These complex systems often consist of mechanically graded structures that resist and respond to external normal and shear forces, and therefore protect underlying tissues from incurring any damage. As an example, the human epidermis consists of keratinizing epithelial cells—an elastic layer with low modulus—buried under a layer of dead cells, the stratum corneum , with higher modulus. The stra...

In this study, dielectric properties of graded and non-graded InGaN/GaN multi quantum wells (MQWs), grown on sapphire(Al2O3) wafer by Metal Organic Chemical Vapor Deposition (MOCVD) technique, are investigated. order to notice layer effect characteristics MQWs some GaN layers doping atoms. Dielectric function films determined Swanepoel envelope method. Real imaginer coefficient the calculated u...

This study presents a new procedure based on Artificial Neural Network (ANN) for identification of double cracks in Functionally Graded Beams (FGBs). A cantilever beam is modeled using Finite Element Method (FEM) for analyzing a double-cracked FGB and evaluation of its first four natural frequencies for different cracks depths and locations. The obtained FEM results are verified against availab...

background: titanium (ti) implants are commonly coated with hydroxyapatite (ha). however, ha has some disadvantages such as brittleness, low tensile strength and fracture toughness. it is desirable to combine the excellent mechanical properties of zro2 and the chemical inertness of al2o3 with respect to the purpose of this project which was coating ti implants with ha-zro2-al2o3 to modify the s...

Work function measurements on cross sectioned microcrystalline pin silicon solar cells deposited by Hot−Wire CVD are presented. The experiment is realized by combining a modified Kelvin probe experiment and a scanning force microscope. The measured surface potential revealed that the built−in electric drift field is weak in the middle of the compensated intrinsic layer. A graded donor distribut...

The study of electric field distributions in graded systems is important due to various applications. We establish an analytical method based on the Maxwell equations, to investigate electric field distributions in graded multilayered colloidal crystals. This analytical method agrees very well with an existing numerical method. It convincingly explains and confirms the fact that the peak of ele...