This paper proposes two sampling strategies based on the modified ratio estimator using the population mean of auxiliary variable and population correlation coefficient between the study variable and the auxiliary variable by Singh and Tailor (2003) for estimating the population mean (total) of the study variable in a finite population. A comparative study is made with usual sampling strategies...

in this paper the reflection coefficient of electromagnetic wave incidence on the walls of the buildings and obstacles that occurs in mobile communication path was modified by solving the riccati nonlinear equations. for this purpose, the building walls are assumed inhomogeneous layers where their permittivity changes as function of the wall thickness. using this reflection coefficient, a new p...

in this study, a sodalite nanozeolite was synthesized and characterized by x-ray diffraction (xrd) and scanning electronic microscopy (sem). following the morphology evolution of the sodalite nanozeolite in the sem images illustrates the formation of the spherical particle with a size between 60 and 80 nm. then, carbon paste electrode (cpe) was modified by sodalite nanozeolite and ni2+ ions. th...

a novel modified ni-zsm-5 nanozeolite was fabricated via an organic template-free hydrothermal route. the average particle size of ni-zsm-5 nanozeolite was calculated to be 85 nm by scanning electronic microscopy. then, carbon paste electrode (cpe) was modified by ni-zsm-5 nanozeolite and ni2+ ions were then incorporated to the nanozeolite matrix. electrochemical behavior of this electrode was ...

a novel chemically modified electrode containing prussian blue complex was achieved on the surface of glass carbon electrode by sol-gel technique. the electrochemical behavior of modified electrode was characterized by cyclic voltammetry in detail. the film electrode obtained was very stable and exhibited electrocatalytic response for oxidation of nitrite. results showed at bare gc electrode, a...

We present a novel method for simultaneously phase matching several nonlinear optical interactions within a single crystal. Quasiperiodic modulation of the nonlinear coefficient enables one to achieve high frequency mixing efficiencies for interactions with arbitrary wave vector differences. Doubling of two different frequencies as well as direct frequency tripling is experimentally demonstrate...