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Magnetic ionic liquids (MILs) have proven effective as capture reagents for foodborne bacterial pathogens; however, there are currently no published studies regarding their use with foodborne, non-enveloped viruses. In this study, a protocol was evaluated for capture and recovery of bacteriophage MS2, a human norovirus surrogate, and purified viral genomic single stranded RNA (ssRNA) from an aqueous suspension using MILs. Transition metal-based MILs showed similar capture and recovery efficiency for both targets. A rare earth metal-based MIL showed much greater capture efficiency than the transition metal-based MILs, but displayed similar recovery. All tested MILs showed slightly higher capture and recovery efficiency for free RNA in comparison to intact virus, though overall trends were similar, and most MILs could recover both targets at as little as 102 PFU/mL intact MS2 or copies/mL purified RNA. A plaque assay confirmed that contact with MILs did not significantly reduce viral infectivity. Adjusting MIL volume gave no significant changes in capture or recovery, likely due to interplay between volume for the hydrophobic MIL and dispersion. Reducing the elution volume gave a slight increase in recovery, indicating MILs could be used for target enrichment after further optimization. MILs could also capture MS2 from romaine lettuce rinsate at comparable or even higher levels than from pure suspension, though loss in recovery was observed when the rinsate was prepared in an alkaline elution buffer. Overall, these results demonstrate the potential utility of MILs as concentration reagents for foodborne viruses, particularly for in-field applications. [ABSTRACT FROM AUTHOR]

Negatively charged drug molecules can be efficiently assembled and controlled on the positively charged micro‐nanoparticle (MNP) surfaces by utilizing the principle of electrostatic attraction. However, designing a system that the positively charged protein factors are efficiently assembled onto the positively charged carriers through leveraging homophilic interactions remains a formidable challenge. In solvents, the interplay between the electrostatic repulsion and the van der Waals attraction among the colloidal MNPs leads to the phenomenon of homophilic attraction described in the Derjaguin–Landau–Verwey–Overbeek (DLVO) theory. Is there a colloidal system that can be designed to enable the assembly of positively charged protein factors with the positively charged MNPs? Here, a novel photosensitive positive‐positive assembly of drugs is used as carrier, which is named as InGa3@polyvinylpyrrolidone (InGa3@PVP). Under the light excitation with the wavelength of 365 nm, this system exhibits homophilic attraction, enabling efficient assembly of the positively charged entities. This discovery offers a refined theoretical model for the drug delivery applications, facilitating the enhanced control and optimization of the positive‐positive assembly. [ABSTRACT FROM AUTHOR]

This study investigates the effect of particle concentration on tuneable magneto-optical transmittance and optically induced refractive index coefficients in Fe3O4-based nanomagnetic fluid (NMF) at room temperature. A static magneto-optical experimental setup was devised to investigate the magneto-optical effects arising from variations in particle concentration and dipolar interactions, under varying magnetic fields. In this work, Fe3O4-based nanomagnetic fluid was synthesized using a chemical co-precipitation method. The structural, morphological, and magnetic properties of the fluid were investigated using sophisticated characterization techniques including x-ray diffraction (XRD), high-resolution transmission electron microscopy (HRTEM), and vibrating-sample magnetometry (VSM). Our investigation focused on the tunability of magneto-optical transmittance as a function of the varying magnetic field at different particle concentrations. Further, we observed variations in diffraction fringes in the nanomagnetic fluid, correlating with particle concentration, by passing a high-power laser through the diluted fluid system. Light–matter interaction in the presence of a varying magnetic field induces optical anisotropy in the fluid, whereas dipole–moment interaction and magnetic particle alignment in the presence of a magnetic field are the main supporting phenomenon of magneto-optical tunability in our experiment. Experimental modulation of the transmittance profile and field-induced refractive index coefficients in NMF, elucidated through fringe diffraction, has potential for applications such as tuneable magneto-optical devices, optical filters, and optical limiters. [ABSTRACT FROM AUTHOR]

Magnetic supported ionic liquids are a unique subclass of ionic liquids that possess the ability to respond to external magnetic fields, combining the advantageous properties of traditional ILs with this magnetic responsiveness. A novel magnetic ionic nanocatalyst of Fe3O4@SiO2@CPTMS-DTPA was prepared by anchoring an ionic liquid, CPTMS-DTPA, onto the surface of silica-modified Fe3O4. The morphology, chemical structure and magnetic property of the magnetic ionic nanocatalyst structure was characterized using scanning electron microscopy, X-ray powder diffraction, Fourier transformation infrared spectroscopy, vibrating sample magnetometer, and thermogravimetric analysis. The results confirmed the successful attachment of the ionic liquid to the magnetic substrate. Subsequently, the magnetic nanocatalyst was employed for the green synthesis of α-aminophosphonate derivatives. The synthesis was achieved via a one-pot, three-component reaction involving various aldehydes, amines, and different trialkyl(aryl) phosphite derivatives. The reactions were conducted under ultrasound conditions for a duration of 10–25 min, resulting in good to excellent product yields (64–97%). Its recyclability was tested for up to five cycles using magnetic separation which makes it a highly efficient method for quickly separating catalysts from the reaction medium without compromising catalytic activity. [ABSTRACT FROM AUTHOR]

We consider the d-dimensional MagnetoHydroDynamics (MHD) system defined on a sufficiently smooth bounded domain, d = 2 , 3 with homogeneous boundary conditions, and subject to external sources assumed to cause instability. The initial conditions for both fluid and magnetic equations are taken of low regularity. We then seek to uniformly stabilize such MHD system in the vicinity of an unstable equilibrium pair, in the critical setting of correspondingly low regularity spaces, by means of explicitly constructed, static, feedback controls, which are localized on an arbitrarily small interior subdomain. In additional, they will be minimal in number. The resulting space of well-posedness and stabilization is a suitable product space B ~ q , p 2 - 2 / p (Ω) × B ~ q , p 2 - 2 / p (Ω) , 1 < p < 2 q 2 q - 1 , q > d , of tight Besov spaces for the fluid velocity component and the magnetic field component (each "close" to L 3 (Ω) for d = 3 ). Showing maximal L p -regularity up to T = ∞ for the feedback stabilized linear system is critical for the analysis of well-posedness and stabilization of the feedback nonlinear problem. [ABSTRACT FROM AUTHOR]

