Islamic Azad University at Ardabil

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Ardabil, Iran
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Ojaroudi M.,Islamic Azad University at Ardabil | Ojaroudi N.,Islamic Azad University
IEEE Transactions on Antennas and Propagation | Year: 2014

This article proposes a novel, small, printed rectangular slot antenna for ultra-wideband (UWB) applications with dual band-notch function with band-notch performance. To increase the impedance bandwidth of the rectangular slot antenna and achieve UWB coverage, we use an inverted T-shaped conductor backed plane inside the rectangular slot on the other side of the substrate. Additionally, by using a coupled rotated C-shaped strip around the inverted T-shaped conductor backed plane, a frequency notched band performance has been obtained. The designed antenna has a small size of 20×20 mm2 while showing the radiation performance in the frequency band of 3.04 to over 10.87 GHz with a band rejection performance in the frequency band of 5.03 to 5.94 GHz. Simulated and measured results are presented to validate the usefulness of the proposed antenna structure for UWB applications. © 2013 IEEE.


Ojaroudi N.,Islamic Azad University at Ardabil
Microwave and Optical Technology Letters | Year: 2014

In this study, a new design of dual band-notched monopole antenna for ultrawideband (UWB) systems has been presented. The antenna consists of a pair of rotated T-ring strips protruded inside square-ring radiating patch, a feed line, and a ground plane with a pair of rotated E-shaped slot, which provides a wide usable fractional bandwidth of more than 140% with double band-stop performance. By applying the pair of rotated E-shaped slots in the ground plane, a new resonance at higher frequency range (14 GHz) is excited and much wider impedance bandwidth can be produced. In the proposed monopole antenna, to generate a single and dual frequency band-stop performance, we convert the square radiating patch to the square-ring structure with protruded T-ring strips. Simulated and measured results obtained for this antenna show that the proposed antenna offers very wide bandwidth from 2.65 to 15.1 GHz with two notched bands covering all the 5.2/5.8 GHz WLAN, 3.5/5.5 GHz WiMAX, and 4 GHz C bands. Simulated and experimental results obtained for this antenna show that it exhibits good radiation behavior within the UWB frequency range. © 2014 Wiley Periodicals, Inc.


Ojaroudi N.,Islamic Azad University at Ardabil
Microwave and Optical Technology Letters | Year: 2014

In this article, a novel small monopole antenna with dual band-notched characteristic for ultrawideband applications is proposed. The proposed antenna consists of circular-disc radiating patch with a rotated T-shaped slit, a feed line with a rotated Ω-shaped split-ring resonator, and a ground plane. The designed antenna has a small size. The simulated and measured results show that the antenna design exhibits an operating bandwidth (VSWR<2) from 2.86 to 12.92 GHz with 3.3-4.2 and 5-6 GHz rejected bands covering all the 5.2/5.8 GHz wireless local area network, 3.5/5.5 GHz worldwide interoperability microwave access, and 4 GHz C bands. Good antenna gain and radiation pattern characteristics are obtained in the frequency band of interest. © 2014 Wiley Periodicals, Inc.


Ghasemi A.,Islamic Azad University at Ardabil
International Journal of Electrical Power and Energy Systems | Year: 2013

In this paper, an improved multi objective Interactive Honey Bee Mating Optimization (IHBMO) is proposed to find the feasible optimal solution of the Environmental/Economic Power Dispatch (EED) problem with considering operational constraints of the generators. The EED problem is an important issue in power industry with considered the production of environmental pollution caused by fossil fuel consumption such as dangerous gases and carbon monoxide. The EED problem is formulated as a nonlinear constrained multi objective optimization problem which is solved by multi objective IHBMO techniques that has a strong ability to find the most optimal results. The three conflicting and non-commensurable: fuel cost, pollutant emissions and system loss, should be minimized simultaneously while satisfying certain system constraints. For achieve a good design with different solutions in a multi objective optimization problem, Pareto dominance concept is used to generate and sort the dominated and non-dominated solutions. Also, fuzzy set theory is employed to extract the best compromise solution. The propose method has been individually examined and applied to the standard IEEE 30-bus 6-generator, IEEE 180-bus fourteen generator and 40 generating unit (with valve point effect) test systems. The effectiveness of the proposed approach is demonstrated by comparing its performance with other evolutionary multi-objective optimization algorithms such as NSGA, NPGA, SPEA, MOPSO, MODE and MOHBMO. The computational results reveal that the multi objective IHBMO algorithm has excellent convergence characteristics and is superior to other multi objective optimization algorithms. Also, the results confirm its great potential in handling the multi-objective problems in power systems. © 2013 Elsevier Ltd. All rights reserved.


