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Objective: Passive stiffness, a biomechanical parameter, has a potential influence on running economy, thus playing a pivotal role in performance. This study aimed to quantify passive stiffness of the Achilles tendon and gastrocnemius muscle using myotonometry throughout an incremental running protocol. Methods: Twenty-one male participants underwent a multistage incremental test (Bordeaux test) on a treadmill until exhaustion. Passive stiffness of the gastrocnemius muscle and Achilles tendon was measured using a MyotonPRO device. Measurements were taken before, during, and after the incremental test. Results: Our findings indicated that passive stiffness of the medial gastrocnemius decreased at rest between prerun and postrun assessments (−20.12 N·m−1, P =.012). Furthermore, during the test, stiffness increased at low intensity (at 50% of maximal aerobic speed: +104.8 N·m−1, P =.042), returning to baseline values as intensity increased. Conclusions: Throughout an incremental running protocol, both Achilles tendon and gastrocnemius muscle stiffness initially increased and then decreased with escalating percentages of maximal aerobic speed. A deeper understanding of stiffness in running can inform more effective recommendations for runners' strengthening and training. [ABSTRACT FROM AUTHOR]

Regarding the rheological properties of fluids, certain nanoparticles can markedly modify the rheological behavior of low surface tension solutions by interacting with surfactant molecules. In this work, a low surface tension fluid with cetyltrimethylammonium chloride was prepared, and the silica nanoparticles were uniformly dispersed into it by ultrasonic dispersion. By adjusting the size, shape, and concentration of nanoparticles, the fluid behavior can be changed from Newtonian to non-Newtonian with finely tuned viscosity and characterized by a shear-thinning rheological behavior. In addition, this work explored how variations in environmental temperature and solution pH affect the rheological responses of the low surface tension suspension system. The experimental findings revealed that increasing the temperature substantially decreases the system's viscosity and induces a shear-thickening behavior. It is particularly significant that, under extreme pH conditions (either strongly acidic or alkaline), the viscosity of the nanoparticle suspensions was markedly enhanced at a particle concentration of 10 000 ppm. This interesting result coincided with a notable reduction in the zeta potential and an increase in the average particle size, suggesting an intensified aggregation of particles within the suspension system. A mechanism detailing the interaction between silica nanoparticles and surfactant micelles was proposed. This work indicates that the incorporation of nanoparticles into surfactant solutions offers a powerful approach to modulating fluid rheology across various conditions. [ABSTRACT FROM AUTHOR]

Bond line thickness (BLT) is an essential parameter of thermal conductive composite gels as the thermal interface material (TIM). Extensive research has been performed on designing next-generation TIMs with high thermal conductivity; however, it remains elusive how to link laboratory measurements and the theoretically predicted BLT. Here, we propose a new model to estimate BLT based on a rheological property, in which the TIM is assumed to be a simple power law fluid. To avoid the unrealistic situation of the BLT tending to zero, we introduce a decaying exponential function to describe the influence from fillers during the lid attach process and rebuild the force balance equation. Compared with previously reported models, the theoretical prediction BLT based on the proposed model is in good agreement with the experimental data. Our model has a guiding significance in predicting the BLT, which may help to optimize the thermal performance of TIMs. [ABSTRACT FROM AUTHOR]

Traditionally, stress fluctuations in flowing and deformed materials are overlooked, with an obvious focus on average stresses in a continuum mechanical approximation. However, these fluctuations, often dismissed as "noise," hold the potential to provide direct insights into the material structure and its structure-stress coupling, uncovering detailed aspects of fluid transport and relaxation behaviors. Despite advancements in experimental techniques allowing for the visualization of these fluctuations, their significance remains largely untapped as modeling efforts continue to target Newtonian fluids within the confines of Gaussian noise assumptions. In the present work, a comparative analysis of stress fluctuations in two distinct microstructural models is carried out: the temporary network model and the hydrodynamic dumbbell model. Despite both models conforming to the upper convected Maxwell model at a macroscopic level, the temporary network model predicts non-Gaussian fluctuations. We find that stress fluctuations within the temporary network model exhibit more pronounced abruptness at the local scale, with only an enlargement of the control volume leading to a gradual Gaussian-like noise, diminishing the differences between the two models. These findings underscore the heightened sensitivity of fluctuating rheology to microstructural details and the microstructure–flow coupling, beyond what is captured by macroscopically averaged stresses. [ABSTRACT FROM AUTHOR]

The superadiabatic dynamical density functional theory (superadiabatic-DDFT) is a promising new method for the study of colloidal systems out-of-equilibrium. Within this approach, the viscous forces arising from interparticle interactions are accounted for in a natural way by explicitly treating the dynamics of the two-body correlations. For bulk systems subject to spatially homogeneous shear, we use the superadiabatic-DDFT framework to calculate the steady-state pair distribution function and the corresponding viscosity for low values of the shear-rate. We then consider a variant of the central approximation underlying this superadiabatic theory and obtain an inhomogeneous generalization of a rheological bulk theory due to Russel and Gast. This paper thus establishes for the first time a connection between DDFT approaches, formulated to treat inhomogeneous systems, and existing work addressing nonequilibrium microstructure and rheology in bulk colloidal suspensions. [ABSTRACT FROM AUTHOR]

This paper reports on the effects of shear rate and interface modeling parameters on the hydrodynamic slip length (LS) for water–graphite interfaces calculated using non-equilibrium molecular dynamics. Five distinct non-bonded solid–liquid interaction parameters were considered to assess their impact on LS. The interfacial force field derivations included sophisticated electronic structure calculation-informed and empirically determined parameters. All interface models exhibited a similar and bimodal LS response when varying the applied shear rate. LS in the low shear rate regime (LSR) is in good agreement with previous calculations obtained through equilibrium molecular dynamics. As the shear rate increases, LS sharply increases and asymptotes to a constant value in the high shear regime (HSR). It is noteworthy that LS in both the LSR and HSR can be characterized by the density depletion length, whereas solid–liquid adhesion metrics failed to do so. For all interface models, LHSR calculations were, on average, ∼28% greater than LLSR, and this slip jump was confirmed using the SPC/E and TIP4P/2005 water models. To address the LS transition from the LSR to the HSR, the viscosity of water and the interfacial friction coefficient were investigated. It was observed that in the LSR, the viscosity and friction coefficient decreased at a similar rate, while in the LSR-to-HSR transition, the friction coefficient decreased at a faster rate than the shear viscosity until they reached a new equilibrium, hence explaining the LS-bimodal behavior. This study provides valuable insights into the interplay between interface modeling parameters, shear rate, and rheological properties in understanding hydrodynamic slip behavior. [ABSTRACT FROM AUTHOR]

