Values Of Rheological Parameters Research Articles

Dual modification of starch: Synergistic effects of ozonation and pulsed electric fields on structural, rheological, and functional attributes

Study evaluated the influence of ozonization (O3) time combined with pulsed electric fields (PEF) on the modification of bean starch structure. O₃ was used at a concentration of 0.045 g/L for 60 min (Oz1) and 120 min (Oz2) both individually and in combination with 30 kV/cm (P30). Carbonyl content was higher than the carboxyl content, especially with prolonged treatment times (Oz2), indicating partial oxidation. Additionally, higher levels of amylose and degrees of polymerization (DP ≥ 37 and DP 25–36) were observed in the oxidized starches, with significant changes only when combined with PEF. The main morphological and structural modifications included the presence of agglomerates, partial gelatinization, reduced crystallinity, and lower IR1047/1022 in the granules treated with PEF + O3. Oxidized starches exhibited higher solubility, resulting in lower values for rheological parameters, with PEF + 2 h of O3 (Oz2P) standing out. It can be used as prebiotics, controlled release agents and a texturizer for gluten-free foods.

The Effect of Lower Limb Pressotherapy Treatment on Selected Rheological and Biochemical Indices of Blood in Young, Healthy Women.

Background: Intermittent pneumatic compression is a non-invasive therapeutic technique that has been gaining popularity in recent years due to its potential use in many areas of medicine. It can be successfully used alone or in combination with other therapeutic methods. The aim of this study was to investigate whether and how a series of pressotherapy treatments on the lower limbs affects the rheological properties of blood (blood count, red blood cell deformability and aggregation, and blood viscosity), lipid profile (total cholesterol, triglycerides, low-density lipoprotein, and high-density lipoprotein), and renal profile (urea, creatinine, and estimated glomerular filtration rate) in young, healthy women. Methods: The study group consisted of 15 healthy women aged 20-26 (22.5 ± 1.5), without chronic diseases and not practicing competitive sports. The participants underwent a series of 10 lower limb pressotherapy treatments. A single treatment lasted 30 min and each time the pressure used during the treatment was individually selected according to the participants' preference. The first blood test was performed a week before the treatments; the second on the day of the start of treatment, but before the pneumatic massage; the third after the completed series of pressotherapy treatments; and the fourth a week after the completed series of treatments. Results: In the conducted study, the analysis of the values of the complete blood count showed the following: a significant decrease in red blood cell count, hemoglobin, average hemoglobin concentration in erythrocytes, average red blood cell volume, average hemoglobin mass in red blood cells; a significant increase in average red blood cell volume; and an average hemoglobin mass in red blood cells. The analysis of the values of rheological parameters showed the following: a significant decrease in elongation indices 0.58, 1.13, 4.24, 15.95, 30.94, and 60.00; blood viscosity; the aggregation index; the degree of complete aggregation; and a significant increase in elongation indices 0.30, 1.13, 8.23, 30.94, 60.00; blood viscosity; the degree of complete aggregation; and the half-time of complete aggregation. A decrease in the concentration of low-density lipoprotein and high-density lipoprotein fractions was also noted. No significant changes were found in the values of total cholesterol and triglycerides, as well as in renal profile elements. Conclusions: The application of a series of 10 lower limb pressotherapy treatments has a beneficial effect, with a decrease in blood viscosity and the aggregation index, and an increase in the elongation index at shear stress from 0.30 [Pa] to 8.23 [Pa] in young, healthy women. A series of 10 lower limb pressotherapy treatments may affect the decrease in the values at high shear stress forces of 30.95 [Pa] and from 60.00 [Pa] in young, healthy women. The use of a series of 10 lower limb pressotherapy treatments increases the values of hemoglobin, the average red blood cell volume, and the average hemoglobin concentration in erythrocytes, and also reduces the values of red blood cell count, average hemoglobin mass in red blood cells and low-density lipoproteins and high-density lipoproteins in young, healthy women (it also does not cause any adverse changes). The use of pressotherapy on the lower limbs seems to be an effective element of the multi-component prevention of circulatory system diseases.

