Numerical Simulation of the Influence of Taylor Vortex on the Apparent Viscosity Measurement of Semi-Solid Metallic Based On ANSYS Fluent

The apparent viscosity of semi-solid metallic slurry with a low solid fraction, which is one of the most essential parameters for representing the rheological behavior, is mainly measured by the concentric cylinder rotational approach. The principle of this method is based on the assumptions that the fluid is in an ideal laminar flow state and obey the Newton’s internal friction law. However, as the angular velocity ω increases, the fluid undergoes a transition from a stable laminar flow state to a Taylor vortex and turbulent flow state. These unstable flow conditions such as Taylor vortex and turbulence have a severe impact on the accuracy of apparent viscosity measurement. However, these unstable flow conditions are difficult to monitored and analyzed in real time through experimental methods. Computer numerical simulation technology provides the possibility and convenience for the visualization of the flow state of the semi-solid metallic slurry in the measurement system. In this work, ANSYS Fluent was used to simulate the apparent viscosity measurement process of semi-solid slurry, and the flow state transition process of the semi-solid slurry in the measurement system was successfully visualized and analyzed. In order to avoid the influence of Taylor vortex, combined with the measurement principle of the concentric cylinder rotational rheometer and Taylor’s study on flow stability, the empirical equation of limiting speed to avoid Taylor vortex in the process of Searle rheometer viscosity measurement is given.

Interaction of surfactants with poloxamers 338 and its effect on some properties of cream base

The aim. Study of the interaction of surfactants with poloxamer 338 (P338) and the effect of P338 on the properties of cream bases. Materials and methods. Solutions of the surfactants and P338 as well as cream bases were under study. The average hydrodynamic diameter (Dh) and zeta potential (ζ‑potential) were determined by the light scattering intensity and electrophoretic mobility of micelles. The electron paramagnetic resonance (EPR) spectra of spin probes in micelles, solvents and bases were obtained; the type of spectrum, isotropic constant (AN), rotational correlation times (τ) and anisotropy parameter (ε) were determined. Liquids and cream bases were studied by capillary and rotational viscometry; the flow behaviour and yield stress (t0), dynamic and apparent viscosity (η) as well as the hysteresis (thixotropic) area (AH) were determined. The microstructure of the bases was examined by optical microscopy. The strength of adhesion (Sm) was assessed by the pull-off test, and the absorption of water was studied by dialysis. Results. Under the impact of P338 the hydrodynamic diameters of micelles formed by cationic, anionic and nonionic surfactants decreased as well as the absolute values of their ζ‑potential became lower, but the microviscosity of the micelle nuclei increased. There was also a change in the structure of the aggregates of surfactant with fatty alcohols; EPR spectra, which were superpositions characteristic for the lateral phase separation, converted into triplets that indicated the uniform distribution of lipophilic probes in the surfactant phase. When the content of P338 increased to 17 %, the rheological parameters of the bases increased drastically, the flow behaviour and the microstructure changed. The bases had the consistency of cream within temperature range from 25 °C to 70 °C and completely restored their apparent viscosity, which had decreased under shear stress. P338 enhances the adhesive properties of the bases. Due to their microstructure, cream bases have a lower ability to absorb water compared to a solution and gel containing 17 % and 20 % P338, respectively. Conclusions. The structure of surfactant micelles and aggregates of surfactants with fatty alcohols changed under impact of P338 due to the interaction of surfactants with P338. As a result of this interaction, at a sufficiently high concentration of P338, the microstructure and flow behaviour of bases changed, their rheological parameters, which remain high at temperatures from 25 °C to 70 °C, increased significantly, and water absorption parameters decreased. The bases with P338 were more adhesive

Comparison of sensory and rheological properties of green cosmetic creams prepared on different natural, ECOCERT and BDIH certificated self-emulsifying bases

The objective of this paper was to evaluate and compare the rheological and sensory properties of six natural cosmetic creams that use ECOCERT certificated emulsifying bases: Beautyderm, Dub Base Expert, Simulgreen™ 18-2, Olivem 1000, Montanov L and Emulgin Succro against two synthetics: Granthix APP and Lanette W. The use of emulsifying bases in formulas helps to stabilize the product and improve its rheological and sensory attributes. In this study, the physical and chemical properties of several prepared cosmetic creams were determined. Apparent viscosity and thixotropy were evaluated by viscosimeter, while spreadability was ascertained by extensometer. Moreover, a group of 10 trained members evaluated the sensory properties of the formulas. The obtained formulas based upon natural emulsifiers are characterized by very good physical and chemical properties, high stabilization and good usage quality. The results were confirmed by sensory analysis. The cosmetic creams made with synthetic emulsifying bases were rated the worst by the study participants, which correlated with the physical tests.

