. The breakthrough pressure of 0.5 PV epoxy resin reached 7.53 MPa, decreasing the crack's permeability to 0.02 D, a mere 9.49% of the permeability observed following cement plugging. Upon sealing a 2 mm-wide crack using epoxy resin, the maximum breakthrough pressure attained 5.47 MPa, 3.48 times of cement. These results suggest that epoxy resin sealant can be employed safely and effectively to seal cracks in the cement.

EFFECT OF SOIL GELS ON HYSTERESIS PHENOMENA IN SOILS

Based on the analysis of the exist mechanisms of the hysteresis of soil water retention curve (WRC), as well as ideas about the nanostructural organization of soils, it is concluded that hysteresis can be caused either by stable (non-colloidal particles) or labile (gels) parts of the solid phase of soils. Due to the fact that until now the main attention has been paid to the study of the effect of stable solid phase of soils on the hysteresis of WRC, it was proposed to investigate the effect of soil gels on hysteresis. For this purpose, the effect of moisture content of soil samples prepared by drying and moistening on the initial viscosity of soil pastes was studied. It has been established that well-pronounced hysteresis is observed for samples of all studied soil types. To explain the hysteresis, two mechanisms based on changes in soil gels in the humidification-drying processes are proposed. One of them is based on the slowness of swelling and shrinkage of soil gels when they absorb and release water. The second is on the greater hydrophobicity of the surface of gels containing less water, and water slipping on hydrophobic areas of the surface with a decrease in the viscosity of pastes. Thus, the conducted studies have shown that hysteresis phenomena in soils are caused by soil gels and their changes during drying and moistening of soils.

Chemorheology of a Si/Al > 3 Alkali Activated Metakaolin Paste through Parallel Differential Scanning Calorimetry (DSC) and Dynamic Mechanical Analysis (DMA).

Although geopolymers, as structural materials, should have superior engineering properties than traditional cementitious materials, they often need to improve their final characteristics' reproducibility due to the need for more control of the complex silico-aluminate decomposition and polymerisation stages. Thermosetting of a reactive geopolymeric paste involves tetrahedral Silicate and Aluminate precursor condensation into polyfunctional oligomers of progressively higher molecular weight, transforming the initial liquid into a gel and a structural solid. Viscosity and gelation control become particularly critical when the geopolymer is processed with 3D printing additive technology. Its physical state modification kinetics should match the flow and setting characteristics required by the deposition process. The reaction kinetics and the elastic and viscous characteristics preceding gelation and hardening have been investigated for an alkali-activated Metakaolin/Sodium Silicate-Sodium Hydroxide paste with a Si/Al ratio > 3. A chemoreological approach has been extended to these inorganic polymerisable systems, as already utilised for organic thermosetting polymers. Differential scanning calorimetry and Oscillatory DMA were carried out to monitor the advancement of the polymerisation reaction and the associated variations of the rheological viscoelastic properties. Dynamic thermal scans were run at 1 °C/min and a frequency of 10 Hz for the dynamic mechanical tests. The observed kinetics of polymerisation and variations of the elastic and viscous components of the complex viscosities and shear moduli are described in terms of polycondensation of linear and branched chains of oligomeric macromolecules of increasing complexity and molecular weight up to gelation (Gel1) and cross-linking of the gelled macrostructure (Gel2) and final glassy state. Geopolymerization can be allocated into two main behavioural zones: a viscoelastic liquid paste below 32.5% of reaction advancement and a viscoelastic solid above. Initial complex viscosities range from 2.3 ± 0.9 × 10-5 MPa*s to 6.8 ± 0.9 × 10-2 in the liquid-like state and from 1.9 ± 0.1 MPa to 9.6 ± 2.1 × 102 MPa in the solid-like state.

Evaluation of hydrogen peroxide permeability, color change, and physical-chemical properties on the in-office dental bleaching with different mixing tip.

