Properties Of Medium Research Articles

Observation of Thouless pumping of light in quasiperiodic photonic crystals

Topological transport is determined by global properties of physical media where it occurs and is characterized by quantized amounts of adiabatically transported quantities. Discovered for periodic potential, it was also explored in disordered and discrete quasiperiodic systems. Here, we report on experimental observation of pumping of a light beam in a genuinely continuous incommensurate photorefractive quasicrystal emulated by its periodic approximants. We observe a universal character of the transport which is determined by the ratio between periods of the constitutive sublattices, by the sliding angle between them, and by Chern numbers of the excited bands (in the time-coordinate space) of the approximant, for which pumping is adiabatic. This reveals that the properties of quasiperiodic systems determining the topological transport are tightly related to those of their periodic approximants and can be observed and studied in a large variety of physical systems. Our results suggest that the links between quasiperiodic systems and their periodic approximants go beyond the pure mathematical relations: They manifest themselves in physical phenomena which can be explored experimentally.

Further Results on the Effects of the Grinding Environment on the Flotation of Copper Sulphides

Grinding conditions affect the flotation of copper sulphide minerals as changes in the properties of the grinding media and their interactions with the sulphide minerals, and between sulphide minerals themselves, affect the chemical environment in the flotation pulp. Galvanic interactions between steel grinding media and sulphide minerals, and between sulphide minerals, can lower the pulp potential, decrease the dissolved oxygen concentration in the mineral slurry, and lead to the dissolution of iron and copper from the media and the minerals. As a result, the formation of hydrophilic iron hydroxides and their adsorption on the copper sulphide minerals can be deleterious to copper flotation while pyrite (when present) can be activated to flotation by dissolved copper lowering the grade of the copper concentrate. Electrochemically less active grinding media (e.g., chrome alloy balls rather than mild steel media) can have beneficial effects on flotation performance due to the lower oxidation of the grinding media and consequently the lower production of oxidised iron species in the pulp. Copper activation of pyrite can be decreased by chemical additions to the pulp. In this paper, relevant experimental data published in the last 15 years are discussed.

Microstructural characterization of DEM-based random packings of monodisperse and polydisperse non-convex particles.

Understanding of hard particles in morphologies and sizes on microstructures of particle random packings is of significance to evaluate physical and mechanical properties of many discrete media, such as granular materials, colloids, porous ceramics, active cells, and concrete. The majority of previous lines of research mainly dedicated microstructure analysis of convex particles, such as spheres, ellipsoids, spherocylinders, cylinders, and convex-polyhedra, whereas little is known about non-convex particles that are more close to practical discrete objects in nature. In this study, the non-convex morphology of a three-dimensional particle is devised by using a mathematical-controllable parameterized method, which contains two construction modes, namely, the uniformly distributed contraction centers and the randomly distributed contraction centers. Accordingly, three shape parameters are conceived to regulate the particle geometrical morphology from a perfect sphere to arbitrary non-convexities. Random packing models of hard non-convex particles with mono-/poly-dispersity in sizes are then established using the discrete element modeling Diverse microstructural indicators are utilized to characterize configurations of non-convex particle random packings. The compactness of non-convex particles in packings is characterized by the random close packing fraction fd and the corresponding average coordination number Z. In addition, four statistical descriptors, encompassing the radial distribution function g(r), two-point probability function S2(i)(r), lineal-path function L(i)(r), and cumulative pore size distribution function F(δ), are exploited to demonstrate the high-order microstructure information of non-convex particle random packings. The results demonstrate that the particle shape and size distribution have significant effects on Z and fd; the construction mode of the randomly distributed contraction centers can yield higher fd than that of the uniformly distributed contraction centers, in which the upper limit of fd approaches to 0.632 for monodisperse sphere packings. Moreover, non-convex particles of sizes following the famous Fuller distribution of the power-law distribution of the exponent q = 2.5, have the highest fd (≈0.761) with respect to other q. In contrast, the particle shapes have an almost negligible effect on the four statistical descriptors, but they are remarkably sensitive to particle packing fraction fp and size distribution. The results can provide sound guidance for custom-design of granular media by tailoring specific microstructures of particles.