Improving the rheological properties of water-based calcium bentonite drilling fluids using water-soluble polymers in high temperature applications

Most of bentonite used in modern drilling engineering is physically and chemically modified calcium bentonite. However, with the increase of drilling depth, the bottom hole temperature may reach 180 °C, thus a large amount of calcium bentonite used in the drilling fluid will be unstable. This paper covers three kinds of calcium bentonite with poor rheological properties at high temperature, such as apparent viscosity is greater than 45 mPa·s or less than 10 mPa·s, API filtration loss is greater than 25 mL/30 min, which are diluted type, shear thickening type and low-shear type, these defects will make the rheological properties of drilling fluid worse. The difference is attributed to bentonite mineral composition, such as montmorillonite with good hydration expansion performance. By adding three kinds of heat-resistant water-soluble copolymers Na-HPAN (hydrolyzed polyacrylonitrile sodium), PAS (polycarboxylate salt) and SMP (sulfomethyl phenolic resin), the rheological properties of calcium bentonite drilling fluids can be significantly improved. For example, the addition of 0.1 wt% Na-HPAN and 0.1 wt% PAS increased the apparent viscosity of the XZJ calcium bentonite suspension from 4.5 to 19.5 mPa·s at 180 °C, and the filtration loss also decreased from 20.2 to 17.8 mL.

Evaluation of In-Situ Generation of Nitrogen Gas for Foam Applications using Two Salt Solutions

Foams are used in many oil and gas applications including conformance control during EOR processes, fracturing, and acidizing operations. Foams are defined as dispersions of gas bubbles into a continuous liquid phase. Typically, foams are generated when an injection gas such as nitrogen, carbon dioxide, or flue gas is mixed with an injection fluid containing a foaming agent. This method, however, requires a gas source to be present for foams to be generated. The objective of this study is to evaluate a new alternative technique for foam generation using two salt solutions. Nitrogen gas is generated as a result of the reaction of the two salt solutions at specific conditions. This generated nitrogen gas is then used for foam generation in porous media. The foam generated using the two salt solutions is tested in a microfluidic device (rock-on-a-chip) to study the gas mobility reduction in porous media. A Foam rheometer apparatus is also used to measure foam apparent viscosity when the two salt solutions are mixed with a foaming agent. The results are compared with those obtained when nitrogen gas is injected into the system independently in the absence of the two salt solutions. Results reveal that the amount of added salts significantly impact the produced nitrogen volume. Additionally, the test conditions especially the temperature, significantly impacts the reaction rate. The rate of nitrogen gas generation is directly proportional to the temperature when tested at 25-80°C. In addition, experiments demonstrate that the foams generated using the two salt solutions reaction have almost identical characteristics as those produced when nitrogen gas is injected into the foam rheometer apparatus independently. Both methods generate the same foams with comparable foam apparent viscosity. In the microfluidic system, the foam obtained using the two salt solutions in the presence of a foaming agent shows excellent resistance to gas flow and subsequently exhibit large gas mobility reduction. This experimental study, for the first time, confirms the ability of the two salt solutions reaction to generate nitrogen gas spontaneously upon contact under certain conditions. The generated gas is used to generate foams in the presence of a foaming agent. This newly proposed technique of foam generation could significantly impact many oil and gas operations including conformance control during EOR processes, fracturing, and acid stimulation operations.

