Alemu, Getachew2018-06-262023-11-092018-06-262023-11-092007-07http://10.90.10.223:4000/handle/123456789/3385In this thesis the Moire’ Defelectometery technique is applied to the investigation of diffusion dynamics in transparent liquid mixtures.It describe the theoretical analysis for obtaining the magnitude of diffusion coefficient using moire’ fringe patterns.The theoretical aspect of methods are presentes the relationship between the moire’fringe shift and diffusion coefficient.Based on moire’ effect, the displacement (moire’ fringe shift position) can be used to calculate deflection angle of laser beam,which is induced by the variation of refractive index.The physical and mathematical model of laser moire’ defelectometery is presented in detail. In diffusion of high concentration sugar solution the formation of dense layer above the initial boundary of two liquids was observed. This may be related to so-called baro-diffusion effect- influence of gravity on diffusant molecules , that forms ,the up ward motion of sugar molecules are balanced by gravity. Key Words : Moire’Deflectomrtery,Fringe Projection,Moire’Fringes ,Grating, Moire’Fringes, Index of Refraction, Moire’fringe shiftenMoire DeflectomrteryFringe ProjectionMoire’FringesGratingIndex of RefractionMoire’fringe shiftThesis