In silico formulation optimization and particle engineering of pharmaceutical products using a generative artificial intelligence structure synthesis method

Pharmaceutical drug dosage forms are critical for ensuring the effective and safe delivery of active pharmaceutical ingredients to patients. However, traditional formulation development often relies on extensive lab and animal experimentation, which can be time-consuming and costly. This manuscript presents a generative artificial intelligence method that creates digital versions of drug products from images of exemplar products. This approach employs an image generator guided by critical quality attributes, such as particle size and drug loading, to create realistic digital product variations that can be analyzed and optimized digitally. This paper shows how this method was validated through two case studies: one for the determination of the amount of material that will create a percolating network in an oral tablet product and another for the optimization of drug distribution in a long-acting HIV inhibitor implant. The results demonstrate that the generative AI method accurately predicts a percolation threshold of 4.2% weight of microcrystalline cellulose and generates implant formulations with controlled drug loading and particle size distributions. Comparisons with real samples reveal that the synthesized structures exhibit comparable particle size distributions and transport properties in release media.

Unlocking Single-Particle Multiparametric Sensing: Decoupling Temperature and Viscosity Readouts through Upconverting Polarized Spectroscopy.

Upconverting particles (UCPs), renowned for their capability to convert infrared to visible light, serve as invaluable imaging probes. Furthermore, their responsiveness to diverse external stimuli holds promise for leveraging UCPs as remote multiparametric sensors, capable of characterizing medium properties in a single assessment. However, the utility of UCPs in multiparametric sensing is impeded by crosstalk, wherein distinct external stimuli induce identical alterations in UCP luminescence, hindering accurate interpretation, and yielding erroneous outputs. Overcoming crosstalk requires alternative strategies in upconverting luminescence analysis. In this study, it is shown how a single spinning NaYF4:Er3+, Yb3+ upconverting particle enables simultaneous and independent readings of temperature and viscosity. This is achieved by decoupling thermal and rehological measurements-employing the luminescence of thermally-coupled energy levels of Er3+ ions for thermal sensing, while leveraging the polarization of luminescence from non-thermally coupled levels of Er3+ ions to determine viscosity. Through simple proof-of-concept experiments, the study validates the capability of a single spinning UCP to perform unbiased, simultaneous temperature, and viscosity sensing, thereby opening new avenues for advanced sensing in microenvironments.

Economic Viability of Coffee Plants Cultivated in Agroforestry Systems in Southwest Goiás

Brazil is the world's leading coffee producer. Increased productivity has been observed in recent harvests due to new management and automation technologies. Even with the expectation of a reduction in national production, the state of Goiás has shown an increasing share in coffee production. The municipality of Rio Verde, in Goiás, is among the eight largest coffee producers in the state and is where the Fazenda da Mata enterprise, the main object of this research, is located. The objective of the research is to evaluate the performance of the production of Arabica coffee grown in an agroforestry system through studies on economic feasibility comparing the implementation costs plus the estimated costs and revenues of AFS with the conventional cultivation system. Coffee growing in AFS is a production system that requires research that presents results on economic analysis, thus the aim was to research the economic feasibility of growing coffee in AFS as a sustainable alternative for agribusiness, whose information can contribute to the decision-making of rural managers when comparing a conventional cultivation enterprise to AFS cultivation. Furthermore, AFS can contribute to increased agricultural productivity with less impact on the environment, revealing several possibilities of subsystems that can be applied to large, medium and small rural properties, considering the financial advantages and also the motivating values ​​that direct the farmer towards this agricultural activity. The economic analysis showed that the conventional cultivation system is more advantageous financially, however AFS also presented excellent results. Therefore, it is important to highlight other relevant factors that can be considered when deciding which cultivation system to use in coffee production. Although AFS presented lower financial results than the conventional system, it is a cultivation system that can provide a second source of income for the producer, such as the use of tree species.