We numerically investigate the dynamics and linear rheology of disordered systems made of patchy particles, focusing on the role of valence, temperature, and bonding mechanism. We demonstrate that the dynamics is enslaved to bonding, giving rise to an activated behavior at low temperatures. By independently computing the diffusion constant and the viscosity from the simulations, we also confirm the validity of the Stokes–Einstein relation in valence-limited systems, with two caveats: (i) the diffusion constant requires a finite-size correction, at least at the intermediate density we investigate, and (ii) there is the onset of a breakdown that appears at the lowest temperatures considered. Finally, our results show that the storage and loss moduli of mixtures of divalent and M-valent particles exhibit an apparent power-law dependence on frequency, hinting at the possibility of using the composition to finely tune the rheological response of these materials. Our results compare well with literature experimental data on valence-limited DNA nanostars. In addition, the wealth of data we present and analyze here will help develop and test theoretical frameworks aimed at describing the dynamics of flexible limited-valence particles that self-assemble into disordered networks. [ABSTRACT FROM AUTHOR]

Large gas bubbles can reach the surface of pools of mud and lava where they burst, often through the formation and expansion of circular holes. Bursting bubbles release volatiles and generate spatter, and hence play a key role in volcanic degassing and volcanic edifice construction. Here, we study the ascent and rupture of bubbles using a combination of field observations at Pâclele Mici (Romania), laboratory experiments with mud from the Imperial Valley (California, USA), numerical simulations and theoretical models. Numerical simulations predict that bubbles ascend through the mud as elliptical caps that develop a dimple at the apex as they impinge on the free surface. We documented the rupture of bubbles in nature and under laboratory conditions using high-speed video. The bursting of mud bubbles starts with the nucleation of multiple holes, which form at a near-constant rate and in quick succession. The quasi-circular holes rapidly grow and coalesce, and the sheet evolves towards a filamentous structure that finally falls back into the mud pool, sometimes breaking up into droplets. The rate of expansion of holes in the sheet can be explained by a generalization of the Taylor-Culick theory, which is shown to hold independent of the fluid rheology.

Glutaronitrile (GN) doped with lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) at concentrations below and above the room-temperature conductivity optimum near 1M of Li salt is investigated using dielectric spectroscopy and shear rheology. The experiments are carried out from ambient down to the glass transition temperature Tg, which increases considerably as LiTFSI is admixed to GN. As the temperature is lowered, the conductivity optimum shifts to lower salt concentrations, while the power-law exponents connecting resistivity and molecular reorientation time remain smallest for the 1M composition. By contrast, the rheologically detected time constants, as well as those obtained using dielectric spectroscopy, increase monotonically with increasing Li salt concentration for all temperatures. It is demonstrated that the shear mechanical measurements are, nevertheless, sensitive to the 1M conductivity optimum, thus elucidating the interplay of the dinitrile matrix with the mobile species. The data for the Li doped GN and other nitrile solvents all follow about the same Walden line, in harmony with their highly conductive character. The composition dependent relation between the ionic and the reorientational dynamics is also elucidated. [ABSTRACT FROM AUTHOR]

Many microorganisms propel themselves through complex media by deforming their flagella. The beat is thought to emerge from interactions between forces of the surrounding fluid, the passive elastic response from deformations of the flagellum and active forces from internal molecular motors. The beat varies in response to changes in the fluid rheology, including elasticity, but there are limited data on how systematic changes in elasticity alter the beat. This work analyses a related problem with fixed-strength driving force: the emergence of beating of an elastic planar filament driven by a follower force at the tip of a viscoelastic fluid. This analysis examines how the onset of oscillations depends on the strength of the force and viscoelastic parameters. Compared to a Newtonian fluid, it takes more force to induce the instability in viscoelastic fluids, and the frequency of the oscillation is higher. The linear analysis predicts that the frequency increases with the fluid relaxation time. Using numerical simulations, the model predictions are compared with experimental data on frequency changes in the bi-flagellated alga Chlamydomonas reinhardtii. The model shows the same trends in response to changes in both fluid viscosity and Deborah number and thus provides a possible mechanistic understanding of the experimental observations.

The rapid development of additive manufacturing, also known as three-dimensional (3D) printing, is driving innovations in both industry and academia. Direct ink writing (DIW), an extrusion-based 3D printing technology, can build 3D structures through the deposition of custom-made inks and produce devices with complex architectures, excellent mechanical properties, and enhanced functionalities. A paste-like ink is the key to successful printing. However, as new ink compositions have emerged, the rheological requirements of inks have not been well connected to printability, or the ability of a printed object to maintain its shape and support the weight of subsequent layers. In this review, we provide an overview of the rheological properties of successful DIW inks and propose a classification system based on ink composition. Factors influencing the rheology of different types of ink are discussed, and we propose a framework for describing ink printability using measures of rheology and print resolution. Furthermore, evolving techniques, including computational studies, high-throughput rheological measurements, machine learning, and materiomics, are discussed to illustrate the future directions of feedstock development for DIW. The goals of this review are to assess our current understanding of the relationship between rheological properties and printability, to point out specific challenges and opportunities for development, to provide guidelines to those interested in multi-material DIW, and to pave the way for more efficient, intelligent approaches for DIW ink development. [ABSTRACT FROM AUTHOR]

The dynamics of wire frame particles in concentrated suspension are studied by means of a 2D model and compared to those of rod-like particles. The wire frames have bent or branched structures constructed from infinitely thin, rigid rods. In the model, a particle is surrounded by diffusing points that it cannot cross. We derive a formal expression for the mean squared displacement (MSD) and, by using a self-consistent approximation, we find markedly different dynamics for wire frames and rods. For wire frames, there exists a critical concentration of points above which they become frozen with the long time MSD reaching a plateau. Rods, on the other hand, always diffuse by reptation. We also study the rheology through the elastic stress, and more striking differences are found: the initial magnitude of the stress for wire frames is much larger than for rods, scaling such as the square of the point concentration, and above the critical concentration, the stress for wire frames appears to persist indefinitely while for rods it always decays. [ABSTRACT FROM AUTHOR]