This study aims to assess hydrogen peroxide (HP) penetration into the pulp chamber, color change (CC), physical-chemical properties, and material wastage (MW) and material used (MU) in mixing tips when using in-office bleaching gels with two different mixing tips. Forty teeth were divided into five groups (n = 8) based on the bleaching gels used (Pola Office +37.5% [PO+] and Whiteness HP Automixx Plus 35% [AM+]) and the mixing tip types (T-Mixer and Helical). A negative control group was treated with ultra-purified water. HP concentration was measured using UV-Vis, and CC was evaluated with a digital spectrophotometer. Initial concentration, pH, and viscosity were measured through Titration, a Digital pH meter, and Rheometer, respectively. MW and MU were measured using a precise analytical balance. Statistical analysis included two-way ANOVA, Tukey's, and Dunnett's test (α = 0.05). A higher HP concentration was observed with PO+ with the Helical mixing tip in comparison with AM+ (p = 0.01). No significant differences in CC or MU were found for different mixing tips (p = 0.001). The T-mixer mixing tip resulted in significantly less MW (p < 0.00001) and improved mixture homogeneity and viscosity. Utilizing a T-mixer with self-mixing bleaching gels achieves comparable CC while reducing MW. Moreover, it decreases HP penetration when using PO+. For the application of a self-mixing in-office bleaching gel, a T-mixer mixing tip should be recommended, as it reduces the penetration of hydrogen peroxide into the pulp chamber when using PO+, while also minimizing gel wastage.

Impact of Six Extraction Methods on Molecular Composition and Antioxidant Activity of Polysaccharides from Young Hulless Barley Leaves.

Young hulless barley leaves are gaining recognition for potential health benefits, and the method of extracting polysaccharides from them is critical for potential food industry applications. This study delves into a comparative analysis of six distinct fiber extraction techniques: hot water extraction; high-pressure steam extraction; alkaline extraction; xylanase extraction; cellulase extraction; and combined xylanase and cellulase extraction. This analysis included a thorough comparison of polysaccharide-monosaccharide composition, structural properties, antioxidant activities (DPPH, ABTS, and FRAP), and rheological properties among fibers extracted using these methods. The results underscore that the combined enzymatic extraction method yielded the highest extraction yield (22.63%), while the rest of the methods yielded reasonable yields (~20%), except for hot water extraction (4.11%). Monosaccharide composition exhibited divergence across methods; alkaline extraction yielded a high abundance of xylose residues, whereas the three enzymatic methods demonstrated elevated galactose components. The extracted crude polysaccharides exhibited relatively low molecular weights, ranging from 5.919 × 104 Da to 3.773 × 105 Da across different extraction methods. Regarding antioxidant activities, alkaline extraction yielded the highest value in the ABTS assay, whereas enzymatically extracted polysaccharides, despite higher yield, demonstrated lower antioxidant capacity. In addition, enzymatically extracted polysaccharides exerted stronger shear thinning behavior and higher initial viscosity.

Investigation of flocculation and rheological properties of microalgae suspensions cultivated in industrial process wastewater

Microalgae harvesting at an industrial scale remains a techno-economic bottleneck for large-scale microalgae production that can account for up to 30% of the total cost ofbiomass production. A wide range of harvesting techniques have been applied commercially, among which, coagulation-flocculation techniques prove to be both convenient and cost-effective as pre-treatment techniques used in conjunction with other methods. In this study, process wastewater acquired from onshore natural gas facilities in Qatar was utilized to cultivate freshwater microalgae specie Scenedesmus sp. for simultaneous pollution abatement and biomass harvesting applications. Scenedesmus sp. was cultivated in two growth phases (fast and slow growth phases) to examine the influence of the microalgae growth phase on the flocculation process and rheological behavior. Effective flocculation was achieved using a commercial high charge density and high molecular weight cationic polyacrylamide-based flocculant. Flocculation efficiencies exceeded 97% for both fast and slow growth phase suspensions at an optimum flocculant dose of 10 mg/L. Optimum conditions were well corroborated by residual turbidity and zeta potential measurements. For fast growth phase suspensions, the optimum PAM dose coincided with a minimum residual turbidity of 2.35 NTU and a zeta potential of −0.52 mV. Similarly, the optimum PAM dose was fixed based on a minimum residual turbidity of 2.30 NTU and a zeta potential of +0.63 mV for slow growth phase suspensions. Large, easily settleable and compact flocs were obtained with average D50 values of 70.7 μm and 142.0 μm recorded for fast and slow growth phase suspensions, respectively, at optimum PAM dose. Moreover, based on rheological characterization studies, the flocculated suspensions demonstrated an overall non-Newtonian pseudoplastic (shear thinning) fluid behavior. Introduction of cationic PAM significantly improved the viscosity and yield stress of the flocculated suspensions around the optimum PAM dose range. At the optimum PAM dose, the initial viscosities were recorded as 10.37 and 39.19 mPa.s with yield stresses of 12.84 and 16.59 N/m2 for fast and slow growth phase suspensions, respectively. The flocculated biomass further displayed a viscoelastic solid (gel) behavior, characterized by high gel strength and resistance to shearing around optimum flocculant doses. At the optimum PAM dose, the storage moduli were recorded as 886.2 and 1068.6 mPa for fast and slow growth phase suspensions, respectively.