GA-NIFS: JWST/NIRSpec IFS view of the z ∼ 3.5 galaxy GS5001 and its close environment at the core of a large-scale overdensity

We present JWST Near-Infrared Spectrograph (NIRSpec) observations in integral field spectroscopic (IFS) mode of the galaxy GS5001 at redshift z = 3.47, the central member of a candidate protocluster in the GOODS-S field. The data cover a field of view (FoV) of 4″ × 4″ (∼30 × 30 kpc2) and were obtained as part of the Galaxy Assembly with NIRSpec IFS (GA-NIFS) GTO programme. The observations include both high (R ∼ 2700) and low (R ∼ 100) spectral resolution data, spanning the rest-frame wavelength ranges 3700–6780 Å and 1300–11850 Å, respectively. These observations enable the detection and mapping of the main optical emission lines from [O II]λλ3726, 29 to [S III]λ9531. We analysed the spatially resolved ionised gas kinematics and interstellar medium properties, including obscuration, gas metallicity, excitation, ionisation parameter, and electron density. In addition to the main galaxy (GS5001), the NIRSpec FoV covers a close companion in the south, with three sub-structures with velocities blueshifted by ∼ − 150 km s−1 with respect to GS5001, and another source in the north redshifted by ∼200 km s−1. Optical line ratio diagnostics indicate star formation ionisation and electron densities of ∼500 cm−3 across all sources in the FoV. The gas-phase metallicity in the main galaxy is 12+log(O/H) = 8.45 ± 0.04, and slightly lower in the companions (12+log(O/H) = 8.34 − 8.42), consistent with the mass-metallicity relation at z ∼ 3. We find peculiar line ratios (high log[N II]/Hα = [−0.45, −0.3], low log[O III]/Hβ = [0.06, 0.10]) in the northern part of GS5001. These could be attributed to either higher metallicity, or to shocks resulting from the interaction of the main galaxy with the northern source. We identify a spatially resolved outflow in the main galaxy, traced by a broad symmetric component in Hα and [O III], with an extension of about 3 kpc. We find maximum outflow velocities of ∼400 km s−1, an outflow mass of (1.7 ± 0.4)×108 M⊙, a mass outflow rate of 23 ± 5 M⊙ yr−1, and a mass loading factor of 0.23. These properties are compatible with star formation being the driver of the outflow. Our analysis of these JWST NIRSpec IFS data therefore provides valuable, unprecedented insights into the interplay between star formation, galactic outflows, and interactions in the core of a z ∼ 3.5 candidate protocluster.

VOF-based modeling study of surface oscillation behavior and gas–liquid stirring dynamics in the bottom-blown reactors

Gas bottom-blown reactors are widely employed in the chemical, metallurgical, and biochemical industries due to their superior mixing capabilities. This study numerically investigates the gas–liquid flow hydrodynamics and bubble dynamics in a bottom-blown system with a circular boundary using the volume of fluid approach. Following the experimental validation of the mathematical model, the study evaluates the effects of gas flow rates, liquid heights, and fluid medium properties on both the dynamics of the bubble swarm and the mixing characteristics of the flow field. The results indicate that: (1) Rising bubbles disturb the fluid, generating numerous vortices that facilitate momentum transfer for effective gas stirring; (2) The height of the liquid surface oscillation during the bottom-blown process exhibits significant temporal variation, with the peak showing clear lateral swings; (3) Due to the nonlinear interactions involving bubble coalescence and breakup during their ascent, along with constructive and destructive interference between liquid surface waves, the liquid surface can exhibit violent fluctuations at certain moments; (4) Bubble size and aspect ratio significantly influence liquid surface oscillations; (5) The bubble rising path displays instability due to vortex shedding, with some vortices forming at locations where the bubble shape changes abruptly. A bubble velocity prediction equation is proposed: uc=σ5.2737Lcρc4.2737/16156μl9.5475.