The pervasive presence of micro/nanoplastics in the environment is a significant threat to ecosystems and human health, demanding effective remediation strategies. Traditional methods for extracting these pollutants from water are often inadequate, typically leaving environmentally harmful residues. In response, this work introduces an innovative approach using reconfigurable and regenerable liquid metal microrobots (LiquidBots) that are magnetically driven to actively sequester micro/nanoplastics from aquatic environments. These LiquidBots utilize a coating of gallium oxide for enhanced adhesion and electrostatic interaction to capture over 80% of nanoplastics present in the solution. Additionally, the LiquidBots can be easily regenerated through sonication, which dislodges captured nanoplastics, allowing the microrobots to be reused. This novel technology offers a highly efficient, adaptable, and sustainable solution to combat the micro/nanoplastic pollution crisis. [ABSTRACT FROM AUTHOR]

In this research, we present a computational investigation into the behavior of turbulent ferromagnetic fluids flowing over a backward-facing step, influenced by an external magnetic field. Our model is subjected to a rigorous validation process to prevent error masking across various submodels. The study encompasses a range of Reynolds numbers ( Re H ) from 5000 to 80 000, expansion ratios ( E r ) from just above 1 to 2, Prandtl numbers (Pr) from 4 to 8, and Hartmann numbers (Ha) from 0 to 100. We introduce innovative correlations for the average Nusselt number, applicable in both the presence and absence of a magnetic field. These novel correlations are meticulously compared with existing empirical formulas, and their compatibility and discrepancies are critically analyzed. By incorporating a broader spectrum of physical phenomena, such as the braking effect of magnetohydrodynamics, the impact of the step geometry, the resulting recirculation zones, and the potential inaccuracies in calculating average velocity and Reynolds number, our new correlations substantially enhance the predictive accuracy of the average Nusselt number compared to previous models. [ABSTRACT FROM AUTHOR]

Ferrofluid droplet has wide applications in bioanalysis manipulation. This study presents a ferrofluid microrobot for manipulation in different workspaces. Based on the deformation character of droplet, the ferrofluid microrobot has the capabilities of climbing the 3D (3-dimensional) surface, splitting in the channel, and transporting large particles. To manipulate in multiple workspaces with the capabilities, the size and magnetic force of ferrofluid are studied for suitable scenes. It shows that the diameter of 0.5 μ l ferrofluid is around 980 μ m. The manipulation force of different ferrofluid microrobots ranges from micronewton to millinewton. Subsequently, we have verified the manipulation of the ferrofluid microrobot on a 3D chip by permanent magnet. The ferrofluid microrobot can climb the stairs only when the height of the magnetic fluid is higher than twice the height of the stairs. Meanwhile, splitting of ferrofluid microrobot in the microfluidic chip has been successfully demonstrated. It indicates that the splitting influenced by the magnetic field and large magnetic force is easier to split the microrobot. Finally, the transportation of large polystyrene microparticles (150 μ m) is confirmed by the ferrofluid microrobot. These capabilities show that the ferrofluid microrobot has the potential application advantage in biomedicine's micro-drug testing. [ABSTRACT FROM AUTHOR]

The integration of surfactants and nanoparticles in emulsion formulations has attracted significant attention due to their potential synergistic effects, improving stability and enabling the development of stimuli-responsive materials. The objective of this study was to investigate the stability, bulk rheological, and magnetorheological properties of oil in water (o/w) emulsions, composed of Fe3O4 kerosene-based ferrofluids dispersed in surfactant solutions (hexadecylpyridinium chloride, and nonylphenol polyethoxylate—ethylene oxide = 40, known as Tergitol NP-40), as a function of concentration and nature of the emulsifying agents. The results demonstrated the formation of stable systems (>2 months), featuring an average droplet size below 4 μm, with the primary stabilization mechanism attributed to the reduction of interfacial tension by surfactant activity. The emulsions exhibited shear thinning and viscoelastic solid-like behavior, which were enhanced by increasing the concentrations of both emulsifiers. Emulsions stabilized with hexadecylpyridinium exhibited a higher structural rigidity, with dynamic moduli an order of magnitude higher than Tergitol formulations. In the presence of a perpendicular magnetic field, it was demonstrated that incorporating ferrofluid as a dispersed phase in an o/w emulsion potentiates the magnetoviscous effect, compared to that observed with neat ferrofluid at the same concentration. A maximum relative increase in viscosity of up to 17-fold was observed in emulsions stabilized with 2.5 w/v% of hexadecylpyridinium and 10 000 ppm of nanoparticles when exposed to a linearly increasing magnetic field up to 796.73 mT at 1 s−1. The observed magnetoviscous effect remained reproducible for up to one year after formulation, highlighting the potential of these systems for multiple applications. [ABSTRACT FROM AUTHOR]

This review aims to contextualize the prospective integration of ferrofluid technologies into two critical oil macro-processes: recovery and transportation, both fundamental components of the oil supply chain. The initial section explores the research content and emerging trends associated with this technology by conducting a bibliometric analysis to highlight its advancements, drawbacks, and potential within the oil industry. The subsequent section discusses the most relevant theoretical aspects of ferrofluids, with a particular emphasis on stability, which is a pivotal yet insufficiently investigated aspect in the context of nanoparticle technologies in oil recovery and transportation. Furthermore, we present an overview of the magnetic properties, constitutive equations of ferrohydrodynamics, and magnetoviscous effects that elucidate the diverse rheological behaviors induced in ferrofluids by the action of uniform and oscillating magnetic field configurations. Against this background, subsequent sections summarize some selected experimental approaches conducted in systems that closely replicate real-world scenarios. These include the physiochemical interactions between ferrofluids and crude oils under the influence of external magnetic fields and thermodynamic flow conditions, such as those observed in reservoir environments. The review concludes with a section dedicated to the flow of ferrofluids in pipelines, highlighting experimental results under the influence of magnetic field configurations that induce reductions in viscosity, as well as alternative non-conventional applications associated with core annular flows. This comprehensive overview aims to provide an objective vision of the potential of ferrofluid technologies in enhancing the efficiency and effectiveness of multiple processes in the oil industry. [ABSTRACT FROM AUTHOR]