Mechanism study on rheological response of thermally pretreated waxy crude oil

Pre-heating treatment significantly influences the low-temperature flow characteristics of waxy crude oil, yet its underlying mechanism warrants further investigation. This study explores the effects of pre-heating temperatures (60–110 °C) on the rheological characteristics of waxy crude oil from Nanyang using 1H NMR, DSC, Microscopic Observation, and Rheological Property Test. Findings reveal that asphaltenes increasingly dissolve at the pre-heating temperature of 70 °C, improving their capacity to act as nucleation sites for wax crystals. Consequently, the wax appearance temperature (WAT) increases. Meanwhile, the rheological parameters of the crude oil decrease and wax crystals exhibit smaller and tighter rod-like structures. Further growing the pre-heating temperature to 80 °C induces a comprehensive effect: alterations in asphaltene polarity, hindrance of asphaltene aggregation by alkyl side chains, and self-aggregation of alkyl side chains. This results in decreased WAT, along with the lowest rheological parameter values, with wax crystals appearing as the smallest and tightest dot-like shapes. At 80 °C, the optimal ratio between asphaltene polarity and alkyl side chain characteristics promotes strong nucleation and co-crystallization between asphaltene and wax crystals, maximizing asphaltene's ability to enhance the crude oil's low-temperature flowability. However, as the pre-heating temperature continues to rise, WAT decreases slightly and the rheological response starts to deteriorate.

Конвективные режимы псевдопластической жидкости в квадратной полости при воздействии высокочастотных вибраций в условиях пониженной гравитации

In this paper, we investigate convective modes of pseudoplastic fluid in a square cavity with solid perfectly heat-conducting boundaries under reduced gravity. The cavity performs vertical linearly polarized high-frequency vibrations. Between the vertical walls of the cavity a temperature drop is prescribed in the direction perpendicular to vibrations and the field of gravity. The fluid rheology is described using the Williamson model. The problem is solved based on the averaged thermovibration convection equations for nonlinear viscous fluids. The vibration intensity is determined by the vibration parameter V, which is proportional to the ratio of the amplitude of the vibration acceleration to the free-fall acceleration and does not depend on the temperature difference. The problem is found to have two types of solutions, which we call Newtonian and non-Newtonian modes. These solutions correspond to different convective structures, for which the dependences of the maximum of the stream function and the Nusselt number on the Grashof number are derived. We use these dependences for determining at different values of rheological parameters the threshold values of the Grasgof numbers, corresponding to the change in the modes of stationary averaged convection and the critical Grasgof numbers, corresponding to the loss of stability of stationary averaged flow and the occurrence of oscillatory modes of averaged convection. The structures of different modes of averaged stationary and oscillatory convection are studied. The results obtained for the Newtonian mode have shown that at small values of the Grasgoff number, a slow one-vortex stationary convective flow is realized in the cavity. With increasing the Grasgoff number it transforms into a three-vortex flow. A further increase in the Grasgoff number results in the appearance of a four-vortex convective flow, which eventually transforms again into a three-vortex motion. At even greater Gr, the stationary averaged motion becomes unstable and the oscillatory modes appear in the cavity. For the non-Newtonian mode, a stationary convective flow is the basic flow pattern detected in the cavity; the oscillatory modes are not observed in the whole investigated range of the Grasgoff numbers.

Estimating the slip rate in the North Tabriz Fault using focal mechanism data and GPS velocity field