Physical and Chemical Properties of Media and Growth Characteristics of Three Species of Trees according to the Mixing Ratio of Quercus Bark

Physical and Chemical Properties of Media and Growth Characteristics of Three Species of Trees according to the Mixing Ratio of Quercus Bark

Performance Evaluation of Directional Porous Oil Storage Medium Fabricated by PTFE and Naphthalene

Porous oil storage media is the core of self-lubricating rolling functional components. The internal pore directivity of porous oil storage media is different，and it reduces the utilization rate of lubricating oil. In this paper, a new fabrication method of porous oil storage media with directional pores is carried out, and the properties of the porous media, such as hardness, density, porosity, oil storage rate and oil retention rate are evaluated. The experimental results show that the fabrication pressure has a linear positive effect relationship with the hardness of the porous media, and has no significant effect on the density, porosity, oil storage rate and oil retention rate. The mass fraction of pore former has a linear negative effect relationship with the hardness and density of the porous media, and a linear positive effect relationship with the porosity the greater the mass fraction of pore former, the greater the initial oil seepage rate of oil rejection. The internal pores of the porous media have a fibrous structure of the karst cave type, and the internal pores are interconnected and have good orientation. This study aims to provide a lubricating theoretical reference for the fabrication of porous oil storage media.

Processing and Properties of Polyhydroxyalkanoate/ZnO Nanocomposites: A Review of Their Potential as Sustainable Packaging Materials.

The escalating environmental concerns associated with conventional plastic packaging have accelerated the development of sustainable alternatives, making food packaging a focus area for innovation. Bioplastics, particularly polyhydroxyalkanoates (PHAs), have emerged as potential candidates due to their biobased origin, biodegradability, and biocompatibility. PHAs stand out for their good mechanical and medium gas permeability properties, making them promising materials for food packaging applications. In parallel, zinc oxide (ZnO) nanoparticles (NPs) have gained attention for their antimicrobial properties and ability to enhance the mechanical and barrier properties of (bio)polymers. This review aims to provide a comprehensive introduction to the research on PHA/ZnO nanocomposites. It starts with the importance and current challenges of food packaging, followed by a discussion on the opportunities of bioplastics and PHAs. Next, the synthesis, properties, and application areas of ZnO NPs are discussed to introduce their potential use in (bio)plastic food packaging. Early research on PHA/ZnO nanocomposites has focused on solvent-assisted production methods, whereas novel technologies can offer additional possibilities with regard to industrial upscaling, safer or cheaper processing, or more specific incorporation of ZnO NPs in the matrix or on the surface of PHA films or fibers. Here, the use of solvent casting, melt processing, electrospinning, centrifugal fiber spinning, miniemulsion encapsulation, and ultrasonic spray coating to produce PHA/ZnO nanocomposites is explained. Finally, an overview is given of the reported effects of ZnO NP incorporation on thermal, mechanical, gas barrier, UV barrier, and antimicrobial properties in ZnO nanocomposites based on poly(3-hydroxybutyrate), poly(3-hydroxybutyrate-co-3-hydroxyvalerate), and poly(3-hydroxybutyrate-co-3-hydroxyhexanoate). We conclude that the functionality of PHA materials can be improved by optimizing the ZnO incorporation process and the complex interplay between intrinsic ZnO NP properties, dispersion quality, matrix-filler interactions, and crystallinity. Further research regarding the antimicrobial efficiency and potential migration of ZnO NPs in food (simulants) and the End-of-Life will determine the market potential of PHA/ZnO nanocomposites as active packaging material.

Quantitative estimation of optical properties in bilayer media within the subdiffusive regime using tilted fiber-optic probe diffuse reflectance spectroscopy, part 2: probe design, realization, and experimental validation.