This study addresses the issue of unstable flow in large-scale annular linear induction pumps (ALIPs), with a focus on optimizing their design and enhancing performance. Utilizing the ALIP model developed by Toshiba Corporation as a reference, the design process employs the equivalent circuit method to improve the hydraulic performance of high-flow ALIP systems. A comparison of various hydraulic and excitation structure parameters facilitated the identification of an optimal design scheme. A numerical simulation of the ALIP's internal magneto-fluid coupling field was then conducted, based on magnetohydrodynamic (MHD) theory. The simulation results were validated against experimental data, confirming the model's accuracy. Further simulations under various operational conditions were performed to analyze the distribution and magnitude of the axial Lorentz force (FL) and the axial pressure gradient across different flow rates and currents. The analysis indicated that the unstable flow primarily results from inverse pressure gradients, which are caused by the uneven distribution of these forces. To mitigate this issue, the study proposes the addition of a regulating coil winding to the inner stator. This addition significantly reduces the uneven distribution of magnetic fields and pressure gradients. These coils generate a compensating magnetic field that enhances FL within the electromagnetic section, thereby improving the axial force on the magnetic fluid. The results demonstrate that this active regulation method markedly reduces unsteady flow phenomena, stabilizes fluid movement, and offers a novel design strategy for large-scale ALIP systems. The ratio of the area of the regulating coils to that of the driving coils is only 0.33, which minimally increases the pump dimension. Additionally, the energy conversion rate of different regulation currents between the inner and outer regulation coils was compared. It was found that variations in the regulation current alter the total efficiency of the ALIP by no more than 1%, indicating that the control coil winding consumes minimal energy and that the stability of the magnetic fluid can be effectively controlled, making this approach feasible for engineering applications. [ABSTRACT FROM AUTHOR]

In this paper, we focus on the properties of local energy minima and energy barriers in immobilized dense clusters of magnetic nanoparticles. Understanding of these features is highly interesting both for the fundamental physics of disordered systems with long-range interparticle interaction and for numerous applications of modern ferrofluids consisting of such clusters. In particular, it is needed to predict the ac-susceptibility of these systems and their magnetization relaxation after a sudden change in the external field, because both processes occur via magnetization jumps over energy barriers that separate the energy minima. Due to the exponential increase in the corresponding jump time with barrier height ( t sw ∼ exp (Δ E / k T) ), direct Langevin dynamics simulations of this process are not feasible. For this reason, we have developed efficient numerical methods both for finding as many energy minima as possible and for the reliable evaluation of energy barriers between them. Our results for the distribution of overlaps between the local energy minima imply that there is no spin-glass state in such clusters even when they consist of particles with a small anisotropy. Further, we show that the distributions of energy barrier heights are qualitatively different for clusters of particles with small, intermediate, and large anisotropies, which has important consequences for the magnetization dynamics of these systems. [ABSTRACT FROM AUTHOR]

In this paper, the semi-floating liquid bridge model with the silicone oil-based ferromagnetic fluid under microgravity was taken as the research object. The enhanced level set method was employed to numerically monitor the free surface flow characteristics, utilizing a staggered grid. The internal flow, temperature, velocity and interface deformation of thermocapillary convection under a uniform axial magnetic field were studied by direct numerical simulation. The results show that the transverse development of thermocapillary convection is suppressed by the axial uniform magnetic field, and the cell flow is controlled near the free surface. The average axial velocity was increased by about three times, and the average radial velocity was increased by about two times. The average axial temperature near the free surface was much higher than that on other radii. The axial temperature level of the surface flow was improved under of the influence of a uniform axial magnetic field. The axial temperature gradient in the central area of the liquid bridge basically showed the same change rule. The closer to the hot disk of the liquid bridge, the larger the axial temperature gradient. In addition, the axial uniform magnetic field effectively suppressed the micro-deformation of the free interface, and the free surface micro-deformation was at an order of magnitude of 10−5 (the deformation of the free surface in thermocapillary convection within a liquid bridge without a magnetic field was at an order of magnitude of 10−4). Therefore, studying the influence of the axial magnetic field on the thermocapillary convection of a high Prandtl number fluid can provide the necessary theoretical support for the development of crystal preparation technology. [ABSTRACT FROM AUTHOR]

The paper presents the results of computer simulating the structure formation in nanodisperse magnetic fluids and the influence of this process on the kinetics of their magnetization reversal. The work considers a system of identical spherical single-domain ferromagnetic particles suspended in a Newtonian fluid with magnetic moments "frozen" into the particle bodies. The particles are involved in intense Brownian motion. The magnetic interactions of all particles with each other, as well as of the particles with an external magnetic field, are considered. The results have shown that the evolution of the internal structures upon a change in the external field can greatly, by several orders of magnitude, change the characteristic time of ferrofluid magnetization reversal. The results obtained may be useful for the development of both the general theory of these systems and many methods for their high-tech applications. [ABSTRACT FROM AUTHOR]

The current investigation focuses on the magneto-nanofluid mixed convective boundary-layer flow of nanofluid caused by a vertical permeable plate with nonlinear thermal radiation. Furthermore, heat and mass transfer for water-base fluids influenced by heat generation/absorption and viscous dissipation have been analyzed. The convective boundary condition is also imposed on the vertical sheet. The main aim of the study is to investigate the five different types of nanoparticles, namely, silver $ ({\hbox{Ag}}) $ (Ag) , copper $ ({\hbox{Cu}}) $ (Cu) , alumina $ ({\hbox{A}{\hbox{l}_{\rm 2}}{\hbox{O}_{\rm 3}}})\hbox{,} $ (A l 2 O 3 ) , copper oxide $ ({\hbox{CuO}}) $ (CuO) , and titanium dioxide $ ({\hbox{Ti}{\hbox{O}_{\rm 2}}}) $ (Ti O 2 ) in the base fluid water. Moreover, the governing partial differential equations are converted into a set of ordinary differential equations via Sparrow–Quack–Boerner local nonsimilarity method. Additionally, nonlinear ODEs are successfully tackled by the Runge–Kutta–Fehlberg method. Physical parameters are examined graphically along with the velocity, temperature, and concentration distribution. Further, the skin friction coefficient, local Nusselt number, and Sherwood numbers are also studied in detail using graphs. The results show that increasing the value of buoyancy parameter and magnetic parameter fluid exhibits more resistance in the fluid, thereby fluid velocity and momentum boundary layer reduce. Moreover, the radiation parameter transmitted more heat from the surface to the fluid; as a result, the fluid temperature is boosted. [ABSTRACT FROM AUTHOR]

