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Purpose: The present findings aim to investigate the thermal behavior of water-based nanofluid flow over a rotating surface, focusing on understanding the effects of different types of nanoparticles on thermal efficiency, considering thermal radiation and variable viscosity effects. By considering four distinct nanoparticles – silicon dioxide titanium dioxide, aluminum oxide and molybdenum disulfide – the study aims to provide insights into how nanoparticle addition influences heat production, thermal boundary layer thickness and overall thermal performance. Design/methodology/approach: The study employs computational methods, utilizing the BVP mid-rich algorithm for the solution procedure. The computational approach allows for a detailed investigation of the thermal behavior of nanofluid flows across a rotating surface under varying conditions. Findings: The study concludes that adding nanoparticles in the base liquid increases heat production in the system, resulting in enhanced thermal boundary layer thickness. The comparative analysis shows that different nanoparticle types exhibit varying effects on thermal efficiency, suggesting that careful selection of nanoparticles can optimize heat transport and thermal management processes. Moreover, there's a noteworthy uptrend in the radial velocity profile concerning the stretching parameter, whereas a converse trend is observed in the thermal profile. Originality/value: This study contributes original insights by comprehensively investigating the thermal behavior of water-based hybrid nanofluid flow over a rotating surface. [ABSTRACT FROM AUTHOR]

AbstractBoundary layer separation is a common challenge in fluid dynamics, where flow separates from a surface due to adverse pressure gradients. Transpiration, the injection or suction of fluid through a surface, is a technique used to mitigate this issue. This study investigates transpiration’s effects on boundary layer separation over a stretching wedge conveying ternary hybrid nanoparticles, which is crucial for optimizing various engineering systems. The study establishes a mathematical model incorporating transpiration, dual stretching, viscous dissipation, and nanoparticle volume fractions. The model is reduced to ordinary differential equations using similarity transformations and then solved numerically with MATLAB’s bvp4c package. Here, the convective heat transfer increases with suction and decreases with blowing due to changes in boundary layer thickness. This insight provides valuable information for engineers seeking to control temperature gradients in their systems. Moreover, the study highlights transpiration’s efficacy in mitigating boundary layer separation induced by adverse pressure gradients. Furthermore, flow enhancement with blowing depends on specific conditions, such as the value of the blowing parameter, highlighting its nuanced influence. [ABSTRACT FROM AUTHOR]

Keeping in view the importance of complex dynamical systems, we investigate the classical invariants for some non-Hermitian anharmonic potentials in one dimension. For this purpose, the rationalization method is employed under the elegance of the extended complex phase space approach. The invariants obtained are expected to play an important role in studying complex Hamiltonian systems at the classical as well as quantum levels. Key words: classical invariants, non-Hermitian Hamiltonian, rationalization method, anharmonic potentials, extended complex phase space approach. Gardant a l'esprit l'importance des systemes dynamiques complexes, nous examinons les invariants classiques pour certains potentiels anharmoniques non hermitiens en une dimension. A cette fin, nous utilisons la methode de rationalisation sous l'approche de l'elegant espace de phase complexe etendu. On attend que les invariants ainsi obtenus joueront un role dans l'etude des systemes Hamiltoniens complexes aussi bien classiques que quantiques. Mots-cles: invariants classiques, Hamiltonien non Hermitien, methode de rationalisation, potentiels anharmoniques, approche de l'espace de phase complexe etendu., 1. Introduction In the last few decades, several efforts have been made to explore the role of classical invariants in the qualitative study of Hamiltonian systems [1-7]. The existence of [...]

In this research, the dynamics of MHD Casson fluid flow has been discussed in the presence of non-Darcy Forchheimer porous medium. The investigation is focused on how thermal radiation, Soret–Dufour, and chemical reactions affect the incompressible Casson flow in a non-Darcy Forchheimer porous medium, taking account of pressure force. The mathematical model of the system is solved using the finite difference scheme followed by the shooting technique with bvp4c tool in MATLAB. The effects of physical parameters on velocity and transport (heat and mass) profile are illustrated through graphs. From the results, it is observed that Soret effect reduces the thermal boundary layer thickness which leads to the asymptotic increase in heat dissipation. The findings of the study on MHD Casson fluid model considering the non-Darcy Forchheimer porous medium are useful in engineering and science areas such as chemical machinery systems, geophysics, etc. [ABSTRACT FROM AUTHOR]

Dynamic changes in astrocyte Ca2+ are recognized as contributors to functional hyperemia, a critical response to increased neuronal activity mediated by a process known as neurovascular coupling (NVC). Although the critical role of glutamatergic signaling in this process has been extensively investigated, the impact of behavioral state, and the release of behavior-associated neurotransmitters, such as norepinephrine and serotonin, on astrocyte Ca2+ dynamics and functional hyperemia have received less attention. We used two-photon imaging of the barrel cortex in awake mice to examine the role of noradrenergic and serotonergic projections in NVC. We found that both neurotransmitters facilitated sensory stimulation-induced increases in astrocyte Ca2+. Interestingly, while ablation of serotonergic neurons reduced sensory stimulation-induced functional hyperemia, ablation of noradrenergic neurons caused both attenuation and potentiation of functional hyperemia. Our study demonstrates that norepinephrine and serotonin are involved in modulating sensory stimulation-induced astrocyte Ca2+ elevations and identifies their differential effects in regulating functional hyperemia. Noradrenergic and serotonergic signaling are involved in modulating sensory stimulation-induced astrocyte Ca2+ dynamics, and each signaling pathway alters functional hyperemia differently. [ABSTRACT FROM AUTHOR]

The prime concern of the present investigation includes a numerical approach targeting the study of heat and mass transfer for the flow of magnetic nanofluid based on hydrocarbon (C1-20B) past a rotating porous disk taking into cognizance the various parameters present. The modelled system of equations for the unsteady flow is rendered into the dimensionless non-linear system of differential equations, via suitable transformations. The modelled system of dimensionless equations is numerically solved by MATLAB bvp4c solver. The influence of involved emerging parameters, namely permeability, viscosity variation, rotation, radiation, ferrohydrodynamic interaction, thermophoresis, and Brownian motion parameters on flow regimes has been studied and shown graphically. Moreover, numerical data of the rate of heat and mass transfer and coefficients of skin friction are also mentioned in tabular form. It is found that the tangential velocity is reduced for increasing the value of viscosity variation parameters. The fluid temperature profile shows an increment when we increase the rotation of the disk. [ABSTRACT FROM AUTHOR]