Abstract This study delves into slip distribution on the North Tabriz Fault (NTF), a critical aspect of seismic hazard analysis due to its proximity to the Tabriz metropolis. The study operates within a uniform elastic half-space, maintaining constant values for fault geometry and regional rheological parameters throughout the research. To calculate strain boundary conditions, permanent and periodic global positioning system (GPS) data from the northwest region were utilized. The fault was constrained perpendicularly while allowing tangential movement, facilitating the determination of its annual slip rate using the boundary element method, with the Okada analytical model serving as the fundamental solution. The findings underscore the intricate relationship between the fault’s slip rate and boundary conditions, revealing a predominant right-lateral strike-slip motion. The study offers two slip rate assessments, obtained through earthquake focal mechanisms and GPS velocity data, yielding values of 5 and 5.5 mm / year {\rm{mm}}/{\rm{year}} , respectively. Importantly, the alignment of these calculated slip rates with paleo-seismological data underscores the credibility of the results generated via the boundary element method, distinguishing it as a reliable approach when compared to other numerical and analytical techniques. This research provides valuable insights into the behavior and slip dynamics of the NTF, which is pivotal for assessing seismic risks.

Electro-rheological flow of seminal fluid (K-L MODEL) induced by movement of cilia in a circular conduit

The current study deals with the flow of seminal fluid through the ductus efferentes owing to electro-osmotic force and motion of cilia. The constitutive equation of semen liquid has been assumed to be described as a K-L (Kuang and Luo) fluid model. The main equations of the ciliary flow of K-L model are solved by considering the supremacy of viscous upshot over inertia influence assuming the state of long wave-length number. The analytic expressions for velocity profile, flow rate and flow impedance are derived. This is the first time to bring out to the lime light that the flow impedance is decreased and the plug core radius is enlarged with the introduction of electric force in the ciliary flow system. The effects of pertinent physiological parameters on the time-mean flow rates of rhesus monkey and human semen are thoroughly investigated. The computational mean flow rate's value over the period of time of the current mathematical model has been well matched with the corresponding experimentation values of the time-mean flow rates of rhesus monkey and humanoid semen in the path of generative and the vas deferens of the path of generative of male. Introduction of electric field into the flow ciliary system and the rheology of semen fluid described as K-L fluid model (for the values of rheological parameters of K-L fluid are considered) reduce the flow resistance, which in turn elevates the flow velocity of seminal fluid, which activates the significant and favorable changes for Oocytes getting fertilized within hours of ovulation by means of reasonable volume of semen transport into the female reproductive tract to partake a quick contact with cervical mucus and enter the cervix.

RHEOLOGICAL PROPERTIES OF SOILS OF DIFFERENT LAND USE IN THE SYKTYVKAR URBAN DISTRICT OF THE KOMI REPUBLIC

The mechanical characteristics of soils of the same genesis and different land use of Syktyvkar are studied: agrod- ernovo-podzolic urban-stratified soil within the city, post-frost park soil, podzolic soil of suburban territory. The analysis of their relationship with the content of organic matter and granulometric composition is carried out. In agrodern-podzolic urban-stratified soil, the strength properties are largely due to the content of large granulometric fractions (> 0.25 mm), and in podzolic soil - the content of organic matter. Rows of soils were built according to the values of rheological parameters. The strength of structural bonds, estimated by the parameter of the initial modulus of elasticity, is greatest in podzolic soil, a wide range of linear viscoelastic state distinguishes the horizons of agroderno-podzolic urban-stratified soil. Both post-frost and podzolic soil have the same average values of the starting point of the viscous flow region.

Rheological study of highly concentrated aqueous graphene oxide suspensions: the effects of concentration, particle lateral dimensions and number of layers per particle

Aqueous graphene oxide (GO) suspensions have attracted considerable attention due to their unique properties, which can find numerous applications in various fields, from industry to biomedicine. When designing a GO hydrogel for a specific application, a thorough understanding of the effects of appropriate starting material properties and its concentration range on the suspension stability, structural and rheological properties is of essential importance. The present work is concerned with high solids content (from 1.00 to 2.00 w/v%) GO aqueous suspensions exhibiting marked elastic properties. The effects of the GO particles lateral dimensions and the number of GO layers per particle on the flow and viscoelastic properties are investigated. Rheological parameters useful for quantitative interpretation of the results were obtained by fitting the experimental data using Cross, Herschel-Bulkley, and generalized Maxwell models. All GO suspensions showed a marked shear thinning and thixotropic behaviour with a significant yield stress. Their mechanical spectra confirmed viscoelastic behaviour typical for a suspension in an arrested state. Observed differences in values of rheological parameters and their variations with concentration are explained by particle properties and corresponding rotational restrictions, electrostatic attraction/repulsion, nematic phase formation, and particle agglomeration. The research presents fundamental insights into the rheological properties of GO suspensions, which can be manipulated by varying particle geometry and concentration.