A novel and effective adsorbent based on magnetic polymeric ionic liquid nanocomposite-coated hollow fiber membrane (MPILNC-HFM) was developed and applied for magnetic solid phase extraction of Pb (II) and Cu (II) from environmental water and fruit juice samples with microinjection sampling-flame atomic absorption spectrometry (MIS-FAAS). During extraction process, the adsorbent coated on the surface of the hollow fiber can be removed from the solution using tweezers without using a magnet. Additionally, the need to use a centrifuge during adsorption and desorption steps is also eliminated, thereby increasing the speed, simplicity, and efficiency of the extraction process. The nanocomposite characterized through Fourier-transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), and energy-dispersive x-ray (EDX) analyses to ensure its applicability. The experimental parameters were optimized by applying one-variable-at the-time (OVAT) approach. Under optimal conditions, limits of detection were achieved 16.5 µg L−1 for Pb (II) and 20.4 µg L−1 for Cu (II), respectively, with relative standard deviations up to 7.9% and relative recoveries in the range of 91.8%–02.2%. [ABSTRACT FROM AUTHOR]

Artificial intelligence (AI) is employed in fluid flow models to enhance the simulation's accuracy, to more effectively optimize the fluid flow models, and to realize reliable fluid flow systems with improved performance. Jeffery fluid flow through the interstice of a cone-and-disk system is considered in this study. The mathematical description of this flow involves converting a partial differential system into a nonlinear ordinary differential system and solving it using a neurocomputational technique. The fluid streaming through the disk–cone gap is investigated under four contrasting frameworks, i.e., (i) passive cone and spinning disk, (ii) spinning cone and passive disk, (iii) cone and disk rotating in the same direction, and (iv) cone and disk rotating in opposite directions. Employing the recently developed technique of artificial neural networks (ANNs) can be effective for handling and optimizing fluid flow exploits. The proposed approach integrates training, testing and analysis, and authentication based on a locus dataset to address various aspects of fluid problems. The mean square error, regression plots, curve-fitting graphs, and error histograms are used to evaluate the performance of the least mean square neural network algorithm (LMS-NNA). The results show that these equations are consistently aligned, and agreement is, on average, in the order of 10−8. While the resting parameters were kept static, the transverse velocity distribution, in all four cases, exhibited an incremental decreasing behavior in the estimates of magnetic and Jeffery fluid factors. Furthermore, the results obtained were compared with those in the literature, and the close agreement confirms our results. To train the model, 80% of the data were used for LMS-NNA, with 10% used for testing and the remaining 10% for validation. The quantitative and qualitative outputs obtained from the neural network strategy and parameter variation were thoroughly examined and discussed. [ABSTRACT FROM AUTHOR]

Variational Monte Carlo (VMC) studies of extended Kitaev honeycomb models reveal a series of multinode quantum spin liquids (QSLs). They have an emergent Z2 gauge structure, a discrete number of symmetry-protected Majorana cones, and form Abelian or non-Abelian chiral spin liquids in applied magnetic fields. The large number of Z2 projective symmetry groups for spin–orbit-coupled states on the honeycomb lattice suggests that multinode QSLs can be found experimentally in future work on proximate Kitaev materials. [ABSTRACT FROM AUTHOR]

Materials that combine spin‐crossover (SCO) and liquid crystal (LC) behavior have gained significant attention due to their potential applications in technological devices, attributed to their easy processability. Herein, we report three neutral heteroleptic Fe(II) complexes: [Fe(dpa‐C4)2(NCS)2] (1), [Fe(dpa‐C6)2(NCS)2] (2), and [Fe(dpa‐C16)2(NCS)2] (3) (dpa‐Cn=N‐alkyl‐N‐(pyridin‐2‐yl)pyridin‐2‐amine; n=4, 6 and 16), which exhibit thermal‐induced spin transition behavior. The transition profiles and temperatures are effectively modulated by the length of the alkyl chains. Longer alkyl chains result in gradual and higher T1/2 values, while the shorter chains lead to abrupt SCO with lower T1/2 (i. e. T1/2=259 K (3) >237 K (2) >211 K (1)). Crystallographic studies reveal the impact of hydrophobic and hydrophilic packing in the crystal lattice, contributing to cooperativity and thereby affecting the SCO behavior. Complex 3 with long alkyl chain substitution, displayed non‐synchronized SCO‐LC behavior due to the thermal motion of the alkyl chains. [ABSTRACT FROM AUTHOR]

Liquid metal (LM)‐based magnetic fluids have attracted attention due to their rapid magnetic response, flexibility, and maneuverability. However, the nonwettability at the interface between metal particles and LM due to surface energy mismatch makes it challenging for metal particles to penetrate the LM oxide layer. Here, a strategy for mixing magnetic iron particles into LM through a reactive wetting mechanism is proposed. To address the inherent nonwettability at the interface between Fe particles and LM, FeGa2O4 is synthesized as a shell of Fe particles to enhance compatibility between Fe particles and LM. In particular, the wetting behavior of the FeGa2O4 shell on the interface between Fe@FeGa2O4 and LM is explained and validated based on the contact angle theory and density functional theory. Moreover, the mixture of Fe@FeGa2O4 particles into the LM enhances the rheological properties of the composite, effectively overcomes the inherent limitation of the low mechanical strength of LM, and improves the magnetic, electrical, and thermal properties of LM. Furthermore, studies on the adhesion mechanism of LM composites indicate that Fe@FeGa2O4 particles carrying more oxides into LM are crucial factors for adhesion. Given these notable advantages, LM‐based magnetic composites have shown tremendous potential in flexible electronics, soft robotics, and lightweight LM thermal interface materials. [ABSTRACT FROM AUTHOR]

In this paper we study the stability of a special magnetic Bénard system near equilibrium, where there exists Laplacian magnetic diffusion and temperature damping but the velocity equation involves no dissipation. Without any velocity dissipation, the fluid velocity is governed by the two-dimensional incompressible Euler equation, whose solution can grow rapidly in time. However, when the fluid is coupled with the magnetic field and temperature through the magnetic Bénard system, we show that the solution is stable. Our results mathematically illustrate that the magnetic field and temperature have the effect of enhancing dissipation and contribute to stabilize the fluid. [ABSTRACT FROM AUTHOR]