An inflationary disk phase to explain extended protoplanetary dust disks

Context. Understanding planetesimal formation is an essential first step towards understanding planet formation. The distribution of these first solid bodies drives the locations where planetary embryos, which eventually form fully-fledged planets, grow. Aims. We seek to understand the parameter space of possible protoplanetary disk formation and evolution models of our Solar System. A good protoplanetary disk scenario for the Solar System must meet at least the following three criteria: (1) It must produce an extended gas and dust disk (e.g. 45 au for the dust); (2) within the disk, the local dust-to-gas ratio in at least two distinct locations must sufficiently increase to explain the early formation of the parent bodies of non-carbonaceous and carbonaceous iron meteorites; and (3) dust particles, which have condensed at high temperatures (i.e. calcium–aluminium-rich inclusions), must be transported to the outer disk. Though current protoplanetary disk models are able to satisfy one or two of these criteria, none have been successful in recreating all three. We aim to find scenarios that satisfy all three. Methods. In this study we used a 1D disk model that tracks the evolution of the gas and dust disks. Planetesimals are formed within the disk at locations where the streaming instability can be triggered. We explored a large parameter space to study the effect of the disk viscosity, the timescale of infall of material into the disk, the distance within which material is deposited into the disk, and the fragmentation threshold of dust particles. Results. We find that scenarios with a large initial disk viscosity (α &gt; 0.05), a relatively short infall timescale (Tinfall &lt; 100–200kyr), and a small centrifugal radius (RC ~ 0.4 au; i.e. the distance within which material falls into the disk) result in disks that satisfy all three criteria needed to represent the protoplanetary disk of the Solar System. The large initial viscosity and short infall timescale result in a rapid initial expansion of the disk, which we dub the ‘inflationary phase’ of the disk. Furthermore, a temperature-dependent fragmentation threshold, which accounts for cold icy particles breaking more easily, results in larger and more massive disks. This, in turn, results in more ‘icy’ than ‘rocky’ planetesimals. Such scenarios are also better in line with our Solar System, which has small terrestrial planets and massive giant planet cores. Finally, we find that scenarios with large RC cannot transport calcium–aluminium-rich inclusions to the outer disk and do not produce planetesimals at two locations within the disk.

Tuning pharmaceutically active zein-based formulations for additive manufacturing

Zein, a biopolymer from corn, was plasticized by glycerol and an Active Pharmaceutical Ingredient-Ionic Liquid (API-IL) for its melt processing at 130 °C. In order to enhance the rheological properties of the formulation for 3D printing, the ratio of glycerol to API-IL was adjusted while maintaining a consistent addition of 20% plasticizer. A 50/50 ratio allowed obtaining an initial melt viscosity suitable for extrusion-based processes, at approximately 1 kPa.s at a shear rate of 10 s−1, with a shear thinning behavior. This viscosity remained stable during a processing window of about 6 min, before zein proteins start to aggregate, leading to an apparent gelation phenomenon for long residence times. The processability of this formulation containing API-IL for the printing of tablets for potential therapeutic applications was confirmed by tests on a 3D printer. Nonetheless, in comparison to a reference formulation containing only glycerol, the printing accuracy experienced a decrease. This was ascribed to slower viscous sintering kinetics in presence of API-IL, evidenced by monitoring fusion-bonding during dynamic X-ray tomography trials carried out at Synchrotron SOLEIL.

Bleaching Gels Used After 1 Week of Mixing: Efficacy, Hydrogen Peroxide Penetration, and Physical-chemical Properties.