Performance Improvement of Asphalt Mastics Using Bamboo Fiber Reinforcement

Integrating fibers into asphalt mixtures improves their crack resistance and permanent deformation. Previous studies have found the effect of various fibers on asphalt mixtures, but bamboo fibers were not included. In addition to providing strength and toughness, bamboo fiber’s recycled nature saves resources and protects the environment. This study investigates the reinforcement effect by different particle sizes and contents of bamboo fiber on asphalt mastic. Three sizes (100 mesh, 200 mesh, and 400 mesh) and three contents (3%, 6%, and 9%) of bamboo fibers were selected to modify the asphalt mastic. The frequency sweep (FS), linear amplitude sweep (LAS), multiple stress creep recovery (MSCR), and bending beam rheometer (BBR) test were used to evaluate the linear viscoelastic properties, fatigue performance, rutting resistance, and cracking resistance of fiber-modified asphalt mastics, respectively. Results demonstrate that bamboo fibers have excellent stiffness-reinforced characteristics, increase the elasticity of the asphalt, and enhance the high-temperature stability and low-temperature crack resistance of the asphalt mastic but adversely affect the fatigue properties of the asphalt mastic. In addition, asphalt mastics exhibited the same crack initiation stage and different crack expansion behavior, and the fiber incorporation prevented further crack propagation. Burgers model was used to represent the rheological behaviors of the asphalt mastic with bamboo fiber, and the model parameters are estimated. Furthermore, the Burgers model results indicated that the fiber addition reduced the proportion of elastic compliance and viscous compliance but increased the proportion of delayed elastic compliance of the asphalt mastic. Finally, the statistical model obtained based on the statistical approach can appropriately fit the values of rheological parameters with different fiber contents and lengths. The optimal design solution is 200 mesh with 9% content.

Novel thermo-associating polymer/silica nanocomposite as a temperature-resistant rheology modifier for bentonite-free water-based drilling fluids

Thermo-associating polymers have emerged as the promising agent to regulate the rheological properties of bentonite-free drilling fluids (BFDF). However, the application of thermo-associating polymers in high temperature drilling was still limited due to its unsatisfactory thermal stability. In this study, the method of combine the advantages of thermo-associating polymers and nanoparticles into an organic/inorganic hybrid system has been used to further enhance the thermal stability of thermo-associating polymers. In detail, the novel thermo-associating polymer/silica nanocomposite (AMS-CGBA) was prepared by in situ polymerization under optimal synthesis conditions. Different techniques (FT-IR, 1H-NMR, Elemental analysis and TGA) were used to characterize the structure and the thermal stability of AMS-CGBA. Rheological performance of the AMS-CGBA in BFDF was comprehensively studied and compared with that of thermo-associating polymer (CGBA). The TGA results showed that AMS-CGBA had excellent thermal stability probably due to incorporation of amino-grafted nano-silica (AMS) into thermo-associating polymer. Results from rheological tests revealed that AMS-CGBA exhibited much better performance than CGBA in improving the thermal stability of BFDF under high temperature and high salt (HTHS). Especially at the concentration of 1.5 wt% AMS-CGBA, the AMS-CGBA based BFDF showed nearly 16 times higher values of rheological parameters (AV, PV and YP) than that of CGBA-containing fluid after aging at 200 °C. And the dynamic light scattering tests revealed that the stability temperature of AMS-CGBA molecular was higher than 160 °C, while that of the CGBA was lower than 150 °C. Moreover, the AMS-CGBA-containing fluids exhibited a weakened thermo-thickening viscosity over a wide temperature range (80–180 °C), which was favorable for the “flat” rheology characteristic of BFDF. And the thermo-associative mechanism of AMS-CGBA was investigated through differential scanning calorimetry experiments to analyze the rheological stability of AMS-CGBA-containing fluids at high temperatures. The nanocomposite with the characteristic of both thermosensitive polymers and nanoparticles showed potential application in rheological regulation of bentonite-free drilling fluids at high temperatures.