The scope of artificial intelligence in the field of fluid mechanics has been expanded with the development sophisticated technology to enhance the efficiency, reliability, solve complexities, introduced alternate transformation and enabling more dependable solutions with their analysis. The goal of this study is to investigate the ferromagnetic Powell‐Eyring fluids (FMPEFs) model with non‐Fourier heat flux by using artificial intelligence‐based scheme by exploiting the adaptive nonlinear autoregressive eXogenous (NARX) neuro‐architecture with backpropagation of Levenberg Marquart (LM), that is, NARX‐LM. The developed NARX‐LM methodology applied on synthetic datasets acquired with the help of Adams numerical method for FMPEF system by prudently changing physical quantities that is, material parameters of Eyring Powell, homogeneous reaction, heterogeneous reaction, dimensionless thermal relaxation time, Prandtl number, Schmidt number with fixed values parameter of ferrohydrodynamic interaction, rate of diffusion coefficient. Outcomes of NARX‐LM are regularly overlapping with the numerical results for the FMPEFs system having reasonable small error magnitude for each variant. The proficiency of intelligent computing anticipated on FMPEFs is depicted exhaustively with iterative mean squared error based iconvergence curves, analysis of adaptive controlling factors, error frequency distribution on the histograms, auto‐correlation, and correlation measures. [ABSTRACT FROM AUTHOR]

This article provides a quantitative analysis of the flow of MHD micropolar fluid through a Darcian permeable medium bounded by a stretched surface. The RK45 method, along with the shooting approach, is employed to perform the analysis. The impacts of Joule heating, thermophoretic, and Brownian diffusions over the fluid flow are particularly, focused in this research work. The study's findings can be applied in nanofluid technology for optimizing heat transfer, porous media engineering for designing efficient systems, and magnetohydrodynamics for applications like magnetic drug targeting and liquid metal cooling in nuclear reactors. The nonlinear partial differential equations (PDEs) that govern the flow are altered into nonlinear ordinary differential equations (ODEs) by using appropriate variable similarity transformations. Displayed the graphical effects of various physical factors over the velocity, angular velocity, concentration, and temperature profiles. Velocity profiles are enhancing as the micropolar fluid and porous factor rises whereas the opposite trend exists for the boosting estimations of the magnetic parameter. Temperature distribution is escalating for the rising estimations of the magnetic, Eckert, Brownian, and thermophoresis parameters but there is an opposite scenario deploys as the Prandtl number upsurges. As Schmidt and Brownian motion parameters increase, the micropolar nanoparticle concentration decelerates and elevates when the thermophoresis parameter is boosted. The micro-rotation profiles are enhanced as the values of the micropolar fluid parameter rise. The drag force was enhanced as the magnetic and micropolar fluid parameters upsurged but diminished when the porous parameter was elevated. The rate of heat flow diminishes with higher estimates of the micropolar fluid parameter but improves when the magnetic and Prandtl number parameters increase. The rate of mass flux escalates for the enhanced values of thermophoresis, Brownian, Schmidt, and chemical reaction parameters. Considerable numerical outcomes have been produced and cross-referenced with the latest study, which unveiled remarkable concurrence. [ABSTRACT FROM AUTHOR]

Time-dependent boundary conditions are very common in natural and industrial flows and by far no exception. An example of this is the movement of a magnetic fluid forced due to temporal modulations. In this study, we used numerical methods to examine the dynamics of ferrofluidic wavy vortex flows (WVF2, with dominant azimuthal wavenumber m = 2) in the counter-rotating Taylor–Couette system, which was subjected to time-periodic modulation/forcing in a spatially homogeneous magnetic field. In the absence of a magnetic field, all WVF2 states move in the opposite direction to the rotation of the inner cylinder, they are retrograde. However, when strength or frequency of the alternating magnetic field increases, the motion direction of the flow pattern changes. Thus, the alternating field provides a precise and controllable key parameter for triggering the system response and controlling the flow. Aside, we also observed intermittent behavior when one solution became unstable, leading to random transitions in both, the transition time and toward the different final solutions. Our findings suggest that, in ferrofluids, flow pattern reversal can be induced by varying a magnetic field in a controlled manner, which may have applications in the development of modern fluid devices in laboratory experiments. These findings provide a framework to study other types of magnetic flows driven by time-dependent forcing. [ABSTRACT FROM AUTHOR]

Abscesses, pockets of fluid caused by infections in the human body, are typically treated in hospitals by draining the fluid through a catheter. However, the viscous and heterogeneous nature of the fluid often leads to prolonged treatment duration or even drainage failure. Furthermore, current practice relies only on qualitative observations of viscosity for catheter size selection, with little quantitative data to guide this parameter. In this work, we introduce a compact magnetic stress rheometer platform to examine the rheological response of nine different abscess fluids under shear stress. A magnetic field applies a force to a probe that induces it to shear the underlying abscess fluid. Its spatiotemporal displacement is measured, resulting in the determination of creep compliance. The results are well-fitted to a 5-element viscoelastic model, providing a quantitative and robust prediction of abscess fluid rheology for a variety of etiologies. We show that while viscoelastic parameters between abscess fluids of different etiologies can span five orders of magnitude, zero-shear viscosity should be sufficient in future predictions of drainage flow rates. The custom-built instrument we have developed is portable, inexpensive, and sterile-compatible, serving as an ideal platform for point-of-care analyses in clinical settings to facilitate catheter selection and enable healthcare workers to devise optimal treatment strategies for each patient. Moreover, the versatility of our platform extends its potential application to rheological measurements in diverse medical contexts. [ABSTRACT FROM AUTHOR]

In the present paper, we mainly studied the Riemann problem and wave interaction of a simplified magnetohydrodynamic equation system. Due to the complex Riemann problem and wave interactions in the magnetohydrodynamic equations, most previous studies either did not investigate the interaction of elementary waves or, if they did, lacked supporting numerical experiments. This paper simplifies the magnetohydrodynamic equations using variable substitution. Using the characteristic line method to solve the Riemann problem and elementary wave interaction of the simplified magnetohydrodynamic equations, the form of the solution is more symmetrical and the interaction between waves has also become more regular. The correctness of the results was verified by numerical experiments. [ABSTRACT FROM AUTHOR]

