A radio frequency (rf) plasma source is operated at 2 MHz under an expanding magnetic field. The consists of a 14-cm-diameter and 25-cm-long tube wound by seven-turn rf loop antenna powered via impedance matching circuit. efficient power transfer to the demonstrated, high-density above 1012 cm−3 successfully obtained for kW level power. radial density profile having center peak observed both in...

in this paper, a novel directional super wide band micro strip antenna based on a simple and new geometry has been proposed. the antenna exhibits the widest bandwidth ever reported to the authors’ knowledge from 50 ghz to 200 ghz. its radiation pattern is approximately steady in the frequency ranges of 50 ghz to 200 ghz. the antenna consists of a club-like radiating patch, a combination of thre...

For many communication systems, including wireless networks, mobile, satellite, radar, remote sensing, and more applications, antenna arrays are very necessary. Utilizing effective beamforming techniques, have recently played a major part in driving data rates system capacity to extremely high levels. The capabilities performance both greatly influenced by the array configuration. Numerous stru...

Using Donnell-type shell theory a simple and exact procedure is presented for linear buckling analysis of functionally graded conical shells under axial compressive loads and external pressure. The solution is in the form of a power series in terms of a particularly convenient coordinate system. By analyzing the buckling of a series of conical shells, under various boundary conditions and diffe...

Abstract— The main aim of this study was to control the nonlinear process using multi-model PI controller. A multi model is developed for conical tank and it is validated against the real time setup conical tank process. A Multi model based PI controller is also developed, and implemented with realtime setup, and their performances are compared with that of the conventional controller of real t...

one of the effective methods to improve the thermal efficiency of solar collectors is using nanofluids as the coolant. the present study experimentally investigated the effect of sio2/water nanofluid with 1% mass fraction on the performance of a symmetric collector, i.e. conical solar collector. the conical solar collector with 1 m2 area and normal to the earth was tested in ahvaz, a city in th...

In Shark Bay, Western Australia, bottlenose dolphins Tursiops sp. carry conical sponges Echinodictyum mesenterinum on their rostra in the only documented cetacean foraging behaviour using a tool (‘sponging’). In this study, we examined the influence of various ecological factors on live sponge distribution and the occurrence of sponging in parts of the western gulf of Shark Bay. We assessed spo...

The existing formula for the transfer matrix of conical elements assumes constant wave number, which is only valid for sufficiently short conical elements. In acoustic waveguides, the phase velocity, attenuation constant, and hence complex wave number depend on frequency and cross-section radius. As for conical waveguides, the cross-section radius is position dependent, the transfer matrix must...

the output of a piezoelectric nanogenerator based on zno nanowire is largely affected by the shape of nanowire. in order to obtain mechanically stable nanogenerator with high performance, the investigation of mechanical and electrical characteristics related to the nanowires and materials used in nanogenerators are of great interest and significance. this paper presents the various behavior of ...