Mathematical analysis of two-phase blood flow through a stenosed curved artery with hematocrit and temperature dependent viscosity

A two-phase blood flow model is considered to analyze the fluid flow and heat transfer in a curved tube with time-variant stenosis. In both core and plasma regions, the variable viscosity model ( Hematocrit and non linear temperature-dependent, respectively) is considered. A toroidal coordinate system is considered to describe the governing equations. The perturbation technique in terms of perturbation parameter ε is used to obtain the temperature profile of blood flow. In order to find the velocity, wall shear stress and impedance profiles, a second-order finite difference method is employed with the accuracy of 10−6 in the each iteration. Under the conditions of fully-developed flow and mild stenosis, the significance of various physical parameters on the blood velocity, temperature, wall shear stress (WSS) and impedance are investigated with the help of graphs. A validation of our results has been presented and comparison has been made with the previously published work and present study, and it revels the good agreement with published work. The present mathematical study suggested that arterial curvature increase the fear of deposition of plaque (atherosclerosis), while, the use of thermal radiation in heat therapies lowers this risk. The positive add in the value of λ1 causes to increase in plasma viscosity; as a result, blood flow velocity in the stenosed artery decreases due to the assumption of temperature-dependent viscosity of the plasma region. Clinical researchers and biologists can adopt the present mathematical study to lower the risk of lipid deposition, predict cardiovascular disease risk and current state of disease by understanding the symptomatic spectrum, and then diagnose patients based on the risk.

Simulation Investigation of Bulk and Surface Properties of Liquid Benzonitrile: Ring Stacking  Assessment and Deconvolution

This manuscript is devoted to classical molecular dynamics (MD) simulation studies of the bulk and surface properties of liquid benzonitrile (BZN) in the temperature range of 293-323K. The content and the simulation-analysis are inspired by our recent ab initio calculation on benzonitrile, whereas present results are to expand and develop macroscopic documentation involving data verification. We investigate the molecular stacking that involves phenyl ring, which is notably absent in the counterpart acetonitrile solvent. MD simulations of the bulk liquid unravel the hydrogen bond (C≡N⋯H) formation and strength, in the order of ortho-H >> meta-H ~>para-H. The possibility for ortho-H’s to get involved in the formation of two bonds simultaneously confirms each having - and -bonding features. The singularity centered at about 313 K found in the trend of the simulated temperature-dependent viscosity and diffusion coefficient of liquid BZN goes alongside the reported experiment, and the phenomenon may root from a change in the internal frictional motion of the molecular cluster in stacking modes. Accordingly, we used vast efforts for analysis particularly based on the deconvolution of the corresponding complex correlation functions. Specific angle-dependent correlation functions led to the recognition of the stacking molecules and their strict orientational character by utilizing relative molecular twist angles. Recognition of the strict orientational character of the stacking molecules, as a clue to the singularity in the viscosity trend, will be discussed based on specific angle-dependent correlation functions.

Could the Réunion plume have thinned the Indian craton?

Thick and highly viscous roots are the key to cratonic survival. Nevertheless, cratonic roots can be destroyed under certain geological scenarios. Eruption of mantle plumes underneath cratons can reduce root viscosity and thus make them more prone to deformation by mantle convection. It has been proposed that the Indian craton could have been thinned due to eruption of the Réunion plume underneath it at ca. 65 Ma. In this study, we constructed spherical time-dependent forward mantle convection models to investigate whether the Réunion plume eruption could have reduced the Indian craton thickness. Along with testing the effect of different strengths of craton and its surrounding asthenosphere, we examined the effect of temperature-dependent viscosity on craton deformation. Our results show that the plume-induced thermomechanical erosion could have reduced the Indian craton thickness by as much as ~130 km in the presence of temperature-dependent viscosity. We also find that the plume material could have lubricated the lithosphere-asthenosphere boundary region beneath the Indian plate. This could be a potential reason for acceleration of the Indian plate since 65 Ma.