Abstract: Stresses for the elastic-plastic transition and fully
plastic state have been derived for a thin rotating disc with inclusion
and results have been discussed numerically and depicted graphically.
It has been observed that the rotating disc with inclusion and made of
compressible material requires lesser angular speed to yield at the
internal surface whereas it requires higher percentage increase in
angular speed to become fully plastic as compare to disc made of
incompressible material.
Abstract: Present wireless communication demands compact and intelligent devices with multitasking capabilities at affordable cost. The focus in the presented paper is on a dual band antenna for wireless communication with the capability of operating at two frequency bands with same structure. Two resonance frequencies are observed with the second operation band at 4.2GHz approximately three times the first resonance frequency at 1.5GHz. Structure is simple loop of microstrip line with characteristic impedance 50 ohms. The proposed antenna is designed using defective ground structure (DGS) and shows the nearly one third reductions in size as compared to without DGS. This antenna was simulated on electromagnetic (EM) simulation software and fabricated using microwave integrated circuit technique on RT-Duroid dielectric substrate (εr= 2.22) of thickness (H=15 mils). The designed antenna was tested on automatic network analyzer and shows the good agreement with simulated results. The proposed structure is modeled into an equivalent electrical circuit and simulated on circuit simulator. Subsequently, theoretical analysis was carried out and simulated. The simulated, measured, equivalent circuit response, and theoretical results shows good resemblance. The bands of operation draw many potential applications in today’s wireless communication.
Abstract: Creep stresses and strain rates have been obtained
for a thin rotating disc having variable density with inclusion by
using Seth-s transition theory. The density of the disc is assumed to
vary radially, i.e. ( ) 0 ¤ü ¤ü r/b m - = ; ¤ü 0 and m being real positive
constants. It has been observed that a disc, whose density increases
radially, rotates at higher angular speed, thus decreasing the
possibility of a fracture at the bore, whereas for a disc whose
density decreases radially, the possibility of a fracture at the bore
increases.