The adaptive mechanical properties of soft and fibrous biological materials are relevant to their functionality. The emergence of the macroscopic response of these materials to external stress and intrinsic cell traction from local deformations of their structural components is not well understood. Here, we investigate the nonlinear elastic behavior of blood clots by combining microscopy, rheology, and an elastic network model that incorporates the stretching, bending, and buckling of constituent fibrin fibers. By inhibiting fibrin cross-linking in blood clots, we observe an anomalous softening regime in the macroscopic shear response as well as a reduction in platelet-induced clot contractility. Our model explains these observations from two independent macroscopic measurements in a unified manner, through a single mechanical parameter, the bending stiffness of individual fibers. Supported by experimental evidence, our mechanics-based model provides a framework for predicting and comprehending the nonlinear elastic behavior of blood clots and other active biopolymer networks in general.

In the present study, we focused on the development and characterization of formulations that function as biological inks. These inks were doped with coumarin derivatives to act as molecular luminescent sensors that allow the monitoring of the kinetics of in situ photopolymerization in 3D (DLP) printing and bioprinting using pneumatic extrusion techniques, making it possible to study the changes in the system in real time. The efficiency of the systems was tested on compositions containing monomers: poly(ethylene glycol) diacrylates and photoinitiators: 2,4,6-trimethylbenzoyldi-phenylphosphinate and lithium phenyl-2,4,6-trimethylbenzoylphosphinate. The selected formulations were spectroscopically characterized and examined for their photopolymerization kinetics and rheological properties. This is important because of the fact that spectroscopic characterization, examination of photopolymerization kinetics, and rheological properties provide valuable insights into the behaviour of photocurable resin dedicated for 3D printing processes. The next step involved printing tests on commercially available 3D printers. In turn, printing carried out as part of the work on commercially available 3D printers further verified the effectiveness of the formulations. Moreover the formulation components and the resulting 3D objects were tested for their antiproliferative effects on the selected Chinese hamster ovary cell line, CHO-K1. [Display omitted] • Bioinks doped with luminescent sensors for in situ photopolymerization monitoring. • Applications of bioinks at DLP and pneumatic extrusion 3D printing technique. • Cytotoxicity of the sensors in the tested range has not been indicated. • Intense Vis-LED radiation (405 nm) does not have a damaging effect on cells. [ABSTRACT FROM AUTHOR]

The SiO 2 -Al 2 O 3 refractories and corresponding inks for 3D printing were prepared from silica glass binder suspensions and fused alumina with grain sizes of 75 and 240 μm. Phase analysis (XRD) and morphological studies (SEM) were conducted to investigate the influence of sintering temperature and Al 2 O 3 content on the strength, porosity, and density of the refractories. Rheological studies (rotational viscometry) were carried out determine the effect of polyethylene glycol (PEG) and hydroxypropyl methylcellulose (HPMC) content on the flow behavior of the inks. It was established that firing refractories based on fused silica and fused alumina at 1500 and 1600 °C led to the formation of mullite and aluminosilicate melt on the surface of Al 2 O 3 grains, enhancing the strength of the synthesized materials. Addition of PEG and HPMC to the ink composition was found to improve their rheological properties by increasing yield strength and promoting plastic flow. The ink demonstrated high printability and they are suitable for producing refractories using the Direct Ink Writing method. [ABSTRACT FROM AUTHOR]

The use of graded-index (GRIN) lenses in infrared imaging systems is an effective way to reduce system volume. Chalcogenide glass has been considered an ideal matrix material to produce infrared GRIN lenes because of its excellent rheological property and large refractive index (RI) tunability. Herein, an axial GRIN Ge-As-Se-Te chalcogenide glass with large RI contrast (Δn) was designed and prepared. The GRIN glass was obtained by hot-pressing 11 stacked glass disks with gradually changing RIs and thermally treating them. The glass compositions of the disks were designed according to (1-x) (Ge 20 As 20 Se 20 Te 40)-xGe 12 As 22 Se 66 , where x = 0–1. It was found that these glasses had similar glass transition temperatures of 194∼199 °C, and excellent anti-crystallization performance. The RI (at 10 μm) of the glass dropped approximately linearly from 3.050 to 2.566 as x increased from 0 to 1. More than 1.2 mm diffusion depth was observed on hot-pressed two-layer glass preforms after only 24-h heat treatment. A GRIN glass with a thickness of ∼4.3 mm and linear RI profile was achieved by treating a hot-pressed eleven-layer glass preform for 24 h. The obtained GRIN glass showed good transmittance in the 3–12 μm wavelength range. These results indicate good prospects of the GRIN Ge-As-Se-Te glass for infrared imaging. [ABSTRACT FROM AUTHOR]

The current study focuses on the development and fabrication of ceramic nano inks with improved properties. Firstly, two types of pigments were prepared through a solid state process using fine gibbsite (Al(OH) 3) or aluminum chloride (AlCl 3) with cobalt chloride hexahydrate (CoCl 2.6H 2 O). The stoichiometric precursors were well-mixed and fired at 1000oC; then milled by a high energy ball mill to obtain nano pigments. The prepared pigments were investigated for their phase composition and crystallite size by X-ray diffraction, and further confirmed by Fourier Transform Infrared (FTIR). The morphology and particle size were examined using a scanning electron microscope. The optical properties in terms of UV–Vis, photoluminence emission spectra and CIE chromaticity diagram were also tested. The chemical-state of cobalt and surface elemental composition of prepared Co-aluminate pigments were tested by X-ray photoelectron spectroscopy (XPS). Four groups of ceramic-inks (twelve formulations) were prepared using different percentages of cobalt aluminate pigments and additives. The fabricated inks were investigated for their morphology, rheology, contact-angle and sedimentation behavior. The results revealed that two cobalt aluminate pigments with spinel structure, nano sized particles and blue color, were successfully prepared by the proposed method. The results of optical properties indicated that the cobalt ions are located mainly in tetrahedral sites with a small amount in octahedral sites. The prepared pigments were successfully used in the fabrication of ceramic nano inks with improved properties. The viscosity of most fabricated inks was in the range needed for the industry (4–40 mPa s). [ABSTRACT FROM AUTHOR]

