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 paper, the estimation of a scale parameter t under a new and bounded loss function, based on a reflection of the gamma density function, is discussed. The best scale-invariant estimator of tis obtained and the admissibility of all linear functions of the sufficient statistic, for estimating t in the absence of a nuisance parameter, is investigated

Techniques for numerical analysis and equivalent circuit modeling for loss performance of reflectarray antennas are presented in this paper. Numerical equations are employed to find out the values of reflection loss at resonant frequency and a novel set of predictions is applied to acquire the reflection loss curve for different materials. Equivalent circuit modeling using lumped components has...

Radar absorbing materials, i.e. magnetite (Fe3O4) coated carbon fibers (MCCFs) were fabricated by electro-deposition technique. Black-colored single spinel phase Fe3O4 nanoparticles was easily synthesized by hydrothermal method using reduction of a Fe (III) - Triethanolamine complex in an aqueous alkaline solution at 60-80 ◦C. Uniform and compact Fe3O4 films were fabricated on nitric acid treat...

The Radar Absorption Material (RAM) method is a coating for reducing the energy of electromagnetic waves received by converting emitted radar into heat energy. Hemp has been studied to have strongest and most stable tensile characteristics 5.5 g/den higher resistance compared other natural fibers. Combining hemp with alumina powder (Al2O3) epoxy resin could provide stealth technology system tha...

Using a conventional reflection high-energy electron diffraction gun together with an electron energy loss spectrometer, we have combined in situ measurements of inelastic scattering intensities from Si L2 s and Ge L2,3 core losses with reflection electron diffraction data in order to analyze the initial stages of Ge heteroepitaxy on Si(OO1). Diffraction data indicate an initial layer-by-layer ...

The setting and hardening process of concrete is considered to be the most critical time period during the life of a concrete structure. Previous research has been conducted on an ultrasonic wave reflection method that utilizes a steel plate embedded in the concrete to measure the reflection loss of shear waves at the steel-concrete interface. The reflection loss has been shown to have a linear...