A novel approach to enhancing the efficacy and surface quality of magnetic polishing involves the incorporation of a magnetic liquid circulation system for abrasive particle regeneration in conjunction with a circular Halbach array. The continuous renewal of abrasive particles within the polishing zone is realised through a conveyor belt that transports new abrasive particles into the polishing liquid solution. This formation of a continuously circulating polishing system ensures uninterrupted magnetic finishing processes and maintains stability throughout the polishing operation. This study extensively explores polishing force distribution, magnetic field distribution and abrasive grain behaviour in the polishing area facilitated by the magnetic liquid solution. The application of the proposed polishing processes to polymethyl methacrylate, an optical lens material, aims to comprehend the characteristics and validate the feasibility of the polishing method. Key influencing factors in the magnetic polishing process, including abrasive grain size, magnetic particle, polishing distance and conveyor speed to surface quantity, are examined through experimental analysis. Results of the experimental polishing processes demonstrate that the utilisation of circular Halbach arrays with circulating abrasives produces a nanometric surface finish. Even in the polishing of polymethyl methacrylate with an initial rough surface (Ra = 464.895 nm), the process achieves an ultra-fine level with Ra below 9 nmwithout disruption in the material polishing processes of optical lenses. [ABSTRACT FROM AUTHOR]

Optical field enhancement maximization has been the ultimate objective of applications covering random lasers, spectroscopy, and ‐importantly‐ targeted drug delivery. Consequently, scientists resorted to plasmonic based approaches, which rendered the entire approach inapplicable due to biodegradability concerns. In another work, an experimental realization for a method of magneto‐optical transmission maximization is reported. However, possible limitations on the higher excitation power needed for biomedical applications are still questionable. Furthermore, a comprehensive, quantitative understanding of all material and design related parameters influencing this enhancement is still needed for complete control over possible applications. Therefore, successfully derives a model for the magneto‐optical transmission under a time‐varying 0–4 kHz magnetic field, exhaustively accounting for material and design related phenomena; birefringence of hematite, dissipation, randomness, and anisotropy on the dielectric function, scattering cross‐section, and polarizability, for the first time. The model achieves an accuracy of 99.99% over the band 300–1100 nm and exhausts the model limitations to the decay time constant of Cotton–Mouton co‐effects. The dynamics of the problem are also derived, accounting for the influence of the magnetic field on the viscosity of the ferrofluid, which leads to an in‐depth, required understanding of the magneto‐optic interactions with ferrofluids for efficient applicability. [ABSTRACT FROM AUTHOR]

Coprinus comatus is an edible mushroom and its fermented product possesses antioxidant activity. In this study, to further enhance the antioxidant activity and improve the reusability of the strain, calcium alginate hydrogel was used as the carrier for embedding and immobilizing Coprinus comatus. The effects of CaCl2 concentration, sodium alginate concentration, microsphere diameter, and the amount of magnetic particle on the antioxidant activity of fermented products were investigated. The results showed that the magnetic immobilized microsphere prepared by 2.50% CaCl2, 2.00% sodium alginate and 0.50% Fe3O4 had the best fermentation antioxidant activity (EC50 was 0.43 ± 0.01 mg/mL) when the diameter was 5 mm, which increased by 24.56% compared to the initial activity. Besides, the microsphere showed strong reusability, the antioxidant activity was still better than the free strain after being used five times. This study not only enhanced the antioxidant activity of Coprinus comatus fermented product through immobilization, but also provided an effective method for microbial fermentation. [ABSTRACT FROM AUTHOR]

Purpose: This study investigates the behavior of viscous hybrid ferromagnetic fluids flowing through plain elastic sheets with the magnetic polarization effect. It examines flow in a porous medium using Stefan blowing and utilizes a versatile hybrid ferrofluid containing MnZnFe2O4 and Fe3O4 nanoparticles in the C2H2F4 base fluid, offering potential real-world applications. The study focuses on steady, laminar and viscous incompressible flow, analyzing heat and mass transfer aspects, including thermal radiation, Brownian motion, thermophoresis and viscous dissipation with convective boundary condition. Design/methodology/approach: The governing expression of the flow model is addressed with pertinent non-dimensional transformations, and the finite element method solves the obtained system of ordinary differential equations. Findings: The variations in fluid velocity, temperature and concentration profiles against all the physical parameters are analyzed through their graphical view. The association of these parameters with local surface friction coefficient, Nusselt number and Sherwood number is examined with the numerical data in a table. Originality/value: This work extends previous research on ferrofluid flow, investigating unexplored parameters and offering valuable insights with potential engineering, industrial and medical implications. It introduces a novel approach that uses mathematical simplification techniques and the finite element method for the solution. [ABSTRACT FROM AUTHOR]

We report a novel magnetic ionic liquid (MIL) based on pyridine successfully prepared by a two-step reaction pathway. The prepared MIL was recognized by means of Fourier transform infrared spectroscopy (FT-IR), UV–visible and Raman spectroscopies, thermal analysis (TGA and DTG), magnetic susceptibility measurement, mass spectra (MS), proton NMR ( 1 H NMR ), carbon NMR ( 13 C NMR ), Hammett acidity, and CHN elemental analysis. The MIL was shown to be efficient in the synthesis of xanthenediones under solvent-free conditions. In addition, the antibacterial and antifungal activity of the MIL was investigated. [ABSTRACT FROM AUTHOR]

This study presents an easy method for synthesizing ultrafine NixFe1–xFe2O4 nanoparticles with adjustable composition (x = 0–.8), followed by their stabilization into ferrofluids. Structural identification of the crystalline structure, lattice points, and grain boundaries from the broadened diffraction peaks reveal an average crystalline size of the nanoparticles as 10–16.5 nm. Transmission electron microscopy images reveal spherical magnetite nanoparticles with a particle size ranging from 6 to 13 nm, consistent with diffraction studies. In ferrofluids, the NixFe1–xFe2O4 nanoparticles are stabilized in kerosene with oleic acid, a surfactant. Absorbance data of the ferrofluids is seen in the 200–400 nm wavelength region of UV–vis spectra. The magnetic properties of the samples are probed using a Superconducting Quantum Interference Device. The synthesized samples exhibit superparamagnetic behavior at room temperature (300 K). The saturation magnetization of the samples decreases with an increase in Ni composition (x = 0–.8), ranging from 54 to 28 emu/g. This study explores the magnetic and magneto‐optical properties of NixFe1–xFe2O4 ferrofluids. Magneto‐viscosity of ferrofluids is also studied, and the final application of such ferrofluids in data storage, catalysis, and biomedical applications is discussed. [ABSTRACT FROM AUTHOR]

