Hall current and joule heating effects on peristaltic flow of a sisko fluid with mild stenosis through a porous medium in a tapered artery with slip and convective boundary conditions

This work is arranged to investigate the Hall current and Joule heating effects on peristaltic flow of a Sisko fluid through a porous medium. The streaming is through tapered artery with mild stenosis. The influences of radiative heat transfer and chemical reactions are taken in consideration. Convective conditions are considered for heat and mass transfer. However, the slip conditions are adopted for the velocity distribution. The combined effects of viscous dissipation and radiation in energy expression are presented. Soret and Dufour features produce the coupled differential systems. The presumptions of the long wavelength and low Reynolds number are adopted to examine the governing equations of motion. The analytical solutions of these equations are given by two methods. The first one uses regular perturbation technique, which based on small wave number for small artery. The second one is based on utilizing the Homotopy perturbation technique. The approximate analytical solutions of the pressure rise and friction force are predestined along a numerical integration. The influences of various physical parameters of the problem are debated and depicted graphically through a set of figures. It is found that the axial velocity increases with the increase of Hall current parameter and with the decrease of Hartmann number. Also, it can be observed that the Brickmann number and Dufour number give rise to the fluid temperature. Meanwhile, reverse effect is observed towards concentration for both Schmidt number and chemical reaction number. Furthermore, the stream lines are graphically shown

Solitons on compact and noncompact spaces in large noncommutativity

We study solutions at the minima of scalar field potentials for Moyal spaces and torii in the large non-commutativity and interprete these solitons in terms of non-BPS D-branes of string theory. We derive a mass spectrum formula linking different D-branes together on quantum torii and suggest that it describes general systems of D-brane bound states extending the D2-D0 one. Then we propose a shape for the effective potential approaching these quasi-stable bound states. We give the gauge symmetries of these systems of branes and show that they depend on the quantum torii representations.Comment: 25 pages, Latex, 1 figure (use epsfig.sty), corrected formul

A novel method for high-dimensional anatomical mapping of extra-axial cerebrospinal fluid: Application to the infant brain

Cerebrospinal fluid (CSF) plays an essential role in early postnatal brain development. Extra-axial CSF (EA-CSF) volume, which is characterized by CSF in the subarachnoid space surrounding the brain, is a promising marker in the early detection of young children at risk for neurodevelopmental disorders. Previous studies have focused on global EA-CSF volume across the entire dorsal extent of the brain, and not regionally-specific EA-CSF measurements, because no tools were previously available for extracting local EA-CSF measures suitable for localized cortical surface analysis. In this paper, we propose a novel framework for the localized, cortical surface-based analysis of EA-CSF. The proposed processing framework combines probabilistic brain tissue segmentation, cortical surface reconstruction, and streamline-based local EA-CSF quantification. The quantitative analysis of local EA-CSF was applied to a dataset of typically developing infants with longitudinal MRI scans from 6 to 24 months of age. There was a high degree of consistency in the spatial patterns of local EA-CSF across age using the proposed methods. Statistical analysis of local EA-CSF revealed several novel findings: several regions of the cerebral cortex showed reductions in EA-CSF from 6 to 24 months of age, and specific regions showed higher local EA-CSF in males compared to females. These age-, sex-, and anatomically-specific patterns of local EA-CSF would not have been observed if only a global EA-CSF measure were utilized. The proposed methods are integrated into a freely available, open-source, cross-platform, user-friendly software tool, allowing neuroimaging labs to quantify local extra-axial CSF in their neuroimaging studies to investigate its role in typical and atypical brain development

The battle over Syria's reconstruction

Reconstruction is becoming the new battleground in the Syrian conflict—its continuation by other means. It is instrumentalized by the regime as a way to reconsolidate its control over the country and by rival regional and international powers to shape the internal balance of power and establish spheres of influence in the country. The paper examines the Asad regime’s practices, including co-optation of militia leaders via reconstruction concessions and use of reconstruction to clear strategic areas of opposition-dominated urban settlements. The paper then surveys how the geopolitical struggle in Syria has produced an asymmetry as regards reconstruction: those powers that lost the geo-political contest on the ground seek to use geo-economic superiority to reverse the geo-political outcome. Then the impact of proxy wars and spheres of influence in the country on the security context for reconstruction is examined. Finally, the reconstruction initiatives of the various external parties are assessed, including Russia, Iran and Turkey as well as the spoiler role by which the US seeks to obstruct reconstruction that would spell victory in Syria for its Russian and Iranian rivals.PostprintPeer reviewe

Minimizing Sensitivity to Clock Skew Variations Using Level Sensitive Latches

We propose a method for improving the tolerance of synchronous circuits to delay variations on the clock distribution. Instead of retiming and clock skew scheduling applied to edge-triggered flip-flops, as used by most other methods, we use level-sensitive latches placed based on a schedule of the operations. The resulting circuit can have a non-zero tolerance even at the optimal clock period, which is impossible with edge-triggered flip-flops

Effect of Partial Slip on Peristaltic Flow of a Sisko Fluid with Mild Stenosis through a Porous Medium

This paper investigates the effect of partial slip on peristaltic flow of a Sisko fluid through a porous medium. The flow is streaming through a tapered artery having a mild stenosis. The influences of heat and chemical reactions on blood flow are also taken into account. The governing equations of motion, energy and concentration are simplified by using the long wavelength and low Reynolds number approximations. The analytical solutions of these equations are obtained by considering a perturbation technique for small non- Newtonian Sisko fluid parameter. The pressure rise and friction force are numerically calculated. The numerical calculations with the help of graphs are adopted to obtain the effects of several parameters, such as the slip parameter, permeability parameter, the taper angle, Brickmann number, Soret number and the maximum height of stenosis, upon the distributions of velocity, temperature, concentration, pressure rise and friction force. It is found that the axial velocity increases with the increase of slip parameter. Meanwhile, it decreases with the increase of permeability parameter. The stream lines are also depicted. It is observed that the trapped bolus increases in size with the increase of both the slip parameter and the maximum height of stenosis. The other results are also illustrated