This in vitro study aimed to evaluate the bleaching efficacy (BE), hydrogen peroxide penetration into the pulp chamber (HPP), and physical-chemical properties (concentration, pH, and viscosity) of in-office bleaching gels immediately and after 1 week of mixing. We randomly divided 49 premolars into seven groups: control (no bleaching) and the following in-office bleaching (Opalescence Boost 40%, Total Blanc One Step 35%, and Whiteness HP Blue 35%) applied at two storage times: immediately and after 1 week. We evaluated the BE using a digital spectrophotometer and the HPP through UV-Vis spectroscopy. We measured the initial concentration, pH, and viscosity using titration, a Digital pH meter and Rheometer, respectively. For statistical analysis, we used a twoway analysis of variance and Tukey and Dunnet tests (α=0.05). We observed higher BE and HPP for Opalescence Boost and Total Blanc One Step after 1 week of mixing than for Whiteness HP Blue (p<0.001). We observed a significantly lower initial concentration for Whiteness HP Blue 1 week after mixing compared to immediately (p=0.00001). All bleaching gels showed a decrease in pH after 1 week of mixing (p=0.00003). However, Total Blanc One Step had a lower pH at both evaluation times (p<0.001). Only Opalescence Boost maintained viscosity 1 week after mixing. Opalescence Boost was the only bleaching gel able to keep bleaching efficacy, with the same characteristics of permeability and physical- chemical properties after 1 week of mixing.

Rheological and tribological properties of high internal phase emulsions stabilized by pH-induced soy protein isolate-carrageenan complex coacervates

Coacervates of protein-polysaccharide complexes that self-assemble through electrostatic interactions exhibit varying morphologies and functional properties. This study investigated the pH range of soy protein isolate (SPI) and κ-carrageenan (κCG) to form complex coacervates in different states and their ability to stabilize high internal phase emulsions (HIPEs). With the increase of pH (from 4.0 to 5.5), electrostatic interaction between SPI and κCG weakened, the yield of SPI/κCG complex coacervates in the system as well as the degree of agglomeration of microstructure gradually decreased. However, in terms of HIPEs, pH5.0 and pH5.5 (especially pH5.5) complex coacervates exhibited better HIPEs formation ability. Excessively complex coacervates could seriously reduce the adsorption rearrangement rate and intermolecular crosslinking behavior of protein molecules at the interface, so the pH5.5 sample with the lowest coacervates yield showed smaller droplet size and higher elastic modulus. The pH5.0 sample exhibited higher initial viscosity in rheological tests, better deformation resistance in large amplitude oscillatory shear (LAOS) tests and better oral friction properties, due to higher complexation degree of coacervates. These findings give improved understandings of structure of pH-induced SPI-κCG complex coacervates in relation to their ability to stabilize HIPEs, which can guide for design of food emulsions.

Development and performance characterization of a composite grouting material suitable for sealing and reinforcement of microcracked mudstone

Micro-pore grouting consolidation constitutes a pivotal technical solution for addressing the issue of water-related weakening in mudstone. Given the engineering challenges such as the sub-optimal injectability of cement slurry materials into mudstone, and the deficient reinforcement strength of silica sol in the same, this study provisionally developed a composite grouting material with a multi-particle size distribution, which is suited for the closure and reinforcement of microcracks in mudstone. We characterized the fundamental solidification and grouting properties of the modified composite grouting material, and unveiled the reinforcement mechanism of aluminate cement (AC) modified silica sol. The research findings indicate that the composite grouting material exhibits a two-tiered advantageous particle size distribution at the nanometer and micrometer levels, resulting in a marked enhancement in injectability. When the quantity of AC is 50% of the silica sol mass, and the water-cement ratio of cement slurry is 0.6, the solidification time of the composite grouting material can be adjusted between 21 and 114.5 mins. The initial viscosity is less than 5 mPa·s, and the stone rate exceeds 97%. The 28-day cemented structure exhibits a volume shrinkage rate of merely 0.57%, and the compressive strength can attain 14.5 MPa. In terms of the modification mechanism, SiO2 nanoparticles effectively expedite the hydration process of AC within the composite grouting material, engendering chemical bonds in the hydration products. These fill the pre-existing pores of the cement cemented structure, thereby enhancing the mechanical strength and compactness of the internal structure of the composite grouting material cemented structure.