Исследование качества протеинового батончика для спортивного питания с рыбными белковыми добавками

The quality of a new protein bar for sports nutrition, enriched with fish protein supplements, obtained by hydrolysis of fish scales, was investigated. The objects of the study were two types of protein supplements and the finished product. The paper explores the main indicators of the bar quality. The mass fraction of moisture, fat, and ash was determined according to GOST 5900-2014, GOST 31902-2012 and GOST 5901-2014, the amino acid composition was determined by ion-exchange chromatography, and the mineral composition was determined by atomic absorption spectrometry. The biological value of the additives’ protein and the finished product was determined by the calculation method, structural and mechanical characteristics – using a Brookfield CT3 texture analyzer, organoleptic indicators – on a 100-point scale, microbiological indicators – by standard methods. The peptide-protein and protein-mineral supplements contained 98.8% and 54.1% protein, respectively. The second supplement contained calcium and phosphorus, respectively, 22% and 12%. The amino acid composition of the bar showed the presence of all essential amino acids and glycine, proline, alanine, which are important for the athletes. The mass fraction of protein in the finished bar was 23.5%, which is adequate to 24% of its total energy value and corresponds to high-protein sports nutrition products according to GOST 34006-2016. It has been proven that a bar weighing 60 g is functional in terms of the content of calcium and phosphorus (satisfaction with the daily norm by 44% and 31.4%, respectively), vitamin E and dietary fiber (satisfaction by 22.4% and 58%). The organoleptic analysis revealed its positive perception in all respects and the absence of a fishy aftertaste; the total scoring of the product was 85.75 points. Rational values of rheological parameters were established: limiting shear stress 20–25 kPa, adhesion 200–220 mJ, penetration number 4.7–5.2 mm, elastic modulus 0.08–0.1. According to the results of microbiological studies, the shelf life of protein bars was 28 days.

Evaluation of rheology and printability of 3D printing nutritious food with complex formulations

Understanding rheological properties and printability of complex food formulations is crucial for 3D printing. While nutritious formulations have been reported in the literature, these are still scarce when compared to the non-nutritious ones. These so-labeled nutritious formulations are achieved with few ingredients, leading to less challenging printability issues. The nutritious formulations presented here are reported for the first time and include up to 9 ingredients, including by-products (orange peel) and sustainable proteins (insect flour). This work aimed to evaluate and to correlate the printability and the rheological properties of nutritious complex food formulations. The concentration of pregelatinized corn starch (4–10% (w/w)) and printing temperature (27–47 °C) were varied. Rheological characterization of the studied food inks (i.e., amplitude sweep, shear-viscosity test, shear-recovery test, time-dependent shear test, temperature ramps, temperature sweep in the oscillatory mode) was performed. Printability was evaluated via a digital image analysis of the geometric features of the printed structures. An increment in the concentration of pregelatinized starch (from 4% to 10%) raised the yield stress and the storage modulus from 87.5 to 883.2 Pa and from 1004.9 to 2620.9 Pa, respectively. However, high values of rheological parameters did not correspond to an improved printability. For instance, the printability evaluation showed that formulations with 6% and 8% of pregelatinized starch were more suitable for printing than the one with 10%. Finally, initial mathematical correlations between rheology and printability were obtained and could be of benefit to potentialize complex food printing systems. The results presented showed that both, rheology, and printability analyzes, must be performed when printing complex formulations towards the development of personalized food items. More research in this regard is needed to develop new methodologies for the evaluation of 3D printing materials.

