Study of Couple Stresses on MHD Poiseuille Flow through Porous Medium in a parallel plate channel
In this paper a mathematical analysis of effect of couple stresses on magneto hydrodynamic (MHD) flow past a parallel plate channel of viscous, incompressible and electrically conducting fluid in the presence of porous medium has been studied. An exact solution of the dimensionless governing equations has been obtained by using method of perturbation technique. The effects on velocity, discharge between the plates and wall shear are studied for different parameters like Hartmann number, Reynolds number, pulsation, time, porosity parameter, pulsation frequency and reported graphically to show the interesting aspect of the solution.
Peristaltically induced motion of a MHD third grade fluid in a deformable tube
We consider incompressible, magnetohydrodynamic (MHD) third grade fluid confined in a circular cylindrical tube. The tube surfaces are electrically non-conducting. Travelling sinusoidal wave is imposed on the tube which induces peristaltic motion in the fluid. The stream function, axial velocity and pressure gradient are determined analytically for small Deborah number (Γ). The analysis consists of a perturbation expansion in terms of the Deborah number up to O(Γ). Solutions for pressure rise and frictional force per wavelength are given through the use of numerical integration. The general solution of highly non-linear equation for the hydrodynamic third grade fluid is developed. The results are finally compared with the third grade hydrodynamic and Newtonian fluid cases. It is found that the axial velocity increases by increasing Deborah number but decreases for large values of Hartmann number.
Color image based sorter for separating red and white wheat
A simple imaging system was developed to inspect and sort wheat samples and other grains at moderate feed-rates (30 kernels/s or 3.5 kg wheat/h). A single camera captured color images of three sides of each kernel by using mirrors, and the images were processed using a personal computer (PC). Real time image acquisition and processing was enabled on an ordinary PC under Windows XP operating system using the IEEE 1394 data transfer protocol, DirectX application software, and dual-core computer processor. Image acquisition and transfer to the PC required approximately 17 ms per kernel, and an additional 1.5 ms was required for image processing. After classification, the computer could output a signal from the parallel port to activate an air valve to divert (sort) kernels into a secondary container. Hard red and hard white wheat kernels were used in this study to test and demonstrate sorter capability. Simple image statistics and histograms were used as features. Discriminant analysis was performed with one, two, or three features to demonstrate classification improvements with increased numbers of features. The sorter was able to separate hard red kernels from hard white kernels with 95 to 99% accuracy, depending on the wheat varieties, feed-rate, and number of classification features. The system is an economical and useful instrument for sorting wheat and other grains with high accuracy.