Influence of the nature and concentration of alkali cations in silicate solutions on the behavior of MK-CaCO3 based geopolymers at 600–1150 °C

The objective of this work is to study the effect of the nature (potassium or a mixture of potassium and sodium) and concentration of alkali cations on the behavior of geopolymers at a high temperature (1150 °C). First, the physico-chemical characteristics of the different geopolymers, such as the initial viscosity, the density of the mixture and structural data (Raman spectroscopy), are presented. Then, thermal analysis, dilatometry and mercury porosity are conducted, as well as the mechanical behavior and X-ray diffraction after 1150 °C. The different formulations display different trends depending on the concentration and the nature of the alkaline cations. In comparison to the use of a potassium cation, the addition of sodium leads to an increase of the viscosity and a decrease of the onset temperature of the viscous flow. The potassium-based formulations show better behavior after treatment at high temperature (1150 °C). The improvement in the mechanical properties after thermal treatment is controlled by the different crystalline phases formed, such as leucite and anorthite.

Laboratory studies of the feasibility for microencapsulated polymer flooding

Conventional polymer flooding faces challenges in terms of injection difficulty and shear degradation when applied in medium- and low-permeability reservoirs. Microencapsulated polymer flooding, as a promising method for enhancing polymer flooding, involves encapsulating the polymer within microcapsules to resist shear and improve the injectivity. In this study, we conducted a series of experiments to explore the fundamental properties of thermo-sensitive microencapsulated polymer, including dispersion stability, injection, shear resistance and viscosity enhancement. The experimental results show that the microencapsulated polymer is a spherical particle with core-shell structure, which is easy to disperse and has good stability. The microcapsule size is from 0.1 μm to 1 μm, making it to be better injected into formations. The microcapsule shell has excellent shear resistance, that after undergoing high-speed mechanical shearing, the trigger viscosity of the microencapsulated polymer can still reach 97.4% of the initial viscosity. Thickening experiments show that the microencapsulated polymer has a delayed thickening property in the range of 50-90℃, and it can be released inside the core, resulting in higher flow resistance. This study provides a more detailed evaluation of the application potential of microencapsulated polymer, which proves that the microencapsulated polymer flooding is a feasible and powerful technology for EOR.

Retarding thermal-oxidative aging of anhydride-cured epoxy asphalt binder and mixture by incorporating antioxidant Irganox 1010

ABSTRACT This research focused on the stabilisation of anhydride-cured epoxy asphalt (EA) over thermal-oxidative aging. EA binders with graduated Irganox 1010 antioxidant contents at 0, 0.3, 0.6, 0.9, and 1.2 wt% were prepared and then subjected to accelerated oven-conditioning aging at 85 and 100°C. The thermal stability, viscosity, mechanical parameters, and chemical structure of EA containing Irganox 1010 were evaluated during aging. The results showed that Irganox 1010 contributed to enhanced thermal stability, higher initial viscosity, and longer allowable construction time for EA. The 0.3–0.9 wt% Irganox 1010 had good compatibility with EA without weakening performance. During aging, Irganox 1010 effectively restrained degradation of the EA binder’s mechanical properties and the EA mixture’s low-temperature deformation. The variations of functional groups indicate that Irganox 1010 prominently restrained the oxidation of the asphalt phase and lightly affected the post-curing of the resin phase. There was a strong correlation between decreasing rate of bending strain of the mixture and increasing rate of sulfoxide in the binder. The mutual synergistic effect of resin and antioxidant improves the oxidation resistance of asphalt. Considering the aging improvement and economic cost, it is recommended to use 0.6 wt% Irganox 1010 as an antioxidant for anhydride-cured EA. Highlights Epoxy asphalt (EA) binder and mixtures incorporating antioxidant Irganox 1010 were analysed. Irganox 1010 plays a crucial role in aging protection effect of EA binder and mixture. Irganox 1010 antioxidant prominently restrains the oxidation of the asphalt phase and lightly affects the post-curing of the resin phase. There was a strong correlation between the bending strain of mixture and sulfoxide of binder. Addition of 0.6 wt% Irganox 1010 is recommended as an antioxidant for EA materials.