The impact of the pulsed electric field on the structural, morphological, functional, textural, and rheological properties of red rice starch (Oryza sativa)

AbstractThe aim of the present study was to evaluate the impact of pulsed electric field (PEF) on the structural, morphological, functional, textural and rheological properties of red rice starch (Oryza sativa). The 5 mm thick starch pastes were subjected to PEF at 10 and 30 kV cm−1 with a pulse frequency of 600 Hz for 90 s. PEF was responsible for decreasing crystallinity, due to the damage caused during processing. The spectra showed different intensities in the bands close to 1000 cm−1, a characteristic region of starch. PEF30 showed greater stability and less retrogradation. The values for textural and rheological parameters were decreased, showing the effect of treatments on amylopectin chains. Therefore, based on the results, nonthermal modification of red rice starch by PEF at 30 kV cm−1 is the most suitable formulation to obtain a new material with optimized characteristics.Practical ApplicationsThe results of this study are beneficial for the industry, where its use to process rice starch‐based foods is targeted. Due to the practicality and efficiency when it comes to a nonthermal process, the modification of the structures and the improvement of the nature of food materials is the main objective. The advantage of PEF is that it can be applied to solid foods (in the form of a paste) and to liquids (food fluids), varying system parameters such as electrical intensity. When working with starch in paste form, the article shows that the highest intensity (30 kV cm−1) was the most indicated.

A Lubrication‐Based Solver for Shear‐Thinning Flow in Rough Fractures

AbstractThe depth‐averaged (2D) lubrication theory is often adopted to simulate Newtonian flow in rough fractures. This approach, which is computationally much less expensive than using 3D CFD solvers, allows addressing large ensembles of stochastic fracture realizations. For creeping flow, the degree of approximation introduced is limited as long as the apertures vary relatively smoothly. We propose the first generalization of this approach addressing the flow of fluids whose rheology, described by the Ellis model, is shear‐thinning (ST) above a crossover shear stress and Newtonian (of viscosity μ0) below. The resulting nonlinear Reynolds equation for pressures is solved for a vast range of realistic rheological parameter values using a novel and specifically designed finite volume‐based numerical model. The spatial discretization takes inspiration from the graph p‐Laplacian to yield a symmetric Newton Jacobian, allowing for a highly efficient inexact implementation of the preconditioned conjugate gradient‐based Newton‐Krylov method. This is combined with a parameter continuation strategy to increase code robustness and ensure global convergence for flow indices as low as 0.1 with an excellent efficiency. This original solver is used to investigate realistic synthetic rough fracture geometries, which exhibits both self‐affinity and a correlation length. The results show that the ST rheology mitigates the effects of aperture heterogeneities, increasing fracture transmissivity by several orders of magnitudes as compared to the Newtonian flow of viscosity μ0 if the imposed macroscopic gradient is sufficiently large, and even rendering the rough fracture up to 10 times more permeable than a smooth fracture of identical mean aperture.

Functional application of Maillard conjugate derived from a κ-carrageenan/milk protein isolate mixture as a stabilizer in ice cream

In a previous study, κ-carrageenan (κ-Car) was conjugated with milk protein isolate (MPI) via the Maillard reaction in a wet-heating system, and the Maillard conjugate derived from the κ-Car/MPI mixture effectively improved the stability of oil-in-water emulsions. In this study, the κ-Car/MPI conjugate was used in ice cream products to investigate its potential as a stabilizer. The ice cream mixes stabilized by the κ-Car/MPI conjugate showed lower rheological parameter (ηa,10, K, Gʹ, and G″) values than those of ice cream mixes stabilized by the κ-Car/MPI mixture, and the physical stability of the ice cream mixes was improved by the addition of the κ-Car/MPI conjugate. No significant differences in the overrun and hardness values were observed between the κ-Car/MPI conjugate and κ-Car/MPI mixture in frozen ice creams. However, the ice cream with the κ-Car/MPI conjugate showed greater resistance to melting due to its improved water-holding capacity. These results suggest that ice cream with high melting resistance can be produced with the addition of the κ-Car/MPI conjugate. Thus, the κ-Car/MPI conjugate could be used as a novel stabilizer in ice cream products.

