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Aim: The aim of the study was to work out the composition of cream with extract of sapropel from Prybych deposits, Volyn region, Ukraine, and to determine its organoleptic, physicochemical indices, structural and mechanical (rheological) parameters, colloidal and thermal stability, as well as to justify the choice of effective preservatives. Materials and Methods: The following materials were employed: Extract of sapropel from Prybych deposits; emulsion base, containing corn oil, emulsifier №1, cetylstearyl alcohol, and purified water. To carry out the research a set of methods (centrifugal, thermal, and potentiomentric), to analyze colloidal and thermal stability, and to determine pH values of the tested samples were used. Rheological properties of the samples were determined on the rotating viscometer. Results: There was determined the influence of the extract on physicochemical and rheological properties of the emulsion base; all the experimental samples remain thermally and colloidally stable and have satisfactory organoleptic properties; incorporation of SE into an emulsion base in a concentration of up to 20% retains structural and mechanical properties of the base. Conclusion: As the results of the carried out experimental investigations, the effect of the SE on physicochemical and rheological properties of its emulsion base. Microbiological research showed that the maximum reduction of the number of viable cells of microorganisms was observed applying as preservatives euxyl K 100 (0.1%) and nisin (0.01%).

Drilling issues such as shale hydration, high-temperature tolerance, torque and drag are often resolved by applying an appropriate drilling fluid formulation. Oil-based drilling fluid (OBDF) formulations are usually composed of emulsifiers, lime, brine, viscosifier, fluid loss controller and weighting agent. These additives sometimes outperform in extended exposure to high pressure high temperature (HPHT) conditions encountered in deep wells, resulting in weighting material segregation, high fluid loss, poor rheology and poor emulsion stability. In this study, two additives, oil wetter and rheology modifier were incorporated into the OBDF and their performance was investigated by conducting rheology, fluid loss, zeta potential and emulsion stability tests before and after hot rolling at 16 h and 32 h. Extending the hot rolling period beyond what is commonly used in this type of experiment is necessary to ensure the fluid’s stability. It was found that HPHT hot rolling affected the properties of drilling fluids by decreasing the rheology parameters and emulsion stability with the increase in the hot rolling time to 32 h. Also, the fluid loss additive’s performance degraded as rolling temperature and time increased. Adding oil wetter and rheology modifier additives resulted in a slight loss of rheological profile after 32 h and maintained flat rheology profile. The emulsion stability was slightly decreased and stayed close to the recommended value (400 V). The fluid loss was controlled by optimizing the concentration of fluid loss additive and oil wetter. The presence of oil wetter improved the carrying capacity of drilling fluids and prevented the barite sag problem. The zeta potential test confirmed that the oil wetter converted the surface of barite from water to oil and improved its dispersion in the oil.

This thesis aims to further understanding of protein fluid gels and their potential for use in reduced fat products. Previous research on fluid gels has shown their potential for fat replacement in semi-solid foods, and protein fluid gels have been used for the stabilization of foams. This thesis will investigate processing methods for and the influence of pH on the production of protein fluid gels, determining how this influences the fluid gel properties. Initially, protein fluid gels produced from egg white were compared with those produced from WPI as protein fluid gels have been produced previously from WPI. These were produced through heating under shear. Rheology and soft tribology were used to investigate the properties of these fluid gels. As proteins have different net charges at different pH levels relative to the isoelectric point (pI), the influence of pH on fluid gel properties was investigated. Fluid gels produced at the pI were shown to produce aggregated particles of less than 1 μm diameter. These systems produced at the pI demonstrated greater friction values in the mixed and boundary regimes of lubrication. Egg fluid gels offer a new functional ingredient for food products, in particular products such as mayonnaises and dressings in which egg is already an ingredient. Following on from this, dry protein fluid gel particles were produced from WPI through spray drying, and the properties of suspensions for these particles were investigated. To further understand the potential of these systems for use in reduced fat products, properties of emulsions stabilized by these particles were investigated and compared with a full fat mayonnaise and an emulsion stabilized by commercially available SimplesseTM. The greatest loss of solubility through processing of WPI was observed at pH 3.5. At pH 3.5, particles with an average size of 22.9 ± 2.0 m upon dispersion were produced. Addition of salts after particle production showed no effect on suspension rheology, demonstrating the potential for use in reduced fat dressings or mayonnaises in which salt is an ingredient. Both the particles and soluble protein were shown to be surface active. Emulsions stabilized by 20% spray-dried WPI in the aqueous phase were stable and showed similar rheology with increasing oil contents with oil droplets shown to contribute to the structuring of suspensions. Protein particles are shown to contribute to the structure of reduced fat emulsions.

