in recent years, the plasma antenna is a new technology for replacing the metal antennas that have been designed with better performance. in the steady state, the radiation pattern of a plasma antenna will be similar to the case of metallic antennas with the same form, size and performance at the same frequency and power. by sweeping the parameters in the plasma tube, we can change the operatin...

In this paper, we analyze a distributed amplifier based on input/output attenuation compensation. The analysis is carried out for a HEMT transistor; and a constant-k section filter is used to calculate the amplifier’s characteristics such as attenuation factor, phase constant and gain. The proposed design approach enables us to examine the tradeoff among the variables, which include the type an...

Discrete-event simulation based optimization is the process of finding the optimum design of a stochastic system when the performance measure(s) could only be estimated via simulation. Randomness in simulation outputs often challenges the correct selection of the optimum. We propose an algorithm that merges Ranking and Selection procedures with a large class of random search methods for continu...

The present paper describes the designing of a thermally and economically optimum mechanical draft counter-flow wet cooling tower. The design model allows the use of a variety of packing materials in the cooling tower toward optimizing heat transfer. Once the optimum packing type is chosen, a compact cooling tower with low fan power consumption is modelled within the known design variables....

the aim of this paper is to design a fractional order sliding mode controllers (fosmc)for a class of dc-dc converters such as boost and buck converters. firstly, the control lawis designed with respect to the properties of fractional calculus, the design yields an equiv-alent control term with an addition of discontinuous (attractive) control law. secondly, themathematical proof of the stabilit...

efficiency of enzymes which are used in industrial or environmental applications is highly dependent on their thermal stability. in this study, the stability of dfpase has been evaluated after introducing disulfide bonds to the structure. the results obtained from a series of protein design software were subjected to molecular dynamics simulation at different temperature to test the performance...

Now a day centrifugal pumps are vital components of industries. Certainly, one of the most important specifications of centrifugal pumps are the performance curves. In the present work, performance curves of a centrifugal pumps are obtained by Computational fluid dynamics (CFD) and as an outcome, CFD results compare by practical curves. At the first step impeller and volute are designed with tw...