Tissues like skin have a layered structure where each layer's optical properties vary significantly. However, traditional diffuse reflectance spectroscopy assumes a homogeneous medium, often leading to estimations that reflects the properties of neither layer. There's a clear need for probes that can precisely measure the optical properties of layered tissues. This paper aims to design a diffuse reflectance probe capable of accurately estimating the optical properties of bilayer tissues in the subdiffusive regime. Using Monte Carlo simulations, we evaluated key geometric factors-fiber placement, tilt angle, diameter, and numerical aperture-on optical property estimation, following the methodology in Part I. A robust design is proposed that balances accurate intrinsic optical property (IOP) calculations with practical experimental constraints. The designed probe, featuring eight illumination and eight detection fibers with varying spacings and tilt angles. The estimation error of the IOP calculation for bilayer phantoms is less than 20% for top layers with thicknesses between 0.2 and 1.0mm. Building on the approach from Part I and using a precise calibration, the probe effectively quantified and distinguished the IOPs of bilayer samples, particularly those relevant to early skin pathology detection and characterization.

On the Physical Nature of Lyα Transmission Spikes in High-redshift Quasar Spectra

We investigate Lyman-alpha (Lyα) transmission spikes at 5.2 < z < 6.8 using synthetic quasar spectra from the “Cosmic Reionization on Computers” simulations. We focus on understanding the relationship between these spikes and the properties of the intergalactic medium (IGM). Disentangling the complex interplay between IGM physics and the influence of galaxies on the generation of these spikes presents a significant challenge. To address this, we employ Explainable Boosting machines, an interpretable machine learning algorithm, to quantify the relative impact of various IGM properties on the Lyα flux. Our findings reveal that gas density is the primary factor influencing absorption strength, followed by the intensity of background radiation and the temperature of the IGM. Ionizing radiation from local sources (i.e., galaxies) appears to have a minimal effect on Lyα flux. The simulations show that transmission spikes predominantly occur in regions of low gas density. Our results challenge recent observational studies suggesting the origin of these spikes in regions with enhanced radiation. We demonstrate that Lyα transmission spikes are largely a product of the large-scale structure, of which galaxies are biased tracers.

ISMGCC: Finding Gas Structures in Molecular Interstellar Medium Using Gaussian Decomposition and Graph Theory

Molecular line emissions are commonly used to trace the distribution and properties of molecular Interstellar Medium. However, the emissions are heavily blended on the Galactic disk toward the inner Galaxy because of the relatively large line widths and the velocity overlaps of spiral arms. Structure identification methods based on voxel connectivity in Position-Position-Velocity (PPV) data cubes often produce unrealistically large structures, which is the “over-linking” problem. Therefore, identifying molecular cloud structures in these directions is not trivial. We propose a new method based on Gaussian decomposition and graph theory to solve the over-linking problem, named InterStellar Medium Gaussian Component Clustering (ISMGCC). Using the Milky Way Imaging Scroll Painting (MWISP) 13CO(1–0) data in the range of 13.°5 ≤ l ≤ 14.°5, ∣b∣ ≤ 0.°5, and −100 ≤ V lsr ≤ +200 km s−1, our method identified three hundred molecular gas structures with at least 16 pixels. These structures contain 92% of the total flux in the raw data cube and show single-peaked line profiles on more than 93% of their pixels. The ISMGCC method could distinguish gas structures in crowded regions and retain most of the flux without global data clipping or assumptions on the structure geometry, meanwhile, allowing multiple Gaussian components for complicated line profiles.