Determination of the Binary Diffusion Coefficients and Interaction Viscosities of the Systems Carbon Dioxide–Nitrogen and Ethane–Methane in the Dilute Gas Phase from Accurate Experimental Viscosity Data Using the Kinetic Theory of Gases

The results of viscosity measurements at moderate densities on the two gaseous mixtures carbon dioxide–nitrogen and ethane–methane including the pure gases between 253.15 K and 473.15 K, originally performed by Humberg et al. at Ruhr University Bochum, Germany, using a rotating-cylinder viscometer between 0.1 MPa and 2.0 MPa, were employed to determine the interaction viscosity, eta _{12}^{(0)}, and the product of molar density and diffusion coefficient, (rho D_{12})^{(0)}, each in the limit of zero density. The isothermal viscosity data were evaluated by those authors with density series restricted to the second order at most to derive the zero-density viscosities and initial density viscosity coefficients, eta _textrm{mix}^{(0)} and eta _textrm{mix}^{(1)}, for the mixtures, as well as, eta _i^{(0)} and eta _i^{(1)} (i=1,2), respectively, for the pure gases. Humberg et al. have already compared their eta _textrm{mix}^{(0)} and eta _i^{(0)} data for carbon dioxide–nitrogen and ethane–methane with corresponding viscosity values theoretically computed for the nonspherical potentials of the intermolecular interaction. Now we employed eta _textrm{mix}^{(0)} and eta _textrm{mix}^{(1)} as well as eta _i^{(0)} and eta _i^{(1)} in two procedures to derive eta _{12}^{(0)} values. For this, we needed A_{12}^* values (ratio between effective cross-sections of viscosity and diffusion). But the second procedure applying the initial density viscosity coefficients eta _textrm{mix}^{(1)} and eta _i^{(1)} failed to yield reasonable eta _{12}^{(0)} values. The first procedure should provide the best results when it is possible to use A_{12}^* values computed for the nonspherical potential. The effect is comparatively small if eta _{12}^{(0)} is determined. But if (rho D_{12})^{(0)} is calculated from eta _{12}^{(0)} using A_{12}^* values for the nonspherical potential, the impact is several percent. Moreover, the experimentally based eta _{12}^{(0)} and (rho D_{12})^{(0)} data agree with theoretically calculated values for the nonspherical potentials.

Assessment of the enhancement potential of salicylic acid on physicochemical, mechanical, barrier, and biodegradability features of potato starch films

Filmogenic suspensions based on starch (S) and salicylic acid/starch (SA-S) were prepared and used to produce casted films (TPS and SA-TPS). An extensive characterization was conducted on both suspensions and casted films to assess their properties. Results evidenced that after storage for 120 days at 4 °C and 25 °C, the mold and yeast counts were significantly lower in the SA-S than in the S suspensions. Moreover, SA-S had a much lower initial viscosity than S. In reference to the films produced, salicylic acid caused a significant increase in film crystallinity, as well as a 2.3-fold increase in stress at break and a 3.8-fold increase in Young's modulus over the control films. Additionally, compared to TPS, the SA-TPS films exhibited a 46% decrease in water vapor permeability. All films showed a high biodegradation extent (≥85%) upon 75 days of home composting. These findings suggest that the salicylic acid addition at low concentrations (2 mM) can be a cost-effective approach for the development of highly stable starch filmogenic suspensions and also biobased films with distinguishing properties.

INFLUENCE OF ELECTROCHEMICALLY ACTIVATED WATER ON THE FUNCTIONAL AND TECHNOLOGICAL PROPERTIES AND RHEOLOGICAL INDICATORS OF MEAT PATES