In this paper, we demonstrated a method of filling the air holes of a photonic crystal fiber (PCF), coated with gold film, with magnetic fluid (MF) to enhance the Surface Plasmon Resonance (SPR). The simulation results show that at the wavelength of 1260–1675 nm, the minimum loss coefficient of the y-polarization mode is 4.7 times that before filling with MF, and the x-polarization mode is 0.45 times greater. Then, based on this method, we designed a polarizing filter with a core diameter of 9 µm. The numerical simulation results indicate that it not only maintains the same core diameter as the single-mode fiber, but also has a larger bandwidth and a higher extinction ratio (ER). Additionally, we can optimize its ER at a specific wavelength by adjusting the magnetic field. [ABSTRACT FROM AUTHOR]

In this paper, the existence of finite-time splash singularity is proved for the free-boundary problem of the viscous and non-resistive incompressible magnetohydrodynamic (MHD) equations in R 3 , based on a construction of a sequence of initial data alongside delicate estimates of the solutions. The result and analysis in this paper generalize those by Coutand and Shkoller in [14, Ann. Inst. H. Poincaré C Anal. Non Linéaire, 2019] from the viscous surface waves to the viscous conducting fluids with magnetic effects for which non-trivial magnetic fields may present on the free boundary. The arguments in this paper also hold for any space dimension d ≥ 2. [ABSTRACT FROM AUTHOR]

[Display omitted] Generating multi-layer cargo using conventional methods is challenging. We hypothesize that incorporating a Y-junction compound droplet generator to encase a target core inside a second liquid can circumvent the kinetic energy dependence of the impact-driven liquid-liquid encapsulation technique, enabling minimally restrictive multi-layer encapsulation. Stable wrapping is obtained by impinging a compound droplet (generated using Y-junction) on an interfacial layer of another shell-forming liquid floating on a host liquid bath, leading to double-layered encapsulation. The underlying dynamics of the liquid-liquid interfaces are captured using high-speed imaging. To demonstrate the versatility of the technique, we used various liquids as interfacial layers, including magnetoresponsive oil-based ferrofluids. Moreover, we extended the technique to triple-layered encapsulation by overlaying a second interfacial layer atop the first floating interfacial layer. The encapsulating layer(s) effectively protects the water-soluble inner core (ethylene glycol) inside the water bath. A non-dimensional experimental regime is established for successful encapsulation in terms of the impact kinetic energy, interfacial layer thickness, and the viscosity ratio of the interfacial layer and the outer core liquid. Using selective fluorescent tagging, we confirm the presence of individual shell layers wrapped around the core, which presents a promising pathway to visualize the internal morphology of final encapsulated droplets. [ABSTRACT FROM AUTHOR]

We study minimizers of the Landau-de Gennes energy in R 3 \ B 1 (0) with external magnetic field in the large particle limit. We impose strong tangential anchoring and uniaxiality of the Q - tensor on the boundary. We derive a lower bound for the energy in terms of the boundary condition and show in the extreme cases of strong and weak magnetic field strength that the longitudinal director field is energy minimizing, indicating the presence of two half-point defects, so-called boojums, at two opposite points of the sphere. Using a recovery sequence, we show that the energy bound is optimal in these extreme cases. [ABSTRACT FROM AUTHOR]

In this study, we present a novel method for measuring the magnetic susceptibility of liquids using a Mach–Zehnder interferometer. The proposed technique employs a ring magnet to deform the liquid, while a laser beam passes through the liquid to measure the resulting interference pattern. The deformation of the liquid, caused by the known magnetic field of the ring magnet, is used to calculate the magnetic susceptibility. We provide a comprehensive theoretical framework, including the relevant equations and models, for analyzing the data obtained using this method. We compare the Mach–Zehnder interferometer method with other established techniques, highlighting its advantages and disadvantages. Our findings indicate that the Mach–Zehnder interferometer technique offers high accuracy, sensitivity, and potential applications in characterizing the magnetic properties of various liquid systems. [ABSTRACT FROM AUTHOR]

Prior magneto‐optical transmission models through ferrofluids are limited by oversimplifications which hinder accuracy and generalizability. To overcome this challenge, this study models the magnetic field effect on the magneto‐optical transmission through hematite ferrofluid using the method of invariant embedding. Optical coherence tomography (OCT) is used to extract the changes in the refractive index, enabling a discovery of a magnetodielectric effect for the hematite ferrofluid. To establish a basis for control and understanding, the influence of the magnetic field on the spatial transmission profile at different wavelengths, optical propagation lengths, and the effect of variation of each size parameter on the optical transmission have been investigated. Further parametric studies allowed finding out an analogy to nonuniform, cascade, volume holographic diffraction gratings, which is crucial for a wide range of optical and bioimaging applications. Compared to the experimental results, the presented model achieves 99% accuracy over the wavelength range (300–1100) nm under uniform static magnetic field (0–6.5) mT. Besides, the conspicuous lead of evidentiary understanding of magneto‐optical interactions with magnetic fluids, the structural milestones of the model can be further utilized to model similar challenging constructs in complex media. The innumerable applications of study extend to involve communication engineering, biomedical, optical, and security applications. [ABSTRACT FROM AUTHOR]