Post-seismic deformation caused by large earthquakes is one of the most effective parameters for investigating the frictional behavior of faults and the rheological characteristics of the lithosphere. This study introduces a modified functional model that accounts for both afterslip and viscoelastic relaxation effects, incorporates a physical mechanism, and effectively disentangles distinct mechanisms of post-seismic deformation captured by continuous GNSS observations.A parameter optimization solution method based on the Bayesian framework was adopted to obtain optimal estimates and corresponding confidence intervals. The effectiveness of proposed model was validated through simulation experiments. The proposed method was applied to study post-seismic deformations from the 2015 Nepal M W 7.8 earthquake, and the different characteristics of post-seismic deformations caused by different mechanisms were discovered at different stations. The afterslip effect has the duration of 2.67 years, whereas the viscoelastic relaxation effect will continue for 150.8 years. Moreover, the calculated equivalent viscosity coefficient in the southern Tibet region was 1.1 ± 0.3 × 1018 Pa·s. Our proposed model can more accurately and objectively separate different mechanisms from the post-seismic displacements observed by GNSS than previous one, and thus improve the accuracy of fault kinematics and regional lithosphere rheology investigations. [ABSTRACT FROM AUTHOR]

The performance of incompatible blends is strongly depended on their morphology and interfacial properties that can be controlled by proper compatibilizers. This research systematically investigates the interfacial properties of the binary and the ternary blends based on low-density polyethylene (LDPE), poly(lactic acid) (PLA) and maleic anhydride-grafted polyethylene (PE-g-MAH) through the melt linear viscoelastic rheological behavior of the blends and neat components analyzed by proper rheological models. Moreover, the relationship between rheology, phase morphology and mechanical properties of LDPE/PLA ternary blends with different amounts of PE-g-MAH was studied. In the rheological analyses via the additive rule indicated in the molten state, no consistent interfacial interaction between LDPE and PLA phases is made due to the presence of PE-g-MAH at the interface of the blend. However, the analyses based on the Palierne's model implied that the interfacial tension of compatibilized blends decreases. This not only resulted in improving PLA dispersed phase morphology in the compatibilized blends, but also forming in situ fibrillar composites where the compatibilizer amount was relatively high (5 and 7.5 wt.%). Unlike the molten state, because of the strong interactions between PE and PLA phases of compatibilized blends in the solid state, the tensile mechanical properties, including Young's modulus, strength and elongation-at break, could be reinforced up to 24%, 25% and 90%, respectively. Overall, findings make a profound realization of the amount depended performance of PE-g-MAH as the most common compatibilizer for PE/PLA blends, very helpful not only from scientific viewpoints but also in terms of the blend industry applications. [ABSTRACT FROM AUTHOR]

This research investigates the rheological behavior of the Poloxamer–chitosan thermogel system for the release of doxorubicin, which is a chemotherapy agent. To design the experiment, the response surface method was used to optimize the formula and investigate the mutual effects of the variables on the rheological properties of the system. In this experimental design, Poloxamer as a thermogel matrix (15–20%) and chitosan biopolymer as an additive (0.1–0.3%) were used and the pH of the test environment was determined in the range of 2.0–7.5. The results showed that the rheological behavior of the Poloxamer–chitosan combination has the best fit according to the Herschel–Bulkley model with a correlation coefficient of 100%. Also, adding chitosan to Poloxamer decreased the gelation temperature and gelation time. The results showed that the concentration of Poloxamer and chitosan as well as system temperature have a significant effect on the rheological behavior of thermogel. The optimized formula showed favorable rheological properties including high viscosity and appropriate degradation rate. The study showed the sustained release of the drug in the in vitro environment of the thermogel system during 144 h. The kinetics of the drug's release were also studied based on zero-order, first-order, Higuchi, and Korsmeyer–Peppas models. It was found that the Higuchi (R2 = 0.9888) and Korsmeyer–Peppas (R2 = 0.9851) models are the best models for the prediction of release kinetics of doxorubicin. Therefore, the design of the Poloxamer–chitosan thermogel system has the potential to be used as an in situ drug delivery system for doxorubicin. [ABSTRACT FROM AUTHOR]

Direct ink writing (DIW) is one of the facile and versatile manufacturing techniques for additive manufacturing of ceramics. 3D printed porous boehmite structures fabricated via DIW can offer significant benefits in terms of their high specific surface area and robust mechanical properties, rendering them suitable for applications like catalysis, adsorption, etc. The characteristics of the boehmite structures produced through 3D printing are significantly influenced by several parameters associated with the DIW process, including but not limited to solids concentration in the ink, resolution, and drying time. In this work, for the first time, we try to optimize the DIW parameters for 3D printing of porous boehmite structures to achieve better shape stability, resolution, and mechanical properties. A shear-thinning boehmite ink was prepared by peptization of boehmite powder in nitric acid and the rheological properties were optimized by varying concentrations of boehmite and nitric acid. Boehmite ink with a solid loading of 37 % and a pH of 4 was found to have the optimal rheological properties and printability. A Menger sponge porous structure was printed by DIW using the optimized ink with different sample sizes and resolutions. The resolution and size were optimized for better shape accuracy of printing and structural integrity. Crack-free boehmite structures were obtained by optimizing the drying time. Boehmite structures printed with higher resolution resulted in enhanced compressive strength and energy absorption, i.e., compressive strength and energy absorption of 0.5 mm resolution boehmite structure is enhanced by 208 % and 144 %, respectively, compared to the 1 mm resolution structure. [ABSTRACT FROM AUTHOR]