Preparation of water for food production, as components for increasing the biological integrity of food products by optimizing the content of macro- and microelements with biogenic properties in water, is an urgent issue in solving the problems of water preparation and determining the parameters of this process to ensure the structuring of food systems. The influence of activated water in the composition of starch suspensions on the functional and technological properties and rheological indicators of pates using them was determined. Activated water, and to a greater extent anolyte, significantly affects the moisture-binding capacity of pates. It was confirmed that samples of pates with a starch suspension with 2% starch on activated water demonstrate an increase in this indicator: on the anolyte and catholyte, the moisture-binding capacity of the pates in relation to the weight of the sample increased by 32.39% and 2.41% before pasteurization, compared to the control sample and by 33.05% and 1.71% after pasteurization. In the samples on the anolyte, the achievement of the maximum value of the indicator 100% is observed both before and after pasteurization. In the case of pates with 5% starch, the trend is similar. The indicator of the moisture-binding capacity of pates in relation to the mass of moisture in samples with a starch suspension with 2% starch on the anolyte increased by 3.71% before pasteurization, compared to the control sample, and on the catholyte it practically did not change. The values of this indicator in all samples after pasteurization were in the range of 90-100%. It was shown that the rheological parameters, namely the shear stress value of all pate samples regardless of the dosage of starch suspension in the range of shear rate - 0-8 s-1, increased sharply, after which the curves changed their character. In samples with a suspension of 2% starch, the indicator decreased linearly, while the catholyte has a smaller effect on the change in shear stress. When adding suspension with 2% starch at zero shear rate, the initial shear viscosity of pates was higher than in the sample with 5% and the control sample. So, activated water in the composition of corn starch suspensions helps to change the functional and technological properties and rheological indicators of pates with their content, which in turn will be reflected in the consistency of meat pates.

Numerical study of the geometric characteristics and kinetic behavior of single bubble rise processes in different liquids

The characterization of single bubble in gas–liquid two phase flow is a critical yet unresolved issue in both science and industry. In this study, the volume-of-fluid (VOF) method is used to numerically simulate and experimentally investigate the effect of initial bubble diameter, liquid viscosity, and surface tension on bubble deformation and the internal flow field of the bubble in a pool of stationary liquid. The findings indicate that as liquid viscosity increases, the bubble's rising speed decreases, and the bubble tends to oscillate. The variation in bubble deformation ratio and the degree of fluctuation increase with the bubble's initial diameter and decrease with the viscosity of the liquid phase. Additionally, as the surface tension of the liquid decreases, the bubble becomes more prone to rupture, and the number of ruptures increases. The flow field inside the bubble can be classified into three categories: “double main vortex type,” “double main vortex type with separated vortex,” and “double main vortex type with scattered vortex.” The velocity reaches its maximum at the center of each vortex type, and the velocity at the interface varies as the bubble interface shape changes. This work lays the foundation for the study of the flow field inside the bubble and improves the predictability of gas–liquid equipment design.

Dynamic mechanism of double emulsion droplets flowing through a microfluidic T-junction

A microfluidic chip is adopted to study the droplet dynamic behaviors when flowing through the T-junction. Large ranges of initial length (Lo/w = 0.8–2.8), capillary number (Cao = 0.030–0.165), and viscosity ratio (λo = 0.16–5.90) are considered to identify the deformation characteristics and the breakup results. Three flow patterns are categorized in the T-junction, and critical conditions are expressed as power law relations between the normalized length and the capillary number. The coupling competition exists between outer neck thinning and inner droplet shifting, which influences the deformation process. A state diagram indicating the number of breakups is built through two key features of the shifting behavior, namely, the shifting distance and the shifting velocity. With increasing viscosity ratio, thresholds of both breakups decrease due to the reduced deformation resistance caused by vortex flow and the weakened coupling effect, resulting from the suppressed shifting behavior. The shell thickness via twice-breakup pattern depends solely on the viscosity ratio.

Rheological behavior and microstructural properties of crude oil and emulsions (water/oil-oil/water)

An experimental study on crude oil (from the Tin Fouye Tabankort oil field in southern Algeria) was carried out. This study allowed us to understand the rheological behavior of this crude oil with these different emulsions and how it reacts under the effects of temperature and the inversion of its phase from E/H to H/E. So we measured the rheological characteristics by tests flow and dynamic mode at different temperatures from 10 °C to 50 °C and at different water concentrations (20.40.50.60 and 70%) at a fixed temperature of 20 °C. The increase in temperature results in a 31.84% reduction in the initial viscosity of the crude oil. The addition of the volumic fractions of water results in an increase in viscosity at the point of inverse, which will decrease the apparent viscosity of these emulsions where the emulsions (W/O) come from (O/W). This crude oil and their emulsions exhibit a non-Newtonian behavior with shear thinning. The dynamic analysis depends on the temperature and the percentages of water added to the crude oil. At the end, a microscopic analysis was added to verify the relationship between the shape and diameter of the water droplets in each emulsion and the viscosity variation.