Highlights: Unique inter-skeleton conductive films are constructed in polymer foam. The resistance change of the foam can reach four orders of magnitude under compression. This foam exhibits strain-adaptive electromagnetic interference shielding performance, anti-interference pressure sensor with high sensitivity over a wide pressure range and compression-regulated Joule heating function. Conductive polymer foam (CPF) with excellent compressibility and variable resistance has promising applications in electromagnetic interference (EMI) shielding and other integrated functions for wearable electronics. However, its insufficient change amplitude of resistance with compressive strain generally leads to a degradation of shielding performance during deformation. Here, an innovative loading strategy of conductive materials on polymer foam is proposed to significantly increase the contact probability and contact area of conductive components under compression. Unique inter-skeleton conductive films are constructed by loading alginate-decorated magnetic liquid metal on the polymethacrylate films hanged between the foam skeleton (denoted as AMLM-PM foam). Traditional point contact between conductive skeletons under compression is upgraded to planar contact between conductive films. Therefore, the resistance change of AMLM-PM reaches four orders of magnitude under compression. Moreover, the inter-skeleton conductive films can improve the mechanical strength of foam, prevent the leakage of liquid metal and increase the scattering area of EM wave. AMLM-PM foam has strain-adaptive EMI shielding performance and shows compression-enhanced shielding effectiveness, solving the problem of traditional CPFs upon compression. The upgrade of resistance response also enables foam to achieve sensitive pressure sensing over a wide pressure range and compression-regulated Joule heating function. [ABSTRACT FROM AUTHOR]

Liquid manipulation using tubular actuators finds diverse applications ranging from microfluidics, printing, liquid transfer to micro‐reactors. Achieving flexible and simple regulation of manipulated liquid droplets during transport is crucial for the tubular liquid actuators to perform complex and multiple functions, yet it remains challenging. Here, a facile tubular actuator for directional transport of various liquid droplets under the control of an externally applied magnetic field is presented. The surfaces of the actuator can be engineered with submillimeter‐sized through‐hole pores, which enables the liquid droplet to be easily modulated in the transport process. Furthermore, the liquid actuator with featured through‐hole pores is expanded to function as a switch in an integrated external electric circuit by magnetically controlling the motion of a conductive liquid droplet. This work develops a strategy for regulating liquid droplets in the tubular actuation systems, which may inspire ideas for designing functional liquid actuators with potential applications in microfluidics, microchemical reaction, liquid switch, and liquid robotics. [ABSTRACT FROM AUTHOR]

Two classes of magnetohydrodynamic (MHD) motions of the incompressible Oldroyd-B fluids through an infinite cylinder are analytically investigated. General expressions are firstly established for shear stress and velocity fields corresponding to the motion induced by longitudinal shear stress on the boundary. For validation, the expression of the shear stress is determined by two different methods. Using an important remark regarding the governing equations for shear stress and fluid velocity corresponding to the two different motions, this expression is then used to provide the dimensionless velocity field of the MHD motion of the same fluids generated by a cylinder that rotates around its symmetry axis. Obtained results can generate exact solutions for any motion of this kind of Oldroyd-B fluids. Consequently, both types of motions are completely solved. For illustration, some case studies are considered, and adequate velocity fields are provided. The steady-state components of these velocities are presented in different forms whose equivalence is graphically proved. The influence of the magnetic field on the fluid behavior is graphically investigated. It was found that the fluid flows slower, and a steady state is earlier reached in the presence of a magnetic field. The fluid behavior when shear stress is given on the boundary is also investigated. [ABSTRACT FROM AUTHOR]

The initial delivery of small‐scale magnetic devices such as microrobots is a key, but often overlooked, aspect for their use in clinical applications. The deployment of these devices within the dynamic environment of the human body presents significant challenges due to their dispersion caused by circulatory flows. Here, a method is introduced to effectively deliver a swarm of magnetic nanoparticles in fluidic flows. This approach integrates a magnetically navigated robotic microcatheter equipped with a reservoir for storing the magnetic nanoparticles. The microfluidic flow within the reservoir facilitates the injection of magnetic nanoparticles into the fluid stream, and a magnetic field gradient guides the swarm through the oscillatory flow to a target site. The microcatheter and reservoir are engineered to enable magnetic steering and injection of the magnetic nanoparticles. To demonstrate this approach, experiments are conducted utilizing a spinal cord phantom simulating intrathecal catheter delivery for applications in the central nervous system. These results demonstrate that the proposed microcatheter successfully concentrates nanoparticles near the desired location through the precise manipulation of magnetic field gradients, offering a promising solution for the controlled deployment of untethered magnetic micro‐/nanodevices within the complex physiological circulatory systems of the human body. [ABSTRACT FROM AUTHOR]

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In this work, a magnetic fluid (Fe3O4/water) moving through a square tube in a steady-state and fluctuating electromagnetic field was investigated experimentally. The relevant parameter effects are considered, including rotating direction, flux, frequency, and frequency on the heat removal ability and flow resistance. The electromagnetic field induces the particles to move to the square tube wall, greatly influencing the boundary layer disturbance. A greater electromagnetic flux and rotating direction enhance nanoparticle turbulence intensity and local thermal conductivity. Compared to when it is fixed, the Nu of an electromagnetic field oscillating at 1.25 hz, 2.3 µT, is 9.16% more. Additionally, compared to the other modes, the Nu is greater by 3.41% when the mixed mode of the electromagnetic field rotates at 1.25 hz and 0.5 µT. The heat-removal capacity may be significantly increased by increasing the electromagnetic flux and frequency, which raises the Nu. The f is also further increased by the disruption of electromagnetic flow. [ABSTRACT FROM AUTHOR]

Ferrohydrodynamic pumps, with their compact design, offer a practical and efficient alternative to traditional pneumatic or mechanical pumps for driving microfluidic channels and fluidic devices, eliminating mechanical vibrations. A novel self‐circulating ferrohydrodynamic system has been developed to remotely control fluid flow within a linear acoustic cavity using a laser‐induced photothermal temperature gradient. This system enables the modulation of fluid flow rates in compact channels through adjustments in a D.C. magnetic field or laser‐induced surface temperature changes. Notably, laser intensity can accelerate, decelerate, or reverse flow rates within the channel, influencing ultrasonic waves propagating through fluidic cavities designed to resonate between 500 kHz and 700 kHz. The dynamic nature of the magnetoactive fluid cavity enhances wave‐matter interactions, particularly in acoustic domains. Laser‐induced flow control allows for precise manipulation of ultrasonic wave characteristics such as frequency, amplitude, mode splitting, phase shifting, and unidirectional transmission. This capability also supports the optical regulation of acoustic energy flow rates by halting or reversing fluid motion within the cavity. These advancements hold significant potential for applications in cavity acoustodynamics and underwater signal processing, promising innovations in remote fluidic control and acoustic modulation technologies. [ABSTRACT FROM AUTHOR]