Geopolymers represent a distinct class of materials characterised by their X-ray amorphous nature and nanoporous, nanoparticulate structure. Geopolymers can be conveniently mixed, poured, and cured under ambient conditions. This makes this class of materials an interesting alternative to ordinary Portland cement for structural processes. Additionally, the addition of alumina can improve mechanical properties, while the addition of glass can form an impermeable glaze which could be useful for molten salt containment. Therefore, in this investigation, potassium metakaolin-based geopolymer composites with varying proportions of glass particles and alumina platelets were fabricated, cured, heat-treated, and analyzed to study the effects of composition on material properties. Various attributes including rheological properties, densities, mass loss, shrinkage, and porosities were compared. It was observed that certain compositions exhibited high viscosities, making high shear mixing challenging, while also displaying significant permeability that would hinder their ability to contain liquids without leakage. Additionally, certain samples showed reduced densities, suggesting potentially weaker mechanical properties; however, the investigation did not include a direct assessment of mechanical properties. The most promising candidates for containing liquids at high temperature contained 50 wt% KGP, 25 or 35 wt% glass powder, and 25 or 15 wt% alumina platelets, respectively. ASH-G slurries required a minimum of 65 vol% KGP to produce a homogenous material compatible with additive manufacturing. The minimum amount of glass phase to form surface glazes was 16 vol%. Only samples containing more glass phase than alumina phase produced glazed composites. [ABSTRACT FROM AUTHOR]

Digital light processing technology has the advantages of high molding accuracy and the ability to prepare complex structures, which is commonly used in the preparation of resin or ceramics. By mixing two particle sizes of zirconia powders, this paper successfully prepared a 60 vol% slurry with a low viscosity of 1.28 Pa s at shear rate was 50 s−1. By systematically studying the rheological properties of the mixed slurry, the curing depth was exceeding 100 μm at exposure time of 3 s. Furthermore, by investigating the debinding process of the printed sample, it is found that the sintering sample after debinding in vacuum has the highest density. This work has a positive significance for the preparation and debinding process of high solid loading ceramic slurry. [ABSTRACT FROM AUTHOR]

[Display omitted] Aqueous solutions of long-chain water-soluble sucrose ester surfactants exhibit non-trivial response to temperature variations, revealing a peak in viscosity around 40–50 °C. While previous investigations have explored the structures within sucrose stearate systems at various constant temperatures, a comprehensive understanding of the entire temperature dependence and the underlying molecular factors, contributing to this phenomenon is currently missing. Temperature dependent properties and supramolecular structures formed in aqueous solutions of commercial sucrose palmitate were examined using SAXS/WAXS, DSC, optical microscopy, rheological measurements, NMR, and cryo-TEM. The underlying mechanism governing this unusual behavior is revealed and is shown to relate to the mono- to di-esters ratio in the solutions. Solutions primarily containing sucrose monoesters (monoesters molecules ≳ 98% of all surfactant molecules) exhibit behavior typical of nonionic surfactants, with minimal changes with temperature. In contrast, the coexistence of mono- and di-esters results in the formation of discrete monodisperse diester particles and a network of partially fused diester particles at low temperature. As the temperature approaches the diesters' melting point, wormlike mixed micelles form, causing a viscosity peak. The height of this peak increases significantly with the diester concentration. Further temperature increase leads to fluidization of surfactant tails and formation of branched micelles, while excess diester molecules phase separate into distinct droplets. [ABSTRACT FROM AUTHOR]

There is an increasing demand for fresh cheese varieties such as paneer because they offer ease of production, and time savings. Studies have been conducted on understanding the impact of milk composition on paneer quality, but there is no study on the effect of processing conditions on textural, rheological, and structural properties. To improve understanding of the impacts of processing on the quality attributes of paneer, six different samples were prepared in triplicate using two milk pre‐heat treatments (90°C/no hold or 90°C/10 min), and three coagulation temperatures (CT‐70, 80 or 90°C). Extensive interactions were observed between β‐lactoglobulin and κ‐casein at higher CT. An increase in G′ and G″ values of paneer was observed at 90°C CT. Formation of dense protein networks with less porous structure was observed at higher CT. These findings show that coagulation temperature is critical for control of the physicochemical properties, and quality of paneer. [ABSTRACT FROM AUTHOR]

We introduce a method for precise and accurate measurements of particle speeds in dense suspensions flowing at high rates and demonstrate the utility of the approach for revealing complex flow fluctuations during shearing in a setup that combines imaging with a confocal microscope and shearing with a rheometer. We scan the focal point in one dimension, aligned with direction of flow, producing absolute measurements of speed that are independent of suspension structure and particle shape. We compare this flow-direction line scanning approach with a complementary method we introduced previously, measuring speed using line scanning in the vorticity direction. By comparing results in various flow conditions, including shear-thinning and thickening regimes, we demonstrate the efficacy of our new approach. We find that both approaches exhibit qualitatively similar flow profiles, but a comparative analysis reveals a 15%–25% overestimation in speed measurement using vorticity line scanning, with discrepancies generated by anisotropic suspension microstructure under flow. Moreover, in the thickening regime where complex flow fields are present, both approaches capture local speed fluctuations. However, line scanning in the flow direction reveals and precisely captures stagnation and backflows, a capability not achievable with vorticity line scanning. The approach introduced here not only provides a refined technique for speed measurement in fast-flowing suspensions but also emphasizes the significance of accurate measurement techniques in advancing our understanding of flow behavior in dense suspensions, particularly in contexts where strong non-affine flows are prevalent. [ABSTRACT FROM AUTHOR]

Hydrogel foams are widely used in many applications such as biomaterials, cosmetics, foods, or agriculture. However, controlling precisely foam morphology (bubble size or shape, connectivity, wall and strut thicknesses, homogeneity) is required to optimize their properties. Therefore, a method is proposed here for generating, controlling, and characterizing the morphology of hydrogel foams from liquid foam templates: Using the example of Alginate‐CaHPO4‐based hydrogel foams, a highly controllable foaming process is provided by bubbling nitrogen through nozzles into the solution, which produces hydrogel foams with millimeter‐sized bubbles. A rheological characterization protocol of the foam's constituent material is first implemented and highlights the impact of the initial liquid foam properties and of the competition between the solidification kinetics and the foam aging mechanisms on the resulting morphology. X‐ray tomographic characterization performed on solidifying and solidified samples then demonstrates that by controlling the temporal evolution of the foam via its formulation, it is possible to tune the final morphology of the alginate foams. This method can be adapted to other hydrogel or polymer formulations, foam characteristics and length scales, as soon as solidification processes happen on timescales shorter than foam destabilization mechanisms. [ABSTRACT FROM AUTHOR]

