Electro-osmotic flow of couple stress fluids in a microchannel propagated by peristalsis

A mathematical model is developed for electro-osmotic peristaltic pumping of a non-Newtonian liquid in a deformable micro-channel. Stokes’ couple stress fluid model is deployed to represent realistic working liquids. The Poisson-Boltzmann equation for electric potential distribution is implemented owing to the presence of an electrical double layer (EDL) in the micro-channel. Using long wavelength, lubrication theory and Debye-Huckel approximations, the linearized transformed dimensionless boundary value problem is solved analytically. The influence of electro-osmotic parameter (inversely proportional to Debye length), maximum electro-osmotic velocity (a function of external applied electrical field) and couple stress parameter on axial velocity, volumetric flow rate, pressure gradient, local wall shear stress and stream function distributions is evaluated in detail with the aid of graphs. The Newtonian fluid case is retrieved as a special case with vanishing couple stress effects. With increasing couple stress parameter there is a significant elevation in axial pressure gradient whereas the core axial velocity is reduced. An increase in electro-osmotic parameter induces both flow acceleration in the core region (around the channel centreline) and also enhances axial pressure gradient substantially. The study is relevant to simulation of novel smart bio-inspired space pumps, chromatography and medical microscale devices

Comparative study of Qurs-e-kafoor and Sharbat-e-bazoori motadil with Norfloxacin in the treatment of Urinary tract infection

Urinary tract infection occurs predominately in females, especially during child bearing age characterized by both microbial colonization of the urine and tissue invasion of any structure of the urinary tract, most commonly caused by Gram –ve bacteria i.e. E.coli, predisposed by various conditions like presence of foreign bodies e.g. calculi or catheter in the urinary tract, obstructive lesions in the urinary tract, pregnancy etc. This comparative study was carried out on 20 patients in each group A&B of either sex between 20-60 years. Qurs-e-kafoor and Sharbat-e-bazoori motadil were used in group A for 15 days and Norfloxacin 400mg in group B for 7 days. Promising results of Unani formulations Qurs-e-kafoor and Sharbat-e-bazoori motadil were found in relieving the symptoms after 15 days of treatment. Keywords: Urinary tract infection, Tadiya majra-e-baul, Qurs-e-kafoor, Sharbat-e-bazoori motadil, Norfloxacin

Low-temperature pretreatment of the root system of Brassica rapa L. plants : effects on the xylem sap exudation and on the nitrate absorption rate

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