A modified Hartmann test for testing aspherical convex surfaces of F/# 1 is analyzed. We present the main differences of this test in comparison to the usual Hartmann test. Theoretical results show that the transverse aberrations yielded by a testing surface have to be measured with respect to its mean sphere. A method to determine the mean sphere is also presented. Experimental results show th...

We present a robust, dense, and accurate Shack-Hartmann spot dislocation map determination method based on a regularized optical flow algorithm that does not require obtaining the spot centroids. The method is capable to measure in presence of strong noise, background illumination and spot modulating signals, which are typical limiting factors of traditional centroid detection algorithms. Moreo...

Most Shack-Hartmann based aberrometers use infrared light, for the comfort of the patients. A large amount of the light that is scattered from the retinal layers is recorded by the detector as background, from which it is not trivial to estimate the centroid of the Shack-Hartmann spot. For a centroiding algorithm, background light can lead to a systematic bias of the centroid positions towards ...

In this paper, we present a numerical study of turbulent natural-convection in square cavity differentially heated and filled with nanofluid subjected to an inclined magnetic field. The standard k-? model was used as the turbulence model. transport equations were discretized by finite volume method using SIMPLE algorithm. influence Rayleigh number, Hartmann orientation angle applied field, type...

Thermal transport characteristics of Casson nanofluid through a porous microtube is analyzed under the effect streaming potential and constant pressure gradient with electrokinetic associated applied magnetic field. An analytical solution velocity temperature distribution Casson-nano fluid related to combining effects electromagnetohydrodynamics forces have been obtained. The significant influe...

The aim of this paper is to investigate the effect of the variable thermal conductivity and the inclined uniform magnetic field on the plane Poiseuille flow of viscous incompressible electrically conducting fluid between two porous plates Joule heating in the presence of a constant pressure gradient through non-uniform plate temperature. It is assumed that the fluid injection occurs at lower pl...

In this report, the distribution and deviation of electric field in the active medium of the TE CO2 laser has been investigated due to the injection of net electron charge beam as a plasma generator. Some parameters of system have been considered, such as density and mean-free-path of injected charge beam. The electric potential and electric field distribution have been simulated by solving the...