In this work, Gum ghatti-cl-poly(acrylic acid)/CoFe2O4 (GGAACF) hydrogels were synthesized using a free radical polymerization technique, with CoFe2O4 nanoparticles incorporated via a co-precipitation method using nitrates as precursors. Thermal gravimetric analysis (TGA) revealed that the inclusion of CoFe2O4 nanoparticles enhanced the thermal stability of the hydrogels. Swelling studies indicated that the addition of 30 mg of CoFe2O4 nanoparticles maximized water retention. Rheological assessments demonstrated non-Newtonian behavior, with flow curves fitted best by the Power Law model. The incorporation of CoFe2O4 nanoparticles significantly improved the hydrogel's elasticity and viscosity, as evidenced by a higher storage modulus (G′) compared to the loss modulus (G″) across all frequencies, indicating the elastic nature of the hydrogels. The decrease in complex viscosity with increasing frequency confirmed the pseudoplastic properties of the hydrogels, attributed to the random alignment of CoFe2O4 nanoparticles within the matrix. Tan δ values were below unity at all tested frequencies, underscoring the hydrogels' strong elastic properties. These findings highlight the effectiveness of rheological analysis in characterizing the viscoelastic behavior of polymer hydrogels, which can be tailored for various applications. [ABSTRACT FROM AUTHOR]

This article deals with the impact of short glass fiber (GF) on the performance of 60/40 wt% of polyamide 6/polyamide 12 (PA6/PA12) blend. The short fiber-reinforced composites were fabricated by using melt compounding via twin screw extruder and injection molding. The morphological, water uptake, rheological, thermo-mechanical, and mechanical properties of the composites were discussed. The morphological observations show that the PA6/PA12 blend exhibited compatible morphology and also adhesion between the fiber and matrix was quite strong. The tensile strength/modulus and storage modulus of the blend were substantially improved with GF reinforcement as a result of these morphological findings. While the water uptake of neat PA6 decreased significantly after blending with PA12, the incorporation of GF further reduced the water uptake of the PA6/PA12 blend. The thermomechanical analysis showed the enhancement of the stiffness of the composites and also glass transition temperature increment. [ABSTRACT FROM AUTHOR]

The trimeric cetyl cationic surfactant (TGC) forms reversible photosensitive micelle systems with the photosensitive counterions trans-4-phenylazo benzoic acid (trans-ACA). The Carreau-Yasuda model was used for the flow curves before and after UV irradiation. The effects of trans-ACA concentration, TGC concentration, and different durations of UV (365 nm) and visible light (465 nm) irradiation on the rheological properties of TGC/trans-ACA were investigated. Prior to UV irradiation, the TGC/trans-ACA system was composed of wormlike micelles, which showed pronounced shear thinning behavior, good thixotropy and viscoelasticity. Macroscopically, it appears as a difficult to flow solution. After UV irradiation, trans-ACA is isomerized to cis-ACA, and the worm-like micelles are transformed to spherical or short rod-like micelles, resulting in a significant decrease in thixotropy and viscoelasticity, and thus a decrease in viscosity and an increase in fluidity. At lower TGC concentrations, UV irradiation can induce a reversal of the rheological properties of the TGC/trans-ACA system, which exhibits a complete solution state. Exposure to visible light restores the rheology of the system to that prior to UV irradiation. Under UV and visible light irradiation at different times, the system obeys to the rheo-kinetic equation. The UV–vis spectrum confirms that the changes in the rheological properties of the TGC/trans-ACA system are due to the reversible photoisomerization of trans-ACA. [ABSTRACT FROM AUTHOR]

A goal of this study was to investigate the influence of fluidised bed agglomeration process with guar gum (GG) binder (0–0.3%) on the physical and rheological properties of agglomerated milk protein isolate (MPI). Larger and more porous particles were formed by the agglomeration process, resulting in an improvement in powder flowability, wettability and solubility. The agglomerate with 0.1% GG binder exhibited higher viscoelastic properties than other agglomerates, with viscoelastic moduli values decreasing as the binder concentration increased (0.1–0.3%). The findings demonstrate that the agglomeration process with GG improved the powder characteristics of MPI and influenced its rheological properties. [ABSTRACT FROM AUTHOR]

Acid treatment can alter the functional properties of whey protein isolate (WPI), but the effect of different acids on properties of WPI‐stabilised Pickering emulsion gel (PE) is unknown. Compared with WPI‐PE, droplet size of the acid‐treated WPI‐PE decreased but its zeta potential, apparent viscosity, binding water capacity and curcumin encapsulation were enhanced. Due to the formation of the tightest gel structure of malic acid‐Pickering emulsion gel, it showed the highest viscoelastic modulus, bound water content and gel stability. This work would introduce a novel method for the development of PEs with good gelatinisation and curcumin delivery system for food processing. [ABSTRACT FROM AUTHOR]

This study addresses the processing limitations of camel milk for production of textured camel milk cheese by utilising the green carob extract (GCE) as a novel coagulant. The response surface methodology was employed to assess the impact of GCE on the cheese quality parameters. Maximal soft camel cheese yield (24.1%) was achieved using 12% (v/v) of GCE, coagulation at 53.6°C, and incubation time of 9 h 52 min. Compositional analysis revealed the richness of soft camel cheese in dry matter (33.8 ± 81.61%), carbohydrates (3.66 ± 0.45%), and calcium (632.83 ± 68.43 mg/100 g). The addition of GCE enhanced the cheese's flavour and texture. [ABSTRACT FROM AUTHOR]

In order to overcome the drawback of poor mechanical and rheological properties and potentially extend the poly(butylene adipate-co-butylene terephthalate) (PBAT) application market, in this work, we developed PBAT blend with excellent comprehensive performance through blending with biodegradable poly(L-lactide) (PLLA) and poly(D-lactide) (PDLA). Two-step melt blending and constant polylactide (PLA) content were devised to prepared PBAT blend. The effect of PDLA on the crystallization properties, rheological properties, miscibility, morphological structure, and mechanical properties of blend was investigated. According to torque-time curve and DSC results, PLA stereocomplex (SC-PLA) crystallites were formed in blend system. DMA results confirmed that the compatibility between PBAT and PLLA was not changed when PDLA was introduced. SEM results showed that the phase morphology of PBAT/20PLLA/0PDLA blend displayed typical sea-island structure and the particle size of dispersed phase decreased accompanying by agglomeration when PDLA was added. Rheological results showed that percolation SC-PLA network structure had formed and a much denser crystallite network could be formed with high PDLA content, which significantly enhanced rheological properties of blend. The mechanical results demonstrated that the addition of PDLA could significantly enhance mechanical properties. The blend with 6 wt% PDLA presented yield strength, elongation at break, and modulus about 13.3 MPa, 307%, and 221.2 MPa, respectively, the yield strength and modulus increased by 141.7% and 54.7% compared with the pure PBAT. [ABSTRACT FROM AUTHOR]