The influence of the introduction of rice bran on fermented milk drink

Rice bran is an agro-industrial waste with excellent nutritional value and a considerable content of bioactive compounds. Biotransformation processes by fermented milk drink fermentation increase the interest in obtaining products from agro-industrial wastes with good biological properties. The viability of introducing rice bran (RB) into fermented milk drinks to improve the structural stability and sensory was studied. Fermented milk drink supplemented with 0, 0.1 %, 0.3 %, 0.5 %, 0.7 % amount of RB were studied. Samples were stored for 28 days at 4 ± 1 °C. Samples composition was studied, Physicochemical properties (total titratable acidity, apparent viscosity, and pH) and consumer’s acceptability of fermented milk drinks were determined at 0, 7th, 14th, 21th and 28th days of storage. Studies showed that rice bran wan rich in dietary fiber (28.57 %), fat (21.56 %), and protein (11.18 %). The introduction of RB showed a significant influence on these parameters (P < 0.05). The introduction of RB would significantly improve the value of titratable acidity and apparent viscosity and decrease pH value. The more rice bran was added, the higher the values of titratable acidity and apparent viscosity were. The lower the pH value was, which could shorten the fermentation time, improve the texture stability, save production cost. The storage period could significantly influence the value of titratable acidity, pH, and apparent viscosity. The longer the storage period was, the higher the titratable acidity values were, the lower the pH value was caused by the post-fermentation of fermented milk drink. The apparent viscosity showed a trend of rising first and falling then during the storage period. The introduction of RB could significantly influence the sensory characteristic (color, consistency, sour, and texture). The introduction of RB would lead to whey separation and rough structure. Fermented milk drink supplemented with 0.1 % RB showed higher sensory acceptance. The best shelf life of the sample is 14 days，during which time fermented milk drink was of the best quality. RB is a kind of raw material with bright application prospects in a fermented milk drink.

INFLUENCE OF OLIVE OIL ON THE RHEOLOGICAL CHARACTERISTICS OF MAYONNAISE

Rheological properties are an important parameter for the quality of mayonnaise. This article in-vestigated the effect of adding olive oil on the rheological properties and color change of mayon-naise. The influence of the storage time of mayonnaise in the refrigerator on the change in rheo-logical properties was also investigated. Mayonnaise was prepared on a laboratory rotary disperser of the Turrex type with a rotor / stator system with a rotor speed range (10000-30000 rpm) at room temperature. Mayonnaise contains 75% oil with varying proportions of sunflower oil and ol-ive oil. Rheological measurements were carried out on a Brookfield rotary viscometer with con-centric cylinders at temperatures of 10 ° C and 25 ° C. Based on the data obtained, the consistency coefficient of the rheological parameters, the flow index and the apparent viscosity were calculat-ed. The color of the test samples of mayonnaise was measured using a three-color colorimeter. All mayonnaise samples exhibit non-Newtonian pseudoplastic flow with a defined thixotropic loop area. Research results have shown that the addition of olive oil affects the rheological properties and color of mayonnaise. The addition of olive oil to the oil phase of mayonnaise reduces shear stress, apparent viscosity, consistency factor and color change at 25 ° C and 10 ° C. When storing mayonnaise in the refrigerator for 15 days, the rheological parameters change. Sunflower oil may-onnaise (75%) has the highest value (L), which means it is measured instrumentally as the bright-est.

Effect of grasshopper (Sphenarium purpurascens Charpentier) paste addition on rheological behavior of Mole Poblano

Objective: Analyze the effect of grasshopper (Sphenarium purpurascens Charpentier) paste addition on the rheological behavior of Mole Poblano (MP) and its relation with the technological properties of the grasshopper paste. Design/methodology/approach: The addition of grasshopper paste was done at different proportions as follows: T0= 0% of grasshopper paste (GP) and 100% of mole Poblano (MP); T10=10% GP and 90% MP; T15=15% GP and 85% MP, T20=20% GP and 80% MP, T25=25% GP and 75 % MP, T30=30% GP and 70% MP. Water retention and emulsifying capacity of grasshopper paste were evaluated. Density, kinematic and apparent viscosity, and rheological behavior were analyzed at 25ºC; rheological parameters (consistency index (k) and flow behavior index (n)) were calculated by performing a regression analysis to adjust the graphs to a power-law model. Findings/conclusion: Grasshopper paste had higher emulsifying capability than water retention capability. Apparent viscosity of all formulations decreased as shear rate increased, so all mixtures of GP and MP demonstrated No-Newtonian behavior and pseudoplastic performance. Index consistency increased as GP content increased, these results are related with protein content because GP had a good emulsifying capability. Limitations on study/implications: More studies about the characterization of the proteins of GP and their interaction with other components are required.