Rheological Information of Pudding-Thick Liquids Prepared Using Commercial Food Thickeners Marketed in Korea for Dysphagic Patients According to the Manufacturers' Guidelines.

Food thickeners are commonly used to prepare thickened liquids for the management of dysphagia. The National Dysphagia Diet (NDD) thickness levels of thickened liquids prepared with commercial food thickeners are known to vary depending on the thickener type, recommended amount of thickener, thickener brand, and preparation instructions. Particularly, detailed preparation instructions must be provided by the manufacturers to achieve the correct thickness levels. However, the rheological information on product labels provided by manufacturers is typically not accurate. Here, various pudding-thick liquids were prepared by mixing commercial xanthan gum (XG)-based thickeners based on the manufacturers’ guidelines, and their rheological properties were characterized. Several thickened liquids prepared with four different XG-based thickeners (A-D) marketed in Korea did not meet the pudding-like criterion (> 1,750 mPa·s) based on the NDD guidelines. Significant differences in rheological parameter values (ηa,50, n, and G′) were also identified among the various thickened liquids. Only one thickener (thickener A) manufactured in Korea showed optimal results, which satisfied the pudding-thick viscosity range for various food liquids and also showed lower stickiness and enhanced bolus formation ability for easy and safe swallowing when compared to other thickeners (B, C, and D).

ЭФФЕКТИВНОСТЬ ДЕЙСТВИЯ ПЛАСТИФИКАТОРОВ В ЗАВИСИМОСТИ ОТ СПОСОБА ИХ ВВЕДЕНИЯ В СОСТАВ БЕТОНА

Abstract. The article dwells on existing methods of plasticizing additive introduction into Portland cement-based concrete mortars. A review was performed of available works studying the reasons of different effect of pasticizers depending on the method of their introduction into concrete. It was supposed that different results in effectiveness of such additives may be connected to not only adsorption processes taking place on the surface of Portland cement aluminate and sulfate phases, but also to their concentration capillary redistribution mechanism within concrete structure. This assumption was experimentally tested using dispersed building materials deprived of calcium sulfates and aluminates. Dry process clinker-based cement consumption may be positively reduced at presence of a plasticizing additive provided it was wetted before that with mixing water. Such a result confirmed authors’ assumption that not only plasticizing agent, but cement as well may be spared in case of combined additive introduction method while maintaining the values of rheological and strength parameters of obtained products. An additional reduction in cement consumption per unit mass of products leads to a decrease in the "clinker-concrete intensity" parameter. This opportunity will contribute to the reduction of the greenhouse effect by reducing CO2 emissions into the atmosphere when firing Portland cement clincer. We concluded that our proposed decisive role of plasticizing additive redistribution capillary mechanism in cement paste intergrain air space enables, on a par with its adsorption counterpart, a more substantiated prediction of applied plasticizer efficiency depending on their properties, as well as on condition and pjase composition of applied binders and aggregates. Efficiency of cone penetration methods was demonstrated in analysis and control of Portland cement condition and behavior.

Rheological properties of thickened barium liquids prepared with xanthan gum‐based thickener and barium powder used in the diagnosis of dysphagia: Effect of thickener concentration and serving temperature

In this study, thickened barium liquids (TBL) were prepared by mixing a xanthan gum (XG)-based thickener at different concentrations (1.0%–3.0%) with a barium powder. The rheological properties of TBL and thickened non-barium liquids (TNL) at different thickener concentrations were examined under steady and dynamic shear conditions. The values of flow and dynamic rheological parameters (K, σoc, G′, and G″) of TBL were considerably higher than those of TNL. The extents of the TBL thixotropy loops decreased with an increase in thickener concentration, showing that at higher concentrations, the degree of shearing-induced structure breakdown was lower than at lower concentrations. Compared with those of TNL, the rheological characteristics of TBL were more strongly dependent on thickener concentration, indicative of a strong molecular interaction between XG and barium at high thickener concentrations. These results could facilitate the development and preparation of videofluoroscopic contrast media with rheological properties suitable for the diagnosis of dysphagia. Practical applications Thickened liquids (TL) prepared with XG-based food thickeners are widely used for the effective management of patients with dysphagia (difficulty of swallowing). In terms of clinical practice, the rheological characteristics of thickened barium liquids (TBL) prepared with both XG-based thickener and barium powder are very important for the preparing the contrast media used for videofluoroscopic swallow study (VFSS) which the swallowing safety and efficiency with a bolus are assessed. Our results showed that compared with those of TL without barium, the rheological characteristics of TBL were more strongly dependent on thickener concentration, indicative of a strong molecular interaction between XG and barium at high thickener concentrations. These results presented in this study will be useful for the development and preparation of videofluoroscopic contrast media with rheological properties suitable for the diagnosis of dysphagia.