The occurrence of preset flaws can influence the mechanical, physical, and other related properties of rock samples. To study the failure characteristics and crack growth of rock samples containing spatial-rotation (SR) fissures subjected to freeze–thaw (FT) cycles and loading, laboratory tests of SR fissured red sandstone under various factors were conducted. The frost heave pressure, creep deformation, P-wave velocity and damage variable of SR fissured rocks were monitored and analysed. Failure processes and 3D fracture patterns of the specimen were studied in great detail using Digital Image Correlation (DIC) and Acoustic Emission (AE) technologies. Based on the experimental results, a damage constitutive model of the SR fissured rocks under the freeze–thaw and loading (FT-L) was explored. The results revealed that the frost heave pressure can be classified into five types: hibernation, growth, eruption-stabilization, fluctuation, and dissipation. In addition, with the increase of initial damage and temperature (absolute value), the corresponding wave and creep curves increase gradually. Under the coupling of FT cycle and load at each stage, the damage variable exhibited a U-shaped change trend, and gradually increases with the increase of load level. It is worth noting that, the fracture pattern of rock bridge can be classified into three fundamental types (progressive, undulating and opening fracture). A new nonlinear damage constitutive model containing the Nishihara model and a rheological element was established in which the coupling model can characterize the whole creep process of SR fissured red sandstone under the combined action of FT cycles and creep loading. Thus, the proposed model is a very good tool for the analysis of load coupling problems involved in the slope of cold area. Highlights: The compression tests of spatial-rotation fissured sandstone under the freeze–thaw and loading were carried out. The progressive damage process of sandstone with a spatial-rotation fissure was given. The 3D fracture patterns containing rock bridge extension and fissure penetration were revealed. A damage rheological model that considers the temperature and load was established. [ABSTRACT FROM AUTHOR]

In tunnel construction, grouting is frequently used to decrease the permeability and increase the rock mass strength. One of the most challenging steps in grouting is choosing the best grout type to achieve the highest penetration and sealing efficiency in the joints. The main purpose of this study is to investigate the sealing efficiency of different grout types in the joints of a high-risk section of the Kerman water conveyance tunnel (KWCT). For this purpose, the penetrations of three types of grouts including Ordinary Portland Cement (OPC), Ultra-Fine Cement (UFC), and silica sol were determined using analytical equations. Thereafter, the sealing efficiency of each type of grout in joints with different apertures was calculated. Also, the penetration radius of each type of grout was simulated and calculated using UDEC code. Based on the results of the analytical equations, by performing the grouting for 20 min using silica sol-based grout, the joints of the high-risk section of the KWCT with apertures of 0.5–2.5 mm and 2.5–10 mm can be sealed at 'Fair' and 'Excellent' levels, respectively. Furthermore, based on the results of numerical simulations, the UFC and silica sol-based grouts can seal the joints in 'Good' and 'Excellent' levels, respectively. [ABSTRACT FROM AUTHOR]

Many intracontinental basins form as broad depressions through prolonged, slow subsidence of the continental lithosphere. Such long-lived basins can record lithospheric processes over hundreds of millions of years, serving as important archives of lithospheric evolution. Since continental amalgamation in the Mesoproterozoic, the lithosphere beneath the intracontinental Canning Basin has been subject to several tectonic events, with extensive crustal reworking evidenced through different upper crust data sets. However, knowledge of the structure of the subcontinental lithospheric mantle is lacking. As a consequence, understanding the coupled evolution between surface and deep lithospheric processes, crucial to resolving basin formation, development and survival, remains problematic. Here, we combine geochemical, geophysical and petrophysical data within a thermodynamic modelling framework to determine the thermochemical properties, rheology, density and seismic structure of the lithospheric and sublithospheric mantle beneath the Canning Basin. The results indicate a thick, rigid lithosphere with a maximum thickness of 185 km and strength of ca. 1 × 1013 Pa m, and an anomalously Fe-enriched subcontinental lithospheric mantle with a Mg# of 88.6. This mantle structure is not consistent with pre-collisional fragments or a Precambrian collisional setting and may reflect magmatic refertilization during high-volume mafic magmatic events. Potential candidate events are the ∼1070 Ma Warakurna, ∼825 Ma Gairdner and ∼510 Ma Kalkarindji Large Igneous Provinces. The youngest of these is temporally and spatially correlated with and therefore interpreted to have influenced the Canning Basin formation. We propose that refertilization caused a negatively buoyant subcontinental lithospheric mantle and prolonged subsidence and preservation of the basin, while the strong lithosphere ensured lithospheric stability and longevity. [ABSTRACT FROM AUTHOR]

In this study, oleogels were produced with the emulsion template method utilizing seven phenolic aldehyde fragrances (PAFs) crosslinked with chitosan, and the physical and chemical characteristics of oleogels prepared by different crosslinking factors were comparatively investigated. XRD and ATR-FTIR results showed that chitosan was crosslinked with the PAFs to generate Schiff bases and that the Schiff base reaction was the main contributing factor to the construction of the oleogels. Macroscopic characterization showed that all the oleogels had good Oil binding capacity (> 90%) and high gel hardness (> 55.46 g). The rheological properties showed that all the oleogels had high thermal stability and gel strength (G'>G"), as well as good thixotropic recovery (among them, CS-ISA had the largest thixotropic recovery of 24.05%), which indicated the elasticity and structural stability of the gel network formed by crosslinking of PAF and chitosan.Additionally, lower oxidation rates were observed for the peroxide value (POV) and thiobarbituric acid reactive substance (TBARS) values of all oleogels in accelerated oxidation experiments, all indicating good oxidative stability. [ABSTRACT FROM AUTHOR]