The utilization of lignin, the most abundant aromatic biomass component, is at the forefront of sustainable engineering, energy, and environment research, where its abundance and low‐cost features enable widespread application. Constructing lignin into material parts with controlled and desired macro‐ and microstructures and properties via additive manufacturing has been recognized as a promising technology and paves the way to the practical application of lignin. Considering the rapid development and significant progress recently achieved in this field, a comprehensive and critical review and outlook on three‐dimensional (3D) printing of lignin is highly desirable. This article fulfils this demand with an overview on the structure of lignin and presents the state‐of‐the‐art of 3D printing of pristine lignin and lignin‐based composites, and highlights the key challenges. It is attempted to deliver better fundamental understanding of the impacts of morphology, microstructure, physical, chemical, and biological modifications, and composition/hybrids on the rheological behavior of lignin/polymer blends, as well as, on the mechanical, physical, and chemical performance of the 3D printed lignin‐based materials. The main points toward future developments involve hybrid manufacturing, in situ polymerization, and surface tension or energy driven molecular segregation are also elaborated and discussed to promote the high‐value utilization of lignin. This article provides a comprehensive view of 3D printing techniques for lignin, and presents the state‐of‐the‐art of 3D printing of pristine lignin and lignin‐based composites. Importantly, the relationship between the lignin structures and the rheological behavior of lignin/polymer blends or composites, as well as, the resulted printability in combination with the potential problems and challenges are summarized.

Rheology: Theory and Applications, Volume 1 is a compilation of papers contributed by experts in the field of rheology - the science of deformation and flow.The collection provides the general concepts and laws of rheology.

Understanding how microscopic rearrangements manifest in macroscopic flow responses is one of the central goals of nonlinear rheological studies. Using the sequence-of-physical-processes framework, we present a natural 3D structure–rheology space that temporally correlates the structural and nonlinear viscoelastic parameters. Exploiting the rheo-small-angle neutron scattering (rheo-SANS) techniques, we demonstrate the use of the framework with a model system of polymer-like micelles (PLMs), where we unveil a sequence of microscopic events that micelles experience under dynamic shearing across a range of frequencies. The least-aligned state of the PLMs is observed to migrate from the total strain extreme toward zero strain with increasing frequency. Our proposed 3D space is generic, and can be equally applied to other soft materials under any sort of deformation, such as startup shear or uniaxial extension. This work therefore provides a natural approach for researchers to study complex out-of-equilibrium structure–rheology relationships of soft materials.

Over the past 25 years, IRIS has become an integral resource in materials laboratories around the world, bringing together stimulating communities of rheology experimentalists and theoreticians, rheological experts, and experts from other fields, and even making rheology accessible to non-rheologists. The calculational tools of IRIS interface data from different experimental findings with predictions from rheology theories. Since its beginning, many theory groups used IRIS to share their original codes for rheology predictions. We demonstrate this in two examples, (1) the detailed analysis of small amplitude oscillatory shear data (SAOS) and predictions thereof and (2) a theory, newly implemented in IRIS, that elegantly unites dynamical quantities from small amplitude oscillatory shear (SAOS) with data from filament stretching rheometry and predictions of transient shear. IRIS supports this convergence with a standardizing data (Dealy et al., J Rheol 39:253-265, 1995 ), which makes data sharing easy and independent of instrument brand-specific and laboratory-specific coding.