Effect of κ‐carrageenan/milk protein interaction on rheology and microstructure in dairy emulsion systems with different milk protein types and κ‐carrageenan concentrations

We investigated the effect of κ-carrageenan (κ-CG) addition and supplementation with Na-CN, WPI, and MPI on the rheological properties, microstructure, fat globule size distribution, and stability of low-fat cream (LFC) emulsions containing 19% milk fat. Rheological parameter (ηa,10, K, and G′) values of LFCs increased with κ-CG addition. At 0.1% κ-CG concentration, MPI-stabilized LFC had higher G′ value (64.8 Pa) than those of WPI-stabilized LFC (51.3 Pa) and Na-CN-stabilized LFC (34.8 Pa), indicating the strong interaction between MPI and κ-CG. Cryo-SEM images showed the protein layers on milk fat globule membrane in dairy emulsions and revealed that κ-CG led to depletion-flocculation of milk fat globules and promoted clustering of globules. The creaming index values of LFCs with 0.10% κ-CG were lower than those of LFCs with 0.05% κ-CG. Thus, high κ-CG concentrations can contribute to the physical stability in dairy emulsions stabilized by milk proteins. Practical applications Milk proteins are widely used as emulsifiers, and κ-carrageenan (κ-CG) is added to dairy emulsion products to improve their physical properties and stability. Therefore, in this study, the effect of κ-CG addition on physical properties and stability of low-fat creams (LFCs) supplemented with different milk protein types (Na-CN, WPI, and MPI) was investigated. The strong synergistic interaction between proteins and κ-CG was observed in MPI-stabilized LFCs when compared to Na-CN- and WPI-stabilized LFCs. We found that the presence of κ-CG in MPI-stabilized LFCs improved the stability of LFCs by inhibiting the phase separation due to the high viscosity of the continuous phase. These findings suggest that dairy cream-based food products with desirable physical properties can be realized through κ-CG addition to LFC emulsions with milk proteins such as ice cream mix, coffee creamer, and light cream.

Influence of Graphene Oxide on Rheological Parameters of Cement Slurries

In recent years, graphene-based nanomaterials have been increasingly and widely used in numerous industrial sectors. In the drilling industry, graphene oxide in cement slurry has significantly improved the mechanical parameters of cement composites and is a future-proof solution. However, prior to placing it in a borehole ring space, cement slurry must feature appropriate fluidity. Graphene oxide has a significant influence on rheological parameters. Therefore, it is necessary to study graphene oxide’s influence on the rheological parameters of cement slurries. Thus, this paper presents rheological models and the results of studies on rheological parameters. A basic cement slurry and a slurry with a latex addition were used. The latex admixture was applied at concentrations of 0.1%, 0.03%, and 0.06%. In total, studies were carried out for six slurries with graphene oxide and two basic slurries. The obtained results of studies on the slurries with graphene oxide were compared with the control slurry. It was found that the smallest graphene oxide concentration increased slurry value, some rheological parameter values, plastic viscosity, and the flow limit. Surprisingly, a concentration up to 0.03% was an acceptable value, since the increase in plastic viscosity was not excessively high, which allowed the use of cement slurry to seal the hole. Once this value was exceeded, the slurry caused problems at its injection to the borehole.