This study examined the effects of pulsed electric field (PEF) treatment on enzymes, non-starch polysaccharides, and bread-making potential of oat and barley flour. Enzyme activity, microstructure, β-glucan extractability, molecular weight (Mw) and structure of non-starch polysaccharides, dough rheology, and flat bread properties were determined. An exponential decay model explained better the residual activity of oat β-glucanase across electric field intensity than barley β-glucanase. PEF treatment of flour at 12 kV/cm for 162 ms significantly reduced β-glucanase activity (40.2–76.5%) while increasing the concentration of total β-glucans (33.5%) and water-extractable arabinoxylans (36–41%). Mw of linear β-d-glucans decreased (9%) while Mw of branched arabinoxylans increased (6–33%). Scanning electron microscopy showed changes in microstructure of barley proteins. Blending wheat flour (70%) with oat or barley flour (30% weight) after PEF treatment enhanced gluten aggregation energy (29–19%) and breakdown viscosity (18–43%) of dough, as well as increased β-glucan content (21–32%) but reduced specific volume (11–24%). The findings of this study provide a comprehensive insight into the PEF's potential for retarding enzymatic reactions and preserving integrity of cereal non-starch polysaccharides. [ABSTRACT FROM AUTHOR]

The increased demand for gluten-free (GF) foods calls for the incorporation of novel ingredients to improve the technological drawbacks of GF formulations. This study aimed to evaluate the potential of a Gelidium amansii polysaccharide–based (GAP) flour as a structure-supporting ingredient in gluten-free foods in terms of its impacts on the functional, rheological, and thermomechanical properties of composite gluten-free (CGF) flours and doughs at three addition levels. The addition of GAP improved the functional properties of CGF flours and promoted starch pasting while retarding starch retrogradation during the pasting process. The steady shear and frequency sweeping tests demonstrated that GAP addition resulted in a dose-dependent increase in the apparent viscosity, G′, and G″ moduli of the dough accompanied by a slight decrease in tan (δ). Through measuring changes in the thermomechanical properties of GAP-added dough using Mixolab®, it was further confirmed that the presence of GAP increased the dough stabilization time with reductions in the consistency loss and retardation of starch re-association in the cooling phase. This study extended the application of seaweed polysaccharides to improve quality attributes of GF formulation and shed light on the use of cost-effective ingredients from algae as alternative hydrocolloids in starchy-based foods. [ABSTRACT FROM AUTHOR]

This study investigated the impact of sprouted oats (SO) on dough properties and biscuit features. Unsprouted oats (USO) and SO (for 48 h and 72 h) were studied in wheat dough at 10, 20, and 30%, and gluten aggregation, mixing, and extensional properties were evaluated. USO caused a weakening in gluten aggregation capacity, an increase in water uptake, development time and dough rigidity, and a decrease in extensibility. Dough enriched in SO showed mixing profiles similar to wheat, but using SO strongly affected dough extensional properties, indicating gluten weakening. Changes in rheological properties suggested the use of SO at 20% level in biscuit production. Using oats did not affect either biscuit size or volume, but decreased both the hardness and the toughness of the product, with 72 h-SO having the greatest impact, especially on hardness. Further study will address consumer acceptability and nutritional features of the developed baked product. [ABSTRACT FROM AUTHOR]

Summary: This study examined the rheological and textural properties of gels produced through emulsion gelation using pea protein isolate (PPI). Emulsions were prepared with varying PPI concentrations (2%–10%) and 0.25 oil fraction, followed by heat treatment. Higher PPI concentrations improved encapsulation efficiency (EE), but heat slightly reduced it, though EE remained above 90%. Droplet size decreased with higher PPI. The emulsion was then gelled with different kappa‐carrageenan (KC) concentrations (1%–2%) and pH levels (4–7). Gel hardness increased with KC content, while adhesiveness decreased. Springiness, cohesiveness and water‐holding capacity (WHC) rose with pH and KC, while meltability decreased. Rheological tests showed stronger gels with higher KC and lower pH. Storage time generally increased gel strength, except at pH 4. This work highlights the interplay between PPI, KC, pH and storage time in shaping the properties of pea protein‐based emulsions and gels. [ABSTRACT FROM AUTHOR]

Summary: The effect of fava bean protein isolate (FPI) at varied concentrations (1%–4%, w/w) on gelation of sardine surimi was evaluated. Breaking force, gel strength, textural profile, and water holding capacity were improved with the addition of FPI (P < 0.05). However, deformation and whiteness of gel samples decreased slightly when higher levels (3%–4%) of FPI were used (P < 0.05). The improved gel properties were supported by enhanced rheological properties (G′ and G″) of gels containing FPI. Microstructure also revealed the formation of gel network with higher connectivity in samples containing 3%–4% FPI. No major changes in the myofibrillar proteins in surimi gel were observed as determined by FTIR spectra and protein patterns. Higher scores for texture and overall likeness were obtained for surimi gel containing 3%–4% FPI. Therefore, FPI is a promising plant‐based ingredient that can effectively improve the gel properties of low‐grade sardine surimi without causing beany flavour. [ABSTRACT FROM AUTHOR]

Summary: Three‐dimensional (3D) printing technology digitally designs and manufactures objects through computer‐controlled processes. It requires raw materials with specific rheological properties for extrusion and shape retention. Dairy products hold promise for 3D printing due to their ability to form structures and their nutritional value. However, the quality of 3D printing with dairy products relies on the properties of the printing ink and printer parameters, presenting challenges for practical applications. This work provided a summary of the suitability of dairy‐based 3D printed products, discussing physicochemical modifications and additives to enhance their suitability and nutritional properties. The internal structure and composition of printing inks derived from dairy products are closely linked to their printing performance. Physicochemical modifications and additives effectively improve printability and the nutritional aspects of dairy inks. The 3D printing suitability of dairy inks can be enhanced through physical, chemical or enzymatic treatments. The gel properties of dairy products can be improved by mixing them with hydrophilic gels, introducing calcium, and incorporating lipids to enhance the 3D printing performance of dairy products. 3D printing technology enables the customisation of dairy products with personalised control of nutritional content, meeting the increasing consumer and market demand for healthier foods. In the future, 3D printed dairy products are expected to constitute convenient and quick nutritious food and enter home kitchens. [ABSTRACT FROM AUTHOR]