Volume 10 - 2015

Permanent URI for this collectionhttp://repository.kln.ac.lk/handle/123456789/14680

Browse

Filters

20152

Settings

Search Results

Now showing 1 - 2 of 2
  • No Thumbnail Available
    Item
    Optical and Structural Properties of Spin Coated Cadmium Sulfide Thin Films
    (University of Kelaniya, 2015) Dissanayake, D.M.C.U.; Samarasekara, P.
    Thin films of cadmium sulfide have been synthesized using the spin coating technique. Films were fabricated on inexpensive amorphous glass substrates at spin speeds of 1500, 2200 and 2400 rpm for 30 seconds. Films were subsequently annealed at 200, 300 and 400 0C for one hour in air in order to crystallize the phase of CdS. Films were characterized using X-ray diffraction patterns (XRD) and UV-visible spectroscopy. According to XRD patterns, the phase of CdS was crystallized without any secondary phases. The particle size, dislocation density and strain were also estimated using XRD patterns. All the films indicate a strong orientation in (002) direction. The optical band gap was determined using UV absorption spectroscopy. Tauc model was employed to determine the optical band gap. According to our data, the optical band gap decreases with the particle size.
  • No Thumbnail Available
    Item
    An Exact Solution of Non-Newtonian Peristaltic Flow in a Tube : Rabinowitsch Fluid Model
    (University of Kelaniya, 2015) Singh, U.P.
    With the development of medical science, non-Newtonian fluids have taken on added significance with a variety of applications in real life. The flow of non-Newtonian fluids in tubes and pipes plays a vital role in daily life. The examples of such applications are medical instruments, human body, machines, etc. The study of such mechanisms with the Newtonian fluids has not been found satisfactory due to nonlinear behavior of stress strain relationship. In the present analysis, the study of peristaltic flow in a tube has been carried out taking into account the non-Newtonian fluid : Rabinowitsch fluid model. Considering the significant terms in Navier-Stokes equations, solutions have been derived for fluid flow in axial direction in terms of pressure gradient. Using the continuity of flow, and exact solution has been derived for fluid pressure at wall. To establish the applicability of the solution, results for pressure rise at wall, pressure gradient and streamlines have been presented graphically.