Abazari R.,Islamic Azad University at Ardabil
Romanian Reports in Physics | Year: 2014

In this work, the (G′ /G)-expansion method is proposed for constructing more general exact solutions of a special class of the nonlinear Benjamin-Bona-Mahoney-Burgers (BBM-B) equations including exponential terms appearing more in biological science which may contain high nonlinear terms. Our work is motivated by the fact that the (G′ /G)-expansion method provides not only more general forms of solutions but also periodic and solitary waves. If we set the parameters in the obtained wider set of solutions as special values, then some previously known solutions can be recovered. The method appears to be easier and faster by means of a symbolic computation system.


Ojaroudi N.,Islamic Azad University at Ardabil
Progress In Electromagnetics Research C | Year: 2014

In this paper, a different method for designing a novel and compact microstrip-fed slot antenna with band-notched characteristic for UWB application is proposed. In the proposed antenna, a pair of cross-shaped strips protruded inside an extra rectangular slot in the ground plane are used to crate an additional resonance in higher frequencies. By obtaining this resonance, the usable upper frequency of the antenna is extended from 9 to 14.8 GHz which provides a wide usable fractional bandwidth of more than 135%. Additionally, by using a square ring radiating stub with a pair of protruded T-shaped strips inside the ring, a desired frequency band-stop performance has been obtained. Good antenna gain and VSWR characteristics are obtained in the frequency band of interest. The proposed antenna can operate from 3.04 to 14.8 GHz for VSWR < 2 with a rejection band around 5.1 to 6 GHz to suppress any interference from wireless local area network (WLAN) systems. Simulated and experimental results obtained for this antenna show that it exhibits good radiation behavior within the UWB frequency range.


Hazrati Niyari A.,Islamic Azad University at Ardabil
Materials and Design | Year: 2013

Damping is a useful parameter for controlling vibration and movement in the design of the structure. The aim of this work is to develop a novel composite with high damping capacity. In this study, flexural damping responses of triple core (aluminium foam and PMI foam and H100 PVC foam) sandwich panels are investigated. A numerical modelling of the flexural damping response was performed using the ABAQUS software. All calculations about the theoretical approach were performed using the MATLAB software. A good match between the finite element modelling and the theoretical approach was obtained. © 2012 Elsevier Ltd.


Abazari R.,Islamic Azad University at Ardabil
Procedia Engineering | Year: 2011

In this work, the (G′/G) -expansion method with the aid of Maple is applied to construct more general exact solutions of the coupled Boussinesq equations, where the French scientist Joseph Valentin Boussinesq (1842-1929) described in the 1870's model equations for the propagation of long waves on the surface of water with a small amplitude. Each of the obtained solutions, namely hyperbolic function solutions, trigonometric function solutions and rational function solutions contain an explicit linear function of the variables in the considered equation. It is shown that the proposed method provides a powerful mathematical tool for solving nonlinear wave equations in mathematical physics and engineering problems. © 2011 Published by Elsevier Ltd.


Abazari R.,Islamic Azad University at Ardabil
Computers and Fluids | Year: 2010

In this work, the G'G-expansion method is proposed for constructing more general exact solutions of the three nonlinear evolution equations arising in fluids science with physical interest namely, Vakhnenko-Parkes equation, generalized regularized long wave (RLW) equation and symmetric regularized long wave (SRLW) equation. Our work is motivated by the fact that the (G′/G)-expansion method provides not only more general forms of solutions but also periodic and solitary waves. If we set the parameters in the obtained wider set of solutions as special values, then some previously known solutions can be recovered. The method appears to be easier and faster by means of a symbolic computation system. © 2010 Elsevier Ltd.


Abazari R.,Islamic Azad University at Ardabil
Mathematical and Computer Modelling | Year: 2010

In this work, the (G'/G)-expansion method is applied for constructing more general exact solutions of the three nonlinear evolution equations with physical interest namely, the Tzitzéica equation, the Dodd-Bullough-Mikhailov (DBM) equation and the Tzitzéica-Dodd-Bullough (TDB) equation. Our work is motivated by the fact that the (G'/G)-expansion method provides not only more general forms of solutions but also periodic and solitary waves. If we set the parameters in the obtained wider set of solutions as special values, then some previously known solutions can be recovered. The method appears to be easier and faster by means of a symbolic computation system. © 2010 Elsevier Ltd.

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