Blood Based Magnetohydrodynamic Casson Hybrid Nanofluid Flow on Convectively Heated Bi-Directional Porous Stretching Sheet with Variable Porosity and Slip Constraints

Abstract Fluid flow through porous spaces with variable porosity has wide-range applications, notably in biomedical and thermal engineering, where it plays a vital role in comprehending blood flow dynamics within cardiovascular systems, heat transfer and thermal management systems improve efficiency using porous materials with variable porosity. Keeping these important applications in view, in current study blood based hybrid nanofluid flow has considered on a convectively heated sheet. The sheet exhibits the properties of a porous medium with variable porosity and extends in both the x and y directions. Blood has used as base fluid in which the nanoparticles of Cu and CuO have been mixed. Thermal radiation, space-dependent, and thermal-dependent heat sources have been incorporated into the energy equation, while magnetic effects have been integrated into the momentum equations. Dimensionless variables have employed to transform the modeled equations into dimensionless form and facilitating their solution using bvp4c approach. It has concluded in this study that, both the primary and secondary velocities augmented with upsurge in variable porous factor and declined with escalation in stretching ratio, Casson, magnetic and slip factors along x- and y-axes. Thermal distribution has grown up with upsurge in Casson factor, magnetic factor, thermal Biot number and thermal/space dependent heat sources while has retarded with growth in variable porous and stretching ratio factors. The findings of this investigation have been compared with the existing literature, revealing a strong agreement among present and established results that ensured the validation of the model and method used in this work.

Directional enhancement of underwater impact and bubble loads in neighbor two-phase fluid domains charge

The loading characteristics of underwater explosions and the dynamic behavior of bubbles are directly related to the charge structure. This study proposes a unique charge structure in a gas–liquid two-phase fluid domain. Numerical methods are used to investigate the effects of fluid layer thickness and gas–liquid ratio on underwater explosion shock wave load, bubble dynamics, and bubble pulsation load. The results show that the two-phase fluid layer significantly enhances the directional release of shock wave energy and bubble pulsation load. During the shock wave phase, a lagging wave effect appears in the liquid layer direction, causing a secondary high-energy shock, significantly increasing the specific impulse. The gas layer direction may form a pressure relief channel effect, enhancing the shock wave peak pressure. For the bubble motion phase, differences in the physical properties of the fluid layer medium lead to irregular bubble boundary movements, promoting bubble tearing and rupture. The gaseous medium converts the accumulated shock wave energy into the internal energy of the bubble, increasing its volume potential. Although this characteristic reduces the pulsation frequency, it significantly increases the specific impulse. Altering the fluid layer medium can control explosion loads and bubble movement, offering new insights for ocean engineering applications.

Wood-Based Biochar Ratio Used for Partial Peat Replacement in Growing Media for Antirrhinum majus Pot Production

Biochar has been promoted mostly as a soil supplement that improves plant growth/yield and to a lesser extent as a growing medium component. The alarmed situation for peat substitution in growing medium renders biochar as a promising substitute for current research. In this study, biochar derived by wood-based materials was evaluated at different ratios (0, 5, 10, 15, and 20% v/v) for peat partial substitution for Antirrhinum majus pot production. Biochar had increased potassium content and pH, which affected the growing media properties (total pores space and water filled capacity) and decreased nitrogen and phosphorus content in the media. Adding ≥15% biochar increased plant height and decreased flowering, but no effect was observed on plant biomass produced. The presence of biochar increased the total phenols and flavanols content and antioxidant capacity, with greater effects at the higher biochar rates used. This resulted in lipid peroxidation and an increase in hydrogen peroxide content, causing oxidative stress. Potassium and magnesium accumulated more but nitrogen and phosphorus were accumulated less in snapdragon leaves. Biochar at 10% can be considered as a successful candidate to partially substitute peat, and efforts to improve growing media characteristics are required for A. majus pot production.

Modeling and Analysis of Droplet Evaporation at the Interface of a Coupled Free-Flow–Porous Medium System

AbstractEvaporation of droplets formed at the interface of a coupled free-flow–porous medium system enormously affects the exchange of mass, momentum, and energy between the two domains. In this work, we develop a model to describe multiple droplets’ evaporation at the interface, in which new sets of coupling conditions including the evaporating droplets are developed to describe the interactions between the free flow and the porous medium. Employing pore-network modeling to describe the porous medium, we take the exchanges occurring on the droplet–pore and droplet–free-flow interfaces into account. In this model, we describe the droplet evaporation as a diffusion-driven process, where vapor from the droplet surface diffuses into the surrounding free flow due to the concentration gradient. To validate the model, we compare the simulation results for the evaporation of a single droplet in a channel with experimental data, demonstrating that our model accurately describes the evaporation process. Then, we examine the impact of free-flow and porous medium properties on droplet evaporation. The results show that, among other factors, velocity and relative humidity in the free-flow domain, as well as pore temperature in the porous medium, play key roles in the droplet evaporation process.

Effective elasto‐(visco)plastic coefficients of a bi‐phasic composite material with scale‐dependent size effects

We employ the theory of asymptotic homogenization (AH) to study the elasto‐plastic behavior of a composite medium comprising two solid phases, separated by a sharp interface and characterized by mechanical properties, such as elastic coefficients and “initial yield stresses” (i.e., a threshold stress above which remodeling is triggered), that may differ up to several orders of magnitude. We speak of “plastic” behavior because we have in mind a material behavior that, to a certain extent, resembles plasticity, although, for biological systems, it embraces a much wider class of inelastic phenomena. In particular, we are interested in studying the influence of gradient effects in the remodeling variable on the homogenized mechanical properties of the composite. The jump of the mechanical properties from one phase to the other makes the composite highly heterogeneous and calls for the determination of effective properties, that is, properties that are associated with a homogenized “version” of the original composite, and that are obtained through a suitable averaging procedure. The determination of the effective properties results convenient, in particular, when it comes to the multiscale description of inelastic processes, such as remodeling in soft or hard tissues, like bones. To accomplish this task with the aid of AH, we assume that the length scale over which the heterogeneities manifest themselves is several orders of magnitude smaller than the characteristic length scale of the composite as a whole. We identify both a fine‐scale problem and a coarse‐scale problem, each of which characterizes the elasto‐plastic dynamics of the composite at the corresponding scale, and we discuss how they are reciprocally coupled through a transfer of information from one scale to the other. In particular, we highlight how the coarse‐scale plastic distortions influence the fine‐scale problem. Moreover, in the limit of negligible hysteresis effects, we individuate two viscoplastic effective coefficients that encode the information of the two‐scale nature of the composite medium in the upscaled equations. Finally, to deal with a case study tractable semi‐analytically, we consider a multilayered composite material with an initial yield stress that is constant in each phase. Such investigation is meant to contribute to the constitution of a robust framework for devising the effective properties of hierarchical biological media.

Shearmetry of Fluids with Tunable Rheology by Polarized Luminescence of Rare Earth-Doped Nanorods.

Shear stress plays a critical role in regulating physiological processes within microcirculatory systems. While particle imaging velocimetry is a standard technique for quantifying shear flow, uncertainty near boundaries and low resolution remain severe restrictions. Additionally, shear stress determination is particularly challenging in biofluids due to their significant non-Newtonian behaviors. The present study develops a shearmetry technique in physiological settings using a biomimetic fluid containing rare earth-doped luminescent nanorods acting in two roles. First, they are used as colloidal additives adjusting rheological properties in physiological media. Their anisotropic morphology and interparticle interaction synergistically induce a non-Newtonian shear-thinning effect emulating real biofluids. Second, they can probe shear stress due to the shear-induced alignment. The polarized luminescence of the nanorods allows for quantifying their orientational order parameter and thus correlated shear stress. Using scanning confocal microscopy, we demonstrate the tomographic mapping of the shear stress distribution in microfluidics. High shear stress is evident near the constriction and the cellular periphery, in which non-Newtonian effects can have a significant impact. This emerging shearmetry technique is promising for implementation in physiological and rheological environments of biofluids.